Polo-like激酶l反义RNA对肺癌细胞A549生长的实验研究

Effect of antisense RNA targeting Polo-like kinase 1 on cell growth in A549 lung cancer cells

目的:探讨Polo-like激酶1(Plk1)基因表达下调对肺癌细胞周期分布及其生长的影响。方法:培养肺腺癌细胞株A549,构建表达Plk1反义RNA的质粒pcDNA3-Plk1,通过脂质体介导转染A549细胞,采用RT-PCR和Western blotting的方法检测Plk1基因的表达,细胞计数、BrdU脉冲标记检测细胞增殖,流式细胞仪分析细胞周期变化和凋亡,MTT法检测长春瑞宾(NVB)对各组细胞的生长抑制率。结果:A549细胞转染pcDNA3-Plk1后24h,Plk1mRNA及蛋白表达均下降;细胞变圆、漂浮、增殖减慢;S期细胞百分数(BrdU标记指数)显著低于对照组(P<0.05);转染后48hA549细胞出现G2/M期阻滞(P<0.05)并发生凋亡;等浓度化疗药物诺维本对转染pcDNA3-Plk1细胞的抑制率明显高于各对照组(P<0.05),转染pcDNA3与未转染的对照细胞差异无显著(P>0.05)。结论:pcDNA3-Plk1的转染能下调Plk1基因的表达,抑制A549细胞增殖,诱导凋亡,并能增加A549细胞对化疗药物的敏感性。

AIM ： To investigate the effect of Polo - like kinase - 1 （ Plkl ） depletion on cell cycle progression and cell growth in lung cancer cells, METHODS： A recombinant plasmid containing antisense RNA targeting Plkl （pcD- NA3 - Plkl ） was transfected into A549 cells by lipofectine. RT - PCR and Western blotting were used to examine Plkl gene expression. Cell proliferation was evaluated by cell counting and BrdU labeling. Cell cycle distribution and apoptosis were examined by flow cytometry. Inhibition rate （IR） of vinorebline （NVB） was determined by MTT assay. RESULTS： After transfected with pcDNA3 - Plkl into A549 cells, the expression levels of Plkl mRNA and protein were greatly decreased. Abnormal morphological changes of cells and growth inhibition were observed in pcDNA3 - Plkl transfected cells. The BrdU labeling index was significantly lower than that in control group （P〈0. 05 ）. Cells showed a strong G2/M arrest and apoptosis 72 h post transfection. IR of vinorebline in pcDNA3 - Plkl transfected groups was significantly higher than that in other groups. CONCLUSION ： Antisense RNA targeting Plkl is capable of suppressing Plkl expression, and therefore, significantly inhibits cellular proliferation, induces cell cycle arrest and apoptosis. Moreover, the sensitivity of lung cancer cells to chemotherapy is increased.