title: Pterostilbene induces accumulation of autophagic vacuoles followed by cell death in HL60 human leukemia cells.
abstract: Pterostilbene, a naturally occurring structural analog of resveratrol, has been reported to exert antiproliferative and proapoptotic effects in various cancer types. Recently, it has been demonstrated to induce both autophagy and apoptosis in human bladder and breast cancer cell lines. The aim of this study was to evaluate the effects of pterostilbene on HL60 human leukemia cells. Cell morphology was examined using confocal and electron microscopy. Cell viability was determined by MTT, neutral red uptake and trypan blue exclusion assays. LC3 processing was studied based on Western blotting and immunofluorescence analyses. Flow cytometry was used to study cell cycle distribution, phosphatidylserine externalization, caspase activation, disruption of mitochondrial membrane potential and intracellular production of reactive oxygen species. DNA degradation was examined by gel electrophoresis. We found that treatment of HL60 cells with pterostilbene at the IC90 concentration resulted in the G0/G1 cell cycle arrest. Pterostilbene induced conversion of cytosolic LC3-I to membrane-bound LC3-II and accumulation of large LC3-positive vacuolar structures. Pterostilbene also led to phosphatidylserine externalization, internucleosomal DNA fragmentation, caspase activation and disruption of mitochondrial membrane potential. Moreover, it did not induce oxidative stress. Our results suggest that pterostilbene induces accumulation of autophagic vacuoles followed by cell death in HL60 cells.
authors.affiliation: Department of Histology, Medical University of Gdansk, Gdansk, Poland. ksiedlecka@gumed.edu.pl.
authors.forename: K
authors.initials: K
authors.lastname: Siedlecka-Kroplewska
authors.forename: A
authors.initials: A
authors.lastname: Jozwik
authors.forename: W
authors.initials: W
authors.lastname: Boguslawski
authors.forename: M
authors.initials: M
authors.lastname: Wozniak
authors.forename: A
authors.initials: A
authors.lastname: Zauszkiewicz-Pawlak
authors.forename: J H
authors.initials: JH
authors.lastname: Spodnik
authors.forename: M
authors.initials: M
authors.lastname: Rychlowski
authors.forename: Z
authors.initials: Z
authors.lastname: Kmiec
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D001343:Autophagy / Q000187:drug effects*; D020169:Caspases / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D016923:Cell Death / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D053938:DNA Fragmentation; D018922:HL-60 Cells; D006801:Humans; D007938:Leukemia; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D013267:Stilbenes / Q000494:pharmacology*; D014617:Vacuoles / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents; C477012:MAP1LC3A protein, human; D008869:Microtubule-Associated Proteins; D017382:Reactive Oxygen Species; D013267:Stilbenes; C107773:pterostilbene; D020169:Caspases