Type IV collagenases in tumor invasion and metastasis

Matrix metalloproteinase-12 is associated with overall survival in Chinese patients with gastric cancer

BACKGROUND AND OBJECTIVES

Matrix metalloproteinase-12 (MMP-12) plays an important role in invasion and metastasis of human solid tumor cells. This study aimed to investigate the association of MMP-12 with overall survival in human gastric cancer.

METHODS

Gastric cancer and adjacent normal tissue specimens were collected from 165 patients who had not received neoadjuvant chemotherapy. MMP-12 expression was determined by immunohistochemical staining, and the results were analyzed statistically in relation to the overall survival of the patients.

RESULTS

MMP-12 expression was increased in gastric cancer compared with that observed in normal tissues. Increased MMP-12 expression was associated with tumor invasion, lymph node metastasis, distant metastasis, and TNM stage. No correlations were detected between MMP-12 expression and age, sex, differentiation status, tumor site, or Lauren classification. Moreover, patients with MMP-12 positive gastric cancer tended to have worse overall survival compared with those patients without MMP-12 expression.

CONCLUSIONS

The study results showed that increased expression of MMP-12 was associated with tumor progression in gastric cancer. It also provided the first evidence for MMP-12 expression in gastric cancer as an independent prognostic factor.

Matrix metalloproteinase-9 expression is increased in astrocytic glioma and associated with prognosis of patients

OBJECTIVE

Glioma is the most common type of primary central nervous system tumor. This study was aimed at investigating the expression of matrix metalloproteinase-9 in astrocytic glioma samples and its association with clinicopathological characteristics as well as survival of patients.

METHODS

Astrocytic glioma samples from 272 patients who had not received chemotherapy or radiotherapy were collected, in which matrix metalloproteinase-9 expression was assessed by immunochemistry assays. The association of staining evaluation results with clinicopathological characteristics was analyzed by appropriate statistical analysis. Kaplan-Meier analysis and Cox proportional hazards regression models were used to investigate the association between matrix metalloproteinase-9 expression and survival of patients.

RESULTS

Results showed that matrix metalloproteinase-9 expression is increased in astrocytic glioma and associated with tumor progression as its expression increased from Grade II to Grade IV glioma (P<0.001). Kaplan-Meier analysis showed that patients with glioma with higher matrix metalloproteinase-9 expression tend to have shorter overall survival time (P<0.001). In multivariate analysis, matrix metalloproteinase-9 expression was proved to be an independent prognostic factor for patients with astrocytic glioma (P<0.001).

CONCLUSIONS

This study confirmed the overexpression of matrix metalloproteinase-9 and its association with tumor progression in astrocytic glioma. It also provided the first evidence that matrix metalloproteinase-9 expression in glioma was an independent prognostic factor of patients, which might be a potential diagnostic and therapeutic target of astrocytic glioma.

Modulation of u-PA, MMPs and their inhibitors by a novel nutrient mixture in human female cancer cell lines

Cancers of the breast, cervix, uterus and ovary are the most prevalent cancers in women worldwide. Proteases play a key role in tumor cell invasion and metastasis by digesting the basement membrane and ECM components. Strong clinical and experimental evidence demonstrates association of elevated levels of urokinase plasminogen activators (u-PA) and matrix metalloproteinases (MMPs) with cancer progression, metastasis and shortened patient survival. MMP activities are regulated by specific tissue inhibitors of metalloproteinases (TIMPs). Our main objective was to study the effect of a nutrient mixture (NM) on the activity of u-PA, MMPs and TIMPs in human breast, cervix, uterine and ovarian cancer cell lines. Human breast (MDA-MB-231 and MCF-7), cervical (HeLa), uterine (SK-UT-1) and ovarian (SKOV3) cancer cell lines were cultured in their respective media and treated at confluence with NM at 0, 50, 100, 250, 500 and 1000 μg/ml. Analysis of u-PA activity was carried out by fibrin zymography, MMPs by gelatinase zymography and TIMPs by reverse zymography. Both breast and uterine cancer cell lines expressed u-PA, which was inhibited by NM in a dose-dependent manner. However, no bands corresponding to u-PA were detected for HeLa and SK-OV-3 cell lines. On gelatinase zymography, MDA-MB-231 and MCF-7 showed one band corresponding to MMP-9, HeLa showed two bands, an intense band corresponding to MMP-2 and a faint band corresponding to MMP-9, SK-UT-1 showed PMA-induced MMP-9, and SK-OV-3 showed a band corresponding to MMP-2. NM inhibited their expression in all cell lines. The activity of TIMPs was upregulated in all cancer cell lines in a dose-dependent manner. Analysis revealed a positive correlation between u-PA and MMPs and a negative correlation between u-PA/MMPs and TIMPs. These findings suggest the therapeutic potential of NM in the treatment of female cancers.

Arsenic trioxide inhibits Ewing's sarcoma cell invasiveness by targeting p38(MAPK) and c-Jun N-terminal kinase

Ewing's sarcoma is the second most frequent primary malignant bone tumor, mainly affecting children and young adults. The notorious metastatic capability of this tumor aggravates patient mortality and remains a problem to be overcome. We investigated the effect of arsenic trioxide (As₂O₃) on the metastasis capability of Ewing's sarcoma cells. We performed 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazolium bromide assays to choose appropriate concentrations of As₂O₃ for the experiments. Migration, invasion, and adhesion assays were performed to assess the effect of As₂O₃ on the metastasis of Ewing's sarcoma. Immunofluorescent staining was used to observe cytoskeleton reorganization in Ewing's sarcoma cells treated with As₂O₃. Changes in matrix metalloproteinase-9 expression and the mitogen-activated protein kinase (MAPK) pathway were investigated using western blot. Inhibitors of p38(MAPK) (sb202190) and c-Jun NH₂-terminal kinase (JNK, sp600125) were used in invasion assays to determine the effect of p38(MAPK) and JNK. We found that As₂O₃ may markedly inhibit the migration and invasion capacity of Ewing's sarcoma cells with structural rearrangements of the actin cytoskeleton. The expressions of matrix metalloproteinase-9, phosphor-p38(MAPK), and phosphor-JNK were suppressed by As₂O₃ treatment in a dose-dependent manner. The inhibitors of p38(MAPK) (sb202190) and JNK (sp600125) enhanced the inhibition induced by As₂O₃, which was counteracted by anisomycin, an activating agent of p38(MAPK) and JNK. Taken together, our results demonstrate that As₂O₃ can inhibit the metastasis capability of RD-ES and A-673 cells and may have new therapeutic value for Ewing's sarcoma.

Expression of ezrin, MMP-9, and COX-2 in 50 chordoma specimens: a clinical and immunohistochemical analysis

STUDY DESIGN

Retrospective study.

OBJECTIVE

To investigate the immunohistochemical expression profile of ezrin, matrix metalloproteinase-9 (MMP-9), and cyclooxygenase-2 (COX)-2 in chordomas.

SUMMARY OF BACKGROUND DATA

Ezrin, MMP-9, and COX-2 are expressed in different solid tumors, including chordomas. This study investigates the immunohistochemical expression of the aforementioned biomarkers and the clinical outcome in regard to immunohistochemistry, tumor volume, and localization.

METHODS

Fifty brachyury-verified chordoma specimens of 34 primary and 16 recurrent tumors of 44 patients were tested for ezrin, MMP-9, and COX-2 as possible therapeutical targets by immunohistochemistry. The clinical evaluation concentrated on tumor location, volume, and age-related data.

RESULTS

Ezrin expression was detected in 33 of 34 primary chordomas and in 16 of 16 recurrent cases. The primary chordomas located in the sacrum and the spine demonstrated a significantly higher percentage of positively stained tumor cells (P = 0.034) than the skull-based chordomas. An expression of MMP-9 and COX-2 was observed in 33 of 34 primary chordomas and in 16 of 16 recurrences, and in 13 of 34 primary chordomas and in 11 of 16 recurrences, respectively. Patients' survival was significantly influenced by age (P = 0.01), tumor location (P = 0.029), and tumor volume (P = 0.002). A significant positive correlation between tumor volume and the anatomic distance of the chordoma from the skull was calculated (P = 0.00002).

CONCLUSION

En bloc resection with tumor-free margins is seldom feasible, particularly in the sacrum. Intralesional excisions mostly end in early local recurrence; therefore, the demand for further treatment options is frequently posed. The marked trend of the investigated biomarkers of this study may build a starting point for further investigations as molecular targets for future adjuvant therapies in chordomas. Future multicenter studies on larger patients' series are necessary to elucidate these preliminary data and to test new treatment options for patients with chordomas.

Micronutrient Synergy in the Fight against Hepatocellular Carcinoma

The incidence of hepatocellular carcinoma (HCC), once thought to be a rare tumor in North America, has rapidly increased in recent years in the United States. Current treatment modalities to halt the progression of this disease are only marginally effective. The mainstay treatment is liver transplantation, which is often confronted with donor shortage. Invasion, metastasis and recurrence contribute to the high mortality rate of this disease. Matrix metalloproteinases (MMPs) that degrade the extracellular matrix (ECM) have been associated with the progression, invasion and metastasis of the disease. We have developed strategies to strengthen the ECM collagen and inhibit MMPs through micronutrients such as lysine, proline and ascorbic acid. Addition of epigallocatechin gallate or green tea extract to these micronutrients synergistically enhanced anti-carcinogenic activity in HepG2 cells. Addition of certain other micronutrients, such as N-acetylcysteine, selenium, copper and zinc (NM) synergistically enhanced the anticancer activity of the mixture in a model of hepatocellular carcinoma using HepG2 cells. In vitro studies using HepG2 demonstrated that NM was very effective in inhibiting cell proliferation (by MTT assay), MMPs secretion (by gelatinase zymography), cell invasion (through Matrigel) and induction of apoptosis (by live green caspase). In addition, NM was shown to down-regulate urokinase plasminogen activator (by fibrin zymography) and up-regulate tissue inhibitors of metalloproteinases (by reverse zymography) in another HCC cell line, SK-Hep-1. MMP-2 and MMP-9 activities were further modulated by phorbol 12-myristate 13-acetate (PMA) induction and inhibited by NM. In previous studies, NM inhibited Sk-Hep-1 xenografts in nude mice and also inhibited hepatic metastasis of B16FO melanoma cells. Our results suggest that NM is an excellent candidate for therapeutic use in the treatment HCC by inhibiting critical parameters in cancer development and progression, such as proliferation, invasion and metastasis, and by inducing apoptosis.

Increased expression of matrix metalloproteinase-13 in glioma is associated with poor overall survival of patients

Glioma is the most common and aggressive tumor in human central nervous system. MMP-13 plays an important role in tumor aggressive process for it can degrade the extracellular matrix of basement membranes. The present study was to investigate the expression of MMP-13 in clinical glioma samples and its association with clinicopathological characteristics as well as survival of patients. Clinical glioma samples from 286 patients who had not received chemotherapy or radiotherapy were collected, in which MMP-13 expression was assessed by immunochemistry assays. The association of staining evaluation results with clinicopathological characters was analyzed by appropriate statistical analysis. Kaplan-Meier analysis and Cox proportional hazards regression models were used to investigate the associations of MMP-13 expression with survival of patients. Results showed that MMP-13 expression was increased in glioma and associated with tumor progression for its expression increased from grade I to grade IV glioma (P<0.001). Kaplan-Meier analysis showed that patients of glioma with higher MMP-13 expression tend to have shorter overall survival time (P<0.001). In multivariate analysis, MMP-13 expression was proved to be an independent prognostic factor for patients with glioma (P<0.001). The present study confirmed the over-expression of MMP-13 and its association with tumor progression in glioma. It also provided the first evidence that MMP-13 expression in glioma was an independent prognostic factor of patients, which might be a potential diagnostic and therapeutic target of glioma.

Kuguacin J, a triterpeniod from Momordica charantia leaf, modulates the progression of androgen-independent human prostate cancer cell line, PC3

In this study, we focused on the in vitro effects of Kuguacin J (KuJ), a purified component of bitter melon (Momordica charantia) leaf extract (BMLE), on the androgen-independent human prostate cancer cell line PC3 and the in vivo effect of dietary BMLE on prostate carcinogenesis using a PC3-xenograph model. KuJ exerted a strong growth-inhibitory effect on PC3 cells. Growth inhibition was mainly through G1-arrest: KuJ markedly decreased the levels of cyclins (D1 and E), cyclin-dependent kinases (Cdk2 and Cdk4) and proliferating cell nuclear antigen. Interestingly, KuJ also dramatically decreased the levels of survivin expressed by PC3 cells. In addition, KuJ exerted anti-invasive effects on PC3 cells, significantly inhibiting migration and invasion: KuJ inhibited secretion of the active forms of MMP-2, MMP-9 and uPA by PC3 cells. In addition, KuJ treatment significantly decreased the expression of membrane type 1-MMP (MT1-MMP) by PC3 cells. In vivo, 1% and 5% BMLE in the diet resulted in 63% and 57% inhibition of PC3 xenograft growth without adverse effect on host body weight. Our results suggest that KuJ is a promising new candidate chemopreventive and chemotherapeutic agent for prostate cancer.

Human leucine zipper protein sLZIP induces migration and invasion of cervical cancer cells via expression of matrix metalloproteinase-9

Extracellular proteolysis mediates tissue homeostasis. In cancer, altered proteolysis leads to abnormal tumor growth, inflammation, tissue invasion, and metastasis. Matrix metalloproteinase-9 (MMP-9) represents one of the most prominent proteinases associated with inflammation and tumorigenesis. The recently identified human transcription factor sLZIP is a member of the leucine zipper transcription factor family. Although sLZIP is known to function in ligand-induced transactivation of the glucocorticoid receptor, its exact functions and target genes are not known. In this study, we investigated the role of sLZIP in MMP-9 expression and its involvement in cervical cancer development. Our results show that sLZIP increased the expression of MMP-9 at both the mRNA and protein levels and the proteolytic activity of MMP-9 in HeLa and SiHa cells. sLZIP also increased the transcriptional activity of MMP-9 by binding directly to the cAMP-responsive element of the MMP-9 promoter region. Involvement of sLZIP in MMP-9 expression was further supported by the fact that ME-180 cells expressing sLZIP siRNA were refractory to MMP-9 expression. Results from wound healing and invasion assays showed that sLZIP enhanced both the migration and invasion of cervical cancer cells. The increased migration and invasion of HeLa and SiHa cells that were induced by sLZIP were abrogated by inhibition of the proteolytic activity of MMP-9. These results indicate that sLZIP plays a critical role in MMP-9 expression and is probably involved in invasion and metastasis of cervical cancer.

In vitro antimetastatic effect of Changweiqing through antiinvasion of hypoxic colorectal carcinoma LoVo cells

OBJECTIVE

To investigate the in vitro effects and the primary mechanisms of Changweiqing (, CWQ) on antimetastasis and antiinvasion of hypoxic colon carcinoma cells. In addition, to provide experimental evidence for the Chinese medicinal theory of "strengthening the body's resistance to eliminate pathogenic factors" in the treatment of colorectal cancer, including its invasion and metastasis.

METHODS

First, CWQ sera were prepared with serum-pharmacology methods. Then, the modified hypoxic chamber was designed and flushed with 5% CO(2) and 95% N(2) at 37 °C to induce a hypoxic environment. The effect of CWQ serum on the viability of LoVo cells was tested with MTT cytotoxicity assay. The wound model and chamber model were established to estimate the effects of CWQ serum on migration and invasion of LoVo cells. The model for cell adhesion was established to evaluate the effect of CWQ serum on LoVo cells' adhesion. The gelatin zymography model was performed to determine the effects of CWQ serum on the activities of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9). The effects of CWQ serum on the hypoxia-inducible factor 1 α (HIF-1α) nuclear translocation and the mRNA level of vascular endothelial growth factor (VEGF) in LoVo cells were determined by Western blot and reverse transcription-polymerase chain reaction (RT-PCR) analyses, respectively.

RESULTS

CWQ inhibited LoVo cells' migration based on wound healing assay. The inhibitive effect could reach about 68.00% under hypoxic culture and about 29.87% under normoxic culture when cells were treated with 10% CWQ serum for 24 h. The results from both cell invasion and adhesion assays showed that CWQ serum could dose-dependently repress the invasion of LoVo cells and inhibit cells from adhering to extra cellular matrix (ECM). Under the hypoxic culture condition, RT-PCR analysis showed that 10% CWQ serum had down-regulated the expression of VEGF by 45.87%, and the result of Western blot analysis provided further evidence. The HIF-1α amount in the nucleus of the LoVo cells was also diminished in a dose-dependent manner, as shown by the Western blot. Gel zymogram assay revealed that CWQ serum could suppress the activities of MMP-2 and MMP-9.

CONCLUSIONS

CWQ could effectively inhibit tumor metastasis in vitro The antimetastatic effects of CWQ were associated with the inhibition of cell motility, which was evidenced by inhibition of cell invasion and adhesion. The molecular mechanisms of the inhibition of tumor invasion by CWQ were due to the reduced expression of both HIF-1α and VEGF and the suppression of MMP-2 and MMP-9 expression.

Overexpression of matrix metalloproteinase-21 is associated with poor overall survival of patients with colorectal cancer

INTRODUCTION

Matrix metalloproteinase-21 (MMP-21) is a member of the MMP family, which is overexpressed in some solid tumors and is thought to enhance the tumor invasion and metastasis ability. The aim of the present study is to examine the MMP-21 expression in human colorectal cancer and normal colorectal tissue using tissue microarray technique and to determine its association with clinicopathological characteristics and prognostic value.

MATERIALS AND METHODS

Four array blocks including 256 cases of colorectal cancer and adjacent normal tissues were investigated by immunohistochemistry assay. Staining evaluation results were analyzed statistically in relation to various clinicopathological characters and overall survival.

RESULTS

High level of MMP-21 expression was detected in colorectal cancer, significantly more than in normal colorectal epithelial cells. In colorectal cancer, MMP-21 was significantly positively correlated with depth of invasion, lymph node metastasis, and distant metastasis. The overall survival rate was significantly lower for patients with MMP-21 positive than those with MMP-21 negative tumors. However, no correlations between MMP-21 expression and patients' age, sex tumor location, or differentiation status were detected.

CONCLUSION

Our findings emphasize the important role of MMP-21 in the invasion and metastasis process in human colorectal cancer. It might also serve as a novel prognostic marker that is independent of, and additive to, the TNM staging system.

Identification of high-risk stage II and stage III colorectal cancer by analysis of MMP-21 expression

BACKGROUND

The expression of matrix metalloproteinase-21 (MMP-21) has been shown to be elevated in some solid tumor and thought to enhance tumor invasion and metastasis ability. In the present study, we investigated the expression of MMP-21 and its association with prognosis in stage II and III colorectal cancer.

METHODS

MMP-21 expression was investigated in 286 cases of colorectal cancer by immunohistochemistry assay. Statistical analysis was utilized to evaluate the association of MMP-21 expression with clinicopathological characters and overall survival of patients with stage II and III colorectal cancer.

RESULTS

MMP-21 expression was significantly higher in colorectal cancer, compared with that in normal epithelial tissue. And it also correlated with tumor invasion, lymph node metastasis, and distant metastasis of colorectal cancer. MMP-21 was also proved to be an independent prognostic factor in patients with stage II as well as stage III colorectal cancer. However, no correlations between MMP-21 expression and patients' age, sex, tumor location, or differentiation status were detected.

CONCLUSION

These results suggested the potential role of MMP-21 in the invasion and metastasis process of human colorectal cancer. It could also be a novel molecular marker to predict prognosis of patients with stage II and stage III colorectal cancer.

Tissue inhibitor of matrix metalloproteinase-1 mediates erythropoietin-induced neuroprotection in hypoxia ischemia

Previous studies have shown that erythropoietin (EPO) is neuroprotective in both in vivo and in vitro models of hypoxia ischemia. However these studies hold limited clinical translations because the underlying mechanism remains unclear and the key molecules involved in EPO-induced neuroprotection are still to be determined. This study investigated if tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) and its upstream regulator signaling molecule Janus kinase-2 (JAK-2) are critical in EPO-induced neuroprotection. Hypoxia ischemia (HI) was modeled in-vitro by oxygen and glucose deprivation (OGD) and in-vivo by a modified version of Rice-Vannucci model of HI in 10-day-old rat pups. EPO treated cells were exposed to AG490, an inhibitor of JAK-2 or TIMP-1 neutralizing antibody for 2h with OGD. Cell death, phosphorylation of JAK-2 and signal transducers and activators of transcription protein-3 (STAT-3), TIMP-1 expression, and matrix metalloproteinase-9 (MMP-9) activity were measured and compared with normoxic group. Hypoxic ischemic animals were treated one hour following HI and evaluated 48 h after. Our data showed that EPO significantly increased cell survival, associated with increased TIMP-1 activity, phosphorylation of JAK-2 and STAT-3, and decreased MMP-9 activity in vivo and in vitro. EPO's protective effects were reversed by inhibition of JAK-2 or TIMP-1 in both models. We concluded that JAK-2, STAT-3 and TIMP-1 are key mediators of EPO-induced neuroprotection during hypoxia ischemia injury.

Matrix metalloproteinase-2 (MMP-2) and -9 (MMP-9) in preoperative serum as independent prognostic markers in patients with colorectal cancer

Colorectal cancer is one of the leading causes of cancer related death in developed countries. One of the reasons is the absence of tumor specific diagnostic and prognostic markers. The aim of this study was to examine the correlation of matrix metalloproteinase-2 (MMP-2) and -9 (MMP-9) expressions in serum and clinicopathological features of the colorectal adenocarcinoma. Another aim was to examine expression of MMP-9 in the tissue of the colorectal carcinoma in MMP-9 serum positive patients. In addition, we tried to establish the correlation between preoperative levels of serum markers (CEA and CA 19-9) and presence of MMP-2 or MMP-9. The study was performed on 32 patients with colorectal adenocarcinoma who underwent surgery and 11 patients in a control group who were operated for benign diseases. The samples were analyzed by SDS-PAGE to determine the molecular mass and SDS-PAGE zymography to determine levels of MMP-2 and MMP-9. Expression of MMP-9 was determined immunohistochemically in the tissue of the colorectal carcinoma of MMP-9 serum positive patients. MMP-2 and MMP-9 levels were increased in the serum of the patients with colorectal cancer compared to the control group. There was significant correlation in MMPs levels among the patients with tumor stage I and II and the patients with tumor stage III and IV. Obtained results did not demonstrate correlation between levels of CEA, CA 19-9 and presence of MMP-2 or MMP-9. MMP-9 expression was positive in 85% of MMP-9 serum positive patients with colorectal carcinoma. The overexpression of MMP-2 and MMP-9 strongly suggests its association with colorectal adenocarcinoma. Detection of MMP-2 and MMP-9 in serum might be useful for identification of patients with higher risk for colorectal cancer recurrence.

Matrix metalloproteinase-9 is associated with relapse and prognosis of patients with colorectal cancer

BACKGROUND

Matrix metalloproteinase-9 is a member of the MMP family, which is overexpressed in some solid tumors and is thought to enhance tumor invasion and metastasis ability. The present study aims to examine MMP-9 expression in human colorectal cancer and to determine its association with clinicopathological characteristics and prognosis.

METHODS

Colorectal cancer and adjacent normal tissues from 192 patients were investigated by immunohistochemical assay. Staining evaluation results were analyzed statistically in relation to various clinicopathological characters, disease-free survival, and overall survival.

RESULTS

High level of MMP-9 expression was detected in colorectal cancer, significantly more than in normal colorectal epithelial cells. In colorectal cancer, MMP-9 was significantly positively correlated with depth of invasion, lymph node metastasis, and distant metastasis. However, no correlations between MMP-9 expression and patient age, sex, tumor location or differentiation status were detected. Disease-free and overall survival were significantly poorer for patients with positive MMP-9 staining than for those with MMP-9-negative tumors.

CONCLUSIONS

Our findings emphasize the important role of MMP-9 in the invasion and metastasis process in human colorectal cancer. It could also serve as a novel prognostic marker that is independent of, and additive to, the tumor-node-metastasis (TNM) staging system.

L-cysteine as a regulator for arsenic-mediated cancer-promoting and anti-cancer effects

Previous studies have shown that activities of tyrosine kinases and secretion of the active form of matrix metalloproteinase-2 (MMP-2) are correlated with promotion of tumor growth, while apoptotic cell death in cancer cells is correlated with anti-cancer effects. Although arsenic has been reported to have both cancer-promoting and anti-cancer effects, the mechanisms of the arsenic-mediated bidirectional effects remain unknown. We examined the effects of arsenic on both proto-oncogene c-RET-transfected NIH3T3 cells with benign characters and oncogenic RET-MEN2A-transfected NIH3T3 cells with malignant characters. Arsenic promoted not only c-RET tyrosine kinase activity but also genetically activated RET-MEN2A kinase activity with promotion of dimer formation of RET proteins. Arsenic also increased secretion of the active form of MMP-2 in both RET-MEN2A-transfectants and c-RET-transfectants. On the other hand, arsenic promoted poly-(ADP-ribose) polymerase (PARP) degradation and cell death in both malignant and non-malignant cells. Interestingly, l-cysteine inhibited the arsenic-mediated tumor-promoting effects (activation of kinases and MMP-2 secretion) but not arsenic-mediated anti-cancer effects (PARP degradation and cell death). Our results suggest redox-linked regulation of arsenic-mediated activities of kinases and MMP-2 secretion but not arsenic-mediated cell death. Our results also suggest that l-cysteine is an ideal supplement that inhibits arsenic-mediated tumor-promoting effects without affecting arsenic-mediated anti-cancer effects.

Matrix metalloproteinase-9 is associated with disease-free survival and overall survival in patients with gastric cancer

Matrix metalloproteinase-9 is a member of the Matrix metalloproteinases (MMP) family, which is overexpressed in some solid tumor and thought to enhance the tumor invasion and metastasis ability. Our study is to investigate the association of MMP-9 expression with disease-free survival and overall survival of patients with gastric cancer. Clinical gastric cancer specimens and adjacent normal tissues from 286 patients who had not received neoadjuvant chemotherapy were investigated by immunohistochemistry assay. Staining evaluation results were analyzed statistically in relation to various clinicopathological characters, disease-free survival and overall survival. High level of MMP-9 expression was detected in gastric cancer, significantly more than in adjacent normal epithelial cells. In gastric cancer, MMP-9 was significantly positively correlated with depth of invasion, lymph node metastasis and distant metastasis. However, no correlations between MMP-9 expression and patients' age, sex, tumor location or differentiation status were detected. The disease-free survival and overall survival were significantly shorter for patients with MMP-9 positive than those with MMP-9 negative tumors. Multivariate analysis identified MMP-9 was an independent prognostic factor for both disease-free survival and overall survival. Our findings provided convincing evidence for MMP-9 as an important role in human gastric cancer recurrence and prognosis. It might also serve as a novel target for both prognostic prediction and therapeutics.

Matrix metalloproteinase-9 and cell division in neuroblastoma cells and bone marrow macrophages

Matrix metalloproteinases (MMPs) degrade the extracellular matrix and carry out key functions in cell development, cancer, injury, and regeneration. In addition to its well recognized extracellular action, functional intracellular MMP activity under certain conditions is supported by increasing evidence. In this study, we observed higher gelatinase activity by in situ zymography and increased MMP-9 immunoreactivity in human neuroblastoma cells and in bone marrow macrophages undergoing mitosis compared with resting cells. We studied the pattern of immunoreactivity at the different stages of cell division by confocal microscopy. Immunostaining with different monoclonal antibodies against MMP-9 revealed a precise, dynamic, and well orchestrated localization of MMP-9 at the different stages of cell division. The cellular distribution of MMP-9 staining was studied in relation to that of microtubules. The spatial pattern of MMP-9 immunoreactivity suggested some participation in both the reorganization of the nuclear content and the process of chromatid segmentation. We then used several MMP-9 inhibitors to find out whether MMP-9 might be involved in the cell cycle. These drugs impaired the entry of cells into mitosis, as revealed by flow cytometry, and reduced cell culture growth. In addition, the silencing of MMP-9 expression with small interfering RNA also reduced cell growth. Taken together, these results suggest that intracellular MMP-9 is involved in the process of cell division in neuroblastoma cells and in primary cultures of macrophages.

Momordica charantia leaf extract suppresses rat prostate cancer progression in vitro and in vivo

Cancer metastasis is a major cause of death in cancer patients, with invasion as a first step greatly contributing to the failure of clinical treatments. Any compounds with an inhibitory influence on this process are therefore of prime interest. Momordica charantia (bitter melon) is widely consumed as a vegetable and especially as a folk medicine in Asia. Here, we investigated the anti-invasive effects of bitter melon leaf extract (BMLE) on a rat prostate cancer cell line (PLS10) in vitro and in vivo. The results indicated that non-toxic concentrations of BMLE significantly inhibited the migration and invasion of cells in vitro. The results of zymography showed that BMLE inhibited the secretion of MMP-2, MMP-9 and urokinase plasminogen activator (uPA) from PLS10. Real-time RT-PCR revealed that BMLE not only significantly decreased gene expression of MMP-2 and MMP-9, but also markedly increased the mRNA level of TIMP-2, known to have inhibitory effects on the activity of MMP-2. An EnzChek gelatinase/collagenase assay showed that collagenase type IV activity was partially inhibited by BMLE. In the in vivo study, intravenous inoculation of PLS10 to nude mice resulted in a 100% survival rate in the mice given a BMLE-diet as compared with 80% in the controls. The incidence of lung metastasis did not show any difference, but the percentage lung area occupied by metastatic lesions was slightly decreased in the 0.1% BMLE treatment group and significantly decreased with 1% BMLE treatment as compared with the control. Thus, the results indicate for the first time an anti-metastatic effect of BMLE both in vitro and in vivo.

Levels of Circulating TIMP-2 and MMP2-TIMP2 Complex Are Decreased in Squamous Cervical Carcinoma

Background. The role of matrix metalloproteinase-2 and -9 (MMP-2, MMP-9) in matrix degradation and metastasis has been described in various tumors. Their action is inhibited by their natural tissue inhibitor molecules TIMP-1 and -2. Methods. The study population consisted of 12 squamous cervical carcinoma patients and 27 healthy volunteer control patients. MMP-9, MMP-2-TIMP-2 complex, TIMP-1, and TIMP-2 were analyzed from serum samples using enzyme-linked immunoassay (ELISA). Results. The mean levels of serum TIMP-2 and of MMP-2-TIMP-2 complex were higher in healthy controls compared to patients with a malignant tumor. Serum TIMP-2 values decreased significantly from healthy controls (median 323 mug/l, range 305-342 mug/l) to malignant (median 136 mug/l, range 120-151 mug/l) squamous cervical carcinoma patients (P < .000). Also, serum proMMP2-TIMP2 complex values decreased from control patients to squamous cervical carcinoma patients (P < .006). Conclusion. This paper shows that the levels of circulating TIMP-2 and that of MMP-2-TIMP-2 complex are lower in squamous cervical carcinoma patients than in healthy women.

The anatomy and physiology of the suspensory apparatus of the distal phalanx

The equine hoof capsule protects the softer, more sensitive, structures within. Failure of the connection between hoof and bone (suspensory apparatus of the distal phalanx or SADP) results in the crippling lameness of laminitis. Active basal cell proliferation occurs principally in tubular hoof and proximal and distal lamellae. The remaining lamellae are virtually non-proliferative and the hoof wall moves past the stationary distal phalanx, by controlled activation and inhibition of constituent proteases. The lamellar corium derives most of its blood supply from the branches of the terminal arch which perforate the distal phalanx. Valveless veins within the foot can be exploited clinically for retrograde venous therapy or contrast radiography (venography). The basement membrane (BM) forms the interface between the lamellar epidermis and the adjacent dermis and the plasma membrane of each lamellar basal cell is attached to the BM by numerous electron dense adhesion plaques or hemidesmosomes the ultimate attachment unit of the SADP. Laminitis destroys and dislocates the BM and its components and without an intact, functional BM, the structure and function of the lamellar epidermis is pathologically compromised. Transcription and activation of constituent proteases occurs in normal hoof lamellae but in increased amounts during laminitis.

PRL1 promotes cell migration and invasion by increasing MMP2 and MMP9 expression through Src and ERK1/2 pathways

The PRL (phosphatase of regenerating liver) phosphatases represent a distinct class of protein tyrosine phosphatases, which are implicated in tumorigenesis and metastasis processes. Accumulating evidence indicates that alteration of PRL1 expression affects cell motility and tumor metastasis, although the biochemical pathways regulated by PRL1 remain less well defined. We find that elevated expression of PRL1 increases the levels of the matrix metalloproteinases MMP2 and MMP9. We have studied whether MMP2 and MMP9 are regulated by PRL1 and participate in PRL1-dependent cell migration and invasion. To this end, knockdown or inhibition of MMP2 and MMP9 by either siRNA or a specific small molecule inhibitor blocks PRL1-mediated cell migration and invasion. In addition, we report that upregulation of PRL1 activates the Src kinase through increased Tyr416 phosphorylation, which culminates in the phosphorylation of focal adhesion proteins FAK and p130(Cas), as well as ERK1/2 activation. We provide evidence that both the Src and ERK1/2 pathways contribute to the increased motility of the PRL1 cells. We further demonstrate that Src and ERK1/2 activities are required for the PRL1-induced increase in the levels of MMP2 and MMP9, likely through activation of transcription factors AP1 and Sp1. Accordingly, increased PRL1 expression results in activation of Src and ERK1/2, which stimulates MMP2 and MMP9 production, leading to increased cell migration and invasion.

Endometriotic epithelial cells induce MMPs expression in endometrial stromal cells via an NFkappaB-dependent pathway

OBJECTIVE

To explore the stroma-epithelium interactions in endometriosis and to identify the possible signalling pathways involved in this cross-talk.

DESIGN

Laboratory study via primary cultured endometrial stromal and epithelial cells.

SETTING

University Hospital.

PATIENTS

Fifteen patients with endometriosis confirmed by histopathology were recruited in the study, and 12 women free of endometriosis were used as control group.

INTERVENTION(S)

Specific NFkappaB inhibitor 1-Pyrrolidinecarbodithioic acid ammonium salt (PDTC) was used in cell cultures.

MAIN OUTCOME MEASURE(S)

The expression and secretion of MMP-2, MMP-9, TIMP-1, TIMP-2 and the DNA-binding activity of NFkappaB in normal endometrial stromal cells or in co-cultures with normal or endometriotic epithelial cells from patients with endometriosis.

RESULT(S)

Endometrial epithelial cells induced MMP-9 and MMP-2 expression in normal stromal cells in vitro. In co-cultures with endometriotic epithelial cells, normal endometrial stromal cells expressed and secreted higher MMP-2 (p < 0.05) and MMP-9 (p < 0.05). Specific inhibition of NFkappaB pathway in stromal cells abolished this induction effect by epithelial cells.

CONCLUSION(S)

Endometriotic epithelial cells induce MMPs expression and secretion in normal endometrial stromal cells via an NFkappaB-dependent pathway in vitro. This cross-talk between epithelial cells and stromal cells may facilitate the implantation and extension of the ectopic foci and favour the development of the disease.

Equine laminitis: increased transcription of matrix metalloproteinase-2 (MMP-2) occurs during the developmental phase

REASONS FOR PERFORMING STUDY

The dysadhesion and destruction of lamellar basement membrane of laminitis may be due to increased lamellar metalloproteinase activity. Characterising lamellar metalloproteinase-2 (MMP-2) and locating it in lamellar tissues may help determine if laminitis pathology is associated with increased MMP-2 transcription.

OBJECTIVES

To clone and sequence the cDNA encoding lamellar MMP-2, develop antibody and in situ hybridisation probes to locate lamellar MMP-2 and quantitate MMP-2 transcription in normal and laminitis tissue.

METHODS

Total RNA was isolated, fragmented by RT-PCR, cloned into vector and sequenced. Rabbit anti-equine MMP-2 and labelled MMP-2 riboprobe were developed to analyse and quantitate MMP-2 expression.

RESULTS

Western immunoblotting with anti-MMP-2 detected 72 kDa MMP-2 in hoof tissue homogenates and cross-reacted with human MMP-2. Immunohistochemistry and in situ hybridisation detected MMP-2 in the cytoplasm of basal and parabasal cells in close proximity to the lamellar basement membrane. Northern analysis and quantitative real-time PCR showed MMP-2 expression significantly (P < 0.01) elevated in laminitis affected tissues.

CONCLUSION

The lamellar pathology of laminitis is associated with increased transcription of MMP-2.

POTENTIAL RELEVANCE

Real-time PCR analysis of lamellar MMP-2 accurately monitors laminitis development at the molecular level and can be used diagnostically and for testing preventive strategies. Controlling increased MMP-2 transcription may ameliorate or prevent laminitis in high risk clinical situations. Our findings represent a warning to clinicians that the basement membrane lesion of laminitis is insidious and well under way before clinical signs are apparent.

The influence of opioids on urokinase plasminogen activator on protein and mRNA level in MCF-7 breast cancer cell line

Urokinase plasminogen activator plays a key role in tumor-associated processes, increasing cancer cell invasion and metastasis, and is therefore used as a marker in cancer prognosis. In this study, we have determined the effect of mu-opioid receptor agonists and antagonists on the urokinase plasminogen activator secretion in MCF-7 cell line. It was shown that mu-opioid receptor agonists, such as morphine and endomorphins, greatly stimulate urokinase plasminogen activator secretion, while naloxone and MOR-selective antagonists elicit the opposite effect. The same tendency was observed also on the urokinase plasminogen activator mRNA level. However, neither agonists nor antagonists had any effect on proliferation of MCF-7 cells. The findings reported in this study may be useful in designing further experiments aimed at elucidating the role of the opioid system in cancer cells.

Tamoxifen inhibits tumor cell invasion and metastasis in mouse melanoma through suppression of PKC/MEK/ERK and PKC/PI3K/Akt pathways

In melanoma, several signaling pathways are constitutively activated. Among these, the protein kinase C (PKC) signaling pathways are activated through multiple signal transduction molecules and appear to play major roles in melanoma progression. Recently, it has been reported that tamoxifen, an anti-estrogen reagent, inhibits PKC signaling in estrogen-negative and estrogen-independent cancer cell lines. Thus, we investigated whether tamoxifen inhibited tumor cell invasion and metastasis in mouse melanoma cell line B16BL6. Tamoxifen significantly inhibited lung metastasis, cell migration, and invasion at concentrations that did not show anti-proliferative effects on B16BL6 cells. Tamoxifen also inhibited the mRNA expressions and protein activities of matrix metalloproteinases (MMPs). Furthermore, tamoxifen suppressed phosphorylated extracellular signal-regulated kinase 1/2 (ERK1/2) and Akt through the inhibition of PKCalpha and PKCdelta phosphorylation. However, other signal transduction factor, such as p38 mitogen-activated protein kinase (p38MAPK) was unaffected. The results indicate that tamoxifen suppresses the PKC/mitogen-activated protein kinase kinase (MEK)/ERK and PKC/phosphatidylinositol-3 kinase (PI3K)/Akt pathways, thereby inhibiting B16BL6 cell migration, invasion, and metastasis. Moreover, tamoxifen markedly inhibited not only developing but also clinically evident metastasis. These findings suggest that tamoxifen has potential clinical applications for the treatment of tumor cell metastasis.

Tetrahydrocurcumin inhibits HT1080 cell migration and invasion via downregulation of MMPs and uPA

AIM

Tetrahydrocurcumin (THC) is an active metabolite of curcumin. It has been reported to have similar pharmacological activity to curcumin. The proteases that participate in extracellular matrix (ECM) degradation are involved in cancer cell metastasis. The present study investigates the effect of an ultimate metabolite of curcumin, THC, on the invasion and motility of highly-metastatic HT1080 human fibrosarcoma cells.

METHODS

The effect of THC on HT1080 cell invasion and migration was determined using Boyden chamber assay. Cell-adhesion assay was used for examining the binding of cells to ECM molecules. Zymography assay was used to analyze the effect of THC on matrix metalloproteinase (MMP)-2, MMP-9, and urokinase plasminogen activator (uPA) secretion from HT1080 cells. Tissue inhibitor of metalloproteinase (TIMP)-2 and membrane-type 1 matrix metalloproteinase (MT1-MMP) proteins levels were analyzed by Western blotting.

RESULTS

Treatment with THC reduced HT1080 cell invasion and migration in a dose-dependent manner. THC also decreased the cell adhesion to Matrigel and laminin-coated plates. Analysis by zymography demonstrated that treatment with THC reduced the levels of MMP-2, MMP-9, and uPA. THC also inhibited the levels of MT1-MMP and TIMP-2 proteins detected by Western blot analysis.

CONCLUSION

Our findings revealed that THC reduced HT1080 cell invasion and migration. The inhibition of cancer cell invasion is associated with the downregulation of ECM degradation enzymes and the inhibition of cell adhesion to ECM proteins.

Curcumin, demethoxycurcumin and bisdemethoxycurcumin differentially inhibit cancer cell invasion through the down-regulation of MMPs and uPA

Curcumin (Cur), a component of turmeric (Curcuma longa), has been reported to exhibit antimetastatic activities, but the mechanisms remain unclear. Other curcuminoids present in turmeric, demethoxycurcumin (DMC) and bisdemethoxycurcumin (BDMC) have not been investigated whether they exhibit antimetastatic activity to the same extent as curcumin. The regulation of matrix metalloproteinases (MMPs) and urokinase plasminogen activator (uPA) play important role in cancer cell invasion by cleavage of extracellular matrix (ECM). In this line, we comparatively examined the influence of Cur, DMC and BDMC on the expressions of uPA, MMP-2, MMP-9, membrane Type 1 MMP (MT1-MMP), tissue inhibitor of metalloproteinases (TIMP-2), and in vitro invasiveness of human fibrosarcoma cells. The results indicate that the differential potency for inhibition of cancer cell invasion was BDMC> or =DMC>Cur, whereas the cell migration was not affected. Zymography analysis exhibited that curcumin, DMC and BDMC significantly decreased uPA, active-MMP-2 and MMP-9 but not pro-MMP-2 secretion from the cells in a dose-dependent manner, in which BDMC and DMC show higher potency than curcumin. The suppression of active MMP-2 level correlated with inhibition of MT1-MMP and TIMP-2 protein levels involved in pro-MMP-2 activation. Importantly, BDMC and DMC at 10 microM reduced MT1-MMP and TIMP-2 protein expression, but curcumin slightly reduced only MT1-MMP but not TIMP-2. In addition, three forms of curcuminoids significantly inhibited collagenase, MMP-2, and MMP-9 but not uPA activity. In summary, these data demonstrated that DMC and BDMC show higher antimetastasis potency than curcumin by the differentially down-regulation of ECM degradation enzymes.

Adenovirus-mediated transfer of siRNA against MMP-2 mRNA results in impaired invasion and tumor-induced angiogenesis, induces apoptosis in vitro and inhibits tumor growth in vivo in glioblastoma

Invasive tumors, including gliomas, utilize proteinases to degrade extracellular matrix components and diffuse into the adjacent tissues or migrate toward distant ones. In addition, proteinase activity is required for the formation of new blood vessels within the tumor. Levels of the proteinase matrix metalloproteinase-2 (MMP-2) are highly increased in gliomas. In this study, we examined the effect of the downregulation of MMP-2 via adenovirus-mediated siRNA in gliomas. Here, we show that siRNA delivery significantly decreased levels of MMP-2 in the glioblastoma cell lines U-87 and U-251. U-87 and U-251 cells showed impaired invasion through matrigel as well as decreased migration from tumor spheroids transfected with adenoviral vector expressing siRNA against MMP-2. Additionally, tumor-induced angiogenesis was decreased in in vitro experiments in cultured human microvascular endothelial cells (HMECs) in serum-free conditioned medium of glioblastoma cells transfected with these constructs and co-cultures of glioma cells with HMECs. We also observed decreased angiogenesis in the in vivo dorsal skin-fold chamber model. Moreover, MMP-2 inhibition induced apoptotic cell death in vitro, and suppressed tumor growth of preestablished U-251 intracranial xenografts in nude mice. Thus, specific targeting of MMP-2 may provide a novel, efficient approach for the treatment of gliomas and improve the poor outcomes of patients with these brain tumors.

Arsenic enhances matrix metalloproteinase-14 expression in fibroblasts

This study focused on the effects of arsenic (As) on fibroblast-derived matrix metalloproteinase (MMP)-2 and -14 levels, as these proteins were reported to be associated with tumor progression. Arsenic was found to promote production of the fibroblast-derived active form of MMP-2. Further, As at 100 or 1000 microM increased MMP-14 expression levels in fibroblasts. In addition, 1000 microM mercury (Hg) but not As increased pro-MMP-2 protein, which is involved in the conversion of the proenzyme into its active form. Since MMP-14 is an activator of pro-MMP-2, data suggest that As promotes production of fibroblast-derived active form of MMP-2 through increased expression of MMP-14. Evidence indicates that As appeared to be less effective than Hg in the conversion of pro-MMP-2 into its active form.

Chronic hypoxia promotes an aggressive phenotype in rat prostate cancer cells

In general, tumors cells that are resistant to apoptosis and increase angiogenesis are a result of the hypoxic responses contributing to the malignant phenotype. In this study, we developed a chronic hypoxic cell model (HMLL), by incubating the prostate cancer MatLyLu cells in a hypoxic chamber (1% O(2)) over 3 weeks. Surviving cells were selected through each cell passage and were grown in the hypoxic condition up to 8 weeks. This strategy resulted in survival of only 5% of the cells. The surviving hypoxic cells displayed a greater stimulation on hypoxic adaptive response, including a greater expression of glucose transporter1 (Glut1) and VEGF secretion. In addition, higher invasion activity was observed in the chronic hypoxic HMLL cells as compared to MatLyLu cells exposed to acute hypoxia (1% O(2), 5 h) using the matrigel assay. To further examine the role of HIF-1alpha in tumor progression, both MatLyLu and HMLL cells were transfected with dominant-negative form of HIF-1alpha (DNHIF-1alpha). The Matrigel invasion activity induced by chronic hypoxia was significantly attenuated by DNHIF-1alpha. These results suggest that signaling pathways leading to hypoxic response may be differentially regulated in chronic hypoxic cells and acute hypoxic cells. Chronic hypoxia may play a greater role than acute hypoxia in promoting the aggressive phenotype of tumor cells. This observation mimics the clinical scenario where tumor cells following treatment with radiation are subjected to hypoxic conditions. The reemergence of tumor following treatment usually results in tumor cells that are more aggressive and metastatic.

Matrix metalloproteinase-9 activity is associated with poor prognosis in T3-T4 node-negative colorectal cancer

Reversion-inducing cysteine-rich protein with Kazal motifs (RECK) is a novel membrane-anchored matrix metalloproteinase (MMP) inhibitor. RECK, MMP-2, and MMP-9 are believed to play crucial roles in tumor progression. This study was designed to examine the prognostic value of RECK, MMP-2, and MMP-9 in conjunction with other clinicopathologic factors in patients of T3-T4 node-negative colorectal cancer. RECK and MMP expression was observed using immunohistochemical analysis of the primary tumor from 89 patients with curatively resected T3-4 N0 colorectal cancer retrospectively. High RECK expression was observed in 51 cases, whereas expression was low in the other 38 cases. MMP-2 and MMP-9 expression was positive in cancer cells in 24 and 33 cases, respectively. RECK and MMP-2 expression was not significantly associated with any clinicopathologic factors. However, expression of MMP-9 was correlated with tumor location. A statistically significant inverse correlation was found between RECK and MMP-2 expression, and a statistically significant correlation was found between MMP-2 and MMP-9 expression. However, no association between RECK and MMP-9 expression was observed. Univariate analysis demonstrated that rectal tumor location, preoperative carcinoembryonic antigen more than 5 ng/mL, positive lymphatic invasion, less than 12 dissected lymph nodes, and positive MMP-9 expression were poor prognostic factors of disease-free survival. A multivariate analysis confirmed that enhanced MMP-9 expression was an independent and significant factor for prediction of a poor prognosis. In addition, positive lymphatic invasion and less than 12 dissected lymph nodes were significant negative prognostic factors. In conclusion, MMP-9 status represents a novel prognostic factor in evaluation of T3-T4 node-negative colorectal cancer.

Matrix metalloproteinase localisation by in situ-RT-PCR in archival human breast biopsy material

Utilising archival human breast cancer biopsy material we examined the stromal/epithelial interactions of several matrix metalloproteinases (MMPs) using in situ-RT-PCR (IS-RT-PCR). In breast cancer, the stromal/epithelial interactions that occur, and the site of production of these proteases, are central to understanding their role in invasive and metastatic processes. We examined MT1-MMP (MMP-14, membrane type-1-MMP), MMP-1 (interstitial collagenase) and MMP-3 (stromelysin-1) for their localisation profile in progressive breast cancer biopsy material (poorly differentiated invasive breast carcinoma (PDIBC), invasive breast carcinomas (IBC) and lymph node metastases (LNM)). Expression of MT1-MMP, MMP-1 and MMP-3 was observed in both the tumour epithelial and surrounding stromal cells in most tissue sections examined. MT1-MMP expression was predominantly localised to the tumour component in the pre-invasive lesions. MMP-1 gene expression was relatively well distributed between both tissue compartments, while MMP-3 demonstrated highest expression levels in the stromal tissue surrounding the epithelial tumour cells. The results demonstrate the ability to distinguish compartmental gene expression profiles using IS-RT-PCR. Further, we suggest a role for MT1-MMP in early tumour progression, expression of MMP-1 during metastasis and focal expression pattern of MMP-3 in areas of expansion. These expression profiles may provide markers for early breast cancer diagnoses and present potential therapeutic targets.

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.

Matrix metalloproteases: underutilized targets for drug delivery

Pathophysiological molecules in the extracellular environment offer excellent targets that can be exploited for designing drug targeting systems. Matrix metalloproteases (MMPs) are a family of extracellular proteolytic enzymes that are characterized by their overexpression or overactivity in several pathologies. Over the last two decades, the MMP literature reveals heightened interest in the research involving MMP biology, pathology and targeting. This review describes various strategies that have been designed to utilize MMPs for targeting therapeutic entities. Key factors that need to be considered in the successful design of such systems have been identified based on the analyses of these strategies. Development of targeted drug delivery using MMPs has been steadily pursued; however, drug delivery efforts using these targets need to be intensified and focused to realize the clinical application of the fast developing fundamental MMP research.