Jun Cheng1, Li-Ming Wu2, Xue-Song Deng1, Jian Wu2, Zhen Lv2, Hang-Fen Zhao1, Zhang Yang3, Yong Ni4. 1. Department of Hepatobiliary and Pancreatic Surgery, the First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, Shenzhen 518035, China. 2. Department of Hepatobiliary and Pancreatic Surgery, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China; Key Laboratory of Combined Multi-organ Transplantation, Ministry of Public Health, Hangzhou 310003, China. 3. Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China; School of Life Science, Fudan University, Shanghai 200433, China. 4. Department of Hepatobiliary and Pancreatic Surgery, the First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, Shenzhen 518035, China. Electronic address: szniyong@sina.com.
Abstract
BACKGROUND: Accumulating evidence demonstrates that microRNAs (miRNAs) play essential roles in tumorigenesis and cancer progression of hepatocellular carcinoma (HCC). Average targets of a miRNA were more than 100. And one miRNA may act in tumor via regulating several targets. The present study aimed to explore more potential targets of miR-449a by proteomics technology and further uncover the role of miR-449a in HCC tumorigenesis. METHODS: Technologies such as iTRAQ-based quantitative proteomic were used to investigate the effect of miR-449a on HCC. The expression of c-Met and miR-449a was detected by qRT-PCR in HCC samples. Gain- and loss-of-function experiments were performed to identify the function and potential target of miR-449a in HCC cells. RESULTS: In HCC, miR-449a was significantly downregulated, while c-Met was upregulated concurrently. Quantitative proteomics and luciferase reporter assay identified c-Met as a direct target of miR-449a. Moreover, miR-449a inhibited HCC growth not only by targeting CDK6 but also by suppressing c-Met/Ras/Raf/ERK signaling pathway. Furthermore, the inhibition of c-Met expression with a specific siRNA significantly inhibited cells growth and deregulated the ERK pathway in HCC. CONCLUSION: The tumor suppressor miR-449a suppresses HCC tumorigenesis by repressing the c-Met/ERK pathway.
BACKGROUND: Accumulating evidence demonstrates that microRNAs (miRNAs) play essential roles in tumorigenesis and cancer progression of hepatocellular carcinoma (HCC). Average targets of a miRNA were more than 100. And one miRNA may act in tumor via regulating several targets. The present study aimed to explore more potential targets of miR-449a by proteomics technology and further uncover the role of miR-449a in HCC tumorigenesis. METHODS: Technologies such as iTRAQ-based quantitative proteomic were used to investigate the effect of miR-449a on HCC. The expression of c-Met and miR-449a was detected by qRT-PCR in HCC samples. Gain- and loss-of-function experiments were performed to identify the function and potential target of miR-449a in HCC cells. RESULTS: In HCC, miR-449a was significantly downregulated, while c-Met was upregulated concurrently. Quantitative proteomics and luciferase reporter assay identified c-Met as a direct target of miR-449a. Moreover, miR-449a inhibited HCC growth not only by targeting CDK6 but also by suppressing c-Met/Ras/Raf/ERK signaling pathway. Furthermore, the inhibition of c-Met expression with a specific siRNA significantly inhibited cells growth and deregulated the ERK pathway in HCC. CONCLUSION: The tumor suppressor miR-449a suppresses HCC tumorigenesis by repressing the c-Met/ERK pathway.