RNAi沉默DLL4基因对人乳腺癌细胞株MCF-7增殖与凋亡的影响

Effect of RNAi silencing of the DLL4 gene on proliferation of human breast carcinoma cell MCF-7 cells

目的:探讨利用RNA干扰沉默Delta样配体4(Delta-like ligand 4,DLL4)对MCF-7细胞生长、凋亡的影响,为乳腺癌的基因治疗提供一个可选择的靶点和方法。方法:针对DLL4基因的DNA设计具有特异性的SiRNA,经脂质体转染MCF-7,采用免疫组化方法检测空脂质体组和转染组DLL4基因表达有否阻断。用MTT法测定MCF-7细胞生长曲线,流式细胞仪检测细胞凋亡率及细胞周期改变。结果:构建DLL4-SiR-NA表达载体能够有效抑制MCF-7中DLL4的表达(P<0.05)。RNA干扰沉默DLL4基因可抑制MCF-7细胞增殖,促进细胞凋亡,G2/M期细胞比例明显增加(P<0.05)。结论:RNAi技术能够有效抑制DLL4基因的表达,抑制DLL4基因的表达可抑制MCF-7细胞增殖,促进MCF-7细胞凋亡。

Objective：To inhibit the expression of DLL4 gene in human breast carcinoma cell MCF-7 cells by SiRNA on proliferation and apoptosis.Methods： The specific SiRNA was designed for DLL4 gene and transfected into human breast carcinoma cell MCF-7 cells with liposomal,to study whether the expression of DLL4 gene can be blocked.Immunohistochemical method was used to detect in contol and transfected groups.Proliferation of MCF-7 cells was examined by MTT assay.Apoptosis of MCF-7 cells was examined by FCM.Cell cycle distribution of MCF-7 cells was analyzed by FCM.Results： The constructed vector could effectively inhibit the expression of DLL4 in MCF-7 cells.Knockdown of Notch ligand DLL4 expression by RNAi could reduce proliferation and induce apoptosis in the MCF-7 cells.Decreased DLL4 expression could lead to cell cycle G2/M arrest.Conclusion： The RNA interference technology could effectively block the DLL4 gene expression.Inhibition of Dll4/Notch signaling pathway can lead to inhibition of cancer cell proliferation and a concomitant increase in cells undergoing apoptosis,and thus,Dll4 would be an important target for cancer therapeutic approach.