title: Chemokine-derived peptides as carriers for gene delivery to CXCR4 expressing cells.
abstract: BACKGROUND
  Cell and tissue-specific DNA delivery can be achieved by derivatizing vehicles with a targeting ligand for certain receptor. CXCR4 is a receptor of chemokine stromal cell-derived factor (SDF)-1 and viral protein viral macrophage inflammatory protein (vMIP)-II. It is expressed on some types of stem and cancer cells. The present study aimed to design and characterize the group of CXCR4 targeted peptides for receptor-mediated gene delivery. We focused on bifunctional peptide carriers: two derived from N-terminal sequences of SDF-1 and one from vMIP-II.
  
  
  METHODS
  Three synthetic chemokine-derived peptides, designated long CDP (KPVSLSYRSPSRFFESH-K9-biotin), short CDP (KPVSLSYR-K9-biotin) and viral CDP (D-LGASWHRPDK-K9-biotin), were evaluated for gene delivery to CXCR4 positive and negative cells. Oligolysine K9-biotin was used as a control. The Lys 8 moiety binds DNA electrostatically, whereas C-terminal lysine was modified with biotin to study intracellular uptake of the peptides. Complex formation with DNA was monitored by ethidium bromide fluorescence quenching.
  
  
  RESULTS
  All peptides condensed plasmid DNA. Gene delivery by CDP/DNA complexes is glycerol-dependent and the level of luciferase expression with signal modified carriers was comparable with the efficacy of polyethylenimine (PEI) in CXCR4 expressing cell lines (A172, HeLa) and was ten- to 50-fold higher compared to unmodified peptide. By contrast, CDP transfection efficacy on CXCR4-negative cells (chinese hamster ovary) was much lower than in PEI. Intracellular uptake analysis of biotin-labeled peptides indicated that CDPs entered cells more efficiently than oligolysine.
  
  
  CONCLUSIONS
  The small, bifunctional peptides reported in the present study may be useful in gene delivery to (and gene therapy of) the different tumors and other cells expressing CXCR4.
authors: Centre for Drug Research, Faculty of Pharmacy, University of Helsinki, Finland.
authors: Anna
authors: A
authors: Egorova
authors: Anton
authors: A
authors: Kiselev
authors: Marika
authors: M
authors: Hakli
authors: Marika
authors: M
authors: Ruponen
authors: Vladislav
authors: V
authors: Baranov
authors: Arto
authors: A
authors: Urtti
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D016466:CHO Cells; D018925:Chemokines / Q000737:chemistry / Q000235:genetics*; D006224:Cricetinae; D003412:Cricetulus; D005434:Flow Cytometry; D005822:Genetic Vectors; D006801:Humans; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry* / Q000276:immunology; D010957:Plasmids; D019718:Receptors, CXCR4 / Q000235:genetics* / Q000276:immunology; D014162:Transfection
chemical_list: D000911:Antibodies, Monoclonal; C527276:CXCR4 protein, human; D018925:Chemokines; D010455:Peptides; D019718:Receptors, CXCR4