Stimulation of Peritoneal Mesothelial Cells to Secrete Matrix Metalloproteinase-9 (MMP-9) by TNF-α: A Role in the Invasion of Gastric Carcinoma Cells.

It has recently been recognized that inflammatory cytokines, such as tumor necrosis factor-α (TNF-α), upregulate the secretion of matrix metalloproteinase-9 (MMP-9) from cancer cells and thereby promote peritoneal dissemination. In this study, we found that TNF-α also stimulated peritoneal mesothelial cells to secrete MMP-9 as assessed by zymography. MMP-9 gene expression in mesothelial cells induced by TNF-α was confirmed by quantitative RT-PCR analysis.

Potentiation of cell invasion and matrix metalloproteinase production by alpha3beta1 integrin-mediated adhesion of gastric carcinoma cells to laminin-5.

We previously reported that the adhesion of gastric carcinoma cells to the peritoneum mediated by the alpha3beta1 integrin-laminin interaction is a key step in the initial process of peritoneal metastatic dissemination. Carcinoma cells subsequently invade through the intercellular gaps of mesothelial linings. In this study, we examined the role of the interaction of carcinoma cells with laminin-5, which is a major component of submesothelial basement membranes and serves as a high-affinity ligand for alpha3beta1 integrin, in carcinoma cell invasion.

Changes in adhesive and migratory characteristics of hepatocellular carcinoma (HCC) cells induced by expression of alpha3beta1 integrin.

The invasive and metastatic potentials of hepatocellular carcinoma are positively correlated with the expression level of alpha3beta1 integrin, a high-affinity adhesion receptor for laminin isoforms including laminin-5. In this study, we investigated changes in the adhesive and invasive behaviors of human HCC HepG2 cells after transfection with cDNA for alpha3 integrin in order to elucidate the direct involvement of this integrin in these cellular processes. We introduced cDNA for splice variants of alpha3 integrin (alpha3A and alpha3B) into the cells, and selected two transfectant clones (HepG2-3A and HepG2-3B), which express the alpha3A and alpha3B integrins, respectively.

Transforming growth factor-beta1 upregulates transcription of alpha3 integrin gene in hepatocellular carcinoma cells via Ets-transcription factor-binding motif in the promoter region.

The invasive and metastatic potentials of hepatocellular carcinoma (HCC) are positively correlated with the expression level of alpha3beta1 integrin, a high-affinity adhesion receptor for laminin isoforms. Transforming growth factor (TGF)-beta1 stimulates non-invasive HCC cells to acquire invasive phenotypes in association with the enhanced expression of alpha3 integrin. In this study, we investigated the molecular mechanism underlying the upregulation of alpha3beta1 integrin by TGF-beta1 in non-invasive HepG2 HCC cells.

Adhesion of gastric carcinoma cells to peritoneum mediated by alpha3beta1 integrin (VLA-3).

The interaction between gastric carcinoma cells and the peritoneal lining is a key step in peritoneal dissemination. In this study, we examined the roles of the beta1 family of integrin receptors in the adhesion of such cells to the peritoneum. The adhesion of several gastric carcinoma cell lines to peritonea excised from mice was inhibited most by an anti-alpha3 integrin antibody and to a lesser extent by an anti-alpha2 integrin antibody.