Structural Basis of Multidrug resistance in Cancer

多药耐药性是治愈癌症的主要障碍，因为癌细胞对多种药物产生耐药性。 和无关的治疗化合物。多药耐药的一种机制是主动挤出 化疗药物从癌细胞通过ABC转运蛋白。ABCG 2是一种混杂的ABC转运蛋白 许多不相关的化合物。ABCG2的突变形式在多药耐药细胞中表达水平升高 多种来源的耐药癌症，包括成纤维细胞、乳腺癌、结肠癌、肺癌和卵巢癌。的机制 药物转运的机制尚不清楚，ABCG 2的每个结构域的功能既没有测试， 确认此外，没有ABCG 2的三维结构。具体目标如下： 提出了纠正这种情况：1）表征全长ABCG 2及其结构域。的活性 ABCG 2的每个结构域将使用测量细胞毒性、ATP酶活性、药物结合 和药物挤出。2)确定ABCG 2胞质结构域的三维结构。x射线 将解析揭示核苷酸与胞质结构域结合模式的结构。3)到 确定全长ABCG 2和结构域的三维结构。结构将得到解决的充分 ABCG2的长度和活性结构域。结构和活性数据的相关性将阐明 ABCG 2和同源转运蛋白的药物转运机制，从而引领新策略 用于开发针对多药耐药癌症的新型化学疗法。具体目标1和2是 具体目标3是为K01奖的第二阶段及以后提出的。K01 将为申请人提供受保护的时间来发展新技能，并将现有技能应用于癌症研究， 在她的导师的指导下，在Eppley研究所的刺激教育环境中。她 然后，我将准备好成功地竞争，并获得一个独立的终身职位，在癌症 research.

Multidrug resistance is a major obstacle to curing cancer because cancer cells become resistant to diverse and unrelated therapeutic compounds. A mechanism for multidrug resistance is the active extrusion of chemotherapeutic drugs from cancer cells by ABC transporters. ABCG2 is a promiscuous ABC transporter of many unrelated compounds. Mutant forms of ABCG2 are expressed in elevated levels in multidrug resistant cancers of diverse origins including fibroblasts, breast, colon, lung, and ovaries. The mechanisms of drug transport remain unclear and the functions of each domain of ABCG2 are neither tested nor confirmed. Furthermore, there are no 3-dimensional structures of ABCG2. The following specific aims are proposed to rectify this situation: 1) To characterize full length ABCG2 and its domains. The activity of each domain of ABCG2 will be tested using assays that measure cytotoxicity, ATPase activity, drug binding and drug extrusion. 2) To determine 3-dimensional structures of ABCG2's cytosolic domain. X-ray structures will be solved that reveal the mode of binding of nucleotides to the cytosolic domain. 3) To determine 3-dimensional structures of full length ABCG2 and domains. Structures will be solved of full length and active domains of ABCG2. The correlation of structural and activity data will clarify the mechanism of drug transport by ABCG2 and homologous transporters, thus spearheading new strategies for the development of novel chemotherapies for multidrug resistant cancer. Specific aims 1 and 2 are proposed for Phase I, while specific aim 3 is proposed for Phase II of the K01 award and beyond. The K01 will afford the applicant protected time to develop new skills and to apply existing skills to cancer research, with the guidance of her mentors, at the stimulating educational environment of the Eppley Institute. She will then be ready to successfully compete for and obtain an independent tenure track position in cancer research.