Shinkichi Takamori, Naoki Haratake, Atrayee Bhattacharya, Hiroki Ozawa, Keisuke Shigeta, Mai Onishi, Kentaro Nonaka, Takefumi Komiya, Hiroki Komatsuda, Tomoyoshi Takenaka, Tomoharu Yoshizumi, Chendi Li, Jiehui Deng, Aaron N. Hata, Mark D. Long, Mark D. Long, Donald Küfe
Treatment of NSCLC KRAS G12C mutant tumors with the allele-selective sotorasib and adagrasib inhibitors is invariably associated with acquired resistance. The MUC1-encoded oncogenic M1C protein is necessary for self-renewal of NSCLC KRAS mutant cells. We report that treatment of NSCLC KRAS G12C cells with sotorasib induces M1C expression by a STAT1-dependent pathway. In turn, M1C drives the sotorasib resistant phenotype by NF-κB-mediated induction of the epithelial-mesenchymal transition (EMT) and a mucinous gene program. Targeting M1C→NF-κB signaling (i) suppresses EMT and mucin genes, and (ii) reverses sotorasib resistance. Of translational relevance, treatment with a M1C antibody-drug conjugate (ADC) is effective against two sotorasib-resistant NSCLC KRAS G12C cell lines and two patient-derived tumor xenograft models. Analysis of patients with NSCLC KRAS G12C tumors treated with sotorasib/adagrasib and overexpressing MUC1 associates with decreases in overall survival. These findings identify M1C as a key effector of sotorasib resistance and as a target for treatment of patients with refractory NSCLC KRAS G12C mutant tumors.