title: Oridonin induces apoptosis and cell cycle arrest of gallbladder cancer cells via the mitochondrial pathway.
abstract: BACKGROUND
  Gallbladder cancer is the most frequent malignancy of the bile duct with high aggressive and extremely poor prognosis. The main objective of the paper was to investigate the inhibitory effects of oridonin, a diterpenoid isolated from Rabdosia rubescens, on gallbladder cancer both in vitro and in vivo and to explore the mechanisms underlying oridonin-induced apoptosis and cell cycle arrest.
  
  
  METHODS
  The anti-tumor activity of oridonin on SGC996 and NOZ cells was assessed by the MTT and colony forming assays. Cell cycle changes were detected by flow cytometric analysis. Apoptosis was detected by annexin V/PI double-staining and Hoechst 33342 staining assays. Loss of mitochondrial membrane potential was observed by Rhodamine 123 staining. The in vivo efficacy of oridonin was evaluated using a NOZ xenograft model in athymic nude mice. The expression of cell cycle- and apoptosis-related proteins in vitro and in vivo was analyzed by western blot analysis. Activation of caspases (caspase-3, -8 and -9) was measured by caspases activity assay.
  
  
  RESULTS
  Oridonin induced potent growth inhibition, S-phase arrest, apoptosis, and colony-forming inhibition in SGC996 and NOZ cells in a dose-dependent manner. Intraperitoneal injection of oridonin (5, 10, or 15 mg/kg) for 3 weeks significantly inhibited the growth of NOZ xenografts in athymic nude mice. We demonstrated that oridonin regulated cell cycle-related proteins in response to S-phase arrest by western blot analysis. In contrast, we observed inhibition of NF-κB nuclear translocation and an increase Bax/Bcl-2 ratio accompanied by activated caspase-3, caspase-9 and PARP-1 cleavage after treatment with oridonin, which indicate that the mitochondrial pathway is involved in oridonin-mediated apoptosis.
  
  
  CONCLUSIONS
  Oridonin possesses potent anti-gallbladder cancer activities that correlate with regulation of the mitochondrial pathway, which is critical for apoptosis and S-phase arrest. Therefore, oridonin has potential as a novel anti-tumor therapy for the treatment of gallbladder cancer.
authors.forename: Runfa
authors.initials: R
authors.lastname: Bao
authors.forename: Yijun
authors.initials: Y
authors.lastname: Shu
authors.forename: Xiangsong
authors.initials: X
authors.lastname: Wu
authors.forename: Hao
authors.initials: H
authors.lastname: Weng
authors.forename: Qian
authors.initials: Q
authors.lastname: Ding
authors.forename: Yang
authors.initials: Y
authors.lastname: Cao
authors.forename: Maolan
authors.initials: M
authors.lastname: Li
authors.forename: Jiasheng
authors.initials: J
authors.lastname: Mu
authors.forename: Wenguang
authors.initials: W
authors.lastname: Wu
authors.forename: Qichen
authors.initials: Q
authors.lastname: Ding
authors.forename: Zhujun
authors.initials: Z
authors.lastname: Tan
authors.forename: Tianyu
authors.initials: T
authors.lastname: Liu
authors.forename: Lin
authors.initials: L
authors.lastname: Jiang
authors.forename: Yunping
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Institute of Biliary Tract Disease, Shanghai Jiao Tong University School of Medicine, No, 1665 Kongjiang Road, Shanghai 200092, China. jscsgjf@sina.cn.
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Gu
authors.forename: Yingbin
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D045786:Diterpenes, Kaurane / Q000494:pharmacology*; D005706:Gallbladder Neoplasms / Q000378:metabolism / Q000473:pathology*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D008297:Male; D051379:Mice; D008819:Mice, Nude; D008928:Mitochondria / Q000378:metabolism*; D009374:Neoplasms, Experimental; D015398:Signal Transduction / Q000187:drug effects*; D023041:Xenograft Model Antitumor Assays
chemical_list: D000970:Antineoplastic Agents; D045786:Diterpenes, Kaurane; C011959:oridonin