CELL CYCLE TARGETS FOR ANTICANCER DRUGS

直到最近，细胞周期的蛋白质机制和病因学 人类癌症的风险被认为是单独的话题。然而，壮观的 S在识别驱动分子方面取得了进展 并调节细胞周期引擎的活动。随着这一增长 在对细胞分裂的基本过程的理解中 意识到细胞周期调节的紊乱可能起到至关重要的作用 在不受控制的生长和内在基因组中的作用 肿瘤细胞的不稳定性。细胞周期引擎的中心组件 是细胞周期蛋白及其相关的细胞周期蛋白依赖性蛋白激酶(CDK)。这个 细胞周期研究计划揭示了一系列酶 为新型抗癌药物的开发提供了良好的靶点。 这个项目的总体目标是检验这样一个假设 针对细胞周期机制特定成分的药物 将作为化疗药物有效地治疗人类 癌症。为这些药物发现选择的最初靶标酶 努力是CDC25磷酸酶和细胞周期蛋白D相关蛋白 激酶、CDK4。细胞周期蛋白D-CDK4复合体调节细胞周期的一个关键步骤 细胞周期进程：G1期细胞进入S的承诺- 阶段，因此，决定进行有丝分裂。相比之下， CDC25磷酸酶在细胞周期的后期作为一种 激活有丝分裂的cdc2激酶的基本触发器。vbl.使用 中国传统和其他药用植物，细菌和真菌 发酵液和基于天然产物的组合库 作为新的化学结构的来源，我们将追求以下几点 具体目标：(1)实施基于多井的筛查方法 CDC25磷酸酶活性抑制剂，以及(2)开发和放置 蛋白激酶抑制剂的在线大容量筛选 细胞周期蛋白D-CDK4复合体的活性。已确定的这些抑制物 细胞周期目标将在#年接受机械性评估 我们实验室的实验模型系统，并将进行测试 我们的核心成分具有临床相关的抗肿瘤活性 药物发现小组。 这个核心的目标是从化合物中识别 在生化靶标屏幕上显示活性的那些化合物 对人类肿瘤具有显著的生长抑制活性 体外培养的细胞。此信息将用于确定 化合物需要化学修饰以提高细胞的生物利用度 等，哪些化合物是由Core C.We进行体内测试的 将常规使用7个人类肿瘤细胞系组成的小组，其中包括2个 乳腺、2个结肠、2个前列腺、1个卵巢和1个白血病细胞系。这 将使我们能够将毒品活动与一般情况下的 难治的人类实体肿瘤类型和一般敏感的人类 肿瘤类型(白血病)。该小组包括人类实体肿瘤，它将 作为异种移植物在体内进行研究。我们也有可用的面板 低传代人类原代肿瘤细胞系，包括乳腺和 前列腺和细胞被设计为过度表达感兴趣的靶点 专门的筛查。将对铅进行药代动力学研究 帮助其临床前开发并提供信息的化合物 用于化学修饰以提高生物活性。

Until recently, the protein machinery of the cell cycle and the etiology of human cancer were considered separate topics. However, spectacular progress s been made in the identification of the molecules that drive and modulate the activity of the cell-cycle engine. With this increase in understanding of the fundamental process of cell division has come the realization that derangements in cell-cycle regulators may play crucial roles in both the uncontrolled growth and the intrinsic genomic instability of tumor cells. Central components of the cell-cycle engine are the cyclins and their associated cyclin-dependent kinases (cdks). The program in cell-cycle research has revealed a series of enzymes that serve as promising targets for the development of novel anticancer drugs. The overall objective of this program is to test the hypothesis that drugs targeted against specific components of the cell-cycle machinery will be effective as chemotherapeutic agents in the treatment of human cancer. The initial target enzymes selected for these drug discovery efforts are the cdc25 phosphatase and the cyclin D-associated protein kinase, cdk4. The cyclin D-cdk4 complex regulates a critical step in cell-cycle progression: the commitment of the G1-phase cell to enter S- phase, and, consequently, the decision to undergo mitosis. In contrast, the cdc25 phosphatase functions at a later point in the cell cycle as an essential trigger for the activation of the mitotic cdc2 kinase. Using Chinese traditional and other medicinal plants, bacterial and fungal fermentation broths, and natural product-based combinatorial libraries as sources of novel chemical structures, we will pursue the following specific aims: (1) to implement a multi-well-based screening assay for inhibitors of cdc25 phosphatase activity, and (2) to develop and place on-line a high-volume screen for inhibitors of the protein kinase activity of the cyclin D-cdk4 complex. Identified inhibitors of these cell-cycle targets will be subjected to mechanistic evaluations in experimental model systems in our laboratory, and will be tested for clinically-relevant anti-tumor activities by the core components of our drug discovery group. The objectives of this Core are to identify, from among compounds exhibiting activity in the biochemical target screens, those compounds that possess significant growth inhibitory activity against human tumor cells in vitro. This information will be used to determine which compounds require chemical modification to improve cell bioavailablity etc., and which compounds are taken for in vivo testing by Core C. We will routinely use a panel of 7 human tumor cell lines that include 2 breast, 2 colon, 2 prostate, an ovarian and a leukemia cell line. This will allow us to compare drug activity with a panel of generally intractable human solid tumor types and a generally responsive human tumor type (leukemia). The panel includes human solid tumors that will be studied as xenografts in vivo in Core C. We also have available panels of low passage human primary tumor cell lines, including breast and prostate, and cells engineered to overexpress the target of interest for specialized screening. Pharmacokinetic studies will be done on lead compounds to aid their preclinical development and to provide information for chemical modification to improve biological activity.