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Marshall S, Navarro MVAS, Ascenҫão CFR, Dibitetto D, Smolka MB. In-Depth Mapping of DNA-PKcs Signaling Uncovers Non-Canonical Features of Its Kinase Specificity. J Biol Chem 2024:107513. [PMID: 38945450 DOI: 10.1016/j.jbc.2024.107513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 06/11/2024] [Accepted: 06/25/2024] [Indexed: 07/02/2024] Open
Abstract
DNA-PKcs is a DNA damage sensor kinase with established roles in DNA double-strand break repair via non-homologous end joining. Recent studies have revealed additional roles of DNA-PKcs in the regulation of transcription, translation, and DNA replication. However, the substrates through which DNA-PKcs regulates these processes remain largely undefined. Here we utilized quantitative phosphoproteomics to generate a high coverage map of DNA-PKcs signaling in response to ionizing radiation and mapped its interplay with the ATM kinase. Beyond the detection of the canonical S/T-Q phosphorylation motif, we uncovered a non-canonical mode of DNA-PKcs signaling targeting S/T-ψ-D/E motifs. Sequence and structural analyses of the DNA-PKcs substrate recognition pocket revealed unique features compared to closely related PIKK kinases that may explain its broader substrate preference. These findings expand the repertoire of DNA-PKcs and ATM substrates while establishing a novel preferential phosphorylation motif for DNA-PKcs.
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Affiliation(s)
- Shannon Marshall
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - Marcos V A S Navarro
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA; IFSC Institute of Physics of São Carlos, University of São Paulo, São Carlos - SP, 13566-590, Brazil.
| | - Carolline F R Ascenҫão
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - Diego Dibitetto
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA; Department of Experimental Oncology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, via Mario Negri 2, 20156 Milan, Italy
| | - Marcus B Smolka
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA.
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Rødland GE, Temelie M, Eek Mariampillai A, Hauge S, Gilbert A, Chevalier F, Savu DI, Syljuåsen RG. Potential Benefits of Combining Proton or Carbon Ion Therapy with DNA Damage Repair Inhibitors. Cells 2024; 13:1058. [PMID: 38920686 PMCID: PMC11201490 DOI: 10.3390/cells13121058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 06/03/2024] [Accepted: 06/05/2024] [Indexed: 06/27/2024] Open
Abstract
The use of charged particle radiotherapy is currently increasing, but combination therapy with DNA repair inhibitors remains to be exploited in the clinic. The high-linear energy transfer (LET) radiation delivered by charged particles causes clustered DNA damage, which is particularly effective in destroying cancer cells. Whether the DNA damage response to this type of damage is different from that elicited in response to low-LET radiation, and if and how it can be targeted to increase treatment efficacy, is not fully understood. Although several preclinical studies have reported radiosensitizing effects when proton or carbon ion irradiation is combined with inhibitors of, e.g., PARP, ATR, ATM, or DNA-PKcs, further exploration is required to determine the most effective treatments. Here, we examine what is known about repair pathway choice in response to high- versus low-LET irradiation, and we discuss the effects of inhibitors of these pathways when combined with protons and carbon ions. Additionally, we explore the potential effects of DNA repair inhibitors on antitumor immune signaling upon proton and carbon ion irradiation. Due to the reduced effect on healthy tissue and better immune preservation, particle therapy may be particularly well suited for combination with DNA repair inhibitors.
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Affiliation(s)
- Gro Elise Rødland
- Department of Radiation Biology, Institute for Cancer Research, Norwegian Radium Hospital, Oslo University Hospital, 0379 Oslo, Norway
| | - Mihaela Temelie
- Department of Life and Environmental Physics, Horia Hulubei National Institute of Physics and Nuclear Engineering, 077125 Magurele, Romania
| | - Adrian Eek Mariampillai
- Department of Radiation Biology, Institute for Cancer Research, Norwegian Radium Hospital, Oslo University Hospital, 0379 Oslo, Norway
| | - Sissel Hauge
- Department of Radiation Biology, Institute for Cancer Research, Norwegian Radium Hospital, Oslo University Hospital, 0379 Oslo, Norway
| | - Antoine Gilbert
- UMR6252 CIMAP, Team Applications in Radiobiology with Accelerated Ions, CEA-CNRS-ENSICAEN-Université de Caen Normandie, 14000 Caen, France (F.C.)
| | - François Chevalier
- UMR6252 CIMAP, Team Applications in Radiobiology with Accelerated Ions, CEA-CNRS-ENSICAEN-Université de Caen Normandie, 14000 Caen, France (F.C.)
| | - Diana I. Savu
- Department of Life and Environmental Physics, Horia Hulubei National Institute of Physics and Nuclear Engineering, 077125 Magurele, Romania
| | - Randi G. Syljuåsen
- Department of Radiation Biology, Institute for Cancer Research, Norwegian Radium Hospital, Oslo University Hospital, 0379 Oslo, Norway
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3
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Lohberger B, Barna S, Glänzer D, Eck N, Leithner A, Georg D. DNA-PKcs Inhibition Sensitizes Human Chondrosarcoma Cells to Carbon Ion Irradiation via Cell Cycle Arrest and Telomere Capping Disruption. Int J Mol Sci 2024; 25:6179. [PMID: 38892366 PMCID: PMC11173223 DOI: 10.3390/ijms25116179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 05/27/2024] [Accepted: 05/30/2024] [Indexed: 06/21/2024] Open
Abstract
In order to overcome the resistance to radiotherapy in human chondrosarcoma cells, the prevention from efficient DNA repair with a combined treatment with the DNA-dependent protein kinase catalytic subunit (DNA-PKcs) inhibitor AZD7648 was explored for carbon ion (C-ion) as well as reference photon (X-ray) irradiation (IR) using gene expression analysis, flow cytometry, protein phosphorylation, and telomere length shortening. Proliferation markers and cell cycle distribution changed significantly after combined treatment, revealing a prominent G2/M arrest. The expression of the G2/M checkpoint genes cyclin B, CDK1, and WEE1 was significantly reduced by IR alone and the combined treatment. While IR alone showed no effects, additional AZD7648 treatment resulted in a dose-dependent reduction in AKT phosphorylation and an increase in Chk2 phosphorylation. Twenty-four hours after IR, the key genes of DNA repair mechanisms were reduced by the combined treatment, which led to impaired DNA repair and increased radiosensitivity. A time-dependent shortening of telomere length was observed in both cell lines after combined treatment with AZD7648 and 8 Gy X-ray/C-ion IR. Our data suggest that the inhibition of DNA-PKcs may increase sensitivity to X-rays and C-ion IR by impairing its functional role in DNA repair mechanisms and telomere end protection.
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Affiliation(s)
- Birgit Lohberger
- Department of Orthopedics and Trauma, Medical University of Graz, Auenbruggerplatz 5-7, 8036 Graz, Austria; (D.G.); (N.E.); (A.L.)
| | - Sandra Barna
- Department of Radiation Oncology, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria; (S.B.); (D.G.)
- MedAustron-Ion Therapy Center, Viktor-Kaplan Strasse 2, 2700 Wiener Neustadt, Austria
| | - Dietmar Glänzer
- Department of Orthopedics and Trauma, Medical University of Graz, Auenbruggerplatz 5-7, 8036 Graz, Austria; (D.G.); (N.E.); (A.L.)
| | - Nicole Eck
- Department of Orthopedics and Trauma, Medical University of Graz, Auenbruggerplatz 5-7, 8036 Graz, Austria; (D.G.); (N.E.); (A.L.)
| | - Andreas Leithner
- Department of Orthopedics and Trauma, Medical University of Graz, Auenbruggerplatz 5-7, 8036 Graz, Austria; (D.G.); (N.E.); (A.L.)
| | - Dietmar Georg
- Department of Radiation Oncology, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria; (S.B.); (D.G.)
- MedAustron-Ion Therapy Center, Viktor-Kaplan Strasse 2, 2700 Wiener Neustadt, Austria
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Han Y, Zhao H, Li G, Jia J, Guo H, Tan J, Sun X, Li S, Ran Q, Bai C, Gu Y, Li Z, Guan H, Gao S, Zhou PK. GCN5 mediates DNA-PKcs crotonylation for DNA double-strand break repair and determining cancer radiosensitivity. Br J Cancer 2024; 130:1621-1634. [PMID: 38575732 PMCID: PMC11091118 DOI: 10.1038/s41416-024-02636-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 02/18/2024] [Accepted: 02/21/2024] [Indexed: 04/06/2024] Open
Abstract
BACKGROUND DNA double-strand break (DSB) induction and repair are important events for determining cell survival and the outcome of cancer radiotherapy. The DNA-dependent protein kinase (DNA-PK) complex functions at the apex of DSBs repair, and its assembly and activity are strictly regulated by post-translation modifications (PTMs)-associated interactions. However, the PTMs of the catalytic subunit DNA-PKcs and how they affect DNA-PKcs's functions are not fully understood. METHODS Mass spectrometry analyses were performed to identify the crotonylation sites of DNA-PKcs in response to γ-ray irradiation. Co-immunoprecipitation (Co-IP), western blotting, in vitro crotonylation assays, laser microirradiation assays, in vitro DNA binding assays, in vitro DNA-PK assembly assays and IF assays were employed to confirm the crotonylation, identify the crotonylase and decrotonylase, and elucidate how crotonylation regulates the activity and function of DNA-PKcs. Subcutaneous xenografts of human HeLa GCN5 WT or HeLa GCN5 siRNA cells in BALB/c nude mice were generated and utilized to assess tumor proliferation in vivo after radiotherapy. RESULTS Here, we reveal that K525 is an important site of DNA-PKcs for crotonylation, and whose level is sharply increased by irradiation. The histone acetyltransferase GCN5 functions as the crotonylase for K525-Kcr, while HDAC3 serves as its dedicated decrotonylase. K525 crotonylation enhances DNA binding activity of DNA-PKcs, and facilitates assembly of the DNA-PK complex. Furthermore, GCN5-mediated K525 crotonylation is indispensable for DNA-PKcs autophosphorylation and the repair of double-strand breaks in the NHEJ pathway. GCN5 suppression significantly sensitizes xenograft tumors of mice to radiotherapy. CONCLUSIONS Our study defines K525 crotonylation of DNA-PKcs is important for the DNA-PK complex assembly and DSBs repair activity via NHEJ pathway. Targeting GCN5-mediated K525 Kcr of DNA-PKcs may be a promising therapeutic strategy for improving the outcome of cancer radiotherapy.
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Affiliation(s)
- Yang Han
- Department of Radiation Biology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Hongling Zhao
- Department of Radiation Biology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Gang Li
- School of Public Health, Institute for Environmental Medicine and Radiation Hygiene, University of South China, Hengyang, China
- Department of Hospital Infection Control, Shenzhen Luohu Peoples Hospital, Shenzhen, China
| | - Jin Jia
- School of Medicine, University of South China, Hengyang, China
| | - Hejiang Guo
- Department of Radiation Biology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Jinpeng Tan
- School of Medicine, University of South China, Hengyang, China
| | - Xingyao Sun
- School of Medicine, University of South China, Hengyang, China
| | - Saiyu Li
- School of life Sciences, Hebei University, Baoding, China
| | - Qian Ran
- Laboratory of Radiation Biology, Laboratory Medicine Center, Department of Blood Transfusion, The Second Affiliated Hospital, Army Military Medical University, Chongqing, China
| | - Chenjun Bai
- Department of Radiation Biology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Yongqing Gu
- Department of Radiation Biology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, China
| | - ZhongJun Li
- Laboratory of Radiation Biology, Laboratory Medicine Center, Department of Blood Transfusion, The Second Affiliated Hospital, Army Military Medical University, Chongqing, China.
| | - Hua Guan
- Department of Radiation Biology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, China.
| | - Shanshan Gao
- Department of Radiation Biology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, China.
| | - Ping-Kun Zhou
- Department of Radiation Biology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, China.
- School of Public Health, Institute for Environmental Medicine and Radiation Hygiene, University of South China, Hengyang, China.
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Ng YB, Akincilar SC. Shaping DNA damage responses: Therapeutic potential of targeting telomeric proteins and DNA repair factors in cancer. Curr Opin Pharmacol 2024; 76:102460. [PMID: 38776747 DOI: 10.1016/j.coph.2024.102460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 10/06/2023] [Accepted: 10/11/2023] [Indexed: 05/25/2024]
Abstract
Shelterin proteins regulate genomic stability by preventing inappropriate DNA damage responses (DDRs) at telomeres. Unprotected telomeres lead to persistent DDR causing cell cycle inhibition, growth arrest, and apoptosis. Cancer cells rely on DDR to protect themselves from DNA lesions and exogenous DNA-damaging agents such as chemotherapy and radiotherapy. Therefore, targeting DDR machinery is a promising strategy to increase the sensitivity of cancer cells to existing cancer therapies. However, the success of these DDR inhibitors depends on other mutations, and over time, patients develop resistance to these therapies. This suggests the need for alternative approaches. One promising strategy is co-inhibiting shelterin proteins with DDR molecules, which would offset cellular fitness in DNA repair in a mutation-independent manner. This review highlights the associations and dependencies of the shelterin complex with the DDR proteins and discusses potential co-inhibition strategies that might improve the therapeutic potential of current inhibitors.
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Affiliation(s)
- Yu Bin Ng
- Laboratory of NFκB Signalling, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A∗STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Republic of Singapore
| | - Semih Can Akincilar
- Laboratory of NFκB Signalling, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A∗STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Republic of Singapore.
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Mentzel J, Hildebrand LS, Kuhlmann L, Fietkau R, Distel LV. Effective Radiosensitization of HNSCC Cell Lines by DNA-PKcs Inhibitor AZD7648 and PARP Inhibitors Talazoparib and Niraparib. Int J Mol Sci 2024; 25:5629. [PMID: 38891817 PMCID: PMC11172136 DOI: 10.3390/ijms25115629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 05/16/2024] [Accepted: 05/19/2024] [Indexed: 06/21/2024] Open
Abstract
(1) Head and neck squamous cell carcinoma (HNSCC) is common, while treatment is difficult, and mortality is high. Kinase inhibitors are promising to enhance the effects of radiotherapy. We compared the effects of the PARP inhibitors talazoparib and niraparib and that of the DNA-PKcs inhibitor AZD7648, combined with ionizing radiation. (2) Seven HNSCC cell lines, including Cal33, CLS-354, Detroit 562, HSC4, RPMI2650 (HPV-negative), UD-SCC-2 and UM-SCC-47 (HPV-positive), and two healthy fibroblast cell lines, SBLF8 and SBLF9, were studied. Flow cytometry was used to analyze apoptosis and necrosis induction (AnnexinV/7AAD) and cell cycle distribution (Hoechst). Cell inactivation was studied by the colony-forming assay. (3) AZD7648 had the strongest effects, radiosensitizing all HNSCC cell lines, almost always in a supra-additive manner. Talazoparib and niraparib were effective in both HPV-positive cell lines but only consistently in one and two HPV-negative cell lines, respectively. Healthy fibroblasts were not affected by any combined treatment in apoptosis and necrosis induction or G2/M-phase arrest. AZD7648 alone was not toxic to healthy fibroblasts, while the combination with ionizing radiation reduced clonogenicity. (4) In conclusion, talazoparib, niraparib and, most potently, AZD7648 could improve radiation therapy in HNSCC. Healthy fibroblasts tolerated AZD7648 alone extremely well, but irradiation-induced effects might occur. Our results justify in vivo studies.
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Affiliation(s)
- Jacob Mentzel
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany; (J.M.); (L.S.H.); (L.K.); (R.F.)
- Comprehensive Cancer Center Erlangen-Europäische Metropolregion Nürnberg (CCC ER-EMN), 91054 Erlangen, Germany
| | - Laura S. Hildebrand
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany; (J.M.); (L.S.H.); (L.K.); (R.F.)
- Comprehensive Cancer Center Erlangen-Europäische Metropolregion Nürnberg (CCC ER-EMN), 91054 Erlangen, Germany
| | - Lukas Kuhlmann
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany; (J.M.); (L.S.H.); (L.K.); (R.F.)
- Comprehensive Cancer Center Erlangen-Europäische Metropolregion Nürnberg (CCC ER-EMN), 91054 Erlangen, Germany
| | - Rainer Fietkau
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany; (J.M.); (L.S.H.); (L.K.); (R.F.)
- Comprehensive Cancer Center Erlangen-Europäische Metropolregion Nürnberg (CCC ER-EMN), 91054 Erlangen, Germany
| | - Luitpold V. Distel
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany; (J.M.); (L.S.H.); (L.K.); (R.F.)
- Comprehensive Cancer Center Erlangen-Europäische Metropolregion Nürnberg (CCC ER-EMN), 91054 Erlangen, Germany
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Zaid A, Ariel A. Harnessing anti-inflammatory pathways and macrophage nano delivery to treat inflammatory and fibrotic disorders. Adv Drug Deliv Rev 2024; 207:115204. [PMID: 38342241 DOI: 10.1016/j.addr.2024.115204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Revised: 12/08/2023] [Accepted: 02/05/2024] [Indexed: 02/13/2024]
Abstract
Targeting specific organs and cell types using nanotechnology and sophisticated delivery methods has been at the forefront of applicative biomedical sciences lately. Macrophages are an appealing target for immunomodulation by nanodelivery as they are heavily involved in various aspects of many diseases and are highly plastic in their nature. Their continuum of functional "polarization" states has been a research focus for many years yielding a profound understanding of various aspects of these cells. The ability of monocyte-derived macrophages to metamorphose from pro-inflammatory to reparative and consequently to pro-resolving effectors has raised significant interest in its therapeutic potential. Here, we briefly survey macrophages' ontogeny and various polarization phenotypes, highlighting their function in the inflammation-resolution shift. We review their inducing mediators, signaling pathways, and biological programs with emphasis on the nucleic acid sensing-IFN-I axis. We also portray the polarization spectrum of macrophages and the characteristics of their transition between different subtypes. Finally, we highlighted different current drug delivery methods for targeting macrophages with emphasis on nanotargeting that might lead to breakthroughs in the treatment of wound healing, bone regeneration, autoimmune, and fibrotic diseases.
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Affiliation(s)
- Ahmad Zaid
- Department of Biology and Human Biology, University of Haifa, Haifa, 3498838 Israel
| | - Amiram Ariel
- Department of Biology and Human Biology, University of Haifa, Haifa, 3498838 Israel.
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Shih YL, Hsu SY, Lai KC, Chueh FS, Huang YL, Kuo CL, Chen YL, Chen CJ, Peng SF, Huang WW, Lu HF. Allyl isothiocyanate induces DNA damage and inhibits DNA repair-associated proteins in a human gastric cancer cells in vitro. ENVIRONMENTAL TOXICOLOGY 2024; 39:1303-1314. [PMID: 37966020 DOI: 10.1002/tox.24020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 09/07/2023] [Accepted: 10/07/2023] [Indexed: 11/16/2023]
Abstract
Allyl isothiocyanate (AITC) is abundant in cruciferous vegetables and it present pharmacological activity including anticancer activity in many types of human cancer cells in vitro and in vivo. Currently, no available information to show AITC affecting DNA damage and repair-associated protein expression in human gastric cancer cells. Therefore, in the present studies, we investigated AITC-induced cytotoxic effects on human gastric cancer in AGS and SNU-1 cells whether or not via the induction of DNA damage and affected DNA damage and repair associated poteins expressions in vitro. Cell viability and morphological changes were assayed by flow cytometer and phase contrast microscopy, respectively, the results indicated AITC induced cell morphological changes and decreased total viable cells in AGS and SNU-1 cells in a dose-dependently. AITC induced DNA condensation and damage in a dose-dependently which based on the cell nuclei was stained by 4', 6-diamidino-2-phenylindole present in AGS and SNU-1 cells. DNA damage and repair associated proteins expression in AGS and SNU-1 cells were measured by Western blotting. The results indicated AITC decreased nuclear factor erythroid 2-related factor 2 (NRF2), heme oxygenase-1 (HO-1), glutathione, and catalase, but increased superoxide dismutase (SOD (Cu/Zn)), and nitric oxide synthase (iNOS) in AGS cells, however, in SNU-1 cells are increased HO-1. AITC increased DNA-dependent protein kinase (DNA-PK), phosphorylation of gamma H2A histone family member X on Ser139 (γH2AXpSer139 ), and heat shock protein 90 (HSP90) in AGS cells. AITC increased DNA-PK, mediator of DNA damage checkpoint protein 1 (MDC1), γH2AXpSer139 , topoisomerase II alpha (TOPIIα), topoisomerase II beta (TOPIIβ), HSP90, and heat shock protein 70 (HSP70) in SNU-1 cells. AITC increased p53, p53pSer15 , and p21 but decreased murine double minute 2 (MDM2)pSer166 and O6 -methylguanine-DNA methyltransferase (MGMT) in AGS cells; however, it has a similar effect of AITC except increased ataxia telangiectasia and Rad3 -related protein (ATR)pSer428 , checkpoint kinase 1 (CHK1), and checkpoint kinase 2 (CHK2) in SNU-1 cells. Apparently, both cell responses to AITC are different, nonetheless, all of these observations suggest that AITC inhibits the growth of gastric cancer cells may through induction off DNA damage in vitro.
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Affiliation(s)
- Yung-Luen Shih
- School of Medicine, College of Medicine, Fu-Jen Catholic University, New Taipei, Taiwan
- Department of Pathology and Laboratory Medicine, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan
| | - Sheng-Yao Hsu
- Department of Ophthalmology, An Nan Hospital, China Medical University, Tainan, Taiwan
- Department of Optometry, Chung Hwa University of Medical Technology, Tainan, Taiwan
| | - Kuang-Chi Lai
- Department of Surgery, School of Medicine, China Medical University, Taichung, Taiwan
- Department of Medical Laboratory Science and Biotechnology, College of Medical Technology, Chung Hwa University of Medical Technology, Tainan, Taiwan
| | - Fu-Shin Chueh
- Department of Food Nutrition and Health Biotechnology, Asia University, Taichung, Taiwan
| | - Yuan-Li Huang
- Department of Medical Laboratory Science and Biotechnology, Asia University, Taichung, Taiwan
| | - Chao-Lin Kuo
- Department of Chinese Pharmaceutical Sciences and Chinese Medicine Resources, China Medical University, Taichung, Taiwan
| | - Yung-Liang Chen
- Department of Medical Laboratory Science and Biotechnology, Yuanpei University, Hsinchu, Taiwan
| | - Chiung-Ju Chen
- Department of Pathology and Laboratory Medicine, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan
- Jen-Teh Junior College of Medicine, Nursing and Management, Miaoli, Taiwan
| | - Shu-Fen Peng
- Department of Medical Research, China Medical University Hospital, Taichung, Taiwan
- Department of Biological Science and Technology, China Medical University, Taichung, Taiwan
| | - Wen-Wen Huang
- Department of Biological Science and Technology, China Medical University, Taichung, Taiwan
| | - Hsu-Fen Lu
- Department of Medical Laboratory Science and Biotechnology, Asia University, Taichung, Taiwan
- Department of Laboratory Medicine, China Medical University Hospital, Taichung, Taiwan
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9
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Laroche-Clary A, Josensi C, Derieppe MA, Belhomme S, Vendrely V, Perret R, Cadogan E, Italiano A. Selective DNA-PK Inhibition Enhances Chemotherapy and Ionizing Radiation Activity in Soft-Tissue Sarcomas. Clin Cancer Res 2024; 30:629-637. [PMID: 37982819 DOI: 10.1158/1078-0432.ccr-23-1531] [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: 05/23/2023] [Revised: 07/25/2023] [Accepted: 11/16/2023] [Indexed: 11/21/2023]
Abstract
PURPOSE Patients with advanced soft-tissue sarcomas (STS) exhibit a poor prognosis and have few therapeutic options. DNA-dependent protein kinase (DNA-PK) catalytic subunit is a multifunctional serine-threonine protein kinase that plays a crucial role in DNA double-strand damage repair via nonhomologous end joining. EXPERIMENTAL DESIGN To investigate the therapeutic potential of DNA-PK targeting in STS, we first evaluated the prognostic value of DNA-PK expression in two large cohorts of patients with STS. We then used the potent and selective DNA-PK inhibitor AZD7648 compound to investigate the antitumor effect of the pharmacologic inhibition of DNA-PK in vitro via MTT, apoptosis, cell cycle, and proliferation assays. In vivo studies were performed with patient-derived xenograft models to evaluate the effects of AZD7648 in combination with chemotherapy or ionizing radiation on tumor growth. The mechanisms of sensitivity and resistance to DNA-PK inhibition were investigated by using a genome-wide CRISPR-Cas9 positive screen. RESULTS DNA-PK overexpression is significantly associated with poor prognosis in patients with sarcomas. Selective pharmacologic inhibition of DNA-PK strongly synergizes with radiation- and doxorubicin-based regimen in sarcoma models. By using a genome-wide CRISPR-Cas9 positive screen, we identified genes involved in sensitivity to DNA-PK inhibition. CONCLUSIONS DNA-PK inhibition deserves clinical investigation to improve response to current therapies in patients with sarcoma.
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Affiliation(s)
- Audrey Laroche-Clary
- Sarcoma Unit, Institut Bergonié, Bordeaux, France
- INSERM, U1312, Bordeaux, France
| | - Coralie Josensi
- Sarcoma Unit, Institut Bergonié, Bordeaux, France
- INSERM, U1312, Bordeaux, France
| | | | - Sarah Belhomme
- Department of Radiation Therapy, Institut Bergonié, Bordeaux, France
| | | | - Raul Perret
- Department of Pathology, Institut Bergonié, Bordeaux, France
| | | | - Antoine Italiano
- Sarcoma Unit, Institut Bergonié, Bordeaux, France
- INSERM, U1312, Bordeaux, France
- Faculty of Medicine, University of Bordeaux, Bordeaux, France
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10
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Yu Y, Jia H, Zhang T, Zhang W. Advances in DNA damage response inhibitors in colorectal cancer therapy. Acta Biochim Biophys Sin (Shanghai) 2024; 56:15-22. [PMID: 38115743 PMCID: PMC10875349 DOI: 10.3724/abbs.2023278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 08/23/2023] [Indexed: 12/21/2023] Open
Abstract
One potential cause of cancer is genomic instability that arises in normal cells due to years of DNA damage in the body. The clinical application of radiotherapy and cytotoxic drugs to treat cancer is based on the principle of damaging the DNA of cancer cells. However, the benefits of these treatments also have negative effects on normal tissue. While there have been notable advancements in molecular-driven therapy and immunotherapy for colorectal cancer (CRC), a considerable portion of patients with advanced CRC do not experience any benefits from these treatments, leading to a poor prognosis. In recent years, targeted therapy aimed at suppressing the DNA damage response (DDR) in cancer cells has emerged as a potential treatment option for CRC patients, offering them more choices for treatment. Currently, the integration of DDR and clinical intervention remains in the exploratory phase. This review primarily elucidates the fundamental principles of DDR inhibitors, provides an overview of their current clinical application status in CRC, and discusses the advancements as well as limitations observed in relevant studies.
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Affiliation(s)
- Yue Yu
- />Department of Colorectal Surgerythe First Affiliated HospitalNaval Medical UniversityShanghai200433China
| | - Hang Jia
- />Department of Colorectal Surgerythe First Affiliated HospitalNaval Medical UniversityShanghai200433China
| | - Tianshuai Zhang
- />Department of Colorectal Surgerythe First Affiliated HospitalNaval Medical UniversityShanghai200433China
| | - Wei Zhang
- />Department of Colorectal Surgerythe First Affiliated HospitalNaval Medical UniversityShanghai200433China
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11
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Marshall S, Navarro MV, Ascenҫão CF, Smolka MB. IN-DEPTH MAPPING OF DNA-PKcs SIGNALING UNCOVERS CONSERVED FEATURES OF ITS KINASE SPECIFICITY. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.17.576037. [PMID: 38293078 PMCID: PMC10827184 DOI: 10.1101/2024.01.17.576037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
DNA-PKcs is a DNA damage sensor kinase with established roles in DNA double-strand break repair via non-homologous end joining. Recent studies have revealed additional roles of DNA-PKcs in the regulation of transcription, translation and DNA replication. However, the substrates through which DNA-PKcs regulates these processes remain largely undefined. Here we utilized quantitative phosphoproteomics to generate a high coverage map of DNA-PKcs signaling in response to ionizing radiation and mapped its interplay with the ATM kinase. Beyond the detection of the canonical S/T-Q phosphorylation motif, we uncovered a non-canonical mode of DNA-PKcs signaling targeting S/T-ψ-D/E motifs. Cross-species analysis in mouse pre-B and human HCT116 cell lines revealed splicing factors and transcriptional regulators phosphorylated at this novel motif, several of which contain SAP domains. These findings expand the list of DNA-PKcs and ATM substrates and establish a novel preferential phosphorylation motif for DNA-PKcs that connects it to proteins involved in nucleotide processes and interactions.
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Affiliation(s)
- Shannon Marshall
- 1. Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - Marcos V.A.S. Navarro
- 1. Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
- 2. IFSC Institute of Physics of São Carlos, University of São Paulo, São Carlos - SP, 13566-590, Brazil
| | - Carolline F.R. Ascenҫão
- 1. Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - Marcus B. Smolka
- 1. Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
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12
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Liu K, Yuan X, Yang T, Deng D, Chen Y, Tang M, Zhang C, Zou Y, Zhang S, Li D, Shi M, Guo Y, Zhou Y, Zhao M, Yang Z, Chen L. Discovery, Optimization, and Evaluation of Potent and Selective DNA-PK Inhibitors in Combination with Chemotherapy or Radiotherapy for the Treatment of Malignancies. J Med Chem 2024; 67:245-271. [PMID: 38117951 DOI: 10.1021/acs.jmedchem.3c01338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2023]
Abstract
Given the multifaceted biological functions of DNA-PK encompassing DNA repair pathways and beyond, coupled with the susceptibility of DNA-PK-deficient cells to DNA-damaging agents, significant strides have been made in the pursuit of clinical potential for DNA-PK inhibitors as synergistic adjuncts to chemo- or radiotherapy. Nevertheless, although substantial progress has been made with the discovery of potent inhibitors of DNA-PK, the clinical trial landscape requires even more potent and selective molecules. This necessitates further endeavors to expand the repertoire of clinically accessible DNA-PK inhibitors for the ultimate benefit of patients. Described herein are the obstacles that were encountered and the solutions that were found, which eventually led to the identification of compound 31t. This compound exhibited a remarkable combination of robust potency and exceptional selectivity along with favorable in vivo profiles as substantiated by pharmacokinetic studies in rats and pharmacodynamic assessments in H460, BT474, and A549 xenograft models.
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Affiliation(s)
- Kongjun Liu
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Cancer Center, Collaborative Innovation Center of Biotherapy, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Xue Yuan
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Cancer Center, Collaborative Innovation Center of Biotherapy, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Tao Yang
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Cancer Center, Collaborative Innovation Center of Biotherapy, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Dexin Deng
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Cancer Center, Collaborative Innovation Center of Biotherapy, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Yong Chen
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Cancer Center, Collaborative Innovation Center of Biotherapy, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Minghai Tang
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Cancer Center, Collaborative Innovation Center of Biotherapy, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Chufeng Zhang
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Cancer Center, Collaborative Innovation Center of Biotherapy, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Yurong Zou
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Cancer Center, Collaborative Innovation Center of Biotherapy, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Shunjie Zhang
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Cancer Center, Collaborative Innovation Center of Biotherapy, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Dan Li
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Cancer Center, Collaborative Innovation Center of Biotherapy, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Mingsong Shi
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Cancer Center, Collaborative Innovation Center of Biotherapy, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Yong Guo
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Cancer Center, Collaborative Innovation Center of Biotherapy, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Yanting Zhou
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Cancer Center, Collaborative Innovation Center of Biotherapy, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Min Zhao
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Cancer Center, Collaborative Innovation Center of Biotherapy, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Zhuang Yang
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Cancer Center, Collaborative Innovation Center of Biotherapy, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Lijuan Chen
- Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Cancer Center, Collaborative Innovation Center of Biotherapy, West China Hospital of Sichuan University, Chengdu 610041, China
- Chengdu Zenitar Biomedical Technology Co., Ltd., Chengdu 610041, China
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13
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Kim S, Kim Y, Lee JY. Real-time single-molecule visualization using DNA curtains reveals the molecular mechanisms underlying DNA repair pathways. DNA Repair (Amst) 2024; 133:103612. [PMID: 38128155 DOI: 10.1016/j.dnarep.2023.103612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 10/06/2023] [Accepted: 12/10/2023] [Indexed: 12/23/2023]
Abstract
The demand for direct observation of biomolecular interactions provides new insights into the molecular mechanisms underlying many biological processes. Single-molecule imaging techniques enable real-time visualization of individual biomolecules, providing direct observations of protein machines. Various single-molecule imaging techniques have been developed and have contributed to breakthroughs in biological research. One such technique is the DNA curtain, a novel, high-throughput, single-molecule platform that integrates lipid fluidity, nano-fabrication, microfluidics, and fluorescence imaging. Many DNA metabolic reactions, such as replication, transcription, and chromatin dynamics, have been studied using DNA curtains. In particular, the DNA curtain platform has been intensively applied in investigating the molecular details of DNA repair processes. This article reviews DNA curtain techniques and their applications for imaging DNA repair proteins.
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Affiliation(s)
- Subin Kim
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan, South Korea
| | - Youngseo Kim
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan, South Korea
| | - Ja Yil Lee
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan, South Korea.
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14
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Becker A, Krebs‐Brown A, Vetter C, Reuter T, Rodriguez‐Gutierrez A, You X, Lissy M. Phase I crossover study of DNA-protein kinase inhibitor peposertib in healthy volunteers: Effect of food and pharmacokinetics of an oral suspension. Clin Transl Sci 2023; 16:2628-2639. [PMID: 37905356 PMCID: PMC10719468 DOI: 10.1111/cts.13657] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 08/30/2023] [Accepted: 08/31/2023] [Indexed: 11/02/2023] Open
Abstract
Peposertib is an orally administered inhibitor of DNA-dependent protein kinase. We evaluated the effect of food on its pharmacokinetics, and examined the pharmacokinetics of an oral suspension (OS) of disintegrated tablets, in a phase I, open-label, crossover three-period study (NCT04702698). Twelve healthy volunteers were randomized to one of six treatment sequences. They received a single dose of peposertib 100 mg as film-coated tablets under fasted or fed conditions ("tablet fasted" or "tablet fed") or as an OS under fasted conditions ("OS fasted"), with washout between treatments. Using healthy volunteers was possible because, despite its mechanism of action being suppression of DNA repair, peposertib has shown no genotoxic effect in animals. A mild food effect was observed with peposertib tablets. Fed-to-fasted ratios were: area under the curve from time 0 to time t (AUC0-t ), 123.81% (90% confidence interval [CI]: 108.04, 141.87%); AUC from zero to infinity (AUC0-∞ ), 110.28% (90% CI 100.71, 120.77%); and maximum concentration (Cmax ) 104.47% (90% CI: 79.15, 137.90%). Cmax was delayed under fed conditions (median time to maximum concentration [Tmax ] was 3.5 h [tablet fed] vs. 1 h [tablet fasted]). OS-to-tablet (fasted) ratios were: AUC0-t , 124.83% (90% CI: 111.50%, 139.76%); AUC0-∞ , 119.05% (90% CI: 104.47, 135.67%); and Cmax 173.29% (90% CI: 135.78, 221.16%). Median Tmax was 0.5 h (OS fasted) versus 1 h (tablet). All treatments were well-tolerated in healthy volunteers. Peposertib tablets can be taken with or without food; if combined with chemotherapy or radiotherapy, the delay in Cmax must be considered to optimize the chemo- or radiosensitizing effect. The peposertib OS form represents an alternative route of administration in patients with specific cancers causing dysphagia. However, the OS form should be part of future dose optimization strategies in relevant settings.
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Affiliation(s)
| | | | | | - Tanja Reuter
- The healthcare business of Merck KGaADarmstadtGermany
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15
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Vogt A, He Y, Lees-Miller SP. How to fix DNA breaks: new insights into the mechanism of non-homologous end joining. Biochem Soc Trans 2023; 51:1789-1800. [PMID: 37787023 PMCID: PMC10657183 DOI: 10.1042/bst20220741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Revised: 08/26/2023] [Accepted: 09/22/2023] [Indexed: 10/04/2023]
Abstract
Non-homologous end joining (NHEJ) is the major pathway for the repair of ionizing radiation-induced DNA double-strand breaks (DSBs) in human cells and is essential for the generation of mature T and B cells in the adaptive immune system via the process of V(D)J recombination. Here, we review how recently determined structures shed light on how NHEJ complexes function at DNA DSBs, emphasizing how multiple structures containing the DNA-dependent protein kinase catalytic subunit (DNA-PKcs) may function in NHEJ. Together, these studies provide an explanation for how NHEJ proteins assemble to detect and protect DSB ends, then proceed, through DNA-PKcs-dependent autophosphorylation, to a ligation-competent complex.
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Affiliation(s)
- Alex Vogt
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, U.S.A
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, U.S.A
| | - Yuan He
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, U.S.A
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, U.S.A
- Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, U.S.A
- Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Northwestern University, Chicago, U.S.A
| | - Susan P. Lees-Miller
- Department of Biochemistry and Molecular Biology, Robson DNA Science Centre and Arnie Charbonneau Cancer Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada
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16
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Raval S, Douglas P, Laurent D, Khan MF, Lees-Miller SP, Schriemer DC. High-Efficiency Enrichment by Saturating Nanoliters of Protein Affinity Media. Anal Chem 2023; 95:15884-15892. [PMID: 37851921 PMCID: PMC11234515 DOI: 10.1021/acs.analchem.3c01736] [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] [Indexed: 10/20/2023]
Abstract
Affinity-purification mass spectrometry (AP-MS) is an established technique for identifying protein-protein interactions (PPIs). The basic technology involves immobilizing a high-specificity ligand to a solid-phase support (e.g., an agarose or magnetic bead) to pull down protein(s) of interest from cell lysates. Although these supports are engineered to minimize interactions with background protein, the conventional method recovers mostly nonspecific binders. The law of mass action for dilute solutions has taught us to use an excess of beads to capture all target proteins, especially weakly interacting ones. However, modern microbead technology presents a binding environment that is much different from a dilute solution. We describe a fluidic platform that captures and processes ultralow nanoliter quantities of magnetic particles, simultaneously increasing the efficiency of PPI detection and strongly suppressing nonspecific binding. We demonstrate the concept with synthetic mixtures of tagged protein and illustrate performance with a variety of AP-MS experiment types. These include a BioID experiment targeting lamin-A interactors from HeLa cells and pulldowns using GFP-tagged proteins associated with a double-strand DNA repair mechanism. We show that efficient extraction requires saturation of the solid-phase support and that <10 nL of beads is sufficient to generate comprehensive protein interaction maps.
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Affiliation(s)
- Shaunak Raval
- Department of Biochemistry and Molecular Biology, University of Calgary, Alberta, Canada, T2N-4N1
- Department of Chemistry, University of Calgary, Calgary, Alberta, Canada T2N-4N1
| | - Pauline Douglas
- Department of Biochemistry and Molecular Biology, University of Calgary, Alberta, Canada, T2N-4N1
| | - Danny Laurent
- Department of Biochemistry and Molecular Biology, University of Calgary, Alberta, Canada, T2N-4N1
| | - Morgan F. Khan
- Department of Biochemistry and Molecular Biology, University of Calgary, Alberta, Canada, T2N-4N1
| | - Susan P. Lees-Miller
- Department of Biochemistry and Molecular Biology, University of Calgary, Alberta, Canada, T2N-4N1
| | - David C. Schriemer
- Department of Biochemistry and Molecular Biology, University of Calgary, Alberta, Canada, T2N-4N1
- Department of Chemistry, University of Calgary, Calgary, Alberta, Canada T2N-4N1
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17
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Loparo JJ. Holding it together: DNA end synapsis during non-homologous end joining. DNA Repair (Amst) 2023; 130:103553. [PMID: 37572577 PMCID: PMC10530278 DOI: 10.1016/j.dnarep.2023.103553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 08/04/2023] [Accepted: 08/06/2023] [Indexed: 08/14/2023]
Abstract
DNA double strand breaks (DSBs) are common lesions whose misrepair are drivers of oncogenic transformations. The non-homologous end joining (NHEJ) pathway repairs the majority of these breaks in vertebrates by directly ligating DNA ends back together. Upon formation of a DSB, a multiprotein complex is assembled on DNA ends which tethers them together within a synaptic complex. Synapsis is a critical step of the NHEJ pathway as loss of synapsis can result in mispairing of DNA ends and chromosome translocations. As DNA ends are commonly incompatible for ligation, the NHEJ machinery must also process ends to enable rejoining. This review describes how recent progress in single-molecule approaches and cryo-EM have advanced our molecular understanding of DNA end synapsis during NHEJ and how synapsis is coordinated with end processing to determine the fidelity of repair.
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Affiliation(s)
- Joseph J Loparo
- Dept. of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.
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18
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Deshpande RA, Marin-Gonzalez A, Barnes HK, Woolley PR, Ha T, Paull TT. Genome-wide analysis of DNA-PK-bound MRN cleavage products supports a sequential model of DSB repair pathway choice. Nat Commun 2023; 14:5759. [PMID: 37717054 PMCID: PMC10505227 DOI: 10.1038/s41467-023-41544-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 09/07/2023] [Indexed: 09/18/2023] Open
Abstract
The Mre11-Rad50-Nbs1 (MRN) complex recognizes and processes DNA double-strand breaks for homologous recombination by performing short-range removal of 5' strands. Endonucleolytic processing by MRN requires a stably bound protein at the break site-a role we postulate is played by DNA-dependent protein kinase (DNA-PK) in mammals. Here we interrogate sites of MRN-dependent processing by identifying sites of CtIP association and by sequencing DNA-PK-bound DNA fragments that are products of MRN cleavage. These intermediates are generated most efficiently when DNA-PK is catalytically blocked, yielding products within 200 bp of the break site, whereas DNA-PK products in the absence of kinase inhibition show greater dispersal. Use of light-activated Cas9 to induce breaks facilitates temporal resolution of DNA-PK and Mre11 binding, showing that both complexes bind to DNA ends before release of DNA-PK-bound products. These results support a sequential model of double-strand break repair involving collaborative interactions between homologous and non-homologous repair complexes.
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Affiliation(s)
| | - Alberto Marin-Gonzalez
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Howard Hughes Medical Institute, Baltimore, MD, 21205, USA
| | - Hannah K Barnes
- The Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Phillip R Woolley
- The Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Taekjip Ha
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Howard Hughes Medical Institute, Baltimore, MD, 21205, USA
| | - Tanya T Paull
- The Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, 78712, USA.
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19
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Sobanski T, Suraweera A, Burgess JT, Richard I, Cheong CM, Dave K, Rose M, Adams MN, O'Byrne KJ, Richard DJ, Bolderson E. The fructose-bisphosphate, Aldolase A (ALDOA), facilitates DNA-PKcs and ATM kinase activity to regulate DNA double-strand break repair. Sci Rep 2023; 13:15171. [PMID: 37704669 PMCID: PMC10499815 DOI: 10.1038/s41598-023-41133-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 08/22/2023] [Indexed: 09/15/2023] Open
Abstract
Glucose metabolism and DNA repair are fundamental cellular processes frequently dysregulated in cancer. In this study, we define a direct role for the glycolytic Aldolase A (ALDOA) protein in DNA double-strand break (DSB) repair. ALDOA is a fructose biphosphate Aldolase that catalyses fructose-1,6-bisphosphate to glyceraldehyde 3-phosphate (G3P) and dihydroxyacetone phosphate (DHAP), during glycolysis. Here, we show that upon DNA damage induced by ionising radiation (IR), ALDOA translocates from the cytoplasm into the nucleus, where it partially co-localises with the DNA DSB marker γ-H2AX. DNA damage was shown to be elevated in ALDOA-depleted cells prior to IR and following IR the damage was repaired more slowly. Consistent with this, cells depleted of ALDOA exhibited decreased DNA DSB repair via non-homologous end-joining and homologous recombination. In support of the defective repair observed in its absence, ALDOA was found to associate with the major DSB repair effector kinases, DNA-dependent Protein Kinase (DNA-PK) and Ataxia Telangiectasia Mutated (ATM) and their autophosphorylation was decreased when ALDOA was depleted. Together, these data establish a role for an essential metabolic protein, ALDOA in DNA DSB repair and suggests that targeting ALDOA may enable the concurrent targeting of cancer metabolism and DNA repair to induce tumour cell death.
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Affiliation(s)
- Thais Sobanski
- Cancer and Ageing Research Program, Centre for Genomics and Personalised Health, Queensland University of Technology (QUT), Translational Research Institute (TRI), 37 Kent Street, Woolloongabba, Brisbane, Australia
| | - Amila Suraweera
- Cancer and Ageing Research Program, Centre for Genomics and Personalised Health, Queensland University of Technology (QUT), Translational Research Institute (TRI), 37 Kent Street, Woolloongabba, Brisbane, Australia
| | - Joshua T Burgess
- Cancer and Ageing Research Program, Centre for Genomics and Personalised Health, Queensland University of Technology (QUT), Translational Research Institute (TRI), 37 Kent Street, Woolloongabba, Brisbane, Australia
| | - Iain Richard
- Cancer and Ageing Research Program, Centre for Genomics and Personalised Health, Queensland University of Technology (QUT), Translational Research Institute (TRI), 37 Kent Street, Woolloongabba, Brisbane, Australia
| | - Chee Man Cheong
- Cancer and Ageing Research Program, Centre for Genomics and Personalised Health, Queensland University of Technology (QUT), Translational Research Institute (TRI), 37 Kent Street, Woolloongabba, Brisbane, Australia
| | - Keyur Dave
- Cancer and Ageing Research Program, Centre for Genomics and Personalised Health, Queensland University of Technology (QUT), Translational Research Institute (TRI), 37 Kent Street, Woolloongabba, Brisbane, Australia
| | - Maddison Rose
- Cancer and Ageing Research Program, Centre for Genomics and Personalised Health, Queensland University of Technology (QUT), Translational Research Institute (TRI), 37 Kent Street, Woolloongabba, Brisbane, Australia
| | - Mark N Adams
- Cancer and Ageing Research Program, Centre for Genomics and Personalised Health, Queensland University of Technology (QUT), Translational Research Institute (TRI), 37 Kent Street, Woolloongabba, Brisbane, Australia
| | - Kenneth J O'Byrne
- Cancer and Ageing Research Program, Centre for Genomics and Personalised Health, Queensland University of Technology (QUT), Translational Research Institute (TRI), 37 Kent Street, Woolloongabba, Brisbane, Australia
- Princess Alexandra Hospital, Ipswich Road, Woolloongabba, Brisbane, QLD, 4102, Australia
| | - Derek J Richard
- Cancer and Ageing Research Program, Centre for Genomics and Personalised Health, Queensland University of Technology (QUT), Translational Research Institute (TRI), 37 Kent Street, Woolloongabba, Brisbane, Australia.
| | - Emma Bolderson
- Cancer and Ageing Research Program, Centre for Genomics and Personalised Health, Queensland University of Technology (QUT), Translational Research Institute (TRI), 37 Kent Street, Woolloongabba, Brisbane, Australia.
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20
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Head PE, Kapoor-Vazirani P, Nagaraju GP, Zhang H, Rath S, Luong N, Haji-Seyed-Javadi R, Sesay F, Wang SY, Duong D, Daddacha W, Minten E, Song B, Danelia D, Liu X, Li S, Ortlund E, Seyfried N, Smalley D, Wang Y, Deng X, Dynan W, El-Rayes B, Davis A, Yu D. DNA-PK is activated by SIRT2 deacetylation to promote DNA double-strand break repair by non-homologous end joining. Nucleic Acids Res 2023; 51:7972-7987. [PMID: 37395399 PMCID: PMC10450170 DOI: 10.1093/nar/gkad549] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 06/02/2023] [Accepted: 06/27/2023] [Indexed: 07/04/2023] Open
Abstract
DNA-dependent protein kinase (DNA-PK) plays a critical role in non-homologous end joining (NHEJ), the predominant pathway that repairs DNA double-strand breaks (DSB) in response to ionizing radiation (IR) to govern genome integrity. The interaction of the catalytic subunit of DNA-PK (DNA-PKcs) with the Ku70/Ku80 heterodimer on DSBs leads to DNA-PK activation; however, it is not known if upstream signaling events govern this activation. Here, we reveal a regulatory step governing DNA-PK activation by SIRT2 deacetylation, which facilitates DNA-PKcs localization to DSBs and interaction with Ku, thereby promoting DSB repair by NHEJ. SIRT2 deacetylase activity governs cellular resistance to DSB-inducing agents and promotes NHEJ. SIRT2 furthermore interacts with and deacetylates DNA-PKcs in response to IR. SIRT2 deacetylase activity facilitates DNA-PKcs interaction with Ku and localization to DSBs and promotes DNA-PK activation and phosphorylation of downstream NHEJ substrates. Moreover, targeting SIRT2 with AGK2, a SIRT2-specific inhibitor, augments the efficacy of IR in cancer cells and tumors. Our findings define a regulatory step for DNA-PK activation by SIRT2-mediated deacetylation, elucidating a critical upstream signaling event initiating the repair of DSBs by NHEJ. Furthermore, our data suggest that SIRT2 inhibition may be a promising rationale-driven therapeutic strategy for increasing the effectiveness of radiation therapy.
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Affiliation(s)
- PamelaSara E Head
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
| | - Priya Kapoor-Vazirani
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
| | - Ganji P Nagaraju
- School of Medicine, Division of Hematology and Medical Oncology, University of Alabama, Birmingham, AL 35233, USA
| | - Hui Zhang
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
| | - Sandip K Rath
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
| | - Nho C Luong
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
| | - Ramona Haji-Seyed-Javadi
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
| | - Fatmata Sesay
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
| | - Shi-Ya Wang
- Department of Radiation Oncology, UT Southwestern Medical School, Dallas, TX 75390, USA
| | - Duc M Duong
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Waaqo Daddacha
- Department of Biochemistry and Molecular Biology, Augusta University, Augusta, GA 30912, USA
| | - Elizabeth V Minten
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
| | - Boying Song
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
| | - Diana Danelia
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
| | - Xu Liu
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Shuyi Li
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Eric A Ortlund
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Nicholas T Seyfried
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - David M Smalley
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Ya Wang
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
| | - Xingming Deng
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
| | - William S Dynan
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Bassel El-Rayes
- School of Medicine, Division of Hematology and Medical Oncology, University of Alabama, Birmingham, AL 35233, USA
| | - Anthony J Davis
- Department of Radiation Oncology, UT Southwestern Medical School, Dallas, TX 75390, USA
| | - David S Yu
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
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21
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Lu H, Zhang Q, Laverty DJ, Puncheon AC, Augustine M, Williams G, Nagel Z, Chen BC, Davis A. ATM phosphorylates the FATC domain of DNA-PKcs at threonine 4102 to promote non-homologous end joining. Nucleic Acids Res 2023; 51:6770-6783. [PMID: 37309889 PMCID: PMC10359628 DOI: 10.1093/nar/gkad505] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 05/26/2023] [Accepted: 05/31/2023] [Indexed: 06/14/2023] Open
Abstract
Ataxia-telangiectasia mutated (ATM) drives the DNA damage response via modulation of multiple signal transduction and DNA repair pathways. Previously, ATM activity was implicated in promoting the non-homologous end joining (NHEJ) pathway to repair a subset of DNA double-stranded breaks (DSBs), but how ATM performs this function is still unclear. In this study, we identified that ATM phosphorylates the DNA-dependent protein kinase catalytic subunit (DNA-PKcs), a core NHEJ factor, at its extreme C-terminus at threonine 4102 (T4102) in response to DSBs. Ablating phosphorylation at T4102 attenuates DNA-PKcs kinase activity and this destabilizes the interaction between DNA-PKcs and the Ku-DNA complex, resulting in decreased assembly and stabilization of the NHEJ machinery at DSBs. Phosphorylation at T4102 promotes NHEJ, radioresistance, and increases genomic stability following DSB induction. Collectively, these findings establish a key role for ATM in NHEJ-dependent repair of DSBs through positive regulation of DNA-PKcs.
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Affiliation(s)
- Huiming Lu
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX75390, USA
| | - Qin Zhang
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX75390, USA
| | - Daniel J Laverty
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA02115, USA
| | - Andrew C Puncheon
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX75390, USA
| | - Mathew M Augustine
- Division of Surgical Oncology, Department of Surgery, UT Southwestern Medical Center, Dallas, TX75390, USA
- Department of Surgery, North Texas VA Medical Center, Dallas, TX75216, USA
| | - Gareth J Williams
- Department of Biochemistry and Molecular Biology, Robson DNA Science Centre, Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Zachary D Nagel
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA02115, USA
| | - Benjamin P C Chen
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX75390, USA
| | - Anthony J Davis
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX75390, USA
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22
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Wu Y, Song Y, Wang R, Wang T. Molecular mechanisms of tumor resistance to radiotherapy. Mol Cancer 2023; 22:96. [PMID: 37322433 PMCID: PMC10268375 DOI: 10.1186/s12943-023-01801-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 06/03/2023] [Indexed: 06/17/2023] Open
Abstract
BACKGROUND Cancer is the most prevalent cause of death globally, and radiotherapy is considered the standard of care for most solid tumors, including lung, breast, esophageal, and colorectal cancers and glioblastoma. Resistance to radiation can lead to local treatment failure and even cancer recurrence. MAIN BODY In this review, we have extensively discussed several crucial aspects that cause resistance of cancer to radiation therapy, including radiation-induced DNA damage repair, cell cycle arrest, apoptosis escape, abundance of cancer stem cells, modification of cancer cells and their microenvironment, presence of exosomal and non-coding RNA, metabolic reprogramming, and ferroptosis. We aim to focus on the molecular mechanisms of cancer radiotherapy resistance in relation to these aspects and to discuss possible targets to improve treatment outcomes. CONCLUSIONS Studying the molecular mechanisms responsible for radiotherapy resistance and its interactions with the tumor environment will help improve cancer responses to radiotherapy. Our review provides a foundation to identify and overcome the obstacles to effective radiotherapy.
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Affiliation(s)
- Yu Wu
- Department of Radiotherapy, Cancer Hospital of China Medical University, Liaoning Cancer Hospital & Institute, Cancer Hospital of Dalian University of Technology, No.44 Xiaoheyan Road, Dadong District, Shenyang, 110042 Liaoning Province China
- School of Graduate, Dalian Medical University, Dalian, 116044 China
| | - Yingqiu Song
- Department of Radiotherapy, Cancer Hospital of China Medical University, Liaoning Cancer Hospital & Institute, Cancer Hospital of Dalian University of Technology, No.44 Xiaoheyan Road, Dadong District, Shenyang, 110042 Liaoning Province China
| | - Runze Wang
- Department of Radiotherapy, Cancer Hospital of China Medical University, Liaoning Cancer Hospital & Institute, Cancer Hospital of Dalian University of Technology, No.44 Xiaoheyan Road, Dadong District, Shenyang, 110042 Liaoning Province China
- School of Graduate, Dalian Medical University, Dalian, 116044 China
| | - Tianlu Wang
- Department of Radiotherapy, Cancer Hospital of China Medical University, Liaoning Cancer Hospital & Institute, Cancer Hospital of Dalian University of Technology, No.44 Xiaoheyan Road, Dadong District, Shenyang, 110042 Liaoning Province China
- Faculty of Medicine, Dalian University of Technology, Dalian, 116024 China
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23
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Seif-El-Dahan M, Kefala-Stavridi A, Frit P, Hardwick SW, Chirgadze DY, Maia De Oliviera T, Britton S, Barboule N, Bossaert M, Pandurangan AP, Meek K, Blundell TL, Ropars V, Calsou P, Charbonnier JB, Chaplin AK. PAXX binding to the NHEJ machinery explains functional redundancy with XLF. SCIENCE ADVANCES 2023; 9:eadg2834. [PMID: 37256950 PMCID: PMC10413649 DOI: 10.1126/sciadv.adg2834] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 04/03/2023] [Indexed: 06/02/2023]
Abstract
Nonhomologous end joining is a critical mechanism that repairs DNA double-strand breaks in human cells. In this work, we address the structural and functional role of the accessory protein PAXX [paralog of x-ray repair cross-complementing protein 4 (XRCC4) and XRCC4-like factor (XLF)] in this mechanism. Here, we report high-resolution cryo-electron microscopy (cryo-EM) and x-ray crystallography structures of the PAXX C-terminal Ku-binding motif bound to Ku70/80 and cryo-EM structures of PAXX bound to two alternate DNA-dependent protein kinase (DNA-PK) end-bridging dimers, mediated by either Ku80 or XLF. We identify residues critical for the Ku70/PAXX interaction in vitro and in cells. We demonstrate that PAXX and XLF can bind simultaneously to the Ku heterodimer and act as structural bridges in alternate forms of DNA-PK dimers. Last, we show that engagement of both proteins provides a complementary advantage for DNA end synapsis and end joining in cells.
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Affiliation(s)
- Murielle Seif-El-Dahan
- Institute for Integrative Biology of the Cell (I2BC), Institute Joliot, CEA, CNRS, Université Paris-Saclay, 91198 Gif-sur-Yvette cedex, France
| | - Antonia Kefala-Stavridi
- Department of Biochemistry, University of Cambridge, Sanger Building, Tennis Court Road, Cambridge CB2 1GA, UK
| | - Philippe Frit
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Steven W. Hardwick
- Cryo-EM Facility, Department of Biochemistry, University of Cambridge, Sanger Building, Tennis Court Road, Cambridge CB2 1GA, UK
| | - Dima Y. Chirgadze
- Cryo-EM Facility, Department of Biochemistry, University of Cambridge, Sanger Building, Tennis Court Road, Cambridge CB2 1GA, UK
| | | | - Sébastien Britton
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Nadia Barboule
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Madeleine Bossaert
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Arun Prasad Pandurangan
- Department of Biochemistry, University of Cambridge, Sanger Building, Tennis Court Road, Cambridge CB2 1GA, UK
| | - Katheryn Meek
- College of Veterinary Medicine, Department of Microbiology & Molecular Genetics, Department of Pathobiology and Diagnostic Investigation, Michigan State University, East Lansing, MI 48824, USA
| | - Tom L. Blundell
- Department of Biochemistry, University of Cambridge, Sanger Building, Tennis Court Road, Cambridge CB2 1GA, UK
| | - Virginie Ropars
- Institute for Integrative Biology of the Cell (I2BC), Institute Joliot, CEA, CNRS, Université Paris-Saclay, 91198 Gif-sur-Yvette cedex, France
| | - Patrick Calsou
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Jean-Baptiste Charbonnier
- Institute for Integrative Biology of the Cell (I2BC), Institute Joliot, CEA, CNRS, Université Paris-Saclay, 91198 Gif-sur-Yvette cedex, France
| | - Amanda K. Chaplin
- Leicester Institute for Structural and Chemical Biology, Department of Molecular and Cell Biology, University of Leicester, Leicester, UK
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24
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Chen W, Chiang J, Shang Z, Palchik G, Newman C, Zhang Y, Davis AJ, Lee H, Chen BPC. DNA-PKcs and ATM modulate mitochondrial ADP-ATP exchange as an oxidative stress checkpoint mechanism. EMBO J 2023; 42:e112094. [PMID: 36727301 PMCID: PMC10015379 DOI: 10.15252/embj.2022112094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 01/13/2023] [Accepted: 01/21/2023] [Indexed: 02/03/2023] Open
Abstract
DNA-PKcs is a key regulator of DNA double-strand break repair. Apart from its canonical role in the DNA damage response, DNA-PKcs is involved in the cellular response to oxidative stress (OS), but its exact role remains unclear. Here, we report that DNA-PKcs-deficient human cells display depolarized mitochondria membrane potential (MMP) and reoriented metabolism, supporting a role for DNA-PKcs in oxidative phosphorylation (OXPHOS). DNA-PKcs directly interacts with mitochondria proteins ANT2 and VDAC2, and formation of the DNA-PKcs/ANT2/VDAC2 (DAV) complex supports optimal exchange of ADP and ATP across mitochondrial membranes to energize the cell via OXPHOS and to maintain MMP. Moreover, we demonstrate that the DAV complex temporarily dissociates in response to oxidative stress to attenuate ADP-ATP exchange, a rate-limiting step for OXPHOS. Finally, we found that dissociation of the DAV complex is mediated by phosphorylation of DNA-PKcs at its Thr2609 cluster by ATM kinase. Based on these findings, we propose that the coordination between the DAV complex and ATM serves as a novel oxidative stress checkpoint to decrease ROS production from mitochondrial OXPHOS and to hasten cellular recovery from OS.
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Affiliation(s)
- Wei‐Min Chen
- Division of Molecular Radiation Biology, Department of Radiation OncologyUniversity of Texas Southwestern Medical Center at DallasDallasTXUSA
- Department of Life ScienceNational Taiwan UniversityTaipeiTaiwan
| | - Jui‐Chung Chiang
- Division of Molecular Radiation Biology, Department of Radiation OncologyUniversity of Texas Southwestern Medical Center at DallasDallasTXUSA
- Department of Life ScienceNational Taiwan UniversityTaipeiTaiwan
| | - Zengfu Shang
- Division of Molecular Radiation Biology, Department of Radiation OncologyUniversity of Texas Southwestern Medical Center at DallasDallasTXUSA
| | - Guillermo Palchik
- Division of Molecular Radiation Biology, Department of Radiation OncologyUniversity of Texas Southwestern Medical Center at DallasDallasTXUSA
| | - Ciara Newman
- Division of Molecular Radiation Biology, Department of Radiation OncologyUniversity of Texas Southwestern Medical Center at DallasDallasTXUSA
| | - Yuanyuan Zhang
- Division of Molecular Radiation Biology, Department of Radiation OncologyUniversity of Texas Southwestern Medical Center at DallasDallasTXUSA
| | - Anthony J Davis
- Division of Molecular Radiation Biology, Department of Radiation OncologyUniversity of Texas Southwestern Medical Center at DallasDallasTXUSA
| | - Hsinyu Lee
- Department of Life ScienceNational Taiwan UniversityTaipeiTaiwan
| | - Benjamin PC Chen
- Division of Molecular Radiation Biology, Department of Radiation OncologyUniversity of Texas Southwestern Medical Center at DallasDallasTXUSA
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25
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Lu H, Zhang Q, Laverty DJ, Puncheon AC, Williams GJ, Nagel ZD, Chen BP, Davis AJ. ATM phosphorylates the FATC domain of DNA-PK cs at threonine 4102 to promote non-homologous end joining. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.02.526879. [PMID: 36778257 PMCID: PMC9915669 DOI: 10.1101/2023.02.02.526879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Ataxia-telangiectasia mutated (ATM) drives the DNA damage response via modulation of multiple signal transduction and DNA repair pathways. Previously, ATM activity was implicated in promoting the non-homologous end joining (NHEJ) pathway to repair a subset of DNA double strand breaks (DSBs), but how ATM performs this function is still unclear. In this study, we identified that ATM phosphorylates the DNA-dependent protein kinase catalytic subunit (DNA-PK cs ), a core NHEJ factor, at its extreme C-terminus at threonine 4102 (T4102) in response to DSBs. Phosphorylation at T4102 stabilizes the interaction between DNA-PK cs and the Ku-DNA complex and promotes assembly and stabilization of the NHEJ machinery at DSBs. Ablating phosphorylation at this site results in decreased NHEJ, radiosensitivity, and increased radiation-induced genomic instability. Collectively, these findings establish a key role for ATM in NHEJ-dependent repair of DSBs through positive regulation of DNA-PK cs .
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26
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Novotny JP, Mariño-Enríquez A, Fletcher JA. Targeting DNA-PK. Cancer Treat Res 2023; 186:299-312. [PMID: 37978142 DOI: 10.1007/978-3-031-30065-3_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
This chapter explores the multifaceted roles of DNA-PK with particular focus on its functions in non-homologous end-joining (NHEJ) DNA repair. DNA-PK is the primary orchestrator of NHEJ but also regulates other biologic processes. The growing understanding of varied DNA-PK biologic roles highlights new avenues for cancer treatment. However, these multiple roles also imply challenges, particularly in combination therapies, with perhaps a higher risk of clinical toxicities than was previously envisioned. These considerations underscore the need for compelling and innovative strategies to accomplish effective clinical translation.
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27
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DNA Damage Response in Cancer Therapy and Resistance: Challenges and Opportunities. Int J Mol Sci 2022; 23:ijms232314672. [PMID: 36499000 PMCID: PMC9735783 DOI: 10.3390/ijms232314672] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/20/2022] [Accepted: 11/21/2022] [Indexed: 11/25/2022] Open
Abstract
Resistance to chemo- and radiotherapy is a common event among cancer patients and a reason why new cancer therapies and therapeutic strategies need to be in continuous investigation and development. DNA damage response (DDR) comprises several pathways that eliminate DNA damage to maintain genomic stability and integrity, but different types of cancers are associated with DDR machinery defects. Many improvements have been made in recent years, providing several drugs and therapeutic strategies for cancer patients, including those targeting the DDR pathways. Currently, poly (ADP-ribose) polymerase inhibitors (PARP inhibitors) are the DDR inhibitors (DDRi) approved for several cancers, including breast, ovarian, pancreatic, and prostate cancer. However, PARPi resistance is a growing issue in clinical settings that increases disease relapse and aggravate patients' prognosis. Additionally, resistance to other DDRi is also being found and investigated. The resistance mechanisms to DDRi include reversion mutations, epigenetic modification, stabilization of the replication fork, and increased drug efflux. This review highlights the DDR pathways in cancer therapy, its role in the resistance to conventional treatments, and its exploitation for anticancer treatment. Biomarkers of treatment response, combination strategies with other anticancer agents, resistance mechanisms, and liabilities of treatment with DDR inhibitors are also discussed.
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28
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The Role of DNA Damage and Repair in Idiopathic Pulmonary Fibrosis. Antioxidants (Basel) 2022; 11:antiox11112292. [PMID: 36421478 PMCID: PMC9687113 DOI: 10.3390/antiox11112292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/11/2022] [Accepted: 11/17/2022] [Indexed: 11/22/2022] Open
Abstract
The mortality rate of idiopathic pulmonary fibrosis (IPF) increases yearly due to ineffective treatment. Given that the lung is exposed to the external environment, it is likely that oxidative stress, especially the stimulation of DNA, would be of particular importance in pulmonary fibrosis. DNA damage is known to play an important role in idiopathic pulmonary fibrosis initiation, so DNA repair systems targeting damage are also crucial for the survival of lung cells. Although many contemporary reports have summarized the role of individual DNA damage and repair pathways in their hypotheses, they have not focused on idiopathic pulmonary fibrosis. This review, therefore, aims to provide a concise overview for researchers to understand the pathways of DNA damage and repair and their roles in IPF.
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29
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Wilson C, Murnane JP. High-throughput screen to identify compounds that prevent or target telomere loss in human cancer cells. NAR Cancer 2022; 4:zcac029. [PMID: 36196242 PMCID: PMC9527662 DOI: 10.1093/narcan/zcac029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 09/09/2022] [Accepted: 09/29/2022] [Indexed: 11/14/2022] Open
Abstract
Chromosome instability (CIN) is an early step in carcinogenesis that promotes tumor cell progression and resistance to therapy. Using plasmids integrated adjacent to telomeres, we have previously demonstrated that the sensitivity of subtelomeric regions to DNA double-strand breaks (DSBs) contributes to telomere loss and CIN in cancer. A high-throughput screen was created to identify compounds that affect telomere loss due to subtelomeric DSBs introduced by I-SceI endonuclease, as detected by cells expressing green fluorescent protein (GFP). A screen of a library of 1832 biologically-active compounds identified a variety of compounds that increase or decrease the number of GFP-positive cells following activation of I-SceI. A curated screen done in triplicate at various concentrations found that inhibition of classical nonhomologous end joining (C-NHEJ) increased DSB-induced telomere loss, demonstrating that C-NHEJ is functional in subtelomeric regions. Compounds that decreased DSB-induced telomere loss included inhibitors of mTOR, p38 and tankyrase, consistent with our earlier hypothesis that the sensitivity of subtelomeric regions to DSBs is a result of inappropriate resection during repair. Although this assay was also designed to identify compounds that selectively target cells experiencing telomere loss and/or chromosome instability, no compounds of this type were identified in the current screen.
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Affiliation(s)
- Chris Wilson
- Department of Pharmaceutical Chemistry, Small Molecule Discovery Center, University of California, San Francisco, CA 94143, USA
| | - John P Murnane
- To whom correspondence should be addressed. Tel: +1 415 680 4434;
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30
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Pozas J, Alonso-Gordoa T, Román MS, Santoni M, Thirlwell C, Grande E, Molina-Cerrillo J. Novel therapeutic approaches in GEP-NETs based on genetic and epigenetic alterations. Biochim Biophys Acta Rev Cancer 2022; 1877:188804. [PMID: 36152904 DOI: 10.1016/j.bbcan.2022.188804] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 09/17/2022] [Accepted: 09/17/2022] [Indexed: 11/17/2022]
Abstract
Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are heterogeneous malignancies with distinct prognosis based on primary tumor localization, grade, stage and functionality. Surgery remains the only curative option in localized tumors, but systemic therapy is the mainstay of treatment for patients with advanced disease. For decades, the therapeutic landscape of GEP-NETs was limited to chemotherapy regimens with low response rates. The arrival of novel agents such as somatostatin analogues, peptide receptor radionuclide therapy, tyrosine kinase inhibitors or mTOR-targeted drugs, has changed the therapeutic paradigm of GEP-NETs. However, the efficacy of these agents is limited in time and there is scarce knowledge of optimal treatment sequencing. In recent years, massive parallel sequencing techniques have started to unravel the genomic intricacies of these tumors, allowing us to better understand the mechanisms of resistance to current treatments and to develop new targeted agents that will hopefully start an era for personalized treatment in NETs. In this review we aim to summarize the most relevant genomic aberrations and signaling pathways underlying GEP-NET tumorigenesis and potential therapeutic strategies derived from them.
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Affiliation(s)
- Javier Pozas
- Medical Oncology Department, Hospital Universitario Ramón y Cajal, Medicine School, Alcalá University, Madrid, Spain
| | - Teresa Alonso-Gordoa
- Medical Oncology Department, Hospital Universitario Ramón y Cajal, Medicine School, Alcalá University, Madrid, Spain
| | - Maria San Román
- Medical Oncology Department, Hospital Universitario Ramón y Cajal, Medicine School, Alcalá University, Madrid, Spain
| | | | | | - Enrique Grande
- Medical Oncology Ddepartment. MD Anderson Cancer Center Madrid, 28033 Madrid, Spain
| | - Javier Molina-Cerrillo
- Medical Oncology Department, Hospital Universitario Ramón y Cajal, Medicine School, Alcalá University, Madrid, Spain.
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31
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Nickoloff JA. Targeting Replication Stress Response Pathways to Enhance Genotoxic Chemo- and Radiotherapy. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27154736. [PMID: 35897913 PMCID: PMC9330692 DOI: 10.3390/molecules27154736] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 07/20/2022] [Accepted: 07/22/2022] [Indexed: 12/12/2022]
Abstract
Proliferating cells regularly experience replication stress caused by spontaneous DNA damage that results from endogenous reactive oxygen species (ROS), DNA sequences that can assume secondary and tertiary structures, and collisions between opposing transcription and replication machineries. Cancer cells face additional replication stress, including oncogenic stress that results from the dysregulation of fork progression and origin firing, and from DNA damage induced by radiotherapy and most cancer chemotherapeutic agents. Cells respond to such stress by activating a complex network of sensor, signaling and effector pathways that protect genome integrity. These responses include slowing or stopping active replication forks, protecting stalled replication forks from collapse, preventing late origin replication firing, stimulating DNA repair pathways that promote the repair and restart of stalled or collapsed replication forks, and activating dormant origins to rescue adjacent stressed forks. Currently, most cancer patients are treated with genotoxic chemotherapeutics and/or ionizing radiation, and cancer cells can gain resistance to the resulting replication stress by activating pro-survival replication stress pathways. Thus, there has been substantial effort to develop small molecule inhibitors of key replication stress proteins to enhance tumor cell killing by these agents. Replication stress targets include ATR, the master kinase that regulates both normal replication and replication stress responses; the downstream signaling kinase Chk1; nucleases that process stressed replication forks (MUS81, EEPD1, Metnase); the homologous recombination catalyst RAD51; and other factors including ATM, DNA-PKcs, and PARP1. This review provides an overview of replication stress response pathways and discusses recent pre-clinical studies and clinical trials aimed at improving cancer therapy by targeting replication stress response factors.
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Affiliation(s)
- Jac A Nickoloff
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523, USA
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32
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Xiao H, Li F, Mladenov E, Soni A, Mladenova V, Pan B, Dueva R, Stuschke M, Timmermann B, Iliakis G. Increased Resection at DSBs in G2-Phase Is a Unique Phenotype Associated with DNA-PKcs Defects That Is Not Shared by Other Factors of c-NHEJ. Cells 2022; 11:cells11132099. [PMID: 35805183 PMCID: PMC9265841 DOI: 10.3390/cells11132099] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 06/28/2022] [Accepted: 06/30/2022] [Indexed: 01/27/2023] Open
Abstract
The load of DNA double-strand breaks (DSBs) induced in the genome of higher eukaryotes by different doses of ionizing radiation (IR) is a key determinant of DSB repair pathway choice, with homologous recombination (HR) and ATR substantially gaining ground at doses below 0.5 Gy. Increased resection and HR engagement with decreasing DSB-load generate a conundrum in a classical non-homologous end-joining (c-NHEJ)-dominated cell and suggest a mechanism adaptively facilitating resection. We report that ablation of DNA-PKcs causes hyper-resection, implicating DNA-PK in the underpinning mechanism. However, hyper-resection in DNA-PKcs-deficient cells can also be an indirect consequence of their c-NHEJ defect. Here, we report that all tested DNA-PKcs mutants show hyper-resection, while mutants with defects in all other factors of c-NHEJ fail to do so. This result rules out the model of c-NHEJ versus HR competition and the passive shift from c-NHEJ to HR as the causes of the increased resection and suggests the integration of DNA-PKcs into resection regulation. We develop a model, compatible with the results of others, which integrates DNA-PKcs into resection regulation and HR for a subset of DSBs. For these DSBs, we propose that the kinase remains at the break site, rather than the commonly assumed autophosphorylation-mediated removal from DNA ends.
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Affiliation(s)
- Huaping Xiao
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany; (H.X.); (F.L.); (E.M.); (A.S.); (V.M.); (B.P.); (R.D.)
- Division of Experimental Radiation Biology, Department of Radiation Therapy, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany;
| | - Fanghua Li
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany; (H.X.); (F.L.); (E.M.); (A.S.); (V.M.); (B.P.); (R.D.)
- Department of Particle Therapy, University Hospital Essen, West German Proton Therapy Centre Essen (WPE), West German Cancer Center (WTZ), German Cancer Consortium (DKTK), 45147 Essen, Germany;
| | - Emil Mladenov
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany; (H.X.); (F.L.); (E.M.); (A.S.); (V.M.); (B.P.); (R.D.)
- Division of Experimental Radiation Biology, Department of Radiation Therapy, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany;
| | - Aashish Soni
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany; (H.X.); (F.L.); (E.M.); (A.S.); (V.M.); (B.P.); (R.D.)
- Division of Experimental Radiation Biology, Department of Radiation Therapy, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany;
| | - Veronika Mladenova
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany; (H.X.); (F.L.); (E.M.); (A.S.); (V.M.); (B.P.); (R.D.)
- Division of Experimental Radiation Biology, Department of Radiation Therapy, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany;
| | - Bing Pan
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany; (H.X.); (F.L.); (E.M.); (A.S.); (V.M.); (B.P.); (R.D.)
- Division of Experimental Radiation Biology, Department of Radiation Therapy, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany;
| | - Rositsa Dueva
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany; (H.X.); (F.L.); (E.M.); (A.S.); (V.M.); (B.P.); (R.D.)
- Institute of Physiology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
| | - Martin Stuschke
- Division of Experimental Radiation Biology, Department of Radiation Therapy, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany;
- German Cancer Consortium (DKTK), Partner Site University Hospital Essen, German Cancer Research Center (DKFZ), 45147 Essen, Germany
| | - Beate Timmermann
- Department of Particle Therapy, University Hospital Essen, West German Proton Therapy Centre Essen (WPE), West German Cancer Center (WTZ), German Cancer Consortium (DKTK), 45147 Essen, Germany;
- German Cancer Consortium (DKTK), Partner Site University Hospital Essen, German Cancer Research Center (DKFZ), 45147 Essen, Germany
| | - George Iliakis
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany; (H.X.); (F.L.); (E.M.); (A.S.); (V.M.); (B.P.); (R.D.)
- Division of Experimental Radiation Biology, Department of Radiation Therapy, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany;
- Correspondence: ; Tel.: +49-201-723-4152
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Bovine Pancreatic RNase A: An Insight into the Mechanism of Antitumor Activity In Vitro and In Vivo. Pharmaceutics 2022; 14:pharmaceutics14061173. [PMID: 35745743 PMCID: PMC9229056 DOI: 10.3390/pharmaceutics14061173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 05/23/2022] [Accepted: 05/27/2022] [Indexed: 12/04/2022] Open
Abstract
In this investigation, we extensively studied the mechanism of antitumor activity of bovine pancreatic RNase A. Using confocal microscopy, we show that after RNase A penetration into HeLa and B16 cells, a part of the enzyme remains unbound with the ribonuclease inhibitor (RI), resulting in the decrease in cytosolic RNAs in both types of cells and rRNAs in the nucleoli of HeLa cells. Molecular docking indicates the ability of RNase A to form a complex with Ku70/Ku80 heterodimer, and microscopy data confirm its localization mostly inside the nucleus, which may underlie the mechanism of RNase A penetration into cells and its intracellular traffic. RNase A reduced migration and invasion of tumor cells in vitro. In vivo, in the metastatic model of melanoma, RNase A suppressed metastases in the lungs and changed the expression of EMT markers in the tissue adjacent to metastatic foci; this increased Cdh1 and decreased Tjp1, Fn and Vim, disrupting the favorable tumor microenvironment. A similar pattern was observed for all genes except for Fn in metastatic foci, indicating a decrease in the invasive potential of tumor cells. Bioinformatic analysis of RNase-A-susceptible miRNAs and their regulatory networks showed that the main processes modulated by RNase A in the tumor microenvironment are the regulation of cell adhesion and junction, cell cycle regulation and pathways associated with EMT and tumor progression.
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Carr MI, Chiu LY, Guo Y, Xu C, Lazorchak AS, Yu H, Qin G, Qi J, Marelli B, Lan Y, Sun Q, Czauderna F, Zenke FT, Blaukat A, Vassilev LT. DNA-PK Inhibitor Peposertib Amplifies Radiation-Induced Inflammatory Micronucleation and Enhances TGFβ/PD-L1 Targeted Cancer Immunotherapy. Mol Cancer Res 2022; 20:568-582. [PMID: 34980594 PMCID: PMC9381110 DOI: 10.1158/1541-7786.mcr-21-0612] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 11/09/2021] [Accepted: 12/21/2021] [Indexed: 01/07/2023]
Abstract
Radiotherapy is the most widely used cancer treatment and improvements in its efficacy and safety are highly sought-after. Peposertib (also known as M3814), a potent and selective DNA-dependent protein kinase (DNA-PK) inhibitor, effectively suppresses the repair of radiation-induced DNA double-strand breaks (DSB) and regresses human xenograft tumors in preclinical models. Irradiated cancer cells devoid of p53 activity are especially sensitive to the DNA-PK inhibitor, as they lose a key cell-cycle checkpoint circuit and enter mitosis with unrepaired DSBs, leading to catastrophic consequences. Here, we show that inhibiting the repair of DSBs induced by ionizing radiation with peposertib offers a powerful new way for improving radiotherapy by simultaneously enhancing cancer cell killing and response to a bifunctional TGFβ "trap"/anti-PD-L1 cancer immunotherapy. By promoting chromosome misalignment and missegregation in p53-deficient cancer cells with unrepaired DSBs, DNA-PK inhibitor accelerated micronuclei formation, a key generator of cytosolic DNA and activator of cGAS/STING-dependent inflammatory signaling as it elevated PD-L1 expression in irradiated cancer cells. Triple combination of radiation, peposertib, and bintrafusp alfa, a fusion protein simultaneously inhibiting the profibrotic TGFβ and immunosuppressive PD-L1 pathways was superior to dual combinations and suggested a novel approach to more efficacious radioimmunotherapy of cancer. IMPLICATIONS Selective inhibition of DNA-PK in irradiated cancer cells enhances inflammatory signaling and activity of dual TGFβ/PD-L1 targeted therapy and may offer a more efficacious combination option for the treatment of locally advanced solid tumors.
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Affiliation(s)
- Michael I. Carr
- Translational Innovation Platform Oncology and Immuno-Oncology, EMD Serono Research & Development Institute, Inc., Billerica, Massachusetts
| | - Li-Ya Chiu
- Translational Innovation Platform Oncology and Immuno-Oncology, EMD Serono Research & Development Institute, Inc., Billerica, Massachusetts
| | - Yige Guo
- Translational Innovation Platform Oncology and Immuno-Oncology, EMD Serono Research & Development Institute, Inc., Billerica, Massachusetts
| | - Chunxiao Xu
- Translational Innovation Platform Oncology and Immuno-Oncology, EMD Serono Research & Development Institute, Inc., Billerica, Massachusetts
| | - Adam S. Lazorchak
- Translational Innovation Platform Oncology and Immuno-Oncology, EMD Serono Research & Development Institute, Inc., Billerica, Massachusetts
| | - Huakui Yu
- Translational Innovation Platform Oncology and Immuno-Oncology, EMD Serono Research & Development Institute, Inc., Billerica, Massachusetts
| | - Guozhong Qin
- Translational Innovation Platform Oncology and Immuno-Oncology, EMD Serono Research & Development Institute, Inc., Billerica, Massachusetts
| | - Jin Qi
- Translational Innovation Platform Oncology and Immuno-Oncology, EMD Serono Research & Development Institute, Inc., Billerica, Massachusetts
| | - Bo Marelli
- Translational Innovation Platform Oncology and Immuno-Oncology, EMD Serono Research & Development Institute, Inc., Billerica, Massachusetts
| | - Yan Lan
- Translational Innovation Platform Oncology and Immuno-Oncology, EMD Serono Research & Development Institute, Inc., Billerica, Massachusetts
| | - Qing Sun
- Translational Innovation Platform Oncology and Immuno-Oncology, EMD Serono Research & Development Institute, Inc., Billerica, Massachusetts
| | - Frank Czauderna
- Translational Innovation Platform Oncology and Immuno-Oncology, EMD Serono Research & Development Institute, Inc., Billerica, Massachusetts
| | - Frank T. Zenke
- Translational Innovation Platform Oncology and Immuno-Oncology, Merck KGaA, Darmstadt, Germany
| | - Andree Blaukat
- Translational Innovation Platform Oncology and Immuno-Oncology, Merck KGaA, Darmstadt, Germany
| | - Lyubomir T. Vassilev
- Translational Innovation Platform Oncology and Immuno-Oncology, EMD Serono Research & Development Institute, Inc., Billerica, Massachusetts.,Corresponding Author: Lyubomir T. Vassilev, Translational Innovation Platform Oncology and Immuno-Oncology, EMD Serono Research & Development Institute, Inc., 45A Middlesex Turnpike, Billerica, MA 01821. Phone: 978-294-1115; E-mail:
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35
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Dylgjeri E, Knudsen KE. DNA-PKcs: A Targetable Protumorigenic Protein Kinase. Cancer Res 2022; 82:523-533. [PMID: 34893509 PMCID: PMC9306356 DOI: 10.1158/0008-5472.can-21-1756] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 08/17/2021] [Accepted: 11/10/2021] [Indexed: 01/07/2023]
Abstract
DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is a pleiotropic protein kinase that plays critical roles in cellular processes fundamental to cancer. DNA-PKcs expression and activity are frequently deregulated in multiple hematologic and solid tumors and have been tightly linked to poor outcome. Given the potentially influential role of DNA-PKcs in cancer development and progression, therapeutic targeting of this kinase is being tested in preclinical and clinical settings. This review summarizes the latest advances in the field, providing a comprehensive discussion of DNA-PKcs functions in cancer and an update on the clinical assessment of DNA-PK inhibitors in cancer therapy.
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Affiliation(s)
- Emanuela Dylgjeri
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, Pennsylvania.,Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Karen E. Knudsen
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, Pennsylvania.,Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania.,Department of Medical Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania.,Department of Urology, Thomas Jefferson University, Philadelphia, Pennsylvania.,Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania.,Corresponding Author: Karen E. Knudsen, Thomas Jefferson University, 233 South 10th Street, BLSB 1050, Philadelphia, PA 19107. Phone: 215-503-5692; E-mail:
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Hammarsten O, Lyytikäinen A, Thunström S, Ek T, Fasth A, Ekwall O, Cajander S, Borgström EW, Smith CIE, Johansson P. Clinical measurement of cellular DNA damage hypersensitivity in patients with DNA repair defects. Orphanet J Rare Dis 2022; 17:50. [PMID: 35164800 PMCID: PMC8842932 DOI: 10.1186/s13023-022-02199-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 01/30/2022] [Indexed: 11/18/2022] Open
Abstract
Background DNA repair deficiency disorders are rare inherited diseases arising from pathogenic (disease-causing) variants in genes involved in DNA repair. There are no standardized diagnostic assays for the investigation of pathological significance of unknown variants in DNA repair genes. We hypothesized that our assays for measuring in vitro patient blood cell hypersensitivity to DNA-damaging agents can be used to establish the pathological significance of unknown variants in DNA repair genes. Six patients with variants in the DNA repair genes PRKDC (two siblings), DCLRE1C (two siblings), NBN, and MSH6 were included. Here, we used the cell division assay (CDA) and the γ-H2AX assay, which were both developed and clinically validated by us, to measure patient cell hypersensitivity in response to ionizing radiation, mitomycin C, cytarabine and doxorubicin. Results Radiation hypersensitivity was detected in the two patients with variants in the PRKDC gene (p < 0.0001 for both at 3.5 Gy), and the two patients with DCLRE1C variants (p < 0.0001 at 3.5 Gy for sibling 1 and p < 0.0001 at 1 Gy for sibling 2). The cells from the patients with the PRKDC variant were also deficient in removing γ-H2AX (p < 0.001). The cells from the patient with variants in the NBN gene were hypersensitive to mitomycin C (p = 0.0008) and deficient in both induction and removal of γ-H2AX in response to radiation. Conclusions The combination of the CDA and the γ-H2AX assay is useful in investigating the significance of unknown variants in some DNA repair genes. Supplementary Information The online version contains supplementary material available at 10.1186/s13023-022-02199-8.
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Anastasia A, Dellavedova G, Ramos-Montoya A, James NH, Chiorino G, Russo M, Baakza H, Wilson J, Ghilardi C, Cadogan EB, Giavazzi R, Bani MR. The DNA-PK inhibitor AZD7648 sensitizes patient derived ovarian cancer xenografts to pegylated liposomal doxorubicin and olaparib preventing abdominal metastases. Mol Cancer Ther 2022; 21:555-567. [PMID: 35149547 DOI: 10.1158/1535-7163.mct-21-0420] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 10/21/2021] [Accepted: 02/07/2022] [Indexed: 11/16/2022]
Abstract
Ovarian cancer is the deadliest gynaecological cancer, with a 5 year survival rate of 30%, when the disease has spread throughout the peritoneal cavity. We investigated the efficacy to delay disease progression by the DNA-dependent protein kinase (DNA-PKcs)inhibitor AZD7648, administered in combination with two of the therapeutic options for patient management: either pegylated liposomal doxorubicin (PLD) or the poly(adenosine diphosphate-ribose)polymerase (PARP) inhibitor olaparib. Patient-derived ovarian cancer xenografts (OC-PDXs) were transplanted subcutaneously to evaluate the effect of treatment on tumour growth, or orthotopically in the peritoneal cavity to evaluate the effect on metastatic spread. AZD7648 was administered orally (po)in combination with PLD (dosed intravenously) or with olaparib (po). To prove the inhibition of DNA-PK in the tumours, we measured pDNA-PKcs, pRPA32 and γH2AX, biomarkers of DNA-PK activity. AZD7648 enhanced the therapeutic efficacy of PLD in all the OC-PDXs tested, regardless of their BRCA status, sensitivity to cisplatin or PLD. The treatment caused disease stabilization, that persisted despite therapy discontinuation for tumours growing subcutaneously, and significantly impaired the abdominal metastatic dissemination, prolonging the lifespan of mice implanted orthotopically. AZD7648 potentiated the efficacy of olaparib in BRCA-deficient OC-PDXs, but did not sensitize BRCA-proficient OC-PDXs to olaparib, despite an equivalent inhibition of DNA-PK, suggesting the need of a pre-existing olaparib activity to benefit from the addition of AZD7648. This work suggests that AZD7648, an inhibitor of DNA-PK, dosed in combination with PLD or olaparib is an exciting therapeutic option that could benefit ovarian cancer patients and should be explored in clinical trials.
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Affiliation(s)
- Alessia Anastasia
- Oncology, Institute for Pharmacological Research Mario Negri - IRCCS
| | | | | | - Neil H James
- Bioscience, Oncology, R, AstraZeneca (United Kingdom)
| | | | - Massimo Russo
- Cancer Metastasis Therapeutics, Department of Oncology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy, Cancer Metastasis Therapeutics, Department of Oncology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy
| | | | - Joanne Wilson
- Department of Oncology, AstraZeneca (United Kingdom)
| | - Carmen Ghilardi
- Cancer Metastasis Therapeutics - Oncology Department, Istituto di Ricerche Farmacologiche Mario Negri IRCCS
| | | | - Raffaella Giavazzi
- Cancer Metastasis Therapeutics, Oncology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS
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Hu C, Bugbee T, Dacus D, Palinski R, Wallace N. Beta human papillomavirus 8 E6 allows colocalization of non-homologous end joining and homologous recombination repair factors. PLoS Pathog 2022; 18:e1010275. [PMID: 35148356 PMCID: PMC8836322 DOI: 10.1371/journal.ppat.1010275] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 01/12/2022] [Indexed: 12/30/2022] Open
Abstract
Beta human papillomavirus (β-HPV) are hypothesized to make DNA damage more mutagenic and potentially more carcinogenic. Double strand breaks (DSBs) are the most deleterious DNA lesion. They are typically repaired by homologous recombination (HR) or non-homologous end joining (NHEJ). HR occurs after DNA replication while NHEJ can occur at any point in the cell cycle. HR and NHEJ are not thought to occur in the same cell at the same time. HR is restricted to cells in phases of the cell cycle where homologous templates are available, while NHEJ occurs primarily during G1. β-HPV type 8 protein E6 (8E6) attenuates both repair pathways. We use a series of immunofluorescence microscopy and flow cytometry experiments to better define the impact of this attenuation. We found that 8E6 causes colocalization of HR factors (RPA70 and RAD51) with an NHEJ factor (activated DNA-PKcs or pDNA-PKcs) at persistent DSBs. 8E6 also causes RAD51 foci to form during G1. The initiation of NHEJ and HR at the same lesion could lead to antagonistic DNA end processing. Further, HR cannot be readily completed in an error-free manner during G1. Both aberrant repair events would cause deletions. To determine if these mutations were occurring, we used next generation sequencing of the 200kb surrounding a CAS9-induced DSB. 8E6 caused a 21-fold increase in deletions. Chemical and genetic inhibition of p300 as well as an 8E6 mutant that is incapable of destabilizing p300 demonstrates that 8E6 is acting via p300 destabilization. More specific chemical inhibitors of DNA repair provided mechanistic insight by mimicking 8E6-induced dysregulation of DNA repair in a virus-free system. Specifically, inhibition of NHEJ causes RAD51 foci to form in G1 and colocalization of RAD51 with pDNA-PKcs. Our previous work shows that a master transcription regulator, p300, facilitates two major DNA double strand break (DSB) repair pathways: non-homologous end joining (NHEJ) and homologous recombination (HR). By degrading p300, beta genus human papillomavirus 8 protein E6 (8E6) hinders pDNA-PKcs resolution, an essential step during NHEJ. NHEJ and HR are known to compete, with only one pathway initiating repair of a DSB. NHEJ tends to be used in G1 and HR occurs in S/G2. Here, we show that 8E6 allows NHEJ and HR to initiate at the same break site. We show that 8E6 allows HR to initiate in G1, suggesting that NHEJ starts but fails before HR is initiated at the same DSB. Next generation sequencing of the region surrounding a CAS9-induced DSB supports our hypothesis that this dysregulation of DSB repair is mutagenic as 8E6 caused a 15- to 20-fold increase in mutations associated with a CAS9-induced DSB. These studies support the putative role of HPV8 infections in non-melanoma skin cancer development.
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Affiliation(s)
- Changkun Hu
- Division of Biology, Kansas State University, Manhattan, Kansas, United States of America
| | - Taylor Bugbee
- Division of Biology, Kansas State University, Manhattan, Kansas, United States of America
| | - Dalton Dacus
- Division of Biology, Kansas State University, Manhattan, Kansas, United States of America
| | - Rachel Palinski
- Kansas State Veterinary Diagnostic Laboratory, Kansas State University, Manhattan, Kansas, United States of America
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, Kansas, United States of America
| | - Nicholas Wallace
- Division of Biology, Kansas State University, Manhattan, Kansas, United States of America
- * E-mail:
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Reindl J, Kundrat P, Girst S, Sammer M, Schwarz B, Dollinger G. Dosimetry of heavy ion exposure to human cells using nanoscopic imaging of double strand break repair protein clusters. Sci Rep 2022; 12:1305. [PMID: 35079078 PMCID: PMC8789836 DOI: 10.1038/s41598-022-05413-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 01/06/2022] [Indexed: 12/17/2022] Open
Abstract
The human body is constantly exposed to ionizing radiation of different qualities. Especially the exposure to high-LET (linear energy transfer) particles increases due to new tumor therapy methods using e.g. carbon ions. Furthermore, upon radiation accidents, a mixture of radiation of different quality is adding up to human radiation exposure. Finally, long-term space missions such as the mission to mars pose great challenges to the dose assessment an astronaut was exposed to. Currently, DSB counting using γH2AX foci is used as an exact dosimetric measure for individuals. Due to the size of the γH2AX IRIF of ~ 0.6 µm, it is only possible to count DSB when they are separated by this distance. For high-LET particle exposure, the distance of the DSB is too small to be separated and the dose will be underestimated. In this study, we developed a method where it is possible to count DSB which are separated by a distance of ~ 140 nm. We counted the number of ionizing radiation-induced pDNA-PKcs (DNA-PKcs phosphorylated at T2609) foci (size = 140 nm ± 20 nm) in human HeLa cells using STED super-resolution microscopy that has an intrinsic resolution of 100 nm. Irradiation was performed at the ion microprobe SNAKE using high-LET 20 MeV lithium (LET = 116 keV/µm) and 27 MeV carbon ions (LET = 500 keV/µm). pDNA-PKcs foci label all DSB as proven by counterstaining with 53BP1 after low-LET γ-irradiation where separation of individual DSB is in most cases larger than the 53BP1 gross size of about 0.6 µm. Lithium ions produce (1.5 ± 0.1) IRIF/µm track length, for carbon ions (2.2 ± 0.2) IRIF/µm are counted. These values are enhanced by a factor of 2–3 compared to conventional foci counting of high-LET tracks. Comparison of the measurements to PARTRAC simulation data proof the consistency of results. We used these data to develop a measure for dosimetry of high-LET or mixed particle radiation exposure directly in the biological sample. We show that proper dosimetry for radiation up to a LET of 240 keV/µm is possible.
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Affiliation(s)
- Judith Reindl
- Institute for Applied Physics and Measurement Technology, Universität Der Bundeswehr München, Neubiberg, Germany.
| | - P Kundrat
- Institute for Applied Physics and Measurement Technology, Universität Der Bundeswehr München, Neubiberg, Germany.,Department of Radiation Dosimetry, Nuclear Physics Institute CAS, Prague, Czech Republic
| | - S Girst
- Institute for Applied Physics and Measurement Technology, Universität Der Bundeswehr München, Neubiberg, Germany
| | - M Sammer
- Institute for Applied Physics and Measurement Technology, Universität Der Bundeswehr München, Neubiberg, Germany
| | - B Schwarz
- Institute for Applied Physics and Measurement Technology, Universität Der Bundeswehr München, Neubiberg, Germany
| | - G Dollinger
- Institute for Applied Physics and Measurement Technology, Universität Der Bundeswehr München, Neubiberg, Germany
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THZ531 Induces a State of BRCAness in Multiple Myeloma Cells: Synthetic Lethality with Combination Treatment of THZ 531 with DNA Repair Inhibitors. Int J Mol Sci 2022; 23:ijms23031207. [PMID: 35163134 PMCID: PMC8835885 DOI: 10.3390/ijms23031207] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/13/2022] [Accepted: 01/17/2022] [Indexed: 12/11/2022] Open
Abstract
Multiple myeloma (MM) is a hematological disease marked by abnormal growth of B cells in bone marrow. Inherent chromosomal instability and DNA damage are major hallmarks of MM, which implicates an aberrant DNA repair mechanism. Studies have implicated a role for CDK12 in the control of expression of DNA damage response genes. In this study, we examined the effect of a small molecule inhibitor of CDK12–THZ531 on MM cells. Treatment of MM cells with THZ531 led to heightened cell death accompanied by an extensive effect on gene expression changes. In particular, we observed downregulation of genes involved in DNA repair pathways. With this insight, we extended our study to identify synthetic lethal mechanisms that could be exploited for the treatment of MM cells. Combination of THZ531 with either DNA-PK inhibitor (KU-0060648) or PARP inhibitor (Olaparib) led to synergistic cell death. In addition, combination treatment of THZ531 with Olaparib significantly reduced tumor burden in animal models. Our findings suggest that using a CDK12 inhibitor in combination with other DNA repair inhibitors may establish an effective therapeutic regimen to benefit myeloma patients.
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Structural insights into inhibitor regulation of the DNA repair protein DNA-PKcs. Nature 2022; 601:643-648. [PMID: 34987222 PMCID: PMC8791830 DOI: 10.1038/s41586-021-04274-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 11/19/2021] [Indexed: 01/29/2023]
Abstract
The DNA-dependent protein kinase catalytic subunit (DNA-PKcs) has a central role in non-homologous end joining, one of the two main pathways that detect and repair DNA double-strand breaks (DSBs) in humans1,2. DNA-PKcs is of great importance in repairing pathological DSBs, making DNA-PKcs inhibitors attractive therapeutic agents for cancer in combination with DSB-inducing radiotherapy and chemotherapy3. Many of the selective inhibitors of DNA-PKcs that have been developed exhibit potential as treatment for various cancers4. Here we report cryo-electron microscopy (cryo-EM) structures of human DNA-PKcs natively purified from HeLa cell nuclear extracts, in complex with adenosine-5′-(γ-thio)-triphosphate (ATPγS) and four inhibitors (wortmannin, NU7441, AZD7648 and M3814), including drug candidates undergoing clinical trials. The structures reveal molecular details of ATP binding at the active site before catalysis and provide insights into the modes of action and specificities of the competitive inhibitors. Of note, binding of the ligands causes movement of the PIKK regulatory domain (PRD), revealing a connection between the p-loop and PRD conformations. Electrophoretic mobility shift assay and cryo-EM studies on the DNA-dependent protein kinase holoenzyme further show that ligand binding does not have a negative allosteric or inhibitory effect on assembly of the holoenzyme complex and that inhibitors function through direct competition with ATP. Overall, the structures described in this study should greatly assist future efforts in rational drug design targeting DNA-PKcs, demonstrating the potential of cryo-EM in structure-guided drug development for large and challenging targets. Cryo-electron microscopy structures of DNA-dependent protein kinase catalytic subunit bound to ATPγS and four inhibitors (wortmannin, NU7441, AZD7648 and M3814) provide molecular details and insights useful for drug design.
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Autophosphorylation transforms DNA-PK from protecting to processing DNA ends. Mol Cell 2022; 82:177-189.e4. [PMID: 34936881 PMCID: PMC8916119 DOI: 10.1016/j.molcel.2021.11.025] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 10/18/2021] [Accepted: 11/23/2021] [Indexed: 01/09/2023]
Abstract
The DNA-dependent protein kinase (DNA-PK) initially protects broken DNA ends but then promotes their processing during non-homologous end joining (NHEJ). Before ligation by NHEJ, DNA hairpin ends generated during V(D)J recombination must be opened by the Artemis nuclease, together with autophosphorylated DNA-PK. Structures of DNA-PK bound to DNA before and after phosphorylation, and in complex with Artemis and a DNA hairpin, reveal an essential functional switch. When bound to open DNA ends in its protection mode, DNA-PK is inhibited for cis-autophosphorylation of the so-called ABCDE cluster but activated for phosphorylation of other targets. In contrast, DNA hairpin ends promote cis-autophosphorylation. Phosphorylation of four Thr residues in ABCDE leads to gross structural rearrangement of DNA-PK, widening the DNA binding groove for Artemis recruitment and hairpin cleavage. Meanwhile, Artemis locks DNA-PK into the kinase-inactive state. Kinase activity and autophosphorylation of DNA-PK are regulated by different DNA ends, feeding forward to coordinate NHEJ events.
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43
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Liu L, Dai X, Yin S, Liu P, Hill EG, Wei W, Gan W. DNA-PK promotes activation of the survival kinase AKT in response to DNA damage through an mTORC2-ECT2 pathway. Sci Signal 2022; 15:eabh2290. [PMID: 34982576 DOI: 10.1126/scisignal.abh2290] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Liu Liu
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA.,Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Xiaoming Dai
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Shasha Yin
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA.,Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Pengda Liu
- Lineberger Comprehensive Cancer Center and Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Elizabeth G Hill
- Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA.,Department of Public Health Sciences, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Wenyi Wei
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Wenjian Gan
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA.,Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA
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44
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Li YL, Wang ZX, Ying CZ, Zhang BR, Pu JL. Decoding the Role of Familial Parkinson’s Disease-Related Genes in DNA Damage and Repair. Aging Dis 2022; 13:1405-1412. [PMID: 36186134 PMCID: PMC9466978 DOI: 10.14336/ad.2022.0216] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 02/16/2022] [Indexed: 11/01/2022] Open
Abstract
Parkinson's disease (PD) is a neurodegenerative disease characterized by the degeneration of midbrain substantia nigra pars compacta dopaminergic neurons and the formation of Lewy bodies. Over the years, researchers have gained extensive knowledge about dopaminergic neuron degeneration from the perspective of the environmental and disease-causing genetic factors; however, there is still no disease-modifying therapy. Aging has long been recognized as a major risk factor for PD; however, little is known about how aging contributes to the disease development. Genome instability is the main driving force behind aging, and has been poorly studied in patients with PD. Here, we summarize the evidence for nuclear DNA damage in PD. We also discuss the molecular mechanisms of nuclear DNA damage and repair in PD, especially from the perspective of familial PD-related mutant genes. Understanding the significance of DNA damage and repair may provide new potential intervention targets for treating PD.
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Affiliation(s)
| | | | | | | | - Jia-Li Pu
- Correspondence should be addressed to: Dr. Jia-Li Pu Department of Neurology, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China. .
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45
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Coleman N, Moyers JT, Harbery A, Vivanco I, Yap TA. Clinical Development of AKT Inhibitors and Associated Predictive Biomarkers to Guide Patient Treatment in Cancer Medicine. Pharmgenomics Pers Med 2021; 14:1517-1535. [PMID: 34858045 PMCID: PMC8630372 DOI: 10.2147/pgpm.s305068] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 11/03/2021] [Indexed: 11/29/2022] Open
Abstract
The serine/threonine kinase AKT is a critical effector of the phosphoinositide 3-kinase (PI3K) signaling cascade and has a pivotal role in cell growth, proliferation, survival, and metabolism. AKT is one of the most commonly activated pathways in human cancer and dysregulation of AKT-dependent pathways is associated with the development and maintenance of a range of solid tumors. There are multiple small-molecule inhibitors targeting different components of the PI3K/AKT pathway currently at various stages of clinical development, in addition to new combination strategies aiming to boost the therapeutic efficacy of these drugs. Correlative and translational studies have been undertaken in the context of clinical trials investigating AKT inhibitors, however the identification of predictive biomarkers of response and resistance to AKT inhibition remains an unmet need. In this review, we discuss the biological function and activation of AKT, discuss its contribution to tumor development and progression, and review the efficacy and toxicity data from clinical trials, including both AKT inhibitor monotherapy and combination strategies with other agents. We also discuss the promise and challenges associated with the development of AKT inhibitors and associated predictive biomarkers of response and resistance.
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Affiliation(s)
- Niamh Coleman
- Department of Investigational Cancer Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Justin T Moyers
- Department of Investigational Cancer Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Division of Hematology and Oncology, Department of Medicine, University of California, Irvine, Orange, CA, USA
| | - Alice Harbery
- Division of Cancer Therapeutics, Institute of Cancer Research, London, SM2 5NG, UK
| | - Igor Vivanco
- Institute of Pharmaceutical Sciences, School of Cancer and Pharmaceutical Sciences, King’s College London, London, UK
| | - Timothy A Yap
- Department of Investigational Cancer Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Institute for Applied Cancer Science, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Khalifa Institute for Personalized Cancer Therapy, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
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46
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Cardinale A, Saladini S, Lupacchini L, Ruspantini I, De Dominicis C, Papale M, Silvagno F, Garaci E, Mollinari C, Merlo D. DNA repair protein DNA-PK protects PC12 cells from oxidative stress-induced apoptosis involving AKT phosphorylation. Mol Biol Rep 2021; 49:1089-1101. [PMID: 34797489 PMCID: PMC8825611 DOI: 10.1007/s11033-021-06934-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 11/05/2021] [Indexed: 11/30/2022]
Abstract
Background Emerging evidence suggest that DNA-PK complex plays a role in the cellular response to oxidative stress, in addition to its function of double strand break (DSB) repair. In this study we evaluated whether DNA-PK participates in oxidative stress response and whether this role is independent of its function in DNA repair. Methods and results We used a model of H2O2-induced DNA damage in PC12 cells (rat pheochromocytoma), a well-known neuronal tumor cell line. We found that H2O2 treatment of PC12 cells induces an increase in DNA-PK protein complex levels, along with an elevation of DNA damage, measured both by the formation of γΗ2ΑX foci, detected by immunofluorescence, and γH2AX levels detected by western blot analysis. After 24 h of cell recovery, γΗ2ΑX foci are repaired both in the absence and presence of DNA-PK kinase inhibitor NU7026, while an increase of apoptotic cells is observed when DNA-PK activity is inhibited, as revealed by counting pycnotic nuclei and confirmed by FACS analysis. Our results suggest a role of DNA-PK as an anti-apoptotic factor in proliferating PC12 cells under oxidative stress conditions. The anti-apoptotic role of DNA-PK is associated with AKT phosphorylation in Ser473. On the contrary, in differentiated PC12 cells, were the main pathway to repair DSBs is DNA-PK-mediated, the inhibition of DNA-PK activity causes an accumulation of DNA damage. Conclusions Taken together, our results show that DNA-PK can protect cells from oxidative stress induced-apoptosis independently from its function of DSB repair enzyme. Graphical Abstract ![]()
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Affiliation(s)
- Alessio Cardinale
- Molecular and Cellular Neurobiology, IRCCS San Raffaele Roma, Via di Val Cannuta 247, 00166, Rome, Italy
| | - Serena Saladini
- Molecular and Cellular Neurobiology, IRCCS San Raffaele Roma, Via di Val Cannuta 247, 00166, Rome, Italy
| | - Leonardo Lupacchini
- Molecular and Cellular Neurobiology, IRCCS San Raffaele Roma, Via di Val Cannuta 247, 00166, Rome, Italy
| | - Irene Ruspantini
- FAST. Istituto Superiore di Sanita', Viale Regina Elena 299, 00161, Rome, Italy
| | - Chiara De Dominicis
- Molecular and Cellular Neurobiology, IRCCS San Raffaele Roma, Via di Val Cannuta 247, 00166, Rome, Italy.,Department of Neuroscience, Istituto Superiore di Sanita', Viale Regina Elena 299, 00161, Rome, Italy
| | - Marco Papale
- Molecular and Cellular Neurobiology, IRCCS San Raffaele Roma, Via di Val Cannuta 247, 00166, Rome, Italy
| | - Francesca Silvagno
- Department of Oncology, University Torino, via Santena 5 bis, 10126, Torino, Italy
| | - Enrico Garaci
- University San Raffaele, Via di Val Cannuta 247, 00166, Rome, Italy
| | - Cristiana Mollinari
- Department of Neuroscience, Istituto Superiore di Sanita', Viale Regina Elena 299, 00161, Rome, Italy.,Institute of Translational Pharmacology, National Research Council, Via Fosso del Cavaliere 100, 00133, Rome, Italy
| | - Daniela Merlo
- Department of Neuroscience, Istituto Superiore di Sanita', Viale Regina Elena 299, 00161, Rome, Italy.
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47
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Kong M, Greene EC. Mechanistic Insights From Single-Molecule Studies of Repair of Double Strand Breaks. Front Cell Dev Biol 2021; 9:745311. [PMID: 34869333 PMCID: PMC8636147 DOI: 10.3389/fcell.2021.745311] [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: 07/21/2021] [Accepted: 10/28/2021] [Indexed: 01/01/2023] Open
Abstract
DNA double strand breaks (DSBs) are among some of the most deleterious forms of DNA damage. Left unrepaired, they are detrimental to genome stability, leading to high risk of cancer. Two major mechanisms are responsible for the repair of DSBs, homologous recombination (HR) and nonhomologous end joining (NHEJ). The complex nature of both pathways, involving a myriad of protein factors functioning in a highly coordinated manner at distinct stages of repair, lend themselves to detailed mechanistic studies using the latest single-molecule techniques. In avoiding ensemble averaging effects inherent to traditional biochemical or genetic methods, single-molecule studies have painted an increasingly detailed picture for every step of the DSB repair processes.
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Affiliation(s)
| | - Eric C. Greene
- Department of Biochemistry and Molecular Biophysics, Columbia University Irving Medical Center, New York, NY, United States
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48
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Singh JK, Smith R, Rother MB, de Groot AJL, Wiegant WW, Vreeken K, D’Augustin O, Kim RQ, Qian H, Krawczyk PM, González-Prieto R, Vertegaal ACO, Lamers M, Huet S, van Attikum H. Zinc finger protein ZNF384 is an adaptor of Ku to DNA during classical non-homologous end-joining. Nat Commun 2021; 12:6560. [PMID: 34772923 PMCID: PMC8589989 DOI: 10.1038/s41467-021-26691-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 10/19/2021] [Indexed: 12/14/2022] Open
Abstract
DNA double-strand breaks (DSBs) are among the most deleterious types of DNA damage as they can lead to mutations and chromosomal rearrangements, which underlie cancer development. Classical non-homologous end-joining (cNHEJ) is the dominant pathway for DSB repair in human cells, involving the DNA-binding proteins XRCC6 (Ku70) and XRCC5 (Ku80). Other DNA-binding proteins such as Zinc Finger (ZnF) domain-containing proteins have also been implicated in DNA repair, but their role in cNHEJ remained elusive. Here we show that ZNF384, a member of the C2H2 family of ZnF proteins, binds DNA ends in vitro and is recruited to DSBs in vivo. ZNF384 recruitment requires the poly(ADP-ribosyl) polymerase 1 (PARP1)-dependent expansion of damaged chromatin, followed by binding of its C2H2 motifs to the exposed DNA. Moreover, ZNF384 interacts with Ku70/Ku80 via its N-terminus, thereby promoting Ku70/Ku80 assembly and the accrual of downstream cNHEJ factors, including APLF and XRCC4/LIG4, for efficient repair at DSBs. Altogether, our data suggest that ZNF384 acts as a 'Ku-adaptor' that binds damaged DNA and Ku70/Ku80 to facilitate the build-up of a cNHEJ repairosome, highlighting a role for ZNF384 in DSB repair and genome maintenance.
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Affiliation(s)
- Jenny Kaur Singh
- grid.10419.3d0000000089452978Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Rebecca Smith
- grid.410368.80000 0001 2191 9284Univ Rennes, CNRS, IGDR (Institut de génétique et développement de Rennes)—UMR 6290, BIOSIT–UMS3480, F-35000 Rennes, France
| | - Magdalena B. Rother
- grid.10419.3d0000000089452978Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Anton J. L. de Groot
- grid.10419.3d0000000089452978Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Wouter W. Wiegant
- grid.10419.3d0000000089452978Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Kees Vreeken
- grid.10419.3d0000000089452978Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Ostiane D’Augustin
- grid.410368.80000 0001 2191 9284Univ Rennes, CNRS, IGDR (Institut de génétique et développement de Rennes)—UMR 6290, BIOSIT–UMS3480, F-35000 Rennes, France ,grid.457349.80000 0004 0623 0579Institut de Biologie François Jacob, Institute of Cellular and Molecular Radiobiology, Université Paris-Saclay, Université de Paris, CEA, F-92265 Fontenay-aux-Roses, France
| | - Robbert Q. Kim
- grid.10419.3d0000000089452978Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Haibin Qian
- grid.16872.3a0000 0004 0435 165XDepartment of Medical Biology, Amsterdam University Medical Centers (location AMC), Cancer Center Amsterdam, Amsterdam, The Netherlands
| | - Przemek M. Krawczyk
- grid.16872.3a0000 0004 0435 165XDepartment of Medical Biology, Amsterdam University Medical Centers (location AMC), Cancer Center Amsterdam, Amsterdam, The Netherlands
| | - Román González-Prieto
- grid.16872.3a0000 0004 0435 165XDepartment of Medical Biology, Amsterdam University Medical Centers (location AMC), Cancer Center Amsterdam, Amsterdam, The Netherlands
| | - Alfred C. O. Vertegaal
- grid.16872.3a0000 0004 0435 165XDepartment of Medical Biology, Amsterdam University Medical Centers (location AMC), Cancer Center Amsterdam, Amsterdam, The Netherlands
| | - Meindert Lamers
- grid.16872.3a0000 0004 0435 165XDepartment of Medical Biology, Amsterdam University Medical Centers (location AMC), Cancer Center Amsterdam, Amsterdam, The Netherlands
| | - Sébastien Huet
- grid.410368.80000 0001 2191 9284Univ Rennes, CNRS, IGDR (Institut de génétique et développement de Rennes)—UMR 6290, BIOSIT–UMS3480, F-35000 Rennes, France ,grid.440891.00000 0001 1931 4817Institut Universitaire de France, F-75000 Paris, France
| | - Haico van Attikum
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands.
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49
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Lai D, Huang X, Wang C, Ow DW. Arabidopsis OXIDATIVE STRESS 3 enhances stress tolerance in Schizosaccharomyces pombe by promoting histone subunit replacement that upregulates drug-resistant genes. Genetics 2021; 219:6371188. [PMID: 34740252 DOI: 10.1093/genetics/iyab149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 09/04/2021] [Indexed: 11/14/2022] Open
Abstract
Histone replacement in chromatin-remodeling plays an important role in eukaryotic gene expression. New histone variants replacing their canonical counterparts often lead to a change in transcription, including responses to stresses caused by temperature, drought, salinity, and heavy metals. In this study, we describe a chromatin-remodeling process triggered by eviction of Rad3/Tel1-phosphorylated H2Aα, in which a heterologous plant protein AtOXS3 can subsequently bind fission yeast HA2.Z and Swc2, a component of the SWR1 complex, to facilitate replacement of H2Aα with H2A.Z. The histone replacement increases occupancy of the oxidative stress-responsive transcription factor Pap1 at the promoters of at least three drug-resistant genes, which enhances their transcription and hence primes the cell for higher stress tolerance.
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Affiliation(s)
- Dingwang Lai
- Plant Gene Engineering Center, Chinese Academy of Sciences Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiuting Huang
- Plant Gene Engineering Center, Chinese Academy of Sciences Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Changhu Wang
- Plant Gene Engineering Center, Chinese Academy of Sciences Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
| | - David W Ow
- Plant Gene Engineering Center, Chinese Academy of Sciences Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
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50
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Khanam T, Muñoz I, Weiland F, Carroll T, Morgan M, Borsos BN, Pantazi V, Slean M, Novak M, Toth R, Appleton P, Pankotai T, Zhou H, Rouse J. CDKL5 kinase controls transcription-coupled responses to DNA damage. EMBO J 2021; 40:e108271. [PMID: 34605059 PMCID: PMC8634139 DOI: 10.15252/embj.2021108271] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 09/08/2021] [Accepted: 09/09/2021] [Indexed: 12/19/2022] Open
Abstract
Mutations in the gene encoding the CDKL5 kinase are among the most common genetic causes of childhood epilepsy and can also give rise to the severe neurodevelopmental condition CDD (CDKL5 deficiency disorder). Despite its importance for human health, the phosphorylation targets and cellular roles of CDKL5 are poorly understood, especially in the cell nucleus. Here, we report that CDKL5 is recruited to sites of DNA damage in actively transcribed regions of the nucleus. A quantitative phosphoproteomic screen for nuclear CDKL5 substrates reveals a network of transcriptional regulators including Elongin A (ELOA), phosphorylated on a specific CDKL5 consensus motif. Recruitment of CDKL5 and ELOA to damaged DNA, and subsequent phosphorylation of ELOA, requires both active transcription and the synthesis of poly(ADP‐ribose) (PAR), to which CDKL5 can bind. Critically, CDKL5 kinase activity is essential for the transcriptional silencing of genes induced by DNA double‐strand breaks. Thus, CDKL5 is a DNA damage‐sensing, PAR‐controlled transcriptional modulator, a finding with implications for understanding the molecular basis of CDKL5‐related diseases.
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Affiliation(s)
- Taran Khanam
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - Ivan Muñoz
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - Florian Weiland
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - Thomas Carroll
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - Michael Morgan
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - Barbara N Borsos
- Albert Szent-Györgyi Medical School, Institute of Pathology, University of Szeged, Szeged, Hungary
| | - Vasiliki Pantazi
- Albert Szent-Györgyi Medical School, Institute of Pathology, University of Szeged, Szeged, Hungary
| | - Meghan Slean
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - Miroslav Novak
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - Rachel Toth
- MRC Reagents and Services, School of Life Sciences, University of Dundee, Dundee, UK
| | - Paul Appleton
- Dundee Imaging Facility, School of Life Sciences, University of Dundee, Dundee, UK
| | - Tibor Pankotai
- Albert Szent-Györgyi Medical School, Institute of Pathology, University of Szeged, Szeged, Hungary
| | - Houjiang Zhou
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - John Rouse
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
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