Effects of secretome from areca nut-exposed fibroblast cells on malignant transformation of oral epithelial cells

The intercellular signaling between fibroblast cells and epithelial keratinocytes in oral cavity plays an important role in the malignant transformation of oral submucous fibrosis (OSMF) to oral squamous cell carcinoma (OSCC). Hence, the current study was designed to evaluate the effect of the secretome from the areca nut-exposed fibroblast cells on the oral keratinocytes. We collected the conditioned media (CM) from the fibroblast cells exposed with the areca nut extract (10 µg/ml) for 48 hrs and transferred it to the keratinocyte cells, followed by incubation for 48 hrs. We then assessed the cell proliferation, mRNA expression for OSCC-related genes, and metabolomics of the CM and cell lysate by liquid chromatography-mass spectrometry (LCMS). We found a higher proliferation in the cells incubated with exposed CM compared to unexposed CM. The mRNA expression profiles show significant upregulation of five genes ( pcsk9, mmp12, inhba, mmp11, and hoxd11 ). The metabolomics shows alteration of tryptophan metabolism, pyrimidine metabolism, aspartate & asparagine metabolism in CM, and glycolysis and gluconeogenesis in the cell lysate. In conclusion, we identified the genes and pathways that are affected by the secretome from areca nut exposed fibroblast cells and may have a role in the malignant transformation of oral submucous fibrosis.