Obese adipose tissue extracellular vesicles activate mitochondrial fatty acid ?-oxidation to drive colonic stemness
Obesity increases the risk of colorectal cancer (CRC) development and accelerates disease progression. Obesity adversely affects the visceral adipose tissue (VAT) leading to increased secretion of extracellular vesicles (EVs). However, the crosstalk between VAT and CRC tumor cells still remains unclear. EVs are lipid-membraned particles that transfer cargo to and/or induce signaling in other cells. Here, human VAT-derived non-obese (N-OB) and obese (OB) EVs through proteomics and investigated the functional interaction between CRC cells and EVs through RNA-seq analysis of EV-treated CRC cells. EVs were isolated from VAT obtained from obese (BMI>30) and non-obese patients (BMI<30). Unbiased proteomics revealed that compared to N-OB EVs, OB EVs were enriched with glycolytic enzymes like triose phosphate isomerase (TPI1). This enrichment was associated with increased TPI1 protein levels in CRC cells and elevated glycolytic activity. OB EV-treated cells also exhibited increased stemness-associated genes, 3D-spheroid formation and Apcmin/+ tumoroid self-renewal capacity. In vivo, mice with an adipocyte-specific knockout of EV cargo sorting protein, Tsg101 (Tsg101?Ad), have altered EV cargo composition with reduced glycolytic enzyme levels. Functionally, Tsg101?Ad-EVs were able to protect against high-fat diet (HFD)-induced increase in glycolysis and stem-like ability. Moreover, Apcmin/+:Tsg101?Ad mice were protected against HFD-induced enhanced tumorigenesis. Collectively, this study identifies adipocyte EVs, and its metabolic cargo, as an important regulator of CRC cell metabolism and function, promoting intestinal tumorigenesis. Overall design: Human CRC cell line HCT-116 was treated with vehicle, N-OB EV (BMI 25) and OB-EV (BMI 46) for 48 hrs. RNA was isolated for RNA-seq, with n=3 TECHNICAL REPLICATES.