Epidermal growth factor enhances transcription of human arachidonate 12-lipoxygenase in A431 cells.
Epidermal growth factor (EGF), determined by immunoprecipitation and Western blot analysis, increased both enzyme activity and protein level of 12-lipoxygenase in the solubilized microsomes of human epidermoid carcinoma A431 cells, respectively. The EGF-induced expression of 12-lipoxygenase mRNA was inhibited by transcription inhibitors such as actinomycin D and 5,6-dichlorobenzimidazole riboside. Promoters of different lengths for human 12-lipoxygenase gene were used to prepare the luciferase fusion vectors. These construct plasmids were transiently transfected into A431 cells, and the induction of luciferase expression by EGF was examined. A 4- to 6-fold increase in luciferase reporter activity stimulated by EGF for 18 h treatment was observed in plasmids with the 5'-flanking region length of -951 bp and that of -224 bp upstream from translation starting site. The time-dependent induction of luciferase activity by EGF paralleled the EGF-induced enzyme activity and expression of 12-lipoxygenase protein. Taken together, the results of this study indicate that EGF enhanced the transcription of the human 12-lipoxygenase gene, resulting in an increase in the amount and activity of 12-lipoxygenase.
Liu
Y W
YW
Department of Pharmacology, College of Medicine, National Cheng Kung University, Tainan, Taiwan, Republic of China.
Chen
B K
BK
Chen
C J
CJ
Arakawa
T
T
Yoshimoto
T
T
Yamamoto
S
S
Chang
W C
WC
D001092:Arachidonate 12-Lipoxygenase / Q000235:genetics / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000378:metabolism; D003600:Cytosol / Q000201:enzymology; D003609:Dactinomycin / Q000494:pharmacology; D004004:Dichlororibofuranosylbenzimidazole / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000235:genetics; D017930:Genes, Reporter / Q000235:genetics; D006801:Humans; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D008861:Microsomes / Q000201:enzymology; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects* / Q000235:genetics; D014162:Transfection / Q000235:genetics; D014407:Tumor Cells, Cultured; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
D019384:Nucleic Acid Synthesis Inhibitors; D012333:RNA, Messenger; D003609:Dactinomycin; D004004:Dichlororibofuranosylbenzimidazole; D004815:Epidermal Growth Factor; D001092:Arachidonate 12-Lipoxygenase; D008156:Luciferases; D001616:beta-Galactosidase