151
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Cooper AJL, Kuhara T. α-Ketoglutaramate: an overlooked metabolite of glutamine and a biomarker for hepatic encephalopathy and inborn errors of the urea cycle. Metab Brain Dis 2014; 29:991-1006. [PMID: 24234505 PMCID: PMC4020999 DOI: 10.1007/s11011-013-9444-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Accepted: 10/21/2013] [Indexed: 01/16/2023]
Abstract
Glutamine metabolism is generally regarded as proceeding via glutaminase-catalyzed hydrolysis to glutamate and ammonia, followed by conversion of glutamate to α-ketoglutarate catalyzed by glutamate dehydrogenase or by a glutamate-linked aminotransferase (transaminase). However, another pathway exists for the conversion of glutamine to α-ketoglutarate that is often overlooked, but is widely distributed in nature. This pathway, referred to as the glutaminase II pathway, consists of a glutamine transaminase coupled to ω-amidase. Transamination of glutamine results in formation of the corresponding α-keto acid, namely, α-ketoglutaramate (KGM). KGM is hydrolyzed by ω-amidase to α-ketoglutarate and ammonia. The net glutaminase II reaction is: L - Glutamine + α - keto acid + H2O → α - ketoglutarate + L - amino acid + ammonia. In this mini-review the biochemical importance of the glutaminase II pathway is summarized, with emphasis on the key component KGM. Forty years ago it was noted that the concentration of KGM is increased in the cerebrospinal fluid (CSF) of patients with hepatic encephalopathy (HE) and that the level of KGM in the CSF correlates well with the degree of encephalopathy. In more recent work, we have shown that KGM is markedly elevated in the urine of patients with inborn errors of the urea cycle. It is suggested that KGM may be a useful biomarker for many hyperammonemic diseases including hepatic encephalopathy, inborn errors of the urea cycle, citrin deficiency and lysinuric protein intolerance.
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Affiliation(s)
- Arthur J L Cooper
- Department of Biochemistry and Molecular Biology, New York Medical College, 15 Dana Road, Valhalla, NY, 10595, USA,
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152
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Li X, Liu X, Xu Y, He Y, Liu J, Xie M. Expression profile of apoptotic and proliferative proteins in hypoxic HUVEC treated with statins. Int J Oncol 2014; 46:677-84. [PMID: 25434456 DOI: 10.3892/ijo.2014.2780] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2014] [Accepted: 11/06/2014] [Indexed: 11/06/2022] Open
Abstract
Vascular endothelial hyperproliferation is involved in the pathophysiological process of angiogenesis, which is indispensable for tumor growth and spread in hypoxic adaptation. There is increasing evidence indicating that statins have potential anti-angiogenesis benefits. However, the intracellular signaling mechanism underlying the effect of statins in vascular endothelial cells is undefined. The present study was conducted to investigate the effect of fluvastatin on cell proliferation and apoptosis in normoxic and hypoxic human umbilical vein endothelial cells (HUVEC). Flow cytometric analyses revealed that statins reversed hypoxia-induced cell proliferation by slowing down G1 to S transition and inducing cell apoptosis. To get further insights into the downstream effects of statins, we measured the expression of various apoptosis-associated proteins in hypoxic HUVEC using human apoptosis antibody array. The results suggested that cell apoptosis was accompanied by upregulation of caspase-3, p27, IGFBP-6 and a decrease of bcl-2, survivin levels. Subsequent studies confirmed the results of array and demonstrated that fluvastatin activated mitochondrial apoptosis through enhancing bax/bcl-2 ratio, releasing cytochrome c, in turn activating caspase-9 and caspase-3, and eventually cleaving PARP. Further experiments showed that inhibition of cell proliferation by fluvastatin was associated with elevated IGFBP-6, p27, p53 levels and reduced survivin, cyclin B1, cyclin D1 and VEGF expression. Taken together, fluvastatin suppressed cell proliferation and induced apoptosis of HUVEC in hypoxia via multiple signaling pathways, providing a theoretical basis for statins in the therapy of cancer.
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Affiliation(s)
- Xiaochen Li
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, P.R. China
| | - Xiansheng Liu
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, P.R. China
| | - Yongjian Xu
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, P.R. China
| | - Yuanzhou He
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, P.R. China
| | - Jin Liu
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, P.R. China
| | - Min Xie
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, P.R. China
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153
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Fleming I. The Pharmacology of the Cytochrome P450 Epoxygenase/Soluble Epoxide Hydrolase Axis in the Vasculature and Cardiovascular Disease. Pharmacol Rev 2014; 66:1106-40. [DOI: 10.1124/pr.113.007781] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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154
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Verdegem D, Moens S, Stapor P, Carmeliet P. Endothelial cell metabolism: parallels and divergences with cancer cell metabolism. Cancer Metab 2014; 2:19. [PMID: 25250177 PMCID: PMC4171726 DOI: 10.1186/2049-3002-2-19] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 08/14/2014] [Indexed: 02/08/2023] Open
Abstract
The stromal vasculature in tumors is a vital conduit of nutrients and oxygen for cancer cells. To date, the vast majority of studies have focused on unraveling the genetic basis of vessel sprouting (also termed angiogenesis). In contrast to the widely studied changes in cancer cell metabolism, insight in the metabolic regulation of angiogenesis is only just emerging. These studies show that metabolic pathways in endothelial cells (ECs) importantly regulate angiogenesis in conjunction with genetic signals. In this review, we will highlight these emerging insights in EC metabolism and discuss them in perspective of cancer cell metabolism. While it is generally assumed that cancer cells have unique metabolic adaptations, not shared by healthy non-transformed cells, we will discuss parallels and highlight differences between endothelial and cancer cell metabolism and consider possible novel therapeutic opportunities arising from targeting both cancer and endothelial cells.
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Affiliation(s)
- Dries Verdegem
- Laboratory of Angiogenesis and Neurovascular link, Vesalius Research Center, Department of Oncology, University of Leuven, Leuven 3000, Belgium ; Laboratory of Angiogenesis and Neurovascular link, Vesalius Research Center, VIB, K.U.Leuven, Campus Gasthuisberg, Herestraat 49, box 912, Leuven 3000, Belgium
| | - Stijn Moens
- Laboratory of Angiogenesis and Neurovascular link, Vesalius Research Center, Department of Oncology, University of Leuven, Leuven 3000, Belgium ; Laboratory of Angiogenesis and Neurovascular link, Vesalius Research Center, VIB, K.U.Leuven, Campus Gasthuisberg, Herestraat 49, box 912, Leuven 3000, Belgium
| | - Peter Stapor
- Laboratory of Angiogenesis and Neurovascular link, Vesalius Research Center, Department of Oncology, University of Leuven, Leuven 3000, Belgium ; Laboratory of Angiogenesis and Neurovascular link, Vesalius Research Center, VIB, K.U.Leuven, Campus Gasthuisberg, Herestraat 49, box 912, Leuven 3000, Belgium
| | - Peter Carmeliet
- Laboratory of Angiogenesis and Neurovascular link, Vesalius Research Center, Department of Oncology, University of Leuven, Leuven 3000, Belgium ; Laboratory of Angiogenesis and Neurovascular link, Vesalius Research Center, VIB, K.U.Leuven, Campus Gasthuisberg, Herestraat 49, box 912, Leuven 3000, Belgium
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155
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Stapor P, Wang X, Goveia J, Moens S, Carmeliet P. Angiogenesis revisited - role and therapeutic potential of targeting endothelial metabolism. J Cell Sci 2014; 127:4331-41. [PMID: 25179598 DOI: 10.1242/jcs.153908] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Clinically approved therapies that target angiogenesis in tumors and ocular diseases focus on controlling pro-angiogenic growth factors in order to reduce aberrant microvascular growth. Although research on angiogenesis has revealed key mechanisms that regulate tissue vascularization, therapeutic success has been limited owing to insufficient efficacy, refractoriness and tumor resistance. Emerging concepts suggest that, in addition to growth factors, vascular metabolism also regulates angiogenesis and is a viable target for manipulating the microvasculature. Recent studies show that endothelial cells rely on glycolysis for ATP production, and that the key glycolytic regulator 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3) regulates angiogenesis by controlling the balance of tip versus stalk cells. As endothelial cells acquire a tip cell phenotype, they increase glycolytic production of ATP for sprouting. Furthermore, pharmacological blockade of PFKFB3 causes a transient, partial reduction in glycolysis, and reduces pathological angiogenesis with minimal systemic harm. Although further assessment of endothelial cell metabolism is necessary, these results represent a paradigm shift in anti-angiogenic therapy from targeting angiogenic factors to focusing on vascular metabolism, warranting research on the metabolic pathways that govern angiogenesis.
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Affiliation(s)
- Peter Stapor
- Laboratory of Angiogenesis and Neurovascular link, Vesalius Research Center, VIB, B-3000 Leuven, Belgium Laboratory of Angiogenesis and Neurovascular link, Department of Oncology, KU Leuven, B-3000 Leuven, Belgium
| | - Xingwu Wang
- Laboratory of Angiogenesis and Neurovascular link, Vesalius Research Center, VIB, B-3000 Leuven, Belgium Laboratory of Angiogenesis and Neurovascular link, Department of Oncology, KU Leuven, B-3000 Leuven, Belgium
| | - Jermaine Goveia
- Laboratory of Angiogenesis and Neurovascular link, Vesalius Research Center, VIB, B-3000 Leuven, Belgium Laboratory of Angiogenesis and Neurovascular link, Department of Oncology, KU Leuven, B-3000 Leuven, Belgium
| | - Stijn Moens
- Laboratory of Angiogenesis and Neurovascular link, Vesalius Research Center, VIB, B-3000 Leuven, Belgium Laboratory of Angiogenesis and Neurovascular link, Department of Oncology, KU Leuven, B-3000 Leuven, Belgium
| | - Peter Carmeliet
- Laboratory of Angiogenesis and Neurovascular link, Vesalius Research Center, VIB, B-3000 Leuven, Belgium Laboratory of Angiogenesis and Neurovascular link, Department of Oncology, KU Leuven, B-3000 Leuven, Belgium
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156
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Evading anti-angiogenic therapy: resistance to anti-angiogenic therapy in solid tumours. Br J Cancer 2014. [DOI: 10.1038/bjc.2014.439] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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157
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Corbet C, Draoui N, Polet F, Pinto A, Drozak X, Riant O, Feron O. The SIRT1/HIF2α axis drives reductive glutamine metabolism under chronic acidosis and alters tumor response to therapy. Cancer Res 2014; 74:5507-19. [PMID: 25085245 DOI: 10.1158/0008-5472.can-14-0705] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Extracellular tumor acidosis largely results from an exacerbated glycolytic flux in cancer and cancer-associated cells. Conversely, little is known about how tumor cells adapt their metabolism to acidosis. Here, we demonstrate that long-term exposure of cancer cells to acidic pH leads to a metabolic reprogramming toward glutamine metabolism. This switch is triggered by the need to reduce the production of protons from glycolysis and further maintained by the NAD(+)-dependent increase in SIRT1 deacetylase activity to ensure intracellular pH homeostasis. A consecutive increase in HIF2α activity promotes the expression of various transporters and enzymes supporting the reductive and oxidative glutamine metabolism, whereas a reduction in functional HIF1α expression consolidates the inhibition of glycolysis. Finally, in vitro and in vivo experiments document that acidosis accounts for a net increase in tumor sensitivity to inhibitors of SIRT1 and glutaminase GLS1. These findings highlight the influence that tumor acidosis and metabolism exert on each other.
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Affiliation(s)
- Cyril Corbet
- Pole of Pharmacology and Therapeutics (FATH), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, Brussels, Belgium
| | - Nihed Draoui
- Pole of Pharmacology and Therapeutics (FATH), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, Brussels, Belgium
| | - Florence Polet
- Pole of Pharmacology and Therapeutics (FATH), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, Brussels, Belgium
| | - Adan Pinto
- Pole of Pharmacology and Therapeutics (FATH), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, Brussels, Belgium
| | - Xavier Drozak
- Molecules, Solids and Reactivity (MOST), Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Olivier Riant
- Molecules, Solids and Reactivity (MOST), Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Olivier Feron
- Pole of Pharmacology and Therapeutics (FATH), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, Brussels, Belgium.
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158
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Ghesquière B, Wong BW, Kuchnio A, Carmeliet P. Metabolism of stromal and immune cells in health and disease. Nature 2014; 511:167-76. [DOI: 10.1038/nature13312] [Citation(s) in RCA: 318] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 04/08/2014] [Indexed: 12/11/2022]
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159
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Choi JW, Kim Y, Lee JH, Kim YS. Prognostic significance of lactate/proton symporters MCT1, MCT4, and their chaperone CD147 expressions in urothelial carcinoma of the bladder. Urology 2014; 84:245.e9-15. [PMID: 24857275 DOI: 10.1016/j.urology.2014.03.031] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 02/27/2014] [Accepted: 03/30/2014] [Indexed: 11/17/2022]
Abstract
OBJECTIVE To investigate the prognostic significance of lactate/proton monocarboxylate transporters MCT1, MCT4, and their chaperone CD147 expressions in urothelial carcinoma of the bladder (UCB). METHODS We examined the expressions of MCT1, MCT4, and CD147 proteins in a total of 360 cases of UCB by immunohistochemistry. The immunohistochemical expressions were quantified using an ImageJ-based analysis program. RESULTS MCT1, MCT4, and CD147 expressions were increased in 130 (36.1%), 168 (46.7%), and 228 (63.3%) UCB cases, respectively. Most tumor cells showed diffuse membranous staining, whereas normal urothelial cells showed negative or weak staining. High levels of MCT1 expression correlated with high World Health Organization grade (P<.001), advanced tumor node metastasis (TNM) stage (P<.001), nonpapillary growth type (P<.001), and lymphatic tumor invasion (P=.010), whereas high levels of MCT4 expression did not significantly correlate with any of these variables. High CD147 expression was associated with high World Health Organization grade (P<.001), advanced tumor node metastatis stage (P<.001), and nonpapillary growth type (P=.003). Univariate analyses revealed that high MCT1 (P<.001) and CD147 (P=.029) expressions were associated with poor overall survival and that high MCT4 expression was correlated with poor recurrence-free survival (P=.036). Multivariate analyses revealed that high MCT1 and MCT4 expressions were independent prognostic factors for poor overall survival and poor recurrence-free survival, respectively, in UCB patients. CONCLUSION Our results indicate that increased MCT1, MCT4, and CD147 expressions have prognostic implications in UCB and suggest their roles in urothelial cancer metabolism.
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Affiliation(s)
- Jung-Woo Choi
- Department of Pathology, Korea University Ansan Hospital, Ansan, Republic of Korea
| | - Younghye Kim
- Department of Pathology, Korea University Ansan Hospital, Ansan, Republic of Korea
| | - Ju-Han Lee
- Department of Pathology, Korea University Ansan Hospital, Ansan, Republic of Korea
| | - Young-Sik Kim
- Department of Pathology, Korea University Ansan Hospital, Ansan, Republic of Korea.
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160
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Draoui N, Schicke O, Seront E, Bouzin C, Sonveaux P, Riant O, Feron O. Antitumor activity of 7-aminocarboxycoumarin derivatives, a new class of potent inhibitors of lactate influx but not efflux. Mol Cancer Ther 2014; 13:1410-8. [PMID: 24672058 DOI: 10.1158/1535-7163.mct-13-0653] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
High lactate concentration in tumors is associated with bad prognosis. Lactate is released by glycolytic cells in tumors and recaptured by oxidative cancer cells to feed the tricarboxylic acid (TCA) cycle after conversion into pyruvate. Monocarboxylate transporters (MCT) mediate these fluxes of proton-linked lactate and represent attractive targets to interrupt lactate shuttle and to inhibit tumor growth. Here, we investigated the properties of 7-aminocarboxycoumarins (7ACC) developed to selectively interfere with lactate fluxes in the lactate-rich tumor microenvironment. The pharmacologic properties of two compounds of this family, including their effects on lactate influx and efflux and antitumor activity, were investigated using human cancer cell lines and mouse xenograft models. Contrary to the reference MCT1 inhibitor AR-C155858, 7ACC unexpectedly inhibited lactate influx but not efflux in tumor cells expressing MCT1 and MCT4 transporters. 7ACC delayed the growth of cervix SiHa tumors, colorectal HCT116 tumors, and orthoptopic MCF-7 breast tumors. MCT target engagement was confirmed by the lack of activity of 7ACC on bladder UM-UC-3 carcinoma that does not express functional MCT. 7ACC also inhibited SiHa tumor relapse after treatment with cisplatin. Finally, we found that contrary to AR-C155858, 7ACC did not prevent the cell entry of the substrate-mimetic drug 3-bromopyruvate (3BP) through MCT1, and contributed to the inhibition of tumor relapse after 3BP treatment. In conclusion, our results indicate that 7ACC selectively affects a single part of the MCT symporter translocation cycle, leading to strict inhibition of lactate influx. This singular activity is associated with antitumor effects less prone to resistance and side effects.
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Affiliation(s)
- Nihed Draoui
- Authors' Affiliations: Pole of Pharmacology and Therapeutics (FATH), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, Brussels; and Molecules, Solids and Reactivity (MOST), Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain, Louvain-la-Neuve, BelgiumAuthors' Affiliations: Pole of Pharmacology and Therapeutics (FATH), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, Brussels; and Molecules, Solids and Reactivity (MOST), Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Olivier Schicke
- Authors' Affiliations: Pole of Pharmacology and Therapeutics (FATH), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, Brussels; and Molecules, Solids and Reactivity (MOST), Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Emmanuel Seront
- Authors' Affiliations: Pole of Pharmacology and Therapeutics (FATH), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, Brussels; and Molecules, Solids and Reactivity (MOST), Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Caroline Bouzin
- Authors' Affiliations: Pole of Pharmacology and Therapeutics (FATH), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, Brussels; and Molecules, Solids and Reactivity (MOST), Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Pierre Sonveaux
- Authors' Affiliations: Pole of Pharmacology and Therapeutics (FATH), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, Brussels; and Molecules, Solids and Reactivity (MOST), Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Olivier Riant
- Authors' Affiliations: Pole of Pharmacology and Therapeutics (FATH), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, Brussels; and Molecules, Solids and Reactivity (MOST), Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Olivier Feron
- Authors' Affiliations: Pole of Pharmacology and Therapeutics (FATH), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, Brussels; and Molecules, Solids and Reactivity (MOST), Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain, Louvain-la-Neuve, Belgium
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161
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PCK2 activation mediates an adaptive response to glucose depletion in lung cancer. Oncogene 2014; 34:1044-50. [PMID: 24632615 DOI: 10.1038/onc.2014.47] [Citation(s) in RCA: 129] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 11/30/2013] [Accepted: 01/06/2014] [Indexed: 12/13/2022]
Abstract
Cancer cells are reprogrammed to utilize glycolysis at high rates, which provides metabolic precursors for cell growth. Consequently, glucose levels may decrease substantially in underperfused tumor areas. Gluconeogenesis results in the generation of glucose from smaller carbon substrates such as lactate and amino acids. The key gluconeogenic enzyme, phosphoenolpyruvate carboxykinase (PEPCK), has been shown to provide metabolites for cell growth. Still, the role of gluconeogenesis in cancer is unknown. Here we show that the mitochondrial isoform of PEPCK (PCK2) is expressed and active in three lung cancer cell lines and in non-small cell lung cancer samples. PCK2 expression and activity were enhanced under low-glucose conditions. PEPCK activity was elevated threefold in lung cancer samples over normal lungs. To track the conversion of metabolites along the gluconeogenesis pathway, lung cancer cell lines were incubated with (13)C₃-lactate and label enrichment in the phosphoenolpyruvate (PEP) pool was measured. Under low glucose, all three carbons from (13)C₃-lactate appeared in the PEP pool, further supporting a conversion of lactate to pyruvate, via pyruvate carboxylase to oxaloacetate, and via PCK2 to phosphoenolpyruvate. PCK2 small interfering RNA and the pharmacological PEPCK inhibitor 3-mercaptopicolinate significantly enhanced glucose depletion-induced apoptosis in A549 and H23 cells, but not in H1299 cells. The growth of H23 multicellular spheroids was significantly reduced by 3-mercaptopicolinate. The results of this study suggest that lung cancer cells may utilize at least some steps of gluconeogenesis to overcome the detrimental metabolic situation during glucose deprivation and that in human lung cancers this pathway is activated in vivo.
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162
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Neurogenesis and vascularization of the damaged brain using a lactate-releasing biomimetic scaffold. Biomaterials 2014; 35:4769-81. [PMID: 24636215 DOI: 10.1016/j.biomaterials.2014.02.051] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 02/22/2014] [Indexed: 12/23/2022]
Abstract
Regenerative medicine strategies to promote recovery following traumatic brain injuries are currently focused on the use of biomaterials as delivery systems for cells or bioactive molecules. This study shows that cell-free biomimetic scaffolds consisting of radially aligned electrospun poly-l/dl lactic acid (PLA70/30) nanofibers release L-lactate and reproduce the 3D organization and supportive function of radial glia embryonic neural stem cells. The topology of PLA nanofibers supports neuronal migration while L-lactate released during PLA degradation acts as an alternative fuel for neurons and is required for progenitor maintenance. Radial scaffolds implanted into cavities made in the postnatal mouse brain fostered complete implant vascularization, sustained neurogenesis, and allowed the long-term survival and integration of the newly generated neurons. Our results suggest that the endogenous central nervous system is capable of regeneration through the in vivo dedifferentiation induced by biophysical and metabolic cues, with no need for exogenous cells, growth factors, or genetic manipulation.
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163
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Chaitanya GV, Minagar A, Alexander JS. Neuronal and astrocytic interactions modulate brain endothelial properties during metabolic stresses of in vitro cerebral ischemia. Cell Commun Signal 2014; 12:7. [PMID: 24438487 PMCID: PMC3927849 DOI: 10.1186/1478-811x-12-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 11/25/2013] [Indexed: 01/25/2023] Open
Abstract
Neurovascular and gliovascular interactions significantly affect endothelial phenotype. Physiologically, brain endothelium attains several of its properties by its intimate association with neurons and astrocytes. However, during cerebrovascular pathologies such as cerebral ischemia, the uncoupling of neurovascular and gliovascular units can result in several phenotypical changes in brain endothelium. The role of neurovascular and gliovascular uncoupling in modulating brain endothelial properties during cerebral ischemia is not clear. Specifically, the roles of metabolic stresses involved in cerebral ischemia, including aglycemia, hypoxia and combined aglycemia and hypoxia (oxygen glucose deprivation and re-oxygenation, OGDR) in modulating neurovascular and gliovascular interactions are not known. The complex intimate interactions in neurovascular and gliovascular units are highly difficult to recapitulate in vitro. However, in the present study, we used a 3D co-culture model of brain endothelium with neurons and astrocytes in vitro reflecting an intimate neurovascular and gliovascular interactions in vivo. While the cellular signaling interactions in neurovascular and gliovascular units in vivo are much more complex than the 3D co-culture models in vitro, we were still able to observe several important phenotypical changes in brain endothelial properties by metabolically stressed neurons and astrocytes including changes in barrier, lymphocyte adhesive properties, endothelial cell adhesion molecule expression and in vitro angiogenic potential.
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Affiliation(s)
| | | | - Jonathan S Alexander
- Department of Molecular and Cellular Physiology, Louisiana State University Health-Shreveport, Louisiana 71103, USA.
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164
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Mullner E, Brath H, Nersesyan A, Nitz M, Petschnig A, Wallner M, Knasmuller S, Wagner KH. Nuclear anomalies in exfoliated buccal cells in healthy and diabetic individuals and the impact of a dietary intervention. Mutagenesis 2013; 29:1-6. [DOI: 10.1093/mutage/get056] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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165
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Eelen G, Cruys B, Welti J, De Bock K, Carmeliet P. Control of vessel sprouting by genetic and metabolic determinants. Trends Endocrinol Metab 2013; 24:589-96. [PMID: 24075830 DOI: 10.1016/j.tem.2013.08.006] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 08/26/2013] [Accepted: 08/28/2013] [Indexed: 01/28/2023]
Abstract
Vessel sprouting by endothelial cells (ECs) during angiogenesis relies on a navigating tip cell and on proliferating stalk cells that elongate the shaft. To date, only genetic signals have been shown to regulate vessel sprouting. However, emerging evidence indicates that the angiogenic switch also requires a metabolic switch. Indeed, angiogenic signals not only induce a change in EC metabolism but this metabolic adaptation also co-determines vessel sprouting. The glycolytic activator PFKFB3 regulates stalk cell proliferation and renders ECs more competitive to reach the tip. We discuss the emerging link between angiogenesis and EC metabolism during the various stages of vessel sprouting, focusing only on genetic signals for which an effect on EC metabolism has been documented.
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Affiliation(s)
- Guy Eelen
- Laboratory of Angiogenesis and Neurovascular Link, Vesalius Research Center, Vlaams Instituut voor Biotechnologie (VIB), Department of Oncology, Katholieke Universiteit Leuven (KU Leuven), Herestraat 49, 3000 Leuven, Belgium
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166
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Venkateswaran A, Sekhar KR, Levic DS, Melville DB, Clark TA, Rybski WM, Walsh AJ, Skala MC, Crooks PA, Knapik EW, Freeman ML. The NADH oxidase ENOX1, a critical mediator of endothelial cell radiosensitization, is crucial for vascular development. Cancer Res 2013; 74:38-43. [PMID: 24247717 DOI: 10.1158/0008-5472.can-13-1981] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
ENOX1 is a highly conserved NADH oxidase that helps to regulate intracellular nicotinamide adenine dinucleotide levels in many cell types, including endothelial cells. Pharmacologic and RNA interference (RNAi)-mediated suppression of ENOX1 impairs surrogate markers of tumor angiogenesis/vasculogenesis, providing support for the concept that ENOX1 represents an antiangiogenic druggable target. However, direct genetic evidence that demonstrates a role for ENOX1 in vascular development is lacking. In this study, we exploited a zebrafish embryonic model of development to address this question. Whole-mount in situ hybridization coupled with immunofluorescence performed on zebrafish embryos demonstrate that enox1 message and translated protein are expressed in most tissues, and its expression is enriched in blood vessels and heart. Morpholino-mediated suppression of Enox1 in Tg(fli1-eGFP) and Tg(flk1-eGFP) zebrafish embryos significantly impairs the development of vasculature and blood circulation. Using in vivo multiphoton microscopy, we show that morpholino-mediated knockdown of enox1 increases NADH levels, consistent with loss of enzyme. VJ115 is a small-molecule inhibitor of Enox1's oxidase activity shown to increase intracellular NADH in endothelial cells; we used VJ115 to determine if the oxidase activity was crucial for vascular development. We found that VJ115 suppressed vasculogenesis in Tg(fli1-eGFP) embryos and impaired circulation. Previously, it was shown that suppression of ENOX1 radiosensitizes proliferating tumor vasculature, a consequence of enhanced endothelial cell apoptosis. Thus, our current findings, coupled with previous research, support the hypothesis that ENOX1 represents a potential cancer therapy target, one that combines molecular targeting with cytotoxic sensitization.
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Affiliation(s)
- Amudhan Venkateswaran
- Authors' Affiliations: Departments of Radiation Oncology and Medicine and Cell & Developmental Biology; Genomic Sciences Resources, Vanderbilt University Medical Center; Biomedical Engineering, Vanderbilt School of Engineering, Nashville, Tennessee; School of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, Arkansas; and Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California
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167
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Abstract
Endothelial cells (ECs) are quiescent for years but can plastically switch to angiogenesis. Vascular sprouting relies on the coordinated activity of migrating tip cells at the forefront and proliferating stalk cells that elongate the sprout. Past studies have identified genetic signals that control vascular branching. Prominent are VEGF, activating tip cells, and Notch, which stimulates stalk cells. After the branch is formed and perfused, ECs become quiescent phalanx cells. Now, emerging evidence has accumulated indicating that ECs not only adapt their metabolism when switching from quiescence to sprouting but also that metabolism regulates vascular sprouting in parallel to the control by genetic signals.
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Affiliation(s)
- Katrien De Bock
- Department of Oncology, University of Leuven, Laboratory of Angiogenesis and Neurovascular Link, Vesalius Research Center, Leuven 3000, Belgium; VIB, Laboratory of Angiogenesis and Neurovascular Link, Vesalius Research Center, Leuven 3000, Belgium
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168
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Affiliation(s)
- E H Mathews
- Center for Research and Continued Engineering Development, North-West University (Pretoria campus), Pretoria, South Africa; Consultants to TEMM International (Pty) Ltd., Pretoria, South Africa
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169
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Choi SYC, Collins CC, Gout PW, Wang Y. Cancer-generated lactic acid: a regulatory, immunosuppressive metabolite? J Pathol 2013; 230:350-5. [PMID: 23729358 PMCID: PMC3757307 DOI: 10.1002/path.4218] [Citation(s) in RCA: 214] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 05/26/2013] [Accepted: 05/28/2013] [Indexed: 12/18/2022]
Abstract
The common preference of cancers for lactic acid-generating metabolic energy pathways has led to proposals that their reprogrammed metabolism confers growth advantages such as decreased susceptibility to hypoxic stress. Recent observations, however, suggest that it generates a novel way for cancer survival. There is increasing evidence that cancers can escape immune destruction by suppressing the anti-cancer immune response through maintaining a relatively low pH in their micro-environment. Tumours achieve this by regulating lactic acid secretion via modification of glucose/glutamine metabolisms. We propose that the maintenance by cancers of a relatively low pH in their micro-environment, via regulation of their lactic acid secretion through selective modification of their energy metabolism, is another major mechanism by which cancers can suppress the anti-cancer immune response. Cancer-generated lactic acid could thus be viewed as a critical, immunosuppressive metabolite in the tumour micro-environment rather than a ‘waste product’. This paradigm shift can have major impact on therapeutic strategy development. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Affiliation(s)
- Stephen Yiu Chuen Choi
- Department of Experimental Therapeutics, BC Cancer Agency, Vancouver, British Columbia, Canada
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170
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Grandjean M, Dieu M, Raes M, Feron O. A new method combining sequential immunoaffinity depletion and differential in gel electrophoresis to identify autoantibodies as cancer biomarkers. J Immunol Methods 2013; 396:23-32. [PMID: 23916966 DOI: 10.1016/j.jim.2013.07.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2013] [Revised: 07/25/2013] [Accepted: 07/26/2013] [Indexed: 12/17/2022]
Abstract
Easily measurable biomarkers are urgently required to detect early stages of cancer progression. Autoantibodies (aAbs), as a component of the humoral immune response against tumor cells, have such potential of diagnostic markers since they are circulating and stable proteins, produced rapidly and easily amenable to in vitro dosage. The identification of aAbs is based on the characterization of tumor-associated antigens (TAA) against which they are directed. Here, we propose a new method for an unbiased identification of TAA and thereby of aAbs as cancer biomarkers. This method that we called sequential immunoaffinity depletion-differential in gel electrophoresis (SID-DIGE) is based on the immunodepletion of tumor cell lysates with IgG from control and tumor-bearing mice and direct matching of the flow throughs of these immunoaffinity separations on the same 2D format. This strategy reduces the complexity of the samples to be analyzed and maximizes the interest of assessing hundreds of proteins simultaneously. SID-DIGE has also the potential, contrary to existing serological proteome analysis (SERPA) techniques, to detect immunogenic proteins with conformational epitopes, including those resulting from post-translational modifications. Using a model of human colorectal tumors in mice for the proof of principle, we showed that SID-DIGE outperforms the conventional SERPA technique, with the identification of 7 common TAA (validating our approach) and 18 additional aAbs proving the potential of this new method. In particular, the identification of aAbs directed against key enzymes supporting glycolysis gives credential to the role of hypoxia as a major determinant of the tumor proteome and thus as a source of immunogenicity. Overall, the developed methodology allowed efficient screening of sera for the identification of aAbs as potential biomarkers.
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Affiliation(s)
- Marie Grandjean
- UCLouvain, Institut de Recherche Expérimentale et Clinique (IREC), Pole of Pharmacology and Therapeutics (FATH), Brussels, Belgium
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171
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Casazza A, Di Conza G, Wenes M, Finisguerra V, Deschoemaeker S, Mazzone M. Tumor stroma: a complexity dictated by the hypoxic tumor microenvironment. Oncogene 2013; 33:1743-54. [PMID: 23604130 DOI: 10.1038/onc.2013.121] [Citation(s) in RCA: 179] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 02/15/2013] [Accepted: 02/21/2013] [Indexed: 12/21/2022]
Abstract
A lot of effort has been done to study how cancer cells react to low-oxygen tension, a condition known as hypoxia. Indeed, abnormal and dysfunctional blood vessels in the tumor are incapable to restore oxygenation, therefore perpetuating hypoxia, which, in turn, will fuel tumor progression, metastasis and resistance to antitumor therapies. Nevertheless, how stromal components including blood and lymphatic endothelial cells, pericytes and fibroblasts, as well as hematopoietic cells, respond to low-oxygen tension in comparison with their normoxic counterparts has been a matter of investigation in the last few years only and, to date, this field of research remains poorly understood. In general, opposing phenotypes can arise from the same stromal component when embedded in different tumor microenvironments, and, vice versa, different stromal components can have opposite reaction to the same tumor microenvironment. In this article, we will discuss the emerging link between tumor stroma and hypoxia, and how this complexity is translated at the molecular level.
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Affiliation(s)
- A Casazza
- 1] Laboratory of Molecular Oncology and Angiogenesis, Vesalius Research Center, VIB, Leuven, Belgium, Belgium [2] Laboratory of Molecular Oncology and Angiogenesis, Vesalius Research Center, K.U.Leuven, Leuven, Belgium, Belgium
| | - G Di Conza
- 1] Laboratory of Molecular Oncology and Angiogenesis, Vesalius Research Center, VIB, Leuven, Belgium, Belgium [2] Laboratory of Molecular Oncology and Angiogenesis, Vesalius Research Center, K.U.Leuven, Leuven, Belgium, Belgium
| | - M Wenes
- 1] Laboratory of Molecular Oncology and Angiogenesis, Vesalius Research Center, VIB, Leuven, Belgium, Belgium [2] Laboratory of Molecular Oncology and Angiogenesis, Vesalius Research Center, K.U.Leuven, Leuven, Belgium, Belgium
| | - V Finisguerra
- 1] Laboratory of Molecular Oncology and Angiogenesis, Vesalius Research Center, VIB, Leuven, Belgium, Belgium [2] Laboratory of Molecular Oncology and Angiogenesis, Vesalius Research Center, K.U.Leuven, Leuven, Belgium, Belgium
| | - S Deschoemaeker
- 1] Laboratory of Molecular Oncology and Angiogenesis, Vesalius Research Center, VIB, Leuven, Belgium, Belgium [2] Laboratory of Molecular Oncology and Angiogenesis, Vesalius Research Center, K.U.Leuven, Leuven, Belgium, Belgium
| | - M Mazzone
- 1] Laboratory of Molecular Oncology and Angiogenesis, Vesalius Research Center, VIB, Leuven, Belgium, Belgium [2] Laboratory of Molecular Oncology and Angiogenesis, Vesalius Research Center, K.U.Leuven, Leuven, Belgium, Belgium
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172
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Affiliation(s)
- L Claesson-Welsh
- Uppsala University, Dept. Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala, Sweden.
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173
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Desbats MA, Giacomini I, Prayer-Galetti T, Montopoli M. Iron granules in plasma cells. J Clin Pathol 1982; 10:281. [PMID: 32211323 PMCID: PMC7068907 DOI: 10.3389/fonc.2020.00281] [Citation(s) in RCA: 90] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 02/18/2020] [Indexed: 01/16/2023]
Abstract
Resistance of cancer cells to chemotherapy is the first cause of cancer-associated death. Thus, new strategies to deal with the evasion of drug response and to improve clinical outcomes are needed. Genetic and epigenetic mechanisms associated with uncontrolled cell growth result in metabolism reprogramming. Cancer cells enhance anabolic pathways and acquire the ability to use different carbon sources besides glucose. An oxygen and nutrient-poor tumor microenvironment determines metabolic interactions among normal cells, cancer cells and the immune system giving rise to metabolically heterogeneous tumors which will partially respond to metabolic therapy. Here we go into the best-known cancer metabolic profiles and discuss several studies that reported tumors sensitization to chemotherapy by modulating metabolic pathways. Uncovering metabolic dependencies across different chemotherapy treatments could help to rationalize the use of metabolic modulators to overcome therapy resistance.
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Affiliation(s)
- Maria Andrea Desbats
- Department of Medicine, University of Padova, Padova, Italy
- Veneto Institute of Molecular Medicine, Padova, Italy
| | - Isabella Giacomini
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
| | | | - Monica Montopoli
- Veneto Institute of Molecular Medicine, Padova, Italy
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
- *Correspondence: Monica Montopoli
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