title: JAK kinases overexpression promotes in vitro cell transformation.
abstract: Constitutive activation of the JAK-STAT pathway is frequent in cancer and contributes to oncogenesis. Here, we took advantage of the Ba/F3 cell line, a murine proB cell line dependent on IL-3 for growth, to analyse mechanisms of constitutive STAT activation in vitro. Cytokine-independent and tumorigenic Ba/F3 cell lines were derived from a two-step selection process. Cells transfected with a defective IL-9 receptor acquire IL-9 responsiveness during a first step of selection, and progress after a second selection step to autonomously growing tumorigenic cells. Microarray analysis pointed to JAK1 overexpression as a key genetic event in this transformation. Overexpression of JAK1 not only increased the sensitivity to IL-9 but also allowed a second selection step toward cytokine-independent growth with constitutive STAT activation. This progression was dependent on a functional FERM and kinase JAK1 domain. Similar results were observed after JAK2, JAK3 and TYK2 overexpression. All autonomous cell lines showed an activation of STAT5, ERK1-2 and AKT but only TYK2-overexpressing cell lines showed a constitutive activation of STAT3. Thus, JAK overexpression can be considered as one of the oncogenic events leading to the constitutive activation of the JAK-STAT pathway.
authors.affiliation: Ludwig Institute for Cancer Research, Brussels Branch, Brussels, Belgium.
authors.forename: L
authors.initials: L
authors.lastname: Knoops
authors.forename: T
authors.initials: T
authors.lastname: Hornakova
authors.forename: Y
authors.initials: Y
authors.lastname: Royer
authors.forename: S N
authors.initials: SN
authors.lastname: Constantinescu
authors.forename: J-C
authors.initials: JC
authors.lastname: Renauld
mesh_terms: D000818:Animals; D015153:Blotting, Western; D049109:Cell Proliferation; D002470:Cell Survival; D002471:Cell Transformation, Neoplastic / Q000378:metabolism*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D006801:Humans; D016906:Interleukin-9 / Q000494:pharmacology; D053613:Janus Kinase 1 / Q000235:genetics / Q000378:metabolism; D053614:Janus Kinase 2 / Q000235:genetics / Q000378:metabolism; D053616:Janus Kinase 3 / Q000235:genetics / Q000378:metabolism; D053612:Janus Kinases / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D054448:Precursor Cells, B-Lymphoid / Q000378:metabolism / Q000473:pathology*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D053651:Receptors, Interleukin-9 / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050796:STAT3 Transcription Factor / Q000235:genetics / Q000378:metabolism*; D050799:STAT5 Transcription Factor / Q000378:metabolism; D015398:Signal Transduction; D053634:TYK2 Kinase / Q000235:genetics / Q000378:metabolism
chemical_list: D016906:Interleukin-9; D053651:Receptors, Interleukin-9; D050796:STAT3 Transcription Factor; D050799:STAT5 Transcription Factor; C507933:JAK3 protein, human; C507905:Jak1 protein, mouse; C507926:Jak2 protein, mouse; D053613:Janus Kinase 1; D053614:Janus Kinase 2; D053616:Janus Kinase 3; D053612:Janus Kinases; D053634:TYK2 Kinase; C070139:TYK2 protein, human; D051057:Proto-Oncogene Proteins c-akt; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3