abstract
- Tumor formation is a complex process which involves constitutive activation of oncogenes and suppression of tumor suppressor genes. Receptor EphA2 and its ligand ephrin-A1 form an important cell communication system with its functional role in cell-cell interaction and tumor growth. Loss of cell-cell adhesion is central to the cellular transformation and acquisition of metastatic potential. Claudins, the integrated tight junction (TJ) cell-cell adhesion proteins located on the apico-lateral portion of epithelial cells, functions in maintaining cell polarity. There is extensive evidence implicating Eph receptors and ephrins in malignancy, but the mechanisms how these molecular players affect TJ proteins and regulate tumor growth are not clear. In the present study we hypothesized that EphA2 signaling modulates claudin-2 gene expression via induction of cdx-2, a tumor suppressor gene in NSCLC cells.