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Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Stem Cells. Sep 26, 2019; 11(9): 594-603
Published online Sep 26, 2019. doi: 10.4252/wjsc.v11.i9.594
Breast cancer stem cells: The role of sex steroid receptors
Pia Giovannelli, Marzia Di Donato, Giovanni Galasso, Erika Di Zazzo, Nicola Medici, Antonio Bilancio, Antimo Migliaccio, Gabriella Castoria
Pia Giovannelli, Marzia Di Donato, Giovanni Galasso, Erika Di Zazzo, Nicola Medici, Antonio Bilancio, Antimo Migliaccio, Gabriella Castoria, Department of Precision Medicine, University of Campania “L. Vanvitelli”, Naples 80138, Italy
Author contributions: Giovannelli P wrote and drafted the original article; Giovannelli P, Castoria G, Di Donato M, Galasso G, Di Zazzo E, Medici N and Bilancio A wrote, reviewed and edited the article; Castoria G and Migliaccio A supervised the project; Castoria G and Migliaccio A acquired the funding.
Supported by the National Ministry of University and Research, Programmi di Ricerca Scientifica di Rilevante Interesse Nazionale, No. 2017EKMFTN_002, No. 2015B7M39T_003; Umberto Veronesi Foundation Post-doctoral Fellowship 2019; Program VALERE (Vanvitelli per la Ricerca- University of Campania "L. Vanvitelli").
Conflict-of-interest statement: All authors declare they have no potential conflicts of interest.
Corresponding author: Pia Giovannelli, PhD, Department of Precision Medicine, University of Campania “L. Vanvitelli”, Via L. De Crecchio, 7, Naples 80138, Italy. pia.giovannelli@unicampania.it
Telephone: +39-81-5667555 Fax: +39-81-5667555
Received: February 28, 2019
Peer-review started: March 4, 2019
First decision: April 11, 2019
Revised: May 6, 2019
Accepted: August 20, 2019
Article in press: August 20, 2019
Published online: September 26, 2019
Processing time: 209 Days and 12.9 Hours
Abstract

Breast cancer (BC) is the most common cancer among women, and current available therapies often have high success rates. Nevertheless, BC might acquire drug resistance and sometimes relapse. Current knowledge about the most aggressive forms of BC points to the role of specific cells with stem properties located within BC, the so-called “BC stem cells” (BCSCs). The role of BCSCs in cancer formation, growth, invasiveness, therapy resistance and tumor recurrence is becoming increasingly clear. The growth and metastatic properties of BCSCs are regulated by different pathways, which are only partially known. Sex steroid receptors (SSRs), which are involved in BC etiology and progression, promote BCSC proliferation, dedifferentiation and migration. However, in the literature, there is incomplete information about their roles. Particularly, there are contrasting conclusions about the expression and role of the classical BC hormonal biomarkers, such as estrogen receptor alpha (ERα), together with scant, albeit promising information concerning ER beta (ERβ) and androgen receptor (AR) properties that control different transduction pathways in BCSCs. In this review, we will discuss the role that SRs expressed in BCSCs play to BC progression and recurrence and how these findings have opened new therapeutic possibilities.

Keywords: Breast cancer; Steroids; Sex steroid receptors; Cancer stem cells; Therapeutic implications

Core tip: Many studies have reported the presence of cancer stem cells (CSCs) in breast cancer (BC), highlighting the correlation between CSCs and BC aggressiveness. Sex steroids and steroid receptors play a pivotal role in BCSCs. By controlling different pathways, BCSCs are able to influence both BC recurrence and drug resistance. Therefore, better knowledge of BCSC features and behavior would be useful to employ these cells as BC prognostic factors, and develop new promising therapies targeting these cells and improving BC recurrence.