Project 466615

Head and Neck Squamous Cell Carcinoma (HNSCC) is one of the deadliest and most prevalent cancers with rising incidence. The treatment options are non-selective and associated with toxicities and other adverse effects, thus highlighting the need for novel therapeutic strategies. CRISPR screening has been widely used to identify genetic vulnerabilities in cancer cell lines. However, these in vitro models lack the tumour microenvironment and do not fully capture the intricate biology of tumours. To address this issue, our group has established HNSCC mouse models that integrate multiplexed in vivo CRISPR/Cas9 mutagenesis to test hundreds of genes in a single mouse within a couple of weeks. To inactivate candidate cancer genes in the oral cavity and skin of mice, highly concentrated CRISPR/Cas9 lentiviruses are being delivered to the single-layer surface ectoderm of living mouse embryos via ultrasound-guided microinjections. Our first in vivo CRISPR screen, performed directly in the epithelium of tumour-prone mice, identified Insulin-like growth factor binding protein 3 (IGFBP3) as a top hit essential for the selective proliferation of transformed epithelial cells. In clinical datasets, IGFBP3 is amplified/gained in ~ 39% of HNSCC patients, and increased mRNA levels correlate with poorer survival. My project aims to combine in vivo CRISPR gene editing in mouse models of HNSCC and functional genomic experimentation in patient-derived HNSCC xenografts to further characterize the oncogenic function of IGFBP3 in HNSCC and delineate its molecular mechanism of action. Successful completion of this project will contribute to novel targeted therapeutics of HNSCC and highlight the potential of in vivo drop-out screens to detect novel, biologically relevant cancer drug targets.