单次照射胰腺癌细胞后放射损伤的初步观察  

Study on Irradiated Injury of Human Pancreatic Carcinoma Cell Line MIA PaCa-2 Induced by High Dose per Fraction

作　　者：王志震[1] 于海丽[1] 袁智勇[1] 王平[1] 

机构地区：[1]天津市肿瘤防治重点实验室,天津医科大学附属肿瘤医院放疗科,天津市300060

出　　处：《中国肿瘤临床》2010年第21期1237-1241,共5页Chinese Journal of Clinical Oncology

基　　金：永龄基金资助~~

摘　　要：目的:初步探讨单次照射胰腺癌细胞后,细胞的放射损伤状况。方法:采用不同单次剂量X射线(0、2、5、10、17Gy)对胰腺癌细胞系MIA PaCa-2照射,培养24h后观察形态学变化;放射后即刻行"彗星"分析;放射后6h和12h分别行DNA ladder检测;放射后0、6、12、24、36h行流式细胞术检测。结果:X射线照射后MIA PaCa-2胰腺癌细胞随剂量增加表现坏死明显,形态学改变以肿胀为基础;在低剂量组,以X射线照射MIA PaCa-2胰腺癌细胞可建立理想的由射线诱导的、呈剂量依赖性的细胞凋亡与坏死模型,引起G_2/M期阻滞,符合传统放射生物学概念;单次高剂量照射后细胞凋亡峰值出现早而明显;不同单次剂量X线照射后、量化细胞DNA损伤呈剂量依赖性,以10Gy最明显,17Gy反而减轻;随着放射剂量的增加,从单一的DNA电泳带,到出现多条典型的梯状图谱,以10Gy最明显。随着剂量进一步增加,出现模糊的无规律电泳梯带。结论:单次大剂量放射所致细胞损伤不同于常规剂量模式,可能以胀亡为主要细胞死亡方式。Objective： To initially observe the cellular irradiated injury by high dose per fraction. Methods： We cultivated human pancreatic carcinoma MIA PaCa-2 cells and and divided them into 0, 2, 5, 10, and 17 Gy groups. Cultivated cells were radiated by 6MV-X ray in one fraction with medical processing accelerator. We observed cellular morphous by histological technology after 24 hours. The degree of injury of DNA detected by comet assay instantly after radiation and by DNA ladder test at 6 and 12 hours after radiation. Changes in cell cycle were explored by flow cytometry at 0, 6, 12, 24, and 36 hours after radiation. Results： After X-ray radiation, human pancreatic carcinoma cell line （MIA PaCa-2） were swelling. With the increase of radiation dose （less than 10 Gy）, apoptotic necrosis and G2/M blockage of cell cycle was more obvious. When radiation dose was more than 10 Gy, the peak of apoptotic necrosis appeared early and obvious. The degree of DNA injury was most obvious when radiation dose was 10 Gyand was decreased when radiation dose was 17 Gy. When radiation dose was less than 10Gy, DNA ladder was single electrophoresis band. When radiation dose was 10Gy group, DNA ladder detection showed multiple typical ladder band. When radiation dose was more than 10Gy, vague irregular bands were observed. Conclusion： Different from conventional dose-fraction radiation, high dose per fraction causes oncotic necrosis as the main cell death type.

关 键 词：单次大剂量放射模式 MIA PaCa-2 胀亡 凋亡 放射损伤 

分 类 号：R735.9[医药卫生—肿瘤]