Retinoic acid-induced alterations of growth and morphology in an established epithelial line

Retinoic acid induced alterations in cellular growth, morphology, and adhesion in a human intestinal epithelial line. Inhibition of growth was dependent on cell density, with the greatest inhibition of growth observed at low cell density. As cells approached confluence, the extent of inhibition was diminished. Cells grown in the presence of retinoic acid appeared elongated and showed enhanced detachability with trypsin. Control cells grew in tight clusters with maximum cell-cell contact. This is in contrast to retinoic acid-treated cells which did not grow in clusters. In addition, it was observed that retinoic acid inhibited glycosaminoglycan biosynthesis. These observations are uniquely different from those reported for non-epithelial cells.