Functional Analysis of Extracellular Vesicle-Associated miRNAs from Mammary Tumor, Adipose Tissue and Serum in Mice with Diet-Induced Obesity
Year: 2025
Type: dissertation
Abstract: Women with obesity are proven to be at a higher risk of triple negative breast cancer (TNBC) development. Understanding obesity's effect on the expression of TNBC-associated genes could allow for the development of clinical interventions against tumor progression and metastatic growth. MicroRNAs (miRNAs) play a key role in the transcriptional regulation of gene expression. They can be transported out of cells via small, membrane-enclosed nanoparticles called extracellular vesicles (EVs). This research aims to evaluate the EV-derived miRNAs extracted from the mammary tumor, visceral adipose tissue (VAT), and serum of diet-induced obese (DIO) and control mice. We hypothesize that differentially expressed miRNAs in EVs isolated from the tissues of mice with obesity will increase cancer cell viability and proliferation through upregulation of genes related to growth and differentiation. Female C57BL/6 mice were randomized to receive either a control or DIO diet. At the onset of obesity in the DIO group, mammary tumor growth was induced in both groups by orthotopically injecting metMWntlung cells (a murine model of metastatic TNBC). These EVs were purified and the miRNA content was analyzed by small RNA sequencing. Differential miRNA expression was analyzed using DESeq2, followed by in silico target gene identification via miRTargetLink 2.0, miRTarBase, and miRDB. Pathway analysis was conducted using DAVID. To validate functional relevance, metMWntlung cells were reverse transfected with mimics and inhibitors of select miRNAs, followed by RNA isolation, qPCR, and MTT assays to assess gene expression and cell viability. DAVID analysis revealed enrichment in carcinogenesis-related pathways. In vitro assays confirmed that modulating miRNA expression affected cancer cell viability and associated target gene expression. These findings suggest that obesity-associated EV-derived miRNAs may contribute to TNBC progression and offer potential targets for therapeutic intervention.
DOI: 10.17615/hz2z-9460
Author: Grant, Cameron
Institution: University of North Carolina at Chapel Hill
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W6887915983
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