title: Tetrandrine induces apoptosis and triggers caspase cascade in human bladder cancer cells.
abstract: BACKGROUND
  Tetrandrine is known to exert anti-tumor effects, however, little is known about its effect on human bladder carcinoma. In this study, employing two different human bladder cancer cell lines, 5637 and T24, which represent high-risk superficial bladder cancer (5637) and high-grade bladder cancer (T24), we tested tetrandrine-induced apoptosis and growth inhibition in bladder carcinoma cell lines and investigated the possible mechanisms.
  
  
  METHODS
  Growth inhibition and apoptosis induction was determined by MTT assay and flow cytometry analysis, respectively. Activation of caspases were analyzed by Western blotting and caspase colorimetric assay. The collapse of mitochondrial membrane potential (ΔΨ(m)) and subcellular distribution of cytochrome c was determined by JC-1 staining and Western blotting, respectively.
  
  
  RESULTS
  Tetrandrine treatment showed strong growth inhibitory and apoptotic effects on human bladder cancer 5637 and T24 cells in a concentration-dependent manner. Additionally, induction of apoptosis by tetrandrine was associated with a very strong and prominent caspase-9, caspase-8, and caspase-3 activation as well as PARP cleavage. Flow cytometric studies revealed that tetrandrine induced a dose-dependent loss of ΔΨ(m), which was accompanied by the release of cytochrome c from mitochondria to the cytosol.
  
  
  CONCLUSIONS
  Taken together, this study provided the first evidence that tetrandrine imparted inhibitory and apoptotic activity in human bladder cancer cells. The tetrandrine-induced apoptosis might be related to the activation of the caspase cascade and mitochondrial pathway. Our results suggest that tetrandrine merits further in vivo investigation as a novel bladder cancer chemopreventive and chemotherapeutic agent in the clinical setting.
authors.affiliation: Department of Urology, The First Hospital of Xi'an Jiaotong University, Xi'an, China.
authors.forename: Xudong
authors.initials: X
authors.lastname: Li
authors.forename: Bin
authors.initials: B
authors.lastname: Su
authors.forename: Runming
authors.initials: R
authors.lastname: Liu
authors.forename: Dapeng
authors.initials: D
authors.lastname: Wu
authors.forename: Dalin
authors.initials: D
authors.lastname: He
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D044182:Benzylisoquinolines / Q000494:pharmacology*; D002295:Carcinoma, Transitional Cell / Q000188:drug therapy* / Q000473:pathology; D020169:Caspases / Q000378:metabolism*; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D006801:Humans; D008928:Mitochondria / Q000187:drug effects; D001749:Urinary Bladder Neoplasms / Q000188:drug therapy* / Q000473:pathology
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D044182:Benzylisoquinolines; C009438:tetrandrine; D020169:Caspases