利用反义技术抑制人乳头瘤病毒18 E6/E7的表达及其对宫颈癌HeLa细胞增殖凋亡的影响

目的 构建人乳头瘤病毒（HPV）18型E6／E7反义荧光真核表达载体,研究其对宫颈癌HeLa细胞增殖凋亡的影响。方法 以PCR法扩增HPV18型E6／E7区716bp片段并反向克隆到荧光真核表达载体pEGFP-C1,构建重组体pEGFP-HPV18E6E7as（EGFP-18AS）并转染人宫颈癌HeLa细胞。利用逆转录聚合酶链反应（RT—PCR）和Western印迹技术检测转染后E6、E7基因在mRNA和蛋白水平的变化;用四甲基偶氮唑盐微量酶反应比色法检测转染后细胞的的增殖活性;用流式细胞仪检测转染后细胞的凋亡率;荧光显微镜下观察凋亡细胞的形态学改变。结果 转染EGFP-18AS重组体后,HeLa细胞中E6、E7基因的mRNA表达和蛋白合成均明显下调;细胞增殖受到抑制;流式显示细胞G1期明显阻滞;同时在荧光显微镜下经Hoechst染色凋亡细胞出现染色质凝集、边集、碎裂等形态学改变。结论 重组质粒pEGFP—HPV18E6E7as能有效地抑制人宫颈癌HeLa细胞的生长和增殖,诱导其凋亡,证明了反义RNA技术的有效性,为宫颈癌的基因治疗提供了一种新的可能的途径。

Antisense targeting to human papillomavirus 18 E6/E7 affects the proliferation and apoptosis of human cervical carcinoma: an in vitro experiment with HeLa cells

OBJECTIVE: To investigate the effect of eukaryotic fluorescent expression vector carrying antisense human papillomavirus (HPV) 18 E6/E7 on the growth and proliferation of human cervical carcinoma. METHODS: The HPV18 E6E7 with the length of 716 bp was amplified by PCR, the PCR product was inversely inserted into the eukaryotic fluorescent expression vector pEGFP-C1 so as to construct the recombinant eukaryotic expression plasmid pEGFP-HPV18E6E7as (EGFP-18AS). Human cervical carcinoma cells of the line HeLa were cultured and randomly divided into 3 groups: Group A transfected with the recombinant plasmid EGFP-18AS, Group B transfected with the blank plasmid pEGFP-C1, and Group C without transfection used as control group. The mRNA expression of HPV 18 E6/E7 in the HeLa cells was detected by RT-PCR and protein expression of HPV18 E6/E7 HPV 18 E6/E7 in the HeLa cells was detected by. Western blotting MTT assay was performed to dynamically monitor the surviving cells and the cell apoptosis was observed by flow cytometry and fluorescence microscopy. RESULTS: The protein and mRNA expression levels of HPV18 E6/E7 in the HeLa cells transfected with HeLa/18AS were both remarkably lower than those in the HeLa cells transfected with blank plasmid and those of the control group. The numbers of surviving HeLa cells of Group A was significantly lower than those of Groups B and C (both P < 0.05). The phenomenon of arrest of G(1) phase was remarkable in Group A. The apoptotic rate of the cells of Group A was 47.21%, significantly higher than those of Groups B and C (14.18% and 3.36% respectively, both P < 0.05). An increased number of cells with chromosome condensation and fragmentation was found in Group A as compared with Groups B and C. CONCLUSION: The recombinant pEGFP-HPV18E6E7as can effectively inhibit the growth and proliferation of human cervical carcinoma HeLa cells, and further induce the cell apoptosis. The antisense RNA technology is available and may provide a new way to gene therapy of the cervical carcinoma.