Objective: To study the effects of Feiyanning Decoction, a compound traditional Chinese herbal medicine, on the ratio of CD4(+)CD25(+) regulatory T cells and expression of transcription factor Foxp3 in mice with Lewis lung cancer.
Methods: Thirty-two male wild-type C57BL/6 mice aging from 6 to 8 weeks were inoculated with Lewis lung cancer cells to establish the tumor-bearing model of Lewis lung carcinoma and were randomly divided into model group, Chinese medicine group, chemotherapy group and Chinese medicine combined with chemotherapy group. After intervention for 14 d with corresponding drugs, behaviors, physical signs and changes of feed consumption of the mice were observed. All mice were sacrificed after drug treatment, and tumors and organs were removed to weigh and calculate organ indexes (lung index, spleen index and thymus index). The percentages of CD4(+)CD25(+) regulatory T cells in the thymus, spleen and tumor were determined by flow cytometry. The expression of Foxp3 mRNA in the thymus, spleen and tumor tissues was detected by quantitative real-time polymerase chain reaction.
Results: Compared with those in the model group, the mice in the Chinese medicine group showed significant reductions in spleen and thymus indexes and tumor weight, and elevation in the body weight without tumor (P<0.05). The numbers of CD4(+)CD25(+) regulatory T cells in spleen, thymus and tumor were lower in the Chinese medicine group than in the model group (P<0.05). The expression of Foxp3 mRNA in spleen, thymus and tumor was significantly down-regulated in the Chinese medicine group compared with the model group (P<0.05). There were no significant differences in CD4(+)CD25(+) regulatory T cell ratio and Foxp3 mRNA expression between the Chinese medicine combined with chemotherapy group and the chemotherapy group.
Conclusion: Feiyanning Decoction can enhance the antitumor immune response and thus play a role in antitumor therapy by reducing the ratio of CD4(+)CD25(+) regulatory T cells and down-regulating the expression of Foxp3 mRNA.