TY - JOUR
T1 - Effect of platinum nanoparticles on cell death induced by ultrasound in human lymphoma U937 cells
AU - Jawaid, Paras
AU - Rehman, Mati Ur
AU - Hassan, Mariame Ali
AU - Zhao, Qing Li
AU - Li, Peng
AU - Miyamoto, Yusei
AU - Misawa, Masaki
AU - Ogawa, Ryohei
AU - Shimizu, Tadamichi
AU - Kondo, Takashi
N1 - Publisher Copyright:
© 2015 Published by Elsevier B.V.
PY - 2016/7/1
Y1 - 2016/7/1
N2 - In this study, we report on the potential use of platinum nanoparticles (Pt-NPs), a superoxide dismutase (SOD)/catalase mimetic antioxidant, in combination with 1 MHz ultrasound (US) at an intensity of 0.4 W/cm2, 10% duty factor, 100 Hz PRF, for 2 min. Apoptosis induction was assessed by DNA fragmentation assay, cell cycle analysis and Annexin V-FITC/PI staining. Cell killing was confirmed by cell counting and microscopic examination. The mitochondrial and Ca2+-dependent pathways were investigated. Caspase-8 expression and autophagy-related proteins were detected by spectrophotometry and western blot analysis, respectively. Intracellular reactive oxygen species (ROS) elevation was detected by flow cytometry, while extracellular free radical formation was assessed by electron paramagnetic resonance spin trapping spectrometry. The results showed that Pt-NPs exerted differential effects depending on their internalization. Pt-NPs functioned as potent free radical scavengers when added immediately before sonication while pre-treatment with Pt-NPs suppressed the induction of apoptosis as well as autophagy (AP), and resulted in enhanced cell killing. Dead cells displayed the features of pyknosis. The exact mode of cell death is still unclear. In conclusion, the results indicate that US-induced AP may contribute to cell survival post sonication. To our knowledge this is the first study to discuss autophagy as a pro-survival pathway in the context of US. The combination of Pt-NPs and US might be effective in cancer eradication.
AB - In this study, we report on the potential use of platinum nanoparticles (Pt-NPs), a superoxide dismutase (SOD)/catalase mimetic antioxidant, in combination with 1 MHz ultrasound (US) at an intensity of 0.4 W/cm2, 10% duty factor, 100 Hz PRF, for 2 min. Apoptosis induction was assessed by DNA fragmentation assay, cell cycle analysis and Annexin V-FITC/PI staining. Cell killing was confirmed by cell counting and microscopic examination. The mitochondrial and Ca2+-dependent pathways were investigated. Caspase-8 expression and autophagy-related proteins were detected by spectrophotometry and western blot analysis, respectively. Intracellular reactive oxygen species (ROS) elevation was detected by flow cytometry, while extracellular free radical formation was assessed by electron paramagnetic resonance spin trapping spectrometry. The results showed that Pt-NPs exerted differential effects depending on their internalization. Pt-NPs functioned as potent free radical scavengers when added immediately before sonication while pre-treatment with Pt-NPs suppressed the induction of apoptosis as well as autophagy (AP), and resulted in enhanced cell killing. Dead cells displayed the features of pyknosis. The exact mode of cell death is still unclear. In conclusion, the results indicate that US-induced AP may contribute to cell survival post sonication. To our knowledge this is the first study to discuss autophagy as a pro-survival pathway in the context of US. The combination of Pt-NPs and US might be effective in cancer eradication.
KW - Apoptosis
KW - Autophagy
KW - Necroptosis
KW - Platinum nanoparticles
KW - Reactive oxygen species
KW - Ultrasound
UR - http://www.scopus.com/inward/record.url?scp=84952905687&partnerID=8YFLogxK
U2 - 10.1016/j.ultsonch.2015.12.013
DO - 10.1016/j.ultsonch.2015.12.013
M3 - Article
C2 - 26964942
AN - SCOPUS:84952905687
SN - 1350-4177
VL - 31
SP - 206
EP - 215
JO - Ultrasonics Sonochemistry
JF - Ultrasonics Sonochemistry
ER -
