Circulating miRNAs as early indicators of diet and physical activity response in women with metastatic breast cancer

Advances in Diet and Physical Activity in Breast Cancer Prevention and Treatment

There is currently a growing interest in diets and physical activity patterns that may be beneficial in preventing and treating breast cancer (BC). Mounting evidence indicates that indeed, the so-called Mediterranean diet (MedDiet) and regular physical activity likely both help reduce the risk of developing BC. For those who have already received a BC diagnosis, these interventions may decrease the risk of tumor recurrence after treatment and improve quality of life. Studies also show the potential of other dietary interventions, including fasting or modified fasting, calorie restriction, ketogenic diets, and vegan or plant-based diets, to enhance the efficacy of BC therapies. In this review article, we discuss the biological rationale for utilizing these dietary interventions and physical activity in BC prevention and treatment. We highlight published and ongoing clinical studies that have applied these lifestyle interventions to BC patients. This review offers valuable insights into the potential application of these dietary interventions and physical activity as complimentary therapies in BC management.

The Effect of Physical Activity/Exercise on miRNA Expression and Function in Non-Communicable Diseases-A Systematic Review

Exercise may differently affect the expression of key molecular markers, including skeletal muscle and circulating miRNAs, involved in cellular and metabolic pathways' regulation in healthy individuals and in patients suffering from non-communicable diseases (NCDs). Epigenetic factors are emerging as potential therapeutic biomarkers in the prognosis and treatment of NCDs and important epigenetic factors, miRNAs, play a crucial role in cellular pathways. This systematic review aims to underline the potential link between changes in miRNA expression after different types of physical activity/exercise in some populations affected by NCDs. In June 2023, we systematically investigated the following databases: PubMed, MEDLINE, Scopus, and Web of Science, on the basis of our previously established research questions and following the PRISMA guidelines. The risk of bias and quality assessment were, respectively, covered by ROB2 and the Newcastle Ottawa scale. Of the 1047 records extracted from the initial search, only 29 studies were found to be eligible. In these studies, the authors discuss the association between exercise-modulated miRNAs and NCDs. The NCDs included in the review are cancer, cardiovascular diseases (CVDs), chronic obstructive pulmonary disease (COPD), and type 2 diabetes mellitus (T2DM). We evidenced that miR-146, miR-181, miR-133, miR-21, and miRNA-1 are the most reported miRNAs that are modulated by exercise. Their expression is associated with an improvement in health markers and they may be a potential target in terms of the development of future therapeutic tools.

Epigenetic Biomarkers of Metabolic Responses to Lifestyle Interventions

Studies have examined the possible utility of epigenetic phenomena (DNA methylation changes, covalent histone modifications, and miRNA expression patterns) in predicting individual responses to different lifestyle programs. Nonetheless, most available evidence is focused on identifying epigenetic marks eventually associated with body composition and adiposity outcomes, whereas their roles in metabolic endings remain less explored. This document comprehensively reviewed the evidence regarding the use of epigenetic signatures as putative biomarkers of metabolic outcomes (glycemic, lipid, blood pressure, and inflammatory/oxidative stress features) in response to different lifestyle interventions in humans. Although more investigation is still necessary in order to translate this knowledge in clinical practice, these scientific insights are contributing to the design of advanced strategies for the precise management of cardiometabolic risk, gaining understanding on metabolic heterogeneity, allowing for the prediction of metabolic outcomes, and facilitating the design of epigenome-based nutritional strategies for a more customized approach for metabolic alterations treatment under the scope of precision nutrition.

Analysis of circulating extracellular vesicle derived microRNAs in breast cancer patients with obesity: a potential role for Let-7a

BACKGROUND

The incidence of obesity, a known risk factor for several metabolic and chronic diseases, including numerous malignancies, has risen sharply in the world. Various clinical studies demonstrate that excessive Body Mass Index (BMI) may worsen the incidence, prognosis, and mortality rates of breast cancer. Thus, understanding the link tying up obesity and breast cancer onset and progression is critically important, as it can impact patients' survival and quality of life. Recently, circulating extracellular vesicle (EV) derived miRNAs have attracted much attention for their diagnostic, prognostic and therapeutic potential in oncology research. Although the potential role of EV-derived miRNAs in the early detection of breast cancer has been repeatedly mentioned, screening of miRNAs packaged within serum EVs has not yet been reported in patients with obesity.

METHODS

Circulating EVs were isolated from normal weight (NW), and overweight/obese (OW/Ob) breast cancer patients and characterized by Transmission Electron Microscopy (TEM), Nanoparticle Tracking Analysis (NTA), and protein marker expression. Evaluation of EV-associated miRNAs was conducted in a screening (RNA-seq) and a validation (qRT-PCR) cohort. Bioinformatic analysis was performed to uncover significantly enriched biological processes, molecular functions and pathways. ROC and Kaplain-Meier survival analyses were used for clinical significance.

RESULTS

Comparison of serum EV-derived miRNAs from NW and OW/Ob patients detected seven differentially expressed miRNAs (let-7a-5p, miR-122-5p, miR-30d-5p, miR-126-3p, miR-27b-3p, miR-4772-3p, and miR-10a-5p) in the screening cohort. GO analysis revealed the enrichment of protein phosphorylation, intracellular signal transduction, signal transduction, and vesicle-mediated transport among the top biological processes. In addition, the target genes were significantly enriched in pathways related to PI3K/Akt, growth hormones, and insulin signalings, which are all involved in obesity-related diseases and/or breast cancer progression. In the validation cohort, qRT-PCR confirmed a significant down-regulation of EV-derived let-7a in the serum of OW/Ob breast cancer patients compared to NW patients. Let-7a levels also exhibited a negative correlation with BMI values. Importantly, decreased let-7a miRNA expression was associated with higher tumor grade and poor survival in patients with breast cancer.

CONCLUSION

These results suggest that serum-EV derived miRNAs may reflect a differential profile in relation to a patient's BMI, which, once validated in larger cohorts of patients, could provide insights into novel specific biomarkers and innovative targets to prevent the progression of obesity-mediated breast cancer.

Exercise training attenuates angiotensin II-induced cardiac fibrosis by reducing POU2F1 expression

PURPOSE

Exercise training protects against heart failure. However, the mechanism underlying the protective effect of exercise training on angiotensin II (Ang II)-induced cardiac fibrosis remains unclear.

METHODS

An exercise model involving C57BL/6N mice and 6 weeks of treadmill training was used. Ang II (1.44 mg/kg/day) was administered to induce cardiac fibrosis. RNA sequencing and bioinformatic analysis were used to identify the key factors mediating the effects of exercise training on cardiac fibrosis. Primary adult mouse cardiac fibroblasts (CFs) were used in vitro. Adeno-associated virus serotype 9 was used to overexpress POU domain, class 2, transcription factor 1 (POU2F1) in vivo.

RESULTS

Exercise training attenuated Ang II-induced cardiac fibrosis and reversed 39 gene expression changes. The transcription factor regulating the largest number of these genes was POU2F1. Compared to controls, POU2F1 was shown to be significantly upregulated by Ang II, which is itself reduced by exercise training. In vivo, POU2F1 overexpression nullified the benefits of exercise training on cardiac fibrosis. In CFs, POU2F1 promoted cardiac fibrosis. CCAAT enhancer-binding protein β (C/EBPβ) was predicted to be the transcription factor of POU2F1 and verified using a dual-luciferase reporter assay. In vivo, exercise training activated AMP-activated protein kinase (AMPK) and alleviated the increase in C/EBPβ induced by Ang II. In CFs, AMPK agonist inhibited the increase in C/EBPβ and POU2F1 induced by Ang II, whereas AMPK inhibitor reversed this effect.

CONCLUSION

Exercise training attenuates Ang II-induced cardiac fibrosis by reducing POU2F1. Exercise training inhibits POU2F1 by activating AMPK, which is followed by the downregulation of C/EBPβ, the transcription factor of POU2F1.

Regulation of the Effect of Physical Activity Through MicroRNAs in Breast Cancer

Physical activity and exercise can induce beneficial molecular and biological regulations that have been associated with an incidence of various diseases, including breast cancer. Recent studies demonstrated that the potential links between physical activity-induced circulating microRNAs (miRNAs) and cancer risk and progression. Here, we investigated whether altered miRNAs by exercise could influence breast cancer progression. After primary searching in PubMed and reviewing the full-text papers, candidate miRNAs altered by exercise in breast cancer were identified. Analysis of expression profiles and clinical outcomes of altered miRNAs using The Cancer Genome Atlas datasets showed altered miRNAs expressions were significantly associated with the patient's prognosis, whereas prognostic values of each miRNA varied in different stages and subtypes. In addition, altered miRNAs profiles regulated various target genes and key signaling pathways in tumorigenesis, including pathways in cancer and the PI3K-Akt signaling pathway; however, miRNAs regulated the expression of target genes differently according to tumor stages and subtypes. These results indicate that circulating miRNAs are promising noninvasive stable biomarkers for early detection, diagnosis, prognosis, and monitoring the response to clinical therapies of breast cancer. Moreover, stages and subtype-stratified approaches for breast cancer progression would be needed to evaluate the prognostic value of miRNAs for biomarkers and therapeutic targets.

The Effect of miR-520b on Macrophage Polarization and T Cell Immunity by Targeting PTEN in Breast Cancer

Background

Breast cancer is the most common cancer in women. miR-520b had binding sites with PTEN through the bioinformatics prediction. But few studies have been conducted on miR-520b and PTEN in breast cancer. We aimed to explore the effect of miR-520b and PTEN on breast cancer and the mechanisms involved.

Methods

Clinical samples of breast cancer were collected. Bioinformatics analysis was performed to screen the differentially expressed miRNAs. CD4 T cells and CD8 T cells were cocultured with MCF-7 cells in the Transwell system. Moreover, MCF-7 cells and M0 macrophage cocultured cell lines were constructed. qRT-PCR, IF, western blot, flow cytometry, and ELISA were performed to detect related factors expression. Starbase and dual-luciferase reporter assay verified the binding of miR-520b to PTEN. The tumor formation model was established to study miR-520b and PTEN effects in vivo.

Results

The differentially expressed miR-520b was screened via miRNAs sequencing and cell verification. miR-520b expression was high, PTEN was low in tumor tissues, T cells and NK cells were inhibited, and macrophages were transformed into M2 type, promoting immune escape. In addition, miR-520b bound to PTEN. Then, splenic CD4 T cells and CD8 T cells were successfully sorted. During CD4 T cell differentiation to Th1 and Treg, Th1 was inhibited, and Treg was activated. We found the polarization of macrophages was related to breast cancer. The proportion of CD206 cells increased and CD68 cells decreased in the miR-520b mimics group compared with the mimic NC group. Compared with the inhibitor NC group, the proportion of CD206 cells decreased, and CD68 cells increased in the miR-520b inhibitor group. In vivo experiments showed that miR-520b inhibitor inhibited tumor growth and promoted PTEN expression. The proportion of CD3, CD4, CD8, NK1.1, CD4+IFNγ, and CD68 cells increased, while FOXP3 and CD206 cells decreased in the miR-520b inhibitor group compared with the inhibitor NC group. However, the proportion of CD3, CD4, CD8, NK1.1, CD4+IFNγ, and CD68 cells decreased, while FOXP3 and CD206 cells increased after the addition of siPTEN.

Conclusions

miR-520b inhibited PTEN and aggravated breast tumors. miR-520b inhibitor enhanced CD4 and CD8 cell populations in the tumor immune microenvironment and inhibited tumor growth.