Mechanical Properties of Colorectal Cancer Cells Determined by Dynamic Atomic Force Microscopy: A Novel Biomarker

Abstract

Colorectal cancer (CRC) has been addressed in the framework of molecular, cellular biology, and biochemical traits. A new approach to studying CRC is focused on the relationship between biochemical pathways and biophysical cues, which may contribute to disease understanding and therapy development. Herein, we investigated the mechanical properties of CRC cells, namely, HCT116, HCT15, and SW620, using static and dynamic methodologies by atomic force microscopy (AFM). The static method quantifies Young’s modulus; the dynamic method allows the determination of elasticity, viscosity, and fluidity. AFM results were correlated with confocal laser scanning microscopy and cell migration assay data. The SW620 metastatic cells presented the highest Young’s and storage moduli, with a defined cortical actin ring with distributed F-actin filaments, scarce vinculin expression, abundant total focal adhesions (FAK), and no filopodia formation, which could explain the lessened migratory behavior. In contrast, HCT15 cells presented lower Young’s and storage moduli, high cortical tubulin, less cortical F-actin and less FAK, and more filopodia formation, probably explaining the higher migratory behavior. HCT116 cells presented Young’s and storage moduli values in between the other cell lines, high cortical F-actin expression, intermediate levels of total FAK, and abundant filopodia formation, possibly explaining the highest migratory behavior.

Evaluation of gelatin-based hydrogels for colon and pancreas studies using 3D in vitro cell culture

“…Remarkably, actin-based protrusions known as filopodia were observed at the cell margins, which are likely associated with cell migration processes. 67,68 Filopodia are long and slender dynamic structures which can rapidly extend and retract in multiple orientations, enabling cells to perceive their microenvironment and establish connections with neighboring cells or surfaces. 69 Thus, the presence of filopodia on the surface of HCT-116 cells allow them to sense chemical cues eventually promoting cell motility.…”

Recent advances and biophysical applications of atomic force microscopy in cancer research: An overview

“…99,100) Insufficient cell transportation from the crypt, which is dependent on the APC protein, (HCT116, HCT15, and SW620). 104) The dynamic method enables the measurement of pliability, viscosity, and mobility, while the static technique measures Young's modulus. 104) The outcomes of confocal microscopy and migratory cell assays were correlated with the AFM results.…”

“…104) The dynamic method enables the measurement of pliability, viscosity, and mobility, while the static technique measures Young's modulus. 104) The outcomes of confocal microscopy and migratory cell assays were correlated with the AFM results. 104) SW620 metastatic cells had the highest Young's and storage moduli, a distinct cortical actin band with dispersed F-actin strands, little vinculin expression, lots of focal adhesions [FAK], and negligible filopodia growth, which could account for the reduced migratory tendency.…”

Atomic Force Microscopy Methods to Measure Tumor Mechanical Properties

“…Many AFM studies focus extensively on the nanomechanical characterization of cells to establish novel mechanical biomarkers. These “mechanobiomarkers” may provide insight into the progression of the disease, enhance cancer detection, as well as improve therapeutic strategies [ 57 , 58 , 59 ]. However, in addition to irreproducible measurements between different groups [ 41 ], clinicians are reluctant to adopt AFM-based single-cell nanomechanical characterization as a diagnostic tool because it often fails to capture the complexities of a tumor and the organ in which it is situated [ 18 ].…”