1
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Mattoo AR, Jessup JM. MCL‐1 interacts with MOF and BID to regulate H4K16 acetylation and homologous recombination repair. Cell Biol Int 2022; 46:1196-1203. [DOI: 10.1002/cbin.11831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 02/05/2022] [Accepted: 02/15/2022] [Indexed: 11/06/2022]
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2
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Widden H, Placzek WJ. The multiple mechanisms of MCL1 in the regulation of cell fate. Commun Biol 2021; 4:1029. [PMID: 34475520 PMCID: PMC8413315 DOI: 10.1038/s42003-021-02564-6] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 08/16/2021] [Indexed: 01/11/2023] Open
Abstract
MCL1 (myeloid cell leukemia-1) is a widely recognized pro-survival member of the Bcl-2 (B-cell lymphoma protein 2) family and a promising target for cancer therapy. While the role MCL1 plays in apoptosis is well defined, its participation in emerging non-apoptotic signaling pathways is only beginning to be appreciated. Here, we synthesize studies characterizing MCL1s influence on cell proliferation, DNA damage response, autophagy, calcium handling, and mitochondrial quality control to highlight the broader scope that MCL1 plays in cellular homeostasis regulation. Throughout this review, we discuss which pathways are likely to be impacted by emerging MCL1 inhibitors, as well as highlight non-cancerous disease states that could deploy Bcl-2 homology 3 (BH3)-mimetics in the future. In this review Widden and Placzek synthesize studies characterizing the influence that myeloid cell leukemia-1 (MCL1) has on cell proliferation, DNA damage response, autophagy, calcium handling, and mitochondrial quality control to highlight the broader scope that it plays in cellular homeostasis regulation. They discuss which pathways are likely to be impacted by emerging MCL1 inhibitors, as well as highlight non-cancerous disease states that could deploy BH3-mimetics in the future.
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Affiliation(s)
- Hayley Widden
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - William J Placzek
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, USA.
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3
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Banday S, Pandita RK, Mushtaq A, Bacolla A, Mir US, Singh DK, Jan S, Bhat KP, Hunt CR, Rao G, Charaka VK, Tainer JA, Pandita TK, Altaf M. Autism-Associated Vigilin Depletion Impairs DNA Damage Repair. Mol Cell Biol 2021; 41:e0008221. [PMID: 33941620 PMCID: PMC8224237 DOI: 10.1128/mcb.00082-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 03/17/2021] [Accepted: 04/28/2021] [Indexed: 12/24/2022] Open
Abstract
Vigilin (Vgl1) is essential for heterochromatin formation, chromosome segregation, and mRNA stability and is associated with autism spectrum disorders and cancer: vigilin, for example, can suppress proto-oncogene c-fms expression in breast cancer. Conserved from yeast to humans, vigilin is an RNA-binding protein with 14 tandemly arranged nonidentical hnRNP K-type homology (KH) domains. Here, we report that vigilin depletion increased cell sensitivity to cisplatin- or ionizing radiation (IR)-induced cell death and genomic instability due to defective DNA repair. Vigilin depletion delayed dephosphorylation of IR-induced γ-H2AX and elevated levels of residual 53BP1 and RIF1 foci, while reducing Rad51 and BRCA1 focus formation, DNA end resection, and double-strand break (DSB) repair. We show that vigilin interacts with the DNA damage response (DDR) proteins RAD51 and BRCA1, and vigilin depletion impairs their recruitment to DSB sites. Transient hydroxyurea (HU)-induced replicative stress in vigilin-depleted cells increased replication fork stalling and blocked restart of DNA synthesis. Furthermore, histone acetylation promoted vigilin recruitment to DSBs preferentially in the transcriptionally active genome. These findings uncover a novel vigilin role in DNA damage repair with implications for autism and cancer-related disorders.
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Affiliation(s)
- Shahid Banday
- Chromatin and Epigenetics Lab, Department of Biotechnology, University of Kashmir, Srinagar, Jammu and Kashmir, India
| | - Raj K. Pandita
- Houston Methodist Research Institute, Houston, Texas, USA
- Baylor College of Medicine, Houston, Texas, USA
| | - Arjamand Mushtaq
- Chromatin and Epigenetics Lab, Department of Biotechnology, University of Kashmir, Srinagar, Jammu and Kashmir, India
| | - Albino Bacolla
- Department of Molecular and Cellular Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA
| | - Ulfat Syed Mir
- Chromatin and Epigenetics Lab, Department of Biotechnology, University of Kashmir, Srinagar, Jammu and Kashmir, India
| | | | - Sadaf Jan
- Chromatin and Epigenetics Lab, Department of Biotechnology, University of Kashmir, Srinagar, Jammu and Kashmir, India
| | - Krishna P. Bhat
- Department of Pathology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA
| | | | - Ganesh Rao
- Baylor College of Medicine, Houston, Texas, USA
| | | | - John A. Tainer
- Department of Molecular and Cellular Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA
- Department of Cancer Biology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA
| | - Tej K. Pandita
- Houston Methodist Research Institute, Houston, Texas, USA
- Baylor College of Medicine, Houston, Texas, USA
| | - Mohammad Altaf
- Chromatin and Epigenetics Lab, Department of Biotechnology, University of Kashmir, Srinagar, Jammu and Kashmir, India
- Centre for Interdisciplinary Research and Innovations, University of Kashmir, Srinagar, Jammu and Kashmir, India
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4
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Xie M, Park D, Sica GL, Deng X. Bcl2-induced DNA replication stress promotes lung carcinogenesis in response to space radiation. Carcinogenesis 2021; 41:1565-1575. [PMID: 32157295 DOI: 10.1093/carcin/bgaa021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 02/18/2020] [Accepted: 03/05/2020] [Indexed: 11/12/2022] Open
Abstract
Space radiation is characterized by high-linear energy transfer (LET) ionizing radiation. The relationships between the early biological effects of space radiation and the probability of cancer in humans are poorly understood. Bcl2 not only functions as a potent antiapoptotic molecule but also as an oncogenic protein that induces DNA replication stress. To test the role and mechanism of Bcl2 in high-LET space radiation-induced lung carcinogenesis, we created lung-targeting Bcl2 transgenic C57BL/6 mice using the CC10 promoter to drive Bcl2 expression selectively in lung tissues. Intriguingly, lung-targeting transgenic Bcl2 inhibits ribonucleotide reductase activity, reduces dNTP pool size and retards DNA replication fork progression in mouse bronchial epithelial cells. After exposure of mice to space radiation derived from 56iron, 28silicon or protons, the incidence of lung cancer was significantly higher in lung-targeting Bcl2 transgenic mice than in wild-type mice, indicating that Bcl2-induced DNA replication stress promotes lung carcinogenesis in response to space radiation. The findings provide some evidence for the relative effectiveness of space radiation and Bcl-2 at inducing lung cancer in mice.
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Affiliation(s)
- Maohua Xie
- Department of Radiation Oncology, Emory University School of Medicine and Winship Cancer Institute of Emory University, Atlanta, GA, USA
| | - Dongkyoo Park
- Department of Radiation Oncology, Emory University School of Medicine and Winship Cancer Institute of Emory University, Atlanta, GA, USA
| | - Gabriel L Sica
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine and Winship Cancer Institute of Emory University, Atlanta, GA, USA
| | - Xingming Deng
- Department of Radiation Oncology, Emory University School of Medicine and Winship Cancer Institute of Emory University, Atlanta, GA, USA
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5
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Qiu S, Huang J. MRN complex is an essential effector of DNA damage repair. J Zhejiang Univ Sci B 2021; 22:31-37. [PMID: 33448185 PMCID: PMC7818010 DOI: 10.1631/jzus.b2000289] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 08/16/2020] [Indexed: 01/01/2023]
Abstract
Genome stability can be threatened by both endogenous and exogenous agents. Organisms have evolved numerous mechanisms to repair DNA damage, including homologous recombination (HR) and non-homologous end joining (NHEJ). Among the factors associated with DNA repair, the MRE11-RAD50-NBS1 (MRN) complex (MRE11-RAD50-XRS2 in Saccharomyces cerevisiae) plays important roles not only in DNA damage recognition and signaling but also in subsequent HR or NHEJ repair. Upon detecting DNA damage, the MRN complex activates signaling molecules, such as the protein kinase ataxia-telangiectasia mutated (ATM), to trigger a broad DNA damage response, including cell cycle arrest. The nuclease activity of the MRN complex is responsible for DNA end resection, which guides DNA repair to HR in the presence of sister chromatids. The MRN complex is also involved in NHEJ, and has a species-specific role in hairpin repair. This review focuses on the structure of the MRN complex and its function in DNA damage repair.
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Affiliation(s)
- Shan Qiu
- The MOE Key Laboratory of Biosystems Homeostasis & Protection, Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
- Zhejiang University-University of Edinburgh Institute, School of Medicine, Zhejiang University, Haining 314400, China
| | - Jun Huang
- The MOE Key Laboratory of Biosystems Homeostasis & Protection, Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China.
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6
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Falk M, Hausmann M. A Paradigm Revolution or Just Better Resolution-Will Newly Emerging Superresolution Techniques Identify Chromatin Architecture as a Key Factor in Radiation-Induced DNA Damage and Repair Regulation? Cancers (Basel) 2020; 13:E18. [PMID: 33374540 PMCID: PMC7793109 DOI: 10.3390/cancers13010018] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 12/18/2020] [Indexed: 02/07/2023] Open
Abstract
DNA double-strand breaks (DSBs) have been recognized as the most serious lesions in irradiated cells. While several biochemical pathways capable of repairing these lesions have been identified, the mechanisms by which cells select a specific pathway for activation at a given DSB site remain poorly understood. Our knowledge of DSB induction and repair has increased dramatically since the discovery of ionizing radiation-induced foci (IRIFs), initiating the possibility of spatiotemporally monitoring the assembly and disassembly of repair complexes in single cells. IRIF exploration revealed that all post-irradiation processes-DSB formation, repair and misrepair-are strongly dependent on the characteristics of DSB damage and the microarchitecture of the whole affected chromatin domain in addition to the cell status. The microscale features of IRIFs, such as their morphology, mobility, spatiotemporal distribution, and persistence kinetics, have been linked to repair mechanisms. However, the influence of various biochemical and structural factors and their specific combinations on IRIF architecture remains unknown, as does the hierarchy of these factors in the decision-making process for a particular repair mechanism at each individual DSB site. New insights into the relationship between the physical properties of the incident radiation, chromatin architecture, IRIF architecture, and DSB repair mechanisms and repair efficiency are expected from recent developments in optical superresolution microscopy (nanoscopy) techniques that have shifted our ability to analyze chromatin and IRIF architectures towards the nanoscale. In the present review, we discuss this relationship, attempt to correlate still rather isolated nanoscale studies with already better-understood aspects of DSB repair at the microscale, and consider whether newly emerging "correlated multiscale structuromics" can revolutionarily enhance our knowledge in this field.
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Affiliation(s)
- Martin Falk
- Institute of Biophysics, The Czech Academy of Sciences, 612 65 Brno, Czech Republic
| | - Michael Hausmann
- Kirchhoff Institute for Physics, Heidelberg University, 69120 Heidelberg, Germany;
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Heisey DAR, Lochmann TL, Floros KV, Coon CM, Powell KM, Jacob S, Calbert ML, Ghotra MS, Stein GT, Maves YK, Smith SC, Benes CH, Leverson JD, Souers AJ, Boikos SA, Faber AC. The Ewing Family of Tumors Relies on BCL-2 and BCL-X L to Escape PARP Inhibitor Toxicity. Clin Cancer Res 2018; 25:1664-1675. [PMID: 30348635 DOI: 10.1158/1078-0432.ccr-18-0277] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 07/11/2018] [Accepted: 10/17/2018] [Indexed: 11/16/2022]
Abstract
PURPOSE It was recently demonstrated that the EWSR1-FLI1 t(11;22)(q24;12) translocation contributes to the hypersensitivity of Ewing sarcoma to PARP inhibitors, prompting clinical evaluation of olaparib in a cohort of heavily pretreated Ewing sarcoma tumors. Unfortunately, olaparib activity was disappointing, suggesting an underappreciated resistance mechanism to PARP inhibition in patients with Ewing sarcoma. We sought to elucidate the resistance factors to PARP inhibitor therapy in Ewing sarcoma and identify a rational drug combination capable of rescuing PARP inhibitor activity. EXPERIMENTAL DESIGN We employed a pair of cell lines derived from the same patient with Ewing sarcoma prior to and following chemotherapy, a panel of Ewing sarcoma cell lines, and several patient-derived xenograft (PDX) and cell line xenograft models. RESULTS We found olaparib sensitivity was diminished following chemotherapy. The matched cell line pair revealed increased expression of the antiapoptotic protein BCL-2 in the chemotherapy-resistant cells, conferring apoptotic resistance to olaparib. Resistance to olaparib was maintained in this chemotherapy-resistant model in vivo, whereas the addition of the BCL-2/XL inhibitor navitoclax led to tumor growth inhibition. In 2 PDXs, olaparib and navitoclax were minimally effective as monotherapy, yet induced dramatic tumor growth inhibition when dosed in combination. We found that EWS-FLI1 increases BCL-2 expression; however, inhibition of BCL-2 alone by venetoclax is insufficient to sensitize Ewing sarcoma cells to olaparib, revealing a dual necessity for BCL-2 and BCL-XL in Ewing sarcoma survival. CONCLUSIONS These data reveal BCL-2 and BCL-XL act together to drive olaparib resistance in Ewing sarcoma and reveal a novel, rational combination therapy that may be put forward for clinical trial testing.
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Affiliation(s)
- Daniel A R Heisey
- VCU Philips Institute, School of Dentistry and Massey Cancer Center; Richmond, Virginia
| | - Timothy L Lochmann
- VCU Philips Institute, School of Dentistry and Massey Cancer Center; Richmond, Virginia
| | - Konstantinos V Floros
- VCU Philips Institute, School of Dentistry and Massey Cancer Center; Richmond, Virginia
| | - Colin M Coon
- VCU Philips Institute, School of Dentistry and Massey Cancer Center; Richmond, Virginia
| | - Krista M Powell
- VCU Philips Institute, School of Dentistry and Massey Cancer Center; Richmond, Virginia
| | - Sheeba Jacob
- VCU Philips Institute, School of Dentistry and Massey Cancer Center; Richmond, Virginia
| | - Marissa L Calbert
- VCU Philips Institute, School of Dentistry and Massey Cancer Center; Richmond, Virginia
| | - Maninderjit S Ghotra
- VCU Philips Institute, School of Dentistry and Massey Cancer Center; Richmond, Virginia
| | - Giovanna T Stein
- Massachusetts General Hospital Cancer Center, Boston, Massachusetts; Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | | | - Steven C Smith
- Division of Anatomic Pathology, Virginia Commonwealth University, Richmond, Virginia
| | - Cyril H Benes
- Massachusetts General Hospital Cancer Center, Boston, Massachusetts; Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | | | | | - Sosipatros A Boikos
- Hematology, Oncology and Palliative Care, School of Medicine and Massey Cancer Center, Virginia Commonwealth University, Richmond, Virginia
| | - Anthony C Faber
- VCU Philips Institute, School of Dentistry and Massey Cancer Center; Richmond, Virginia.
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8
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Chen G, Magis AT, Xu K, Park D, Yu DS, Owonikoko TK, Sica GL, Satola SW, Ramalingam SS, Curran WJ, Doetsch PW, Deng X. Targeting Mcl-1 enhances DNA replication stress sensitivity to cancer therapy. J Clin Invest 2017; 128:500-516. [PMID: 29227281 DOI: 10.1172/jci92742] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 11/02/2017] [Indexed: 12/21/2022] Open
Abstract
DNA double-strand breaks (DSBs) are mainly repaired either by homologous recombination (HR) or by nonhomologous end-joining (NHEJ) pathways. Here, we showed that myeloid cell leukemia sequence 1 (Mcl-1) acts as a functional switch in selecting between HR and NHEJ pathways. Mcl-1 was cell cycle-regulated during HR, with its expression peaking in S/G2 phase. While endogenous Mcl-1 depletion reduced HR and enhanced NHEJ, Mcl-1 overexpression resulted in a net increase in HR over NHEJ. Mcl-1 directly interacted with the dimeric Ku protein complex via its Bcl-2 homology 1 and 3 (BH1 and BH3) domains, which are required for Mcl-1 to inhibit Ku-mediated NHEJ. Mcl-1 also promoted DNA resection mediated by the Mre11 complex and HR-dependent DSB repair. Using the Mcl-1 BH1 domain as a docking site, we identified a small molecule, MI-223, that directly bound to BH1 and blocked Mcl-1-stimulated HR DNA repair, leading to sensitization of cancer cells to hydroxyurea- or olaparib-induced DNA replication stress. Combined treatment with MI-223 and hydroxyurea or olaparib exhibited a strong synergy against lung cancer in vivo. This mechanism-driven combination of agents provides a highly attractive therapeutic strategy to improve lung cancer outcomes.
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Affiliation(s)
- Guo Chen
- Department of Radiation Oncology, Emory University School of Medicine and Winship Cancer Institute of Emory University, Atlanta, Georgia, USA
| | | | - Ke Xu
- Department of Radiation Oncology, Emory University School of Medicine and Winship Cancer Institute of Emory University, Atlanta, Georgia, USA
| | - Dongkyoo Park
- Department of Radiation Oncology, Emory University School of Medicine and Winship Cancer Institute of Emory University, Atlanta, Georgia, USA
| | - David S Yu
- Department of Radiation Oncology, Emory University School of Medicine and Winship Cancer Institute of Emory University, Atlanta, Georgia, USA
| | | | | | | | | | - Walter J Curran
- Department of Radiation Oncology, Emory University School of Medicine and Winship Cancer Institute of Emory University, Atlanta, Georgia, USA
| | - Paul W Doetsch
- Department of Radiation Oncology, Emory University School of Medicine and Winship Cancer Institute of Emory University, Atlanta, Georgia, USA.,Department of Biochemistry, Emory University School of Medicine and Winship Cancer Institute of Emory University, Atlanta, Georgia, USA
| | - Xingming Deng
- Department of Radiation Oncology, Emory University School of Medicine and Winship Cancer Institute of Emory University, Atlanta, Georgia, USA
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9
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Gabellini C, Trisciuoglio D, Del Bufalo D. Non-canonical roles of Bcl-2 and Bcl-xL proteins: relevance of BH4 domain. Carcinogenesis 2017; 38:579-587. [PMID: 28203756 DOI: 10.1093/carcin/bgx016] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 02/14/2017] [Indexed: 02/07/2023] Open
Abstract
Bcl-2 protein family is constituted by multidomain members originally identified as modulators of programmed cell death and whose expression is frequently misbalanced in cancer cells. The lead member Bcl-2 and its homologue Bcl-xL proteins are characterized by the presence of all four conserved BH domain and exert their antiapoptotic role mainly through the involvement of BH1, BH2 and BH3 homology domains, that mediate the interaction with the proapoptotic members of the same Bcl-2 family. The N-terminal BH4 domain of Bcl-2 and Bcl-xL is responsible for the interaction with other proteins that do not belong to Bcl-2 protein family. Beyond a classical role in inhibiting apoptosis, BH4 domain has been characterized as a crucial regulator of other important cellular functions attributed to Bcl-2 and Bcl-xL, including proliferation, autophagy, differentiation, DNA repair, cell migration, tumor progression and angiogenesis. During the last two decades a strong effort has been made to dissect the molecular pathways involved the capability of BH4 domain to regulate the canonical antiapoptotic and the non-canonical activities of Bcl-2 and Bcl-xL, creating the basis for the development of novel anticancer agents targeting this domain. Indeed, recent evidences obtained on in vitro and in vivo model of different cancer histotypes are confirming the promising therapeutic potential of BH4 domain inhibitors supporting their future employment as a novel anticancer strategy.
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Affiliation(s)
- Chiara Gabellini
- Unit of Cell and Developmental Biology, Department of Biology, University of Pisa, 56127 Pisa, Italy
| | - Daniela Trisciuoglio
- Institute of Molecular Biology and Pathology, National Research Council, 00185 Rome, Italy and.,Preclinical Models and New Therapeutic Agents Unit, Regina Elena National Cancer Institute, 00144 Rome, Italy
| | - Donatella Del Bufalo
- Preclinical Models and New Therapeutic Agents Unit, Regina Elena National Cancer Institute, 00144 Rome, Italy
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10
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Modi P, Balakrishnan K, Yang Q, Wierda WG, Keating MJ, Gandhi V. Idelalisib and bendamustine combination is synergistic and increases DNA damage response in chronic lymphocytic leukemia cells. Oncotarget 2017; 8:16259-16274. [PMID: 28187444 PMCID: PMC5369961 DOI: 10.18632/oncotarget.15180] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 01/25/2017] [Indexed: 11/25/2022] Open
Abstract
Idelalisib is a targeted agent that potently inhibits PI3Kδ which is exclusively expressed in hematological cells. Bendamustine is a well-tolerated cytotoxic alkylating agent which has been extensively used for treatment of chronic lymphocytic leukemia (CLL). Both these agents are FDA-approved for CLL. To increase the potency of idelalisib and bendamustine, we tested their combination in primary CLL lymphocytes. While each compound alone produced a moderate response, combination at several concentrations resulted in synergistic cytotoxicity. Idelalisib enhanced the bendamustine-mediated DNA damage/repair response, indicated by the phosphorylation of ATM, Chk2, and p53. Each drug alone activated γH2AX but combination treatment further increased the expression of this DNA damage marker. Compared with the control, idelalisib treatment decreased global RNA synthesis, resulting in a decline of early-response and short-lived MCL1 transcripts. In concert, there was a decline in total Mcl-1 protein in CLL lymphocytes. Isogenic mouse embryonic fibroblasts lacking MCL1 had higher sensitivity to bendamustine alone or in combination compared to MCL1 proficient cells. Collectively, these data indicate that bendamustine and idelalisib combination therapy should be investigated for treating patients with CLL.
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Affiliation(s)
- Prexy Modi
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Kumudha Balakrishnan
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Qingshan Yang
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - William G Wierda
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Michael J Keating
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Varsha Gandhi
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.,Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
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11
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MCL-1 Depletion Impairs DNA Double-Strand Break Repair and Reinitiation of Stalled DNA Replication Forks. Mol Cell Biol 2017; 37:MCB.00535-16. [PMID: 27821478 DOI: 10.1128/mcb.00535-16] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 10/24/2016] [Indexed: 12/31/2022] Open
Abstract
Myeloid cell leukemia 1 (MCL-1) is a prosurvival BCL-2 protein family member highly expressed in hematopoietic stem cells (HSCs) and regulated by growth factor signals that manifest antiapoptotic activity. Here we report that depletion of MCL-1 but not its isoform MCL-1S increases genomic instability and cell sensitivity to ionizing radiation (IR)-induced death. MCL-1 association with genomic DNA increased postirradiation, and the protein colocalized with 53BP1 foci. Postirradiation, MCL-1-depleted cells exhibited decreased γ-H2AX foci, decreased phosphorylation of ATR, and higher levels of residual 53BP1 and RIF1 foci, suggesting that DNA double-strand break (DSB) repair by homologous recombination (HR) was compromised. Consistent with this model, MCL-1-depleted cells had a reduced frequency of IR-induced BRCA1, RPA, and Rad51 focus formation, decreased DNA end resection, and decreased HR repair in the DR-GFP DSB repair model. Similarly, after HU induction of stalled replication forks in MCL-1-depleted cells, there was a decreased ability to subsequently restart DNA synthesis, which is normally dependent upon HR-mediated resolution of collapsed forks. Therefore, the present data support a model whereby MCL-1 depletion increases 53BP1 and RIF1 colocalization at DSBs, which inhibits BRCA1 recruitment, and sensitizes cells to DSBs from IR or stalled replication forks that require HR for repair.
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12
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Hypericin in the Dark: Foe or Ally in Photodynamic Therapy? Cancers (Basel) 2016; 8:cancers8100093. [PMID: 27754424 PMCID: PMC5082383 DOI: 10.3390/cancers8100093] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Revised: 09/29/2016] [Accepted: 10/04/2016] [Indexed: 12/12/2022] Open
Abstract
Photosensitizers (PSs) in photodynamic therapy (PDT) are, in most cases, administered systemically with preferential accumulation in malignant tissues; however, exposure of non-malignant tissues to PS may also be clinically relevant, when PS molecules affect the pro-apoptotic cascade without illumination. Hypericin (Hyp) as PS and its derivatives have long been studied, regarding their photodynamic and photocytotoxic characteristics. Hyp and its derivatives have displayed light-activated antiproliferative and cytotoxic effects in many tumor cell lines without cytotoxicity in the dark. However, light-independent effects of Hyp have emerged. Contrary to the acclaimed Hyp minimal dark cytotoxicity and preferential accumulation in tumor cells, it was recently been shown that non-malignant and malignant cells uptake Hyp at a similar level. In addition, Hyp has displayed light-independent toxicity and anti-proliferative effects in a wide range of concentrations. There are multiple mechanisms underlying Hyp light-independent effects, and we are still missing many details about them. In this paper, we focus on Hyp light-independent effects at several sub-cellular levels—protein distribution and synthesis, organelle ultrastructure and function, and Hyp light-independent effects regarding reactive oxygen species (ROS). We summarize work from our laboratories and that of others to reveal an intricate network of the Hyp light-independent effects. We propose a schematic model of pro- and anti-apoptotic protein dynamics between cell organelles due to Hyp presence without illumination. Based on our model, Hyp can be explored as an adjuvant therapeutic drug in combination with chemo- or radiation cancer therapy.
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13
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Wang X, Guda C. Integrative exploration of genomic profiles for triple negative breast cancer identifies potential drug targets. Medicine (Baltimore) 2016; 95:e4321. [PMID: 27472710 PMCID: PMC5265847 DOI: 10.1097/md.0000000000004321] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Triple negative breast cancer (TNBC) is high-risk due to its rapid drug resistance and recurrence, metastasis, and lack of targeted therapy. So far, no molecularly targeted therapeutic agents have been clinically approved for TNBC. It is imperative that we discover new targets for TNBC therapy. OBJECTIVES A large volume of cancer genomics data are emerging and advancing breast cancer research. We may integrate different types of TNBC genomic data to discover molecular targets for TNBC therapy. DATA SOURCES We used publicly available TNBC tumor tissue genomic data in the Cancer Genome Atlas database in this study. METHODS We integratively explored genomic profiles (gene expression, copy number, methylation, microRNA [miRNA], and gene mutation) in TNBC and identified hyperactivated genes that have higher expression, more copy numbers, lower methylation level, or are targets of miRNAs with lower expression in TNBC than in normal samples. We ranked the hyperactivated genes into different levels based on all the genomic evidence and performed functional analyses of the sets of genes identified. More importantly, we proposed potential molecular targets for TNBC therapy based on the hyperactivated genes. RESULTS Some of the genes we identified such as FGFR2, MAPK13, TP53, SRC family, MUC family, and BCL2 family have been suggested to be potential targets for TNBC treatment. Others such as CSF1R, EPHB3, TRIB1, and LAD1 could be promising new targets for TNBC treatment. By utilizing this integrative analysis of genomic profiles for TNBC, we hypothesized that some of the targeted treatment strategies for TNBC currently in development are more likely to be promising, such as poly (ADP-ribose) polymerase inhibitors, while the others are more likely to be discouraging, such as angiogenesis inhibitors. LIMITATIONS The findings in this study need to be experimentally validated in the future. CONCLUSION This is a systematic study that combined 5 different types of genomic data to molecularly characterize TNBC and identify potential targets for TNBC therapy. The integrative analysis of genomic profiles for TNBC could assist in identifying potential new therapeutic targets and predicting the effectiveness of a targeted treatment strategy for TNBC therapy.
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Affiliation(s)
- Xiaosheng Wang
- School of Basic Medicine and Clinic Pharmacy, China Pharmaceutical University, Nanjing, China
- Correspondence: Xiaosheng Wang, China Pharmaceutical University, Nanjing, Jiangsu, China (e-mail: )
| | - Chittibabu Guda
- Department of Genetics, Cell Biology and Anatomy
- Bioinformatics and Systems Biology Core
- Department of Biochemistry and Molecular Biology
- Fred and Pamela Buffet Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska, USA
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Affinity purification-mass spectrometry analysis of bcl-2 interactome identified SLIRP as a novel interacting protein. Cell Death Dis 2016; 7:e2090. [PMID: 26866271 PMCID: PMC4849145 DOI: 10.1038/cddis.2015.357] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 11/04/2015] [Accepted: 11/04/2015] [Indexed: 02/06/2023]
Abstract
Members of the bcl-2 protein family share regions of sequence similarity, the bcl-2 homology (BH) domains. Bcl-2, the most studied member of this family, has four BH domains, BH1–4, and has a critical role in resistance to antineoplastic drugs by regulating the mitochondrial apoptotic pathway. Moreover, it is also involved in other relevant cellular processes such as tumor progression, angiogenesis and autophagy. Deciphering the network of bcl-2-interacting factors should provide a critical advance in understanding the different functions of bcl-2. Here, we characterized bcl-2 interactome by mass spectrometry in human lung adenocarcinoma cells. In silico functional analysis associated most part of the identified proteins to mitochondrial functions. Among them we identified SRA stem–loop interacting RNA-binding protein, SLIRP, a mitochondrial protein with a relevant role in regulating mitochondrial messenger RNA (mRNA) homeostasis. We validated bcl-2/SLIRP interaction by immunoprecipitation and immunofluorescence experiments in cancer cell lines from different histotypes. We showed that, although SLIRP is not involved in mediating bcl-2 ability to protect from apoptosis and oxidative damage, bcl-2 binds and stabilizes SLIRP protein and regulates mitochondrial mRNA levels. Moreover, we demonstrated that the BH4 domain of bcl-2 has a role in maintaining this binding.
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Wang X, Zhang Y, Han ZG, He KY. Malignancy of Cancers and Synthetic Lethal Interactions Associated With Mutations of Cancer Driver Genes. Medicine (Baltimore) 2016; 95:e2697. [PMID: 26937901 PMCID: PMC4778998 DOI: 10.1097/md.0000000000002697] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The mutation status of cancer driver genes may correlate with different degrees of malignancy of cancers. The doubling time and multidrug resistance are 2 phenotypes that reflect the degree of malignancy of cancer cells. Because most of cancer driver genes are hard to target, identification of their synthetic lethal partners might be a viable approach to treatment of the cancers with the relevant mutations.The genome-wide screening for synthetic lethal partners is costly and labor intensive. Thus, a computational approach facilitating identification of candidate genes for a focus synthetic lethal RNAi screening will accelerate novel anticancer drug discovery.We used several publicly available cancer cell lines and tumor tissue genomic data in this study.We compared the doubling time and multidrug resistance between the NCI-60 cell lines with mutations in some cancer driver genes and those without the mutations. We identified some candidate synthetic lethal genes to the cancer driver genes APC, KRAS, BRAF, PIK3CA, and TP53 by comparison of their gene phenotype values in cancer cell lines with the relevant mutations and wild-type background. Further, we experimentally validated some of the synthetic lethal relationships we predicted.We reported that mutations in some cancer driver genes mutations in some cancer driver genes such as APC, KRAS, or PIK3CA might correlate with cancer proliferation or drug resistance. We identified 40, 21, 5, 43, and 18 potential synthetic lethal genes to APC, KRAS, BRAF, PIK3CA, and TP53, respectively. We found that some of the potential synthetic lethal genes show significantly higher expression in the cancers with mutations of their synthetic lethal partners and the wild-type counterparts. Further, our experiments confirmed several synthetic lethal relationships that are novel findings by our methods.We experimentally validated a part of the synthetic lethal relationships we predicted. We plan to perform further experiments to validate the other synthetic lethal relationships predicted by this study.Our computational methods achieve to identify candidate synthetic lethal partners to cancer driver genes for further experimental screening with multiple lines of evidences, and therefore contribute to development of anticancer drugs.
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Affiliation(s)
- Xiaosheng Wang
- From the School of Basic Medicine and Clinic Pharmacy (XW), China Pharmaceutical University, Nanjing; The First Clinical College of Harbin Medical University (YZ), Harbin, China; Division of Genetics and Development (YZ), The Toronto Western Research Institute, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada; and Key Laboratory of Systems Biomedicine (Ministry of Education) (Z-GH, K-YH), Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai, China
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Shrivastava S, Mansure JJ, Almajed W, Cury F, Ferbeyre G, Popovic M, Seuntjens J, Kassouf W. The Role of HMGB1 in Radioresistance of Bladder Cancer. Mol Cancer Ther 2015; 15:471-9. [PMID: 26719575 DOI: 10.1158/1535-7163.mct-15-0581] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 11/15/2015] [Indexed: 11/16/2022]
Abstract
Although radical cystectomy surgery is the standard-of-care for muscle-invasive bladder cancer, it entails complete removal of the bladder and surrounding organs which leads to substantial loss in the quality-of-life of patients. Radiotherapy, which spares the bladder, would be a more appropriate treatment modality if we can utilize molecular markers to select patients with better response to radiation. In this study, we investigate a protein called high mobility group box protein 1 (HMGB1) as a predictive marker for radiotherapy response in bladder cancer. Our in vitro results indicate a positive correlation between higher levels of HMGB1 protein and resistance to radiation in various cell lines. Upon HMGB1 protein knockdown, highly significant (>1.5-fold) sensitization to radiotherapy was achieved. We saw that loss of HMGB1 was associated with at least two times higher (P < 0.001) DNA damage in cell lines postradiation. Our results also depicted that autophagy was inhibited more than 3-fold (P < 0.001) upon HMGB1 knockdown, implicating its role in autophagy as another cause of bladder cancer radioresistance. Further validation was done in vivo by conducting mouse tumor xenograft experiments, where HMGB1 knockdown tumors showed a significantly better (P < 0.001) response to radiotherapy and decreased autophagy (shown by P62 staining) as compared with controls. The cumulative findings of our in vitro and in vivo studies highlight the significance of HMGB1 as a radiation response marker as well as its utility in radiosensitization of bladder cancer.
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Affiliation(s)
- Sanhita Shrivastava
- Urologic Oncology Research Division, McGill University, Montréal, Quebec, Canada
| | - Jose Joao Mansure
- Urologic Oncology Research Division, McGill University, Montréal, Quebec, Canada
| | - Wael Almajed
- Urologic Oncology Research Division, McGill University, Montréal, Quebec, Canada
| | - Fabio Cury
- Department of Radiation Oncology, McGill University Health Center, Montréal, Quebec, Canada
| | - Gerardo Ferbeyre
- Department of Biochemistry, University of Montreal, Montréal, Quebec, Canada
| | - Marija Popovic
- Department of Medical Physics, McGill University Health Center, Montréal, Quebec, Canada
| | - Jan Seuntjens
- Department of Medical Physics, McGill University Health Center, Montréal, Quebec, Canada
| | - Wassim Kassouf
- Urologic Oncology Research Division, McGill University, Montréal, Quebec, Canada.
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Zhang J, Wang S, Wang L, Wang R, Chen S, Pan B, Sun Y, Chen H. Prognostic value of Bcl-2 expression in patients with non-small-cell lung cancer: a meta-analysis and systemic review. Onco Targets Ther 2015; 8:3361-9. [PMID: 26604794 PMCID: PMC4655977 DOI: 10.2147/ott.s89275] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Objective B-cell-lymphoma-2 (Bcl-2) is a proto-oncogene that plays an important role in the regulation of apoptosis and cell survival. However, there are much conflicting data in the literature concerning the association between Bcl-2 and prognosis in non-small-cell lung cancer (NSCLC). There is little in the way of meta-analysis focused on Bcl-2 and its effect on NSCLC prognosis. This study was performed to provide an assessment of whether expression levels of Bcl-2 are associated with prognosis in patients with NSCLC. Materials and methods We searched PubMed, the Cochrane Library, and China National Knowledge Infrastructure for all eligible studies. The combined hazard ratios (HRs) and their corresponding 95% confidence intervals (CIs) in terms of overall survival were evaluated. Results Fifty published studies including 6,863 patients with lung cancer were included in this meta-analysis. Overall, Bcl-2 was expressed in 33% of the NSCLC tumors studied. Our analysis indicates that NSCLC patients with Bcl-2-positive expression have a better prognosis than those with Bcl-2-negative expression in both Asian and non-Asian study populations (HR 0.79, 95% CI 0.72–0.87, P<0.00001). However, Bcl-2-positive expression seems to have no significant impact on survival of stage I NSCLC patients. Conclusion Our results indicated that Bcl-2 might be a useful prognostic marker for NSCLC generally. Larger clinical trials are needed to confirm the prognostic value of Bcl-2 in stage I NSCLC.
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Affiliation(s)
- Jie Zhang
- Department of Thoracic Surgery, Fudan University Shanghai Cancer Center, Shanghai, People's Republic of China ; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China ; Department of Oncology, Longhua Hospital, Shanghai, People's Republic of China
| | - Shengfei Wang
- Department of Thoracic Surgery, Fudan University Shanghai Cancer Center, Shanghai, People's Republic of China ; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China ; Department of Oncology, Longhua Hospital, Shanghai, People's Republic of China
| | - Lei Wang
- Department of Thoracic Surgery, Fudan University Shanghai Cancer Center, Shanghai, People's Republic of China ; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China
| | - Rui Wang
- Department of Thoracic Surgery, Fudan University Shanghai Cancer Center, Shanghai, People's Republic of China ; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China
| | - Sufeng Chen
- Department of Thoracic Surgery, Fudan University Shanghai Cancer Center, Shanghai, People's Republic of China ; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China
| | - Bin Pan
- Department of Thoracic Surgery, Fudan University Shanghai Cancer Center, Shanghai, People's Republic of China ; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China
| | - Yihua Sun
- Department of Thoracic Surgery, Fudan University Shanghai Cancer Center, Shanghai, People's Republic of China ; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China
| | - Haiquan Chen
- Department of Thoracic Surgery, Fudan University Shanghai Cancer Center, Shanghai, People's Republic of China ; Department of Thoracic Surgery, Shanghai Chest Hospital, Jiao Tong University, Shanghai, People's Republic of China
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Liu M, Liu B, Liu B, Cui X, Yang S, Wang Q, Dong L. Mucosa-associated lymphoid tissue lymphoma of the larynx: a case report and literature review. Medicine (Baltimore) 2015; 94:e788. [PMID: 25929928 PMCID: PMC4603055 DOI: 10.1097/md.0000000000000788] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The clinicopathological characteristics and rational treatment of primary laryngeal mucosa-associated lymphoid tissue (MALT) lymphoma are still unclear and need to be further defined due to the paucity of this separate lymphoma.Herein, a supraglottic primary MALT lymphoma was described with detailed clinical course, intervention, and follow-up. To date, research of laryngeal MALT lymphoma has seldom been initiated. Our experience in this case will help to expand our understanding of this unique disease. A 58-year-old female presented with a history of progressive hoarseness for about 10 months. Multiple laryngoscopy examinations revealed severe hypertrophy of left ventricular band. She was admitted to our department with residual MALT lymphoma of supraglottic region after partial resection by laser. After systemic evaluation, she was staged as IEA, International Prognostic Index score 0. Irradiation of intensity modulated radiotherapy technique with a dose of 30.6 Gy/17f to the tumor and 25.5 Gy/17f to the related lymphatic drainage area achieved a complete remission. The disease-free survival has reached to 4 years. The irradiation related acute and late side effects were mild.Radiotherapy is the first option for limited-stage primary laryngeal MALT lymphoma because of excellent treatment outcome.
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Affiliation(s)
- Min Liu
- From the Department of Radiation Oncology (ML, BL, SY, QW, LD); Department of Hand Surgery (BL); and Department of Otolaryngology (XC), The First Hospital, Jilin University, Changchun, China
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