Effect of LPS on the Viability and Proliferation of Human Oral and Esophageal Cancer Cell Lines

The esophagus and mouth tumors are very frequent malignancies worldwide. Lipopolysaccharides (LPS) are capable of regulating gene expression of pro-inflammatory cytokines by binding to toll-like receptor 4 (TLR4). Recent studies show that LPS can increase the migration ability of human esophageal cancer cell line HKESC-2 by increasing its adhesion properties. However, the effect of LPS has not been tested on viability of human esophageal and oral cancer cells. This study aimed to determine the action of LPS on the cell proliferation and viability in OE19 (adenocarcinoma) and OE21 (squamous carcinoma) cell lines, representative of human esophageal cancer, and HN30 cell line, representative of human oral carcinoma. LPS was used as treatment to OE19 and OE21 cells, and PgLPS (Porphyromonasgingivalis lipopolysaccharide) to HN30 cells. Viability was assessed by MTT assay and proliferation by cell counting. TLR4 expression was evaluated by real-time PCR. LPS at higher concentrations decreased significantly cell viability in both cell lines, adenocarcinoma (OE19) and squamous esophageal carcinoma (OE21) at different times of treatment. In addition, both cell lines, OE19 and OE21, expressed TLR4 receptor. Taken together, our data demonstrated that LPS at high concentrations might contribute to tumor death, in agreement with previously data.