| Co-Investigator(Kenkyū-buntansha) |
MATSUMURA Itaru Osaka University, Graduate School of Medicine, Associate Professor (00294083)
MIZUKI Masao Osaka University, Hospital, Associate Professor (80283761)
ORITANI Kenji Osaka University, Graduate School of Medicine, Associate Professor (70324762)
SHIBAYAMA Hirohiko Osaka University, Graduate School of Medicine, Assistant Professor (60346202)
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| Budget Amount *help |
¥45,110,000 (Direct Cost: ¥34,700,000、Indirect Cost: ¥10,410,000)
Fiscal Year 2007: ¥16,380,000 (Direct Cost: ¥12,600,000、Indirect Cost: ¥3,780,000)
Fiscal Year 2006: ¥28,730,000 (Direct Cost: ¥22,100,000、Indirect Cost: ¥6,630,000)
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| Research Abstract |
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.
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