Presence of cellular rentinol and retinoic acid binding proteins in experimental rumors.

Cellular retinol and retinoic acid binding proteins were detected in mouse skin papillomas, human adenocarcinoma HAD-1, Dunning Leukemia, Walker 256 carcinosarcoma and mammary adenocarcinoma MAC-1. A chondrosarcoma and Sarcoma 180 apparently contain only the cellular retinoic acid binding protein. Neither protein could be detected in Ehrlich carcinoma and L1210 leukemia. The presence of these proteins might be necessary for sensitivity to retinoid therapy.