The Functional Identification Of Specific Targeting Peptides-SISSLTH To Chinese Human Bladder Cancer BIU-87Cells In Vitro And In Vivo

Background: Bladder cancer (Bladder carcinoma) is one of the most commonclinical malignancy, and its incidence and mortality ranks first place in the urinarytract tumors. Non-muscle invasive bladder cancer accounted for about75-85%of allbladder tumors, although its low degree of malignancy, but about10%of patientseventually developed into muscle invasive bladder cancer. So early bladder cancerdiagnosis and targeted therapy has become a hot spot in the field of medicalresearch.Objective: To establish non-muscle invasive bladder cancer xenograft model in nudemice.In order to identify the binding specificity of the peptide-SISSLTH to Chinesehuman bladder cancer BIU-87cells，which had already been obtained from thelaboratory,flow cytometry and confocal laser scanning technology were applied.Theresult of the experiment may provide a theoretical foundation for the earlydiagnosis,surgical resection and accurately targeted therapy of bladder cancer.Methods: The human bladder cancer cell line BIU-87were suspended in Matrigelbeforehand，then injected them into the nude mice. The small peptide fragments andisothiocyanate(FITC)-conjugated peptide fragments-SISSLTH were synthesized andpurified. By using flow cytometry and confocal laser scanning technology to identifythe specificity and affinity of the small molecule peptide fluorescent probeFITC-SISSLTH to bladder cancer, prostate cancer and liver cancer cells, and thebio-distribution of the small molecular probes in vivo. Results:1Successfully established xenograft model in nude mice by using Matrigel as tumorcell suspensions.2The results of flow cytometry and confocal microscopy techniqueat the cellular level showed that the affinity of the small peptide fluorescent probeFITC-SISSLTH to Chinese human bladder cancer BIU-87cell line was significantlyhigher than other two cell lines.By using the confocal microscopy technique, theexperiment of the bio-distribution of the probe in nude mice in vivo showed theprobe can be specifically enriched in tumor tissues but other organs rarely.In aconclusion,the small peptide fluorescent probe FITC-SISSLTH had the ability ofspecificity and targeting to bladder cancer.Conclusion: In this study,we first successfully used Matrigel as the tumor cellsuspensions to establish the xenograft model in nude mice, and all nude mice wereformed transplanted tumors.In our previous study,we used phage display peptidelibrary screening technology and obtained the specific binding peptide fragments-SISSLTH to bladder cancer BIU-87cell line.In this study,in order to test and verifythe affinity of the small peptide fluorescent probe FITC-SISSLTH to Chinese humanbladder cancer BIU-87cell line,the flow cytometry and confocal microscopytechnique were applied,the result indicated that the affinity of the probe to bladdercancer cells was much higher than liver cancer cells and prostate cancer cells.Wealso proved that the probes can be specifically enriched in tumor tissues but not inother organs in vivo.From the above, the small molecular peptide fragments-SISSLTH has the characteristics of high specificity and affinity to cells and tissuesof bladder cancer,which will provide some experimental and theoretical foundationin diagnosis,accurate resection and targeted therapy in the future.