title: The phosphoinositide 3-kinase inhibitor LY294002, decreases aminoacyl-tRNA synthetases, chaperones and glycolytic enzymes in human HT-29 colorectal cancer cells.
abstract: The proposed anticancer drug LY294002, inhibits phosphoinositide-3 kinase (PI3K) that initiates a signalling pathway often activated in colorectal cancer (CRC). The effects of LY294002 (10 μM, 48 h) on the cytosolic, mitochondrial and nuclear proteomes of human HT-29 CRC cells have been determined using iTRAQ (isobaric tag for relative and absolute quantitation) and tandem mass spectrometry (MS/MS). Analysis of cells treated with LY294002 identified 26 differentially abundant proteins that indicate several mechanisms of action. The majority of protein changes were directly or indirectly associated with Myc and TNF-α, previously implicated in CRC progression. LY294002 decreased the levels of 6 aminoacyl-tRNA synthetases (average 0.39-fold) required for protein translation, 5 glycolytic enzymes (average 0.37-fold) required for ATP synthesis, and 3 chaperones required for protein folding. There was a 3.2-fold increase in lysozyme C involved in protein-glycoside hydrolysis. LY294002 increased cytosolic p53 with a concomitant decrease in nuclear p53, suggesting transfer of p53 to the cytosol where apoptosis might be initiated via the intrinsic mitochondrial pathway. Protein changes described here suggest that the anti-angiogenic effects of LY294002 may be related to p53; the mutational status of p53 in CRC may be an important determinant of the efficacy of PI3K inhibitors for treatment.
authors.affiliation: School of Molecular Bioscience, University of Sydney, Sydney, NSW 2006, Australia.
authors.forename: Duthika M
authors.initials: DM
authors.lastname: Mallawaaratchy
authors.forename: Swetlana
authors.initials: S
authors.lastname: Mactier
authors.forename: Kimberley L
authors.initials: KL
authors.lastname: Kaufman
authors.forename: Katherine
authors.initials: K
authors.lastname: Blomfield
authors.forename: Richard I
authors.initials: RI
authors.lastname: Christopherson
mesh_terms: D000255:Adenosine Triphosphate / Q000096:biosynthesis; D000604:Amino Acyl-tRNA Synthetases / Q000378:metabolism*; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D002867:Chromones / Q000494:pharmacology*; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D004354:Drug Screening Assays, Antitumor / Q000379:methods; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006019:Glycolysis / Q000187:drug effects*; D006801:Humans; D018832:Molecular Chaperones / Q000378:metabolism*; D009025:Morpholines / Q000494:pharmacology*; D009389:Neovascularization, Pathologic / Q000188:drug therapy / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D053719:Tandem Mass Spectrometry / Q000379:methods; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: D000255:Adenosine Triphosphate; D000604:Amino Acyl-tRNA Synthetases; D002867:Chromones; D004791:Enzyme Inhibitors; D018832:Molecular Chaperones; D009025:Morpholines; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D016159:Tumor Suppressor Protein p53; C495901:TP53 protein, human; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one