title: Silencing of Hsp27 and Hsp72 in glioma cells as a tool for programmed cell death induction upon temozolomide and quercetin treatment.
abstract: The aim of the present study was to investigate whether silencing of Hsp27 or Hsp72 expression in glioblastoma multiforme T98G and anaplastic astrocytoma MOGGCCM cells increases their sensitivity to programmed cell death induction upon temozolomide and/or quercetin treatment. Transfection with specific siRNA was performed for the Hsp gene silencing. As revealed by microscopic observation and flow cytometry, the inhibition of Hsp expression was correlated with severe apoptosis induction upon the drug treatment studied. No signs of autophagy were detected. This was correlated with a decreased mitochondrial membrane potential, increased level of cytochrome c in the cytoplasm, and activation of caspase 3 and caspase 9. All these results suggest that the apoptotic signal was mediated by an internal pathway. Additionally, in a large percentage of cells treated with temozolomide, with or without quercetin, granules within the ER system were found, which was accompanied by an increased level of caspase 12 expression. This might be correlated with ER stress. Quercetin and temozolomide also changed the shape of nuclei from circular to "croissant like" in both transfected cell lines. Our results indicate that blocking of Hsp27 and Hsp72 expression makes T98G cells and MOGGCCM cells extremely vulnerable to apoptosis induction upon temozolomide and quercetin treatment and that programmed cell death is initiated by an internal signal.
authors.affiliation: Department of Comparative Anatomy and Anthropology, Maria Curie-Sklodowska University, Akademicka 19, 20-033 Lublin, Poland. Electronic address: jjgil@poczta.umcs.lublin.pl.
authors.forename: Joanna
authors.initials: J
authors.lastname: Jakubowicz-Gil
authors.forename: Ewa
authors.initials: E
authors.lastname: Langner
authors.forename: Dorota
authors.initials: D
authors.lastname: Bądziul
authors.forename: Iwona
authors.initials: I
authors.lastname: Wertel
authors.forename: Wojciech
authors.initials: W
authors.lastname: Rzeski
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D001254:Astrocytoma / Q000188:drug therapy; D001343:Autophagy / Q000187:drug effects; D053454:Caspase 12 / Q000235:genetics / Q000378:metabolism; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism; D053453:Caspase 9 / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D045304:Cytochromes c / Q000378:metabolism; D003606:Dacarbazine / Q000031:analogs & derivatives* / Q000494:pharmacology; D059865:Endoplasmic Reticulum Stress / Q000187:drug effects; D020868:Gene Silencing; D005909:Glioblastoma / Q000188:drug therapy; D055551:HSP27 Heat-Shock Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D050884:HSP72 Heat-Shock Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D006360:Heat-Shock Proteins; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D018832:Molecular Chaperones; D011794:Quercetin / Q000494:pharmacology*; D000077204:Temozolomide
chemical_list: D055551:HSP27 Heat-Shock Proteins; D050884:HSP72 Heat-Shock Proteins; C057725:HSPB1 protein, human; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D003606:Dacarbazine; D045304:Cytochromes c; D011794:Quercetin; C506444:CASP12 protein, human; C505407:CASP3 protein, human; C506433:CASP9 protein, human; D053454:Caspase 12; D053148:Caspase 3; D053453:Caspase 9; D000077204:Temozolomide
keywords: Cell death; ER stress; Gliomas; Hsps; Quercetin; Temozolomide