Enhanced migration of tissue inhibitor of metalloproteinase overexpressing hepatoma cells is attributed to gelatinases: Relevance to intracellular signaling pathways

Circulating monocytes associated with anti-PD-1 resistance in human biliary cancer induce T cell paralysis

Suppressive myeloid cells can contribute to immunotherapy resistance, but their role in response to checkpoint inhibition (CPI) in anti-PD-1 refractory cancers, such as biliary tract cancer (BTC), remains elusive. We use multiplexed single-cell transcriptomic and epitope sequencing to profile greater than 200,000 peripheral blood mononuclear cells from advanced BTC patients (n = 9) and matched healthy donors (n = 8). Following anti-PD-1 treatment, CD14+ monocytes expressing high levels of immunosuppressive cytokines and chemotactic molecules (CD14CTX) increase in the circulation of patients with BTC tumors that are CPI resistant. CD14CTX can directly suppress CD4+ T cells and induce SOCS3 expression in CD4+ T cells, rendering them functionally unresponsive. The CD14CTX gene signature associates with worse survival in patients with BTC as well as in other anti-PD-1 refractory cancers. These results demonstrate that monocytes arising after anti-PD-1 treatment can induce T cell paralysis as a distinct mode of tumor-mediated immunosuppression leading to CPI resistance.

Differential gene expression analysis after DAPK1 knockout in hepatocellular carcinoma cells

Background

The mechanism through which death-associated protein kinase 1 (DAPK1) causes hepatocellular carcinoma (HCC) progression remains unclear. In this study, we aimed to identify key proteins that were altered after DAPK1 knockout.

Methods

Stable DAPK1 knockout HCC cell lines were established, then the differentially expressed genes (DEGs) of HCC were screened using the NetworkAnalyst database and enriched using the Metascape software. Protein-protein interaction networks (PPIs) were analyzed and visualized using the STRING database expansion.

Results

In total, 732 differentially expressed genes were identified, including 415 upregulated genes and 317 downregulated genes. Through Cytoscape software scoring, 10 pivotal genes were found to be closely related to changes in DAPK1 expression; Kininogen-1 (KNG1), Complement C3 (C3), Metalloproteinase inhibitor 1 (TIMP1), and Alpha-2-HS-glycoprotein (AHSG) were the most strongly associated with DAPK1 expression changes. Moreover, western blot analysis results revealed that changes in the levels of proteins encoded by the four key genes after DAPK1 knockout were consistent with those seen in the database screening.

Conclusions

These results provide a direction for further studies on the DAPK1 gene and on the mechanism through which DAPK1 leads to hepatocellular carcinoma development.

Metalloproteinases and Their Inhibitors: Potential for the Development of New Therapeutics

The metalloproteinase (MP) family of zinc-dependent proteases, including matrix metalloproteinases (MMPs), a disintegrin and metalloproteases (ADAMs), and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTSs) plays a crucial role in the extracellular matrix (ECM) remodeling and degradation activities. A wide range of substrates of the MP family includes ECM components, chemokines, cell receptors, and growth factors. Metalloproteinases activities are tightly regulated by proteolytic activation and inhibition via their natural inhibitors, tissue inhibitors of metalloproteinases (TIMPs), and the imbalance of the activation and inhibition is responsible in progression or inhibition of several diseases, e.g., cancer, neurological disorders, and cardiovascular diseases. We provide an overview of the structure, function, and the multifaceted role of MMPs, ADAMs, and TIMPs in several diseases via their cellular functions such as proteolysis of other cell signaling factors, degradation and remodeling of the ECM, and other essential protease-independent interactions in the ECM. The significance of MP inhibitors targeting specific MMP or ADAMs with high selectivity is also discussed. Recent advances and techniques used in developing novel MP inhibitors and MP responsive drug delivery tools are also reviewed.

The Role of Matrix Metalloproteinases in the Epithelial-Mesenchymal Transition of Hepatocellular Carcinoma

The epithelial-mesenchymal transition (EMT) is a transformation process mandatory for the local and distant progression of many malignant tumors, including hepatocellular carcinoma (HCC). Matrix metalloproteinases (MMPs) play significant roles in cellular regeneration, programmed death, angiogenesis, and many other essential tissular functions, involved in the normal development and also in pathological processes, such as the EMT. This paper reviews the roles of MMPs in the EMT involved in HCC invasion, as well as the ancillary roles that MMP cross-activation and tissue inhibitors play in modulating this process. While gelatinases MMP-2 and MMP-9 are the MMPs commonly cited in the EMT of HCC, MMPs belonging to other classes have been proven to be involved in this process, favoring not only invasion and metastasis (MMP-1, MMP-3, MMP-7, MMP-10, MMP-11, MMP-13, MMP-14, MMP-16, MMP-26, and MMP-28) but also angiogenesis (MMP-8 and MMP-10). There is also data suggesting that other MMPs with a suspected or demonstrated role in the EMT of other cancers may also have some degree of involvement in HCC. The auto- and cross-activation of MMPs may complicate this issue, as pinpointing the extent of implication of each MMP may be extremely difficult. The homeostasis between MMPs and their tissue inhibitors is essential in preventing tumor progression, and the disturbance of this stability is another entailed factor in the EMT of HCC, which is addressed herein.

Interdependent and independent multidimensional role of tumor microenvironment on hepatocellular carcinoma

The novelty of an effective therapeutic targeting for hepatocellular carcinoma (HCC) is based on improved understanding of each component of tumor microenvironment (TME) and its correspondent interactions at biological and molecular levels. In this context, new expansions for the treatment against TME and its communication with HCC are under exploration. Despite of the fact that blockage of growth factor receptors has become a treatment of choice in late phases of HCC in clinical practice, still a precise targeted treatment should address all the components of TME. Targeting one specific element out of cellular (cancer associated fibroblasts, endothelial cells, hepatic stellate cells, Kupffer cells and lymphocytes) or non-cellular (extracellular matrix, growth factors, inflammatory cytokines, proteolytic enzymes) parts of TME may not be a successful remedy for the disease because of well-designed hindrances of each component and their functional alternativeness. Meanwhile there are some elements of TME like epithelial-mesenchymal transition and CAF, which are considerably important and need thorough investigations. Ascertaining the potential role of these elements, and a single or combinational drug therapy targeting these elements of TME simultaneously, may provide the appreciable considerations to eventually improve in clinical practices and may also minimize the chances of reoccurrence of HCC.

The Inhibitory Effect of C-phycocyanin Containing Protein Extract (C-PC Extract) on Human Matrix Metalloproteinases (MMP-2 and MMP-9) in Hepatocellular Cancer Cell Line (HepG2)

Spirulina platensis :have been studied for several biological activities. In the current study C-phycocyanin containing protein extract (C-PC extract) of Spirulina platensis have been studied for its effect on human matrix metalloproteinases (MMP-1, MMP-2 and MMP-9) and tissue inhibitors of MMPs (TIMP-1 and TIMP-2). In the present study, breast cancer cell line (MDA-MB 231) and hepatocellular cancer cell line (HepG2) were examined for inhibition of MMPs at different levels of expression after C-PC extract treatment. Herein, we have demonstrated that C-PC extract significantly reduced activity of MMP-2 by 55.13% and MMP-9 by 57.9% in HepG2 cells at 15 μg concentration. Additionally, the treatment has reduced mRNA expression of MMP-2 and MMP-9 at 20 μg concentration by 1.65-folds and 1.66-folds respectively. The C-PC extract treatment have also downregulated a mRNA expression of TIMP-2 by 1.12 folds at 20 μg concentration in HepG2 cells. Together, these results indicate that C-PC, extract successfully inhibited MMP-2 and -9 at different levels of expression and TIMP-2 at a mRNA expression level; however, extract did not have any effect on MMP-1 expressed in MDA-MB231 and TIMP-1 expressed in HepG2 cells as well as the exact mechanism of inhibition of MMP-2, MMP-9 and TIMP-2 remained unclear.

The Contribution of Matrix Metalloproteinase-1 Genotypes to Hepatocellular Carcinoma Susceptibility in Taiwan

BACKGROUND/AIM

Metalloproteinases (MMPs) are a family of proteases which have been shown to be overexpressed in various types of cancers. However, the contribution of MMP1 genotype to hepatocellular carcinoma (HCC) has not been well studied. This study aimed to evaluate the contribution of MMP1 promoter 1607 genotype to the risk of HCC in Taiwan, where HCC incidence is relatively high in the world.

MATERIALS AND METHODS

In this case-control study, MMP1 genotype and its interaction with consumption of cigarettes and alcohol in determining HCC risk was investigated among 298 HCC patients and 889 age- and gender-matched healthy controls.

RESULTS

The percentages of ever smokers and ever alcohol drinkers were much higher in the case group than in the control group. The percentages of 2G/2G, 1G/2G and 1G/1G for MMP1 promoter 1607 genotype were 37.2%, 38.3% and 24.5% in the HCC group and 34.8%, 44.0% and 21.2% in the control group, respectively (p for trend=0.2048). The allelic frequency distribution analysis showed the variant 1G allele of MMP1 promoter 1607 conferred similar HCC susceptibility as the wild-type 2G allele (odds ratio (OR)=1.01, 95% confidence interval (CI)=0.84-1.22, p=0.8735). As for the gene-lifestyle interaction, there was an obvious protective effect of MMP1 promoter 1607 1G allele on the risk of HCC among non-smokers, but not non-smokers, even alcohol drinkers or non-drinkers.

CONCLUSION

The 1G allele of MMP1 promoter 1607 may have a protective effect on HCC risk for non-smokers in Taiwan and further validations are needed in other population groups.

Hepatocyte produced matrix metalloproteinases are regulated by CD147 in liver fibrogenesis

BACKGROUND

The classical paradigm of liver injury asserts that hepatic stellate cells (HSC) produce, remodel and turnover the abnormal extracellular matrix (ECM) of fibrosis via matrix metalloproteinases (MMPs). In extrahepatic tissues MMP production is regulated by a number of mechanisms including expression of the glycoprotein CD147. Previously, we have shown that CD147 is expressed on hepatocytes but not within the fibrotic septa in cirrhosis [1]. Therefore, we investigated if hepatocytes produce MMPs, regulated by CD147, which are capable of remodelling fibrotic ECM independent of the HSC.

METHODS

Non-diseased, fibrotic and cirrhotic livers were examined for MMP activity and markers of fibrosis in humans and mice. CD147 expression and MMP activity were co-localised by in-situ zymography. The role of CD147 was studied in-vitro with siRNA to CD147 in hepatocytes and in-vivo in mice with CCl4 induced liver injury using ãCD147 antibody intervention.

RESULTS

In liver fibrosis in both human and mouse tissue MMP expression and activity (MMP-2, -9, -13 and -14) increased with progressive injury and localised to hepatocytes. Additionally, as expected, MMPs were abundantly expressed by activated HSC. Further, with progressive fibrosis there was expression of CD147, which localised to hepatocytes but not to HSC. Functionally significant in-vitro regulation of hepatocyte MMP production by CD147 was demonstrated using siRNA to CD147 that decreased hepatocyte MMP-2 and -9 expression/activity. Further, in-vivo α-CD147 antibody intervention decreased liver MMP-2, -9, -13, -14, TGF-β and α-SMA expression in CCl4 treated mice compared to controls.

CONCLUSION

We have shown that hepatocytes produce active MMPs and that the glycoprotein CD147 regulates hepatocyte MMP expression. Targeting CD147 regulates hepatocyte MMP production both in-vitro and in-vivo, with the net result being reduced fibrotic matrix turnover in-vivo. Therefore, CD147 regulation of hepatocyte MMP is a novel pathway that could be targeted by future anti-fibrogenic agents.

Prognostic value of serum MMP-8, -9 and TIMP-1 in patients with hepatocellular carcinoma

AIM

Prediction of prognosis in hepatocellular carcinoma (HCC) is difficult. The aim of this study was to evaluate the prognostic value of serum MMP-8, -9, -13, and TIMP-1 in patients with HCC.

METHODS

Pre-treatment serum samples from 134 patients with HCC were retrospectively analyzed. The serum concentration of MMP-8 was analyzed with immunofluorometric assay (IFMA), and those of MMP-9, MMP-13, and TIMP-1 were determined by enzyme-linked immunosorbent assays (ELISA). Clinical data were retrieved from patient records and survival data obtained from Statistics Finland.

RESULTS

The overall cumulative disease-specific survival was 69% at 1 year, 50% at 2 years, and 33% at 5 years. Kaplan-Meier overall survival analysis showed that patients with low concentrations of serum MMP-8 or TIMP-1 had a statistically significantly better overall survival than patients with high concentrations of serum MMP-8 or TIMP-1 (P=0.013 and P=0.003). Interestingly, the overall survival in patients with high MMP-9/TIMP-1 ratio was statistically significantly better than in those patients with low MMP-9/TIMP-1 ratio (P=0.004).

CONCLUSION

Our results suggest that serum MMP-8, TIMP-1, and the ratio of MMP-9/TIMP-1 might be useful adjuncts as predictors of prognosis in patients with HCC.

Effects of saikosaponin-d on syndecan-2, matrix metalloproteinases and tissue inhibitor of metalloproteinases-2 in rats with hepatocellular carcinoma

OBJECTIVE

To investigate effects of Saikosaponin D (SSd) on syndecan-2, matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases-2 (TIMP-2) in livers of rat with hepatocellular carcinoma (HCC).

METHODS

Male SD rats were divided into control (n=10), model (n=20) and SSd (n=20) groups, and model and SSd groups given intragastric 0.2% (w/v) N-diethylnitrosamine to induce HCC. SSd group received 0.03% (w/v) SSd in saline. Liver samples were analysed immunohistochemically for syndecan-2, MMP-2, MMP-13 and TIMP-2 at 16 weeks.

RESULTS

The model group had more malignant nodules than the SSd group; all model-group HCC cells were grade III; SSd-group HCC cells were grades I-II. Controls showed normal hepatic cell phenotypes and no syndecan-2+ staining. Syndecan-2+ staining was greater in the model group (35.2%, P < or = 0.001) than in controls or the SSd group (16.5%, P < or = 0.001). The model group had more intense MMP-2+ staining than controls (0.37 vs 0.27, P< or =0.01) or the SSd group (0.31 vs 0.37, P< or =0.05); and higher MMP-13+ staining (72.55%) than in controls (12.55%, P< or =0.001) and SSd group (20.18%, P< or =0.01). The model group also had more TIMP-2+ staining (57.2%) than controls (20.9%, P< or =0.001) and SSd group (22.7%, P< or=0.001). Controls and SSd group showed no difference in TIMP-2+ rates.

CONCLUSION

SSd inhibited HCC development, and downregulated expression of syndecan-2, MMP-2, MMP-13 and TIMP-2 in rat HCC liver tissue.

Inhibitory effect of genistein on the invasive potential of human cervical cancer cells via modulation of matrix metalloproteinase-9 and tissue inhibitors of matrix metalloproteinase-1 expression

BACKGROUND

One of the most challenging stumbling blocks for the treatment of cancer is the ability of cancer cells to break the natural barriers and spread from its site of origin to non-adjacent regional and distant sites, accounting for high cancer mortality rates. Gamut experimental and epidemiological data advocate the use of pharmacological or nutritional interventions to inhibit or delay various stage(s) of cancer such as invasion and metastasis. Genistein, a promising chemopreventive agent, has gained considerable attention for its powerful anti-carcinogenic, anti-angiogenic and chemosensitizing activities.

METHODS

In this study, the cytotoxic potential of genistein on HeLa cells by cell viability assay and the mode of cell death induced by genistein were determined by nuclear morphological examination, DNA laddering assay and cell cycle analysis. Moreover, to establish its inhibitory effect on migration of HeLa cells, scratch wound assay was performed and these results were correlated with the expression of genes involved in invasion and migration (MMP-9 and TIMP-1) by RT-PCR.

RESULTS

The exposure of HeLa cells to genistein resulted in significant dose- and time-dependent growth inhibition, which was found to be mediated by apoptosis and cell cycle arrest at G(2)/M phase. In addition, it induced migration-inhibition in a time-dependent manner by modulating the expression of MMP-9 and TIMP-1.

CONCLUSION

Our results signify that genistein may be an effective anti-neoplastic agent to prevent cancer cell growth and invasion and metastasis. Therefore therapeutic strategies utilizing genistein could be developed to substantially reduce cancer morbidity and mortality.

Expression of matrix metalloproteinase-9 in predicting prognosis of hepatocellular carcinoma after liver transplantation

Matrix metalloproteinases (MMPs) are known to play an important role in cell migration during cancer invasion by degrading extracellular matrix proteins. This study aimed to determine the role of MMP-9 in hepatocellular carcinoma (HCC) carcinogenesis. Eighty-nine cases who underwent liver transplantation for HCC in cirrhotic liver were selected for this study. The tumor characteristics such as nodule number, maximal diameter, portal vein invasion, and the preoperative alpha-fetoprotein levels were reviewed. The intensity of immunostaining and the percentage of immunoreactive cells with MMP-9 were evaluated. All patients were evaluated for HCC recurrence and/or death, and cause of death was noted. There was a lower survival and more recurrence risk among participants with 4 or more nodules exceeding 3 cm in diameter, with poorly differentiated tumor, and with large-vessel involvement. Eleven patients developed recurrent HCC (12.4%). Twelve patients died as a result of HCC (13.5%). Among 89 HCCs, the incidences of a weak (+) and moderate (++) expression of MMP-9 in carcinoma cells were 30.3% (23/89) and 43.8% (39/89), respectively. Increased expression and intensity of MMP-9 were found to be inversely associated with poor tumor differentiation (P = 0.016, P = 0.009, respectively). A significant correlation between expression and intensity of MMP-9 and large vascular invasion (P = 0.01, and P = 0.03) was also observed. As far as prognosis is concerned, increased immunoreactivity and intensity of MMP-9 were found to exert an unfavorable impact on overall survival rates (P < 0.01, P = 0.01, respectively) and recurrences (P = 0.001, P = 0.02). Multivariate analyses revealed that MMP-9 staining percentage (P = 0.007) and portal vein invasion (P = 0.002) were independent predictors of survival, whereas the only independent predictor of recurrences was portal vein invasion (P = 0.007). In this study, our results indicate a positive association between MMP-9 expression and histopathologic parameters that indicate poor prognosis. We conclude that together, MMP-9 staining percentage and portal vein invasion in HCC may aid to predict poor outcome. Nevertheless MMP-9 staining percentage is expected to be a potential predictive marker on survival and needs to be studied more in detail.

Liver expression of matrix metalloproteases and their inhibitors in hepatocellular carcinoma

BACKGROUND

Several studies have suggested the significance of some metalloproteases in the malignant behaviour of hepatocellular carcinoma.

AIMS

To evaluate the liver expression of MMPs and their tissular inhibitors in patients with HCC.

METHODS

An immunohistochemical study using tissue microarrays on samples obtained from 30 HCC patients, with antibodies against MMPs (1, 2, 7, 9, 11, 13 and 14) and TIMPs (1, 2 and 3) was performed. Results were correlated with various clinico-pathological findings and with overall survival.

RESULTS

MMP-1 is mainly expressed by stromal cells, and MMP-13, TIMP-1 and TIMP-2 by inflammatory cells. A positive correlation between MMP-1 expression and larger size tumours (p<0.01) was found. Increased TIMP-2 expression was associated with higher preoperative serum levels of alpha-fetoprotein (p<0.01). Unsupervised hierarchical clustering for total score values designated two groups, one of them characterised by high MMPs and TIMPs expressions, including 21 cases (70%) for tumour cell clustering, 5 cases for fibroblasts (16.6%) and 6 cases for inflammatory cells (20%). All patients showing elevated MMPs and TIMPs expression in stromal cells presented a poor prognosis (p<0.05).

CONCLUSIONS

High liver MMPs and TIMPs expressions in peritumour stromal cells are related to a poorer prognosis in HCC.

Matrigel-induced acinar differentiation is followed by apoptosis in HSG cells

It has been shown that a human salivary gland cell line (HSG) is capable of differentiation into gland-like structures, though little is known of how morphological features are formed or controlled. Here we investigated the changes in cell proliferation and apoptosis upon terminal differentiation of HSG cells in Matrigel, an extracellular matrix derivative. Changes in the expression of survivin, a prominent anti-apoptotic factor, and caspase-3, a key apoptotic factor were also measured. In order to better understand the involvement of key signal transduction pathways in this system we pharmacologically blocked the activity of tyrosine kinase, nuclear factor kappa B(NF kappa B), protein kinase C (PKC), phosphatidylinositol 3-kinase (PI3K) and matrix metalloproteases (MMP). Results of these studies demonstrate that cytodifferentiation of HSG cells to an acinar phenotype is accompanied first by a decrease of cell proliferation and then by a massive programmed cell death, affected by multiple signal transduction pathways. Thus, Matrigel alone is insufficient for the full maturation and long term survival of the newly formed acini: the presence of other factors is necessary to complete the acinar differentiation of HSG cells.

Expression of matrix metalloproteinase-7 and Fas and their significances in gastric carcinoma

AIM: To investigate the expression of matrix metalloproteinase-7 (MMP-7) and Fas in gastric carcinoma as well as their relationships with clinical characteristics.

METHODS: The expression of MMP-7 and Fas proteins were examined with immunohistochemical technique in the specimens from 82 gastric carcinoma tissues and 30 surrounding normal tissues.

RESULTS: The positive rate of MMP-7 expression was significantly higher in gastric carcinoma than that in the normal tissues (73.2% vs 10%, P < 0.05), while the positive rate of Fas expression was marked lower in gastric carcinoma than that in the normal controls (39.1% vs 93.3%, P < 0.001). The expression of MMP-7 was correlated with lymph node metastasis and TMN staging (P < 0.001), but not with the differentiation of tumor cells (P > 0.05). The expression of Fas was correlated with the differentiation of tumor cells (P < 0.05), but was not correlated with lymph node metastasis and TMN staging (P > 0.05). There was a negative correlation between the expression of MMP-7 and Fas in gastric carcinoma (r = -0.597, P < 0.001).

CONCLUSION: The expression of MMP-7 and Fas are closely correlated with the biological behavior of gastric carcinoma. Meanwhile, a negative correlation exists between MMP-7 and Fas expression.

Protection effect of piper betel leaf extract against carbon tetrachloride-induced liver fibrosis in rats

Piper betel leaves (PBL) are used in Chinese folk medicine for the treatment of various disorders. PBL has the biological capabilities of detoxication, antioxidation, and antimutation. In this study, we evaluated the antihepatotoxic effect of PBL extract on the carbon tetrachloride (CCl(4))-induced liver injury in a rat model. Fibrosis and hepatic damage, as reveled by histology and the activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were induced in rats by an administration of CCl(4) (8%, 1 ml/kg body weight) thrice a week for 4 weeks. PBL extract significantly inhibited the elevated AST and ALT activities caused by CCl(4) intoxication. It also attenuated total glutathione S-transferase (GST) activity and GST alpha isoform activity, and on the other hand, enhanced superoxide dismutase (SOD) and catalase (CAT) activities. The histological examination showed the PBL extract protected liver from the damage induced by CCl(4) by decreasing alpha-smooth muscle actin (alpha-sma) expression, inducing active matrix metalloproteinase-2 (MMP2) expression though Ras/Erk pathway, and inhibiting TIMP2 level that consequently attenuated the fibrosis of liver. The data of this study support a chemopreventive potential of PBL against liver fibrosis.

Matrix metalloproteinase-2 (MMP-2) regulates astrocyte motility in connection with the actin cytoskeleton and integrins

Matrix Metalloproteinases (MMPs) play a role in migration of many cell types outside the central nervous system (CNS). Among neural cells, astrocytes are one of the main sources of MMPs in physiological and postlesional conditions. However, no data are available on the possible role of MMPs in astrocyte motility. Using an in vitro model of 2D migration and broad spectrum and selective MMP inhibitors, the authors demonstrated that MMP-2, but not MMP-9, is a key enzyme for astrocyte migration. In support of these data, the authors found constitutive expression of MMP-2 in astrocytes, while MMP-9 was nearly undetectable by gel zymography and immunocytochemical methods. The inhibition of migration by MMP inhibitors correlated with changes in cell morphology and in the organization of the actin cytoskeleton. In parallel, the characteristic focalized distribution of MMP-2 at the migration front observed in control cells became more diffuse and internalized by treatments that inhibited migration. The disruption of actin by cytochalasin D caused the partial recruitment of MMP-2 and gelatinolytic activity into actin aggregates, indicating a connection between the proteinase and the actin cytoskeleton. Finally, the authors found a co-localization of beta1-integrin with MMP-2 at the leading edge of migrating astrocytes. Altogether, these data provide the first evidence for the implication of MMP-2 in astrocyte motility, probably through the interaction of the proteinase with beta1-integrin that could act as a linker between pericellular proteolysis and the actin cytoskeleton.