[Roles of tyrosine phosphorylation in the proliferation of leukemic hematopoietic stem cells--analysis using a tyrosine phosphatase inhibitor].
I investigated the effects of a tyrosine phosphatase inhibitor, orthovanadate, on the proliferation of normal and CML hematopoietic progenitor cells stimulated by different colony stimulating factors. Orthovanadate decreased CFU-GM colony formation from normal bone marrow cells stimulated by IL-3 and GM-CSF in a dose dependent manner, except for G-CSF. But, BFU-E colony formation was not affected by the treatment with orthovanadate. In CML cells, CFU-GM colony formation was relatively more resistant to orthovanadate than that in normal bone marrow cells and orthovanadate, surprisingly, increased BFU-E colony formation. Western blot analysis showed that preincubation of CML cells with orthovanadate resulted in the enhancement of tyrosine-phosphorylation of p65 mainly, when stimulated with EPO. These results suggest that the second messenger system of IL-3, G-CSF, GM-CSF, and EPO in progenitor cells in CML is different from that in normal progenitor cells and that there is big difference in the second messenger system between myeloid and erythroid progenitor cells in CML cells.
Tanaka
M
M
Third Department of Internal Medicine, Hokkaido University School of Medicine, Sapporo, Japan.
D001854:Bone Marrow Cells; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D016207:Cytokines / Q000502:physiology; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000473:pathology*; D010766:Phosphorylation; D017027:Protein Tyrosine Phosphatases / Q000037:antagonists & inhibitors*; D015398:Signal Transduction; D014638:Vanadates / Q000494:pharmacology*
D016207:Cytokines; D014638:Vanadates; D017027:Protein Tyrosine Phosphatases