Extracellular matrix physical properties regulate cancer cell morphological transitions in 3D hydrogel microtissues

Area of Science:

• Biophysics
• Cell Biology
• Cancer Research

Background:

• Solid tumor cells exhibit diverse morphologies linked to progression.
• Factors influencing cell morphology in response to the extracellular matrix (ECM) are poorly understood.
• Understanding these factors is crucial for modeling tumor invasion and developing targeted therapies.

Purpose of the Study:

• To investigate how extracellular matrix (ECM) mechanics regulate solid tumor cell morphology in 3D.
• To develop and validate a theoretical model predicting cell morphology based on ECM properties.
• To establish a robust experimental platform for studying cell-ECM interactions in triple-negative breast cancer (TNBC) cells.

Main Methods:

• Developed a theoretical mechanical energy model based on the minimum energy principle.
• Used MDA-MB-231 breast cancer cells encapsulated in 3D hydrogels of controlled stiffness.
• Employed chemically distinct yet mechanically matched composite matrices to isolate physical effects.

Main Results:

• Theoretical model predicted cell morphology minimization of total cell-ECM system energy.
• In vitro experiments confirmed model predictions: elongated morphology in soft ECMs, clustered morphology in stiff ECMs.
• ECM stiffness, not chemical properties, governed cell morphology transitions.

Conclusions:

• ECM physical properties significantly dictate solid tumor cell morphology and invasion behavior.
• The study provides a biophysical model for cell invasion and a platform for TNBC research.
• Findings have implications for personalized medicine and the development of tailored cancer models.