C/EBPalpha-mediated therapy for acute myeloid leukemia

描述(由申请人提供)： 转录因子C/EBPA是中性粒细胞分化的必要条件和充分条件。在许多急性髓系白血病(AML)患者中，发现C/EBPalpha的表达和/或功能受到各种机制的干扰。因此，C/EBPA在白血病细胞中的条件性表达重建了它们的中性粒细胞分化。该方案通过两种途径为AML提供了新的C/EBPalpha介导的转录治疗方法。在一种方法中，将利用非侵入性的方式将功能性C/EBPA蛋白送入病变细胞的细胞核。将细胞通透性多肽与C/EBPA蛋白进行框架融合，在真核细胞中表达。细胞内蛋白的转运将通过生产细胞系与受体细胞的共培养，或通过将纯化的细胞可渗透C/EBPA蛋白提供到受体细胞的培养液中来实现。优化的程序将应用于原代白血病骨髓细胞。C/EBPA蛋白传递的预期效果，如诱导分化和凋亡，将被监测。在第二种方法中，发展了一种基于细胞的快速和可重复的小分子化学物质的高通量筛选。简而言之，建立了一条稳定的指示线，该指示线含有C/EBP反应元件调控的荧光素酶基因。荧光素酶活性的增加可能是由于C/EBPA表达和/或功能的增强所致。将对活性化合物进行鉴定和研究，以确定其作用机制。虽然这项建议的重点是开发AML的新疗法，但成功的C/EBPA靶向疗法也可能用于治疗对干扰素或ST1571无效的CML。申请者拥有进行这些实验所需的相当多的技能。然而，拟议的职业发展计划的完成将进一步扩大她的研究经验，并使她能够追求独立的研究生涯。

DESCRIPTION (provided by applicant): The transcription factor C/EBPa is necessary and sufficient for neutrophil differentiation. Expression and/or function of C/EBPalpha were found to be perturbed by various mechanisms in many cases of acute myeloid leukemia (AML). Consequently, conditional expression of C/EBPa in leukemic cells re-established their neutrophilic differentiation. This proposal offers novel C/EBPalpha-mediated transcriptional therapies for AML by two approaches. In one, noninvasive delivery of functional C/EBPa protein into nuclei of diseased cells will be utilized. Cell permeable peptides will be fused in frame with C/EBPa protein and expressed in eukaryotic cells. Intracellular protein transport will be achieved through co-culture of the producer cell line with the recipient cells, or by supplying the purified cell permeable C/EBPa proteins into culture media of the recipient cells. Optimized procedure will be applied to primary leukemic bone marrow cells. The expected effects of C/EBPa protein delivery, such as induction of differentiation and apoptosis, will be monitored. In the second approach, a rapid and reproducible cell-based high throughput screen of small molecule chemicals was developed. Briefly, a stable indicator line was made, which harbors luciferase gene under the control of C/EBP-responsive element. Increase in luciferase activity will likely result from augmentation of C/EBPa expression and/or function. Active compounds will be identified and studied to determine the mechanisms of their action. Although this proposal is focused on development of new therapies for AML, successful C/EBPa targeting therapies might be also used for treatment of CML refractory to interferon` or ST1571. The applicant has considerable skills necessary to perform these experiments. Nevertheless, completion of the proposed career development program will further expand her research experience and will enable her to pursue an independent research career.