title: Tumor delivery of antisense oligomer using trastuzumab within a streptavidin nanoparticle.
abstract: OBJECTIVE
  Trastuzumab (Herceptin™) is often internalized following binding to Her2+ tumor cells. The objective of this study was to investigate whether trastuzumab can be used as a specific carrier to deliver antisense oligomers into Her2+ tumor cells both in vitro and in vivo.
  
  
  METHODS
  A biotinylated MORF oligomer antisense to RhoC mRNA and its biotinylated sense control were labeled with either lissamine for fluorescence detection or 99mTc for radioactivity detection and were linked to biotinylated trastuzumab via streptavidin. The nanoparticles were studied in SUM190 (RhoC+, Her2+) study and SUM149 (RhoC+, Her2−) control cells in culture and as xenografts in mice.
  
  
  RESULTS
  As evidence of unimpaired Her2+ binding of trastuzumab within the nanoparticle, accumulations were clearly higher in SUM190 compared to SUM149 cells and, by whole-body imaging, targeting of SUM190 tumor was similar to that expected for a radiolabeled trastuzumab. As evidence of internalization, fluorescence microscopy images of cells grown in culture and obtained from xenografts showed uniform cytoplasm distribution of the lissamine-MORF. An invasion assay showed decreased RhoC expression in SUM190 cells when incubated with the antisense MORF nanoparticles at only 100 nM.
  
  
  CONCLUSIONS
  Both in cell culture and in animals, the nanoparticle with trastuzumab as specific carrier greatly improved tumor delivery of the antisense oligomer against RhoC mRNA into tumor cells overexpressing Her2 and may be of general utility.
authors: Division of Nuclear Medicine, Department of Radiology, University of Massachusetts Medical School, Worcester, MA 01655, USA. Yi.Wang@Yale.edu
authors: Yi
authors: Y
authors: Wang
authors: Xinrong
authors: X
authors: Liu
authors: Ling
authors: L
authors: Chen
authors: Dengfeng
authors: D
authors: Cheng
authors: Mary
authors: M
authors: Rusckowski
authors: Donald J
authors: DJ
authors: Hnatowich
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry* / Q000378:metabolism; D061067:Antibodies, Monoclonal, Humanized; D001692:Biological Transport; D001710:Biotin / Q000378:metabolism; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic; D004337:Drug Carriers / Q000737:chemistry* / Q000378:metabolism; D005260:Female; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D051379:Mice; D009025:Morpholines / Q000378:metabolism*; D060172:Morpholinos; D053758:Nanoparticles / Q000737:chemistry*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D019809:Streptavidin / Q000737:chemistry* / Q000378:metabolism; D000068878:Trastuzumab
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D001710:Biotin; D004337:Drug Carriers; D009025:Morpholines; D060172:Morpholinos; D018719:Erb-b2 Receptor Tyrosine Kinases; D019809:Streptavidin; D000068878:Trastuzumab