BPA-induced prostatic hyperplasia in vitro is correlated to the unbalanced gene expression of AR and ER in the epithelium and stroma

Abstract

As a typical environmental endocrine disruptor (EED), bisphenol A (BPA) can induce pathological hyperplasia of the prostatic epithelium and stroma. This study concentrates mainly on the effect and underlying mechanisms of BPA on prostatic hyperplasia, which is based on the culture of primary human prostate epithelial cells (HPEpiC) and human prostate fibroblasts (HPrF). In an effect to screen the optimal pro-survival BPA levels, HPEpiC and HPrF were, respectively, exposed to concentration gradients of BPA (10⁻¹² M–10⁻⁴ M) solution diluted with two corresponding medium and incubated for 72 h at 37°C. CCK-8 assay showed that 10⁻⁹ M–10⁻⁵ M BPA could facilitate the proliferation of HPEpiC, while similar proliferative effect of HPrF only needed 10⁻¹¹ M–10⁻⁷ M BPA. HPrF were more sensitive to BPA than HPEpiC. The qualification of PCNA gene expression measured using quantitative real-time polymerase chain reaction (qRT-PCR) also mirrored the BPA-induced cell proliferation. Additionally, our results considered that androgen receptor (AR), estrogen receptor (ERα, ERβ), and NFKB1 gene expressions exhibited up-regulation in HPEpiC treated with 10⁻⁹ M BPA for 72 h. However, in HPrF, the identical BPA treatment could activate ERα, ERβ, and NFKB1 gene expressions and down-regulated the expression of AR levels. It is further confirmed that low-dose BPA can indeed promote the proliferation of human prostate cells in vitro, and the mechanisms of BPA for prostatic epithelial and stromal hyperplasia may not be consistent.