Galectin-3 Targeting in Thyroid Orthotopic Tumors Opens New Ways to Characterize Thyroid Cancer
Galectin-3 Targeting in Thyroid Orthotopic Tumors Opens New Ways to Characterize Thyroid Cancer
复制标题
DOI：
10.2967/jnumed.118.219105
复制
发表时间：
2019-06-01
影响因子：
9.3
通讯作者：
D'Alessandria, Calogero
中科院分区：
文献类型：
--
作者：
De Rose, Francesco;Braeuer, Miriam;D'Alessandria, Calogero
甲状腺结节的术前表征具有挑战性，因为甲状腺闪烁扫描无法区分良性和恶性病变。 Galectin-3 (gal-3) 在分化良好和未分化的甲状腺癌中表达，但在正常甲状腺细胞和良性甲状腺病变中不表达。在此，我们的目的是验证 gal-3 靶向作为在甲状腺原位肿瘤模型中检测非放射性碘甲状腺癌的特定方法。方法：通过蛋白质印迹和聚合酶链反应对乳头状 (BcPAP) 和间变性 (CAL62 和 FRO82-1) 甲状腺癌细胞系进行 gal-3 和碘化钠同向转运蛋白 (NIS) 表达的表征。生成 Zr-89 标记的 F(ab')(2) antigal-3，并表征其在 2 维和 3 维细胞培养物上与 I-125 的结合。将甲状腺癌细胞接种到无胸腺裸鼠的甲状腺左叶，通过超声和荧光分子断层扫描监测原位肿瘤生长。对 I-124 与 Zr-89-去铁胺 (DFO)-F(ab')(2) 抗gal-3 进行头对头 PET/CT 比较，然后进行生物分布研究以及 gal-3 和 NIS 表达的免疫组织化学分析。结果：所研究的甲状腺癌细胞始终为 gal-3 阳性，同时 NIS 表达较低或缺失。 Zr-89-DFO-F(ab')(2) 抗gal-3 示踪剂对 gal-3 显示出高亲和力（解离常数，类似于 3.9 nM），并在二维细胞培养物和肿瘤球体上保留免疫反应性 (>75%)。 FRO82-1、BcPAP 和 CAL62 中的 I-125 内化直接依赖于二维和肿瘤球体中的 NIS 表达。 PET/CT 成像显示 Zr-89-DFO-F(ab')(2) 抗gal-3 信号仅与原位植入的肿瘤相关；在无肿瘤的甲状腺叶中未检测到信号。相反，使用 I-124 的 PET 成像显示肿瘤浸润叶中有背景积累，这是模拟非放射性碘甲状腺癌结节存在的情况，而正常甲状腺叶中有高积累。成像数据通过示踪剂生物分布研究和免疫组织化学得到证实。结论：在没有放射性碘摄取的情况下，通过靶向 gal-3 证明了甲状腺肿瘤的特异性和选择性可视化。将这种方法转化为临床环境有望通过避免使用非特异性成像方法并减少不必要的甲状腺手术来改善患者的管理。
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 Zr-89-labeled F(ab')(2) antigal-3 was generated and characterized for binding versus I-125 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 I-124 versus Zr-89-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. Zr-89-DFO-F(ab')(2) antigal-3 tracer showed high affinity to gal-3 (dissociation constant, similar to 3.9 nM) and retained immunoreactivity (>75%) on 2-dimensional cell cultures and on tumor spheroids. I-125 internalization in FRO82-1, BcPAP, and CAL62 was directly dependent on NIS expression, both in 2-dimensional and tumor spheroids. PET/CT imaging showed Zr-89-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 I-124 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.