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

基本信息

批准号：
8155109
负责人：
Jolanta Grembecka
金额：
$ 32.27万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
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/8155109
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

项目摘要

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. PUBLIC HEALTH RELEVANCE: We are proposing to develop small molecules that may reverse the oncogenic function of MLL fusion proteins in acute leukemias. Ultimately, such compounds could be used as highly specific drugs for treatment of patients with aggressive forms of leukemia, which poorly respond to current therapies.

描述（由申请人提供）：影响原癌基因MLL（混合谱系白血病）的染色体易位发生在儿童和成人的侵袭性人类急性白血病中。 MLL 与 60 多个伙伴基因之一融合，导致 MLL 融合癌蛋白的产生，该蛋白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，并且对现有疗法反应不佳，五年生存率仅为 35% 左右，这表明迫切需要新的治疗方法。所有致癌 MLL 融合蛋白都保留了 MLL 的 N 末端片段，该片段与 menin（一种由 MEN1（多发性内分泌肿瘤 1）基因编码的蛋白质）相互作用。重要的是，menin 与 MLL 融合蛋白的相互作用对于 MLL 融合体的致白血病活性至关重要。因此，menin 在 MLL 白血病中发挥着重要的致癌辅助因子的作用，并且代表了治疗干预的有价值的分子靶点。我们假设，用小分子直接靶向 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 20 多种小分子，它们特异性结合 menin 并抑制 menin-MLL 相互作用。这些化合物属于几种不同的化学类型，代表了第一个针对这种相互作用的小分子抑制剂。通过结合生物化学、生物物理和细胞测定，我们能够评估它们的效力、特异性和作用机制。最有效的化合物以低微摩尔范围的 IC50 值竞争性取代 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。我们实验室合成的最有效的 MI-1 类似物对于抑制 menin-MLL 相互作用的 IC50 = 430 nM。该化合物选择性抑制细胞生长，诱导 MLL 白血病细胞凋亡和分化，大幅下调 Hoxa9 和 Meis1 基因的表达，并抑制 MLL 融合癌蛋白的转化，表现出高度特异性的作用模式。在这个项目中，我们建议通过结合药物化学、核磁共振、生物化学和生物物理方法来进一步优化这些先导化合物。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。选定的化合物还将在 MLL 白血病小鼠模型中进行体内功效研究。如果成功，我们的研究将产生可能为治疗 MLL 易位白血病提供新的治疗方法的化合物。公共健康相关性：我们提议开发小分子，可以逆转急性白血病中 MLL 融合蛋白的致癌功能。最终，此类化合物可用作高度特异性药物，用于治疗对当前疗法反应不佳的侵袭性白血病患者。