Abstract
Breast cancer is the most common form of tumor in women and the leading cause of cancer-related mortality. Even though the major cellular burden in breast cancer is constituted by the so-called bulk tumor cells, another cell subpopulation named cancer stem cells (CSCs) has been identified. The latter have stem features, a self-renewal capacity, and the ability to regenerate the bulk tumor cells. CSCs have been described in several cancer types but breast cancer stem cells (BCSCs) were among the first to be identified and characterized. Therefore, many efforts have been put into the phenotypic characterization of BCSCs and the study of their potential as prognostic indicators and therapeutic targets. Many dysregulated pathways in BCSCs are involved in the epithelial–mesenchymal transition (EMT) and are found up-regulated in circulating tumor cells (CTCs), another important cancer cell subpopulation, that shed into the vasculature and disseminate along the body to give metastases. Conventional therapies fail at eliminating BCSCs because of their quiescent state that gives them therapy resistance. Based on this evidence, preclinical studies and clinical trials have tried to establish novel therapeutic regimens aiming to eradicate BCSCs. Markers useful for BCSC identification could also be possible therapeutic methods against BCSCs. New approaches in drug delivery combined with gene targeting, immunomodulatory, and cell-based therapies could be promising tools for developing effective CSC-targeted drugs against breast cancer.
Highlights
Breast cancer is the highest incidence cancer and the leading cause of cancer-related mortality among women [1]
Other strategies are based on the identification, by specific antibodies or ligands loaded onto nanoparticles, of particular receptors overexpressed on breast cancer stem cells (BCSCs) [145]
Many efforts have been made in the isolation and characterization of breast cancer stem cells (BCSCs), as well as in the identification of possible markers to target this cell population
Summary
Breast cancer is the highest incidence cancer and the leading cause of cancer-related mortality among women [1]. BCSCs have been extensively studied for years because of two main features that are crucial in cancer prognosis and progression: (1) their capacity to induce the epithelial–mesenchymal transition (EMT), to undergo self-renovation, and to give birth to new bulk tumor cells [6]; and (2) their resistance to conventional therapies [7]. Many useful markers for the characterization and identification of CSCs can be both possible therapeutic targets to eliminate BCSCs and indicators of response to therapy. Among these markers, there are molecules involved mainly in self-renewal and survival, such as Notch, Hedgehog, Wnt, PI3K/Akt/mTOR, IL-8, HER2 and the TGF-β pathway [27]. New technologies in drug delivery, combined with gene targeting, differentiating agents, immunomodulatory, and cell-based therapies, are promising tools for developing effective CSC-targeted drugs against breast cancer
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
