沉默STAT3基因对胰腺癌细胞上皮间质转换的影响

Effect of STAT3 gene silencing on epithelial-to-mesenchymal transition of human pancreatic cancer cells

目的探讨沉默信号传导与转录激活基因3（STAT3）对人胰腺癌细胞系SW1990上皮问质转换的影响及机制。方法应用RNA干扰技术，建立STAT3基因稳定沉默的胰腺癌细胞系SW1990。MTF法检测细胞的增殖情况，流式细胞仪检测细胞周期。体外细胞侵袭实验观察侵袭能力的改变。实时PCR、蛋白印迹方法检测STAT3、P—STAT3、TWIST、Snail和E—cadherin基因的mRNA、蛋白含量。结果STAT3基因沉默后，细胞增殖水平下降（P〈0．05），细胞侵袭能力下降。实时PCR、蛋白印迹结果显示STAT3、P—STAT3蛋白表达下降，TwIsT基因表达量极少，Snail mRNA和蛋白表达明显下调（P〈0．05），E-cadherin明显上调（P〈0．05）。结论STAT3信号通路在胰腺癌上皮间质转换中起着重要作用。沉默STAT3基因可抑制人胰腺癌细胞上皮间质转换过程。

Objective To investigate the effect and mechanism of RNAi-mediated STAT3 gene silencing on epithelial-to-mesenehymal 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 ceils. 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.