Complex regulation of macrophage colony-stimulating factor in the HL-60 promyelocytic cell line.
The regulation of macrophage colony-stimulating factor (M-CSF) gene expression by phorbol esters and calcium ionophore (A23187) was studied in HL-60 cells. In untreated HL-60 cells, M-CSF transcripts were undetectable, but transcripts were present within 2 h of A23187 treatment or within 8 h of phorbol 12,13-dibutyrate (PdBu) treatment. Concurrent treatment of HL-60 cells with A23187 and cycloheximide (CHX) for 6 h led to a superinduction of message over A23187 treatment alone. But concurrent treatment with PdBu and CHX for 24 h abolished expression of the message normally present after 24 h of PdBu treatment. The role of new protein synthesis in transcriptional regulation of M-CSF was studied by run-on transcription assay. Untreated HL-60 cells or cells treated with CHX alone do not transcribe M-CSF mRNA. However, cells treated with A23187 for 6 h and CHX for 1, 3, or 6 h transcribed more M-CSF than cells treated with A23187 alone for 6 h. CHX also regulates M-CSF expression by message stabilization. The t1/2 of M-CSF mRNA was 45 min in cells treated with A23187 for 6 h or in cells treated with PdBu for 24 h, was over 2 h in HL-60 cells treated with A23187 for 6 h and CHX for 1 h, and was 3 h in cells treated with PdBu for 24 h and CHX for 1 h. We conclude that M-CSF gene expression can be differentially regulated in HL-60 cells and that new protein synthesis plays an important role in both the transcriptional and posttranscriptional regulation.
Sater
R A
RA
Department of Pharmacology, Duke University, Durham, NC 27710.
Cripe
L D
LD
Taylor
J D
JD
Niedel
J E
JE
D015152:Blotting, Northern; D000001:Calcimycin / Q000494:pharmacology; D003513:Cycloheximide / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D016173:Macrophage Colony-Stimulating Factor / Q000235:genetics*; D008264:Macrophages / Q000502:physiology*; D015240:Phorbol 12,13-Dibutyrate / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics; D014158:Transcription, Genetic / Q000187:drug effects; D014407:Tumor Cells, Cultured
D012333:RNA, Messenger; D015240:Phorbol 12,13-Dibutyrate; D000001:Calcimycin; D016173:Macrophage Colony-Stimulating Factor; D003513:Cycloheximide