Bin Zhang1, Ying Li2, Daorong Hou3, Quan Shi1, Shuo Yang1, Qihong Li4. 1. Department of Stomatology ,Chinese PLA General Hospital, Beijing, China. 2. Department of Stomatology, General Hospital of the Air Force of Chinese PLA, Beijing, China. 3. Animal Core Facility of Nanjing Medical University, Nanjing, China. 4. Department of Stomatology, Affiliated Hospital of Academy Military Medical Science, Beijing, China.
Abstract
BACKGROUND: MicroRNAs (miRNAs) have emerged as key players in various human biological processes, including tumorigenesis. Here, we investigated the roles of miR-375 in the pathogenesis of oral squamous cell carcinoma (OSCC). METHODS: We performed quantitative real-time PCR (qRT-PCR) to detect miR-375 expression in OSCC tissues and corresponding normal oral epithelial tissues and analyze the correlation of miR-375 expression with OSCC metastasis and patient's survival. Then, the effects of miR-375 expression on proliferation, cell cycle, apoptosis and radiosensitivity in OSCC cells were determined by using MTT, flow cytometry and clonogenic survival assays. A dual-luciferase reporter assay was performed to test whether miR-375 binds to the 3'-untranslated region (3'-UTR) of target mRNA. RESULTS: The expression level of miR-375 in OSCC tissues was significantly lower than that in normal oral epithelial tissues, and low miR-375 expression was correlated with higher incidence of lymph node metastasis and poor survival of OSCC patients. Upregulation of miR-375 significantly inhibits growth, induces cell cycle arrest in G0/G1 phase, increases apoptosis and enhances radiosensitivity in OSCC cells. Analysis of luciferase activity demonstrated that miR-375 binds to the 3'-UTR of insulin like growth factor 1 receptor (IGF-1R). Small interfering RNA (shRNA)-mediated IGF-1R knockdown mimics the effects of miR-375 upregulation, while overexpression of IGF-1R partially reverses those effects in OSCC cells. CONCLUSION: It was obviously demonstrated that miRNA-375 inhibits growth and enhances radiosensitivity in OSCC cells by targeting IGF-1R, suggesting that miR-375 may be a potential therapeutic target for OSCC patients.
BACKGROUND: MicroRNAs (miRNAs) have emerged as key players in various human biological processes, including tumorigenesis. Here, we investigated the roles of miR-375 in the pathogenesis of oral squamous cell carcinoma (OSCC). METHODS: We performed quantitative real-time PCR (qRT-PCR) to detect miR-375 expression in OSCC tissues and corresponding normal oral epithelial tissues and analyze the correlation of miR-375 expression with OSCC metastasis and patient's survival. Then, the effects of miR-375 expression on proliferation, cell cycle, apoptosis and radiosensitivity in OSCC cells were determined by using MTT, flow cytometry and clonogenic survival assays. A dual-luciferase reporter assay was performed to test whether miR-375 binds to the 3'-untranslated region (3'-UTR) of target mRNA. RESULTS: The expression level of miR-375 in OSCC tissues was significantly lower than that in normal oral epithelial tissues, and low miR-375 expression was correlated with higher incidence of lymph node metastasis and poor survival of OSCC patients. Upregulation of miR-375 significantly inhibits growth, induces cell cycle arrest in G0/G1 phase, increases apoptosis and enhances radiosensitivity in OSCC cells. Analysis of luciferase activity demonstrated that miR-375 binds to the 3'-UTR of insulin like growth factor 1 receptor (IGF-1R). Small interfering RNA (shRNA)-mediated IGF-1R knockdown mimics the effects of miR-375 upregulation, while overexpression of IGF-1R partially reverses those effects in OSCC cells. CONCLUSION: It was obviously demonstrated that miRNA-375 inhibits growth and enhances radiosensitivity in OSCC cells by targeting IGF-1R, suggesting that miR-375 may be a potential therapeutic target for OSCC patients.
Authors: Kelly Yi Ping Liu; Sarah Yuqi Zhu; Denise Brooks; Reanne Bowlby; J Scott Durham; Yussanne Ma; Richard A Moore; Andrew J Mungall; Steven Jones; Catherine F Poh Journal: Oncotarget Date: 2020-06-09