3D Nanofibrillar Matrix Stiffness Modulates Extracellular Vesicle Cargo and Pro-Tumour Functions.

Area of Science:

• Biomedical Engineering
• Cancer Biology
• Cell Biology

Background:

• Extracellular matrix (ECM) stiffness and extracellular vesicles (EVs) are key drivers of tumor progression.
• Current research often uses 2D models, failing to replicate the complex 3D tumor microenvironment.
• The interplay between ECM mechanics and EV biology in 3D settings is not well understood.

Purpose of the Study:

• To investigate how ECM stiffness influences EV properties and functions within a biomimetic 3D model.
• To characterize the cargo and biological effects of EVs derived from matrices of varying stiffness.
• To elucidate the signaling pathways activated by stiff matrix-derived EVs in recipient cells.

Main Methods:

• Development of a 3D nanofibrillar cellulose nanofibril hydrogel ECM model.
• Isolation and characterization of EVs from soft (SoEVs) and stiff (StEVs) matrices.
• Assessment of EV cargo (proteins, microRNAs) and functional effects on tumor cells (proliferation, migration).
• In vivo studies in mouse models and multi-omics analyses to identify signaling pathways.

Main Results:

• EVs from stiff matrices (StEVs) displayed unique physicochemical properties and cargo compared to EVs from soft matrices (SoEVs).
• StEVs significantly enhanced tumor cell proliferation and migration, and promoted tumor growth in vivo.
• StEVs were found to activate the MAPK/ERK1/2 signaling pathway in recipient cells.

Conclusions:

• ECM stiffness mechanistically regulates EV-mediated intercellular communication in 3D tumor microenvironments.
• Matrix stiffness shapes the cargo and pro-tumorigenic functions of EVs.
• Understanding these mechanobiological interactions is crucial for developing novel cancer therapies.