Zymosan promotes proliferation, Candida albicans adhesion and IL-1β production of oral squamous cell carcinoma in vitro

Oral squamous cell carcinoma (OSCC) is the most common type of head and neck squamous cell carcinoma (HNSCC), and the effect of zymosan (ZYM), a component of the yeast cell wall, on oral cancer remains unclear. The CCK-8 proliferation assay was performed to evaluate the effect of ZYM on the proliferation of the OSCC cell lines WSU-HN4, WSU-HN6 and CAL27, and the potential mechanism was explored by quantitative real-time PCR, immunofluorescence assay and western blot. A cell adhesion assay was conducted to determine the adhesion of Candida albicans to OSCC cells, and the expression of related genes, including TLR2, MyD88, NLRP3, ASC, Caspase-1 and IL-1β, and proteins, including TLR2, MyD88, NF-κB p65, p-NF-κB p65 and E-cadherin was determined. Additionally, the pro-inflammatory cytokines including IL-6, IL-8, TNF-α and IL-1β produced by OSCC cells were detected using a chemiluminescence immunoassay (CLIA). In the current study, the CCK-8 assay showed that ZYM promoted the proliferation of WSU-HN4, WSU-HN6 and CAL27 cells via the TLR2/MyD88 pathway. The cell adhesion assay showed that the number of C. albicans cells per field significantly increased in ZYM-treated OSCC cells compared to controls. When treated with ZYM, OSCC cells secreted significantly more pro-inflammatory cytokine IL-1β, which could enhance inflammation in oral cancer microenvironment. In conclusion, ZYM from the fungal cell wall promotes the proliferation, C. albicans adhesion and IL-1β production in OSCC, as demonstrated by in vitro experiments.