Comparative studies of collagen lattice contraction utilizing a normal and a transformed cell line

Differences between the behavior of cultured rat skin fibroblasts and that of a line of transformed rat sarcoma cells incorporated into a polymerized collagen lattice were examined. Fibroblast-populated collagen lattices (FPCL) were manufactured. Within 24 to 48 hr after manufacture, both cell lines reduced lattice size by a process known as lattice contraction. Contraction occurred more rapidly in both cell lines when the media were supplemented with 25% serum rather than the usual concentration of 10% serum. Similar growth patterns were observed with transformed cells within collagen lattices and on plastic surfaces. Normal rat fibroblasts were found to contract lattices faster than transformed cells. At the end of a 2-week period, the final contracted size of the transformed cell lattice was the same as that of normal cell lattices. The cellular density of transformed cells within the FPCL was eight times greater than that of FPCL made with normal rat cells. Normal rat fibroblasts elongated and flattened more, and organized the collagen matrix to a greater degree, than did transformed cells. In this instance, therefore, lattice contraction was shown to be linked more to the process of fibroblast elongation and collagen fiber organization than to cell number or density.