Translational evidence on the role of Src kinase and activated Src kinase in invasive breast cancer.

Src kinase is a member of a non-receptor tyrosine kinase family. It has been implicated as a regulator of cell proliferation and survival and plays a complex role in cell adhesion and motility. In vitro evidence for a role for Src in breast cancer is compelling. However, only a few translational clinical studies have been undertaken in this field. This review summarises translational evidence on expression and activation of Src kinase in breast cancer patient cohorts exploring clinical significance and the possibility of identifying key biomarkers. There is strengthened translational proof for a definitive role of Src in breast cancer. Nevertheless, there remains a need to find a robust biomarker to identify patients responsive to Src inhibitors for clinical trials.