Mesothelin (MSLN) was initially cloned from a library of human pancreatic cancer cells. It was also identified by a monoclonal antibody, MAb K1, which recognized a glycoprotein present on the surface of mesothelial cells. Mouse and human mesothelin are 69% identical. Mouse MSLN gene encodes a ~71 kD precursor protein of 625 amino acids. The C-terminal glycosylphosphatidylinositol (GPI) anchor addition signal is removed and replaced with a GPI anchor. The MSLN precursor is cleaved by furin into two products, a ~31 kD mature megakaryocyte potentiating factor and a ~40 kD GPI-anchored membrane-bound mature mesothelin. The 40 kD GPI-anchored mesothelin can be released by treatment with phosphatidylinositol-specific phospholipase C. Soluble mesothelin specifically binds to ovarian carcinoma cell line OVCAR-3, mediated by the cancer antigen 125 (CA125), a mucin-like glycoprotein on the surface of tumor cells. CA125 and mesothelin are co-expressed in advanced grade ovarian adenocarcinoma, and it has been speculated that CA125 might contribute to the metastasis of ovarian cancer to the peritoneum by initiating cell attachment to the mesothelial epithelium via binding to mesothelin. Also, mesothelin and CA125/mucin 16 (CA125/MUC16) are co-overexpressed at the invading edges of pancreatic cancer tissues, and their expression correlates with poor survival rates. Mesothelin expression in the mouse embryo is high on days 7 and 17 of gestation, but absent on day 11 and low on day 15, suggesting developmental regulation. Nevertheless, mesothelin function is not essential for growth or reproduction in mice.
Size
25 μg
Concentration
n/a
Applications
BA
Other Names
Antigen recognized by antigen K1, megakariocyte Potentiating factor (MPF), soluble MPF, Mesothelin releated protein