PKM2 diverts glycolytic flux in dependence on formate overflow

Mohaned Benzarti, Anais Oudin, Elodie Viry, Ernesto Gargiulo, Maryse Schmoetten, Laura Neises, Coralie Pulido, Nadia I Lorenz, Michael W Ronellenfitsch, David Sumpton, Marc Warmoes, Christian Jaeger, Antoine Lesur, Jérôme Paggetti, Etienne Moussay, Simone P. Niclou, Elisabeth Letellier, Johannes Meiser*

*Corresponding author for this work

Research output: Working paperPreprint

Abstract

Throughout the metastatic cascade, cancer cells are faced with harsh metabolic environments and nutritional stresses which apply selection pressure leaving only the most metabolically resilient cells to survive and form metastases. Metabolic characterisation of such cell populations in vitro is currently challenging. Using galactose as a tool compound to mimic glycolytic limitation within the tumour microenvironment of primary and secondary neoplastic sites, we were able to uncover metabolic flexibility and plasticity of cancer cells in vitro. In contrast to the established idea that high glycolytic flux and expression of PKM2 redirects carbons towards anabolic routes such as the pentose phosphate pathway and serine synthesis pathway (SSP), we have discovered by using stable-isotope tracing that also glycolytic limitation results in metabolic rewiring. Surprisingly, despite limited carbon availability and energetic stress, cells induce a near complete block of pyruvate kinase isozyme M2 (PKM2) to divert carbons towards SSP. Simultaneously, TCA cycle flux is sustained and oxygen consumption is increased, both supported by glutamine. Glutamine not only supports TCA cycle flux but also SSP via distinct mechanisms. Due to PKM2 block, malic enzyme exclusively supports TCA cycle flux while mitochondrial phosphoenolpyruvate carboxykinase supports SSP. Moreover, by using genetic modifications of different one-carbon (1C) cycle enzymes, we are able to reverse the PKM2 block suggesting a link between mitochondrial 1C cycle and pyruvate kinase. Thus we show that PKM2 inhibition acts as a branching point to direct glycolytic and glutamine carbons into distinct routes, overall supporting the metabolic plasticity and flexibility of cancer cells.
Original languageEnglish
Pages2023-2021
Number of pages3
DOIs
Publication statusPublished - 23 Jan 2023

Publication series

NamebioRxiv
PublisherCold Spring Harbor Laboratory Press

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