Work

PHF10 is a Novel Substrate of Keap1 to Protect Non-Small-Cell Lung Cancer (NSCLC) Cells Against Oxidative Stress and Confer Ferroptosis Resistance

Year: 2025

Type: article

Abstract: Purpose: Keap1 mutations mainly caused NRF2-dependent anti-oxidative stress responses, yet whether there are other downstream substrates and pathways remains unknown. This study aimed to uncover the role of Keap1 mutations in regulating PHF10-NRF2 axis in NSCLC and ferroptosis evasion. Materials and Methods: Tandem affinity purification with mass spectrometry was used to screen peptides. Co-IP and ubiquitination assays were used to confirm the Keap1-PHF10 axis. A series of analyses in cell lines, patient samples, and xenograft models were conducted to uncover the functional dependency between Keap1 and NRF2. Transmission electron microscope was used to detect mitochondrion swelling under ferroptosis. Results: Here, we reported that Keap1 binds and promotes polyubiquitination and degradation of PHF10, a subunit of the PBAF complex. NSCLC-associated Keap1 mutations are incapable of degrading PHF10, and thus induces PHF10 proteins stability. PHF10 ablation shows synthetic lethality in Keap1-deficient NSCLC cells. Mechanistically, PHF10 interacts with NRF2 to activate its downstream targets and enhance the NRF2-dependent anti-oxidative stress capacity in NSCLC. PHF10 recruits SMARCA2, one core cBAF subunit, to increase chromatin accessibility in NRF2-binding transcriptional regions. Cancer-associated Keap1 mutants confer resistance to ROS-induced cell death via accumulating PHF10-SMARCA2 complex. Increased PHF10 further induced ferroptosis resistance in Keap1-deficient NSCLC. Lastly, we utilized one small molecule inhibitor, SMARCA2-IN-8, to inhibit progression of Keap1-deficient NSCLC murine models. Conclusion: Together, our study highlight the synthetic lethal relationship between Keap1 and PHF10, and provide targeting PHF10-SMARCA2 complex as an effective option to hit Keap1-deficient NSCLC.

Source: Cancer Research and Treatment

DOI: 10.4143/crt.2025.635