Pleiotropic roles of matrix metalloproteinases in tumor angiogenesis: contrasting, overlapping and compensatory functions

Immune Cell Migration to Cancer

Immune cell migration is required for the development of an effective and robust immune response. This elegant process is regulated by both cellular and environmental factors, with variables such as immune cell state, anatomical location, and disease state that govern differences in migration patterns. In all cases, a major factor is the expression of cell surface receptors and their cognate ligands. Rapid adaptation to environmental conditions partly depends on intrinsic cellular immune factors that affect a cell's ability to adjust to new environment. In this review, we discuss both myeloid and lymphoid cells and outline key determinants that govern immune cell migration, including molecules required for immune cell adhesion, modes of migration, chemotaxis, and specific chemokine signaling. Furthermore, we summarize tumor-specific elements that contribute to immune cell trafficking to cancer, while also exploring microenvironment factors that can alter these cellular dynamics within the tumor in both a pro and antitumor fashion. Specifically, we highlight the importance of the secretome in these later aspects. This review considers a myriad of factors that impact immune cell trajectory in cancer. We aim to highlight the immunotherapeutic targets that can be harnessed to achieve controlled immune trafficking to and within tumors.

A detailed insight of the tumor targeting using nanocarrier drug delivery system

Human struggle against the deadly disease conditions is continued since ages. The contribution of science and technology in fighting against these diseases cannot be ignored exclusively due to the invention of novel procedure and products, extending their size ranges from micro to nano. Recently nanotechnology has been gaining more consideration for its ability to diagnose and treat different cancers. Different nanoparticles have been used to evade the issues related with conservative anticancer delivery systems, including their nonspecificity, adverse effects and burst release. These nanocarriers including, solid lipid nanoparticles (SLNs), liposomes, nano lipid carriers (NLCs), nano micelles, nanocomposites, polymeric and magnetic nanocarriers, have brought revolutions in antitumor drug delivery. Nanocarriers improved the therapeutic efficacy of anticancer drugs with better accumulation at the specific site with sustained release, improved bioavailability and apoptosis of the cancer cells while bypassing the normal cells. In this review, the cancer targeting techniques and surface modification on nanoparticles are discussed briefly with possible challenges and opportunities. It can be concluded that understanding the role of nanomedicine in tumor treatment is significant, and therefore, the modern progressions in this arena is essential to be considered for a prosperous today and an affluent future of tumor patients.

Molecular and phenotypic distinctions of macrophages in tolerant and susceptible to hypoxia rats

Individual hypoxia tolerance is a major influence on the course and outcome of infectious and inflammatory diseases. Macrophages, which play central roles in systemic inflammatory response and other immunity reactions, are subject to functional activation orchestrated by several transcription factors including hypoxia inducible factors (HIFs). HIF-1 expression levels and the lipopolysaccharide (LPS)-induced systemic inflammatory response severity have been shown to correlate with hypoxia tolerance. Molecular and functional features of macrophages, depending on the organisms resistance to hypoxia, can determine the severity of the course of infectious and inflammatory diseases, including the systemic inflammatory response. The purpose is the comparative molecular and functional characterization of non-activated and LPS-activated bone marrow-derived macrophages under normoxia in rats with different tolerance to oxygen deprivation. Hypoxia resistance was assessed by gasping time measurement in an 11,500 m altitude-equivalent hypobaric decompression chamber. Based on the outcome, the animals were assigned to three groups termed 'tolerant to hypoxia' (n = 12), 'normal', and 'susceptible to hypoxia' (n = 13). The 'normal' group was excluded from subsequent experiments. One month after hypoxia resistance test, the blood was collected from the tail vein to isolate monocytes. Non-activated and LPS-activated macrophage cultures were investigated by PCR, flow cytometry and Western blot methods. Gene expression patterns of non-activated cultured macrophages from tolerant and susceptible to hypoxia animals differed. We observed higher expression of VEGF and CD11b and lower expression of Tnfa, Il1b and Epas1 in non-activated cultures obtained from tolerant to hypoxia animals, whereas HIF-1α mRNA and protein expression levels were similar. LPS-activated macrophage cultures derived from susceptible to hypoxia animals expressed higher levels of Hif1a and CCR7 than the tolerant group; in addition, the activation was associated with increased content of HIF-1α in cell culture medium. The observed differences indicate a specific propensity toward pro-inflammatory macrophage polarization in susceptible to hypoxia rats.

Association of MMP1 gene polymorphisms with breast cancer risk: A narrative review

Background and Aims

Breast cancer is a multifactorial malignancy with different clinicopathological and molecular characteristics. It is the most frequent cancer in women in terms of both incidence and mortality. Matrix metallopeptidase 1 or MMP1 is a zinc-dependent endopeptidase associated with several physiological processes through the modification of the extracellular matrix and tumor microenvironment. However, previous results did not suggest any concluding remarks on the correlation between MMP1 gene polymorphisms and the risk of breast cancer.

Methods

A comprehensive literature search was performed in PubMed database to retrieve relevant articles and extract data from suitable ones. The literature written only in English was selected for this review.

Results

A total of 26 articles were included in the present narrative review. From the available studies, it is observed that MMP1 is upregulated in breast cancer tissues and found to be correlated with metastasis and invasion. The expression of MMP1 gene is mediated by numerous factors, including polymorphisms which act as a potential risk factor for the progression of breast cancer. To establish the correlation between genetic polymorphisms in MMP1 and the risk of breast cancer, several case-control studies, as well as genetic analyses, have been carried out in different ethnicities. The association of genetic polymorphisms in MMP1 with the risk and survival of breast cancer in different populations has been reviewed in this study. Moreover, the structural domain of MMP1 and the role of MMP1 in breast cancer metastasis and invasion are also discussed which will help to understand the potential impact of MMP1 as a genetic biomarker.

Conclusions

This review provides an overview of the MMP1 gene polymorphisms in breast cancer. However, we recommend future studies concentrating on combined analysis of multiple SNPs, gene-gene interactions, and analysis of epigenetics, proteomics, and posttranscriptional modifications that will provide the best outcome.

MMP-9 reinforces radiation-induced delayed invasion and metastasis of neuroblastoma cells through second-signaling positive feedback with NFκB via both ERK and IKK activation

Neuroblastoma (NB) progression is branded with hematogenous metastasis and frequent relapses. Despite intensive multimodal clinical therapy, outcomes for patients with progressive disease remain poor, with negligible long-term survival. Therefore, understanding the acquired molecular rearrangements in NB cells with therapy pressure and developing improved therapeutic strategies is a critical need to improve the outcomes for high-risk NB patients. We investigated the rearrangement of MMP9 in NB with therapy pressure, and unveiled the signaling that facilitates NB evolution. Radiation-treatment (RT) significantly increased MMP9 expression/activity, and the induced enzyme activity was persistently maintained across NB cell lines. Furthermore, RT-triggered NFκB transcriptional activity and this RT-induced NFκB were required/adequate for MMP9 maintenance. RT-triggered NFκB-dependent MMP9 actuated a second-signaling feedback to NFκB, facilitating a NFκB-MMP9-NFκB positive feedback cycle (PFC). Critically, MMP9-NFκB feedback is mediated by MMP9-dependent activation of IKKβ and ERK phosphotransferase activity. Beyond its tumor invasion/metastasis function, PFC-dependent MMP9 lessens RT-induced apoptosis and favors survival pathway through the activation of NFκB signaling. In addition, PFC-dependent MMP9 regulates 19 critical molecular determinants that play a pivotal role in tumor evolution. Interestingly, seven of 19 genes possess NFκB-binding sites, demonstrating that MMP9 regulates these molecules by activating NFκB. Collectively, these data suggest that RT-triggered NFκB-dependent MMP9 actuates feedback to NFκB though IKKβ- and ERK1/2-dependent IκBα phosphorylation. This RT-triggered PFC prompts MMP9-dependent survival advantage, tumor growth, and dissemination. Targeting therapy-pressure-driven PFC and/or selective inhibition of MMP9 maintenance could serve as promising therapeutic strategies for treatment of progressive NB.

Emerging advances in engineered macrophages for tumor immunotherapy

Macrophages are versatile antigen-presenting cells. Recent studies suggest that engineered modifications of macrophages may confer better tumor therapy. Genetic engineering of macrophages with specific chimeric antigen receptors offers new possibilities for treatment of solid tumors and has received significant attention. In vitro gene editing of macrophages and infusion into the body can inhibit the immunosuppressive effect of the tumor microenvironment in solid tumors. This strategy is flexible and can be applied to all stages of cancer treatment. In contrast, nongenetic engineering tools are used to block relevant signaling pathways in immunosuppressive responses. In addition, macrophages can be loaded with drugs and engineered into cellular drug delivery systems. Here, we analyze the effect of the chimeric antigen receptor platform on macrophages and other existing engineering modifications of macrophages, highlighting their status, challenges and future perspectives. Indeed, our analyses show that new approaches in the treatment of solid tumors will likely exploit macrophages, an innate immune cell.

Base-Exchange Enabling the Visualization of SARM1 Activities in Sciatic Nerve-Injured Mice

Enzymes are important in homeostasis in living organisms. Since abnormal enzyme activities are highly associated with many human diseases, detection of in vivo activities of a specific enzyme is important to study the pathology of the related diseases. In this work, we have designed and synthesized a series of new small-molecule-activatable fluorescent probes for the imaging of Sterile Alpha and TIR Motif-containing 1 (SARM1) activities based on its transglycosidase activities (base-exchange reactions of NAD⁺). Probe 1a was found to undergo base-exchange reactions with NAD⁺ in the presence of activated SARM1 but not CD38 nor NADase and formed a highly emissive product AD-1a [about a 100-fold fluorescence enhancement in 20 min with a 150 nm (5665 cm^-1) Stokes shift and a 100 nm (3812 cm^-1) red shift]. This probe exhibited a higher reactivity and sensitivity than those commonly used for SARM1 imaging. The utilities of 1a have also been demonstrated in live-cell imaging and detection of in vivo activities of SARM1 in a sciatic nerve injury mouse model.

Characterization of Active MMP9 in Chronic Inflammatory Diseases Using a Novel Anti-MMP9 Antibody

Matrix metalloproteinase 9 (MMP9), a protease implicated in multiple diseases, is secreted as an inactive zymogen and requires proteolytic removal of the pro-domain for activation. The relative levels and functionality of the pro- and active-MMP9 isoforms in tissues are not characterized. We generated a specific antibody that distinguishes an active form of MMP9, F107-MMP9, from the inactive pro-MMP9 isoform. Using multiple in vitro assays and specimen types, we show that F107-MMP9 expression is localized and disease-specific compared with its more abundant parental pro-form. It is detected around sites of active tissue remodeling, including fistulae of inflammatory bowel and dermal fissures in hidradenitis suppurativa, and is expressed by myeloid cells, including macrophages and neutrophils. Together, our findings provide insights into the distribution and potential role of MMP9 in inflammatory diseases.

Olive leaf extract inhibits metastatic melanoma spread through suppression of epithelial to mesenchymal transition

Olive tree leaves are an abundant source of bioactive compounds with several beneficial effects for human health, including a protective role against many types of cancer. In this study, we investigated the effect of an extract, obtained from olive tree (Olea europaea L.) leaves (OLE), on proliferation, invasion, and epithelial to mesenchymal transition (EMT) on metastatic melanoma, the highly aggressive form of skin cancer and the deadliest diseases. Our results demonstrated that OLE inhibited melanoma cells proliferation through cell cycle arrest and induction of apoptotic cell death. Moreover, OLE suppressed the migration, invasion, and colonies formation of human melanoma cells. Similar to our in vitro findings, we demonstrated that the oral administration of OLE inhibited cutaneous tumor growth and lung metastasis formation in vivo by modulating the expression of EMT related factors. In addition, the anti-proliferative and anti-invasive effects of OLE against melanoma were also related to a simultaneous targeting of mitogen-activated protein kinase and PI3K pathways, both in vitro and in vivo. In conclusion, our findings suggest that OLE has the potential to inhibit the metastatic spread of melanoma cells thanks to its multifaceted mechanistic effects, and may represent a new add-on therapy for the management of metastatic melanoma.

A glitch in the matrix: the pivotal role for extracellular matrix remodeling during muscle hypertrophy

Multinuclear muscle fibers are the most voluminous cells in skeletal muscle and the primary drivers of growth in response to loading. Outside the muscle fiber, however, is a diversity of mononuclear cell types that reside in the extracellular matrix (ECM). These muscle-resident cells are exercise-responsive and produce the scaffolding for successful myofibrillar growth. Without proper remodeling and maintenance of this ECM scaffolding, the ability to mount an appropriate response to resistance training in adult muscles is severely hindered. Complex cellular choreography takes place in muscles following a loading stimulus. These interactions have been recently revealed by single-cell explorations into muscle adaptation with loading. The intricate ballet of ECM remodeling involves collagen production from fibrogenic cells and ECM modifying signals initiated by satellite cells, immune cells, and the muscle fibers themselves. The acellular collagen-rich ECM is also a mechanical signal-transducer and rich repository of growth factors that may directly influence muscle fiber hypertrophy once liberated. Collectively, high levels of collagen expression, deposition, and turnover characterize a well-trained muscle phenotype. The purpose of this review is to highlight the most recent evidence for how the ECM and its cellular components affect loading-induced muscle hypertrophy. We also address how the muscle fiber may directly take part in ECM remodeling, and whether ECM dynamics are rate limiting for muscle fiber growth.

The Vascular Microenvironment in Glioblastoma: A Comprehensive Review

Glioblastoma multiforme, the deadliest primary brain tumor, is characterized by an excessive and aberrant neovascularization. The initial expectations raised by anti-angiogenic drugs were soon tempered due to their limited efficacy in improving the overall survival. Intrinsic resistance and escape mechanisms against anti-VEGF therapies evidenced that tumor angiogenesis is an intricate multifaceted phenomenon and that vessels not only support the tumor but exert indispensable interactions for resistance and spreading. This holistic review covers the essentials of the vascular microenvironment of glioblastoma, including the perivascular niche components, the vascular generation patterns and the implicated signaling pathways, the endothelial–tumor interrelation, and the interconnection between vessel aberrancies and immune disarrangement. The revised concepts provide novel insights into the preclinical models and the potential explanations for the failure of conventional anti-angiogenic therapies, leading to an era of new and combined anti-angiogenic-based approaches.

Germline Variants in Angiogenesis-Related Genes Contribute to Clinical Outcome in Head and Neck Squamous Cell Carcinoma

Simple Summary

A high risk of relapse and treatment resistance are among the major challenges in locally advanced head and neck squamous cell carcinoma (HNSCC). Data show that common germline alterations in genes regulating angiogenesis may modulate treatment sensitivity, cancer progression, and prognosis, but relatively little is known about their role in HNSCC. Thus, our goal was to examine the effect of variation in these genes on survival outcomes in HNSCC patients receiving radiotherapy and cisplatin-based chemoradiotherapy. We identified genetic variants significantly affecting therapy results, constituting independent prognostic factors in these patients. Our results suggest that some polymorphisms in angiogenesis genes may be determinants of treatment efficacy and tumor aggressiveness in HNSCC, which may be of importance in standard therapy. These findings emphasize the potential value of the host genetic profile related to angiogenesis in assessing the risk of treatment failure.

Abstract

Fibroblast growth factor (FGF)/FGF receptor (FGFR), and platelet-derived growth factor (PDGF)/PDGF receptor (PDGFR) systems, as well as some matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs), are involved in various steps of angiogenesis. Data indicate that common germline variations in angiogenesis-regulating genes may modulate therapy results and cancer progression. However, whether these variants affect clinical outcome in head and neck squamous cell carcinoma (HNSCC) is unclear. Hence, we assessed the relationship between FGF/FGFR, PDGF/PDGFR, MMP, and TIMP genetic variants and treatment outcomes in HNSCC patients receiving radiotherapy (RT) alone or combined with cisplatin-based chemotherapy. In multivariate analysis, FGF2 rs1048201 CC homozygotes showed a higher risk of death (p = 0.039), while PDGFRA rs2228230 T was strongly associated with an increased risk of locoregional relapse (HR 2.49, p = 0.001) in the combination treatment subgroup. In the RT alone subset, MMP2 rs243865 TT carriers had a higher risk of locoregional recurrence (HR 2.92, p = 0.019), whereas PDGFRB rs246395 CC homozygotes were at increased risk of metastasis (HR 3.06, p = 0.041). The MMP2 rs7201 C and TIMP2 rs7501477 T were associated with a risk of locoregional failure in the entire cohort (p = 0.032 and 0.045, respectively). Furthermore, rs1048201, rs2228230, rs246395, rs243865, rs7201, and rs7201/rs7501477 were independent indicators of an unfavorable outcome. This study demonstrates that the FGF2, PDGFRA, PDGFRB, MMP2, and TIMP2 variants may contribute to treatment failure and poor prognosis in HNSCC.

Comparison between Heat-Clearing Medicine and Antirheumatic Medicine in Treatment of Gastric Cancer Based on Network Pharmacology, Molecular Docking, and Tumor Immune Infiltration Analysis

Background

Clinical research found that TCM is therapeutic in treating gastric cancer. Clearing heat is the most common method, while some antirheumatic medicines are widely used in treatment as well. To explore the pharmacological mechanism, we researched the comparison between heat-clearing medicine and antirheumatic medicine in treating gastric cancer.

Methods

First, related ingredients and targets were searched, respectively, and are shown in an active ingredient-target network. Combining the relevant targets of gastric cancer, we constructed a PPI network and MCODE network. Then, GO and KEGG enrichment analyses were conducted. Molecular docking experiments were performed to verify the affinity of targets and ligands. Finally, we analyzed the tumor immune infiltration on gene expression, somatic CNA, and clinical outcome.

Results

A total of 31 ingredients and 90 targets of heat-clearing medicine, 31 ingredients and 186 targets of antirheumatic medicine, and 12,155 targets of gastric cancer were collected. Antirheumatic medicine ranked the top in all the enrichment analyses. In the KEGG pathway, both types of medicines were related to pathways in cancer. In the KEGG map, AR, MMP2, ERBB2, and TP53 were the most crucial targets. Key targets and ligands were docked with low binding energy. Analysis of tumor immune infiltration showed that the expressions of AR and ERBB2 were correlated with the abundance of immune infiltration and made a difference in clinical outcomes.

Conclusions

Quercetin is an important ingredient in both heat-clearing medicine and antirheumatic medicine. AR signaling pathway exists in both types of medicines. The mechanism of the antitumor effect in antirheumatic medicine was similar to trastuzumab, a targeted drug aimed at ERBB2. Both types of medicines were significant in tumor immune infiltration. The immunology of gastric tumor deserves further research.

Polymorphonuclear Neutrophils and Tumors: Friend or Foe?

Tumor microenvironment (TME) is a dynamic network that apart from tumor cells includes also cells of the immune system, e.g., neutrophils, which are recruited from blood circulation. In TME, neutrophils are strongly implicated in the direct and indirect interactions with tumor cells or other immune cells, and they play roles in both preventing and/or facilitating tumor progression and metastasis. The dual role of neutrophils is determined by their high plasticity and heterogeneity. Analogous to the macrophages, neutrophils can express antitumoral (N1) and protumoral (N2) phenotypes which differ substantially in morphology and function. N1 phenotype characterizes with a high cytotoxic and proinflammatory activities, while N2 phenotype with immunosuppressive and prometastatic properties. The antitumoral effect of neutrophils includes for example the production of reactive oxygen species or proapoptotic molecules. The protumoral action of neutrophils relies on releasing of proangiogenic and prometastatic mediators, immunosuppressive factors, as well as on direct helping tumor cells in extravasation process. This chapter summarizes the heterogeneity of neutrophils in TME, as well as their dual role on tumor cells.

Randomized, open-label, phase 2 study of andecaliximab plus nivolumab versus nivolumab alone in advanced gastric cancer identifies biomarkers associated with survival

Background

Matrix metalloproteinase-9 (MMP9) selectively cleaves extracellular matrix proteins contributing to tumor growth and an immunosuppressive microenvironment. This study evaluated andecaliximab (ADX), an inhibitor of MMP9, in combination with nivolumab (NIVO), for the treatment of advanced gastric cancer.

Methods

Phase 2, open-label, randomized multicenter study evaluating the efficacy, safety, and pharmacodynamics of ADX+NIVO versus NIVO in patients with pretreated metastatic gastric or gastroesophageal junction (GEJ) adenocarcinoma. The primary endpoint was objective response rate (ORR). Secondary endpoints included progression-free survival (PFS), overall survival (OS), and adverse events (AEs). We explored the correlation of efficacy outcomes with biomarkers.

Results

144 patients were randomized; 141 were treated: 81% white, 69% male, median age was 61 years in the ADX+NIVO group and 62 years in the NIVO-alone group. The ORR was 10% (95% CI 4 to 19) in the ADX+NIVO group and 7% (95% CI 2 to 16) in the NIVO-alone group (OR: 1.5 (95% CI 0.4 to 6.1; p=0.8)). There was no response or survival benefit associated with adding ADX. AE rates were comparable in both treatment groups; the most common AEs were fatigue, decreased appetite, nausea, and vomiting. Programmed cell death ligand 1, interferon-γ (IFN), and intratumoral CD8+ cell density were not associated with treatment response or survival. The gene signature most correlated with shorter survival was the epithelial-to-mesenchymal gene signature; high transforming growth factor (TGF)-β fibrosis score was negatively associated with OS (p=0.036). Gene expression analysis of baseline tumors comparing long-(1+ years) and short-term (<1 year) survivors showed that GRB7 was associated with survival beyond 1 year. Human epidermal growth factor receptor 2 (HER2)-positive disease was associated with significantly longer survival (p=0.0077). Median tumor mutation burden (TMB) was 2.01; patients with TMB ≥median had longer survival (p=0.0025) and improved PFS (p=0.016). Based on a model accounting for TMB, TGF-β fibrosis, and HER2, TMB was the main driver of survival in this patient population.

Conclusion

Combination of ADX+NIVO had a favorable safety profile but did not improve efficacy compared with NIVO alone in patients with pretreated metastatic gastric or GEJ adenocarcinoma. HER2 positivity, higher TMB or GRB7, and lower TGF-β were associated with improved outcomes.

Trial registration number

NCT02864381 or GS-US-296–-2013.

Metalloproteinases in Endometrial Cancer-Are They Worth Measuring?

Endometrial cancer is one of the most common gynecological malignancies, yet the molecular mechanisms that lead to tumor development and progression are still not fully established. Matrix metalloproteinases (MMPs) are a group of enzymes that play an important role in carcinogenesis. They are proteases involved in the degradation of the extracellular matrix (ECM) that surrounds the tumor and the affected tissue allows cell detachment from the primary tumor causing local invasion and metastasis formation. Recent investigations demonstrate significantly increased metalloproteinase and metalloproteinase inhibitor levels in patients with endometrial cancer compared to those with normal endometrium. In this review, we aim to show their clinical significance and possible use in the diagnosis and treatment of patients with endometrial cancer. We have critically summarized and reviewed the research on the role of MMPs in endometrial cancer.

Microenvironmental modulation of the developing tumour: an immune-stromal dialogue

Successful establishment of a tumour relies on a cascade of interactions between cancer cells and stromal cells within an evolving microenvironment. Both immune and nonimmune cellular components are key factors in this process, and the individual players may change their role from tumour elimination to tumour promotion as the microenvironment develops. While the tumour-stroma crosstalk present in an established tumour is well-studied, aspects in the early tumour or premalignant microenvironment have received less attention. This is in part due to the challenges in studying this process in the clinic or in mouse models. Here, we review the key anti- and pro-tumour factors in the early microenvironment and discuss how understanding this process may be exploited in the clinic.

Immunohistochemical Characterisation of GLUT1, MMP3 and NRF2 in Osteosarcoma

Osteosarcoma (OSA) is an aggressive bone malignancy. Unlike many other malignancies, OSA outcomes have not improved in recent decades. One challenge to the development of better diagnostic and therapeutic methods for OSA has been the lack of well characterized experimental model systems. Spontaneous OSA in dogs provides a good model for the disease seen in people and also remains an important veterinary clinical challenge. We recently used RNA sequencing and qRT-PCR to provide a detailed molecular characterization of OSA relative to non-malignant bone in dogs. We identified differential mRNA expression of the solute carrier family 2 member 1 (SLC2A1/GLUT1), matrix metallopeptidase 3 (MMP3) and nuclear factor erythroid 2–related factor 2 (NFE2L2/NRF2) genes in canine OSA tissue in comparison to paired non-tumor tissue. Our present work characterizes protein expression of GLUT1, MMP3 and NRF2 using immunohistochemistry. As these proteins affect key processes such as Wnt activation, heme biosynthesis, glucose transport, understanding their expression and the enriched pathways and gene ontologies enables us to further understand the potential molecular pathways and mechanisms involved in OSA. This study further supports spontaneous OSA in dogs as a model system to inform the development of new methods to diagnose and treat OSA in both dogs and people.

Matrix metalloproteinase contribution in management of cancer proliferation, metastasis and drug targeting

Matrix metalloproteinases (MMPs) or matrixins, are members of a zinc-dependent endopeptidase family. They cause remodeling of the extracellular matrix (ECM) leading to numerous diseases. MMPs subfamilies possess: collagenases, gelatinases, stromelysins and membrane-type MMPs (MT-MMP). They consist of several domains; pro-peptide, catalytic, linker peptide and the hemopexin (Hpx) domains. MMPs are involved in initiation, proliferation and metastasis of cancer through the breakdown of ECM physical barriers. Overexpression of MMPs is associated with poor prognosis of cancer. This review will discuss both types of MMPs and current inhibitors, which target them in different aspects, including, biosynthesis, activation, secretion and catalytic activity. Several synthetic and natural inhibitors of MMPs (MMPIs) that can bind the catalytic domain of MMPs have been designed including; peptidomimetic, non-peptidomimetic, tetracycline derivatives, off-target MMPI, natural products, microRNAs and monoclonal antibodies.

Extracellular Matrix Components Regulate Bone Sialoprotein Expression in MDA-MB-231 Breast Cancer Cells

Bone sialoprotein (BSP) has become a target in breast cancer research as it is associated with tumor progression and metastasis. The mechanisms underlying the regulation of BSP expression have been largely elusive. Given that BSP is involved in the homing of cancer cells in bone metastatic niches, we addressed regulatory effects of proteolytic cleavage and extracellular matrix components on BSP expression and distribution in cell culture models. Therefore, MDA-MB-231 human breast cancer cells were kept in 2D and 3D spheroid cultures and exposed to basement membrane extract in the presence or absence of matrix metalloproteinase 9 or the non-polar protease, dispase. Confocal imaging of immunofluorescence samples stained with different antibodies against human BSP demonstrated a strong inducing effect of basement membrane extract on anti-BSP immunofluorescence. Similarly, protease incubation led to acute upregulation of anti-BSP immunofluorescence signals, which was blocked by cycloheximide, suggesting de novo formation of BSP. In summary, our data show that extracellular matrix components play an important function in regulating BSP expression and hint at mechanisms for the formation of bone-associated metastasis in breast cancer that might involve local control of BSP levels by extracellular matrix degradation and release of growth factors.

The Role of Tumor Microenvironment in Cancer Metastasis: Molecular Mechanisms and Therapeutic Opportunities

Simple Summary

Metastasis, the process by which cancer cells escape primary tumor site and colonize distant organs, is responsible for most cancer-related deaths. The tumor microenvironment (TME), comprises different cell types, including immune cells and cancer-associated fibroblasts, as well as structural elements, such as collagen and hyaluronan that constitute the extracellular matrix (ECM). Intratumoral interactions between the cellular and structural components of the TME regulate the aggressiveness, and dissemination of malignant cells and promote immune evasion. At the secondary site, the TME also facilitates escape from dormancy to enhance metastatic tumor outgrowth. Moreover, the ECM applies mechanical forces on tumors that contribute to hypoxia and cancer cell invasiveness whereas also hinders drug delivery and efficacy in both primary and metastatic sites. In this review, we summarize the latest developments regarding the role of the TME in cancer progression and discuss ongoing efforts to remodel the TME to stop metastasis in its tracks.

Abstract

The tumor microenvironment (TME) regulates essential tumor survival and promotion functions. Interactions between the cellular and structural components of the TME allow cancer cells to become invasive and disseminate from the primary site to distant locations, through a complex and multistep metastatic cascade. Tumor-associated M2-type macrophages have growth-promoting and immunosuppressive functions; mesenchymal cells mass produce exosomes that increase the migratory ability of cancer cells; cancer associated fibroblasts (CAFs) reorganize the surrounding matrix creating migration-guiding tracks for cancer cells. In addition, the tumor extracellular matrix (ECM) exerts determinant roles in disease progression and cancer cell migration and regulates therapeutic responses. The hypoxic conditions generated at the primary tumor force cancer cells to genetically and/or epigenetically adapt in order to survive and metastasize. In the circulation, cancer cells encounter platelets, immune cells, and cytokines in the blood microenvironment that facilitate their survival and transit. This review discusses the roles of different cellular and structural tumor components in regulating the metastatic process, targeting approaches using small molecule inhibitors, nanoparticles, manipulated exosomes, and miRNAs to inhibit tumor invasion as well as current and future strategies to remodel the TME and enhance treatment efficacy to block the detrimental process of metastasis.

miR-135a Reduces Osteosarcoma Pulmonary Metastasis by Targeting Both BMI1 and KLF4

Because of the modest response rate after surgery and chemotherapy, treatment of osteosarcoma (OS) remains challenging due to tumor recurrence and metastasis. miR-135a has been reported to act as an anticarcinogenic regulator of several cancers. However, its expression and function in osteosarcoma remain largely unknown. Here, we reported that abridged miR-135a expression in OS cells and tissues, and its expression is inversely correlated with the expression of BMI1 and KLF4, which are described as oncogenes in several cancers. Ectopic expression of miR-135a inhibited cell invasion and expression of BMI1 and KLF4 in OS cells. In vivo investigation confirmed that miR-135a acts as a tumor suppressor in OS to inhibit tumor growth and lung metastasis in xenograft nude mice. BMI1 and KLF4 were revealed to be direct targets of miR-135a, and miR-135a had a similar effect as the combination of si-BMI1 and si-KLF4 on inhibiting tumor progression and the expression of BMI1 and KLF4 in vivo. Altogether, our results demonstrate that the targeting of BMI1/KLF4 with miR-135a may provide an applicable strategy for exploring novel therapeutic approaches for OS.

Anti-Metastatic and Anti-Inflammatory Effects of Matrix Metalloproteinase Inhibition by Ginsenosides

Matrix metalloproteinases (MMPs) are proteolytic enzymes which cleave extracellular matrix (ECM) and other substrates. They are deeply involved in both cancer metastasis and human chronic inflammatory diseases such as osteoarthritis and Crohn’s disease. Regulation of MMPs is closely associated with signaling molecules, especially mitogen-activated protein kinases (MAPKs), including three representative kinases, extracellular signal regulated kinases (ERK), p38 and c-Jun N-terminal kinases (JNK). Ginseng (Panax sp.) is a plant which has been traditionally used for medicinal applications. Ginsenosides are major metabolites which have potentials to treat various human diseases. In this review, the pharmacological effects of ginsenosides have been rigorously investigated; these include anti-metastatic and anti-inflammatory activities of ginsenosides associated with suppression of MMPs via regulation of various signaling pathways. This will highlight the importance of MMPs as therapeutic targets for anti-metastatic and anti-inflammatory drug development based on ginsenosides.

The Stemness-High Human Colorectal Cancer Cells Promote Angiogenesis by Producing Higher Amounts of Angiogenic Cytokines via Activation of the Egfr/Akt/Nf-κB Pathway

Purpose: Cancer stem cells (CSCs) are responsible for cancer metastasis by stimulating tumor angiogenesis via various mechanisms. To elucidate the potential of the stemness-high human colorectal cancer (CRC) cells (i.e., CRCSCs) in activating angiogenesis, effects of the GATA6-overexpressing HCT-116 and HT-29 human CRC clones established previously by us in promoting the angiogenesis of human umbilical vein endothelial cells (HUVECs) were examined. Methods: Angiogenesis-promoting effects (i.e., migration, invasion, DNA synthesis, and tube formation) in HUVECs of the conditioned media (CM) from various human CRC clones were analyzed. MMP activities were assessed using a zymography assay. Western blotting and selective inhibitors were used to dissect the signaling pathway involved. IHC was used to examine the vascular density in tumor xenografts. Results: We found that the conditioned media (CM) collected from the GATA6-overexpressing clones enhanced angiogenesis of HUVECs more effectively which might be attributed partly to a higher MMP-9 production by HUVECs. Subsequently, elevated levels of IL-8 and VEGF-A were detected in the CM whose tube formation-enhancing activities were abolished by the co-treatment with either a VEGFR2 inhibitor or an IL-8 neutralizing antibody. Interestingly, increased production of these cytokines in the GATA6-overexpressing clones was due to an EGFR/AKT-mediated activation of NF-κB. Furthermore, not only were the levels of CD31 and endomucin but also the blood vessel density was much higher in the xenograft tumors grown from these clones. Conclusion: Our findings demonstrate that human CRCSCs promote a stronger angiogenesis by producing higher amounts of angiogenic factors through activation of the EGFR/AKT/NF-κB pathway.

REX-001, a BM-MNC Enriched Solution, Induces Revascularization of Ischemic Tissues in a Murine Model of Chronic Limb-Threatening Ischemia

Background: Bone Marrow Mononuclear Cells (BM-MNC) constitute a promising alternative for the treatment of Chronic Limb-Threatening ischemia (CLTI), a disease characterized by extensive blockade of peripheral arteries, clinically presenting as excruciating pain at rest and ischemic ulcers which may lead to gangrene and amputation. BM-MNC implantation has shown to be efficient in promoting angiogenesis and ameliorating ischemic symptoms in CLTI patients. However, the variability seen between clinical trials makes necessary a further understanding of the mechanisms of action of BM-MNC, and moreover, to improve trial characteristics such as endpoints, inclusion/exclusion criteria or drug product compositions, in order to implement their use as stem-cell therapy.

Materials: Herein, the effect of REX-001, a human-BM derived cell suspension enriched for mononuclear cells, granulocytes and CD34+ cells, has been assessed in a murine model of CLTI. In addition, a REX-001 placebo solution containing BM-derived red blood cells (BM-RBCs) was also tested. Thus, 24 h after double ligation of the femoral artery, REX-001 and placebo were administrated intramuscularly to Balb-c nude mice (n:51) and follow-up of ischemic symptoms (blood flow perfusion, motility, ulceration and necrosis) was carried out for 21 days. The number of vessels and vascular diameter sizes were measured within the ischemic tissues to evaluate neovascularization and arteriogenesis. Finally, several cell-tracking assays were performed to evaluate potential biodistribution of these cells.

Results: REX-001 induced a significant recovery of blood flow by increasing vascular density within the ischemic limbs, with no cell translocation to other organs. Moreover, cell tracking assays confirmed a decrease in the number of infused cells after 2 weeks post-injection despite on-going revascularization, suggesting a paracrine mechanism of action.

Conclusion: Overall, our data supported the role of REX-001 product to improve revascularization and ischemic reperfusion in CLTI.

Targeting Tumor-Associated Macrophages by MMP2-Sensitive Apoptotic Body-Mimicking Nanoparticles

Tumor-associated macrophages (TAMs), a major player in the tumor microenvironment, were recently recognized as a potential therapeutic target. To date, very few anticancer drugs or drug-delivery systems were designed to target the TAMs. Inspired by the "eat me" signal, phosphatidylserine (PS), mediated phagocytic clearance of apoptotic bodies, in this study, the matrix metalloproteinase 2 (MMP2)-sensitive PS-modified nanoparticles were developed. In the design, the PS is externalized to the nanoparticles' surface only when the nanoparticles reach the MMP2-overexpressing tumor site, allowing for the TAM-specific phagocytosis. The nanoparticles' excellent macrophage/TAM selectivity was observed in various biological models, including various cell lines, coculture cells, coculture cell spheroids, zebrafish, and tumor-bearing mice. The nanoparticles' TAM specificity remarkably enhanced the TAM depletion capability of the loaded model drug, dasatinib, resulting in the improved anticancer activity. The MMP2-sensitive apoptotic body-mimicking nanoparticles might be a promising delivery tool for TAM-centered cancer diagnoses and treatments.

Resistance to Anti-angiogenic Therapies: A Mechanism Depending on the Time of Exposure to the Drugs

Angiogenesis, the formation of new blood vessels from preexisting one, represents a critical process for oxygen and nutrient supply to proliferating cells, therefore promoting tumor growth and metastasis. The Vascular Endothelial Growth Factor (VEGF) pathway is one of the key mediators of angiogenesis in cancer. Therefore, several therapies including monoclonal antibodies or tyrosine kinase inhibitors target this axis. Although preclinical studies demonstrated strong antitumor activity, clinical studies were disappointing. Antiangiogenic drugs, used to treat metastatic patients suffering of different types of cancers, prolonged survival to different extents but are not curative. In this review, we focused on different mechanisms involved in resistance to antiangiogenic therapies from early stage resistance involving mainly tumor cells to late stages related to the adaptation of the microenvironment.

Fusion-Independent Satellite Cell Communication to Muscle Fibers During Load-Induced Hypertrophy

The "canonical" function of Pax7+ muscle stem cells (satellite cells) during hypertrophic growth of adult muscle fibers is myonuclear donation via fusion to support increased transcriptional output. In recent years, however, emerging evidence suggests that satellite cells play an important secretory role in promoting load-mediated growth. Utilizing genetically modified mouse models of delayed satellite cell fusion and in vivo extracellular vesicle (EV) tracking, we provide evidence for satellite cell communication to muscle fibers during hypertrophy. Myogenic progenitor cell-EV-mediated communication to myotubes in vitro influences extracellular matrix (ECM)-related gene expression, which is congruent with in vivo overload experiments involving satellite cell depletion, as well as in silico analyses. Satellite cell-derived EVs can transfer a Cre-induced, cytoplasmic-localized fluorescent reporter to muscle cells as well as microRNAs that regulate ECM genes such as matrix metalloproteinase 9 (Mmp9), which may facilitate growth. Delayed satellite cell fusion did not limit long-term load-induced muscle hypertrophy indicating that early fusion-independent communication from satellite cells to muscle fibers is an underappreciated aspect of satellite cell biology. We cannot exclude the possibility that satellite cell-mediated myonuclear accretion is necessary to maintain prolonged growth, specifically in the later phases of adaptation, but these data collectively highlight how EV delivery from satellite cells can directly contribute to mechanical load-induced muscle fiber hypertrophy, independent of cell fusion to the fiber.

Urothelial Carcinoma of the Bladder Induces Endothelial Cell Activation and Hypercoagulation

Cancer-related venous thromboembolisms (VTE) are associated with metastasis and reduced survival in patients with urothelial cancer of the bladder. Although previous reports suggest the contribution of tissue factor and podoplanin, the mechanistic linkage between VTE and bladder cancer cell-derived molecules is unknown. Therefore, we compared distinct procoagulant pathways in four different cell lines. In vitro findings were further confirmed by microfluidic experiments mimicking the pathophysiology of tumor blood vessels and in tissue samples of patients with bladder cancer by transcriptome analysis and immunohistology. In vitro and microfluidic experiments identified bladder cancer-derived VEGF-A as highly procoagulant because it promoted the release of von Willebrand factor (VWF) from endothelial cells and thus platelet aggregation. In tissue sections from patients with bladder cancer, we found that VWF-mediated blood vessel occlusions were associated with a poor outcome. Transcriptome data further indicate that elevated expression levels of enzymes modulating VEGF-A availability were significantly connected to a decreased survival in patients with bladder cancer. In comparison with previously postulated molecular players, we identified tumor cell-derived VEGF-A and endothelial VWF as procoagulant mediators in bladder cancer. Therapeutic strategies that prevent the VEGF-A-mediated release of VWF may reduce tumor-associated hypercoagulation and metastasis in patients with bladder cancer. IMPLICATIONS: We identified the VEGF-A-mediated release of VWF from endothelial cells to be associated with bladder cancer progression.

Resistance Mechanisms to Anti-angiogenic Therapies in Cancer

Tumor growth and metastasis rely on tumor vascular network for the adequate supply of oxygen and nutrients. Tumor angiogenesis relies on a highly complex program of growth factor signaling, endothelial cell (EC) proliferation, extracellular matrix (ECM) remodeling, and stromal cell interactions. Numerous pro-angiogenic drivers have been identified, the most important of which is the vascular endothelial growth factor (VEGF). The importance of pro-angiogenic inducers in tumor growth, invasion and extravasation make them an excellent therapeutic target in several types of cancers. Hence, the number of anti-angiogenic agents developed for cancer treatment has risen over the past decade, with at least eighty drugs being investigated in preclinical studies and phase I-III clinical trials. To date, the most common approaches to the inhibition of the VEGF axis include the blockade of VEGF receptors (VEGFRs) or ligands by neutralizing antibodies, as well as the inhibition of receptor tyrosine kinase (RTK) enzymes. Despite promising preclinical results, anti-angiogenic monotherapies led only to mild clinical benefits. The minimal benefits could be secondary to primary or acquired resistance, through the activation of alternative mechanisms that sustain tumor vascularization and growth. Mechanisms of resistance are categorized into VEGF-dependent alterations, non-VEGF pathways and stromal cell interactions. Thus, complementary approaches such as the combination of these inhibitors with agents targeting alternative mechanisms of blood vessel formation are urgently needed. This review provides an updated overview on the pathophysiology of angiogenesis during tumor growth. It also sheds light on the different pro-angiogenic and anti-angiogenic agents that have been developed to date. Finally, it highlights the preclinical evidence for mechanisms of angiogenic resistance and suggests novel therapeutic approaches that might be exploited with the ultimate aim of overcoming resistance and improving clinical outcomes for patients with cancer.

Nanomaterials for Angiogenesis in Skin Tissue Engineering

Damage to skin tissue, which causes the disorder of the patient's body homeostasis, threatens the patient's life and increases the personal and social treatment burden. Angiogenesis, a key step in the wound healing process, provides sufficient oxygen and nutrients to the wound area. However, traditional clinical interventions are not enough to stabilize the formation of the vascular system to support wound healing. Due to the unique properties and multiple functions of nanomaterials, it has made a major breakthrough in the application of medicine. Nanomaterials provide a more effective treatment to hasten the angiogenesis and wound healing, by stimulating fundamental factors in the vascular regeneration phase. In the present review article, the basic stages and molecular mechanisms of angiogenesis are analyzed, and the types, applications, and prospects of nanomaterials used in angiogenesis are detailed. Impact statement Wound healing (especially chronic wounds) is currently a clinically important issue. The long-term nonhealing of chronic wounds often plagues patients, medical systems, and causes huge losses to the social economy. There is currently no effective method of treating chronic wounds in the clinic. Angiogenesis is an important step in wound healing. Nanomaterials had properties that are not found in conventional materials, and they have been extensively studied in angiogenesis. This review article provides readers with the molecular mechanisms of angiogenesis and the types and applications of angiogenic nanomaterials, hoping to bring inspiration to overcome chronic wounds.

A multi-scale model for determining the effects of pathophysiology and metabolic disorders on tumor growth

The search for efficient chemotherapy drugs and other anti-cancer treatments would benefit from a deeper understanding of the tumor microenvironment (TME) and its role in tumor progression. Because in vivo experimental methods are unable to isolate or control individual factors of the TME and in vitro models often do not include all the contributing factors, some questions are best addressed with systems biology mathematical models. In this work, we present a new fully-coupled, agent-based, multi-scale mathematical model of tumor growth, angiogenesis and metabolism that includes important aspects of the TME spanning subcellular-, cellular- and tissue-level scales. The mathematical model is computationally implemented for a three-dimensional TME, and a double hybrid continuous-discrete (DHCD) method is applied to solve the governing equations. The model recapitulates the distinct morphological and metabolic stages of a solid tumor, starting with an avascular tumor and progressing through angiogenesis and vascularized tumor growth. To examine the robustness of the model, we simulated normal and abnormal blood conditions, including hyperglycemia/hypoglycemia, hyperoxemia/hypoxemia, and hypercarbia/hypocarbia - conditions common in cancer patients. The results demonstrate that tumor progression is accelerated by hyperoxemia, hyperglycemia and hypercarbia but inhibited by hypoxemia and hypoglycemia; hypocarbia had no appreciable effect. Because of the importance of interstitial fluid flow in tumor physiology, we also examined the effects of hypo- or hypertension, and the impact of decreased hydraulic conductivity common in desmoplastic tumors. The simulations show that chemotherapy-increased blood pressure, or reduction of interstitial hydraulic conductivity increase tumor growth rate and contribute to tumor malignancy.

Crosstalk among colon cancer-derived exosomes, fibroblast-derived exosomes, and macrophage phenotypes in colon cancer metastasis

Cellular crosstalk is an important mechanism in the pathogenesis of inflammatory disorders and cancers. One significant means by which cells communicate with each other is through the release of exosomes. Exosomes are extracellular vesicles formed by the outward budding of plasma membranes, which are then released from cells into the extracellular space. Many studies have suggested that microvesicles released by colon cancer cells initiate crosstalk and modulate the fibroblast activities and macrophage phenotypes. Interestingly, crosstalk among colon cancer cells, macrophages and cancer-associated fibroblasts maximizes the mechanical composition of the stromal extracellular matrix (ECM). Exosomes contribute to cancer cell migration and invasion, which are critical for colon cancer progression to metastasis. The majority of the studies on colorectal cancers (CRCs) have focused on developing exosomal biomarkers for the early detection and prediction of CRC prognosis. This study highlights the crosstalk among colon cancer-derived exosomes, macrophage phenotypes and fibroblasts during colon cancer metastasis.

MiR-203a-3p inhibits retinal angiogenesis and alleviates proliferative diabetic retinopathy in oxygen-induced retinopathy (OIR) rat model via targeting VEGFA and HIF-1α

Proliferative diabetic retinopathy (PDR) is a common complication of diabetes mellitus, characterized by abnormal retinal angiogenesis. MicroRNA-203-3p (miR-203-3p) was found to be down-regulated in a murine model of proliferative retinopathy. This study was performed to explore the role of miR-203a-3p in retinal angiogenesis of PDR. Firstly, a rat OIR model, which was used to mimic PDR, was established and the OIR rats were treated with scrambled control or miR-203a-3p agomir by intravitreal injection. The results showed that the level of miR-203a-3p was decreased in OIR rats, and forced over-expression of miR-203a-3p inhibited OIR-induced retinal angiogenesis as evidenced by reduced blood vessel profiles and CD31 expression. OIR-induced up-regulation of VEGFA, HIF-α, PCNA, and MMPs in the retina was also counteracted by miR-203a-3p. Additionally, high glucose (HG)-induced proliferation, migration and tube formation of human retinal microvascular endothelial cells (HRMECs) were also dampened by the up-regulation of miR-203a-3p. Dual-luciferase reporter assay showed that miR-203a-3p could specifically bind to the 3'UTR of VEGFA and HIF-1α. Over-expression of VEGFA or HIF-1α restored the tube formation activity of HRMECs suppressed by miR-203a-3p. In conclusion, our findings demonstrate that up-regulation of miR-203a-3p might inhibit pathological retinal angiogenesis of PDR by targeting VEGFA and HIF-1α.

Flipping the Molecular Switch: Influence of Perlecan and Its Modifiers in the Tumor Microenvironment

The tumor microenvironment (TME) is rich in matrix components, growth factors, cytokines, and enzymatic modifiers that respond to changing conditions, to alter the fundamental properties of the tumor bed. Perlecan/HSPG2, a large, multi-domain heparan sulfate proteoglycan, is concentrated in the reactive stroma that surrounds tumors. Depending on its state in the TME, perlecan can either prevent or promote the progression of cancers to metastatic disease. Breast, prostate, lung, and renal cancers all preferentially metastasize to bone, a dense, perlecan-rich environment that is initially a "hostile" niche for cancer cells. Driven by inflammation, production of perlecan and its enzyme modifiers, which include matrix metalloproteinases (MMPs), sulfatases (SULFs), and heparanase (HPSE), increases in the reactive stroma surrounding growing and invading tumors. MMPs act upon the perlecan core protein, releasing bioactive fragments of the protein, primarily from C-terminal domains IV and V. These fragments influence cell adhesion, invasion, and angiogenesis. Sulfatases and heparanases act directly upon the heparan sulfate chains, releasing growth factors from reservoirs to reach receptors on the cancer cell surface. We propose that perlecan modifiers, by promoting the degradation of the perlecan-rich stroma, "flip the molecular switch" and convert the "hostile" stroma into a welcoming one that supports cancer dissemination and metastasis. Targeted therapies that prevent this molecular conversion of the TME should be considered as potential new therapeutics to limit metastasis.

A tropomyosin-like Meretrix meretrix Linnaeus polypeptide inhibits the proliferation and metastasis of glioma cells via microtubule polymerization and FAK/Akt/MMPs signaling

Glioblastoma (GBM) represents the most common, aggressive and deadliest primary tumors with poor prognosis as available therapeutic approaches fail to control its aberrant proliferation and high invasiveness. Thus, the therapeutic agents targeting these two characteristics will be more effective. In present study, a novel polypeptide (MM15), which was originally purified from Meretrix meretrix Linnaeus and has been proven to possess potent antitumor activity by our laboratory, was recombinant expressed and identified as a tropomyosin homologous protein. The recombinant polypeptide (re-MM15) could induce the U87 cell cycle arrest in G2/M phase and cell apoptosis by inducing tubulin polymerization. Additionally, re-MM15 displayed the significant inhibition to the migration and invasion of U87 cells through downregulating FAK/Akt/MMPs signaling. Furthermore, the in vivo analysis suggested that re-MM15 significantly blocked tumor growth in U87 xenograft model. Collectively, our results indicated that re-MM15, with anti-GBM properties in vitro and in vivo, has promising potential as a new anticancer candidate for GBM.

Extracellular Matrix Composition and Remodeling: Current Perspectives on Secondary Palate Formation, Cleft Lip/Palate, and Palatal Reconstruction

Craniofacial development comprises a complex process in humans in which failures or disturbances frequently lead to congenital anomalies. Cleft lip with/without palate (CL/P) is a common congenital anomaly that occurs due to variations in craniofacial development genes, and may occur as part of a syndrome, or more commonly in isolated forms (non-syndromic). The etiology of CL/P is multifactorial with genes, environmental factors, and their potential interactions contributing to the condition. Rehabilitation of CL/P patients requires a multidisciplinary team to perform the multiple surgical, dental, and psychological interventions required throughout the patient's life. Despite progress, lip/palatal reconstruction is still a major treatment challenge. Genetic mutations and polymorphisms in several genes, including extracellular matrix (ECM) genes, soluble factors, and enzymes responsible for ECM remodeling (e.g., metalloproteinases), have been suggested to play a role in the etiology of CL/P; hence, these may be considered likely targets for the development of new preventive and/or therapeutic strategies. In this context, investigations are being conducted on new therapeutic approaches based on tissue bioengineering, associating stem cells with biomaterials, signaling molecules, and innovative technologies. In this review, we discuss the role of genes involved in ECM composition and remodeling during secondary palate formation and pathogenesis and genetic etiology of CL/P. We also discuss potential therapeutic approaches using bioactive molecules and principles of tissue bioengineering for state-of-the-art CL/P repair and palatal reconstruction.

COL1A2 is a TBX3 target that mediates its impact on fibrosarcoma and chondrosarcoma cell migration

The developmentally important T-box transcription factor TBX3, is overexpressed in several cancers and contributes to tumorigenesis as either a tumour promoter or tumour suppressor. For example, TBX3 promotes cell proliferation, migration and invasion of chondrosarcoma cells but inhibits these processes in fibrosarcoma cells. This suggests that the cellular context influences TBX3 oncogenic functions, but the mechanism(s) involved has not been elucidated. COL1A2 encodes type I collagen and, like TBX3, plays important roles during embryogenesis and can act as either oncogene or tumour suppressor. Here we explore the possibility that COL1A2 may be a TBX3 target gene responsible for mediating its opposing oncogenic roles in chondrosarcoma and fibrosarcoma cells. Results from qRT-PCR, western blotting, luciferase reporter and chromatin immunoprecipitation assays show that TBX3 binds and activates the COL1A2 promoter. Furthermore, we show that TBX3 levels are regulated by AKT1 and that pseudo-phosphorylation of TBX3 at an AKT consensus serine site, enhances its ability to activate COL1A2. Importantly, we demonstrate that COL1A2 mediates the pro- and anti-migratory effects of TBX3 in chondrosarcoma and fibrosarcoma cells respectively. Our data reveal that the AKT1/TBX3/COL1A2 axis plays an important role in sarcomagenesis.

Mechanisms of Action of Novel Drugs Targeting Angiogenesis-Promoting Matrix Metalloproteinases

Angiogenesis is facilitated by the proteolytic activities of members of the matrix metalloproteinase (MMP) family. More specifically, MMP-9 and MT1-MMP directly regulate angiogenesis, while several studies indicate a role for MMP-2 as well. The correlation of MMP activity to tumor angiogenesis has instigated numerous drug development programs. However, broad-based and Zn²⁺-chelating MMP inhibitors have fared poorly in the clinic. Selective MMP inhibition by antibodies, biologicals, and small molecules has utilized unique modes of action, such as (a) binding to protease secondary binding sites (exosites), (b) allosterically blocking the protease active site, or (c) preventing proMMP activation. Clinical trials have been undertaken with several of these inhibitors, while others are in advanced pre-clinical stages. The mechanistically non-traditional MMP inhibitors offer treatment strategies for tumor angiogenesis that avoid the off-target toxicities and lack of specificity that plagued Zn²⁺-chelating inhibitors.

MicroRNA heterogeneity in melanoma progression

The altered expression of miRNAs has been linked with neocarcinogenesis or the development of human malignancies including melanoma. Of significance, multiple clinical studies have documented that distinct sets of microRNAs (miRNAs) could be utilized as prognostic biomarkers for cancer development or predict the outcomes of treatment responses. To that end, an in-depth validation of such differentially expressed miRNAs is necessary in diverse settings of cancer patients in order to devise novel approaches to control tumor growth and/or enhance the efficacy of clinically-relevant therapeutic options. Moreover, considering the heterogeneity and sophisticated regulation of miRNAs, the precise delineation of their cellular targets could also be explored to design personalized medicine. Given the significance of miRNAs in regulating several key cellular processes of tumor cells including cell cycle progression and apoptosis, we review the findings of such miRNAs implicated in melanoma tumorigenesis. Understanding the novel mechanistic insights of such miRNAs will be useful for developing diagnostic or prognostic biomarkers or devising future therapeutic intervention for malignant melanoma.

Prognostic Value of MMP-9 -1562 C/T Gene Polymorphism in Patients With Sepsis

Introduction:

Matrix metalloproteinase-9 (MMP-9) plays an important role in the pathophysiology of sepsis. A single-nucleotide polymorphism (SNP) at position -1562 (C/T) in the MMP-9 gene has been associated with differential MMP-9 expression, being higher when the -1562 T allele is present. We evaluated the association of the SNP MMP9 -1562 C/T with severity and mortality in patients with sepsis to establish whether the prognosis of the disease is affected.

Materials and Methods:

A case-control study exploratory was carried out in a cohort of infected patients. 540 individuals were selected in total, 270 patients with sepsis and 270 controls (infected but non-septic), classified according to the 2016 consensus (Sepsis-3). The presence of the single-nucleotide polymorphism (SNP; allele T and/or allele C) was determined through analyses of restriction fragment length polymorphism and plasma levels of MMP-9 were determined through enzyme-linked immunosorbent assay immunoassay.

Results:

SNP MMP-9 -1562 has two known alleles (T and C), with predominance of the C over the T allele; in the group of patients with sepsis, T allele was found in 7.2% of cases, while C allele in the rest (92.8%); in comparison, in the group of infected but non-septic patients, frequencies were 9.4% for T allele and 90.6% for the C allele (P = .33). Also, the presence of the polymorphic T allele was not related to the levels of MMP-9 in patients with sepsis in comparison with infected but non-septic patients 780 (397-1375) ng/mL vs 646 (172-1249) ng/mL (P = .64). There was also no association between the SNP and sepsis mortality (P = .78).

Conclusions:

We concluded that there was no association between the SNP MMP9 -1562 C/T and sepsis or between the SNP MMP9 -1562 C/T and sepsis mortality in the Northeastern Colombian septic patient cohort. Further research is needed to clarify the correlation among sepsis, genetic factors with allele T and MMP-9 plasma concentration.

miR-134 inhibits osteosarcoma cell invasion and metastasis through targeting MMP1 and MMP3 in vitro and in vivo

miR-134 has been shown to be associated with angiogenesis and the progression of osteosarcoma. This study further assessed the effects of miR-134 expression on osteosarcoma cell migration, invasion, and metastasis in vitro and in a nude mouse xenograft model, exploring the underlying molecular events. Luciferase reporter assays revealed that miR-134 directly targets the 3'-UTRs of MMP1 and MMP3 to reduce their expression in osteosarcoma cells. In conclusion, overexpression of miR-134 suppresses osteosarcoma cell invasion and metastasis through the inhibition of MMP1 and MMP3 expression. We propose miR-134 as an attractive novel therapeutic target for the treatment of osteosarcoma.

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

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

Clinical Significance of Matrix Metalloproteinases in Blood Plasma of Patients with Gastric Cancer

Plasma levels of MMP-2, MMP-7, and MMP-9 and their tissue inhibitor TIMP-2 were measured in 89 patients with gastric cancer and the relationship between these parameters and the main clinical morphological characteristics of the disease was analyzed. Plasma levels of the proteins were measured using standard direct ELISA kits. The level of MMP-7 in patients with gastric cancer was significantly higher than in the control group (medians 2.7 and 1.2 ng/ml, respectively; p<0.01), but only in 51% patients this parameter surpassed the upper threshold normal value (2.35 ng/ml; 95% percentile of control). The level of MMP-9 in gastric cancer patients was lower than in control group by 1.6 times (medians 167 and 267 ng/ml, respectively; p<0.01). Plasma levels of MMP-2 and TIMP-2 in patients with gastric cancer and healthy subjects were similar. No appreciable associations of plasma matrixins and TIMP-2 with the main clinical morphological characteristics of the disease were detected. The patients were followed up for 8 to 85 months (median 70.8 months). Low level of MMP-2 and high level of MMP-7 in the plasma proved to be unfavorable prognostic factors for overall survival. At MMP-2<268 ng/ml, the 5-year overall survival was 32% vs. 60% for patients with the marker level higher than this threshold value (p=0.016). The differences in overall survival in relation to their MMP-7 levels for 5-year observation did not surpass 16% (39% at marker level >2.7 ng/ml and 55% at lower level; p=0.048). Plasma levels of MMP-2 and TIMP-2 were not significantly associated with overall survival. Multivariate analysis showed that only T index (p=0.034) and plasma MMP-7 level (p=0.007) were essential for overall survival. The increase in plasma or serum MMP-7 levels is a universal phenomenon in tumors of different histogenesis, which precluded the use of this parameter as a specific diagnostic marker of gastric cancer. At the same time, it could be useful for monitoring the treatment efficiency and detection of relapses. In addition, high plasma level of MMP-7 remained an independent factor of unfavorable prognosis for overall survival of patients with gastric cancer.

MMP-9 inhibition promotes anti-tumor immunity through disruption of biochemical and physical barriers to T-cell trafficking to tumors

Matrix metalloproteinase-9 (MMP-9), whose expression is frequently dysregulated in cancer, promotes tumor growth, invasion, and metastasis by multiple mechanisms, including extracellular matrix remodeling and growth-factor and cytokine activation. We developed a monoclonal antibody against murine MMP-9, which we found decreased growth of established primary tumors in an orthotopic model of HER2-driven breast cancer (HC11-NeuT) in immunocompetent mice. RNA sequencing (RNAseq) profiling of NeuT tumors and additional mouse model tumors revealed that anti-MMP-9 treatment resulted in upregulation of immune signature pathways associated with cytotoxic T-cell response. As there is a need to boost the low response rates observed with anti-PDL1 antibody treatment in the clinical setting, we assessed the potential of anti-MMP-9 to improve T-cell response to immune checkpoint inhibitor anti-PDL1 in NeuT tumors. Anti-MMP-9 and anti-PDL1 cotreatment reduced T-cell receptor (TCR) clonality and increased TCR diversity, as detected by TCR sequencing of NeuT tumors. Flow cytometry analyses of tumors showed that the combination treatment increased the frequency of CD3+ T cells, including memory/effector CD4 and CD8 T cells, but not regulatory T cells, among tumor-infiltrating leukocytes. Moreover, in vitro enzymatic assays corroborated that MMP-9 cleaves key T-cell chemoattractant CXC receptor 3 ligands (CXC ligand [CXCL] 9, CXCL10, and CXCL11) and renders them inactive in T-cell migration assays. Consistent with our in vitro experiments, analysis of NeuT tumor protein lysates showed that anti-MMP-9 treatment increases expression of CXCL10 and other T cell–stimulating factors, such as interleukin (IL)-12p70 and IL-18. We show that inhibition of MMP-9, a key component of the tumor-promoting and immune-suppressive myeloid inflammatory milieu, increases T-helper cell 1 type cytokines, trafficking of effector/memory T cells into tumors, and intratumoral T-cell diversity.

Macrophages enhance Vegfa-driven angiogenesis in an embryonic zebrafish tumour xenograft model

Tumour angiogenesis has long been a focus of anti-cancer therapy; however, anti-angiogenic cancer treatment strategies have had limited clinical success. Tumour-associated myeloid cells are believed to play a role in the resistance of cancer towards anti-angiogenesis therapy, but the mechanisms by which they do this are unclear. An embryonic zebrafish xenograft model has been developed to investigate the mechanisms of tumour angiogenesis and as an assay to screen anti-angiogenic compounds. In this study, we used cell ablation techniques to remove either macrophages or neutrophils and assessed their contribution towards zebrafish xenograft angiogenesis by quantitating levels of graft vascularisation. The ablation of macrophages, but not neutrophils, caused a strong reduction in tumour xenograft vascularisation and time-lapse imaging demonstrated that tumour xenograft macrophages directly associated with the migrating tip of developing tumour blood vessels. Finally, we found that, although macrophages are required for vascularisation in xenografts that either secrete VEGFA or overexpress zebrafish vegfaa, they are not required for the vascularisation of grafts with low levels of VEGFA, suggesting that zebrafish macrophages can enhance Vegfa-driven tumour angiogenesis. The importance of macrophages to this angiogenic response suggests that this model could be used to further investigate the interplay between myeloid cells and tumour vascularisation.

Summary: Zebrafish embryonic macrophages associate with the distal tips of tumour xenograft blood vessels and are required for Vegfa-driven angiogenesis.

Exenatide modulates expression of metalloproteinases and their tissue inhibitors in TNF-α stimulated human retinal pigment epithelial cells

BACKGROUND

Diabetic retinopathy (DR) is one of the most common complications of diabetes and the leading cause of acquired blindness in adults. In diabetic patients hyperglycemia induces complex metabolic abnormalities affecting retinal homeostasis, and promotes retinal inflammation and angiogenesis. Incretin mimetic drugs such exenatide, are a relatively new group of drugs used in the treatment of diabetes. We investigated the potential direct effects of exenatide on human retinal pigment epithelium (HRPE).

METHODS

cAMP production was measured after stimulation of HRPE cells with GLP-1 and exenatide. Intracellular signaling pathways were also examined. HRPE cells were stimulated with TNF-α and subsequently incubated with exenatide. The concentration of metalloproteinases, MMP-1, MMP-2 and MMP-9, and tissue inhibitors of metalloproteinases, TIMP-1, TIMP-2, and TIMP-3 were evaluated. Viability, cytotoxicity and caspase 3/7 activation were determined. Activity of dipeptidyl peptidase-4 (DPP-4), an enzyme involved in GLP-1 inactivation, was also determined.

RESULTS

Both GLP-1 and exenatide stimulation in HRPE cells caused no effect in cAMP levels suggesting alternative signaling pathways. Signaling pathway analysis showed that exenatide reduced phosphorylation of Akt-Ser473, PRAS40, SAPK/JNK, Bad, and S6 proteins but not Akt-Thr308. Exenatide also decreased MMP-1, MMP-9, and TIMP-2 protein levels whereas MMP-2 level in HRPE cells was increased. Finally, we show that exenatide decreased the activity of DPP-4 in TNF-α stimulated HRPE cells.

CONCLUSIONS

These findings indicate that exenatide modulates regulation of extracellular matrix components involved in retinal remodeling.