SerpinB4

SerpinB4, also known as Squamous cell carcinoma antigen 2 (SCCA2), belongs to the high-molecular weight serine proteinase inhibitor (serpin) family. Squamous cell carcinoma antigen (SCCA) is expressed in normal squamous cell epithelia and in squamous cell carcinomas (SCC). Two nearly identical genes encode the inhibitory serpins SCCA1 (SERPINB3) and SCCA2 (SERPINB4). SerpinB4 formed a typical serpin-protease SDS-stable complex with both recombinant and native human granzyme GrM. SCCA2 expression is significantly related to E-cadherin expression and that the heterogeneous pattern of SCCA and E-cadherin in primary lesions is strongly associated with the high incidence of lymph node metastasis in cervical squamous cell carcinoma. Serpins (serine protease inhibitors) are known as a diverse family of protease inhibitors; however, various other biological activities including tumor suppression, have been recently reported for these molecules. SCCA2 may be involved in cancer behavior such as metastasis, and as such can be a useful marker in predicting lymph node metastasis.

SerpinB4 Related Areas

Enzyme>>Protease & Regulator>>Serine Protease & Regulator>>Serpin Superfamily>>SerpinB4

SerpinB4 Alternative Names

SerpinB4, LEUPIN, PI11, SCCA-2, SCCA1, SCCA2 [Homo sapiens]

Summaries for SerpinB4

OMIM - description for SerpinB4:

Squamous cell carcinoma antigen (SCCA) is a member of the ovalbumin family of serine proteinase inhibitors. The protein was isolated from a metastatic cervical squamous cell carcinoma by Kato and Torigoe (1977). SCCA is detected in the superficial and intermediate layers of normal squamous epithelium, whereas the mRNA is detected in the basal and subbasal levels. The clinical import of SCCA has been as a circulating tumor marker for squamous cell carcinoma, especially those of the cervix, head and neck, lung, and esophagus. Many clinical studies of cervical squamous cell carcinoma show that the percentage of patients with elevated circulating levels of SCCA increases from approximately 12% at stage 0 to more than 90% at stage IV. Levels fall after tumor resection and rise in approximately 90% of the patients with recurrent disease. Similar trends occur in the other types of squamous cell carcinoma, with a maximum sensitivity of approximately 60% for lung, 50% for esophageal, and 55% for head and neck tumors. The neutral form of SCCA (SCCA1, or SERPINB3) is detected in the cytoplasm of normal and some malignant squamous cells, whereas the acidic form (SCCA2, or SERPINB4) is expressed primarily in malignant cells and is the major form found in the plasma of cancer patients. Thus, the appearance of the acidic fraction of SCCA is correlated with more aggressive tumors (summary by Schneider et al., 1995).

Wikipedia summary for SerpinB4:

Serpin B4 is a protein that in humans is encoded by the SERPINB4 gene.

Human SerpinB4 Protein General Information

 

• Protein names: SerpinB4
• Sequence length: 390 AA.
• Sequence similarities: Belongs to the serpin family. Ov-serpin subfamily.
• Subcellular location: Cytoplasm. Note: Seems to also be secreted in plasma by cancerous cells but at a low level.
• Tissue specificity: Squamous cells.

General information above from UniProt

Function for SerpinB4 Protein

UniProtKB:

SerpinB4 may act as a protease inhibitor to modulate the host immune response against tumor cells.

Genatlas:

• SerpinB4 is serine proteinase inhibitor of cathepsin G and most cell kinase
• SerpinB4 may act as a protease inhibitor to modulate the host immune response against tumor cells
• SerpinB4 may be involved in the malignant behavior of squamous cell carcinoma cells
• with SERPINB3,SerpinB4 stimulates matrix metalloproteinase-9 production in cervical squamous cell carcinoma cell lines
• with SERPINB3, are tumor-associated proteins that can inhibit papain-like cysteine proteases, including cathepsins L, K, and S

Homology for human SerpinB4

• homolog to murine Scca2