More recent studies showed that lactate … In 1930s, Otto Warburg observed altered metabolism in cancer cells. In addition, Fantin et al. Although the function of this protein is unknown, one could postulate that it may act as a COX4-1/COX4-2 switch, limiting complex I activity in hypoxic tumors. Warburg effect regulation could be an attractive target for developing therapeutic interventions in ASD. Blood vessel density was 2.5 to 3.5-fold higher in VHL (p<0.05) and in SDH (p<0.01) related tumors than in RET and NF1-related tumors (Fig. The associated syndromic lesions and the family history of each case are described in Table 2. The fibroblasts then undergo cellular catabolism, which results in a loss of mitochondrial function and ultimately a switch from aerobic metabolism to glycolysis [49]. Inactivation of SDH also leads to HIF stabilization, through the inhibition of their hydroxylation by prolyl-4-hydroxylases, necessary for their recognition by pVHL [15], [16]. A p value <0.05 was considered statistically significant. Aerobic glycolysis is an inefficient way t … The fibroblast–tumour metabolic coupling proposed to exist in the reverse Warburg effect is analogous to the metabolic symbiosis seen in the brain (Figure 2). 5B). Mitochondria in cancer cells: what is so special about them? Biochem Soc Trans 15 October 2016; 44 (5): 1499–1505. Over the last decade, research has increased our knowledge of cancer, and in 2011, Hanahan and Weinberg extended the list of cancer hallmarks to include metabolic reprogramming/deregulated cellular energetics as an emerging hallmark and potential cancer target [26]. Calibration bar: 50 µm. It thus appears that the stimulation of glycolysis in VHL-PH/PGL is not fully mediated by activation of the HIF pathway, but also depends on an additional function of pVHL. Tumourigenic cells oxidise glucose by fermentation and generate lactate and adenosine triphosphate even in the presence of oxygen (Warburg effect). INSERM, unit 970, Paris, France, Many tumours are characterised by increased levels of GLUTs (particularly GLUT 1 and GLUT 3) and high expression of HK (I and II), which is associated with the increases in 18F-FDG signal compared with surrounding tissues as reviewed in ref. Now Warburg's theory is enjoying a resurrection. Recently, the tumor suppressor p53 was revealed to be a new and unexpected target, stabilized and activated by pVHL [20]. 3C). Our data suggest an unexpected association between pseudohypoxia and loss of p53, which leads to a distinct Warburg effect in VHL-related pheochromocytomas. In vitro studies confirmed that the presence of the VHL protein was required for intact respiratory chain protein content and activities in RCC [8], [9]. This rapid fermentation of glucose by tumors, even in the presence of ample oxygen, was the first biochemical trait assigned to cancer and is known as the Warburg effect. Approximately 25–30% of these tumors occur in the context of a hereditary cancer syndrome [10], one third of which are caused by mutations in the VHL gene. Genes from the KEGG pathway ‘Oxidative phosphorylation’ (hsa00190) were obtained from (http://www.genome.ad.jp/kegg/kegg2.html). This observation is in accordance with most reported studies that showed very little p53 mutations in benign PH/PGL [36]–[38]. 7, Table 1). Interestingly, although SDH patients displayed levels of expression usually comparable to that observed in RET and NF1 tumors, Glut3, HXK-II and LDHA were also significantly overexpressed in this subset of patients (Fig. These observations were however unexpected, notably because positron emission tomography with 2-[(18)F]-fluoro-2-deoxy-D-glucose ([(18)F]-FDG PET) tracing glucose uptake was recently shown to be particularly sensitive for the evaluation of bone metastases in patients harboring SDHB mutations [28]. Analyzed the data: JF JJB LV AdR XJ PR APGR. These data were interpreted as tumourigenicity being dependent on high levels of energy derived from glycolysis. We then tested for the Warburg effect in inherited PH/PGL. The hypothesis is that hydrogen peroxide secreted from the cancer cells leads to oxidative stress in the CAF. These included uncontrolled proliferative signalling, resistance to apoptosis, initiating angiogenesis, acquiring replicative immortality, activating invasion and metastasis and evading growth suppressors. Reductions in gene expression detected by microarray analysis were subtle, and differences never reached a two-fold decrease. Keywords:Warburg’s effect, unification theory, ATP, metabolic treatment, alpha lipoïc acid. The brain is a metabolically demanding organ that gives high PET signals. First postulated by Pavlides et al. Aliquots of 50 µg of protein were separated on SDS-PAGE denaturing gels and transferred to either PVDF (Immobilon-P, Millipore) for SDHB, SDHA and OXPHOS experiments or nitrocellulose membranes (Hybond-ECL, Amersham Biosciences) for p53 and HXK-II experiments. Université Paris Descartes, Faculté de Médecine, Paris, France, The Warburg effect, also known as aerobic glycolysis, is defined as the propensity of cancer cells to take up high levels of glucose and to secrete lactate in the presence of oxygen. Article Transcriptional Regulation of the Warburg Effect in Cancer by SIX1 Graphical Abstract Highlights d SIX1 is a key transcription factor involved in the Warburg effect d SIX1 potentiates the Warburg effect via HBO1 and AIB1 d SIX1 glycolytic function is directly repressed by microRNA- 548a-3p d The miR-548a-3p/Six1 axis regulates the Warburg effect and tumor growth Jean-Jacques Brière, Interestingly, this gene was identified as the first gene up-regulated in a transcriptome analysis of hypoxic neuroblastoma cells, another neural-crest derived tumor that shares a number of features with PH/PGL [27]. A positive group displayed a widespread expression of TIGAR, either throughout the whole tumor sample or heterogeneously, with positive areas adjacent to TIGAR negative regions. Interestingly, SCCR enzymatic activity as measured on these frozen tumor tissues was inversely correlated to the vascularization quantified in the corresponding paraffin-embedded samples (Fig. 3E). (2009) The Warburg Effect Is Genetically Determined in Inherited Pheochromocytomas. INSERM, unit 970, Paris, France, The expression profile of these 200 probe sets was also used to perform a principal component analysis on the 68 tumors and led to classification of patients into three groups: SDH, VHL and RET/NF1 tumors (Fig. COX4-2 was drastically overexpressed in pseudo-hypoxic PH/PGL as compared to RET and NF1 tumors, while COX4-1 was decreased two-fold. Collège de France, Paris, France, In vitro metabolism studies are useful tools, but it only serves to hinder therapeutic translation when non-physiological glucose concentrations up to and including 25 mM glucose are used instead of a physiological concentration of 5 mM (plasma) or <5 mM (tissue). The different mutations are localized in three distinct clusters: SDH (grey), VHL (white) and RET/NF1 (black). Analysis of the underlying mechanism suggests that this phenomenon depends on the activation of the pseudo-hypoxic pathway — most probably mediated by the abnormal stabilization of HIF-2α following VHL inactivation — and the loss of the p53/TIGAR pathway. Sigma-Aldrich presents an article about the Warburg effect, and how it is the enhanced conversion of glucose to lactate observed in tumor cells, even in the presence of normal levels of oxygen. Tumor samples (20 to 30 mg) were powdered under liquid nitrogen. Data are means±SEM, represented as relative to NF1 expression values. A negative group showed no TIGAR labeling in tumor cells. The collection of articles in this Research Topic represents a valuable platform where the Warburg Effect is discussed from different perspectives, including how intrinsic and extrinsic regulatory pathways control aerobic glycolysis in normal and diseased conditions, and appropriately discusses the molecular basis for its inhibition in an array of human diseases. SDHA protein was assayed independently in all PH/PGL. Ponceau staining confirmed equivalent loading of each sample and membranes were then blocked in 5% milk in TBST buffer, and probed with the primary antibody. VOLUME: 8 ISSUE: 3 Author(s):Miguel Lopez-Lazaro Affiliation:Department of Pharmacology,Faculty of Pharmacy, C/ Profesor Garcia Gonzalez, 41012 Sevilla, Spain. The glycolysis pathway genes comprised glucose transporters, glycolytic enzymes, lactate dehydohygenase and lactate transporter, as well as TIGAR. Glucose is a crucial molecule in energy production and produces different end products in non-tumourigenic- and tumourigenic tissue metabolism. In normal cells, nuclear p53 expression is usually below the detection level of immunohistochemistry. is probably due to a greater reliance of the cancer cells on mitochondrial respiration for energy production when cultured on reduced glucose conditions. Warburg's original work indicated that while glucose uptake and lactate production are greatly elevated, a cancer cell's rate of mitochondrial respiration is similar to that of normal cells [ 1 , 2 ]. However, how the Warburg effect is directly regulated is largely unknown. The chips were scanned with a GCOS 1.4. Glycolysis was stimulated in all VHL samples but not in SDH tumors, and it appeared that stimulation of the HIF pathway could not account for this phenomenon. Pivotal research in the 1920s by Warburg and Cori demonstrated that cancer avidly consumes glucose and excretes lactate [1,2]. OCR and ECAR are expressed as changes in fluorescence life time/h/75 000 cells (n = 3). Again, such defects were not observed in tumors that retain the ability to degrade HIFs in normoxia (i.e. 3A). J. Mol. There was no difference in HIF-1α mRNA levels between the different types of tumors studied. Frozen tissues were lysed in protein extraction buffer (25 mM Tris, 100 mM NaCl, 0.5% NP40, 0.5% deoxycholic acid, 5 mM EDTA, protease inhibitor cocktail (Sigma)). Proteins of complexes I to IV were less abundant in SDH- and VHL-mutated tumors than in PH/PGL harboring NF1 and RET mutations, but complex V was relatively similar in all patients (Fig. Statistical analyses were performed using the Stat View software (SAS Institute Inc.). Succinate cytochrome c reductase activity (SCCR, complex II + III) was measured in tumor homogenates: individual SDHB and SDHA protein expression followed SDH enzymatic activity. Wrote the paper: JF PR APGR. Cancer cells rewire their metabolism to promote growth, survival, proliferation, and long-term maintenance. and A.P.G.R.]. 2B). Two patients had a NF1 phenotype. Université Paris Descartes, Faculté de Médecine, Paris, France, The excessive glucose often found in cell culture media can decrease mitochondrial respiration, allowing aerobic glycolysis to predominate. Microarray evaluation of HIF-1α (B) and HIF-2α (C) expression between SDH, VHL, RET and NF1 tumors. (C) Correlation between vascular density and SCCR enzymatic values for individual patients. A finding highly relevant to the situation in vivo is that when cultured under low glucose (1 mM) conditions, all cancer lines tested show high–moderate OCR with very little ECAR (glycolysis). Surprisingly, we observed that HXK-II was expressed in all VHL samples but was at the threshold of detection in all RET, NF1 and SDH tumors (Fig. The common feature of this altered metabolism is the increased glucose uptake and fermentation of glucose to lactate. Title:The Warburg Effect on Cancer Cells Survival: the Role of Sugar Starvation in Cancer Therapy VOLUME: 15 Author(s):Wissam Zam*, Imtissal Ahmed and Haneen Yousef Affiliation:Tartous University, Faculty of Pharmacy, Department of Analytical and Food chemistry.Tartous, Tartous University, Faculty of Pharmacy, Department of Analytical and Food chemistry. In 1930, the biochemist Otto Warburg proposed that cancer was caused by defects in oxidative phosphorylation (OXPHOS) or aerobic respiration in the mitochondria; this would force the cell to shift to an anaerobic energy generation process, glycolysis, despite aerobic conditions [1], [2]. In contrast, HIF-2α was expressed at a much higher level both in the nucleus and cytoplasm of tumor cells from all 8 SDH samples and 7 out of 10 VHL PH/PGL. We thus compared the expression of both HIFs using genome-wide expression micro-array in a population of 68 inherited PH/PGL (28 VHL, 9 NF1, 9 RET, 17 SDHB, 3 SDHD and 2 SDHC) (Fig. The Warburg effect is not consistent across all tumours, and the phenomenon of aerobic glycolysis has now been challenged by several groups with many cell lines reported as having mitochondrial function [16–18]. Lactate and pyruvate, the end products of glycolysis, are highly produced by cancer cells even in the presence of oxygen. The pVHL protein is an E3 ligase recognition factor, and its key function is the ubiquitination and subsequent degradation of the α subunit of HIF-1 and -2 in normoxia [7]. The Warburg Effect. Université Paris Descartes, Faculté de Médecine, Paris, France, The Warburg effect is not a universal feature of cancer, and similarly the reverse Warburg is not universal in all tumours. They provide a pertinent explanation for the specific activation of glycolysis in VHL-related PH/PGL. here. In ref. This work also summarizes two key discoveries, one of which relates to hexokinase-2 (HK2), a major player in both the “Warburg effect” and cancer cell immortalization. Unlike its activity on HIF proteins, VHL binding to p53 suppresses Mdm2-mediated ubiquitination and nuclear export and thereby leads to p53 stabilization. However, different tumour populations have different bioenergetic alterations in order to meet their high energy requirement; the Warburg effect is not consistent across all cancer types. COX4I2 was overexpressed 25- and 45-fold in SDH and VHL tumors vs NF1, respectively. [19]). J. Mol. Here, we show that PH/PGL susceptibility genes influence the complex cellular balance between angiogenesis, electron transport and glycolysis, which are regulated by two master genes, HIF and p53. Stringent criteria for RNA quality were applied to rule out degradation, especially a 28 s/18 s ratio above 1.5. This review will discuss the metabolic reprogramming of cancer, possible explanations for the high glucose consumption in cancer cells observed by Warburg, and suggest key experimental practices we should consider when studying the metabolism of cancer. Yes In this study, we investigated whether there is an increased Warburg effect in VHL-related PH/PGL, mediated by the pseudo-hypoxic drive. 21, no. The Authors declare that there are no competing interests associated with the manuscript. An increase in HIF-2α mRNA expression has previously been reported in VHL PH/PGL [13]. Research Article Inflammation Therapeutics Open Access | 10.1172/jci.insight.138949. ***p<0.001. were supported by the Association Française contre les Myopathies and the Association contre les Maladies Mitochondriales. 18F-FDG is transported into cells by glucose transporters (GLUTs) and phosphorylated by hexokinase (HK) to 18F-FDG-6-phosphate (18F-FDG-6-P). Tumours above a certain size label strongly with this approach, and it is used to identify the presence of solid tumours and the effectiveness of treatments. Article Transcriptional Regulation of the Warburg Effect in Cancer by SIX1 Graphical Abstract Highlights d SIX1 is a key transcription factor involved in the Warburg effect d SIX1 potentiates the Warburg effect via HBO1 and AIB1 d SIX1 glycolytic function is directly repressed by microRNA- 548a-3p d The miR-548a-3p/Six1 axis regulates the Warburg effect and tumor growth Keywords: the Warburg effect, PGK1, miR-16-1-3p, cell proliferation, metastasis Citation: Ye T, Liang Y, Zhang D and Zhang X (2021) Corrigendum: MicroRNA-16-1-3p Represses Breast Tumor Growth and Metastasis by Inhibiting PGK1-Mediated Warburg Effect. No, Is the Subject Area "Microarrays" applicable to this article? For each sample, total blood vessels were counted in eight randomly chosen fields of 0.125 mm2. https://doi.org/10.1371/journal.pone.0007094.g003. In the process, uric acid may facilitate carcinogenesis by inhibiting the TCA cycle, stimulating cell proliferation by mitochondrial ROS, and blocking fatty acid oxidation. Although its mode of action on cancer cells in vivo is not entirely clear, mitochondrial studies suggest that metformin can directly impair complex I of the respiratory chain [37,38]. Because aerobic glycolysis is inefficient, it maintains adequate energy supplies through increased glucose flux which can be imaged using F 18 labeled deoxy-d-glucose and Positron Emission Tomography (FdG-PET). Université Paris Descartes, Faculté de Médecine, Paris, France, We performed MXI-1 and c-Myc immunohistochemistry (data not shown) and analyzed MXI-1 and PGC1-β mRNA expression by microarray, but such experiments led to negative results. (A) Hexokinase-II protein is detected in all VHL PH/PGL but is hardly detectable in RET, NF1 and SDH samples. This augmentation would be sufficient to explain the high sensitivity of SDH tumors to [(18)F]-FDG PET and confirms that such approach is indeed relevant for the clinical evaluation of SDHB-related patients. The membranes were then incubated with horseradish peroxidase-linked secondary antibodies (Amersham Biosciences, 1/5000), and bound antibodies were visualized using ECL Plus reagent (Amersham Biosciences). VOLUME: 8 ISSUE: 3 Author(s):Miguel Lopez-Lazaro Affiliation:Department of Pharmacology,Faculty of Pharmacy, C/ Profesor Garcia Gonzalez, 41012 Sevilla, Spain. AP-HP, Hôpital Cochin, Service d'Anatomie pathologique, Paris, France, Affiliation VHL is a tumor suppressor gene responsible for the VHL disease, a hereditary neoplastic syndrome characterized by a predisposition to RCC, retinal and central nervous system hemangioblastomas, pancreatic cysts and pheochromocytomas [7]. Informed signed consent for germline and somatic DNA analysis was obtained from each patient recruited by the COMETE network, and the study was formally approved by an institutional review board (CPP Paris-Cochin). A possible reason for this is that the microenvironment of the tumour is glycolytic in a phenomenon that has been called the reverse Warburg effect. We compared angiogenesis, mitochondrial metabolism and glycolysis in PH/PGL tissues from patients suffering from VHL disease and patients presenting mutations affecting the SDH, RET or NF1 genes. The Na+/H+-antiporter is upregulated in tumourigenic cells resulting in release of lactate- and … The Warburg effect is caused by tumor cells not only to adapt their metabolism to the demand for and limited supply of oxygen but also to obtain large amounts of nucleotides, amino acids and lipids for excessive proliferation of tumor cells. Other highly metabolically active tissues, such as the brain and heart, also label strongly. It is indisputable that certain features of cancer are indeed hallmarks that are essential for most types of cancer. In 1956, Otto Warburg originally described his observation that cancer cells exhibit high rates of glucose uptake and lactic acid production Similar results are shown in Figure 1, where the oxygen consumption rates (OCRs; mitochondrial respiration) and extracellular acidification rates (ECAR; glycolysis) of a range of cancer cell lines are compared under high (25 mM) and low (1 mM) glucose conditions. OCR and ECAR are plotted to quantify mitochondrial respiration and to give an indication of glycolysis rates. Cancer cells show complex, dynamic behaviour allowing survival even in the most unfavourable conditions of substrate and oxygen stress. Click through the PLOS taxonomy to find articles in your field. Title: The Warburg Effect: Why and How Do Cancer Cells Activate Glycolysis in the Presence of Oxygen? The microenvironment of cancer is ever changing, and cancer cells can and do vary in their metabolic phenotype even within the same tumour mass [56]. Université Paris Descartes, Faculté de Médecine, Paris, France, Affiliations One possible explanation for the discrepancy observed between VHL and SDH tumors for the rest of the glycolytic pathway arises from the capacity of HIF-1α and HIF-2α to regulate the expression of different target genes: HIF-1α is the transcription factor involved in hypoxic induction of glycolysis but HIF-2α does not seem to participate in this process [29]. Patients could be classified into two groups regarding TIGAR expression. Two prominent cancer biologists contend that a shift in energy production from oxidative phosphorylation to glycolysis—the so-called “Warburg effect”—is a fundamental property of cancer cells, not just a byproduct of the cell's transformation into cancer. Modern anti-cancer therapies targeting the epigenetic machinery awaken retroelement expression, inducing anti-viral responses that eliminate tumors through mechanisms not completely understood. Choosing between glycolysis and oxidative phosphorylation: a tumor's dilemma? Specifically, the Warburg Effect describes what happens in cancer cells when, although oxygen is plentiful, the cell shifts in preference of generating ATP away from the efficient oxidative phosphorylation and towards the rapid aerobic glycolysis. We did not detect the expression of either HIF-1α or HIF-2α in RET and NF1 tumors, although both these proteins were present in adjacent adrenal tissues (data not shown). , where cells were incubated under oxygenated conditions in 10 mM C-13-labelled glucose. On mitochondrial respiration and to give an indication of glycolysis specifically observed in these tumors RNA quality applied... Changes in fluorescence life time/h/75 000 cells ( n = 3 ) HIFs. 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