title: Improved cytosolic translocation and tumor-killing activity of Tat-shepherdin conjugates mediated by co-treatment with Tat-fused endosome-disruptive HA2 peptide.
abstract: Tat peptides are useful carriers for delivering biologic molecules into the cell for both functional analysis of intracellular disease-related proteins and treatment of refractory diseases. Most internalized Tat-fused cargos (Tat-cargos) are trapped within the endosome, however, which limits the biologic function of the cargo. In this study, we demonstrated that Tat-fused HA2 peptide (HA2Tat), an endosome disrupted peptide, enhanced the endosome-escape efficiency of Tat-cargos. In cells treated with a mixture of fluorescein isothiocyanate-labeled Tat and HA2Tat, widespread fluorescence was observed throughout the cytosol. In addition, this HA2Tat-mediated cytosolic delivery technique led to enhanced cytotoxicity of Tat-fused anti-cancer peptides, specifically shepherdin. Thus, we improved the function of the delivered molecules by co-treating with HA2Tat and propose that this is a useful method for the delivery of therapeutic macromolecules into the cytosol.
authors.affiliation: Laboratory of Pharmaceutical Proteomics, National Institute of Biomedical Innovation, 7-6-8 Saito-Asagi, Ibaraki, Osaka 567-0085, Japan.
authors.forename: Toshiki
authors.initials: T
authors.lastname: Sugita
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Yoshikawa
authors.forename: Yohei
authors.initials: Y
authors.lastname: Mukai
authors.forename: Natsue
authors.initials: N
authors.lastname: Yamanada
authors.forename: Sunao
authors.initials: S
authors.lastname: Imai
authors.forename: Kazuya
authors.initials: K
authors.lastname: Nagano
authors.forename: Yasunobu
authors.initials: Y
authors.lastname: Yoshida
authors.forename: Hiroko
authors.initials: H
authors.lastname: Shibata
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Yoshioka
authors.forename: Shinsaku
authors.initials: S
authors.lastname: Nakagawa
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Kamada
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Tsunoda
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Tsutsumi
mesh_terms: D045744:Cell Line, Tumor; D002470:Cell Survival; D003600:Cytosol / Q000378:metabolism*; D011992:Endosomes / Q000378:metabolism*; D016650:Fluorescein-5-isothiocyanate; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D009369:Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism*; D010455:Peptides / Q000235:genetics / Q000378:metabolism*; D021381:Protein Transport; D054322:tat Gene Products, Human Immunodeficiency Virus / Q000235:genetics / Q000378:metabolism*
chemical_list: D010446:Peptide Fragments; D010455:Peptides; C503112:shepherdin; D054322:tat Gene Products, Human Immunodeficiency Virus; D016650:Fluorescein-5-isothiocyanate