Knockdown of Coronin-1C disrupts Rac1 activation and impairs tumorigenic potential in hepatocellular carcinoma cells

Coronin-1C is an important F-actin binding protein which is critical forcell motility. Furthermore, the expression of this protein was found to be increasedin diffuse tumors and was correlated with the degree of tumor malignancy. However,the mechanism(s) through which this protein enhances malignancy in hepatocellularcarcinoma (HCC) is poorly understood. In this study, we found that Coronin-1Cwas overexpressed in human HCC tissues compared with the adjacent non-tumor tissues.Overexpression of Coronin-1C enhanced the cell migration in the human HCC cellline BEL-7402, whereas suppressed cell migration and proliferation were observedin Coronin-1C-knockdown BEL-7402 cells together with impaired cell polarity, disruptedcytoskeleton and decreased Rac-1 activation. Moreover, the Coronin-1C knockdowncells displayed a lower degree of malignancy by inducing smaller tumors in nudemice. Thus, we demonstrated a relationship between Coronin-1C overexpression andhuman HCC growth through enhancement of tumor cell proliferation and migration,which are correlated with Rac-1 activation.