scholarly journals Metabolic Alterations in Cancer and Their Potential as Therapeutic Targets

Author(s):  
Jamie D. Weyandt ◽  
Craig B. Thompson ◽  
Amato J. Giaccia ◽  
W. Kimryn Rathmell

Otto Warburg’s discovery in the 1920s that tumor cells took up more glucose and produced more lactate than normal cells provided the first clues that cancer cells reprogrammed their metabolism. For many years, however, it was unclear as to whether these metabolic alterations were a consequence of tumor growth or an adaptation that provided a survival advantage to these cells. In more recent years, interest in the metabolic differences in cancer cells has surged, as tumor proliferation and survival have been shown to be dependent upon these metabolic changes. In this educational review, we discuss some of the mechanisms that tumor cells use for reprogramming their metabolism to provide the energy and nutrients that they need for quick or sustained proliferation and discuss the potential for therapeutic targeting of these pathways to improve patient outcomes.

Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 568 ◽  
Author(s):  
Peter Kaiser

Tumorigenesis is accompanied by the reprogramming of cellular metabolism. The shift from oxidative phosphorylation to predominantly glycolytic pathways to support rapid growth is well known and is often referred to as the Warburg effect. However, other metabolic changes and acquired needs that distinguish cancer cells from normal cells have also been discovered. The dependence of cancer cells on exogenous methionine is one of them and is known as methionine dependence or the Hoffman effect. This phenomenon describes the inability of cancer cells to proliferate when methionine is replaced with its metabolic precursor, homocysteine, while proliferation of non-tumor cells is unaffected by these conditions. Surprisingly, cancer cells can readily synthesize methionine from homocysteine, so their dependency on exogenous methionine reflects a general need for altered metabolic flux through pathways linked to methionine. In this review, an overview of the field will be provided and recent discoveries will be discussed.


2015 ◽  
Vol 89 (15) ◽  
pp. 7944-7954 ◽  
Author(s):  
Marlena M. Westcott ◽  
Jingfang Liu ◽  
Karishma Rajani ◽  
Ralph D'Agostino ◽  
Douglas S. Lyles ◽  
...  

ABSTRACTOncolytic viruses (OV) preferentially kill cancer cells due in part to defects in their antiviral responses upon exposure to type I interferons (IFNs). However, IFN responsiveness of some tumor cells confers resistance to OV treatment. The human type I IFNs include one IFN-β and multiple IFN-α subtypes that share the same receptor but are capable of differentially inducing biological responses. The role of individual IFN subtypes in promoting tumor cell resistance to OV is addressed here. Two human IFNs which have been produced for clinical use, IFN-α2a and IFN-β, were compared for activity in protecting human head and neck squamous cell carcinoma (HNSCC) lines from oncolysis by vesicular stomatitis virus (VSV). Susceptibility of HNSCC lines to killing by VSV varied. VSV infection induced increased production of IFN-β in resistant HNSCC cells. When added exogenously, IFN-β was significantly more effective at protecting HNSCC cells from VSV oncolysis than was IFN-α2a. In contrast, normal keratinocytes and endothelial cells were protected equivalently by both IFN subtypes. Differential responsiveness of tumor cells to IFN-α and -β was further supported by the finding that autocrine IFN-β but not IFN-α promoted survival of HNSCC cells during persistent VSV infection. Therefore, IFN-α and -β differentially affect VSV oncolysis, justifying the evaluation and comparison of IFN subtypes for use in combination with VSV therapy. Pairing VSV with IFN-α2a may enhance selectivity of oncolytic VSV therapy for HNSCC by inhibiting VSV replication in normal cells without a corresponding inhibition in cancer cells.IMPORTANCEThere has been a great deal of progress in the development of oncolytic viruses. However, a major problem is that individual cancers vary in their sensitivity to oncolytic viruses. In many cases this is due to differences in their production and response to interferons (IFNs). The experiments described here compared the responses of head and neck squamous cell carcinoma cell lines to two IFN subtypes, IFN-α2a and IFN-β, in protection from oncolytic vesicular stomatitis virus. We found that IFN-α2a was significantly less protective for cancer cells than was IFN-β, whereas normal cells were equivalently protected by both IFNs. These results suggest that from a therapeutic standpoint, selectivity for cancer versus normal cells may be enhanced by pairing VSV with IFN-α2a.


2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e22113-e22113
Author(s):  
M. N. Jha ◽  
J. S. Bedford ◽  
S. Jha ◽  
K. Prasad

e22113 Background: It is estimated that low dose radiation can increase the risk of cancer as well as mutations. However, the interaction of low dose radiation with caffeine has not been adequately investigated. We investigated the effects of caffeine on low dose- gamma-radiation-induced chromosomal damage in human T leukemia cells (Jurket T-cells) and two normal human fibroblast cell lines (AG1522 and GM 2149). Method: Jurkat cells were maintained in RPMI 1640 medium and fibroblast in alpha-minimal essential medium (MEM) All cells were incubated at 37o C in a humidified atmosphere of 5% CO2 in air. Cells from the exponential phase were treated with 1 mg/ml caffeine ( control cells received same amount of solvent) and irradiated with low doses (3, 5, 10, 20 and 40 cGy,), using a 137 Cs-gamma radiation source. Colcemid at a concentration of 0.1 μg/ml was added to every flask. Cells were fixed in methanol: acetic acid solution and stained with Giemsa. 100 irradiated and un-irradiated metaphase- like cells were scored for chromatid-type aberrations. Results: Low dose gamma-radiation increased the levels of chromatid breaks(dose dependent) in both normal and cancer cells; however, cancer cells appeared to be more sensitive than the normal cells. Caffeine treatment markedly increased chromatid aberrations in Jurkat T-cells at all radiation doses but not in normal cells. Previously, we reported that caffeine eliminates gamma-ray-induced G2 delay in other human tumor cells but not normal cells (Jha, et.al., Radiat. Res. 157, 26–31, 2002). Conclusions: The mechanisms that may underlie this differential effect of caffeine in cancer and normal cells are unknown, but if one result of a G2 delay is to allow more time for chromosome breakage rejoining processes to occur, then elimination of this delay by caffeine in tumor cells but not normal cells might account for the difference. To the extent these observations are generally true for tumor vs normal cells, the differential sensitization could have an impact in improving the efficacy of radiation therapy. No significant financial relationships to disclose.


2020 ◽  
Vol 2020 ◽  
pp. 1-30
Author(s):  
Rumiana Bakalova ◽  
Severina Semkova ◽  
Donika Ivanova ◽  
Zhivko Zhelev ◽  
Thomas Miller ◽  
...  

Redox-active substances and their combinations, such as of quinone/ascorbate and in particular menadione/ascorbate (M/A; also named Apatone®), attract attention with their unusual ability to kill cancer cells without affecting the viability of normal cells as well as with the synergistic anticancer effect of both molecules. So far, the primary mechanism of M/A-mediated anticancer effects has not been linked to the mitochondria. The aim of our study was to clarify whether this “combination drug” affects mitochondrial functionality specifically in cancer cells. Studies were conducted on cancer cells (Jurkat, Colon26, and MCF7) and normal cells (normal lymphocytes, FHC, and MCF10A), treated with different concentrations of menadione, ascorbate, and/or their combination (2/200, 3/300, 5/500, 10/1000, and 20/2000 μM/μM of M/A). M/A exhibited highly specific and synergistic suppression on cancer cell growth but without adversely affecting the viability of normal cells at pharmacologically attainable concentrations. In M/A-treated cancer cells, the cytostatic/cytotoxic effect is accompanied by (i) extremely high production of mitochondrial superoxide (up to 15-fold over the control level), (ii) a significant decrease of mitochondrial membrane potential, (iii) a decrease of the steady-state levels of ATP, succinate, NADH, and NAD+, and (iv) a decreased expression of programed cell death ligand 1 (PD-L1)—one of the major immune checkpoints. These effects were dose dependent. The inhibition of NQO1 by dicoumarol increased mitochondrial superoxide and sensitized cancer cells to M/A. In normal cells, M/A induced relatively low and dose-independent increase of mitochondrial superoxide and mild oxidative stress, which seems to be well tolerated. These data suggest that all anticancer effects of M/A result from a specific mechanism, tightly connected to the mitochondria of cancer cells. At low/tolerable doses of M/A (1/100-3/300 μM/μM) attainable in cancer by oral and parenteral administration, M/A sensitized cancer cells to conventional anticancer drugs, exhibiting synergistic or additive cytotoxicity accompanied by impressive induction of apoptosis. Combinations of M/A with 13 anticancer drugs were investigated (ABT-737, barasertib, bleomycin, BEZ-235, bortezomib, cisplatin, everolimus, lomustine, lonafarnib, MG-132, MLN-2238, palbociclib, and PI-103). Low/tolerable doses of M/A did not induce irreversible cytotoxicity in cancer cells but did cause irreversible metabolic changes, including: (i) a decrease of succinate and NADH, (ii) depolarization of the mitochondrial membrane, and (iii) overproduction of superoxide in the mitochondria of cancer cells only. In addition, M/A suppressed tumor growth in vivo after oral administration in mice with melanoma and the drug downregulated PD-L1 in melanoma cells. Experimental data suggest a great potential for beneficial anticancer effects of M/A through increasing the sensitivity of cancer cells to conventional anticancer therapy, as well as to the immune system, while sparing normal cells. We hypothesize that M/A-mediated anticancer effects are triggered by redox cycling of both substances, specifically within dysfunctional mitochondria. M/A may also have a beneficial effect on the immune system, making cancer cells “visible” and more vulnerable to the native immune response.


2015 ◽  
Vol 88 (3) ◽  
pp. 272-277 ◽  
Author(s):  
Eva Fischer-Fodor ◽  
Natalia Miklasova ◽  
Ioana Berindan-Neagoe ◽  
Bhaskar Saha

Chronic inflammation is associated with the metastasis of tumor cells evolving from a benign tumor to disseminating cancer.  Such a metastatic progression is fostered by the angiogenesis propelled by various mediators interacting at the site of tumor growth. Angiogenesis causes two major changes that are assisted by altered glycosylation and neo-antigen presentation by the cancer cells. The angiogenesis-promoted pathological changes include enhanced inflammation and degradation of tissue matrices releasing tumor cells from the site of its origin. The degraded tumor cells release the neo-antigens resulting from altered glycosylation. Presentation of neo-antigens to T cells escalates metastasis and inflammation. Inflammasome activation and inflammation in several infections are regulated by iron. Based on the discrete reports, we propose a link between iron, inflammation, angiogenesis and tumor growth. Knowing the link better may help us formulate a novel strategy for cancer immunotherapy.


2002 ◽  
Vol 282 (5) ◽  
pp. C947-C970 ◽  
Author(s):  
Michael Papetti ◽  
Ira M. Herman

Often those diseases most evasive to therapeutic intervention usurp the human body's own cellular machinery or deregulate normal physiological processes for propagation. Tumor-induced angiogenesis is a pathological condition that results from aberrant deployment of normal angiogenesis, an essential process in which the vascular tree is remodeled by the growth of new capillaries from preexisting vessels. Normal angiogenesis ensures that developing or healing tissues receive an adequate supply of nutrients. Within the confines of a tumor, the availability of nutrients is limited by competition among actively proliferating cells, and diffusion of metabolites is impeded by high interstitial pressure (Jain RK. Cancer Res 47: 3039–3051, 1987). As a result, tumor cells induce the formation of a new blood supply from the preexisting vasculature, and this affords tumor cells the ability to survive and propagate in a hostile environment. Because both normal and tumor-induced neovascularization fulfill the essential role of satisfying the metabolic demands of a tissue, the mechanisms by which cancer cells stimulate pathological neovascularization mimic those utilized by normal cells to foster physiological angiogenesis. This review investigates mechanisms of tumor-induced angiogenesis. The strategies used by cancer cells to develop their own blood supply are discussed in relation to those employed by normal cells during physiological angiogenesis. With an understanding of blood vessel growth in both normal and abnormal settings, we are better suited to design effective therapeutics for cancer.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3321-3321
Author(s):  
Rong Li ◽  
Meiping Ren ◽  
Ni Chen ◽  
Mao Luo ◽  
Jianbo Wu

Abstract Abstract 3321 Platelets play a fundamental role in maintaining hemostasis and have been shown to participate in hemorrhagic metastasis. However, the role of platelets in the tumor growth, angiogenesis, and metastasis initiation remains undefined. The B16/F10 melanoma cancer cells model of metastasis and the Lewis lung carcinoma (LLC) spontaneous pulmonary metastasis model were used for this purpose. Using induction of thrombocytopenia, primary tumor growth was monitored and every 3 days anti-GPIbα or rat IgG injections were initiated when tumor reached ∼500mm3and continued until tumor reached to 3 weeks. We showed that platelet depletion had no change in tumor growth but reduced metastasis. Platelet depletion significantly increased pericyte coverage and reduced vascular density compared with control mice. We evaluated the ratio of fluorescence intensities within the plasma and tumor following injection of mice with FITC-dextran. We found that the FITC-dextran was similarly deposited into the tumor tissue in either platelet-depleted or control mice, indicating that tumor vessel perfusion did not differ in either platelet-depleted or control mice. To further gain insight into the molecular mechanisms associated with reduced metastasis resulting from platelet depletion, we assessed hypoxia levels by examining pimonidazole adduct formation in the tumors of platelet-depleted and control mice and found decreased hypoxic levels in the platelet-depleted tumors. In addition, expression of the hypoxia-inducible transcription factor HIF-1α was also significantly reduced in the tumors of platelet-depleted mice. Tumor hypoxia is strongly associated with deposition of hemoglobin. We measured the intratumor hemoglobin content, reflecting the level of erythrocytes extravasation. The hemoglobin content in the tumors of mice with platelet-depletion was significantly higher than that of control mice (172.11 ± 20.2 g/L/g Vs. 110.28 ± 12.4 g/L/g, p<0.05) Based on the known induction effects of hypoxia and cancer invasiveness on the expression and activation of the proinvasive tyrosine kinase receptor Met, we analyzed total protein and tyrosine phosphorylation levels of Met in both platelet-depleted and control mice. Western blotting analysis revealed that platelet-depletion caused a significantly decrease of both total Met and phosph-Met in tumors when compared to tumors from control mice. To evaluate intratumoral growth factor level, microdialysis was performed after 3 weeks and there was a significant decrease of extracellular VEGF and TNF-β in platelet depletion mice compared with control mice. Recent studies demonstrated that abundant platelets were detected in the tumor microenvironment apart from the vasculature. Based on the finding platelets in contact with tumor cells outside the bloodstream, we examined the functional effects of co-implantation of B16/F10 tumor cells with platelets on tumor progression and metastasis. B16/F10 melanoma cancer cells were implanted into back of wild type mice. During a 3-weeks growth, co-implantation of B16/F10 with platelets not only led to promoted tumor volume (3968 ± 296 mm3Vs. 2956 ± 180 mm3, p<0.05) and weight (5.529 ± 0.35 g Vs. 3.943 ± 0.738 g, p<0.05 ) compared with B16/F10 alone implantation, but also led to an increase in metastasis. Furthermore, in vitro co-culture of B16/F10 cancer cells with platelets showed a significant increase in B16/F10 cancer cells invasion compared with B16/F10 cancer cells alone. In conclusion, our findings demonstrate for the first time that platelets play a critical role in the initiation of tumor metastasis. Moreover, our findings suggest that platelets within the primary tumor microenvironment are likely involved in tumor progression and metastasis. Disclosures: No relevant conflicts of interest to declare.


Cells ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2486
Author(s):  
Ronit Vogt Sionov

Neutrophils are the most abundant immune cell in the circulation of human and act as gatekeepers to discard foreign elements that have entered the body. They are essential in initiating immune responses for eliminating invaders, such as microorganisms and alien particles, as well as to act as immune surveyors of cancer cells, especially during the initial stages of carcinogenesis and for eliminating single metastatic cells in the circulation and in the premetastatic organs. Since neutrophils can secrete a whole range of factors stored in their many granules as well as produce reactive oxygen and nitrogen species upon stimulation, neutrophils may directly or indirectly affect carcinogenesis in both the positive and negative directions. An intricate crosstalk between tumor cells, neutrophils, other immune cells and stromal cells in the microenvironment modulates neutrophil function resulting in both anti- and pro-tumor activities. Both the anti-tumor and pro-tumor activities require chemoattraction towards the tumor cells, neutrophil activation and ROS production. Divergence is seen in other neutrophil properties, including differential secretory repertoire and membrane receptor display. Many of the direct effects of neutrophils on tumor growth and metastases are dependent on tight neutrophil–tumor cell interactions. Among them, the neutrophil Mac-1 interaction with tumor ICAM-1 and the neutrophil L-selectin interaction with tumor-cell sialomucins were found to be involved in the neutrophil-mediated capturing of circulating tumor cells resulting in increased metastatic seeding. On the other hand, the anti-tumor function of neutrophils was found to rely on the interaction between tumor-surface-expressed receptor for advanced glycation end products (RAGE) and Cathepsin G expressed on the neutrophil surface. Intriguingly, these two molecules are also involved in the promotion of tumor growth and metastases. RAGE is upregulated during early inflammation-induced carcinogenesis and was found to be important for sustaining tumor growth and homing at metastatic sites. Cathepsin G was found to be essential for neutrophil-supported lung colonization of cancer cells. These data level up the complexity of the dual role of neutrophils in cancer.


Cancers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 322
Author(s):  
Roberto Corchado-Cobos ◽  
Natalia García-Sancha ◽  
Marina Mendiburu-Eliçabe ◽  
Aurora Gómez-Vecino ◽  
Alejandro Jiménez-Navas ◽  
...  

Metabolic changes that facilitate tumor growth are one of the hallmarks of cancer. The triggers of these metabolic changes are located in the tumor parenchymal cells, where oncogenic mutations induce an imperative need to proliferate and cause tumor initiation and progression. Cancer cells undergo significant metabolic reorganization during disease progression that is tailored to their energy demands and fluctuating environmental conditions. Oxidative stress plays an essential role as a trigger under such conditions. These metabolic changes are the consequence of the interaction between tumor cells and stromal myofibroblasts. The metabolic changes in tumor cells include protein anabolism and the synthesis of cell membranes and nucleic acids, which all facilitate cell proliferation. They are linked to catabolism and autophagy in stromal myofibroblasts, causing the release of nutrients for the cells of the tumor parenchyma. Metabolic changes lead to an interstitium deficient in nutrients, such as glucose and amino acids, and acidification by lactic acid. Together with hypoxia, they produce functional changes in other cells of the tumor stroma, such as many immune subpopulations and endothelial cells, which lead to tumor growth. Thus, immune cells favor tissue growth through changes in immunosuppression. This review considers some of the metabolic changes described in breast cancer.


2020 ◽  
Author(s):  
Katherine Wallis ◽  
Jordan T. Bird ◽  
Allen Gies ◽  
Sam G. Mackintosh ◽  
Alan J. Tackett ◽  
...  

ABSTRACTDietary methionine restriction is associated with a reduction in tumor growth in preclinical studies and an increase in lifespan in animal models. The mechanism by which methionine restriction inhibits tumor growth while sparing normal cells is incompletely understood, except for the observation that normal cells can utilize methionine or homocysteine interchangeably (methionine independence) while most cancer cells are strictly dependent on methionine availability. Here, we compared a typical methionine dependent and a rare methionine independent melanoma cell line. We found that replacing methionine with homocysteine generally induced hypomethylation in gene promoters. We isolated nuclear proteins and submitted it for tandem mass tag (TMT) proteomics. This analysis revealed that several proteins involved in the mitochondrial integrated stress response (ISR) were upregulated in response to the replacement of methionine to homocysteine in both cell lines, but to a much greater degree in the methionine dependent cell line. Consistent with the ISR signature, a proteomic analysis of a subcellular fraction enriched for mitochondrial content revealed a strong enrichment for proteins involved in oxidative phosphorylation. Analysis of cellular bioenergetics confirmed that homocysteine induces a decrease in ATP production from oxidative phosphorylation and glycolysis, but to a similar extent in methionine dependent and methionine independent cells. The mitochondrial integrated stress response shared a signature with ferroptosis. Methionine dependent cells displayed a strong ferroptotic signature, which was decreased by half in methionine independent cells. Consistent with ferroptosis, lipid peroxidation was significantly increased in methionine independent cells grown in homocysteine, and viability could be rescued partially but significantly with the inhibitor ferrostatin. Therefore, we propose that methionine stress induces ferroptotic cell death in methionine dependent cancer cells.


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