The Prostate-Associated Gene 4 (PAGE4) Could Play a Role in the Development of Benign Prostatic Hyperplasia under Oxidative Stress

Benign prostatic hyperplasia (BPH) is a common disease in elderly men with uncertain molecular mechanism, and oxidative stress (OS) has also been found associated with BPH development. Recently, we found that prostate-associated gene 4 (PAGE4) was one of the most significantly changed differentially expressed genes (DEGs) in BPH, which can protect cells against stress stimulation. However, the exact role of PAGE4 in BPH remains unclear. This study is aimed at exploring the effect of PAGE4 in BPH under OS. Human prostate tissues and cultured WPMY-1 and PrPF cells were utilized. The expression and localization of PAGE4 were determined with qRT-PCR, Western blotting, and immunofluorescence staining. OS cell models induced with H(2)O(2) were treated with PAGE4 silencing or PAGE4 overexpression or inhibitor (N-acetyl-L-cysteine (NAC)) of OS. The proliferation activity, apoptosis, OS markers, and MAPK signaling pathways were detected by CCK-8 assay, flow cytometry analysis, and Western blotting. PAGE4 was shown to be upregulated in human hyperplastic prostate and mainly located in the stroma. Acute OS induced with H(2)O(2) increased PAGE4 expression (which was prevented by OS inhibitor), apoptosis, cell cycle arrest, and reactive oxygen species (ROS) accumulation in WPMY-1 and PrPF cells. siPAGE4 plus H(2)O(2) potentiated H(2)O(2) effect via reducing the p-ERK1/2 level and increasing p-JNK1/2 level. Consistently, overexpression of PAGE4 offset the effect of H(2)O(2) and partially reversed the PAGE4 silencing effect. However, knocking down and overexpression of PAGE4 alone determined no significant effects. Our novel data demonstrated that augmented PAGE4 promotes cell survival by activating p-ERK1/2 and decreases cell apoptosis by inhibiting p-JNK1/2 under the OS, which could contribute to the development of BPH.