Retroviral vector-producer cell-mediated in vivo gene transfer of TIMP-3 restricts angiogenesis and neuroblastoma growth in mice

Stromal metalloproteinases: Crucial contributors to the tumor microenvironment

Proteolytic balance is crucial for the maintenance of tissue homeostasis. In cancer, dysregulated proteolysis is involved in unregulated tissue remodeling and inflammation, leading to the promotion of tumor growth, local invasion, and metastasis. Metalloproteinases, which were first identified as collagen cleaving enzymes, have been shown to extensively degrade extracellular matrix proteins or selectively release cell surface-bound cytokines, growth factors, or their receptors, thereby impacting extracellular matrix integrity, immune cell recruitment and tissue turnover. Although tumor cells produce various metalloproteinases, the major source is thought to be stromal cells infiltrating the tumor. Different types of stromal cells express specific sets of metalloproteinases and their inhibitors, which specifically alter the milieu within the tumor. In this review, recent findings and knowledge regarding metalloproteinases derived from stromal cells during the creation of the tumor microenvironment are described and their contribution to the tumor progression and metastasis discussed.

TIMPs: versatile extracellular regulators in cancer

A compelling long-term goal of cancer biology is to understand the crucial players during tumorigenesis in order to develop new interventions. Here, we review how the four non-redundant tissue inhibitors of metalloproteinases (TIMPs) regulate the pericellular proteolysis of a vast range of matrix and cell surface proteins, generating simultaneous effects on tumour architecture and cell signalling. Experimental studies demonstrate the contribution of TIMPs to the majority of cancer hallmarks, and human cancers invariably show TIMP deregulation in the tumour or stroma. Of the four TIMPs, TIMP1 overexpression or TIMP3 silencing is consistently associated with cancer progression or poor patient prognosis. Future efforts will align mouse model systems with changes in TIMPs in patients, will delineate protease-independent TIMP function, will pinpoint therapeutic targets within the TIMP-metalloproteinase-substrate network and will use TIMPs in liquid biopsy samples as biomarkers for cancer prognosis.

Effect of formaldehyde on miRNA-21 and its downstream proteins TIMP-3 and RECK in the liver

AIM: To investigate the effect of formaldehyde on miRNA-21 and its downstream proteins tissue inhibitor of metalloproteinase 3 (TIMP-3) and reversion-inducing cysteine-rich protein with Kazal motifs (RECK) in the liver of mice.

METHODS: Forty female Kunming mice were randomly divided into three formaldehyde groups (low-, medium- and high-concentration groups) and a control group. The three formaldehyde groups were intraperitoneally injected with different concentrations of formaldehyde at 10:00 am daily. The control group was injected with equal volume of normal saline. Real-time quantitative PCR (RT-PCR) was used to detect the changes of expression of miRNA-21 after 30 d. Immunohistochemistry and Western blot were used to test the expression of TIMP-3 and RECK in the liver.

RESULTS: The relative expression levels of miRNA-21 in the low-, medium-, and high-concentration groups, compared with that in the control group, were 1.16 ± 0.18, 1.61 ± 0.29 and 2.48 ± 0.49, respectively. There were significant differences in miRNA-21 expression among different groups (F = 38.02, P < 0.0001). The expression values of TIMP-3 in the control group, low-, medium-, and high-concentration groups were 1.30 ± 0.058, 1.04 ± 0.083, 0.85 ± 0.070 and 0.23 ± 0.067, respectively, and there were significant differences among different groups (F = 125.8, P < 0.0001). The expression values of RECK in the control group, low-, medium-, and high-concentration groups were 1.24 ± 0.057, 1.11 ± 0.056, 0.68 ± 0.042 and 0.35 ± 0.066, respectively, and there were also significant differences among different groups (F = 158.7, P < 0.0001). The relative expression of miRNA-21 showed a negative association with expression of TIMP-3 and RECK (r = -0.990, P = 0.01; r = -0.974, P = 0.026, respectively).

CONCLUSION: The expression of miRNA-21 in the liver is significantly increased by formaldehyde in a dose-dependent manner. Formaldehyde can decrease the expression of TIMP-3 and RECK in the same dose-dependent manner.

Relationship between morphological features and kinetic patterns of enhancement of the dynamic breast magnetic resonance imaging and tumor expression of metalloproteases and their inhibitors in invasive breast cancer

AIM

Matrix metalloproteases (MMPs) expression and their inhibitors (TIMPs) play an important role in tumor physiopathology, so we investigated the relationship between the magnetic resonance (MR) and MMPs/TIMPs expression by breast carcinomas.

MATERIALS AND METHODS

MRI parameters of 64 breast carcinomas were investigated. An immunohistochemical study was also performed in these cases using tissue microarrays and specific antibodies against MMP-1, MMP-2, MMP-7, MMP-9, MMP-11, MMP-13, MMP-14, TIMP-1, TIMP-2 and TIMP-3.

RESULTS

Tumors with spiculated margins had a high global (score) values of MMP-1 or MMP-7, and high expression of TIMP-3 by tumor cells. Heterogeneous tumors had a higher score values of MMP-1, MMP-13, TIMP-2 or TIMP-3, and frequent expression of TIMP-3 by tumor cells. Tumors showing fast enhancement, had higher score values of MMP-1 or MMP-11. Associations between washout curve (type III) and MMP-1, MMP-11, MMP-13 and TIMP-1 expression by tumor cells, were found.

CONCLUSIONS

MRI features may predict in some grade the expressions of MMPs/TIMPs in breast tumors, which might to contribute to a better biological characterization of breast cancer.

Anticancer gene transfer for cancer gene therapy

Gene therapy vectors are among the treatments currently used to treat malignant tumors. Gene therapy vectors use a specific therapeutic transgene that causes death in cancer cells. In early attempts at gene therapy, therapeutic transgenes were driven by non-specific vectors which induced toxicity to normal cells in addition to the cancer cells. Recently, novel cancer specific viral vectors have been developed that target cancer cells leaving normal cells unharmed. Here we review such cancer specific gene therapy systems currently used in the treatment of cancer and discuss the major challenges and future directions in this field.

High-throughput molecular and histopathologic profiling of tumor tissue in a novel transplantable model of murine neuroblastoma: new tools for pediatric drug discovery

Using two MYCN transgenic mouse strains, we established 10 transplantable neuroblastoma cell lines via serial orthotopic passage in the adrenal gland. Tissue arrays demonstrate that by histochemistry, vascularity, immunohistochemical staining for neuroblastoma markers, catecholamine analysis, and concurrent cDNA microarray analysis, there is a close correspondence between the transplantable lines and the spontaneous tumors. Several genes closely associated with the pathobiology and immune evasion of neuroblastoma, novel targets that warrant evaluation, and decreased expression of tumor suppressor genes are demonstrated. These studies describe a unique and generalizable approach to expand the utility of transgenic models of spontaneous tumor, providing new tools for preclinical investigation.

Targeting angiogenesis for controlling neuroblastoma

Neuroblastoma, a progressive solid tumor in childhood, continues to be a clinical challenge. It is highly vascular, heterogeneous, and extracranial tumor that originates from neural crest. Angiogenesis, genetic abnormalities, and oncogene amplification are mainly responsible for malignant phenotype of this tumor. Survivability of malignant neuroblastoma patients remains poor despite the use of traditional therapeutic strategies. Angiogenesis is a very common and necessary pre-requisite for tumor progression and metastasis. Angiogenesis is also a major factor in making malignant neuroblastoma. Thus, prevention of angiogenesis can be a highly significant strategy in the treatment of malignant neuroblastoma. Here, we summarize our current understanding of angiogenesis in malignant neuroblstoma and describe the use of experimental anti-angiogenic agents either alone or in combination therapy. This review will clearly indicate the importance of angiogenesis in the pathogenesis of malignant neuroblastoma, its prevention as a promising therapy in preclinical models of malignant neuroblastoma, and prospective clinical trials.

Functions of microRNA-21 in the liver

microRNAs (miRNAs) are a class of newly discovered small RNAs that can regulate every aspect of cellular activity, including differentiation, growth, metabolism, proliferation, apoptosis, viral infection, and tumorigenesis. Recent studies have provided clear evidence that miRNAs are abundant in the liver and participate in all physiological and pathological processes. microRNA-21 (miR-21) is one of the most studied miRNAs and has been demonstrated to be involved in tumorigenesis and some pathophysiological changes. However, there is little research on the roles of miR-21 in the liver. This paper will review the roles of miR-21 in liver regeneration, liver cell metabolism, immunity activity in liver, and the pathogenesis of human hepatocellular cancer and chronic hepatitis C.

"Buy one get one free": armed viruses for the treatment of cancer cells and their microenvironment

Oncolytic viral therapy is a promising biological therapy for the treatment of cancer. Recent advances in genetic engineering have facilitated the construction of custom-built oncolytic viruses that can be exquisitely targeted to tumors by exploiting each cancer's unique biology and their efficacy can be further enhanced by "arming" them with additional therapeutic genes. Such an approach allows the virus to unload its "therapeutic cargo" at the tumor site, thereby enhancing its anti-neoplastic properties. While several clever strategies have been recently described using genes that can induce cellular apoptosis/suicide and/or facilitate tumor/virus imaging, viruses armed with genes that also affect the tumor microenvironment present an exciting and promising approach to therapy. In this review we discuss recently developed oncolytic viruses armed with genes encoding for angiostatic factors, inflammatory cytokines, or proteases that modulate the extracellular matrix to regulate tumor vascularization, anti-tumor immune responses and viral spread throughout the solid tumor.

Inhibition of tumor growth and induction of apoptosis in prostate cancer cell lines by overexpression of tissue inhibitor of matrix metalloproteinase-3

The destruction of extracellular matrix by matrix metalloproteinases is a key event in cancer progression. The tissue inhibitors of metalloproteinases can restrain tumor growth by inhibiting these enzymes. We sought to determine whether overexpression of tissue inhibitor of metalloproteinase-3 (TIMP-3) could suppress the malignant phenotype of human prostate cancer cell line PC-3M. Stable overexpression of TIMP-3 inhibited cell proliferation significantly by MTT assay. Both early and late apoptosis were observed in TIMP-3 overexpressing cells, and flow cytometry analysis showed S-phase blocking of the cell cycle. Monolayer invasion assay and transwell invasion assay showed significantly decreased invasive potential in TIMP-3 overexpressing cells compared with control cells. Cell adhesion and motility were also lower after TIMP-3 was overexpressed. In vivo, cells stably overexpressing TIMP-3 completely lost the ability to form tumors after injection into nude mice. Transfection of TIMP-3 into established tumors by electroporation also had a significant antitumor effect. TIMP-3-treated tumor tissues had significant apoptosis by TUNEL assay. These results showed that overexpression of TIMP-3 inhibits invasion and proliferation of prostate cancer cells in vitro and inhibits tumor growth in vivo. The experiments suggest a potential use for TIMP-3 in the gene therapy of prostate cancer.

ADAM17 co-purifies with TIMP-3 and modulates endothelial invasion responses in three-dimensional collagen matrices

In this study, we investigated potential mechanisms through which the known anti-angiogenic factor, tissue inhibitor of metalloproteinase-3 (TIMP-3) blocks angiogenesis. As a strategy to identify TIMP-3 binding proteins, we used tandem affinity purification, employing recombinant adenoviruses constructed to deliver TIMP-3 fused to C-terminal S and His tags (TIMP-3-S-His) or TIMP-1-S-His control to endothelial cells prior to extraction. Western blotting of final eluates revealed robust binding of A Disintegrin and Metalloproteinase (ADAM) 17 and a slight association of ADAM15 to TIMP-3, but not TIMP-1 control. To confirm a functional requirement for ADAM15 and 17 in mediating angiogenic events, a model of endothelial cell invasion was utilized. Silencing of ADAM17, but not ADAM15, expression using small interfering RNA (siRNA) interfered with invasion, resulting in decreased density of invading cells and decreased invasion distance. Stable EC lines expressing short hairpin RNA directed to ADAM17 were similarly inhibited. To confirm these results, dominant negative mutants (DeltaMPs) of ADAM10, ADAM15 or ADAM17 were delivered using recombinant lentiviruses. Expression of ADAM17 DeltaMP, but not ADAM10 or ADAM15 DeltaMP, decreased invasion density and distance. Further, time-lapse analyses revealed ADAM17 DeltaMP cells exhibited far greater numbers of protruding sprouts compared to control, suggesting an inability of extended processes to retract properly. Immunofluorescence analyses revealed ADAM17 localized to bifurcations in invading sprouts. These data jointly indicate a role for ADAM17 in modulating endothelial sprouting events during angiogenesis.

[The role of matrix metalloproteinases and tissue inhibitors of metalloproteinases in invasion of tumours of neuroepithelial tissue]

Tumour invasion requires degradation of extracellular matrix components and migration of cells through degraded structures into surrounding tissues. Matrix metalloproteinases (MMP) constitute a family of zinc and calcium-dependent endopeptidases that play a key role in the breakdown of extracellular matrix, and in processing of cytokines, growth factors, chemokines and cell surface receptors. Their activity is regulated at the levels of transcription, activation and inhibition by tissue inhibitors of metalloproteinases (TIMP). Changes in expression of MMP and TIMP are implicated in tumour invasion, because they may contribute to both migration of tumour cells and angiogenesis. Alterations of MMP expression observed in brain tumours arouse interest in the development and evaluation of synthetic matrix metalloproteinase inhibitors as antitumour agents.

Introduction of G1 phase arrest in Human Hepatocellular carcinoma cells (HHCC) by APMCF1 gene transfection through the down-regulation of TIMP3 and up-regulation of the CDK inhibitors p21

We previously found that there was up-regulation of APMCF1 expression in apoptotic MCF-7 cells. Moreover, bioinformatics analysis has found that APMCF1 molecules had similar size and structure with molecules which belong to small G-protein superfamily. We presume that APMCF1 plays certain biological role in the regulation of cell proliferation and apoptosis. In this study, we first detected the expression pattern of APMCF1 in human hepatocellular carcinoma cell line and find no expression in Human Hepatocellular carcinoma cells (HHCC) and enhanced expression in HepG2 cells. Expression of liposome-mediated ectogenic APMCF1 induced inhibition of HHCC growth and cell cycle, and RNAi inhibited APMCF1 expression and promoted HepG2 cell growth. Results of cell cycle gene chips analysis showed up-regulation of p21 expression and down-regulation of TIMP3 in HHCC cells expressing ectogenic APMCF1, indicating that APMCF1 participates at least partially in cell cycle regulation through regulating genes such as p21 and TIMP3.

TIMP-2 promotes cell spreading and adhesion via upregulation of Rap1 signaling

We previously demonstrated that TIMP-2 treatment of human microvascular endothelial cells (hMVECs) activates Rap1 via the pathway of paxillin-Crk-C3G. Here, we show that TIMP-2 overexpression in hMVECs by adenoviral infection enhances Rap1 expression, leading to further increase in Rap1-GTP. TIMP-2 expression, previously reported to inhibit cell migration, also leads to cell spreading accompanied with increased cell adhesion. HMVECs stably expressing Rap1 display a similar phenotype as hMVECs-TIMP-2, whereas the expression of inactive Rap1 mutant, Rap1(38N), leads to elongated appearance with greatly reduced cell adhesion. Furthermore, the phenotype of hMVECs-Rap1(38N) was not reversed by TIMP-2 overexpression. TIMP-2 greatly promotes the association of Rap1 with actin. Therefore, these findings suggest that TIMP-2 mediated alteration in cell morphology requires Rap1, TIMP-2 may recruit Rap1 to sites of actin cytoskeleton remodeling necessary for cell spreading, and enhanced cell adhesion by TIMP-2 expression may hinder cell migration.

TIMP-3 deficiency in the host, but not in the tumor, enhances tumor growth and angiogenesis

Tumor cells, stromal cell compartment and the extracellular matrix (ECM) together generate a multifaceted tumor microenvironment. Matrix metalloproteinases and their tissue inhibitors (TIMPs) provide a means for tumor-stromal interaction during tumorigenesis. Among TIMPs, TIMP-3 is uniquely localized to the ECM and is frequently silenced in human cancers. Here, we asked whether the absence of TIMP-3 in the tumor cell or the host affects the process of tumorigenesis. Timp-3(-/-) ES-cell clones were generated and used to develop teratomas in nude mice. Timp-3(-/-) teratomas showed similar tumor take, growth, and angiogenesis compared to timp-3(+/+) teratomas. To study the effect of TIMP-3 ablation in the host stroma, we measured the growth kinetics of subcutaneous B16F10 melanomas in timp-3(-/-) and wild-type littermates. Tumors grew significantly faster in timp-3(-/-) than in wild-type mice and their CD31 content was significantly higher indicating increased angiogenesis. Augmented angiogenesis in timp-3(-/-) mice was directly tested using Matrigel plug and Gelfoam assays. In response to FGF-2, timp-3(-/-) endothelial cells invaded more efficiently, leading to enhanced formation of functional blood vessels. Thus, TIMP-3 deficiency in the host, but not in the tumor per se, leads to enhanced tumor growth and angiogenesis. TIMP-3 located within the tumor microenvironment inhibits tumorigenesis.

Recent advances in the basic science of chondrosarcoma

Chondrosarcoma are a heterogeneous group of tumors whose treatment is limited to surgical removal. Molecular genetic analysis of these tumors has revealed some of the abnormalities responsible for the traits of the malignant phenotype.

Tissue inhibitor of metalloproteinase-3 expression from an oncolytic adenovirus inhibits matrix metalloproteinase activity in vivo without affecting antitumor efficacy in malignant glioma

Oncolytic adenoviruses exhibiting tumor-selective replication are promising anticancer agents. Insertion and expression of a transgene encoding tissue inhibitor of metalloproteinase-3 (TIMP-3), which has been reported to inhibit angiogenesis and tumor cell infiltration and induce apoptosis, may improve the antitumor activity of these agents. To assess the effects of TIMP-3 gene transfer to glioma cells, a replication-defective adenovirus encoding TIMP-3 (Ad.TIMP-3) was employed. Ad.TIMP-3 infection of a panel of glioma cell cultures decreased the proliferative capacity of these cells and induced morphologic changes characteristic for apoptosis. Next, a conditionally replicating adenovirus encoding TIMP-3 was constructed by inserting the TIMP-3 expression cassette into the E3 region of the adenoviral backbone containing a 24-bp deletion in E1A. This novel oncolytic adenovirus, AdDelta24TIMP-3, showed enhanced oncolytic activity on a panel of primary cell cultures and two glioma cell lines compared with the control oncolytic virus AdDelta24Luc. In vivo inhibition of matrix metalloproteinase (MMP) activity by AdDelta24TIMP-3 was shown in s.c. glioma xenografts. The functional activity of TIMP-3 was imaged noninvasively using a near-IR fluorescent MMP-2-activated probe. Tumoral MMP-2 activity was significantly reduced by 58% in the AdDelta24TIMP-3-treated tumors 24 hours after infection. A study into the therapeutic effects of combined oncolytic and antiproteolytic therapy was done in both a s.c. and an intracranial model for malignant glioma. Treatment of s.c. (U-87MG) or intracranial (U-87deltaEGFR) tumors with AdDelta24TIMP-3 and AdDelta24Luc both significantly inhibited tumor growth and prolonged survival compared with PBS-treated controls. However, expression of TIMP-3 in the context of AdDelta24 did not significantly affect the antitumor efficacy of this oncolytic agent.

Membrane type-matrix metalloproteinases and tumor progression

Matrix metalloproteinases (MMPs) are a family of zinc endopeptidases that process growth factors, growth factor binding proteins, cell surface proteins, degrade extracellular matrix (ECM) components and thereby play a central role in tissue remodeling and tumor progression. Membrane-type matrix metalloproteinases (MT-MMPs) are a recently discovered subgroup of intrinsic plasma membrane proteins. Their functions have been extended from pericellular proteolysis and control of cell migration to cell signaling, control of cell proliferation and regulation of multiple stages of tumor progression including growth and angiogenesis. This review sheds light on the new functions of MT-MMPs and their inhibitors in tumor development and angiogenesis, and presents recent investigations that document their influence on various cell functions.

Tissue inhibitors of metalloproteinase 2 inhibits endothelial cell migration through increased expression of RECK

The antiangiogenic function of the tissue inhibitors of metalloproteinases (TIMPs) has been attributed to their matrix metalloproteinase inhibitory activity. Here we demonstrate that TIMP-1 but not Ala+TIMP-1 inhibits both basal and vascular endothelial growth factor (VEGF)-stimulated migration of human microvascular endothelial cells (hMVECs), suggesting that this effect is dependent on direct inhibition of matrix metalloproteinase (MMP) activity. In contrast, TIMP-2 and mutant Ala+TIMP-2, which is devoid of MMP inhibitory activity, block hMVEC migration in response to VEGF-A stimulation. TIMP-2 and Ala+TIMP-2 also suppress basal hMVEC migration via a time-dependent mechanism mediated by enhanced expression of RECK, a membrane-anchored MMP inhibitor, which, in turn, inhibits cell migration. TIMP-2 treatment of hMVECs increases the association of Crk with C3G, resulting in enhanced Rap1 activation. hMVECs stably expressing Rap1 have increased RECK expression and display reduced cell migration compared with those expressing inactive Rap1(38N). RECK-null murine embryo fibroblasts fail to demonstrate TIMP-2-mediated decrease in cell migration despite activation of Rap1. TIMP-2-induced RECK decreases cell-associated MMP activity. Anti-RECK antibody increases MMP activity and reverses the TIMP-2-mediated reduction in cell migration. The effects of TIMP-2 on RECK expression and cell migration were confirmed in A2058 melanoma cells. These results suggest that TIMP-2 can inhibit cell migration via several distinct mechanisms. First, TIMP-2 can inhibit cell migration after VEGF stimulation by direct inhibition of MMP activity induced in response to VEGF stimulation. Secondly, TIMP-2 can disrupt VEGF signaling required for initiation of hMVEC migration. Third, TIMP-2 can enhance expression of RECK via Rap1 signaling resulting in an indirect, time-dependent inhibition of endothelial cell migration.

Antitumor effects of human ribonuclease inhibitor gene transfected on B16 melanoma cells

Human ribonuclease inhibitor (RI) is a cytoplasmic acidic protein. The experiment demonstrated that it might effectively inhibit tumor-induced angiogenesis and inhibit tumor growth. Ribonuclease inhibitor is constructed almost entirely of leucine-rich repeats, which might be involved in unknown biological effects besides inhibiting RNase A and angiogenin activities. The exact molecular mechanism of antitumor on ribonuclease inhibitor remains unclear so far. In order to further understand the function of ribonuclease inhibitor and investigate the relationship with tumor growth, our study established a transfection of human ribonuclease inhibitor cDNA into the murine B16 cells by the retroviral packaging cell line PA317. The cell line transfected with a stably high expression of ribonuclease inhibitor was identified. We found that the transfected ribonuclease inhibitor could obviously inhibit cell proliferation, regulate cell cycle and induce cell apoptosis in vitro. Mice that were injected with the B16 cells transfected RI cDNA showed a significant inhibition of the tumor growth with lighter tumor weight, lower density of microvessels, longer latent periods, and survival time than those in the other two control groups. In conclusion, the results reveal the novel mechanism that antitumor effect of ribonuclease inhibitor is also associated with inducing apoptosis, regulating cell cycle and inhibiting proliferation besides antiangiogenesis. These results suggest that ribonuclease inhibitor might be a candidate of tumor suppressor gene in some tissues. RI could become a target gene for gene therapy. Our study may be of biological and clinical importance.