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Ovarian cancer (OC) adjusts energy metabolism in favor of its progression and dissemination. Because melatonin (Mel) has antitumor actions, we investigated its impact on energy metabolism and kinase signaling in OC cells (SKOV-3 and CAISMOV-24). Cells were divided into control and Mel-treated groups, in the presence or absence of the antagonist luzindole. There was a decrease in the levels of HIF-1α, G6PDH, GAPDH, PDH, and CS after Mel treatment even in the presence of luzindole in both OC cells. Mel treatment also reduced the activity of OC-related enzymes including PFK-1, G6PDH, LDH, CS, and GS whereas PDH activity was increased. Lactate and glutamine levels dropped after Mel treatment. Mel further promoted a reduction in the concentrations of CREB, JNK, NF-kB, p-38, ERK1/2, AKT, P70S6K, and STAT in both cell lines. Mel reverses Warburg-type metabolism and possibly reduces glutaminolysis, thereby attenuating various oncogenic molecules associated with OC progression and invasion.
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Metabolismo Energético , Melatonina , Neoplasias Ovarianas , Transdução de Sinais , Humanos , Feminino , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/tratamento farmacológico , Metabolismo Energético/efeitos dos fármacos , Melatonina/farmacologia , Linhagem Celular Tumoral , Transdução de Sinais/efeitos dos fármacos , Carcinogênese/efeitos dos fármacos , Carcinogênese/metabolismo , Carcinogênese/patologia , OncogenesRESUMO
BACKGROUND: Endometrial fibrosis, a significant characteristic of intrauterine adhesion (IUA), is caused by the excessive differentiation and activation of endometrial stromal cells (ESCs). Glutaminolysis is the metabolic process of glutamine (Gln), which has been implicated in multiple types of organ fibrosis. So far, little is known about whether glutaminolysis plays a role in endometrial fibrosis. METHODS: The activation model of ESCs was constructed by TGF-ß1, followed by RNA-sequencing analysis. Changes in glutaminase1 (GLS1) expression at RNA and protein levels in activated ESCs were verified experimentally. Human IUA samples were collected to verify GLS1 expression in endometrial fibrosis. GLS1 inhibitor and glutamine deprivation were applied to ESCs models to investigate the biological functions and mechanisms of glutaminolysis in ESCs activation. The IUA mice model was established to explore the effect of glutaminolysis inhibition on endometrial fibrosis. RESULTS: We found that GLS1 expression was significantly increased in activated ESCs models and fibrotic endometrium. Glutaminolysis inhibition by GLS1 inhibitor bis-2-(5-phenylacetamido-1,2,4-thiadiazol-2-yl) ethyl sulfide (BPTES or glutamine deprivation treatment suppressed the expression of two fibrotic markers, α-SMA and collagen I, as well as the mitochondrial function and mTORC1 signaling in ESCs. Furthermore, inhibition of the mTORC1 signaling pathway by rapamycin suppressed ESCs activation. In IUA mice models, BPTES treatment significantly ameliorated endometrial fibrosis and improved pregnancy outcomes. CONCLUSION: Glutaminolysis and glutaminolysis-associated mTOR signaling play a role in the activation of ESCs and the pathogenesis of endometrial fibrosis through regulating mitochondrial function. Glutaminolysis inhibition suppresses the activation of ESCs, which might be a novel therapeutic strategy for IUA.
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Glutamina , Mitocôndrias , Feminino , Camundongos , Humanos , Animais , Glutamina/metabolismo , Fibrose , Mitocôndrias/patologia , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , RNA/metabolismo , Endométrio/metabolismo , Endométrio/patologiaRESUMO
Background Endometrial fibrosis, a significant characteristic of intrauterine adhesion (IUA), is caused by the excessive differentiation and activation of endometrial stromal cells (ESCs). Glutaminolysis is the metabolic process of glutamine (Gln), which has been implicated in multiple types of organ fibrosis. So far, little is known about whether glutaminolysis plays a role in endometrial fibrosis. Methods The activation model of ESCs was constructed by TGF-β1, followed by RNA-sequencing analysis. Changes in glutaminase1 (GLS1) expression at RNA and protein levels in activated ESCs were verified experimentally. Human IUA samples were collected to verify GLS1 expression in endometrial fibrosis. GLS1 inhibitor and glutamine deprivation were applied to ESCs models to investigate the biological functions and mechanisms of glutaminolysis in ESCs activation. The IUA mice model was established to explore the effect of glutaminolysis inhibition on endometrial fibrosis. Results We found that GLS1 expression was significantly increased in activated ESCs models and fibrotic endometrium. Glutaminolysis inhibition by GLS1 inhibitor bis-2-(5-phenylacetamido-1,2,4-thiadiazol-2-yl) ethyl sulfide (BPTES or glutamine deprivation treatment suppressed the expression of two fibrotic markers, α-SMA and collagen I, as well as the mitochondrial function and mTORC1 signaling in ESCs. Furthermore, inhibition of the mTORC1 signaling pathway by rapamycin suppressed ESCs activation. In IUA mice models, BPTES treatment significantly ameliorated endometrial fibrosis and improved pregnancy outcomes. Conclusion Glutaminolysis and glutaminolysis-associated mTOR signaling play a role in the activation of ESCs and the pathogenesis of endometrial fibrosis through regulating mitochondrial function. Glutaminolysis inhibition suppresses the activation of ESCs, which might be a novel therapeutic strategy for IUA.
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L-glutaminase is a hydrolytic enzyme with wide biotechnological applications. Mostly, these enzymes are employed in the feed industry for flavor enhancement and acrylamide mitigation. Also, L-glutaminase may have antiviral and antineoplastic effects making it a good choice for pharmaceutical applications. In this study, the strain Monascus ruber URM 8542 was identified through classical and molecular taxonomy using partial sequencing of ß-tubulin and calmodulin genes. Subsequently, the optimal culture conditions were evaluated by submerged fermentation (L-glutamine 10 g.L- 1) for L-glutaminase excretion. The isolate was identified as M. ruber URM 8542 which showed significant extracellular enzyme production with a yield of 11.4 times in relation to the specific activity of intracellular L-glutaminase. Regarding the optimization experiments, several factors such as L-glutamine concentration, temperature, and pH were compared using a full factorial design (23). The concentrations greater than 1% proved to be significantly better for glutaminase production (R2 = 0.9077). Additionally, the L-glutaminase was optimally active at pH 7.0 and 30 ºC. The L-glutaminase was remarkably stable across an alkaline pH range (7.0-8.0) and had a thermal stability ranging from 30 ºC to 60 ºC for 1 h. Taken together, these findings suggest that the L-glutaminase produced by M. ruber is a promising candidate for pharmacological application, although further studies need to be performed. To the best of our knowledge, this is the first report of L-glutaminase production by Monascus ruber.
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Sorvetes , Monascus , Glutaminase/genética , Glutamina , Monascus/genéticaRESUMO
Persistent high-risk human papillomavirus infection is the main risk factor for cervical cancer establishment, where the viral oncogenes E6 and E7 promote a cancerous phenotype. Metabolic reprogramming in cancer involves alterations in glutamine metabolism, also named glutaminolysis, to provide energy for supporting cancer processes including migration, proliferation, and production of reactive oxygen species, among others. The aim of this work was to analyze the effect of HPV16 E6 and E7 oncoproteins on the regulation of glutaminolysis and its contribution to cell proliferation. We found that the E6 and E7 oncoproteins exacerbate cell proliferation in a glutamine-dependent manner. Both oncoproteins increased the levels of transporter SNAT1, as well as GLS2 and GS enzymes; E6 also increased LAT1 transporter protein levels, while E7 increased ASCT2 and xCT. Some of these alterations are also regulated at a transcriptional level. Consistently, the amount of SNAT1 protein decreased in Ca Ski cells when E6 and E7 expression was knocked down. In addition, we demonstrated that cell proliferation was partially dependent on SNAT1 in the presence of glutamine. Interestingly, SNAT1 expression was higher in cervical cancer compared with normal cervical cells. The high expression of SNAT1 was associated with poor overall survival of cervical cancer patients. Our results indicate that HPV oncoproteins exacerbate glutaminolysis supporting the malignant phenotype.
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Glutamina , Neoplasias do Colo do Útero , Feminino , Humanos , Proliferação de Células , Papillomavirus Humano 16/genética , Proteínas E7 de Papillomavirus/genética , Sistema A de Transporte de Aminoácidos/metabolismoRESUMO
BACKGROUND: Worldwide, gastric cancer is ranked the fifth malignancy in incidence and the third malignancy in mortality. Gastric cancer causes an altered metabolism that can be therapeutically exploited. OBJECTIVE: The objective of this study is to provide an overview of the significant metabolic alterations caused by gastric cancer and propose a blockade. METHODS: A comprehensive and up-to-date review of descriptive and experimental publications on the metabolic alterations caused by gastric cancer and their blockade. This is not a systematic review. RESULTS: Gastric cancer causes high rates of glycolysis and glutaminolysis. There are increased rates of de novo fatty acid synthesis and cholesterol synthesis. Moreover, gastric cancer causes high rates of lipid turnover via fatty acid ß-oxidation. Preclinical data indicate that the individual blockade of these pathways via enzyme targeting leads to antitumor effects in vitro and in vivo. Nevertheless, there is no data on the simultaneous blockade of these five pathways, which is critical as tumors show metabolic flexibility in response to the availability of nutrients. This means tumors may activate alternate routes when one or more are inhibited. We hypothesize there is a need to simultaneously block them to avoid or decrease the metabolic flexibility that may lead to treatment resistance. CONCLUSION: There is a need to explore the preclinical efficacy and feasibility of combined metabolic therapy targeting the pathways of glucose, glutamine, fatty acid synthesis, cholesterol synthesis, and fatty acid oxidation. This may have therapeutical implications because we have clinically available drugs that target these pathways in gastric cancer.
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Neoplasias Gástricas , Colesterol , Ácidos Graxos/metabolismo , Glutamina/metabolismo , Glicólise , Humanos , Neoplasias Gástricas/tratamento farmacológicoRESUMO
Cancer therapy advances have yet to impact global cancer mortality. One of the factors limiting mortality burden reduction is the high cost of cancer drugs. Cancer drug repurposing has already failed to meet expectations in terms of drug affordability. The three FDA-approved cancer drugs developed under repurposing: all-trans-retinoic acid, arsenic trioxide, and thalidomide do not differ in price from other drugs developed under the classical model. Though additional factors affect the whole process from inception to commercialization, the repurposing of widely used, commercially available, and cheap drugs may help. This work reviews the concept of the malignant metabolic phenotype and its exploitation by simultaneously blocking key metabolic processes altered in cancer. We elaborate on a combination called BAPST, which stands for the following drugs and pathways they inhibit: Benserazide (glycolysis), Apomorphine (glutaminolysis), Pantoprazole (Fatty-acid synthesis), Simvastatin (mevalonate pathway), and Trimetazidine (Fatty-acid oxidation). Their respective primary indications are: ⢠Parkinson's disease (benserazide and apomorphine). ⢠Peptic ulcer disease (pantoprazole). ⢠Hypercholesterolemia (simvastatin). ⢠Ischemic heart disease (trimetazidine). When used for their primary indication, the literature review on each of these drugs shows that they have a good safety profile and lack predicted pharmacokinetic interaction among them. Based on that, we propose that the BAPST regimen merits preclinical testing.
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Combinação de Medicamentos , Neoplasias , Apomorfina , Benserazida , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Pantoprazol , Sinvastatina , TrimetazidinaRESUMO
BACKGROUND: Glioblastoma is the most frequent and high-grade adult malignant central nervous system tumor. The prognosis is still poor despite the use of combined therapy involving maximal surgical resection, radiotherapy, and chemotherapy. Metabolic reprogramming currently is recognized as one of the hallmarks of cancer. Glutamine metabolism through glutaminolysis has been associated with tumor cell maintenance and survival, and with antioxidative stress through glutathione (GSH) synthesis. METHODS: In the present study, we analyzed the glutaminolysis-related gene expression levels in our cohort of 153 astrocytomas of different malignant grades and 22 non-neoplastic brain samples through qRT-PCR. Additionally, we investigated the protein expression profile of the key regulator of glutaminolysis (GLS), glutamate dehydrogenase (GLUD1), and glutamate pyruvate transaminase (GPT2) in these samples. We also investigated the glutathione synthase (GS) protein profile and the GSH levels in different grades of astrocytomas. The differential gene expressions were validated in silico on the TCGA database. RESULTS: We found an increase of glutaminase isoform 2 gene (GLSiso2) expression in all grades of astrocytoma compared to non-neoplastic brain tissue, with a gradual expression increment in parallel to malignancy. Genes coding for GLUD1 and GPT2 expression levels varied according to the grade of malignancy, being downregulated in glioblastoma, and upregulated in lower grades of astrocytoma (AGII-AGIII). Significant low GLUD1 and GPT2 protein levels were observed in the mesenchymal subtype of GBM. CONCLUSIONS: In glioblastoma, particularly in the mesenchymal subtype, the downregulation of both genes and proteins (GLUD1 and GPT2) increases the source of glutamate for GSH synthesis and enhances tumor cell fitness due to increased antioxidative capacity. In contrast, in lower-grade astrocytoma, mainly in those harboring the IDH1 mutation, the gene expression profile indicates that tumor cells might be sensitized to oxidative stress due to reduced GSH synthesis. The measurement of GLUD1 and GPT2 metabolic substrates, ammonia, and alanine, by noninvasive MR spectroscopy, may potentially allow the identification of IDH1mut AGII and AGIII progression towards secondary GBM.
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A virus minimally contains a nucleic acid genome packaged by a protein coat. The genome and capsid together are known as the nucleocapsid, which has an envelope containing a lipid bilayer (mainly phospholipids) originating from host cell membranes. The viral envelope has transmembrane proteins that are usually glycoproteins. The proteins in the envelope bind to host cell receptors, promoting membrane fusion and viral entry into the cell. Virus-infected host cells exhibit marked increases in glutamine utilization and metabolism. Glutamine metabolism generates ATP and precursors for the synthesis of macromolecules to assemble progeny viruses. Some compounds derived from glutamine are used in the synthesis of purines and pyrimidines. These latter compounds are precursors for the synthesis of nucleotides. Inhibitors of glutamine transport and metabolism are potential candidate antiviral drugs. Glutamine is also an essential nutrient for the functions of leukocytes (lymphocyte, macrophage, and neutrophil), including those in virus-infected patients. The increased glutamine requirement for immune cell functions occurs concomitantly with the high glutamine utilization by host cells in virus-infected patients. The development of antiviral drugs that target glutamine metabolism must then be specifically directed at virus-infected host cells to avoid negative effects on immune functions. Therefore, the aim of this review was to describe the landscape of cellular glutamine metabolism to search for potential candidates to inhibit glutamine transport or glutamine metabolism.
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Antivirais/farmacologia , Glutamina/metabolismo , Redes e Vias Metabólicas/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos , Linhagem Celular Tumoral , Interações Hospedeiro-Patógeno , Humanos , Neoplasias/metabolismo , Neoplasias/virologia , Virulência/efeitos dos fármacos , Vírus/efeitos dos fármacos , Vírus/patogenicidadeRESUMO
Colon cancer is a highly anabolic entity with upregulation of glycolysis, glutaminolysis, and de novo synthesis of fatty acids, which also induces a hypercatabolic state in the patient. The blockade of either cancer anabolism or host catabolism has been previously proven to be a successful anticancer experimental treatment. However, it is still unclear whether the simultaneous blockade of both metabolic counterparts can limit malignant survival and the energetic consequences of such an approach. In this chapter, by using the CT26.WT murine colon adenocarcinoma cell line as a model of study, we provide a method to simultaneously perform a pharmacological blockade of tumor anabolism and host catabolism, as a feasible therapeutic approach to treat cancer, and to limit its energetic supply.