title: Lack of associations between Vitamin D metabolism-related gene variants and risk of colorectal cancer.
abstract: OBJECTIVE
  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).
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Gastroenterology and Liver Diseases Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran E-mail : mahmouditouraj@gmail.com.
authors.forename: Touraj
authors.initials: T
authors.lastname: Mahmoudi
authors.forename: Khatoon
authors.initials: K
authors.lastname: Karimi
authors.forename: Maral
authors.initials: M
authors.lastname: Arkani
authors.forename: Hamid
authors.initials: H
authors.lastname: Farahani
authors.forename: Hossein
authors.initials: H
authors.lastname: Nobakht
authors.forename: Reza
authors.initials: R
authors.lastname: Dabiri
authors.forename: Asadollah
authors.initials: A
authors.lastname: Asadi
authors.forename: Mohsen
authors.initials: M
authors.lastname: Vahedi
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Zali
mesh_terms: D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase / Q000235:genetics; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics*; D016022:Case-Control Studies; D053493:Cholestanetriol 26-Monooxygenase / Q000235:genetics; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology; D000072467:Cytochrome P450 Family 2; D005260:Female; D005500:Follow-Up Studies; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011110:Polymorphism, Genetic / Q000235:genetics*; D011379:Prognosis; D018167:Receptors, Calcitriol / Q000235:genetics; D012307:Risk Factors; D014807:Vitamin D / Q000378:metabolism*; D014809:Vitamin D-Binding Protein / Q000235:genetics; D014815:Vitamins / Q000378:metabolism; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D018167:Receptors, Calcitriol; C579457:VDR protein, human; D014809:Vitamin D-Binding Protein; D014815:Vitamins; D014807:Vitamin D; D000072467:Cytochrome P450 Family 2; C506833:CYP2R1 protein, human; D053493:Cholestanetriol 26-Monooxygenase; D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase