Tyrosine kinase signalling in breast cancer - ErbB family receptor tyrosine kinases

ERBB family receptor tyrosine kinases are overexpressed in a significant su bset of breast cancers. One of these receptors, HER2/neu, or ErbB-2, is the target for a new rational therapeutic antibody, Herceptin. Other inhibitor s that target this receptor, and another family member, the epidermal growt h factor (EGF) receptor, are moving into clinical trials. Both of these rec eptors are sometimes overexpressed in breast cancer, and still subject to r egulation by hormones and other physiological regulators. Optimal use of th erapeutics targeting these receptors will require consideration of the seve ral modes of regulation of these receptors and their interactions with ster oid receptors.