Bladder cancer is among the most common cancers worldwide (4th in men). It is responsible for high patient morbidity and displays rapid recurrence and progression. Lack of sensitivity of gold standard techniques (white light cystoscopy, voided urine cytology) means many early treatable cases are missed. The result is a large number of advanced cases of bladder cancer which require extensive treatment and monitoring. For this reason, bladder cancer is the single most expensive cancer to treat on a per patient basis. In recent years, autofluorescence spectroscopy has begun to shed light into disease research. Of particular interest in cancer research are the fluorescent metabolic cofactors NADH and FAD. Early in tumour development, cancer cells often undergo a metabolic shift (the Warburg effect) resulting in increased NADH. The ratio of NADH to FAD (“redox ratio”) can therefore be used as an indicator of the metabolic status of cells. Redox ratio measurements have been used to differentiate between healthy and cancer breast cells and to monitor cellular responses to therapies. Here, we have demonstrated, using healthy and bladder cancer cell lines, a statistically significant difference in the redox ratio of bladder cancer cells, indicative of a metabolic shift. To do this we customised a standard flow cytometer to excite and record fluorescence specifically from NADH and FAD, along with a method for automatically calculating the redox ratio of individual cells within large populations. These results could inform the design of novel probes and screening systems for the early detection of bladder cancer.

Date Published: 26 February 2015
PDF: 6 pages
Proc. SPIE 9303, Photonic Therapeutics and Diagnostics XI, 93030T (26 February 2015); doi: 10.1117/12.2077218

Published in SPIE Proceedings Vol. 9303:
Photonic Therapeutics and Diagnostics XI
Hyun Wook Kang; Brian J. F. Wong M.D.; Melissa C. Skala; Bernard Choi; Guillermo J. Tearney M.D.; Andreas Mandelis; Nikiforos Kollias; Kenton W. Gregory M.D.; Mark W. Dewhirst D.V.M.; Justus F. Ilgner M.D.; Alfred Nuttal; Haishan Zeng; Laura Marcu; Claus-Peter Richter, Editor(s)