BACKGROUNDProstate stromal cells are known to regulate epithelial growth as well as support and maintain epithelial function. However, how stromal cells regulate epithelial cells and what differences among various histological/pathological prostate stromal cells in prostate cancer progression still remain unclear. This study aimed to investigate the different phenotypes of human various histological/pathological prostate stromal cells, and their role in tumor promotion.

METHODSThe different phenotypes of the human normal prostatic peripheral zonal primary stromal cells (NPPF), transitional zonal primary stromal cells (NPTF), and prostate cancer associated primary stromal cells (CAF) were examined with growth curves and Annexin V-fluorescein isothiocyanate (FITC) assay. The different effects on prostate cancer cell line C4-2B by NPPF, NPTF, and CAF were examined with MTT assay and Annexin V-FITC assay. The gene expression of different histological/pathological prostate stromal cells was profiled by microarray and hierarchical cluster analysis.

RESULTSThe growth rate of NPPF, NPTF and CAF gradually increased, followed by decreasing apoptosis. In vitro stromal-C4-2B cell line co-culture models, the proliferation and apoptosis of C4-2B cell line were differently affected by human various histological/pathological prostate stromal cells. CAF showed the most powerful effect to C4-2B cell line, as opposed to a weakest effect of NPTF. Microarray and hierarchical cluster analysis showed that the differentially expressed genes of CAF and NPPF were less than NPPF and NPTF, or CAF and NPTF. This was consistent with clinical observations that prostate cancer mostly derived from the peripheral zone and does not usually occur in the transitional zone.

CONCLUSIONNPPF, NPTF and CAF possess extremely different biological characteristics and gene expression, which may play an important role in genesis and development of prostate cancer.