腺病毒介导的野生型p53基因对人肺腺癌细胞放疗敏感性的影响

Effect of Adenovirus-mediated wild-type p53 gene transfection on the growth and radiosensitivity of human lung adenocarcinoma cells

目的:研究腺病毒介导的野生型p53基因(Ad-p53)对人肺腺癌细胞生长及放疗敏感性的影响。方法:将重组的含野生型p53基因的腺病毒导入A549细胞,通过免疫细胞化学方法检测p53基因的表达。A549细胞分为4组:对照组、转染组、放疗组、转染联合放疗组。用四甲基偶氮唑盐比色法(MTT法)和流式细胞仪检测p53基因以及联合放射治疗(2,4,6 Gy)对A549细胞生长抑制及凋亡的影响。结果:通过免疫细胞化学方法证实了p53基因在A549细胞中的表达。MTT法检测发现p53基因对A549细胞的生长抑制率为(50.60±5.69)%。当放射剂量为2,4,6 Gy时,A549细胞的生长抑制率分别为(16.06±4.35)%、(16.39±1.67)%、(17.73±4.68)%。当p53基因与放疗(2,4,6 Gy)联合作用时,抑制率分别为(80.60±5.35)%,(89.30±1.67)%、(90.30±2.01)%(P<0.01)。p53基因转染所产生的A549细胞凋亡率为(10.38±1.68)%。放疗(2,4,6 Gy)引起的细胞凋亡率分别为(3.98±0.72)%、(4.84±0.60)%、(5.40±0.70)%。当p53基因与放疗(2,4,6 Gy)联合作用时,凋亡率分别为(17.80±1.30)%、(19.03±0.54)%、(21.34±2.51)%(P<0.01)。结论:野生型p53基因与放疗对人肺腺癌细胞生长有协同抑制作用。

Objective： To evaluate the effects of wild-type p53 gene on the growth and radiosensitivity of human lung adenocarcinoma ceils. Methods： Recombinant adenovirus carrying wild-type p53 gene （Ad-p53 ） was transferred into human lung adenocarcinoma cell A549, and p53 protein expression was detected by immunocytochemistry. A549 cell was divided into 4 groups ： control group, transfection group, radiation group and combined treatment group. The cell growth inhibition and apoptosisin were assessed by MTT and flowcytometry. Results ： The transfection of p53 gene into A549 ceils was confirmed by immunocytochemistry. MTT showed that the inhibition rate （IR） on the growth of A549 ceils transferred into by Ad-p53 gene was （50.60 ± 5.69 ） %. The IR of radiation （2,4,6 Gy ） on A549 cells was respectively （ 16.06 ± 4.35） %, （ 16.39 ± 1.67 ） %, （ 17.73 ± 4.68） %. When combined treatment of wild-type p53 gene transfection and radiation was used, their IR was （80.60 ±5.35）%, （89.30 ± 1.67）%, （90.30 ±2.01 ）%, significantly increased （P 〈 0.05）. The apoptotic rate（AR） of A549 ceils induced by p53 gene transfection was （ 10.38 ± 1.68 ） %. Their AR by radiation （ 2,4,6 Gy） was （ 3.98 ± 0.72 ） %, （4.84 ± 0.60） %, （5.40 ±0.70）%. The apoptotic rate was also significantly increased to （ 17.80 ± 1.30）%, （ 19.03 ± 0.54 ） % , （ 21.3 4 ± 2.51 ） % respectively aftercombined treatment of p53 and radiation （ 2,4,6 Gy ） with different doses（ P 〈 0.05 ）. Conclusion： Wild-type p53 gene and radiation could result in synergistic inhibition effect on the growth of human lung adenocarcinoma cells and increase radiosensitivity.