ORIGINAL ARTICLE   

The Quarterly Journal of Nuclear Medicine and Molecular Imaging 2020 December;64(4):393-9

DOI: 10.23736/S1824-4785.18.03088-1

Copyright © 2020 EDIZIONI MINERVA MEDICA

lingua: Inglese

Correlation of 18F-FDG uptake and thyroid cancer stem cells

Ya-Ju HSIEH ^{1, 2}, Tzu-Ying LU ³, Chien-Chih KE ^{4, 5}, Yaoh-Shiang LIN ⁶, Hsiao-Ting TAI ², Shiuh-Inn LIU ⁷, Tsung-Jung LIANG ⁷, Hsing-Hao SU ⁶, Ren-Shyan LIU ^{4, 5, 8, 9, 10, 11}, Nan-Jing PENG ^{12, 13} ✉

¹ Department of Medical Imaging and Radiological Sciences, Drug Development and Value Creation Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan; ² Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; ³ Department of Radiation Oncology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; ⁴ Biomedical Imaging Research Center, National Yang-Ming University, Taipei, Taiwan; ⁵ Molecular and Genetic Imaging Core, Taiwan Mouse Clinic, National Comprehensive Mouse Phenotyping and Drug Testing Center, Taipei, Taiwan; ⁶ Department of Otolaryngology Head and Neck, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan; ⁷ Division of General Surgery, Department of Surgery, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan; ⁸ National PET/Cyclotron Center and Department of Nuclear Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; ⁹ Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan; ¹⁰ Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan; ¹¹ Biophotonic and Molecular Imaging Research Center, National Yang-Ming University, Taipei, Taiwan; ¹² National Yang-Ming University School of Medicine, Taipei, Taiwan; ¹³ Department of Nuclear Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan

BACKGROUND: 2-deoxy-2-[¹⁸F]fluoro-D-glucose positron emission tomography (¹⁸F-FDG PET) has the potential to detect various types of cancers, including thyroid cancer (TC), at a potentially curable stage. Increased uptake of ¹⁸F-FDG was observed in anaplastic and poorly differentiated thyroid cancer cells, and PET-positive tumors are more likely to be resistant to ¹³¹I treatment. As cancer stem cells (CSCs) possess a dedifferentiated phenotype and are resistant to many anticancer therapies, we hypothesized that the expression of CSC-related markers is correlated with the ability of tumor cells in TC to uptake FDG.
METHODS: The present study cohort included 12 patients with TC, who underwent ¹⁸F-FDG PET/CT imaging before surgery. Quantitative polymerase chain reaction (QPCR) and immunohistochemical (IHC) staining were performed to analyze the expression patterns of gene markers related to embryonic stem (ES) cells and CSCs in TC.
RESULTS: The mRNA expression levels of CSC- (CD133 and CD44) and ES-related genes (Oct4 and Nanog) were higher in TC tissue than in normal thyroid tissue, whereas the mRNA expression levels of thyroid-specific genes (Tg, TSHR, and TTF1) were higher in normal thyroid tissue than in TC tissue. There was a positive and statistically significant correlation between FDG uptake (SUVmax) of tumor and relative mRNA levels of CD133, CD44, Oct4, and Nanog. The IHC results demonstrated that CD133 and Nanog were expressed in TC tissue but not in normal thyroid tissue, however, CD44 expression was observed in both TC and normal thyroid tissue. Comparisons of the clinicopathological parameters between TC tissues with low and high SUVmax demonstrated significant differences in protein level of CD133 but not in that of Nanog.
CONCLUSIONS: The pre-therapeutic tumor SUVmax obtained from ¹⁸F-FDG PET/CT may be a potential predictor for evaluating the proportion of CSC population in individual patients with TC.

KEY WORDS: Fluorodeoxyglucose F18; Positron-emission tomography; Thyroid neoplasms; Neoplastic stem cells