Peptide-Based Probe Targeting Angiotensin Type‑1 Receptor Identifies Pancreatic Ductal Adenocarcinoma Using
Rohit Singh1, Happy Agarwal1, Ryan C Bynum1
1Stephenson Cancer Center, Department of Surgery, University of Oklahoma, Oklahoma City, Oklahoma 73104, United States.
Chemical & Biomedical Imaging
|March 27, 2026
Summary
A novel near-infrared (NIR) fluorescent probe, Angio1-750, successfully targets and visualizes pancreatic ductal adenocarcinoma (PDAC) cells. This imaging agent aids in detecting residual tumor foci, potentially improving surgical outcomes for this aggressive cancer.
Area of Science:
- Oncology
- Medical Imaging
- Biotechnology
Background:
- Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy with poor treatment options.
- Complete surgical resection (R0) is often hindered by microscopic residual tumor foci, leading to high recurrence rates.
- Improved intraoperative visualization of tumor margins is critical for enhancing surgical success in PDAC patients.
Purpose of the Study:
- To engineer and evaluate a peptide-based fluorescent imaging probe for visualizing angiotensin type-1 receptor (AT1R)-positive PDAC.
- To assess the probe's ability to detect residual tumor foci and improve surgical resection outcomes.
- To validate the probe's efficacy in preclinical models of PDAC.
Main Methods:
- Engineered a peptide-based imaging probe targeting AT1R, conjugated with 750 nm reporter dyes (Angio1-750).
- Assessed probe binding and uptake in AT1R-positive PDAC cells versus control cells using immunofluorescence and NIR imaging.
- Evaluated probe performance in orthotopic PDAC mouse models using multispectral optoacoustic tomography (MSOT) and ex vivo biodistribution studies.
Main Results:
- PDAC cells exhibited significant membranous AT1R expression, unlike control cells.
- Angio1-750 demonstrated specific binding to AT1R and higher uptake in PDAC cells.
- MSOT successfully detected Angio1-750 in PDAC tumors in vivo, with significant signals observed over time.
- Biodistribution studies confirmed tumor accumulation and renal clearance of the probe, with no observed toxicity.
Conclusions:
- The Angio1-750 probe shows promise for intraoperative visualization of PDAC.
- Successful tumor uptake and detection via MSOT in PDAC xenografts were demonstrated.
- This imaging approach could enhance the completeness of surgical resection for PDAC.
