Effects of glucocorticoids on antitumor effects of immunizations with fusions of dendritic and tumor cells.

Background: A pitfall of immunotherapy with dendritic cells (DCs) for patients with malignant tumor is that certain patients have already been treated with Dexamethasone (DEX) prior to vaccination. Therefore, it is important to investigate whether DEX has negative effects on induction of antitumor immune response in dendritic cell-therapy. Materials and Methods: We analyzed surface phenotypes and phagocytosis of DCs incubated with or without DEX. We also investigated the effects of DEX on in vivo antitumor effects of immunization with fusions of dendritic and glioma cells. Results: Treatment with DEX did not affect the expression of surface markers, including H-2K k , I-K k , CD80 and CD86, on DCs. Likewise, DEX did not affect phagocytosis. Immunization with FCs inhibited tumor growth in vivo, and DEX did not suppress antitumor effects induced by FCs. Conclusion: These data suggest that vaccination with FCs can be used to treat cancer patients receiving DEX.