Radiosynthesis and Preclinical Evaluation of [ 68 Ga]Ga-NOTA-PTP Profiling Plectin-1 Expression for Pancreatic Cancer Imaging

Pancreatic ductal adenocarcinoma (PDAC) remains challenging to diagnose in its early stages. Capitalizing on the established overexpression of plectin-1 in PDAC, we developed a novel plectin-1-targeted positron emission tomography (PET) radiotracer, [⁶⁸Ga]Ga-NOTA-PTP, for precise PDAC imaging. The NOTA-PTP conjugate was synthesized, characterized, and efficiently radiolabeled with ⁶⁸Ga, achieving high radiochemical purity (>99%). The radiotracer displayed a strong binding affinity for plectin-1 (IC₅₀ = 12.8 nM) and exhibited time-dependent accumulation in PDAC cells. In murine PDAC xenografts, PET imaging demonstrated the rapid and specific tumor uptake of [⁶⁸Ga]Ga-NOTA-PTP, enabling the visualization of peritoneal metastases. Targeting specificity was further verified by both the significant reduction in tumor uptake upon preadministration of the unlabeled compound and the positive correlation between tracer accumulation and plectin-1 expression levels. Collectively, this work introduces the first plectin-1-targeted PET probe for specific and sensitive detection of PDAC and metastatic lesions through efficient plectin-1 engagement.