MECHANISMS OF PROGRAMMED CELL DEATH IN CHEMOTHERAPY

拟议研究的目标是确定程序化的作用， 化疗药物作用中的细胞死亡，从而鉴定生化和 使细胞易受或保护细胞不受核酸内切酶影响的代谢因子 DNA损伤后的激活程序性细胞死亡或凋亡， 通过形态学和生物化学特征与坏死区分， 并且通常发生在胎儿发育、内分泌萎缩期间， 这是细胞免疫的结果。 细胞凋亡的标志是 染色质被内源性Ca ~（++）切割成寡核小体片段 /Mg++依赖性核酸内切酶。 最近的证据表明， 化疗药物在损伤间期细胞的DNA时可能引发 程序性细胞死亡，以及使用 2-氯-2 '-脱氧腺苷（CdA）支持慢性胰腺炎的这种机制。 淋巴细胞白血病（CLL）细胞。 然而，人们对此知之甚少。 Ca++通量、大分子合成或ADP-核糖基化的要求 在通过DNA损伤诱导经历凋亡的靶细胞中 化疗药物 该研究计划侧重于两个目标细胞 研究化疗中程序性细胞死亡的模型系统：（i）CLL和 作为恶性、非分裂细胞模型的毛细胞白血病，和（ii） 正常血液单核细胞，具有吞噬和吞噬功能的非分裂细胞模型， 分泌功能有助于自身免疫性疾病的发病机制 紊乱 靶向CLL和毛细胞白血病细胞和单核细胞将 在体外暴露于CdA和其他已知的化疗药物， 造成DNA损伤。 时间进程测量将由DNA链 断裂和寡核小体DNA片段化，后者通过方法 通过电泳后的可视化来观察片段释放。 还将测量NAD代谢的扰动，并且具体 调节Ca++流量、大分子合成和ADP-核糖基化 将被执行，以确定关键的生化途径， 从DNA链断裂到程序性细胞死亡的转变。 CdA是 在这个研究所的临床试验中， 淋巴恶性肿瘤和类风湿性关节炎。 研究计划 提供了一个独特的机会，以补充体外生化分析， 用流式细胞术研究检测同一靶细胞中的凋亡 在体内CdA处理期间的群体。 除了临床 这种组合方法的相关性，对生物化学的理解 程序性细胞死亡的机制应该为 抗癌和免疫抑制治疗的新策略。

The goal of the proposed research is to define the role of programmed cell death in chemotherapy drug action, so as to identify biochemical and metabolic factors that predispose or protect cells from endonuclease activation after DNA damage. programmed cell death, or apoptosis, is distinguishable from necrosis by morphologic and biochemical features, and typically occurs during fetal development, endocrine atrophy, and as a consequence of cell mediated immunity. The hallmark of apoptosis is chromatin cleavage into oligonucleosomal fragments by an endogenous Ca++ /Mg++dependent endonuclease. Recent evidence suggests that certain chemotherapy drugs at damage the DNA of interphase cells may trigger programmed cell death, and preliminary experiments using 2-chloro-2'-deoxyadenosine (CdA) support such a mechanism in chronic lymphocytic leukemia (CLL) cells. However, little is known about the requirements for Ca++ flux, macromolecular synthesis, or ADP-ribosylation in target cells induced to undergo apoptosis by DNA-damaging chemotherapeutic drugs. The Research Plan focuses on two target cell model systems to study programmed cell death in chemotherapy: (i) CLL and hairy cell leukemia as models of malignant, nondividing cells, and (ii) normal blood monocytes, a model of non-dividing cells with phagocytic and secretory functions contribute to the pathogenesis of autoimmune disorders. Target CLL and hairy cell leukemia cells and monocytes will be exposed in vitro to CdA and to other chemotherapy agents known to cause DNA damage. Time-course measurements will be made of DNA strand breaks and of oligonucleosomal DNA fragmentation, the latter by methods of fragment release and by visualization after electrophoresis. Perturbations in NAD metabolism will also be measured, and specific modulation of Ca++ flux, macromolecular synthesis, and ADP-ribosylation will be performed to determine critical biochemical pathways that govern the transition from DNA strand breaks to programmed cell death. CdA is in clinical trial at this institute for the treatments of chronic lymphoid malignancies and for rheumatoid arthritis. The research plan presents a unique opportunity to complement in vitro biochemical analyses with flow cytometric studies to detect apoptosis in the same target cell populations during CdA treatment in vivo. In addition to the clinical relevance of this combined approach, an understanding of biochemical mechanisms in programmed cell death should provide an important basis for novel strategies for anticancer and immunosuppressive therapy.