EPCO-33. DIFFERENTIAL EXPRESSION OF AN ENDOGENOUS RETROVIRAL ELEMENT [HERV-K(HML-6)] IS ASSOCIATED WITH REDUCED SURVIVAL IN GLIOBLASTOMA PATIENTS

Abstract INTRODUCTION Comprising approximately 8% of our genome, Human Endogenous RetroViruses (HERVs) represent a class germline retroviral infections that are regulated through epigenetic modifications. In cancer cells, which often have dysregulation, HERVs been implicated as potential oncogenic drivers. However, their role in gliomas is not known.Given the link between HERV expression cell lines and distinct dysregulation gliomas, we utilized tailored bioinformatic pipeline to characterize validate glioma retrotranscriptome correlate with locus-specific modifications.Method:A custom workflow was used quantify interest. Cell-line methylation quantified using script. We generated primers specific for endogenous Mouse mammary tumor (MMTV)-Like virus 6 (HML-6). Visualization RNA transcripts performed RNA-scope. Clinical data obtained R package, TCGABiolinks. RESULTS The A172 line had significantly higher mean overall relative M059J H4 (p< 0.0001 both). cells lower number CpG islands There significant inverse correlation beta value FC (R=-0.57, p=0.01). qPCR confirmed robust HML-6 locus culture neurospheres. Elevated ERVK3-1 associated reduced survival among IDHwt GBM patients (18.3 vs. 15.1 months, p=0.039). This preserved IDH mutant (IDHm) well (17.9 months 14.0 p=0.0088). CONCLUSION correlates loss DNA at loci. overexpressed highly invasive glioblastoma patient-derived demonstrated detriment elevated product, ERVK3-1.