Thyroid status modulates the formation of breast cancer metastasis

GONZALEZ G; DEBERNARDI M; MENAY F; JOHANNA A. DIAZ ALBUJA; CAMPOS HAEDO MATEO; PAULAZO A; DÍAZ FLAQUÉ MC; ROSEMBLIT C; CAYROL F; CREMASCHI G; STERLE HA

Congreso; Reunión Anual de la Sociedad Argentina de Fisiología (SAFIS); 2023

Introduction: The association between thyroid status and breast cancer progression has not yet been completely clarified. We have previously described that hyperthyroid mice that have been inoculated with the 4T1 breast cancer cell line showed increased primary tumor growth rate, while hypothyroid mice developed a reduced tumor growth rate but an increased number of lung metastases. Objectives: To evaluate the effect of thyroid status on the mechanisms involved in the metastatic process in breast cancer, particularly on the epithelial-to-mesenchymal transition (EMT), the activity of matrix-metalloproteases (MMPs) and the production of chemokines by the tumor; and the composition of the immune microenvironment in the lungs. Methods: Female Balb/c mice were treated with propylthiouracil (PTU) for 2 weeks to obtain hypothyroid mice, or thyroxine (T4) for 4 weeks to obtain hyperthyroid animals. Mice were then orthotopically inoculated with 4T1 cells and after 21 or 35 days, tumors and lungs were excised and analyzed. Results: Primary tumors from hypothyroid mice exhibited a higher mRNA expression ofVimentin and a lower expression of E-cadherin than tumors from eu- and hyperthyroid animals (p