The insulin-like growth factor binding protein BP-25 is expressed by human breast cancer cells Academic Article Article uri icon


MeSH Major

  • Emergency Service, Hospital
  • National Health Programs


  • Specific binding proteins are thought to modulate the effects of IGF-I. Previous work has demonstrated that media conditioned by human breast cancer cells contains IGF-I binding activity. Radiolabelled IGF-I incubated with serum-free conditioned media from the breast cancer cell line MDA-MB 231 eluted with an apparent M.W. of 35-40 kDa when analyzed by gel filtration chromatography at pH 7.4. The M.W. of this binding activity corresponded to that of BP-25, a binding protein cloned from the hepatocellular carcinoma cell line HepG2. Two breast cancer cell lines, MDA-MB 231 and Hs578T, were found to express BP-25 RNA. Specific BP-25 radioimmunoassay detected BP-25 production in the conditioned media of these two cell lines. Immunoprecipitation confirmed that metabolically labelled MDA-MB 231 released 30 kDa BP-25 into its medium. This study demonstrates that some breast cancer cells express the IGF-I binding protein, BP-25.

publication date

  • January 16, 1989



  • Academic Article


Digital Object Identifier (DOI)

  • 10.1016/S0006-291X(89)80173-1

PubMed ID

  • 2463838

Additional Document Info

start page

  • 38

end page

  • 44


  • 158


  • 1