Deciphering the Role of AMPK in Regulating Integrin Profile of Tumor-Derived Exosomes as a Potential Antimetastatic Strategy

Abstract

Introduction: Cancer cell adapt their metabolic activity to survive in stressful environments with limited nutrients and oxygen. To sense and respond to nutrient cues, cells rely on a “fuel gauge” protein known as AMP-activated protein kinase (AMPK). While previous work has largely focused on AMPK’s role in cell metabolism, its role in metastasis is poorly defined. Interestingly, AMPK also regulates the membrane trafficking of integrins – key proteins in cell adhesion and migration. Recent studies have also shown that circulating integrins in exosomes are predictive of metastasis. Therefore, understanding the biology of AMPK signaling on the exosomal integrin profile not only allow for better cancer treatments but also help developing a potential predictive biomarker. I hypothesize that AMPK activation alters the integrin profile of exosomes in breast and endometrial cancer. Methods: Breast and endometrial cancer cells, MDA-MB-231 and HEC-1 respectively, will be cultured in full nutrient media conditions. 48 hours before exosome harvest, the media will be changed to minimal specialized media for extracellular vesicles (EV) collection. To induce AMPK activation, cells will be treated with limiting concentrations of glucose and glutamine, or with metabolic poisons 2-deoxyglucose (2-DG) and oligomycin. Total Exosome IsolationTM (TEI) solution will be used to enrich released exosomes that will be subjected to mass spectrometry to analyze the exosomal integrin profiles. Anticipated Results: Exosomes secreted from MDA-MB-231 and HEC-1 cells are expected to contain different exosomal integrin profile in both basal and induced AMPK activation conditions. It is anticipated that integrin subunits that promote metastatic and survival signaling such as αvβ5, α6β4, α6β1, will be upregulated in exosomes following AMPK activation. This could suggest tumor cells adapting to nutrient insufficiency by AMPK activation may present a more aggressive exosomal integrin profile to support cancer progression. Discussion: Understanding how metabolic cues such as nutrient insufficiency impact integrin content of tumour-derived exosomes can help identify novel metabolic drug targets to limit pro-survival and pro-metastatic signaling in primary breast tumors. Conclusion: This study investigates how AMPK activation modulates the exosomal integrin profile in breast and endometrial cancer cells, potentially uncovering predictive biomarkers and therapeutic targets for metastatic cancers.