Chemistry and mechanism of action of bleomycin

Bleomycin (BLM) is an antitumoral antibiotic active against various animal and human tumors. BLM causes a lot of biological effects characteristic of drugs which attack the DNA in cells. The nature of DNA damage consists of the release of bases and single and double-strand breaks. The Fe (II) is a necessary cofactor in the reaction of BLM with DNA. BLM is effective principally against non-dividing cells and against cells in mitotic phase, G2 and S. The various contents of BLM inactivating enzymes in tissues can explain the particular toxicity and therapeutic activity of this drug.