title: Calcium overload induces C6 rat glioma cell apoptosis in sonodynamic therapy.
abstract: OBJECTIVE
  Our aim was to study calcium overload-induced apoptosis and its relation to reactive oxygen species (ROS) in rat C6 glioma cells after sonodynamic treatment (SDT).
  
  
  METHODS
  Hematoporphyrin monomethyl ether (HMME) was used as the sonosensitizer. The concentration of intracellular Ca(2+) ([Ca(2+)](i)) was measured by fluorometry. Apoptosis and necrosis rates were evaluated by a flow cytometry. Moreover, sarcoplasmic reticulum Ca(2+) -ATPase (SERCA(2)), cytochrome c (cyto-c) and cleaved caspase-3 were investigated by immunoblotting.
  
  
  RESULTS
  Our study indicated that [Ca(2 +)](i) and ROS increased in cells of SDT group, the apoptosis rate, quantity of cyto-c and cleaved caspase-3 markedly increased after SDT. Furthermore, N-Acetyl-L-cysteine (NAC) or 1,2-bisethane-N,N,N',N'-tetraacetic acid tetrakis ester (BAPTA-AM) could decrease the apoptosis rate, the release of cyto-c and cleaved caspase-3 in SDT group, SERCA(2) degradation was found in SDT group and could also be prevented by the addition of NAC.
  
  
  CONCLUSIONS
  Our results show that HMME-SDT can induce C6 cell death through both necrosis and apoptosis. ROS in C6 cells play a decisive role in HMME-SDT-induced cell death. The endoplasmic reticulum (ER) may be a major target of HMME-SDT, ROS can induce SERCA(2) degradation, causing the elevation of [Ca(2+)](i).
authors.affiliation: Department of Neurosurgery, The Fourth College Hospital of Harbin Medical University, Harbin, PR China. doctorlijianhua@163.com
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Li
authors.forename: Wu
authors.initials: W
authors.lastname: Yue
authors.forename: Zheng
authors.initials: Z
authors.lastname: Huang
authors.forename: Zhi-Qiang
authors.initials: ZQ
authors.lastname: Chen
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhan
authors.forename: Fu-Bin
authors.initials: FB
authors.lastname: Ren
authors.forename: Jing-Ye
authors.initials: JY
authors.lastname: Liu
authors.forename: Song-Bin
authors.initials: SB
authors.lastname: Fu
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects*; D002118:Calcium / Q000737:chemistry / Q000378:metabolism*; D053148:Caspase 3 / Q000378:metabolism; D045304:Cytochromes c / Q000378:metabolism; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D005470:Fluorometry; D005910:Glioma / Q000139:chemically induced / Q000378:metabolism / Q000532:radiotherapy*; D006415:Hematoporphyrins / Q000494:pharmacology / Q000627:therapeutic use*; D015151:Immunoblotting; D007425:Intracellular Membranes / Q000737:chemistry / Q000378:metabolism; D009336:Necrosis / Q000378:metabolism / Q000473:pathology; D017319:Photosensitizing Agents / Q000494:pharmacology / Q000627:therapeutic use; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000378:metabolism; D014407:Tumor Cells, Cultured; D014464:Ultrasonic Therapy / Q000379:methods*
chemical_list: D006415:Hematoporphyrins; D017319:Photosensitizing Agents; D017382:Reactive Oxygen Species; C494379:hematoporphyrin monomethyl ether; C070379:1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid acetoxymethyl ester; D004533:Egtazic Acid; D045304:Cytochromes c; D053148:Caspase 3; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D002118:Calcium; D000111:Acetylcysteine