Cancer Stem Cells in Tumours of the Central Nervous System in Children: A Comprehensive Review

SIMPLE SUMMARY: Tumours of the central nervous system (CNS) are the most common solid tumours in children. The difficulties in treating this complicated variety of tumours are that they lead to high mortalities. Cancer stem cells (CSCs) are a subgroup of cells found in various kinds of tumours with stem cell characteristics, such as self-renewal, induced differentiation, and tumourigenicity. The biological functions and clinical significance of CSCs in CNS tumours in children have been reported in the last few decades. However, there is no comprehensive review in this field and the information has been fragmented and confusing. Thus, we collected valuable data and findings from these reports to make a clear and concentrated review to provide a train of thought for experts in the field. ABSTRACT: Cancer stem cells (CSCs) are a subgroup of cells found in various kinds of tumours with stem cell characteristics, such as self-renewal, induced differentiation, and tumourigenicity. The existence of CSCs is regarded as a major source of tumour recurrence, metastasis, and resistance to conventional chemotherapy and radiation treatment. Tumours of the central nervous system (CNS) are the most common solid tumours in children, which have many different types including highly malignant embryonal tumours and midline gliomas, and low-grade gliomas with favourable prognoses. Stem cells from the CNS tumours have been largely found and reported by researchers in the last decade and their roles in tumour biology have been deeply studied. However, the cross-talk of CSCs among different CNS tumour types and their clinical impacts have been rarely discussed. This article comprehensively reviews the achievements in research on CSCs in paediatric CNS tumours. Biological functions, diagnostic values, and therapeutic perspectives are reviewed in detail. Further investigations into CSCs are warranted to improve the clinical practice in treating children with CNS tumours.