Prostate stem cell antigen (PSCA) is a glycosylphosphatidylinositol (GPI)-anchored cell surface protein belonging to the Thy-1/Ly-6 family of cell-surface proteins. PSCA is a 123-amino acid protein with 30% homology to stem cell antigen 2 (SCA2), a cell surface marker of immature thymic lymphocytes. PSCA maps to chromosome 8q24.2, a region of genetic gain/amplification in a large percentage of advanced prostate cancers (PCa). PSCA is initially identified in a human PCa cell xenograft. Now studies indicate that PSCA is expressed mainly in differentiating cells. PSCA can be expressed in some normal tissues, but its expression in PCa and other cancer tissues (such as pancreatic, gestational trophoblastic and clear renal cell carcinoma) is significantly higher compared to normal tissues, which has been recognized as a critical marker, In contrast, reduced PSCA expression was observed in the head-and-neck squamous cell, esophagus and stomach tumors, suggesting that PSCA has oncogenic activity in the overexpressed tumor but a tumor suppressor activity in the low-expressed tumor. The expression of PSCA can be influenced by androgen. However, the molecular functions of the PSCA are not clear. PSCA can be a potential diagnostic and/or therapeutic target in PCa.
The role of PSCA in tumorigenesis appears complex, involving pro-tumorigenic and anti-tumorigenic effects in different contexts. It has been shown that PSCA is involved in a variety of tumor growth activities such as immune response, cell proliferation and/or cell-death induction. Yin Yang 1 (YY1) has been identified as a modulator to inhibit or stimulate promoter activity of PSCA in prostate epithelial cell lines. PSCA homolog, SCA-2, Thy-1, CD59, is involved in anti-cancer immune response, implying that PSCA may take part in the immune response. PSCA is likely to regulate cell growth through p53-related signaling pathways. In addition, a significant association between PSCA downregulation and activation of genes downstream of the interferon (IFN-α/β) receptor was observed. This means that PCSA may be associated with inflammatory mechanisms.
Because of frequent PSCA overexpression in lots of cancer types, PSCA is an attractive candidate target for diagnosis, prognosis and therapeutic in the management of cancer patients. PSCA expression has been found to increase with advanced stage and androgen independence. In addition, PSCA has been noted to be highly expressed in foci of cribriform carcinoma, a subtype of Pca associated with a worse prognosis. These studies indicate PSCA provides valuable diagnostic and prognostic information. Several immunotherapeutic strategies targeting PSCA have been explored, including monoclonal antibodies, antibodies conjugated to cytotoxins, genetically engineered T cells, PSCA vaccination and peptide-loaded dendritic cells (DCs).
Fig.1 Presumptive PSCA signaling pathway and PSCA-targeted immunotherapy. (Saeki, 2010)
PSCA is up-regulated in the prostate, urinary bladder and pancreatic cancers. And its clinical utility has been shown in the diagnosis and prognosis of these cancers though the functions of PSCA are not completely understood. Creative Biolabs provides a full set of PSCA assay portfolio service, including but not limited to:
Creative Biolabs is specialized in providing a series of customized assay portfolio services to improve biotech and pharma discovery timelines and costs. We currently provide the most comprehensive portfolio of tumor marker assay services (e.g., PSCA assay portfolio service). We are proud to offer a broad range of services list to advance your project. Please feel free to contact us to discuss your individual needs with our in-house experts.
Reference
For Research Use Only | Not For Clinical Use
Download our brochure