Cytokeratin 8

Cytokeratin 8 (CK8) is a low molecular weight alkaline keratin that mainly exists in glandular epithelium and transitional epithelium. It has various functions such as maintaining morphology, regulating proliferation, and mediating migration. In clinical practice, CK8 is an effective indicator to differentiate adenocarcinoma and squamous cell carcinoma. It has been widely used in the diagnosis of lung adenocarcinoma, pancreatic cancer, breast cancer, ovarian cancer, endometrial cancer and other adenocarcinoma tissues. Moreover, CK8 is positively correlated with the malignancy of tumors, which may be because it is accompanied by abnormal activation of the NF-κB pathway to trigger inflammatory response, and can promote basal membrane degradation and tumor angiogenesis by binding to plasminogen. However, CK8 is expressed in laryngeal squamous cell carcinoma, which is considered as a poor prognostic indicator for patients, speculated that the excessive production of CK8 can alter cell surface features to induce malignant transformation. In addition, some scholars pointed out that the low expression of CK8 in colorectal cancer can stimulate epithelial-mesenchymal transition (EMT) to enhance tumor invasiveness.