Evidence for an Alternative Glycolytic Pathway in Rapidly Proliferating Cells

Dana Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA.
Science (Impact Factor: 33.61). 09/2010; 329(5998):1492-9. DOI: 10.1126/science.1188015
Source: PubMed


Proliferating cells, including cancer cells, require altered metabolism to efficiently incorporate nutrients such as glucose into biomass. The M2 isoform of pyruvate kinase (PKM2) promotes the metabolism of glucose by aerobic glycolysis and contributes to anabolic metabolism. Paradoxically, decreased pyruvate kinase enzyme activity accompanies the expression of PKM2 in rapidly dividing cancer cells and tissues. We demonstrate that phosphoenolpyruvate (PEP), the substrate for pyruvate kinase in cells, can act as a phosphate donor in mammalian cells because PEP participates in the phosphorylation of the glycolytic enzyme phosphoglycerate mutase (PGAM1) in PKM2-expressing cells. We used mass spectrometry to show that the phosphate from PEP is transferred to the catalytic histidine (His11) on human PGAM1. This reaction occurred at physiological concentrations of PEP and produced pyruvate in the absence of PKM2 activity. The presence of histidine-phosphorylated PGAM1 correlated with the expression of PKM2 in cancer cell lines and tumor tissues. Thus, decreased pyruvate kinase activity in PKM2-expressing cells allows PEP-dependent histidine phosphorylation of PGAM1 and may provide an alternate glycolytic pathway that decouples adenosine triphosphate production from PEP-mediated phosphotransfer, allowing for the high rate of glycolysis to support the anabolic metabolism observed in many proliferating cells.

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    • "Although PEP could inhibit SERCA activity and increase its oxidative state, the precise molecular mechanism(s) by which this occurs remains unknown. Possibly PEP directly conjugates to or oxidizes cysteine residues on SERCA or alternatively PEP could serve as a high-energy phosphate donor to phosphorylate SERCA or other proteins that inhibit its activity (Vander Heiden et al., 2010). Future biochemical studies are needed to precisely characterize which residues in SERCA, if any, are modified by PEP. "
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    ABSTRACT: Activated T cells engage aerobic glycolysis and anabolic metabolism for growth, proliferation, and effector functions. We propose that a glucose-poor tumor microenvironment limits aerobic glycolysis in tumor-infiltrating T cells, which suppresses tumoricidal effector functions. We discovered a new role for the glycolytic metabolite phosphoenolpyruvate (PEP) in sustaining T cell receptor-mediated Ca(2+)-NFAT signaling and effector functions by repressing sarco/ER Ca(2+)-ATPase (SERCA) activity. Tumor-specific CD4 and CD8 T cells could be metabolically reprogrammed by increasing PEP production through overexpression of phosphoenolpyruvate carboxykinase 1 (PCK1), which bolstered effector functions. Moreover, PCK1-overexpressing T cells restricted tumor growth and prolonged the survival of melanoma-bearing mice. This study uncovers new metabolic checkpoints for T cell activity and demonstrates that metabolic reprogramming of tumor-reactive T cells can enhance anti-tumor T cell responses, illuminating new forms of immunotherapy. Copyright © 2015 Elsevier Inc. All rights reserved.
    Cell 08/2015; 162(6). DOI:10.1016/j.cell.2015.08.012 · 32.24 Impact Factor
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    • "PGAM knockdown retards cancerous proliferation (Ren et al. 2010; Hitosugi et al. 2012) and provokes premature senescence in primary cells (Kondoh et al. 2005). The cancer-specific isoform pyruvate kinase M2 (PKM2) activates an alternative glycolytic pathway, accompanied by enhancement of PGAM activity (Vander Heiden et al. 2010). Finally, PGAM is implicated in an experimental neoplastic transformation process (Mikawa et al. 2014). "
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    ABSTRACT: Substantially high rate of glycolysis, known as the Warburg effect, is a well-known feature of cancers, and emerging evidence suggests that it supports cancerous proliferation/tumor growth. Phosphoglycerate mutase (PGAM), a glycolytic enzyme, is commonly up-regulated in several cancers, and recent reports show its involvement in the Warburg effect. Here, a comprehensive analysis shows that PGAM is acetylated at lysines 100/106/113/138 in its central region, and a member of the Sirtuin family (class III deacetylase), SIRT2, is responsible for its deacetylation. Over-expression of SIRT2 or mutations at the acetylatable lysines of PGAM attenuates cancer cell proliferation with a concomitant decrease in PGAM activity. We also report that the acetyltransferase PCAF (p300/CBP-associated factor) interacts with PGAM and acetylates its C-terminus, but not the central region. As prior evidence suggests that SIRT2 functions as a tumor suppressor, our results would provide support for the mechanistic basis of this activity.
    Genes to Cells 09/2014; 19(10). DOI:10.1111/gtc.12176 · 2.81 Impact Factor
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    • "The first example entails the phosphoinositide 3-kinase (PI3K)-mediated upregulation of the endoplasmic reticulum enzyme ENTPD5, which, together with cytidine monophosphate kinase-1 and adenylate kinase-1, engages into an ATP-hydrolyzing futile cycle that results in a compensatory increase in aerobic glycolysis (Fang et al., 2010). The second example involves the expression of the cancer-specific M2 variant of pyruvate kinase (PKM2), which was shown to uncouple pyruvate production from ATP generation by stimulating the transfer of the high-energy phosphate of phosphoenolpyruvate to the glycolytic enzyme phosphoglycerate mutase (PGAM) instead of ADP (Vander Heiden et al., 2010). These data suggest that (1) cancer cell proliferation is not associated with increased ATP demands, (2) high rates of aerobic glycolysis can produce sufficient amounts of ATP, and (3) high rates of aerobic glycolysis are possible thanks to the presence of ATPdepleting reactions. "
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    ABSTRACT: Cancer cells exhibit profound metabolic alterations, allowing them to fulfill the metabolic needs that come with increased proliferation and additional facets of malignancy. Such a metabolic transformation is orchestrated by the genetic changes that drive tumorigenesis, that is, the activation of oncogenes and/or the loss of oncosuppressor genes, and further shaped by environmental cues, such as oxygen concentration and nutrient availability. Understanding this metabolic rewiring is essential to elucidate the fundamental mechanisms of tumorigenesis as well as to find novel, therapeutically exploitable liabilities of malignant cells. Here, we describe key features of the metabolic transformation of cancer cells, which frequently include the switch to aerobic glycolysis, a profound mitochondrial reprogramming, and the deregulation of lipid metabolism, highlighting the notion that these pathways are not independent but rather cooperate to sustain proliferation. Finally, we hypothesize that only those genetic defects that effectively support anabolism are selected in the course of tumor progression, implying that cancer-associated mutations may undergo a metabolically convergent evolution.
    Methods in Enzymology 05/2014; 542:1-23. DOI:10.1016/B978-0-12-416618-9.00001-7 · 2.09 Impact Factor
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