The role of AF10 in normal and leukemic hematopoiesis

AF10 在正常和白血病造血中的作用

• 批准号: 8601977
• 负责人: Aniruddha J. Deshpande
• 金额: $ 8.86万
• 依托单位: SLOAN-KETTERING INST CAN RESEARCH
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-11-08 至 2014-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8601977
• 关键词: role; AF10; normal; leukemic; hematopoiesis

DESCRIPTION (provided by applicant): The overall goal of this project is to offer novel insights into the mechanisms of epigenetic deregulation in hematological malignancies that may lead to improved therapeutic strategies. Leukemias bearing chromosomal rearrangements of the AF10 transcription factor are marked by specific perturbations of chromatin 1-3, thereby providing an excellent model for the study of epigenetic deregulation in oncogenesis. We hypothesize that epigenetic dysregulation in the AF10 leukemias results from the loss of the N-terminal PHD domains of AF10 and the retention of the C-terminal octapeptide motif-leucine zipper (OM-LZ) domain in oncogenic AF10 fusions. Our preliminary observations show that transformation by AF10 fusion oncogenes can be suppressed by inhibiting the activity of the AF10 OM-LZ domain or alternatively, by restoring the PHD zinc finger domain in oncogenic AF10 fusions. These observations hold great therapeutic promise for the AF10 leukemias. In Specific Aim 1, we propose to identify mechanisms that lead to tumor suppression using established models of leukemia and knockout mice, followed by high throughput approaches. The clinical relevance of these studies is borne out by the fact that AF10 is involved in recurrent chromosomal translocations in a wide variety of hematological malignancies 4-8. Moreover, several other cancers share features common to the AF10 leukemias, notably - involvement of PHD domains 9-12 or the histone methyltransferase DOT1L 13 together with deregulation of the developmentally critical HOX genes 14, 15. The proposed studies may therefore yield valuable insights into common mechanisms of HOX gene deregulation in cancer. Our preliminary results support a role for AF10 in the regulation of mammalian HOX genes. Deregulation of this function seems to be a critical event in oncogenesis of AF10 leukemias. Therefore, to gain insights into the role of AF10 in normal and leukemic hematopoiesis, we propose to identify the role of AF10 in normal and leukemic hematopoiesis using biochemical and gene-targeting approaches. Specifically, we plan to characterize the transcriptional activity of AF10 and establish conditional knockout mice with hematopoietic specific deletions of AF10 in Specific Aim 2. Prior studies support a role for AF10 in the regulation of HOX genes 1, 2, 16, 17. Establishment of AF10 knockout mice will enable assessment of AF10 function including potential regulation of HOX genes that have important roles in normal and malignant hematopoiesis. Since the AF10-DOT1L network is a valuable therapeutic target, identification of components of this network may provide critical information for its potential pharmacologic inhibition. The proposed project will be carried out in a rich academic institutional environment, and will be guided a mentoring committee composed of renowned scientists. The proposal is supported by a strong training component that includes didactic and practical instruction in epigenetics and hematopathology, training in the responsible conduct of research, and acquisition of mentoring abilities for successfully transitioning to an independent investigator.

描述（由申请人提供）：该项目的总体目标是提供血液恶性肿瘤表观遗传失调机制的新见解，这可能导致改善治疗策略。携带AF 10转录因子的染色体重排的白血病以染色质1-3的特异性扰动为标志，从而为研究肿瘤发生中的表观遗传失调提供了极好的模型。我们推测AF 10白血病的表观遗传失调是由于AF 10 N端PHD结构域的丢失和致癌AF 10融合体中C端八肽基序亮氨酸拉链（OM-LZ）结构域的保留。我们的初步观察结果表明，通过抑制AF 10 OM-LZ结构域的活性，或者通过恢复致癌AF 10融合体中的PHD锌指结构域，可以抑制AF 10融合癌基因的转化。这些观察结果为AF 10白血病提供了巨大的治疗前景。在具体目标1中，我们建议使用已建立的白血病和基因敲除小鼠模型，然后采用高通量方法来确定导致肿瘤抑制的机制。这些研究的临床相关性得到了以下事实的证实：AF 10参与多种血液恶性肿瘤4-8中的复发性染色体易位。此外，其他几种癌症与AF 10白血病具有共同的特征，特别是涉及PHD结构域9-12或组蛋白甲基转移酶DOT 1 L 13以及发育关键HOX基因的失调14，15。因此，拟议的研究可能会产生有价值的见解HOX基因失调在癌症中的常见机制。我们的初步结果支持AF 10在哺乳动物HOX基因的调节中的作用。这种功能的失调似乎是AF 10白血病肿瘤发生的关键事件。因此，为了深入了解AF 10在正常和白血病造血中的作用，我们建议使用生物化学和基因靶向方法来确定AF 10在正常和白血病造血中的作用。具体而言，我们计划表征AF 10的转录活性，并建立具有造血特异性缺失的AF 10特异性目标2的条件性基因敲除小鼠。先前的研究支持AF 10在HOX基因1、2、16、17的调节中的作用。AF 10基因敲除小鼠的建立将能够评估AF 10功能，包括在正常和恶性造血中具有重要作用的HOX基因的潜在调节。由于AF 10-DOT 1 L网络是一个有价值的治疗靶点，因此该网络组分的鉴定可能为其潜在的药理学抑制提供关键信息。拟议的项目将在一个丰富的学术机构环境中进行，并将由著名科学家组成的指导委员会指导。该提案得到了强有力的培训部分的支持，其中包括表观遗传学和血液病理学的教学和实践指导，负责任地开展研究的培训，以及成功过渡到独立研究者的指导能力的获得。