Notch信号通路对人胰腺癌细胞NF—κB活性和侵袭能力的影响

背景：Notch信号通路在多种人类恶性肿瘤的发生、发展中起关键作用。研究显示Notch与NF—κB信号通路之间的交互作用可促进胰腺癌进展。目的：明确Notch信号通路对胰腺癌侵袭性的影响及其可能机制。方法：体外培养人胰腺癌细胞株BxPC3，以Notch-1siRNA下调其Notch-1表达，同时设置转染对照siRNA的阴性对照组和不予siRNA干扰的空白对照组。以Transwell细胞侵袭实验观察各组BxPC3细胞的侵袭能力，电泳迁移率变动分析（EMSA）检测NF—κB活性，蛋白质印迹法检测Notch-1、NF—KBp65、血管内皮生长因子（VEGF）、基质金属蛋白酶-9（MMP．9）蛋白表达。结果：经Notch-1siRNA干扰、Notch-1表达下调的BxPC3细胞，Transwell细胞侵袭实验穿膜细胞数较空白对照组和阴性对照组显著减少（26．5±1．3对78．5±2．4和76．7±2．2，P〈0．01），NF—κB活性显著降低（P〈0．01），NF-κB p65、VEGF、MMP-9蛋白表达显著下调（P〈0．05）。结论：Notch-1可通过激活NF—κB促进其下游基因VEGF、MMP-9表达，由此增强胰腺癌的侵袭性。

Effect of Notch Signaling Pathway on NF-kB Activation and Invasiveness of Human Pancreatic Cancer Cells

Background:Notch signaling pathway plays a critical role in the pathogenesis and progression of various human malignancies.It has been demonstrated that crosstalk between Notch and NF-κB signaling pathways promotes pancreatic cancer progression.Aims:To study the effect of Notch signaling pathway on invasion of pancreatic cancer and its possible mechanism.Methods:Human pancreatic cancer cell line BxPC3 was cultured in vitro and transfected with Notch-1 siRNA to down-regulate Notch-1 expression.BxPC3 cells transfected with controlled siRNA served as negative controls and those without siRNA interference served as blank controls.Invasive capacity of BxPC3 cells was assessed by Transwell cell invasion assay.NF-κB activity and the protein expressions of Notch-1,NF-κB p65,vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9(MMP-9) were determined by electrophoretic mobility shift assay(EMSA) and Western blotting,respectively.Results:Expression of Notch-1 in BxPC3 cells was significantly inhibited by siRNA interference.Compared with blank control group and negative control group,the number of penetrating cells in Transwell cell invasion assay was significantly reduced in Notch-1 siRNA transfected BxPC3 cells(26.5±1.3 vs.78.5±2.4 and 76.7±2.2,P <0.01);the NF-κB activity,as well as the protein expressions of NF-κB p65,VEGF and MMP-9 in Notch-1 siRNA transfected group were also decreased significantly(P<0.05).Conclusions:Notch-1 may activate NF-κB and subsequently up-regulate its target genes,such as VEGF and MMP-9 expressions,resulting in pancreatic cancer invasion.