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Singh A, Ravendranathan N, Frisbee JC, Singh KK. Complex Interplay between DNA Damage and Autophagy in Disease and Therapy. Biomolecules 2024; 14:922. [PMID: 39199310 PMCID: PMC11352539 DOI: 10.3390/biom14080922] [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: 06/25/2024] [Revised: 07/19/2024] [Accepted: 07/26/2024] [Indexed: 09/01/2024] Open
Abstract
Cancer, a multifactorial disease characterized by uncontrolled cellular proliferation, remains a global health challenge with significant morbidity and mortality. Genomic and molecular aberrations, coupled with environmental factors, contribute to its heterogeneity and complexity. Chemotherapeutic agents like doxorubicin (Dox) have shown efficacy against various cancers but are hindered by dose-dependent cytotoxicity, particularly on vital organs like the heart and brain. Autophagy, a cellular process involved in self-degradation and recycling, emerges as a promising therapeutic target in cancer therapy and neurodegenerative diseases. Dysregulation of autophagy contributes to cancer progression and drug resistance, while its modulation holds the potential to enhance treatment outcomes and mitigate adverse effects. Additionally, emerging evidence suggests a potential link between autophagy, DNA damage, and caretaker breast cancer genes BRCA1/2, highlighting the interplay between DNA repair mechanisms and cellular homeostasis. This review explores the intricate relationship between cancer, Dox-induced cytotoxicity, autophagy modulation, and the potential implications of autophagy in DNA damage repair pathways, particularly in the context of BRCA1/2 mutations.
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Affiliation(s)
- Aman Singh
- Department of Medical Biophysics, Schulich School of Medicine and Dentistry, University of Western Ontario, 1151 Richmond Street North, London, ON N6A 5C1, Canada; (A.S.); (N.R.); (J.C.F.)
| | - Naresh Ravendranathan
- Department of Medical Biophysics, Schulich School of Medicine and Dentistry, University of Western Ontario, 1151 Richmond Street North, London, ON N6A 5C1, Canada; (A.S.); (N.R.); (J.C.F.)
| | - Jefferson C. Frisbee
- Department of Medical Biophysics, Schulich School of Medicine and Dentistry, University of Western Ontario, 1151 Richmond Street North, London, ON N6A 5C1, Canada; (A.S.); (N.R.); (J.C.F.)
| | - Krishna K. Singh
- Department of Medical Biophysics, Schulich School of Medicine and Dentistry, University of Western Ontario, 1151 Richmond Street North, London, ON N6A 5C1, Canada; (A.S.); (N.R.); (J.C.F.)
- Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON N6A 5C1, Canada
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Mustafa Karim A, Eun Kwon J, Ali T, Jang J, Ullah I, Lee YG, Won Park D, Park J, Woo Jeang J, Chan Kang S. Triple-negative breast cancer: epidemiology, molecular mechanisms, and modern vaccine-based treatment strategies. Biochem Pharmacol 2023; 212:115545. [PMID: 37044296 DOI: 10.1016/j.bcp.2023.115545] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 04/03/2023] [Accepted: 04/04/2023] [Indexed: 04/14/2023]
Abstract
Long-standing scarcity of efficacious treatments and tumor heterogeneity have contributed to triple-negative breast cancer (TNBC), a subtype with a poor prognosis and aggressive behavior that accounts for 10-15% of all new cases of breast cancer. TNBC is characterized by the absence of progesterone and estrogen receptor expression and lacks gene amplification or overexpression of HER2. Genomic sequencing has detected that the unique mutational profile of both the somatic and germline modifications in TNBC is staggeringly dissimilar from other breast tumor subtypes. The clinical utility of sequencing germline BRCA1/2 genes has been well established in TNBC. Nevertheless, reports regarding the penetrance and risk of other susceptibility genes are relatively scarce. Recurring mutations (e.g., TP53 and PI3KCA mutations) occur together with rare mutations in TNBC, and the shared effects of genomic modifications drive its progression. Given the heterogeneity and complexity of this disease, a clinical understanding of the genomic modifications in TNBC can pave an innovative way toward its therapy. In this review, we summarized the most recent discoveries associated with the underlying biology of developmental signaling pathways in TNBC. We also summarize the recent advancements in genetics and epidemiology and discuss state-of-the-art vaccine-based therapeutic strategies for TNBC that will enable tailored therapeutics.
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Affiliation(s)
- Asad Mustafa Karim
- Department of Oriental Medicine and Biotechnology, College of Life Sciences, Kyung Hee University, Yongin-si, 17104, Republic of Korea.
| | - Jeong Eun Kwon
- Department of Oriental Medicine and Biotechnology, College of Life Sciences, Kyung Hee University, Yongin-si, 17104, Republic of Korea
| | - Tanveer Ali
- Department of Host Defense, Graduate School of Medicine, University of the Ryukyus, Nishihara, Japan
| | - Jinsoo Jang
- Department of Oriental Medicine and Biotechnology, College of Life Sciences, Kyung Hee University, Yongin-si, 17104, Republic of Korea
| | - Irfan Ullah
- Department of Internal Medicine, Section of Infectious Diseases, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Yeong-Geun Lee
- Department of Oriental Medicine and Biotechnology, College of Life Sciences, Kyung Hee University, Yongin-si, 17104, Republic of Korea
| | - Dae Won Park
- Department of Oriental Medicine and Biotechnology, College of Life Sciences, Kyung Hee University, Yongin-si, 17104, Republic of Korea
| | - Juha Park
- Department of Oriental Medicine and Biotechnology, College of Life Sciences, Kyung Hee University, Yongin-si, 17104, Republic of Korea
| | - Jin Woo Jeang
- Department of Oriental Medicine and Biotechnology, College of Life Sciences, Kyung Hee University, Yongin-si, 17104, Republic of Korea
| | - Se Chan Kang
- Department of Oriental Medicine and Biotechnology, College of Life Sciences, Kyung Hee University, Yongin-si, 17104, Republic of Korea.
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Keskin Karakoyun H, Yüksel ŞK, Amanoglu I, Naserikhojasteh L, Yeşilyurt A, Yakıcıer C, Timuçin E, Akyerli CB. Evaluation of AlphaFold structure-based protein stability prediction on missense variations in cancer. Front Genet 2023; 14:1052383. [PMID: 36896237 PMCID: PMC9988940 DOI: 10.3389/fgene.2023.1052383] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 02/08/2023] [Indexed: 02/23/2023] Open
Abstract
Identifying pathogenic missense variants in hereditary cancer is critical to the efforts of patient surveillance and risk-reduction strategies. For this purpose, many different gene panels consisting of different number and/or set of genes are available and we are particularly interested in a panel of 26 genes with a varying degree of hereditary cancer risk consisting of ABRAXAS1, ATM, BARD1, BLM, BRCA1, BRCA2, BRIP1, CDH1, CHEK2, EPCAM, MEN1, MLH1, MRE11, MSH2, MSH6, MUTYH, NBN, PALB2, PMS2, PTEN, RAD50, RAD51C, RAD51D, STK11, TP53, and XRCC2. In this study, we have compiled a collection of the missense variations reported in any of these 26 genes. More than a thousand missense variants were collected from ClinVar and the targeted screen of a breast cancer cohort of 355 patients which contributed to this set with 160 novel missense variations. We analyzed the impact of the missense variations on protein stability by five different predictors including both sequence- (SAAF2EC and MUpro) and structure-based (Maestro, mCSM, CUPSAT) predictors. For the structure-based tools, we have utilized the AlphaFold (AF2) protein structures which comprise the first structural analysis of this hereditary cancer proteins. Our results agreed with the recent benchmarks that computed the power of stability predictors in discriminating the pathogenic variants. Overall, we reported a low-to-medium-level performance for the stability predictors in discriminating pathogenic variants, except MUpro which had an AUROC of 0.534 (95% CI [0.499-0.570]). The AUROC values ranged between 0.614-0.719 for the total set and 0.596-0.682 for the set with high AF2 confidence regions. Furthermore, our findings revealed that the confidence score for a given variant in the AF2 structure could alone predict pathogenicity more robustly than any of the tested stability predictors with an AUROC of 0.852. Altogether, this study represents the first structural analysis of the 26 hereditary cancer genes underscoring 1) the thermodynamic stability predicted from AF2 structures as a moderate and 2) the confidence score of AF2 as a strong descriptor for variant pathogenicity.
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Affiliation(s)
- Hilal Keskin Karakoyun
- Department of Biochemistry and Molecular Biology, Institute of Health Sciences, Acibadem Mehmet Ali Aydinlar University, Istanbul, Türkiye
| | - Şirin K. Yüksel
- Department of Biochemistry and Molecular Biology, Institute of Health Sciences, Acibadem Mehmet Ali Aydinlar University, Istanbul, Türkiye
| | - Ilayda Amanoglu
- Department of Biostatistics and Bioinformatics, Institute of Health Sciences, Acibadem Mehmet Ali Aydinlar University, Istanbul, Türkiye
| | - Lara Naserikhojasteh
- Department of Biostatistics and Bioinformatics, Institute of Health Sciences, Acibadem Mehmet Ali Aydinlar University, Istanbul, Türkiye
| | - Ahmet Yeşilyurt
- Acibadem Labgen Genetic Diagnosis Centre, Acibadem Health Group, Istanbul, Türkiye
| | - Cengiz Yakıcıer
- Acibadem Pathology Laboratories, Acibadem Health Group, Istanbul, Türkiye
| | - Emel Timuçin
- Department of Biostatistics and Medical Informatics, School of Medicine, Acibadem Mehmet Ali Aydinlar University, Istanbul, Türkiye
| | - Cemaliye B. Akyerli
- Department of Medical Biology, School of Medicine, Acibadem Mehmet Ali Aydinlar University, Istanbul, Türkiye
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Alterations in the p53 isoform ratio govern breast cancer cell fate in response to DNA damage. Cell Death Dis 2022; 13:907. [PMID: 36307393 PMCID: PMC9616954 DOI: 10.1038/s41419-022-05349-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 10/13/2022] [Accepted: 10/14/2022] [Indexed: 11/07/2022]
Abstract
Our previous studies have shown that p53 isoform expression is altered in breast cancer and related to prognosis. In particular, a high ∆40p53:p53α ratio is associated with worse disease-free survival. In this manuscript, the influence of altered Δ40p53 and p53α levels on the response to standard of care DNA-damaging agents used in breast cancer treatment was investigated in vitro. Our results revealed that a high Δ40p53:p53α ratio causes cells to respond differently to doxorubicin and cisplatin treatments. Δ40p53 overexpression significantly impairs the cells' sensitivity to doxorubicin through reducing apoptosis and DNA damage, whereas Δ40p53 knockdown has the opposite effect. Further, a high Δ40p53:p53α ratio inhibited the differential expression of several genes following doxorubicin and promoted DNA repair, impairing the cells' canonical response. Overall, our results suggest that the response of breast cancer cells to standard of care DNA-damaging therapies is dependent on the expression of p53 isoforms, which may contribute to outcomes in breast cancer.
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The Effect of Aflatoxin B1 on Tumor-Related Genes and Phenotypic Characters of MCF7 and MCF10A Cells. Int J Mol Sci 2022; 23:ijms231911856. [PMID: 36233156 PMCID: PMC9570345 DOI: 10.3390/ijms231911856] [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: 07/26/2022] [Revised: 09/13/2022] [Accepted: 09/17/2022] [Indexed: 11/21/2022] Open
Abstract
The fungal toxin aflatoxin B1 (AB1) and its reactive intermediate, aflatoxin B1-8, 9 epoxide, could cause liver cancer by inducing DNA adducts. AB1 exposure can induce changes in the expression of several cancer-related genes. In this study, the effect of AB1 exposure on breast cancer MCF7 and normal breast MCF10A cell lines at the phenotypic and epigenetic levels was investigated to evaluate its potential in increasing the risk of breast cancer development. We hypothesized that, even at low concentrations, AB1 can cause changes in the expression of important genes involved in four pathways, i.e., p53, cancer, cell cycle, and apoptosis. The transcriptomic levels of BRCA1, BRCA2, p53, HER1, HER2, cMyc, BCL2, MCL1, CCND1, WNT3A, MAPK1, MAPK3, DAPK1, Casp8, and Casp9 were determined in MCF7 and MCF10A cells. Our results illustrate that treating both cells with AB1 induced cytotoxicity and apoptosis with reduction in cell viability in a concentration-dependent manner. Additionally, AB1 reduced reactive oxygen species levels. Phenotypically, AB1 caused cell-cycle arrest at G1, hypertrophy, and increased cell migration rates. There were changes in the expression levels of several tumor-related genes, which are known to contribute to activating cancer pathways. The effects of AB1 on the phenotype and epigenetics of both MCF7 and MCF10A cells associated with cancer development observed in this study suggest that AB1 is a potential risk factor for developing breast cancer.
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Chatterjee C, Singh SK. Peptide and protein chemistry approaches to study the tumor suppressor protein p53. Org Biomol Chem 2022; 20:5500-5509. [PMID: 35786742 PMCID: PMC10112546 DOI: 10.1039/d2ob00902a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The tumor suppressor and master gene regulator protein p53 has been the subject of intense investigation for several decades due to its mutation in about half of all human cancers. However, mechanistic studies of p53 in cells are complicated by its many dynamic binding partners and heterogeneous post-translational modifications. The design of therapeutics that rescue p53 functions in cells requires a mechanistic understanding of its protein-protein interactions in specific protein complexes and identifying changes in p53 activity by diverse post-translational modifications. This review highlights the important roles that peptide and protein chemistry have played in biophysical and biochemical studies aimed at elucidating p53 regulation by several key binding partners. The design of various peptide inhibitors that rescue p53 function in cells and new opportunities in targeting p53-protein interactions are discussed. In addition, the review highlights the importance of a protein semisynthesis approach to comprehend the role of site-specific PTMs in p53 regulation.
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Affiliation(s)
- Champak Chatterjee
- Department of Chemistry, University of Washington, Seattle, WA 98195, USA.
| | - Sumeet K Singh
- Department of Chemistry, University of Washington, Seattle, WA 98195, USA.
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Costanza A, Guaragnella N, Bobba A, Manzari C, L'Abbate A, Giudice CL, Picardi E, D'Erchia AM, Pesole G, Giannattasio S. Yeast as a Model to Unravel New BRCA2 Functions in Cell Metabolism. Front Oncol 2022; 12:908442. [PMID: 35734584 PMCID: PMC9207209 DOI: 10.3389/fonc.2022.908442] [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: 03/30/2022] [Accepted: 05/06/2022] [Indexed: 11/13/2022] Open
Abstract
Mutations in BRCA2 gene increase the risk for breast cancer and for other cancer types, including pancreatic and prostate cancer. Since its first identification as an oncosupressor in 1995, the best-characterized function of BRCA2 is in the repair of DNA double-strand breaks (DSBs) by homologous recombination. BRCA2 directly interacts with both RAD51 and single-stranded DNA, mediating loading of RAD51 recombinase to sites of single-stranded DNA. In the absence of an efficient homologous recombination pathway, DSBs accumulate resulting in genome instability, thus supporting tumorigenesis. Yet the precise mechanism by which BRCA2 exerts its tumor suppressor function remains unclear. BRCA2 has also been involved in other biological functions including protection of telomere integrity and stalled replication forks, cell cycle progression, transcriptional control and mitophagy. Recently, we and others have reported a role of BRCA2 in modulating cell death programs through a molecular mechanism conserved in yeast and mammals. Here we hypothesize that BRCA2 is a multifunctional protein which exerts specific functions depending on cell stress response pathway. Based on a differential RNA sequencing analysis carried out on yeast cells either growing or undergoing a regulated cell death process, either in the absence or in the presence of BRCA2, we suggest that BRCA2 causes central carbon metabolism reprogramming in response to death stimuli and encourage further investigation on the role of metabolic reprogramming in BRCA2 oncosuppressive function.
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Affiliation(s)
- Alessandra Costanza
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, National Research Council, Bari, Italy
| | - Nicoletta Guaragnella
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, National Research Council, Bari, Italy.,Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari "Aldo Moro", Bari, Italy
| | - Antonella Bobba
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, National Research Council, Bari, Italy
| | - Caterina Manzari
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari "Aldo Moro", Bari, Italy
| | - Alberto L'Abbate
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, National Research Council, Bari, Italy
| | - Claudio Lo Giudice
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari "Aldo Moro", Bari, Italy
| | - Ernesto Picardi
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, National Research Council, Bari, Italy.,Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari "Aldo Moro", Bari, Italy
| | - Anna Maria D'Erchia
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, National Research Council, Bari, Italy.,Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari "Aldo Moro", Bari, Italy
| | - Graziano Pesole
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, National Research Council, Bari, Italy.,Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari "Aldo Moro", Bari, Italy
| | - Sergio Giannattasio
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, National Research Council, Bari, Italy
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Lo Faro V, Ten Brink JB, Snieder H, Jansonius NM, Bergen AA. Genome-wide CNV investigation suggests a role for cadherin, Wnt, and p53 pathways in primary open-angle glaucoma. BMC Genomics 2021; 22:590. [PMID: 34348663 PMCID: PMC8336345 DOI: 10.1186/s12864-021-07846-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 06/18/2021] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND To investigate whether copy number variations (CNVs) are implicated in molecular mechanisms underlying primary open-angle glaucoma (POAG), we used genotype data of POAG individuals and healthy controls from two case-control studies, AGS (n = 278) and GLGS-UGLI (n = 1292). PennCNV, QuantiSNP, and cnvPartition programs were used to detect CNV. Stringent quality controls at both sample and marker levels were applied. The identified CNVs were intersected in CNV region (CNVR). After, we performed burden analysis, CNV-genome-wide association analysis, gene set overrepresentation and pathway analysis. In addition, in human eye tissues we assessed the expression of the genes lying within significant CNVRs. RESULTS We reported a statistically significant greater burden of CNVs in POAG cases compared to controls (p-value = 0,007). In common between the two cohorts, CNV-association analysis identified statistically significant CNVRs associated with POAG that span 11 genes (APC, BRCA2, COL3A1, HLA-DRB1, HLA-DRB5, HLA-DRB6, MFSD8, NIPBL, SCN1A, SDHB, and ZDHHC11). Functional annotation and pathway analysis suggested the involvement of cadherin, Wnt signalling, and p53 pathways. CONCLUSIONS Our data suggest that CNVs may have a role in the susceptibility of POAG and they can reveal more information on the mechanism behind this disease. Additional genetic and functional studies are warranted to ascertain the contribution of CNVs in POAG.
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Affiliation(s)
- Valeria Lo Faro
- Department of Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.,Departments of Clinical Genetics and Ophthalmology, Amsterdam University Medical Center (AMC), Location AMC K2-217
- AMC-UvA, P.O.Box 22700, 1100 DE, Amsterdam, The Netherlands
| | - Jacoline B Ten Brink
- Departments of Clinical Genetics and Ophthalmology, Amsterdam University Medical Center (AMC), Location AMC K2-217
- AMC-UvA, P.O.Box 22700, 1100 DE, Amsterdam, The Netherlands
| | - Harold Snieder
- Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Nomdo M Jansonius
- Department of Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Arthur A Bergen
- Departments of Clinical Genetics and Ophthalmology, Amsterdam University Medical Center (AMC), Location AMC K2-217
- AMC-UvA, P.O.Box 22700, 1100 DE, Amsterdam, The Netherlands. .,Department of Ophthalmology, Amsterdam UMC, Location AMC, Amsterdam, The Netherlands. .,Netherlands Institute for Neuroscience (NIN-KNAW), Amsterdam, The Netherlands.
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Andreassen PR, Seo J, Wiek C, Hanenberg H. Understanding BRCA2 Function as a Tumor Suppressor Based on Domain-Specific Activities in DNA Damage Responses. Genes (Basel) 2021; 12:genes12071034. [PMID: 34356050 PMCID: PMC8307705 DOI: 10.3390/genes12071034] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 06/23/2021] [Accepted: 06/29/2021] [Indexed: 01/14/2023] Open
Abstract
BRCA2 is an essential genome stability gene that has various functions in cells, including roles in homologous recombination, G2 checkpoint control, protection of stalled replication forks, and promotion of cellular resistance to numerous types of DNA damage. Heterozygous mutation of BRCA2 is associated with an increased risk of developing cancers of the breast, ovaries, pancreas, and other sites, thus BRCA2 acts as a classic tumor suppressor gene. However, understanding BRCA2 function as a tumor suppressor is severely limited by the fact that ~70% of the encoded protein has not been tested or assigned a function in the cellular DNA damage response. Remarkably, even the specific role(s) of many known domains in BRCA2 are not well characterized, predominantly because stable expression of the very large BRCA2 protein in cells, for experimental purposes, is challenging. Here, we review what is known about these domains and the assay systems that are available to study the cellular roles of BRCA2 domains in DNA damage responses. We also list criteria for better testing systems because, ultimately, functional assays for assessing the impact of germline and acquired mutations identified in genetic screens are important for guiding cancer prevention measures and for tailored cancer treatments.
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Affiliation(s)
- Paul R. Andreassen
- Division of Experimental Hematology and Cancer Biology, Cancer and Blood Diseases Institute, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA;
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
- Correspondence: ; Tel.: +1-(513)-636-0499
| | - Joonbae Seo
- Division of Experimental Hematology and Cancer Biology, Cancer and Blood Diseases Institute, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA;
| | - Constanze Wiek
- Department of Otorhinolaryngology and Head/Neck Surgery, Heinrich Heine University, 40225 Düsseldorf, Germany; (C.W.); (H.H.)
| | - Helmut Hanenberg
- Department of Otorhinolaryngology and Head/Neck Surgery, Heinrich Heine University, 40225 Düsseldorf, Germany; (C.W.); (H.H.)
- Department of Pediatrics III, Children’s Hospital, University of Duisburg-Essen, 45122 Essen, Germany
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Sibuh BZ, Khanna S, Taneja P, Sarkar P, Taneja NK. Molecular docking, synthesis and anticancer activity of thiosemicarbazone derivatives against MCF-7 human breast cancer cell line. Life Sci 2021; 273:119305. [PMID: 33675898 DOI: 10.1016/j.lfs.2021.119305] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 02/24/2021] [Accepted: 02/25/2021] [Indexed: 02/08/2023]
Abstract
BACKGROUND The aim of this study was to synthesize and evaluate anticancer activity of 2-hydroxy benzaldehyde and 4-hydroxy benzaldehyde thiosemicarbazone (2-HBTSc and 4-HBTSc) against MCF-7 breast cancer cell line. MATERIALS AND METHODS The ligands were prepared and characterized by UV vis, IR and NMR. MTT assay was used to assess viability of cells. RNA isolation, extraction and cDNA synthesis were done. Then all groups were subjected to RT-qPCR using Gene expression specific primers. Also, western blot protein expression and molecular docking were done. Two-way ANOVA with Tukey post-hoc test was employed to test the significance using GraphPad Prism. RESULTS The IC50 values were 3.36μg/ml and 3.60μg/ml for 2-HBTSc and 4-HBTSc treated MCF-7 tumor cells respectively. Tumor cell growth inhibition ranged from 38 to 49.27% in 4-HBTSc treated cells, and 19 to 25% in 2-HBTSc treated cells with increase in doses 5 μg/ml to 20 μg/ml. The protein and gene expression result showed a significant upregulation in tumor suppressor and apoptosis inducing genes while, oncogene activity was significantly downregulated. Specifically, BRCA2 and pRB gene showed the highest expression in 4-HBTSc and 2-HBTSc treated cells respectively. Conversely, RAS oncogene was downregulated significantly. Docking result showed that both 2-HBTSc and 4-HBTSc have the potential to inhibit Estrogen Receptor Alpha Ligand Binding Domain, Human 17-Beta-hydroxysteroid dehydrogenase type 1 mutant protein and Human Topoisomerase II alpha that are expressed more during Breast Cancer. CONCLUSION The findings of this study imply that the test compound has potential for further study.
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Affiliation(s)
- Belay Zeleke Sibuh
- Department of Biotechnology, School of Engineering and Technology, Sharda University, Greater Noida, U. P., India
| | - Sonia Khanna
- Department of Chemistry and Biochemistry, School of Basic Sciences and Research, Sharda University, Greater Noida, U. P., India
| | - Pankaj Taneja
- Department of Biotechnology, School of Engineering and Technology, Sharda University, Greater Noida, U. P., India.
| | - Paratpar Sarkar
- Department of Chemistry and Biochemistry, School of Basic Sciences and Research, Sharda University, Greater Noida, U. P., India
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Singh S, Nguyen H, Michels D, Bazinet H, Matkar PN, Liu Z, Esene L, Adam M, Bugyei‐Twum A, Mebrahtu E, Joseph J, Ehsan M, Chen HH, Qadura M, Singh KK. BReast CAncer susceptibility gene 2 deficiency exacerbates oxidized LDL-induced DNA damage and endothelial apoptosis. Physiol Rep 2020; 8:e14481. [PMID: 32638521 PMCID: PMC7340845 DOI: 10.14814/phy2.14481] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 03/18/2020] [Accepted: 05/15/2020] [Indexed: 12/24/2022] Open
Abstract
Mutations in the tumor suppressor gene BRCA2 (BReast CAncer susceptibility gene 2) predispose carriers to breast, ovarian, and other cancers. In response to DNA damage, BRCA2 participates in homology-directed DNA damage repair to maintain genome stability. Genome-wide association studies have identified an association between BRCA2 single nucleotide polymorphisms and plasma-lipid levels and lipid deregulation in humans. To date, DNA damage, apoptosis, and lipid deregulation are recognized as central pathways for endothelial dysfunction and atherosclerosis; however, the role of BRCA2 in endothelial dysfunction remains to be elucidated. To determine the role of BRCA2 in endothelial dysfunction, BRCA2 was silenced in human umbilical vein endothelial cells (ECs) and assessed for markers of DNA damage, apoptosis, and endothelial function following oxidized low-density lipoprotein (oxLDL) treatment. OxLDL was found to induce significant reactive oxygen species (ROS) production in BRCA2-silenced ECs. This increase in ROS production was associated with exacerbated DNA damage evidenced by increased expression and activation of DNA double-stranded break (DSB) marker γH2AX and reduced RAD51-foci formation-an essential regulator of DSB repair. Increased DSBs were associated with enhanced expression and activation of pro-apoptotic p53 and significant apoptosis in oxLDL-treated BRCA2-silenced ECs. Loss of BRCA2 in ECs was further associated with oxLDL-induced impaired tube-forming potential and eNOS expression. Collectively, the data reveals, for the first time, a novel role of BRCA2 as a regulator of EC survival and function in the setting of oxLDL treatment in vitro. Additionally, the data provide important clues regarding the potential susceptibility of BRCA2 mutation carriers to endothelial dysfunction, atherosclerosis, and other cardiovascular diseases.
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Affiliation(s)
- Shweta Singh
- Department of Medical BiophysicsSchulich School of Medicine and DentistryUniversity of Western OntarioLondonONCanada
| | - Hien Nguyen
- Department of Medical BiophysicsSchulich School of Medicine and DentistryUniversity of Western OntarioLondonONCanada
- Anatomy and Cell BiologySchulich School of Medicine and DentistryUniversity of Western OntarioLondonONCanada
| | - David Michels
- Department of Medical BiophysicsSchulich School of Medicine and DentistryUniversity of Western OntarioLondonONCanada
| | - Hannah Bazinet
- Department of Medical BiophysicsSchulich School of Medicine and DentistryUniversity of Western OntarioLondonONCanada
| | - Pratiek N. Matkar
- Division of CardiologyKeenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's HospitalTorontoONCanada
- Institute of Medical ScienceUniversity of TorontoTorontoONCanada
| | - Zongyi Liu
- Department of Medical BiophysicsSchulich School of Medicine and DentistryUniversity of Western OntarioLondonONCanada
| | - Lilian Esene
- Department of Medical BiophysicsSchulich School of Medicine and DentistryUniversity of Western OntarioLondonONCanada
| | - Mohamed Adam
- Division of CardiologyKeenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's HospitalTorontoONCanada
- Institute of Medical ScienceUniversity of TorontoTorontoONCanada
| | - Antoinette Bugyei‐Twum
- Division of CardiologyKeenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's HospitalTorontoONCanada
- Institute of Medical ScienceUniversity of TorontoTorontoONCanada
| | - Elizabeth Mebrahtu
- Department of Medical BiophysicsSchulich School of Medicine and DentistryUniversity of Western OntarioLondonONCanada
| | - Jameela Joseph
- Department of Medical BiophysicsSchulich School of Medicine and DentistryUniversity of Western OntarioLondonONCanada
- Department of BiologyUniversity of Western OntarioLondonONCanada
| | - Mehroz Ehsan
- Department of Medical BiophysicsSchulich School of Medicine and DentistryUniversity of Western OntarioLondonONCanada
| | - Hao H. Chen
- Division of CardiologyKeenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's HospitalTorontoONCanada
- Institute of Medical ScienceUniversity of TorontoTorontoONCanada
| | - Mohammad Qadura
- Institute of Medical ScienceUniversity of TorontoTorontoONCanada
- Vascular SurgeryKeenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael’s HospitalTorontoONCanada
- Department of SurgeryUniversity of TorontoTorontoONCanada
| | - Krishna K. Singh
- Department of Medical BiophysicsSchulich School of Medicine and DentistryUniversity of Western OntarioLondonONCanada
- Anatomy and Cell BiologySchulich School of Medicine and DentistryUniversity of Western OntarioLondonONCanada
- Institute of Medical ScienceUniversity of TorontoTorontoONCanada
- Vascular SurgeryKeenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael’s HospitalTorontoONCanada
- Department of SurgeryUniversity of TorontoTorontoONCanada
- Pharmacology and ToxicologyUniversity of TorontoTorontoONCanada
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12
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Santana dos Santos E, Lallemand F, Petitalot A, Caputo SM, Rouleau E. HRness in Breast and Ovarian Cancers. Int J Mol Sci 2020; 21:E3850. [PMID: 32481735 PMCID: PMC7312125 DOI: 10.3390/ijms21113850] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 04/25/2020] [Accepted: 04/28/2020] [Indexed: 02/06/2023] Open
Abstract
Ovarian and breast cancers are currently defined by the main pathways involved in the tumorigenesis. The majority are carcinomas, originating from epithelial cells that are in constant division and subjected to cyclical variations of the estrogen stimulus during the female hormonal cycle, therefore being vulnerable to DNA damage. A portion of breast and ovarian carcinomas arises in the context of DNA repair defects, in which genetic instability is the backdrop for cancer initiation and progression. For these tumors, DNA repair deficiency is now increasingly recognized as a target for therapeutics. In hereditary breast/ovarian cancers (HBOC), tumors with BRCA1/2 mutations present an impairment of DNA repair by homologous recombination (HR). For many years, BRCA1/2 mutations were only screened on germline DNA, but now they are also searched at the tumor level to personalize treatment. The reason of the inactivation of this pathway remains uncertain for most cases, even in the presence of a HR-deficient signature. Evidence indicates that identifying the mechanism of HR inactivation should improve both genetic counseling and therapeutic response, since they can be useful as new biomarkers of response.
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Affiliation(s)
- Elizabeth Santana dos Santos
- Department of Medical Biology and Pathology, Gustave Roussy, Cancer Genetics Laboratory, Gustave Roussy, 94800 Villejuif, France;
- Department of Clinical Oncology, A.C. Camargo Cancer Center, São Paulo 01509-010, Brazil
| | - François Lallemand
- Department of Genetics, Institut Curie, 75005 Paris, France; (F.L.); (A.P.); (S.M.C.)
- PSL Research University, 75005 Paris, France
| | - Ambre Petitalot
- Department of Genetics, Institut Curie, 75005 Paris, France; (F.L.); (A.P.); (S.M.C.)
- PSL Research University, 75005 Paris, France
| | - Sandrine M. Caputo
- Department of Genetics, Institut Curie, 75005 Paris, France; (F.L.); (A.P.); (S.M.C.)
- PSL Research University, 75005 Paris, France
| | - Etienne Rouleau
- Department of Medical Biology and Pathology, Gustave Roussy, Cancer Genetics Laboratory, Gustave Roussy, 94800 Villejuif, France;
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13
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Zhang YX, Pan WY, Chen J. p53 and its isoforms in DNA double-stranded break repair. J Zhejiang Univ Sci B 2019; 20:457-466. [PMID: 31090271 DOI: 10.1631/jzus.b1900167] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
DNA double-stranded break (DSB) is one of the most catastrophic damages of genotoxic insult. Inappropriate repair of DNA DSBs results in the loss of genetic information, mutation, and the generation of harmful genomic rearrangements, which predisposes an organism to immunodeficiency, neurological damage, and cancer. The tumor repressor p53 plays a key role in DNA damage response, and has been found to be mutated in 50% of human cancer. p53, p63, and p73 are three members of the p53 gene family. Recent discoveries have shown that human p53 gene encodes at least 12 isoforms. Different p53 members and isoforms play various roles in orchestrating DNA damage response to maintain genomic integrity. This review briefly explores the functions of p53 and its isoforms in DNA DSB repair.
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Affiliation(s)
- Yu-Xi Zhang
- MOE Key Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Wen-Ya Pan
- MOE Key Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Jun Chen
- MOE Key Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
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14
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Gorodetska I, Kozeretska I, Dubrovska A. BRCA Genes: The Role in Genome Stability, Cancer Stemness and Therapy Resistance. J Cancer 2019; 10:2109-2127. [PMID: 31205572 PMCID: PMC6548160 DOI: 10.7150/jca.30410] [Citation(s) in RCA: 113] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 02/20/2019] [Indexed: 12/14/2022] Open
Abstract
Carcinogenesis is a multistep process, and tumors frequently harbor multiple mutations regulating genome integrity, cell division and death. The integrity of cellular genome is closely controlled by the mechanisms of DNA damage signaling and DNA repair. The association of breast cancer susceptibility genes BRCA1 and BRCA2 with breast and ovarian cancer development was first demonstrated over 20 years ago. Since then the germline mutations within these genes were linked to genomic instability and increased risk of many other cancer types. Genomic instability is an engine of the oncogenic transformation of non-tumorigenic cells into tumor-initiating cells and further tumor evolution. In this review we discuss the biological functions of BRCA1 and BRCA2 genes and the role of BRCA mutations in tumor initiation, regulation of cancer stemness, therapy resistance and tumor progression.
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Affiliation(s)
- Ielizaveta Gorodetska
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden and Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - Iryna Kozeretska
- Department of General and Medical Genetics, ESC "The Institute of Biology and Medicine", Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
| | - Anna Dubrovska
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Germany; Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany; German Cancer Consortium (DKTK), Partner site Dresden, Germany; German Cancer Research Center (DKFZ), Heidelberg, Germany
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15
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Xia Y, Du Z, Wang X, Li X. Treatment of Uterine Sarcoma with rAd-p53 (Gendicine) Followed by Chemotherapy: Clinical Study of TP53 Gene Therapy. Hum Gene Ther 2019; 29:242-250. [PMID: 29281902 DOI: 10.1089/hum.2017.206] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
This study evaluated the efficacy of rAd-p53 (Gendicine®) followed by chemotherapy for the treatment of uterine sarcoma. Twelve cases of uterine sarcoma treated at Shengjing Hospital were retrospectively analyzed. Among the 12 patients, one had primary cancer, and 11 had recurrent cancer. For the recurrent cases, the interval between the first operation and diagnosis of recurrence, or progression-free survival time 1 (PFS1), was 1-18 months (median 3 months). All patients were treated with local application of rAd-p53 followed by chemotherapy (local injection of bleomycin and i.v. infusion of cisplatin, epirubicin, and isocyclophosphamide). Efficacy was evaluated, and the rates of complete remission (CR) and partial remission (PR) were calculated. During follow-up, PFS time 2 (PFS2) after the baseline period and overall survival (OS) time after the baseline period of rAd-p53 treatment data were obtained. The treatment resulted in one CR, seven PR, three with stable disease (SD), and one with progressive disease (PD). The remission rate (CR + PR) was 66.7%, and the responsive (CR + PR + SD) rate was 91.7%. PFS2 ranged from 2 to 62 months, with a median of 13 months, which is 10 months longer than that of PFS1; this difference was statistically significant (p = 0.0038). The OS time ranged from 6 to 62 months, with a median of 24 months. Following the combined treatment, four of the patients underwent a second debulking surgery. Of the two patients with liver metastases, one had CR of liver foci, and one had PR. Up to the follow-up date of the two patients who survived, one was tumor-free for 60 months. The PFS2 for the other patient was 39 months. This patient survived with tumor for 53 months with slow disease progression. The remaining 10 patients died. Local application of rAd-p53 combined with local injection of bleomycin and intravenous infusion of cisplatin, epirubicin and isocyclophosphamide was effective for treatment of uterine sarcoma, especially for patients with liver metastases. For patients with uterine sarcoma who do not have the opportunity for surgery, this regimen can be used as a new adjuvant therapy to obtain a surgical opportunity that allows further debulking of the tumor mass.
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Affiliation(s)
- Yu Xia
- Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University , Shenyang, China
| | - Zhenhua Du
- Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University , Shenyang, China
| | - Xinyan Wang
- Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University , Shenyang, China
| | - Xiuqin Li
- Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University , Shenyang, China
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16
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De Silva S, Tennekoon KH, Karunanayake EH. Overview of the genetic basis toward early detection of breast cancer. BREAST CANCER-TARGETS AND THERAPY 2019; 11:71-80. [PMID: 30718964 PMCID: PMC6345186 DOI: 10.2147/bctt.s185870] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Cancer is a socioeconomical burden in any nation. Out of that, breast cancer is identified as the most common malignancy worldwide among women irrespective of age. As women are an important segment in a community, the weakening of their strength toward the development of a nation is a critical problem in each nation. In this review, it was aimed to discuss the characteristics of cancer genome, cancer genetics, and cancer epigenetics in general and then focus on discussing both genetic and nongenetic factors responsible for the predisposition of breast cancer in humans. More emphasis was placed on genes responsible for the early onset of the disease and which can be used as genetic tools in the identification of the disease at an early stage. Then the context of genetic involvement toward the breast cancer occurrence before age of 40 years was highlighted accordingly. In addition to genetic testing, the review paid adequate attention to mention novel liquid biopsy techniques and other clinical, laboratory, and radiologic assessments. These techniques can be used in early detection and recurrence as well as the surveillance of the patients after primary therapies.
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Affiliation(s)
- Sumadee De Silva
- Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, Colombo, Sri Lanka,
| | - Kamani Hemamala Tennekoon
- Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, Colombo, Sri Lanka,
| | - Eric Hamilton Karunanayake
- Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, Colombo, Sri Lanka,
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17
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Benítez-Burraco A. Differences in the Neanderthal BRCA2 gene might be related to their distinctive cognitive profile. Hereditas 2018; 155:38. [PMID: 30564067 PMCID: PMC6291940 DOI: 10.1186/s41065-018-0076-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 11/28/2018] [Indexed: 11/23/2022] Open
Abstract
The unique divergence of the BRCA2 gene in Neanderthals compared to modern humans has been hypothesized to account for a differential susceptibility to cancer. However, the role of the gene in brain development and its connection with autism suggest that these differences might be (also) related to the more encapsulated nature of the Neanderthal cognition and their (inferred) autistic-like features.
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Affiliation(s)
- Antonio Benítez-Burraco
- Department of Spanish, Linguistics, and Theory of Literature (Linguistics), University of Seville, Seville, Spain
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18
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Assessment of DNA repair susceptibility genes identified by whole exome sequencing in head and neck cancer. DNA Repair (Amst) 2018; 66-67:50-63. [PMID: 29747023 DOI: 10.1016/j.dnarep.2018.04.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 04/24/2018] [Accepted: 04/24/2018] [Indexed: 12/31/2022]
Abstract
Head and neck cancer (HNC), the sixth most common cancer globally, stands second in India. In Northeast (NE) India, it is the sixth most common cause of death in males and seventh in females. Prolonged tobacco and alcohol consumption constitute the major etiological factors for HNC development, which induce DNA damage. Therefore, DNA repair pathway is a crucial system in maintaining genomic integrity and preventing carcinogenesis. The present work was aimed to predict the consequence of significant germline variants of the DNA repair genes in disease predisposition. Whole exome sequencing was performed in Ion Proton™ platform on 15 case-control samples from the HNC-prevalent states of Manipur, Mizoram, and Nagaland. Variant annotation was done in Ion Reporter™ as well as wANNOVAR. Subsequent statistical and bioinformatics analysis identified significant exonic and intronic variants associated with HNC. Amongst our observed variants, 78.6% occurred in ExAC, 94% reported in dbSNP and 5.8% & 9.3% variants were present in ClinVar and HGMD, respectively. The total variants were dispersed among 199 genes with DSBR and FA pathway being the most mutated pathways. The allelic association test suggested that the intronic variants in HLTF and RAD52 gene significantly associated (P < 0.05) with the risk (OR > 5), while intronic variants in PARP4, RECQL5, EXO1 and PER1 genes and exonic variant in TDP2 gene showed protection (OR < 1) for HNC. MDR analysis proposed the exonic variants in MSH6, BRCA2, PALB2 and TP53 genes and intronic variant in RECQL5 genetic region working together during certain phase of DNA repair mechanism for HNC causation. In addition, other intronic and 3'UTR variations caused modifications in the transcription factor binding sites and miRNA target sites associated with HNC. Large-scale validation in NE Indian population, in-depth structure prediction and subsequent simulation of our recognized polymorphisms is necessary to identify true causal variants related to HNC.
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19
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Maifrede S, Martin K, Podszywalow-Bartnicka P, Sullivan-Reed K, Langer SK, Nejati R, Dasgupta Y, Hulse M, Gritsyuk D, Nieborowska-Skorska M, Lupey-Green LN, Zhao H, Piwocka K, Wasik MA, Tempera I, Skorski T. IGH/MYC Translocation Associates with BRCA2 Deficiency and Synthetic Lethality to PARP1 Inhibitors. Mol Cancer Res 2017. [PMID: 28634224 DOI: 10.1158/1541-7786.mcr-16-0468] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Burkitt lymphoma/leukemia cells carry t(8;14)(q24;q32) chromosomal translocation encoding IGH/MYC, which results in the constitutive expression of the MYC oncogene. Here, it is demonstrated that untreated and cytarabine (AraC)-treated IGH/MYC-positive Burkitt lymphoma cells accumulate a high number of potentially lethal DNA double-strand breaks (DSB) and display low levels of the BRCA2 tumor suppressor protein, which is a key element of homologous recombination (HR)-mediated DSB repair. BRCA2 deficiency in IGH/MYC-positive cells was associated with diminished HR activity and hypersensitivity to PARP1 inhibitors (olaparib, talazoparib) used alone or in combination with cytarabine in vitro Moreover, talazoparib exerted a therapeutic effect in NGS mice bearing primary Burkitt lymphoma xenografts. In conclusion, IGH/MYC-positive Burkitt lymphoma/leukemia cells have decreased BRCA2 and are sensitive to PARP1 inhibition alone or in combination with other chemotherapies.Implications: This study postulates that IGH/MYC-induced BRCA2 deficiency may predispose Burkitt lymphoma cells to synthetic lethality triggered by PARP1 inhibitors.Visual Overview: http://mcr.aacrjournals.org/content/molcanres/15/8/967/F1.large.jpgMol Cancer Res; 15(8); 967-72. ©2017 AACR.
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Affiliation(s)
- Silvia Maifrede
- Department of Microbiology and Immunology, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania
| | - Kayla Martin
- Fels Institute for Cancer Research and Molecular Biology, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania
| | - Paulina Podszywalow-Bartnicka
- Department of Microbiology and Immunology, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania.,Laboratory of Cytometry, Nencki Institute of Experimental Biology, Warsaw, Poland
| | - Katherine Sullivan-Reed
- Department of Microbiology and Immunology, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania
| | - Samantha K Langer
- Department of Microbiology and Immunology, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania
| | - Reza Nejati
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Yashodhara Dasgupta
- Department of Microbiology and Immunology, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania
| | - Michael Hulse
- Fels Institute for Cancer Research and Molecular Biology, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania
| | - Daniel Gritsyuk
- Department of Microbiology and Immunology, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania
| | - Margaret Nieborowska-Skorska
- Department of Microbiology and Immunology, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania
| | - Lena N Lupey-Green
- Fels Institute for Cancer Research and Molecular Biology, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania
| | - Huaqing Zhao
- Temple University Lewis Katz School of Medicine, Department of Clinical Sciences, Philadelphia, Pennsylvania
| | - Katarzyna Piwocka
- Laboratory of Cytometry, Nencki Institute of Experimental Biology, Warsaw, Poland
| | - Mariusz A Wasik
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Italo Tempera
- Fels Institute for Cancer Research and Molecular Biology, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania.
| | - Tomasz Skorski
- Department of Microbiology and Immunology, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania. .,Fels Institute for Cancer Research and Molecular Biology, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania
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20
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21
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Song X, Shi Q, Liu Z, Wang Y, Wang Y, Song E, Song Y. Unpredicted Downregulation of RAD51 Suggests Genome Instability Induced by Tetrachlorobenzoquinone. Chem Res Toxicol 2016; 29:2184-2193. [DOI: 10.1021/acs.chemrestox.6b00369] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Xiufang Song
- Key Laboratory of Luminescence
and Real-Time Analytical Chemistry (Southwest University), Ministry
of Education, College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, People’s Republic of China
| | - Qiong Shi
- Key Laboratory of Luminescence
and Real-Time Analytical Chemistry (Southwest University), Ministry
of Education, College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, People’s Republic of China
| | - Zixuan Liu
- Key Laboratory of Luminescence
and Real-Time Analytical Chemistry (Southwest University), Ministry
of Education, College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, People’s Republic of China
| | - Yawen Wang
- Key Laboratory of Luminescence
and Real-Time Analytical Chemistry (Southwest University), Ministry
of Education, College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, People’s Republic of China
| | - Yuxin Wang
- Key Laboratory of Luminescence
and Real-Time Analytical Chemistry (Southwest University), Ministry
of Education, College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, People’s Republic of China
| | - Erqun Song
- Key Laboratory of Luminescence
and Real-Time Analytical Chemistry (Southwest University), Ministry
of Education, College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, People’s Republic of China
| | - Yang Song
- Key Laboratory of Luminescence
and Real-Time Analytical Chemistry (Southwest University), Ministry
of Education, College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, People’s Republic of China
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22
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Ma H, Song T, Wang T, Wang S. Influence of Human p53 on Plant Development. PLoS One 2016; 11:e0162840. [PMID: 27648563 PMCID: PMC5029891 DOI: 10.1371/journal.pone.0162840] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 08/29/2016] [Indexed: 11/19/2022] Open
Abstract
Mammalian p53 is a super tumor suppressor and plays a key role in guarding genome from DNA damage. However, p53 has not been found in plants which do not bear cancer although they constantly expose to ionizing radiation of ultraviolet light. Here we introduced p53 into the model plant Arabidopsis and examined p53-conferred phenotype in plant. Most strikingly, p53 caused early senescence and fasciation. In plants, fasciation has been shown as a result of the elevated homologous DNA recombination. Consistently, a reporter with overlapping segments of the GUS gene (1445) showed that the frequency of homologous recombination was highly induced in p53-transgenic plants. In contrast to p53, SUPPRESSOR OF NPR1-1 INDUCIBLE 1 (SNI1), as a negative regulator of homologous recombination in plants, is not present in mammals. Comet assay and clonogenic survival assay demonstrated that SNI1 inhibited DNA damage repair caused by either ionizing radiation or hydroxyurea in human osteosarcoma U2OS cancer cells. RAD51D is a recombinase in homologous recombination and functions downstream of SNI1 in plants. Interestingly, p53 rendered the sni1 mutants madly branching of inflorescence, a phenotype of fasciation, whereas rad51d mutant fully suppressed the p53-induced phenotype, indicating that human p53 action in plant is mediated by the SNI1-RAD51D signaling pathway. The reciprocal species-swap tests of p53 and SNI1 in human and Arabidopsis manifest that these species-specific proteins play a common role in homologous recombination across kingdoms of animals and plants.
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Affiliation(s)
- Huimin Ma
- Development Center of Plant Germplasm Resources, College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Teng Song
- Development Center of Plant Germplasm Resources, College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Tianhua Wang
- Development Center of Plant Germplasm Resources, College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Shui Wang
- Development Center of Plant Germplasm Resources, College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China
- * E-mail:
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23
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Malik S, Saito H, Takaoka M, Miki Y, Nakanishi A. BRCA2 mediates centrosome cohesion via an interaction with cytoplasmic dynein. Cell Cycle 2016; 15:2145-2156. [PMID: 27433848 PMCID: PMC4993541 DOI: 10.1080/15384101.2016.1195531] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BRCA2 is responsible for familial breast and ovarian cancer and has been linked to DNA repair and centrosome duplication. Here we analyzed the mechanism by which the centrosomal localization signal (CLS) of BRCA2 interacts with cytoplasmic dynein 1 to localize BRCA2 to the centrosome. In vitro pull-down assays demonstrated that BRCA2 directly binds to the cytoplasmic dynein 1 light intermediate chain 2. A dominant-negative HA-CLS-DsRed fusion protein, the depletion of dynein by siRNA, and the inactivation of dynein by EHNA, inhibited the localization of BRCA2 at centrosomes and caused the separation of centrosome pairs during the S-phase. The double depletion of BRCA2 and C-Nap1 caused a larger dispersion of centrosome distances than the silencing of C-Nap1. These results suggest that cytoplasmic dynein 1 binds to BRCA2 through the latter's CLS and BRCA2 mediates the cohesion between centrosomes during the S phase, potentially serving as a cell-cycle checkpoint.
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Affiliation(s)
- Sadiya Malik
- a Department of Molecular Genetics , Medical Research Institute, Tokyo Medical and Dental University , Tokyo , Japan
| | - Hiroko Saito
- b Department of Genetic Diagnosis , The Cancer Institute, Japanese Foundation for Cancer Research , Tokyo , Japan
| | - Miho Takaoka
- a Department of Molecular Genetics , Medical Research Institute, Tokyo Medical and Dental University , Tokyo , Japan
| | - Yoshio Miki
- a Department of Molecular Genetics , Medical Research Institute, Tokyo Medical and Dental University , Tokyo , Japan.,b Department of Genetic Diagnosis , The Cancer Institute, Japanese Foundation for Cancer Research , Tokyo , Japan
| | - Akira Nakanishi
- a Department of Molecular Genetics , Medical Research Institute, Tokyo Medical and Dental University , Tokyo , Japan
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24
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The p53-like Protein CEP-1 Is Required for Meiotic Fidelity in C. elegans. Curr Biol 2016; 26:1148-58. [PMID: 27151662 DOI: 10.1016/j.cub.2016.03.036] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 02/05/2016] [Accepted: 03/14/2016] [Indexed: 11/21/2022]
Abstract
The passage of genetic information during meiosis requires exceptionally high fidelity to prevent birth defects and infertility. Accurate chromosome segregation during the first meiotic division relies on the formation of crossovers between homologous chromosomes and a series of precisely controlled steps to exchange genetic information. Many studies have hinted at a role for p53 in meiosis, but how it functions in this process is poorly understood. Here, we have identified a cooperative role for the p53-like protein CEP-1 and the meiotic protein HIM-5 in maintaining genome stability in the C. elegans germline. Loss of cep-1 and him-5 results in synthetic lethality that is dependent on the upstream DNA damage checkpoint but independent of the downstream core apoptotic pathway. We show that this synthetic lethality is the result of defective crossover formation due to reduced SPO-11-dependent double-strand breaks. Using cep-1 separation-of-function alleles, we show that cep-1 and him-5 also suppress inappropriate activation of the nonhomologous end joining (NHEJ) pathway. This work reveals an ancestral function for the p53 family in ensuring the fidelity of meiosis and establishes CEP-1 as a critical determinant of repair pathway choice.
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Wang Z, Liu Y, Lu L, Yang L, Yin S, Wang Y, Qi Z, Meng J, Zang R, Yang G. Fibrillin-1, induced by Aurora-A but inhibited by BRCA2, promotes ovarian cancer metastasis. Oncotarget 2016; 6:6670-83. [PMID: 25749384 PMCID: PMC4466642 DOI: 10.18632/oncotarget.3118] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 01/08/2015] [Indexed: 11/25/2022] Open
Abstract
While Aurora-A (Aur A) provokes, BRCA2 restrains primary tumorigenesis, the roles of Aur A and BRCA2 in cancer metastasis remains unclear. Here, we show that the metastatic promoting markers SLUG, FBN1, and MMP2, 9, 13 are either stimulated or suppressed by Aur A or BRCA2, but the metastatic suppressors E-cadherin, β-catenin, and p53 are either inhibited or promoted by Aur A or BRCA2, leading to enhanced or reduced cell migration and invasion. Further study suggests that FBN1 inhibits E-cadherin and β-catenin, but stimulates MMP2, 9, 13. Depletion of SLUG abrogates FBN1 and MMP9, but increases E-cadherin, while p53 decreases both SLUG and FBN1. Animal assays demonstrate that FBN1 promotes both ovarian tumorigenesis and metastasis. Clinically, overexpression of BRCA2 or Aur A in ovarian cancer tissues predicts good or poor overall and disease free survivals. High expression of SLUG or FBN1 indicates poor overall survivals, whereas high expression of FBN1 but not of SLUG predicts poor disease free survival. No significant associations between p53 expression and patient survivals were found. Overall, FBN1, acts at the downstream of Aur A and BRCA2, promotes ovarian cancer metastasis through the p53 and SLUG-associated signaling, which may be useful for ovarian cancer diagnosis and treatment.
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Affiliation(s)
- Ziliang Wang
- Cancer Institute, Fudan University Shanghai Cancer Center, Shanghai 200032, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Yang Liu
- Department of Gynecological Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Lili Lu
- Department of Biology, Life and Environment Science College, Shanghai Normal University, Shanghai 200023, China
| | - Lina Yang
- Cancer Institute, Fudan University Shanghai Cancer Center, Shanghai 200032, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Sheng Yin
- Department of Gynecological Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Yan Wang
- Cancer Institute, Fudan University Shanghai Cancer Center, Shanghai 200032, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Zihao Qi
- Cancer Institute, Fudan University Shanghai Cancer Center, Shanghai 200032, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Jiao Meng
- Cancer Institute, Fudan University Shanghai Cancer Center, Shanghai 200032, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Rongyu Zang
- Department of Gynecological Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Gong Yang
- Cancer Institute, Fudan University Shanghai Cancer Center, Shanghai 200032, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China.,Central Laboratory, the Fifth People's Hospital of Shanghai Fudan University, Shanghai 200240, China
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Chang CH, Zhang M, Rajapakshe K, Coarfa C, Edwards D, Huang S, Rosen JM. Mammary Stem Cells and Tumor-Initiating Cells Are More Resistant to Apoptosis and Exhibit Increased DNA Repair Activity in Response to DNA Damage. Stem Cell Reports 2015; 5:378-91. [PMID: 26300228 PMCID: PMC4618454 DOI: 10.1016/j.stemcr.2015.07.009] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Revised: 07/22/2015] [Accepted: 07/23/2015] [Indexed: 01/05/2023] Open
Abstract
Adult stem cells and tumor-initiating cells (TICs) often employ different mechanisms of DNA damage response (DDR) as compared to other tissue cell types. However, little is known about how mammary stem cells (MaSCs) and mammary TICs respond to DNA damage. Using the mouse mammary gland and syngeneic p53-null tumors as models, we investigated the molecular and physiological consequences of DNA damage in wild-type MaSCs, p53-null MaSCs, and p53-null TICs. We showed that wild-type MaSCs and basal cells are more resistant to apoptosis and exhibit increased non-homologous end joining (NHEJ) activity. Loss of p53 in mammary epithelium affected both cell-cycle regulation and DNA repair efficiency. In p53-null tumors, we showed that TICs are more resistant to ionizing radiation (IR) due to decreased apoptosis, elevated NHEJ activity, and more-rapid DNA repair. These results have important implications for understanding DDR mechanisms involved in both tumorigenesis and therapy resistance. MaSCs are more resistant to apoptosis and exhibit increased NHEJ activity Loss of p53 in MECs impairs cell-cycle regulation and DNA repair efficiency TICs exhibit decreased apoptosis, increased DNA repair efficiency, and NHEJ activity TICs are highly proliferative and exhibit improper cell-cycle regulation after IR
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Affiliation(s)
- Chi-Hsuan Chang
- Integrative Molecular and Biomedical Sciences Graduate Program, Baylor College of Medicine, Houston, TX 77030, USA
| | - Mei Zhang
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Kimal Rajapakshe
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Cristian Coarfa
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Dean Edwards
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Shixia Huang
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jeffrey M Rosen
- Integrative Molecular and Biomedical Sciences Graduate Program, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA.
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Zhong X, Luo G, Zhou X, Luo W, Wu X, Zhong R, Wang Y, Xu F, Wang J. Rad51 in regulating the radiosensitivity of non-small cell lung cancer with different epidermal growth factor receptor mutation status. Thorac Cancer 2015; 7:50-60. [PMID: 26816539 PMCID: PMC4718133 DOI: 10.1111/1759-7714.12274] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Accepted: 04/12/2015] [Indexed: 02/05/2023] Open
Abstract
Background Non‐small cell lung cancer (NSCLC) harboring kinase‐domain mutations in epidermal growth factor receptors (EGFR) has been observed to be sensitive to ionizing radiation (IR). We explore Rad51‐dependent homologous recombination (HR) DNA repair in regulating radiosensitivity in two NSCLC cell lines with different EGFR mutation status. Methods NSCLC cell lines, wild‐type EGFR A549 and mutant EGFR H820 with an in‐frame deletion in exon 19 of EGFR (ΔE746–E750), were cultured. Radiosensitivity was estimated by colony forming assay. Rad51 expression was evaluated by quantitative real time‐polymerase chain reaction and Western‐blot. Lentiviral small hairpin ribonucleic acid‐Rad51 and ΔE746–E750 deletion mutant EGFR were constructed and transfected into cells. Flowcytometry assay was used to analyze DNA double strand breaks, cell cycle alterations, and apoptosis. Results A549 had a higher survival factor (SF)2 (0.66 vs. 0.44) and lower α/β value (4.07 vs. 9.01). Compared with the A549 cell, the H820 cell exhibited defective arrest in the S‐phase, a higher rate of G2/M accumulation, early apoptosis, and residual γ‐H2AX. Downregulated Rad51 expression decreased SF2 (0.42 vs. 0.31) and increased the α/β ratio (7.51 vs. 10.5), G2/M accumulation, early apoptosis, and γ‐H2AX in two cell lines. H820 had a low IR‐induced Rad51 expression and nuclear translocation. Exogenous expression of the ΔE746–E750 deletion mutant EGFR caused the A549 cell to become more radiosensitive. Conclusions An EGFR mutated NSCLC cell line is sensitive to IR, which is correlated with reduced IR‐induced Rad51 expression and nuclear translocation. The signaling pathway of EGFR maintaining Rad51 protein levels maybe a novel lung cancer therapeutic target to overcome radioresistance.
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Affiliation(s)
- Xing Zhong
- Thoracic Oncology West China Hospital Sichuan University Chengdu China; State Key Laboratory of Biotherapy West China Hospital Sichuan University Chengdu China
| | - Guomin Luo
- Thoracic Oncology West China Hospital Sichuan University Chengdu China; State Key Laboratory of Biotherapy West China Hospital Sichuan University Chengdu China
| | - Xiaojuan Zhou
- Thoracic Oncology West China Hospital Sichuan University Chengdu China; State Key Laboratory of Biotherapy West China Hospital Sichuan University Chengdu China
| | - Wen Luo
- Thoracic Oncology West China Hospital Sichuan University Chengdu China; State Key Laboratory of Biotherapy West China Hospital Sichuan University Chengdu China
| | - Xia Wu
- Thoracic Oncology West China Hospital Sichuan University Chengdu China; State Key Laboratory of Biotherapy West China Hospital Sichuan University Chengdu China
| | - Renming Zhong
- State Key Laboratory of Biotherapy West China Hospital Sichuan University Chengdu China
| | - Yanping Wang
- Laboratory of Molecular Diagnosis of Cancer West China Hospital Sichuan University Chengdu China
| | - Feng Xu
- State Key Laboratory of Biotherapy West China Hospital Sichuan University Chengdu China; Abdominal oncology West China Hospital Sichuan University Chengdu China
| | - Jin Wang
- Thoracic Oncology West China Hospital Sichuan University Chengdu China; State Key Laboratory of Biotherapy West China Hospital Sichuan University Chengdu China
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Genomic analysis of ADAR1 binding and its involvement in multiple RNA processing pathways. Nat Commun 2015; 6:6355. [PMID: 25751603 PMCID: PMC4355961 DOI: 10.1038/ncomms7355] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 01/22/2015] [Indexed: 12/15/2022] Open
Abstract
Adenosine deaminases acting on RNA (ADARs) are the primary factors underlying adenosine to inosine (A-to-I) editing in metazoans. Here we report the first global study of ADAR1-RNA interaction in human cells using CLIP-Seq. A large number of CLIP sites are observed in Alu repeats, consistent with ADAR1's function in RNA editing. Surprisingly, thousands of other CLIP sites are located in non-Alu regions, revealing functional and biophysical targets of ADAR1 in the regulation of alternative 3' UTR usage and miRNA biogenesis. We observe that binding of ADAR1 to 3' UTRs precludes binding by other factors, causing 3' UTR lengthening. Similarly, ADAR1 interacts with DROSHA and DGCR8 in the nucleus and possibly out-competes DGCR8 in primary miRNA binding, which enhances mature miRNA expression. These functions are dependent on ADAR1's editing activity, at least for a subset of targets. Our study unfolds a broad landscape of the functional roles of ADAR1.
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Liu T, Huang J. Quality control of homologous recombination. Cell Mol Life Sci 2014; 71:3779-97. [PMID: 24858417 PMCID: PMC11114062 DOI: 10.1007/s00018-014-1649-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 05/09/2014] [Indexed: 12/21/2022]
Abstract
Exogenous and endogenous genotoxic agents, such as ionizing radiation and numerous chemical agents, cause DNA double-strand breaks (DSBs), which are highly toxic and lead to genomic instability or tumorigenesis if not repaired accurately and efficiently. Cells have over evolutionary time developed certain repair mechanisms in response to DSBs to maintain genomic integrity. Major DSB repair mechanisms include non-homologous end joining and homologous recombination (HR). Using sister homologues as templates, HR is a high-fidelity repair pathway that can rejoin DSBs without introducing mutations. However, HR execution without appropriate guarding may lead to more severe gross genome rearrangements. Here we review current knowledge regarding the factors and mechanisms required for accomplishment of accurate HR.
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Affiliation(s)
- Ting Liu
- Life Sciences Institute, Zhejiang University, Hangzhou, 310058 Zhejiang China
| | - Jun Huang
- Life Sciences Institute, Zhejiang University, Hangzhou, 310058 Zhejiang China
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30
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Wu M, Kwoh CK, Li X, Zheng J. Finding trans-regulatory genes and protein complexes modulating meiotic recombination hotspots of human, mouse and yeast. BMC SYSTEMS BIOLOGY 2014; 8:107. [PMID: 25208583 PMCID: PMC4236725 DOI: 10.1186/s12918-014-0107-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 07/11/2014] [Indexed: 11/18/2022]
Abstract
Background The regulatory mechanism of recombination is one of the most fundamental problems in genomics, with wide applications in genome wide association studies (GWAS), birth-defect diseases, molecular evolution, cancer research, etc. Recombination events cluster into short genomic regions called “recombination hotspots”. Recently, a zinc finger protein PRDM9 was reported to regulate recombination hotspots in human and mouse genomes. In addition, a 13-mer motif contained in the binding sites of PRDM9 is found to be enriched in human hotspots. However, this 13-mer motif only covers a fraction of hotspots, indicating that PRDM9 is not the only regulator of recombination hotspots. Therefore, the challenge of discovering other regulators of recombination hotspots becomes significant. Furthermore, recombination is a complex process. Hence, multiple proteins acting as machinery, rather than individual proteins, are more likely to carry out this process in a precise and stable manner. Therefore, the extension of the prediction of individual trans-regulators to protein complexes is also highly desired. Results In this paper, we introduce a pipeline to identify genes and protein complexes associated with recombination hotspots. First, we prioritize proteins associated with hotspots based on their preference of binding to hotspots and coldspots. Second, using the above identified genes as seeds, we apply the Random Walk with Restart algorithm (RWR) to propagate their influences to other proteins in protein-protein interaction (PPI) networks. Hence, many proteins without DNA-binding information will also be assigned a score to implicate their roles in recombination hotspots. Third, we construct sub-PPI networks induced by top genes ranked by RWR for various species (e.g., yeast, human and mouse) and detect protein complexes in those sub-PPI networks. Conclusions The GO term analysis show that our prioritizing methods and the RWR algorithm are capable of identifying novel genes associated with recombination hotspots. The trans-regulators predicted by our pipeline are enriched with epigenetic functions (e.g., histone modifications), demonstrating the epigenetic regulatory mechanisms of recombination hotspots. The identified protein complexes also provide us with candidates to further investigate the molecular machineries for recombination hotspots. Moreover, the experimental data and results are available on our web site http://www.ntu.edu.sg/home/zhengjie/data/RecombinationHotspot/NetPipe/.
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Abstract
PALB2 [partner and localizer of BRCA2 (breast cancer early-onset 2)] [corrected] has emerged as a key player in the maintenance of genome integrity. Biallelic mutations in PALB2 cause FA (Fanconi's anaemia) subtype FA-N, a devastating inherited disorder marked by developmental abnormalities, bone marrow failure and childhood cancer susceptibility, whereas monoallelic mutations predispose to breast, ovarian and pancreatic cancer. The tumour suppressor role of PALB2 has been intimately linked to its ability to promote HR (homologous recombination)-mediated repair of DNA double-strand breaks. Because PALB2 lies at the crossroads between FA, HR and cancer susceptibility, understanding its function has become the primary focus of several studies. The present review discusses a current synthesis of the contribution of PALB2 to these pathways. We also provide a molecular description of FA- or cancer-associated PALB2 mutations.
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32
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Wiedemeyer WR, Beach JA, Karlan BY. Reversing Platinum Resistance in High-Grade Serous Ovarian Carcinoma: Targeting BRCA and the Homologous Recombination System. Front Oncol 2014. [PMID: 24624361 DOI: 10.3389/fonc.2014.00034]+[] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Resistance to platinum chemotherapy is one of the main factors driving ovarian cancer mortality, and overcoming platinum resistance is considered one of the greatest challenges in ovarian cancer research. Genetic and functional evidence points to the homologous recombination (HR) DNA repair system, and BRCA1 and BRCA2 in particular, as main determinants of response to platinum therapy. BRCA-mutant ovarian cancers are especially sensitive to platinum, associated with better survival, and amenable to poly ADP ribose polymerase inhibitor treatment. Here, we discuss a therapeutic concept that seeks to disrupt HR capacity via targeting of BRCA1 and BRCA2 functionality in order to reverse platinum resistance in BRCA-proficient high-grade serous ovarian cancers (HGSOC). We review the molecular signaling pathways that converge on BRCA1 and BRCA2, their activation status in ovarian cancer, and therapeutic options to modulate BRCA function. Several recent publications demonstrate efficient chemosensitization of BRCA-proficient cancers by combining targeted therapy with standard platinum-based agents. Due to its inherent genomic heterogeneity, molecularly defined subgroups of HGSOC may require different approaches. We seek to provide an overview of available agents and their potential use to reverse platinum resistance by inhibiting the HR system, either directly or indirectly, by targeting oncogenic activators of HR.
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Affiliation(s)
- W Ruprecht Wiedemeyer
- Women's Cancer Program, Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center , Los Angeles, CA , USA ; Department of Obstetrics and Gynecology, David Geffen School of Medicine, University of California Los Angeles , Los Angeles, CA , USA
| | - Jessica A Beach
- Women's Cancer Program, Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center , Los Angeles, CA , USA ; Graduate Program in Biomedical Sciences and Translational Medicine, Cedars-Sinai Medical Center , Los Angeles, CA , USA
| | - Beth Y Karlan
- Women's Cancer Program, Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center , Los Angeles, CA , USA ; Department of Obstetrics and Gynecology, David Geffen School of Medicine, University of California Los Angeles , Los Angeles, CA , USA
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Wiedemeyer WR, Beach JA, Karlan BY. Reversing Platinum Resistance in High-Grade Serous Ovarian Carcinoma: Targeting BRCA and the Homologous Recombination System. Front Oncol 2014. [PMID: 24624361 DOI: 10.3389/fonc.2014.00034] [] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Resistance to platinum chemotherapy is one of the main factors driving ovarian cancer mortality, and overcoming platinum resistance is considered one of the greatest challenges in ovarian cancer research. Genetic and functional evidence points to the homologous recombination (HR) DNA repair system, and BRCA1 and BRCA2 in particular, as main determinants of response to platinum therapy. BRCA-mutant ovarian cancers are especially sensitive to platinum, associated with better survival, and amenable to poly ADP ribose polymerase inhibitor treatment. Here, we discuss a therapeutic concept that seeks to disrupt HR capacity via targeting of BRCA1 and BRCA2 functionality in order to reverse platinum resistance in BRCA-proficient high-grade serous ovarian cancers (HGSOC). We review the molecular signaling pathways that converge on BRCA1 and BRCA2, their activation status in ovarian cancer, and therapeutic options to modulate BRCA function. Several recent publications demonstrate efficient chemosensitization of BRCA-proficient cancers by combining targeted therapy with standard platinum-based agents. Due to its inherent genomic heterogeneity, molecularly defined subgroups of HGSOC may require different approaches. We seek to provide an overview of available agents and their potential use to reverse platinum resistance by inhibiting the HR system, either directly or indirectly, by targeting oncogenic activators of HR.
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Affiliation(s)
- W Ruprecht Wiedemeyer
- Women's Cancer Program, Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center , Los Angeles, CA , USA ; Department of Obstetrics and Gynecology, David Geffen School of Medicine, University of California Los Angeles , Los Angeles, CA , USA
| | - Jessica A Beach
- Women's Cancer Program, Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center , Los Angeles, CA , USA ; Graduate Program in Biomedical Sciences and Translational Medicine, Cedars-Sinai Medical Center , Los Angeles, CA , USA
| | - Beth Y Karlan
- Women's Cancer Program, Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center , Los Angeles, CA , USA ; Department of Obstetrics and Gynecology, David Geffen School of Medicine, University of California Los Angeles , Los Angeles, CA , USA
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Protective role of miR-155 in breast cancer through RAD51 targeting impairs homologous recombination after irradiation. Proc Natl Acad Sci U S A 2014; 111:4536-41. [PMID: 24616504 DOI: 10.1073/pnas.1402604111] [Citation(s) in RCA: 152] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Cell survival after DNA damage relies on DNA repair, the abrogation of which causes genomic instability and development of cancer. However, defective DNA repair in cancer cells can be exploited for cancer therapy using DNA-damaging agents. DNA double-strand breaks are the major lethal lesions induced by ionizing radiation (IR) and can be efficiently repaired by DNA homologous recombination, a system that requires numerous factors including the recombinase RAD51 (RAD51). Therapies combined with adjuvant radiotherapy have been demonstrated to improve the survival of triple-negative breast cancer patients; however, such therapy is challenged by the emergence of resistance in tumor cells. It is, therefore, essential to develop novel therapeutic strategies to overcome radioresistance and improve radiosensitivity. In this study we show that overexpression of microRNA 155 (miR-155) in human breast cancer cells reduces the levels of RAD51 and affects the cellular response to IR. miR-155 directly targets the 3'-untranslated region of RAD51. Overexpression of miR-155 decreased the efficiency of homologous recombination repair and enhanced sensitivity to IR in vitro and in vivo. High miR-155 levels were associated with lower RAD51 expression and with better overall survival of patients in a large series of triple-negative breast cancers. Taken together, our findings indicate that miR-155 regulates DNA repair activity and sensitivity to IR by repressing RAD51 in breast cancer. Testing for expression levels of miR-155 may be useful in the identification of breast cancer patients who will benefit from an IR-based therapeutic approach.
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Wiedemeyer WR, Beach JA, Karlan BY. Reversing Platinum Resistance in High-Grade Serous Ovarian Carcinoma: Targeting BRCA and the Homologous Recombination System. Front Oncol 2014; 4:34. [PMID: 24624361 PMCID: PMC3939430 DOI: 10.3389/fonc.2014.00034] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 02/11/2014] [Indexed: 11/26/2022] Open
Abstract
Resistance to platinum chemotherapy is one of the main factors driving ovarian cancer mortality, and overcoming platinum resistance is considered one of the greatest challenges in ovarian cancer research. Genetic and functional evidence points to the homologous recombination (HR) DNA repair system, and BRCA1 and BRCA2 in particular, as main determinants of response to platinum therapy. BRCA-mutant ovarian cancers are especially sensitive to platinum, associated with better survival, and amenable to poly ADP ribose polymerase inhibitor treatment. Here, we discuss a therapeutic concept that seeks to disrupt HR capacity via targeting of BRCA1 and BRCA2 functionality in order to reverse platinum resistance in BRCA-proficient high-grade serous ovarian cancers (HGSOC). We review the molecular signaling pathways that converge on BRCA1 and BRCA2, their activation status in ovarian cancer, and therapeutic options to modulate BRCA function. Several recent publications demonstrate efficient chemosensitization of BRCA-proficient cancers by combining targeted therapy with standard platinum-based agents. Due to its inherent genomic heterogeneity, molecularly defined subgroups of HGSOC may require different approaches. We seek to provide an overview of available agents and their potential use to reverse platinum resistance by inhibiting the HR system, either directly or indirectly, by targeting oncogenic activators of HR.
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Affiliation(s)
- W Ruprecht Wiedemeyer
- Women's Cancer Program, Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center , Los Angeles, CA , USA ; Department of Obstetrics and Gynecology, David Geffen School of Medicine, University of California Los Angeles , Los Angeles, CA , USA
| | - Jessica A Beach
- Women's Cancer Program, Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center , Los Angeles, CA , USA ; Graduate Program in Biomedical Sciences and Translational Medicine, Cedars-Sinai Medical Center , Los Angeles, CA , USA
| | - Beth Y Karlan
- Women's Cancer Program, Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center , Los Angeles, CA , USA ; Department of Obstetrics and Gynecology, David Geffen School of Medicine, University of California Los Angeles , Los Angeles, CA , USA
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Jensen RB. BRCA2: one small step for DNA repair, one giant protein purified. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 2013; 86:479-89. [PMID: 24348212 PMCID: PMC3848102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
DNA damage, malfunctions in DNA repair, and genomic instability are processes that intersect at the crossroads of carcinogenesis. Underscoring the importance of DNA repair in breast and ovarian tumorigenesis is the familial inherited cancer predisposition gene BRCA2. The role of BRCA2 in DNA double-strand break repair was first revealed based on its interaction with RAD51, a central player in homologous recombination. The RAD51 protein forms a nucleoprotein filament on single-stranded DNA, invades a DNA duplex, and initiates a search for homology. Once a homologous DNA sequence is found, the DNA is used as a template for the high-fidelity repair of the DNA break. Many of the biochemical features that allow BRCA2 to choreograph the activities of RAD51 have been elucidated and include: targeting RAD51 to single-stranded DNA while inhibiting binding to dsDNA, reducing the ATPase activity of RAD51, and facilitating the displacement of the single-strand DNA binding protein, Replication Protein A. These reinforcing activities of BRCA2 culminate in the correct positioning of RAD51 onto a processed DNA double-strand break and initiate its faithful repair by homologous recombination. In this review, I will address current biochemical data concerning the BRCA2 protein and highlight unanswered questions regarding BRCA2 function in homologous recombination and cancer.
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Magwood AC, Malysewich MJ, Cealic I, Mundia MM, Knapp J, Baker MD. Endogenous levels of Rad51 and Brca2 are required for homologous recombination and regulated by homeostatic re-balancing. DNA Repair (Amst) 2013; 12:1122-33. [PMID: 24210700 DOI: 10.1016/j.dnarep.2013.10.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 10/15/2013] [Indexed: 12/17/2022]
Abstract
Stable expression of Rad51 siRNA was used to generate mouse hybridoma cell lines in which endogenous Rad51 levels were depleted by as much as 60%. Stable Rad51 knockdowns feature reduced homologous recombination responses. The relative ease with which stable Rad51 knockdowns were recovered was surprising, given the embryonic lethality of Rad51 ablation. Interestingly, Rad51-depleted hybridoma cell lines are characterized by reduced levels of p53 protein. Completely unexpected, was the finding that Rad51-depleted hybridoma cell lines are also reduced for the breast cancer susceptibility 2 (Brca2) protein. Additionally, hybridoma cell lines that are siRNA depleted for mouse Brca2 show a corresponding reduction in Rad51 and p53 proteins. Furthermore, cellular levels of Rad51, Brca2 and p53 can be elevated in these cell lines by ectopic expression of wild-type human Rad51 and wild-type human BRCA2. In marked contrast, hybridoma cell lines that are siRNA depleted for mouse p53 feature relatively normal Rad51 and Brca2 levels. These results suggest that cellular levels of Brca2 and Rad51 are mutually dependent on each other, and that low levels of these proteins provide selective pressure for reduction of p53, which permits cell growth.
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Affiliation(s)
- Alissa C Magwood
- Department of Molecular and Cellular Biology, College of Biological Science, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
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38
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Verma S, Rao BJ. p53 suppresses BRCA2-stimulated ATPase and strand exchange functions of human RAD51. J Biochem 2013; 154:237-48. [PMID: 23678008 DOI: 10.1093/jb/mvt040] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Although homologous recombination (HR) is an important pathway for DNA repair, it can also be a cause for deleterious genomic rearrangements leading to carcinogenesis. Therefore, cells have evolved elaborate mechanisms to regulate HR, positively as well as negatively. Among many molecular components that regulate HR are tumour suppressors p53, a negative regulator and breast cancer early-onset (BRCA)2, a positive regulator. Both the players not only interact with each other but also directly interact with human RAD51 (hRAD51), the key recombinase in HR. Here, for the first time we studied HR regulation by the combined action of p53 and BRCA2, in vitro. While BRC4 peptide inhibits ATP hydrolysis by hRAD51, BRCA2(BRC1-8) stimulates DNA-independent and double-stranded DNA-dependent ATPase several fold and only marginally single-stranded DNA-dependent ATPase. Pull down assays demonstrated the occurrence of complex comprising of all three proteins and DNA, where p53 tends to compete out hRAD51 and BRCA2(BRC1-8), leading to not only the decline in ATP hydrolysis but also the strand exchange function of hRAD51 that was stimulated by BRCA2(BRC1-8). Our findings suggest a rigorous p53-mediated regulation on hRAD51 functions in HR even in the presence of BRCA2.
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Affiliation(s)
- Shalini Verma
- Department of Biological Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005, Maharashtra, India
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Andrade LNDS, Nathanson JL, Yeo GW, Menck CFM, Muotri AR. Evidence for premature aging due to oxidative stress in iPSCs from Cockayne syndrome. Hum Mol Genet 2012; 21:3825-34. [PMID: 22661500 DOI: 10.1093/hmg/dds211] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Cockayne syndrome (CS) is a human premature aging disorder associated with neurological and developmental abnormalities, caused by mutations mainly in the CS group B gene (ERCC6). At the molecular level, CS is characterized by a deficiency in the transcription-couple DNA repair pathway. To understand the role of this molecular pathway in a pluripotent cell and the impact of CSB mutation during human cellular development, we generated induced pluripotent stem cells (iPSCs) from CSB skin fibroblasts (CSB-iPSC). Here, we showed that the lack of functional CSB does not represent a barrier to genetic reprogramming. However, iPSCs derived from CSB patient's fibroblasts exhibited elevated cell death rate and higher reactive oxygen species (ROS) production. Moreover, these cellular phenotypes were accompanied by an up-regulation of TXNIP and TP53 transcriptional expression. Our findings suggest that CSB modulates cell viability in pluripotent stem cells, regulating the expression of TP53 and TXNIP and ROS production.
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Magwood AC, Mundia MM, Baker MD. High levels of wild-type BRCA2 suppress homologous recombination. J Mol Biol 2012; 421:38-53. [PMID: 22579622 DOI: 10.1016/j.jmb.2012.05.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 04/23/2012] [Accepted: 05/03/2012] [Indexed: 11/26/2022]
Abstract
Endogenous levels of the BRCA2 (breast cancer susceptibility 2) protein promote homologous recombination by regulating the essential strand exchange protein RAD51. To examine BRCA2 function in homologous recombination, we expressed human BRCA2 in control mouse hybridoma cells, as well as those that were depleted of endogenous Brca2 by small interfering RNA. With moderate human BRCA2 expression, homologous recombination was stimulated. Conversely, a higher level of BRCA2 reduced homologous recombination and DNA-damage-induced Rad51 foci formation. Cells expressing high levels of BRCA2 feature normal growth, increased sensitivity to mitomycin C, and increased illegitimate recombination. BRCA2-overexpressing cells are also characterized by suppression of p53 transcriptional regulation and a corresponding reduction in the expression of the p53-responsive genes Noxa and p21. Notably, in cells expressing high levels of BRCA2, small interfering RNA depletion of human BRCA2 or ectopic expression of Rad51 increases homologous recombination and decreases illegitimate recombination. Thus, high levels of wild-type BRCA2 perturb Rad51-mediated homologous recombination, and relatively normal recombination responses can be restored by rebalancing recombination factors.
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Affiliation(s)
- Alissa C Magwood
- Department of Molecular and Cellular Biology, College of Biological Science, University of Guelph, Guelph, Ontario, Canada N1G 2W1
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Kotnis A, Namkung J, Kannan S, Jayakrupakar N, Park T, Sarin R, Mulherkar R. Multiple pathway-based genetic variations associated with tobacco related multiple primary neoplasms. PLoS One 2012; 7:e30013. [PMID: 22253860 PMCID: PMC3256192 DOI: 10.1371/journal.pone.0030013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2011] [Accepted: 12/11/2011] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND In order to elucidate a combination of genetic alterations that drive tobacco carcinogenesis we have explored a unique model system and analytical method for an unbiased qualitative and quantitative assessment of gene-gene and gene-environment interactions. The objective of this case control study was to assess genetic predisposition in a biologically enriched clinical model system of tobacco related cancers (TRC), occurring as Multiple Primary Neoplasms (MPN). METHODS Genotyping of 21 candidate Single Nucleotide Polymorphisms (SNP) from major metabolic pathways was performed in a cohort of 151 MPN cases and 210 cancer-free controls. Statistical analysis using logistic regression and Multifactor Dimensionality Reduction (MDR) analysis was performed for studying higher order interactions among various SNPs and tobacco habit. RESULTS Increased risk association was observed for patients with at least one TRC in the upper aero digestive tract (UADT) for variations in SULT1A1 Arg²¹³His, mEH Tyr¹¹³His, hOGG1 Ser³²⁶Cys, XRCC1 Arg²⁸⁰His and BRCA2 Asn³⁷²His. Gene-environment interactions were assessed using MDR analysis. The overall best model by MDR was tobacco habit/p53(Arg/Arg)/XRCC1(Arg³⁹⁹His)/mEH(Tyr¹¹³His) that had highest Cross Validation Consistency (8.3) and test accuracy (0.69). This model also showed significant association using logistic regression analysis. CONCLUSION This is the first Indian study on a multipathway based approach to study genetic susceptibility to cancer in tobacco associated MPN. This approach could assist in planning additional studies for comprehensive understanding of tobacco carcinogenesis.
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Affiliation(s)
- Ashwin Kotnis
- Advanced Centre for Treatment, Research and Education in Cancer, Navi Mumbai, India
| | - Junghyun Namkung
- Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Sadhana Kannan
- Advanced Centre for Treatment, Research and Education in Cancer, Navi Mumbai, India
| | - Nallala Jayakrupakar
- Advanced Centre for Treatment, Research and Education in Cancer, Navi Mumbai, India
| | - Taesung Park
- Department of Statistics, College of Natural Science, Seoul National University, Seoul, Korea
| | - Rajiv Sarin
- Advanced Centre for Treatment, Research and Education in Cancer, Navi Mumbai, India
| | - Rita Mulherkar
- Advanced Centre for Treatment, Research and Education in Cancer, Navi Mumbai, India
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Seeliger K, Dukowic-Schulze S, Wurz-Wildersinn R, Pacher M, Puchta H. BRCA2 is a mediator of RAD51- and DMC1-facilitated homologous recombination in Arabidopsis thaliana. THE NEW PHYTOLOGIST 2012; 193:364-75. [PMID: 22077663 DOI: 10.1111/j.1469-8137.2011.03947.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
• Mutations in the breast cancer susceptibility gene 2 (BRCA2) are correlated with hereditary breast cancer in humans. Studies have revealed that mammalian BRCA2 plays crucial roles in DNA repair. Therefore, we wished to define the role of the BRCA2 homologs in Arabidopsis in detail. • As Arabidopsis contains two functional BRCA2 homologs, an Atbrca2 double mutant was generated and analyzed with respect to hypersensitivity to genotoxic agents and recombination frequencies. Cytological studies addressing male and female meiosis were also conducted, and immunolocalization was performed in male meiotic prophase I. • The Atbrca2 double mutant showed hypersensitivity to the cross-linking agent mitomycin C and displayed a dramatic reduction in somatic homologous recombination frequency, especially after double-strand break induction. The loss of AtBRCA2 also led to severe defects in male meiosis and development of the female gametophyte and impeded proper localization of the synaptonemal complex protein AtZYP1 and the recombinases AtRAD51 and AtDMC1. • The results demonstrate that AtBRCA2 is important for both somatic and meiotic homologous recombination. We further show that AtBRCA2 is required for proper meiotic synapsis and mediates the recruitment of AtRAD51 and AtDMC1. Our results suggest that BRCA2 controls single-strand invasion steps during homologous recombination in plants.
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Affiliation(s)
- Katharina Seeliger
- Botanical Institute II, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
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Boichuk S, Hu L, Makielski K, Pandolfi PP, Gjoerup OV. Functional connection between Rad51 and PML in homology-directed repair. PLoS One 2011; 6:e25814. [PMID: 21998700 PMCID: PMC3187806 DOI: 10.1371/journal.pone.0025814] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Accepted: 09/11/2011] [Indexed: 12/30/2022] Open
Abstract
The promyelocytic leukemia protein (PML) is a tumor suppressor critical for formation of nuclear bodies (NBs) performing important functions in transcription, apoptosis, DNA repair and antiviral responses. Earlier studies demonstrated that simian virus 40 (SV40) initiates replication near PML NBs. Here we show that PML knockdown inhibits viral replication in vivo, thus indicating a positive role of PML early in infection. SV40 large T antigen (LT) induces DNA damage and, consequently, nuclear foci of the key homologous recombination repair protein Rad51 that colocalize with PML. PML depletion abrogates LT-induced Rad51 foci. LT may target PML NBs to gain access to DNA repair factors like Rad51 that are required for viral replication. We have used the SV40 model to gain insight to DNA repair events involving PML. Strikingly, even in normal cells devoid of viral oncoproteins, PML is found to be instrumental for foci of Rad51, Mre11 and BRCA1, as well as homology-directed repair after double-strand break (DSB) induction. Following LT expression or external DNA damage, PML associates with Rad51. PML depletion also causes a loss of RPA foci following γ-irradiation, suggesting that PML is required for processing of DSBs. Immunofluorescent detection of incorporated BrdU without prior denaturation indicates a failure to generate ssDNA foci in PML knockdown cells upon γ-irradiation. Consistent with the lack of RPA and BrdU foci, γ-irradiation fails to induce Chk1 activation, when PML is depleted. Taken together, we have discovered a novel functional connection between PML and the homologous recombination-mediated repair machinery, which might contribute to PML tumor suppressor activity.
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Affiliation(s)
- Sergei Boichuk
- Cancer Virology Program, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania, United States of America
| | - Liang Hu
- Cancer Virology Program, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania, United States of America
| | - Kathleen Makielski
- Cancer Virology Program, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania, United States of America
| | - Pier Paolo Pandolfi
- Department of Medicine, Beth Israel Deaconess Cancer Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Ole V. Gjoerup
- Cancer Virology Program, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
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Trapp O, Seeliger K, Puchta H. Homologs of breast cancer genes in plants. FRONTIERS IN PLANT SCIENCE 2011; 2:19. [PMID: 22629260 PMCID: PMC3355568 DOI: 10.3389/fpls.2011.00019] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Accepted: 06/02/2011] [Indexed: 05/22/2023]
Abstract
Since the initial discovery of genes involved in hereditary breast cancer in humans, a vast wealth of information has been published. Breast cancer proteins were shown to work as tumor suppressors primarily through their involvement in DNA-damage repair. Surprisingly, homologs of these genes can be found in plant genomes, as well. Here, we want to give an overview of the identification and characterization of the biological roles of these proteins, in plants. In addition to the conservation of their function in DNA repair, new plant-specific characteristics have been revealed. BRCA1 is required for the efficient repair of double strand breaks (DSB) by homologous recombination in somatic cells of the model plant Arabidopsis thaliana. Bioinformatic analysis indicates that, whereas most homologs of key components of the different mammalian BRCA1 complexes are present in plant genomes, homologs of most factors involved in the recruitment of BRCA1 to the DSB cannot be identified. Thus, it is not clear at the moment whether differences exist between plants and animals at this important step. The most conserved region of BRCA1 and BARD1 homologs in plants is a PHD domain which is absent in mammals and which, in AtBARD1, might be involved in the transcriptional regulation of plant development. The presence of a plant-specific domain prompted us to reevaluate the current model for the evolution of BRCA1 homologs and to suggest a new hypothesis, in which we postulate that plant BRCA1 and BARD1 have one common predecessor that gained a PHD domain before duplication. Furthermore, work in Arabidopsis demonstrates that - as in animals - BRCA2 homologs are important for meiotic DNA recombination. Surprisingly, recent research has revealed that AtBRCA2 also has an important role in systemic acquired resistance. In Arabidopsis, BRCA2 is involved in the transcriptional regulation of pathogenesis-related (PR) genes via its interaction with the strand exchange protein RAD51.
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Affiliation(s)
- Oliver Trapp
- Botanical Institute II, Karlsruhe Institute of TechnologyKarlsruhe, Germany
| | - Katharina Seeliger
- Botanical Institute II, Karlsruhe Institute of TechnologyKarlsruhe, Germany
| | - Holger Puchta
- Botanical Institute II, Karlsruhe Institute of TechnologyKarlsruhe, Germany
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Kim KY, Park DW, Jeung EB, Choi KC. Conditional knockout of brca1/2 and p53 in mouse ovarian surface epithelium: do they play a role in ovarian carcinogenesis? J Vet Sci 2011; 11:291-7. [PMID: 21113097 PMCID: PMC2998739 DOI: 10.4142/jvs.2010.11.4.291] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Alterations of genes are known to be critical for the induction of tumorigenesis, but the mechanism of ovarian carcinogenesis is little understood and remains to be elucidated. In this study, we investigated the roles of brca1, brca2 and p53 genes in the development of ovarian cancer using conditional knockout mice generated by a Cre-loxP recombinant system. Following the application of recombinant adenovirus expressing Cre in vitro, the proliferation of ovarian surface epithelium (OSE) was increased. For instance, a significant increase in cell growth was observed in OSE cells in vitro by conditional knockout isolated from the mice bearing concurrent floxed copies of brca1 and brca2/p53. However, the proliferative effect of the ovarian cells was not observed in concurrent brca1/brca2 or p53 knockout mice in vivo, indicating that we could not observe the direct evidence of the involvement of brca1, brca2, and p53 in ovarian carcinogenesis. Since morphological changes including tumor formation were not observed in mice bearing floxed copies of concurrent brca1/brca2 or p53, the inactivation of brca1/2 or p53 is not sufficient for the induction of tumor formation. Taken together, these results suggest that the deficiency of these genes may not be involved directly in the mechanism of ovarian carcinogenesis.
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Affiliation(s)
- Ki-Yon Kim
- Department of Obstetrics and Gynecology, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
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EMSY overexpression disrupts the BRCA2/RAD51 pathway in the DNA-damage response: implications for chromosomal instability/recombination syndromes as checkpoint diseases. Mol Genet Genomics 2011; 285:325-40. [PMID: 21409565 PMCID: PMC3064890 DOI: 10.1007/s00438-011-0612-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Accepted: 02/27/2011] [Indexed: 11/05/2022]
Abstract
EMSY links the BRCA2 pathway to sporadic breast/ovarian cancer. It encodes a nuclear protein that binds to the BRCA2 N-terminal domain implicated in chromatin/transcription regulation, but when sporadically amplified/overexpressed, increased EMSY level represses BRCA2 transactivation potential and induces chromosomal instability, mimicking the activity of BRCA2 mutations in the development of hereditary breast/ovarian cancer. In addition to chromatin/transcription regulation, EMSY may also play a role in the DNA-damage response, suggested by its ability to localize at chromatin sites of DNA damage/repair. This implies that EMSY overexpression may also repress BRCA2 in DNA-damage replication/checkpoint and recombination/repair, coordinated processes that also require its interacting proteins: PALB2, the partner and localizer of BRCA2; RPA, replication/checkpoint protein A; and RAD51, the inseparable recombination/repair enzyme. Here, using a well-characterized recombination/repair assay system, we demonstrate that a slight increase in EMSY level can indeed repress these two processes independently of transcriptional interference/repression. Since EMSY, RPA and PALB2 all bind to the same BRCA2 region, these findings further support a scenario wherein: (a) EMSY amplification may mimic BRCA2 deficiency, at least by overriding RPA and PALB2, crippling the BRCA2/RAD51 complex at DNA-damage and replication/transcription sites; and (b) BRCA2/RAD51 may coordinate these processes by employing at least EMSY, PALB2 and RPA. We extensively discuss the molecular details of how this can happen to ascertain its implications for a novel recombination mechanism apparently conceived as checkpoint rather than a DNA repair system for cell division, survival, death, and human diseases, including the tissue specificity of cancer predisposition, which may renew our thinking about targeted therapy and prevention.
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Rivera P, von Euler H. Molecular Biological Aspects on Canine and Human Mammary Tumors. Vet Pathol 2010; 48:132-46. [DOI: 10.1177/0300985810387939] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- P. Rivera
- Center of Clinical Comparative Oncology C3O, Department of Clinical Sciences, Division of Small Animals, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - H. von Euler
- Center of Clinical Comparative Oncology C3O, Department of Clinical Sciences, Division of Small Animals, Swedish University of Agricultural Sciences, Uppsala, Sweden
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Jensen RB, Carreira A, Kowalczykowski SC. Purified human BRCA2 stimulates RAD51-mediated recombination. Nature 2010; 467:678-83. [PMID: 20729832 PMCID: PMC2952063 DOI: 10.1038/nature09399] [Citation(s) in RCA: 509] [Impact Index Per Article: 36.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Accepted: 08/11/2010] [Indexed: 12/18/2022]
Abstract
Mutation of the breast cancer susceptibility gene, BRCA2, leads to breast and ovarian cancers. Mechanistic insight into the functions of human BRCA2 has been limited by the difficulty of isolating this large protein (3,418 amino acids). Here we report purification of full length BRCA2 and show that it both binds RAD51 and potentiates recombinational DNA repair by promoting assembly of RAD51 onto single-stranded DNA (ssDNA). BRCA2 acts by: targeting RAD51 to ssDNA over double-stranded DNA; enabling RAD51 to displace Replication protein-A (RPA) from ssDNA; and stabilizing RAD51-ssDNA filaments by blocking ATP hydrolysis. BRCA2 does not anneal ssDNA complexed with RPA, implying it does not directly function in repair processes that involve ssDNA annealing. Our findings show that BRCA2 is a key mediator of homologous recombination, and they provide a molecular basis for understanding how this DNA repair process is disrupted by BRCA2 mutations, which lead to chromosomal instability and cancer.
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Affiliation(s)
- Ryan B Jensen
- Department of Microbiology, University of California, Davis, California 95616, USA
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Wilson BT, Douglas SF, Polvikoski T. Astrocytoma in a Breast Cancer Lineage: Part of the BRCA2 Phenotype? J Clin Oncol 2010; 28:e596-8. [DOI: 10.1200/jco.2010.28.9173] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Affiliation(s)
- Brian T. Wilson
- Northern Genetics Service, Institute of Human Genetics, International Centre for Life, Newcastle upon Tyne, United Kingdom
| | - S. Fiona Douglas
- Northern Genetics Service, Institute of Human Genetics, International Centre for Life, Newcastle upon Tyne, United Kingdom
| | - Tuomo Polvikoski
- Institute for Ageing and Health, Newcastle University, Campus of Ageing and Vitality, Newcastle upon Tyne, United Kingdom
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Fernandez-Fernandez MR, Sot B. The relevance of protein-protein interactions for p53 function: the CPE contribution. Protein Eng Des Sel 2010; 24:41-51. [PMID: 20952436 DOI: 10.1093/protein/gzq074] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The relevance of p53 as a tumour suppressor is evident from the fact that more than 50% of the human cancers hold mutations in the gene coding for p53, and of the remaining cancers a considerable number have alterations in the p53 pathway. From its discovery 30 years ago, the importance of p53 as an essential transcription factor for tumour suppression has become clear. More recently, new and seemingly diverse roles of p53 have been discovered. It soon became clear that protein-protein interactions play an important role in the regulation of the p53 function at different levels. Here we review the contribution by Prof. Fersht and his group towards understanding the basis and functional relevance of p53 protein-protein interactions, and the important role that protein science, biophysics and structural biology have played in the science produced in the Centre for Protein Engineering over the years.
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