title: Apoptosis of SAS cells induced by sonodynamic therapy using 5-aminolevulinic acid sonosensitizer.
abstract: BACKGROUND
  5-Aminolevulinic acid (ALA) has been used as a photodynamic sensitizer for cancer treatment using photodynamic therapy. However, the light has markedly limited penetration depth. It was found that ALA also responds to low energy ultrasound, which has the capability to penetrate deep into tissues. Therefore, sonodynamic therapy (SDT) is a promising method for noninvasive treatment of tumors embedded deep in the tissue. It is desirable to kill the cancer cells via apoptosis rather than necrosis, and therefore, it is necessary to gain a better understanding of the mechanisms of treating cancer using SDT.
  
  
  METHODS
  The apoptosis of SAS cells induced by pulsed 1.05MHz ultrasound in combination with ALA was investigated in vitro.
  
  
  RESULTS
  The cells exposed to SDT with 10 μg/ml ALA displayed significantly higher apoptosis than cells treated by ultrasound alone. There was notably increased reactive oxygen species (ROS) production in the cells treated by SDT with ALA than by ultrasound alone, resulting in higher lipid peroxidation (LPO) level and more cells losing their mitochondrial membrane potential (MMP).
  
  
  CONCLUSIONS
  ALA-mediated SDT produced strong apoptotic effects on SAS cells, which were mainly related to the excessive intracellular ROS production followed by LPO increase and MMP decrease.
authors.affiliation: Department of Physics and Laboratory of Sono- and Photo-theranostic Technologies, Harbin Institute of Technology, Harbin, Heilongjiang, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Song
authors.forename: Haidong
authors.initials: H
authors.lastname: Cui
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
authors.forename: Jinhua
authors.initials: J
authors.lastname: Zheng
authors.forename: Wenwu
authors.initials: W
authors.lastname: Cao
mesh_terms: D000622:Aminolevulinic Acid / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D003131:Combined Modality Therapy; D005434:Flow Cytometry; D006801:Humans; D015227:Lipid Peroxidation; D020782:Matrix Metalloproteinases / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial; D017319:Photosensitizing Agents / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D014062:Tongue Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D014407:Tumor Cells, Cultured; D014464:Ultrasonic Therapy
chemical_list: D017319:Photosensitizing Agents; D017382:Reactive Oxygen Species; D000622:Aminolevulinic Acid; D020782:Matrix Metalloproteinases