The insulin-like growth factors (IGFs) and IGF binding proteins in postnatal development of murine mammary glands

J Mammary Gland Biol Neoplasia. 2000 Jan;5(1):31-42. doi: 10.1023/a:1009511131541.


The insulin-like growth factors are mitogens and survival factors for normal mammary epithelial cells in vitro. Data reviewed here demonstrate that mRNAs for IGF-I and IGF-II, the IGF type I receptor and the IGFBPs are expressed locally in mammary tissue during pubertal and pregnancy-induced growth and differentiation of murine mammary glands. IGF-I, IGF-II and the IGF-IR were expressed in terminal end buds (TEBs) in virgin glands during ductal growth. In addition, IGF-II and IGF-IR mRNAs were expressed in ductal and alveolar epithelium in glands throughout postnatal development. Consistent with these results, IGF-I promoted ductal growth and proliferation in mouse mammary glands in organ culture. In addition to endogenous expression of the IGFs and IGF-IR, the IGFBPs showed a varied pattern of expression in mammary tissue during postnatal development. For example, IGFBP-3 and -5 mRNAs were expressed in TEBs and ducts while IGFBP-2 and -4 mRNAs were expressed in stromal cells immediately surrounding the epithelium. These results support a role for the IGFs and IGFBPs as local mediators of postnatal mammary gland growth and differentiation.

Publication types

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

MeSH terms

  • Animals
  • Female
  • Gene Expression Regulation, Developmental*
  • Insulin-Like Growth Factor Binding Proteins / genetics*
  • Insulin-Like Growth Factor I / genetics*
  • Insulin-Like Growth Factor II / genetics*
  • Mammary Glands, Animal / cytology
  • Mammary Glands, Animal / growth & development
  • Mammary Glands, Animal / physiology*
  • Mice
  • Pregnancy
  • Sexual Maturation


  • Insulin-Like Growth Factor Binding Proteins
  • Insulin-Like Growth Factor I
  • Insulin-Like Growth Factor II