Identification and Characterization of Genes that Suppress BCR-ABL+ Leukemia

抑制 BCR-ABL 白血病的基因的鉴定和表征

• 批准号: 8578767
• 负责人: MICHAEL R GREEN
• 金额: $ 34.55万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-11 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8578767
• 关键词: Acute Lymphocytic Leukemia; Adult Acute Lymphocytic Leukemia; Affect; BRAF gene; Biological Assay; CBFB gene; CDKN2A gene; Cancer Etiology; Cell Culture Techniques; Cell Proliferation; Cells; Chimeric Proteins; Chromosome abnormality; Chromosomes; Chromosomes, Human, Pair 9; Chronic Myeloid Leukemia; Cultured Cells; Dasatinib; Development; Disease Progression; Drug resistance; Drug usage; Epigenetic Process; Fibroblasts; Gene Silencing; Generations; Genes; Genetic; Goals; Hematopoietic; Human; Imatinib; In Vitro; MYH11 gene; Mediating; Modeling; Mus; Mutation; Myeloid Progenitor Cells; Neoplastic Cell Transformation; Oncogenes; Oncogenic; Pathway interactions; Patients; Phosphotransferases; Play; RB1 gene; RNA Interference; RUNX1 gene; Regulatory Pathway; Resistance; Resistance development; Risk; Role; Series; Solid Neoplasm; Suppressor Genes; TP53 gene; Testing; Therapeutic Intervention; Tumor Suppressor Genes; Tumor Suppressor Proteins; Tyrosine Kinase Inhibitor; base; bcr-abl Fusion Proteins; fusion gene; improved; inhibitor/antagonist; insight; leukemia; leukemogenesis; loss of function; mouse model; prevent; progenitor; public health relevance; research study; resistance mechanism; response; senescence; small hairpin RNA; tumorigenesis

DESCRIPTION (provided by applicant): Certain oncogenes that promote solid tumors, such as RAS and BRAF, induce senescence when expressed in primary cells. Oncogene-induced senescence plays an important role in suppressing tumorigenesis by preventing proliferation of cells at risk for neoplastic transformation. Thus, in many instances, genes involved in oncogene-induced senescence, such as TP53 and RB1, are also tumor suppressors. BCR-ABL is an oncogenic kinase derived from the translocation between chromosomes 9 and 22 that can transform myeloid progenitor cells and drives the development of the vast majority chronic myeloid leukemia (CML) cases and 20%-30% of adult acute lymphoblastic leukemia (ALL) cases. We have recently found that BCR-ABL, as well as two other leukemogenic fusion-proteins, CBFB-MYH11 and RUNX1-ETO, can, like RAS and BRAF, induce senescence in primary human fibroblasts and hematopoietic progenitors. Our results imply that the development of BCR-ABL+ leukemias involves genetic and/or epigenetic alterations that inactivate one or more senescence-promoting genes. Consistent with this hypothesis, inactivation of genes known to promote senescence, such as TP53 and CDKN2A (p16INK4a/p14ARF), can cooperate with BCR-ABL in mouse models of CML, and CDKN2A deletions are frequently found in patients with BCR-ABL+ ALL. Significantly, these same genetic alterations can also confer resistance to imatinib, an inhibitor of BCR-ABL kinase activity that is the first-line treatment for CML. Thus, delineating the genes and regulatory pathways by which BCR-ABL induces senescence in primary cells will help identify genetic alterations that cooperate with BCR-ABL to promote leukemogenesis and are responsible for the emergence of imatinib resistance. Toward this long-term objective, we have carried out a large-scale RNA interference screen to identify genes whose knockdown enables primary cells to overcome BCR-ABL-induced senescence. These genes represent candidate suppressors of BCR-ABL+ leukemias. In this application, we propose experiments involving both cultured cells and mouse models of CML and ALL to determine the role of these candidates in suppression of BCR-ABL+ leukemias. The confirmed leukemia suppressor genes will be further studied to gain insights into how they promote senescence and to identify the regulatory pathways in which they function. Finally, confirmed leukemia suppressor genes will be tested for a role in the development of resistance to imatinib as well as dasatinib, the major second-generation tyrosine kinase inhibitor. The results of these experiments will improve our understanding of BCR-ABL+ leukemia development, reveal potential new targets for therapeutic intervention, and help predict patient responsiveness to treatment.

描述（由申请人提供）：某些促进实体瘤的癌基因，如RAS和BRAF，在原代细胞中表达时诱导衰老。癌基因诱导的衰老通过阻止处于肿瘤转化风险的细胞增殖在抑制肿瘤发生中起重要作用。因此，在许多情况下，参与癌基因诱导衰老的基因，例如TP 53和RB 1，也是肿瘤抑制因子。 BCR-ABL是一种致癌激酶，来源于9号和22号染色体之间的易位，可以转化髓系祖细胞，并驱动绝大多数慢性髓系白血病（CML）病例和20%-30%的成人急性淋巴细胞白血病（ALL）病例的发展。我们最近发现，BCR-ABL，以及其他两种致白血病融合蛋白，CBFB-MYH 11和RUNX 1-ETO，可以像RAS和BRAF一样诱导原代人成纤维细胞和造血祖细胞的衰老。我们的研究结果表明，BCR-ABL+白血病的发展涉及遗传和/或表观遗传改变，包括一个或多个衰老促进基因。与这一假设一致，已知促进衰老的基因（如TP 53和CDKN 2A（p16 INK 4a/p14 ARF））的失活可以在CML小鼠模型中与BCR-ABL协同作用，并且CDKN 2A缺失经常在BCR-ABL+ ALL患者中发现。值得注意的是，这些相同的遗传改变也可以赋予对伊马替尼的抗性，伊马替尼是一种BCR-ABL激酶活性抑制剂， CML的一线治疗因此，描述BCR-ABL诱导原代细胞衰老的基因和调控途径将有助于确定与BCR-ABL合作促进白血病发生并导致伊马替尼耐药的遗传改变。 为了实现这一长期目标，我们进行了大规模的RNA干扰筛选，以确定基因的敲低，使原代细胞克服BCR-ABL诱导的衰老。这些基因代表BCR-ABL+白血病的候选抑制因子。在本申请中，我们提出了涉及CML和ALL的培养细胞和小鼠模型的实验，以确定这些候选物在抑制BCR-ABL+白血病中的作用。已证实的白血病抑制基因将被进一步研究，以深入了解它们如何促进衰老，并确定它们发挥作用的调控途径。最后，将检测已确认的白血病抑制基因在伊马替尼和达沙替尼（主要的第二代酪氨酸激酶抑制剂）耐药性发展中的作用。这些实验的结果将提高我们对BCR-ABL+白血病发展的理解，揭示治疗干预的潜在新靶点，并帮助预测患者对治疗的反应性。