title: Sonodynamic therapy induces apoptosis of human leukemia HL-60 cells in the presence of protoporphyrin IX.
abstract: Sonodynamic therapy (SDT) is expected to be a novel therapeutic strategy for tumor. The protoporphyrin IX disodium salt (PpIX), a photosensitizer, can be activated by ultrasound. The present study aims to investigate apoptosis of HL-60 cells induced by PpIX-mediated SDT. 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was adopted to examine cell toxicity. Apoptosis was detected using Annexin V-PE/7-amino-actinomycin D (7-AAD) double staining. Detection of apoptotic bodies was examined by Hoechst33342 (HO) staining. Western blotting was used to analyze the protein of caspase-3 and poly ADP-ribose polymerase (PARP). Intracellular reactive oxygen species (ROS) was detected by a ﬂow cytometer after exposures. Compared with PpIX alone and ultrasound alone groups, the synergistic cytotoxicity of PpIX plus ultrasound were significantly boosted. In addition, as determined by Annexin V-PE/7-AAD staining, SDT significantly induced HL-60 cell apoptosis, the obvious nuclear condensation was also found with HO staining at 4 hours post-SDT treatment. Furthermore, Western blotting showed visible enhancement of caspase-3 and PARP cleavage in this process. Besides, intracellular ROS production was significantly enhanced after SDT. Our findings demonstrate that PpIX-mediated SDT could induce apoptosis on HL-60 cells, suggesting that apoptosis is an important mechanism of cell death induced by PpIX-mediated SDT.
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, China. wangpan@snnu.edu.cn.
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Su
authors.forename: Xiaobing
authors.initials: X
authors.lastname: Wang
authors.forename: Kun
authors.initials: K
authors.lastname: Zhang
authors.forename: Shuang
authors.initials: S
authors.lastname: Yang
authors.forename: Quanhong
authors.initials: Q
authors.lastname: Liu
authors.forename: Albert W
authors.initials: AW
authors.lastname: Leung
authors.forename: Chuanshan
authors.initials: C
authors.lastname: Xu
authors.forename: Pan
authors.initials: P
authors.lastname: Wang
mesh_terms: D017209:Apoptosis / Q000187:drug effects* / Q000528:radiation effects*; D018922:HL-60 Cells; D006801:Humans; D011524:Protoporphyrins / Q000008:administration & dosage*; D011838:Radiation-Sensitizing Agents / Q000008:administration & dosage*; D016896:Treatment Outcome; D014464:Ultrasonic Therapy / Q000379:methods*
chemical_list: D011524:Protoporphyrins; D011838:Radiation-Sensitizing Agents; C028025:protoporphyrin IX