S100P Binding Protein (S100PBP)

Binding of S100P to S100PBP in vitro was dependent on Ca(2+) and Mg(2+). Quantitative PCR revealed upregulated S100P and S100PBP expression in pancreatic intraepithelial neoplasia and pancreatic ductal adenocarcinoma samples, and S100PBP expression was also upregulated in chronic pancreatitis samples. Both S100P and S100PBP showed upregulated expression in pancreatic cancer cell lines, including the HPDE cell line derived from normal pancreatic duct cells. In situ hybridization of normal pancreas detected S100PBP mRNA in islet cells and at low levels in some acinar cells, but not in ductal cells. However, in pancreatic ductal adenocarcinoma samples, S100PBP mRNA was detected in malignant ductal epithelial cells, as well as in islet cells and acinar cells.