ABSTRACT
Derivativesofvitamintermedretinoidsall-trans-retinoicacid(all-transareagroupofsignalingmoleculesthatareessentialforwidevariety
ofbiologicalprocessesincludingdifferentiation,epithelialhomeostasis, vision,andreproduction(1).Inthevertebrateembryo,all-trans-RAhasbeen implicatedinavarietyofprocesses,includingthespecificationoftheanteroposteriorbodyaxis(reviewedinRef.2),formationofthedevelopingnervous system(3-5),craniofacialdifferentiation(6),andHmbmorphogenesis(7,8).High concentrationsofretinoidshavebeenshowntobetoxicorseverelyteratogenic whenadministeredduringembryogenesisinaofvertebrates,including humans(9).Theteratologicalphenotypesincludemalformations,duplications, andhomeotictransformationsofstructures.Inadditiontotheseembryoniceffects, thereisalsoconsiderableevidencetosuggestthatretinoidshavepotentantiproliferativeeffectsandmaybeusefulinthetreatmentofhumandiseasessuchas cancer(1,10).
