Background: Previous studies have shown that beta-microseminoprotein (beta-MSP) may be used as a diagnostic marker for prostate cancer. However, the level of expression of beta-MSP in prostate cancer detected by immunohistochemistry (IHC) has varied from one study to another.
Methods: 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%), respectively. Furthermore, a reduced expression of both beta-MSP mRNA and its protein was detected in all malignant epithelial tissues compared with benign epithelia. Not all malignant tissue samples negative for beta-MSP mRNA were negative for beta-MSP (6.7%), and vice versa (29.8%). Other tissue samples were either negative for both (62.5%) or positive for both (1.0%).
Conclusions: Our results showed a lower level of expression of beta-MSP in prostate cancer tissue, compared with benign prostate tissue. This phenomenon may be mainly due to the presence of reduced levels of beta-MSP mRNA.