Collagenolytic mechanisms in tumor cell invasion

Diclofenac conjugates with biocides through silver(I) ions (CoMeD's); Development of a reliable model for the prediction of anti-proliferation of NSAID's-silver formulations

The conjugation of diclofenac (DICLH), a Non-Steroidal Anti-inflammatory Drug (NSAID), with biocides such as dimethyl sulfoxide (DMSO) and triphenylphosphine (TPP), through silver(I) ions, results into the chemical [Ag_n(DICL)_n(L)_m]_k (L = DMSO and n = 2, m = 2, k = infinite (1); L = TPP and n = 1, m = 2, k = 1 (2)). The compounds were characterized by m.p., FT-IR, UV-vis and ¹H NMR spectroscopic techniques. The crystal and molecular structures of 1-2 were determined by X-ray crystallography. The in vitro cytotoxic activity of 1-2 against the human breast adenocarcinoma cancer cells MCF-7 (hormone dependent) and MDA-MB-231 (hormone independent) reveals that the 1 inhibits the MCF-7 rather than the MDA-MB-231 cells, suggesting hormone mimetic behaviour. Compound 2 inhibits both cancerous cell lines, stronger than cisplatin. Both compounds inhibit MCF-7 cells migration. Compounds 1-2, exhibit, lower toxicity against fetal lung fibroblast (MRC-5) cells than cisplatin. Their genotoxicity was evaluated on MRC-5 cells. The molecular mechanism of 1-2 against MCF-7 cells was clarified by (i) their cell cycle arrest study (ii) their mitochondrial membrane permeability (iii) their binding affinity towards Calf Thymus (CT)-DNA and (iv) their inhibitory activity against the enzyme lipoxygenase (LOX). Regression analysis of the data obtained for [Ag(NSAID)(Ar₃P)_m] (NSAID = p‑hydroxy‑benzoic acid (p-HO-BZAH), salicylic acid (SALH₂), aspirin (ASPH), naproxen (NAPRH), nimesulide (NIMH); L = TPP, Tri(p‑tolyl)phosphine (TPTP), Tri(o‑tolyl)phosphine (TOTP), Tri(m‑tolyl)phosphine (TMTP); m = 2 or 3) and [Ag(DICL)₂(DMSO)₂]_k (k = infinite) was performed. Considering the biological results (IC₅₀) as dependent variable a theoretical equation is obtained for these compounds. The calculated IC₅₀ values are compared satisfactorily with the corresponding experimental inhibitory activity of the complexes.

The emerging roles of macrophages in cancer metastasis and response to chemotherapy

Macrophages represent a heterogeneous group of cells, capable of carrying out distinct functions in a variety of organs and tissues. Even within individual tissues, their functions can vary with location. Tumor-associated macrophages (TAMs) specialize into three major subtypes that carry out multiple tasks simultaneously. This is especially true in the context of metastasis, where TAMs establish most of the cellular and molecular prerequisites for successful cancer cell dissemination and seeding to the secondary site. Perivascular TAMs operate in the perivascular niche, where they promote tumor angiogenesis and aid in the assembly of intravasation sites called tumor microenvironment of metastasis (TMEM). Streaming TAMs co-migrate with tumor cells (irrespective of the perivascular niche) and promote matrix remodeling, tumor cell invasiveness, and an immunosuppressive local microenvironment. Premetastatic TAMs are recruited to the premetastatic niche, where they can assist in tumor cell extravasation, seeding, and metastatic colonization. The dynamic interplay between TAMs and tumor cells can also modify the ability of the latter to resist cytotoxic chemotherapy (a phenotype known as environment-mediated drug resistance) and induce chemotherapy-mediated pro-metastatic microenvironmental changes. These observations suggest that future therapeutics should be designed to target TAMs with the aim of suppressing the metastatic potential of tumors and rendering chemotherapy more efficient.

Identification of potential biomarkers of lung adenocarcinoma brain metastases via microarray analysis of cDNA expression profiles

Brain metastases originating from lung adenocarcinoma (LAD) occur frequently. The aim of the current study was to assess potential biomarkers for the prognosis of lung adenocarcinoma brain metastasis (LAD-BM) through the analysis of gene expression microarrays. The current study downloaded two gene expression datasets, GSE14108 and GSE10245, from the Gene Expression Omnibus database. From GSE14108 and GSE10245, 19 LAD-BM samples and 40 primary LAD samples were selected for analysis. To identify the differentially expressed genes (DEGs), the current study compared the two sample groups, using the limma R package. Subsequently, pathway enrichment analysis was conducted using the Cluster Profiler R package, and the construction of the protein-protein interaction (PPI) network was executed utilizing the Search Tool for the Retrieval of Interacting Genes database. The microRNA-target network was built using the TargetScore R package. Then, these networks were established and visualized using Cytoscape software. An array of 463 DEGs was identified in the LAD-BM samples, including 256 upregulated and 207 downregulated genes. Based on functional term enrichment analysis using the Gene Ontology database and signaling pathway enrichment analysis using the Kyoto Encyclopedia of Genes and Genomes database, it was identified that the overlapping DEGs were primarily involved in chemokine-associated signal transduction, which may mediate lung cancer cell metastasis to the brain. Chemokine ligand 2, lysozyme, matrix metalloproteinase-2 (MMP-2), lysyl oxidase (LOX) and granzyme B were identified as potential biomarkers according to a topological analysis of the PPI networks. Two notable nodes, MMP-2 and LOX, appeared in the PPI network and were key points in the microRNA-target network, as they were regulated by hsa-let-7d. Many DEGs and microRNAs were regarded as prognostic biomarkers for lung adenocarcinoma metastasis in the current study. These DEGs were primarily associated with chemokine-mediated signaling pathways. In addition, MMP-2 and LOX were predicted to be targets of hsa-let-7d.

Estrogen receptor beta participate in the regulation of metabolizm of extracellular matrix in estrogen alpha negative breast cancer

The biology of breast cancer is closely releted to sex steroid hormones. Estrogen receptor beta is overexpressed in around 70% breast cancer cases, referrd to as "ER positive". Estrogens bind to estrogen receptor and stimulate the transcription of genes involved in control of cell proliferation. Moreover, estrogens may induce growth factors and components of extracellular matrix and interact with them in a complex manner. Extracellular matrix and integrins play an important role in cell functions and their aberrant expressions are implicated in breast cancer development, invasion and metastasis. ER beta is certainly associated with more differentiated tumors, while evidence of role of ER beta is controversial. The highly invasive breast cancer ER beta negative cell line MDA-MB 231 can be the model of exam the role of ER beta in breast cancer. The aim of this study was to examine the role of activation of ER beta on the metabolism of the extracellular matrix and the expression of beta-1 integrin in the breast cancer cell line MDA-MB 231. The cells were exposed on the estradiol, tamoxifen, raloxifen and genisteina in dose dependent concentrations. To determine the relative rate of collagen syntesis we measured the time-dependent reduction of collagen-bound radioactivity after pulse-chase labeling with [3 H] prolina by Peterkofsky methods. The expression of beta-1 integrin was determine by Western blot analysis. The activity of MMP2 and 9 were measured using gelatin zymography with an image analysis system. Our data suggest on the role of estrogen receptor beta on the metabolism of extracellular matrix in the breast cancer line MDA - MB 231. Estradiol and SERMs regulate the expression of ECM proteins: collagen, integrins and enhance activity of metaloproteinases 2 and 9.

Melanoma associated spongiform scleropathy: characterization, biochemical and immunohistochemical studies

SUMMARY

Melanoma associated spongiform scleropathy (MASS) is a non-inflammatory scleral change with a spongiotic morphology seen in association with uveal melanoma. MASS is seen as whitish spindle shaped areas within the sclera that is adjacent to and in contact with a choroidal or ciliary body melanoma. This change can be seen as small scattered lesions in the inner scleral layers or as extensive areas along the whole extent of contact between the tumour and the sclera and involves most of the scleral thickness. MASS changes of different grades of severity were seen in 38% of 363 melanoma eyes investigated. The presence of MASS showed a statistical correlation with age. A significant high incidence of MASS was found in old age groups. This might due to the fact that MASS needs a longer period of contact between the tumour and the sclera to develop. It is also possible that age-related changes of the extracellular matrix might alter its response to melanoma produced factors leading to the development of MASS. The development of MASS and its severity are influenced by the extent of contact between the tumour and the sclera. This is supported by the significant statistical relation between the largest basal diameter of the tumours and the severity of MASS. Statistical correlation was found between MASS and scleral and extrascleral tumour extension. More than 90% of 82 specimens that showed tumour extension were associated with MASS. A biochemical analysis of scleral samples taken from areas with severe MASS showed a significant reduction of the main amino acids of collagen type I, which is the main scleral collagen. The amounts of total scleral proteins were significantly reduced. This scleral protein reduction is associated with an increase in glycosaminoglycans. These findings indicate a collagen degradation process. Immunohistochemical studies were performed to investigate the expression of matrix metalloproteinases (MMPs). In situ hybridization showed a significantly more frequent and more intense expression of MMP-2 by scleral fibroblasts in areas with MASS compared with areas without MASS. This was also seen by immunohistochemical staining. Similar high frequency and intense expression of MMP-2 were seen in tumour infiltrating macrophages. The results of biochemical and immunohistochemical studies indicate a collagen degradation process. This degradation may be the result of the proteolytic enzyme MMP-2 expressed by scleral fibroblasts under the effect of tumour humeral factors and/or tumour infiltrating macrophages. This scleral degradation results in fragmentation of the scleral collagen fibrils. This along with the accumulation of water in the sclera, as a result of the increase in the production of glycosaminoglycans, results in increase of scleral thickness in MASS areas and forms the histopathological picture of MASS. The scleral degradation may facilitate tumour invasion and may explain the statistical relation between MASS and scleral tumour invasion. MASS was found in a few of the eyes that had received pre-enucleation radiation. The possible explanation is that radiation might cause destruction of scleral fibroblasts reducing their ability to produce MMP-2, thus decreasing the development of MASS. No relation between MASS and survival was found. This is probably explained by the fact that the main cause of death due to uveal melanoma is distant metastasis. MASS changes are found to be associated with local tumour invasion but not statistically correlated to survival.

The role of autocrine motility factor in tumor and tumor microenvironment

Autocrine motility factor (AMF) is a tumor-secreted cytokine and is abundant at tumor sites, where it may affect the process of tumor growth and metastasis. AMF is a multifunctional protein capable of affecting cell migration, invasion, proliferation, and survival, and possesses phosphoglucose isomerase activity and can catalyze the step in glycolysis and gluconeogenesis. Here, we review the role of AMF and tumor environment on malignant processes. The outcome of metastasis depends on multiple interactions between tumor cells and homeostatic mechanisms, therefore elucidation of the tumor/host interactions in the tumor microenvironment is essential in the development of new prevention and treatment strategies. Such knowledge might provide clues to develop new future therapeutic approaches for human cancers.

Effect of collagen turnover and matrix metalloproteinase activity on healing of venous leg ulcers

Background

The presence of fibrous tissue in poorly healing venous leg ulcers suggests abnormal collagen metabolism. The aim was to determine whether there were differences in collagen turnover and matrix metalloproteinase (MMP) activity between ulcers that healed, those that did not heal and normal skin.

Methods

Biopsies were taken from the ulcers of 12 patients whose venous ulcers went on to heal and 15 patients whose ulcers failed to heal despite 12 months of compression bandaging. Biopsies were taken from 15 normal controls. Collagen turnover (collagen III N-terminal propeptide (PIIINP) and degraded collagen), and total MMP, MMP-1 and MMP-3 activities were measured.

Results

PIIINP and degraded collagen levels were higher in ulcers that healed compared with lesions that failed to heal (P = 0·005 and P < 0·001 respectively) and normal skin (P = 0·003 and P < 0·001). MMP-1 activity was also higher in healing ulcers than resistant ulcers (P < 0·001) and normal skin (P < 0·001). Significantly more total MMP activity was present in all ulcers than in normal skin (P < 0·001), but there was no difference in total MMP (and MMP-3 activity) between ulcers that healed and those that did not.

Conclusion

Rapidly healing venous leg ulcers had increased collagen turnover and MMP-1 activity, which appeared to differentiate them from those that failed to heal within 12 months.

Prognostic significance of immunoreactive neutrophil elastase in human breast cancer: long-term follow-up results in 313 patients

OBJECTIVE

We have measured the concentration of immunoreactive neutrophil elastase (ir-NE) in the tumor extracts of 313 primary human breast cancers. Sufficient time has elapsed, and we are now ready to analyze its prognostic value in human breast cancer.

METHODS

ir-NE concentration in tumor extracts was determined with an enzyme-linked immunosorbent assay that enables a rapid measurement of both free-form ir-NE and the A1-protease inhibitor-complexed form of ir-NE. We analyzed the prognostic value of this enzyme in human breast cancer in univariate and multivariate analyses.

RESULTS

Patients with breast cancer tissue containing a high concentration of ir-NE had poor survival compared to those with a low concentration of ir-NE at the cutoff point of 9.0 microg/100 mg protein (P = .0012), which had been previously determined in another group of 49 patients. Multivariate stepwise analysis selected lymph node status (P = .0004; relative risk = 1.46) and ir-NE concentration (P = .0013; relative risk = 1.43) as independent prognostic factors for recurrence.

CONCLUSIONS

Tumor ir-NE concentration is an independent prognostic factor in patients with breast cancer who undergo curative surgery. This enzyme may play an active role in tumor progression that leads to metastasis in human breast cancer.

Targeting the over-expressed urokinase-type plasminogen activator receptor on glioblastoma multiforme

A recombinant fusion protein targeting the urokinase-type plasminogen activator receptor (uPAR) and delivering a potent catalytic toxin has the advantage of simultaneously targeting both over-expressed uPAR on glioblastoma cells and on the tumor neovasculature. Such a hybrid protein was synthesized consisting of the noninternalizing amino-terminal fragment (ATF) of urokinase-type plasminogen activator (uPA) for binding, and the catalytic portion of diphtheria toxin (DT) for killing, and the translocation enhancing region (TER) of DT for internalization. The protein was highly selective for human glioblastoma in vitro and in vivo. In vivo, this DT/ATF hybrid called DTAT caused the regression of small subcutaneous uPAR-expressing tumors with minimal toxicity to critical organs. In vitro, DTAT killed only uPAR-positive glioblastoma cell lines and human endothelial cells in the form of the HUVEC cell line. Killing was selective and blockable with specific antibody. DTAT was highly effective against tumor cells cultured from glioblastoma multiforme patients and in vitro mixing experiments combining DTAT with DTIL13 another highly effective anti-glioblastoma agent showed that the mixture was as toxic as the most potent immunotoxin. In this article, we review our progress to date with DTAT.

Melanoma-associated spongiform scleropathy: biochemical changes and possible relation to tumour extension

PURPOSE

To investigate biochemical changes of the sclera in eyes with melanoma-associated spongiform scleropathy (MASS), and to analyse possible relationships between these changes and tumour extension.

METHODS

Sections from 364 eyes, enucleated for choroidal and ciliary body melanoma, were examined for MASS and scleral tumour extension. Biochemical analysis was also performed on eight scleral specimens with MASS and eight specimens (controls) from morphologically normal sclera of the same eyes. The scleral thickness of each specimen was measured. Samples were delipidized, dried and weighed. The weight ratios of collagen-related amino acids were calculated based on quantitation by liquid chromatography. Amounts of glycosaminoglycans (GAGs) were determined by electrophoresis.

RESULTS

Melanoma-associated spongiform scleropathy was seen in 140 eyes (38.5%). Tumour scleral extension was observed in 82 eyes. Of these 82 eyes, 75 (91.5%) had MASS (p<0.05). Biochemically, the majority of the main amino acids of the scleral collagen and total proteins were significantly lower in areas with MASS than in the control specimens. Specific GAGs and total GAGs were found in significantly higher concentrations in areas with MASS than in the control specimens. Scleral thickness was also significantly higher in areas with MASS than in the control specimens.

CONCLUSIONS

The reduced content of collagen manifested by decreased amino acids and total proteins indicates collagen degradation in the vicinity of the tumour. The concomitant excessive deposition of GAGs accumulates water and may cause loosening of the already degraded collagen bundles, giving a histopathological picture of MASS. These changes could facilitate tumour cell migration and may explain the high incidence of MASS in eyes with scleral tumour extension.

Increased Expression of Matrix Metalloproteinase 9 Correlates with Poor Prognostic Variables in Renal Cell Carcinoma

BACKGROUND

MMP2 and MMP9 are two gelatinolytic enzymes, which are key regulators of tumor invasion and metastasis. This study aimed to clarify the prognostic significance of MMP2 and MMP9 with particular regard to their transcript levels, enzymatic activities in renal cell carcinomas (RCCs).

MATERIALS AND METHODS

Through cDNA array, the differential expression of the MMP superfamily was evaluated in RCC. Various properties of MMP2 and MMP9 were quantified, in 178 patients with RCC, based on the Heidelberg classification. Of these, 145 cases including 16 fresh-frozen cases were available for MMP2 and MMP9 transcript level evaluation. In addition, gelatinolytic activity was assessed by zymography in 16 other fresh-frozen samples from new RCC cases.

RESULTS

MMP2, 9, 11, 14, and 16 were upregulated in the conventional RCC in comparison with the chromophobe RCC, whereas MMP1, 11 and 16 were pronounced in papillary RCC. MMP9 transcript levels were strongly associated with the MMP9 enzymatic activity (p=0.001), and therefore, with disease-free survival (p=0.001) and metastasis (p=0.011). Gelatinolytic activity of MMP9 by zymography was strongly associated with MMP9 mRNA expression, which was more intense in 'conventional' RCC than in 'chromophobe' RCC (p=0.001), irrespective of tumor grade or stage. MMP9 was proven to be a significant prognostic predictor by multi-variate survival analysis (p=0.0054). MMP2 enzymatic activity disappeared in spite of its constant transcript expression in RCC.

CONCLUSIONS

MMP9 appears to be regulated at the transcript level, whereas MMP2 is regulated at the posttranscriptional level. Poor survival with a high frequency of metastases in 'conventional' RCC is associated with MMP9, which exhibits a high transcriptional level, and a high gelatinolytic activity. As a result, MMP9 may be a candidate of predictors of disease-free survival in RCC.

Effects of radiation on normal tissue: consequences and mechanisms

The use of radiation therapy to treat cancer inevitably involves exposure of normal tissues. As a result, patients may experience symptoms associated with damage to normal tissue during the course of therapy for a few weeks after therapy or months or years later. Symptoms may be due to cell death or wound healing initiated within irradiated tissue, and may be precipitated by exposure to further injury or trauma. Many factors contribute to risk and severity of normal tissue reactions; these factors are site specific and vary with time after treatment. Treatments that reduce the risk or severity of damage to normal tissue or that facilitate the healing of radiation injury are being developed. These could greatly improve the quality of life of patients treated for cancer.

Characterization of melanoma associated spongiform scleropathy

PURPOSE

Melanoma associated spongiform scleropathy (MASS) describes areas within the sclera where collagen bundles appear to have disintegrated into loose fibres. It is found adjacent to choroidal and ciliary body melanoma. This study aimed to characterize these changes histopathologically.

METHODS

Sections of 218 eyes that had been enucleated for malignant melanoma between January 1994 and June 2000 were examined for MASS, using data collected from the files of the Eye Pathology Institute, University of Copenhagen. Findings were correlated to patient characteristics (age, gender and pre-enucleation radiation) and tumour characteristics (location, morphology and invasion). Staining was applied using haematoxylin-eosin (HE), periodic acid-Schiff (PAS), haematoxylin-phloxine-saffron (HPS), alcian blue, colloidal iron and Masson's trichrome. Sixteen normal eyes and 29 eyes with diseases other than choroidal and ciliary body melanoma served as controls.

RESULTS

Melanoma associated spongiform scleropathy was observed in 73 of the 218 eyes (33%) with melanoma. No changes were found in normal eyes or in eyes with other intraocular diseases. A significantly higher incidence of MASS was found in older age groups. Thirty-six (49%) of the 73 cases of MASS were observed within a patient age range of 71-90 years, whereas only 14 cases (19%) were observed within an age range of 41-60 years. Pre-enucleation radiation significantly reduced the incidence of MASS. Twenty-two (10%) of the total 218 eyes had received pre-enucleation radiation and in only two (1%) of these was MASS observed. Melanoma associated spongiform scleropathy was found only in areas of contact between the tumour and the sclera, and the degree of MASS correlated directly with the extent of this contact. No significant correlation with tumour cell type was found.

CONCLUSIONS

In eyes with MASS, the severity of the changes correlated to the extent of direct contact between the tumour and sclera. Melanoma associated spongiform scleropathy showed a significant predilection towards older age groups. Pre-enucleation radiation significantly reduced the incidence of MASS. Melanoma associated spongiform scleropathy is probably caused by a deposition of amorphous material splitting the scleral collagen fibrils. This material may be secreted either directly from the adjacent tumour or from scleral fibroblasts stimulated by the tumour cells.

Putative role of 67 kDa elastin-laminin receptor in tumor invasion

Cellular regulatory mechanisms normally maintain a delicate balance between cell proliferation, quiescence and death. The imbalance between these functions resulting from molecular intracellular changes is a key factor in tumorigenesis. Tumor cells detaching from the primary tumor possess a propension for invasion and metastasis formation. These tumor cells can attach, migrate, proliferate and grow in host tissue. The surrounding extracellular matrix (ECM) modulates these functions. It is now widely accepted that cell-matrix interactions play an important role in these processes. Most investigators concentrated their attention on the role of integrins in the above processes. There are, however, only scant data on the role of elastin and its receptors in tumor invasion. Nevertheless, experimental evidence indicates that the 67 kDa elastin-laminin receptor (ELR) subunit plays an important role in tumor invasion by mediating essential tumor cell functions leading to metastases. In this review we will concentrate on the putative role of the 67 kDa ELR subunit in tumor invasion.

Parathyroid carcinomas: can clinical outcomes for parathyroid carcinomas be determined by histologic evaluation alone?

The Fifth Annual Meeting of the Japan Endocrine Pathology Society was held in September 2001. A highlight of the meeting was the participation of Japanese and American endocrine pathologists in a conference to consider the topic "The Determination of Clinical Outcomes for Parathyroid Carcinomas by Histological Evaluation of Invasive Growth." The discussion was centered around three cases of parathyroid carcinomas selected by the coordinator, Dr. Kameyama, and discussed by Drs. Ronald DeLellis, Ricardo Lloyd, and Kennichi Kakudo. In this article, we summarize their diagnoses and comments.

Up-regulation of urokinase-type plasminogen activator and its receptor correlates with enhanced invasion activity of human glioma cells mediated by transforming growth factor-alpha or basic fibroblast growth factor

Glioblastoma multiforme is a highly malignant tumor that is extremely refractory to therapy. One reason is its highly invasive nature into brain tissue. Metalloproteinases and their inhibitors, plasminogen activators (PA) and their inhibitors and cathepsins are thought to be involved in invasion by tumor cells. In this study, we determined if the urokinase-type plasminogen activator (uPA) and/or the urokinase-type plasminogen activator receptor (uPAR) were responsible for the invasion activity of a human glioma cell line. We determined the invasion activity of a human glioma U251 cell line using an in vitro invasion assay system. A 2.4- to 5.8-fold increase in invasion activity was observed in the presence of basic fibroblast growth factor (bFGF) or transforming growth factor (TGF)-alpha. Northern blot analysis showed that bFCF and TGF-alpha treatment was associated with increases in cellular mRNA levels of uPA and uPAR. Zymographic activity correlated to mRNA levels of uPA and uPAR. Addition of an anti-uPAR monoclonal antibody significantly inhibited the invasion activity induced by bFGF- and TGF-alpha. Irsogladine, an inhibitor of uPA synthesis, also blocked the invasion activity. These observations suggest that uPA and its receptor have a role in the invasion process of human gliomas.

Matrix metalloproteinases in tumor invasion and metastasis

Extensive work on the mechanisms of tumor invasion and metastasis has identified matrix metalloproteinases (MMPs) as key players in the events that underlie tumor dissemination. Studies using natural and synthetic MMP inhibitors, as well as tumor cells transfected with cDNAs encoding the MMPs characterized thus far have provided compelling evidence that MMP activity can induce or enhance tumor survival, invasion and metastasis. Because of the ability of MMPs to degrade extracellular matrix (ECM) proteins, the principal mechanism whereby MMPs promote tumor development has been thought to be the proteolytic breakdown of tissue barriers to invasion and the associated facilitation of circulating tumor cell extravasation. However, recent evidence stemming from the use of novel experimental approaches indicates that MMPs do not play a major role in the process of extravasation itself. Rather, they appear to promote intravasation (the process of penetrating the circulation following invasion of blood vessels) and regulate the relationship between tumor cells and host tissue stroma subsequent to extravasation. In addition, the discoveries that a growing number of proteolytically active MMPs may localize to the cell surface in association with adhesion receptors, and that MMP substrates include latent cytokines and growth factors, provide a new conceptual framework for the mechanisms whereby MMPs influence tumor behavior.

A novel model for invasion of cancer cells using the submucosal layer of the human stomach

An in vitro model for studying the invasion mechanism of cancer cells was established using the submucosal layer of the human stomach. Submucosa prepared from a surgical specimen was maintained in an organ culture. The cytoarchitecture of the cultured submucosa remained well preserved; viability remained for over 2 weeks. When human gastric cancer cell lines MKN45, MKN74, and Kato III were seeded onto the submucosal slices, cancer cells of MKN45 and KATO III invaded the submucosa 3 days after inoculation. However, MKN74 cells were not seen in the submucosal slices. Our invasion model, which mimics the in vivo conditions of the submucosa of human stomach, may make it possible to analyze actual events of human gastrointestinal malignant cell invasion in normal submucosa in vitro. The usefulness of our invasion model lies in the choice of the submucosal layer of the human stomach as the host tissue. The histarchitecture of the submucosal slices indicates that the model has potential for studies of the mechanism of interactions between carcinoma cells and host tissue similar to interactions that may occur in vivo. Moreover, this method allows the continuous microscopic observation of cells within the living submucosa. Using this model, a novel approach to controlling the local invasion of tumor cells may lead to a promising, radical cure for these intractable neoplasms. Our model system is an in vitro model that is facile, inexpensive, and experimentally manipulative.

Phase I and pharmacologic study of the specific matrix metalloproteinase inhibitor BAY 12-9566 on a protracted oral daily dosing schedule in patients with solid malignancies

PURPOSE

To evaluate the feasibility of administering BAY 12-9566, a matrix metalloproteinase (MMP) inhibitor with relative specificity against MMP-2, MMP-3, and MMP-9, on a protracted oral daily dosing schedule in patients with advanced solid malignancies. The study also sought to determine the principal toxicities of BAY 12-9566, whether plasma BAY 12-9566 steady state concentrations (C(ss)) of biologic relevance could be sustained for prolonged periods, and whether BAY 12-9566 affected plasma concentrations of MMP-2, MMP-9, and tissue inhibitor of MMP-2 (TIMP-2).

PATIENTS AND METHODS

Patients with solid malignancies were treated with BAY 12-9566 at daily oral doses ranging from 100 to 1,600 mg. BAY 12-9566 dose schedules included 100 mg once daily, 400 mg once daily, 400 mg twice daily, 400 mg three times daily, 400 mg four times daily, and 800 mg twice daily. Plasma was collected to study the range of BAY 12-9566 C(ss) values achieved, and exploratory studies were performed to assess the effects of BAY 12-9566 on plasma concentrations of MMP-2, MMP-9, and TIMP-2.

RESULTS

Twenty-one patients were treated with 47 28-day courses of BAY 12-9566. The most common side effects were headache, nausea, vomiting, abnormalities in hepatic functions, and thrombocytopenia, which were rarely clinically significant. BAY 12-9566 was well tolerated on all dose schedules, and there was no consistent dose-limiting toxicity that precluded treatment in the range of dose schedules evaluated. Instead, dose escalation was terminated because BAY 12-9566 plasma C(ss) values increased less than proportionately and plateaued as the daily dose was increased within the dose range of 100 to 1,600 mg/d, suggesting saturable drug absorption. Mean plasma C(ss) values achieved with all dose schedules exceeded BAY 12-9566 concentrations required to inhibit MMPs in vitro and in vascular invasion and tumor proliferation in vivo models. There were no consistent effects of BAY 12-9566 on the plasma concentrations of MMP-2 and MMP-9 over the continuous dosing period at any dose schedule level. However, plasma levels of TIMP-2 seemed to increase in a dose-dependent manner (r(2) =.50, P =.046).

CONCLUSIONS

The recommended dose of BAY 12-9566 for subsequent disease directed studies is 800 mg twice daily, which resulted in biologically relevant plasma C(ss) values and an acceptable toxicity profile. Although exploratory studies of MMPs in plasma were not revealing, it is conceivable that some tumor types and disease settings are more likely to produce more readily quantifiable levels of activated MMPs than others. Therefore, attempts to identify and quantify surrogate markers of MMP inhibitory effects should continue to be performed in disease-directed studies in more homogenous patient populations.

Alterative expression of the collagenase and adhesion molecules in the highly metastatic clones of human colonic cancer cell lines

Human colonic carcinoma cell lines, KM12C, KM12SM and KM12L4, were previously established and their in vivo metastatic potentials have been well evaluated. The highly metastatic cell lines KM12SM and KM12L4 were derived from the parental low metastatic cell line KM12C in vivo. To evaluate the metastatic behavior of these cell lines in vitro, we examined colony formation on monolayers of the pulmonary arterial endothelial (CPAE) cells. On day 4, the highly metastatic cell lines showed an approximately 2-fold increase in number of colonies on CPAE cell monolayers relative to the parental KM12C cell line. To investigate what evidence is correlated with their metastatic and invasive abilities, Northern blot analysis and flow cytometry were performed in all cell lines. According to the results of Northern blot analysis, the levels of matrix metalloproteinase (MMP)-2 and c-met mRNA expression were increased in highly metastatic cell lines as compared with the parental cell line. We also examined the cell-surface expression of several adhesion molecules by flow cytometry. The levels of expression of sialyl Lewisa antigen (sLe(a)) in KM12SM and KM12L4 were twice higher than that in KM12C. However, the levels of expression of E-cadherin in KM12SM and KM12L4 were decreased to half that in KM12C. The alterative expression of the collagenase and adhesion molecules might contribute to their metastatic/invasive abilities of these cell lines both in vivo and in vitro.

Expression of alpha 2 macroglobulin receptor/low density lipoprotein receptor-related protein is cell culture density-dependent in human breast cancer cell line BT-20

alpha 2Macroglobulin receptor/low density lipoprotein receptor-related protein (alpha 2MR/LRP) is a multifunctional cell plasma membrane receptor that binds and facilitates the endocytosis of a number of ligands involved in protease regulation and lipoprotein metabolism. In the invasive breast cancer cell line BT-20 we show that the expression of alpha 2MR/LRP can be strongly affected by cell culture density. By comparing measurements of mRNA, total cellular alpha 2MR/LRP antigen, and cell surface alpha 2MR/LRP expression we have demonstrated a marked cell density-dependent regulation of this receptor expression. Increasing the cell density results in a 3.4-fold increase in cell surface alpha 2MR/LRP expression. This corresponds to a marked increase in alpha 2MR/LRP mRNA in Northern blots of total RNA from cells cultured at high density and to consistent increases in alpha 2MR/LRP heavy chain in Western blots of cell lysates from high density cultures. These studies together demonstrate the significant up-regulation of alpha 2MR/LRP expression in BT-20 by increased cell density.

Suppression of basement membrane type IV collagen degradation and cell invasion in human melanoma cells expressing an antisense RNA for MMP-1

During progression from benign nevus to vertical growth phase melanoma, melanocytes acquire the ability to invade into the dermis. This process requires rupture of the basal lamina and dissolution of dermal type I collagen. Metastases-derived human melanoma MIM cells have an invasive ability in vitro which is dependent on metalloproteinases. In the present study we analysed the role of type I collagenase (MMP-1) in melanoma invasion using MIM cells in which the constitutive expression of MMP-1 was suppressed by stable transfection with a plasmid vector expressing a 777 bp antisense fragment of MMP-1 genomic DNA. Two clones were isolated in which MMP-1 mRNA expression was blocked by 90-96% with a corresponding loss in protein synthesis. In their morphological appearance and growth rate in vitro these cells were indistinguishable from wild type cells or control cells transfected with the same vector expressing the MMP-1 fragment in the sense orientation. Their mRNA and protein levels for type IV collagenase (MMP-2) were unchanged as assessed by Northern and Western blot analyses and by gelatin zymography. However, when the invasive ability of the cells was measured, we found that in addition to type I collagen, invasion through type IV collagen and a reconstituted, type IV collagen-containing basement membrane (Matrigel) were also significantly inhibited as compared to normal or sense-transfected cells. The results indicate that despite the presence of functional MMP-2, degradation of type IV collagen matrices by the melanoma cells was dependent on expression of MMP-1.

Tumor neutrophil elastase is closely associated with the direct extension of non-small cell lung cancer into the aorta

OBJECTIVE

Neutrophil elastase (NE) is the only neutral protease that is able to degrade insoluble elastin and other extracellular matrix constituents, and thus, may be involved in tumor invasion and metastasis. Using a highly specific and sensitive enzyme immunoassay (EIA), we recently demonstrated that immunoreactive (ir)-NE is produced by non-small cell lung cancer cell lines. We have measured the ir-NE concentration in non-small cell lung cancer tumor extracts and have evaluated its association with disease stage.

METHODS

We measured the ir-NE concentration in 144 non-small cell lung cancer tumor extracts using EIA, which permits the rapid measurement of both the free and alpha1-protease inhibitor (alpha1-PI) complexed form of ir-NE. In 15 clinical T4 (cT4) patients, we also determined the concentration of free ir-NE in tumor extracts using a kit that detects only NE complexed with alpha1-PI and subtracting that value from the total NE concentration.

RESULTS

ir-NE was detected in tumor extracts from 115 of 144 patients, ranging from 0.21 to 23.35 microg/100 mg protein. When the 144 specimens were grouped according to the clinical stage of disease, the ir-NE concentration (mean+/-SE) was significantly higher in those with cT4 disease (n=15; 7.90+/-1.88 microg/100 mg protein) than in those with cT1 (n=29; 1.27+/-0.27; p<0.001), cT2 (n=64; 1.18+/-0.17; p<0.001), or cT3 disease (n=26; 1.99+/-0.38; p<0.003). There was no significant association between the ir-NE concentration and cN-factor or any other clinical features. When the ir-NE concentration in the tumor extracts of the cT4 patients was compared with respect to the tumor invasion sites, the ir-NE level was significantly higher in those with surgical T4 (sT4) disease with aortic invasion (n=4; 17.4+/-3.10) than in those who were down-staged postoperatively (n=5; 4.9+/-1.33; p=0.005) or those with sT4 disease with involvement of other sites (n=6; 4.07+/-1.83; p=0.004). Similar results were observed for the free form of ir-NE.

CONCLUSIONS

These data suggest that NE may be involved in tumor progression of non-small cell lung cancer. Since the aorta is one of the richest sources of polymeric and insoluble elastin, this enzyme may play an active role in the direct extension of the tumor into the aorta.

Hyaluronidase activity in gynaecological cancer tissues with different metastatic forms

We investigated hyaluronidase activity in gynaecological normal and malignant tissues. Hyaluronidase activity in culture medium of tissue specimens was detected by hyaluronic acid zymography and quantified by densitometry. Hyaluronidase activity was shown as one dominant band (molecular weight 65 kDa) at pH 3.5. Hyaluronidase activity was significantly higher in normal ovary (P < 0.05) and normal endometrium (P< 0.05) than in normal cervix. One dominant 65-kDa hyaluronidase was expressed in 100% (14 out of 14) of ovarian cancer tissues and in 91% (10 out of 11) of endometrial cancer tissues. However, hyaluronidase activity was not observed in cervical cancer tissues. Hyaluronidase activity was significantly higher in ovarian (P < 0.001) and endometrial (P < 0.01) cancer tissues than in cervical cancer tissue and was significantly higher in ovarian cancer tissue than in endometrial cancer tissue (P < 0.05). These facts suggest that the cancer cells make use of the original characteristic of the organ to invade and metastasize. Moreover, these results reflect the difference in metastatic forms and are suggestive of a strong relationship between hyaluronidase activity and invasion and metastasis of ovarian and endometrial cancers compared with cervical cancer.

Immunohistochemical expression of SKALP/elafin in squamous cell carcinoma of the oesophagus

In this study, the immunohistochemical expression of a new inducible elastase inhibitor, SKALP (skin-derived anti-leucoproteinase)/elafin, in the tissue of squamous cell carcinoma and uninvolved oesophageal mucosa was studied using a polyclonal rabbit anti-serum against SKALP/elafin. The results were compared with the immunohistochemical staining of proliferating cell nuclear antigen (PCNA) and the TUNEL assay in serial sections. In non-malignant oesophageal mucosa, the expression of SKALP/elafin was localized in the cells of the stratified zone overlying the PCNA-positive basal zone. In oesophageal cancer, the incidence of the expression was significantly related to the degree of the differentiation of the tumour. Characteristically, the expression was almost limited in tumour cell nests that had a clear squamous phenotype. In tumour cell nests, the expression of SKALP/elafin was localized in the cells overlying PCNA-expressing cells and no expression was found in the cells that expressed PCNA; DNA fragmentation was often observed in the same cell layers as those in which SKALP/elafin immunoreactivity was found. This enzyme inhibitor is speculated to be involved in the induction of the cell differentiation and apoptosis of human squamous cell carcinoma cells of the oesophagus.

Extended culturing of androgen-responsive human primary epithelial prostate cell isolates by continuous treatment with interstitial collagenase

Continuous culturing of two distinct human prostate specimens in the presence of interstitial collagenase added directly to conventional medium resulted in the isolation and extended growth of primary epithelial prostate cell (PEPC) cultures from each. Both continued to proliferate substantially beyond the average time determined for analogous untreated epithelial prostate isolates. Both repeatedly stain positive for keratin and are characteristically epithelial in morphological appearance and growth model. Both express androgen receptor mRNA and stain positive for androgen receptors. PEPC-2 displays an androgen dose-dependent stimulation of cell proliferation, as well as specifically binding 3H-R1881. PEPC-1 exhibits a hypotetraploid karyotype with loss of the Y chromosome. PEPC-2 conserves a normal human ploidy, including the Y chromosome, although there is extensive random chromosome loss. Elimination of the collagenase from the medium resulted in decreased cellular proliferation and accumulation of stainable collagen in both PEPC cultures. Neither PEPC isolate produced tumors in male nude mice, whether injected alone, mixed with matrigel, or combined with prostate or bone fibroblastic cells.

An in vitro invasion model for human renal cell carcinoma cell lines mimicking their metastatic abilities

We developed a modified in vitro invasion assay system using monolayers of vascular endothelial cells. A type I collagen gel was formed in plastic dishes, and overlaid with type IV collagen. Calf pulmonary arterial endothelial (CPAE) cells were seeded onto these plates, and incubated until they reached confluence. Five human renal cell carcinoma cell lines with various metastatic potentials in vivo were then seeded on the monolayer CPAE cells, and their colony formation and invasion activities were examined for 9 days. At day 4, the highly metastatic cell lines increased the number of colony foci on monolayer CPAE cells several fold higher than their poorly metastatic counterpart. The horizontal spreading patterns were also different between poorly and highly metastatic cell lines. On day 9, the number of carcinoma foci that penetrated the monolayer of CPAE cells and type IV collagen sheets into type I collagen gels in highly metastatic cell lines greatly increased as compared with that of poorly metastatic cell lines. Our in vitro invasion assay using monolayer CPAE cells would be useful to evaluate protease activities and colony formation during invasion.

Identification of arachidonic acid pathways required for the invasive and metastatic activity of malignant tumor cells

Metastasis is a complex process, almost a cascade, involving multiple steps and activities. However, an important factor is that malignant cells are able to penetrate through the multiple basement membrane barriers surrounding tissues, blood vessels, nerves and muscle that would otherwise block their dissemination. Penetration of malignant tumor cells through basement membrane is an active process requiring proteolysis. We report here that inhibitors of both the cyclooxygenase and lipoxygenase pathways of arachidonic acid metabolism convert mouse melanoma and human fibrosarcoma cells to a non invasive state by reducing the production of MMP-2, an enzyme required for the degradation of basement membranes. Specific metabolites of each pathway, i.e. PGF2 alpha and 5-HPETE, are able to transcend the block and restore collagenase production, invasiveness in vitro and metastatic activity in vivo. These studies indicate a key role for arachidonic acid metabolites in metastasis and suggest novel therapeutic approaches for inhibiting the spread of cancer.

Expression of MMP-1 in the capsule of thyroid cancer--relationship with invasiveness

To investigate the invasive activity of thyroid cancer, an in situ hybridization study was carried out in 19 thyroid tumors, including nine papillary carcinomas, five follicular carcinomas and five follicular adenomas, by using a 35S-labeled MMP-1 (matrix metalloproteinase-1) cDNA probe. The MMP-1 gene was expressed not in the cancer cells but in the fibrous capsules of papillary carcinoma. Thyroid cancer is generally circumscribed by a fibrous capsule. We found that types I and III collagen constitute the fibrous capsule, and that the MMP-1 gene was expressed in the outer border of these sites. These findings suggest that MMP-1 plays an important role in the invasion of thyroid cancer.

Expression of integrin alpha 3 in gastric and colorectal cancers: its relation to wall contraction and mode of invasion

We macroscopically classified 25 gastric and 23 colorectal advanced cancers into "contracted" and "uncontracted" types, and found immunohistochemically that integrin subunit alpha 3 was more frequently expressed in the extracellular matrix (ECM) in the former than in the latter (75%:9/12 vs. 38%: 5/13 in gastric and 86%:6/7 vs. 25%:4/16 in colorectal cancers, respectively). Integrin subunit alpha 3 was also expressed more frequently in cancers producing transforming growth factor-beta (TGF-beta), which is related to ECM deposition, integrin expression and cell mobility, than in those which did not produce TGF-beta (67%:10/15 vs. 40%:4/10 in gastric and 57%:4/7 vs. 38%:6/16 in colorectal cancers, respectively). In addition, integrin subunit alpha 3 was not expressed in 2 benign gastric ulcers combined with gastric cancer elsewhere in the stomach. On the other hand, a retrospective analysis of 107 cases of rectal cancer which recurred after a curative operation revealed that local recurrence was more frequent in "contracted" than "uncontracted" types (44%:11/25 vs. 26%:21/82). These results may suggest that the abundant interstitial fibrosis which leads to remarkable gastric or colorectal wall contraction is a result of the interaction between cancer cells and ECM, along with the expression of integrin and/or the production of TGF-beta. This fibrosis may also be closely related to the mode of gastric and colorectal cancer invasion.

Biology of human colon cancer metastasis

The process of metastasis is highly selective and favors the survival and growth of a few subpopulations of cells that preexist within a heterogeneous primary neoplasm. To produce metastases, tumor cells must succeed in invasion, embolization, survival in the circulation, arrest in a distant capillary bed, and extravasation into and multiplication in organ parenchyma. The outcome of this process depends on the interaction of metastatic cells with multiple host factors. To assess metastatic potential accurately, it is necessary to orthotopically implant human tumor cells recovered from surgical specimens into nude mice. This orthotopic implantation of tumor cells is invariably associated with trauma to the specific organ of implantation, which is followed by the processes of inflammation and repair. Tissue-specific growth factors may be responsible for stimulation of tumor cells that possess specific surface receptors. Understanding the factors that regulate cancer metastasis should allow for the design of rational therapy.

Stimulation and regulation of tumor cell motility in invasion and metastasis

In this review, the role of extracellular factors in the stimulation and regulation of tumor cell motility are discussed. Tumor cells respond in a motile fashion to a variety of external ligands including autocrine motility factors, growth factors, and components of the extracellular matrix. Since tumor cell motility is a necessary component of tumor invasion and metastasis, we speculate that these protein factors could play important regulatory roles in tumor motility at different stages of the metastatic cascade.

Effects of mast cell-macrophage interactions on the production of collagenolytic enzymes by metastatic tumor cells and tumor-derived and stromal fibroblasts

Histological examination of the metastatic rat mammary adenocarcinoma line MTLn3 showed that macrophages and mast cells were frequently localized at the tumor periphery in the stromal tissues adjacent to the zones of tumor invasion. The interactions of these host cells with tumor cells and tumor-associated fibroblasts could be important in stimulating the production of extracellular matrix-degrading enzymes that facilitate tumor invasion and metastatic spread. Therefore, we examined the effects of isolated, activated macrophages and mast cells on the secretion of collagenolytic activities by normal fibroblasts, metastatic mammary adenocarcinoma cells and tumor-associated fibroblasts. Medium from activated macrophages or degranulated mast cells stimulated significant increases in production of collagenolytic activities by normal and tumor-associated fibroblasts and MTLn3 tumor cells. Medium from activated macrophages that had been pretreated with medium from degranulated mast cells, however, were less stimulatory to fibroblasts and tumor cell production of collagenolytic activities than medium from degranulated mast cells alone. We also examined the effects of two cytokines, interleukin-1 alpha and tumor necrosis factor-alpha on activated macrophage- and degranulated mast cell-stimulation of fibroblast and tumor cell collagenolytic activities. The two cytokines alone or in combination stimulated increased production of collagenolytic activities by fibroblasts and tumor cells. Addition of the cytokines to degranulated mast cell products resulted in secretion of higher collagenolytic enzyme activities by normal fibroblasts (but not by tumor-derived fibroblasts or tumor cells) than with degranulated mast cell product-treatment of either target cell alone. Cytokines used in combination with macrophage-conditioned medium were less effective in stimulating fibroblast and tumor cell collagenase activities than cytokines alone. Thus normal infiltrating host cells such as macrophages and mast cells can have profound effects on the production of degradative enzymes by tumor cells and tumor-associated stromal fibroblasts.

Gene expression of interstitial collagenase (matrix metalloproteinase 1) in gastrointestinal tract cancers

Collagenolytic proteinases play an important pathological role in the invasion and metastasis of cancer cells. However, little is known about the role of interstitial collagenase (matrix metalloproteinase-1; MMP-1) in this process. To investigate the expression of the MMP-1 gene in cancer tissues, an in situ hybridization study was carried out in gastrointestinal tract cancers (one esophageal cancer, five gastric cancers, and four colorectal cancers), using a 35S-labeled MMP-1 cDNA probe. The MMP-1 gene was expressed in the stromal cells of fibrous tissue around cancer nests, especially at the margin of invasion and/or within the cancer nest; however, no definite expression within cancer cells was observed. Expression of the MMP-1 gene in the stromal cells was more common in well differentiated gastric adenocarcinoma than in poorly differentiated adenocarcinomas. These findings indicate that expression of the MMP-1 gene is greater in stromal cells that are closely associated with cancer cells, suggesting a pathophysiological role of MMP-1 in the invasion and metastasis of cancer cells.

Distribution of gelatinase B (MMP-9) and type IV collagen in colorectal carcinoma

Gelatinase B (92 kD, matrix metalloproteinase-9, MMP-9), an enzyme capable of degrading several connective tissue components, was demonstrated by immunolocalization in all specimens of colorectal carcinoma (n = 40), but its distribution between specimens was variable. MMP-9 expression was more frequently observed in advanced tumour stages and was especially prevalent at the side and deep margins of the tumours, and ulceration sites. MMP-9 staining was observed for transformed epithelial cells, macrophages and neutrophils, but seldom for vascular or stromal cells. By contrast, the enzyme was absent from epithelial cells of normal mucosal tissue. Immunostaining of type IV collagen, the major structural component of basement membranes, revealed a general depletion or loss of these structures both within the tumours and at the tumour margins. Dual immunolocalization of MMP-9 and type IV collagen demonstrated that MMP-9 expression at specific sites in the tumour was often inversely related to the distribution of type IV collagen. MMP-9 expression was most pronounced at the invasive tumour margins and in microfoci where tumour cells were in close proximity to inflammatory cells. Such observations support the concept that localized proteolytic and collagenolytic activities contribute to the invasive properties of colorectal tumours.

Expression of 72 kDa type IV collagenase and invasion activity of human glioma cells

Metalloproteinases, inhibitors of metalloproteinases, plasminogen activators, inhibitors of plasminogen activators and cathepsins are thought to be involved in invasion by tumor cells. Glioblastoma multiforme is highly malignant and extremely refractory to therapy. One reason is because of its highly invasive nature within the nervous system. However, it remains unclear how invasion/dissemination of glioblastoma multiforme proceeds. In this study, we attempted to determine which proteinases were responsible for the invasion activity of human glioma cell lines in vitro. Nine human glioma cell lines (NHG1, NHG2, IN157, IN301, IN500, U251, U343, T98G and CCF-STTG1) derived from patients with glioma were grown in culture and used. We compared the invasion activity of glioma cell lines in a Matrigel invasion assay system, and formulated the activity as invasion index (%). Among the nine cell lines, IN157, IN500 and U343 showed less than 10% invasion activity (low group); NHGI, IN301 and CCF-STTG1 showed 10-25% activity (intermediate group); NHG2, U251 and T98G showed more than 30% activity (high group). Addition of an inhibitor of metalloproteinases, TIMP-1, to the assay system was found to significantly inhibit invasion activity of T98G cells (P < 0.01). Northern blot analysis demonstrated expression of urokinase-type plasminogen activator (uPA), tissue-type PA (tPA) and PA inhibitor-1 (PAI-1) in some of the above cell lines. Cellular levels of PAs and their inhibitor mRNA, however, appeared not to be correlated with invasion activity in most glioma cell lines except for CCF-STTG1. Expression of 72 kDa type IV collagenase (MMP-2) was much lower in IN157, IN500 and U343 than other cell lines, whereas expression of TIMP-1 was much higher in IN500 than in other cell lines. Zymographic activity was found to be comparable to MMP-2 mRNA levels in all cell lines except for CCF-STTG1. Type IV collagenolytic activity was also comparable to invasion activity in nine cell lines. These observations suggest the role of type IV collagenase and its inhibitors in determining capacity for invasion by human gliomas. However, a comprehensive analysis both in vitro and in vivo is required to confirm the role for this enzyme in glioma cell invasiveness.

Localization by in situ hybridization of mRNAs encoding stromelysin 3 and tissue inhibitors of metallo-proteinases TIMP-1 and TIMP-2 in human head and neck carcinomas

The presence and distribution of mRNAs encoding a matrix metalloproteinase (MMP) stromelysin 3 and two tissue inhibitors of MMP, TIMP1 and TIMP-2 have been studied by in situ hybridization of 18 human epidermoid head and neck carcinomas and four normal tissues. We found that in 16 tumors out of 18, stromelysin 3 mRNAs were only expressed by fibroblasts which were in close contact to invasive cancer cells. Tumor cells and normal tissues were not labeled. TIMP-1 mRNAs were detected in well differentiated cancer cells and in endothelial cells in all the cancers. In 13 out of the 18 carcinomas, TIMP-2 mRNAs were localized in only a few stromal cells near well differentiated invasive cancer cells and in endothelial cells. The significant expression of TIMP-1 and TIMP-2 mRNAS may lead to less aggressive MMPs, especially in the case of stromelysin 3, in the invasive process of the stroma.

Metalloproteinase and TIMP expression by the human breast carcinoma cell line 8701-BC

It is widely accepted that collagenolytic enzymes are required to facilitate the invasion and spread of tumour cells into host tissues. Immunohistochemical, zymographic and PCR analyses have produced evidence that the recently established human mammary carcinoma cell line, 8701-BC, expresses several metalloproteinases (MMP-1, -2, -9 and -10) and their tissue inhibitors (TIMP-1 and -2). Application of these different techniques has led to several observations, both complementary and dissimilar. Whereas PCR analysis showed that mRNA was detected for each of the proteins, the immunolocalization study demonstrated that MMP-1, MMP-2, MMP-9 and TIMP-1 production was restricted to only a proportion of the tumour cells, with no evidence of MMP-3 or TIMP-2 synthesis. Such observations suggested phenotypic heterogeneity within the cell line, which was further examined by use of the tumour cell clones BC-3A and BC-61 derived from the parental 8701-BC line. Comparative studies using zymography and PCR analysis demonstrated differences in MMP-2 and MMP-10 expression between the 3 cultures. The data indicate that the 8701-BC cell line retains an inherent capacity for metalloproteinase and TIMP expression, with the production of both interstitial collagenase (MMP-1) and the 2 basement-membrane-degrading enzymes (MMP-2 and MMP-9) representing an aggressive collagenolytic phenotype. The concomitant production of TIMP-1 by these cell cultures, and the apparent phenotypic heterogeneity displayed by these lines, suggest that metalloproteinase dysregulation may represent an important feature of clonal heterogeneity. Although the 8701-BC and BC-61 cells were much more invasive than those of the BC-3A clone, as judged by the penetration of "Matrigel", it has not yet been possible to relate this invasive potential to the metalloproteinase and TIMP profiles reported here for each cell line.

Production of matrix metalloproteinase-2 and metalloproteinase-3 related to malignant behavior of esophageal carcinoma. A clinicopathologic study

BACKGROUND

Matrix metalloproteinases (MMP) are a gene family of zinc enzymes capable of degrading almost all of the extracellular matrix macromolecules in vivo. Their enzymic activities are believed to be responsible for tumor invasion and metastasis.

METHODS

In this study, using peroxidase-antiperoxidase method, monospecific antisera against MMP-1 (tissue collagenase), MMP-2 (type IV collagenase/72-kilodalton [KD] gelatinase), and MMP-3 (stromelysin) were applied to 29 squamous cell carcinomas and normal epithelium of the esophagus to identify cells synthesizing and secreting these enzymes.

RESULTS

Immunoreactivity of MMP-1, -2, and -3 was observed in small cancer nests of the deeply invasive or marginal portion of the tumor. Among the 29 patients studied, the presence of at least one MMP was observed in 17 (58.6%). All three enzymes were observed in six (20.6%) patients, MMP-2 and -3 in five (17.2%) patients, only MMP-2 in three (10.3%) patients, and MMP-3 alone in three (10.3%) patients. There was a good correlation among histologic stage and tumor invasion, lymph node metastasis, and MMP expression. In particular, expression of MMP-2 and -3 was closely related to lymph node metastasis and vascular invasion.

CONCLUSIONS

These results suggest that MMP, especially MMP-2 and -3, play an important role in tumor invasion and metastasis and that analysis of MMP-2 and -3 production is useful for evaluation of malignant potential in esophageal carcinoma.

Malignant cell-specific gelatinase activity in human endometrial carcinoma

BACKGROUND

The protease activity leading to degradation of the extracellular matrix was compared between human endometrial cancer and normal uterine endometrium.

METHODS

Conditioned medium from tumor cells and normal endometrial cells was subjected to electrophoresis on sodium dodecyl sulfate (SDS)-polyacrylamide gel containing gelatin as a substrate. After electrophoresis, the gel was stained with Coomassie blue, and then the enzyme activity, expressed as the zone of dye clearing, was analyzed by densitometry.

RESULTS

Densitometric analysis showed that all the endometrial cancers expressed a very high molecular weight enzyme activity (Mr 220,000), which was not detected in medium from normal endometrial cells. The analysis also showed that in endometrial cancer the activity of a Mr 92,000 enzyme was always superior to that of a Mr 64,000 enzyme, which was in contrast to the situation for normal endometrium.

CONCLUSIONS

These results indicate that the expression of Mr 220,000 enzyme activity and the higher activity of the Mr 92,000 enzyme than the Mr 64,000 enzyme are involved in the malignant phenotype of native endometrial cancer.

Comparison of extracellular matrix antigens in subtypes of bronchioloalveolar carcinoma and conventional pulmonary adenocarcinoma. An immunohistochemical study

In contrast to the conventional pulmonary adenocarcinomas (CPAs), bronchioloalveolar carcinoma (BAC) grows predominantly by spreading along the existing alveolar septal framework. Within the BAC category, three subtypes have been identified: mucinous, nonmucinous, and sclerosing BAC. Of these, mucinous and sclerosing BACs have worse prognoses compared with nonmucinous BAC. However, the manifestation of aggressive behavior is different between the mucinous and sclerosing types of BACs. Multifocality is often produced by aerogenous spread, especially in the case of mucinous BACs. To study the differences between the BAC subtypes and the conventional pulmonary adenocarcinomas, we employed a battery of immunohistochemical stains marking the extracellular matrix architecture (laminin, collagen IV, fibronectin, and collagen III), a degradative enzyme against a basement membrane component (anti-type IV collagenase) and cellular receptors for laminin and collagen IV (alpha 2 integrin) on 16 BACs (5 mucinous, 5 nonmucinous, and 6 sclerosing) and 30 CPAs. The mucinous and nonmucinous BACs demonstrated neoplastic epithelial cells growing along a continuous basement membrane. A similar growth pattern with intact basement membrane was noted in the periphery of sclerosing BACs. However, in contrast to mucinous and nonmucinous BACs, all cases of sclerosing BACs showed disruption or complete absence of basement membrane components (laminin and collagen IV) around the embedded glands located centrally in the sclerotic fibrous stroma, as was seen in the basement membrane analysis of conventional adenocarcinomas. Furthermore, increased type IV collagenase activity was seen in the small centrally located embedded glands in comparison to the peripheral glands. These architectural alterations of basement membrane disruption and phenotypic expression of degradative activity may be a reflection of the invasive behavior of the sclerosing BACs and their tendency to produce lymph node metastasis. Although the mucinous BACs did not show evidence of basement membrane disruption, there was a marked increase in their levels of type IV collagenase expression along with consistently low levels of alpha 2 integrin receptor (laminin and collagen IV receptor) expression. These findings may be related to the ability of the mucinous BACs to detach from the underlying basement membrane and spread aerogenously, and is to be contrasted with the stromal infiltration and desmoplasia of sclerosing BACs and CPAs.

Expression of gelatinase/type IV collagenase in tumor necrosis correlates with cell detachment and tumor invasion

We have previously observed that acellular extracts from necrotic areas (NE) of the non-metastatic murine mammary adenocarcinoma M3, enhance in vitro cell detachment and spontaneous lung metastases. In the present study, using different proteinase inhibitors along with NE, only the calcium chelator EDTA could significantly abrogate the enhanced cell detachment from M3 produced by NE. The typical cleavage products of type IV collagenase were detected inside the tumor necrotic area, mainly in association with necrobiotic cells, as evaluated by Western blot analysis and immunohistochemical assays. Zymography revealed the presence of 72- and 92-kDa gelatinase/type IV collagenase in NE. Moreover, NE increased the in vitro invasive ability of cultured M3 cells. The use of specific antibodies against both 72- and 92-kDa type IV collagenases in the invasion assay showed that only the latter was able to revert the enhanced invasiveness to the baseline. It can be concluded that tumor necrosis is an important source of gelatinase/type IV collagenase, mainly in its 92 kDa form, and plays a major role in tumor invasion.