Correlation of tumorigenicity with resistance to growth inhibition by cis-hydroxyproline

cis-Hydroxyproline, an inhibitor of collagen deposition, was examined for its effect on the growth of a variety of tumorigenic and non-tumorigenic cells. Virally, chemically, and spontaneously transformed murine cell lines were found to be less sensitive to cell spreading and growth inhibition by cis-hydroxyproline (CHP) than were their non-tumorigenic counterparts. The non-tumorigenic lines exhibited a higher rate of collagen accumulation in culture than the tumorigenic cell lines. The rate of collagen accumulation in culture without CHP and the growth inhibition by CHP were directly related. These results suggest that normal but not tumorigenic cells may require synthesis of an extracellular substrate containing collagen to support spreading and growth.