THE EFFECTS OF 13-CIS RETINOIC ACID ON SQUAMOUS-CELL CARCINOMA PROLIFERATION AND ADHESION TO EXTRACELLULAR-MATRIX PROTEINS

To understand the role of retinoids in chemoprevention, the authors ex amined the effects of 13-cis retinoic acid (cRA) on squamous cell carc inoma proliferation and adhesion to extracellular matrix proteins. The antiproliferative effects of cRA were first seen on day 11 (66% inhib ition) and progressed through day 19 (96% inhibition). Using an adhesi on assay, the authors then investigated the effects of cRA and transfo rming growth factor-beta(1) (TGF-beta(1)) on cellular adhesion to puri fied type TV collagen, fibronectin, and laminin matrices. Cells treate d for 4 days with TGF-beta(1) increased adhesion by 15% to 29%, and ce lls treated with cRA increased adhesion by 19% to 39%. However, the us e of cRA alone resulted in a decrease in adhesion when tumor cells wer e treated for 7 days (20% to 32%) and 15 days (25% to 40%). The author s also discuss how cRA acts as a differentiating agent on squamous cel l carcinoma.