Molecular and Cellular Characterization of Myeloprolife*

骨髓增生性疾病(MPD)表现为血液和骨骼中髓系细胞的异常增殖 骨髓，被认为是一种“干细胞疾病”。尽管MPD的病理分类有 最近被定义的疾病的分子发病机制还不是很清楚。大多数个体 被诊断为MPD的患者死于进行性红细胞减少症(出血)的并发症 或感染)或转化为急性白血病。因此，当务之急是我们确定替代方案。 治疗MPD的方法。我们产生了CREB转基因小鼠，在其中cAMP反应元件 结合蛋白(CREB)在髓系细胞中表达。这些小鼠会出现单核细胞增多症， 脾肿大和MPD。在骨髓集落分析中，我们观察到增殖、生长因子增加 CREB转基因小鼠骨髓的无性、原始转化和三次骨髓移植。 CREB转基因小鼠骨髓移植可增强髓系 植入和增加干细胞的数量。CREB在造血细胞中过表达 MPD患者。在这个方案中，我们假设CREB转基因小鼠是人类的模型 MPD和CREB在调节干细胞自我更新和可能的急性转化中发挥作用 白血病。为了验证这些假设，我们将：1)表征hMRP8-CREB中的MPD表型 转基因小鼠；2)CREB在造血系统中过表达的生物学和细胞效应 干细胞；以及3)CREB与其他癌基因在MPD中的协同作用。在具体目标1中， 我们将研究MPD在CREB中的时间进程、免疫表型、集落形成和发展 随着时间的推移，转基因小鼠。我们还将把我们的发现与人类疾病联系起来。在具体目标2中，我们将 研究CREB在原代干细胞中过表达的表型。我们将进行骨髓移植 CREB逆转录病毒或慢病毒在不同分化阶段的祖细胞，并检测 CREB在体内外对干细胞增殖分化的影响由于30%的患者患有 MPD有ras突变，我们将用CREB逆转录病毒转导K-RasG12D小鼠的骨髓，并 检测集落形成、免疫表型、植入和向急性髓系白血病转化的可能性。这些 研究将对导致MPD的分子途径提供新的见解。

Myeloproliferative disease (MPD) represents abnormal proliferation of myeloid cells in the blood and bone marrow, and is considered to be a "stem cell disorder." Although the pathologic classification of MPD has been recently defined, the molecular pathogenesis of disease is not well understood. Most individuals diagnosed with MPD succumb to their disease from either complications of progressive cytopenias (bleeding or infections) or transformation to acute leukemia. Therefore , it is imperative that we identify alternative approaches to treat MPD. We generated CREB transgenic mice in which the cAMP Response Element Binding protein (CREB) is expressed in the myeloid lineage. These mice develop monocytosis, splenomegaly, and MPD. In bone marrow colony assays, we observed increased proliferation, growth factor independence, and blast transformation with tertiary replating of bone marrow from CREB transgenic mice. Bone marrow transplantation with CREB transgenic mouse bone marrow result in enhanced myeloid engraftment and increased numbers of stem cells. CREB is overexpressed in hematopoietic cells from patients with MPD. In this proposal, we hypothesize that the CREB transgenic mouse is a model for human MPD and that CREB plays a role in regulating stem cell self-renewal and possibly transformation to acute leukemia. To test these hypotheses, we will: 1) characterize the MPD phenotype in hMRP8-CREB transgenic mice; 2) characterize the biological and cellular effects of CREB overexpression in hematopoietic stem cells; and 3) characterize the cooperation of CREB with other oncogenes in MPD. In Specific Aim 1, we will study the time course, immunophenotype, colony formation, and development of MPD in CREB transgenic mice over time. We will also correlate our findings with human disease. In Specific Aim 2, we will investigate the phenotype of CREB overexpression in primary stem cells. We will transduce bone marrow progenitor cells with CREB retrovirus or lentivirus at different stages of differentiation and examine the effects of CREB on stem cell proliferation and differentiation in vitro and in vivo. Since 30% of patients with MPD have ras mutations, we will transduce bone marrow from K-rasG12D mice with CREB retrovirus and examine colony formation, immunophenotype, engraftment, and potential transformation to AML. These studies will provide new insights into the molecular pathways leading to MPD.