Polymorphisms In DNA Repair Genes Research Articles

Computational investigation unveils pathogenic LIG3 non-synonymous mutations and therapeutic targets in acute myeloid leukemia

Single nucleotide polymorphisms (SNPs) in DNA repair genes can impair protein structure and function, contributing to disease development, including cancer. Non-synonymous SNPs (nsSNPs) in the LIG3 gene are linked to genomic instability and increased cancer risk, particularly acute myeloid leukemia (AML). This study aims to identify the most deleterious nsSNPs in the LIG3 and potential therapeutic targets for DNA repair restoration in AML. We employed different computational approaches to analyze LIG3 nsSNPs and pathogenicity. Subsequently, molecular docking, molecular dynamics simulation (MDS), gene expression and clinical validation of LIG3 were performed to evaluate ligand-binding affinities, protein stability and to identify discriminatory gene signatures. Out of the 12,191 mapped SNPs, 132 were nsSNPs located in the coding region. Among these, 18 nsSNPs were identified as detrimental including 12 destabilizing and 6 stabilizing nsSNPs. Nine cancer-associated nsSNPs, including L381R and R528C, were predicted due to their structural and functional impacts. Further analysis revealed key phosphorylation and methylation sites, such as 529S and 224R. MDS highlighted stable interactions of compounds AHP-MPC and DM-BFC with wild-type and R528C mutant LIG3 proteins, while R671G and V781M mutants showed instability. Protein-protein interaction networks and functional enrichment linked LIG3 to DNA repair pathways. Kaplan-Meier analysis associated high LIG3 expression with improved survival in breast cancer and AML, suggesting its role as a prognostic biomarker. This study emphasizes the mutation-specific effects of LIG3 nsSNPs on protein stability and ligand interactions. We recommend identifying DM-BFC to advance personalized medicine approaches for targeting deleterious variants, following in-vitro and in-vivo validation for AML treatment.

Associations Between DNA Repair Gene Polymorphisms and Breast Cancer Histopathological Subtypes: A Preliminary Study.

Introduction: This study investigates the distribution and interaction of three polymorphisms-XRCC1 (rs1799782), CHEK2 (rs17879961), and XPD (rs238406)-in Romanian breast cancer patients, aiming to understand their association with histopathological subtypes, age, and BMI. Materials and Methods: This retrospective study analyzed 36 breast cancer patients from a Romanian clinic (2020-2024) with complete genetic data for XRCC1 (rs1799782), CHEK2 (rs17879961), and XPD (rs238406). The patients had invasive, non-metastatic breast cancer and no history of other cancers. Statistical analysis with Jamovi included descriptive stats, McNemar's test for genotype associations, and multinomial logistic regression to explore links between variants, age, BMI, and tumor subtypes. Results: McNemar tests showed no significant association between XRCC1 and CHEK2 (p = 0.180), nor between XRCC1 and XPD (p = 0.03) or XPD and CHEK2 (p = 0.049) after applying the Bonferroni correction (α = 0.0167), indicating no statistically significant genetic dependency among these variants. A multinomial logistic regression model found that genetic variants, BMI, and age significantly predicted breast cancer subtypes, particularly CDI TNB. All predictors remained significant in the comparisons of CDI TNB vs. CDI LB/CDI LA. Notably, these associations remained unchanged even after applying the Bonferroni correction (α = 0.0021), confirming the robustness of the findings. Conclusions: This study identifies significant associations between XRCC1, CHEK2, and XPD gene variants and CDI TNB, suggesting a role of DNA repair deficiencies in its pathogenesis. Protective genotypes were under-represented in TNB cases. Limited links with luminal subtypes highlight TNB's distinct genetic profile. Results support further research on these polymorphisms as markers for TNB risk and precision treatment.

Genome wide analyses reveal the role of mutator phenotypes in Mycobacterium tuberculosis drug resistance emergence

Antimicrobial combination therapy is widely used to combat Mycobacterium tuberculosis (Mtb), yet resistance rates continue to rise. Mutator strains, with defects in DNA repair genes, drive resistance in other bacterial infections, but their role in Mtb remains unclear. Here, we study the contribution of single nucleotide polymorphisms (SNPs) in DNA Repair, Replication, and Recombination (3 R) genes to Mtb resistance. Through large-scale bioinformatics analysis of 53,589 whole-genomes, we identified 18 novel SNPs in lineages 2 and 4 linked to genotypic drug resistance in 3 R genes, covering 12.5% of clinical isolates with available genome sequences. Notably, a number of the detected SNPs were positively selected during Mtb evolution. Experimental tests showed that mutM, fpgg2, xthA, and nucS mutants had increased the mutation frequency compared to the wild type. Our findings highlight the role of 3 R gene mutations in resistance, emphasizing the need for surveillance to improve early detection and control strategies.

Association between single nucleotide polymorphisms of DNA repair genes (BRCA1, BRCA2, and PALB2) and breast cancer incidence in a subset of Iranian population

BackgroundBreast cancer (BC) is the most common malignancy among Iranian females, accounting for 24.4% of all malignancies. Germ line mutations in DNA repair system-related genes are associated with an increased risk of BC. This study aims to evaluate the frequencies of single nucleotide polymorphisms (SNPs) in the BRCA1, BRCA2, and PALB2 genes in patients with BC from a subset of the Iranian population in the western part of Iran.MethodsBlood samples were collected from 335 patients with BC and 354 healthy matched volunteers. Genomic DNA was extracted using the salting-out method and, after quality control, was genotyped using the multiplex TaqMan allelic discrimination assay for three SNPs: rs80359550 (6174 delT) in the BRCA2 gene, rs180177102 in the PALB2 gene, and rs386833395 (185delAG) in the BRCA1 gene. Statistical analysis was performed to examine allele frequency, odds ratio, and relative risk (genetic association) in a retrospective case-control study.ResultsThe data showed no association between rs386833395 and BC risk in the studied population (odds ratio = 1), whereas rs80359550 and rs180177102 polymorphisms were strongly associated with BC risk in patients (odds ratio = 0.01 for both, with p-values of 0.011 and 0.021, respectively).ConclusionsOur findings suggest no significant association between the rs386833395 polymorphism and BC risk in the Iranian Kurdish population, while rs80359550 and rs180177102 polymorphisms were strongly associated with BC. However, the study has several limitations, including its retrospective design, a relatively small sample size, and the potential lack of generalizability to other ethnic groups within Iran. Future studies involving larger cohorts and more diverse populations are needed to confirm these results.

Association of XRCC1 (rs1799782) and XPD (rs13181) gene polymorphisms with renal failure risk in a sample of Iraqi population: a case-control study.

End-stage chronic kidney disease (CKD) can lead to life-threatening complications and is caused primarily by CKD and cardiovascular issues. CKD is characterized by the inability of the kidneys to filter waste and excess fluids from the blood. This study investigated the associations of the genetic variants XRCC1 rs1799782 (C194T) and ERCC2/XPD rs25487 (Q399R) with CKD susceptibility in Iraqi patients and related biochemical changes. The research was performed from 25/01/2023 to 30/06/2023, we analyzed the genetic associations of two SNPs of DNA repair genes (XRCC1 and ERCC2/XPD) in a case‒control study involving 219 CKD patients diagnosed by a nephrologist and 246 healthy controls. Data and blood samples were collected, and the genotype distribution frequency was determined via the PCR-based high-resolution melting (PCR-HRM) technique. This study included 465 participants, with 219 CKD patients and 246 healthy controls. XRCC1 and ERCC2/XPD gene polymorphisms were significantly associated with CKD susceptibility in Iraqi patients (p = 0.025 and p = 0.0001, respectively). Multivariate linear regression confirmed the associations of rs1799782 G/A and rs13181T/G with CKD, adjusting for sex, age, and BMI. Moderate and statistically significant linkage disequilibrium (0.43) between the two SNPs was observed, indicating nonrandom associations. XRCC1 (rs1799782) and ERCC2/XPD (rs13181) polymorphisms are associated with an increased risk of CKD. The AG haplotype model is particularly related to increased CKD susceptibility in Iraqi patients, suggesting the importance of these DNA repair gene polymorphisms in CKD risk assessment.

Meta-analysis of dna repair gene polymorphism in population living in areas with high radon levels

Lung cancer is one of the most common oncological diseases in the world. The World Health Organization identifies radon as the second most important risk factor for the development of this malignant neoplasm after smoking. The study of DNA repair gene polymorphisms plays a key role in uncovering the mechanisms of radon-induced carcinogenesis.The aim of this study was to assess whether OGG1 (rs1052133), ERCC1 (rs13181, rs11615, rs3212986), XRCC1 (rs25487), and XRCC3 (rs861539) gene polymorphisms are associated with the risk of radon-induced lung cancer.As part of the work, a meta-analysis was conducted to study the associations between these genetic polymorphisms and the likelihood of radon-induced lung cancer. Four studies, covering 1,648 patients with radon-induced lung cancer and 1,750 controls, were included in this meta-analysis. The results of the meta-analysis showed no significant association between the development of radon-induced lung cancer and the following polymorphisms: ERCC2 (rs13181), ERCC1 (rs11615), XRCC1 (rs25487).Statistically significant associations were found for the following genetic polymorphisms: OGG1 (rs1052133) in additive and dominant models; ERCC1 (rs3212986) in a recessive model; XRCC3 (rs861539) in recessive and dominant models. These results indicate a possible association of OGG1 (rs1052133), ERCC1 (rs3212986) and XRCC3 (rs861539) polymorphisms with predisposition to radon-induced lung cancer.

Mutagenicity, DNA Repair Gene Polymorphism, and Differentially Expressed Plasma Protein Fractions Among Textile Dyeing Workers.

This study aimed to assess mutagenicity biomarkers among Egyptian textile dyeing workers, their alteration with gene polymorphism, and the changes in plasma proteins' expression. Using a detailed questionnaire, a comparative cross-sectional study was conducted on 212 workers (106 textile dyeing-exposed group and 106 control group). CBMN-Cyt assay, ERCC2 gene polymorphism, and plasma protein fractions were analyzed in workers' blood samples. Textile dye workers had significantly higher mutagenicity biomarkers than the control group. Mutant ERCC2 genotypes, dye exposure, exposure period, and formaldehyde levels significantly predicted mutagenicity biomarkers' levels. Dye-exposed workers also showed significant changes in plasma protein fractions. Textile dyeing workers, particularly susceptible genotypes, are at mutagenic risk and have significant changes in plasma protein fractions. Those changes are usually the first detectable response to toxic exposures and can be useful as exposure biomarkers.

APEX1 Polymorphisms Affect Acute Myeloid Leukemia Risk, and Its Expression Is Involved in Cell Proliferation and Differentiation

ABSTRACTIntroductionThe link between DNA repair gene polymorphisms and cancer susceptibility has gained significant attention. Thus, we investigated the impact of base excision repair (BER) gene polymorphisms on acute myeloid leukemia (AML) risk and pathogenesis.MethodsIn total, 106 patients with AML and 191 healthy controls were included in the study, wherein polymorphisms in four BER genes (APEX1, MUTYH, OGG1, and XRCC1) were examined.ResultsNotably, the APEX1‐656 T>G polymorphism exhibited a significant association with AML risk in the recessive (TT vs. TG + GG) (p = 0.046) and co‐dominant models (TT vs. GG) (p = 0.02). Assessing APEX1 expression levels, APEX1 expression was elevated in the bone marrow of patients with AML compared with that in controls (p = 0.02). Subsequently, we compared the percentages of CD34+ cells between the APEX1 high or low expression groups, revealing a significant difference (high vs. low = 29.9% vs. 11.5%, p = 0.01). Additionally, we observed reduced APEX1 expression in HL60 cells differentiated with all‐trans retinoic acid (p < 0.001). We hypothesized that APEX1 expression could correlate with stemness and analyzed its expression in stem and differentiated cells.ConclusionsIn the GSE48558 dataset, AML cells and normal CD34+ cells expressed APEX1 at higher levels than did granulocytes (p < 0.01). Functional experiments revealed that APEX1 knockdown led to a reduction in AML cell proliferation. These findings indicated that APEX1 polymorphisms were a potential risk factor for AML and highlighted the important role of APEX1 in regulating AML cell differentiation and proliferation.

Host repair polymorphisms and H. pylori genes in gastric disease outcomes: Who are the guardian and villains?

Host repair polymorphisms and H. pylori genes in gastric disease outcomes: Who are the guardian and villains?

Polymorphisms in DNA Repair Genes as Biomarkers of Susceptibility for Pesticide-Induced DNA Damage among Agricultural Workers: A Review.

Pesticides induce oxidative DNA damage and genotoxic effects such as DNA single-strand breaks (SSBs), double-strand breaks (DSBs), DNA adducts, chromosomal aberrations, and enhanced sister chromatid exchanges. Such DNA damage can be repaired by DNA repair mechanisms. In humans, single nucleotide polymorphisms (SNPs) are present in DNA repair genes involved in base excision repair (BER) (OGG1, XRCC1, and APE1), nucleotide excision repair (NER) (XPC, XPD, XPF, XPG, and ERCC1), and double-strand break repair (DSBR) (XRCC4 and RAD51). This systematic review intends to provide information about occupational pesticide exposure, genotoxic effects of pesticides as well as association of DNA repair gene polymorphisms with the risk of pesticide-induced DNA damage. Polymorphisms present in DNA repair genes may influence interindividual variation in DNA repair capacity (DRC) by altering the functional properties of DNA repair enzymes and thus modulate DNA damage. The mechanisms of oxidative damage and disrupted DNA repair caused by the pesticides explain the link between pesticide exposure and adverse health outcomes. These polymorphisms in DNA repair genes could be used as biomarkers of susceptibility for pesticide-induced DNA damage among agricultural workers. It could also be useful as a preventive measure by identifying the genetic susceptibility of agricultural workers to pesticide-induced oxidative stress as well as pesticide poisoning.

Single Nucleotide Polymorphisms in APE1, hOGG1, RAD51 Genes and their Association with Radiotherapy Induced Toxicity among Head and Neck Cancer Patients.

Radiotherapy (RT) is a crucial treatment for head and neck cancer however, it causes adverse reactions to the normal tissue and organs adjacent to target tumor. The present study was carried out to investigate possible association of single nucleotide polymorphism in DNA repair genes with toxicity effects of radiotherapy on normal tissue. Three hundred and fifty head and neck cancer patients receiving radiotherapy treatment were enrolled in this study. The adverse after effects of radiotherapy on the normal tissue in the form of skin reactions were recorded. Single nucleotide polymorphisms of APE1 (rs1130409), hOGG1 (rs1052133) and Rad51 (rs1801320, rs1801321) genes were studied by polymerase chain reaction-Restriction fragment length polymorphism (PCR-RFLP) and direct DNA sequencing methods and their association with development of severe radio-toxicity effects was evaluated logistic regression analysis. The 172G/T polymorphism of Rad51 was 2.85 times higher and significantly associated with skin reactions (OR=2.85, 95% CI: 1.50-5.41; p=0.001) and severe oral mucositis (OR=4.96, 95% CI: 2.40-10.25; p<0.0001). These results suggested that the polymorphic nature of Rad51 is responsible for risk of radiotherapy adverse effects in HNC patients. The variant 326Cys and heterozygous 326Ser/Cys genotype of hOGG1 was significantly associated with high tumor grade (OR=3.16 95% CI: 1.66-5.99; p=0.0004, and OR=3.97 95% CI: 2.15-7.34; p=<0.0001 respectively). The homozygous variant 172TT genotype of Rad51 showed positive association with poor response of both tumor and nodes towards radiotherapy treatment (p=0.007 and p=0.022). Interpretation of our results revealed significant association of rs1801321 SNP of Rad51 with development of adverse toxicity reactions in normal tissue of head and neck cancer patients treated with radiotherapy.

Association between polymorphisms of DNA repair genes and intracranial aneurysms: A systematic review and meta‑analysis.

Intracranial aneurysms (IAs) are present in ~2% of the general population, and genetic factors cannot be excluded for the risk of their development. The gene factors that result in the changes in the vascular extracellular matrix (ECM) may also be a key reason for IAs being hereditary. The VCAN gene [also known as chondroitin sulfate proteoglycan 2 (CSPG2)] plays various roles in maintaining ECM functions. The present systematic review and meta-analysis aimed to investigate all eligible articles involving IAs on the association with germ line SNPs of DNA repair genes (up to January, 2024). The total number of patients was 2,308 [987 cases (poor outcomes) and 1,321 controls (good outcomes)]. The results revealed that rs2287926 G/G genotype and G allele and rs251124 T/T genotype and minor allele T increased the risk of developing IAs. However, further studies are required to examine these gene polymorphisms as screening markers for IAs.

Ethnic Differences, Lung Cancer Risk, and Association of NRF2 Gene Polymorphism with Gemcitabine-Based Chemotherapy

Introduction: The cancer burden is rising every year. Lung cancer is one of the most common cancers and non-small cell lung cancer is the most common type. Chemotherapy based on platinum drugs and third-generation nucleoside anti-metabolites such as gemcitabine are used widely. Gemcitabine has a complex metabolic pathway, with many mechanisms contributing to its cytotoxicity. Derangements in the metabolic pathway genes contribute to drug resistance and toxicity with this drug. Association studies including these genetic polymorphisms in the metabolic pathway, clinical outcomes, and cancer risk reported inter-individual differences. Thus, the aim of this study was to ascertain the role of these genetic variants in South Indian cancer patients treated with gemcitabine-based therapy.Methods: The study was done with 184 healthy volunteers for frequency establishment and 123 cancer patients were treated with gemcitabine-based chemotherapy for response and toxicity assessment. The participants were aged 18-65 years and resided in the southern states of India. DNA extraction was done from the leukocyte fraction of the blood by phenol-chloroform extraction procedures and genotyping was done by reverse transcription-polymerase chain reaction (RT-PCR) techniques to identify DNA repair gene polymorphisms. Tumor response was determined using Response evaluation criteria in solid tumors (RECIST) guidelines and toxicity using Common Terminology Criteria for Adverse Events (CTCAE), version 4.03. The patients were followed up for survival analysis.Results: The minor allele frequency of the single nucleotide polymorphism (SNP) NRF2-617 C>A (rs6721961) in the healthy population was 12.8%. SNPs were in Hardy-Weinberg equilibrium (p>0.05). Gender-based differences were not observed with the studied SNP in the healthy population and the lung cancer patients. These frequencies of NRF2 were found to be similar when compared to EUR (European) and all the South Asian subpopulations. They are significantly divergent compared to AFR (African), AMR (American), and EAS (East Asian) populations. The minor allele frequency in cancer patients was found to be 14.2% and the lung cancer risk with the SNP studied could not be detected. There was no association found with the response, toxicity, and survival among lung cancer patients.Conclusion: NRF2, being a multifaced molecule, did not show a significant association with lung cancer risk, response, and toxicity in patients with gemcitabine-based chemotherapy.

X-ray Repair Cross Complementing 1 (XRCC1) Gene Polymorphism in Hepatocellular Carcinoma (HCC)

Abstract Background Several risk factors for hepatocellular carcinoma (HCC) have been identified, including chronic infection of hepatitis B virus (HBV) and hepatitis C virus (HCV). Nevertheless, only a fraction of infected patients develops HCC during their lifetime suggesting that genetic factors might modulate HCC development. The human X-ray repair cross- complementing protein 1 (XRCC1) gene encodes for one of the major repair factors involved in base excision repair (BER), which is reported to be associated with the risk of several cancers. A few studies have explored the association between risk of hepatocellular carcinoma (HCC) and single-nucleotide polymorphisms (SNPs) in different DNA repair genes. Aim of the Work to investigate the possible association between XRCC1-G28152A (rs25487) single nucleotide polymorphism (SNP) and hepatocellular carcinoma (HCC) in chronic hepatitis C patients. Patients and Methods The study included 35 patients who had HCC and 15 patients who had liver cirrhosis. XRCC1 gene polymorphism was done to all participants by RT-PCR After collection of relevant clinical data and basic laboratory tests. Results A statistically higher frequency of XRCC1 (GG, GA) genotypes and increased (G) allele frequency in patients with HCC was found in comparison to cirrhotic HCV patients as well as control group but Our results revealed that the genotypic and allelic frequencies of XRCC1 gene polymorphism rs25487 didn’t show statistically significant difference between HCC patients group and liver cirrhosis control group. Conclusion The present study had demonstrated that there was no significant association between XRCC1 gene polymorphism (rs25487) and HCC in the sample of Egyptian population included in our study. Also, non-significant differences among the XRCC1 genotypes and alleles were found regarding age, sex, BMI and laboratory data including CBC, AFP, coagulation profile (PT, INR), liver function test ( total protein, albumin, AST, total bilirubin and direct bilirubin), BCLC and Milan criteria. While a statistically significant difference was observed as regards PTT and ALT between genotypes.

Influence of genetic polymorphisms of Hg metabolism and DNA repair on the frequencies of micronuclei, nucleoplasmic bridges, and nuclear buds in communities living in gold mining areas

Influence of genetic polymorphisms of Hg metabolism and DNA repair on the frequencies of micronuclei, nucleoplasmic bridges, and nuclear buds in communities living in gold mining areas

Polymorphisms of DNA Repair Genes in Thyroid Cancer.

The incidence of thyroid cancer, one of the most common forms of endocrine cancer, is increasing rapidly worldwide in developed and developing countries. Various risk factors can increase susceptibility to thyroid cancer, but particular emphasis is put on the role of DNA repair genes, which have a significant impact on genome stability. Polymorphisms of these genes can increase the risk of developing thyroid cancer by affecting their function. In this article, we present a concise review on the most common polymorphisms of selected DNA repair genes that may influence the risk of thyroid cancer. We point out significant differences in the frequency of these polymorphisms between various populations and their potential relationship with susceptibility to the disease. A more complete understanding of these differences may lead to the development of effective prevention strategies and targeted therapies for thyroid cancer. Simultaneously, there is a need for further research on the role of polymorphisms of previously uninvestigated DNA repair genes in the context of thyroid cancer, which may contribute to filling the knowledge gaps on this subject.

The Role of DNA Repair (XPC, XPD, XPF, and XPG) Gene Polymorphisms in the Development of Myeloproliferative Neoplasms.

Background and Objectives: Several polymorphisms have been described in various DNA repair genes. Nucleotide excision DNA repair (NER) detects defects of DNA molecules and corrects them to restore genome integrity. We hypothesized that the XPC, XPD, XPF, and XPG gene polymorphisms influence the appearance of myeloproliferative neoplasms (MPNs). Materials and Methods: We investigated the XPC 1496C>T (rs2228000, XPC Ala499Val), XPC 2920A>C (rs228001, XPC Lys939Gln), XPD 2251A>C (rs13181, XPD Lys751Gln), XPF-673C>T (rs3136038), XPF 11985A>G (rs254942), and XPG 3507G>C (rs17655, XPG Asp1104His) polymorphisms by polymerase chain reaction-restriction fragment length polymorphism analysis in 393 MPN patients [153 with polycythemia vera (PV), 201 with essential thrombocythemia (ET), and 39 with primary myelofibrosis (PMF)] and 323 healthy controls. Results: Overall, we found that variant genotypes of XPD 2251A>C were associated with an increased risk of MPN (OR = 1.54, 95% CI = 1.15-2.08, p = 0.004), while XPF-673C>T and XPF 11985A>G were associated with a decreased risk of developing MPN (OR = 0.56, 95% CI = 0.42-0.76, p < 0.001; and OR = 0.26, 95% CI = 0.19-0.37, p < 0.001, respectively). Conclusions: In light of our findings, XPD 2251A>C polymorphism was associated with the risk of developing MPN and XPF-673C>T and XPF 11985A>G single nucleotide polymorphisms (SNPs) may have a protective role for MPN, while XPC 1496C>T, XPC 2920A>C, and XPG 3507G>C polymorphisms do not represent risk factors in MPN development.

Abstract B086: Association of breast cancer-relevant DNA repair genes with postmenopausal breast cancer risk in UK Biobank

Abstract Purpose. Several polymorphisms have been described in DNA damage signaling and repair genes and some of the polymorphisms have been implicated in genetic susceptibility to breast cancer. However, there is no consensus result yet for most of these polymorphisms. In this study, we focused on evaluating selected SNPs in BRCA1, BRCA2, ATM, XRCC1, XRCC2, XRCC3, and XPD (ERCC2) genes that have been previously reported to be associated with breast cancer risk and are available in the UK Biobank. Methods. This study included 150,929 postmenopausal women (5,969 with BCa) from UK Biobank, a population-based prospective cohort. Cancer diagnoses were ascertained through the linkage to the UK National Health Service Central Registers. DNA was extracted from blood samples collected from participants at enrollment in UK Biobank. Samples were genotyped using the Applied Biosystems UK BiLEVE Axiom Array or the Applied Biosystems UK Biobank Axiom Array. The positions of markers in the data are in GRCh37 coordinates. SNPs with frequency &amp;lt; 1% in the study population were excluded from analyses. We included the following SNPs in the final analyses: XRCC3-rs861539, BRCA1-rs16942, BRCA1-rs4986852, XRCC1-rs25487, XRCC1-rs25489, XRCC1-rs1799782, XPD (ERCC2)-rs13181, XPD (ERCC2)-rs1799793, XRCC2-rs3218536, ATM-rs1800056, ATM-rs1800057, BRCA2-rs144848, BRCA2-rs4987117, and BRCA2-rs11571833. Information on breast cancer risk factors was collected at baseline. Cox proportional hazards regression models were used to analyze the association between each SNP and breast cancer risk while adjusting for known breast cancer risk factors. The risk estimates were presented as hazard rations (HRs) and their corresponding 95% confidence intervals (CIs). Results. The mean age of the study population at enrollment was 60.1 years (range 40-71 years). Heterozygous carriers of BRCA2-rs11571833 T allele were found to have an increased risk of breast cancer (HR=1.22, 95% CI 1.02, 1.46, p-trend = 0.033) compared to the homozygous carriers of the BRCA2-rs11571833 A allele. No other significant associations between other SNPs and breast cancer risk were found. Conclusions. We found a significant association between SNP BRCA2-rs11571833 and postmenopausal breast cancer risk. Our findings contribute to the existing evidence on the association of high-risk polymorphisms in DNA damage signaling and repair genes with postmenopausal breast cancer risk. Citation Format: Carmen Smotherman, Brian Sprague, Dejana Braithwaite, Huaizhen Qin, Lusine Yaghjyan. Association of breast cancer-relevant DNA repair genes with postmenopausal breast cancer risk in UK Biobank [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Breast Cancer Research; 2023 Oct 19-22; San Diego, California. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_1):Abstract nr B086.

Abstract A030: DNA repair gene polymorphism(s): Association with relapse of oral squamous cell carcinoma

Abstract Differences in DNA repair capacity have been linked to the risk and prognosis of cancer. In specific types of cancer, certain variations known as Single Nucleotide Polymorphisms (SNPs) within DNA repair genes can influence the effectiveness of treatments. This phenomenon has been observed in patients with Oral Squamous Cell Carcinoma (OSCC), especially in those undergoing chemotherapy and radiation therapy. One such gene, Excision Repair Cross-Complementation 5 (ERCC5), contains a SNP (rs17655) G&amp;gt;C, leading to a missense variation and a change in amino acid from D to H. This variation has been noted in various cancer types. Hence, this study aimed to investigate the presence of this DNA repair gene polymorphism (rs17655) and its association with OSCC. To achieve this goal, blood samples were collected from OSCC patients exposed to chemotherapy and radiation therapy, as well as from OSCC patients not exposed to these treatments, following approval from the relevant institutional review committees. Informed consent was obtained from 100 patients, and an equal number of age and gender-matched controls. Genomic DNA was extracted using the salting-out method and analyzed for quality and quantity through agarose gel electrophoresis and nanodrop spectrophotometry. Primers were designed using online primer designing software. Genetic variations were identified using Tetra Primers-Amplifies Refractory Mutation System Polymerase Chain Reaction (t-ARMS PCR), and the amplified products were visualized via agarose gel electrophoresis. The genotypic frequency analysis of rs17655 revealed a higher prevalence of the homozygous mutant type (CC) in the blood samples of OSCC patients, both exposed and non-exposed to chemotherapy and radiation therapy. In contrast, the homozygous wild type (GG) was more prevalent among the control group. Statistical analysis, including a chi-square test (χ 2 = 36.76, p &amp;lt; 0.001) and odds ratio (10.27), demonstrated a significant association between the rs17655 polymorphism and oral squamous cell carcinoma, indicating an increased risk of OSCC due to this genetic variation. These genomic variants have the potential to serve as biomarkers for predicting clinical outcomes in OSCC patients undergoing chemotherapy and radiotherapy. Citation Format: Umaiya Abdali, Saima Saleem. DNA repair gene polymorphism(s): Association with relapse of oral squamous cell carcinoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: DNA Damage Repair: From Basic Science to Future Clinical Application; 2024 Jan 9-11; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2024;84(1 Suppl):Abstract nr A030.

Abstract B034: Polymorphisms in XRCC1 Arg399Gln and XRCC3 Thr241Met DNA repair genes elevate cervical cancer risk among Bangladeshi female population

Abstract Introduction and Objective: Cervical cancer is the second most common cancer in women worldwide and is both a preventable and a curable disease especially if identified at an early stage. Sequence variations in DNA repair genes can cause aberration in cellular functions leading to cancer. Genetic polymorphisms in XRCC1 (Arg399Gln) and XRCC3 (Thr241Met) genes result in individual variation in their DNA repair capacity. The aim of this study was to identify the association between XRCC1 Arg399Gln and XRCC3 Thr241Met single nucleotide polymorphisms (SNPs) and susceptibility to cervical cancer in Bangladeshi populations. Methods: The case-control study comprised 124 cervical cancer patients and 148 healthy controls. Genomic DNAs were isolated from peripheral blood and genotyped for candidate SNPs using polymerase chain reaction-restriction fragment length polymorphism (PCR–RFLP) method. Results: For XRCC1, heterozygous Arg/Gln and combined heterozygous plus variant homozygous Gln/Gln genotypes showed 1.78-fold (95% CI 1.0037 to 2.8771, p=0.0484) and 1.8627-fold (95% CI 1.1470 to 3.0250, p = 0.0119) increased risk of cervical cancer, respectively, when compared with normal homozygous Arg/Arg genotype. The variant Gln allele was positively associated with cervical cancer by 1.68-fold increase (95% CI 1.1732 to 2.3980, p = 0.0046). Similarly, for XRCC3, Thr/Met heterozygous and combined Thr/Met + Met/Met genotypes were found to be associated with 1.6993-fold (95% CI 1.0398 to 3.0166, p=0.0354) and 1.8312-fold (95% CI 1.0890 to 3.0791, p = 0.0225) higher risk, respectively, when compared with normal homozygous Thr/Thr genotypes. The variant Met allele showed significant association with 1.71-fold increased risk. Conclusion: XRCC1 (Arg399Gln) and XRCC3 (Thr241Met) polymorphisms may be associated with increased cervical cancer risk in Bangladeshi females. Citation Format: Md. Mustafizur Rahman, Laboni Das, Sadia Rahman, Amir Hossain, Razia Sultana. Polymorphisms in XRCC1 Arg399Gln and XRCC3 Thr241Met DNA repair genes elevate cervical cancer risk among Bangladeshi female population [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: DNA Damage Repair: From Basic Science to Future Clinical Application; 2024 Jan 9-11; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2024;84(1 Suppl):Abstract nr B034.