Activation of serine/threonine protein kinases and early growth response 1 gene expression by tumor necrosis factor in human myeloid leukemia cells.
The early growth response 1 (EGR-1) gene is induced by mitogenic and differentiating signals in diverse cell types. The present studies have examined the effects of TNF-alpha on the induction of EGR-1 expression in human myeloid leukemia cells and the potential cytoplasmic signaling cascades that transduce TNF-induced signals to the nucleus. The results demonstrate that treatment of HL-60 cells with TNF is associated with the transient induction of the EGR-1 gene. The results also demonstrate that TNF treatment is associated with activation of the serine/threonine kinase, pp90rsk, which acts upstream to EGR-1 gene induction. Partial purification of pp90rsk by affinity chromatography demonstrated an increase in S6 peptide phosphorylation in response to TNF treatment. Because TNF activates sphingomyelin hydrolysis, we also studied the effects of sphingomyelinase (SMase) on induction of EGR-1 and pp90rsk. The results demonstrate that SMase also activates pp90rsk and induces EGR-1 gene expression. Previous work has demonstrated that mitogen-activated protein (MAP) kinase activates pp90rsk. The present studies further show that treatment with TNF or SMase is associated with induction of both the pp42/44 MAP and the related Jun kinases. Induction of pp42/44 MAP kinase activity is temporally related to activation of pp90rsk and the EGR-1 gene. These findings support the involvement of an MAP kinase/pp90rsk/EGR-1 cascade in the response of myeloid leukemia cells to TNF.
Saleem
A
A
Division of Cancer Pharmacology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA.
Yuan
Z M
ZM
Taneja
N
N
Rubin
E
E
Kufe
D W
DW
Kharbanda
S M
SM
D000595:Amino Acid Sequence; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics*; D051766:Early Growth Response Protein 1; D004789:Enzyme Activation / Q000187:drug effects; D015870:Gene Expression / Q000187:drug effects; D017781:Genes, Immediate-Early; D006801:Humans; D017874:Immediate-Early Proteins; D066298:In Vitro Techniques; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D019893:Ribosomal Protein S6 Kinases; D013108:Sphingomyelin Phosphodiesterase / Q000494:pharmacology; D014157:Transcription Factors / Q000235:genetics*; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D004268:DNA-Binding Proteins; C497325:EGR1 protein, human; D051766:Early Growth Response Protein 1; D017874:Immediate-Early Proteins; D010455:Peptides; D016755:Proto-Oncogene Proteins c-jun; D012333:RNA, Messenger; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; D017346:Protein Serine-Threonine Kinases; D019893:Ribosomal Protein S6 Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D013108:Sphingomyelin Phosphodiesterase