MicroRNAs (miRNAs) are short, conserved segments of non-coding RNA which play a significant role in prostate cancer development and progression. To identify miRNAs associated with castration resistance, we performed miRNA microarray analysis comparing castration resistant prostate cancer (CRPC) with androgen dependent prostate cancer (ADPC). We identified common underexpression of miR-4638-5p in CRPC compared to ADPC samples, which were further confirmed by quantitative PCR analysis. The role of miR-4638-5p in prostate cancer androgen-independent growth has been demonstrated both in vitro and in vivo. We also identified Kidins220 as a target gene directly regulated by miR-4638-5p and shRNA-mediated knockdown of Kidins220 phenocopied miR-4638-5p restoration. Subsequently, we revealed that Kidins220 activates PI3K/AKT pathway, which plays a key role in CRPC. Loss of miR- 4638-5p may lead to CRPC through the activity of Kidins220 and PI3K/AKT pathway. Furthermore, we found that miR-4638-5p, through regulating Kidins220 and the downstream activity of VEGF and PI3K/AKT pathway, influences prostate cancer progression via angiogenesis. The identification of miR-4638-5p down-regulation in CRPC and the understanding of the functional role of miR-4638-5p and its downstream genes/pathways have the potential to develop biomarkers for CRPC onset and to identify novel targets for novel forms of treatments of this lethal form of PCa.
Oncotarget. 2016 Jun 18 [Epub ahead of print]
Yang Wang, Ning Shao, Xueying Mao, Minmin Zhu, Weifei Fan, Zhixiang Shen, Rong Xiao, Chuncai Wang, Wenping Bao, Xinyu Xu, Chun Yang, Jian Dong, Deshui Yu, Yan Wu, Caixia Zhu, Liting Wen, Xiaojie Lu, Yong-Jie Lu, Ninghan Feng
Department of Urology, Affiliated Wuxi No. 2 Hospital of Nanjing Medical University, Wuxi, China., Department of Urology, Affiliated Wuxi No. 2 Hospital of Nanjing Medical University, Wuxi, China., Centre for Molecular Oncology, Barts Cancer Institute, Queen Mary University of London, London, United Kingdom., Department of Urology, Affiliated Wuxi No. 2 Hospital of Nanjing Medical University, Wuxi, China., Jiangsu Province Geriatric Institute, Nanjing, China., Jiangsu Province Geriatric Institute, Nanjing, China., College of Clinical Medicine, Nanjing Medical University, Nanjing, China., College of Clinical Medicine, Nanjing Medical University, Nanjing, China., College of Clinical Medicine, Nanjing Medical University, Nanjing, China., Department of Urology, Affiliated Wuxi No. 2 Hospital of Nanjing Medical University, Wuxi, China., Department of Urology, Affiliated Wuxi No. 2 Hospital of Nanjing Medical University, Wuxi, China., Department of Urology, Affiliated Wuxi No. 2 Hospital of Nanjing Medical University, Wuxi, China., Department of Urology, Affiliated Wuxi No. 2 Hospital of Nanjing Medical University, Wuxi, China., Department of Urology, Affiliated Wuxi No. 2 Hospital of Nanjing Medical University, Wuxi, China., Department of Urology, Affiliated Wuxi No. 2 Hospital of Nanjing Medical University, Wuxi, China., Department of Urology, Affiliated Wuxi No. 2 Hospital of Nanjing Medical University, Wuxi, China., Centre for Translational Medicine, Affiliated Wuxi No. 2 Hospital of Nanjing Medical University, Wuxi, China., Centre for Molecular Oncology, Barts Cancer Institute, Queen Mary University of London, London, United Kingdom., Department of Urology, Affiliated Wuxi No. 2 Hospital of Nanjing Medical University, Wuxi, China.