Keratin, type II cytoskeletal 8 also known as cytokeratin-8 (CK-8) or keratin-8 (K8) is a keratinprotein that is encoded in humans by the KRT8gene. It is often paired with keratin 18.
Antibodies to CK8 (e.g. CAM 5.2) can be used to differentiate lobular carcinoma of the breast from ductal carcinoma of the breast.[5] CAM 5.2, an antibody that reacts with an epitope found on both CK8 and CK18, is used in immunohistochemistry to demonstrate certain forms of cancer. In normal tissue, it reacts mainly with secretory epithelia, but not with squamous epithelium, such as that found in the skin, cervix, and esophagus. However, it also reacts with a range of malignant cells, including those derived from secretory epithelia, but also some squamous carcinomata, such as spindle cell carcinoma. It is considered useful in identifying microscopic metastases of breast carcinoma in lymph nodes, and in distinguishing Paget's disease from malignant melanoma. It also reacts with neuroendocrine tumors.[6]
Keratin 8 is often used together with keratin 18 and keratin 19 to differentiate cells of epithelial origin from hematopoietic cells in tests that enumerate circulating tumor cells in blood.[7]
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Leong, Anthony S-Y; Cooper, Kumarason; Leong, F Joel W-M (2003). Manual of Diagnostic Cytology (2ed.). Greenwich Medical Media, Ltd. pp.177–178. ISBN1-84110-100-1.
Kazerounian, Shideh; Uitto Jouni; Aho Sirpa (October 2002). "Unique role for the periplakin tail in intermediate filament association: specific binding to keratin 8 and vimentin". Exp. Dermatol. 11 (5). Denmark: 428–38. doi:10.1034/j.1600-0625.2002.110506.x. ISSN0906-6705. PMID12366696. S2CID25735126.
Further reading
Moll R, Franke WW, Schiller DL, etal. (1983). "The catalog of human cytokeratins: patterns of expression in normal epithelia, tumors and cultured cells". Cell. 31 (1): 11–24. doi:10.1016/0092-8674(82)90400-7. PMID6186379. S2CID33701361.
Ljubimov AV, Bartek J, Couchman JR, etal. (1992). "Distribution of individual components of basement membrane in human colon polyps and adenocarcinomas as revealed by monoclonal antibodies". Int. J. Cancer. 50 (4): 562–6. doi:10.1002/ijc.2910500412. PMID1371500. S2CID40459741.
Waseem A, Alexander CM, Steel JB, Lane EB (1991). "Embryonic simple epithelial keratins 8 and 18: chromosomal location emphasizes difference from other keratin pairs". New Biol. 2 (5): 464–78. PMID1705144.
Tsubura A, Okada H, Sasaki M, etal. (1991). "Immunohistochemical demonstration of keratins 8 and 14 in benign tumours of the skin appendage". Virchows Archiv A. 418 (6): 503–7. doi:10.1007/BF01606500. PMID1711732. S2CID12052324.
Leube RE, Bosch FX, Romano V, etal. (1987). "Cytokeratin expression in simple epithelia. III. Detection of mRNAs encoding human cytokeratins nos. 8 and 18 in normal and tumor cells by hybridization with cDNA sequences in vitro and in situ". Differentiation. 33 (1): 69–85. doi:10.1111/j.1432-0436.1986.tb00412.x. PMID2434381.
Guelstein VI, Tchypysheva TA, Ermilova VD, etal. (1988). "Monoclonal antibody mapping of keratins 8 and 17 and of vimentin in normal human mammary gland, benign tumors, dysplasias and breast cancer". Int. J. Cancer. 42 (2): 147–53. doi:10.1002/ijc.2910420202. PMID2456993. S2CID30650956.
Osborn M, Mazzoleni G, Santini D, etal. (1988). "Villin, intestinal brush border hydrolases and keratin polypeptides in intestinal metaplasia and gastric cancer; an immunohistologic study emphasizing the different degrees of intestinal and gastric differentiation in signet ring cell carcinomas". Virchows Archiv A. 413 (4): 303–12. doi:10.1007/BF00783022. PMID2459839. S2CID23830197.
Fisher HP, Doppl W, Osborn M, Altmannsberger M (1989). "Evidence for a hepatocellular lineage in a combined hepatocellular-cholangiocarcinoma of transitional type". Virchows Archiv B. 56 (2): 71–6. doi:10.1007/bf02890004. PMID2467436. S2CID24713975.
Gel'shteĭn VI, Chipysheva TA, Ermilova VD, Bannikov GA (1990). "[The expression of keratins Nos. 8, 17 and vimentin in pleomorphic adenoma of the salivary glands]". Arkh. Patol. 51 (10): 28–35. PMID2482017.
Eichbaum QG, Beatty DW, Parker MI (1994). "Identification of cardiac autoantigens in human heart cDNA libraries using acute rheumatic fever sera". J. Autoimmun. 7 (2): 243–61. doi:10.1006/jaut.1994.1019. PMID8037842.
Maruyama K, Sugano S (1994). "Oligo-capping: a simple method to replace the cap structure of eukaryotic mRNAs with oligoribonucleotides". Gene. 138 (1–2): 171–4. doi:10.1016/0378-1119(94)90802-8. PMID8125298.
Suzuki Y, Yoshitomo-Nakagawa K, Maruyama K, etal. (1997). "Construction and characterization of a full length-enriched and a 5'-end-enriched cDNA library". Gene. 200 (1–2): 149–56. doi:10.1016/S0378-1119(97)00411-3. PMID9373149.