Inhibition of mouse B16 melanoma by Sodium butyrate correlated to tumor associated macrophages differentiation suppression

Objective: As one member of the histone deacetylase inhibitor (HDACi) family, Sodium butyrate (NaB) was found out that could be used as a differentiation inducer of much cancer cell. But its effects on tumor microenvironment cells are not well recognized. The goal of this research is to investigate the effect of NaB on B16 melanoma and analysis its relevant mechanism. Methods: We observed the effect of sodium butyrate on B16 melanoma in vivo and in vitro. MTT method was performed to detect cell apoptosis rate after treatment. Tumor associated macrophage infiltration condition was detected by flow cytometry. Western-blotting and immunohistochemical method were used to detect the expression of tumor associated macrophage cytokines. Results: A certain concentration of sodium butyrate could effectively inhibit B16 melanoma growth in vivo and in vitro. Compared with the control group (45.00 ± 3.43%), macrophage differentiation in the 1.0g / kg group (37.54 ± 2.34%), 2.0g / kg group (41.62 ± 3.10%) and 3.0g / kg group (29.28 ± 4.42%) group were all inhibited to varying degrees. The inhibitory effect was most significant in the 5.0 g / kg group (19.92 ± 4.80%), and the difference was statistically significant (P <0.01).At the same time we observed the relevant macrophage factors were down-regulated compared to the control. Conclusion: Sodium butyrate could effectively inhibit B16 melanoma growth through suppressing tumor associated macrophage proliferation and reduce relevant pro-tumor macrophage factors expression, which may help to promote the clinical study of melanoma epigenetic therapy.

Study on biological behavior and mechanism of icariin on mouse melanoma B16 cells by regulating PI3K/AKT/mTOR pathway

Objective:To study the effect and mechanism of icariin on the migration,proliferation and apoptosis of mouse melanoma B16 cells.Methods:Mouse melanoma B16 cells were treated with icariin at different concentrations(0,10,20,50μmol/L)for 24 hours.Cell proliferation,morphology,apoptosis and migration ability were detected,and the expression of PI3K/AKT/mTOR pathway related proteins was detected by Western blot assay.Results:After treatment with icariin,the inhibition rate and apoptosis rate of mouse melanoma B16 cells increased significantly with the increase of administration concentration(P<0.05).Hoechst 33258 staining showed that the cells in the blank control group(0μmol/L)were uniformly stained and the color was lighter,while the cells in the experimental group containing icariin were thicker in color.The higher the concentration of the icariin,the more obvious the degree of chromatin aggregation.The scratch healing rate of B16 cells and the cell count on the bottom of Transwell membrane decreased significantly with the increase of icariin concentration(P<0.05).The results of protein detection showed that with the increase of administration concentration,the expression of MMP-9,MMP-2 and mTOR decreased significantly,while the ratio of PI3K/pPI3K and AKT/pAKT increased significantly,and there was significant difference between the groups(P<0.05).Conclusions:Icariin can effectively inhibit the expression of PI3K/AKT/mTOR pathway related proteins in mouse melanoma B16 cells,thus inducing apoptosis of tumor cells,inhibiting cell migration and finally exerting antitumor effect.