title: Sonodynamic action of pyropheophorbide-a methyl ester in liver cancer cells.
abstract: OBJECTIVE
  This study aimed to investigate the sonodynamic action of pyropheophorbide-a methyl ester (MPPa) in liver cancer cells to explore a novel therapeutic modality.
  
  
  METHODS
  H22 cells were chosen as model cells to investigate the sonodynamic action of MPPa on liver cancer. The MPPa concentration was kept constant at 2 micromol/L, and the cells were subjected to ultrasound exposure at an intensity of 0.97 W/cm(2). Cytotoxicity was investigated 24 hours after ultrasound exposure. Apoptosis was evaluated using flow cytometry with annexin V-fluorescein isothiocyanate and propidium iodine staining and nuclear staining with Hoechst 33258. Reactive oxygen species (ROS) were analyzed using flow cytometry with 2,7-dichlorodihydrofluorescein diacetate staining.
  
  
  RESULTS
  No significant dark cytotoxicity of MPPa was shown in the H22 cells at the concentration of 2 micromol/L. The cell death rate induced by ultrasound treatment was significantly higher in the presence of MPPa than in the absence of it (P < .05). Flow cytometry showed that the sonodynamic action of MPPa significantly increased the early and late apoptotic rates of the H22 cells. Nuclear condensation and an ROS increase were found after sonodynamic treatment.
  
  
  CONCLUSIONS
  Our findings showed that MPPa-mediated sonodynamic action significantly enhanced death of H22 cells and the ROS level, suggesting that MPPa is a novel sonosensitizer and the sonodynamic action of MPPa might be a potential therapeutic modality in the management of liver cancer.
authors.affiliation: Department of Photodynamic and Sonodynamic Therapy, Second Affiliated Hospital, Chongqing Medical University, Chongqing, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Xu
authors.forename: Xinshu
authors.initials: X
authors.lastname: Xia
authors.forename: Xinna
authors.initials: X
authors.lastname: Wang
authors.forename: Chuanshan
authors.initials: C
authors.lastname: Xu
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.forename: Junyan
authors.initials: J
authors.lastname: Xiang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Jiang
authors.forename: Albert Wingnang
authors.initials: AW
authors.lastname: Leung
mesh_terms: D000818:Animals; D004354:Drug Screening Assays, Antitumor; D008113:Liver Neoplasms / Q000473:pathology* / Q000628:therapy*; D051379:Mice; D017319:Photosensitizing Agents; D011166:Porphyrins / Q000627:therapeutic use*; D014407:Tumor Cells, Cultured; D014464:Ultrasonic Therapy / Q000379:methods
chemical_list: D017319:Photosensitizing Agents; D011166:Porphyrins; C452939:pyropheophorbide-a methylester