Methylation-specific polymerase chain reaction (MSP) targeting promoter hypermethylation of the glutathione S transferase P1 gene (GSTP1), as the most frequent DNA alteration in prostatic carcinoma, was used for the molecular detection of cell-bound and cell-free prostate tumor DNA in various human bodily fluids.
Independent investigators have previously identified differential expression of two of these three genes, hepsin and beta-microseminoprotein, in prostate cancer.
Subsequent analysis of normal and cancerous human prostates demonstrated that the genes microseminoprotein-beta (MSMB) and transglutaminase 4 (TGM4) were expressed in distinct groups of ducts in the normal human prostate, and only MSMB was detected in areas of prostate cancer.
Previous studies have suggested a potential biomedical utility of PSP94 in applications such as diagnosis/prognosis and in treatment of human prostate cancer (PCa).
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.
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.
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.
rs10993994 in MSMB promoter affects serum MSMB expression, contributes to the genetic predisposition to prostate cancer in southern Chinese Han population.
A plausible functional basis for a few loci, such as FGFR2 for breast cancer and MSMB for prostate cancer, has been elucidated, but the majority are not understood and suggest new mechanisms of carcinogenesis.
Our results indicate that the amount or nature of mRNA transcripts expressed from the LMTK2, HNF1B and MSMB candidate genes is altered in prostate cancer, and provides further evidence for a role for these genes in this disorder.
Interestingly, PSP94 expression is reduced or lost in the majority of the prostate tumours, whereas CRISP-3 expression is upregulated in prostate cancer compared with normal prostate tissue.