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Updated: Jun 7, 2026
Quantitation of Intra-peritoneal Ovarian Cancer Metastasis
Published on: July 18, 2016
In-labeled KCCYSL peptide as an imaging probe for ErbB-2-expressing ovarian carcinomas
Susan L Deutscher1, Said D Figueroa, Senthil R Kumar
1Department of Biochemistry, University of Missouri-Columbia School of Medicine, Columbia, MO 65211, USA.
Abstract:
Aberrant expression of ErbB-2, a member of the epidermal growth factor family of receptors, has been implicated in the formation of various malignancies including ovarian cancer. The objective of this study was to determine if the bacteriophage (phage) display-selected ErbB-2 targeting peptide, KCCYSL, once radiolabeled with (111)In would serve as a tumor targeting and Single Photon Emission Computed Tomography (SPECT/CT) imaging agent in a mouse model of human ovarian carcinoma expressing ErbB-2. The KCCYSL peptide was synthesized with a chelator 1,4,7,10-tetra-azacyclododecane-N,N',N",N"'-tetraacetic acid (DOTA), and a Gly-Ser-Gly (GSG) spacer between DOTA and amino terminus of the peptide and radiolabeled with (111)InC1(3). In vitro cell binding studies indicated that (111)In-DOTA-GSG-KCCYSL bound to cultured ovcar-3 carcinoma cells. Biodistribution studies in scid mice bearing human ovcar-3 tumor xenografts revealed a tumor uptake of 0.50 ± 0.05 percent injected dose per gram (%ID/g) at 1 h, and 0.39 ± 0.1 %ID/g at 2 h. Blocking studies with non-radiolabeled counterpart indicated a partial inhibition (41%) (P = 0.04) in tumor uptake of (111)In-DOTA-GSG-KCCYSL. In vivo tumor uptake of (111)In-DOTA-GSG-KCCYSL was clearly evident through SPECT/CT images after 2 h post injection. These studies suggest the potential of this peptide as a radiopharmaceutical for imaging of ErbB-2-expressing ovarian tumors.
Insights
A novel peptide, KCCYSL, radiolabeled with Indium-111 (111In), shows promise for imaging ErbB-2-positive ovarian tumors. SPECT/CT imaging confirmed tumor targeting in a mouse model, suggesting its potential as a diagnostic agent.
Area of Science:
- Oncology
- Radiochemistry
- Molecular Imaging
Background:
- Aberrant ErbB-2 receptor expression is linked to various cancers, including ovarian carcinoma.
- Targeted molecular imaging agents are crucial for detecting and characterizing ErbB-2-expressing tumors.
Purpose of the Study:
- To evaluate the potential of a phage display-selected peptide, KCCYSL, radiolabeled with 111In, as a SPECT/CT imaging agent for ErbB-2-positive ovarian cancer.
- To assess the in vitro and in vivo tumor-targeting capabilities of the 111In-labeled peptide.
Main Methods:
- Synthesis of KCCYSL peptide with DOTA chelator and GSG spacer.
- Radiolabeling with 111In and in vitro cell binding assays with ovcar-3 cells.
- In vivo biodistribution and SPECT/CT imaging studies in scid mice bearing human ovarian carcinoma xenografts.
Main Results:
- 111In-DOTA-GSG-KCCYSL demonstrated specific binding to ovcar-3 cells in vitro.
- Biodistribution studies showed tumor uptake of 0.50 ± 0.05 %ID/g at 1h and 0.39 ± 0.1 %ID/g at 2h.
- SPECT/CT imaging confirmed in vivo tumor visualization, with blocking studies showing partial inhibition of tumor uptake.
Conclusions:
- The 111In-labeled KCCYSL peptide exhibits favorable tumor targeting and imaging properties for ErbB-2-expressing ovarian tumors.
- This peptide shows potential as a radiopharmaceutical for SPECT/CT imaging in oncology.
- Further studies are warranted to explore its clinical applicability.
