Epigenetic deregulation is involved in
acute myeloid leukemia (AML) pathogenesis and epigenetic targeting drugs are in clinical trial. Since the first results with
histone-deacetylase inhibitors in AML are controversial, novel single and combined treatments need to be explored. It is tempting to combine
chromatin-targeting drugs. SUV39H1, the main methyl-
transferase for
lysine 9 tri-methylation on
histone H3, interacts with oncogenes involved in AML and acts as a transcriptional repressor for hematopoietic differentiation and immortalization. We report here that pharmacological inhibition of SUV39H1 by
chaetocin induces apoptosis in
leukemia cell lines in vitro and primary AML cells ex vivo, and that it interferes with
leukemia growth in vivo.
Chaetocin treatment upregulates
reactive oxygen species (ROS) production as well as the transcription of
death-receptor-related genes, in a ROS-dependent manner, leading to
death receptor-dependent apoptosis. In addition to its direct inhibition by
chaetocin, SUV39H1 is indirectly modulated by
chaetocin-induced ROS. Accordingly,
chaetocin potentiates other anti-AML drugs, in a ROS-dependent manner. The decryption of a dual mechanism of action against AML involving both direct and indirect SUV39H1 modulation represents an innovative read-out for the anticancer activity of
chaetocin and for its synergy with other anti-AML drugs, suggesting new therapeutic combination strategies in AML.