Objectives: Human prostate cancer cells overexpress VPAC1 receptors and are voided in urine. VPAC1 specific peptides, conjugated with NIR fluorophore (Figure 1, TP4303), served as a noninvasive prostate cancer detection tool. The goal of this investigation was to evaluate the ability of TP4303 to detect VPAC1 expression on voided urine cells and correlate with clinical findings and NKX 3.1immunohisto chemistry test. Methods: TP4303 was synthesized on solid state TG Sieber resin with added cysteine at the N- terminus. The cleaved peptide was purified by HPLC, reacted with the fluorophore, purified and characterized. TP4303 is composed of the same VPAC1 receptor specific peptide that we used to target VPAC1 receptors on breast and Prostate cancer for PET imaging, but is conjugated with a maleimide form of a near infrared (NIR) fluorophore (Ex. 630nm and Em. 730nm). Voided urine was collected from patients as a standard of care. The urine was then cytospun and cells fixed in 95% ethanol. The cells were then incubated with 0.5 μg TP4303 in 200 μL water for 20 min. , thoroughly rinsed with cold water, air, dried and cell nucleus were stained with 10 μL of DAPI. Slides were then covered with a coverslip and analyzed using a confocal microscope. Results: The malignant cells that express VPAC1 receptors and interact with TP4303 show fluorescence around the cell, whereas the normal cells do not have any fluorescence. Conclusions: The method is simple, noninvasive, and rapid, differentiates between cancer and normal cells with high sensitivity, and permits prostate cancer diagnosis efficiently.

Noninvasive prostate cancer detection biomarker

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.