1,25-Dihydroxyvitamin D3Primes Acute Promyelocytic Cells for TPA-Induced Monocytic Differentiation through Both PKC and Tyrosine Phosphorylation Cascades

NB4 cells are the only in vitro model of differentiation in acute promyelocytic leukemia (APL). Although these cells respond to all-trans-retinoic acid to form neutrophils, our group has recently shown that these cells are capable of terminal monocytic differentiation in response to combined treatment with 1,25-dihydroxyvitamin D3 (1,25 D3) and 12-O-tetradecanoylphorbol-13-acetate (TPA). We show here that the agents need not be present …