Lack of Associations between Vitamin D Metabolism-Related Gene Variants and Risk of Colorectal Cancer

• DOI: 10.7314/apjcp.2014.15.2.957
• Publication Date: 2014-07-01T14:40:29Z
• Authors: Touraj Mahmoudi; Khatoon Karimi; Maral Arkani; Hamid Farahani; Hossein Nobakht; Reza Dabiri; Asadollah Asadi; Mohsen Vahedi; Mohammad Reza Zali
• Keywords: 25-Hydroxyvitamin D3 1-alpha-Hydroxylase; Adult; Aged, 80 and over; Male; 0303 health sciences; Polymorphism, Genetic; Genotype; Middle Aged; Prognosis; 3. Good health; 03 medical and health sciences; Case-Control Studies; Biomarkers, Tumor; Cholestanetriol 26-Monooxygenase; Humans; Receptors, Calcitriol; Female; Genetic Predisposition to Disease; Colorectal Neoplasms; Cytochrome P450 Family 2; Aged; Follow-Up Studies; Neoplasm Staging

With regard to the protective effect of vitamin D against colorectal cancer (CRC), we evaluated genetic variants that might influence vitamin D metabolism: vitamin D receptor (VDR), vitamin D binding protein (GC), vitamin D 25-hydroxylase (CYP2R1), and vitamin D 25-hydroxy 1-alpha hydroxylase (CYP27B1).A total of 657 subjects, including 303 cases with CRC and 354 controls were enrolled in this case-control study. All 657 were genotyped for the four gene variants using PCR-RFLP methods.In this study, no significant difference was observed for VDR (rs2238136), GC (rs4588), CYP2R1 (rs12794714), and CYP27B1 (rs3782130) gene variants in either genotype or allele frequencies between the cases with CRC and the controls and this lack of difference remained even after adjustment for age, BMI, sex, smoking status, NSAID use, and family history of CRC. Furthermore, no evidence for effect modification of the variants and CRC by BMI, sex, or tumor site was observed.Our findings do not support a role for VDR, GC, and CYP27B1 genes in CRC risk in our Iranian population. Another interesting finding, which to our knowledge has not been reported previously, was the lack of association with the CYP2R1 gene polymorphism. Nonetheless, our findings require confirmation and possible roles of vitamin D metabolism-related genes in carcinogenesis need to be further investigated.