Recombinant human interferon alpha increases oestrogen receptor expression in human breast cancer cells (ZR-75-1) and sensitizes them to the anti-proliferative effects of tamoxifen

Br J Cancer. 1987 Mar;55(3):255-7. doi: 10.1038/bjc.1987.49.


Exposure of ZR-75-1 human breast cancer cells for 48 h to human recombinant interferon alpha (IFN alpha) resulted in increased expression of oestrogen receptors as measured in a whole cell binding assay. This effect was inversely proportional to dose being significant following treatment with 10-100 IU IFN ml-1 and was only observed at a low initial cell plating density. The extent of the increase in oestrogen receptor levels ranged from 1.2- to 7.2-fold following treatment with 10 IU IFN ml-1. No increase in progesterone receptor expression was observed under the same experimental conditions. Concentrations of IFN which increased oestrogen receptor levels had no effect on cell proliferation. IFN (500 IU ml-1) inhibited cell proliferation and the combination of this treatment with tamoxifen (2 microM) had a greater anti-proliferative effect than either drug alone although there was no evidence of synergism. However, a 5-day pretreatment of cells with IFN (10 IU ml-1) markedly sensitised them to the growth-inhibiting effect of a subsequent 6-day exposure to tamoxifen.

MeSH terms

  • Binding, Competitive
  • Breast Neoplasms / drug therapy*
  • Breast Neoplasms / metabolism
  • Cell Count
  • Cell Division / drug effects
  • Cell Line
  • Dose-Response Relationship, Drug
  • Humans
  • Interferon Type I / pharmacology*
  • Receptors, Estrogen / metabolism*
  • Receptors, Progesterone / metabolism
  • Recombinant Proteins / pharmacology
  • Tamoxifen / pharmacology*


  • Interferon Type I
  • Receptors, Estrogen
  • Receptors, Progesterone
  • Recombinant Proteins
  • Tamoxifen