Sequential alpha-interferon and tamoxifen: In vitro biologic effects of two growth modulators

Tamoxifen and alpha-interferon have interesting and complementary biologic effects which may be relevant for breast cancer growth and regression. The hormone responsive cell line MCF-7 was used as a model to study the biologic effects of sequential administration of these two agents. Interferon had a significant antiproliferative effect and increased ER and TGF-beta expression. The combination had at least additive antiproliferative effects as well as effects on expression of ER, TGF-beta, c-erbB-2, P24 and Ki67. alpha-IFN modulates TMX induced biologic effects and the sequential administration of alpha-IFN and TMX may lead to potentially important modulation of biologic endpoints. Further studies are appropriate.