Cytochrome P450 1A1, 2E1 and GSTM1 Gene Polymorphisms and Susceptibility to Colorectal Cancer in the Saudi Population

Background: The Saudi population has experienced a sharp increase in colorectal and gastric cancer incidenceswithin the last few years. The relationship between gene polymorphisms of xenobiotic metabolizing enzymesand colorectal cancer (CRC) incidence has not previously investigated among the Saudi population. The aimof the present study was to investigate contributions of CYP1A1, CYP2E1, and GSTM1 gene polymorphisms.Materials and
Methods: Blood samples were collected from CRC patients and healthy controls and genotypeswere determined by polymerase chain reaction restriction fragment length polymorphism and sequencing.Results and
Conclusions: CYP2E1*6 was not significantly associated with CRC development (odd ratio=1.29;confidence interval 0.68-2.45). A remarkable and statistically significant association was observed amongpatients with CYP1Awt/*2A (odd ratio=3.65; 95% confidence interval 1.39-9.57). The GSTM1*0/*0 genotypewas found in 2% of CRC patients under investigation. The levels of CYP1A1, CYP2E1 and GSTM1 mRNAgene expression were found to be 4, 4.2 and 4.8 fold, respectively, by quantitative real time PCR. The results ofthe present case-control study show that the studied Saudi population resembles Caucasians with respect to theconsidered polymorphisms. Investigation of genetic risk factors and susceptibility gene polymorphisms in ourSaudi population should be helpful for better understanding of CRC etiology.