Vitamin A receptor in cancers and in vitro-transformed epithelial cells of the rat urinary bladder: its implication in the preventive effect of vitamin A on in vitro keratinization.
Cellular retinol-binding protein (CRBP) in cancers and in vitro-transformed epithelial cells of the ACI/N rat urinary bladder was assayed with radiolabeled retinol by sucrose density gradient centrifugation. CRBP was detected in abundance in tumor tissues of all 5 transplantation bladder cancer lines. However, this protein was below the limits of detection in bladder cancer cells of culture lines that had originated from the same primary cancers as the corresponding transplantation lines. CRBP was detected in small quantity in in vitro-transformed epithelial cells of a culture line but it was absent in another line of similar origin. The addition of retinol to the culture medium prevented the in vitro keratinization of CRBP-positive cells but it had no effect on the keratinization of CRBP-negative cells.
D000818:Animals; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D007633:Keratins / Q000378:metabolism*; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000378:metabolism; D051381:Rats; D012177:Retinol-Binding Proteins / Q000032:analysis / Q000494:pharmacology* / Q000502:physiology; D054840:Retinol-Binding Proteins, Cellular; D014184:Transplantation, Homologous; D001743:Urinary Bladder / Q000166:cytology; D001749:Urinary Bladder Neoplasms / Q000378:metabolism*
D012177:Retinol-Binding Proteins; D054840:Retinol-Binding Proteins, Cellular; D007633:Keratins