Novel association between heterozygous genotype of single nucleotide polymorphism C218T in drug transporter ABCC1 gene and increased risk of colon cancer

Abstract

Objectives: To determine the role of G128C and C218T variants in ABCC1 gene with the risk of developing colon cancer in Jeddah, Kingdom of Saudi Arabia. Methods: This case-control study was conducted on 51 colon cancer patients and 65 controls from King Abdulaziz University Hospital and King Abdullah Medical City in the period from January 2015 to April 2017, and was approved by the Unit of Biomedical Ethics (no: 261-15). Experiments were performed in the experimental biochemistry unit at King Fahd Medical Research Center. The genotype distributions and allele frequencies were determined by polymerase chain reaction-restriction fragments length polymorphism (PCR-RFLP) and DNA sequencing. A Chi-square test was used to determine allele and genotype distributions, odds ratio (OR), risk ratio (RR) and 95% confidence intervals (CI). P-values of <0.05 were considered statistically significant. Results: The results showed a novel association between heterozygous (CT) genotype for variant C218T and increased risk of colon cancer [OR=3.4, 95% CI (1.56-7.48), and RR=1.92, 95% CI (1.26-2.93), p=0.002]. These ratios were correlated with high-grade stages (III and IV). In contrast, for variant G128C, there was no significant association with the risk of developing colon cancer. Conclusion: The novel findings of the study revealed that the CT genotype of variant C218T in ABCC1 gene may increase the risk of developing colon cancer.