Figure 6

Effect of intravesical therapy in murine orthotopic bladder tumor model. (A) Female C57BL/6 mice aged 6 wks with tumor implantation were untreated (C) or treated with GFW, BCG, Mito-C or PBS according to the time schedule in Figure 1. After the mice were sacrificed, the urinary system was isolated and photographed. K, U and B indicate the kidney, urethra and bladder, respectively. The bladder volume was calculated by (length × width²)/2. Data are presented as mean ± SEM (n = 7). Significant differences from the control are indicated by *p < 0.05, **p < 0.01, as determined by one-way ANOVA and Dunnett comparison test. (B) After the treatment cycle, the mice were sacrificed and bladder sections were stained with H&E for histopathologic examination. Magnification: 40× (upper panel) and 100× (bottom panel). The urothelium in GFWtreated mice presented a normal uniform appearance. Tumor cells were observed only in the untreated control, BCG-treated, Mito-C-treated and PBS-treated mice. (C) Schematic diagram showing the effects of GFW on cell cycle arrest and apoptosis in MB49 murine bladder cancer cells. Intracellular ROS levels in MB49 cells presented a significant increase in response to GFW treatment with a subsequent rapid, transient activation of ATM/CHK2, followed by an immediate increase in P21 expression. P21 suppressed the activation of cyclin-dependent protein kinase Cdk2, leading to cell cycle arrest at the G1/S transition. In contrast, GFW induced apoptosis in murine bladder cancer MB49 cells via ATM activation, p53 phosphorylation and caspase-3 activation.