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Nagayama. J Cancer Metastasis Treat 2021;7:6 Journal of Cancer
DOI: 10.20517/2394-4722.2020.114 Metastasis and Treatment

Review Open Access

Autophagy and thyroid cancer

Yuji Nagayama

Department of Molecular Medicine, Atomic Bomb Disease Institute, Nagasaki University, Nagasaki 852-8523 Japan.

Correspondence to: Dr. Yuji Nagayama, Department of Molecular Medicine, Atomic Bomb Disease Institute, Nagasaki University,
1-12-4 Sakamoto, Nagasaki 852-8523 Japan. E-mail: nagayama@nagasaki-u.ac.jp

How to cite this article: Nagayama Y. Autophagy and thyroid cancer. J Cancer Metastasis Treat 2021;7:6.
http://dx.doi.org/10.20517/2394-4722.2020.114

Received: 16 Oct 2020 First Decision: 24 Dec 2020 Revised: 28 Dec 2020 Accepted: 1 Jan 2021 Published: 15 Jan 2021
Academic Editor: Jerome M. Hershman Copy Editor: Monica Wang Production Editor: Jing Yu

Abstract
This review provides the up-to-date physiological, pathophysiological, and carcinogenic roles of autophagy in the
thyroid. The data on its physiological roles are mainly obtained with genetically engineered mice, demonstrating
the importance of autophagy for the maintenance of cell homeostasis and survival as well as provision of building
blocks for sufficient synthesis of proteins such as thyroglobulin. Positive and negative controls of autophagic activity
by thyrotropin and thyroid hormone, respectively, are now apparent. In thyroid cancer, there is no published study
on the role for autophagy in the initiation/development of thyroid cancer, and there exist many inconsistent data
regarding its role in established thyroid cancer behavior. For example, definitive conclusions remain to be elucidated
regarding the level of autophagic activity in thyroid cancer cells and the effect of autophagy inducers/inhibitors on
cancer cell survival/proliferation. Especially, when autophagy is targeted in novel cancer therapeutics, some studies
show its pro-survival, but others its anti-survival or context-dependent, effects on thyroid cancer cells. Further
studies are in the future necessary to further elucidate the potential of autophagy as a therapeutic target for thyroid
cancer.

Keywords: Thyroid, cancer, autophagy, pro-survival, anti-survival

INTRODUCTION
Thyroid cancer is the most common endocrine malignancy with its incidence rate being rapidly increasing
[1]
during the last several decades . The extensive studies on genetic/genomic landscapes of thyroid cancers
have identified the aberrant activation of the RAS-RAF-MEK-ERK signaling pathway by the point

© The Author(s) 2021. Open Access This article is licensed under a Creative Commons Attribution 4.0
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