GENETIC ANALYSIS OF THE MULTIDRUG RESISTANCE PHENOTYPE IN TUMOR CELLS

肿瘤细胞多药耐药表型的遗传分析

• 批准号: 5200967
• 负责人: I PASTAN
• 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/5200967
• 关键词: HTC cell; P glycoprotein; Saccharomyces cerevisiae; adenosine triphosphate; adenosinetriphosphatase; bone marrow; cis platinum compound; complementary DNA; fungal genetics; gene expression; genetic markers; laboratory mouse; membrane transport proteins; multidrug resistance; neoplasm /cancer chemotherapy; neoplasm /cancer genetics; neoplastic cell; nucleic acid sequence; phenotype; protein structure function; transfection /expression vector

We have been interested in defining the major mechanisms of simultaneous resistance of cancer cells to multiple chemotherapeutic agents. One major mechanism is expression of an energy-dependent efflux pump, termed P-glycoprotein (P-gp), or the multidrug transporter, encoded in humans by the MDR1 gene. The sequence of the MDR1 cDNA led to a model of the transporter as a pump with 12 transmembrane domains and 2 ATP sites; determination of the domains of P-gp responsible for substrate binding and coupling of ATPase activity to substrate transport are the major goals of our work. Model systems based on stable expression or transient expression of mutated P-gps have been developed to assay functional effects of these mutations on drug binding, drug-dependent ATPase, drug resistance and drug transport. The creation of expression vectors able to confer multidrug resistance and the demonstration that expression of the MDR1 gene in the bone marrow of mice leads to resistance to anti-cancer drugs have enabled the development of vectors for gene therapy of cancer and other genetic diseases in which P-gp serves as a dominant selectable marker; improvements on these vectors leading to trials in animal models and eventually in patients are another important goal of our research. We have also begun to explore the mechanism of multidrug resistance resulting from selection in cisplatin of hepatoma cells and the yeast Saccharomyces cerevisiae. Cisplatin-resistant hepatoma cells accumulate reduced amounts of cisplatin by a mechanism as yet to be determined, and at least two yeast genes associated with cisplatin resistance have been isolated.

我们一直对定义主要机制感兴趣 癌细胞同时对多种化疗药物产生耐药性 代理。 一个主要机制是能量依赖性的表达 外排泵，称为 P-糖蛋白 (P-gp)，或多药 转运蛋白，在人类中由 MDR1 基因编码。 的顺序为 MDR1 cDNA 构建了一个具有 12 个泵的转运蛋白模型 跨膜结构域和 2 个 ATP 位点；域的确定 P-gp 负责底物结合和 ATP 酶活性偶联 基质运输是我们工作的主要目标。 模型系统 基于突变P-gps的稳定表达或瞬时表达 已被开发来测定这些突变的功能影响 药物结合、药物依赖性 ATP 酶、耐药性和药物 运输。 表达载体的创建能够赋予 多药耐药性和 MDR1 表达的证明 小鼠骨髓中的基因导致抗癌抵抗 药物使得基因治疗载体的开发成为可能 癌症和其他以 P-gp 为主导的遗传疾病 选择标记；对这些载体的改进导致试验 动物模型以及最终的患者是另一个重要目标 我们的研究。 我们也开始探索其机制 肝癌顺铂选择导致的多药耐药 细胞和酿酒酵母。 顺铂耐药 肝癌细胞通过某种机制积累减少量的顺铂 尚未确定，至少有两个酵母基因与 已分离出顺铂耐药性。