Potential therapeutic effects of N-butylidenephthalide from Radix Angelica Sinensis (Danggui) in human bladder cancer cells

BACKGROUND N-butylidenephthalide (BP) isolated from Radix Angelica Sinensis (Danggui) exhibits anti-tumorigenic effect in various cancer cells both in vivo and in vitro. The effect of BP in bladder cancer treatment is still unclear and worth for further investigate. METHODS Changes of patients with bladder cancer after Angelica Sinensis exposure were evaluated by analysis of Taiwan's National Health Insurance Research Database (NHIRD) database. The anti-proliferative effect of BP on human bladder cancer cells was investigated and their cell cycle profiles after BP treatment were determined by flow cytometry. BP-induced apoptosis was demonstrated by Annexin V-FITC staining and TUNEL assay, while the expressions of apoptosis-related proteins were determined by western blot. The migration inhibitory effect of BP on human bladder cancer cells were shown by trans-well and wound healing assays. Tumor model in NOD-SCID mice were induced by injection of BFTC human bladder cancer cells. RESULTS The correlation of taking Angelica sinensis and the incidence of bladder cancer in NHIRD imply that this herbal product is worth for further investigation. BP caused bladder cancer cell death in a time- and dose- dependent manner and induced apoptosis via the activation of caspase-9 and caspase-3. BP also suppressed the migration of bladder cancer cells as revealed by the trans-well and wound healing assays. Up-regulation of E-cadherin and down-regulation of N-cadherin were evidenced by real-time RT-PCR analysis after BP treatment in vitro. Besides, in combination with BP, the sensitivity of these bladder cancer cells to cisplatin increased significantly. BP also suppressed BFTC xenograft tumor growth, and caused 44.2% reduction of tumor volume after treatment for 26 days. CONCLUSIONS BP caused bladder cancer cell death through activation of mitochondria-intrinsic pathway. BP also suppressed the migration and invasion of these cells, probably by modulating EMT-related genes. Furthermore, combination therapy of BP with a lower dose of cisplatin significantly inhibited the growth of these bladder cancer cell lines. The incidence of bladder cancer decreased in patients who were exposed to Angelica sinensis, suggesting that BP could serve as a potential adjuvant in bladder cancer therapy regimen.