Figure 1.
Effect of VPA on tumor volume in Caki-1 xenografts in mice.
Mice in the treatment arm received 200 mg VPA/kg once daily. Control mice received solvent (n = 6). *indicates significant difference to the control mice.
Figure 2.
Western Blot analysis of cell cycle regulating (fig. 2A) and cell signaling proteins (fig. 2B) in tumor tissue from drug-sensitive (responders) versus drug-resistant mice (non-responders).
Control tissue specimens were taken from untreated animals. Cell lysates (50 µg) were subjected to SDS-PAGE and blotted on the membrane incubated with the corresponding monoclonal antibodies. β-actin served as the internal control. The figure shows one representative from three separate experiments.
Figure 3.
VPA acts on Caki-1 growth, independent of the initial Akt expression level.
Akthigh and Aktlow expressing Caki-1 cells, which were generated by a function blocking anti-Akt monoclonal antibody, were treated with 1 mM VPA (controls remained untreated) and subjected to the MTT cell growth assay (figure 3A). One representative from 6 experiments. *indicates significant difference to controls.
Figure 4.
Long-term exposure of VPA causes drug resistance and Akt up-regulation.
Fig. 4A: Caki-1 cells were treated for 2 weeks (short-term) or 12 weeks (long-term) with 1 mM VPA, and cell growth was analysed by the MTT assay. Controls remained untreated. The figure shows one representative from six separate experiments. *indicates significant difference to controls. Fig. 4B: To evaluate Akt expression and activity, Caki-1 cells were treated short-term or long-term with 1 mM VPA. Controls remained untreated. Cell lysates were subjected to SDS-PAGE and blotted on the membrane incubated with the respective monoclonal antibodies. β-actin served as the internal control. One representative from three separate experiments.