Vitamin D Receptor Gene Bsm1 Polymorphism Positively Correlates with Prostate Cancer

 

The biologically active 1,25-dihydroxycholecalciferol has been shown to regulate the growth and differentiation of the normal prostate gland. This hormone exerts antiproliferative and oncostatic effects on prostatic cells through the vitamin D receptor, a member of the steroid/retinoid receptor superfamily of nuclear receptors that possesses tumor-suppressive functions. In a case control study, the authors evaluated the allelic frequencies and examined whether the Bsm1 vitamin D receptor (VDR) gene polymorphism could influence the development of benign prostate hyperplasia (BPH) and prostate cancer among Filipino patients through Restriction Fragment Length Polymorphism (RFLP). The predominant genotypes showed the absence of the Bsm1 restriction site in both the BPH group (BB, 28%; Bb, 44%) and the control group (BB, 44.4%; Bb, 50%). In contrast, majority of the prostate cancer cases had the bb genotype (70%) indicating the presence of the Bsm1 restriction site, and only 28% with Bb genotype. Furthermore, homozygosity (bb) for the presence of the Bsm1 restriction site positively correlated with the development of prostate cancer (p=0.0014, Odds Ratio=38.9) but not with benign prostate hyperplasia (p=0.06). These results indicate that the molecular variants of the VDR gene play a significant role in the development of prostate cancer among Filipinos and can be employed to identify high-risk individuals.

 

Keywords - benign prostatic hyperplasia, prostate cancer, polymorphism