Content area
Full text
Introduction
Bladder cancer is increasingly common globally and its morbidity and mortality rates are the fourth and seventh highest in men as estimated by the American Cancer Society in 2015, respectively (1). Therefore, bladder cancer is a major burden to public health. In total, ~75% of newly diagnosed bladder cancer cases are non-muscle-invasive bladder cancer (NMIBC) (2,3). The recommended treatment for patients with NMIBC is transurethral resection of bladder tumor. However, bladder cancers have a high recurrence rate, and ~25% of patients with NMIBC develop into muscle-invasive bladder cancer following treatment (4,5). Although numerous chemotherapeutic drugs have been demonstrated to inhibit tumor recurrence and progression, their toxic side effects and chemosensitivity reduce the overall therapeutic effect for patients with NMIBC (6–9). Therefore, the identification of novel adjuvants or alternative agents for patients with NMIBC is urgently required. Previous studies have revealed that certain plants and microorganisms have anticancer effects, often characterized by low toxicity and few side-effects (10,11).
Puerarin is the main isoflavone glycoside isolated from the traditional Chinese herb Radix pueraria lobate (12). Puerarin has been widely used as an antidiuretic, antipyretic and diaphoretic due to its various medicinal properties (12). Previous studies have demonstrated that puerarin may be used to treat neurodegenerative disorders (13,14) and cardio-cerebrovascular disease (15,16). In addition, puerarin may inhibit the apoptosis of human osteoblasts through the extracellular signal-regulated kinase signaling pathway (17). Puerarin may also exert anticancer effects and inhibit the growth of esophageal cancer cells, and this effect is associated with the mitochondrial pathway (18). It also inhibits proliferation and induces apoptosis in glioblastoma (19), gastric cancer (20) and colon cancer (21) cell lines. However, the effect of puerarin on human bladder cancer are unclear, and the underlying mechanisms remain elusive. Therefore, the present study investigated the anticancer effects and potential mechanisms underlying the effect of puerarin on human bladder cancer.
Materials and methods
Cell culture and reagents
Human bladder cancer T24 cell line and its derivative, the EJ cell line, were purchased from the China Center for Type Culture Collection (Wuhan University, Wuhan, China) (22). The cells were maintained in RPMI-1640 medium (Gibco; Thermo Fisher Scientific, Inc., Waltham, MA, USA). Puerarin was purchased from Shandong Fangming Pharmaceutical Group Co., Ltd. (Heze, China; injection grade; Chinese FDA approval...