PURPOSE : The anthracyclines daunorubicin and doxorubicin and the epipodophyllotoxin etoposide are potent DNA cleavage-enhancing drugs that are widely used in clinical oncology ; however , myelosuppression and cardiac toxicity limit their use .
O O O B-ChemicalEntity B-ChemicalEntity O B-ChemicalEntity O O B-ChemicalEntity B-ChemicalEntity O O O O O O O O O O O O O O O B-DiseaseOrPhenotypicFeature O B-DiseaseOrPhenotypicFeature I-DiseaseOrPhenotypicFeature O O O O