AIM: To investigate the expression of RhoC gene in hepatocellular carcinoma (HCC) and to evaluate the relationship between RhoC gene expression and invasion and metastasis of HCC. METHODS: mRNA expression level of RhoC gene was examined by reverse transcription-polymerase chain reaction (RT-PCR) in 25 cases of HCC and para-cancerous normal liver tissues. In addition, mutation of RhoC gene was examined by polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP). RESULTS: The mRNA expression levels of RhoC in tumor tissues were significantly higher than those in para-cancerous normal liver tissues (1.8

AIM: To investigate the expression of hypoxia-inducible factor (HIF)-2a/endothelial PAS domain protein 1 (EPAS1) in hepatocellular carcinoma (HCC). METHODS: Expression of HIF-2a/EPASl was investigated immunohistochemically on paraffin-embedded sections from 97 patients with HCC. To further confirm that HIF-2a/EPASl in HCC tissues also correlated with angiogenesis, a parallel immunohistchemistry study of vascular endothelial growth factor (VEGF) was performed on these 97 cases. RESULTS: HIF-2a/EPASl could be detected in 50 of 97 cases (51.6%), including 19 weakly positive (19.8%), and 31 strongly positive (31.1%), the other 47 cases were negative (48.4%). The expression of HIF-2a/EPASlwas significantly correlated with tumor size, capsule infiltration, portal vein invasion, and necrosis. A parallel immunohistochemical analysis of VEGF demonstrated its positive correlation with capsule infiltration, portal vein invasion, and HIF-2a/EPASl overexpression, which supported the correlation of HIF-2a/EPASlup-regulation with tumor angiogenesis. No apparent correlation was observed between HIF-2a/EPASl and capsular formation, presence of cirrhosis, and histological grade. CONCLUSION: HIF-2a/EPASl is expressed in most of HCC with capsular infiltration and portal vein invasion, which indicates a possible role of HIF-2a/EPASl in HCC metastasis.

AIM: To investigate the expression of cysteine-rich61 (Cyr61), connective tissue growth factor (CTGF) and nephroblastoma overexpressed gene (Nov) in hepatocellular carcinoma (HCC), and to evaluate the relationship between Cyr61, CTGF and Nov genes expression with invasion and metastasis of HCC. METHODS: Thirty-one HCC specimens were divided into small hepatocellular carcinoma (SHCC), nodular hepatocellular carcinoma (NHCC), solitary large hepatocellular carcinoma (SLHCC) according to their diameter and number of nodes. Reverse transcription polymerse chain reaction (RT-PCR) was used to detect the mRNA expression levels of Cyr61, CTGF and Nov genes in 31 resected specimens of hepatocellular carcinoma and para-cancerous normal liver tissues semi-quantitatively and the relation between their expression levels and clinical pathological parameters were compared. RESULTS: The expressions of Cyr61 and CTGF mRNA in carcinoma tissues were significantly higher than those in para-cancerous normal liver tissues (P<0.01). The expressions of Cyr61 and CTGF mRNA in HCC with venous invasion were higher than those in HCC without venous invasion. CTGF expression in HCC Edmondson's grade III-IV was significantly higher than that in HCC Edmondson's grade I-II (P=0.022). There was no obvious correlation between Nov mRNA and clinical-pathological features. Compared to NHCC, SLHCC had better cell differentiation, easier capsule formation, less microscopic venous invasion, milder liver cirrhosis. The expressions of Cyr61 and CTGF mRNA in NHCC were significantly higher than those in SLHCC and SHCC. CONCLUSION: Cyr61 and CTGF genes may play an important role in hepatocellular carcinogenesis and correlate with recurrence and metastasis of hepatocellular carcinoma. SLHCC has better biological behaviors than NHCC.

Hepatocellular carcinoma (HCC) is one of the most malignant human tumours because of its high incidence of metastasis. The mechanisms underlying the metastasis of HCC, however, remain poorly understood. In this study, we performed cDNA microarray analysis to profile gene expression patterns in two subtypes of HCC, solitary large HCC (SLHCC) and nodular HCC (NHCC), which differ significantly in the incidence of metastasis. Among 668 genes that were differentially expressed, we focused on RhoC, whose expression was significantly decreased in SLHCC compared to NHCC. The expression of RhoC in HCC and pericarcinomatous liver tissues (PCLT) was analysed at both the mRNA and protein levels by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting. In addition, immunohistochemistry was also performed on 94 cases of HCC with follow-up information. Collectively, our data indicate that the expression of RhoC significantly increased in HCC compared to PCLT; extrahepatic metastatic lesions expressed significantly higher levels of RhoC than the corresponding intrahepatic HCC tissues. There is a highly significant correlation of the RhoC expression levels with tumour vein invasion, number of tumour nodes and the status of differentiation. Significantly, the HCC patients with RhoC-positive expression had shorter survival than those with RhoC-negative expression. Together, our findings suggest a strong correlation between the expression of RhoC and HCC metastasis, implicating RhoC as a potential prognosis marker and therapeutic target for HCC.

AIM: To investigate the expression of metallothioneins (MTs), which were recently thought to have close relationship with tumors, in human hepatocellular carcinoma. METHODS: Histological specimens of 35 cases of primary human hepatocellular carcinoma with para-neoplastic liver tissue and 5 cases of normal liver were stained for MTs with monoclonal mouse anti-MTs serum (E9) by the immunohistochemical ABC technique. RESULTS: MTs were stained in the 35 cases of HCC, including 6 cases negative (17.1%), 23 weakly positive (65.7%), and 6 strongly positive(17.1%). But MTs were stained strongly positive in all the five cases of normal liver and 35 cases of para-neoplastic liver tissue. The differences of MTs expression between HCC and normal liver tissue or para-neoplastic liver tissue were highly significant (P<0.01). The rate of MTs expression in HCC grade I was 100 percent, higher than that in grade II(81%) and grade III and IV (78%). But the differences were not significant (P>0.05). No obvious correlations between MTs expression in HCC and tumor size, clinical stage or serum alpha fetoprotein concentration were found (P>0.05). CONCLUSION: Decrease of MTs expression in HCC may play a role in carcinogenesis of HCC. MTs are stained heterogenously in HCC. We can choose the anticancer agents according to the MTs concentration in HCC, which may improve the results of chemotherapy for HCC.