Polyphenon E Effects on Gene Expression in PC-3 Prostate Cancer Cells

Abstract

Polyphenon E (Poly E) is a standardized, caffeine-free green tea extract with defined polyphenol content. Poly E is reported to confer chemoprotective activity against prostate cancer (PCa) progression in the TRAMP model of human PCa, and has shown limited activity against human PCa in human trials. The molecular mechanisms of the observed Poly E chemopreventive activity against PCa are not fully understood. We hypothesized that Poly E treatment of PCa cells induces gene expression changes, which could underpin the molecular mechanisms of the limited Poly E chemoprevention activity against PCa. PC-3 cells were cultured in complete growth media supplemented with varied Poly E concentrations for 24 h, then RNA was isolated for comparative DNA microarray (0 vs. 200 mg/L Poly E) and subsequent TaqMan qRT-PCR analyses. Microarray data for 54,613 genes were filtered for >2-fold expression level changes, with 8319 genes increased and 6176 genes decreased. Eight genes involved in key signaling or regulatory pathways were selected for qRT-PCR. Two genes increased expression significantly, MXD1 (13.98-fold; p = 0.0003) and RGS4 (21.98-fold; p = 0.0011), by qRT-PCR. MXD1 and RGS4 significantly increased gene expression in Poly E-treated PC-3 cells, and the MXD1 gene expression increases were Poly E dose-dependent.

Advances in Molecular Regulation of Prostate Cancer Cells by Top Natural Products of Malaysia

“…However, the active compounds of prostate chemo-preventative effects are not yet known. The presence of saccharide fatty acid esters [276,277], asperulosidic acid [277], and the anthraquinone damnacanthal [278] in the fruits, as well as the rich content of epicatechin and escopoletin in the leaves (Figure 6), may contribute to the cytotoxic effects of its extracts in several types of cancer cells including PC3 [279][280][281][282][283]. A recent review of 51 clinical and preclinical studies showed promising antitumor, antiproliferative, pro-apoptotic, antiangiogenesis, antimigratory, anti-inflammatory, and immunomodulatory activities [275].…”

“…However, more studies must be performed to establish if this natural product can be translated into any anticancer intervention. may contribute to the cytotoxic effects of its extracts in several types of cancer cells including PC3 [279][280][281][282][283]. A recent review of 51 clinical and preclinical studies showed promising antitumor, antiproliferative, pro-apoptotic, antiangiogenesis, antimigratory, anti-inflammatory, and immunomodulatory activities [275].…”