RESPONSE OF TUMOR CELLS TO HEAVY IONS

本研究的目的是确定以下因素的相对重要性： 各种细胞过程影响肿瘤对稀疏和 高度电离辐射。 这是通过使用 良好表征的动物肿瘤系统（WAG/Rij中的R-1肉瘤） 大鼠）。 从重带电粒子辐射的反应可在 Berkeley Bevalac与225 kVp X射线的响应进行了比较。 这些研究旨在提供关于 以下细胞过程中照射肿瘤：再生，修复 潜在的致命性损伤，细胞阶段特异性存活率和 复氧 再增殖的研究是通过测量 通过肿瘤切除测定的克隆形成细胞与时间的关系。 修复 潜在的致命伤害是通过药物的添加来衡量的 β-ara-A在辐射后的一系列时间。 细胞时相特异性 通过在肿瘤后引入Hoescht染色剂33342来测量存活率。 切除细胞群并将其分选为G1、S和G2+M级分， 流式细胞仪。 通过切除试验测量再氧合 法 收集的数据将用于进一步开发细胞动力学模型， 高和低LET辐射照射后的肿瘤体积反应。 该项目将提供一个相对的了解 这些过程在肿瘤反应中的重要性。 此信息将 对目前正在进行的重带电粒子放射治疗计划有用， 在贝伐拉克重离子加速器上进行。

The objective of this research is to determine the relative importance of various cellular processes in affecting tumor response to both sparsely and highly ionizing radiation. This is accomplished by using a well-characterized animal tumor system (the R-1 sarcoma in the WAG/Rij rat). The response from heavy charged particle radiation available at the Berkeley Bevalac is compared with the response from 225-kVp X rays. The studies are designed to provide information on the time course of the following cellular processes in irradiated tumors: repopulation, repair of potentially lethal damage, cell phase-specific survival and rates of reoxygenation. Repopulation is studied by measuring the fraction of clonogenic cells versus time by means of the tumor excision assay. Repair of potentially lethal damage is measured by the addition of the drug Beta-ara-A at a series of times postirradiation. Cell phase-specific survival is measured by introducing the Hoescht stain 33342 after tumor excision and sorting the cell population into G1, S and G2+M fractions with a FACS flow cytometer. Reoxygenation is measured via the excision assay method. The data gathered will be used to further develop a cell-kinetic model of tumor volume response after irradiation with high- and low-LET radiation. This project will provide an increased understanding of the relative importance of these processes in tumor response. This information will be useful to the heavy-charged particle radiotherapy program presently being conducted at the Bevalac heavy-ion accelerator.