Figure 6.

(-)-Gossypol potentiates docetaxel in inhibiting tumor growth and inducing apoptosis in xenograft model of human prostate cancer PC-3. A. PC-3 xenograft tumor growth curves. PC-3 cells (5×10⁶) were s.c. injected into the flanks on both sides of each mouse. When the tumors reached 50mm³, the mice were randomized into 5 to 8 mice per group and treated with (-)-gossypol 20mg/kg; docetaxel 7.5 mg/kg; or combination of the both. (-)-Gossypol was administrated p.o. via oral gavage, q.d.; Docetaxel was administrated i.v. once a week for 3 weeks. The average tumor sizes were shown (n =10–16). * P<0.05, **P<0.01, ***P<0.001 compared with docetaxel alone, two-way ANOVA. (n = 14-18). The data shown are the representative results of at least four independent animal experiments. B. Tumor Growth Delay (T-C) analysis. T is the median time (in days) required for the treatment group tumors to reach 750 mg, C is the median time (in days) for the control group tumors to reach 750 mg (T-C value for control group is zero). C-D. The tumor tissues from each treatment group were taken at the end of the 3^rd week and fixed in 10% formalin. The tumor sections were stained for TUNEL using the ApopTag kit. The apoptotic cells have DNA fragmentation and are stained positive as brown nuclei. C. Represented pictures were shown: C (control), TXT (docetaxel), G(-) ((-)-gossypol), TXT+G(-) (docetaxel + (-)-gossypol), All photos are ×400 original. D. Quantification of TUNEL staining positive cells. Positive cells were counted under 400× magnification at 8 different fields, and the average numbers were calculated and plotted. ***P < 0.001 compared with docetaxel alone, t-test.