Of note, rs7000448 is in strong linkage disequilibrium with rs10761581 in NCOA4, a SNP that has been implicated to be independently associated, with respect to the widely reported SNP rs10993994 in the nearby gene MSMB, with prostate cancer in men of European descent.
Recent functional work has shown that different alleles of the significantly associated SNP in the promoter of MSMB found to be associated with prostate cancer risk, rs10993994, can influence its expression in tumors and in vitro studies.
We conclude that MSMB is unlikely to be a familial PrCa gene and propose that the high-risk alleles of the SNPs in the 5'UTR effect PrCa risk by modifying MSMB gene expression in response to hormones in a tissue-specific manner.
We examined the association between rs10993994 genotype and MSP levels in a sample of 500 prostate cancer-free men from four racial/ethnic populations in the Multiethnic Cohort (European Americans, African Americans, Latinos, and Japanese Americans).
Loci on chromosome 10 include MSMB, which encodes beta-microseminoprotein, a primary constituent of semen and a proposed prostate cancer biomarker, and CTBP2, a gene with antiapoptotic activity; the locus on chromosome 7 is at JAZF1, a transcriptional repressor that is fused by chromosome translocation to SUZ12 in endometrial cancer.
These data indicate that the increase in PC risk associated with rs10993994:C>T is likely mediated by the variant's effect on PSP94 expression; however, this effect does not extend to NCOA4 in the data presented here.
SNPs in MSMB and 8q24 which predispose to prostate cancer overall are associated with risk for metastatic prostate cancer, the most lethal form of this disease.
Genome-wide significant associations were observed with 84 variants all located at the known PrCa risk regions at 8q24 (128.484-128.548) and 10q11.22 (MSMB gene).
For the two SNPs that had significant differences between more and less aggressive disease rs2735839 in KLK3 (P = 8.4 x 10(-7)) and rs10993994 in MSMB (P = 0.046), the alleles that are associated with increased risk for PCa were more frequent in patients with less aggressive disease.
A total of 31 proteins were associated with prostate cancer risk including proteins encoded by <i>GSTP1</i>, whose methylation level was shown previously to be associated with prostate cancer risk, and <i>MSMB, SPINT2, IGF2R</i>, and <i>CTSS</i>, which were previously implicated as potential target genes of prostate cancer risk variants identified in genome-wide association studies.
Variants in the promoter of the MSMB gene have been associated with the risk of prostate cancer (PCa) in several independent genome-wide association studies.
The observations that rs10993994 is the strongest associated variant in the region and its risk allele has a major effect on the transcriptional activity of MSMB, a gene with previously described prostate cancer suppressor function, together suggest the T allele of rs10993994 as a potential causal variant at 10q11 that confers increased risk of prostate cancer.
Additional copies of the prostate cancer risk allele resulted in lower beta-MSP but higher PSA levels, and singly explained 23% and 5% of the variation seen in semen beta-MSP and PSA, respectively.
rs10993994 in MSMB promoter affects serum MSMB expression, contributes to the genetic predisposition to prostate cancer in southern Chinese Han population.
Our data revealed that the T allele of MSMBrs10993994 polymorphism was significantly associated with PCa in all subjects (allele contrast: OR=1.24, 95% CI=1.19-1.29, p<0.001).