Serum IL-17F combined with VEGF as potential diagnostic biomarkers for oral squamous cell carcinoma

Although interleukin (IL) 17A can promote angiogenesis in several tumors, there are limited clinical evidences on cancer about the correlation between serum vascular endothelial growth factor (VEGF) and IL-17F, which is the most homologous to IL-17A. In this study, serum concentration of IL-17F and VEGF from healthy (n = 28), leukoplakia (n = 15), and oral squamous cell carcinoma (OSCC) groups (n = 85) were assessed and showed that IL-17F level was remarkably downregulated from healthy group (394.3 pg/ml) to OSCC group (82.96 pg/ml). Conversely, the OSCC group had a highest level of VEGF (P < 0.05) in whole groups, and there was a negative correlation between IL-17F and VEGF in serum or in the peripheral blood mononuclear cells (PBMCs) at mRNA level. Moreover, the lowest ratio of IL-17F/VEGF was found in OSCC patients (P < 0.05) and lower ratio of IL-17F/VEGF correlated to higher tumor stage and lymph node metastasis. Furthermore, the serum level of IL-17F and the ratio of IL-17F/VEGF were positively associated with the numbers of CD3⁺ CD4⁺ T cells, which indicated that serum IL-17F could originate from PBMCs during the development of OSCC, and could be used for the diagnosis by effectively distinguishing OSCC patients from healthy individuals.