KLF9-dependent pathways in multiple myeloma drug resistance

多发性骨髓瘤耐药中 KLF9 依赖性途径

• 批准号: 9806425
• 负责人: Mikhail Nikiforov
• 金额: $ 37.08万
• 依托单位: WAKE FOREST UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-12-01 至 2020-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9806425
• 关键词: Anabolism; Antineoplastic Agents; Antirheumatic Agents; Apoptosis; Apoptotic; Auranofin; Binding; Binding Sites; Biological Assay; Bortezomib; Cell Death; Cell Line; Cell Proliferation; Cells; Cessation of life; ChIP-seq; Computer Simulation; DNA-Protein Interaction; Disease; Drug resistance; Enzymes; Epigenetic Process; FDA approved; Gene Expression; Generations; Genes; Genetic; Genetic Transcription; Goals; Hematologic Neoplasms; Hematology; Individual; Inherited; Intervention; Kruppel-like transcription factors; Maximum Tolerated Dose; Mediating; Messenger RNA; Mitochondria; Modeling; Molecular; Multiple Myeloma; Mus; Oxidative Stress; Pathway interactions; Patients; Pattern; Pharmacology; Plasma Cells; Polyamines; Proteasome Inhibitor; Proteins; Refractory; Regulation; Relapse; Reporting; Resistance; Reverse Transcriptase Polymerase Chain Reaction; Role; SCID Mice; Specificity; Testing; Therapeutic; Time; Tumor Burden; Up-Regulation; Xenograft procedure; analog; biological adaptation to stress; cytotoxicity; differential expression; endoplasmic reticulum stress; experimental study; gain of function; gene repression; head-to-head comparison; improved; inhibitor/antagonist; interest; mouse model; novel; overexpression; promoter; public health relevance; response; targeted agent; thioredoxin reductase; transcription factor; tumor; voltage-dependent anion channel 2

 DESCRIPTION (provided by applicant): Multiple myeloma (MM) is a plasma cell disorder that accounts for approximately 10% of all hematologic malignancies. Reversible proteasome inhibitor bortezomib (BTZ) in combination with other agents represents a major strategy for MM treatment. Approved in 2012, irreversible proteasome inhibitor carfilzomib (CFZ) demonstrated promising results in relapsed/refractory MM tumors and more potently induced death in MM cells than BTZ. Although the overall survival of MM patients has substantially increased, the disease remains incurable. The mechanisms of BTZ and CFZ cytotoxicity in MM cells are far from being understood. The ultimate goal of this proposal is to characterize such mechanisms and to identify novel targets for MM intervention. Recently, we have demonstrated that BTZ induces death in MM cells in part via epigenetic upregulation of the levels of Kruppel-like transcription factor 9 (KLF9). Moreover, KLF9 mRNA levels in MM cells isolated from patients prior to BTZ therapy (as assessed by microarrays) correlated with good response to BTZ treatment. CFZ demonstrated higher cytotoxicity than BTZ. We showed via head-to-head comparison that CFZ upregulates KLF9 levels even more efficiently than BTZ. Thus we will test the hypothesis that upregulation of KLF9 is a common mechanism of cytotoxicity of BTZ and CFZ, and that the higher cytotoxicity of CFZ is due to a more efficient induction of KLF9. KLF9-dependent pathways underlying cytotoxicity of BTZ and CFZ are unknown. In search for such pathways, we utilized ChIP-Seq and quantitative RT-PCR assays and discovered that KLF9 suppresses expression of genes that directly or indirectly decrease oxidative stress. Among KLF9 targets involved in response to oxidative stress, we identified two genes that demonstrated KLF9-, CFZ- and BTZ-dependent expression pattern and whose genetic or pharmacological inhibition partially recapitulates the effects induced in these cells by BTZ or CFZ. Thus, we will test the hypothesis that partial depletion of KLF9 targets mediates cytotoxicity of BTZ and CFZ, while more efficient genetic or pharmacological inhibition of these targets reduces tumor burden and increases efficacy of BTZ or CFZ in a mouse model of MM.

 描述（由申请人提供）：多发性骨髓瘤 (MM) 是一种浆细胞疾病，约占所有血液系统恶性肿瘤的 10%。可逆蛋白酶体抑制剂硼替佐米 (BTZ) 与其他药物联合使用是治疗 MM 的主要策略。不可逆蛋白酶体抑制剂卡非佐米 (CFZ) 于 2012 年获得批准，在复发/难治性 MM 肿瘤中显示出良好的效果，并且比 BTZ 更能有效诱导 MM 细胞死亡。尽管多发性骨髓瘤患者的总生存率大幅提高，但该疾病仍然无法治愈。 BTZ 和 CFZ 对 MM 细胞的细胞毒性机制尚不清楚。该提案的最终目标是描述此类机制的特征并确定 MM 干预的新目标。 最近，我们证明 BTZ 部分通过表观遗传上调 Kruppel 样转录因子 9 (KLF9) 水平诱导 MM 细胞死亡。此外，在 BTZ 治疗之前从患者体内分离的 MM 细胞中的 KLF9 mRNA 水平（通过微阵列评估）与 BTZ 治疗的良好反应相关。 CFZ 表现出比 BTZ 更高的细胞毒性。我们通过头对头比较表明，CFZ 上调 KLF9 水平的效率甚至比 BTZ 还要高。因此，我们将检验以下假设：KLF9 的上调是 BTZ 和 CFZ 细胞毒性的常见机制，并且 CFZ 较高的细胞毒性是由于 KLF9 更有效的诱导。 BTZ 和 CFZ 细胞毒性的 KLF9 依赖性途径尚不清楚。在寻找此类途径时，我们利用 ChIP-Seq 和定量 RT-PCR 检测，发现 KLF9 抑制直接或间接减少氧化应激的基因表达。在参与氧化应激反应的 KLF9 靶标中，我们鉴定了两个基因，它们表现出 KLF9、CFZ 和 BTZ 依赖性表达模式，并且其遗传或药理学抑制部分概括了 BTZ 或 CFZ 在这些细胞中诱导的作用。因此，我们将测试以下假设：KLF9 靶标的部分耗尽介导 BTZ 和 CFZ 的细胞毒性，而这些靶标的更有效的遗传或药理学抑制可减少肿瘤负荷并提高 MM 小鼠模型中 BTZ 或 CFZ 的功效。