Cytokeratin 17 (BSB-33), MMab

Summary and Explanation

Cytokeratin 17 (CK17) is a mouse monoclonal antibody for immunohistochemistry from Bio SB. Cytokeratin 17 is a Type I cytokeratin with a MW of 46 kD found sometimes in association with Cytokeratin 7. Cytokeratin 17 is found in nail beds, hair follicles, sebaceous glands, and other epidermal appendages. Mutations in the gene encoding this protein lead to Jackson-Lawler type Pachyonychia Congenita and Steatocystoma Multiplex.

Cytokeratin 17 antibody has been used to distinguish immature Cervical Squamous Metaplasia from High Grade Cervical Intraepithelial Neoplasia (CIN III). Anti-CK 17 also labels myoepithelial cells in the benign breast tissue. CK 17 can be useful when included in a panel of antibodies against TTF-1, napsin A, CK 5&6, p63, and SOX-2 for diagnostic differentiation between lung adenocarcinoma (LADC) and lung squamous cell carcinoma (SCLC), especially for poorly-differentiated lung carcinoma. CK 17 is expressed in SCLC much higher than in LADC. In breast carcinomas, approximately 20% of patients show no expression of ER, PR and Her2, which are defined as triple negative tumor. Eighty-five percent of the triple negative breast carcinomas immunoreact with basal cytokeratins including anti-CK 17. The histologic differentiation of ampullary cancer, intestinal vs. pancreatobiliary, is very important for treatment. Usually anti-CK 17 and anti-MUC1 immunoreactivity represents pancreatobiliary subtype whereas anti-MUC2 and anti-CDX-2 positivity defines intestinal subtype.