Faculty Opinions recommendation of AMPK is a negative regulator of the Warburg effect and suppresses tumor growth in vivo.

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.

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Decision letter: In vivo genetic dissection of tumor growth and the Warburg effect

10.7554/elife.18126.017 ◽

2016 ◽

Keyword(s):

Tumor Growth ◽

Warburg Effect ◽

Genetic Dissection ◽

The Warburg Effect

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Mito-oncology agent: fermented extract suppresses the Warburg effect, restores oxidative mitochondrial activity, and inhibits in vivo tumor growth

Scientific Reports ◽

10.1038/s41598-020-71118-3 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Gyula Bencze ◽

Szilvia Bencze ◽

Keith D. Rivera ◽

James D. Watson ◽

Laszlo Orfi ◽

...

Keyword(s):

Tumor Growth ◽

Warburg Effect ◽

Mitochondrial Activity ◽

The Warburg Effect

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Hypoxia-dependent expression of MAP17 coordinates the Warburg effect to tumor growth in hepatocellular carcinoma

Journal of Experimental & Clinical Cancer Research ◽

10.1186/s13046-021-01927-5 ◽

2021 ◽

Vol 40 (1) ◽

Author(s):

Fangyuan Dong ◽

Rongkun Li ◽

Jiaofeng Wang ◽

Yan Zhang ◽

Jianfeng Yao ◽

...

Keyword(s):

Hepatocellular Carcinoma ◽

Membrane Protein ◽

Tumor Growth ◽

Rna Sequencing ◽

Warburg Effect ◽

Sequencing Analysis ◽

Tumor Glycolysis ◽

The Warburg Effect ◽

Glycolytic Phenotype

Abstract Background Reprogrammed glucose metabolism, also known as the Warburg effect, which is essential for tumor progression, is regarded as a hallmark of cancer. MAP17, a small 17-kDa non-glycosylated membrane protein, is frequently dysregulated in human cancers. However, its role in hepatocellular carcinoma (HCC) remains largely unknown. Methods Immunohistochemistry was used to analyze the expression pattern of MAP17 in HCC. Loss-of-function and gain-of-function studies were performed to investigate the oncogenic roles of MAP17 in vitro and in vivo. RNA sequencing, co-immunoprecipitation, immunofluorescence and western blotting were used to study the molecular mechanism of MAP17 affecting the tumor growth and glycolytic phenotype of HCC. Results An integrative analysis showed that MAP17, a small 17-kDa non-glycosylated membrane protein, is significantly related to the glycolytic phenotype of hepatocellular carcinoma (HCC). Firstly, we found that MAP17 expression is hypoxia-dependent and predicts a poor prognosis in HCC. Genetic silencing of MAP17 reduced the rate of glucose uptake, lactate release, extracellular acidification rate, and expression of glycolytic genes. Ectopic expression of wild type MAP17 but not its PDZ binding domain mutant MAP17-PDZm increased tumor glycolysis. Further research showed that MAP17 knockdown markedly retarded in vivo tumor growth in HCC. Importantly, attenuation of tumor glycolysis by galactose largely hijacked the growth-promoting role of MAP17 in HCC cells. RNA sequencing analysis revealed that MAP17 knockdown leads to transcriptional changes in the ROS metabolic process, cell surface receptor signaling, cell communication, mitotic cell cycle progression, and regulation of cell differentiation. Mechanistically, MAP17 exerted an increased tumoral phenotype associated with an increase in reactive oxygen species (ROS), which activates downstream effectors AKT and HIF1α to enhance the Warburg effect. In HCC clinical samples, there is a close correlation between MAP17 expression and HIF1α or phosphorated level of AKT. Conclusions Our results show that MAP17 is a novel glycolytic regulator, and targeting MAP17/ROS pathway may be an alternative approach for the prevention and treatment of HCC.

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BAI1 acts as a tumor suppressor in lung cancer A549 cells by inducing metabolic reprogramming via the SCD1/HMGCR module

Carcinogenesis ◽

10.1093/carcin/bgaa036 ◽

2020 ◽

Author(s):

Lei Liu ◽

Li Chai ◽

Jingjing Ran ◽

Ying Yang ◽

Li Zhang

Keyword(s):

Lung Cancer ◽

Tumor Suppressor ◽

Colony Formation ◽

Warburg Effect ◽

Poor Prognosis ◽

A549 Cells ◽

Angiogenesis Inhibitor ◽

Metabolic Reprogramming ◽

The Warburg Effect

Abstract Brain-specific angiogenesis inhibitor 1 (BAI1) is an important tumor suppressor in multiple cancers. However, the mechanisms behind its anti-tumor activity, particularly the relationship between BAI1 and metabolic aberrant of a tumor, remained unveiled. This study aimed to investigate whether BAI1 could inhibit biological functions in lung cancer A549 cells and the critical regulating molecules that induce metabolic reprogramming. Immunohistochemistry staining was performed to analyze whether variations in the expression of BAI1 in tumor tissues contributes to poor prognosis of lung cancer. Overexpressed BAI1 (BAI1-OE-A549) and control (Vector-NC-A549) were generated by lentiviral transfection. Biological function assays (proliferation, apoptosis, colony formation, invasion and in vivo metastasis), as well as metabolic reprogramming (by the Warburg effect and the glycolytic rate), were performed in both groups. Our results indicated that lower levels of BAI1 contributed to poor prognosis of lung cancer patients. Furthermore, overexpressed of BAI1 dramatically inhibited proliferation, migration, invasion, colony formation and in vivo metastasis of A549 cells. The Warburg effect and the Seahorse assay revealed that BAI1-OE induced metabolism reprogramming by inhibiting the Warburg effect and glycolysis. Further exploration indicated that BAI1 induced metabolic reprogramming by upregulating stearoyl-CoA desaturase 1 (SCD1) and inhibited 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR). Our study revealed a novel mechanism through which BAI1 acted as tumor suppressor by inducing metabolic reprogramming via the SCD1 and HMGCR module.

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The Key Role of the WNT/β-Catenin Pathway in Metabolic Reprogramming in Cancers under Normoxic Conditions

Cancers ◽

10.3390/cancers13215557 ◽

2021 ◽

Vol 13 (21) ◽

pp. 5557

Author(s):

Alexandre Vallée ◽

Yves Lecarpentier ◽

Jean-Noël Vallée

Keyword(s):

Tumor Microenvironment ◽

Tumor Growth ◽

Warburg Effect ◽

Target Genes ◽

Glucose Transporter ◽

Aerobic Glycolysis ◽

Lactate Production ◽

Metabolic Reprogramming ◽

Pyruvate Dehydrogenase Kinase ◽

The Warburg Effect

The canonical WNT/β-catenin pathway is upregulated in cancers and plays a major role in proliferation, invasion, apoptosis and angiogenesis. Nuclear β-catenin accumulation is associated with cancer. Hypoxic mechanisms lead to the activation of the hypoxia-inducible factor (HIF)-1α, promoting glycolytic and energetic metabolism and angiogenesis. However, HIF-1α is degraded by the HIF prolyl hydroxylase under normoxia, conditions under which the WNT/β-catenin pathway can activate HIF-1α. This review is therefore focused on the interaction between the upregulated WNT/β-catenin pathway and the metabolic processes underlying cancer mechanisms under normoxic conditions. The WNT pathway stimulates the PI3K/Akt pathway, the STAT3 pathway and the transduction of WNT/β-catenin target genes (such as c-Myc) to activate HIF-1α activity in a hypoxia-independent manner. In cancers, stimulation of the WNT/β-catenin pathway induces many glycolytic enzymes, which in turn induce metabolic reprogramming, known as the Warburg effect or aerobic glycolysis, leading to lactate overproduction. The activation of the Wnt/β-catenin pathway induces gene transactivation via WNT target genes, c-Myc and cyclin D1, or via HIF-1α. This in turn encodes aerobic glycolysis enzymes, including glucose transporter, hexokinase 2, pyruvate kinase M2, pyruvate dehydrogenase kinase 1 and lactate dehydrogenase-A, leading to lactate production. The increase in lactate production is associated with modifications to the tumor microenvironment and tumor growth under normoxic conditions. Moreover, increased lactate production is associated with overexpression of VEGF, a key inducer of angiogenesis. Thus, under normoxic conditions, overstimulation of the WNT/β-catenin pathway leads to modifications of the tumor microenvironment and activation of the Warburg effect, autophagy and glutaminolysis, which in turn participate in tumor growth.

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Proton export drives the Warburg Effect

10.1101/2021.09.20.461019 ◽

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.

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