MicroRNA‐143/Musashi‐2/KRAS cascade contributes positively to carcinogenesis in human bladder cancer

• DOI: 10.1111/cas.14035
• Publication Date: 2019-05-08T03:58:25Z
• Authors: Takuya Tsujino; Nobuhiko Sugito; Kohei Taniguchi; Ryo Honda; Kazumasa Komura; Yuki Yoshikawa; Tomoaki Takai; Koichiro Minami; Yuki Kuranaga; Haruka Shinohara; Yoshihisa Tokumaru; Kazuki Heishima; Teruo Inamoto; Haruhito Azuma; Yukihiro Akao
• Keywords: 0301 basic medicine; 0303 health sciences; Down-Regulation; RNA-Binding Proteins; Original Articles; Up-Regulation; 3. Good health; Gene Expression Regulation, Neoplastic; Proto-Oncogene Proteins p21(ras); Mice; MicroRNAs; 03 medical and health sciences; Urinary Bladder Neoplasms; Cell Line, Tumor; Animals; Humans; Neoplasm Transplantation; Cell Proliferation

AbstractIt has been well established that microRNA (miR)‐143 is downregulated in human bladder cancer (BC). Recent precision medicine has shown that mutations in BC are frequently observed in FGFR3, RAS and PIK3CA genes, all of which correlate with RAS signaling networks. We have previously shown that miR‐143 suppresses cell growth by inhibiting RAS signaling networks in several cancers including BC. In the present study, we showed that synthetic miR‐143 negatively regulated the RNA‐binding protein Musashi‐2 (MSI2) in BC cell lines. MSI2 is an RNA‐binding protein that regulates the stability of certain mRNAs and their translation by binding to the target sequences of the mRNAs. Of note, the present study clarified that MSI2 positively regulated KRAS expression through directly binding to the target sequence of KRAS mRNA and promoting its translation, thus contributing to the maintenance of KRAS expression. Thus, miR‐143 silenced KRAS and MSI2, which further downregulated KRAS expression through perturbation of the MSI2/KRAS cascade.