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The Contribution of Flap Endonuclease 1 Genotypes to Oral Cancer Risk

Background/Aim: Flap endonuclease 1 (FEN1) is a critical protein in DNA repair, genomic stability, and carcinogenesis. Functional polymorphisms in FEN1 promoter −69G>A (rs174538) and 3′UTR 4150G>T (rs4246215), have been associated with the susceptibility to several cancers, including lung, breast, esophageal, gastric, liver, colorectal, and gallbladder cancer, as well as glioma, endometriosis, and leukemia. However, the contribution of FEN1 variant genotypes to oral cancer has never been examined. Thus, we aimed to evaluate the contribution of FEN1 rs174538 and rs4246215 genotypes to oral cancer risk in Taiwan. Materials and Methods: The contribution of FEN1 genotypes to oral cancer risk was examined in 958 oral cancer patients and 958 age- and sex-matched healthy controls by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Results: The percentages of GG, AG, and AA genotypes at FEN1 rs174538 were 34.8%, 46.0%, and 19.2% among oral cancer patients and 37.8%, 45.2%, and 17.0% among healthy controls (p for trend=0.2788). The genotypic percentages of FEN1 rs4246215 were 35.9%, 45.9%, and 18.2% among oral cancer patients and 37.6%, 45.1%, and 17.3% among healthy controls (p for trend=0.7315). Overall, FEN1 rs174538 and rs4246215 were not differently distributed between the oral cancer patient and healthy control groups. The allele frequency analysis confirmed that FEN1 rs174538 and rs4246215 were non-differentially distributed among case and control groups (OR=1.11 and 1.05, 95%CI=0.98-1.27 and 0.93-1.20, p=0.1074 and 0.4491, respectively). Conclusion: FEN1 may contribute to oral cancer risk determination via protein expression and/or post-transcription modification, but may not be a practical genetic marker.