Matrilysin-specific antisense oligonucleotide inhibits liver metastasis of human colon cancer cells in a nude mouse model

The Glabridin from Huangqin Decoction Prevents the Development of Ulcerative Colitis into Colitis-Associated Colorectal Cancer by Modulating MMP1/MMP3 Activity

BACKGROUND AND AIM

Huangqin decoction (HQD) is a Chinese medicine used to treat colitis and colorectal cancer (CRC). However, the specific compounds and mechanisms of HQD remain unclear despite its good curative clinical results. Through bioinformatics, network pharmacology, and experiments, this study aims to explore the progressive mechanisms of colitis-associated colorectal cancer (CAC) from ulcerative colitis (UC) while examining the protective effects of HQD and its compounds against this.

METHODS

Bioinformatics was utilized to identify the hub genes between UC and CRC, and their clinical predictive significance, function, and expression were validated. Employing network pharmacology in combination with hub genes, key targets of HQD for preventing the development of UC into CAC were identified. Molecular docking and molecular dynamics (MD) were utilized to procure compounds that effectively bind to these targets and their transcription factors (TFs). Finally, the expression and mechanism of key targets were demonstrated in mice with UC or CAC.

RESULTS

(1) Joint analysis of UC and CRC gene sets resulted in 14 hub genes, mainly related to extracellular matrix receptor binding, biological processes in the extracellular matrix, focal adhesion and neutrophil migration; (2) Network pharmacology results show HQD has 133 core targets for treating UC and CRC, acting on extracellular matrix, inflammatory bowel disease, chemical carcinogen receptor activation and other pathways; (3) The intersection of hub genes and core targets yielded two key targets, MMP1 and MMP3; (4) STAT3 is a shared TF of MMP1 and MMP3. (5) Molecular docking and MD verified that the dockings between Glabridin and STAT3/MMP1/MMP3 are stable and reliable; (6) In murine vivo experiments verified that Glabridin reduces inflammation, extracellular matrix degradation, and the occurrence of epithelial-mesenchymal transition to prevent UC transforming into CAC by inhibiting the phosphorylation of STAT3 and regulating the activity of MMP1/3.

Unraveling anticancer potential of a novel serine protease inhibitor from marine yeast Candida parapsilosis ABS1 against colorectal and breast cancer cells

The study was planned to isolate a serine protease inhibitor compound with anticancer potential against colorectal and breast cancer cells from marine yeast. Protease enzymes play a crucial role in the mechanism of life-threatening diseases like cancer, malaria and AIDS. Hence, blocking these enzymes with potential inhibitors can be an efficient approach in drug therapy for these diseases. A total of 12 marine yeast isolates, recovered from mangrove swamps of Sundarbans, India, showed inhibition activity against trypsin. The yeast isolate ABS1 showed highest inhibition activity (89%). The optimum conditions for protease inhibitor production were found to be glucose, ammonium phosphate, pH 7.0, 30 °C and 2 M NaCl. The PI protein from yeast isolate ABS1 was purified using ethyl acetate extraction and anion exchange chromatography. The purified protein was characterized using denaturing SDS-PAGE, Liquid Chromatography Electrospray Ionization Mass Spectrometry (LC-ESI-MS), Reverse Phase High Pressure Liquid Chromatography (RP-HPLC) and Fourier Transform Infra-red Spectroscopy (FTIR) analysis. The intact molecular weight of the PI protein was determined to be 25.584 kDa. The PI protein was further studied for in vitro anticancer activities. The IC₅₀ value for MTT cell proliferation assay was found to be 43 µg/ml against colorectal cancer HCT15 cells and 48 µg/ml against breast cancer MCF7 cells. Hoechst staining, DAPI staining and DNA fragmentation assay were performed to check the apoptotic cells. The marine yeast was identified as Candida parapsilosis ABS1 (Accession No. MH782231) using 18s rRNA sequencing.

Farnesoid X receptor represses matrix metalloproteinase 7 expression, revealing this regulatory axis as a promising therapeutic target in colon cancer

The farnesoid X receptor (FXR) is a member of the nuclear receptor superfamily of bile acid-activated transcription factors and an important regulator of cell proliferation, apoptosis, and Wnt signaling. Down-regulated expression of FXR plays an important role in some malignancies such as colon cancer, and in rodent models of intestinal neoplasia, FXR knockout increases the size and number of colon tumors. These previous observations implicate FXR as a tumor suppressor, but the underlying molecular mechanisms are unclear. Employing complementary experimental approaches and using human colon cancer specimens, human and murine colon cancer cell lines, and FXR transgenic mice, here we identified an additional, potentially important role for FXR. We observed an inverse relationship between the expression of FXR and matrix metalloproteinase-7 (MMP7), a collagenase and signaling molecule consistently associated with colon cancer progression. We noted that FXR gene ablation increases MMP7 expression. Consistent with this finding, FXR overexpression and a dominant-negative FXR mutation reduced and augmented, respectively, MMP7 expression. Of note, MMP7 was the only MMP gene family member whose expression was down-regulated after FXR activation. FXR-mediated regulation of MMP7 transcription did not require heterodimerization with the retinoid X receptor (RXR), indicating that FXR represses MMP7 expression independently of RXR. Last, we uncovered that FXR suppresses MMP7 transcription by binding to a negative FXR-responsive element in the 5' MMP7 promoter, an event that inhibited colon cancer cell proliferation and invasion. These findings identify the FXR-MMP7 axis as a potential therapeutic target for managing colon cancer.

Metalloproteinase-1, Metalloproteinase-7, and p53 Immunoexpression and their Correlation with Clinicopathological Prognostic Factors in Colorectal Adenocarcinoma

Aim

The aim of this study was to analyze the immunoexpression of metalloproteinase-1, metalloproteinase-7, and p53 in colorectal adenocarcinoma, and to correlate this with clinicopathological prognostic factors.

Material and methods

Formalin-fixed paraffin-embedded tumor tissue from 82 patients was analyzed by means of immunohistochemistry, using the streptavidin-biotin method and the tissue microarray technique. Protein tissue expression was correlated with the variables of the degree of cell differentiation, stage, relapse-free survival, recurrence, survival, and specific mortality.

Results

All of the tumors were positive for metalloproteinase-1, while 50 (61%) were positive for metalloproteinase-7, and 32 (39%) were negative for the latter. For p53, 70 (85.4%) of the tumors were positive and 12 (14.6%) were negative. Correlation of the marker expressions separately and in conjunction did not produce any statistically significant data.

Conclusion

The immunoexpression of metalloproteinase-1, metalloproteinase-7, and p53 did not correlate with recurrence, mortality, relapse-free survival, survival, degree of cell differentiation, or staging of colorectal cancer.

Absorption, metabolism, anti-cancer effect and molecular targets of epigallocatechin gallate (EGCG): An updated review

Green tea is one of the most popular beverages in the world, especially in Asian countries. Consumption of green tea has been demonstrated to possess many health benefits, which mainly attributed to the main bioactive compound epigallocatechin gallate (EGCG), a flavone-3-ol polyphenol, in green tea. EGCG is mainly absorbed in the intestine, and gut microbiota play a critical role in its metabolism prior to absorption. EGCG exhibits versatile bioactivities, with its anti-cancer effect most attracting due to the cancer preventive effect of green tea consumption, and a great number of studies intensively investigated its anti-cancer effect. In this review, we therefore, first stated the absorption and metabolism process of EGCG, and then summarized its anti-cancer effect in vitro and in vivo, including its manifold anti-cancer actions and mechanisms, especially its anti-cancer stem cell effect, and next highlighted its various molecular targets involved in cancer inhibition. Finally, the anti-cancer effect of EGCG analogs and nanoparticles, as well as the potential cancer promoting effect of EGCG were also discussed. Understanding of the absorption, metabolism, anti-cancer effect and molecular targets of EGCG can be of importance to better utilize it as a chemopreventive and chemotherapeutic agent.

Regulation of Matrix Metalloproteinase in the Pathogenesis of Diabetic Retinopathy

Diabetic retinopathy, a progressive disease, is the major cause of acquired blindness in the developed countries. Despite cutting-edge research in the field, the exact mechanism of this multifactorial disease remains elusive. Matrix metalloproteinases (MMPs) degrade extracellular matrix and play significant role in regulating intracellular homeostasis. In the pathogenesis of diabetic retinopathy, activation of gelatinase MMPs (MMP-2 and MMP-9) in the retina is an early event, and activated MMPs damage the mitochondria and augment retinal capillary cell apoptosis, a phenomenon which is observed before histopathology characteristic of diabetic retinopathy can be seen. MMPs are regulated by a number of different mechanisms including cleavage of their zymogens, regulation of their tissue inhibitors, and their gene expressions by transcriptional factors and epigenetic modifications. This chapter reviews the current literature about the role of MMPs in the development of diabetic retinopathy, and describes different mechanisms to regulate their activation. With evolving research implicating MMPs in both preneovascularization and neovascularization stages of diabetic retinopathy, they could be an attractive target to inhibit the development/progression of diabetic retinopathy, a disease which has potential to rob vision during the most productive years of a diabetic patient's life.

The role of matrix metalloproteinases in colorectal cancer

In the United States, colorectal cancer (CRC) is the third leading cause of cancer mortality, with limited treatment options for those with advanced disease. Matrix metalloproteinases (MMPs) are important for maintaining extracellular homeostasis but also play a prominent role in cancer cell invasion and dissemination. Expression levels of MMP-1, -2, -7, -9 and -13 correlate with worse outcomes; MMP-12 expression appears to be protective. Hence, MMPs are attractive therapeutic targets. Previous clinical trials using broad-spectrum MMP inhibitors were disappointing because of off-target toxicity and lack of efficacy. Now, the availability of safer, more selective inhibitors has renewed interest in therapeutic targeting of MMPs.

LEF-1 regulates proliferation and MMP-7 transcription in breast cancer cells

Matrix metalloproteinase-7 (MMP-7) is a small secreted proteolytic enzyme with broad substrate specificity. Its expression is associated with tumor invasion, metastasis, and survival in a variety of cancers including breast cancer. Using bioinformatics analysis, a conserved LEF-1 binding site became obvious that is mapped at the promoter region of the genomic MMP-7 locus. Consequently, electrophoretic mobility shift assay demonstrated in vitro binding of LEF-1 to the predicted MMP-7 promoter binding site. Here, we demonstrate that lymphoid enhancer binding factor-1 (LEF-1) is associated with regulation of the proliferation-associated cyclin D1 and a gene encoding MMP-7 in breast cancer cells. Thus, a decrease of LEF-1 expression using LEF-1 siRNA resulted in down-regulation of cyclin D and MMP-7 expression, respectively. Moreover, cell cycle analysis of LEF-1 siRNA-transfected human breast cancer cells revealed a significant arrest in G2/M phase. Taken together, our results indicate a pivotal role of LEF-1 in the regulation of proliferation and MMP-7 transcription in breast cancer cells.

Expression of matrix metalloproteinase-7 is an unfavorable prognostic factor in intrahepatic cholangiocarcinoma

BACKGROUND

Intrahepatic cholangiocarcinoma (IHCC) is a highly malignant neoplasm, but the prognostic factors of IHCC are not yet fully understood. The matrix metalloproteinases (MMPs) are known to be related to tumor viability. The aim of this study was to evaluate the prognostic significance of clinicopathological and immunohistochemical characteristics of resected IHCC.

PATIENTS AND METHODS

From 1996 to 2006, we surgically treated 35 patients with IHCC. Clinicopathological and immunohistochemical characteristics, including expression of MMPs, vascular endothelial growth factor, and epidermal growth factor receptor in the resected specimens, were investigated, and overall survival rates were evaluated with regard to the characteristics using univariate and multivariate analyses.

RESULTS

Univariate analysis revealed the significant prognostic factors to be preoperative serum CEA and CA19-9, intraoperative transfusion, tumor size, surgical margin, lymph node metastasis, invasion of portal and hepatic vein, intrahepatic metastasis, UICC stage, and expression of MMP-7. Subsequent multivariate analysis indicated that MMP-7 was an independent prognostic factor (hazard ratio (HR), 4.698; 95% confidence interval (CI), 0.057-0.866; P = 0.03) along with intrahepatic metastasis (HR, 5.694; 95% CI, 0.029-0.706; P = 0.017).

CONCLUSION

MMP-7 expression is associated with a poor prognosis in patients with resected IHCC.

Effects of Monascus-fermented rice extract on malignant cell-associated neovascularization and intravasation determined using the chicken embryo chorioallantoic membrane model

The traditional Chinese medicine, Hong-Qu, also called red mold rice in the United States and Europe, is used for treating blood stasis, a disorder related to hyperlipidemia and atherosclerosis. In addition to improving metabolic syndrome, extracts from Monascus-fermented rice inhibit the proliferation of various cancer cells in vitro and in vivo. The objective was to examine the effect of red mold rice ethanol extract (RMRE) on angiogenesis, invasion, and metastasis during tumor progression. RMRE significantly inhibited the proliferation of SW480 and SW620 human colorectal carcinoma cells in a dose- and time-dependent manner by using the MTT assay. A capillary-like network morphology was observed after the addition of 20 ng/mL vascular endothelial growth factor or SW620 culture-conditional medium, which was not seen after RMRE treatment. Moreover, spontaneous intravasation into Matrigel grafts of SW620 cells from the upper to the lower layers in the chick embryo chorioallantoic membrane (CAM) model was detected by the polymerase chain reaction (PCR) amplification of human Alu genomic DNA from the lower CAMs in the RMRE-untreated group. Neovascularization increased to 75.3% +/- 11.6% by SW620 cells onplant with Matrigel grafts in the CAM model. However, RMRE significantly reduced CAM neovascularization in a dose-dependent manner. Finally, RMRE effectively decreased the activity of matrix metalloproteinase (MMP)-7 as determined by reverse transcription PCR (RT-PCR), Western blotting, and casein zymography assays. In summary, Monascus-fermented products exert a potent effect on tumor growth and activation, suggesting that they may serve as supplementary agents in adjuvant cancer therapy.

Matrilysin (MMP-7) cleaves C-type lectin domain family 3 member A (CLEC3A) on tumor cell surface and modulates its cell adhesion activity

Matrilysin (MMP-7) plays important roles in tumor progression. Previous studies have suggested that MMP-7 binds to tumor cell surface and promotes their metastatic potential. In this study, we identified C-type lectin domain family 3 member A (CLEC3A) as a membrane-bound substrate of MMP-7. Although this protein is known to be expressed specifically in cartilage, its message was found in normal breast and breast cancer tissues as well as breast and colon cancer cell lines. Because few studies have been done on CLEC3A, we overexpressed its recombinant protein in human cancer cells. CLEC3A was found in the cell membrane, extracellular matrix (ECM), and culture medium of the CLEC3A-expressing cells. CLEC3A has a basic sequence in the NH(2)-terminal domain and showed a strong heparin-binding activity. MMP-7 cleaved the 20-kDa CLEC3A protein, dividing it to a 15-kDa COOH-terminal fragment and an NH(2)-terminal fragment with the basic sequence. The 15-kDa fragment no longer had heparin-binding activity. Treatment of the CLEC3A-expressing cells with MMP-7 released the 15-kDa CLEC3A into the culture supernatant. Furthermore, the 20-kDa CLEC3A promoted cell adhesion to laminin-332 and fibronectin substrates, but this activity was abrogated by the cleavage by MMP-7. These results suggest that CLEC3A binds to heparan sulfate proteoglycans on cell surface, leading to the enhancement of cell adhesion to integrin ligands on ECM. It can be speculated that the cleavage of CLEC3A by MMP-7 weakens the stable adhesion of tumor cells to the matrix and promotes their migration in tumor microenvironments.

Andrographolide could inhibit human colorectal carcinoma Lovo cells migration and invasion via down-regulation of MMP-7 expression

Andrographolide (Andro), a diterpenoid lactone isolated from a traditional herbal medicine Andrographis paniculata, is known to possess multiple pharmacological activities. In our previous study, Andro had been shown to have potent anti-cancer activity against human colorectal carcinoma Lovo cells by inhibiting cell-cycle progression. To further investigate the mechanism for the anti-cancer properties of Andro, it was used to examine the effect on migration and invasion of Lovo cells. The results of wound-healing assay and in vitro transwell assay revealed that Andro inhibited dose-dependently the migration and invasion of Lovo cells under non-cytotoxic concentrations. Using zymographic assay and RT-PCR, the results revealed that Andro diminished the activity and the mRNA and protein levels of MMP-7, but not MMP-2 or MMP-9. The down-regulation of MMP-7 appeared to be via the inactivation of activator protein-1 (AP-1) since the treatment with Andro suppressed the nuclear protein level of AP-1, which was accompanied by a decrease in DNA-binding level of the factor. Taken together, these results indicated that Andro reduces the MMP-7-mediated cellular events in Lovo cells, and provided a new mechanism for its anti-cancer activity.

Matrix metalloproteinase-7 and ADAM-12 (a disintegrin and metalloproteinase-12) define a signaling axis in agonist-induced hypertension and cardiac hypertrophy

BACKGROUND

Excessive stimulation of Gq protein-coupled receptors by cognate vasoconstrictor agonists induces a variety of cardiovascular processes, including hypertension and hypertrophy. Here, we report that matrix metalloproteinase-7 (MMP-7) and a disintegrin and metalloproteinase-12 (ADAM-12) form a novel signaling axis in these processes.

METHODS AND RESULTS

In functional studies, we targeted MMP-7 in rodent models of acute, long-term, and spontaneous hypertension by 3 complementary approaches: (1) Pharmacological inhibition of activity, (2) expression knockdown (by antisense oligodeoxynucleotides and RNA interference), and (3) gene knockout. We observed that induction of acute hypertension by vasoconstrictors (ie, catecholamines, angiotensin II, and the nitric oxide synthase inhibitor N(G)-nitro-l-arginine methyl ester) required the posttranscriptional activation of vascular MMP-7. In spontaneously hypertensive rats, knockdown of MMP-7 (by RNA interference) resulted in attenuation of hypertension and stopped development of cardiac hypertrophy. Quantitative reverse-transcription polymerase chain reaction studies in mouse models of MMP-7 knockdown (by RNA interference) and gene knockout revealed that MMP-7 controlled the transcription of ADAM-12, the major metalloproteinase implicated in cardiac hypertrophy. In mice with angiotensin II-induced hypertension and cardiac hypertrophy, myocardial ADAM-12 and downstream hypertrophy marker genes were overexpressed. Knockdown of MMP-7 attenuated hypertension, inhibited ADAM-12 overexpression, and prevented cardiac hypertrophy.

CONCLUSIONS

Agonist signaling of both hypertension and hypertrophy depends on posttranscriptional and transcriptional mechanisms that involve MMP-7, which is transcriptionally connected with ADAM-12. Approaches targeting this novel MMP-7/ADAM-12 signaling axis could have generic therapeutic potential in hypertensive disorders caused by multiple or unknown agonists.

Matrix metalloproteinase 7 is required for tumor formation, but dispensable for invasion and fibrosis in SMAD4-deficient intestinal adenocarcinomas

Expression of matrix metalloproteinase 7 (MMP7) is increased in the human colorectal carcinomas, and correlates with malignant progression. However, its contribution to colon cancer pathogenesis is not understood thoroughly. To investigate the roles of MMP7 in colon cancer progression, we introduced an Mmp7 knockout mutation into the cis-Apc/Smad4 mutant mouse, a model of invasive colon cancer in which SMAD4-dependent TGF-beta family signaling is inactivated. We demonstrate here that lack of MMP7 reduces the number and size of tumors in the cis-Apc/Smad4 mice. On the other hand, MMP7-deficiency does not affect the depth of tumor invasion, number of stromal fibroblasts or levels of extracellular matrix components in the tumors. These results indicate that MMP7 is required for tumor formation, but not for the invasion or fibrosis of the colon cancer whose SMAD4-dependent TGF-beta family signaling is blocked.

Active matrix metalloproteinase-7 is associated with invasion in buccal squamous cell carcinoma

Protein microarrays have shown that matrix metalloproteinase-7 is upregulated in head and neck squamous cell carcinomas, but its role in local tissue invasion is still uncertain. We investigated the expression of active matrix metalloproteinase-7, using tissue microarray, immunohistochemistry, and western blotting, in oral tissues from 24 patients with buccal squamous cell carcinoma, and correlated the findings with clinicopathological features. Normal buccal tissue samples from the same patients, obtained at sites at least 1 cm from tumor tissue, served as normal controls. Total matrix metalloproteinase-7 was detected on western blots in 9 of 15 (60%) tumor tissue samples and in 2 of 15 (13%) normal mucosal samples; this difference was significant (P=0.008). Moreover, the active matrix metalloproteinase-7 was expressed only in eight of the nine (89%) tumor samples that expressed matrix metalloproteinase-7, and in none of the normal tissue samples, regardless of the expression status of the pro-matrix metalloproteinase-7. Immunostaining of matrix metalloproteinase-7 was observed histologically in both tumor and nonneoplastic epithelium, but immunostaining of active matrix metalloproteinase-7 was present only in tumor nests. Expression of active matrix metalloproteinase-7 was associated with larger tumor size (P=0.022) and was significantly higher in buccal squamous cell carcinoma with adjacent skin or bone invasion (P=0.036). In conclusion, active matrix metalloproteinase-7 expression was associated with more aggressive buccal squamous cell carcinomas.

Metaloproteinases 1 e 7 e câncer colorretal

A metaloproteinase-1 (MMP-1) e a metaloproteinase-7 (MMP-7) são proteinases da matriz extracelular (MEC), zinco-dependentes, envolvidas no processo inicial da carcinogênese por permitirem a invasão tumoral na célula e promover o processo de metastatização. O polimorfismo dessas proteinases tem sido estudado recentemente com o objetivo de validar susa expressão e/ou atividade como marcador prognóstico. Evidências cumulativas revelam importante papel das MMP's 1 e 7 em diferentes fases da carcinogênese. A MMP-1 tem ação direta sobre a principal proteína da MEC, que é o colágeno do tecido intersticial conectivo. Sua expressão aumentada neste tecido pode indicar alto potencial de disseminação tumoral em diferentes tipos de câncer, incluindo o colorretal. A associação deste aumento da expressão também parece ser verdadeira para a MMP-7.

Intracellular expression of a single-chain antibody directed against type IV collagenase inhibits the growth of lung cancer xenografts in nude mice

It was documented that type IV collagenase with two subtypes of 72 ku/MMP-2 and 92 ku/MMP-9 plays an important role in tumor invasion and metastasis. The endoplasmic reticulum (ER)-retained, single chain Fv antibody fragment (scFv) was used to inhibit the function of type IV collagenase. For expression in mammalian cells, the assembled scFv M97 gene with ER retention signal encoding 6 additional amino acids (SEKDEL) was reamplified by PCR. The amplified fragments were cloned into the pcDNA3.1 vector. The resulting plasmid was sequenced and then introduced into PG cells, a highly metastatic human lung cancer cell line, by lipofectAMINE method. The result of intrabody gene therapy showed that type IV collegenase expression was down regulated significantly as measured by ELISA. The biological behavior of PG cell, such as the ability of in vitro invasion through Matrigel, colony formation on soft agar, was also inhibited by scFv M97 transfection. Animal experiments in a xenograft model of human lung cancer showed that scFv M97 transfection significantly prolonged the survival time of nude mice. The results indicate that intracellular antibody technology represents a novel and efficient way to abrogate selectively the activity of type IV collagenase.

Matrilysin (matrix metalloprotease-7) cleaves membrane-bound annexin II and enhances binding of tissue-type plasminogen activator to cancer cell surfaces

Matrilysin (matrix metalloproteinase-7) plays important roles in tumor progression. It was previously found that matrilysin binds to the surface of colon cancer cells to promote their metastatic potential. In this study, we identified annexin II as a novel membrane-bound substrate of matrilysin. Treatment of human colon cancer cell lines with active matrilysin released a 35 k Da annexin II form, which lacked its N-terminal region, into the culture supernatant. The release of the 35 k Da annexin II by matrilysin was significantly enhanced in the presence of serotonin or heparin. Matrilysin hydrolyzed annexin II at the Lys9-Leu10 bond, thus dividing the protein into an N-terminal nonapeptide and the C-terminal 35 k Da fragment. Annexin II is known to serve as a cell surface receptor for tissue-type plasminogen activator (tPA). Although the matrilysin treatment liberated the 35 k Da fragment of annexin II from the cell surface, it significantly increased tPA binding to the cell membrane. A synthetic N-terminal nonapeptide of annexin II bound to tPA more efficiently than intact annexin II. This peptide formed a heterodimer with intact annexin II in test tubes and on cancer cell surfaces. These and other results suggested that the nonapeptide generated by matrilysin treatment might be anchored to the cell membrane, possibly by binding to intact annexin II, and interact with tPA via its C-terminal lysine. It is supposed that the cleavage of cell surface annexin II by matrilysin contributes to tumor invasion and metastasis by enhancing tPA-mediated pericellular proteolysis by cancer cells.

Human leukocyte elastase counteracts matrix metalloproteinase-7 induced apoptosis resistance of tumor cells

Matrix metalloproteinase-7 (MMP-7/Matrilysin) is a component of the tumor microenvironment associated with malignant progression. Its expression in tumors protects tumor cells from CD95-mediated apoptosis and the cytotoxic activity of tumor specific CD8(+) T cells. In the present study, we show that human leukocyte elastase (HLE) secreted by polymorphonuclear leukocytes cleaves MMP-7 resulting in loss of enzymatic activity. The anti-apoptotic effect of MMP-7 is reduced in the presence of HLE for CD95-, doxorubicin- and CTL-mediated apoptosis. Our data indicates that HLE may be a natural inactivator of MMP-7 which can counteract MMP-7-induced apoptosis resistance.

Garcinol modulates tyrosine phosphorylation of FAK and subsequently induces apoptosis through down-regulation of Src, ERK, and Akt survival signaling in human colon cancer cells

Garcinol, from the fruit rind of Garcinia indica and other species, has been reported to suppress colonic aberrant crypt foci (ACF) formation in rats. In this study, we investigate the beneficial effects of tumor prevention by garcinol on the human colorectal cancer cell line, HT-29. Focal adhesion kinase (FAK) is the major signaling mediator of integrin-mediated cell-matrix contact-regulated cellular proliferation, migration, and apoptosis in adherent cells. Results of Matrigel analysis show that exposure of HT-29 cells to 10 microM garcinol inhibited cell invasion, and decreased the dose-dependent tyrosine phosphorylation of FAK. We further demonstrate by Western blot analysis that garcinol inhibited activation of the Src, MAPK/ERK, and PI3K/Akt signaling pathways. To investigate whether the loss of integrin-mediated cell-matrix contact can induce apoptosis, we demonstrate that garcinol induced it in HT-29 cells. The apoptotic dose of garcinol (20 microM) changed the ratio of the anti-apoptotic Bcl-2 and proapoptotic BAX proteins within 12 h, which correlated with a release of cytochrome c from the mitochondria to the cytosol, and with PARP cleavage. Additionally, we demonstrate that a decreasing MMP-7 protein level in HT-29 cells results in sensitization to garcinol. Garcinol also significantly inhibited the expression of MMP-7 in IL-1beta-induced HT-29 cells. These results suggest that garcinol reduces cell invasion and survival through the inhibition of FAK's downstream signaling.

Endocrine gland-derived vascular endothelial growth factor (EG-VEGF) expression in colorectal cancer

BACKGROUND AND OBJECTIVES

Vascular endothelial growth factor (VEGF) is known as an important factor in the growth and metastasis of cancer cells. In 2001, a novel angiogenesis factor, endocrine gland-derived vascular endothelial growth factor (EG-VEGF), was cloned. In this study, we investigated the expression of EG-VEGF in colorectal cancer, the relationship between its expression and clinicopathological factors, and the in vitro activity of EG-VEGF transfectants.

METHODS

We determined expression levels of EG-VEGF in 113 advanced colorectal cancers resected in our hospital by quantitative PCR, and compared the expression levels and clinicopathological findings by multivariate analyses.

RESULTS

The expression of EG-VEGF mRNA was positive in 31 cancers and negative in 82 cancers. We found that compared with the negative expression of the EG-VEGF gene, its positive expression was more frequently associated with hematogenous metastasis, and was associated with a poorer survival rate. In addition, EG-VEGF transfectants showed a higher degree of in vitro tubular formation than control cells.

CONCLUSIONS

We speculate that, in colorectal cancers, the EG-VEGF gene functions as an important factor in angiogenesis in primary and metastatic lesions, and consider that it is useful as a novel prognostic factor. EG-VEGF molecule-targeted therapy has the potential for improving survival rates.

Expression of matrix metalloproteinase-7 on cancer cells and tissue endothelial cells in renal cell carcinoma: prognostic implications and clinical significance for invasion and metastasis

PURPOSE

The expression of matrix metalloproteinase-7 (MMP-7) correlates with the malignant potential of various tumors and patient survival. We investigated the clinical and prognostic significance of MMP-7 expression in cancer cells and endothelial cells in human renal cell carcinoma (RCC).

EXPERIMENTAL DESIGN

We reviewed tissue samples of 156 patients with RCC who had undergone radical operation. MMP-7 expression was examined by immunohistochemistry. Sections containing MMP-7-positive vessels were also stained for CD34. The density of MMP-7-positive vessels was determined by a computer-aided image analysis system. Multivariate analysis was done to assess relevant variables for invasion, metastasis, and cause-specific survival.

RESULTS

The proportion of MMP-7-expressing tumor cells were significantly higher (P < 0.001) than that of normal cells. MMP-7-positive vessels were considered blood vessels based on staining for CD34, and their density was increased in tumor areas. The proportion of MMP-7-expressing cancer cells and density of MMP-7-positive vessels correlated with grade, pathologic tumor stage, and metastasis. Multivariate analysis showed that MMP-7 expression on cancer cells correlated with pathologic tumor stage only, whereas MMP-7-positive vessel density correlated with metastasis only. The elevated status of MMP-7 in cancer tissues was an independent predictor for cause-specific survival (odds ratio, 8.61; P = 0.040) by multivariate analysis.

CONCLUSIONS

Our results showed that MMP-7 influences tumor progression by regulating invasion and angiogenesis. Multivariate analysis showed that MMP-7 status of cancer tissues was strong predictor of poor prognosis. Our results suggest that MMP-7 targeting treatment may be a potential target against RCC.

Is there a genetic signature for liver metastasis in colorectal cancer?

Even though liver metastasis accounts for the vast majority of cancer deaths in patients with colorectal cancer (CRC), fundamental questions about the molecular and cellular mechanisms of liver metastasis still remain unanswered. Determination of gene expression profiles by microarray technology has improved our knowledge of CRC molecular pathways. However, defined gene signatures are highly variable among studies. Expression profiles and molecular markers have been specifically linked to liver metastases mechanistic paths in CRC. However, to date, none of the identified signatures or molecular markers has been successfully validated as a diagnostic or prognostic tool applicable to routine clinical practice. To obtain a genetic signature for liver metastasis in CRC, measures to improve reproducibility, to increase consistency, and to validate results need to be implemented. Alternatives to expression profiling with microarray technology are continuing to be used. In the recent past, many genes codifying for proteins that are directly or indirectly involved in adhesion, invasion, angiogenesis, survival and cell growth have been linked to mechanisms of liver metastases in CRC.

Serum matrix metalloproteinase 7 levels identifies poor prognosis advanced colorectal cancer patients

Metalloproteinase 7 (MMP-7) plays an important role in tumor growth, invasion and dissemination, and is secreted to the media. Because of the close implication of MMP-7 in cancer biology, we sought to define the prognostic significance of serum levels of MMP-7 in metastatic colorectal cancer (CRC) and explore its possible impact in the daily clinical practice. MMP-7 expression was determined by enzyme-linked immunoabsorbent assay. We assessed serum MMP-7 levels in 87 healthy controls, 96 patients with nonmetastatic CRC and 120 patients with advanced CRC. Clinical information was gathered from patient files. Cox proportional hazards model was used to assess survival. MMP-7 and the variables associated with prognosis were entered and a backward elimination method was employed to adjust the model. Inclusion criteria was p </= 0.05 and exclusion criteria was p >/= 0.10. Advanced CRC patients have a significant higher mean serum MMP-7 levels (13.4 ng/ml) than those in nonmetastatic CRC (5.5 ng/ml; p < 0.001) and healthy controls (4.2 ng/ml; p < 0.001). In metastatic patients, after adjusting for other prognostic variables, MMP-7 (entered as a continuous variable) is associated with decreased survival (HR 1.016, IC 95% 1.002-1.031). Serum MMP-7 levels are significantly elevated in patients with advanced CRC. In conclusion, MMP-7 is an independent prognostic factor for survival in advanced CRC. In our sample, the risk of death associated to MMP-7 increase is much higher than the risk of death associated to lactate dehydrogenase elevation.

Expression of Matrix Metalloproteinase-10 in Renal Cell Carcinoma and Its Prognostic Role

OBJECTIVES

Matrix metalloproteinase (MMP)-10 is associated with malignant aggressiveness in various cancers, but its importance has not been investigated in conventional renal cell carcinoma (CRCC). The purpose of this study was to determine the clinical significance and malignant potential of MMP-10 in human CRCC tissues.

PATIENTS AND METHODS

Specimens were obtained from 103 CRCC patients who underwent radical surgery and were examined by immunohistochemistry for MMP-10 expression. The proportions of Ki-67-stained cells (proliferation index: PI) and densities of CD34-positive vessels (microvessel density: MVD) were measured by a computer-aided image analysis system. The relationships between MMP-10 expression and clinicopathologic features and various parameters including tumour size, PI, MVD, and survival were investigated by univariate and multivariate analyses.

RESULTS

MMP-10 expression was mainly detected in cancer cell cytoplasm, and 45 (43.7%) CRCCs were considered MMP-10-positive. MMP-10 expression correlated with grade (p=0.006) and pT stage (p<0.001), and it was a significant and independent factor for high pT stage in multivariate analysis model. MMP-10 expression was associated with MVD (p = 0.022) but not tumour size or PI. MMP-10 expression in CRCC was a significant predictor of poor outcome by log-rank test (p = 0.013) but not by multivariate analysis.

CONCLUSIONS

MMP-10 seems to play an important role in renal cancer cell invasion and is a potentially useful therapeutic target to prevent CRCC tumour progression.

Regulation of matrix metalloproteinase gene expression

The metalloproteinases degrade extracellular matrix (ECM) components and activate growth factors, thereby contributing to physiological events (tissue remodeling in pregnancy, wound healing, angiogenesis) and pathological conditions (cancer, arthritis, periodontitis). The intent of this review is to bring together various studies on transcriptional and post-transcriptional control of metalloproteinase expression. Certainly, much information is known as to the cis-elements and corresponding trans-activators regulating expression of these genes. We discuss the fact that a number of the metalloproteinase promoters share common structural features and, therefore, not surprisingly are co-regulated in their expression to some extent. More recently, much effort has been devoted to understanding the role of chromatin in regulating gene expression. While this area has been understudied with respect to matrix metalloproteinase (MMP) regulation, the literature indicates a convincing role for both histone modifications and chromatin-remodeling motors in controlling expression of multiple metalloproteinases. In addition to transcriptional control, mRNA stability and protein translation also contribute to the metalloproteinase product amount. We discuss such studies and how various biological cues, including TGF-beta, regulate the levels of certain collagenases either solely through mRNA stabilization or by jointly targeting transcriptional and post-transcriptional mechanisms. We also discuss the current deficits in our knowledge, concerning tissue-specific expression and why despite elevated amounts/activity of trans-activators targeting MMP promoters in tumor cells, nevertheless, MMP expression is largely restricted to the stromal compartment. Finally, we argue for potential technologies to regulate MMP expression of utility in pathological conditions where these enzymes are aberrantly expressed.

Elevated activities of MMP-2 in the non-tumorous lung tissues of curatively resected stage I NSCLC patients are associated with tumor recurrence and a poor survival

BACKGROUND AND OBJECTIVES

We wanted to assess whether the level of enzyme activity for a particular matrix metalloproteinase (MMP), and not the amount of expressed protein, in lung tissue could be used as a reliable prognostic biomarker for tumor recurrence leading to poorer survival in a certain subgroup of patients who have undergone curative resection for stage I human NSCLC.

METHODS

We determined what type of MMP was significant for tumor recurrence by using a mouse model of pulmonary metastasis with inoculating the footpad with H460 human cancer cells. We then looked for any association between tumor recurrence and the level of enzyme activities for the selected MMP in the tumor and also in the pathologically non-tumorous tissues from 34 stage I lung cancer patients.

RESULTS

We obtained H460/PM6 cells having a highly metastatic potential after six repeated cycles of pulmonary metastasis by using the mouse footpad inoculated with the metastasized cancer cells in the previous cycle. We started with human lung cancer cells, H460, and we found that among the tested MMPs we tested for, the level of MMP-2 mRNA was elevated. No significant difference was seen in the level of enzyme activity of the MMP-2 cells from the curatively resected tumor tissues of the stage I NSCLC patients who were later found with or without recurrence. However, the level of MMP-2 enzyme activity was found to be significantly different between the non-tumorous lung tissues from patients later found with and without recurrence, and it was associated with the 5-year survival rate.

CONCLUSIONS

This observation suggests that the higher level of MMP-2 enzyme activity in the non-tumorous tissues from the patients could be used as a prognostic biomarker to predict post-operative tumor recurrence and survival for patients with stage I NSCLC. The elevated enzyme activity of MMP-2 in the non-tumorous tissue resected from stage I NSCLC could be used as a prognostic indicator for post-operative tumor recurrence and the patients' poor survival. Further, this could be an important aid for physicians' making decision on whether to subject particular patients to post-operative adjunct chemotherapy.

[The role of matrix metalloproteinases and tissue inhibitors of metalloproteinases in invasion of tumours of neuroepithelial tissue]

Tumour invasion requires degradation of extracellular matrix components and migration of cells through degraded structures into surrounding tissues. Matrix metalloproteinases (MMP) constitute a family of zinc and calcium-dependent endopeptidases that play a key role in the breakdown of extracellular matrix, and in processing of cytokines, growth factors, chemokines and cell surface receptors. Their activity is regulated at the levels of transcription, activation and inhibition by tissue inhibitors of metalloproteinases (TIMP). Changes in expression of MMP and TIMP are implicated in tumour invasion, because they may contribute to both migration of tumour cells and angiogenesis. Alterations of MMP expression observed in brain tumours arouse interest in the development and evaluation of synthetic matrix metalloproteinase inhibitors as antitumour agents.

The role of matrix metalloproteinases-2, -7 and -9 and ?-catenin in high grade endometrial carcinoma

AIMS

To determine the expression of matrix metalloproteinases (MMPs)-2, -7 and -9 and beta-catenin in uterine serous carcinoma (USC) and endometrioid endometrial carcinoma (EEC) and to investigate any difference in expression between EEC and USC which might explain the mechanism of invasion and aggressive behaviour of USC.

METHODS AND RESULTS

Tissue microarrays were created from the viable central part and from the invasive edge of 20 cases of grade 3 EEC and 73 cases of USC. Immunohistochemistry was performed using antibodies to MMPs-2, -7 and -9 and beta-catenin. MMPs-2, -7 and -9 and beta-catenin were present in both tumour types; there was significantly higher expression of MMPs-2 and -9 in EEC compared with USC and significantly increased expression of MMPs-2 and -9 by carcinoma cells at the invasive edge of USC.

CONCLUSIONS

MMPs-2, -7 and -9 and beta-catenin are present in EEC and USC. The increased expression of MMPs-2 and -9 by carcinoma cells at the invasive edge of USC is possibly due to increased binding of MMPs secreted by the stromal cells to carcinoma cells, thus equipping the USC carcinoma cells with proteases for invasion.

Auraptene decreases the activity of matrix metalloproteinases in dextran sulfate sodium-induced ulcerative colitis in ICR mice

Previously we reported that auraptene was a potent suppressant for matrix metalloproteinase (MMP)-7 expression in HT-29 human colon cancer cells. In the present study, we examined the effects of auraptene on MMP-2, -7, and -9 expression in colonic mucosa from dextran sulfate sodium (DSS)-induced ulcerative colitis mice. Auraptene remarkably suppressed the DSS-induced gelatinolytic activity of MMP-7 as well as the expression of MMP-2 and -9, suggesting that it might be useful in anti-metastatic therapies via the targeting of MMPs.

Inhibition of Matrilysin Expression by Antisense or RNA Interference Decreases Lysophosphatidic Acid–Induced Epithelial Ovarian Cancer Invasion

Our previous reports show that matrilysin [matrix metalloproteinase (MMP)-7] is overexpressed in epithelial ovarian cancer (EOC) and recombinant MMP-7 promotes EOC invasion in vitro. In the present study, we further evaluated the correlation of MMP-7 expression to EOC invasiveness and examined its role in lysophosphatidic acid (LPA)-induced invasion. By sense and antisense gene transfection in vitro, we show that overexpression of MMP-7 in all MMP-7 stably transfected DOV13 clones significantly enhanced their invasiveness, although MMP-7 antisense transfection caused a 91% decrease of MMP-7 expression (P < 0.01) and 87% decrease of invasion (P < 0.05) in geneticin (G418)-selected DOV13 clone P47-M7As-3 compared with vector-transfected control. As assessed by MMP-7 ELISA, LPA treatment at 10 to 80 micromol/L significantly stimulated the secretion of total MMP-7 in DOV13 conditioned medium (P < 0.01). In addition, LPA apparently induced the activation of MMP-7 in DOV13 cells as detected by gelatin zymography. In the antisense MMP-7-transfected DOV13 clone (P47-M7As-3), LPA-increased invasion was significantly decreased compared with vector control. Moreover, knocking down of MMP-7 by small interfering RNA also suppressed LPA-induced invasion in two EOC cell lines (DOV13 and R182). Altogether, our results show that MMP-7 expression is correlated with EOC invasiveness and LPA-induced MMP-7 secretion/activation may represent a new mechanism that facilitates ovarian cancer invasion besides the well-known induction of MT1-MMP-mediated proMMP-2 activation by LPA.

Citrus auraptene targets translation of MMP-7 (matrilysin) via ERK1/2-dependent and mTOR-independent mechanism

Matrix metalloproteinase (MMP)-7 is considered to play essential roles in cancer progression. We examined the efficacy of auraptene, a citrus coumarin derivative, for suppressing MMP-7 expression in the human colorectal adenocarcinoma cell line HT-29. Auraptene remarkably inhibited the production of proMMP-7 protein, without affecting its mRNA expression level. Rapamycin, an inhibitor of mammalian target of rapamycin (mTOR), showed similar results, suggesting that auraptene suppresses mTOR-dependent proMMP-7 translation. Interestingly, however, auraptene showed no effects on the activation of Akt/mTOR signaling, whereas the phosphorylation levels of 4E binding protein (4EBP)1 and eukaryotic translation initiation factor (eIF)4B were substantially decreased. In addition, auraptene remarkably dephosphorylated constitutively activated extracellular signal-regulated kinase (ERK)1/2. Transfection of ERK1/2 siRNA led to a significant reduction of proMMP-7 protein production as well as of the phosphorylation of eIF4B. These results demonstrate that auraptene targets the translation step for proMMP-7 protein synthesis by disrupting ERK1/2-mediated phosphorylation of 4EBP1 and eIF4B.

Regulation of matrilysin expression in endothelium by fibroblast growth factor-2

Matrilysin (MMP7) is a secreted matrix metalloproteinase, which contributes to angiogenesis by breaking down basement membranes. We show that the angiogenic factor FGF-2 induces MMP7 expression in human endothelial cells. The promoter contains a Lef/Tcf consensus sequence, but using wildtype or Lef/Tcf-mutated promoter constructs, FGF-2-induced MMP7 reporter activity is independent from Lef/Tcf sites. Instead, we show that overexpression of a dominant negative Stat3 mutant reduces FGF-2-mediated MMP7 promoter activity. However, Stat3 does not bind to the MMP7 promoter, but activates MMP7 gene expression indirectly via AP-1. This is confirmed by MMP7 promoter constructs with mutated AP-1 sites which did not respond to FGF-2 and by siRNAs against Stat1 and Stat3, which repressed FGF-2-induced MMP7 protein expression. In conclusion, we show that FGF-2-induced MMP7 expression in endothelium depends on AP-1 and FGF-2 signaling to AP-1 involves a Stat1/3-dependent pathway.

The intrinsic mitochondrial membrane potential of colonic carcinoma cells is linked to the probability of tumor progression

We subcloned cell lines from SW620 cells establishing that, despite the dynamic nature of the mitochondrial membrane potential (Deltapsim), there are significant and stable differences in the intrinsic Deltapsim among cells within an in vitro population of human colonic carcinoma cells. Whereas more dramatic differences in Deltapsim would likely perturb essential mitochondrial functions, the differences in Deltapsim of the subclones did not affect steady-state reactive oxygen species levels, electron transport activity, or cellular viability and growth rates. However, the differences in intrinsic Deltapsim had a significant effect on the tumorigenic behavior of the cells. Subcloned cell lines with higher Deltapsim were more likely to exhibit elevated steady-state levels of vascular endothelial growth factor and matrix metalloproteinase 7, and increased invasive behavior (properties associated with tumor progression), than cells with lower intrinsic Deltapsim, whereas cells with lower Deltapsim were more likely to respond to the chemopreventive activities of butyrate, including Deltapsim dissipation, growth arrest, and apoptosis, than cells with higher Deltapsim. Therefore, these data establish that the probability for tumor development and progression is linked to stable differences in the intrinsic Deltapsim of colonic epithelial cells.

Targeting matrilysin and its impact on tumor growth in vivo: the potential implications in breast cancer therapy

INTRODUCTION

Matrilysin (MMP-7) is a metalloproteinase that is involved in the degradation of extracellular matrix, invasion, and tumor progression. The current study examined if targeting matrilysin using retroviral ribozyme transgenes may have an impact on breast cancer cells and may have clinical implications.

EXPERIMENTAL DESIGN

Retroviral hammerhead ribozyme transgenes were designed to specifically target human matrilysin mRNA. The breast cancer cell MDA-MB-231 was transfected with either a retroviral matrilysin transgene or a control retroviral transgene. Stably transfected cells were tested for their invasiveness and migratory properties in vitro. The cells were also used in creating a tumor model in athymic nude mice in which the growth of tumors and levels of matrilysin were assessed. In addition, levels of both protein and mRNA of matrilysin were investigated in a cohort of human breast tumors.

RESULTS

Expression of matrilysin in MDA-MB-231 was successfully eliminated by the retroviral hammerhead ribozyme transgene for matrilysin as revealed by reverse transcription-PCR. Matrilysin transgene-transduced cancer cells (MDA-MB-231DeltaMatrilysin) exhibited a significantly lower degree of invasion (number of invading cells 16.0 +/- 2.5) compared with wild type (MDA-MB-231(WT); 26.2 +/- 6.2, P < 0.05) or control transgene-transduced cancer cells (MDA-MB-231pRevTRE; 25.3 +/- 4.2, P < 0.01). However, the rate of growth of the cells in vitro was not significantly affected. In the in vivo tumor model, MDA-MB-231DeltaMatrilysin tumors, which had very low levels of immunoreactive matrilysin, grew at a significantly lower rate (0.24 +/- 0.03 cm3, 4 weeks after inoculation) compared with the wild-type MDA-MB-231(WT) (1.46 +/- 0.04 cm3) and MDA-MB-231pRevTRE (1.12 +/- 1.0 cm3) tumors. In human breast tumors, breast cancer cells stained matrilysin at a significantly higher density, compared with normal mammary epithelium. The highest level of matrilysin was seen in high-grade tumors and that from patients with moderate and poor prognosis. Finally, high levels of matrilysin were significantly linked with a poor long-term survival (P = 0.0143).

CONCLUSION

Matrilysin, which is aberrantly expressed in human breast tumors, can be effectively eliminated from breast cancer cells by way of hammerhead ribozyme transgene. Elimination of matrilysin is associated with low invasiveness and slow tumor growth. Taken together, the study suggests that targeting matrilysin may have important therapeutic implications.

Collagenases in cancer

Three mammalian collagenases (MMP-1, MMP-8, and MMP-13) belong to family of matrix metalloproteinases and are the principal secreted endopeptidases capable of cleaving collagenous extracellular matrix. In addition to fibrillar collagens, collagenases can cleave several other matrix and non-matrix proteins including growth factors, and this way regulate cell growth and survival. Collagenases are important proteolytic tools for extracellular matrix remodeling during organ development and tissue regeneration, but they also apparently play important roles in many pathological situations and tumor progression and metastasis. Because of their potentially destructive characteristics the expression and activity of collagenases are strictly controlled. Synthesis of collagenases is regulated by extracellular signals via cellular signal transduction pathways at transcriptional and post-transcriptional level. Collagenases are synthesized as inactive pro-forms, and once activated, their activity is inhibited by specific tissue inhibitors of metalloproteinases, TIMPs, as well as by non-specific proteinase inhibitors. In this review we discuss the current view on the role of collagenases in tumor growth, invasion, and metastasis, as a basis for their feasibility in diagnosis and prognostication, as well as therapeutic targets in cancer patients.

Matrilysin over-expression in MCF-7 cells enhances cellular invasiveness and pro-gelatinase activation

Matrilysin (MMP-7) is over-expressed in various cancers and is thought to play important roles in tumor invasion and metastasis. However, the function of MMP-7 in breast cancer remains unclear. We therefore examined the expression of the MMP-7 gene in breast cancer (MCF-7) cells and the effect of its over-expression on cellular invasion. We transfected human MMP-7 into MCF-7 cells and selected clones that stably over-expressed the MMP-7 gene. The in vitro invasiveness of MCF-7 cells was quantified by use of the Matrigel invasion assay. Expression of MMP-7 mRNA was analyzed by quantitative RT-PCR. MMP secretion and activation were detected by gelatin zymography. We found that MMP-7-expressing clones had significantly increased invasion (P < 0.001), with increased MMP-7 expression and gelatinase activation as compared to the vector controls. We conclude that MMP-7 over-expression correlates with breast cancer in vitro invasiveness and that MMP-7 may promote invasion by increasing the secretion and activation of proMMP-2 and proMMP-9.

The molecular mechanisms of oesophageal cancer

Apoptosis is a process of programmed cell death, which is as essential as cell growth, for the maintenance of homeostasis. When these processes loose integration such as cancer, then uncontrolled cell growth occurs. Cancer of the oesophagus ranks as the ninth most common malignancy in the world, and recent evidence shows that its incidence is increasing. Prognosis of this disease is poor, with an overall 5-year survival rate of less than 10%. Unraveling the mechanisms or developing animal models for oesophageal carcinoma have thus far not been successful. It is believed that oesophageal cancer has an intricate molecular mechanism of evading apoptosis by the down-regulation of Bax, up-regulation of Bcl-2, Bcl-xl and Survivin, mutation of p53 and alteration in Fas expression. A great deal of research has been performed in order to determine the key genes that initiate and promote the growth of oesophageal cancer. This review focuses on apoptosis and candidate genes linked to the development of oesophageal cancer, which it is hoped may provide diagnostic and therapeutic tools, and potential therapeutic strategies for the management of this carcinoma.

(-)-Epigallocatechin-3-gallate promotes pro-matrix metalloproteinase-7 production via activation of the JNK1/2 pathway in HT-29 human colorectal cancer cells

Matrix metalloproteinase (MMP)-7 (matrilysin-1) plays significant roles in the growth, invasion, and metastasis of colorectal tumors, while (-)-epigallocatechin-3-gallate (EGCG), a green tea polyphenol with chemopreventive properties, has been shown to be an inhibitor of MMP-2 and MMP-9. In the present study, HT-29 human colorectal cancer cells were treated with EGCG to examine its effects on pro-MMP-7 induction and production using RT-PCR and western blot analyses. Surprisingly, EGCG (10-100 microM) treatment increased both intracellular and extracellular pro-MMP-7 protein levels (2.6-8.4-fold and 1.9-6.4-fold, respectively) in dose- and time-dependent manner, with a significant upregulation of its mRNA expression. EGCG also activated extracellular signal-regulated protein kinase (ERK)1/2, c-JUN NH2-terminal kinase (JNK)1/2 and p38 mitogen-activated protein kinase (MAPK), as previously reported. In addition, the polyphenol triggered the phosphorylation of c-JUN (Ser63 and Ser73) and induced c-JUN/c-FOS, thereby increasing the DNA binding activity of activator protein-1 (AP-1), as shown by an AP-1 luciferase reporter assay. Pharmacological blockade of MAPK activities suggested that pro-MMP-7 expression was induced via JNK1/2 activation, but not in the case of ERK1/2 or p38 MAPK. N-Acetyl-L-cysteine, superoxide (O2-) dismutase and catalase attenuated the EGCG-induced pro-MMP-7 production, suggesting an involvement of oxidative stress in these events. Conversely, EGCG spontaneously generated O2- in a cell-free system that utilized a cytochrome C reduction method. Further, (-)-epicatechin-3-gallate (25 and 100 microM) and green tea polyphenols (33 and 132 microg/ml) induced pro-MMP-7 expression, whereas (-)-epicatechin and (-)-epigallocatechin (100 microM each) did not. Induction of pro-MMP-7 expression by EGCG was also shown in another human colorectal adenocarcinoma cell line, Caco-2. Our results suggest that some green tea catechins induce pro-MMP-7 production via O2- production and the activation of JNK1/2, c-JUN, c-FOS and AP-1 in HT-29 cells.

Regulation of matrix metalloproteinases: an overview

Matrix metalloproteinases (MMPs) are a major group of enzymes that regulate cell-matrix composition. MMP genes show a highly conserved modular structure. Ample evidence exists on the role of MMPs in normal and pathological processes, including embryogenesis, wound healing, inflammation, arthritis, cardiovascular diseases, pulmonary diseases and cancer. The expression patterns of MMPs have interesting implications for the use of MMP inhibitors as therapeutic agents. Insights might be gained as to the preference for a general MMP inhibitor as opposed to an inhibitor designed to be specific for certain MMP family members as it relates to a defined disease state, and may give clues to potential side effects. The signalling pathways that lead to induction of expression of MMPs are still incompletely understood, but certain patterns are beginning to emerge. Regarding inhibition of MMP expression at the level of kinase pathways, it is possible that selective chemical inhibitors for distinct signalling pathways (e.g. MAPK, PKC) will hopefully, soon be available for initial clinical trials. Overexpression of selective dual specificity MAPK phosphatases have been shown to prevent MMP promoter activation which could also be used as a novel strategy to prevent activation of AP-1 and ETS transcription factors and MMP promoters in vivo. Interactions between members of different transcription factors provide fine-tuning of the transcriptional regulation of MMP promoter activity. MMPs play a crucial role in tumor invasion. Although the expression of MMPs in malignancies has been studied widely, the specific role of distinct MMPs in the progression of cancer may be more complex than has been assumed. For example, it has recently been shown that MMP-3, MMP-7, MMP-9 and MMP-12 can generate angiostatin from plasminogen, indicating that their expression in peritumoral area may in fact serve to limit angiogenesis and thereby inhibit tumor growth and invasion. The recent view about the role of stromal cells in the progression of cancer cell growth and metastasis is particularly interesting, and additional studies about the regulation of MMP gene expression and activity in malignancies are needed to understand the role and regulation of MMPs in tumor cell invasion.

Regulation of matrix metalloproteinases: an overview

Matrix metalloproteinases (MMPs) are a major group of enzymes that regulate cell-matrix composition. MMP genes show a highly conserved modular structure. Ample evidence exists on the role of MMPs in normal and pathological processes, including embryogenesis, wound healing, inflammation, arthritis, cardiovascular diseases, pulmonary diseases and cancer. The expression patterns of MMPs have interesting implications for the use of MMP inhibitors as therapeutic agents. Insights might be gained as to the preference for a general MMP inhibitor as opposed to an inhibitor designed to be specific for certain MMP family members as it relates to a defined disease state, and may give clues to potential side effects. The signalling pathways that lead to induction of expression of MMPs are still incompletely understood, but certain patterns are beginning to emerge. Regarding inhibition of MMP expression at the level of kinase pathways, it is possible that selective chemical inhibitors for distinct signalling pathways (e.g. MAPK, PKC) will hopefully, soon be available for initial clinical trials. Overexpression of selective dual specificity MAPK phosphatases have been shown to prevent MMP promoter activation which could also be used as a novel strategy to prevent activation of AP-1 and ETS transcription factors and MMP promoters in vivo. Interactions between members of different transcription factors provide fine-tuning of the transcriptional regulation of MMP promoter activity. MMPs play a crucial role in tumor invasion. Although the expression of MMPs in malignancies has been studied widely, the specific role of distinct MMPs in the progression of cancer may be more complex than has been assumed. For example, it has recently been shown that MMP-3, MMP-7, MMP-9 and MMP-12 can generate angiostatin from plasminogen, indicating that their expression in peritumoral area may in fact serve to limit angiogenesis and thereby inhibit tumor growth and invasion. The recent view about the role of stromal cells in the progression of cancer cell growth and metastasis is particularly interesting, and additional studies about the regulation of MMP gene expression and activity in malignancies are needed to understand the role and regulation of MMPs in tumor cell invasion.

Matrix metalloproteinase-7 facilitates insulin-like growth factor bioavailability through its proteinase activity on insulin-like growth factor binding protein 3

Matrix metalloproteinase-7 (MMP-7) secreted by cancer cells has been implicated classically in the basement membrane destruction associated with tumor cell invasion and metastasis. Recent epidemiologic studies have established a correlation between high levels of circulating insulin-like growth factor (IGF) and low levels of IGF binding protein 3 (IGFBP-3), and relative risk of developing colon, breast, prostate, and lung cancer, which are known to produce MMP-7. In this study, IGFBP-3 was assessed as a candidate for the physiologic substrate of MMP-7. MMP-7 proteolysis generated four major fragments (26 kDa, 17 kDa, 15.5 kDa, and 15.5 kDa), and two cleavage sites were identified: one at the site of hydrolysis of the K(144)-I(145) peptide bond and one at the R(95)-L(96) peptide bond. The former site is different from the previously reported site of cleavage of IGFBP-3 by other proteases. Addition of IGFBP-3 inhibited IGF-I-mediated IGF type 1 receptor (IGF-IR) phosphorylation and activation of the downstream molecule Akt in BALB/c 3T3 fibroblasts overexpressing human IGF-IR (3T3-IGF-IR) and in two human colon cancer cell lines (COLO201 and HT29). Coincubation of the IGF-I/IGFBP-3 complex with MMP-7 restored IGF-I-mediated IGF-IR phosphorylation and activation of Akt in these cell lines. The IGF-I signal recovered by MMP-7 protected against apoptosis induced by anoikis in 3T3-IGF-IR cells. These results indicate that MMP-7 proteolysis of IGFBP-3 plays a crucial role in regulating IGF-I bioavailability, thereby promoting cell survival. This mechanism may contribute to the tumorigenesis of MMP-7-producing IGF-IR-expressing tumors in the primary site and to organ-specific metastasis in a paracrine manner.

New insights into the roles of matrix metalloproteinases in colorectal cancer development and progression

This review outlines new concepts that are emerging for the functions of matrix metalloproteinases in colorectal cancer development and progression. The two main concepts that will be discussed are the role of matrix metalloproteinases in the early stages of colorectal tumour development and the functional mechanisms by which matrix metalloproteinases contribute to colorectal tumour invasion and metastasis. The matrix metalloproteinases are a group of enzymes, which have been best characterized for their ability to degrade extracellular matrix proteins and thus they have been extensively studied in tumour invasion. It is now becoming recognized that the matrix metalloproteinases have key roles in a variety of biological processes that are distinct from their well-defined role in matrix degradation. This group of enzymes has been shown to interact with a broad range of non-matrix proteins including growth factors and their receptors, mediators of apoptosis, and cell adhesion molecules. The elucidation of novel biological roles for the matrix metalloproteinases also challenges the current predominant concept of matrix metalloproteinases as enzymes only involved in matrix degradation. Recent studies have shown that several matrix metalloproteinases, especially matrilysin (MMP-7), interact with the specific molecular genetic and signalling pathways involved in colorectal cancer development. In particular, matrilysin is activated at an early stage of colorectal tumourigenesis by the beta-catenin signalling pathway. Furthermore, studies are now elucidating specific mechanisms by which individual matrix metalloproteinases, especially membrane-type matrix metalloproteinases, interact with specific cell adhesion molecules and cytoskeletal proteins and thus contribute dynamically to colorectal tumour invasion.

Matrilysin (MMP-7) induces homotypic adhesion of human colon cancer cells and enhances their metastatic potential in nude mouse model

Matrilysin (MMP-7) is thought to contribute to invasive growth and metastasis of colon carcinoma and many other human cancers. The present study demonstrates that treatment of human colon carcinoma cells with active matrilysin induces cell aggregation in vitro and promotes liver metastasis in nude mice. When two kinds of colon carcinoma cell lines were incubated with active matrilysin, this enzyme efficiently bound to the cell surface and induced loose cell aggregation, which led to E-cadherin-mediated tight cell aggregation. Synthetic MMP inhibitors inhibited both the membrane binding of matrilysin and matrilysin-induced cell aggregation, while TIMP-2 inhibited only the cell aggregation. Two other active MMPs, stromelysin and gelatinase A, neither bound to cell membrane nor induced cell aggregation. Tumor cells in loose cell aggregates could reaggregate even after they were freed from matrilysin and dispersed. When injected into the spleen of nude mice, the tumor cells in the stable aggregates produced much larger metastatic nodules in the livers than control cells and those in the loose aggregates. These results suggest that matrilysin may enhance metastatic potential of tumor cells by processing a cell surface protein(s) and thereby inducing loose and then tight aggregation of tumor cells.

Development of matrix metalloproteinase inhibitors in cancer therapy

The matrix metalloproteinases represent an attractive target for cancer treatment, and a number of matrix metalloproteinase inhibitors are undergoing clinical trials. The results of these studies will establish whether any of these compounds are therapeutically useful. Independent of the conclusions from the first generation of studies, the field of matrix metalloproteinase inhibitors remains attractive for creative and innovative research. In the future, the development of novel, less toxic, and more effective matrix metalloproteinase inhibitors, and the combination of conventional agents with these novel anticancer agents will constitute the main focus of research efforts.

Down-regulation of cathepsin-D expression by antisense gene transfer inhibits tumor growth and experimental lung metastasis of human breast cancer cells

Overexpression of cathepsin-D in primary breast cancer has been associated with rapid development of clinical metastasis. To investigate the role of this protease in breast cancer growth and progression to metastasis, we stably transfected a highly metastatic human breast cancer cell line, MDA-MB-231, with a plasmid containing either the full-length cDNA for cathepsin-D or a 535 bp antisense cathepsin-D cDNA fragment. Clones expressing antisense cathepsin-D cDNA that exhibited a 70-80% reduction in cathepsin-D protein, both intra- and extracellularly compared to controls, were selected for further experiments. These antisense-transfected cells displayed a reduced outgrowth rate when embedded in a Matrigel matrix, formed smaller colonies in soft agar and presented a significantly decreased tumor growth and experimental lung metastasis in nude mice compared with controls. However, manipulating the cathepsin-D level in the antisense cells has no effect on their in vitro invasiveness. These studies demonstrate that cathepsin-D enhances anchorage-independent cell proliferation and subsequently facilitates tumorigenesis and metastasis of breast cancer cells. Our overall results provide the first evidence on the essential role of cathepsin-D in breast cancer, and support the development of a new cathepsin-D-targeted therapy.

Matrix metalloproteinases in tumor invasion: role for cell migration

Matrix metalloproteinases (MMP) play a role in a wide range of tumorigenesis, including early carcinogenesis events, tumor growth and tumor invasion and metastasis. Given that the ability of tumor cells to infiltrate and disseminate widely is what makes the tumors malignant, a role of MMP in cell migration during this invasive and metastatic process is important. There are two types of cancer cell migration: single cell locomotion and cohort migration (cell movement en mass keeping cell-cell contact, which is frequently seen in better differentiated carcinomas). Cell surface localization and activation of MMP is essential for cells to migrate, through rearrangement of extracellular matrix (ECM) to suit cell migration. Certain MMP, such as gelatinases and membrane -type 1 MMP, have special mechanisms to localize at leading edges in both types of cell migration. Moreover, in cohort migration, expression of these MMP is regulated via cell-cell contact within migrating cell sheets and confined to the foremost pathfinder cells of the migrating cell sheets. New roles of cell surface MMP, such as cleavage of cell surface receptors or cofactors involved in cell-ECM interactions during cell migration, are also discussed.

MMP-7 (matrilysin) accelerated growth of human umbilical vein endothelial cells

Matrix metalloproteinases (MMP) are considered to play important roles in angiogenesis. In angiogenic processes, endothelial cells secrete MMP-2 or MMP-1 to dissolve the basement membrane or connective tissue around the vessels. MMP-7 (matrilysin) is secreted from the neovasculars induced by cancer and is a metastatic factor of colorectal cancer. The effect of matrilysin on angiogenesis is still unclear, however. We therefore examined the effect of MMP-7 on the proliferation of human umbilical vein endothelial cells (HUVECs) in vitro. Our results showed that recombinant MMP-7 (rMMP-7) accelerated the proliferation of endothelial cells dose-dependently, and did so for endothelial cells cultured not only on type IV collagen, but also on type I collagen. MMP-7 also upregulated MMP-1, -2 secretion, but did not stimulate vascular endothelial growth factor (VEGF) secretion. From this study, we conclude that MMP-7 directly induces angiogenesis, and that therefore MMP-7 would be a good target of cancer therapy.