SERPINB3 (SCCA-1)

SERPINB3, also known as SCCA-1, belongs to the serpin family. Serpins are a group of proteins with similar structures that were first identified as a set of proteins able to inhibit proteases. The acronym serpin was originally coined because many serpins inhibit chymotrypsin-like serine proteases. SERPINB3 is expressed in some hepatocellular carcinoma (at protein level). Its expression is closely related to cellular differentiation in both normal and malignant squamous cells. It seems to also be secreted in plasma by cancerous cells but at a low level. SERPINB3 significantly attenuates apoptosis by contrasting cytochrome c release from the mitochondria and by antichemotactic effect for NK cells. It may act as a protease inhibitor to modulate the host immune response against tumor cells and may be involved in the malignant behavior of squamous cell carcinoma cells.

SERPINB3 (SCCA-1) Related Areas

Enzyme>>Protease & Regulator>>Serine Protease & Regulator>>Serpin Superfamily>>SERPINB3 / SCCA-1

SERPINB3 (SCCA-1) Alternative Names

SCCA-PD, SCCA1, T4-A, protein T4-A, serine (or cysteine) proteinase inhibitor, clade B (ovalbumin), member 3, serpin B3, squamous cell carcinoma antigen 1 [Homo sapiens]

Summaries for SERPINB3 (SCCA-1)

OMIM - description for SERPINB3 (SCCA-1):

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 SERPINB3 (SCCA-1):

Serpin B3 is a protein that in humans is encoded by the SERPINB3 gene.

Human SERPINB3 (SCCA-1) Protein General Information

 

• Protein names: SERPINB3
• Sequence length: 390 AA.
• Developmental stage: Its expression is closely related to cellular differentiation in both normal and malignant squamous cells.
• Sequence similarities: Belongs to the serpin family. Ov-serpin subfamily.
• Sequence caution: The sequence AAO11731.1 differs from that shown. Reason: Erroneous initiation.
• Subcellular location: Cytoplasm. Note: Seems to also be secreted in plasma by cancerous cells but at a low level.
• Tissue specificity: Squamous cells. Expressed in some hepatocellular carcinoma (at protein level).

General information above from UniProt

Function for SERPINB3 (SCCA-1) Protein

UniProtKB:

SERPINB3 may act as a protease inhibitor to modulate the host immune response against tumor cells.

Genatlas:

• SERPINB3 is serine proteinase inhibitor of cathepsin S, K and L
• SERPINB3 may act as a protease inhibitor to modulate the host immune response against tumor cells
• SERPINB3 may be involved in the malignant behavior of squamous cell carcinoma cells
• with SERPINB3, stimulates matrix metalloproteinase-9 production in cervical squamous cell carcinoma cell lines
• SERPINB3 plays an important role of SERPINB3 in the modulation of programmed cell death by different mechanisms, both in inflammatory processes and in cancer
• SERPINB3 significantly attenuates apoptosis by contrasting cytochrome c release from the mitochondria and by antichemotactic effect for NK cells
• SERPINB3's anti-protease activity might be implicated in TGF-beta1 induction
• With SERPINB4, SERPINB3 are tumor-associated proteins that can inhibit papain-like cysteine proteases, including cathepsins L, K, and S

Homology for human SERPINB3 (SCCA-1)

• homolog to C.elegans Srp2