Histone deacetylase inhibitor pre-treatment enhances the efficacy of DNA-interacting chemotherapeutic drugs in gastric cancer

Figure 6 Valproic sensitizes AGS cell xenografts to cisplatin in an in vivo mice model. A: Schematic diagram depicting timeline of in vivo drug administration. AGS cells were injected into NOD-SCID mice. After tumors reached approximately 100 mm³; B: Mice were divided into four groups (n = 3), (1) control, (2) valproic acid (300 mg/kg/d), (3) cisplatin (2 mg/kg/d), and (4) combinatorial treatment of valproic acid followed by cisplatin at the same dose mentioned above; C: Average tumor volumes of groups normalized to the initial tumor volumes (before treatment) are plotted over a period of 5 wk of drug treatment. The outcome of the different treatment regimens was statistically validated by performing unpaired t-tests (^aP < 0.05; ^bP < 0.005); D: Mean weight of animals in a group measured over the treatment period to assess toxicity; E: Histopathology of tumor sections by hematoxylin and eosin staining of different groups following 5 wk of treatment. VPA: Valproic acid.