The Significance of Nectin Family Proteins in Various Cancerogenous Processes.

Nectins constitute a family of Ca(2+)-independent immunoglobulin-like adhesion molecules. They are involved in cell proliferation, morphogenesis, growth, development, and immune modulation. Due to their broad involvement in physiological processes, extensive research is being conducted on the expression of individual nectins in a variety of cancers and their potential in diagnosis, prognosis, and treatment. The overexpression of nectin-1 may be a poor prognostic factor in gastrointestinal cancers (intestine and pancreas). Similarly, the overexpression of nectin-2 is a worse prognostic factor (greater tumor advancement and shorter patient survival) in cancers such as gallbladder, esophagus, and breast cancer. Changes in nectin-3 expression also affect the advancement of, e.g., colorectal cancer. Additionally, a significant factor here seems to be the change in the localization of nectin-3 expression within cellular structures. The most extensively studied nectin-4 also shows prognostic potential in many cancers. Most often, its high expression correlates with poor prognosis (e.g., gastric cancer), but it may also be a positive prognostic factor, e.g., in salivary gland cancer. Therapy based on nectin-4 is already known and used in the case of urothelial cancers. The expression of nectin-like protein 5 (necl-5) also shows prognostic and therapeutic potential in pancreatic and lung cancers, as well as in multiple myeloma.