CELLULAR EXPRESSION OF BETA-MICROSEMINOPROTEIN (BETA-MSP) MESSENGER-RNA AND ITS PROTEIN IN UNTREATED PROSTATE-CANCER

BACKGROUND. Previous studies have shown that beta-microseminoprotein ( beta-MSP) may be used as a diagnostic marker for prostate cancer. Howe ver, the level of expression of beta-MSP in prostate cancer detected b y immunohistochemistry (IHC) has varied from one study to another. MET HODS. We analyzed the expression of both beta-MSP mRNA and its protein in a large sample of prostate tumors from 104 patients with untreated prostate cancer, using both nonradioactive in situ hybridization (ISH ) and IHC. RESULTS. Our results showed that 72 and 96 of 104 specimens were negative for beta-MSP mRNA (69.2%) and beta-MSP (92.3%), respect ively. Furthermore, a reduced expression of both beta-MSP mRNA and its protein was detected in all malignant epithelial tissues compared wit h benign epithelia. Not all malignant tissue samples negative for beta -MSP mRNA were negative for beta-MSP (6.7%), and vice versa (29.8%). O ther tissue samples were either negative for both (62.5%) or positive for both (1.0%). CONCLUSIONS. Our results showed a lower level of expr ession of beta-MSP in prostate cancer tissue, compared with benign pro state tissue. This phenomenon may be mainly due to the presence of red uced levels of beta-MSP mRNA. (C) 1998 Wiley-Liss, Inc.