Expression of constitutively active Akt-3 in MCF-7 breast cancer cells reverses the estrogen and tamoxifen responsivity of these cells in vivo.

Abstract

These results indicate that expression of active Akt-3 in MCF-7 cells results in E2-independent tumor growth. Moreover, the growth of these tumors is inhibited by E2 and enhanced by tamoxifen. Finally, these tumors are resistant to ICI 182,780. These findings suggest that the amount of active Akt present in breast cancers may be important in the relative efficacy of different treatments.