# Autophagy-Related Proteins’ Immunohistochemical Expression and Their Potential Role as Biomarkers in Thymic Epithelial Tumors

## TL;DR

This study explores autophagy proteins in thymic tumors, finding links to tumor type and stage, but not survival or relapse.

## Contribution

The study identifies autophagy-related proteins as potentially relevant in advanced thymic tumors but not as reliable survival biomarkers.

## Key findings

- Higher BECLIN and p62 levels are associated with male patients and aggressive tumor types.
- BECLIN expression correlates with advanced tumor stage but not with survival or relapse.
- ATG3 shows no significant clinicopathological associations in thymic epithelial tumors.

## Abstract

The present study investigated the role of autophagy, a cellular process, in thymic epithelial tumors (TETs) by analyzing four key proteins, BECLIN, p62, LC3b, and ATG3, using immunohistochemistry on 99 tumor samples. Higher BECLIN and p62 levels were linked to male patients and B3 thymomas/thymic carcinomas (TCs), while a positive correlation with advanced Masaoka–Koga stage was observed for BECLIN. Although LC3b showed a marginal increase in non-B3/TC TETs, ATG3 had no significant associations. While the study suggests that autophagy is active in more advanced or aggressive thymic cancers, these autophagy components did not significantly predict a patient’s overall survival or the likelihood of cancer relapse. Ultimately, the findings highlight autophagy as a potential area for future therapeutic targeting, though more research is needed to establish these proteins as reliable biomarkers.

Background: Autophagy, a self-destructive cellular mechanism with a paradoxical nature, plays a part in both tumor suppression and induction by providing cancer cells with metabolic substrates, resulting in cell proliferation and survival. In this study, we aim to investigate the clinical significance of four autophagy pathway components (BECLIN, p62/, LC3b, ATG3) in pathogenetic mechanisms of thymic epithelial tumors (TETs) with possible prognostic importance. Methods: Immunohistochemistry was used to evaluate the cytoplasmic expression of BECLIN, p62, LC3b, and ATG3 in tumor cells of 99 TETs, and possible correlations with clinicopathological parameters were examined. Results: Higher BECLIN and p62 expression was associated with male gender (p = 0.027 and p = 0.014, respectively). B3 thymomas and thymic carcinomas (TCs) displayed higher p62 expression (p = 0.019), while LC3b expression was marginally higher in non-B3/TC TETs (p = 0.098). A positive correlation between higher BECLIN expression and advanced Masaoka–Koga stage was also observed (p = 0.009). ATG3 was not associated with any of the investigated clinicopathological parameters (p > 0.05). There was also no significant correlation between any of the four examined molecules and overall survival or relapse. Conclusions: Our findings indicate autophagy activation in B3/TC and advanced Masaoka–Koga stage cases. Further studies are needed to explore the role of these autophagy related proteins as potential biomarkers and therapeutic targets in TETs.