Novel bioactive extract from yarrow obtained by the supercritical antisolvent-assisted technique inhibits lipid metabolism in colorectal cancer

Background: Altered lipid metabolism in cancer is associated to dissemination and prognosis. Bioactive compounds naturally occurring in Achillea millefolium L. (yarrow) have been reported to exert antitumour activities. Food biotechnology may provide on-demand mixtures of bioactive compounds with complementary activities in cancer treatment. Methods: Supercritical-antisolvent-precipitation (SAS) has been applied to fractionate the bioactive compounds from an Ultrasound-Assisted-Extraction yarrow extract resulting in two extracts with distinct polarity, yarrow-precipitate-(PP) and yarrow-separator-(Sep). Total phenolic content and relevant essential oils have been characterized. Antioxidant, anti-inflammatory and antiproliferative activities have been compared. Moreover, the effect on the inhibition of colorectal cancer cells' bioenergetics has been evaluated. Results: Yarrow-PP exerted the highest antioxidant activity, even higher than the complete UAE-yarrow extract, meanwhile yarrow-Sep showed the highest anti-inflammatory activity, even higher than the complete UAE-yarrow extract. Interestingly, yarrow-Sep inhibited key lipid metabolic targets in CRC cells extensively shown to be implicated in cancer dissemination and prognosis -SREBF1, FASN, ABCA1 and HMGCR- and epithelial to mesenchymal targets-CDH1, ATP1B1, CDH2 and Vimentin-augmenting cell adhesion. Conclusions: In summary, SAS technology has been applied to provide a novel combination of bioactive compounds, yarrow-Sep, which merits further research to be proposed as a potential complementary nutraceutical in the treatment of CRC.

DMSA-coated IONPs trigger oxidative stress, mitochondrial metabolic reprograming and changes in mitochondrial disposition, hindering cell cycle progression of cancer cells

There is increasing interest in modulating the redox homeostasis of tumors since high levels of reactive oxygen species (ROS) make them more vulnerable to changes in these species. Nanomedicine offers promise in this context as such applications may provoke biological responses that induce ROS production. Indeed, iron oxide nanoparticles (IONPs) can induce ROS accumulation through the so-called Fenton reaction of iron, further augmenting the ROS in tumors and overloading the antioxidant system beyond its capacity, thereby driving oxidative stress to a level that is incompatible with cell survival. Here, three different coatings for IONPs were compared to assess their intrinsic capacity to induce ROS production in cells. Of these coatings, dimercaptosuccinic acid-coated IONPs (DMSA-NPs) provoked the strongest ROS production, which was associated with the ability to reprogram the metabolism of cancer cells. This latter phenomenon involved shutting-down oxidative phosphorylation (OXPHOS), shifting mitochondrial morphology towards a more elongated phenotype, reducing the total mitochondrial mass and ultimately, blocking cell proliferation by inducing G0/G1 cell cycle arrest. Consequently, the data obtained highlights the importance of studying the chemical properties of IONPs, presenting DMSA-NPs as a novel tool to induce oxidative stress in cancer cells and alter their cell fate.

Glycolytic shift during West Nile virus infection provides new therapeutic opportunities

BACKGROUND

Viral rewiring of host bioenergetics and immunometabolism may provide novel targets for therapeutic interventions against viral infections. Here, we have explored the effect on bioenergetics during the infection with the mosquito-borne flavivirus West Nile virus (WNV), a medically relevant neurotropic pathogen causing outbreaks of meningitis and encephalitis worldwide.

RESULTS

A systematic literature search and meta-analysis pointed to a misbalance of glucose homeostasis in the central nervous system of WNV patients. Real-time bioenergetic analyses confirmed upregulation of aerobic glycolysis and a reduction of mitochondrial oxidative phosphorylation during viral replication in cultured cells. Transcriptomics analyses in neural tissues from experimentally infected mice unveiled a glycolytic shift including the upregulation of hexokinases 2 and 3 (Hk2 and Hk3) and pyruvate dehydrogenase kinase 4 (Pdk4). Treatment of infected mice with the Hk inhibitor, 2-deoxy-D-glucose, or the Pdk4 inhibitor, dichloroacetate, alleviated WNV-induced neuroinflammation.

CONCLUSIONS

These results highlight the importance of host energetic metabolism and specifically glycolysis in WNV infection in vivo. This study provides proof of concept for the druggability of the glycolytic pathway for the future development of therapies to combat WNV pathology.

Metabolo-epigenetic interplay provides targeted nutritional interventions in chronic diseases and ageing

Epigenetic modifications are chemical modifications that affect gene expression without altering DNA sequences. In particular, epigenetic chemical modifications can occur on histone proteins -mainly acetylation, methylation-, and on DNA and RNA molecules -mainly methylation-. Additional mechanisms, such as RNA-mediated regulation of gene expression and determinants of the genomic architecture can also affect gene expression. Importantly, depending on the cellular context and environment, epigenetic processes can drive developmental programs as well as functional plasticity. However, misbalanced epigenetic regulation can result in disease, particularly in the context of metabolic diseases, cancer, and ageing. Non-communicable chronic diseases (NCCD) and ageing share common features including altered metabolism, systemic meta-inflammation, dysfunctional immune system responses, and oxidative stress, among others. In this scenario, unbalanced diets, such as high sugar and high saturated fatty acids consumption, together with sedentary habits, are risk factors implicated in the development of NCCD and premature ageing. The nutritional and metabolic status of individuals interact with epigenetics at different levels. Thus, it is crucial to understand how we can modulate epigenetic marks through both lifestyle habits and targeted clinical interventions -including fasting mimicking diets, nutraceuticals, and bioactive compounds- which will contribute to restore the metabolic homeostasis in NCCD. Here, we first describe key metabolites from cellular metabolic pathways used as substrates to "write" the epigenetic marks; and cofactors that modulate the activity of the epigenetic enzymes; then, we briefly show how metabolic and epigenetic imbalances may result in disease; and, finally, we show several examples of nutritional interventions - diet based interventions, bioactive compounds, and nutraceuticals- and exercise to counteract epigenetic alterations.

Biological Activities of Miracle Berry Supercritical Extracts as Metabolic Regulators in Chronic Diseases

Synsepalum dulcificum (Richardella dulcifica) is a berry fruit from West Africa with the ability to convert the sour taste into a sweet taste, and for this reason, the fruit is also known as the "miracle berry" (MB). The red and bright berry is rich in terpenoids. The fruit's pulp and skin contain mainly phenolic compounds and flavonoids, which correlate with their antioxidant activity. Different polar extracts have been described to inhibit cell proliferation and transformation of cancer cell lines in vitro. In addition, MB has been shown to ameliorate insulin resistance in a preclinical model of diabetes induced by a chow diet enriched in fructose. Herein, we have compared the biological activities of three supercritical extracts obtained from the seed-a subproduct of the fruit-and one supercritical extract obtained from the pulp and the skin of MB. The four extracts have been characterized in terms of total polyphenols content. Moreover, the antioxidant, anti-inflammatory, hypo-lipidemic, and inhibition of colorectal cancer cell bioenergetics have been compared. Non-polar supercritical extracts from the seed are the ones with the highest effects on the inhibition of bioenergetic of colorectal (CRC) cancer cells. At the molecular level, the effects on cell bioenergetics seems to be related to the inhibition of main drivers of the de novo lipogenesis, such as the sterol regulatory element binding transcription factor (SREBF1) and downstream molecular targets fatty acid synthase (FASN) and stearoyl coenzyme desaturase 1 (SCD1). As metabolic reprograming is considered as one of the hallmarks of cancer, natural extracts from plants may provide complementary approaches in the treatment of cancer. Herein, for the first time, supercritical extracts from MB have been obtained, where the seed, a by-product of the fruit, seems to be rich in antitumor bioactive compounds. Based on these results, supercritical extracts from the seed merit further research to be proposed as co-adjuvants in the treatment of cancer.

NOX2 and NOX4 control mitochondrial function in chronic myeloid leukaemia

Cancer cells are characterised by an elevated metabolic plasticity and enhanced production of reactive oxygen species (ROS), two features acknowledged as hallmarks in cancer, with a high translational potential to the therapeutic setting. These aspects, that have been traditionally studied separately, are in fact intimately intermingled. As part of their transforming activity, some oncogenes stimulate rewiring of metabolic processes, whilst simultaneously promoting increased production of intracellular ROS. In this scenario the latest discoveries suggest the relevance of nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (NOX) to connect ROS production and metabolic control. Here we have analysed the relevance of NOX2 and NOX4 in the regulation of metabolism in chronic myeloid leukaemia (CML), a neoplasia driven by the expression of the breakpoint cluster region-Abelson fusion oncogene (BCR-ABL). Silencing of NOX2 enhances glycolysis and oxidative phosphorylation rates, together with an enhanced production of mitochondrial ROS and a decrease in mitochondrial DNA copy number, which reflects mitochondrial dysfunction. NOX4 expression was upregulated upon NOX2 silencing, and this was required to alter mitochondrial function. Our results support the relevance of NOX2 to regulate metabolism-related signalling pathways downstream of BCR-ABL. Overall we show that NOX2, through the regulation of NOX4 expression, controls metabolism and mitochondrial function in CML cells. This notion was confirmed by transcriptomic analyses, that strongly relate both NOX isoforms with metabolism regulation in CML.

Mitochondrial RNA methyltransferase TRMT61B is a new, potential biomarker and therapeutic target for highly aneuploid cancers

Despite being frequently observed in cancer cells, chromosomal instability (CIN) and its immediate consequence, aneuploidy, trigger adverse effects on cellular homeostasis that need to be overcome by anti-stress mechanisms. As such, these safeguard responses represent a tumor-specific Achilles heel, since CIN and aneuploidy are rarely observed in normal cells. Recent data have revealed that epitranscriptomic marks catalyzed by RNA-modifying enzymes change under various stress insults. However, whether aneuploidy is associated with such RNA modifying pathways remains to be determined. Through an in silico search for aneuploidy biomarkers in cancer cells, we found TRMT61B, a mitochondrial RNA methyltransferase enzyme, to be associated with high levels of aneuploidy. Accordingly, TRMT61B protein levels are increased in tumor cell lines with an imbalanced karyotype as well as in different tumor types when compared to control tissues. Interestingly, while TRMT61B depletion induces senescence in melanoma cell lines with low levels of aneuploidy, it leads to apoptosis in cells with high levels. The therapeutic potential of these results was further validated by targeting TRMT61B in transwell and xenografts assays. We show that TRM61B depletion reduces the expression of several mitochondrial encoded proteins and limits mitochondrial function. Taken together, these results identify a new biomarker of aneuploidy in cancer cells that could potentially be used to selectively target highly aneuploid tumors.

Phenolic diterpenes from Rosemary supercritical extract inhibit non-small cell lung cancer lipid metabolism and synergise with therapeutic drugs in the clinic

Lung cancer is one of the most deadly and common cancers in the world. The molecular features of patient's tumours dictate the different therapeutic decisions, which combines targeted therapy, chemotherapy, and immunotherapy. Altered cellular metabolism is one of the hallmarks of cancer. Tumour cells reprogram their metabolism to adapt to their novel requirements of growth, proliferation, and survival. Together with the Warburg effect, the role of lipid metabolism alterations in cancer development and prognosis has been highlighted. Several lipid related genes have been shown to promote transformation and progression of cancer cells and have been proposed as biomarkers for prognosis. Nevertheless, the exact mechanisms of the regulation of lipid metabolism and the biological consequences in non-small cell lung cancer (NSCLC) have not been elucidated yet. There is an urgent necessity to develop multidisciplinary and complementary strategies to improve NSCLC patients´ well-being and treatment response. Nutrients can directly affect fundamental cellular processes and some diet-derived ingredients, bioactive natural compounds and natural extracts have been shown to inhibit the tumour growth in preclinical and clinical trials. Previously, we described a supercritical extract of rosemary (SFRE) (12 - 16% composition of phenolic diterpenes carnosic acid and carnosol) as a potential antitumoral agent in colon and breast cancer due to its effects on the inhibition of lipid metabolism and DNA synthesis, and in the reduction of resistance to 5-FluoroUracil (5-FU). Herein, we demonstrate SFRE inhibits NSCLC cell bioenergetics identifying several lipid metabolism implicated targets. Moreover, SFRE synergises with standard therapeutic drugs used in the clinic, such as cisplatin, pemetrexed and pembrolizumab to inhibit of cell viability of NSCLC cells. Importantly, the clinical relevance of SFRE as a complement in the treatment of NSCLC patients is suggested based on the results of a pilot clinical trial where SFRE formulated with bioactive lipids (PCT/ES2017/070263) diminishes metabolic and inflammatory targets in peripheral-blood mononuclear cells (PBMC), such as MAPK (p=0.04), NLRP3 (p=0.044), and SREBF1 (p=0.047), which may augment the immune antitumour function. Based on these results, SFRE merits further investigation as a co-adjuvant in the treatment of NSCLC.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT05080920.

Pomegranate Extract Augments Energy Expenditure Counteracting the Metabolic Stress Associated with High-Fat-Diet-Induced Obesity

Obesity is associated to a low grade of chronic inflammation leading to metabolic stress, insulin resistance, metabolic syndrome, dislipidemia, cardiovascular disease, and even cancer. A Mediterranean diet has been shown to reduce systemic inflammatory factors, insulin resistance, and metabolic syndrome. In this scenario, precision nutrition may provide complementary approaches to target the metabolic alterations associated to “unhealthy obesity”. In a previous work, we described a pomegranate extract (PomE) rich in punicalagines to augment markers of browning and thermogenesis in human differentiated adipocytes and to augment the oxidative respiratory capacity in human differentiated myocytes. Herein, we have conducted a preclinical study of high-fat-diet (HFD)-induced obesity where PomE augments the systemic energy expenditure (EE) contributing to a reduction in the low grade of chronic inflammation and insulin resistance associated to obesity. At the molecular level, PomE promotes browning and thermogenesis in adipose tissue, reducing inflammatory markers and augmenting the reductive potential to control the oxidative stress associated to the HFD. PomE merits further investigation as a complementary approach to alleviate obesity, reducing the low grade of chronic inflammation and metabolic stress.

Metabolic Reprogramming Helps to Define Different Metastatic Tropisms in Colorectal Cancer

Approximately 25% of colorectal cancer (CRC) patients experience systemic metastases, with the most frequent target organs being the liver and lung. Metabolic reprogramming has been recognized as one of the hallmarks of cancer. Here, metabolic and functional differences between two CRC cells with different metastatic organotropisms (metastatic KM12SM CRC cells to the liver and KM12L4a to the lung when injected in the spleen and in the tail vein of mice) were analysed in comparison to their parental non-metastatic isogenic KM12C cells, for a subsequent investigation of identified metabolic targets in CRC patients. Meta-analysis from proteomic and transcriptomic data deposited in databases, qPCR, WB, in vitro cell-based assays, and in vivo experiments were used to survey for metabolic alterations contributing to their different organotropism and for the subsequent analysis of identified metabolic markers in CRC patients. Although no changes in cell proliferation were observed between metastatic cells, KM12SM cells were highly dependent on oxidative phosphorylation at mitochondria, whereas KM12L4a cells were characterized by being more energetically efficient with lower basal respiration levels and a better redox management. Lipid metabolism-related targets were found altered in both cell lines, including LDLR, CD36, FABP4, SCD, AGPAT1, and FASN, which were also associated with the prognosis of CRC patients. Moreover, CD36 association with lung metastatic tropism of CRC cells was validated in vivo. Altogether, our results suggest that LDLR, CD36, FABP4, SCD, FASN, LPL, and APOA1 metabolic targets are associated with CRC metastatic tropism to the liver or lung. These features exemplify specific metabolic adaptations for invasive cancer cells which stem at the primary tumour.

Potential protective effect against SARS-CoV-2 infection by APOE rs7412 polymorphism

The pandemic burden caused by the SARS-CoV-2 coronavirus constitutes a global public health emergency. Increasing understanding about predisposing factors to infection and severity is now a priority. Genetic, metabolic, and environmental factors can play a crucial role in the course and clinical outcome of COVID-19. We aimed to investigate the putative relationship between genetic factors associated to obesity, metabolism and lifestyle, and the presence and severity of SARS-CoV-2 infection. A total of 249 volunteers (178 women and 71 men, with mean and ± SD age of 49 ± 11 years) characterized for dietary, lifestyle habits and anthropometry, were studied for presence and severity of COVID-19 infection, and genotyped for 26 genetic variants related to obesity, lipid profile, inflammation, and biorhythm patterns. A statistically significant association was found concerning a protective effect of APOE rs7412 against SARS-CoV-2 infection (p = 0.039; OR 0.216; CI 0.084, 0.557) after correction for multiple comparisons. This protective effect was also ascribed to the APOɛ2 allele (p = 0.001; OR 0.207; CI 0.0796, 0.538). The genetic variant rs7412 resulting in ApoE2, genetic determinant of lipid and lipoprotein levels, could play a significant role protecting against SARS-CoV-2 infection.

The Chemokine Receptor CCR5 Links Memory CD4+ T Cell Metabolism to T Cell Antigen Receptor Nanoclustering

The inhibition of anabolic pathways, such as aerobic glycolysis, is a metabolic cornerstone of memory T cell differentiation and function. However, the signals that hamper these anabolic pathways are not completely known. Recent evidence pinpoints the chemokine receptor CCR5 as an important player in CD4⁺ T cell memory responses by regulating T cell antigen receptor (TCR) nanoclustering in an antigen-independent manner. This paper reports that CCR5 specifically restrains aerobic glycolysis in memory-like CD4⁺ T cells, but not in effector CD4⁺ T cells. CCR5-deficient memory CD4⁺ T cells thus show an abnormally high glycolytic/oxidative metabolism ratio. No CCR5-dependent change in glucose uptake nor in the expression of the main glucose transporters was detected in any of the examined cell types, although CCR5-deficient memory cells did show increased expression of the hexokinase 2 and pyruvate kinase M2 isoforms, plus the concomitant downregulation of Bcl-6, a transcriptional repressor of these key glycolytic enzymes. Further, the TCR nanoclustering defects observed in CCR5-deficient antigen-experienced CD4⁺ T cells were partially reversed by incubation with 2-deoxyglucose (2-DG), suggesting a link between inhibition of the glycolytic pathway and TCR nanoscopic organization. Indeed, the treatment of CCR5-deficient lymphoblasts with 2-DG enhanced IL-2 production after antigen re-stimulation. These results identify CCR5 as an important regulator of the metabolic fitness of memory CD4⁺ T cells, and reveal an unexpected link between T cell metabolism and TCR organization with potential influence on the response of memory T cells upon antigen re-encounter.

Natural Extracts to Augment Energy Expenditure as a Complementary Approach to Tackle Obesity and Associated Metabolic Alterations

Obesity is the epidemic of the 21st century. In developing countries, the prevalence of obesity continues to rise, and obesity is occurring at younger ages. Obesity and associated metabolic stress disrupt the whole-body physiology. Adipocytes are critical components of the systemic metabolic control, functioning as an endocrine organ. The enlarged adipocytes during obesity recruit macrophages promoting chronic inflammation and insulin resistance. Together with the genetic susceptibility (single nucleotide polymorphisms, SNP) and metabolic alterations at the molecular level, it has been highlighted that key modifiable risk factors, such as those related to lifestyle, contribute to the development of obesity. In this scenario, urgent therapeutic options are needed, including not only pharmacotherapy but also nutrients, bioactive compounds, and natural extracts to reverse the metabolic alterations associated with obesity. Herein, we first summarize the main targetable processes to tackle obesity, including activation of thermogenesis in brown adipose tissue (BAT) and in white adipose tissue (WAT-browning), and the promotion of energy expenditure and/or fatty acid oxidation (FAO) in muscles. Then, we perform a screening of 20 natural extracts (EFSA approved) to determine their potential in the activation of FAO and/or thermogenesis, as well as the increase in respiratory capacity. By means of innovative technologies, such as the study of their effects on cell bioenergetics (Seahorse bioanalyzer), we end up with the selection of four extracts with potential application to ameliorate the deleterious effects of obesity and the chronic associated inflammation.

Precision Nutrition to Activate Thermogenesis as a Complementary Approach to Target Obesity and Associated-Metabolic-Disorders

Simple Summary

Regarding the pandemic of obesity and chronic diseases associated to metabolic alterations that occur nowadays worldwide, here, we review the most recent studies related to bioactive compounds and diet derived ingredients with potential effects to augment the systemic energy expenditure. We specifically focus in two processes: the activation of thermogenesis in adipose tissue and the enhancement of the mitochondrial oxidative phosphorylation capacity in muscles. This may provide relevant information to develop diets and supplements to conduct nutritional intervention studies with the objective to ameliorate the metabolic and chronic inflammation in the course of obesity and related disorders.

Abstract

Obesity is associated to increased incidence and poorer prognosis in multiple cancers, contributing to up to 20% of cancer related deaths. These associations are mainly driven by metabolic and inflammatory changes in the adipose tissue during obesity, which disrupt the physiologic metabolic homeostasis. The association between obesity and hypercholesterolemia, hypertension, cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM) is well known. Importantly, the retrospective analysis of more than 1000 epidemiological studies have also shown the positive correlation between the excess of fatness with the risk of cancer. In addition, more important than weight, it is the dysfunctional adipose tissue the main driver of insulin resistance, metabolic syndrome and all cause of mortality and cancer deaths, which also explains why normal weight individuals may behave as “metabolically unhealthy obese” individuals. Adipocytes also have direct effects on tumor cells through paracrine signaling. Downregulation of adiponectin and upregulation of leptin in serum correlate with markers of chronic inflammation, and crown like structures (CLS) associated to the adipose tissue disfunction. Nevertheless, obesity is a preventable risk factor in cancer. Lifestyle interventions might contribute to reduce the adverse effects of obesity. Thus, Mediterranean diet interventional studies have been shown to reduce to circulation inflammatory factors, insulin sensitivity and cardiovascular function, with durable responses of up to 2 years in obese patients. Mediterranean diet supplemented with extra-virgin olive oil reduced the incidence of breast cancer compared with a control diet. Physical activity is another important lifestyle factor which may also contribute to reduced systemic biomarkers of metabolic syndrome associated to obesity. In this scenario, precision nutrition may provide complementary approaches to target the metabolic inflammation associated to “unhealthy obesity”. Herein, we first describe the different types of adipose tissue -thermogenic active brown adipose tissue (BAT) versus the energy storing white adipose tissue (WAT). We then move on precision nutrition based strategies, by mean of natural extracts derived from plants and/or diet derived ingredients, which may be useful to normalize the metabolic inflammation associated to “unhealthy obesity”. More specifically, we focus on two axis: (1) the activation of thermogenesis in BAT and browning of WAT; (2) and the potential of augmenting the oxidative capacity of muscles to dissipate energy. These strategies may be particularly relevant as complementary approaches to alleviate obesity associated effects on chronic inflammation, immunosuppression, angiogenesis and chemotherapy resistance in cancer. Finally, we summarize main studies where plant derived extracts, mainly, polyphenols and flavonoids, have been applied to increase the energy expenditure.

Miracle Berry as a Potential Supplement in the Control of Metabolic Risk Factors in Cancer

The increased incidence of chronic diseases related to altered metabolism has become a social and medical concern worldwide. Cancer is a chronic and multifactorial disease for which, together with genetic factors, environmental factors are crucial. According to the World Health Organization (WHO), up to one third of cancer-related deaths could be prevented by modifying risk factors associated with lifestyle, including diet and exercise. Obesity increases the risk of cancer due to the promotion of low-grade chronic inflammation and systemic metabolic oxidative stress. The effective control of metabolic parameters, for example, controlling glucose, lipid levels, and blood pressure, and maintaining a low grade of chronic inflammation and oxidative stress might represent a specific and mechanistic approach against cancer initiation and progression. Miracle berry (MB) (Synsepalum dulcificum) is an indigenous fruit whose small, ellipsoid, and bright red berries have been described to transform a sour taste into a sweet one. MB is rich in terpenoids, phenolic compounds, and flavonoids, which are responsible for their described antioxidant activities. Moreover, MB has been reported to ameliorate insulin resistance and inhibit cancer cell proliferation and malignant transformation in vitro. Herein, we briefly summarize the current knowledge of MB to provide a scientific basis for its potential use as a supplement in the management of chronic diseases related to altered metabolism, including obesity and insulin resistance, which are well-known risk factors in cancer. First, we introduce cancer as a metabolic disease, highlighting the impact of systemic metabolic alterations, such as obesity and insulin resistance, in cancer initiation and progression. Next, as oxidative stress is closely associated with metabolic stress, we also evaluate the effect of phytochemicals in managing oxidative stress and its relationship with cancer. Finally, we summarize the main biological activities described for MB-derived extracts with a special focus on the ability of miraculin to transform a sour taste into a sweet one through its interaction with the sweet taste receptors. The identification of sweet taste receptors at the gastrointestinal level, with effects on the secretion of enterohormones, may provide an additional tool for managing chronic diseases, including cancer.

Targeting metabolic plasticity in glioma stem cells in vitro and in vivo through specific inhibition of c-Src by TAT-Cx43266-283

Background

Glioblastoma is the most aggressive primary brain tumour and has a very poor prognosis. Inhibition of c-Src activity in glioblastoma stem cells (GSCs, responsible for glioblastoma lethality) and primary glioblastoma cells by the peptide TAT-Cx43_266–283 reduces tumorigenicity, and boosts survival in preclinical models. Because c-Src can modulate cell metabolism and several reports revealed poor clinical efficacy of various antitumoral drugs due to metabolic rewiring in cancer cells, here we explored the inhibition of advantageous GSC metabolic plasticity by the c-Src inhibitor TAT-Cx43_266-283.

Methods

Metabolic impairment induced by the c-Src inhibitor TAT-Cx43_266-283 in vitro was assessed by fluorometry, western blotting, immunofluorescence, qPCR, enzyme activity assays, electron microscopy, Seahorse analysis, time-lapse imaging, siRNA, and MTT assays. Protein expression in tumours from a xenograft orthotopic glioblastoma mouse model was evaluated by immunofluorescence.

Findings

TAT-Cx43_266–283 decreased glucose uptake in human GSCs and reduced oxidative phosphorylation without a compensatory increase in glycolysis, with no effect on brain cell metabolism, including rat neurons, human and rat astrocytes, and human neural stem cells. TAT-Cx43_266-283 impaired metabolic plasticity, reducing GSC growth and survival under different nutrient environments. Finally, GSCs intracranially implanted with TAT-Cx43_266–283 showed decreased levels of important metabolic targets for cancer therapy, such as hexokinase-2 and GLUT-3.

Interpretation

The reduced ability of TAT-Cx43_266-283–treated GSCs to survive in metabolically challenging settings, such as those with restricted nutrient availability or the ever-changing in vivo environment, allows us to conclude that the advantageous metabolic plasticity of GSCs can be therapeutically exploited through the specific and cell-selective inhibition of c-Src by TAT-Cx43_266-283.

Funding

Spanish Ministerio de Economía y Competitividad (FEDER BFU2015-70040-R and FEDER RTI2018-099873-B-I00), Fundación Ramón Areces. Fellowships from the Junta de Castilla y León, European Social Fund, Ministerio de Ciencia and Asociación Española Contra el Cáncer (AECC).

Saponin-Rich Extracts and Their Acid Hydrolysates Differentially Target Colorectal Cancer Metabolism in the Frame of Precision Nutrition

Saponins or their aglycone form, sapogenin, have recently gained interest as bioactive agents due to their biological activities, their antitumoral effects being among them. Metabolic reprogramming has been recognized as a hallmark of cancer and, together with the increased aerobic glycolysis and glutaminolysis, the altered lipid metabolism is considered crucial to support cancer initiation and progression. The purpose of this study was to assess and compare the inhibitory effects on colorectal cancer cell lines of saponin-rich extracts from fenugreek and quinoa (FE and QE, respectively) and their hydrolyzed extracts as sapogenin-rich extracts (HFE and HQE, respectively). By mean of the latest technology in the analysis of cell bioenergetics, we demonstrate that FE and HFE diminished mitochondrial oxidative phosphorylation and aerobic glycolysis; meanwhile, quinoa extracts did not show relevant activities. Distinct molecular mechanisms were identified for fenugreek: FE inhibited the expression of TYMS1 and TK1, synergizing with the chemotherapeutic drug 5-fluorouracil (5-FU); meanwhile, HFE inhibited lipid metabolism targets, leading to diminished intracellular lipid content. The relevance of considering the coexisting compounds of the extracts or their hydrolysis transformation as innovative strategies to augment the therapeutic potential of the extracts, and the specific subgroup of patients where each extract would be more beneficial, are discussed in the frame of precision nutrition.

Metabolic enzyme ACSL3 is a prognostic biomarker and correlates with anticancer effectiveness of statins in non-small cell lung cancer

Lung cancer is one of the most common cancers, still characterized by high mortality rates. As lipid metabolism contributes to cancer metabolic reprogramming, several lipid metabolism genes are considered prognostic biomarkers of cancer. Statins are a class of lipid-lowering compounds used in treatment of cardiovascular disease that are currently studied for their antitumor effects. However, their exact mechanism of action and specific conditions in which they should be administered remains unclear. Here, we found that simvastatin treatment effectively promoted antiproliferative effects and modulated lipid metabolism-related pathways in non-small cell lung cancer (NSCLC) cells and that the antiproliferative effects of statins were potentiated by overexpression of acyl-CoA synthetase long-chain family member 3 (ACSL3). Moreover, ACSL3 overexpression was associated with worse clinical outcome in patients with high-grade NSCLC. Finally, we found that patients with high expression levels of ACSL3 displayed a clinical benefit of statins treatment. Therefore, our study highlights ACSL3 as a prognostic biomarker for NSCLC, useful to select patients who would obtain a clinical benefit from statin administration.

Alterations of Lipid Metabolism in Cancer: Implications in Prognosis and Treatment

Cancer remains the second leading cause of mortality worldwide. In the course of this multistage and multifactorial disease, a set of alterations takes place, with genetic and environmental factors modulating tumorigenesis and disease progression. Metabolic alterations of tumors are well-recognized and are considered as one of the hallmarks of cancer. Cancer cells adapt their metabolic competences in order to efficiently supply their novel demands of energy to sustain cell proliferation and metastasis. At present, there is a growing interest in understanding the metabolic switch that occurs during tumorigenesis. Together with the Warburg effect and the increased glutaminolysis, lipid metabolism has emerged as essential for tumor development and progression. Indeed, several investigations have demonstrated the consequences of lipid metabolism alterations in cell migration, invasion, and angiogenesis, three basic steps occurring during metastasis. In addition, obesity and associated metabolic alterations have been shown to augment the risk of cancer and to worsen its prognosis. Consequently, an extensive collection of tumorigenic steps has been shown to be modulated by lipid metabolism, not only affecting the growth of primary tumors, but also mediating progression and metastasis. Besides, key enzymes involved in lipid-metabolic pathways have been associated with cancer survival and have been proposed as prognosis biomarkers of cancer. In this review, we will analyze the impact of obesity and related tumor microenviroment alterations as modifiable risk factors in cancer, focusing on the lipid alterations co-occurring during tumorigenesis. The value of precision technologies and its application to target lipid metabolism in cancer will also be discussed. The degree to which lipid alterations, together with current therapies and intake of specific dietary components, affect risk of cancer is now under investigation, and innovative therapeutic or preventive applications must be explored.

Non-Coding and Regulatory RNAs as Epigenetic Remodelers of Fatty Acid Homeostasis in Cancer

Cancer cells commonly display metabolic fluctuations. Together with the Warburg effect and the increased glutaminolysis, alterations in lipid metabolism homeostasis have been recognized as a hallmark of cancer. Highly proliferative cancer cells upregulate de novo synthesis of fatty acids (FAs) which are required to support tumor progression by exerting multiple roles including structural cell membrane composition, regulators of the intracellular redox homeostasis, ATP synthesis, intracellular cell signaling molecules, and extracellular mediators of the tumor microenvironment. Epigenetic modifications have been shown to play a crucial role in human development, but also in the initiation and progression of complex diseases. The study of epigenetic processes could help to design new integral strategies for the prevention and treatment of metabolic disorders including cancer. Herein, we first describe the main altered intracellular fatty acid processes to support cancer initiation and progression. Next, we focus on the most important regulatory and non-coding RNAs (small noncoding RNA-sncRNAs-long non-coding RNAs-lncRNAs-and other regulatory RNAs) which may target the altered fatty acids pathway in cancer.

Transient exposure to miR-203 enhances the differentiation capacity of established pluripotent stem cells

Full differentiation potential along with self-renewal capacity is a major property of pluripotent stem cells (PSCs). However, the differentiation capacity frequently decreases during expansion of PSCs in vitro. We show here that transient exposure to a single microRNA, expressed at early stages during normal development, improves the differentiation capacity of already-established murine and human PSCs. Short exposure to miR-203 in PSCs (miPSCs) induces a transient expression of 2C markers that later results in expanded differentiation potency to multiple lineages, as well as improved efficiency in tetraploid complementation and human-mouse interspecies chimerism assays. Mechanistically, these effects are at least partially mediated by direct repression of de novo DNA methyltransferases Dnmt3a and Dnmt3b, leading to transient and reversible erasure of DNA methylation. These data support the use of transient exposure to miR-203 as a versatile method to reset the epigenetic memory in PSCs, and improve their effectiveness in regenerative medicine.

Coordinate β-adrenergic inhibition of mitochondrial activity and angiogenesis arrest tumor growth

Mitochondrial metabolism has emerged as a promising target against the mechanisms of tumor growth. Herein, we have screened an FDA-approved library to identify drugs that inhibit mitochondrial respiration. The β1-blocker nebivolol specifically hinders oxidative phosphorylation in cancer cells by concertedly inhibiting Complex I and ATP synthase activities. Complex I inhibition is mediated by interfering the phosphorylation of NDUFS7. Inhibition of the ATP synthase is exerted by the overexpression and binding of the ATPase Inhibitory Factor 1 (IF1) to the enzyme. Remarkably, nebivolol also arrests tumor angiogenesis by arresting endothelial cell proliferation. Altogether, targeting mitochondria and angiogenesis triggers a metabolic and oxidative stress crisis that restricts the growth of colon and breast carcinomas. Nebivolol holds great promise to be repurposed for the treatment of cancer patients.

Marigold Supercritical Extract as Potential Co-adjuvant in Pancreatic Cancer: The Energetic Catastrophe Induced via BMP8B Ends Up With Autophagy-Induced Cell Death

The recent development of powerful "omics" technologies (genomics, transcriptomics, proteomics, metabolomics, and lipidomics) has opened new avenues in nutritional sciences toward precision nutrition, which is a genotype-directed nutrition that takes into account the differential responses to nutritional interventions based on gene variation (nutrigenetics) and the effect of nutrients on gene expression (nutrigenomics). Current evidence demonstrates that up to one third of the deaths caused by cancer could be prevented by acting on key risk factors, with diet being one of the most important risk factors due to its association with obesity. Additional factors such as composition of gut microbiome, the immune system, and the nutritional status will have an impact on the final outcome. Nutrient components and bioactive compounds from natural sources can have an impact on cancer progression or even the risk of cancer development by regulating gene expression and/or associated risk factors such as obesity and chronic inflammation. Nowadays, among the different methods to produce natural extracts, the green technology of supercritical fluid extraction (SFE) is quite popular, with a special interest on the use of supercritical CO₂ for the extraction of compounds with low polarity. The success of nutritional interventions based on the use of nutraceuticals requires several steps: (i) in vitro and preclinical demonstration of their antitumoral effects; (ii) knowledge of their mechanism of action and molecular targets, which will allow for identification of the specific subgroups of patients who will benefit from them; (iii) the study of genetic variants associated with the differential responses; and (iv) innovative approaches of formulations to improve the in vivo bioavailability of the bioactive ingredients. Herein, we investigate the antitumoral properties and mechanism of action of a supercritical CO₂ extract from Calendula officinalis, commonly known as marigold (marigold SFE) in the context of pancreatic cancer. Mechanistically, marigold SFE induces the expression of BMP8B, which leads to an energetic catastrophe ending up with autophagy-induced cell death (AICD). As metabolic reprogramming is a well-recognized hallmark of cancer, the direct impact of marigold SFE on pancreatic cancer cell metabolism encourages further research of its potential as a coadjuvant in pancreatic cancer therapy. Finally, we discuss innovative formulation approaches to augment the clinical therapeutic potential of marigold SFE in nutritional interventions.

Identification of antitumoral agents against human pancreatic cancer cells from Asteraceae and Lamiaceae plant extracts

Background

Pancreatic cancer is one of the most aggressive and mortal cancers. Although several drugs have been proposed for its treatment, it remains resistant and new alternatives are needed. In this context, plants and their derivatives constitute a relevant source of bioactive components which might efficiently inhibit tumor cell progression.

Methods

In this study, we have analyzed the potential anti-carcinogenic effect of different Asteraceae (Achillea millefolium and Calendula officinalis) and Lamiaceae (Melissa officinalis and Origanum majorana) plant extracts obtained by different green technologies (Supercritical CO₂ Extraction –SFE- and Ultrasonic Assisted Extraction –UAE-) to identify efficient plant extracts against human pancreatic cancer cells that could constitute the basis of novel treatment approaches.

Results

Asteraceae extracts showed better results as antitumoral agents than Lamiaceae by inducing cytotoxicity and inhibiting cell transformation, and SFE extracts were most efficient than UAE extracts. In addition, SFE derived plant extracts from Achillea millefolium and Calendula officinalis displayed synergism with the chemotherapeutic 5-Fluororacil.

Conclusion

These results show how Yarrow and Marigold SFE-derived extracts can inhibit pancreatic cancer cell growth, and could be proposed for a comprehensive study to determine the molecular mechanisms involved in their bioactivity with the final aim to propose them as potential adjuvants in pancreatic cancer therapy.

Electronic supplementary material

The online version of this article (10.1186/s12906-018-2322-6) contains supplementary material, which is available to authorized users.

Novel Polyphenols That Inhibit Colon Cancer Cell Growth Affecting Cancer Cell Metabolism

New series of polyphenols with a hydrophilic galloyl-based head and a hydrophobic N-acyl tail, linked through a serinol moiety, have been synthesized and tested against colon cancer cell growth. Our structure activity relationship studies revealed that galloyl moieties are essential for growth inhibition. Moreover, the length of the N-acyl chain is crucial for the activity. Introduction of a (Z) double bond in the acyl chain increased the anticancer properties. Our findings demonstrate that 16, the most potent compound within this series, has inhibitory effects on colon cancer cell growth and metabolism (glycolysis and mitochondrial respiration) at the same time that it activates 5'AMP-activated kinase (AMPK) and induces apoptotic cell death. Based on these results, we propose that 16 might reprogram colon cancer cell metabolism through AMPK activation. This might lead to alterations on cancer cell bioenergy compromising cancer cell viability. Importantly, these antiproliferative and proapoptotic effects are selective for cancer cells. Accordingly, these results indicate that 16, with an unsaturated C18 chain, might be a useful prototype for the development of novel colon cancer cell growth inhibitors affecting cell metabolism.

MicroRNA-661 modulates redox and metabolic homeostasis in colon cancer

Cancer cell survival and metastasis are dependent on metabolic reprogramming that is capable of increasing resistance to oxidative and energetic stress. Targeting these two processes can be crucial for cancer progression. Herein, we describe the role of microRNA‐661 (miR661) as epigenetic regulator of colon cancer (CC) cell metabolism. MicroR661 induces a global increase in reactive oxygen species, specifically in mitochondrial superoxide anions, which appears to be mediated by decreased carbohydrate metabolism and pentose phosphate pathway, and by a higher dependency on mitochondrial respiration. MicroR661 overexpression in non‐metastatic human CC cells induces an epithelial‐to‐mesenchymal transition phenotype, and a reduced tolerance to metabolic stress. This seems to be a general effect of miR661 in CC, since metastatic CC cell metabolism is also compromised upon miR661 overexpression. We propose hexose‐6‐phosphate dehydrogenase and pyruvate kinase M2 as two key players related to the observed metabolic reprogramming. Finally, the clinical relevance of miR661 expression levels in stage‐II and III CC patients is discussed. In conclusion, we propose miR661 as a potential modulator of redox and metabolic homeostasis in CC.

A link between lipid metabolism and epithelial-mesenchymal transition provides a target for colon cancer therapy

The alterations in carbohydrate metabolism that fuel tumor growth have been extensively studied. However, other metabolic pathways involved in malignant progression, demand further understanding. Here we describe a metabolic acyl-CoA synthetase/stearoyl-CoA desaturase ACSL/SCD network causing an epithelial-mesenchymal transition (EMT) program that promotes migration and invasion of colon cancer cells. The mesenchymal phenotype produced upon overexpression of these enzymes is reverted through reactivation of AMPK signaling. Furthermore, this network expression correlates with poorer clinical outcome of stage-II colon cancer patients. Finally, combined treatment with chemical inhibitors of ACSL/SCD selectively decreases cancer cell viability without reducing normal cells viability. Thus, ACSL/SCD network stimulates colon cancer progression through conferring increased energetic capacity and invasive and migratory properties to cancer cells, and might represent a new therapeutic opportunity for colon cancer treatment.

Microtargeting cancer metabolism: opening new therapeutic windows based on lipid metabolism

Metabolic reprogramming has emerged as a hallmark of cancer. MicroRNAs are noncoding RNAs that posttranscriptionally repress the expression of target mRNAs implicated in multiple physiological processes, including apoptosis, differentiation, and cancer. MicroRNAs can affect entire biological pathways, making them good candidates for therapeutic intervention compared with classical single target approaches. Moreover, microRNAs may become more relevant in the fine-tuning adaptation to stress situations, such as oncogenic events, hypoxia, nutrient deprivation, and oxidative stress. Furthermore, artificial microRNAs can be designed to modulate the expression of multiple targets of a specific pathway. In this review, we describe the metabolic reprogramming associated to cancer, with a special interest in the altered lipid metabolism. Next, we describe specific features of microRNAs that make them relevant to target cancer cell metabolism. Finally, in an attempt to open new therapeutic windows, we emphasize two exciting scenarios for microRNA-mediated intervention that need to be further explored: 1) the cooperation between FA biosynthesis (lipogenesis) and FA oxidation as complementary partners for the survival of cancer cells; and 2) the regulation of the intracellular lipid content modulating both lipid storage into lipid droplets, and lipid mobilization through lipolysis and/or lipophagy.

The ellagic acid derivative 4,4'-di-O-methylellagic acid efficiently inhibits colon cancer cell growth through a mechanism involving WNT16

Ellagic acid (EA) and some derivatives have been reported to inhibit cancer cell proliferation, induce cell cycle arrest, and modulate some important cellular processes related to cancer. This study aimed to identify possible structure-activity relationships of EA and some in vivo derivatives in their antiproliferative effect on both human colon cancer and normal cells, and to compare this activity with that of other polyphenols. Our results showed that 4,4'-di-O-methylellagic acid (4,4'-DiOMEA) was the most effective compound in the inhibition of colon cancer cell proliferation. 4,4'-DiOMEA was 13-fold more effective than other compounds of the same family. In addition, 4,4'-DiOMEA was very active against colon cancer cells resistant to the chemotherapeutic agent 5-fluoracil, whereas no effect was observed in nonmalignant colon cells. Moreover, no correlation between antiproliferative and antioxidant activities was found, further supporting that structure differences might result in dissimilar molecular targets involved in their differential effects. Finally, microarray analysis revealed that 4,4'-DiOMEA modulated Wnt signaling, which might be involved in the potential antitumor action of this compound. Our results suggest that structural-activity differences between EA and 4,4'-DiOMEA might constitute the basis for a new strategy in anticancer drug discovery based on these chemical modifications.

Genetic and epigenetic silencing of microRNA-203 enhances ABL1 and BCR-ABL1 oncogene expression

The mammalian genome contains several hundred microRNAs that regulate gene expression through modulation of target mRNAs. Here, we report a fragile chromosomal region lost in specific hematopoietic malignancies. This 7 Mb region encodes about 12% of all genomic microRNAs, including miR-203. This microRNA is additionally hypermethylated in several hematopoietic tumors, including chronic myelogenous leukemias and some acute lymphoblastic leukemias. A putative miR-203 target, ABL1, is specifically activated in these hematopoietic malignancies in some cases as a BCR-ABL1 fusion protein (Philadelphia chromosome). Re-expression of miR-203 reduces ABL1 and BCR-ABL1 fusion protein levels and inhibits tumor cell proliferation in an ABL1-dependent manner. Thus, miR-203 functions as a tumor suppressor, and re-expression of this microRNA might have therapeutic benefits in specific hematopoietic malignancies.

Genetic analysis of the function of the plum pox virus CI RNA helicase in virus movement

The CI protein forms the cylindrical inclusions typical of potyviral infections and is involved in genome replication and virus movement. In this work, we have analyzed the effect of a series of point mutations at the N-terminal region of the CI protein of Plum pox virus (PPV) on the enzymatic activities and the self-interaction ability of the protein, and on virus replication and movement. DD3,4AA mutation, which had no apparent effects on ATPase and RNA helicase activities in vitro, and on virus replication in protoplasts, drastically impaired cell-to-cell spread of the virus. The effect of KK101,102AA mutation was host-specific. While no signals of virus infection were detected in Chenopodium foetidum inoculated with PPV KK101,102AA, the mutation caused a moderate effect on short distance movement in Nicotiana benthamiana and N. clevelandii, which resulted in a more drastic disturbance of systemic spread. None of the mutations analyzed abolished PPV CI self-interaction in the yeast Two-Hybrid system, but they caused a notable reduction in the binding strength, which appears to positively correlate with their effect on virus movement, suggesting that CI-CI interactions required for RNA replication and virus movement could be rather different.