ABSTRACT
Hepatocyte growth factor (HGF), a potent cytokine of mesenchymal origin, exhibits polytrophic physiological responses, including proliferation, migration, and invasion, in a wide variety of cells. Although it is known that inhibition of the responses by HGF variants was via signal transducers and activators of the transcription pathway, the mechanisms of action of the variants involved in the production of matrix metalloproteinases (MMPs) were not clearly understood. Thus, recombinant HGF variants, NK1, NK2, NK3, and NK4 were topically applied to assays for proliferation, migration, invasion, and expression of MMPs in the human lung cancer cell line A549 and compared to that of control medium and a glutathione-s-transferase control. Results showed that these recombinant HGF variants significantly inhibited proliferation, migration, and invasion of A549 at >4 nM, downregulated expression of MMP-9, and upregulated expression of MMP-8. The study clearly suggests that binding of the HGF variants to the cell surface c-Met resulted in the downregulation of MMP-9, and upregulation of MMP-8 protein expressions might be key molecular signals against proliferation, migration, and invasion of A549 cells.
Subject(s)
Adenocarcinoma/pathology , Hepatocyte Growth Factor/metabolism , Lung Neoplasms/pathology , Matrix Metalloproteinase 8/metabolism , Matrix Metalloproteinase 9/metabolism , Adenocarcinoma/enzymology , Adenocarcinoma/metabolism , Blotting, Western , Cell Line, Tumor , Cell Proliferation , Escherichia coli/genetics , Glutathione Transferase/metabolism , Hepatocyte Growth Factor/genetics , Humans , Lung Neoplasms/enzymology , Lung Neoplasms/metabolism , Neoplasm Invasiveness , Neoplasm Metastasis , Recombinant Proteins/genetics , Recombinant Proteins/metabolismABSTRACT
OBJECTIVE: To study whether the infection of Schistosomiasis japanicum (S. japanicum) is related to enhanced proliferation and migration of cancer cells, and the molecular mechanism pertains to cancer cell metastasis in human host. METHODS: The gene of S. japanicum glutathione transferase (sjGST) cloned from S. japanicum was expressed, purified and applied in a series of assays to explore the effect of sjGST on proliferation and migration of MDA-MB-435S, and the expression of MMP2 and MMP9. Immunofluorescence assay for the binding of sjGST to MDA-MB-435S was also carried out. RESULTS: Results showed that sjGST enhanced proliferation and migration in human breast cancer cell MDA-MB-435S signifycantly at 50-200 nM, but did not enhance them in human lung cancer cell A549. Immunofluorescence assay for the binding of sjGST to MDA-MB-435S and A549 showed that GST was readily bound to the breast cancer cells, but showed almost no binding to human lung cancer cells. The assays for gelatinase activity showed that both MMP2 and MMP9 activities were increased significantly in the presence of sjGST (50-200 nM) in MDA-MB-435S, but they were not significant in A549. CONCLUSIONS: Our current results show strongly that S. japanicum GST binds to MDA-MB-435S probably via its receptor, and enhances proliferation and migration of the cancer cells by up-regulatory expression of MMP2 and MMP9.
