Toll-like receptor 5 activation promotes migration and invasion of salivary gland adenocarcinoma.

J Oral Pathol Med (2011) 40: 187–193 Background:  Toll-like receptor (TLR) signaling has been found to be closely associated with tumor development. The aim of this study was to examine whether activation of TLRs promote migration and invasion of salivary gland adenocarcinoma. Materials and Methods:  TLR expression in SGT and HSG cells was examined by RT-PCR. Wound scratch and chemotaxis cell migration assay were performed. Invasiveness was determined by Matrigel invasion assay. Results:  All the tested TLRs including TLR1, TLR2, TLR4, and TLR5 and myeloid differentiation factor-2 (MD-2) were expressed on SGT and HSG cells. Treatment of flagellin, but not Pam3CSK4 and LPS, led to the production of IL-6 and IL-8, suggesting TLR5 is functional in both cells. Stimulation by flagellin also accelerated wound closure of SGT and HSG cells in a dose-dependent manner. In addition, flagellin promoted migration and invasion ability of SGT cells. Blocking of TLR5 using antibody restored the promoting effect of flagellin on migration and invasion of SGT cells. Conclusion:  These findings suggest that TLR5 activation by flagellin can promote migration and invasion of salivary gland adenocarcinoma.