[3 retinoic acid isomers on proliferation and differentiation properties of APL cell line-NB4].

We examined the effect of three RA isomers, including ATRA, 13C-RA and 9C-RA, on the proliferation and differentiation properties of NB4 cells, a cell line established from APL patient and carrying the typical translocation t (15;17). Standard parameters such as cell morphology, cell growth curve, dynamics of cell cycle, expression of clusters of differentiation and reduction of nitro blue tetrazolium (NBT) were used to evaluate the effects of the three isomers. During the first 48 hours of RA treatment, the APL cell maturation was coupled with the cell proliferation. Moreover, significant differences of differentiation-induced effect among RA isomers were observed. ATRA showed better results than 13C-RA while 9C-RA functioned even better than ATRA. These data are helpful to understand the mechanisms, by which RAs induce promyelocytic leukemia cell differentiation and open a new prospect for the clinical use of novel retinoic acid isomers.