OBJECTIVERho, a ras homologous gene, encodes a group of GTP-binding proteins. Our previous study suggested that one member of the Rho gene family, RhoC, was related to the progression of human hepatocellular carcinoma (HCC). This study is to elucidate correlation of Rho overexpression with invasion and metastasis of HCC.

METHODSThe expression level of RhoC mRNA and protein in 25 cases of HCC and adjacent non-cancerous liver tissue was examined by RT-PCR and Western blot. Mutation of RhoC gene was examined by PCR-SSCP.

RESULTSThe expression of RhoC mRNA and protein was found in all HCC and adjacent non-cancerous liver tissue. The expression level of RhoC mRNA and protein was significantly higher in tumor tissue than in adjacent non-cancerous liver tissue (1.8 +/- 1.1 vs 1.0 +/- 0.7; 33 992 +/- 10 384 vs 17 342 +/- 9998, P < 0.01). The degree of RhoC overexpression was even more marked in metastatic lesions than in primary tumors (P < 0.01). Overexpression of the rhoC gene was significantly correlated with such clinic-pathological findings as cell differentiation, portal vein invasion, number of primary tumor nodules and metastatic lesions (P < 0.05). Mutation of RhoC gene was found in none of the HCC specimens examined.

CONCLUSIONOverexpression of RhoC gene may play an important role in carcinogenesis and progression of HCC.