UCN-01增加鼻咽癌细胞株放射敏感性的研究

Abrogation of Radiation-Induced G2Arrest and Radiosensitization by 7-Hydroxyst aurosporine(UCN-01)in Human Nasopharyngeal Carcinoma Cell Line

背景与目的:应用药物提高肿瘤组织的放射敏感性,是改善放疗疗效的主要研究方向之一。本研究通过观察已知p53基因突变的鼻咽癌CNE-1细胞照射后G2期阻滞的情况,以及药物7-hydroxystaurosporine(UCN-01)是否能够去除此G2期阻滞并增加放射敏感性,探讨UCN-01增加放射敏感性的机制。方法:用细胞培养和流式细胞仪(FCM)技术分析X线照射对CNE-1细胞周期(特别是G2期阻滞)的影响,观察UCN-01对放射引起的G2期阻滞的影响。应用细胞克隆形成实验观察UCN-01去除G2期阻滞对放射敏感性的影响。结果:照射明显导致CNE-1细胞G2期阻滞,未照射组(对照组)及照射2Gy、4Gy和6Gy组的细胞G2期比例分别为18.4%、43.6%、77.4%和86.4%,G2期阻滞的程度与照射剂量正相关。UCN-01能够去除放射引起的CNE-1细胞G2期阻滞,50nmol/L、100nmol/L、200nmol/L和400nmol/LUCN-01组细胞的G2比例由对照组的63.5%分别降至28.5%、25.0%、16.1%和13.7%,UCN-01去除G2期阻滞的程度与药物浓度正相关。UCN-01能明显降低放射后CNE-1细胞的克隆形成率,100nmol/L和200nmol/LUCN-01组的放射增敏比分别为2.60和3.09。结论:UCN-01对CNE-1细胞有放射增敏作用,其机制可能与UCN-01去除放射引起的G2期阻滞有关。

BACKGROUND &OBJECTIVE:To enhance the radiosensitivity of cancer cell is one of the most impor tant way to improve the effect of radiotherapy.This study was desig ned to investig ate the radiosensitiz ation of 7-hydroxystaurosporine(UCN-01)by its abrog ation of radiation-induced G 2 arrest.METHODS :Flow cytometry was used to observe th e effect of irradiation and UCN-01on cell cycle of human naso pharyng eal carcinoma cells(CNE-1)with mutated p53.The effect on radio sensitivity was determined by clono g enic assay and was quantified by calculat ing the sensitive enhancement ratio(SER).RESULTS :Irradiation resulted in G 2 arrest in a dose-dependent manner.T he proportion of cells at G 2 phase,comparing to the control g roup(18.4%),was increased to 43.6%,77.4%and 86.4%a fter 12hours with irradiation of 2,4and 6Gy,respectively.Radiation-induced G 2 arrest was abrog ated by UCN-01in a concentration-dependent manner.UCN-01at the concentrations of 50,100,200and 400nmol /L decreased the prop ortion of cells in G 2 phase from 63.5%in the control g roup to 28.5%,25.0%,16.1%and 13.7%,respectively.UCN-01resulted in a radiosensitiza tion in CNE-1cells.The SERs were 2.60and3.09,for 100nmol /L and 200nmol /L of UCN-01,respectively.CONCLUSION:Radiosensitization of UCN-01in CNE-1cells characterized by mutated p53is associated with its abrog ation of ra diation-induced G 2 arrest.