[Adhesion of hepatocellular carcinoma cells to collagen IV coated surfaces]

To quantitatively describe the adhesion of hepatocellular carcinoma (HCC) cells and hepatocytes to collagen IV/laminin coated surfaces and to investigate the relevance of cell adhesion forces to the coating concentration of collagen IV and, when laminin was co-coated along with collagen IV, the incorporation concentration of laminin.

A stepwise coating protocol was adopted to prepare the collagen IV/laminin coated surfaces, in which poly-D-lysine and collagen IV/laminin were successively coated onto glass surfaces and finally, bovine serum albumin was used to block the non-specific adhesion. Cell adhesion forces were measured by means of micropipette aspiration technique.

Cell adhesion forces showed good dependence on the coating concentration of collagen IV. However, the amplitude for the increase of adhesion forces of HCC cells (202 x 10(-10) N, 26%) was far more less than that for hepatocytes(1,566 x 10(-10) N, 742%) when coating concentration increased from 1 microgram/ml to 5 micrograms/ml. No further increase in the adhesion forces of HCC cells was observed when the coating concentration of collagen IV increased beyond 2 micrograms/ml. The incorporation of laminin along with 2 micrograms/ml collagen IV did not readily result in an increase in the adhesion forces of the two kinds of cells to the surfaces. Among the concentration of laminin tested, only in certain concentration(0.625 microgram/ml or 1.25 micrograms/ml) did the incorporation of laminin along with 2 micrograms/ml collagen IV lead the adhesion forces of hepatocytes and HCC cells to the coated surfaces to reach their corresponding maximum values, otherwise this incorporation led the adhesion forces to decrease.

The present method is efficient in investigating cell-matrix adhesion. The cell adhesion behavior to collagen IV for HCC differs obviously from those for normal hepatocytes. Laminin might be an important factor for the regulation of cell adhesion forces to matrix components.