IntroductionLung squamous cell carcinoma (LSCC) is a lethal disease accounting for 30% of all lung cancer cases. Currently, there are no effective treatments: patients are treated with a combination of surgery, chemotherapy and radiotherapy. So far numerous high-throughput screenings have been carried out in order to identify the representative mutations of this tumour. Their contribution is precious but remains descriptive.Material and methodsMice were engineered by using Flp-Recombinase mediated cassette exchange technology in ES cells. Mutations were activated by Intratracheal injection of adenoviruses carrying Cre recombinase under different promoters.Genome profiling and histological analysis were performed on lung isolated from mice that showed signs of distress due to tumour development.Results and discussionsWe published that mice carrying SOX2 over-expression combined with PTEN and CDKN2AB loss (hereafter SOX2PC) developed central and peripheral LSCC according to the targeted cell-of-origin, fully mimicking the human counterpart.To examine gene contribution, we uncoupled the inactivation of tumour suppressor genes and found that mice defective either of PTEN or CDKN2AB in combination with SOX2 over-expression, only showed epithelial hyperplasia, indicating that the combination is necessary for the tumour to progress.In order to use SOX2PC autochthonous model for intervention studies, we attempted at reducing tumour latency by combining other oncogenes with SOX2 over-expression. Our data pointed at FGFR1 and NFE2L2 as candidate drivers of human LSCC. Surprisingly, FGFR1-SOX2PC mice were resistant to tumour formation, indicating that FGFR1 downstream pathways may be detrimental to squamous differentiation. However, NFE2L2, a transcription factor involved in the anti-oxidant pathway and found altered in 12% of human LSCC cases, strongly enhanced tumour progression without affecting the overall tumour morphology. Most importantly, in both NFE2L2-SOX2PC and SOX2PC mice, we observed a highly immunogenic microenvironment, as reported for human patients, with high level of PD-L1 and extensive immune infiltrations of leukocytes mostly of myeloid lineage.ConclusionOur data show that neoplastic squamous differentiation is strongly associated to the oncogenic activation of SOX2. Concomitant activation of the anti-oxidant pathway accelerates tumour progression, making NFE2L2-SOX2PC autochthonous model, with its characteristic immunophenotype (massive myeloid immune infiltrations) suitable for a diversity of intervention studies.