RESUMEN
Objective:To screen the peptide binding to human bladder carcinoma cells specifically by using phage display technology in vivo.Methods: Nude mice were inoculated with bladder carcinoma cells BIU87 for establishing tumor-bearing mice model.The Ph.D.-C7CTM Peptide Library was injected intravenously via tail vein.Then we screened Phage containing exogenous peptides binding to bladder transitional carcinoma cells specifically.The phage peptide homed to the tumor tissues was obtained after 3 rounds screening in vivo.The phage clones affinity to BIU87 were identified by immunohistochemistry and ELISA.The positive peptide was synthetized by chemical methods after sequencing the positive monoclonal phage DNA.The tumor cell specificity of target peptide was identified by confocal laser scanning microscope and flow cytometry.Results:After 3 rounds screening in vivo,enrichment rate of phage was 4.334×102 times.Immunohistochemistry results showed that the dyeing of the tumor tissue had a rising trend following each round of phage screening,while liver had a lot of non-specific binding phage because the phages were metabolized through liver and kid-ney.The 30 phage clones were identified by ELISA and 10 clones had a strong affinity on BIU87 among 24 positive clones.Three amino acid sequences of positive phage clones were obtained.The highest rate of repeat sequences CSSPIGRHC(8/10) named NYZL1 and the FITC-C6-NYZL1 peptide was synthesized.Our results showed that it could bind to bladder carcinoma cells BIU87 specifically.Conclusion:We obtained the small molecular peptide NYZL1 binding to human bladder carcinoma specifically by means of phage display in vivo,which provide a theoretical basis for bladder carcinoma early diagnosis and targeted therapy.
RESUMEN
Objective To investigate the characters and targeted ability of FITC-CSNRDARRC molecular probe in labeling orthotopic transplantation tumor of bladder cancer in vivo.Methods From July 2013 to June 2014,the stability and characters of FITC-CSNRDARRC molecular probe were detected by spectrophotometer and molecular imaging and the optimum concentration and imaging time window were determined.30 BALB-C nude mice were randomly divided into experimental group (n =20) and control group(n =10).In control group,5 of them (group A) were ligated bilateral ureter,others(group B) were not.We established orthotropic transplanted bladder tumor (BIU-87) model by operation.And 0.2 ml probes (220 μmol/L) was then injected intravenously in all mice after 2 weeks.We obtained images and analyzed average gray value of the heart,lung,liver,spleen,bilateral kidney and orthotropic transplantation bladder tumor by using optical probe molecule fluorescence imaging system after 30 min,1 h,2 h,4 h and 12 h,respectively.Results After injected the FITC-CSNRDARRC molecular probes intravenously at 220 μmol/L,the fluorescence signal of tumor tissue strengthened gradually.The optimal imaging time window was 4 hours after injection.The illumination and temperature had little effect on the fluorescence signal.With the time passing after injection,the intensity of florescence signal progressively increasing,which reached the peak at4 h.The average gray value of tumor tissue at 1 h,2 h,3 h,4 h,5 h,6 h,8 h,12 h were 74.22,76.2,80.11,89.38,83.29,85.1,81.22,83.01,respectively.The fluorescence signal of normal tissue weakened gradually with the passage of time.Only liver and gall bladder could notice the fluorescence signal 4 hours after injection in group A.However,the relatively strong fluorescence signal could be found in liver and gall bladder in group B.Conclusions The characters of fluorescence probe are affected by its concentration.Its optimal concentration of labeling tumor is 220 μmol/L.The optical imaging time window was about 4 h after intravenous injection.The FITC-CSNRDARRC molecular probe can specifically bound to orthotopic transplanted tumor of bladder cancer in vivo.