Review
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Stem Cells. Jul 26, 2021; 13(7): 685-736
Published online Jul 26, 2021. doi: 10.4252/wjsc.v13.i7.685
Mechanisms involved in selecting and maintaining neuroblastoma cancer stem cell populations, and perspectives for therapeutic targeting
Antonietta Rosella Farina, Lucia Annamaria Cappabianca, Veronica Zelli, Michela Sebastiano, Andrew Reay Mackay
Antonietta Rosella Farina, Lucia Annamaria Cappabianca, Veronica Zelli, Michela Sebastiano, Andrew Reay Mackay, Department of Applied Clinical and Biotechnological Sciences, University of L'Aquila, L'Aquila 67100, AQ, Italy
Author contributions: Mackay AR and Farina AR were responsible for several articles reviewed in this manuscript and co-wrote this review; Cappabianca LA was involved in several articles reviewed in this manuscript; Zelli V researched literature for this manuscript; Sebastiano M was involved in research in an article reviewed in this manuscript, researched literature for this manuscript and revised the manuscript; All authors have read and approved the final manuscript.
Conflict-of-interest statement: The authors of this manuscript declare no conflicts of interest.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Andrew Reay Mackay, PhD, Associate Professor, Department of Applied Clinical and Biotechnological Sciences, University of L'Aquila, Via Vetoio, Coppito 2, L'Aquila 67100, AQ, Italy. andrewreay.mackay@univaq.it
Received: January 27, 2021
Peer-review started: January 27, 2021
First decision: February 28, 2021
Revised: March 9, 2021
Accepted: April 14, 2021
Article in press: April 14, 2021
Published online: July 26, 2021
Processing time: 177 Days and 2.8 Hours
Abstract

Pediatric neuroblastomas (NBs) are heterogeneous, aggressive, therapy-resistant embryonal tumours that originate from cells of neural crest (NC) origin and in particular neuroblasts committed to the sympathoadrenal progenitor cell lineage. Therapeutic resistance, post-therapeutic relapse and subsequent metastatic NB progression are driven primarily by cancer stem cell (CSC)-like subpopulations, which through their self-renewing capacity, intermittent and slow cell cycles, drug-resistant and reversibly adaptive plastic phenotypes, represent the most important obstacle to improving therapeutic outcomes in unfavourable NBs. In this review, dedicated to NB CSCs and the prospects for their therapeutic eradication, we initiate with brief descriptions of the unique transient vertebrate embryonic NC structure and salient molecular protagonists involved NC induction, specification, epithelial to mesenchymal transition and migratory behaviour, in order to familiarise the reader with the embryonic cellular and molecular origins and background to NB. We follow this by introducing NB and the potential NC-derived stem/progenitor cell origins of NBs, before providing a comprehensive review of the salient molecules, signalling pathways, mechanisms, tumour microenvironmental and therapeutic conditions involved in promoting, selecting and maintaining NB CSC subpopulations, and that underpin their therapy-resistant, self-renewing metastatic behaviour. Finally, we review potential therapeutic strategies and future prospects for targeting and eradication of these bastions of NB therapeutic resistance, post-therapeutic relapse and metastatic progression.

Keywords: Neural crest; Neuroblastoma; Cancer stem cells; Polyploid giant cancer cells molecular mechanisms; Therapeutic targeting; Tumour microenvironment

Core Tip: Cancer stem cells promote tumour-heterogeneity, post-therapeutic relapse and metastatic progression in neuroblastomas (NBs), by way of their drug-resistant, self-renewing and reversibly plastic phenotypes, and are, therefore, critical targets to eliminate if improvements in therapeutic outcomes are to be realized. Despite progress in understanding the molecular mechanisms that underpin NB cancer stem cell (CSC) selection, promotion and maintenance, efficacious CSC targeting remains difficult. Here we review the molecular mechanisms considered to regulate NB CSCs, together with the therapeutic strategies and future prospects for their eradication, highlighting the need for a better understanding and targeting of polyploid giant cancer cell states, future prospects for chimeric antigen receptor (CAR) cell immunotherapies, the need to identify additional functional cell surface NB CSC-specific targets and to develop better models for NB CSC experimental therapeutics.