title: Cytotoxicity and type of cell death induced by midazolam in human oral normal and tumor cells.
abstract: BACKGROUND
  Intravenous anesthetics have been used during the treatment of various malignant tumors, however, their effects on oral tissues is not well-understood. In the present study, the cytotoxicity of five intravenous anesthetics towards oral tumor and normal cells was compared.
  
  
  METHODS
  Tumor specificity index was determined by the ratio of the mean 50% cytotoxic concentration for normal cells to that for tumor cells. Apoptosis induction was monitored by internucleosomal DNA fragmentation and caspase-3, -8, and -9 activation. Fine cell structure was observed under transmission electron microscopy.
  
  
  RESULTS
  Benzodiazepines (midazolam and diazepam) exhibited higher cytotoxicity than barbiturates (thiopental and thiamylal), whereas propofol had the intermediate range of cytotoxicity. Midazolam showed the highest cytotoxicity. HL-60 cells were the most sensitive to midazolam, followed by epidermal keratinocytes, oral squamous cell carcinoma (OSCC), glioblastoma and then oral normal cells. Midazolam did not induce the production of apoptosis markers such as internucleosomal DNA fragmentation and activation of caspase-3, -8 and -9, but did induce the appearance of many vacuoles, mitochondrial swelling and cell membrane rupture in OSCC cell lines (HSC-2 and HSC-4) cells. The cytotoxicity of midazolam was not reduced by pre-treatment with autophagy inhibitors (3-methyladenine and bafilomycin A1).
  
  
  CONCLUSIONS
  These results suggest that midazolam may induce necrotic cell death, rather than apoptosis or autophagy, in OSCC cell lines.
authors.affiliation: Division of Anesthesiology, Meikai University School of Dentistry, Sakado, Saitama 350-0283, Japan.
authors.forename: Seika
authors.initials: S
authors.lastname: Ohno
authors.forename: Katsue
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Shigenori
authors.initials: S
authors.lastname: Uchida
authors.forename: Osamu
authors.initials: O
authors.lastname: Amano
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sakagami
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nagasaka
mesh_terms: D018686:Anesthetics, Intravenous / Q000633:toxicity*; D002294:Carcinoma, Squamous Cell / Q000473:pathology* / Q000648:ultrastructure; D016923:Cell Death / Q000187:drug effects; D045744:Cell Line, Tumor; D053938:DNA Fragmentation / Q000187:drug effects; D003975:Diazepam / Q000633:toxicity; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D046529:Microscopy, Electron, Transmission; D008874:Midazolam / Q000633:toxicity*; D009062:Mouth Neoplasms / Q000473:pathology* / Q000648:ultrastructure*; D009336:Necrosis; D015742:Propofol / Q000633:toxicity; D013840:Thiamylal / Q000633:toxicity; D013874:Thiopental / Q000633:toxicity
chemical_list: D018686:Anesthetics, Intravenous; D013840:Thiamylal; D013874:Thiopental; D003975:Diazepam; D008874:Midazolam; D015742:Propofol