AUTHOR=Nagayama Yuji , Shimamura Mika , Mitsutake Norisato 

TITLE=Cancer Stem Cells in the Thyroid

JOURNAL=Frontiers in Endocrinology

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2016.00020

DOI=10.3389/fendo.2016.00020

ISSN=1664-2392

ABSTRACT=<p>The cancer stem cell (CSC) model posits that CSCs are a small, biologically distinct subpopulation of cancer cells in each tumor that have self-renewal and multi-lineage potential, and are critical for cancer initiation, metastasis, recurrence, and therapy-resistance. Numerous studies have linked CSCs to thyroid biology, but the candidate markers and signal transduction pathways that drive thyroid CSC growth are controversial, the origin(s) of thyroid CSCs remain elusive, and it is unclear whether thyroid CSC biology is consistent with the original hierarchical CSC model or the more recent dynamic CSC model. Here, we critically review the thyroid CSC literature with an emphasis on research that confirmed the presence of thyroid CSCs by <italic>in vitro</italic> sphere formation or <italic>in vivo</italic> tumor formation assays with dispersed cells from thyroid cancer tissues or <italic>bona fide</italic> thyroid cancer cell lines. Future perspectives of thyroid CSC research are also discussed.</p>