Epidermal growth factor stimulates 3-hydroxy-3-methylglutaryl-coenzyme A reductase expression via the ErbB-2 pathway in human breast adenocarcinoma cells.
HMG-CoA reductase is the key enzyme for the biosynthesis of isoprenoid compounds essential for cell growth and differentiation. Its tyrosine kinase-dependent modulation has recently been suggested and described in the ErbB-2 overexpressing cell line SKBR-3 [Asslan et al. (1998) Biochem. J. 330, 241-246]. Epidermal growth factor (EGF) increased the HMG-CoA reductase activity, protein, and mRNA levels only in ErbB-2-expressing cells (SKBR-3 and MCF-7) but not in MDA-MB-468 cells that do not express ErbB-2 even though their EGF receptor was efficiently phosphorylated. Tyrphostin AG 879, a specific inhibitor of ErbB-2 tyrosine kinase activity, decreased HMG-CoA reductase activity only in cells that expressed ErbB-2. A functional EGF receptor appeared to be necessary since its inhibition by the specific tyrphostin AG 1478 abolished the EGF effects. Phosphatidylinositol 3-kinase (PI 3-kinase) might be a crucial enzyme in the signaling pathway since the specific inhibitor, LY 294002, was shown to inhibit HMG-CoA reductase activity and to completely abolish the stimulation by EGF in SKBR-3 cells.
Asslan
R
R
Laboratoire d'Oncologie Cellulaire et Moléculaire, UPRES-EA-2048, Faculté des Sciences Pharmaceutiques and Institut Claudius Regaud, 20-24 rue du Pont Saint Pierre, Toulouse Cedex, 31052, France.
Pradines
A
A
Pratx
C
C
Allal
C
C
Favre
G
G
Le Gaillard
F
F
D000230:Adenocarcinoma / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D001943:Breast Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D002867:Chromones / Q000494:pharmacology; D004815:Epidermal Growth Factor / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D066246:ErbB Receptors / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D005260:Female; D005419:Flavonoids / Q000494:pharmacology; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D006903:Hydroxymethylglutaryl CoA Reductases / Q000235:genetics / Q000378:metabolism*; D025782:Hydroxymethylglutaryl-CoA-Reductases, NADP-dependent; D009025:Morpholines / Q000494:pharmacology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010766:Phosphorylation / Q000187:drug effects; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D011799:Quinazolines; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D014407:Tumor Cells, Cultured; D020032:Tyrphostins / Q000494:pharmacology
D017871:Calcium-Calmodulin-Dependent Protein Kinases; D002867:Chromones; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D005419:Flavonoids; D006903:Hydroxymethylglutaryl CoA Reductases; D025782:Hydroxymethylglutaryl-CoA-Reductases, NADP-dependent; D009025:Morpholines; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011505:Protein-Tyrosine Kinases; D011799:Quinazolines; D018719:Erb-b2 Receptor Tyrosine Kinases; D020032:Tyrphostins; C081020:AG-879; C101044:RTKI cpd; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one