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

• Published in: The Prostate 2014-05, Vol.74 (5), p.528-536
• 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
• Subjects: Acetylcysteine - pharmacology; Cadherins - genetics; Cadherins - metabolism; Cell Line, Tumor; Cell Movement - drug effects; Cell Movement - physiology; Disease Progression; epidermal growth factor; Epidermal Growth Factor - pharmacology; Epithelial-Mesenchymal Transition; Gene Expression Regulation, Neoplastic; Gene Silencing; HIF-1α; Humans; Hypoxia-Inducible Factor 1, alpha Subunit - genetics; Hypoxia-Inducible Factor 1, alpha Subunit - metabolism; Male; Neoplasm Invasiveness - pathology; Nuclear Proteins - genetics; Nuclear Proteins - metabolism; Phosphorylation - drug effects; Phosphorylation - physiology; prostate cancer invasion; Prostatic Neoplasms - metabolism; Prostatic Neoplasms - pathology; Reactive Oxygen Species - metabolism; RNA, Small Interfering; Signal Transduction - drug effects; Signal Transduction - physiology; STAT3; STAT3 Transcription Factor - genetics; STAT3 Transcription Factor - metabolism; Twist-Related Protein 1 - genetics; Twist-Related Protein 1 - metabolism; TWIST1
• 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)‐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. © 2014 Wiley Periodicals, Inc.