抑制mdr1基因对人宫颈癌细胞放射敏感性影响的实验研究

目的:探讨用反义技术抑制癌基因mdr1对宫颈癌细胞(HeLa)放射敏感性的影响。方法:设空白组、mdr1正义寡核苷酸组和脂质体组(仅加入等量的脂质体)为对照组以及mdr1反义寡核苷酸组,用RT-PCR检测宫颈癌细胞处理前后mdr1表达水平的变化。用集落形成试验检测各实验组照射后人宫颈癌HeLa细胞株集落形成率,AO/EB荧光染色法检测细胞凋亡率的变化,流式细胞仪测定Bcl-2蛋白的表达。结果:mdr1反义寡核苷酸能有效地抑制mdr1癌基因的表达,经脂质体介导的mdr1反义寡核苷酸作用的宫颈癌细胞经60Coγ射线照射后其集落形成率较正义寡核苷酸组及单纯照射组明显下降,而凋亡率明显增加,Bcl-2蛋白表达显著下调,与对照各组比较有显著差异(P<0.05)。结论:mdr1反义寡核苷酸通过抑制mdr1基因降低人宫颈癌HeLa细胞放射抗性。其辐射增敏作用可能与mdr1反义寡核苷酸增加照射后肿瘤细胞的凋亡率有关。

Effect of inhibiting mdr1 on radiosensitivity in human cervical carcinoma cell line HeLa

Objective：To explore the effect of inhibiting mdrl by antisense technology on radiosensitivity in human cervical carcinoma cell line HeLa. Methods： There were four groups in the study ： control group, lipofectin group, sense oligodexynucleotides （SODN） group, antisense oligodexynucleotides （ASODN） group. The expression of mdrl was detected by means of RT-PCR. Cellular response to irradiation was evaluated by the colony forming test. Apoptosis was observed by fluorescent staining. Bel-2 protein expression were determined by flow cytometry. Results：In AS-ODN group, the proliferation rate of irradiated HeLa decreased significantly and apoptosis increased and the expression of Bcl-2 was downregulated （P 〈 0.05 ）. Conclusion：mdrl antisense oligodexynucleotides sensitize the HeLa to ionizing irradiation through decreasing the expression of mdrl ,which may be related to increasing the apoptosis rate of HeLa cells.