Mechanism of action[edit]
Anthracyclines have four mechanisms of action:
Inhibition of DNA and RNA synthesis by intercalating between base pairs of the DNA/RNA strand, thus preventing the replication of rapidly growing cancer cells.[7]
Inhibition of topoisomerase II enzyme, preventing the relaxing of supercoiled DNA and thus blocking DNA transcription and replication. Some sources say that topoisomerase II inhibitors prevent topoisomerase II turning over which is needed for dissociation of topoisomerase II from its nucleic acid substrate. In other words, topoisomerase II inhibitors stabilise the topoisomerase II complex after it has broken the DNA chain. This leads to topoisomerase II mediated DNA-cleavage, producing DNA breaks.[8] The binding of topoisomerase II inhibitor prevents DNA repair by ligase.[9][10]
Iron-mediated generation of free oxygen radicals that damage the DNA, proteins and cell membranes.[7]
Induction of histone eviction from chromatin that deregulates DNA damage response, epigenome and transcriptome.[11]