Development of Preladenant-Based Radiotracers for Imaging AR in Tumors.

Activation of the adenosine 2A receptor (AR) can lead to tumor immunosuppression, which results in poor prognosis of immunotherapy. The aim of this study was to design novel F-labeled probes ([F]F-PFP and [F]F-PFP) to visualize AR in the tumor. The uptake of radioprobes in AR-negative 4T1 breast tumor was lower than that of AR-positive B16F10 melanoma at 1 h p.i. (1.22 ± 0.36% ID/g vs 2.80 ± 0.72% ID/g), 2 h p.i. (1.09 ± 0.20% ID/g vs 2.93 ± 0.76% ID/g) and 3 h p.i. (0.89 ± 0.27% ID/g vs 2.73 ± 0.58% ID/g), respectively. B16F10 lung metastasis models were employed to expand the application scenarios, observing significantly higher uptake of [F]F-PFP in metastatic lesions compared to normal lung tissue (5.55 ± 2.18% ID/g vs 1.89 ± 0.65% ID/g, tumor/lung ratio ∼3). It is given that [F]F-PFP might lay the foundation for establishing an AR-targeted imaging evaluation system for tumors, which will provide more precise guidance for personalized treatment.