ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effect of RNAi-mediated STAT3 gene inhibition on metastasis of human pancreatic cancer cells and its underlying mechanism.</p><p><b>METHODS</b>STAT3 shRNA expression vector was constructed and transfected into SW1990 cells. STAT3 mRNA and STAT3 DNA-binding activity were examined using reverse transcription polymerase chain reaction (RT-PCR) and electrophoretic mobility shift assay (EMSA), respectively. The metastasis ability of SW1990 cells in vivo was determined in acute hematogenous metastasis model using nude mice. RT-PCR was performed to detect the mRNA expression of the MMP-2 and VEGF.</p><p><b>RESULTS</b>The mRNA expression of STAT3 and STAT3 DNA-binding activity were inhibited significantly by stable transfection of STAT3 shRNA expressing vectors. RNAi inhibition of STAT3 significantly suppressed the metastasis ability of SW1990 cells in vivo, and also markedly reduced the mRNA expression of MMP-2 and VEGF in SW1990 cells.</p><p><b>CONCLUSIONS</b>Inhibition of STAT3 by RNAi significantly inhibits the metastasis ability of pancreatic cancer cells through down-regulation of MMP-2 and VEGF, and may provide a novel strategy for preventing the metastasis of pancreatic cancer.</p>
Subject(s)
Animals , Humans , Mice , Cell Line, Tumor , Gene Expression Regulation, Neoplastic , Genetic Vectors , Matrix Metalloproteinase 2 , Genetics , Metabolism , Mice, Nude , Pancreatic Neoplasms , Genetics , Metabolism , Pathology , RNA Interference , RNA, Messenger , Genetics , STAT3 Transcription Factor , Genetics , Metabolism , Signal Transduction , Genetics , Transfection , Vascular Endothelial Growth Factor A , Genetics , Metabolism , Xenograft Model Antitumor AssaysABSTRACT
<p><b>OBJECTIVE</b>To investigate the effect and mechanism of blockade of STAT3 signaling pathway by JAK specific inhibitor-AG490 on invasion and metastasis of human highly metastatic pancreatic cancer line SW1990 in vitro.</p><p><b>METHODS</b>AG490 was added into the culture media for SW1990 cells. The invasion ability of SW1990 cells was determined by cell invasion assay kit. Western blot was performed to detect the protein expression of the STAT3, phosphorylated STAT3 (p-STAT3), MMP-2 and VEGF. RT-PCR was performed to detect the mRNA expression of the MMP-2 and VEGF.</p><p><b>RESULTS</b>20 micromol/L AG490 significantly inhibited the invasion ability of SW1990 cells and the inhibitory rate of invasion ability was (77.67 +/- 7.79) %. The use of AG490 not only markedly reduced the protein expression of p-STAT3, MMP-2 and VEGF, but also greatly reduced the mRNA expression of MMP-2 and VEGF.</p><p><b>CONCLUSION</b>Blocking STAT3 activation with AG490 can inhibit the invasion and metastasis ability of pancreatic cancer cells in vitro through down-regulation of MMP-2 and VEGF expression. Blocking STAT3 signaling pathway may provide a novel strategy in prevention of invasion and metastasis of pancreatic cancer.</p>
Subject(s)
Humans , Antineoplastic Agents , Pharmacology , Blotting, Western , Cell Line, Tumor , Dose-Response Relationship, Drug , Gene Expression Regulation, Neoplastic , Janus Kinases , Matrix Metalloproteinase 2 , Genetics , Metabolism , Neoplasm Invasiveness , Neoplasm Metastasis , Pancreatic Neoplasms , Genetics , Metabolism , Pathology , Phosphorylation , RNA, Messenger , Genetics , Reverse Transcriptase Polymerase Chain Reaction , STAT3 Transcription Factor , Metabolism , Signal Transduction , Tyrphostins , Pharmacology , Vascular Endothelial Growth Factor A , Genetics , MetabolismABSTRACT
Objective To investigate the correlation between the expression of STAT3 and MMP-2 in human pancreatic cancer,and to probe the mechanism by which STAT3 signal pathway regulates the expression of MMP-2 in pancreatic cancer cells.Methods Immunohistochemistry was used to detect the expression of STAT3,phosphorylated STAT3(p-STAT3)and MMP-2 in pancreatic cancer tissues of 34 cases and normal pancreatic tissues of 10 cases.Correlation between the expression of STAT3、p-STAT3 and MMP- 2 were statistically analyzed.Human pancreatic cancer cell lines SW1990 was cultured.AG490,an inhibitor of the upstream Janus kinase(JAK)of STAT3 was added into the culture medium.Electrophoretic mobility shift assay(EMSA)was used to detect STAT3 DNA-binding activity in SW1990 cells.Western blot was used to detect the expression of STAT3,p-STAT3 in SW1990 cells.In addition,the protein and mRNA expression of MMP-2 in SW1990 cells were determined by Western blot and RT-PCR,respectively. Results Immunohistochemistry revealed that the expression rate of STAT3,p-STAT3 were both higher in pancreatic cancer tissues than in normal pancreas tissues(P