The role of matrix metalloproteinases in tumor angiogenesis and tumor metastasis

Aminopeptidase N (APN/CD13) is selectively expressed in vascular endothelial cells and plays multiple roles in angiogenesis

Proteolytic enzyme-mediated degradation of the extracellular matrix (ECM) is crucial for the formation of both tumor metastasis and angiogenesis. Recently, several reports have suggested that aminopeptidases are involved in this process, but precisely how is largely unknown. We found here that aminopeptidase N (APN/CD13) was selectively expressed in vascular endothelial cells including human umbilical vein endothelial cells (HUVEC) and human aortic endothelial cells (HAEC), and was not detectable in a majority of normal cells and tumor cell lines we examined. RNA interference (RNAi) of APN resulted in the inhibition of capillary tube formation of HUVEC on Matrigel. APN siRNA suppressed the migration of HUVEC through a fibronectin-coated Transwell membrane, and reduced the cellular adhesion to Matrigel and various adhesion molecules including type IV collagen, type I collagen and fibronectin. These findings suggest that APN is a multifunctional protein with important roles in vascular endothelial morphogenesis during angiogenesis.

A phase III randomized trial of BAY 12-9566 (tanomastat) as maintenance therapy in patients with advanced ovarian cancer responsive to primary surgery and paclitaxel/platinum containing chemotherapy: a National Cancer Institute of Canada Clinical Trials Group Study

OBJECTIVE

BAY 12-9566 (tanomastat) is a biphenyl matrix metalloprotease inhibitor (MMPI) with antiangiogenic and antimetastatic properties in vivo. The objective of the study was to determine whether the addition of BAY 12-9566 after optimal response to chemotherapy could improve time to progression (TTP).

PATIENTS AND METHODS

Patients enrolled in the study had received 6-9 cycles of platinum/paclitaxel containing chemotherapy for stage III or IV ovarian carcinoma, with a response of no evidence of disease, or complete or partial response with residual disease < 2 cm. Patients were then randomized to BAY 12-9566 800 mg p.o. b.i.d. or placebo. The primary endpoint was progression-free survival (PFS); secondary endpoints were quality of life, toxicity, changes in CA 125 levels, response, and overall survival (OS). The total planned sample size was 730.

RESULTS

The study was closed after 243 patients had been randomized because of Bayer's decision to close all ongoing trials due to negative results from other phase III trials in pancreatic and small cell lung cancer. The final analysis was performed in August 2000 after the requisite number of events for the first planned interim analysis had occurred; 54% of patients had progressed and 18% had died.

PATIENT CHARACTERISTICS

performance status was ECOG 0/1/2 in 65/33/2%; median age 57 years; 79% of patients were FIGO stage III; 41% were optimally debulked; 76% had serous histology, and 67% had > or = grade 3 histology. Toxicity was generally grade 1 or 2 in severity, with the most common (BAY 12-9566 vs. placebo) being nausea (26% vs. 13%), fatigue (24% vs. 12%), diarrhea (14% vs. 10%), rash (12% vs. 7%), grade 3/4 thrombocytopenia (3% vs. 1%), and grade 3/4 anemia (5% vs. 1%). Median time to progression (TTP) was 10.4 months (8.5-11.5) for BAY 12-9566 and 9.2 months (7.2-13.9) for placebo (P = 0.67). Median overall survival (OS) was 13.9 months (12.9-infinity) for BAY 12-9566 and 11.9 months (10.5-16.5) for placebo (P = 0.53).

CONCLUSION

We conclude that BAY 12-9566 was generally well tolerated and at the time of the final analysis, there was no evidence of an impact of BAY 12-9566 on PFS or OS.

Matrix metalloproteinase inhibitor RECK expression in canine tumors

Matrix metalloproteinases (MMPs) selectively degrade the extracellular matrix, and they have been reported to play an important role in tumor invasion, metastasis and angiogenesis. These enzymes are closely related to tumor malignancy and patient survival time. Recently, reversion-inducing cysteine-rich protein with Kazal motifs (RECK) gene was identified as an endogenous membrane-anchored MMP inhibitor. The down-regulation of RECK has been implicated in tumor progression. In this study, the expression levels of the RECK messenger ribonucleic acid (mRNA) in various spontaneously developed canine tumors were investigated by using quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), and the correlation between RECK and clinicopathological factors, as well as MMP-9 expression were analyzed. The median age of 36 dogs investigated in this study was 9 years old (range, 1-15 years old). Quantitative RT-PCR could detect low levels of expression of RECK mRNA in the tumor samples. The expression levels of RECK mRNA in some tumor tissue samples were significantly lower than those in normal tissue samples. No significant associations of RECK with clinicopathological factors were observed. Using the Mann-Whitney U test, the expression level of the MMP-9 mRNA was observed to be significantly correlated to RECK expression (p<0.05).

The effects of curcumin on the invasiveness of prostate cancer in vitro and in vivo

Curcumin has become a focus of interest with regard to its antitumor effects in prostate cancer; however, the effects of this agent on invasion and metastasis remain less well understood. Matrix metalloproteinases (MMPs) are important prerequisite for tumor invasion and metastasis. In this study, we evaluated the effects of curcumin on prostate cancer cells (DU-145) invasion in both in vitro and in vivo. We utilized zymography and ELISA in order to determine the MMP-2 and MMP-9 activity. Matrigel invasion assay was performed to assess cellular invasion. We developed a xenograft model to examine tumorigenicity. Curcumin treatment resulted not only in a significant reduction in the expression of MMP-2 and MMP-9, but also effected the inhibition of invasive ability in vitro. Curcumin was shown to induce a marked reduction of tumor volume, MMP-2, and MMP-9 activity in the tumor-bearing site. The metastatic nodules in vivo were significantly fewer in the curcumin-treated group than untreated group. Curcumin appears to constitute a potential agent for the prevention of cancer progression, or at least of the initial phase of metastasis, in prostate cancer.

Role of lysosomal cathepsins in naphthazarin- and Fas-induced apoptosis in oral squamous cell carcinoma cells

CONCLUSION

Intracellular cysteine cathepsins are pro-apoptotic factors involved in activation of caspases in two oral squamous cell carcinoma (SCC) cell lines.

OBJECTIVE

To study the possible involvement of lysosomal cathepsins in oral SCC cell apoptosis.

MATERIAL AND METHODS

Apoptosis was induced in the two human oral SCC cell lines UT-SCC-20A and UT-SCC-24A using naphthazarin or anti-Fas antibodies, and was studied by analysis of caspase activity and nuclear morphology. Involvement of lysosomal cathepsins was investigated using the cysteine cathepsin inhibitor z-FA-FMK and the cathepsin D inhibitor pepstatin A. The amounts of cellular and soluble Fas death receptor were determined by ELISA.

RESULTS

Release of cathepsins from the lysosomes to the cytosol was observed early in apoptosis. Cysteine cathepsins were found to be involved in activation of caspases in response to treatment with naphthazarin or anti-Fas antibodies, but inhibition of cysteine cathepsin activity was not sufficient to prevent cell death. Moreover, inhibition of cysteine cathepsin activity resulted in increased expression of the Fas death receptor, suggesting involvement of extracellular cysteine cathepsins in death receptor shedding.

The Proangiogenic Capacity of Polymorphonuclear Neutrophils Delineated by Microarray Technique and by Measurement of Neovascularization in Wounded Skin of CD18-Deficient Mice

Growing evidence supports the concept that polymorphonuclear neutrophils (PMN) are critically involved in inflammation-mediated angiogenesis which is important for wound healing and repair. We employed an oligonucleotide microarray technique to gain further insight into the molecular mechanisms underlying the proangiogenic potential of human PMN. In addition to 18 known angiogenesis-relevant genes, we detected the expression of 10 novel genes, namely midkine, erb-B2, ets-1, transforming growth factor receptor-beta2 and -beta3, thrombospondin, tissue inhibitor of metalloproteinase 2, ephrin A2, ephrin B2 and restin in human PMN freshly isolated from the circulation. Gene expression was confirmed by the RT-PCR technique. In vivo evidence for the role of PMN in neovascularization was provided by studying neovascularization in a skin model of wound healing using CD18-deficient mice which lack PMN infiltration to sites of lesion. In CD18-deficient animals, neovascularization was found to be significantly compromised when compared with wild-type control animals which showed profound neovascularization within the granulation tissue during the wound healing process. Thus, PMN infiltration seems to facilitate inflammation-mediated angiogenesis which may be a consequence of the broad spectrum of proangiogenic factors expressed by these cells.

Low-density lipoprotein receptor-related protein contributes to the antiangiogenic activity of thrombospondin-2 in a murine glioma model

Host antiangiogenesis factors defend against tumor growth. The matricellular protein, thrombospondin-2 (TSP-2), has been shown to act as an antiangiogenesis factor in a carcinogen-induced model of skin cancer. Here, using an in vivo malignant glioma model in which the characteristics of the tumors formed after intracerebral implantation of GL261 mouse glioma cells are assessed, we found that tumor growth and microvessel density were significantly enhanced in tumors propagated in TSP-2(-/-) mice. Mechanistically, matrix metalloproteinase (MMP)-2 has been associated with neoangiogenesis and it has been proposed that the levels of available MMP-2 may be down-regulated by formation of a complex with TSP-2 that is internalized by low-density lipoprotein receptor-related protein 1 (LRP1). We found elevated expression of MMP-2 and MMP-9 in tumors propagated in TSP-2(-/-) mice, with a preferential localization in the microvasculature. In wild-type mice, MMP-2 was coexpressed with TSP-2 in the tumor microvasculature. In vitro, addition of recombinant (rec) TSP-2 to mouse brain microvessel endothelial cells reduced MMP-2 levels and invasion through mechanisms that could be inhibited by a competitive inhibitor of ligand binding to LRP1 or by siLRP1. Thus, the antiangiogenic activity of TSP-2 is capable of inhibiting the growth of gliomas in part by reducing the levels of MMP-2 in the tumor microvasculature. This mechanism is mediated by LRP1.

Jaw bone necrosis without previous dental extractions associated with the use of bisphosphonates (pamidronate and zoledronate): a four-case report

Jaw bone necrosis is a clinical condition associated with defects in vascularization of the maxilla or the mandibular bone, usually present following head and neck radiotherapy and/or oral surgical interventions. Bisphosphonates are synthetic analogues of pyrophosphate used in the treatment of patients with hypercalcemia as a result of malignancy, bone metastasis and for the treatment of other disorders such as metabolic bone diseases, Paget's disease and osteoporosis. Over last 10 years, cases of jaw bone necrosis have been associated with the use of bisphosphonate therapy. In particular, Ruggiero et al. (J Oral Maxillofac Surg 2004; 62: 527-534) in 2004 described a large group of patients (63) with jaw bone necrosis probably related to the use of these drugs. It should be noted that all the patients in the group described either underwent head and neck radiotherapy or had a dental extraction while taking bisphosphonates. In the present study, we reported four cases of jawbone necrosis in patients taking pamidronate (Aredia) and zoledronate (Zometa) without having undergone any kind of radiotherapy or dental surgery. All the patients were females between the ages of 56 and 71 years; three were treated with bisphosphonates for bone metastasis and one for multiple myeloma. All the patients received surgical treatment with bone curettage, with partial and/or temporary improvement of the lesions. Although a treatment for bisphosphonate-induced bone lesions has not yet been established, we suggest careful evaluation of the patients' oral health before prescribing bisphosphonate treatment.

Stress and depression-induced immune dysfunction: implications for the development and progression of cancer

The persistent activation of the hypothalamic-pituitary-adrenal axis and the sympathetic-adrenal-medullary axes in chronic stress response and in depression impairs the immune response and contributes to the development and progression of some types of cancer. This overview presents results from experimental animal models, human studies, and clinical evidence that various cellular and molecular immunological parameters are compromised in chronic stress and depression. At the cellular level, stressed and depressed patients had overall leukocytosis, high concentrations of circulating neutrophils, reduced mitogen-stimulated lymphocyte proliferation and neutrophil phagocytosis. At the molecular level, high levels of serum basal cortisol, acute phase proteins, specific antibodies against herpes simplex virus type 1 and Epstein Barr virus, plasma concentration of interleukins IL-1, IL-6, and TNF-alpha, and a shift in the balance of Th1 and Th2 immune response were observed. Both stress and depression were associated with the decreased cytotoxic T-cell and natural killer cell activities affecting the processes of the immune surveillance of tumours, and the events that modulate the development and the accumulation of somatic mutations and genomic instability. DNA damage, growth and angiogenic factors, proteases, matrix metalloproteinases, and reactive oxygen species were also related to the chronic stress response and depression. Behavioural strategies, psychological, and psychopharmacotherapeutic interventions that enhance effective coping and reduce affective distress showed beneficial effects in cancer patients. A better understanding of the bidirectional communication between the neuroendocrine and immune systems could contribute to novel clinical and treatment strategies in oncology.

Clinicopathologic and Prognostic Significance of MMP-7 (Matrilysin) Expression in Human Rectal Cancer

OBJECTIVE

There is increasing evidence to indicate that MMP-7 plays a more important role in tumor progression than other MMPs. The aim of this study was to detect MMP-7 expression in human rectal cancer and normal rectal tissue and to determine whether it is correlated with invasion and metastasis of human rectal cancer.

METHODS

Eighty-six paired samples of rectal cancer and distant normal rectal tissue obtained from 100 inpatients were allocated into two groups (cancer group and control group). MMP-7 mRNA was detected by relative quantitative real-time RT-PCR and MMP-7 protein was examined by immunohistochemical staining and computerized image analysis.

RESULTS

MMP-7 mRNA expression in cancer group was higher than that in control group (P = 0.006), the expression ratios of 31 samples (37.35%) were <1 and 52 (62.65%) were >1. The mRNA expression level was correlated with Dukes Staging, histological differentiation grade and CEA level. The MMP-7 protein expression was in accordance with mRNA expression level. The positive degree of immunohistochemical staining in cancer group (1.82 +/- 0.03) was different from that in control group (1.17 +/- 0.13, P = 0.002). Moreover, in cancer group the positive staining degree in high-level mRNA cancers (2.04 +/- 0.18, n = 52) was higher than that in low-level mRNA ones (1.58 +/- 0.23, n = 31, P = 0.008).

CONCLUSIONS

Our results suggest that MMP-7 plays an important role in the progression of human rectal cancer. MMP-7 may be selected as a clinical diagnosis and prognosis index in rectal cancer.

Inhibition of human leukemia xenograft in nude mice by adenovirus-mediated tissue inhibitor of metalloproteinase-3

Considerable studies have demonstrated the pivotal roles of matrix metalloproteinases (MMPs) in leukemia dissemination and extramedullary infiltration. Tissue inhibitors of matrix metalloproteinases (TIMPs) are multifunctional proteins with MMPs inhibitory effects. However, little is known about the application of TIMPs in the treatment of leukemia. Here, we investigated the effects of TIMP-3 overexpression via adenoviral gene delivery on the in vitro growth and invasiveness of leukemic cells and the in vivo progress of K562-derived xenografts in nude mice. The in vitro invasiveness of K562 cells was markedly impaired by AdTIMP-3 infection. Moreover, TIMP-3 significantly inhibited K562-derived angiogenic factors-induced proliferation, migration and bFGF-induced tube formation of endothelial cells (ECs) in vitro, and reduced VEGF-induced gelatinases expression and activation in ECs. Although TIMP-3 overexpression had no direct effect on the growth of K562 cells in vitro, repeated intratumoral injection of AdTIMP-3 significantly inhibited the growth of K562 xenografts in nude mice. Furthermore, lower microvessel density, less vessel maturity and increased apoptosis were observed in AdTIMP-3-treated K562 xenografts, suggesting the importance of antiangiogenic action of TIMP-3. These data demonstrated the potential of applying AdTIMP-3 as an effective antiangiogenic adjuvant in the treatment of leukemia progression.

Molecular pathology of non-small-cell lung cancer

The molecular basis of lung carcinogenesis must be understood more fully and exploited to enhance survival rates of patients suffering from lung cancer. In this review we will discuss the major molecular alterations that occur in lung cancer. Emphasis is placed on alterations that occur early during carcinogenesis since they might be relevant for future screening programs. Finally we will shortly review new approaches that are used to study the molecular pathology of lung cancer and how they can be applied in a clinical setting.

Age-related changes in the expression of gelatinase and tissue inhibitor of metalloproteinase genes in mandibular condylar, growth plate, and articular cartilage in rats

Mandibular condylar cartilage acts as both articular and growth plate cartilage during growth, and then becomes articular cartilage after growth is complete. Cartilaginous extracellular matrix is remodeled continuously via a combination of production, degradation by matrix metalloproteinases (MMPs), and inhibition of MMP activity by tissue inhibitors of metalloproteinases (TIMPs). This study attempted to clarify the age-related changes in the mRNA expression patterns of MMP-2, MMP-9, TIMP-1, TIMP-2, and TIMP-3 in mandibular condylar cartilage in comparison to tibial growth plate and articular cartilage using an in situ hybridization method in growing and adult rats. MMP-2 and MMP-9 were expressed in a wide range of condylar cartilage cells during growth, and their expression domains became limited to mature chondrocytes in adults. The patterns of TIMP-1 and TIMP-2 expression were similar to those of MMP-2 and MMP-9 during growth, and were maintained until adulthood. TIMP-3 was localized to hypertrophic chondrocytes throughout the growth stage. Therefore, we concluded that TIMP-1 and TIMP-2 were general inhibitors of MMP-2 and MMP-9 in condylar cartilage, while TIMP-3 regulates the collagenolytic degradation of the hypertrophic cartilage matrix.

The role of the extracellular matrix in angiogenesis in malignant glioma tumors

Angiogenesis is a promising target for the development of effective strategies for the treatment of malignant brain tumors in that it has the potential to starve large tumors and prevent the regrowth of residual margins. Two critical steps in angiogenesis, the proliferation of activated endothelial cells and their migration into the perivascular space (sprouting), require adherence of the endothelial cells to the extracellular matrix (ECM). Thus, the availability of the appropriate ligands within the ECM contributes to the regulation of angiogenesis. In addition, several components of the ECM can act through other mechanisms to further promote angiogenesis or inhibit it. Current evidence suggests that the regulation of angiogenesis is a dynamic process in which the endothelial cells can promote angiogenesis by secreting proteases that remodel the ECM, tumor cells can further promote angiogenesis by secreting ECM components and actively remodeling their environment, and stromal cells may respond to angiogenesis associated with tumors and inflammatory reactions by secreting inhibitory molecules. Here, we provide a critical review of the protein and proteoglycan components of the ECM that have been implicated in angiogenesis with an emphasis on their role in promoting or inhibiting angiogenesis in brain tumors.

Thrombomodulin enhances the invasive activity of mouse mammary tumor cells

Thrombomodulin (TM) is a thrombin receptor on the surface of endothelial cells that converts thrombin from a procoagulant to an anticoagulant. Thrombin promotes invasion by various tumor cells, and positive or negative correlations are found between the expression of TM and tumorigenesis in some patients. In this study, we used an invasion assay to investigate the effect of TM on the invasive activity of a mouse mammary tumor cell line, MMT cells, and the effects of TM were compared with those of thrombin as a positive control. In the presence of 1% fetal calf serum (FCS), TM significantly stimulated MMT cell invasion in a dose-dependent manner, resulting in an approximately 3-fold increase at 1-10 pg/ml over the untreated control. Thrombin also caused a similar degree of stimulation at 50 ng/ml. Since thrombin activity was detected in the components of the assay system, an invasion assay was also performed in a thrombin-activity-depleted assay system constructed to eliminate the effect of thrombin activity; TM (10 pg/ml) plus thrombin (1 pg/ml) stimulated invasion by approximately 3.5-fold in this assay system. Hirudin, a specific thrombin inhibitor, inhibited stimulation by TM as well as by thrombin in both the presence and absence of 1% FCS. Investigations of the effects of TM on proliferation, adhesion and chemotaxis to clarify the mechanism of stimulation by TM revealed that TM does not affect proliferation or adhesion in the presence of 1% FCS, but stimulates chemotaxis by approximately 2.3-fold. Similar results were obtained in experiments using thrombin. TM (10 pg/ml) plus thrombin (1 pg/ml), on the other hand, stimulated chemotaxis by approximately 2.3-fold in the thrombin-activity-depleted assay system. Binding studies using [125I]-thrombin revealed that the cells have specific saturable binding sites for thrombin. These results show that TM stimulates the invasive activity of MMT cells, probably by acting as a cofactor for the thrombin-stimulated invasion of the cells via its receptor and lowering the effective concentration of thrombin. The findings also indicate that the stimulation of invasive activity in the presence of 1% FCS and in the thrombin-activity-depleted assay system may mainly be mediated by the stimulation of chemotaxis.

Endostatin signaling and regulation of endothelial cell-matrix interactions

The growth and survival of a malignant tumor are dependent on the formation and maintenance of its own microvasculature, a process termed angiogenesis. Inhibition of this phenomenon is an emerging strategy in cancer therapy. The extracellular matrix surrounding the vascular endothelial cells contains cryptic protein domains, which are exposed by changes in the proteolytic homeostasis of the tumor microenvironment. These fragments transmit local signals, which regulate vascular endothelial cell proliferation and migration. Endostatin, the proteolytic fragment of collagen type XVIII, is a potent inhibitor of tumor angiogenesis in various mouse models and is currently in clinical trials for therapeutic use in human cancer. Multiple cell surface receptors have been described for endostatin, but the signals transmitted by these receptors resulting in the inhibition of angiogenesis have so far been poorly characterized. Studies on the effects of endostatin on cultured endothelial cells suggest that the antimigratory and antiproliferative properties of this molecule are the major mechanisms underlying its antiangiogenic potential. These effects may be a consequence of endostatin modulation of endothelial cell-matrix interactions and pericellular proteolysis.

Serum matrix metalloproteinase-9 in head and neck squamous cell carcinoma is a prognostic marker

The aim of this study was to determine whether serum matrix metalloproteinase-9 (MMP-9) could predict cause-specific and relapse-free survival in patients with squamous cell carcinoma of head and neck. Furthermore, this study was designed to investigate whether there is an association between MMP-9 immunohistochemical staining and serum MMP-9 levels. Pretreatment serum levels of MMP-9 were quantitatively measured by ELISA assay in 67 patients presenting with a primary head and neck squamous cell carcinoma. The results were compared with the corresponding immunohistochemical staining results, clinical data and the patients' outcome. The follow-up time for all of the patients was at least 5 years. There was a statistically significant correlation between circulating MMP-9 and MMP-9 immunohistochemical staining in the corresponding tumors (p = 0.028). The cause-specific and relapse-free survival rates were clearly lower among patients with high MMP-9 serum levels (> 73 ng/ml). The 5-year cause-specific survival-rate was 40% in a patient group with high serum MMP-9, and 69% for patients with a low MMP-9 level (p = 0.027). In the same follow-up period, the cumulative relapse-free survival rate was 36% in patients presenting with a high serum MMP-9 and 66% in those with a low MMP-9 level. No correlation was found between MMP-9 serum levels and the traditional clinical or histopathologic factors. The results suggest for the first time that pretreatment serum MMP-9 level could serve as a prognostic factor in head and neck squamous cell carcinoma.

Expression of Membrane Type 1 Matrix Metalloproteinase Is Associated with Cervical Carcinoma Progression and Invasion

Membrane type 1 matrix metalloproteinase (MT1-MMP) is frequently expressed by cancer cells and is believed to play an important role in cancer cell invasion and metastasis. However, little is known about the role of MT1-MMP in mediating invasiveness of cervical cancer cells. In this study, we examined MT1-MMP expression in 58 primary human cervical tissue specimens, including normal cervix, low-grade squamous intraepithelial lesions (LSIL), high-grade SILs (HSIL), and invasive carcinomas. We also evaluated MT1-MMP, MMP-2, and tissue inhibitor of metalloproteinase-2 expression in several cervical cancer-derived cell lines, human papillomavirus (HPV)-immortalized keratinocytes, and keratinocytes derived from a LSIL. Using in situ hybridization techniques to study the cervical tissue specimens, we found that MT1-MMP expression increases with cervical tumor progression (Spearman correlation coefficient = 0.66; P < 0.0001, exact test). Specifically, MT1-MMP expression is very low or absent in normal cervix and LSILs, is readily detectable in HSILs, and is very strongly expressed in nearly all invasive carcinomas. Most but not all cervical cancer-derived cell lines also expressed significant levels of MT1-MMP and MMP-2. Constitutive expression of exogenous MT1-MMP in cervical carcinoma-derived cells and HPV-immortalized keratinocytes with low endogenous levels of MT1-MMP induced invasiveness in collagen I, but this effect was not observed in LSIL-derived keratinocytes. Our results show that MT1-MMP is a key enzyme mediating cervical cancer progression. However, MT1-MMP alone is not always sufficient for inducing keratinocyte invasiveness at least in the collagen I invasion assay used in this study. Further studies of gene expression in preinvasive and invasive cervical cancers should assist with identification of additional critical factors mediating cervical cancer progression.

Expression of tissue inhibitor of matrix metalloproteinases-1 during aging in rat liver

AIM: To investigate the expression and role of tissue inhibitor of matrix metalloproteinases-1 (TIMP-1) during natural aging in rat liver and to detect the expression of matrix metalloproteinase-2 (MMP-2) and MMP-9.

METHODS: The rats were divided into 3-mo-old group (n = 5), 10-mo-old group (n = 5) and 24-mo-old group (n = 5). Histopathologic changes of liver were observed with HE and Masson stain. The location and protein expressions of TIMP-1 were determined by immunohistochemistry and Western blot; message RNA (mRNA) levels were measured in livers from rats of various ages by semi-quantitative reverse transcriptional polymerase chain reaction (RT-PCR). In addition, the expression of MMP-2 and MMP-9 was assessed by RT-PCR and Western blot.

RESULTS: Histologic examination showed that the aging liver had excessive fatty degeneration and collagen deposition. Immunohistochemical staining showed that TIMP-1 related antigen in livers was located in cytoplasm. The protein expression of TIMP-1 was significantly higher in the oldest animals and the mRNA expression was increased significantly in the 24-mo-old rats (t = 4.61, P = 0.002<0.05, 24-vs 10-mo-old rats; t = 4.31, P = 0.003<0.05, 24- vs 3-mo-old rats). The expression of MMP-2 and MMP-9 had no change during aging; the ratios TIMP-1/MMP-2 and TIMP-1/MMP-9 in aging liver were significantly higher than those in maturation and young livers.

CONCLUSION: TIMP-1 may play an important role in the process of liver aging.

Molecular cloning of canine membrane-anchored inhibitor of matrix metalloproteinase, RECK

The reversion-inducing cysteine-rich protein with Kazal motifs (RECK) gene is one of the endogenous matrix metalloproteinase (MMP) inhibitors. It was reported that decreased RECK expression closely correlated with tumor malignancy. We determined the cDNA sequence of the canine RECK gene. The cDNA sequence and deduced amino acid of canine RECK were 2,913 bases and 971 residues, respectively. The predicted amino acid sequence of the protein showed 95.5% and 91.9% homology with human and mouse RECK, respectively. RECK mRNA expression was analyzed in various canine tissues and tumor cell lines by quantitative RT-PCR. The highest RECK expression was detected in lung and testis. In comparison with the tissues, a remarkably low expression level was detected in tumor cell lines. In addition, the RECK gene was transfected in the canine transitional cell carcinoma, and its influence on cell proliferation, migration, and invasion was analyzed. The transfected RECK gene suppressed only canine tumor invasion. These results showed that RECK might play an important role in tumor malignancy in dogs as well as in other mammalians.

Modulation of monocyte matrix metalloproteinase-2 by breast adenocarcinoma cells

Introduction

The presence of monocyte and macrophage cells in growing breast tumors, and the positive relationship between the degree of immune cell infiltration and tumor growth, suggest a possible paracrine growth regulatory function of immune cells in breast cancer.

Method

To better understand the interaction between monocytes and breast cancer cells, in vitro matrix metalloproteinase and tissue inhibitor of metalloproteinase activity was assessed from the THP-1 myeloid cell line in response to conditioned media from two breast cancer cell lines, MCF-7 and MDA-MB-231.

Results

Enzymography and immunoblotting revealed increased MMP-2 as well as increased levels of TIMP-1 and TIMP-2. Furthermore, a significant increase in the invasive potential of MCF-7 and MDA-MB-231 cells was noted in response to THP-1 cell-conditioned media.

Conclusion

These data demonstrate that monocyte cells in the breast tumor microenvironment play an important role in the modulation of MMPs, which may have a significant effect on the control of tumor growth and metastatic spread.

Comparative Analysis of the ADAM and ADAMTS Families

The "A Disintegrin And Metalloproteinase" (ADAM) protein family and the "A Disintegrin-like And Metalloproteinase with ThromboSpondin motifs" (ADAMTS) protein family are two related families of human proteins. The similarities and differences between these two families have been investigated using phylogenetic trees and homology modeling. The phylogenetic analysis indicates that the two families are well differentiated, even when only the common metalloprotease domain is taken into account. Within the ADAM family, several proteins are lacking the binding motif for the catalytic zinc in the active site and thus presumably lack any catalytic activity. These proteins tend to cluster within the ADAM phylogenetic tree and are expressed in specific tissues, suggesting a functional differentiation. The present analysis allows us to propose the following: (i) ADAMTS proteins have a conserved role in the human organism as proteases, with some differentiation in terms of substrate specificity; (ii) ADAM proteins can act as proteases and/or mediators of intermolecular interactions; (iii) proteolytically active ADAMs tend to be more ubiquitously expressed than the inactive ones.

Inhibitory effect of norcantharidin, a derivative compound from blister beetles, on tumor invasion and metastasis in CT26 colorectal adenocarcinoma cells

Norcantharidin (NCTD), a potential anti-cancer drug, is the demethylated analog of cantharidin isolated from blister beetles. The present study investigated the effect of NCTD on tumor invasion and metastasis. A cytotoxicity assay of NCTD in CT26 colorectal adenocarcinoma cells showed a dose- and time-dependent decrease in cell viability. NCTD (50 microM)-treated CT26 cells not only showed an inhibited cell invasion of 65.6%, but also decreased the activity of matrix metalloproteinase-2 and -9. NCTD decreased the adhesive ability of CT26 cells in a dose-dependent manner. At a concentration of 100 microM, NCTD showed a down-expression of several cadherin-catenin adhesion molecules, including Desmoglein, N-cadherin, and alpha- and beta-catenin, while there were no obvious changes in E-cadherin and gamma-catenin. Intraperitoneal injection of NCTD (2 mg/kg/day) in BALB/c mice reduced both the pulmonary metastatic capacity of CT26 cells and prolonged the survival day of the mice. These results demonstrated that it was effective in blocking both tumor invasion and metastasis.

Matrix metalloproteinase activity and osteoclasts in experimental prostate cancer bone metastasis tissue

Previously, we and others showed that broad spectrum pharmaceutical inhibition of matrix metalloproteinase (MMP) activity reduces intraosseous tumor burden and bone degradation in animal models of bone metastasis. Herein, we used specific assays to measure net enzymatic activities of individual MMPs during colonization of bone by prostate cancer cells. PC3 cells were injected into the marrow of human fetal femurs previously implanted in SCID mice. Net MMP-9 activity in bone tissues peaked 2 weeks after injection, coinciding with a wave of osteoclast recruitment. In contrast, MMP-2 and MT1-MMP activity did not change. In vitro, co-culture of PC3 cells with bone tissue led to activation of pro-MMP-9 and increases in secreted net MMP-9 activity. Activation of pro-MMP-9 was prevented by metalloprotease inhibitors but not by inhibitors of other classes of proteases. Ribozyme suppression of MMP-9 expression in PC3 cells did not affect pro-MMP-9 activation or net MMP-9 activity and did not affect the phenotype of bone tumors. siRNA targeting of MMP-9 expression in preosteoclasts in vitro demonstrated that tumor-induced preosteoclast motility was dependent on MMP-9 expression. These data suggest that osteoclast-derived MMP-9 may represent a potential therapeutic target in bone metastasis and provide a rationale for the development of MMP-9-specific inhibitors.

Inhibitory effect of tetrandrine on pulmonary metastases in CT26 colorectal adenocarcinoma-bearing BALB/c mice

Tumor metastasis is a major cause of mortality in cancer patients. The anti-metastatic effect of tetrandrine, an alkaloid isolated from Stephania tetrandrae S. Moore, was investigated in a pulmonary metastatic model of colorectal cancer-bearing mice. Tetrandrine decreased the viability of murine colorectal adenocarcinoma CT26 cells in a time- and dose-dependent manner. CT26 cells were injected into BALB/c mice via a tail vein to establish pulmonary metastases. After this, the mice were given intraperitoneal injections of tetrandrine (10 mg/kg/day), 5-fluorouracil (5-FU) at the same dose, or vehicle for 5 consecutive days. Mice treated with tetrandrine had 40.3% fewer metastases than vehicle-treated mice, and those treated with 5-FU had 36.9% fewer metastases than controls. Both tetrandrine- and 5-FU-treated mice survived longer than mice in the untreated control group. There was no acute toxicity or obvious changes in body weight in any of the mice. These results suggest that tetrandrine may be a useful anti-metastatic agent.

Docosahexaenoic acid reduces in vitro invasion of renal cell carcinoma by elevated levels of tissue inhibitor of metalloproteinase-1

We demonstrate in this study that the n-3 polyunsaturated fatty acids derived from fish oil, namely, eicosapentanoic acid (EPA) and docosahexaenoic acid (DHA), can increase levels of tissue inhibitors of metalloproteinase-1 (TIMP-1) in the renal cell carcinoma cell line caki-1 by 26% and 17.42% respectively. The result of this elevation in TIMP-1 levels is a reduction of 48.48% in caki-1 invasion through the basement membrane component matrigel when cells are treated with DHA. By inhibition of 2-series prostaglandin production, a similar increase in TIMP-1 was observed in caki-1 cells. We conclude that the polyunstaurated fatty acid DHA, a component of fish oil, is capable of significantly reducing the invasive profile of renal cell carcinoma, and that this reduction is regulated by levels of 2-series prostaglandin production.

A new development of matrix metalloproteinase inhibitors: twin hydroxamic acids as potent inhibitors of MMPs

Starting from the observation that the CbzNH(CH2)2 side chain of the potent MMP-2/MMP-14 inhibitor, benzyl-(3R)-4-(hydroxyamino)-3-[isopropoxy(1,1'-biphenyl-4-yl-sulfonyl)amino]-4-oxobutylcarbamate, (R)-1 lies in a hydrophobic region (S1) exposed to the solvent of the protease active site, we hypothesized that an aminoethylcarboxamido chain structurally related to that of (R)-1 might be an useful tool to bind another linker stretching out from the protein. This would be able to interact either with a enzyme region adjacent to the active site, or with other molecules of matrix metalloproteinases (MMPs), or other proteins of the extracellular matrix (ECM) that may be involved in the enzyme activation. On these basis we describe new dimeric compounds of type 2, twin hydroxamic acids, obtained by the joint of two drug entities of (R)-1 linked in P1 by extendable semirigid linkers. Type 2 compounds are potentially able to undergo more complex inhibitor-enzyme interactions than those occurring with monomeric compounds of type 1, thus influencing positively the potency, selectivity and/or cytotoxicity of the new compounds.

Antineovascular therapy, a novel antiangiogenic approach

Angiogenesis is a crucial event in tumour growth, since the growth of tumour cells depends on the supply of essentials such as oxygen and nutrients. Therefore, suppression of angiogenesis is expected to show potent therapeutic effects on various cancers. Additionally, this 'antiangiogenic therapy' is thought not only to eradicate primary tumour cells, but also suppress tumour metastases through disruption of haematogenous metastatic pathways. Tumour dormancy therapy does not aim to disrupt newly formed angiogenic vessels but aims to inhibit further formation of neovessels through inhibiting certain processes of angiogenesis. This raises a question of whether or not these antiangiogenic agents bring complete cure of tumours as complete cut-off of oxygen and nutrients is not expected by the treatment with these agents. This paper will review a novel antiangiogenic therapy, antineovascular therapy (ANET). ANET is categorised in antiangiogenic therapy but is different from tumour dormancy therapy using conventional angiogenic inhibitors: ANET aims to disrupt neovessels rather than to inhibit neovessel formation. ANET is based on the fact that angiogenic endothelial cells are growing cells and would be effectively damaged by cytotoxic agents when the agents are effectively delivered to the neovessels. The complete eradication of angiogenic endothelial cells may cause complete cut-off of essential supplies to the tumour cells and lead to indirect but strong cytotoxicity instead of cytostasis caused by the inhibition of angiogenesis. For the purpose of ANET, an angiogenic vasculature-targeting probe has been developed, by which cytotoxic anticancer agents are actively delivered to the angiogenic endothelial cells by using drug delivery system (DDS) technology. Another way to damage newly formed vessels by cytotoxic agents is achieved by metronomic-dosing chemotherapy. This chemotherapy shifts the target of chemotherapeutic agents from tumour cells to angiogenic endothelial cells by selective dosing schedule. Similarly, the shift of target from tumour cells to angiogenic endothelial cells enhanced therapeutic efficacy of cancer photo-dynamic therapy (PDT): in this antiangiogenic PDT, photosensitizers are delivered more to neovessel endothelial cells than to tumour cells. These therapeutic strategies would be clinically applied in the future.

Peroxisome proliferator activated receptor-γ ligands induced cell growth inhibition and its influence on matrix metalloproteinase activity in human myeloid leukemia cells

Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) is one of the best characterized nuclear hormone receptors (NHRs) in the superfamily of ligand-activated transcriptional factors. PPAR-gamma ligands have recently been demonstrated to affect proliferation, differentiation and apoptosis of different cell types. The present study was undertaken to investigate PPAR-gamma ligands induced cell growth inhibition and its influence on matrix metalloproteinase MMP-9 and MMP-2 activities on leukemia K562 and HL-60 cells in vitro. The results revealed that PPAR-gamma expression was detectable in the two kinds of leukemia cells; Both 15-deoxy-delta(12,14)-prostaglandin J2(15d-PGJ2) and troglitazone (TGZ) have significant growth inhibition effects on these two kinds of leukemia cells. These two PPAR-gamma ligands could inhibit the leukemic cell adhesion to the extracellular matrix (ECM) proteins and the invasion through matrigel matrix. The expressions of MMP-9 and MMP-2 as well as their gelatinolytic activities in both HL-60 and K562 cells were inhibited by 15d-PGJ2 and TGZ significantly. We therefore conclude that PPAR-gamma ligands 15d-PGJ2 and TGZ have significant growth inhibition effects on myeloid leukemia cells in vitro, and that PPAR-gamma ligands can inhibit K562 and HL-60 cell adhesion to and invasion through ECM as well as downregulate MMP-9 and MMP-2 expressions. The data suggest that PPAR-gamma ligands may serve as potential anti-leukemia reagents.

Farnesyltransferase inhibitor SCH-66336 downregulates secretion of matrix proteinases and inhibits carcinoma cell migration

The ras oncogenes are among those most frequently found in human cancers. Blocking Ras farnesylation is a promising strategy for arresting cancer growth. Ras activates several signaling pathways with key roles in cellular proliferation, invasion, metastasis and angiogenesis. Furthermore, proteolytic activities of matrix proteinases such as urokinase-type plasminogen activator (uPA) and matrix metalloproteinases (MMPs) are regulated by Ras isoforms. Thus, we investigated the effects of SCH-66336, a farnesyltransferase inhibitor, on secretion of components of the plasminogen activation system as well as on the gelatinases MMP-2 and MMP-9, which play pivotal roles in matrix remodeling. SCH-66336 up to 5 microM did not significantly alter the viability of prostate (PC-3) and renal (Caki-1) cancer cells incubated in serum-depleted medium. SCH-66336 partly inhibited the processing of H-Ras, while levels of mature N-Ras and K-Ras remained unaffected. Under these noncytotoxic conditions, uPA and tPA levels were lowered in culture medium but raised in cell lysates, suggesting inhibition of trafficking pathways. In contrast, SCH-66336 had no effect on uPAR expression or on secreted PAI-1 levels. As expected, the reduction of uPA and tPA activities by SCH-66336 inhibited the conversion of plasminogen to plasmin by about 25% in PC-3 cells. SCH-66336 also inhibited the levels of secreted pro-MMP-2 and pro-MMP-9 as well as the release of their inhibitors TIMP-1 and TIMP-2. SCH-66336 decreased both the adhesion and even more so the migration of PC-3 cells on gelatin. Thus, SCH-66336 inhibited farnesylation in both cancer cell types, and H-Ras functions should be reduced by the drug. In addition, the lower levels of secreted proteinases in the presence of SCH-66336 suggest that reduced matrix remodeling and cell migration should occur in treated tumors.

Regulation of gene expression and inhibition of experimental prostate cancer bone metastasis by dietary genistein

Prostate cancer frequently metastasizes to the bone, and the treatment outcome for metastatic prostate cancer has been disappointing so far. Dietary genistein, derived primarily from soy product, has been proposed to be partly responsible for the low rate of prostate cancer in Asians. Our previous studies have shown that genistein elicits pleiotropic effects on prostate cancer cells, but there are no studies documenting comprehensive gene expression profiles and antitumor effects of dietary genistein on human prostate cancer grown in human bone environment. In this study, we investigated the effects of genistein on PC3 prostate cancer cells and experimental PC3 bone tumors created by injecting PC3 cells into human bone fragments previously implanted in severe combined immunodeficient (SCID) mice (SCID human model). We found that genistein significantly inhibited PC3 bone tumor growth using both prevention and intervention strategies. By using microarray and real-time polymerase chain reaction technology, we found that genistein regulated the expression of multiple genes involved in the control of cell growth, apoptosis, and metastasis both in vitro and in vivo. For example, the expression of various metalloproteinases (MMPs) in PC3 bone tumors was inhibited by genistein treatment, whereas osteoprotegerin was upregulated. MMP immunostaining and transfection experiments also demonstrated that MMP-9 expression was inhibited in PC3 cells in vitro and PC3 bone tumors in vivo after genistein treatment. These results, particularly the in vivo results, demonstrate that dietary genistein may inhibit prostate cancer bone metastasis by regulating metastasis-related genes. Genistein may thus be a promising agent for the prevention and/or treatment of prostate cancer.

Anti-angiogenic activity of the mutant Dutch A(beta) peptide on human brain microvascular endothelial cells

Cerebral amyloid angiopathy is a common pathological feature of patients with Alzheimer's disease (AD) and it is also the hallmark of individuals with a rare autosomal dominant disorder known as hereditary cerebral hemorrhage with amyloidosis-Dutch type. We have shown previously that wild type A(beta) peptides are anti-angiogenic both in vitro and in vivo and could contribute to the compromised cerebrovascular architecture observed in AD. In the present study, we investigated the potential anti-angiogenic activity of the Dutch A(beta)(1-40) (E22Q) peptide. We show that compared to wild type A(beta), freshly solubilized Dutch A(beta) peptide more potently inhibits the formation of capillary structures induced by plating human brain microvascular endothelial cells onto a reconstituted basement membrane. Aggregated/fibrillar preparations of wild type A(beta) and Dutch A(beta) do not appear to be anti-angiogenic in this assay. The stronger anti-angiogenic activity of the Dutch A(beta) compared to wild type A(beta) appears to be related to the increased formation of low molecular weight A(beta) oligomers in the culture medium surrounding human brain microvascular endothelial cells. Using oligonucleotide microarray analysis of human brain microvascular endothelial cells, followed by a genome-scale computational analysis with the Ingenuity Pathways Knowledge Base, networks of genes affected by an anti-angiogenic dose of Dutch A(beta) were identified. This analysis highlights that several biological networks involved in angiogenesis, tumorigenesis, atherosclerosis, cellular migration and proliferation are disrupted in human brain microvascular endothelial cells exposed to Dutch A(beta). Altogether, these data provide new molecular clues regarding the pathological activity of Dutch A(beta) peptide in the cerebrovasculature.

Mechanical properties, proteolytic degradability and biological modifications affect angiogenic process extension into native and modified fibrin matrices in vitro

During initial stages of wound healing, fibrin clots provide a three-dimensional scaffold that induces cell infiltration and regeneration. Here, L1Ig6, a ligand for alphavbeta3 integrin was covalently incorporated within fibrin matrices to explore it as a matrix-immobilized angiogenic factor. Incorporation at concentrations greater than 1 microg/ml reduced the fibrin crosslink density, as reflected by measurements of elastic modulus and swelling. The influence of crosslink density on endothelial cell process extension was characterized by modulating factor XIII concentrations in the coagulation mixture. At low incorporated concentrations of L1Ig6, it was possible to compensate gel elastic modulus via increased factor XIII, but not at high concentrations of L1Ig6. Similar findings were found when matrix swelling was analyzed. Fibrin crosslink density strongly influenced endothelial cell process extension, fewer and shorter processes were observed at high crosslink density. Matrix metalloproteinases (MMPs) were required for process extension and zymography and Western blots identified MMP-2 but not MMP-9. The amount of active MMP-2 increased for endothelial cells cultured in native and L1Ig6-modified matrices or when stimulated with VEGF-A165. The data indicate that distinct matrix properties can be tailored such that they become biologically stimulating and respond to cellular proteolytic activities, being a prerequisite for potential use of such matrices in biomedical applications.

Inhibition of gelatinase B (matrix metalloproteinase-9) by dihydrolipoic acid

Alpha-lipoic acid (LA) is a disulphide-containing fatty acid that is absorbed from the diet and transported to tissues. Once it has been taken up by mammalian cells, LA is reduced to dihydrolipoic acid (DHLA), a vicinal dithiol, and rapidly effluxed into the extracellular milieu. We hypothesized that DHLA may be an effective inhibitor of human gelatinase B (GelB). Purified human GelB was incubated with 0 to 200 µmol/L DHLA, and residual enzyme activity was measured by HPLC using a fluorogenic substrate (matrix metalloproteinase substrate III). DHLA inhibited GelB in a dose-dependent fashion with an IC50of 20 µmol/L. Oxidation of DHLA resulted in a loss of DHLA's capacity to inhibit GelB. The DHLA-mediated inhibition of GelB was independent of the zinc concentration in the reaction buffer. DHLA had no inhibitory effect on gelatinase A. Zymographs of activated neutrophil lysates demonstrated that higher concentrations of DHLA also prevent the activation of GelB proenzyme. Bronchoalveolar lavage fluid from mice fed a diet enriched with LA showed significantly increased GelB inhibitory capacity (p = 0.0002 vs. regular diet). We conclude that DHLA can modulate neutrophil-derived GelB activity through direct inhibition of enzyme activity and by preventing the activation of GelB proenzyme.Key words: matrix metalloproteinases, pulmonary fibrosis, thiols, neutrophils, inflammation.

N-i-Propoxy-N-biphenylsulfonylaminobutylhydroxamic acids as potent and selective inhibitors of MMP-2 and MT1-MMP

Structural manipulation of the pharmacophoric model of type A selective MMP inhibitors (MMPi), obtained by the insertion of some alkyl substituents R2 possessing an appropriate geometry, steric bulkiness and lipophilicity, is able to improve potency, in the subnanomolar range on MMP-2, and to give a good MMP inhibition on MMP-14 (MT1-MMP) in the designed MMPi of type C, while maintaining a good MMP-1/MMP-2 selectivity profile. The simultaneous inhibition of these two enzymes yields type C compounds, which are potent antiangiogenic agents, able to block a chemoinvasion model on HUVEC cells in the micromolar range.

Leptin and prostate: implications for cancer prevention--overview of genetics and molecular interactions

Leptin's relation with obesity has been clearly demonstrated while its role in oncobiology is still largely unknown. Epidemiological studies on serum leptin provide valuable though controversial data, while in vitro studies consistently show leptin's angiogenic and proliferative potential in cancer. Leptin's activity is mediated by tissue-specific receptors, differentially expressed in organs such as the prostate. The molecular cascades triggered by leptin result in prostatic cell proliferation and angiogenic activity, thus linking the hormone mainly to prostate cancer prognosis. This review also addresses leptin's metabolic interactions with cytokines, growth factors or hormones, establishing perceptive pathways leading to carcinogenesis or prostate cancer progression and metastasis. Better understanding of these mechanisms may help in the development of new and more effective treatments for prostate cancer. The consolidation of leptin molecular genetics profile in prostate cancer patients may help to create susceptibility groups in normal individuals, facilitating a preventive dietary intervention or strategies for chemoprevention. We hypothesize that the balance between androgen and leptin levels may facilitate the increase in the ratio of androgen-independent prostate cancer cells to androgen-dependent cells in the tumour.

Comparison of expression of cathepsins B and L and MMP2 in endothelial cells and in capillary sprouting in collagen gel

The lysosomal cysteine proteinases cathepsins B and L are known to play an important role in the invasive growth of tumor cells, but their association with angiogenesis has been less well studied. The aim of this study was to determine the possible role of endothelial cell-associated cathepsins B and L in induced capillary growth in the aorta ring model of angiogenesis. Specific inhibitors of cysteine proteinases did not inhibit capillary growth in aorta ring culture and only slightly inhibited the degradation of surrounding collagen. In contrast, strong inhibition of both processes by the matrix metalloproteinase inhibitor BB-94 was observed, indicating the importance of endogenous MMP production in angiogenesis. In support of this finding, we demonstrated a significant increase in endogenous endothelial mRNA of MMP2, but not of cathepsins B and L, in proliferating primary human dermal microvascular endothelial cells (HMVEC-d) in culture. However, MMP2 mRNA expression was increased only when the cells were embedded in collagen but not when they were grown on plastic, regardless of the addition of the growth factors VEGF or bFGF. Moreover, on plastic the impairment of MMP2 induction by growth factors was observed. The differential effect of growth factors implies the crosstalk with integrin signaling as a consequence of binding to the different matrix. This study suggests that endothelial cell-associated cathepsins B and L are not involved in the invasive growth of capillaries from existing blood vessels and that the presence of collagen is necessary for MMP2 expression in endothelial cells.

Histological quantitation of tumour angiogenesis

Tumours establish their blood supply via a number of processes in addition to angiogenesis. These include vasculogenesis, vascular remodelling, intussusception and possibly vascular mimicry in certain tumours. The mainstay of the assessment of tumour vascularity has been counting the number of immunohistochemically identified microvessels in vascular hot spots. Nevertheless, several other techniques are available, including Chalkley counting, vascular grade and the use of image analysis systems. Angiogenic activity can furthermore be assessed in histological samples by measuring the molecules involved in the establishment of the tumour vasculature, including angiogenic growth factors and their receptors, cell adhesion molecules, proteases and markers of activated, proliferating, cytokine stimulated or angiogenic vessels, such as CD105. Measuring the maturity of vessels may give an indication of the proportion of the tumour vasculature that is functional. Other reagents that can identify hypoxia-activated pathways are also being developed. The histological assessment of tumour vascularity is mainly used in the research setting but may also have applications in the clinic if appropriate methodology and trained observers perform the studies. Gene arrays may be able to provide an angiogenesis profile. Continued study into the processes involved in generating a tumour blood supply is likely to identify new markers that may be more accurate measures.

Nonantimicrobial Effects of Antibacterial Agents

One of the major advances in modern medicine was the development of antimicrobial chemotherapy. However, many antibacterial agents have unexpected or undesirable nonantimicrobial effects on humans. Microbes and man share many essentials of life, including DNA, adenosine triphosphate, and other biochemical pathways. Hence, some of these nonantimicrobial effects may also turn out to be pharmacologically useful. Oral hypoglycemic agents (i.e., sulfonylureas) and a certain diuretic agent (acetazolamide) are derivatives of sulfonamides. Erythromycin has been used clinically for its stimulatory effect on gastrointestinal motility. Macrolides, lincosamides, and tetracyclines have been known for their immunomodulatory effects. A tetracycline has been used to treat the syndrome of inappropriate antidiuretic hormone. Aminoglycosides may influence mucus production in patients with cystic fibrosis. Other antimicrobials may have side effects that are not therapeutically useful, such as osmotic diuresis with high-dose beta -lactam administration, neuromuscular blockade of aminoglycosides, dysglycemia of fluoroquinolones, and serotonin syndrome with oxazolidinones.

Farnesyltransferase inhibitor effects on prostate tumor micro-environment and radiation survival

BACKGROUND

Ras activation by mutation, overexpression, or receptor signaling can increase tumor cell survival after irradiation.

METHODS

We examined whether inhibiting Ras activity with farnesyltransferase inhibitors (FTI) altered the radiosensitivity and tumor micro-environment in prostate tumors.

RESULTS

Treatment with FTIs L-744,832 or FTI-277 reduced clonogenic survival of prostate tumor cells expressing oncogenic H-ras after irradiation. PI3-kinase/Akt and MAPK signaling pathways were downregulated by FTIs in these cells. FTI treatment reduced tumor hypoxia and also reduced MMP-9 expression in tumors with activated mutant H-ras. FTI treatment did not, however, increase apoptosis in irradiated intestine, demonstrating that acute radiation injury of this normal tissue was not enhanced by FTIs.

CONCLUSIONS

FTIs can enhance the killing of prostate tumors with activated H-Ras. Together with the absence of increased acute toxicity to normal bowel, these results imply that FTI treatment should be further studied as a possible adjuvant to radiotherapy in the treatment of abdominal cancers with activated Ras signaling.

The possible role of matrix metalloproteinase (MMP)-2 and MMP-9 in cancer, e.g. acute leukemia

In the past decades, a lot of effort has been put in identifying the role of matrix metalloproteinases (MMPs) in cancer. The main role of MMPs in angiogenesis, tumor growth and metastasis is degradation of extracellular matrix (ECM) and release and/or activation of growth factors through their degradative activity. The degradative activity finally results in cancer progression. MMP-inhibitors (MMPIs) have already been designed and tested, based on the degradative role of MMPs in cancer progression. First clinical trials with MMPIs have been performed with disappointing results, showing that in order to use MMP-inhibition the mechanisms underlying MMP-expression in cancer have to be further elucidated. This paper reviews the mechanisms of MMPs on molecular and cellular level and discusses the role for MMPs and MMP-inhibition in cancer with special focus on acute leukemia.

Expression of matrix metalloproteinase-9 in head and neck squamous cell carcinoma: a potential marker for prognosis

PURPOSE

Previous studies have shown that matrix metalloproteinase-9 (MMP-9) is expressed in malignant head and neck squamous cell carcinoma. The prognostic role of MMP-9 is still unclear. The aim of this study was to investigate the role of MMP-9 immunoreactive protein as a prognostic marker for survival in head and neck squamous cell carcinoma.

EXPERIMENTAL DESIGN

Overexpression of the immunoreactive protein for MMP-9 was evaluated in tissue sections of 74 primary head and neck carcinomas with a monoclonal antibody using a biotin-streptavidin immunohistochemical staining method. The staining results were compared with the clinical data and to the patients' outcome.

RESULTS

Positive immunostaining for MMP-9 was observed in 82% of the head and neck carcinomas, 39% of the cases being extensively positive. MMP-9 protein expression was independent of the stage or the grade of the tumor. The expression of MMP-9 was prognostic for shortened survival, the 5-year cause-specific survival being 45% in MMP-9 positive cases, and 92% in cases negative for MMP-9 (P = 0.013). MMP-9 positivity also correlated to the relapse-free survival (P = 0.019). At the 5-year follow-up, the cumulative relapse-free survival rate was 79% for patients with MMP-9-negative tumor and 42% for the patients with positive immunostaining for MMP-9. High expression of MMP-9 seemed to be linked with more aggressive relapses, appearing in 33% of the cases in local relapses, in 52% of cases with lymph node relapses, and in 60% of the cases with hematogenic relapses.

CONCLUSIONS

This is the first study with a long follow-up showing that the immunoreactive protein of MMP-9 in head and neck carcinoma is associated with shortened relapse-free and cause-specific survival, suggesting that MMP-9 has a role in tumor progression of head and neck carcinomas, as well as in estimation of the prognosis of these diseases.

Expression of matrix metalloproteinases and their specific inhibitors in normal and different human thyroid tumor cell lines

In the present study we investigated, by means of zymography and reverse transcription-polymerase chain reaction (RT-PCR), the expression of different matrix metalloproteinases (MMPs) and of the specific tissue inhibitor of metalloproteinases [TIMPs] in human cell lines derived from normal thyrocytes (HTU5), follicular adenoma (HTU42), and follicular (FTC-133), papillary (B-CPAP), and anaplastic (CAL-62, 8305C) thyroid carcinomas. We demonstrated that normal thyrocytes constitutively express MMP-1, MMP-2, MMP-10, MMP-14, and TIMP-1, TIMP-2, TIMP-3, and TIMP-4, and this pattern of expression is profoundly modified in all thyroid tumor-derived cell lines. Analysis of the gelatinolytic activity in the different cell supernatants showed that the expressions of MMP-2 and MMP-9 are, respectively, increased or induced in all the neoplastic cell lines, except in CAL-62. Caseinolytic activity was found only in the supernatants of the 8305C and B-CPAP cells. Using RTPCR analysis we detected an increased expression of MMP-1 in cell lines derived from papillary and from one (8305C) of the two anaplastic carcinomas. MMP-13 mRNA was expressed only in the 8305C, FTC-133, and BCPAP cells. Among stromelysins, MMP-3 mRNA could not be detected in any cell line, while MMP-10 mRNA was expressed in all of them, although at variable levels. MMP-11 mRNA was absent in normal and follicular adenoma derived thyrocytes and induced in all carcinoma cell types. The expression of MMP-14 (MT1-MMP) mRNA was found significantly increased in all thyroid tumor cell lines with respect to HTU5 and HTU42 cells. The expression of TIMP-1 and TIMP-2 mRNAs was maintained in all cell lines tested, while that of TIMP-3 was lost in both anaplastic carcinoma cell lines and that of TIMP-4 was absent in the CAL-62. In conclusion, our data demonstrated a differential expression of MMPs and TIMPs in different thyroid tumor cell types with respect to normal thyrocytes. In particular, the induction of MMP-11 in all thyroid-derived carcinoma cell lines studied and of MMP-13 in all but one may represent, if confirmed in other thyroid tumor-derived cell lines and in thyroid tumor tissues, a new marker of thyrocyte transformation.

Matrix metalloproteinases and atherosclerosis

Atherosclerosis is a major cause of coronary heart disease, and matrix metalloproteinases (MMPs) play an important role in atherosclerosis by degrading the extracellular matrix, which results in cardiovascular remodeling. Recent studies have identified enhanced expression of MMPs in the atherosclerotic lesion and their contribution to weakening of the vascular wall by degrading the extracellular matrix. The transcription, enzyme processing, and specific inhibition of MMPs by tissue inhibitors of matrix metalloproteinase (TIMPs) regulate these effects. These processes are also modified by inflammatory cytokines and cell-cell contact signaling. Both animal experiments and clinical sample analysis have shown that balance in expression and activation of MMPs and inhibition by TIMPs is critical for the development of stenotic and aneurysmal change. Polymorphism in the MMP gene promoter contributes to inter-individual differences in susceptibility to coronary heart disease. The development of therapeutic drugs specifically targeting MMPs may thus be useful for the prevention of atherosclerotic lesion progression, plaque rupture, and restenosis.

Type IV collagenase (matrix metalloproteinase-2 and -9) in prostate cancer

BACKGROUND

The type IV collagenases/gelatinases matrix metalloproteinase-2 (MMP-2) and -9 (MMP-9) play an important role in cancer invasion and metastasis. In the present study, we measured the expression of mRNAs and enzymatic activities of MMP-9 and -2 in prostate tissues and serum samples from men with or without prostate cancer.

METHODS

A total of 44 tissue samples (three from healthy volunteers, 21 from patients with benign prostate hyperplasia, 10 from patients with localized prostate cancer and 10 from patients with metastatic disease) and 71 serum samples were collected (20 from healthy volunteers, 26 from patients with benign prostatic hyperplasia, 10 from patients with localized cancer, 15 from patients with metastatic cancer). The level of mRNA for MMP-2 and -9 was determined by semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR). The enzymatic activity of MMPs was determined by zymography.

RESULTS

Expression of MMP-9 mRNA was significantly higher in malignant than in nonmalignant prostate tissues (P < 0.001), while no significant difference of MMP-2 expression was detected in different prostate tissues. Results of zymography showed that there was significant difference in the enzymatic activity of MMP-9, but not MMP-2, among normal prostate, BPH, localized and metastatic prostate cancer tissues, serum samples (P < 0.05). The active form of MMP-2, with a molecular mass of 62 kDa, was detected in normal prostate, BPH and prostate cancer tissues, but not in the serum samples. Moreover, there was a significant difference in the ratio of the active form (62 kDa) and proform (72 kDa) of MMP-2 among normal, BPH and prostate cancer tissues. This ratio was further increased in metastatic prostate cancer tissues.

CONCLUSION

The activity of MMP-9 and the ratio of active form/proform of MMP-2 are associated with the progression and metastasis of prostate cancer.

(−)-Epigallocatechin gallate inhibits membrane-type 1 matrix metalloproteinase, MT1-MMP, and tumor angiogenesis

Membrane-type 1 matrix metalloproteinase (MT1-MMP), which hydrolyzes type I collagen and activates MMP-2, are deeply involved in angiogenesis as well as in tumor cell invasion and metastasis. We previously screened a number of natural and synthetic compounds to obtain a specific inhibitor of MT1-MMP and observed that (-)-epigallocatechin gallate (EGCG) has a potent and distinct inhibitory activity against MT1-MMP. In the present study, we investigated the effect of EGCG on tumor angiogenesis. EGCG significantly inhibited the invasion of human umbilical vein endothelial cells (HUVECs) at the concentration of 10 microM. This effect was not due to the toxicity of EGCG since this concentration of EGCG did not affect the HUVEC growth. Furthermore, morphological change of HUVEC at this concentration of EGCG was not observed under confocal laser scanning microscopy. EGCG suppressed tube formation by HUVECs in vitro and angiogenesis in vivo by using dorsal air sac model. Finally, we observed that both colon 26 NL17 carcinoma and Meth A sarcoma growth was suppressed in these tumor-bearing mice by EGCG administration, at least partly though the inhibition of angiogenesis.

RETRACTED: Proanthocyanidins from grape seeds inhibit expression of matrix metalloproteinases in human prostate carcinoma cells, which is associated with the inhibition of activation of MAPK and NFκB

Prostate cancer (PCA) is the second most frequently diagnosed and leading cause of cancer-related deaths in men in the USA. The recognition that matrix metalloproteinases (MMPs) facilitate tumor cell invasion and metastasis of PCA has led to the development of MMP inhibitors as cancer therapeutic agents. As part of our efforts to develop newer and effective chemopreventive agents for PCA, we evaluated the effect of proanthocyanidins from grape seeds (GSP) on metastasis-specific MMP-2 and -9 in human prostate carcinoma DU145 cells by employing western blot and gelatinolytic zymography. Treatment of GSP dose-dependently inhibited cell proliferation (15-100% by 5-80 microg/ml of GSP), viability (30-80% by 20-80 microg/ml of GSP) and fibroblast conditioned medium (FCM)-induced expression of MMP-2 and -9 in DU145 cells. Since the signaling cascade of mitogen-activated protein kinases (MAPK) have been shown to regulate the expression of MMPs in tumor cells, we found that the treatment of DU145 cells with GSP (20-80 microg/ml) resulted in marked inhibition of FCM-induced phosphorylation of extracellular signal regulated kinase (ERK)1/2 and p38 but had little effect on c-Jun N-terminal kinase under similar experimental conditions. GSP treatment (20-80 microg/ml) to DU145 cells also dose-dependently inhibited FCM-induced activation of NF kappa B concomitantly with inhibition of MMP-2 and -9 expression in the same system. Additionally, the treatment of inhibitors of MEK (PD98059) and p38 (SB203580) to DU145 cells resulted in the reduction of FCM-induced phosphorylation of ERK1/2 and p38 concomitantly marked reduction in MMP-2 and -9 expressions. In further studies, treatment of androgen-sensitive LNCaP cells with a synthetic androgen R1881, resulted in an increase of MMP-2 and -9, which were completely abrogated in the presence of GSP (20-60 microg/ml). These data suggest that inhibition of metastasis-specific MMPs in tumor cells by GSP is associated with the inhibition of activation of MAPK and NF kappa B pathways, and thus provides the molecular basis for the development of GSP as a novel chemopreventive agent for both androgen-sensitive and -insensitive prostate cancer therapies.

[Therapy of malignant melanoma at the stage of distant metastasis]

Treatment of melanoma in the stage of distant metastasis aims on palliation and achievement of durable tumor remission with prolongation of survival. As long as metastasis is confined to one organ system and is removable, surgery remains the treatment of first choice. In limited metastasis radiotherapy may likewise be indicated, particularly in bone and brain metastasis. More extensive metastasis should be treated by chemotherapy or chemoimmunotherapy. Monochemotherapy with dacarbazine, temozolomide, fotemustine and vindesine or its combinations with interferon-alpha are currently preferred. Polychemotherapy or its combinations with interferon-alpha and interleukin-2 are suitable to produce higher response rates but failed to prolong survival. As these treatments are associated with substantially higher toxicity they have been widely abandoned. Combined treatment with dacarbazine and interferon-alpha obtain tumor responses or stable disease in 40-50% and objective tumor remissions in 15-20% of patients. Effective cancer vaccination strategies and blockade of melanoma specific target molecules are currently developed as new treatment options.

New N-arylsulfonyl-N-alkoxyaminoacetohydroxamic acids as selective inhibitors of gelatinase A (MMP-2)

New N-arylsulfonyl-substituted alkoxyaminoaceto hydroxamic acid derivatives of types 8 and 10 designed as oxa-analogues of known sulfonamide-based MMPi of types 2 and 7 were synthesized and tested for their inhibitory activities on some matrix metalloproteinases. The combination of a biphenylsulfonamide group with oxyamino oxygen in the pharmacophoric central skeleton of sulfonamide-based MMPi obtained in the new sulfonamides 10 seems to be able to give selectivity for MMP-2 over MMP-1. The most potent derivative of this type, 10a, shows similar anti-invasive properties to the analogue reference drug CGS27023A, 2, in an in vitro model of invasion on matrigel, carried out on cellular lines of fibrosarcoma HT1080 (tumoural cells over-expressing MMP-2 and MMP-9).