Figure 3.
Melatonin suppressed tumor growth and enhanced etoposide (VP16)-induced inhibitory effects on tumors in vivo. (A,B) A total of 5 × 106 Huh7 cells were injected subcutaneously into both the right and left flanks of nude mice (n = 6, each group). Representative images show the tumor xenografts after 4 weeks. (C) Tumor volumes were measured three times a week and calculated using the formula: length × width2 × 0.5. Bars indicate S.D. * p < 0.05, ** p < 0.01. (D) Body weights were recorded three times a week. (E) Histological analysis of xenografts using H&E staining and immunohistochemical staining for cleaved caspase-3 and cleaved caspase-9 showed that melatonin enhanced etoposide-induced apoptosis. Magnification: 400×, scale bar = 100 μm.