Understanding Cisplatin Resistance Mediated by a Copper Efflux Protein

描述(申请人提供)：顺铂是一种广泛使用的抗癌药物，但由于固有和获得性细胞耐药性，其疗效有限。最近的研究表明，铜稳态蛋白，特别是铜转运泵和伴侣蛋白，可能参与顺铂耐药。这种关系的细节还没有完全弄清楚。这项拟议的研究将研究顺铂与分泌途径铜泵ATP7B(威尔逊病蛋白)和人类铜伴侣蛋白Atox1的调控铜结合结构域(MBDS)之间的相互作用。初步数据表明，顺铂可以直接结合这些蛋白，所有这些蛋白都有一个共同的折叠，并通过保守的半胱氨酸基序结合铜(I)。随后的实验将确定产生稳定和均匀的顺铂-蛋白质加合物的条件，确定顺铂结合的化学计量比和铂结合部位的性质及其对这些蛋白质整体结构的影响。对不太复杂的ATP7B同源物，Archaeoglobus fulgidus Copa的研究，将阐明顺铂与MBDS相互作用对铜结合、ATP水解和离子转运的功能后果。这项工作中获得的信息将提供顺铂和铜转运蛋白之间相互作用的分子水平表征，并可能影响新治疗方法的开发。 公共卫生相关性：该项目将在分子水平上表征顺铂和铜转运体之间的相互作用。顺铂是一种广泛用于抗癌的处方药。所获得的信息将为铜稳态机制介导的耐药机制提供深入的见解，并可能影响新治疗方法的发展。

DESCRIPTION (provided by applicant): Cisplatin is a widely used anticancer drug but its efficacy is limited due to intrinsic and acquired cellular resistance. Recent studies indicate that copper homeostatic proteins, particularly copper transport pumps and chaperones, may mediate cisplatin resistance. The details of this relationship are not fully understood. The proposed study will examine the interaction between cisplatin and regulatory copper binding domains (MBDs) from the secretory pathway copper pump ATP7B (the Wilson disease protein) and the human copper chaperone Atox1. Preliminary data indicate that cisplatin can directly bind these proteins, all of which share a common fold and bind Cu(I) via conserved cysteine motifs. Subsequent experiments will identify conditions that produce stable and homogenous cisplatin-protein adducts, determine the stoichiometry of cisplatin binding and the nature of the platinum binding site as well as its effect on the overall structure of these proteins. Studies with a less complex ATP7B homolog, Archaeoglobus fulgidus CopA, will elucidate the functional consequences of cisplatin interaction with MBDs for copper binding, ATP hydrolysis, and ion transport. The information gained in this work will provide molecular level characterization of the interaction between cisplatin and copper transporters and could impact the development of new therapeutic approaches. PUBLIC HEALTH RELEVANCE: This project will result in molecular level characterization of the interaction between cisplatin, a widely prescribed anticancer drug, and copper transporters. The information gained will provide insight into the mechanism of drug resistance mediated by copper homeostasis machinery and could impact the development of new therapeutic approaches.