Gene expression signatures for a basal-like breast cancer (BLBC) subtype have been associated with poor clinical outcomes, but a molecular basis for this disease remains unclear. Here, we report overexpression of the transcription factor FOXC1 as a consistent feature of BLBC compared with other molecular subtypes of breast cancer. Elevated FOXC1 expression predicted poor overall survival in BLBC (P = 0.0001), independently of other clinicopathologic prognostic factors including lymph node status, along with a higher incidence of brain metastasis (P = 0.02) and a shorter brain metastasis-free survival in lymph node-negative patients (P < 0.0001). Ectopic overexpression of FOXC1 in breast cancer cells increased cell proliferation, migration, and invasion, whereas shRNA-mediated FOXC1 knockdown yielded opposite effects. Our findings identify FOXC1 as a theranostic biomarker that is specific for BLBC, offering not only a potential prognostic candidate but also a potential molecular therapeutic target in this breast cancer subtype.

doi.org/10.1158/0008-5472.CAN-09-4120, hdl.handle.net/1765/27674
Cancer Research
Erasmus MC: University Medical Center Rotterdam

Ray, P., Wang, J., Qu, Y., Sim, M. S., Shamonki, J., Bagaria, S., … Cui, X. (2010). FOXC1 is a potential prognostic biomarker with functional significance in basal-like breast cancer. Cancer Research, 70(10), 3870–3876. doi:10.1158/0008-5472.CAN-09-4120