Androgen receptor induces EPHA3 expression by interacting with transcription factor SP1.

This study is aimed to investigate the association between EPHA3 expression and androgen receptor (AR) signaling and the potential mechanism. We determined mRNA and protein levels of EPHA3 and AR signaling‑related genes in the PCa cell line 22Rv1 by reverse transcription‑polymerase chain reaction (RT‑PCR) and western blotting, respectively. The EPHA3 mRNA and protein levels were both found to be elevated by dihydrotestosterone (DHT) hormone in a dose‑ and time‑dependent manner, as AR and prostate‑specific antigen (PSA) expression were increased. Similarly, EPHA3 protein levels were also increased in the PCa cell line LNCaP stimulated with DHT or mibolerone (Mib). Overexpression of pEGFP‑AR in 22Rv1 cells significantly increased the EphA3 level, while AR knockdown with small interfering RNA (siRNA) for AR (siAR) markedly decreased the expression of EPHA3. The key EPHA3 promoter region associated with AR regulation was evaluated by co‑transfection of various pGL3‑basic‑luciferase reporter plasmids, containing EPHA3 core promoter fragments differing in length, with the AR plasmid or siAR into 22Rv1 cells. AR overexpression in 22Rvl cells raised the EphA3 promoter transcription activity of pGL3‑EPHA3‑Luc (EPHA3‑Luc)‑789, and vice versa. Similarly, luciferase activity of EPHA3‑Luc‑317 was also clearly affected. However, truncated EPHA3‑Luc‑237 without the transcription factor specific protein 1 (SP1) binding sites or EPHA3‑Luc‑789ΔSP1 with ...
Source: Oncology Reports - Category: Cancer & Oncology Tags: Oncol Rep Source Type: research