Anticancer drug resistance studies using Dictyostelium

使用盘基网柄菌进行抗癌耐药性研究

• 批准号: 6478374
• 负责人: STEPHEN ALEXANDER
• 金额: $ 14.5万
• 依托单位: UNIVERSITY OF MISSOURI-COLUMBIA
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-01 至 2004-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6478374
• 关键词: Dictyostelium; antineoplastics; carboplatin; chlorambucil; cyclophosphamide; drug resistance; genetic library; microorganism genetics; mutant; tirapazamine; transposon /insertion element

Human tumors frequently develop resistance to many of the widely used chemotherapeutic agents. Many different mechanisms have been proposed for the molecular basis of this resistance. Studies on drug resistance in tumor cells have often focused on the mechanism of action of the drug, and looked for resistance due to altered drug concentration in the cell, different models of drug inactivation or altered damage repair. As such, other pathways that may be involved with the cellular cytotoxic response to individual drugs have been overlooked. We propose to use the cellular slime mold Dictyostelium discoideum in an unbiased approach to identify novel molecular targets that can be modulated to increase sensitivity of tumor cells to chemotherapeutic drugs. The genes and pathways of Dictyostelium are highly conserved with those of humans, and molecular genetic methods are well developed for this organism. Our preliminary system on cisplatin resistance resulted in the identification of 6 genes. Significantly, none of these had been previously associated with cisplatin, and each represents a potential new target for therapy. The goal of the present study is to demonstrate the general utility of this system and to show that it can be applied to the understanding of resistance to other drugs. We have focused on four classes of DNA damaging drugs that damage DNA by different mechanisms. These include: both intra- and inter-strand crosslinkers, monoalkylators, and oxygen radicals. We will 1) create a comprehensive Dictyostelium insertional mutant library, 2) isolate mutants resistant to drugs of each of the four classes and identify the cognate genes, and 3) test the mutants for cross-resistance to the other drugs. These studies will identify new mechanisms for drug resistance and new targets for chemotherapeutic intervention which can subsequently be validated in human cells.

人类肿瘤经常对许多广泛使用的化疗药物产生耐药性。对于这种耐药性的分子基础，已经提出了许多不同的机制。对肿瘤细胞耐药的研究往往集中在药物的作用机制上，寻找细胞内药物浓度改变、不同药物失活模式或损伤修复改变所导致的耐药。因此，可能与细胞对单个药物的细胞毒性反应有关的其他途径被忽视了。我们建议以一种无偏倚的方法使用细胞黏菌盘基钢霉来鉴定新的分子靶点，这些靶点可以调节以增加肿瘤细胞对化疗药物的敏感性。盘基ostelum的基因和途径与人类高度保守，分子遗传学方法也很发达。我们对顺铂耐药的初步系统鉴定出6个基因。值得注意的是，这些以前都没有与顺铂相关，每一个都代表了一个潜在的新治疗靶点。本研究的目的是证明该系统的一般效用，并表明它可以应用于了解对其他药物的耐药性。我们专注于四类DNA损伤药物，它们通过不同的机制损伤DNA。这些包括：链内和链间交联剂、单烷基化物和氧自由基。我们将建立一个全面的盘基骨菌插入突变文库，2)分离四类药物的抗性突变体并鉴定同源基因，3)测试突变体对其他药物的交叉抗性。这些研究将确定耐药性的新机制和化疗干预的新靶点，随后可在人类细胞中进行验证。