Interferon-gamma regulation of TNFalpha-induced matrix metalloproteinase 3 expression and migration of human glioma T98G cells

The Crosstalk between the EGFR and IFN-γ Pathways and Synergistic Roles in Survival Prediction and Immune Escape in Gliomas

Glioma is the most common primary malignant brain tumor. The poor prognosis of gliomas, especially glioblastoma (GBM), is associated with their unique molecular landscape and tumor microenvironment (TME) features. The epidermal growth factor receptor (EGFR) gene is one of the frequently altered loci in gliomas, leading to the activation of the EGFR signaling pathway and thus, promoting the genesis of gliomas. Whether there exist factors within the TME that can lead to EGFR activation in the context of gliomas is currently unexplored. In total, 702 samples from The Cancer Genome Atlas (TCGA) and 325 samples from The Chinese Glioma Genome Atlas (CGGA) were enrolled in this study. Gene signatures related to EGFR signaling and interferon-γ (IFN-γ) response were established via the LASSO-COX algorithm. Gene Set Enrichment Analysis (GSEA) and Gene Ontology (GO) analysis were applied for function exploration. Kaplan-Meier (KM) curves and single sample GSEA (ssGSEA) of immune cell subpopulations were performed to analyze the prognosis and TME characteristics of different subgroups. Moreover, Western blotting (WB) and flow cytometry (FCM) demonstrated the correlation between IFN-γ and EGFR signaling activation and the subsequent induction of programmed death ligand 1 (PD-L1) expression. An EGFR signaling-related risk score was established, and a higher score was correlated with poorer prognosis and a more malignant phenotype in gliomas. Biological function analysis revealed that a higher EGFR-related score was significantly associated with various cytokine response pathways, especially IFN-γ. Long-term (7 days) exposure to IFN-γ (400 ng/mL) induced the activation of EGFR signaling in the u87 cell line. Next, an IFN-γ response-related risk score was established; the combination of these two scores could be used to further reclassify gliomas into subtypes with different clinical features and TME features. Double high-risk samples tended to have a poorer prognosis and more immunosuppressive TME. Additionally, FCM discovered that the activation of EGFR signaling via EGF (100 ng/mL) could trigger PD-L1 protein expression. This research indicates that IFN-γ, an inflammatory cytokine, can activate the EGFR pathway. The combination of EGFR signaling and IFN-γ response pathway can establish a more precise classification of gliomas.

Coriolus versicolor and its bioactive molecule are potential immunomodulators against cancer cell metastasis via inactivation of MAPK pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Coriolus versicolor (CV) has been used in traditional Chinese medicine for over 2000 years as a premium medicine for enhancing good health and longevity. The immunomodulatory and anti-cancer effects of polysaccharopeptides (PSP) from cultured CV have been extensively studied; however, the effect and the mechanism of action of other small molecules from CV remain unknown.

AIM OF THE STUDY

we aim to examine the immunomodulatory and anti-cancer effects of the small molecules from CV (SMCV) and identify the active compounds that are responsible for the biological effects against glioblastoma multiforme cells.

MATERIALS AND METHODS

The effects of SMCV/active compound on cytokine and MMP mRNA expressions and productions were assessed by quantitative reverse transcription polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. An active compound from SMCV was identified with a bioassay-guided fractionation scheme. The potential mode of action of the active compound was further investigated by identifying the cell signaling pathway. The protein expressions of phospho-ERK, phospho-JNK and phospho-p38 MAPKs were measured by Western Blotting. The anti-invasive effect of SMCV/bioactive compound against T98G, lung carcinoma (A549), and breast adenocarcinoma (MDA-MB-231) cells were determined using invasion assay.

RESULTS

Our results showed that SMCV had strong immunomodulatory effect by suppressing LPS-induced TNF-α production, whereas increasing poly I:C-induced IFN-β level in PBMac. SMCV not only possessed indirect anti-cancer effect by suppressing TNF-α-induced MMP-3 production in glioblastoma T98G cells, but also directly reduced the invasion ability of malignant cells including T98G, A549 and MDA-MB-231. Using bioassay-guided fractionation scheme, we isolated 9-KODE methyl ester (compound AM) that was responsible for the bioactivity of SMCV. This compound suppressed TNF-α-induced MMP-3 production in T98G cells and the suppression may be correlated with the inactivation of p38 mitogen-activated protein kinase (MAPK) pathway. Moreover, compound AM also directly reduced T98G cell invasion.

CONCLUSION

Results of our present study provides scientific evidence that SMCV possesses immunomodulatory and anti-cancer effects. Its bioactive compound, compound AM, is a potential new drug candidate against the invasion and metastasis of glioblastoma cells.

The immunomodulatory role of matrix metalloproteinases in colitis-associated cancer

Matrix metalloproteinases (MMPs) are an important class of enzymes in the body that function through the extracellular matrix (ECM). They are involved in diverse pathophysiological processes, such as tumor invasion and metastasis, cardiovascular diseases, arthritis, periodontal disease, osteogenesis imperfecta, and diseases of the central nervous system. MMPs participate in the occurrence and development of numerous cancers and are closely related to immunity. In the present study, we review the immunomodulatory role of MMPs in colitis-associated cancer (CAC) and discuss relevant clinical applications. We analyze more than 300 pharmacological studies retrieved from PubMed and the Web of Science, related to MMPs, cancer, colitis, CAC, and immunomodulation. Key MMPs that interfere with pathological processes in CAC such as MMP-2, MMP-3, MMP-7, MMP-9, MMP-10, MMP-12, and MMP-13, as well as their corresponding mechanisms are elaborated. MMPs are involved in cell proliferation, cell differentiation, angiogenesis, ECM remodeling, and the inflammatory response in CAC. They also affect the immune system by modulating differentiation and immune activity of immune cells, recruitment of macrophages, and recruitment of neutrophils. Herein we describe the immunomodulatory role of MMPs in CAC to facilitate treatment of this special type of colon cancer, which is preceded by detectable inflammatory bowel disease in clinical populations.

TNF-α mediated MEK-ERK signaling in invasion with putative network involving NF-κB and STAT-6: a new perspective in glioma

Glioblastoma is the most common malignant primary brain tumor with poor prognosis. Invasion involves pro-inflammatory cytokines and major signaling hubs. Tumor necrosis factor-α (TNF-α) acts as a master switch in establishing an intricate link between inflammation and cancer. The present study attempted to explore the possible implication of MAPK extracellular signaling-regulated kinase kinase (MEK)-extracellular signaling-regulated kinase (ERK) signaling pathway and expression of nuclear factor-κB (NF-κB), signal transducers and activators of transcription-6 (STAT-6), ERK, and phosphorylated-ERK (p-ERK) signaling proteins in TNF-α microenvironment. U0126 and PD98059 were used to inhibit the MEK-ERK1/2 pathway. TNF-α stimulation enhanced invasion in U87MG, U251MG and patient-derived primary glioma cells, whereas cell viability was not altered. Matrix metalloproteinase-2 (MMP-2) activity was increased only in U251MG glioma cells. These data suggest that TNF-α microenvironment plays an important role in the invasion of U251MG, U87MG, and patient-derived primary glioma cells, without any cytotoxic effect. The MMP-2 activity is differentially regulated by TNF-α stimulation in these cells. TNF-α stimulation upregulated the protein expression of ERK-1, ERK-2 and also increased the level of p-ERK1/2. TNF-α stimulation further upregulated the expression of NF-κB1, STAT-6 in tandem with Ras-MEK signaling system in U87MG cells, which emphasized the possible involvement of these signaling hubs in the glioma microenvironment. MEK-ERK inhibitors significantly attenuated the invasion of U87MG cells mediated by the TNF-α stimulation, probably through their inhibitory impact on p-ERK1/2 and ERK-2. This study provides the possible rationale of invasion by glioma cells in a TNF-α-induced pro-inflammatory milieu, which involves direct role of MEK-ERK signaling, with possible implication of NF-κB and STAT-6.

Interferon γ suppresses dentin sialophosphoprotein in oral squamous cell carcinoma cells resulting in antitumor effects, via modulation of the endoplasmic reticulum response

The expression of proinflammatory cytokines in various malignant neoplasms is widely considered to represent the host immune response to tumor development. The role of interferon (IFN)γ in head and neck squamous cell carcinoma, and its association with endoplasmic reticulum (ER) stress pathways, remains a subject of ongoing investigation. Dentin sialophosphoprotein (DSPP), which is a member of the small integrin-binding N-linked glycoproteins family, has been implicated in malignant transformation and invasion of oral squamous cell carcinoma (OSCC). Recent studies have established matrix metalloproteinase (MMP)20 as the cognate MMP partner of DSPP. The present study examined the effects of IFNγ treatment on DSPP and MMP20 expression, ER stress, the unfolded protein response (UPR), and calcium (Ca) homeostasis regulatory mechanisms in OSCC cells. The OSC2 OSCC cell line was treated with IFNγ at specific time-points. At each time-point, the mRNA expression levels of DSPP and MMP20, and those of ER-stress-, UPR- and Ca homeostasis-associated proteins [78-kDa glucose-regulated protein (GRP78), sarco/endoplasmic reticulum Ca²⁺-ATPase (SERCA2b), inositol 1,4,5-trisphosphate receptor (IP3r), protein kinase R-like ER kinase (PERK) and inositol-requiring enzyme 1 (IRE1)], were assessed by reverse transcription-quantitative polymerase chain reaction. The protein expression levels of B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), proliferating cell nuclear antigen (PCNA) and cytochrome c were analyzed by western blotting. Cell viability, apoptosis and migration were evaluated by MTT, Annexin V-fluorescein isothiocyanate flow cytometry and wound-healing assays, respectively. IFNγ treatment significantly downregulated the mRNA expression levels of the major ER stress regulator GRP78 and, to a lesser extent, the UPR-associated molecule IRE1; however, IFNγ had no significant effect on PERK. With regards to ER Ca homeostasis molecules, treatment with IFNγ downregulated the mRNA expression levels of SERCA2b and upregulated those of IP3r. Furthermore, DSPP and MMP20 mRNA expression levels were significantly reduced following IFNγ treatment. Notably, treatment with IFNγ hampered OSC2 migration, reduced cell viability and PCNA protein expression, enhanced apoptosis, downregulated Bcl-2, and upregulated Bax and cytochrome c. Overall, IFNγ inhibited OSCC cell viability and migration, and increased apoptosis, possibly by regulating ER stress and UPR mechanisms. In addition, IFNγ-induced DSPP and MMP20 downregulation may correspond with alteration in ER Ca homeostasis.

A mouse model of the Δ133p53 isoform: roles in cancer progression and inflammation

This review paper outlines studies on the Δ122p53 mouse, a model of the human Δ133p53 isoform, together with studies in other model organisms, cell culture, and where available, clinical investigations. In general, these studies imply that, in contrast to the canonical p53 tumor suppressor, Δ133p53 family members have oncogenic capability. Δ122p53 is multi-functional, conferring survival and proliferative advantages on cells, promoting invasion, metastasis and vascularization, as does Δ133p53. Cancers with high levels of Δ133p53 often have poor prognosis. Δ122p53 mediates its effects through the JAK-STAT and RhoA-ROCK signaling pathways. We propose that Δ133p53 isoforms have evolved as inflammatory signaling molecules to deal with the consequent tissue damage of p53 activation. However, if sustained expression of the isoforms occur, pathologies may result.

Anti-Inflammatory Effects of Resveratrol: Mechanistic Insights

Inflammation is the principal response invoked by the body to address injuries. Despite inflammation constituting a crucial component of tissue repair, it is well known that unchecked or chronic inflammation becomes deleterious, leading to progressive tissue damage. Studies over the past years focused on foods rich in polyphenols with anti-inflammatory and immunomodulatory properties, since inflammation was recognized to play a central role in several diseases. In this review, we discuss the beneficial effects of resveratrol, the most widely investigated polyphenol, on cancer and neurodegenerative, respiratory, metabolic, and cardiovascular diseases. We highlight how resveratrol, despite its unfavorable pharmacokinetics, can modulate the inflammatory pathways underlying those diseases, and we identify future opportunities for the evaluation of its clinical feasibility.

IKK phosphorylates RelB to modulate its promoter specificity and promote fibroblast migration downstream of TNF receptors

TNFα is a potent cytokine that plays a critical role in numerous cellular processes, particularly immune and inflammatory responses, programmed cell death, angiogenesis, and cell migration. Thus, understanding the molecular mechanisms that mediate TNFα-induced cellular responses is a crucial issue. It is generally accepted that global DNA binding activity of the NF-κB avian reticuloendotheliosis viral (v-rel) oncogene related B (RelB) subunit is not induced upon TNFα treatment in fibroblasts, despite its TNFα-induced nuclear accumulation. Here, we demonstrate that RelB plays a critical role in promoting fibroblast migration upon prolonged TNFα treatment. We identified the two kinases IκB kinase α (IKKα) and IκB kinase β (IKKβ) as RelB interacting partners whose activation by TNFα promotes RelB phosphorylation at serine 472. Once phosphorylated on serine 472, nuclear RelB dissociates from its interaction with the inhibitory protein IκBα and binds to the promoter of critical migration-associated genes, such as the matrix metallopeptidase 3 (MMP3). Further, we show that RelB serine 472 phosphorylation status controls MMP3 expression and promigration activity downstream of TNF receptors. Our findings provide new insights into the regulation of RelB activity and reveal a novel link between selective NF-κB target gene expression and cellular response in response to TNFα.

A novel NF-κB/MMP-3 signal pathway involves in the aggressivity of glioma promoted by Bmi-1

Matrix metalloproteinase 3 (MMP-3) is implicated in the pathogenesis and progression of glioma. However, whether MMP-3 participates in the regulation of metastasis and its mechanisms in glioma is mostly unknown. In the present study, glioma cells were stably transfected with Bmi-1 small interfering RNA (siRNA) to knockdown off Bmi-1 or were transiently transfected with Bmi-1 complementary DNA (cDNA) to upregulate the Bmi-1 level and to evaluate their effects on invasion and expression analysis for molecules involved in invasion. Knockdown of Bmi-1 dramatically reduced a nuclear factor kappa B (NF-κB) and MMP-3 expression and activity in T98G cells. When the T98G cells were upregulated in the Bmi-1 levels, the T98G cells were treated with 10 μM BAY 11-7028 to inhibit the NF-κB activity. The invasion induced by upregulation of Bmi-1 was severely abolished by BAY 11-7028 in Bmi-1 overexpression cells. The T98G cell metastatic potential was increased by overexpression of Bmi-1; completely at the same time, the NF-κB activity and MMP-3 expression was also increased. Taken together, these findings suggest that Bmi-1 promotes glioma cell migration and invasion via NF-κB-mediated upregulation of MMP-3.

Identification of non-canonical NF-κB signaling as a critical mediator of Smac mimetic-stimulated migration and invasion of glioblastoma cells

As inhibitor of apoptosis (IAP) proteins can regulate additional signaling pathways beyond apoptosis, we investigated the effect of the second mitochondrial activator of caspases (Smac) mimetic BV6, which antagonizes IAP proteins, on non-apoptotic functions in glioblastoma (GBM). Here, we identify non-canonical nuclear factor-κB (NF-κB) signaling and a tumor necrosis factor-α (TNFα)/TNF receptor 1 (TNFR1) autocrine/paracrine loop as critical mediators of BV6-stimulated migration and invasion of GBM cells. In addition to GBM cell lines, BV6 triggers cell elongation, migration and invasion in primary, patient-derived GBM cells at non-toxic concentrations, which do not affect cell viability or proliferation, and also increases infiltrative tumor growth in vivo underscoring the relevance of these findings. Molecular studies reveal that BV6 causes rapid degradation of cellular IAP proteins, accumulation of NIK, processing of p100 to p52, translocation of p52 into the nucleus, increased NF-κB DNA binding and enhanced NF-κB transcriptional activity. Electrophoretic mobility shift assay supershift shows that the NF-κB DNA-binding subunits consist of p50, p52 and RelB further confirming the activation of the non-canonical NF-κB pathway. BV6-stimulated NF-κB activation leads to elevated mRNA levels of TNFα and additional NF-κB target genes involved in migration (i.e., interleukin 8, monocyte chemoattractant protein 1, CXC chemokine receptor 4) and invasion (i.e., matrix metalloproteinase-9). Importantly, inhibition of NF-κB by overexpression of dominant-negative IκBα superrepressor prevents the BV6-stimulated cell elongation, migration and invasion. Similarly, specific inhibition of non-canonical NF-κB signaling by RNA interference-mediated silencing of NIK suppresses the BV6-induced cell elongation, migration and invasion as well as upregulation of NF-κB target genes. Intriguingly, pharmacological or genetic inhibition of the BV6-stimulated TNFα autocrine/paracrine loop by the TNFα-blocking antibody Enbrel or by knockdown of TNFR1 abrogates BV6-induced cell elongation, migration and invasion. By demonstrating that the Smac mimetic BV6 at non-toxic concentrations promotes migration and invasion of GBM cells via non-canonical NF-κB signaling, our findings have important implications for the use of Smac mimetics as cancer therapeutics.

[Evaluation for antithrombotic agents by a thrombotic model in animals]

To investigate cerebral infarction and intracranial hemorrhage (ICH) in relation to antithrombotic agents, we established an animal stroke model induced by using a combination of a photosensitive dye and local green photoillumination. Microplasmin (μPli), a derivative of plasmin lacking the five "kringle" domains, was administered in this model, and its effect was studied using magnetic resonance imaging. μPli treatment reduced cerebral damage 24 h after middle cerebral artery occlusion; it also reduced the expansion of the positive area on perfusion-weighted images between 1 and 24 h and the degree of neurological deficits. Tissue-type plasminogen activator (t-PA), a serine proteinase that converts plasminogen to plasmin, has been approved for treating acute ischemic stroke, but delayed treatment is associated with increased risk of ICH. Plasmin participates in the degradation of fibrin, causing clot lysis, and of various extracellular matrix proteins, either directly or via the activation of matrix metalloproteinases (MMPs). In this study, we observed that MMP-3 is relatively important in the enhanced risk of ICH induced by delayed t-PA treatment for ischemic stroke. In particular, the binding of t-PA with low-density lipoprotein receptor-related protein (LRP) results in the release of MMP-3 by endothelial cells. LRP production is upregulated in endothelial cells exposed to ischemia, and elevated LRP levels have been implicated in the increased ICH risk associated with delayed t-PA treatment. This implies that the t-PA/LRP/MMP-3 pathway may be a suitable target for developing strategies to improve the therapeutic efficacy of t-PA in acute ischemic stroke.

A complete compilation of matrix metalloproteinase expression in human malignant gliomas

Glioblastomas are characterized by an aggressive local growth pattern, a marked degree of invasiveness and poor prognosis. Tumor invasiveness is facilitated by the increased activity of proteolytic enzymes which are involved in destruction of the extracellular matrix of the surrounding healthy brain tissue. Elevated levels of matrix metalloproteinases (MMPs) were found in glioblastoma (GBM) cell-lines, as well as in GBM biopsies as compared with low-grade astrocytoma (LGA) and normal brain samples, indicating a role in malignant progression. A careful review of the available literature revealed that both the expression and role of several of the 23 human MMP proteins is controversely discussed and for some there are no data available at all. We therefore screened a panel of 15 LGA and 15 GBM biopsy samples for those MMPs for which there is either no, very limited or even contradictory data available. Hence, this is the first complete compilation of the expression pattern of all 23 human MMPs in astrocytic tumors. This study will support a better understanding of the specific expression patterns and interaction of proteolytic enzymes in malignant human glioma and may provide additional starting points for targeted patient therapy.

Protein kinase D1 mediates synergistic MMP-3 expression induced by TNF-α and bradykinin in human colonic myofibroblasts

Stromal myofibroblasts regulate extracellular matrix components through the secretion of matrix metalloproteinases such as MMP-3. Both myofibroblasts and MMP-3 have been implicated in colonic inflammation and cancer but the regulatory signaling mechanism(s) are unknown. Exposure of the human colonic myofibroblast cell line 18Co to TNF-α and bradykinin induced synergistic MMP-3 mRNA and protein expression, which were blocked by the preferential PKC inhibitors GF109203X and Go6983 and by the MEK inhibitor U0126. Transfection with siRNA targeting PKD1, a known downstream target of both bradykinin and PKC, completely inhibited MMP-3 mRNA and protein expression. Our results imply that TNF-α and bradykinin amplify MMP-3 expression at a transcriptional level through a signaling cascade involving PKC, PKD1, and MEK. PKD1 plays a critical role in the expression of MMP-3 in human colonic myofibroblasts, and may contribute to the pathophysiology underlying colitis-associated cancer.

Downregulation of a newly identified laminin, laminin-3B11, in vascular basement membranes of invasive human breast cancers

Laminins present in the basement membranes (BM) of blood vessels are involved in angiogenesis and other vascular functions that are critical for tumor growth and metastasis. Two major vascular laminins, the α4 (laminin-411/421) and α5 (laminin-511/521) types, have been well characterized. We recently found a third type of vascular laminin, laminin-3B11, consisting of the α3B, β1 and γ1 chains, and revealed its biological activity. Laminin-3B11 potently stimulates vascular endothelial cells to extend lamellipodial protrusions. To understand the roles of laminin-3B11 in blood vessel functions and tumor growth, we examined localization of the laminin α3B chain in normal mammary glands and breast cancers, in comparison with the α4 and α5 laminins. In the immunohistochemical analysis, the α3B laminin was co-localized with the α4 and α5 laminins in the BM of venules and capillaries of normal breast tissues, but α3B was scarcely detected in vessels near invasive breast carcinoma cells. In contrast, the α4 laminin was overexpressed in capillaries of invasive carcinomas, where a large number of macrophages were found. The α5 laminin appeared to be weakly downregulated in cancer tissues, especially in capillary vessels. Furthermore, our in vitro analysis indicated that TNF-α significantly suppressed the laminin α3B expression in vascular endothelial cells, while it, as well as IL-1β and TGF-α, upregulated the α4 expression. These results suggest that Lm3B11/3B21 may be required for normal mature vessels and interfere with tumor angiogenesis.

Isolation and identification of anti-inflammatory constituents from Ligusticum chuanxiong and their underlying mechanisms of action on microglia

Stroke is the third most common cause of death worldwide. Recent findings showed that the severity of cerebrovascular diseases including ischemic stroke correlates with inflammation mediated responses in the neural cells. During ischemia, inflammatory mediators including tumor necrosis factor-alpha (TNF-α) and nitric oxide are produced by microglia, which play a central role in the pathogenesis of the disease. Ligusticum chuanxiong (LCX) is a commonly used traditional Chinese medicine (TCM) for empiric treatment of cerebrovascular and cardiovascular diseases for many centuries. By applying a bioactivity-guided fractionation scheme, two compounds with inhibition on neuroinflammation were isolated from LCX. Using chromatographic and spectrometric methods, they were identified to be senkyunolide A and Z-ligustilide. They could inhibit the production of proinflammatory mediators in lipopolysaccharide (LPS)-stimulated murine BV-2 microglial cells and human peripheral blood monocyte derived macrophages. In addition, both compounds protected Neuro-2a cells from neuroinflammatory toxicity induced by the conditioned culture media produced by LPS-stimulated BV-2 cells. The underlying mechanisms of action of senkyunolide A were further delineated. Its inhibitory effects were shown to be independent of the phosphorylation of mitogen-activated protein kinases (MAPK) and translocation of nuclear factor kappa B (NF-κB). However, senkyunolide A could increase the degradation of TNF-α mRNA and reduce its half life by 43%. In conclusion, bioactivity-guided fractionation is an effective way of isolating bioactive compounds from medicinal herbs. In addition, senkyunolide A and Z-ligustilide isolated from LCX may be considered as potential complementary drug candidates for treating inflammatory processes associated with cerebrovascular diseases.

Effect of tumour necrosis factor-α in combination with interferon-γ on first trimester extravillous trophoblast invasion

Successful pregnancy is dependent upon invasion of the uterine tissues by extravillous trophoblast cells (EVT). The mechanisms that control trophoblast invasion are unclear, but several cytokines and growth factors appear to be involved. We have previously demonstrated that IFN-γ inhibits EVT invasion via a mechanism partially dependent on an increase in EVT apoptosis and decreased secretion of matrix metalloproteinase (MMP)-2. In the current study we show that TNF-α, both alone and in combination with IFN-γ, inhibits EVT invasion via a mechanism associated with increased trophoblast apoptosis, decreased trophoblast proliferation and/or altered production of active proteases. TNF-α and its receptors, TNF-αRI and TNF-αRII, were immunolocalised in the placental bed. Uterine natural killer (uNK) cells, EVT and villous cytotrophoblast were shown to all produce TNF-α, and TNF-α receptors were primarily immunolocalised to EVT in the placental bed. TNF-α increased EVT apoptosis, decreased villous cytotrophoblast proliferation and increased expression of pro-MMP-9 (but not active MMP-9), urokinase plasminogen activator (uPA) and plasminogen activator inhibitor (PAI)-1 by EVT. The combination of TNF-α and IFN-γ inhibited EVT via a mechanism associated with increased EVT apoptosis, reduced proliferation, reduced pro-MMP-2 secretion and increased secretion of uPA. TNF-α is one of several decidua-derived factors with the capacity to inhibit EVT invasion. The mode of activity of TNF-α was modified by the presence of IFN-γ, suggesting that the local cytokine milieu may be critical in determining spatial and/or temporal changes in EVT invasion.

Comparative expression pattern of Matrix-Metalloproteinases in human glioblastoma cell-lines and primary cultures

Background

Glioblastomas (GBM), the most frequent malignant brain tumors in adults, are characterized by an aggressive local growth pattern and highly invasive tumor cells. This invasion is facilitated by expression of matrix metalloproteinases (MMPs), a family of zinc-dependent endopeptidases. They mediate the degradation of protein components of the extracellular matrix. Twenty-three family members are known. Elevated levels of several of them have been reported in GBM. GBM cell-lines are used for in vitro studies of cell migration and invasion. Therefore, it is essential to know their MMP expression patterns. Only limited data for some of the cell-lines are published, yet. To fill the gaps in our knowledge would help to choose suitable model systems for analysis of regulation and function of MMPs during GBM tumorigenesis, cell migration and invasion.

Findings

We analysed MMP-1, -8, -9, -10, -11, -13, -17, -19, -20, -21, -23, -24, -26, -27, and MMP-28 expression in seven GBM cell-lines (SNB-19, GaMG, U251, U87, U373, U343, U138) and in four primary cell cultures by semiquantitative RT-PCR, followed changes in the MMP expression pattern with increasing passages of cell culture and examined the influence of TNF-α and TGF-β1 stimulation on the expression of selected MMPs in U251 and U373 cells.

MMP-13, -17, -19 and -24 were expressed by all analyzed cell-lines, whereas MMP-20 and MMP-21 were not expressed by any of them. The other MMPs showed variable expression, which was dependent on passage number. Primary cells displayed a similar MMP-expression pattern as the cell-lines. In U251 and U373 cells expression of MMP-9 and MMP-19 was stimulated by TNF-α. MMP-1 mRNA expression was significantly increased in U373 cells, but not in U251 cells by this cytokine. Whereas TGF-β1 had no impact on MMP expression in U251 cells, it significantly induced MMP-11 and MMP-24 expression in U373 cells.

Conclusions

Literature-data and our own results suggest that the expression pattern of MMPs is highly variable, dependent on the cell-line and the cell-culture conditions used and that also regulation of MMP expression by cytokines is cell-line dependent. This is of high impact for the transfer of cell-culture experiments to clinical implementation.

Identification of the bioactive constituent and its mechanisms of action in mediating the anti-inflammatory effects of black cohosh and related Cimicifuga species on human primary blood macrophages

Cimicifuga species have been used as traditional medicinal herbs to treat inflammation and symptoms associated with menopause in Asia, Europe, and North America. However, the underlying mechanism of their anti-inflammatory effects remains to be investigated. With bioactivity guided purification involving the use of partitioning extraction and high performance liquid chromatography, we isolated one of the key bioactive constituents from the rhizome extracts of Cimicifuga racemosa. By NMR spectroscopy, the molecule was identified to be cimiracemate A (1). This compound (140 muM) suppressed the lipopolysaccharide-induced TNF-alpha production in the blood macrophages by 47 +/- 19% and 58 +/- 30% at LPS concentrations of 1 ng/mL and 10 ng/mL, respectively. The anti-inflammatory activity of compound 1 may be due to its modulation of a signaling mitogen activated protein kinase and transcription factor nuclear factor-kappaB activities. Compound 1 was found in other Cimicifuga species. Our data indicate that compound 1 or its chemical analogues may have the potential to be further developed as a new class of therapeutic agent.

Tissue-type plasminogen activator (t-PA) induces stromelysin-1 (MMP-3) in endothelial cells through activation of lipoprotein receptor–related protein

Tissue-type plasminogen activator (t-PA) is approved for treatment of ischemic stroke patients, but it increases the risk of intracranial bleeding (ICB). Previously, we have shown in a mouse stroke model that stromelysin-1 (matrix metalloproteinase-3 [MMP-3]) induced in endothelial cells was critical for ICB induced by t-PA. In the present study, using bEnd.3 cells, a mouse brain–derived endothelial cell line, we showed that MMP-3 was induced by both ischemic stress and t-PA treatment. This induction by t-PA was prevented by inhibition either of low-density lipoprotein receptor–related protein (LRP) or of nuclear factor-κB activation. LRP was up-regulated by ischemic stress, both in bEnd.3 cells in vitro and in endothelial cells at the ischemic damage area in the mouse stroke model. Furthermore, inhibition of LRP suppressed both MMP-3 induction in endothelial cells and the increase in ICB by t-PA treatment after stroke. These findings indicate that t-PA deteriorates ICB via MMP-3 induction in endothelial cells, which is regulated through the LRP/nuclear factor-κB pathway.

Bioinformatics construction of the human cell surfaceome

Cell surface proteins are excellent targets for diagnostic and therapeutic interventions. By using bioinformatics tools, we generated a catalog of 3,702 transmembrane proteins located at the surface of human cells (human cell surfaceome). We explored the genetic diversity of the human cell surfaceome at different levels, including the distribution of polymorphisms, conservation among eukaryotic species, and patterns of gene expression. By integrating expression information from a variety of sources, we were able to identify surfaceome genes with a restricted expression in normal tissues and/or differential expression in tumors, important characteristics for putative tumor targets. A high-throughput and efficient quantitative real-time PCR approach was used to validate 593 surfaceome genes selected on the basis of their expression pattern in normal and tumor samples. A number of candidates were identified as potential diagnostic and therapeutic targets for colorectal tumors and glioblastoma. Several candidate genes were also identified as coding for cell surface cancer/testis antigens. The human cell surfaceome will serve as a reference for further studies aimed at characterizing tumor targets at the surface of human cells.

HIV-1 transactivator protein induction of suppressor of cytokine signaling-2 contributes to dysregulation of IFN{gamma} signaling

HIV infection remains a worldwide threat. HIV-1 transactivator protein Tat is one of the retroviral proteins identified as a key immunomodulator in AIDS pathogenesis. Although the primary function of Tat is to regulate HIV-1 replication in the infected cell, it also dysregulates cytokine production resulting in perturbation of the host immune response and enhancement of the retrovirus survival. Because interferon-gamma (IFNgamma) is a pleiotropic cytokine with potent antiviral and immunoregulatory effects, we investigated whether Tat interferes with the IFNgamma signal transduction in primary monocytes. We demonstrated that Tat impaired the IFNgamma-receptor signaling pathway at the level of STAT1 activation, possibly via Tat-dependent induction of suppressor of cytokine signaling-2 (SOCS-2) activity. We delineated the inhibitory role of SOCS-2 in IFNgamma signaling pathway by overexpression of exogenous SOCS-2 in HEK293 cell. The results showed that SOCS-2 suppressed the IFNgamma-activated STAT1 phosphorylation and consequent IFNgamma-regulated transcription of specific genes. To confirm the role of SOCS2 in the Tat-induced process, we demonstrated that SOCS-2 siRNA in human blood monocytes abrogated the Tat-dependent inhibition of IFNgamma signaling. Our data suggested a possible mechanism implicating the role of SOCS-2 in mediating HIV-1-induced immune evasion and dysregulation of IFNgamma signaling in primary human monocytes.

Tumor necrosis factor and cancer, buddies or foes?

Tumor necrosis factor (TNF) is a multifunctional cytokine that plays important roles in diverse cellular events such as cell survival, proliferation, differentiation, and death. As a pro-inflammatory cytokine, TNF is secreted by inflammatory cells, which may be involved in inflammation-associated carcinogenesis. TNF exerts its biological functions through activating distinct signaling pathways such as nuclear factor-kappaB (NF-kappaB) and c-Jun N-terminal kinase (JNK). NF-kappaB is a major cell survival signal that is anti-apoptotic, whereas sustained JNK activation contributes to cell death. The crosstalk between the NF-kappaB and JNK is involved in determining cellular outcomes in response to TNF. In regard to cancer, TNF is a double-dealer. On one hand, TNF could be an endogenous tumor promoter, because TNF stimulates the growth, proliferation, invasion and metastasis, and tumor angiogenesis of cancer cells. On the other hand, TNF could be a cancer killer. The property of TNF in inducing cancer cell death renders it a potential cancer therapeutic, although much work is needed to reduce its toxicity for systematic TNF administration. Recent studies have focused on sensitizing cancer cells to TNF-induced apoptosis through inhibiting survival signals such as NF-kappaB, by combined therapy. In this article we provide an overview of the roles of TNF-induced signaling pathways in cancer biology with specific emphasis on carcinogenesis and cancer therapy.