Ursolic acid induces apoptosis via Akt/NF-κB signaling suppression in T24 human bladder cancer cells

摘要

The Akt/NF-κB pathway is involved in numerous anti-apoptotic and drug resistance events which occur in various types of bladder cancer. The present study investigated the role of ursolic acid in the regulation of anti-apoptotic Akt and NF-κBp65 signaling. T24 human bladder cancer cells were treated with ursolic acid at final concentrations of 12.5, 25 or 50 μmol/l for 48 h. Quantitative PCR (qPCR) and western blotting were performed to detect mRNA and protein expression, respectively. The results showed that anti-apoptotic phospho-Akt1 (pAkt1), phospho-IκBα (pIκBα), NF-κBp65 and Bcl-2 were inhibited and pro-apoptotic caspase-3 was upregulated in a dose-dependent manner. A 50 μmol/l dose of ursonic acid decreased the mRNA expression levels of anti-apoptotic NF-κBp65 and Bcl-2 0.17 (8.9/52.6)-fold and 0.22 (9.5/42.3)-fold, respectively. The pro-apoptotic caspase-3 mRNA expression levels were upregulated 4.78 (38.7/8.1)-fold. The anti-apoptotic pAkt1, pIκBα, NF-κBp65 and Bcl-2 protein levels were downregulated to 5.1 (blot grayscales vs. control at 32.3), 3.2 (vs. 24.2), 8.5 (vs. 45.1) and 9.2 (vs. 40.3). The protein levels of pro-apoptotic caspase-3 were upregulated to 20.7 (vs. 4.7). The proliferative activity of T24 cells treated with 12.5, 25.0 and 50.0 μmol/l ursolic acid was significantly reduced compared with that of control cells (83.8, 56.2 and 31.5 vs. 97.6%, respectively, P<0.05 for each). In conclusion, ursolic acid is important in inducing apoptosis via the suppression of Akt/NF-κB signaling in T24 human bladder cancer cells and this occurs in a dose-dependent manner. Ursolic acid may therefore serve as a naturally occurring candidate drug for the prevention and treatment of bladder cancer.