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Valikhani M, Rahimian E, Ahmadi SE, Chegeni R, Safa M. Involvement of classic and alternative non-homologous end joining pathways in hematologic malignancies: targeting strategies for treatment. Exp Hematol Oncol 2021; 10:51. [PMID: 34732266 PMCID: PMC8564991 DOI: 10.1186/s40164-021-00242-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 10/13/2021] [Indexed: 12/31/2022] Open
Abstract
Chromosomal translocations are the main etiological factor of hematologic malignancies. These translocations are generally the consequence of aberrant DNA double-strand break (DSB) repair. DSBs arise either exogenously or endogenously in cells and are repaired by major pathways, including non-homologous end-joining (NHEJ), homologous recombination (HR), and other minor pathways such as alternative end-joining (A-EJ). Therefore, defective NHEJ, HR, or A-EJ pathways force hematopoietic cells toward tumorigenesis. As some components of these repair pathways are overactivated in various tumor entities, targeting these pathways in cancer cells can sensitize them, especially resistant clones, to radiation or chemotherapy agents. However, targeted therapy-based studies are currently underway in this area, and furtherly there are some biological pitfalls, clinical issues, and limitations related to these targeted therapies, which need to be considered. This review aimed to investigate the alteration of DNA repair elements of C-NHEJ and A-EJ in hematologic malignancies and evaluate the potential targeted therapies against these pathways.
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Affiliation(s)
- Mohsen Valikhani
- Department of Hematology and Blood Banking, Faculty of Allied Medicine, School of Allied Medical Sciences, Iran University of Medical Sciences, Tehran, Iran
| | - Elahe Rahimian
- Department of Medical Translational Oncology, National Center for Tumor Diseases (NCT) Dresden, Dresden, Germany
| | - Seyed Esmaeil Ahmadi
- Department of Hematology and Blood Banking, Faculty of Allied Medicine, School of Allied Medical Sciences, Iran University of Medical Sciences, Tehran, Iran
| | - Rouzbeh Chegeni
- Medical Laboratory Sciences, Program, College of Health and Human Sciences, Northern Illinois University, DeKalb, IL, USA
| | - Majid Safa
- Department of Hematology and Blood Banking, Faculty of Allied Medicine, School of Allied Medical Sciences, Iran University of Medical Sciences, Tehran, Iran.
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Shelke S, Das B. Radio-adaptive response and correlation of non-homologous end joining repair gene polymorphisms [XRRC5 (3R/2R/1R/0R), XRCC6(C/G) and XRCC7 (G/T)] in human peripheral blood mononuclear cells exposed to gamma radiation. Genes Environ 2021; 43:9. [PMID: 33685509 PMCID: PMC7938547 DOI: 10.1186/s41021-021-00176-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Accepted: 02/05/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Radio-adaptive response (RAR) is transient phenomena, where cells conditioned with a small dose (priming) of ionizing radiation shows significantly reduced DNA damage with a subsequent high challenging dose. The role of DNA double strand break repair gene polymorphism in RAR is not known. In the present study attempt was made to find out the influence of NHEJ repair gene polymorphisms [a VNTR; XRCC5 (3R/2R/1R/0R); two single nucleotide polymorphisms (SNPs); XRCC6 (C/G) and XRCC7 (G/T)] with DNA damage, repair and mRNA expression in human PBMCs in dose and adaptive response studies. Genomic DNA extracted from venous blood samples of 20 random healthy donors (16 adaptive and 4 non-adaptive) and genotyping of NHEJ repair genes was carried out using PCR amplified length polymorphism. RESULTS The dose response study revealed significant positive correlation of genotypes at XRRC5 (3R/2R/1R/0R), XRCC6(C/G) and XRCC7 (G/T) with DNA damage. Donors having genotypes with 2R allele at XRCC5 showed significant positive correlation with mRNA expression level (0R/2R: r = 0.846, P = 0.034; 1R/2R: r = 0.698, P = 0.0001 and 2R/2R: r = 0.831, P = 0.0001) for dose response. Genotypes C/C and C/G of XRCC6 showed a significant positive correlation (P = 0.0001), whereas, genotype T/T of XRCC7 showed significant negative correlation (r = - 0.376, P = 0.041) with mRNA expression. CONCLUSION Interestingly, adaptive donors having C/G genotype of XRCC6 showed significantly higher (P < 0.05) mRNA expression level in primed cells suggesting their role in RAR. In addition, NHEJ repair gene polymorphisms play crucial role with radio-sensitivity and RAR in human PBMCs.
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Affiliation(s)
- Shridevi Shelke
- Low Level Radiation Research Section, Radiation Biology & Health Sciences Division, Bio-Sciences Group, Bhabha Atomic Research Centre, Trombay, Mumbai, 400 085, India
| | - Birajalaxmi Das
- Low Level Radiation Research Section, Radiation Biology & Health Sciences Division, Bio-Sciences Group, Bhabha Atomic Research Centre, Trombay, Mumbai, 400 085, India.
- Homi Bhabha National Institute (HBNI), Anushaktinagar, Mumbai, 400094, India.
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Rahimian E, Amini A, Alikarami F, Pezeshki SMS, Saki N, Safa M. DNA repair pathways as guardians of the genome: Therapeutic potential and possible prognostic role in hematologic neoplasms. DNA Repair (Amst) 2020; 96:102951. [PMID: 32971475 DOI: 10.1016/j.dnarep.2020.102951] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 07/30/2020] [Accepted: 08/10/2020] [Indexed: 11/30/2022]
Abstract
DNA repair pathways, which are also identified as guardians of the genome, protect cells from frequent damage that can lead to DNA breaks. The most deleterious types of damage are double-strand breaks (DSBs), which are repaired by homologous recombination (HR) and non-homologous end joining (NHEJ). Single strand breaks (SSBs) can be corrected through base excision repair (BER), nucleotide excision repair (NER), and mismatch repair (MMR). Failure to restore DNA lesions or inappropriately repaired DNA damage culminates in genomic instability and changes in the regulation of cellular functions. Intriguingly, particular mutations and translocations are accompanied by special types of leukemia. Besides, expression patterns of certain repair genes are altered in different hematologic malignancies. Moreover, analysis of mutations in key mediators of DNA damage repair (DDR) pathways, as well as investigation of their expression and function, may provide us with emerging biomarkers of response/resistance to treatment. Therefore, defective DDR pathways can offer a rational starting point for developing DNA repair-targeted drugs. In this review, we address genetic alterations and gene/protein expression changes, as well as provide an overview of DNA repair pathways.
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Affiliation(s)
- Elahe Rahimian
- Department of Hematology and Blood Banking, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Ali Amini
- Department of Hematology and Blood Banking, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Fatemeh Alikarami
- Center for Childhood Cancer Research, Children's Hospital of Philadelphia (CHOP), Philadelphia, PA 19104, USA
| | - Seyed Mohammad Sadegh Pezeshki
- Thalassemia & Hemoglobinopathy Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Najmaldin Saki
- Thalassemia & Hemoglobinopathy Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Majid Safa
- Department of Hematology and Blood Banking, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran; Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran.
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Safarzad M, Besharat S, Salimi S, Azarhoush R, Behnampour N, Joshaghani HR. Association between selenium, cadmium, and arsenic levels and genetic polymorphisms in DNA repair genes (XRCC5, XRCC6) in gastric cancerous and non-cancerous tissue. J Trace Elem Med Biol 2019; 55:89-95. [PMID: 31345372 DOI: 10.1016/j.jtemb.2019.06.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 05/05/2019] [Accepted: 06/11/2019] [Indexed: 12/22/2022]
Abstract
Gastric cancer is one of the most prevalent cancers in northern Iran. The DNA repair genes X-ray repair cross-complementing (XRCC) group 5, XRCC6, which are important members of non-homologous end-joining repair system, play an important role in repairing the DNA double-strand breaks. Chronic exposure to heavy metals has long been recognized as being capable of augmenting gastric cancer incidence among exposed human populations. Since trace elements could directly or indirectly damage DNA, and polymorphism in DNA DSBs-repair genes can alter the capacity of system repair, we assumed that XRCC5 VNTR and XRCC6-61C >G polymorphism also impress the DSBs-repair system ability and contribute to gastric cancer. Therefore, the objective of this research was to evaluate the tissue accumulation of Selenium (Se), Cadmium (Cd) and Arsenic (As), and XRCC5 VNTR, XRCC6-61C >G polymorphisms in cancerous and non-cancerous tissues in Golestan province. The study population included 46 gastric cancer patients and 43 cancer-free controls. Two polymorphisms of XRCC5, XRCC6 were genotyped using polymerase chain reaction (PCR) or polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Further employed was atomic absorption spectroscopy so as to determine the levels of Se, Cd and As. Finally, the data were analyzed by SPSS (version 16) statistical software. The Se level was significantly higher in tumors as compared to non-tumor tissues, but there was no significant correlation between As and Cd in cancerous and noncancerous tissues. Allele frequencies of the selected genes were not statistically different between groups regarding XRCC6 (-61C>G). XRCC5 0R/0R, 0R/1R, 1R/1R, and 0R/2R genotypes were more common in cancerous group. High levels of Se in cancerous tissues vs. non-cancerous tissues may be one of the carcinogenic factors; in Golestan province, unlike other regions of Iran and the world, the level of Se is high, hence the higher risks of gastric cancer.
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Affiliation(s)
- Mahdieh Safarzad
- Metabolic disorders research center, Golestan University of Medical Sciences, Gorgan, Iran
| | - Sima Besharat
- Golestan Research Center of Gastroenterology and Hepatology, Golestan University of Medical Sciences, Gorgan, Iran.
| | - Saeedeh Salimi
- Cellular and Molecular Research Center, Zahedan University of Medical Sciences, Zahedan, Iran and Department of Clinical Biochemistry, School of Medicine, ZahedanUniversity of Medical Sciences, Zahedan, Iran
| | - Ramin Azarhoush
- Golestan Research Center of Gastroenterology and Hepatology, Golestan University of Medical Sciences, Gorgan, Iran
| | - Naser Behnampour
- Biostatistics Department, Faculty of Health, Golestan University of Medical Sciences, Gorgan, Iran
| | - Hamid Reza Joshaghani
- Laboratory sciences research center, Golestan University of Medical Sciences, Gorgan, Iran; Golestan Research Center of Gastroenterology and Hepatology, Golestan University of Medical Sciences, Gorgan, Iran.
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Singh A, Singh N, Behera D, Sharma S. Role of polymorphic XRCC6 (Ku70)/XRCC7 (DNA-PKcs) genes towards susceptibility and prognosis of lung cancer patients undergoing platinum based doublet chemotherapy. Mol Biol Rep 2018; 45:253-261. [PMID: 29397516 DOI: 10.1007/s11033-018-4158-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 01/30/2018] [Indexed: 01/06/2023]
Abstract
The DNA repair genes XRCC6 and XRCC7 formed an integral part of double strand break repair (DSBR) pathway. The two genes are thought to play an important role in the repair of lethal double strand damage on DNA. Polymorphic DSBR genes are studied to effect genomic stability. We intend to explore the association of DSBR genes i.e. XRCC6 and XRCC7 with susceptibility and survival in North Indian lung cancer patients. DNA isolation and genotyping was done for 320 controls and 330 lung cancer cases enrolled in the study. Each and every lung cancer study subjects were made a telephonic call and were followed for their health after administration of chemotherapy. Statistical analysis for susceptibility was done using logistic regression analysis. Survival analysis was done using Kaplan-Meier followed by Cox-regression. Small cell lung cancer (SCLC) subtype posed an amplified risk towards lung cancer in case of XRCC7 6721G>T (OR = 4.11, p = 0.0040). Gene-environment interaction analysis revealed that non-smokers with heterozygous genotype (CG) in case of XRCC6 61C>G showed a strong protective effect (OR = 0.38, p = 0.01) towards lung cancer. Survival analysis revealed poor prognosis in case of XRCC6 61C>G SCLC subtype. XRCC6 and XRCC7 were not involved in overall susceptibility and survival. However, in case of XRCC7 6721G>T subjects with SCLC subtype showed an increased susceptibility while poor prognosis in case of XRCC6 61C>G.
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Affiliation(s)
- Amrita Singh
- Department of Biotechnology, Thapar University, Patiala, Punjab, 147002, India
| | - Navneet Singh
- Department of Pulmonary Medicine, Post Graduate Institute of Medical Education and Research (PGIMER), Sector 14, Chandigarh, India
| | - Digambar Behera
- Department of Pulmonary Medicine, Post Graduate Institute of Medical Education and Research (PGIMER), Sector 14, Chandigarh, India
| | - Siddharth Sharma
- Department of Biotechnology, Thapar University, Patiala, Punjab, 147002, India.
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Jahantigh D, Moghtaderi A, Narooie-Nejad M, Mousavi M, Moossavi M, Salimi S, Mohammadoo-Khorasani M. Carriage of 2R allele at VNTR polymorphous site of XRCC5 gene increases risk of multiple sclerosis in an Iranian population. RUSS J GENET+ 2017. [DOI: 10.1134/s102279541612005x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Jahantigh D, Hosseinzadeh Colagar A. XRCC5 VNTR, XRCC6 -61C>G, and XRCC7 6721G>T Gene Polymorphisms Associated with Male Infertility Risk: Evidences from Case-Control and In Silico Studies. Int J Endocrinol 2017; 2017:4795076. [PMID: 28421111 PMCID: PMC5379132 DOI: 10.1155/2017/4795076] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2016] [Revised: 12/26/2016] [Accepted: 01/04/2017] [Indexed: 11/17/2022] Open
Abstract
We evaluate the association between genetic polymorphisms of XRCC5 VNTR, XRCC6 -61C>G, and XRCC7 6721G>T with male infertility susceptibility. A total of 392 men including 178 infertile males (102 idiopathic azoospermia and 76 severe oligozoospermia) and 214 healthy controls were recruited. XRCC6 -61C>G and XRCC7 6721G>T genotyping was performed by PCR-RFLP whereas XRCC5 VNTR was performed by PCR. The 2R allele and 2R allele carriers of XRCC5 VNTR polymorphism significantly decreased risk of male infertility. The mutant GG genotypes and carriers of the CG and GG genotypes of XRCC6 -61C>G showed increased risk for the male infertility. Furthermore, the G allele of the XRCC6 -61C>G was correlated with increased susceptibility to male infertility. Likewise, the T allele of the XRCC7 6721G>T polymorphism was associated with increased susceptibility to male infertility in azoospermia. In silico analysis predicted that the presence of tandem repeats in XRCC5 gene prompter can be sequence to bind to more nuclear factors. Also, rs2267437 (C>G) variant was located in a well-conserved region in XRCC6 promoter and this variation might lead to differential allelic expression. The XRCC7 6721G>T gene polymorphism occurred in an acceptor-splicing site, but this polymorphism has no severe modification on XRCC7 mRNA splicing. Our results indicate the association of XRCC5 VNTR, XRCC6 -61C>G, and XRCC7 6721G>T gene polymorphisms with male infertility in Iranian men.
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Affiliation(s)
- Danial Jahantigh
- Department of Molecular and Cell Biology, Faculty of Basic Sciences, University of Mazandaran, Babolsar, Iran
| | - Abasalt Hosseinzadeh Colagar
- Department of Molecular and Cell Biology, Faculty of Basic Sciences, University of Mazandaran, Babolsar, Iran
- *Abasalt Hosseinzadeh Colagar:
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Jahantigh D, Salimi S, Mousavi M, Moossavi M, Mohammadoo-Khorasani M, Narooei-nejad M, Sandoughi M. Association Between Functional Polymorphisms of DNA Double-Strand Breaks in Repair Genes XRCC5, XRCC6 and XRCC7 with the Risk of Systemic Lupus Erythematosus in South East Iran. DNA Cell Biol 2015; 34:360-6. [DOI: 10.1089/dna.2014.2465] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Affiliation(s)
- Danial Jahantigh
- Cellular and Molecular Research Center, Zahedan University of Medical Sciences, Zahedan, Iran
- Department of Biology, Sistan and Baluchestan University, Zahedan, Iran
| | - Saeedeh Salimi
- Cellular and Molecular Research Center, Zahedan University of Medical Sciences, Zahedan, Iran
- Department of Clinical Biochemistry, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran
| | | | - Maryam Moossavi
- Department of Biology, Sistan and Baluchestan University, Zahedan, Iran
| | - Milad Mohammadoo-Khorasani
- Cellular and Molecular Research Center, Zahedan University of Medical Sciences, Zahedan, Iran
- Department of Clinical Biochemistry, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran
| | - Mehrnaz Narooei-nejad
- Department of Genetics, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran
- Genetic of Non-Communicable Disease Research Center, Zahedan University of Medical Sciences, Zahedan, Iran
| | - Mahnaz Sandoughi
- Department of Internal Medicine, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran
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The rs7003908 (T>G) polymorphism in the XRCC7 gene and the risk of cancers. Mol Biol Rep 2014; 41:3577-82. [PMID: 24535266 DOI: 10.1007/s11033-014-3220-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2014] [Accepted: 01/28/2014] [Indexed: 02/05/2023]
Abstract
The association between the rs7003908 (T>G) polymorphism in the XRCC7 gene and the risk of cancers had been widely studied; however, the results were inconsistent. The objective of the current study was to investigate the association between the rs7003908 polymorphism in the XRCC7 gene and the risk of cancers by meta-analysis. We searched PubMed, EMbase, CNKI and Wanfang databases; the last search was performed on January 10th, 2014. Statistical analysis was performed using the Revman4.2 and STATA10.0 softwares. A total of 3,684 cancer cases and 5,232 controls from 11 case-control studies were included for data analysis. In the dominant model analysis, the results suggested a lack of association between the polymorphism and the risk of cancers: OR 1.01, 95% CI 0.83-1.16, P = 0.70. In the subgroup analysis by ethnicity, no significant association was found either for Asians or Caucasians. In the subgroup analysis by cancer types, significant association was found for prostate cancer, but not for bladder cancer, breast cancer and glioma. In summary, the current meta-analysis confirmed that the rs7003908 polymorphism in the XRCC7 gene might be a risk factor for prostate cancer. In the future, more studies are needed to validate these results.
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Gorre M, Mohandas PE, Kagita S, Annamaneni S, Digumarti R, Satti V. Association of XRCC5 VNTR polymorphism with the development of chronic myeloid leukemia. Tumour Biol 2013; 35:923-7. [PMID: 23982877 DOI: 10.1007/s13277-013-1120-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Accepted: 08/14/2013] [Indexed: 10/26/2022] Open
Abstract
Double-strand breaks (DSBs) inducing agents influence the fidelity of DNA repair in both normal cells and leukemic cells, causing major genomic instability. In eukaryotic cells, non-homologous end joining pathway (NHEJ) is the major mechanism for DSB repair. Human X-ray repair cross-complementing 5 (XRCC5) gene encodes for the protein KU86, an important component of NHEJ pathway. Variable number of tandem repeats (VNTR) polymorphism (rs 6147172) in the promoter region of XRCC5 gene was shown to have effect on gene expression and was found to be associated with the development of several cancers. We analyzed VNTR polymorphism of XRCC5 gene in 461 chronic myeloid leukemia (CML) cases and 408 controls by polymerase chain reaction. Our results showed that frequency of 0R/0R genotype was significantly elevated in CML cases compared to that of controls (p = 0.05). Significant difference in the genotype distribution was observed between cases and controls (p = 0.02). The risk of CML development was found to be elevated for individuals carrying lower repeats (1R p = 0.03; 0R p = 0.007). Elevated 0R/0R genotype frequency was found to be significantly associated with early age at onset (≤ 30 years) and slightly elevated in chronic phase and poor hematologic response to imatinib mesylate. The influence of zero repeat on enhanced expression of XRCC5 might confer risk to error-prone repair leading to genomic instability and CML. Hence, the VNTR polymorphism in the promoter region of XRCC5 gene could serve as an important prognostic marker in CML development.
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Affiliation(s)
- Manjula Gorre
- CSIR-SRF, Department of Genetics, Osmania University, Hyderabad, India,
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Xu H, Zou P, Chen P, Zhao L, Zhao P, Lu A. Association between the XRCC6 Promoter rs2267437 polymorphism and cancer risk: evidence based on the current literature. Genet Test Mol Biomarkers 2013; 17:607-14. [PMID: 23745766 DOI: 10.1089/gtmb.2013.0083] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Increasing evidence suggests that the DNA repair gene XRCC6 (Ku70) may be critically involved in the aetiology of the human carcinogenesis. Many studies have investigated the association between the rs2267437 polymorphism and cancer susceptibility. However, the results of these studies have been controversial. This meta-analysis was conducted to quantitatively summarize the evidence for a relationship between the rs2267437 polymorphism and cancer risk. METHODS Electronic databases, including PUBMED and EMBASE, were searched for publications that met the inclusion criteria. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to evaluate the strength of the association between the XRCC6 promoter rs2267437 polymorphism and cancer risk in a fixed-effects model (the Mantel-Haenszel method) or a random-effects model (the DerSimonian and Laird method), as appropriate. RESULTS A total of 13 case-control studies, involving 3675 cases and 4247 controls, investigating the XRCC6 rs2267437 polymorphism and cancer susceptibility were identified for the meta-analysis. The pooled analysis showed that there is a significant relationship between the XRCC6 rs2267437 polymorphism and cancer susceptibility (GG vs. CC: OR=1.28, 95% CI=1.03-1.60). Subgroup analyses based on the cancer type, ethnicity, and source of the controls were also performed, and these results indicated that the XRCC6 promoter rs2267437 polymorphism was associated with cancer risk in breast cancer studies (GG vs. CC: OR=1.79, 95% CI=1.25-2.56; GG vs. CG+CC: OR=1.40, 95% CI=1.01-1.95), in Asian populations (GG vs. CC: OR=1.33, 95% CI=1.01-1.74) and in population-based studies (GG vs. CC: OR=1.57, 95% CI=1.12-2.22; CG vs. CC: OR=1.35, 95% CI=1.11-1.64; GG+CG vs. CC: OR=1.37, 95% CI=1.14-1.65). CONCLUSION This meta-analysis suggests that the XRCC6 rs2267437 polymorphism may affect breast cancer susceptibility and increase the risk of cancer in Asian populations and in the general population. It is critical that further large-scale and well-designed studies be conducted to confirm the association between the rs2267437 genotype and cancer risk.
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Affiliation(s)
- Haitao Xu
- Department of Neurosurgery, The First Affiliated Hospital, Nanjing Medical University, Nanjing, China
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