优化S100A9探针以增强CD147靶向用于胰腺导管腺癌的影像引导手术

Background: Pancreatic ductal adenocarcinoma, PDAC, remains of the deadliest cancers with the 5-year survival rate being 10-15%. Surgery is one of the only curable treatments for PDAC with up to 70% of patients that are candidates for surgery having positive margins; it is critical to have accurate imaging of PDAC which can contribute to patient stratification. S100A9 is a calcium binding ligand that binds to CD147, also designated as extracellular matrix metalloproteinase inducer (EMMPRIN), a membrane-bound glycoprotein. To better visualize PDAC cells, an S100A9 derivative Near-infrared fluorescent probe was created to have increased binding to CD147 while minimizing off-target accumulation. Methods: The pancreatic adenocarcinoma cancer cell lines, MiaPaca2, Panc1, Suit2, S2VP10 and S2013 were assessed for CD147 levels using western blot. The 114 amino acid S100A9 was synthesized using microwave chemistry and lyophilized. Hilyte 750 succinimidyl ester and Hilyte 750 amine reactive dyes were independently conjugated to the S100A9 peptide to determine the ideal orientation. Spectroscopy confirmed the conjugation of the probes. NIR imaging determined 750-S100A9 probes binding to S2VP10 cells. S100A9 peptide length was reduced to 89 or 80 amino acids and conjugated to HiLyte Fluor 750 acid SE dye on the C-Terminal end. Conjugation was tested with spectroscopy and the full length and cut down probes binding to S2VP10L were tested with NIR imaging. Results: The western blot demonstrated that MiaPaca2, Panc1 and S2013 were highly positive for CD147 while Suit2 and S2VP10 were less positive. Successful conjugation of peptides to the reactive dyes resulted in an OD of 0.1 each. 750 dye conjugated to the C-terminal of the S100A9 probe determined stronger binding to S2VP10 at 279,600 a.u. at 500 nM compared to 4,055 a.u. of N-terminal 750-S100A9 (p< 0.05). The 89 amino acid probe resulted in the highest expression at 291,760 a.u. compared to the full-length at 46,580 a.u. and the S100A9-750 80 amino acid probe at 115,200 a.u. when assessed with binding to S2013Q (p< 0.05). Conclusion: CD147 is a suitable target for PDAC using an S100A9 ligand conjugated near infrared fluorescent dye. In addition, S100A9 cut down to 89 amino acids on the C-Terminal with the HiLyte Fluor 750 acid SE dye determines to be a strong target for PDAC. The findings suggest that off-target accumulation of S100A9 could be minimized with the use of the smaller probe. The results also suggest that the S100A9 probes can improve detection and treatment of PDAC specificity with contrast agents or nanoparticles.