GENETIC ANALYSIS OF THE MULTIPLE DRUG RESISTANCE PHENOTYPE IN TUMOR CELLS

肿瘤细胞多重耐药表型的遗传分析

• 批准号: 3808546
• 负责人: M M GOTTESMAN
• 金额: --
• 依托单位: DIVISION OF CANCER BIOLOGY AND DIAGNOSIS
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3808546
• 关键词: P glycoprotein; Retroviridae; antineoplastic antibiotics; antineoplastics; biological transport; bone marrow; cis platinum compound; complementary DNA; disease /disorder model; drug adverse effect; drug interactions; gene expression; gene therapy; genetically modified animals; hydropathy; intracellular transport; laboratory mouse; leukopenia; membrane channels; membrane permeability; membrane proteins; membrane transport proteins; molecular cloning; multidrug resistance; neoplasm /cancer chemotherapy; neoplasm /cancer genetics; neoplasm /cancer pharmacology; neoplastic cell; pharmacokinetics; tissue /cell culture; transfection; transposon /insertion element

The simultaneous resistance of cancer cells to many different anti-cancer drugs is the major impediment to successful chemotherapy of metastatic disease. An important mechanism of multidrug resistance is expression of P-glycoprotein, a 170,000 dalton energy-dependent drug efflux pump which removes natural product drugs from the cell. We have continued our studies of multidrug resistance by an analysis of the mechanism by which this pump removes drug from within the plasma membrane or from the cytoplasm. In an in vitro vesicle system, ATP has been shown to be the preferred energy source, and many of the drugs which are transported compete with each other for a single site or small number of sites on the transporter. Labeling sites for the P-glycoprotein inhibitor 3H-azidopine occur in both the amino and carboxy-terminus of the protein, and these two sites appear likely to make up the single channel through which the drugs move. Molecular manipulations have identified the first intracytoplasmic loop as a domain involved in drug recognition, which is distinct from the drug labeling sites identified with 3H-azidopine. We have also developed an MDR1 transgenic mouse whose bone marrow is protected from the cytotoxic effects of anti-cancer drugs by expression of P-glycoprotein. This model can be used to identify potent agents which inhibit the multidrug transporter in vivo, since these agents sensitize the transgenic mice to the leukopenia induced by chemotherapy. The MDR 1 cDNA can also be introduced into mouse bone marrow by retroviral infection. Such MDR1 retroviral vectors should be useful for gene therapy to protect bone marrow during cancer therapy and to introduce non-selectable genes into bone marrow. New in vitro models of resistance to VP-16 and cis-platinum, not involving the multidrug transporter, are under development.

癌细胞对多种不同抗癌药物的同时耐药性 药物是转移性肝癌化疗成功的主要障碍。 疾病 多药耐药的一个重要机制是表达 P-糖蛋白是一种170，000道尔顿的能量依赖性药物外排泵， 从细胞中清除天然产物药物。 我们继续 多药耐药的研究，通过分析的机制， 该泵将药物从质膜内或从 细胞质 在体外囊泡系统中，ATP已被证明是 首选的能源，以及许多被运输的药物 相互竞争一个单一的网站或少量的网站上， 传送器。 P-糖蛋白抑制剂的标记位点 3 H-叠氮嘌呤存在于蛋白质的氨基和羧基末端， 这两个地点似乎构成了一个通道， 药物移动的地方 分子操作已经确定了第一个 胞浆内环作为参与药物识别的结构域， 与用3 H-叠氮平鉴定的药物标记位点不同。 我们 还开发了一种MDR 1转基因小鼠，其骨髓 保护免受抗癌药物的细胞毒性作用， P-糖蛋白 该模型可用于识别有效的代理 其在体内抑制多药转运蛋白，因为这些药剂 使转基因小鼠对化疗引起的白细胞减少症敏感。 MDR 1cDNA也可以通过体外转染导入小鼠骨髓 逆转录病毒感染 这样的MDR 1逆转录病毒载体应可用于 基因治疗在癌症治疗期间保护骨髓， 将非选择性基因引入骨髓。 新的体外模型 对VP-16和顺铂耐药，不涉及多药 运输机正在开发中。