ROS-targeted therapy for pancreatic cancer

ROS靶向治疗胰腺癌

• 批准号: 8963517
• 负责人: NOURI NEAMATI
• 金额: $ 46.1万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2020-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8963517
• 关键词: Abraxane; Acute Myelocytic Leukemia; Adenocarcinoma Cell; Affect; Antioxidants; Apoptosis; Biodistribution; Caspase; Cell Death; Cell Line; Cell Respiration; Cells; Characteristics; Clinical; DNA Damage; Drug resistance; Engineering; Epithelial; Equilibrium; Fibroblasts; Generations; Genes; Genetic Transcription; Genetically Engineered Mouse; Human; KRAS2 gene; Laboratories; Lead; Libraries; Malignant Neoplasms; Malignant neoplasm of pancreas; Measures; Mediating; Metabolic; Metabolism; Mitochondria; Modeling; Mus; Mutate; Necrosis; Normal Cell; Oncogenic; Oxidation-Reduction; Oxidative Stress; Oxygen Consumption; Pancreas; Pancreatic Ductal Adenocarcinoma; Pathway interactions; Patients; Phosphorylation; Play; Population; Production; Proto-Oncogene Proteins c-akt; Radiation therapy; Reactive Oxygen Species; Research Personnel; Resveratrol; Role; Safety; Series; Signal Transduction; Stem cells; Technology; Testing; Therapeutic Intervention; Toxic effect; Transgenic Mice; Xenograft Model; analog; cancer cell; cancer stem cell; cancer therapy; chemotherapy; design; extracellular; gemcitabine; in vivo; innovation; mouse model; neoplastic cell; next generation sequencing; novel; novel therapeutic intervention; parthenolide; public health relevance; self-renewal; senescence; stem; targeted treatment; transcription factor; tumor

 DESCRIPTION (provided by applicant): Cancer cells are under persistent oxidative stress. Oncogenic transformation such as with Kras, and metabolic alterations result in increased oxidative stress in tumor cells. Tumor cells adapt to persistent oxidative stress by activating redox sensitive transcription factors that increase the expression of endogenous antioxidants, promote survival pathways, induce chemoresistance, and reduce caspase activation. More significantly, ROS also plays an important role in the survival of cancer stem cells. A subset population of cancer stem cells contains lower ROS levels, thus providing protection against DNA damage such as radiotherapy. Moreover, the self-renewal capacity of cancer stem cells is sensitive to cellular ROS levels. Both bulk tumor and cancer stem cells are vulnerable to excess levels of ROS and this characteristic can be exploited for therapy. Our overarching hypothesis is that compounds able to effectively increase the levels of ROS in cancer cells will tip the balance towards cell death and can potentially overcome drug resistance. Recently, we screened a library of highly diverse compounds on an Extracellular Flux Analyzer that measures cellular respiration. Among hundreds of compounds screened, we identified DFC232, a compound that caused a maximum oxygen consumption rate (OCR) in Mia PaCa-2 cells. DFC232 induced rapid onset of ROS production and activation of AKT, followed by a substantial increase in the phosphorylation of the transcription factor FOXO3a, culminating in cell death. DFC232 shows single agent activity in a Mia PaCa-2 xenograft model with no signs of toxicity. In subsequent mechanistic studies, using a novel next-generation sequencing technology (Bru-Seq), we observed that DFC232 produced a remarkable inactivation of mitochondrial gene transcription by potentially affecting the D-loop. Our first round of ADMET-guided lead optimization campaign generated compounds (e.g. DFC325) with nanomolar potency in a panel of PDAC cell lines and remarkable single agent efficacy in mice. Our central hypothesis is that DFC232 and analogs induce ROS production, tipping the balance toward apoptosis. We further hypothesize that DFCs act through a novel mechanism by effectively disrupting transcription from the mitochondrial D-loop. Moreover, DFC analogs are novel agents with unique targets and have biodistribution, safety, and efficacy characteristics necessary for potential clinical benefit in PDAC treatment. To test our hypothesis we will focus on the following specific aims: Aim 1: To perform ADMET, metabolic, and PK-guided synthesis of novel analogs to enhance potency and efficacy. Aim 2: To perform mechanistic studies of top 5 compounds as single agent and in combination with gemcitabine and abraxane using Bru-Seq technology. Aim 3: To determine the in vivo efficacy of top 5 compounds as single agents and in combination with gem/abraxane in orthotopic and genetically engineered mouse models (GEMM) of KRAS driven pancreatic cancer.

 描述（由申请人提供）：癌细胞处于持续的氧化应激之下。 Kras 等致癌转化和代谢改变会导致肿瘤细胞氧化应激增加。肿瘤细胞通过激活氧化还原敏感转录因子来适应持续的氧化应激，这些转录因子增加内源性抗氧化剂的表达，促进生存途径，诱导化疗耐药性并减少半胱天冬酶激活。更重要的是，ROS在癌症干细胞的存活中也发挥着重要作用。癌症干细胞的一个亚群含有较低的 ROS 水平，从而提供针对放射治疗等 DNA 损伤的保护。此外，癌症干细胞的自我更新能力对细胞ROS水平敏感。肿瘤干细胞和癌症干细胞都容易受到过量活性氧的影响，这一特性可用于治疗。我们的总体假设是，能够有效提高癌细胞中活性氧水平的化合物将打破细胞死亡的平衡，并有可能克服耐药性。最近，我们在测量细胞呼吸的细胞外通量分析仪上筛选了高度多样化的化合物库。在筛选的数百种化合物中，我们鉴定出了 DFC232，这是一种在 Mia PaCa-2 细胞中引起最大耗氧率 (OCR) 的化合物。 DFC232 诱导 ROS 快速产生并激活 AKT，随后转录因子 FOXO3a 的磷酸化大幅增加，最终导致细胞死亡。 DFC232 在 Mia PaCa-2 异种移植模型中显示出单药活性，且没有毒性迹象。在随后的机制研究中，使用新型新一代测序技术 (Bru-Seq)，我们观察到 DFC232 通过潜在影响 D 环而导致线粒体基因转录显着失活。我们的第一轮 ADMET 指导的先导化合物优化活动产生了在一组 PDAC 细胞系中具有纳摩尔效力的化合物（例如 DFC325），并且在小鼠中具有显着的单药功效。我们的中心假设是 DFC232 和类似物诱导 ROS 产生，使平衡向细胞凋亡倾斜。我们进一步假设 DFC 通过一种新的机制发挥作用，有效破坏线粒体 D 环的转录。此外，DFC 类似物是具有独特靶点的新型药物，具有 PDAC 治疗潜在临床益处所必需的生物分布、安全性和功效特征。为了检验我们的假设，我们将重点关注以下具体目标： 目标 1：对新型类似物进行 ADMET、代谢和 PK 指导合成，以增强效力和功效。目标 2：使用 Bru-Seq 技术对单药以及与吉西他滨和 abraxane 联合使用的前 5 种化合物进行机理研究。目标 3：确定前 5 种化合物作为单一药物以及与 gem/abraxane 组合在 KRAS 驱动的胰腺癌原位和基因工程小鼠模型 (GEMM) 中的体内疗效。