scholarly journals Senescence-inducing stress promotes proteolysis of phosphoglycerate mutase via ubiquitin ligase Mdm2

2014 ◽  
Vol 204 (5) ◽  
pp. 729-745 ◽  
Author(s):  
Takumi Mikawa ◽  
Takeshi Maruyama ◽  
Koji Okamoto ◽  
Hitoshi Nakagama ◽  
Matilde E. Lleonart ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Warburg Effect ◽  
Cultured Cells ◽  
Glycolytic Enzyme ◽  
Phosphoglycerate Mutase ◽  
Proliferative Potential ◽  
Downstream Effector ◽  
Direct Binding ◽  
The Warburg Effect

Despite the well-documented clinical significance of the Warburg effect, it remains unclear how the aggressive glycolytic rates of tumor cells might contribute to other hallmarks of cancer, such as bypass of senescence. Here, we report that, during oncogene- or DNA damage–induced senescence, Pak1-mediated phosphorylation of phosphoglycerate mutase (PGAM) predisposes the glycolytic enzyme to ubiquitin-mediated degradation. We identify Mdm2 as a direct binding partner and ubiquitin ligase for PGAM in cultured cells and in vitro. Mutations in PGAM and Mdm2 that abrogate ubiquitination of PGAM restored the proliferative potential of primary cells under stress conditions and promoted neoplastic transformation. We propose that Mdm2, a downstream effector of p53, attenuates the Warburg effect via ubiquitination and degradation of PGAM.

scholarly journals Double genetic disruption of lactate dehydrogenases A and B is required to ablate the “Warburg effect” restricting tumor growth to oxidative metabolism

2018 ◽  
Vol 293 (41) ◽  
pp. 15947-15961 ◽  
Author(s):  
Maša Ždralević ◽  
Almut Brand ◽  
Lorenza Di Ianni ◽  
Katja Dettmer ◽  
Jörg Reinders ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Warburg Effect ◽  
Specific Inhibitor ◽  
Glucose Consumption ◽  
Glycolytic Enzyme ◽  
Double Knockout ◽  
Genetic Block ◽  
The Warburg Effect

Increased glucose consumption distinguishes cancer cells from normal cells and is known as the “Warburg effect” because of increased glycolysis. Lactate dehydrogenase A (LDHA) is a key glycolytic enzyme, a hallmark of aggressive cancers, and believed to be the major enzyme responsible for pyruvate-to-lactate conversion. To elucidate its role in tumor growth, we disrupted both the LDHA and LDHB genes in two cancer cell lines (human colon adenocarcinoma and murine melanoma cells). Surprisingly, neither LDHA nor LDHB knockout strongly reduced lactate secretion. In contrast, double knockout (LDHA/B-DKO) fully suppressed LDH activity and lactate secretion. Furthermore, under normoxia, LDHA/B-DKO cells survived the genetic block by shifting their metabolism to oxidative phosphorylation (OXPHOS), entailing a 2-fold reduction in proliferation rates in vitro and in vivo compared with their WT counterparts. Under hypoxia (1% oxygen), however, LDHA/B suppression completely abolished in vitro growth, consistent with the reliance on OXPHOS. Interestingly, activation of the respiratory capacity operated by the LDHA/B-DKO genetic block as well as the resilient growth were not consequences of long-term adaptation. They could be reproduced pharmacologically by treating WT cells with an LDHA/B-specific inhibitor (GNE-140). These findings demonstrate that the Warburg effect is not only based on high LDHA expression, as both LDHA and LDHB need to be deleted to suppress fermentative glycolysis. Finally, we demonstrate that the Warburg effect is dispensable even in aggressive tumors and that the metabolic shift to OXPHOS caused by LDHA/B genetic disruptions is responsible for the tumors' escape and growth.

The warburg effect and tumour cell survival in human GBMs

2007 ◽  
Vol 30 (4) ◽  
pp. 97 ◽  
Author(s):  
A Wolf ◽  
J Mukherjee ◽  
A Guha
Keyword(s):  
Cytochrome C ◽  
Cell Survival ◽  
Expression Profile ◽  
Tumour Cell ◽  
Warburg Effect ◽  
Glycolytic Enzymes ◽  
Cytochrome C Release ◽  
Apoptotic Pathway ◽  
The Warburg Effect

Introduction: GBMs are resistant to apoptosis induced by the hypoxic microenvironment and standard therapies including radiation and chemotherapy. We postulate that the Warburg effect, a preferential glycolytic phenotype of tumor cells even under aerobic conditions, plays a role in these aberrant pro-survival signals. In this study we quantitatively examined the expression profile of hypoxia-related glycolytic genes within pathologically- and MRI-defined “centre” and “periphery” of GBMs. We hypothesize that expression of hypoxia-induced glycolytic genes, particularly hexokinase 2 (HK2), favours cell survival and modulates resistance to tumour cell apoptosis by inhibiting the intrinsic mitochondrial apoptotic pathway. Methods: GBM patients underwent conventional T1-weighted contrast-enhanced MRI and MR spectroscopy studies on a 3.0T GE scanner, prior to stereotactic sampling (formalin and frozen) from regions which were T1-Gad enhancing (“centre”) and T2-positive, T1-Gad negative (“periphery”). Real-time qRT-PCR was performed to quantify regional gene expression of glycolytic genes including HK2. In vitro functional studies were performed in U87 and U373 GBM cell lines grown in normoxic (21% pO2) and hypoxic (< 1%pO2) conditions, transfected with HK2 siRNA followed by measurement of cell proliferation (BrdU), apoptosis (activated caspase 3/7, TUNEL, cytochrome c release) and viability (MTS assay). Results: There exists a differential expression profile of glycolytic enzymes between the hypoxic center and relatively normoxic periphery of GBMs. Under hypoxic conditions, there is increased expression of HK2 at the mitochondrial membrane in GBM cells. In vitro HK2 knockdown led to decreased cell survival and increased apoptosis via the intrinsic mitochondrial pathway, as seen by increased mitochondrial release of cytochrome-C. Conclusions: Increased expression of HK2 in the centre of GBMs promotes cell survival and confers resistance to apoptosis, as confirmed by in vitro studies. In vivo intracranial xenograft studies with injection of HK2-shRNA are currently being performed. HK2 and possibly other glycolytic enzymes may provide a target for enhanced therapeutic responsiveness thereby improving prognosis of patients with GBMs.

scholarly journals Proton export drives the Warburg Effect

2021 ◽  
Author(s):  
Shonagh Russell ◽  
Liping Xu ◽  
Yoonseok Kam ◽  
Dominique Abrahams ◽  
Bryce Ordway ◽  
...  
Keyword(s):  
Warburg Effect ◽  
Cancer Metabolism ◽  
Aerobic Glycolysis ◽  
Lactate Production ◽  
Glycolytic Enzymes ◽  
Hek293 Cells ◽  
Driver Mutations ◽  
The Warburg Effect

Aggressive cancers commonly ferment glucose to lactic acid at high rates, even in the presence of oxygen. This is known as aerobic glycolysis, or the “Warburg Effect”. It is widely assumed that this is a consequence of the upregulation of glycolytic enzymes. Oncogenic drivers can increase the expression of most proteins in the glycolytic pathway, including the terminal step of exporting H+ equivalents from the cytoplasm. Proton exporters maintain an alkaline cytoplasmic pH, which can enhance all glycolytic enzyme activities, even in the absence of oncogene-related expression changes. Based on this observation, we hypothesized that increased uptake and fermentative metabolism of glucose could be driven by the expulsion of H+ equivalents from the cell. To test this hypothesis, we stably transfected lowly-glycolytic MCF-7, U2-OS, and glycolytic HEK293 cells to express proton exporting systems: either PMA1 (yeast H+-ATPase) or CAIX (carbonic anhydrase 9). The expression of either exporter in vitro enhanced aerobic glycolysis as measured by glucose consumption, lactate production, and extracellular acidification rate. This resulted in an increased intracellular pH, and metabolomic analyses indicated that this was associated with an increased flux of all glycolytic enzymes upstream of pyruvate kinase. These cells also demonstrated increased migratory and invasive phenotypes in vitro, and these were recapitulated in vivo by more aggressive behavior, whereby the acid-producing cells formed higher grade tumors with higher rates of metastases. Neutralizing tumor acidity with oral buffers reduced the metastatic burden. Therefore, cancer cells with increased H+ export increase intracellular alkalization, even without oncogenic driver mutations, and this is sufficient to alter cancer metabolism towards a Warburg phenotype.

scholarly journals Mammalian DET1 Regulates Cul4A Activity and Forms Stable Complexes with E2 Ubiquitin-Conjugating Enzymes

2007 ◽  
Vol 27 (13) ◽  
pp. 4708-4719 ◽  
Author(s):  
Elah Pick ◽  
On-Sun Lau ◽  
Tomohiko Tsuge ◽  
Suchithra Menon ◽  
Yingchun Tong ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Associated Factors ◽  
Cultured Cells ◽  
Negative Regulator ◽  
Polyubiquitin Chain ◽  
Light Responses ◽  
E3 Ligases ◽  
Conjugating Enzymes ◽  
Ubiquitin Conjugating Enzymes

ABSTRACT DET1 (de-etiolated 1) is an essential negative regulator of plant light responses, and it is a component of the Arabidopsis thaliana CDD complex containing DDB1 and COP10 ubiquitin E2 variant. Human DET1 has recently been isolated as one of the DDB1- and Cul4A-associated factors, along with an array of WD40-containing substrate receptors of the Cul4A-DDB1 ubiquitin ligase. However, DET1 differs from conventional substrate receptors of cullin E3 ligases in both biochemical behavior and activity. Here we report that mammalian DET1 forms stable DDD-E2 complexes, consisting of DDB1, DDA1 (DET1, DDB1 associated 1), and a member of the UBE2E group of canonical ubiquitin-conjugating enzymes. DDD-E2 complexes interact with multiple ubiquitin E3 ligases. We show that the E2 component cannot maintain the ubiquitin thioester linkage once bound to the DDD core, rendering mammalian DDD-E2 equivalent to the Arabidopsis CDD complex. While free UBE2E-3 is active and able to enhance UbcH5/Cul4A activity, the DDD core specifically inhibits Cul4A-dependent polyubiquitin chain assembly in vitro. Overexpression of DET1 inhibits UV-induced CDT1 degradation in cultured cells. These findings demonstrate that the conserved DET1 complex modulates Cul4A functions by a novel mechanism.

scholarly journals Biochemical characterization of the mouse muscle-specific enolase: developmental changes in electrophoretic variants and selective binding to other proteins

1997 ◽  
Vol 323 (3) ◽  
pp. 791-800 ◽  
Author(s):  
Tatyana MERKULOVA ◽  
Marguerite LUCAS ◽  
Carole JABET ◽  
Noël LAMANDÉ ◽  
Jean-Denis ROUZEAU ◽  
...  
Keyword(s):  
Biochemical Characterization ◽  
Striated Muscle ◽  
Cell Types ◽  
Glycolytic Enzyme ◽  
Phosphoglycerate Mutase ◽  
Mouse Muscle ◽  
Electrophoretic Variants ◽  
High Affinity

The glycolytic enzyme enolase (EC 4.2.1.11) is active as dimers formed from three subunits encoded by different genes. The embryonic αα isoform remains distributed in many adult cell types, whereas a transition towards ββ and γγ isoforms occurs in striated muscle cells and neurons respectively. It is not understood why enolase exhibits tissue-specific isoforms with very close functional properties. We approached this problem by the purification of native ββ-enolase from mouse hindlimb muscles and by raising specific antibodies of high titre against this protein. These reagents have been useful in revealing a heterogeneity of the β-enolase subunit that changes with in vivo and in vitro maturation. A basic carboxypeptidase appears to be involved in generating an acidic β-enolase variant, and may regulate plasminogen binding by this subunit. We show for the first time that pure ββ-enolase binds with high affinity the adjacent enzymes in the glycolytic pathway (pyruvate kinase and phosphoglycerate mutase), favouring the hypothesis that these three enzymes form a functional glycolytic segment. ββ-Enolase binds with high affinity sarcomeric troponin but not actin and tropomyosin. Some of these binding properties are shared by the αα-isoenolase, which is also expressed in striated muscle, but not by the neuron-specific γγ-enolase. These results support the idea that specific interactions with macromolecules will address muscle enolase isoforms at the subcellular site where ATP, produced through glycolysis, is most needed for contraction. Such a specific targeting could be modulated by post-translational modifications.

scholarly journals Mitochondrial survivin reduces oxidative phosphorylation in cancer cells by inhibiting mitophagy

2020 ◽  
Author(s):  
Amelia R. Townley ◽  
Sally P. Wheatley
Keyword(s):  
Cancer Cells ◽  
Ubiquitin Ligase ◽  
Warburg Effect ◽  
E3 Ubiquitin Ligase ◽  
Inhibitor Of Apoptosis ◽  
Life And Death ◽  
Cellular Life ◽  
Small Pool ◽  
Mitochondrial Turnover ◽  
The Warburg Effect

AbstractSurvivin is a cancer-associated protein that is pivotal for cellular life and death: it is an essential mitotic protein and an inhibitor of apoptosis. In cancer cells, a small pool of survivin localises to the mitochondria, the function of which remains to be elucidated. Here, we report that mitochondrial survivin inhibits the selective form of autophagy, called “mitophagy”, causing an accumulation of respiratory defective mitochondria. Mechanistically the data reveal that survivin prevents recruitment of the E3-ubiquitin ligase Parkin to mitochondria and their subsequent recognition by the autophagosome. The data also demonstrate that, as a consequence of this blockade, cells expressing high levels of survivin have an increased dependency on anaerobic glycolysis. As these effects were found exclusively in cancer cells they suggest that the primary act of mitochondrial survivin is to force cells to implement the “Warburg Effect” by inhibiting mitochondrial turnover.

scholarly journals MicroRNA-16-1-3p Represses Breast Tumor Growth and Metastasis by Inhibiting PGK1-Mediated Warburg Effect

2020 ◽  
Vol 8 ◽  
Author(s):  
Tianxin Ye ◽  
Yingchun Liang ◽  
Deyu Zhang ◽  
Xuewu Zhang
Keyword(s):  
Breast Cancer ◽  
Warburg Effect ◽  
Aerobic Glycolysis ◽  
Phosphoglycerate Kinase ◽  
Glycolytic Enzyme ◽  
Breast Cancer Patients ◽  
Atp Production ◽  
Glycolysis Pathway

The Warburg effect (aerobic glycolysis) is a hallmark of cancer and is becoming a promising target for diagnosis and therapy. Phosphoglycerate kinase 1 (PGK1) is the first adenosine triphosphate (ATP)-generating glycolytic enzyme in the aerobic glycolysis pathway and plays an important role in cancer development and progression. However, how microRNAs (miRNAs) regulate PGK1-mediated aerobic glycolysis remains unknown. Here, we show that miR-16-1-3p inhibits PGK1 expression by directly targeting its 3′-untranslated region. Through inhibition of PGK1, miR-16-1-3p suppressed aerobic glycolysis by decreasing glucose uptake, lactate and ATP production, and extracellular acidification rate, and increasing oxygen consumption rate in breast cancer cells. Aerobic glycolysis regulated by the miR-16-1-3p/PGK1 axis is critical for modulating breast cancer cell proliferation, migration, invasion and metastasis in vitro and in vivo. In breast cancer patients, miR-16-1-3p expression is negatively correlated with PGK1 expression and breast cancer lung metastasis. Our findings provide clues regarding the role of miR-16-1-3p as a tumor suppressor in breast cancer through PGK1 suppression. Targeting PGK1 through miR-16-1-3p could be a promising strategy for breast cancer therapy.

Targeting the Warburg Effect in cancer; relationships for 2-arylpyridazinones as inhibitors of the key glycolytic enzyme 6-phosphofructo-2-kinase/2,6-bisphosphatase 3 (PFKFB3)

2014 ◽  
Vol 22 (3) ◽  
pp. 1029-1039 ◽  
Author(s):  
Darby G. Brooke ◽  
Ellen M. van Dam ◽  
Colin K.W. Watts ◽  
Amanda Khoury ◽  
Marie A. Dziadek ◽  
...  
Keyword(s):  
Warburg Effect ◽  
Glycolytic Enzyme ◽  
The Warburg Effect

scholarly journals Lysine 53 Acetylation of Cytochrome c in Prostate Cancer: Warburg Metabolism and Evasion of Apoptosis

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 802
Author(s):  
Viktoriia Bazylianska ◽  
Hasini A. Kalpage ◽  
Junmei Wan ◽  
Asmita Vaishnav ◽  
Gargi Mahapatra ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cytochrome C ◽  
Warburg Effect ◽  
Structural Features ◽  
Intrinsic Apoptosis ◽  
Metabolic Switch ◽  
Cancer Hallmarks ◽  
Dynamics Simulations ◽  
The Warburg Effect

Prostate cancer is the second leading cause of cancer-related death in men. Two classic cancer hallmarks are a metabolic switch from oxidative phosphorylation (OxPhos) to glycolysis, known as the Warburg effect, and resistance to cell death. Cytochrome c (Cytc) is at the intersection of both pathways, as it is essential for electron transport in mitochondrial respiration and a trigger of intrinsic apoptosis when released from the mitochondria. However, its functional role in cancer has never been studied. Our data show that Cytc is acetylated on lysine 53 in both androgen hormone-resistant and -sensitive human prostate cancer xenografts. To characterize the functional effects of K53 modification in vitro, K53 was mutated to acetylmimetic glutamine (K53Q), and to arginine (K53R) and isoleucine (K53I) as controls. Cytochrome c oxidase (COX) activity analyzed with purified Cytc variants showed reduced oxygen consumption with acetylmimetic Cytc compared to the non-acetylated Cytc (WT), supporting the Warburg effect. In contrast to WT, K53Q Cytc had significantly lower caspase-3 activity, suggesting that modification of Cytc K53 helps cancer cells evade apoptosis. Cardiolipin peroxidase activity, which is another proapoptotic function of the protein, was lower in acetylmimetic Cytc. Acetylmimetic Cytc also had a higher capacity to scavenge reactive oxygen species (ROS), another pro-survival feature. We discuss our experimental results in light of structural features of K53Q Cytc, which we crystallized at a resolution of 1.31 Å, together with molecular dynamics simulations. In conclusion, we propose that K53 acetylation of Cytc affects two hallmarks of cancer by regulating respiration and apoptosis in prostate cancer xenografts.

Sign in / Sign up

Export Citation Format

Share Document