Mechanistic Comparison of Cisplatin with Synthetic DNA Repair-Shielding Anticance

这项工作的目标是将我们最近的实验结果转化为 将对顺铂的抗肿瘤反应用于开发治疗顺铂抗性肿瘤的新型化合物。 该基金的早期工作发现了顺铂毒性的三种新的前瞻性机制：（1）其 DMA加合物吸引蛋白质，其中一些蛋白质在癌细胞中表达，阻断DMA修复;（2）其 DMA加合物“劫持”特异性HMG结构域转录因子远离其启动子，导致 某些基因的表达减少;和（3）错配修复蛋白结合顺铂加合物， 使细胞对药物敏感。基于上述发现，在本资助期内，我们 开发了几种具有潜在新型作用机制的新型抗癌候选药物-机制 受到顺铂的启发这些化合物中的主要候选物E27 a被设计为通过以下方式起作用： 可能与顺铂耐药卵巢癌的治疗相关的机制。E27 A是 双功能DMA破坏剂，可以在DMA中产生对DNA具有高亲和力的受损位点， 雌激素受体我们的调查发现，E27 a设计中包含的原则 包括顺铂DMA加合物结合和螯合对肿瘤重要的蛋白质的能力 成长和生存。这项建议有两个平行的目标。一个是进一步描述 负责我们的新药剂E27 A的细胞毒性和抗肿瘤作用的机制。二是 将其对卵巢癌的疗效与临床上使用的顺铂和相关化合物进行比较 使用或临床候选人。本研究的具体目标是：（1）综合 铂和E27 a的分子变体和放射性标记类似物，是结构-活性研究的工具; (2)为了在敏感和敏感的细胞中进行针对顺铂和顺铂同系物的比较细胞毒性研究， （3）雌激素受体表达与卵巢癌细胞凋亡的关系; 卵巢癌对E27 a的敏感性和这些癌细胞对顺铂的抗性;和（4） 比较E27 a与顺铂在人卵巢癌动物模型中的疗效。使用 卵巢癌的常规和遗传动物模型以及相关细胞系，我们计划确定 我们最近制造的分子在多大程度上发挥了我们预期的作用， 与癌症治疗的相关性。结合传统的（免疫化学，遗传）和最近的 (RNAi加速器质谱）方法。

The goal of the proposed work is to translate our recent experimental findings on the mechanisms of antitumor responses to cisplatin into the development of novel compounds to treat cisplatin-resistant tumors. Earlier work on this grant discovered three novel prospective mechanisms of toxicity for cisplatin: (1) its DMA adducts attract proteins, some of which are expressed in cancer cells, that block DMA repair; (2) its DMA adducts "hijack" specific HMG-domain transcription factors away from their promoters, resulting in diminished expression of certain genes; and (3) mismatch repair proteins bind cisplatin adducts and sensitize cells to the drug. Based on the aforementioned discoveries, in the current grant period, we have developed several novel anticancer candidates with potentially novel mechanisms of action - mechanisms inspired by cisplatin. The lead candidate among these compounds, E27a, was designed to act by mechanisms that may be relevant for the treatment of cisplatin-resistant ovarian cancers. E27a is a bifunctional DMAdamaging agent that can create damaged sites in DMAthat have high affinity for the estrogen receptor. Principles incorporated into the design of E27a that were uncovered by our investigations of cisplatin include the ability of cisplatin DMAadducts to bind and sequester proteins important to tumor growth and survival. This proposal has two parallel objectives. One is to delineate further the molecular mechanisms responsible for the cytotoxic and antitumor effects of our new agent, E27A. The second is to compare its efficacy against ovarian cancers with that of cisplatin and related compounds that are in clinical use or are clinical candidates. The specific objectives of the proposed research are:(1) to synthesize molecular variants and radiolabled analogs of platinum and E27a that are tools for structure-activity studies; (2) to perform comparative cytotoxicity studies against cisplatin and cisplatin homologues in sensitive and resistant ovarian cancer cells; (3) to determine the relationship between estrogen receptor expression and sensitivity of ovarian cancers to E27a and the resistance of those cancer cells to cisplatin; and (4) to compare the efficacy of E27a to that of cisplatin in animal models of human ovarian cancer. Using conventional and genetic animal models for ovarian cancer, and relevant cell lines, we plan to determine to what extent the molecules we have recently made work the mechanisms that we intended and to determine their relevance to cancer treatment. A combination of traditional (immunochemical, genetic) and recent (RNAi, accelerator mass spectrometry) methods will be used.