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

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>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 < 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 D