Altered expression of genes identified in rats with prostatic chronic inflammation in a prostate spheroid model treated by estradiol/testosterone.

Rats are the standard model for male reproductive toxicity testing. Rat prostates are physiologically and anatomically different from those of humans. Drug and chemical toxicity testing would benefit from an in vitro model of human prostate cells. Recently, spheroids derived by three-dimensional culture of human cell lines have been used for assessing drug and chemical toxicity in vitro as they mimic in vivo environments more closely than two-dimensional culture. However, forming consistently sized, uniform spheroids is technically challenging for toxicity testing. The purpose of this study was to identify potential genetic markers for assessing prostatic toxicity in spheroids. We formed prostate spheroids using agarose-coated plates seeded with human primary prostate epithelial cells. Prostate spheroids were treated with either 17β-estradiol (E2) or testosterone (T) on days 2-7 of culture. Samples were harvested on culture day 7. qPCR was used to examine gene expression levels previously identified in rats with chronic inflammation exposed to estradiol benzoate, E2 and/or T. Changes in some gene expression levels were observed in the spheroids treated with E2 or T. We found that treatment with 1 nM E2 and/or 10 μM T significantly altered spheroid proliferation and viability, as well as the expression levels of genes including Nanog homeobox (NANOG), C-C motif chemokine ligand 2 (CCL2) and bone morphogenetic protein receptor type 2 (BMPR2). Further studies using biologically active molecules with prostatic toxicity are needed to verify the results and to determine whether gene expression changes in the spheroid are specific to E2 or T treatment.