Abstract
New-type inducers of differentiation of human promyelocytic leukemia cells HL-60, i.e., 4- (5, 6, 7, 8-tetrahydro-5, 5, 8, 8-tetramethyl-2-naphthalenylcarbamoyl) benzoic acid (Am 80) and (E) -4- [3- (3, 5-di-tert-butylphenyl) -3-oxo-l-propenyl] benzoic acid (Ch 55), suppress c-myc expression as all-trans-retinoic acid (RA) does. The decreased level of c-myc expression was detected within 5-14 h after the start of treatment, and preceded morphological differentiation and functional differentiation measured in terms of nitroblue tetrazolium (NBT) reduction. Treatment of HL-60 cells with 0.1 μm Am 80, Ch 55 or RA for 96 h caused more than 90% suppression of c-myc expression and around 10-fold increase in the percentage of NBT-positive cells.
