R-spondin2 Suppresses the Progression of Hepatocellular Carcinoma via MAPK Signaling Pathway

The R-spondin family plays important roles in embryonic development, including in humans. However, information on the relationship between R-spondin2 and hepatocellular carcinoma (HCC) is lacking. This study aimed was to explore the mechanisms of R-spondin2 action in the progression of HCC. By analyzing R-spondin2 expression levels in HCC tissues by IHC and database, we identified that HCC tissues had lower expression levels of R-spondin2, correlated with a poor prognosis. We also established R-spondin2-overexpressing and knockdown cell lines and measured their viabilities and invasion abilities in vitro and their oncogenic capacity in vivo. Human mRNA microarray analysis was performed to screen for mRNAs that were differentially expressed between R-spondin2-overexpressing and control HCC cells. Microarray and Western blot analyses showed significant changes in the MAPK signaling pathway after transfection. Furthermore, in vivo experiments indicated that R-spondin2 knockdown increased the tumorigenicity of HCC cells after subcutaneous implantation in mice. Altogether, our results indicate that the R-spondin2, which might be a novel tumor suppressor gene, were responsible for inhibiting the proliferation and invasion of HCC via the MAPK signaling pathway. IMPLICATIONS: R-spondin2 gene might be a novel tumor suppressor gene providing new clues to clarify the biological behavior of HCC and thus reduce patient mortality and prolong survival.