Retinoids, retinoid-responsive genes, cell differentiation, and cancer.

Abstract

Vitamin A (retinol), its natural and synthetic derivatives, and its metabolites are known collectively as retinoids (Fig. 1). Vitamin A is required in the diets of vertebrate animals, and vitamin A is oxidized to RA,2 a compound that exerts dramatic effects on vertebrate development and cell differentiation. In addition, retinoids can inhibit or reverse the process of malignant transformation in some cell types. Most of the actions of retinoids are thought to be mediated by two different types of nuclear retinoic acid receptors. Smaller high-affinity CRABPs may also function to modulate the effects of RA within cells.