Abstract 2910: Targeting thioredoxin reductase 1 (TrxR1) suppresses TAZ-driven glioblastoma progression

Abstract

Abstract Glioblastoma (GBM) is the most common and aggressive primary brain malignancy in adults. Poor outcomes for traditional treatments demand targeted therapies based on identified mechanisms that drive tumor development and sustain its malignancy. Molecular pathology studies have classified GBM into subtypes differing in treatment responses and survival rates. Among these subtypes, the mesenchymal (MES) group is associated with the worst prognosis. The Hippo pathway transcriptional co-activator with PDZ-binding motif (TAZ) is one of the three transcriptional regulators that drive the GBM MES gene expression program. Studies from our lab and others have previously shown that TAZ activation is able to promote GBM MES differentiation and progression. Therefore, finding vulnerabilities of TAZ-driven tumors may help to develop targeted therapeutic methods for MES GBM. In an orthotopic GBM mouse model, we found that TAZ-driven tumors show increased expression of thioredoxin reductase 1 (TrxR1), which is responsible for catalyzing the reduction of thioredoxin and maintaining the cellular redox balance. In searching for the cause of increased expression of TrxR1, we found that glucose deprivation can induce TrxR1 expression, suggesting TrxR1 may be an adaptive mechanism for tumor cells to survive in glucose deprivation conditions. Indeed, either depleting TrxR1 genetically or inhibiting TrxR1 pharmacologically can promote tumor cell death under glucose deprivation. Furthermore, knockout TrxR1 in a TAZ-driven mouse GBM model significantly decelerated tumor progression. Collectively, our studies revealed that inhibition of the Trx redox system under glucose deprivation conditions leads to a synergistic cell death induction in GBM cells, therefore making targeting TrxR1 a potential therapeutic strategy for TAZ-driven MES GBM. Citation Format: Miaolu Tang, Kaitlyn Dirks, Soo Yeon Kim, Jessica Thorpe, Wei Li. Targeting thioredoxin reductase 1 (TrxR1) suppresses TAZ-driven glioblastoma progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2910.