Livin异构体基因转染对肺腺癌A549细胞生长及放化疗敏感性的影响

目的研究转染Livin α、β两种异构体基因对肺腺癌A549细胞生长及放、化疗敏感性的影响。方法基因转染获得稳定表达Livinα和β的A549细胞克隆，逆转录一聚合酶链反应及免疫荧光化学法了解Livin α、β在转染细胞中基因水平和蛋白水平的表达情况；用平板克隆形成实验研究细胞生长情况；甲基偶氮唑蓝法研究细胞对放、化疗的敏感性；细胞周期分析法了解细胞凋亡情况。结果与转染前比较，基因转染后，阳性细胞尤其是表达Livin α的A549细胞克隆形成能力提高约20％、倍增时间缩短5～6h（P〈0．05），对多种化疗药物和放射线敏感性降低（P〈0．01），10Gy放射线照射下仅有0．2％细胞发生凋亡。结论Livin尤其是Livin α参与肺癌的发生发展，是肺癌细胞对放、化疗耐受的重要机制之一。

Gene transfection of Livin isoforms into A549 cell line and its effect on cell growth and sensitivity to chemotherapy and radiotherapy

OBJECTIVE: To express Livin alpha & beta in A549 cells by using gene transfection, and to observe its effect on cell growth and cell sensitivity to chemotherapy drugs and radiation. METHODS: Eukaryotic expression vectors of Livin alpha & beta were transfected into A549 cells and cell clones with stable expression were obtained. Livin alpha & beta expression levels in the transfected A549 cells were assessed at mRNA level and protein level, respectively. Cell growth status was assessed by biological features. MTT was performed to test effects of Livin on sensitivity of the A549 cells to chemotherapy drugs and radiation, and cell cycle analysis was performed to evaluate cell apoptosis. RESULTS: After transfection, positive cells, especially A549 cells expressing Livin, showed an increase of about 20% in colony-forming ability, a shorter doubling time (P < 0.05) and lower sensitivity to chemotherapy drugs and radiation (P < 0.01). Only 0.2% of the cells committed apoptosis with 10 Gy radiation. CONCLUSION: Livin isoforms, especially Livin alpha, are implicated in genesis and development of lung cancer, thus may be an important mechanism for drug resistance of lung cancer cells.