Relationship between polymorphism of mismatch repair and metabolic enzyme genes and colorectal cancer

  Objective  To explore the relationship between single nucleotide polymorphisms (SNP) of mismatch repair gene (MMR) MLH1 rs1800734, MSH2 rs3732183 and metabolic enzyme gene UGT1A1 rs3755319, GSTM3 rs7483, DPYD rs1801159 and the risk of colorectal cancer for providing a molecular basis for diagnosis and treatment of colorectal cancer.

  Methods  We recruited 690 colorectal cancer patients hospitalized in Jiangsu Province Cancer Hospital during 2016 – 2017 as the cases and 431 healthy people having physical examination in Nanjing Kang′ai Hospital during the same period as the controls. Peripheral venous blood samples (2 mL for each participant) were collected for genotyping of relevant genes with TaqMan real-time PCR. The relationship between SNPs of the 5 gene loci and risk of colorectal cancer was analyzed using χ² test and logistic regression.

  Results  The ratios of MLH1 rs1800734 AA + GA and GG genotype carriers were 80.9% and 19.1% in the cases and the ratios were 85.8% and 14.2% in the controls. After adjusting for gender and age, GG genotype of MLH1 rs1800734 in recessive model was significantly associated with increased risk of colorectal cancer (odds ratio = 1.440, 95% confidence interval: 1.021 – 2.032; P = 0.038). No significant correlations were observed between SNPs of MSH2 rs3732183, UGT1A1 rs3755319, GSTM3 rs7483 and DPYD rs1801159 and colorectal cancer (both P > 0.05).

  Conclusion  The SNP of MLH1 rs1800734 is associated with the risk of colorectal cancer.