Detection of RCC in early stages helps increase the life expectancy of the patient [4]. Two diagnosis methods, histopathology and image procedures (computed tomography scan, ultrasonography, or magnetic resonance imaging) provide increase the early detection of the RCC. Histopathologically, although several promising biomarkers such as Carbonic anhydrase IX, B7-H1 and P53 for RCC have been under investigation, none currently have been validated or are in routine use [5, 6]. Therefore, some novel molecular markers must be screened and identified for improving early diagnosis and prognosis of RCC. Phage display is a molecular

diversity technology that allows the presentation of large peptide and EPZ-6438 datasheet protein libraries on the surface of filamentous phage. Phage display libraries permit the selection of peptides and proteins, including antibodies, with high affinity and specificity for all targets. An important distinctive mark of this technology is the direct link that exists between the experimental phenotype and its encapsulated genotype. Phage display technology is a powerful tool for the selection of cell-specific peptide ligands at present [7]. Some laboratories

have applied this technology to isolate peptide ligands with good affinity and specificity for a variety of cell types. The specific ligands isolated from phage libraries can be used in diagnostic probe, therapeutic target see more validation, and drug design and vaccine development [8–10]. In the present study, we identified a specific novel peptide that bound to the cell surface of renal carcinoma cell line A498 generated in this laboratory by using in vitro phage-displayed random peptide libraries. Our results demonstrate that this biopanning strategy

can be used to identify tumor-specific targeting peptides. crotamiton One of our selected peptides, ZT-2 was most effective in targeting cells and tissues, indicating its potential for use in early diagnosis and targeted therapy of RCC. Materials Renal carcinoma line A498 and a normal renal cell line HK-2 were obtained from Medical Academy of China (Beijing, PR China). Fetal calf serum (FCS) and Dulbecco’s modified eagle’s medium (DMEM) were purchased from Gibco (Invitrogen, Carlsbad, USA). Phage DNA sequencing was performed by Shanghai Sangon Corp (Shanghai, PR China). Peptide ZT-2 (QQPPMHLMSYAG) and a nonspecific control peptide (EAFSILQWPFAH) were synthesized and labeled with fluorescein isothiocyanate (FITC) by Shanghai Bioengineering Ltd. Mass analysis of the peptides was confirmed by a matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and all peptides were > 90% pure as determined by reverse-phase HPLC. Peptide stock solutions were prepared in PBS (pH 7.4). Horseradish peroxidase-conjugated sheep anti-rabbit antibody and rabbit anti-M13 bacteriophage antibody were purchased from Pharmacia (Peapack, NJ, USA).