Figure 6. Inhibition of autophagy enhances the antitumor effect of Fhit protein.
in vivo. (A) Effects on tumor growth. H460 cells, stably expressing shRNA against beclin-1 (shBeclin-1) or LC3B (shLC3), were xenografted in nude mice. After tumors reached a volume of 100 mm3, a lentiviral vector expressing the Fhit gene (Fhit) or LacZ (LacZ) was injected into the tumors. Tumor volumes were measured daily. Results are reported as the mean ± standard deviation from six mice in each group. ***p < 0.001 for the control shRNA (shControl) + LacZ group versus the shControl + Fhit group and for the shControl + Fhit group versus the shBeclin-1 or shLC3 + Fhit group. (B) Tumors formed in nude mice. (C) Expression of apoptotic and autophagic proteins in tumors. Crude protein lysates were prepared from tumor samples on day 11 after injection and analyzed by Western blotting. (D–F) Effects of pharmacological inhibition of autophagy on the antitumor effect of Fhit protein. Hydroxychloroquine (HCQ, 60 mg/kg of body weight) or PBS was injected into the peritoneal cavity daily after intratumoral injection of lentiviral-Fhit (Fhit) or lentiviral-LacZ (LacZ). Results are shown as the mean ± standard deviation from five mice in each group. **p < 0.01 for the Fhit + PBS group versus Fhit + HCQ group.