O4 Modelling and treatment of squamous cell carcinoma in recessive dystrophic epidermolysis bullosa
Prerna Kadam, Max Bone, Lynn McGarry, Ryan Corbyn, Laura Galbraith, Leo Carlin, Karen Blyth, Gareth Inman, John PritchardAbstract
Introduction and aims
Recessive dystrophic epidermolysis bullosa (RDEB) is a rare condition caused by mutations in the gene for type VII collagen (C7). Loss of C7 leads to fragile skin that blisters and wounds easily and patients with severe forms of RDEB are at high risk of developing aggressive, and often fatal, cutaneous squamous cell carcinoma (cSCC). Currently, there are no approved treatments for RDEB-cSCC. This is due, in part, to an incomplete understanding of disease biology and potential therapeutic vulnerabilities and limited preclinical models of disease. To address this, we are integrating gene expression profiling data, identifying existing drugs that might be effective against RDEB-cSCC and developing xenograft models.
Methods
We screened 3135 US Food and Drug Administration (FDA)-approved drugs on patient-derived RDEB cancer cell lines (PDCLs) and performed an integrated analysis of RNA sequencing data. We have also developed four PDCL in vivo xenograft mouse models.
Results
Overall, 163 drugs were found to reduce cell growth by at least 30%. Analysis showed that several of these drugs targeted pathways involved in cancer growth and survival, such as phosphoinositide 3-kinase-Akt/mechanistic target of rapamycin, MEK/mitogen-activated protein kinase, Janus kinase/signal transducer and activator of transcription, and histone deacetylase. In parallel, RNA sequencing revealed that these pathways were unusually active in patients’ tumours. Several of our lead candidate drugs that target these pathways were found to slow tumour cell growth and/or trigger cell death. We have developed four PDCL xenograft models that show different growth kinetics in vivo that can be used for further drug testing.
Conclusions
We have identified key pathways that are active in RDEB-cSCC, FDA approved drugs that target them and developed four PDCL xenograft models.