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Hirai S, Yamada T, Katayama Y, Ishida M, Kawachi H, Matsui Y, Nakamura R, Morimoto K, Horinaka M, Sakai T, Sekido Y, Tokuda S, Takayama K. Effects of Combined Therapeutic Targeting of AXL and ATR on Pleural Mesothelioma Cells. Mol Cancer Ther 2024; 23:212-222. [PMID: 37802502 PMCID: PMC10831449 DOI: 10.1158/1535-7163.mct-23-0138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 07/12/2023] [Accepted: 10/03/2023] [Indexed: 10/10/2023]
Abstract
Few treatment options exist for pleural mesothelioma (PM), which is a progressive malignant tumor. However, the efficacy of molecular-targeted monotherapy is limited, and further therapeutic strategies are warranted to treat PM. Recently, the cancer cell-cycle checkpoint inhibitors have attracted attention because they disrupt cell-cycle regulation. Here, we aimed to establish a novel combinational therapeutic strategy to inhibit the cell-cycle checkpoint kinase, ATR in PM cells. The siRNA screening assay showed that anexelekto (AXL) knockdown enhanced cell growth inhibition when exposed to ATR inhibitors, demonstrating the synergistic effects of the ATR and AXL combination in some PM cells. The AXL and ATR inhibitor combination increased cell apoptosis via the Bim protein and suppressed cell migration when compared with each monotherapy. The combined therapeutic targeting of AXL and ATR significantly delayed regrowth compared with monotherapy. Thus, optimal AXL and ATR inhibition may potentially improve the PM outcome.
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Affiliation(s)
- Soichi Hirai
- Department of Pulmonary Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Tadaaki Yamada
- Department of Pulmonary Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Yuki Katayama
- Department of Pulmonary Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Masaki Ishida
- Department of Pulmonary Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Hayato Kawachi
- Department of Pulmonary Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Yohei Matsui
- Department of Pulmonary Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Ryota Nakamura
- Department of Pulmonary Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Kenji Morimoto
- Department of Pulmonary Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Mano Horinaka
- Department of Drug Discovery Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Toshiyuki Sakai
- Department of Drug Discovery Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Yoshitaka Sekido
- Division of Cancer Biology, Aichi Cancer Center Research Institute, Nagoya, Japan
- Division of Molecular and Cellular Oncology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Shinsaku Tokuda
- Department of Pulmonary Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Koichi Takayama
- Department of Pulmonary Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
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2
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Sokhi S, Lewis CW, Bukhari AB, Hadfield J, Xiao EJ, Fung J, Yoon YJ, Hsu WH, Gamper AM, Chan GK. Myt1 overexpression mediates resistance to cell cycle and DNA damage checkpoint kinase inhibitors. Front Cell Dev Biol 2023; 11:1270542. [PMID: 38020882 PMCID: PMC10652759 DOI: 10.3389/fcell.2023.1270542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 10/11/2023] [Indexed: 12/01/2023] Open
Abstract
Cell cycle checkpoint kinases serve as important therapeutic targets for various cancers. When they are inhibited by small molecules, checkpoint abrogation can induce cell death or further sensitize cancer cells to other genotoxic therapies. Particularly aberrant Cdk1 activation at the G2/M checkpoint by kinase inhibitors causing unscheduled mitotic entry and mitotic arrest was found to lead to DNA damage and cell death selectively in cancer cells. Promising drugs inhibiting kinases like Wee1 (Adavosertib), Wee1+Myt1 (PD166285), ATR (AZD6738) and Chk1 (UCN-01) have been developed, but clinical data has shown variable efficacy for them with poorly understood mechanisms of resistance. Our lab recently identified Myt1 as a predictive biomarker of acquired resistance to the Wee1 kinase inhibitor, Adavosertib. Here, we investigate the role of Myt1 overexpression in promoting resistance to inhibitors (PD166285, UCN-01 and AZD6738) of other kinases regulating cell cycle progression. We demonstrate that Myt1 confers resistance by compensating Cdk1 inhibition in the presence of these different kinase inhibitors. Myt1 overexpression leads to reduced premature mitotic entry and decreased length of mitosis eventually leading to increased survival rates in Adavosertib treated cells. Elevated Myt1 levels also conferred resistance to inhibitors of ATR or Chk1 inhibitor. Our data supports that Myt1 overexpression is a common mechanism by which cancer cells can acquire resistance to a variety of drugs entering the clinic that aim to induce mitotic catastrophe by abrogating the G2/M checkpoint.
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Affiliation(s)
- Sargun Sokhi
- Department of Oncology, University of Alberta, Edmonton, AB, Canada
- Experimental Oncology, Cross Cancer Institute, Edmonton, AB, Canada
- Cancer Research Institute of Northern Alberta, University of Alberta, Edmonton, AB, Canada
| | - Cody W. Lewis
- Department of Oncology, University of Alberta, Edmonton, AB, Canada
- Experimental Oncology, Cross Cancer Institute, Edmonton, AB, Canada
- Cancer Research Institute of Northern Alberta, University of Alberta, Edmonton, AB, Canada
| | - Amirali B. Bukhari
- Department of Oncology, University of Alberta, Edmonton, AB, Canada
- Experimental Oncology, Cross Cancer Institute, Edmonton, AB, Canada
- Cancer Research Institute of Northern Alberta, University of Alberta, Edmonton, AB, Canada
| | - Joanne Hadfield
- Department of Oncology, University of Alberta, Edmonton, AB, Canada
- Experimental Oncology, Cross Cancer Institute, Edmonton, AB, Canada
- Cancer Research Institute of Northern Alberta, University of Alberta, Edmonton, AB, Canada
| | - Edric J. Xiao
- Department of Oncology, University of Alberta, Edmonton, AB, Canada
- Experimental Oncology, Cross Cancer Institute, Edmonton, AB, Canada
- Cancer Research Institute of Northern Alberta, University of Alberta, Edmonton, AB, Canada
| | - Jeremy Fung
- Department of Oncology, University of Alberta, Edmonton, AB, Canada
- Experimental Oncology, Cross Cancer Institute, Edmonton, AB, Canada
| | - Yea Jin Yoon
- Department of Oncology, University of Alberta, Edmonton, AB, Canada
- Experimental Oncology, Cross Cancer Institute, Edmonton, AB, Canada
| | - Wen-Hsin Hsu
- Department of Oncology, University of Alberta, Edmonton, AB, Canada
- Experimental Oncology, Cross Cancer Institute, Edmonton, AB, Canada
- Cancer Research Institute of Northern Alberta, University of Alberta, Edmonton, AB, Canada
| | - Armin M. Gamper
- Department of Oncology, University of Alberta, Edmonton, AB, Canada
- Experimental Oncology, Cross Cancer Institute, Edmonton, AB, Canada
- Cancer Research Institute of Northern Alberta, University of Alberta, Edmonton, AB, Canada
| | - Gordon K. Chan
- Department of Oncology, University of Alberta, Edmonton, AB, Canada
- Experimental Oncology, Cross Cancer Institute, Edmonton, AB, Canada
- Cancer Research Institute of Northern Alberta, University of Alberta, Edmonton, AB, Canada
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3
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Cui J, Dean D, Hornicek FJ, Pollock RE, Hoffman RM, Duan Z. ATR inhibition sensitizes liposarcoma to doxorubicin by increasing DNA damage. Am J Cancer Res 2022; 12:1577-1592. [PMID: 35530299 PMCID: PMC9077062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 03/04/2022] [Indexed: 06/14/2023] Open
Abstract
Liposarcomas account for approximately 20% of all adult sarcomas and have limited therapeutic options outside of surgery. Inhibition of ataxia-telangiectasia and Rad3 related protein kinase (ATR) has emerged as a promising chemotherapeutic strategy in various cancers. However, its activation, expression, and function in liposarcoma remain unkown. In this study, we investigated the expression, function, and potential of ATR as a therapeutic target in liposarcoma. Activation and expression of ATR in liposarcoma was analyzed by immunohistochemistry, which was further explored for correlation with patient clinical characteristics. ATR-specific siRNA and the ATR inhibitor VE-822 were applied to determine the effect of ATR inhibition on liposarcoma cell proliferation and anti-apoptotic activity. Migration activity and clonogenicity were examined using wound healing and clonogenic assays. ATR (p-ATR) was overexpressed in 88.1% of the liposarcoma specimens and correlated with shorter overall survival in patients. Knockdown of ATR via specific siRNA or inhibition with VE-822 suppressed liposarcoma cell growth, proliferation, migration, colony-forming ability, and spheroid growth. Importantly, ATR inhibition significantly and synergistically enhanced liposarcoma cell line chemosensitivity to doxorubicin. Our findings support ATR as critical to liposarcoma proliferation and doxorubicin resistance. Therefore, the addition of ATR inhibition to a standard doxorubicin regimen is a potential treatment strategy for liposarcoma.
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Affiliation(s)
- Juncheng Cui
- Department of Orthopedic Surgery, The First Affiliated Hospital of University of South China69 Chuanshan Road, Hengyang 421001, Hunan, China
- Department of Orthopedic Surgery, Sarcoma Biology Laboratory, Sylvester Comprehensive Cancer Center, and The University of Miami Miller School of Medicine, Papanicolaou Cancer Research Building1550 NW. 10th Avenue, Miami, Florida 33136, USA
| | - Dylan Dean
- Department of Orthopedic Surgery, Sarcoma Biology Laboratory, Sylvester Comprehensive Cancer Center, and The University of Miami Miller School of Medicine, Papanicolaou Cancer Research Building1550 NW. 10th Avenue, Miami, Florida 33136, USA
- Department of Orthopaedic Surgery, Keck School of Medicine at University of Southern California (USC), USC Norris Comprehensive Cancer Center1441 Eastlake Ave, NTT 3449, Los Angeles, Califormia 90033, USA
| | - Francis J Hornicek
- Department of Orthopedic Surgery, Sarcoma Biology Laboratory, Sylvester Comprehensive Cancer Center, and The University of Miami Miller School of Medicine, Papanicolaou Cancer Research Building1550 NW. 10th Avenue, Miami, Florida 33136, USA
| | - Raphael E Pollock
- The James Comprehensive Cancer Center, The Ohio State UniversityColumbus, OH, USA
- Department of Surgery, Division of Surgical Oncology, The Ohio State University Wexner Medical CenterColumbus, Ohio 43210, USA
| | - Robert M Hoffman
- AntiCancer Inc., San Diego, CA, USA Department of Surgery, University of CaliforniaSan Diego, Califormia 92111, USA
| | - Zhenfeng Duan
- Department of Orthopedic Surgery, Sarcoma Biology Laboratory, Sylvester Comprehensive Cancer Center, and The University of Miami Miller School of Medicine, Papanicolaou Cancer Research Building1550 NW. 10th Avenue, Miami, Florida 33136, USA
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Wang LW, Jiang S, Yuan YH, Duan J, Mao ND, Hui Z, Bai R, Xie T, Ye XY. Recent Advances in Synergistic Antitumor Effects Exploited from the Inhibition of Ataxia Telangiectasia and RAD3-Related Protein Kinase (ATR). Molecules 2022; 27:molecules27082491. [PMID: 35458687 PMCID: PMC9029554 DOI: 10.3390/molecules27082491] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 03/27/2022] [Accepted: 04/05/2022] [Indexed: 02/04/2023] Open
Abstract
As one of the key phosphatidylinositol 3-kinase-related kinases (PIKKs) family members, ataxia telangiectasia and RAD3-related protein kinase (ATR) is crucial in maintaining mammalian cell genomic integrity in DNA damage response (DDR) and repair pathways. Dysregulation of ATR has been found across different cancer types. In recent years, the inhibition of ATR has been proven to be effective in cancer therapy in preclinical and clinical studies. Importantly, tumor-specific alterations such as ATM loss and Cyclin E1 (CCNE1) amplification are more sensitive to ATR inhibition and are being exploited in synthetic lethality (SL) strategy. Besides SL, synergistic anticancer effects involving ATRi have been reported in an increasing number in recent years. This review focuses on the recent advances in different forms of synergistic antitumor effects, summarizes the pharmacological benefits and ongoing clinical trials behind the biological mechanism, and provides perspectives for future challenges and opportunities. The hope is to draw awareness to the community that targeting ATR should have great potential in developing effective anticancer medicines.
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Affiliation(s)
- Li-Wei Wang
- School of Pharmacy, Hangzhou Normal University, Hangzhou 311121, China; (L.-W.W.); (S.J.); (Y.-H.Y.); (J.D.); (N.-D.M.); (Z.H.)
- Key Laboratory of Elemene Class Anti-Cancer Chinese Medicines, Engineering Laboratory of Development and Application of Traditional Chinese Medicines, Collaborative Innovation Center of Traditional Chinese Medicines of Zhejiang Province, Hangzhou Normal University, Hangzhou 311121, China
| | - Songwei Jiang
- School of Pharmacy, Hangzhou Normal University, Hangzhou 311121, China; (L.-W.W.); (S.J.); (Y.-H.Y.); (J.D.); (N.-D.M.); (Z.H.)
- Key Laboratory of Elemene Class Anti-Cancer Chinese Medicines, Engineering Laboratory of Development and Application of Traditional Chinese Medicines, Collaborative Innovation Center of Traditional Chinese Medicines of Zhejiang Province, Hangzhou Normal University, Hangzhou 311121, China
| | - Ying-Hui Yuan
- School of Pharmacy, Hangzhou Normal University, Hangzhou 311121, China; (L.-W.W.); (S.J.); (Y.-H.Y.); (J.D.); (N.-D.M.); (Z.H.)
- Key Laboratory of Elemene Class Anti-Cancer Chinese Medicines, Engineering Laboratory of Development and Application of Traditional Chinese Medicines, Collaborative Innovation Center of Traditional Chinese Medicines of Zhejiang Province, Hangzhou Normal University, Hangzhou 311121, China
| | - Jilong Duan
- School of Pharmacy, Hangzhou Normal University, Hangzhou 311121, China; (L.-W.W.); (S.J.); (Y.-H.Y.); (J.D.); (N.-D.M.); (Z.H.)
- Key Laboratory of Elemene Class Anti-Cancer Chinese Medicines, Engineering Laboratory of Development and Application of Traditional Chinese Medicines, Collaborative Innovation Center of Traditional Chinese Medicines of Zhejiang Province, Hangzhou Normal University, Hangzhou 311121, China
| | - Nian-Dong Mao
- School of Pharmacy, Hangzhou Normal University, Hangzhou 311121, China; (L.-W.W.); (S.J.); (Y.-H.Y.); (J.D.); (N.-D.M.); (Z.H.)
- Key Laboratory of Elemene Class Anti-Cancer Chinese Medicines, Engineering Laboratory of Development and Application of Traditional Chinese Medicines, Collaborative Innovation Center of Traditional Chinese Medicines of Zhejiang Province, Hangzhou Normal University, Hangzhou 311121, China
| | - Zi Hui
- School of Pharmacy, Hangzhou Normal University, Hangzhou 311121, China; (L.-W.W.); (S.J.); (Y.-H.Y.); (J.D.); (N.-D.M.); (Z.H.)
- Key Laboratory of Elemene Class Anti-Cancer Chinese Medicines, Engineering Laboratory of Development and Application of Traditional Chinese Medicines, Collaborative Innovation Center of Traditional Chinese Medicines of Zhejiang Province, Hangzhou Normal University, Hangzhou 311121, China
| | - Renren Bai
- School of Pharmacy, Hangzhou Normal University, Hangzhou 311121, China; (L.-W.W.); (S.J.); (Y.-H.Y.); (J.D.); (N.-D.M.); (Z.H.)
- Key Laboratory of Elemene Class Anti-Cancer Chinese Medicines, Engineering Laboratory of Development and Application of Traditional Chinese Medicines, Collaborative Innovation Center of Traditional Chinese Medicines of Zhejiang Province, Hangzhou Normal University, Hangzhou 311121, China
- Correspondence: (R.B.); (T.X.); (X.-Y.Y.); Tel.: +86-571-28860236 (X.-Y.Y.)
| | - Tian Xie
- School of Pharmacy, Hangzhou Normal University, Hangzhou 311121, China; (L.-W.W.); (S.J.); (Y.-H.Y.); (J.D.); (N.-D.M.); (Z.H.)
- Key Laboratory of Elemene Class Anti-Cancer Chinese Medicines, Engineering Laboratory of Development and Application of Traditional Chinese Medicines, Collaborative Innovation Center of Traditional Chinese Medicines of Zhejiang Province, Hangzhou Normal University, Hangzhou 311121, China
- Correspondence: (R.B.); (T.X.); (X.-Y.Y.); Tel.: +86-571-28860236 (X.-Y.Y.)
| | - Xiang-Yang Ye
- School of Pharmacy, Hangzhou Normal University, Hangzhou 311121, China; (L.-W.W.); (S.J.); (Y.-H.Y.); (J.D.); (N.-D.M.); (Z.H.)
- Key Laboratory of Elemene Class Anti-Cancer Chinese Medicines, Engineering Laboratory of Development and Application of Traditional Chinese Medicines, Collaborative Innovation Center of Traditional Chinese Medicines of Zhejiang Province, Hangzhou Normal University, Hangzhou 311121, China
- Correspondence: (R.B.); (T.X.); (X.-Y.Y.); Tel.: +86-571-28860236 (X.-Y.Y.)
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5
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Chow B, Warkentin B, McEwen M, Huang F, Nanda K, Gamper AM, Menon G. Uncertainties Associated with Clonogenic Assays using a Cs-137 Irradiator and Ir-192 Afterloader: A Comprehensive Compilation for Radiation Researchers. Radiat Res 2022; 198:40-56. [PMID: 35391488 DOI: 10.1667/rade-21-00205.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 03/17/2022] [Indexed: 11/03/2022]
Abstract
Clonogenic assays are the gold standard for measuring cell clonogenic survival and enable quantification of a cell line's radiosensitivity through the calculation of the surviving fraction, the ratio of cell clusters (colonies) formed after radiation exposure compared to the number formed without exposure. Such studies regularly utilize Cs-137 irradiators. While uncertainties for specific procedural aspects have been described previously, a comprehensive review has not been completed. We therefore quantified uncertainties associated with clonogenic assays performed using a Cs-137 Shepherd irradiator, and a recently established brachytherapy afterloader in vitro radiation delivery apparatus (BAIRDA), through a series of experiments and a literature review. The clonogenic assay is subject to uncertainties that affect the determination of the surviving fraction (e.g., accuracy of the number of cells seeded, potential effects of hypothermia, and the threshold number of cells for a cluster to be identified as a colony). Furthermore, dose delivery uncertainties related to both the Cs-137 irradiator and BAIRDA were also quantified. The combined standard (k = 1) uncertainty was ± 6.0% in the surviving fraction for the Cs-137 irradiator (±6.3% for BAIRDA), up to ± 1.3% in the dose delivered by the Cs-137 irradiator, and up to ± 2.2% in the dose delivered by BAIRDA. The largest individual uncertainties were associated with the number of cells seeded on a plate (3.4%) and inter-observer variability in counting (4.1%), suggesting that effective reduction of uncertainties in the conduct of the clonogenic assay proper may provide the greatest relief on the uncertainty budget. Finally, measurable impact on experimental findings was assessed by applying this uncertainty to clonogenic assays of SW756 cells using either a Cs-137 irradiator or BAIRDA, introducing a maximum shift in the reported radiobiological parameters a/b and T1/2 of 0.3 Gy and 0.4 h, respectively, while the 95% confidence interval increased by 0.5 Gy and decreased by 0.4 h, respectively. Though the overall impact on radiobiological parameter estimation was small, the individual uncertainties could have a significant influence in other applications of in vitro experiments in radiation biology. Hence, better understanding of the uncertainties associated with both clonogenic assays and the radiation source used can improve the accuracy of experimental analysis and reproducibility of the results.
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Affiliation(s)
- Braden Chow
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
| | - Brad Warkentin
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
| | - Malcolm McEwen
- Ionizing Radiation Standards, National Research Council of Canada, Ottawa, Canada
| | - Fleur Huang
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
| | - Kareena Nanda
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
| | - Armin M Gamper
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
| | - Geetha Menon
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
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6
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Chow B, Warkentin B, Nanda K, Ghosh S, Huang F, Gamper AM, Menon G. BAIRDA: a novel in vitro setup to quantify radiobiological parameters for cervical cancer brachytherapy dose estimations. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac4fa3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 01/27/2022] [Indexed: 11/11/2022]
Abstract
Abstract
Objective. Brachytherapy (BT) dose prescriptions for locally advanced cervical cancer are made with account for the radiobiological parameters, α/β ratio and halftime of repair (T
1/2
). However, a wide range of parameter values has been reported which can challenge commonly held equivalencies between dose prescriptions. This is the first reported study that aims to develop an in vitro experimental technique using clinical high-dose-rate (HDR) and pulsed-dose-rate (PDR) Ir-192 brachytherapy afterloaders to quantify these parameters in vitro and to contextualize findings within contemporary practice. Approach. To efficiently quantify α/β and T
1/2
, in vitro experiments more reflective of clinical BT practice than traditional clonogenic survival assays were developed and applied to four squamous cell carcinoma cell lines (CaSki, C-33A, SiHa, and SW756). Radiation was delivered using single acute and fractionated dose treatments with a conventional irradiator and clinical HDR and PDR BT afterloaders. For the latter, a novel brachytherapy afterloader
in vitro
radiation delivery apparatus (BAIRDA) was developed. Main Results. The α/β and T
1/2
values determined using BAIRDA and the conventional irradiator showed close agreement, validating the novel apparatus and technique. For CaSki, C-33A, SiHa, and SW756, the BAIRDA-measured α/β ratios (5.2 [4.6–5.8], 5.6 [4.5–6.6], 6.3 [4.9–7.7], and 5.3 [4.7–6.0] Gy, respectively) were consistently smaller, while the T
1/2
(3.3 [2.7–3.9], 2.7 [2.0–3.3], 2.8 (2.4–3.1], and 4.8 [4.1–5.4] hours) larger, than the widely accepted values in clinical practice (α/β = 10 Gy; T
1/2
= 1.5 h). Significance. In vitro experiments using BAIRDA provided evidence for differences between the conventionally selected and experimentally determined α/β ratio and T
1/2
. Treatment regimens using HDR-BT and PDR-BT, designed to deliver equivalent radiobiological doses based on conventional values, were shown to differ by up to 27 Gy EQD2 – an effect that could impact treatment outcomes in cervical cancer. Furthermore, with BAIRDA, we have developed a novel method for radiobiological research in BT.
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Bukhari AB, Chan GK, Gamper AM. Targeting the DNA Damage Response for Cancer Therapy by Inhibiting the Kinase Wee1. Front Oncol 2022; 12:828684. [PMID: 35251998 PMCID: PMC8891215 DOI: 10.3389/fonc.2022.828684] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 01/21/2022] [Indexed: 12/15/2022] Open
Abstract
Cancer cells typically heavily rely on the G2/M checkpoint to survive endogenous and exogenous DNA damage, such as genotoxic stress due to genome instability or radiation and chemotherapy. The key regulator of the G2/M checkpoint, the cyclin-dependent kinase 1 (CDK1), is tightly controlled, including by its phosphorylation state. This posttranslational modification, which is determined by the opposing activities of the phosphatase cdc25 and the kinase Wee1, allows for a more rapid response to cellular stress than via the synthesis or degradation of modulatory interacting proteins, such as p21 or cyclin B. Reducing Wee1 activity results in ectopic activation of CDK1 activity and drives premature entry into mitosis with unrepaired or under-replicated DNA and causing mitotic catastrophe. Here, we review efforts to use small molecule inhibitors of Wee1 for therapeutic purposes, including strategies to combine Wee1 inhibition with genotoxic agents, such as radiation therapy or drugs inducing replication stress, or inhibitors of pathways that show synthetic lethality with Wee1. Furthermore, it become increasingly clear that Wee1 inhibition can also modulate therapeutic immune responses. We will discuss the mechanisms underlying combination treatments identifying both cell intrinsic and systemic anti-tumor activities.
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8
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Feng S, Ma S, Li K, Gao S, Ning S, Shang J, Guo R, Chen Y, Blumenfeld B, Simon I, Li Q, Guo R, Xu D. RIF1-ASF1-mediated high-order chromatin structure safeguards genome integrity. Nat Commun 2022; 13:957. [PMID: 35177609 PMCID: PMC8854732 DOI: 10.1038/s41467-022-28588-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 02/01/2022] [Indexed: 11/12/2022] Open
Abstract
The 53BP1-RIF1 pathway antagonizes resection of DNA broken ends and confers PARP inhibitor sensitivity on BRCA1-mutated tumors. However, it is unclear how this pathway suppresses initiation of resection. Here, we identify ASF1 as a partner of RIF1 via an interacting manner similar to its interactions with histone chaperones CAF-1 and HIRA. ASF1 is recruited to distal chromatin flanking DNA breaks by 53BP1-RIF1 and promotes non-homologous end joining (NHEJ) using its histone chaperone activity. Epistasis analysis shows that ASF1 acts in the same NHEJ pathway as RIF1, but via a parallel pathway with the shieldin complex, which suppresses resection after initiation. Moreover, defects in end resection and homologous recombination (HR) in BRCA1-deficient cells are largely suppressed by ASF1 deficiency. Mechanistically, ASF1 compacts adjacent chromatin by heterochromatinization to protect broken DNA ends from BRCA1-mediated resection. Taken together, our findings identify a RIF1-ASF1 histone chaperone complex that promotes changes in high-order chromatin structure to stimulate the NHEJ pathway for DSB repair. The 53BP1-RIF1 pathway is important for DNA repair. Here, the authors identified the histone chaperone ASF1, which functions as a suppressor of DNA end resection through changing high-order chromatin structure, as a partner of RIF1. This finding links DNA repair and dynamic changes of high-order chromatin structure.
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Affiliation(s)
- Sumin Feng
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, 100871, Beijing, China
| | - Sai Ma
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, 100871, Beijing, China
| | - Kejiao Li
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, 100871, Beijing, China
| | - Shengxian Gao
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, 100871, Beijing, China
| | - Shaokai Ning
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, 100871, Beijing, China
| | - Jinfeng Shang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, 100871, Beijing, China
| | - Ruiyuan Guo
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, 100871, Beijing, China
| | - Yingying Chen
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, 100871, Beijing, China
| | - Britny Blumenfeld
- Department of Microbiology and Molecular Genetics, Institute of Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University, Jerusalem, 91120, Israel
| | - Itamar Simon
- Department of Microbiology and Molecular Genetics, Institute of Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University, Jerusalem, 91120, Israel
| | - Qing Li
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, 100871, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, 100871, Beijing, China
| | - Rong Guo
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, 100871, Beijing, China
| | - Dongyi Xu
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, 100871, Beijing, China.
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Shift in G1-Checkpoint from ATM-Alone to a Cooperative ATM Plus ATR Regulation with Increasing Dose of Radiation. Cells 2021; 11:cells11010063. [PMID: 35011623 PMCID: PMC8750242 DOI: 10.3390/cells11010063] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 12/23/2021] [Accepted: 12/24/2021] [Indexed: 12/13/2022] Open
Abstract
The current view of the involvement of PI3-kinases in checkpoint responses after DNA damage is that ATM is the key regulator of G1-, S- or G2-phase checkpoints, that ATR is only partly involved in the regulation of S- and G2-phase checkpoints and that DNA-PKcs is not involved in checkpoint regulation. However, further analysis of the contributions of these kinases to checkpoint responses in cells exposed to ionizing radiation (IR) recently uncovered striking integrations and interplays among ATM, ATR and DNA-PKcs that adapt not only to the phase of the cell cycle in which cells are irradiated, but also to the load of DNA double-strand breaks (DSBs), presumably to optimize their processing. Specifically, we found that low IR doses in G2-phase cells activate a G2-checkpoint that is regulated by epistatically coupled ATM and ATR. Thus, inhibition of either kinase suppresses almost fully its activation. At high IR doses, the epistatic ATM/ATR coupling relaxes, yielding to a cooperative regulation. Thus, single-kinase inhibition suppresses partly, and only combined inhibition suppresses fully G2-checkpoint activation. Interestingly, DNA-PKcs integrates with ATM/ATR in G2-checkpoint control, but functions in its recovery in a dose-independent manner. Strikingly, irradiation during S-phase activates, independently of dose, an exclusively ATR-dependent G2 checkpoint. Here, ATM couples with DNA-PKcs to regulate checkpoint recovery. In the present work, we extend these studies and investigate organization and functions of these PI3-kinases in the activation of the G1 checkpoint in cells irradiated either in the G0 or G1 phase. We report that ATM is the sole regulator of the G1 checkpoint after exposure to low IR doses. At high IR doses, ATM remains dominant, but contributions from ATR also become detectable and are associated with limited ATM/ATR-dependent end resection at DSBs. Under these conditions, only combined ATM + ATR inhibition fully abrogates checkpoint and resection. Contributions of DNA-PKcs and CHK2 to the regulation of the G1 checkpoint are not obvious in these experiments and may be masked by the endpoint employed for checkpoint analysis and perturbations in normal progression through the cell cycle of cells exposed to DNA-PKcs inhibitors. The results broaden our understanding of organization throughout the cell cycle and adaptation with increasing IR dose of the ATM/ATR/DNA-PKcs module to regulate checkpoint responses. They emphasize notable similarities and distinct differences between G1-, G2- and S-phase checkpoint regulation that may guide DSB processing decisions.
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Xi SJ, Cai WQ, Wang QQ, Peng XC. Role of circular RNAs in gastrointestinal tumors and drug resistance. World J Clin Cases 2021; 9:10400-10417. [PMID: 35004973 PMCID: PMC8686142 DOI: 10.12998/wjcc.v9.i34.10400] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 03/26/2021] [Accepted: 08/05/2021] [Indexed: 02/06/2023] Open
Abstract
The incidence of gastrointestinal cancers has increased significantly over the past decade and gastrointestinal malignancies now rank among the leading causes of mortality globally. Although newer therapeutic strategies such as targeted therapies have greatly improved patient outcomes, their clinical success is limited by drug resistance, treatment failure and recurrence of metastatic disease. Therefore, there is an urgent need for further research identifying accurate and reliable biomarkers for precise treatment strategies. Circular RNAs (circRNAs) exhibit a covalently closed structure, high stability and biological conservation, and their expression is associated with the occurrence and development of gastrointestinal tumors. Moreover, circRNAs may significantly influence drug resistance of gastrointestinal cancers. In this article, we review the role of circRNAs in the occurrence and development of gastrointestinal cancer, their association with drug resistance, and potential application for early diagnosis, treatment and prognosis in gastrointestinal malignancies. Furthermore, we summarize characteristics of circRNA, including mechanism of formation and biological effects via mRNA sponging, chromatin replication, gene regulation, translational modification, signal transduction, and damage repair. Finally, we discuss whether circRNA-related noninvasive testing may be clinically provided in the future. This review provides new insights for the future development of diagnostics and therapeutics based on circRNAs in gastrointestinal tumors.
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Affiliation(s)
- Shi-Jun Xi
- Department of Pathophysiology, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou 434023, Hubei Province, China
| | - Wen-Qi Cai
- Department of Pathophysiology, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou 434023, Hubei Province, China
| | - Qin-Qi Wang
- Department of Pathophysiology, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou 434023, Hubei Province, China
| | - Xiao-Chun Peng
- Department of Pathophysiology, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou 434023, Hubei Province, China
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11
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Thielhelm TP, Goncalves S, Welford S, Mellon EA, Bracho O, Estivil M, Brown C, Morcos J, Ivan ME, Telischi F, Fernandez-Valle C, Dinh CT. Primary Vestibular Schwannoma Cells Activate p21 and RAD51-Associated DNA Repair Following Radiation-Induced DNA Damage. Otol Neurotol 2021; 42:e1600-e1608. [PMID: 34420024 PMCID: PMC8595670 DOI: 10.1097/mao.0000000000003322] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
HYPOTHESIS Vestibular Schwannoma (VS) can avoid cell death following radiation injury by entering cell cycle arrest and activating RAD51-related DNA repair. BACKGROUND Although the radiobiology of various cancers is well-studied, the radiobiological effects in VS are poorly understood. In this study, we describe how VS cells enter cell cycle arrest (through p21 expression), activate DNA repair (through RAD51 upregulation), and avoid cell death after radiation-induced double-stranded breaks (DSB) in DNA (as measured by γ-H2AX). METHODS Primary human VS cells were cultured on 96-well plates and 16-well culture slides at 10,000 cells/well and exposed to either 0 or 18 Gray of radiation. Viability assays were performed at 96 h in vitro. Immunofluorescence for γ-H2AX, RAD51, and p21 was performed at 6 h. RESULTS Radiation (18 Gy) induced the expression of γ-H2AX, p21, and RAD51 in six cultured VS, suggesting that irradiated VS acquire DSBs, enter cell cycle arrest, and initiate RAD51 DNA repair to evade cell death. However, viability studies demonstrate variable responses in individual VS cells with 3 of 6 VS showing radiation resistance to 18 Gy. On further analyses, radiation-resistant VS cells expressed significantly more p21 than radiation-responsive tumors. CONCLUSIONS In response to radiation-induced DNA damage, primary VS cells can enter cell cycle arrest and express RAD51 DNA repair mechanisms to avoid cell death. Radioresistant VS cells may mount a more robust p21 response to ensure sufficient time for DNA repair. Further investigation into DNA repair proteins and cell cycle checkpoints may provide important insight on the radiobiology of VS and mechanisms for resistance.
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Affiliation(s)
- Torin P. Thielhelm
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL
| | - Stefania Goncalves
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL
| | - Scott Welford
- Department of Radiation Oncology, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL
| | - Eric A. Mellon
- Department of Radiation Oncology, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL
| | - Olena Bracho
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL
| | - Michael Estivil
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL
| | - Clifford Brown
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL
| | - Jacques Morcos
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL
| | - Michael E. Ivan
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL
| | - Fred Telischi
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL
| | - Cristina Fernandez-Valle
- Burnett School of Biomedical Sciences, University of Central Florida, College of Medicine, Orlando, FL
| | - Christine T. Dinh
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL
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12
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Combination of the 6-thioguanine and disulfiram/Cu synergistically inhibits proliferation of triple-negative breast cancer cells by enhancing DNA damage and disrupting DNA damage checkpoint. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2021; 1869:119169. [PMID: 34763028 DOI: 10.1016/j.bbamcr.2021.119169] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 10/18/2021] [Accepted: 11/01/2021] [Indexed: 11/22/2022]
Abstract
Because of the lack of specific molecular targeted therapies, triple-negative breast cancer (TNBC) has high tumour recurrence and metastasis rates. It is urgent to develop novel chemotherapeutic strategies to improve patient survival. DNA damaging agents have been shown to sensitize cancer to genotoxic chemotherapies. We first found that 6-thioguanine (6-TG) can activate the NF-кB signalling pathway. Our results showed that NF-кB signalling was reduced when cells were treated with 6-TG/disulfiram (DSF)/Cu. DSF/Cu enhanced the 6-TG-mediated inhibition of proliferation. 6-TG/DSF/Cu inhibited cell cycle progression, causing cell cycle arrest in the S phase and G2/M phase. Moreover, the combined effect of 6-TG and DSF/Cu induced apoptosis, and either agent alone was able to induce apoptosis. The accumulation of γH2A indicated that DSF/Cu increased the DNA damage induced by 6-TG. Combined treatment with 6-TG and DSF/Cu synergistically reduced the levels of both phosphorylated and total ataxia-telangiectasia-mutated-and-Rad3-related kinase (ATR), suggesting that DSF/Cu promoted 6-TG-induced DNA damage by suppressing ATR protein kinases, therefore enhancing cell apoptosis. In conclusion, we demonstrate that the combination of 6-TG and DSF/Cu exerted a significant synergistic antitumour effect on human TNBC in vitro and in vivo by enhancing DNA damage and disrupting DNA damage checkpoints. We propose that this combination therapy could be a novel strategy for the treatment of TNBC.
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13
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Frock RL, Sadeghi C, Meng J, Wang JL. DNA End Joining: G0-ing to the Core. Biomolecules 2021; 11:biom11101487. [PMID: 34680120 PMCID: PMC8533500 DOI: 10.3390/biom11101487] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 10/05/2021] [Accepted: 10/06/2021] [Indexed: 12/28/2022] Open
Abstract
Humans have evolved a series of DNA double-strand break (DSB) repair pathways to efficiently and accurately rejoin nascently formed pairs of double-stranded DNA ends (DSEs). In G0/G1-phase cells, non-homologous end joining (NHEJ) and alternative end joining (A-EJ) operate to support covalent rejoining of DSEs. While NHEJ is predominantly utilized and collaborates extensively with the DNA damage response (DDR) to support pairing of DSEs, much less is known about A-EJ collaboration with DDR factors when NHEJ is absent. Non-cycling lymphocyte progenitor cells use NHEJ to complete V(D)J recombination of antigen receptor genes, initiated by the RAG1/2 endonuclease which holds its pair of targeted DSBs in a synapse until each specified pair of DSEs is handed off to the NHEJ DSB sensor complex, Ku. Similar to designer endonuclease DSBs, the absence of Ku allows for A-EJ to access RAG1/2 DSEs but with random pairing to complete their repair. Here, we describe recent insights into the major phases of DSB end joining, with an emphasis on synapsis and tethering mechanisms, and bring together new and old concepts of NHEJ vs. A-EJ and on RAG2-mediated repair pathway choice.
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14
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Thielhelm TP, Goncalves S, Welford SM, Mellon EA, Cohen ER, Nourbakhsh A, Fernandez-Valle C, Telischi F, Ivan ME, Dinh CT. Understanding the Radiobiology of Vestibular Schwannomas to Overcome Radiation Resistance. Cancers (Basel) 2021; 13:4575. [PMID: 34572805 PMCID: PMC8467596 DOI: 10.3390/cancers13184575] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 09/06/2021] [Accepted: 09/06/2021] [Indexed: 12/12/2022] Open
Abstract
Vestibular schwannomas (VS) are benign tumors arising from cranial nerve VIII that account for 8-10% of all intracranial tumors and are the most common tumors of the cerebellopontine angle. These tumors are typically managed with observation, radiation therapy, or microsurgical resection. Of the VS that are irradiated, there is a subset of tumors that are radioresistant and continue to grow; the mechanisms behind this phenomenon are not fully understood. In this review, the authors summarize how radiation causes cellular and DNA injury that can activate (1) checkpoints in the cell cycle to initiate cell cycle arrest and DNA repair and (2) key events that lead to cell death. In addition, we discuss the current knowledge of VS radiobiology and how it may contribute to clinical outcomes. A better understanding of VS radiobiology can help optimize existing treatment protocols and lead to new therapies to overcome radioresistance.
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Affiliation(s)
- Torin P Thielhelm
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Stefania Goncalves
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Scott M Welford
- Department of Radiation Oncology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Eric A Mellon
- Department of Radiation Oncology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Erin R Cohen
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Aida Nourbakhsh
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Cristina Fernandez-Valle
- Burnett School of Biomedical Sciences, University of Central Florida College of Medicine, Orlando, FL 32816, USA
| | - Fred Telischi
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Michael E Ivan
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Christine T Dinh
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
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15
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Magin S, Meher PK, Iliakis G. Nucleoside Analogs Radiosensitize G0 Cells by Activating DNA End Resection and Alternative End-Joining. Radiat Res 2021; 195:412-426. [PMID: 33755161 DOI: 10.1667/rade-20-00195.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 02/22/2021] [Indexed: 11/03/2022]
Abstract
Alternative end-joining (alt-EJ) is a DNA end resection-dependent, error-prone pathway utilized by vertebrate cells to repair DNA double-strand breaks (DSBs), but its engagement is linked to chromosomal translocations and genomic instability. Here, we report that when proliferating cells are exposed to ionizing radiation, treatment with nucleoside analogs (NAs) causes strong radiosensitization by increasing engagement of alt-EJ, while at the same time suppressing homologous recombination (HR) in S- and G2phase cells. This NA-mediated pathway shift may reflect a passive compensatory engagement of alt-EJ following HR suppression that is specific for S- and G2-phase cells, and/or the direct activation of alt-EJ throughout the cell cycle. To distinguish between these possibilities, we utilize here a cell culture model that exploits genetic and cell cycle-dependent inactivation of DSB repair pathways, to exclusively study alt-EJ and its modulation by NAs in murine and human cell lines. To this end, we allow LIG4-/--deficient cells to accumulate in G1/G0 phase by transfer to serum-deprived media and obtain cells deficient in c-NHEJ owing to the genetic LIG4 knockout, deficient in HR owing to the absence of S- or G2-phase cells, and compromised in their ability to carry out alt-EJ owing to their accumulation in G0. We find that in these cells irradiation and treatment with the NA, β-arabinofuranosyladenine (araA), and to a lesser degree with other NAs, promptly activates suppressed alt-EJ that now functions at levels approximating those of c-NHEJ in wild-type cells. Results at high dose (20 Gy) generated using pulsed-field gel electrophoresis (PFGE) are corroborated by results at low dose (1 Gy) generated by scoring 53BP1 foci. Strikingly, araA treatment activates a normally undetectable DNA-end-resection at DSBs, which requires ATR activity, but proceeds unimpeded after CtIP knockdown. Treatment with araA increases the formation of chromosomal aberrations and enhances radiation-induced cell killing. The results support direct stimulation of resection by NAs and alt-EJ as a mechanism of their documented radiosensitizing potential. We propose that this stimulation also occurs in repair-proficient cells and that it occurs throughout the cell cycle. It may therefore be harnessed to develop protocols combining NAs with radiation to treat human cancer.
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Affiliation(s)
- Simon Magin
- Institute of Medical Radiation Biology, University of Duisburg-Essen Medical School, Essen, Germany
| | - Prabodha Kumar Meher
- Institute of Medical Radiation Biology, University of Duisburg-Essen Medical School, Essen, Germany
| | - George Iliakis
- Institute of Medical Radiation Biology, University of Duisburg-Essen Medical School, Essen, Germany
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16
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Zhao A, Zhang J, Liu Y, Jia X, Lu X, Wang Q, Ji T, Yang L, Xue J, Gao R, Yu Y, Yang A. Synergic radiosensitization of sinomenine hydrochloride and radioiodine on human papillary thyroid carcinoma cells. Transl Oncol 2021; 14:101172. [PMID: 34243014 PMCID: PMC8273215 DOI: 10.1016/j.tranon.2021.101172] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 06/07/2021] [Accepted: 06/30/2021] [Indexed: 01/04/2023] Open
Abstract
This is the first time to study and find out that sinomenine hydrochloride and iodine-131 synergic enhance the apoptosis and regulate DNA repair and cell cycle checkpoint on papillary thyroid carcinoma cells. This is the first time to study and find out that sinomenine hydrochloride increased the radiosensitivity of papillary thyroid carcinoma cells and normal thyroid cells. This is the first time to study and find out that sinomenine hydrochloride could be a potential therapeutic radiosensitizer in papillary thyroid carcinoma radiotherapy after total thyroidectomy .
Radioiodine (131I) therapy is an important treatment for thyroid carcinoma. The response to radiotherapy sometimes limited by the development of radioresistance. Sinomenine hydrochloride(SH), was reported as a prospective radiosensitizer. This study was aim to evaluate synergic radiosensitization of SH and 131I on papillary thyroid carcinoma (PTC). We evaluated HTori-3, BCPAP and TPC-1 cells, the cell viability was evaluated by MTT. The experiment was divided into 4 groups: control group, SH (0.8 mM) group, I (131I 14.8 MBq/ml) group and ISH (SH 0.8 mM plus 131I 14.8 MBq/ml) group. Flow cytometry was used to investigate cell cycle phases and cell apoptosis. RT-PCR and western blotting were performed to determine the molecular changes. Compared to control group, SH significantly increased apoptosis and enhanced radiosensitivity of HTori-3 and PTC cells were related to the ratio of Bcl-2 to Bax protein downregulation and Fas, p21, p-ATM, p-Chk1, p-Chk2 and p53 protein expression upregulation in the ISH group (P < 0.05). Our results indicate that synergic radiosensitization of SH and iodine-131 on PTC cells and SH could be a potential therapeutic radiosensitizer in PTC radio therapy after total thyroidectomy.
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Affiliation(s)
- Aomei Zhao
- Department of Nuclear Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, PR China
| | - Jing Zhang
- Department of Nuclear Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, PR China
| | - Yan Liu
- Department of Nuclear Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, PR China
| | - Xi Jia
- Department of Nuclear Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, PR China
| | - Xueni Lu
- Department of Nuclear Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, PR China
| | - Qi Wang
- Department of Nuclear Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, PR China
| | - Ting Ji
- Department of Nuclear Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, PR China
| | - Lulu Yang
- Department of Nuclear Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, PR China
| | - Jianjun Xue
- Department of Nuclear Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, PR China
| | - Rui Gao
- Department of Nuclear Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, PR China
| | - Yan Yu
- Department of Public Health, Health Science Center of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, PR China
| | - Aimin Yang
- Department of Nuclear Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, PR China.
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17
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Fedak EA, Adler FR, Abegglen LM, Schiffman JD. ATM and ATR Activation Through Crosstalk Between DNA Damage Response Pathways. Bull Math Biol 2021; 83:38. [PMID: 33704589 DOI: 10.1007/s11538-021-00868-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 02/10/2021] [Indexed: 11/28/2022]
Abstract
Cells losing the ability to self-regulate in response to damage are a hallmark of cancer. When a cell encounters damage, regulatory pathways estimate the severity of damage and promote repair, cell cycle arrest, or apoptosis. This decision-making process would be remarkable if it were based on the total amount of damage in the cell, but because damage detection pathways vary in the rate and intensity with which they promote pro-apoptotic factors, the cell's real challenge is to reconcile dissimilar signals. Crosstalk between repair pathways, crosstalk between pro-apoptotic signaling kinases, and signals induced by damage by-products complicate the process further. The cell's response to [Formula: see text] and UV radiation neatly illustrates this concept. While these forms of radiation produce lesions associated with two different pro-apoptotic signaling kinases, ATM and ATR, recent experiments show that ATM and ATR react to both forms of radiation. To simulate the pro-apoptotic signal induced by [Formula: see text] and UV radiation, we construct a mathematical model that includes three modes of crosstalk between ATM and ATR signaling pathways: positive feedback between ATM/ATR and repair proteins, ATM and ATR mutual upregulation, and changes in lesion topology induced by replication stress or repair. We calibrate the model to agree with 21 experimental claims about ATM and ATR crosstalk. We alter the model by adding or removing specific processes and then examine the effects of each process on ATM/ATR crosstalk by recording which claims the altered model violates. Not only is this the first mathematical model of ATM/ATR crosstalk, it provides a strong argument for treating pro-apoptotic signaling as a holistic effort rather than attributing it to a single dominant kinase.
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Affiliation(s)
- Elizabeth A Fedak
- Department of Mathematics, The University of Utah, 155 Presidents Circle, Salt Lake City, UT, 84112, USA. .,Department of Oncological Sciences, Huntsman Cancer Institute, The University of Utah, 2000 Cir of Hope Dr, Salt Lake City, UT, 84112, USA.
| | - Frederick R Adler
- Department of Mathematics, The University of Utah, 155 Presidents Circle, Salt Lake City, UT, 84112, USA.,Department of Biology, The University of Utah, 257 Presidents Circle, Salt Lake City, UT, 84112, USA
| | - Lisa M Abegglen
- Department of Oncological Sciences, Huntsman Cancer Institute, The University of Utah, 2000 Cir of Hope Dr, Salt Lake City, UT, 84112, USA.,Department of Pediatrics, The University of Utah, 295 Chipeta Way, Salt Lake City, UT, 84108, USA.,PEEL Therapeutics, Inc., Salt Lake City, UT, 84108, USA
| | - Joshua D Schiffman
- Department of Oncological Sciences, Huntsman Cancer Institute, The University of Utah, 2000 Cir of Hope Dr, Salt Lake City, UT, 84112, USA.,Department of Pediatrics, The University of Utah, 295 Chipeta Way, Salt Lake City, UT, 84108, USA.,PEEL Therapeutics, Inc., Salt Lake City, UT, 84108, USA
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18
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Shang XY, Yu XQ, Yao GD, Song SJ. Daphnegiravone D from Daphne giraldii induces cell death by targeting ATR in Hep3B cells. Bioorg Chem 2021; 110:104802. [PMID: 33730672 DOI: 10.1016/j.bioorg.2021.104802] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 03/02/2021] [Indexed: 01/26/2023]
Abstract
Ataxia telangiectasia and Rad3-related protein (ATR) plays a crucial role in cancer and has become a promising target for cancer therapy. Daphnegiravone D (DGD), which could induce apoptosis and oxidative stress in hepatocellular carcinoma (HCC) cells, but the detailed target protein was still unclear. The study provided that the possible target of DGD against HCC cells was determined by isobaric labels for relative and absolute quantification (iTRAQ) assay. In all changed proteins the fold change of ATR was particularly significant. The results from GO, KEGG and PPI analysis showed that DNA damage, cell cycle, apoptosis, DNA repair related pathways changed and ATR was exactly related to them. Moreover, the mRNA and protein of ATR were both decreased in a concentration-dependent manner, and the results of molecular docking also verified the binding. Additionally, cellular thermal shift assay (CETSA) suggested that DGD could directly target at ATR protein. Furthermore, the knockdown of ATR could increase apoptosis and reactive oxygen species (ROS) which induced by DGD. Since ATR inhibitors were generally used in combination with chemotherapy drugs (especially DNA damage drugs) in clinical trials, we investigated the combined application of DGD and oxaliplatin. The results showed that DGD combined with OXA also increased the apoptosis and ROS production of Hep3B cells over either drug alone. Taken together, this study revealed that DGD targeting ATR could be a promising therapeutic strategy for the treatment of liver cancer.
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Affiliation(s)
- Xin-Yue Shang
- Key Laboratory of Computational Chemistry-Based Natural Antitumor Drug Research & Development, Liaoning Province, School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Xiao-Qi Yu
- Key Laboratory of Computational Chemistry-Based Natural Antitumor Drug Research & Development, Liaoning Province, School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Guo-Dong Yao
- Key Laboratory of Computational Chemistry-Based Natural Antitumor Drug Research & Development, Liaoning Province, School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Shenyang 110016, China.
| | - Shao-Jiang Song
- Key Laboratory of Computational Chemistry-Based Natural Antitumor Drug Research & Development, Liaoning Province, School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Shenyang 110016, China.
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19
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Marin PA, Obonaga R, Pavani RS, da Silva MS, de Araujo CB, Lima AA, Avila CC, Cestari I, Machado CR, Elias MC. ATR Kinase Is a Crucial Player Mediating the DNA Damage Response in Trypanosoma brucei. Front Cell Dev Biol 2020; 8:602956. [PMID: 33415107 PMCID: PMC7783291 DOI: 10.3389/fcell.2020.602956] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 12/02/2020] [Indexed: 12/26/2022] Open
Abstract
DNA double-strand breaks (DSBs) are among the most deleterious lesions that threaten genome integrity. To address DSBs, eukaryotic cells of model organisms have evolved a complex network of cellular pathways that are able to detect DNA damage, activate a checkpoint response to delay cell cycle progression, recruit the proper repair machinery, and resume the cell cycle once the DNA damage is repaired. Cell cycle checkpoints are primarily regulated by the apical kinases ATR and ATM, which are conserved throughout the eukaryotic kingdom. Trypanosoma brucei is a divergent pathogenic protozoan parasite that causes human African trypanosomiasis (HAT), a neglected disease that can be fatal when left untreated. The proper signaling and accuracy of DNA repair is fundamental to T. brucei not only to ensure parasite survival after genotoxic stress but also because DSBs are involved in the process of generating antigenic variations used by this parasite to evade the host immune system. DSBs trigger a strong DNA damage response and efficient repair process in T. brucei, but it is unclear how these processes are coordinated. Here, by knocking down ATR in T. brucei using two different approaches (conditional RNAi and an ATR inhibitor), we show that ATR is required to mediate intra-S and partial G1/S checkpoint responses. ATR is also involved in replication fork stalling, is critical for H2A histone phosphorylation in a small group of cells and is necessary for the recruitment and upregulation of the HR-mediated DNA repair protein RAD51 after ionizing radiation (IR) induces DSBs. In summary, this work shows that apical ATR kinase plays a central role in signal transduction and is critical for orchestrating the DNA damage response in T. brucei.
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Affiliation(s)
- Paula Andrea Marin
- Laboratory of Cell Cycle (LCC), Center of Toxins, Immune Response and Cell Signaling (CETICs), Butantan Institute, São Paulo, Brazil
| | - Ricardo Obonaga
- Laboratory of Cell Cycle (LCC), Center of Toxins, Immune Response and Cell Signaling (CETICs), Butantan Institute, São Paulo, Brazil
| | - Raphael Souza Pavani
- Laboratory of Cell Cycle (LCC), Center of Toxins, Immune Response and Cell Signaling (CETICs), Butantan Institute, São Paulo, Brazil
| | - Marcelo Santos da Silva
- Laboratory of Cell Cycle (LCC), Center of Toxins, Immune Response and Cell Signaling (CETICs), Butantan Institute, São Paulo, Brazil
| | - Christiane Bezerra de Araujo
- Laboratory of Cell Cycle (LCC), Center of Toxins, Immune Response and Cell Signaling (CETICs), Butantan Institute, São Paulo, Brazil
| | - André Arruda Lima
- Laboratory of Cell Cycle (LCC), Center of Toxins, Immune Response and Cell Signaling (CETICs), Butantan Institute, São Paulo, Brazil
| | - Carla Cristi Avila
- Laboratory of Cell Cycle (LCC), Center of Toxins, Immune Response and Cell Signaling (CETICs), Butantan Institute, São Paulo, Brazil
| | - Igor Cestari
- Institute of Parasitology, McGill University, Montreal, QC, Canada
- Division of Experimental Medicine, McGill University, Montreal, QC, Canada
| | - Carlos Renato Machado
- Biochemical and Immunology Department, Institute of Biomedical Science, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Maria Carolina Elias
- Laboratory of Cell Cycle (LCC), Center of Toxins, Immune Response and Cell Signaling (CETICs), Butantan Institute, São Paulo, Brazil
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20
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PARP Inhibition Increases the Reliance on ATR/CHK1 Checkpoint Signaling Leading to Synthetic Lethality-An Alternative Treatment Strategy for Epithelial Ovarian Cancer Cells Independent from HR Effectiveness. Int J Mol Sci 2020; 21:ijms21249715. [PMID: 33352723 PMCID: PMC7766831 DOI: 10.3390/ijms21249715] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 12/14/2020] [Accepted: 12/16/2020] [Indexed: 12/20/2022] Open
Abstract
Poly (ADP-ribose) polymerase inhibitor (PARPi, olaparib) impairs the repair of DNA single-strand breaks (SSBs), resulting in double-strand breaks (DSBs) that cannot be repaired efficiently in homologous recombination repair (HRR)-deficient cancers such as BRCA1/2-mutant cancers, leading to synthetic lethality. Despite the efficacy of olaparib in the treatment of BRCA1/2 deficient tumors, PARPi resistance is common. We hypothesized that the combination of olaparib with anticancer agents that disrupt HRR by targeting ataxia telangiectasia and Rad3-related protein (ATR) or checkpoint kinase 1 (CHK1) may be an effective strategy to reverse ovarian cancer resistance to olaparib. Here, we evaluated the effect of olaparib, the ATR inhibitor AZD6738, and the CHK1 inhibitor MK8776 alone and in combination on cell survival, colony formation, replication stress response (RSR) protein expression, DNA damage, and apoptotic changes in BRCA2 mutated (PEO-1) and HRR-proficient BRCA wild-type (SKOV-3 and OV-90) cells. Combined treatment caused the accumulation of DNA DSBs. PARP expression was associated with sensitivity to olaparib or inhibitors of RSR. Synergistic effects were weaker when olaparib was combined with CHK1i and occurred regardless of the BRCA2 status of tumor cells. Because PARPi increases the reliance on ATR/CHK1 for genome stability, the combination of PARPi with ATR inhibition suppressed ovarian cancer cell growth independently of the efficacy of HRR. The present results were obtained at sub-lethal doses, suggesting the potential of these inhibitors as monotherapy as well as in combination with olaparib.
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21
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Sridharan DM, Chien LC, Cucinotta FA, Pluth JM. Comparison of signaling profiles in the low dose range following low and high LET radiation. LIFE SCIENCES IN SPACE RESEARCH 2020; 25:28-41. [PMID: 32414491 DOI: 10.1016/j.lssr.2020.02.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 02/10/2020] [Accepted: 02/13/2020] [Indexed: 06/11/2023]
Abstract
During space travel astronauts will be exposed to a very low, mixed field of radiation containing different high LET particles of varying energies, over an extended period. Thus, defining how human cells respond to these complex low dose exposures is important in ascertaining risk. In the current study, we have chosen to investigate how low doses of three different ion's at various energies uniquely change the kinetics of three different phospho-proteins. A normal hTERT immortalized fibroblast cell line, 82-6, was exposed to a range of lower doses (0.05-0.5 Gy) of radiation of different qualities and energies (Si 1000 MeV/u, Si 300 MeV/u, Si 173 MeV/u, Si 93 MeV/u, Fe 1000 MeV/u, Fe 600 MeV/u, Fe 300 MeV/u, Ti 300 MeV/u, Ti 326 MeV/u, Ti 386 MeV/u), covering a wide span of LET's. Exposed samples were analyzed for the average intensity of signal as a fold over the geometric mean level of the sham controls. Three phospho-proteins known to localize to DNA DSBs following radiation (γH2AX, pATF2, pSMC1) were studied. The kinetics of their response was quantified by flow cytometery at 2 and 24 h post exposure. These studies reveal unique kinetic patterns based on the ion, energy, fluence and time following exposure. In addition, γH2AX phosphorylation patterns are uniquely different from phospho-proteins known to be primarily phosphorylated by ATM. This latter finding suggests that the activating kinase(s), or the phosphatases deactivating these proteins, exhibit differences in their response to various radiation qualities and/ or doses of exposure. Further studies will be needed to better define what the differing kinetics for the kinases activated by the unique radiation qualities plays in the biological effectiveness of the particle.
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Affiliation(s)
- Deepa M Sridharan
- Lawrence Berkeley National Laboratory, Life Sciences Division, Berkeley, CA 94710, United States
| | - Lung-Chang Chien
- Department of Environmental and Occupational Health, University of Nevada, Las Vegas, NV, 89154, United States
| | - Francis A Cucinotta
- Health Physics and Diagnostic Sciences, University of Nevada, Las Vegas, NV 89154, United States
| | - Janice M Pluth
- Health Physics and Diagnostic Sciences, University of Nevada, Las Vegas, NV 89154, United States.
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22
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Gralewska P, Gajek A, Marczak A, Rogalska A. Participation of the ATR/CHK1 pathway in replicative stress targeted therapy of high-grade ovarian cancer. J Hematol Oncol 2020; 13:39. [PMID: 32316968 PMCID: PMC7175546 DOI: 10.1186/s13045-020-00874-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 04/08/2020] [Indexed: 12/15/2022] Open
Abstract
Ovarian cancer is one of the most lethal gynecologic malignancies reported throughout the world. The initial, standard-of-care, adjuvant chemotherapy in epithelial ovarian cancer is usually a platinum drug, such as cisplatin or carboplatin, combined with a taxane. However, despite surgical removal of the tumor and initial high response rates to first-line chemotherapy, around 80% of women will develop cancer recurrence. Effective strategies, including chemotherapy and new research models, are necessary to improve the prognosis. The replication stress response (RSR) is characteristic of the development of tumors, including ovarian cancer. Hence, RSR pathway and DNA repair proteins have emerged as a new area for anticancer drug development. Although clinical trials have shown poly (ADP-ribose) polymerase inhibitors (PARPi) response rates of around 40% in women who carry a mutation in the BRCA1/2 genes, PARPi is responsible for tumor suppression, but not for complete tumor regression. Recent reports suggest that cells with impaired homologous recombination (HR) activities due to mutations in TP53 gene or specific DNA repair proteins are specifically sensitive to ataxia telangiectasia and Rad3-related protein (ATR) inhibitors. Replication stress activates DNA repair checkpoint proteins (ATR, CHK1), which prevent further DNA damage. This review describes the use of DNA repair checkpoint inhibitors as single agents and strategies combining these inhibitors with DNA-damaging compounds for ovarian cancer therapy, as well as the new platforms used for optimizing ovarian cancer therapy.
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Affiliation(s)
- Patrycja Gralewska
- Department of Medical Biophysics, Faculty of Biology and Environmental Protection, Institute of Biophysics, University of Lodz, Pomorska 141/143, 90-236, Lodz, Poland
| | - Arkadiusz Gajek
- Department of Medical Biophysics, Faculty of Biology and Environmental Protection, Institute of Biophysics, University of Lodz, Pomorska 141/143, 90-236, Lodz, Poland
| | - Agnieszka Marczak
- Department of Medical Biophysics, Faculty of Biology and Environmental Protection, Institute of Biophysics, University of Lodz, Pomorska 141/143, 90-236, Lodz, Poland
| | - Aneta Rogalska
- Department of Medical Biophysics, Faculty of Biology and Environmental Protection, Institute of Biophysics, University of Lodz, Pomorska 141/143, 90-236, Lodz, Poland.
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23
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Mooser C, Symeonidou IE, Leimbacher PA, Ribeiro A, Shorrocks AMK, Jungmichel S, Larsen SC, Knechtle K, Jasrotia A, Zurbriggen D, Jeanrenaud A, Leikauf C, Fink D, Nielsen ML, Blackford AN, Stucki M. Treacle controls the nucleolar response to rDNA breaks via TOPBP1 recruitment and ATR activation. Nat Commun 2020; 11:123. [PMID: 31913317 PMCID: PMC6949271 DOI: 10.1038/s41467-019-13981-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 12/10/2019] [Indexed: 01/10/2023] Open
Abstract
Induction of DNA double-strand breaks (DSBs) in ribosomal DNA (rDNA) repeats is associated with ATM-dependent repression of ribosomal RNA synthesis and large-scale reorganization of nucleolar architecture, but the signaling events that regulate these responses are largely elusive. Here we show that the nucleolar response to rDNA breaks is dependent on both ATM and ATR activity. We further demonstrate that ATM- and NBS1-dependent recruitment of TOPBP1 in the nucleoli is required for inhibition of ribosomal RNA synthesis and nucleolar segregation in response to rDNA breaks. Mechanistically, TOPBP1 recruitment is mediated by phosphorylation-dependent interactions between three of its BRCT domains and conserved phosphorylated Ser/Thr residues at the C-terminus of the nucleolar phosphoprotein Treacle. Our data thus reveal an important cooperation between TOPBP1 and Treacle in the signaling cascade that triggers transcriptional inhibition and nucleolar segregation in response to rDNA breaks.
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Affiliation(s)
- Clémence Mooser
- Department of Gynecology, University of Zurich, Wagistrasse 14, CH-8952, Schlieren, Switzerland
| | - Ioanna-Eleni Symeonidou
- Department of Gynecology, University of Zurich, Wagistrasse 14, CH-8952, Schlieren, Switzerland
| | - Pia-Amata Leimbacher
- Department of Gynecology, University of Zurich, Wagistrasse 14, CH-8952, Schlieren, Switzerland
| | - Alison Ribeiro
- Department of Gynecology, University of Zurich, Wagistrasse 14, CH-8952, Schlieren, Switzerland
| | - Ann-Marie K Shorrocks
- Department of Oncology, Medical Research Council Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DS, UK
- Cancer Research UK/Medical Research Council Oxford Institute for Radiation Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Stephanie Jungmichel
- The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Faculty of Health and Medical Sciences, Bledgamsvej 3B DK-2200, Copenhagen, Denmark
| | - Sara C Larsen
- The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Faculty of Health and Medical Sciences, Bledgamsvej 3B DK-2200, Copenhagen, Denmark
| | - Katja Knechtle
- Department of Gynecology, University of Zurich, Wagistrasse 14, CH-8952, Schlieren, Switzerland
| | - Arti Jasrotia
- Department of Gynecology, University of Zurich, Wagistrasse 14, CH-8952, Schlieren, Switzerland
| | - Diana Zurbriggen
- Department of Gynecology, University of Zurich, Wagistrasse 14, CH-8952, Schlieren, Switzerland
| | - Alain Jeanrenaud
- Department of Gynecology, University of Zurich, Wagistrasse 14, CH-8952, Schlieren, Switzerland
| | - Colin Leikauf
- Department of Gynecology, University of Zurich, Wagistrasse 14, CH-8952, Schlieren, Switzerland
| | - Daniel Fink
- Department of Gynecology, University of Zurich, Wagistrasse 14, CH-8952, Schlieren, Switzerland
| | - Michael L Nielsen
- The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Faculty of Health and Medical Sciences, Bledgamsvej 3B DK-2200, Copenhagen, Denmark
| | - Andrew N Blackford
- Department of Oncology, Medical Research Council Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DS, UK
- Cancer Research UK/Medical Research Council Oxford Institute for Radiation Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Manuel Stucki
- Department of Gynecology, University of Zurich, Wagistrasse 14, CH-8952, Schlieren, Switzerland.
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24
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Hutcherson RJ, Kemp MG. ATR kinase inhibition sensitizes quiescent human cells to the lethal effects of cisplatin but increases mutagenesis. Mutat Res 2019; 816-818:111678. [PMID: 31557599 PMCID: PMC6905468 DOI: 10.1016/j.mrfmmm.2019.111678] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 08/19/2019] [Accepted: 09/15/2019] [Indexed: 12/25/2022]
Abstract
The ATR protein kinase is known to protect cells from DNA damage induced during the replicative phase of the cell cycle. Small molecule ATR kinase inhibitors have therefore been developed to improve the effectiveness of DNA damage-based chemotherapy regimens aimed at killing rapidly proliferating tumor cells. However, whether ATR functions in a similar manner in non-replicating cells has not been examined and is important considering the fact that most cells in the body, including cancer stem cells in solid tumors, normally reside in either a quiescent or differentiated non-replicating state. Using cultured human cell lines maintained in a quiescent or slowly growing state in vitro, ATR was found to be activated following treatment with the common anti-cancer drug cisplatin in a manner dependent on the nucleotide excision repair (NER) system. Moreover, treatment with the ATR kinase inhibitors VE-821 and AZD6738 enhanced quiescent cell killing and apoptotic signaling induced by cisplatin. However, ATR kinase inhibition in quiescent cells treated with a low concentration of cisplatin also elevated the level of mutagenesis at the hypoxanthine phosphoribosyltransferase locus and resulted in increased levels of PCNA mono-ubiquitination. These results suggest that the excision gaps generated by NER may require a greater utilization of potentially mutagenic translesion synthesis polymerases in the absence of ATR kinase function. Thus, though ATR kinase inhibitors can aid in the killing of cisplatin-treated quiescent cells, such treatments may also result in a greater reliance on alternative mutagenic DNA polymerases to complete the repair of cisplatin-DNA adducts.
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Affiliation(s)
- Rebekah J Hutcherson
- Department of Pharmacology and Toxicology, Wright State University Boonshoft School of Medicine, 3640 Colonel Glenn Hwy, Dayton, OH, 45435, United States
| | - Michael G Kemp
- Department of Pharmacology and Toxicology, Wright State University Boonshoft School of Medicine, 3640 Colonel Glenn Hwy, Dayton, OH, 45435, United States.
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25
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Landsverk HB, Sandquist LE, Sridhara SC, Rødland GE, Sabino JC, de Almeida SF, Grallert B, Trinkle-Mulcahy L, Syljuåsen RG. Regulation of ATR activity via the RNA polymerase II associated factors CDC73 and PNUTS-PP1. Nucleic Acids Res 2019; 47:1797-1813. [PMID: 30541148 PMCID: PMC6393312 DOI: 10.1093/nar/gky1233] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 11/23/2018] [Accepted: 11/30/2018] [Indexed: 12/22/2022] Open
Abstract
Ataxia telangiectasia mutated and Rad3-related (ATR) kinase is a key factor activated by DNA damage and replication stress. An alternative pathway for ATR activation has been proposed to occur via stalled RNA polymerase II (RNAPII). However, how RNAPII might signal to activate ATR remains unknown. Here, we show that ATR signaling is increased after depletion of the RNAPII phosphatase PNUTS-PP1, which dephosphorylates RNAPII in its carboxy-terminal domain (CTD). High ATR signaling was observed in the absence and presence of ionizing radiation, replication stress and even in G1, but did not correlate with DNA damage or RPA chromatin loading. R-loops were enhanced, but overexpression of EGFP-RNaseH1 only slightly reduced ATR signaling after PNUTS depletion. However, CDC73, which interacted with RNAPII in a phospho-CTD dependent manner, was required for the high ATR signaling, R-loop formation and for activation of the endogenous G2 checkpoint after depletion of PNUTS. In addition, ATR, RNAPII and CDC73 co-immunoprecipitated. Our results suggest a novel pathway involving RNAPII, CDC73 and PNUTS-PP1 in ATR signaling and give new insight into the diverse functions of ATR.
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Affiliation(s)
- Helga B Landsverk
- Department of Radiation Biology, Institute for Cancer Research, Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
| | - Lise E Sandquist
- Department of Radiation Biology, Institute for Cancer Research, Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
| | - Sreerama C Sridhara
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
| | - Gro Elise Rødland
- Department of Radiation Biology, Institute for Cancer Research, Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
| | - João C Sabino
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
| | - Sérgio F de Almeida
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
| | - Beata Grallert
- Department of Radiation Biology, Institute for Cancer Research, Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
| | - Laura Trinkle-Mulcahy
- Department of Cellular and Molecular Medicine and Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Randi G Syljuåsen
- Department of Radiation Biology, Institute for Cancer Research, Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
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26
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Lin Y, Bai L, Cupello S, Hossain MA, Deem B, McLeod M, Raj J, Yan S. APE2 promotes DNA damage response pathway from a single-strand break. Nucleic Acids Res 2019; 46:2479-2494. [PMID: 29361157 PMCID: PMC5861430 DOI: 10.1093/nar/gky020] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 01/09/2018] [Indexed: 02/06/2023] Open
Abstract
As the most common type of DNA damage, DNA single-strand breaks (SSBs) are primarily repaired by the SSB repair mechanism. If not repaired properly or promptly, unrepaired SSBs lead to genome stability and have been implicated in cancer and neurodegenerative diseases. However, it remains unknown how unrepaired SSBs are recognized by DNA damage response (DDR) pathway, largely because of the lack of a feasible experimental system. Here, we demonstrate evidence showing that an ATR-dependent checkpoint signaling is activated by a defined plasmid-based site-specific SSB structure in Xenopus HSS (high-speed supernatant) system. Notably, the distinct SSB signaling requires APE2 and canonical checkpoint proteins, including ATR, ATRIP, TopBP1, Rad9 and Claspin. Importantly, the SSB-induced ATR DDR is essential for SSB repair. We and others show that APE2 interacts with PCNA via its PIP box and preferentially interacts with ssDNA via its C-terminus Zf–GRF domain, a conserved motif found in >100 proteins involved in DNA/RNA metabolism. Here, we identify a novel mode of APE2–PCNA interaction via APE2 Zf–GRF and PCNA C-terminus. Mechanistically, the APE2 Zf–GRF–PCNA interaction facilitates 3′-5′ SSB end resection, checkpoint protein complex assembly, and SSB-induced DDR pathway. Together, we propose that APE2 promotes ATR–Chk1 DDR pathway from a single-strand break.
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Affiliation(s)
- Yunfeng Lin
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - Liping Bai
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - Steven Cupello
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - Md Akram Hossain
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - Bradley Deem
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - Melissa McLeod
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - Jude Raj
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - Shan Yan
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
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27
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Bigot N, Day M, Baldock RA, Watts FZ, Oliver AW, Pearl LH. Phosphorylation-mediated interactions with TOPBP1 couple 53BP1 and 9-1-1 to control the G1 DNA damage checkpoint. eLife 2019; 8:e44353. [PMID: 31135337 PMCID: PMC6561707 DOI: 10.7554/elife.44353] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 05/25/2019] [Indexed: 12/30/2022] Open
Abstract
Coordination of the cellular response to DNA damage is organised by multi-domain 'scaffold' proteins, including 53BP1 and TOPBP1, which recognise post-translational modifications such as phosphorylation, methylation and ubiquitylation on other proteins, and are themselves carriers of such regulatory signals. Here we show that the DNA damage checkpoint regulating S-phase entry is controlled by a phosphorylation-dependent interaction of 53BP1 and TOPBP1. BRCT domains of TOPBP1 selectively bind conserved phosphorylation sites in the N-terminus of 53BP1. Mutation of these sites does not affect formation of 53BP1 or ATM foci following DNA damage, but abolishes recruitment of TOPBP1, ATR and CHK1 to 53BP1 damage foci, abrogating cell cycle arrest and permitting progression into S-phase. TOPBP1 interaction with 53BP1 is structurally complimentary to its interaction with RAD9-RAD1-HUS1, allowing these damage recognition factors to bind simultaneously to the same TOPBP1 molecule and cooperate in ATR activation in the G1 DNA damage checkpoint.
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Affiliation(s)
- Nicolas Bigot
- Cancer Research UK DNA Repair Enzymes Group, Genome Damage and Stability Centre, School of Life SciencesUniversity of SussexBrightonUnited Kingdom
| | - Matthew Day
- Cancer Research UK DNA Repair Enzymes Group, Genome Damage and Stability Centre, School of Life SciencesUniversity of SussexBrightonUnited Kingdom
| | - Robert A Baldock
- Genome Damage and Stability Centre, School of Life SciencesUniversity of SussexBrightonUnited Kingdom
| | - Felicity Z Watts
- Genome Damage and Stability Centre, School of Life SciencesUniversity of SussexBrightonUnited Kingdom
| | - Antony W Oliver
- Cancer Research UK DNA Repair Enzymes Group, Genome Damage and Stability Centre, School of Life SciencesUniversity of SussexBrightonUnited Kingdom
| | - Laurence H Pearl
- Cancer Research UK DNA Repair Enzymes Group, Genome Damage and Stability Centre, School of Life SciencesUniversity of SussexBrightonUnited Kingdom
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28
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So CC, Ramachandran S, Martin A. E3 Ubiquitin Ligases RNF20 and RNF40 Are Required for Double-Stranded Break (DSB) Repair: Evidence for Monoubiquitination of Histone H2B Lysine 120 as a Novel Axis of DSB Signaling and Repair. Mol Cell Biol 2019; 39:e00488-18. [PMID: 30692271 PMCID: PMC6447412 DOI: 10.1128/mcb.00488-18] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 11/13/2018] [Accepted: 01/23/2019] [Indexed: 01/13/2023] Open
Abstract
Histone posttranslational modifications play fundamental roles in the regulation of double-stranded DNA break (DSB) repair. RNF20/RNF40-mediated monoubiquitination of histone H2B on lysine 120 (H2Bub) has been suggested as a potential mediator of DSB repair, although the nature and function of this posttranslational modification remain enigmatic. In this report, we demonstrate that RNF20 and RNF40 are required for DSB repair leading to homologous recombination (HR) and class switch recombination, a process driven by nonhomologous end joining (NHEJ), in mouse B cells. These findings suggest a role for RNF20 and RNF40 in DSB repair proximal to NHEJ/HR pathway choice and likely in the signaling of DSBs. We found that DSBs led to a global increase in H2Bub but not the transcription-associated posttranslational modifications H3K4me3 and H3K79me2. We also found that H2AX phosphorylation was dispensable for H2Bub and that ATM and ATR jointly regulate ionizing radiation (IR)-induced H2Bub. Together, our results suggest that RNF20, RNF40, and H2Bub may represent a novel pathway for DSB sensing and repair.
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Affiliation(s)
- Clare C So
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
| | | | - Alberto Martin
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
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29
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Bukhari AB, Lewis CW, Pearce JJ, Luong D, Chan GK, Gamper AM. Inhibiting Wee1 and ATR kinases produces tumor-selective synthetic lethality and suppresses metastasis. J Clin Invest 2019; 129:1329-1344. [PMID: 30645202 DOI: 10.1172/jci122622] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 01/08/2019] [Indexed: 01/01/2023] Open
Abstract
We used the cancer-intrinsic property of oncogene-induced DNA damage as the base for a conditional synthetic lethality approach. To target mechanisms important for cancer cell adaptation to genotoxic stress and thereby to achieve cancer cell-specific killing, we combined inhibition of the kinases ATR and Wee1. Wee1 regulates cell cycle progression, whereas ATR is an apical kinase in the DNA-damage response. In an orthotopic breast cancer model, tumor-selective synthetic lethality of the combination of bioavailable ATR and Wee1 inhibitors led to tumor remission and inhibited metastasis with minimal side effects. ATR and Wee1 inhibition had a higher synergistic effect in cancer stem cells than in bulk cancer cells, compensating for the lower sensitivity of cancer stem cells to the individual drugs. Mechanistically, the combination treatment caused cells with unrepaired or under-replicated DNA to enter mitosis leading to mitotic catastrophe. As these inhibitors of ATR and Wee1 are already in phase I/II clinical trials, this knowledge could soon be translated into the clinic, especially as we showed that the combination treatment targets a wide range of tumor cells. Particularly, the antimetastatic effect of combined Wee1/ATR inhibition and the low toxicity of ATR inhibitors compared with Chk1 inhibitors have great clinical potential.
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30
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Jarrett SG, Carter KM, Bautista RM, He D, Wang C, D'Orazio JA. Sirtuin 1-mediated deacetylation of XPA DNA repair protein enhances its interaction with ATR protein and promotes cAMP-induced DNA repair of UV damage. J Biol Chem 2018; 293:19025-19037. [PMID: 30327428 DOI: 10.1074/jbc.ra118.003940] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 10/12/2018] [Indexed: 12/31/2022] Open
Abstract
Blunted melanocortin 1 receptor (MC1R) signaling promotes melanocyte genomic instability in part by attenuating cAMP-mediated DNA repair responses, particularly nucleotide excision repair (NER), which recognizes and clears mutagenic photodamage. cAMP-enhanced NER is mediated by interactions between the ataxia telangiectasia-mutated and Rad3-related (ATR) and xeroderma pigmentosum complementation group A (XPA) proteins. We now report a critical role for sirtuin 1 (SIRT1) in regulating ATR-mediated phosphorylation of XPA. SIRT1 deacetylates XPA at residues Lys-63, Lys-67, and Lys-215 to promote interactions with ATR. Mutant XPA containing acetylation mimetics at residues Lys-63, Lys-67, and Lys-215 exhibit blunted UV-dependent ATR-XPA interactions even in the presence of cAMP signals. ATR-mediated phosphorylation of XPA on Ser-196 enhances cAMP-mediated optimization of NER and is promoted by SIRT1-mediated deacetylation of XPA on Lys-63, Lys-67, and Lys-215. Interference with ATR-mediated XPA phosphorylation at Ser-196 by persistent acetylation of XPA at Lys-63, Lys-67, and Lys-215 delays repair of UV-induced DNA damage and attenuates cAMP-enhanced NER. Our study identifies a regulatory ATR-SIRT1-XPA axis in cAMP-mediated regulation melanocyte genomic stability, involving SIRT1-mediated deacetylation (Lys-63, Lys-67, and Lys-215) and ATR-dependent phosphorylation (Ser-196) post-translational modifications of the core NER factor XPA.
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Affiliation(s)
- Stuart G Jarrett
- From the Markey Cancer Center and .,the Departments of Toxicology and Cancer Biology
| | | | | | - Daheng He
- From the Markey Cancer Center and.,Biostatistics and Bioinformatics, and
| | - Chi Wang
- From the Markey Cancer Center and.,Biostatistics and Bioinformatics, and
| | - John A D'Orazio
- From the Markey Cancer Center and .,the Departments of Toxicology and Cancer Biology.,Pediatrics, University of Kentucky College of Medicine, Lexington, Kentucky 40536
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31
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Zhang D, Dong Y, Zhao Y, Zhou C, Qian Y, Hegde ML, Wang H, Han S. Sinomenine hydrochloride sensitizes cervical cancer cells to ionizing radiation by impairing DNA damage response. Oncol Rep 2018; 40:2886-2895. [PMID: 30226618 PMCID: PMC6151895 DOI: 10.3892/or.2018.6693] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 09/03/2018] [Indexed: 02/01/2023] Open
Abstract
The use of plant-based compounds derived from traditional medicine to improve human diseases has been gaining momentum, due to their high bioavailability and moderate adverse effects. Sinomenine is one such biomonomer alkali compound derived from Sinomenium acutum and is known for its anti-inflammatory and antitumor effects. However, the molecular mechanism(s) of its antitumor properties are not fully characterized. In the present study, we evaluated the radiosensitizing effects of the water-soluble sinomenine, sinomenine hydrochloride (SH) in human cervical cancer cell line (HeLa). SH sensitized HeLa cells to ionizing radiation (IR) by promoting accumulation of IR-induced DNA double-strand breaks (DSBs) and also by interfering with DNA damage checkpoint activation. We then investigated the molecular mechanisms underlying the SH-mediated cellular sensitization to IR and found that SH inhibited the expression of DNA damage response (DDR) factors Ku80 and Rad51 at the transcription level. Finally, the radiosensitizing activity of SH was confirmed in a cervical cancer mouse xenograft model. The combinatorial treatment of SH and IR significantly slowed the tumor growth rate compared with IR alone. Collectively, our study not only provides molecular insights into the novel role of SH in cellular response to IR, but also suggests a therapeutic potential of SH as a radiosensitizer in cervical cancer therapy.
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Affiliation(s)
- Dan Zhang
- Department of Oncology, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Yiping Dong
- Department of Oncology, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Ying Zhao
- Department of Oncology, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Congya Zhou
- Department of Oncology, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Yuanjie Qian
- Department of Oncology, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Muralidhar L Hegde
- Department of Radiation Oncology, Methodist Hospital Research Institute, Houston, TX 77030, USA
| | - Haibo Wang
- Department of Oncology, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Suxia Han
- Department of Oncology, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
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32
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Vendetti FP, Karukonda P, Clump DA, Teo T, Lalonde R, Nugent K, Ballew M, Kiesel BF, Beumer JH, Sarkar SN, Conrads TP, O'Connor MJ, Ferris RL, Tran PT, Delgoffe GM, Bakkenist CJ. ATR kinase inhibitor AZD6738 potentiates CD8+ T cell-dependent antitumor activity following radiation. J Clin Invest 2018; 128:3926-3940. [PMID: 29952768 DOI: 10.1172/jci96519] [Citation(s) in RCA: 135] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 06/26/2018] [Indexed: 12/21/2022] Open
Abstract
DNA-damaging chemotherapy and radiation therapy are integrated into the treatment paradigm of the majority of cancer patients. Recently, immunotherapy that targets the immunosuppressive interaction between programmed death 1 (PD-1) and its ligand PD-L1 has been approved for malignancies including non-small cell lung cancer, melanoma, and head and neck squamous cell carcinoma. ATR is a DNA damage-signaling kinase activated at damaged replication forks, and ATR kinase inhibitors potentiate the cytotoxicity of DNA-damaging chemotherapies. We show here that the ATR kinase inhibitor AZD6738 combines with conformal radiation therapy to attenuate radiation-induced CD8+ T cell exhaustion and potentiate CD8+ T cell activity in mouse models of Kras-mutant cancer. Mechanistically, AZD6738 blocks radiation-induced PD-L1 upregulation on tumor cells and dramatically decreases the number of tumor-infiltrating Tregs. Remarkably, AZD6738 combines with conformal radiation therapy to generate immunologic memory in complete responder mice. Our work raises the possibility that a single pharmacologic agent may enhance the cytotoxic effects of radiation while concurrently potentiating radiation-induced antitumor immune responses.
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Affiliation(s)
- Frank P Vendetti
- Department of Radiation Oncology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Pooja Karukonda
- Department of Radiation Oncology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - David A Clump
- Department of Radiation Oncology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Troy Teo
- Department of Radiation Oncology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Ronald Lalonde
- Department of Radiation Oncology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Katriana Nugent
- Departments of Radiation Oncology and Molecular Radiation Sciences, Medical Oncology and Urology, Program in Cellular and Molecular Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Matthew Ballew
- Departments of Radiation Oncology and Molecular Radiation Sciences, Medical Oncology and Urology, Program in Cellular and Molecular Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Brian F Kiesel
- Department of Pharmaceutical Sciences, University of Pittsburgh School of Pharmacy, Pittsburgh, Pennsylvania, USA
| | - Jan H Beumer
- Department of Pharmaceutical Sciences, University of Pittsburgh School of Pharmacy, Pittsburgh, Pennsylvania, USA
| | - Saumendra N Sarkar
- Department of Microbiology and Molecular Genetics and.,Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Thomas P Conrads
- Inova Schar Cancer Institute, Inova Center for Personalized Health, Falls Church, Virginia, USA
| | - Mark J O'Connor
- DNA Damage Response Biology Area, Oncology IMED, AstraZeneca, Cambridge, United Kingdom
| | - Robert L Ferris
- Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,Department of Otolaryngology and
| | - Phuoc T Tran
- Departments of Radiation Oncology and Molecular Radiation Sciences, Medical Oncology and Urology, Program in Cellular and Molecular Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | | | - Christopher J Bakkenist
- Department of Radiation Oncology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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33
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Henssen AG, Reed C, Jiang E, Garcia HD, von Stebut J, MacArthur IC, Hundsdoerfer P, Kim JH, de Stanchina E, Kuwahara Y, Hosoi H, Ganem NJ, Dela Cruz F, Kung AL, Schulte JH, Petrini JH, Kentsis A. Therapeutic targeting of PGBD5-induced DNA repair dependency in pediatric solid tumors. Sci Transl Med 2018; 9:9/414/eaam9078. [PMID: 29093183 DOI: 10.1126/scitranslmed.aam9078] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 07/15/2017] [Accepted: 09/25/2017] [Indexed: 12/16/2022]
Abstract
Despite intense efforts, the cure rates of childhood and adult solid tumors are not satisfactory. Resistance to intensive chemotherapy is common, and targets for molecular therapies are largely undefined. We have found that the majority of childhood solid tumors, including rhabdoid tumors, neuroblastoma, medulloblastoma, and Ewing sarcoma, express an active DNA transposase, PGBD5, that can promote site-specific genomic rearrangements in human cells. Using functional genetic approaches, we discovered that mouse and human cells deficient in nonhomologous end joining (NHEJ) DNA repair cannot tolerate the expression of PGBD5. In a chemical screen of DNA damage signaling inhibitors, we identified AZD6738 as a specific sensitizer of PGBD5-dependent DNA damage and apoptosis. We found that expression of PGBD5, but not its nuclease activity-deficient mutant, was sufficient to induce sensitivity to AZD6738. Depletion of endogenous PGBD5 conferred resistance to AZD6738 in human tumor cells. PGBD5-expressing tumor cells accumulated unrepaired DNA damage in response to AZD6738 treatment and underwent apoptosis in both dividing and G1-phase cells in the absence of immediate DNA replication stress. Accordingly, AZD6738 exhibited nanomolar potency against most neuroblastoma, medulloblastoma, Ewing sarcoma, and rhabdoid tumor cells tested while sparing nontransformed human and mouse embryonic fibroblasts in vitro. Finally, treatment with AZD6738 induced apoptosis and regression of human neuroblastoma and medulloblastoma tumors engrafted in immunodeficient mice in vivo. This effect was potentiated by combined treatment with cisplatin, including substantial antitumor activity against patient-derived primary neuroblastoma xenografts. These findings delineate a therapeutically actionable synthetic dependency induced in PGBD5-expressing solid tumors.
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Affiliation(s)
- Anton G Henssen
- Molecular Pharmacology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.,Berlin Institute of Health, 10178 Berlin, Germany.,Department of Pediatric Oncology and Hematology, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany.,German Cancer Consortium (DKTK), 10117 Berlin, Germany
| | - Casie Reed
- Molecular Pharmacology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Eileen Jiang
- Molecular Pharmacology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Heathcliff Dorado Garcia
- Department of Pediatric Oncology and Hematology, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Jennifer von Stebut
- Department of Pediatric Oncology and Hematology, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Ian C MacArthur
- Molecular Pharmacology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Patrick Hundsdoerfer
- Berlin Institute of Health, 10178 Berlin, Germany.,Department of Pediatric Oncology and Hematology, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Jun Hyun Kim
- Molecular Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Elisa de Stanchina
- Antitumor Assessment Core Facility, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Yasumichi Kuwahara
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Hajime Hosoi
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Neil J Ganem
- Section of Hematology and Medical Oncology, Department of Pharmacology, Boston University School of Medicine, Boston, MA 02215, USA
| | - Filemon Dela Cruz
- Department of Pediatrics, Weill Cornell Medical College of Cornell University and Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Andrew L Kung
- Department of Pediatrics, Weill Cornell Medical College of Cornell University and Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Johannes H Schulte
- Berlin Institute of Health, 10178 Berlin, Germany.,Department of Pediatric Oncology and Hematology, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany.,German Cancer Consortium (DKTK), 10117 Berlin, Germany.,Deutsches Krebsforschungszentrum Heidelberg, 69120 Heidelberg, Germany
| | - John H Petrini
- Molecular Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Alex Kentsis
- Molecular Pharmacology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA. .,Department of Pediatrics, Weill Cornell Medical College of Cornell University and Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
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34
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Bøe CA, Håland TW, Boye E, Syljuåsen RG, Grallert B. A novel role for ATR/Rad3 in G1 phase. Sci Rep 2018; 8:6880. [PMID: 29720710 PMCID: PMC5931961 DOI: 10.1038/s41598-018-25238-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 04/12/2018] [Indexed: 12/29/2022] Open
Abstract
Checkpoint kinases are important in cellular surveillance pathways that help cells to cope with DNA damage and protect their genomes. In cycling cells, DNA replication is one of the most sensitive processes and therefore all organisms carefully regulate replication initiation and progression. The checkpoint kinase ATR plays important roles both in response to DNA damage and replication stress, and ATR inhibitors are currently in clinical trials for cancer treatment. Therefore, it is important to understand the roles of ATR in detail. Here we show that the fission yeast homologue Rad3 and the human ATR regulate events also in G1 phase in an unperturbed cell cycle. Rad3Δ mutants or human cells exposed to ATR inhibitor in G1 enter S phase prematurely, which results in increased DNA damage. Furthermore, ATR inhibition in a single G1 reduces clonogenic survival, demonstrating that long-term effects of ATR inhibition during G1 are deleterious for the cell. Interestingly, ATR inhibition through G1 and S phase reduces survival in an additive manner, strongly arguing that different functions of ATR are targeted in the different cell-cycle phases. We propose that potential effects of ATR inhibitors in G1 should be considered when designing future treatment protocols with such inhibitors.
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Affiliation(s)
- Cathrine A Bøe
- Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Tine W Håland
- Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Erik Boye
- Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Randi G Syljuåsen
- Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Beáta Grallert
- Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway.
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35
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ATR kinase inhibition induces unscheduled origin firing through a Cdc7-dependent association between GINS and And-1. Nat Commun 2017; 8:1392. [PMID: 29123096 PMCID: PMC5680267 DOI: 10.1038/s41467-017-01401-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 09/13/2017] [Indexed: 11/09/2022] Open
Abstract
ATR kinase activity slows replication forks and prevents origin firing in damaged cells. Here we describe proteomic analyses that identified mechanisms through which ATR kinase inhibitors induce unscheduled origin firing in undamaged cells. ATR-Chk1 inhibitor-induced origin firing is mediated by Cdc7 kinase through previously undescribed phosphorylations on GINS that induce an association between GINS and And-1. ATR-Chk1 inhibitor-induced origin firing is blocked by prior exposure to DNA damaging agents showing that the prevention of origin firing does not require ongoing ATR activity. In contrast, ATR-Chk1 inhibitor-induced origins generate additional replication forks that are targeted by subsequent exposure to DNA damaging agents. Thus, the sequence of administration of an ATR kinase inhibitor and a DNA damaging agent impacts the DNA damage induced by the combination. Our experiments identify competing ATR and Cdc7 kinase-dependent mechanisms at replication origins in human cells.
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36
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Meng G, Tang X, Yang Z, Benesch MGK, Marshall A, Murray D, Hemmings DG, Wuest F, McMullen TPW, Brindley DN. Implications for breast cancer treatment from increased autotaxin production in adipose tissue after radiotherapy. FASEB J 2017; 31:4064-4077. [PMID: 28539367 DOI: 10.1096/fj.201700159r] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 04/08/2017] [Indexed: 01/08/2023]
Abstract
We have previously established that adipose tissue adjacent to breast tumors becomes inflamed by tumor-derived cytokines. This stimulates autotaxin (ATX) secretion from adipocytes, whereas breast cancer cells produce insignificant ATX. Lysophosphatidate produced by ATX promotes inflammatory cytokine secretion in a vicious inflammatory cycle, which increases tumor growth and metastasis and decreases response to chemotherapy. We hypothesized that damage to adipose tissue during radiotherapy for breast cancer should promote lysophosphatidic acid (LPA) signaling and further inflammatory signaling, which could potentially protect cancer cells from subsequent fractions of radiation therapy. To test this hypothesis, we exposed rat and human adipose tissue to radiation doses (0.25-5 Gy) that were expected during radiotherapy. This exposure increased mRNA levels for ATX, cyclooxygenase-2, IL-1β, IL-6, IL-10, TNF-α, and LPA1 and LPA2 receptors by 1.8- to 5.1-fold after 4 to 48 h. There were also 1.5- to 2.5-fold increases in the secretion of ATX and 14 inflammatory mediators after irradiating at 1 Gy. Inhibition of the radiation-induced activation of NF-κB, cyclooxygenase-2, poly (ADP-ribose) polymerase-1, or ataxia telangiectasia and Rad3-related protein blocked inflammatory responses to γ-radiation. Consequently, collateral damage to adipose tissue during radiotherapy could establish a comprehensive wound-healing response that involves increased signaling by LPA, cyclooxygenase-2, and other inflammatory mediators that could decrease the efficacy of further radiotherapy or chemotherapy.-Meng, G., Tang, X., Yang, Z., Benesch, M. G. K., Marshall, A., Murray, D., Hemmings, D. G., Wuest, F., McMullen, T. P. W., Brindley, D. N. Implications for breast cancer treatment from increased autotaxin production in adipose tissue after radiotherapy.
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Affiliation(s)
- Guanmin Meng
- Signal Transduction Research Group, Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada.,Department of Clinical Laboratory, Tongde Hospital of Zhejiang Province, Hangzhou, China
| | - Xiaoyun Tang
- Signal Transduction Research Group, Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Zelei Yang
- Signal Transduction Research Group, Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Matthew G K Benesch
- Signal Transduction Research Group, Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Alison Marshall
- Department of Oncology, Cross Cancer Institute, University of Alberta, Edmonton, Alberta, Canada
| | - David Murray
- Department of Oncology, Cross Cancer Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Denise G Hemmings
- Department of Obstetrics and Gynecology, University of Alberta, Edmonton, Alberta, Canada.,Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Frank Wuest
- Department of Oncology, Cross Cancer Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Todd P W McMullen
- Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - David N Brindley
- Signal Transduction Research Group, Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada;
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37
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Kiesel BF, Shogan JC, Rachid M, Parise RA, Vendetti FP, Bakkenist CJ, Beumer JH. LC-MS/MS assay for the simultaneous quantitation of the ATM inhibitor AZ31 and the ATR inhibitor AZD6738 in mouse plasma. J Pharm Biomed Anal 2017; 138:158-165. [PMID: 28213176 DOI: 10.1016/j.jpba.2017.01.055] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 01/18/2017] [Accepted: 01/29/2017] [Indexed: 12/14/2022]
Abstract
The ATM kinase inhibitor AZ31 and ATR kinase inhibitor AZD6738 are in various phases of preclinical and clinical evaluation for their ability to potentiate chemoradiation. To support the preclinical evaluation of their pharmacokinetics, we developed and validated an LC-MS/MS assay for the simultaneous quantification of AZ31 and AZD6738 in mouse plasma. A "dilute and shoot" method was used to precipitate proteins from a sample volume of 50μL. Chromatographic separation was achieved using a Phenomenex Polar-RP column and a gradient mobile phase consisting of methanol-water with 0.1% formic acid. Detection was accomplished using a Waters Quattro Micro mass spectrometer in positive ionization mode. The assay utilizing 50μL sample was linear from 10 to 5000ng/mL and determined to be both accurate (-8.2 to 8.6%) and precise (<5.4% CV) and achieved the criteria for U.S. FDA guidance for bioanalytical method validation. Quantification was achieved in mouse tissue homogenate using a separate 200μL sample preparation. This LC-MS/MS assay will be essential for determining the tissue distribution and pharmacokinetics in future mouse studies.
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Affiliation(s)
- Brian F Kiesel
- Cancer Therapeutics Program, University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA; Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jeffrey C Shogan
- Department of Radiation Oncology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Madani Rachid
- Cancer Therapeutics Program, University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA
| | - Robert A Parise
- Cancer Therapeutics Program, University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA
| | - Frank P Vendetti
- Department of Radiation Oncology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Christopher J Bakkenist
- Department of Radiation Oncology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Jan H Beumer
- Cancer Therapeutics Program, University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA; Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA, USA; Division of Hematology-Oncology, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
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38
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Griffith C, Dayoub AS, Jaranatne T, Alatrash N, Mohamedi A, Abayan K, Breitbach ZS, Armstrong DW, MacDonnell FM. Cellular and cell-free studies of catalytic DNA cleavage by ruthenium polypyridyl complexes containing redox-active intercalating ligands. Chem Sci 2017; 8:3726-3740. [PMID: 28553531 PMCID: PMC5428021 DOI: 10.1039/c6sc04094b] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 03/08/2017] [Indexed: 01/21/2023] Open
Abstract
The ruthenium(ii) polypyridyl complexes (RPCs), [(phen)2Ru(tatpp)]2+ (32+ ) and [(phen)2Ru(tatpp)Ru(phen)2]4+ (44+ ) are shown to cleave DNA in cell-free studies in the presence of a mild reducing agent, i.e. glutathione (GSH), in a manner that is enhanced upon lowering the [O2]. Reactive oxygen species (ROS) are involved in the cleavage process as hydroxy radical scavengers attenuate the cleavage activity. Cleavage experiments in the presence of superoxide dismutase (SOD) and catalase reveal a central role for H2O2 as the immediate precursor for hydroxy radicals. A mechanism is proposed which explains the inverse [O2] dependence and ROS data and involves redox cycling between three DNA-bound redox isomers of 32+ or 44+ . Cultured non-small cell lung cancer cells (H358) are sensitive to 32+ and 44+ with IC50 values of 13 and 15 μM, respectively, and xenograft H358 tumors in nude mice show substantial (∼80%) regression relative to untreated tumors when the mice are treated with enantiopure versions of 32+ and 44+ (Yadav et al. Mol Cancer Res, 2013, 12, 643). Fluorescence microscopy of H358 cells treated with 15 μM 44+ reveals enhanced intracellular ROS production in as little as 2 h post treatment. Detection of phosphorylated ATM via immunofluorescence within 2 h of treatment with 44+ reveals initiation of the DNA damage repair machinery due to the ROS insult and DNA double strand breaks (DSBs) in the nuclei of H358 cells and is confirmed using the γH2AX assay. The cell data for 32+ is less clear but DNA damage occurs. Notably, cells treated with [Ru(diphenylphen)3]2+ (IC50 1.7 μM) show no extra ROS production and no DNA damage by either the pATM or γH2AX even after 22 h. The enhanced DNA cleavage under low [O2] (4 μM) seen in cell-free cleavage assays of 32+ and 44+ is only partially reflected in the cytotoxicity of 32+ and 44+ in H358, HCC2998, HOP-62 and Hs766t under hypoxia (1.1% O2) relative to normoxia (18% O2). Cells treated with RPC 32+ show up to a two-fold enhancement in the IC50 under hypoxia whereas cells treated with RPC 44+ gave the same IC50 whether under hypoxia or normoxia.
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Affiliation(s)
- Cynthia Griffith
- Department of Chemistry and Biochemistry , University of Texas at Arlington , Arlington , TX 76019 , USA .
| | - Adam S Dayoub
- Department of Chemistry and Biochemistry , University of Texas at Arlington , Arlington , TX 76019 , USA .
| | - Thamara Jaranatne
- Department of Chemistry and Biochemistry , University of Texas at Arlington , Arlington , TX 76019 , USA .
| | - Nagham Alatrash
- Department of Chemistry and Biochemistry , University of Texas at Arlington , Arlington , TX 76019 , USA .
| | - Ali Mohamedi
- Department of Chemistry and Biochemistry , University of Texas at Arlington , Arlington , TX 76019 , USA .
| | - Kenneth Abayan
- Department of Chemistry and Biochemistry , University of Texas at Arlington , Arlington , TX 76019 , USA .
| | - Zachary S Breitbach
- Department of Chemistry and Biochemistry , University of Texas at Arlington , Arlington , TX 76019 , USA .
| | - Daniel W Armstrong
- Department of Chemistry and Biochemistry , University of Texas at Arlington , Arlington , TX 76019 , USA .
| | - Frederick M MacDonnell
- Department of Chemistry and Biochemistry , University of Texas at Arlington , Arlington , TX 76019 , USA .
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Pharmacologic ATM but not ATR kinase inhibition abrogates p21-dependent G1 arrest and promotes gastrointestinal syndrome after total body irradiation. Sci Rep 2017; 7:41892. [PMID: 28145510 PMCID: PMC5286430 DOI: 10.1038/srep41892] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 12/28/2016] [Indexed: 01/03/2023] Open
Abstract
We show that ATM kinase inhibition using AZ31 prior to 9 or 9.25 Gy total body irradiation (TBI) reduced median time to moribund in mice to 8 days. ATR kinase inhibition using AZD6738 prior to TBI did not reduce median time to moribund. The striking finding associated with ATM inhibition prior to TBI was increased crypt loss within the intestine epithelium. ATM inhibition reduced upregulation of p21, an inhibitor of cyclin-dependent kinases, and blocked G1 arrest after TBI thereby increasing the number of S phase cells in crypts in wild-type but not Cdkn1a(p21CIP/WAF1)−/− mice. In contrast, ATR inhibition increased upregulation of p21 after TBI. Thus, ATM activity is essential for p21-dependent arrest while ATR inhibition may potentiate arrest in crypt cells after TBI. Nevertheless, ATM inhibition reduced median time to moribund in Cdkn1a(p21CIP/WAF1)−/− mice after TBI. ATM inhibition also increased cell death in crypts at 4 h in Cdkn1a(p21CIP/WAF1)−/−, earlier than at 24 h in wild-type mice after TBI. In contrast, ATR inhibition decreased cell death in crypts in Cdkn1a(p21CIP/WAF1)−/− mice at 4 h after TBI. We conclude that ATM activity is essential for p21-dependent and p21-independent mechanisms that radioprotect intestinal crypts and that ATM inhibition promotes GI syndrome after TBI.
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Sastre-Moreno G, Pryor JM, Moreno-Oñate M, Herrero-Ruiz AM, Cortés-Ledesma F, Blanco L, Ramsden DA, Ruiz JF. Regulation of human polλ by ATM-mediated phosphorylation during non-homologous end joining. DNA Repair (Amst) 2017; 51:31-45. [PMID: 28109743 DOI: 10.1016/j.dnarep.2017.01.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 01/05/2017] [Accepted: 01/09/2017] [Indexed: 11/26/2022]
Abstract
DNA double strand breaks (DSBs) trigger a variety of cellular signaling processes, collectively termed the DNA-damage response (DDR), that are primarily regulated by protein kinase ataxia-telangiectasia mutated (ATM). Among DDR activated processes, the repair of DSBs by non-homologous end joining (NHEJ) is essential. The proper coordination of NHEJ factors is mainly achieved through phosphorylation by an ATM-related kinase, the DNA-dependent protein kinase catalytic subunit (DNA-PKcs), although the molecular basis for this regulation has yet to be fully elucidated. In this study we identify the major NHEJ DNA polymerase, DNA polymerase lambda (Polλ), as a target for both ATM and DNA-PKcs in human cells. We show that Polλ is efficiently phosphorylated by DNA-PKcs in vitro and predominantly by ATM after DSB induction with ionizing radiation (IR) in vivo. We identify threonine 204 (T204) as a main target for ATM/DNA-PKcs phosphorylation on human Polλ, and establish that its phosphorylation may facilitate the repair of a subset of IR-induced DSBs and the efficient Polλ-mediated gap-filling during NHEJ. Molecular evidence suggests that Polλ phosphorylation might favor Polλ interaction with the DNA-PK complex at DSBs. Altogether, our work provides the first demonstration of how Polλ is regulated by phosphorylation to connect with the NHEJ core machinery during DSB repair in human cells.
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Affiliation(s)
- Guillermo Sastre-Moreno
- Centro de Biología Molecular "Severo Ochoa", Universidad Autónoma de Madrid/CSIC, Madrid 28049, Spain
| | - John M Pryor
- Department of Biochemistry and Biophysics and Curriculum in Genetics and Molecular Biology, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Marta Moreno-Oñate
- Departamento Bioquímica Vegetal y Biología Molecular, Universidad de Sevilla, Sevilla 41092, Spain; Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Universidad de Sevilla/CSIC, Sevilla 41092, Spain
| | - Andrés M Herrero-Ruiz
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Universidad de Sevilla/CSIC, Sevilla 41092, Spain
| | - Felipe Cortés-Ledesma
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Universidad de Sevilla/CSIC, Sevilla 41092, Spain
| | - Luis Blanco
- Centro de Biología Molecular "Severo Ochoa", Universidad Autónoma de Madrid/CSIC, Madrid 28049, Spain
| | - Dale A Ramsden
- Department of Biochemistry and Biophysics and Curriculum in Genetics and Molecular Biology, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Jose F Ruiz
- Departamento Bioquímica Vegetal y Biología Molecular, Universidad de Sevilla, Sevilla 41092, Spain; Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Universidad de Sevilla/CSIC, Sevilla 41092, Spain.
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41
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Vendetti FP, Lau A, Schamus S, Conrads TP, O'Connor MJ, Bakkenist CJ. The orally active and bioavailable ATR kinase inhibitor AZD6738 potentiates the anti-tumor effects of cisplatin to resolve ATM-deficient non-small cell lung cancer in vivo. Oncotarget 2016; 6:44289-305. [PMID: 26517239 PMCID: PMC4792557 DOI: 10.18632/oncotarget.6247] [Citation(s) in RCA: 174] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 10/14/2015] [Indexed: 12/19/2022] Open
Abstract
ATR and ATM are DNA damage signaling kinases that phosphorylate several thousand substrates. ATR kinase activity is increased at damaged replication forks and resected DNA double-strand breaks (DSBs). ATM kinase activity is increased at DSBs. ATM has been widely studied since ataxia telangiectasia individuals who express no ATM protein are the most radiosensitive patients identified. Since ATM is not an essential protein, it is widely believed that ATM kinase inhibitors will be well-tolerated in the clinic. ATR has been widely studied, but advances have been complicated by the finding that ATR is an essential protein and it is widely believed that ATR kinase inhibitors will be toxic in the clinic. We describe AZD6738, an orally active and bioavailable ATR kinase inhibitor. AZD6738 induces cell death and senescence in non-small cell lung cancer (NSCLC) cell lines. AZD6738 potentiates the cytotoxicity of cisplatin and gemcitabine in NSCLC cell lines with intact ATM kinase signaling, and potently synergizes with cisplatin in ATM-deficient NSCLC cells. In contrast to expectations, daily administration of AZD6738 and ATR kinase inhibition for 14 consecutive days is tolerated in mice and enhances the therapeutic efficacy of cisplatin in xenograft models. Remarkably, the combination of cisplatin and AZD6738 resolves ATM-deficient lung cancer xenografts.
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Affiliation(s)
- Frank P Vendetti
- Department of Radiation Oncology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Alan Lau
- Cancer Bioscience, AstraZeneca, Macclesfield, United Kingdom
| | - Sandra Schamus
- Department of Radiation Oncology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Thomas P Conrads
- Women's Health Integrated Research Center at Inova Health System, Department of Defense Gynecologic Cancer Center of Excellence, Annandale, VA, USA
| | - Mark J O'Connor
- Cancer Bioscience, AstraZeneca, Macclesfield, United Kingdom
| | - Christopher J Bakkenist
- Department of Radiation Oncology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.,Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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42
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Kim HJ, Min A, Im SA, Jang H, Lee KH, Lau A, Lee M, Kim S, Yang Y, Kim J, Kim TY, Oh DY, Brown J, O'Connor MJ, Bang YJ. Anti-tumor activity of the ATR inhibitor AZD6738 in HER2 positive breast cancer cells. Int J Cancer 2016; 140:109-119. [DOI: 10.1002/ijc.30373] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Revised: 05/16/2016] [Accepted: 06/30/2016] [Indexed: 01/03/2023]
Affiliation(s)
- Hee-Jun Kim
- Department of Internal Medicine; Chung-Ang University College of Medicine; Seoul Korea
- Translational Medicine; Seoul National University College of Medicine; Seoul Korea
| | - Ahrum Min
- Cancer Research Institute, Seoul National University; Seoul Korea
- Biomedical Research Institute, Seoul National University Hospital; Seoul Korea
| | - Seock-Ah Im
- Translational Medicine; Seoul National University College of Medicine; Seoul Korea
- Cancer Research Institute, Seoul National University; Seoul Korea
- Biomedical Research Institute, Seoul National University Hospital; Seoul Korea
- Department of Internal Medicine; Seoul National University College of Medicine; Seoul Korea
| | - Hyemin Jang
- Cancer Research Institute, Seoul National University; Seoul Korea
| | - Kyung Hun Lee
- Cancer Research Institute, Seoul National University; Seoul Korea
- Biomedical Research Institute, Seoul National University Hospital; Seoul Korea
- Department of Internal Medicine; Seoul National University College of Medicine; Seoul Korea
| | - Alan Lau
- AstraZeneca UK Ltd; Macclesfield, Cheshire United Kingdom
| | - Miso Lee
- Cancer Research Institute, Seoul National University; Seoul Korea
| | - Seongyeong Kim
- Cancer Research Institute, Seoul National University; Seoul Korea
| | - Yaewon Yang
- Translational Medicine; Seoul National University College of Medicine; Seoul Korea
- Cancer Research Institute, Seoul National University; Seoul Korea
- Department of Internal Medicine; Seoul National University College of Medicine; Seoul Korea
| | - Jungeun Kim
- Cancer Research Institute, Seoul National University; Seoul Korea
| | - Tae Yong Kim
- Translational Medicine; Seoul National University College of Medicine; Seoul Korea
- Cancer Research Institute, Seoul National University; Seoul Korea
- Biomedical Research Institute, Seoul National University Hospital; Seoul Korea
- Department of Internal Medicine; Seoul National University College of Medicine; Seoul Korea
| | - Do-Youn Oh
- Translational Medicine; Seoul National University College of Medicine; Seoul Korea
- Cancer Research Institute, Seoul National University; Seoul Korea
- Biomedical Research Institute, Seoul National University Hospital; Seoul Korea
- Department of Internal Medicine; Seoul National University College of Medicine; Seoul Korea
| | | | | | - Yung-Jue Bang
- Translational Medicine; Seoul National University College of Medicine; Seoul Korea
- Cancer Research Institute, Seoul National University; Seoul Korea
- Biomedical Research Institute, Seoul National University Hospital; Seoul Korea
- Department of Internal Medicine; Seoul National University College of Medicine; Seoul Korea
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43
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Xu X, Wang JT, Li M, Liu Y. TIMELESS Suppresses the Accumulation of Aberrant CDC45·MCM2-7·GINS Replicative Helicase Complexes on Human Chromatin. J Biol Chem 2016; 291:22544-22558. [PMID: 27587400 PMCID: PMC5077192 DOI: 10.1074/jbc.m116.719963] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 08/31/2016] [Indexed: 07/24/2023] Open
Abstract
The replication licensing factor CDC6 recruits the MCM2-7 replicative helicase to the replication origin, where MCM2-7 is activated to initiate DNA replication. MCM2-7 is activated by both the CDC7-Dbf4 kinase and cyclin-dependent kinase and via interactions with CDC45 and go-ichi-ni-san complex (GINS) to form the CDC45·MCM2-7·GINS (CMG) helicase complex. TIMELESS (TIM) is important for the subsequent coupling of CMG activity to DNA polymerases for efficient DNA synthesis. However, the mechanism by which TIM regulates CMG activity for proper replication fork progression remains unclear. Here we show that TIM interacts with MCM2-7 prior to the initiation of DNA replication. TIM depletion in various human cell lines results in the accumulation of aberrant CMG helicase complexes on chromatin. Importantly, the presence of these abnormal CMG helicase complexes is not restricted to cells undergoing DNA synthesis. Furthermore, even though these aberrant CMG complexes interact with the DNA polymerases on human chromatin, these complexes are not phosphorylated properly by cyclin-dependent kinase/CDC7-Dbf4 kinase and exhibit reduced DNA unwinding activity. This phenomenon coincides with a significant accumulation of the p27 and p21 replication inhibitors, reduced chromatin association of CDC6 and cyclin E, and a delay in S phase entry. Our results provide the first evidence that TIM is required for the correct chromatin association of the CMG complex to allow efficient DNA replication.
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Affiliation(s)
- Xiaohua Xu
- From the Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, California 91010-3000
| | - Jiin-Tarng Wang
- From the Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, California 91010-3000
| | - Min Li
- From the Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, California 91010-3000
| | - Yilun Liu
- From the Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, California 91010-3000
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44
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Sallmyr A, Matsumoto Y, Roginskaya V, Van Houten B, Tomkinson AE. Inhibiting Mitochondrial DNA Ligase IIIα Activates Caspase 1-Dependent Apoptosis in Cancer Cells. Cancer Res 2016; 76:5431-41. [PMID: 27503931 PMCID: PMC5036517 DOI: 10.1158/0008-5472.can-15-3243] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 06/30/2016] [Indexed: 01/09/2023]
Abstract
Elevated levels of DNA ligase IIIα (LigIIIα) have been identified as a biomarker of an alteration in DNA repair in cancer cells that confers hypersensitivity to a LigIIIα inhibitor, L67, in combination with a poly (ADP-ribose) polymerase inhibitor. Because LigIIIα functions in the nucleus and mitochondria, we examined the effect of L67 on these organelles. Here, we show that, although the DNA ligase inhibitor selectively targets mitochondria, cancer and nonmalignant cells respond differently to disruption of mitochondrial DNA metabolism. Inhibition of mitochondrial LigIIIα in cancer cells resulted in abnormal mitochondrial morphology, reduced levels of mitochondrial DNA, and increased levels of mitochondrially generated reactive oxygen species that caused nuclear DNA damage. In contrast, these effects did not occur in nonmalignant cells. Furthermore, inhibition of mitochondrial LigIIIα activated a caspase 1-dependent apoptotic pathway, which is known to be part of inflammatory responses induced by pathogenic microorganisms in cancer, but not nonmalignant cells. These results demonstrate that the disruption of mitochondrial DNA metabolism elicits different responses in nonmalignant and cancer cells and suggests that the abnormal response in cancer cells may be exploited in the development of novel therapeutic strategies that selectively target cancer cells. Cancer Res; 76(18); 5431-41. ©2016 AACR.
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Affiliation(s)
- Annahita Sallmyr
- Departments of Internal Medicine and Molecular Genetics and Microbiology, and University of New Mexico Cancer Center, University of New Mexico, Albuquerque, New Mexico
| | - Yoshihiro Matsumoto
- Departments of Internal Medicine and Molecular Genetics and Microbiology, and University of New Mexico Cancer Center, University of New Mexico, Albuquerque, New Mexico
| | - Vera Roginskaya
- Department of Pharmacology and Cell Biology, University of Pittsburgh School of Medicine and The University of Pittsburgh Cancer Institute, Hillman Cancer Center, Pittsburgh, Pennsylvania
| | - Bennett Van Houten
- Department of Pharmacology and Cell Biology, University of Pittsburgh School of Medicine and The University of Pittsburgh Cancer Institute, Hillman Cancer Center, Pittsburgh, Pennsylvania
| | - Alan E Tomkinson
- Departments of Internal Medicine and Molecular Genetics and Microbiology, and University of New Mexico Cancer Center, University of New Mexico, Albuquerque, New Mexico.
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45
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Moiseeva TN, Gamper AM, Hood BL, Conrads TP, Bakkenist CJ. Human DNA polymerase ε is phosphorylated at serine-1940 after DNA damage and interacts with the iron-sulfur complex chaperones CIAO1 and MMS19. DNA Repair (Amst) 2016; 43:9-17. [PMID: 27235625 DOI: 10.1016/j.dnarep.2016.04.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 04/12/2016] [Accepted: 04/19/2016] [Indexed: 12/14/2022]
Abstract
We describe a dynamic phosphorylation on serine-1940 of the catalytic subunit of human Pol ε, POLE1, following DNA damage. We also describe novel interactions between POLE1 and the iron-sulfur cluster assembly complex CIA proteins CIAO1 and MMS19. We show that serine-1940 is essential for the interaction between POLE1 and MMS19, but not POLE1 and CIAO1. No defect in either proliferation or survival was identified when POLE1 serine-1940 was mutated to alanine in human cells, even following treatment with DNA damaging agents. We conclude that serine-1940 phosphorylation and the interaction between serine-1940 and MMS19 are not essential functions in the C terminal domain of the catalytic subunit of DNA polymerase ε.
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Affiliation(s)
- Tatiana N Moiseeva
- Department of Radiation Oncology, University of Pittsburgh School of Medicine, Hillman Cancer Center, Research Pavilion, Suite 2.6, 5117 Centre Avenue, Pittsburgh, PA 15213-1863, USA
| | - Armin M Gamper
- Department of Radiation Oncology, University of Pittsburgh School of Medicine, Hillman Cancer Center, Research Pavilion, Suite 2.6, 5117 Centre Avenue, Pittsburgh, PA 15213-1863, USA; Department of Oncology, University of Alberta, Cross Cancer Institute, 11560 University Avenue, Edmonton, AB T6 G 1Z2, Canada
| | - Brian L Hood
- Women's Health Integrated Research Center at Inova Health System, Department of Defense Gynecologic Cancer Center of Excellence, Annandale, VA 22003, USA
| | - Thomas P Conrads
- Women's Health Integrated Research Center at Inova Health System, Department of Defense Gynecologic Cancer Center of Excellence, Annandale, VA 22003, USA
| | - Christopher J Bakkenist
- Department of Radiation Oncology, University of Pittsburgh School of Medicine, Hillman Cancer Center, Research Pavilion, Suite 2.6, 5117 Centre Avenue, Pittsburgh, PA 15213-1863, USA; Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Hillman Cancer Center, Research Pavilion, Suite 2.6, 5117 Centre Avenue, Pittsburgh, PA 15213-1863, USA.
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46
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Chatterjee N, Lin Y, Wilson JH. Mismatch repair enhances convergent transcription-induced cell death at trinucleotide repeats by activating ATR. DNA Repair (Amst) 2016; 42:26-32. [PMID: 27131875 DOI: 10.1016/j.dnarep.2016.03.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 03/15/2016] [Accepted: 03/16/2016] [Indexed: 01/08/2023]
Abstract
Trinucleotide repeat (TNR) expansion beyond a certain threshold results in some 20 incurable neurodegenerative disorders where disease anticipation positively correlates with repeat length. Long TNRs typically display a bias toward further expansion during germinal transmission from parents to offspring, and then are highly unstable in somatic tissues of affected individuals. Understanding mechanisms of TNR instability will provide insights into disease pathogenesis. Previously, we showed that enhanced convergent transcription at long CAG repeat tracks induces TNR instability and cell death via ATR activation. Components of TC-NER (transcription-coupled nucleotide excision repair) and RNaseH enzymes that resolve RNA/DNA hybrids oppose cell death, whereas the MSH2 component of MMR (mismatch repair) enhances cell death. The exact role of the MMR pathway during convergent transcription-induced cell death at CAG repeats is not well understood. In this study, we show that siRNA knockdowns of MMR components-MSH2, MSH3, MLHI, PMS2, and PCNA-reduce DNA toxicity. Furthermore, knockdown of MSH2, MLH1, and PMS2 significantly reduces the frequency of ATR foci formation. These observations suggest that MMR proteins activate DNA toxicity by modulating ATR foci formation during convergent transcription.
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Affiliation(s)
- Nimrat Chatterjee
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
| | - Yunfu Lin
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Smithville, TX 78957, USA
| | - John H Wilson
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
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47
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Beyaert M, Starczewska E, Van Den Neste E, Bontemps F. A crucial role for ATR in the regulation of deoxycytidine kinase activity. Biochem Pharmacol 2016; 100:40-50. [DOI: 10.1016/j.bcp.2015.11.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 11/20/2015] [Indexed: 11/15/2022]
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48
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Wieringa HW, van der Zee AGJ, de Vries EGE, van Vugt MATM. Breaking the DNA damage response to improve cervical cancer treatment. Cancer Treat Rev 2015; 42:30-40. [PMID: 26643553 DOI: 10.1016/j.ctrv.2015.11.008] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 11/16/2015] [Accepted: 11/17/2015] [Indexed: 12/25/2022]
Abstract
Every year, cervical cancer affects ∼500,000 women worldwide, and ∼275,000 patients die of this disease. The addition of platin-based chemotherapy to primary radiotherapy has increased 5-year survival of advanced-stage cervical cancer patients, which is, however, still only 66%. One of the factors thought to contribute to treatment failure is the ability of tumor cells to repair chemoradiotherapy-induced DNA damage. Therefore, sensitization of tumor cells for chemoradiotherapy via inhibition of the DNA damage response (DDR) as a novel strategy to improve therapy effect, is currently studied pre-clinically as well as in the clinic. Almost invariably, cervical carcinogenesis involves infection with the human papillomavirus (HPV), which inactivates part of the DNA damage response. This HPV-mediated partial inactivation of the DDR presents therapeutic targeting of the residual DDR as an interesting approach to achieve chemoradio-sensitization for cervical cancer. How the DDR can be most efficiently targeted, however, remains unclear. The fact that cisplatin and radiotherapy activate multiple signaling axes within the DDR further complicates a rational choice of therapeutic targets within the DDR. In this review, we provide an overview of the current preclinical and clinical knowledge about targeting the DDR in cervical cancer.
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Affiliation(s)
- Hylke W Wieringa
- Department of Medical Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Department of Gynecologic Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Ate G J van der Zee
- Department of Gynecologic Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Elisabeth G E de Vries
- Department of Medical Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Marcel A T M van Vugt
- Department of Medical Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
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49
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Abstract
ATM and ATR signaling pathways are well conserved throughout evolution and are central to the maintenance of genome integrity. Although the role of both ATM and ATR in DNA repair, cell cycle regulation and apoptosis have been well studied, both still remain in the focus of current research activities owing to their role in cancer. Recent advances in the field suggest that these proteins have an additional function in maintaining cellular homeostasis under both stressed and non-stressed conditions. In this Cell Science at a Glance article and the accompanying poster, we present an overview of recent advances in ATR and ATM research with emphasis on that into the modes of ATM and ATR activation, the different signaling pathways they participate in - including those that do not involve DNA damage - and highlight their relevance in cancer.
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Affiliation(s)
- Poorwa Awasthi
- Developmental Toxicology Laboratory, Systems Toxicology and Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research, M.G. Marg 80, Lucknow 226001, India Academy of Scientific and Innovative Research (AcSIR), CSIR-IITR campus, Lucknow 226001, India
| | - Marco Foiani
- IFOM (Fondazione Istituto FIRC di Oncologia Molecolare), IFOM-IEO Campus Via Adamello 16, Milan 20139, Italy DSBB-Università degli Studi di Milano, Milan 20133, Italy
| | - Amit Kumar
- Developmental Toxicology Laboratory, Systems Toxicology and Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research, M.G. Marg 80, Lucknow 226001, India Academy of Scientific and Innovative Research (AcSIR), CSIR-IITR campus, Lucknow 226001, India
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50
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Bakkenist CJ, Kastan MB. Chromatin perturbations during the DNA damage response in higher eukaryotes. DNA Repair (Amst) 2015; 36:8-12. [PMID: 26391293 DOI: 10.1016/j.dnarep.2015.09.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The DNA damage response is a widely used term that encompasses all signaling initiated at DNA lesions and damaged replication forks as it extends to orchestrate DNA repair, cell cycle checkpoints, cell death and senescence. ATM, an apical DNA damage signaling kinase, is virtually instantaneously activated following the introduction of DNA double-strand breaks (DSBs). The MRE11-RAD50-NBS1 (MRN) complex, which has a catalytic role in DNA repair, and the KAT5 (Tip60) acetyltransferase are required for maximal ATM kinase activation in cells exposed to low doses of ionizing radiation. The sensing of DNA lesions occurs within a highly complex and heterogeneous chromatin environment. Chromatin decondensation and histone eviction at DSBs may be permissive for KAT5 binding to H3K9me3 and H3K36me3, ATM kinase acetylation and activation. Furthermore, chromatin perturbation may be a prerequisite for most DNA repair. Nucleosome disassembly during DNA repair was first reported in the 1970s by Smerdon and colleagues when nucleosome rearrangement was noted during the process of nucleotide excision repair of UV-induced DNA damage in human cells. Recently, the multi-functional protein nucleolin was identified as the relevant histone chaperone required for partial nucleosome disruption at DBSs, the recruitment of repair enzymes and for DNA repair. Notably, ATM kinase is activated by chromatin perturbations induced by a variety of treatments that do not directly cause DSBs, including treatment with histone deacetylase inhibitors. Central to the mechanisms that activate ATR, the second apical DNA damage signaling kinase, outside of a stalled and collapsed replication fork in S-phase, is chromatin decondensation and histone eviction associated with DNA end resection at DSBs. Thus, a stress that is common to both ATM and ATR kinase activation is chromatin perturbations, and we argue that chromatin perturbations are both sufficient and required for induction of the DNA damage response.
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Affiliation(s)
- Christopher J Bakkenist
- Departments of Radiation Oncology and Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Hillman Cancer Center, Research Pavilion, Suite 2.6, 5117Centre Avenue, Pittsburgh, PA 15213-1863, USA.
| | - Michael B Kastan
- Executive Director, Duke Cancer Institute, William W. Shingleton Professor of Pharmacology and Cancer Biology, Duke University School of Medicine, 422 Seeley Mudd Building, Box 3917, Durham, NC 27 710, USA.
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