CARCINOGEN INDUCTION OF INFINITE LIFESPAN IN HUMAN CELLS

由于癌症从根本上说是一个人类问题，因此至关重要的是 理解这一过程与人类物种有关。研究 鼠类细胞恶性转化机制的研究 已经优雅地进行了体外培养，并允许进行详细的分析 这些物种的致癌过程。不幸的是， 人类细胞在培养中的恶性转化不会 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都在紧张地工作。 中国人细胞恶性转化的少数报道 已经发表的体外实验似乎涉及到大量的 机会来了。然而，现在有可能诱导人类成纤维细胞 来表达除了一种常见的表型变化之外的所有 转化的啮齿动物成纤维细胞的特征。这个 无限寿命(UL)财产通常被称为 “不朽”是从来没有见过的。这可能是因为啮齿动物 成纤维细胞和人类成纤维细胞是根本不同的， 或许反映了这些生物在寿命上的巨大差异 物种。正如提案中所讨论的，有理由相信 这不是真的。看起来更有可能的是失败 获得UL人成纤维细胞是细胞培养的产物。 因此，这项提议是一项全力开发方法的努力，以 可重复性诱导UL人成纤维细胞。同时， 三个二倍体UL人成纤维细胞系，唯一已知的 美国，将被用来确定各种其他变化在 多步骤的恶变过程。 使用来自正常人和来自 患有Bloom综合征和Fanconi贫血的患者，我们会尝试 来诱导无限寿命的细胞。要做到这一点，我们将发展 细胞在氧分压升高的条件下诱导 碎裂效应。我们还将展示正常的成纤维细胞 对苯并(A)芘的反7，8-二醇-9，10-环氧化物的反复作用 因为叙利亚仓鼠成纤维细胞暴露于这种致癌物质 导致了UL。我们将选择这些系列的治疗人群用于 非衰老细胞，使用避免新陈代谢的条件 衰老细胞和非衰老细胞之间的协同作用。 在上述实验进行期间，我们将公开三个 已经获得无限寿命的成纤维细胞系 (HUT 11、HUT 12和LGIVmyc1)以致癌物质 诱使他们获得系列的其余部分 循序渐进的肿瘤细胞相关特征和 确定哪种特征组合赋予他们这种能力 形成肿瘤。我们还将确定成纤维细胞是如何从 来自人类纤维瘤和低级别恶性肿瘤不同于 正常细胞和纤维肉瘤细胞，因为它们可能 代表着恶变之路上的中间人。

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.