Adipose tissue macrophages: implications for obesity-associated cancer

Abstract

Obesity is one of the most serious global health problems, with an incidence that increases yearly and coincides with the development of cancer. Adipose tissue macrophages (ATMs) are particularly important in this context and contribute to linking obesity-related inflammation and tumor progression. However, the functions of ATMs on the progression of obesity-associated cancer remain unclear. In this review, we describe the origins, phenotypes, and functions of ATMs. Subsequently, we summarize the potential mechanisms on the reprogramming of ATMs in the obesity-associated microenvironment, including the direct exchange of dysfunctional metabolites, inordinate cytokines and other signaling mediators, transfer of extracellular vesicle cargo, and variations in the gut microbiota and its metabolites. A better understanding of the properties and functions of ATMs under conditions of obesity will lead to the development of new therapeutic interventions for obesity-related cancer.

Red and melanized focal changes in white skeletal muscle in Atlantic salmon (Salmo salar): Comparative analysis of farmed, wild and hybrid fish reared under identical conditions

“…The observed focal changes at both sampling points in sea water (day 369 and 537) aligned with the histological descriptions of RFC and MFC provided by Bjørgen et al, 2019 andBjørgen et al, 2020. RFC were present in all experimental groups and exhibited simi- tissue of obese humans due to elevated levels of pro-inflammatory mediators (Li et al, 2023;Page et al, 2011). Inflammation of adipose tissue can potentially be induced by hypoxia resulting from adipocytes hypertrophy (Trayhurn et al, 2008).…”

“…Additionally, an inflammatory state within the adipose tissue induced by adipocytes themselves could lead to recruitment of inflammatory cells. Reports have indicated an increase in recruited macrophages within adipose tissue of obese humans due to elevated levels of pro‐inflammatory mediators (Li et al, 2023; Page et al, 2011). Inflammation of adipose tissue can potentially be induced by hypoxia resulting from adipocytes hypertrophy (Trayhurn et al, 2008).…”

Immunology of chronic low-grade inflammation: relationship with metabolic function

“…The authors utilized a human co-culture system to study the paracrine interactions and demonstrated that pro-inflammatory macrophage-conditioned media intensified the crosstalk between breast cancer cells and adipocytes, causing the breast cancer cells to become more aggressive (Vallega et al 2022). The exact molecular mechanisms underlying this interaction are still unclear but are likely multifactorial and related to the exchange of dysfunctional metabolites, disproportionate cytokine and growth factor production, and transfer of extracellular vesicle cargo (Vallega et al 2022, Li et al 2023. A better understanding of the properties and functions of dysregulated ATMs in obesity-diabetes is required before specific enzymes and/or pathways can be targeted for therapeutic intervention.…”

“…1 and 2). This low-grade chronic metabolic inflammation should not be neglected as it is significantly associated with all-cause mortality in the general population (Fest et al 2019), negatively impacts insulin sensitivity (Blaszczak et al 2020), and increases the risk for cancer development (Li et al 2023).…”

The Role of RNA Epitranscriptomics and the RNA Fat Mass and Obesity-Associated Demethylase in Triple Negative Breast Cancer

“…Like all complex organs, there are intracellular communications between the cells in both normal tissues and in the cancers that derive from these organs. For example, adipose tissue macrophages may be influenced by the abnormal microenvironment in obesity and contribute to aggressive behavior of tumors, metastasis, and an im- [30]. Similarly, cross talk from the adipocytes in obesity also seems to promote fibrosis, aggressiveness and metastasis in breast cancer and other obesity-associated cancers [31].…”