title: Calcium overload and in vitro apoptosis of the C6 glioma cells mediated by sonodynamic therapy (hematoporphyrin monomethyl ether and ultrasound).
abstract: The objective of this study was to investigate the role of intracellular calcium overload in the in vitro apoptosis of C6 glioma cells mediated by low level ultrasound and hematoporphyrin monomethyl ether (HMME) therapy. The frequency of ultrasound was optimized by the cell viability assay using 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). The apoptotic rate, reactive oxygen species (ROS) and decreased mitochondrial membrane potential (MMP) were determined by flow cytometry. Morphological changes were observed by the transmission electron microscope. Concentrations of intracellular Ca2+, [Ca2+]i were detected by a confocal microscopic laser scanning, and the release of cytochrome-c (cyt-c) was measured by western blotting.
  
  
  RESULTS
  The SDT-mediated apoptotic effect involved an overload of [Ca2+]i derived from the intra- and extracellular sources during the early progression of apoptotosis. The process was associated with an increased ROS production, a decreased MMP, and a release of cyt-c. In conclusion,the combined use of low level ultrasound and HMME improved the apoptotic rate of C6 glioma cells mediated by ultrasound alone. The [Ca2+]i overload involving activation of mitochondrial signaling played a pivotal role in the SDT-induced apoptosis.
authors.affiliation: Neurosurgery Department, The First Hospital of Yulin, No. 59 of Suide Culture Road, Yulin city, 718000, Shanxi province, China, drdongninghao@163.com.
authors.forename: Dongning
authors.initials: D
authors.lastname: Hao
authors.forename: Yanbin
authors.initials: Y
authors.lastname: Song
authors.forename: Zhen
authors.initials: Z
authors.lastname: Che
authors.forename: Qi
authors.initials: Q
authors.lastname: Liu
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D002118:Calcium / Q000378:metabolism*; D020746:Calcium Channels, L-Type / Q000378:metabolism; D045744:Cell Line, Tumor; D003131:Combined Modality Therapy; D045304:Cytochromes c / Q000378:metabolism; D005110:Extracellular Space / Q000187:drug effects / Q000378:metabolism; D005910:Glioma / Q000473:pathology*; D006415:Hematoporphyrins / Q000494:pharmacology* / Q000627:therapeutic use; D006801:Humans; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D009553:Nimodipine / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism; D014464:Ultrasonic Therapy
chemical_list: D020746:Calcium Channels, L-Type; D006415:Hematoporphyrins; D017382:Reactive Oxygen Species; C494379:hematoporphyrin monomethyl ether; D009553:Nimodipine; D045304:Cytochromes c; D002118:Calcium