BMP-6 and retinoic acid synergistically differentiate the IMR-32 human neuroblastoma cells
Sumantran, V.N.; Brederlau, A.; Funa, K.
Anticancer Research 23(2b): 1297-1303
2003
ISSN/ISBN: 0250-7005 PMID: 12820386 Document Number: 560572
Background: We studied the effects of all-trans retinoic acid (ATRA) and Bone morphogenetic protein-6 (BMP-60 on neuronal differentiation of IMR-32 cells. Materials and Methods: Immunostaining, Western blotting and MTT assays were used to characterize the survival and neuronal phenotype of IMR-32 cells differentiated by ATRA +- BMP-6. Results & Conclusion: ATRA, BMP-6 and ATRA + BMP-6 treatments each induced dopaminergic neuronal differentiation of the IMR-32 cells as judged by expression of GAP-43, tyrosine hydroxylase and microtubule-associated protein 2ab. ATRA alone induced strong biochemical differentiation, whereas ATRA + BMP-6 treatment synergistically enhanced neurite outgrowth and morphological maturation. When compared with undifferentiated controls, ATRA induced Bcl-2 expression, while loss of Bax expression was observed only in cells differentiated by ATRA + BMP-6. The high Bcl-2/Bax ratio in cells differentiated by ATRA and ATRA + BMP-6, respectively, correlated with the survival of these cells in serum-free media. Upon re-exposure to fiesh serum lacking factors, only cells differentiated by ATRA + BMP-6 were unable to resume cell division. In concordance with their morphological maturation, these cells were terminally differentiated when compared with cells differentiated by separate treatment with ATRA or BMP-6.