摘要：Background Hormonal alterations during development have lifelong effects on the prostate gland. Endogenous estrogens, including 17β-estradiol (E2), and synthetic estrogenic endocrine disruptors, such as bisphenol A (BPA), have similar effects on prostate development. Increasing exposure to estrogens within the low-dose, physiologic range results in permanent increases in the size and androgen responsiveness of the prostate, whereas exposure within the high-dose, pharmacologic range has the opposite effects. Objectives We tested the hypothesis that the low-dose effects of estrogens on the developing prostate are associated with increased expression of androgen receptor ( Ar ) and estrogen receptor 1 (α) ( Esr1 ) genes in mesenchyme cells. Methods Ar and Esr1 mRNA levels were quantified in primary cultures of fetal mouse prostate mesenchyme cells treated with E2 and BPA. Discussion Ar and Esr1 mRNA expression increased in response to E2, with thresholds of 0.001 and 0.037 nM, respectively; and in response to BPA, with a threshold of 1 nM for both mRNAs. We did not observe the expected inhibition of Ar mRNA expression by pharmacologic levels of E2 relative to unexposed cells. Conclusions The observed induction of gene expression occurred at concentrations within the range of free E2 previously shown to permanently increase prostate size, thus supporting the involvement of direct effects of estrogens on gene expression in prostate mesenchyme. The effects of BPA occurred within the range of concentrations currently measured in human serum, demonstrating the vulnerability of developing tissues to xenoestrogens.
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