RESUMO
BACKGROUND: B-cell activating factor (BAFF) belongs to the TNF superfamily of proteins, which influences the life span of normal and malignant cells. It has been demonstrated that there is an overexpression of BAFF in peripheral blood neutrophils and mononuclear cells in patients with oral squamous cell carcinoma (OSCC), suggesting a tumor-promoting activity of those cells. Taking into consideration that numerous OSCC cases are preceded by clinically evident oral potentially malignant disorders (OPMDs), involving e.g., oral lichen planus (OLP), we have examined the expression of BAFF molecule in the cells of patients with OLP, compared to the expression thereof in the cells of patients with OSCC. METHODS: Real-time PCR and western blot analysis confirmed significantly increased mRNA levels of BAFF in neutrophils of patients with OSCC and showed that it also increased in the cells of patients with OLP. Cells of patients with OSCC after treatment demonstrated a reduced expression of BAFF protein, but in the cells of patients with OLP after treatment we found increased expression of BAFF. RESULTS: LPS-stimulation led to reduced expression of BAFF protein in cells of all patients, before and after treatment and simultaneous increased expression of IκB, at mRNA and protein levels. CONCLUSIONS: Overexpression of BAFF demonstrated in neutrophils of both examined patient groups suggests that this molecule may be a factor linking oral lichen planus with oral squamous cell carcinoma, favoring the malignant transformation of OLP to OSCC. Furthermore, results obtained herein suggest that LPS may not only inhibit, but may even reduce BAFF expression in neutrophils of OLP patients.