Notch 1信号途径的激活及其对宫颈癌细胞凋亡的影响

Activation of Notch1 Signaling Pathway and Its Effects on Hela Cell Apoptosis

目的探讨Notch1信号途径在宫颈癌细胞中的激活,并研究其对宫颈癌细胞凋亡的影响。方法扩增人胎盘组织细胞内的全长NICD,并构建pcDNA3.1-NICD真核表达载体。通过脂质体转染宫颈癌细胞,筛选稳定表达NICD的宫颈癌细胞株。通过RT-PCR及Western blotting检测Notch1和Hes1基因的表达,并通过流式细胞仪观察其对宫颈癌细胞凋亡的影响。结果未处理及转染pcDNA3.1和pcDNA3.1-NICD的Hela细胞中均存在Notch1及Hes1基因的表达,表明该信号通路在Hela细胞中处于激活状态。然而,转染NICD的宫颈癌细胞株Notch1及Hes1的表达明显升高,提示该通路可能在外源NICD的影响下处于过度激活状态。流式细胞仪检测结果显示,在未处理和转染pcDNA3.1的Hela细胞中,细胞凋亡率差异无统计学意义(P>0.05);但与未处理的和转染pcDNA3.1的Hela细胞相比,稳定表达NICD的Hela细胞的细胞凋亡率明显增加(P<0.01)。结论外源的NICD通过Notch1信号途径能引起宫颈癌细胞的凋亡,提示Notch1可能成为治疗宫颈癌的分子靶点。

Objective This study was to investigate the activation of Notch1 signaling pathway in uterine cervical carcinoma and its effects on cell apoptosis. Methods The full length of NICD of Notch1 gene was amplified, and a eukaryotic expression pcDNA3.1-NICD was constructed and transfected into Hela cells. Hela cells stably expressing NICD were screened out. The expression of Notch1 and Hesl genes were detected by RT-PCR and Western blotting methods. Cell apoptosis was measured by flow cytometry （FCM）. Results There was the expression of Notch1 and Hesl genes in Hela cells untreated, transfected with pcDNA3.1 and pcDNA3.1 - NICD, implying an activation status. However, compared to untreated and transfected with pcDNA3. 1, the expression of Notch1 and Hesl genes markedly increased in Hela cells stably expressing NICD, suggesting Notch1 signaling pathway was in the extra -activation status. The apoptotic rate was significantly higher in Hela cells stably expressing NICD than in untreated and pcDNA3.1-transfected cells （P 〈0.01 ）; there was no prominent difference between untreated and pcDNA3.1-transfected Hela cells （P 〉0.05）. Conclusion Foreign NICD gives rise to the apoptosis of Hela cells via Notch1 signaling pathway, suggesting that Notch1 gene may be a new therapeutic target for cervical carcinoma.