IL-1α induces cathepsin K in oral cancer cells − the invasion is unaffected

BackgroundTo study cathepsin K location in oral tongue squamous cell carcinoma (OTSCC), its traffic and expression levels in cultured oral cell lines; and to analyze the effect of interleukin (IL)-1 on OTSCC invasion.\n\nMethodsCathepsin K expression in OTSCC tissue samples was analyzed with immunostaining; its intracellular traffic was followed in HSC-3 cells after PMA treatment. HSC-3 and two oral keratinocyte cell lines, oral carcinoma associated fibroblasts (CAFs) and primary gingival fibroblasts (GF) were treated with IL-1. Cathepsin K expression was measured using PCR and ELISA. Lastly, the effects of IL-1 on HSC-3 invasiveness, alone and in co-cultures with fibroblasts in the 3D myoma invasion model, were determined.\n\nResultsCathepsin K in OTSCC cells was found in vesicles close to cell membrane and within exosomes. While cathepsin K was expressed at the basal level in both epithelial cells and fibroblasts, basal IL-1 levels were higher in epithelial cells compared with GFs and CAFs. Cathepsin K expression was slightly induced by IL-1 in all cell lines, but it did not affect HSC-3 invasiveness.\n\nConclusionIn OTSCC, cathepsin K remains mostly intracellular and it is slightly secreted within exosomes. IL-1 treatment has no effect on HSC-3 invasiveness in 3D myoma model.