Penta-O-galloyl-β-D-glucose suppresses EGF-induced eIF3i expression through inhibition of the PI3K/AKT/mTOR pathway in prostate cancer cells.

Approximately 70% of prostate cancer patients will develop bone metastasis in axial and other regions of the skeleton. Epidermal growth factor (EGF) generated from bone tissue contributes to prostate cancer metastasis. In a previous study, penta-O-galloyl-β-D-glucose (PGG) suppressed androgen-independent prostate cancer bone metastasis by transcriptionally repressing EGF-induced MMP-9 expression. This study utilized proteomics to analyze the effects of PGG in EGF-induced prostate cancer bone metastasis. This study showed that PGG suppressed EGF-induced eIF3i expression in PC-3 cells. By transfection of eIF3i shRNA, it was observed that reduced eIF3i expression suppressed the invasion of PC-3 cells in vitro. PGG reduced EGF-induced eIF3i expression through inhibition of the PI3K/AKT/mTOR pathway. Therefore, PGG may be able to be used as a potential new therapeutic drug for prostate cancer bone metastasis.