Vitamin D receptor FokI gene polymorphisms may be associated with colorectal cancer among African American and Hispanic participants
Menée en population afro-américaine et hispanique aux Etats-Unis à partir d'échantillons sanguins prélevés sur 78 patients atteints d'un cancer colorectal et sur 300 témoins (230 sans polypes, 70 avec polypes), cette étude évalue l'association entre des polymorphismes du gène VDR et le risque de développer la maladie
BACKGROUND : Vitamin D plays a role in cancer tumorogenesis and acts through the vitamin D receptor (VDR). Although African Americans have the lowest serum vitamin D levels, supplementation has not yielded a significant improvement in cancer. Gene polymorphisms in VDR may play a role. There is a dearth of information on VDR gene polymorphisms and colorectal cancer (CRC) among under-represented ethnic groups. In this study, the authors examined whether VDR gene single nucleotide polymorphisms (SNPs) were associated with CRC in predominately African American and Hispanic study participants. METHODS : Blood samples were collected from 378 participants, including a group of 78 patients with CRC (cases), a group of 230 noncancer participants without polyps (controls without polyps), and a group of 70 noncancer participants with polyps (controls with polyps). The 4 polymorphic SNPs in VDR (FokI, BsmI, TaqI, and ApaI) were assessed using the polymerase chain reaction-restriction fragment length polymorphism method. RESULTS : There was a significant association of the VDR-FokI FF genotype with CRC cases (odds ratio, 2.9; P = .036) compared with the controls without polyps. The most common VDR-FokI genotype in the overall study population was the FF genotype (46%). However, upon breakdown by ethnicity, the FF genotype was the most common in African American participants (61%), and the Ff genotype was the most common in Hispanic/Latino participants (49%). When the association was assessed in a multivariate model, there was no significant association with any VDR polymorphism and CRC cases (P > .05). The other 3 polymorphic variants of VDR (BsmI, TaqI, and ApaI) were not associated with CRC. CONCLUSIONS : The results from this study suggest that genetic variation of the VDR-FokI SNPs may influence CRC risk, particularly in African American cohorts. Cancer 2014. © 2014 American Cancer Society.