STAT3-mediated differentiation and survival and of myeloid cells in response to granulocyte colony-stimulating factor: role for the cyclin-dependent kinase inhibitor p27(Kip1).
The signal transducer and activator of transcription (STAT) proteins have been implicated in cytokine-regulated proliferation, differentiation and cell survival. Granulocyte colony-stimulating factor (G-CSF), a regulator of granulocytic differentiation, induces a robust and sustained activation of STAT3. Here, we show that introduction of dominant negative (DN) forms of STAT3 interferes with G-CSF-induced differentiation and survival in murine 32D cells. G-CSF induces expression of the cyclin-dependent kinase (cdk) inhibitor p27(KiP1) (but not p21(CiP1)), which is completely blocked by DN-STAT3. The ability of tyrosine-to-phenylalanine substitution mutants of the G-CSF receptor to activate STAT3 strongly correlated with their capacity to induce p27 expression and their ability to mediate differentiation and survival, suggesting a causal relationship between STAT3 activation, p27 expression and the observed cellular responses. We identified a putative STAT binding site in the promoter region of p27 that showed both STAT3 binding in electrophoretic mobility shift assays and functional activity in luciferase reporter assays. Finally, we studied G-CSF-induced responses in primary bone marrow and spleen cells of p27-deficient mice. Compared with wild-type, myeloid progenitors from p27-deficient mice showed significantly increased proliferation and reduced differentiation in response to G-CSF. These findings indicate that STAT3 controls myeloid differentiation, at least partly, via upregulation of p27(Kip1).
de Koning
J P
JP
Institute of Hematology, Erasmus University, Rotterdam, The Netherlands.
Soede-Bobok
A A
AA
Ward
A C
AC
Schelen
A M
AM
Antonissen
C
C
van Leeuwen
D
D
Löwenberg
B
B
Touw
I P
IP
D000818:Animals; D001665:Binding Sites; D018797:Cell Cycle Proteins; D002454:Cell Differentiation; D002455:Cell Division; D002470:Cell Survival; D050760:Cyclin-Dependent Kinase Inhibitor p27; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004791:Enzyme Inhibitors; D015870:Gene Expression; D016179:Granulocyte Colony-Stimulating Factor / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008024:Ligands; D051379:Mice; D018345:Mice, Knockout; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000502:physiology*; D016296:Mutagenesis; D009504:Neutrophils / Q000166:cytology; D011401:Promoter Regions, Genetic; D050796:STAT3 Transcription Factor; D013234:Stem Cells / Q000166:cytology; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins
C493961:Cdkn1b protein, mouse; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D008024:Ligands; D008869:Microtubule-Associated Proteins; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; C494087:Stat3 protein, mouse; D015534:Trans-Activators; D025521:Tumor Suppressor Proteins; D016179:Granulocyte Colony-Stimulating Factor; D050760:Cyclin-Dependent Kinase Inhibitor p27; D018844:Cyclin-Dependent Kinases