Epidermal growth factor induces expression of decay-accelerating factor in human colonic cancer cells via the mitogen-activated protein kinase pathway.
The expression of decay-accelerating factor (DAF), a complement regulatory protein, is enhanced in colorectal cancer. In this study, to elucidate mechanisms for enhanced DAF expression, we studied the effects of growth factors on DAF expression in HT-29 human colonic cancer cells. Cells were treated with epidermal growth factor (EGF), insulin-like growth factor-I, platelet-derived growth factor, and transforming growth factor-beta. DAF protein expression and mRNA expression were determined with enzyme immunoassay and Northern blot analysis. The signaling pathways that target DAF expression in response to growth factor stimulation were characterized by using various inhibitors of the signal transduction pathway. EGF induced significant increases in DAF protein and mRNA expression in HT-29 cells; the other growth factors had a weak effect or no effect. The EGF-induced DAF expression was inhibited by mitogen-activated protein (MAP) kinase kinase inhibitor PD 98059 but not by phosphatidylinositol-3 kinase inhibitor, phospholipase Cgamma inhibitor, or protein kinase C inhibitor. When we analyzed the phosphorylation state of the MAP kinase by immunoblot analysis, phosphorylated p44/p42 MAP kinase was detected in EGF-stimulated HT-29 cells, and the addition of PD 98059 abrogated the phosphorylation. These results indicate that EGF regulates DAF expression in HT-29 cells via the signaling pathway that depends on the activation of MAP kinase.
Takeuchi
K
K
First Department of Internal Medicine, Okayama University Medical School, Japan.
Mizuno
M
M
Uesu
T
T
Nasu
J
J
Kawada
M
M
Hori
S
S
Okada
H
H
Endo
Y
Y
Fujita
T
T
Tsuji
T
T
D015152:Blotting, Northern; D018958:CD55 Antigens / Q000096:biosynthesis* / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D005419:Flavonoids / Q000494:pharmacology; D019073:HT29 Cells / Q000187:drug effects / Q000201:enzymology*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D020929:Mitogen-Activated Protein Kinase Kinases / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction; D016212:Transforming Growth Factor beta / Q000494:pharmacology
D018958:CD55 Antigens; D004791:Enzyme Inhibitors; D005419:Flavonoids; D010982:Platelet-Derived Growth Factor; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D004815:Epidermal Growth Factor; D007334:Insulin-Like Growth Factor I; D020929:Mitogen-Activated Protein Kinase Kinases; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one