Activation of TLR2 and TLR5 did not affect tumor progression of an oral squamous cell carcinoma, YD-10B cells

Background: Toll-like receptors (TLRs) signaling has been found to promote cell proliferation, invasiveness, and angiogenesis in a variety of cancers. This study was performed to examine whether TLR signaling is involved in tumor progression of an oral squamous cell carcinoma, YD-10B cells. Methods: TLRs expression was examined by reverse transcription-polymerase chain reaction (RT-PCR) in YD-10B cells. Interleukin (IL)-6 and IL-8 production by YD-10B cells in response to various TLR agonists was examined by ELISA. Cell viability and proliferation was determined by colorimetric MTT and Bromodeoxyuridine (BrdU) assay. The effect of TLR agonists on invasiveness was determined by migration and invasion assay using commercial kits. mRNA expression of vascular endothelial growth factor (VEGF) was also evaluated by RT-PCR. Results: All tested TLRs including TLR2, 3, 4, 5, 7, and 9 were expressed in YD-10B cells. IL-6 and IL-8 production was increased by Pam(3)CSK(4), flagellin, Poly I:C, and imiquimod, but not lipopolysaccharide (LPS). Porphyromonas gingivalis LPS (Pg LPS) also led to increase of IL-8 production. However, Pam(3)CSK(4,) flagellin, and Pg LPS did not affect cell proliferation, migration, invasion, and gene expression of VEGF in YD-10B cells. Conclusion: These findings indicated that TLR activation by bacterial molecules may not affect tumor progression of YD-10B cells.