The membrane-cytoskeleton organizer ezrin is necessary for hepatocellular carcinoma cell growth and invasiveness

Purpose The change of cell mobility is one of the preconditions of tumor metastasis. Cell skeleton alteration and rearrangement of F-actin was closely related to cell mobility. Ezrin is a membrane-cytoskeleton organizer that can mediate the rearrangement and the function of F-actin. In this paper, we investigated the effect of ezrin on hepatocellullar carcinoma cell growth and invasiveness. Methods Hepatocellular carcinoma cell lines such as MHCC-1, MHCC97-H, SF7721, SMMC7721, Hep3B, and HepG2 were chosen in this study. We first examined the expression and the distribution of ezrin and F-actin in these cell lines using immunofluorescence, RT–PCR, and the western blot. Next we used small interfering RNA (siRNA) to down-regulate ezrin expression in MHCC-1, MHCC97-H, SF7721, and HepG2 to investigate the role of ezrin in tumor cell growth and invasiveness. Results Our preliminary results showed that the expression of ezrin and γ-actin in MHCC-1, MHCC97-H, and SF7721 with higher metastatic potential were obviously up-regulated than those in SMMC7721, Hep3B, and HepG2 with lower potential. No different expression of β-actin was found in the above tumor cell lines. The outcome of RNAi indicated that decreasing ezrin expression can notably inhibit the proliferation of the four hepatocellular carcinoma cell lines ( p < 0.01, n = 10). The proportion of cells in G2-M phase also decreased after RNAi. The number of pseudopods decreased as well after RNAi treatment ( p < 0.01, n = 5). The mobility and invasiveness of cancer cells decreased with decreasing ezrin expression tested by transwell assay ( p < 0.01, n = 8). Conclusion Ezrin plays an important role in the process of hepatocellular carcinoma cell proliferation, migration, and invasiveness.