RASSF1A基因转染对人肺腺癌细胞株A549增殖的抑制作用

Proliferation inhibition of human lung adenocarcinoma cell line A549 transfected by RASSF1A gene

目的:观察外源性RASSF1A基因对人肺腺癌细胞A549增殖及NF κB亚单位P65表达的影响。方法:利用脂质体转染技术将真核表达重组体pcDNA3. 0 RASSF1A质粒和空载体pcDNA3. 0质粒分别导入A549细胞,经G418筛选后获得稳定转染细胞克隆,Westernblotting检测RASSF1A基因表达。采用MTT(四甲基偶氮唑盐)法、流式细胞仪分析转染细胞的生物学行为。RT PCR和Westernblotting检测基因转染对P65表达的影响。结果:经脂质体转染和筛选,建立了稳定表达RASSF1A基因的A549细胞系。与未转染组和转染空白载体组比较,转染RASSF1A基因的细胞生长速度明显减慢(P<0. 05),细胞周期中G1 /G0期比例明显增加(P<0. 05),而S期比例减少;转染组细胞核内P65蛋白表达明显降低(P<0. 05),而全细胞P65蛋白及mRNA表达未见明显变化。结论:RASSF1A基因可能通过抑制P65活性而抑制人肺腺癌细胞A549的生长。

Objective To determine the effects of exogenous RASSF1A gene on the proliferation and expression of P65 and subunit of NF-κB, in lung adenocarcinoma cell line A549. Methods pcDNA3.0-RASSF1A and pcDNA3.0 were introduced into A549 cell line by lipofectin transfection, and the A549 cells stably expressing RASSF1A gene were established by G418 selection. The expression of RASSF1A was detected by Western blotting. The cytobiologic characterizations of the positive clone were analyzed by methythiazoletertraolium (MTT) assay and cytometry. The expressing of P65 was analyzed by RT-PCR and Western blotting. Results A549 cells stably expressing RASSF1A protein were established by lipofection mediated transfection and selected for further study. Compared with the nontransfected and vector transfected cells, the positive clone cells grew more slowly. Flow cytometric data showed that more positive clone cells went into phase G 0 /G 1 and fewer cells went into phase S. The expression of P65 in nuclear protein in positive clone cells was lower than that of the control group while there was no obvious difference between the expression of p65 mRNA and P65 protein in total protein among the 3 groups. Conclusion RASSF1A gene might suppress the proliferation of A549 cells through blocking the activity of P65 protein.