CEBPB is required for NRF2-mediated drug resistance in NRF2-activated non-small cell lung cancer cells

Abstract NRF2 is a transcription activator that plays a key role in cytoprotection against oxidative stress. Although increased NRF2 activity is principally beneficial for our health, NRF2 activation in cancer cells is detrimental, as it drives their malignant progression. We previously found that CCAAT/enhancer-binding protein B (CEBPB) cooperates with NRF2 in NRF2-activated lung cancer and enhances tumour-initiating activity by promoting NOTCH3 expression. However, the general contribution of CEBPB in lung cancer is rather controversial, probably because the role of CEBPB depends on cooperating transcription factors in each cellular context. To understand how NRF2 shapes the function of CEBPB in NRF2-activated lung cancers and its biological consequence, we comprehensively explored NRF2-CEBPB–coregulated genes and found that genes involved in drug metabolism and detoxification were characteristically enriched. Indeed, CEBPB and NRF2 cooperatively contribute to the drug resistance. We also found that CEBPB is directly regulated by NRF2, which is likely to be advantageous for the coexpression and cooperative function of NRF2 and CEBPB. These results suggest that drug resistance of NRF2-activated lung cancers is achieved by the cooperative function of NRF2 and CEBPB.