Activin B and Activin C Have Opposing Effects on Prostate Cancer Progression and Cell Growth

Current prognostic and diagnostic tests for prostate cancer are not able to accurately distinguish between aggressive and latent cancer. Members of the transforming growth factor-beta (TGFB) family are known to be important in regulating prostate cell growth and some have been shown to be dysregulated in prostate cancer. Therefore, the aims of this study were to examine expression of TGFB family members in primary prostate tumour tissue and the phenotypic effect of activins on prostate cell growth. Tissue cores of prostate adenocarcinoma and normal prostate were immuno-stained and protein expression was compared between samples with different Gleason grades. The effect of exogenous treatment with, or overexpression of, activins on prostate cell line growth and migration was examined. Activin B expression was increased in cores containing higher Gleason patterns and overexpression of activin B inhibited growth of PNT1A cells but increased growth and migration of the metastatic PC3 cells compared to empty vector controls. In contrast, activin C expression decreased in higher Gleason grades and overexpression increased growth of PNT1A cells and decreased growth of PC3 cells. In conclusion, increased activin B and decreased activin C expression is associated with increasing prostate tumor grade and therefore have potential as prognostic markers of aggressive prostate cancer.

Automated summary

Current tests for prostate cancer cannot accurately distinguish between aggressive and latent cancer. This study investigated the expression of TGFB family members in prostate tumor tissue and the effects of activins on prostate cell growth. The results showed that activin B expression increased in higher Gleason grades, and its overexpression inhibited growth of PNT1A cells but promoted growth and migration of PC3 cells. On the other hand, activin C expression decreased in higher Gleason grades and its overexpression had the opposite effects on cell growth. The findings suggest that activin B and activin C could potentially serve as prognostic markers for aggressive prostate cancer.