Differentiation of various leukemic cells can be induced by liganded retinoic acid receptors and protein phosphatase inhibitors. In this study, we explored the effects of okadaic acid (OA), the phosphatase inhibitor, and retinoic acid (RA) in v-myb-transformed monoblasts BM2. OA induced differentiation of BM2 monoblasts into macrophage-like cells, as documented by analyses of cell morphology, cell cycle, phagocytic activity, non-specific esterase activity, production of reactive oxygen species and expression of vimentin and Mo-1. In contrast to many other leukemic cell lines, BM2 cells do not respond to retinoic acid. However, once exposed to OA and RA simultaneously, BM2 cells differentiate along monocyte/macrophage pathway more efficiently. We conclude that RA enhances differentiation of v-myb-transformed monoblasts induced by protein phosphorylation.
- MeSH
- aktivace transkripce účinky léků MeSH
- buněčná diferenciace účinky léků MeSH
- financování organizované MeSH
- geny myb MeSH
- imunoblotting MeSH
- kur domácí MeSH
- kyselina okadaová farmakologie MeSH
- leukemie metabolismus MeSH
- makrofágy cytologie účinky léků MeSH
- monocyty cytologie účinky léků MeSH
- nádorové buněčné linie MeSH
- protinádorové látky farmakologie MeSH
- transfekce MeSH
- transformované buněčné linie MeSH
- tretinoin farmakologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
Maturation of blood cells depends on dramatic changes of expression profiles of specific genes. Although these changes have been extensively studied, their functional outcomes often remain unclear. In this study, we explored the identity and function of an unknown protein that was greatly overexpressed in v-myb-transformed BM2 monoblasts undergoing differentiation to macrophage-like cells. We identified this protein as vimentin, the intermediate filament protein. We show that an increased level of vimentin protein results from activation of the vimentin gene promoter occurring in monoblastic cells induced to differentiate by multiple agents. Furthermore, our studies reveal that the vimentin gene promoter is stimulated by Myb and Jun proteins, the key transcriptional regulators of myeloid maturation. Silencing of vimentin gene expression using siRNA markedly suppressed the ability of BM2 cells to form macrophage polykaryons active in phagocytosis and producing reactive oxygen species. Taken together, these findings document that up-regulation of vimentin gene expression is important for formation of fully active macrophage-like cells and macrophage polykaryons.
- MeSH
- 2D gelová elektroforéza MeSH
- buněčná diferenciace MeSH
- fibroblasty MeSH
- financování organizované MeSH
- geny jun genetika MeSH
- hematopoéza genetika MeSH
- hmotnostní spektrometrie MeSH
- křepelky a křepelovití MeSH
- kur domácí MeSH
- makrofágy cytologie fyziologie MeSH
- monocyty cytologie fyziologie MeSH
- onkogenní proteiny v-myb genetika MeSH
- promotorové oblasti (genetika) imunologie MeSH
- protoonkogenní proteiny c-jun fyziologie MeSH
- regulace genové exprese MeSH
- tetradekanoylforbolacetát MeSH
- transformované buněčné linie MeSH
- transkripční faktory genetika MeSH
- upregulace MeSH
- vimentin fyziologie genetika MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- MeSH
- buněčná diferenciace fyziologie genetika MeSH
- fagocytóza imunologie účinky záření MeSH
- finanční podpora výzkumu jako téma MeSH
- geny myb genetika MeSH
- hematopoéza genetika MeSH
- makrofágy MeSH
- nádorová transformace buněk genetika MeSH
- regulace genové exprese imunologie účinky záření MeSH
- vimentin fyziologie genetika MeSH
