Estrogen Inducible Protein pS2 Antibody [GE2]

Background:

This antibody recognizes a polypeptide of ~6.5kDa, identified as Estrogen Inducible Protein pS2. The antibody's epitope is localized between amino acids 57-84. pS2 is a trefoil peptide. Trefoil peptides are protease resistant molecules secreted throughout the gut that play a role in mucosal healing. These peptides contain three intrachain disulfide bonds, forming the trefoil motif, or P-domain. Estrogen Inducible Protein pS2 is known to form dimers and this dimerization is thought to play a role in its protective and healing properties. About 60% of breast carcinomas are positive for estrogen inducible protein pS2. Staining is cytoplasmic, often with localization to the Golgi apparatus. It is shown to be localized in normal stomach mucosa, gastric fluid, goblet cells in the colon and small intestine, and in ulcerations of the gastrointestinal tract. Several studies have shown that estrogen inducible protein pS2 is primarily expressed in estrogen receptor-positive breast tumors and it may define a subset of estrogen-dependent tumors that displays an increased likelihood of response to endocrine therapy.