Ação de lipopolissacarídeos na viabilidade e proliferação de linhagens celulares humanas de câncer de boca e esôfago

Abstract

The esophageal and oral tumors are classified as the most frequent malignancies in Brazil. Esophageal cancer is the eighth most common in the world and oral cancer is ranked as the 5th among malignant neoplasms affecting man in Brazil. The lipopolysaccharide (LPS) are characteristic compounds of the cell wall of gram-negative bacteria. They are able to regulate gene expression of pro-inflammatory cytokines by binding to toll-like receptor 4 (TLR4) via NF-kB pathway. Recent studies show that LPS can increase the migration ability of cell lines of human esophageal cancer HKESC-2 by increasing its binding properties. In the meantime, it has not been tested the effect of LPS on esophageal cancer cells OE19 and OE21 and human oral carcinoma HN30. Thus, this study aimed to determine the action of LPS compounds on the proliferation and viability of cell lines of human esophageal cancer and human oral carcinoma HN30. Were used as treatment LPS for OE19 and OE21 cell lines and the PgLPS (lipopolysaccharide of Porphyromonas gingivalis) for HN30 cell line. Cell viability was assessed using the MTT assay and cell counting. The TLR4 expression by real-time PCR was also evaluated. 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.