Figure 8.

Absence of BAD desensitizes CSCs from drug-induced apoptosis. (a) Spheres were produced from parental cells infected with lentiviral vectors containing BAD-shRNA or scrambled-shRNA. Sphere cell lysates were collected after 8 days, and immunoblotted with antibodies against BAD. Equal loading was judged by β-actin. Note that BAD expression was substantially suppressed by BAD-shRNA. (b) Tumorospheres expressing BAD-shRNA or Scr-shRNA were incubated for 24 h with indicated inhibitors and VIP in supplement-free DMEM medium. Phase-contrast images of spheres are shown. Scale bar=100 μm. (c) Purified CSCs expressing either BAD-shRNA or Scr-shRNA were treated as in b, and the caspase activity was measured form whole-cell lysates. (d) Sphere-forming assay was performed using 100 cells in c, and the number of spheres formed was counted. The error bars represent S.D. of the biologic triplicates. All experiments presented in this figure are representative of three independent experiments. Please see Supplementary Table 4 for P-values