RETINOIC ACID CAUSES PREMATURE DESQUAMATION OF CELLS FROM CONFLUENT CULTURES OF STRATIFIED SQUAMOUS EPITHELIA

Cells from 2 types of stratified squamous epithelia were grown to confluence in vitro. Highly differentiated cells were shed into the culture medium at a constant rate for at least 4 wk, thus providing a unique system in which to study factors that influence desquamation. Retinoic acid (RA) decreased the rate of desquamation in calf esophagus epithelial cell (CEEC) cultures and increased the rate of desquamation in human foreskin epithelial cell (HFEC) cultures. Cells shed from CEEC and HFEC cultures treated with RA were less differentiated, as assessed by their protein/DNA ratio, than cells shed from control cultures. Retinoic acid may induce premature desquamation from stratified squamous epithelia.