Significance of Expression of PSP94 Isoforms in Etiology of Benign Prostatic Hyperplasia and Prostate Cancer.

Background: Prostate Secretory Protein of 94 Amino Acids (PSP94) level is known to increase in benign prostatic hyperplasia (BPH) and decrease in prostate cancer (PCa). However, there has not been a consensus on the abundance and significance of the different isoforms of PSP94 during the development of BPH and PCa. Methods: Benign and malignant prostate tissue was ascertained histologically. Biplex polymerase chain reaction (PCR) and real-time PCR were employed to quantitate the two isoforms, PSP94 (MSMB1) and PSP57 (MSMB2). Results: Higher abundance of both MSMB1 and MSMB2 transcripts was observed in BPH as compared to PCa. Further, there was a strong positive correlation between the transcript levels of these isoforms, MSMB1 and MSMB2, in samples from both BPH and PCa patients. Conclusions: PSP57 (MSMB2) transcript may not be involved in the development of BPH or PCa and could have a physiological role in prostate cells.

Effect of the human follicle-stimulating hormone-binding inhibitor and its N-terminal fragment on follicle-stimulating hormone-induced progesterone secretion by granulosa cells in vitro.

Intrafollicular factors play an important role in folliculogenesis. The follicle-stimulating hormone (FSH)-binding inhibitor (FSHBI), purified by our laboratory from human ovarian follicular fluid, has been shown to suppress ovulation and induce follicular atresia/apoptosis in mice as well as impair fertility in marmosets, the New World monkeys. The octapeptide, a peptide corresponding to the N-terminal region of human FSHBI (hFSHBI), has been synthesized and also shows FSHBI activity in vitro. In the present study, we have attempted to identify the mechanism of action of the peptide in granulosa cell cultures. Rat granulosa cell cultures were treated with varying concentrations of the octapeptide or partially purified hFSHBI (gel chromatography fraction hGF 2) in the presence or absence of human FSH (hFSH) and the amount of progesterone (P;4) secreted in the culture supernatants after 3 h/48 h was estimated. Both hGF2 and the octapeptide failed to alter basal levels as well as 8-bromo cAMP-induced P;4 production, while FSH-induced P 4 secretion was inhibited in a dose-dependent manner. These studies reveal that the octapeptide, a fragment of FSHBI, and the native protein have similar activity in vitro and both compounds alter FSH action at the receptor level upstream of cAMP formation.