RNA interference screening identifies the Insulin/IGF-1 receptor pathway as a mechanism of escape from hormone dependence in breast cancer

A significant fraction of breast cancers exhibit de novo or acquired resistance to estrogen deprivation. A kinome-wide siRNA screen identified a role for Insulin Receptor (InsR) in the hormone-independent growth of ER+ breast cancer cells We used gene expression microarrays to identify genes and pathways that are altered by insulin stimulation of ER+ MCF-7 human breast cancer cells. MCF-7 cells were treated with serum-free medium +/- insulin for 4 or 24 hrs prior to RNA harvest for analysis.