Figure 6. PUMA mediates the antitumor effect of ZM-447439 in a xenograft model.

(A) Nude mice were injected s.c. with 5×10⁶ WT or PUMA-KO HCT116 cells. After 1 week, mice were treated with 80 mg/kg/d ZM-447439 (i.p. injection) or the control 10% DMSO for 14 consecutive days. Tumor volume at the indicated time points after treatment was calculated and plotted (n=5 in each group). (B) Representative tumors at the end of the experiment in (A). (C) WT and PUMA-KO HCT 116 xenograft tumors were treated with 80 mg/kg/d ZM-447439 or control DMSO by i.p. injection as in (A) for 5 consecutive days. p-p65(S536) and PUMA expression in representative tumors was analyzed by Western blotting. (D) Paraffin-embedded sections from tumors in (C) were analyzed by TUNEL staining. Left, representative TUNEL staining pictures with arrows indicating example TUNEL-positive cells (400×); right, TUNEL-positive cells were counted and plotted. (E) Tumor sections were analyzed by active caspase 3 staining. Left, representative staining pictures arrows indicating example active caspase 3-positive cells (400×); right, active caspase 3-positive cells were counted and plotted. Results of (D) and (E) were expressed as means ±SD.