酪氨酸激酶Etk/BMX对鼻咽癌细胞放射敏感性的影响

Effects of Tyrosine Kinase Etk/BMX on Radiosensitivity of Nasopharyngeal Carcinoma Cell Lines

目的研究酪氨酸激酶Etk/BMX对鼻咽癌细胞放射敏感性的影响并探讨其可能机制。方法利用脂质体2000将野生型酪氨酸激酶Etk/BMX表达质粒pcDNA3.0-Etk导入Etk/BMX低表达水平的鼻咽癌细胞株Sune-1中,建立Etk/BMX稳定高表达细胞株Sune-wt,空质粒pcDNA3.0转染细胞作为对照(Sune-vector)。X射线(0、2、4、10、15Gy)照射后,MTT法测定细胞的生存分数(sur-vival fraction,SF);流式细胞术检测细胞的凋亡率、细胞周期、增殖指数以及凋亡相关蛋白p53和bcl-2的变化情况。结果不同剂量X线照射后Sune-wt较Sune-1和Sune-vector生存分数(SF)均显著增高而凋亡均显著减少(P<0.05),累计剂量15Gy后出现明显S、G2期阻滞,增殖指数增高。Sune-wt照射前后p53和bcl-2的表达水平出现显著改变(P<0.05)。结论 Etk/BMX有增强鼻咽癌细胞对放射线的抵抗作用,其可能是通过调控p53和bcl-2的表达以及引起S、G2期阻滞两种途径实现的。

Objective To study the relationship between the tyrosine kinases Etk/BMX and radiosensitivity in nasopharyngeal carcinoma （NPC） cells.Methods Recombinant plasmid pcDNA3.0-Etk was transfected into Sune-1,and Etk was highly expressed in the transfeced cell line Sune-wt.After 0,2,4,10,15Gy X ray radiation,MTT was used to measure survival fraction（SF） and flow cytometer （FCM） assay to examine cell apoptosis rate,cell cycle,proliferation index（PI）,and apoptosis-related protein p53 and bcl-2.Results After different X ray radiations the survival fraction of Sune-wt were all higher than those of Sune-1 and Sune-vector（P〈0.05）. The cell apoptosis rate of Sune-wt were all dramatically lower than those of Sune-1 and Sune-vector（P〈0.05）.There was S,G2 phase blockage and highly up-regulated of proliferation index in Sune-wt after 15 Gy irradiation dosages.Moreover,there were significantly different expression of p53 and bcl-2 in Sune-wt after 15Gy irradiation （P〈0.05）.Conclusions This study suggested that Etk/BMX played an important role in protecting nasopharyngeal carcinoma cells from X ray irradiation.Its mechanics may be ralated to p53 and bcl-2 changing and S,G2 phase blockage.