Validation of Immunohistochemistry for Canine Proteins Involved in Thyroid Iodine Uptake and Their Expression in Canine Follicular Cell Thyroid Carcinomas (FTCs) and FTC-Derived Organoids

Abstract

Thyrotropin receptor (TSHR), sodium iodide symporter (NIS), pendrin, and thyroid peroxidase (TPO) are essential for the uptake of iodine by follicular thyroid cells. The aim of this study was to establish immunohistochemistry (IHC) protocols for TSHR, NIS, pendrin, and TPO in canine tissues and characterize their expression in organoids derived from canine follicular cell thyroid carcinoma (FTC) and in the respective primary tumors. This constitutes a fundamental step to establish organoids as a model to study the uptake of iodine in canine FTC. Commercially available antibodies directed against human proteins were selected. Antibody specificity was confirmed by western blot using lysates of the HTori-3 human thyroid cell line and healthy canine thyroid gland. IHC was validated using HTori-3 cells and a set of canine normal tissues including healthy thyroid gland. The expression of TSHR, NIS, pendrin, and TPO was evaluated in 3 organoid lines derived from FTC and respective primary tumors. All 4 antibodies produced specific bands by western blot and cytoplasmic labeling in follicular cells by IHC in both human HTori-3 cells and canine thyroid gland. NIS also showed basolateral membrane immunolabeling in follicular cells. All 4 proteins were highly expressed in organoids derived from FTC. The expression was similar or higher compared to the primary tumors. The results of this study characterize organoids derived from canine FTC as a suitable in vitro model to investigate iodine uptake, opening new research possibilities in the field of canine thyroid cancer therapy.

Farm and Companion Animal Organoid Models in Translational Research: A Powerful Tool to Bridge the Gap Between Mice and Humans

“…Thyroid organoids have been successfully generated from canine follicular cell thyroid carcinomas (FTCs) ( 95 ). Canine FTC-derived organoids conserved the expression of proteins involved in iodine uptake, and hence opened new research possibilities as an in vitro model to modulate iodine uptake and improve radioiodine therapy for thyroid cancer.…”

“…Canine FTC-derived organoids conserved the expression of proteins involved in iodine uptake, and hence opened new research possibilities as an in vitro model to modulate iodine uptake and improve radioiodine therapy for thyroid cancer. While development of thyroid cancer following transplantation of genetically engineered oncogenic thyroid organoids has been described in mouse ( 119 ), this is the first organoid model which is derived from spontaneous thyroid cancer in any species ( 95 ). Since FTCs, although rare, do occurs in humans ( 120 ), canine spontaneous cancer organoids would serve as a useful model for preclinical studies on human FTCs.…”

Advancing animal health and disease research in the lab with three‐dimensional cell culture systems

“…A canine thyroid organoid line was also recently developed from dogs with follicular cell thyroid carcinoma (FTC). 47 The FTC organoids express a number of important markers associated with this tissue, including thyrotropin receptor (TSHR), sodium iodide symporter (NIS), pendrin, and thyroid peroxidase (TPO), all of which are important for iodine uptake. Thus, the authors propose the FTC organoids will be useful for studying iodine uptake in a relevant model that will aid research towards the development of more effective therapies against canine thyroid cancer.…”

“…Thus, the authors propose the FTC organoids will be useful for studying iodine uptake in a relevant model that will aid research towards the development of more effective therapies against canine thyroid cancer. 47 Other endocrine disorders can also be studied using organoids. Cushing disease, a disorder caused by adrenocorticotropic hormone (ACTH)secreting adenomas in the pituitary gland, has a relatively high incidence rate in dogs and although treatable, drug-based therapy only works in approximately 40% of patients.…”

“…A canine thyroid organoid line was also recently developed from dogs with follicular cell thyroid carcinoma (FTC) 47 . The FTC organoids express a number of important markers associated with this tissue, including thyrotropin receptor (TSHR), sodium iodide symporter (NIS), pendrin, and thyroid peroxidase (TPO), all of which are important for iodine uptake.…”