Activation of tissue-factor gene expression in breast carcinoma cells by stimulation of the RAF-ERK signaling pathway

• Published in: Molecular carcinogenesis 1998-04, Vol.21 (4), p.234-243
• Main Authors: Zhou, Jian-Nian, Ljungdahl, Sofia, Shoshan, Maria C., Swedenborg, Jesper, Linder, Stig
• Format: Article
• Language: English
• Subjects: Base Sequence; Benzoquinones; breast cancer; Breast Neoplasms - genetics; Breast Neoplasms - pathology; Calcium-Calmodulin-Dependent Protein Kinases - physiology; Dactinomycin - pharmacology; DNA, Complementary - genetics; Enzyme Activation; Enzyme Induction - drug effects; Enzyme Inhibitors - pharmacology; Female; Flavonoids - pharmacology; Gene Expression Regulation, Neoplastic - drug effects; Genistein - pharmacology; Humans; Hydroquinones - pharmacology; Lactams, Macrocyclic; metastasis; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinases; Molecular Sequence Data; Neoplasm Invasiveness; Neoplasm Metastasis; Neoplasm Proteins - biosynthesis; Neoplasm Proteins - genetics; Neovascularization, Pathologic - genetics; NF-kappa B - physiology; Okadaic Acid - pharmacology; Phenols - pharmacology; Proto-Oncogene Proteins c-raf - physiology; Quinones - pharmacology; Rifabutin - analogs & derivatives; signal transduction; Signal Transduction - drug effects; Tetradecanoylphorbol Acetate - pharmacology; Thromboplastin - biosynthesis; Thromboplastin - genetics; tissue factor; Transcription Factor AP-1 - physiology; Transcription, Genetic; Tretinoin - pharmacology; Tumor Cells, Cultured - drug effects
• ISSN: 0899-1987; 1098-2744
• DOI: 10.1002/(SICI)1098-2744(199804)21:4<234::AID-MC2>3.0.CO;2-K

Tissue factor (TF) is a cell‐surface glycoprotein responsible for initiating the extrinsic pathway of coagulation. The overexpression of TF in human malignancy has been correlated with the angiogenic phenotype, poor prognosis, and thromboembolic complications. The mechanisms underlying constitutive expression of TF in cancer cells are poorly defined. We cloned TF cDNA on the basis of its strong expression in metastatic MDA‐MB‐231 breast carcinoma cells in contrast to its weak expression in non‐metastatic MCF‐7 cells. Transient transfection analysis showed that TF promoter activity in MCF‐7 cells could be stimulated by expression of a membrane‐targeted raf kinase (raf‐CAAX). Raf‐induced activity was dependent on the presence of an AP‐1/NF‐κB motif in the TF promoter and was inhibited by dominant‐negative mutants of jun and by I‐κBα. MDA‐MB‐231 cells were found to contain higher levels of ERK1/2 kinase activity than did MCF‐7 cells. Electrophoretic mobility shift assays showed that MDA‐MB‐231 nuclear proteins bound strongly to an oligonucleotide corresponding to the AP‐1/NF‐κB sequence, whereas MCF‐7 nuclear extracts showed weak binding to this element. Finally, we showed that TF mRNA levels in MDA‐MB‐231 cells declined after addition of the mitogen‐activated protein kinase kinase inhibitor PD98059. Our data showed that activation of the raf‐ERK pathway led to activation of TF expression in breast carcinoma cells and suggested that constitutive activation of this pathway leads to high TF expression in MDA‐MB‐231 cells. Mol. Carcinog. 21:234–243, 1998. © 1998 Wiley‐Liss, Inc.