title: In vitro antiglioma action of indomethacin is mediated via AMP-activated protein kinase/mTOR complex 1 signalling pathway.
abstract: We investigated the role of the intracellular energy-sensing AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway in the in vitro antiglioma effect of the cyclooxygenase (COX) inhibitor indomethacin. Indomethacin was more potent than COX inhibitors diclofenac, naproxen, and ketoprofen in reducing the viability of U251 human glioma cells. Antiglioma effect of the drug was associated with p21 increase and G2M cell cycle arrest, as well as with oxidative stress, mitochondrial depolarization, caspase activation, and the induction of apoptosis. Indomethacin increased the phosphorylation of AMPK and its targets Raptor and acetyl-CoA carboxylase (ACC), and reduced the phosphorylation of mTOR and mTOR complex 1 (mTORC1) substrates p70S6 kinase and PRAS40 (Ser183). AMPK knockdown by RNA interference, as well as the treatment with the mTORC1 activator leucine, prevented indomethacin-mediated mTORC1 inhibition and cytotoxic action, while AMPK activators metformin and AICAR mimicked the effects of the drug. AMPK activation by indomethacin correlated with intracellular ATP depletion and increase in AMP/ATP ratio, and was apparently independent of COX inhibition or the increase in intracellular calcium. Finally, the toxicity of indomethacin towards primary human glioma cells was associated with the activation of AMPK/Raptor/ACC and subsequent suppression of mTORC1/S6K. By demonstrating the involvement of AMPK/mTORC1 pathway in the antiglioma action of indomethacin, our results support its further exploration in glioma therapy.
authors.affiliation: Neurology Clinic, Military Medical Academy, Belgrade, Serbia.
authors.forename: Aleksandar
authors.initials: A
authors.lastname: Pantovic
authors.affiliation: Institute of Histology and Embryology, School of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: Mihajlo
authors.initials: M
authors.lastname: Bosnjak
authors.affiliation: Institute of Microbiology and Immunology, School of Medicine, University of Belgrade, Dr. Subotica 1, 11000 Belgrade, Serbia.
authors.forename: Katarina
authors.initials: K
authors.lastname: Arsikin
authors.affiliation: Institute of Microbiology and Immunology, School of Medicine, University of Belgrade, Dr. Subotica 1, 11000 Belgrade, Serbia.
authors.forename: Milica
authors.initials: M
authors.lastname: Kosic
authors.affiliation: Institute of Microbiology and Immunology, School of Medicine, University of Belgrade, Dr. Subotica 1, 11000 Belgrade, Serbia.
authors.forename: Milos
authors.initials: M
authors.lastname: Mandic
authors.affiliation: Institute of Microbiology and Immunology, School of Medicine, University of Belgrade, Dr. Subotica 1, 11000 Belgrade, Serbia.
authors.forename: Biljana
authors.initials: B
authors.lastname: Ristic
authors.affiliation: Institute of Medical and Clinical Biochemistry, School of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: Jelena
authors.initials: J
authors.lastname: Tosic
authors.affiliation: Clinic of Neurosurgery, Department of Neurooncology, Clinical Centre of Serbia, Belgrade, Serbia.
authors.forename: Danica
authors.initials: D
authors.lastname: Grujicic
authors.affiliation: Institute of Medical and Clinical Biochemistry, School of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Isakovic
authors.affiliation: Institute of Medical and Clinical Biochemistry, School of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: Nikola
authors.initials: N
authors.lastname: Micic
authors.affiliation: Institute of Microbiology and Immunology, School of Medicine, University of Belgrade, Dr. Subotica 1, 11000 Belgrade, Serbia. Electronic address: vtrajkovic@med.bg.ac.rs.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Trajkovic
authors.affiliation: Institute for Biological Research "Sinisa Stankovic", University of Belgrade, Despot Stefan Blvd. 142, 11000 Belgrade, Serbia. Electronic address: buajk@yahoo.com.
authors.forename: Ljubica
authors.initials: L
authors.lastname: Harhaji-Trajkovic
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D000249:Adenosine Monophosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects; D002118:Calcium / Q000378:metabolism; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D005909:Glioblastoma / Q000188:drug therapy / Q000378:metabolism; D005910:Glioma / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007213:Indomethacin / Q000494:pharmacology*; D000076222:Mechanistic Target of Rapamycin Complex 1; D008954:Models, Biological; D046912:Multiprotein Complexes / Q000037:antagonists & inhibitors* / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D015398:Signal Transduction / Q000187:drug effects; D058570:TOR Serine-Threonine Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism
chemical_list: D016861:Cyclooxygenase Inhibitors; D046912:Multiprotein Complexes; D034741:RNA, Small Interfering; D000249:Adenosine Monophosphate; D000255:Adenosine Triphosphate; D000076222:Mechanistic Target of Rapamycin Complex 1; D058570:TOR Serine-Threonine Kinases; D055372:AMP-Activated Protein Kinases; D002118:Calcium; D007213:Indomethacin
keywords: AMPK; Apoptosis; Glioma; Indomethacin; mTOR