Detection of urinary bladder cancer cells using redox ratio and double excitation wavelengths autofluorescence

Abstract

The optical redox ratio as a measure of cellular metabolism is determined by an altered ratio between endogenous fluorophores NADH and flavin adenine dinucleotide (FAD). Although reported for other cancer sites, differences in optical redox ratio between cancerous and normal urothelial cells have not previously been reported. Here, we report a method for the detection of cellular metabolic states using flow cytometry based on autofluorescence, and a statistically significant increase in the redox ratio of bladder cancer cells compared to healthy controls. Urinary bladder cancer and normal healthy urothelial cell lines were cultured and redox overview was assessed using flow cytometry. Further localisation of fluorescence in the same cells was carried out using confocal microscopy. Multiple experiments show correlation between cell type and redox ratio, clearly differentiating between healthy cells and cancer cells. Based on our preliminary results, therefore, we believe that this data contributes to current understanding of bladder tissue fluorescence and can inform the design of endoscopic probes. This approach also has significant potential as a diagnostic tool for discrimination of cancer cells among shed urothelial cells in voided urine, and could lay the groundwork for an automated system for population screening for bladder cancer.

Label‐free imaging and spectroscopy for early detection of cervical cancer

“…Therefore, the majority of cancer cells have elevated glycolysis than oxidative phosphorylation. In contrast, the redox ratios of malignant samples increased with a comparison of nonmalignant samples for bladder cancer cells [45], breast cancer cells [46] and human breast tissues [39]. In this study, it was found that the ORR (NADH/FAD) reduced with the development of cervical cancer, indicating the cellular metabolism change in neoplastic cells than that of in normal cells.…”

“…In the works on breast cancer cells [38,44], the redox ratio in metastasizing MDA-MB231 cells was lower than non-metastasizing MCF7, which the authors attributed to more aggressive phenotype of the metastasizing line. In contrast, the redox ratios of malignant samples increased with a comparison of nonmalignant samples for bladder cancer cells [45], breast cancer cells [46] and human breast tissues [39]. It suggests that the alteration of redox ratio is sensitive to characterize the metabolism change and can be serve as biomarkers of cancer detection.…”

CyTOF analysis identifies unusual immune cells in urine of BCG-treated bladder cancer patients

“…To address these issues, several experiments were carried out to optimise the methodology for flow cytometry of cells in urine. In hypoxic environments, like urine, cells have their metabolism skewed towards glycolysis and accumulate nicotinamide dinucleotides (NADH and FAD) which have fluorescence peaks in the range of the fluorophores used for flow cytometry (NADH Ex Max = 350nm; FAD Ex Max = 450nm; NADH Em Max = 450nm, FAD Em Max 530nm) (Palmer et al, 2015). Thus, fluorescence artefacts were reduced by turning off the green channels in the flow cytometer, so that endogenous fluorescence would not interfere.…”

Two‐photon optical imaging, spectral and fluorescence lifetime analysis to discriminate urothelial carcinoma grades

“…Above all, it provides a different endogenous contrast analysis compared to standard microscopy and confocal endomicroscopy. Although the heterogeneity of tissue structure can lead to complex signal interpretation, endogenous fluorescence analysis of urothelial tissue could be a promising way to avoid metabolic alteration related to external markers . The multimodal technique is an improved alternative to the unimodal one since it highlights tumors characteristics more specifically and precisely.…”