N. Benbaruch et al., C-MYC DOWN-REGULATION IN SURAMIN-TREATED HL-60 CELLS PRECEDES GROWTH-INHIBITION BUT DOES NOT TRIGGER DIFFERENTIATION, Molecular pharmacology, 46(1), 1994, pp. 73-78
Down-regulation of c-myc mRNA expression is linked to growth arrest an
d the state of differentiation of hematopoietic cells. We showed that
treatment of HL60 cells with suramin results in a rapid reduction of c
-myc expression followed by an inhibition of cell growth. Both c-myc m
RNA and protein levels decreased by day 1 of treatment, and, by day 4,
only 10% of control c-myc protein levels were detected. In contrast t
o retinoic acid, dimethyl sulfoxide, and 12-O-tetradecanoylphorbol-13-
acetate treatment, however, exposure of HL60 cells to suramin did not
result in the induction of differentiation. These results demonstrate
that suramin modulates c-myc levels in HL60 cells and that the down-re
gulation of c-myc is not sufficient to trigger differentiation toward
either granulocytic or monocytic lineages.