腺病毒介导的野生型p53基因逆转乳腺癌耐药细胞株MCF-7／A耐药性的研究

Reverse effect of adenovirus-mediated Wt-p53 on drug resistance of breast cancer cell line MCF-7/A

目的探讨野生型p53基因对乳腺癌耐药细胞株MCF-7／A耐药性的逆转作用及其机制。方法选用含野生型p53基因的重组腺病毒载体，转染乳腺癌耐药细胞株MCF-7／A，绘制细胞生长曲线，利用流式细胞计数仪检测细胞周期分布及凋亡分析、TUNEL法检测细胞凋亡的发生，并采用逆转录-聚合酶链反应（RT—PCR）和Western blot印迹转移检测p53基因的表达情况。结果野生型p53基因转染MCF-7／A后的24、48h均检测到p53基因的表达，并显著抑制MCF-7／A细胞的增殖；细胞周期发生改变，转染后的MCF-7／A的G0～G1期DNA百分含量（76．22％）明显高于对照组（43．64％，P〈0．05），凋亡率（10．76％）与对照组（1．48％）之间差异有统计学意义（P〈0．05）。结论重组腺病毒介导的野生型p53基因对乳腺癌耐药细胞株MCF-7／A的耐药性有明显的逆转作用，其机制可能是引起明显的G1期阻滞并诱导细胞凋亡。

Objective To explore the reverse effect of Wt-p53 gene on drug resistance of breast cancer cell line MCF-7/A and its possible mechanism. Methods Wt-p53 gene was tranfeeted into MCF- 7/A cells through rebuilding adenovirus. The cell growth curve was drawn, and the cycle distribution and apoptosis were checked by FCM. The apoptosis of MCF-7/A cells was examined by TUNEL. The expression of Wt-p53 mRNA and protein in MCF-7/A cells was detected by PT-PCR and Western blot respectively. Results In the transfeetion group of MCF-7/A cells, there was obvious proliferation, and the expression of p53 mRNA and protein was detected 24 and 48 h later. Aneuploid peak before G1 stage indicated DNA destruction and cell apoptosis, The DNA content in transfection group in G0-G1 stage （76.22%） was significantly higher than control group （43.64%） （P 〈 0.05 ）. The TUNEL verified that there was an apparent apoptosis signal in which the apoptosis rate of transfected MCF-7/A was 10.76% ,while that was 1.48% in control group （ P 〈 0.05 ）. Conclusion Recombinant adenovirus-mediated Wt-p53 has an apparently reverse effect on drug resistance of breast cancer MCF-7/A cells by inducing cell apoptosis and apparent G1 stage arrest.