Regulating Sensitivity to Cancer Therapy with Engineered Transcription Factors

描述(由申请人提供)：凋亡途径的解除调控是导致对旨在诱导细胞死亡的癌症治疗方法产生抵抗的原因。尽管对细胞凋亡的理解已经取得了许多进展，但对特定的凋亡刺激的抗性或敏感性所涉及的分子特征尚不清楚。识别影响细胞对细胞凋亡治疗反应的基因，将极大地促进肿瘤细胞生物学领域的发展和合理设计有效的抗癌策略。特别是，这项研究将集中在肿瘤坏死因子相关的凋亡诱导配体(TRAIL)，它选择性地刺激癌细胞中的细胞死亡，而不是正常细胞。然而，正常细胞和特定转化细胞获得TRAIL抗性的机制仍然知之甚少。我们的长期目标是为设计有效的抗癌疗法寻找新的基因靶点。这项拟议工作的基本原理是，工程转录因子文库是一种独特而强大的工具，可以用来识别与调节诱导凋亡的癌症治疗敏感或耐药有关的基因。这项提案的总体目标是确定针对改进的基于细胞凋亡的疗法的目标基因。我们的假设是，由工程转录因子(ETF)文库识别的基因将调节对TRAIL介导的细胞凋亡的敏感性和抵抗力。这一目标将通过验证我们的假设来实现，具体目的如下：(1)确定调节TRAIL诱导的细胞凋亡敏感性的基因；(2)确定调控TRAIL介导的抑制肿瘤发展的基因；(3)评估TRAIL受体和诱骗受体表达在调节TRAIL敏感性中的作用。赞助商的实验室最近开发了ETF文库，以激活或抑制与复杂细胞表型相关的基因的表达。我们将使用这个工具，通过基于凋亡的选择策略，在癌细胞和正常细胞中识别赋予TRAIL耐药性或增强TRAIL敏感性的基因。此外，我们将使用这些文库结合人类异种移植瘤模型来识别体内调节TRAIL活性的基因。最后，ETF将被用来调节TRAIL受体的表达，并阐明这些受体在选择性TRAIL活性中的作用。这项工作中确定的基因将作为设计癌症疗法的基础，这种疗法可以在对正常组织影响最小的情况下有效地消除癌细胞。这些治疗方法将极大地提高癌症患者的生活质量，在治疗过程中最大限度地保护非癌症器官的健康，限制重复治疗的需要，并降低因癌症治疗无效而导致的死亡率。

DESCRIPTION (provided by applicant): Deregulation of the apoptotic pathway is responsible for resistance to cancer therapeutics designed to induce cell death. Although there have been many advances in understanding apoptosis, the molecular characteristics involved in resistance or sensitivity to specific apoptotic stimuli are unclear. The identification of genes, which influence the cellular response to apoptosis-based therapeutics will significantly advance the field of cancer cell biology and the rational design of effective anti-cancer strategies. In particular, this research will focus on the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), which selectively stimulates cell death in cancer cells but not normal cells. However the mechanisms by which normal cells and particular transformed cells obtain resistance to TRAIL remain poorly understood. Our long-term goal is to identify novel gene targets for the design of effective anti-cancer therapeutics. The rationale for the proposed work is that libraries of engineered transcription factors are a unique and powerful tool for identifying genes involved in regulating sensitization or resistance to apoptosis-inducing cancer therapies. The overall objective of this proposal is to identify genes to be targeted for improved apoptosis-based therapeutics. Our hypothesis is that genes identified by libraries of engineered transcription factors (ETFs) will modulate sensitivity and resistance to TRAIL-mediated apoptosis. The objective will be accomplished by testing our hypothesis with the following specific aims: (1) Identify genes that regulate sensitivity to TRAIL-induced apoptosis; (2) Identify genes that regulate TRAIL-mediated suppression of tumor development; (3) Evaluate the role of TRAIL receptor and decoy receptor expression in regulating TRAIL sensitivity. Libraries of ETFs have been recently developed by the sponsor's laboratory to activate or repress the expression of genes associated with complex cellular phenotypes. We will use this tool to identify genes that confer resistance or enhance sensitivity to TRAIL in cancerous and normal cells using an apoptosis-based selection strategy. Additionally, we will use these libraries in combination with a human xenograft tumor model to identify genes that regulate TRAIL activity in vivo. Finally, ETFs will be used to regulate TRAIL receptor expression and elucidate the role of these receptors in selective TRAIL activity. The genes identified in this work will serve as the basis for designing cancer therapies that effectively eliminate cancer cells with minimal effects on normal tissues. These treatments will dramatically enhance the quality of life of cancer patients by maximizing the health of non-cancerous organs during treatment, limiting the need for repeated treatments, and decreasing mortality resulting from ineffective cancer therapy.