E.S. Yoo

Targeting Bladder Tumor Cells In vivo and in the Urine with a Peptide Identified by Phage Display

Bladder cancer is one of the most common tumors of the genitourinary tract. Here, we use phage display to identify a peptide that targets bladder tumor cells. A phage library containing random peptides was screened for binding to cells from human bladder tumor xenografts. Phage clones were further selected for binding to a bladder tumor cell line in culture. Six clones displaying the consensus sequence CXNXDXRX/RC showed selective binding to cells from primary human bladder cancer tissue. Of these, the CSNRDARRC sequence was selected for further study as a synthetic peptide. Fluorescein-conjugated CSNRDARRC peptide selectively bound to frozen sections of human bladder tumor tissue, whereas only negligible binding to normal bladder tissue was observed. When the fluorescent peptide was introduced into the bladder lumen, in a carcinogen-induced rat tumor model, it selectively bound to tumor epithelium. Moreover, when the peptide was intravenously injected into the tail vein, it homed to the bladder tumor but was not detectable in normal bladder and control organs. Next, we examined whether the peptide can detect tumor cells in urine. The fluorescent peptide bound to cultured bladder tumor cells but not to other types of tumor cell lines. Moreover, it bound to urinary cells of patients with bladder cancer, while showing little binding to urinary cells of patients with inflammation or healthy individuals. The CSNRDARRC peptide may be useful as a targeting moiety for selective delivery of therapeutics and as a diagnostic probe for the detection of bladder cancer. (Mol Cancer Res 2007;5(1):11–19)

Can magnetic resonance angiogram be a reliable alternative for donor evaluation for laparoscopic nephrectomy

Abstract:  Background:  While hand‐assisted laparoscopic donor nephrectomy (HLDN) is less invasive, which can encourage kidney donation, it requires more exact information about the renal vascular anatomy because of its limited visual field during nephrectomy. MRA is also an attractive choice because of its minimal invasiveness; further, it is an outpatient‐based procedure, it uses non‐nephrotoxic contrast material and it has no radiation. The aim of our study was to evaluate the effectiveness of gadolinium enhanced three‐dimensional MRA (GdE‐3D MRA) in a group of potential live donors who were candidates for HLDN.

TARGETING BLADDER TUMOUR CELLS IN VIVO AND IN THE URINE BY A PEPTIDE IDENTIFIED USING PHAGE DISPLAY

10071 Background: Bladder cancer is one of the most common tumors of genitourinary tract. Selective delivery of drugs to tumor tissues is important for effective tumor therapy. Here we identified a peptide targeting bladder tumor cells using phage display. METHODS Phage peptide library containing CX7C (C-cysteine and X-any amino acid residue) was based on T7 415-1b phage vector (Novagen). Tumor xenografts were prepared by subcutaneously injecting BALB/c Nu/nu female nude mice with HT-1376 bladder tumor cells. For a carcinogen-induced tumor model, Fischer 344 female rats were supplied ad libitum with tap water containing 0.05% N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) for 8 weeks. RESULTS A phage library containing CX7C random peptides was screened for selective binding to cells from human bladder tumor xenografts. Selected phage clones were individually evaluated for binding to cultured bladder tumor cells and for binding to cells from human tumor tissues of six patients. The peptide displayed by the most promising clone was synthesized and designated as Bld-1. Fluorescein-conjugated Bld-1 peptide showed selective binding to frozen sections of human bladder tumor tissues of three patients. In vivo tumor targeting was examined in a carcinogen-induced rat tumor model (n=20). When the fluorescent peptide was introduced into the bladder lumen, it selectively bound to tumor epithelium. Next, when the fluorescent peptide was intravenously injected into the tail vein, it homed to the bladder tumor, but was not detectable in normal bladder and control organs such as lung. Moreover, the fluorescent peptide bound to cells from urinary specimens of tumor patients (n=10), whereas little binding was observed in cells from healthy individuals (n=3). CONCLUSIONS The Bld-1 peptide may be useful for targeting bladder tumor cells in vivo and in the urine. No significant financial relationships to disclose.