1. IGF1 regulates PKM2 function through Akt phosphorylation
- Author
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Barbara Salani a, b, Silvia Ravera c, Adriana Amaro b, Annalisa Salis d, Mario Passalacqua e, f, Enrico Millo d, Gianluca Damonte d, Cecilia Marini b, e, g, Ulrich Pfeffer b, Gianmario Sambuceti b, Renzo Cordera a, and Davide Maggi a
- Subjects
STAT3 Transcription Factor ,Thyroid Hormones ,endocrine system ,Proto-Oncogene Proteins c-akt ,Pyruvate Kinase ,Biology ,PKM2 ,Cell Line ,chemistry.chemical_compound ,Hexokinase ,Report ,Humans ,Glycolysis ,HIF1α ,Insulin-Like Growth Factor I ,Phosphorylation ,Molecular Biology ,Protein kinase B ,Cell Proliferation ,Glucose Transporter Type 1 ,HIF1? ,IGF1 ,IGFIR ,Cell Biology ,Developmental Biology ,Membrane Proteins ,Metabolism ,Hypoxia-Inducible Factor 1, alpha Subunit ,Metformin ,Cell biology ,Glucose ,chemistry ,Biochemistry ,Carrier Proteins ,Dimerization ,Pyruvate kinase - Abstract
Pyruvate kinase M2 (PKM2) acts at the crossroad of growth and metabolism pathways in cells. PKM2 regulation by growth factors can redirect glycolytic intermediates into key biosynthetic pathway. Here we show that IGF1 can regulate glycolysis rate, stimulate PKM2 Ser/Thr phosphorylation and decrease cellular pyruvate kinase activity. Upon IGF1 treatment we found an increase of the dimeric form of PKM2 and the enrichment of PKM2 in the nucleus. This effect was associated to a reduction of pyruvate kinase enzymatic activity and was reversed using metformin, which decreases Akt phosphorylation. IGF1 induced an increased nuclear localization of PKM2 and STAT3, which correlated with an increased HIF1α, HK2, and GLUT1 expression and glucose entrapment. Metformin inhibited HK2, GLUT1, HIF-1α expression and glucose consumption. These findings suggest a role of IGFIR/Akt axis in regulating glycolysis by Ser/Thr PKM2 phosphorylation in cancer cells.
- Published
- 2015
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