Novel C/EBPalpha replacement therapy by microRNA mimics in acute myeloid leukemia

MicroRNA 模拟物治疗急性髓系白血病的新型 C/EBPα 替代疗法

• 批准号: 405833349
• 负责人: Professor Dr. Gerhard Behre
• 金额: --
• 依托单位: Klinik für Innere Medizin
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/405833349?language=en
• 关键词: Novel; EBPalpha; replacement; therapy; microRNA

Acute myeloid leukemia (AML) is a malignant disease of the hematopoietic system, and the outcome of patients suffering from AML is still very poor. The transcription factor C/EBP Alpha plays an important role in the normal differentiation of myeloid progenitor cells and subsequent cell death. An inactivation of C/EBP Alpha via different mechanisms is found in over 50% of AML cases, e.g. by inactivating mutations of the CEBPA-gene in 10% of cases. This leads to a block in differentiation and an accumulation of immature blast cells. Thus, it would be advantageous to re-activate C/EBP Alpha function in AML therapeutically, thus forcing the AML blasts to differentiate normally and die. MicroRNAs, a class of small non-coding RNAs, were identified as important regulators of normal hematopoiesis and AML development. We have previously shown that C/EBPα induces microRNAs miR-223, miR-34a, and miR-30c which are downregulated in C/EBP Alpha mutated AML. Within this proposed project we will follow the innovative idea to restore wild-type C/EBP Alpha function by replacing downstream microRNAs and thus mimicking “C/EBP Alpha-ness”, instead of "Fixing" C/EBP Alpha itself. We plan to identify further C/EBP Alpha-induced microRNAs using a global next-generation sequencing screen in CEBPA knock-out (KO) mice, and, additionally, AML patient samples with C/EBP Alpha-mutations. We will combine the previously discovered microRNAs miR-223, miR-34a and miR-30c with further microRNAs downregulated in CEBPA KO mice from our preliminary data into a cocktail we have called "Alpha MicroRNA Group 2016" (AMG-16). Utilizing PEI nanoparticles as a highly efficient and non-toxic delivery system we will test our cocktail in various in vitro AML cell lines and AML patient sample models. In addition, in vivo mouse models, such as C/EBP alpha KO mice and NSG mice with AML patient derived xenografts (PDX) cells will further bridge the gap between research and clinic. Subsequently, the microRNAs will be functionally investigated and their biological role analyzed. The specific aims are: 1. Identification and charaterization of C/EBPα-induced microRNAs in vitro and in vivo; 2. Development of a C/EBP alpha replacement therapy by microRNA mimics in AML model systems in vitro; 3. Development of a C/EBP alpha replacement therapy by microRNA mimics in AML model systems in vivo. We hypothesize that multiple mimics will show an additive therapeutic effect in comparison to single mimic therapy. Taken together, we will establish a novel C/EBP alpha replacement therapy by microRNA mimics in AML. Thereby, we attempt to establish the basis for a new therapeutic strategy to clinically enhance AML treatment success.

急性髓性白血病（acute myeloid leukemia，简称AML）是一种造血系统的恶性疾病，患者的预后仍然很差。转录因子C/EBP α在骨髓祖细胞的正常分化和随后的细胞死亡中起重要作用。在超过50%的AML病例中发现C/EBP α通过不同机制失活，例如在10%的病例中通过CEBPA基因的失活突变。这导致分化受阻和未成熟胚细胞的积累。因此，在治疗上重新激活AML中的C/EBP α功能将是有利的，从而迫使AML母细胞正常分化并死亡。MicroRNA是一类小的非编码RNA，被鉴定为正常造血和AML发展的重要调节因子。我们先前已经证明C/EBPα诱导microRNA miR-223、miR-34 a和miR-30 c，这些在C/EBP α突变的AML中下调。在这个拟议的项目中，我们将遵循创新的想法，通过替换下游microRNA来恢复野生型C/EBP Alpha功能，从而模仿“C/EBP Alpha”，而不是“固定”C/EBP Alpha本身。我们计划在CEBPA敲除（KO）小鼠中使用全球下一代测序筛选进一步鉴定C/EBP α诱导的microRNA，此外，还包括C/EBP α突变的AML患者样本。我们将联合收割机将先前发现的microRNA miR-223、miR-34 a和miR-30 c与我们初步数据中CEBPA KO小鼠中下调的其他microRNA组合成我们称为“Alpha MicroRNA Group 2016”（AMG-16）的混合物。利用PEI纳米颗粒作为一种高效无毒的递送系统，我们将在各种体外AML细胞系和AML患者样本模型中测试我们的混合物。此外，体内小鼠模型，如C/EBP α KO小鼠和具有AML患者来源的异种移植物（PDX）细胞的NSG小鼠，将进一步弥合研究与临床之间的差距。随后，将对microRNA进行功能研究并分析其生物学作用。具体目标是：1. C/EBPα诱导的microRNA在体内外的鉴定和表征; 2.在体外AML模型系统中通过microRNA模拟物开发C/EBP α替代疗法; 3.在体内AML模型系统中通过microRNA模拟物开发C/EBP α替代疗法。我们假设，与单一模拟疗法相比，多种模拟疗法将显示出相加的治疗效果。综上所述，我们将通过microRNA模拟物在AML中建立一种新的C/EBP α替代疗法。因此，我们试图建立一个新的治疗策略的基础，以提高临床AML治疗的成功率。