title: Fibronectin supports TNF-alpha-induced osteopontin expression through beta1 integrin and ERK in HN-22 cells.
abstract: The extracellular matrix (ECM), in collaboration with intracellular signal, plays a critical role in the modulation of cellular behavior and function. Herein, we investigated the influence of fibronectin (FN) and tumor necrosis factor-alpha (TNF-alpha) on OPN expression in HN-22, a human head and neck squamous cell carcinoma (HNSCC) cell line. The data showed that TNF-alpha significantly increased OPN expression only in the FN-coated condition. Application of function-blocking antibody directed against beta1 integrin abolished this OPN induction. Moreover, TNF-alpha when added together with activating beta1 integrin antibody is sufficient to induced OPN expression. The combination effect of FN and TNF-alpha was significantly deteriorated by a MEK inhibitor, but not NF-kappaB inhibitor. We further demonstrated that the phosphorylation of ERK1/2 was strongly enhanced by TNF-alpha and FN compared to the application of either one alone. Synergistic effect on ERK1/2 phosphorylation was also detected by TNF-alpha and activating beta1 integrin antibody, whereas inhibitory antibody to beta1 integrin attenuated FN and TNF-alpha-induced phosphorylation of ERK1/2. Our results indicate that FN coordinates TNF-alpha-mediated OPN induction via beta1 integrin-dependent signaling mechanism that activates ERK. The results suggest the critical role of tumor micro-environment signaling networks on the regulation of cytokine expression profiles during tumor progression.
authors.affiliation: Department of Anatomy, Faculty of Dentistry, Chulalongkorn University, Henri-Dunant Road, Pathumwan, Bangkok 10330, Thailand.
authors.forename: Ruchadaporn
authors.initials: R
authors.lastname: Kaomongkolgit
authors.forename: Jeeranan
authors.initials: J
authors.lastname: Manokawinchoke
authors.forename: Neeracha
authors.initials: N
authors.lastname: Sanchavanakit
authors.forename: Prasit
authors.initials: P
authors.lastname: Pavasant
authors.forename: Piyamas
authors.initials: P
authors.lastname: Sumrejkanchanakij
mesh_terms: D000704:Analysis of Variance; D015153:Blotting, Western; D002294:Carcinoma, Squamous Cell / Q000378:metabolism*; D005109:Extracellular Matrix / Q000378:metabolism; D005353:Fibronectins / Q000494:pharmacology*; D006258:Head and Neck Neoplasms / Q000378:metabolism; D006801:Humans; D019012:Integrin beta1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D053495:Osteopontin / Q000378:metabolism*; D010766:Phosphorylation; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D013194:Staining and Labeling; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D005353:Fibronectins; D019012:Integrin beta1; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D053495:Osteopontin; D048052:Mitogen-Activated Protein Kinase 3