title: The membrane-lytic peptides K8L9 and melittin enter cancer cells via receptor endocytosis following subcytotoxic exposure.
abstract: We investigate the cell entry mechanism of the membrane-lytic peptides K8L9 and melittin in cancer cell lines. K8L9 and melittin interacted with the highly expressed endocytic receptors neuropilin-1, low-density lipoprotein-related protein receptor 1 (LRP1), and transferrin receptor. Silencing of these receptors by small interfering RNAs (siRNAs) attenuated the cytotoxic activity of K8L9 in four cancer cell lines. Intracellular K8L9 and melittin triggered enlargement of the lysosomal compartments and cytosolic translocation of cathepsin B. Hsc70 was identified as a melittin-interactive molecule using coimmunoprecipitation and mass spectrometry, and Hsc70-siRNA attenuated the cellular uptake of K8L9 and cytotoxic activity by K8L9 and melittin. These findings suggest that K8L9 and melittin can enter cancer cells via receptor endocytosis following subcytotoxic treatment and subsequently affect lysosomal compartments.
authors.affiliation: Department of Pharmacoepidemiology, Graduate School of Medicine and Public Health, Kyoto University, Yoshida Konoecho, Sakyo-ku, Kyoto, 606-8501, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kohno
authors.affiliation: Department of Pharmacoepidemiology, Graduate School of Medicine and Public Health, Kyoto University, Yoshida Konoecho, Sakyo-ku, Kyoto, 606-8501, Japan.
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Horibe
authors.affiliation: Department of Pharmacoepidemiology, Graduate School of Medicine and Public Health, Kyoto University, Yoshida Konoecho, Sakyo-ku, Kyoto, 606-8501, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Ohara
authors.affiliation: Medical Research Support Center, Graduate School of Medicine, Kyoto University, Yoshida Konoecho, Sakyo-ku, Kyoto, 606-8501, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Ito
authors.affiliation: Department of Pharmacoepidemiology, Graduate School of Medicine and Public Health, Kyoto University, Yoshida Konoecho, Sakyo-ku, Kyoto, 606-8501, Japan. Electronic address: kawakami.koji.4e@kyoto-u.ac.jp.
authors.forename: Koji
authors.initials: K
authors.lastname: Kawakami
mesh_terms: D000595:Amino Acid Sequence; D002401:Cathepsin B / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004705:Endocytosis / Q000187:drug effects*; D050883:HSC70 Heat-Shock Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D006801:Humans; D047468:Immunoprecipitation; D026503:Low Density Lipoprotein Receptor-Related Protein-1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D008247:Lysosomes / Q000187:drug effects / Q000378:metabolism; D008555:Melitten / Q000737:chemistry / Q000633:toxicity*; D008969:Molecular Sequence Data; D039942:Neuropilin-1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry / Q000633:toxicity*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D011990:Receptors, Transferrin / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
chemical_list: D050883:HSC70 Heat-Shock Proteins; C475476:LRP1 protein, human; D026503:Low Density Lipoprotein Receptor-Related Protein-1; D010455:Peptides; D034741:RNA, Small Interfering; D011990:Receptors, Transferrin; D039942:Neuropilin-1; D008555:Melitten; D002401:Cathepsin B