Tumor tissue concentrations of the proteinase inhibitors tissue inhibitor of metalloproteinases-1 (TIMP-1) and plasminogen activator inhibitor type 1 (PAI-1) are complementary in determining prognosis in primary breast cancer

Functional Relationship and Gene Ontology Classification of Breast Cancer Biomarkers

Breast cancer is a complex disease that still imposes a significant healthcare burden on women worldwide. The etiology of breast cancer is not known but significant advances have been made in the area of early detection and treatment. The advent of advanced molecular biology techniques, mapping of the human genome and availability of high throughput genomic and proteomic strategies opens up new opportunities and will potentially lead to the discovery of novel biomarkers for early detection and prognostication of breast cancer. Currently, many biomarkers, particularly the hormonal and epidermal growth factor receptors, are being utilized for breast cancer prognosis. Unfortunately, none of the biomarkers in use have sufficient diagnostic, prognostic and/or predictive power across all categories and stages of breast cancer. It is recognized that more useful information can be generated if tumors are interrogated with multiple markers. But choosing the right combination of biomarkers is challenging, because 1) multiple pathways are involved, 2) up to 62 genes and their protein products are potentially involved in breast cancer-related mechanisms and 3) the more markers evaluated, the more the time and cost involved. This review summarizes the current literature on selected biomarkers for breast cancer, discusses the functional relationships, and groups the selected genes based on a Gene Ontology™ classification.

Clinical Significance of Serum IL-12 Level in Patients with Early Breast Carcinoma and Its Correlation with Other Tumor Markers

AIM:

To investigate the diagnostic significance of Interleukin 12 (IL-12) in breast cancer (BC) and its correlation with other tumor markers including cancer antigen 15-3 (CA 15-3), carcinoembryonic antigen (CEA), matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinases-1 (TIMP-1), and MMP9/TIMP1 ratio.

METHODS:

Serum levels of IL-12, tumor markers, and hormone receptors were measured in 92 BC and 56 benign lesion patients versus 40 healthy subjects. Clinical stage, tumor size, lymph node metastasis, grade, and histological type were recorded.

RESULTS:

BC patients have lower IL-12, but higher CA 15.3 and CEA than control group. High levels of serum IL-12 were associated with lymph node positivity and progesterone receptor negativity. IL-12 was significant lower in invasive ductal carcinoma (IDC) compared to non IDC histological type. IL-12 was higher in patients with higher stage and grade but the difference was not statistically significant. IL-12 correlates negatively with MMP9/TIMP1 ratio.

CONCLUSION:

IL-12 is less specific than CEA for screening early BC, but its correlation with tumor aggressiveness and progression markers may have a prognostic value.

Valproic acid modulates radiation-enhanced matrix metalloproteinase activity and invasion of breast cancer cells

PURPOSE

To evaluate matrix metalloproteinase (MMP) activity and invasion after ionizing radiation (IR) exposure and to determine whether MMP could be epigenetically modulated by histone deacetylase (HDAC) inhibition.

MATERIAL AND METHODS

Two human breast cancer cell lines (MDA-MB-231 and MCF-7) were cultured in monolayer (2D) and in laminin-rich extracellular matrix (3D). Invasion capability, collagenolytic and gelatinolytic activity, MMP and TIMP protein and mRNA expression and clonogenic survival were analyzed after IR exposure, with and without a HDAC inhibition treatment [1.5 mM valproic acid (VA) or 1 μM trichostatin-A (TSA)].

RESULTS

IR exposure resulted in cell line-dependent stimulation of invasion capacity. In contrast to MCF-7 cells, irradiated MDA-MB-231 showed significantly enhanced mRNA expression of mmp-1, mmp-3 and mmp-13 and of their regulators timp-1 and timp-2 relative to unirradiated controls. This translated into increased collagenolytic and gelatinolytic activity and could be reduced after valproic acid (VA) treatment. Additionally, VA also mitigated IR-enhanced mmp and timp mRNA expression as well as IR-increased invasion capability. Finally, our data confirm the radiosensitizing effect of VA.

CONCLUSION

These results suggest that IR cell line-dependently induces upregulation of MMP mRNA expression, which appears to be mechanistically linked to a higher invasion capability that is modifiable by HDAC inhibition.

Broad targeting of angiogenesis for cancer prevention and therapy

Deregulation of angiogenesis – the growth of new blood vessels from an existing vasculature – is a main driving force in many severe human diseases including cancer. As such, tumor angiogenesis is important for delivering oxygen and nutrients to growing tumors, and therefore considered an essential pathologic feature of cancer, while also playing a key role in enabling other aspects of tumor pathology such as metabolic deregulation and tumor dissemination/metastasis. Recently, inhibition of tumor angiogenesis has become a clinical anti-cancer strategy in line with chemotherapy, radiotherapy and surgery, which underscore the critical importance of the angiogenic switch during early tumor development. Unfortunately the clinically approved anti-angiogenic drugs in use today are only effective in a subset of the patients, and many who initially respond develop resistance over time. Also, some of the anti-angiogenic drugs are toxic and it would be of great importance to identify alternative compounds, which could overcome these drawbacks and limitations of the currently available therapy. Finding “the most important target” may, however, prove a very challenging approach as the tumor environment is highly diverse, consisting of many different cell types, all of which may contribute to tumor angiogenesis. Furthermore, the tumor cells themselves are genetically unstable, leading to a progressive increase in the number of different angiogenic factors produced as the cancer progresses to advanced stages. As an alternative approach to targeted therapy, options to broadly interfere with angiogenic signals by a mixture of non-toxic natural compound with pleiotropic actions were viewed by this team as an opportunity to develop a complementary anti-angiogenesis treatment option. As a part of the “Halifax Project” within the “Getting to know cancer” framework, we have here, based on a thorough review of the literature, identified 10 important aspects of tumor angiogenesis and the pathological tumor vasculature which would be well suited as targets for anti-angiogenic therapy: (1) endothelial cell migration/tip cell formation, (2) structural abnormalities of tumor vessels, (3) hypoxia, (4) lymphangiogenesis, (5) elevated interstitial fluid pressure, (6) poor perfusion, (7) disrupted circadian rhythms, (8) tumor promoting inflammation, (9) tumor promoting fibroblasts and (10) tumor cell metabolism/acidosis. Following this analysis, we scrutinized the available literature on broadly acting anti-angiogenic natural products, with a focus on finding qualitative information on phytochemicals which could inhibit these targets and came up with 10 prototypical phytochemical compounds: (1) oleanolic acid, (2) tripterine, (3) silibinin, (4) curcumin, (5) epigallocatechin-gallate, (6) kaempferol, (7) melatonin, (8) enterolactone, (9) withaferin A and (10) resveratrol. We suggest that these plant-derived compounds could be combined to constitute a broader acting and more effective inhibitory cocktail at doses that would not be likely to cause excessive toxicity. All the targets and phytochemical approaches were further cross-validated against their effects on other essential tumorigenic pathways (based on the “hallmarks” of cancer) in order to discover possible synergies or potentially harmful interactions, and were found to generally also have positive involvement in/effects on these other aspects of tumor biology. The aim is that this discussion could lead to the selection of combinations of such anti-angiogenic compounds which could be used in potent anti-tumor cocktails, for enhanced therapeutic efficacy, reduced toxicity and circumvention of single-agent anti-angiogenic resistance, as well as for possible use in primary or secondary cancer prevention strategies.

Down-regulation of TIMP-1 inhibits cell migration, invasion, and metastatic colonization in lung adenocarcinoma

Tissue inhibitor metalloproteinase-1 (TIMP-1) is clinically associated with a poor prognosis for various cancers, but the roles of TIMP-1 in lung cancer metastasis are controversial. Our previous secretomic study revealed that TIMP-1 is highly abundant in high invasiveness cells of lung adenocarcinoma. In the current study, TIMP-1 abundances in primary lung adenocarcinoma tissues, as revealed by immunohistochemistry, are significantly higher in patients with lymph invasion and distant metastasis than in those without. Receiver operating characteristic curve analyses suggest 73.7 and 86.2 % accuracy to separate patients with lymph node and distant metastasis and those without, respectively. Moreover, we demonstrate that the expression level of TIMP-1 positively associates with cell mobility, invasiveness, and metastatic colonization. Most notably, the novel mechanism in which TIMP-1 facilitates metastatic colonization through the mediation of pericellular polyFN1 assembly was revealed. In summary, this study presents novel functions of TIMP-1 in promoting cancer metastasis and suggests TIMP-1 is a potential tissue biomarker for lymph invasion and distant metastasis of lung adenocarcinoma.

Serum amyloid A promotes invasion of feline mammary carcinoma cells

The serum amyloid A (SAA) concentration is higher in mammary tumors with metastases in both humans and animals. In the present study, the direct effects of recombinant feline SAA (rfSAA) protein on invasiveness of feline mammary carcinoma cells were evaluated. As an indicator of invasiveness, matrix metalloproteinase-9 (MMP-9) expression was investigated in 4 feline mammary carcinoma cell lines of different origins. In 3 of 4 cell lines, MMP-9 expression was significantly increased by rfSAA stimulation. The invasive capacities of feline mammary carcinoma cells were also stimulated by rfSAA. The findings of this study have identified a novel role for SAA in mammary tumorigenesis and suggest that therapeutic strategies targeting SAA may provide new alternatives in treating tumor invasion and metastasis.

Plasma levels of the MMP-9:TIMP-1 complex as prognostic biomarker in breast cancer: a retrospective study

Background

Worldwide more than one million women are annually diagnosed with breast cancer. A considerable fraction of these women receive systemic adjuvant therapy; however, some are cured by primary surgery and radiotherapy alone. Prognostic biomarkers guide stratification of patients into different risk groups and hence improve management of breast cancer patients. Plasma levels of Matrix Metalloproteinase-9 (MMP-9) and its natural inhibitor Tissue inhibitor of metalloproteinase-1 (TIMP-1) have previously been associated with poor patient outcome and resistance to certain forms of chemotherapy. To pursue additional prognostic information from MMP-9 and TIMP-1, the level of the MMP-9 and TIMP-1 complex (MMP-9:TIMP-1) was investigated in plasma from breast cancer patients.

Methods

Detection of protein:protein complexes in plasma was performed using a commercially available ELISA kit and, for the first time, the highly sensitive in-solution proximity ligation assay (PLA). We screened plasma from 465 patients with primary breast cancer for prognostic value of the MMP-9:TIMP-1 complex. Both assays were validated and applied for quantification of MMP-9:TIMP-1 concentration. In this retrospective study, we analyzed the association between the concentration of the MMP-9:TIMP-1 complex and clinicopathological data and disease free survival (DFS) in univariate and multivariate survival analyses.

Results

Following successful validation both assays were applied for MMP-9:TIMP-1 measurements. Of the clinicopathological parameters, only menopausal status demonstrated significant association with the MMP-9:TIMP-1 complex; P = 0.03 and P = 0.028 for the ELISA and PLA measurements, respectively. We found no correlation between the MMP-9:TIMP-1 protein complex and DFS neither in univariate nor in multivariate survival analyses.

Conclusions

Despite earlier reports linking MMP-9 and TIMP-1 with prognosis in breast cancer patients, we here demonstrate that plasma levels of the MMP-9:TIMP-1 protein complex hold no prognostic information in primary breast cancer as a stand-alone marker. We demonstrate that the highly sensitive in-solution PLA can be employed for measurements of protein:protein complexes in plasma.

Enhancement of DEN-induced liver tumourigenesis in hepatocyte-specific Lass2-knockout mice coincident with upregulation of the TGF-β1-Smad4-PAI-1 axis

Longevity assurance homolog 2 of yeast LAG1 (Lass2) gene is capable of suppressing the proliferation and metastasis of several types of tumours including liver cancer. In the present study, hepatocyte-specific Lass2-knockout (Lass2 KO) and wild-type (WT) mice were exposed to the carcinogen, diethylnitrosamine (DEN), to induced liver tumours. At week 23 following DEN injection, tumours were produced in 100% of the Lass2 KO mice and 21.4% of the WT mice. At week 40, 100% of the Lass2 KO mice and 78.6% of the WT mice developed tumours, with no distinct significant difference in tumour occurrences between the two genotypes; yet, tumours in the Lass2 KO mouse livers were more numerous and larger in size. Hepatocellular carcinoma (HCC) was confirmed by α-fetoprotein (AFP). PCNA and EdU assays indicated more active proliferation whereas TUNEL assay revealed decreased apoptosis in Lass2 KO livers, when compared with the WT control. The expression of plasminogen activator inhibitor type-1 (PAI-1), a tumour-promoting gene, in the liver tissues of the 2 genotypes was detected using qPCR and western blotting, showing that PAI-1 levels were significantly elevated in Lass2 KO livers at week 40 following DEN introduction. Moreover, the expression of PAI-1-related TGF-β1, Smad-4 and -7 was detected, displaying an elevation in TGF-β1 and Smad-4 (not including Smad-7) in the Lass2 KO livers. Our data demonstrates that i) Lass2 is a protective gene against DEN-induced liver tumourigenesis; and ii) upregulation of the TGF-β1-Smad4-PAI-1 axis may contribute to the vulnerability of Lass2-knockout mice to DEN.

TIMP-1 increases expression and phosphorylation of proteins associated with drug resistance in breast cancer cells

Tissue inhibitor of metalloproteinase 1 (TIMP-1) is a protein with a potential biological role in drug resistance. To elucidate the unknown molecular mechanisms underlying the association between high TIMP-1 levels and increased chemotherapy resistance, we employed SILAC-based quantitative mass spectrometry to analyze global proteome and phosphoproteome differences of MCF-7 breast cancer cells expressing high or low levels of TIMP-1. In TIMP-1 high expressing cells, 312 proteins and 452 phosphorylation sites were up-regulated. Among these were the cancer drug targets topoisomerase 1, 2A, and 2B, which may explain the resistance phenotype to topoisomerase inhibitors that was observed in cells with high TIMP-1 levels. Pathway analysis showed an enrichment of proteins from functional categories such as apoptosis, cell cycle, DNA repair, transcription factors, drug targets and proteins associated with drug resistance or sensitivity, and drug transportation. The NetworKIN algorithm predicted the protein kinases CK2a, CDK1, PLK1, and ATM as likely candidates involved in the hyperphosphorylation of the topoisomerases. Up-regulation of protein and/or phosphorylation levels of topoisomerases in TIMP-1 high expressing cells may be part of the mechanisms by which TIMP-1 confers resistance to treatment with the widely used topoisomerase inhibitors in breast and colorectal cancer.

Inflammation induced by MMP-9 enhances tumor regression of experimental breast cancer

Matrix metalloproteinases (MMPs) have been suggested as therapeutic targets in cancer treatment, but broad-spectrum MMP inhibitors have failed in clinical trials. Recent data suggest that several MMPs including MMP-9 exert both pro- and antitumorigenic properties. This is also the case of the natural inhibitors of MMPs, tissue inhibitor of metalloproteinases (TIMPs). The inhibitor of MMP-9 is TIMP-1, and high levels of this enzyme have been associated with decreased survival in breast cancer. Inflammation is one hallmark of cancer progression, and MMPs/TIMPs may be involved in the local immune regulation. We investigated the role of MMP-9/TIMP-1 in regulating innate antitumor immunity in breast cancer. Breast cancers were established in nude mice and treated with intratumoral injections of adenoviruses carrying the human TIMP-1 or MMP-9 gene (AdMMP-9). In vivo microdialysis for sampling of cancer cell-derived (human) and stroma-derived (murine) proteins, immunostainings, as well as cell cultures were performed. We report a dose-dependent decrease of tumor growth and angiogenesis after AdMMP-9 treatment. In addition to increased generation of endostatin, AdMMP-9 promoted an antitumor immune response by inducing massive neutrophil infiltration. Neutrophil depletion prior to gene transfer abolished the therapeutic effects of AdMMP-9. Additionally, AdMMP-9 activated tumor-infiltrating macrophages into a tumor-inhibiting phenotype both in vivo and in vitro. AdMMP-9 also inhibited tumor growth in immune-competent mice bearing breast cancers. Adenoviruses carrying the human TIMP-1 gene had no effect on tumor growth or the immune response. Our novel data identify MMP-9 as a potent player in modulating the innate immune response into antitumor activities.

Tumour-microenvironment interactions: role of tumour stroma and proteins produced by cancer-associated fibroblasts in chemotherapy response

BACKGROUND

Cytotoxic chemotherapy improves survival for some, but not all, cancer patients. Non-responders may experience unnecessary toxicity and cancer progression, thus creating an urgent need for biomarkers that can predict the response to chemotherapy. So far, the search for such biomarkers has primarily been focused on the cancer cells and less on their surrounding stroma. This stroma is known to act as a key regulator of tumour progression and, in addition, has been associated with drug delivery and drug efficacy. Fibroblasts represent the major cell type in cancer-associated stroma and they secrete extracellular matrix proteins as well as growth factors. This Medline-based literature review summarises the results from studies on epithelial cancers and aimed at investigating relationships between the quantity and quality of the intra-tumoral stroma, the cancer-associated fibroblasts, the proteins they produce and the concomitant response to chemotherapy. Biomarkers were selected for review that are known to affect cancer-related characteristics and patient prognosis.

RESULTS

The current literature supports the hypothesis that biomarkers derived from the tumour stroma may be useful to predict response to chemotherapy. This notion appears to be related to the overall quantity and cellularity of the intra-tumoural stroma and the predominant constituents of the extracellular matrix.

CONCLUSION

Increasing evidence is emerging showing that tumour-stroma interactions may not only affect tumour progression and patient prognosis, but also the response to chemotherapy. The tumour stroma-derived biomarkers that appear to be most appropriate to determine the patient's response to chemotherapy vary by tumour origin and the availability of pre-treatment tissue. For patients scheduled for adjuvant chemotherapy, the most promising biomarker appears to be the PLAU: SERPINE complex, whereas for patients scheduled for neo-adjuvant chemotherapy the tumour stroma quantity appears to be most relevant.

Prognostic significance of tissue inhibitor of metalloproteinase-1 in breast cancer

Introduction. Despite advances in breast cancer systemic treatment, new prognostic and predictive factors are still needed. Tissue inhibitor of metalloproteinase-1 (TIMP-1), a physiologic inhibitor of matrix metalloproteinases (MMPs), can act in both pro- and antitumoral effects. As role of TIMP-1 in breast cancer is controversial, we aimed to determine the prognostic significance of TIMP-1 in breast cancer. Methods. A single center-based case-control study was applied. Primary breast cancers from women with early stage disease treated with standard adjuvant therapy were analyzed by gene expression microarrays and immunohistochemistry for TIMP-1. Results. At the optimized cut-point, patients with high TIMP-1 RNA levels had a significantly shorter time to relapse, with a hazard ratio (HR) of 1.64 (P = 0.04), but without significant differences in overall survival (HR 1.29, P = 0.37). Although cytoplasmic overexpression of TIMP-1 protein was not correlated with early relapse (HR 1.0, P = 0.92), there was a tendency for short overall survival in patients with high expression (HR 1.41, P = 0.21). Conclusions. Our data indicate that elevated TIMP-1 RNA levels are independently prognostic for early recurrence, and there is a tendency for association of high cytoplasmic TIMP-1 protein levels with short survival in primary breast cancer.

Tissue inhibitor of metalloproteinase 1 expression associated with gene demethylation confers anoikis resistance in early phases of melanocyte malignant transformation

Although anoikis resistance has been considered a hallmark of malignant phenotype, the causal relation between neoplastic transformation and anchorage-independent growth remains undefined. We developed an experimental model of murine melanocyte malignant transformation, where a melanocyte lineage (melan-a) was submitted to sequential cycles of anchorage blockade, resulting in progressive morphologic alterations, and malignant transformation. Throughout this process, cells corresponding to premalignant melanocytes and melanoma cell lines were established and show progressive anoikis resistance and increased expression of Timp1. In melan-a melanocytes, Timp1 expression is suppressed by DNA methylation as indicated by its reexpression after 5-aza-2'-deoxycytidine treatment. Methylation-sensitive single-nucleotide primer extension analysis showed increased demethylation in Timp1 in parallel with its expression along malignant transformation. Interestingly, TIMP1 expression has already been related with negative prognosis in some human cancers. Although described as a MMP inhibitor, this protein has been associated with apoptosis resistance in different cell types. Melan-a cells overexpressing Timp1 showed increased survival in suspension but were unable to form tumors in vivo, whereas Timp1-overexpressing melanoma cells showed reduced latency time for tumor appearance and increased metastatic potential. Here, we demonstrated for the first time an increment in Timp1 expression since the early phases of melanocyte malignant transformation, associated to a progressive gene demethylation, which confers anoikis resistance. In this way, Timp1 might be considered as a valued marker for melanocyte malignant transformation.

Clinical utility of level-of-evidence-1 disease forecast cancer biomarkers uPA and its inhibitor PAI-1

The prognostic and/or predictive value of the cancer biomarkers, urokinase-type plasminogen activator (uPA) and its inhibitor (plasminogen activator inhibitor [PAI]-1), determined by ELISA in tumor-tissue extracts, was demonstrated for several cancer types in numerous clinically relevant retrospective or prospective studies, including a multicenter breast cancer therapy trial (Chemo-N0). Consequently, for the first time ever for any cancer biomarker for breast cancer, uPA and PAI-1 have reached the highest level of evidence, level-of-evidence-1. At present, two other breast cancer therapy trials, NNBC-3 and Plan B, also incorporating uPA and PAI-1 as treatment-assignment tools are in effect. Furthermore, small synthetic molecules targeting uPA are currently in Phase II clinical trials in patients afflicted with advanced cancer of the ovary, breast or pancreas.

Effects of dietary fat on spontaneous metastasis of Lewis lung carcinoma in mice

The present study assessed the effects of dietary fat on spontaneous metastasis of Lewis lung carcinoma in mice. Three-week old male C57BL/6 mice were fed the AIN-93G diet or a 45% fat diet (% kcal.) for 7 weeks before they were subcutaneously injected with 2.5 × 10⁵ viable carcinoma cells. The primary tumor was resected 2 weeks later, and mice were maintained on their respective diets for an additional 2 weeks. The high-fat diet significantly increased body weight and abdominal adipose weight compared to the AIN-93G diet. Feeding mice the 45% fat diet resulted in a two-fold increase in the number of lung metastases (P < 0.05), a 35% increase in tumor cross-sectional area, and a 50% increase in tumor volume compared to mice fed the AIN-93G diet. There were no differences in plasma concentrations of TIMP-1, IL-1β, VEGF and MCP-1 in non-tumor-bearing mice fed the AIN-93G diet or the high-fat diet, but significant increases in these cytokines in tumor-bearing mice fed the AIN-93G diet compared to the non-tumor-bearing mice fed the same diet (P < 0.05 for each comparison). Further significant increases in these cytokines in tumor-bearing mice fed the 45% fat diet compared to the same tumor-bearing mice fed the AIN-93G diet (P < 0.05 for each comparison). The high-fat diet significantly increased plasma leptin and significantly decreased plasma adiponectin compared to the AIN-93G diet in both non-tumor-bearing and tumor-bearing mice. Results of the present study demonstrated that the high-fat diet enhanced spontaneous metastasis of Lewis lung carcinoma in mice and that this aggressiveness was accompanied with significant increases in plasma concentrations of angiogenic cytokines, suggesting that dietary fat affects metastasis by promoting angiogenic processes.

Immunohistochemical study of matrix metalloproteinases and their inhibitors in pure and mixed invasive and in situ ductal carcinomas of the breast

We assessed differences in the patterns of expression of matrix metalloproteases and their inhibitors (tissue inhibitors of metalloproteases) in ductal carcinoma in situ alone and admixed with invasive ductal carcinomas (n = 40), as well as in pure invasive ductal carcinomas (n = 40), immunohistochemically and using tissue arrays. The invasive ductal carcinoma components showed higher expression of matrix metalloprotease-9 and -13 than did the admixed ductal carcinoma in situ, whereas stromal fibroblasts of the invasive components showed higher expression of matrix metalloprotease-2, -7, -9, -13, and -14 and tissue inhibitor of metalloprotease-1 and -3 than did fibroblasts around the neoplastic ducts of the admixed ductal carcinoma in situ. Expression of matrix metalloprotease-14 and tissue inhibitor of metalloprotease-3 was significantly higher in the mononuclear inflammatory cells of the invasive components. By contrast, matrix metalloprotease-1 expression was significantly higher in stromal cells of the ductal carcinoma in situ admixed with invasive ductal carcinoma. The pure invasive ductal carcinomas had significantly higher expression of matrix metalloprotease-1, -9, -11, and -14 and tissue inhibitor of metalloprotease-1 and -3 than the invasive ductal carcinomas admixed with ductal carcinoma in situ. Our findings indicate a significant association of matrix metalloprotease expression by the periductal stromal cells of the ductal carcinoma in situ component of mixed tumors and the occurrence of distant metastasis. Our data suggest that the molecular matrix metalloprotease/tissue inhibitor of metalloprotease profile can contribute to better characterization of early breast carcinomas.

Expression of metalloproteases and their inhibitors in primary tumors and in local recurrences after mastectomy for breast cancer

AIMS

To investigate the expression of matrix metalloproteases (MMPs) and their inhibitors (TIMPs) in patients who develop local recurrence (LR) after mastectomy.

METHODS

We analyzed the expressions of MMP-1, -2, -7, -9, -11, -13, -14, TIMP-1, -2, and -3, using immunohistochemical techniques, in primary tumors from patients without tumoral recurrence (n = 50), patients who developed distant metastasis (n = 50), and from patients who develop LRs (n = 25). LRs of the latter group were also analyzed for MMPs expression. All the patients underwent mastectomy.

RESULTS

Score values for all MMPs and TIMPs were significantly higher in primary tumors of patients with distant metastasis. Primary tumors from patients with LR have lower expressions of MMPs and TIMPs compared with those from patients who developed distant metastasis, and with patients without recurrence for some MMPs. Remarkably, however, primary tumors from patients with LR showed significantly higher percentage of TIMP-1 and 2 expression in stromal cells compared to primary tumors from patients with distant metastasis or primary tumors from patients without tumoral progression. Furthermore, LRs had significantly higher MMP-9 expression than their corresponding primary tumors.

CONCLUSIONS

Our data indicate differences in MMPs/TIMPs expression between primary tumors of patients with LRs and of those with distant metastasis, both after mastectomy for breast cancer.

Clinical biomarkers in oncology: focus on colorectal cancer

Rapidly growing insight into the molecular biology of colorectal cancer has led to high hopes for the identification of molecular markers to be used in optimized and tailored treatment regimens. However, many of the published data on gene-specific biomarkers are contradictory in their findings, and no tests are currently used in clinical practice, with the exception of microsatellite instability (MSI) and guanylyl cyclase C (GCC) testing in the adjuvant setting, and in Europe KRAS mutation testing is used in the setting of epidermal growth factor receptor (EGFR)-targeted therapy for metastatic disease. There are many reasons for the failure of the initial marker hypothesis-driven approach. Although supported by a good biologic rationale, single markers such as tumor protein p53 (TP53) gene mutations, when applied to a complex tumor type containing many synchronous alterations, do not perform well in predicting outcome. Many markers also suffer from technical shortcomings, resulting from the lack of quantitative techniques to capture the impact of the molecular alteration. The impact of markers obtained from microarray expression profiling needs to be further investigated in studies based on much larger cohorts, and cross-validation studies will be essential. Recently, mutations in the KRAS gene were shown to be strong negative predictors of response to EGFR inhibitors in metastatic disease. It has also been suggested that BRAF gene mutations may be predictive of EGFR inhibitor resistance, and there are some conflicting data regarding the role of the PIK3CA gene. Further studies are needed to help integrate the latest findings into clinically useful tools for personalized medicine.

Tumor tissue levels of Tissue Inhibitor of Metalloproteinases-1 (TIMP-1) and outcome following adjuvant chemotherapy in premenopausal lymph node-positive breast cancer patients: A retrospective study

Background

We have previously demonstrated that high tumor tissue levels of TIMP-1 are associated with no or limited clinical benefit from chemotherapy with CMF and anthracyclines in metastatic breast cancer patients. Here, we extend our investigations to the adjuvant setting studying outcome after adjuvant chemotherapy in premenopausal lymph node-positive patients. We hypothesize that TIMP-1 high tumors are less sensitive to chemotherapy and accordingly that high tumor tissue levels are associated with shorter survival.

Methods

From our original retrospectively collected tumor samples we selected a group of 525 pre-menopausal lymph node-positive patients (adjuvant treatment: CMF, 324 patients; anthracycline-based, 99 patients; no adjuvant chemotherapy, 102 patients). TIMP-1 levels were measured using ELISA in cytosolic extracts of frozen primary tumors. TIMP-1 was analyzed as a continuous variable and as a dichotomized one using the median TIMP-1 concentration as a cut point between high and low TIMP-1 groups. We analyzed the benefit of adjuvant CMF and anthracyclines in univariate and multivariable survival models; endpoints were disease-free (DFS) and overall survival (OS).

Results

In this selected cohort of high-risk patients, and in the subgroup of patients receiving no adjuvant therapy, TIMP-1 was not associated with prognosis. In the subgroup of patients treated with anthracyclines, when analyzed as a continuous variable we observed a tendency for increasing TIMP-1 levels to be associated with shorter DFS (multivariable analysis, HR 1.75, 95% CI 1.00-3.07, P = 0.05) and a significant association between increasing TIMP-1 and shorter OS in both univariate (HR 3.52, 95% CI 1.54-8.06, P = 0.003) and multivariable analyses (HR 4.19, 95% CI 1.67-10.51, P = 0.002). No statistically significant association between TIMP-1 and DFS was observed in the CMF-treated patients although high TIMP-1 was associated with shorter OS when analyzed as a dichotomized variable (HR 1.64, 95% CI 1.02-2.65, P = 0.04).

Conclusion

In the subgroup of patients receiving adjuvant chemotherapy we found an association between shorter survival after treatment in TIMP-1 high patients compared with TIMP-1 low patients, especially in patients receiving anthracycline-based therapy. This suggests that high tumor tissue levels of TIMP-1 might be associated with reduced benefit from classical adjuvant chemotherapy. Our findings should be validated in larger prospective studies.

Association between tumor tissue TIMP-1 levels and objective response to first-line chemotherapy in metastatic breast cancer

In a previous study from our laboratory, high tumor levels of tissue inhibitor of metalloproteinases-1 (TIMP-1) have been associated with an adverse response to chemotherapy in metastatic breast cancer suggesting that TIMP-1, which is known to inhibit apoptosis, may be a new predictive marker in this disease. The purpose of this study was to investigate the association between TIMP-1 and objective response to chemotherapy in an independent patient population consisting of patients with metastatic breast cancer from Sweden and Denmark. TIMP-1 was measured using ELISA in 162 primary tumor extracts from patients who later developed metastatic breast cancer and these levels were related to the objective response to first-line chemotherapy. Increasing levels of TIMP-1 were associated with a decreasing probability of response to treatment, reaching borderline significance (OR = 1.59, 95% CI: 0.97-2.62, P = 0.07). This OR is very similar to the result from our previous study. Increasing levels of TIMP-1 were also associated with a shorter disease-free survival and overall survival, however, not statistically significant. The results from the present study support previous data that TIMP-1 is associated with objective response to chemotherapy for metastatic breast cancer.

Immunohistochemical expression of tissue inhibitor of metalloproteinase-1 (TIMP-1) in invasive breast carcinoma

Tissue inhibitor of metalloproteinase-1 (TIMP-1) is a natural inhibitor of matrix metalloproteinases (MMPs). Aim of this study was to assess the immunohistochemical expression of TIMP-1 in invasive breast carcinomas, and to examine its association with classical clinico-pathological parameters, oestrogen receptor, progesterone receptor and Her-2/neu protein expression. Immunohistochemistry was used to determine the expression of TIMP-1 on 38 paraffin-embedded breast tissue specimens - 18 with invasive ductal carcinoma, 10 with invasive lobular carcinoma, and 10 specimens from patients with fibrocystic breast disease. TIMP-1 protein was immunodetected in the carcinoma cells, fibroblasts and inflammatory cells of the stroma in 92,9%, 65,8%, and 65,8% of cases, respectively. TIMP-1 protein expression in carcinoma cells showed positive correlation with TIMP-1 protein expression in peritumoural fibroblasts (p=0,010). Positive peritumoural fibroblast TIMP-1 expression was associated with histological tumour type with higher frequency in ductal carcinomas (p=0,023). Negative association was found between TIMP-1 protein expression in carcinoma cells and HER-2/neu nuclear staining (p=0,005). TIMP-1 may be particularly useful as a predictive marker in breast carcinoma when evaluated along with HER-2/neu protein being a promising indicator of favourable prognosis in breast carcinoma.

Lack of TIMP-1 tumour cell immunoreactivity predicts effect of adjuvant anthracycline-based chemotherapy in patients (n=647) with primary breast cancer. A Danish Breast Cancer Cooperative Group Study

PURPOSE

A number of prospective studies have shown that adjuvant CEF significantly improves disease-free and overall survival as compared to CMF in breast cancer patients. Our aim was to determine whether the benefit of epirubicin versus methotrexate differs according to TIMP-1 tumour cell immunoreactivity.

EXPERIMENTAL DESIGN

Tissue micro arrays from 647 patients randomly assigned to CMF or CEF in DBCG trial 89D were included. The primary end-point was invasive disease-free survival (IDFS). A central assessment of tissue inhibitor of metalloproteinases 1 (TIMP-1) status was performed using immunohistochemistry (IHC). Tumours were regarded as TIMP-1 positive if epithelial breast cancer cells were stained using the anti-TIMP-1 monoclonal antibody VT7.

RESULTS

By central assessment 75% of tumours were classified as tumour cell TIMP-1 positive. Among CEF-treated patients, individuals with TIMP-1 negative tumours had a significant longer IDFS than patients with TIMP-1 positive tumours (p=0.047). The multivariate Cox regression analysis of IDFS showed that CEF was superior to CMF among patients with TIMP-1 negative tumours (hazard ratio (HR)=0.51; 95% confidence interval (CI): 0.31-0.84, p=0.0085), while no significant difference could be demonstrated among patients with TIMP-1 positive tumours (HR=0.88; 95% CI: 0.68-1.13, p=0.32). A non-significant TIMP-1 status (positive or negative) versus treatment (CMF or CEF) interaction was detected for IDFS (p=0.06) and OS (p=0.21).

CONCLUSION

Lack of TIMP-1 tumour cell immunoreactivity seems to predict a favourable effect of epirubicin-containing adjuvant therapy in primary breast cancer. However, an independent study is awaited to validate the potential predictive value of TIMP-1 immunoreactivity.

Study of matrix metalloproteinases and their tissue inhibitors in ductal in situ carcinomas of the breast

AIMS

To analyse the expression of metalloproteinases (MMPs) and their inhibitors (TIMPs) in ductal carcinoma in situ of the breast (DCIS).

METHODS AND RESULTS

An immunohistochemical study was performed in 56 patients with pure DCIS, in 39 with DCIS adjacent to invasive carcinoma (IDC) and 63 patients with T1 IDC, using tissue microarrays and specific antibodies against MMPs and TIMPs. Immunohistochemical results were categorized using a specific software program. The data were analysed by unsupervised hierarchical cluster analysis by each cellular type. IDC showed a higher expression rate of MMP-7 and TIMP-1 than pure DCIS, as well as a higher expression rate of MMP-9 and TIMP-3 than the DCIS component of mixed cases, whereas pure DCIS showed a higher rate of expression of MMP-9 and -11 and TIMP-3 than in the DCIS component of mixed cases. Pure DCIS with a periductal inflammatory infiltrate showed significantly higher MMP-2, -14 and TIMP-1. Dendograms identified two cluster groups with distinct MMP/TIMP expression profiles in neoplastic cells and fibroblastic or mononuclear inflammatory cells surrounding the neoplastic ducts of pure DCIS.

CONCLUSIONS

The results indicate the distinct variability in MMP/TIMP expression by DCIS, which may be of potential biological and clinical interest in breast cancer.

Correlation between MMPs and their inhibitors in breast cancer tumor tissue specimens and in cell lines with different metastatic potential

Background

The metastatic disease rather than the primary tumor itself is responsible for death in most solid tumors, including breast cancer. The role of matrix metalloproteinases (MMPs), tissue inhibitors of MMPs (TIMPs) and Reversion-inducing cysteine-rich protein with Kazal motifs (RECK) in the metastatic process has previously been established. However, in all published studies only a limited number of MMPs/MMP inhibitors was analyzed in a limited number of cell lines. Here, we propose a more comprehensive approach by analyzing the expression levels of several MMPs (MMP-2, MMP-9 and MMP-14) and MMP inhibitors (TIMP-1, TIMP-2 and RECK) in different models (five human breast cancer cell lines, 72 primary breast tumors and 30 adjacent normal tissues).

Methods

We analyzed the expression levels of MMP-2, MMP-9 and MMP-14 and their inhibitors (TIMP-1, TIMP-2 and RECK) by quantitative RT-PCR (qRT-PCR) in five human breast cancer cell lines presenting increased invasiveness and metastatic potential, 72 primary breast tumors and 30 adjacent normal tissues. Moreover, the role of cell-extracellular matrix elements interactions in the regulation of expression and activity of MMPs and their inhibitors was analyzed by culturing these cell lines on plastic or on artificial ECM (Matrigel).

Results

The results demonstrated that MMPs mRNA expression levels displayed a positive and statistically significant correlation with the transcriptional expression levels of their inhibitors both in the cell line models and in the tumor tissue samples. Furthermore, the expression of all MMP inhibitors was modulated by cell-Matrigel contact only in highly invasive and metastatic cell lines. The enzyme/inhibitor balance at the transcriptional level significantly favors the enzyme which is more evident in tumor than in adjacent non-tumor tissue samples.

Conclusion

Our results suggest that the expression of MMPs and their inhibitors, at least at the transcriptional level, might be regulated by common factors and signaling pathways. Therefore, the multi-factorial analysis of these molecules could provide new and independent prognostic information contributing to the determination of more adequate therapy strategies for each patient.

TIMP-1 overexpression promotes tumorigenesis of MDA-MB-231 breast cancer cells and alters expression of a subset of cancer promoting genes in vivo distinct from those observed in vitro

TIMP-1 (Tissue inhibitor of matrix metalloproteinase-1) is typically associated with inhibition of matrix metalloproteinases (MMP) induced invasion. However, TIMP-1 is overexpressed in many malignancies and is associated with poor prognosis in breast cancer. The mechanisms by which TIMP-1 promotes tumorigenesis are unclear. Reduced levels of TIMP-1 mediated by shRNA in MDA-MB-231 breast cancer cells had no effect on cellular physiology in vitro or tumor growth in SCID mice compared to vector control MDA-MB-231 cells. However, overexpression of TIMP-1 in MDA-MB-231 cells resulted in inhibition of cell invasion and enhanced phosphorylation of p38 MAPK and AKT in vitro. Additionally, treatment of parental MDA-MB-231 cells with purified TIMP-1 protein led to activation of p38 MAPK and MKK 3/6. cDNA array analysis demonstrated that high expression of TIMP-1 in MDA-MB-231 cells resulted in alterations in expression of approximately 200 genes, 1.5 fold or greater compared to vector control cells (P < 0.1). Real-time RT-PCR confirmed changes in expression of several genes associated with cancer progression including DAPK1, FGFR4 and MAPK13. In vivo, high TIMP-1 expression induced tumor growth in SCID mice compared to vector control cells and increased tumor vessel density. Affymetrix array analysis of vector control and TIMP-1 MDA-MB-231 xenograft tumors revealed that TIMP-1 altered expression of approximately 600 genes in vivo, including MMP1, MMP13, S100A14, S100P, Rab25 and ID4. These combined observations suggest that the effects of TIMP-1 differ significantly in a 2-D environment compared to the 3-D environment and that TIMP-1 stimulates tumor growth.

Biology and potential clinical implications of tissue inhibitor of metalloproteinases-1 in colorectal cancer treatment

Colorectal cancer (CRC) is the second leading cause of cancer-related death in the industrialized world. About half of "curatively" resected patients develop recurrent disease within the next 3-5 years despite the lack of clinical, histological and biochemical evidence of remaining overt disease after resection of the primary tumour. Availability of validated biological markers for early detection, selection for adjuvant therapy, prediction of treatment efficacy and monitoring of treatment efficacy would most probably increase survival. Tissue inhibitor of metalloproteinases-1 (TIMP-1) may be such a marker. TIMP-1 inhibits the proteolytic activity of metalloproteinases, which are centrally involved in tumour invasion and metastases. However, in clinical investigations high tumour tissue or plasma levels of TIMP-1 have shown a strong and independent association with a shorter survival time in CRC patients, suggesting that TIMP-1 could have a tumour-promoting function. Furthermore, measurement of plasma TIMP-1 has been shown to be useful for disease detection, with a high sensitivity and high specificity for early-stage colon cancer. This review describes some basic information on the current knowledge of the biology of TIMP-1 as well as the potential use of TIMP-1 as a biological marker in the management of CRC patients.

Tissue inhibitors of metalloproteinases in cell signaling: metalloproteinase-independent biological activities

Over the past 20 years, the tissue inhibitors of metalloproteinases (TIMPs) have been implicated in direct regulation of cell growth and apoptosis. However, the mechanisms of these effects have been controversial. Recent work by several laboratories has identified specific signaling pathways and cell surface binding partners for members of the TIMP family. TIMP-2 binding to the integrin alpha(3)beta(1) is the first description of a cell surface receptor for a TIMP family member. TIMP-2 has been shown to induce gene expression, to promote G(1) cell cycle arrest, and to inhibit cell migration. TIMP-1 binding to CD63 inhibits cell growth and apoptosis. These new findings suggest that TIMPs are multifunctional and can act either directly through cell surface receptors or indirectly through modulation of protease activity to direct cell fate. The emerging concept is that TIMPs function in a contextual fashion so that the mechanism of action depends on the tissue microenvironment.

TIMP-1 as a tumor marker in breast cancer--an update

Improvement of the management of breast cancer patients has high priority. In this regard, prognostic stratification needs to be improved in order to ensure proper medical treatment of all patients and furthermore predictors of response to chemotherapy are urgently needed. As new treatment opportunities emerge in the future this need will continue to grow. Thus, the search for molecular markers of prognosis and prediction is ongoing. Tissue Inhibitor of Metalloproteinases-1 (TIMP-1) has been suggested as a marker of both prognosis and response to treatment. Several studies have demonstrated the association between TIMP-1 and prognosis in breast cancer and new studies within this area have focused on the possibility of using blood samples or paraffin embedded tissue instead of tumor tissue extracts for measurements of TIMP-1. Interestingly, recent studies have investigated the association between TIMP-1 and response to treatment showing that TIMP-1 may also carry predictive information on response to treatment. In this regard, results from studies of the molecular functions of TIMP-1 point to a role of TIMP-1 in the inhibition of tumor cell apoptosis as an explanation for the clinical findings. This review gives an update on the ongoing investigation of the potential role of TIMP-1 as a tumor marker in breast cancer. Furthermore, we link the clinical findings with studies of the molecular actions of the TIMP-1 protein, raising hypotheses that may explain why TIMP-1 could play an important role in future management of breast cancer patients.

Comparative studies of tissue inhibitor of metalloproteinases-1 in plasma, serum and tumour tissue extracts from patients with primary colorectal cancer

OBJECTIVE

We have recently shown that preoperative plasma tissue inhibitor of metalloproteinases-1 (TIMP-1) levels are significantly associated with prognosis of colorectal cancer patients. In addition, we have shown that measurement of plasma TIMP-1 yields information on specificity and sensitivity, which could be used for early detection of colorectal cancer. However, it is not clear whether the increased plasma TIMP-1 levels in colorectal cancer patients are derived from the tumour tissue itself in which it is mainly expressed by the stromal cells located in the vicinity of the cancer cells. The purpose of this study was to examine the association between blood TIMP-1 levels and tumour tissue TIMP-1 levels in colorectal cancer patients.

MATERIAL AND METHODS

Preoperative EDTA plasma, citrate plasma and serum, as well as tumour tissue extracts from 49 colorectal cancer patients were measured with a TIMP-1 ELISA that measures total TIMP-1 levels (non-complexed and complexed TIMP-1).

RESULTS

The median TIMP-1 level in the 49 tumour extracts was 18.7 ng/mg proteins (range 3.5-152.0 ng/mg protein). The median TIMP-1 value was 133.5 ng/ml (range 58.1-559.0 ng/ml) in EDTA plasma, 130.2 ng/ml (range 57.0-572.0 ng/ml) in citrate plasma and 207.2 ng/ml (range 72.6-828.0 ng/ml) in serum. No significant correlations were found between TIMP-1 content in the tumour extracts and in blood.However, EDTA and citrate plasma TIMP-1 levels (r=0.75; p <0.0001) as well as EDTA plasma and serum TIMP-1 levels (r= .064; p<0.0001) were highly correlated.

CONCLUSIONS

The lack of correlation between tumour tissue TIMP-1 and blood levels of TIMP-1 suggests that other sources than the tumour tissue itself may contribute to the increased levels of plasma TIMP-1 in patients with colorectal cancer. However, degradation of cell membranes, rapid secretion into the blood stream and other factors may be responsible for the observed lack of association between TIMP-1 concentrations in blood and tumour tissue extracts.

Plasma and serum levels of tissue inhibitor of metalloproteinases-1 are associated with prognosis in node-negative breast cancer: a prospective study

The tumor level of TIMP-1 has been suggested as a new prognostic marker in breast cancer. The purpose of this study was to investigate whether TIMP-1 also carries prognostic information when measured in blood as this is a much more preferable material compared with tumor extracts. Using ELISA, TIMP-1 was measured in prospectively collected preoperative plasma and serum samples from 519 patients with primary breast cancer, and the measurements were related to patient outcome. The median age of the patients was 58 years (range, 38-80 years), and the median follow-up time was 1043 days (range, 300-1630 days). Plasma and serum TIMP-1 measurements correlated significantly with each other with a Pearson correlation coefficient of 0.75 (p < 0.0001). For univariate survival analysis, patients were divided into quartiles according to increasing TIMP-1 levels (Q1-Q4). Analysis of all patients showed that high TIMP-1 plasma levels were significantly associated with a shorter disease-free survival. Subgroup analysis showed that plasma TIMP-1 significantly predicted the prognosis of node-negative patients but not of node-positive patients. Importantly plasma TIMP-1 was able to further stratify low risk node-negative patients. High serum TIMP-1 levels were associated with a shorter disease-free survival; however, the association was not statistically significant. In contrast, serum TIMP-1 significantly predicted the prognosis of node-negative and low risk patients. In multivariate survival analysis of node-negative patients including all the classical prognostic parameters, plasma TIMP-1 remained significantly associated with prognosis when comparing Q1 with Q2 and Q4. Serum TIMP-1 remained significant when comparing Q1 with Q4. Taken together, this study is to our knowledge the first large prospective study suggesting that TIMP-1 carries independent prognostic information when measured in blood, especially plasma. This was especially true in the node-negative group of patients and in patients already defined as low risk patients using the currently available prognostic parameters.

Tissue inhibitor of metalloproteinases-1 stimulates gene expression in MDA-MB-435 human breast cancer cells by means of its ability to inhibit metalloproteinases

Tissue inhibitor of metalloproteinases-1 (TIMP-1) is a widely expressed, secreted protein that functions primarily to inhibit members of a large family of metalloproteinases (MPs). Because of the ability of TIMP-1 to inhibit MPs, it functions in many of the same pathophysiological processes as these enzymes, e.g. wound healing, ovulation, angiogenesis, and cancer cell metastasis. TIMP-1 can also stimulate proliferation ([3H]thymidine incorporation) and cellular anabolic processes (Alamar Blue reduction). This stimulation has been shown to be dependent on the MP-inhibitory ability of TIMP-1 in the human breast cancer cell line MDA-MB-435 (Porter et al., Br J Cancer 90: 463, 2004). To shed light on the mechanism by which TIMP-1 stimulates cellular anabolic processes, an oligonucleotide microarray analysis was performed over a time course of TIMP-1 treatment of MDA-MB-435 cells. Fifteen genes whose mRNAs were differentially regulated were identified. Six (Importin-7, MGC10471, FOXC1, subunit p20 of Arp2/3 complex, mitochondrial ribosomal protein L32, and the serine/threonine kinase-4 (MST1)) of these genes were confirmed by quantitative real time PCR. These same mRNAs were shown to be regulated by the synthetic hydroxamate MP-inhibitor GM6001 but not by its inactive derivative GM6001*, suggesting that the differential regulation occurs through the MP-inhibitory ability of TIMP-1. These results suggest a complex action of TIMP-1 on cancer cells mediated by constitutively active cell surface metalloproteinases that release factors regulating cell signaling pathways; they may account for the paradoxical observation that elevated levels of TIMP-1 in tumors can correlate with an adverse prognosis.

Overexpression of matrix metalloproteinases and their inhibitors in mononuclear inflammatory cells in breast cancer correlates with metastasis-relapse

An immunohistochemical study was performed using tissue microarrays and specific antibodies against matrix metalloproteinase (MMP)-1, -2, -7, -9, -11, -13 and –14, tissular inhibitors of metalloproteinase (TIMP)-1, -2 and -3. More than 2600 determinations on cancer specimens from 131 patients with primary ductal invasive tumours of the breast were performed. To identify specific groups of tumours with distinct expression profiles the data were analysed by unsupervised hierarchical cluster analysis by each cellular type. We did not find well-defined cluster of cases for tumour cells or fibroblastic cells. However, for mononuclear inflammatory cells the dendogram shows a first-order division of the tumours into two distinct MMP/TIMP molecular profiles, designated group 1 (n=89) and group 2 (n=42). Matrix metalloproteinase-7, -9, -11, -13 and -14, and TIMP-1 and -2, were identified as showing significant high expression in group 2 compared with group 1. Multivariate analysis demonstrated that clustering for mononuclear inflammatory cells was the most potent independent factor associated with distant relapse-free survival (group 2: 5.6 (3.5–9.6), P<0.001). We identify a phenotype of mononuclear inflammatory cells infiltrating tumours, which is associated with the development of distant metastasis. Therefore, this finding suggests that these host inflammatory cells could be a possible target for inhibition of metastasis.

Gender-dependent physiological implications of combined PAI-1 and TIMP-1 gene deficiency characterized in a mouse model

The endogenous proteinase inhibitors plasminogen activator inhibitor type 1 (PAI-1) and tissue inhibitor of metalloproteinase type 1 (TIMP-1) are two distinct proteins with separate molecular pathways. However, a close relationship between PAI-1 and TIMP-1 has been proposed indicating some degree of functional overlap due to their involvement in ECM turnover, tissue remodeling, and cellular migration and signaling. To study the housekeeping physiological implications of PAI-1 and TIMP-1, we generated a combined PAI-1 and TIMP-1 gene-deficient mouse model. We present the results on generating this specific mouse model with particular emphasis on phenotypical characteristics, blood leukocyte counts, histology, and gene expression studies of PAI-1 and TIMP-1 in various organs. We observed a significant deviation in segregation of offspring only in male mice (P < 0.01) predominantly caused by PAI-1 deficiency. In addition, the body weight in 3- and 20-wk-old male and 20-wk-old female mice was significantly different between genotypes (P <or= 0.0008). Furthermore, blood leukocyte counts were significantly different between genotypes in 20-wk-old male mice (P <or= 0.0002), whereas no significant differences were observed between genotypes in 20-wk-old female mice (P >or= 0.13). Quantifying the relative expression of PAI-1 and TIMP-1 revealed upregulation of PAI-1 (P < 0.001) in male mice only. Our data highlight the complex roles of PAI-1 and TIMP-1 on physiological parameters such as segregation of offspring (embryonic development and survival), body weight (metabolism), blood leukocyte counts (immunity), and gene expression (regulatory redundancy). We conclude that PAI-1 and TIMP-1 seem to possess gender-dependent regulatory properties on various housekeeping physiological parameters and stress the potential implications in pathological conditions.

Tumour markers in internal medicine: a low-cost test or an unnecessary expense? A retrospective study based on appropriateness

OBJECTIVE AND BACKGROUND

In the last 35 years tumour markers (TM) have gained currency in clinical practice. However, in the light of indications by international guidelines, their use is often unjustified. Our aim was to quantify the use of some of the most common TM, assessing their appropriateness and their efficacy in an Internal Medicine Unit.

METHODS

In the three Internal Medicine Units of the Department of Internal Medicine of Policlinico of Modena we have carried out a retrospective analysis of the assessment of the main TM (CEA, CA19.9, CA 125, CA 15.3, NSE). The analysis was divided into two distinct phases: (I) quantitative phase, in order to assess the scale of the problem in economical terms; (II) qualitative phase, in order to assess the efficacy of the tests and the appropriateness of their use.

RESULTS

(I) At last one of the considered TM was requested in 5102 out of the 8253 admitted patients (62%) (period 2001-2003). The trend was similar in all three units examined. (II) The qualitative analyses revealed: (1) the most common motivation for their use (79%) was diagnostic, mostly prior to any other test; (2) a mere 5% of the requests were appropriate according to the international literature; and (3) TM showed a low positive predictive value when used for diagnosis in an unselected population such as that of an Internal Medicine unit.

CONCLUSIONS

The results of our study showed that TM determination represents an overall cost for Internal Medicine units and that there is a high inappropriateness in their use compared to what it is suggested by international guidelines. Though the TM is a low-cost test when used correctly, it seems an unnecessary expense if not adequately incorporated into the decision making process.

Identification of alternatively spliced TIMP-1 mRNA in cancer cell lines and colon cancer tissue

TIMP-1 is a promising new candidate as a prognostic marker in colorectal and breast cancer. We now describe the discovery of two alternatively spliced variants of TIMP-1 mRNA. The two variants lacking exon 2 (del-2) and 5 (del-5), respectively, were identified in human cancer cell lines by RT-PCR. The del-2 variant was, furthermore, detected in extracts from 12 colorectal cancer tissue samples. By western blotting additional bands of lower molecular mass than full-length TIMP-1 were identified in tumor tissue, but not in plasma samples obtained from cancer patients. The two splice variants of TIMP-1 may hold important clinical information, and either alone or in combination with measurement of full-length TIMP-1 they may improve the prognostic and/or predictive value of TIMP-1 analyses.

Concentrations of TIMP1 mRNA splice variants and TIMP-1 protein are differentially associated with prognosis in primary breast cancer

BACKGROUND

TIMP-1 protein is a prognostic factor for recurrence-free and overall survival (OS) time in breast cancer. We evaluated the prognostic value of TIMP1 mRNA and a novel TIMP1 mRNA splice variant in 1301 primary breast cancer patients.

METHODS

We measured mRNA transcripts of full-length TIMP1 (TIMP1-v1) and the novel splice variant lacking exon 2 (TIMP1-v2) by use of real-time RT-PCR in frozen primary tumor samples. Transcript concentrations are correlated with histomorphological and biological factors, TIMP-1 protein, and distant metastasis-free survival (MFS) and OS time.

RESULTS

TIMP1-v1 and TIMP1-v2 alone were not informative with respect to predicting prognosis. However, the PCR assay designed to measure the combination of v1 + v2 showed that high concentrations of this combination were associated with good prognosis. In Cox multivariate regression analysis, which also included the traditional prognostic factors, increasing concentrations were independently associated with prolonged MFS (P = 0.004) and OS (P = 0.048). Including TIMP-1 protein and TIMP1-v1+v2 mRNA together in the multivariate model revealed that protein and mRNA were both independently associated with prognosis, with hazard ratios pointing in opposite directions.

CONCLUSION

High concentrations of TIMP1-v1+2 mRNA are associated with good prognosis in patients with primary breast cancer. Since high concentrations of TIMP-1 protein are associated with poor prognosis, the presence of possible posttranscriptional mechanisms requires further investigation.

Improvements in the search for potential biomarkers by proteomics: Application of principal component and discriminant analyses for two-dimensional maps evaluation

In this study, we evaluated if the application of multivariate analysis on the data obtained from two-dimensional protein maps could mean an improvement in the search for protein markers. First, we performed a classical proteomic study of the differential expression of serum N-glycoproteins in colorectal cancer patients. Then, applying principal component analysis (PCA) we assessed the utility of the 2-D protein pattern and certain subsets of spots as a tool to distinguish control and case samples, and tested the accuracy of the classification model by linear discriminant analysis (LDA). On the other hand we looked for altered spots by univariate statistics and then analysed them as a cluster by PCA and LDA. We found that those proteins combined presented a theoretical sensitivity and specificity of 100%. Finally, the spots with known protein identity were analysed by multivariate methods, finding a subgroup that behaved as the most obvious candidates for further validation trials.

Primary tumor levels of tissue inhibitor of metalloproteinases-1 are predictive of resistance to chemotherapy in patients with metastatic breast cancer

PURPOSE

Only about 50% of metastatic breast cancer patients benefit from cytotoxic chemotherapy. Today, no validated markers exist for prediction of chemotherapy sensitivity/resistance in this patient group. Tissue inhibitor of metalloproteinases-1 (TIMP-1) has been shown to protect against apoptosis, and the purpose of the present study was to test the hypothesis that tumors expressing high levels of TIMP-1 are protected against apoptosis-inducing agents and thus less sensitive to apoptosis-inducing chemotherapeutic drugs.

EXPERIMENTAL DESIGN

We investigated the association between primary tumor expression levels of TIMP-1 protein and objective response to first-line chemotherapy in 173 patients with metastatic breast cancer.

RESULTS

When analyzed as a continuous log-transformed variable, increasing TIMP-1 levels were significantly associated with lack of response to cyclophosphamide/methotrexate/5-fluorouracil and anthracycline-based chemotherapy (P = 0.01; odds ratio, 2.0; 95% confidence interval, 1.1-3.3). In a multivariate model, including lymph node status, steroid hormone receptor status, menopausal status, dominant metastases site, type of chemotherapy, and disease-free interval, TIMP-1 was significantly associated with resistance to treatment (P = 0.03; odds ratio, 1.7; 95% confidence interval, 1.1-3.3).

CONCLUSIONS

In the present exploratory study, we showed that elevated tumor tissue TIMP-1 levels were significantly associated with a poor response to chemotherapy. By using TIMP-1, we identified a group of patients with metastatic breast cancer, which hardly respond to the most frequently used chemotherapy regimes (i.e., cyclophosphamide/methotrexate/5-fluorouracil and anthracyclines).

Clinicopathologic implications of tissue inhibitor of metalloproteinase-1-positive diffuse large B-cell lymphoma

The tissue inhibitor of metalloproteinase-1 (TIMP-1) is a stromal factor that promotes plasmablastic differentiation, and the survival of germinal center B-cells. The expression of TIMP-1 is known to be correlated with a subset of non-Hodgkin lymphoma at the mRNA level, and Epstein-Barr virus infection in vitro. To characterize TIMP-1(+) diffuse large B-cell lymphoma, TIMP-1 expression was investigated in tissue microarrays from 182 cases of de novo diffuse large B-cell lymphoma and compared with prognostic factors, immunophenotypes, and Epstein-Barr virus infection status. TIMP-1 was expressed not only in tumor cells themselves, in 14 of 182 cases (8%), designated as TIMP-1(+) diffuse large B-cell lymphoma, but also in stromal cells like fibroblasts and endothelial cells. In univariate analysis and hierarchical clustering, our findings suggest that TIMP-1 expression may represent a distinct subgroup. In multivariate analysis, TIMP-1(+) diffuse large B-cell lymphoma (n=14) was associated with unfavorable outcomes compared to TIMP-1(-) diffuse large B-cell lymphoma (n=168) (odds ratio=2.5, P=0.049). Together with TIMP-1 expression, age (greater than 60 years), the presence of B-symptoms, abnormal lactate dehydrogenase level, or more advanced stage (III/IV) was correlated with a poor overall survival. However, TIMP-1 expression in diffuse large B-cell lymphoma was not correlated with other prognostic factors including: clinical stage, international prognostic index score, and nongerminal center B-cell phenotype, as well as Epstein-Barr virus infection. Our results suggest that TIMP-1 expression may be an independent negative prognostic factor in patients with diffuse large B-cell lymphoma.

Antiprotease therapy in cancer: hot or not?

The activity of a set of peptidases (proteases) involved in cancer progression is collectively known as the cancer 'degradome'. Invasion and metastasis were initially considered as late events in cancer development and the processes in which proteases were involved. However, recent studies indicate that invasion and metastasis are not late events, but can occur during early stages as well. Moreover, other processes occurring in various stages of cancer progression are also protease-dependent, such as (upregulation of) cell proliferation, (downregulation of) apoptosis, involvement of white blood cells, angiogenesis and induction of multi-drug resistance. Proteolytic activity in tumours is regulated in a complex manner, as both genetically unstable cancer cells and stable stromal cells, such as fibroblasts, endothelial cells and inflammatory cells, are involved. In vitro studies and studies using animal models have clearly shown protease dependency of many processes in carcinogenesis. However, clinical trials using protease inhibitors have thus far been unsuccessful except for a few applications of matrix metalloprotease (MMP) inhibitors when used in combination with cytostatic anticancer agents and/or in the early stages of cancer. Antithrombotics, such as low-molecular-weight heparin and warfarin, were also successful in clinical trials, probably by interfering with proteases of the coagulation cascade. The two-way association between cancer and thrombosis has long been recognised in the clinic. The poor outcome of other clinical trials of protease inhibitors is probably due to the late stages of cancer of the patient populations included, and the limited understanding of the complex regulation and effects of the activity of the various proteases in tumours depending on, among others, tumour type and stage, interactions between the cancer cells, other cells and the extracellular matrix in tumours. Therefore, a better fundamental understanding of the proteolytic complexity in tumours is essential before clinical trials can be rationally designed. At present, antithrombotics, the urokinase-type plasminogen activator system, the membrane-bound membrane-type 1-MMP, cathepsin L and the proteasome seem the most promising candidates as targets for anticancer strategies in early stages of cancer in combination with cytotoxic drugs. Moreover, metronomic therapy is an attractive approach using low doses of inhibitors for prolonged periods of time without interruption to specifically target endothelial cells that are involved in angiogenesis.

Method optimisation for peptide profiling of microdissected breast carcinoma tissue by matrix-assisted laser desorption/ionisation-time of flight and matrix-assisted laser desorption/ionisation-time of flight/time of flight-mass spectrometry

Appropriate methods for the analysis of microdissected solid tumour tissues by matrix-assisted laser desorption/ionisation-time of flight-mass spectrometry (MALDI-TOF MS) are not yet well established. Optimisation of sample preparation was performed first on undissected tissue slices, representing approximately 200 000 cells, which were solubilised either in urea containing buffer, trifluoroethanol/NH4HCO3, 0.1% sodium dodecyl sulphate (SDS) or in 0.1% RapiGest solution, then trypsin digested and analysed by MALDI-TOF MS. Solubilisation in 0.1% SDS resulted in detection of the highest number of sample specific peak signals. Interestingly, there was little overlap in detectable peaks using the different buffers, implying that they can be used complementarily to each other. Additionally, we fractionated tryptic digests on a monolithic high-performance liquid chromatography column. Fractionation of tryptic digest from whole tissue sections resulted in a four-fold increase in the total number of peaks detected. To prove this principle, we used 0.1% SDS to generate peptide patterns from 2000 microdissected tumour and stromal cells from five different breast carcinoma tumours. The tumour and stroma specific peaks could be detected upon comparison of the peptide profiles. Identification of differentially expressed peaks by MALDI-TOF/TOF MS was performed on fractionated tryptic digests derived from a whole tissue slice. In conclusion, we describe a method that is suitable for direct peptide profiling on small amounts of microdissected cells obtained from breast cancer tissues.

Measurement of the Uncomplexed Fraction of Tissue Inhibitor of Metalloproteinases-1 in the Prognostic Evaluation of Primary Breast Cancer Patients*

Several studies have demonstrated an association between high tumor tissue levels of total tissue inhibitor of metalloproteinases-1 (TIMP-1) and a poor prognosis of primary breast cancer patients. In the present study we investigated whether measurements of the uncomplexed fraction of TIMP-1 added prognostic information to that already obtained from total TIMP-1. We measured the uncomplexed fraction of TIMP-1, using a thoroughly validated ELISA specific for this fraction, in 341 tumor tissue extracts obtained from patients with primary breast cancer. These measurements were related to previously performed measurements of total TIMP-1 as well as to patient outcome. The observation time was 8.3 years (range, 7.3-11.3 years). During this period 136 patients died, and 153 patients experienced recurrence of disease. Cox regression analysis of recurrence-free survival (RFS) suggested that a score based on both uncomplexed and total TIMP-1, reflecting the tumor level of TIMP-1/MMP complexes, would be a more precise estimate of prognosis than total TIMP-1 alone. Univariate survival analysis showed a highly significant relationship between high values of the score and poor outcomes for RFS (p = 0.0002; hazard ratio = 2.7; 95% confidence interval, 1.5-4.8). Similar results were found for overall survival (p = 0.0001; hazard ratio = 3.3; 95% confidence interval, 1.8-6.3). Multivariate analysis of RFS and overall survival demonstrated that the score was significant including the classical prognostic factors used in breast cancer (p < 0.0001). The present study raises the hypothesis that it is the tumor level of TIMP-1/MMP complexes (i.e. activated matrix metalloproteinases) rather than TIMP-1 itself that determines prognosis, supporting the use of the combined score and not only total TIMP-1 in stratification of breast cancer patients.

Establishment and Characterization of 7 New Monoclonal Antibodies to Tissue Inhibitor of Metalloproteinases-1

Tissue inhibitor of metalloproteinases-1 (TIMP-1) plays a pivotal role in tissue remodeling processes, such as inflammation, wound healing and cancer invasion. Experimental results have pointed to a role in angiogenesis, cell proliferation, apoptosis and in malignant transformation. In clinical investigations high tumor tissue or plasma levels of TIMP-1 have been shown to have a strong and independent association with shorter survival time for breast and colorectal cancer patients, respectively. The purpose of this study has been to develop and characterize new anti-TIMP-1 monoclonal antibodies that may be useful in future development of TIMP-1 immunoassays.Peptide-based epitope mapping reveals linear epitopes. Surface plasmon resonance was used to determine antibody affinity and ability of antibodies to sandwich with each other. Antigen recognition was tested using ELISA and a chemiluminescence microtiter immunoassay format. Three antibodies recognized linear peptides. Estimated antibody affinities for TIMP-1 ranged from 6.6 x 10(8) to>10(10) 1/M. Antibodies demonstrated different abilities in 'capture' and 'detection' positions in the sandwich experiment. All antibody pairs bound TIMP-1:ProMMP-9 complexes. TIMP-1:MMP-9 complexes were marginally reactive with five antibody pairs. The results suggest that the antibodies are unique. They may be useful in designing assays that recognize various forms of TIMP-1. Future studies will clarify whether the use of different combinations of antibodies will increase the clinical value of TIMP-1 measurements in the treatment of cancer patients.