Protocadherin-18 (PCDH18)

Protocadherin-18 is a member of the cadherin superfamily and classified specifically as a non-clustered δ2-protocadherin. It is a calcium-dependent cell-adhesion molecule containing six extracellular cadherin domains, a transmembrane domain, and a unique cytoplasmic tail. PCDH18 is expressed in various tissues, particularly in the brain, and is involved in the establishment and function of specific cell-cell connections, especially in neural development. In colorectal cancer, PCDH18 functions as a putative tumor suppressor, frequently inactivated through promoter methylation, which makes its epigenetic status a potential biomarker for diagnosis. Its biological activity includes regulation of cell migration, proliferation (through modulation of Wnt/β-catenin signaling), and potentially inhibition of malignant transformation[1][4][3][2][5]. There are currently no known drugs directly targeting PCDH18, and therapeutic approaches or safety concerns remain largely unexplored.

Other names

Protocadherin-18PCDH18KIAA1562PCDH68LProtocadherin 68-like protein

No established mechanism; likely would include modulation of cell adhesion or epigenetic regulation (e.g., demethylating agents restore expression in colorectal cancer models)[1]