Anthracycline resistance in childhood leukemia

Clinical resistance to anthracyclines, and the cardiotoxicity associated with the use of the conventional drugs daunorubicin (DNR) and doxorubicin (DOX), initiated the search for new analogues and structurally related drugs. We, use the cell culture drug resistance MTT assay to study the in vitro cytotoxicity of anthracyclines in childhood leukemia. Here, we summarize our results regarding these agents. We also report that relapsed ALL samples were significantly more resistant to DNR, DOX, and mitoxantrone (MIT) than untreated ALL samples, while the antileukemic activity of idarubicin (IDR) and especially of aclarubicin (ACR) was not significantly decreased in relapsed ALL.