The Study On The Effect Of Thrombin In Neo-small Cell Lung Carcinoma (A549) In Vitro

Objective: To study thrombin for cell proliferation and the up-regulation of vascular endothelial growth factor ( VEGF ) and inhibition of cisplatin (PDD)-induced cell apoptosis on the human neo-small cell lung cancer cells line A549 in vitro, and explore its mechanism. Methods: Cell proliferation in different concentration and time was determined by improved MTT colorimetric assay. The fluorescence flow cytometry (FCM) DNA assay was applied to detect the changes of apoptotic rate .The enzyme linked immunosorbent assay (ELISA) was used to evaluate the role of thrombin on the expression of vascular endothelial growth factor in A549 and inhibition of hirudin. Reverse transcriptase-polymerase chain reaction analysis (RT-PCR) showed presentation of thrombin receptor (PAR-1) mRNAs. Results: Thrombin may increase the cell proliferation in 0.5-1.5 u/ml concentrations and the secretion of VEGF in A549 cell in 0.5-3u/ml concentrations. The induction of VEGF was significantly blocked by the thrombin inhibitor hirudin. Reverse transcriptase polymerase chain reaction demonstrated thrombin receptor expression in A549 cell and not in human embryon lung cell(KMB-17). Conclusions: Thrombin may substantially stimulate the cell proliferation and the secretion of VEGF and change PDD-induced cell apoptotic rate in A549 cell in vitro. The mechanisms of induction are mainly that PAR-1 expressed in human neo-small lung carcinoma.