Antitumor Effects of a Soluble Insulin-Like Growth Factor I Receptor in Human Ovarian Cancer Cells: Advantage of Recombinant Protein Administration in Vivo

Atsushi Hongo, Hiroyuki Kuramoto, Yojiro Nakamura, Kosei Hasegawa, Keiichiro Nakamura, Junichi Kodama, Yuji Hiramatsu

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Antitumor effects of a soluble form dominant negative of the type I insulin-like growth factor receptor (IGF-IR) designated as 486/STOP were evaluated in CaOV-3 human ovarian cancer cells by establishing stable transformants overexpressing 486/STOP and by administration of 486/STOP recombinant protein. Expression of 486/STOP was detected from total cell lysates, as well as conditioned media collected from stable transformants. In stable transformants, growth in monolayer was slightly retarded, and anchorage-independent growth in vitro and tumorigenicity in vivo were markedly inhibited. Addition of conditioned media from 486/STOP cells inhibited anchorage-independent growth of parental cells. Although tumorigenicity of parental cells in vivo was abrogated when they were cocultured in monolayer with 486/STOP cells over 48 h before injection to nude mice, coinjection of parental cells and 486/STOP cells without preculture was not successful. In contrast, administration of 486/STOP partially purified recombinant protein inhibited tumorigenicity of parental cells in vivo. Because 486/STOP cells result in massive apoptosis in vivo within 48 h, usage of a recombinant protein has a great advantage to use its unique bystander effect in vivo for clinical application.

Original languageEnglish
Pages (from-to)7834-7839
Number of pages6
JournalCancer Research
Issue number22
Publication statusPublished - Nov 15 2003


ASJC Scopus subject areas

  • Cancer Research
  • Oncology

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