Critical role for a high-plasticity cell state in lung cancer

Plasticity—the ability of cells to undergo phenotypic transitions—drives cancer progression and therapy resistance. Recent studies have suggested that plasticity in solid tumors is concentrated in a minority subset of cancer cells, yet functional studies interrogating this high plasticity cell state (HPCS) in situ are lacking. Here, we develop mouse models enabling detection, longitudinal lineage tracing, and ablation of the HPCS in autochthonous lung tumors in vivo. Lineage tracing reveals that the HPCS cells possess high capacity for cell state transitions, giving rise to both early neoplastic (differentiated) and progressed lung cancer cell states in situ. Longitudinal lineage tracing using secreted luciferases reveals HPCS-derived cells harbor high capacity for growth when compared to bulk cancer cells or another cancer cell state with features of differentiated lung epithelium. HPCS ablation in early neoplasias abrogates benign-to-malignant transition, whereas ablation in established tumors by suicide gene or CAR T cells robustly reduces tumor burden. We further demonstrate that the HPCS gives rise to therapy-resistant cell states, whereas HPCS ablation suppresses resistance to chemotherapy and oncoprotein-targeted therapy. Interestingly, an HPCS-like state is ubiquitous in regenerating epithelia and in carcinomas of multiple other tissues, revealing a convergence of plasticity programs. Our work establishes the HPCS as a critical hub enabling reciprocal transitions between cancer cell states. Targeting the HPCS in lung cancer and in other carcinomas may suppress cancer progression and eradicate treatment resistance.