title: Antigen-responsive molecular sensor enables real-time tumor-specific imaging.
abstract: Antibody-fluorophore conjugates have high potential for the specific fluorescence detection of target cancer cellsin vitroandin vivo. However, the antibody-fluorophore conjugates described to date are inappropriate for real-time imaging of target cells because removal of unbound antibody is required to reduce background fluorescence before quantifiable analysis by microscopy. In addition, clinical applications of the conjugates have been limited by persistent background retention due to their long systemic circulation and nonspecific uptake. Here we report fast and real-time near-infrared fluorescence imaging of target cancer cells using an antigen-responsive molecular "on-off" sensor: the fluorescence of trastuzumab-ATTO680 conjugate is dark (i.e., turned off) in the extracellular region, while it becomes highly fluorescent (i.e., turned on) upon binding to the target antigen HER2 on cancer cell surface. This molecular switch enables fast and real-time imaging of target cancer cellsin vitroandin vivo.
authors.affiliation: Molecular Imaging and Therapy Branch, National Cancer Center, 323 Ilsan-ro, Goyang, Gyeonggi 10408, Republic of Korea.
authors.forename: Hyunjin
authors.initials: H
authors.lastname: Kim
authors.affiliation: Gordon Center for Medical Imaging, Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
authors.forename: Hak Soo
authors.initials: HS
authors.lastname: Choi
authors.affiliation: Molecular Imaging and Therapy Branch, National Cancer Center, 323 Ilsan-ro, Goyang, Gyeonggi 10408, Republic of Korea.
authors.forename: Seok-Ki
authors.initials: SK
authors.lastname: Kim
authors.affiliation: Biomolecular Function Research Branch, National Cancer Center, 323 Ilsan-ro, Goyang, Gyeonggi 10408, Republic of Korea.
authors.forename: Byung Il
authors.initials: BI
authors.lastname: Lee
authors.affiliation: Molecular Imaging and Therapy Branch, National Cancer Center, 323 Ilsan-ro, Goyang, Gyeonggi 10408, Republic of Korea.
authors.forename: Yongdoo
authors.initials: Y
authors.lastname: Choi
mesh_terms: D000951:Antigens, Neoplasm / Q000032:analysis*; D045744:Cell Line, Tumor; D006801:Humans; D007259:Infrared Rays; D009369:Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D061848:Optical Imaging / Q000379:methods*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis*; D000068878:Trastuzumab / Q000378:metabolism
chemical_list: D000951:Antigens, Neoplasm; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab; C508053:ERBB2 protein, human
keywords: Antigen-responsive; near-infrared fluorescence imaging; real-time imaging.