Development of novel anti-leukemia agents targeting the menin-MLL interaction

开发针对 menin-MLL 相互作用的新型抗白血病药物

• 批准号: 8512580
• 负责人: Jolanta Grembecka
• 金额: $ 30.33万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2016-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8512580
• 关键词: Acute Myelocytic Leukemia; Acute leukemia; Adult; Adverse effects; Affect; Apoptosis; Binding; Biochemical; Blood Cells; Bone Marrow Cells; Cells; Cellular Assay; Characteristics; Child; Chimeric Proteins; Chromosomal translocation; Clinical Trials; DNA Sequence Rearrangement; Data; Development; Dominant-Negative Mutation; Drug Kinetics; Generations; Genes; Goals; Growth; Hematopoiesis; Human; Inhibitory Concentration 50; Laboratories; Lead; Lymphoblastic Leukemia; MEN1 gene; MLL gene; Maximum Tolerated Dose; Mediating; Menin; Metabolic; Methods; Molecular Target; Mus; Mutagenesis; N-terminal; Oncogene Proteins; Oncogenic; Outcome; Patients; Peptides; Pharmaceutical Chemistry; Pharmaceutical Preparations; Property; Proteins; Proto-Oncogenes; Reporting; Research; Specificity; Structure-Activity Relationship; Survival Rate; Testing; Therapeutic Agents; Therapeutic Intervention; Toxic effect; analog; base; cell growth; cofactor; design; drug candidate; drug discovery; high throughput screening; improved; in vivo; inhibitor/antagonist; innovation; leukemia; leukemogenesis; mouse model; multidisciplinary; novel; novel therapeutic intervention; novel therapeutics; outcome forecast; pre-clinical; scaffold; small molecule

DESCRIPTION (provided by applicant): Chromosomal translocations that affect the proto-oncogene MLL (Mixed Lineage Leukemia) occur in aggressive human acute leukemias, both in children and adults. Fusion of MLL to one of more than 60 partner genes results in generation of the MLL fusion oncoprotein which upregulates expression of Hox genes required for normal hematopoiesis, and ultimately leads to the development of leukemia. Patients harboring fusion of the MLL gene suffer from very aggressive leukemias and respond poorly to available therapies, with only ~35% five-year survival rate, emphasizing that novel therapeutic treatments are urgently needed. All oncogenic MLL fusion proteins have a preserved N-terminal fragment of MLL that interacts with menin, a protein encoded by MEN1 (Multiple Endocrine Neoplasia 1) gene. Importantly, the interaction of menin with the MLL fusion proteins is critical to the leukemogenic activity of the MLL fusions. Therefore, menin functions as an essential oncogenic cofactor in MLL leukemias, and represents a valuable molecular target for therapeutic intervention. We hypothesize that direct targeting of the interaction between menin and MLL fusion proteins with small molecules will reverse the oncogenic potential of MLL fusions and will inhibit the development of leukemia. By applying two independent high throughput screens, we identified over 20 small molecules which specifically bind to menin and inhibit the menin-MLL interaction. These compounds, which belong to several distinct chemotypes, represent the first small molecule inhibitors targeting this interaction. Applying a combination of biochemical, biophysical and cellular assays we were able to evaluate their potency, specificity, and mechanism of action. The most potent compounds competitively displace the MLL-derived peptide from menin with the IC50 values at low micromolar range, with the most potent MI-1 and MI-2 representing two different scaffolds. These compounds selectively inhibit the growth of leukemia cells with MLL translocations, and induce apoptosis and differentiation of MLL leukemia cells. We have tested analogues of MI-1 and MI-2 to establish an initial structure-activity relationship and improve their potency. The most potent analogue of MI-1 synthesized in our laboratory has IC50 = 430 nM for inhibition of the menin-MLL interaction. This compound selectively inhibits the cell growth, induces apoptosis and differentiation of MLL leukemia cells, substantially downregulates expression of Hoxa9 and Meis1 genes, and inhibits transformation by MLL fusion oncoprotein, demonstrating a highly specific mode of action. In this project we propose to further optimize these lead compounds by combining medicinal chemistry, NMR, biochemical and biophysical methods. Compounds will be tested for their activity in leukemia cells and on normal bone marrow cells to validate their mechanism of action and exclude compounds which might cause toxicity issues. In vivo efficacy studies in mouse models of MLL leukemia will also be pursued for selected compounds. If successful, our studies will result in compounds which may provide a novel therapeutic approach for the treatment of leukemias with MLL translocations.

描述（由申请方提供）：影响原癌基因MLL（混合谱系白血病）的染色体易位发生在侵袭性人类急性白血病（儿童和成人）中。MLL与超过60个伴侣基因之一的融合导致MLL融合癌蛋白的产生，其上调正常造血所需的Hox基因的表达，并最终导致白血病的发展。携带MLL基因融合的患者患有非常侵袭性的白血病，并且对可用的疗法反应不佳，五年存活率仅为~35%，强调迫切需要新的治疗性治疗。所有的致癌MLL融合蛋白都有一个保留的MLL N-末端片段，它与menin相互作用，menin是一种由MEN 1（多发性内分泌瘤1）基因编码的蛋白质。重要的是，menin与MLL融合蛋白的相互作用对MLL融合蛋白的致白血病活性至关重要。因此，menin在MLL白血病中作为一种重要的致癌辅因子发挥作用，并代表了治疗干预的有价值的分子靶点。我们假设，直接靶向与小分子的menin和MLL融合蛋白之间的相互作用将逆转MLL融合的致癌潜力，并将抑制白血病的发展。通过应用两个独立的高通量筛选，我们鉴定了超过20种特异性结合menin并抑制menin-MLL相互作用的小分子。这些化合物属于几种不同的化学型，代表了靶向这种相互作用的第一种小分子抑制剂。应用生物化学，生物物理学和细胞测定的组合，我们能够评估其效力，特异性和作用机制。最有效的化合物以低微摩尔范围的IC 50值竞争性地置换来自menin的MLL衍生肽，其中最有效的MI-1和MI-2代表两种不同的支架。这些化合物选择性地抑制具有MLL易位的白血病细胞的生长，并诱导MLL白血病细胞的凋亡和分化。我们已经测试了MI-1和MI-2的类似物，以建立初始结构-活性关系并提高其效力。我们实验室合成的MI-1的最有效类似物抑制menin-MLL相互作用的IC 50 = 430 nM。该化合物选择性地抑制细胞生长，诱导MLL白血病细胞的凋亡和分化，显著下调Hoxa 9和Meis 1基因的表达，并抑制MLL融合癌蛋白的转化，证明了高度特异性的作用模式。在这个项目中，我们建议进一步优化这些先导化合物结合药物化学，核磁共振，生物化学和生物物理方法。将测试化合物在白血病细胞和正常骨髓细胞中的活性，以验证其作用机制并排除可能导致毒性问题的化合物。还将对选定的化合物进行MLL白血病小鼠模型中的体内疗效研究。如果成功，我们的研究将产生化合物，可能为治疗MLL易位的白血病提供新的治疗方法。