title: Near-infrared photoimmunotherapy with galactosyl serum albumin in a model of diffuse peritoneal disseminated ovarian cancer.
abstract: Near-infrared photoimmunotherapy (NIR-PIT) is a highly cell-selective cancer therapy based on an armed antibody conjugated with a phthalocyanine-based photo-absorber, IRDye700DX (IR700). NIR-PIT can quickly kill target cells that express specific proteins on the cellular membrane but only when the antibody-IR700 conjugate binds to the cell membrane and is then exposed to NIR light. NIR-PIT is highly selective based on the specificity of the antibody. Galactosyl serum albumin (GSA) is composed of albumin decorated with galactose molecules conjugated to the carboxyl groups of albumin. GSA binds to beta-D-galactose receptors, a surface lectin, which are overexpressed on the cell surface of many cancers, including ovarian cancers and is quickly internalized after binding. Here, we demonstrate the feasibility of NIR-PIT in a model of disseminated peritoneal ovarian cancer (SHIN3 cells) using GSA-IR700 that binds to beta-D-galactose receptors. GSA-IR700 bound quickly to SHIN3 cells, then accumulated in the endo-lysosomes. Cell-specific killing was observed in vitro, yet a relatively large dose of NIR light exposure was required for cell killing compared to antibody-IR700 conjugates. To evaluate in vivo therapeutic effects of GSA-IR700 NIR-PIT, peritoneal disseminated SHIN3 tumor-bearing mice were separated into four groups: no treatment; NIR light only; GSA-IR700 only; and GSA-IR700 NIR-PIT. Repeated NIR-PIT showed significant suppression of tumor based on bioluminescence compared to the other groups (p < 0.05). Thus, repeated NIR-PIT using GSA-IR700 can achieve efficient antitumor effects, although GSA-IR700 NIR-PIT was less effective than antibody-IR700 NIR-PIT conjugates likely due to the rapid internalization of GSA-IR700.
authors.affiliation: Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, 20892, USA.
authors.forename: Toshiko
authors.initials: T
authors.lastname: Harada
authors.affiliation: Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, 20892, USA.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Nakamura
authors.affiliation: Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, 20892, USA.
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Sato
authors.affiliation: Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, 20892, USA.
authors.forename: Tadanobu
authors.initials: T
authors.lastname: Nagaya
authors.affiliation: Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, 20892, USA.
authors.forename: Shuhei
authors.initials: S
authors.lastname: Okuyama
authors.affiliation: Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, 20892, USA.
authors.forename: Fusa
authors.initials: F
authors.lastname: Ogata
authors.affiliation: Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, 20892, USA.
authors.forename: Peter L
authors.initials: PL
authors.lastname: Choyke
authors.affiliation: Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, 20892, USA.
authors.forename: Hisataka
authors.initials: H
authors.lastname: Kobayashi
mesh_terms: D000418:Albumins / Q000008:administration & dosage* / Q000737:chemistry / Q000494:pharmacology; D000818:Animals; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D005260:Female; D005690:Galactose / Q000737:chemistry*; D006801:Humans; D018796:Immunoconjugates / Q000008:administration & dosage* / Q000627:therapeutic use; D007167:Immunotherapy; D007259:Infrared Rays; D051379:Mice; D010051:Ovarian Neoplasms / Q000628:therapy*; D010534:Peritoneal Neoplasms / Q000628:therapy*; D017319:Photosensitizing Agents / Q000737:chemistry*; D010789:Phototherapy; D023041:Xenograft Model Antitumor Assays
chemical_list: D000418:Albumins; D018796:Immunoconjugates; D017319:Photosensitizing Agents; D005690:Galactose
keywords: beta-D-galactose receptor; galactosyl serum albumin; near-infrared photoimmunotherapy; ovarian cancer; peritoneal cancer metastases