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EVALUATION OF APOPTOSIS RELATED GENE AND MUTATION INDUCTION FATER IRRADIATION.

凋亡相关基因的评估和辐射诱导突变。

基本信息

批准号：
08671051
负责人：
SHIGEMATSU Naoyuki
金额：
$ 1.6万
依托单位：
KEIO University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08671051/
关键词：
Radiotherapy Heavy Ion Beam Mutation LET Apoptosis RBE

项目摘要

In order to evaluate the biological effectsu of heavy-ion beams and X-rays on cultured cells, we investigated the cell-killing effects and mutation induction at the hprt locus, at first. The cell-lines we used were Chinese hamster origin (V79), human ovarian cancer origin (RMG1), human breast cancer origin (MDA-MB231) and human esophageal cancer origine (TE24). Cells were cultured in monolayr condition and irradiated by X-rays (150kVp) or carbon beams (20keV/mu m, 80keV/mu m) or neon beam (80keV/mu m), and cell survivals were calculated by colony assay and the mutation frequencies at hprt locus were calculated from the numbers of colonies formed in media supplemented with 6-thioguanin. We obtained the following results at least in three cell lines (V79, RMG1 and MDA-MB231). (1) the heavy ion beams showed much more powerful cell-killing effects than X-rays and carbon beams with high LET showed more enhanced effects than low LET beams, (2) when the same LET level was used, carbon beam sh … More owed slightly higher cell-killing effect compared with neon beam, (3) extremely higher mutation frequency was observed for cells irradiated by the heavy ion beams compared with that irradiated by X-rays, (4) the mutation frequency was increased when the LET of carbon beam was increased, (5) the mutation frequency was less for neon than carbon when the same LET level was employed. We are getting almost the same results with TE24, but still more experiments will be needed with this cell-line.We also tried to evaluate the frequencies of apoptotic cells for these four cell-lines after irradiation by X-rays and heavy ion beams. Apoptotic cells were detected by Apo2.7 monoclonal antibody using the flow-cytometer. Apo2.7 is a PE labeled monoclonal antibody for the 7A6 antigen (protain of 38kD) which is appeared for the mitochondria membrain of apoptotic cells from eary stage of apoptosis. The detection ability of this method for the apoptotic cells were so sensitive that it was very difficult to get the best condition of experiment for each cell-line. This time, we could clearfy the indispensable condition of this nethod for these cell-lines irradiated by X-rays. We will analyze the frequencies of apoptotic cells after heavy ion beam irradiation under the obtained condition, and investigate the relationship with the cell-killing effects and the mutation induction effects. Less

为了评价重离子束和X射线对培养细胞的生物学效应，我们首先研究了hprt位点的细胞杀伤作用和突变诱导作用。我们使用的细胞系是中国仓鼠来源（V79）、人卵巢癌来源（RMG1）、人乳腺癌来源（MDA-MB231）和人食道癌来源（TE24）。将细胞在单层条件下培养，并用X射线（150kVp）或碳束（20keV/μm、80keV/μm）或氖束（80keV/μm）或氖束（80keV/μm）照射，通过菌落测定计算细胞存活率，并根据添加6-硫鸟嘌呤的培养基中形成的菌落数计算hprt位点的突变频率。我们至少在三种细胞系（V79、RMG1 和 MDA-MB231）中获得了以下结果。 (1)重离子束比X射线具有更强的细胞杀伤作用，高LET的碳束比低LET束具有更强的增强效果，(2)相同LET水平时，碳束比氖束具有略强的细胞杀伤作用，(3)与X射线相比，重离子束照射的细胞突变频率极高，(4)突变频率增加当碳束的LET增加时，(5)当采用相同的LET水平时，氖的突变频率低于碳。我们用 TE24 得到了几乎相同的结果，但仍需要对该细胞系进行更多实验。我们还尝试评估这四种细胞系在 X 射线和重离子束照射后的凋亡细胞频率。使用流式细胞仪通过Apo2.7单克隆抗体检测凋亡细胞。 Apo2.7是PE标记的针对7A6抗原（38kD蛋白）的单克隆抗体，7A6抗原出现在凋亡早期细胞的线粒体膜上。该方法对凋亡细胞的检测能力非常敏感，很难为每个细胞系获得最佳的实验条件。这次，我们可以明确这种方法对于X射线照射的细胞系的必备条件。我们将在所获得的条件下分析重离子束照射后细胞凋亡的频率，并研究其与细胞杀伤效果和突变诱导效果的关系。较少的