UCN-01去除放射后肿瘤细胞G_2期阻滞及其相关机制  

Abrogation Effect of UCN-01 on Radiation-induced G_2 Phase Arrest of Tumor Cells and Its Mechanism

作　　者：惠周光[1] 李晔雄[1] 杨伟志[1] 余子豪[1] 

机构地区：[1]中国医学科学院中国协和医科大学肿瘤医院放射治疗科,北京100021

出　　处：《癌症》2005年第1期1-6,共6页Chinese Journal of Cancer

基　　金：国家自然科学基金(10335050);教育部留学回国人员科研启动基金(D015);人事部留学回国人员科研基金(D015);中国医学科学院中国协和医科大学肿瘤医院科研基金(N033)~~

摘　　要：背景与目的:辐射对肿瘤细胞的影响常表现为细胞周期的改变。本研究观察X线照射后肿瘤细胞G2期阻滞及药物UCN鄄01去除此阻滞的情况,并进一步研究其相关机制。方法:选用已知p53突变的人鼻咽癌CNE鄄1细胞系和人肺腺癌973细胞系进行研究,并以p53功能正常的人纤维母细胞瘤HT鄄1080细胞系作为对照。采用细胞培养和流式细胞仪技术分析X线照射对以上细胞系的细胞周期的影响,并观察UCN鄄01对放射后细胞G2期阻滞的影响;应用蛋白印迹法(Westernblot)测定在UCN鄄01去除CNE鄄1细胞G2期阻滞的过程中,细胞内磷酸化CDC2鄄Tyr15含量的相应变化。结果:X线照射明显导致CNE鄄1细胞和973细胞G2阻滞,照射2Gy后两组的G2期细胞比例分别由18.4%和14.8%上升至43.6%和42.8%,两组细胞的G1期阻滞不显著,衡量G1期阻滞的指标“S期消耗率”均较低,分别为14.8%和-1.2%,明显低于p53功能正常的HT鄄1080细胞(57.0%)。UCN鄄01能够去除放射后CNE鄄1细胞和973细胞G2阻滞,两组的G2期细胞比例分别从单纯照射组的63.5%和35.4%降至16.1%和16.3%。CNE鄄1细胞照射后随着细胞G2期阻滞增加,磷酸化CDC2鄄Tyr15的含量相应增加,而UCN鄄01能够降低照射后细胞内磷酸化CDC2鄄Tyr15的含量,并与该药去除细胞G2期阻滞的过程相一致。BACKGROUND & OBJECTIVE: Irradiation often causes cell cycle arrest in tumor cells. This study was to observe the abrogation of radiation-induced G2 phase arrest of p53 mutated human cancer cell lines by 7-hydroxystaurosporine (UCN-01), and explore the mechanism. METHODS: Human nasopharyngeal carcinoma cell line CNE-1 and human lung adenocarcinoma cell line 973, both with p53 mutation, were used in this study. Human fibroblastoma cell line HT-1080 was used as control. Flow cytometry was used to observe the effects of irradiation on cell cycle of these 3 cell lines, and abrogation effect of UCN-01 on radiation-induced G2 phase arrest. Western blot was used to detect phosphorylated CDC2-Tyr15 during the abrogation process. RESULTS: Irradiation resulted in G2 phase arrest in CNE-1 cells and 973 cells. Proportion of cells in G2 phase increased from 18.4% to 43.6% in CNE-1 cell line, and from 14.8% to 42.8% in 973 cell line after 2 Gy of irradiation. G1 phase arrests, measured by 'S phase cells consumption', of CNE-1 cells and 973 cells were much lower than that of HT-1080 cells (14.8% and -1.2% vs. 57.0%). Radiation-induced G2 phase arrests were abrogated by UCN-01 from 63.5% to 16.1% in CNE-1 cell line, and from 35.4% to 16.3% in 973 cell line. UCN-01 suppressed the expression of radiation-induced phosphorylation of CDC2-Tyr15, which was in accordance with the abrogation of radiation-induced G2 phase delay. CONCLUSIONS: Main effect of irradiation on cell cycle of p53 mutated CNE-1 cells and 973 cells is G2 phase arrest. UCN-01 is able to abrogate radiation-induced G2 phase, which is associated with the reduction of phosphorylated CDC2-Tyr15.

关 键 词：鼻咽癌CNE-1细胞系 肺癌973细胞系 UCN-01 放射 细胞周期 P53 蛋白印迹法 

分 类 号：R73-36[医药卫生—肿瘤]