ABSTRACT
Retinoids are clinically useful agents in dermatology for the treatment of severe acne, psoriasis, and other keratinizing dermatoses. Retinoids or cytokines given as monotherapy have a limited usefulness in cancer therapy. Experimentally, retinoids as well as cytokines exert an antitumor effect in cell cultures of human transformed cell lines, in organ cultures, and in transplantable or chemically induced animal tumors. Many more clinical investigations will have to be carried out to detect which cytokine in combination with which retinoid will result in useful therapeutic effectiveness in a particular neoplastic diseases. Starting from the prototype of all-trans-retinoic acid, a variety of synthetic retinoids were selected for investigation. The antitumor effect of retinoids has, in addition to differentiation induction, been attributed to the direct impact on the rate of cell proliferation. Frequently, a synergistic effect on proliferation inhibition was demonstrated when cytokines and retinoids were administered in combination.
