Paradoxical Pro-invasive Effect of the Serine Proteinase Inhibitor Tissue Factor Pathway Inhibitor-2 on Human Hepatocellular Carcinoma Cells

Abstract

We have previously shown that human liver myofibroblasts promote in vitro invasion of human hepatocellular carcinoma (HCC) cells through a hepatocyte growth factor (HGF)/urokinase/plasmin-dependent mechanism. In this study, we demonstrate that myofibroblasts synthesize the serine proteinase inhibitor tissue factor pathway inhibitor-2 (TFPI-2). Despite the fact that recombinant TFPI-2 readily inhibits plasmin, we show that it potentiates HGF-induced invasion of HCC cells and is capable of inducing invasion on its own. Furthermore, HCC cells stably transfected with a TFPI-2 expression vector became spontaneously invasive. HCC cells express tissue factor and specifically factor VII. Addition of an antibody to factor VII abolished the pro-invasive effect of TFPI-2. We suggest that TFPI-2 induces invasion following binding to a tissue factor-factor VIIa complex preformed on HCC cells. Our data thus demonstrate an original mechanism of cell invasion that may be specific for liver tumor cells.Hepatocellular carcinoma (HCC) 1 is one of the most frequent primary tumors in the world (1). It is a major complication of liver cirrhosis, although more rarely it will develop on a noncirrhotic liver. HCC are characterized by a high rate of local, intra-hepatic invasion. HCC are infiltrated by myofibroblastlike cells, located around tumoral sinusoids and in fibrous septa and capsule, when present (2-4). We have previously shown that cultured human liver myofibroblasts strongly promoted in vitro invasion of human HCC cell lines through their secretion of hepatocyte growth factor (HGF) (5). In further studies, we showed that HGF induced invasion by increasing the expression of the urokinase-type plasminogen activator (uPA) by the cancer cells (6). Indeed, myofibroblast-or HGFinduced invasion was dose-dependently blocked by a selective uPA antagonist (6). One of the main functions of uPA is to convert the inactive zymogen plasminogen into plasmin, a broad-spectrum proteinase able to degrade several components of the extracellular matrix and thus a likely effector of cancer cell invasion.Tissue factor pathway inhibitor-2 (TFPI-2), also known as placental protein 5 is a serine proteinase inhibitor containing 3 tandemly arranged Kunitz-type proteinase inhibitor domains, homologous to tissue factor pathway inhibitor (7). TFPI-2 exists as 3 isoforms of 27, 31, and 33 kDa that are synthetic products of a single gene and arise from differential glycosylation. TFPI-2 is a strong inhibitor of plasmin as well as of trypsin, plasma kallikrein, and factor XIa. It does not inhibit uPA (8). TFPI-2 synthesis has been described in dermal fibroblasts and endothelial cells (9 -11). In these cell types, the major part of TFPI-2 is sequestered within the extracellular matrix (ECM), presumably bound to heparan sulfate. In the course of a systematic sequencing of a human liver myofibroblast cDNA library described elsewhere (12), we found that these cells expressed transcripts for TFPI-2. Given the ability of TFPI-2 to inhibit plasmin, we were interest...

Sequential 5-Aza 2′-deoxycytidine/depsipeptide FK228 treatment induces tissue factor pathway inhibitor 2 (TFPI-2) expression in cancer cells

“…Whereas the role of TFPI-2 in thoracic malignancies has not been systematically evaluated, Lakka et al (2000) observed that antisense to TFPI-2 enhances migration and invasiveness of A549 lung cancer cells in vitro. Although these observations suggest that TFPI-2 inhibits the malignant phenotype of cancer cells of diverse histologies, recent experiments by Neaud et al (2000) as well as Shinoda et al (1999) have shown that TFPI-2 is a potent mitogen for hepatocarcinoma as well as vascular smooth muscle cells. Collectively, these data indicate that the effects of TFPI-2 in cancer cells may be highly complex, and tissue specific.…”

A novel function of tissue factor pathway inhibitor-2 (TFPI-2) in human glioma invasion

“…Tissue factor also upregulated the production of vascular endothelial cell growth factor (Ollivier et al, 1998) and uPAR (Taniguchi et al, 1998) in tumor cells, and its levels perfectly correlated with the degree of tumor angiogenesis and progression in ®brosarcomas, melanomas, breast and pancreatic tumors (Contrino et al, 1996;Mueller et al, 1992;Nakagawa et al, 1998;Mueller and Ruf, 1998). Recently it was reported (Neaud et al, 2000) that human liver myo®broblasts promote in vitro invasion of human hepatocellular carcinoma (HCC) cells through a hepatocyte growth factor (HGF)/urokinase/plasmin-dependent mechanism. Myo®broblasts also synthesize the serine proteinase inhibitor tissue factor pathway inhibitor-2 (TFPI-2).…”

Microarray analysis reveals differential gene expression patterns and regulation of single target genes contributing to the opposing phenotype of TrkA- and TrkB-expressing neuroblastomas

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