ROLE OF MicroRNAs 223, 155, AND 17~92 IN THE REGULATION OF MYELOID-DERIVED SUPPRESSOR CELLS (MDSCS) IN THE PATHOGENESIS OF OBESITY-ASSOCIATED BREAST CANCER

Abstract

Relevance: Breast cancer (BC) is a pressing global health dilemma due to its high prevalence worldwide. According to the World Health Organization (WHO), more than 2.3 million cases of BC occur each year, and BC is the first leading cause of female cancer deaths globally. Evidence indicates that obesity increases the risk of developing BC, and myeloid-derived suppressor cells (MDSCs) play a significant role in the pathogenesis of both BC and obesity. The primary function of MDSCs is tissue repair and wound healing, which helps prevent uncontrolled inflammation and maintain homeostasis as part of the immune response. However, MDSCs can be reprogrammed by pathological processes due to long-term tissue damage caused by chronic inflammation and cancer, leading to their prolonged expansion and enhanced immunosuppressive activity. The pathological process of obesity-associated and MDSC-associated BC progression remains poorly understood at the molecular level. There is considerable interest in studying microRNAs due to their regulatory roles in various biological processes in different cell types. Recent studies have begun to unravel the crosstalk between microRNAs and MDSCs in cancer. 
The study aimed to provide summarized data to reveal the mechanisms by which microRNAs influence the activity of MDSC and the course of obesity-associated BC.
Methods: We conducted a comprehensive literature search on the web and in Medline (PubMed) и Google Scholar databases until June 7, 2024, in the areas «breast cancer» and/or «obesity» and/or «MDSC» and/or «microRNA.» Based on the literature analysis, microRNA-223, -155, and -1792 were selected as the most significant objects.
Results: This review presents data on the expression dynamics of major signal microRNAs (microRNA-223, -155, and -17~92), focusing on their roles in the pathogenesis of BC, obesity, and MDSC regulation; we also summarized and discussed the regulation of MDSCs in the obesity-associated BC by microRNA-223, -155, and -17~92.
Conclusion: Based on the literature data analysis, miR-223, -155, and -17~92 may be promising diagnostic and therapeutic cancer biomarkers, including BC, associated with pathological metabolic disorders and impaired functional activity of MDSC.