ABSTRACT
Objective To investigate the effect and mechanism of RNAi-mediated STAT3 gene silencing on epithelial-to-mesenchymal transition (EMT) of human pancreatic cancer cells.Methods Lentivirus vector mediating RNA interference targeting STAT3 was constructed in SW1990 cell line.The invasion ability of SW1990 cells was determined by cell invasion assay in vitro.Cell proliferation and cell cycle of SW1990 cells were also detected.The expression of EMT related genes such as STAT3,P-STAT3,Twist,Snail and E-cadherin were analyzed by reverse transcription-PCR,real-time PCR,and Western blotting.Results Silencing of STAT3 with RNAi not only markedly reduced proliferation but also greatly decreased the invasion ability of SW1990 cells.The mRNA level and protein expression of Snail decreased significantly (P ＜ 0.05),but those of E-cadherin increased significantly (P ＜ 0.05),compared to parental cells.However,no difference was on the expression of Twist in SW1990 cell line.Conclusions STAT3 signaling pathway plays an important role in the process of EMT.Silencing of STAT3 with RNAi can significantly inhibit EMT by downregulating expression of Snail and E-cadherin in pancreatic cancer cells.
ABSTRACT
Objective To explore the expression and clinical relevance of metastasis-associated colon cancer-1 (MACC1) and C-MET proteins in hepatocellular carcinoma (HCC) tissue.Methods The expressions of MACC1 and C-MET were detected in 51 specimens of HCC and paraneoplastic liver tissue,normal liver tissue in 13 healthy cases using immunohistochemistry and Western blotting.The correlations of the expressions of MACC1 and C-MET proteins were evaluated,survival rates were observed,the relationship between the expression of MACC1,C-MET proteins and the clinicopathologic features of HCC were analyzed.Results The positive rate of MACC1 and C-MET proteins was 80.4％ and 76.5％ in HCC tissue,the relative expressions were 0.645 ± 0.047 and 0.504 ± 0.023 respectively,which was significantly different from those in paraneoplastic liver tissue and normal liver tissue (respectively F =173.308,252.817,all P =0.000).The survival analysis showed that the three-year survival rate in patients with positive MACC1 and C-MET expressions was significantly lower than that in patients with negative expressions (respectively x2 =3.934,4.439,all P ＜ 0.05),the positive rate and relative expressions of MACC1 and C-MET were significantly correlated with TNM stage,portal vein cancer thrombus and pathology typing (P ＜ 0.05).Conclusions The expression of MACC1 and C-MET is associated with the malignant progression of HCC.MACC1 may serve as a independent prognostic factor for advanced HCC and a possible therapy target for the treatment of HCC.