Lipopolysaccharides increase the amount of CXCR4, and modulate the morphology and invasive activity of oral cancer cells in a CXCL12-dependent manner.

Recently, it has been reported that bacterial infections play an important role in the development of cancers of the upper aero digestive tract. To examine the influence of bacterial infections on oral cancer, human oral carcinoma T3M-1 cells were treated with lipopolysaccharide (LPS) for 24 h as a model of infection. The LPS treatment increased the mRNA expression of CXCR4 and invasiveness in T3M-1 cells stimulated with CXCL12. The Rho family of small guanosine triphosphatases regulates the dynamics of the actin cytoskeleton that underlie cellular functions such as cell shape changes, migration and polarity. In T3M-1 cells treated with LPS and stimulated with CXCL12, Rac and Cdc42 were activated and caused an increase in the development of filopodia. The present findings suggest that bacterial infections enhance the invasiveness of T3M-1 cells via CXCL12/CXCR4 interaction and Cdc42-activation. Furthermore, filopodia are critical to this process.