Tomoaki Ito
Juntendo University, Japan
Title: ERC/mesothelin as a biomarker for mesothelioma and gastrointestinal cancer
Biography
Biography: Tomoaki Ito
Abstract
Previously, we found that the ERC (Expressed in Renal Carcinoma) gene was preferentially expressed in renal cancers in the Eker rat. Furthermore, we subsequently confirmed that ERC is a homolog of the human mesothelin gene, a gene that is strongly expressed in normal mesothelial cells, mesotheliomas, and non-mucinous ovarian carcinomas. The ERC/mesothelin gene (MSLN) encodes a 71 kDa precursor protein, which is cleaved to yield 31 kDa N-terminal (N-ERC/mesothelin) and 40 kDa C-terminal (C-ERC/mesothelin) proteins. N-ERC/mesothelin (also known as megakaryocyte-potentiating factor; MPF) is a soluble protein and is released into the extracellular space and blood. C-ERC/mesothelin is a glycoprotein that is tethered to the cell surface by a glycosylphosphatidylinositol anchor. C-ERC/mesothelin expression of tumor by immunohistochemistry can be correlated with patient’s survival in several human cancers. Soluble mesothelin-related peptide (SMRP) has proven to be a promising biomarker in the sera of patients with mesothelioma and ovarian cancer. As for secreted N-ERC/mesothelin, we previously devised a novel enzyme-linked immunosorbent assay (ELISA) system for determining its concentration in serum and showed that it is useful for diagnosing human mesothelioma and ovarian cancer. In addition, we demonstrated that C-ERC/mesothelin was expressed in gastric cancer and pancreatic cancer tissues. Meanwhile, increased serum N-ERC/mesothelin concentrations are not specific to these patients with gastric cancer or pancreatic cancer. Although N-ERC/mesothelin is established as a reliable marker for mesothelioma, N-ERC/mesothelin is not useful as a diagnostic marker of gastric cancer and pancreatic cancer.
