Decoding Hypoxia-Induced Metabolomic Changes in Breast Cancer EVs and Their Functional Effects on Cancer Cells

Area of Science:

• * Metabolomics
• * Cancer Biology
• * Extracellular Vesicles

Background:

• * Hypoxia is a hallmark of solid tumors, driving tumor progression and therapeutic resistance.
• * Extracellular vesicles (EVs) mediate intercellular communication and play roles in cancer development.
• * Metabolic reprogramming under hypoxia influences EV cargo and function.

Purpose of the Study:

• * To investigate metabolic alterations in EVs secreted by breast cancer cells under hypoxic conditions.
• * To determine the functional impact of these metabolically altered EVs on cancer cell behavior.
• * To identify specific metabolites within hypoxic EVs that contribute to tumor progression.

Main Methods:

• * Untargeted metabolomic analysis using Liquid Chromatography-Mass Spectrometry (LC-MS/MS).
• * Isolation and characterization of EVs from breast cancer cell lines (MDA-MB-231, MCF-7) cultured under normoxic and hypoxic conditions.
• * Assessment of EV homogeneity via Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Nanoparticle Tracking Analysis (NTA), and immunoblotting.
• * Functional assays measuring cancer cell migration, invasion, and epithelial-mesenchymal transition (EMT).

Main Results:

• * Metabolic extracts from hypoxic EVs significantly enhanced breast cancer cell migration, invasion, and EMT.
• * Metabolomic profiling identified over 400 annotated metabolites, with 48 significantly altered in hypoxic EVs.
• * Key upregulated metabolites in hypoxic EVs included riboflavin, 5,6-epoxy-8,11,14-eicosatrienoic acid, and furandicarboxylic acid.
• * Identified critical metabolites like N-acetyl-l-methionine and 5,10-methenyltetrahydrofolic acid potentially involved in cell proliferation, DNA damage, and epigenetic regulation.
• * Pathway analysis revealed increased aromatic amino acid and riboflavin metabolism in hypoxic EVs.

Conclusions:

• * Hypoxia induces significant metabolic reprogramming in breast cancer cell-derived EVs.
• * These metabolically altered EVs promote key hallmarks of tumor progression, including migration, invasion, and EMT.
• * Specific metabolites within hypoxic EVs may serve as potential therapeutic targets or biomarkers for breast cancer.