title: Immunogenicity and toxicity of transferrin receptor-targeted hybrid peptide as a potent anticancer agent.
abstract: OBJECTIVE
  Transferrin receptor (TfR) is a cell membrane-associated glycoprotein involved in the cellular uptake of iron and the regulation of cell growth. Recent studies have shown elevated expression levels of TfR on cancer cells compared with normal cells. We previously designed a TfR-lytic hybrid peptide, which combines the TfR-binding peptide and a lytic peptide, and reported that it bound specifically to TfR and selectively killed cancer cells. Furthermore, the intravenous administration of TfR-lytic peptide in an athymic mouse model significantly inhibited tumor progression. To evaluate the immunogenicity of this peptide as a novel and potent anticancer agent, we investigated whether TfR-lytic hybrid peptide elicits cellular and humoral immune responses to produce antibodies. We also examined the toxicity of this peptide in syngeneic mice.
  
  
  METHODS
  We performed hematologic and blood chemistry test and histological analysis and assessed hemolytic activity to check toxicity. To evaluate the immunogenicity, measurement of murine interferon-gamma and detection of TfR-lytic-specific antibody by ELISA were demonstrated.
  
  
  RESULTS
  No T cell immune response or antibodies were detected in the group treated with TfR-lytic hybrid peptide. No hematologic toxicity, except for a decrease in leukocytes, was observed, and no remarkable influence on metabolic parameters and organs (liver, kidney, and spleen) was noted.
  
  
  CONCLUSIONS
  Therefore, TfR-lytic hybrid peptide might provide an alternative therapeutic option for patients with cancer.
authors: Department of Pharmacoepidemiology, Graduate School of Medicine and Public Health, Kyoto University, Yoshidakonoe-cho, Sakyo-ku, Kyoto 606-8501, Japan.
authors: Megumi
authors: M
authors: Kawamoto
authors: Masayuki
authors: M
authors: Kohno
authors: Tomohisa
authors: T
authors: Horibe
authors: Koji
authors: K
authors: Kawakami
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000970:Antineoplastic Agents / Q000276:immunology / Q000494:pharmacology*; D045744:Cell Line, Tumor; D004912:Erythrocytes / Q000187:drug effects; D005260:Female; D005434:Flow Cytometry; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D007111:Immunity, Cellular / Q000187:drug effects; D056724:Immunity, Humoral / Q000187:drug effects; D007371:Interferon-gamma / Q000494:pharmacology; D008198:Lymph Nodes / Q000166:cytology / Q000187:drug effects; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009368:Neoplasm Transplantation; D010455:Peptides / Q000276:immunology / Q000494:pharmacology*; D011990:Receptors, Transferrin / Q000187:drug effects*; D014185:Transplantation, Isogeneic
chemical_list: D000970:Antineoplastic Agents; D010455:Peptides; D011990:Receptors, Transferrin; D007371:Interferon-gamma