ASSAYS OF TUMOR RESPONSE TO RADIOTHERAPY

放射治疗是现代癌症治疗的重要组成部分。 确定最可能从以下治疗中受益的患者 电离辐射可提高治愈率。我们建议 继续调查抗辐射物质存在的假说 和/或修复人类肿瘤中的熟练细胞可预测放射治疗 失败了。因此，我们将建立人类早期传代文化 头颈部癌和软组织活检的肿瘤细胞系 肉瘤来源于放射治疗前的患者。然后我们会研究 人肿瘤放射敏感性及放射损伤的修复 细胞，并将我们的体外研究结果与在 关于局部控制和总存活率的条款。我们的研究将包括：1) 100-1100cGy(3)剂量下存活的D0、n、D的测定 Logs细胞杀伤率)，200cGy射线下存活；2)亚致死损伤的测量 这些早期传代的指数增长培养中的修复(SLDR) 肿瘤细胞.潜在致命性损伤修复的测定 (PLDR)采用PLDR生存曲线(100-1100cGy0和24小时)。PLDR 单次给药后的时间和时间进程PLDR实验 高原阶段培养不同时间点的继代培养；3) DNA双链断裂的诱导和再连接的测定 第一代，成倍增长的人类头颈文化和 软组织肉瘤细胞系。放射生物学参数(S) 是放射治疗失败或成功的生物学基础？ 预测临床结果可能从我们的调查中浮现。

Radiotherapy is an important component of modern cancer treatment. Identification of patients most likely to benefit from treatment with ionizing radiation might improve the therapeutic ratio. We propose to continue to investigate the hypothesis that the presence of radioresistant and/or repair proficient cells in human tumors predicts radiotherapy failure. Therefore, we will establish early-passage cultures of human tumor cell lines from biopsies of head-and-neck carcinomas and soft-tissue sarcomas derived from patients prior to radiotherapy. We will then study the radiosensitivity and repair of radiation damage in these human tumor cells and correlate our in vitro findings with radiocurability measured in terms of local control and total survival. Our studies will include: 1) determination of D0, n, D derived from survival at doses of 100-1100 cGy (3 logs cell kill), survival at 200 cGy; 2) measurement of sublethal damage repair (SLDR) in exponentially-growing cultures of these early-passage tumor cells; determination of the repair of potentially lethal damage (PLDR) employing PLDR survival curves (100-1100 cGy) at 0 and 24 hrs. PLDR time and time course PLDR experiments following a single dose and subculture at various time points from plateau phase cultures; 3) measurement of the induction and rejoining of DNA double-strand breaks in first-passage, exponentially-growing cultures of human head-and-neck and soft-tissue sarcoma cell lines. The radiobiological parameter(s) that is(are) the biological basis of radiotherapy failure or success and predicts clinical outcome may emerge from our investigation.