Modeling force application configurations and morphologies required for cancer cell invasion

Area of Science:

• Biophysics
• Cell Biology
• Cancer Research

Background:

• Cellular interactions with the microenvironment drive migration and cancer invasion.
• Invasive cancer cells indent gels to cell-scale depths (up to 10 μm), while non-invasive cells indent minimally (<0.7 μm).
• Significant cell indentation correlates with increased invasiveness and metastatic risk.

Purpose of the Study:

• To evaluate the force magnitudes and configurations required for cell-scale gel indentations.
• To model the mechanobiological interactions underlying cancer cell invasion.
• To differentiate the mechanical requirements for invasive versus non-invasive cell indentation.

Main Methods:

• Developed finite element models using experimental cell/gel morphologies, mechanics, and force data.
• Simulated forces applied to soft, impenetrable gels.
• Compared model predictions with experimental observations of cell indentation depths.

Main Results:

• In-plane traction forces alone produced only small-scale indentations (<0.7 μm), consistent with non-invasive cells.
• Adding a normal force component resulted in cell-scale indentations (matching invasive cancer cells).
• Normal stresses, rather than contact area or morphology, primarily determine indentation depth.

Conclusions:

• Normal mechanical stresses are essential for deep cell penetration into soft substrates.
• The model elucidates the mechanical basis for invasive cell morphologies and behaviors.
• Findings provide a foundation for modeling complex multicellular invasion dynamics.