[Study of the genesis of bronchial epidermoid carcinoma: evolution or the expression of proteins, messenger RNAs and microRNAs at all stages of the process of carcinogenesis].

We characterized the successive and cumulative molecular modifications associated with transition in the histological stages of lung squamous carcinogenesis (normal epithelium from smokers, hyperplasia, metaplasia, mild, moderate and severe dysplasia, in situ carcinoma and invasive carcinoma) to improve our understanding of the mechanisms involved and identify new biomarkers for the early detection of lung squamous cell carcinoma. We employed immunohistochemistry, immunofluorescence, gene expression microarrays and quantitative RT-PCR to successively assess the expression of various proteins involved in cellular proliferation and apoptosis as well as messenger RNAs and microRNAs expression. Based on our data, we have improved the classification of bronchial preneoplastic lesions and furthered our understanding of the pathways involved in early lung carcinogenesis. The large number of biomarkers highlighted in these studies has opened two major and interesting perspectives: 1) the development of non invasive tests based on biomarkers for lung cancer detection at pre-invasive and early invasive stages and 2) new avenues of fundamental research whose goal is to understand the mechanisms underlying lung carcinogenesis.