Polymorphism Of XRCC5、XRCC6 And BRAF Mutation In Papillary Thyroid Carcinoma

Background:The morbidity of Papillary Thyroid Carcinoma had grown rapidly in our country recent years, it has increased from 1/10 to 3-4/10.Papillary thyroid carcinoma is the most common pathological pattern of thyroid malignant tumor roughly account for 80% of the total. Environmental and genetic factors as tumor pathogenic factors reinforce each other. On the one hand, Ionizing radiation is a specific environmental factor to papillary thyroid carcinoma, which can cause lethal DNA double-strand break; on the other hand, Gene point mutation and chromosome rearrangement is considered as a genetic molecular mechanisms take participate in thyroid cancer occurrence and development, of which the cancer gene BRAF V600E point mutation was widely researched. Besides, the DSB repair gene single nucleotide polymorphisms (SNP) become focus in thyroid cancer genetic predisposition factors research. To investigate the correlation between DSB repairing gene polymorphism has positive guidance to papillary thyroid cancer early diagnosis and risk assessment. Making an association analysis between candidate genes SNPs involving the pathway of DSB and the BRAF mutation has important implications for the further exploration and to reveal the mechanism of PTC, therefore we select XRCC5, XRCC6 as the research object of DSB repair gene polymorphism and investigate whether correlation exist between the polymorphism and mutated BRAF mutation.Objective:To investigate the association between XRCC5.XRCC6 gene polymorphisms and papillary thyroid carcinoma susceptibility. SNPs of repair genes associated with BRAF mutations are sought to provide a new molecular target for the diagnosis and treatment of PTC. At the same time, predicting the risk of BRAF mutation not only can provide a theoretical basis for clinical treatment but also avoid excessive and inadequate treatment, provide theoretical basis for improving prognosis.Methods:A hospital-based case only study designed and analyzed the relationship between papillary thyroid carcinoma and XRCC5. XRCC6 gene polymorphism.We intend to apply the method of molecular epidemiology, using the existing samples to extract DNA, and using the PCR technology to carry out gene typing.Results:1. XRCC5 gene locus (rs2160981) genotypes in BRAF wild type and mutant type has a differences statistically significant between the two groups (X2: 9.267;P: 9.267), The allele frequencies between the two group were -statistically significant(X2: 7.262; P: 7.262).2. XRCC6 gene locus (rs2160981) genotypes in BRAF wild type and mutant type has a differences statistically significant between the two groups (X2: 7.067;P: 0.008), beside the result show a statistically significant differences (X2:6.563;P:0.001) of allele frequencies between the two groups.Conclusion:XRCC5, XRCC6 polymorphisms (SNPs) in DNA repair pathways may have association with BRAF mutation for papillary thyroid carcinoma (PTC).