RADIOBIOLOGICAL STUDIES OF HUMAN HYBRID CELL LINES

拟议研究的长期目标有几个。第一 是为了进一步了解植物的遗传控制。 人类细胞的辐射敏感性以及基因如何改变 伴发肿瘤转化可能影响放射敏感性。这个 第二个是确定辐射诱导的基因变化与 人类细胞的肿瘤性转化。三是获取 与辐射诱发的各个方面有关的定量信息 人源性细胞系的肿瘤转化。医学部 拟议研究的意义主要是在以下领域 辐射致癌和放射治疗。 为达致这些长远目标，我们会继续进行研究，包括 具有良好特征的非致瘤和致瘤人类细胞杂交 细胞系(HeLa x皮肤成纤维细胞)。此外，我们还将发起新的 人微细胞杂交系的研究(HeLa+单拷贝 人皮肤成纤维细胞染色体，最初的11号染色体已经 显示可抑制HeLa细胞的致瘤性)。 拟议资助期的具体目标的理由是 根据我们到目前为止的研究。这些目标包括(1)检查细胞 辐射敏感性的周期依赖性与DNA损伤的诱导和修复 非致瘤和致瘤的杂交细胞，(2)检查 PLDR和SLDR在细胞存活和肿瘤中的作用 分步化疗对非致瘤细胞的转化作用 低剂量率辐射和(3)分离和表征 辐射诱导的肿瘤细胞的特性(包括检测丢失 肿瘤抑制基因)。标准方法以及 在P.I.的实验室中开发或正在开发 将使用联合侦探。细胞存活率将通过集落形成来评估 碱性和中性洗脱对DNA的损伤能力；肿瘤 免疫过氧化物酶分析转化肿瘤细胞的表达 相关抗原，通过RFLP分析抑制基因的丢失，以及通过 注射到裸鼠体内时细胞生长肿瘤的能力。

The long term objectives of the proposed research are several. The first is to gain further understanding of the genetic control of the radiosensitivity of human cells and how the genetic changes which accompany neoplastic transformation may effect radiosensitivity. The second is to determine radiation-induced genetic changes associated with the neoplastic transformation of human cells. The third is to obtain quantitative information relating to various aspects of radiation-induced neoplastic transformation of human derived cell lines. The medical significance of the proposed research is principally to the fields of radiation carcinogenesis and radiation therapy. To approach these long term objectives, we will continue our studies with well characterized non-tumorigenic and tumorigenic human cell hybrid lines (HeLa x skin fibroblast). Furthermore, we will initiate new studies with human microcell hybrid lines (HeLa plus a single copy of a human skin fibroblast chromosome, initially chromosome 11 which has been shown to suppress the tumorigenicity of HeLa cells). The rationale for the Specific Aims for the proposed funding period is based on our studies to date. These aims include (1) examining the cell cycle dependency of radiosensitivity and DNA damage induction and repair of both non-tumorigenic and tumorigenic hybrid cells, (2) examining contribution of PLDR and SLDR to cell survival and neoplastic transformation for non-tumorigenic cells treated with fractionated and low dose-rate radiation and (3) isolating and characterizing various properties radiation-induced neoplastic cells (including probing for loss of tumor-suppressor gene). Standard methodologies as well as those either developed or being developed in the laboratories of the P.I. and Co-P.I. will be used. Cell survival will be assessed by colony forming ability, DNA damage by alkali and neutral elution; neoplastic transformation by immunoperoxidase assay of expression of tumor associated antigen, by loss of suppressor gene by RFLP analysis, and by ability of cells to grow tumors when injected into nude mice.