Relationship between cellular radio-sensitivity and naked DNA damage in mammalian cells exposed to heavy ions  

作　　者：LI Wenjian ZHOU Guangming WANG Zhuanzi LI Qiang DANG Bingrong WANG Jufang 

机构地区：[1]Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China

出　　处：《Nuclear Science and Techniques》2009年第6期349-353,共5页核技术（英文）

基　　金：Supported by National Natural Science Foundation of China (Grant NO. 10875153)

摘　　要：The relationship between deoxyribonucleic acid (DNA) damage and the cell death induced by 12C ions irradiation was examined in four kinds of cells, Melanoma B16, cervical squamous carcinoma HeLa, Chinese hamster V79 and hepatoma SMMC-7721. Cell survival was determined by a colonogenic assay, and the sensitivity was described by D50 (the dose of radiation necessary to reduce the survival to 50%). For all cell lines, D50 ranged from 0.74 Gy to 3.85 Gy, among them B16 was the most radiosensitive to 12C ions, and V79 and HeLa cells had almost the same radio-sensitivity, SMMC-7721 was the last. The induction of deproteinized DNA double-strand breaks induced by 12C ions were measured by pulsed-field gel electrophoresis (PFGE), and the initial yield of the deproteinized DNA dsbs per unit dose was expressed as the DNA double break level (L). A linear dose-response curve was seen for initial DNA dsbs for all cell lines (slopes range from 0.40-0.98 (DSBs/100Mbp/Gy)). V79 was the steepest, B16 was the last. There was an inverse relationship between the initial DNA dsb and D50 if the B16 cell line was not considered, but there was no relativity even excludes the B16 cell line. The present results indicate that there is no relationship between cellular sensitivity and initial DNA dsb, even exclude the effects of chromatin structure.The relationship between deoxyribonucleic acid （DNA） damage and the cell death induced by ^12C ions irradiation was examined in four kinds of cells, Melanoma B 16, cervical squamous carcinoma HeLa, Chinese hamster V79 and hepatoma SMMC-7721. Cell survival was determined by a colonogenic assay, and the sensitivity was described by D50 （the dose of radiation necessary to reduce the survival to 50%）. For all cell lines, D50 ranged from 0.74 Gy to 3.85 Gy, among them B16 was the most radiosensitive to ^12C ions, and V79 and HeLa ceils had almost the same radio-sensitivity, SMMC-7721 was the last. The induction of deproteinized DNA double-strand breaks induced by ^12C ions were measured by pulsed-field gel electrophoresis （PFGE）, and the initial yield of the deproteinized DNA dsbs per unit dose was expressed as the DNA double break level （L）. A linear dose-response curve was seen for initial DNA dsbs for all cell lines （slopes range from 0.40-0.98 （DSBs/100Mbp/Gy））. V79 was the steepest, 1316 was the last. There was an inverse relationship between the initial DNA dsb and D50 if the B16 cell line was not considered, but there was no relativity even excludes the B16 cell line. The present results indicate that there is no relationship between cellular sensitivity and initial DNA dsb, even exclude the effects of chromatin structure.

关 键 词：哺乳动物细胞 DNA损伤 放射敏感性 重离子 DNA双链断裂 脉冲场凝胶电泳 无线 蜂窝 

分 类 号：Q78[生物学—分子生物学] Q523