RT Journal Article SR Electronic T1 COX2 Inhibitor NS398 Reduces HT-29 Cell Invasiveness by Modulating Signaling Pathways Mediated by EGFR and HIF1-α JF Anticancer Research JO Anticancer Res FD International Institute of Anticancer Research SP 1793 OP 1800 VO 34 IS 4 A1 CLAUDIA BOCCA A1 FRANCESCA BOZZO A1 ANTONELLA MIGLIETTA YR 2014 UL http://ar.iiarjournals.org/content/34/4/1793.abstract AB Background: Signals from the tumor microenvironment (hypoxia, growth factors) are known to induce an invasive phenotype. Cyclooxygenase-2 (COX2) overexpression, involved in colorectal carcinoma (CRC) progression, is also associated with epidermal growth factor receptor (EGFR) up-regulation. The present study investigated whether inhibition of COX2 may affect, under normoxia and hypoxia, EGF-induced cell proliferation and invasiveness by using immunoblotting, trypan blue assay, Boyden chamber assay and zymography. Results: The proliferative and invasive activity of HT-29 cells was enhanced under hypoxia. COX2 expression was increased after epidermal growth factor (EGF) stimulation under both hypoxia and normoxia, expression that was efficiently reduced by the COX2 inhibitor NS398. Under normoxia, NS398 reduced signalling pathways induced by EGF [phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT), extracellular-signal-regulated kinases (ERKs)], while under hypoxia, EGF stimulation and NS398 treatment was associated with HIF-1α expression. Under both conditions, NS398 was able to inhibit cell invasiveness and matrix-metalloproteinase-2 release. Conclusion: COX2 inhibition can contribute to reducing cell aggressiveness through interfering with EGF- and hypoxia-mediated signaling.