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Cyclophosphamide is a widely used anticancer and immunosuppressive prodrug that unfortunately causes severe adverse effects, including cardiotoxicity. Although the exact cardiotoxic mechanisms are not completely understood, a link between cyclophosphamide's pharmacologically active metabolites, namely 4-hydroxycyclophosphamide and acrolein, and the toxicity observed after the administration of high doses of the prodrug is likely. Therefore, the objective of this study is to shed light on the cardiotoxic mechanisms of cyclophosphamide and its main biotransformation products, through classic and metabolomics studies. Human cardiac proliferative and differentiated AC16 cells were exposed to several concentrations of the three compounds, determining their basic cytotoxic profile and preparing the next study, using subtoxic and toxic concentrations for morphological and biochemical studies. Finally, metabolomics studies were applied to cardiac cells exposed to subtoxic concentrations of the aforementioned compounds to determine early markers of damage. The cytotoxicity, morphological and biochemical assays showed that 4-hydroxycyclophosphamide and acrolein induced marked cardiotoxicity at µM concentrations (lower than 5 µM), being significantly lower than the ones observed for cyclophosphamide (higher than 2500 μM). Acrolein led to increased levels of ATP and total glutathione on proliferative cells at 25 µM, while no meaningful changes were observed in differentiated cells. Higher levels of carbohydrates and decreased levels of fatty acids and monoacylglycerols indicated a metabolic cardiac shift after exposure to cyclophosphamide's metabolites, as well as a compromise of precursor amino acids used in the synthesis of glutathione, seen in proliferative cells' metabolome. Overall, differences in cytotoxic mechanisms were observed for the two different cellular states used and for the three molecules, which should be taken into consideration in the study of cyclophosphamide cardiotoxic mechanisms. [ABSTRACT FROM AUTHOR]

Cognitive dysfunction has been one of the most reported and studied adverse effects of cancer treatment, but, for many years, it was overlooked by the medical community. Nevertheless, the medical and scientific communities have now recognized that the cognitive deficits caused by chemotherapy have a strong impact on the morbidity of cancer treated patients. In fact, chemotherapy-induced cognitive dysfunction or 'chemobrain' (also named also chemofog) is at present a well-recognized effect of chemotherapy that could affect up to 78% of treated patients. Nonetheless, its underlying neurotoxic mechanism is still not fully elucidated. Therefore, this work aimed to provide a comprehensive review using PubMed as a database to assess the studies published on the field and, therefore, highlight the clinical manifestations of chemobrain and the putative neurotoxicity mechanisms. In the last two decades, a great number of papers was published on the topic, mainly with clinical observations. Chemotherapy-treated patients showed that the cognitive domains most often impaired were verbal memory, psychomotor function, visual memory, visuospatial and verbal learning, memory function and attention. Chemotherapy alters the brain's metabolism, white and grey matter and functional connectivity of brain areas. Several mechanisms have been proposed to cause chemobrain but increase of proinflammatory cytokines with oxidative stress seem more relevant, not excluding the action on neurotransmission and cellular death or impaired hippocampal neurogenesis. The interplay between these mechanisms and susceptible factors makes the clinical management of chemobrain even more difficult. New studies, mainly referring to the underlying mechanisms of chemobrain and protective measures, are important in the future, as it is expected that chemobrain will have more clinical impact in the coming years, since the number of cancer survivors is steadily increasing. [ABSTRACT FROM AUTHOR]

Cathinone, the main psychoactive compound found in the plant Catha edulis Forsk. (khat), is a β-keto analogue of amphetamine, sharing not only the phenethylamine structure, but also the amphetamine-like stimulant effects. Synthetic cathinones are derivatives of the naturally occurring cathinone that largely entered the recreational drug market at the end of 2000s. The former "legal status", impressive marketing strategies and their commercial availability, either in the so-called "smartshops" or via the Internet, prompted their large spread, contributing to their increasing popularity in the following years. As their popularity increased, the risks posed for public health became clear, with several reports of intoxications and deaths involving these substances appearing both in the social media and scientific literature. The regulatory measures introduced thereafter to halt these trending drugs of abuse have proved to be of low impact, as a continuous emergence of new non-controlled derivatives keep appearing to replace those prohibited. Users resort to synthetic cathinones due to their psychostimulant properties but are often unaware of the dangers they may incur when using these substances. Therefore, studies aimed at unveiling the pharmacological and toxicological properties of these substances are imperative, as they will provide increased expertise to the clinicians that face this problem on a daily basis. The present work provides a comprehensive review on history and legal status, chemistry, pharmacokinetics, pharmacodynamics, adverse effects and lethality in humans, as well as on the current knowledge of the neurotoxic mechanisms of synthetic cathinones. [ABSTRACT FROM AUTHOR]

Synthetic cathinones are among the most popular new psychoactive substances, being abused for their stimulant properties, which are similar to those of amphetamine and 3,4-methylenedioxymethamphetamine (MDMA). Considering that the liver is a likely target for cathinones-induced toxicity, and for their metabolic activation/detoxification, we aimed to determine the hepatotoxicity of three commonly abused synthetic cathinones: butylone, α-methylamino-butyrophenone (buphedrone) and 3,4-dimethylmethcathinone (3,4-DMMC). We characterized their cytotoxic profile in primary rat hepatocytes (PRH) and in the HepaRG and HepG2 cell lines. PRH was the most sensitive cell model, showing the lowest EC50 values for all three substances (0.158 mM for 3,4-DMMC; 1.21 mM for butylone; 1.57 mM for buphedrone). Co-exposure of PRH to the synthetic cathinones and CYP450 inhibitors (selective and non-selective) proved that hepatic metabolism reduced the toxicity of buphedrone but increased that of butylone and 3,4-DMMC. All compounds were able to increase oxidative stress, disrupting mitochondrial homeostasis and inducing apoptotic and necrotic features, while also increasing the occurrence of acidic vesicular organelles in PRH, compatible with autophagic activation. In conclusion, butylone, buphedrone and 3,4-DMMC have hepatotoxic potential, and their toxicity lies in the interference with a number of homeostatic processes, while being influenced by their metabolic fate. [ABSTRACT FROM AUTHOR]

3,4-Methylenedioxypyrovalerone (MDPV) is consumed worldwide, despite its potential to cause toxicity in several organs and even death. There is a recognized need to clarify the biological pathways through which MDPV elicits general and target-organ toxicity. In this work, a comprehensive untargeted GC–MS-based metabolomics analysis was performed, aiming to detect metabolic changes in putative target organs (brain, heart, kidneys and liver) but also in urine of mice after acute exposure to human-relevant doses of MDPV. Male CD-1 mice received binge intraperitoneal administrations of saline or MDPV (2.5 mg/kg or 5 mg/kg) every 2 h, for a total of three injections. Twenty-four hours after the first administration, target organs, urine and blood samples were collected for metabolomics, biochemical and histological analysis. Hepatic and renal tissues of MDPV-treated mice showed moderate histopathological changes but no significant differences were found in plasma and tissue biochemical markers of organ injury. In contrast, the multivariate analysis significantly discriminated the organs and urine of MDPV-treated mice from the control (except for the lowest dose in the brain), allowing the identification of a panoply of metabolites. Those levels were significantly deviated in relation to physiological conditions and showed an organ specific response towards the drug. Kidneys and liver showed the greatest metabolic changes. Metabolites related with energetic metabolism, antioxidant defenses and inflammatory response were significantly changed in the liver of MDPV-dosed animals, while the kidneys seem to have developed an adaptive response against oxidative stress caused by MDPV. On the other hand, the dysregulation of metabolites that contribute to metabolic acidosis was also observed in this organ. The heart showed an increase of fatty acid biosynthesis, possibly as an adaptation to maintain the cardiac energy homeostasis. In the brain, changes in 3-hydroxybutyric acid levels may reflect the activation of a neurotoxic pathway. However, the increase in metabolites with neuroprotective properties seems to counteract this change. Metabolic profiling of urine from MDPV-treated mice suggested that glutathione-dependent antioxidant pathways may be particularly involved in the compensatory mechanism to counteract oxidative stress induced by MDPV. Overall, this study reports, for the first time, the metabolic profile of liver, kidneys, heart, brain, and urine of MDPV-dosed mice, providing unique insights into the biological pathways of toxicity. Our findings also underline the value of toxicometabolomics as a robust and sensitive tool for detecting adaptive/toxic cellular responses upon exposure to a physiologically relevant dose of a toxic agent, earlier than conventional toxicity tests. [ABSTRACT FROM AUTHOR]

Cathinones (β-keto amphetamines), widely abused in recreational settings, have been shown similar or even worse toxicological profile than classical amphetamines. In the present study, the cytotoxicity of two β-keto amphetamines [3,4-dimethylmethcathinone (3,4-DMMC) and 4-methylmethcathinone (4-MMC)], was evaluated in differentiated dopaminergic SH-SY5Y cells in comparison to methamphetamine (METH). MTT reduction and NR uptake assays revealed that both cathinones and METH induced cytotoxicity in a concentration- and time-dependent manner. Pre-treatment with trolox (antioxidant) partially prevented the cytotoxicity induced by all tested drugs, while N-acetyl-l-cysteine (NAC; antioxidant and glutathione precursor) and GBR 12909 (dopamine transporter inhibitor) partially prevented the cytotoxicity induced by cathinones, as evaluated by the MTT reduction assay. Unlike METH, cathinones induced oxidative stress evidenced by the increase on intracellular levels of reactive oxygen species (ROS), and also by the decrease of intracellular glutathione levels. Trolox prevented, partially but significantly, the ROS generation elicited by cathinones, while NAC inhibited it completely. All tested drugs induced mitochondrial dysfunction, since they led to mitochondrial membrane depolarization and to intracellular ATP depletion. Activation of caspase-3, indicative of apoptosis, was seen both for cathinones and METH, and confirmed by annexin V and propidium iodide positive staining. Autophagy was also activated by all drugs tested. Pre-incubation with bafilomycin A1, an inhibitor of the vacuolar H+-ATPase, only protected against the cytotoxicity induced by METH, which indicates dissimilar toxicological pathways for the tested drugs. In conclusion, the mitochondrial impairment and oxidative stress observed for the tested cathinones may be key factors for their neurotoxicity, but different outcome pathways seem to be involved in the adverse effects, when compared to METH. [ABSTRACT FROM AUTHOR]

Introduction: The inherent sensitivity of metabolomics allows the detection of subtle alterations in biological pathways, making it a powerful tool to study biomarkers and the mechanisms that underlie cancer. Objectives: The purpose of this work was to characterize the urinary metabolic profile of prostate cancer (PCa) patients and cancer-free controls to obtain a holistic coverage of PCa metabolome. Methods: Two groups of samples, a training set (n = 41 PCa and n = 42 controls) and an external validation set (n = 18 PCa and n = 18 controls) were analyzed using a dual analytical platform, namely gas chromatography-mass spectrometry (GC–MS) and proton nuclear magnetic resonance spectroscopy (1H NMR). Results: The multivariate analysis models revealed a good discrimination between cases and controls with an AUC higher than 0.8, a sensitivity ranging from 67 to 89%, a specificity ranging from 74 to 89% and an accuracy from 73 to 86%, considering the training and external validation sets. A total of 28 metabolites (15 from GC–MS and 13 from 1H NMR) accounted for the separation. These discriminant metabolites are involved in 14 biochemical pathways, indicating that PCa is highly linked to dysregulation of metabolic pathways associated with amino acids and energetic metabolism. Conclusion: These findings confirmed the complementary information provided by GC–MS and 1H NMR, enabling a more comprehensive picture of the altered metabolites, underlying pathways and deepening the understanding of PCa development and progression. [ABSTRACT FROM AUTHOR]

During the last decades, we have witnessed unparalleled changes in human eating habits and lifestyle, intensely influenced by cultural and social pressures. Sports practice became strongly implemented in daily routines, and visits to the gym peaked, driven by the indulgence in intensive 'weight-loss programs'. The pledge of boasting a healthy and beautiful body instigates the use of very attractive 'fat burners', which are purportedly advertised as safe products, easily available in the market and expected to quickly reduce body weight. In this context, the slimming properties of 2,4-dinitrophenol (2,4-DNP) galvanised its use as a weight-loss product, despite the drug ban for human consumption in many countries since 1938, due to its adverse effects. The main symptoms associated with 2,4-DNP intoxication, including hyperthermia, tachycardia, decreased blood pressure, and acute renal failure, motivated a worldwide warning, issued by the Interpol Anti-Doping Unit in 2015, reinforcing its hazard. Information on the effects of 2,4-DNP mainly derive from the intoxication cases reported by emergency care units, for which there is no specific antidote or treatment. This review provides a comprehensive update on 2,4-DNP use, legislation and epidemiology, chemistry and analytical methodologies for drug determination in commercial products and biological samples, pharmacokinetics and pharmacodynamics, toxicological effects, and intoxication diagnosis and management. [ABSTRACT FROM AUTHOR]

New phenylethylamine derivatives are among the most commonly abused new psychoactive substances. They are synthesized and marketed in lieu of classical amphetaminic stimulants, with no previous safety testing. Our study aimed to determine the in vitro hepatotoxicity of two benzofurans [6-(2-aminopropyl)benzofuran (6-APB) and 5-(2-aminopropyl)benzofuran (5-APB)] that have been misused as 'legal highs'. Cellular viability was assessed through the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay, following 24-h drug exposure of human hepatoma HepaRG cells (EC50 2.62 mM 5-APB; 6.02 mM 6-APB), HepG2 cells (EC50 3.79 mM 5-APB; 8.18 mM 6-APB) and primary rat hepatocytes (EC50 964 μM 5-APB; 1.94 mM 6-APB). Co-incubation of primary hepatocytes, the most sensitive in vitro model, with CYP450 inhibitors revealed a role of metabolism, in particular by CYP3A4, in the toxic effects of both benzofurans. Also, 6-APB and 5-APB concentration-dependently enhanced oxidative stress (significantly increased reactive species and oxidized glutathione, and decreased reduced glutathione levels) and unsettled mitochondrial homeostasis, with disruption of mitochondrial membrane potential and decline of intracellular ATP. Evaluation of cell death mechanisms showed increased caspase-8, -9, and -3 activation, and nuclear morphological changes consistent with apoptosis; at concentrations higher than 2 mM, however, necrosis prevailed. Concentration-dependent formation of acidic vesicular organelles typical of autophagy was also observed for both drugs. Overall, 5-APB displayed higher hepatotoxicity than its 6-isomer. Our findings provide new insights into the potential hepatotoxicity of these so-called 'safe drugs' and highlight the putative risks associated with their use as psychostimulants. Key points: The isomer 5-APB is more hepatotoxic than 6-APB. At biologically relevant concentrations, CYP2D6 and 3A4 contribute to the toxification of psychoactive 5-APB and 6-APB. CYP2E1 seems also implicated in 5-APB bioactivation. Both benzofury concentration-dependently increase oxidative species, disturb mitochondrial potential homeostasis and energetic levels. 5-APB and 6-APB stimulate autophagy and apoptosis at low in vitro concentrations. [ABSTRACT FROM AUTHOR]

Purpose: To provide a review of the available data on 3,4-dimethylmethcathinone (3,4-DMMC), its physicochemical properties, detection methods, patterns of abuse and prevalence, biological effects, pharmacodynamics, pharmacokinetics, metabolism, and mechanisms of toxicity have been presented and discussed. Methods: An exhaustive literature search was carried out with PubMed, drug use forums and blogs, and sites from governmental agencies. Results: 3,4-DMMC is a synthetic cathinone that was first detected in Europe in 2010. Its recreational use and trade in retail outlets have been prohibited in several countries, but the drug remains readily available for purchase on the Internet. 3,4-DMMC has been considered a very appealing drug to be used in combination with other abuse substances. The drug combines the features of stimulants and psychoactive phenethylamines, displays high affinity for 5-HT2 and adrenergic receptors, inhibits monoamine transporters, specially serotonin transporter, but does not promote a significant 5-HT efflux. Recently, anecdotal reports on its abuse sprang up, and 3,4-DMMC has been detected in several seized products and in blood and urine of abusers. 3,4-DMMC metabolites in the urine of habitual users showed N-demethylation, β-ketoreduction, hydroxylation, and oxidation as the major reactions involved in its biotransformation. Conclusions: There is a wide scope to be explored on the effects of 3,4-DMMC. Clinicians and pathologists should be encouraged to report their findings in scientific literature, as this will aid in evaluating potential detrimental effects of the drug in further clinical and forensic investigations. Further studies on pharmacokinetic properties of 3,4-DMMC are also necessary to improve the methods of drug detection. [ABSTRACT FROM AUTHOR]

Methylone (3,4-methylenedioxymethcathinone) is one of the most popular new psychoactive drugs worldwide. Although advertised as a safe drug, its use has been associated to several cases of liver damage. In this work, a metabolomics approach based on gas chromatography–mass spectrometry (GC–MS) combined with chemometric analyses was used to characterize the disturbances occurring in the intra- and extracellular metabolome of primary mouse hepatocytes exposed to two subtoxic concentrations (LC01 and LC10) of methylone to better understand the early hepatotoxic events. Results showed a characteristic metabolic fingerprint for methylone, where aspartate, cysteine, 2-methyl-1-pentanol, 4-methylheptane, dodecane, 2,4-dimethyl-1-heptene, 1,3-di-tert-butylbenzene, acetophenone, formaldehyde and glyoxal levels were significantly changed at both concentrations tested. Furthermore, subtoxic concentrations of methylone caused profound changes in several biochemical pathways, suggesting adaptations in energy production processes (TCA cycle, amino acids metabolism and pyruvate metabolism), cellular antioxidant defenses (glutamate, cysteine and glutathione metabolism) and hepatic enzymes (associated to hydrocarbons, alcohols, aldehydes and ketones metabolism). This metabolic response to the initial methylone challenge most probably reflects the activation of protective mechanisms to restore cellular homeostasis. Overall, this study highlights the potential of untargeted metabolomic analysis to reveal the hepatic metabolic signature of methylone at subtoxic concentrations, and also provides clues to clarify the early mechanisms underlying the toxicity triggered by this new psychoactive substance, opening a new perspective for the study of toxicity mechanisms of new xenobiotics. [ABSTRACT FROM AUTHOR]

3-Methylmethcathinone (3-MMC or metaphedrone) has become one of the most popular recreational drugs worldwide after the ban of mephedrone, and was recently deemed responsible for several intoxications and deaths. This study aimed at assessing the hepatotoxicity of 3-MMC. For this purpose, Wistar rat hepatocytes were isolated by collagenase perfusion, cultured and exposed for 24 h at a concentration range varying from 31 nM to 10 mM 3-MMC. The modulatory effects of cytochrome P450 (CYP) inhibitors on 3-MMC hepatotoxicity were evaluated. 3-MMC-induced toxicity was perceived at the lysosome at lower concentrations (NOEC 312.5 µM), compared to mitochondria (NOEC 379.5 µM) and cytoplasmic membrane (NOEC 1.04 mM). Inhibition of CYP2D6 and CYP2E1 diminished 3-MMC cytotoxicity, yet for CYP2E1 inhibition this effect was only observed for concentrations up to 1.3 mM. A significant concentration-dependent increase of intracellular reactive species was observed from 10 μM 3-MMC on; a concentration-dependent decrease in antioxidant glutathione defences was also observed. At 10 μM, caspase-3, caspase-8, and caspase-9 activities were significantly elevated, corroborating the activation of both intrinsic and extrinsic apoptosis pathways. Nuclear morphology and formation of cytoplasmic acidic vacuoles suggest prevalence of necrosis and autophagy at concentrations higher than 10 μM. No significant alterations were observed in the mitochondrial membrane potential, but intracellular ATP significantly decreased at 100 μM. Our data point to a role of metabolism in the hepatotoxicity of 3-MMC, which seems to be triggered both by autophagic and apoptotic/necrotic mechanisms. This work is the first approach to better understand 3-MMC toxicology. [ABSTRACT FROM AUTHOR]

Cocaine (COC) is frequently consumed in polydrug abuse settings, and ethanol (EtOH) is the most prominent co-abused substance. Clinical data and experimental evidence suggest that the co-administration of COC with EtOH can be more cardiotoxic than EtOH or COC alone, but information on the molecular pathways involved is scarce. Since these data are crucial to potentiate the identification of therapeutic targets to treat intoxications, we sought to (i) elucidate the type of interaction that occurs between both substances, and (ii) assess the mechanisms implicated in the cardiotoxic effects elicited by COC combined with EtOH. For this purpose, H9c2 cardiomyocytes were exposed to COC (104 µM-6.5 mM) and EtOH (977 µM-4 M), individually or combined at a molar ratio based on blood concentrations of intoxicated abusers (COC 1: EtOH 9; 206 µM-110 mM). After 24 h, cell metabolic viability was recorded by the MTT assay and mixture toxicity expectations were calculated using the independent action (IA) and concentration addition (CA) models. EtOH (EC50 305.26 mM) proved to act additively with COC (EC50 2.60 mM) to significantly increase the drug in vitro cardiotoxicity, even when both substances were combined at individually non-cytotoxic concentrations. Experimental mixture testing (EC50 19.18 ± 3.36 mM) demonstrated that the cardiotoxicity was fairly similar to that predicted by IA (EC50 22.95 mM) and CA (EC50 21.75 mM), supporting additivity. Concentration-dependent increases of intracellular ROS/RNS and GSSG, depletion of GSH and ATP, along with mitochondrial hyperpolarization and activation of intrinsic, extrinsic, and common apoptosis pathways were observed both for single and combined exposures. In general, the mixture exhibited a toxicological profile that mechanistically did not deviate from the single drugs, suggesting that interventions such as antioxidant administration might aid in the clinical treatment of this type of polydrug intoxication. In a clinical perspective, the observed additive mixture effect may reflect the increased hazards at which users of this combination are exposed to in recreational settings. [ABSTRACT FROM AUTHOR]

2-Styrylchromones are a novel class of chromones, vinylogues of flavones (2-phenylchromones), which have recently been found in nature. The best described property of almost every group of flavones and other flavonoids, especially the hydroxylated derivatives, is their capacity to act as antioxidants. Indeed there is a widely accepted view that the positive health effects of flavones are due to their antioxidant activity. As oxidative stress is a main cause of liver toxicity induced by several hepatotoxicants, agents with the ability to protect the liver against reactive pro-oxidant species may be therapeutically useful. The present study evaluated the possible protective activity of six new synthetic polyhydroxylated 2-styrylchromone derivatives against the pro-oxidant hepatotoxicity exerted by tert-butylhydroperoxide (t-BHP) in freshly isolated rat hepatocytes. The cells were preincubated with the 2-styrylchromones in the final concentrations of 3.125, 12.5, 25, 50, 100, and 200 µM for 5 min before treatment with 1.0 mM t-BHP for 30 min (throughout this incubation period the cells were exposed to both compounds). The well-known antioxidant 3-hydroxyflavone (quercetin) was used as positive control. At the end of the 30-min incubation period, aliquots of cells suspensions were taken for measurement of lactate dehydrogenase leakage, thiobarbituric acid reactive substances, reduced glutathione, and oxidized glutathione contents. The tested compounds exhibited in vitro protective activity against t-BHP induced hepatotoxicity (1.0 mM, 30 min). Three of the tested compounds, at the concentrations of 3.125, 12.5, 25, and 50 µM, prevented the t-BHP induced glutathione depletion, lipid peroxidation, and cell death in freshly isolated rat hepatocytes to a comparable potency with that of quercetin. [ABSTRACT FROM AUTHOR]

Introduction: Prostate cancer (PCa) is one of the most prevalent cancers in men worldwide. Serum prostate-specific antigen (PSA) remains the most used biomarker in the detection and management of patients with PCa, in spite of the problems related with its low specificity, false positive rate and overdiagnosis. Furthermore, PSA is unable to discriminate indolent from aggressive PCa, which can lead to overtreatment. Early diagnosed and treated PCa can have a good prognosis and is potentially curable. Therefore, the discovery of new biomarkers able to detect clinically significant aggressive PCa is urgently needed.Methods: This revision was based on an electronic literature search, using Pubmed, with Nuclear Magnetic Resonance (NMR), tissue and prostate cancer as keywords. All metabolomic studies performed in PCa tissues by NMR spectroscopy, from 2007 until March 2018, were included in this review.Results: In the context of cancer, metabolomics allows the analysis of the entire metabolic profile of cancer cells. Several metabolic alterations occur in cancer cells to sustain their abnormal rates of proliferation. NMR proved to be a suitable methodology for the evaluation of these metabolic alterations in PCa tissues, allowing to unveil alterations in citrate, spermine, choline, choline-related compounds, lactate, alanine and glutamate.Conclusion: The study of the metabolic alterations associated with PCa progression, accomplished by the analysis of PCa tissue by NMR, offers a promising approach for elucidating biochemical pathways affected by PCa and also for discovering new clinical biomarkers. The main metabolomic alterations associated with PCa development and promising biomarker metabolites for diagnosis of PCa were outlined. [ABSTRACT FROM AUTHOR]

RCC usually develops and progresses asymptomatically and, when detected, it is frequently at advanced stages and metastatic, entailing a dismal prognosis. Therefore, there is an obvious demand for new strategies enabling an earlier diagnosis. The importance of metabolic rearrangements for carcinogenesis unlocked a new approach for cancer research, catalyzing the increased use of metabolomics. The present study aimed the NMR metabolic profiling of RCC in urine samples from a cohort of RCC patients (n = 42) and controls (n = 49). The methodology entailed variable selection of the spectra in tandem with multivariate analysis and validation procedures. The retrieval of a disease signature was preceded by a systematic evaluation of the impacts of subject age, gender, BMI, and smoking habits. The impact of confounders on the urine metabolomics profile of this population is residual compared to that of RCC. A 32-metabolite/resonance signature descriptive of RCC was unveiled, successfully distinguishing RCC patients from controls in principal component analysis. This work demonstrates the value of a systematic metabolomics workflow for the identification of robust urinary metabolic biomarkers of RCC. Future studies should entail the validation of the 32-metabolite/resonance signature found for RCC in independent cohorts, as well as biological validation of the putative hypotheses advanced. [ABSTRACT FROM AUTHOR]