The viscoelastic behaviors of several kinds of cancer cells and normal cells.

The purpose of this study was to investigate the viscoelastic behaviors of cancer cells and normal cells using the micropipette aspiration technique combined with the standard linear viscoelastic solid model. The viscoelastic behaviors of pairs of cell lines (human skin cells and human skin cancer cells, human fetal lung fibroblasts and human lung cancer cells, human mammary fibroblasts and human breast cancer cells, and human hepatocyte cells and human hepatocellular carcinoma cells) were tested by the micropipette aspiration technique. The cellular viscoelastic parameters (the instantaneous modulus E0 , the equilibrium modulus associated with long term equilibrium E∞ , and the apparent viscosity μ) were calculated using a Kelvin standard linear viscoelastic solid model. The present results indicate that the cancer cells were easier to deform, and the viscoelastic parameters (E0 , E∞ , μ) of the cancer cells were significantly lower than their corresponding normal cells (P < 0.0001). The viscoelastic parameters (E0 , E∞ , μ) among some normal cells showed significant differences (P < 0.05), while the different cancer cells showed no significant differences (P > 0.05). These findings may be relevant for the identification and diagnosis of cancer cells as well as providing an explanation of this occurrence mechanism in cancer cells and cancer treatment.