Paeonia lactiflora Pall inhibits bladder cancer growth involving phosphorylation of Chk2 in vitro and in vivo

Ethnopharmacological relevance: Extracts of Paeonia lactiflora Pall (RPA), a traditional Chinese medicines has been shown to treat cancers. Aim of the study: The purpose of this study is to evaluate the anticancer effect of RPA in urinary bladder carcinoma in vitro and in vivo. Materials and methods: The cell viability was analyzed with DAPI. Flow cytometry and Western blot were used to study the apoptosis and cell cycle related mechanism. A rat model of bladder cancer was induced by N-butyl-N-(4-hydroxybutyl) nitrosamine (OH-BBN). Tumors were analyzed with immunohistochemical analysis. Results: Our data suggested that RPA inhibits growth of bladder cancer via induction of apoptosis and cell cycle arrest. Treatment of TSGH-8301 cells with RPA resulted in G2-M phase arrest that was associated with a marked decline in protein levels of cdc2, cyclin B1, cell division cycle 25B (Cdc25B) and Cdc25 C. We also reported that RPA-mediated growth inhibition of TSGH-8301 cells was correlated with activation of checkpoint kinase 2 (Chk2). Herein, we further evaluated urinary bladder cancer using a model of bladder cancer induced by OH-BBN. Analysis of tumors from RPA-treated rats showed significant decrease in the expression of Bcl2, cyclin D1, and PCNA, and increase in the expression of p-Chk2 (Thr-68). Bax, and Cip1/p21. Conclusion: Our data provide the experimental evidence that RPA could modulate apoptosis in models of bladder cancer. (C) 2011 Elsevier Ireland Ltd. All rights reserved.