Discovery of ferroptosis-inducing R4VP compounds for targeting aggressive cancers.

Aggressive and therapy-resistant cancers present a significant challenge to treatment and are associated with poor patients' survival. Identifying molecular pathways and compounds that target these pathways is critical for improving patient outcomes. RNF4, an E3 Ubiquitin ligase, is pivotal for tumorigenesis in part by stabilizing oncoproteins and its role in DNA repair, thereby enhancing cancer cell survival and driving tumorigenesis. Elevated RNF4 levels are associated with poor prognosis in patients with carcinomas, melanoma, and sarcoma. Here, we describe the design and development of R4VPs, dual degrader compounds connecting two E3 ubiquitin ligases; Von Hippel-Lindau protein (VHL) with RNF4. R4VPs promote RNF4 degradation and thereby reduce the levels of its stabilized phosphorylated oncoproteins, while concomitantly eliminating VHL. R4VPs selectively induce ferroptotic cell death in cancer cells, sparing non-tumorigenic and primary cells in part by binding and modifying the anti-ferroptotic selanoproteins GPX4. R4VPs-induced ferroptosis preferentially targeting cells harboring tumor-driving mutations in the EGFR pathway, whereas it does not affect PI3K-transformed cells. As a consequence, R4VPs effectively induce cell death in Receptor Tyrosine Kinase inhibitor-resistant melanoma and primary patient sarcoma cells. Our findings highlight the potential of selective ferroptosis inducers, such as R4VPs, as a therapeutic strategy for hard-to-treat cancers.