title: Apoptosis induction in human glioblastoma multiforme T98G cells upon temozolomide and quercetin treatment.
abstract: Glioblastoma multiforme is the most aggressive primary brain tumour. At the cellular and molecular levels, several mechanisms responsible for apoptosis or autophagy induction are blocked. Identification of molecular targets stimulating cells to initiate programmed cell death should be performed for therapeutic purposes. A promising solution is the combination of temozolomide and quercetin. The aim of our study was to evaluate the effect of both drugs, applied alone and in combinations, on apoptosis and autophagy induction in human glioblastoma multiforme T98G cells. Our results clearly indicate that quercetin and temozolomide induce apoptosis very significantly, having no effect on autophagy induction. At the molecular level, it was correlated with caspase 3 and 9 activation, cytochrome c release from the mitochondrium and a decrease in the mitochondrial membrane potential. Both drugs are also potent Hsp27 and Hsp72 inhibitors. This suggests that the apoptotic signal goes through an internal pathway. Increased expression of caspase 12 and the presence of several granules in the cytoplasm after temozolomide treatment with or without quercetin preceding appearance of apoptosis may suggest that apoptosis is initiated by ER stress. Additionally, it was accompanied by changes in the nuclear morphology from circular to 'croissant like'.
authors.affiliation: Department of Comparative Anatomy and Anthropology, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland. 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: D018906:Antineoplastic Agents, Alkylating / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D001932:Brain Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D053454:Caspase 12 / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D045304:Cytochromes c / Q000378:metabolism; D003606:Dacarbazine / Q000031:analogs & derivatives* / Q000494:pharmacology; D059865:Endoplasmic Reticulum Stress / Q000187:drug effects; D004789:Enzyme Activation; D005909:Glioblastoma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D055551:HSP27 Heat-Shock Proteins / Q000037:antagonists & inhibitors; D050884:HSP72 Heat-Shock Proteins / Q000037:antagonists & inhibitors; D006360:Heat-Shock Proteins; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D018832:Molecular Chaperones; D011794:Quercetin / Q000494:pharmacology*; D000077204:Temozolomide
chemical_list: D018906:Antineoplastic Agents, Alkylating; D000975:Antioxidants; 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; D053454:Caspase 12; D053148:Caspase 3; D053453:Caspase 9; D000077204:Temozolomide