Breast Cancer: Targets and Therapy

Hormone Receptors and Receptor Tyrosine Kinases in Breast Cancer

Nuclear receptors are normally activated by their ligands, which are mostly steroid hormones that can cross the plasma membranes to bind their target receptors. Upon activation, hormone receptors translocate to the nucleus to serve as transcription factors by controlling the expression of specific genes involved in the regulation of numerous cellular processes. Hormone receptors are particularly important in breast cancer biology. Most breast cancers are luminal tumors characterized by the overexpression of hormone receptors; estrogen receptors (ERs) and progesterone receptors (PRs). Luminal breast cancers are dependent upon estrogen and/or progesterone for their growth making endocrine/hormonal therapies a gold-standard approach for the treatment of luminal cancers.