Characterization of the perimembrane fluorescence phenomenon allowing the detection of urothelial tumor cells in urine in the method performed by VitaDX ; Caractérisation du phénomène de fluorescence périmembranaire permettant la mise en évidence des cellules urothéliales tumorales dans les urines dans la méthode exploitée par VitaDX

To detect bladder cancer (BC), urine cytology and cystoscopy are the primary diagnostic tests used. Urine cytology is noninvasive, easy to collect, with moderate sensitivity and high specificity. It is an effective way to detect high-grade BCs, but it is less effective on low-grade ones. Recently, the fluorescent proper-ties of plasma membranes of urothelial tumor cells, called perimembrane fluorescence (PMF), found in urine cytology, have been shown to be of potential use in improving early detection of BC. The main objec-tive of this thesis was to characterize PMF for the detection of urothelial tumor cells in urine. During this work we were interested in the role that the morphological characteristic of the urothelial tumor cell plays in the PMF. We then tried to find a cell line model that did not show PMF in order to screen its protein and lipid composition with our BC model. To accurately analyze the slightest fluctuation in fluores-cence, a PMF quantification software was implemented. Failing to find lines without PMF, we analyzed the PMF of urothelial cells recovered from rat urine with those recovered directly from rat urothelium. Noting a difference in PMF depending on where the cells were recovered, we wanted to determine what cellular phe-nomenon might be involved in the change in PMF when the urothelial cell moves from urothelium to urine. The results obtained thus allowed us to better understand and characterize the PMF phenomenon. In view of our results, we suggest that the strong resistance of tumor cells to external aggression allow them to survive better in urine, contrary to healthy cells which, once in suspension, are more sensitive to these aggressions responsible for the loss of their PMF. ; Pour détecter le cancer de la vessie (CV), la cytologie urinaire et la cystoscopie sont les premiers tests diagnostiques utilisés. La cytologie urinaire est non invasive, facile à collecter, avec une sensibilité moyenne et une spécificité élevée. C’est un moyen efficace de détecter les CV de haut grade, ...