Supervisor: Kevin Brindle
Mutimodality imaging of early response to treatment in murine breast cancer models
This PhD project will further develop molecular imaging methods established in Professor Brindle's lab for assessment of early drug response in cancer. The work will focus on breast cancer and will predominantly use two different approaches. Read more'
The first approach involves imaging of apoptosis using a variety of agents and imaging methods both in vitro and in vivo. One of the main agents of interest is the C2A fragment of synaptotagmin which will be used with a fluorophore for in vitro work. It will also be used with radioactive labels for use with in vivo PET and SPECT imaging.
The second approach is imaging of intracellular biochemical changes, such as pH, using hyperpolarised 13C with MRI for both in vitro and in vivo studies.
The aim of the project is to develop these methods so they can be applied to predict response to treatment in cancer after just a single dose.
Supervisor: Paul Lehner
Identification of the cellular components involved in the quality control and regulation of MHC class I molecules
The aim of this project is to identify the cellular components involved in the quality control and regulation of Major Histocompatibility Complex (MHC) class I molecules.
MHC class I plays a critical role in immune surveillance for viral infections and tumours via presentation of intracellular protein-derived peptides to cytotoxic T lymphocytes. MHC class I molecules are heterotrimers consisting of a transmembrane heavy chain, '2-microglobulin and a peptide ligand. The folding and assembly of these complexes is subject to stringent quality control within the endoplasmic reticulum (ER). However, accumulation of misfolded MHC class I molecules is observed in a variety of pathological settings, for example aggregation of HLA-B27 in ankylosing spondylitis. In addition, many viruses exploit these cellular quality control mechanisms in order to down-regulate MHC class I expression at the cell surface and thus evade the host immune system. Read more..
Under normal circumstances, class I molecules which fail to achieve their native conformation due to protein misfolding, or the absence of bound peptide, are targeted for elimination via the ER-associated degradation (ERAD) pathway. This requires recognition by the ERAD machinery, ubiquitination and retrograde translocation from the ER to the cytosol for proteasome-mediated degradation. The critical enzyme in this process is the ubiquitin E3 ligase which confers substrate specificity.
An initial flow cytometry based 'loss of function' siRNA screen has identified an E3 ligase required for endogenous MHC class I regulation and has highlighted other potential components of the MHC class I ERAD pathway. Further aims of this project include biochemical characterisation of these components, elucidation of their mode of action and analysis of their potential role in disease.
Supervisor: Austin Smith
Self renewal and cell fate mechanisms in human neural stem cells
Self-renewal is the process by which a stem cell divides to repeatedly generate identical copies of itself. Cancer is thought to arise from mutations that inappropriately activate self-renewal programs. Despite the importance of neural stem cell self-renewal, we are only beginning to understand how it is regulated. Read more..
The primary goal of my research is to use pluripotent stem cell-derived neuro-epithelial stem (NES) cells as an in vitro model system to uncover the mechanisms of self-renewal and cell fate specification of primitive neuroepithelial cells. I will characterise the gene expression profile of human NES cells and their differentiating progeny, and relate this to genes that regulate the undifferentiated state and proliferation of neural stem cells in other organisms as well as genes implicated in the formation of primitive neuroectodermal tumours (PNETs).
I will test the role of candidate transcriptional regulators by developing a robust, efficient and reliable assay of differentiating NES cells using RNA interference (RNAi) and gene overexpression techniques. Ultimately, my goal is to determine how the inappropriate activation of self-renewal programs in NES cells may relate to the formation of PNETs, a heterogeneous group of tumours occurring in children that are histologically composed of undifferentiated or poorly-differentiated neuroepithelial cells. I will genetically manipulate NES cells to over-activate self-renewal programs and transplant these cells into immunodeficient mouse brain to examine whether this recapitulates the development of PNETs.
In parallel, I will attempt to isolate and characterise NES cells from human foetal brain in order to investigate the normal counterpart of the in vitro iPS-derived NES cells. I will also endeavour to derive tumour initiating stem cell lines from PNETs to provide a better understanding of how this aggressive tumour may develop.