Micro tensile tester measurement of biomechanical properties and adhesion force of microtubule-polymerization-inhibited cancer cells

J Mech Behav Biomed Mater. 2024 Aug:156:106586. doi: 10.1016/j.jmbbm.2024.106586. Epub 2024 May 22.

Abstract

Both mechanical and adhesion properties of cancer cells are complex and reciprocally related to migration, invasion, and metastasis with large cell deformation. Therefore, we evaluated these properties for human cervical cancer cells (HeLa) simultaneously using our previously developed micro tensile tester system. For efficient evaluation, we developed image analysis software to modify the system. The software can analyze the tensile force in real time. The modified system can evaluate the tensile stiffness of cells to which a large deformation is applied, also evaluate the adhesion strength of cancer cells that adhered to a culture substrate and were cultured for several days with their adhesion maturation. We used the modified system to simultaneously evaluate the stiffness of the cancer cells to which a large deformation was applied and their adhesion strength. The obtained results revealed that the middle phase of tensile stiffness and adhesion force of the microtubule-depolymerized group treated with colchicine (an anti-cancer drug) (stiffness, 13.4 ± 7.5 nN/%; adhesion force, 460.6 ± 258.2 nN) were over two times larger than those of the control group (stiffness, 5.0 ± 3.5 nN/%; adhesion force, 168.2 ± 98.0 nN). Additionally, the same trend was confirmed with the detailed evaluation of cell surface stiffness using an atomic force microscope. Confocal fluorescence microscope observations showed that the stress fibers (SFs) of colchicine-treated cells were aligned in the same direction, and focal adhesions (FAs) of the cells developed around both ends of the SFs and aligned parallel to the developed direction of the SFs. There was a possibility that the microtubule depolymerization by the colchicine treatment induced the development of SFs and FAs and subsequently caused an increment of cell stiffness and adhesion force. From the above results, we concluded the modified system would be applicable to cancer detection and anti-cancer drug efficacy tests.

Keywords: Cancer cell; Cell biomechanics; Mechanical properties; Mechanobiology; Micromanipulation.

MeSH terms

  • Biomechanical Phenomena / drug effects
  • Cell Adhesion* / drug effects
  • Colchicine / pharmacology
  • HeLa Cells
  • Humans
  • Materials Testing
  • Mechanical Phenomena
  • Microtubules* / drug effects
  • Polymerization / drug effects
  • Tensile Strength*

Substances

  • Colchicine