Phorbol myristate acetate-induced Egr-1 expression is suppressed by phospholipase D isozymes in human glioma cells.
Early growth response-1 (Egr-1) is involved in the regulation of cell growth. Here, we found that overexpression of phospholipase D (PLD) isozymes decreased tumor promoter phorbol myristate acetate (PMA)-induced Egr-1 expression and transactivation in glioma cells. Suppression of PMA-induced Egr-1 was dependent on the expression level of PLD isozymes. Overexpression of catalytically inactive PLD, treatment with PA, and prevention of PA dephosphorylation by 1-propranolol significantly suppressed PMA-induced Egr-1 expression. PLD-induced suppression of Egr-1 was reversed by inhibition of phosphatidylinositol 3-kinase (PI3K). Taken together, these results suggest that elevated expression and activity of PLD attenuate PMA-induced Egr-1 expression via PI3K pathway.
Ahn
Bong-Hyun
BH
Cardiovascular Branch National Heart, Lung and Blood Institute, NIH Bldg 10/CRC 5-3288, 10 Center Drive, Bethesda, MD 20892, USA.
Park
Mi Hee
MH
Lee
Young Han
YH
Min
Do Sik
do S
D045744:Cell Line, Tumor; D051766:Early Growth Response Protein 1 / Q000235:genetics / Q000378:metabolism*; D017930:Genes, Reporter; D005910:Glioma / Q000201:enzymology* / Q000473:pathology*; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010739:Phospholipase D / Q000378:metabolism*; D020218:Response Elements; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D015533:Transcriptional Activation / Q000187:drug effects
C497325:EGR1 protein, human; D051766:Early Growth Response Protein 1; D007527:Isoenzymes; D019869:Phosphatidylinositol 3-Kinases; D010739:Phospholipase D; D013755:Tetradecanoylphorbol Acetate