Abstract LB169: Using a global reporter on transcript abundance to identify a selective inhibitor of Nrf2 signaling in KEAP1-mutant non small cell lung cancer

Abstract Loss-of-function mutations in Kelch-like ECH-associated protein 1 (KEAP1) are common in non-small cell lung cancer (NSLC) and result in particularly poor prognosis. Such mutations activate the transcription factor Nrf2, leading to aberrant expression of chemoprotective genes and rendering cells resistant to chemotherapy. We used our chemo-transcriptomic platform, termed GRETA, for Global Reporter on Transcript Abundance, to identify compounds that inhibit Nrf2 transcription factor activity in KEAP1-mutant NSCLC cell lines. After defining the transcriptomic signature imparted by constitutive activation of Nrf2 in a KEAP1 KO NCI-H1975 cell line, we generated over 10, 000 transcriptomes to identify compounds that dampen the Nrf2-overactive transcriptional signature. One such compound, ARP-4316, displays selectivity for KEAP1-mutant cell lines, reduces nuclear Nrf2 protein levels, and reduces Nrf2 transcriptional activity in an ARE reporter assay. Furthermore, ARP-4316 synergizes with 5-fluorouracil in two KEAP1-mutant cell models, A549 and NCI-H2122, suggesting that ARP-4316 may sensitize KEAP1 mutant cell lines to chemotherapy by inhibiting Nrf2 transcriptional activity. Efforts to identify the cellular target and mechanism of action of ARP-4316 are underway. Citation Format: Timothy J. Read, Leah Damon, Reo Yoo, Carter Grochala, Cole Liechty, Christy Rhine, Jenna Rimel, David Simpson, Riley Lundblad, Casey Pham, Richard Steel, Joey Azofeifa. Using a global reporter on transcript abundance to identify a selective inhibitor of Nrf2 signaling in KEAP1-mutant non small cell lung cancer abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (7Suppl): Abstract nr LB169.