Infiltrative capacity of T leukemia cell lines: a distinct functional property coupled to expression of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinases-1 (TIMP-1)

Inhibitors of gelatinases (MMP-2 and MMP-9) for the management of hematological malignancies

Matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) are collectively known as gelatinases whereas MMP-2 is gelatinase-A and MMP-9 is termed as gelatinase-B. Gelatinases and other matrix metalloproteinases (MMPs) have long been associated with solid tumor invasion, metastasis and angiogenesis. However, there is paucity of data available regarding the role of gelatinases in hematological malignancies. Recent studies have shown that gelatinases activities or functions are correlated with hematological malignancies. Strategies for designing more specific gelatinase inhibitors like catalytic (CAT) domain inhibitors and hemopexin (PEX) domain inhibitors as well as signaling pathway based or gelatinase expression inhibitors had been reported against hematologic malignant cells. Several substrate based non-selective to non-substrate based relatively selective synthetic matrix metalloproteinase inhibitors (MMPIs) had been developed. Few MMPIs had reached in clinical trials during the period of 1990s-2000s. Unfortunately the anti-tumor and anti-metastatic efficacies of these MMPIs were not justified with patients having several advanced stage solid tumor cancers in any substantial number of clinical trials. Till date not a single MMPI passed phase III clinical trials designed for advanced metastatic cancers due to adverse events as well as lack of ability to show uniformity in disease prolongation. With the best of our knowledge no clinical trial study has been reported with small molecule synthetic inhibitors against hematological malignancies. This review looks at the outcome of clinical trials of MMPIs for advanced stage solid tumors. This can therefore, act as a learning experience for future development of successful gelatinase inhibitors for the management of hematological malignancies.

Beta1 integrin blockade overcomes doxorubicin resistance in human T-cell acute lymphoblastic leukemia

Growing evidence indicates that cell adhesion to extracellular matrix (ECM) plays an important role in cancer chemoresistance. Leukemic T cells express several adhesion receptors of the β1 integrin subfamily with which they interact with ECM. However, the role of β1 integrins in chemoresistance of T-cell acute lymphoblastic leukemia (T-ALL) is still ill defined. In this study, we demonstrate that interactions of human T-ALL cell lines and primary blasts with three-dimensional matrices including Matrigel and collagen type I gel promote their resistance to doxorubicin via β1 integrin. The blockade of β1 integrin with a specific neutralizing antibody sensitized xenografted CEM leukemic cells to doxorubicin, diminished the leukemic burden in the bone marrow and resulted in the extension of animal survival. Mechanistically, Matrigel/β1 integrin interaction enhanced T-ALL chemoresistance by promoting doxorubicin efflux through the activation of the ABCC1 drug transporter. Finally, our findings showed that Matrigel/β1 interaction enhanced doxorubicin efflux and chemoresistance by activating the FAK-related proline-rich tyrosine kinase 2 (PYK2) as both PYK2 inhibitor and siRNA diminished the effect of Matrigel. Collectively, these results support the role of β1 integrin in T-ALL chemoresistance and suggest that the β1 integrin pathway can constitute a therapeutic target to avoid chemoresistance and relapsed-disease in human T-ALL.

Prodigiosin produced by Serratia marcescens inhibits expression of MMP-9 and survivin and promotes caspase-3 activation with induction of apoptosis in acute lymphoblastic leukaemia cells

AIMS

Matrix metalloproteinase-9 (MMP-9) and survivin are involved in several steps of carcinogenesis in acute lymphoblastic leukaemia (ALL). Yet, no MMP-9 and survivin-modulating drugs with low toxicity on normal cells but high efficacy against high MMP-9- and survivin-expressing leukaemia cells have been approved for clinical application in ALL. Prodigiosin, a secondary metabolite of Serratia marcescens, induces apoptosis in different kinds of cancer cells with low toxicity on normal cells. However, little is known about the effects of this compound on the high MMP-9- and survivin-expressing leukaemia cells.

METHODS AND RESULTS

CCRF-CEM cells as a model for high MMP-9- and survivin-expressing ALL cells were treated with 100, 200 and 400 nmol l^-1 prodigiosin after which cell number, proliferation rate, MMP-9 and survivin expression, caspase-3 activation and apoptosis were evaluated. After 24-, 48-, and 72-h treatments with 100, 200 and 400 nmol l^-1 prodigiosin, proliferation rates were measured to be 92·3-76·7%, 82-63% and 63·7-46·6% respectively. Treatment with prodigiosin for 48 h decreased MMP-9 mRNA levels followed by decreases in secreted (S) and intracellular (I) MMP-9 protein levels by 20-22% and 69-72% for 100-400 nmol l^-1 prodigiosin respectively. Prodigiosin decreased survivin protein levels from 40 to 26% followed by 3·7-5·6-fold increases in caspase-3 activation for the aforementioned prodigiosin concentration ranges. Treatment with 100-400 nmol l^-1 prodigiosin increased the caspase-3/survivin, caspase-3/I-MMP-9 and caspase-3/S-MMP-9 ratios by 6-7·3-, 11·5-19·1- and 4·9-6·8-fold increases respectively. A dramatic increase in the number of apoptotic cells was also observed with increasing prodigiosin concentrations.

CONCLUSION

The inhibitory effects of prodigiosin on MMP-9 and survivin expression, as well as its pro-apoptotic capacity, represent a novel therapeutic avenue against ALL cells.

SIGNIFICANCE AND IMPACT OF THE STUDY

These findings provide an important and interesting basis to develop a new therapeutic compound with high potential against ALL cells.

T-cell regulation through a basic suppressive mechanism targeting low-density lipoprotein receptor-related protein 1

Cell adhesion is generally considered to depend on positive regulation through ligation of integrins and cytokine receptors. However, here we show that T-cell adhesion, and notably also T-cell receptor (TCR) -induced activation, are subject to constant suppression through shedding of low-density lipoprotein receptor-related protein 1 (LRP1). The broad-spectrum metalloprotease inhibitor GM6001 abrogated shedding, so inducing prominent cell surface expression of LRP1 while enhancing TCR-induced activation and adhesion to β₁ and β₂ integrin ligands, hence arresting the cells. Integrin ligands also inhibited shedding but the effect was less potent than that of GM6001. Unlike GM6001, integrin ligands also induced cell surface expression of full-length thrombospondin-1 (TSP170) and TSP130, which associated with LRP1, and TSP110, which did not associate with LRP1. Cell surface expression of LRP1 and TSP130 were induced exclusively in adhering cells, expression of TSP110 preferentially in non-adhering cells and expression of TSP170 correlated with T-cell motility. The pro-adhesive chemokine CXCL12 also inhibited LRP1 shedding and induced surface expression of TSP170 and TSP130 while inhibiting TSP110. Exogenous TSP-1 and ligation of CD28 inhibited shedding although less effectively than GM6001, and the inhibition through CD28 was independent of TSP-1. Small interfering RNA silencing experiments confirmed involvement of LRP1 and TSP-1 in integrin-dependent adhesion and TCR-induced activation. Hence, the poor LRP1 expression in T cells depends on shedding. Integrin ligands and CXCL12 antagonize shedding through a TSP-1-dependent pathway and ligation of CD28 antagonizes shedding independent of TSP-1. The disappearance of LRP1 from the cell surface may provide basic immunosuppression at the T-cell level.

Matrix Metalloproteinases and Leukocyte Activation

As their name implies, matrix metalloproteinases (MMPs) are thought to degrade extracellular matrix proteins, a function that is indeed performed by some members. However, regardless of their cell source, matrix degradation is not the only function of these enzymes. Rather, individual MMPs have been shown to regulate specific immune processes, such as leukocyte influx and migration, antimicrobial activity, macrophage activation, and restoration of barrier function, typically by processing a range of nonmatrix protein substrates. Indeed, MMP expression is low under steady-state conditions but is markedly induced during inflammatory processes including infection, wound healing, and cancer. Increasing research is showing that MMPs are not just a downstream consequence of a generalized inflammatory process, but rather are critical factors in the overall regulation of the pattern, type, and duration of immune responses. This chapter outlines the role of leukocytes in tissue remodeling and describes recent progress in our understanding of how MMPs alter leukocyte activity.

In Vitro Assessment of Human Natural Killer Cell Migration and Invasion

Cell invasion assays are important to obtain valuable functional data relating to tissue migration and invasion of effector lymphocytes. Boyden chamber invasion assays represent a reductionist system that allows for easy manipulation using various extracellular matrix (ECM) components addressing migratory functions or invasion into/through a three-dimensional matrix where migration and invasion inhibitors as well as stimulators can be added. Presented here is a description using the Transwell(®) system where invasion and migration can be studied. It constitutes an inner cell culture well with a (PET) polycarbonate filter with 3-8 μm pores that allow for cells to transverse to the bottom chamber where they can be recorded by various methods (Fig. 1). The polycarbonate filters may be coated with ECM proteins for migration and adhesive studies or covered with a thick layer that occludes the pores to address matrix degradation, i.e., invasion as described in this chapter.

The role of inflammation in leukaemia

Acute leukaemias are a group of malignancies characterised by the invasion of the bone marrow by immature haematopoietic precursors and differentiation arrest at various maturation steps. Multiplicity of intrinsic and extrinsic factors influences the transformation and progression of leukaemia. The intrinsic factors encompass genetic alterations of cellular pathways leading to the activation of, among others, inflammatory pathways (such as nuclear factor kappa B). The extrinsic components include, among others, the inflammatory pathways activated by the bone marrow microenvironment and include chemokines, cytokines and adhesion molecules. In this chapter, we review the role of inflammatory processes in the transformation, survival and proliferation of leukaemias, particularly the role of nuclear factor kappa B and its downstream signalling in leukaemias and the novel therapeutic strategies that exploit potentially unique properties of inflammatory signalling that offer interesting options for future therapeutic interventions.

Expression of matrix metalloproteinase 2 and 9 and tissue inhibitor of metalloproteinase 1 in nonrecurrent vs recurrent nasal polyps

BACKGROUND

Matrix metalloproteinases (MMPs) 2 and 9 are a group of Zn2+-dependent endopeptidases to remodel the extracellular matrix. The association of these 2 endopeptidases with the development of morphologic changes in nasal polyps was previously described.

OBJECTIVE

To determine whether MMP-2, MMP-9, and tissue inhibitor of MMP-1 (TIMP-1) play a role in the recurrence of nasal polyps.

METHODS

To compare MMP-2, MMP-9, and TIMP-1 expression in recurrent vs nonrecurrent polyps, nasal polyps (NPs) and recurrent nasal polyps (RNPs) were obtained from 15 NP patients with chronic rhinosinusitis (CRS) undergoing endoscopic sinus surgery (ESS) and 15 RNP patients with CRS undergoing revision ESS. Fifteen specimens of inferior turbinate mucosa from patients undergoing nasal septal surgery were used as control. Through real-time polymerase chain reaction and immunohistochemistry, MMP-2, MMP-9, and TIMP-1 expressions were measured among controls, NP patients, and RNP patients.

RESULTS

Expression of MMP-9 messenger RNA in the NP patients was significantly higher than in the controls. In addition, expression of MMP-9 messenger RNA in the RNP patents was significantly increased compared with NP patients. With immunohistochemistry, a more increased expression of MMP-9 was observed in NP patients than controls. Expression of MMP-9 in RNP patients was also significantly high compared with NP patients, particularly in stroma.

CONCLUSION

Expression of MMP-9 is increased in NP patients, and it is so more in the mucosa of RNP patients. Increased expression of MMP-9 is particularly found in the stoma of RNP patients, and it may contribute to the recurrence of NP.

T-cell production of matrix metalloproteinases and inhibition of parasite clearance by TIMP-1 during chronic Toxoplasma infection in the brain

Chronic infection with the intracellular protozoan parasite Toxoplasma gondii leads to tissue remodelling in the brain and a continuous requirement for peripheral leucocyte migration within the CNS (central nervous system). In the present study, we investigate the role of MMPs (matrix metalloproteinases) and their inhibitors in T-cell migration into the infected brain. Increased expression of two key molecules, MMP-8 and MMP-10, along with their inhibitor, TIMP-1 (tissue inhibitor of metalloproteinases-1), was observed in the CNS following infection. Analysis of infiltrating lymphocytes demonstrated MMP-8 and -10 production by CD4+ and CD8+ T-cells. In addition, infiltrating T-cells and CNS resident astrocytes increased their expression of TIMP-1 following infection. TIMP-1-deficient mice had a decrease in perivascular accumulation of lymphocyte populations, yet an increase in the proportion of CD4+ T-cells that had trafficked into the CNS. This was accompanied by a reduction in parasite burden in the brain. Taken together, these findings demonstrate a role for MMPs and TIMP-1 in the trafficking of lymphocytes into the CNS during chronic infection in the brain.

mRNA expression of matrix metalloproteinases (MMPs) 2 and 9 and tissue inhibitor of matrix metalloproteinases (TIMPs) 1 and 2 in childhood acute lymphoblastic leukemia: potential role of TIMP1 as an adverse prognostic factor

This study evaluates the mRNA expression profile of genes TIMP1, TIMP2, MMP2 and MMP9 in diagnostic bone marrow samples from 134 consecutive ALL children by real-time quantitative PCR. A significant association was observed between higher expression levels of MMP9 and low risk group and absence of extramedullary infiltration and higher expression levels of TIMP2 and MMP2 with T-ALL. TIMP1 gene expression values higher than the median were associated with a significantly lower 5-year event free-survival in univariable (P=0.04) and multivariable analysis (P=0.01). Our data address new information in the complex interaction of the migration/adhesion genes and childhood ALL.

Expression of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of matrix metalloproteinase (TIMP-1) in tissues with a diagnosis of childhood lymphoma

Matrix metalloproteinases (MMP) are enzymes involved in the reconfiguration of the microenvironment by means of degrading the extracellular matrix and have more than 20 subgroups containing zinc. Proteins that serve as the inhibitors of these enzymes are called tissue inhibitors of matrix metalloproteinase (TIMP). These enzymes have been shown to be active in a wide range of processes, from wound recovery to fetus development, heart diseases, and spread of malignant diseases. The aim of this study was to investigate whether there is a relationship between the type, stage, and prognosis of childhood lymphoma subjects and matrix metalloproteinase type-9 (MMP-9) and its inhibitor, tissue inhibitor of matrix metalloproteinase type-1 (TIMP-1). Paraffin blocks of childhood patients diagnosed with non-Hodgkin lymphoma (n = 23), Hodgkin lymphoma (n = 14), or reactive lymphadenopathy (n = 12) were retrospectively immunohistochemically stained with MMP-9 and TIMP-1 stains and whether there was a relationship between the degree of staining and the type, tumor stage, and prognosis of the disease was investigated. Moderate and high degrees of MMP-9 staining were detected in 94.6% of the lymphoma patient tissues and a slight TIMP-1 staining was detected in 21.6% of the lymphoma patient tissues. No relationship was observed between the degree of these staining patterns and the type, tumor stage, and prognosis of the disease. This study indicates that the equilibrium between MMP-9 and TIMP-1 is important in lymphomas in addition to all the physiological and pathologic events although MMP-9 and the TIMP-1 staining patterns are not related to the tumor stage, prognosis, and type of the disease. Larger series of patients are needed to determine the prognostic value of MMP-9 and TIMP-1 in childhood lymphoma.

Memory versus naive T-cell migration

Our established understanding of lymphocyte migration suggests that naive and memory T cells travel throughout the body via divergent pathways; naive T cells circulate between blood and lymph whereas memory T cells additionally migrate through non-lymphoid organs. Evidence is now gradually emerging which suggests such disparate pathways between naive and memory T cells may not strictly be true, and that naive T cells gain access to the non-lymphoid environment in numbers approaching that of memory T cells. We discuss here the evidence for naive T-cell traffic into the non-lymphoid environment, compare and contrast this movement with what is known of memory T cells, and finally discuss the functional importance of why naive T cells might access the parenchymal tissues.

Angiogenesis factor pattern differs in acute lymphoblastic leukemia and chronic lymphocytic leukemia

Angiogenesis is an important event in the survival and progression of solid tumors. The angiogenic status and the exact role of the angiogenic cytokines in lymphoid leukemia has not been fully elucidated. We have investigated the profile of the systemic components of angiogenic regulation in B-lineage acute lymphoblastic leukemia (B-ALL) and B-chronic lymphocytic leukemia (B-CLL), namely vascular endothelial growth factor (VEGF), tumor necrosis factor-alpha (TNF-alpha), endostatin and matrix metalloproteinase-9 (MMP-9) using enzyme-linked immunosorbent assay (ELISA). In B-ALL patients, sVEGF, and MMP-9 were significantly lower than control levels at diagnosis (p < 0.001) and increased to near control levels in remission (p>0.05). Both serum TNF-alpha and endostatin levels showed no significant difference at diagnosis (p>0.05) and in remission (p>0.05) compared to control levels. VEGF, TNF-alpha, MMP-9 and endostatin levels were not significantly correlated with peripheral white cell count or bone marrow blast cell count, but were positively correlated with platelet count. In B-CLL patients, serum VEGF, MMP-9 and TNF-alpha were significantly higher (p < 0.001 = 0.009, 0.007, respectively) and decreased to near control levels in remission (p>0.05 for all). Serum endostatin levels showed no significant difference at diagnosis and in remission compared to control levels (p>0.05). A significant positive correlation between VEGF, TNF-alpha, MMP-9 and peripheral white cell counts, bone marrow lymphocytic count and platelets count were found. In conclusion, our data suggest that the driving forces of angiogenic factors (VEGF, TNF-alpha and MMP-9) in adult B-ALL appears different from that in B-CLL patients.

Relationship between matrix metalloproteinases MMP-2, MMP-9, tissue inhibitor of matrix metalloproteinases-1 and IL-5, IL-8 in nasal polyps

BACKGROUND

Nasal polyps (NP), a subgroup of chronic rhinosinusitis, are characterized by interleukin 5 (IL-5) mediated infiltration of eosinophils in sinus mucosa, leading to pseudostratified ciliated columnar epithelium, thickening of the epithelial basement membrane and tissue edema. Matrix metalloproteinases (MMP) constitute a large group of Zn2+ dependent endopeptidases with the ability to degrade extracellular matrix and are possibly responsible for the development of tissue edema in chronic sinusitis.

OBJECTIVE

The aim of this study was to determine the expression of MMP-2, MMP-9 and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) mRNA and to locate the distribution of MMP-2, MMP-9 and TIMP-1 by immunohistochemistry in ethmoid sinus mucosa in NP. Furthermore the correlation between IL-5 or IL-8 and MMP-2, MMP-9 or TIMP-1 is examined.

METHODS

Nasal polyps of 33 patients and 18 specimens of inferior turbinate mucosa were examined by real time RT-PCR for MMP-2, MMP-9, TIMP-1, IL-5 and IL-8 mRNA expression. Immunohistochemical labeling for MMP-2, MMP-9 and TIMP-1 was performed.

RESULTS

Differences between both locations were detectable for MMP-9 (P < 0.001) and IL-5 (P=0.003) but not for MMP-2 (P=0.278), TIMP-1 (P=0.515) and IL-8 (P=0.386). Correlation was detected only between TIMP-1 and IL-5 (r=0.422, P =0.014). Cytoplasmic staining of MMP-2 was present in the apical part of the ciliated cells, submucosal glands and in smooth muscle cells. Matrix metalloproteinase-9 was expressed in surface epithelium, in seromucous glands and in polymorphonuclear cells.

CONCLUSIONS

Expression of MMP-9 and IL-5 mRNA are associated with NP. The correlation between IL-5 and TIMP-1 indicates the role of TIMP-1 in maintaining the homeostasis in NP.

IFN' synergizes with IL‐1α to up‐regulate MMP‐9 secretion in a cellular model of central nervous system tuberculosis

Matrix metalloproteinase-9 (MMP-9) activity is implicated in pathogenesis of central nervous system tuberculosis (CNS-TB). IFNgamma, a key cytokine in TB, usually inhibits MMP-9 secretion. Addition of IFNgamma to conditioned media from M. tb-infected monocytes (CoMTB) resulted in a 7-fold increase in MMP-9 activity detected by gelatin zymography (P<0.01). In contrast, tissue inhibitor of metalloproteinase (TIMP)-1 and -2 secretion, measured by ELISA, was suppressed. Dexamethasone abolished the synergistic increase in MMP-9 activity. Interleukin (IL)-1beta in CoMTB is a critical mediator of synergy with IFNgamma, and IL-1beta alone synergizes with IFNgamma to increase MMP-9 secretion from 51 +/- 31 to 762 +/- 136 U. IL-1beta activity is dependent on p38 mitogen-activated protein (MAPK) kinase, which was found to be phosphorylated in tissue specimens from patients with CNS-TB. Extracellular signal regulated kinase (Erk) and p38 MAPK activation did not affect IFNgamma signaling pathways. Inhibition of janus-activated kinase (JAK)-2 by 50 microM AG540 decreased MMP-9 secretion to 124 +/- 11.1 from 651 +/- 229 U of activity (P<0.01). However, signal transducer and activator of transcription (STAT)-3 but not STAT-1 phosphorylation was synergistically up-regulated by IFNgamma and CoMTB. In summary, synergy between IL-1beta and STAT-3 dependent IFNgamma signaling is key in control of up-regulation of MMP-9 activity in CNS-TB and may be a significant mechanism of brain tissue destruction.

Endogenous thrombospondin-1 is a cell-surface ligand for regulation of integrin-dependent T-lymphocyte adhesion

Lymphocyte adhesion to cells and extracellular matrix (ECM) via integrins plays a pivotal role for the function of the immune system. We show here that endogenous thrombospondin-1 (TSP-1) is a cell-surface ligand for cis interaction of surface receptors in T lymphocytes controlled by integrins and the T-cell antigen receptor (TCR/CD3). Stimulation of CD3 triggers rapid surface expression of TSP-1 in quiescent T cells, whereas activated cells express TSP-1 constitutively. Endogenous TSP-1 is attached to lipoprotein receptor-related protein 1 (LRP1/CD91) and calreticulin (CRT) on the cell surface through its NH2-terminal domain. Adhesion via integrins to ICAM-1 or ECM components up-regulates TSP turnover dramatically from a low level in nonadherent cells, whereas CD3 stimulation inhibits TSP turnover through interference with CD91/CRT-mediated internalization. Integrin-associated protein (IAP/CD47) is essential for TSP turnover and adhesion through interaction with the C-terminal domain of TSP-1 in response to triggering signals delivered at the NH2-terminal. These results indicate that endogenous TSP-1 connects separate cell-surface receptors functionally and regulates T-cell adhesion.

Increased plasma levels of matrix metalloproteinase-9 are associated with the severity of chronic urticaria

BACKGROUND

Matrix metalloproteinase (MMP)-9 is produced by many inflammatory cells such as macrophages, neutrophils, mast cells, eosinophils and T lymphocytes. Activated T cells are capable, through cell-cell contact, of inducing MMP-9 expression in human mast cells.

OBJECTIVE

To investigate the activation status of peripheral CD4+ T cells and the level of MMP-9 in the plasma of patients with chronic urticaria (CU), and whether MMP-9 levels are in association with CU severity.

METHODS

Study subjects included 29 patients with CU and 30 healthy control subjects. At the time of assessment, patients were divided into subgroups according to urticarial severity. Plasma levels of total MMP-9 (free pro-MMP-9 and free MMP-9) were determined by ELISA. CD4+ lymphocytes were positively selected with magnetic microbeads. After 48 h of activation, CD4+ T cells were assayed for both nuclear factor-kappa B (NF-kappa B) expression and proliferation.

RESULTS

Plasma levels of MMP-9 were found to be significantly higher in 29 CU patients compared with 18 healthy controls (186 +/- 174 vs. 31 +/- 21 ng/mL, P<0.0001). We also found a significant correlation between MMP-9 levels and urticarial severity (r = 0.92, P<0.001). In addition, CD4+ T cells from CU patients expressed higher levels of NF-kappa B than CD4+ T cells from healthy controls (82 +/- 30 vs. 69 +/- 20 optical density, P = 0.007). Finally, as compared with seven healthy individuals, DNA synthesis in CD4+ T cells from seven CU patients was found to be significantly elevated (1000 +/- 240 vs. 751 +/- 166 counts per minute, P = 0.01).

CONCLUSION

Increased levels of MMP-9 are found in CU patients, and particularly among those with severe disease. We also demonstrated that CD4+ T cells from such patients are highly activated.

The role of chemokines and extracellular matrix components in the migration of T lymphocytes into three-dimensional substrata

The role of chemokines and their interactions with extracellular matrix components (ECM) or the capacity of T cells to migrate into and accumulate within three-dimensional (3D) collagen type 1 substrata was studied. We examined the influence of chemokines and fibronectin on the infiltration properties of non-infiltrative (do not migrate into 3D substrata) and spontaneously infiltrative (migrate into 3D substrata) T-cell lines. Infiltrative and non-infiltrative T-acute lymphocytic leukaemic cell lines exhibited no consistent differences with respect to the expression of various chemokine receptors or beta(1)-integrins. Chemokines presented inside the collagen increased the depth of migration of infiltrative T-cell lines, but did not render non-infiltrative T-cell lines infiltrative, although they augmented the attachment of non-infiltrative T-cell lines to the upper surface of the collagen. The presence of fibronectin inside the collagen did not render non-infiltrative T-cell lines infiltrative, but markedly augmented the migration of 'infiltrative' T-cell lines into collagen. Both infiltrative and non-infiltrative T-cell lines showed migratory responses to chemokines in Boyden assays (migration detected on 2D substrata). These results indicate that the process of T-cell infiltration/migration into 3D substrata depends on a tissue penetration mechanism distinguishable from migration on 2D substrata and that the basic capacity of T cells to infiltrate is independent of chemokines and ECM components applied as attractants.

Autocrine Regulation of T Cell Motility by Calreticulin-Thrombospondin-1 Interaction

The mechanisms regulating T lymphocyte migration within the extracellular matrix are not understood. We show in this study that the thrombospondin-1 binding site of calreticulin, spanning aa 19-32, is a major triggering factor for T cell motility and migration within a three-dimensional collagen type 1 matrix, and that exogenous motogenic factors such as chemokines can stimulate migration via a calreticulin-thrombospondin-1 pathway. Endogenous calreticulin binding to the N-terminal domain of endogenous thrombospondin-1 elicited a motogenic signal to the T cells through the C-terminal domain of thrombospondin-1 and its cell surface receptor integrin-associated protein (CD47). Our data further revealed that thrombospondin-1 was expressed on the cell surface with a high turnover, and that PI3K and the Janus family of tyrosine kinases were required for T cell motility mediated through calreticulin, thrombospondin-1, and CD47. These results unveil an autocrine mechanism of calreticulin-thrombospondin-1-CD47 interaction for the control of T cell motility and migration within three-dimensional extracellular matrix substrata.

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

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

Somatostatin is a specific inhibitor of SDF-1alpha-induced T cell infiltration

The chemokine stromal cell-derived factor 1alpha (SDF-1alpha) is a potent stimulator of T cell infiltration into three-dimensional type I collagen matrices as demonstrated using T cells freshly isolated from blood and an activated T cell clone. The neuropeptide somatostatin selectively inhibits SDF-1alpha induced T cell infiltration by the same T cells including CD4 as well as CD8 positive cells, while somatostatin does not inhibit 'spontaneous' T cell infiltration. A number of other neuropeptides and opioids do not inhibit SDF-1alpha-induced T cell infiltration, indicating that the inhibitory effect is somatostatin-specific. The neuropeptide antagonist cyclosomatostatin abrogated the inhibitory effect of somatostatin on T cell infiltration, indicating that the effect of somatostatin is mediated via specific somatostatin receptors. Somatostatin does not inhibit SDF-1alpha-induced T cell attachment to the collagen substrate, which indicates that this neuropeptide specifically inhibits the process of chemokine-induced T cell penetration and migration through the collagen.

Interferons inhibit tumor necrosis factor-alpha-mediated matrix metalloproteinase-9 activation via interferon regulatory factor-1 binding competition with NF-kappa B

Enhanced expression of matrix metalloproteinase-9 (MMP-9) correlates with invasion during tumor progression. Interferons (IFNs) inhibit MMP-9 activation in response to tumor necrosis factor-alpha (TNF-alpha), and the latter activates the MMP-9 gene through NF-kappaB. Understanding the molecular basis for MMP-9 inhibition may provide tools to control cell invasion. The data reported here show the critical role of interferon regulatory factor-1 (IRF1) in the inhibition of MMP-9. (i) IFN treatment suppresses TNF-alpha-induced MMP-9 reporter activity in STAT1(+/+) cells but not in STAT1(-/-) cells. (ii) IRF1 transfection blocks TNF-alpha-mediated MMP-9 activation. (iii) IFNs phosphorylate STAT1 and induce IRF1 but do not affect Ikappa-B degradation nor NF-kappaB nuclear translocation. (iv) Nuclear NF-kappaB (p50/p65) and IRF1, but not STAT1, bind to the MMP-9 promoter region containing an IFN-responsive-like element overlapping the NF-kappaB-binding site. (v) Recombinant IRF1, although unable to bind to an NF-kappaB consensus sequence, competes with NF-kappaB proteins for binding to the MMP-9 promoter. (vi) Conversely recombinant p50/p65 proteins reduce IRF1-DNA binding. (vii) In cells cotransfected with IRF1 and/or p65 expression vectors, an excess of IRF1 reduces MMP-9 reporter activity, whereas an excess of p65 blocks the inhibitory effect of IFN-gamma. Thus, in contrast to the known synergism between IRF1 and NF-kappaB, our data identify a novel role for IRF1 as a competitive inhibitor of NF-kappaB binding to the particular MMP-9 promoter context.

Matrix metalloproteinase-9 deficiency impairs cellular infiltration and bronchial hyperresponsiveness during allergen-induced airway inflammation

We investigated the specific role of matrix metalloproteinase (MMP)-9 in allergic asthma using a murine model of allergen-induced airway inflammation and airway hyperresponsiveness in MMP-9(-/-) mice and their corresponding wild-type (WT) littermates. After a single intraperitoneal sensitization to ovalbumin, the mice were exposed daily either to ovalbumin (1%) or phosphate-buffered saline aerosols from days 14 to 21. Significantly less peribronchial mononuclear cell infiltration of the airways and less lymphocytes in the bronchoalveolar lavage fluid were detected in challenged MMP-9(-/-) as compared to WT mice. In contrast, comparable numbers of bronchoalveolar lavage fluid eosinophils were observed in both genotypes. After allergen exposure, the WT mice developed a significant airway hyperresponsiveness to carbachol whereas the MMP-9(-/-) mice failed to do so. Allergen exposure induced an increase of MMP-9-related gelatinolytic activity in WT lung extracts. Quantitative reverse transcriptase-polymerase chain reaction showed increased mRNA levels of MMP-12, MMP-14, and urokinase-type plasminogen activator after allergen exposure in the lung extracts of WT mice but not in MMP-9-deficient mice. In contrast, the expression of tissue inhibitor of metalloproteinases-1 was enhanced after allergen exposure in both groups. We conclude that MMP-9 plays a key role in the development of airway inflammation after allergen exposure.

Production of matrix metalloproteinase-9 in early stage B-CLL: suppression by interferons

Besides vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF), matrix metalloproteinases (MMPs) play critical roles in angiogenesis, tumor invasion and metastasis. Increased angiogenesis is observed in chronic B lymphocytic leukemia (B-CLL) and published data reported VEGF and bFGF production in this disease. The purpose of this study was to investigate MMP expression in early stage B-CLL. Elevated MMP-9 concentrations were detected by ELISA in the sera of B-CLL patients (median level 250 ng/ml) compared with healthy donors (67 ng/ml) (P < 0.0001), and immunostaining with antibodies against MMP-9 and B cell antigens (CD19, CD23) substantiated the presence of MMP-9 in tumoral B lymphocytes. By using RT-PCR, ELISA and zymography experiments, we confirmed that B-CLL cells expressed and released the pro-form of MMP-9 with Mr 92 kDa (158-1300 pg/ml/10(6) cells/48 h), p-aminophenylmercuric acetate generating a 82 kDa active form. In contrast, the production of MMP-9 by normal counterpart B cells was significantly low (28-169 pg/ml/10(6)cells/48 h). Moreover, B-CLL culture supernatants contained bFGF (median levels 17 pg/ml/10(6) cells/48 h), VEGF (1.4 pg/ml/10(6) cells/48 h) and TNF-alpha (0.2 pg/ml/10(6) cells/48 h). TNF-alpha and VEGF antibodies blocked MMP-9 at the mRNA and protein levels. Interferons (IFNs) type I or type II repressed MMP-9 gelatinolytic activity in a dose and time dependency, and this was reflected by a parallel inhibition of MMP-9 mRNA and protein. IFNs however did not affect the production of bFGF, VEGF and TNF-alpha. Together, our data show that B-CLL lymphocytes synthesize MMP-9 and emphasize the specific inhibitory actions of IFNs on its expression.

Matrix and serine protease expression during leukemic cell differentiation induced by aclacinomycin and all-trans-retinoic acid

In myeloid leukemia, immature leukemic cells are able to egress into peripheral blood to infiltrate extra-medullary organs. We therefore analyzed the migrating and invasive potential of human HL-60 and NB4 cell lines, representative of acute myelogenous leukemia, their ability to express matrix metalloproteases (MMPs), tissue inhibitors of metalloproteases (TIMPs) and urokinase plasminogen activator (uPA) in response to differentiating agents. Granulocytic differentiation by all-trans-retinoic acid (ATRA) and aclacinomycin (ACLA) strongly increased HL-60 and NB4 cell migration and invasion. At mRNA and protein levels, these cell lines produced significant amounts of MMP-9 (HL-60<NB4). Granulocytic differentiation by ACLA increased both pro and active forms of MMP-9 whereas ATRA decreased them and stimulated uPA mRNAs. TIMP-1, the physiological MMP inhibitor, increased during granulocytic differentiation whereas TIMP-2 did not significantly vary. Use of Batimastat and aprotinin suggests that ATRA was active by modulating the uPA system while ACLA interfered with MMP expression. In conclusion, our data demonstrate that HL-60 and NB4 cells express MMPs and uPA which are differentially regulated by the differentiating agents ATRA and ACLA and suggest the clinical usefulness of MMPs and serine protease inhibitors in the prophylaxis and treatment of the ATRA syndrome.

Expression and activity of matrix metalloproteases in human malignant mesothelioma cell lines

The extracellular matrix metalloproteases (MMPs) secreted by various human tumor cells play a crucial role in tumor cell invasion and metastasis, but their expression in malignant mesothelioma (MM) cells has not been examined. In this study, we have investigated the spectrum of MMPs and tissue inhibitors of metalloproteases (TIMPs) produced by 8 MM cell lines. Using RT-PCR, we found that all investigated MM cell lines expressed genes encoding mRNA for MMP-1 (interstitial collagenase), MMP-2 (gelatinase A), MMP-3 (stromelysin-1), MMP-9 (gelatinase B) and TIMPs 1, 2 and 3. We also found that 6/8 MM cell lines expressed MMP-7 (matrilysin) and 3/8 MM cell lines expressed MMP-10 (stromelysin-2). MMP-11 (stromelysin-3) was not detected in any of the MM cell lines. Production of MMP-2 and MMP-9 was confirmed using gelatin zymography. In addition, all MM cell lines secreted a 66 kDa metalloprotease, while 3/8 MM cell lines secreted 46, 48, 51 and 63 kDa metalloproteases which specifically degraded the extracellular matrix components fibronectin, vitronectin and laminin. The 66 kDa protease was identified as MMP-3 by Western blot. Our results reveal a broad spectrum of MMPs and TIMPs produced by MM cells and indicate that different substrate specificities of MMPs may play a role in MM cell invasion.