IN VITRO TRANSFORMATION OF HUMAN CELLS BY CARCINOGENS

尽管暴露于环境中会诱发人类肿瘤， 化学致癌物是有据可查的，我们已经表明，正常人 培养中的细胞很容易被这些致癌物质突变，没有人能够 为了可重复地定量人细胞在 化学致癌物培养。 能够执行的优点 这样的转换是：1）它将提供我们必须提供的最接近的模拟， 研究人类体内的化学致癌作用; 2）它将使我们能够直接 检验体细胞与细胞周期之间存在因果关系的假设 突变和细胞转化;和3）它可以作为基础， 这是识别潜在化学致癌物的重要系统。 因此，我们建议制定出建立这种体外 化学致癌系统，用于检测（如果可能，定量） 在培养的人细胞（成纤维细胞和上皮细胞）中转化， 考虑到已经证明的必要条件 成功转化动物细胞培养物。 使用人类细胞类型的群体，因为它们具有 与这些成功的动物细胞中的一个或多个相似的特征 我们将：1）将细胞暴露于直接作用的“终极”致癌物， 必要时使用重复剂量。 2)允许随后的细胞分裂， 以允许“固定和表达转化”。“3）识别 通过某些形态学和/或功能性鉴定， 特征，以及4）将这些与“候选人”的能力相关联 转化体”以在无胸腺裸鼠中产生肿瘤。 我们还将研究启动子对人类细胞增殖能力的影响。 转化.

Although the induction of tumors in human beings by exposure to environmental chemical carcinogens is well-documented and we have shown that normal human cells in culture are readily mutated by such carcinogens, no one has been able to reproducibly quantitate the frequency of transformation of human cells in culture with chemical carcinogens. The advantages of being able to carry out such transformations are: 1) it would provide the closest analog we have to studying human chemical carcinogenesis in vivo; 2) it would allow us to directly test the hypothesis that a causal relationship exists between somatic cell mutation and cell transformation; and 3) it could serve as the basis for an important system for the identification of potential chemical carcinogens. Therefore, we propose to work out methods required to establish such an in vitro chemical carcinogenesis system for detecting (and, if possible, quantitating) transformation in human cells (fibroblasts and epithelial) in culture, taking into consideration the conditions that have been demonstrated to be necessary for the successful transformation of animal cell cultures. Using populations of human cell types selected because they possess characteristics similar to those of one or more of these successful animal cell systems, we will: 1) expose the cells to direct-acting "ultimate" carcinogens, using repeated doses if necessary. 2) permit subsequent cell division in order to allow for "fixation and expression of transformation." 3) identify "candidate transformants" by certain morphological and/or functional caracteristics, and 4) correlate these with the ability of the "candidate transformants" to produce tumors in athymic nude mice. We will also examine the effect of promotors on the ability of human cells to be transformed.