S-Space Graduate School of Convergence Science and Technology (융합과학기술대학원) Dept. of Molecular and Biopharmaceutical Sciences (분자의학 및 바이오제약학과) Journal Papers (저널논문_분자의학 및 바이오제약학과)
Roles of ERK and p38 mitogen-activated protein kinases in phorbol ester-induced NF-κB activation and COX-2 expression in human breast epithelial cells
- Kim, Jung-Hwan; Na, Hye-Kyung; Pak, Youngmi K.; Lee, Yun-Sil; Lee, Su-Jae; Moon, Aree; Surh, Young-Joon
- Issue Date
- Chemico-Biological Interactions, Vol.171 No.2, pp.133-141
- human breast epithelial cells; cyclooxygenase-2; NF-kappa B; mitogen-activated protein kinase; chemoprevention; phorbol ester
- Inappropriate up-regulation of cyclooxygenase-2 (COX-2) has been implicated in pathogenesis of various types of human cancer. Thus, COX-2 has been recognized as an important target for the chemoprevention of several human malignancies including breast cancer. COX-2 expression is known to be regulated by the eukaryotic transcription factor NF-kappa B. In an attempt to link the NF-kappa B activation and COX-2 induction during mammary carcinogenesis, we have examined the effects of 12-O-tetradecanoylphorbol-13-acetate (TPA), a prototype tumor promoter and a mitogen, on NF-kappa B activation and COX-2 expression in the immortalized human breast epithelial cell line (MCF10A). Treatment of MCF10A cells with TPA resulted in transient induction of NF-kappa B DNA binding with maximal activation observed at 30 min. Increased DNA binding of NF-kappa B was accompanied by enhancement of its transcriptional activity as determined by the luciferase reporter gene assay. Under the same experimental conditions, expression of COX-2 mRNA and its protein product peaked at 2 h and 4 h, respectively. TPA treatment caused an increase in the production of prostaglandin E-2. Treatment of cells with the NF-kappa B inhibitor pyrrolidine dithiocarbamate resulted in significant suppression of TPA-induced COX-2 expression. TPA induced activation of ERK1/2 and p38 mitogen-activated protein kinases (MAPK) via phosphorylation. PD98059 (ERK inhibitor) and SB203580 (p38 MAPK inhibitor) down-regulated the COX-2 expression induced by TPA. Furthermore, TPA-induced COX-2 induction as well as NF-kappa B activation was blocked in MCF10A cells transfected with dominant negative mutant ERK1/2 or p38 MAPK. These results suggest that both p38 and ERK MAPKs activates NF-kappa B signaling, which in turn induces COX-2 expression in TPA-stimulated human mammary epithelial cells. (c) 2007 Elsevier Ireland Ltd. All rights reserved.
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