Introduction: The purpose of this study is to investigate the effect of lipopolysaccharide from periodontal pathogen Porphyromonas gingivais on proliferation, invasion and apoptosis of head and neck cancer cells.Methods: Human monocytic cells (THP-1) were activated by P. gingivalis lipopolysaccharides (250-1,000 ng/ml) for 24 hours, then the conditioning media of the activated THP-1 were collected, and co-cultured with head and neck cancer cell lines (primary cancer cell line: HN18 and metastatic cancer cell line: HN17). Cell proliferation, invasion and apoptosis were analyzed by MTT assay,modified Boyden chamber assay and flow cytometry Annexin V- FITC assay, respectively.Results: The head and neck cancer cell lines when co-cultured with conditioning media of P. gingivalis LPS activated THP-1 cells showed the significant increase of cell proliferation and invasion indose dependent manner. In addition, the conditioning media could inhibit apoptosis in both primary and metastatic cell lines.Conclusion: These results suggested that activated monocytes by P. gingivalis LPS can enhance aggressiveness in both primary and metastatic head and neck cancer cell lines
Toneluck et al. (Thu,) studied this question.