Presence of high-molecular-weight forms and domain alterations of fibronectin in pleural effusion of patients with lung cancer

ObjectivesAppearance of fibronectin (FN) molecular forms and alterations of domain expositions can be associated with lung cancer.Design and methodsThe presence of the FN molecular forms and epitopes in its cell-binding, carboxyl-, and amino-terminal domains was determined in the plasma and pleural effusion of patients suffering from small- and non-small-cell lung cancer, and lung inflammation by immunoblotting and FN-ELISA.ResultsThe 320-kDa and 280-kDa FN forms as well as FN fragments appeared in the pleural effusion and plasma of patients suffering from lung inflammation or cancer in significantly higher relative amounts in both lung cancer groups than in the inflammation. The domain concentrations were higher in the cancer and inflammatory plasma groups than those in the control group. The higher N-terminal epitope expression in pleural effusion than in plasma indicates different epitope accessibility for the monoclonal antibody.ConclusionsThe molecular status of FN probably reflects the dynamic changes which occur in cancer and inflammatory tissue.