A ROS/STAT3/HIF-1[alpha] signaling cascade mediates EGF-induced TWIST1 expression and prostate cancer cell invasion

• Published in: The Prostate 2014-05, Vol.74 (5), p.528
• Main Authors: Cho, Kyung Hwa, Choi, Moon Jung, Jeong, Kang Jin, Kim, Jeong Jin, Hwang, Min Ha, Shin, Shang Cheul, Park, Chang Gyo, Lee, Hoi Young
• Format: Article
• Language: English
• ISSN: 0270-4137; 1097-0045
• DOI: 10.1002/pros.22776

BACKGROUND 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)-1[alpha] 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-1[alpha] expression and morphological change of prostate cancer epithelial cells to mesenchymal cells. Silencing HIF-1[alpha] expression dramatically reduced EGF-induced TWIST1 expression and prostate cancer cell EMT. Conversely, transfection of the cells with HIF-1[alpha] 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-1[alpha] 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-1[alpha]/TWIST1/N-cadherin signaling cascade, providing novel biomarkers and promising therapeutic targets for prostate cancer cell progression. Prostate 74:528-536, 2014. © 2014 Wiley Periodicals, Inc. [PUBLICATION ABSTRACT]