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Updated: Aug 14, 2026
An Orthotopic Mouse Model of Anaplastic Thyroid Carcinoma
Published on: April 17, 2013
Bright Visualization of Primary and Metastatic Medullary Thyroid Cancer in an Orthotopic Nude Mouse Model Using a
Javier Bravo1,2, Sohee Lee1,2,3, Blackberrie Eddins1,2
1Department of Surgery, UCSD Moores UCSD Cancer Center, University of California San Diego, La Jolla, CA, USA.
Background:
The standard treatment for medullary thyroid cancer (MTC) is total thyroidectomy with cervical lymph node dissection. Cure depends on complete surgical resection; however, intraoperative identification of tumor margins and involved lymph nodes remains challenging.
Methods:
The CEA-expressing MTC cell line TT was used to establish orthotopic thyroid tumor models (n = 7), whereas the non-CEA-expressing papillary thyroid cancer (PTC) cell line TPC-1 was used to establish subcutaneous negative control tumor models (n = 3). Orthotopic MTC models were established by injecting TT cells (1x107) into the thyroid gland of athymic nude mice, whereas subcutaneous models were established by implanting TT and TPC-1 tumors into the flanks of nude mice. The humanized anti-CEA antibody M5A was conjugated to the near infrared fluorophore IRDye800CW to generate M5A-IR800. Mice received 50 µg of M5A-IR800 via tail vein injection and were imaged under bright light and fluorescence using a LI-COR Pearl Imaging System. Tumor-to-background ratios (TBR) were calculated as the ratio of mean tumor fluorescence intensity to surrounding tissue. Tumor specimens were analyzed by histology and immunohistochemistry.
Results:
The mean TBR of orthotopic MTC tumors treated with M5A-IR800 was 6.85 (±3.75) at 96 hours post injection. Mice bearing subcutaneous TT tumors also achieved high TBRs of 4.23, 3.59, and 3.3 at 96 hours. In contrast, non-CEA-expressing TPC-1 tumors demonstrated no detectable fluorescence. Hematoxylin and eosin staining and immunohistochemistry confirmed accurate tumor targeting by M5A-IR800 and strong CEA expression in MTC tumors.
Conclusions:
M5A-IR800 specifically and brightly targets MTC in preclinical mouse models and represents a promising approach to enhance intraoperative visualization of MTC.
