c-myc Down-regulation in suramin-treated HL60 cells precedes growth inhibition but does not trigger differentiation.
Down-regulation of c-myc mRNA expression is linked to growth arrest and 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 mRNA 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 to 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-regulation of c-myc is not sufficient to trigger differentiation toward either granulocytic or monocytic lineages.
Ben-Baruch
N
N
Laboratory of Biological Chemistry, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892.
Reinhold
W C
WC
Alexandrova
N
N
Ichinose
I
I
Blake
M
M
Trepel
J B
JB
Zajac-Kaye
M
M
D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics; D002455:Cell Division / Q000187:drug effects / Q000235:genetics; D015536:Down-Regulation; D016259:Genes, myc; D006801:Humans; D011519:Proto-Oncogenes; D012333:RNA, Messenger / Q000378:metabolism; D013498:Suramin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
D012333:RNA, Messenger; D013498:Suramin