Abstract 4430: Metabolic reprogramming by ASPSCR1::TFE3 and VCP

Abstract

Abstract Alveolar soft part sarcoma (ASPS) is a lethal soft tissue malignancy typically incident among adolescents and young adults, distinguished by the t(X;17) ASPSCR1::TFE3 fusion gene (AT3). Conventional chemotherapy has shown limited efficacy against ASPS, necessitating exploration of alternative strategies. Previous investigations have shown the pivotal role of the fusion gene in sarcomagenesis in mice, particularly in lactate-rich environments. This study aims to elucidate the metabolic alterations actuated by the AT3 fusion gene, both in vitro and in vivo. To model in vitro metabolic profiles, ASPS (ASPS-1) and renal cell carcinoma (FU-UR1) cell lines, each expressing AT3, were employed. Utilizing siRNA-mediated gene silencing, AT3 and VCP, a cofactor, were targeted in vitro. Metabolomic profiling through GC-MS analyzed the impact of depletion of AT3 or its transcriptional co-factor, VCP. C13-labeled metabolites were introduced and traced in vitro and in vivo to enhance comprehension of carbon utilization in aerobic respiration. While metabolic activity and O2 consumption differed between cell lines, inhibition of AT3 and VCP led to similar metabolite alterations. Significant changes in amino acid metabolism, notably glutamate, aspartate, and alanine were observed in both cell lines. There was notable diversion of glucose carbon utilization away from typical entry into the tricarboxylic acid (TCA) cycle, with minimal carbon incorporation beyond alpha-ketoglutarate. Despite prior data indicating heightened mitophagy activity in AT3 driven cells, inhibition of lysosomal activity did not yield significant changes in cellular respiration or O2 consumption. Citation Format: Rahi Patel, Amir Pozner, Kyle Dunlap, Lara Carroll, Jeff Brown, Greg Ducker, Kevin Jones. Metabolic reprogramming by ASPSCR1::TFE3 and VCP [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 4430.