Snail Protein Expression In Human Hepatocellula Carcinoma And Its Relationship With Invasion And Metastasis

Part I snail protein expression and clinical significance in hepatocellular carcinomaObjective:The expression of Snail protein in human hepatocellula carcinoma was investigated to explore the relationship of invasion, metastatic of human hepatocellula carcinoma and prognosis of patients with human hepatocellula carcinoma to Snail expression.Method:Specimens were taken froml50human hepatocellula carcinoma tissues and80normal liver tissues from Xiangya Hospital. These specimens were obtained from the patients who underwent hepatotomy from January2010to March2011. SP immunohistochemistry Was used to evaluate the expression of Snail in150human hepatocellula carcinoma tissues and80normal liver tissues.Results:The positive rates of Snail were significantly higher in human hepatocellula carcinoma tissues than in normal liver tisses(89.37%VS3.75%). Snail were positively correlated with the size of tumor(P<0.05), pTNM tumor stages (P<0.05), the differentiation degree oftumor(P<0.05), the portal vein cancer embolism(P<0.05)and the recurrence of tumor (P<0.05), but not with the patient’S age, the patient’S sex, the level of alpha-fetoprotein in serum before surgery, the patient’s Child—Pugh grade. Patients with positive expression of Snail had worse survival than those with negative one.Conclusion:Snail indirectly express the degree of malignancy of human hepatocellula carcinoma. It was a certain relationship with the occurrence, development and metastasis of human hepatocellula carcinoma. They can be used as evaluating indicators of the degree of malignancy of human hepatocellula carcinoma and the prognosis of patients with human hepatocellula carcinoma. Part II Inhibition of Snail expression by RNA interference repress epithelial-mesenchymal transition and invasion ability of human hepatocellula carcinoma cell HepG2in vitroObjective:To investigate the effect of RNA interference (RNAi) targeting transcription factor Snail on epithelial-mesenchymal transition (EMT) and invasion ability of human hepatocellula carcinoma cell HepG2in vitro.Methods RNA interference plasmid that can express small interfering RNA (siRNA) targeting Snail (Snail siRNA vector) or express siRNA that does notmatch any known human coding mRNA (control siRNA vector)was designed,constructed, and lipotransfected into HepG2cell line. HepG2-siSnail cells expressing Snail suppressed or HepG2-si-Control cells expressing Snail uninfluenced was selected by neomycin resistance. In HepG2-nontransfection, HepG2-siSnail and HepG2-siControl group HepG2cells, Snail, alpha-smooth muscle actin (α-SMA) and E-cadherin expression were examined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot, invasion ability was examined by Boyden chamber model.Results HepG2-nontransfection group:Both Snail anda-SMA expression were strong positive, but E-cadherin expression was poor positive. HepG2-siSnail group:Compared with that in HepG2-nontransfection group, Snail and α-SMA expression,and the numbers of HepG2cells permeating septum of Boyden chamber (NCS) were decreased, but E-cadherin expression increased significantly (P<0.01). HepG2-si Control group:Compared with that in HepG2-nontransfection group, Snail, a-SMA and E-cadherin expression, and NCS were similar.Conclusion:RNAi targeting Snail can inhibit EMT and invasion of HepG2cells efficiently in vitro. Snail might play a crucial role in EMT and invasion of hepatocellula carcinoma and suppression of Snail expression might be a promising strategy for the treatment of human hepatocellula carcinoma.