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Krishna Rao V, Paul S, Gulkis M, Shen Z, Nair H, Singh A, Li C, Sharma AK, Çağlayan M, Das C, Das B, Kundu CN, Narayan S, Guchhait SK. Molecular editing of NSC-666719 enabling discovery of benzodithiazinedioxide-guanidines as anticancer agents. RSC Med Chem 2024; 15:937-962. [PMID: 38516586 PMCID: PMC10953490 DOI: 10.1039/d3md00648d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 01/25/2024] [Indexed: 03/23/2024] Open
Abstract
DNA polymerase β (Polβ) is crucial for the base excision repair (BER) pathway of DNA damage repair and is an attractive target for suppressing tumorigenesis as well as chemotherapeutic intervention of cancer. In this study, a unique strategy of scaffold-hopping-based molecular editing of a bioactive agent NSC-666719 was investigated, which led to the development of new molecular motifs with Polβ inhibitory activity. NSC compound and its analogs (two series) were prepared, focusing on pharmacophore-based molecular diversity. Most compounds showed higher activities than the parent NSC-666719 and exhibited effects on apoptosis. The inhibitory activity of Polβ was evaluated in both in vitro reconstituted and in vivo intact cell systems. Compound 10e demonstrated significant Polβ interaction and inhibition characteristics, including direct, non-covalent, reversible, and comparable binding affinity. The investigated approach is useful, and the discovered novel analogs have a high potential for developing as anticancer therapeutics.
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Affiliation(s)
- Vajja Krishna Rao
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER) Sector 67, SAS Nagar Mohali Punjab 160062 India
| | - Subarno Paul
- Cancer Biology Division, School of Biotechnology, Kalinga Institute of Industrial Technology (KIIT), Deemed to be University Campus-11, Patia Bhubaneswar-751024 Odisha India
| | - Mitchell Gulkis
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida 1200 Newell Drive Gainesville FL 32610 USA
| | - Zhihang Shen
- Department of Medicinal Chemistry, College of Pharmacy, University of Florida 1345 Center Drive Gainesville FL 32610 USA
| | - Haritha Nair
- Department of Anatomy and Cell Biology, College of Medicine, University of Florida 1200 Newell Drive Gainesville FL 32610 USA
| | - Amandeep Singh
- Department of Pharmacology, Penn State Cancer Institute, CH72, Penn State College of Medicine 500 University Drive Hershey PA 17033 USA
| | - Chenglong Li
- Department of Medicinal Chemistry, College of Pharmacy, University of Florida 1345 Center Drive Gainesville FL 32610 USA
| | - Arun K Sharma
- Department of Pharmacology, Penn State Cancer Institute, CH72, Penn State College of Medicine 500 University Drive Hershey PA 17033 USA
| | - Melike Çağlayan
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida 1200 Newell Drive Gainesville FL 32610 USA
| | - Chinmay Das
- Cancer Biology Division, School of Biotechnology, Kalinga Institute of Industrial Technology (KIIT), Deemed to be University Campus-11, Patia Bhubaneswar-751024 Odisha India
| | - Biswajit Das
- Cancer Biology Division, School of Biotechnology, Kalinga Institute of Industrial Technology (KIIT), Deemed to be University Campus-11, Patia Bhubaneswar-751024 Odisha India
| | - Chanakya N Kundu
- Cancer Biology Division, School of Biotechnology, Kalinga Institute of Industrial Technology (KIIT), Deemed to be University Campus-11, Patia Bhubaneswar-751024 Odisha India
| | - Satya Narayan
- Department of Anatomy and Cell Biology, College of Medicine, University of Florida 1200 Newell Drive Gainesville FL 32610 USA
| | - Sankar K Guchhait
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER) Sector 67, SAS Nagar Mohali Punjab 160062 India
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2
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Rahim T, Levinson MA, Carufe KEW, Burak M, Meas R, Maher S, Bothwell ALM, Gades N, Sweasy JB. The hematopoietic compartment is sufficient for lupus development resulting from the POLB-Y265C mutation. PLoS One 2022; 17:e0267913. [PMID: 35486639 PMCID: PMC9053796 DOI: 10.1371/journal.pone.0267913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 04/18/2022] [Indexed: 01/28/2023] Open
Abstract
Systemic lupus erythematosus is a chronic disease characterized by autoantibodies, renal and cutaneous disease, and immune complex formation. Emerging evidence suggests that aberrant DNA repair is an underlying mechanism of lupus development. We previously showed that the POLBY265C/C mutation, which results in development of an aberrant immune repertoire, leads to lupus-like disease in mice. To address whether the hematopoietic compartment is sufficient for lupus development, we transplanted bone marrow cells from POLBY265C/C and POLB+/+ into wild-type congenic mice. Only mice transplanted with the POLBY265C/C bone marrow develop high levels of antinuclear antibodies and renal disease. In conclusion, we show that the hematopoietic compartment harvested from the POLBY265C/C mice is sufficient for development of autoimmune disease.
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Affiliation(s)
- Tania Rahim
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT, United States of America
| | - Madison A. Levinson
- Department of Cellular and Molecular Medicine and University of Arizona Cancer Center, Tucson, AZ, United States of America
| | - Kelly E. W. Carufe
- Department of Genetics, Yale University School of Medicine, New Haven, CT, United States of America
| | - Matthew Burak
- Moderna Therapeutics, Cambridge, MA, United States of America
| | - Rithy Meas
- Department of Cellular and Molecular Medicine and University of Arizona Cancer Center, Tucson, AZ, United States of America
| | - Stephen Maher
- Department of Immunology, Yale University School of Medicine, New Haven, CT, United States of America
| | - Alfred L. M. Bothwell
- Department of Immunology, Yale University School of Medicine, New Haven, CT, United States of America
| | - Naomi Gades
- Department of Comparative Medicine, Mayo Clinic Arizona, Scottsdale, AZ, United States of America
| | - Joann B. Sweasy
- Department of Cellular and Molecular Medicine and University of Arizona Cancer Center, Tucson, AZ, United States of America
- * E-mail:
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3
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Fang Q, Andrews J, Sharma N, Wilk A, Clark J, Slyskova J, Koczor CA, Lans H, Prakash A, Sobol RW. Stability and sub-cellular localization of DNA polymerase β is regulated by interactions with NQO1 and XRCC1 in response to oxidative stress. Nucleic Acids Res 2020; 47:6269-6286. [PMID: 31287140 PMCID: PMC6614843 DOI: 10.1093/nar/gkz293] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 03/24/2019] [Accepted: 04/11/2019] [Indexed: 12/14/2022] Open
Abstract
Protein–protein interactions regulate many essential enzymatic processes in the cell. Somatic mutations outside of an enzyme active site can therefore impact cellular function by disruption of critical protein–protein interactions. In our investigation of the cellular impact of the T304I cancer mutation of DNA Polymerase β (Polβ), we find that mutation of this surface threonine residue impacts critical Polβ protein–protein interactions. We show that proteasome-mediated degradation of Polβ is regulated by both ubiquitin-dependent and ubiquitin-independent processes via unique protein–protein interactions. The ubiquitin-independent proteasome pathway regulates the stability of Polβ in the cytosol via interaction between Polβ and NAD(P)H quinone dehydrogenase 1 (NQO1) in an NADH-dependent manner. Conversely, the interaction of Polβ with the scaffold protein X-ray repair cross complementing 1 (XRCC1) plays a role in the localization of Polβ to the nuclear compartment and regulates the stability of Polβ via a ubiquitin-dependent pathway. Further, we find that oxidative stress promotes the dissociation of the Polβ/NQO1 complex, enhancing the interaction of Polβ with XRCC1. Our results reveal that somatic mutations such as T304I in Polβ impact critical protein–protein interactions, altering the stability and sub-cellular localization of Polβ and providing mechanistic insight into how key protein–protein interactions regulate cellular responses to stress.
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Affiliation(s)
- Qingming Fang
- University of South Alabama Mitchell Cancer Institute, 1660 Springhill Avenue, Mobile, AL 36604, USA
| | - Joel Andrews
- University of South Alabama Mitchell Cancer Institute, 1660 Springhill Avenue, Mobile, AL 36604, USA
| | - Nidhi Sharma
- University of South Alabama Mitchell Cancer Institute, 1660 Springhill Avenue, Mobile, AL 36604, USA
| | - Anna Wilk
- University of South Alabama Mitchell Cancer Institute, 1660 Springhill Avenue, Mobile, AL 36604, USA
| | - Jennifer Clark
- University of South Alabama Mitchell Cancer Institute, 1660 Springhill Avenue, Mobile, AL 36604, USA
| | - Jana Slyskova
- Department of Molecular Genetics, Erasmus MC, Erasmus University Medical Center Rotterdam, 3000 CA Rotterdam, The Netherlands
| | - Christopher A Koczor
- University of South Alabama Mitchell Cancer Institute, 1660 Springhill Avenue, Mobile, AL 36604, USA
| | - Hannes Lans
- Department of Molecular Genetics, Erasmus MC, Erasmus University Medical Center Rotterdam, 3000 CA Rotterdam, The Netherlands.,Oncode Institute, Erasmus MC, Erasmus University Medical Center Rotterdam, 3000 CA Rotterdam, The Netherlands
| | - Aishwarya Prakash
- University of South Alabama Mitchell Cancer Institute, 1660 Springhill Avenue, Mobile, AL 36604, USA
| | - Robert W Sobol
- University of South Alabama Mitchell Cancer Institute, 1660 Springhill Avenue, Mobile, AL 36604, USA
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Mutation in DNA Polymerase Beta Causes Spontaneous Chromosomal Instability and Inflammation-Associated Carcinogenesis in Mice. Cancers (Basel) 2019; 11:cancers11081160. [PMID: 31412651 PMCID: PMC6721533 DOI: 10.3390/cancers11081160] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 08/01/2019] [Accepted: 08/08/2019] [Indexed: 12/15/2022] Open
Abstract
DNA polymerase beta (Pol β) is a key enzyme in the base excision repair (BER) pathway. Pol β is mutated in approximately 40% of human tumors in small-scale studies. The 5´-deoxyribose-5-phosphate (dRP) lyase domain of Pol β is responsible for DNA end tailoring to remove the 5’ phosphate group. We previously reported that the dRP lyase activity of Pol β is critical to maintain DNA replication fork stability and prevent cellular transformation. In this study, we tested the hypothesis that the human gastric cancer associated variant of Pol β (L22P) has the ability to promote spontaneous chromosomal instability and carcinogenesis in mice. We constructed a Pol β L22P conditional knock-in mouse model and found that L22P enhances hyperproliferation and DNA double strand breaks (DSBs) in stomach cells. Moreover, mouse embryonic fibroblasts (MEFs) derived from L22P mice frequently induce abnormal numbers of chromosomes and centrosome amplification, leading to chromosome segregation errors. Importantly, L22P mice exhibit chronic inflammation accompanied by stomach tumors. These data demonstrate that the human cancer-associated variant of Pol β can contribute to chromosomal instability and cancer development.
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Liptak C, Mahmoud MM, Eckenroth BE, Moreno MV, East K, Alnajjar KS, Huang J, Towle-Weicksel JB, Doublié S, Loria J, Sweasy JB. I260Q DNA polymerase β highlights precatalytic conformational rearrangements critical for fidelity. Nucleic Acids Res 2019; 46:10740-10756. [PMID: 30239932 PMCID: PMC6237750 DOI: 10.1093/nar/gky825] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 09/05/2018] [Indexed: 11/14/2022] Open
Abstract
DNA polymerase β (pol β) fills single nucleotide gaps in DNA during base excision repair and non-homologous end-joining. Pol β must select the correct nucleotide from among a pool of four nucleotides with similar structures and properties in order to maintain genomic stability during DNA repair. Here, we use a combination of X-ray crystallography, fluorescence resonance energy transfer and nuclear magnetic resonance to show that pol β‘s ability to access the appropriate conformations both before and upon binding to nucleotide substrates is integral to its fidelity. Importantly, we also demonstrate that the inability of the I260Q mutator variant of pol β to properly navigate this conformational landscape results in error-prone DNA synthesis. Our work reveals that precatalytic conformational rearrangements themselves are an important underlying mechanism of substrate selection by DNA pol β.
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Affiliation(s)
- Cary Liptak
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
| | - Mariam M Mahmoud
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Brian E Eckenroth
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT 05405, USA
| | - Marcus V Moreno
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT 05405, USA
| | - Kyle East
- Department of Chemistry, Yale University, New Haven, CT 06520, USA
| | - Khadijeh S Alnajjar
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Ji Huang
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Jamie B Towle-Weicksel
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Sylvie Doublié
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT 05405, USA
| | - J Patrick Loria
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
- Department of Chemistry, Yale University, New Haven, CT 06520, USA
- To whom correspondence should be addressed. Tel: +203 436 2518; Fax: +203 436 6144; . Correspondence may also be addressed to Joann B. Sweasy. Tel: +203 737 2626; Fax: +203 785 6309;
| | - Joann B Sweasy
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT 06520, USA
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA
- To whom correspondence should be addressed. Tel: +203 436 2518; Fax: +203 436 6144; . Correspondence may also be addressed to Joann B. Sweasy. Tel: +203 737 2626; Fax: +203 785 6309;
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6
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Berdis AJ. Inhibiting DNA Polymerases as a Therapeutic Intervention against Cancer. Front Mol Biosci 2017; 4:78. [PMID: 29201867 PMCID: PMC5696574 DOI: 10.3389/fmolb.2017.00078] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 11/08/2017] [Indexed: 12/11/2022] Open
Abstract
Inhibiting DNA synthesis is an important therapeutic strategy that is widely used to treat a number of hyperproliferative diseases including viral infections, autoimmune disorders, and cancer. This chapter describes two major categories of therapeutic agents used to inhibit DNA synthesis. The first category includes purine and pyrmidine nucleoside analogs that directly inhibit DNA polymerase activity. The second category includes DNA damaging agents including cisplatin and chlorambucil that modify the composition and structure of the nucleic acid substrate to indirectly inhibit DNA synthesis. Special emphasis is placed on describing the molecular mechanisms of these inhibitory effects against chromosomal and mitochondrial DNA polymerases. Discussions are also provided on the mechanisms associated with resistance to these therapeutic agents. A primary focus is toward understanding the roles of specialized DNA polymerases that by-pass DNA lesions produced by DNA damaging agents. Finally, a section is provided that describes emerging areas in developing new therapeutic strategies targeting specialized DNA polymerases.
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Affiliation(s)
- Anthony J Berdis
- Department of Chemistry, Cleveland State University, Cleveland, OH, United States.,Center for Gene Regulation in Health and Disease, Cleveland State University, Cleveland, OH, United States.,Case Comprehensive Cancer Center, Cleveland, OH, United States
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7
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Choudhary P, Kashyap PL, Goswami SK, Chakdar H, Srivastava AK, Saxena AK. Genome-Wide Analysis of Microsatellites in Alternaria arborescens and Elucidation of the Function of Polyketide Synthase (PksJ). Interdiscip Sci 2017; 10:813-822. [PMID: 28975513 DOI: 10.1007/s12539-017-0251-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 05/01/2017] [Accepted: 07/05/2017] [Indexed: 10/18/2022]
Abstract
Microsatellites or simple sequence repeats (SSRs) have been the most widely applied class of molecular markers used in genetic studies, having applications in genetic conservation, population studies, as well as diagnostics of fungi. Mining and analysis of SSRs of the whole genome sequence have been carried out in this study for the fungus Alternaria arborescens causing early blight of tomato and well known for producing mycotoxins like alternariol (AOH), alternariol monomethyl ether (AME), etc. A total of 4097 microsatellites were identified in A. Arborescens genome. Contig 1 was identified as the most SSR-rich region which was further analyzed to correlate the presence of SSRs with different biological processes. A total of 246 putative genes were predicted in this study and KEGG pathway analysis of 155 predicted genes indicated that SSRs can be linked with important metabolic pathways, molecular functioning, signal transduction, and cellular processes. The prediction of fungal mycotoxin inducer gene Polyketide synthase (PksJ) linked with SSR in this study may be a potential candidate participating in oncogenic signal transduction in human. Our study is the first report of PksJ gene in A. arborescens, a precursor of AOH and AME.
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Affiliation(s)
- Prassan Choudhary
- Microbial Technology Unit, ICAR-National Bureau of Agriculturally Important Microorganisms, Maunath Bhanjan, 275103, India
| | - Prem Lal Kashyap
- ICAR-Indian Institute of Wheat and Barley Research (IIWBR), Regional Station, Shimla, 171002, India
| | - Sanjay Kumar Goswami
- Microbial Technology Unit, ICAR-National Bureau of Agriculturally Important Microorganisms, Maunath Bhanjan, 275103, India
| | - Hillol Chakdar
- Microbial Technology Unit, ICAR-National Bureau of Agriculturally Important Microorganisms, Maunath Bhanjan, 275103, India.
| | - Alok Kumar Srivastava
- Microbial Technology Unit, ICAR-National Bureau of Agriculturally Important Microorganisms, Maunath Bhanjan, 275103, India
| | - Anil Kumar Saxena
- Microbial Technology Unit, ICAR-National Bureau of Agriculturally Important Microorganisms, Maunath Bhanjan, 275103, India
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Markkanen E. Not breathing is not an option: How to deal with oxidative DNA damage. DNA Repair (Amst) 2017; 59:82-105. [PMID: 28963982 DOI: 10.1016/j.dnarep.2017.09.007] [Citation(s) in RCA: 118] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 09/20/2017] [Indexed: 02/07/2023]
Abstract
Oxidative DNA damage constitutes a major threat to genetic integrity, and has thus been implicated in the pathogenesis of a wide variety of diseases, including cancer and neurodegeneration. 7,8-dihydro-8oxo-deoxyGuanine (8-oxo-G) is one of the best characterised oxidative DNA lesions, and it can give rise to point mutations due to its miscoding potential that instructs most DNA polymerases (Pols) to preferentially insert Adenine (A) opposite 8-oxo-G instead of the correct Cytosine (C). If uncorrected, A:8-oxo-G mispairs can give rise to C:G→A:T transversion mutations. Cells have evolved a variety of pathways to mitigate the mutational potential of 8-oxo-G that include i) mechanisms to avoid incorporation of oxidized nucleotides into DNA through nucleotide pool sanitisation enzymes (by MTH1, MTH2, MTH3 and NUDT5), ii) base excision repair (BER) of 8-oxo-G in DNA (involving MUTYH, OGG1, Pol λ, and other components of the BER machinery), and iii) faithful bypass of 8-oxo-G lesions during replication (using a switch between replicative Pols and Pol λ). In the following, the fate of 8-oxo-G in mammalian cells is reviewed in detail. The differential origins of 8-oxo-G in DNA and its consequences for genetic stability will be covered. This will be followed by a thorough discussion of the different mechanisms in place to cope with 8-oxo-G with an emphasis on Pol λ-mediated correct bypass of 8-oxo-G during MUTYH-initiated BER as well as replication across 8-oxo-G. Furthermore, the multitude of mechanisms in place to regulate key proteins involved in 8-oxo-G repair will be reviewed. Novel functions of 8-oxo-G as an epigenetic-like regulator and insights into the repair of 8-oxo-G within the cellular context will be touched upon. Finally, a discussion will outline the relevance of 8-oxo-G and the proteins involved in dealing with 8-oxo-G to human diseases with a special emphasis on cancer.
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Affiliation(s)
- Enni Markkanen
- Institute of Veterinary Pharmacology and Toxicology, Vetsuisse Faculty, University of Zürich, Winterthurerstr. 260, 8057 Zürich, Switzerland.
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9
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Tan X, Wu X, Ren S, Wang H, Li Z, Alshenawy W, Li W, Cui J, Luo G, Siegel RS, Fu SW, Lu Y. A Point Mutation in DNA Polymerase β (POLB) Gene Is Associated with Increased Progesterone Receptor (PR) Expression and Intraperitoneal Metastasis in Gastric Cancer. J Cancer 2016; 7:1472-80. [PMID: 27471563 PMCID: PMC4964131 DOI: 10.7150/jca.14844] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 03/15/2016] [Indexed: 12/29/2022] Open
Abstract
Increased expression of progesterone receptor (PR) has been reported in gastric cancer (GC). We have previously identified a functional T889C point mutation in DNA polymerase beta (POLB), a DNA repair gene in GC. To provide a detailed analysis of molecular changes associated with the mutation, human cDNA microarrays focusing on 18 signal transduction pathways were used to analyze differential gene expression profiles between GC tissues with T889C mutant in POLB gene and those with wild type. Among the differentially expressed genes, notably, PR was one of the significantly up-regulated genes in T889C mutant POLB tissues, which were subsequently confirmed in POLB gene transfected AGS cell line. Interestingly, patients with T889C mutation and PR positivity were associated with higher incidence of intraperitoneal metastasis (IM). In vitro studies indicate that PR expression was upregulated in AGS cell line when transfected with T889C mutant expression vector. Cotransfection of T889C mutant allele and PR gene induced cell migration in the cell line. These data demonstrated that T889C mutation-associated PR overexpression results in increased IM. Therefore, T889C mutation-associated PR overexpression may serve as a biomarker for an adverse prognosis for human GC.
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Affiliation(s)
- Xiaohui Tan
- 1. Laboratory of Molecular Oncology, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University School of Oncology, Beijing Cancer Hospital & Institute, 52# Fu-Cheng-Lu, Hai-Dian District, Beijing, 100142, China;; 6. Department of Medicine, The George Washington University School of Medicine and Health Sciences, 2300 Eye Street, N.W. Ross Hall 402C, Washington, DC 20037, USA
| | - Xiaoling Wu
- 2. Department of Gastroenterology, The Chengdu Military General Hospital, Chengdu, China;; 6. Department of Medicine, The George Washington University School of Medicine and Health Sciences, 2300 Eye Street, N.W. Ross Hall 402C, Washington, DC 20037, USA
| | - Shuyang Ren
- 1. Laboratory of Molecular Oncology, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University School of Oncology, Beijing Cancer Hospital & Institute, 52# Fu-Cheng-Lu, Hai-Dian District, Beijing, 100142, China
| | - Hongyi Wang
- 3. Department of Sugary, Peking University School of Oncology, Beijing Cancer Hospital & Institute, 52# Fu-Cheng-Lu, Hai-Dian District, Beijing, 100142, China
| | - Zhongwu Li
- 4. Department of Pathology, Peking University School of Oncology, Beijing Cancer Hospital & Institute, 52# Fu-Cheng-Lu, Hai-Dian District, Beijing, 100142, China
| | - Weaam Alshenawy
- 6. Department of Medicine, The George Washington University School of Medicine and Health Sciences, 2300 Eye Street, N.W. Ross Hall 402C, Washington, DC 20037, USA
| | - Wenmei Li
- 1. Laboratory of Molecular Oncology, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University School of Oncology, Beijing Cancer Hospital & Institute, 52# Fu-Cheng-Lu, Hai-Dian District, Beijing, 100142, China
| | - Jiantao Cui
- 1. Laboratory of Molecular Oncology, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University School of Oncology, Beijing Cancer Hospital & Institute, 52# Fu-Cheng-Lu, Hai-Dian District, Beijing, 100142, China
| | - Guangbin Luo
- 5. Department of Genetics, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Robert S Siegel
- 6. Department of Medicine, The George Washington University School of Medicine and Health Sciences, 2300 Eye Street, N.W. Ross Hall 402C, Washington, DC 20037, USA
| | - Sidney W Fu
- 6. Department of Medicine, The George Washington University School of Medicine and Health Sciences, 2300 Eye Street, N.W. Ross Hall 402C, Washington, DC 20037, USA
| | - Youyong Lu
- 1. Laboratory of Molecular Oncology, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University School of Oncology, Beijing Cancer Hospital & Institute, 52# Fu-Cheng-Lu, Hai-Dian District, Beijing, 100142, China
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10
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Zhao J, Ma J, Lu J, Jiang Y, Zhang Y, Zhang X, Zhao J, Yang H, Huang Y, Zhao M, Liu K, Dong Z. Involvement of p38MAPK-ATF2 signaling pathway in alternariol induced DNA polymerase β expression. Oncol Lett 2016; 12:675-679. [PMID: 27347199 DOI: 10.3892/ol.2016.4662] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 05/10/2016] [Indexed: 11/06/2022] Open
Abstract
Base excision repair (BER) systems are important for maintaining the integrity of genomes in mammalian cells. Aberrant DNA bases or broken single strands can be repaired by BER. Consequently, DNA lesions, which may be caused by cancer and aging, have a close association with BER procedure. DNA polymerase β (polβ) is a critical BER enzyme that can excise 5'-sugar phosphate prior to adding a nucleotide in the gap by its function as a DNA polymerase in the BER process. However, DNA polβ is an error-prone DNA polymerase, and overexpressing polβ increases the cellular spontaneous mutation rate. DNA polβ overexpression has been identified in various human tumors, which implies that DNA polβ overexpression has a close association with tumorigenesis. The present study showed that alternariol (AOH), a secondary product of a fungus that is found in grains and fruits, could cause DNA damage to NIH3T3 cells in a single cell gel electrophoresis, and that 2, 10 and 20 µM AOH induced DNA polβ overexpression in a dose-dependent manner. In the process, the level of phosphorylation of mitogen-activated protein kinase 14 (p38) mitogen-activated protein kinase (MAPK) and activating transcription factor 2 (ATF2) was increased. In addition, SB203580, a p38MAPK inhibitor, resulted in decreased DNA polβ expression. Small hairpin RNA-p38MAPK had the same effect; notably, DNA polβ expression was downregulated in p38MAPK knockdown cells. These data suggest that the p38MAPK-ATF2 signaling pathway may be involved in DNA polβ expression induced by AOH.
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Affiliation(s)
- Jimin Zhao
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China
| | - Junfen Ma
- Clinical Laboratory, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
| | - Jing Lu
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China
| | - Yanan Jiang
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China
| | - Yanyan Zhang
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China
| | - Xiaoyan Zhang
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China
| | - Jun Zhao
- Department of Medical Oncology, Changzhi People's Hospital, Changzhi, Shanxi 046000, P.R. China
| | - Hongyan Yang
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China
| | - Youtian Huang
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China
| | - Mingyao Zhao
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China
| | - Kangdong Liu
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China
| | - Ziming Dong
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China
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11
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DNA polymerases β and λ and their roles in cell. DNA Repair (Amst) 2015; 29:112-26. [DOI: 10.1016/j.dnarep.2015.02.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Revised: 01/29/2015] [Accepted: 02/02/2015] [Indexed: 10/24/2022]
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12
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Tan X, Wang H, Luo G, Ren S, Li W, Cui J, Gill HS, Fu SW, Lu Y. Clinical significance of a point mutation in DNA polymerase beta (POLB) gene in gastric cancer. Int J Biol Sci 2015; 11:144-55. [PMID: 25561897 PMCID: PMC4279090 DOI: 10.7150/ijbs.10692] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 11/19/2014] [Indexed: 01/17/2023] Open
Abstract
Gastric cancer (GC) is a major cause of global cancer mortality. Genetic variations in DNA repair genes can modulate DNA repair capability and, consequently, have been associated with risk of developing cancer. We have previously identified a T to C point mutation at nucleotide 889 (T889C) in DNA polymerase beta (POLB) gene, a key enzyme involved in base excision repair in primary GCs. The purpose of this study was to evaluate the mutation and expression of POLB in a larger cohort and to identify possible prognostic roles of the POLB alterations in GC. Primary GC specimens and their matched normal adjacent tissues were collected at the time of surgery. DNA, RNA and protein samples were isolated from GC specimens and cell lines. Mutations were detected by PCR-RFLP/DHPLC and sequencing analysis. POLB gene expression was examined by RT-PCR, tissue microarray, Western blotting and immunofluorescence assays. The function of the mutation was evaluated by chemosensitivity, MTT, Transwell matrigel invasion and host cell reactivation assays. The T889C mutation was detected in 18 (10.17%) of 177 GC patients. And the T889C mutation was associated with POLB overexpression, lymph nodes metastases and poor tumor differentiation. In addition, patients with- the mutation had significantly shorter survival time than those without-, following postoperative chemotherapy. Furthermore, cell lines with T889C mutation in POLB gene were more resistant to the treatment of 5-fluorouracil, cisplatin and epirubicin than those with wild type POLB. Forced expression of POLB gene with T889C mutation resulted in enhanced cell proliferation, invasion and resistance to anticancer drugs, along with increased DNA repair capability. These results suggest that POLB gene with T889C mutation in surgically resected primary gastric tissues may be clinically useful for predicting responsiveness to chemotherapy in patients with GC. The POLB gene alteration may serve as a prognostic biomarker for GC.
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Affiliation(s)
- Xiaohui Tan
- 1. Laboratory of Molecular Oncology, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education); ; 4. Department of Medicine, The George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA
| | - Hongyi Wang
- 2. Department of Sugary, Peking University School of Oncology, Beijing Cancer Hospital & Institute, Beijing, 100142, P.R. China
| | - Guangbin Luo
- 3. Department of Genetics, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Shuyang Ren
- 1. Laboratory of Molecular Oncology, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education)
| | - Wenmei Li
- 1. Laboratory of Molecular Oncology, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education)
| | - Jiantao Cui
- 1. Laboratory of Molecular Oncology, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education)
| | - Harindarpal S Gill
- 4. Department of Medicine, The George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA
| | - Sidney W Fu
- 4. Department of Medicine, The George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA
| | - Youyong Lu
- 1. Laboratory of Molecular Oncology, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education)
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Oxidatively induced DNA damage and its repair in cancer. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2014; 763:212-45. [PMID: 25795122 DOI: 10.1016/j.mrrev.2014.11.002] [Citation(s) in RCA: 179] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Revised: 11/03/2014] [Accepted: 11/04/2014] [Indexed: 12/28/2022]
Abstract
Oxidatively induced DNA damage is caused in living organisms by endogenous and exogenous reactive species. DNA lesions resulting from this type of damage are mutagenic and cytotoxic and, if not repaired, can cause genetic instability that may lead to disease processes including carcinogenesis. Living organisms possess DNA repair mechanisms that include a variety of pathways to repair multiple DNA lesions. Mutations and polymorphisms also occur in DNA repair genes adversely affecting DNA repair systems. Cancer tissues overexpress DNA repair proteins and thus develop greater DNA repair capacity than normal tissues. Increased DNA repair in tumors that removes DNA lesions before they become toxic is a major mechanism for development of resistance to therapy, affecting patient survival. Accumulated evidence suggests that DNA repair capacity may be a predictive biomarker for patient response to therapy. Thus, knowledge of DNA protein expressions in normal and cancerous tissues may help predict and guide development of treatments and yield the best therapeutic response. DNA repair proteins constitute targets for inhibitors to overcome the resistance of tumors to therapy. Inhibitors of DNA repair for combination therapy or as single agents for monotherapy may help selectively kill tumors, potentially leading to personalized therapy. Numerous inhibitors have been developed and are being tested in clinical trials. The efficacy of some inhibitors in therapy has been demonstrated in patients. Further development of inhibitors of DNA repair proteins is globally underway to help eradicate cancer.
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14
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DNA polymerase beta overexpression correlates with poor prognosis in esophageal cancer patients. CHINESE SCIENCE BULLETIN-CHINESE 2013. [DOI: 10.1007/s11434-013-5956-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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15
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DNA polymerase β mutations and survival of patients with esophageal squamous cell carcinoma in Linzhou City, China. Tumour Biol 2013; 35:553-9. [DOI: 10.1007/s13277-013-1077-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Accepted: 08/05/2013] [Indexed: 11/25/2022] Open
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16
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Zhao W, Wu M, Lai Y, Deng W, Liu Y, Zhang Z. Involvement of DNA polymerase β overexpression in the malignant transformation induced by benzo[a]pyrene. Toxicology 2013; 309:73-80. [PMID: 23652152 DOI: 10.1016/j.tox.2013.04.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 04/27/2013] [Accepted: 04/27/2013] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To explore the relationship between DNA polymerase β (pol β) overexpression and benzo[a]pyrene (BaP) carcinogenesis. METHODS Firstly, mouse embryonic fibroblasts that express wild-type level of DNA polymerase β (pol β cell) and high level of pol β (pol β oe cell) were treated by various concentrations of BaP to determine genetic instability induced by BaP under differential expression levels of pol β. Secondly, malignant transformation of pol β cells by low concentration of BaP (20 μM) was determined by soft agar colony formation assay and transformation focus assay. Thirdly, the mRNA and protein levels of BaP-transformed pol β cells (named pol β-T cells) was measured by reverse transcriptase-polymerase chain reaction (RT-PCR) and western blot, and the genetic instability of these cells were examined by HPRT gene mutation assay and random amplified polymorphic DNA (RAPD) assay. RESULTS Pol β cells were successfully transformed into malignant pol β-T cells by an exposure to low concentration of BaP for 6 months. Pol β-T cells exhibited increased levels of pol β gene expression, HPRT gene mutation frequency and polymorphisms of RAPD products that were comparable to those of pol β oe cells. CONCLUSION Pol β overexpression and its-associated genetic instability may play a key role in BaP carcinogenesis.
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Affiliation(s)
- Wei Zhao
- Department of Environmental Health, West China School of Public Health, Sichuan University, Chengdu, Sichuan, People's Republic of China
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17
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DNA polymerase beta promoter mutations affect gene transcription, translation and the sensitivity of esophageal cancer cells to cisplatin treatment. Mol Biol Rep 2012; 40:1333-9. [PMID: 23117284 DOI: 10.1007/s11033-012-2177-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Accepted: 10/08/2012] [Indexed: 01/30/2023]
Abstract
The ability of a promoter to initiate transcription is important for the control of gene expression. Mutations in the DNA polymerase beta (po1β) promoter may affect the transcription of this gene; however, the relationship between these mutations and the upregulation of the expression of po1β remains unclear. Therefore, in the present study, three po1β promoter mutants (M1, -37 C→A; M2, -114 G→A, -37 C→A; M3, -194 T→C) were generated to examine the effect of promoter mutations on polβ gene expression and sensitivity to cisplatin. We found that the M1 and M2 mutant polβ promoter constructs showed higher RLA than the wild-type polβ promoter (P < 0.01), whereas the activity of the M3 polβ promoter did not differ significantly from that of the wild-type polβ promoter (P > 0.05). The expression levels of polβ mRNA and protein were significantly higher (P < 0.01) and the sensitivity to cisplatin was significantly lower (P < 0.05) in Eca9706(-/-)-M1 and Eca9706(-/-)-M2 cells than in Eca9706(-/-)-W. The expression levels of polβ mRNA and protein and the sensitivity to cisplatin were not significantly different between Eca9706(-/-)-M3 and Eca9706(-/-)-W cells (P > 0.05).These results revealed that specific mutations of the polymerase beta gene promoter significantly enhanced the gene's transcriptional activity. These mutations correspondingly increased the gene's mRNA and protein product, at the same time reduced the esophageal cancer cells' sensitivity to cisplatin.
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Abstract
There are 15 different DNA polymerases encoded in mammalian genomes, which are specialized for replication, repair or the tolerance of DNA damage. New evidence is emerging for lesion-specific and tissue-specific functions of DNA polymerases. Many point mutations that occur in cancer cells arise from the error-generating activities of DNA polymerases. However, the ability of some of these enzymes to bypass DNA damage may actually defend against chromosome instability in cells, and at least one DNA polymerase, Pol ζ, is a suppressor of spontaneous tumorigenesis. Because DNA polymerases can help cancer cells tolerate DNA damage, some of these enzymes might be viable targets for therapeutic strategies.
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Affiliation(s)
| | | | - Richard D. Wood
- Correspondence to: 1808 Park Road 1C, P.O. Box 389, Smithville, TX, USA, 78957 Tel: (512) 237-9431 Fax: (512) 237-6532
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19
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Belousova EA, Lavrik OI. DNA polymerases β and λ and their roles in DNA replication and repair. Mol Biol 2010. [DOI: 10.1134/s0026893310060014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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20
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Hoffmann JS, Cazaux C. Aberrant expression of alternative DNA polymerases: a source of mutator phenotype as well as replicative stress in cancer. Semin Cancer Biol 2010; 20:312-9. [PMID: 20934518 DOI: 10.1016/j.semcancer.2010.10.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Accepted: 10/01/2010] [Indexed: 12/22/2022]
Abstract
The cell life span depends on a subtle equilibrium between the accurate duplication of the genomic DNA and less stringent DNA transactions which allow cells to tolerate mutations associated with DNA damage. The physiological role of the alternative, specialized or TLS (translesion synthesis) DNA polymerases could be to favor the necessary "flexibility" of the replication machinery, by allowing DNA replication to occur even in the presence of blocking DNA damage. As these alternative DNA polymerases are inaccurate when replicating undamaged DNA, the regulation of their expression needs to be carefully controlled. Evidence in the literature supports that dysregulation of these error-prone enzymes contributes to the acquisition of a mutator phenotype that, along with defective cell cycle control or other genome stability pathways, could be a motor for accelerated tumor progression.
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Affiliation(s)
- Jean-Sébastien Hoffmann
- CNRS, IPBS (Institute of Pharmacology and Structural Biology), 205, route de Narbonne, University of Toulouse, UPS, 31077 Toulouse, France.
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21
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Vens C, Begg AC. Targeting Base Excision Repair as a Sensitization Strategy in Radiotherapy. Semin Radiat Oncol 2010; 20:241-9. [DOI: 10.1016/j.semradonc.2010.05.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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22
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Simonelli V, D'Errico M, Palli D, Prasad R, Wilson SH, Dogliotti E. Characterization of DNA polymerase beta splicing variants in gastric cancer: the most frequent exon 2-deleted isoform is a non-coding RNA. Mutat Res 2009; 670:79-87. [PMID: 19635489 DOI: 10.1016/j.mrfmmm.2009.07.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Revised: 07/16/2009] [Accepted: 07/16/2009] [Indexed: 10/20/2022]
Abstract
DNA repair polymerase beta (Pol beta) gene variants are frequently associated with tumor tissues. In this study a search for Pol beta mutants and splice variants was conducted in matched normal and tumor gastric tissues and blood samples from healthy donors. No tumor associated mutations were found while a variety of alternative Pol beta splicing variants were detected with high frequency in all the specimens analysed. Quantitative PCR of the Pol beta variant lacking exon 2 (Ex2Delta) and the isoforms with exon 11 skipping allowed to clarify that these variants are not tumor- neither tissue-specific and their levels vary greatly among different individuals. The most frequent Ex2Delta variant was further characterized. We clearly demonstrated that this variant does not encode protein, as detected by both western blotting and immunofluorescence analysis of human AGS cells expressing HA-tagged Ex2Delta. The lack of translation was confirmed by comparing the DNA gap-filling capacity and alkylation sensitivity of wild type and Pol beta null murine fibroblasts expressing the human Ex2Delta variant. We showed that the Ex2Delta transcript is polyadenylated and its half-life is significantly longer than that of the wild type mRNA as inferred by treating AGS cells with actinomycin D. Moreover, we found that it localizes to polyribosomes suggesting a role as post-transcriptional regulator. This study identifies a new type of DNA repair variants that do not give rise to functional proteins but to non-coding RNAs that could either modulate target mRNAs or represent unproductive splicing events.
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Affiliation(s)
- Valeria Simonelli
- Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Rome, Italy
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23
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Faumont N, Le Clorennec C, Teira P, Goormachtigh G, Coll J, Canitrot Y, Cazaux C, Hoffmann JS, Brousset P, Delsol G, Feuillard J, Meggetto F. Regulation of DNA polymerase beta by the LMP1 oncoprotein of EBV through the nuclear factor-kappaB pathway. Cancer Res 2009; 69:5177-85. [PMID: 19491276 DOI: 10.1158/0008-5472.can-08-2866] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The repair DNA polymerase beta (Polbeta), when overexpressed, plays a critical role in generating genetic instability via its interference with the genomic replication program. Up-regulation of Polbeta has been reported in many tumor types that exhibit genetic aberrations, including EBV-related B-cell lymphomas. However, the mechanisms responsible for its overexpression have never been examined. Here, we report that both expression and activity of Polbeta, in EBV-immortalized B cells, are induced by several natural genetic variants of LMP1, an oncoprotein associated with the vast majority of EBV-related tumors. Conversely, we found that the expression of Polbeta decreased when LMP1 signaling was down-regulated by a dominant negative of LMP1 or an inhibitor of the nuclear factor-kappaB (NF-kappaB) pathway, the main transduction pathway activated by LMP1, strongly supporting a role of NF-kappaB in the LMP1-mediated Polbeta regulation. Using electrophoretic mobility shift assay experiments from several EBV-immortalized B-cell nuclear extracts, we identified an LMP1-dependent p50/c-Rel heterodimer on a proximal kappaB binding site (-211 to -199nt) of the Polbeta promoter. This result was correlated with a specific Polbeta kappaB transcriptional activity. Taken together, our data enlighten a new mechanism responsible for Polbeta overexpression in EBV-infected cells, mediated by LMP1 and dependent on NF-kappaB activation.
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Affiliation(s)
- Nathalie Faumont
- Institut National de la Sante et de la Recherche Medicale-U563, CPTP
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24
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Capellá G, Pera G, Sala N, Agudo A, Rico F, Del Giudicce G, Plebani M, Palli D, Boeing H, Bueno-de-Mesquita HB, Carneiro F, Berrino F, Vineis P, Tumino R, Panico S, Berglund G, Simán H, Nyrén O, Hallmans G, Martinez C, Dorronsoro M, Barricarte A, Navarro C, Quirós JR, Allen N, Key T, Bingham S, Caldas C, Linseisen J, Nagel G, Overvad K, Tjonneland A, Boshuizen HC, Peeters PHM, Numans ME, Clavel-Chapelon F, Trichopoulou A, Lund E, Jenab M, Kaaks R, Riboli E, González CA. DNA repair polymorphisms and the risk of stomach adenocarcinoma and severe chronic gastritis in the EPIC-EURGAST study. Int J Epidemiol 2008; 37:1316-25. [PMID: 18641418 DOI: 10.1093/ije/dyn145] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND The contribution of genetic variation in DNA repair genes to gastric cancer (GC) risk remains essentially unknown. The aim of this study was to explore the relative contribution of DNA repair gene polymorphisms to GC risk and severe chronic atrophic gastritis (SCAG). Method A nested case control study within the EPIC cohort was performed including 246 gastric adenocarcinomas and 1175 matched controls. Controls with SCAG (n = 91), as defined by low pepsinogen A (PGA) levels, and controls with no SCAG (n = 1061) were also compared. Twelve polymorphisms at DNA repair genes (MSH2, MLH1, XRCC1, OGG1 and ERCC2) and TP53 gene were analysed. Antibodies against Helicobacter pylori were measured. RESULTS No association was observed for any of these polymorphisms with stomach cancer risk. However, ERCC2 K751Q polymorphism was associated with an increased risk for non-cardial neoplasm [odds ratio (OR) = 1.78; 95% confidence interval (CI) 1.02-3.12], being ERCC2 K751Q and D312N polymorphisms associated with the diffuse type. ERCC2 D312N (OR = 2.0; 95% CI 1.09-3.65) and K751Q alleles (OR = 1.82; 95% CI 1.01-3.30) and XRCC1 R399Q (OR = 1.69; 95% CI 1.02-2.79) allele were associated with an increased risk for SCAG. CONCLUSION Our study supports a role of ERCC2 in non-cardial GC but not in cardial cancer. A concordant result was observed for subjects with low PGA levels. XRCC1 allele was associated also with SCAG. This is the first prospective study suggesting that individual variation in DNA repair may be relevant for gastric carcinogenesis, a finding that will require further confirmation validation in larger independent studies.
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Affiliation(s)
- Gabriel Capellá
- Translational Research Laboratory, IDIBELL-Catalan Institute of Oncology, Barcelona, Spain.
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25
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Trivedi RN, Wang XH, Jelezcova E, Goellner EM, Tang JB, Sobol RW. Human methyl purine DNA glycosylase and DNA polymerase beta expression collectively predict sensitivity to temozolomide. Mol Pharmacol 2008; 74:505-16. [PMID: 18477668 DOI: 10.1124/mol.108.045112] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Overexpression of N-methylpurine DNA glycosylase (MPG) has been suggested as a possible gene therapy approach to sensitize tumor cells to the cell-killing effects of temozolomide, an imidazotetrazine-class chemotherapeutic alkylating agent. In the present study, we show that both elevated MPG expression and short hairpin RNA-mediated loss of DNA polymerase beta (Pol beta) expression in human breast cancer cells increases cellular sensitivity to temozolomide. Resistance to temozolomide is restored by complementation of either wild-type human Pol beta or human Pol beta with an inactivating mutation specific to the polymerase active site yet functional for 5'-deoxyribose-phosphate (5'dRP) lyase activity. These genetic and cellular studies uniquely demonstrate that overexpression of MPG causes an imbalance in base excision repair (BER), leading to an accumulation of cytotoxic 5'dRP lesions, and that the 5'dRP lyase activity of Pol beta is required to restore resistance to temozolomide. These results imply that Pol beta-dependent 5'dRP lyase activity is the rate-limiting step in BER in these cells and suggests that BER is a tightly balanced pathway for the repair of alkylated bases such as N7-methylguanine and N3-methyladenine. Furthermore, we find that 5'dRP-mediated cell death is independent of caspase-3 activation and does not induce the formation of autophagosomes, as measured by green fluorescent protein-light chain 3 localization. The experiments presented herein suggest that it will be important to investigate whether an active BER pathway could be partially responsible for the temozolomide-mediated resistance seen in some tumors and that balanced BER protein expression and overall BER capacity may help predict sensitivity to temozolomide.
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Affiliation(s)
- Ram N Trivedi
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213-1863, USA
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26
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Sharma RA, Dianov GL. Targeting base excision repair to improve cancer therapies. Mol Aspects Med 2007; 28:345-74. [PMID: 17706275 DOI: 10.1016/j.mam.2007.06.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2007] [Revised: 05/30/2007] [Accepted: 06/05/2007] [Indexed: 01/05/2023]
Abstract
Most commonly used cancer therapies, particularly ionizing radiation and certain classes of cytotoxic chemotherapies, cause cell death by damaging DNA. Base excision repair (BER) is the major system responsible for the removal of corrupt DNA bases and repair of DNA single strand breaks generated spontaneously and induced by exogenous DNA damaging factors such as certain cancer therapies. In this review, the physico-chemical properties of the proteins involved in BER are discussed with particular emphasis on molecular mechanisms coordinating repair processes. The aim of this review is to apply extensive knowledge that currently exists regarding the biochemical mechanisms involved in human BER to the molecular biology of current therapies for cancer. It is anticipated that the application of this knowledge will translate into the development of novel effective therapies for improving existing treatments such as radiation therapy and oxaliplatin chemotherapy.
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Affiliation(s)
- Ricky A Sharma
- Radiation Oncology & Biology, University of Oxford, Churchill Hospital, Oxford OX3 7LJ, UK
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27
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Sweasy JB, Lauper JM, Eckert KA. DNA polymerases and human diseases. Radiat Res 2006; 166:693-714. [PMID: 17067213 DOI: 10.1667/rr0706.1] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2006] [Accepted: 07/12/2006] [Indexed: 11/03/2022]
Abstract
DNA polymerases function in DNA replication, repair, recombination and translesion synthesis. Currently, 15 DNA polymerase genes have been identified in human cells, belonging to four distinct families. In this review, we briefly describe the biochemical activities and known cellular roles of each DNA polymerase. Our major focus is on the phenotypic consequences of mutation or ablation of individual DNA polymerase genes. We discuss phenotypes of current mouse models and altered polymerase functions and the relationship of DNA polymerase gene mutations to human cell phenotypes. Interestingly, over 120 single nucleotide polymorphisms (SNPs) have been identified in human populations that are predicted to result in nonsynonymous amino acid substitutions of DNA polymerases. We discuss the putative functional consequences of these SNPs in relation to human disease.
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Affiliation(s)
- Joann B Sweasy
- Department of Therapeutic Radiology, Yale University School of Medicine, 15 York Street, HRT 313D, P.O. Box 208040, New Haven, CT 06520-8040, USA.
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28
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Abstract
In mammalian cells, base excision repair (BER) is the major repair pathway involved in the removal of non-bulky damaged nucleotides. The fidelity of BER is dependent on the polymerization step, where the major BER DNA polymerase (Pol beta) must incorporate the correct Watson-Crick base paired nucleotide into the one nucleotide repair gap. Recent studies have indicated that expression of some Pol beta variants or changes in expression of wild-type Pol beta protein, frequently found in cancer cells, can lead to DNA repair synthesis errors and confers to cells a mutator phenotype.
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Affiliation(s)
- Katie K L Chan
- Radiation and Genome Stability Unit, Medical Research Council Harwell, Oxfordshire, UK
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29
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Zhao Y, Zheng J, Ling Y, Hou L, Zhang B. Transcriptional upregulation of DNA polymerase beta by TEIF. Biochem Biophys Res Commun 2005; 333:908-16. [PMID: 15963946 DOI: 10.1016/j.bbrc.2005.05.172] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2005] [Accepted: 05/24/2005] [Indexed: 11/19/2022]
Abstract
The overexpression of DNA polymerase beta (beta-pol) has been identified in lots of human cancers, but the mechanism has seldom been investigated. Telomerase transcriptional element-interacting factor (TEIF) can bind to hTERT promoter, stimulating its transcription and telomerase activities. Here, we report that TEIF could also enhance the expression of beta-pol at transcription level. TEIF could specifically activate transcription of beta-pol promoter, but not that of DNA polymerase alpha or delta promoter. The responsible sequences for binding of TEIF were revealed as GC-rich elements dispersing from +19 to -29 nt of beta-pol promoter, which due to mutations caused decreasing in binding of TEIF and apparent losing of transactivation activity. The in vivo interaction between TEIF and beta-pol promoter was identified by chromatin immunoprecipitation assay. Besides, ectopic expression of TEIF in HeLa cells could upregulate both levels of endogenous beta-pol mRNA and protein, and consequently increases resistance to the oxidative stress of H2O2. The data may provide new clue to the elucidation of beta-pol overexpression in cancers and also a functional link between beta-pol and telomerase.
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Affiliation(s)
- Yuanjun Zhao
- Department of Pathology, Health Science Center, Peking University, Beijing 100083, China
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30
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Sweasy JB, Lang T, Starcevic D, Sun KW, Lai CC, Dimaio D, Dalal S. Expression of DNA polymerase {beta} cancer-associated variants in mouse cells results in cellular transformation. Proc Natl Acad Sci U S A 2005; 102:14350-5. [PMID: 16179390 PMCID: PMC1242307 DOI: 10.1073/pnas.0505166102] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Thirty percent of the 189 tumors studied to date express DNA polymerase beta variants. One of these variants was identified in a prostate carcinoma and is altered from isoleucine to methionine at position 260, within the hydrophobic hinge region of the protein. Another variant was identified in a colon carcinoma and is altered at position 289 from lysine to methionine, within helix N of the protein. We have shown that the types of mutations induced by these cancer-associated variants are different from those induced by the wild-type enzyme. In this study, we show that expression of the I260M and K289M cancer-associated variants in mouse C127 cells results in a transformed phenotype in the great majority of cell clones tested, as assessed by focus formation and anchorage-independent growth. Strikingly, cellular transformation occurs after a variable number of passages in culture but, once established, does not require continuous expression of the polymerase beta variant proteins, implying that it has a mutational basis. Because DNA polymerase beta functions in base excision repair, our results suggest that mutations that arise during this process can lead to the onset or progression of cancer.
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Affiliation(s)
- Joann B Sweasy
- Departments of Therapeutic Radiology and Genetics, Yale University School of Medicine, New Haven, CT 06520, USA.
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