LAUSR

Inhibition of the GPX4 enzyme leads to the rapid accumulation of toxic lipid peroxides and cell death through a process known as ferroptosis. This mechanism has recently garnered significant attention in the field of oncology because many difficult-to-treat tumor types are particularly susceptible to this non-canonical form of cell death. However, robust biomarkers that predict sensitivity to ferroptosis are needed to help select well-defined tumor subtypes and patient segments that are likely to respond to GPX4-targeting. Our nascent RNA platform measures the active transcription of not only protein-coding transcripts, but also transcripts initiating from enhancer regions (enhancer RNAs) critical for defining cell type. We reasoned that these data could afford the unique opportunity to identify non-coding transcripts that could serve as novel biomarkers of sensitivity to ferroptosis. We recently discovered a potent and selective GPX4 inhibitor and profiled the compound for its ability to induce ferroptosis across a diverse group of cancer cell types. We chose several of the most sensitive and resistant cell lines for further examination using our nascent RNA platform and identified novel relationships between sensitivity to ferroptosis and cell-specific enhancer RNA profiles. Importantly, enhancer RNA profiles were more effective at stratifying sensitive and resistant cell lines than protein-coding gene expression. Using enhancer RNA expression profiles as biomarkers of drug sensitivity represents a novel strategy that could ultimately improve our ability to select patient cohorts more likely to benefit from emerging drug candidates and established therapeutics. Citation Format: Timothy Read, David Simpson, Jenna Rimel, Christy Rhine, Casey Pham, Cole Liechty, Eric Martin, Joey Azofeifa. Enhancer RNA profiles predict sensitivity to a novel GPX4 inhibitor. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4913.