Hyperhomocysteinemia is a risk factor for colorectal adenoma in women

Interactions between vitamin B2, the MTRR rs1801394 and MTR rs1805087 genetic polymorphisms, and colorectal cancer risk in a Korean population

OBJECTIVES

We explored whether the association between vitamin B2 and colorectal cancer (CRC) risk could be modified by the MTRR rs1801394 and MTR rs1805087 genetic polymorphisms and examined whether the interaction effects are sex-specific.

METHODS

We performed a case-control study involving 1,420 CRC patients and 2,840 controls from the Korea National Cancer Center. Dietary vitamin B2 intake was assessed using a semiquantitative food frequency questionnaire, and the association with CRC was evaluated. Genotyping was performed using an Illumina MEGA-Expanded Array. For gene-nutrient interaction analysis, pre-matched (1,081 patients and 2,025 controls) and matched (1,081 patients and 1,081 controls) subsets were included. Unconditional and conditional logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

A higher intake of vitamin B2 was associated with a significantly lower CRC risk (OR, 0.65; 95% CI, 0.51 to 0.82; p<0.001). Carriers of at least 1 minor allele of MTRR rs1801394 showed a significantly higher CRC risk (OR, 1.43; 95% CI, 1.12 to 1.83). Males homozygous for the major allele (A) of MTRR rs1801394 and who had a higher intake of vitamin B2 had a significantly lower CRC risk (OR, 0.31; 95% CI, 0.18 to 0.54; p-interaction=0.02). In MTR rs1805087, males homozygous for the major allele (A) and who had a higher vitamin B2 intake had a significantly lower CRC risk (OR, 0.38; 95% CI, 0.25 to 0.60; p-interaction<0.001).

CONCLUSIONS

The MTRR rs1801394 and MTR rs1805087 genetic polymorphisms may modify the association between vitamin B2 and CRC risk, particularly in males. However, further studies are warranted to confirm these interaction results.

Effects of Aerobic Treadmill Training on Oxidative Stress Parameters, Metabolic Enzymes, and Histomorphometric Changes in Colon of Rats with Experimentally Induced Hyperhomocysteinemia

The aim of this study was to investigate the effects of aerobic treadmill training regimen of four weeks duration on oxidative stress parameters, metabolic enzymes, and histomorphometric changes in the colon of hyperhomocysteinemic rats. Male Wistar albino rats were divided into four groups (n = 10, per group): C, 0.9% NaCl 0.2 mL/day subcutaneous injection (s.c.) 2x/day; H, homocysteine 0.45 µmol/g b.w./day s.c. 2x/day; CPA, saline (0.9% NaCl 0.2 mL/day s.c. 2x/day) and an aerobic treadmill training program; and HPA, homocysteine (0.45 µmol/g b.w./day s.c. 2x/day) and an aerobic treadmill training program. The HPA group had an increased level of malondialdehyde (5.568 ± 0.872 μmol/mg protein, p = 0.0128 vs. CPA (3.080 ± 0.887 μmol/mg protein)), catalase activity (3.195 ± 0.533 U/mg protein, p < 0.0001 vs. C (1.467 ± 0.501 U/mg protein), p = 0.0012 vs. H (1.955 ± 0.293 U/mg protein), and p = 0.0003 vs. CPA (1.789 ± 0.256 U/mg protein)), and total superoxide dismutase activity (9.857 ± 1.566 U/mg protein, p < 0.0001 vs. C (6.738 ± 0.339 U/mg protein), p < 0.0001 vs. H (6.015 ± 0.424 U/mg protein), and p < 0.0001 vs. CPA (5.172 ± 0.284 U/mg protein)) were detected in the rat colon. In the HPA group, higher activities of lactate dehydrogenase (2.675 ± 1.364 mU/mg protein) were detected in comparison to the CPA group (1.198 ± 0.217 mU/mg protein, p = 0.0234) and higher activities of malate dehydrogenase (9.962 (5.752-10.220) mU/mg protein) were detected in comparison to the CPA group (4.727 (4.562-5.299) mU/mg protein, p = 0.0385). Subchronic treadmill training in the rats with hyperhomocysteinemia triggers the colon tissue antioxidant response (by increasing the activities of superoxide dismutase and catalase) and elicits an increase in metabolic enzyme activities (lactate dehydrogenase and malate dehydrogenase). This study offers a comprehensive assessment of the effects of aerobic exercise on colonic tissues in a rat model of hyperhomocysteinemia, evaluating a range of biological indicators including antioxidant enzyme activity, metabolic enzyme activity, and morphometric parameters, which suggested that exercise may confer protective effects at both the physiological and morphological levels.

Longitudinal Analysis of 1α,25-dihidroxyvitamin D3 and Homocysteine Changes in Colorectal Cancer

Simple Summary

Vitamin D₃ and homocysteine level abnormalities are both strongly related to colorectal cancer (CRC) etiology. The aim of this retrospective study was to investigate the longitudinal change in these two parameters and the relationships between the two, in addition with other clinicopathological and laboratory parameters. A swoosh-shaped trend was observed for the change in serum homocysteine levels of all of the CRC patients. The circulating vitamin D₃ level was constant or increased in those patients without metastasis. After an initial increase, the disease-worsening effect of metastases cancelled out all of the positive effects of vitamin D₃ in metastatic patients, even despite its continuous supplementation. Right-sided tumors, male sex, and the pathological values of serum lipids, albumin, total protein, and inflammatory markers were associated with lower vitamin D₃ and higher homocysteine level. Based on our results, we recommend a modified vitamin D₃ supplementation regimen for metastatic CRC, which includes laboratory measurement-based titration.

Abstract

Background: 1α,25-dihydroxycholecalciferol (1,25(OH)₂D₃) and homocysteine are known to play a role in the pathophysiology of colorectal cancer (CRC). In health, the two changes are inversely proportional to each other, but little is known about their combined effect in CRC. Methods: The serum 1,25(OH)₂D₃ and the homocysteine levels of eighty-six CRC patients were measured, who were enrolled into four cohorts based on the presence of metastases (Adj vs. Met) and vitamin D₃ supplementation (ND vs. D). Results: 1,25(OH)₂D₃ was constant (Adj-ND), increased significantly (Adj-D, p = 0.0261), decreased (Met-ND), or returned close to the baseline after an initial increase (Met-D). The longitudinal increase in 1,25(OH)₂D₃ (HR: 0.9130, p = 0.0111) positively affected the overall survival in non-metastatic CRC, however, this effect was cancelled out in those with metastasis (p = 0.0107). The increase in homocysteine negatively affected both the overall (HR: 1.0940, p = 0.0067) and the progression-free survival (HR: 1.0845, p = 0.0073). Lower 1,25(OH)₂D₃ and/or higher homocysteine level was characteristic for patients with higher serum lipids, albumin, total protein, white blood cell and platelet count, male sex, and right-sided tumors. No statistically justifiable connection was found between the target variables. Conclusions: A measurement-based titration of vitamin D₃ supplementation and better management of comorbidities are recommended for CRC.

Epigenetic Aging: More Than Just a Clock When It Comes to Cancer

The incidence of cancer, adjusted for secular trends, is directly related to age, and advanced chronologic age is one of the most significant risk factors for cancer. Organismal aging is associated with changes at the molecular, cellular, and tissue levels and is affected by both genetic and environmental factors. The specific mechanisms through which these age-associated molecular changes contribute to the increased risk of aging-related disease, such as cancer, are incompletely understood. DNA methylation, a prominent epigenetic mark, also changes over a lifetime as part of an "epigenetic aging" process. Here, we give an update and review of epigenetic aging, in particular, the phenomena of epigenetic drift and epigenetic clock, with regard to its implication in cancer etiology. We discuss the discovery of the DNA methylation-based biomarkers for biological tissue age and the construction of various epigenetic age estimators for human clinical outcomes and health/life span. Recent studies in various types of cancer point to the significance of epigenetic aging in tumorigenesis and its potential use for cancer risk prediction. Future studies are needed to assess the potential clinical impact of strategies focused on lowering cancer risk by preventing premature aging or promoting healthy aging.

Colorectal polyp risk is linked to an elevated level of homocysteine

Several studies have reported an association between levels of folate, homocysteine, and vitamin B₁₂ and the risk of colorectal polyps. Here, our aim is to examine the possible effect of folate, homocysteine, and vitamin B₁₂ levels on the risk of colorectal polyps by means of meta-analysis based quantitative synthesis. According to our inclusion/exclusion criteria, a total of 13 case–control studies were enrolled. The P-value of the association test, standard mean difference (SMD), and 95% confidence interval (CI) were calculated. Pooled analysis data showed a negative correlation between the risk of colorectal polyps and the levels of serum folate, red blood cell (RBC) folate, or vitamin B₁₂ (all P>0.05). Nevertheless, for homocysteine level, we also observed a statistically significant difference between cases and controls in the overall and subgroup analysis of hospital-based control (HB), population-based control (PB), Chinese, Caucasian, or Asian (all P<0.05, SMD > 0). We found that increased levels of homocysteine may be statistically and significantly related to the risk of colorectal polyps.

Influence of MTHFR gene variations on perceived stress modification: Preliminary results of NURSE study

Background: High level of perceived stress in nurses is due to a genetic predisposition and environmental stressors. The aim of NURSE (Nursing Unacquainted Related Stress Etiologies) study was to investigate the association of C677T MTHFR gene polymorphism and stress perception among nurses.

Methods: In this comprehensive study, 216 female nurses were recruited. Perceived stress was assessed using the Cohen Perceived Stress Scale (PSS). Genomic DNA was extracted from peripheral blood, and MTHFR genotype was detected by the polymerase chain reaction.

Results: MTHFR C677T genotype analysis revealed that half of the participants had normal C/C genotype, and the remaining half presented higher frequencies of C/T genotype (39.8%) compared to T/T genotype (10.2%). The mean±SD stress score in morning shift, night shift, and rotation was 15.39±4.75, 15.92±4.94, and 15.83±5.61, respectively (p= 0.7). Perceived stress score was more in highly educated group but it was not significant (p= 0.2). Distribution of different MTHFR genotypes in diverse groups revealed that in groups with more stress score, the frequency of heterozygote (C/T) and homozygote (T/T) genotypes increased. Data revealed that in low stress category, 87% of the participants had a normal genotype. However, in high stress category, 71.3% of the participants had a normal genotype.

Conclusion: MTHFR genotype, independent of folate availability and probable confounding parameters, might be a potential risk factor of perceived stress among nurses.

Hyperhomocysteinemia as a potential contributor of colorectal cancer development in inflammatory bowel diseases: A review

Homocysteine is an amino acid generated metabolically by the S-adenosylmethionine-dependent transmethylation pathway. In addition to being a well-known independent risk factor for coronary heart disease, is also a risk factor for cancer. Patients suffering from inflammatory bowel diseases (IBD) including ulcerative colitis and Crohn’s disease are at increased risk of developing colorectal cancer in comparison to healthy individuals. Furthermore, the risk of hyperhomocysteinaemia is significantly higher in IBD patients when compared with controls. In the present article, we review the mechanisms in which hyperhomocysteinemia may contribute to increased risk of colorectal cancer in IBD patients.

Cholesterol affects gene expression of the Jun family in colon carcinoma cells using different signaling pathways

Hyperlipidemia and hypercholesterolemia have been found to be important factors in cancer development and metastasis. However, the metabolic mechanism and downstream cellular processes following cholesterol stimulation are still unknown. Here we tested the effect of cholesterol on MC-38 colon cancer cells. Using Illumina gene array technology we found a number of genes that were differentially expressed following short term (20-40 min) and longer term (between 2 and 5h) cholesterol stimulation. Three genes were consistently increased at these time points; c-Jun, Jun-B and the chemokine CXCL-1. We have previously shown that cholesterol stimulation leads to PI3K/Akt phosphorylation, and now demonstrated that cholesterol inhibits ERK1/2 phosphorylation; both effects reversed when cholesterol is depleted from lipid rafts using methyl-β-cyclodextrin (MBCD). In addition, vanadate, an inhibitor of phosphatases, reversed the cholesterol inhibition of ERK1/2 phosphorylation. Specific inhibition of p-Akt by wortmannin did not affect cholesterol's stimulation of the expression of c-Jun and Jun-B, however the vanadate effect of increasing p-ERK1/2, inhibited c-Jun expression, specifically, and the MBCD effect of increasing p-ERK and inhibiting p-Akt reduced c-Jun expression. In contrast MBCD and vanadate both enhanced Jun-B gene expression in the presence of cholesterol and elevation of ERK phosphorylation. Thus there is apparently, a differential signaling pathway whereby cholesterol enhances gene expression of the Jun family members.

Vitamin B6 deficiency, genome instability and cancer

Vitamin B6 functions as a coenzyme in >140 enzymatic reactions involved in the metabolism of amino acids, carbohydrates, neurotransmitters, and lipids. It comprises a group of three related 3-hydroxy-2-methyl-pyrimidine derivatives: pyridoxine (PN), pyridoxal (PL), pyridoxamine (PM) and their phosphorylated derivatives [pyridoxal 5'-phosphate (PLP) and pyridoxamine 5'-phosphate (PMP)], In the folate metabolism pathway, PLP is a cofactor for the mitochondrial and cytoplasmic isozymes of serine hydroxymethyltransferase (SHMT2 and SHMT1), the P-protein of the glycine cleavage system, cystathionine β-synthase (CBS) and γ-cystathionase, and betaine hydroxymethyltransferase (BHMT), all of which contribute to homocysteine metabolism either through folate- mediated one-carbon metabolism or the transsulfuration pathway. Folate cofactors carry and chemically activate single carbons for the synthesis of purines, thymidylate and methionine. So the evidence indicates that vitamin B6 plays an important role in maintenance of the genome, epigenetic stability and homocysteine metabolism. This article focuses on studies of strand breaks, micronuclei, or chromosomal aberrations regarding protective effects of vitamin B6, and probes whether it is folate-mediated one-carbon metabolism or the transsulfuration pathway for vitamin B6 which plays critical roles in prevention of cancer and cardiovascular disease.