Lung squamous cell carcinoma (LUSC) arises from the accumulation of genomic alterations in basal cells, the resident stem cells in the bronchial epithelium. Regardless of a complex pattern of driver genes and extensive heterogeneity, LUSC tumours present important commonalities such as frequent inactivation of TP53 and CDKN2A, genetic alterations recurrently targeting important pathways and repetitive temporal patterns in which genetic alterations occur during tumour evolution. This new perspective into LUSC genetics can be exploited to build more accurate LUSC models that reflect patient heterogeneity and the developmental stages of the disease. Using cultured human basal cells (HBCs) constitutes an excellent system to develop these comprehensive models of LUSC and replace large cohorts of mouse models in a wide range of basic and translational research areas. In this project, we will recapitulate the evolutionary history of LUSC in HBCs in order to build a new human model of LUSC progression, thereby providing an alternative in vitro model of this disease.
To develop this model, we will generate genetically-engineered HBCs harbouring cumulative genetic alterations in a sequential manner, mimicking the evolutionary stages of LUSC. The selection of genetic alterations will be based on high frequency of mutations in patients, alterations targeting pathways recurrently altered in LUSC and drivers of intratumour heterogeneity. To validate the model, we will analyse the cumulative role of the genetic alterations in driving the landmarks of LUSC progression, including invasiveness, epithelial alterations, proliferation, gene-expression changes, genome instability and secretion of immuno-modulatory factors. This model will enable us to replace mouse models to investigate clinically relevant aspects of LUSC biology such as precancerous stages and cooperation of somatic alterations, and will reflect better the human biology and heterogeneity of LUSC.