Claudin-6 gene is mapped on chromosome 16p13.3 containing 2 exons and is the earliest molecules to be expressed in embryonic stem cells committed to be epithelial fate and the onset of its expression coincides with the expression of the early epithelial marker keratin 8. It is mainly found inembryonic stem cells, primitive germ cell tumors,embryonal carcinoma, choriocarcinoma, yolk sac tumor, classic seminoma, mature teratoma and epithelial lineage cells during early development.
Claudin-6 is predominantly expressed in theliver, peripheral blood mononuclear cells and hepatocarcinoma cell lines as well as expressed particularly in undifferentiated stem cells and used as a marker to filter stem-like cells. It regulates chloride andsodium permeability and boost transepithelial electrical resistance.
Claudin-6 gene mutation is implicated in breast cancer and contributes to the malignant progression of certain types in which reduced expression of claudin-6 encourages cellular invasiveness, transendothelial migration and augments matrix metalloproteinase activity. It is also involved in Hepatitis C virus infection where it mediates the entry into target cells found in the liver.
Gene name: CLDN6
Protein name: Claudin-6