Recapitulating the Size and Cargo of Tumor Exosomes in a Tissue-Engineered Model

Area of Science:

• Biomedical Engineering
• Cancer Biology
• Extracellular Vesicles

Background:

• Exosomes are crucial in cancer and as biomarkers.
• Current in vitro models (monolayer cultures) inadequately represent the tumor microenvironment's influence on exosome production.
• Understanding exosome regulation by the tumor microenvironment is essential for biomarker development.

Purpose of the Study:

• To develop and validate a 3D tumor model for studying exosome release and characteristics.
• To investigate the impact of the tumor microenvironment (3D structure, composition, stiffness) on exosome size and cargo.
• To analyze the interaction of exosomes with non-cancer cells in the bone niche.

Main Methods:

• Engineered a 3D tumor model using Ewing's sarcoma type 1.
• Compared exosomes derived from the 3D model with those from monolayer cultures and patient plasma.
• Analyzed exosome size distribution and cargo (EZH2 mRNA).
• Investigated the transfer of exosomal EZH2 mRNA to mesenchymal stem cells.

Main Results:

• Exosomes from the 3D model exhibited size distribution comparable to patient plasma exosomes, unlike those from monolayer cultures.
• Bioengineered tumors and patient plasma showed higher levels of EZH2 mRNA compared to monolayer cultures.
• EZH2 mRNA was successfully transferred from exosomes to surrounding mesenchymal stem cells.

Conclusions:

• A 3D tumor model can effectively recapitulate key properties of tumor-derived exosomes found in vivo.
• Tumor microenvironment significantly influences exosome characteristics, including size and mRNA cargo.
• EZH2 mRNA, found in exosomes from the 3D model and patient plasma, represents a potential transferable biomarker.