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

The perlecan-interacting growth factor progranulin regulates ubiquitination, sorting, and lysosomal degradation of sortilin

Despite extensive clinical and experimental studies over the past decades, the pathogenesis and progression to the castration-resistant stage of prostate cancer remains largely unknown. Progranulin, a secreted growth factor, strongly binds the heparin-sulfate proteoglycan perlecan, and counteracts its biological activity. We established that progranulin acts as an autocrine growth factor and promotes prostate cancer cell motility, invasion, and anchorage-independent growth. Progranulin was overexpressed in prostate cancer tissues vis-à-vis non-neoplastic tissues supporting the hypothesis that progranulin may play a key role in prostate cancer progression. However, progranulin's mode of action is not well understood and proteins regulating progranulin signaling have not been identified. Sortilin, a single-pass type I transmembrane protein of the Vps10 family, binds progranulin in neurons and targets progranulin for lysosomal degradation. Significantly, in DU145 and PC3 cells, we detected very low levels of sortilin associated with high levels of progranulin production and enhanced motility. Restoring sortilin expression decreased progranulin levels, inhibited motility and anchorage-independent growth and destabilized Akt. These results demonstrated a critical role for sortilin in regulating progranulin and suggest that sortilin loss may contribute to prostate cancer progression. Here, we provide the novel observation that progranulin downregulated sortilin protein levels independent of transcription. Progranulin induced sortilin ubiquitination, internalization via clathrin-dependent endocytosis and sorting into early endosomes for lysosomal degradation. Collectively, these results constitute a regulatory feed-back mechanism whereby sortilin downregulation ensures sustained progranulin-mediated oncogenesis.

Hsp90β promoted endothelial cell-dependent tumor angiogenesis in hepatocellular carcinoma

Background

Vascular endothelial growth factor receptors (VEGFRs) are the major receptors involved in endothelial cell-dependent tumor angiogenesis. There are studies account for the effects of Hsp90 on angiogenesis, but the role and mechanism of Hsp90β isoforms and NVP-BEP800, a specific inhibitor of Hsp90β, in tumor angiogenesis is rarely mentioned.

Methods

Immunohistochemistry and statistical analysis was used to evaluate the correlation between Hsp90β expression, CD31 endothelial cell-dependent vessel density, and VEGFRs expression in tissue samples of 96 HCCs. Kaplan-Meier survival analysis and COX proportional hazards analysis the relation of Hsp90β and prognosis. HUVEC cells were transfected with Hsp90β or treated with NVP-BEP800, and then cell proliferation, migration, invasion and tube formation were investigated. The VEGFR1 and VEGFR2 expression was determined by Western blot and immunofluorescence. The VEGFR1 and VEGFR2 promoter activities were detected by dual luciferase report system. In vivo, the angiogenesis promotion of Hsp90β and anti-angiogenesis efficacy of NVP-BEP800 was tested in HCC xenograft models. Histological analysis was performed on tumor samples to evaluate Hsp90β, VEGFRs expression and MVD.

Results

This study investigated the correlation between Hsp90β expression and CD31+ endothelial cell-dependent vessel density. Hsp90β promoted VEGFRs expression by increasing their promoter activities. The proliferation, migration, invasion, and tube formation activities of human endothelial cells significantly increased when Hsp90β was overexpressed. NVP-BEP800 down-regulated VEGFRs expression to significantly reduce tubular differentiation, as well as endothelial cell proliferation, migration, and invasion. Furthermore, NVP-BEP800 decreased VEGFR1 and VEGFR2 promoter activities. In vivo, Hsp90β promoted VEGFRs and CD31 expression in human hepatocellular carcinoma tumor xenografts and was associated with increased tumor microvessel density. After 18 days of treatment with 30 mg/kg/day NVP-BEP800, VEGFRs and CD31 expression significantly decreased.

Conclusion

Hsp90β induced endothelial cell-dependent tumor angiogenesis by activating VEGFRs transcription. NVP-BEP800 has potential as a therapeutic strategy for inhibiting tumor angiogenesis by decreasing endothelial cell progression and metastasis. It can help develop a therapeutic strategy for tumor treatment through the inhibition of endothelial cell progression and metastasis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-017-0640-9) contains supplementary material, which is available to authorized users.

Decorin-inducible Peg3 Evokes Beclin 1-mediated Autophagy and Thrombospondin 1-mediated Angiostasis

We previously discovered that systemic delivery of decorin for treatment of breast carcinoma xenografts induces paternally expressed gene 3 (Peg3), an imprinted gene encoding a zinc finger transcription factor postulated to function as a tumor suppressor. Here we found that de novo expression of Peg3 increased Beclin 1 promoter activity and protein expression. This process required the full-length Peg3 as truncated mutants lacking either the N-terminal SCAN domain or the zinc fingers failed to translocate to the nucleus and promote Beclin 1 transcription. Importantly, overexpression of Peg3 in endothelial cells stimulated autophagy and concurrently inhibited endothelial cell migration and evasion from a 3D matrix. Mechanistically, we found that Peg3 induced the secretion of the powerful angiostatic glycoprotein Thrombospondin 1 independently of Beclin 1 transcriptional induction. Thus, we provide a new mechanism whereby Peg3 can simultaneously evoke autophagy in endothelial cells and attenuate angiogenesis.

VE-cadherin cleavage by ovarian cancer microparticles induces β-catenin phosphorylation in endothelial cells

Microparticles (MPs) are increasingly recognized as important mediators of cell-cell communication in tumour growth and metastasis by facilitating angiogenesis-related processes. While the effects of the MPs on recipient cells are usually well described in the literature, the leading process remains unclear. Here we isolated MPs from ovarian cancer cells and investigated their effect on endothelial cells. First, we demonstrated that ovarian cancer MPs trigger β-catenin activation in endothelial cells, inducing the upregulation of Wnt/β-catenin target genes and an increase of angiogenic properties. We showed that this MPs mediated activation of β-catenin in ECs was Wnt/Frizzled independent; but dependent on VE-cadherin localization disruption, αVβ3 integrin activation and MMP activity. Finally, we revealed that Rac1 and AKT were responsible for β-catenin phosphorylation and translocation to the nucleus. Overall, our results indicate that MPs released from cancer cells could play a major role in neo-angiogenesis through activation of beta catenin pathway in endothelial cells.

Exosome-derived microRNAs in cancer metabolism: possible implications in cancer diagnostics and therapy

Malignant progression is greatly affected by dynamic cross-talk between stromal and cancer cells. Exosomes are secreted nanovesicles that have key roles in cell–cell communication by transferring nucleic acids and proteins to target cells and tissues. Recently, MicroRNAs (miRs) and their delivery in exosomes have been implicated in physiological and pathological processes. Tumor-delivered miRs, interacting with stromal cells in the tumor microenvironment, modulate tumor progression, angiogenesis, metastasis and immune escape. Altered cell metabolism is one of the hallmarks of cancer. A number of different types of tumor rely on mitochondrial metabolism by triggering adaptive mechanisms to optimize their oxidative phosphorylation in relation to their substrate supply and energy demands. Exogenous exosomes can induce metabolic reprogramming by restoring the respiration of cancer cells and supress tumor growth. The exosomal miRs involved in the modulation of cancer metabolism may be potentially utilized for better diagnostics and therapy.

Delivery of curcumin by directed self-assembled micelles enhances therapeutic treatment of non-small-cell lung cancer

BACKGROUND

It has been widely reported that curcumin (CUR) exhibits anticancer activity and triggers the apoptosis of human A549 non-small-cell lung cancer (NSCLC) cells. However, its application is limited owing to its poor solubility and bioavailability. Therefore, there is an urgent need to develop a new CUR formulation with higher water solubility and better biocompatibility for clinical application in the future.

MATERIALS AND METHODS

In this study, CUR-loaded methoxy polyethylene glycol-polylactide (CUR/mPEG-PLA) polymeric micelles were prepared by a thin-film hydration method. Their characteristics and antitumor effects were evaluated subsequently.

RESULTS

The average size of CUR/mPEG-PLA micelles was 34.9±2.1 nm with its polydispersity index (PDI) in the range of 0.067-0.168. The encapsulation efficiency and drug loading were 90.2%±0.78% and 9.1%±0.07%, respectively. CUR was constantly released from the CUR/mPEG-PLA micelles, and its cellular uptake in A549 cells was significantly increased. It was also found that CUR/mPEG-PLA micelles inhibited A549 cell proliferation, increased the cell cytotoxicity, induced G2/M stage arrest and promoted cell apoptosis. Moreover, the CUR/mPEG-PLA micelles suppressed the migration and invasion of A549 cells more obviously than free CUR. Additionally, CUR/mPEG-PLA micelles inhibited human umbilical vein endothelial cells migration, invasion and corresponding tube formation, implying the antiangiogenesis ability. Its enhanced antitumor mechanism may be related to the reduced expression of vascular endothelial growth factor, matrix metalloproteinase (MMP)-2, MMP-9 and Bcl-2 as well as the increased expression of Bax.

CONCLUSION

The mPEG-PLA copolymer micelles can serve as an efficient carrier for CUR. The CUR/mPEG-PLA micelles have promising clinical potential in treating NSCLC.

Tumor Associated Macrophages as Therapeutic Targets for Breast Cancer

Tumor-associated macrophages (TAMs) are the most abundant inflammatory infiltrates in the tumor stroma. TAMs promote tumor growth by suppressing immunocompetent cells, including neovascularization and supporting cancer stem cells. In the chapter, we discuss recent efforts in reprogramming or inhibiting tumor-protecting properties of TAMs, and developing potential strategies to increase the efficacy of breast cancer treatment.

Matrix Metalloproteases as Biomarkers of Disease

Matrix metalloprotease play a vital role in many cellular processes. Dysfunction in activity of these enzymes has been implicated in the pathogenesis of a number of diseases. Factors that affect the balanced interaction between MMPs and their inhibitors, such as genetic mutations of extracellular matrix components or dysregulation of MMP expression, can lead to various diseases. Due to their essential role in ECM remodeling, MMPs have become targets of interest as biomarkers for the diagnosis and prognosis of diseases associated with alterations of the ECM.

The nature and biology of basement membranes

Basement membranes are delicate, nanoscale and pliable sheets of extracellular matrices that often act as linings or partitions in organisms. Previously considered as passive scaffolds segregating polarized cells, such as epithelial or endothelial cells, from the underlying mesenchyme, basement membranes have now reached the center stage of biology. They play a multitude of roles from blood filtration to muscle homeostasis, from storing growth factors and cytokines to controlling angiogenesis and tumor growth, from maintaining skin integrity and neuromuscular structure to affecting adipogenesis and fibrosis. Here, we will address developmental, structural and biochemical aspects of basement membranes and discuss some of the pathogenetic mechanisms causing diseases linked to abnormal basement membranes.

Sanguinarine inhibits growth and invasion of gastric cancer cells via regulation of the DUSP4/ERK pathway

Sanguinarine, a bioactive benzophenanthridine alkaloid extracted from plants of the Papaveraceae family, has shown antitumour effects in multiple cancer cells. But the therapeutic effects and regulatory mechanisms of sanguinatine in gastric cancer (GC) remain elusive. This study was aimed to investigate the correlation of dual‐specificity phosphatase 4 (DUSP4) expression with clinicopathologic features and overall survival in patients with GC and explore the effects of sanguinarine on tumour growth and invasion in GC cells (SGC‐7901 and HGC‐27) and underlying molecular mechanisms. Immunohistochemical analysis showed that decreased DUSP4 expression was associated with the sex, tumour size, depth of invasion and distant metastasis in patients with GC. Functional experiments including CCK‐8, Transwell and flow cytometry analysis indicated that sanguinarine or DUSP4 overexpression inhibited GC cell viability and invasive potential, and induced cell apoptosis and cycle arrest in S phase, but DUSP4 knockdown attenuated the antitumour activity of sanguinarine. Further observation demonstrated that sanguinarine up‐regulated the expression of DUSP4 and Bcl‐2‐associated X protein (Bax), but down‐regulated phosphorylated extracellular signal‐regulated kinase (p‐ERK), proliferating cell nuclear antigen (PCNA), matrix metalloproteinase 2 (MMP‐2) and B‐cell lymphoma 2 (Bcl‐2) expression. Taken together, our findings indicate that sanguinarine inhibits growth and invasion of GC cells through regulation of the DUSP4/ERK pathway, suggesting that sanguinarine may have potential for use in GC treatment.

Esophageal squamous cell carcinoma invasion is inhibited by Activin A in ACVRIB-positive cells

Background

Esophageal squamous cell carcinoma (ESCC) is a global public health issue, as it is the eighth most common cancer worldwide. The mechanisms behind ESCC invasion and progression are still poorly understood, and warrant further investigation into these processes and their drivers. In recent years, the ligand Activin A has been implicated as a player in the progression of a number of cancers. The objective of this study was to investigate the role of Activin A signaling in ESCC.

Methods

To investigate the role Activin A plays in ESCC biology, tissue microarrays containing 200 cores from 120 ESCC patients were analyzed upon immunofluorescence staining. We utilized three-dimensional organotypic reconstruct cultures of dysplastic and esophageal squamous tumor cells lines, in the context of fibroblast-secreted Activin A, to identify the effects of Activin A on cell invasion and determine protein expression and localization in epithelial and stromal compartments by immunofluorescence. To identify the functional consequences of stromal-derived Activin A on angiogenesis, we performed endothelial tube formation assays.

Results

Analysis of ESCC patient samples indicated that patients with high stromal Activin A expression had low epithelial ACVRIB, the Activin type I receptor. We found that overexpression of stromal-derived Activin A inhibited invasion of esophageal dysplastic squamous cells, ECdnT, and TE-2 ESCC cells, both positive for ACVRIB. This inhibition was accompanied by a decrease in expression of the extracellular matrix (ECM) protein fibronectin and podoplanin, which is often expressed at the leading edge during invasion. Endothelial tube formation was disrupted in the presence of conditioned media from fibroblasts overexpressing Activin A. Interestingly, ACVRIB-negative TE-11 cells did not show the prior observed effects in the context of Activin A overexpression, indicating a dependence on the presence of ACVRIB.

Conclusions

We describe the first observation of an inhibitory role for Activin A in ESCC progression that is dependent on the expression of ACVRIB.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2920-y) contains supplementary material, which is available to authorized users.

Emodin inhibits migration and invasion of MHCC-97H human hepatocellular carcinoma cells

Emodin, an anthraquinone derivative from the root and rhizome of Rheum palmatum L., was found to have antitumor effects in different types of cancer by regulating multi-molecular targets. The aim of the present study was to explore the effect of emodin on the migration and invasion of MHCC-97H human hepatocellular carcinoma cells and the underlying molecular mechanisms. Firstly, it was demonstrated that emodin can inhibit cell proliferation and induce apoptosis of cells in a time- and dose-dependent manner, using a MTT assay and flow cytometry, respectively. However, when emodin concentration was <50 µmol/l, it had little effect on the inhibition of proliferation or the induction of apoptosis. Then, it was observed that emodin can significantly suppress cell migration and invasion with a treatment dose <50 µmol/l compared with the control (P<0.05), which was not attributed to a decrease in cell number. Further study demonstrated that emodin significantly suppressed the expression levels of matrix metalloproteinase (MMP)-2 and MMP-9 compared with the control, which may be mediated by the activation of the p38 mitogen-activated protein kinases (MAPK) signaling pathway and suppression of extracellular signal regulated kinase (ERK)/MAPK and phosphatidylinositol 3-kinase/Akt signaling pathways. Therefore, the present study, for the first time, used MHCC-97H cells, which have the high potential of malignant invasion, to demonstrate that emodin may inhibit cell migration and invasion.

Decorin interacting network: A comprehensive analysis of decorin-binding partners and their versatile functions

Decorin, a prototype small leucine-rich proteoglycan, regulates a vast array of cellular processes including collagen fibrillogenesis, wound repair, angiostasis, tumor growth, and autophagy. This functional versatility arises from a wide array of decorin/protein interactions also including interactions with its single glycosaminoglycan side chain. The decorin-binding partners encompass numerous categories ranging from extracellular matrix molecules to cell surface receptors to growth factors and enzymes. Despite the diversity of the decorin interacting network, two main roles emerge as prominent themes in decorin function: maintenance of cellular structure and outside-in signaling, culminating in anti-tumorigenic effects. Here we present contemporary knowledge regarding the decorin interacting network and discuss in detail the biological relevance of these pleiotropic interactions, some of which could be targeted by therapeutic interventions.

Antiangiogenic Effects of VH02, a Novel Urea Derivative: In Vitro and in Vivo Studies

Vascular endothelial growth factor receptor 2 (VEGFR2) is a vital target for therapeutic intervention in cancer. We have recently described a computer-based drug design for a small molecule VEGFR2 inhibitor named VH02 (1-((1-(1H-indazol-6-yl)-1H-1,2,3-triazol-4-yl)methyl)-3-(3-chloromethylphenyl)urea). This study aimed to further explore the anti-angiogenic activity of VH02 both in vitro and in vivo. The in vitro assays include cell viability, capillary-like tube formation, MMP activity, and western blot analyses of signaling through VEGFR2 while the in vivo anti-angiogenic response were performed to evaluate the effect on vascularization in Matrigel plug applied in C57BL/6L mice. VH02 reduced angiogenesis behavior of EA.hy926 including cell viability, migration, adhesion, capillary-like tube formation, and MMP-2 activity induced by VEGF. Furthermore, VH02 regulated angiogenesis by directly inhibiting VEGFR2 on Tyr1175 signaling pathway leading to the inhibition of Akt-mediated cell survival and migration. Disruption of phosphorylation at VEGFR2-Tyr1175 by VH02 abolished FAK-Tyr397 signaling but not phosphorylation of p38 MAPK. This suggests that blockade of FAK by VH02 apparently associated with reduction of endothelial cell motility. Actin cytoskeleton rearrangement was diminished by VH02 in human endothelial cells. The anti-angiogenic effect of VH02 was confirmed in the in vivo model, revealing the reduction of vascular density in Matrigel plug after VH02 treatment. Additionally, the pericyte-like cells surrounding blood vessels in the plugs were significantly reduced as well as vascular density and p-Akt intensity. Our findings indicate that VH02 successfully inhibits VEGF-induced angiogenesis both in vitro and in vivo models. The compound could be further developed as an antiangiogenesis agent for cancer therapy.

Experimental Dissection of Metalloproteinase Inhibition-Mediated and Toxic Effects of Phenanthroline on Zebrafish Development

Metalloproteinases are zinc-dependent endopeptidases that function as primary effectors of tissue remodeling, cell-signaling, and many other roles. Their regulation is ferociously complex, and is exquisitely sensitive to their molecular milieu, making in vivo studies challenging. Phenanthroline (PhN) is an inexpensive, broad-spectrum inhibitor of metalloproteinases that functions by chelating the catalytic zinc ion, however its use in vivo has been limited due to suspected off-target effects. PhN is very similar in structure to phenanthrene (PhE), a well-studied poly aromatic hydrocarbon (PAH) known to cause toxicity in aquatic animals by activating the aryl hydrocarbon receptor (AhR). We show that zebrafish are more sensitive to PhN than PhE, and that PhN causes a superset of the effects caused by PhE. Morpholino knock-down of the AhR rescues the effects of PhN that are shared with PhE, suggesting these are due to PAH toxicity. The effects of PhN that are not shared with PhE (specifically disruption of neural crest development and angiogenesis) involve processes known to depend on metalloproteinase activity. Furthermore these PhN-specific effects are not rescued by AhR knock-down, suggesting that these are bona fide effects of metalloproteinase inhibition, and that PhN can be used as a broad spectrum metalloproteinase inhibitor for studies with zebrafish in vivo.

A current view of perlecan in physiology and pathology: A mosaic of functions

Perlecan, a large basement membrane heparan sulfate proteoglycan, is expressed in a wide array of tissues where it regulates diverse cellular processes including bone formation, inflammation, cardiac development, and angiogenesis. Here we provide a contemporary review germane to the biology of perlecan encompassing its genetic regulation as well as an analysis of its modular protein structure as it pertains to function. As perlecan signaling from the extracellular matrix converges on master regulators of autophagy, including AMPK and mTOR, via a specific interaction with vascular endothelial growth factor receptor 2, we specifically focus on the mechanism of action of perlecan in autophagy and angiogenesis and contrast the role of endorepellin, the C-terminal fragment of perlecan, in these cellular and morphogenic events.

Cyr61 participates in the pathogenesis of rheumatoid arthritis via promoting MMP-3 expression by fibroblast-like synoviocytes

OBJECTIVES

The aim of this study was to investigate the effect and potential mechanism of Cysteine-rich 61 (Cyr61) on stimulating MMP-3 expression by fibroblast-like synoviocytes (FLS) from rheumatoid arthritis (RA) patients.

METHODS

Primarily cultured RA FLS were treated with exogenous Cyr61 protein or Cyr61-siRNA, then, MMP-3 expression was analyzed by real-time PCR, western blotting and ELISA. Signal transduction pathways in Cyr61-induced MMP-3 production were examined by real-time PCR, western blotting, confocal microscopy, luciferase reporter assay. Mice with collagen-induced arthritis (CIA) were treated with anti-Cyr61 monoclonal antibodies (mAb), or IgG1 as control and MMP-3 in the joint was detected by IHC, real-time PCR and western blotting.

RESULTS

High expressed MMP-3 and Cyr61 were positively correlated in RA ST; Cyr61 stimulated MMP-3 production in FLS of RA patients in an IL-1β and TNF-α independent manner. Cyr61 induced MMP-3 could further enhance the invasive ability of RA FLS. Mechanistically, we found that Cyr61 promoted MMP-3 production via the P38, JNK-dependent AP-1 signaling pathway. Blockage of Cyr61 function with monoclonal antibody could decrease MMP-3 expression in the joints of CIA mice.

CONCLUSION

This study provides new evidence that Cyr61 participates in RA pathogenesis not only as a pro-inflammatory factor but also plays a key role in bone erosion via promoting MMP-3 expression. We suggest that targeting of Cyr61 may represent a potential strategy in RA treatment.

Expression of MMP and TIMP mRNA in Peripheral Blood Leukocytes of Patients with Invasive Ductal Carcinoma of the Breast

Purpose

An imbalance between matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) appears critical for tumor progression and metastasis. This study aimed to determine whether gene expression of MMP1, MMP2, MMP9, TIMP1 and TIMP3 and the MMP/TIMP expression ratio in peripheral blood leukocytes (PBLs) and the MMP1 and TIMP1 contents or MMP1/TIMP1 ratio in plasma were associated with clinicopathological characteristics in invasive ductal carcinoma (IDC) of the breast.

Materials and methods

Blood samples were collected from women newly diagnosed with IDC who had not received prior treatment (n = 102). Gene expression in PBLs was analyzed by quantitative real-time polymerase chain reaction. Concentrations of MMP1 and TIMP1 in plasma were measured using ELISA.

Results

In univariate analysis the expression levels of MMP2 and TIMP1 mRNA were significantly higher in premenopausal compared to postmenopausal patients (p<0.001 and p = 0.014, respectively). MMP2 mRNA expression negatively correlated with age (p<0.001, r = -0.43). We found that the MMP2/TIMP3 expression ratio was significantly higher in women after menopause (p = 0.007). The MMP2/TIMP1 expression ratio was higher in human epidermal growth factor receptor 2 (HER2)-positive patients (p = 0.022). Low-grade tumors had significantly lower MMP1/TIMP1 and MMP2/TIMP1 expression ratios (p = 0.047 and p = 0.048, respectively). TIMP1 plasma concentration was significantly higher in small tumors compared with T2-T3 tumors (p = 0.013).

Conclusions

These findings reveal an important association between tumor characteristics and expression ratios of MMP1/TIMP1 and MMP2/TIMP1 in PBLs and TIMP1 concentration in plasma. Menopausal status may influence the mRNA expression levels of MMP2 and TIMP1 as well as the MMP2/TIMP3 expression ratio in IDC of the breast.

Endorepellin-evoked Autophagy Contributes to Angiostasis

Endorepellin, the C-terminal domain of perlecan, is an angiostatic molecule that acts as a potent inducer of autophagy via its interaction with VEGFR2. In this study, we examined the effect of endorepellin on endothelial cells using atomic force microscopy. Soluble endorepellin caused morphological and biophysical changes such as an increase in cell surface roughness and cell height. Surprisingly, these changes were not accompanied by alterations in the endothelial cell elastic modulus. We discovered that endorepellin-induced autophagic flux led to co-localization of mammalian target of rapamycin with LC3-positive autophagosomes. Endorepellin functioned upstream of AMP-activated kinase α, as compound C, an inhibitor of AMP-activated kinase α, abrogated endorepellin-mediated activation and co-localization of Beclin 1 and LC3, thereby reducing autophagic progression. Functionally, we discovered that both endorepellin and Torin 1, a canonical autophagic inducer, blunted ex vivo angiogenesis. We conclude that autophagy is a novel mechanism by which endorepellin promotes angiostasis independent of nutrient deprivation.

Mutually Supportive Mechanisms of Inflammation and Vascular Remodeling

Chronic inflammation is often accompanied by angiogenesis, the development of new blood vessels from existing ones. This vascular response is a response to chronic hypoxia and/or ischemia, but is also contributory to the progression of disorders including atherosclerosis, arthritis, and tumor growth. Proinflammatory and proangiogenic mediators and signaling pathways form a complex and interrelated network in these conditions, and many factors exert multiple effects. Inflammation drives angiogenesis by direct and indirect mechanisms, promoting endothelial proliferation, migration, and vessel sprouting, but also by mediating extracellular matrix remodeling and release of sequestered growth factors, and recruitment of proangiogenic leukocyte subsets. The role of inflammation in promoting angiogenesis is well documented, but by facilitating greater infiltration of leukocytes and plasma proteins into inflamed tissues, angiogenesis can also propagate chronic inflammation. This review examines the mutually supportive relationship between angiogenesis and inflammation, and considers how these interactions might be exploited to promote resolution of chronic inflammatory or angiogenic disorders.

Blueberry inhibits invasion and angiogenesis in 7,12-dimethylbenz[a]anthracene (DMBA)-induced oral squamous cell carcinogenesis in hamsters via suppression of TGF-β and NF-κB signaling pathways

Aberrant activation of oncogenic signaling pathways plays a pivotal role in tumor initiation and progression. The purpose of the present study was to investigate the chemopreventive and therapeutic efficacy of blueberry in the hamster buccal pouch (HBP) carcinogenesis model based on its ability to target TGF-β, PI3K/Akt, MAPK and NF-κB signaling and its impact on invasion and angiogenesis. Squamous cell carcinomas were induced in the HBP by 7,12-dimethylbenz[a]anthracene (DMBA). The effect of blueberry on the oncogenic signaling pathways and downstream events was analyzed by quantitative real-time PCR and immunoblotting. Experiments with the ECV304 cell line were performed to explore the mechanism by which blueberry regulates angiogenesis. Blueberry supplementation inhibited the development and progression of HBP carcinomas by abrogating TGF-β and PI3K/Akt pathways. Although blueberry failed to influence MAPK, it suppressed NF-κB activation by preventing nuclear translocation of NF-κB p65. Blueberry also modulated the expression of the oncomiR miR-21 and the tumor suppressor let-7. Collectively, these changes induced a shift to an anti-invasive and anti-angiogenic phenotype as evidenced by downregulating matrix metalloproteinases and vascular endothelial growth factor. Blueberry also inhibited angiogenesis in ECV304 cells by suppressing migration and tube formation. The results of the present study suggest that targeting oncogenic signaling pathways that influence acquisition of cancer hallmarks is an effective strategy for chemointervention. Identification of modulatory effects on phosphorylation, intracellular localization of oncogenic transcription factors and microRNAs unraveled by the present study as key mechanisms of action of blueberry is critical from a therapeutic perspective.

Licoricidin, an Active Compound in the Hexane/Ethanol Extract of Glycyrrhiza uralensis, Inhibits Lung Metastasis of 4T1 Murine Mammary Carcinoma Cells

Licorice extracts containing glycyrrhizin exhibit anti-carcinogenic properties. Because glycyrrhizin induces severe hypokalemia and hypertension, we prepared a hexane/ethanol extract of Glycyrrhizauralensis (HEGU) that lacks glycyrrhizin, and showed that HEGU induces apoptosis and G1 cell cycle arrest and inhibits migration of DU145 human prostate cancer cells. Our previous in vitro studies identified two active components in HEGU: isoangustone A, which induces apoptosis and G1 cycle arrest, and licoricidin, which inhibits metastasis. This study examined whether HEGU and licoricidin inhibit metastasis using the 4T1 mammary cancer model. Both HEGU and licoricidin treatment reduced pulmonary metastasis and the expression of CD45, CD31, HIF-1α, iNOS, COX-2, and VEGF-A in tumor tissues. Additionally, a decrease in protein expression of VEGF-R2, VEGF-C, VEGF-R3, and LYVE-1 was noted in tumor tissues of licoricidin-treated mice. Furthermore, the blood concentrations of MMP-9, ICAM-1, VCAM-1, and VEGF-A were decreased in HEGU-treated mice. In vitro 4T1 cell culture results showed that both HEGU and licoricidin inhibited cell migration, MMP-9 secretion, and VCAM expression. The present study demonstrates that the licoricidin in HEGU inhibits lung metastasis of 4T1 mammary carcinoma cells, which may be mediated via inhibition of cancer cell migration, tumor angiogenesis, and lymphangiogenesis.

Matrix metalloproteinase-9 and -2 and tissue inhibitor of matrix metalloproteinase-2 in invasive pituitary adenomas: A systematic review and meta-analysis of case-control trials

The extracellular matrix is important for tumor invasion and metastasis. Normal function of the extracellular matrix depends on the balance between matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). The objective of this meta-analysis was to assess the relationship between expression of MMP-9, MMP-2, and TIMP-2 and invasion of pituitary adenomas.We searched Pubmed, Embase, and the Chinese Biomedical Database up to October 2015. RevMan 5.1 software (Cochrane Collaboration, Copenhagen, Denmark) was used for statistical analysis. We calculated the standardized mean difference (SMD) for data expressed as mean ± standard deviation because of the difference in the detection method.Twenty-four studies (1320 patients) were included. MMP-9 expression was higher in the patients with invasive pituitary adenomas (IPAs) than patients with noninvasive pituitary adenomas (NIPAs) with detection methods of IHC [odds ratio (OR) = 5.48, 95% confidence interval (CI) = 2.61-11.50, P < 0.00001), and reverse transcriptase-polymerase chain reaction (SMD = 2.28, 95% CI = 0.91-3.64, P = 0.001). MMP-2 expression was also increased in patients with IPAs at the protein level (OR = 3.58, 95% CI = 1.63-7.87, P = 0.001), and RNA level (SMD = 3.91, 95% CI = 1.52-6.29, P = 0.001). Meta-analysis showed that there was no difference in TIMP-2 expression between invasive and NIPAs at the protein level (OR = 0.38, 95% CI = 0.06-2.26, P = 0.29). MMP-9 expression in prolactinomas and nonfunctioning pituitary adenomas was also no difference (OR = 1.03, 95% CI = 0.48-2.20, P = 0.95).The results indicated that MMP-9 and -2 may be correlated with invasiveness of pituitary adenomas, although their relationship with functional status of pituitary adenomas is still not clear. TIMP-2 expression in IPAs needs to be investigated further.

Leptin promotes proliferation and metastasis of human gallbladder cancer through OB-Rb leptin receptor

Emerging evidence has shown that leptin, an adipocyte-derived cytokine that is closely associated with obesity, play a significant role in carcinogenesis and tumorigenesis. However, its impact on gallbladder cancer (GBC) remains unclear. In this study, we firstly found that leptin and its functional receptor OB-Rb were significantly co-expressed in human GBC tissues and cell lines, the content of which were higher than those in normal human gallbladder tissues. Treatment with leptin promoted the proliferation, migration and invasion of GBC cells, which were attenuated by OB-Rb shRNA. Blocking in the G2/M period of cell cycle, increasing of MMP3 and MMP9, increasing of VEGF-C/D, activation of SOCS3/JAK2/p-STAT3 pathway was demonstrated after treatment with leptin. All of these positive responses were attenuated by OB-Rb receptor shRNA. Taken together, our findings suggest that leptin promoted the proliferation, migration and invasion of GBC cells by increasing OB-Rb expression through the SOCS3/JAK2/p-STAT3 signal pathway. Targeting the leptin/OB-Rb axis could be an attractive therapeutic strategy for treatment of GBC.

The Contribution of Angiogenesis to the Process of Metastasis

The role of angiogenesis in tumor growth has been studied continuously for over 45 years. It is now appreciated that angiogenesis is also essential for the dissemination and establishment of tumor metastases. In this review, we focus on the role of angiogenesis as a necessity for the escape of tumor cells into the bloodstream and for the establishment of metastatic colonies in secondary sites. We also discuss the role of tumor lymphangiogenesis as a means of dissemination of lymphatic metastases. Appropriate combination therapies may be used in the future to both prevent and treat metastatic disease through the rational use of antiangiogenic and antilymphangiogenic therapies in ways that are informed by the current and future work in the field.

Evaluation of Antiangiogenic Efficacy of Emilia sonchifolia (L.) DC on Tumor-Specific Neovessel Formation by Regulating MMPs, VEGF, and Proinflammatory Cytokines

Formation of new blood vessels from preexisting vasculature is an indispensable process in tumor initiation, invasion, and metastasis. Novel therapeutic approaches target endothelial cells involved in the process of angiogenesis, due to their genetic stability relative to the rapidly mutating drug-resistant cancer cells. In the present study, we investigated the effect of an active fraction from Emilia sonchifolia, belonging to the family Asteraceae, a plant well known for its anti-inflammatory and antitumor effects, on the inhibition of tumor-specific angiogenesis. Administration of the active fraction from E sonchifolia (AFES; 5 mg/kg, body weight, intraperitoneally) containing the major compound γ-humulene significantly inhibited B16F10 melanoma-induced capillary formation in C57BL/6 mice. The level of serum vascular endothelial growth factor and serum proinflammatory cytokines such as interleukin-1β, interleukin-6, tumor necrosis factor-α, and granulocyte-macrophage colony-stimulating factor were also reduced significantly. At the same time, administration of AFES significantly enhanced the production of antiangiogenic factors such as tissue inhibitor of matrix metalloproteinase-1. Dose-dependent reduction can be seen in the budding and expansion of microvessels from rat thoracic aorta by AFES treatment. Inhibition of the activation of proenzyme to active enzyme of matrix metalloproteinase along with a successful reduction of proliferation, invasion, and migration of human umbilical vein endothelial cells demonstrated the antiangiogenic effect of AFES in vitro. To date, no study has examined the antiangiogenic activity of this plant with already well-known anti-inflammatory and antitumor effects. Results obtained in the present study by using both in vivo and in vitro angiogenic models altogether proved the inhibitory effect of AFES on tumor-specific neovessel formation.

Skeletal biology: Where matrix meets mineral

The skeleton is unique from all other tissues in the body because of its ability to mineralize. The incorporation of mineral into bones and teeth is essential to give them strength and structure for body support and function. For years, researchers have wondered how mineralized tissues form and repair. A major focus in this context has been on the role of the extracellular matrix, which harbors key regulators of the mineralization process. In this introductory minireview, we will review some key concepts of matrix biology as it related to mineralized tissues. Concurrently, we will highlight the subject of this special issue covering many aspects of mineralized tissues, including bones and teeth and their associated structures cartilage and tendon. Areas of emphasis are on the generation and analysis of new animal models with permutations of matrix components as well as the development of new approaches for tissue engineering for repair of damaged hard tissue. In assembling key topics on mineralized tissues written by leaders in our field, we hope the reader will get a broad view of the topic and all of its fascinating complexities.

Tumor cell intravasation

The process of entering the bloodstream, intravasation, is a necessary step in the development of distant metastases. The focus of this review is on the pathways and molecules that have been identified as being important based on current in vitro and in vivo assays for intravasation. Properties of the vasculature which are important for intravasation include microvessel density and also diameter of the vasculature, with increased intravasation correlating with increased vessel diameter in some tumors. TGFB signaling can enhance intravasation at least in part through induction of EMT, and we discuss other TGFB target genes that are important for intravasation. In addition to TGFB signaling, a number of studies have demonstrated that activation of EGF receptor family members stimulates intravasation, with downstream signaling through PI3K, N-WASP, RhoA, and WASP to induce invadopodia. With respect to proteases, there is strong evidence for contributions by uPA/uPAR, while the roles of MMPs in intravasation may be more tumor specific. Other cells including macrophages, fibroblasts, neutrophils, and platelets can also play a role in enhancing tumor cell intravasation. The technology is now available to interrogate the expression patterns of circulating tumor cells, which will provide an important reality check for the model systems being used. With a better understanding of the mechanisms underlying intravasation, the goal is to provide new opportunities for improving prognosis as well as potentially developing new treatments.

MMP-13 is constitutively produced in human chondrocytes and co-endocytosed with ADAMTS-5 and TIMP-3 by the endocytic receptor LRP1

Matrix metalloproteinase 13 (MMP-13) degrades collagenous extracellular matrix and its aberrant activity associates with diseases such as arthritis, cancer, atherosclerosis and fibrosis. The wide range of MMP-13 proteolytic capacity suggests that it is a powerful, potentially destructive proteinase and thus it has been believed that MMP-13 is not produced in most adult human tissues in the steady state. Present study has revealed that human chondrocytes isolated from healthy adults constitutively express and secrete MMP-13, but that it is rapidly endocytosed and degraded by chondrocytes. Both pro- and activated MMP-13 bind to clusters II and III of low-density lipoprotein (LDL) receptor-related protein 1 (LRP1). Domain deletion studies indicated that the hemopexin domain is responsible for this interaction. Binding competition between MMP-13 and ADAMTS-4, -5 or TIMP-3, which also bind to cluster II, further shown that the MMP-13 binding site within cluster II is different from those of ADAMTS-4, -5 or TIMP-3. MMP-13 is therefore co-endocytosed with ADAMTS-5 and TIMP-3 by human chondrocytes. These findings indicate that MMP-13 may play a role on physiological turnover of cartilage extracellular matrix and that LRP1 is a key modulator of extracellular levels of MMP-13 and its internalization is independent of the levels of ADAMTS-4, -5 and TIMP-3.

•

ProMMP-13 is constitutively produced and endocytosed by chondrocytes.

•

LRP1 is a key modulator of extracellular levels of proMMP-13 and MMP-13.

•

ProMMP-13 and MMP-13 directly bind to LRP1 via the hemopexin domain.

•

Unique sites on LRP1 for MMP-13 binding have been mapped.

•

Co-endocytosis of proMMP-13 with ADAMTS-4, -5 and TIMP-3.

Kaempferol inhibits the growth and metastasis of cholangiocarcinoma in vitro and in vivo

Kaempferol is a flavonoid that has been reported to exhibit antitumor activity in various malignant tumors. However, the role of kaempferol on cholangiocarcinoma (CCA) is largely unknown. In this article, we found that kaempferol inhibited proliferation, reduced colony formation ability, and induced apoptosis in HCCC9810 and QBC939 cells in vitro. Results from transwell assay and wound-healing assay demonstrated that kaempferol significantly suppressed the migration and invasion abilities of HCCC9810 and QBC939 cells in vitro. Kaempferol was found to decrease the expression of Bcl-2 and increase the expressions of Bax, Fas, cleaved-caspase 3, cleaved-caspase 8, cleaved-caspase 9, and cleaved-PARP. In addition, kaempferol also downregulated the levels of phosphorylated AKT, TIMP2, and MMP2. In vivo, it was found that the volume of subcutaneous xenograft (0.15 cm(3)) in the kaempferol-treated group was smaller than that (0.6 cm(3)) in the control group. Kaempferol also suppressed the number and volume of metastasis foci in the lung metastasis model, with no marked effects on body weight of mice. Immunohistochemistry assay showed that the number of Ki-67-positive cells was lower in the kaempferol-treated group than that in the control group. We further confirmed that the changes of apoptosis- and invasion-related proteins after kaempferol treatment in vivo were similar to the results in vitro. These data suggest that kaempferol may be a promising candidate agent for the treatment of CCA.

Effects of survivin on angiogenesis in vivo and in vitro

OBJECTIVE

In this study, the effects of survivin (SVV) on angiogenesis were evaluated in vitro and in vivo.

METHODS

The adenovirus (Ad)-mediated murine SVV gene was transfected into rat aortic endothelial cells (RAECs). RAECs expressing green fluorescent protein after transfection with Ad served as a negative control and those without transfection as a blank control. Then, the SVV mRNA was detected by quantitative real time RT-PCR. The SVV protein, cell cycle and apoptosis related proteins, and matrix metalloproteinase (MMPs) were detected by western blot assay. Immunofluorescence staining was conducted for proliferating cell nuclear antigen and MTT assay for cell viability. Transwell and matrigel chamber assay were employed to assess the migration and invasion of cells after transfection. TUNEL staining and flow cytometry were performed to detect the apoptotic REACs after treatment with anti-Fas antibody. Tube formation in matrigel membranes and matrigel plugs assay in nude mice were employed to confirm the angiogenic capacity in vitro and in vivo, respectively.

RESULTS

The mRNA and protein expressions of SVV increased significantly in SVV transfected cells. The SVV transfected cells showed increased cell proliferation, up-regulated expressions of cell cycle proteins, enhanced invasiveness and migration activities and increased expressions of MMP-2, 7 and 9. In addition, SVV protected against apoptosis of RAECs by inactivating caspase-3, 8 and 9. The tube formation and matrigel plugs assays showed SVV significantly increased blood vessels in vitro and in vivo.

CONCLUSION

SVV may act as an angiogenic factor and used for therapeutic angiogenesis in peripheral arterial diseases.

The Angiogenic Effect of microRNA-21 Targeting TIMP3 through the Regulation of MMP2 and MMP9

microRNAs are a novel set of small, non-protein-coding nucleotide RNAs that negatively regulate the expression of target mRNAs. miRNA-21 is a microRNA that is highly enriched in endothelial cells. miRNA-21 has been shown to be a potential pro-angiogenic factor in some biological systems. Our previous study showed that the expression of miRNA-21 was up-regulated after spinal cord injury. However, the effect of miRNA-21 on angiogenesis in the spinal cord was unclear. In this study, to understand the role of miRNA-21 on injured endothelial cells exclusively, an oxygen and glucose deprivation model of endothelial cells was constructed, and the up-regulation of miRNA-21 was discovered in this model. An increased level of miRNA-21 by mimics promoted the survival, migration and tube formation of endothelial cells, which simultaneously inhibited tissue inhibitor of metalloproteinase-3 (TIMP3) expression and promoted matrix metalloproteinase-2 (MMP2) and matrix metalloproteinase-9 (MMP9) expression and secretion. A decreased level of miRNA-21 by antagomir exerted an opposite effect. As is well known, survival, migration and tube formation of endothelial cells are necessary prerequisites for angiogenesis after injury. TIMP3 was validated as a direct target of miRNA-21 by dual-luciferase reporter assay. Silencing with small interfering RNA against TIMP3 promoted tube formation and increased MMP2 and MMP9 expression at the protein level. In vivo, we found that decreased levels of miRNA-21 inhibited angiogenesis after spinal cord injury in rats using synchrotron radiation micro-computed tomography. In summary, these findings suggest that miRNA-21 has a protective effect on angiogenesis by reducing cell death and promoting cell survival, migration and tube formation via partially targeting the TIMP3 by potentially regulating MMP2 and MMP9. TIMP3 is a functional target gene. Identifying the role of miRNA-21 in the protection of angiogenesis might offer a novel therapeutic target for secondary spinal cord injury, in which angiogenesis is indispensable.

Endostatin and endorepellin: A common route of action for similar angiostatic cancer avengers

Traditional cancer therapy typically targets the tumor proper. However, newly-formed vasculature exerts a major role in cancer development and progression. Autophagy, as a biological mechanism for clearing damaged proteins and oxidative stress products released in the tumor milieu, could help in tumor resolution by rescuing cells undergoing modifications or inducing autophagic-cell death of tumor blood vessels. Cleaved fragments of extracellular matrix proteoglycans are emerging as key players in the modulation of angiogenesis and endothelial cell autophagy. An essential characteristic of cancer progression is the remodeling of the basement membrane and the release of processed forms of its constituents. Endostatin, generated from collagen XVIII, and endorepellin, the C-terminal segment of the large proteoglycan perlecan, possess a dual activity as modifiers of both angiogenesis and endothelial cell autophagy. Manipulation of these endogenously-processed forms, located in the basement membrane within tumors, could represent new therapeutic approaches for cancer eradication.

Macrophages: An Inflammatory Link Between Angiogenesis and Lymphangiogenesis

Angiogenesis and lymphangiogenesis often occur in response to tissue injury or in the presence of pathology (e.g., cancer), and it is these types of environments in which macrophages are activated and increased in number. Moreover, the blood vascular microcirculation and the lymphatic circulation serve as the conduits for entry and exit for monocyte-derived macrophages in nearly every tissue and organ. Macrophages both affect and are affected by the vessels through which they travel. Therefore, it is not surprising that examination of macrophage behaviors in both angiogenesis and lymphangiogenesis has yielded interesting observations that suggest macrophages may be key regulators of these complex growth and remodeling processes. In this review, we will take a closer look at macrophages through the lens of angiogenesis and lymphangiogenesis, examining how their dynamic behaviors may regulate vessel sprouting and function. We present macrophages as a cellular link that spatially and temporally connects angiogenesis with lymphangiogenesis, in both physiological growth and in pathological adaptations, such as tumorigenesis. As such, attempts to therapeutically target macrophages in order to affect these processes may be particularly effective, and studying macrophages in both settings will accelerate the field's understanding of this important cell type in health and disease.

Hydroquinone stimulates cell invasion through activator protein-1-dependent induction of MMP-9 in HepG2 human hepatoma cells

Hydroquinone (HQ) is a well-known environmental carcinogen and exposure of humans to HQ can also occur through plant foods, cosmetics, and tobacco products. Although liver is a major organ metabolizing HQ and susceptible to its toxicity, role of HQ in metastatic progression of human hepatocellular carcinoma (HCC) remains unclear. In this study, we examined the effect of HQ on the invasion of HCC cells and its underlying molecular mechanisms. HQ strongly induced matrix metalloproteinase-9 (MMP-9) expression and secretion in HepG2 human hepatoma cells, which were well correlated with increased cell invasion. Mechanistic studies further demonstrated that HQ induced transcriptional activity of MMP-9 gene by activating activator protein-1 (AP-1), the well-known key element mediating MMP-9 gene expression, via MAP kinase (MAPK) signaling pathways. These results suggest that HQ may promote metastatic progression of HCC, although data on in vivo hydroquinone exposure and risk for HCC are contradictory.

New frontiers in fibrotic disease therapies: The focus of the Joan and Joel Rosenbloom Center for Fibrotic Diseases at Thomas Jefferson University

Fibrotic diseases constitute a world-wide major health problem, but research support remains inadequate in comparison to the need. Although considerable understanding of the pathogenesis of fibrotic reactions has been attained, no completely effective therapies exist. Although fibrotic disorders are diverse, it is universally appreciated that a particular cell type with unique characteristics, the myofibroblast, is responsible for replacement of functioning tissue with non-functional scar tissue. Understanding the cellular and molecular mechanisms responsible for the creation of myofibroblasts and their activities is central to the development of therapies. Critical signaling cascades, initiated primarily by TGF-β, but also involving other cytokines which stimulate pro-fibrotic reactions in the myofibroblast, offer potential therapeutic targets. However, because of the multiplicity and complex interactions of these signaling pathways, it is very unlikely that any single drug will be successful in modifying a major fibrotic disease. Therefore, we have chosen to examine the effectiveness of administration of several drug combinations in a mouse pneumoconiosis model. Such treatment proved to be effective. Because fibrotic diseases that tend to be chronic, are difficult to monitor, and are patient variable, implementation of clinical trials is difficult and expensive. Therefore, we have made efforts to identify and validate non-invasive biomarkers found in urine and blood. We describe the potential utility of five such markers: (i) the EDA form of fibronectin (Fn(EDA)), (ii) lysyl oxidase (LOX), (iii) lysyl oxidase-like protein 2 (LoxL2), (iv) connective tissue growth factor (CTGF, CCNII), and (v) the N-terminal propeptide of type III procollagen (PIIINP).

Blood-brain Barrier Remodeling during Brain Metastasis Formation

Our understanding of the process of metastatic progression has improved markedly over the past decades, yet metastasis remains the most enigmatic component of cancer pathogenesis. This lack of knowledge has serious health-related implications, since metastasis is responsible for 90% of all cancer-related mortalities. The brain is considered a sanctuary site for metastatic tumor growth, where the blood-brain barrier (BBB) and other components of the brain microenvironment, provide protection to the tumor cells from immune surveillance, chemotherapeutics and other potentially harmful substances. The interactions between tumor cells and the brain microenvironment, principally brain vascular endothelium, are the critical determinants in their progression toward metastasis, dormancy, or clearance. This review discusses current knowledge of the biology of metastatic progression, with a particular focus on the tumor cell migration and colonization in the brain.

Pharmacodynamic considerations in the use of matrix metalloproteinase inhibitors in cancer treatment

INTRODUCTION

Matrix metalloproteinases (MMPs) are classified in the family of zinc-dependent endopeptidases, which can degrade various components of an extracellular matrix and a basement membrane. Studies have demonstrated that MMPs relate to the development of malignant tumors and induce angiogenesis, resulting in the invasion and metastasis of tumor cells. MMPs are highly expressed in malignant tumors and are related to cancer patients' malignant phenotype and poor prognosis. Therefore, blocking the expression or activity of MMPs may be a promising strategy for cancer treatment.

AREAS COVERED

This study aimed to explain the MMP structure, regulatory mechanism, and carcinogenic effect; investigate the matrix metalloproteinase-inhibitors (MMPIs) that are currently used in clinical trials for cancer treatment; and summarize the trial results.

EXPERT OPINION

Currently, the results of clinical trials that have used MMPIs as anticancer agents are unsatisfactory. However, MMPs remain an attractive target for cancer treatment. For example, development of the specific peptide or antibodies in targeting the hemopexin domain of MMP-2 may be a new therapeutic direction. The design and development of MMPIs that have selectivity will be the primary focus in future studies.

Neutrophils in Cancer: Two Sides of the Same Coin

Neutrophils are the most abundant leukocytes in blood and are considered to be the first line of defense during inflammation and infections. In addition, neutrophils are also found infiltrating many types of tumors. Tumor-associated neutrophils (TANs) have relevant roles in malignant disease. Indeed neutrophils may be potent antitumor effector cells. However, increasing clinical evidence shows TANs correlate with poor prognosis. The tumor microenvironment controls neutrophil recruitment and in turn TANs help tumor progression. Hence, TANs can be beneficial or detrimental to the host. It is the purpose of this review to highlight these two sides of the neutrophil coin in cancer and to describe recent studies that provide some light on the mechanisms for neutrophil recruitment to the tumor, for neutrophils supporting tumor progression, and for neutrophil activation to enhance their antitumor functions.

Evodiamine Attenuates PDGF-BB-Induced Migration of Rat Vascular Smooth Muscle Cells through Activating PPARγ

The uncontrolled migration of vascular smooth muscle cells (VSMCs) into the intima is a critical process in the development of atherosclerosis. Evodiamine, an indole alkaloid extracted from the Chinese medicine evodia, has been shown to inhibit tumor cell invasion and protect the cardiovascular system, but its effects on VSMCs remain unknown. In the present study, we investigated the inhibitory effects of evodiamine on the platelet-derived growth factor-BB (PDGF-BB)-induced VSMC migration using wound healing and transwell assays, and assessed its role in decreasing the protein levels of matrix metalloproteinases and cell adhesion molecules. More importantly, we found that evodiamine activated the expression and nuclear translocation of peroxisome proliferator-activated receptor γ (PPARγ). Inhibition of PPARγ activity by using its antagonist T0070907 and its specific siRNA oligonucleotides significantly attenuated the inhibitory effects of evodiamine on VSMC migration. Taken together, our results indicate a promising anti-atherogenic effect of evodiamine through attenuation of VSMC migration by activating PPARγ.

Increased matrix metalloproteinase-2 expression and reduced tissue factor pathway inhibitor-2 expression correlate with angiogenesis and early postoperative recurrence of pancreatic carcinoma

Matrix metalloproteinase (MMP)-2 and tissue factor pathway inhibitor (TFPI)-2 are known to influence tumor angiogenesis and progression. This work aimed to describe the levels of MMP-2 and TFPI-2 expression associated with tumor angiogenesis and early postoperative recurrence in patients with pancreatic carcinoma. Expression of MMP-2 and TFPI-2 in carcinoma tissues and paracarcinomatous tissues was assayed by immunostaining. Expression of vascular endothelial growth factor (VEGF) and CD34 in tumor tissues was also assayed by immunostaining. The correlations of MMP-2 and TFPI-2 with VEGF, microvessel density (MVD), and early postoperative recurrence were analyzed. The results showed that MMP-2 expression was significantly increased (P < 0.05) and TFPI-2 expression was significantly decreased (P < 0.001) in carcinoma tissues compared with paracarcinomatous tissues. MMP-2 expression was positively correlated with VEGF (r = 0.594, P < 0.001) and MVD (r = 0.432, P < 0.001) in carcinoma tissues. TFPI-2 expression was negatively correlated with VEGF (r = -0.654, P < 0.001) and MVD (r = -0.360, P < 0.001) in carcinoma tissues. Multivariate logistic regression analysis showed that up-regulated MMP-2 and down-regulated TFPI-2 were independent predictors of early postoperative recurrence of pancreatic carcinoma. Receiver operating characteristic curve analysis showed that the combination of MMP-2 and TFPI-2 was a reliable predictive model of early recurrence. We conclude that increased MMP-2 expression and reduced TFPI-2 expression are closely linked to angiogenesis and early postoperative recurrence of pancreatic carcinoma. Immunohistochemical assay of MMP-2 and TFPI-2 may be useful for predicting early relapse of pancreatic carcinoma after surgery.

Active site specificity profiling of the matrix metalloproteinase family: Proteomic identification of 4300 cleavage sites by nine MMPs explored with structural and synthetic peptide cleavage analyses

Secreted and membrane tethered matrix metalloproteinases (MMPs) are key homeostatic proteases regulating the extracellular signaling and structural matrix environment of cells and tissues. For drug targeting of proteases, selectivity for individual molecules is highly desired and can be met by high yield active site specificity profiling. Using the high throughput Proteomic Identification of protease Cleavage Sites (PICS) method to simultaneously profile both the prime and non-prime sides of the cleavage sites of nine human MMPs, we identified more than 4300 cleavages from P6 to P6' in biologically diverse human peptide libraries. MMP specificity and kinetic efficiency were mainly guided by aliphatic and aromatic residues in P1' (with a ~32-93% preference for leucine depending on the MMP), and basic and small residues in P2' and P3', respectively. A wide differential preference for the hallmark P3 proline was found between MMPs ranging from 15 to 46%, yet when combined in the same peptide with the universally preferred P1' leucine, an unexpected negative cooperativity emerged. This was not observed in previous studies, probably due to the paucity of approaches that profile both the prime and non-prime sides together, and the masking of subsite cooperativity effects by global heat maps and iceLogos. These caveats make it critical to check for these biologically highly important effects by fixing all 20 amino acids one-by-one in the respective subsites and thorough assessing of the inferred specificity logo changes. Indeed an analysis of bona fide MEROPS physiological substrate cleavage data revealed that of the 37 natural substrates with either a P3-Pro or a P1'-Leu only 5 shared both features, confirming the PICS data. Upon probing with several new quenched-fluorescent peptides, rationally designed on our specificity data, the negative cooperativity was explained by reduced non-prime side flexibility constraining accommodation of the rigidifying P3 proline with leucine locked in S1'. Similar negative cooperativity between P3 proline and the novel preference for asparagine in P1 cements our conclusion that non-prime side flexibility greatly impacts MMP binding affinity and cleavage efficiency. Thus, unexpected sequence cooperativity consequences were revealed by PICS that uniquely encompasses both the non-prime and prime sides flanking the proteomic-pinpointed scissile bond.

Current mechanistic insights into the roles of matrix metalloproteinases in tumour invasion and metastasis

The purpose of this review is to highlight the recent mechanistic developments elucidating the role of matrix metalloproteinases (MMPs) in tumour invasion and metastasis. The ability of tumour cells to invade, migrate, and subsequently metastasize is a fundamental characteristic of cancer. Tumour invasion and metastasis are increasingly being characterized by the dynamic relationship between cancer cells and their microenvironment and developing a greater understanding of these basic pathological mechanisms is crucial. While MMPs have been strongly implicated in these processes as a result of extensive circumstantial evidence--for example, increased expression of individual MMPs in tumours and association of specific MMPs with prognosis--the underpinning mechanisms are only now being elucidated. Recent studies are now providing a mechanistic basis, highlighting and reinforcing the catalytic and non-catalytic roles of specific MMPs as key players in tumour invasion and metastasis.

Synthesis of chiral ND-322, ND-364 and ND-364 derivatives as selective inhibitors of human gelatinase

Compounds 10 (ND-322) and 15 (ND-364) are potent selective inhibitors for gelatinases, matrix metalloproteinase 2 (MMP2) and matrix metalloproteinase 9 (MMP9). However, both of them are racemates. Herein we report facile synthesis of optically active (R)- and (S)-enantiomers of compounds 10 and 15. And the sulfonyl of 15 was transformed to sulfinyl to obtain four epimeric mixtures. All synthesized thiirane-based compounds were evaluated in MMP2 and MMP9 inhibitory assays. Our results indicated that the configuration of thiirane moiety had little effects on gelatinase inhibition, but the substitution of sulfinyl for sulfonyl was detrimental to gelatinase inhibition. Besides, all target compounds exhibited no inhibition against other two Zn(2+) dependant metalloproteases, aminopeptidase N (APN) and histone deacetylases (HDACs), which confirmed the unique Zn(2+) chelation mechanism of thiirane moiety against gelatinases.