Body mass index, diet, and exercise: testing possible linkages to breast cancer risk via DNA methylation

DNA methylation profile of inflammatory breast cancer and its impact on prognosis and outcome

BACKGROUND

Inflammatory breast cancer (IBC) is a rare disease characterized by rapid progression, early metastasis, and a high mortality rate.

METHODS

Genome-wide DNA methylation analysis (EPIC BeadChip platform, Illumina) and somatic gene variants (105 cancer-related genes) were performed in 24 IBCs selected from a cohort of 140 cases.

RESULTS

We identified 46,908 DMPs (differentially methylated positions) (66% hypomethylated); CpG islands were predominantly hypermethylated (39.9%). Unsupervised clustering analysis revealed three clusters of DMPs characterized by an enrichment of specific gene mutations and hormone receptor status. The comparison among DNA methylation findings and external datasets (TCGA-BRCA stages III-IV) resulted in 385 shared DMPs mapped in 333 genes (264 hypermethylated). 151 DMPs were associated with 110 genes previously detected as differentially expressed in IBC (GSE45581), and 68 DMPs were negatively correlated with gene expression. We also identified 4369 DMRs (differentially methylated regions) mapped on known genes (2392 hypomethylated). BCAT1, CXCL12, and TBX15 loci were selected and evaluated by bisulfite pyrosequencing in 31 IBC samples. BCAT1 and TBX15 had higher methylation levels in triple-negative compared to non-triple-negative, while CXCL12 had lower methylation levels in triple-negative than non-triple-negative IBC cases. TBX15 methylation level was associated with obesity.

CONCLUSIONS

Our findings revealed a heterogeneous DNA methylation profile with potentially functional DMPs and DMRs. The DNA methylation data provided valuable insights for prognostic stratification and therapy selection to improve patient outcomes.

Exercise-induced redox modulation as a mediator of DNA methylation in health maintenance and disease prevention

The evidence for physical activity (PA) as a major public health preventive approach and a potent medical therapy has increased exponentially in the last decades. The biomolecular mechanisms supporting the associations between PA and/or structured exercise training with health maintenance and disease prevention are not completely characterized. However, increasing evidence pointed out the role of epigenetic modifications in exercise adaptation and health-enhancing PA throughout life, DNA methylation being the most intensely studied epigenetic modification induced by acute and chronic exercise. The current data on the modulation of DNA methylation determined by physically active behavior or exercise interventions points out genes related to energy regulation, mitochondrial function, and biosynthesis, as well as muscle regeneration, calcium signaling pathways, and brain plasticity, all consistent with the known exercise-induced redox signaling and/or reactive oxygen species (ROS) unbalance. Thus, the main focus of this review is to discuss the role of ROS and redox-signaling on DNA methylation profile and its impact on exercise-induced health benefits in humans.

From multi-omics approaches to personalized medicine in myocardial infarction

Myocardial infarction (MI) is a prevalent cardiovascular disease characterized by myocardial necrosis resulting from coronary artery ischemia and hypoxia, which can lead to severe complications such as arrhythmia, cardiac rupture, heart failure, and sudden death. Despite being a research hotspot, the etiological mechanism of MI remains unclear. The emergence and widespread use of omics technologies, including genomics, transcriptomics, proteomics, metabolomics, and other omics, have provided new opportunities for exploring the molecular mechanism of MI and identifying a large number of disease biomarkers. However, a single-omics approach has limitations in understanding the complex biological pathways of diseases. The multi-omics approach can reveal the interaction network among molecules at various levels and overcome the limitations of the single-omics approaches. This review focuses on the omics studies of MI, including genomics, epigenomics, transcriptomics, proteomics, metabolomics, and other omics. The exploration extended into the domain of multi-omics integrative analysis, accompanied by a compilation of diverse online resources, databases, and tools conducive to these investigations. Additionally, we discussed the role and prospects of multi-omics approaches in personalized medicine, highlighting the potential for improving diagnosis, treatment, and prognosis of MI.

The Effects of Exercise Duration and Intensity on Breast Cancer-Related DNA Methylation: A Randomized Controlled Trial

Emerging research suggests that one mechanism through which physical activity may decrease cancer risk is through its influence on the methylation of genes associated with cancer. The purpose of the current study was to prospectively test, using a rigorous experimental design, whether aerobic exercise affects DNA methylation in genes associated with breast cancer, as well as whether quantity of exercise completed affects change in DNA methylation in a dose-response manner. 276 women (M age = 37.25, SD = 4.64) were recruited from the Denver metro area for a randomized controlled trial in which participants were assigned to a supervised aerobic exercise program varying in a fully crossed design by intensity (55-65% versus 75-85% of VO2max) and duration (40 versus 20 min per session). DNA methylation was assessed via blood samples provided at baseline, after completing a 16-week supervised exercise intervention, and six months after the intervention. 137 participants completed the intervention, and 81 had viable pre-post methylation data. Contrary to our hypotheses, total exercise volume completed in kcal/kg/week was not associated with methylation from baseline to post-intervention for any of the genes of interest. An increase in VO2max over the course of the intervention, however, was associated with decreased post-intervention methylation of BRCA1, p = 0.01. Higher levels of self-reported exercise during the follow-up period were associated with lower levels of GALNT9 methylation at the six-month follow-up. This study provides hypothesis-generating evidence that increased exercise behavior and or increased fitness might affect methylation of some genes associated with breast cancer to reduce risk.

Pre-diagnostic DNA methylation patterns differ according to mammographic breast density amongst women who subsequently develop breast cancer: a case-only study in the EPIC-Florence cohort

PURPOSE

Mammographic breast density (MBD) is a marker of increased breast cancer (BC) risk, yet much remains to be clarified about the underlying mechanisms. We investigated whether DNA methylation patterns differ between high- vs. low-MBD women who developed BC during an 8.9-year median follow-up in the Florence section of the European Prospective Investigation into Cancer and Nutrition.

METHODS

We analysed 96 pairs of women with BC arising on high- vs. low-MBD breasts (BI-RADS category III-IV vs. I). DNA methylation was determined on pre-diagnostic blood samples using the Illumina Infinium MethylationEPIC BeadChip assay. The statistical analysis was conducted by performing an epigenome-wide association study (EWAS), by searching differentially methylated regions (DMRs) in gene promoters (followed by functional enrichment and gene annotation analysis); and through a "candidate pathways" approach focusing on pre-defined inflammation-related pathways.

RESULTS

In EWAS, no single CpG site was differentially methylated between high- and low-MBD women after correction for multiple testing. A total of 140 DMRs were identified, of which 131 were hyper- and 9 hypo-methylated amongst high-MBD women. These DMRs encompassed an annotation cluster of 35 genes coding for proteins implicated in transcription regulation and DNA binding. The "apoptosis signalling" was the only inflammation-related candidate pathway differentially methylated between high- and low-MBD women.

CONCLUSION

Pre-diagnostic methylation patterns differ between high- vs. low-MBD women who subsequently develop BC, particularly, in genes involved in the regulation of DNA transcription and cell apoptosis. Our study provides novel clues about the mechanisms linking MBD and BC.

Behavioral Risk Factors: A Guide for Oncology Nurses Counseling Patients

BACKGROUND

Although many genetic and environmental causes of cancer are uncontrollable, individuals can choose behaviors that significantly increase or reduce their risk for cancer.

OBJECTIVES

This article discusses known cancer-protective behaviors, including exercising regularly, maintaining a healthy weight, vaccinating against cancer-associated viruses, and minimizing exposure to tobacco products, alcohol, processed meats, and ultraviolet light.

METHODS

The author performed a review of guidelines and techniques for counseling patients about risky behaviors, with an emphasis on patients with cancer.

FINDINGS

Much remains to be learned about the most effective clinical interventions for encouraging patients to adopt healthy behaviors, but oncology nurses should become familiar with the fundamental principles of counseling patients about health-promoting behaviors.

Identification of Modulated MicroRNAs Associated with Breast Cancer, Diet, and Physical Activity

Simple Summary

Healthy diet and physical activity are able to induce beneficial molecular modifications that have been associated with a lower risk of breast cancer (BC) incidence and a better prognosis for BC patients. Although the beneficial effects of healthy lifestyle have been described, the beneficial epigenetic modifications induced by dietary and exercise intervention in BC patients have not been elucidated yet. On these bases, the aim of the present study was to computationally identify microRNAs (miRNAs) strictly associated with BC progression and with dietary and exercise interventions. Through several computational approaches, a set of miRNAs modulated by diet and exercise and useful as diagnostic and prognostic biomarkers for BC was identified. The results obtained represent the starting point for further validation analyses performed on BC patients undergoing lifestyle interventions to propose the miRNAs here identified as novel biomarkers for BC management.

Abstract

Background: Several studies have shown that healthy lifestyles prevent the risk of breast cancer (BC) and are associated with better prognosis. It was hypothesized that lifestyle strategies induce microRNA (miRNA) modulation that, in turn, may lead to important epigenetic modifications. The identification of miRNAs associated with BC, diet, and physical activity may give further insights into the role played by lifestyle interventions and their efficacy for BC patients. To predict which miRNAs may be modulated by diet and physical activity in BC patients, the analyses of different miRNA expression datasets were performed. Methods: The GEO DataSets database was used to select miRNA expression datasets related to BC patients, dietary interventions, and physical exercise. Further bioinformatic approaches were used to establish the value of selected miRNAs in BC development and prognosis. Results: The analysis of datasets allowed the selection of modulated miRNAs associated with BC development, diet, and physical exercise. Seven miRNAs were also associated with the overall survival of BC patients. Conclusions: The identified miRNAs may play a role in the development of BC and may have a prognostic value in patients treated with integrative interventions including diet and physical activity. Validation of such modulated miRNAs on BC patients undergoing lifestyle strategies will be mandatory.

Epigenetics in Inflammatory Breast Cancer: Biological Features and Therapeutic Perspectives

Evidence has emerged implicating epigenetic alterations in inflammatory breast cancer (IBC) origin and progression. IBC is a rare and rapidly progressing disease, considered the most aggressive type of breast cancer (BC). At clinical presentation, IBC is characterized by diffuse erythema, skin ridging, dermal lymphatic invasion, and peau d'orange aspect. The widespread distribution of the tumor as emboli throughout the breast and intra- and intertumor heterogeneity is associated with its poor prognosis. In this review, we highlighted studies documenting the essential roles of epigenetic mechanisms in remodeling chromatin and modulating gene expression during mammary gland differentiation and the development of IBC. Compiling evidence has emerged implicating epigenetic changes as a common denominator linking the main risk factors (socioeconomic status, environmental exposure to endocrine disruptors, racial disparities, and obesity) with IBC development. DNA methylation changes and their impact on the diagnosis, prognosis, and treatment of IBC are also described. Recent studies are focusing on the use of histone deacetylase inhibitors as promising epigenetic drugs for treating IBC. All efforts must be undertaken to unravel the epigenetic marks that drive this disease and how this knowledge could impact strategies to reduce the risk of IBC development and progression.

DNA methylation, colon cancer and Mediterranean diet: results from the EPIC-Italy cohort

The biological mechanisms through which adherence to Mediterranean Diet (MD) protects against colon cancer (CC) are poorly understood. Evidence suggests that chronic inflammation may be implicated in the pathway. Both diet and CC are related to epigenetic regulation. We performed a nested case-control study on 161 pairs from the Italian component of the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, in which we looked for the methylation signals in DNA extracted from leucocytes associated with both CC and MD in 995 CpGs located in 48 inflammation genes. The DNA methylation signals detected in this analysis were validated in a subgroup of 47 case-control pairs and further replicated (where validated) in 95 new pairs by means of pyrosequencing. Among the CpG sites selected a-priori in inflammation-related genes, seven CpG sites were found to be associated with CC status and with MD, in line with its protective effect. Only two CpG sites (cg17968347-SERPINE1 and cg20674490-RUNX3) were validated using bisulphite pyrosequencing and, after replication, we found that DNA methylation of cg20674490-RUNX3 may be a potential molecular mediator explaining the protective effect of MD on CC onset. The use of a 'meet-in-the-middle' approach to identify the overlap between exposure and predictive markers of disease is innovative in studies on the relationship between diet and cancer, in which exposure assessment is difficult and the mechanisms through which the nutrients exert their protective effect is largely unknown.

Does Body Mass Index and Height Influence the Incident Risk of Ischemic Stroke in Newly Diagnosed Type 2 Diabetes Subjects?

OBJECTIVE

To estimate the incident risk of ischemic stroke (IS) in newly diagnosed type 2 diabetes (T2D) subjects according to different body mass index (BMI) and height categories.

METHODS

A total of 25,130 newly diagnosed T2D subjects were included in this study. All T2D subjects were enrolled consecutively from the Chronic Disease Surveillance System (CDSS) of Ningbo. Standardized incidence ratio (SIR) and its 95% confidence interval (95% CI) stratified by BMI categories and height quartiles were used to estimate the incident risk of IS in T2D subjects.

RESULTS

In total, 22,795 subjects completed the follow-up. Among them, 1268 newly diagnosed IS cases were identified, with 149,675 person-years. The SIRs of normal BMI (18.5-24.0 kg/m²), overweight (24.0-28.0 kg/m²), and obese (≥28.0 kg/m²) in overall subjects were 2.56 (95% CI 1.90-3.13), 2.13 (95% CI 1.90-3.13), and 1.87 (95% CI 1.29-2.43), respectively (P _trend < 0.01), comparing to the general population of Ningbo. For each 1 kg/m² increment in BMI, the SIR was 0.948 (95% CI 0.903-0.999). For height quartiles, the SIRs of male subjects in quartile 1 (<160 cm), quartile 2 (161-165 cm), quartile 3 (165-170 cm), and quartile 4 (≥171 cm) were 2.27 (95% CI 1.99-2.56), 2.01 (95% CI 1.67-2.45), 1.37 (95% CI 1.05-1.68), and 0.91 (95% CI 0.40-1.32), respectively (P _trend < 0.01). While for female subjects, the SIRs in quartile 1 (<155 cm), quartile 2 (156-160 cm), quartile 3 (161-165 cm), and quartile 4 (≥166 cm) were 3.57 (95% CI 3.11-3.49), 2.96 (95% CI 2.61-3.31), 1.94 (95% CI 1.51-2.36), and 1.71 (95% CI 0.95-2.47), respectively (P _trend < 0.01).

CONCLUSION

Compared to the general population of Ningbo, T2D subjects had a higher incident risk of IS. Furthermore, the IS incident risk was not only higher in newly diagnosed T2D subjects with normal BMI but also lower in taller newly diagnosed T2D subjects.