Title:In Vitro High Throughput Phage Display Selection of Ovarian Cancer Avid Phage Clones for Near-Infrared Optical Imaging
VOLUME: 17 ISSUE: 10
Author(s):Mette Soendergaard, Jessica R. Newton-Northup and Susan L. Deutscher
Affiliation:Harry S. Truman Memorial Veterans Hospital, Columbia, MO 65201, USA.
Keywords:Cancer imaging, near-infrared, optical imaging, ovarian cancer, peptide, phage display.
Abstract:Ovarian cancer is among the leading causes of cancer deaths in women, and is the most fatal gynecological
malignancy. Poor outcomes of the disease are a direct result of inadequate detection and diagnostic methods, which may
be overcome by the development of novel efficacious screening modalities. However, the advancement of such
technologies is often time-consuming and costly. To overcome this hurdle, our laboratory has established a time and cost
effective method of selecting and identifying ovarian carcinoma avid bacteriophage (phage) clones using high throughput
phage display technology. These phage clones were selected from a filamentous phage fusion vector (fUSE5) 15-amino
acid peptide library against human ovarian carcinoma (SKOV-3) cells, and identified by DNA sequencing. Two phage
clones, pM6 and pM9, were shown to exhibit high binding affinity and specificity for SKOV-3 cells using micropanning,
cell binding and fluorescent microscopy studies. To validate that the binding was mediated by the phage-displayed
peptides, biotinylated peptides (M6 and M9) were synthesized and the specificity for ovarian carcinoma cells was
analyzed. These results showed that M6 and M9 bound to SKOV-3 cells in a dose-response manner and exhibited EC50
values of 22.9 ± 2.0 μM and 12.2 ± 2.1μM (mean ± STD), respectively. Based on this, phage clones pM6 and pM9 were
labeled with the near-infrared fluorophore AF680, and examined for their pharmacokinetic properties and tumor imaging
abilities in vivo. Both phage successfully targeted and imaged SKOV-3 tumors in xenografted nude mice, demonstrating
the ability of this method to quickly and cost effectively develop novel ovarian carcinoma avid phage
