NIFUROXAZIDE ACTIVITY IN ANAPLASTIC THYROID CANCER: MODULATION OF CANCER STEM-LIKE CELL PROPERTIES THROUGH JAK/STAT3 PATHWAY

• Grant number: 24/21269-2
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: October 01, 2025
• End date: September 30, 2028
• Field of knowledge: Biological Sciences - Biochemistry - Molecular Biology
• Principal Investigator: Ileana Gabriela Sánchez de Rubió
• Grantee: Gustavo Felisola Caso
• Host Institution: Instituto de Ciências Ambientais, Químicas e Farmacêuticas (ICAQF). Universidade Federal de São Paulo (UNIFESP). Campus Diadema. Diadema , SP, Brazil

Abstract

Anaplastic thyroid carcinoma (ATC) is the rarest and most aggressive thyroid cancer (TC),surviving for 6 - 15 months due to resistance acquisition. The tumors do not respond toradioiodine therapy and the therapeutic options are limited. Most cases of TC occur due toPI3K/AKT/mTOR and MAPK pathways activation, while in ATC JAK/STAT constitutiveactivation has been associated with tumor development, progression, resistance, and cancerstem-like cells properties. Cancer stem cells (CSCs) have been related to cancer self-renewaland recurrence and have already been detected in ATC. The antimicrobial and antiparasitic drugnifuroxazide (NFZ) was able to reduce cell viability in some cancer models by inhibiting theJAK/STAT pathway. In melanoma, NFZ was bio-activated by ALDH1A3, a CSCs biomarker,suggesting NFZ selectivity over this cell population. Up to now, no data is available on NFZand CSCs in ATC. Thus, this study aims to evaluate the activity of NFZ on the JAK/STATpathway in the ATC cancer stem-like cells properties. Three ATC cell lines, KTC-2, HTH83and 8305c, will be used. ALDH activity will be monitored using ALDEFLUOR fluorophoreand the ALDH1A3 and other CSCs markers (SOX2, CD44, CD133 and CD326) expressionswill be evaluated by real time PCR and flow cytometry, as well as spheres formation assay.Cell viability assays will be carried out using ALDH inhibitor to confirm whether the NFZaction on ATC depends on ALDH activity. Subpopulations with high and low ALDH activitywill be identified through cell sorting. The role of JAK/STAT pathway in cancer stem-like cellsproperties will be evaluated using cell lines with STAT3 deleted by CRISPR/Cas9 technique,available in laboratory. In addition, an in vivo Zebrafish model will be used to evaluate theformation of xenotumors before and after cell sorting, as well as the activity of NFZ as aninhibitor of this formation and the relationship of the JAK/STAT3 pathway using cell lines withdeletion in STAT3. Therefore, at the end of this project we expect to obtain original andimportant results of the crosstalk between the JAK/STAT pathway and CSCs, the NFZrepositioning as JAK/STAT3 pathway inhibitor and its selectivity to CSCs, highly related tothe aggressiveness and progression of cancer, as in the most aggressive form of thyroid cancerthyroid, the ATC.