[Polymorphisms of mTORC1 genes and risk of primary colorectal adenocarcinoma in Chinese populations].

ABSTRACT

Objective: To study the associations between variants of mTORC1 of PI3K/AKT/mTOR pathway and colorectal cancer. Methods: In this hospital-based case-control study, at the First Affiliated Hospital, Xinjiang Medical University from 2000 to 2013, 665 primary colorectal cancer cases and 695 cancer-free controls were genotyped at 10 potentially functional single nucleotide polymorphism (SNPs) loci of mTORC1 (mTOR rs1034528, rs2295080; Raptor rs1062935, rs3751934; mLST8 rs3160, rs26865; DEPTOR rs2271900, rs4871827; AKT1S1 rs2290774, rs2353005) to assess their associations with risk of colorectal cancer by Logistic regression analysis. Results: In single-locus analysis, found a significantly decreased risk of colorectal cancer associated with mLST8 rs26865 by recessive genetic model, especially in populations of ≤68 years of age (OR=0.64; 95%CI=0.43-0.96, P=0.031), female (OR=0.61; 95%CI=0.38-0.99, P=0.046), non-smoking (OR=0.55; 95%CI=0.35-0.87, P=0.010). mTOR rs1034528 CC genotypes were associated with higher risk of colorectal cancer in >68-year-old populations (OR=3.34; 95%CI=1.12-9.91, P=0.030). Raptor rs3751934 CA/AA genotypes were associated with lower colorectal cancer risk in population of body mass index(BMI)>25 kg/m(2) (OR=0.68; 95%CI=0.47-0.98, P=0.038); and AKT1S1 rs2290774 CC genotypes were associated with lower colorectal cancer risk in non-smoking population (OR=0.67; 95%CI=0.45-0.99, P=0.048). Furthermore, found that populations carrying more than two low-risk genotypes were associated with lower colorectal cancer risk, compared with that of populations carrying less than two low-risk genotypes (OR=0.74, 95%CI=0.58-0.95, P=0.017), especially in population of ≤68 years of age, male and BMI>25 kg/m(2,) and non-smoking. Conclusions: SNPs of mTORC1-related genes individually or jointly contribute to colorectal cancer susceptibility in Chinese. Further studies of larger cohorts are needed to validate the findings.