Biomarkers for Early Detection of Cancer: Molecular Aspects.

According to the World Health Organization, cancer is a leading cause of death worldwide, representing almost 10 million deaths in 2020 [...].

Upregulation of Phospholipase C Gene Expression Due to Norepinephrine-Induced Hypertrophic Response.

The activation of phospholipase C (PLC) is thought to have a key role in the cardiomyocyte response to several different hypertrophic agents such as norepinephrine, angiotensin II and endothelin-1. PLC activity results in the generation of diacylglycerol and inositol trisphosphate, which are downstream signal transducers for the expression of fetal genes, increased protein synthesis, and subsequent cardiomyocyte growth. In this article, we describe the signal transduction elements that regulate PLC gene expression. The discussion is focused on the norepinephrine- α1-adrenoceptor signaling pathway and downstream signaling processes that mediate an upregulation of PLC isozyme gene expression. Evidence is also indicated to demonstrate that PLC activities self-regulate the expression of PLC isozymes with the suggestion that PLC activities may be part of a coordinated signaling process for the perpetuation of cardiac hypertrophy. Accordingly, from the information provided, it is plausible that specific PLC isozymes could be targeted for the mitigation of cardiac hypertrophy.

Role of phospholipase C in catecholamine-induced increase in myocardial protein synthesis.

The activation of the α1-adrenoceptor-(α1-AR) by norepinephrine results in the G-protein (Gqα) mediated increase in the phosphoinositide-specific phospholipase C (PLC) activity. The byproducts of PLC hydrolytic activity, namely, 1,2-diacylglycerol and inositol-1,4,5-trisphosphate, are important downstream signal transducers for increased protein synthesis in the cardiomyocyte and the subsequent hypertrophic response. In this article, evidence was outlined to demonstrate the role of cardiomyocyte PLC isozymes in the catecholamine-induced increase in protein synthesis by using a blocker of α1-AR and an inhibitor of PLC. The discussion was focused on the α1-AR-Gqα-PLC-mediated hypertrophic signalling pathway from the viewpoint that it may compliment the other ß1-AR-Gs protein-adenylyl cyclase signal transduction mechanisms in the early stages of cardiac hypertrophy development, but may become more relevant at the late stage of cardiac hypertrophy. From the information provided here, it is suggested that some specific PLC isozymes may potentially serve as important targets for the attenuation of cardiac hypertrophy in the vulnerable patient population at-risk for heart failure.

Modification of Ischemia/Reperfusion-Induced Alterations in Subcellular Organelles by Ischemic Preconditioning.

It is now well established that ischemia/reperfusion (I/R) injury is associated with the compromised recovery of cardiac contractile function. Such an adverse effect of I/R injury in the heart is attributed to the development of oxidative stress and intracellular Ca2+-overload, which are known to induce remodeling of subcellular organelles such as sarcolemma, sarcoplasmic reticulum, mitochondria and myofibrils. However, repeated episodes of brief periods of ischemia followed by reperfusion or ischemic preconditioning (IP) have been shown to improve cardiac function and exert cardioprotective actions against the adverse effects of prolonged I/R injury. This protective action of IP in attenuating myocardial damage and subcellular remodeling is likely to be due to marked reductions in the occurrence of oxidative stress and intracellular Ca2+-overload in cardiomyocytes. In addition, the beneficial actions of IP have been attributed to the depression of proteolytic activities and inflammatory levels of cytokines as well as the activation of the nuclear factor erythroid factor 2-mediated signal transduction pathway. Accordingly, this review is intended to describe some of the changes in subcellular organelles, which are induced in cardiomyocytes by I/R for the occurrence of oxidative stress and intracellular Ca2+-overload and highlight some of the mechanisms for explaining the cardioprotective effects of IP.

Metabolomic Fingerprinting for the Detection of Early-Stage Lung Cancer: From the Genome to the Metabolome.

The five-year survival rate of lung cancer patients is very low, mainly because most newly diagnosed patients present with locally advanced or metastatic disease. Therefore, early diagnosis is key to the successful treatment and management of lung cancer. Unfortunately, early detection methods of lung cancer are not ideal. In this brief review, we described early detection methods such as chest X-rays followed by bronchoscopy, sputum analysis followed by cytological analysis, and low-dose computed tomography (LDCT). In addition, we discussed the potential of metabolomic fingerprinting, compared to that of other biomarkers, including molecular targets, as a low-cost, high-throughput blood-based test that is both feasible and affordable for early-stage lung cancer screening of at-risk populations. Accordingly, we proposed a paradigm shift to metabolomics as an alternative to molecular and proteomic-based markers in lung cancer screening, which will enable blood-based routine testing and be accessible to those patients at the highest risk for lung cancer.

Use of amantadine in the evaluation of response to chemotherapy in lung cancer: a pilot study.

AIM: The assessment of tumor response to therapy is of critical importance as it permits for a prospective end point evaluation and provides a guide to clinicians for making future treatment decisions. However, current practices in early evaluation of chemotherapy are insufficient. Amantadine is a substrate for SSAT-1. The present pilot study tests the hypothesis that SSAT-1 activity within the tumor, as measured by plasma acetylamantadine concentrations, can be used to monitor patient response to therapy. RESULTS: In cases with evidence of disease response, there was a reduction in the plasma acetylamantadine concentration at 4 h by approximately 32%. There was a mean increase of approximately 34% at the 4 h collection in the nonresponders. CONCLUSION: Although large-scale studies are required these findings suggest that the amantadine test could allow for determination of the efficacy of therapeutic interventions earlier, providing an effective test to assess response to treatment and for better management of patients.

Nutrition and Cardiovascular Health.

There is unequivocal experimental, epidemiological and clinical evidence demonstrating a correlation between diet and increased risk of cardiovascular disease (CVD) [...].

Role of Oxidative Stress in Metabolic and Subcellular Abnormalities in Diabetic Cardiomyopathy.

Although the presence of cardiac dysfunction and cardiomyopathy in chronic diabetes has been recognized, the pathophysiology of diabetes-induced metabolic and subcellular changes as well as the therapeutic approaches for the prevention of diabetic cardiomyopathy are not fully understood. Cardiac dysfunction in chronic diabetes has been shown to be associated with Ca2+-handling abnormalities, increase in the availability of intracellular free Ca2+ and impaired sensitivity of myofibrils to Ca2+. Metabolic derangements, including depressed high-energy phosphate stores due to insulin deficiency or insulin resistance, as well as hormone imbalance and ultrastructural alterations, are also known to occur in the diabetic heart. It is pointed out that the activation of the sympathetic nervous system and renin-angiotensin system generates oxidative stress, which produces defects in subcellular organelles including sarcolemma, sarcoplasmic reticulum and myofibrils. Such subcellular remodeling plays a critical role in the pathogenesis of diabetic cardiomyopathy. In fact, blockade of the effects of neurohormonal systems has been observed to attenuate oxidative stress and occurrence of subcellular remodeling as well as metabolic abnormalities in the diabetic heart. This review is intended to describe some of the subcellular and metabolic changes that result in cardiac dysfunction in chronic diabetes. In addition, the therapeutic values of some pharmacological, metabolic and antioxidant interventions will be discussed. It is proposed that a combination therapy employing some metabolic agents or antioxidants with insulin may constitute an efficacious approach for the prevention of diabetic cardiomyopathy.

A High-Performing Plasma Metabolite Panel for Early-Stage Lung Cancer Detection.

The objective of this research is to use metabolomic techniques to discover and validate plasma metabolite biomarkers for the diagnosis of early-stage non-small cell lung cancer (NSCLC). The study included plasma samples from 156 patients with biopsy-confirmed NSCLC along with age and gender-matched plasma samples from 60 healthy controls. A fully quantitative targeted mass spectrometry (MS) analysis (targeting 138 metabolites) was performed on all samples. The sample set was split into a discovery set and validation set. Metabolite concentration data, clinical data, and smoking history were used to determine optimal sets of biomarkers and optimal regression models for identifying different stages of NSCLC using the discovery sets. The same biomarkers and regression models were used and assessed on the validation models. Univariate and multivariate statistical analysis identified ß-hydroxybutyric acid, LysoPC 20:3, PC ae C40:6, citric acid, and fumaric acid as being significantly different between healthy controls and stage I/II NSCLC. Robust predictive models with areas under the curve (AUC) > 0.9 were developed and validated using these metabolites and other, easily measured clinical data for detecting different stages of NSCLC. This study successfully identified and validated a simple, high-performing, metabolite-based test for detecting early stage (I/II) NSCLC patients in plasma. While promising, further validation on larger and more diverse cohorts is still required.

Liquid Biopsy in Lung Cancer Screening: The Contribution of Metabolomics. Results of A Pilot Study.

Background: Lung cancer is the most common cause of cancer-related deaths worldwide. Early diagnosis is crucial to increase the curability chance of the patients. Low dose CT screening can reduce lung cancer mortality, but it is associated with several limitations. Metabolomics is a promising technique for cancer diagnosis due to its ability to provide chemical phenotyping data. The intent of our study was to explore metabolomic effects and profiles of lung cancer patients to determine if metabolic perturbations in the SSAT-1/polyamine pathway can distinguish between healthy participants and lung cancer patients as a diagnostic and treatment monitoring tool. Patients and Methods: Plasma samples were collected as part of the SSAT1 Amantadine Cancer Study. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to identify and quantify metabolite concentrations in lung cancer patient and control samples. Standard statistical analyses were performed to determine whether metabolite concentrations could differentiate between healthy subjects and lung cancer patients, as well as risk prediction modeling applied to determine whether metabolic profiles could provide an indication of cancer progression in later stage patients. Results: A panel consisting of 14 metabolites, which included 6 metabolites in the polyamine pathway, was identified that correctly discriminated lung cancer patients from controls with an area under the curve of 0.97 (95% CI: 0.875-1.0). Conclusion: When used in conjunction with the SSAT-1/polyamine pathway, these metabolites may provide the specificity required for diagnosing lung cancer from other cancer types and could be used as a diagnostic and treatment monitoring tool.

Predictive value and clinical significance of increased SSAT-1 activity in healthy adults.

AIM: Spermidine/spermine N1-acetyltransferase (SSAT-1) regulates cell growth, proliferation and death. Amantadine is converted by SSAT-1 to acetylamantadine (AA). In our earlier studies, although SSAT-1 was activated in patients with cancer, a number of ostensibly healthy adult volunteers had higher than expected AA concentration. This study was therefore undertaken to examine the outlier group. MATERIALS & METHODS: A follow up of urine analysis for AA by liquid chromatography-tandem mass spectrometry as well as clinical assessments and additional blood analyses were conducted. RESULTS: In some of the outlier controls, higher than expected AA concentration was linked to increased serum carcinoembryonic antigen. Clinical and radiographic assessments revealed underlying abnormalities in other cases that could represent premalignant conditions. Hematology tests revealed elevations in white blood cells and platelets, which are markers of inflammation. CONCLUSION: High urine concentration of AA could be used as a simple and useful test for screening of cancer in high-risk populations.

Role of catecholamines in the pathogenesis of diabetic cardiomyopathy 1.

Although the sympathetic nervous system plays an important role in the regulation of cardiac function, the overactivation of the sympathetic nervous system under stressful conditions including diabetes has been shown to result in the excessive production of circulating catecholamines as well as an increase in the myocardial concentration of catecholamines. In this brief review, we provide some evidence to suggest that the oxidation products of catecholamines such as aminochrome and oxyradicals, lead to metabolic derangements, Ca2+-handling abnormalities, increase in the availability of intracellular free Ca2+, as well as activation of proteases and changes in myocardial gene expression. These alterations due to elevated levels of circulatory catecholamines are associated with oxidative stress, subcellular remodeling, and the development of cardiac dysfunction in chronic diabetes.

Ginseng Berry Extract Rich in Phenolic Compounds Attenuates Oxidative Stress but not Cardiac Remodeling post Myocardial Infarction.

The cardioprotective effects of ginseng root extracts have been reported. However, nothing is known about the myocardial actions of the phenolic compounds enriched in ginseng berry. Therefore, this study was undertaken to investigate the effects of American ginseng berry extract (GBE) in an experimental model of myocardial infarction (MI). Coronary artery ligation was performed on Sprague⁻Dawley male rats to induce MI after which animals were randomized into groups receiving either distilled water or GBE intragastrically for 8 weeks. Echocardiography and assays for malondialdehyde (MDA) and TNF-α were conducted. Flow cytometry was used to test the effects of GBE on T cell phenotypes and cytokine production. Although GBE did not improve the cardiac functional parameters, it significantly attenuated oxidative stress in post-MI rat hearts. GBE treatment also resulted in lower than control levels of TNF-α in post-MI rat hearts indicating a strong neutralizing effect of GBE on this cytokine. However, there was no effect of GBE on the proportion of different T cell subsets or ex-vivo cytokine production. Taken together, the present study demonstrates GBE reduces oxidative stress, however no effect on cardiac structure and function in post-MI rats. Moreover, reduction of TNF-α levels below baseline raises concern regarding its use as prophylactic or preventive adjunct therapy in cardiovascular disease.

Use of amantadine as substrate for SSAT-1 activity as a reliable clinical diagnostic assay for breast and lung cancer.

AIM: Spermidine/spermine N1-acetyltransferase (SSAT-1) plays a critical role in cell growth, proliferation and death, and is known to be activated in human cancer cells. Amantadine, a US FDA-approved antiviral drug, is a substrate for SSAT-1 and can be used to indirectly measure SSAT-1 activity because of its conversion to acetylamantadine (AA). This study was undertaken to further validate SSAT-1 activity in breast and lung cancer patients. RESULTS: An increase in the urinary concentration of AA in lung and breast cancer patients was observed. The 0-2 h collection time point was determined to be optimal in revealing significant differences in urinary AA concentration between healthy controls and cancer patients. CONCLUSION: The high urine concentration of AA could be used as a simple and useful test for the detection of breast and lung cancer.

Developmental origins of myocardial abnormalities in postnatal life 1.

Poor quality and quantity maternal nutrition during pregnancy exerts permanent and damaging effects on the heart of the developing fetus. The developmental origin of adult heart disease is considered an important and critical factor in the pathogenesis of myocardial abnormalities in later life. Low birth mass, a marker of intrauterine stress, has been linked to a predisposition to heart disease. In this article, our work on the impact of exposure to a low-protein diet, in utero, on the developing heart and its long-term consequences are discussed. Other studies providing some supportive evidence are also described. It is proposed that normal fetal nutrition, growth, and development through efficient maternal nutrition (as well as other predisposing factors) before and during pregnancy may serve as a strategy for the primary prevention of heart disease.

Modification of gene expression in rat cardiomyocytes by linoleic and docosahexaenoic acids 1.

Regulation of cardiac fatty acid metabolism is central to the development of cardiac hypertrophy and heart failure. We investigated the effects of select fatty acids on the expression of genes involved in immediate early as well as inflammatory and hypertrophic responses in adult rat cardiomyocytes. Cardiac remodeling begins with upregulation of immediate early genes for c-fos and c-jun, followed by upregulation of inflammatory genes for nuclear factor kappa B (NF-κB) and nuclear factor of activated T-cells (NFAT). At later stages, genes involved in hypertrophic responses, such as atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), are upregulated. Adult rat cardiomyocytes were treated with palmitic acid, a saturated fatty acid; oleic acid, a monounsaturated fatty acid; linoleic acid, a polyunsaturated fatty acid belonging to the n-6 class; and docosahexaenoic acid, a polyunsaturated fatty acid belonging to the n-3 class. Linoleic acid produced a greater increase in the mRNA expression of c-fos, c-jun, NF-κB, NFAT3, ANP, and BNP relative to palmitic acid and oleic acid. In contrast, docosahexaenoic acid caused a decrease in the expression of genes involved in cardiac hypertrophy. Our findings suggest that linoleic acid may be a potent inducer of genes involved in cardiac hypertrophy, whereas docosahexaenoic acid may be protective against the cardiomyocyte hypertrophic response.

Spermidine/spermine N1-acetyltransferase-1 as a diagnostic biomarker in human cancer.

AIM: SSAT-1 is an enzyme that plays a critical role in cell growth. Amantadine, a FDA-approved antiviral drug, is a substrate for SSAT-1. The utility of amantadine as an agent to demonstrate elevated SSAT-1 activity linked to cancer was conducted. RESULTS: High levels of SSAT-1 expression were measured in tumor human cell lines, and in breast, prostate and lung tumor tissue. An increase in the urinary levels of acetylated amantadine in cancer patients was observed. CONCLUSION: Increases in SSAT-1 contents in tumor tissue could be of value in targeting cancers with high SSAT-1 expression for confirmation/quantification. The high levels of acetylated amantadine could be used as a simple and useful screening test for the presence of cancer.

A randomized trial to determine the impact of a digestion resistant starch composition on the gut microbiome in older and mid-age adults.

BACKGROUND: The elderly often have a diet lacking resistant starch (RS) which is thought to lead to gut microbiome dysbiosis that may result in deterioration of gut colonocytes. OBJECTIVE: The primary objective was to assess if elderly (ELD; ≥ 70 years age) had microbiome dysbiosis compared to mid-age (MID; 30-50 years age) adults and then determine the impact of daily consumption of MSPrebiotic® (a RS) or placebo over 3 months on gut microbiome composition. Secondary objectives included assessment of stool short-chain fatty acids (SCFA) and inflammatory markers in ELD and MID Canadian adults. DESIGN: This was a prospective, placebo controlled, randomized, double-blinded study. Stool was collected at enrollment and 6, 10 and 14 weeks after randomization to placebo or MSPrebiotic®. Microbiome analysis was done using 16S rRNA sequencing of DNA extracted from stool. SCFA analysis of stool was performed using gas chromatography. RESULTS: There were 42 ELD and 42 MID participants randomized to either placebo or MSPrebiotic® who completed the study. There was significantly higher abundance of Proteobacteria (Escherichia coli/Shigella) in ELD compared to MID at enrollment (p < 0.001) that was not observed after 12 weeks of MSPrebiotic® consumption. There was a significant increase in Bifidobacterium in both ELD and MID compared to placebo (p = 0.047 and 0.006, respectively). There was a small but significant increase in the stool SCFA butyrate levels in the ELD on MSPrebiotic® versus placebo. CONCLUSIONS: The study data demonstrated that MSPrebiotic® meets the criteria of a prebiotic and can stimulate an increased abundance of endogenous Bifidobacteria in both ELD and MID without additional probiotic supplementation. MSPrebiotic® consumption also eliminated the dysbiosis of gut Proteobacteria observed in ELD at baseline. CLINICAL TRIAL REGISTRY NUMBER: NCT01977183 listed on NIH website: ClinicalTrials.gov. The full trial protocol is available on request from the corresponding author. NUCLEOTIDE SEQUENCE ACCESSION NUMBERS: The 16S rRNA sequencing data and metadata generated in this study have been submitted to the NCBI Sequence Read Archive (SRA: http://www.ncbi.nlm.nih.gov/bioproject/381931).

Potential of Sulphur-containing Amino Acids in the Prevention of Catecholamine-induced Arrhythmias.

BACKGROUND: Various physiological and pathological stimuli can hypersensitize the sympathetic nervous system resulting in a substantial release of catecholamines (CA) and consequent alterations in excitation-contraction coupling and excitation-transcription coupling. OBSERVATIONS: It has been shown that oxidation products of CA, rather than CA themselves, are responsible for such adaptation to a new equilibrium. While chronic, sustained accumulation of CA and their toxic products are associated with the depression in cardiac contractile force and remodeling, acute excessive release of CA can result in brief oxidative bursts and serious damage leading in lethal arrhythmias. In response to such oxidative stress, dysregulation of ion homeostasis, activation of neurohumoral system, immune and inflammatory responses, are augmented. These events are inter-related, and as a complex promote electrical instability. Likewise, remodeling occurring after the loss of cardiomyocytes, induces the development of a proarrhythmogenic environment. Thus, CA oxidation products may be involved in triggering arrhythmias as a result of both changes in cardiac cell automaticity and conduction velocity. In contrast, sulphur-containing amino acids (S-AA), in particular taurine and its precursor cysteine have been shown to modulate redox state of the heart. However, the multiple anti-oxidant properties of S-AA are unlikely to be exclusively responsible for their anti-arrhythmic action. They also possess additional cytoprotective effects which can stabilize electrical activity of the heart. CONCLUSION: It is concluded that specific S-AA may attenuate deleterious effects of supraphysiological levels of CA and this could serve as an important mechanism for the treatment and/or prevention of arrhythmogenesis.

Attenuation of Diabetes-induced Cardiac and Subcellular Defects by Sulphur-containing Amino Acids.

BACKGROUND: Patients with diabetes mellitus have an increased risk of mortality due to cardiovascular complications. Supplementation with specific sulphur-containing amino acids is rapidly emerging as a possible therapeutic adjuvant for diabetes and associated cardiovascular complications. OBSERVATIONS: It is well-known that oxidative stress plays an important role in the pathogenesis of diabetes-induced cardiovascular disease, which is invariably associated with abnormal blood lipid profile, insulin resistance and other symptoms of metabolic syndrome. Cysteine and taurine are among the most common sulphur-containing amino acids and their cellular levels decline during diabetes that may contribute to the development of the cardiomyopathy. Although sulphur-containing agents exert multiple actions on cellular and subcellular functions in the heart, they also exhibit antioxidant properties and thus may exert beneficial effects in different pathophysiological conditions. CONCLUSION: It is concluded that reduction of oxidative stress by cysteine and taurine may serve as an important mechanism for the attenuation of diabetes-induced subcellular and functional abnormalities in the heart.