A genetic variant in miR-146a modifies colorectal cancer susceptibility in a Chinese population.

MicroRNAs (miRNAs) are a family of endogenous, small, noncoding RNA molecules that involved in a wide range of biological processes including differentiation, proliferation, and apoptosis. A polymorphism G>C (rs2910164) is located in the stem region opposite to the mature miR-146a sequence. In our study, we investigated whether rs2910164 is associated with the risk of colorectal cancer (CRC) in a Chinese population. We genotyped the rs2910164 polymorphism using TaqMan method and evaluated the association with CRC risk in a case-control study, including 1,147 CRC patients and 1,203 cancer-free controls. Logistic regression models were used to assess the genetic effects on the development of CRC. Overall, we found that rs2910164 was significantly associated with the reduced CRC risk [GC/CC versus GG: adjusted odds ratio (OR) = 0.78, 95 % confidence intervals (CIs) = 0.66-0.93]. In the stratification analysis, this decreased risk was also pronounced among non-smokers (0.75, 0.61-0.93), non-drinkers (0.77, 0.63-0.94), and no family history of cancer (0.79, 0.65-0.95). Furthermore, GC/CC genotypes were associated with reduced CRC susceptibility in intermediate differentiated CRC (0.75, 0.62-0.90), and similar effect was observed in patients with the advanced stage tumor (Dukes C and D) (0.76, 0.61-0.93). In conclusion, our results suggest that miR-146a rs2910164 may contribute to the susceptibility to CRC in a Chinese population. Further larger population-based prospective and functional studies are needed to validate our findings.