DNA damage independent inhibition of NF-κB transcription by anthracyclines

Transcriptional programs leading to induction of a large number of genes can be rapidly initiated by the activation of only few selected transcription factors. Upon stimulation of macrophages with microbial-associated molecular patterns (MAMPs), the activation of the nuclear factor kappa B (NF-κB) family of transcription factors triggers inflammatory responses that, left uncontrolled, can lead to excessive inflammation with life-threatening consequences for the host. Here we identify and characterize a novel effect of Anthracyclines, a class of drugs currently used as potent anticancer drugs, in the regulation of NF-κB transcriptional activity in BMDMs, in addition to the previously reported DNA damage and histone eviction. Anthracyclines, including Doxorubicin, Daunorubicin and Epirubicin, disturb the complexes formed between the NF-κB subunit RelA and its DNA binding sites, to limit NF-κB-dependent gene transcription during inflammatory responses, including of pivotal pro-inflammatory mediators such as TNF. We observed that suppression of inflammation can also be mediated by Aclarubicin, Doxorubicinone and the newly developed Dimethyl-doxorubicin, which share anticancer properties with the other Anthracyclines, but do not induce DNA damage in the tested concentrations. This novel mechanism of action of Anthracyclines, contributing to the reduction of inflammation, is thus independent of the activation of DNA damage responses and may be relevant for the development of novel strategies targeting immune-mediated inflammatory diseases.