title: Targeting cancer cells by novel engineered modular transporters.
abstract: A major problem in the treatment of cancer is the specific targeting of drugs to these abnormal cells. Ideally, such a drug should act over short distances to minimize damage to healthy cells and target subcellular compartments that have the highest sensitivity to the drug. We describe the novel approach of using modular recombinant transporters to target photosensitizers to the nucleus, where their action is most pronounced, of cancer cells overexpressing ErbB1 receptors. We have produced a new generation of the transporters consisting of (a) epidermal growth factor as the internalizable ligand module to ErbB1 receptors, (b) the optimized nuclear localization sequence of SV40 large T-antigen, (c) a translocation domain of diphtheria toxin as an endosomolytic module, and (d) the Escherichia coli hemoglobin-like protein HMP as a carrier module. The modules retained their functions within the transporter chimera: they showed high-affinity interactions with ErbB1 receptors and alpha/beta-importin dimers and formed holes in lipid bilayers at endosomal pH. A photosensitizer conjugated with the transporter produced singlet oxygen and (*)OH radicals similar to the free photosensitizer. Photosensitizers-transporter conjugates have >3,000 times greater efficacy than free photosensitizers for target cells and were not photocytotoxic at these concentrations for cells expressing a few ErbB1 receptors per cell, in contrast to free photosensitizers. The different modules of the transporters, which are highly expressed and easily purified to retain full activity of each of the modules, are interchangeable, meaning that they can be tailored for particular applications.
authors.affiliation: Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Dinara G
authors.initials: DG
authors.lastname: Gilyazova
authors.forename: Andrey A
authors.initials: AA
authors.lastname: Rosenkranz
authors.forename: Pavel V
authors.initials: PV
authors.lastname: Gulak
authors.forename: Vladimir G
authors.initials: VG
authors.lastname: Lunin
authors.forename: Olga V
authors.initials: OV
authors.lastname: Sergienko
authors.forename: Yuri V
authors.initials: YV
authors.lastname: Khramtsov
authors.forename: Kirill N
authors.initials: KN
authors.lastname: Timofeyev
authors.forename: Mikhail A
authors.initials: MA
authors.lastname: Grin
authors.forename: Andrey F
authors.initials: AF
authors.lastname: Mironov
authors.forename: Andrey B
authors.initials: AB
authors.lastname: Rubin
authors.forename: Georgii P
authors.initials: GP
authors.lastname: Georgiev
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Sobolev
mesh_terms: D021581:Active Transport, Cell Nucleus; D000818:Animals; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism*; D004093:Dihydropteridine Reductase / Q000008:administration & dosage*; D004167:Diphtheria Toxin / Q000008:administration & dosage*; D004815:Epidermal Growth Factor / Q000008:administration & dosage*; D066246:ErbB Receptors / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000008:administration & dosage*; D006420:Hemeproteins / Q000008:administration & dosage*; D006801:Humans; D051379:Mice; D009247:NADH, NADPH Oxidoreductases / Q000008:administration & dosage*; D041681:NIH 3T3 Cells; D019913:Nuclear Localization Signals; D017319:Photosensitizing Agents / Q000008:administration & dosage*; D017382:Reactive Oxygen Species; D011994:Recombinant Proteins / Q000008:administration & dosage
chemical_list: D004167:Diphtheria Toxin; D029968:Escherichia coli Proteins; D006420:Hemeproteins; D019913:Nuclear Localization Signals; D017319:Photosensitizing Agents; D017382:Reactive Oxygen Species; D011994:Recombinant Proteins; D004815:Epidermal Growth Factor; D004093:Dihydropteridine Reductase; C076538:hmp protein, E coli; D009247:NADH, NADPH Oxidoreductases; D066246:ErbB Receptors