Altered Apoptotic Responses in Chemically-Resistant Mammalian Cell Variants

细胞程序性死亡是动物发育的正常组成部分，受特定基因产物的积极控制，是发生在胚胎和成人各种细胞中的事件。程序性细胞死亡或细胞凋亡可通过化学和物理处理在各种培养细胞类型中诱导。然而，我们对细胞凋亡的分子机制知之甚少。这部分是由于细胞凋亡的正调控因子和负调控因子尚不清楚，部分是由于凋亡信号通路中缺乏合适的突变体。本研究的目的是：a)从人类细胞系（HL-60）中分离出耐化学药的凋亡细胞变体，并将这些变体分类为互补群；B)识别与化学诱导的细胞凋亡的早期进展特异性相关的结构和生化上的连续细胞变化；d)表征导致蛋白酶活化的特定事件，以及凋亡细胞及其变体中蛋白质和DNA靶点的改变。这些研究将有助于构建细胞凋亡信号通路，深入了解细胞凋亡调控基因产物与细胞凋亡信号通路中特定事件的关系。细胞程序性死亡是动物发育过程中正常的一部分，受特定基因产物的积极控制，发生在胚胎和成人的各种细胞中。程序性细胞死亡或细胞凋亡可通过化学和物理处理在各种培养细胞类型中诱导。然而，我们对细胞凋亡的分子机制知之甚少。＊＊＊

96-30362 Wyche Programmed cell death is a normal part of animal development, is actively controlled by specific gene products, and is an event that occurs in various cells in the embryo and in adults. Programmed cell death, or apoptosis, can be induced in various cultured cell types by chemical and by physical treatment. Yet little is known about the molecular mechanism of apoptosis. This is partly caused by the fact that the positive and negative regulators of apoptosis are as yet unknown and partly to the lack of suitable mutants in the apoptotic signaling pathway. The objectives of this proposal are: a) isolation of chemically-resistant apoptosis cell variants from a human cell line (HL-60) and classification of the variants into complementation groups; b) identification of sequential cellular changes, structurally and biochemically, that are specifically associated with early progression of chemically-induced cell apoptosis; d) characterization of specific events leading to the activation of proteases as well as alterations in protein and DNA target sites in apoptotic cells and their variants. These studies should lead to the construction of the apoptotic signaling pathway and to insights into the relationship between apoptosis regulatory gene products and to specific events in the apoptotic signaling pathway. %%% Programmed cell death is a normal part of animal development, is actively controlled by specific gene products, and is an event that occurs in various cells in the embryo and in adults. Programmed cell death, or apoptosis, can be induced in various cultured cell types by chemical and by physical treatment. Yet little is known about the molecular mechanism of apoptosis. ***