The activation of PI 3-K and PKC zeta in PMA-induced differentiation of HL-60 cells.
The human myelocytic leukemia cell line HL-60 is a useful model for the study of cellular differentiation. Phorbol 12-myristate 13-acetate (PMA) induces the monocyte/macrophage-like differentiation of HL-60 cells and results in growth arrest, increasing adherence. In PMA-induced differentiation of HL-60 cells, phosphoinositide 3-kinase (PI 3-K) activity was measured as phosphatidylinositol3P recovery from phosphatidylinositol by in vitro kinase assay. PI 3-K activity was increased in HL-60 cells that were stimulated by 20 nM PMA and the activity was inhibited by pretreatment with 20 microM LY294002, a specific inhibitor of PI 3-K. Members of the protein kinase C (PKC) family have been suggested to be one of the downstream targets of PI 3-K. PKC zeta is one of the atypical PKCs, non-diacylglycerol-responsive PKCs, and the activity was measured by the ability of phosphorylation onto myelin basic protein. PMA also induced the activation of PKC zeta during monocytic differentiation of HL-60 cells, and LY294002-pretreated cells failed to induce PKC zeta activation. The activity of PI 3-K is essential for PKC zeta activation, and LY294002 blocks both monocytic differentiation of HL-60 cells and activation of PKC zeta during PMA-induced cell differentiation. This implies that activated PI 3-K subsequently stimulates the PKC zeta in the process of PMA-induced monocytic differentiation.
Kim
M S
MS
College of Pharmacy and Center of Oriental Medicinal Science, Wonkwang University, Iksan, 570-749, Chonbuk, South Korea.
Lim
W K
WK
Cha
J G
JG
An
N H
NH
Yoo
S J
SJ
Park
J H
JH
Kim
H M
HM
Lee
Y M
YM
D002454:Cell Differentiation / Q000187:drug effects; D002867:Chromones / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018922:HL-60 Cells / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D006801:Humans; D009025:Morpholines / Q000494:pharmacology; D009363:Neoplasm Proteins / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D000099221:Protein Kinase C zeta
D002867:Chromones; D004791:Enzyme Inhibitors; D009025:Morpholines; D009363:Neoplasm Proteins; D019869:Phosphatidylinositol 3-Kinases; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate; D000099221:Protein Kinase C zeta; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one