Molecular and Cellular Characterization of Myeloprolife*

骨髓增生性疾病（MPD）代表血液和骨骼中骨髓细胞的异常增殖 干细胞是一种重要的细胞，是一种重要的细胞。“尽管MPD的病理分类 虽然最近才定义，但疾病的分子发病机制还没有很好地理解。大多数个体 诊断为MPD的患者死于进行性血细胞减少（出血）的并发症 或感染）或转化为急性白血病。因此，我们必须确定替代方案， 治疗MPD的方法我们产生了CREB转基因小鼠，其中cAMP反应元件 结合蛋白（CREB）在髓系中表达。这些小鼠出现单核细胞增多症， 脾肿大和MPD在骨髓集落测定中，我们观察到增殖、生长因子 独立性，以及用来自CREB转基因小鼠的骨髓的第三次再接种进行胚细胞转化。 CREB转基因小鼠骨髓移植导致骨髓增强 移植和增加干细胞数量。CREB在造血细胞中过表达， MPD患者在这个建议中，我们假设CREB转基因小鼠是人类的模型， CREB在调节干细胞自我更新和可能的急性转化中起作用。 白血病为了检验这些假设，我们将：1）表征hMRP 8-CREB中的MPD表型 2）表征CREB过表达在造血干细胞中的生物学和细胞效应; 干细胞;和3）表征CREB与MPD中其他癌基因的合作。具体目标1、 我们将研究CREB中MPD的时间进程、免疫表型、集落形成和发展 转基因小鼠。我们还将把我们的发现与人类疾病联系起来。在第二阶段，我们将 研究CREB在原代干细胞中过表达的表型。我们会用骨髓 在不同分化阶段用CREB逆转录病毒或慢病毒感染祖细胞， CREB在体内外对干细胞增殖和分化的影响。因为30%的患者 MPD有ras突变，我们将用CREB逆转录病毒从K-rasG 12 D小鼠骨髓中扩增， 检查集落形成、免疫表型、植入和向AML的潜在转化。这些 研究将为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.