The MYB oncogene can suppress apoptosis in acute myeloid leukemia cells by transcriptional repression of DRAK2 expression

RNA interference-mediated suppression of MYB expression promoted apoptosis in the AML cell line U937, without affecting expression of the anti-apoptotic MYB target BCL2. This was accompanied by up-regulation of the pro-apoptotic gene DRAK2 and stimulation of caspase-9 activity. Moreover, RNA interference-mediated suppression of DRAK2 in U937 cells alleviated apoptosis induced by MYB down-regulation. Finally ChIP assays showed that in U937 cells MYB binds to a conserved element upstream of the DRAK2 transcription start site. Together, these findings identify a novel mechanism by which MYB suppresses apoptosis in an AML model cell line.