Sorafenib inhibits interferon production by plasmacytoid dendritic cells in hepatocellular carcinoma

Background Sorafenib is a multi-kinase inhibitor that shows antitumor activity in advanced hepatocellular carcinoma. Sorafenib exerts a regulatory effect on immune cells, including T cells, natural killer cells and dendritic cells. Studies have shown that plasmacytoid dendritic cells (pDCs) are functionally impaired in cancer tissues or produce low type I interferon alpha (IFNα) in cancer microenvironments. However, the effects of sorafenib on the function of pDCs have not been evaluated in detail. Methods Normal and patient PBMCs were stimulated with CpG-A to evaluate IFNα production with Flow cytometry and ELISA. Result We analyzed the production of IFNα by PBMCs in patients with advanced HCC under sorafenib treatment. We found that sorafenib-treated HCC patients produced less IFNα than untreated patients. Furthermore, we demonstrated that sorafenib suppressed the production of IFNα by PBMCs or pDCs from heathy donors in a concentration-dependent manner. Conclusion Sorafenib suppressed pDCs function. Given that sorafenib is a currently recommended targeted therapeutic agent against cancer, our results suggest that its immunosuppressive effect on pDCs should be considered during treatment.