Retinoid effects have been well studied in different cellular models, and their in vitro action on
breast cancer is well known. Much less is known about the function of the different
retinoid receptors in mediating
retinoid activity in this and other cellular models. In order to better understand these
biological mechanisms, several synthetic compounds have been produced, that have specific binding affinity for selected
nuclear receptors, and their effect has been evaluated and confronted with that of classic compounds able to bind to different receptors. The aim of this study was the evaluation of the
biological activities in
breast cancer cell lines of one of these new compounds,
AGN 193836, with a very selective binding affinity (selective agonist
retinoid) for one single
retinoic acid receptor (RAR alpha), in respect to a classic
retinoid able to bind to a broad spectrum of
retinoic acid receptors (pan-agonist
retinoid), 9cRA. Our results clearly indicate that the selective
retinoid retains most of the
biological activities of the pan-agonist compound, but its effect is probably aggravated by fewer side-effects in vivo: This evidences indicate that selective-agonist
retinoids are an interesting research field for the future, not only because of their speculative interest, but also in view of future clinical applications.