Histone Deacetylase Inhibitor Based Therapy of AML

基于组蛋白脱乙酰酶抑制剂的 AML 治疗

• 批准号: 8124098
• 负责人: KAPIL BHALLA
• 金额: $ 14.29万
• 依托单位: UNIVERSITY OF KANSAS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-05-04 至 2012-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8124098
• 关键词: 17-(Dimethylaminoethylamino)-17-Demethoxygeldanamycin; Acetylation; Antibodies; Apoptosis; Attenuated; Binding; Blast Cell; CD34 gene; Cells; Client; Clinical; Combined Modality Therapy; Complex; DNA Sequence Rearrangement; Data; Deacetylase; Geldanamycin; Gene Mutation; Gene Rearrangement; Genes; Genetic Transcription; Growth; HDAC6 gene; Heat-Shock Proteins 90; Histone Acetylation; Histone Deacetylase; Histone Deacetylase Inhibitor; Histones; Human; Hydroxamic Acids; In Vitro; Laboratories; MEKs; Mediating; Molecular; Molecular Chaperones; Mutation; Nuclear; Oncogene Proteins; Oncogenes; Outcome; PKC412; Proteins; Proto-Oncogene Protein c-kit; Proto-Oncogene Proteins c-akt; Ras/Raf; Recruitment Activity; Research Personnel; STAT5A gene; Signal Transduction; Stem cells; TNFRSF10A gene; TNFRSF10B gene; TNFSF10 gene; Testing; Time; Vorinostat; analog; attenuation; base; cytotoxicity; effusion; improved; in vivo; inhibitor/antagonist; kinase inhibitor; leukemia; mutant; neoplastic cell; novel; preclinical study; programs

DESCRIPTION (provided by applicant): Novel therapies directed against biologic targets in AML are needed to further improve the clinical outcome in AML. Recent studies have clarified that AML often results when a class of genetic mutations or gene rearrangements that confer a proliferative/and or survival advantage (e.g., activating mutations in FLT-3, N-Ras, K-Ras, and c-Kit) collaborates with a second class effusion oncogenes (e.g., AML1/ETO and TEL/AML1) that act as the dominant inhibitors of transcription through the recruitment of nuclear corepressors/histone deacetylase (HDAC) complexes known to suppress hemopoietic differentiation and subsequent apoptosis of the hemopoietic progenitor cells. Hence, HDAC inhibitors (HDI), which induce histone acetylation, p21WAF1 expression and proapoptotic genes de-repress the block in differentiation and induce apoptosis of AML cells. Recent findings from our laboratory have demonstrated that hydroxamic acid analogue (HAA) class of potent pan-HDAC inhibitors (HDIs) (e.g., SAHA, LAQ824 and LBH589) also induce acetylation of heat shock protein 90, which disrupts its chaperone binding to its client proteins, including mutant FLT-3, c-Raf and AKT, directing them to polyubiquitylation and proteasomal degradation. Consequently, HAA-HDIs can undermine the synergy between the fusion oncoproteins (recruiting HDACs) and mutant FLT-3 and its downstream pro-growth and pro-survival signaling in AML. Furthermore, our preliminary data indicate that HAA HDIs exert synergistic cytotoxicity with FLT-3 kinase inhibitor PKC412 against mutant FLT-3-harboring AML blasts. Based on these findings, the overall objectives of this proposal are to elucidate the molecular mechanisms of interaction and efficacy of HAA-HDIs combined with other novel and conventional antileukemia agents in the cultured and primary AML cells. The specific aims of this proposal are: AIM 1: To determine the effect of mutant FLT-3 expression and activity on HAA-HDI-induced apoptosis of human leukemia cells, as well as to determine the mechanism involved in HAA-HDI mediated sensitization of human AML cells with or without mutant FLT-3 to the extrinsic pathway of apoptosis induced by Apo-2L/TRAIL or the agonistic DR4 and DR5 antibodies. AIM 2: To determine the mechanism of HAA-HDI-induced hsp90 acetylation and inhibition of the chaperone association of hsp90 with its client proteins, e.g., mutant (m) FLT-3 in AML cells. These studies will also determine HAA-HDI-mediated attenuation of the downstream pro-growth and/or survival signaling through AKT, Raf/MEK/ERK and STAT5, and the resulting sensitization of mutant FLT-3 containing human AML cells to the inhibitors of FLT-3. AIM 3: To determine the in vitro and in vivo effects of combining HAA-HDIs with hsp90 antagonist 17-allylamino-demethoxy-geldanamycin (AAG) and its more soluble analogue 17-DMAG in attenuating mFLT-3 and the downstream pro-growth and pro-survival signaling in human AML cells. The proposed pre-clinical studies could potentially define HAA-HDI based novel combinations and generate the rationale to test their in vivo efficacy against human AML cells.

描述（由申请人提供）：需要针对 AML 生物靶点的新疗法来进一步改善 AML 的临床结果。 最近的研究已阐明，当一类赋予增殖/和/或生存优势的基因突变或基因重排（例如，FLT-3、N-Ras、K-Ras 和 c-Kit 中的激活突变）与第二类渗出癌基因（例如 AML1/ETO 和 TEL/AML1）合作时，通常会导致 AML，而第二类渗出癌基因通过招募 核辅阻遏物/组蛋白脱乙酰酶 (HDAC) 复合物已知可抑制造血祖细胞的造血分化和随后的凋亡。 因此，诱导组蛋白乙酰化、p21WAF1 表达和促凋亡基因的 HDAC 抑制剂 (HDI) 可以解除对分化的抑制，并诱导 AML 细胞凋亡。 我们实验室的最新研究结果表明，异羟肟酸类似物 (HAA) 类强效泛 HDAC 抑制剂 (HDI)（例如 SAHA、LAQ824 和 LBH589）也会诱导热休克蛋白 90 的乙酰化，从而破坏其分子伴侣与其客户蛋白（包括突变型 FLT-3、c-Raf 和 A​​KT）的结合，从而引导它们 多泛素化和蛋白酶体降解。 因此，HAA-HDI 可以破坏融合癌蛋白（招募 HDAC）和突变体 FLT-3 及其下游 AML 中促生长和促生存信号传导之间的协同作用。 此外，我们的初步数据表明，HAA HDIs 与 FLT-3 激酶抑制剂 PKC412 对携带突变型 FLT-3 的 AML 母细胞发挥协同细胞毒性。 基于这些发现，本提案的总体目标是阐明 HAA-HDI 与其他新型和常规抗白血病药物联合在培养和原代 AML 细胞中相互作用和功效的分子机制。 本提案的具体目标是： 目的 1：确定突变体 FLT-3 表达和活性对 HAA-HDI 诱导的人白血病细胞凋亡的影响，以及确定在有或没有突变体 FLT-3 的情况下，HAA-HDI 介导的人 AML 细胞对 Apo-2L/TRAIL 或激动性 DR4 和 DR5 抗体诱导的细胞凋亡外在途径敏感的机制。 目标 2：确定 HAA-HDI 诱导的 hsp90 乙酰化以及抑制 hsp90 与其客户蛋白（例如 AML 细胞中的突变体 (m) FLT-3）分子伴侣关联的机制。 这些研究还将确定 HAA-HDI 介导的下游促生长和/或生存信号通过 AKT、Raf/MEK/ERK 和 STAT5 的减弱，以及由此产生的含有突变型 FLT-3 的人 AML 细胞对 FLT-3 抑制剂的敏感性。 目标 3：确定 HAA-HDI 与 hsp90 拮抗剂 17-烯丙氨基-去甲氧基-格尔德霉素 (AAG) 及其更可溶的类似物 17-DMAG 组合在减弱人类 AML 细胞中 mFLT-3 和下游促生长和促生存信号传导方面的体外和体内效果。 拟议的临床前研究可能会定义基于 HAA-HDI 的新型组合，并为测试其针对人类 AML 细胞的体内功效提供依据。