STEM CELLS IN BREAST CANCER: THE ROLE OF GENDER STEROID RECEPTORS

Abstract

Breast cancer (BC ) is the most common cancer among women, and current treatments available often have high success rates. However, BC can acquire drug resistance and sometimes relapse. Current knowledge about the most aggressive forms of BC indicates the role of specific cells with stem properties located in BC, the so-called "BCSCs" (Brest cancer stem cells). The role of BCSCs in cancer formation, growth, invasiveness, therapy resistance, and tumor recurrence is becoming increasingly evident. The growth and metastatic properties of BCSCs are regulated in a variety of ways that are only partially known. Sex steroid receptors (SSRs), which are involved in the etiology and progression of BC, promote the proliferation, dedifferentiation and migration of BCSCs. However, the literature contains incomplete information about their roles. In particular, there are conflicting findings regarding the expression and role of classic BC hormone biomarkers such as estrogen receptor alpha (ERα), together with scanty, albeit promising, information on the properties of ER-beta (ERβ) and androgen receptor (AR) that control pathways of transduction in BCSC. In this review, we will discuss the role that SRs expressed in BCSCs play in BC progression and relapse, and how these findings have opened up new therapeutic options. These cells are predictors of BC and promising new therapies are being developed to target these cells and improve BC recurrence.