DeSUMOylation limits the rapid transcriptional reprogramming induced by anthracyclines in Acute Myeloid Leukemias
Genotoxicants have been used for decades as front-line therapies against cancer on the basis of their DNA-damaging actions. However, some of their non-DNA-damaging effects are also instrumental for killing dividing cells. We report here that the anthracycline Daunorubicin (DNR) but not the nucleoside analog Cytarabine, the two main drugs used to treat Acute Myeloid Leukemia (AML), induces rapid (3 hours) and broad transcriptional changes in AML cells. The regulated genes are particularly enriched in genes controlling cell proliferation and death, as well as inflammation and immunity. These transcriptional changes are preceded by DNR-dependent deSUMOylation of chromatin proteins, in particular at active promoters and enhancers. Surprisingly, accelerating deSUMOylation dampens DNR-induced transcriptional reprogramming. Quantitative proteomics shows that proteins that are deSUMOylated in response to DNR are mostly transcription factors, transcriptional co-regulators and chromatin organizers. Among them, the CCCTC-binding factor CTCF is highly enriched at SUMO-binding sites found in cis-regulatory regions. This is notably the case at the promoter of the DNR-induced NFKB2 gene. Although DNR does not modify CTCF binding on chromatin in general and at NFKB2 promoter in particular, it leads to a SUMO-dependent reconfiguration of chromatin loops engaging CTCF- and SUMO-bound NFKB2 promoter with distal cis-regulatory regions. Overall design: Cut&run targeting CTCF in HL60 cells treated with 1 µM DNR and 0.5 µM ML-792 for 2 hrs.