Genome-wide CRISPR screen reveals CGS-15943 induced heme-dependent cell death mediated by aryl hydrocarbon receptor in lung cancer cells.

Induction of programmed cancer cell death by selective aryl hydrocarbon receptor (AHR) ligands represents a promising strategy for developing novel anticancer therapeutics. In this study, we characterized the anticancer activity and underlying mechanism of the selective AHR ligand CGS-15943 in lung cancer cells. CGS-15943 potently inhibited the growth of lung cancer cell lines expressing high levels of AHR, whereas CRISPR-mediated knockout of AHR in H460 and H69AR cells markedly rescued cells from CGS-15943-induced cell death, demonstrating an essential role for AHR. To identify additional mediators of this response, we performed a genome-wide CRISPR knockout screen, which revealed eight enzymes involved in the heme biosynthesis pathway, three heme-containing enzymes, as well as AHR and its transcriptional partner ARNT, as critical determinants of CGS-15943-induced cell death. Transcriptomic analyses further showed that CGS-15943 induced AHR-dependent transcriptional programs enriched for oxidative stress and oxidized phospholipid response pathways. Together, these findings identify key components of the AHR signaling network that regulate a programmed heme-dependent cell death pathway and establish CGS-15943 as a promising lead compound for targeting AHR-positive lung cancers.