Synthetic Analysis on the mechanisms of survival and differentiation of hematopoietic cells

1.虽然白血病酪氨酸激酶激活共同的下游分子，白血病的表型所造成的这些LTKs是不同的。本研究利用F1 P1 L1-PDGFRα（F-PRα）基因分析其机制。当引入c-Kit^<high>Sca-1^+谱系细胞（KSL）时，F-PR α而不是TEL-PDGFRβ（T-PRβ）增强了Gr-1^&lt;+&gt;IL-5 R α^&lt;+&gt;嗜酸性粒细胞祖细胞（EoP）的发育。此外，F-PR α促进嗜酸性粒细胞从普通髓系祖细胞（CMPs）发育.此外，当F-PR α在巨核细胞/红细胞祖细胞（MEP）和普通淋巴祖细胞（CLP）中表达时，F-PRα异常地从MEP和CLP发育出EoPs。RT-PCR分析表明，F-PRα可增强C/EBPα和加塔-2的表达，降低PU。1表达式。此外，荧光素酶检测结果显示，F-PRα及其下游Ras增强了加塔- 2的活性，而抑制了PU. 1的活性.我们以前克隆了一个新的抗凋亡基因，Anamorsin（AM）。在这项研究中，我们产生了转基因（Tg）小鼠AM。虽然AM Tg小鼠没有自发地发展任何肿瘤，但观察到由于B细胞的生长而导致的显著脾肿大。另外，我们通过免疫组化染色发现AM的表达是弥漫性大B细胞淋巴瘤特殊亚型的不良预后因素.我们建立了一种以人骨髓间充质干细胞（hMSC）为基质，从脐带血中分离纯化人CD 34_+细胞，经体外培养获得B淋巴细胞的长期培养体系。使用这种共培养物，我们可以<5>从2000个CD 34_+细胞中培养出1-5 × 10 ~（-1）CD 10_+细胞。在此系统中，4周后表面IgM+未成熟B细胞开始出现。此外，我们发现激活素A选择性抑制B淋巴细胞的产生。

1. Although leukemogenic tyrosine kinases activate common downstream molecules, the phenotypes of leukemia caused by these LTKs are distinct. In this study, we analyzed its mechanism using F1P1L1-PDGFRα(F-PRα), a causative gene of hypereosinophilic syndrome/chronic eosinophilic leukemia. When introduced into c-Kit^<high>Sca-1^+ Lineage cells (KSLs), F- PRa but not TEL-PDGFRβ (T-PRβ) enhanced the development of Gr-1^<+>IL-5Rα^<+> eosinophil progenitors(EoPs). Also, F- PRα promoted eosinophil development from common myeloid progenitors (CMPs). Furthermore, when expressed in megakaryocyte/erythrocyte progenitors (MEPs) and common lymphoid progenitors (CLPs), F-PRα aberrantly developed EoPs from MEPs and CLPs. Regarding this mechanism, RT-PCR analysis revealed that F-PRα augmented the expression of C/EBPα and GATA-2, while it reduced PU. 1 expression. Furthermore, F-PRα and its downstream Ras enhanced GATA- 2 activity, while they inhibited PU.1 activity in luciferase assays.2. We previously cloned a novel anti-apoptotic gene, Anamorsin(AM). In this study, we generated transgenic(Tg) mice for AM. Although AM Tg mice did not develop any tumors spontaneously, marked splenomegaly due to the outgrowth of B cells was observed. In addition, we found that the expression of AM was a poor prognostic factor for the special subtype of diffuse large B-cell lymphoma using immunohistochemical staining.3. We developed a long-term culture system to produce B lymphocytes from human CD34_+ cells purified from umbilical cord blood using human mesenchymal stem cells (hMSC) as stroma. Using this cocultures, we could develop 1-5 x 10^<5> CD10_+ cells from 2000 CD34_+ cells. In this system, surface IgM_+ immature B cells began to appear after 4 weeks. In addition, we found that Activin A selectively suppressed B lymphocyte production.