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Inhibition of epidermal growth factor‐induced invasion by dexamethasone and AP‐1 decoy in human squamous cell carcinoma cell lines
Author(s) -
Shiratsuchi Toru,
Ishibashi Hiroaki,
Shirasuna Kanemitsu
Publication year - 2002
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.10181
Subject(s) - urokinase receptor , matrigel , epidermal growth factor , plasmin , plasminogen activator , biology , cell culture , transfection , microbiology and biotechnology , growth factor , cancer research , chemistry , angiogenesis , receptor , endocrinology , biochemistry , genetics , enzyme
Invasive squamous cell carcinoma (SCC) cells degrade extracellular matrix (ECM) via an extracellular protease cascade that includes urokinase‐type plasminogen activator (uPA), plasmin, and the metalloprotease (MMP) family of collagenases. In this study, treatment of oral SCC cells with epidermal growth factor (EGF) stimulated the cells to invade Matrigel (constructive basement membrane (BM) protein). EGF‐induced cell invasion was inhibited by antibodies to uPA and by synthetic uPA inhibitors. EGF also induced increased expression of uPA and uPA receptor (uPAR) proteins and mRNA, as well as transcription factor activator protein‐1 (AP‐1)–DNA binding. These EGF‐induced changes were inhibited by treatment with dexamethasone (DEX). DEX treatment also stimulated the production of plasminogen activator inhibitor type 1. Moreover, transfection of SCC cells with AP‐1 decoy oligodeoxynucleotides (ODNs) resulted in the suppression of EGF‐induced uPA and uPAR expression and Matrigel invasion. These results suggest that oral SCC cells invade Matrigel mainly through the uPA‐plasmin cascade, which is mediated by the transcription factor AP‐1. The uPA–uPAR interaction is essential for augmenting proteolytic activity and uPAR‐mediated signaling, which ultimately induce motility and invasion. Since DEX inhibits the expression of both uPA and uPAR, it may be a useful treatment for oral SCC. J. Cell. Physiol. 193: 340–348, 2002. © 2002 Wiley‐Liss, Inc.