The effect of microwave ablation combined with dendritic cell tumor vaccine treatment on mouse mammary carcinoma and its immunological mechanism

Abstract

Objective To investigate the therapeutic effects of microwave ablation combined with dendritic cell (DC) tumor vaccine on a murine breast cancer model and to explore its immunological mechanism.Methods Forty-eight Balb/c mice were used to establish models of mouse mammary carcinoma,and then randomly divided into a sham-operation group,a microwave ablation treated group,a DC tumor vaccinated group and a microwave ablation plus DC tumor vaccinated group.Microwave ablation was conducted with the microwave ablation group on day 14 after establishing the model.DC tumor vaccination was performed on day 7 in the vaccinated group.In the microwave ablation plus DC tumor vaccinated group,DC tumor vaccination and microwave ablation were consecutively performed on days 7 and 14,respectively.Tumor growth,lung metastasis and survival were observed.The proportion of CD3+ and CD4+ T cells in splenocytes were analyzed by fluorescence Activated Cell Sorter (FACS) on the 14th day after microwave ablation.Serum levels of interferon-γ (IFN-γ) and interleukin-4 (IL-4) were also detected using ELISA.Results The survival time (56.4 ± 4.3 days),tumor size (67.3 ± 6.1 mm2) and lung metastasis index (0.6 ± 0.4) in the microwave ablation plus DC tumor vaccinated group were all significantly lower than the corresponding averages in the microwave ablation and DC tumor vaccinated group.The proportions of splenic CD3 + T cells (27.8 ±10.3 ％) and CD4+ T cells (16.7 ± 8.3 ％) in the microwave ablation plus DC tumor vaccinated group were significantly larger than in the control group.Average serum levels of IFN-γ (41.8 ± 22.9 pg/ml) in the microwave ablation plus DC tumor vaccinated group were also significantly larger than in the control group,while the average serum level of IL-4 (15.4± 6.4 pg/ml) was significantly lower.Conclusions Microwave ablation and DC tumor vaccination together could have synergistic effects in treating experimental breast cancer,which might be closely related to the enhanced immune response. Key words: Breast cancer; Microwave ablation; Dendritic tumor vaccine; Tumor metastasis