Expression of Collagen IV, Fibronectin, Laminin in Non-small Cell Lung Cancer and Its Correlation with Chemosensitivities and Apoptosis

Abstract

Objective: To study the expression of extracellular matrix (ECM) proteins including Collagen IV (Co IV), Fibronectin, Laminin in human non-small cell lung cancer (NSCLC) specimens and the relationship between ECM and cell adhesion, proliferation, apoptosis and drug sensitivity in NSCLC cell line. And to investigate the role of phosphatidylinositol 3-kinase (PI3-K) in signal transduction of Co IV in NSCLC. Methods: The expression of ECM proteins was detected by using immunohistochemical staining (Envision's). Adherent cells were stained with 1% methylene blue. Cell proliferation and cytotoxic effects were monitored by MTT assay. Cell apoptosis was analyzed by FITC-Annexin V/PI double staining variables flow cytometry (FCM). Results: The expression rate of Co IV (93%) was the highest compared to others in NSCLC stroma. After treated with Co IV, the adhesion of H1299 cells was increased and the cytotoxicity of cis-platinum (DDP) against H1299 cells was decreased compared to the control (P<0.05). After treated with Co IV both survival and proliferation rates were higher and apoptosis rate was lower than without Co IV (P<0.05). PI3-K inhibitor LY294002 decreased both survival and proliferation rates (82.7%±2.0% and 75.2%±6.8%, respectively), even on Co IV-coated surface (92.2%±2.8% and 84.6%±9.2%, respectively). And it also helped DDP increase apoptosis. Conclusion: ECM remodeling existed in NSCLC. Co IV protected NSCLC cells from DDP-induced apoptosis and weakened the cytotoxicity of DDP. PI3-K pathway might be the crucial mechanism of apoptosis impairment and drug resistance.