Cadherin superfamily of adhesion molecules in primary lung cancer.

Cadherins are Ca(2+-)dependent cell-cell adhesion molecules which interact with intracellular proteins called catenins. Cadherins are the most interesting adhesion molecules and among them most important is epithelial E-cadherin. Loss of the function or/and the expression of any of the elements of E-cadherin/catenins complex make the cell incapable to adhere resulting to a loss of the normal architecture of tissues. Reduced, absent or disorganised expression of E-cadherin has been found in several carcinomas, including lung cancer. Soluble E-cadherin found in serum from patients with lung cancer could be a tumor marker, while alterations observed in non-small cell lung cancer probably play a role in manifestation of a malignant phenotype. Reduced expression of E-cadherin is a key event in tumorgenicity and metastasis and possible therapeutic strategies are based on that conclusion. In addition, E-cadherin has a role as a marker of differential diagnosis between bronchioloalveolar carcinoma and conventional pulmonary carcinoma as well as between mesothelioma and metastatic pulmonary adenocarcinoma. Small cell lung cancer cells express several types of cadherins too. In conclusion, many studies are in process and it is very possible that soon some cadherins will be used as useful biomarkers and theraupeutic targets in cases of primary lung cancer.