Insulin-like growth factor-II overexpression in MCF-7 cells induces phenotypic changes associated with malignant progression Academic Article uri icon


MeSH Major

  • Cell Transformation, Neoplastic
  • Insulin-Like Growth Factor II
  • RNA, Messenger


  • It has been proposed that the insulin-like growth factors (IGFs) can act as autocrine and/or paracrine growth promoters in breast cancer. To investigate this hypothesis, we infected early passage MCF-7 cells with a retroviral vector containing the coding sequence for the IGF-II preprohormone along with a constitutive cytomegalovirus promoter sequence. These cells do not normally express IGF-I or IGF-II. After infection with the retroviral vector, several single cell clones were analyzed. Seven of nine isolated clones expressed very high levels of IGF-II mRNA. Biologically active IGF-II protein was easily detectable in the medium conditioned by the IGF-II-expressing clones, and IGF receptors were down-regulated in these. All IGF-II-expressing clones showed marked morphological changes in anchorage-dependent culture, growing in large clumps and as free-floating colonies. The cells also cloned in soft agar in the absence of estrogen, while the wild-type MCF-7 cells and control cells infected with an irrelevant DNA sequence showed none of these properties. alpha IR-3, an antibody that blocks the type I IGF receptor, inhibited the growth of IGF-II-expressing clones in serum-free medium. This model demonstrates that IGF-II can serve as an autocrine growth stimulant in breast cancer epithelial cells and that IGF-II overexpression may be capable of mediating malignant progression in human breast cancer.

publication date

  • January 1992



  • Academic Article



  • eng

Digital Object Identifier (DOI)

  • 10.1210/mend.6.1.1310798

PubMed ID

  • 1310798

Additional Document Info

start page

  • 91

end page

  • 100


  • 6


  • 1