title: Efficacy of doxorubicin-transferrin conjugate in apoptosis induction in human leukemia cells through reactive oxygen species generation.
abstract: BACKGROUND
  Doxorubicin (DOX) is a small molecular cytotoxic agent that can be transferred efficiently to cancer cells by nanocarriers. This anthracycline antibiotic serves as an effective anti-neoplastic drug against both hematological and solid malignancies. Here, we set out to assess the capacity of a novel doxorubicin - transferrin conjugate (DOX-TRF) to provoke apoptosis in human normal and leukemia cells through free radicals produced via a redox cycle of doxorubicin (DOX) when released from its conjugate.
  
  
  METHODS
  After DOX-TRF exposure, we determined the time-course of apoptotic and necrotic events, the generation of reactive oxygen species (ROS), changes in mitochondrial membrane potential, as well as alterations in cytochrome c levels and intracellular calcium concentrations in human leukemia-derived cell lines (CCRF-CEM, K562 and its doxorubicin-resistant derivative K562/DOX) and normal peripheral blood-derived mononuclear cells (PBMC).
  
  
  RESULTS
  We found that DOX-TRF can induce apoptosis in all leukemia-derived cell lines tested, which was associated with morphological changes and decreases in mitochondrial membrane potential. In comparison to free DOX treated cells, we observed a time-dependency between a higher level of ROS generation and a higher drop in mitochondrial membrane potential, particularly in the doxorubicin-resistant cell line. In addition, we found that the apoptotic cell death induced by DOX-TRF was directly associated with a release of cytochrome c from the mitochondria and an increase in intracellular calcium level in all human leukemia-derived cell lines tested.
  
  
  CONCLUSIONS
  Our data indicate that DOX-TRF is considerably more cytotoxic to human leukemia cells than free DOX. In addition, we show that DOX-TRF can effectively produce free radicals, which are directly involved in apoptosis induction.
authors.affiliation: Department of Thermobiology, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143 Street, 90-236, Lodz, Poland. szwedmesia@tlen.pl.
authors.forename: Marzena
authors.initials: M
authors.lastname: Szwed
authors.affiliation: INSERM U916, Institut Bergonié, Université de Bordeaux, 33076, Bordeaux, France.
authors.forename: Audrey
authors.initials: A
authors.lastname: Laroche-Clary
authors.affiliation: INSERM U916, Institut Bergonié, Université de Bordeaux, 33076, Bordeaux, France.
authors.forename: Jacques
authors.initials: J
authors.lastname: Robert
authors.affiliation: Department of Thermobiology, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143 Street, 90-236, Lodz, Poland.
authors.forename: Zofia
authors.initials: Z
authors.lastname: Jozwiak
mesh_terms: D000328:Adult; D017209:Apoptosis / Q000187:drug effects*; D002118:Calcium / Q000378:metabolism; D048430:Cell Shape / Q000187:drug effects; D045304:Cytochromes c / Q000378:metabolism; D004317:Doxorubicin / Q000494:pharmacology*; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D020014:K562 Cells; D007938:Leukemia / Q000378:metabolism* / Q000473:pathology*; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000378:metabolism; D008297:Male; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D014168:Transferrin / Q000494:pharmacology*; D055815:Young Adult
chemical_list: D017382:Reactive Oxygen Species; D014168:Transferrin; C000599870:doxorubicin-transferrin conjugate; D004317:Doxorubicin; D045304:Cytochromes c; D002118:Calcium
keywords: Anticancer therapy; Doxorubicin-transferrin conjugate; Leukemia cells; Mitochondrial membrane potential; ROS generation