Keratin 7

Keratin 7 (KRT7) is a type of keratin, a family of fibrous structural proteins that are critical to the integrity and function of epithelial cells. Keratin 7 is specifically expressed in the cytoplasm of certain types of epithelial cells, playing a pivotal role in maintaining cell structure and facilitating cell signaling and transport. This protein is encoded by the KRT7 gene located on chromosome 12 (12q13.13) in humans.

Function

Keratin 7 is part of the keratin family, which is divided into two main groups: type I (acidic) and type II (basic to neutral). Keratin 7 falls into the type II category. Keratins form intermediate filament networks that provide structural support to epithelial cells and protect them from stress. Keratin 7, in particular, is involved in the structural integrity of glandular epithelia and is a marker for a variety of epithelial cells, including those in the lung, breast, and biliary tract. It is also found in the lining of various internal organs and is critical for the function and repair of these tissues.

Clinical Significance

Keratin 7 is widely used as a diagnostic marker in pathology to identify and differentiate between types of epithelial cancers. Its expression is characteristic of carcinomas originating from or resembling glandular tissue, such as ovarian cancer, breast cancer, lung cancer, and cholangiocarcinoma. The presence or absence of Keratin 7, often in combination with other markers, can help pathologists determine the primary site of a carcinoma, especially in cases of metastatic disease where the origin of the cancer is unknown.

Genetic and Molecular Aspects

The KRT7 gene encodes the Keratin 7 protein. Mutations in this gene are rare but can lead to certain pathologies related to epithelial cell integrity. Research into the genetic regulation of Keratin 7 expression and its role in disease is ongoing, with implications for understanding cancer biology and developing new therapeutic strategies.

See Also

• Keratin
• Epithelial cell
• Protein
• Pathology
• Cancer