A new non-muscle-invasive bladder tumor-homing peptide identified by phage display in vivo

Abstract

Bladder cancer is common and widespread, and its incidence is increasing. Many new diagnostic methods combined with state-of-the-art technology have been introduced in cystoscopy to collect real-time images of the bladder mucosa for diagnosis, but often miss inconspicuous early-stage tumors. Fluorophore-labeled peptides with high sensitivity and specificity for cancer would be a desirable tool for the detection and treatment of tiny or residual bladder tumors. Phage display and the human non-muscle-invasive bladder cancer cell line BIU-87 were used to identify a peptide. The isolated phage display peptide (CSSPIGRHC, named NYZL1) was tested in vitro for its binding specificity and affinity. Accumulation into xenograft tumors in a nude mouse model was analyzed with FITC-labeled NYZL1. NYZL1, with strong tumor-homing ability, was identified by in vivo phage library selection in the bladder cancer model. The NYZL1 phage and synthetic FITC-labeled NYZL1 peptides bound to tumor tissues and cells, but were hardly detected in normal control organs. Notably, accumulation of FITC-NYZL1 in bladder tumor cells was time-dependent. Biodistribution studies of xenografts of BIU-87 cells showed accumulation of injected FITC-NYZL1 in the tumors, and the bound peptide could not be removed by perfusion after 24 h. The mouse model of bladder tumor showed increased fluorescence intensity in the tumor-bearing bladder in comparison with normal bladder tissues after 4–6 h. In conclusion, NYZL1 may represent a lead peptide structure applicable in the development of optical molecular imaging.

Phage Display-Derived Peptide-Based Dual-Modality Imaging Probe for Bladder Cancer Diagnosis and Resection Postinstillation: A Preclinical Study

“…The tumor-specific peptide PLSWT7 was selected by phage display technology. Several peptides, such as CSNRDARRC [20], PLZ4 [21], and NYZL1 [16], show effective binding activity with BC-specific tumors; however, CSNRDARRC and PLZ4 were screened from muscle-invasive BC cell lines, whereas NMIBC accounts for 70% of all patients with BC. NYZL1 was screened from NMIBC cell lines, but in vivo studies are lacking.…”

“…For the selection of BC-binding phage clones, the Ph.D.-C7C Phage-display Peptide Library Kit (New England Biolabs, Beverly, MA, USA) was used as previously described [16]. Subcutaneous tumor-bearing mice received 3 × 10 10 plaque forming units (PFUs) of the phage peptide library via tail vein injection.…”

Application of Phage-Displayed Peptides in Tumor Imaging Diagnosis and Targeting Therapy

“…Yang et al successfully isolated and identified a peptide (CSSPIGRHC) with high affinity and specificity targeting to bladder cancer cell BIU-87 by phage display. The peptide synthesized and conjugated with FITC provides a promising diagnostic imaging approach for bladder cancer in humans (Yang et al 2016 ). Dysplasia is a pre-malignant status in Barrett’s esophagus that is difficult to detect on screening endoscopy because of its flat architecture and patchy distribution.…”

Endoscopic Molecular Imaging plus Photoimmunotherapy: A New Strategy for Monitoring and Treatment of Bladder Cancer

“…The previous studies demonstrated that they have the ability to specifically bind to bladder tumor tissue. 38 , 39 , 40 CQDGRMGFC peptide was synthesized by a one-bead, one-compound combinatorial chemistry approach. After conjugating with Cy5.5, the molecular fluorescent tracer selectively accumulated in bladder tumor tissue of patient-derived xenograft mouse models.…”