Prostate Specific Membrane Antigen (PSMA)-Targeted Photoacoustic Imaging of Prostate Cancer In Vivo

摘要

A sensitive, non-invasive method to detect localized prostate cancer, particularly for early detection and repetitive study in patients undergoing active surveillance, remains an unmet need. Here we propose a molecular photoacoustic (PA) imaging approach by targeting the prostate-specific membrane antigen (PSMA), which is over-expressed in the vast majority of prostate cancers. We performed spectroscopic PA imaging in an experimental model of prostate cancer, namely, in immunocompromised mice bearing PSMA+ (PC3 PIP) and PSMA− (PC3 flu) tumors through administration of the known PSMA-targeted fluorescence agent, YC-27. Differences in contrast between PSMA+ and isogenic control tumors were observed upon PA imaging, with PSMA+ tumors showing higher contrast in average of 66.07-fold with five mice at the 24-hour post-injection time points. These results were corroborated using standard near-infrared fluorescence imaging with YC-27, and the squared correlation between PA and fluorescence intensities was 0.89. Spectroscopic PA imaging is a new molecular imaging modality with sufficient sensitivity for targeting PSMA in vivo, demonstrating the potential applications for other saturable targets relevant to cancer and other disorders.