title: Sinoporphyrin sodium, a novel sensitizer, triggers mitochondrial-dependent apoptosis in ECA-109 cells via production of reactive oxygen species.
abstract: BACKGROUND
  Sonodynamic therapy (SDT) is a promising method that uses ultrasound to activate certain chemical sensitizers for the treatment of cancer. The purpose of this study was to investigate the sonoactivity of a novel sensitizer, sinoporphyrin sodium (DVDMS), and its sonotoxicity in an esophageal cancer (ECA-109) cell line.
  
  
  METHODS
  The fluorescence intensity of DVDMS, hematoporphyrin, protoporphyrin IX, and Photofrin II was detected by fluorescence microscopy and flow cytometry. Generation of singlet oxygen was measured using a 1, 3-diphenylisobenzofuran experiment. A 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide assay was used to examine cell viability. Production of reactive oxygen species (ROS) and destabilization of the mitochondrial membrane potential were assessed by flow cytometry. Apoptosis was analyzed using Annexin-PE/7-amino-actinomycin D staining. Confocal microscopy was performed to assess mitochondrial damage and identify release of cytochrome C after treatment. Western blots were used to determine expression of oxidative stress-related and apoptosis-associated protein. Ultrastructural changes in the cell were studied by scanning electron microscopy.
  
  
  RESULTS
  DVDMS showed higher autofluorescence intensity and singlet oxygen production efficiency compared with other photosensitizers in both cancerous and normal cells. Compared with hematoporphyrin, DVDMS-mediated SDT was more cytotoxic in ECA-109 cells. Abundant intracellular ROS was found in the SDT groups, and the cytotoxicity induced by SDT was effectively remitted by ROS scavengers. DVDMS located mainly to the mitochondria of ECA-109 cells, which were seriously damaged after exposure to SDT. Release of cytochrome C, an increased rate of apoptosis, and activated apoptosis protein were detected in the SDT group. In addition, relatively severe cell damage was observed on scanning electron microscopy after treatment with DVDMS and SDT.
  
  
  CONCLUSIONS
  These results suggest that DVDMS could be activated by ultrasound, and that DVDMS mediates SDT-induced mitochondrial-dependent apoptosis in ECA-109 cells via production of ROS.
authors.affiliation: Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry, Ministry of Education, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, People's Republic of China.
authors.forename: Haiping
authors.initials: H
authors.lastname: Wang
authors.affiliation: Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry, Ministry of Education, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, People's Republic of China.
authors.forename: Xiaobing
authors.initials: X
authors.lastname: Wang
authors.affiliation: Qinglong High-Tech Co, Ltd, Yichun, Jiangxi, People's Republic of China.
authors.forename: Shaoliang
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry, Ministry of Education, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, People's Republic of China.
authors.forename: Pan
authors.initials: P
authors.lastname: Wang
authors.affiliation: Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry, Ministry of Education, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, People's Republic of China.
authors.forename: Kun
authors.initials: K
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry, Ministry of Education, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, People's Republic of China.
authors.forename: Quanhong
authors.initials: Q
authors.lastname: Liu
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D002460:Cell Line; D045744:Cell Line, Tumor; D048430:Cell Shape / Q000187:drug effects; D045304:Cytochromes c / Q000378:metabolism; D006801:Humans; D042541:Intracellular Space / Q000737:chemistry / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism*; D011166:Porphyrins / Q000737:chemistry / Q000494:pharmacology*; D011838:Radiation-Sensitizing Agents / Q000737:chemistry / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013016:Sound
chemical_list: D011166:Porphyrins; D011838:Radiation-Sensitizing Agents; D017382:Reactive Oxygen Species; C586896:sinoporphyrin sodium; D045304:Cytochromes c
keywords: ECA-109 cells; apoptosis; mitochondrial damage; reactive oxygen species; sinoporphyrin sodium; sonodynamic therapy