Interleukin-6 and oncostatin M-induced growth inhibition of human A375 melanoma cells is STAT-dependent and involves upregulation of the cyclin-dependent kinase inhibitor p27/Kip1.
Interleukin-6 (IL-6)-type cytokines lead to growth arrest of human A375 melanoma cells. The present study demonstrates that this effect depends on the activation of STAT transcription factors. We observed a correlation between the extent of growth inhibition exerted by IL-6, IL-6 plus soluble IL-6 receptor or oncostatin M (OSM) and the intensities of STAT3 and STAT1 signals. A truncated chimeric receptor retaining only the membrane-proximal region of gp130, the common signal transducer of IL-6-type cytokines, did neither activate STATs nor mediate growth arrest of stable transfectants. These functions were restored by the addition of short STAT recruitment modules comprising critical tyrosine residues from gp130 (Y767, Y814). A receptor carrying tyrosine module Y759 of gp130 effectively mediated activation of the phosphatase SHP-2 but did not alter cell growth. Overexpression of dominant negative forms of STAT3 but not STAT1 abrogated the inhibitory effect of OSM and IL-6 in A375 cells. In addition, we have identified the cyclin-dependent kinase inhibitor p27/Kipl as a novel target to be regulated by IL-6-type cytokines. Stimulation-dependent upregulation of p27 mRNA occurred STAT3-dependently. Also p27 protein accumulated which coincided with the disappearance of hyperphosphorylated retinoblastoma protein in three human melanoma cell lines sensitive to IL-6-type cytokines.
Department of Biochemistry, RWTH Aachen, Germany.
M
M
Kortylewski
P C
PC
Heinrich
A
A
Mackiewicz
U
U
Schniertshauer
U
U
Klingmüller
K
K
Nakajima
T
T
Hirano
F
F
Horn
I
I
Behrmann
D015703:Antigens, CD / Q000235:genetics / Q000502:physiology; D018797:Cell Cycle Proteins; D002455:Cell Division / Q000187:drug effects; D050760:Cyclin-Dependent Kinase Inhibitor p27; D050822:Cytokine Receptor gp130; D004268:DNA-Binding Proteins / Q000502:physiology*; D004789:Enzyme Activation; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D015850:Interleukin-6 / Q000494:pharmacology*; D047908:Intracellular Signaling Peptides and Proteins; D008545:Melanoma / Q000473:pathology*; D008562:Membrane Glycoproteins / Q000235:genetics / Q000502:physiology; D008869:Microtubule-Associated Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D053683:Oncostatin M; D010455:Peptides / Q000494:pharmacology*; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; D017027:Protein Tyrosine Phosphatases / Q000502:physiology; D012333:RNA, Messenger / Q000096:biosynthesis; D012334:RNA, Neoplasm / Q000096:biosynthesis; D017467:Receptors, Erythropoietin / Q000235:genetics / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000502:physiology; D016160:Retinoblastoma Protein / Q000378:metabolism; D050794:STAT1 Transcription Factor; D050796:STAT3 Transcription Factor; D015398:Signal Transduction / Q000187:drug effects*; D015534:Trans-Activators / Q000502:physiology*; D014162:Transfection; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins
D015703:Antigens, CD; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; C494199:IL6ST protein, human; D015850:Interleukin-6; D047908:Intracellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins; D008869:Microtubule-Associated Proteins; D009363:Neoplasm Proteins; C508351:OSM protein, human; D010455:Peptides; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D017467:Receptors, Erythropoietin; D011993:Recombinant Fusion Proteins; D016160:Retinoblastoma Protein; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D015534:Trans-Activators; D025521:Tumor Suppressor Proteins; D053683:Oncostatin M; D050822:Cytokine Receptor gp130; D050760:Cyclin-Dependent Kinase Inhibitor p27; C516724:PTPN11 protein, human; C509249:PTPN6 protein, human; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; D017027:Protein Tyrosine Phosphatases