Alteration of intracellular actin levels induced by phorboldiester in human HL-60 leukemia cells susceptible or resistant to differentiation, and the effects of protein kinase inhibitors.
During monocyte-macrophage differentiation of HL-60 cells by 12-O-tetradecanoyl phorbol 13-acetate, the intracellular globular(G)-actin and polymerized(F)-actin increased 3-fold and 1.7-fold, respectively. Time course studies showed that these changes of actin levels were nearly coincident with the development of macrophage characteristics, including adhesiveness, positive reactivity against OKM-1 antibody and elevated lysozyme activity. When exposed to 5 nM TPA, these different properties of differentiation were detectable as early as 12 h after TPA treatment and reached a maximum by 24 h. Phosphorylation of 17 K and 27 K proteins, induced by TPA, occurred early (within 30 min) during TPA-induced differentiation. On the other hand, HL-60R cells, which are resistant to TPA in terms of the development of adhesiveness and differentiation, showed no change in both G- and F-actin levels, after the TPA treatment. TPA did not induce phosphorylation of these proteins in the HL-60R cells. In the presence of the protein kinase inhibitors, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H-7, 20 microM) and staurosporine (10 nM), the increase in actin levels induced by TPA was inhibited as well as other later evidence of differentiation. These results suggest that the phosphorylation of specific proteins is closely associated with the process of differentiation of HL-60 cells into macrophages.
Second Department of Internal Medicine, Mie University School of Medicine, Japan.
Y
Y
Uemura
M
M
Nishikawa
F
F
Komada
S
S
Shirakawa
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D000199:Actins / Q000378:metabolism*; D000470:Alkaloids / Q000494:pharmacology; D000911:Antibodies, Monoclonal; D000937:Antigen-Antibody Reactions; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D003593:Cytoplasm / Q000378:metabolism*; D004351:Drug Resistance; D006801:Humans; D007546:Isoquinolines / Q000494:pharmacology; D015473:Leukemia, Promyelocytic, Acute / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D008264:Macrophages / Q000473:pathology; D009363:Neoplasm Proteins / Q000378:metabolism; D010766:Phosphorylation; D010879:Piperazines / Q000494:pharmacology; D047428:Protein Kinase Inhibitors; D019311:Staurosporine; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014407:Tumor Cells, Cultured / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology
D000199:Actins; D000470:Alkaloids; D000911:Antibodies, Monoclonal; D007546:Isoquinolines; D009363:Neoplasm Proteins; D010879:Piperazines; D047428:Protein Kinase Inhibitors; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D019311:Staurosporine; D013755:Tetradecanoylphorbol Acetate