MicroRNA-449a suppresses hepatocellular carcinoma cell growth via G1 phase arrest and the HGF/MET c-Met 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 i TRAQ-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 q RT-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 cMet/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.