Correlation of the cell mechanical behavior and quantified cytoskeletal parameters in normal and cancerous breast cell lines.

Background: Cancerous transformation of cells affects their mechanical behavior and cytoskeleton structure.

Objective: The objective of this research is to investigate a correlation between mechanical properties and cytoskeletal structure features in cancer cell formation.

Methods: Micropipette aspiration was used to compare mechanical properties of normal (MCF10A) and cancerous (T47D) epithelial breast cell lines. Immunofluorescence and confocal microscopy were employed for staining and imaging F-actin and microtubules, and quantifying their fluorescent intensity, anisotropy and fiber distribution.

Results: Results indicated higher F-actin intensity (43%) and anisotropy (50%) in normal cells compared to cancer cells, although there was no difference in the microtubules intensity between cell lines. Furthermore, reductions of cortex thickness and actin layer index (60%) were observed in suspended cancer cells compared to normal cells. Changes in cell physical properties induced by cancer were attributed to microtubules. The arranged fibrous structure of microtubules in normal cells was replaced by a disorganized structure in cancer cells. Cancerous cells were about four times softer with higher creep compliance compared to normal cells.

Conclusions: Results of this study confirmed that alterations in cell mechanical properties induced by cancer are highly correlated with changes in F-actin and microtubule content and arrangement. It is suggested that such changes can enhance our knowledge of cancer initiation and progression.