Retinoid therapy

Abstract

Vitamin A and it's analogs are collectively termed retinoids, and varieties of novel compounds have been newly synthesized for uses of cancer chemoprevention or of anti-carcinogenic therapy. Here, we describe two representative compounds: one is all-trans retinoic acids (ATRA) for induction-differentiation therapy of acute promyelocytic leukemia (APL), the other is acyclic retinoid (ACR) or one of polyprenoic acid derivatives without any cyclic structure in the molecule, but which has transactivation activity with nuclear retinoid receptor (retinoid-X receptor: RXR). This was originally found in our laboratory and proved to be clinically efficacious for prevention of second primary hepatocellular carcinoma after curative anatomical resection (N. Engl. J. Med. 334: 1561, 1996). A comparative study in-depth of these two distinct retinoid therapies will provide new insights into the molecular processes of carcinogenesis itself. Moreover, synergistic effects of interferon (IFN) with the retinoid therapies have been found in both clinical settings, and warrant further exploration to elucidate the basic interactions as well as to develop useful clinical applications in the future.