Src kinase: a therapeutic opportunity in endocrine-responsive and resistant breast cancer

Abstract

The intracellular kinase, Src, interacts with a diverse array of signaling elements, including the estrogen receptor to regulate breast cancer progression. Recent evidence has also implicated Src in mediating the response of breast cancer to endocrine agents and in the acquisition of antihormone resistance, a significant limiting factor to the clinical effectiveness of systemic endocrine therapy. A number of pharmacological inhibitors of Src kinase have been developed that are effective at suppressing breast cancer growth and invasion in vitro and inhibiting disease spread in vivo. Significantly, there appears to be added benefit when these agents are given in combination with anti-estrogens in endocrine-sensitive and -resistant models. These new findings suggest that Src inhibitors might have therapeutic value in breast cancer patients to improve endocrine response and circumvent resistance.