Characterize And Identify Secreted High Molecular Weight Heparanase From Pc3m Conditioned Medium

Abstract Introduction: Neutrophils, platelets, lymphocytes are typical sources of NAP-2 which is associated with heparanase activity. Heparanase degrades polymeric heparan sulfate molecules into shorter oligosaccharides, participating in extracellular matrix degradation. It is active under acidic conditions during tumor invasion and inflammatory processes. Our lab previously found that some cell lines like androgen independent prostate cancer cells (PC3M) can secrete a protein that reacts with anti-NAP-2 antibody, but has a much higher molecular weight(>50KD) than NAP-2 (MW~6-14 KD), and has heparanase activity. The purpose of this study is to characterize and identify this protein. Procedures: Immunoprecipitation was performed using Pierce DirectIP kit according the manufacturer’s instructions. Heparin binding affinity column used HiTrap™ Heparin HP column from GE Healthcare Bio-Sciences. The binding buffer was 10mM NaAcetate pH 5.0, the eluting buffers were 0.5M-2M NaCl in 10mM NaAcetate pH 5.0. The mass spectrometry was done by KCI Proteomics Core facility. Data: The immunoprecipitation method confirmed that this higher molecular weight protein indeed can be pulled down by the NAP-2 antibody, and after using heparin binding affinity column to purify, we can still get the > 50KD band on the western blot for NAP-2, meaning it is a heparin binding protein. Conclusions: A protein identified with NAP-2 antibody, but with higher molecular weight than native NAP-2 is found in the conditioned medium of PC3M cells that binds heparin, further confirming a potential role in tumor progression for prostate cancer. Citation Format: Donghong Ju, Mary A. Kosir. Characterize and identify secreted high molecular weight heparanase from PC3M conditioned medium [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 946. doi:10.1158/1538-7445.AM2017-946