Genetic Variation in CD166 Gene and Its Association with Bladder Cancer Risk in North Indian Population.

Adhesion molecules play a key role in cancer progression and tumorigenesis. Genetic polymorphism of adhesion molecules may alter the normal functioning thereby leading to bladder cancer susceptibility. Hence we aimed to evaluate three SNPs of CD166 gene (CD166rs6437585 C/T, CD166rs10511244 C/T, and CD166rs1157 A/G) in bladder cancer patients and normal controls of North Indian population. A total of 270 healthy controls and 240 confirmed bladder cancer patients were recruited for this study. Three SNPs of CD166 gene viz. CD166rs6437585 C/T, CD166rs10511244 C/T, and CD166rs1157 A/G were selected for this study. CD166rs6437585 C/T and CD166rs10511244 C/T were genotyped by Taqman allelic discrimination assay and CD166rs1157 A/G was genotyped by PCR-RFLP. The statistical analysis was done using the SPSS software, version 16.0 (SPSS, Chicago, IL), and p < 0.05 was considered statistically significant. Haplotypic analysis was done by using SNP analyzer version 1.2A. CD166rs6437585 C/T and CD166rs10511244 C/T showed significant association with reduced risk in bladder cancer while CD166rs1157 A/G showed significant high risk along with association at genotypic and allelic levels. Haplotypic analysis showed 1.8-folds risk in CCG combination, whereas CTA and TCG showed significant association with reduced risk. Further stratification on the basis of smoking, tumor grade/stage and BGC therapy revealed no association of these three polymorphic sites of CD166. Our study suggests that CD166rs6437585 C/T and CD166rs10511244 C/T are predictive for the reduced risk of bladder cancer, whereas CD166rs1157 A/G had shown significant association with high risk of bladder cancer in North Indians. This somehow suggests that CD166rs1157 A/G can be used as a marker for risk prediction of bladder cancer.