Effects of pterostilbene on inducing apoptosis in normal bladder and bladder cancer cells

Bladder cancer is the most common type of urinary tumor. Current research has focused on alternative therapies that protect the bladder. Some studies suggested that cancer can be treated by inducing apoptosis. Therefore, finding new drugs for related or adjuvant treatments has become important. PT is a natural derivative of resveratrol. The antioxidant effects of PT include the scavenging of extracellular ROS and the induction of apoptosis. PT has been shown to induce several types of tumor cell death; however, the detailed mechanism of action remains unclear. The present examined PT's cytotoxicity and apoptosis-inducing abilities as an anti-bladder cancer drug in normal bladder epithelial and bladder cancer cells. Under PT treatment, bladder cancer HTB-9 cells showed a significant apoptotic effect compared to normal bladder epithelial SV-HUC-1 cells in a dose- and time-dependent manner. Fluorescence microscopy, flow cytometry, and western blotting showed a positive correlation with the expression of apoptotic proteins, especially caspase-3. PT promoted the apoptosis of bladder cancer cells in a time- and dose-dependent manner and had no significant effect on normal bladder epithelial cells involved in internal and external apoptotic pathways, especially the internal ones. The results demonstrate the potential of PT to promote apoptotic death in bladder cancer cells, suggesting its possible use as a drug to treat bladder cancer.