TY - JOUR
T1 - Galectin-3 targeting in thyroid orthotopic tumors opens new ways to characterize thyroid cancer
AU - De Rose, Francesco
AU - Braeuer, Miriam
AU - Braesch-Andersen, Sten
AU - Otto, Angela M.
AU - Steiger, Katja
AU - Reder, Sybille
AU - Mall, Sabine
AU - Nekolla, Stephan
AU - Schwaiger, Markus
AU - Weber, Wolfgang A.
AU - Bartolazzi, Armando
AU - D’Alessandria, Calogero
N1 - Publisher Copyright:
© 2019 by the Society of Nuclear Medicine and Molecular Imaging.
PY - 2019/6
Y1 - 2019/6
N2 - Preoperative characterization of thyroid nodules is challenging since thyroid scintigraphy fails to distinguish between benign and malignant lesions. Galectin-3 (gal-3) is expressed in well-differentiated and in undifferentiated thyroid cancer types but not in normal thyrocytes and benign thyroid lesions. Herein, we aimed to validate gal-3 targeting as a specific method to detect non–radioiodine-avid thyroid cancer in thyroid orthotopic tumor models. Methods: Papillary (BcPAP) and anaplastic (CAL62 and FRO82-1) thyroid carcinoma cell lines were characterized via Western blot and polymerase chain reaction for gal-3 and sodium-iodide symporter (NIS) expression. An 89Zr-labeled F(ab′)2 antigal-3 was generated and characterized for binding versus 125I on 2- and 3-dimensional cell cultures. The thyroid carcinoma cells were inoculated into the left thyroid lobe of athymic nude mice, and the orthotopic tumor growth was monitored via ultrasound and fluorescence molecular tomography. Head-to-head PET/CT comparison of 124I versus 89Zr-deferoxamine (DFO)-F(ab′)2 antigal-3 was performed, followed by biodistribution studies and immunohistochemical analysis for gal-3 and NIS expression. Results: The thyroid carcinoma cells investigated were invariably gal-3–positive while presenting low or lost NIS expression. 89Zr-DFO-F(ab′)2 antigal-3 tracer showed high affinity to gal-3 (dissociation constant, ∼3.9 nM) and retained immunoreactivity (.75%) on 2-dimensional cell cultures and on tumor spheroids. 125I internalization in FRO82-1, BcPAP, and CAL62 was directly dependent on NIS expression, both in 2-dimensional and tumor spheroids. PET/CT imaging showed 89Zr-DFO-F(ab′)2 antigal-3 signal associated with the orthotopically implanted tumors only; no signal was detected in the tumor-free thyroid lobe. Conversely, PET imaging using 124I showed background accumulation in tumor-infiltrated lobe, a condition simulating the presence of non–radioiodine-avid thyroid cancer nodules, and high accumulation in normal thyroid lobe. Imaging data were confirmed by tracer biodistribution studies and immunohistochemistry. Conclusion: A specific and selective visualization of thyroid tumor by targeting gal-3 was demonstrated in the absence of radioiodine uptake. Translation of this method into the clinical setting promises to improve the management of patients by avoiding the use of unspecific imaging methodologies and reducing unnecessary thyroid surgery.
AB - Preoperative characterization of thyroid nodules is challenging since thyroid scintigraphy fails to distinguish between benign and malignant lesions. Galectin-3 (gal-3) is expressed in well-differentiated and in undifferentiated thyroid cancer types but not in normal thyrocytes and benign thyroid lesions. Herein, we aimed to validate gal-3 targeting as a specific method to detect non–radioiodine-avid thyroid cancer in thyroid orthotopic tumor models. Methods: Papillary (BcPAP) and anaplastic (CAL62 and FRO82-1) thyroid carcinoma cell lines were characterized via Western blot and polymerase chain reaction for gal-3 and sodium-iodide symporter (NIS) expression. An 89Zr-labeled F(ab′)2 antigal-3 was generated and characterized for binding versus 125I on 2- and 3-dimensional cell cultures. The thyroid carcinoma cells were inoculated into the left thyroid lobe of athymic nude mice, and the orthotopic tumor growth was monitored via ultrasound and fluorescence molecular tomography. Head-to-head PET/CT comparison of 124I versus 89Zr-deferoxamine (DFO)-F(ab′)2 antigal-3 was performed, followed by biodistribution studies and immunohistochemical analysis for gal-3 and NIS expression. Results: The thyroid carcinoma cells investigated were invariably gal-3–positive while presenting low or lost NIS expression. 89Zr-DFO-F(ab′)2 antigal-3 tracer showed high affinity to gal-3 (dissociation constant, ∼3.9 nM) and retained immunoreactivity (.75%) on 2-dimensional cell cultures and on tumor spheroids. 125I internalization in FRO82-1, BcPAP, and CAL62 was directly dependent on NIS expression, both in 2-dimensional and tumor spheroids. PET/CT imaging showed 89Zr-DFO-F(ab′)2 antigal-3 signal associated with the orthotopically implanted tumors only; no signal was detected in the tumor-free thyroid lobe. Conversely, PET imaging using 124I showed background accumulation in tumor-infiltrated lobe, a condition simulating the presence of non–radioiodine-avid thyroid cancer nodules, and high accumulation in normal thyroid lobe. Imaging data were confirmed by tracer biodistribution studies and immunohistochemistry. Conclusion: A specific and selective visualization of thyroid tumor by targeting gal-3 was demonstrated in the absence of radioiodine uptake. Translation of this method into the clinical setting promises to improve the management of patients by avoiding the use of unspecific imaging methodologies and reducing unnecessary thyroid surgery.
KW - Galectin-3
KW - I
KW - Orthotopic models
KW - PET imaging
KW - Thyroid tumor
UR - http://www.scopus.com/inward/record.url?scp=85067032466&partnerID=8YFLogxK
U2 - 10.2967/jnumed.118.219105
DO - 10.2967/jnumed.118.219105
M3 - Article
C2 - 30361380
AN - SCOPUS:85067032466
SN - 0161-5505
VL - 60
SP - 770
EP - 776
JO - Journal of Nuclear Medicine
JF - Journal of Nuclear Medicine
IS - 6
ER -
