# Expressions of the satellite repeat HSAT5 and transposable elements are implicated in disease progression and survival in glioma

## TL;DR

This study explores how satellite repeats and transposable elements in the genome are linked to glioma progression and patient survival.

## Contribution

The study is the first to show that repeat/transposable element expression correlates with glioma progression and survival.

## Key findings

- 16 transposable elements were associated with slower disease progression in low-grade glioma patients.
- HSAT5 satellite repeat and 22 transposons were linked to shorter survival in high-grade glioma patients.
- HSAT5 co-occurred with genes related to chromosome segregation and nuclear division, suggesting a role in glioma pathogenesis.

## Abstract

The glioma genome encompasses a complex array of dysregulatory events, presenting a formidable challenge in managing this devastating disease. Despite the widespread distribution of repeat and transposable elements across the human genome, their involvement in glioma’s molecular pathology and patient survival remains largely unexplored. In this study, we aimed to characterize the links between the expressions of repeat/transposable elements with disease progression and survival in glioma patients. Hence, we analyzed the expression levels of satellite repeats and transposons along with genes in low-grade glioma (LGG) and high-grade glioma (HGG). Endogenous transposable elements LTR5 and HERV_a-int exhibited higher expression in HGG patients, along with immune response-related genes. Altogether, 16 transposable elements were associated with slower progression of disease in LGG patients. Conversely, 22 transposons and the HSAT5 satellite repeat were linked to a shorter event-free survival in HGG patients. Intriguingly, our weighted gene coexpression network analysis (WGCNA) disclosed that the HSAT5 satellite repeat resided in the same module network with genes implicated in chromosome segregation and nuclear division; potentially hinting at its contribution to disease pathogenesis. Collectively, we report for the first time that repeat and/or transposon expression could be related to disease progression and survival in glioma. The expressions of these elements seem to exert a protective effect during LGG-to-HGG progression, whereas they could have a detrimental impact once HGG is established. The results presented herein could serve as a foundation for further experimental work aimed at elucidating the molecular regulation of glioma genome.