Proto-Oncogenes and Cell Cycle Gene Expression in Normal and Neoplastic Oral Epithelial Cells Stimulated With Soluble Factors From Single and Dual Biofilms of and .

This study was aimed at analyzing proto-oncogenic signaling pathway activation in normal oral keratinocytes (NOK-si) and neoplastic cell lines (SCC 25 and Detroit 562) stimulated with metabolites (soluble factors) from single and dual biofilms of and . Soluble factors (SF) from early (16-h) and mature (36-h) biofilms of and were collected and incubated with cell cultures, which were subsequently evaluated using gene expression via RT-qPCR, cell viability via AlamarBlue, and flow cytometry cell cycle analysis. In general, exposure to the SF of early and mature biofilms from and dual species caused a major reduction in NOK-si cell viability and enhanced the sub G0 phase. This led to a decrease in gene expression. However, in this cell line, SF of biofilms upregulated the gene followed by the maintenance of cell viability and a significant increase in the G2/M population. For tumor cells, SCC 25 and Detroit 562, the stimuli of SF biofilms upregulated oncogenes such as and , as well as and . SCC 25 and Detroit 562 cells could survive even after 24 h of stimuli from both SF (early and mature). This occurred without significant changes taking place in the cell cycle progression for SCC 25, and with a significant tendency to increase the G2/M phase for Detroit 562. These results point to the fact that metabolites from prevalent clinical fungal and bacterial biofilms, and , can disrupt the homeostasis of normal and neoplastic oral epithelial cells. This changes proto-oncogenes' expression, specifically , , , , and cell cycle genes and , thus causing a disturbance in cell viability, survival, and the cell cycle profile.