Expression analyses of inducible c-Fos expressing kerationcytes

Expression analyses comparing c-Fos expressing keratinocytes vs non-expressing controls. Skin squamous cell carcinomas (SCCs) are the second most prevalent skin cancers. Chronic skin inflammation has been associated with the development of SCCs, but the contribution of skin inflammation to SCC development remains largely unknown. In this study we demonstrate that inducible expression of c-fos in the epidermis of adult mice is sufficient to promote inflammation-mediated epidermal hyperplasia leading to the development of pre-neoplastic lesions. Interestingly, c-Fos transcriptionally controls mmp10 and s100a7a15 expression in keratinocytes subsequently leading to CD4 T cell recruitment to the skin, thereby promoting epidermal hyperplasia. Combining inducible c-fos expression in the epidermis with a single dose of the carcinogen 7,12-Dimethylbenz(a)anthracene (DMBA) leads to the development of highly invasive SCCs, which are prevented by using the anti-inflammatory drug Sulindac. Moreover, human SCCs display a correlation between c-FOS expression and elevated levels of MMP10 and S100A15 proteins as well as CD4 T cell infiltration. Our studies demonstrate a bidirectional crosstalk between pre-malignant keratinocytes and infiltrating CD4 T cells in SCC development. Therefore, targeting inflammation along with the newly identified targets, such as MMP10 and S100A15, represent promising therapeutic strategies to treat SCCs. 5 different time points measured in triplicate comparing Dox-treated vs untreated c-FostetON keratinocytes