Secretion and intracellular degradation of collagen in cultures of normal and SV-40-transformed human fibroblasts

AbstractWith a pulse-chase technique, secretion and intracellular degradation of collagen were investigated in human cultured normal and SV-40-transformed fibroblasts. Normal cells at a proliferative phase of growth secreted collagen more actively than the stationary phase (resting) cells. Transformed fibroblasts secreted protein at a lower rate than both normal cell types. Resting and dividing normal cells displayed no differences in the rates of intracellular collagen degradation at the various stages of the chase period. Transformed cells did not differ from the normal ones in collagen degradation rates at the first hour of the chase period while at later times in the chase period, the total amount of degraded collagen was reduced by 20–30% in the transformed vs normal cultures. The data are discussed in the view of possible relations between the various mechanisms of intracellular transport and degradation of collagen