Preclinical study of bladder cancer diagnosis using tumor homing peptide fluorescent molecular probe

Abstract

Objective To evaluate the features of optical molecular imaging of bladder tumor cells labeled by tumor homing peptide fluorescent molecular probe, and to explore the theoretical foundation of optical molecular imaging for bladder cancer diagnosis. Methods After prepared the FITC-CSNRDARRC fluorescent molecular probe, laser scanning confocal microscope, immuno fluorescence and multispectral fluorescence in vivo optical molecular imaging system have been used to evaluate the binding sites, the affecting factors of binding rates, the specificity and the targets. BIU-87 bladder tumor cell line, BIU-87 bladder tumor cell line, 68 cases of paraffin bladder tumor tissue samples, 16 cases of paraffin glandular bladder inflammatory samples, 43 cases of paraffin renal clear cell carcinoma samples, 68 cases of paraffin gastric adenocarcinoma samples, 29 cases of urine exfoliated cells suspected bladder cancer and BIU-87 bladder cancer nude xenograft have been used in this study. Results The binding site of FITC-CSNRDARRC fluorescent molecular probe were at the nucleus of labeled bladder tumor cells. The binding rates were correlated linearly with the dose of probe and the grade of pathology. The in vitro and in vivo studies demonstrate that the probe has a binding specificity with bladder tumor. When the FITC-CSNRDARRC fluorescent molecular probe labeled tumor cells, bright green spots were observed under laser scanning confocal microscope. The bright green spots were more apparent after stained by DAPI again. The tissue samples and tumor cells in the urine can be successful labeled and identified by fluorescence microscope. Optical molecular imaging of in vivo xenograft tumor tissues showed fluorescent spots under EMCCD. Conclusions The labeled loci of single cell by FITC-CSNRDARRC probe have been identified. The spatial resolution of optical molecular image is related to sensitivity of CCD, and the optical molecular imaging cannot be imaged by the conventional endoscope camera. Key words: Urinary bladder neoplasms; Tumor homing peptide; Fluorescent molecular probe; Optical molecular imaging; Molecule diagnosis