Low vitamin B12 increases risk of gastric cancer: A prospective study of one-carbon metabolism nutrients and risk of upper gastrointestinal tract cancer

Homocystein, Vitamin B12 and Folic Acid as Screening Biomarkers in Early Diagnosis and Gastric Cancer Monitoring

Gastric cancer has been demonstrating a reduction in the number of cases over the past decades, largely attributed to advancements in public health practices and increased accessibility to educational initiatives for the general population. Nevertheless, it persists as the third leading cause of mortality globally among both men and women. These fatalities are typically associated with delayed disease detection. The current study assessed the levels of homocysteine, vitamin B12, and folic acid as a means of establishing a screening biomarker profile that could be integrated into routine testing protocols to facilitate swift diagnosis of the illness. A total of 207 control subjects and 207 individuals with gastric cancer were scrutinized, with biochemical measurements conducted using chemiluminescence for homocysteine, folic acid, and vitamin B12. The two groups were matched based on age, tumor location, subtype, tumor classification, presence of Epstein-Barr Virus infection (EBV), and Helicobacter pylori (H. pylori). Significant statistical variances were identified in the mean levels of the triad of substances among cancer patients when compared to the control group for all corresponding variables. In conclusion, our study indicated that analyzing the triad of homocysteine, vitamin B12, and folic acid holds diagnostic value for gastric cancer and could potentially serve as an effective screening marker for this type of cancer in the future.

Safety and efficacy of vitamin B in cancer treatments: A systematic review

BACKGROUND

With rising rates of complementary and alternative medicine use, the exploration of complementary and alternative medicine integration into oncology treatments is becoming increasingly prevalent. Vitamin B compounds including B1, B2, B3, B5, B6, B9, and B12, have all been proposed as potentially beneficial in cancer prevention and treatment as well as side effect management; however, many studies contain contradicting evidence regarding the utility of B vitamins within oncology. Thus, the aim of this study was to evaluate the safety and efficacy of Vitamin B supplementation in the oncology setting.

DESIGN

A systematic review was conducted following The Preferred Reporting Items for Systematic Reviews and Meta-Analyses-Scoping Reviews guidelines, using pre-specified search terms in PubMed to include randomized control trials, clinical trials, and case studies. Two reviewers independently reviewed titles, abstracts, and full-text articles for inclusion, with a third reviewer resolving conflicts, before the included articles underwent data extraction and quality appraisal. Data extraction was conducted through COVIDENCE, which was used to manage and track the data during the search process.

RESULTS

Out of 694 articles initially identified, 25 articles met the inclusion criteria and were included in the review. Designs of the studies varied, including randomized control trials, clinical trials, and case/cohort studies. The impact of vitamin supplementation on cancer risk varied. Several studies found that certain B vitamin supplementation lowered cancer risk: B9 and B6 in nasopharyngeal carcinoma (n  =  1200 patients) and in pancreatic cancer (n  =  258 patients); B3 in hepatocellular carcinoma (n  =  494,860 patients); B6 in breast cancer (n  =  27,853 patients); and B9 in BRCA1-positive breast cancer (n  =  400 patients). However, some studies found that certain B vitamin supplementation increased the risk or negative outcomes of cancer: B6 during nasopharyngeal carcinoma treatment (n  =  592 patients); B6 in risk of hepatocellular carcinoma (n  =  494,860 patients); and B9 plasma levels in breast cancer (n  =  164 patients). Due to the many adverse effects that occur in cancer treatment, the effectiveness of Vitamin B supplementation in alleviating adverse effects was evaluated. In two separate studies, Vitamin B6 and Vitamin B12 supplementation with acupuncture was found to be effective as adjunct therapies aimed to reduce chemotherapy-induced peripheral neuropathy (n  =  23 patients and n  =  104 patients, respectively). No significant findings were established regarding B vitamin supplementation in chemotherapy-induced hand-foot syndrome.

CONCLUSIONS

In this systematic review we concluded that B vitamin supplements have varying data regarding safety and efficacy in cancer. Taking into account the etiology of the cancer, the specific B-vitamin, and the presence of any side effects could help guide utilization of the data found in this review. Large, randomized controlled trials are needed to confirm these findings among various cancer diagnoses and stages. Given the widespread utilization of supplements, healthcare providers should understand the safety and efficacy of vitamin B supplementation to address questions that arise in caring for those with cancer.

Discovery and characterization of natural product luteolin as an effective inhibitor of human pyridoxal kinase

Pyridoxal kinase (PDXK) is an essential enzyme in the synthesis of pyridoxal 5-phosphate (PLP), the active form of vitamin B6, which plays a pivotal role in maintaining the enzyme activity necessary for cell metabolism. Thus, PDXK has garnered attention as a potential target for metabolism regulation and tumor therapy. Despite this interest, existing PDXK inhibitors have faced limitations, including weak suppressive activity, unclear mechanisms of action, and associated toxic side effects. In this study, we present the discovery of a novel PDXK inhibitor, luteolin, through a high-throughput screening approach based on enzyme activity. Luteolin, a natural product, exhibits micromolar-level affinity for PDXK and effectively inhibits the enzyme's activity in vitro. Our crystal structures reveal that luteolin occupies the ATP binding pocket through hydrophobic interactions and a weak hydrogen bonding pattern, displaying reversible characteristics as confirmed by biochemical assays. Moreover, luteolin disrupts vitamin B6 metabolism by targeting PDXK, thereby inhibiting the proliferation of leukemia cells. This research introduces a novel screening method for identifying high-affinity and potent PDXK inhibitors and sheds light on clarification of the structural mechanism of PDXK-luteolin for subsequent structure optimization of inhibitors.

Association between Vitamin B6 and Risk of Gastric Cancer: A Systematic Review and Meta-Analysis of Epidemiological Studies

Inconsistent findings have emerged from epidemiological research investigating the association between vitamin B6 and the risk of gastric cancer. To obtain a more precise assessment, we conducted a comprehensive search of published data and performed a meta-analysis. PubMed, Web of Science, EMBASE and Cochrane Library databases were systematically searched. A total of 12 studies (5 prospective cohort and 7 case-control studies) involving 5,692 cases and 814,157 participants were included in the meta-analysis. The results showed that high intake of vitamin B6 may reduce the odds of gastric cancer (OR = 0.83, 95% CI: 0.73-0.95, p = 0.006). However, this association was only observed in the case-control studies (OR = 0.68, 95% CI: 0.51-0.89, p = 0.006) but not in the cohort studies (RR = 1.01, 95% CI: 0.94-1.08, p = 0.819). Additionally, the negative association between vitamin B6 intake and gastric cancer risk was found in the United States of America (OR = 0.71, 95% CI: 0.62-0.82, p = 10-4), but not in Europe (OR = 0.88, 95% CI: 0.74-1.05, p = 0.169) or the other regions (OR = 0.86, 95% CI: 0.66-1.13, p = 0.280). In conclusion, there is not sufficient evidence to assume that vitamin B6 intake is associated with gastric cancer risk, which needs further confirmation.

The effect of vitamin B12 on DNA adduction by styrene oxide, a genotoxic xenobiotic

Vitamin B12 (cyano- or hydroxo-cobalamin) acts, via its coenzymes, methyl- and adenosyl-cobalamin, as a partner for enzymatic reactions in humans catalysed by methionine synthase and methylmalonyl-CoA mutase. As well as its association with pernicious anaemia, human B12 deficiency may also be a risk factor for neurological illnesses, heart disease and cancer. In the present work the effect of vitamin B12 (hydroxocobalamin) on the formation of DNA adducts by the epoxide phenyloxirane (styrene oxide), a genotoxic metabolite of phenylethene (styrene), has been studied using an in vitro model system. Styrene was converted to its major metabolite styrene oxide as a mixture of enantiomers using a microsomal fraction from the livers of Sprague-Dawley rats with concomitant inhibition of epoxide hydrolase. However, microsomal oxidation of styrene in the presence of vitamin B12 gave diastereoisomeric 2-hydroxy-2-phenylcobalamins. The quantitative formation of styrene oxide-DNA adducts was investigated using 2-deoxyguanosine or calf thymus DNA in the presence or absence of vitamin B12. Microsomal incubations containing either deoxyguanosine or DNA in the absence of vitamin B12 gave 2-amino-7-(2-hydroxy-1-phenylethyl)-1,7-dihydro-6H-purin-6-one [N7-(2-hydroxy-1-phenylethyl)-guanine], and 2-amino-7-(2-hydroxy-2-phenylethyl)-1,7-dihydro-6H-purin-6-one [N7-(2-hydroxy-2-phenylethyl)guanine] as the principal adducts. With deoxyguanosine the level of formation of guanine adducts was ca. 150 adducts/106 unmodified nucleoside. With DNA the adduct level was 36 pmol/mg DNA (ca. 1 adduct/0.83 × 105 nucleotides). Styrene oxide adducts from deoxyguanosine or DNA were not detected in microsomal incubations of styrene in the presence of vitamin B12. These results suggest that vitamin B12 could protect DNA against genotoxicity due to styrene oxide and other xenobiotic metabolites. However, this potential defence mechanism requires that the 2-hydroxyalkylcobalamins derived from epoxides are not 'anti-vitamins' and ideally liberate, and therefore, recycle vitamin B12. Otherwise, depletion of vitamin B12 leading to human deficiency could increase the risk of carcinogenesis initiated by genotoxic epoxides.

Effects of folic acid supplementation on chronic atrophic gastritis based on MTHFR C677T polymorphism

BACKGROUND

It has been shown the methylenetetrahydrofolate reductase (MTHFR) 677TT (rs 1801133) genotype predicts histopathological alterations in the incisura of patients with chronic atrophic gastritis (CAG). MTHFR is a crucial enzyme in fatty acid (FA) metabolism. This study aimed to evaluate the influence of FA supplementation in CAG patients without Helicobacter pylori infection and the MTHFR C677T (rs 1801133) genotype as a potential CAG predictor.

METHODS

A total of 96 CAG patients, aged 21 to 72 years old, were enrolled in this study. After 6 months of treatment, histopathological outcomes were compared among patients treated with weifuchun (WFC) (1.44 g 3 times per os per day), those treated with WFC and FA (5 mg once daily), and those treated with WFC, FA, and vitamin B12 (VB12) (0.5 mg 3 times per day) based on the Operative Link on Gastritis/Intestinal Metaplasia assessment staging systems.

RESULTS

Atrophic lesions in patients treated with WFC and FA improved more than in patients treated only with WFC therapy (78.1% vs 53.3%, P = .04). Atrophic or intestinal metaplasia (IM) lesions in the incisura of patients with the TT genotype were better than those in patients with the CC/CT genotype (P = .02).

CONCLUSION

The treatment of CAG patients with 5 mg of FA supplements daily for 6 months improved their gastric atrophy status, especially for the Operative Link on Gastritis/Intestinal Metaplasia assessment stages I/II. Moreover, our study is the first to reveal that patients with the MTHFR 677TT genotype require more timely and effective FA treatment than those with the CC/CT genotype.

Cancer Progress and Priorities: Gastric Cancer

Gastric cancer, the fifth leading cause of cancer worldwide, is estimated to be responsible for approximately 1.4% of all new cancers and 1.8% of all cancer-related deaths in the United States. Despite declining incidence rates and improved survival rates, however, gastric cancer continues to disproportionately affect racial and ethnic minorities and individuals of lower socioeconomic status at higher rates than the general population. To improve outcomes globally and address disparities within the United States, continued improvements are needed in risk factor modification and biomarker development and to improve access to existing preventative measures such as genetic testing and H. pylori eradication testing, in addition to expanding upon current clinical guidelines for premalignant disease to address gaps in endoscopic surveillance and early detection.

Genetic Polymorphisms of Gene Methionine Synthase Reductase (MTRR) and Risk of Urinary Bladder Cancer

Methionine synthase reductase (MTRR) gene involved in the signaling for production of enzyme called methionine synthase reductase that use for the synthesis of methionine, which further used in DNA replication and repair. Genetic variation in MTRR gene may alter the susceptibility of developing urinary bladder cancer. The present study undertaken to identify the contribution of genetic polymorphisms in the MTRR gene on the selected polymorphic sites including c.66A>G and c.524C>T towards urinary bladder cancer risk. Direct-DNA sequencing method was applied for the observation of genotyping distribution of MTRR c.66A>G and c.524C>T polymorphisms in 232 histopathological confirmed cases of transitional cell carcinoma (TCC) of urinary bladder cancer and 250 age-, sex- and ethnicity-matched cancer free controls. With significant difference (p = 0.05) of genotype analysis further corresponding Odds ratio (OR) and 95% confidence interval (CI) were calculated. Multivariable logistic regression analysis was applied for adjusting significant confounder variables. Haploview software (version 4.2) was used to perform pairwise Linkage Disequilibrium (LD) analysis. Age (p = 0.01), Habit of smoking (p = 0.05), tobacco consumption (p = 0.001) and diet (p = 0.02) were significantly differed between cases and controls. Both the MTRR substitution showed higher risk of developing urinary bladder cancer (p = <0.001), although this effect alters in multivariable logistic regression analysis in a protective association for both the substitution. No LD observed between the c.66A>G and c.524C>T substitutions. In conclusion, MTRR c.66A>G and c.524C>T substitutions showed a joint effect with the other associated risk factors. Further studies with a greater number of subjects of different ethnicity and polymorphisms are recommended for the better understanding urinary bladder cancer etiology and to screen the population who are at higher risk of developing urinary bladder cancer.

An overview of vitamins as epidrugs for colorectal cancer prevention

Gene expression altering epigenomic modifications such as DNA methylation, histone modification, and chromosome remodeling is crucial to regulating many biological processes. Several lifestyle factors, such as diet and natural, bioactive food compounds, such as vitamins, modify epigenetic patterns. However, epigenetic dysregulation can increase the risk of many diseases, including cancer. Various studies have provided supporting and contrasting evidence on the relationship between vitamins and cancer risk. Though there is a gap in knowledge about whether dietary vitamins can induce epigenetic modifications in the context of colorectal cancer (CRC), the possibility of using them as epidrugs for CRC treatment is being explored. This is promising because such studies might be informative about the most effective way to use vitamins in combination with DNA methyltransferase inhibitors and other approved therapies to prevent and treat CRC. This review summarizes the available epidemiological and observational studies involving dietary, circulating levels, and supplementation of vitamins and their relationship with CRC risk. Additionally, using available in vitro, in vivo, and human observational studies, the role of vitamins as potential epigenetic modifiers in CRC is discussed. This review is focused on the action of vitamins as modifiers of DNA methylation because aberrant DNA methylation, together with genetic alterations, can induce the initiation and progression of CRC. Although this review presents some studies with promising results, studies with better study designs are necessary. A thorough understanding of the underlying molecular mechanisms of vitamin-mediated epigenetic regulation of CRC genes can help identify effective therapeutic targets for CRC prevention and treatment.

The Impact of a Vegan Diet on Many Aspects of Health: The Overlooked Side of Veganism

Vegetarianism in any of its various forms, particularly veganism, has been increasing in popularity over the past few years, especially among the young population in the United States. While several studies have shown that a vegan diet (VD) decreases the risk of cardiometabolic diseases, such as cardiovascular disease, type 2 diabetes mellitus, obesity, and non-alcoholic fatty liver disease, veganism has been associated with adverse health outcomes, namely, nervous, skeletal, and immune system impairments, hematological disorders, as well as mental health problems due to the potential for micro and macronutrient deficits. The goal of this review article is to discuss the current literature on the impact and long-term consequences of veganism on vulnerable populations, including children, adolescents, pregnant and breastfeeding women, and fetal outcomes in strict vegan mothers. It also focuses on the many deficiencies of the vegan diet, especially vitamin B12, and the related increased risk of malignancies.

Circulating Proteins and Metabolite Biomarkers in Gastric Cancer: A Systematic Review and Meta-analysis

BACKGROUND

Gastric cancer (GC) is often diagnosed at an advanced stage and thus patients have a poor prognosis. This implies that early detection of this cancer will improve patient prognosis and survival. This systematic review explored the association of circulating protein and metabolite biomarkers with GC development.

METHODS

A literature search was conducted until November 2021 on Medline, Embase, Cochrane library, and Web of Science databases. Studies were included if they assessed circulating proteins and metabolites in blood, urine, or saliva and determined their association with GC risk. Quality of identified studies was determined using the Newcastle-Ottawa scale for cohort studies. Random and fixed effects meta-analyses were performed to calculate pooled odds ratio.

RESULTS

A total of 53 studies were included. High levels of anti-Helicobacter pylORi IgG levels, pepsinogen I (PGI) <30 µg/L and serum pepsinogen I/ pepsinogen II (PGI/II) ratio<3 were positively associated with risk of developing GC (pooled odds ratio (OR): 2.70; 95% CI: 1.44-5.04, 5.96, 95% CI: 2.65-13.42 and 4.43; 95% CI: 3.04-6.47). In addition, an inverse relationship was found between ferritin, iron and transferrin levels and risk of developing GC (OR: 0.62; 95% CI: 0.38-1,0.97; 95% CI: 0.94-1 and 0.85; 95% CI: 0.76-0.94). However, there was no association between levels of glucose, cholesterol, vitamin C, vitamin B12, vitamin A, α-Carotene, β-Carotene, α-Tocopherol, γ-Tocopherol, and GC risk.

CONCLUSION

The pooled analysis demonstrated that high levels of anti-Helicobacter pylORi IgG, PGI<30µg/L and serum PGI/II ratio <3 and low levels of ferritin, iron and transferrin were associated with risk of GC.

The Prognostic Value of the GNRI in Patients with Stomach Cancer Undergoing Surgery

Malnutrition often induces an adverse prognosis in cancer surgery patients. The elderly nutrition risk index (GNRI) is an example of the objective indicators of nutrition-related risks. We performed a meta-analysis to thoroughly examine the evidence for the GNRI in predicting the outcomes of patients undergoing stomach cancer surgery. Eligible articles were retrieved using PubMed, the Cochrane Library, EMBASE, and Google Scholar by 24 October 2022. The clinical outcomes were overall survival (OS), cancer-specific survival (CSS), and post-operative complications. A total of 11 articles with 5593 patients were included in this meta-analysis. The combined forest plot showed that for every unit increase in the preoperative GNRI score in patients with stomach cancer, their postoperative mortality was reduced by 5.6% (HR: 0.944; 95% CI: 0.933−0.956, p < 0.001). The pooled results also demonstrated that a low GNRI was correlated with poor OS (HR: 2.052; 95% CI: 1.726−2.440, p < 0.001) and CSS (HR: 1.684; 95% CI: 1.249−2.270, p = 0.001) in patients who underwent stomach cancer surgery. Postoperative complications were more likely to occur in patients with a low GNRI, as opposed to those with a high GNRI (OR: 1.768; 95% CI: 1.445−2.163, p < 0.001). There was no evidence of significant heterogeneity, and the sensitivity analysis supported the stability and dependability of the above results. the GNRI is a valuable predictor of long-term outcomes and complications in stomach cancer patients undergoing surgery.

Advances in highly active one-carbon metabolism in cancer diagnosis, treatment and drug resistance: A systematic review

STUDY BACKGROUND OBJECTIVES

Cancer poses a significant health concern as it is incurable. Every year, research on how to treat and eradicate this chronic condition is done. This systematic review will unmask the recent developments concerning highly active 1C metabolism with regard to cancer diagnosis, treatment, and drug resistance. The significance of this study is rolling out evidence-based evidence on the importance of one-carbon metabolism in cancer diagnosis and treatment.

METHODS

Eight randomized controlled trials (RCTs) were reviewed from five electronic databases - EMBASE, Scopus Review, Google Scholar, Web of Science, and PubMed. Outcomes from the eight studies were analyzed to paint a picture of the topic in question. While the Preferred Reporting Items for Systematic Reviews and Meta-Analysis' (PRISMA) protocol guided the initial literature search, The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach informed quality assessments of the eligible studies.

CONCLUSION

Since its emergence in the 1980s, 1C metabolism has been investigated and broadened to capture essential aspects of cancer treatment, diagnosis, and drug resistance. The review found that metabolites like folic acid could be used to detect different types of cancer. The metabolic pathways could induce tumorigenesis and DNA methylation, hence drug resistance.

SYSTEMATIC REVIEW REGISTRATION

https://inplasy.com/projects/, identifier INPLASY2022110099.

Association between Vitamin B12 and Risk of Gastric Cancer: A Systematic Review and Meta-Analysis of Epidemiological Studies

Epidemiological studies focusing on the association between vitamin B₁₂ and gastric cancer risk reported inconsistent findings. We conducted a systematic review and meta-analysis to assess the relationship. PubMed (Medline), Web of science and EMBASE databases were systematically searched. A total of nine studies involving 3,494 cases of with gastric cancer and 611,638 participants were included. The result showed that there is no significant association between vitamin B₁₂ intake and the risk of gastric cancer (OR = 0.88, 95% CI: 0.69-1.12, P = 0.303). Nevertheless, high intake of vitamin B₁₂ might decrease the risk of gastric cancer in Helicobacter pylori (Hp)-negative people (OR = 0.83, 95% CI: 0.62-0.99, P = 0.044), but increase the cancer risk in Hp-positive populations (OR = 1.66, 95% CI: 1.27-2.16, P = 10^-4). Additionally, further analysis indicated that excessive vitamin B₁₂ might increase the risk of non-cardia gastric cancer (OR = 1.15, 95% CI: 1.01-1.33, P = 0.006). A negative association between vitamin B₁₂ intake and gastric cancer risk was found in nonsmokers (OR = 0.83, 95% CI: 0.71-0.96, P = 0.012) but not in smokers (OR = 1.08, 95% CI: 0.71-1.47, P = 0.619). In conclusion, although we found no convincing evidence that vitamin B₁₂ intake is associated with the risk of gastric cancer, it is important to maintain the relative stability of vitamin B₁₂ for people with Hp infection.

The exposome in practice: an exploratory panel study of biomarkers of air pollutant exposure in Chinese people aged 60-69 years (China BAPE Study)

The exposome overhauls conventional environmental health impact research paradigms and provides a novel methodological framework that comprehensively addresses the complex, highly dynamic interplays of exogenous exposures, endogenous exposures, and modifiable factors in humans. Holistic assessments of the adverse health effects and systematic elucidation of the mechanisms underlying environmental exposures are major scientific challenges with widespread societal implications. However, to date, few studies have comprehensively and simultaneously measured airborne pollutant exposures and explored the associated biomarkers in susceptible healthy elderly subjects, potentially resulting in the suboptimal assessment and management of health risks. To demonstrate the exposome paradigm, we describe the rationale and design of a comprehensive biomarker and biomonitoring panel study to systematically explore the association between individual airborne exposure and adverse health outcomes. We used a combination of personal monitoring for airborne pollutants, extensive human biomonitoring, advanced omics analysis, confounding information, and statistical methods. We established an exploratory panel study of Biomarkers of Air Pollutant Exposure in Chinese people aged 60-69 years (China BAPE), which included 76 healthy residents from a representative community in Jinan City, Shandong Province. During the period between September 2018 and January 2019, we conducted prospective longitudinal monitoring with a 3-day assessment every month. This project: (1) leveraged advanced tools for personal airborne exposure monitoring (external exposures); (2) comprehensively characterized biological samples for exogenous and endogenous compounds (e.g., targeted and untargeted monitoring) and multi-omics scale measurements to explore potential biomarkers and putative toxicity pathways; and (3) systematically evaluated the relationships between personal exposure to air pollutants, and novel biomarkers of exposures and effects using exposome-wide association study approaches. These findings will contribute to our understanding of the mechanisms underlying the adverse health impacts of air pollution exposures and identify potential adverse clinical outcomes that can facilitate the development of effective prevention and targeted intervention techniques.

Molecular characterization of metabolic subtypes of gastric cancer based on metabolism-related lncRNA

Increasing evidence has demonstrated that lncRNAs are critical regulators in diverse biological processes, but the function of lncRNA in metabolic regulation remains largely unexplored. In this study, we evaluated the association between lncRNA and metabolic pathways and identified metabolism-related lncRNAs. Gastric cancer can be mainly subdivided into 2 clusters based on these metabolism-related lncRNA regulators. Comparative analysis shows that these subtypes are found to be highly consistent with previously identified subtypes based on other omics data. Functional enrichment analysis shows that they are enriched in distinct biological processes. Mutation analysis shows that ABCA13 is a protective factor in subtype C1 but a risk factor in C2. Analysis of chemotherapeutic and immunotherapeutic sensitivity shows that these subtypes tend to display distinct sensitivity to the same chemical drugs. In conclusion, these findings demonstrated the significance of lncRNA in metabolic regulation. These metabolism-related lncRNA regulators can improve our understanding of the underlying mechanism of lncRNAs and advance the research of immunotherapies in the clinical management of gastric cancer.

Interplay and cooperation of Helicobacter pylori and gut microbiota in gastric carcinogenesis

Chronic Helicobacter pylori infection is a critical risk factor for gastric cancer (GC). However, only 1–3 % of people with H. pylori develop GC. In gastric carcinogenesis, non-H. pylori bacteria in the stomach might interact with H. pylori. Bacterial dysbiosis in the stomach can strengthen gastric neoplasia development via generating tumor-promoting metabolites, DNA damaging, suppressing antitumor immunity, and activating oncogenic signaling pathways. Other bacterial species may generate short-chain fatty acids like butyrate that may inhibit carcinogenesis and inflammation in the human stomach. The present article aimed at providing a comprehensive overview of the effects of gut microbiota and H. pylori on the development of GC. Next, the potential mechanisms of intestinal microbiota were discussed in gastric carcinogenesis. We also disserted the complicated interactions between H. pylori, intestinal microbiota, and host in gastric carcinogenesis, thus helping us to design new strategies for preventing, diagnosing, and treating GC.

The weak correlation between serum vitamin levels and chronic kidney disease in hospitalized patients: a cross-sectional study

Background

Chronic kidney disease (CKD) has become a global public health problem. Accumulating evidence suggested that vitamins play important roles in the progression of CKD.

Methods

A cross-sectional study was conducted to investigate the vitamin status of patients with CKD at stage 1–5. The serum concentrations of 9 vitamins, vitamin A, B1, B2, B6, B9, B12, C, D, and E were measured by electroanalytical method with a Multi-Vitamin Analyzer. Pearson correlation and multiple linear regression between serum level of vitamins were analyzed.

Results

The median levels of vitamin A, B1, B2, B6, B9, B12, C and E were within the reference ranges or on the borderline. Vitamin D deficiency was found in all patients. Weak correlation was found between vitamin A or vitamin D and estimated glomerular filtration rate (eGFR). The Pearson correlation coefficient were − 0.21766 and 0.19752, respectively. Hypertension, diabetes mellitus, and atherosclerosis were the major comorbidities.

Conclusions

For the first time, the serum levels of 9 vitamins were measured simultaneously in patients with CKD at different stages. Vitamin D deficiency was found in all patients. Weak correlation between vitamin A or vitamin D and eGFR was found.

Genetically predicted circulating B vitamins in relation to digestive system cancers

BACKGROUND

Folate, vitamin B6 and vitamin B12 have been associated with digestive system cancers. We conducted a two-sample Mendelian randomisation study to assess the causality of these associations.

METHODS

Two, one and 14 independent single nucleotide polymorphisms associated with serum folate, vitamin B6 and vitamin B12 at the genome-wide significance threshold were selected as genetic instruments. Summary-level data for the associations of the vitamin-associated genetic variants with cancer were obtained from the UK Biobank study including 367,561 individuals and FinnGen consortium comprising up to 176,899 participants.

RESULTS

Genetically predicted folate and vitamin B6 concentrations were not associated with overall cancer, overall digestive system cancer or oesophageal, gastric, colorectal or pancreatic cancer. Genetically predicted vitamin B12 concentrations were positively associated with overall digestive system cancer (OR_SD, 1.12; 95% CI 1.04, 1.21, p = 0.003) and colorectal cancer (OR_SD 1.16; 95% CI 1.06, 1.26, p = 0.001) in UK Biobank. Results for colorectal cancer were consistent in FinnGen and the combined OR_SD was 1.16 (95% CI 1.08, 1.25, p < 0.001). There was no association of genetically predicted vitamin B12 with any other site-specific digestive system cancers or overall cancer.

CONCLUSIONS

These results provide evidence to suggest that elevated serum vitamin B12 concentrations are associated with colorectal cancer.

A Prospective Investigation of Circulating Metabolome Identifies Potential Biomarkers for Gastric Cancer Risk

BACKGROUND

Metabolomics is widely used to identify potential novel biomarkers for cancer risk. No investigation, however, has been conducted to prospectively evaluate the role of perturbation of metabolome in gastric cancer development.

METHODS

250 incident cases diagnosed with primary gastric cancer were selected from the Shanghai Women's Health and the Shanghai Men's Health Study, and each was individually matched to one control by incidence density sampling. An untargeted global profiling platform was used to measure approximately 1,000 metabolites in prediagnostic plasma. Conditional logistic regression was utilized to generate ORs and P values.

RESULTS

Eighteen metabolites were associated with gastric cancer risk at P < 0.01. Among them, 11 metabolites were lysophospholipids or lipids of other classes; for example, 1-(1-enyl-palmitoyl)-GPE (P-16:0) (OR = 1.56; P = 1.89 × 10^-4). Levels of methylmalonate, a suggested biomarker of vitamin B12 deficiency, was correlated with increased gastric cancer risk (OR = 1.42; P = 0.004). Inverse associations were found for three biomarkers for coffee/tea consumption (3-hydroxypyridine sulfate, quinate and N-(2-furoyl) glycine), although the associations were only significant when comparing cases that were diagnosed within 5 years after the blood collection to matched controls. Most of the identified associations were more profound in women and never smokers than their male or ever smoking counterparts and some with notable significant interactions.

CONCLUSIONS

Our study identified multiple potential risk biomarkers for gastric cancer independent of Helicobacter pylori infection and other major risk factors.

IMPACT

New risk-assessment tools to identify high-risk population could be developed to improve prevention of gastric cancer.See related commentary by Drew et al., p. 1601.

Is There a Carcinogenic Risk Attached to Vitamin B12 Deficient Diets and What Should We Do About It? Reviewing the Facts

The number of individuals partaking in veganism has increased sharply in the last decade. Therefore, it is critical to look at the implications of vegan diets for public health. Although there are multiple health benefits of a vegan diet, studies have also linked the diet with deficiencies in various micronutrients. This study focuses on vitamin B12, because of its critical role in DNA synthesis and methylation. In light of these connections, a critical review of recent scientific literature is conducted to understand the effects of a B12 deficient diet on the genome and epigenome, and whether it can give rise to cancer. It is observed that a B12 deficiency leads to increased uracil misincorporation, leading to impaired DNA synthesis and genomic instability. The deficiency also leads to global hypomethylation of DNA, a hallmark of early carcinogenesis. The findings of this study highlight the need for increased awareness among vegans to ensure adequate B12 intake through supplementation or consumption of fortified products as a preventative measure. Additionally, the biofortification of staple crops and an improved version of fermented products with increased B12 content can be developed when inadequate intake seems otherwise inevitable.

Associations of one-carbon metabolism-related gene polymorphisms with breast cancer risk are modulated by diet, being higher when adherence to the Mediterranean dietary pattern is low

PURPOSE

Breast cancer is more likely attributed to a combination of genetic variations and lifestyle factors. Both one-carbon metabolism and diet-related factors could interfere with the carcinogenesis of breast cancer (BC), but whether diet consumed underlie a specific metabolism pathway could influence the impact of genetic variants on breast cancer risk remains equivocal.

METHODS

A case-control study of the Chinese female population (818 cases, 935 controls). 13 SNPs in eight one-carbon metabolism-related genes (MTHFD1, TYMS, MTRR, MAT2B, CDO1, FOLR1, UNG2, ADA) were performed. Diet was assessed by a validated food-frequency questionnaire. We examined the associations of the adherence to the Mediterranean dietary pattern (MDP) and single-nucleotide polymorphisms (SNPs) of one-carbon metabolism with breast cancer risk. We constructed an aggregate polygenic risk score (PRS) to test the additive effects of genetic variants and analyzed the gene-diet interactions.

RESULTS

High adherence (highest quartile) to the MDP decreased the risk of breast cancer among post- but not premenopausal women, respectively (OR = 0.54, 95% CI = 0.38 to 0.78 and 0.90, 0.53 to 1.53). Neither of the polymorphisms or haplotypes was associated with breast cancer risk, irrespective of menopause. However, a high PRS (highest quartile) was associated with more than a doubling risk in both post- and premenopausal women, respectively (OR = 1.95, 95% CI = 1.32 to 2.87 and 2.09, 1.54 to 2.85). We found a gene-diet interaction with adherence to the MDP for aggregate PRS (P-interaction = 0.000) among postmenopausal women. When adherence to the MDP was low (< median), carries with high PRS (highest quartile) had higher BC risk (OR = 2.80, 95% CI = 1.55 to 5.07) than low PRS (lowest quartile), while adherence to the MDP was high (≥ median), the association disappeared (OR = 1.57, 95% CI = 0.92 to 2.66).

CONCLUSION

High adherence to the MDP may counteract the genetic predisposition associated with one-carbon metabolism on breast cancer risk in postmenopausal women.

Prognostic Significance of Plasma Folate and Cobalamin Concentrations in Non-Muscle-Invasive Bladder Cancer: A Prospective Cohort Study

This cohort study aimed to investigate prognostic significance of plasma folate and cobalamin in non-muscle-invasive bladder cancer (NMIBC). A total of 177 NMIBC patients were followed over a period extending to 6 years. Cox regression models were applied to estimate risks for recurrence and progression according to plasma vitamins tertiles. Compared to first tertile, third tertile of plasma folate [HR (95% CI), 10.5 (1.32-83.4); p = 0.026] was associated, and of plasma cobalamin [2.12 (0.63-7.25); p = 0.116] tended to be associated with higher risk for progression. NIMBC patients with high folate/cobalamin statuses should make the physician more alert for a likely poor outcome.

High expression of TCN1 is a negative prognostic biomarker and can predict neoadjuvant chemosensitivity of colon cancer

Transcobalamin (TCN1) is a vitamin B12 (cobalamin)-binding protein that regulates cobalamin homeostasis. Recent studies and bioinformatic analyses have found that TCN1 is highly expressed in cancer tissues and is associated with tumour aggressiveness and poor prognosis. The present study aimed to detect TCN1 as a novel biomarker for prognosis and chemosensitivity of colon cancer. Next-generation sequencing showed that TCN1 was one of several upregulated mRNAs in colon cancer, which was verified by further bioinformatics analyses. Western blotting (n = 9) and quantitative real time polymerase chain reaction (qRT-PCR, n = 30) revealed that TCN1 was highly expressed in colon cancer tissues at both the protein and mRNA level. A total of 194 cases of colon cancer were examined by immunohistochemistry and revealed that TCN1 expression level was related to advanced stages (P < 0.005). Kaplan-Meier analysis verified that patients with lower TCN1 expression usually had longer overall survival (P = 0.008). In addition, TCN1 was highly expressed in pulmonary metastatic tumour tissues (n = 37, P = 0.025) and exhibited higher levels in right-sided colon cancer than in left-sided colon cancer (P = 0.029). TCN1 expression in specimens that had received neoadjuvant chemotherapy decreased compared with that in colonoscopy biopsy tissues (n = 42, P = 0.009). Further bioinformatics analyses verified that apoptosis pathways might have a role in high TCN1 expression. All the studies revealed that TCN1 expression in colon cancer was significantly associated with malignant biological behaviour. Therefore, TCN1 could be used as a novel biomarker for colon cancer aggressiveness and prognosis and might also be a potential biomarker for predicting neoadjuvant chemosensitivity.

Less is more: Two automated interventions to increase vitamin B12 measurement when long-term proton pump inhibitor and decrease redundant testing

INTRODUCTION

To test the efficacy of two interventions to promote the measurement of serum vitamin B₁₂ (s- vitamin B₁₂) in patients with long-term proton pump inhibitor (PPI) use and to decrease inadequate s-vitamin B₁₂ measurement by implementing a minimum retest interval.

MATERIAL AND METHODS

The Laboratory Information System (LIS) automatically registered s-vitamin B₁₂ when not ordered by General Practitioners to all requests patients with long term (>3years) PPI treatment, and with no s-vitamin B₁₂ testing in the previous year. Through the second intervention, the LIS reported the previous s-vitamin B₁₂ result through an explanatory comment in the report, when the test had been requested in the previous three months. We calculated the new diagnoses of vitamin deficiency (s-vitamin B₁₂ < 200 pg/mL), examined the number of tests needed to detect a new case and investigated the economic cost of each one identified by the intervention. Additionally, we counted the s-vitamin B₁₂ that were requested but not measured, and calculated the savings in reagent.

RESULTS

The strategy added 548 s-vitamin B₁₂ and identified 47 new cases of vitamin B₁₂ deficit. The number of added s-vitamin B₁₂ needed to identify a new case by means of the intervention was 12. The total intervention reagent cost was 1446€, with a cost of 30.7€ per new case. The second intervention avoided unnecessary measurement of 611 tests, with 1613€ savings.

CONCLUSIONS

Through the two automated interventions we improved the diagnosis of vitamin B₁₂ deficiency, and decreased inadequate redundant s-vitamin B₁₂ measurement, cutting unnecessary laboratory costs.

Development of the anti-cancer food scoring system 2.0: Validation and nutritional analyses of quantitative anti-cancer food scoring model

BACKGROUND/OBJECTIVES

We have previously designed the anti-cancer food scoring model (ACFS) 1.0, an evidence-based quantitative tool analyzing the anti-cancer or carcinogenic potential of diets. Analysis was performed using simple quantitative indexes divided into 6 categories (S, A, B, C, D, and E). In this study, we applied this scoring model to wider recipes and evaluated its nutritional relevance.

MATERIALS/METHODS

National or known regional databases were searched for recipes from 6 categories: Korean out-dining, Korean home-dining, Western, Chinese, Mediterranean, and vegetarian. These recipes were scored using the ACFS formula and the nutrition profiles were analyzed.

RESULTS

Eighty-eight international recipes were analyzed. All S-graded recipes were from vegetarian or Mediterranean categories. The median code values of each category were B (Korean home-dining), C (Korean out-dining), B (Chinese), A (Mediterranean), S (vegetarian), and D (Western). The following profiles were correlated (P < 0.05) with ACFS grades in the univariate trend analysis: total calories, total fat, animal fat, animal protein, total protein, vitamin D, riboflavin, niacin, vitamin B₁₂, pantothenic acid, sodium, animal iron, zinc, selenium, and cholesterol (negative trends), and carbohydrate rate, fiber, water-soluble fiber, vitamin K, vitamin C, and plant calcium (positive trends). Multivariate analysis revealed that animal fat, animal iron, and niacin (negative trends) and animal protein, fiber, and vitamin C (positive trends) were statistically significant. Pantothenic acid and sodium showed non-significant negative trends (P < 0.1), and vitamin B₁₂ showed a non-significant positive trend.

CONCLUSION

This study provided a nutritional basis and extended the utility of ACFS, which is a bridgehead for future cancer-preventive clinical trials using ACFS.

Genetic Association of Plasma Homocysteine Levels with Gastric Cancer Risk: A Two-Sample Mendelian Randomization Study

BACKGROUND

The association of plasma homocysteine level (PHL) with gastric cancer risk was reported in observational studies. However, the causality is challenging due to confounding factors and the lack of evidence from well-designed cohort studies. Herein, we performed a two-sample Mendelian randomization (MR) analysis to investigate whether PHL is causally related to gastric cancer risk.

METHODS

We performed the MR analysis based on the results from genome-wide association studies consisting of 2,631 patients with gastric cancer and 4,373 controls. An externally weighted genetic risk score (wGRS) was constructed with 15 SNPs with well-established associations with PHL. We utilized logistic regression model to estimate associations of PHL-related SNPs and wGRS with gastric cancer risk in total population and in strata by sex, age, and study site, in addition to a series of sensitivity analyses.

RESULTS

High genetically predicted PHL was associated with an increased gastric cancer risk (per SD increase in the wGRS: OR = 1.07; 95% confidence interval, 1.01-1.12; P = 0.011), which was consistent in sensitivity analyses. Subgroup analyses provided evidence of a stronger association with gastric cancer risk in women than in men. MR-Egger and weighted median regression suggested that potentially unknown pleiotropic effects were not biasing the association between PHL and gastric cancer risk.

CONCLUSIONS

These results revealed that genetically predicted high PHL was associated with an increased gastric cancer risk, suggesting that high PHL may have a causal role in the etiology of gastric cancer.

IMPACT

These findings provide causal inference for PHL on gastric cancer risk, suggesting a causal role of high PHL in the etiology of gastric cancer.

Association of dietary patterns and endoscopic gastric mucosal atrophy in an adult Chinese population

Atrophy gastritis harbor a high risk for the development of dysplasia and gastric cancer. The study investigated the relationships of specific dietary patterns and endoscopic gastric mucosal atrophy. In this cross-sectional study, we enrolled 574 consecutive outpatients who were diagnosed as chronic gastritis according to endoscopic examination. Dietary intakes of study individuals was assessed using the semi-quantitative food group frequency questionnaire. Logistic regression analyses were used to evaluate the relationship between dietary patterns and endoscopic gastric mucosal atrophy adjusted for potential confounders. A total of 574 participants were included, 286 with endoscopic gastric mucosal atrophy. Three dietary patterns were identified by factor analysis. “Alcohol and fish” (tertile 1 vs. tertile 3: adjusted odds ratio = 1.85, 95% confidence interval: 1.06–3.22) and “coarse cereals” (tertile 1 vs. tertile 3: adjusted odds ratio = 2.05, 95% confidence interval: 1.24–3.39) were associated with an increased risk for endoscopic gastric mucosal atrophy but a “traditional” pattern was not. Dietary pattern was not associated with gastric mucosal atrophy in women or in participants with H. pylori infection. A high adherence to both “Alcohol and Fish” and “Coarse cereals” dietary patterns seem to be associated with higher odds of endoscopic gastric mucosal atrophy in men and in patients without H. pylori infection. Further prospective cohort studies needed to confirm these findings.

High frequency of anti-parietal cell antibody (APCA) and intrinsic factor blocking antibody (IFBA) in individuals with severe vitamin B12 deficiency – an observational study in primary care patients

Background

Vitamin B12 deficiency is common worldwide and is also linked to several diseases including autoimmune atrophic gastritis (AAG). The presence of anti-parietal cell antibodies (APCA) and/or intrinsic factor blocking antibodies (IFBA) is indicative of AAG that may develop into pernicious anemia. Both conditions are known to be associated with an increased risk of gastric carcinoma. The aim of this study was to estimate the frequency of individuals positive for APCA and IFBA antibodies in primary care patients with severe vitamin B12 deficiency.

Methods

An observational study was designed and 5468 consecutive patients from primary care with a request for vitamin B12 status were included and add-on testing for APCA and IFBA that were automatically registered if severe vitamin B12 deficiency was identified (<73.8 pmol/L). For patients included in the intervention, study demographic data, mean corpuscular volume (MCV) and hemoglobin values were collected.

Results

Seventy-seven patients with severe vitamin B12 deficiency were identified and out of these 44 (57%) presented with antibodies to APCA and 11 (14%) to IFBA, 25 (32.5%) had anemia, and 25 (32.5%) had macrocytosis. The majority of APCA and/or IFBA positive patients were found in the age group >70 years. Both anemia and macrocytosis were more common among APCA positive patients but the association was not statistically significant, neither was the correlation between IFBA status and anemia and/or macrocytosis. Among the patients with anemia, 10 (39%) had macrocytosis, although the rate of macrocytosis among patients with or without anemia did not differ significantly.

Conclusions

The automated analysis strategy of measuring antibodies to APCA and IFBA in patients with severe vitamin B12 deficiency, efficiently detected positivity in more than 60% the patients. The result point to the presence of a high rate of otherwise undetected AAG and the potential clinical utility of APCA and IFBA as markers in primary care.

Generating the Blood Exposome Database Using a Comprehensive Text Mining and Database Fusion Approach

BACKGROUND

Blood chemicals are routinely measured in clinical or preclinical research studies to diagnose diseases, assess risks in epidemiological research, or use metabolomic phenotyping in response to treatments. A vast volume of blood-related literature is available via the PubMed database for data mining.

OBJECTIVES

We aimed to generate a comprehensive blood exposome database of endogenous and exogenous chemicals associated with the mammalian circulating system through text mining and database fusion.

METHODS

Using NCBI resources, we retrieved PubMed abstracts, PubChem chemical synonyms, and PMC supplementary tables. We then employed text mining and PubChem crowdsourcing to associate phrases relating to blood with PubChem chemicals. False positives were removed by a phrase pattern and a compound exclusion list.

RESULTS

A query to identify blood-related publications in the PubMed database yielded 1.1 million papers. Matching a total of 15 million synonyms from 6.5 million relevant PubChem chemicals against all blood-related publications yielded 37,514 chemicals and 851,999 publications records. Mapping PubChem compound identifiers to the PubMed database yielded 49,940 unique chemicals linked to 676,643 papers. Analysis of open-access metabolomics papers related to blood phrases in the PMC database yielded 4,039 unique compounds and 204 papers. Consolidating these three approaches summed up to a total of 41,474 achiral structures that were linked to 65,957 PubChem CIDs and to over 878,966 PubMed articles. We mapped these compounds to 50 databases such as those covering metabolites and pathways, governmental and toxicological databases, pharmacology resources, and bioassay repositories. In comparison, HMDB, the Human Metabolome Database, links 1,075 compounds to blood-related primary publications.

CONCLUSION

This new Blood Exposome Database can be used for prioritizing chemicals for systematic reviews, developing target assays in exposome research, identifying compounds in untargeted mass spectrometry, and biological interpretation in metabolomics data. The database is available at http://bloodexposome.org. https://doi.org/10.1289/EHP4713.

Homocysteine and Digestive Tract Cancer Risk: A Dose-Response Meta-Analysis

Background

Homocysteine, a key component in one-carbon metabolism, is of great importance in remethylation. Many epidemiologic studies have assessed the association between homocysteine and risk of digestive tract cancer, but the results are inconsistent.

Objective

The objective of our meta-analysis is to assess the association between homocysteine and digestive tract cancer risk.

Methods

Comprehensive searches were performed on the PubMed, Embase, Cochrane, and Web of Science databases up to September 25, 2018, to identify relevant studies. Thirteen studies were included in the meta-analysis. Odds ratios (ORs) and their corresponding 95% confidence intervals (95% CIs) were used to estimate the strength of the relationship between homocysteine and the risk of digestive tract cancer.

Results

The pooled OR of digestive tract cancer risk for patients with the highest categories of blood homocysteine levels versus the lowest categories was 1.27 (95% CI, 1.15, 1.39) with no significant heterogeneity observed (P = 0.798, I ² = 0.0%). Moreover, the dose-response analysis revealed that each 5μmol/L increase in homocysteine increased the incidence of digestive tract cancer by 7%.

Conclusion

Generally, our results indicated that elevated homocysteine was associated with higher risk of digestive tract cancer. That is, homocysteine concentration may be a potential biomarker for occurrence of digestive tract cancer.

Incidence of cancer (other than gastric cancer) in pernicious anaemia: A systematic review with meta-analysis

BACKGROUND

Pernicious anaemia (PA) is associated with increased gastric cancer risk, but the evidence is conflicting regarding the associated risk of other cancers.

AIM

To systematically determine the incidence rates of gastro-intestinal cancers other than gastric cancers (GI-other-than-GC) and non-gastrointestinal cancers (non-GIC) in PA adults, globally and per tumour site, and the risk associated with PA for GI-other than GC and non-GIC.

METHODS

Studies of PA patients reporting the incidence of GI-other-than-GCs and non-GICs were identified with MEDLINE (PubMed)-EMBASE (from first date available to April 2017). A meta-analysis of annual cancer incidence rates was performed. The outcome was the cumulative incidence of GI-other-than-GCs and non-GICs (ratio between the numbers of new cancer cases identified during the follow-up period and the number of PA patients) and the incidence rate expressed as the rate of events-per-time-unit (person-years).

RESULTS

Of 82,257 PA patients, the pooled incidence rates/100 person-years for non-GCs and non-GICs of 0.27 (95% CI:0.16-0.42) and 0.23 (95% CI:0.22-0.25) were calculated by meta-analysis. Compared to the GLOBOCAN data for the general population from the countries of the included studies, the meta-analysis showed an overall relative risk (RR) of cancer in PA of 0.68 (95% CI:0.48-0.95). PA patients had a lower RR of colorectal, breast, liver, oesophageal, lung, thyroid, ovary, non-melanoma skin and kidney cancers but had a higher RR of biliary tract cancer (1.81:1.21-2.70), multiple myeloma (2.83:1.76-4.55), Hodgkin's lymphoma (3.0:1.35-6.68), non-Hodgkin's lymphoma (2.08: 1.58-2.75), and leukaemia (1.56:1.16-2.12).

CONCLUSION

An overall lower RR of cancers-other-than-gastric-cancer in PA patients but an increased RR of biliary tract cancers and haematological malignancies was observed.

Discriminating gastric cancer and gastric ulcer using human plasma amino acid metabolic profile

Patients with gastric ulcer (GU) have a significantly higher risk of developing gastric cancer (GC), especially within 2 years after diagnosis. The main way to improve the prognosis of GC is to predict the tumorigenesis and metastasis in the early stage. The objective of this study was to demonstrate the ability of human plasma amino acid metabolic profile for discriminating GC and GU. In this study, we first used liquid chromatography-tandem mass spectrometry technique to characterize the plasma amino acid metabolism in GC and GU patients. Plasma samples were collected from 84 GC patients and 82 GU patients, and 22 amino acids were detected in each patient. Partial least squares-discriminant analysis model was performed to analyze the data of these amino acids. We observed seven differential amino acids between GC and GU. A regression analysis model was established using these seven amino acids. Finally, a panel of five differential amino acids, including glutamine, ornithine, histidine, arginine and tryptophan, was identified for discriminating GC and GU with good specificity and sensitivity. The receiver operating characteristic curve was used to evaluate diagnostic ability of the regression model and area under the curve was 0.922. In conclusion, this study demonstrated the potential values of plasma amino acid metabolic profile and metabolomic analysis technique in assisting diagnosis of GC. More studies are needed to highlight the theoretical strengths of metabolomics to understand the potential metabolic mechanisms in GC. © 2018 IUBMB Life, 70(6):553-562, 2018.

Vitamin B12 Deficiency and the Role of Gender: A Cross-Sectional Study of a Large Cohort

Background: Vitamin B12 deficiency is associated with hematological, neurological, and cardiovascular consequences. Epidemiologic data on these related illnesses indicate gender differences. Methods: A cross-sectional study was designed to examine gender differences in vitamin B12 deficiency among a healthy population. Data from healthy individuals aged 18–65, who were provided with a routine medical evaluation during 2000–2014, were retrieved from the medical charts. Individuals with background illnesses and those who had used medications or nutritional supplements were excluded. Vitamin B12 deficiency was defined by 2 cutoff values (206 and 140 pmol/L). The multivariate analysis was adjusted for age, body mass index, estimated glomerular filtration rate, hyperhomocysteinemia, folate deficiency, albumin, and transferrin saturation. Sensitivity analyses were implemented by excluding individuals with anemia, hyperhomocysteinemia, or folate deficiency and by age stratification. Results: In all, 7,963 individuals met the inclusion criteria. Serum vitamin B12 mean levels were 312.36 and 284.31 pmol/L for women and men respectively (p < 0.001). Deficiency prevalence was greater for men (25.5%) in comparison with women (18.9%; p < 0.001). Men were strongly associated with severe deficiency (adjusted OR 2.26; 95% CI 1.43–3.56). Conclusions: Among the healthy population, men are susceptible to vitamin B12 deficiency. This can be explained by neither diet habits nor estrogen effects. Genetic variations are therefore hypothesized to play a role.