title: Cell death caused by quinazolinone HMJ-38 challenge in oral carcinoma CAL 27 cells: dissections of endoplasmic reticulum stress, mitochondrial dysfunction and tumor xenografts.
abstract: BACKGROUND
  This investigation clearly clarified the synthesized and antimitotic compound, 2-(3'-methoxyphenyl)-6-pyrrolidinyl-4-quinazolinone (HMJ-38), addressing its target and precise mechanism of action. We hypothesized that HMJ-38 might sensitize apoptotic death of human oral carcinoma CAL 27 cells in vitro and inhibit xenograft tumor growth in vivo.
  
  
  METHODS
  Cell viability was assessed utilizing MTT assay. HMJ-38-treated cells represented DNA fragmentation using agarose gel electrophoresis as further evidenced using TUNEL staining. Flow cytometric analyses, immunoblotting and quantitative RT-PCR were applied for protein and gene expression. Antitumor xenograft study was employed.
  
  
  RESULTS
  HMJ-38 concentration- and time-dependently reduced viability of CAL 27 cells. The effect of intrinsic molecules was signalized during HMJ-38 exposure with disruption of ΔΨm, MPT pore opening and the release of various events from mitochondria undergoing cell apoptosis. HMJ-38 also markedly facilitated G2/M phase arrest. HMJ-38 stimulated the activation of CDK1 activity that modulated phosphorylation on Ser70 of Bcl-2-mediated mitotic arrest and apoptosis. HMJ-38 triggered intracellular Ca(2+) release and activated related pivotal hallmarks of ER stress. HMJ-38 in nude mice bearing CAL 27 tumor xenografts decreased tumor growth. Furthermore, HMJ-38 enhanced caspase-3 gene expression and protein level in xenotransplanted tumors.
  
  
  CONCLUSIONS
  Early roles of mitotic arrest, unfolded protein response and mitochondria-dependent signaling contributed to apoptotic CAL 27 cell demise induced by HMJ-38. In in vivo experiments, HMJ-38 also efficaciously suppressed tumor volume in a xenotransplantation model.
  
  
  CONCLUSIONS
  This finding might fully support a critical event for HMJ-38 via induction of apoptotic machinery and ER stress against human oral cancer cells.
authors.affiliation: Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan.
authors.forename: Chi-Cheng
authors.initials: CC
authors.lastname: Lu
authors.affiliation: Department of Pharmacology, China Medical University, Taichung 40402, Taiwan.
authors.forename: Jai-Sing
authors.initials: JS
authors.lastname: Yang
authors.affiliation: Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan.
authors.forename: Jo-Hua
authors.initials: JH
authors.lastname: Chiang
authors.affiliation: School of Pharmacy, China Medical University, Taichung 40402, Taiwan.
authors.forename: Mann-Jen
authors.initials: MJ
authors.lastname: Hour
authors.affiliation: Department of Radiation Oncology, Chi Mei Medical Center, Tainan 71004, Taiwan.
authors.forename: Kuei-Li
authors.initials: KL
authors.lastname: Lin
authors.affiliation: Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan; Department of Biological Science and Technology, China Medical University, Taichung 40402, Taiwan. Electronic address: thlee@email.nchu.edu.tw.
authors.forename: Tsung-Han
authors.initials: TH
authors.lastname: Lee
authors.affiliation: Department of Biological Science and Technology, China Medical University, Taichung 40402, Taiwan; Department of Biotechnology, Asia University, Taichung 41354, Taiwan. Electronic address: jgchung@mail.cmu.edu.tw.
authors.forename: Jing-Gung
authors.initials: JG
authors.lastname: Chung
mesh_terms: D000818:Animals; D002277:Carcinoma / Q000188:drug therapy*; D016923:Cell Death / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D059865:Endoplasmic Reticulum Stress / Q000187:drug effects*; D064593:Heterografts; D006801:Humans; D051379:Mice; D008928:Mitochondria / Q000187:drug effects / Q000473:pathology; D009062:Mouth Neoplasms / Q000188:drug therapy*; D052999:Quinazolinones / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D052999:Quinazolinones; D017382:Reactive Oxygen Species
keywords: Endoplasmic reticulum stress; HMJ-38; Human oral carcinoma cells; Mitochondrial dysfunction; Tumor xenografts