Probing the Adhesion of Hepatocellular Carcinoma HepG2 and SK-Hep-1 Cells

Carcinoma cell differentiation stage is an important indicator of cell behavior. For example, cell mobility is much higher for poorly-differentiated hepatocellular carcinoma SK-Hep-1 cells than for well-differentiated HepG2 cells. In this study, we have cultured HepG2 and SK-Hep-1 cells on chemically patterned polydimethylsiloxane (PDMS) substrates to observe differences in the adhesion properties and cell structure that occur due to the patterns. Both cell lines showed a preference for the hydrophobic regions on the patterned PDMS surface with SK-Hep-1 cells achieving a higher density than HepG2 for the same cell-count solutions. Further, SK-Hep-1 cells adopted the square or hexagonal shape of the surface patterns while HepG2 cells maintained their more rounded shape. AFM force measurement arrays were also performed on the cell surfaces to measure and map adhesion values between the tip and cell surface membrane. These results demonstrate that, in addition to cell shape and size, adhesion expression in hepatocellular carcinoma cells is differentiation stage dependent. Further, the ability of the SK-Hep-1 cells to adopt the shape of the substrate pattern indicates they are more structurally labile, which may contribute to their higher mobility.