Wang S, Yuan Y, Liao L et al.
Baylor College of Medicine, Houston, TX, USA.
Proc Natl Acad Sci U S A 2009;106:151–6.
Editor’s note: The p160 steroid receptor coactivator (SRC) family consists of three members – SRC-1, SRC-2, and SRC-3 – that interact with transcription factors to modulate the transcription of genes. The combination, concentration, and post-translational modification of these coactivators determine the specificity and efficiency of gene transcription and thus play a vital role in the behavior of cells. The SRC family members all interact with nuclear hormone receptors but also react with other transcription factors to control gene expression. SRC-3 is upregulated and overexpressed in breast cancer, and although normal mammary epithelial cells have very low levels of SRC-1, expression of this member of the family is also increased in breast cancer. SRC-1 expression has been shown to be associated with HER2 positivity and resistance to endocrine therapy in breast cancer patients.