Login to Access Video or Poster Abstract: MP17-08
Sources of Funding: 5K12DK100022_x000D_ U54DK104310_x000D_ R01DK093690

Introduction

Benign prostatic hyperplasia (BPH) is a disease that develops in aging men as the ratio of 17β-estradiol (E2) to testosterone (T) increases. Little is known about the role of estrogens and estrogen-regulated genes in BPH. Estrogens bind and activate estrogen receptors (ER), ERα and ERβ, to form homo- and heterodimers. These ERs play opposing roles within the prostate; ERα is pro-proliferative and ERβ is anti-proliferative. While ER activation and gene networks have been extensively studied in other organs, little is known in the prostate. The objective of this is study was to identify genes regulated by E2 and selective estrogen receptor modulators (SERMs).

Methods

RNA-seq was performed on BPH1 cells treated with E2 (binds ERα and ERβ), SERMs that bind ERβ (3β-diol, DPN, and WAY20070) and ERα (PPT) to identify genes specifically regulated by either ERα or ERβ. Sequences were mapped and assembled using TopHat, HTSeq, and edgeR. Genes reported were greater than 2-fold change over vehicle control with p-value < 0.05. CRISPR/Cas9 was used to knockout ERα and/or ERβ in BPH-1 cells to further validate ER-specific gene regulation as well as ER dimerization using Bioluminescence resonance energy transfer techniques.

Results

RNA-seq analysis of BPH1 cells treated with ER agonists revealed both overlapping and distinct gene expression profiles for each compound. By examining the overlap of genes induced or repressed by both the natural and synthetic compounds specific for each receptor, we have identified 144 ERα-specific, 222 ERβ-specific, and 42 ERα/ERβ-heterodimer genes. Luciferase assays in the CRISPR knockout cells confirm the receptor specificity of the synthetic compounds used in this study. Additionally, dimerization studies confirm the contribution of ERα and/or ERβ to the regulation of gene expression.

Conclusions

Using E2 and SERMs, we were able to identify and validate ERα- and ERβ-regulated genes in benign prostate cells. Further studies assessing these estrogen-regulated genes will provide a basis for biomarkers in the study of BPH/LUTD. Furthermore, given the opposing roles of ERα and ERβ, these genes will allow us to further assess the function of ER in disease promotion in patients and animal models as well as monitor the efficacy of therapeutic SERMs in the treatment of BPH/LUTS.

Funding

5K12DK100022_x000D_ U54DK104310_x000D_ R01DK093690