Abstract
Epidermal growth factor (EGF) has been known to induce epithelial- mesenchymal transition (EMT) and prostate cancer cell progression. However, a detailed underlying mechanism by which EGF induces EMT and prostate cancer cell progression remained to be answered. Hypoxia-inducible factor (HIF)-1α and TWIST1 are transcription factors implicated in EMT and cancer metastasis. The purpose of this study is to determine the underlying mechanism of EGF-induced TWIST1 expression and prostate cancer invasion. METHODS siRNAs were used to silence genes. Immunoblotting, quantitative RT-PCR and immunofluorescence analysis were used to examine protein or mRNA expression. Modified Boyden chamber and invasion assay kit with Matrigel-coated inserts were used to determine prostate cancer cell migration and invasion, respectively. RESULTS We observed that EGF induced HIF-1α expression and morphological change of prostate cancer epithelial cells to mesenchymal cells. Silencing HIF-1α expression dramatically reduced EGF-induced TWIST1 expression and prostate cancer cell EMT. Conversely, transfection of the cells with HIF-1α siRNA reversed the reduced E-cadherin expression by EGF. Pretreatment of the cells with pharmacological inhibitors of reactive oxygen species [ROS, N-acetylcysteine (NAC)] and STAT3 (WP1066) but not p38 MAPK (SB203580) significantly reduced EGF-induced HIF-1α mRNA and protein expression. Further, pretreatment of the cells with NAC attenuated EGF-induced STAT3 phosphorylation. In addition, we showed that TWIST1 mediated EGF-induced N-cadherin expression, leading to prostate cancer invasion. CONCLUSIONS We demonstrate a mechanism by which EGF promotes prostate cancer cell progression through a ROS/STAT3/HIF-1α/TWIST1/N-cadherin signaling cascade, providing novel biomarkers and promising therapeutic targets for prostate cancer cell progression. Prostate 74:528-536, 2014.
Original language | English (US) |
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Pages (from-to) | 528-536 |
Number of pages | 9 |
Journal | Prostate |
Volume | 74 |
Issue number | 5 |
DOIs | |
State | Published - May 2014 |
Keywords
- HIF-1α
- STAT3
- TWIST1
- epidermal growth factor
- prostate cancer invasion
ASJC Scopus subject areas
- Oncology
- Urology