title: Photodynamic therapy with talaporfin sodium induces dose-dependent apoptotic cell death in human glioma cell lines.
abstract: OBJECTIVE
  To investigate the kinetics of cell death in human glioma cell lines induced by photodynamic therapy (PDT) with the second-generation photosensitizer talaporfin sodium (TS) and a 664-nm diode laser.
  
  
  METHODS
  Three human glioma cell lines (T98G, A172, U251) were studied. After incubation of the cell lines with various concentrations of TS for 4 h, PDT using diode laser irradiation at 33 mW/cm² and 10 J/cm² was performed. Cell viability and changes in cell morphology were examined by the Cell Counting Kit-8 assay and phase-contrast microscopy, respectively. In addition, to evaluate the pathology of cell death, changes in cell viability after treatment with a caspase activation inhibitor and an autophagy inhibitor were also examined.
  
  
  RESULTS
  In all 3 human glioma cell lines, TS induced dose-dependent cell death. However, the 50% lethal dose of TS varied among these cell lines. The main morphological feature of cell death was shrinkage of the cell body, and the number of cells with this morphological change increased in a time-dependent manner, resulting in cell death. In addition, a dose-dependent improvement in cell viability by the caspase inhibitor Z-VAD-fmk was observed.
  
  
  CONCLUSIONS
  PDT with TS induces dose-dependent apoptosis in human glioma cell lines. However, the sensitivity to PDT varied among the cell lines, indicating a possible difference in the intracellular content of TS, or a difference in the susceptibility to the intracellular oxidative stress caused by PDT.
authors.affiliation: Department of Neurosurgery, Tokyo Medical University, Japan.
authors.forename: Masateru
authors.initials: M
authors.lastname: Tsutsumi
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Miki
authors.forename: Jiro
authors.initials: J
authors.lastname: Akimoto
authors.forename: Jo
authors.initials: J
authors.lastname: Haraoka
authors.forename: Katsuo
authors.initials: K
authors.lastname: Aizawa
authors.forename: Kazuya
authors.initials: K
authors.lastname: Hirano
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Beppu
mesh_terms: D017209:Apoptosis / Q000187:drug effects* / Q000528:radiation effects; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D005910:Glioma / Q000188:drug therapy* / Q000473:pathology*; D006801:Humans; D010778:Photochemotherapy / Q000379:methods*; D011166:Porphyrins / Q000008:administration & dosage*; D011838:Radiation-Sensitizing Agents / Q000008:administration & dosage; D016896:Treatment Outcome
chemical_list: D011166:Porphyrins; D011838:Radiation-Sensitizing Agents; C053434:Talaporfin