摘要
目的：探讨辐射诱导表达载体pcEgr-hp53体外稳定转染人肺腺癌A549细胞后联合X射线照射,诱导细胞凋亡的作用及相关凋亡蛋白Bax、Bcl-2和caspase-3蛋白表达的变化。方法：以脂质体介导携有外源野生型p53基因的辐射诱导表达载体pcEgr-hp53和pcDNA3.1,体外转染A549细胞,筛选稳定转染的细胞克隆并扩增培养,所表达的A549-hp53和A549-vect分别接受0、0.5、2和5Gy X射线照射,即8个实验组,采用TUNEL法和流式细胞术检测稳定转染联合辐射对细胞凋亡和Bax、Bcl-2和caspase-3蛋白表达变化的影响。结果：A549-hp53组加不同剂量照射与0 Gy组比较,其百分数均明显增加（0.5-5Gy,P〈0.05-P〈0.01）,Bcl-2蛋白表达在0.5-5Gy时明显下降,而Bax蛋白明显增加（P〈0.05-P〈0.01）,caspase-3蛋白表达在2-5Gy时明显增加（P〈0.01）;A549-hp53照射组不同剂量照射,与A549-vect相应照射剂量组比较,其百分数在0.5Gy时无明显差异,在2-5 Gy时为（P〈0.01）,Bcl-2蛋白表达明显下降（0.5Gy,P〈0.01;2-5Gy,P〈0.05）,Bax和caspase-3蛋白表达0.5-5Gy时明显增加（P〈0.05-P〈0.01）。结论：体外p53基因转染联合X射线照射可诱导肿瘤细胞凋亡明显增多,凋亡相关蛋白Bcl-2表达下调,Bax、caspase-3表达上调,具有显著的肿瘤抑制作用。
Objective： To investigate the effect of recombinant plasmid pcEgr-p53 stable transfection in combination with X-ray irradiation on the apoptotic effect and the changes of Bax, Bcl-2 and caspase-3 protein expressions in human A549 tumor cells. Methods： pEgr-hp53 packaged with liposome was stably transfected into A549 cells in vitro. These cells of expressing A549-hp53 and A549-vect were irradiated with 0,0.5,2 and 5 Gy X-rays, respectively, i. e. 8 experimental groups. The A549 cells responding to the apoptotic effect and the changes of Bax, Bcl-2 and caspase-3 protein expressions were measured with TUNEL assay and flow cytometry,respectively. Results： The percentage of apoptotic cells in A549-hp53 plus different dose irradiation group were significantly higher than that in 0 Gy group （ P 〈 0.05 - P 〈 0.01 ） ,and Bax protein expression marklly down-regulated, Bcl-2 and caspase-3 protein expressions were significantly up-regulated（ P 〈 0.05- P 〈 0.01 ）. The percentage of apoptotic cells in A549-hp53 plus irradiation group（2 - 5 Gy） were markedly higher than that in corresponding A549-vect plus irradiation group （ P 〈 0.01 ）, and Bcl-2 protein expression was down-regulated（0.5 Gy, P 〈 0.01 ;2- 5 Gy, P 〈 0.05）, and expression of Bax and caspase-3 proteins was up-regulated （0.5- 5 Gy, P 〈 0.05- P 〈 0.01）. Conclusion： pEgr-hp53 stable transfection in combination with irradiation can significantly induce apoptosis of A549 tumor cells and down-regulate the expression of Bcl-2 protein and up-regulate the expressions of Bax and caspase-3 protein.
出处
《中国免疫学杂志》
CAS
CSCD
北大核心
2008年第6期521-525,共5页
Chinese Journal of Immunology
基金
国家自然科学基金(30570546)
吉林省科技厅科学基金(20050705-6)课题
