摘要
目的观察放射诱导人胃癌细胞株SGC-7901凋亡的作用,并进一步研究bcl-2基因及家族、bax基因、p53基因在此过程中的作用。方法用不同剂量的9 MeVβ线照射SGC-7901细胞,观察细胞在受照后的不同时间生长情况。电子透射电镜下观察细胞形态变化。琼脂糖凝胶电泳检测DNA条带变化。流式细胞仪检测受照前后细胞周期及凋亡率的变化。免疫细胞化学法检测受照前后bcl-2、bax、p53基因的表达水平。结果单次剂量照射后,SGC-7901细胞凋亡率与时间、剂量有相关性。在放射诱导SGC-7901细胞凋亡的过程中,bcl-2基因表达水平下降,bax基因表达水平升高,而p53基因表达水平无变化。结论放射能够诱导胃癌细胞株SGC-7901凋亡,凋亡率在72h达高峰。bcl-2及bax基因参与了放射诱导凋亡的调控。细胞凋亡主要是通过p53基因非依赖途径。
Objective To study the radiation-induced apoptosis in cultured human gastric SGC-7901 cell line and investigate the role of bel-2 gene family and p53 gene in this process. Methods After having been exposed to different irradiation doses by 9 MeV β-ray, the cell morphology of human gastric SGC-7901 cell line was observed under electron microscope; DNA ladder was demonstrated on DNA electrophoresis; cell apoptosis was analyzed by flow cytometry; the oncoprotein of p53 and bcl-2, bax gene were detected by immunocytochemical method. Results The apoptosis ratio in human gastric SGC-7901 cell line was 0.14 ± 0.11, 0.71 ± 0.13, 2.63± 0.73 and 10.89 ± .45 at 2, 24, 48, 72 hours after 5 Gy irradiation, the ratio was 1.61 ± 0.35, 2.44 ± 0.31, 5.56 ± 0.8 land 24.27 ± 1.77 after 20 Gy irradiation, whereas the ratio in the control group was 0.33 ± 0.34, 0.28 ± 0.31, 0.25±0.26 and 0.27 ± 0.22, respectively. The labeling index of p53 was 34.7% in the control group and 32.1%, 32.6%, 32.6% and 33. % at 2, 24, 48, 72 hours in 20 Gy irradiation group, P 〉 0.05; the labeling index of bcl-2 was 24.5% in the control group and 22%, 14.9%, 10.3% and 2.0% at 2, 24, 48, 72 hours in 20 Gy irradiation group, P 〈 0.001 ; the labeling index of bax was 28.3% in the control group and 30.8%, 33.9%, 37.1% and 54.4% at 2, 24, 48, 72 hours in 20 Gy irradiation group, P 〈 0.001 Conclusions Single dose irradiation can induce apoptosis in human gastric SGC-7901 cell line and this process is time- and dose-dependent, with the apoptotic peak reaching the top at 72 hours after radiation, bel-2 gene family plays an important role in radiation-induced apoptosis in human gastric SGC-7901 cell line, Apoptosis may occur predominantly via a p53-independent pathway.
出处
《中华放射肿瘤学杂志》
CSCD
北大核心
2005年第5期447-450,共4页
Chinese Journal of Radiation Oncology
