Anti-NPTX2 monoclonal antibody Made to order

Objectives: Percutaneous fine-needle aspiration cytology or biopsy has been used for pathological confirmation in pancreatic cancer. Sometimes, it is difficult to approach the mass because of surrounding major vessels, and there is a risk of seeding. Although endoscopic retrograde cholangiopancreatography (ERCP)-guided pancreatic duct brush cytology is less invasive, its reliability is very low. Recently, aberrantly methylated genes were reported in pancreatic cancer tissue. This study was to develop a novel molecular diagnostic approach based on epigenetic characteristics. Methods: We enrolled pathologically proven 33 pancreatic cancer patients and 22 benign pancreaticobiliary disease patients. The ERCP-guided pancreatic duct brush cytology samples were obtained. Genomic DNA was extracted, and NPTX2 CpG island hypermethylation was examined quantitatively by real-time polymerase chain reaction amplification after chemical modification. Results: Pancreatic cancer cytology samples had statistically significant higher levels of NPTX2 methylation compared with benign diseases, and the optimal cutoff value of NPTX2 methylation was 1.2%. The sensitivity was 87%, and specificity was 80%, whereas pathological examination by ERCP-guided pancreatic duct brush cytology had a sensitivity of 38%. Conclusions: The quantitative analysis of NPTX2 hypermethylation may play a role in making highly sensitive and less invasive diagnosis of pancreatic cancer. Therefore, NPTX2 hypermethylation could be a promising molecular diagnostic marker.

Neuronal pentraxins (NPTX) and their corresponding receptors (NPTXR) have been studied as synapse-associated proteins in the nervous system, but their role in cancer is largely unknown. By applying a multidisciplinary, high-throughput proteomic approach, we have recently identified a peptide ligand motif for targeted drug delivery to neuroblastoma. Here, we report the sequence similarity between this peptide and a conserved portion of the pentraxin domain that is involved in the homo-and hetero-oligomerization of NPTX2 and NPTXR. We show that, in comparison with normal tissues, NPTX2 and NPTXR are overexpressed in vivo in mouse models, as well as in human Schwannian stroma-poor, stage IV neuroblastoma. Both proteins are concentrated in the vicinity of tumor blood vessels, with NPTXR also present on neuroblastic tumor cells. In vivo targeting ofNPTX2 and NPTXR with the selected peptide or with specific antibodies reduces tumor burden in orthotopic mouse models of human neuroblastoma. In vitro interference with this ligand/receptor system inhibits the organization of neuroblastoma cells in tumor-like masses in close contact with vascular cells, as well as their adhesion to normal microenvironment-derived cells, suggesting a role in the cross-talk between tumor and normal cells in the early steps of neuroblastoma development. Finally, we show that NPTX2 is a marker of poor prognosis for neuroblastoma patients. (C) 2015 AACR.