Lipopolysaccharide enhances OSCC migration by promoting epithelial-mesenchymal transition.

<bold>Background: </bold>This study was performed to examine whether lipopolysaccharide can influence cell migration and epithelial-mesenchymal transition of oral squamous cell carcinoma.<bold>Methods: </bold>Three oral squamous cell carcinoma cell lines (HSC3, CAL27, and SCC4) were obtained for the study. TLR4 expression in three cell lines was analyzed by Q-PCR and Western blot. After cells treated with LPS, cell migration was analyzed by wound-healing and chemotaxis cell migration assay. Changes of E-cadherin and vimentin expression were tested by Western blot and immunofluorescence staining. To examine NF-κB activation, NF-κB nuclear translocation was investigated.<bold>Results: </bold>TLR4 was expressed in all three cell lines and was highest in HSC3 while lowest in SCC4. TLR4 ligand lipopolysaccharide accelerated wound healing and enhanced cell migration. Also, it stimulated epithelial-mesenchymal transition demonstrated by decreased E-cadherin and increased vimentin expression. Lipopolysaccharide also provoked NF-κB nuclear translocation. Either TLR4 or NF-κB blocking reverted these effects.<bold>Conclusions: </bold>Lipopolysaccharide can induce TLR4-mediated epithelial-mesenchymal transition and cell migration in oral squamous cell carcinoma. These responses could further affect tumor progressing by inducing tumor cell metastasis. [ABSTRACT FROM AUTHOR]