TY - UNPB
T1 - PKM2 diverts glycolytic flux in dependence on formate overflow
AU - Benzarti, Mohaned
AU - Oudin, Anais
AU - Viry, Elodie
AU - Gargiulo, Ernesto
AU - Schmoetten, Maryse
AU - Neises, Laura
AU - Pulido, Coralie
AU - Lorenz, Nadia I
AU - Ronellenfitsch, Michael W
AU - Sumpton, David
AU - Warmoes, Marc
AU - Jaeger, Christian
AU - Lesur, Antoine
AU - Paggetti, Jérôme
AU - Moussay, Etienne
AU - Niclou, Simone P.
AU - Letellier, Elisabeth
AU - Meiser, Johannes
PY - 2023/1/23
Y1 - 2023/1/23
N2 - 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.
AB - 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.
U2 - 10.1101/2023.01.23.525168
DO - 10.1101/2023.01.23.525168
M3 - Preprint
T3 - bioRxiv
SP - 2023
EP - 2021
BT - PKM2 diverts glycolytic flux in dependence on formate overflow
ER -