Serum withdrawal-induced post-transcriptional stabilization of cyclooxygenase-2 mRNA in MDA-MB-231 mammary carcinoma cells requires the activity of the p38 stress-activated protein kinase.

TitleSerum withdrawal-induced post-transcriptional stabilization of cyclooxygenase-2 mRNA in MDA-MB-231 mammary carcinoma cells requires the activity of the p38 stress-activated protein kinase.
Publication TypeJournal Article
Year of Publication2000
AuthorsJang BC, Sanchez T, Schaefers HJ, Trifan OC, Liu CH, Creminon C, Huang CK, Hla T
JournalJ Biol Chem
Volume275
Issue50
Pagination39507-15
Date Published2000 Dec 15
ISSN0021-9258
KeywordsApoptosis, Blotting, Northern, Blotting, Western, Breast Neoplasms, Bromodeoxyuridine, Cell Cycle, Cell Nucleus, Culture Media, Serum-Free, Cyclooxygenase 2, Dactinomycin, Dinoprostone, Dose-Response Relationship, Drug, Enzyme Inhibitors, Gene Expression Regulation, Enzymologic, Genes, Dominant, Humans, Imidazoles, Isoenzymes, Membrane Proteins, Microscopy, Fluorescence, Mitogen-Activated Protein Kinases, Nucleic Acid Synthesis Inhibitors, p38 Mitogen-Activated Protein Kinases, Prostaglandin-Endoperoxide Synthases, Pyridines, RNA Processing, Post-Transcriptional, RNA, Messenger, Signal Transduction, Time Factors, Transfection, Tumor Cells, Cultured
Abstract

Overexpression of the cyclooxygenase-2 (COX-2) gene is observed in several neoplastic diseases. However, molecular mechanisms involved in the regulation of expression of COX-2 are not well understood. In this report, we describe a unique post-transcriptional regulatory mechanism of COX-2 mRNA stabilization in MDA-MB-231 cells, a highly metastatic cell line derived from a human mammary tumor. High levels of COX-2 mRNA, protein, and enzyme activity were induced by serum withdrawal, which were potently inhibited by the addition of serum or >100-kDa serum factor. Nuclear run-on analysis and actinomycin D chase experiments indicate that regulation is primarily at the level of post-transcriptional mRNA stability. Interestingly, SB203580, an inhibitor of the p38 stress-activated protein kinase (SAPK), and overexpression of the dominant-negative p38alpha construct potently inhibited the serum withdrawal-induced COX-2 mRNA levels. Indeed, the half-life of COX-2 mRNA decreased from 9 to 4.5 h after SB203580 treatment, suggesting that signal transduction by the p38 SAPK pathway is required for COX-2 mRNA stability.

DOI10.1074/jbc.M003224200
Alternate JournalJ Biol Chem
PubMed ID10993880
Grant ListHL49094 / HL / NHLBI NIH HHS / United States
HL54710 / HL / NHLBI NIH HHS / United States
Related Faculty: 
Teresa Sanchez, Ph.D.

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