Publications

Abstract

The biological function of inhibin-alpha subunit (INHalpha) in prostate cancer (PCa) is currently unclear. A recent study associated elevated levels of INHalpha in PCa patients with a higher risk of recurrence. This prompted us to use clinical specimens and functional studies to investigate the pro-tumourigenic and pro-metastatic function of INHalpha. We conducted a cross-sectional study to determine a link between INHalpha expression and a number of clinicopathological parameters including Gleason score, surgical margin, extracapsular spread, lymph node status and vascular endothelial growth factor receptor-3 expression, which are well-established prognostic factors of PCa. In addition, using two human PCa cell lines (LNCaP and PC3) representing androgen-dependent and -independent PCa respectively, we investigated the biological function of elevated levels of INHalpha in advanced cancer. Elevated expression of INHalpha in primary PCa tissues showed a higher risk of PCa patients being positive for clinicopathological parameters outlined above. Over-expressing INHalpha in LNCaP and PC3 cells demonstrated two different and cell-type-specific responses. INHalpha-positive LNCaP demonstrated reduced tumour growth whereas INHalpha-positive PC3 cells demonstrated increased tumour growth and metastasis through the process of lymphangiogenesis. This study is the first to demonstrate a pro-tumourigenic and pro-metastatic function for INHalpha associated with androgen-independent stage of metastatic prostate disease. Our results also suggest that INHalpha expression in the primary prostate tumour can be used as a predictive factor for prognosis of PCa.