Vitamin D receptor gene polymorphisms, insulin-like growth factors, and prostate cancer risk: a population-based case-control study in China.
Operating through the vitamin D receptor (VDR), vitamin D inhibits prostate cancer growth and increases insulin-like growth factor binding protein (IGFBP) expression, suggesting that the vitamin D and insulin-like growth factor (IGF) regulatory systems may operate together to affect prostate cancer. Among 191 newly diagnosed prostate cancer cases and 304 randomly selected population controls in Shanghai, China, we found no significant association between the BsmI or FokI VDR gene polymorphisms and prostate cancer risk. However, we found that among men with the ff FokI genotype, those in the highest tertile of plasma IGFBP-3 had a decreased risk versus those in the lowest tertile (odds ratio, 0.14; 95% confidence interval, 0.04-0.56; P(trend) < 0.01), whereas among men with the FF and Ff genotypes, IGFBP-3 was not associated with risk. Similarly, IGFBP-1 was inversely associated with prostate cancer risk only among men with the ff FokI genotype (odds ratio, 0.25; 95% confidence interval, 0.07-0.85; P(trend) = 0.02). No such FokI genotype-specific effects were observed for IGF-I or IGF-II. Our findings in a low-risk population suggest that the IGF and vitamin D regulatory systems may interact to affect prostate cancer risk. Larger studies are needed to confirm these findings and clarify the underlying mechanisms.
Chokkalingam
A P
AP
Department of Epidemiology and Preventive Medicine, University of Maryland, Baltimore, MD 21201, USA. chokkala@mail.nih.gov
McGlynn
K A
KA
Gao
Y T
YT
Pollak
M
M
Deng
J
J
Sesterhenn
I A
IA
Mostofi
F K
FK
Fraumeni
J F
JF
Hsing
A W
AW
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D016022:Case-Control Studies; D002681:China / Q000453:epidemiology; D015252:Deoxyribonucleases, Type II Site-Specific; D005838:Genotype; D006801:Humans; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000097:blood*; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D007335:Insulin-Like Growth Factor II / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D011471:Prostatic Neoplasms / Q000097:blood* / Q000453:epidemiology / Q000235:genetics*; D018167:Receptors, Calcitriol / Q000235:genetics*; D012307:Risk Factors
D018970:Insulin-Like Growth Factor Binding Protein 1; D018972:Insulin-Like Growth Factor Binding Protein 3; D018167:Receptors, Calcitriol; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; C053864:endodeoxyribonuclease BsmI; C035042:endodeoxyribonuclease FokI; D015252:Deoxyribonucleases, Type II Site-Specific