Induction of cyclooxygenase-2 by staurosporine through the activation of nuclear factor for IL-6 (NF-IL6) and activator protein 2 (AP2) in an osteoblast-like cell line.
The induction of cyclooxygenase-2 (COX-2) plays a crucial role in many physiological and pathological processes. The expression of the COX-2 gene is regulated by many extracellular stimuli, including growth factors, cytokines, and tumor promoters. Staurosporine, a potential anti-tumor drug, was found recently to up-regulate the expression of the COX-2 gene in the mouse osteoblast-like cell line MC3T3-E1. The ability of staurosporine to induce the expression of the COX-2 gene was investigated using luciferase reporters controlled by various COX-2 core promoter regions. Two cis-acting sites for activator protein 2 (AP2) and nuclear factor for IL-6 (NF-IL6), respectively, were identified as responsible for the staurosporine-mediated COX-2 up-regulation. Mutational analysis further verified that both NF-IL6 and AP2 are involved in this process. Further studies showed the stimulatory effect of staurosporine on luciferase activity to be both time- and concentration-dependent. Luciferase activity could be induced at as low as 5 nM staurosporine and reached a maximum at around 20 nM. At 50 nM, the stimulatory effect of staurosporine on luciferase activity reached a maximum at about 8 hr and fell rapidly following 10 hr of incubation. Interestingly, a selective protein kinase C inhibitor, 2-[1-(3-dimethylaminopropyl)indol-3-yl]-3-(indol-3-yl) maleimide (GF109203X), failed to stimulate luciferase activity under the same conditions. This finding implies that staurosporine-mediated COX-2 gene expression is specific and independent of protein kinase C activity.
Department of Biological Science and Technology, National Chiao Tung University, 75 Po-Ai Street, Hsinchu 30050, Taiwan, ROC.
Chiu-Ya
CY
Wang
Huey-Jing
HJ
Lei
Chi-Ying Fred
CY
Huang
Zhongjian
Z
Zhang
Anil B
AB
Mukherjee
Chiun-Jye
CJ
Yuan
D000818:Animals; D022782:CCAAT-Enhancer-Binding Protein-beta / Q000378:metabolism*; D002460:Cell Line; D051546:Cyclooxygenase 2; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004790:Enzyme Induction / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D017930:Genes, Reporter; D007211:Indoles / Q000494:pharmacology; D007527:Isoenzymes / Q000096:biosynthesis* / Q000235:genetics; D008156:Luciferases / Q000378:metabolism; D008301:Maleimides / Q000494:pharmacology; D051379:Mice; D009154:Mutation; D010006:Osteoblasts / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000187:drug effects* / Q000235:genetics; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis* / Q000235:genetics; D019311:Staurosporine / Q000494:pharmacology*; D013997:Time Factors; D050656:Transcription Factor AP-2; D014157:Transcription Factors / Q000378:metabolism*; D015854:Up-Regulation
D022782:CCAAT-Enhancer-Binding Protein-beta; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D007211:Indoles; D007527:Isoenzymes; D008301:Maleimides; D050656:Transcription Factor AP-2; D014157:Transcription Factors; D008156:Luciferases; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases; D019311:Staurosporine; C070515:bisindolylmaleimide I