# Iodothyronine Deiodinase 3 Gene Expression in Gastrointestinal Stromal Tumors: A Pilot Study to Contribute to Risk Assessment

## TL;DR

This study explores the role of the DIO3 gene in gastrointestinal stromal tumors and its potential as a prognostic marker.

## Contribution

The study is the first to investigate DIO3 gene expression in GIST and its association with tumor characteristics and risk.

## Key findings

- DIO3 overexpression was observed in 69.70% of GIST tumors.
- DIO3 expression was significantly higher in very low/low-risk patients.
- A potential link between DIO3 and DOG1 markers was identified.

## Abstract

Background: In the realm of gastrointestinal stromal tumors (GIST), understanding the molecular landscape and prognostic factors is crucial for effective management. The deiodinase 3 gene (DIO3), known for its role in thyroid hormone regulation and cell proliferation, has emerged as a potential player in GIST pathogenesis. Our study investigated DIO3 expression in GIST samples and its correlation with tumor characteristics, aiming to enhance prognostic stratification and personalized treatment strategies.

Materials and methods: Using a retrospective design, we analyzed data and formalin-fixed paraffin-embedded (FFPE) samples of patients diagnosed with GIST. The study cohort comprised 33 patients, predominantly female, with a median age of 66 years. The tumor characteristics were meticulously documented, including location, size, mitotic count, risk classification, and immunohistochemical markers. Gene expression analysis of DIO3 was conducted using FFPE samples, with a focus on relative quantification and association with immunohistochemical markers and prognostic risk.

Results: DIO3 overexpression was observed in 69.70% of tumors, while underexpression was noted in 30.30% of cases. Association analyses revealed intriguing insights. A notable association was identified between DIO3 expression and the frequency of DOG1, suggesting a potential interplay between these markers in GIST pathobiology. Furthermore, increased DIO3 expression was significantly higher in very low/low-risk prognostic patients, hinting at a possible link between DIO3 levels and tumor progression prognosis.

Conclusions: The intricate interplay between DIO3 expression and GIST characteristics uncovered in this study underscores the potential of molecular markers in refining prognostic assessments and therapeutic strategies for GIST patients.