Interaction Between XRCC1 Gene Polymorphisms and Obesity on Susceptibility to Papillary Thyroid Cancer in Chinese Han Population.

BACKGROUND/AIMS: To investigate the association of several single nucleotide polymorphisms (SNPs) within XRCC gene and additional gene- environment interaction with papillary thyroid cancer (PTC) risk.

METHODS

Testing for Hardy-Weinberg equilibrium in controls was conducted using SNPstats (online software: http://bioinfo.iconcologia.net/SNPstats). Generalized multifactor dimensionality reduction (GMDR) was used to screen the best interaction combination among 5 SNPs within XRCC gene and obesity.

RESULTS

Logistic regression analysis showed that the C allele of rs861539 and T allele of rs1799782 were associated with increased PTC risk Adjusted ORs (95%CI) were 1.65 (1.23-2.12) and 1.61 (1.20-2.04). However There was no relation of rs25489 Rs25487 and rs13181 with PTC. The cross-validation consistency and the testing accuracy for each of the models were determined by GMDR analysis. One two-locus model (rs1799782 and obesity) had a testing accuracy of 62.11% Which was significant at the p < 0.01 level. The D' value between rs1799782 and rs13181 within ERCC1 gene was more than 0.75 (0.825). So haplotype analysis was just conducted for rs1799782 and rs13181 using the SHEsis online haplotype analysis software. In all samples The haplotype C- A was observed most frequently in two groups With 49.46% and 55.79% in the PTC patients and controls Respectively. The results also indicated that haplotype T- C was significantly associated with increased PTC risk.

CONCLUSION

The C allele of rs861539 and T allele of rs1799782 Interaction between rs1799782 and obesity and haplotype T- C were all associated with increased PTC risk.