Recognition of activated CSF-1 receptor in breast carcinomas by a tyrosine 723 phosphospecific antibody

Oncogene. 1997 May 29;14(21):2553-61. doi: 10.1038/sj.onc.1201092.

Abstract

The macrophage colony stimulating factor receptor (CSF-1R), the product of the c-fms proto-oncogene, plays an important role in regulating the normal proliferation and differentiation of macrophages and trophoblasts. However, the abnormal expression of CSF-1R transcripts and protein by human breast carcinomas has been shown to correlate with advanced stage and poor prognosis. Ligand activated CSF-1R dimers transphosphorylate several tyrosines in their cytoplasmic domains which provide recognition sites for various effector proteins in multiple signal transduction pathways. In cells transformed by the c-fms oncogene, one of the major CSF-1R phosphotyrosines, pTyr723 is important for phenotypic expression of anchorage-independent growth and metastasis. In order to investigate the relationship between receptor activation/phosphorylation and cellular phenotypes in vitro and in vivo, we prepared a CSF-1R phosphorylation-state specific antibody raised against a specific phosphopeptide of CSF-1R, which included phosphorylated tyrosine 723. On immunoblots of lysates from cells expressing CSF-1R, this antibody recognizes phosphorylated CSF-IR in CSF-1 stimulated cells but not in unstimulated cells. As an immunohistochemical reagent, this antibody stained 52% of invasive human breast tumors (72% of CSF-1R positive cases) in a sample of 114 cases and 38% of carcinoma in situ. This data represents the first direct evidence of in vivo phosphorylation of CSF-1R in human breast carcinomas.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antibodies / chemistry*
  • Antibody Specificity
  • Breast Neoplasms / diagnosis
  • Breast Neoplasms / metabolism*
  • Carcinoma in Situ / metabolism
  • Cells, Cultured
  • Cross Reactions
  • Epitopes
  • Fibroblasts / metabolism
  • Genes, fms / physiology
  • Humans
  • Immunohistochemistry
  • Macrophages / metabolism
  • Mice
  • Mice, Inbred BALB C
  • Phosphopeptides / immunology*
  • Phosphorylation
  • Phosphotyrosine / immunology*
  • Receptor, Macrophage Colony-Stimulating Factor / immunology*
  • Receptor, Macrophage Colony-Stimulating Factor / metabolism
  • Tumor Cells, Cultured

Substances

  • Antibodies
  • Epitopes
  • Phosphopeptides
  • Phosphotyrosine
  • Receptor, Macrophage Colony-Stimulating Factor