Overexpression of MMP14 predicts the poor prognosis in gastric cancer: Meta-analysis and database validation

BACKGROUND

Plenty of studies have showed matrix metalloproteinase 14 (MMP14) expression might be associated with the prognosis of gastric cancer (GC). However, no definite conclusion has been obtained for the contradictory results.

METHODS

We searched PubMed, Web of science, Embase, and Cochrane library for eligible studies. The association between MMP14 expression and prognostic outcomes of GC was evaluated. Hazard ratio (HR) and 95% confidence interval (CI) were integrated to show the effect of MMP14 expression on the overall survival (OS) or recurrence-free survival (RFS). Data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) was used to validate the association of MMP14 expression with OS or RFS in GC. A brief bioinformatics analysis was also performed to determine the prognostic role of MMP14 expression in GC.

RESULTS

High MMP14 expression was associated with shorter OS compared to low MMP14 expression in GC (HR = 1.95, P < .01). Patients with high MMP14 expression tended to have worse differentiation (P = .03), deeper tumor invasion (P < .01), earlier lymph node metastasis (P < .01), earlier distant metastasis (P < .01) and more advanced clinical stage (P < .01) compared to those with low MMP14 expression. The data from TCGA and GEO showed MMP14 was overexpressed in tumor tissues compared to normal tissues (P < .05), and high MMP14 expression was significantly related to shorter OS (HR = 1.70, 95% CI = 1.32-2.20, P < .01) and RFS (HR = 1.45, 95% CI = 1.15-1.83, P < .01) compared to low MMP14 expression in GC. Expression of MMP14 was linked to functional networks involving the biological process, metabolic process, response to stimulus, cell communication and so on. Functional network analysis suggested that MMP14 regulated the protein digestion and absorption, extracellular matrix receptor interaction, focal adhesion, ribosome, spliceosome, and so on.

CONCLUSION

High MMP14 expression was associated with worse prognosis of GC compared to low MMP14 expression. MMP14 expression could serve as a prognostic factor and potential therapeutic target of GC.

Immunohistochemical Profiles of Matrix Metalloproteinases and Vascular Endothelial Growth Factor Overexpression in the Antoni B Area of Vestibular Schwannomas

OBJECTIVE

To evaluate the clinical manifestations of cystic vestibular schwannomas (VSs), investigate the immunohistochemical profiles of matrix metalloproteinases (MMPs) and vascular endothelial growth factor (VEGF) expression in Antoni A and B areas, and speculate the pathogenesis of cystic formation and intratumoral hemorrhage.

METHODS

Clinical features and outcomes of 24 cases of cystic VSs and 38 cases of solid VSs were retrospectively compared. Immunohistochemical studies were conducted to evaluate the characteristics of MMPs and VEGF in cystic and solid VSs.

RESULTS

The tumor size was 38.92 ± 1.86 mm and 31.95 ± 1.74 mm in the cystic and solid VSs group, respectively (P = 0.011). Cystic VSs were rich in the Antoni B area. MMP-9 expression was low in the Antoni A and B areas. MMP-2 was moderately expressed. No significant difference in MMP-2 expression existed between the Antoni A and B areas (P > 0.05). VEGF and MMP-14 expression were moderate in the Antoni A area and intense in the Antoni B area, and the expression of both was significantly greater in the Antoni B area than in the Antoni A area (P < 0.001).

CONCLUSIONS

MMP-14 and VEGF expression were significantly greater in the Antoni B area than in the Antoni A area. Upregulated MMP-14 may degrade loose collagen in the Antoni B area and contribute to cystic formation. MMP-14 can enhance VEGF activity, which may induce extravasation of a plasma ultrafiltrate, cystic expansion, and intratumoral hemorrhage. Therefore, MMP-14 inhibition may be a therapeutic strategy for treating cystic VSs.

High expression of MMP14 is associated with progression and poor short-term prognosis in muscle-invasive bladder cancer

OBJECTIVE

To evaluate the short-term prognostic value of matrix metalloproteinase 14 (MMP14) in muscle-invasive bladder cancer (MIBC).

PATIENTS AND METHODS

Expression of MMP14 and clinical information from The Cancer Genome Atlas (TCGA) were mined in MIBC patients to analyse expression differences and conduct survival analyses. The mRNA and protein expression levels of MMP14 in other tumours were analysed using Gene Expression Profiling Interactive Analysis (GEPIA) and The Human Protein Atlas. The expression level of MMP14 in bladder cancer (BC) cell lines and clinical samples and its clinical significance were indicated using quantitative Real Time-Polymerase Chain Reaction (qRT-PCR), Western blotting, and immunohistochemistry. The biological functions of MMP14 were investigated by examining cell migration using in vitro wound-healing assays and cell invasion using transwell invasion assays. Survival analyses were conducted with the collected clinical follow-up data.

RESULTS

Our study revealed that MMP14 is highly expressed in MIBC based, on both TCGA derived data and our clinical tissues (p<0.05). MMP14 is also highly expressed in head and neck cancer, renal cancer, pancreatic cancer and other cancers, as analysed using GEPIA and The Human Protein Atlas (p<0.05). Survival analyses of the TCGA data and our clinical follow-up data revealed high expression of MMP14 indicates a poor short-term prognosis in MIBC (p<0.05). Furthermore, downregulation of MMP14 suppressed BC cell invasion and migration abilities in vitro. MMP14 expression was closely correlated with tumour metastasis (p<0.05). T stage [hazard ratio (HR)=1.412, 95% confidence interval (CI)=1.121-1.779, p=0.003] and metastasis (HR=2.256, 95% CI=1.242-4.100, p=0.008) were unfavourable prognostic factors in BC patients.

CONCLUSIONS

In MIBC, MMP14 expression is upregulated and closely associated with disease progression and poor short-term prognosis.

Neurokinin-1 receptor mediated breast cancer cell migration by increased expression of MMP-2 and MMP-14

Breast cancer (BC) is a common reason of cancer-associated death in female. To develop novel strategy of therapeutics, it is crucial to comprehensively understand the receptor status of BC cells on the surface and inner, because chemical messengers can bind the receptors and promote tumorigenesis. Compared with normal and benign samples, BC cell lines and malignant biopsies showed higher expression of neurokinin-1 receptor (NK1). In current work, we examined the role and mechanism of NK1 receptor signaling in BC cell migration. Human hemokinin-1 (hHK-1) was the peripheral agonist of NK1 receptor. Our results showed that by activating NK1 receptor, hHK-1 promoted the migration of BC cells. Gelatin zymography and WB experiment showed that hHK-1 enhanced the levels of MMP-2 and MMP-14; inhibition of these two MMPs blocked hHK-1-induced cell migration. We further explored the underlying mechanism. hHK-1 incuced the phosphorylation of ERK1/2, JNK and Akt through PKC or PKA pathway. The phosphorylation of these kinases further regulated the activation of transcriptional factor AP-1 and NF-κB. Inhibition of AP-1 and NF-κB reduced the up-regulation of MMP-2 and MMP-14 by hHK-1. Taken together, we showed NK1 receptor was an important regulator of human BC cell migration and a potential target for BC treatment.

Decreased MT1-MMP in gastric cancer suppressed cell migration and invasion via regulating MMPs and EMT

Membrane type 1-matrix metalloproteinase (MT1-MMP) has been identified to play a significant role in several types of cancers, but little is known about the significance of MT1-MMP in gastric cancer patients. The purpose of this study is to investigate the involvement of MT1-MMP in tumor progression of gastric cancer. MT1-MMP expression levels were examined in gastric cancer tissues and cells, and normal gastric tissues and cells. The effects and molecular mechanisms of MT1-MMP expression on cell proliferation, migration, and invasion were also explored. In our results, MT1-MMP messenger RNA (mRNA) and protein expression levels were significantly increased in gastric cancer tissue. Moreover, the overexpression of MT1-MMP was positively associated with the status of clinical stage and lymph node metastasis through real-time PCR. Furthermore, knocking down MT1-MMP expression significantly suppressed the cell migration and invasion in vitro and regulated the expression of MMPs and epithelial-mesenchymal transition (EMT)-associated genes. In conclusions, our study demonstrates that MT1-MMP was overexpressed in gastric cancer tissue, and reduced expression of MT1-MMP suppressed cell migration, invasion, and through regulating the expression of MMPs and the process of EMT in gastric cancer.

Matrix Metalloproteinase 14 Overexpression Is Correlated with the Progression and Poor Prognosis of Nasopharyngeal Carcinoma

BACKGROUND AND AIMS

Matrix metalloproteinase 14 (MMP14) has been identified to play a significant role in several types of cancers, but little is known about the significance of MMP14 in nasopharyngeal carcinoma (NPC) patients. The aim of this study was to explore the association of MMP14 expression with clinicopathologic features and prognosis in NPC.

METHODS

MMP14 mRNA and protein expressions were examined in NPC and nasopharyngeal tissues through real-time PCR and immunohistochemistry. Meanwhile, the relationship of MMP14 expression levels with clinical features and prognosis of NPC patients was analyzed.

RESULTS

MMP14 mRNA expression was markedly higher in NPC tissues than in nasopharyngeal epithelium tissues (p = 0.002). Using immunohistochemistry, staining for MMP14 protein was found in the normal nasopharyngeal epithelial cells and malignant epithelial cells, but increased expression of MMP14 was observed in NPC samples compared with normal nasopharyngeal epithelium samples (p = 0.027). In addition, high levels of MMP14 protein were positively correlated with the status of clinical stage (p = 0.009), N classification (p = 0.006), and distant metastasis (p = 0.005) of NPC patients. Patients with higher MMP14 expression had a significantly shorter overall survival time than did patients with low MMP14 expression. Multivariate analysis indicated that the level of MMP14 expression was an independent prognostic indicator (p < 0.001) for the survival of patients with NPC.

CONCLUSIONS

MMP14 overexpression is a potentially unfavorable prognostic factor for NPC patients.

Anti-tumor effect and mechanism of cyclooxygenase-2 inhibitor through matrix metalloproteinase 14 pathway in PANC-1 cells

OBJECTIVE

To investigate whether celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, can attenuate proliferation, migration, invasion and MMP-14 expression in pancreatic cancer cells PANC-1 and the possible anti-tumor mechanism of celecoxib.

METHODS

Human pancreatic cancer cell line PANC-1 cells were treated with diverse concentrations of celecoxib (20, 60, 100 μmol/L). Cell proliferation, invasion and migration capabilities were measured by MTT colorimetry, transwell invasion assay, and scratch assay separately. At the same time, the protein expression of COX-2 and MMP-14 was assessed by ELISA.

RESULTS

The capabilities of proliferation, invasion and migration in PANC-1 cells were attenuated in a concentration-dependent manner after treated with celecoxib, followed by the down-regulation of the protein expression of COX-2 and MMP-14. In addition, MMP-14 expression was significantly positively correlated with COX-2 expression.

CONCLUSIONS

COX-2 inhibitor celecoxib can inhibit the proliferation, invasion and migration of PANC-1 cells via down-regulating the expression of MMP-14 in a concentration-dependent manner, thus contributing to its anti-tumor effect in pancreatic cancer.

miR-150-5p inhibits hepatoma cell migration and invasion by targeting MMP14

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related mortality worldwide. Despite progress in diagnostics and treatment of HCC, its prognosis remains poor because the molecular mechanisms underlying hepatocarcinogenesis are not well understood. In the study, we focused on identifying the role of miRNAs in HCC progression. miRNA microarray was used to analyze the differentially expressed miRNAs, and the results were validated by qPCR. We found that the miR-150-5p expression is down-regulated in HCC tissues compared with pair non-tumor tissues. miR-150-5p expression is also decreased in metastatic cancer tissues compared with pair primary tissues, indicating that miR-150-5p may be involved in HCC metastasis. Functionally, miR-150-5p inhibition significantly promotes hepatoma cell migration and invasion, whereas miR-150-5p overexpression suppresses cancer cell migration and invasion invitro. The matrix metalloproteinase 14 (MMP14) is identified as a new target gene of miR-150-5p. miR-150-5p markedly inhibits MMP14 expression in hepatoma cells, and miR-150-5p expression is negative correlation with MMP14 expression invivo. More important, re-expression of MMP14 in hepatoma cells partially reverses the effect of miR-150-5p in inhibiting cell invasion.

[Key enzymes of degradation and angiogenesis as a factors of tumor progression in squamous cell carcinoma of the cervix]

A key role in tumor progression play two processes--the destruction and angiogenesis. Matrix metalloproteases (MMPs) play a leading role during tissue degradation. Tissue collagenase--MMP-1 and MT1-MMP hydrolyze fibrillar collagens, which are the basis of connective tissue matrix, and ensure the development of an invasive process. Gelatinase A and B (MMP-2 and MMP-9) hydrolyze collagen type IV, which is the basis of the basal membrane, and facilitate the development of metastasis. Endogenous tissue inhibitors TIMP-1 and TIMP-2 are involved in the regulation of MMP expression and activity. It has been established that MMP-9 release vascular endothelial growth factor (VEGF) associated with the STM--the primary inductor angiogenesis. Angiotensin-converting enzyme (ACE) participates in the induction of VEGF synthesis. ACE--a key enzyme of the renin-angiotensin system, forms angiotensin II, which interactes with the receptor ATIR and induces VEGF synthesis, as well as stimulates endothelial cell proliferation. Our experimental studies devoted to the study of particularity expression of key enzymes of destruction and angiogenesis in squamous cell carcinoma of the cervix (SCC). It was studied: MMP-1, MT1-MMP, MMP-2 and MMP-9 and their endogenous regulators: TIMP-1, TIMP-2, and as well as ACE. Work was performed on clinical specimens containing the tumor tissue, taking into account the presence or absence of metastasis to regional lymph nodes and the specimens of adjacent morphologically normal tissue. It was shown that the increase of MMP-1, MT1-MMP and MMP-9 expression and low of TIMP-1 and TIMP-2 expression makes the main contribution to the destructive (invasive) potential of SCC. The change of MMP-2 expression is not so significant and it is less influenced to the destructive potential. It was shown dramatic increasing of MMP-1 and MMP-9 activity in metastasizing tumor tissue ACE activity in a tumor in most of the samples was higher than the activity in normal tissues. It was established that the expression of key enzymes degradation and angiogenesis occurs not only in tumor but also in normal tissues. Data are important for understanding the mechanisms of tumor progression and have prognostic value and may affect the therapeutic strategy for patients.

MicroRNA-24 regulates macrophage behavior and retards atherosclerosis

OBJECTIVE

Our recent studies have highlighted membrane type-1 matrix metalloproteinase (MMP)-14 as a selective marker for an invasive subset of macrophages potentially related to atherosclerotic plaque progression. Moreover, colony stimulating factors (CSF) may exert divergent effects on macrophage MMP expression, possibly through microRNAs. We, therefore, aim to identify and test the pathophysiological role of microRNAs, which modulate macrophage MMP-14 expression in atherosclerotic plaque progression.

APPROACH AND RESULTS

Compared with macrophage CSF-differentiated macrophages, granulocyte/macrophage CSF-matured macrophages exhibited reduced MMP-14 mRNA levels but increased protein expression and activity, which resulted in heightened macrophage invasion. MicroRNA-24, identified to target MMP-14, was accordingly increased in macrophage CSF compared with granulocyte/macrophage CSF macrophages. Silencing microRNA-24 in macrophage CSF macrophages significantly increased MMP-14 expression and enhanced their invasive capacity, mimicking granulocyte/macrophage CSF macrophages, and suggesting that granulocyte/macrophage CSF modulates MMP-14 protein expression and subsequent macrophage invasion in a microRNA-24-dependent manner. In human coronary atherosclerotic plaques, increased MMP-14 protein expression in foam cell macrophages was associated with lesions exhibiting histological characteristics associated with an unstable phenotype. Furthermore, microRNA-24 expression in these atherosclerotic plaques was inversely related to MMP-14 protein expression. Moreover, stable plaques contained higher microRNA-24 levels than unstable plaques, and microRNA-24 colocalized with foam cell macrophages that exhibited low MMP-14 protein expression. Finally, in atherosclerotic mice (apolipoprotein E-deficient), microRNA-24 inhibition increased plaque size and macrophage MMP-14 expression.

CONCLUSIONS

Taken together, our data demonstrates that downregulation of microRNA-24 promotes an invasive macrophage subset and plays a novel regulatory role in MMP-14 proteolytic activity and, therefore, plaque stability, highlighting its therapeutic potential.

MMP-14 overexpression correlates with poor prognosis in non-small cell lung cancer

Matrix metalloproteinase-14 (MMP-14) has been demonstrated to play an important role in tumor progression. The aim of this study was to analyze the correlation between MMP-14 expression and clinicopathologic features and its prognostic significance in non-small cell lung cancer (NSCLC). Immunohistochemical staining for MMP-14 protein was performed in 104 patients with NSCLC. High levels of MMP-14 protein were positively correlated with the status of clinical stage (I-II vs. III-IV; P < 0.001), N classification (N0-N1 vs. N2-N3; P < 0.001), distant metastasis (no vs. yes; P = 0.014), and differentiated degree (high vs. low or undifferentiated; P = 0.001). The patients with higher MMP-14 expression of protein had shorter survival time than patients with low MMP-14 expression. Multivariate analysis indicated that the level of MMP-14 expression was an independent prognostic indicator (P < 0.001) for the survival of patients with NSCLC. In conclusion, MMP-14 is a potential unfavorable prognostic factor for patients with NSCLC.

Mechanistic relationship between membrane type-1 matrix metalloproteinase and the myocardial response to pressure overload

BACKGROUND

Although matrix metalloproteinases (MMPs) were initially thought to result primarily in extracellular matrix degradation, certain MMP types, such as membrane type-1 (MT1) MMP, may also be involved in profibrotic cascades through hydrolysis of latency-associated transforming growth factor-binding protein (LTBP-1) and activation of transforming growth factor-dependent profibrotic signaling. The present study tested the hypothesis that MT1-MMP plays a direct role in the matrix remodeling response to a left ventricular (LV) pressure overload (PO) stimulus.

METHODS AND RESULTS

Wild-type (WT) and transgenic mice with cardiac-restricted MT1-MMP overexpression or MT1-MMP reduced expression underwent PO for 4 weeks. PO resulted in a 57% increase in LV mass (no change in LV end diastolic volume, resulting in an increase in the LV mass/volume ratio consistent with concentric remodeling), a 60% increase in MT1-MMP-mediated LTBP-1 hydrolysis and a 190% increase in collagen content in WT mice. Although LV mass was similar among WT, MT1-MMP overexpression, and MT1-MMP reduced expression after PO, significant differences in LV function, MT1-MMP-mediated LTBP-1 hydrolysis, and collagen content occurred. PO in MT1-MMP overexpression increased LTBP-1 hydrolysis (18%), collagen content (60%), and left atrial dimension (19%; indicative of LV diastolic dysfunction) when compared with WT. PO in MT1-MMP reduced expression reduced left atrial dimension (19%), LTBP-1 hydrolysis (40%), and collagen content (32%) when compared with both WT.

CONCLUSIONS

Despite an equivalent PO stimulus and magnitude of LV myocardial growth, altering MT1-MMP levels caused specific matrix-dependent changes in remodeling, thereby demonstrating a mechanistic role in the development of the maladaptive remodeling and myocardial fibrotic response to PO.

Immunohistochemical expression of MMP-14 and MMP-2, and MMP-2 activity during human ovarian follicular development

BACKGROUND

The aim of this study was to investigate the presence of MMP-14 and MMP-2 during human ovarian follicular development using immunohistochemistry, and the activity of MMP-2 in follicular fluid using zymography.

METHODS

Ovarian tissue collected from the archives of the Department of Pathology was examined and medical records and histopathology were reviewed. Follicular fluids were collected at the IVF-department and analyzed using zymography.

RESULTS

MMP-14 and MMP-2 were increasingly found in the growing follicles and MMP-2 was highly expressed in the corpus luteum. Pro-MMP-2 was present in follicular fluid of IVF-patients.

CONCLUSIONS

The presence of MMP-14 and MMP-2 during human ovarian follicular development from the primordial follicle to the tertiary follicle and corpus luteum is confirmed, as was indicated by earlier animal studies following stimulation with gonadotrophins.

Dissociation between mature phenotype and impaired transmigration in dendritic cells from heparanase-deficient mice

To reach the lymphatics, migrating dendritic cells (DCs) need to interact with the extracellular matrix (ECM). Heparanase, a mammalian endo-β-D-glucuronidase, specifically degrades heparan sulfate proteoglycans ubiquitously associated with the cell surface and ECM. The role of heparanase in the physiology of bone marrow-derived DCs was studied in mutant heparanase knock-out (Hpse-KO) mice. Immature DCs from Hpse-KO mice exhibited a more mature phenotype; however their transmigration was significantly delayed, but not completely abolished, most probably due to the observed upregulation of MMP-14 and CCR7. Despite their mature phenotype, uptake of beads was comparable and uptake of apoptotic cells was more efficient in DCs from Hpse-KO mice. Heparanase is an important enzyme for DC transmigration. Together with CCR7 and its ligands, and probably MMP-14, heparanase controls DC trafficking.

Recombinant human endostatin normalizes tumor vasculature and enhances radiation response in xenografted human nasopharyngeal carcinoma models

BACKGROUND

Hypoxic tumor cells can reduce the efficacy of radiation. Antiangiogenic therapy may transiently "normalize" the tumor vasculature to make it more efficient for oxygen delivery. The aim of this study is to investigate whether the recombinant human endostatin (endostar) can create a "vascular normalization window" to alleviate hypoxia and enhance the inhibitory effects of radiation therapy in human nasopharyngeal carcinoma (NPC) in mice.

METHODOLOGY/PRINCIPAL FINDINGS

Transient changes in morphology of tumor vasculature and hypoxic tumor cell fraction in response to endostar were detected in mice bearing CNE-2 and 5-8F human NPC xenografts. Various treatment schedules were tested to assess the influence of endostar on the effect of radiation therapy. Several important factors relevant to the angiogenesis were identified through immunohistochemical staining. During endostar treatment, tumor vascularity decreased, while the basement membrane and pericyte coverage associated with endothelial cells increased, which supported the idea of vessel normalization. Hypoxic tumor cell fraction also decreased after the treatment. The transient modulation of tumor physiology caused by endostar improved the effect of radiation treatment compared with other treatment schedules. The expressions of vascular endothelial growth factor (VEGF), matrix metalloproteinase-2 (MMP-2), MMP-9, and MMP-14 decreased, while the level of pigment epithelium-derived factor (PEDF) increased.

CONCLUSIONS

Endostar normalized tumor vasculature, which alleviated hypoxia and significantly sensitized the function of radiation in anti-tumor in human NPC. The results provide an important experimental basis for combining endostar with radiation therapy in human NPC.

Novel MT1-MMP small-molecule inhibitors based on insights into hemopexin domain function in tumor growth

Membrane type-1 matrix metalloproteinase (MT1-MMP) is a promising drug target in malignancy. The structure of MT1-MMP includes the hemopexin domain (PEX) that is distinct from and additional to the catalytic domain. Current MMP inhibitors target the conserved active site in the catalytic domain and, as a result, repress the proteolytic activity of multiple MMPs instead of MT1-MMP alone. In our search for noncatalytic inhibitors of MT1-MMP, we compared the protumorigenic activity of wild-type MT1-MMP with an MT1-MMP mutant lacking PEX (ΔPEX). In contrast to MT1-MMP, ΔPEX did not support tumor growth in vivo, and its expression resulted in small fibrotic tumors that contained increased levels of collagen. Because these findings suggested an important role for PEX in tumor growth, we carried out an inhibitor screen to identify small molecules targeting the PEX domain of MT1-MMP. Using the Developmental Therapeutics Program (National Cancer Institute/NIH), virtual ligand screening compound library as a source and the X-ray crystal structure of PEX as a target, we identified and validated a novel PEX inhibitor. Low dosage, intratumoral injections of PEX inhibitor repressed tumor growth and caused a fibrotic, ΔPEX-like tumor phenotype in vivo. Together, our findings provide a preclinical proof of principle rationale for the development of novel and selective MT1-MMP inhibitors that specifically target the PEX domain.

Expression of extracellular matrix metalloproteinase inducer (EMMPRIN) and its expected roles in the bovine endometrium during gestation

Extracellular matrix metalloproteinase inducer (EMMPRIN) and its induced matrix metalloproteinases (MMPs) play a crucial role in tissue remodeling during the peri-implantation period. However, the role of EMMPRIN in the bovine placenta is still unclear. We have postulated that EMMPRIN might play a regulatory role in trophoblastic cell functions during gestation by itself or through the regulation of MMP expression. In this study, EMMPRIN mRNA was detected in the bovine placentome and interplacentome throughout gestation, and its expression was significantly higher in the cotyledon during late gestation. In situ hybridization showed that EMMPRIN mRNA was expressed in the caruncular epithelium and the cotyledonary epithelium, including binucleate cells. Western blot analysis detected a band representing a protein of approximately 65 kDa in the caruncular and cotyledonary tissues, and the intensity of its expression was increased in both of these tissues during late gestation. The expression levels of MMP-2 and MMP-14 in the bovine placenta were higher during late gestation, as was observed for EMMPRIN. Therefore, EMMPRIN might regulate trophoblastic cell functions, especially those of binucleate cells, through MMP expression in the bovine placenta.

MicroRNA-10b induces glioma cell invasion by modulating MMP-14 and uPAR expression via HOXD10

MicroRNAs are small endogenous noncoding RNAs, which modulate target gene expression by binding with target mRNA sequences in the 3'untranslated region (UTR) with an imperfect complementarity that inhibits the mRNA translation. Many microRNAs have been reported to function as tumor oncogenes or anti-oncogenes. Recently, more and more microRNAs have been reported to contribute to a tumor's invasive potential. Here, we show that microRNA-10b (miR-10b) was over-expressed in glioma samples and directly associated with the glioma's pathological grade and malignancy. We also found that miR-10b induced glioma cell invasion by modulating tumor invasion factors MMP-14 and uPAR expression via the direct target HOXD10. The miR-10b/HOXD10/MMP-14/uPAR signaling pathway might contribute to the invasion of glioma. Accordingly, glioma cells lost their invasive ability when treated with specific antisense oligonucleotides (miR-10b inhibitors), suggesting that miR-10b could be used as a new bio-target to cure glioma.

[Expression of gelatinases A and B and their endogenous regulators in immortal and transformed fibroblasts]

Matrix metalloproteinases (MMP) play a critical role in tumor invasion and metastasis. The aim of this study was to elucidate peculiarity of expression of gelatinases A and B (MMP-2 and MMP-9), membrane type MMP (MT1-MMP) and tissue inhibitor of MMP (TIMP-2) in immortal (IF) and transformed fibroblasts (TF).The study was carried out using embryo rat fibroblasts, sequentially immortalized with the polyomavirus LT gene and transformed with the E7 gene of human papilloma virus (HPV-16). Papilloma virus type 16 and 18 are etiological factors of cervical cancer. The primary fibroblast (PF) culture of Fisher rats was used as control. Analysis of TF and IF involved: determination of MMP-2 and MMP-9 activity by hydrolysis of specific substrate--radioactive collagen type IV; obtaining of MMP spectra by zimographic assay and estimation of the mRNA expression (by RT-PCR) of MMP-2, MMP-9, MT1- MMP and TIMP-2. It was found: 1) collagenolytic activity of MMP was increased only in TF and was dependent on the degree of cell tumorogenity; 2) the study of MMP spectra was shown that MMP-9 was found in TF only but MMP-2 was found in all investigated clones; 3) The mRNA expression of MMP-9, MT1-MMP and TIMP-2 was increased in all TF while the MMP-2 expression was increased in TF only after TF cell selection on rats; 4) The collagenolytic activity as well as the mRNA expression of MMP-2 and MMP-9 themselves and of MMP-2 endogenous regulators (MT1-MMP and TIMP-2) did not change in immortalized fibroblasts compared to PF. The data obtained indicate changes in the enzyme/inhibitor/activator ratio and also suggest of a significant increase in the TF destructive potential. MMP-9 is supposed to be a marker of fibroblasts transformed by E7 HPV-16 gene in cell culture.

Expression of E1AF, an ets-oncogene transcription factor, highly correlates with malignant phenotype of malignant melanoma through up-regulation of the membrane-type-1 matrix metalloproteinase gene

Matrix metalloproteinase (MMP) is closely involved in the degradation of extracellular matrix and confers invasive and metastatic potential to malignant tumors. MMP-2 is a type-IV collagenase secreted as a proenzyme that is activated on the surface of the tumor cell by membrane-type 1-MMP (MT1-MMP). MT1-MMP plays a critical role during tumor progression and metastasis. We investigated the expression levels of E1AF and MT1-MMP in malignant melanoma cell lines and specimens from patients in order to clarify the mechanisms responsible for the invasion and metastasis of malignant melanoma. High levels of E1AF and MT1-MMP mRNA expression were observed in melanoma cells by Northern blotting and real-time PCR. The expression level was highly correlated with an invasive potential determined by an in vitro invasion assay. The down-regulation of MT1-MMP was identified when E1AF was knocked down by RNA interference. These results suggest that E1AF plays a crucial role in the invasion and metastasis of malignant melanoma through up-regulating the MT1-MMP expression.

Inflammation and melanoma growth and metastasis: the role of platelet-activating factor (PAF) and its receptor

An inflammatory tumor microenvironment fosters tumor growth, angiogenesis and metastatic progression. Platelet-activating factor (PAF) is an inflammatory biolipid produced from membrane glycerophospholipids. Through the activity of its G-protein coupled receptor, PAF triggers a variety of pathological reactions including tumor neo-angiogenesis. Several groups have demonstrated that inhibiting PAF-PAF receptor pathway at the level of a ligand or receptor results in an effective inhibition of experimental tumor growth and metastasis. In particular, our group has recently demonstrated that PAF receptor antagonists can effectively inhibit the metastatic potential of human melanoma cells in nude mice. Furthermore, we showed that PAF stimulated the phosphorylation of CREB and ATF-1 in metastatic melanoma cells, which resulted in overexpression of MMP-2 and MT1-MMP. Our data indicate that PAF acts as a promoter of melanoma metastasis in vivo. Since only metastatic melanoma cells overexpress CREB/ATF-1, we propose that these cells are better equipped to respond to PAF within the tumor microenvironment when compared to their non-metastatic counterparts.

Activation ratio of MMP-2 and expression of MT1-MMP are correlated in thymic epithelial tumours

AIMS

To study the relationships between the activation of pro-MMP-2 and the mRNA levels of MT1-MMP and TIMP-2 in thymic tissues and thymic epithelial tumours.

METHODS

We examined the mRNA expressions of MMP-2, MT1-MMP and TIMP-2 with real-time reverse transcription-polymerase chain reaction (RT-PCR). The gelatinolytic activity and MMP-2 activation ratio of thymic tissues, thymomas, and thymic carcinomas were determined with gelatin zymography. The cellular localisation of MMP-2 was detected with film in situ gelatin zymography. We then examined the mRNA expression of MMP-2 in the epithelial tumour cells or lymphocytes and stromal cells distant from the tumour (obtained from two invasive thymomas) using laser-capture microdissection (LCM).

RESULTS

The mRNA levels of MMP-2, MT1-MMP and TIMP-2 were significantly increased from thymic tissue, Stage I-II, III-IV thymomas to thymic carcinomas (p<0.005). They were also significantly increased from AB-B1 (lymphocyte rich and mixed types), B2-B3 (cortical and predominantly polygonal cells types) thymomas to thymic carcinomas (p<0.05). The MMP-2 activation ratio also had the same tendency among the above groups (p<0.05) and was directly correlated to MT1-MMP and TIMP-2 mRNA expression (Spearman rank correlation: r = 0.8627, r = 0.8314; p<0.005). Film in situ zymography demonstrated that positive expression is mainly localised in tumour cell nests and adjacent stroma cells. LCM and real-time RT-PCR results confirmed that the expression of MMP-2 was higher in epithelial tumour cells than in lymphocytes and stromal cells.

CONCLUSIONS

MMP-2, MT1-MMP and TIMP-2 mRNA expression levels were correlated with clinical stages and histological subtypes of thymic epithelial tumours. The activation of pro-MMP-2 might be mediated by MT1-MMP and TIMP-2 up-regulation.

[Correlation of membrane type I matrix metalloproteinase (MT1-MMP) expression with clinicomorphological features of tumor front in squamous cell carcinoma of the larynx]

Matrix metalloproteases (MMPs) are proteolytic enzymes contribute to tumor expansion by degrading components of the extracellular matrix. MPPs play a key role in tumor invasion and metastases of various cancers and head and neck carcinoma as well. The aim of this study was to investigate MT1-MMP expression in squamous cell carcinoma of the larynx to relate these levels of expression to clinicohistological features of the tumor and lymph nodes e.g. TNM, nodal micrometastases, tumor front grading and 3- and 5-year survival.

MATERIAL AND METHODS

The study included 22 patients with laryngeal cancer surgical treated in ENT Department Medical University of Lódź between 1998 and 1999. The expression of MT1-MMP was evaluated immunohistochemically using monoclonal antibodies anti-MT1-MMP (Mouse Anti-Human MT1-MMP, MAB3319 Chemicon). The polyclonal antibodies anti-CK for developing nodal micrometastases was used as well.

RESULTS

Positive MT1-MMP expression in 68.2% cases was observed. Immunoexpression of MT1-MMP in advanced laryngeal carcinoma as indicator for 3-year survival was noted. In addition, levels of staining correlated with number of mitoses in tumor front and plasmocytolymphatic infiltration in its environment.

CONCLUSIONS

The expression of MT1-MMP in tumor front appears to play an important role in determining prognosis in patients with carcinoma of the larynx.

Significant relationship of matrix metalloproteinase 9 with nuclear grade and prognostic impact of tissue inhibitor of metalloproteinase 2 for incidental clear cell renal cell carcinoma

OBJECTIVE

To examine the immunoreactivity of tumors for matrix metalloproteinases 2 and 9 (MMP-2, MMP-9), tissue inhibitors of metalloproteinases 1 and 2 (TIMP-1, TIMP-2), and membrane type MMP 1 (MT-MMP-1), to evaluate the optimum assessment of incidental renal cell carcinoma.

METHODS

Tumor samples from 120 incidental clear cell renal cell carcinoma (ICRCC) patients without distant metastasis or invasion beyond Gerota's fascia were obtained by surgery. They were immunohistochemically stained for MMP-2, MMP-9, TIMP-1, TIMP-2, and MT-MMP-1. Immunoreactivity for these factors was analyzed by semiquantitative multivariate analysis for cancer-specific survival.

RESULTS

The cancer-specific 5 and 10-year survival rates were 91.4% and 91.4%, respectively. Univariate analysis revealed that nuclear grade (P = 0.0064) and TIMP-2 (P = 0.034) were significant prognostic factors. Matrix metalloproteinase 9 has a significant relationship with high nuclear grade RCC (P = 0.017) and was found to be an independent prognosticator by Cox multiple regression analysis (P = 0.0028).

CONCLUSIONS

Nuclear grade and TIMP-2 were significant prognostic factors of ICRCC. Multivariate analysis showed that a nuclear grade greater than 3 was associated with a 566% significant increase in the odds of cancer death. Strong expression of MMP-9 was associated with a 774% increase in the odds of high nuclear grade, with statistical significance. Although ICRCC is well known for having a favorable prognosis, patients with tumors having a high nuclear grade and strongly expressed MMP-9 and TIMP-2 should undergo strict postoperative follow-up.

Construction of antisense MT1-MMP vector and its inhibitory effects on invasion of human ovarian cancer cells

Membrane-type 1 matrix metalloproteinase (MT1-MMP/MMP-14) plays crucial roles in tumor cell growth, invasion, and angiogenesis. To clarify whether the endogenously expressed MT1-MMP in metastatic human ovarian carcinoma cell lines SKOV3 plays a critical role in tumor cell invasiveness, antisense MT1-MMP cloned in eukaryotic expression vector pMMP14as was transferred into SKOV3 cells. 48h after transfection, decreased expression of endogenous MT1-MMP protein was detected in pMMP14as-transfected SKOV3 cells and the activation of pro-MMP2 was inhibited markedly. The mean percentage of invasive cells was (62.50 +/- 5.30) % in pMMP14as-transfected cells, which was obviously less than that (97.20 +/- 6.90) % in the control. Thus, antisense MT1-MMP effectively inhibited the endogenous MT1-MMP expression and the invasiveness in SKOV3 cells, suggesting that MT1-MMP may be a therapeutic target molecule for human invasive ovarian cancers.

A multivariate analysis of adhesion molecules expression in assessment of colorectal cancer

BACKGROUND AND OBJECTIVES

Adhesion molecules are implicated in the progression of colorectal cancer (CRC). Despite the evidence of association between their expression and patients' prognosis, the data have not been examined simultaneously in a same study; thus, the relative clinical value remained largely unknown. The aim of this study was to identify the adhesion factors that display the most significant prognostic value for CRC patients to guide clinical decision-making regarding appropriate treatment.

PATIENTS AND METHODS

We examined by immunohistochemistry, the expression of E-cadherin and its associated catenins, alpha(alpha)-catenin and beta(beta)-catenin, DCC, and CD44 and its partner, MT1-MMP in a series of 140 CRC tissues at intermediate Stage II and Stage III to determine their prognostic significance.

RESULTS

Clinicopathological survey indicated an inverse relationship between E-cadherin expression and tumor differentiation, and an association between CD44 expression and venous invasion. Univariate and multivariate analyses showed that loss of expression of E-cadherin and CD44 significantly correlated to poor survival, especially in Stage II. Combination studies indicated that loss of E-cadherin and loss of CD44 had the worst impact on patient prognosis, particularly in colon cancer.

CONCLUSION

Immunohistochemical staining of E-cadherin and CD44 may help to identify a subgroup of high-risk patients with Stage II CRC, especially in colon cancer, who may need intensive follow-up and appropriate therapeutic strategy.

Stroma-derived matrix metalloproteinase (MMP)-2 promotes membrane type 1-MMP-dependent tumor growth in mice

Matrix metalloproteinase-2 (MMP-2) is a stroma-derived MMP belonging to the type IV collagenase family. It is believed to mediate tumor cell behavior by degrading deposits of type IV collagen, a major component of the basement membrane. The membrane type 1-MMP (MT1-MMP) is a highly potent activator of MMP-2 and is expressed in many tumor and stromal cells. However, the roles played by stromal MMP-2 in tumor progression in vivo remain poorly understood. We established a colon epithelial cell line from an Mt1-mmp(-/-) mouse strain and transfected these cells with an inducible expression system for MT1-MMP (MT1rev cells). Following s.c. implantation into Mmp-2(+/+) mice and induction of MT1-MMP expression, MT1rev cells grew rapidly, whereas they grew very slowly in Mmp-2(-/-) mice, even in the presence of MT1-MMP. This MT1-MMP-dependent tumor growth of MT1rev cells was enhanced in Mmp-2(-/-) mice as long as MMP-2 was supplied via transfection or coimplantation of MMP-2-positive fibroblasts. MT1rev cells cultured in vitro in a three-dimensional collagen gel matrix also required the MT1-MMP/MMP-2 axis for rapid proliferation. MT1rev cells deposit type IV collagen primarily at the cell-collagen interface, and these deposits seem scarce at sites of invasion and proliferation. These data suggest that cooperation between stroma-derived MMP-2 and tumor-derived MT1-MMP may play a role in tumor invasion and proliferation via remodeling of the tumor-associated basement membrane. To our knowledge, this is the first study demonstrating that MT1-MMP-dependent tumor growth in vivo requires stromal-derived MMP-2. It also suggests that MMP-2 represents a potential target for tumor therapeutics.

1-furan-2-yl-3-pyridin-2-yl-propenone inhibits the invasion and migration of HT1080 human fibrosarcoma cells through the inhibition of proMMP-2 activation and down regulation of MMP-9 and MT1-MMP

Matrix metalloproteinases (MMPs) play important roles in solid tumor invasion and migration. In this study, we showed that 1-furan-2-yl-3-pyridin-2-yl-propenone (FPP-3) dose-dependently inhibited HT1080 cell invasion and migration, and decreased MMP-2 and MMP-9 activities. Furthermore, FPP-3 reduced MMP-2 expression at protein and mRNA levels, and suppressed 12-O-tetradecanoylphorbol-13-acetate (TPA)-enhanced expression of MT1-MMP without changing tissue inhibitors of metalloproteinase (TIMP)-2 level. FPP-3 also suppressed TPA-induced increases in MMP-9 protein and mRNA levels, but did not alter TIMP-1 level. Our results suggest that FFP-3 may be a valuable anti-invasive drug candidate for cancer therapy by suppressing MMP-2, MMP-9, and MT1-MMP.

Substrate choice of membrane-type 1 matrix metalloproteinase is dictated by tissue inhibitor of metalloproteinase-2 levels

Although tissue inhibitor of metalloproteinase-2 (TIMP-2) is known to be not only an inhibitor of matrix metalloproteinases (MMP) but also a cofactor for membrane-type 1 MMP (MT1-MMP)-mediated MMP-2 activation, it is still unclear how TIMP-2 regulates MMP-2 activation and cleavage of substrates by MT1-MMP. In the present study we examined the levels of cell-surface MT1-MMP, MMP-2 activation and cleavage of MT1-MMP substrates in 293T cells transfected with the MT1-MMP and TIMP-2 genes. Co-expression of TIMP-2 at an appropriate level increased the level of cell-surface MT1-MMP, both the TIMP-2-bound and free forms, and generated processed MMP-2 with gelatin-degrading activity. In contrast, MT1-MMP substrates testican-1 and syndecan-1 were cleaved by the cells expressing MT1-MMP, which was inhibited by TIMP-2 even at levels that stimulate MMP-2 activation. These results suggest that TIMP-2 environment determines MT1-MMP substrate choice between direct cleavage of its own substrates and MMP-2 activation.

mda-9/Syntenin regulates the metastatic phenotype in human melanoma cells by activating nuclear factor-kappaB

mda-9/Syntenin is a scaffolding PDZ domain-containing protein overexpressed in multiple human cancers that functions as a positive regulator of melanoma metastasis. Using a normal immortal human melanocyte cell line and weakly and highly metastatic human melanoma cell lines, we presently show that mda-9/syntenin initiates a signaling cascade that activates nuclear factor-kappaB (NF-kappaB) in human melanoma cells. As a consequence of elevated mda-9/syntenin expression, tumor cell growth and motility, fundamental components of tumor cell invasion and metastatic spread of melanoma cells, are enhanced through focal adhesion kinase (FAK)-induced and p38 mitogen-activated protein kinase (MAPK)-induced activation of NF-kappaB. Inhibiting mda-9/syntenin, using an adenovirus expressing antisense mda-9/syntenin, NF-kappaB, using an adenovirus expressing a mutant super-repressor of IkappaBalpha, or FAK, and using a dominant-negative mutant of FAK (FRNK), blocks melanoma cell migration, anchorage-independent growth, and invasion. Downstream signaling changes mediated by mda-9/syntenin, which include activation of FAK, p38 MAPK, and NF-kappaB, promote induction of membrane-type matrix metalloproteinase-1 that then activates pro-MMP-2-promoting migration and extracellular matrix invasion of melanoma cells. These results highlight the importance of mda-9/syntenin as a key component of melanoma metastasis providing a rational molecular target for potentially intervening in the metastatic process.

A matrix metalloproteinase-9 activation cascade by hepatic stellate cells in trans-differentiation in the three-dimensional extracellular matrix

Hepatic stellate cells (HSCs) undergo myofibroblastic trans-differentiation in liver fibrogenesis. We previously showed that dual stimulation with three-dimensional type-I collagen and interleukin-1 (IL-1) synergistically induces HSC trans-differentiation in a manner dependent on the activation of matrix metallopreinase-9 (MMP-9). The present study is aimed to determine the mechanism of MMP-9 activation in this model. The pro-MMP-9-converting activities expressed by trans-differentiating HSCs are characterized as secreted factors that are sensitive to MMP inhibitor and have apparent molecular masses of 50 and 25 kDa. This is in sharp contrast to the pro-MMP-9 activator from mouse and human skin, which is a chymotrypsin-like proteinase. Among multiple MMPs induced in HSCs by the dual stimulation, MMP-13 is most conspicuously up-regulated and meets all criteria as the pro-MMP-9 activator. HSC cultured in three-dimensional type-I collagen, but not in Matrigel, IL-1 induces expression of MMP-13 and its matured form at 50 and 25 kDa, respectively. In vitro reconstitution experiment proves that MMP-13, but not its zymogen, activates pro-MMP-9. Further, short hairpin RNA targeting MMP-13 abolishes pro-MMP-9 activation and HSC trans-differentiation. We further demonstrate that pro-MMP-13 activation is facilitated with a membrane-associated factor, inhibited with tissue inhibitor of metalloproteinase-2, and abolished with short hairpin RNA against MMP-14. Moreover, pro-MMP-13 is also activated by a secreted factor, which is absorbed by gelatin-Sepharose and reconstituted with MMP-9. Thus, IL-1-induced trans-differentiation of HSCs in three-dimensional extracellular matrix is facilitated by an MMP activation cascade (MMP-14 > MMP-13 > MMP-9) and a positive feedback loop of MMP-9 > MMP-13, suggesting their critical roles in liver injury and repair.

Clinicopathologic and prognostic significance of matrix metalloproteinases in rectal cancer

BACKGROUND AND AIMS

The aim of this study was to determine the prognostic role of matrix metalloproteinases in rectal cancer.

MATERIALS AND METHODS

Formalin-fixed and paraffin-embedded tissue sections of 94 rectal carcinomas were used for the immunohistochemical analysis of matrix metalloproteinases (MMP)-2, MMP-7, MT1-MMP, and tissue inhibitor of metalloproteinases (TIMP)-2. Inclusion criteria were sporadic rectal adenocarcinoma resected curatively (including total mesorectal excision), adjuvant radiochemotherapy in UICC stages II and III, and complete intra-institutional follow-up. Results of immunohistochemistry were correlated with clinical and histopathologic data from the prospective rectal cancer registry and prognosis. End points of the prognostic analysis were tumor progression caused by local and/or distant recurrence and 5-year survival (disease-free and overall). To assess prognostic significance, statistics included univariate and multivariate analysis (p<0.05 statistically significant).

RESULTS

Of the 94 rectal carcinomas, 35% (33/94) showed an epithelial MMP-2 expression, 77% (72/94) were MMP-2 positive in the stroma. Fifty-four percent (51/94) were MMP-7 positive, and 47% (46/94) were positive for both MT1-MMP and TIMP-2. The stromal MMP-2 staining pattern was correlated with the depth of invasion (pT status, p=0.006) with MMP-7 (p=0.016) and TIMP-2 expression (p=0.036). Positive expression of MMP-2 in tumor epithelium was correlated with MMP-7 (p=0.027), MT1-MMP (p=0.036), and TIMP-2 expression (p<0.0001). A positive staining pattern of MMP-7 was significantly correlated with depth of invasion and TIMP-2 (p<0.01). The positive staining pattern of MT1-MMP was correlated with epithelial MMP-2 (p=0.036), MMP-7 (p=0.004), and TIMP-2 expression (p=0.002). TIMP-2 immunoreactivity correlated with depth of invasion (p=0.013), epithelial MMP-2 (p<0.001), stromal MMP-2 (p=0.036), MMP-7 (p<0.001), and MT1-MMP (p=0.002). Neither pattern correlated with age, gender, tumor stage (UICC), grading, preoperative serum carcinoembryonic antigen (CEA) level, or nodal status (p>0.05). Within a mean follow-up of 46 months, tumor progression, caused by either local recurrence or distant metastasis, occurred in 14 patients (15.4%). There was no significant association between the MMP expression and the incidence of local and/or distant recurrence. In terms of survival, preoperative CEA level (disease-free 5-year survival 46% with increased CEA vs 70% with normal CEA, p=0.01; overall 5-year survival 43 vs 74%, p<0.01) and UICC stage were the only factors to be significantly related to 5-year survival by univariate analysis, whereas the metalloproteinases failed to show a significant association. In multivariate analysis, CEA and UICC stage were not identified as independent factors predictive of survival.

CONCLUSION

MMP-2, MMP-7, MT1-MMP, and TIMP-2 do not appear to be significant predictors of prognosis in a homogenous collective of curatively resected rectal adenocarcinomas.

Microenvironmental Regulation of Membrane Type 1 Matrix Metalloproteinase Activity in Ovarian Carcinoma Cells via Collagen-induced EGR1 Expression

Late stage ovarian cancer is characterized by disseminated intraperitoneal metastasis as secondary lesions anchor in the type I and III collagen-rich submesothelial matrix. Ovarian carcinoma cells preferentially adhere to interstitial collagen, and collagen-induced integrin clustering up-regulates the expression of the transmembrane collagenase membrane type 1 matrix metalloproteinase (MT1-MMP). Collagenolytic activity is important in intraperitoneal metastasis, potentiating invasion through the mesothelial cell layer and colonization of the submesothelial collagen-rich matrix. The objective of this study was to elucidate a potential mechanistic link between collagen adhesion and MT1-MMP expression. Our results indicate that culturing cells on three-dimensional collagen gels, but not thin layer collagen or synthetic three-dimensional hydrogels, results in rapid induction of the transcription factor EGR1. Integrin signaling through a SRC kinase-dependent pathway is necessary for EGR1 induction. Silencing of EGR1 expression using small interfering RNA abrogated collagen-induced MT1-MMP expression and inhibited cellular invasion of three-dimensional collagen gels. These data support a model for intraperitoneal metastasis wherein collagen adhesion and clustering of collagen binding integrins activates integrin-mediated signaling via SRC kinases to induce expression of EGR1, resulting in transcriptional activation of the MT1-MMP promoter and subsequent MT1-MMP-catalyzed collagen invasion. This model highlights the role of unique interactions between ovarian carcinoma cells and interstitial collagens in the ovarian tumor microenvironment in inducing gene expression changes that potentiate intraperitoneal metastatic progression.

In Vitro Efficacy of a Sterically Stabilized Immunoliposomes Targeted to Membrane Type 1 Matrix Metalloproteinase (MT1-MMP)

The poor selective cytotoxicity of anticancer drugs lead to dose-limiting adverse effects which compromise the clinical outcome. Solid tumors recruit new blood vessels to support their growth, and epitopes that are uniquely expressed on tumor cells and tumor endothelial cells (ECs) can function as targets for immunoliposomal anticancer drugs. Membrane type 1 matrix metalloproteinase (MT1-MMP), an important protein related to tumor growth and angiogenesis, is expressed on malignant tumor cells and is activated ECs. Selective delivery could be achieved by targeting MT1-MMP, as well as other angiogenic ECs. In this regard, an anti-MT1-MMP Fab' antibody was used to prepare a MT1-MMP targeted sterically stabilized immunoliposomes (SIL[anti-MT1-MMP(Fab')]). The binding and intracellular distribution of SIL[anti-MT1-MMP(Fab')] and a non-targeted sterically stabilized liposomes (SL) were examined using human fibrosarcoma HT-1080 cells. SIL[anti-MT1-MMP(Fab')] was taken up by the cells in a lipid concentration, temperature, and time dependent manner, ultimately accumulating in the lysosomes. The cytotoxicity of doxorubicin (DXR)-containing SIL[anti-MT1-MMP(Fab')] (DXR-SIL[anti-MT1-MMP(Fab')]) was significantly higher than that of DXR-containing SL. The cellular internalization of SIL[anti-MT1-MMP(Fab')] was inhibited by endocytosis inhibitors, suggesting that their internalization was mediated via clathrin- or caveolae-dependent endocytosis. Furthermore, the efficient binding of SIL[anti-MT1-MMP(Fab')] was observed on human umbilical vein endothelial cells (HUVEC). Based on these results, it would be expected that DXR-SIL[anti-MT1-MMP(Fab')] may achieve direct tumor cell kill and indirect tumor cell kill via the destruction of the tumor endothelium in vivo. This strategy may have the potential for overcoming some major limitations in conventional chemotherapy in vivo.

MMP-2, MT1-MMP, and TIMP-2 are essential for the invasive capacity of human mesenchymal stem cells: differential regulation by inflammatory cytokines

Human mesenchymal stem cells (hMSCs) represent promising tools in various clinical applications, including the regeneration of injured tissues by endogenous or transplanted hMSCs. The molecular mechanisms, however, that control hMSC mobilization and homing which require invasion through extracellular matrix (ECM) barriers are almost unknown. We have analyzed bone marrow-derivedhMSCs and detected strong expression and synthesis of matrix metalloproteinase 2 (MMP-2), membrane type 1 MMP (MT1-MMP), tissue inhibitor of metalloproteinase 1 (TIMP-1), and TIMP-2. The ability of hMSCs to traverse reconstituted human basement membranes was effectively blocked in the presence of synthetic MMP inhibitors. Detailed studies by RNA interference revealed that gene knock-down of MMP-2, MT1-MMP, or TIMP-2 substantially impaired hMSC invasion, whereas silencing of TIMP-1 enhanced cell migration, indicating opposing roles of both TIMPs in this process. Moreover, the inflammatory cytokines TGF-beta1, IL-1beta, and TNF-alpha up-regulated MMP-2, MT1-MMP, and/or MMP-9 production in these cells, resulting in a strong stimulation of chemotactic migration through ECM, whereas the chemokine SDF-1alpha exhibited minor effects on MMP/TIMP expression and cell invasion. Thus, induction of specific MMP activity in hMSCs by inflammatory cytokines promotes directed cell migration across reconstituted basement membranes in vitro providing a potential mechanism in hMSC recruitment and extravasation into injured tissues in vivo.

Green tea polyphenol epigallocatechin-3-gallate suppresses rat hepatic stellate cell invasion by inhibition of MMP-2 expression and its activation

AIM

Epigallocatechin-3-gallate (EGCG) is the major component of green tea polyphenols, whose wide range of biological properties includes anti-fibrogenic activity. Matrix metalloproteinases (MMP) that participate in extracellular matrix degradation are involved in the development of hepatic fibrosis. The present study investigates whether EGCG inhibits activation of the major gelatinase matrix metalloproteinase-2 (MMP-2) in rat hepatic stellate cells (HSC).

METHODS

The expression of MMP-2, tissue inhibitors of metalloproteinases-2 (TIMP-2), and membrane-type 1-MMP (MT1-MMP) was assessed by RT-PCR and Western blot analyses. MMP-2 activity was evaluated by zymography and MT1-MMP activity was assessed by an enzymatic assay. HSC migration was measured by a wound healing assay and cell invasion was performed using Transwell cell culture chambers.

RESULTS

The expression of MMP-2 mRNA and protein in HSC was substantially reduced by EGCG treatment. EGCG treatment also reduced concanavalin A (ConA)-induced activation of secreted MMP-2 and reduced MT1-MMP activity in a dose-dependent manner. In addition, EGCG inhibited either HSC migration or invasion.

CONCLUSION

The abilities of EGCG to suppress MMP-2 activation and HSC invasiveness suggest that EGCG may be useful in the treatment and prevention of hepatic fibrosis.

The clinical relevance of stromal matrix metalloproteinase expression in ovarian cancer

PURPOSE

Matrix metalloproteinases (MMP) are proteolytic enzymes implicated in cancer progression and metastasis. We sought to determine the role of epithelial (tumor cell-derived) and stromal (host-derived) expression of MMPs in predicting the clinical outcome of patients with epithelial ovarian cancer (EOC).

EXPERIMENTAL DESIGN

MMP-2, MMP-9, and membrane type 1 (MT1)-MMP expression was evaluated using immunohistochemistry in 90 invasive EOCs, and samples were scored for epithelial and stromal staining. Results were correlated with clinicopathologic characteristics using univariate and multivariate analyses.

RESULTS

High expression of MMP-2, MMP-9, and MT1-MMP in tumor epithelium was detected in 54%, 97%, and 100% of cases, and in stromal compartments, in 38%, 70%, and 38% of cases, respectively. High stromal expression of MMP-2, MMP-9, and MT1-MMP was significantly associated with aggressive features such as high stage, high grade ascites, and positive lymph node status. Kaplan-Meier analysis showed that high epithelial and stromal expression of MMP-2, MMP-9, and MT1-MMP were each significantly associated with shorter disease-specific survival (DSS; P < 0.01). On tree-structured survival analysis, patients with strong epithelial MT1-MMP expression had the shortest DSS, whereas patients with moderate epithelial MT1-MMP and low stromal MMP-9 expression had the longest DSS (P < 0.01). On multivariate analysis, high stromal expression of MMP-9 (P = 0.01) and MT1-MMP (P = 0.04), strong epithelial MT1-MMP (P = 0.01) and high stage (P = 0.04) were independent predictors of poor DSS.

CONCLUSIONS

Overexpression of stromal MMP-9 and MT1-MMP is independently associated with shorter DSS in EOC. Thus, host-derived MMPs are valuable predictors of clinical outcome in EOC.

Effects of cyclic mechanical stretch on extracellular matrix synthesis by human scleral fibroblasts

In order to understand the effect of mechanical strain on scleral extracellular matrix remodeling, human scleral fibroblasts were subjected to equibiaxial stretch in vitro and the expression of proteoglycans, metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase-2 (TIMP-2) were evaluated. Isolated human scleral fibroblasts were seeded onto flexible bottom culture plates, and subjected to a cyclic stretch regimen of 15% equibiaxial stretch for 45 s followed by 15s of rest for 6-48 h in the presence of 35SO4. Newly synthesized proteoglycans were measured in the medium by CPC precipitation of radiolabelled glycosaminoglycans. MMP-2 activity and expression levels were measured in the medium by, Western blot, gel zymography and real-time PCR. Steady state levels of TIMP-2 mRNA and membrane-type MMP, MT1-MMP (MMP-14) mRNA were measured in the cell layer using real-time PCR. The predominant gelatinolytic enzyme secreted by scleral fibroblasts was the pro-enzyme form of MMP-2 (ProMMP-2). Mechanical stretch resulted in a significant increase of ProMMP-2 after 12 and 48 h (+76.28%, p<0.05; +19.56%, p<0.01, respectively). Mechanical stretch significantly increased the production of the active form of MMP-2 (ActiveMMP-2) after 48 h (+59.72%, p<0.05) and decreased levels of TIMP-2 mRNA (-22%, p<0.05). The rate of scleral proteoglycan synthesis and the steady state levels of MMP-2 and MMP-14 mRNA were not significantly affected by mechanical stretch. These results suggest that mechanical strain stimulates the activation of MMP-2 by scleral fibroblasts, possibly through increased levels of ProMMP-2 and reduced levels of TIMP-2. Increased levels of ActiveMMP-2 in the sclera would be expected to contribute to scleral extracellular matrix degradation, scleral thinning and possible ocular ectasia.

Neutrophil activator of matrix metalloproteinase-2 (NAM)

We have isolated a novel soluble factor(s), neutrophil activator of matrix metalloproteinases (NAM), secreted by unstimulated normal human peripheral blood neutrophils that causes the activation of cell secreted promatrix metalloproteinase-2 (proMMP-2). Partially purified preparations of NAM have been isolated from the conditioned media of neutrophils employing gelatin-Sepharose chromatography and differential membrane filter centrifugation. NAM activity, as assessed by exposing primary human umbilical vein endothelial cells (HUVEC) or HT1080 cells to NAM followed by gelatin zymography, was seen within one hour. Tissue inhibitor of metalloproteinase-2 (TIMP-2) and hydroxamic acid derived inhibitors of MMPs (CT1746 and BB94) abrogated the activation of proMMP-2 by NAM, while inhibitors of serine and cysteine proteases showed no effect. NAM also produced an increase in TIMP-2 binding to HUVEC and HT1080 cell surfaces that was inhibited by TIMP-2, CT1746, and BB94. Time-dependent increases in MT1-MMP protein and mRNA were seen following the addition of NAM to cells. These data support a role for NAM in cancer dissemination.

Activity of matrix metalloproteinase-2 (MMP-2) in canine oronasal tumors

Activity of matrix metalloprotease-2 (MMP-2) and the expression of its related molecules were examined in spontaneous canine oronasal tumors. Tissue samples from melanoma and squamous cell carcinoma possessed higher MMP-2 activity, as shown in gelatin zymography, in comparison with acanthomatous epulis and nasal adenocarcinoma. Regional lymph node invasion and distant metastases were more frequently observed in the MMP-2 positive cases. There were no significant differences by RT-PCR examination in the expression of the genes encoding MMP-2, MT1-MMP and TIMP-2 among the tumor histological types. However, the MMP-2/TIMP-2 ratio showed a significantly higher level of the genes in the malignant oral melanoma and squamous cell carcinoma. The MMP-2/TIMP-2 ratio was also positively correlated with MMP-2 activity in gelatin zymography. These results indicate that the MMP-2/TIMP-2 ratio may be of value in evaluating the prognosis in canine oronasal cavity tumors.

Predictive value of laminin-5 and membrane type 1-matrix metalloproteinase expression for cervical lymph node metastasis in T1 and T2 squamous cell carcinomas of the tongue and floor of the mouth

BACKGROUND

Laminin-5 (Ln-5) cleaved by membrane type 1-matrix metalloproteinase (MT1-MMP) enhances the migration of tumor cells. The purpose of this study was to determine whether or not enhanced expression of both Ln-5 and MT1-MMP was associated with lymph node metastasis in patients with T1 and T2 squamous cell carcinoma (SCC) of the tongue and floor of the mouth.

METHODS

By use of biopsy specimens of primary tumors from 57 patients, intratumoral expression of Ln-5 and MT1-MMP was evaluated immunohistochemically and its association with node metastasis analyzed.

RESULTS

The tumors were categorized into three groups: Ln-5 focal type/MT1-MMP (-) (group I, n = 14), Ln-5 focal type/ MT1-MMP (+) and Ln-5 diffuse type/MT1-MMP (-) (group II, n = 16), and Ln-5 diffuse type/MT1-MMP (+) (group III, n = 27). The incidence of node metastasis (initial and latent metastases) was two of 14 (14.3%), five of 16 (31.3%), and 15 of 27 (55.6%) in groups I, II, and III, respectively. Multivariate analysis identified tumor thickness (odds ratio, 4.751; p = .0152) and Ln-5/ MT1-MMP expression (odds ratio, 3.795, p = .0304) as independent factors of node metastasis. Moreover, in 35 patients with N0 disease, Ln-5/MT1-MMP expression was the only parameter associated with latent node metastasis (odds ratio, 12.800, p = .0247).

CONCLUSION

These results suggest that immunohistochemical evaluation of Ln-5 and MT1-MMP expression is useful for identifying patients with T1 and T2 SCC of the tongue and floor of the mouth who should be treated with elective neck dissection.