doxorubicin

Doxorubicin binds directly to DNA via intercalation between base pairs on the DNA helix. Doxorubicin also inhibits DNA repair by inhibiting topoisomerase II. These actions result in the blockade of DNA and RNA synthesis and fragmentation of DNA.

Doxorubicin is also a powerful iron-chelator. The iron-doxorubicin complex can bind DNA and cell membranes producing free radicals that immediately cleave DNA and cell membranes. Although maximally cytotoxic in S phase, doxorubicin is not cell cycle-specific.