Functional analysis of matrix metalloproteinases and tissue inhibitors of metalloproteinases differentially expressed by variants of human HT-1080 fibrosarcoma exhibiting high and low levels of intravasation and metastasis

MicroRNA mediated regulation of oxidative stress and cytokines in Chlamydia trachomatis-infected recurrent spontaneous abortion: A case-control study

PROBLEM

Increased oxidative stress (OS) and inflammatory responses are major underlying factors behind Chlamydia trachomatis-associated recurrent spontaneous abortion (RSA). miRNAs are known to regulate inflammation and OS and their dysregulation has been associated with compromised pregnancies. Therefore, aim of this study was to investigate the expression/correlation of OS biomarkers, cytokines and miRNAs in C. trachomatis-associated RSA.

METHOD OF STUDY

Urine and non-heparinized blood samples were collected from RSA patients with history of >3 consecutive abortions (cases) and non-pregnant women with history of >2 successful deliveries (controls) attending Department of Obstetrics and Gynaecology, Safdarjung hospital, New Delhi. C. trachomatis detection was done in urine by PCR. miRNA expression was studied by microarray analysis and validated by real time-PCR. Evaluation of cytokines and antioxidant genes expression were done by real-time PCR. Level of OS biomarkers 8-hydroxy guanosine (8-OHdG) and 8-isporostane (8-IP) were measured by ELISA.

RESULTS

Fifty circulating miRNAs were differentially expressed in infected patients compared with controls. Of these, four were overexpressed and 46 downregulated. Thirteen differentially expressed circulating miRNAs were selected to validate microarray results. miRs-8069, -3663-3p showed maximum upregulation/downregulation in infected versus control group. Expression of cytokines (IL-8, TNF-α, IFN-γ), antioxidant genes SOD2 and OS biomarkers (8-OHdG,8-IP) were increased while SOD1 was decreased in infected patients. miR-8069 showed significant positive correlation with cytokines, SOD2, 8-OHdG and 8-IP. miR-3663-3p showed significant positive correlation with SOD1.

CONCLUSIONS

Overall results indicate circulating miRNAs are involved in pathogenesis of C. trachomatis-associated RSA and are potential modulators of cytokine signalling and OS in infected RSA.

Progesterone-mediated immunoregulation of cytokine signaling by miRNA-133a and 101-3p in Chlamydia trachomatis-associated recurrent spontaneous abortion

miRNAs regulate the expression of various genes involved in cellular and metabolic pathways in pregnancy related complications including recurrent spontaneous abortion (RSA). Modulation of progesterone and associated pro-inflammatory cytokines by miRNAs in Chlamydia trachomatis-associated RSA is still under investigation. Present study aimed to evaluate the expression/correlation of serum-circulating miRNAs-133a, 101-3p, 320b, 146b-5p, 24, 559, progesterone and few cytokines in C. trachomatis-positive spontaneous aborters. Non-heparinized blood and urine was collected from 120 patients with history of RSA (Group I) and 120 patients with ≥ 2 successful deliveries (Group II) attending Department of Obstetrics and Gynecology, Safdarjung hospital, New Delhi, India. C. trachomatis detection was performed by PCR and chlamydial load by real time PCR. Progesterone concentration was estimated by ELISA. miRNAs and cytokine expression was studied by quantitative real-time PCR and correlated with progesterone expression. Twenty six patients were found to be positive for C. trachomatis. miRNAs- 133a, 101-3p showed maximum upregulation in infected versus control patients. miRNA expression showed positive correlation with chlamydial load. Progesterone concentration showed significant decrease while cytokines (IL-6, IFN-γ, TNF-α) were significantly upregulated in C. trachomatis-positive patients. Positive correlation was observed between expression of miRNAs-133a and 101-3p and cytokines while negative correlation was observed with progesterone in infected RSA patients. Correlation between progesterone and cytokines was found to be significantly negative in infected RSA patients. Although further validation is required, the study concludes that miR-133a and 101-3p are of clinical importance and have a role in immunoregulation of progesterone and cytokines in infection associated RSA.

Immune regulation by activation markers at feto-maternal interface in infection-associated spontaneous preterm birth

BACKGROUND

Spontaneous preterm birth (sPTB) is a global health concern. Studies reveal infections are majorly responsible for sPTB and immune activation markers play a role in regulation of maternal immune responses against pathogens during sPTB.

AIM

To study the mRNA expression and correlation of activation markers (CD66a, ICAM1, ITGB1, TIM3, CD25, CD95) and associated cytokines (IL-1β and IL-17)/prostaglandin receptors (EP2 and IP) in the placenta of Chlamydia trachomatis, Mycoplasma hominis, Ureaplasma urealyticum-infected sPTB women.

METHODS

Placental samples were collected from 160 sPTB and 160 term birth women. PCR was used for the detection of C. trachomatis, M. hominis, U. urealyticum. The mRNA expression of activation markers, cytokines and prostaglandin receptors was evaluated by real-time qPCR.

RESULTS

The fold-change expression of CD66a, ICAM1, TIM3, CD25 and CD95 was 2.89, 5.5, 4.95, 6.44 and 6.95-fold (p < 0.001), respectively; while for cytokines- IL-1β and IL-17 was 5.41 and 4.71-fold (p < 0.001), respectively and for prostaglandin receptors- EP2 and IP was 5.5 and 5-fold (p < 0.001) upregulated, respectively in infected sPTB women. Significant positive correlation was obtained among ICAM-1 and IL-1β/EP2/IL-17, TIM3 and IP/IL-17. Significant negative correlation was obtained between CD66a and EP2/IL-17, CD25 and IL-1β/EP2, CD95 and IL-1β/EP2 in infected sPTB women.

CONCLUSIONS

CD66a, ICAM1 and TIM3 may play role in inflammation and have potential for the clinical beginning of preterm labour during infection while CD25 and CD95 are possibly involved in immunotolerance at feto-maternal interface during C. trachomatis, M. hominis and U. urealyticum infection.

Immunomodulation of cytokine signalling at feto-maternal interface by microRNA-223 and -150-5p in infection-associated spontaneous preterm birth

Spontaneous preterm birth (sPTB) is a global health concern and it is the most prevalent cause of infant mortality and morbidity with occurrence rate of 5 - 18% worldwide. Studies suggest infection and infection-driven activation of inflammatory responses are the potential risk factors for sPTB. MicroRNAs (miRNAs) are thought to control the expression of several immune genes, making them crucial components of the intricate immune regulatory network and the dysregulation of miRNAs in placenta has been associated to several pregnancy-related complications. However, studies on possible role of miRNAs in immunomodulation of cytokine signalling in infection-associated sPTB are scarce. Present study aimed to investigate expression/ correlation of a few circulating miRNAs (miR-223, -150-5p, -185-5p, -191-5p), miRNA target genes and associated cytokines in sPTB women found infected with Chlamydia trachomatis/ Mycoplasma hominis/ Ureaplasma urealyticum. Non-heparinized blood and placental sample were collected from 140 sPTB and 140 term women visiting Safdarjung hospital, New Delhi (India) for conducting PCR and RT-PCR for pathogen detection and miRNA/ target gene/ cytokine expression, respectively. Common target genes of differentially expressed miRNAs were obtained from databases. The correlation between select target genes/ cytokines and serum miRNAs was determined by Spearman's rank correlation. 43 sPTB were infected with either pathogen and a significant upregulation of serum miRNAs was observed. However, miR-223 and 150-5p showed maximum fold-change (4.78 and 5.58, respectively) in PTB versus control group. IL-6ST, TGF-β R3 and MMP-14 were important target genes among 454 common targets, whereas, IL-6 and TGF-β were associated cytokines. miR-223 and 150-5p showed significant negative correlation with IL-6ST/ IL-6/ MMP-14 and positive correlation with TGF-β R3/ TGF-β. A significant positive correlation was found between IL-6ST and IL-6, TGF-β R3 and TGF-β. However, miR-185-5p and 191-5p were not significantly correlated. Although post-transcriptional validation is required, yet on the basis of mRNA findings, the study concludes that miR-223 and 150-5p are apparently of clinical importance in regulation of inflammatory processes during infection-associated sPTB.

Galectins are critical regulators of cytokine signalling at feto-maternal interface in infection-associated spontaneous preterm birth

INTRODUCTION

Spontaneous preterm birth (sPTB) is a global health issue. Studies suggest infections are chiefly associated with sPTB and galectins (gals) play a role in regulation of innate and adaptive maternal immune response against pathogens during sPTB. The aim of this study was to describe the gene expression of gal -1, -3, -8, -9, -13 in relation to gene expression of cyclooxygenase-2 (COX-2) and the cytokines IL-8, IL-10, TNF-α, IFN-ϒ in the setting of sPTB and confirmed infection with Chlamydia trachomatis, Mycoplasma hominis, and Ureaplasma urealyticum.

METHODS

Placental samples were collected from 120 term control and 120 sPTB pregnancies. PCR was used to detect specific pathogens. Gene expression of galectins, cytokines, and COX-2 was performed using real time qPCR.

RESULTS

Fold-change expression of gal -1, -3, -8, -9, -13 was 5.13, 6.11, 1.14, 5.23 and 7.16 (p<0.001), respectively; while IL-10, IL-8, TNF-α, IFN-ϒ and COX-2 was 6.29, 6.55, 6.35, 6.36 and 2.73-fold upregulated (p<0.05), respectively in infected sPTB. Gal-1 was positively correlated with IL-10 (r=0.49, p=0.003) while gal-3 showed significant correlation with IL-8 (r=0.42, p=0.0113), TNF-α (r=0.65, p=< 0.001) and COX-2 (r=0.72, p=0.001). However, gal-8 was not significantly correlated with any cytokine. Gal-9, -13 were negatively correlated with IFN-ϒ (r=-0.45, p=0.006) and IL-8 (r=-0.39, p=0.018).

DISCUSSION

Gal-1, -9, -13 are anti-inflammatory and might play role in immune-tolerance while gal-3 is pro-inflammatory and possibly responsible for immunogenic response, having potential to anticipate the clinical beginning of preterm labour during infection.

Phytochemical Profiling and Assessment of Anticancer Activity of Leptocarpha rivularis Extracts Obtained from In Vitro Cultures

Plant cell culture is a source of plant material from which bioactive metabolites can be extracted. In this work, the in vitro propagation of Leptocarpha rivularis, an endemic Chilean shrub with anticancer activity, is described. Different media were tested and optimized for the introduction, propagation, and rooting steps of the micropropagation process. At the end of this process, 83% of plants were successfully acclimatized under greenhouse conditions. Callus induction from the internodal stem segment was performed using various combinations of phytohormones. Green-colored, friable, and non-organogenic callus was generated with a callus induction index higher than 90%. The chemical composition of extracts and callus, obtained from clonal plants, was assessed and the results indicate that the phytochemical profiles of extracts from micropropagated plants are like those found for plants collected from natural habitats, leptocarpine (LTC) being the major component. However, no LTC was detected in callus extract. HeLa and CoN cells, treated with LTC or extract of micropropagated plants, exhibit important diminution on cell viability and a drastic decrease in gene expression of IL-6 and mmp2, genes associated with carcinogenic activity. These effects are more important in cancer cells than in normal cells. Thus, micropropagated L. rivularis could be developed as a potential source of efficient antiproliferative agents.

The Role of MMP8 in Cancer: A Systematic Review

Matrix metalloproteinases (MMPs) have traditionally been considered as tumor promoting enzymes as they degrade extracellular matrix components, thus increasing the invasion of cancer cells. It has become evident, however, that MMPs can also cleave and alter the function of various non-matrix bioactive molecules, leading to both tumor promoting and suppressive effects. We applied systematic review guidelines to study MMP8 in cancer including the use of MMP8 as a prognostic factor or as a target/anti-target in cancer treatment, and its molecular mechanisms. A total of 171 articles met the inclusion criteria. The collective evidence reveals that in breast, skin and oral tongue cancer, MMP8 inhibits cancer cell invasion and proliferation, and protects patients from metastasis via cleavage of non-structural substrates. Conversely, in liver and gastric cancers, high levels of MMP8 worsen the prognosis. Expression and genetic alterations of MMP8 can be used as a prognostic factor by examination of the tumor and serum/plasma. We conclude, that MMP8 has differing effects on cancers depending on their tissue of origin. The use of MMP8 as a prognostic factor alone, or with other factors, seems to have potential. The molecular mechanisms of MMP8 in cancer further emphasize its role as an important regulator of bioactive molecules.

Matrix metalloproteinases participation in the metastatic process and their diagnostic and therapeutic applications in cancer

Matrix metalloproteinases (MMPs) participate from the initial phases of cancer onset to the settlement of a metastatic niche in a second organ. Their role in cancer progression is related to their involvement in the extracellular matrix (ECM) degradation and in the regulation and processing of adhesion and cytoskeletal proteins, growth factors, chemokines and cytokines. MMPs participation in cancer progression makes them an attractive target for cancer therapy. MMPs have also been used for theranostic purposes in the detection of primary tumor and metastatic tissue in which a particular MMP is overexpressed, to follow up on therapy responses, and in the activation of cancer cytotoxic pro-drugs as part of nano-delivery-systems that increase drug concentration in a specific tumor target. Herein, we review MMPs molecular characteristics, their synthesis regulation and enzymatic activity, their participation in the metastatic process, and how their functions have been used to improve cancer treatment.

Intratumoral Cancer Cell Intravasation Can Occur Independent of Invasion into the Adjacent Stroma

Intravasation, active entry of cancer cells into the circulation, is often considered to be a relatively late event in tumor development occurring after stromal invasion. Here, we provide evidence that intravasation can be initiated early during tumor development and proceed in parallel to or independent of tumor invasion into surrounding stroma. By applying direct and unbiased intravasation-scoring methods to two histologically distinct human cancer types in live-animal models, we demonstrate that intravasation takes place almost exclusively within the tumor core, involves intratumoral vasculature, and does not involve vasculotropic cancer cells invading tumor-adjacent stroma and migrating along tumor-converging blood vessels. Highlighting an additional role for EGFR in cancer, we find that EGFR is required for the development of an intravasation-sustaining intratumoral vasculature. Intratumoral localization of intravasation supports the notion that overt metastases in cancer patients could be initiated much earlier during cancer progression than appreciated within conventional clinical tumor staging systems.

EGFR regulates the development and microarchitecture of intratumoral angiogenic vasculature capable of sustaining cancer cell intravasation

Many malignant characteristics of cancer cells are regulated through pathways induced by the tyrosine kinase activity of the epidermal growth factor receptor (EGFR). Herein, we show that besides directly affecting the biology of cancer cells per se, EGFR also regulates the primary tumor microenvironment. Specifically, our findings demonstrate that both the expression and signaling activity of EGFR are required for the induction of a distinct intratumoral vasculature capable of sustaining tumor cell intravasation, a critical rate-limiting step in the metastatic cascade. An intravasation-sustaining mode of intratumoral angiogenic vessels depends on high levels of tumor cell EGFR and the interplay between EGFR-regulated production of interleukin 8 by tumor cells, interleukin-8–induced influx of tumor-infiltrating neutrophils delivering their unique matrix metalloproteinase-9, and neutrophil matrix metalloproteinase-9–dependent release of the vascular permeability and endothelial growth factor, VEGF. Our data indicate that through VEGF-mediated disruption of endothelial layer integrity and increase of intratumoral vasculature permeability, EGFR activity significantly facilitates active intravasation of cancer cells. Therefore, this study unraveled an important but overlooked function of EGFR in cancer, namely, its ability to create an intravasation-sustaining microenvironment within the developing primary tumor by orchestrating several interrelated processes required for the initial steps of cancer metastasis through vascular routes. Our findings also suggest that EGFR-targeted therapies might be more effective when implemented in cancer patients with early-staged primary tumors containing a VEGF-dependent angiogenic vasculature. Accordingly, early EGFR inhibition combined with various anti-VEGF approaches could synergistically suppress tumor cell intravasation through inhibiting the highly permeable angiogenic vasculature induced by EGFR-overexpressing aggressive cancer cells.

Tumor angiogenesis: MMP-mediated induction of intravasation- and metastasis-sustaining neovasculature

Metastasis is a distinct stage of cancer progression that requires the development of angiogenic blood vessels serving as conduits for tumor cell dissemination. An accumulated body of evidence indicates that metastasis-supporting neovasculature should possess certain structural characteristics allowing for the process of tumor cell intravasation, an active entry of cancer cells into the vessel interior. It appears that the development of tumor vessels with lumens of a distinctive size and support of these vessels by a discontinuous pericyte coverage constitute critical microarchitectural requirements to: (a) provide accessible points for vessel wall penetration by primary tumor cells; (b) provide enough lumen space for a tumor cell or cell aggregate upon intravasation; and (c) allow for sufficient rate of blood flow to carry away intravasated cells from the primary tumor to the next, proximal or distal site. This review will primarily focus on the functional roles of matrix metalloproteinases (MMPs), which catalytically trigger the development of an intravasation-sustaining neovasculature at the early stages of tumor growth and are also required for the maintenance of a metastasis-supporting state of blood vessels at later stages of cancer progression.

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.

Targeting androgen receptor/Src complex impairs the aggressive phenotype of human fibrosarcoma cells

Background

Hormones and growth factors influence the proliferation and invasiveness of human mesenchymal tumors. The highly aggressive human fibrosarcoma HT1080 cell line harbors classical androgen receptor (AR) that responds to androgens triggering cell migration in the absence of significant mitogenesis. As occurs in many human cancer cells, HT1080 cells also express epidermal growth factor receptor (EGFR).

Experimental

Findings: We report that the pure anti-androgen Casodex inhibits the growth of HT1080 cell xenografts in immune-depressed mice, revealing a novel role of AR in fibrosarcoma progression. In HT1080 cultured cells EGF, but not androgens, robustly increases DNA synthesis. Casodex abolishes the EGF mitogenic effect, implying a crosstalk between EGFR and AR. The mechanism underlying this crosstalk has been analyzed using an AR-derived small peptide, S1, which prevents AR/Src tyrosine kinase association and androgen-dependent Src activation. Present findings show that in HT1080 cells EGF induces AR/Src Association, and the S1 peptide abolishes both the assembly of this complex and Src activation. The S1 peptide inhibits EGF-stimulated DNA synthesis, cell matrix metalloproteinase-9 (MMP-9) secretion and invasiveness of HT1080 cells. Both Casodex and S1 peptide also prevent DNA synthesis and migration triggered by EGF in various human cancer-derived cells (prostate, breast, colon and pancreas) that express AR.

Conclusion

This study shows that targeting the AR domain involved in AR/Src association impairs EGF signaling in human fibrosarcoma HT1080 cells. The EGF-elicited processes inhibited by the peptide (DNA synthesis, MMP-9 secretion and invasiveness) cooperate in increasing the aggressive phenotype of HT1080 cells. Therefore, AR represents a new potential therapeutic target in human fibrosarcoma, as supported by Casodex inhibition of HT1080 cell xenografts. The extension of these findings in various human cancer-derived cell lines highlights the conservation of this process across divergent cancer cells and identifies new potential targets in the therapeutic approach to human cancers.

Tumor MMP-1 activates endothelial PAR1 to facilitate vascular intravasation and metastatic dissemination

Intravasation, the active entry of primary tumor cells into the vasculature, remains the least studied step in the metastatic cascade. Protease-mediated escape and stromal invasion of tumor cells represent widely accepted processes leading up to the intravasation step. However, molecular factors that contribute directly to tumor cell vascular penetration have not been identified. In this study, the in vivo role of the collagenolytic protease, MMP-1, in cancer cell intravasation and metastasis was analyzed by using a highly disseminating variant of human HEp3 epidermoid carcinoma, HEp3-hi/diss. Although naturally acquired or experimentally induced MMP-1 deficiency substantially suppressed HEp3-hi/diss intravasation, supplementation of recombinant MMP-1 to MMP-1-silenced primary tumors restored their impaired vascular dissemination. Surprisingly, abrogation of MMP-1 production and activity did not significantly affect HEp3-hi/diss migration or matrix invasion, suggesting noncollagenolytic mechanisms underlying MMP-1-dependent cell intravasation. In support of such noncollagenolytic mechanisms, MMP-1 silencing in HEp3-hi/diss cells modulated the microarchitecture and integrity of the angiogenic vasculature in a novel microtumor model. Concomitantly, MMP-1 deficiency led to decreased levels of intratumoral vascular permeability, tumor cell intravasation, and metastatic dissemination. Taking advantage of PAR1 deficiency of HEp3-hi/diss cells, we further show that endothelial PAR1 is a putative nontumor-cell/nonmatrix target, activation of which by carcinoma-produced MMP-1 regulates endothelial permeability and transendothelial migration. The inhibitory effects of specific PAR1 antagonists in live animals have also indicated that the mechanisms of MMP-1-dependent vascular permeability in tumors involve endothelial PAR1 activation. Together, our findings mechanistically underscore the contribution of a tumor MMP-1/endothelial PAR1 axis to actual intravasation events manifested by aggressive carcinoma cells.

The microtubule stabilizer patupilone counteracts ionizing radiation-induced matrix metalloproteinase activity and tumor cell invasion

Background

Ionizing radiation (IR) in combination with microtubule stabilizing agents (MSA) is a promising combined treatment modality. Supra-additive treatment responses might result from direct tumor cell killing and cooperative indirect, tumor cell-mediated effects on the tumor microenvironment. Here we investigated deregulation of matrix metalloproteinase (MMP) activity, as an important component of the tumor microenvironment, by the combined treatment modality of IR with the clinically relevant MSA patupilone.

Methods

Expression, secretion and activity of MMPs and related tissue inhibitors of metalloproteinases (TIMPs) were determined in cell extracts and conditioned media derived from human fibrosarcoma HT1080 and human glioblastoma U251 tumor cells in response to treatment with IR and the MSA patupilone. Treatment-dependent changes of the invasive capacities of these tumor cell lines were analysed using a Transwell invasion assay. Control experiments were performed using TIMP-directed siRNA and TIMP-directed inhibitory antibodies.

Results

Enzymatic activity of secreted MMPs was determined after treatment with patupilone and irradiation in the human fibrosarcoma HT1080 and the human glioblastoma U251 tumor cell line. IR enhanced the activity of secreted MMPs up to 2-fold and cellular pretreatment with low dose patupilone (0.05-0.2 nM) counteracted specifically the IR-induced MMP activity. The cell invasive capacity of HT1080 and U251 cells was increased after irradiation with 2 Gy by 30% and 50%, respectively, and patupilone treatment completely abrogated IR-induced cell invasion. Patupilone did not alter the level of MMP expression, but interestingly, the protein level of secreted TIMP-1 and TIMP-2 was lower after combined treatment than after irradiation treatment alone. Furthermore, siRNA depletion of TIMP-1 or TIMP-2 prevented IR-mediated induction of MMP activity and cell invasion.

Conclusions

These results indicate that patupilone counteracts an IR-induced MMP activation process by the reduction of secreted TIMP-1 and TIMP-2 proteins, which are required for activation of MMPs. Since IR-induced MMP activity could contribute to tumor progression, treatment combination of IR with patupilone might be of great clinical benefit for tumor therapy.

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.

Extracellular matrix determinants of proteolytic and non-proteolytic cell migration

Cell invasion into the 3D extracellular matrix (ECM) is a multistep biophysical process involved in inflammation, tissue repair, and metastatic cancer invasion. Migrating cells navigate through tissue structures of complex and often varying physicochemical properties, including molecular composition, porosity, alignment and stiffness, by adopting strategies that involve deformation of the cell and engagement of matrix-degrading proteases. We review how the ECM determines whether or not pericellular proteolysis is required for cell migration, ranging from protease-driven invasion and secondary tissue destruction, to non-proteolytic, non-destructive movement that solely depends on cell deformability and available tissue space. These concepts call for therapeutic targeting of proteases to prevent invasion-associated tissue destruction rather than the migration process per se.

Regulation of macrophage migration by a novel plasminogen receptor Plg-R KT

Localization of plasmin on macrophages and activation of pro-MMP-9 play key roles in macrophage recruitment in the inflammatory response. These functions are promoted by plasminogen receptors exposing C-terminal basic residues on the macrophage surface. Recently, we identified a novel transmembrane plasminogen receptor, Plg-R(KT), which exposes a C-terminal lysine on the cell surface. In the present study, we investigated the role of Plg-R(KT) in macrophage invasion, chemotactic migration, and recruitment. Plg-R(KT) was prominently expressed in membranes of human peripheral blood monocytes and monocytoid cells. Plasminogen activation by urokinase-type plasminogen activator (uPA) was markedly inhibited (by 39%) by treatment with anti-Plg-R(KT) mAb. Treatment of monocytes with anti-Plg-R(KT) mAb substantially inhibited invasion through the representative matrix, Matrigel, in response to MCP-1 (by 54% compared with isotype control). Furthermore, chemotactic migration was also inhibited by treatment with anti-Plg-R(KT) mAb (by 64%). In a mouse model of thioglycollate-induced peritonitis, anti-Plg-R(KT) mAb markedly inhibited macrophage recruitment (by 58%), concomitant with a reduction in pro-MMP-9 activation in the inflamed peritoneum. Treatment with anti-Plg-R(KT) mAb did not further reduce the low level of macrophage recruitment in plasminogen-null mice. We conclude that Plg-R(KT) plays a key role in the plasminogen-dependent regulation of macrophage invasion, chemotactic migration, and recruitment in the inflammatory response.

Role of matrix metalloproteinase-9 dimers in cell migration: design of inhibitory peptides

Non-proteolytic activities of matrix metalloproteinases (MMPs) have recently been shown to impact cell migration, but the precise mechanism remains to be understood. We previously demonstrated that the hemopexin (PEX) domain of MMP-9 is a prerequisite for enhanced cell migration. Using a biochemical approach, we now report that dimerization of MMP-9 through the PEX domain appears necessary for MMP-9-enhanced cell migration. Following a series of substitution mutations within the MMP-9 PEX domain, blade IV was shown to be critical for homodimerization, whereas blade I was required for heterodimerization with CD44. Blade I and IV mutants showed diminished enhancement of cell migration compared with wild type MMP-9-transfected cells. Peptides mimicking motifs in the outermost strands of the first and fourth blades of the MMP-9 PEX domain were designed. These peptides efficiently blocked MMP-9 dimer formation and inhibited motility of COS-1 cells overexpressing MMP-9, HT-1080, and MDA-MB-435 cells. Using a shRNA approach, CD44 was found to be a critical molecule in MMP-9-mediated cell migration. Furthermore, an axis involving a MMP-9-CD44-EGFR signaling pathway in cell migration was identified using antibody array and specific receptor tyrosine kinase inhibitors. In conclusion, we dissected the mechanism of pro-MMP-9-enhanced cell migration and developed structure-based inhibitory peptides targeting MMP-9-mediated cell migration.

Mechanism-based profiling of MMPs

The recognition that the successful clinical use of MMP inhibitors will require quantitative correlation of MMP activity with disease type, and to disease progression, has stimulated intensive effort toward the development of sensitive assay methods, improved analytical methods for the determination of the structural profile for MMP-sub-type inhibition, and the development of new methods for the determination - in both quantitative and qualitative terms - of MMP activity. This chapter reviews recent progress toward these objectives, with particular emphasis on the quantitative and qualitative profiling of MMP activity in cells and tissues. Quantitative determination of MMP activity is made from the concentration of the MMP from the tissue, using immobilization of a broad-spectrum MMP inhibitor on a chromatography resin. Active MMP, to the exclusion of MMP zymogens and endogenous TIMP-inhibited MMPs, is retained on the column. Characterization of the MMP sub-type(s) follows from appropriate analysis of the active MMP eluted from the resin. Qualitative determination of MMP involvement in disease can be made using an MMP sub-type-selective inhibitor. The proof of principle, with respect to this qualitative determination of the disease involvement of the gelatinase MMP-2 and MMP-9 sub-types, is provided by the class of thiirane-based MMP mechanism-based inhibitors (SB-3CT as the prototype). Positive outcomes in animal models of disease having MMP-2 and/or -9 dependency follow administration of this MMP inhibitor, whereas this inhibitor is inactive in disease models where other MMPs (such as MMP-14) are involved.

The regulatory mechanism of Hsp90alpha secretion and its function in tumor malignancy

Heat shock protein 90-alpha (Hsp90alpha) is an intracellular molecular chaperone. However, it can also be secreted with the underlying regulatory mechanism remaining far from clear. Here we show that the secreted Hsp90alpha is a C-terminal truncated form and its secretion is regulated by the C-terminal EEVD motif via interacting with proteins containing tetratricopeptide repeat domains. We also demonstrate that secretion of Hsp90alpha is determined by the phosphorylation status at residue Thr-90, regulated by protein kinase A and protein phosphatase 5. We further demonstrate that the secretion of Hsp90alpha is a prerequisite for its proinvasiveness function and blocking the secreted Hsp90alpha results in significant inhibition of tumor metastasis. Meanwhile, the level of plasma Hsp90alpha is positively correlated with tumor malignancy in clinical cancer patients. In sum, our results reveal the regulatory mechanism of Hsp90alpha secretion, and its function in tumor invasiveness, indicating it can be a promising diagnostic marker for tumor malignancy in clinical application.

The regulatory mechanism of Hsp90alpha secretion and its function in tumor malignancy

Heat shock protein 90-alpha (Hsp90alpha) is an intracellular molecular chaperone. However, it can also be secreted with the underlying regulatory mechanism remaining far from clear. Here we show that the secreted Hsp90alpha is a C-terminal truncated form and its secretion is regulated by the C-terminal EEVD motif via interacting with proteins containing tetratricopeptide repeat domains. We also demonstrate that secretion of Hsp90alpha is determined by the phosphorylation status at residue Thr-90, regulated by protein kinase A and protein phosphatase 5. We further demonstrate that the secretion of Hsp90alpha is a prerequisite for its proinvasiveness function and blocking the secreted Hsp90alpha results in significant inhibition of tumor metastasis. Meanwhile, the level of plasma Hsp90alpha is positively correlated with tumor malignancy in clinical cancer patients. In sum, our results reveal the regulatory mechanism of Hsp90alpha secretion, and its function in tumor invasiveness, indicating it can be a promising diagnostic marker for tumor malignancy in clinical application.

Comparative analysis of metastasis variants derived from human prostate carcinoma cells: roles in intravasation of VEGF-mediated angiogenesis and uPA-mediated invasion

To analyze the process of tumor cell intravasation, we used the human tumor-chick embryo spontaneous metastasis model to select in vivo high (PC-hi/diss) and low (PC-lo/diss) disseminating variants from the human PC-3 prostate carcinoma cell line. These variants dramatically differed in their intravasation and dissemination capacities in both chick embryo and mouse spontaneous metastasis models. Concomitant with enhanced intravasation, PC-hi/diss exhibited increased angiogenic potential in avian and murine models. PC-hi/diss angiogenesis and intravasation were dependent on increased secretion of vascular endothelial growth factor (VEGF), since treating developing tumors with a function-blocking anti-VEGF antibody simultaneously inhibited both processes without affecting primary tumor growth. PC-hi/diss cells were also more migratory and invasive, suggestive of heightened ability to escape from primary tumors due to matrix-degrading activity. Consistent with this suggestion, PC-hi/diss cells produced more of the serine protease urokinase-type plasminogen activator (uPA) as compared with PC-lo/diss. The functional role of uPA in PC-hi/diss dissemination was confirmed by inhibition of invasion, angiogenesis, and intravasation with specific function-blocking antibodies that prevented uPA activation and blocked uPA activity. These processes were similarly sensitive to aprotinin, a potent inhibitor of serine proteases, including uPA-generated plasmin. Thus, our comparison of the PC-3 intravasation variants points to key roles for the uPA-plasmin system in PC-hi/diss intravasation, possibly via (1) promoting tumor cell matrix invasion and (2) facilitating development of VEGF-dependent angiogenic blood vessels.

Malignant fibrous histiocytoma--pleomorphic sarcoma, NOS gene expression, histology, and clinical course. A pilot study

PURPOSE

The new classification of malignant fibrous histiocytoma leaves only a small group of tumors without further line of differentiation, so-called pleomorphic sarcomas, not otherwise specified (NOS) as a pseudo-entity. This study focused on these tumors and analyzed the association of gene expression profiles to clinical outcome.

MATERIALS AND METHODS

Ten fresh samples of pleomorphic NOS sarcomas were evaluated histopathologically and by means of microarray analysis. Analysis of expression profiles was performed by clustering methods as well as by statistical analysis of primary vs recurrent tumors, irradiated vs nonirradiated tumors, tumors of patients above and below 60 years of age, male and female, and of tumors that developed metastatic or recurrent disease during the clinical course and those that did not.

RESULTS

Tumor clustering did not correlate to any histopathological or clinical finding. Detailed gene expression analysis showed a variety of genes whose upregulation (platelet-derived growth factor receptor alpha polypeptide, solute carrier family 39 member 14, solute carrier family 2 member 3, pleiotrophin, trophinin, pleckstrin and Sec7 domain containing 3, enolase 2, biglycan, SH3 and cysteine-rich domain, matrix metalloproteinases 16) and whose downregulation (tissue inhibitor of metalloproteinase 4, hairy/enhancer of split related with YRPW motif 2, protein tyrosine phosphatase receptor-type Z polypeptide 1, SH3 domain GRB2-like 2, microtubule-associated protein 7, potassium voltage-gated channel shaker-related subfamily member 1, RUN and FYVE domain containing 3, Sin3A-associated protein 18 kDa, proline-rich 4, calcium/calmodulin-dependent protein kinase ID, myeloid/lymphoid or mixed-lineage leukemia translocated to 3, insulin-like growth factor binding protein 5, nucleoside diphosphate-linked moiety X-type motif 9, NudC domain containing 3, imprinted in Prader-Willi syndrome, TAF6-like RNA polymerase II p300/CBP-associated factor 65 kDa, WD repeat and SOCS box-containing 2, adenosine diphosphate ribosylation factor 3, KRR1, proliferation-associated 2G4; CD36, complement component (3b/4b) receptor 1, solute carrier family 4 sodium bicarbonate cotransporter member 4, lipoprotein lipase (LPL), GATA binding protein 3, LPL, glutathione peroxidase 3, D: -aspartate oxidase, apolipoprotein E, sphingomyelin phosphodiesterase acid-like 3A) were associated with poor clinical outcome in terms of development of metastatic or recurrent disease.

CONCLUSIONS

The classification of these tumors may undergo further changes in the future. Gene expression profiling can provide additional information to categorize pleomorphic sarcoma (NOS) and reveal potential prognostic factors in this "entity."

Supervillin reorganizes the actin cytoskeleton and increases invadopodial efficiency

Tumor cells use actin-rich protrusions called invadopodia to degrade extracellular matrix (ECM) and invade tissues; related structures, termed podosomes, are sites of dynamic ECM interaction. We show here that supervillin (SV), a peripheral membrane protein that binds F-actin and myosin II, reorganizes the actin cytoskeleton and potentiates invadopodial function. Overexpressed SV induces redistribution of lamellipodial cortactin and lamellipodin/RAPH1/PREL1 away from the cell periphery to internal sites and concomitantly increases the numbers of F-actin punctae. Most punctae are highly dynamic and colocalize with the podosome/invadopodial proteins, cortactin, Tks5, and cdc42. Cortactin binds SV sequences in vitro and contributes to the formation of enhanced green fluorescent protein (EGFP)-SV induced punctae. SV localizes to the cores of Src-generated podosomes in COS-7 cells and with invadopodia in MDA-MB-231 cells. EGFP-SV overexpression increases average numbers of ECM holes per cell; RNA interference-mediated knockdown of SV decreases these numbers. Although SV knockdown alone has no effect, simultaneous down-regulation of SV and the closely related protein gelsolin reduces invasion through ECM. Together, our results show that SV is a component of podosomes and invadopodia and that SV plays a role in invadopodial function, perhaps as a mediator of cortactin localization, activation state, and/or dynamics of metalloproteinases at the ventral cell surface.

Cell surface proteomics identifies molecules functionally linked to tumor cell intravasation

In order to better understand the molecular and cellular determinants of tumor cell intravasation, our laboratory has generated a pair of congenic human HT-1080 fibrosarcoma variants (i.e. HT-hi/diss and HT-lo/diss) differing 50-100-fold in their ability to intravasate and disseminate. To investigate the molecular differences underlying the distinct dissemination capacities of these HT-1080 variants, we performed a comparative analysis of the cell surface proteomes of HT-hi/diss and HT-lo/diss. Cell membrane proteins were enriched by biotinylation and avidin precipitation and analyzed by tandem mass spectrometry employing multidimensional protein identification technology. By this approach, 47 cell surface-associated molecules were identified as differentially expressed between the HT-1080 intravasation variants. From these candidates, four targets (i.e. TIMP-2, NCAM-1, JAM-C, and tissue factor (TF)) were selected for further biochemical validation and in vivo functional verification. Western blot analysis of the cell surface enriched fractions confirmed the proteomic array data, demonstrating that, in vitro, TIMP-2 protein was increased in the HT-lo/diss variant, whereas NCAM-1, JAM-C, and TF levels were increased in the HT-hi/diss variant. Corresponding in vivo differences in levels of TIMP-2, JAM-C, and TF were demonstrated in primary tumors grown in the chick embryo. Finally, functional inhibition of one selected protein (i.e. TF) by small interfering RNA silencing or ligation with a function-blocking antibody significantly reduced HT-hi/diss intravasation, thus clearly implicating TF in the early steps of tumor cell dissemination. Overall, our cell surface proteomic analysis provides a powerful tool for identification of specific cell membrane molecules that contribute functionally to intravasation and metastasis in vivo.

Gene transfer of matrix metalloproteinase-9 induces tumor regression of breast cancer in vivo

Matrix metalloproteinases (MMP) are important regulators of angiogenesis and tumor progression by degradation of extracellular matrix. Clinical trials using MMP inhibitors have failed and recent studies suggest that MMPs may in contrast suppress tumor growth. It is not known, however, if MMPs or their inhibitors, tissue inhibitor of metalloproteinases (TIMP), can be used as therapy of established cancer. Here, adenovirus vectors carrying the human genes for MMP-9, TIMP-1, or empty controls were injected intratumorally in breast cancers established in mice supplemented with estradiol and treated with tamoxifen. Microdialysis was used to quantify MMP activity and sampling of endostatin and vascular endothelial growth factor (VEGF) in situ. We show that AdMMP-9 increased MMP activity in vivo, decreased tumor growth rate, and decreased microvessel area significantly. AdMMP-9 therapy resulted in significantly increased levels of endostatin in vivo, whereas VEGF levels were unaffected. As previously shown, tamoxifen exposure by itself increased MMP activity in all treatment groups. Moreover, the combined therapy with AdMMP-9 and tamoxifen further reduced tumor growth and increased the endostatin levels compared with either treatment alone. Gene transfer of TIMP-1 had no effects on tumor progression and counteracted the therapeutic effect of tamoxifen in our breast cancer model. This is the first report showing that overexpression of MMP-9 results in increased generation of antiangiogenic fragments, decreased angiogenesis, and therapeutic effects of established breast cancer.

Matrix metalloproteinase-8 functions as a metastasis suppressor through modulation of tumor cell adhesion and invasion

Collagenase-2 (matrix metalloproteinase-8, MMP-8) is an MMP mainly produced by neutrophils and associated with many inflammatory conditions. We have previously described that MMP-8 plays a protective role in cancer through its ability to regulate the inflammatory response induced by carcinogens. Moreover, it has been reported that experimental manipulation of the expression levels of this enzyme alters the metastatic behavior of human breast cancer cells. In this work, we have used mutant mice deficient in MMP-8 and syngenic melanoma and lung carcinoma tumor cells lines overexpressing this enzyme to further explore the putative antimetastatic potential of MMP-8. We report herein that MMP-8 prevents metastasis formation through the modulation of tumor cell adhesion and invasion. Thus, tumor cells overexpressing MMP-8 have an increased adhesion to extracellular matrix proteins, whereas their invasive ability through Matrigel is substantially reduced when compared with control cells. Analysis of MMP-8 in breast cancer patients revealed that the expression of this metalloproteinase by breast tumors correlates with a lower incidence of lymph node metastasis and confers good prognosis to these patients. On this basis, we propose that MMP-8 is a tumor protective factor, which also has the ability to reduce the metastatic potential of malignant cells in both mice and human.