STAT5 activation is required for interleukin-9-dependent growth and transformation of lymphoid cells.
Interleukin-9 (IL-9) is a growth factor for T cells and various hematopoietic and lymphoid tumor cells. IL-9 signaling involves activation of Janus kinase (JAK)1 and JAK3 kinases, and signal transducer and activator of transcription (STAT)1, STAT3 and STAT5. Using a dominant negative form of STAT5 (STAT5delta), we demonstrated that this factor is an important mediator of IL-9-dependent Ba/F3 cell growth. Mutation of the STAT binding site of the IL-9 receptor (tyr116phe) results in an important decrease in STAT activation and inhibition of proliferation in the presence of IL-9. A small number of cells escape this inhibition, and IL-9-dependent cell lines could be derived. The selected cells required activation of STAT5 for growth, which was blocked by STAT5delta expression and enhanced by overexpression of wild-type STAT5. In contrast to parental cells, Ba/F3-Phe116 cells growing in the presence of IL-9 further progress to cytokine-independent tumorigenic clones. These tumorigenic clones exhibited a strong cytokine-independent activation of JAK1 and STAT5, which most likely supports their proliferation. Transfection of a constitutively activated variant of STAT5 promoted the growth of wild-type Ba/F3 cells in the absence of cytokine. Finally, the expression of the proto-oncogene pim-1 was correlated with STAT5 activation and cell growth. Our data suggest that STAT5 is an important mediator of IL-9-driven proliferation and that dysregulation of STAT5 activation favors tumorigenesis of lymphoid cells.
Ludwig Institute for Cancer Research, Université Catholique de Louvain, Brussels, Belgium. Jean-Baptiste.Demoulin@bru.licr.org
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JB
Demoulin
C
C
Uyttenhove
D
D
Lejeune
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A
Mui
B
B
Groner
J C
JC
Renauld
D000818:Animals; D001665:Binding Sites; D016466:CHO Cells; D002455:Cell Division / Q000187:drug effects / Q000235:genetics; D002471:Cell Transformation, Neoplastic / Q000187:drug effects / Q000235:genetics; D006224:Cricetinae; D018076:DNA, Complementary / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D005260:Female; D006801:Humans; D016906:Interleukin-9 / Q000378:metabolism*; D053613:Janus Kinase 1; D053614:Janus Kinase 2; D008214:Lymphocytes / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D016513:Mice, SCID; D008894:Milk Proteins; D009154:Mutation; D009368:Neoplasm Transplantation; D010957:Plasmids; D011233:Precipitin Tests; D017346:Protein Serine-Threonine Kinases; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051573:Proto-Oncogene Proteins c-pim-1; D050799:STAT5 Transcription Factor; D013752:Tetracycline / Q000494:pharmacology; D013997:Time Factors; D015534:Trans-Activators / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D014407:Tumor Cells, Cultured
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D016906:Interleukin-9; C000715470:MAS1 protein, human; D008894:Milk Proteins; D011500:Protein Synthesis Inhibitors; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D050799:STAT5 Transcription Factor; D015534:Trans-Activators; D011505:Protein-Tyrosine Kinases; C507904:JAK1 protein, human; C507924:JAK2 protein, human; C507905:Jak1 protein, mouse; C507926:Jak2 protein, mouse; D053613:Janus Kinase 1; D053614:Janus Kinase 2; C496634:PIM1 protein, human; C496636:Pim1 protein, mouse; D017346:Protein Serine-Threonine Kinases; D051573:Proto-Oncogene Proteins c-pim-1; D013752:Tetracycline