The aim of our work is to develop new technologies to apply to the treatment of cancer, based mainly on genotypic changes in tumour cells.
Most proteins involved in tumourigenesis are found inside the cell (in the cytoplasm or the nucleus) and most often are not enzymes per se but rather molecules, such as transcription factors, that are involved in protein complexes by protein-protein interactions. One of our primary aims is to develop molecules that are able to interfere with protein-protein interactions in cancer cells (and indeed in other cell types of clinical indications where appropriate). A central facet of our work is the use of antibody fragments, mainly single variable region domains, which are able to fold on expression in the reducing environment of the cell, and interact with antigenic sites on target proteins.
The strategy of our work is firstly target identification followed by development of antibody single domain fragments as drug surrogates to interfere with the intracellular function of the target for the purposes of target validation. Following target validation, the next step in the strategy pipeline is to solve the crystal structure of the target molecule and the antibody complex in order to determine the residues on the antibody important for the binding activity. This structure-function relationship allows key anchor residues to be identified in the antibody fragment variable region to form a template for small molecule or peptide discovery. The development of peptides and small molecule emulators of the antibody binding site is underway for single domain antibodies binding to mutant RAS (present in many human cancers) and LMO2 protein (active in T cell acute leukaemia).
The antibody fragments are critical laboratory reagents that are valuable in their own right for target validation and biological studies. As they are proteins (~120 amino acids), they will not naturally enter cells as drugs might. There may be technologies that can be implemented for delivery of that these antibody fragments (which we term macrodrugs since they are macromolecular drug-like entities) or vectors to express them in target cells. Methods involving nanoparticle delivery or whole antibody-coupled delivery are being investigated.
We are also investigating cell surface proteins in leukaemia, sarcoma and epithelial cancers using NGS RNA-sequencing as a surrogate for the proteome. The development of overt cancer after a chromosomal translocation initiating event occurs in stages as depicted in the diagram below. The overt cancer phase currently offers a therapeutic window but the pre-symptomatic phase is a key stage if the cells and the molecular changes can be identified.
We are interested in defining the cell surface proteins for the various stages in cancer development from initiation through to overt cancer, and in the case of epithelial cancers, to disseminated disease as depicted below. This work will identify new biomarkers, new therapeutic targets and cell surface molecules for guiding novel therapies to and into target cells in vivo (for instance, macrodrugs such as antibody fragments in our intracellular immunotherapy programme).
University of Oxford: MRC Human Immunology Unit (Graham Ogg, Alison Simmons). Oncology (Walter Bodmer). Chemistry (Angela Russell). Institute of Biomedical Engineering (Robin Cleveland). STRUBI, Division of Structural Biology (Yvonne Jones, David Stuart).
Aberystwyth University, Institute of Biological, Environmental and Rural Sciences: Narcis Fernandez-Fuentes
New York University: Andrew Hamilton
Research Complex at Harwell, Rutherford Appleton Laboratory: Simon Phillips, Steve Carr
Medical Research Council