Fig. 7. Schematic representation of the effect of tamoxifen on miR-451 and 14-3-3ζ regulation and their impact on breast cancer cell phenotypic properties leading to tamoxifen resistance.

Tamoxifen down-regulates miR-451, resulting in the up-regulation of 14-3-3ζ, with consequent increased receptor tyrosine kinase signaling, increased cell proliferation and colony formation, and reduced apoptosis, thereby leading to tamoxifen resistance.