Keratin 20, often abbreviated CK20, is a
protein that in humans is encoded by the ''KRT20''
gene.
Keratin 20 is a
type I cytokeratin. It is a major cellular
protein of mature
enterocyte
Enterocytes, or intestinal absorptive cells, are simple columnar epithelial cells which line the inner surface of the small and large intestines. A glycocalyx surface coat contains digestive enzymes. Microvilli on the apical surface increase its ...
s and
goblet cell
Goblet cells are simple columnar epithelial cells that secrete gel-forming mucins, like mucin 5AC. The goblet cells mainly use the merocrine method of secretion, secreting vesicles into a duct, but may use apocrine methods, budding off their secre ...
s and is specifically found in the gastric and intestinal
mucosa
A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It is ...
.
In
immunohistochemistry
Immunohistochemistry (IHC) is the most common application of immunostaining. It involves the process of selectively identifying antigens (proteins) in cells of a tissue section by exploiting the principle of antibodies binding specifically to an ...
, antibodies to CK20 can be used to identify a range of
adenocarcinoma
Adenocarcinoma (; plural adenocarcinomas or adenocarcinomata ) (AC) is a type of cancerous tumor that can occur in several parts of the body. It is defined as neoplasia of epithelial tissue that has glandular origin, glandular characteristics, or ...
arising from
epithelia that normally contain the CK20 protein. For example, the protein is commonly found in
colorectal cancer
Colorectal cancer (CRC), also known as bowel cancer, colon cancer, or rectal cancer, is the development of cancer from the colon or rectum (parts of the large intestine). Signs and symptoms may include blood in the stool, a change in bowel m ...
,
transitional cell carcinomas and in
Merkel cell carcinoma, but is absent in
lung cancer,
prostate cancer
Prostate cancer is cancer of the prostate. Prostate cancer is the second most common cancerous tumor worldwide and is the fifth leading cause of cancer-related mortality among men. The prostate is a gland in the male reproductive system that sur ...
, and non-mucinous
ovarian cancer. It is often used in combination with antibodies to
CK7 to distinguish different types of glandular tumour.
References
Further reading
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Keratins
{{Gene-17-stub