The role of HO-1 in Flt3-ITD positive AML proliferation and drug resistance

HO-1在Flt3-ITD阳性AML增殖和耐药中的作用

• 批准号: 8827164
• 负责人: Mary Irwin
• 金额: $ 5.33万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2015-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8827164
• 关键词: Acute Myelocytic Leukemia; Address; Anthracyclines; Antioxidants; Apoptosis; Apoptotic; Area; BAY 54-9085; Biological; Cancer Model; Cell Line; Cell Proliferation; Cell Survival; Cell model; Cells; Clinical; Data; Dependence; Diagnosis; Disease; Drug resistance; Environment; Enzymes; Gene Mutation; Growth; Heat shock proteins; Heme; Human; In Vitro; Life Expectancy; Malignant Neoplasms; Mediating; Messenger RNA; Metabolism; Methods; Modeling; Molecular; Mutation; Neoplasm Metastasis; Oncogenic; Outcome; Oxidation-Reduction; Pathway interactions; Patients; Phenotype; Phosphotransferases; Production; Proteins; Public Health; Reactive Oxygen Species; Receptor Protein-Tyrosine Kinases; Regulation; Relapse; Research; Resistance; Role; Sampling; Signal Transduction; Small Interfering RNA; Specimen; Survival Rate; Techniques; Testing; Therapeutic; Therapeutic Intervention; Tissue Microarray; Transcriptional Regulation; Treatment outcome; Tyrosine Kinase Inhibitor; United States; Up-Regulation; Vascular Endothelial Growth Factor Receptor-1; Work; angiogenesis; cancer cell; cell type; chemical genetics; clinical efficacy; genetic inhibitor; heme oxygenase-1; improved; inhibitor/antagonist; kinase inhibitor; leukemia; mutant; novel; public health relevance; receptor; therapy resistant; tumorigenesis

DESCRIPTION (provided by applicant): With current treatment options, the five-year survival rate for patients with AML is only 25%, thus understanding mechanisms of relapse and resistance is important therapeutically. The most common aberration in AML results in activation of the fms-like receptor 3 (Flt3-ITD), which was recently shown to alter the redox environment of cancer cells. While these changes remain poorly understood, elevations of reactive oxygen species can promote the cancer phenotype. Heme oxygenase 1 (HO-1) is a ROS-induced anti-oxidant that can also inhibit apoptosis and promote metabolism leading to cell survival and drug resistance. Our preliminary data suggest that, Flt3-ITD-expressing cells contain elevated constitutive expression of HO-1 as compared to Flt3-wildtype (WT) expressing cells. Further, knockdown of HO-1 with siRNA results in decreased proliferation and viability of Flt3-ITD expressing cells. We hypothesize that Flt3-ITD-dependent kinase signaling and ROS production increase constitutive expression of HO-1, leading to activation of anti- oxidant and anti-apoptotic pathways and resulting in proliferation and drug resistance in AML. To test our hypothesis, we will 1) Determine the molecular mechanisms by which HO-1 is constitutively expressed in Flt3- ITD positive AML and the functional consequences of this expression and 2) Elucidate the role of HO-1 in therapeutic resistance of AML. The isogenic BaF3 Flt3-WT and Flt3-ITD cell lines will be used in combination with human Flt3-ITD positive AML cell lines MOLM-13 and MV4.11 to test both specific aims. To complete Aim 1, we will examine the Flt3-kinase and ROS dependence of HO-1 expression in Flt3-ITD positive cells. Transcriptional regulation of HO-1 expression will also be evaluated. In vitro findings will be further assessed ex vivo utilizing tisue microarray specimens from AML patients. The effects of HO-1 expression on Flt3-ITD positive AML will be delineated utilizing chemical and genetic inhibitors of HO-1. For Aim 2, we will determine the contribution of HO-1 to chemoresistance of Flt3-ITD expressing cells utilizing the afore mentioned HO-1 inhibition methods. Using similar techniques, we will also evaluate the contribution of HO-1 to de novo and acquired resistance to the Flt3 inhibitors lestaurtinib and sorafenib. These studies together will provide a greater understanding of the redox mechanisms underlying Flt3-ITD expressing AML, and will better equip us to therapeutically target the biological pathways that promote AML progression and drug resistance. PUBLIC HEALTH RELEVANCE: The proposed studies address a research area that has largely been unstudied and focuses on the role of an antioxidant, HO-1, in growth, survival, and drug resistance of Flt3-ITD positive acute myeloid leukemia (AML). This research is relevant to public health because understanding how antioxidants can contribute to growth, survival and drug resistance of cancer cells will enhance our ability to clinically treat the 30% of AML patient whose disease expresses the Flt3-ITD mutation, and possibly extend the life expectancy of patients diagnosed with this disease.

描述（申请人提供）：在目前的治疗方案下，AML患者的五年生存率仅为25%，因此了解复发和耐药机制在治疗上很重要。 AML 中最常见的异常会导致 fms 样受体 3 (Flt3-ITD) 的激活，最近显示该受体可以改变癌细胞的氧化还原环境。虽然这些变化仍然知之甚少，但活性氧的升高可以促进癌症表型。血红素加氧酶 1 (HO-1) 是一种 ROS 诱导的抗氧化剂，还可以抑制细胞凋亡并促进新陈代谢，从而导致细胞存活和耐药性。我们的初步数据表明，与 Flt3 野生型 (WT) 表达细胞相比，Flt3-ITD 表达细胞含有升高的 HO-1 组成型表达。此外，用 siRNA 敲低 HO-1 会导致 Flt3-ITD 表达细胞的增殖和活力降低。我们假设 Flt3-ITD 依赖性激酶信号传导和 ROS 产生增加了 HO-1 的组成型表达，从而导致抗氧化和抗凋亡的激活 途径并导致 AML 的增殖和耐药性。为了检验我们的假设，我们将 1) 确定 HO-1 在 Flt3-ITD 阳性 AML 中组成型表达的分子机制以及该表达的功能后果，以及 2) 阐明 HO-1 在 AML 治疗耐药中的作用。同基因 BaF3 Flt3-WT 和 Flt3-ITD 细胞系将​​与人 Flt3-ITD 阳性 AML 细胞系 MOLM-13 和 MV4.11 组合使用，以测试这两个特定目标。为了完成目标 1，我们将检查 Flt3-ITD 阳性细胞中 HO-1 表达的 Flt3 激酶和 ROS 依赖性。 HO-1 表达的转录调节也将被评估。体外研究结果将利用来自 AML 患者的组织微阵列样本进行进一步评估。 HO-1 表达对 Flt3-ITD 阳性 AML 的影响将利用 HO-1 的化学和遗传抑制剂来描述。对于目标 2，我们将利用上述 HO-1 抑制方法确定 HO-1 对 Flt3-ITD 表达细胞的化疗耐药性的贡献。使用类似的技术，我们还将评估 HO-1 对 Flt3 抑制剂 lestaurtinib 和索拉非尼的从头耐药性和获得性耐药性的贡献。这些研究将帮助我们更好地了解表达 Flt3-ITD 的 AML 的氧化还原机制，并更好地帮助我们针对促进 AML 进展和耐药性的生物途径进行治疗。 公共健康相关性：拟议的研究涉及一个基本上未被研究的研究领域，重点是抗氧化剂 HO-1 在 Flt3-ITD 阳性急性髓系白血病 (AML) 的生长、存活和耐药性中的作用。这项研究与公共卫生相关，因为了解抗氧化剂如何促进癌细胞的生长、存活和耐药性将提高我们临床治疗 30% 表达 Flt3-ITD 突变的 AML 患者的能力，并可能延长诊断患有这种疾病的患者的预期寿命。