Microwave ablation combined with dendritic cell vaccine: a potential synergistic therapy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignant cancers with a high recurrence rate. An effective therapeutic strategy for HCC is, therefore, in urgent demand. This work aims to investigate the in vivo anti-HCC effect of microwave ablation (MWA) followed by tumor lysate activated dendritic cell (DC) vaccine. C57BL/J mice were rechallenged with Hepa1-6 tumor cells with different treatments (single MWA, single DC injection and MWA combined with DC injection). Then tumor growth was monitored and compared. The populations of Treg and Th17 cells were detected by flow cytometry and immunohistochemistry before and after different treatments. The migration of DCs was monitored using optimal imaging. A general volume decrease in the rechallenged tumors was observed both in the MWA and MWA + DC groups. The volume of the rechallenged tumors in the MWA + DC group showed a more significant downward trend compared with that in the MWA group. The migration of DCs from the injected site to the inguinal lymph node region was detected 24 h after injection by optimal imaging. A significant decrease of Treg and Th17 cells in the peripheral blood and lymph nodes was observed in the mice of the MWA + DC group. In summary, MWA combined with DC vaccination showed an effective synergistic therapy for HCC, with few tumor recurrences.