Friend or Foe? An Unrecognized Role of Uric Acid in Cancer Development and the Potential Anticancer Effects of Uric Acid-lowering Drugs

Metabolic signatures of metabolites of the purine degradation pathway in human plasma using HILIC UHPLC-HRMS

The metabolic disorders in the purine degradation pathway have proven to be closely associated with several human diseases. However, the etiology is not yet fully understood. Profile assay of purine intermediates and uric acid involved in the metabolic pathway can provide additional insight into the nature and severity of related diseases. Purine metabolites are endogenous chemicals with high hydrophilicity, polarity, and similar structures, thus there is a great need for a specific method to quantify them directly in biological fluids with a short running time. Herein, eight purine degradation pathway metabolites, including xanthine, hypoxanthine, guanine, xanthosine, inosine, guanosine, adenosine and uric acid, in human plasma were quantitatively measured using hydrophilic interaction chromatography-tandem high-resolution mass spectrometry (HILIC-HRMS) in a short running time of 10 min. The method was systematically validated for specificity, linearity of the calibration curve, the limit of detection, the limit of quantification, the lower limit of quantification, precision, accuracy, extraction recovery, matrix effect, and stability. The results showed that the method was linear (R2 > 0.99), accurate (the intra- and inter-day recoveries of all analytes ranged from 90.0 % to 110.0 %), and precise (the intra- and inter-day precisions were less than 6.7 % and 8.9 %, respectively) with the lower limits of quantification ranging from 3 to 10,000 ng/mL. The extraction recoveries and matrix effects were repeatable and stable. All the analytes were stable in the autosampler and could be subject to three freeze-thaw cycles. The developed method was ultimately applied to 100 plasma specimens from healthy individuals. The results showed that the concentrations of different purine metabolites varied dramatically in plasma specimens. Diet and body mass index (BMI) were the most significant factors determining purine levels, followed by drinking and sex. Age, smoking and bedtime showed a very weak correlation with purine metabolism. The findings of the present work reveal the characteristics of purine metabolism in human plasma under non-pathological conditions. The results also highlight the factors that can cause changes in purine metabolism, which are useful in developing effective treatment strategies for metabolic disorders of purines, particularly for those caused by lifestyle factors.

Association between serum uric acid and colorectal cancer risk in European population: a two-sample Mendelian randomization study

Objectives

This study aimed to explore the potential causal associations between serum uric acid (SUA) and the risk of colorectal cancer, colon cancer and rectal cancer.

Methods

Twenty-six SUA-related single nucleotide polymorphisms which were identified by a large meta-analysis of genome-wide association studies (GWASs) were used as instrumental variables in the two-sample Mendelian randomization (MR) study. Meta-analyses were used to synthesize the results of multiple GWASs which were extracted from the MRC Integrative Epidemiology Unit GWAS database for each type of cancer. The inverse variance weighted (IVW) method was used as the primary MR method to analyze the association between SUA and colorectal cancer risk. Several sensitivity analyses were performed to test the robustness of results.

Results

The IVW method showed that there were no causal relationships between SUA and the risk of colorectal cancer [odds ratio (OR): 1.0015; 95% confidence interval (CI): 0.9975-1.0056] and colon cancer (OR: 1.0015; 95% CI: 0.9974-1.0055). The SUA levels were negative correlated with rectal cancer risk (OR: 0.9984; 95% CI: 0.9971-0.9998). The similar results were observed in both males (OR: 0.9987; 95% CI: 0.9975-0.9998) and females (OR: 0.9985; 95% CI: 0.9971-0.9999). The sensitivity analyses suggested no evidence of heterogeneity or horizontal pleiotropy. The leave-one-out analyses showed that one SNP (rs1471633) significantly drove the causal effect of SUA on rectal cancer risk. The MR-Egger regression and weighted median both showed that there were no causal relationships between SUA and the risk of colorectal cancer and its subtypes.

Conclusion

Overall, there was no linear causal association between SUA and the risk of colorectal cancer. However, further research is needed to investigate the role of higher SUA levels such as hyperuricemia or gout in the occurrence of colorectal cancer.

Prescribing cascades of antigout medications from thiazide diuretics in gout-naïve hypertensive adults receiving first-line pharmacological management

Prescribing cascade is a significant clinical problem but is often overlooked. We explore the incidence of the prescribing cascades of antigout medications related to thiazide treatment in gout-naïve hypertensive adults newly exposed to the pharmacological treatment. This population-based, retrospective cohort study used the Taiwan National Health Insurance Registry Database. Gout-naïve hypertensive adults who were newly dispensed first-line antihypertensive drugs between January 1, 2000, and December 31, 2016, were enrolled. Patients were divided into the thiazide group (n = 4192) and the non-thiazide group (n = 81,083). The non-thiazide group included patients who received an angiotensin-converting enzyme inhibitor, angiotensin II receptor blocker, calcium channel blocker, or beta-blocker. The study utilized propensity score matching and multivariable Cox regression models to investigate the prescribing cascade of antigout agents following antihypertensive treatment, adjusting for factors like age, sex, comorbidities, and concurrent medications. After propensity score matching, each group consisted of 4045 patients, with the thiazide group exhibiting a higher risk of being prescribed antigout medications across different time intervals post-treatment initiation. Specifically, adjusted hazard ratios (aHRs) for the thiazide group were 2.23, 2.07, and 2.41 for < 30 days, 31-180 days, and > 180 days, respectively, indicating a sustained and significant risk over time. Comparative analyses revealed thiazide diuretics were associated with a higher risk of antigout medication prescriptions compared to other antihypertensive classes, particularly evident after 180 days. Subgroup analyses across various demographics and comorbidities consistently showed an increased risk in the thiazide cohort. Gout-naïve hypertensive adults newly dispensed thiazide had a higher risk of subsequently adding antigout agents than those taking other first-line antihypertensive medications. The awareness and interruption of these prescribing cascades are critical to improving patient safety.

Antimicrobial Properties of Colostrum and Milk

The growing number of antibiotic resistance genes is putting a strain on the ecosystem and harming human health. In addition, consumers have developed a cautious attitude towards chemical preservatives. Colostrum and milk are excellent sources of antibacterial components that help to strengthen the immunity of the offspring and accelerate the maturation of the immune system. It is possible to study these important defenses of milk and colostrum, such as lactoferrin, lysozyme, immunoglobulins, oligosaccharides, etc., as biotherapeutic agents for the prevention and treatment of numerous infections caused by microbes. Each of these components has different mechanisms and interactions in various places. The compound's mechanisms of action determine where the antibacterial activity appears. The activation of the antibacterial activity of milk and colostrum compounds can start in the infant's mouth during lactation and continue in the gastrointestinal regions. These antibacterial properties possess potential for therapeutic uses. In order to discover new perspectives and methods for the treatment of bacterial infections, additional investigations of the mechanisms of action and potential complexes are required.

Exposure to Chinese famine and the risk of hyperuricemia in later life: a population-based cross-sectional study

Background

Limited studies have investigated the relationship between famine exposure and the risk of hyperuricemia in later life. Consequently, the primary purpose of the current study was to examine the potential association between exposure to Chinese famine and hyperuricemia, as well as any gender disparities in this relationship.

Method

The data were obtained from the China PEACE (China Patient-Centered Evaluative Assessment of Cardiac Events) Million Persons Project in Rongchang. The study participants were enrolled into different cohorts based on their birthdates: the fetal-exposed cohort (born between 1959 and 1962), the childhood-exposed cohort (born between 1949 and 1958), the adolescence-exposed cohort (born between 1941 and 1948), and the non-exposed cohorts (born between 1963 and 1974). The potential association between famine exposure and hyperuricemia was assessed using binary logistic regression models.

Results

A total of 6,916 individuals were enrolled in the current study with an average age of 60.11 ± 9.22 years, out of which 3,544 were women. After adjusting for confounding factors, fetal (OR = 0.530, 95% CI: 0.411-0.0.683), childhood (OR = 0.642, 95% CI: 0.494-0.833) exposure to the Chinese famine for men was negatively associated with hyperuricemia. Conversely, exposure to the Chinese famine during fetal (OR = 2.144, 95% CI: 1.622-2.834), childhood (OR = 1.485, 95% CI: 1.105-1.997), and adolescence (OR = 1.967, 95% CI: 1.465-2.641) for women was positively associated with hyperuricemia. Furthermore, the impact of famine on hyperuricemia that has been observed in exposed women might be intensified by the presence of dyslipidemia, abdominal obesity, and overweight/obesity.

Conclusion

Women exposed to the Chinese famine during fetal, childhood, and adolescence were positively associated with hyperuricemia, while men exhibited a negative association during fetal and childhood. Additionally, the effect of famine on hyperuricemia in exposed women appears to be intensified by the presence of dyslipidemia, abdominal obesity, and overweight/obesity.

Longitudinal changes in high sensitivity C-reactive protein associated with serum uric acid in the Korean Genome and Epidemiology Study

Cross-sectional studies support the role of serum uric acid (SUA) in inflammation, but evidence from cohort studies is scarce. Longitudinal associations between SUA and high-sensitivity C-reactive protein (hs-CRP) were examined in the general population. Data for participants from the Health Examinees-Gem cohort (n = 50,028; 40-69 years; 67% women) who were examined between 2004 and 2013 and followed up until 2016 were analyzed. SUA and hs-CRP were measured at baseline and during follow-up. SUA was evaluated as a continuous variable and was also divided into sex-specific quartiles. Mean hs-CRP levels at follow-up were evaluated using multivariable proportional odds regression, with non-linear smoothed baseline hs-CRP levels serving as a covariate. Selected pathological markers were also examined in relation to hs-CRP. Increased levels of SUA at baseline were related to increased levels of hs-CRP at follow-up [regression coefficient per mg/dL increase in baseline SUA (β) = 0.08, 95% confidence interval (CI), 0.040-0.128]. A dose-response relationship was observed, (P for linear trend = 0.0015). The mean values of hs-CRP were highest among participants with the highest follow-up but lowest baseline SUA levels. Elevated hs-CRP levels at follow up (> 3 mg/L) were positively related to fasting blood glucose levels, triglycerides levels, liver enzymes, and blood pressure, but negatively related to high density lipoprotein cholesterol levels per unit increase in baseline hs-CRP. High SUA levels were associated with high hs-CRP levels, suggesting a potential role of SUA in inflammation. However, additional research is needed to confirm these findings.

Serum uric acid and the risk of colorectal cancer: a meta-analysis

BACKGROUND

A meta-analysis was performed in this study to evaluate the association between serum uric acid and the risk of colorectal cancer (CRC).

METHODS

Relevant observational studies observing the relationship between uric acid and the incidence of CRC were obtained by the search of electronic databases, including Medline, Embase, Cochrane Library and Web of Science . A randomized-effects model was selected to pool the data by incorporating the influence of potential heterogeneity.

RESULTS

Eight observational studies involving 1,226,379 adults were included. During a mean follow-up duration of 12.8 years, CRC was developed in 12349 (1.0%) participants. Pooled results showed that compared to those with the lowest category of serum uric acid at baseline, participants with the highest category of serum uric acid had an increased incidence of CRC during follow-up [risk ratio (RR), 1.28; 95% confidence interval (CI), 1.17-1.42; P  < 0.001; I2  = 0%]. Sensitivity analysis limited to prospective cohort studies retrieved similar results (RR, 1.32; 95% CI, 1.19-1.47; P  < 0.001; I2  = 0%). Subgroup analyses showed consistent results in men and women, in estimates of the incidence of colon cancer and rectal cancer and in studies with different follow-up durations and quality scores ( P for subgroup differences all > 0.05).

CONCLUSION

Although the cutoff for defining a high uric acid varied among the included studies, results of the meta-analysis suggest that a high serum uric acid may be associated with an increased risk of CRC in an adult population.

Potential antioxidative and anti-hyperuricemic components in Rodgersia podophylla A. Gray revealed by bio-affinity ultrafiltration with SOD and XOD

Rodgersia podophylla A. Gray (R. podophylla) is a traditional Chinese medicine with various pharmacological effects. However, its antioxidant and anti-hyperuricemia components and mechanisms of action have not been explored yet. In this study, we first assessed the antioxidant potential of R. podophylla with 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and ferric ion reducing antioxidant power (FRAP) assays. The results suggested that the ethyl acetate (EA) fraction of R. podophylla not only exhibited the strongest DPPH, ABTS radical scavenging and ferric-reducing activities, but also possessed the highest total phenolic and total flavonoid contents among the five fractions. After that, the potential superoxide dismutase (SOD) and xanthine oxidase (XOD) ligands from the EA fraction were quickly screened and identified through the bio-affinity ultrafiltration liquid chromatography-mass spectrometry (UF-LC-MS). Accordingly, norbergenin, catechin, procyanidin B2, 4-O-galloylbergenin, 11-O-galloylbergenin, and gallic acid were considered to be potential SOD ligands, while gallic acid, 11-O-galloylbergenin, catechin, bergenin, and procyanidin B2 were recognized as potential XOD ligands, respectively. Moreover, these six ligands effectively interacted with SOD in molecular docking simulation, with binding energies (BEs) ranging from -6.85 to -4.67 kcal/mol, and the inhibition constants (Ki) from 9.51 to 379.44 μM, which were better than the positive controls. Particularly, catechin exhibited a robust binding affinity towards XOD, with a BE value of -8.54 kcal/mol and Ki value of 0.55 μM, which surpassed the positive controls. In conclusion, our study revealed that R. podophylla possessed remarkable antioxidant and anti-hyperuricemia activities and that the UF-LC-MS method is suitable for screening potential ligands for SOD and XOD from medicinal plants.

Review on Uric Acid Recognition by MOFs with a Future in Machine Learning

Uric acid (UA) is produced from purine metabolism and serves as a prevalent biomarker for multiple diseases including cancer. Hyperuricemia or hypouricemia can cause multiple dysfunctions throughout the biological processes. Consequently, there is a pressing need for monitoring UA concentration in body fluid. While clinical methods are known, the availability of a point-of-care testing (PoCT) kit remains conspicuously absent. In the case of electrochemical recognition of UA, the oxidation potential of ascorbic acid closely aligns with that of UA and thus it hinders the detection process, which eventually may result in false positive signals. Several chemosensors are known in the field of supramolecular chemistry, and metal-organic frameworks (MOFs) are one of the best-performing contenders due to their robustness, stability, and versatile structures. In this review, we tried to unbox the up-to-date development of UA sensing by MOFs. We delve into the state of UA recognition by MOFs, exploring both electrochemical and fluorometric pathways and drawing comparisons with structurally similar probes like covalent organic frameworks (COFs) to understand/establish the advantages of MOFs specifically in UA sensing. In the absence of a PoCT kit, we have provided the conceptual outlook for designing a PoCT device termed a "Urimeter" via electrochemical operation. For the first time, we have proposed different methods of how UA sensing can be tied up with artificial intelligence and machine learning (AI-ML).

Synthesis of Quinazolin-2,4,6-triamine Derivatives as Non-purine Xanthine Oxidase Inhibitors and Exploration of Their Toxicological Potential

In this work, a new set of quinazolin-2,4,6-triamine derivatives were synthesized to explore their potential biological activity as xanthine oxidase (XO) inhibitors, superoxide scavengers and screening of their toxicological profile. Among all the synthesized compounds, B1 exhibited better inhibitory activity against bovine xanthine oxidase (bXO) than allopurinol (IC50 =1.56 μM and IC50 =6.99 μM, respectively). As superoxide scavengers, B1, B2 and B13 exhibited a better effect than allopurinol (97.3 %, 82.1 %, 87.4 % and 69.4 %, respectively). Regarding the toxicological profile, B1 was less cytotoxic than methotrexate on HCT-15 cancer cells. Apoptosis results obtained in cells of female and male mice, showed that B1 and B2 presented a similar behaviour to CrO3 (positive control) with respect to the average frequency to induce apoptosis; while B13 apoptosis induced effect was similar to DMSO and control group. Finally, B1, B2, B13 did not induce genotoxicity in a micronuclei murine model compared to CrO3 .

PAICS as a potential target for cancer therapy linking purine biosynthesis to cancer progression

Tumor cells are required to undergo metabolic reprogramming for rapid development and progression, and one of the metabolic characteristics of cancer cells is the excessive synthesis and utilization of nucleotides. Abnormally increased nucleotides and their metabolites not only directly accelerate tumor cell progression but also indirectly act on stromal cells in the tumor microenvironment (TME) via a paracrine manner to regulate tumor progression. Purine nucleotides are mainly produced via de novo nucleotide synthesis in tumor cells; therefore, intervening in their synthesis has emerged as a promising strategy in anti-tumor therapy. De novo purine synthesis is a 10-step reaction catalyzed by six enzymes to synthesize inosine 5-monophosphate (IMP) and subsequently synthesize AMP and GMP. Phosphoribosylaminoimidazole carboxylase/phosphori-bosylaminoimidazole succinocarboxamide synthetase (PAICS) is a bifunctional enzyme that catalyzes de novo purine synthesis. Aberrantly elevated PAICS expression in various tumors is associated with poor prognosis. Evidence suggests that PAICS and its catalytic product, N-succinylcarboxamide-5-aminoimidazole ribonucleotide (SAICAR), could inhibit tumor cell apoptosis and promote the growth, epithelial-mesenchymal transition (EMT), invasion, and metastasis by regulating signaling pathways such as pyruvate kinase M2 (PKM2), extracellular signal-related kinases 1 and 2 (ERK1/2), focal adhesion kinase (FAK) and so on. This review summarizes the structure, biological functions and the molecular mechanisms of PAICS in cancer development and discusses its potential to be a target for tumor therapy.

Effectiveness of Treatments That Alter Metabolomics in Cancer Patients-A Systematic Review

INTRODUCTION

Cancer is the leading cause of death worldwide, with the most frequent being breast cancer in women, prostate cancer in men and colon cancer in both sexes. The use of metabolomics to find new biomarkers can provide knowledge about possible interventions based on the presence of oncometabolites in different cancer types.

OBJECTIVES

The primary purpose of this review is to analyze the characteristic metabolome of three of the most frequent cancer types. We further want to identify the existence and success rate of metabolomics-based intervention in patients suffering from those cancer types. Our conclusions are based on the analysis of the methodological quality of the studies.

METHODS

We searched for studies that investigated the metabolomic characteristics in patients suffering from breast cancer, prostate cancer or colon cancer in clinical trials. The data were analyzed, as well as the effects of specific interventions based on identified metabolomics and one or more oncometabolites. The used databases were PubMed, Virtual Health Library, Web of Science, EBSCO and Cochrane Library. Only nine studies met the selection criteria. Study bias was analyzed using the Cochrane risk of bias tool. This systematic review protocol was registered at the International Prospective Register of Systematic Reviews (PROSPERO: CRD42023401474).

RESULTS

Only nine studies about clinical trials were included in this review and show a moderate quality of evidence. Metabolomics-based interventions related with disease outcome were conflictive with no or small changes in the metabolic characteristics of the different cancer types.

CONCLUSIONS

This systematic review shows some interesting results related with metabolomics-based interventions and their effects on changes in certain cancer oncometabolites. The small number of studies we identified which fulfilled our inclusion criteria in this systematic review does not allow us to draw definitive conclusions. Nevertheless, some results can be considered as promising although further research is needed. That research must focus not only on the presence of possible oncometabolites but also on possible metabolomics-based interventions and their influence on the outcome in patients suffering from breast cancer, prostate cancer or colon cancer.

Prognostic Implication of Plasma Metabolites in Gastric Cancer

Gastric cancer (GC) typically carries a poor prognosis as it is often diagnosed at a late stage. Altered metabolism has been found to impact cancer outcomes and affect patients' quality of life, and the role of metabolites in gastric cancer prognosis has not been sufficiently understood. We aimed to establish a prognostic prediction model for GC patients based on a metabolism-associated signature and identify the unique role of metabolites in the prognosis of GC. Thus, we conducted untargeted metabolomics to detect the plasma metabolites of 218 patients with gastric adenocarcinoma and explored the metabolites related to the survival of patients with gastric cancer. Firstly, we divided patients into two groups based on the cutoff value of the abundance of each of the 60 metabolites and compared the differences using Kaplan-Meier (K-M) survival analysis. As a result, 23 metabolites associated with gastric cancer survival were identified. To establish a risk score model, we performed LASSO regression and Cox regression analysis on the 60 metabolites and identified 8 metabolites as an independent prognostic factor. Furthermore, a nomogram incorporating clinical parameters and the metabolic signature was constructed to help individualize outcome predictions. The results of the ROC curve and nomogram plot showed good predictive performance of metabolic risk features. Finally, we performed pathway analysis on the 24 metabolites identified in the two parts, and the results indicated that purine metabolism and arachidonic acid metabolism play important roles in gastric cancer prognosis. Our study highlights the important role of metabolites in the progression of gastric cancer and newly identified metabolites could be potential biomarkers or therapeutic targets for gastric cancer patients.

J-shaped association between uric acid and breast cancer risk: a prospective case-control study

BACKGROUND/AIM

In terms of breast cancer risk, there is no consensus on the effect of uric acid (UA) levels. The aim of our study was to clarify the link between UA and breast cancer risk in a prospective case-control study and to find the UA threshold point.

METHODS

We designed a case-control study with 1050 females (525 newly diagnosed breast cancer patients and 525 controls). We measured the UA levels at baseline and confirmed the incidence of breast cancer through postoperative pathology. We used binary logistic regression to study the association between breast cancer and UA. In addition, we performed restricted cubic splines to evaluate the potential nonlinear links between UA and breast cancer risk. We used threshold effect analysis to identify the UA cut-off point.

RESULTS

After adjusting for multiple confounding factors, we found that compared with the referential level (3.5-4.4 mg/dl), the odds ratio (OR) of breast cancer was 1.946 (95% CI 1.140-3.321) (P < 0.05) in the lowest UA level and 2.245 (95% CI 0.946-5.326) (P > 0.05) in the highest level. Using the restricted cubic bar diagram, we disclosed a J-shaped association between UA and breast cancer risk (P-nonlinear < 0.05) after adjusting for all confounders. In our study, 3.6 mg/dl was found to be the UA threshold which acted as the optimal turning point of the curve. The OR for breast cancer was 0.170 (95% CI 0.056-0.512) to the left and 1.283 (95% CI 1.074-1.532) to the right of 3.6 mg/dl UA (P for log likelihood ratio test < 0.05).

CONCLUSION

We found a J-shaped association between UA and breast cancer risk. Controlling the UA level around the threshold point of 3.6 mg/dl provides a novel insight into breast cancer prevention.

Association between gout and subsequent breast cancer: a retrospective cohort study including 67,598 primary care patients in Germany

PURPOSE

The aim of this retrospective cohort study was to analyze the cumulative incidence of breast cancer following gout and to investigate the association between gout and subsequent breast cancer in 67,598 primary care patients in Germany.

METHODS

This study included adult female patients (≥ 18 years) with an initial diagnosis of gout in 1284 general practices in Germany between January 2005 and December 2020. Individuals without gout were matched to gout patients using propensity score matching based on average yearly consultation frequency during the follow-up period, diabetes, obesity, chronic bronchitis/COPD diagnoses, and diuretic therapy. The 10-year cumulative incidence of breast cancer in the cohorts with and without gout was also studied using Kaplan-Meier curves, which were then compared using the log-rank test. Finally, a univariable Cox regression analysis was conducted to assess the association between gout and breast cancer.

RESULTS

After up to 10 years of follow-up, 4.5% of gout and 3.7% of non-gout patients were diagnosed with breast cancer. A Cox regression analysis revealed a significant association between gout and subsequent breast cancer in the total population (HR: 1.17; 95% CI: 1.05-1.31). In the age-stratified analyses, gout was only strongly associated with subsequent breast cancer in the age group ≤ 50 (HR: 1.58; 95% CI: 1.10-2.27), but the association was not significant in women over 50 years old.

CONCLUSION

Taken together, the findings of our study provide evidence for the association between gout and subsequent breast cancer diagnosis, particularly in the youngest age group.

Impairment of kidney function and kidney cancer: A bidirectional Mendelian randomization study

BACKGROUND

Many observational epidemiology studies discovered that kidney cancer and impaired kidney function have a bidirectional relationship. However, it remains unclear whether these two kinds of traits are causally linked. In this study, we aimed to investigate the bidirectional causal relation between kidney cancer and kidney function biomarkers (creatinine-based estimated glomerular filtration rate (eGFRcrea), cystatin C-based estimated glomerular filtration rate (eGFRcys), blood urea nitrogen (BUN), serum urate, and urinary albumin-to-creatinine ratio (UACR)).

METHODS

For both directions, single-nucleotide polymorphisms (SNPs), as genetic instruments, for the five kidney function traits were selected from up to 1,004,040 individuals, and SNPs for kidney cancer were from 408,786 participants(1338 cases). In the main analysis, we applied two state-of-the-art MR methods, namely, contamination mixture and Robust Adjusted Profile Score to downweight the effect of weak instrument bias, pleiotropy, and extreme outliers. We additionally conducted traditional MR analyses as sensitivity analyses. Summary-level data of European ancestry were extracted from UK Biobank, Chronic Kidney Disease Genetics Consortium, and Kaiser Permanente.

RESULTS

Based on 99 SNPs, we found that the eGFRcrea had a significant negative causal effect on the risk of kidney cancer (OR = 0.007, 95% CI:2.6 × 10-4 -0.569, p = 0.041). After adjusting for body composition or diabetes, urate had a significant negative causal effect on kidney cancer (OR <1, p < 0.05). For UACR, it showed a strong causal effect on kidney cancer, after adjusting for body composition (OR = 14.503, 95% CI: 2.546-96.001, p = 0.032). Due to lacking significant signals and effect power for the reverse MR, further investigations are warranted.

CONCLUSIONS

Our study suggested a potential causal effect of damaged kidney function on kidney cancer. EGFRcrea and UACR might be causally associated with kidney cancer, especially when patients were comorbid with obesity or diabetes. We called for larger sample-size studies to further unravel the underlying causal relationship and the exact mechanism.

The Good, the Bad and the New about Uric Acid in Cancer

Simple Summary

The concentration of uric acid in blood is sex-, age- and diet-dependent and is maintained close to its maximal solubility, indicating that it plays some important role. Indeed, it has been demonstrated that, at physiological concentrations, uric acid is a powerful antioxidant and is a scavenger of singlet oxygen and radicals. At high intracellular concentration, uric acid has been demonstrated to act as a pro-oxidant molecule. Recently, uric acid has been reported to affect the properties of several proteins involved in metabolic regulation and signaling, and the relationship between uric acid and cancer has been extensively investigated. In this review, we present the most recent results on the positive and negative effects played by uric acid in cancer and some new findings and hypotheses about the implication of this metabolite in the pathogenesis of several diseases such as metabolic syndrome, diabetes, and inflammation, thus favoring the development of cancer.

Abstract

Uric acid is the final product of purine catabolism in man and apes. The serum concentration of uric acid is sex-, age- and diet-dependent and is maintained close to its maximal solubility, indicating that it plays some important role. Indeed, it has been demonstrated that, at physiological concentrations, uric acid is a powerful antioxidant, while at high intracellular concentrations, it is a pro-oxidant molecule. In this review, we describe the possible causes of uric acid accumulation or depletion and some of the metabolic and regulatory pathways it may impact. Particular attention has been given to fructose, which, because of the complex correlation between carbohydrate and nucleotide metabolism, causes uric acid accumulation. We also present recent results on the positive and negative effects played by uric acid in cancer and some new findings and hypotheses about the implication of this metabolite in a variety of signaling pathways, which can play a role in the pathogenesis of diseases such as metabolic syndrome, diabetes, and inflammation, thus favoring the development of cancer. The loss of uricase in Homo sapiens and great apes, although exposing these species to the potentially adverse effects of uric acid, appears to be associated with evolutionary advantages.

The relationship between serum uric acid and colorectal cancer: a prospective cohort study

Serum uric acid (SUA) may play an important role in the occurrence of colorectal cancer (CRC). This study aims to explore the association of SUA with the risk of CRC incidence by drawing data from the Kailuan Study. We prospectively examined the association between SUA and risk of CRC incidence among 93,356 Chinese. Eligible participants were divided into three groups based on their tertiles of SUA. Cox proportional hazards regression was used to calculate the hazard ratios (HRs) and 95% confidence intervals (95% CIs) of CRC. During a median follow-up of 13.02 years, 583 new-onset CRC cases were identified. After adjustments were made for confounders, participants in the highest tertiles of SUA exhibited a 1.55-fold increased risk of CRC compared with patients with the lowest SUA levels (HR_{T3 vs. T1} = 1.55, 95% CI: 1.09-2.30). The associations of SUA with the risk of CRC were slightly reduced but remained substantial in the competing risk analyses when treating CRC unrelated death as the competing risk event. This study found a positive association of SUA with CRC incidence. Specific prevention efforts could be focused on the population with higher levels of SUA.

Adenosine, Schizophrenia and Cancer: Does the Purinergic System Offer a Pathway to Treatment?

For over a century, a complex relationship between schizophrenia diagnosis and development of many cancers has been observed. Findings from epidemiological studies are mixed, with reports of increased, reduced, or no difference in cancer incidence in schizophrenia patients. However, as risk factors for cancer, including elevated smoking rates and substance abuse, are commonly associated with this patient population, it is surprising that cancer incidence is not higher. Various factors may account for the proposed reduction in cancer incidence rates including pathophysiological changes associated with disease. Perturbations of the adenosine system are hypothesized to contribute to the neurobiology of schizophrenia. Conversely, hyperfunction of the adenosine system is found in the tumor microenvironment in cancer and targeting the adenosine system therapeutically is a promising area of research in this disease. We outline the current biochemical and pharmacological evidence for hypofunction of the adenosine system in schizophrenia, and the role of increased adenosine metabolism in the tumor microenvironment. In the context of the relatively limited literature on this patient population, we discuss whether hypofunction of this system in schizophrenia, may counteract the immunosuppressive role of adenosine in the tumor microenvironment. We also highlight the importance of studies examining the adenosine system in this subset of patients for the potential insight they may offer into these complex disorders.

Preoperative monocyte-to-lymphocyte ratio as a potential predictor of bladder cancer

OBJECTIVES

The aim of this study was to investigate the role of preoperative Monocyte-to-Lymphocyte ratio (MLR) as a potential predictor of bladder cancer (BC).

METHODS

Clinical data of patients who underwent TURBT at our institution between 2017 and 2021 were collected and retrospectively analysed. MLR was obtained from preoperative blood analyses performed within 1 month from hospital admission. The association of MLR with different clinic-pathological features obtained from histological reports was further analysed. Statistical analysis was performed using the Kruskal Wallis test for non-parametric variables, assuming p<0.05 as statistically significant.

RESULTS

510 patients were included in the study (81% males, 19% females), with a mean age of 71.66 ± 11.64 years. Mean MLR was higher in patients with any-type bladder cancer, reporting an MLR of 0.41 ± 0.11 compared to 0.38 ± 0.43 in patients without bladder cancer (p=0.043). In the subsequent comparison among low-grade and high-grade bladder cancer, MLR did not report statistically significant differences, with 0.29 ± 0.12 for low-grade BC and 0.51 ± 0.81 for high-grade BC (p=0.085).

CONCLUSIONS

Our findings reported elevated preoperative MLR should be considered a potential biomarker predicting malignancy for bladder tumours. Furthermore, research are necessary to assess its role in discerning low-grade from high-grade patients.

Phase II Trial of Sipuleucel-T and Stereotactic Ablative Body Radiation for Patients with Metastatic Castrate-Resistant Prostate Cancer

(1) We hypothesized that adding concurrent stereotactic ablative radiotherapy (SAbR) would increase the time to progression in patients with metastatic castrate-resistant prostate cancer (mCRPCA) treated with sipuleucel-T. (2) Patients with a history of prostate cancer (PC), radiographic evidence of metastatic disease, and rising prostate-specific antigen (PSA) > 0.2 ng/dL on castrate testosterone levels were enrolled in this single-arm phase II clinical trial and treated with sipuleucel-T and SAbR. The primary endpoint was time to progression (TTP). Cellular and humoral responses were measured using ELISpot and Luminex multiplex assays, respectively. (3) Twenty patients with mCRPC were enrolled and treated with SAbR to 1−3 sites. Treatment was well tolerated with 51, 8, and 4 treatment-related grade 1, 2, and 3 toxicities, respectively, and no grade 4 or 5 adverse events. At a median follow-up of 15.5 months, the median TTP was 11.2 weeks (95% CI; 6.8−14.0 weeks). Median OS was 76.8 weeks (95% CI; 41.6−130.8 weeks). This regimen induced both humoral and cellular immune responses. Baseline M-MDSC levels were elevated in mCRPC patients compared to healthy donors (p = 0.004) and a decline in M-MDSC was associated with biochemical response (p = 0.044). Responders had lower baseline uric acid levels (p = 0.05). No clear correlation with radiographic response was observed. (4) While the regimen was safe, the PC-antigen-specific immune response induced by SAbR did not yield a synergistic clinical benefit for patients treated with sipuleucel-T compared to the historically reported outcomes.

Metabolomics and the Multi-Omics View of Cancer

Cancer is widely regarded to be a genetic disease. Indeed, over the past five decades, the genomic perspective on cancer has come to almost completely dominate the field. However, this genome-only view is incomplete and tends to portray cancer as a disease that is highly heritable, driven by hundreds of complex genetic interactions and, consequently, difficult to prevent or treat. New evidence suggests that cancer is not as heritable or purely genetic as once thought and that it really is a multi-omics disease. As highlighted in this review, the genome, the exposome, and the metabolome all play roles in cancer’s development and manifestation. The data presented here show that >90% of cancers are initiated by environmental exposures (the exposome) which lead to cancer-inducing genetic changes. The resulting genetic changes are, then, propagated through the altered DNA of the proliferating cancer cells (the genome). Finally, the dividing cancer cells are nourished and sustained by genetically reprogrammed, cancer-specific metabolism (the metabolome). As shown in this review, all three “omes” play roles in initiating cancer. Likewise, all three “omes” interact closely, often providing feedback to each other to sustain or enhance tumor development. Thanks to metabolomics, these multi-omics feedback loops are now much more evident and their roles in explaining the hallmarks of cancer are much better understood. Importantly, this more holistic, multi-omics view portrays cancer as a disease that is much more preventable, easier to understand, and potentially, far more treatable.

Purine metabolites and complex diseases: role of genes and nutrients

PURPOSE OF REVIEW

Purines have several important physiological functions as part of nucleic acids and as intracellular and extracellular signaling molecules. Purine metabolites, particularly uric acid, have been implicated in congenital and complex diseases. However, their role in complex diseases is not clear and they have both beneficial and detrimental effects on disease pathogenesis. In addition, the relationship between purines and complex diseases is affected by genetic and nutritional factors. This review presents latest findings about the relationship between purines and complex diseases and the effect of genes and nutrients on this relationship.

RECENT FINDINGS

Evidence from recent studies show strong role of purines in complex diseases. Although they are causal in only few diseases, our knowledge about their role in other diseases is still evolving. Of all the purines, uric acid is the most studied. Uric acid acts as an antioxidant as well as a prooxidant under different conditions, thus, its role in disease also varies. Other purines, adenosine and inosine have been less studied, but they have neuroprotective properties which are valuable in neurodegenerative diseases.

SUMMARY

Purines are molecules with great potential in disease pathogenesis as either metabolic markers or therapeutic targets. More studies need to be conducted to understand their relevance for complex diseases.

Serum Uric Acid Levels and Risk of Eight Site-Specific Cancers: A Mendelian Randomization Study

The relationship between serum uric acid (UA) levels and cancer risk remains controversial. Here, a two-sample Mendelian randomization analysis was performed to identify a causal effect of serum UA levels on cancer risk. Twenty-six single nucleotide polymorphisms strongly associated with serum UA levels were screened as genetic variants from large-scale meta-analysis data of a genome-wide association study of 110,347 European individuals. Genetic associations with eight common site-specific cancers were subsequently explored. A total of six Mendelian randomization methods were used to estimate the potential effect of serum UA levels on cancer risk, including random effects inverse variance weighting, fix effects inverse variance weighting, MR-Egger, median weighting, mode weighting, and simple mode analysis. Our primary random effects inverse variance weighted analysis revealed that no significant associations with cancers was found (all p > 0.05). Sensitivity analyses and additional analyses also showed similar pooled results. In conclusion, no significant causality between serum UA levels and cancer risk was evidenced.

Increased oxidative stress and inflammatory markers contrasting with the activation of the cholinergic anti-inflammatory pathway in patients with metabolic syndrome

INTRODUCTION

Metabolic syndrome (MetS) is a disorder that is closely associated with risk factors that increase the chance of atherosclerosis and cardiovascular diseases. We demonstrate the presence of inflammation and oxidative stress in patients with MetS through levels of antioxidants and oxidative and inflammatory markers, in order to determine influential variables in therapy.

METHODS

In this study, lipid peroxidation, carbonylated protein content and enzymatic and non-enzymatic antioxidants were evaluated in samples obtained from 30 patients with MetS and 30 control patients. In addition, acetylcholinesterase (AChE) activity, C-reactive protein (CRP) and uric acid (UA) levels were determined to investigate the inflammatory process in patients with MetS.

RESULTS

Our results demonstrated an increase in the levels of oxidative markers, such as substances reactive to thiobarbituric acid (TBARS) and carbonyl protein. In addition, a decrease in the defense of non-enzymatic antioxidants, such as levels of vitamin C and glutathione (GSH) in patients with MetS. As for inflammatory markers, CRP and UA were increased in patients with MetS. Finally, activation of the cholinergic anti-inflammatory pathway was observed due to decreased AchE activity in patients with MetS.

CONCLUSION

The analyzes indicated oxidative stress, together with a reduction in the levels of antioxidant enzymes, corroborating the high consumption of these proteins. In addition, inflammation and activation of the cholinergic anti-inflammatory pathway was observed by the AChE analysis. Thus, the activation of this pathway can be studied as a possible route to a potential therapy. In addition, the markers AChE, CRP and UA may be used as a focus for the treatment of MetS.