STEAP (Six Transmembrane Epithelial Antigen of the Prostate)

Synthetic 18 amino acid peptide from near the carboxy terminus of human STEAP1 (GenBank accession no. EAL24166). For use with cat. no. S7500. Related antibody S7500: Reacts predominantly with STEAP. Does not crossreact with other STEAP proteins. Species Crossreactivity: human, mouse and rat, Prostate cancer is the most frequently diagnosed cancer and is the second leading cause of cancer-related deaths in American men. Although the early serum detection of prostate-specific antigen (PSA) plays important roles in early diagnosis, it may not distinguish prostate cancer from benign diseases. Recently, a novel protein, which contains 339 amino acids, named STEAP (six transmembrane epithelial antigen of the prostate), was identified in advanced prostate cancer. STEAP is unique among the currently known prostate cancer markers because of its putative secondary structure, from which one may predict that it functions as a potential channel protein. STEAP is strongly expressed in advanced prostate cancer and some extent expression in other cancers, such as colon and ovarian cancer cell lines. The six-transmembrane epithelial antigen of prostate 1 (STEAP1) was the first member of a family of metalloreductases identified as cell-surface antigens in prostate tissue (1,2). The normal function of STEAP is still uncertain, unlike other members of the STEAP family, STEAP1 does not promote iron or copper reduction or uptake and lacks the FNO-like reductase domain critical for activity (3). However, its expression is highly increased in multiple cancer cell lines, including prostate, bladder, colon, and ovarian cancers. Supporting this is evidence that STEAP1 peptides can be used to stimulate CD8+ T cells from healthy donors, enabling them to recognize STEAP1-positive human tumor cells, suggesting that STEAP1 may a potential target for cancer immunotherapy (4). At least three isoforms of STEAP1 are known to exist. Applications (related antibody S7500: Suitable for use as blocking peptide in ELISA, Western Blot, Immunohistochemistry with S7500. Other applications not tested. Recommended Dilution: Optimal dilutions to be determined by the researcher. Positive Control: Human spleen tissue lysate , Storage and Stability:, Lyophilized powder may be stored at 4°C for short-term only. Reconstitute to nominal volume by adding sterile 40-50% glycerol and store at -20°C. Reconstituted product is stable for 24 months at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.