AbstractBladder cancer is among the most common cancers in the UK, responsible for significant patient morbidity. Current techniques for detection suffer from low sensitivity, particularly for early stage disease, therefore new techniques are urgently sought.
Among the suggested techniques to augment bladder cancer detection is the use of autofluorescence spectroscopy. Autofluorescence arises from a number of molecules in human tissue, giving a wealth of structural and metabolic information. Autofluorescence spectroscopy has previously been applied to the detection of a wide range of cancers, however clinical implementation of the technique to bladder cancer diagnosis is inhibited by a poor understanding of the contributions of individual fluorophores to autofluorescence. I sought primarily to use the multi-functional laser based diagnostic system “LAKK-M” to study the autofluorescence profiles of bladder cancer at the cell and tissue level, with the aim of developing a better understanding of bladder autofluorescence characteristics in health and disease. The significant findings of this research are threefold:
1. Autofluorescence flow cytometry of cell optical redox ratio reveals metabolic abnormalities in bladder cancer cells, specifically a glycolytic switch in bladder cancer cells culminating in an increased optical redox (NADH/flavin, ex360em425-475/ex488em515/545) ratio relative to healthy bladder cells.
2. Lab grown bladder cancer organoids show progressive changes in autofluorescence ratios relative to control samples – specifically reductions in the NADH/flavin (ex365em490/ex365em550), elastin/NADH (ex365em450/ex365em490) and elastin/flavin ratio (ex365em450/ex365em550), suggestive of structural and metabolic changes in developing cancer.
3. Analysis of human bladder tissue reveals significant differences in key fluorophores and diagnostic ratios between healthy and cancer tissue, amounting to increased porphyrin fluorescence and a decreased optical redox ratio (ex365em490/ex365em550) in cancer tissue compared to healthy control.
These findings better inform our understanding of the autofluorescence properties of the bladder in health and disease at both the cell and tissue level, contributing to future development of diagnostic techniques. Additionally, in this thesis, I discuss the diagnostic worth of collagen analysis in bladder cancer using second harmonic generation imaging, the application of bladder tissue computer simulation to better elucidate fluorophore properties, and progress in novel laser therapy techniques for bladder cancer. The ultimate goal of this research is the development of a combined laser-based system for bladder cancer diagnosis and therapy.
|Date of Award||2016|
|Sponsors||Engineering and Physical Sciences Research Council|
|Supervisor||Ghulam Nabi (Supervisor) & David McGloin (Supervisor)|