6c116e57-9a3c-4832-9595-2064f69c3e1c
title
A functional C-G polymorphism in the  CYP7B1  promoter region and its different distribution in Orientals and Caucasians.
00fe5f1d-fa42-4fae-af11-77f847421698
abstract
Cytochrome P450 (CYP) 7B1  is involved in many metabolic processes including androgen metabolism. Genetic variation in the  CYP7B1  gene may play a role in predisposition to prostate cancer. Here, we screened the human  CYP7B1  gene for possible polymorphisms. Only one single polymorphism was detected, a  C-G change in the promoter -104 base pair  from the transcription start site. The allele frequency was investigated in Swedish men and compared to a Korean population, as it is known that the frequency of prostate cancer is low among Orientals. We found that the frequency of the G-allele was 4.04% in Swedes (n=150) but only 0.33% among Koreans (n=153). Computer analysis indicated that the two variants bind with different affinities to a CCAAT-box binding protein. Expression studies with reporter constructs showed significantly higher transcriptional activity of the G variant in Hek293 cells (2.7-fold, P<0.05). In conclusion, we report here for the first time the detection of a single polymorphism in the  CYP7B1  gene. This polymorphism is associated with phenotypic differences in an expression system and a widely different allele frequency in two ethnic populations, with great differences in the incidence of prostate cancer.