Secretion of tumor-promoting and immune suppressive cytokines by cell lines of head and neck squamous cell carcinoma

Background: Cytokine profiles of permanent cell lines of head and neck squamous cell carcinoma (HNSCC) were analyzed to define the cytokine levels secreted in the absence of immune cells. Materials and Methods: Cytokine profiles of IL-4, IL-6, IL-8 and IL-10 were analyzed in the supernatants of 4 different permanent HNSCC cell lines using the Bio-Plex human cytokine assay system. Results: In HNSCC, IL-6 and IL-8 are involved in oncogenic processes, while IL-4 and IL-10 suppress proper immune responses in the tumor microenvironment. Our data indicate that, in the absence of tumor-infiltrating immune cells, HNSCC secretes high levels of the proto-oncogenic cytokines IL-6 and IL-8, but no significant levels of the immune suppressors IL-4 and IL-10. Conclusion: The data strongly suggest that the intercellular crosstalk between cells of HNSCC and tumor-infiltrating immune cells in vivo is required to stimulate an increased production of immune suppressive mediators in head and neck cancer.