Cooperative regulation of Mcl-1 by Janus kinase/stat and phosphatidylinositol 3-kinase contribute to granulocyte-macrophage colony-stimulating factor-delayed apoptosis in human neutrophils.
Polymorphonuclear neutrophils (PMN) are phagocytic cells constitutively programmed for apoptotic cell death. Exposure to GM-CSF delays apoptosis as measured by annexin-V staining and cell morphological change. We found that STAT5B, STAT1, and STAT3 DNA-binding activity was induced by GM-CSF. We also detected activation of the phosphatidylinositol 3-kinase (PI 3-kinase) pathway after GM-CSF treatment which was inhibited by treatment with the PI 3-kinase inhibitors, wortmannin and LY294002. We investigated whether STAT or PI 3-kinase activity was necessary for the pro-survival response of GM-CSF in PMN. Exposure of PMN to GM-CSF in the presence of either AG-490, antisense STAT3 oligonucleotides, or wortmannin resulted in a partial inhibition of GM-CSF-mediated pro-survival activity. GM-CSF induced a time-dependent increase in the mRNA and protein expression of the anti-apoptotic Bcl-2-family protein, Mcl-1. We examined the hypothesis that Janus kinase/STAT and PI 3-kinase regulation of Mcl-1 contributed to GM-CSF-delayed apoptosis. Using either AG-490 or wortmannin alone, we observed a dose-dependent inhibition of GM-CSF-induced Mcl-1 expression. Using suboptimal doses of AG-490 and wortmannin, we found that both drugs together had an additive effect on delayed apoptosis and Mcl-1 expression. These data suggest that cooperative regulation of Mcl-1 by the Janus kinase/STAT and PI 3-kinase pathways contribute to GM-CSF-delayed apoptosis.
Epling-Burnette
P K
PK
Hematologic Malignancy Program, H. Lee Moffitt Cancer Center and Research Institute, University of South Florida College of Medicine, Tampa, FL 33612, USA. burnetpk@moffit.usf.edu
Zhong
B
B
Bai
F
F
Jiang
K
K
Bailey
R D
RD
Garcia
R
R
Jove
R
R
Djeu
J Y
JY
Loughran
T P
TP
Wei
S
S
D017209:Apoptosis / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology; D004357:Drug Synergism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000502:physiology*; D006801:Humans; D053613:Janus Kinase 1; D053614:Janus Kinase 2; D053616:Janus Kinase 3; D007700:Kinetics; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D009504:Neutrophils / Q000166:cytology* / Q000201:enzymology* / Q000378:metabolism; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D019869:Phosphatidylinositol 3-Kinases / Q000502:physiology*; D011233:Precipitin Tests; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000502:physiology*; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D050796:STAT3 Transcription Factor; D015398:Signal Transduction / Q000187:drug effects; D015534:Trans-Activators / Q000235:genetics / Q000502:physiology; D020032:Tyrphostins / Q000494:pharmacology; D051028:bcl-2-Associated X Protein
D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D009363:Neoplasm Proteins; D016376:Oligonucleotides, Antisense; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D015534:Trans-Activators; D020032:Tyrphostins; C095512:alpha-cyano-(3,4-dihydroxy)-N-benzylcinnamide; D051028:bcl-2-Associated X Protein; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D019869:Phosphatidylinositol 3-Kinases; D011505:Protein-Tyrosine Kinases; C507904:JAK1 protein, human; C507924:JAK2 protein, human; C507933:JAK3 protein, human; D053613:Janus Kinase 1; D053614:Janus Kinase 2; D053616:Janus Kinase 3