Keratin 20, often abbreviated CK20, is a protein that in humans is encoded by the KRT20gene.[5][6][7]
Keratin 20 is a type I cytokeratin. It is a major cellular protein of mature enterocytes and goblet cells and is specifically found in the gastric and intestinal mucosa.[8]
In immunohistochemistry, antibodies to CK20 can be used to identify a range of adenocarcinoma arising from epithelia that normally contain the CK20 protein. For example, the protein is commonly found in colorectal cancer, transitional cell carcinomas and in Merkel cell carcinoma, but is absent in lung cancer, prostate cancer, and non-mucinous ovarian cancer. It is often used in combination with antibodies to CK7 to distinguish different types of glandular tumour.[9]
Micrograph showing CK20 immunostaining of normal small intestine.
^"Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
^"Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
^Moll R, Zimbelmann R, Goldschmidt MD, Keith M, Laufer J, Kasper M, Koch PJ, Franke WW (June 1993). "The human gene encoding cytokeratin 20 and its expression during fetal development and in gastrointestinal carcinomas". Differentiation. 53 (2): 75–93. doi:10.1111/j.1432-0436.1993.tb00648.x. PMID8359595.
^Ye X, Li Y, Hou G, Liu Z, Chen T (May 2002). "[Significance of cytokeratin gene (CK-20 mRNA) expression in metastatic lymph nodes in colon carcinoma patients]". Zhonghua Zhong Liu Za Zhi (in Chinese). 24 (3): 261–3. PMID12515621.
^Leong, Anthony S-Y; Cooper, Kumarason; Leong, F Joel W-M (2003). Manual of Diagnostic Cytology (2 ed.). Greenwich Medical Media, Ltd. pp. 171–172. ISBN1-84110-100-1.
Further reading[]
Nordgírd O, Oltedal S, Kørner H, et al. (2009). "The potential of cytokeratin 20 and mucin 2 mRNA as metastasis markers in regional lymph nodes of colon cancer patients investigated by quantitative RT-PCR". Int J Colorectal Dis. 24 (3): 261–8. doi:10.1007/s00384-008-0613-y. PMID19119477. S2CID10831713.
Wong CS, Cheung MT, Ma BB, et al. (2008). "Isolated tumor cells and circulating CK20 mRNA in pN0 colorectal cancer patients". Int. J. Surg. Pathol. 16 (2): 119–26. doi:10.1177/1066896907311901. PMID18387990. S2CID29407811.
Nishigami T, Onodera M, Torii I, et al. (2009). "Comparison between mucinous cystic neoplasm and intraductal papillary mucinous neoplasm of the branch duct type of the pancreas with respect to expression of CD10 and cytokeratin 20". Pancreas. 38 (5): 558–64. doi:10.1097/MPA.0b013e31819f3bd6. PMID19287335. S2CID30111257.
Saad RS, Silverman JF, Khalifa MA, Rowsell C (2009). "CDX2, cytokeratins 7 and 20 immunoreactivity in rectal adenocarcinoma". Appl. Immunohistochem. Mol. Morphol. 17 (3): 196–201. doi:10.1097/PAI.0b013e31819268f2. PMID19098678. S2CID37115618.
González JJ, Bernardo CG, Sanz L, et al. (2007). "Mismatch repair protein MSH2, cytokeratin 18 and cytokeratin 20 expression: clinicopathological correlation and prognostic value in colorectal cancer patients". Hepatogastroenterology. 54 (80): 2266–71. PMID18265645.
Koga T, Tokunaga E, Sumiyoshi Y, et al. (2008). "Detection of circulating gastric cancer cells in peripheral blood using real time quantitative RT-PCR". Hepatogastroenterology. 55 (84): 1131–5. PMID18705345.
D'Armento G, Daniele L, Mariani S, et al. (2009). "Added value of combined gene and protein expression of CK20 and CEA in non-macroscopically involved lymph nodes of colorectal cancer". Int. J. Surg. Pathol. 17 (2): 93–8. doi:10.1177/1066896908328574. PMID19074466. S2CID3123711.
Eissa S, Zohny SF, Swellam M, et al. (2008). "Comparison of CD44 and cytokeratin 20 mRNA in voided urine samples as diagnostic tools for bladder cancer". Clin. Biochem. 41 (16–17): 1335–41. doi:10.1016/j.clinbiochem.2008.08.085. PMID18804101.
He H, Fang W, Liu X, et al. (2009). "Frequent expression of glypican-3 in Merkel cell carcinoma: an immunohistochemical study of 55 cases". Appl. Immunohistochem. Mol. Morphol. 17 (1): 40–6. doi:10.1097/PAI.0b013e31817b67d1. PMID18813128. S2CID1735166.
Stenling R, Lindberg J, Rutegírd J, Palmqvist R (2007). "Altered expression of CK7 and CK20 in preneoplastic and neoplastic lesions in ulcerative colitis". APMIS. 115 (11): 1219–26. doi:10.1111/j.1600-0643.2007.00664.x. PMID18092953. S2CID36381220.
Takano K, Kojima T, Ogasawara N, et al. (2008). "Expression of tight junction proteins in epithelium including Ck20-positive M-like cells of human adenoids in vivo and in vitro". J. Mol. Histol. 39 (3): 265–73. doi:10.1007/s10735-008-9162-5. PMID18246436. S2CID10932276.
Lagoudianakis EE, Kataki A, Manouras A, et al. (2009). "Detection of epithelial cells by RT-PCR targeting CEA, CK20, and TEM-8 in colorectal carcinoma patients using OncoQuick density gradient centrifugation system". J. Surg. Res. 155 (2): 183–90. doi:10.1016/j.jss.2007.10.013. PMID19645077.
Qiao JL, Meng XK, Zhang JJ, et al. (2009). "[Expression of CK20 mRNA in the peripheral blood around postoperative chemotherapy in patients with gastric cancer and its clinical significance]". Zhonghua Wei Chang Wai Ke Za Zhi. 12 (1): 32–5. PMID19145500.