Inhibition of DNA restriction enzyme digestion by antracyclines

The inhibition of restriction enzyme digestion of lambda phage DNA by anthracyclines (i.e., adriamyci daunomyci epirubici idarubicin and esorubicin) commonly used in the treatment of human leukemia and cancer has been studied in vitro. The anthracyclines used inhibit DNA digestion by Sma AvaiI HaeII HhaI and HpaI which cut DNA at guanine-cytosine (G-C) sequence site and by EcoRI*, which cut DNA at adenine adenine-thymine thymine (AATT) sequence sites. Adriamycin completely inhibits DNA restriction by the indicated enzyme daunomyci epirubicin and idarubicin determine only a partial inhibitio while esorubicin does not inhibit DNA restriction at all. An attempt is made to correlate the extent of the in vitro interaction between anthracyclines and DNA to in vivo cardiotoxicity.