About GKN / Gastrokine:
Gastrokine, also known as Gastrokine-1 or GKN1, is a naturally-occurring protein within the human body and is a member of the CCDS set and found in the stomach. The protein of 181-184 amino acids is composed of a hydrophobic signal peptide, a BRICHOS domain, and a COOH-terminal domain.
GKN1 is a protein that helps maintain and regulate gastric homeostasis by suppressing tumors and inhibiting inflammation. It is expressed on the surface mucosa cells located in the gastric antrum and fundus, and is decreased when infected by Helicobacter pylori or suffering from inflammation. As a member of the BRICHOS superfamily of proteins, which includes proteins linked to cancer development, it is additionally found to be downregulated in gastric cancer. The protein has subsequently become a potential theragnostic target for gastric cancer.
In healthy patients, the Gastrokine protein is expressed on the surface of the cells but not at depth. It inhibits the gastrin/cholecystokinin type B receptor while activating both the p16/Rb and p21 signaling pathways leading the cells to senescence. Gastrokine-1 also prevents epithelial gastric cells from developing into cancerous cells by regulating cytokines attributed to the gastric carcinogenesis. It brings an increase to interleukin (IL)-8 and IL-17 and reduction to (NF)-κB, IL-6 and IL-10.
GKN1’s other aliases include AMP18, BRICD1, CA11, FOV, and foveolin. Its Entrez coding is 56287 while its Ensembl genome database project code is ENSG00000169605. It is joined in the gastrokine family by GKN2 and GKN3, with the latter only being found in the previous decade.