Role of the Oxidative Stress Pathway in Drug Resistance

氧化应激途径在耐药性中的作用

• 批准号: 6884884
• 负责人: RANDY S STRICH
• 金额: $ 10.69万
• 依托单位: RESEARCH INST OF FOX CHASE CAN CTR
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-05-01 至 2005-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6884884
• 关键词: Saccharomyces cerevisiae; antineoplastics; biological signal transduction; cell line; cisplatin; cyclins; drug resistance; etoposide; fluorouracil; free radical oxygen; gene environment interaction; gene expression; gene targeting; genetic regulation; genetic transcription; human genetic material tag; methotrexate; microarray technology; mitomycin C; neoplasm /cancer chemotherapy; neoplastic cell; oxidative stress; phosphatidylinositols; phospholipase C; tissue /cell culture

DESCRIPTION (provided by applicant)Cellular resistance to anti-cancer agents is the predominant reason why chemotherapy regimens fail to eradicate disseminated malignancies. Therefore, elucidating the resistance mechanisms is of great importance for improving patient outcome. Several mechanisms for drug resistance have been identified including elevated drug pump activity and p53 mutation. In addition, the drug sensitivity of many tumors is influenced by induction of the stress response pathway. Moreover, the pathway that responds to reactive oxygen species (ROS) appears to be of singular importance for influencing drug sensitivity. However, the molecular mechanisms underlying the role of the ROS pathway in altering the drug response are largely unknown. The long-term goal of this proposal is to fully describe the ROS response system and determine how this pathway influences drug sensitivity in both normal and transformed cells. Toward this goal, we have chosen to study the relationship between the oxidative stress pathway and drug response in the budding yeast S. cerevisiae. Previous studies from this laboratory have identified two critical regulators that control both the oxidative stress-induced signal transduction pathway and gene expression. Ume3p is the yeast C-type cyclin that, rather than control the cell cycle, represses the transcription of several stress response genes. To relieve this repression, Ume3p is destroyed in cells exposed to oxidative stress. This destruction requires the conserved signaling molecule phosphatidylinositol-specific phospholipase C (PLC1). The importance of Plc1p-directed destruction of Ume3p is underscored by the finding that deleting the cyclin can rescue plc1 mutants from stress-induced cell death. The conservation of this pathway is supported by two findings. First, Plc1p is most similar to mammalian Plc-gamma, which also transduces an oxidative stress signal. In addition, the human cyclin C is also destroyed in response to stress in both human and yeast cells. The proposal combines the powerful genetic and molecular tools available in yeast to dissect the oxidative stress signaling pathway and determine its nuclear targets. We will combine our genetic system with microarray analysis to pinpoint genes whose expression is essential for viability in response to ROS. Finally, these genes will be ectopically activated or deleted in both yeast and human cells to determine their role in drug susceptibility or resistance.

描述（由申请人提供）细胞对抗癌药物的耐药性是化疗方案无法根除播散性恶性肿瘤的主要原因。因此，阐明耐药机制对于改善患者预后具有重要意义。已经确定了几种耐药机制，包括药物泵活性升高和 p53 突变。此外，许多肿瘤的药物敏感性受到应激反应途径诱导的影响。此外，响应活性氧（ROS）的途径似乎对于影响药物敏感性具有特殊的重要性。然而，ROS 途径在改变药物反应中的作用的分子机制在很大程度上尚不清楚。该提案的长期目标是全面描述 ROS 反应系统，并确定该途径如何影响正常细胞和转化细胞的药物敏感性。为了实现这一目标，我们选择研究芽殖酵母酿酒酵母中氧化应激途径与药物反应之间的关系。该实验室之前的研究已经确定了两个控制氧化应激诱导的信号转导途径和基因表达的关键调节因子。 Ume3p 是酵母 C 型细胞周期蛋白，它不控制细胞周期，而是抑制多个应激反应基因的转录。为了缓解这种抑制，暴露于氧化应激的细胞中的 Ume3p 被破坏。这种破坏需要保守的信号分子磷脂酰肌醇特异性磷脂酶 C (PLC1)。删除细胞周期蛋白可以将 plc1 突变体从应激诱导的细胞死亡中拯救出来，这一发现强调了 Plc1p 定向破坏 Ume3p 的重要性。该途径的保护得到了两项发现的支持。首先，Plc1p 与哺乳动物 Plc-gamma 最相似，后者也能转导氧化应激信号。此外，人类和酵母细胞中的细胞周期蛋白 C 也会因应激反应而被破坏。该提案结合了酵母中强大的遗传和分子工具来剖析氧化应激信号通路并确定其核靶点。我们将把我们的遗传系统与微阵列分析相结合，以查明其表达对于 ROS 反应活力至关重要的基因。最后，这些基因将在酵母和人类细胞中被异位激活或删除，以确定它们在药物敏感性或耐药性中的作用。