BIOCHEMICAL AND MECHANSIMS OF ACTION OF STUDIES WITH

根据本主协议发布的任何主协议命令的目标 协议将确定可能的行动机制(S) 开发中值得关注的潜在抗肿瘤药物 治疗计划(DTP)。大多数待研究的化合物将 已被DTP鉴定为体外培养的人肿瘤细胞系。 那些表现出特定差异的细胞毒性和/或生长的化合物 将考虑抑制效果以进行进一步评估。澄清 这类制剂的生化作用机制将被用来帮助 确定化合物开发的优先事项，以进行临床试验。化合物 也可以根据其选择进行机械评估 抗转移、光敏或放射增敏活性。因此， 进行的特定生化研究可能因化合物不同而大不相同 化合物。尽可能进行机械化的评估 使用来自体外筛选的细胞。研究可通过以下方式进行 培养细胞、细胞提取物、纯化的细胞成分和/或 完整的动物和孤立的组织。特定的生化效应将被 评估可能包括诱导DNA损伤、RNA扰动 处理、核苷酸池大小的变化、DNA结合、抑制 特定的细胞酶(例如，DNA聚合酶、底物酶和甲基酶； 从新合成嘌呤和嘧啶的酶；抢救酶； 拓扑异构酶I和II；修复酶)，抑制大分子 合成，对微管蛋白和有丝分裂纺锤体的影响，游离中的变化 自由基的形成及其与细胞膜成分的相互作用 蛋白激酶C、G蛋白和其他参与信号传递的受体 转导、生长调节、分化和癌基因表达。

The objective of any Master Agreement Orders issued under this Master Agreement will be to determine the probable mechanism(s) of action of potential antitumor agents which are of interest to the Developmental Therapeutics Program (DTP). The majority of compounds to be studies will have been identified by the DTP in vitro human tumor cell line screen. Those compounds demonstrating specific differential cytotoxic and/or growth inhibitory effects will be considered for further evaluation. Elucidation of the biochemical mechanism of action of such agents will be used to help set priorities for development of compounds to clinical trial. Compounds may also be selected for mechanistic evaluation on the basis of their antimetastatic, photosensitizing or radiosensitizing activities. Thus, the specific biochemical studies performed may vary greatly from compound to compound. Mechanistic evaluations will be conducted wherever possible using cell lies from the in vitro screen. Studies may be performed with cultured cells, cellular extracts, purified cellular components, and/or intact animals and isolated tissues. Specific biochemical effects to be evaluated may include induction of DNA damage, perturbation of RNA processing, changes in nucleotide pool sizes, DNA binding, inhibition of specific cellular enzymes (e.g., DNA polymerases, primases, and methylases; enzymes of de novo purine and pyrimidine synthesis; salvage enzymes; topoisomerases I and II; repair enzymes), inhibition of macromolecular synthesis, effects on tubulin and mitotic spindle, alterations in free radical formation and interactions with cell membrane components such as protein kinase C, G proteins and other receptors involved in signal transduction, growth regulation, differentiation, and oncogene expression.