title: SDF-1alpha promotes invasion of head and neck squamous cell carcinoma by activating NF-kappaB.
abstract: CXCL12/stromal cell-derived factor-1alpha (SDF-1alpha), a chemokine ligand for the G protein-coupled receptor CXCR4, plays an important role in the directed movement of cells. Many studies have documented the importance of CXCR4 in tumor progression and organ-specific metastasis. Recently, several studies have implicated a role for SDF-1alpha in head and neck squamous cell carcinoma (HNSCC) metastasis, but currently there is little information about how SDF-1alpha promotes HNSCC metastasis. In this report we show that the NF-kappaB signaling pathway is activated in response to SDF-1alpha in HNSCC while primary and immortalized keratinocytes show no SDF-1alpha-mediated NF-kappaB activity. We found that SDF-1alpha-mediated NF-kappaB signaling is independent of phosphoinositide 3-kinase/Akt and ERK/MAPK pathways. We observed that SDF-1alpha induces IkappaBalpha phosphorylation and degradation and the nuclear translocation of NF-kappaB in HNSCC cell lines, suggesting that SDF-1alpha activates the classical NF-kappaB signaling pathway. Contrary to previous reports, SDF-1alpha-induced NF-kappaB activation is not mediated by tumor necrosis factor alpha. Furthermore, blocking the NF-kappaB signaling pathway with an IKKbeta inhibitor significantly reduces SDF-1alpha-mediated HNSCC invasion. Taken together, our data suggest SDF-1alpha/CXCR4 may promote HNSCC invasion and metastasis by activating NF-kappaB and that targeting NF-kappaB may provide therapeutic opportunities in preventing HNSCC metastasis mediated by SDF-1alpha.
authors.affiliation: Laboratory of Molecular Signaling, Division of Oral Biology and Medicine, UCLA School of Dentistry, Los Angeles, CA 90095, USA.
authors.forename: Aasia O
authors.initials: AO
authors.lastname: Rehman
authors.forename: Cun-Yu
authors.initials: CY
authors.lastname: Wang
mesh_terms: D021581:Active Transport, Cell Nucleus; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology; D002460:Cell Line; D054377:Chemokine CXCL12 / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D051550:I-kappa B Kinase / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000187:drug effects; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism*; D009361:Neoplasm Invasiveness / Q000473:pathology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D019718:Receptors, CXCR4 / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D054377:Chemokine CXCL12; D016328:NF-kappa B; D019718:Receptors, CXCR4; D014409:Tumor Necrosis Factor-alpha; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D051550:I-kappa B Kinase; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3