| Project/Area Number |
12670980
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Hematology
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| Research Institution | Hamamatsu University School of Medicine |
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Principal Investigator |
OHNISHI Kazunori School of Medicine, Hamamatsu University School of Medicine Associate professor, 医学部, 助教授 (80252170)
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| Co-Investigator(Kenkyū-buntansha) |
YOSHIDA Hitoshi School of Medicine, Hamamatsu University School of Medicine Instructor, 医学部, 助手 (30303548)
TAKESHITA Akihiro School of Medicine, Hamamatsu University School of Medicine Associate professor, 医学部, 助教授 (00242769)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2001: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2000: ¥2,600,000 (Direct Cost: ¥2,600,000)
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| Keywords | myelodysplastic syndrome / gene therapy / granulocyte colony-stimulating factor receptor / retroviral vector / granulocytic differentiation / SH-PTP1 / 遺伝子導入 / チロシンリン酸化酵素 / エリスロポエチン受容体遺伝子 / トロンポボエチン受容体遺伝子 |
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| Research Abstract |
Myelodysplastic syndrome (MDS) are clonal disorders in which the proper differentiation of hematopoietic stem cells is impaired. There is no effective treatment for this stem cell disorder at present. In an attempt to find a new strategy that promotes the differentiation of MDS blast cells, we tried retroviral transduction of granulocyte colony-stimulating factor receptor (G-CSFR) into an interleukin-3-dependent MDS cell line, MDS-L. Ectopic expression of human G-CSFR cDNA in MDS-L cells gave rise to granulocytic differentiation by G-CSF stimulation. G-CSF caused the transformants expressing G-CSFR to display a morphological characteristics of mature granulocytes. These results demonstrate that MDS-L cells ectopically expressing G-CSFR are induced to granulocytic differentiation upon exposure to G-CSF.
Next, we showed that SH-PTP1 bound selectively to phosphorylated tyrosine at 729 ammo1"acid position (pY729) in the cytoplasmic domain of G-CSFR through its SH2 domain. This interaction mediated the dephosphorylation and inactivation of JAK2. Recruitment of SH-PTP1 to G-CSFR containing pY729, induced by G-CSF binding, caused dephosphorylation of JAK2. Compared to wild-type G-CSFR transfectants, stable transfectants of a mutant G-CSFR lacking Y729 allowed proliferation of cells at the one-fourth concentration of G-CSF and remarkably prolonged hyperphosphorylation of both JAK2 and G-CSFR. We conclude that SH-PTP1 play an important role in down-modulation of proliferation signals generated by the activated G-CSFR/JAK2 complexes.
Our experimental design provides new insight into the strategy of gene therapy for hamatologic disorders by retrovirus-mediated gene transfer.
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