CARCINOGEN INDUCTION OF INFINITE LIFESPAN IN CELLS

由于癌症从根本上说是一个人类问题， 理解这个过程与人类物种有关。 研究 啮齿类动物细胞恶性转化的机制 体外已经优雅地进行，并允许详细的分析 这些物种的致癌过程。 不幸的是， 培养中的人类细胞的恶性转化并不 自发发生或作为致癌物治疗的结果， 尽管包括我们小组在内的许多调查人员进行了密集的工作。 近年来，关于人类细胞恶性转化的报道很少， 已经发表的试管似乎涉及到一个很大的元素， 机会 然而，现在可以诱导人类成纤维细胞 除了一种常见的表型变化外， 转化的啮齿动物成纤维细胞的特征。 的 无限寿命（UL）特性通常被称为 “不死”是从来没有见过的。 这可能是因为啮齿动物 成纤维细胞和人成纤维细胞是根本不同的， 也许这反映了它们的寿命 物种 正如提案中所讨论的，有理由相信 这不是真的。 更有可能的是 获得UL人成纤维细胞是细胞培养的人工产物。 因此，这一建议是一个全力以赴的努力，以发展的方法， 可重复地诱导UL人成纤维细胞。 与此同时， 三个二倍体UL人成纤维细胞系，唯一已知的是， 将被用来确定各种其他变化的作用， 恶性转化的多步骤过程。 使用来自正常人和来自 对于患有布鲁姆综合症和范科尼贫血的患者，我们会尝试 来诱导具有无限寿命的细胞。 为了做到这一点， 细胞在增加氧张力的条件下诱导 致染色体断裂效应 我们还将正常的成纤维细胞 对苯并（a）芘的反式7，8-二醇-9，10-环氧化物重复 因为叙利亚仓鼠成纤维细胞暴露于这种致癌物质 导致UL。 我们将选择这些系列的治疗人群， 使用避免代谢的条件， 衰老细胞和非衰老细胞之间的合作。 在进行上述实验的同时，我们将展示三个 已经获得无限寿命的成纤维细胞系 (HUT 11、HUT、12和LGIvmyc 1）与致癌物的接触， 诱导他们获得其余的系列， 肿瘤细胞相关特征， 确定哪种特征组合赋予了他们 形成肿瘤。 我们还将确定成纤维细胞是如何 与人类纤维瘤和低度恶性肿瘤不同， 正常细胞和纤维肉瘤衍生细胞，因为它们可能 代表了恶性肿瘤的中间阶段

Since cancer is fundamentally a human problem, it is critical to understand the process as related to the human species. Studies on the mechanisms of rodent cell malignant transformation in vitro have been elegantly carried out and allow detailed analysis of the process of carcinogenesis in these species. Unfortunately, the malignant transformation of human cells in culture does not occur spontaneously or as a result of carcinogen treatment, despite intensive work by many investigators, including our group. The few reports of the malignant transformation of human cells in vitro that have been published seem to involve a large element of chance. However, it is now possible to induce human fibroblasts to express all but one of the common phenotypic changes characteristic of the transformed rodent fibroblasts. The property of unlimited lifespan (UL) often referred to as "immortality" is never seen. This may be because rodent fibroblasts and human fibroblasts are fundamentally different, perhaps reflecting the great difference in lifespan of these species. As discussed in the proposal, there are reasons to believe that this is not true. It seems much more likely that the failure to obtain a UL human fibroblast is an artifact of cell culture. Therefore, this proposal is an all out effort to develop methods to reproducibly induce UL human fibroblasts. At the same time, three diploid UL human fibroblast cell lines, the only ones know to us, will be used to determine the role of various other changes in the multistepped process of malignant transformation. Using fibroblast cell lines derived from normal persons and from patients with Bloom's syndrome and Fanconi's anemia, we will try to induce cells with unlimited lifespans. To do so, we will grow the cells under conditions of increased oxygen tension to induce clastogenic effects. We will also expose normal fibroblasts repeatedly to the anti 7,8-diol-9,10-epoxide of benzo(a)pyrene because exposure of Syrian hamster fibroblasts to this carcinogen led to UL. We will select these series of treated populations for nonsenescing cells, using conditions that avoid metabolic cooperation between senescing and nonsenescing cells. While the above experiments are in progress we will expose three fibroblast cell lines that have already acquired unlimited lifespan (HUT 11, HUT, 12 and LGIvmyc1) to carcinogens in order to induce them to acquire the rest of the series of tumorcellrelated characteristics in a stepwise fashion and determine which combination of traits confers on them the ability to form tumors. We will also determine how fibroblasts derived from human fibromas and low grade maligancies differ from normal cells and from fibrosarcomaderived cells since they may represent intermediates on the path to malignancy.