PATH-21. GPX4 IS CRUCIALLY IMPLICATED IN THE PATHOBIOLOGY OF GLIOBLASTOMA AND A PUTATIVE ACTIONABLE TARGET

Abstract

Abstract BACKGROUND Glioblastoma(GBM) is the most common malignant primary brain tumor with a dismal prognosis. Glutathione-mediated inhibition of the ferroptotic form of cell death is crucially implicated in various malignancies, which is principally regulated by glutathione peroxidase 4 (GPX4). However, there is limited data on GBM. The present study evaluated the expression of GPX4 in GBM and its implications in tumor biology, clinical outcome, and therapeutic potentials. METHODS The mRNA and protein expression was assessed by qRT-PCR and immunohistochemistry, respectively, in 75 cases of adult hemispheric GBMs (IDH wild type). For comparison, 21 lower-grade astrocytomas (IDH-mutant, grade-2/3) [LGA] and 20 cases were also evaluated. In-vitro analysis was performed on U87MG and LN229 glioma cell line. RESULTS The mRNA expression of GPX-4 was significantly higher in GBM than LGA, and normal brain (NB) [p-values 0.028, and 0.001, respectively]. Normal brain cases were negative for GPX4. Almost half of the GBMs (49.3%) showed strong immunoreactivity, which was higher than LGAs (23.8%) [p-value -0.04]. Inhibition of GPX-4 in-vitro by 1S-RSL3 & FIN56 was associated with decreased cell survival, proliferation, migration, invasion, and increased cell death. GPX-4 expression was not significantly associated with overall survival in GBM. CONCLUSION GPX-4 is crucial for the tumor cells' survival and aggressive biological behavior. Considering its immune-positivity only in the neoplastic cell and strong positivity in GBM it may be a useful adjunct to the diagnosis. The present study emphasized its role as a potential therapeutic target in the form of 1S-RSL3 & FIN56.