The Complex Biology of the Obesity-Induced, Metastasis-Promoting Tumor Microenvironment in Breast Cancer

Beyond blood pressure, fluid and electrolyte homeostasis - Role of the renin angiotensin aldosterone system in the interplay between metabolic diseases and breast cancer

The classical renin angiotensin aldosterone system (RAAS), as well as the recently described counter-regulatory or non-canonical RAAS have been well characterized for their role in cardiovascular homeostasis. Moreover, extensive research has been conducted over the past decades on both paracrine and the endocrine roles of local RAAS in various metabolic regulations and in chronic diseases. Clinical evidence from patients on RAAS blockers as well as pre-clinical studies using rodent models of genetic manipulations of RAAS genes documented that this system may play important roles in the interplay between metabolic diseases and cancer, namely breast cancer. Some of these studies suggest potential therapeutic applications and repurposing of RAAS inhibitors for these diseases. In this review, we discuss the mechanisms by which RAAS is involved in the pathogenesis of metabolic diseases such as obesity and type-2 diabetes as well as the role of this system in the initiation, expansion and/or progression of breast cancer, especially in the context of metabolic diseases.

MIF as a potential diagnostic and prognostic biomarker for triple-negative breast cancer that correlates with the polarization of M2 macrophages

Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine that plays a crucial role in antitumor immunity. However, the role of MIF in influencing the tumor microenvironment (TME) and prognosis of triple-negative breast cancer (TNBC) remains to be elucidated. Using R, we analyzed single-cell RNA sequencing (scRNA-seq) data of 41 567 cells from 10 TNBC tumor samples and spatial transcriptomic data from two patients. Relationships between MIF expression and immune cell infiltration, clinicopathological stage, and survival prognosis were determined using samples from The Cancer Genome Atlas (TCGA) and validated in a clinical cohort using immunohistochemistry. Analysis of scRNA-seq data revealed that MIF secreted by epithelial cells in TNBC patients could regulate the polarization of macrophages into the M2 phenotype, which plays a key role in modulating the TME. Spatial transcriptomic data also showed that epithelial cells (tumor cells) and MIF were proximally located. Analysis of TCGA samples confirmed that tumor tissues of patients with high MIF expression were enriched with M2 macrophages and showed a higher T stage. High MIF expression was significantly associated with poor patient prognosis. Immunohistochemical staining showed high MIF expression was associated with younger patients and worse clinicopathological staging. MIF secreted by epithelial cells may represent a potential biomarker for the diagnosis and prognosis of TNBC and may promote TNBC invasion by remodeling the tumor immune microenvironment.

A contemporary review of breast cancer risk factors and the role of artificial intelligence

Background

Breast cancer continues to be a significant global health issue, necessitating advancements in prevention and early detection strategies. This review aims to assess and synthesize research conducted from 2020 to the present, focusing on breast cancer risk factors, including genetic, lifestyle, and environmental aspects, as well as the innovative role of artificial intelligence (AI) in prediction and diagnostics.

Methods

A comprehensive literature search, covering studies from 2020 to the present, was conducted to evaluate the diversity of breast cancer risk factors and the latest advances in Artificial Intelligence (AI) in this field. The review prioritized high-quality peer-reviewed research articles and meta-analyses.

Results

Our analysis reveals a complex interplay of genetic, lifestyle, and environmental risk factors for breast cancer, with significant variability across different populations. Furthermore, AI has emerged as a promising tool in enhancing the accuracy of breast cancer risk prediction and the personalization of prevention strategies.

Conclusion

The review highlights the necessity for personalized breast cancer prevention and detection approaches that account for individual risk factor profiles. It underscores the potential of AI to revolutionize these strategies, offering clear recommendations for future research directions and clinical practice improvements.

White adipocyte dysfunction and obesity-associated pathologies in humans

The prevalence of obesity and associated chronic diseases continues to increase worldwide, negatively impacting on societies and economies. Whereas the association between excess body weight and increased risk for developing a multitude of diseases is well established, the initiating mechanisms by which weight gain impairs our metabolic health remain surprisingly contested. In order to better address the myriad of disease states associated with obesity, it is essential to understand adipose tissue dysfunction and develop strategies for reinforcing adipocyte health. In this Review we outline the diverse physiological functions and pathological roles of human white adipocytes, examining our current knowledge of why white adipocytes are vital for systemic metabolic control, yet poorly adapted to our current obesogenic environment.

miR-203a-A multifaceted regulator modulating cancer hallmarks and therapy response

MicroRNAs (miRNAs) are a class of noncoding RNAs of about 19-25 nucleotides, which serve as critical modulators of various cellular and biological processes by target gene regulation. Dysregulated expression of miRNAs modulates the pathophysiology of various human diseases, including cancer. Among miRNAs, miR-203a is one of the most extensively researched dysregulated miRNAs in different cancers. Our review investigated the roles of miR-203a in the hallmarks of cancer modulating different pathways through target gene regulations, chemoresistance, its crosstalk with other ncRNAs or genes in terms of ceRNAs impacting oncogenesis, and its potential applications in the diagnosis, prognosis, and chemotherapeutic responses in different cancer types. miR-203a impacts cancer cell behavior by regulating these exclusive hallmarks- sustaining proliferation, cell growth, invasion and metastasis, cell death, and angiogenesis. Besides, miR-203a is found in human circulating biofluids like plasma or serum of colorectal cancer, cervical cancer, and hepatocellular carcinoma, hinting at its potential as a biomarker. Further, miR-203a is involved in enhancing the chemosensitivity of cisplatin, docetaxel, paclitaxel, doxorubicin, and 5-fluorouracil in a variety of malignancies through their cognate target genes. These results suggest that miR-203a is a crucial multifaceted miRNA that controls cancer cell proliferation, metastasis, and chemotherapy response, shedding new light on its possible application.

The Effect of Adipocyte-Secreted Factors in Activating Focal Adhesion Kinase-Mediated Cell Signaling Pathway towards Metastasis in Breast Cancer Cells

Obesity-associated perturbations in the normal secretion of adipocytokines from white adipocytes can drive the metastatic progression of cancer. However, the association between obesity-induced changes in secretory factors of white adipocytes and subsequent transactivation of the downstream effector proteins impacting metastasis in breast cancer cells remains unclear. Focal adhesion kinase, a cytoplasmic signal transducer, regulates the biological phenomenon of metastasis by activating downstream targets such as beta-catenin and MMP9. Thus, the possible role of phosphorylated FAK in potentiating cancer cell migration was investigated. To elucidate this potential relationship, MCF7 (ER+), MDA-MB-231 (Triple Negative) breast cancer cells, and MCF-10A non-tumorigenic breast cells were exposed to in vitro murine adipocyte-conditioned medium derived from 3T3-L1 MBX cells differentiated to obesity with fatty acid supplementation. Our results show that the conditioned medium derived from these obese adipocytes enhanced motility and invasiveness of breast cancer cells. Importantly, no such changes were observed in the non-tumorigenic breast cells. Our results also show that increased FAK autophosphorylation was followed by increased expression of beta-catenin and MMP9 in the breast cancer cells when exposed to obese adipocyte-conditioned medium, but not in the MCF10A cells. These results indicate that adipocyte-derived secretory factors induced FAK activation through phosphorylation. This in turn increased breast cancer cell migration and invasion by activating its downstream effector proteins beta-catenin and MMP9.

Characterizing 3T3-L1 MBX Adipocyte Cell Differentiation Maintained with Fatty Acids as an In Vitro Model to Study the Effects of Obesity

The increasing prevalence of obesity has prompted intensive research into understanding its role in pathogenesis and designing appropriate treatments. To determine the signals generated from the interaction of fat cells with a target organ, a reliable white adipocyte model in vitro is needed. Differentiated fibroblasts are the most extensively studied using in vitro cell models of white adipocytes. However, it can be argued that differentiated fibroblasts minimally recapitulate the consequences of obesity. Here, we describe 3T3-L1 MBX cells as a culture model for studying obese adipocytes and their effects. Differentiation of 3T3-L1 MBX cells was at first optimized and then maintained in the presence of fatty acids cocktail combination to induce the obese condition. Lipid accumulation and adipokine secretion profiles were analyzed. Results showed that fatty acid-maintained, differentiated 3T3-L1 MBX cells had significantly greater accumulation of lipids and significant changes in the adipokine secretions in comparison to differentiated 3T3-L1 MBX cells maintained in medium without fatty acids. To elucidate the molecular changes associated with adipogenesis and lipid accumulation profile of 3T3-L1 MBX cells, we have also explored the expression of some of the regulatory proteins related to the development and maintenance of adipocytes from the preadipocyte lineage.

Caveolin-1 genotypes as predictor for locoregional recurrence and contralateral disease in breast cancer

PURPOSE

Caveolin-1 (CAV1) has been implicated in breast cancer oncogenesis and metastasis and may be a potential prognosticator, especially for non-distant events. CAV1 functions as a master regulator of membrane transport and cell signaling. Several CAV1 SNPs have been linked to multiple cancers, but the prognostic impact of CAV1 SNPs in breast cancer remains unclear. Here, we investigated CAV1 polymorphisms in relation to clinical outcomes in breast cancer.

METHODS

A cohort of 1017 breast cancer patients (inclusion 2002-2012, Sweden) were genotyped using Oncoarray by Ilumina. Patients were followed for up to 15 years. Five out of six CAV1 SNPs (rs10256914, rs959173, rs3807989, rs3815412, and rs8713) passed quality control and were used for haplotype construction. CAV1 genotypes and haplotypes in relation to clinical outcomes were assessed with Cox regression and adjusted for potential confounders (age, tumor characteristics, and adjuvant treatments).

RESULTS

Only one SNP was associated with lymph node status, no other SNPs or haplotypes were associated with tumor characteristics. The CAV1 rs3815412 CC genotype (5.8% of patients) was associated with increased risk of contralateral breast cancer, adjusted hazard ratio (HR_adj) 4.26 (95% CI 1.86-9.73). Moreover, the TTACA haplotype (13% of patients) conferred an increased risk for locoregional recurrence HR_adj 2.24 (95% CI 1.24-4.04). No other genotypes or haplotypes were associated with clinical outcome.

CONCLUSION

CAV1 polymorphisms were associated with increased risk for locoregional recurrence and contralateral breast cancer. These findings may identify patients that could derive benefit from more tailored treatment to prevent non-distant events, if confirmed.

Cancer-Associated Adipocytes and Breast Cancer: Intertwining in the Tumor Microenvironment and Challenges for Cancer Therapy

Adipocytes are the main components in breast tissue, and cancer-associated adipocytes (CAAs) are one of the most important components in the tumor microenvironment of breast cancer (BC). Bidirectional regulation was found between CAAs and BC cells. BC facilitates the dedifferentiation of adjacent adipocytes to form CAAs with morphological and biological changes. CAAs increase the secretion of multiple cytokines and adipokines to promote the tumorigenesis, progression, and metastasis of BC by remodeling the extracellular matrix, changing aromatase expression, and metabolic reprogramming, and shaping the tumor immune microenvironment. CAAs are also associated with the therapeutic response of BC and provide potential targets in BC therapy. The present review provides a comprehensive description of the crosstalk between CAAs and BC and discusses the potential strategies to target CAAs to overcome BC treatment resistance.

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

Simple Summary

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

Abstract

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

Melatonin as an oncostatic agent: Review of the modulation of tumor microenvironment and overcoming multidrug resistance

Multi drug resistance (MDR) generally limits the efficacy of chemotherapy in cancer patients and can be categorized into primary or acquired resistance. Melatonin (MLT), a lipophilic hormone released from pineal gland, is a molecule with oncostatic effects. Here, we will briefly review the contribution of different microenvironmental components including fibroblasts, immune and inflammatory cells, stem cells and vascular endothelial cells in tumor initiation, progression and development. Then, the mechanisms by which MLT can potentially affect these elements and regulate drug resistance will be presented. Finally, we will explain how different studies have used novel strategies incorporating MLT to suppress cancer resistance against therapeutics.