The Association between Cyclin D۱ (CCND۱) rs۹۳۴۴ AA Genotype and Increased Risk of Colorectal Cancer in An Iranian Population

Background: Colorectal cancer (CRC) is a globally growing disease with a steady decrease in the age of incidence. Pathogenesis of this cancer stems from a complex interaction between environmental factors and genetic predisposition. Among genetic factors, high activity of cyclin D۱gene is prominent. A polymorphism (G۸۷۰A) in exon ۴ of cyclin D۱ is responsible for a variant transcript with longer half-life and may culminate in uncontrollable cellular growth, thereby contributing to cancer development. Method: This case-control study evaluated the frequency of CCND۱ G۸۷۰A polymorphism and risk of sporadic CRC in an Iranian population. The study population comprised ۵۰ CRC patients and ۵۰ CRC-free controls selected on the basis of colonoscopy examination. For genotyping, we performed polymerase chain reaction – restriction fragment length polymorphism analysis (PCR-RFLP). Result: AA genotype frequencies compared to GA+GG genotype frequencies between cases and controls showed that AA genotype frequency in the case group was significantly higher than the control group (AA vs. GG + GA: OR= ۲.۲۵, ۹۵% CI: ۱.۱۳-۵.۵۴, P=۰.۰۴). Allele A frequency was ۵۷% in patients and ۴۶% in healthy subjects. Statistical analysis showed that the odds ratio of carriers with allele A for risk of CRC was ۱.۵۵ more than G allele carriers (OR=۱.۵۵, ۹۵% CI: ۰.۸۵۶-۲.۸۲۸). Moreover, physical activity in cases was significantly less than controls (P=۰.۰۰۱). We further observed that the subjects in the case group used fewer non-steroidal antiinflammatory drugs compared to healthy controls (P=۰.۰۲). Analysis of body mass index (BMI) between cases and controls revealed that the average of BMI in cases was higher than the controls (P =۰.۰۴). Conclusion: Our results showed that individuals carrying the AA genotype ran a higher risk of developing CRC compared to GG genotype.