Export of a Toxoplasma gondii rhoptry neck protein complex at the host cell membrane to form the moving junction during invasion.

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Sébastien Besteiro

2009-02-01

Full Text Available One of the most conserved features of the invasion process in Apicomplexa parasites is the formation of a moving junction (MJ between the apex of the parasite and the host cell membrane that moves along the parasite and serves as support to propel it inside the host cell. The MJ was, up to a recent period, completely unknown at the molecular level. Recently, proteins originated from two distinct post-Golgi specialised secretory organelles, the micronemes (for AMA1 and the neck of the rhoptries (for RON2/RON4/RON5 proteins, have been shown to form a complex. AMA1 and RON4 in particular, have been localised to the MJ during invasion. Using biochemical approaches, we have identified RON8 as an additional member of the complex. We also demonstrated that all RON proteins are present at the MJ during invasion. Using metabolic labelling and immunoprecipitation, we showed that RON2 and AMA1 were able to interact in the absence of the other members. We also discovered that all MJ proteins are subjected to proteolytic maturation during trafficking to their respective organelles and that they could associate as non-mature forms in vitro. Finally, whereas AMA1 has previously been shown to be inserted into the parasite membrane upon secretion, we demonstrated, using differential permeabilization and loading of RON-specific antibodies into the host cell, that the RON complex is targeted to the host cell membrane, where RON4/5/8 remain associated with the cytoplasmic face. Globally, these results point toward a model of MJ organization where the parasite would be secreting and inserting interacting components on either side of the MJ, both at the host and at its own plasma membranes.

Adhesion to the host cell surface is sufficient to mediate Listeria monocytogenes entry into epithelial cells

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Ortega, Fabian E.; Rengarajan, Michelle; Chavez, Natalie; Radhakrishnan, Prathima; Gloerich, Martijn; Bianchini, Julie; Siemers, Kathleen; Luckett, William S.; Lauer, Peter; Nelson, W. James; Theriot, Julie A.

2017-01-01

The intestinal epithelium is the first physiological barrier breached by the Gram-positive facultative pathogen Listeria monocytogenes during an in vivo infection. Listeria monocytogenes binds to the epithelial host cell receptor E-cadherin, which mediates a physical link between the bacterium and filamentous actin (F-actin). However, the importance of anchoring the bacterium to F-actin through E-cadherin for bacterial invasion has not been tested directly in epithelial cells. Here we demonstrate that depleting αE-catenin, which indirectly links E-cadherin to F-actin, did not decrease L. monocytogenes invasion of epithelial cells in tissue culture. Instead, invasion increased due to increased bacterial adhesion to epithelial monolayers with compromised cell–cell junctions. Furthermore, expression of a mutant E-cadherin lacking the intracellular domain was sufficient for efficient L. monocytogenes invasion of epithelial cells. Importantly, direct biotin-mediated binding of bacteria to surface lipids in the plasma membrane of host epithelial cells was sufficient for uptake. Our results indicate that the only requirement for L. monocytogenes invasion of epithelial cells is adhesion to the host cell surface, and that E-cadherin–mediated coupling of the bacterium to F-actin is not required. PMID:28877987

Phytophagous insect fauna tracks host plant responses to exotic grass invasion.

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Almeida-Neto, Mário; Prado, Paulo I; Lewinsohn, Thomas M

2011-04-01

The high dependence of herbivorous insects on their host plants implies that plant invaders can affect these insects directly, by not providing a suitable habitat, or indirectly, by altering host plant availability. In this study, we sampled Asteraceae flower heads in cerrado remnants with varying levels of exotic grass invasion to evaluate whether invasive grasses have a direct effect on herbivore richness independent of the current disturbance level and host plant richness. By classifying herbivores according to the degree of host plant specialization, we also investigated whether invasive grasses reduce the uniqueness of the herbivorous assemblages. Herbivorous insect richness showed a unimodal relationship with invasive grass cover that was significantly explained only by way of the variation in host plant richness. The same result was found for polyphagous and oligophagous insects, but monophages showed a significant negative response to the intensity of the grass invasion that was independent of host plant richness. Our findings lend support to the hypothesis that the aggregate effect of invasive plants on herbivores tends to mirror the effects of invasive plants on host plants. In addition, exotic plants affect specialist insects differently from generalist insects; thus exotic plants affect not only the size but also the structural profile of herbivorous insect assemblages.

Campylobacter jejuni type VI secretion system: roles in adaptation to deoxycholic acid, host cell adherence, invasion, and in vivo colonization.

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Lertpiriyapong, Kvin; Gamazon, Eric R; Feng, Yan; Park, Danny S; Pang, Jassia; Botka, Georgina; Graffam, Michelle E; Ge, Zhongming; Fox, James G

2012-01-01

The recently identified type VI secretion system (T6SS) of proteobacteria has been shown to promote pathogenicity, competitive advantage over competing microorganisms, and adaptation to environmental perturbation. By detailed phenotypic characterization of loss-of-function mutants, in silico, in vitro and in vivo analyses, we provide evidence that the enteric pathogen, Campylobacter jejuni, possesses a functional T6SS and that the secretion system exerts pleiotropic effects on two crucial processes--survival in a bile salt, deoxycholic acid (DCA), and host cell adherence and invasion. The expression of T6SS during initial exposure to the upper range of physiological levels of DCA (0.075%-0.2%) was detrimental to C. jejuni proliferation, whereas down-regulation or inactivation of T6SS enabled C. jejuni to resist this effect. The C. jejuni multidrug efflux transporter gene, cmeA, was significantly up-regulated during the initial exposure to DCA in the wild type C. jejuni relative to the T6SS-deficient strains, suggesting that inhibition of proliferation is the consequence of T6SS-mediated DCA influx. A sequential modulation of the efflux transporter activity and the T6SS represents, in part, an adaptive mechanism for C. jejuni to overcome this inhibitory effect, thereby ensuring its survival. C. jejuni T6SS plays important roles in host cell adhesion and invasion as T6SS inactivation resulted in a reduction of adherence to and invasion of in vitro cell lines, while over-expression of a hemolysin co-regulated protein, which encodes a secreted T6SS component, greatly enhanced these processes. When inoculated into B6.129P2-IL-10(tm1Cgn) mice, the T6SS-deficient C. jejuni strains did not effectively establish persistent colonization, indicating that T6SS contributes to colonization in vivo. Taken together, our data demonstrate the importance of bacterial T6SS in host cell adhesion, invasion, colonization and, for the first time to our knowledge, adaptation to DCA

Campylobacter jejuni type VI secretion system: roles in adaptation to deoxycholic acid, host cell adherence, invasion, and in vivo colonization.

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Kvin Lertpiriyapong

Full Text Available The recently identified type VI secretion system (T6SS of proteobacteria has been shown to promote pathogenicity, competitive advantage over competing microorganisms, and adaptation to environmental perturbation. By detailed phenotypic characterization of loss-of-function mutants, in silico, in vitro and in vivo analyses, we provide evidence that the enteric pathogen, Campylobacter jejuni, possesses a functional T6SS and that the secretion system exerts pleiotropic effects on two crucial processes--survival in a bile salt, deoxycholic acid (DCA, and host cell adherence and invasion. The expression of T6SS during initial exposure to the upper range of physiological levels of DCA (0.075%-0.2% was detrimental to C. jejuni proliferation, whereas down-regulation or inactivation of T6SS enabled C. jejuni to resist this effect. The C. jejuni multidrug efflux transporter gene, cmeA, was significantly up-regulated during the initial exposure to DCA in the wild type C. jejuni relative to the T6SS-deficient strains, suggesting that inhibition of proliferation is the consequence of T6SS-mediated DCA influx. A sequential modulation of the efflux transporter activity and the T6SS represents, in part, an adaptive mechanism for C. jejuni to overcome this inhibitory effect, thereby ensuring its survival. C. jejuni T6SS plays important roles in host cell adhesion and invasion as T6SS inactivation resulted in a reduction of adherence to and invasion of in vitro cell lines, while over-expression of a hemolysin co-regulated protein, which encodes a secreted T6SS component, greatly enhanced these processes. When inoculated into B6.129P2-IL-10(tm1Cgn mice, the T6SS-deficient C. jejuni strains did not effectively establish persistent colonization, indicating that T6SS contributes to colonization in vivo. Taken together, our data demonstrate the importance of bacterial T6SS in host cell adhesion, invasion, colonization and, for the first time to our knowledge

Whole-Genome Sequencing of Invasion-Resistant Cells Identifies Laminin α2 as a Host Factor for Bacterial Invasion

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van Wijk, Xander M.; Döhrmann, Simon; Hallstrom, Bjorn

2017-01-01

cells. Whole-genome sequencing and transcriptome sequencing (RNA-Seq) uncovered a deletion in the gene encoding the laminin subunit α2 (Lama2) that eliminated much of domain L4a. Silencing of the long Lama2 isoform in wild-type cells strongly reduced bacterial invasion, whereas transfection with human...... LAMA2 cDNA significantly enhanced invasion in pgsA745 cells. The addition of exogenous laminin-α2β1γ1/laminin-α2β2γ1 strongly increased bacterial invasion in CHO cells, as well as in human alveolar basal epithelial and human brain microvascular endothelial cells. Thus, the L4a domain in laminin α2...

Apicomplexans pulling the strings: manipulation of the host cell cytoskeleton dynamics.

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Cardoso, Rita; Soares, Helena; Hemphill, Andrew; Leitão, Alexandre

2016-07-01

Invasive stages of apicomplexan parasites require a host cell to survive, proliferate and advance to the next life cycle stage. Once invasion is achieved, apicomplexans interact closely with the host cell cytoskeleton, but in many cases the different species have evolved distinct mechanisms and pathways to modulate the structural organization of cytoskeletal filaments. The host cell cytoskeleton is a complex network, largely, but not exclusively, composed of microtubules, actin microfilaments and intermediate filaments, all of which are modulated by associated proteins, and it is involved in diverse functions including maintenance of cell morphology and mechanical support, migration, signal transduction, nutrient uptake, membrane and organelle trafficking and cell division. The ability of apicomplexans to modulate the cytoskeleton to their own advantage is clearly beneficial. We here review different aspects of the interactions of apicomplexans with the three main cytoskeletal filament types, provide information on the currently known parasite effector proteins and respective host cell targets involved, and how these interactions modulate the host cell physiology. Some of these findings could provide novel targets that could be exploited for the development of preventive and/or therapeutic strategies.

In vitro inhibition of Eimeria tenella sporozoite invasion into host cells by probiotics.

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Hessenberger, S; Schatzmayr, G; Teichmann, K

2016-10-15

The aim was to study the effects of probiotics isolated from the intestinal tract of livestock animals on Eimeria tenella invasion into Madin-Darby bovine kidney (MDBK) cells in vitro. E. tenella sporozoites were purified and labeled with 5(6)-carboxyfluorescein diacetate N-succinimidyl ester before seeding on cell cultures, and invasion was evaluated by fluorescence microscopy. Two protocols (A and B) were used. In protocol A, Enterococcus faecium # 589 or Lactobacillus salivarius subsp. salivarius # 505 were added together with sporozoites to MDBK cell cultures and invasion was evaluated after incubation for approximately 20h. Viable, dead, or spent culture supernatants of probiotics were tested. In protocol B, viable probiotics were incubated with MDBK cells for one hour before sporozoites were added and invasion was evaluated after two more hours of incubation. Parasite invasion of viable, dead, or spent culture supernatant of E. faecium # 589 was assessed. Using protocol A, it was shown that parasite invasion was inhibited by viable (80%) or dead (75%) E. faecium # 589. While inhibition by viable L. salivarius subsp. salivarius # 505 was not valid at the highest concentration and not significant at the other test concentrations, dead cells inhibited parasite invasion up to 45%. Spent culture supernatants of both probiotics had no influence on parasite invasion. Using protocol B, it was shown that viable Bifidobacterium animalis subsp. animalis # 503, E. faecium # 497, E. faecium # 589, L. reuteri # 514, L. salivarius subsp. salivarius # 505, and Bacillus subtilis # 588 inhibited parasite invasion into MDBK cells up to 80%. Anticoccidial activity was strain-specific for E. faecium strains, and the strongest effect was shown by E. faecium # 589. Anticoccidial effects of some of the tested probiotics have already been shown in vivo, which makes them candidates to prevent coccidiosis. These findings have now been confirmed in vitro. The used parasite invasion

Invasion of Ureaplasma diversum in Hep-2 cells

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Braga Antonio

2010-03-01

Full Text Available Abstract Background Understanding mollicutes is challenging due to their variety and relationship with host cells. Invasion has explained issues related to their opportunistic role. Few studies have been done on the Ureaplasma diversum mollicute, which is detected in healthy or diseased bovine. The invasion in Hep-2 cells of four clinical isolates and two reference strains of their ureaplasma was studied by Confocal Laser Scanning Microscopy and gentamicin invasion assay. Results The isolates and strains used were detected inside the cells after infection of one minute without difference in the arrangement for adhesion and invasion. The adhesion was scattered throughout the cells, and after three hours, the invasion of the ureaplasmas surrounded the nuclear region but were not observed inside the nuclei. The gentamicin invasion assay detected that 1% of the ATCC strains were inside the infected Hep-2 cells in contrast to 10% to the clinical isolates. A high level of phospholipase C activity was also detected in all studied ureaplasma. Conclusions The results presented herein will help better understand U. diversum infections, aswell as cellular attachment and virulence.

A novel role of the ferric reductase Cfl1 in cell wall integrity, mitochondrial function, and invasion to host cells in Candida albicans.

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Yu, Qilin; Dong, Yijie; Xu, Ning; Qian, Kefan; Chen, Yulu; Zhang, Biao; Xing, Laijun; Li, Mingchun

2014-11-01

Candida albicans is an important opportunistic pathogen, causing both superficial mucosal infections and life-threatening systemic diseases. Iron acquisition is an important factor for pathogen-host interaction and also a significant element for the pathogenicity of this organism. Ferric reductases, which convert ferric iron into ferrous iron, are important components of the high-affinity iron uptake system. Sequence analyses have identified at least 17 putative ferric reductase genes in C. albicans genome. CFL1 was the first ferric reductase identified in C. albicans. However, little is known about its roles in C. albicans physiology and pathogenicity. In this study, we found that disruption of CFL1 led to hypersensitivity to chemical and physical cell wall stresses, activation of the cell wall integrity (CWI) pathway, abnormal cell wall composition, and enhanced secretion, indicating a defect in CWI in this mutant. Moreover, this mutant showed abnormal mitochondrial activity and morphology, suggesting a link between ferric reductases and mitochondrial function. In addition, this mutant displayed decreased ability of adhesion to both the polystyrene microplates and buccal epithelial cells and invasion of host epithelial cells. These findings revealed a novel role of C. albicans Cfl1 in maintenance of CWI, mitochondrial function, and interaction between this pathogen and the host. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

The Inside Story of Shigella Invasion of Intestinal Epithelial Cells

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Carayol, Nathalie; Tran Van Nhieu, Guy

2013-01-01

As opposed to other invasive pathogens that reside into host cells in a parasitic mode, Shigella, the causative agent of bacillary dysentery, invades the colonic mucosa but does not penetrate further to survive into deeper tissues. Instead, Shigella invades, replicates, and disseminates within the colonic mucosa. Bacterial invasion and spreading in intestinal epithelium lead to the elicitation of inflammatory responses responsible for the tissue destruction and shedding in the environment for further infection of other hosts. In this article, we highlight specific features of the Shigella arsenal of virulence determinants injected by a type III secretion apparatus (T3SA) that point to the targeting of intestinal epithelial cells as a discrete route of invasion during the initial event of the infectious process. PMID:24086068

Macropinosomes are Key Players in Early Shigella Invasion and Vacuolar Escape in Epithelial Cells.

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Allon Weiner

2016-05-01

Full Text Available Intracellular pathogens include all viruses, many bacteria and parasites capable of invading and surviving within host cells. Key to survival is the subversion of host cell pathways by the pathogen for the purpose of propagation and evading the immune system. The intracellular bacterium Shigella flexneri, the causative agent of bacillary dysentery, invades host cells in a vacuole that is subsequently ruptured to allow growth of the pathogen within the host cytoplasm. S. flexneri invasion has been classically described as a macropinocytosis-like process, however the underlying details and the role of macropinosomes in the intracellular bacterial lifestyle have remained elusive. We applied dynamic imaging and advanced large volume correlative light electron microscopy (CLEM to study the highly transient events of S. flexneri's early invasion into host epithelial cells and elucidate some of its fundamental features. First, we demonstrate a clear distinction between two compartments formed during the first step of invasion: the bacterial containing vacuole and surrounding macropinosomes, often considered identical. Next, we report a functional link between macropinosomes and the process of vacuolar rupture, demonstrating that rupture timing is dependent on the availability of macropinosomes as well as the activity of the small GTPase Rab11 recruited directly to macropinosomes. We go on to reveal that the bacterial containing vacuole and macropinosomes come into direct contact at the onset of vacuolar rupture. Finally, we demonstrate that S. flexneri does not subvert pre-existing host endocytic vesicles during the invasion steps leading to vacuolar rupture, and propose that macropinosomes are the major compartment involved in these events. These results provide the basis for a new model of the early steps of S. flexneri epithelial cell invasion, establishing a different view of the enigmatic process of cytoplasmic access by invasive bacterial

How pathogens use linear motifs to perturb host cell networks

KAUST Repository

Via, Allegra; Uyar, Bora; Brun, Christine; Zanzoni, Andreas

2015-01-01

Molecular mimicry is one of the powerful stratagems that pathogens employ to colonise their hosts and take advantage of host cell functions to guarantee their replication and dissemination. In particular, several viruses have evolved the ability to interact with host cell components through protein short linear motifs (SLiMs) that mimic host SLiMs, thus facilitating their internalisation and the manipulation of a wide range of cellular networks. Here we present convincing evidence from the literature that motif mimicry also represents an effective, widespread hijacking strategy in prokaryotic and eukaryotic parasites. Further insights into host motif mimicry would be of great help in the elucidation of the molecular mechanisms behind host cell invasion and the development of anti-infective therapeutic strategies.

Polymeric immunoglobulin receptor-mediated invasion of Streptococcus pneumoniae into host cells requires a coordinate signaling of SRC family of protein-tyrosine kinases, ERK, and c-Jun N-terminal kinase.

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Agarwal, Vaibhav; Asmat, Tauseef M; Dierdorf, Nina I; Hauck, Christof R; Hammerschmidt, Sven

2010-11-12

Streptococcus pneumoniae are commensals of the human nasopharynx with the capacity to invade mucosal respiratory cells. PspC, a pneumococcal surface protein, interacts with the human polymeric immunoglobulin receptor (pIgR) to promote bacterial adherence to and invasion into epithelial cells. Internalization of pneumococci requires the coordinated action of actin cytoskeleton rearrangements and the retrograde machinery of pIgR. Here, we demonstrate the involvement of Src protein-tyrosine kinases (PTKs), focal adhesion kinase (FAK), extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK) but not p38 mitogen-activated protein kinases (MAPK) in pneumococcal invasion via pIgR. Pharmacological inhibitors of PTKs and MAPKs and genetic interference with Src PTK and FAK functions caused a significant reduction of pIgR-mediated pneumococcal invasion but did not influence bacterial adhesion to host cells. Furthermore, pneumococcal ingestion by host cells induces activation of ERK1/2 and JNK. In agreement with activated JNK, its target molecule and DNA-binding protein c-Jun was phosphorylated. We also show that functionally active Src PTK is essential for activation of ERK1/2 upon pneumococcal infections. In conclusion, these data illustrate the importance of a coordinated signaling between Src PTKs, ERK1/2, and JNK during PspC-pIgR-mediated uptake of pneumococci by host epithelial cells.

Impact of sub-inhibitory antibiotics on fibronectin-mediated host cell adhesion and invasion by Staphylococcus aureus

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Rasigade Jean

2011-12-01

Full Text Available Abstract Background Staphylococcus aureus is a well-armed pathogen prevalent in severe infections such as endocarditis and osteomyelitis. Fibronectin-binding proteins A and B, encoded by fnbA/B, are major pathogenesis determinants in these infections through their involvement in S. aureus adhesion to and invasion of host cells. Sub-minimum inhibitory concentrations (sub-MICs of antibiotics, frequently occurring in vivo because of impaired drug diffusion at the infection site, can alter S. aureus phenotype. We therefore investigated their impact on S. aureus fibronectin-mediated adhesiveness and invasiveness. Methods After in vitro challenge of S. aureus 8325-4 and clinical isolates with sub-MICs of major anti-staphylococcal agents, we explored fnbA/B transcription levels, bacterial adhesiveness to immobilised human fibronectin and human osteoblasts in culture, and bacterial invasion of human osteoblasts. Results Oxacillin, moxifloxacin and linezolid led to the development of a hyper-adhesive phenotype in the fibronectin adhesion assay that was consistent with an increase in fnbA/B transcription. Conversely, rifampin treatment decreased fibronectin binding in all strains tested without affecting fnbA/B transcription. Gentamicin and vancomycin had no impact on fibronectin binding or fnbA/B transcription levels. Only oxacillin-treated S. aureus displayed a significantly increased adhesion to cultured osteoblasts, but its invasiveness did not differ from that of untreated controls. Conclusion Our findings demonstrate that several antibiotics at sub-MICs modulate fibronectin binding in S. aureus in a drug-specific fashion. However, hyper- and hypo- adhesive phenotypes observed in controlled in vitro conditions were not fully confirmed in whole cell infection assays. The relevance of adhesion modulation during in vivo infections is thus still uncertain and requires further investigations.

Molecular Characterization of a Novel Family of Trypanosoma cruzi Surface Membrane Proteins (TcSMP) Involved in Mammalian Host Cell Invasion.

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Martins, Nadini Oliveira; Souza, Renata Torres de; Cordero, Esteban Mauricio; Maldonado, Danielle Cortez; Cortez, Cristian; Marini, Marjorie Mendes; Ferreira, Eden Ramalho; Bayer-Santos, Ethel; Almeida, Igor Correia de; Yoshida, Nobuko; Silveira, José Franco da

2015-11-01

The surface coat of Trypanosoma cruzi is predominantly composed of glycosylphosphatidylinositol-anchored proteins, which have been extensively characterized. However, very little is known about less abundant surface proteins and their role in host-parasite interactions. Here, we described a novel family of T. cruzi surface membrane proteins (TcSMP), which are conserved among different T. cruzi lineages and have orthologs in other Trypanosoma species. TcSMP genes are densely clustered within the genome, suggesting that they could have originated by tandem gene duplication. Several lines of evidence indicate that TcSMP is a membrane-spanning protein located at the cellular surface and is released into the extracellular milieu. TcSMP exhibited the key elements typical of surface proteins (N-terminal signal peptide or signal anchor) and a C-terminal hydrophobic sequence predicted to be a trans-membrane domain. Immunofluorescence of live parasites showed that anti-TcSMP antibodies clearly labeled the surface of all T. cruzi developmental forms. TcSMP peptides previously found in a membrane-enriched fraction were identified by proteomic analysis in membrane vesicles as well as in soluble forms in the T. cruzi secretome. TcSMP proteins were also located intracellularly likely associated with membrane-bound structures. We demonstrated that TcSMP proteins were capable of inhibiting metacyclic trypomastigote entry into host cells. TcSMP bound to mammalian cells and triggered Ca2+ signaling and lysosome exocytosis, events that are required for parasitophorous vacuole biogenesis. The effects of TcSMP were of lower magnitude compared to gp82, the major adhesion protein of metacyclic trypomastigotes, suggesting that TcSMP may play an auxiliary role in host cell invasion. We hypothesized that the productive interaction of T. cruzi with host cells that effectively results in internalization may depend on diverse adhesion molecules. In the metacyclic forms, the signaling induced by

Invasion of Eukaryotic Cells by Legionella Pneumophila: A Common Strategy for all Hosts?

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Paul S Hoffman

1997-01-01

Full Text Available Legionella pneumophila is an environmental micro-organism capable of producing an acute lobar pneumonia, commonly referred to as Legionnaires’ disease, in susceptible humans. Legionellae are ubiquitous in aquatic environments, where they survive in biofilms or intracellularly in various protozoans. Susceptible humans become infected by breathing aerosols laden with the bacteria. The target cell for human infection is the alveolar macrophage, in which the bacteria abrogate phagolysosomal fusion. The remarkable ability of L pneumophila to infect a wide range of eukaryotic cells suggests a common strategy that exploits very fundamental cellular processes. The bacteria enter host cells via coiling phagocytosis and quickly subvert organelle trafficking events, leading to formation of a replicative phagosome in which the bacteria multiply. Vegetative growth continues for 8 to 10 h, after which the bacteria develop into a short, highly motile form called the ‘mature form’. The mature form exhibits a thickening of the cell wall, stains red with the Gimenez stain, and is between 10 and 100 times more infectious than agar-grown bacteria. Following host cell lysis, the released bacteria infect other host cells, in which the mature form differentiates into a Gimenez-negative vegetative form, and the cycle begins anew. Virulence of L pneumophila is considered to be multifactorial, and there is growing evidence for both stage specific and sequential gene expression. Thus, L pneumophila may be a good model system for dissecting events associated with the host-parasite interactions.

Activity of xyloglucan endotransglucosylases/hydrolases suggests a role during host invasion by the parasitic plant Cuscuta reflexa.

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Olsen, Stian; Krause, Kirsten

2017-01-01

The parasitic vines of the genus Cuscuta form haustoria that grow into other plants and connect with their vascular system, thus allowing the parasite to feed on its host. A major obstacle that meets the infection organ as it penetrates the host tissue is the rigid plant cell wall. In the present study, we examined the activity of xyloglucan endotransglucosylases/hydrolases (XTHs) during the host-invasive growth of the haustorium. The level of xyloglucan endotransglucosylation (XET) activity was found to peak at the penetrating stage of Cuscuta reflexa on its host Pelargonium zonale. In vivo colocalization of XET activity and donor substrate demonstrated XET activity at the border between host and parasite. A test for secretion of XET-active enzymes from haustoria of C. reflexa corroborated this and further indicated that the xyloglucan-modifying enzymes originated from the parasite. A known inhibitor of XET, Coomassie Brilliant Blue R250, was shown to reduce the level of XET in penetrating haustoria of C. reflexa. Moreover, the coating of P. zonale petioles with the inhibitor compound lowered the number of successful haustorial invasions of this otherwise compatible host plant. The presented data indicate that the activity of Cuscuta XTHs at the host-parasite interface is essential to penetration of host plant tissue.

Identification of molecular pathways facilitating glioma cell invasion in situ.

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Ido Nevo

Full Text Available Gliomas are mostly incurable secondary to their diffuse infiltrative nature. Thus, specific therapeutic targeting of invasive glioma cells is an attractive concept. As cells exit the tumor mass and infiltrate brain parenchyma, they closely interact with a changing micro-environmental landscape that sustains tumor cell invasion. In this study, we used a unique microarray profiling approach on a human glioma stem cell (GSC xenograft model to explore gene expression changes in situ in Invading Glioma Cells (IGCs compared to tumor core, as well as changes in host cells residing within the infiltrated microenvironment relative to the unaffected cortex. IGCs were found to have reduced expression of genes within the extracellular matrix compartment, and genes involved in cell adhesion, cell polarity and epithelial to mesenchymal transition (EMT processes. The infiltrated microenvironment showed activation of wound repair and tissue remodeling networks. We confirmed by protein analysis the downregulation of EMT and polarity related genes such as CD44 and PARD3 in IGCs, and EFNB3, a tissue-remodeling agent enriched at the infiltrated microenvironment. OLIG2, a proliferation regulator and glioma progenitor cell marker upregulated in IGCs was found to function in enhancing migration and stemness of GSCs. Overall, our results unveiled a more comprehensive picture of the complex and dynamic cell autonomous and tumor-host interactive pathways of glioma invasion than has been previously demonstrated. This suggests targeting of multiple pathways at the junction of invading tumor and microenvironment as a viable option for glioma therapy.

Cellular Aspects of Shigella Pathogenesis: Focus on the Manipulation of Host Cell Processes.

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Killackey, Samuel A; Sorbara, Matthew T; Girardin, Stephen E

2016-01-01

Shigella is a Gram-negative bacterium that is responsible for shigellosis. Over the years, the study of Shigella has provided a greater understanding of how the host responds to bacterial infection, and how bacteria have evolved to effectively counter the host defenses. In this review, we provide an update on some of the most recent advances in our understanding of pivotal processes associated with Shigella infection, including the invasion into host cells, the metabolic changes that occur within the bacterium and the infected cell, cell-to-cell spread mechanisms, autophagy and membrane trafficking, inflammatory signaling and cell death. This recent progress sheds a new light into the mechanisms underlying Shigella pathogenesis, and also more generally provides deeper understanding of the complex interplay between host cells and bacterial pathogens in general.

Gene expression plasticity across hosts of an invasive scale insect species

DEFF Research Database (Denmark)

Christodoulides, Nicholas; Van Dam, Alex; Peterson, Daniel A.

2017-01-01

For plant-eating insects, we still have only a nascent understanding of the genetic basis of host-use promiscuity. Here, to improve that situation, we investigated host-induced gene expression plasticity in the invasive lobate lac scale insect, Paratachardina pseudolobata (Hemiptera: Keriidae). We...

Bst1 is required for Candida albicans infecting host via facilitating cell wall anchorage of Glycosylphosphatidyl inositol anchored proteins

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Liu, Wei; Zou, Zui; Huang, Xin; Shen, Hui; He, Li Juan; Chen, Si Min; Li, Li Ping; Yan, Lan; Zhang, Shi Qun; Zhang, Jun Dong; Xu, Zheng; Xu, Guo Tong; An, Mao Mao; Jiang, Yuan Ying

2016-01-01

Glycosylphosphatidyl inositol anchored proteins (GPI-APs) on fungal cell wall are essential for invasive infections. While the function of inositol deacylation of GPI-APs in mammalian cells has been previously characterized the impact of inositol deacylation in fungi and implications to host infection remains largely unexplored. Herein we describe our identification of BST1, an inositol deacylase of GPI-Aps in Candida albicans, was critical for GPI-APs cell wall attachment and host infection. BST1-deficient C. albicans (bst1Δ/Δ) was associated with severely impaired cell wall anchorage of GPI-APs and subsequen unmasked β-(1,3)-glucan. Consistent with the aberrant cell wall structures, bst1Δ/Δ strain did not display an invasive ability and could be recognized more efficiently by host immune systems. Moreover, BST1 null mutants or those expressing Bst1 variants did not display inositol deacylation activity and exhibited severely attenuated virulence and reduced organic colonization in a murine systemic candidiasis model. Thus, Bst1 can facilitate cell wall anchorage of GPI-APs in C. albicans by inositol deacylation, and is critical for host invasion and immune escape. PMID:27708385

Host Cell Responses to Persistent Mycoplasmas - Different Stages in Infection of HeLa Cells with Mycoplasma hominis

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Hopfe, Miriam; Deenen, René; Degrandi, Daniel; Köhrer, Karl; Henrich, Birgit

2013-01-01

Mycoplasma hominis is a facultative human pathogen primarily associated with bacterial vaginosis and pelvic inflammatory disease, but it is also able to spread to other sites, leading to arthritis or, in neonates, meningitis. With a minimal set of 537 annotated genes, M. hominis is the second smallest self-replicating mycoplasma and thus an ideal model organism for studying the effects of an infectious agent on its host more closely. M. hominis adherence, colonisation and invasion of HeLa cells were characterised in a time-course study using scanning electron microscopy, confocal microscopy and microarray-based analysis of the HeLa cell transcriptome. At 4 h post infection, cytoadherence of M. hominis to the HeLa cell surface was accompanied by differential regulation of 723 host genes (>2 fold change in expression). Genes associated with immune responses and signal transduction pathways were mainly affected and components involved in cell-cycle regulation, growth and death were highly upregulated. At 48 h post infection, when mycoplasma invasion started, 1588 host genes were differentially expressed and expression of genes for lysosome-specific proteins associated with bacterial lysis was detected. In a chronically infected HeLa cell line (2 weeks), the proportion of intracellular mycoplasmas reached a maximum of 10% and M. hominis-filled protrusions of the host cell membrane were seen by confocal microscopy, suggesting exocytotic dissemination. Of the 1972 regulated host genes, components of the ECM-receptor interaction pathway and phagosome-related integrins were markedly increased. The immune response was quite different to that at the beginning of infection, with a prominent induction of IL1B gene expression, affecting pathways of MAPK signalling, and genes connected with cytokine-cytokine interactions and apoptosis. These data show for the first time the complex, time-dependent reaction of the host directed at mycoplasmal clearance and the counter measures of

Effects of minimal exposures to atmospheric pressure plasma on the activity of Salmonella Typhimurium: Deactivation of bacterial motility and suppression of host-cell invasion.

Science.gov (United States)

Park, Jin-Sung; Kim, Kijung; Han, Je-Hyun; Gweon, Bomi; Ko, Ung Hyun; Yoo, Suk Jae; Choe, Wonho; Shin, Jennifer H

2016-09-01

Atmospheric pressure plasma (APP) has been shown effective in sterilization by reducing the number of viable microbes during surface cleaning, food processing, or human tissue treatment. For safe conduct, the majority of previous research focused on complete abolition of microbes, which may require severe treatments. Our aim is to investigate the minimal treatment conditions necessary for effective inactivation of bacteria in such a manner that the APP treated bacteria would not be able to harm the host cells. For this, we ought to identify the objective criteria to make the bacteria dysfunctional. We choose the motile properties and the host-cell invasion capability as two measures to quantify the pathogenic state of bacteria. In this paper, we investigated how the APP treatment in a minimal dosage affects the activity of Salmonella Typhimurium. At 100 W and 15 kHz for 20 s, the APP treatment effectively suppressed active "run and tumble" type motility and induced formation of abnormally long structures. With 20 s exposure, the bacterial cells failed to cause pyroptosis in the host cells with >90% survival after 12 h of co-incubation. Our results suggest novel measures to evaluate the functional pathogenic state for identifying safe APP treatment conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

Large-Scale Removal of Invasive Honeysuckle Decreases Mosquito and Avian Host Abundance.

Science.gov (United States)

Gardner, Allison M; Muturi, Ephantus J; Overmier, Leah D; Allan, Brian F

2017-12-01

Invasive species rank second only to habitat destruction as a threat to native biodiversity. One consequence of biological invasions is altered risk of exposure to infectious diseases in human and animal populations. The distribution and prevalence of mosquito-borne diseases depend on the complex interactions between the vector, the pathogen, and the human or wildlife reservoir host. These interactions are highly susceptible to disturbance by invasive species, including terrestrial plants. We conducted a 2-year field experiment using a Before-After/Control-Impact design to examine how removal of invasive Amur honeysuckle (Lonicera maackii) in a forest fragment embedded within a residential neighborhood affects the abundance of mosquitoes, including two of the most important vectors of West Nile virus, Culex pipiens and Cx. restuans. We also assessed any potential changes in avian communities and local microclimate associated with Amur honeysuckle removal. We found that (1) removal of Amur honeysuckle reduces the abundance of both vector and non-vector mosquito species that commonly feed on human hosts, (2) the abundance and composition of avian hosts is altered by honeysuckle removal, and (3) areas invaded with honeysuckle support local microclimates that are favorable to mosquito survival. Collectively, our investigations demonstrate the role of a highly invasive understory shrub in determining the abundance and distribution of mosquitoes and suggest potential mechanisms underlying this pattern. Our results also give rise to additional questions regarding the general impact of invasive plants on vector-borne diseases and the spatial scale at which removal of invasive plants may be utilized to effect disease control.

Sialoglycoconjugates in Trypanosoma cruzi-host cell interaction: possible biological model - a review

Directory of Open Access Journals (Sweden)

Alane Beatriz Vermelho

1994-03-01

Full Text Available A number of glycoconjugates, including glycolipids and glycoproteins, participate in the process of host-cell invasion by Trypanosoma cruzi and one of the most important carbohydrates involved on this interaction is sialic acid. It is known that parasite trans-sialidase participates with sialic acid in a coordinated fashion in the initial stages of invasion. Given the importance of these sialogycoconjugates, this review sets out various possible biological models for the interaction between the parasite and mammalian cells that possess a sialylated receptor/ligand system.

Molecular characterization of Trypanosoma cruzi SAP proteins with host-cell lysosome exocytosis-inducing activity required for parasite invasion.

Science.gov (United States)

Zanforlin, Tamiris; Bayer-Santos, Ethel; Cortez, Cristian; Almeida, Igor C; Yoshida, Nobuko; da Silveira, José Franco

2013-01-01

To invade target cells, Trypanosoma cruzi metacyclic forms engage distinct sets of surface and secreted molecules that interact with host components. Serine-, alanine-, and proline-rich proteins (SAP) comprise a multigene family constituted of molecules with a high serine, alanine and proline residue content. SAP proteins have a central domain (SAP-CD) responsible for interaction with and invasion of mammalian cells by metacyclic forms. Using a 513 bp sequence from SAP-CD in blastn analysis, we identified 39 full-length SAP genes in the genome of T. cruzi. Although most of these genes were mapped in the T. cruzi in silico chromosome TcChr41, several SAP sequences were spread out across the genome. The level of SAP transcripts was twice as high in metacyclic forms as in epimastigotes. Monoclonal (MAb-SAP) and polyclonal (anti-SAP) antibodies produced against the recombinant protein SAP-CD were used to investigate the expression and localization of SAP proteins. MAb-SAP reacted with a 55 kDa SAP protein released by epimastigotes and metacyclic forms and with distinct sets of SAP variants expressed in amastigotes and tissue culture-derived trypomastigotes (TCTs). Anti-SAP antibodies reacted with components located in the anterior region of epimastigotes and between the nucleus and the kinetoplast in metacyclic trypomastigotes. In contrast, anti-SAP recognized surface components of amastigotes and TCTs, suggesting that SAP proteins are directed to different cellular compartments. Ten SAP peptides were identified by mass spectrometry in vesicle and soluble-protein fractions obtained from parasite conditioned medium. Using overlapping sequences from SAP-CD, we identified a 54-aa peptide (SAP-CE) that was able to induce host-cell lysosome exocytosis and inhibit parasite internalization by 52%. This study provides novel information about the genomic organization, expression and cellular localization of SAP proteins and proposes a triggering role for extracellular SAP

Membrane rafts: a potential gateway for bacterial entry into host cells.

Science.gov (United States)

Hartlova, Anetta; Cerveny, Lukas; Hubalek, Martin; Krocova, Zuzana; Stulik, Jiri

2010-04-01

Pathogenic bacteria have developed various mechanisms to evade host immune defense systems. Invasion of pathogenic bacteria requires interaction of the pathogen with host receptors, followed by activation of signal transduction pathways and rearrangement of the cytoskeleton to facilitate bacterial entry. Numerous bacteria exploit specialized plasma membrane microdomains, commonly called membrane rafts, which are rich in cholesterol, sphingolipids and a special set of signaling molecules which allow entry to host cells and establishment of a protected niche within the host. This review focuses on the current understanding of the raft hypothesis and the means by which pathogenic bacteria subvert membrane microdomains to promote infection.

Transcriptome and microRNome of Theileria annulata Host Cells

KAUST Repository

Rchiad, Zineb

2016-06-01

Tropical Theileriosis is a parasitic disease of calves with a profound economic impact caused by Theileria annulata, an apicomplexan parasite of the genus Theileria. Transmitted by Hyalomma ticks, T. annulata infects and transforms bovine lymphocytes and macrophages into a cancer-like phenotype characterized by all six hallmarks of cancer. In the current study we investigate the transcriptional landscape of T. annulata-infected lymphocytes to define genes and miRNAs regulated by host cell transformation using next generation sequencing. We also define genes and miRNAs differentially expressed as a result of the attenuation of a T.annulata-infected macrophage cell line used as a vaccine. By comparing the transcriptional landscape of one attenuated and two transformed cell lines we identify four genes that we propose as key factors in transformation and virulence of the T. annulata host cells. We also identify miR- 126-5p as a key regulator of infected cells proliferation, adhesion, survival and invasiveness. In addition to the host cell trascriptome we studied T. annulata transcriptome and identified the role of ROS and TGF-β2 in controlling parasite gene expression. Moreover, we have used the deep parasite ssRNA-seq data to refine the available T. annulata annotation. Taken together, this study provides the full list of host cell’s genes and miRNAs transcriptionally perturbed after infection with T. annulata and after attenuation and describes genes and miRNAs never identified before as players in this type of host cell transformation. Moreover, this study provides the first database for the transcriptome of T. annulata and its host cells using next generation sequencing.

Introduced pathogens follow the invasion front of a spreading alien host

Science.gov (United States)

Ann E. Hajek; Patrick C. Tobin

2011-01-01

When an invasive species first colonizes an area, there is an interval before any host-specific natural enemies arrive at the new location. Population densities of newly invading species are low, and the spatial and temporal interactions between spreading invasive species and specific natural enemies that follow are poorly understood. We measured infection rates of two...

Cryptosporidia: Epicellular parasites embraced by the host cell membrane

Czech Academy of Sciences Publication Activity Database

Valigurová, A.; Jirků, Miloslav; Koudela, Břetislav; Gelnar, M.; Modrý, David; Šlapeta, J.

2008-01-01

Roč. 38, 8/9 (2008), s. 913-922 ISSN 0020-7519 R&D Projects: GA ČR GD524/03/H133; GA ČR GA524/05/0992; GA MŠk LC522 Institutional research plan: CEZ:AV0Z60220518 Keywords : Cryptosporidium * host cell invasion * epicellular * parasitophorous sac * ultrastructure Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 3.752, year: 2008

Plasmodium falciparum ookinetes require mosquito midgut chondroitin sulfate proteoglycans for cell invasion.

NARCIS (Netherlands)

Dinglasan, R.R.; Alaganan, A.; Ghosh, A.K.; Saito, A.; Kuppevelt, A.H.M.S.M. van; Jacobs-Lorena, M.

2007-01-01

Malaria transmission entails development of the Plasmodium parasite in its insect vector, the Anopheles mosquito. Parasite invasion of the mosquito midgut is the critical first step and involves adhesion to host epithelial cell ligands. Partial evidence suggests that midgut oligosaccharides are

Entangled fates of holobiont genomes during invasion: nested bacterial and host diversities in Caulerpa taxifolia

KAUST Repository

Arnaud-Haond, S.; Aires, T.; Candeias, R.; Teixeira, S. J. L; Duarte, Carlos M.; Valero, M.; Serrã o, E. A.

2017-01-01

Successful prevention and mitigation of biological invasions requires retracing the initial steps of introduction, as well as understanding key elements enhancing the adaptability of invasive species. We studied the genetic diversity of the green alga Caulerpa taxifolia and its associated bacterial communities in several areas around the world. The striking congruence of α and ß diversity of the algal genome and endophytic communities reveals a tight association, supporting the holobiont concept as best describing the unit of spreading and invasion. Both genomic compartments support the hypotheses of a unique accidental introduction in the Mediterranean and of multiple invasion events in Southern Australia. In addition to helping with tracing the origin of invasion, bacterial communities exhibit metabolic functions that can potentially enhance adaptability and competitiveness of the consortium they form with their host. We thus hypothesize that low genetic diversities of both host and symbiont communities may contribute to the recent regression in the Mediterranean, in contrast with the persistence of highly diverse assemblages in southern Australia. This study supports the importance of scaling up from the host to the holobiont for a comprehensive understanding of invasions. This article is protected by copyright. All rights reserved.

Entangled fates of holobiont genomes during invasion: nested bacterial and host diversities in Caulerpa taxifolia

KAUST Repository

Arnaud-Haond, S.

2017-01-30

Successful prevention and mitigation of biological invasions requires retracing the initial steps of introduction, as well as understanding key elements enhancing the adaptability of invasive species. We studied the genetic diversity of the green alga Caulerpa taxifolia and its associated bacterial communities in several areas around the world. The striking congruence of α and ß diversity of the algal genome and endophytic communities reveals a tight association, supporting the holobiont concept as best describing the unit of spreading and invasion. Both genomic compartments support the hypotheses of a unique accidental introduction in the Mediterranean and of multiple invasion events in Southern Australia. In addition to helping with tracing the origin of invasion, bacterial communities exhibit metabolic functions that can potentially enhance adaptability and competitiveness of the consortium they form with their host. We thus hypothesize that low genetic diversities of both host and symbiont communities may contribute to the recent regression in the Mediterranean, in contrast with the persistence of highly diverse assemblages in southern Australia. This study supports the importance of scaling up from the host to the holobiont for a comprehensive understanding of invasions. This article is protected by copyright. All rights reserved.

Mammal decline, linked to invasive Burmese python, shifts host use of vector mosquito towards reservoir hosts of a zoonotic disease.

Science.gov (United States)

Hoyer, Isaiah J; Blosser, Erik M; Acevedo, Carolina; Thompson, Anna Carels; Reeves, Lawrence E; Burkett-Cadena, Nathan D

2017-10-01

Invasive apex predators have profound impacts on natural communities, yet the consequences of these impacts on the transmission of zoonotic pathogens are unexplored. Collapse of large- and medium-sized mammal populations in the Florida Everglades has been linked to the invasive Burmese python, Python bivittatus Kuhl. We used historic and current data to investigate potential impacts of these community effects on contact between the reservoir hosts (certain rodents) and vectors of Everglades virus, a zoonotic mosquito-borne pathogen that circulates in southern Florida. The percentage of blood meals taken from the primary reservoir host, the hispid cotton rat, Sigmodon hispidus Say and Ord, increased dramatically (422.2%) from 1979 (14.7%) to 2016 (76.8%), while blood meals from deer, raccoons and opossums decreased by 98.2%, reflecting precipitous declines in relative abundance of these larger mammals, attributed to python predation. Overall species diversity of hosts detected in Culex cedecei blood meals from the Everglades declined by 40.2% over the same period ( H (1979) = 1.68, H (2016) = 1.01). Predictions based upon the dilution effect theory suggest that increased relative feedings upon reservoir hosts translate into increased abundance of infectious vectors, and a corresponding upsurge of Everglades virus occurrence and risk of human exposure, although this was not tested in the current study. This work constitutes the first indication that an invasive predator can increase contact between vectors and reservoirs of a human pathogen and highlights unrecognized indirect impacts of invasive predators. © 2017 The Author(s).

A human breast cell model of pre-invasive to invasive transition

Energy Technology Data Exchange (ETDEWEB)

Bissell, Mina J; Rizki, Aylin; Weaver, Valerie M.; Lee, Sun-Young; Rozenberg, Gabriela I.; Chin, Koei; Myers, Connie A.; Bascom, Jamie L.; Mott, Joni D.; Semeiks, Jeremy R.; Grate, Leslie R.; Mian, I. Saira; Borowsky, Alexander D.; Jensen, Roy A.; Idowu, Michael O.; Chen, Fanqing; Chen, David J.; Petersen, Ole W.; Gray, Joe W.; Bissell, Mina J.

2008-03-10

A crucial step in human breast cancer progression is the acquisition of invasiveness. There is a distinct lack of human cell culture models to study the transition from pre-invasive to invasive phenotype as it may occur 'spontaneously' in vivo. To delineate molecular alterations important for this transition, we isolated human breast epithelial cell lines that showed partial loss of tissue polarity in three-dimensional reconstituted-basement membrane cultures. These cells remained non-invasive; however, unlike their non-malignant counterparts, they exhibited a high propensity to acquire invasiveness through basement membrane in culture. The genomic aberrations and gene expression profiles of the cells in this model showed a high degree of similarity to primary breast tumor profiles. The xenograft tumors formed by the cell lines in three different microenvironments in nude mice displayed metaplastic phenotypes, including squamous and basal characteristics, with invasive cells exhibiting features of higher grade tumors. To find functionally significant changes in transition from pre-invasive to invasive phenotype, we performed attribute profile clustering analysis on the list of genes differentially expressed between pre-invasive and invasive cells. We found integral membrane proteins, transcription factors, kinases, transport molecules, and chemokines to be highly represented. In addition, expression of matrix metalloproteinases MMP-9,-13,-15,-17 was up regulated in the invasive cells. Using siRNA based approaches, we found these MMPs to be required for the invasive phenotype. This model provides a new tool for dissection of mechanisms by which pre-invasive breast cells could acquire invasiveness in a metaplastic context.

Molecular Mechanisms of Host Cytoskeletal Rearrangements by Shigella Invasins

Directory of Open Access Journals (Sweden)

Jun Hyuck Lee

2014-10-01

Full Text Available Pathogen-induced reorganization of the host cell cytoskeleton is a common strategy utilized in host cell invasion by many facultative intracellular bacteria, such as Shigella, Listeria, enteroinvasive E. coli and Salmonella. Shigella is an enteroinvasive intracellular pathogen that preferentially infects human epithelial cells and causes bacillary dysentery. Invasion of Shigella into intestinal epithelial cells requires extensive remodeling of the actin cytoskeleton with the aid of pathogenic effector proteins injected into the host cell by the activity of the type III secretion system. These so-called Shigella invasins, including IpaA, IpaC, IpgB1, IpgB2 and IpgD, modulate the actin-regulatory system in a concerted manner to guarantee efficient entry of the bacteria into host cells.

Influence of the host contact sequence on the outcome of competition among aspergillus flavus isolates during host tissue invasion.

Science.gov (United States)

Mehl, H L; Cotty, P J

2011-03-01

Biological control of aflatoxin contamination by Aspergillus flavus is achieved through competitive exclusion of aflatoxin producers by atoxigenic strains. Factors dictating the extent to which competitive displacement occurs during host infection are unknown. The role of initial host contact in competition between pairs of A. flavus isolates coinfecting maize kernels was examined. Isolate success during tissue invasion and reproduction was assessed by quantification of isolate-specific single nucleotide polymorphisms using pyrosequencing. Isolates were inoculated either simultaneously or 1 h apart. Increased success during competition was conferred to the first isolate to contact the host independent of that isolate's innate competitive ability. The first-isolate advantage decreased with the conidial concentration, suggesting capture of limited resources on kernel surfaces contributes to competitive exclusion. Attempts to modify access to putative attachment sites by either coating kernels with dead conidia or washing kernels with solvents did not influence the success of the first isolate, suggesting competition for limited attachment sites on kernel surfaces does not mediate first-isolate advantage. The current study is the first to demonstrate an immediate competitive advantage conferred to A. flavus isolates upon host contact and prior to either germ tube emergence or host colonization. This suggests the timing of host contact is as important to competition during disease cycles as innate competitive ability. Early dispersal to susceptible crop components may allow maintenance within A. flavus populations of genetic types with low competitive ability during host tissue invasion.

MicroRNA and protein profiles in invasive versus non-invasive oral tongue squamous cell carcinoma cells in vitro

Energy Technology Data Exchange (ETDEWEB)

Korvala, Johanna, E-mail: johanna.korvala@oulu.fi [Cancer and Translational Medicine Research Unit, University of Oulu, The Medical Research Center Oulu, Oulu University Hospital, Aapistie 5A, 90014 Oulu (Finland); Jee, Kowan [Department of Pathology, University of Turku, Turku University Hospital, Turku (Finland); Department of Pathology, Haartman Institute, University of Helsinki, Helsinki (Finland); Porkola, Emmi [Cancer and Translational Medicine Research Unit, University of Oulu, The Medical Research Center Oulu, Oulu University Hospital, Aapistie 5A, 90014 Oulu (Finland); Almangush, Alhadi [Department of Pathology, Haartman Institute, University of Helsinki, Helsinki (Finland); Mosakhani, Neda [Department of Pathology, HUSLAB, Helsinki (Finland); Bitu, Carolina [Cancer and Translational Medicine Research Unit, University of Oulu, The Medical Research Center Oulu, Oulu University Hospital, Aapistie 5A, 90014 Oulu (Finland); Cervigne, Nilva K. [Department of Oral Diagnosis, School of Dentistry, University of Campinas (UNICAMP), Av. Limeira, 901 – Bairro Areião, CEP: 13414-903 Piracicaba, São Paulo (Brazil); Department of Clinical and Pathology, Faculty of Medicine of Jundiai - FMJ, Jundiai, SP (Brazil); Zandonadi, Flávia S.; Meirelles, Gabriela V.; Leme, Adriana Franco Paes [Laboratório Nacional de Biociências, LNBio, CNPEM, Rua Giuseppe Máximo Scolfaro, 10.000, Polo II de Alta Tecnologia de Campinas, Campinas/SP, P.O.Box 6192, CEP 13083-970 Campinas, São Paulo (Brazil); Coletta, Ricardo D. [Department of Oral Diagnosis, School of Dentistry, University of Campinas (UNICAMP), Av. Limeira, 901 – Bairro Areião, CEP: 13414-903 Piracicaba, São Paulo (Brazil); and others

2017-01-01

Complex molecular pathways regulate cancer invasion. This study overviewed proteins and microRNAs (miRNAs) involved in oral tongue squamous cell carcinoma (OTSCC) invasion. The human highly aggressive OTSCC cell line HSC-3 was examined in a 3D organotypic human leiomyoma model. Non-invasive and invasive cells were laser-captured and protein expression was analyzed using mass spectrometry-based proteomics and miRNA expression by microarray. In functional studies the 3D invasion assay was replicated after silencing candidate miRNAs, miR-498 and miR-940, in invasive OTSCC cell lines (HSC-3 and SCC-15). Cell migration, proliferation and viability were also studied in the silenced cells. In HSC-3 cells, 67 proteins and 53 miRNAs showed significant fold-changes between non-invasive vs. invasive cells. Pathway enrichment analyses allocated “Focal adhesion” and “ECM-receptor interaction” as most important for invasion. Significantly, in HSC-3 cells, miR-498 silencing decreased the invasion area and miR-940 silencing reduced invasion area and depth. Viability, proliferation and migration weren’t significantly affected. In SCC-15 cells, down-regulation of miR-498 significantly reduced invasion and migration. This study shows HSC-3 specific miRNA and protein expression in invasion, and suggests that miR-498 and miR-940 affect invasion in vitro, the process being more influenced by mir-940 silencing in aggressive HSC-3 cells than in the less invasive SCC-15.

Pathogen dynamics during invasion and establishment of white-nose syndrome explain mechanisms of host persistence.

Science.gov (United States)

Frick, Winifred F; Cheng, Tina L; Langwig, Kate E; Hoyt, Joseph R; Janicki, Amanda F; Parise, Katy L; Foster, Jeffrey T; Kilpatrick, A Marm

2017-03-01

Disease dynamics during pathogen invasion and establishment determine the impacts of disease on host populations and determine the mechanisms of host persistence. Temporal progression of prevalence and infection intensity illustrate whether tolerance, resistance, reduced transmission, or demographic compensation allow initially declining populations to persist. We measured infection dynamics of the fungal pathogen Pseudogymnoascus destructans that causes white-nose syndrome in bats by estimating pathogen prevalence and load in seven bat species at 167 hibernacula over a decade as the pathogen invaded, became established, and some host populations stabilized. Fungal loads increased rapidly and prevalence rose to nearly 100% at most sites within 2 yr of invasion in six of seven species. Prevalence and loads did not decline over time despite huge reductions in colony sizes, likely due to an extensive environmental reservoir. However, there was substantial variation in fungal load among sites with persisting colonies, suggesting that both tolerance and resistance developed at different sites in the same species. In contrast, one species disappeared from hibernacula within 3 yr of pathogen invasion. Variable host responses to pathogen invasion require different management strategies to prevent disease-induced extinction and to facilitate evolution of tolerance or resistance in persisting populations. © 2016 by the Ecological Society of America.

Genes, communities & invasive species: understanding the ecological and evolutionary dynamics of host-pathogen interactions.

Science.gov (United States)

Burdon, J J; Thrall, P H; Ericson, L

2013-08-01

Reciprocal interactions between hosts and pathogens drive ecological, epidemiological and co-evolutionary trajectories, resulting in complex patterns of diversity at population, species and community levels. Recent results confirm the importance of negative frequency-dependent rather than 'arms-race' processes in the evolution of individual host-pathogen associations. At the community level, complex relationships between species abundance and diversity dampen or alter pathogen impacts. Invasive pathogens challenge these controls reflecting the earliest stages of evolutionary associations (akin to arms-race) where disease effects may be so great that they overwhelm the host's and community's ability to respond. Viewing these different stabilization/destabilization phases as a continuum provides a valuable perspective to assessment of the role of genetics and ecology in the dynamics of both natural and invasive host-pathogen associations. Copyright © 2013 Elsevier Ltd. All rights reserved.

Complex interactions among host pines and fungi vectored by an invasive bark beetle

Science.gov (United States)

Min Lu; Michael J. Wingfield; Nancy E. Gillette; Sylvia R. Mori; Jian-Hua Sun

2010-01-01

Recent studies have investigated the relationships between pairs or groups of exotic species to illustrate invasive mechanisms, but most have focused on interactions at a single trophic level.Here, we conducted pathogenicity tests, analyses of host volatiles and fungal growth tests to elucidate an intricate network of interactions between the host...

Mechanisms of cellular invasion by intracellular parasites.

Science.gov (United States)

Walker, Dawn M; Oghumu, Steve; Gupta, Gaurav; McGwire, Bradford S; Drew, Mark E; Satoskar, Abhay R

2014-04-01

Numerous disease-causing parasites must invade host cells in order to prosper. Collectively, such pathogens are responsible for a staggering amount of human sickness and death throughout the world. Leishmaniasis, Chagas disease, toxoplasmosis, and malaria are neglected diseases and therefore are linked to socio-economical and geographical factors, affecting well-over half the world's population. Such obligate intracellular parasites have co-evolved with humans to establish a complexity of specific molecular parasite-host cell interactions, forming the basis of the parasite's cellular tropism. They make use of such interactions to invade host cells as a means to migrate through various tissues, to evade the host immune system, and to undergo intracellular replication. These cellular migration and invasion events are absolutely essential for the completion of the lifecycles of these parasites and lead to their for disease pathogenesis. This review is an overview of the molecular mechanisms of protozoan parasite invasion of host cells and discussion of therapeutic strategies, which could be developed by targeting these invasion pathways. Specifically, we focus on four species of protozoan parasites Leishmania, Trypanosoma cruzi, Plasmodium, and Toxoplasma, which are responsible for significant morbidity and mortality.

Microsporidia infection impacts the host cell's cycle and reduces host cell apoptosis

Science.gov (United States)

Higes, Mariano; Sagastume, Soledad; Juarranz, Ángeles; Dias-Almeida, Joyce; Budge, Giles E.; Meana, Aránzazu; Boonham, Neil

2017-01-01

Intracellular parasites can alter the cellular machinery of host cells to create a safe haven for their survival. In this regard, microsporidia are obligate intracellular fungal parasites with extremely reduced genomes and hence, they are strongly dependent on their host for energy and resources. To date, there are few studies into host cell manipulation by microsporidia, most of which have focused on morphological aspects. The microsporidia Nosema apis and Nosema ceranae are worldwide parasites of honey bees, infecting their ventricular epithelial cells. In this work, quantitative gene expression and histology were studied to investigate how these two parasites manipulate their host’s cells at the molecular level. Both these microsporidia provoke infection-induced regulation of genes involved in apoptosis and the cell cycle. The up-regulation of buffy (which encodes a pro-survival protein) and BIRC5 (belonging to the Inhibitor Apoptosis protein family) was observed after infection, shedding light on the pathways that these pathogens use to inhibit host cell apoptosis. Curiously, different routes related to cell cycle were modified after infection by each microsporidia. In the case of N. apis, cyclin B1, dacapo and E2F2 were up-regulated, whereas only cyclin E was up-regulated by N. ceranae, in both cases promoting the G1/S phase transition. This is the first report describing molecular pathways related to parasite-host interactions that are probably intended to ensure the parasite’s survival within the cell. PMID:28152065

Ebola virus host cell entry.

Science.gov (United States)

Sakurai, Yasuteru

2015-01-01

Ebola virus is an enveloped virus with filamentous structure and causes a severe hemorrhagic fever in human and nonhuman primates. Host cell entry is the first essential step in the viral life cycle, which has been extensively studied as one of the therapeutic targets. A virus factor of cell entry is a surface glycoprotein (GP), which is an only essential viral protein in the step, as well as the unique particle structure. The virus also interacts with a lot of host factors to successfully enter host cells. Ebola virus at first binds to cell surface proteins and internalizes into cells, followed by trafficking through endosomal vesicles to intracellular acidic compartments. There, host proteases process GPs, which can interact with an intracellular receptor. Then, under an appropriate circumstance, viral and endosomal membranes are fused, which is enhanced by major structural changes of GPs, to complete host cell entry. Recently the basic research of Ebola virus infection mechanism has markedly progressed, largely contributed by identification of host factors and detailed structural analyses of GPs. This article highlights the mechanism of Ebola virus host cell entry, including recent findings.

New Parameters to Quantitatively Express the Invasiveness of Bacterial Strains from Implant-Related Orthopaedic Infections into Osteoblast Cells.

Science.gov (United States)

Campoccia, Davide; Montanaro, Lucio; Ravaioli, Stefano; Cangini, Ilaria; Testoni, Francesca; Visai, Livia; Arciola, Carla Renata

2018-04-03

Complete eradication of bacterial infections is often a challenging task, especially in presence of prosthetic devices. Invasion of non-phagocytic host cells appears to be a critical mechanism of microbial persistence in host tissues. Hidden within host cells, bacteria elude host defences and antibiotic treatments that are intracellularly inactive. The intracellular invasiveness of bacteria is generally measured by conventional gentamicin protection assays. The efficiency of invasion, however, markedly differs across bacterial species and adjustments to the titre of the microbial inocula used in the assays are often needed to enumerate intracellular bacteria. Such changes affect the standardisation of the method and hamper a direct comparison of bacteria on a same scale. This study aims at investigating the precise relation between inoculum, in terms of multiplicity of infection (MOI), and internalised bacteria. The investigation included nine Staphylococcus aureus , seven Staphylococcus epidermidis , five Staphylococcus lugdunensis and two Enterococcus faecalis clinical strains, which are co-cultured with MG63 human osteoblasts. Unprecedented insights are offered on the relations existing between MOI, number of internalised bacteria and per cent of internalised bacteria. New parameters are identified that are of potential use for qualifying the efficiency of internalization and compare the behaviour of bacterial strains.

New Parameters to Quantitatively Express the Invasiveness of Bacterial Strains from Implant-Related Orthopaedic Infections into Osteoblast Cells

Directory of Open Access Journals (Sweden)

Davide Campoccia

2018-04-01

Full Text Available Complete eradication of bacterial infections is often a challenging task, especially in presence of prosthetic devices. Invasion of non-phagocytic host cells appears to be a critical mechanism of microbial persistence in host tissues. Hidden within host cells, bacteria elude host defences and antibiotic treatments that are intracellularly inactive. The intracellular invasiveness of bacteria is generally measured by conventional gentamicin protection assays. The efficiency of invasion, however, markedly differs across bacterial species and adjustments to the titre of the microbial inocula used in the assays are often needed to enumerate intracellular bacteria. Such changes affect the standardisation of the method and hamper a direct comparison of bacteria on a same scale. This study aims at investigating the precise relation between inoculum, in terms of multiplicity of infection (MOI, and internalised bacteria. The investigation included nine Staphylococcus aureus, seven Staphylococcus epidermidis, five Staphylococcus lugdunensis and two Enterococcus faecalis clinical strains, which are co-cultured with MG63 human osteoblasts. Unprecedented insights are offered on the relations existing between MOI, number of internalised bacteria and per cent of internalised bacteria. New parameters are identified that are of potential use for qualifying the efficiency of internalization and compare the behaviour of bacterial strains.

Density threshold for Mopeia virus invasion and persistence in its host Mastomys natalensis

DEFF Research Database (Denmark)

Goyens, J.; Reijniers, J.; Borremans, B.

2013-01-01

. We developed a spatially explicit and individual-based SEIR model of Mopeia virus in multimammate mice Mastomys natalensis. This is an interesting model system for studying abundance thresholds because the host is the most common African rodent, populations fluctuate considerably and the virus...... is closely related to Lassa virus but non-pathogenic to humans so can be studied safely in the field. The simulations show that, while host density clearly is important, sharp thresholds are only to be expected for persistence (and not for invasion), since at short time-spans (as during invasion...

The Arf GTPase-activating protein family is exploited by Salmonella enterica serovar Typhimurium to invade nonphagocytic host cells.

Science.gov (United States)

Davidson, Anthony C; Humphreys, Daniel; Brooks, Andrew B E; Hume, Peter J; Koronakis, Vassilis

2015-02-10

To establish intracellular infections, Salmonella bacteria trigger host cell membrane ruffling and invasion by subverting cellular Arf guanine nucleotide exchange factors (GEFs) that activate Arf1 and Arf6 GTPases by promoting GTP binding. A family of cellular Arf GTPase-activating proteins (GAPs) can downregulate Arf signaling by stimulating GTP hydrolysis, but whether they do this during infection is unknown. Here, we uncovered a remarkable role for distinct Arf GAP family members in Salmonella invasion. The Arf6 GAPs ACAP1 and ADAP1 and the Arf1 GAP ASAP1 localized at Salmonella-induced ruffles, which was not the case for the plasma membrane-localized Arf6 GAPs ARAP3 and GIT1 or the Golgi-associated Arf1 GAP1. Surprisingly, we found that loss of ACAP1, ADAP1, or ASAP1 impaired Salmonella invasion, revealing that GAPs cannot be considered mere terminators of cytoskeleton remodeling. Salmonella invasion was restored in Arf GAP-depleted cells by expressing fast-cycling Arf derivatives, demonstrating that Arf GTP/GDP cycles facilitate Salmonella invasion. Consistent with this view, both constitutively active and dominant-negative Arf derivatives that cannot undergo GTP/GDP cycles inhibited invasion. Furthermore, we demonstrated that Arf GEFs and GAPs colocalize at invading Salmonella and collaborate to drive Arf1-dependent pathogen invasion. This study revealed that Salmonella bacteria exploit a remarkable interplay between Arf GEFs and GAPs to direct cycles of Arf GTPase activation and inactivation. These cycles drive Salmonella cytoskeleton remodeling and enable intracellular infections. To initiate infections, the Salmonella bacterial pathogen remodels the mammalian actin cytoskeleton and invades host cells by subverting host Arf GEFs that activate Arf1 and Arf6 GTPases. Cellular Arf GAPs deactivate Arf GTPases and negatively regulate cell processes, but whether they target Arfs during infection is unknown. Here, we uncovered an important role for the Arf GAP

Invasion of erythrocytes by Babesia bovis

NARCIS (Netherlands)

Gaffar, Fasila Razzia

2004-01-01

In this thesis we investigated the invasion of erythrocytes taking place during the asexual erythrocytic blood stage of the apicomplexan parasites Babesia bovis parasite. Host cell invasion by apicomplexan parasites is a complex process requiring multiple receptor-ligand interactions, involving

Falciparum malaria infection with invasive pulmonary aspergillosis in immunocompetent host – case report

Science.gov (United States)

Andriyani, Y.

2018-03-01

Invasive pulmonary aspergillosis is an extraordinary rare in the immunocompetent host. Falciparum malaria contributes to high morbidity and mortality of malaria infection cases in the world. The impairments of both humoral and cellular immunity could be the reason of invasive pulmonary aspergillosis in falciparum malaria infection. Forty-nine years old patient came with fever, jaundice, pain in the right abdomen, after visiting a remote area in Africa about one month before admission. Blood films and rapid test were positive for Plasmodium falciparum. After malaria therapy in five days, consciousness was altered into somnolence and intubated with respiratory deterioration. Invasive pulmonary aspergillosis after falciparum malaria infection is life-threatening. There should be awareness of physicians of invasive pulmonary aspergillosis in falciparum malaria infection.

Phenotypic interactions between tree hosts and invasive forest pathogens in the light of globalization and climate change.

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Stenlid, Jan; Oliva, Jonàs

2016-12-05

Invasive pathogens can cause considerable damage to forest ecosystems. Lack of coevolution is generally thought to enable invasive pathogens to bypass the defence and/or recognition systems in the host. Although mostly true, this argument fails to predict intermittent outcomes in space and time, underlining the need to include the roles of the environment and the phenotype in host-pathogen interactions when predicting disease impacts. We emphasize the need to consider host-tree imbalances from a phenotypic perspective, considering the lack of coevolutionary and evolutionary history with the pathogen and the environment, respectively. We describe how phenotypic plasticity and plastic responses to environmental shifts may become maladaptive when hosts are faced with novel pathogens. The lack of host-pathogen and environmental coevolution are aligned with two global processes currently driving forest damage: globalization and climate change, respectively. We suggest that globalization and climate change act synergistically, increasing the chances of both genotypic and phenotypic imbalances. Short moves on the same continent are more likely to be in balance than if the move is from another part of the world. We use Gremmeniella abietina outbreaks in Sweden to exemplify how host-pathogen phenotypic interactions can help to predict the impacts of specific invasive and emergent diseases.This article is part of the themed issue 'Tackling emerging fungal threats to animal health, food security and ecosystem resilience'. © 2016 The Author(s).

Host heterogeneity influences the impact of a non-native disease invasion on populations of a foundation tree species

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Jules, Erik S.; Carroll, Allyson L.; Garcia, Andrea M.; Steenbock, Christopher M.; Kauffman, Matthew J.

2014-01-01

Invasive pathogens are becoming increasingly important in forested ecosystems, yet they are often difficult to study because of their rapid transmission. The rate and extent of pathogen spread are thought to be partially controlled by variation in host characteristics, such as when host size and location influence susceptibility. Few host-pathogen systems, however, have been used to test this prediction. We used Port Orford cedar (Chamaecyparis lawsoniana), a foundation tree species in riparian areas of California and Oregon (USA), and the invasive oomycete Phytophthora lateralis to assess pathogen impacts and the role of host characteristics on invasion. Across three streams that had been infected for 13–18 years by P. lateralis, we mapped 2241 trees and determined whether they had been infected using dendrochronology. The infection probability of trees was governed by host size (diameter at breast height [DBH]) and geomorphic position (e.g., active channel, stream bank, floodplain, etc.) similarly across streams. For instance, only 23% of trees <20 cm DBH were infected, while 69% of trees ≥20 cm DBH were infected. Presumably, because spores of P. lateralis are transported downstream in water, they are more likely to encounter well-developed root systems of larger trees. Also because of this water-transport of spores, differences in infection probability were found across the geomorphic positions: 59% of cedar in the active channel and the stream bank (combined) were infected, while 23% of trees found on higher geomorphic types were infected. Overall, 32% of cedar had been infected across the three streams. However, 63% of the total cedar basal area had been killed, because the greatest number of trees, and the largest trees, were found in the most susceptible positions. In the active channel and stream bank, 91% of the basal area was infected, while 46% was infected across higher geomorphic positions. The invasion of Port Orford cedar populations by

Regulation of the actin cytoskeleton in Helicobacter pylori-induced migration and invasive growth of gastric epithelial cells

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Rieder Gabriele

2011-11-01

Full Text Available Abstract Dynamic rearrangement of the actin cytoskeleton is a significant hallmark of Helicobacter pylori (H. pylori infected gastric epithelial cells leading to cell migration and invasive growth. Considering the cellular mechanisms, the type IV secretion system (T4SS and the effector protein cytotoxin-associated gene A (CagA of H. pylori are well-studied initiators of distinct signal transduction pathways in host cells targeting kinases, adaptor proteins, GTPases, actin binding and other proteins involved in the regulation of the actin lattice. In this review, we summarize recent findings of how H. pylori functionally interacts with the complex signaling network that controls the actin cytoskeleton of motile and invasive gastric epithelial cells.

A Mena invasion isoform potentiates EGF-induced carcinoma cell invasion and metastasis.

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Philippar, Ulrike; Roussos, Evanthia T; Oser, Matthew; Yamaguchi, Hideki; Kim, Hyung-Do; Giampieri, Silvia; Wang, Yarong; Goswami, Sumanta; Wyckoff, Jeffrey B; Lauffenburger, Douglas A; Sahai, Erik; Condeelis, John S; Gertler, Frank B

2008-12-01

The spread of cancer during metastatic disease requires that tumor cells subvert normal regulatory networks governing cell motility to invade surrounding tissues and migrate toward blood and lymphatic vessels. Enabled (Ena)/vasodilator-stimulated phosphoprotein (VASP) proteins regulate cell motility by controlling the geometry of assembling actin networks. Mena, an Ena/VASP protein, is upregulated in the invasive subpopulation of breast cancer cells. In addition, Mena is alternately spliced to produce an invasion isoform, Mena(INV). Here we show that Mena and Mena(INV) promote carcinoma cell motility and invasiveness in vivo and in vitro, and increase lung metastasis. Mena and Mena(INV) potentiate epidermal growth factor (EGF)-induced membrane protrusion and increase the matrix degradation activity of tumor cells. Interestingly, Mena(INV) is significantly more effective than Mena in driving metastases and sensitizing cells to EGF-dependent invasion and protrusion. Upregulation of Mena(INV) could therefore enable tumor cells to invade in response to otherwise benign EGF stimulus levels.

Porphyromonas gingivalis as a Model Organism for Assessing Interaction of Anaerobic Bacteria with Host Cells.

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Wunsch, Christopher M; Lewis, Janina P

2015-12-17

Anaerobic bacteria far outnumber aerobes in many human niches such as the gut, mouth, and vagina. Furthermore, anaerobic infections are common and frequently of indigenous origin. The ability of some anaerobic pathogens to invade human cells gives them adaptive measures to escape innate immunity as well as to modulate host cell behavior. However, ensuring that the anaerobic bacteria are live during experimental investigation of the events may pose challenges. Porphyromonas gingivalis, a Gram-negative anaerobe, is capable of invading a variety of eukaryotic non-phagocytic cells. This article outlines how to successfully culture and assess the ability of P. gingivalis to invade human umbilical vein endothelial cells (HUVECs). Two protocols were developed: one to measure bacteria that can successfully invade and survive within the host, and the other to visualize bacteria interacting with host cells. These techniques necessitate the use of an anaerobic chamber to supply P. gingivalis with an anaerobic environment for optimal growth. The first protocol is based on the antibiotic protection assay, which is largely used to study the invasion of host cells by bacteria. However, the antibiotic protection assay is limited; only intracellular bacteria that are culturable following antibiotic treatment and host cell lysis are measured. To assess all bacteria interacting with host cells, both live and dead, we developed a protocol that uses fluorescent microscopy to examine host-pathogen interaction. Bacteria are fluorescently labeled with 2',7'-Bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein acetoxymethyl ester (BCECF-AM) and used to infect eukaryotic cells under anaerobic conditions. Following fixing with paraformaldehyde and permeabilization with 0.2% Triton X-100, host cells are labeled with TRITC phalloidin and DAPI to label the cell cytoskeleton and nucleus, respectively. Multiple images taken at different focal points (Z-stack) are obtained for temporal

Staphylococcus aureus host cell invasion and virulence in sepsis is facilitated by the multiple repeats within FnBPA.

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Andrew M Edwards

2010-06-01

Full Text Available Entry of Staphylococcus aureus into the bloodstream can lead to metastatic abscess formation and infective endocarditis. Crucial to the development of both these conditions is the interaction of S. aureus with endothelial cells. In vivo and in vitro studies have shown that the staphylococcal invasin FnBPA triggers bacterial invasion of endothelial cells via a process that involves fibronectin (Fn bridging to alpha(5beta(1 integrins. The Fn-binding region of FnBPA usually contains 11 non-identical repeats (FnBRs with differing affinities for Fn, which facilitate the binding of multiple Fn molecules and may promote integrin clustering. We thus hypothesized that multiple repeats are necessary to trigger the invasion of endothelial cells by S. aureus. To test this we constructed variants of fnbA containing various combinations of FnBRs. In vitro assays revealed that endothelial cell invasion can be facilitated by a single high-affinity, but not low-affinity FnBR. Studies using a nisin-inducible system that controlled surface expression of FnBPA revealed that variants encoding fewer FnBRs required higher levels of surface expression to mediate invasion. High expression levels of FnBPA bearing a single low affinity FnBR bound Fn but did not invade, suggesting that FnBPA affinity for Fn is crucial for triggering internalization. In addition, multiple FnBRs increased the speed of internalization, as did higher expression levels of FnBPA, without altering the uptake mechanism. The relevance of these findings to pathogenesis was demonstrated using a murine sepsis model, which showed that multiple FnBRs were required for virulence. In conclusion, multiple FnBRs within FnBPA facilitate efficient Fn adhesion, trigger rapid bacterial uptake and are required for pathogenesis.

Histone methylation-mediated silencing of miR-139 enhances invasion of non-small-cell lung cancer

International Nuclear Information System (INIS)

Watanabe, Kousuke; Amano, Yosuke; Ishikawa, Rie; Sunohara, Mitsuhiro; Kage, Hidenori; Ichinose, Junji; Sano, Atsushi; Nakajima, Jun; Fukayama, Masashi; Yatomi, Yutaka; Nagase, Takahide; Ohishi, Nobuya; Takai, Daiya

2015-01-01

MicroRNA expression is frequently altered in human cancers, and some microRNAs act as oncogenes or tumor suppressors. MiR-139-5p (denoted thereafter as miR-139) has recently been reported to function as a tumor suppressor in several types of human cancer (hepatocellular carcinoma, colorectal cancer, breast cancer, and gastric cancer), but its function in non-small-cell lung cancer (NSCLC) and the mechanism of its suppression have not been studied in detail. MiR-139 was suppressed frequently in primary NSCLCs. MiR-139 is located within the intron of PDE2A and its expression was significantly correlated with the expression of PDE2A. A chromatin immunoprecipitation assay revealed that miR-139 was epigenetically silenced by histone H3 lysine 27 trimethylation (H3K27me3) of its host gene PDE2A and this process was independent of promoter DNA methylation. Pharmacological inhibition of both histone methylation and deacetylation-induced miR-139 with its host gene PDE2A. Ectopic expression of miR-139 in lung cancer cell lines did not affect the proliferation nor the migration but significantly suppressed the invasion through the extracellular matrix. In primary NSCLCs, decreased expression of miR-139 was significantly associated with distant lymph node metastasis and histological invasiveness (lymphatic invasion and vascular invasion) on both univariate and multivariate analyses. Collectively, these results suggest that H3K27me3-mediated silencing of miR-139 enhances an invasive and metastatic phenotype of NSCLC

A novel mechanism of bacterial toxin transfer within host blood cell-derived microvesicles.

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Anne-lie Ståhl

2015-02-01

Full Text Available Shiga toxin (Stx is the main virulence factor of enterohemorrhagic Escherichia coli, which are non-invasive strains that can lead to hemolytic uremic syndrome (HUS, associated with renal failure and death. Although bacteremia does not occur, bacterial virulence factors gain access to the circulation and are thereafter presumed to cause target organ damage. Stx was previously shown to circulate bound to blood cells but the mechanism by which it would potentially transfer to target organ cells has not been elucidated. Here we show that blood cell-derived microvesicles, shed during HUS, contain Stx and are found within patient renal cortical cells. The finding was reproduced in mice infected with Stx-producing Escherichia coli exhibiting Stx-containing blood cell-derived microvesicles in the circulation that reached the kidney where they were transferred into glomerular and peritubular capillary endothelial cells and further through their basement membranes followed by podocytes and tubular epithelial cells, respectively. In vitro studies demonstrated that blood cell-derived microvesicles containing Stx undergo endocytosis in glomerular endothelial cells leading to cell death secondary to inhibited protein synthesis. This study demonstrates a novel virulence mechanism whereby bacterial toxin is transferred within host blood cell-derived microvesicles in which it may evade the host immune system.

The civRT operon is important for Campylobacter jejuni strain 81-176 host cell interactions through regulation of the formate dehydrogenase operon

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C. jejuni colonizes the intestinal mucosa, and the severity of disease in different strains is correlated with host cell interaction and invasion. A microarray screen to identify genes differentially regulated during C. jejuni interaction with tissue culture cells revealed the up-regulation of a two...

Construction of a new shuttle vector for DNA delivery into mammalian cells using non-invasive Lactococcus lactis.

Science.gov (United States)

Yagnik, Bhrugu; Padh, Harish; Desai, Priti

2016-04-01

Use of food grade Lactococcus lactis (L. lactis) is fast emerging as a safe alternative for delivery of DNA vaccine. To attain efficient DNA delivery, L. lactis, a non-invasive bacterium is converted to invasive strain either by expressing proteins like Internalin A (InlA) or Fibronectin binding protein A (FnBPA) or through chemical treatments. However the safety status of invasive L. lactis is questionable. In the present report, we have shown that non-invasive L. lactis efficiently delivered the newly constructed reporter plasmid pPERDBY to mammalian cells without any chemical enhancers. The salient features of the vector are; I) Ability to replicate in two different hosts; Escherichia coli (E. coli) and Lactic Acid Bacteria (LAB), II) One of the smallest reporter plasmid for DNA vaccine, III) Enhanced Green Fluorescence Protein (EGFP) linked to Multiple Cloning Site (MCS), IV) Immunostimulatory CpG motifs functioning as an adjuvant. Expression of EGFP in pPERDBY transfected CHO-K1 and Caco-2 cells demonstrates its functionality. Non-invasive r-L. lactis was found efficient in delivering pPERDBY to Caco-2 cells. The in vitro data presented in this article supports the hypothesis that in the absence of invasive proteins or relevant chemical treatment, L. lactis was found efficient in delivering DNA to mammalian cells. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Ultrastructural characteristics of nurse cell-larva complex of four species of Trichinella in several hosts

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Sacchi L.

2001-06-01

Full Text Available The nurse cell-larva complex of nematodes of the genus Trichinella plays an Important role in the survival of the larva in decaying muscles, frequently favouring the transmission of the parasite in extreme environmental conditions. The ultrastructure of the nurse cell-larva complex in muscles from different hosts infected with T. nativa (a walrus and a polar bear, T. spiralis (horses and humans, T. pseudospiralis (a laboratory mouse and T. papuae (a laboratory mouse were examined. Analysis with transmission electron microscope showed that the typical nurse cell structure was present in all examined samples, irrespective of the species of larva, of the presence of a collagen capsule, of the age of infection and of the host species, suggesting that there exists a molecular mechanism that in the first stage of larva invasion is similar for encapsulated and non-encapsulated species.

Parasite invasion following host reintroduction: a case study of Yellowstone's wolves.

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Almberg, Emily S; Cross, Paul C; Dobson, Andrew P; Smith, Douglas W; Hudson, Peter J

2012-10-19

Wildlife reintroductions select or treat individuals for good health with the expectation that these individuals will fare better than infected animals. However, these individuals, new to their environment, may also be particularly susceptible to circulating infections and this may result in high morbidity and mortality, potentially jeopardizing the goals of recovery. Here, using the reintroduction of the grey wolf (Canis lupus) into Yellowstone National Park as a case study, we address the question of how parasites invade a reintroduced population and consider the impact of these invasions on population performance. We find that several viral parasites rapidly invaded the population inside the park, likely via spillover from resident canid species, and we contrast these with the slower invasion of sarcoptic mange, caused by the mite Sarcoptes scabiei. The spatio-temporal patterns of mange invasion were largely consistent with patterns of host connectivity and density, and we demonstrate that the area of highest resource quality, supporting the greatest density of wolves, is also the region that appears most susceptible to repeated disease invasion and parasite-induced declines. The success of wolf reintroduction appears not to have been jeopardized by infectious disease, but now shows signs of regulation or limitation modulated by parasites.

Parasite invasion following host reintroduction: a case of Yellowstone’s wolves

Science.gov (United States)

Cross, Paul C.; Almberg, Emily S.; Dobson, Andrew P.; Smith, Douglas W.; Hudson, Peter J.

2012-01-01

Wildlife reintroductions select or treat individuals for good health with the expectation that these individuals will fare better than infected animals. However, these individuals, new to their environment, may also be particularly susceptible to circulating infections and this may result in high morbidity and mortality, potentially jeopardizing the goals of recovery. Here, using the reintroduction of the grey wolf (Canis lupus) into Yellowstone National Park as a case study, we address the question of how parasites invade a reintroduced population and consider the impact of these invasions on population performance. We find that several viral parasites rapidly invaded the population inside the park, likely via spillover from resident canid species, and we contrast these with the slower invasion of sarcoptic mange, caused by the mite Sarcoptes scabiei. The spatio-temporal patterns of mange invasion were largely consistent with patterns of host connectivity and density, and we demonstrate that the area of highest resource quality, supporting the greatest density of wolves, is also the region that appears most susceptible to repeated disease invasion and parasite-induced declines. The success of wolf reintroduction appears not to have been jeopardized by infectious disease, but now shows signs of regulation or limitation modulated by parasites.

TGFβ loss activates ADAMTS-1-mediated EGF-dependent invasion in a model of esophageal cell invasion

Energy Technology Data Exchange (ETDEWEB)

Le Bras, Grégoire F.; Taylor, Chase; Koumangoye, Rainelli B. [Department of Surgery, Vanderbilt University, Nashville, TN (United States); Revetta, Frank [Department of Pathology, Vanderbilt University, Nashville, TN (United States); Loomans, Holli A. [Department of Cancer Biology, Vanderbilt University, Nashville, TN (United States); Andl, Claudia D., E-mail: claudia.andl@vanderbilt.edu [Department of Surgery, Vanderbilt University, Nashville, TN (United States); Department of Cancer Biology, Vanderbilt University, Nashville, TN (United States); Department of Vanderbilt Ingram Cancer Center, Vanderbilt University, Nashville, TN (United States)

2015-01-01

The TGFβ signaling pathway is essential to epithelial homeostasis and is often inhibited during progression of esophageal squamous cell carcinoma. Recently, an important role for TGFβ signaling has been described in the crosstalk between epithelial and stromal cells regulating squamous tumor cell invasion in mouse models of head-and-neck squamous cell carcinoma (HNSCC). Loss of TGFβ signaling, in either compartment, leads to HNSCC however, the mechanisms involved are not well understood. Using organotypic reconstruct cultures (OTC) to model the interaction between epithelial and stromal cells that occur in dysplastic lesions, we show that loss of TGFβ signaling promotes an invasive phenotype in both fibroblast and epithelial compartments. Employing immortalized esophageal keratinocytes established to reproduce common mutations of esophageal squamous cell carcinoma, we show that treatment of OTC with inhibitors of TGFβ signaling (A83-01 or SB431542) enhances invasion of epithelial cells into a fibroblast-embedded Matrigel/collagen I matrix. Invasion induced by A83-01 is independent of proliferation but relies on protease activity and expression of ADAMTS-1 and can be altered by matrix density. This invasion was associated with increased expression of pro-inflammatory cytokines, IL1 and EGFR ligands HB-EGF and TGFα. Altering EGF signaling prevented or induced epithelial cell invasion in this model. Loss of expression of the TGFβ target gene ROBO1 suggested that chemorepulsion may regulate keratinocyte invasion. Taken together, our data show increased invasion through inhibition of TGFβ signaling altered epithelial-fibroblasts interactions, repressing markers of activated fibroblasts, and altering integrin-fibronectin interactions. These results suggest that inhibition of TGFβ signaling modulates an array of pathways that combined promote multiple aspects of tumor invasion. - Highlights: • Chemical inhibition of TGFβ signaling advances collective invasion

Membrane-type-3 matrix metalloproteinase (MT3-MMP functions as a matrix composition-dependent effector of melanoma cell invasion.

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Olga Tatti

Full Text Available In primary human melanoma, the membrane-type matrix metalloproteinase, MT3-MMP, is overexpressed in the most aggressive nodular-type tumors. Unlike MT1-MMP and MT2-MMP, which promote cell invasion through basement membranes and collagen type I-rich tissues, the function of MT3-MMP in tumor progression remains unclear. Here, we demonstrate that MT3-MMP inhibits MT1-MMP-driven melanoma cell invasion in three-dimensional collagen, while yielding an altered, yet MT1-MMP-dependent, form of expansive growth behavior that phenocopies the formation of nodular cell colonies. In melanoma cell lines originating from advanced primary or metastatic lesions, endogenous MT3-MMP expression was associated with limited collagen-invasive potential. In the cell lines with highest MT3-MMP expression relative to MT1-MMP, collagen-invasive activity was increased following stable MT3-MMP gene silencing. Consistently, MT3-MMP overexpression in cells derived from less advanced superficially spreading melanoma lesions, or in the MT3-MMP knockdown cells, reduced MT1-MMP-dependent collagen invasion. Rather than altering MT1-MMP transcription, MT3-MMP interacted with MT1-MMP in membrane complexes and reduced its cell surface expression. By contrast, as a potent fibrinolytic enzyme, MT3-MMP induced efficient invasion of the cells in fibrin, a provisional matrix component frequently found at tumor-host tissue interfaces and perivascular spaces of melanoma. Since MT3-MMP was significantly upregulated in biopsies of human melanoma metastases, these results identify MT3-MMP as a matrix-dependent modifier of the invasive tumor cell functions during melanoma progression.

Host Factors and Biomarkers Associated with Poor Outcomes in Adults with Invasive Pneumococcal Disease.

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Shigeo Hanada

Full Text Available Invasive pneumococcal disease (IPD causes considerable morbidity and mortality. We aimed to identify host factors and biomarkers associated with poor outcomes in adult patients with IPD in Japan, which has a rapidly-aging population.In a large-scale surveillance study of 506 Japanese adults with IPD, we investigated the role of host factors, disease severity, biomarkers based on clinical laboratory data, treatment regimens, and bacterial factors on 28-day mortality.Overall mortality was 24.1%, and the mortality rate increased from 10.0% in patients aged ˂50 years to 33.1% in patients aged ≥80 years. Disease severity also increased 28-day mortality, from 12.5% among patients with bacteraemia without sepsis to 35.0% in patients with severe sepsis and 56.9% with septic shock. The death rate within 48 hours after admission was high at 54.9%. Risk factors for mortality identified by multivariate analysis were as follows: white blood cell (WBC count <4000 cells/μL (odds ratio [OR], 6.9; 95% confidence interval [CI], 3.7-12.8, p < .001; age ≥80 years (OR, 6.5; 95% CI, 2.0-21.6, p = .002; serum creatinine ≥2.0 mg/dL (OR, 4.5; 95% CI, 2.5-8.1, p < .001; underlying liver disease (OR, 3.5; 95% CI, 1.6-7.8, p = .002; mechanical ventilation (OR, 3.0; 95% CI, 1.7-5.6, p < .001; and lactate dehydrogenase ≥300 IU/L (OR, 2.4; 95% CI, 1.4-4.0, p = .001. Pneumococcal serotype and drug resistance were not associated with poor outcomes.Host factors, disease severity, and biomarkers, especially WBC counts and serum creatinine, were more important determinants of mortality than bacterial factors.

Vinculin contributes to Cell Invasion by Regulating Contractile Activation

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Mierke, Claudia Tanja

2008-07-01

Vinculin is a component of the focal adhesion complex and is described as a mechano-coupling protein connecting the integrin receptor and the actin cytoskeleton. Vinculin knock-out (k.o.) cells (vin-/-) displayed increased migration on a 2-D collagen- or fibronectin-coated substrate compared to wildtype cells, but the role of vinculin in cell migration through a 3-D connective tissue is unknown. We determined the invasiveness of established tumor cell lines using a 3-D collagen invasion assay. Gene expression analysis of 4 invasive and 4 non-invasive tumor cell lines revealed that vinculin expression was significantly increased in invasive tumor cell lines. To analyze the mechanisms by which vinculin increased cell invasion in a 3-D gel, we studied mouse embryonic fibroblasts wildtype and vin-/- cells. Wildtype cells were 3-fold more invasive compared vin-/- cells. We hypothesized that the ability to generate sufficient traction forces is a prerequisite for tumor cell migration in a 3-D connective tissue matrix. Using traction microscopy, we found that wildtype exerted 3-fold higher tractions on fibronectin-coated polyacrylamide gels compared to vin-/- cells. These results show that vinculin controls two fundamental functions that lead to opposite effects on cell migration in a 2-D vs. a 3-D environment: On the one hand, vinculin stabilizes the focal adhesions (mechano-coupling function) and thereby reduces motility in 2-D. On the other hand, vinculin is also a potent activator of traction generation (mechano-regulating function) that is important for cell invasion in a 3-D environment.

Fatty Acid Composition of Novel Host Jack Pine Do Not Prevent Host Acceptance and Colonization by the Invasive Mountain Pine Beetle and Its Symbiotic Fungus

Science.gov (United States)

Ishangulyyeva, Guncha; Najar, Ahmed; Curtis, Jonathan M.

2016-01-01

Fatty acids are major components of plant lipids and can affect growth and development of insect herbivores. Despite a large literature examining the roles of fatty acids in conifers, relatively few studies have tested the effects of fatty acids on insect herbivores and their microbial symbionts. Particularly, whether fatty acids can affect the suitability of conifers for insect herbivores has never been studied before. Thus, we evaluated if composition of fatty acids impede or facilitate colonization of jack pine (Pinus banksiana) by the invasive mountain pine beetle (Dendroctonus ponderosae) and its symbiotic fungus (Grosmannia clavigera). This is the first study to examine the effects of tree fatty acids on any bark beetle species and its symbiotic fungus. In a novel bioassay, we found that plant tissues (hosts and non-host) amended with synthetic fatty acids at concentrations representative of jack pine were compatible with beetle larvae. Likewise, G. clavigera grew in media amended with lipid fractions or synthetic fatty acids at concentrations present in jack pine. In contrast, fatty acids and lipid composition of a non-host were not suitable for the beetle larvae or the fungus. Apparently, concentrations of individual, rather than total, fatty acids determined the suitability of jack pine. Furthermore, sampling of host and non-host tree species across Canada demonstrated that the composition of jack pine fatty acids was similar to the different populations of beetle’s historical hosts. These results demonstrate that fatty acids composition compatible with insect herbivores and their microbial symbionts can be important factor defining host suitability to invasive insects. PMID:27583820

Molecular cloning and characterization of NcROP2Fam-1, a member of the ROP2 family of rhoptry proteins in Neospora caninum that is targeted by antibodies neutralizing host cell invasion in vitro.

Science.gov (United States)

Alaeddine, Ferial; Hemphill, Andrew; Debache, Karim; Guionaud, Christophe

2013-07-01

Recent publications demonstrated that a fragment of a Neospora caninum ROP2 family member antigen represents a promising vaccine candidate. We here report on the cloning of the cDNA encoding this protein, N. caninum ROP2 family member 1 (NcROP2Fam-1), its molecular characterization and localization. The protein possesses the hallmarks of ROP2 family members and is apparently devoid of catalytic activity. NcROP2Fam-1 is synthesized as a pre-pro-protein that is matured to 2 proteins of 49 and 55 kDa that localize to rhoptry bulbs. Upon invasion the protein is associated with the nascent parasitophorous vacuole membrane (PVM), evacuoles surrounding the host cell nucleus and, in some instances, the surface of intracellular parasites. Staining was also observed within the cyst wall of 'cysts' produced in vitro. Interestingly, NcROP2Fam-1 was also detected on the surface of extracellular parasites entering the host cells and antibodies directed against NcROP2Fam-1-specific peptides partially neutralized invasion in vitro. We conclude that, in spite of the general belief that ROP2 family proteins are intracellular antigens, NcROP2Fam-1 can also be considered as an extracellular antigen, a property that should be taken into account in further experiments employing ROP2 family proteins as vaccines.

Phenotype-dependent effects of EpCAM expression on growth and invasion of human breast cancer cell lines

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Martowicz, Agnieszka; Spizzo, Gilbert; Gastl, Guenther; Untergasser, Gerold

2012-01-01

The epithelial cell adhesion molecule (EpCAM) has been shown to be overexpressed in breast cancer and stem cells and has emerged as an attractive target for immunotherapy of breast cancer patients. This study analyzes the effects of EpCAM on breast cancer cell lines with epithelial or mesenchymal phenotype. For this purpose, shRNA-mediated knockdown of EpCAM gene expression was performed in EpCAM high breast cancer cell lines with epithelial phenotype (MCF-7, T47D and SkBR3). Moreover, EpCAM low breast carcinoma cell lines with mesenchymal phenotype (MDA-MB-231, Hs578t) and inducible overexpression of EpCAM were used to study effects on proliferation, migration and in vivo growth. In comparison to non-specific silencing controls (n/s-crtl) knockdown of EpCAM (E#2) in EpCAM high cell lines resulted in reduced cell proliferation under serum-reduced culture conditions. Moreover, DNA synthesis under 3D culture conditions in collagen was significantly reduced. Xenografts of MCF-7 and T47D cells with knockdown of EpCAM formed smaller tumors that were less invasive. EpCAM low cell lines with tetracycline-inducible overexpression of EpCAM showed no increased cell proliferation or migration under serum-reduced growth conditions. MDA-MB-231 xenografts with EpCAM overexpression showed reduced invasion into host tissue and more infiltrates of chicken granulocytes. The role of EpCAM in breast cancer strongly depends on the epithelial or mesenchymal phenotype of tumor cells. Cancer cells with epithelial phenotype need EpCAM as a growth- and invasion-promoting factor, whereas tumor cells with a mesenchymal phenotype are independent of EpCAM in invasion processes and tumor progression. These findings might have clinical implications for EpCAM-based targeting strategies in patients with invasive breast cancer

PSGL-1 on Leukocytes is a Critical Component of the Host Immune Response against Invasive Pneumococcal Disease.

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Elisa Ramos-Sevillano

2016-03-01

Full Text Available Bacterial uptake by phagocytic cells is a vital event in the clearance of invading pathogens such as Streptococcus pneumoniae. A major role of the P-selectin glycoprotein ligand-1 (PSGL-1 on leukocytes against invasive pneumococcal disease is described in this study. Phagocytosis experiments using different serotypes demonstrated that PSGL-1 is involved in the recognition, uptake and killing of S. pneumoniae. Co-localization of several clinical isolates of S. pneumoniae with PSGL-1 was demonstrated, observing a rapid and active phagocytosis in the presence of PSGL-1. Furthermore, the pneumococcal capsular polysaccharide and the main autolysin of the bacterium--the amidase LytA--were identified as bacterial ligands for PSGL-1. Experimental models of pneumococcal disease including invasive pneumonia and systemic infection showed that bacterial levels were markedly increased in the blood of PSGL-1-/- mice. During pneumonia, PSGL-1 controls the severity of pneumococcal dissemination from the lung to the bloodstream. In systemic infection, a major role of PSGL-1 in host defense is to clear the bacteria in the systemic circulation controlling bacterial replication. These results confirmed the importance of this receptor in the recognition and clearance of S. pneumoniae during invasive pneumococcal disease. Histological and cellular analysis demonstrated that PSGL-1-/- mice have increased levels of T cells migrating to the lung than the corresponding wild-type mice. In contrast, during systemic infection, PSGL-1-/- mice had increased numbers of neutrophils and macrophages in blood, but were less effective controlling the infection process due to the lack of this functional receptor. Overall, this study demonstrates that PSGL-1 is a novel receptor for S. pneumoniae that contributes to protection against invasive pneumococcal disease.

Invasion of Dendritic Cells, Macrophages and Neutrophils by the Bordetella Adenylate Cyclase Toxin: A Subversive Move to Fool Host Immunity.

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Fedele, Giorgio; Schiavoni, Ilaria; Adkins, Irena; Klimova, Nela; Sebo, Peter

2017-09-21

Adenylate cyclase toxin (CyaA) is released in the course of B. pertussis infection in the host's respiratory tract in order to suppress its early innate and subsequent adaptive immune defense. CD11b-expressing dendritic cells (DC), macrophages and neutrophils are professional phagocytes and key players of the innate immune system that provide a first line of defense against invading pathogens. Recent findings revealed the capacity of B. pertussis CyaA to intoxicate DC with high concentrations of 3',5'-cyclic adenosine monophosphate (cAMP), which ultimately skews the host immune response towards the expansion of Th17 cells and regulatory T cells. CyaA-induced cAMP signaling swiftly incapacitates opsonophagocytosis, oxidative burst and NO-mediated killing of bacteria by neutrophils and macrophages. The subversion of host immune responses by CyaA after delivery into DC, macrophages and neutrophils is the subject of this review.

Adipose tissue-derived stem cells promote pancreatic cancer cell proliferation and invasion

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Ji, S.Q.; Cao, J.; Zhang, Q.Y.; Li, Y.Y.; Yan, Y.Q.; Yu, F.X.

2013-01-01

To explore the effects of adipose tissue-derived stem cells (ADSCs) on the proliferation and invasion of pancreatic cancer cells in vitro and the possible mechanism involved, ADSCs were cocultured with pancreatic cancer cells, and a cell counting kit (CCK-8) was used to detect the proliferation of pancreatic cancer cells. ELISA was used to determine the concentration of stromal cell-derived factor-1 (SDF-1) in the supernatants. RT-PCR was performed to detect the expression of the chemokine receptor CXCR4 in pancreatic cancer cells and ADSCs. An in vitro invasion assay was used to measure invasion of pancreatic cancer cells. SDF-1 was detected in the supernatants of ADSCs, but not in pancreatic cancer cells. Higher CXCR4 mRNA levels were detected in the pancreatic cancer cell lines compared with ADSCs (109.3±10.7 and 97.6±7.6 vs 18.3±1.7, respectively; P<0.01). In addition, conditioned medium from ADSCs promoted the proliferation and invasion of pancreatic cancer cells, and AMD3100, a CXCR4 antagonist, significantly downregulated these growth-promoting effects. We conclude that ADSCs can promote the proliferation and invasion of pancreatic cancer cells, which may involve the SDF-1/CXCR4 axis

Adipose tissue-derived stem cells promote pancreatic cancer cell proliferation and invasion

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Ji, S.Q.; Cao, J. [Department of Liver Surgery I, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai (China); Zhang, Q.Y.; Li, Y.Y. [Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Wenzhou Medical College, Wenzhou (China); Yan, Y.Q. [Department of Liver Surgery I, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai (China); Yu, F.X. [Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Wenzhou Medical College, Wenzhou (China)

2013-09-27

To explore the effects of adipose tissue-derived stem cells (ADSCs) on the proliferation and invasion of pancreatic cancer cells in vitro and the possible mechanism involved, ADSCs were cocultured with pancreatic cancer cells, and a cell counting kit (CCK-8) was used to detect the proliferation of pancreatic cancer cells. ELISA was used to determine the concentration of stromal cell-derived factor-1 (SDF-1) in the supernatants. RT-PCR was performed to detect the expression of the chemokine receptor CXCR4 in pancreatic cancer cells and ADSCs. An in vitro invasion assay was used to measure invasion of pancreatic cancer cells. SDF-1 was detected in the supernatants of ADSCs, but not in pancreatic cancer cells. Higher CXCR4 mRNA levels were detected in the pancreatic cancer cell lines compared with ADSCs (109.3±10.7 and 97.6±7.6 vs 18.3±1.7, respectively; P<0.01). In addition, conditioned medium from ADSCs promoted the proliferation and invasion of pancreatic cancer cells, and AMD3100, a CXCR4 antagonist, significantly downregulated these growth-promoting effects. We conclude that ADSCs can promote the proliferation and invasion of pancreatic cancer cells, which may involve the SDF-1/CXCR4 axis.

Mechanisms of invasion from sporozoite and merozoíto of Plasmodium

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Lilian M. Spencer

2016-05-01

Full Text Available Malaria or paludismo is caused in humans by four species of Plasmodium belonging to phylum Apicomplexa: ovale, malaria, vivax and falciparum, being the last, the responsible of the clinical complication and death in the vertebrate host. Plasmodium parasite possess a specialized secretory organelles called rhoptries, micronemes and dense granules that facilitate invasion of host cells. The sporozoite stage of Plasmodium travels through the different cells of vertebrate host until it reaches the hepatocyte and have been form the parasitophorous vacuole. The infected hepatocytes rupture, results in the releasing thousands of daughter merozoites that invade the erythrocytes with the formation of parasitophorous vacuole too. Several researchers suggest the gliding motility mechanism as the responsible of hepatocyte invasion. While, which the erythrocyte invasion process has been described as the result of tree steps: first contact, re-orientation and invasion. In this review the surface proteins of merozoites and esporozoites are pointed out as the most important factors for the molecular invasion mechanisms until the elaboration of the parasitophorous vacuole. These proteins that take part in these mechanisms are the possible candidates in the design of an anti-malaria vaccine.

Extracellular Molecules Involved in Cancer Cell Invasion

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Stivarou, Theodora; Patsavoudi, Evangelia

2015-01-01

Nowadays it is perfectly clear that understanding and eradicating cancer cell invasion and metastasis represent the crucial, definitive points in cancer therapeutics. During the last two decades there has been a great interest in the understanding of the extracellular molecular mechanisms involved in cancer cell invasion. In this review, we highlight the findings concerning these processes, focusing in particular on extracellular molecules, including extracellular matrix proteins and their receptors, growth factors and their receptors, matrix metalloproteinases and extracellular chaperones. We report the molecular mechanisms underlying the important contribution of this pool of molecules to the complex, multi-step phenomenon of cancer cell invasion

Deletion of a malaria invasion gene reduces death and anemia, in model hosts.

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Noé D Gómez

Full Text Available Malaria parasites induce complex cellular and clinical phenotypes, including anemia, cerebral malaria and death in a wide range of mammalian hosts. Host genes and parasite 'toxins' have been implicated in malarial disease, but the contribution of parasite genes remains to be fully defined. Here we assess disease in BALB/c mice and Wistar rats infected by the rodent malaria parasite Plasmodium berghei with a gene knock out for merozoite surface protein (MSP 7. MSP7 is not essential for infection but in P. falciparum, it enhances erythrocyte invasion by 20%. In vivo, as compared to wild type, the P. berghei Δmsp7 mutant is associated with an abrogation of death and a decrease from 3% to 2% in peak, circulating parasitemia. The Δmsp7 mutant is also associated with less anemia and modest increase in the size of follicles in the spleen. Together these data show that deletion of a single parasite invasion ligand modulates blood stage disease, as measured by death and anemia. This work is the first to assess the contribution of a gene present in all plasmodial species in severe disease.

Squamous cell carcinoma - invasive (image)

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This irregular red nodule is an invasive squamous cell carcinoma (a form of skin cancer). Initial appearance, shown here, may be very similar to a noncancerous growth called a keratoacanthoma. Squamous cell cancers ...

Invasive Glioblastoma Cells Acquire Stemness and Increased Akt Activation

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Jennifer R. Molina

2010-06-01

Full Text Available Glioblastoma multiforme (GBM is the most frequent and most aggressive brain tumor in adults. The dismal prognosis is due to postsurgery recurrences arising from escaped invasive tumor cells. The signaling pathways activated in invasive cells are under investigation, and models are currently designed in search for therapeutic targets. We developed here an in vivo model of human invasive GBM in mouse brain from a GBM cell line with moderate tumorigenicity that allowed simultaneous primary tumor growth and dispersal of tumor cells in the brain parenchyma. This strategy allowed for the first time the isolation and characterization of matched sets of tumor mass (Core and invasive (Inv cells. Both cell populations, but more markedly Inv cells, acquired stem cell markers, neurosphere renewal ability, and resistance to rapamycin-induced apoptosis relative to parental cells. The comparative phenotypic analysis between Inv and Core cells showed significantly increased tumorigenicity in vivo and increased invasion with decreased proliferation in vitro for Inv cells. Examination of a large array of signaling pathways revealed extracellular signal-regulated kinase (Erk down-modulation and Akt activation in Inv cells and an opposite profile in Core cells. Akt activation correlated with the increased tumorigenicity, stemness, and invasiveness, whereas Erk activation correlated with the proliferation of the cells. These results underscore complementary roles of the Erk and Akt pathways for GBM proliferation and dispersal and raise important implications for a concurrent inhibitory therapy.

Extracellular Molecules Involved in Cancer Cell Invasion

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Theodora Stivarou

2015-01-01

Full Text Available Nowadays it is perfectly clear that understanding and eradicating cancer cell invasion and metastasis represent the crucial, definitive points in cancer therapeutics. During the last two decades there has been a great interest in the understanding of the extracellular molecular mechanisms involved in cancer cell invasion. In this review, we highlight the findings concerning these processes, focusing in particular on extracellular molecules, including extracellular matrix proteins and their receptors, growth factors and their receptors, matrix metalloproteinases and extracellular chaperones. We report the molecular mechanisms underlying the important contribution of this pool of molecules to the complex, multi-step phenomenon of cancer cell invasion.

Type III methyltransferase M.NgoAX from Neisseria gonorrhoeae FA1090 regulates biofilm formation and human cell invasion

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Agnieszka eKwiatek

2015-12-01

Full Text Available Neisseria gonorrhoeae is the etiological factor of the sexually transmitted gonorrhea disease that may lead, under specific conditions, to systemic infections. The gonococcal genome encodes many Restriction Modification (RM systems, which main biological role is to defend the pathogen from potentially harmful foreign DNA. However, RM systems seem also to be involved in several other functions. In this study, we examined the effect of inactivation the N. gonorrhoeae FA1090 ngo0545 gene encoding M.NgoAX methyltransferase on the global gene expression, biofilm formation, interactions with human epithelial host cells and overall bacterial growth. Expression microarrays showed at least a two-fold deregulation of a total of 121 genes in the NgoAX knock-out mutant compared to the wt strain under standard grow conditions. As determined by the assay with crystal violet, the NgoAX knock-out strain formed a slightly larger biofilm biomass per cell than the wt strain (OD570/600 = 13.8  2.24 and 9.35  2.06, respectively. SCLM observations showed that the biofilm formed by the gonococcal ngo0545 gene mutant is more relaxed and dispersed than the one formed by the wt strain. Thickness of the biofilm formed by both strains was 48.3 (14.9 µm for the mutant and 28.6 (4.0 µm for the wt. This more relaxed feature of the biofilm in respect to adhesion and bacterial interactions seems advantageous for pathogenesis of the NgoAX-deficient gonococci at the stage of human epithelial cell invasion. Indeed, the overall adhesion of mutant bacterial cells to human cells was lower than adhesion of the wt gonococci (adhesion index = 0.672 ( 0.2 and 2.15 ( 1.53, respectively; yet, a higher number of mutant than wt bacteria were found inside the Hec-1-B epithelial cells (invasion index = 3.38 ( 0.93  105 for mutant and 4.67 ( 3.09  104 for the wt strain. These results indicate that NgoAX-deficient cells have lower ability to attach to human cells

Atomic evidence that modification of H-bonds established with amino acids critical for host-cell binding induces sterile immunity against malaria

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Patarroyo, Manuel E., E-mail: mepatarr@mail.com [Fundacion Instituto de Inmunologia de Colombia (FIDIC), Bogota (Colombia); Universidad Nacional de Colombia, Bogota (Colombia); Cifuentes, Gladys [Fundacion Instituto de Inmunologia de Colombia (FIDIC), Bogota (Colombia); Universidad del Rosario, Bogota (Colombia); Pirajan, Camilo; Moreno-Vranich, Armando [Fundacion Instituto de Inmunologia de Colombia (FIDIC), Bogota (Colombia); Vanegas, Magnolia [Fundacion Instituto de Inmunologia de Colombia (FIDIC), Bogota (Colombia); Universidad Nacional de Colombia, Bogota (Colombia); Universidad del Rosario, Bogota (Colombia)

2010-04-09

Based on the 3D X-ray crystallographic structures of relevant proteins of the malaria parasite involved in invasion to host cells and 3D NMR structures of High Activity Binding Peptides (HABPs) and their respective analogues, it was found that HABPs are rendered into highly immunogenic and sterile immunity inducers in the Aotus experimental model by modifying those amino acids that establish H-bonds with other HABPs or binding to host's cells. This finding adds striking and novel physicochemical principles, at the atomic level, for a logical and rational vaccine development methodology against infectious disease, among them malaria.

Atomic evidence that modification of H-bonds established with amino acids critical for host-cell binding induces sterile immunity against malaria

International Nuclear Information System (INIS)

Patarroyo, Manuel E.; Cifuentes, Gladys; Pirajan, Camilo; Moreno-Vranich, Armando; Vanegas, Magnolia

2010-01-01

Based on the 3D X-ray crystallographic structures of relevant proteins of the malaria parasite involved in invasion to host cells and 3D NMR structures of High Activity Binding Peptides (HABPs) and their respective analogues, it was found that HABPs are rendered into highly immunogenic and sterile immunity inducers in the Aotus experimental model by modifying those amino acids that establish H-bonds with other HABPs or binding to host's cells. This finding adds striking and novel physicochemical principles, at the atomic level, for a logical and rational vaccine development methodology against infectious disease, among them malaria.

Src Family Kinases Mediate Betel Quid-Induced Oral Cancer Cell Motility and Could Be a Biomarker for Early Invasion in Oral Squamous Cell Carcinoma

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Jeff Yi-Fu Chen

2008-12-01

Full Text Available Betel quid (BQ-chewing oral cancer is a prevalent disease in many countries of Southeast Asia. Yet, the precise disease mechanism remains largely unknown. Here, we show that BQ extract-induced cell motility in three oral cancer cells (Ca9-22, SAS, and SCC9 presumably involves the Src family kinases (SFKs. Besides, BQ extract can markedly induce cell migration of wild type mouse embryonic fibroblasts (MEFs but not MEFs lacking three SFK members, namely, Src, Yes, and Fyn, indicating the requirement of SFKs for BQ-induced cell motility. Betel quid extract can also elevate cellular SFK activities because phosphorylation of tyrosine 416 at the catalytic domain is increased, which in turn promotes phosphorylation of an in vitro substrate, enolase. Furthermore, we identified that areca nut, a major component of BQ, is the key factor accounting for BQ-induced cell migration and invasion through SFKs-mediated signaling pathways. Immunohistochemistry revealed that, particularly in BQ-chewing cases, the activity of SFKs was significantly higher in tumor-adjacent mucosa than that in solid tumor areas (P < .01. These results suggest a possible role of SFKs in tumor-host interface and thus in early tumor invasion in vivo. Consistent with this is the observation that activation of SFKs is colocalized with invasive tumor fronts in oral squamous cell carcinoma. Together, we conclude that SFKs may represent a potential biomarker of invasion and therapeutic target in BQ-induced oral cancer.

Pseudomonas aeruginosa invasion and cytotoxicity are independent events, both of which involve protein tyrosine kinase activity.

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Evans, D J; Frank, D W; Finck-Barbançon, V; Wu, C; Fleiszig, S M

1998-04-01

Pseudomonas aeruginosa clinical isolates exhibit invasive or cytotoxic phenotypes. Cytotoxic strains acquire some of the characteristics of invasive strains when a regulatory gene, exsA, that controls the expression of several extracellular proteins, is inactivated. exsA mutants are not cytotoxic and can be detected within epithelial cells by gentamicin survival assays. The purpose of this study was to determine whether epithelial cell invasion precedes and/or is essential for cytotoxicity. This was tested by measuring invasion (gentamicin survival) and cytotoxicity (trypan blue staining) of PA103 mutants deficient in specific exsA-regulated proteins and by testing the effect of drugs that inhibit invasion for their effect on cytotoxicity. A transposon mutant in the exsA-regulated extracellular factor exoU was neither cytotoxic nor invasive. Furthermore, several of the drugs that inhibited invasion did not prevent cytotoxicity. These results show that invasion and cytotoxicity are mutually exclusive events, inversely regulated by an exsA-encoded invasion inhibitor(s). Both involve host cell protein tyrosine kinase (PTK) activity, but they differ in that invasion requires Src family tyrosine kinases and calcium-calmodulin activity. PTK inhibitor drugs such as genistein may have therapeutic potential through their ability to block both invasive and cytotoxicity pathways via an action on the host cell.

Unique Cell Adhesion and Invasion Properties of Yersinia enterocolitica O:3, the Most Frequent Cause of Human Yersiniosis

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Uliczka, Frank; Pisano, Fabio; Schaake, Julia; Stolz, Tatjana; Rohde, Manfred; Fruth, Angelika; Strauch, Eckhard; Skurnik, Mikael; Batzilla, Julia; Rakin, Alexander; Heesemann, Jürgen; Dersch, Petra

2011-01-01

Many enteric pathogens are equipped with multiple cell adhesion factors which are important for host tissue colonization and virulence. Y. enterocolitica, a common food-borne pathogen with invasive properties, uses the surface proteins invasin and YadA for host cell binding and entry. In this study, we demonstrate unique cell adhesion and invasion properties of Y. enterocolitica serotype O:3 strains, the most frequent cause of human yersiniosis, and show that these differences are mainly attributable to variations affecting the function and expression of invasin in response to temperature. In contrast to other enteric Yersinia strains, invasin production in O:3 strains is constitutive and largely enhanced compared to other Y. enterocolitica serotypes, in which invA expression is temperature-regulated and significantly reduced at 37°C. Increase of invasin levels is caused by (i) an IS1667 insertion into the invA promoter region, which includes an additional promoter and RovA and H-NS binding sites, and (ii) a P98S substitution in the invA activator protein RovA rendering the regulator less susceptible to proteolysis. Both variations were shown to influence bacterial colonization in a murine infection model. Furthermore, we found that co-expression of YadA and down-regulation of the O-antigen at 37°C is required to allow efficient internalization by the InvA protein. We conclude that even small variations in the expression of virulence factors can provoke a major difference in the virulence properties of closely related pathogens which may confer better survival or a higher pathogenic potential in a certain host or host environment. PMID:21750675

Stably Integrated luxCDABE for Assessment of Salmonella Invasion Kinetics

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Kelly N. Flentie

2008-09-01

Full Text Available Salmonella Typhimurium is a common cause of gastroenteritis in humans and also localizes to neoplastic tumors in animals. Invasion of specific eukaryotic cells is a key mechanism of Salmonella interactions with host tissues. Early stages of gastrointestinal cell invasion are mediated by a Salmonella type III secretion system, powered by the adenosine triphosphatase invC. The aim of this work was to characterize the invC dependence of invasion kinetics into disparate eukaryotic cells traditionally used as models of gut epithelium or neoplasms. Thus, a nondestructive real-time assay was developed to report eukaryotic cell invasion kinetics using lux+ Salmonella that contain chromosomally integrated luxCDABE genes. Bioluminescence-based invasion assays using lux+ Salmonella exhibited inoculum dose-response correlation, distinguished invasion-competent from invasion-incompetent Salmonella, and discriminated relative Salmonella invasiveness in accordance with environmental conditions that induce invasion gene expression. In standard gentamicin protection assays, bioluminescence from lux+ Salmonella correlated with recovery of colony-forming units of internalized bacteria and could be visualized by bioluminescence microscopy. Furthermore, this assay distinguished invasion-competent from invasion-incompetent bacteria independent of gentamicin treatment in real time. Bioluminescence reported Salmonella invasion of disparate eukaryotic cell lines, including neoplastic melanoma, colon adenocarcinoma, and glioma cell lines used in animal models of malignancy. In each case, Salmonella invasion of eukaryotic cells was invC dependent.

Als3 is a Candida albicans invasin that binds to cadherins and induces endocytosis by host cells.

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Quynh T Phan

2007-03-01

Full Text Available Candida albicans is the most common cause of hematogenously disseminated and oropharyngeal candidiasis. Both of these diseases are characterized by fungal invasion of host cells. Previously, we have found that C. albicans hyphae invade endothelial cells and oral epithelial cells in vitro by inducing their own endocytosis. Therefore, we set out to identify the fungal surface protein and host cell receptors that mediate this process. We found that the C. albicans Als3 is required for the organism to be endocytosed by human umbilical vein endothelial cells and two different human oral epithelial lines. Affinity purification experiments with wild-type and an als3delta/als3delta mutant strain of C. albicans demonstrated that Als3 was required for C. albicans to bind to multiple host cell surface proteins, including N-cadherin on endothelial cells and E-cadherin on oral epithelial cells. Furthermore, latex beads coated with the recombinant N-terminal portion of Als3 were endocytosed by Chinese hamster ovary cells expressing human N-cadherin or E-cadherin, whereas control beads coated with bovine serum albumin were not. Molecular modeling of the interactions of the N-terminal region of Als3 with the ectodomains of N-cadherin and E-cadherin indicated that the binding parameters of Als3 to either cadherin are similar to those of cadherin-cadherin binding. Therefore, Als3 is a fungal invasin that mimics host cell cadherins and induces endocytosis by binding to N-cadherin on endothelial cells and E-cadherin on oral epithelial cells. These results uncover the first known fungal invasin and provide evidence that C. albicans Als3 is a molecular mimic of human cadherins.

Invasion of vascular cells in vitro by Porphyromonas endodontalis.

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Dorn, B R; Harris, L J; Wujick, C T; Vertucci, F J; Progulske-Fox, A

2002-04-01

The objective of this study was to determine whether laboratory strains and clinical isolates of microorganisms associated with root canal infections can invade primary cultures of cardiovascular cells. Quantitative levels of bacterial invasion of human coronary artery endothelial cells (HCAEC) and coronary artery smooth muscle cells (CASMC) were measured using a standard antibiotic protection assay. Transmission electron microscopy was used to confirm and visualize internalization within the vascular cells. Of the laboratory and clinical strains tested, only P. endodontalis ATCC 35406 was invasive in an antibiotic protection assay using HCAEC and CASMC. Invasion of P. endodontalis ATCC 35406 was confirmed by transmission electron microscopy. Certain microorganisms associated with endodontic infections are invasive. If bacterial invasion of the vasculature contributes to the pathogenesis of cardiovascular disease, then microorganisms in the pulp chamber represent potential pathogens.

Effects of Mechanical Properties on Tumor Invasion: Insights from a Cellular Model

KAUST Repository

Li, YZ

2014-08-01

Understanding the regulating mechanism of tumor invasion is of crucial importance for both fundamental cancer research and clinical applications. Previous in vivo experiments have shown that invasive cancer cells dissociate from the primary tumor and invade into the stroma, forming an irregular invasive morphology. Although cell movements involved in tumor invasion are ultimately driven by mechanical forces of cell-cell interactions and tumor-host interactions, how these mechanical properties affect tumor invasion is still poorly understood. In this study, we use a recently developed two-dimensional cellular model to study the effects of mechanical properties on tumor invasion. We study the effects of cell-cell adhesions as well as the degree of degradation and stiffness of extracellular matrix (ECM). Our simulation results show that cell-cell adhesion relationship must be satisfied for tumor invasion. Increased adhesion to ECM and decreased adhesion among tumor cells result in invasive tumor behaviors. When this invasive behavior occurs, ECM plays an important role for both tumor morphology and the shape of invasive cancer cells. Increased stiffness and stronger degree of degradation of ECM promote tumor invasion, generating more aggressive tumor invasive morphologies. It can also generate irregular shape of invasive cancer cells, protruding towards ECM. The capability of our model suggests it a useful tool to study tumor invasion and might be used to propose optimal treatment in clinical applications.

Hakai reduces cell-substratum adhesion and increases epithelial cell invasion

International Nuclear Information System (INIS)

Rodríguez-Rigueiro, Teresa; Valladares-Ayerbes, Manuel; Haz-Conde, Mar; Aparicio, Luis A; Figueroa, Angélica

2011-01-01

The dynamic regulation of cell-cell adhesions is crucial for developmental processes, including tissue formation, differentiation and motility. Adherens junctions are important components of the junctional complex between cells and are necessary for maintaining cell homeostasis and normal tissue architecture. E-cadherin is the prototype and best-characterized protein member of adherens junctions in mammalian epithelial cells. Regarded as a tumour suppressor, E-cadherin loss is associated with poor prognosis in carcinoma. The E3 ubiquitin-ligase Hakai was the first reported posttranslational regulator of the E-cadherin complex. Hakai specifically targetted E-cadherin for internalization and degradation and thereby lowered epithelial cell-cell contact. Hakai was also implicated in controlling proliferation, and promoted cancer-related gene expression by increasing the binding of RNA-binding protein PSF to RNAs encoding oncogenic proteins. We sought to investigate the possible implication of Hakai in cell-substratum adhesions and invasion in epithelial cells. Parental MDCK cells and MDCK cells stably overexpressing Hakai were used to analyse cell-substratum adhesion and invasion capabilities. Western blot and immunofluoresecence analyses were performed to assess the roles of Paxillin, FAK and Vinculin in cell-substratum adhesion. The role of the proteasome in controlling cell-substratum adhesion was studied using two proteasome inhibitors, lactacystin and MG132. To study the molecular mechanisms controlling Paxillin expression, MDCK cells expressing E-cadherin shRNA in a tetracycline-inducible manner was employed. Here, we present evidence that implicate Hakai in reducing cell-substratum adhesion and increasing epithelial cell invasion, two hallmark features of cancer progression and metastasis. Paxillin, an important protein component of the cell-matrix adhesion, was completely absent from focal adhesions and focal contacts in Hakai-overexpressing MDCK cells. The

A PET Imaging Strategy to Visualize Activated T Cells in Acute Graft-versus-Host Disease Elicited by Allogenic Hematopoietic Cell Transplant.

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Ronald, John A; Kim, Byung-Su; Gowrishankar, Gayatri; Namavari, Mohammad; Alam, Israt S; D'Souza, Aloma; Nishikii, Hidekazu; Chuang, Hui-Yen; Ilovich, Ohad; Lin, Chih-Feng; Reeves, Robert; Shuhendler, Adam; Hoehne, Aileen; Chan, Carmel T; Baker, Jeanette; Yaghoubi, Shahriar S; VanBrocklin, Henry F; Hawkins, Randall; Franc, Benjamin L; Jivan, Salma; Slater, James B; Verdin, Emily F; Gao, Kenneth T; Benjamin, Jonathan; Negrin, Robert; Gambhir, Sanjiv Sam

2017-06-01

A major barrier to successful use of allogeneic hematopoietic cell transplantation is acute graft-versus-host disease (aGVHD), a devastating condition that arises when donor T cells attack host tissues. With current technologies, aGVHD diagnosis is typically made after end-organ injury and often requires invasive tests and tissue biopsies. This affects patient prognosis as treatments are dramatically less effective at late disease stages. Here, we show that a novel PET radiotracer, 2'-deoxy-2'-[18F]fluoro-9-β-D-arabinofuranosylguanine ([18F]F-AraG), targeted toward two salvage kinase pathways preferentially accumulates in activated primary T cells. [18F]F-AraG PET imaging of a murine aGVHD model enabled visualization of secondary lymphoid organs harboring activated donor T cells prior to clinical symptoms. Tracer biodistribution in healthy humans showed favorable kinetics. This new PET strategy has great potential for early aGVHD diagnosis, enabling timely treatments and improved patient outcomes. [18F]F-AraG may be useful for imaging activated T cells in various biomedical applications. Cancer Res; 77(11); 2893-902. ©2017 AACR . ©2017 American Association for Cancer Research.

Nerve Invasion by Epithelial Cells in Benign Breast Diseases

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Yu-Jan Chan

2009-03-01

Full Text Available Nerve invasion by glandular epithelial cells in a lesion is usually regarded as invasive carcinoma. However, some benign conditions in the pancreas, prostate, breast and other organs may show involvement of nerve bundles by benign epithelial cells. We report an 18-year-old female with nerve invasion in benign breast disease. The lesion in her right breast revealed fibrocystic changes with ductal hyperplasia and stromal sclerosis. Perineural and intraneural involvement by bland-looking small ducts lined by 2 layers of cells including an outer layer of myoepithelial cells were found, suggestive of benign nerve invasion. There was no evidence of malignant cells in any of the sections. The patient remains well after 31 months of follow-up. About 44 cases of nerve invasion in benign breast diseases have been reported in the literature. It is necessary to carefully evaluate nerve involvement in breast lesions to avoid over-diagnosis and inappropriate operation.

Invasion of Human Oral Epithelial Cells by Prevotella intermedia

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Dorn, Brian R.; Leung, K.-P.; Progulske-Fox, Ann

1998-01-01

Invasion of oral epithelial cells by pathogenic oral bacteria may represent an important virulence factor in the progression of periodontal disease. Here we report that a clinical isolate of Prevotella intermedia, strain 17, was found to invade a human oral epithelial cell line (KB), whereas P. intermedia 27, another clinical isolate, and P. intermedia 25611, the type strain, were not found to invade the cell line. Invasion was quantified by the recovery of viable bacteria following a standard antibiotic protection assay and observed by electron microscopy. Cytochalasin D, cycloheximide, monodansylcadaverine, and low temperature (4°C) inhibited the internalization of P. intermedia 17. Antibodies raised against P. intermedia type C fimbriae and against whole cells inhibited invasion, but the anti-type-C-fimbria antibody inhibited invasion to a greater extent than the anti-whole-cell antibody. This work provides evidence that at least one strain of P. intermedia can invade an oral epithelial cell line and that the type C fimbriae and a cytoskeletal rearrangement are required for this invasion. PMID:9826397

Membrane-Wrapping Contributions to Malaria Parasite Invasion of the Human Erythrocyte

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Dasgupta, Sabyasachi; Auth, Thorsten; Gov, Nir S.; Satchwell, Timothy J.; Hanssen, Eric; Zuccala, Elizabeth S.; Riglar, David T.; Toye, Ashley M.; Betz, Timo; Baum, Jake; Gompper, Gerhard

2014-01-01

The blood stage malaria parasite, the merozoite, has a small window of opportunity during which it must successfully target and invade a human erythrocyte. The process of invasion is nonetheless remarkably rapid. To date, mechanistic models of invasion have focused predominantly on the parasite actomyosin motor contribution to the energetics of entry. Here, we have conducted a numerical analysis using dimensions for an archetypal merozoite to predict the respective contributions of the host-parasite interactions to invasion, in particular the role of membrane wrapping. Our theoretical modeling demonstrates that erythrocyte membrane wrapping alone, as a function of merozoite adhesive and shape properties, is sufficient to entirely account for the first key step of the invasion process, that of merozoite reorientation to its apex and tight adhesive linkage between the two cells. Next, parasite-induced reorganization of the erythrocyte cytoskeleton and release of parasite-derived membrane can also account for a considerable energetic portion of actual invasion itself, through membrane wrapping. Thus, contrary to the prevailing dogma, wrapping by the erythrocyte combined with parasite-derived membrane release can markedly reduce the expected contributions of the merozoite actomyosin motor to invasion. We therefore propose that invasion is a balance between parasite and host cell contributions, evolved toward maximal efficient use of biophysical forces between the two cells. PMID:24988340

Indirubin inhibits cell proliferation, migration, invasion and angiogenesis in tumor-derived endothelial cells

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Li Z

2018-05-01

Full Text Available Zhuohong Li, Chaofu Zhu, Baiping An, Yu Chen, Xiuyun He, Lin Qian, Lan Lan, Shijie Li Department of Oncology, The Affiliated Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China Purpose: Hepatocellular carcinoma is one of the most predominant malignancies with high fatality rate and its incidence is rising at an alarming rate because of its resistance to radio- and chemotherapy. Indirubin is the major active anti-tumor ingredient of a traditional Chinese herbal medicine. The present study aimed to analyze the effects of indirubin on cell proliferation, migration, invasion, and angiogenesis of tumor-derived endothelial cells (Td-EC. Methods: Td-EC were derived from human umbilical vein endothelial cells (HUVEC by treating HUVEC with the conditioned medium of human liver cancer cell line HepG2. Cell proliferation, migration, invasion, and angiogenesis were assessed by MTT, wound healing, in vitro cell invasion, and in vitro tube formation assay. Results: Td-EC were successfully obtained from HUVEC cultured with 50% culture supernatant from serum-starved HepG2 cells. Indirubin significantly inhibited Td-EC proliferation in a dose- and time-dependent manner. Indirubin also inhibited Td-EC migration, invasion, and angiogenesis. However, indirubin’s effects were weaker on HUVEC than Td-EC. Conclusion: Indirubin significantly inhibited Td-EC proliferation, migration, invasion, and angiogenesis. Keywords: indirubin, Td-EC, proliferation, migration, invasion, angiogenesis

Improved Detection of Invasive Pulmonary Aspergillosis Arising during Leukemia Treatment Using a Panel of Host Response Proteins and Fungal Antigens.

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Allan R Brasier

Full Text Available Invasive pulmonary aspergillosis (IPA is an opportunistic fungal infection in patients undergoing chemotherapy for hematological malignancy, hematopoietic stem cell transplant, or other forms of immunosuppression. In this group, Aspergillus infections account for the majority of deaths due to mold pathogens. Although early detection is associated with improved outcomes, current diagnostic regimens lack sensitivity and specificity. Patients undergoing chemotherapy, stem cell transplantation and lung transplantation were enrolled in a multi-site prospective observational trial. Proven and probable IPA cases and matched controls were subjected to discovery proteomics analyses using a biofluid analysis platform, fractionating plasma into reproducible protein and peptide pools. From 556 spots identified by 2D gel electrophoresis, 66 differentially expressed post-translationally modified plasma proteins were identified in the leukemic subgroup only. This protein group was rich in complement components, acute-phase reactants and coagulation factors. Low molecular weight peptides corresponding to abundant plasma proteins were identified. A candidate marker panel of host response (9 plasma proteins, 4 peptides, fungal polysaccharides (galactomannan, and cell wall components (β-D glucan were selected by statistical filtering for patients with leukemia as a primary underlying diagnosis. Quantitative measurements were developed to qualify the differential expression of the candidate host response proteins using selective reaction monitoring mass spectrometry assays, and then applied to a separate cohort of 57 patients with leukemia. In this verification cohort, a machine learning ensemble-based algorithm, generalized pathseeker (GPS produced a greater case classification accuracy than galactomannan (GM or host proteins alone. In conclusion, Integration of host response proteins with GM improves the diagnostic detection of probable IPA in patients

Temperature shift and host cell contact up-regulate sporozoite expression of Plasmodium falciparum genes involved in hepatocyte infection.

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Anthony Siau

Full Text Available Plasmodium sporozoites are deposited in the skin by Anopheles mosquitoes. They then find their way to the liver, where they specifically invade hepatocytes in which they develop to yield merozoites infective to red blood cells. Relatively little is known of the molecular interactions during these initial obligatory phases of the infection. Recent data suggested that many of the inoculated sporozoites invade hepatocytes an hour or more after the infective bite. We hypothesised that this pre-invasive period in the mammalian host prepares sporozoites for successful hepatocyte infection. Therefore, the genes whose expression becomes modified prior to hepatocyte invasion would be those likely to code for proteins implicated in the subsequent events of invasion and development. We have used P. falciparum sporozoites and their natural host cells, primary human hepatocytes, in in vitro co-culture system as a model for the pre-invasive period. We first established that under co-culture conditions, sporozoites maintain infectivity for an hour or more, in contrast to a drastic loss in infectivity when hepatocytes were not included. Thus, a differential transcriptome of salivary gland sporozoites versus sporozoites co-cultured with hepatocytes was established using a pan-genomic P. falciparum microarray. The expression of 532 genes was found to have been up-regulated following co-culture. A fifth of these genes had no orthologues in the genomes of Plasmodium species used in rodent models of malaria. Quantitative RT-PCR analysis of a selection of 21 genes confirmed the reliability of the microarray data. Time-course analysis further indicated two patterns of up-regulation following sporozoite co-culture, one transient and the other sustained, suggesting roles in hepatocyte invasion and liver stage development, respectively. This was supported by functional studies of four hitherto uncharacterized proteins of which two were shown to be sporozoite surface

Protein kinase a dependent phosphorylation of apical membrane antigen 1 plays an important role in erythrocyte invasion by the malaria parasite.

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Kerstin Leykauf

2010-06-01

Full Text Available Apicomplexan parasites are obligate intracellular parasites that infect a variety of hosts, causing significant diseases in livestock and humans. The invasive forms of the parasites invade their host cells by gliding motility, an active process driven by parasite adhesion proteins and molecular motors. A crucial point during host cell invasion is the formation of a ring-shaped area of intimate contact between the parasite and the host known as a tight junction. As the invasive zoite propels itself into the host-cell, the junction moves down the length of the parasite. This process must be tightly regulated and signalling is likely to play a role in this event. One crucial protein for tight-junction formation is the apical membrane antigen 1 (AMA1. Here we have investigated the phosphorylation status of this key player in the invasion process in the human malaria parasite Plasmodium falciparum. We show that the cytoplasmic tail of P. falciparum AMA1 is phosphorylated at serine 610. We provide evidence that the enzyme responsible for serine 610 phosphorylation is the cAMP regulated protein kinase A (PfPKA. Importantly, mutation of AMA1 serine 610 to alanine abrogates phosphorylation of AMA1 in vivo and dramatically impedes invasion. In addition to shedding unexpected new light on AMA1 function, this work represents the first time PKA has been implicated in merozoite invasion.

Insights into Host Cell Modulation and Induction of New Cells by the Corn Smut Ustilago maydis

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Amey Redkar

2017-05-01

Full Text Available Many filamentous fungal pathogens induce drastic modulation of host cells causing abnormal infectious structures such as galls, or tumors that arise as a result of re-programming in the original developmental cell fate of a colonized host cell. Developmental consequences occur predominantly with biotrophic phytopathogens. This suggests that these host structures result as an outcome of efficient defense suppression and intimate fungal–host interaction to suit the pathogen’s needs for completion of its infection cycle. This mini-review mainly summarizes host cell re-programming that occurs in the Ustilago maydis – maize interaction, in which the pathogen deploys cell-type specific effector proteins with varying activities. The fungus senses the physiological status and identity of colonized host cells and re-directs the endogenous developmental program of its host. The disturbance of host cell physiology and cell fate leads to novel cell shapes, increased cell size, and/or the number of host cells. We particularly highlight the strategies of U. maydis to induce physiologically varied host organs to form the characteristic tumors in both vegetative and floral parts of maize.

Staphylococcus aureus-induced G2/M phase transition delay in host epithelial cells increases bacterial infective efficiency.

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Ludmila Alekseeva

Full Text Available Staphylococcus aureus is a highly versatile, opportunistic pathogen and the etiological agent of a wide range of infections in humans and warm-blooded animals. The epithelial surface is its principal site of colonization and infection. In this work, we investigated the cytopathic effect of S. aureus strains from human and animal origins and their ability to affect the host cell cycle in human HeLa and bovine MAC-T epithelial cell lines. S. aureus invasion slowed down cell proliferation and induced a cytopathic effect, resulting in the enlargement of host cells. A dramatic decrease in the number of mitotic cells was observed in the infected cultures. Flow cytometry analysis revealed an S. aureus-induced delay in the G2/M phase transition in synchronous HeLa cells. This delay required the presence of live S. aureus since the addition of the heat-killed bacteria did not alter the cell cycle. The results of Western blot experiments showed that the G2/M transition delay was associated with the accumulation of inactive cyclin-dependent kinase Cdk1, a key inducer of mitosis entry, and with the accumulation of unphosphorylated histone H3, which was correlated with a reduction of the mitotic cell number. Analysis of S. aureus proliferation in asynchronous, G1- and G2-phase-enriched HeLa cells showed that the G2 phase was preferential for bacterial infective efficiency, suggesting that the G2 phase delay may be used by S. aureus for propagation within the host. Taken together, our results divulge the potential of S. aureus in the subversion of key cellular processes such as cell cycle progression, and shed light on the biological significance of S. aureus-induced host cell cycle alteration.

Subcompartmentalisation of proteins in the rhoptries correlates with ordered events of erythrocyte invasion by the blood stage malaria parasite.

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Elizabeth S Zuccala

Full Text Available Host cell infection by apicomplexan parasites plays an essential role in lifecycle progression for these obligate intracellular pathogens. For most species, including the etiological agents of malaria and toxoplasmosis, infection requires active host-cell invasion dependent on formation of a tight junction - the organising interface between parasite and host cell during entry. Formation of this structure is not, however, shared across all Apicomplexa or indeed all parasite lifecycle stages. Here, using an in silico integrative genomic search and endogenous gene-tagging strategy, we sought to characterise proteins that function specifically during junction-dependent invasion, a class of proteins we term invasins to distinguish them from adhesins that function in species specific host-cell recognition. High-definition imaging of tagged Plasmodium falciparum invasins localised proteins to multiple cellular compartments of the blood stage merozoite. This includes several that localise to distinct subcompartments within the rhoptries. While originating from the same organelle, however, each has very different dynamics during invasion. Apical Sushi Protein and Rhoptry Neck protein 2 release early, following the junction, whilst a novel rhoptry protein PFF0645c releases only after invasion is complete. This supports the idea that organisation of proteins within a secretory organelle determines the order and destination of protein secretion and provides a localisation-based classification strategy for predicting invasin function during apicomplexan parasite invasion.

Host cell reactivation and UV-enhanced reactivation in synchronized mammalian cells

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Lytle, C.D.; Schmidt, B.J.

1981-01-01

Does host cell reactivation (HCR) or UV-enhanced reactivation (UVER) of UV-irradiated Herpes simplex virus (UV-HSV) vary during the host mammalian cell cycle. The answer could be useful for interpreting UVER and or the two-component nature of the UV-HSV survival curve. Procedures were developed for infection of mitotically-synchronized CV-l monkey kidney cells. All virus survival curves determined at different cell cycle stages had two components with similar D 0 's and intercepts of the second components. Thus, no single stage of the host cell cycle was responsible for the second component of the virus survival curve. When the cells were UV-irradiated immediately prior to infection, enhanced survival of UV-HSV occurred for cell irradiation and virus infection initiated during late G 1 early S phase or late S early G 2 phase but not during early G 1 phase. For infection delayed by 24 h after cell irradiation, UVER was found at all investigated times. These results indicate that: (1) HCR is similar at all stages of the host cell cycle: and (2) the ''induction'' of UVER is not as rapid for cell-irradiation in early G 1 phase. This latter observation may be one reason why normal, contact-inhibited cells do not express UVER as rapidly as faster growing, less contact-inhibited cells. (author)

Host cell subversion by Toxoplasma GRA16, an exported dense granule protein that targets the host cell nucleus and alters gene expression.

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Bougdour, Alexandre; Durandau, Eric; Brenier-Pinchart, Marie-Pierre; Ortet, Philippe; Barakat, Mohamed; Kieffer, Sylvie; Curt-Varesano, Aurélie; Curt-Bertini, Rose-Laurence; Bastien, Olivier; Coute, Yohann; Pelloux, Hervé; Hakimi, Mohamed-Ali

2013-04-17

After invading host cells, Toxoplasma gondii multiplies within a parasitophorous vacuole (PV) that is maintained by parasite proteins secreted from organelles called dense granules. Most dense granule proteins remain within the PV, and few are known to access the host cell cytosol. We identify GRA16 as a dense granule protein that is exported through the PV membrane and reaches the host cell nucleus, where it positively modulates genes involved in cell-cycle progression and the p53 tumor suppressor pathway. GRA16 binds two host enzymes, the deubiquitinase HAUSP and PP2A phosphatase, which exert several functions, including regulation of p53 and the cell cycle. GRA16 alters p53 levels in a HAUSP-dependent manner and induces nuclear translocation of the PP2A holoenzyme. Additionally, certain GRA16-deficient strains exhibit attenuated virulence, indicating the importance of these host alterations in pathogenesis. Therefore, GRA16 represents a potentially emerging subfamily of exported dense granule proteins that modulate host function. Copyright © 2013 Elsevier Inc. All rights reserved.

Syndecan-2 promotes perineural invasion and cooperates with K-ras to induce an invasive pancreatic cancer cell phenotype

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De Oliveira Tiago

2012-04-01

Full Text Available Abstract Background We have identified syndecan-2 as a protein potentially involved in perineural invasion of pancreatic adenocarcinoma (PDAC cells. Methods Syndecan-2 (SDC-2 expression was analyzed in human normal pancreas, chronic pancreatitis and PDAC tissues. Functional in vitro assays were carried out to determine its role in invasion, migration and signaling. Results SDC-2 was expressed in the majority of the tested pancreatic cancer cell lines while it was upregulated in nerve-invasive PDAC cell clones. There were 2 distinct expression patterns of SDC-2 in PDAC tissue samples: SDC-2 positivity in the cancer cell cytoplasm and a peritumoral expression. Though SDC-2 silencing (using specific siRNA oligonucleotides did not affect anchorage-dependent growth, it significantly reduced cell motility and invasiveness in the pancreatic cancer cell lines T3M4 and Su8686. On the transcriptional level, migration-and invasion-associated genes were down-regulated following SDC-2 RNAi. Furthermore, SDC-2 silencing reduced K-ras activity, phosphorylation of Src and - further downstream - phosphorylation of ERK2 while levels of the putative SDC-2 signal transducer p120GAP remained unaltered. Conclusion SDC-2 is a novel (perineural invasion-associated gene in PDAC which cooperates with K-ras to induce a more invasive phenotype.

Cell cycle-dependent Rho GTPase activity dynamically regulates cancer cell motility and invasion in vivo.

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Kagawa, Yoshinori; Matsumoto, Shinji; Kamioka, Yuji; Mimori, Koshi; Naito, Yoko; Ishii, Taeko; Okuzaki, Daisuke; Nishida, Naohiro; Maeda, Sakae; Naito, Atsushi; Kikuta, Junichi; Nishikawa, Keizo; Nishimura, Junichi; Haraguchi, Naotsugu; Takemasa, Ichiro; Mizushima, Tsunekazu; Ikeda, Masataka; Yamamoto, Hirofumi; Sekimoto, Mitsugu; Ishii, Hideshi; Doki, Yuichiro; Matsuda, Michiyuki; Kikuchi, Akira; Mori, Masaki; Ishii, Masaru

2013-01-01

The mechanism behind the spatiotemporal control of cancer cell dynamics and its possible association with cell proliferation has not been well established. By exploiting the intravital imaging technique, we found that cancer cell motility and invasive properties were closely associated with the cell cycle. In vivo inoculation of human colon cancer cells bearing fluorescence ubiquitination-based cell cycle indicator (Fucci) demonstrated an unexpected phenomenon: S/G2/M cells were more motile and invasive than G1 cells. Microarray analyses showed that Arhgap11a, an uncharacterized Rho GTPase-activating protein (RhoGAP), was expressed in a cell-cycle-dependent fashion. Expression of ARHGAP11A in cancer cells suppressed RhoA-dependent mechanisms, such as stress fiber formation and focal adhesion, which made the cells more prone to migrate. We also demonstrated that RhoA suppression by ARHGAP11A induced augmentation of relative Rac1 activity, leading to an increase in the invasive properties. RNAi-based inhibition of Arhgap11a reduced the invasion and in vivo expansion of cancers. Additionally, analysis of human specimens showed the significant up-regulation of Arhgap11a in colon cancers, which was correlated with clinical invasion status. The present study suggests that ARHGAP11A, a cell cycle-dependent RhoGAP, is a critical regulator of cancer cell mobility and is thus a promising therapeutic target in invasive cancers.

Cell cycle-dependent Rho GTPase activity dynamically regulates cancer cell motility and invasion in vivo.

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Yoshinori Kagawa

Full Text Available The mechanism behind the spatiotemporal control of cancer cell dynamics and its possible association with cell proliferation has not been well established. By exploiting the intravital imaging technique, we found that cancer cell motility and invasive properties were closely associated with the cell cycle. In vivo inoculation of human colon cancer cells bearing fluorescence ubiquitination-based cell cycle indicator (Fucci demonstrated an unexpected phenomenon: S/G2/M cells were more motile and invasive than G1 cells. Microarray analyses showed that Arhgap11a, an uncharacterized Rho GTPase-activating protein (RhoGAP, was expressed in a cell-cycle-dependent fashion. Expression of ARHGAP11A in cancer cells suppressed RhoA-dependent mechanisms, such as stress fiber formation and focal adhesion, which made the cells more prone to migrate. We also demonstrated that RhoA suppression by ARHGAP11A induced augmentation of relative Rac1 activity, leading to an increase in the invasive properties. RNAi-based inhibition of Arhgap11a reduced the invasion and in vivo expansion of cancers. Additionally, analysis of human specimens showed the significant up-regulation of Arhgap11a in colon cancers, which was correlated with clinical invasion status. The present study suggests that ARHGAP11A, a cell cycle-dependent RhoGAP, is a critical regulator of cancer cell mobility and is thus a promising therapeutic target in invasive cancers.

The thioredoxin system in breast cancer cell invasion and migration

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Maneet Bhatia

2016-08-01

Full Text Available Metastasis is the most life threatening aspect of breast cancer. It is a multi-step process involving invasion and migration of primary tumor cells with a subsequent colonization of these cells at a secondary location. The aim of the present study was to investigate the role of thioredoxin (Trx1 in the invasion and migration of breast cancer cells and to assess the strength of the association between high levels of Trx1 and thioredoxin reductase (TrxR1 expression with breast cancer patient survival. Our results indicate that the expression of both Trx1 and TrxR1 are statistically significantly increased in breast cancer patient cells compared with paired normal breast tissue from the same patient. Over-expression of Trx1 in MDA-MB-231 breast cancer cell lines enhanced cell invasion in in vitro assays while expression of a redox inactive mutant form of Trx1 (designated 1SS or the antisense mRNA inhibited cell invasion. Addition of exogenous Trx1 also enhanced cell invasion, while addition of a specific monoclonal antibody that inhibits Trx1 redox function decreased cell invasion. Over-expression of intracellular Trx1 did not increase cell migration but expression of intracellular 1SS inhibited migration. Addition of exogenous Trx1 enhanced cell migration while 1SS had no effect. Treatment with auranofin inhibited TrxR activity, cell migration and clonogenic activity of MDA-MB-231 cells, while increasing reactive oxygen species (ROS levels. Analysis of 25 independent cohorts with 5910 patients showed that Trx1 and TrxR1 were both associated with a poor patient prognosis in terms of overall survival, distant metastasis free survival and disease free survival. Therefore, targeting the Trx system with auranofin or other specific inhibitors may provide improved breast cancer patient outcomes through inhibition of cancer invasion and migration.

HCG-Activated Human Peripheral Blood Mononuclear Cells (PBMC Promote Trophoblast Cell Invasion.

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Nan Yu

Full Text Available Successful embryo implantation and placentation depend on appropriate trophoblast invasion into the maternal endometrial stroma. Human chorionic gonadotropin (hCG is one of the earliest embryo-derived secreted signals in the peripheral blood mononuclear cells (PBMC that abundantly expresses hCG receptors. The aims of this study were to estimate the effect of human embryo-secreted hCG on PBMC function and investigate the role and underlying mechanisms of activated PBMC in trophoblast invasion. Blood samples were collected from women undergoing benign gynecological surgery during the mid-secretory phase. PBMC were isolated and stimulated with or without hCG for 0 or 24 h. Interleukin-1β (IL-1β and leukemia inhibitory factor (LIF expressions in PBMC were detected by enzyme-linked immunosorbent assay and real-time polymerase chain reaction (PCR. The JAR cell line served as a model for trophoblast cells and was divided into four groups: control, hCG only, PBMC only, and PBMC with hCG. JAR cell invasive and proliferative abilities were detected by trans-well and CCK8 assays and matrix metalloproteinase (MMP-2 (MMP-2, MMP-9, vascular endothelial growth factor (VEGF, tissue inhibitor of metalloproteinase (TIMP-1, and TIMP-2 expressions in JAR cells were detected by western blotting and real-time PCR analysis. We found that hCG can remarkably promote IL-1β and LIF promotion in PBMC after 24-h culture. PBMC activated by hCG significantly increased the number of invasive JAR cells in an invasion assay without affecting proliferation, and hCG-activated PBMC significantly increased MMP-2, MMP-9, and VEGF and decreased TIMP-1 and TIMP-2 expressions in JAR cells in a dose-dependent manner. This study demonstrated that hCG stimulates cytokine secretion in human PBMC and could stimulate trophoblast invasion.

Bartonella entry mechanisms into mammalian host cells.

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Eicher, Simone C; Dehio, Christoph

2012-08-01

The Gram-negative genus Bartonella comprises arthropod-borne pathogens that typically infect mammals in a host-specific manner. Bartonella bacilliformis and Bartonella quintana are human-specific pathogens, while several zoonotic bartonellae specific for diverse animal hosts infect humans as an incidental host. Clinical manifestations of Bartonella infections range from mild symptoms to life-threatening disease. Following transmission by blood-sucking arthropods or traumatic contact with infected animals, bartonellae display sequential tropisms towards endothelial and possibly other nucleated cells and erythrocytes, the latter in a host-specific manner. Attachment to the extracellular matrix (ECM) and to nucleated cells is mediated by surface-exposed bacterial adhesins, in particular trimeric autotransporter adhesins (TAAs). The subsequent engulfment of the pathogen into a vacuolar structure follows a unique series of events whereby the pathogen avoids the endolysosomal compartments. For Bartonella henselae and assumingly most other species, the infection process is aided at different steps by Bartonella effector proteins (Beps). They are injected into host cells through the type IV secretion system (T4SS) VirB/D4 and subvert host cellular functions to favour pathogen uptake. Bacterial binding to erythrocytes is mediated by Trw, another T4SS, in a strictly host-specific manner, followed by pathogen-forced uptake involving the IalB invasin and subsequent replication and persistence within a membrane-bound intra-erythrocytic compartment. © 2012 Blackwell Publishing Ltd.

Getting ready for host invasion: elevated expression and action of xyloglucan endotransglucosylases/hydrolases in developing haustoria of the holoparasitic angiosperm Cuscuta.

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Olsen, Stian; Striberny, Bernd; Hollmann, Julien; Schwacke, Rainer; Popper, Zoë; Krause, Kirsten

2016-02-01

Changes in cell walls have been previously observed in the mature infection organ, or haustorium, of the parasitic angiosperm Cuscuta, but are not equally well charted in young haustoria. In this study, we focused on the molecular processes in the early stages of developing haustoria; that is, before the parasite engages in a physiological contact with its host. We describe first the identification of differentially expressed genes in young haustoria whose development was induced by far-red light and tactile stimuli in the absence of a host plant by suppression subtractive hybridization. To improve sequence information and to aid in the identification of the obtained candidates, reference transcriptomes derived from two species of Cuscuta, C. gronovii and C. reflexa, were generated. Subsequent quantitative gene expression analysis with different tissues of C. reflexa revealed that among the genes that were up-regulated in young haustoria, two xyloglucan endotransglucosylase/hydrolase (XTH) genes were highly expressed almost exclusively at the onset of haustorium development. The same expression pattern was also found for the closest XTH homologues from C. gronovii. In situ assays for XTH-specific action suggested that xyloglucan endotransglucosylation was most pronounced in the cell walls of the swelling area of the haustorium facing the host plant, but was also detectable in later stages of haustoriogenesis. We propose that xyloglucan remodelling by Cuscuta XTHs prepares the parasite for host infection and possibly aids the invasive growth of the haustorium. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Lipids in host-pathogen interactions: pathogens exploit the complexity of the host cell lipidome.

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van der Meer-Janssen, Ynske P M; van Galen, Josse; Batenburg, Joseph J; Helms, J Bernd

2010-01-01

Lipids were long believed to have a structural role in biomembranes and a role in energy storage utilizing cellular lipid droplets and plasma lipoproteins. Research over the last decades has identified an additional role of lipids in cellular signaling, membrane microdomain organization and dynamics, and membrane trafficking. These properties make lipids an attractive target for pathogens to modulate host cell processes in order to allow their survival and replication. In this review we will summarize the often ingenious strategies of pathogens to modify the lipid homeostasis of host cells, allowing them to divert cellular processes. To this end pathogens take full advantage of the complexity of the lipidome. The examples are categorized in generalized and emerging principles describing the involvement of lipids in host-pathogen interactions. Several pathogens are described that simultaneously induce multiple changes in the host cell signaling and trafficking mechanisms. Elucidation of these pathogen-induced changes may have important implications for drug development. The emergence of high-throughput lipidomic techniques will allow the description of changes of the host cell lipidome at the level of individual molecular lipid species and the identification of lipid biomarkers.

Host–parasite interactions during a biological invasion: The fate of lungworms (Rhabdias spp. inside native and novel anuran hosts

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Felicity B.L. Nelson

2015-08-01

Full Text Available The cane toad invasion in Australia provides a robust opportunity to clarify the infection process in co-evolved versus de novo host–parasite interactions. We investigated these infection dynamics through histological examination following experimental infections of metamorphs of native frogs (Cyclorana australis and cane toads (Rhinella marina with Rhabdias hylae (the lungworm found in native frogs and Rhabdias pseudosphaerocephala (the lungworm found in cane toads. Cane toads reared under continuous exposure to infective larvae of the frog lungworm were examined after periods of 2, 6, 10 and 15 days. Additionally, both toads and frogs were exposed for 24 h to larvae of either the toad or the frog lungworm, and examined 2, 5, 10 and 20 days post-treatment. R. hylae (frog lungworms entered cane toads and migrated through the body but were not found in the target tissue, the lungs. Larvae of both lungworm species induced inflammation in both types of hosts, although the immune response (relative numbers of different cell types differed between hosts and between parasite species. Co-evolution has modified the immune response elicited by infection and (perhaps for that reason has enhanced the parasite's ability to survive and to reach the host's lungs.

Structural Basis of the Interaction of a Trypanosoma cruzi Surface Molecule Implicated in Oral Infection with Host Cells and Gastric Mucin

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Cortez, Cristian; Yoshida, Nobuko; Bahia, Diana; Sobreira, Tiago J.P.

2012-01-01

Host cell invasion and dissemination within the host are hallmarks of virulence for many pathogenic microorganisms. As concerns Trypanosoma cruzi, which causes Chagas disease, the insect vector-derived metacyclic trypomastigotes (MT) initiate infection by invading host cells, and later blood trypomastigotes disseminate to diverse organs and tissues. Studies with MT generated in vitro and tissue culture-derived trypomastigotes (TCT), as counterparts of insect-borne and bloodstream parasites, have implicated members of the gp85/trans-sialidase superfamily, MT gp82 and TCT Tc85-11, in cell invasion and interaction with host factors. Here we analyzed the gp82 structure/function characteristics and compared them with those previously reported for Tc85-11. One of the gp82 sequences identified as a cell binding site consisted of an α-helix, which connects the N-terminal β-propeller domain to the C-terminal β-sandwich domain where the second binding site is nested. In the gp82 structure model, both sites were exposed at the surface. Unlike gp82, the Tc85-11 cell adhesion sites are located in the N-terminal β-propeller region. The gp82 sequence corresponding to the epitope for a monoclonal antibody that inhibits MT entry into target cells was exposed on the surface, upstream and contiguous to the α-helix. Located downstream and close to the α-helix was the gp82 gastric mucin binding site, which plays a central role in oral T. cruzi infection. The sequences equivalent to Tc85-11 laminin-binding sites, which have been associated with the parasite ability to overcome extracellular matrices and basal laminae, was poorly conserved in gp82, compatible with its reduced capacity to bind laminin. Our study indicates that gp82 is structurally suited for MT to initiate infection by the oral route, whereas Tc85-11, with its affinity for laminin, would facilitate the parasite dissemination through diverse organs and tissues. PMID:22860068

Counting Legionella cells within single amoeba host cells

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Here we present the first attempt to quantify L. pneumophila cell numbers within individual amoebae hosts that may be released into engineered water systems. The maximum numbers of culturable L. pneumophila cells grown within Acanthamoeba polyphaga and Naegleria fowleri were 134...

Molecular basis of mammalian cell invasion by Trypanosoma cruzi

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Nobuko Yoshida

2006-03-01

Full Text Available Establishment of infection by Trypanosoma cruzi, the agent of Chagas' disease, depends on a series of events involving interactions of diverse parasite molecules with host components. Here we focus on the mechanisms of target cell invasion by metacyclic trypomastigotes (MT and mammalian tissue culture trypomastigotes (TCT. During MT or TCT internalization, signal transduction pathways are activated both in the parasite and the target cell, leading to Ca2+ mobilization. For cell adhesion, MT engage surface glycoproteins, such as gp82 and gp35/50, which are Ca2+ signal-inducing molecules. In T. cruzi isolates that enter host cells in gp82-mediated manner, parasite protein tyrosine kinase as well as phospholipase C are activated, and Ca2+ is released from I P3-sensitive stores, whereas in T. cruzi isolates that attach to target cells mainly through gp35/50, the signaling pathway involving adenylate cyclase appears to be stimulated, with Ca2+ release from acidocalciosomes. In addition, T. cruzi isolate-dependent inhibitory signals, mediated by MT-specific gp90, may be triggered both in the host cell and the parasite. The repertoire of TCT molecules implicated in cell invasion includes surface glycoproteins of gp85 family, with members containing binding sites for laminin and cytokeratin 18, enzymes such as cruzipain, trans-sialidase, and an oligopeptidase B that generates a Ca2+-agonist from a precursor molecule.O estabelecimento da infecção por Trypanosoma cruzi, o agente da doença de Chagas, depende de uma série de eventos envolvendo interações de diversas moléculas do parasita com componentes do hospedeiro. Focalizamos aqui os mecanismos de invasão celular por tripomastigotas metacíclicos (TM e por tripomastigotas de cultura de tecido (TCT. Durante a internalização de TM ou TCT, vias de transdução de sinal são ativadas tanto no parasita como na célula alvo, acarretando a mobilização de Ca2+. Para adesão, TM utiliza as glicoprote

Fibronectin Modulates Cell Adhesion and Signaling to Promote Single Cell Migration of Highly Invasive Oral Squamous Cell Carcinoma

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Ramos, Grasieli de Oliveira; Bernardi, Lisiane; Lauxen, Isabel; Sant’Ana Filho, Manoel; Horwitz, Alan Rick; Lamers, Marcelo Lazzaron

2016-01-01

Cell migration is regulated by adhesion to the extracellular matrix (ECM) through integrins and activation of small RhoGTPases, such as RhoA and Rac1, resulting in changes to actomyosin organization. During invasion, epithelial-derived tumor cells switch from laminin-enriched basal membrane to collagen and fibronectin-enriched connective tissue. How this switch affects the tumor migration is still unclear. We tested the hypothesis that ECM dictates the invasiveness of Oral Squamous Cell Carcinoma (OSCC). We analyzed the migratory properties of two OSCC lines, a low invasive cell line with high e-cadherin levels (Linv/HE-cad) or a highly invasive cell line with low e-cadherin levels (Hinv/LE-cad), plated on different ECM components. Compared to laminin, fibronectin induced non-directional collective migration and decreased RhoA activity in Linv/HE-cad OSCC. For Hinv/LE-cad OSCC, fibronectin increased Rac1 activity and induced smaller adhesions, resulting in a fast single cell migration in both 2D and 3D environments. Consistent with these observations, human OSCC biopsies exhibited similar changes in cell-ECM adhesion distribution at the invasive front of the tumor, where cells encounter fibronectin. Our results indicate that ECM composition might induce a switch from collective to single cell migration according to tumor invasiveness due to changes in cell-ECM adhesion and the resulting signaling pathways that alter actomyosin organization. PMID:26978651

Fibronectin Modulates Cell Adhesion and Signaling to Promote Single Cell Migration of Highly Invasive Oral Squamous Cell Carcinoma.

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Grasieli de Oliveira Ramos

Full Text Available Cell migration is regulated by adhesion to the extracellular matrix (ECM through integrins and activation of small RhoGTPases, such as RhoA and Rac1, resulting in changes to actomyosin organization. During invasion, epithelial-derived tumor cells switch from laminin-enriched basal membrane to collagen and fibronectin-enriched connective tissue. How this switch affects the tumor migration is still unclear. We tested the hypothesis that ECM dictates the invasiveness of Oral Squamous Cell Carcinoma (OSCC. We analyzed the migratory properties of two OSCC lines, a low invasive cell line with high e-cadherin levels (Linv/HE-cad or a highly invasive cell line with low e-cadherin levels (Hinv/LE-cad, plated on different ECM components. Compared to laminin, fibronectin induced non-directional collective migration and decreased RhoA activity in Linv/HE-cad OSCC. For Hinv/LE-cad OSCC, fibronectin increased Rac1 activity and induced smaller adhesions, resulting in a fast single cell migration in both 2D and 3D environments. Consistent with these observations, human OSCC biopsies exhibited similar changes in cell-ECM adhesion distribution at the invasive front of the tumor, where cells encounter fibronectin. Our results indicate that ECM composition might induce a switch from collective to single cell migration according to tumor invasiveness due to changes in cell-ECM adhesion and the resulting signaling pathways that alter actomyosin organization.

Disruption of endocytic trafficking protein Rab7 impairs invasiveness of cholangiocarcinoma cells.

Science.gov (United States)

Suwandittakul, Nantana; Reamtong, Onrapak; Molee, Pattamaporn; Maneewatchararangsri, Santi; Sutherat, Maleerat; Chaisri, Urai; Wongkham, Sopit; Adisakwattana, Poom

2017-09-07

Alterations and mutations of endo-lysosomal trafficking proteins have been associated with cancer progression. Identification and characterization of endo-lysosomal trafficking proteins in invasive cholangiocarcinoma (CCA) cells may benefit prognosis and drug design for CCA. To identify and characterize endo-lysosomal trafficking proteins in invasive CCA. A lysosomal-enriched fraction was isolated from a TNF-α induced invasive CCA cell line (KKU-100) and uninduced control cells and protein identification was performed with nano-LC MS/MS. Novel lysosomal proteins that were upregulated in invasive CCA cells were validated by real-time RT-PCR. We selected Rab7 for further studies of protein level using western blotting and subcellular localization using immunofluorescence. The role of Rab7 in CCA invasion was determined by siRNA gene knockdown and matrigel transwell assay. Rab7 mRNA and protein were upregulated in invasive CCA cells compared with non-treated controls. Immunofluorescence studies demonstrated that Rab7 was expressed predominantly in invasive CCA cells and was localized in the cytoplasm and lysosomes. Suppression of Rab7 translation significantly inhibited TNF-α-induced cell invasion compared to non-treated control (p= 0.044). Overexpression of Rab7 in CCA cells was associated with cell invasion, supporting Rab7 as a novel candidate for the development of diagnostic and therapeutic strategies for CCA.

Simultaneous transcriptional profiling of bacteria and their host cells.

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Michael S Humphrys

Full Text Available We developed an RNA-Seq-based method to simultaneously capture prokaryotic and eukaryotic expression profiles of cells infected with intracellular bacteria. As proof of principle, this method was applied to Chlamydia trachomatis-infected epithelial cell monolayers in vitro, successfully obtaining transcriptomes of both C. trachomatis and the host cells at 1 and 24 hours post-infection. Chlamydiae are obligate intracellular bacterial pathogens that cause a range of mammalian diseases. In humans chlamydiae are responsible for the most common sexually transmitted bacterial infections and trachoma (infectious blindness. Disease arises by adverse host inflammatory reactions that induce tissue damage & scarring. However, little is known about the mechanisms underlying these outcomes. Chlamydia are genetically intractable as replication outside of the host cell is not yet possible and there are no practical tools for routine genetic manipulation, making genome-scale approaches critical. The early timeframe of infection is poorly understood and the host transcriptional response to chlamydial infection is not well defined. Our simultaneous RNA-Seq method was applied to a simplified in vitro model of chlamydial infection. We discovered a possible chlamydial strategy for early iron acquisition, putative immune dampening effects of chlamydial infection on the host cell, and present a hypothesis for Chlamydia-induced fibrotic scarring through runaway positive feedback loops. In general, simultaneous RNA-Seq helps to reveal the complex interplay between invading bacterial pathogens and their host mammalian cells and is immediately applicable to any bacteria/host cell interaction.

Mapping host-species abundance of three major exotic forest pests

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Randall S. Morin; Andrew M. Liebhold; Eugene R. Luzader; Andrew J. Lister; Kurt W. Gottschalk; Daniel B. Twardus

2005-01-01

Periodically over the last century, forests of the Eastern United States devastated by invasive pests. We used existing data to predict the geographical extent of future damage from beech bark disease (BBD), hemlock woolly adelgid (HWA), and gypsy moth. The distributions of host species of these alien pests were mapped in 1-km2 cells by interpolating host basal area/ha...

The Pseudomonas aeruginosa lectin LecA triggers host cell signalling by glycosphingolipid-dependent phosphorylation of the adaptor protein CrkII.

Science.gov (United States)

Zheng, Shuangshuang; Eierhoff, Thorsten; Aigal, Sahaja; Brandel, Annette; Thuenauer, Roland; de Bentzmann, Sophie; Imberty, Anne; Römer, Winfried

2017-07-01

The human pathogen Pseudomonas aeruginosa induces phosphorylation of the adaptor protein CrkII by activating the non-receptor tyrosine kinase Abl to promote its uptake into host cells. So far, specific factors of P. aeruginosa, which induce Abl/CrkII signalling, are entirely unknown. In this research, we employed human lung epithelial cells H1299, Chinese hamster ovary cells and P. aeruginosa wild type strain PAO1 to study the invasion process of P. aeruginosa into host cells by using microbiological, biochemical and cell biological approaches such as Western Blot, immunofluorescence microscopy and flow cytometry. Here, we demonstrate that the host glycosphingolipid globotriaosylceramide, also termed Gb3, represents a signalling receptor for the P. aeruginosa lectin LecA to induce CrkII phosphorylation at tyrosine 221. Alterations in Gb3 expression and LecA function correlate with CrkII phosphorylation. Interestingly, phosphorylation of CrkII Y221 occurs independently of Abl kinase. We further show that Src family kinases transduce the signal induced by LecA binding to Gb3, leading to Crk Y221 phosphorylation. In summary, we identified LecA as a bacterial factor, which utilizes a so far unrecognized mechanism for phospho-CrkII Y221 induction by binding to the host glycosphingolipid receptor Gb3. The LecA/Gb3 interaction highlights the potential of glycolipids to mediate signalling processes across the plasma membrane and should be further elucidated to gain deeper insights into this non-canonical mechanism of activating host cell processes. Copyright © 2017 Elsevier B.V. All rights reserved.

Inhibition of Zoledronic Acid on Cell Proliferation and Invasion of Lung Cancer Cell Line 95D

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Mingming LI

2009-03-01

Full Text Available Background and objective Abnormal proliferation and metastasis is the basic characteristic of malignant tumors. The aim of this work is to explore the effects of zoledronic acid on cell proliferation and invasion in lung cancer cell line 95D. Methods The effect of zoledrnic acid (ZOL on proliferation of lung cancer cell line 95D was detected by MTT. The expression of proliferation and invasion-relation genes and proteins were detected by Western blot, RT-PCR and immunofluorescence. Changes of invasion of lung cancer cell numbers were measured by polycarbonates coated with Matrigel. Results ZOL could inhibit the proliferation of lung cancer cell line 95D in vitro in a time-dependant and a dose-dependant manner. With time extending after ZOL treated, the mRNA expresion of VEGF, MMP9, MMP2 and protein expression of VEGF, MMP9, ERK1/ ERK2 were decreased. The results of Tanswell invasion showed the numbers of invasive cells were significantly reduced in 95D cells treated with ZOL 4 d and 6 d later. Conclusion ZOL could inhibit cell proliferation and invasion of lung cancer cell line 95D.

The genetic and molecular basis of bacterial invasion of epithelial cells

African Journals Online (AJOL)

Invasion of epithelial cells was demonstrated to be triggered by invasion plasmid antigens B, C, and D ( IpaB, IpaC and IpaD ) which is accomplished by intracellular spread gene icsA. The invasion of epithelial cells by some individual species of bacteria were also reviewed.Yersinia enterocolitica invasiveness was shown ...

Spillover but no spillback of two invasive parasitic copepods from invasive Pacific oysters (

NARCIS (Netherlands)

Goedknegt, M.A.; Schuster, A.-K.; Buschbaum, C.; Gergs, R.; Jung, A.; Luttikhuizen, P.C.; Van der Meer, J.; Troost, K.; Wegner, K.M.; Thieltges, D.W.

2017-01-01

Invasive species can cause indirect effects on native biota by modifying parasite-host interactions and disease occurrence in native species. This study investigated the role of the invasive Pacific oyster (Crassostrea gigas) in potential spillover (co-introduced parasites infect native hosts) and

The invasion of tobacco mosaic virus RNA induces endoplasmic reticulum stress-related autophagy in HeLa cells

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Li, Li; Wang, Li; Xiao, Ruijing; Zhu, Guoguo; Li, Yan; Liu, Changxuan; Yang, Ru; Tang, Zhiqing; Li, Jie; Huang, Wei; Chen, Lang; Zheng, Xiaoling; He, Yuling; Tan, Jinquan

2011-01-01

The ability of human cells to defend against viruses originating from distant species has long been ignored. Owing to the pressure of natural evolution and human exploration, some of these viruses may be able to invade human beings. If their ‘fresh’ host had no defences, the viruses could cause a serious pandemic, as seen with HIV, SARS (severe acute respiratory syndrome) and avian influenza virus that originated from chimpanzees, the common palm civet and birds, respectively. It is unknown whether the human immune system could tolerate invasion with a plant virus. To model such an alien virus invasion, we chose TMV (tobacco mosaic virus) and used human epithelial carcinoma cells (HeLa cells) as its ‘fresh’ host. We established a reliable system for transfecting TMV-RNA into HeLa cells and found that TMV-RNA triggered autophagy in HeLa cells as shown by the appearance of autophagic vacuoles, the conversion of LC3-I (light chain protein 3-I) to LC3-II, the up-regulated expression of Beclin1 and the accumulation of TMV protein on autophagosomal membranes. We observed suspected TMV virions in HeLa cells by TEM (transmission electron microscopy). Furthermore, we found that TMV-RNA was translated into CP (coat protein) in the ER (endoplasmic reticulum) and that TMV-positive RNA translocated from the cytoplasm to the nucleolus. Finally, we detected greatly increased expression of GRP78 (78 kDa glucose-regulated protein), a typical marker of ERS (ER stress) and found that the formation of autophagosomes was closely related to the expanded ER membrane. Taken together, our data indicate that HeLa cells used ERS and ERS-related autophagy to defend against TMV-RNA. PMID:21729006

Invasion of Dendritic Cells, Macrophages and Neutrophils by the Bordetella Adenylate Cyclase Toxin: A Subversive Move to Fool Host Immunity

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Giorgio Fedele

2017-09-01

Full Text Available Adenylate cyclase toxin (CyaA is released in the course of B. pertussis infection in the host’s respiratory tract in order to suppress its early innate and subsequent adaptive immune defense. CD11b-expressing dendritic cells (DC, macrophages and neutrophils are professional phagocytes and key players of the innate immune system that provide a first line of defense against invading pathogens. Recent findings revealed the capacity of B. pertussis CyaA to intoxicate DC with high concentrations of 3′,5′-cyclic adenosine monophosphate (cAMP, which ultimately skews the host immune response towards the expansion of Th17 cells and regulatory T cells. CyaA-induced cAMP signaling swiftly incapacitates opsonophagocytosis, oxidative burst and NO-mediated killing of bacteria by neutrophils and macrophages. The subversion of host immune responses by CyaA after delivery into DC, macrophages and neutrophils is the subject of this review.

Host-feeding patterns of native Culex pipiens and invasive Aedes albopictus mosquitoes (Diptera: Culicidae) in urban zones from Barcelona, Spain.

Science.gov (United States)

Muñnoz, Joaquin; Eritja, Roger; Alcaide, Miguel; Montalvo, Tomás; Soriguer, Ramón C; Figuerola, Jordi

2011-07-01

The feeding patterns of haematophagous arthropods are of major importance in the amplification and transmission of infectious disease agents to vertebrate hosts, including humans. The establishment of new vector populations in nonnative range might alter transmission networks. The Asian tiger mosquito Aedes albopictus (Skuse) represents an example of how an invasive species can alter the risk of viral transmission to humans. Blood meal molecular identification from two sympatric mosquito species (the invasive Ae. albopictus and the native Culex pipiens) was carried out by polymerase chain reaction-based methods. Samples were collected in Barcelona metropolitan area, Spain, from June to October 2009 as part of a monitoring-control program. Blood meals were identified to the species level in 30 Ae. albopictus and 43 Cx. pipiens. Ae. albopictus acquired blood exclusively from human hosts (100%), whereas Cx. pipiens fed on a diversity of avian and mammalian hosts, including 35.7% of blood meals from humans. Based on mosquito diet, our results suggest that the Ae. albopictus invasion in Spain might increase the risk of virus transmission to humans and could support local outbreaks of imported tropical viruses such as dengue and chikungunya. However, in the studied area, the presence of this invasive species would have a negligible effect on the transmission of zoonotic agents such as West Nile virus. However, Cx. pipiens could amplify and transmit West Nile virus, but avian contribution to its diet was lower than that reported in North America. Feeding patterns of these mosquito species may help to understand the flavivirus outbreaks recently reported in southwestern Europe.

Inhibition of host cell protein synthesis by UV-inactivated poliovirus

International Nuclear Information System (INIS)

Helentjaris, T.; Ehrenfeld, E.

1977-01-01

The ability of poliovirus that was irradiated with UV light at energies up to 2,160 ergs/mm 2 to subsequently inhibit host cell protein synthesis was measured. The inactivation of the host cell shutoff function followed one-hit kinetics. Increasing irradiation did not affect the rate of inhibition until the multiplicity of infection after irradiation was reduced to approximately 1 PFU/cell. At higher functional multiplicities, the rate was unchanged, but an increasing lag before the onset of inhibition was observed with increasing irradiation. The energy levels required to inactivate virus-induced inhibition of host cell protein synthesis suggest that damage to virus RNA rather than to virus capsid proteins is responsible for the loss of function. When the inactivation of host cell shutoff was compared with the inactivation of other viral functions by UV irradiation, it correlated exactly with the loss of infectivity but not with other viral functions measured. Guanidine treatment, which prevents detectable viral RNA and protein synthesis, completely inhibited host cell shutoff by low multiplicities of unirradiated virus infection but not higher multiplicities. When a high multiplicity of virus was first reduced to a low titer by irradiation, host cell shutoff was still evident in the presence of guanidine. The results demonstrate that the complete inhibition of host cell protein synthesis can be accomplished by one infectious viral genome per cell

In vitro invasion of small-cell lung cancer cell lines correlates with expression of epidermal growth factor receptor

DEFF Research Database (Denmark)

Damstrup, L; Rude Voldborg, B; Spang-Thomsen, M

1998-01-01

receptor (EGFR) in a panel of 21 small-cell lung cancer (SCLC) cell lines. We have previously reported that ten of these cell lines expressed EGFR protein detected by radioreceptor and affinity labelling assays. In 11 small-cell lung cancer (SCLC) cell lines, EGFR mRNA was detected by Northern blot...... analysis. In vitro invasion in a Boyden chamber assay was found in all EGFR-positive cell lines, whereas no invasion was detected in the EGFR-negative cell lines. Quantification of the in vitro invasion in 12 selected SCLC cell lines demonstrated that, in the EGFR-positive cell lines, between 5% and 16......-PCR). However, in vitro invasive SCLC cell lines could not be distinguished from non-invasive cell lines based on the expression pattern of these molecules. In six SCLC cell lines, in vitro invasion was also determined in the presence of the EGFR-neutralizing monoclonal antibody mAb528. The addition...

Role of HLA-G1 in trophoblast cell proliferation, adhesion and invasion

International Nuclear Information System (INIS)

Jiang, Feng; Zhao, Hongxi; Wang, Li; Guo, Xinyu; Wang, Xiaohong; Yin, Guowu; Hu, Yunsheng; Li, Yi; Yao, Yuanqing

2015-01-01

Trophoblast cells are important in embryo implantation and fetomaternal tolerance. HLA-G is specifically expressed at the maternal–fetal interface and is a regulator in pregnancy. The aim of the present study was to detect the effect of HLA-G1 on trophoblast cell proliferation, adhesion, and invasion. Human trophoblast cell lines (JAR and HTR-8/SVneo cells) were infected with HLA-G1-expressing lentivirus. After infection, HLA-G1 expression of the cells was detected by western blotting. Cell proliferation was detected by the BrdU assay. The cell cycle and apoptosis of JAR and HTR-8/SVneo cells was measured by flow cytometry (FCM). The invasion of the cells under different conditions was detected by the transwell invasion chamber assay. HLA-G1 didn't show any significant influence on the proliferation, apoptosis, adhesion, and invasion of trophocytes in normal culture conditions. However, HLA-G1 inhibited JAR and HTR-8/SVneo cells invasion induced by hepatocyte growth factor (HGF) under normal oxygen conditions. In conditions of hypoxia, HLA-G1 couldn't inhibit the induction of cell invasion by HGF. HLA-G1 is not an independent factor for regulating the trophocytes. It may play an indirect role in embryo implantation and formation of the placenta. - Highlights: • HLA-G1 could not influence trophocytes under normal conditions. • HLA-G1 inhibited cell invasion induced by HGF under normal oxygen condition. • HLA-G1 could not influence cell invasion under hypoxia conditions

Role of HLA-G1 in trophoblast cell proliferation, adhesion and invasion

Energy Technology Data Exchange (ETDEWEB)

Jiang, Feng, E-mail: jiangfeng1161@163.com [Department of Gynecology and Obstetrics, Tangdu Hospital, The Fourth Military Medical University, 569 Xinsi Road, Baqiao District, Xi' an 710038 (China); Zhao, Hongxi [Department of Gynecology and Obstetrics, Tangdu Hospital, The Fourth Military Medical University, 569 Xinsi Road, Baqiao District, Xi' an 710038 (China); Wang, Li [Department of Gynecology and Obstetrics, The Chinese PLA General Hospital, 28 Fuxing Road, Haidian District, Beijing 100853 (China); Guo, Xinyu [Assisted Reproductive Center, General Hospital of Guangzhou Military Command, Guangzhou 510010 (China); Wang, Xiaohong; Yin, Guowu [Department of Gynecology and Obstetrics, Tangdu Hospital, The Fourth Military Medical University, 569 Xinsi Road, Baqiao District, Xi' an 710038 (China); Hu, Yunsheng [Department of Orthopedics, Tangdu Hospital, The Fourth Military Medical University, Xi' an 710038 (China); Li, Yi [Department of Gynecology and Obstetrics, Tangdu Hospital, The Fourth Military Medical University, 569 Xinsi Road, Baqiao District, Xi' an 710038 (China); Yao, Yuanqing, E-mail: yuanqingyaoxa@163.com [Department of Gynecology and Obstetrics, The Chinese PLA General Hospital, 28 Fuxing Road, Haidian District, Beijing 100853 (China)

2015-02-27

Trophoblast cells are important in embryo implantation and fetomaternal tolerance. HLA-G is specifically expressed at the maternal–fetal interface and is a regulator in pregnancy. The aim of the present study was to detect the effect of HLA-G1 on trophoblast cell proliferation, adhesion, and invasion. Human trophoblast cell lines (JAR and HTR-8/SVneo cells) were infected with HLA-G1-expressing lentivirus. After infection, HLA-G1 expression of the cells was detected by western blotting. Cell proliferation was detected by the BrdU assay. The cell cycle and apoptosis of JAR and HTR-8/SVneo cells was measured by flow cytometry (FCM). The invasion of the cells under different conditions was detected by the transwell invasion chamber assay. HLA-G1 didn't show any significant influence on the proliferation, apoptosis, adhesion, and invasion of trophocytes in normal culture conditions. However, HLA-G1 inhibited JAR and HTR-8/SVneo cells invasion induced by hepatocyte growth factor (HGF) under normal oxygen conditions. In conditions of hypoxia, HLA-G1 couldn't inhibit the induction of cell invasion by HGF. HLA-G1 is not an independent factor for regulating the trophocytes. It may play an indirect role in embryo implantation and formation of the placenta. - Highlights: • HLA-G1 could not influence trophocytes under normal conditions. • HLA-G1 inhibited cell invasion induced by HGF under normal oxygen condition. • HLA-G1 could not influence cell invasion under hypoxia conditions.

The histone deacetylase inhibitor butyrate inhibits melanoma cell invasion of Matrigel.

Science.gov (United States)

Kuwajima, Akiko; Iwashita, Jun; Murata, Jun; Abe, Tatsuya

2007-01-01

Histone deacetylase (HDAC) inhibitors have anticancer effects. Their effects on expression of cell adhesion molecules might be related to their effects on tumor cell invasion. Murine B16-BL6 cells were treated with the HDAC inhibitors, butyrate or trichostatin A. Melanoma cell invasion of the artificial basement membrane, Matrigel, was examined by Transwell chamber assay. Butyrate as well as trichostatin A inhibited the cell growth mainly by arresting the cell cycle. The cell invasion of Matrigel was inhibited by butyrate and trichostatin A. The butyrate treatment increased the cell-cell aggregation, although neither E-cadherin nor N-cadherin mRNA were up-regulated. Both mRNA expression and protein levels of the immunoglobulin superfamily cell adhesion molecules, Mel-CAM and L1-CAM, were increased in the butyrate-treated cells. The HDAC inhibitor butyrate blocked the B16-BL6 melanoma cell invasion of Matrigel, although it increased the expression of Mel-CAM and L1-CAM which are important to the metastatic potential.

Methods for production of proteins in host cells

Science.gov (United States)

Donnelly, Mark; Joachimiak, Andrzej

2004-01-13

The present invention provides methods for the production of proteins, particularly toxic proteins, in host cells. The invention provides methods which use a fusion protein comprising a chaperonin binding domain in host cells induced or regulated to have increased levels of chaperonin which binds the chaperonin binding domain.

Immunoproteome of Aspergillus fumigatus Using Sera of Patients with Invasive Aspergillosis

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Emylli D. Virginio

2014-08-01

Full Text Available Invasive aspergillosis is a life-threatening lung or systemic infection caused by the opportunistic mold Aspergillus fumigatus. The disease affects mainly immunocompromised hosts, and patients with hematological malignances or who have been submitted to stem cell transplantation are at high risk. Despite the current use of Platelia™ Aspergillus as a diagnostic test, the early diagnosis of invasive aspergillosis remains a major challenge in improving the prognosis of the disease. In this study, we used an immunoproteomic approach to identify proteins that could be putative candidates for the early diagnosis of invasive aspergillosis. Antigenic proteins expressed in the first steps of A. fumigatus germination occurring in a human host were revealed using 2-D Western immunoblots with the serum of patients who had previously been classified as probable and proven for invasive aspergillosis. Forty antigenic proteins were identified using mass spectrometry (MS/MS. A BLAST analysis revealed that two of these proteins showed low homology with proteins of either the human host or etiological agents of other invasive fungal infections. To our knowledge, this is the first report describing specific antigenic proteins of A. fumigatus germlings that are recognized by sera of patients with confirmed invasive aspergillosis who were from two separate hospital units.

Establishment and Characterization of a Tumor Stem Cell-Based Glioblastoma Invasion Model.

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Stine Skov Jensen

Full Text Available Glioblastoma is the most frequent and malignant brain tumor. Recurrence is inevitable and most likely connected to tumor invasion and presence of therapy resistant stem-like tumor cells. The aim was therefore to establish and characterize a three-dimensional in vivo-like in vitro model taking invasion and tumor stemness into account.Glioblastoma stem cell-like containing spheroid (GSS cultures derived from three different patients were established and characterized. The spheroids were implanted in vitro into rat brain slice cultures grown in stem cell medium and in vivo into brains of immuno-compromised mice. Invasion was followed in the slice cultures by confocal time-lapse microscopy. Using immunohistochemistry, we compared tumor cell invasion as well as expression of proliferation and stem cell markers between the models.We observed a pronounced invasion into brain slice cultures both by confocal time-lapse microscopy and immunohistochemistry. This invasion closely resembled the invasion in vivo. The Ki-67 proliferation indexes in spheroids implanted into brain slices were lower than in free-floating spheroids. The expression of stem cell markers varied between free-floating spheroids, spheroids implanted into brain slices and tumors in vivo.The established invasion model kept in stem cell medium closely mimics tumor cell invasion into the brain in vivo preserving also to some extent the expression of stem cell markers. The model is feasible and robust and we suggest the model as an in vivo-like model with a great potential in glioma studies and drug discovery.

Phenotypic interactions between tree hosts and invasive forest pathogens in the light of globalization and climate change

Science.gov (United States)

2016-01-01

Invasive pathogens can cause considerable damage to forest ecosystems. Lack of coevolution is generally thought to enable invasive pathogens to bypass the defence and/or recognition systems in the host. Although mostly true, this argument fails to predict intermittent outcomes in space and time, underlining the need to include the roles of the environment and the phenotype in host–pathogen interactions when predicting disease impacts. We emphasize the need to consider host–tree imbalances from a phenotypic perspective, considering the lack of coevolutionary and evolutionary history with the pathogen and the environment, respectively. We describe how phenotypic plasticity and plastic responses to environmental shifts may become maladaptive when hosts are faced with novel pathogens. The lack of host–pathogen and environmental coevolution are aligned with two global processes currently driving forest damage: globalization and climate change, respectively. We suggest that globalization and climate change act synergistically, increasing the chances of both genotypic and phenotypic imbalances. Short moves on the same continent are more likely to be in balance than if the move is from another part of the world. We use Gremmeniella abietina outbreaks in Sweden to exemplify how host–pathogen phenotypic interactions can help to predict the impacts of specific invasive and emergent diseases. This article is part of the themed issue ‘Tackling emerging fungal threats to animal health, food security and ecosystem resilience’. PMID:28080981

Getting what is served? Feeding ecology influencing parasite-host interactions in invasive round goby Neogobius melanostomus.

Science.gov (United States)

Emde, Sebastian; Kochmann, Judith; Kuhn, Thomas; Plath, Martin; Klimpel, Sven

2014-01-01

Freshwater ecosystems are increasingly impacted by alien invasive species which have the potential to alter various ecological interactions like predator-prey and host-parasite relationships. Here, we simultaneously examined predator-prey interactions and parasitization patterns of the highly invasive round goby (Neogobius melanostomus) in the rivers Rhine and Main in Germany. A total of 350 N. melanostomus were sampled between June and October 2011. Gut content analysis revealed a broad prey spectrum, partly reflecting temporal and local differences in prey availability. For the major food type (amphipods), species compositions were determined. Amphipod fauna consisted entirely of non-native species and was dominated by Dikerogammarus villosus in the Main and Echinogammarus trichiatus in the Rhine. However, the availability of amphipod species in the field did not reflect their relative abundance in gut contents of N. melanostomus. Only two metazoan parasites, the nematode Raphidascaris acus and the acanthocephalan Pomphorhynchus sp., were isolated from N. melanostomus in all months, whereas unionid glochidia were only detected in June and October in fish from the Main. To analyse infection pathways, we examined 17,356 amphipods and found Pomphorhynchus sp. larvae only in D. villosus in the river Rhine at a prevalence of 0.15%. Dikerogammarus villosus represented the most important amphipod prey for N. melanostomus in both rivers but parasite intensities differed between rivers, suggesting that final hosts (large predatory fishes) may influence host-parasite dynamics of N. melanostomus in its introduced range.

Development of hyper osmotic resistant CHO host cells for enhanced antibody production.

Science.gov (United States)

Kamachi, Yasuharu; Omasa, Takeshi

2018-04-01

Cell culture platform processes are generally employed to shorten the duration of new product development. A fed-batch process with continuous feeding is a conventional platform process for monoclonal antibody production using Chinese hamster ovary (CHO) cells. To establish a simplified platform process, the feeding method can be changed from continuous feed to bolus feed. However, this change induces a rapid increase of osmolality by the bolus addition of nutrients. The increased osmolality suppresses cell culture growth, and the final product concentration is decreased. In this study, osmotic resistant CHO host cells were developed to attain a high product concentration. To establish hyper osmotic resistant CHO host cells, CHO-S host cells were passaged long-term in a hyper osmotic basal medium. There were marked differences in cell growth of the original and established host cells under iso- (328 mOsm/kg) or hyper-osmolality (over 450 mOsm/kg) conditions. Cell growth of the original CHO host cells was markedly decreased by the induction of osmotic stress, whereas cell growth of the hyper osmotic resistant CHO host cells was not affected. The maximum viable cell concentration of hyper osmotic resistant CHO host cells was 132% of CHO-S host cells after the induction of osmotic stress. Moreover, the hyper osmotic resistant characteristic of established CHO host cells was maintained even after seven passages in iso-osmolality basal medium. The use of hyper osmotic resistance CHO host cells to create a monoclonal antibody production cell line might be a new approach to increase final antibody concentrations with a fed-batch process. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Prognostic significance of tumor budding and single cell invasion in gastric adenocarcinoma

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Che K

2017-02-01

Full Text Available Keying Che,1,* Yang Zhao,2,3,* Xiao Qu,1 Zhaofei Pang,1 Yang Ni,4 Tiehong Zhang,4 Jiajun Du,1,5 Hongchang Shen4 1Institute of Oncology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, 2Department of Breast Surgery, Key Laboratory of Breast Cancer in Shanghai, Collaborative Innovation Center of Cancer Medicine, Fudan University Shanghai Cancer Center, 3Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 4Department of Oncology, Shandong Provincial Hospital Affiliated to Shandong University, 5Department of Thoracic Surgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, People’s Republic of China *These authors contributed equally to this work Purpose: Gastric carcinoma (GC is a highly aggressive cancer and one of the leading causes of cancer-related deaths worldwide. Histopathological evaluation pertaining to invasiveness is likely to provide additional information in relation to patient outcome. In this study, we aimed to evaluate the prognostic significance of tumor budding and single cell invasion in gastric adenocarcinoma.Materials and methods: Hematoxylin and eosin-stained slides generated from 296 gastric adenocarcinoma patients with full clinical and pathological and follow-up information were systematically reviewed. The patients were grouped on the basis of tumor budding, single cell invasion, large cell invasion, mitotic count, and fibrosis. The association between histopathological parameters, different classification systems, and overall survival (OS was statistically analyzed.Results: Among the 296 cases that were analyzed, high-grade tumor budding was observed in 49.0% (145 of them. Single cell invasion and large cell invasion were observed in 62.8% (186 and 16.9% (50 of the cases, respectively. Following univariate analysis, patients with high-grade tumor budding had shorter OS than those with low-grade tumor budding (hazard ratio [HR]: 2.260, P<0

Rapamycin causes growth arrest and inhibition of invasion in human chondrosarcoma cells.

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Song, Jian; Wang, Xiaobo; Zhu, Jiaxue; Liu, Jun

2016-01-01

Chondrosarcoma is a highly malignant tumor that is characterized by a potent capacity to invade locally and cause distant metastasis and notable for its lack of response to conventional chemotherapy or radiotherapy. Rapamycin, the inhibitor of mammalian target of rapamycin (mTOR), is a valuable drug with diverse clinical applications and regulates many cellular processes. However, the effects of rapamycin on cell growth and invasion of human chondrosarcoma cells are not well known. We determined the effect of rapamycin on cell proliferation, cell cycle arrest and invasion by using MTS, flow cytometry and invasion assays in two human chondrosarcoma cell lines, SW1353 and JJ012. Cell cycle regulatory and invasion-related genes' expression analysis was performed by quantitative RT-PCR (qRT-PCR). We also evaluated the effect of rapamycin on tumor growth by using mice xenograph models. Rapamycin significantly inhibited the cell proliferation, induced cell cycle arrest and decreased the invasion ability of human chondrosarcoma cells. Meanwhile, rapamycin modulated the cell cycle regulatory and invasion-related genes' expression. Furthermore, the tumor growth of mice xenograph models with human chondrosarcoma cells was significantly inhibited by rapamycin. These results provided further insight into the role of rapamycin in chondrosarcoma. Therefore, rapamycin targeted therapy may be a potential treatment strategy for chondrosarcoma.

Kupffer cell complement receptor clearance function and host defense.

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Loegering, D J

1986-01-01

Kupffer cells are well known to be important for normal host defense function. The development of methods to evaluate the in vivo function of specific receptors on Kupffer cells has made it possible to assess the role of these receptors in host defense. The rationale for studying complement receptors is based on the proposed important role of these receptors in host defense and on the observation that the hereditary deficiency of a complement receptor is associated with recurrent severe bacterial infections. The studies reviewed here demonstrate that forms of injury that are associated with depressed host defense including thermal injury, hemorrhagic shock, trauma, and surgery also cause a decrease in complement receptor clearance function. This decrease in Kupffer cell receptor clearance function was shown not to be the result of depressed hepatic blood flow or depletion of complement components. Complement receptor function was also depressed following the phagocytosis of particulates that are known to depress Kupffer cell host defense function. Endotoxemia and bacteremia also were associated with a depression of complement receptor function. Complement receptor function was experimentally depressed in uninjured animals by the phagocytosis of IgG-coated erythrocytes. There was a close association between the depression of complement receptor clearance function and increased susceptibility to the lethal effects of endotoxin and bacterial infection. These studies support the hypotheses that complement receptors on Kupffer cells are important for normal host defense and that depression of the function of these receptors impairs host defense.

Plasmodium falciparum erythrocyte invasion: combining function with immune evasion.

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Gavin J Wright

2014-03-01

Full Text Available All the symptoms and pathology of malaria are caused by the intraerythrocytic stages of the Plasmodium parasite life cycle. Because Plasmodium parasites cannot replicate outside a host cell, their ability to recognize and invade erythrocytes is an essential step for both parasite survival and malaria pathogenesis. This makes invasion a conceptually attractive vaccine target, especially because it is one of the few stages when the parasite is directly exposed to the host humoral immune system. This apparent vulnerability, however, has been countered by the parasite, which has evolved sophisticated molecular mechanisms to evade the host immune response so that parasites asymptomatically replicate within immune individuals. These mechanisms include the expansion of parasite invasion ligands, resulting in multiple and apparently redundant invasion "pathways", highly polymorphic parasite surface proteins that are immunologically distinct, and parasite proteins which are poorly immunogenic. These formidable defences have so far thwarted attempts to develop an effective blood-stage vaccine, leading many to question whether there really is an exploitable chink in the parasite's immune evasion defences. Here, we review recent advances in the molecular understanding of the P. falciparum erythrocyte invasion field, discuss some of the challenges that have so far prevented the development of blood-stage vaccines, and conclude that the parasite invasion ligand RH5 represents an essential pinch point that might be vulnerable to vaccination.

Host cells and methods for production of isobutanol

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Anthony, Larry Cameron; He, Hongxian; Huang, Lixuan Lisa; Okeefe, Daniel P.; Kruckeberg, Arthur Leo; Li, Yougen; Maggio-Hall, Lori; McElvain, Jessica; Nelson, Mark J.; Patnaik, Ranjan; Rothman, Steven Cary

2017-10-17

Provided herein are recombinant yeast host cells and methods for their use for production of isobutanol. Yeast host cells provided comprise an isobutanol biosynthetic pathway and at least one of reduced or eliminated aldehyde dehydrogenase activity, reduced or eliminated acetolactate reductase activity; or a heterologous polynucleotide encoding a polypeptide having ketol-acid reductoisomerase activity.

Alterations in integrin expression modulates invasion of pancreatic cancer cells.

LENUS (Irish Health Repository)

Walsh, Naomi

2009-01-01

BACKGROUND: Factors mediating the invasion of pancreatic cancer cells through the extracellular matrix (ECM) are not fully understood. METHODS: In this study, sub-populations of the human pancreatic cancer cell line, MiaPaCa-2 were established which displayed differences in invasion, adhesion, anoikis, anchorage-independent growth and integrin expression. RESULTS: Clone #3 displayed higher invasion with less adhesion, while Clone #8 was less invasive with increased adhesion to ECM proteins compared to MiaPaCa-2. Clone #8 was more sensitive to anoikis than Clone #3 and MiaPaCa-2, and displayed low colony-forming efficiency in an anchorage-independent growth assay. Integrins beta 1, alpha 5 and alpha 6 were over-expressed in Clone #8. Using small interfering RNA (siRNA), integrin beta1 knockdown in Clone #8 cells increased invasion through matrigel and fibronectin, increased motility, decreased adhesion and anoikis. Integrin alpha 5 and alpha 6 knockdown also resulted in increased motility, invasion through matrigel and decreased adhesion. CONCLUSION: Our results suggest that altered expression of integrins interacting with different extracellular matrixes may play a significant role in suppressing the aggressive invasive phenotype. Analysis of these clonal populations of MiaPaCa-2 provides a model for investigations into the invasive properties of pancreatic carcinoma.

Placental Growth Factor Promotes Ovarian Cancer Cell Invasion via ZEB2

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Ning Song

2016-01-01

Full Text Available Background/Aims: The aggressive manner of ovarian cancer (OVC cells accounts for the majority of its lethality. Recently, we have shown that placental growth factor (PLGF promotes metastases of OVC cells through miR-543-regulated MMP7. In the current study, we analyzed the effects of PLGF on another cell invasion associated protein, ZEB2, in OVC cells. Methods: The PLGF and ZEB2 levels in OVC tissues were compared to the paired adjacent non-tumor ovary tissue. We modified ZEB2 levels in OVC cells, and examined its effects on PLGF mRNA and protein levels by RT-qPCR and by Western blot, respectively. We also modified PLGF levels in OVC cells, and examined its effects on ZEB2 mRNA and protein levels by RT-qPCR and by Western blot, respectively. Then, we examined the cell invasiveness in PLGF-modified OVC cells in a transwell cell invasion assay. Finally, we used specific signal pathway inhibitors to treat PLGF-modified OVC cells and examined the effects on ZEB2 activation. Results: PLGF and ZEB2 levels were both significantly increased in OVC tissues, compared to the paired adjacent non-tumor ovary tissue. The PLGF and ZEB2 levels were strongly correlated. ZEB2 modification did not alter PLGF levels. Overexpression of PLGF in OVC cells significantly increased ZEB2 levels and cell invasiveness, while PLGF depletion in OVC cells significantly decreased ZEB2 levels and cell invasiveness. Application of a specific MAPK-p38 inhibitor, but not application of specific inhibitors for MAPK-p42/p44, PI3k/Akt, or JNK signaling pathways, to PLGF-overexpressing OVC cells substantially abolished the PLGF-induced ZEB2 activation. Conclusion: PLGF enhances OVC cell invasion through MAPK-p38-dependent activation of ZEB2.

Effect of cell-phone radiofrequency on angiogenesis and cell invasion in human head and neck cancer cells.

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Alahmad, Yaman M; Aljaber, Mohammed; Saleh, Alaaeldin I; Yalcin, Huseyin C; Aboulkassim, Tahar; Yasmeen, Amber; Batist, Gerald; Moustafa, Ala-Eddin Al

2018-05-13

Today, the cell phone is the most widespread technology globally. However, the outcome of cell-phone radiofrequency on head and neck cancer progression has not yet been explored. The chorioallantoic membrane (CAM) and human head and neck cancer cell lines, FaDu and SCC25, were used to explore the outcome of cell-phone radiofrequency on angiogenesis, cell invasion, and colony formation of head and neck cancer cells, respectively. Western blot analysis was used to investigate the impact of the cell phone on the regulation of E-cadherin and Erk1/Erk2 genes. Our data revealed that cell-phone radiofrequency promotes angiogenesis of the CAM. In addition, the cell phone enhances cell invasion and colony formation of human head and neck cancer cells; this is accompanied by a downregulation of E-cadherin expression. More significantly, we found that the cell phone can activate Erk1/Erk2 in our experimental models. Our investigation reveals that cell-phone radiofrequency could enhance head and neck cancer by stimulating angiogenesis and cell invasion via Erk1/Erk2 activation. © 2018 Wiley Periodicals, Inc.

Cutaneous Squamous Cell Carcinoma with Invasion through Ear Cartilage

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Julie Boisen

2016-01-01

Full Text Available Cutaneous squamous cell carcinoma of the ear represents a high-risk tumor location with an increased risk of metastasis and local tissue invasion. However, it is uncommon for these cancers to invade through nearby cartilage. Cartilage invasion is facilitated by matrix metalloproteases, specifically collagenase 3. We present the unusual case of a 76-year-old man with an auricular squamous cell carcinoma that exhibited full-thickness perforation of the scapha cartilage. Permanent sections through the eroded cartilage confirmed tumor invasion extending to the posterior ear skin.

Molecular and Microenvironmental Determinants of Glioma Stem-Like Cell Survival and Invasion

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Alison Roos

2017-06-01

Full Text Available Glioblastoma multiforme (GBM is the most frequent primary brain tumor in adults with a 5-year survival rate of 5% despite intensive research efforts. The poor prognosis is due, in part, to aggressive invasion into the surrounding brain parenchyma. Invasion is a complex process mediated by cell-intrinsic pathways, extrinsic microenvironmental cues, and biophysical cues from the peritumoral stromal matrix. Recent data have attributed GBM invasion to the glioma stem-like cell (GSC subpopulation. GSCs are slowly dividing, highly invasive, therapy resistant, and are considered to give rise to tumor recurrence. GSCs are localized in a heterogeneous cellular niche, and cross talk between stromal cells and GSCs cultivates a fertile environment that promotes GSC invasion. Pro-migratory soluble factors from endothelial cells, astrocytes, macrophages, microglia, and non-stem-like tumor cells can stimulate peritumoral invasion of GSCs. Therefore, therapeutic efforts designed to target the invasive GSCs may enhance patient survival. In this review, we summarize the current understanding of extrinsic pathways and major stromal and immune players facilitating GSC maintenance and survival.

Genetic reprogramming of host cells by bacterial pathogens.

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Tran Van Nhieu, Guy; Arbibe, Laurence

2009-10-29

During the course of infection, pathogens often induce changes in gene expression in host cells and these changes can be long lasting and global or transient and of limited amplitude. Defining how, when, and why bacterial pathogens reprogram host cells represents an exciting challenge that opens up the opportunity to grasp the essence of pathogenesis and its molecular details.

Bystander Host Cell Killing Effects of Clostridium perfringens Enterotoxin

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Archana Shrestha

2016-12-01

Full Text Available Clostridium perfringens enterotoxin (CPE binds to claudin receptors, e.g., claudin-4, and then forms a pore that triggers cell death. Pure cultures of host cells that do not express claudin receptors, e.g., fibroblasts, are unaffected by pathophysiologically relevant CPE concentrations in vitro. However, both CPE-insensitive and CPE-sensitive host cells are present in vivo. Therefore, this study tested whether CPE treatment might affect fibroblasts when cocultured with CPE-sensitive claudin-4 fibroblast transfectants or Caco-2 cells. Under these conditions, immunofluorescence microscopy detected increased death of fibroblasts. This cytotoxic effect involved release of a toxic factor from the dying CPE-sensitive cells, since it could be reproduced using culture supernatants from CPE-treated sensitive cells. Supernatants from CPE-treated sensitive cells, particularly Caco-2 cells, were found to contain high levels of membrane vesicles, often containing a CPE species. However, most cytotoxic activity remained in those supernatants even after membrane vesicle depletion, and CPE was not detected in fibroblasts treated with supernatants from CPE-treated sensitive cells. Instead, characterization studies suggest that a major cytotoxic factor present in supernatants from CPE-treated sensitive cells may be a 10- to 30-kDa host serine protease or require the action of that host serine protease. Induction of caspase-3-mediated apoptosis was found to be important for triggering release of the cytotoxic factor(s from CPE-treated sensitive host cells. Furthermore, the cytotoxic factor(s in these supernatants was shown to induce a caspase-3-mediated killing of fibroblasts. This bystander killing effect due to release of cytotoxic factors from CPE-treated sensitive cells could contribute to CPE-mediated disease.

Mesenchymal stem cells promote cell invasion and migration and autophagy-induced epithelial-mesenchymal transition in A549 lung adenocarcinoma cells.

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Luo, Dan; Hu, Shiyuan; Tang, Chunlan; Liu, Guoxiang

2018-03-01

Mesenchymal stem cells (MSCs) are recruited into the tumour microenvironment and promote tumour growth and metastasis. Tumour microenvironment-induced autophagy is considered to suppress primary tumour formation by impairing migration and invasion. Whether these recruited MSCs regulate tumour autophagy and whether autophagy affects tumour growth are controversial. Our data showed that MSCs promote autophagy activation, reactive oxygen species production, and epithelial-mesenchymal transition (EMT) as well as increased migration and invasion in A549 cells. Decreased expression of E-cadherin and increased expression of vimentin and Snail were observed in A549 cells cocultured with MSCs. Conversely, MSC coculture-mediated autophagy positively promoted tumour EMT. Autophagy inhibition suppressed MSC coculture-mediated EMT and reduced A549 cell migration and invasion slightly. Furthermore, the migratory and invasive abilities of A549 cells were additional increased when autophagy was further enhanced by rapamycin treatment. Taken together, this work suggests that microenvironments containing MSCs can promote autophagy activation for enhancing EMT; MSCs also increase the migratory and invasive abilities of A549 lung adenocarcinoma cells. Mesenchymal stem cell-containing microenvironments and MSC-induced autophagy signalling may be potential targets for blocking lung cancer cell migration and invasion. Copyright © 2018 John Wiley & Sons, Ltd.

Implications of Rho GTPase signaling in glioma cell invasion and tumor progression

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Shannon Patricia Fortin Ensign

2013-10-01

Full Text Available Glioblastoma (GB is the most malignant of primary adult brain tumors, characterized by a highly locally-invasive cell population, as well as abundant proliferative cells, neoangiogenesis, and necrosis. Clinical intervention with chemotherapy or radiation may either promote or establish an environment for manifestation of invasive behavior. Understanding the molecular drivers of invasion in the context of glioma progression may be insightful in directing new treatments for patients with GB. Here, we review current knowledge on Rho family GTPases, their aberrant regulation in GB, and their effect on GB cell invasion and tumor progression. Rho GTPases are modulators of cell migration through effects on actin cytoskeleton rearrangement; in non-neoplastic tissue, expression and activation of Rho GTPases are normally under tight regulation. In GB, Rho GTPases are deregulated, often via hyperactivity or overexpression of their activators, Rho GEFs. Downstream effectors of Rho GTPases have been shown to promote invasiveness and, importantly, glioma cell survival. The study of aberrant Rho GTPase signaling in GB is thus an important investigation of cell invasion as well as treatment resistance and disease progression.

CD155/PVR plays a key role in cell motility during tumor cell invasion and migration

International Nuclear Information System (INIS)

Sloan, Kevin E; Ilag, Leodevico L; Jay, Daniel G; Eustace, Brenda K; Stewart, Jean K; Zehetmeier, Carol; Torella, Claudia; Simeone, Marina; Roy, Jennifer E; Unger, Christine; Louis, David N

2004-01-01

Invasion is an important early step of cancer metastasis that is not well understood. Developing therapeutics to limit metastasis requires the identification and validation of candidate proteins necessary for invasion and migration. We developed a functional proteomic screen to identify mediators of tumor cell invasion. This screen couples Fluorophore Assisted Light Inactivation (FALI) to a scFv antibody library to systematically inactivate surface proteins expressed by human fibrosarcoma cells followed by a high-throughput assessment of transwell invasion. Using this screen, we have identified CD155 (the poliovirus receptor) as a mediator of tumor cell invasion through its role in migration. Knockdown of CD155 by FALI or by RNAi resulted in a significant decrease in transwell migration of HT1080 fibrosarcoma cells towards a serum chemoattractant. CD155 was found to be highly expressed in multiple cancer cell lines and primary tumors including glioblastoma (GBM). Knockdown of CD155 also decreased migration of U87MG GBM cells. CD155 is recruited to the leading edge of migrating cells where it colocalizes with actin and αv-integrin, known mediators of motility and adhesion. Knockdown of CD155 also altered cellular morphology, resulting in cells that were larger and more elongated than controls when plated on a Matrigel substrate. These results implicate a role for CD155 in mediating tumor cell invasion and migration and suggest that CD155 may contribute to tumorigenesis

Melanotransferrin induces human melanoma SK-Mel-28 cell invasion in vivo

International Nuclear Information System (INIS)

Bertrand, Yanick; Demeule, Michel; Michaud-Levesque, Jonathan; Beliveau, Richard

2007-01-01

The expression of melanotransferrin (MTf), a membrane-bound glycoprotein highly expressed in melanomas, is correlated with tumor vascularization and progression, suggesting a proinvasive function associated with MTf in malignant tumors. To test this hypothesis, we silenced MTf in human melanoma SK-MEL-28 cells using small interfering RNA (siRNA) and examined the plasmin activity and invasiveness of MTf-silenced melanoma. In vitro, the siRNA-mediated MTf knockdown inhibited by 58% the cell surface activation of plasminogen into plasmin. In addition, decreased expression of MTf in melanoma cells reduced cell migration. In vivo, we used a nude mice invasion model in which tissue factor (TF) induces vascular [ 125 I]-fibrin deposition following injection. Using this metastasis model, the invasive potential of MTf-silenced cells into the lungs was reduced by fivefold. Altogether, these findings strongly suggest that MTf overexpression in melanoma cells contributes to tumor progession by stimulating plasmin generation as well as cell migration and invasion

Positive feedback between mycorrhizal fungi and plants influences plant invasion success and resistance to invasion.

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Zhang, Qian; Yang, Ruyi; Tang, Jianjun; Yang, Haishui; Hu, Shuijin; Chen, Xin

2010-08-24

Negative or positive feedback between arbuscular mycorrhizal fungi (AMF) and host plants can contribute to plant species interactions, but how this feedback affects plant invasion or resistance to invasion is not well known. Here we tested how alterations in AMF community induced by an invasive plant species generate feedback to the invasive plant itself and affect subsequent interactions between the invasive species and its native neighbors. We first examined the effects of the invasive forb Solidago canadensis L. on AMF communities comprising five different AMF species. We then examined the effects of the altered AMF community on mutualisms formed with the native legume forb species Kummerowia striata (Thunb.) Schindl. and on the interaction between the invasive and native plants. The host preferences of the five AMF were also assessed to test whether the AMF form preferred mutualistic relations with the invasive and/or the native species. We found that S. canadensis altered AMF spore composition by increasing one AMF species (Glomus geosporum) while reducing Glomus mosseae, which is the dominant species in the field. The host preference test showed that S. canadensis had promoted the abundance of AMF species (G. geosporum) that most promoted its own growth. As a consequence, the altered AMF community enhanced the competitiveness of invasive S. canadensis at the expense of K. striata. Our results demonstrate that the invasive S. canadensis alters soil AMF community composition because of fungal-host preference. This change in the composition of the AMF community generates positive feedback to the invasive S. canadensis itself and decreases AM associations with native K. striata, thereby making the native K. striata less dominant.

Positive feedback between mycorrhizal fungi and plants influences plant invasion success and resistance to invasion.

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Qian Zhang

2010-08-01

Full Text Available Negative or positive feedback between arbuscular mycorrhizal fungi (AMF and host plants can contribute to plant species interactions, but how this feedback affects plant invasion or resistance to invasion is not well known. Here we tested how alterations in AMF community induced by an invasive plant species generate feedback to the invasive plant itself and affect subsequent interactions between the invasive species and its native neighbors. We first examined the effects of the invasive forb Solidago canadensis L. on AMF communities comprising five different AMF species. We then examined the effects of the altered AMF community on mutualisms formed with the native legume forb species Kummerowia striata (Thunb. Schindl. and on the interaction between the invasive and native plants. The host preferences of the five AMF were also assessed to test whether the AMF form preferred mutualistic relations with the invasive and/or the native species. We found that S. canadensis altered AMF spore composition by increasing one AMF species (Glomus geosporum while reducing Glomus mosseae, which is the dominant species in the field. The host preference test showed that S. canadensis had promoted the abundance of AMF species (G. geosporum that most promoted its own growth. As a consequence, the altered AMF community enhanced the competitiveness of invasive S. canadensis at the expense of K. striata. Our results demonstrate that the invasive S. canadensis alters soil AMF community composition because of fungal-host preference. This change in the composition of the AMF community generates positive feedback to the invasive S. canadensis itself and decreases AM associations with native K. striata, thereby making the native K. striata less dominant.

Analysis of Invasion Dynamics of Matrix-Embedded Cells in a Multisample Format.

Science.gov (United States)

Van Troys, Marleen; Masuzzo, Paola; Huyck, Lynn; Bakkali, Karima; Waterschoot, Davy; Martens, Lennart; Ampe, Christophe

2018-01-01

In vitro tests of cancer cell invasion are the "first line" tools of preclinical researchers for screening the multitude of chemical compounds or cell perturbations that may aid in halting or treating cancer malignancy. In order to have predictive value or to contribute to designing personalized treatment regimes, these tests need to take into account the cancer cell environment and measure effects on invasion in sufficient detail. The in vitro invasion assays presented here are a trade-off between feasibility in a multisample format and mimicking the complexity of the tumor microenvironment. They allow testing multiple samples and conditions in parallel using 3D-matrix-embedded cells and deal with the heterogeneous behavior of an invading cell population in time. We describe the steps to take, the technical problems to tackle and useful software tools for the entire workflow: from the experimental setup to the quantification of the invasive capacity of the cells. The protocol is intended to guide researchers to standardize experimental set-ups and to annotate their invasion experiments in sufficient detail. In addition, it provides options for image processing and a solution for storage, visualization, quantitative analysis, and multisample comparison of acquired cell invasion data.

Establishment and Characterization of a Tumor Stem Cell-Based Glioblastoma Invasion Model

DEFF Research Database (Denmark)

Jensen, Stine Skov; Meyer, Morten; Petterson, Stine Asferg

2016-01-01

AIMS: Glioblastoma is the most frequent and malignant brain tumor. Recurrence is inevitable and most likely connected to tumor invasion and presence of therapy resistant stem-like tumor cells. The aim was therefore to establish and characterize a three-dimensional in vivo-like in vitro model taking...... invasion and tumor stemness into account. METHODS: Glioblastoma stem cell-like containing spheroid (GSS) cultures derived from three different patients were established and characterized. The spheroids were implanted in vitro into rat brain slice cultures grown in stem cell medium and in vivo into brains...... of immuno-compromised mice. Invasion was followed in the slice cultures by confocal time-lapse microscopy. Using immunohistochemistry, we compared tumor cell invasion as well as expression of proliferation and stem cell markers between the models. RESULTS: We observed a pronounced invasion into brain slice...

Surface-associated plasminogen binding of Cryptococcus neoformans promotes extracellular matrix invasion.

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Jamal Stie

2009-06-01

Full Text Available The fungal pathogen Cryptococcus neoformans is a leading cause of illness and death in persons with predisposing factors, including: malignancies, solid organ transplants, and corticosteroid use. C. neoformans is ubiquitous in the environment and enters into the lungs via inhalation, where it can disseminate through the bloodstream and penetrate the central nervous system (CNS, resulting in a difficult to treat and often-fatal infection of the brain, called meningoencephalitis. Plasminogen is a highly abundant protein found in the plasma component of blood and is necessary for the degradation of fibrin, collagen, and other structural components of tissues. This fibrinolytic system is utilized by cancer cells during metastasis and several pathogenic species of bacteria have been found to manipulate the host plasminogen system to facilitate invasion of tissues during infection by modifying the activation of this process through the binding of plasminogen at their surface.The invasion of the brain and the central nervous system by penetration of the protective blood-brain barrier is a prerequisite to the establishment of meningoencephalitis by the opportunistic fungal pathogen C. neoformans. In this study, we examined the ability of C. neoformans to subvert the host plasminogen system to facilitate tissue barrier invasion. Through a combination of biochemical, cell biology, and proteomic approaches, we have shown that C. neoformans utilizes the host plasminogen system to cross tissue barriers, providing support for the hypothesis that plasminogen-binding may contribute to the invasion of the blood-brain barrier by penetration of the brain endothelial cells and underlying matrix. In addition, we have identified the cell wall-associated proteins that serve as plasminogen receptors and characterized both the plasminogen-binding and plasmin-activation potential for this significant human pathogen.The results of this study provide evidence for the

The miR-599 promotes non-small cell lung cancer cell invasion via SATB2

International Nuclear Information System (INIS)

Tian, Wenjun; Wang, Guanghai; Liu, Yiqing; Huang, Zhenglan; Zhang, Caiqing; Ning, Kang; Yu, Cuixiang; Shen, Yajuan; Wang, Minghui; Li, Yuantang; Wang, Yong; Zhang, Bingchang; Zhao, Yaoran

2017-01-01

MicroRNAs (miRNAs) play important roles in the pathogenesis of many types of cancers by negatively regulating gene expression at posttranscriptional level. Here, we identified that miR-599 is up-regulated in non-small cell lung cancer (NSCLC) patients. It promoted NSCLC cell proliferation by negatively regulating SATB2. In NSCLC cell lines, CCK-8 proliferation assay indicated that the cell proliferation is promoted by miR-599 mimics. Transwell assay showed that miR-599 mimics promoted the invasion and migration of NSCLC cells. Luciferase assays confirmed that miR-599 directly binds to the 3'untranslated region of SATB2, and western blotting showed that miR-599 suppresses the expression of SATB2 at the protein level. This study indicates that miR-599 promotes proliferation and invasion of NSCLC cell lines via SATB2. The miR-599 may represent a potential therapeutic target for NSCLC treatment. - Highlights: • miR-599 is up-regulated in NSCLC. • miR-599 promotes the proliferation and invasion of NSCLC cells. • miR-599 inhibitors inhibits the proliferation and invasion of NSCLC cells. • miR-599 targets 3′ UTR of SATB2 in NSCLC cells. • miR-599 inhibits SATB2 in NSCLC cells.

Oral chronic graft-versus-host disease: analysis of dendritic cells subpopulations*

Science.gov (United States)

Botari, Clara Marino Espricigo; Nunes, Adauto José Ferreira; de Souza, Mair Pedro; Orti-Raduan, Érica Sinara Lenharo; Salvio, Ana Gabriela

2014-01-01

The graft-versus-host disease is the major cause of morbidity and mortality in patients who have undergone hematopoietic stem cell transplantation. Aiming at contributing to the understanding of the role of myeloid and plasmacytoid dendritic cells, and natural killer cells in chronic graft-versus-host disease, we examined biopsies of jugal mucosa of 26 patients with acute myeloid leukemia who had undergone allogenic hematopoietic stem cell transplantation. Half of these patients developed oral chronic graft-versus-host disease. Microscopic sections were immunohistochemically stained for anti-CD1a, anti-CD123 and anti-CD56. We calculated the number of immunostained cells in the corium per square millimeter and applied the Mann-Whitney test. Results showed a statistically significant increase of myeloid dendritic cells (CD1a+; p=0,02) and natural killer cells (CD56; p=0,04) in patients with oral chronic graft-versus-host disease. CD123 immunostaining showed no statistical difference between groups. It was concluded that myeloid dendritic cells and natural killer cells participate in the development of oral chronic graft-versus-host disease. PMID:25054751

Oral chronic graft-versus-host disease: analysis of dendritic cells subpopulations.

Science.gov (United States)

Botari, Clara Marino Espricigo; Nunes, Adauto José Ferreira; Souza, Mair Pedro de; Orti-Raduan, Erica Sinara Lenharo; Salvio, Ana Gabriela

2014-01-01

The graft-versus-host disease is the major cause of morbidity and mortality in patients who have undergone hematopoietic stem cell transplantation. Aiming at contributing to the understanding of the role of myeloid and plasmacytoid dendritic cells, and natural killer cells in chronic graft-versus-host disease, we examined biopsies of jugal mucosa of 26 patients with acute myeloid leukemia who had undergone allogenic hematopoietic stem cell transplantation. Half of these patients developed oral chronic graft-versus-host disease. Microscopic sections were immunohistochemically stained for anti-CD1a, anti-CD123 and anti-CD56. We calculated the number of immunostained cells in the corium per square millimeter and applied the Mann-Whitney test. Results showed a statistically significant increase of myeloid dendritic cells (CD1a+; p=0,02) and natural killer cells (CD56; p=0,04) in patients with oral chronic graft-versus-host disease. CD123 immunostaining showed no statistical difference between groups. It was concluded that myeloid dendritic cells and natural killer cells participate in the development of oral chronic graft-versus-host disease.

Molecular and Genetic Determinants of Glioma Cell Invasion

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Kenta Masui

2017-12-01

Full Text Available A diffusely invasive nature is a major obstacle in treating a malignant brain tumor, “diffuse glioma”, which prevents neurooncologists from surgically removing the tumor cells even in combination with chemotherapy and radiation. Recently updated classification of diffuse gliomas based on distinct genetic and epigenetic features has culminated in a multilayered diagnostic approach to combine histologic phenotypes and molecular genotypes in an integrated diagnosis. However, it is still a work in progress to decipher how the genetic aberrations contribute to the aggressive nature of gliomas including their highly invasive capacity. Here we depict a set of recent discoveries involving molecular genetic determinants of the infiltrating nature of glioma cells, especially focusing on genetic mutations in receptor tyrosine kinase pathways and metabolic reprogramming downstream of common cancer mutations. The specific biology of glioma cell invasion provides an opportunity to explore the genotype-phenotype correlation in cancer and develop novel glioma-specific therapeutic strategies for this devastating disease.

Invasive cancer cells and metastasis

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Mierke, Claudia Tanja

2013-12-01

The physics of cancer is a relatively new emerging field of cancer research. In the last decade it has become a focus of biophysical research as well as becoming a novel focus for classical cancer research. This special section of Physical Biology focusing on invasive cancer cells and metastasis (physical oncology) will give greater insight into the different subfields where physical approaches are being applied to cancer research. This focus on the physical aspects of cancer is necessary because novel approaches in the field of genomics and proteomics have not altered the field of cancer research dramatically, due to the fact that few breakthroughs have been made. It is still not understood why some primary tumors metastasize and thus have a worse outcome compared to others that do not metastasize. As biophysicists, we and others suggest that the mechanical properties of the cancer cells, which possess the ability to transmigrate, are quite different compared to non-metastatic and non-invasive cancer cells. Furthermore, we hypothesize that these cancer cells undergo a selection process within the primary tumor that enables them to weaken their cell-cell adhesions and to alter their cell-matrix adhesions in order to be able to cross the outermost boundary of the primary tumor, as well as the surrounding basement membrane, and to invade the connective tissue. This prerequisite may also help the cancer cells to enter blood or lymph vessels, get transported with the vessel flow and form secondary tumors either within the vessel, directly on the endothelium, or in a different organ after crossing the endothelial lining a second time. This special section begins with a paper by Mark F Coughlin and Jeffrey J Fredberg on the changes in cytoskeletal dynamics and nonlinear rheology due to the metastatic capability of cancer cells from different cancer tissue types such as skin, bladder, prostate and kidney [1]. The hypothesis was that the metastatic outcome is impacted by

Tetraspanin 1 promotes invasiveness of cervical cancer cells.

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Hölters, Sebastian; Anacker, Jelena; Jansen, Lars; Beer-Grondke, Katrin; Dürst, Matthias; Rubio, Ignacio

2013-08-01

Tetraspanins are a heterogeneous group of 4-transmembrane proteins that segregate into so-called tetraspanin-enriched microdomains (TEMs) along with other cell surface proteins such as integrins. TEMs of various types are reportedly involved in the regulation of cell growth, migration and invasion of several tumour cell types, both as suppressors or supporting structures. Tetraspanin 1 (Tspan1, NET-1), a member of the transmembrane 4 superfamily (TM4SF) of tetraspanins, is overexpressed in high-grade cervical intraepithelial neoplasia (CIN) and terminal carcinomas but its precise function in the context of carcinoma of the cervix uteri is not known. Here, we present a comprehensive investigation of the role of tetraspanin 1 in the cervical cancer cell lines SiHa and HeLa. We document that tetraspanin 1 increases the invasive potential of cervical cancer cells, whereas proliferation, growth in soft agar and adhesion are largely unaffected. In line with the latter findings, our data exclude the participation of testraspanin in integrin-mediated activation of focal adhesion kinase (FAK), paxillin and phosphoinositide-3-kinase (PI3K) and in EGFR-dependent signalling to the Ras/Erk pathway. In conclusion, our data argue against a role for tetraspanin 1 as a genuine mediator of cell surface receptor signalling but rather document a role for tetraspanin 1 in the control of cervical cancer cell motility and invasion.

Ezrin mediates c-Myc actions in prostate cancer cell invasion

DEFF Research Database (Denmark)

Chuan, Yin Choy; Iglesias Gato, Diego; Fernandez-Perez, L

2010-01-01

The forced overexpression of c-Myc in mouse prostate and in normal human prostate epithelial cells results in tumor transformation with an invasive phenotype. How c-Myc regulates cell invasion is poorly understood. In this study, we have investigated the interplay of c-Myc and androgens in the re...

Fierce competition between Toxoplasma and Chlamydia for host cell structures in dually infected cells.

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Romano, Julia D; de Beaumont, Catherine; Carrasco, Jose A; Ehrenman, Karen; Bavoil, Patrik M; Coppens, Isabelle

2013-02-01

The prokaryote Chlamydia trachomatis and the protozoan Toxoplasma gondii, two obligate intracellular pathogens of humans, have evolved a similar modus operandi to colonize their host cell and salvage nutrients from organelles. In order to gain fundamental knowledge on the pathogenicity of these microorganisms, we have established a cell culture model whereby single fibroblasts are coinfected by C. trachomatis and T. gondii. We previously reported that the two pathogens compete for the same nutrient pools in coinfected cells and that Toxoplasma holds a significant competitive advantage over Chlamydia. Here we have expanded our coinfection studies by examining the respective abilities of Chlamydia and Toxoplasma to co-opt the host cytoskeleton and recruit organelles. We demonstrate that the two pathogen-containing vacuoles migrate independently to the host perinuclear region and rearrange the host microtubular network around each vacuole. However, Toxoplasma outcompetes Chlamydia to the host microtubule-organizing center to the detriment of the bacterium, which then shifts to a stress-induced persistent state. Solely in cells preinfected with Chlamydia, the centrosomes become associated with the chlamydial inclusion, while the Toxoplasma parasitophorous vacuole displays growth defects. Both pathogens fragment the host Golgi apparatus and recruit Golgi elements to retrieve sphingolipids. This study demonstrates that the productive infection by both Chlamydia and Toxoplasma depends on the capability of each pathogen to successfully adhere to a finely tuned developmental program that aims to remodel the host cell for the pathogen's benefit. In particular, this investigation emphasizes the essentiality of host organelle interception by intravacuolar pathogens to facilitate access to nutrients.

Aboriginal and invasive rats of genus Rattus as hosts of infectious agents.

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Kosoy, Michael; Khlyap, Lyudmila; Cosson, Jean-Francois; Morand, Serge

2015-01-01

From the perspective of ecology of zoonotic pathogens, the role of the Old World rats of the genus Rattus is exceptional. The review analyzes specific characteristics of rats that contribute to their important role in hosting pathogens, such as host-pathogen relations and rates of rat-borne infections, taxonomy, ecology, and essential factors. Specifically the review addresses recent taxonomic revisions within the genus Rattus that resulted from applications of new genetic tools in understanding relationships between the Old World rats and the infectious agents that they carry. Among the numerous species within the genus Rattus, only three species-the Norway rat (R. norvegicus), the black or roof rat (R. rattus), and the Asian black rat (R. tanezumi)-have colonized urban ecosystems globally for a historically long period of time. The fourth invasive species, R. exulans, is limited to tropical Asia-Pacific areas. One of the points highlighted in this review is the necessity to discriminate the roles played by rats as pathogen reservoirs within the land of their original diversification and in regions where only one or few rat species were introduced during the recent human history.

Interaction of KSHV with Host Cell Surface Receptors and Cell Entry

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Mohanan Valiya Veettil

2014-10-01

Full Text Available Virus entry is a complex process characterized by a sequence of events. Since the discovery of KSHV in 1994, tremendous progress has been made in our understanding of KSHV entry into its in vitro target cells. KSHV entry is a complex multistep process involving viral envelope glycoproteins and several cell surface molecules that is utilized by KSHV for its attachment and entry. KSHV has a broad cell tropism and the attachment and receptor engagement on target cells have an important role in determining the cell type-specific mode of entry. KSHV utilizes heparan sulfate, integrins and EphrinA2 molecules as receptors which results in the activation of host cell pre-existing signal pathways that facilitate the subsequent cascade of events resulting in the rapid entry of virus particles, trafficking towards the nucleus followed by viral and host gene expression. KSHV enters human fibroblast cells by dynamin dependant clathrin mediated endocytosis and by dynamin independent macropinocytosis in dermal endothelial cells. Once internalized into endosomes, fusion of the viral envelope with the endosomal membranes in an acidification dependent manner results in the release of capsids which subsequently reaches the nuclear pore vicinity leading to the delivery of viral DNA into the nucleus. In this review, we discuss the principal mechanisms that enable KSHV to interact with the host cell surface receptors as well as the mechanisms that are required to modulate cell signaling machinery for a successful entry.

Genistein inhibits cell invasion and motility by inducing cell differentiation in murine osteosarcoma cell line LM8.

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Nakamura, Atsushi; Aizawa, Junichi; Sakayama, Kenshi; Kidani, Teruki; Takata, Tomoyo; Norimatsu, Yoshiaki; Miura, Hiromasa; Masuno, Hiroshi

2012-09-26

One of the problems associated with osteosarcoma is the frequent formation of micrometastases in the lung prior to diagnosis because the development of metastatic lesions often causes a fatal outcome. Therefore, the prevention of pulmonary metastases during the early stage of tumor development is critical for the improvement of the prognosis of osteosarcoma patients. In Japan, soy is consumed in a wide variety of forms, such as miso soup and soy sauce. The purpose of this study is to investigate the effect of genistein, an isoflavone found in soy, on the invasive and motile potential of osteosarcoma cells. LM8 cells were treated for 3 days with various concentrations of genistein. The effect of genistein on cell proliferation was determined by DNA measurement in the cultures and 5-bromo-2'-deoxyuridine (BrdU) incorporation study. The assays of cell invasion and motility were performed using the cell culture inserts with either matrigel-coated membranes or uncoated membranes in the invasion chambers. The expression and secretion of MMP-2 were determined by immunohistochemistry and gelatin zymography. The subcellular localization and cellular level of β-catenin were determined by immunofluorescence and Western blot. For examining cell morphology, the ethanol-fixed cells were stained with hematoxylin-eosin (H&E). The expression of osteocalcin mRNA was determined by reverse transcription-polymerase chain reaction (RT-PCR). Genistein dose-dependently inhibits cell proliferation. Genistein-treated cells were less invasive and less motile than untreated cells. The expression and secretion of MMP-2 were lower in the genistein-treated cultures than in the untreated cultures. β-Catenin in untreated cells was located in the cytoplasm and/or nucleus, while in genistein-treated cells it was translocated near to the plasma membrane. The level of β-catenin was higher in genistein-treated cells than in untreated cells. Treatment of LM8 cells with genistein induced morphological

Genistein inhibits cell invasion and motility by inducing cell differentiation in murine osteosarcoma cell line LM8

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Nakamura Atsushi

2012-09-01

Full Text Available Abstract Background One of the problems associated with osteosarcoma is the frequent formation of micrometastases in the lung prior to diagnosis because the development of metastatic lesions often causes a fatal outcome. Therefore, the prevention of pulmonary metastases during the early stage of tumor development is critical for the improvement of the prognosis of osteosarcoma patients. In Japan, soy is consumed in a wide variety of forms, such as miso soup and soy sauce. The purpose of this study is to investigate the effect of genistein, an isoflavone found in soy, on the invasive and motile potential of osteosarcoma cells. Methods LM8 cells were treated for 3 days with various concentrations of genistein. The effect of genistein on cell proliferation was determined by DNA measurement in the cultures and 5-bromo-2’-deoxyuridine (BrdU incorporation study. The assays of cell invasion and motility were performed using the cell culture inserts with either matrigel-coated membranes or uncoated membranes in the invasion chambers. The expression and secretion of MMP-2 were determined by immunohistochemistry and gelatin zymography. The subcellular localization and cellular level of β-catenin were determined by immunofluorescence and Western blot. For examining cell morphology, the ethanol-fixed cells were stained with hematoxylin-eosin (H&E. The expression of osteocalcin mRNA was determined by reverse transcription-polymerase chain reaction (RT-PCR. Results Genistein dose-dependently inhibits cell proliferation. Genistein-treated cells were less invasive and less motile than untreated cells. The expression and secretion of MMP-2 were lower in the genistein-treated cultures than in the untreated cultures. β-Catenin in untreated cells was located in the cytoplasm and/or nucleus, while in genistein-treated cells it was translocated near to the plasma membrane. The level of β-catenin was higher in genistein-treated cells than in untreated cells

Effect of lactoferrin protein on red blood cells and macrophages: mechanism of parasite–host interaction

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An

2015-07-01

Full Text Available Namrata Anand,1 Rupinder K Kanwar,2 Mohan Lal Dubey,1 R K Vahishta,3 Rakesh Sehgal,1,* Anita K Verma,4 Jagat R Kanwar2,*1Department of Medical Parasitology, Postgraduate Institute of Medical Education and Research, Chandigarh, India; 2Nanomedicine Laboratory of Immunology and Molecular Biomedical Research, School of Medicine, Molecular and Medical Research Strategic Research Centre, Faculty of Health, Deakin University, Geelong, VIC, Australia; 3Department of Histopathology, Postgraduate Institute of Medical Education and Research, Chandigarh, 4Nanobiotech Laboratory, Department of Zoology, Kirorimal College, University of Delhi, Delhi, India*These authors contributed equally to this workBackground: Lactoferrin is a natural multifunctional protein known to have antitumor, antimicrobial, and anti-inflammatory activity. Apart from its antimicrobial effects, lactoferrin is known to boost the immune response by enhancing antioxidants. Lactoferrin exists in various forms depending on its iron saturation. The present study was done to observe the effect of lactoferrin, isolated from bovine and buffalo colostrum, on red blood cells (RBCs and macrophages (human monocytic cell line-derived macrophages THP1 cells.Methods: Lactoferrin obtained from both species and in different iron saturation forms were used in the present study, and treatment of host cells were given with different forms of lactoferrin at different concentrations. These treated host cells were used for various studies, including morphometric analysis, viability by MTT assay, survivin gene expression, production of reactive oxygen species, phagocytic properties, invasion assay, and Toll-like receptor-4, Toll-like receptor-9, and MDR1 expression, to investigate the interaction between lactoferrin and host cells and the possible mechanism of action with regard to parasitic infections.Results: The mechanism of interaction between host cells and lactoferrin have shown various aspects of gene

Host cell reactivation in mammalian cells

International Nuclear Information System (INIS)

Lytle, C.D.; Benane, S.G.; Stafford, J.E.

1976-01-01

The survival of UV-irradiated herpes simplex virus was determined in cultured Potoroo (a marsupial) and human cells under lighting conditions which promoted photereactivation. Photoreactivation was readily demonstrated for herpes virus in two lines of Potoroo cells with dose reduction factors of 0.7 to 0.8 for ovary cells and 0.5 to 0.7 for kidney cells. Light from Blacklite (near UV) lamps was more effective than from Daylight (mostly visible) lamps, suggesting that near UV radiation was more effecient for photoreactivation in Potoroo cells. The quantitative and qualitative aspects of this photoreactivation were similar to those reported for a similar virus infecting chick embryo cells. UV-survival curves of herpes virus in Potoroo cells indicated a high level of 'dark' host cell reactivation. No photoreactivation was found for UV-irradiated vaccinia virus in Potoroo cells. A similar photoreactivation study was done using special control lighting (lambda>600 nm) and human cells with normal repair and with cells deficient in excision repair (XP). No photoreactivation was found for UV-irradiated herpes virus in either human cell with either Blacklite or Daylight lamps as the sources of photoreactivating light. This result contrasts with a report of photoreactivation for a herpes virus in the same XP cells using incandescent lamps. (author)

Mast cells and eosinophils in invasive breast carcinoma

International Nuclear Information System (INIS)

Amini, Rose-Marie; Aaltonen, Kirsimari; Nevanlinna, Heli; Carvalho, Ricardo; Salonen, Laura; Heikkilä, Päivi; Blomqvist, Carl

2007-01-01

Inflammatory cells in the tumour stroma has gained increasing interest recently. Thus, we aimed to study the frequency and prognostic impact of stromal mast cells and tumour infiltrating eosinophils in invasive breast carcinomas. Tissue microarrays containing 234 cases of invasive breast cancer were prepared and analysed for the presence of stromal mast cells and eosinophils. Tumour infiltrating eosinophils were counted on hematoxylin-eosin slides. Immunostaining for tryptase was done and the total number of mast cells were counted and correlated to the proliferation marker Ki 67, positivity for estrogen and progesterone receptors, clinical parameters and clinical outcome. Stromal mast cells were found to correlate to low grade tumours and estrogen receptor positivity. There was a total lack of eosinophils in breast cancer tumours. A high number of mast cells in the tumours correlated to low-grade tumours and estrogen receptor positivity. Eosinophils are not tumour infiltrating in breast cancers

Functional Assay of Cancer Cell Invasion Potential Based on Mechanotransduction of Focused Ultrasound

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Andrew C. Weitz

2017-08-01

Full Text Available Cancer cells undergo a number of biophysical changes as they transform from an indolent to an aggressive state. These changes, which include altered mechanical and electrical properties, can reveal important diagnostic information about disease status. Here, we introduce a high-throughput, functional technique for assessing cancer cell invasion potential, which works by probing for the mechanically excitable phenotype exhibited by invasive cancer cells. Cells are labeled with fluorescent calcium dye and imaged during stimulation with low-intensity focused ultrasound, a non-contact mechanical stimulus. We show that cells located at the focus of the stimulus exhibit calcium elevation for invasive prostate (PC-3 and DU-145 and bladder (T24/83 cancer cell lines, but not for non-invasive cell lines (BPH-1, PNT1A, and RT112/84. In invasive cells, ultrasound stimulation initiates a calcium wave that propagates from the cells at the transducer focus to other cells, over distances greater than 1 mm. We demonstrate that this wave is mediated by extracellular signaling molecules and can be abolished through inhibition of transient receptor potential channels and inositol trisphosphate receptors, implicating these proteins in the mechanotransduction process. If validated clinically, our technology could provide a means to assess tumor invasion potential in cytology specimens, which is not currently possible. It may therefore have applications in diseases such as bladder cancer, where cytologic diagnosis of tumor invasion could improve clinical decision-making.

Apigenin inhibits HGF-promoted invasive growth and metastasis involving blocking PI3K/Akt pathway and β4 integrin function in MDA-MB-231 breast cancer cells

International Nuclear Information System (INIS)

Lee, W.-J.; Chen, W.-K.; Wang, C.-J.; Lin, W.-L.; Tseng, T.-H.

2008-01-01

Hepatocyte growth factor (HGF) and its receptor, Met, known to control invasive growth program have recently been shown to play crucial roles in the survival of breast cancer patients. The diet-derived flavonoids have been reported to possess anti-invasion properties; however, knowledge on the pharmacological and molecular mechanisms in suppressing HGF/Met-mediated tumor invasion and metastasis is poorly understood. In our preliminary study, we use HGF as an invasive inducer to investigate the effect of flavonoids including apigenin, naringenin, genistein and kaempferol on HGF-dependent invasive growth of MDA-MB-231 human breast cancer cells. Results show that apigenin presents the most potent anti-migration and anti-invasion properties by Boyden chamber assay. Furthermore, apigenin represses the HGF-induced cell motility and scattering and inhibits the HGF-promoted cell migration and invasion in a dose-dependent manner. The effect of apigenin on HGF-induced signaling activation involving invasive growth was evaluated by immunoblotting analysis, it shows that apigenin blocks the HGF-induced Akt phosphorylation but not Met, ERK, and JNK phosphorylation. In addition to MDA-MB-231 cells, apigenin exhibits inhibitory effect on HGF-induced Akt phosphorylation in hepatoma SK-Hep1 cells and lung carcinoma A549 cells. By indirect immunofluorescence microscopy assay, apigenin inhibits the HGF-induced clustering of β4 integrin at actin-rich adhesive site and lamellipodia through PI3K-dependent manner. Treatment of apigenin inhibited HGF-stimulated integrin β4 function including cell-matrix adhesion and cell-endothelial cells adhesion in MDA-MB-231 cells. By Akt-siRNA transfection analysis, it confirmed that apigenin inhibited HGF-promoted invasive growth involving blocking PI3K/Akt pathway. Finally, we evaluated the effect of apigenin on HGF-promoted metastasis by lung colonization of tumor cells in nude mice and organ metastasis of tumor cells in chick embryo. By

miR-146a Suppresses Invasion of Pancreatic Cancer Cells

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Li, Yiwei; VandenBoom, Timothy G.; Wang, Zhiwei; Kong, Dejuan; Ali, Shadan; Philip, Philip A.; Sarkar, Fazlul H.

2010-01-01

The aggressive course of pancreatic cancer is believed to reflect its unusually invasive and metastatic nature, which is associated with epidermal growth factor receptor (EGFR) overexpression and NF-κB activation. MicroRNAs (miRNA) have been implicated in the regulation of various pathobiological processes in cancer, including metastasis in pancreatic cancer and in other human malignancies. In this study, we report lower expression of miR-146a in pancreatic cancer cells compared with normal human pancreatic duct epithelial cells. Reexpression of miR-146a inhibited the invasive capacity of pancreatic cancer cells with concomitant downregulation of EGFR and the NF-κB regulatory kinase interleukin 1 receptor–associated kinase 1 (IRAK-1). Cellular mechanism studies revealed crosstalk between EGFR, IRAK-1, IκBα, NF-κB, and MTA-2, a transcription factor that regulates metastasis. Treatment of pancreatic cancer cells with the natural products 3,3′-diinodolylmethane (DIM) or isoflavone, which increased miR-146a expression, caused a downregulation of EGFR, MTA-2, IRAK-1, and NF-κB, resulting in an inhibition of pancreatic cancer cell invasion. Our findings reveal DIM and isoflavone as nontoxic activators of a miRNA that can block pancreatic cancer cell invasion and metastasis, offering starting points to design novel anticancer agents. PMID:20124483

Proteins involved in invasion of human red blood cells by malaria parasites

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Ewa Jaśkiewicz

2010-11-01

Full Text Available Malaria is a disease caused by parasites of Plasmodium species. It is responsible for around 1-2 million deaths annually, mainly children under the age of 5. It occurs mainly in tropical and subtropical areas.Malaria is caused by five Plasmodium species:[i] P. falciparum, P. malariae, P. vivax, P. knowlesi[/i] and [i]P. ovale[/i]. Mosquitoes spread the disease by biting humans. The malaria parasite has two stages of development: the human stage and the mosquito stage. The first stage occurs in the human body and is divided into two phases: the liver phase and the blood phase.The invasion of erythrocytes by [i]Plasmodium[/i] merozoites is a multistep process of specific protein interactions between the parasite and red blood cell. The first step is the reversible merozoite attachment to the erythrocyte followed by its apical reorientation, then formation of an irreversible “tight” junction and finally entry into the red cell in a parasitophorous vacuole.The blood phase is supported by a number of proteins produced by the parasite. The merozoite surface GPI-anchored proteins (MSP-1, 2, 4, 5, 8 and 10 assist in the process of recognition of susceptible erythrocytes, apical membrane antigen (AMA-1 may be directly responsible for apical reorientation of the merozoite and apical proteins which function in tight junction formation. These ligands are members of two families: Duffy binding-like (DBL and reticulocyte binding-like (RBL proteins. In [i]Plasmodium[/i] [i]falciparum[/i] the DBL family includes: EBA-175, EBA-140 (BAEBL, EBA-181 (JESEBL, EBA-165 (PEBL and EBL-1 ligands.To date, no effective antimalarial vaccine has been developed, but there are several studies for this purpose. Therefore, it is crucial to understand the molecular basis of host cells invasion by parasites. Major efforts are focused on developing a multiantigenic and multiepitope vaccine preventing all steps of [i]Plasmodium[/i] invasion.

Staphylococcus aureus produces membrane-derived vesicles that induce host cell death.

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Mamata Gurung

Full Text Available Gram-negative bacteria produce outer membrane vesicles that play a role in the delivery of virulence factors to host cells. However, little is known about the membrane-derived vesicles (MVs produced by gram-positive bacteria. The present study examined the production of MVs from Staphylococcus aureus and investigated the delivery of MVs to host cells and subsequent cytotoxicity. Four S. aureus strains tested, two type strains and two clinical isolates, produced spherical nanovesicles during in vitro culture. MVs were also produced during in vivo infection of a clinical S. aureus isolate in a mouse pneumonia model. Proteomic analysis showed that 143 different proteins were identified in the S. aureus-derived MVs. S. aureus MVs were interacted with the plasma membrane of host cells via a cholesterol-rich membrane microdomain and then delivered their component protein A to host cells within 30 min. Intact S. aureus MVs induced apoptosis of HEp-2 cells in a dose-dependent manner, whereas lysed MVs neither delivered their component into the cytosol of host cells nor induced cytotoxicity. In conclusion, this study is the first report that S. aureus MVs are an important vehicle for delivery of bacterial effector molecules to host cells.

Host cells and methods for producing isoprenyl alkanoates

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Lee, Taek Soon; Fortman, Jeffrey L.; Keasling, Jay D.

2015-12-01

The invention provides for a method of producing an isoprenyl alkanoate in a genetically modified host cell. In one embodiment, the method comprises culturing a genetically modified host cell which expresses an enzyme capable of catalyzing the esterification of an isoprenol and a straight-chain fatty acid, such as an alcohol acetyltransferase (AAT), wax ester synthase/diacylglycerol acyltransferase (WS/DGAT) or lipase, under a suitable condition so that the isoprenyl alkanoate is produced.

Host manipulation by cancer cells: Expectations, facts, and therapeutic implications.

Science.gov (United States)

Tissot, Tazzio; Arnal, Audrey; Jacqueline, Camille; Poulin, Robert; Lefèvre, Thierry; Mery, Frédéric; Renaud, François; Roche, Benjamin; Massol, François; Salzet, Michel; Ewald, Paul; Tasiemski, Aurélie; Ujvari, Beata; Thomas, Frédéric

2016-03-01

Similar to parasites, cancer cells depend on their hosts for sustenance, proliferation and reproduction, exploiting the hosts for energy and resources, and thereby impairing their health and fitness. Because of this lifestyle similarity, it is predicted that cancer cells could, like numerous parasitic organisms, evolve the capacity to manipulate the phenotype of their hosts to increase their own fitness. We claim that the extent of this phenomenon and its therapeutic implications are, however, underappreciated. Here, we review and discuss what can be regarded as cases of host manipulation in the context of cancer development and progression. We elaborate on how acknowledging the applicability of these principles can offer novel therapeutic and preventive strategies. The manipulation of host phenotype by cancer cells is one more reason to adopt a Darwinian approach in cancer research. © 2016 WILEY Periodicals, Inc.

Contemporary theories of cervical carcinogenesis: the virus, the host, and the stem cell.

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Crum, C P

2000-03-01

Cervical cancer is a complex disease that, by its association with human papillomavirus (HPV), has elicited research in a broad range of areas pertaining to its basic diagnostic and clinical aspects. The complexity of this association lies not only in the fundamental relationship between virus and cancer but also in its translation to pathologic diagnosis and clinical management. Offshoots from the relationship of virus to pathology include studies targeting the link between papillomavirus infection and cervical epithelial abnormalities, the molecular epidemiology of papillomavirus infection, and the potential use of HPV testing as either a screening technique or a tool for managing women who have Pap smear abnormalities. A second variable that is critical to the pathogenesis of cervical neoplasia is the cervical transformation zone. The wide range of invasive and noninvasive lesion phenotypes associated with HPV infection in this region indicate that not only the virus but also specific host target epithelial cells in the transformation zone play an important part in the development of cervical neoplasia. Further understanding of this relationship between the virus and the host epithelium will hinge on determining the subtypes of epithelial cells in the transformation zone and their phenotypic response to infection. New technologies, such as expression arrays, promise to clarify, if not resolve, the complexity of molecular interactions leading to the multiplicity of tumor phenotypes associated with HPV infection of the uterine cervix.

Invasive orbital aspergillosis in an apparently immunocompetent host without evidence of sinusitis

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Jennifer Primeggia

2012-09-01

Full Text Available Invasive aspergillosis is uncommon in healthy individuals. We report a case of Aspergillus fumigatus orbital cellulitiswith intracranial extension in an apparently immunocompetent patient with a history of benign lymphoid hyperplasiaof the lacrimal gland. A 68 year-old man with no significant past medical history underwent orbitotomy and biopsy of alacrimal gland mass. Pathology showed benign lymphoid hyperplasia of the lacrimal gland and he completed radiationtherapy. Three months after orbitotomy and one month after completion of radiation therapy, he presented with orbitalcellulitis. Brain magnetic resonance imaging demonstrated invasion into the frontal lobe. Clinical and radiographicfindings failed to improve with prolonged antibiotic therapy; transcranial orbitotomy with right frontal craniotomy forabscess drainage and orbit washout was performed. Intraoperative cultures grew Aspergillus fumigatus. The patientcompleted a six month course of therapy with oral voriconazole and has remained free from relapse with long-termfollow-up. Efficacy of voriconazole was guided by serial imaging and voriconazole trough levels. Aspergillus may causeinvasive disease in immunocompetent hosts, even without evidence of sinusitis, and should be considered in the differentialdiagnosis when patients do not demonstrate clinical improvement with antibiotic therapy. J Microbiol Infect Dis2012; 2(3: 113-116Key words: Aspergillosis, orbital cellulitis, brain abscess

Actin cytoskeleton organization, cell surface modification and invasion rate of 5 glioblastoma cell lines differing in PTEN and p53 status

International Nuclear Information System (INIS)

Djuzenova, Cholpon S.; Fiedler, Vanessa; Memmel, Simon; Katzer, Astrid; Hartmann, Susanne; Krohne, Georg; Zimmermann, Heiko; Scholz, Claus-Jürgen; Polat, Bülent; Flentje, Michael

2015-01-01

Glioblastoma cells exhibit highly invasive behavior whose mechanisms are not yet fully understood. The present study explores the relationship between the invasion capacity of 5 glioblastoma cell lines differing in p53 and PTEN status, expression of mTOR and several other marker proteins involved in cell invasion, actin cytoskeleton organization and cell morphology. We found that two glioblastoma lines mutated in both p53 and PTEN genes (U373-MG and SNB19) exhibited the highest invasion rates through the Matrigel or collagen matrix. In DK-MG (p53wt/PTENwt) and GaMG (p53mut/PTENwt) cells, F-actin mainly occurred in the numerous stress fibers spanning the cytoplasm, whereas U87-MG (p53wt/PTENmut), U373-MG and SNB19 (both p53mut/PTENmut) cells preferentially expressed F-actin in filopodia and lamellipodia. Scanning electron microscopy confirmed the abundant filopodia and lamellipodia in the PTEN mutated cell lines. Interestingly, the gene profiling analysis revealed two clusters of cell lines, corresponding to the most (U373-MG and SNB19, i.e. p53 and PTEN mutated cells) and less invasive phenotypes. The results of this study might shed new light on the mechanisms of glioblastoma invasion. - Highlights: • We examine 5 glioblastoma lines on the invasion capacity and actin cytoskeleton. • Glioblastoma cell lines mutated in both p53 and PTEN were the most invasive. • Less invasive cells showed much less lamellipodia, but more actin stress fibers. • A mechanism for the differences in tumor cell invasion is proposed

Actin cytoskeleton organization, cell surface modification and invasion rate of 5 glioblastoma cell lines differing in PTEN and p53 status

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Djuzenova, Cholpon S., E-mail: djuzenova_t@ukw.de [Department of Radiation Oncology, University Hospital, Josef-Schneider-Strasse 11, D-97080 Würzburg (Germany); Fiedler, Vanessa [Department of Radiation Oncology, University Hospital, Josef-Schneider-Strasse 11, D-97080 Würzburg (Germany); Memmel, Simon [Lehrstuhl für Biotechnologie und Biophysik, Universität Würzburg, Biozentrum Am Hubland, 97070 Würzburg (Germany); Katzer, Astrid; Hartmann, Susanne [Department of Radiation Oncology, University Hospital, Josef-Schneider-Strasse 11, D-97080 Würzburg (Germany); Krohne, Georg [Elektronenmikroskopie, Biozentrum, Universität Würzburg, Am Hubland, 97070 Würzburg (Germany); Zimmermann, Heiko [Hauptabteilung Biophysik and Kryotechnologie, Fraunhofer-Institut für Biomedizinische Technik, Lehrstuhl für Molekulare und Zelluläre Biotechnologie/Nanotechnologie, Universität des Saarlandes, Ensheimer Strasse 48, 66386 St. Ingbert (Germany); Scholz, Claus-Jürgen [Interdisciplinary Center for Clinical Research, University Hospital, Versbacher Strasse 7, 97078 Würzburg (Germany); Polat, Bülent; Flentje, Michael [Department of Radiation Oncology, University Hospital, Josef-Schneider-Strasse 11, D-97080 Würzburg (Germany); and others

2015-01-15

Glioblastoma cells exhibit highly invasive behavior whose mechanisms are not yet fully understood. The present study explores the relationship between the invasion capacity of 5 glioblastoma cell lines differing in p53 and PTEN status, expression of mTOR and several other marker proteins involved in cell invasion, actin cytoskeleton organization and cell morphology. We found that two glioblastoma lines mutated in both p53 and PTEN genes (U373-MG and SNB19) exhibited the highest invasion rates through the Matrigel or collagen matrix. In DK-MG (p53wt/PTENwt) and GaMG (p53mut/PTENwt) cells, F-actin mainly occurred in the numerous stress fibers spanning the cytoplasm, whereas U87-MG (p53wt/PTENmut), U373-MG and SNB19 (both p53mut/PTENmut) cells preferentially expressed F-actin in filopodia and lamellipodia. Scanning electron microscopy confirmed the abundant filopodia and lamellipodia in the PTEN mutated cell lines. Interestingly, the gene profiling analysis revealed two clusters of cell lines, corresponding to the most (U373-MG and SNB19, i.e. p53 and PTEN mutated cells) and less invasive phenotypes. The results of this study might shed new light on the mechanisms of glioblastoma invasion. - Highlights: • We examine 5 glioblastoma lines on the invasion capacity and actin cytoskeleton. • Glioblastoma cell lines mutated in both p53 and PTEN were the most invasive. • Less invasive cells showed much less lamellipodia, but more actin stress fibers. • A mechanism for the differences in tumor cell invasion is proposed.

“...those left behind.” Biology and Oncology of Invasive Glioma Cells

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Michael E Berens

1999-08-01

Full Text Available Although significant technical advances in surgical and radiation treatment for brain tumors have emerged in recent years, their impact on clinical outcome for patients has been disappointing. A fundamental source of the management challenge presented by glioma patients is the insidious propensity of the malignant cells to invade into adjacent normal brain. Invasive tumor cells escape surgical removal and geographically dodge lethal radiation exposure. Recent improved understanding of the biochemistry and molecular determinants of glioma cell invasion provide valuable insight to the underlying biological features of the disease, as well as illuminating possible new therapeutic targets. Heightened commitment to migrate and invade is accompanied by a glioma cell's reduced proliferative activity. The microenvironmental manipulations coincident to invasion and migration may also impact the glioma cell's response to cytotoxic treatments. These collateral aspects of the glioma cell invasive phenotype should be further explored and exploited as novel antiglioma therapies.

Putative alternative polyadenylation (APA) events in the early interaction of Salmonella enterica Typhimurium and human host cells.

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Afonso-Grunz, Fabian

2015-12-01

The immune response of epithelial cells upon infection is mediated by changing activity levels of a variety of proteins along with changes in mRNA, and also ncRNA abundance. Alternative polyadenylation (APA) represents a mechanism that diversifies gene expression similar to alternative splicing. T-cell activation, neuronal activity, development and several human diseases including viral infections involve APA, but at present it remains unclear if this mechanism is also implicated in the response to bacterial infections. Our recently published study of interacting Salmonella enterica Typhimurium and human host cells includes genome-wide expression profiles of human epithelial cells prior and subsequent to infection with the invasive pathogen. The generated dataset (GEO accession number: GSE61730) covers several points of time post infection, and one of these interaction stages was additionally profiled with MACE-based dual 3'Seq, which allows for identification of polyadenylation (PA) sites. The present study features the polyadenylation landscape in early interacting cells based on this data, and provides a comparison of the identified PA sites with those of a corresponding 3P-Seq dataset of non-interacting cells. Differential PA site usage of FTL , PRDX1 and VAPA results in transcription of mRNA isoforms with distinct sets of miRNA and protein binding sites that influence processing, localization, stability, and translation of the respective mRNA. APA of these candidate genes consequently harbors the potential to modulate the host cell response to bacterial infection.

Putative alternative polyadenylation (APA events in the early interaction of Salmonella enterica Typhimurium and human host cells

Directory of Open Access Journals (Sweden)

Fabian Afonso-Grunz

2015-12-01

Full Text Available The immune response of epithelial cells upon infection is mediated by changing activity levels of a variety of proteins along with changes in mRNA, and also ncRNA abundance. Alternative polyadenylation (APA represents a mechanism that diversifies gene expression similar to alternative splicing. T-cell activation, neuronal activity, development and several human diseases including viral infections involve APA, but at present it remains unclear if this mechanism is also implicated in the response to bacterial infections. Our recently published study of interacting Salmonella enterica Typhimurium and human host cells includes genome-wide expression profiles of human epithelial cells prior and subsequent to infection with the invasive pathogen. The generated dataset (GEO accession number: GSE61730 covers several points of time post infection, and one of these interaction stages was additionally profiled with MACE-based dual 3'Seq, which allows for identification of polyadenylation (PA sites. The present study features the polyadenylation landscape in early interacting cells based on this data, and provides a comparison of the identified PA sites with those of a corresponding 3P-Seq dataset of non-interacting cells. Differential PA site usage of FTL, PRDX1 and VAPA results in transcription of mRNA isoforms with distinct sets of miRNA and protein binding sites that influence processing, localization, stability, and translation of the respective mRNA. APA of these candidate genes consequently harbors the potential to modulate the host cell response to bacterial infection.

Human bone marrow mesenchymal stem cells induce collagen production and tongue cancer invasion.

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Sirpa Salo

Full Text Available Tumor microenvironment (TME is an active player in carcinogenesis and changes in its composition modify cancer growth. Carcinoma-associated fibroblasts, bone marrow-derived multipotent mesenchymal stem cells (BMMSCs, and inflammatory cells can all affect the composition of TME leading to changes in proliferation, invasion and metastasis formation of carcinoma cells. In this study, we confirmed an interaction between BMMSCs and oral tongue squamous cell carcinoma (OTSCC cells by analyzing the invasion progression and gene expression pattern. In a 3-dimensional myoma organotypic invasion model the presence of BMMSCs inhibited the proliferation but increased the invasion of OTSCC cells. Furthermore, the signals originating from OTSCC cells up-regulated the expression of inflammatory chemokines by BMMSCs, whereas BMMSC products induced the expression of known invasion linked molecules by carcinoma cells. Particularly, after the cell-cell interactions, the chemokine CCL5 was abundantly secreted from BMMSCs and a function blocking antibody against CCL5 inhibited BMMSC enhanced cancer invasion area. However, CCL5 blocking antibody did not inhibit the depth of invasion. Additionally, after exposure to BMMSCs, the expression of type I collagen mRNA in OTSCC cells was markedly up-regulated. Interestingly, also high expression of type I collagen N-terminal propeptide (PINP in vivo correlated with the cancer-specific mortality of OTSCC patients, whereas there was no association between cancer tissue CCL5 levels and the clinical parameters. In conclusion, our results suggest that the interaction between BMMSC and carcinoma cells induce cytokine and matrix molecule expression, of which high level of type I collagen production correlates with the prognosis of OTSCC patients.

Baicalein inhibits the migration and invasive properties of human hepatoma cells

International Nuclear Information System (INIS)

Chiu, Yung-Wei; Lin, Tseng-Hsi; Huang, Wen-Shih; Teng, Chun-Yuh; Liou, Yi-Sheng; Kuo, Wu-Hsien; Lin, Wea-Lung; Huang, Hai-I; Tung, Jai-Nien; Huang, Chih-Yang; Liu, Jer-Yuh; Wang, Wen-Hung; Hwang, Jin-Ming

2011-01-01

Flavonoids have been demonstrated to exert health benefits in humans. We investigated whether the flavonoid baicalein would inhibit the adhesion, migration, invasion, and growth of human hepatoma cell lines, and we also investigated its mechanism of action. The separate effects of baicalein and baicalin on the viability of HA22T/VGH and SK-Hep1 cells were investigated for 24 h. To evaluate their invasive properties, cells were incubated on matrigel-coated transwell membranes in the presence or absence of baicalein. We examined the effect of baicalein on the adhesion of cells, on the activation of matrix metalloproteinases (MMPs), protein kinase C (PKC), and p38 mitogen-activated protein kinase (MAPK), and on tumor growth in vivo. We observed that baicalein suppresses hepatoma cell growth by 55%, baicalein-treated cells showed lower levels of migration than untreated cells, and cell invasion was significantly reduced to 28%. Incubation of hepatoma cells with baicalein also significantly inhibited cell adhesion to matrigel, collagen I, and gelatin-coated substrate. Baicalein also decreased the gelatinolytic activities of the matrix metalloproteinases MMP-2, MMP-9, and uPA, decreased p50 and p65 nuclear translocation, and decreased phosphorylated I-kappa-B (IKB)-β. In addition, baicalein reduced the phosphorylation levels of PKCα and p38 proteins, which regulate invasion in poorly differentiated hepatoma cells. Finally, when SK-Hep1 cells were grown as xenografts in nude mice, intraperitoneal (i.p.) injection of baicalein induced a significant dose-dependent decrease in tumor growth. These results demonstrate the anticancer properties of baicalein, which include the inhibition of adhesion, invasion, migration, and proliferation of human hepatoma cells in vivo. - Highlight: → Baicalein inhibits several essential steps in the onset of metastasis.

Destructive impact of t-lymphocytes, NK and mast cells on basal cell layers: implications for tumor invasion

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Yuan, Hongyan; Hsiao, Yi-Hsuan; Zhang, Yiyu; Wang, Jinlian; Yin, Chao; Shen, Rong; Su, Yiping

2013-01-01

Our previous studies have suggested that the primary impact of immune cell infiltration into the normal or pre-invasive tissue component is associated with the physical destruction of epithelial capsules, which may promote tumor progression and invasion. Our current study attempted to further verify our previous observations and determine the primary type(s) of infiltrating immune cells and the possible mechanism associated with physical destructions of the epithelial capsules. In total, the study was conducted with 250 primary breast and prostate tumors, the primary immune cell of cytotoxic T-lymphocytes (CTL), Natural killer cells (NK) and Mast cells were analyzed by immunohistochemistry, fluorescent labeling and apoptosis assay. qRT-PCR was used for gene expression analysis. Our current study assessed the physical disruption of these immune cells and potential impact on the epithelial capsule of human breast and prostate tumors. Our study yield several clinically-relevant findings that have not been studied before. (1) A vast majority of these infiltrating immune cells are distributed in the normal-appearing or pre-invasive tissue components rather than in invasive cancer tissues. (2) These cells often form rings or semilunar structures that either surround focally-disrupted basal cell layers or physically attach to the basal cells. (3) Basal cells physically associated with these immune cells generally displayed distinct signs of degeneration, including substantially elevated apoptosis, necrosis, and reduced tumor suppressor p63 expression. In contrast, luminal cells overlying focally disrupted basal cell layers had a substantially increased proliferation rate and elevated expression of stem cell markers compared to their adjacent morphologically similar counterparts that overlie a non-disrupted capsule. Our findings suggest that at the early stage of tumor invasion, CTL, NK and Mast cells are the main types of tumor infiltrating immune cells involved in focal

Host cell proteins in biotechnology-derived products: A risk assessment framework.

Science.gov (United States)

de Zafra, Christina L Zuch; Quarmby, Valerie; Francissen, Kathleen; Vanderlaan, Martin; Zhu-Shimoni, Judith

2015-11-01

To manufacture biotechnology products, mammalian or bacterial cells are engineered for the production of recombinant therapeutic human proteins including monoclonal antibodies. Host cells synthesize an entire repertoire of proteins which are essential for their own function and survival. Biotechnology manufacturing processes are designed to produce recombinant therapeutics with a very high degree of purity. While there is typically a low residual level of host cell protein in the final drug product, under some circumstances a host cell protein(s) may copurify with the therapeutic protein and, if it is not detected and removed, it may become an unintended component of the final product. The purpose of this article is to enumerate and discuss factors to be considered in an assessment of risk of residual host cell protein(s) detected and identified in the drug product. The consideration of these factors and their relative ranking will lead to an overall risk assessment that informs decision-making around how to control the levels of host cell proteins. © 2015 Wiley Periodicals, Inc.

Host tree resistance against the polyphagous

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W. D. Morewood; K. Hoover; P. R. Neiner; J.R. McNeil; J. C. Sellmer

2004-01-01

Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae: Lamiini) is an invasive wood-boring beetle with an unusually broad host range and a proven ability to increase its host range as it colonizes new areas and encounters new tree species. The beetle is native to eastern Asia and has become an invasive pest in North America and Europe,...

Epigenetic regulation of CpG promoter methylation in invasive prostate cancer cells

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Farrar William L

2010-10-01

Full Text Available Abstract Background Recently, much attention has been focused on gaining a better understanding of the different populations of cells within a tumor and their contribution to cancer progression. One of the most commonly used methods to isolate a more aggressive sub-population of cells utilizes cell sorting based on expression of certain cell adhesion molecules. A recently established method we developed is to isolate these more aggressive cells based on their properties of increased invasive ability. These more invasive cells have been previously characterized as tumor initiating cells (TICs that have a stem-like genomic signature and express a number of stem cell genes including Oct3/4 and Nanog and are more tumorigenic compared to their 'non-invasive' counterpart. They also have a profile reminiscent of cells undergoing a classic pattern of epithelial to mesenchymal transition or EMT. Using this model of invasion, we sought to investigate which genes are under epigenetic control in this rare population of cells. Epigenetic modifications, specifically DNA methylation, are key events regulating the process of normal human development. To determine the specific methylation pattern in these invasive prostate cells, and if any developmental genes were being differentially regulated, we analyzed differences in global CpG promoter methylation. Results Differentially methylated genes were determined and select genes were chosen for additional analyses. The non-receptor tyrosine kinase BMX and transcription factor SOX1 were found to play a significant role in invasion. Ingenuity pathway analysis revealed the methylated gene list frequently displayed genes from the IL-6/STAT3 pathway. Cells which have decreased levels of the targets BMX and SOX1 also display loss of STAT3 activity. Finally, using Oncomine, it was determined that more aggressive metastatic prostate cancers in humans also have higher levels of both Stat3 and Sox1. Conclusions Using this

Host cell capable of producing enzymes useful for degradation of lignocellulosic material

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Los, Alrik Pieter; Sagt, Cornelis Maria Jacobus; Schoonneveld-Bergmans, Margot Elisabeth Francoise; Damveld, Robbertus Antonius

2017-08-22

The invention relates to a host cell comprising at least four different heterologous polynucleotides chosen from the group of polynucleotides encoding cellulases, hemicellulases and pectinases, wherein the host cell is capable of producing the at least four different enzymes chosen from the group of cellulases, hemicellulases and pectinases, wherein the host cell is a filamentous fungus and is capable of secretion of the at least four different enzymes. This host cell can suitably be used for the production of an enzyme composition that can be used in a process for the saccharification of cellulosic material.

Host cell capable of producing enzymes useful for degradation of lignocellulosic material

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Los, Alrik Pieter; Sagt, Cornelis Maria Jacobus; Schooneveld-Bergmans, Margot Elisabeth Francoise; Damveld, Robbertus Antonius

2015-08-18

The invention relates to a host cell comprising at least four different heterologous polynucleotides chosen from the group of polynucleotides encoding cellulases, hemicellulases and pectinases, wherein the host cell is capable of producing the at least four different enzymes chosen from the group of cellulases, hemicellulases and pectinases, wherein the host cell is a filamentous fungus and is capable of secretion of the at least four different enzymes. This host cell can suitably be used for the production of an enzyme composition that can be used in a process for the saccharification of cellulosic material.

Use of an optical trap for study of host-pathogen interactions for dynamic live cell imaging.

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Tam, Jenny M; Castro, Carlos E; Heath, Robert J W; Mansour, Michael K; Cardenas, Michael L; Xavier, Ramnik J; Lang, Matthew J; Vyas, Jatin M

2011-07-28

Dynamic live cell imaging allows direct visualization of real-time interactions between cells of the immune system(1, 2); however, the lack of spatial and temporal control between the phagocytic cell and microbe has rendered focused observations into the initial interactions of host response to pathogens difficult. Historically, intercellular contact events such as phagocytosis(3) have been imaged by mixing two cell types, and then continuously scanning the field-of-view to find serendipitous intercellular contacts at the appropriate stage of interaction. The stochastic nature of these events renders this process tedious, and it is difficult to observe early or fleeting events in cell-cell contact by this approach. This method requires finding cell pairs that are on the verge of contact, and observing them until they consummate their contact, or do not. To address these limitations, we use optical trapping as a non-invasive, non-destructive, but fast and effective method to position cells in culture. Optical traps, or optical tweezers, are increasingly utilized in biological research to capture and physically manipulate cells and other micron-sized particles in three dimensions(4). Radiation pressure was first observed and applied to optical tweezer systems in 1970(5, 6), and was first used to control biological specimens in 1987(7). Since then, optical tweezers have matured into a technology to probe a variety of biological phenomena(8-13). We describe a method(14) that advances live cell imaging by integrating an optical trap with spinning disk confocal microscopy with temperature and humidity control to provide exquisite spatial and temporal control of pathogenic organisms in a physiological environment to facilitate interactions with host cells, as determined by the operator. Live, pathogenic organisms like Candida albicans and Aspergillus fumigatus, which can cause potentially lethal, invasive infections in immunocompromised individuals(15, 16) (e.g. AIDS

Delphinidin inhibits BDNF-induced migration and invasion in SKOV3 ovarian cancer cells.

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Lim, Won-Chul; Kim, Hyunhee; Kim, Young-Joo; Park, Seung-Ho; Song, Ji-Hye; Lee, Ki Heon; Lee, In Ho; Lee, Yoo-Kyung; So, Kyeong A; Choi, Kyung-Chul; Ko, Hyeonseok

2017-12-01

Brain-derived neurotrophic factor (BDNF), the TrkB ligand, is associated with aggressive malignant behavior, including migration and invasion, in tumor cells and a poor prognosis in patients with various types of cancer. Delphinidin is a diphenylpropane-based polyphenolic ring structure-harboring compound, which exhibits a wide range of pharmacological activities, anti-tumor, anti-oxidant, anti-inflammatory, anti-angiogenic and anti-mutagenic activity. However, the possible role of delphinidin in the cancer migration and invasion is unclear. We investigated the suppressive effect of delphinidin on the cancer migration and invasion. Thus, we found that BDNF enhanced cancer migration and invasion in SKOV3 ovarian cancer cell. To exam the inhibitory role of delphinidin in SKOV3 ovarian cancer migration and invasion, we investigated the use of delphinidin as inhibitors of BDNF-induced motility and invasiveness in SKOV3 ovarian cancer cells in vitro. Here, we found that delphinidin prominently inhibited the BDNF-induced increase in cell migration and invasion of SKOV3 ovarian cancer cells. Furthermore, delphinidin remarkably inhibited BDNF-stimulated expression of MMP-2 and MMP-9. Also, delphinidin antagonized the phosphorylation of Akt and nuclear translocation of NF-κB permitted by the BDNF in SKOV3 ovarian cancer cells. Taken together, our findings provide new evidence that delphinidin suppressed the BDNF-induced ovarian cancer migration and invasion through decreasing of Akt activation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Slug/SNAI2 regulates cell proliferation and invasiveness of metastatic prostate cancer cell lines.

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Emadi Baygi, Modjtaba; Soheili, Zahra-Soheila; Essmann, Frank; Deezagi, Abdolkhaleg; Engers, Rainer; Goering, Wolfgang; Schulz, Wolfgang A

2010-08-01

Many metastatic cancers recapitulate the epithelial-to-mesenchymal transition (EMT) resulting in enhanced cell motility and invasiveness. The EMT is regulated by several transcription factors, including the zinc finger protein SNAI2, also named Slug, which appears to exert additional functions during development and cancer progression. We have studied the function of SNAI2 in prostate cancer cells. Quantitative RT-PCR analysis showed strong SNAI2 expression particularly in the PC-3 and PC3-16 prostate carcinoma cell lines. Knockdown of SNAI2 by specific siRNA induced changes in EMT markers and inhibited invasion of both cell lines into a matrigel matrix. SNAI2 siRNA-treated cells did not tolerate detachment from the culture plates, likely at least in part due to downregulation of integrin alpha6beta4. SNAI2 knockdown disturbed the microtubular and actin cytoskeletons, especially severely in PC-3 cells, resulting in grossly enlarged, flattened, and sometimes multinuclear cells. Knockdown also decreased cell proliferation, with a prominent G0/G1 arrest in PC3-16. Together, our data imply that SNAI2 exerts strong effects on the cytoskeleton and adhesion of those prostate cancer cells that express it and is necessary for their proliferation and invasiveness.

Stimulation of Hepatoma Cell Invasiveness and Metastatic Potential by Proteins Secreted From Irradiated Nonparenchymal Cells

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Zhou Leyuan [Department of Radiation Oncology, Zhongshan Hospital, Fudan University, Shanghai (China); Wang Zhiming [Department of Medical Oncology, Zhongshan Hospital, Fudan University, Shanghai (China); Gao Yabo [Department of Radiation Oncology, Zhongshan Hospital, Fudan University, Shanghai (China); Wang Lingyan [Experimental Research Center, Zhongshan Hospital, Fudan University, Shanghai (China); Zeng Zhaochong, E-mail: zeng.zhaochong@zs-hospital.sh.cn [Department of Radiation Oncology, Zhongshan Hospital, Fudan University, Shanghai (China)

2012-11-01

Purpose: To determine whether factors secreted by irradiated liver nonparenchymal cells (NPCs) may influence invasiveness and/or metastatic potential of hepatocellular carcinoma (HCC) cells and to elucidate a possible mechanism for such effect. Methods and Materials: Primary rat NPCs were cultured and divided into irradiated (10-Gy X-ray) and nonirradiated groups. Forty-eight hours after irradiation, conditioned medium from irradiated (SR) or nonirradiated (SnonR) cultures were collected and added to sublethally irradiated cultures of the hepatoma McA-RH7777 cell line. Then, hepatoma cells were continuously passaged for eight generations (RH10Gy-SR and RH10Gy-SnonR). The invasiveness and metastatic potential of McA-RH7777, RH10Gy-SnonR, and RH10Gy-SR cells were evaluated using an in vitro gelatinous protein (Matrigel) invasion and an in vivo metastasis assay. In addition, SR and SnonR were tested using rat cytokine antibody arrays and enzyme-linked immunosorbent assay (ELISA). Results: In vitro gelatinous protein invasion assay indicated that the numbers of invading cells was significantly higher in RH10Gy-SR (40 {+-} 4.74) than in RH10Gy-SnonR (30.6 {+-} 3.85) cells, and lowest in McA-RH7777 (11.4 {+-} 3.56) cells. The same pattern was observed in vivo in a lung metastasis assay, as evaluated by number of metastatic lung nodules seen with RH10Gy-SR (28.83 {+-} 5.38), RH10Gy-SnonR (22.17 {+-} 4.26), and McA-RH7777 (8.3 {+-} 3.8) cells. Rat cytokine antibody arrays and ELISA demonstrated that metastasis-promoting cytokines (tumor necrosis factor-{alpha} and interleukin-6), circulating growth factors (vascular endothelial growth factor and epidermal growth factor), and metalloproteinases (MMP-2 and MMP-9) were upregulated in SR compared with SnonR. Conclusions: Radiation can increase invasiveness and metastatic potential of sublethally irradiated hepatoma cells, and soluble mediators released from irradiated NPCs promote this potential. Increased secretion of

Deeply invasive candidiasis.

NARCIS (Netherlands)

Ostrosky-Zeichner, L.; Rex, J.H.; Bennett, J.; Kullberg, B.J.

2002-01-01

The incidence of invasive candidiasis is on the rise because of increasing numbers of immunocompromised hosts and more invasive medical technology. Recovery of Candida spp from several body sites in a critically ill or immunocompromised patient should raise the question of disseminated disease.

Donor Satellite Cell Engraftment is Significantly Augmented When the Host Niche is Preserved and Endogenous Satellite Cells are Incapacitated

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Boldrin, Luisa; Neal, Alice; Zammit, Peter S; Muntoni, Francesco; Morgan, Jennifer E

2012-01-01

Stem cell transplantation is already in clinical practice for certain genetic diseases and is a promising therapy for dystrophic muscle. We used the mdx mouse model of Duchenne muscular dystrophy to investigate the effect of the host satellite cell niche on the contribution of donor muscle stem cells (satellite cells) to muscle regeneration. We found that incapacitation of the host satellite cells and preservation of the muscle niche promote donor satellite cell contribution to muscle regeneration and functional reconstitution of the satellite cell compartment. But, if the host niche is not promptly refilled, or is filled by competent host satellite cells, it becomes nonfunctional and donor engraftment is negligible. Application of this regimen to aged host muscles also promotes efficient regeneration from aged donor satellite cells. In contrast, if the niche is destroyed, yet host satellite cells remain proliferation-competent, donor-derived engraftment is trivial. Thus preservation of the satellite cell niche, concomitant with functional impairment of the majority of satellite cells within dystrophic human muscles, may improve the efficiency of stem cell therapy. Stem Cells2012;30:1971–1984 PMID:22730231

Exosomes Promote Ovarian Cancer Cell Invasion through Transfer of CD44 to Peritoneal Mesothelial Cells.

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Nakamura, Koji; Sawada, Kenjiro; Kinose, Yasuto; Yoshimura, Akihiko; Toda, Aska; Nakatsuka, Erika; Hashimoto, Kae; Mabuchi, Seiji; Morishige, Ken-Ichirou; Kurachi, Hirohisa; Lengyel, Ernst; Kimura, Tadashi

2017-01-01

Epithelial ovarian cancer (EOC) cells metastasize within the peritoneal cavity and directly encounter human peritoneal mesothelial cells (HPMC) as the initial step of metastasis. The contact between ovarian cancer cells and the single layer of mesothelial cells involves direct communications that modulate cancer progression but the mechanisms are unclear. One candidate mediating cell-cell communications is exosomes, 30-100 nm membrane vesicles of endocytic origin, through the cell-cell transfer of proteins, mRNAs, or microRNAs. Therefore, the goal was to mechanistically characterize how EOC-derived exosomes modulate metastasis. Exosomes from ovarian cancer cells were fluorescently labeled and cocultured with HPMCs which internalized the exosomes. Upon exosome uptake, HPMCs underwent a change in cellular morphology to a mesenchymal, spindle phenotype. CD44, a cell surface glycoprotein, was found to be enriched in the cancer cell-derived exosomes, transferred, and internalized to HPMCs, leading to high levels of CD44 in HPMCs. This increased CD44 expression in HPMCs promoted cancer invasion by inducing the HPMCs to secrete MMP9 and by cleaning the mesothelial barrier for improved cancer cell invasion. When CD44 expression was knocked down in cancer cells, exosomes had fewer effects on HPMCs. The inhibition of exosome release from cancer cells blocked CD44 internalization in HPMCs and suppressed ovarian cancer invasion. In ovarian cancer omental metastasis, positive CD44 expression was observed in those mesothelial cells that directly interacted with cancer cells, whereas CD44 expression was negative in the mesothelial cells remote from the invading edge. This study indicates that ovarian cancer-derived exosomes transfer CD44 to HPMCs, facilitating cancer invasion. Mechanistic insight from the current study suggests that therapeutic targeting of exosomes may be beneficial in treating ovarian cancer. Mol Cancer Res; 15(1); 78-92. ©2016 AACR. ©2016 American

Human mammary fibroblasts stimulate invasion of breast cancer cells in a three-dimensional culture and increase stroma development in mouse xenografts

International Nuclear Information System (INIS)

Olsen, Charlotta J; Moreira, José; Lukanidin, Eugene M; Ambartsumian, Noona S

2010-01-01

Tumour phenotype is regulated in a complex fashion as a result of interactions between malignant cells and the tumour stroma. Fibroblasts are the most abundant and perhaps most active part of the tumour stroma. A better understanding of the changes that occur in fibroblasts in response to the presence of malignant cells may lead to the development of new strategies for cancer treatment. We explored the effects of fibroblasts on the growth and invasion of mammary carcinoma tumour cells in vitro and in vivo. In order to analyse secreted factors that affect invasive abilities of breast cancer cells we co-cultured human mammary fibroblasts (HMF3s) and cancer cells (MCF7S1) in three-dimensional (3D) growth conditions devoid of heterogeneous cell-cell contact. To study the possible influence of fibroblasts on MCF7S1 cancer cell growth in vivo we co-injected HMF3s and MCF7S1 cells in Balb/c nu/nu mice. In 3D co-culture both HMF3s and MCF7S1 cells demonstrated enhanced invasion into a Matrigel matrix. This was correlated with enhanced expression of the metastasis promoting S100A4 protein in fibroblasts, stimulation of the matrix metalloproteinase (MMP)-2 activity, and enhanced secretion of a range of different cytokines. Orthotopic injection of oestrogen-dependent MCF7S1 cancer cells together with fibroblasts showed stimulation of tumour growth in mice without an external oestrogen supply. The resulting tumours were characterized by increased development of extracellular matrix, as well as an increase of murine S100A4 concentration and activity of MMP-2 in the tumour interstitial fluid. Stimulation of the invasive phenotype of tumour cells in 3D co-cultures with fibroblasts could be correlated with increased production of S100A4 and MMP-2. We propose that enhanced development of mouse host-derived tumour stroma in a MCF7S1 co-injection xenograft model leads to oestrogen independency and is triggered by the initial presence of human fibroblasts

HUWE1 Ubiquitylates and Degrades the RAC Activator TIAM1 Promoting Cell-Cell Adhesion Disassembly, Migration, and Invasion

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Lynsey Vaughan

2015-01-01

Full Text Available The E3 ubiquitin ligase HUWE1, deregulated in carcinoma, has been implicated in tumor formation. Here, we uncover a role for HUWE1 in cell migration and invasion through degrading the RAC activator TIAM1, implying an additional function in malignant progression. In MDCKII cells in response to HGF, HUWE1 catalyzes TIAM1 ubiquitylation and degradation predominantly at cell-cell adhesions, facilitating junction disassembly, migration, and invasion. Depleting HUWE1 or mutating the TIAM1 ubiquitylation site prevents TIAM1 degradation, antagonizing scattering, and invasion. Moreover, simultaneous depletion of TIAM1 restores migration and invasion in HUWE1-depleted cells. Significantly, we show that HUWE1 stimulates human lung cancer cell invasion through regulating TIAM1 stability. Finally, we demonstrate that HUWE1 and TIAM1 protein levels are inversely correlated in human lung carcinomas. Thus, we elucidate a critical role for HUWE1 in regulating epithelial cell-cell adhesion and provide additional evidence that ubiquitylation contributes to spatiotemporal control of RAC.

Clonorchis sinensis infestation promotes three-dimensional aggregation and invasion of cholangiocarcinoma cells.

Directory of Open Access Journals (Sweden)

Jihee Won

Full Text Available Numerous experimental and epidemiological studies have demonstrated a correlation between Clonorchis sinensis (C. sinensis infestation and cholangiocarcinoma (CCA. However, the role of C. sinensis in the increased invasiveness and proliferation involved in the malignancy of CCA has not been addressed yet. Here, we investigated the possibility that C. sinensis infestation promotes expression of focal and cell-cell adhesion proteins in CCA cells and secretion of matrix metalloproteinases (MMPs. Adhesion proteins help maintain cell aggregates, and MMPs promote the three-dimensional invasion of cells into the neighboring extracellular matrix (ECM. Using a novel microfluidic assay, we quantitatively addressed the role of excretory-secretory products (ESPs gradients from C. sinensis in promoting the invasion of cells into the neighboring ECM.

Host cells and methods for producing diacid compounds

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Steen, Eric J.; Fortman, Jeffrey L.; Dietrich, Jeffrey A.; Keasling, Jay D.

2018-04-24

The present invention provides for a method of producing one or more fatty acid derived dicarboxylic acids in a genetically modified host cell which does not naturally produce the one or more derived fatty acid derived dicarboxylic acids. The invention provides for the biosynthesis of dicarboxylic acid ranging in length from C3 to C26. The host cell can be further modified to increase fatty acid production or export of the desired fatty acid derived compound, and/or decrease fatty acid storage or metabolism.

Stable SET knockdown in breast cell carcinoma inhibits cell migration and invasion

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Li, Jie [Department of Occupational Health and Occupational Medicine, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou (China); Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen (China); Yang, Xi-fei [Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen (China); Ren, Xiao-hu [Department of Occupational Health and Occupational Medicine, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou (China); Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen (China); Meng, Xiao-jing [Department of Occupational Health and Occupational Medicine, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou (China); Huang, Hai-yan [Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen (China); Zhao, Qiong-hui [Shenzhen Entry-Exit Inspection and Quarantine Bureau, Shenzhen (China); Yuan, Jian-hui; Hong, Wen-xu; Xia, Bo; Huang, Xin-feng; Zhou, Li [Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen (China); Liu, Jian-jun, E-mail: bio-research@hotmail.com [Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen (China); Zou, Fei, E-mail: zoufei616@163.com [Department of Occupational Health and Occupational Medicine, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou (China)

2014-10-10

Highlights: • We employed RNA interference to knockdown SET expression in breast cancer cells. • Knockdown of SET expression inhibits cell proliferation, migration and invasion. • Knockdown of SET expression increases the activity and expression of PP2A. • Knockdown of SET expression decreases the expression of MMP-9. - Abstract: Breast cancer is the most malignant tumor for women, however, the mechanisms underlying this devastating disease remain unclear. SET is an endogenous inhibitor of protein phosphatase 2A (PP2A) and involved in many physiological and pathological processes. SET could promote the occurrence of tumor through inhibiting PP2A. In this study, we explore the role of SET in the migration and invasion of breast cancer cells MDA-MB-231 and ZR-75-30. The stable suppression of SET expression through lentivirus-mediated RNA interference (RNAi) was shown to inhibit the growth, migration and invasion of breast cancer cells. Knockdown of SET increases the activity and expression of PP2Ac and decrease the expression of matrix metalloproteinase 9 (MMP-9). These data demonstrate that SET may be involved in the pathogenic processes of breast cancer, indicating that SET can serve as a potential therapeutic target for the treatment of breast cancer.

Stable SET knockdown in breast cell carcinoma inhibits cell migration and invasion

International Nuclear Information System (INIS)

Li, Jie; Yang, Xi-fei; Ren, Xiao-hu; Meng, Xiao-jing; Huang, Hai-yan; Zhao, Qiong-hui; Yuan, Jian-hui; Hong, Wen-xu; Xia, Bo; Huang, Xin-feng; Zhou, Li; Liu, Jian-jun; Zou, Fei

2014-01-01

Highlights: • We employed RNA interference to knockdown SET expression in breast cancer cells. • Knockdown of SET expression inhibits cell proliferation, migration and invasion. • Knockdown of SET expression increases the activity and expression of PP2A. • Knockdown of SET expression decreases the expression of MMP-9. - Abstract: Breast cancer is the most malignant tumor for women, however, the mechanisms underlying this devastating disease remain unclear. SET is an endogenous inhibitor of protein phosphatase 2A (PP2A) and involved in many physiological and pathological processes. SET could promote the occurrence of tumor through inhibiting PP2A. In this study, we explore the role of SET in the migration and invasion of breast cancer cells MDA-MB-231 and ZR-75-30. The stable suppression of SET expression through lentivirus-mediated RNA interference (RNAi) was shown to inhibit the growth, migration and invasion of breast cancer cells. Knockdown of SET increases the activity and expression of PP2Ac and decrease the expression of matrix metalloproteinase 9 (MMP-9). These data demonstrate that SET may be involved in the pathogenic processes of breast cancer, indicating that SET can serve as a potential therapeutic target for the treatment of breast cancer

Shigella subverts the host recycling compartment to rupture its vacuole.

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Mellouk, Nora; Weiner, Allon; Aulner, Nathalie; Schmitt, Christine; Elbaum, Michael; Shorte, Spencer L; Danckaert, Anne; Enninga, Jost

2014-10-08

Shigella enters epithlial cells via internalization into a vacuole. Subsequent vacuolar membrane rupture allows bacterial escape into the cytosol for replication and cell-to-cell spread. Bacterial effectors such as IpgD, a PI(4,5)P2 phosphatase that generates PI(5)P and alters host actin, facilitate this internalization. Here, we identify host proteins involved in Shigella uptake and vacuolar membrane rupture by high-content siRNA screening and subsequently focus on Rab11, a constituent of the recycling compartment. Rab11-positive vesicles are recruited to the invasion site before vacuolar rupture, and Rab11 knockdown dramatically decreases vacuolar membrane rupture. Additionally, Rab11 recruitment is absent and vacuolar rupture is delayed in the ipgD mutant that does not dephosphorylate PI(4,5)P₂ into PI(5)P. Ultrastructural analyses of Rab11-positive vesicles further reveal that ipgD mutant-containing vacuoles become confined in actin structures that likely contribute to delayed vacular rupture. These findings provide insight into the underlying molecular mechanism of vacuole progression and rupture during Shigella invasion. Copyright © 2014 Elsevier Inc. All rights reserved.

Dose- and time-dependence of the host-mediated response to paclitaxel therapy: a mathematical modeling approach.

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Benguigui, Madeleine; Alishekevitz, Dror; Timaner, Michael; Shechter, Dvir; Raviv, Ziv; Benzekry, Sebastien; Shaked, Yuval

2018-01-05

It has recently been suggested that pro-tumorigenic host-mediated processes induced in response to chemotherapy counteract the anti-tumor activity of therapy, and thereby decrease net therapeutic outcome. Here we use experimental data to formulate a mathematical model describing the host response to different doses of paclitaxel (PTX) chemotherapy as well as the duration of the response. Three previously described host-mediated effects are used as readouts for the host response to therapy. These include the levels of circulating endothelial progenitor cells in peripheral blood and the effect of plasma derived from PTX-treated mice on migratory and invasive properties of tumor cells in vitro . A first set of mathematical models, based on basic principles of pharmacokinetics/pharmacodynamics, did not appropriately describe the dose-dependence and duration of the host response regarding the effects on invasion. We therefore provide an alternative mathematical model with a dose-dependent threshold, instead of a concentration-dependent one, that describes better the data. This model is integrated into a global model defining all three host-mediated effects. It not only precisely describes the data, but also correctly predicts host-mediated effects at different doses as well as the duration of the host response. This mathematical model may serve as a tool to predict the host response to chemotherapy in cancer patients, and therefore may be used to design chemotherapy regimens with improved therapeutic outcome by minimizing host mediated effects.

Perturbation of host-cell membrane is a primary mechanism of HIV cytopathology.

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Cloyd, M W; Lynn, W S

1991-04-01

Cytopathic viruses injure cells by a number of different mechanisms. The mechanism by which HIV-1 injures T cells was studied by temporally examining host-cell macromolecular syntheses, stages of the cell cycle, and membrane permeability following acute infection. T cells cytopathically infected at an m.o.i. of 1-5 grew normally for 24-72 hr, depending on the cell line, followed by the first manifestation of cell injury, slowing of cell division. At that time significant amounts of unintegrated HIV DNA and p24 core protein became detectable, and acridine orange flow cytometric cell cycle studies demonstrated the presence of fewer cells in the G2/M stage of the cell cycle. There was no change in the frequency of cells in the S-stage, and metabolic pulsing with radioactive precursors demonstrated that host-cell DNA, RNA, and protein syntheses were normal at that time and normal up to the time cells started to die (approximately 24 hr later), when all three decreased. Cellular lipid synthesis, however, was perturbed when cell multiplication slowed, with phospholipid synthesis reduced and neutral lipid synthesis enhanced. Permeability of the host-cell membrane to small molecules, such as Ca2+ and sucrose, was slightly enhanced early postinfection, and by the time of slowing of cell division, host membrane permeability was greatly increased to both Ca2+ and sucrose (Stokes radius 5.2 A) but not to inulin (Stokes radium 20 A). These changes in host-cell membrane permeability and phospholipid synthesis were not observed in acutely infected H9 cells, which are not susceptible to HIV cytopathology. Thus, HIV-1 appeared to predominantly injure T cells by perturbing host-cell membrane permeability and lipid synthesis, which is similar to the cytopathic mechanisms of paramyxoviruses.

An invasive mammal (the gray squirrel, Sciurus carolinensis) commonly hosts diverse and atypical genotypes of the zoonotic pathogen Borrelia burgdorferi sensu lato

DEFF Research Database (Denmark)

Millins, Caroline; Magierecka, Agnieszka; Gilbert, Lucy

2015-01-01

and may support host specific strains. This study examined the role of grey squirrels (Sciurus carolinensis), (n=679), an invasive species in the United Kingdom (UK), as B. burgdorferi s.l. hosts. We found that grey squirrels were frequently infested with Ixodes ricinus, the main vector of B. burgdorferi...

Collective cell migration: Implications for wound healing and cancer invasion

Directory of Open Access Journals (Sweden)

Li Li

2013-07-01

Full Text Available During embryonic morphogenesis, wound repair and cancer invasion, cells often migrate collectively via tight cell-cell junctions, a process named collective migration. During such migration, cells move as coherent groups, large cell sheets, strands or tubes rather than individually. One unexpected finding regarding collective cell migration is that being a "multicellular structure" enables cells to better respond to chemical and physical cues, when compared with isolated cells. This is important because epithelial cells heal wounds via the migration of large sheets of cells with tight intercellular connections. Recent studies have gained some mechanistic insights that will benefit the clinical understanding of wound healing in general. In this review, we will briefly introduce the role of collective cell migration in wound healing, regeneration and cancer invasion and discuss its underlying mechanisms as well as implications for wound healing.

Protease-activated receptor 2 modulates proliferation and invasion of oral squamous cell carcinoma cells.

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Al-Eryani, Kamal; Cheng, Jun; Abé, Tatsuya; Maruyama, Satoshi; Yamazaki, Manabu; Babkair, Hamzah; Essa, Ahmed; Saku, Takashi

2015-07-01

Based on our previous finding that protease-activated receptor 2 (PAR-2) regulates hemophagocytosis of oral squamous cell carcinoma (SCC) cells, which induces their heme oxygenase 1-dependent keratinization, we have formulated a hypothesis that PAR-2 functions in wider activities of SCC cells. To confirm this hypothesis, we investigated immunohistochemical profiles of PAR-2 in oral SCC tissues and its functional roles in cell proliferation and invasion in SCC cells in culture. The PAR-2 expression modes were determined in 48 surgical tissue specimens of oral SCC. Using oral SCC-derived cell systems, we determined both gene and protein expression levels of PAR-2. SCC cell proliferation and invasive properties were also examined in conditions in which PAR-2 was activated by the synthetic peptide SLIGRL. PAR-2 was immunolocalized in oral SCC and carcinoma in situ cells, especially in those on the periphery of carcinoma cell foci (100% of cases), but not in normal oral epithelia. Its expression at both gene and protein levels was confirmed in 3 oral SCC cell lines including ZK-1. Activation of PAR-2 induced ZK-1 cell proliferation in a dose-dependent manner. PAR-2-activated ZK-1 cells invaded faster than nonactivated ones. The expression of PAR-2 is specific to oral malignancies, and PAR-2 regulates the growth and invasion of oral SCC cells. Copyright © 2015 Elsevier Inc. All rights reserved.

Lipid exchange between Borrelia burgdorferi and host cells.

Directory of Open Access Journals (Sweden)

Jameson T Crowley

2013-01-01

Full Text Available Borrelia burgdorferi, the agent of Lyme disease, has cholesterol and cholesterol-glycolipids that are essential for bacterial fitness, are antigenic, and could be important in mediating interactions with cells of the eukaryotic host. We show that the spirochetes can acquire cholesterol from plasma membranes of epithelial cells. In addition, through fluorescent and confocal microscopy combined with biochemical approaches, we demonstrated that B. burgdorferi labeled with the fluorescent cholesterol analog BODIPY-cholesterol or (3H-labeled cholesterol transfer both cholesterol and cholesterol-glycolipids to HeLa cells. The transfer occurs through two different mechanisms, by direct contact between the bacteria and eukaryotic cell and/or through release of outer membrane vesicles. Thus, two-way lipid exchange between spirochetes and host cells can occur. This lipid exchange could be an important process that contributes to the pathogenesis of Lyme disease.

Pharmacological targeting of membrane rigidity: implications on cancer cell migration and invasion

International Nuclear Information System (INIS)

Braig, Simone; Stoiber, Katharina; Zahler, Stefan; Vollmar, Angelika M

2015-01-01

The invasive potential of cancer cells strongly depends on cellular stiffness, a physical quantity that is not only regulated by the mechanical impact of the cytoskeleton but also influenced by the membrane rigidity. To analyze the specific role of membrane rigidity in cancer progression, we treated cancer cells with the Acetyl-CoA carboxylase inhibitor Soraphen A and revealed an alteration of the phospholipidome via mass spectrometry. Migration, invasion, and cell death assays were employed to relate this alteration to functional consequences, and a decrease of migration and invasion without significant impact on cell death has been recorded. Fourier fluctuation analysis of giant plasma membrane vesicles showed that Soraphen A increases membrane rigidity of carcinoma cell membranes. Mechanical measurements of the creep deformation response of whole intact cells were performed using the optical stretcher. The increase in membrane rigidity was observed in one cell line without changing the creep deformation response indicating no restructuring of the cytoskeleton. These data indicate that the increase of membrane rigidity alone is sufficient to inhibit invasiveness of cancer cells, thus disclosing the eminent role of membrane rigidity in migratory processes. (paper)

Cell invasion in the spheroid sprouting assay: a spatial organisation analysis adaptable to cell behaviour.

Directory of Open Access Journals (Sweden)

Silvia Blacher

Full Text Available The endothelial cell spheroid assay provides a suitable in vitro model to study (lymph angiogenesis and test pro- and anti-(lymph angiogenic factors or drugs. Usually, the extent of cell invasion, observed through optical microscopy, is measured. The present study proposes the spatial distribution of migrated cells as a new descriptor of the (lymph angiogenic response. The utility of this novel method rests with its capacity to locally characterise spheroid structure, allowing not only the investigation of single and collective cell invasion but also the evolution of the spheroid core itself. Moreover, the proposed method can be applied to 2D-projected spheroid images obtained by optical microscopy, as well as to 3D images acquired by confocal microscopy. To validate the proposed methodology, endothelial cell invasion was evaluated under different experimental conditions. The results were compared with widely used global parameters. The comparison shows that our method prevents local spheroid modifications from being overlooked and leading to the possible misinterpretation of results.

Vascular Endothelial Growth Factor Receptor 1 Contributes to Escherichia coli K1 Invasion of Human Brain Microvascular Endothelial Cells through the Phosphatidylinositol 3-Kinase/Akt Signaling Pathway▿ †

OpenAIRE

Zhao, Wei-Dong; Liu, Wei; Fang, Wen-Gang; Kim, Kwang Sik; Chen, Yu-Hua

2010-01-01

Escherichia coli is the most common Gram-negative organism causing neonatal meningitis. Previous studies demonstrated that E. coli K1 invasion of brain microvascular endothelial cells (BMEC) is required for penetration into the central nervous system, but the microbe-host interactions that are involved in this process remain incompletely understood. Here we report the involvement of vascular endothelial growth factor receptor 1 (VEGFR1) expressed on human brain microvascular endothelial cells...

Extra-pancreatic invasion induces lipolytic and fibrotic changes in the adipose microenvironment, with released fatty acids enhancing the invasiveness of pancreatic cancer cells

Science.gov (United States)

Okumura, Takashi; Ohuchida, Kenoki; Sada, Masafumi; Abe, Toshiya; Endo, Sho; Koikawa, Kazuhiro; Iwamoto, Chika; Miura, Daisuke; Mizuuchi, Yusuke; Moriyama, Taiki; Nakata, Kohei; Miyasaka, Yoshihiro; Manabe, Tatsuya; Ohtsuka, Takao; Nagai, Eishi; Mizumoto, Kazuhiro; Oda, Yoshinao; Hashizume, Makoto; Nakamura, Masafumi

2017-01-01

Pancreatic cancer progression involves components of the tumor microenvironment, including stellate cells, immune cells, endothelial cells, and the extracellular matrix. Although peripancreatic fat is the main stromal component involved in extra-pancreatic invasion, its roles in local invasion and metastasis of pancreatic cancer remain unclear. This study investigated the role of adipose tissue in pancreatic cancer progression using genetically engineered mice (Pdx1-Cre; LSL-KrasG12D; Trp53R172H/+) and an in vitro model of organotypic fat invasion. Mice fed a high fat diet had significantly larger primary pancreatic tumors and a significantly higher rate of distant organ metastasis than mice fed a standard diet. In the organotypic fat invasion model, pancreatic cancer cell clusters were smaller and more elongated in shape and showed increased fibrosis. Adipose tissue-derived conditioned medium enhanced pancreatic cancer cell invasiveness and gemcitabine resistance, as well as inducing morphologic changes in cancer cells and increasing the numbers of lipid droplets in their cytoplasm. The concentrations of oleic, palmitoleic, and linoleic acids were higher in adipose tissue-derived conditioned medium than in normal medium, with these fatty acids significantly enhancing the migration of cancer cells. Mature adipocytes were smaller and the concentration of fatty acids in the medium higher when these cells were co-cultured with cancer cells. These findings indicate that lipolytic and fibrotic changes in peripancreatic adipose tissue enhance local invasiveness and metastasis via adipocyte-released fatty acids. Inhibition of fatty acid uptake by cancer cells may be a novel therapy targeting interactions between cancer and stromal cells. PMID:28407685

Linking climate suitability, spread rates and host-impact when estimating the potential costs of invasive pests.

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Kriticos, Darren J; Leriche, Agathe; Palmer, David J; Cook, David C; Brockerhoff, Eckehard G; Stephens, Andréa E A; Watt, Michael S

2013-01-01

Biosecurity agencies need robust bioeconomic tools to help inform policy and allocate scarce management resources. They need to estimate the potential for each invasive alien species (IAS) to create negative impacts, so that relative and absolute comparisons can be made. Using pine processionary moth (Thaumetopoea pityocampa sensu lato) as an example, these needs were met by combining species niche modelling, dispersal modelling, host impact and economic modelling. Within its native range (the Mediterranean Basin and adjacent areas), T. pityocampa causes significant defoliation of pines and serious urticating injuries to humans. Such severe impacts overseas have fuelled concerns about its potential impacts, should it be introduced to New Zealand. A stochastic bioeconomic model was used to estimate the impact of PPM invasion in terms of pine production value lost due to a hypothetical invasion of New Zealand by T. pityocampa. The bioeconomic model combines a semi-mechanistic niche model to develop a climate-related damage function, a climate-related forest growth model, and a stochastic spread model to estimate the present value (PV) of an invasion. Simulated invasions indicate that Thaumetopoea pityocampa could reduce New Zealand's merchantable and total pine stem volume production by 30%, reducing forest production by between NZ$1,550 M to NZ$2,560 M if left untreated. Where T. pityocampa is controlled using aerial application of an insecticide, projected losses in PV were reduced, but still significant (NZ$30 M to NZ$2,210 M). The PV estimates were more sensitive to the efficacy of the spray program than the potential rate of spread of the moth. Our novel bioeconomic method provides a refined means of estimating potential impacts of invasive alien species, taking into account climatic effects on asset values, the potential for pest impacts, and pest spread rates.

Linking climate suitability, spread rates and host-impact when estimating the potential costs of invasive pests.

Directory of Open Access Journals (Sweden)

Darren J Kriticos

Full Text Available Biosecurity agencies need robust bioeconomic tools to help inform policy and allocate scarce management resources. They need to estimate the potential for each invasive alien species (IAS to create negative impacts, so that relative and absolute comparisons can be made. Using pine processionary moth (Thaumetopoea pityocampa sensu lato as an example, these needs were met by combining species niche modelling, dispersal modelling, host impact and economic modelling. Within its native range (the Mediterranean Basin and adjacent areas, T. pityocampa causes significant defoliation of pines and serious urticating injuries to humans. Such severe impacts overseas have fuelled concerns about its potential impacts, should it be introduced to New Zealand. A stochastic bioeconomic model was used to estimate the impact of PPM invasion in terms of pine production value lost due to a hypothetical invasion of New Zealand by T. pityocampa. The bioeconomic model combines a semi-mechanistic niche model to develop a climate-related damage function, a climate-related forest growth model, and a stochastic spread model to estimate the present value (PV of an invasion. Simulated invasions indicate that Thaumetopoea pityocampa could reduce New Zealand's merchantable and total pine stem volume production by 30%, reducing forest production by between NZ$1,550 M to NZ$2,560 M if left untreated. Where T. pityocampa is controlled using aerial application of an insecticide, projected losses in PV were reduced, but still significant (NZ$30 M to NZ$2,210 M. The PV estimates were more sensitive to the efficacy of the spray program than the potential rate of spread of the moth. Our novel bioeconomic method provides a refined means of estimating potential impacts of invasive alien species, taking into account climatic effects on asset values, the potential for pest impacts, and pest spread rates.

Downregulation of CCR1 inhibits human hepatocellular carcinoma cell invasion

International Nuclear Information System (INIS)

Wu Xiaofeng; Fan Jia; Wang Xiaoying; Zhou Jian; Qiu Shuangjian; Yu Yao; Liu Yinkun; Tang Zhaoyou

2007-01-01

CC chemokine receptor 1 (CCR1) has an important role in the recruitment of leukocytes to the site of inflammation. The migration and metastasis of tumor cells shares many similarities with leukocyte trafficking, which is mainly regulated by chemokine receptor-ligand interactions. CCR1 is highly expressed in hepatocellular carcinoma (HCC) cells and tissues with unknown functions. In this study, we silenced CCR1 expression in the human HCC cell line HCCLM3 using artificial microRNA (miRNA)-mediated RNA interference (RNAi) and examined the invasiveness and proliferation of CCR1-silenced HCCLM3 cells and the matrix metalloproteinase (MMP) activity. The miRNA-mediated knockdown expression of CCR1 significantly inhibited the invasive ability of HCCLM3 cells, but had only a minor effect on the cellular proliferation rate. Moreover, CCR1 knockdown significantly reduced the secretion of MMP-2. Together, these findings indicate that CCR1 has an important role in HCCLM3 invasion and that CCR1 might be a new target of HCC treatment

Prebiotic Oligosaccharides Potentiate Host Protective Responses against L. Monocytogenes Infection

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Poyin Chen

2017-12-01

Full Text Available Prebiotic oligosaccharides are used to modulate enteric pathogens and reduce pathogen shedding. The interactions with prebiotics that alter Listeria monocytogenes infection are not yet clearly delineated. L. monocytogenes cellular invasion requires a concerted manipulation of host epithelial cell membrane receptors to initiate internalization and infection often via receptor glycosylation. Bacterial interactions with host glycans are intimately involved in modulating cellular responses through signaling cascades at the membrane and in intracellular compartments. Characterizing the mechanisms underpinning these modulations is essential for predictive use of dietary prebiotics to diminish pathogen association. We demonstrated that human milk oligosaccharide (HMO pretreatment of colonic epithelial cells (Caco-2 led to a 50% decrease in Listeria association, while Biomos pretreatment increased host association by 150%. L. monocytogenes-induced gene expression changes due to oligosaccharide pretreatment revealed global alterations in host signaling pathways that resulted in differential subcellular localization of L. monocytogenes during early infection. Ultimately, HMO pretreatment led to bacterial clearance in Caco-2 cells via induction of the unfolded protein response and eIF2 signaling, while Biomos pretreatment resulted in the induction of host autophagy and L. monocytogenes vacuolar escape earlier in the infection progression. This study demonstrates the capacity of prebiotic oligosaccharides to minimize infection through induction of host-intrinsic protective responses.

Nuclear Phosphatidylinositol-Phosphate Type I Kinase α-Coupled Star-PAP Polyadenylation Regulates Cell Invasion.

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A P, Sudheesh; Laishram, Rakesh S

2018-03-01

Star-PAP, a nuclear phosphatidylinositol (PI) signal-regulated poly(A) polymerase (PAP), couples with type I PI phosphate kinase α (PIPKIα) and controls gene expression. We show that Star-PAP and PIPKIα together regulate 3'-end processing and expression of pre-mRNAs encoding key anti-invasive factors ( KISS1R , CDH1 , NME1 , CDH13 , FEZ1 , and WIF1 ) in breast cancer. Consistently, the endogenous Star-PAP level is negatively correlated with the cellular invasiveness of breast cancer cells. While silencing Star-PAP or PIPKIα increases cellular invasiveness in low-invasiveness MCF7 cells, Star-PAP overexpression decreases invasiveness in highly invasive MDA-MB-231 cells in a cellular Star-PAP level-dependent manner. However, expression of the PIPKIα-noninteracting Star-PAP mutant or the phosphodeficient Star-PAP (S6A mutant) has no effect on cellular invasiveness. These results strongly indicate that PIPKIα interaction and Star-PAP S6 phosphorylation are required for Star-PAP-mediated regulation of cancer cell invasion and give specificity to target anti-invasive gene expression. Our study establishes Star-PAP-PIPKIα-mediated 3'-end processing as a key anti-invasive mechanism in breast cancer. Copyright © 2018 A.P. and Laishram.

Muscarinic receptor agonists stimulate matrix metalloproteinase 1-dependent invasion of human colon cancer cells

International Nuclear Information System (INIS)

Raufman, Jean-Pierre; Cheng, Kunrong; Saxena, Neeraj; Chahdi, Ahmed; Belo, Angelica; Khurana, Sandeep; Xie, Guofeng

2011-01-01

Highlights: ► Muscarinic receptor agonists stimulated robust human colon cancer cell invasion. ► Anti-matrix metalloproteinase1 antibody pre-treatment blocks cell invasion. ► Bile acids stimulate MMP1 expression, cell migration and MMP1-dependent invasion. -- Abstract: Mammalian matrix metalloproteinases (MMPs) which degrade extracellular matrix facilitate colon cancer cell invasion into the bloodstream and extra-colonic tissues; in particular, MMP1 expression correlates strongly with advanced colon cancer stage, hematogenous metastasis and poor prognosis. Likewise, muscarinic receptor signaling plays an important role in colon cancer; muscarinic receptors are over-expressed in colon cancer compared to normal colon epithelial cells. Muscarinic receptor activation stimulates proliferation, migration and invasion of human colon cancer cells. In mouse intestinal neoplasia models genetic ablation of muscarinic receptors attenuates carcinogenesis. In the present work, we sought to link these observations by showing that MMP1 expression and activation plays a mechanistic role in muscarinic receptor agonist-induced colon cancer cell invasion. We show that acetylcholine, which robustly increases MMP1 expression, stimulates invasion of HT29 and H508 human colon cancer cells into human umbilical vein endothelial cell monolayers – this was abolished by pre-incubation with atropine, a non-selective muscarinic receptor inhibitor, and by pre-incubation with anti-MMP1 neutralizing antibody. Similar results were obtained using a Matrigel chamber assay and deoxycholyltaurine (DCT), an amidated dihydroxy bile acid associated with colon neoplasia in animal models and humans, and previously shown to interact functionally with muscarinic receptors. DCT treatment of human colon cancer cells resulted in time-dependent, 10-fold increased MMP1 expression, and DCT-induced cell invasion was also blocked by pre-treatment with anti-MMP1 antibody. This study contributes to understanding

Muscarinic receptor agonists stimulate matrix metalloproteinase 1-dependent invasion of human colon cancer cells

Energy Technology Data Exchange (ETDEWEB)

Raufman, Jean-Pierre, E-mail: jraufman@medicine.umaryland.edu [Division of Gastroenterology and Hepatology, University of Maryland School of Medicine, Baltimore, MD (United States); Cheng, Kunrong; Saxena, Neeraj; Chahdi, Ahmed; Belo, Angelica; Khurana, Sandeep; Xie, Guofeng [Division of Gastroenterology and Hepatology, University of Maryland School of Medicine, Baltimore, MD (United States)

2011-11-18

Highlights: Black-Right-Pointing-Pointer Muscarinic receptor agonists stimulated robust human colon cancer cell invasion. Black-Right-Pointing-Pointer Anti-matrix metalloproteinase1 antibody pre-treatment blocks cell invasion. Black-Right-Pointing-Pointer Bile acids stimulate MMP1 expression, cell migration and MMP1-dependent invasion. -- Abstract: Mammalian matrix metalloproteinases (MMPs) which degrade extracellular matrix facilitate colon cancer cell invasion into the bloodstream and extra-colonic tissues; in particular, MMP1 expression correlates strongly with advanced colon cancer stage, hematogenous metastasis and poor prognosis. Likewise, muscarinic receptor signaling plays an important role in colon cancer; muscarinic receptors are over-expressed in colon cancer compared to normal colon epithelial cells. Muscarinic receptor activation stimulates proliferation, migration and invasion of human colon cancer cells. In mouse intestinal neoplasia models genetic ablation of muscarinic receptors attenuates carcinogenesis. In the present work, we sought to link these observations by showing that MMP1 expression and activation plays a mechanistic role in muscarinic receptor agonist-induced colon cancer cell invasion. We show that acetylcholine, which robustly increases MMP1 expression, stimulates invasion of HT29 and H508 human colon cancer cells into human umbilical vein endothelial cell monolayers - this was abolished by pre-incubation with atropine, a non-selective muscarinic receptor inhibitor, and by pre-incubation with anti-MMP1 neutralizing antibody. Similar results were obtained using a Matrigel chamber assay and deoxycholyltaurine (DCT), an amidated dihydroxy bile acid associated with colon neoplasia in animal models and humans, and previously shown to interact functionally with muscarinic receptors. DCT treatment of human colon cancer cells resulted in time-dependent, 10-fold increased MMP1 expression, and DCT-induced cell invasion was also blocked by pre

Protease-activated receptor 2 agonist increases cell proliferation and invasion of human pancreatic cancer cells

Science.gov (United States)

XIE, LIQUN; DUAN, ZEXING; LIU, CAIJU; ZHENG, YANMIN; ZHOU, JING

2015-01-01

The aim of this study was to determine the expression of protease-activated receptor 2 (PAR-2) in the human pancreatic cancer cell line SW1990, and to evaluate its effect on cell proliferation and invasion. The expression of PAR-2 protein and mRNA in SW1990 cells was determined by immunocytochemistry and reverse transcription polymerase chain reaction (PCR), respectively. MTT and cell invasion and migration assays, as well as semi-quantitative PCR and zymography analysis, were additionally performed. PAR-2 mRNA was significantly upregulated in the cells treated with trypsin or the PAR-2 activating peptide Ser-Leu-Ile-Gly-Lys-Val (SLIGKV) (P0.05). Trypsin and SLIGKV significantly promoted SW1990 cell proliferation in a dose- and time-dependent manner (P<0.05). Compared with the control group, trypsin and SLIGKV significantly increased the mRNA expression (P<0.01) and gelatinolytic activity (P<0.01) of matrix metalloproteinase (MMP)-2. In conclusion, PAR-2 is expressed in SW1990 cells. PAR-2 activation may promote the invasion and migration of human pancreatic cancer cells by increasing MMP-2 expression. PMID:25452809

The role of the tissue microenvironment in the regulation of cancer cell motility and invasion

Directory of Open Access Journals (Sweden)

Brábek Jan

2010-09-01

Full Text Available Abstract During malignant neoplastic progression the cells undergo genetic and epigenetic cancer-specific alterations that finally lead to a loss of tissue homeostasis and restructuring of the microenvironment. The invasion of cancer cells through connective tissue is a crucial prerequisite for metastasis formation. Although cell invasion is foremost a mechanical process, cancer research has focused largely on gene regulation and signaling that underlie uncontrolled cell growth. More recently, the genes and signals involved in the invasion and transendothelial migration of cancer cells, such as the role of adhesion molecules and matrix degrading enzymes, have become the focus of research. In this review we discuss how the structural and biomechanical properties of extracellular matrix and surrounding cells such as endothelial cells influence cancer cell motility and invasion. We conclude that the microenvironment is a critical determinant of the migration strategy and the efficiency of cancer cell invasion.

Reactive oxygen species induced by Streptococcus pyogenes invasion trigger apoptotic cell death in infected epithelial cells.

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Aikawa, Chihiro; Nozawa, Takashi; Maruyama, Fumito; Tsumoto, Kohei; Hamada, Shigeyuki; Nakagawa, Ichiro

2010-06-01

Streptococcus pyogenes (group A streptococcus, GAS), one of the most common pathogens of humans, attaches and invades into human pharyngeal or skin epithelial cells. We have previously reported that induction of apoptosis is associated with GAS invasion, which induces mitochondrial dysfunction and apoptotic cell death. We demonstrate here that GAS-induced apoptosis is mediated by reactive oxygen species (ROS) production. Both the induction of apoptosis and ROS production markedly increased upon invasion of wild-type GAS strain JRS4 into HeLa cells; however, the apoptotic response was not observed in fibronectin-binding protein F1-disrupted mutant SAM1-infected cells. In Bcl-2-overexpressing HeLa cells (HBD98-2-4), the induction of apoptosis, ROS production and mitochondrial dysfunction were significantly suppressed, whereas the numbers of invaded GAS was not different between HeLa (mock cells) and the HeLa HBD98-2-4 cells. Whereas Rac1 activation occurred during GAS invasion, ROS production in GAS-infected cells was clearly inhibited by transfection with the Rac1 mutants (L37 or V12L37), but not by the dominant active mutant (V12L61) or by the dominant negative mutant (N17). These observations indicate that GAS invasion triggers ROS production through Rac1 activation and generated ROS induced mitochondrial dysfunction leading to cellular apoptosis.

TRPM7 is required for ovarian cancer cell growth, migration and invasion

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Wang, Jing; Liao, Qian-jin [The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha 410013 (China); Zhang, Yi [Department of Obstetrics and Gynaecology, Xiangya Hospital, Central South University, Changsha 410078 (China); Zhou, Hui; Luo, Chen-hui; Tang, Jie; Wang, Ying; Tang, Yan; Zhao, Min; Zhao, Xue-heng [The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha 410013 (China); Zhang, Qiong-yu [Department of Basic Medical Science, Yongzhou Vocational Technical College, Yong Zhou 425100 (China); Xiao, Ling, E-mail: lingxiaocsu@126.com [Department of Histology and Embryology, School of Basic Medical Sciences, Central South University, Changsha 410013 (China); Institute of Clinical Pharmacology, Central South University, Changsha 410018 (China)

2014-11-28

Highlights: • Silence of TRPM7 in ovarian cancer cells inhibits cell proliferation, migration and invasion. • Silence of TRPM7 decreases phosphorylation levels of Akt, Src and p38 in ovarian cancer cells. • Silence of TRPM7 increases expression of filamentous actin and number of focal adhesions in ovarian cancer cells. - Abstract: Our previous study demonstrated that the melastatin-related transient receptor potential channel 7 (TRPM7) was highly expressed in ovarian carcinomas and its overexpression was significantly associated with poor prognosis in ovarian cancer patients. However, the function of TRPM7 in ovarian cancer is mostly unknown. In this study, we examined the roles of TRPM7 in ovarian cancer cell proliferation, migration and invasion. We found that short hairpin RNA interference-mediated silence of TRPM7 significantly inhibited cell proliferation, colony formation, migration and invasion in multiple ovarian cancer cell lines. Mechanistic investigation revealed that silence of TRPM7 decreased phosphorylation levels of Akt, Src and p38 and increased filamentous actin and focal adhesion number in ovarian cancer cells. Thus, our results suggest that TRPM7 is required for proliferation, migration and invasion of ovarian cancer cells through regulating multiple signaling transduction pathways and the formation of focal adhesions.

Diversity in host clone performance within a Chinese hamster ovary cell line.

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O'Callaghan, Peter M; Berthelot, Maud E; Young, Robert J; Graham, James W A; Racher, Andrew J; Aldana, Dulce

2015-01-01

Much effort has been expended to improve the capabilities of individual Chinese hamster ovary (CHO) host cell lines to synthesize recombinant therapeutic proteins (rPs). However, given the increasing variety in rP molecular types and formats it may be advantageous to employ a toolbox of CHO host cell lines in biomanufacturing. Such a toolbox would contain a panel of hosts with specific capabilities to synthesize certain molecular types at high volumetric concentrations and with the correct product quality (PQ). In this work, we examine a panel of clonally derived host cell lines isolated from CHOK1SV for the ability to manufacture two model proteins, an IgG4 monoclonal antibody (Mab) and an Fc-fusion protein (etanercept). We show that these host cell lines vary in their relative ability to synthesize these proteins in transient and stable pool production format. Furthermore, we examined the PQ attributes of the stable pool-produced Mab and etanercept (by N-glycan ultra performance liquid chromatography (UPLC) and liquid chromatography - tandem mass spectrometry (LC-MS/MS), respectively), and uncovered substantial variation between the host cell lines in Mab N-glycan micro-heterogeneity and etanercept N and O-linked macro-heterogeneity. To further investigate the capabilities of these hosts to act as cell factories, we examined the glycosylation pathway gene expression profiles as well as the levels of endoplasmic reticulum (ER) and mitochondria in the untransfected hosts. We uncovered a moderate correlation between ER mass and the volumetric product concentration in transient and stable pool Mab production. This work demonstrates the utility of leveraging diversity within the CHOK1SV pool to identify new host cell lines with different performance characteristics. © 2015 American Institute of Chemical Engineers.

Downregulation of NEDD9 by apigenin suppresses migration, invasion, and metastasis of colorectal cancer cells

International Nuclear Information System (INIS)

Dai, Jin; Van Wie, Peter G.; Fai, Leonard Yenwong; Kim, Donghern; Wang, Lei; Poyil, Pratheeshkumar; Luo, Jia; Zhang, Zhuo

2016-01-01

Apigenin is a natural flavonoid which possesses multiple anti-cancer properties such as anti-proliferation, anti-inflammation, and anti-metastasis in many types of cancers including colorectal cancer. Neural precursor cell expressed developmentally downregulated 9 (NEDD9) is a multi-domain scaffolding protein of the Cas family which has been shown to correlate with cancer metastasis and progression. The present study investigates the role of NEDD9 in apigenin-inhibited cell migration, invasion, and metastasis of colorectal adenocarcinoma DLD1 and SW480 cells. The results show that knockdown of NEDD9 inhibited cell migration, invasion, and metastasis and that overexpression of NEDD9 promoted cell migration and invasion of DLD1 cells and SW4890 cells. Apigenin treatment attenuated NEDD9 expression at protein level, resulting in reduced phosphorylations of FAK, Src, and Akt, leading to inhibition on cell migration, invasion, and metastasis of both DLD1 and SW480 cells. The present study has demonstrated that apigenin inhibits cell migration, invasion, and metastasis through NEDD9/Src/Akt cascade in colorectal cancer cells. NEDD9 may function as a biomarker for evaluation of cancer aggressiveness and for selection of therapeutic drugs against cancer progression. - Highlights: • Apigenin inhibits migration, invasion, and metastasis of colorectal cancer cells. • Apigenin downregulates NEDD9. • Apigenin decreases phosphorylations of FAK, Src, and Akt. • Apigenin inhibits cell migration, invasion, and metastasis through NEDD9/Src/Akt.

Downregulation of NEDD9 by apigenin suppresses migration, invasion, and metastasis of colorectal cancer cells

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Dai, Jin; Van Wie, Peter G.; Fai, Leonard Yenwong; Kim, Donghern [Department of Toxicology and Cancer Biology, University of Kentucky, Lexington, KY 40536 (United States); Wang, Lei; Poyil, Pratheeshkumar [Center for Research on Environmental Disease, University of Kentucky, Lexington, KY 40536 (United States); Luo, Jia [Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY 40536 (United States); Zhang, Zhuo, E-mail: Zhuo.Zhang@uky.edu [Department of Toxicology and Cancer Biology, University of Kentucky, Lexington, KY 40536 (United States)

2016-11-15

Apigenin is a natural flavonoid which possesses multiple anti-cancer properties such as anti-proliferation, anti-inflammation, and anti-metastasis in many types of cancers including colorectal cancer. Neural precursor cell expressed developmentally downregulated 9 (NEDD9) is a multi-domain scaffolding protein of the Cas family which has been shown to correlate with cancer metastasis and progression. The present study investigates the role of NEDD9 in apigenin-inhibited cell migration, invasion, and metastasis of colorectal adenocarcinoma DLD1 and SW480 cells. The results show that knockdown of NEDD9 inhibited cell migration, invasion, and metastasis and that overexpression of NEDD9 promoted cell migration and invasion of DLD1 cells and SW4890 cells. Apigenin treatment attenuated NEDD9 expression at protein level, resulting in reduced phosphorylations of FAK, Src, and Akt, leading to inhibition on cell migration, invasion, and metastasis of both DLD1 and SW480 cells. The present study has demonstrated that apigenin inhibits cell migration, invasion, and metastasis through NEDD9/Src/Akt cascade in colorectal cancer cells. NEDD9 may function as a biomarker for evaluation of cancer aggressiveness and for selection of therapeutic drugs against cancer progression. - Highlights: • Apigenin inhibits migration, invasion, and metastasis of colorectal cancer cells. • Apigenin downregulates NEDD9. • Apigenin decreases phosphorylations of FAK, Src, and Akt. • Apigenin inhibits cell migration, invasion, and metastasis through NEDD9/Src/Akt.

SLUG promotes prostate cancer cell migration and invasion via CXCR4/CXCL12 axis.

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Uygur, Berna; Wu, Wen-Shu

2011-11-10

SLUG is a zinc-finger transcription factor of the Snail/Slug zinc-finger family that plays a role in migration and invasion of tumor cells. Mechanisms by which SLUG promotes migration and invasion in prostate cancers remain elusive. Expression level of CXCR4 and CXCL12 was examined by Western blot, RT-PCR, and qPCR analyses. Forced expression of SLUG was mediated by retroviruses, and SLUG and CXCL12 was downregulated by shRNAs-expressing lentiviruses. Migration and invasion of prostate cancer were measured by scratch-wound assay and invasion assay, respectively. We demonstrated that forced expression of SLUG elevated CXCR4 and CXCL12 expression in human prostate cancer cell lines PC3, DU145, 22RV1, and LNCaP; conversely, reduced expression of SLUG by shRNA downregulated CXCR4 and CXCL12 expression at RNA and protein levels in prostate cancer cells. Furthermore, ectopic expression of SLUG increased MMP9 expression and activity in PC3, 22RV1, and DU-145 cells, and SLUG knockdown by shRNA downregulated MMP9 expression. We showed that CXCL12 is required for SLUG-mediated MMP9 expression in prostate cancer cells. Moreover, we found that migration and invasion of prostate cancer cells was increased by ectopic expression of SLUG and decreased by SLUG knockdown. Notably, knockdown of CXCL12 by shRNA impaired SLUG-mediated migration and invasion in prostate cancer cells. Lastly, our data suggest that CXCL12 and SLUG regulate migration and invasion of prostate cancer cells independent of cell growth. We provide the first compelling evidence that upregulation of autocrine CXCL12 is a major mechanism underlying SLUG-mediated migration and invasion of prostate cancer cells. Our findings suggest that CXCL12 is a therapeutic target for prostate cancer metastasis.

Characterization of host lymphoid cells in antibody-facilitated bone marrow chimeras

International Nuclear Information System (INIS)

McCarthy, S.A.; Griffith, I.J.; Gambel, P.; Francescutti, L.H.; Wegmann, T.G.

1985-01-01

The authors have produced stable murine antibody-facilitated (AF) chimeras by the simultaneous injection of P1 bone marrow cells and anti-P2 monoclonal antibody into normal (unirradiated) adult (P1 X P2)F1 recipients. These AF chimeras are healthy, long-lived, and exhibit no overt signs of graft-versus-host disease. They are immunocompetent and tolerant of host, P2-encoded alloantigens. Donor cell engraftment and takeover, monitored by glucosephosphate isomerase isozyme patterns, is usually complete (greater than 95%) in the peripheral blood, bone marrow, and hemopoietic stem cell compartments of long-term (greater than 3 months posttransplantation) AF chimeras. The authors report here, however, that splenic, lymph node, and thymic leukocytes of AF chimeras represent donor/host chimeric populations. Spleen cell populations of AF chimeras exhibit substantial chimera-to-chimera variation in the preponderant residual host cell type(s) present. Interpretations of the implications of these findings are discussed

Targeting Src family kinases inhibits bevacizumab-induced glioma cell invasion.

Directory of Open Access Journals (Sweden)

Deborah Huveldt

Full Text Available Anti-VEGF antibody therapy with bevacizumab provides significant clinical benefit in patients with recurrent glioblastoma multiforme (GBM. Unfortunately, progression on bevacizumab therapy is often associated with a diffuse disease recurrence pattern, which limits subsequent therapeutic options. Therefore, there is an urgent need to understand bevacizumab's influence on glioma biology and block it's actions towards cell invasion. To explore the mechanism(s of GBM cell invasion we have examined a panel of serially transplanted human GBM lines grown either in short-term culture, as xenografts in mouse flank, or injected orthotopically in mouse brain. Using an orthotopic xenograft model that exhibits increased invasiveness upon bevacizumab treatment, we also tested the effect of dasatinib, a broad spectrum SFK inhibitor, on bevacizumab-induced invasion.We show that 1 activation of Src family kinases (SFKs is common in GBM, 2 the relative invasiveness of 17 serially transplanted GBM xenografts correlates strongly with p120 catenin phosphorylation at Y228, a Src kinase site, and 3 SFK activation assessed immunohistochemically in orthotopic xenografts, as well as the phosphorylation of downstream substrates occurs specifically at the invasive tumor edge. Further, we show that SFK signaling is markedly elevated at the invasive tumor front upon bevacizumab administration, and that dasatinib treatment effectively blocked the increased invasion induced by bevacizumab.Our data are consistent with the hypothesis that the increased invasiveness associated with anti-VEGF therapy is due to increased SFK signaling, and support testing the combination of dasatinib with bevacizumab in the clinic.

Nitrosoureas inhibit the stathmin-mediated migration and invasion of malignant glioma cells.

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Liang, Xing-Jie; Choi, Yong; Sackett, Dan L; Park, John K

2008-07-01

Malignant gliomas are the most common primary intrinsic brain tumors and are highly lethal. The widespread migration and invasion of neoplastic cells from the initial site of tumor formation into the surrounding brain render these lesions refractory to definitive surgical treatment. Stathmin, a microtubule-destabilizing protein that mediates cell cycle progression, can also regulate directed cell movement. Nitrosoureas, traditionally viewed as DNA alkylating agents, can also covalently modify proteins such as stathmin. We therefore sought to establish a role for stathmin in malignant glioma cell motility, migration, and invasion and determine the effects of nitrosoureas on these cell movement-related processes. Scratch wound-healing recovery, Boyden chamber migration, Matrigel invasion, and organotypic slice invasion assays were performed before and after the down-regulation of cellular stathmin levels and in the absence and presence of sublethal nitrosourea ([1-(2-chloroethyl)-3-cyclohexyl-l-nitrosourea]; CCNU) concentrations. We show that decreases in stathmin expression lead to significant decreases in malignant glioma cell motility, migration, and invasion. CCNU, at a concentration of 10 micromol/L, causes similar significant decreases, even in the absence of any effects on cell viability. The direct inhibition of stathmin by CCNU is likely a contributing factor. These findings suggest that the inhibition of stathmin expression and function may be useful in limiting the spread of malignant gliomas within the brain, and that nitrosoureas may have therapeutic benefits in addition to their antiproliferative effects.

Nitrosoureas Inhibit the Stathmin Mediated Migration and Invasion of Malignant Glioma Cells

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Liang, Xing-Jie; Choi, Yong; Sackett, Dan L.; Park, John K.

2008-01-01

Malignant gliomas are the most common primary intrinsic brain tumors and are highly lethal. The widespread migration and invasion of neoplastic cells from the initial site of tumor formation into the surrounding brain render these lesions refractory to definitive surgical treatment. Stathmin, a microtubule destabilizing protein that mediates cell cycle progression, can also regulate directed cell movement. Nitrosoureas, traditionally viewed as DNA alkylating agents, can also covalently modify proteins such as stathmin. We therefore sought to establish a role for stathmin in malignant glioma cell motility, migration, and invasion and determine the effects of nitrosoureas on these cell movement related processes. Scratch-wound healing recovery, Boyden chamber migration, Matrigel invasion, and organotypic slice invasion assays were performed before and after the down regulation of cellular stathmin levels and in the absence and presence of sub-lethal nitrosourea (CCNU; [1-(2-chloroethyl)-3-cyclohexyl-l-nitrosourea]) concentrations. We demonstrate that decreases in stathmin expression lead to significant decreases in malignant glioma cell motility, migration, and invasion. CCNU, at a concentration of 10 μM, causes similar significant decreases, even in the absence of any effects on cell viability. The direct inhibition of stathmin by CCNU is likely a contributing factor. These findings suggest that the inhibition of stathmin expression and function may be useful in limiting the spread of malignant gliomas within the brain and that nitrosoureas may have therapeutic benefits in addition to their anti-proliferative effects. PMID:18593927

The Effects of NDRG2 Overexpression on Cell Proliferation and Invasiveness of SW48 Colorectal Cancer Cell Line.

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Golestan, Ali; Mojtahedi, Zahra; Ghalamfarsa, Ghasem; Hamidinia, Maryam; Takhshid, Mohammad Ali

2015-09-01

Colorectal cancer (CRC) is one of the most common causes of cancer-related death in the world. The expression of N-myc downstream-regulated gene 2 (NDRG2) is down-regulated in CRC. The aim of this study was to investigate the effect of NDRG2 overexpression on cell proliferation and invasive potential of SW48 cells. SW48 cells were transfected with a plasmid overexpressing NDRG2. After stable transfection, the effect of NDRG2 overexpression on cell proliferation was evaluated by MTT assay. The effects of NDRG2 overexpression on cell migration, invasion and cell motility and matrix metalloproteinase 9 (MMP9) activities were also investigated using matrigel transwell assay, wound healing assay and gelatin zymography, respectively. MTT assay showed that overexpression of NDRG2 caused attenuation of SW48 cell proliferation. Transwell and wound healing assay revealed that NDRG2 overexpression led to inhibition of migration, invasion, and motility of SW48 cells. The overexpression of NDRG2 also reduced the activity of secreted MMP-9. The results of this study suggest that NDRG2 overexpression inhibits proliferation and invasive potential of SW48 cells, which likely occurs via suppression of MMP-9 activity.

miR-664 negatively regulates PLP2 and promotes cell proliferation and invasion in T-cell acute lymphoblastic leukaemia

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Zhu, Hong; Miao, Mei-hua; Ji, Xue-qiang; Xue, Jun; Shao, Xue-jun, E-mail: xuejunshao@hotmail.com

2015-04-03

MicroRNAs (miRNAs) play important roles in the pathogenesis of many types of cancers by negatively regulating gene expression at posttranscriptional level. However, the role of microRNAs in leukaemia, particularly T-cell acute lymphoblastic leukaemia (T-ALL), has remained elusive. Here, we identified miR-664 and its predicted target gene PLP2 were differentially expressed in T-ALL using bioinformatics methods. In T-ALL cell lines, CCK-8 proliferation assay indicated that the cell proliferation was promoted by miR-664, while miR-664 inhibitor could significantly inhibited the proliferation. Moreover, migration and invasion assay showed that overexpression of miR-664 could significantly promoted the migration and invasion of T-ALL cells, whereas miR-664 inhibitor could reduce cell migration and invasion. luciferase assays confirmed that miR-664 directly bound to the 3'untranslated region of PLP2, and western blotting showed that miR-664 suppressed the expression of PLP2 at the protein levels. This study indicated that miR-664 negatively regulates PLP2 and promotes proliferation and invasion of T-ALL cell lines. Thus, miR-664 may represent a potential therapeutic target for T-ALL intervention. - Highlights: • miR-664 mimics promote the proliferation and invasion of T-ALL cells. • miR-664 inhibitors inhibit the proliferation and invasion of T-ALL cells. • miR-664 targets 3′ UTR of PLP2 in T-ALL cells. • miR-664 negatively regulates PLP2 in T-ALL cells.

Construction of a multiple fluorescence labeling system for use in co-invasion studies of Listeria monocytogenes

DEFF Research Database (Denmark)

Andersen, Jens Bo; Roldgaard, Bent; Lindner, A. B.

2006-01-01

strains at the single cell level by use of fluorescence microscopy. More than 90% of the L. monocytogenes host cells maintained the fluorescence tags for 40 generations. The fluorescence tags did not alter the invasive capacity of the L. monocytogenes cells in a traditional Caco-2 cell invasion assay......, and visual discrimination between invaded bacteria carrying different fluorescent labels inside the cells was possible. Conclusion The constructed fluorescent marker system is stable, easy to use, does not affect the virulence of L. monocytogenes in Caco-2 cell assays, and allows discrimination between...... deviations in the observed capacity for infection when animal models are used. One way to circumvent this problem is to carry out virulence studies as competition assays between 2 or more strains. This, however, requires invasion-neutral markers that enable easy discrimination between the different strains...

Management of periorbital basal cell carcinoma with orbital invasion.

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Sun, Michelle T; Wu, Albert; Figueira, Edwin; Huilgol, Shyamala; Selva, Dinesh

2015-11-01

Basal cell carcinoma (BCC) is the most common eyelid malignancy; however, orbital invasion by periocular BCC is rare, and management remains challenging. Established risk factors for orbital invasion by BCC include male gender, advanced age, medial canthal location, previous recurrences, large tumor size, aggressive histologic subtype and perineural invasion. Management requires a multidisciplinary approach with orbital exenteration remaining the treatment of choice. Globe-sparing treatment may be appropriate in selected patients and radiotherapy and chemotherapy are often used as adjuvant therapies for advanced or inoperable cases, although the evidence remains limited. We aim to summarize the presentation and treatment of BCC with orbital invasion to better guide the management of this complex condition.

Theileria parasites secrete a prolyl isomerase to maintain host leukocyte transformation.

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Marsolier, J; Perichon, M; DeBarry, J D; Villoutreix, B O; Chluba, J; Lopez, T; Garrido, C; Zhou, X Z; Lu, K P; Fritsch, L; Ait-Si-Ali, S; Mhadhbi, M; Medjkane, S; Weitzman, J B

2015-04-16

Infectious agents develop intricate mechanisms to interact with host cell pathways and hijack their genetic and epigenetic machinery to change host cell phenotypic states. Among the Apicomplexa phylum of obligate intracellular parasites, which cause veterinary and human diseases, Theileria is the only genus that transforms its mammalian host cells. Theileria infection of bovine leukocytes induces proliferative and invasive phenotypes associated with activated signalling pathways, notably JNK and AP-1 (ref. 2). The transformed phenotypes are reversed by treatment with the theilericidal drug buparvaquone. We used comparative genomics to identify a homologue of the peptidyl-prolyl isomerase PIN1 in T. annulata (TaPIN1) that is secreted into the host cell and modulates oncogenic signalling pathways. Here we show that TaPIN1 is a bona fide prolyl isomerase and that it interacts with the host ubiquitin ligase FBW7, leading to its degradation and subsequent stabilization of c-JUN, which promotes transformation. We performed in vitro and in silico analysis and in vivo zebrafish xenograft experiments to demonstrate that TaPIN1 is directly inhibited by the anti-parasite drug buparvaquone (and other known PIN1 inhibitors) and is mutated in a drug-resistant strain. Prolyl isomerization is thus a conserved mechanism that is important in cancer and is used by Theileria parasites to manipulate host oncogenic signalling.

Co-ordinate regulation of Salmonella typhimurium invasion genes by environmental and regulatory factors is mediated by control of hilA expression.

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Bajaj, V; Lucas, R L; Hwang, C; Lee, C A

1996-11-01

During infection of their hosts, salmonellae enter intestinal epithelial cells. It has been proposed that when Salmonella typhimurium is present in the intestinal lumen, several environmental and regulatory conditions modulate the expression of invasion factors required for bacterial entry into host cells. We report here that the expression of six different S. typhimurium invasion genes encoded on SPI1 (Salmonella pathogenicity island 1) is co-ordinately regulated by oxygen, osmolarity, pH, PhoPQ, and HilA. HilA is a transcriptional activator of the OmpR/ToxR family that is also encoded on SPI1. We have found that HilA plays a central role in the co-ordinated regulation of invasion genes by environmental and regulatory conditions. HilA can activate the expression of two invasion gene-lacZY fusions on reporter plasmids in Escherichia coll, suggesting that HilA acts directly at invasion-gene promoters in S. typhimurium. We have found that the regulation of invasion genes by oxygen, osmolarity, pH, and PhoPQ is indirect and is mediated by regulation of hilA expression by these environmental and regulatory factors. We hypothesize that the complex and co-ordinate regulation of Invasion genes by HilA is an important feature of salmonella pathogenesis and allows salmonellae to enter intestinal epithelial cells.

Identification of NDRG1-regulated genes associated with invasive potential in cervical and ovarian cancer cells

International Nuclear Information System (INIS)

Zhao, Gang; Chen, Jiawei; Deng, Yanqiu; Gao, Feng; Zhu, Jiwei; Feng, Zhenzhong; Lv, Xiuhong; Zhao, Zheng

2011-01-01

Highlights: → NDRG1 was knockdown in cervical and ovarian cancer cell lines by shRNA technology. → NDRG1 knockdown resulted in increased cell invasion activities. → Ninety-six common deregulated genes in both cell lines were identified by cDNA microarray. → Eleven common NDRG1-regulated genes might enhance cell invasive activity. → Regulation of invasion by NDRG1 is an indirect and complicated process. -- Abstract: N-myc downstream regulated gene 1 (NDRG1) is an important gene regulating tumor invasion. In this study, shRNA technology was used to suppress NDRG1 expression in CaSki (a cervical cancer cell line) and HO-8910PM (an ovarian cancer cell line). In vitro assays showed that NDRG1 knockdown enhanced tumor cell adhesion, migration and invasion activities without affecting cell proliferation. cDNA microarray analysis revealed 96 deregulated genes with more than 2-fold changes in both cell lines after NDRG1 knockdown. Ten common upregulated genes (LPXN, DDR2, COL6A1, IL6, IL8, FYN, PTP4A3, PAPPA, ETV5 and CYGB) and one common downregulated gene (CLCA2) were considered to enhance tumor cell invasive activity. BisoGenet network analysis indicated that NDRG1 regulated these invasion effector genes/proteins in an indirect manner. Moreover, NDRG1 knockdown also reduced pro-invasion genes expression such as MMP7, TMPRSS4 and CTSK. These results suggest that regulation of invasion and metastasis by NDRG1 is a highly complicated process.

Effects of actonomycin D and ultraviolet irradiation on multiplication of brome mosaic virus in host and non-host cells

International Nuclear Information System (INIS)

Maekawa, K.; Furusawa, I.; Okuno, T.

1981-01-01

The modes of multiplication of brome mosaic virus (BMV) were compared in protoplasts isolated from host and non-host plants. BMV actively multiplied in the leaves and isolated mesophyll protoplasts of barley, a host of BMV. BMV multiplication in barley protoplasts was inhibited by addition of actinomycin D immediately after inoculation or by u.v. irradiation of the protoplasts before inoculation. In contrast, although BMV could not multiply in leaves of radish and turnip (non-hosts for BMV) it multiplied at a low level in protoplasts isolated from these two plant species. Moreover, u.v. irradiation, or the addition of actinomycin D, enhanced multiplication of BMV in radish and turnip protoplasts. These results suggest that (i) in the host cells replication of BMV is dependent on cellular metabolism of nucleic acid and protein, and (ii) in the non-host cells a substance(s) inhibitory to replication of BMV is synthesized. (author)

Chemokine CXCL16 Expression Suppresses Migration and Invasiveness and Induces Apoptosis in Breast Cancer Cells

Directory of Open Access Journals (Sweden)

Yeying Fang

2014-01-01

Full Text Available Background. Increasing evidence argues that soluble CXCL16 promotes proliferation, migration, and invasion of cancer cells in vitro. However, the role of transmembrane or cellular CXCL16 in cancer remains relatively unknown. In this study, we determine the function of cellular CXCL16 as tumor suppressor in breast cancer cells. Methods. Expression of cellular CXCL16 in breast cancer cell lines was determined at both RNA and protein levels. In vitro and in vivo studies that overexpressed or downregulated CXCL16 were conducted in breast cancer cells. Results. We report differential expression of cellular CXCL16 in breast cancer cell lines that was negatively correlated with cell invasiveness and migration. Overexpression of CXCL16 in MDA-MB-231 cells led to a decrease in cell invasion and migration and induced apoptosis of the cells; downregulation of CXCL16 in MCF-7 cells increased cell migration and invasiveness. Consistent with the in vitro data, CXCL16 overexpression inhibited tumorigenesis in vivo. Conclusions. Cellular CXCL16 suppresses invasion and metastasis of breast cancer cells in vitro and inhibits tumorigenesis in vivo. Targeting of cellular CXCL16 expression is a potential therapeutic strategy for breast cancer.

Adipose-derived mesenchymal stem cells promote cell proliferation and invasion of epithelial ovarian cancer

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Chu, Yijing; Tang, Huijuan; Guo, Yan; Guo, Jing; Huang, Bangxing; Fang, Fang; Cai, Jing, E-mail: caijingmmm@hotmail.com; Wang, Zehua, E-mail: zehuawang@163.net

2015-09-10

Adipose-derived mesenchymal stem cell (ADSC) is an important component of tumor microenvironment. However, whether ADSCs have a hand in ovarian cancer progression remains unclear. In this study, we investigated the impact of human ADSCs derived from the omentum of normal donors on human epithelial ovarian cancer (EOC) cells in vitro and in vivo. Direct and indirect co-culture models including ADSCs and human EOC cell lines were established and the effects of ADSCs on EOC cell proliferation were evaluated by EdU incorporation and flow cytometry. Transwell migration assays and detection of MMPs were performed to assess the invasion activity of EOC cells in vitro. Mouse models were established by intraperitoneal injection of EOC cells with or without concomitant ADSCs to investigate the role of ADSCs in tumor progression in vivo. We found that ADSCs significantly promoted proliferation and invasion of EOC cells in both direct and indirect co-culture assays. In addition, after co-culture with ADSCs, EOC cells secreted higher levels of matrix metalloproteinases (MMPs), and inhibition of MMP2 and MMP9 partially relieved the tumor-promoting effects of ADSCs in vitro. In mouse xenograft models, we confirmed that ADSCs promoted EOC growth and metastasis and elevated the expression of MMP2 and MMP9. Our findings indicate that omental ADSCs play a promotive role during ovarian cancer progression. - Highlights: • Omental adipose derived stem cells enhanced growth and invasion properties of ovarian cancer cells. • Adipose derived stem cells promoted the growth and metastasis of ovarian cancer in mice models. • Adipose derived stem cells promoted MMPs expression and secretion of ovarian cancer cells. • Elevated MMPs mediated the tumor promoting effects of ADSCs.

Adipose-derived mesenchymal stem cells promote cell proliferation and invasion of epithelial ovarian cancer

International Nuclear Information System (INIS)

Chu, Yijing; Tang, Huijuan; Guo, Yan; Guo, Jing; Huang, Bangxing; Fang, Fang; Cai, Jing; Wang, Zehua

2015-01-01

Adipose-derived mesenchymal stem cell (ADSC) is an important component of tumor microenvironment. However, whether ADSCs have a hand in ovarian cancer progression remains unclear. In this study, we investigated the impact of human ADSCs derived from the omentum of normal donors on human epithelial ovarian cancer (EOC) cells in vitro and in vivo. Direct and indirect co-culture models including ADSCs and human EOC cell lines were established and the effects of ADSCs on EOC cell proliferation were evaluated by EdU incorporation and flow cytometry. Transwell migration assays and detection of MMPs were performed to assess the invasion activity of EOC cells in vitro. Mouse models were established by intraperitoneal injection of EOC cells with or without concomitant ADSCs to investigate the role of ADSCs in tumor progression in vivo. We found that ADSCs significantly promoted proliferation and invasion of EOC cells in both direct and indirect co-culture assays. In addition, after co-culture with ADSCs, EOC cells secreted higher levels of matrix metalloproteinases (MMPs), and inhibition of MMP2 and MMP9 partially relieved the tumor-promoting effects of ADSCs in vitro. In mouse xenograft models, we confirmed that ADSCs promoted EOC growth and metastasis and elevated the expression of MMP2 and MMP9. Our findings indicate that omental ADSCs play a promotive role during ovarian cancer progression. - Highlights: • Omental adipose derived stem cells enhanced growth and invasion properties of ovarian cancer cells. • Adipose derived stem cells promoted the growth and metastasis of ovarian cancer in mice models. • Adipose derived stem cells promoted MMPs expression and secretion of ovarian cancer cells. • Elevated MMPs mediated the tumor promoting effects of ADSCs

NEDD 4 binding protein 2-like 1 promotes cancer cell invasion in oral squamous cell carcinoma.

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Sasahira, Tomonori; Kurihara, Miyako; Nishiguchi, Yukiko; Fujiwara, Rina; Kirita, Tadaaki; Kuniyasu, Hiroki

2016-08-01

Head and neck cancer, including oral squamous cell carcinoma, is the sixth most common cancer worldwide. Although cancer cell invasion and metastasis are crucial for tumor progression, detailed molecular mechanisms underlying the invasion and metastasis of oral squamous cell carcinoma are unclear. Comparison of transcriptional profiles using a cDNA microarray demonstrated that N4BP2L1, a novel oncogene expressed by neural precursor cells, is involved in oral squamous cell carcinoma. Expression of N4BP2L1 in oral squamous cell carcinoma is regulated by activation of miR-448 and is higher than in normal oral mucosa. Knockdown of N4BP2L1 and upregulation of miR-448 significantly reduced the invasive potential of oral squamous cell carcinoma cells. We studied N4BP2L1 expression in 187 cases of oral squamous cell carcinoma and found its overexpression to be significantly associated with nodal metastasis (P = 0.0155) and poor prognosis (P = 0.0136). Expression of miR-448 was found to be inversely associated with that of N4BP2L1 (P = 0.0019). Cox proportional hazards analysis identified N4BP2L1 expression as an independent predictor of disease-free survival (P = 0.0349). Our results suggest that N4BP2L1 plays an important role in tumor cell invasion in oral squamous cell carcinoma. Further studies on expression of N4BP2L1 may provide new insight into its function and clarify its potential as biomarker in human oral cancer.

β-Catenin promotes cell proliferation, migration, and invasion but induces apoptosis in renal cell carcinoma

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Yang CM

2017-02-01

Full Text Available Chun-ming Yang,1 Shan Ji,2 Yan Li,3 Li-ye Fu,3 Tao Jiang,3 Fan-dong Meng31Department of Urology, The First Affiliated Hospital, China Medical University, 2Department of Endocrinology, The Fifth People’s Hospital of Shenyang, 3Department of Biotherapy, Cancer Research Institute, The First Affiliated Hospital, China Medical University, Shenyang, ChinaAbstract: β-Catenin (CTNNB1 gene coding protein is a component of the Wnt signaling pathway that has been shown to play an important role in the formation of certain cancers. Abnormal accumulation of CTNNB1 contributes to most cancers. This research studied the involvement of β-catenin in renal cell carcinoma (RCC cell proliferation, apoptosis, migration, and invasion. Proliferation, cell cycle, and apoptosis were analyzed by using Cell Counting Kit-8 and by flow cytometry. Migration and invasion assays were measured by transwell analysis. Real-time polymerase chain reaction and Western blot analysis were used to detect the expression of CTNNB1, ICAM-1, VCAM-1, CXCR4, and CCL18 in RCC cell lines. It was found that CTNNB1 knockdown inhibited cell proliferation, migration, and invasion and induced apoptosis of A-498 cells. CTNNB1 overexpression promoted cell proliferation, migration, and invasion and inhibited apoptosis of 786-O cells. Moreover, knockdown of CTNNB1 decreased the levels of ICAM-1, VCAM-1, CXCR4, and CCL18 expression, but CTNNB1 overexpression increased the expression of ICAM-1, VCAM-1, CXCR4, and CCL18. Further in vivo tumor formation study in nude mice indicated that inhibition of CTNNB1 delayed the progress of tumor formation through inhibiting PCNA and Ki67 expression. These results indicate that CTNNB1 could act as an oncogene and may serve as a promising therapeutic strategy for RCC.Keywords: kidney cancer, oncogene, β-catenin, survival time, tumor migration-related protein

Effects of a fish oil-based emulsion on rat hepatoma cell invasion in culture.

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Hagi, Akifumi; Nakayama, Mitsuo; Miura, Yutaka; Yagasaki, Kazumi

2007-01-01

Total parenteral nutrition containing a lipid emulsion is often employed after surgical tumor resection. This study investigated the effects of a fish oil-based infusion on rat hepatoma cell invasion. Rat ascites hepatoma cell line AH109A was precultured with a fish oil-based or safflower oil-based emulsion for 48 h. Changes in membranous fatty acid composition were evaluated by gas chromatography. The invasiveness of hepatoma cells was assessed by coculturing with mesentery-derived mesothelial cells. To examine ex vivo effects of the fish oil-based infusion on hepatoma invasion, sera were prepared from rats infused with fish oil- or safflower oil-based emulsion and the effects of these sera were assessed. To clarify the mechanism of inhibition of invasion by the fish oil-based emulsion, the effects of prostaglandin (PG) E(2) and PGE(3) on invasion were examined. Pretreatment with the fish oil-based emulsion reduced invasiveness without affecting growth compared with the safflower oil-based emulsion. Pretreatment with the sera from rats infused with the fish oil-based emulsion also reduced invasiveness compared with the sera from rats infused with the safflower oil-based emulsion. The addition of PGE(2) eliminated the inhibitory effect of the fish oil-based emulsion, and the addition of PGE(3) reduced the invasiveness of hepatoma cells pretreated with the safflower oil-based emulsion. These results suggest that the fish oil-based emulsion may have anti-invasive effects. Changes in the membranous fatty acid composition and consequent changes in the prostaglandins produced may be involved in this inhibitory effect.

Inhibitory effect of maple syrup on the cell growth and invasion of human colorectal cancer cells.

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Yamamoto, Tetsushi; Uemura, Kentaro; Moriyama, Kaho; Mitamura, Kuniko; Taga, Atsushi

2015-04-01

Maple syrup is a natural sweetener consumed by individuals of all ages throughout the world. Maple syrup contains not only carbohydrates such as sucrose but also various components such as organic acids, amino acids, vitamins and phenolic compounds. Recent studies have shown that these phenolic compounds in maple syrup may possess various activities such as decreasing the blood glucose level and an anticancer effect. In this study, we examined the effect of three types of maple syrup, classified by color, on the cell proliferation, migration and invasion of colorectal cancer (CRC) cells in order to investigate whether the maple syrup is suitable as a phytomedicine for cancer treatment. CRC cells that were administered maple syrup showed significantly lower growth rates than cells that were administered sucrose. In addition, administration of maple syrup to CRC cells caused inhibition of cell invasion, while there was no effect on cell migration. Administration of maple syrup clearly inhibited AKT phosphorylation, while there was no effect on ERK phosphorylation. These data suggest that maple syrup might inhibit cell proliferation and invasion through suppression of AKT activation and be suitable as a phytomedicine for CRC treatment, with fewer adverse effects than traditional chemotherapy.

The integrin alphav beta3 increases cellular stiffness and cytoskeletal remodeling dynamics to facilitate cancer cell invasion

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Mierke, Claudia Tanja

2013-01-01

The process of cancer cell invasion through the extracellular matrix (ECM) of connective tissue plays a prominent role in tumor progression and is based fundamentally on biomechanics. Cancer cell invasion usually requires cell adhesion to the ECM through the cell-matrix adhesion receptors integrins. The expression of the αvβ3 integrin is increased in several tumor types and is consistently associated with increased metastasis formation in patients. The hypothesis was that the αvβ3 integrin expression increases the invasiveness of cancer cells through increased cellular stiffness, and increased cytoskeletal remodeling dynamics. Here, the invasion of cancer cells with different αvβ3 integrin expression levels into dense three-dimensional (3D) ECMs has been studied. Using a cell sorter, two subcell lines expressing either high or low amounts of αvβ3 integrins (αvβ3high or αvβ3low cells, respectively) have been isolated from parental MDA-MB-231 breast cancer cells. αvβ3high cells showed a threefold increased cell invasion compared to αvβ3low cells. Similar results were obtained for A375 melanoma, 786-O kidney and T24 bladder carcinoma cells, and cells in which the β3 integrin subunit was knocked down using specific siRNA. To investigate whether contractile forces are essential for αvβ3 integrin-mediated increased cellular stiffness and subsequently enhanced cancer cell invasion, invasion assays were performed in the presence of myosin light chain kinase inhibitor ML-7 and Rho kinase inhibitor Y27632. Indeed, cancer cell invasiveness was reduced after addition of ML-7 and Y27632 in αvβ3high cells but not in αvβ3low cells. Moreover, after addition of the contractility enhancer calyculin A, an increase in pre-stress in αvβ3low cells was observed, which enhanced cellular invasiveness. In addition, inhibition of the Src kinase, STAT3 or Rac1 strongly reduced the invasiveness of αvβ3high cells, whereas the invasiveness of β3 specific knock

The integrin alphav beta3 increases cellular stiffness and cytoskeletal remodeling dynamics to facilitate cancer cell invasion

International Nuclear Information System (INIS)

Mierke, Claudia Tanja

2013-01-01

The process of cancer cell invasion through the extracellular matrix (ECM) of connective tissue plays a prominent role in tumor progression and is based fundamentally on biomechanics. Cancer cell invasion usually requires cell adhesion to the ECM through the cell-matrix adhesion receptors integrins. The expression of the αvβ3 integrin is increased in several tumor types and is consistently associated with increased metastasis formation in patients. The hypothesis was that the αvβ3 integrin expression increases the invasiveness of cancer cells through increased cellular stiffness, and increased cytoskeletal remodeling dynamics. Here, the invasion of cancer cells with different αvβ3 integrin expression levels into dense three-dimensional (3D) ECMs has been studied. Using a cell sorter, two subcell lines expressing either high or low amounts of αvβ3 integrins (αvβ3 high or αvβ3 low cells, respectively) have been isolated from parental MDA-MB-231 breast cancer cells. αvβ3 high cells showed a threefold increased cell invasion compared to αvβ3 low cells. Similar results were obtained for A375 melanoma, 786-O kidney and T24 bladder carcinoma cells, and cells in which the β3 integrin subunit was knocked down using specific siRNA. To investigate whether contractile forces are essential for αvβ3 integrin-mediated increased cellular stiffness and subsequently enhanced cancer cell invasion, invasion assays were performed in the presence of myosin light chain kinase inhibitor ML-7 and Rho kinase inhibitor Y27632. Indeed, cancer cell invasiveness was reduced after addition of ML-7 and Y27632 in αvβ3 high cells but not in αvβ3 low cells. Moreover, after addition of the contractility enhancer calyculin A, an increase in pre-stress in αvβ3 low cells was observed, which enhanced cellular invasiveness. In addition, inhibition of the Src kinase, STAT3 or Rac1 strongly reduced the invasiveness of αvβ3 high cells, whereas the invasiveness of β3 specific knock

URG11 Regulates Prostate Cancer Cell Proliferation, Migration, and Invasion

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Bin Pan

2018-01-01

Full Text Available Upregulated gene 11 (URG11, a new gene upregulated by hepatitis B virus X protein, is involved in the development and progression of several tumors, including liver, stomach, lung, and colon cancers. However, the role of URG11 in prostate cancer remains yet to be elucidated. By determined expression in human prostate cancer tissues, URG11 was found significantly upregulated and positively correlated with the severity of prostate cancer, compared with that in benign prostatic hyperplasia tissues. Further, the mRNA and protein levels of URG11 were significantly upregulated in human prostate cancer cell lines (DU145, PC3, and LNCaP, compared with human prostate epithelial cell line (RWPE-1. Moreover, by the application of siRNA against URG11, the proliferation, migration, and invasion of prostate cancer cells were markedly inhibited. Genetic knockdown of URG11 also induced cell cycle arrest at G1/S phase, induced apoptosis, and decreased the expression level of β-catenin in prostate cancer cells. Overexpression of URG11 promoted the expression of β-catenin, the growth, the migration, and invasion ability of prostate cancer cells. Taken together, this study reveals that URG11 is critical for the proliferation, migration, and invasion in prostate cancer cells, providing the evidence of URG11 to be a novel potential therapeutic target of prostate cancer.

Targeting of Survivin Pathways by YM155 Inhibits Cell Death and Invasion in Oral Squamous Cell Carcinoma Cells.

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Zhang, Wei; Liu, Yuan; Li, Yu Feng; Yue, Yun; Yang, Xinghua; Peng, Lin

2016-01-01

Specific overexpression in cancer cells and evidence of oncogenic functions make Survivin an attractive target in cancer therapy. The small molecule compound YM155 has been described as the first "Survivin suppressant" but molecular mechanisms involved in its biological activity and its clinical potential remain obscure. Survivin protein plays critical roles in oral squamous cell carcinoma (OSCC), suggesting that YM155 would be extremely valuable for OSCC. In this study, we tested our hypothesis whether YM155 could be an effective inhibitor of cell growth, invasion and angiogenesis in oral squamous cell carcinoma (OSCC) cells. SCC9 and SCC25 were treated with different concentration of YM155 for indicated time. Using MTT assay and flow cytometry analysis to detect cell growth and apoptosis; Using transwell and Wound healing assay to detect migration and invasion; Using reverse transcription-PCR, Western blotting and electrophoretic mobility shift assay for measuring gene and protein expression, and DNA binding activity of NF-x03BA;B. YM155 inhibited survivin-rich expressed SCC9 cell growth in a dose- and time dependent manner. This was accompanied by increased apoptosis and concomitant attenuation of NF-x03BA;B and downregulation of NF-x03BA;B downstream genes MMP-9, resulting in the inhibition of SCC9 cell migration and invasion in vitro and caused antitumor activity and anti metastasis in vivo. YM155 treatment did not affect cell growth, apoptosis and invasion of surviving-poor expressed SCC25 cells in vitro. YM155 is a potent inhibitor of progression of SCC9 cells, which could be due to attenuation of survivin signaling processes. Our findings provide evidence showing that YM155 could act as a small molecule survivin inhibitor on survivin-rich expressed SCC9 cells in culture as well as when grown as tumor in a xenograft model. We also suggest that survivin could be further developed as a potential therapeutic agent for the treatment of survivin-rich expressed

NF-{kappa}B p50 promotes tumor cell invasion through negative regulation of invasion suppressor gene CRMP-1 in human lung adenocarcinoma cells

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Ming, Gao [Cancer Research Center, College of Medicine, National Taiwan University, Taipei, Taiwan (China); National Center of Excellence for Clinical Trial and Research, National Taiwan University, Hospital, Taipei, Taiwan (China); Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan (China); Yeh, P Y [Cancer Research Center, College of Medicine, National Taiwan University, Taipei, Taiwan (China); Department of Oncology, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei 10016, Taiwan (China); Lu, Y -S [Cancer Research Center, College of Medicine, National Taiwan University, Taipei, Taiwan (China); National Center of Excellence for Clinical Trial and Research, National Taiwan University, Hospital, Taipei, Taiwan (China); Department of Oncology, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei 10016, Taiwan, ROC (China); Chang, W C [Cancer Research Center, College of Medicine, National Taiwan University, Taipei, Taiwan (China); Kuo, M -L [Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan (China); Cheng, A -L [Cancer Research Center, College of Medicine, National Taiwan University, Taipei, Taiwan (China); National Center of Excellence for Clinical Trial and Research, National Taiwan University, Hospital, Taipei, Taiwan (China); Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan (China); Department of Oncology, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei 10016, Taiwan (China); Department of Internal Medicine, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei 10016, Taiwan (China)], E-mail: alcheng@ntu.edu.tw

2008-11-14

Lung adenocarcinoma Cl1-5 cells were selected from parental Cl1-0 cells based on their high metastatic potential. In a previous study, CRMP-1, an invasion suppressor gene, was shown to be suppressed in Cl1-5 cells. However, the regulation of CRMP-1 expression has not been explored. In this study, we showed nuclear factor-{kappa}B controls CRMP-1 expression. The electromobility shift assay showed that while Cl1-0 cells exhibited low NF-{kappa}B activity in response to TNF-{alpha}, an abundance of basal and TNF-{alpha}-induced NF-{kappa}B-DNA complex was detected in Cl1-5 cells. Supershift-coupled EMSA and Western blotting of nuclear proteins, however, revealed p50 protein, but not classic p65/p50 heterodimer in the complex. ChIP and EMSA demonstrated that p50 binds to a {kappa}B site residing between -1753 and -1743 of the CRMP-1 promoter region. Transfection of antisense p50 gene into Cl1-5 cells increased the CRMP-1 protein level and decreased the invasive activity of Cl1-5 cells.

NF-κB p50 promotes tumor cell invasion through negative regulation of invasion suppressor gene CRMP-1 in human lung adenocarcinoma cells

International Nuclear Information System (INIS)

Gao Ming; Yeh, P.Y.; Lu, Y.-S.; Chang, W.C.; Kuo, M.-L.; Cheng, A.-L.

2008-01-01

Lung adenocarcinoma Cl1-5 cells were selected from parental Cl1-0 cells based on their high metastatic potential. In a previous study, CRMP-1, an invasion suppressor gene, was shown to be suppressed in Cl1-5 cells. However, the regulation of CRMP-1 expression has not been explored. In this study, we showed nuclear factor-κB controls CRMP-1 expression. The electromobility shift assay showed that while Cl1-0 cells exhibited low NF-κB activity in response to TNF-α, an abundance of basal and TNF-α-induced NF-κB-DNA complex was detected in Cl1-5 cells. Supershift-coupled EMSA and Western blotting of nuclear proteins, however, revealed p50 protein, but not classic p65/p50 heterodimer in the complex. ChIP and EMSA demonstrated that p50 binds to a κB site residing between -1753 and -1743 of the CRMP-1 promoter region. Transfection of antisense p50 gene into Cl1-5 cells increased the CRMP-1 protein level and decreased the invasive activity of Cl1-5 cells

Single-cell sequencing analysis characterizes common and cell-lineage-specific mutations in a muscle-invasive bladder cancer

DEFF Research Database (Denmark)

Li, Yingrui; Xu, Xun; Song, Luting

2012-01-01

sequencing of 66 individual tumor cells from a muscle-invasive bladder transitional cell carcinoma (TCC). Analyses of the somatic mutant allele frequency spectrum and clonal structure revealed that the tumor cells were derived from a single ancestral cell, but that subsequent evolution occurred, leading...... to two distinct tumor cell subpopulations. By analyzing recurrently mutant genes in an additional cohort of 99 TCC tumors, we identified genes that might play roles in the maintenance of the ancestral clone and in the muscle-invasive capability of subclones of this bladder cancer, respectively...

Intravital imaging of donor allogeneic effector and regulatory T cells with host dendritic cells during GVHD.

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Lin, Kaifeng Lisa; Fulton, LeShara M; Berginski, Matthew; West, Michelle L; Taylor, Nicholas A; Moran, Timothy P; Coghill, James M; Blazar, Bruce R; Bear, James E; Serody, Jonathan S

2014-03-06

Graft-versus-host disease (GVHD) is a systemic inflammatory response due to the recognition of major histocompatibility complex disparity between donor and recipient after hematopoietic stem cell transplantation (HSCT). T-cell activation is critical to the induction of GVHD, and data from our group and others have shown that regulatory T cells (Tregs) prevent GVHD when given at the time of HSCT. Using multiphoton laser scanning microscopy, we examined the single cell dynamics of donor T cells and dendritic cells (DCs) with or without Tregs postallogeneic transplantation. We found that donor conventional T cells (Tcons) spent very little time screening host DCs. Tcons formed stable contacts with DCs very early after transplantation and only increased velocity in the lymph node at 20 hours after transplant. We also observed that Tregs reduced the interaction time between Tcons and DCs, which was dependent on the generation of interleukin 10 by Tregs. Imaging using inducible Tregs showed similar disruption of Tcon-DC contact. Additionally, we found that donor Tregs induce host DC death and down-regulate surface proteins required for donor T-cell activation. These data indicate that Tregs use multiple mechanisms that affect host DC numbers and function to mitigate acute GVHD.

Cytotoxic Vibrio T3SS1 Rewires Host Gene Expression to Subvert Cell Death Signaling and Activate Cell Survival Networks

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De Nisco, Nicole J.; Kanchwala, Mohammed; Li, Peng; Fernandez, Jessie; Xing, Chao; Orth, Kim

2017-01-01

Bacterial effectors are potent manipulators of host signaling pathways. The marine bacterium Vibrio parahaemolyticus (V. para), delivers effectors into host cells through two type three secretion systems (T3SS). The ubiquitous T3SS1 is vital for V. para survival in the environment, whereas T3SS2 causes acute gastroenteritis in human hosts. Although the natural host is undefined, T3SS1 effectors attack highly conserved cellular processes and pathways to orchestrate non-apoptotic cell death. Much is known about how T3SS1 effectors function in isolation, but we wanted to understand how their concerted action globally affects host cell signaling. To assess the host response to T3SS1, we compared gene expression changes over time in primary fibroblasts infected with V. para that have a functional T3SS1 (T3SS1+) to those in cells infected with V. para lacking T3SS1 (T3SS1−). Overall, the host transcriptional response to both T3SS1+ and T3SS1− V. para was rapid, robust, and temporally dynamic. T3SS1 re-wired host gene expression by specifically altering the expression of 398 genes. Although T3SS1 effectors target host cells at the posttranslational level to cause cytotoxicity, network analysis indicated that V. para T3SS1 also precipitates a host transcriptional response that initially activates cell survival and represses cell death networks. The increased expression of several key pro-survival transcripts mediated by T3SS1 was dependent on a host signaling pathway that is silenced later in infection by the posttranslational action of T3SS1. Taken together, our analysis reveals a complex interplay between roles of T3SS1 as both a transcriptional and posttranslational manipulator of host cell signaling. PMID:28512145

Prostaglandins in Cancer Cell Adhesion, Migration, and Invasion

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David G. Menter

2012-01-01

Full Text Available Prostaglandins exert a profound influence over the adhesive, migratory, and invasive behavior of cells during the development and progression of cancer. Cyclooxygenase-2 (COX-2 and microsomal prostaglandin E2 synthase-1 (mPGES-1 are upregulated in inflammation and cancer. This results in the production of prostaglandin E2 (PGE2, which binds to and activates G-protein-coupled prostaglandin E1-4 receptors (EP1-4. Selectively targeting the COX-2/mPGES-1/PGE2/EP1-4 axis of the prostaglandin pathway can reduce the adhesion, migration, invasion, and angiogenesis. Once stimulated by prostaglandins, cadherin adhesive connections between epithelial or endothelial cells are lost. This enables cells to invade through the underlying basement membrane and extracellular matrix (ECM. Interactions with the ECM are mediated by cell surface integrins by “outside-in signaling” through Src and focal adhesion kinase (FAK and/or “inside-out signaling” through talins and kindlins. Combining the use of COX-2/mPGES-1/PGE2/EP1-4 axis-targeted molecules with those targeting cell surface adhesion receptors or their downstream signaling molecules may enhance cancer therapy.

Altered CXCR3 isoform expression regulates prostate cancer cell migration and invasion

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Wu Qian

2012-01-01

Full Text Available Abstract Background Carcinoma cells must circumvent the normally suppressive signals to disseminate. While often considered 'stop' signals for adherent cells, CXCR3-binding chemokines have recently been correlated positively with cancer progression though the molecular basis remains unclear. Results Here, we examined the expression and function of two CXCR3 variants in human prostate cancer biopsies and cell lines. Globally, both CXCR3 mRNA and protein were elevated in localized and metastatic human cancer biopsies compared to normal. Additionally, CXCR3A mRNA level was upregulated while CXCR3B mRNA was downregulated in these prostate cancer specimens. In contrast to normal prostate epithelial cells (RWPE-1, CXCR3A was up to half the receptor in the invasive and metastatic DU-145 and PC-3 prostate cancer cells, but not in the localized LNCaP cells. Instead of inhibiting cell migration as in RWPE-1 cells, the CXCR3 ligands CXCL4/PF4 and CXCL10/IP10 promoted cell motility and invasiveness in both DU-145 and PC-3 cells via PLCβ3 and μ-calpain activation. CXCR3-mediated diminution of cell motility in RWPE-1 cells is likely a result of cAMP upregulation and m-calpain inhibition via CXCR3B signal transduction. Interestingly, overexpression of CXCR3B in DU-145 cells decreased cell movement and invasion. Conclusion These data suggest that the aberrant expression of CXCR3A and down-regulation of CXCR3B may switch a progression "stop" to a "go" signal to promote prostate tumor metastasis via stimulating cell migration and invasion.

The conserved clag multigene family of malaria parasites: essential roles in host-pathogen interaction.

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Gupta, Ankit; Thiruvengadam, Girija; Desai, Sanjay A

2015-01-01

The clag multigene family is strictly conserved in malaria parasites, but absent from neighboring genera of protozoan parasites. Early research pointed to roles in merozoite invasion and infected cell cytoadherence, but more recent studies have implicated channel-mediated uptake of ions and nutrients from host plasma. Here, we review the current understanding of this gene family, which appears to be central to host-parasite interactions and an important therapeutic target. Published by Elsevier Ltd.

BMP2 induces PANC-1 cell invasion by MMP-2 overexpression through ROS and ERK.

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Liu, Jun; Ben, Qi-Wen; Yao, Wei-Yan; Zhang, Jian-Jun; Chen, Da-Fan; He, Xiang-Yi; Li, Lei; Yuan, Yao-Zong

2012-06-01

The emerging roles of bone morphogenetic proteins (BMPs) in the initiation and progression of multiple cancers have drawn great attention in cancer research. We hypothesized that BMP2 promotes cancer metastasis by modulating MMP-2 secretion and activity through intracellular ROS regulation and ERK activation in human pancreatic cancer. Our data show that stimulation of PANC-1 cells with BMP2 induced MMP-2 secretion and activation, associated with decreased E-cadherin expression, resulting in epithelial-to-mesenchymal transformation (EMT) and cell invasion. Blockade of ROS by the ROS scavenger, 2-MPG, abolished cell invasion, inhibited the EMT process and decreased MMP-2 expression, suggesting ROS accumulation caused an increase in MMP-2 expression in BMP2-stimulated PANC-1 cell invasion. Furthermore, treatment of PANC-1 cells with 2-MPG or ERK inhibitor PD98059 reduced the phosphorylation of ERK, resulting in attenuation of BMP2-induced cell invasion and MMP-2 activation. Taken together, these results suggest that BMP2 induces the cell invasion of PANC-1 cells by enhancing MMP-2 secretion and acting through ROS accumulation and ERK activation.

EMMPRIN contributes to the in vitro invasion of human salivary adenoid cystic carcinoma cells

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YANG, XINJIE; ZHANG, PU; MA, QIN; KONG, LIANG; LI, YUAN; LIU, BAOLIN; LEI, DELIN

2012-01-01

Extracellular matrix metalloproteinase inducer (EMMPRIN) is a transmembrane glycoprotein that is involved in tumor invasion by stimulating matrix metalloproteinase (MMP) expression. Our previous immunohistochemical study found that the expression of EMMPRIN in salivary adenoid cystic carcinoma (SACC) was positively correlated with tumor perineural and perivascular invasion. The present study was designed to further investigate the role of EMMPRIN in the invasion of SACC. Western blot results showed that EMMPRIN was upregulated in the highly metastatic SACC cell line SACC-LM, compared to SACC-83, a SACC cell line with low metastatic ability. Blocking of EMMPRIN by its antibody significantly decreased the adhesion, secretion of MMP-2 and MMP-9, and invasion activity of SACC-LM cells in vitro (PEMMPRIN may play an important role in the invasion of SACC by stimulating the expression of MMP-2 and MMP-9 in tumor and stromal cells. PMID:22200897

Staphylococcus aureus requires less virulence to establish an infection in diabetic hosts.

Science.gov (United States)

Tuchscherr, Lorena; Korpos, Èva; van de Vyver, Hélène; Findeisen, Clais; Kherkheulidze, Salome; Siegmund, Anke; Deinhardt-Emmer, Stefanie; Bach, Olaf; Rindert, Martin; Mellmann, Alexander; Sunderkötter, Cord; Peters, Georg; Sorokin, Lydia; Löffler, Bettina

2018-05-22

Staphylococcus aureus is the most frequent pathogen causing diabetic foot infections. Here, we investigated the degree of bacterial virulence required to establish invasive tissue infections in diabetic organisms. Staphylococcal isolates from diabetic and non-diabetic foot ulcers were tested for their virulence in in vitro functional assays of host cell invasion and cytotoxicity. Isolates from diabetes mellitus type I/II patients exhibited less virulence than isolates from non-diabetic patients, but were nevertheless able to establish severe infections. In some cases, non-invasive isolates were detected deep within diabetic wounds, even though the strains were non-pathogenic in cell culture models. Testing of defined isolates in murine footpad injection models revealed that both low- and high-virulent bacterial strains persisted in higher numbers in diabetic compared to non-diabetic hosts, suggesting that hyperglycemia favors bacterial survival. Additionally, the bacterial load was higher in NOD mice, which have a compromised immune system, compared to C57Bl/6 mice. Our results reveal that high as well as low-virulent staphylococcal strains are able to cause soft tissue infections and to persist in diabetic humans and mice, suggesting a reason for the frequent and endangering infections in patients with diabetes. Copyright © 2018 Elsevier GmbH. All rights reserved.

Osteoactivin regulates head and neck squamous cell carcinoma invasion by modulating matrix metalloproteases.

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Arosarena, Oneida A; Barr, Eric W; Thorpe, Ryan; Yankey, Hilary; Tarr, Joseph T; Safadi, Fayez F

2018-01-01

Nearly 60% of patients with head and neck squamous cell carcinoma (HNSCC) die of metastases or locoregional recurrence. Metastasis is mediated by cancer cell migration and invasion, which are in part dependent on extracellular matrix degradation by matrix metalloproteinases. Osteoactivin (OA) overexpression plays a role in metastases in several malignancies, and has been shown to upregulate matrix metalloproteinase (MMP) expression and activity. To determine how OA modulates MMP expression and activity in HNSCC, and to investigate OA effects on cell invasion, we assessed effects of OA treatment on MMP mRNA and protein expression, as well as gelatinase and caseinolytic activity in HNSCC cell lines. We assessed the effects of OA gene silencing on MMP expression, gelatinase and caseinolytic activity, and cell invasion. OA treatment had differential effects on MMP mRNA expression. OA treatment upregulated MMP-10 expression in UMSCC14a (p = 0.0431) and SCC15 (p < 0.0001) cells, but decreased MMP-9 expression in UMSCC14a cells (p = 0.0002). OA gene silencing decreased MMP-10 expression in UMSCC12 cells (p = 0.0001), and MMP-3 (p = 0.0005) and -9 (p = 0.0036) expression in SCC25 cells. In SCC15 and SCC25 cells, OA treatment increased MMP-2 (p = 0.0408) and MMP-9 gelatinase activity (p < 0.0001), respectively. OA depletion decreased MMP-2 (p = 0.0023) and -9 (p < 0.0001) activity in SCC25 cells. OA treatment increased 70 kDa caseinolytic activity in UMSCC12 cells consistent with tissue type plasminogen activator (p = 0.0078). OA depletion decreased invasive capacity of UMSCC12 cells (p < 0.0001). OA's effects on MMP expression in HNSCC are variable, and may promote cancer cell invasion. © 2017 Wiley Periodicals, Inc.

Helicobacter pylori induces cell migration and invasion through casein kinase 2 in gastric epithelial cells.

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Lee, Yeo Song; Lee, Do Yeon; Yu, Da Yeon; Kim, Shin; Lee, Yong Chan

2014-12-01

Chronic infection with Helicobacter pylori (H. pylori) is causally linked with gastric carcinogenesis. Virulent H. pylori strains deliver bacterial CagA into gastric epithelial cells. Induction of high motility and an elongated phenotype is considered to be CagA-dependent process. Casein kinase 2 plays a critical role in carcinogenesis through signaling pathways related to the epithelial mesenchymal transition. This study was aimed to investigate the effect of H. pylori infection on the casein kinase 2-mediated migration and invasion in gastric epithelial cells. AGS or MKN28 cells as human gastric epithelial cells and H. pylori strains Hp60190 (ATCC 49503, CagA(+)) and Hp8822 (CagA(-)) were used. Cells were infected with H. pylori at multiplicity of infection of 100 : 1 for various times. We measured in vitro kinase assay to examine casein kinase 2 activity and performed immunofluorescent staining to observe E-cadherin complex. We also examined β-catenin transactivation through promoter assay and MMP7 expression by real-time PCR and ELISA. H. pylori upregulates casein kinase 2 activity and inhibition of casein kinase 2 in H. pylori-infected cells profoundly suppressed cell invasiveness and motility. We confirmed that casein kinase 2 mediates membranous α-catenin depletion through dissociation of the α-/β-catenin complex in H. pylori-infected cells. We also found that H. pylori induces β-catenin nuclear translocation and increases MMP7 expressions mediated through casein kinase 2. We show for the first time that CagA(+) H. pylori upregulates cellular invasiveness and motility through casein kinase 2. The demonstration of a mechanistic interplay between H. pylori and casein kinase 2 provides important insights into the role of CagA(+) H. pylori in the gastric cancer invasion and metastasis. © 2014 John Wiley & Sons Ltd.

Traversing the Cell: Agrobacterium T-DNA’s Journey to the Host Genome

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Gelvin, Stanton B.

2012-01-01

The genus Agrobacterium is unique in its ability to conduct interkingdom genetic exchange. Virulent Agrobacterium strains transfer single-strand forms of T-DNA (T-strands) and several Virulence effector proteins through a bacterial type IV secretion system into plant host cells. T-strands must traverse the plant wall and plasma membrane, traffic through the cytoplasm, enter the nucleus, and ultimately target host chromatin for stable integration. Because any DNA sequence placed between T-DNA “borders” can be transferred to plants and integrated into the plant genome, the transfer and intracellular trafficking processes must be mediated by bacterial and host proteins that form complexes with T-strands. This review summarizes current knowledge of proteins that interact with T-strands in the plant cell, and discusses several models of T-complex (T-strand and associated proteins) trafficking. A detailed understanding of how these macromolecular complexes enter the host cell and traverse the plant cytoplasm will require development of novel technologies to follow molecules from their bacterial site of synthesis into the plant cell, and how these transferred molecules interact with host proteins and sub-cellular structures within the host cytoplasm and nucleus. PMID:22645590

Invasive insect effects on nitrogen cycling and host physiology are not tightly linked.

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Rubino, Lucy; Charles, Sherley; Sirulnik, Abby G; Tuininga, Amy R; Lewis, James D

2015-02-01

Invasive insects may dramatically alter resource cycling and productivity in forest ecosystems. Yet, although responses of individual trees should both reflect and affect ecosystem-scale responses, relationships between physiological- and ecosystem-scale responses to invasive insects have not been extensively studied. To address this issue, we examined changes in soil nitrogen (N) cycling, N uptake and allocation, and needle biochemistry and physiology in eastern hemlock (Tsuga canadensis (L) Carr) saplings, associated with infestation by the hemlock woolly adelgid (HWA) (Adelges tsugae Annand), an invasive insect causing widespread decline of eastern hemlock in the eastern USA. Compared with uninfested saplings, infested saplings had soils that exhibited faster nitrification rates, and more needle (15)N uptake, N and total protein concentrations. However, these variables did not clearly covary. Further, within infested saplings, needle N concentration did not vary with HWA density. Light-saturated net photosynthetic rates (Asat) declined by 42% as HWA density increased from 0 to 3 adelgids per needle, but did not vary with needle N concentration. Rather, Asat varied with stomatal conductance, which was highest at the lowest HWA density and accounted for 79% of the variation in Asat. Photosynthetic light response did not differ among HWA densities. Our results suggest that the effects of HWA infestation on soil N pools and fluxes, (15)N uptake, needle N and protein concentrations, and needle physiology may not be tightly coupled under at least some conditions. This pattern may reflect direct effects of the HWA on N uptake by host trees, as well as effects of other scale-dependent factors, such as tree hydrology, affected by HWA activity. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Protein kinase Cδ signaling downstream of the EGF receptor mediates migration and invasiveness of prostate cancer cells

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Kharait, Sourabh; Dhir, Rajiv; Lauffenburger, Douglas; Wells, Alan

2006-01-01

Tumor progression to the invasive phenotype occurs secondary to upregulated signaling from growth factor receptors that drive key cellular responses like proliferation, migration, and invasion. We hypothesized that Protein kinase Cδ (PKCδ)-mediated transcellular contractility is required for migration and invasion of prostate tumor cells. Two invasive human prostate cancer cell lines, DU145 cells overexpressing wildtype human EGFR (DU145WT) and PC3 cells, were studied. PKCδ is overexpressed in these cells relative to normal prostate epithelial cells, and is activated downstream of EGFR leading to cell motility via modulation of myosin light chain activity. Abrogation of PKCδ using Rottlerin and specific siRNA significantly decreased migration and invasion of both cell lines in vitro. Both PKCδ and phosphorylated PKCδ protein levels were higher in human prostate cancer tissue relative to normal donor prostate as assessed by Western blotting and immunohistochemistry. Thus, we conclude that PKCδ inhibition can limit migration and invasion of prostate cancer cells

Effects of Src on Proliferation and Invasion of Lung Cancer Cells

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Rui ZHENG

2011-04-01

Full Text Available Background and objective It has been proven that Src played pivotal roles in carcinogenesis, cancer progression and metastasis. The aim of this study is to explore the roles of Src phosphorylation on lung cancer cells. Methods Western blot and immunoprecipitation was used to detect the expression and phosphorylation of Src in lung cancer cells. MTT and Boyden chamber assay was used to examine the effects of inhibition of Src phosphorylation on proliferation and invasion of lung cancer cells in vitro, respectively. Results pp60src was expressed in all lung cancer cell lines in this study. All 5 non-small cell lung cancer (NSCLC cell lines had increased autophosphorylated tyrosine-418, while nearly no phosphorylated Src in small cell lung cancer SBC5 cell line was detected. The effect of inhibition of Src tyrosine kinase on cell proliferation varied among the lung cancer cell lines. Submicromolar Src tyrosine kinase inhibitor (≤1 μM remarkably suppressed the proliferation of PC-9 and A549 cells in a dose dependent manner (P < 0.05, while the same concentration of Src tyrosine kinase inhibitor had no significant effect on proliferation of H226, PC14PE6 and RERFLCOK cells. Invasiveness of lung cancer cells was significantly suppressed by Src tyrosine kinase in a dose-dependent manner (P < 0.05. Conclusion Phosphorylation of Src, but not over-expression, plays a pivotal role in proliferation and invasion of NSCLC cell lines in vitro.

Pneumococci in biofilms are non-invasive: implications on nasopharyngeal colonization

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Ryan Paul Gilley

2014-11-01

Full Text Available Streptococcus pneumoniae (the pneumococcus is an opportunistic pathogen that colonizes the human nasopharynx asymptomatically. Invasive pneumococcal disease develops following bacterial aspiration into the lungs. Pneumococci within the nasopharynx exist as biofilms, a growth phenotype characterized by surface attachment, encasement within an extracellular matrix, and antimicrobial resistance. Experimental evidence indicates that biofilm pneumococci are attenuated versus their planktonic counterpart. Biofilm pneumococci failed to cause invasive disease in experimentally challenged mice and in vitro were shown to be non-invasive despite being hyper-adhesive. This attenuated phenotype corresponds with observations that biofilm pneumococci elicit significantly less cytokine and chemokine production from host cells than their planktonic counterparts. Microarray and proteomic studies show that pneumococci within biofilms have decreased metabolism, less capsular polysaccharide, and reduced production of the pore-forming toxin pneumolysin. Biofilm pneumococci are predominately in the transparent phenotype, which has elevated cell wall phosphorylcholine, an adhesin subject to C-reactive protein mediated opsonization. Herein, we review these changes in virulence, interpret their impact on colonization and transmission, and discuss the notion that non-invasive biofilms are principal lifestyle of S. pneumoniae.

Pertussis Toxin Exploits Host Cell Signaling Pathways Induced by Meningitis-Causing E. coli K1-RS218 and Enhances Adherence of Monocytic THP-1 Cells to Human Cerebral Endothelial Cells

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Laura Julia Starost

2016-10-01

Full Text Available Pertussis toxin (PTx, the major virulence factor of the whooping cough-causing bacterial pathogen Bordetella pertussis, permeabilizes the blood–brain barrier (BBB in vitro and in vivo. Breaking barriers might promote translocation of meningitis-causing bacteria across the BBB, thereby facilitating infection. PTx activates several host cell signaling pathways exploited by the neonatal meningitis-causing Escherichia coli K1-RS218 for invasion and translocation across the BBB. Here, we investigated whether PTx and E. coli K1-RS218 exert similar effects on MAPK p38, NF-κB activation and transcription of downstream targets in human cerebral endothelial TY10 cells using qRT-PCR, Western blotting, and ELISA in combination with specific inhibitors. PTx and E. coli K1-RS218 activate MAPK p38, but only E. coli K1-RS218 activates the NF-κB pathway. mRNA and protein levels of p38 and NF-κB downstream targets including IL-6, IL-8, CxCL-1, CxCL-2 and ICAM-1 were increased. The p38 specific inhibitor SB203590 blocked PTx-enhanced activity, whereas E. coli K1-RS218’s effects were inhibited by the NF-κB inhibitor Bay 11-7082. Further, we found that PTx enhances the adherence of human monocytic THP-1 cells to human cerebral endothelial TY10 cells, thereby contributing to enhanced translocation. These modulations of host cell signaling pathways by PTx and meningitis-causing E. coli support their contributions to pathogen and monocytic THP-1 cells translocation across the BBB.

Downregulation of Connective Tissue Growth Factor by Three-Dimensional Matrix Enhances Ovarian Carcinoma Cell Invasion

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Barbolina, Maria V.; Adley, Brian P.; Kelly, David L.; Shepard, Jaclyn; Fought, Angela J.; Scholtens, Denise; Penzes, Peter; Shea, Lonnie D.; Sharon Stack, M

2010-01-01

Epithelial ovarian carcinoma (EOC) is a leading cause of death from gynecologic malignancy, due mainly to the prevalence of undetected metastatic disease. The process of cell invasion during intra-peritoneal anchoring of metastatic lesions requires concerted regulation of many processes, including modulation of adhesion to the extracellular matrix and localized invasion. Exploratory cDNA microarray analysis of early response genes (altered after 4 hours of 3-dimensional collagen culture) coupled with confirmatory real-time RT-PCR, multiple three-dimensional cell culture matrices, Western blot, immunostaining, adhesion, migration, and invasion assays were used to identify modulators of adhesion pertinent to EOC progression and metastasis. cDNA microarray analysis indicated a dramatic downregulation of connective tissue growth factor (CTGF) in EOC cells placed in invasion-mimicking conditions (3-dimensional type I collagen). Examination of human EOC specimens revealed that CTGF expression was absent in 46% of the tested samples (n=41), but was present in 100% of normal ovarian epithelium samples (n=7). Reduced CTGF expression occurs in many types of cells and may be a general phenomenon displayed by cells encountering a 3D environment. CTGF levels were inversely correlated with invasion such that downregulation of CTGF increased, while its upregulation reduced, collagen invasion. Cells adhered preferentially to a surface comprised of both collagen I and CTGF relative to either component alone using α6β1 and α3β1 integrins. Together these data suggest that downregulation of CTGF in EOC cells may be important for cell invasion through modulation of cell-matrix adhesion. PMID:19382180

Adaptive Potential for the Invasion of Novel Host Plants in the Bean Weevil: Patterns of the Reproductive Behavior in Populations That Used Different Host Plants

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Dragana Milanović

2007-01-01

Full Text Available The goal of this work was to examine interpopulation patterns in the reproductive behavior of populations of bean weevil (Acanthoscelides obtectus Say; Coleoptera: Bruchidae that had different levels of specialization on their native host plant – the bean (Phaseolus vulgaris L., as well as on a novel host plant – the chickpea (Cicer arietinum Thorn. The obtained pattern of interpopulation mating behavior seemed exactly as if the males on chickpea had evolved a specific odor and/or a courtship ritual that females of populationson bean found repulsive. Unlike females, the males of bean populations seemed to be willing to mate with females from the population on chickpea equally as with their own females. Such an asymmetric pattern of reproductive isolation between populations ofa species has been often considered an initial phase of a process of speciation. Thus, our results could be a good starting point for further, thorough examination of both the role of the level of host specialization in females and the role of biochemical characteristics of male pheromone (and/or their cuticular hydrocarbones in the evolution of pre-reproductive isolation between insect populations.As the results of this study, together those of previous studies on A. obtectus, suggest great evolutionary potential for invasions of and fast specialization on novel host plants, they could provide valuable information for the development of long-term strategiesunder the programmes of Integrated Pest Management.

Functional characterization of E- and P-cadherin in invasive breast cancer cells

International Nuclear Information System (INIS)

Sarrió, David; Palacios, José; Hergueta-Redondo, Marta; Gómez-López, Gonzalo; Cano, Amparo; Moreno-Bueno, Gema

2009-01-01

Alterations in the cadherin-catenin adhesion complexes are involved in tumor initiation, progression and metastasis. However, the functional implication of distinct cadherin types in breast cancer biology is still poorly understood. To compare the functional role of E-cadherin and P-cadherin in invasive breast cancer, we stably transfected these molecules into the MDA-MB-231 cell line, and investigated their effects on motility, invasion and gene expression regulation. Expression of either E- and P-cadherin significantly increased cell aggregation and induced a switch from fibroblastic to epithelial morphology. Although expression of these cadherins did not completely reverse the mesenchymal phenotype of MDA-MB-231 cells, both E- and P-cadherin decreased fibroblast-like migration and invasion through extracellular matrix in a similar way. Moreover, microarray gene expression analysis of MDA-MB-231 cells after expression of E- and P-cadherins revealed that these molecules can activate signaling pathways leading to significant changes in gene expression. Although the expression patterns induced by E- and P-cadherin showed more similarities than differences, 40 genes were differentially modified by the expression of either cadherin type. E- and P-cadherin have similar functional consequences on the phenotype and invasive behavior of MDA-MB-231 cells. Moreover, we demonstrate for the first time that these cadherins can induce both common and specific gene expression programs on invasive breast cancer cells. Importantly, these identified genes are potential targets for future studies on the functional consequences of altered cadherin expression in human breast cancer

Functional characterization of E- and P-cadherin in invasive breast cancer cells

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Cano Amparo

2009-03-01

Full Text Available Abstract Background Alterations in the cadherin-catenin adhesion complexes are involved in tumor initiation, progression and metastasis. However, the functional implication of distinct cadherin types in breast cancer biology is still poorly understood. Methods To compare the functional role of E-cadherin and P-cadherin in invasive breast cancer, we stably transfected these molecules into the MDA-MB-231 cell line, and investigated their effects on motility, invasion and gene expression regulation. Results Expression of either E- and P-cadherin significantly increased cell aggregation and induced a switch from fibroblastic to epithelial morphology. Although expression of these cadherins did not completely reverse the mesenchymal phenotype of MDA-MB-231 cells, both E- and P-cadherin decreased fibroblast-like migration and invasion through extracellular matrix in a similar way. Moreover, microarray gene expression analysis of MDA-MB-231 cells after expression of E- and P-cadherins revealed that these molecules can activate signaling pathways leading to significant changes in gene expression. Although the expression patterns induced by E- and P-cadherin showed more similarities than differences, 40 genes were differentially modified by the expression of either cadherin type. Conclusion E- and P-cadherin have similar functional consequences on the phenotype and invasive behavior of MDA-MB-231 cells. Moreover, we demonstrate for the first time that these cadherins can induce both common and specific gene expression programs on invasive breast cancer cells. Importantly, these identified genes are potential targets for future studies on the functional consequences of altered cadherin expression in human breast cancer.

Host defence against disseminated and invasive candida albicans infections.

NARCIS (Netherlands)

Vonk, A.G.

2004-01-01

The yeast Candida albicans is the primary etiologic agent of disseminated and invasive candidiasis. The incidence of disseminated and invasive candidiasis has paralleled the use of modern medical procedures that adversely affect the immune system, and highlights the difficulty of treating

Anti-invasive and antiangiogenic effects of MMI-166 on malignant glioma cells

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Nakabayashi, Hiromichi; Yawata, Toshio; Shimizu, Keiji

2010-01-01

The constitutive overexpression of matrix metalloproteinases (MMPs) is frequently observed in malignant tumours. In particular, MMP-2 and MMP-9 have been reported to be closely associated with invasion and angiogenesis in malignant gliomas. Our study aimed to evaluate the antitumour effects of MMI-166 (Nalpha-[4-(2-Phenyl-2H- tetrazole-5-yl) phenyl sulfonyl]-D-tryptophan), a third generation MMP inhibitor, on three human glioma cell lines (T98G, U87MG, and ONS12) in vitro and in vivo. The effects of MMI-166 on the gelatinolytic activity was analysed by gelatine zymography. The anti-invasive effect of MMI-166 was analysed by an in vitro invasion assay. An in vitro angiogenesis assay was also performed. In vitro growth inhibition of glioma cells by MMI-166 was determined by the MTT assay. The effect of MMI-166 on an orthotropic implantation model using athymic mice was also evaluated. Gelatine zymography revealed that MMP-2 and MMP-9 activities were suppressed by MMI-166. The invasion of glioma cells was suppressed by MMI-166. The angiogenesis assay showed that MMI-166 had a suppressive effect on glioma cell-induced angiogenesis. However, MMI-166 did not suppress glioma cell proliferation in the MTT assay. In vivo, MMI-166 suppressed tumour growth in athymic mice implanted orthotropically with T98G cells and showed an inhibitory effect on tumour-induced angiogenesis and tumour growth. This is the first report of the effect of a third generation MMP inhibitor on malignant glioma cells. These results suggest that MMI-166 may have potentially suppressive effects on the invasion and angiogenesis of malignant gliomas

Pathogenesis of invasive candidiasis.

NARCIS (Netherlands)

Veerdonk, F.L. van de; Kullberg, B.J.; Netea, M.G.

2010-01-01

PURPOSE OF REVIEW: Disseminated candidiasis remains a life-threatening disease in the ICU. The development of invasive disease with Candida albicans is dependent on multiple factors, such as colonization and efficient host defense at the mucosa. In the present review, we describe the host defense

PBX3 promotes migration and invasion of colorectal cancer cells via activation of MAPK/ERK signaling pathway.

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Han, Hai-Bo; Gu, Jin; Ji, Deng-Bo; Li, Zhao-Wei; Zhang, Yuan; Zhao, Wei; Wang, Li-Min; Zhang, Zhi-Qian

2014-12-28

To investigate the role of pre-B-cell leukemia homeobox (PBX)3 in migration and invasion of colorectal cancer (CRC) cells. We detected PBX3 expression in five cell lines and surgical specimens from 111 patients with CRC using real-time reverse transcription-polymerase chain reaction. We forced expression of PBX3 in low metastatic HT-29 and SW480 cells and knocked down expression of PBX3 in highly metastatic LOVO and HCT-8 cells. Wound healing and Boyden chamber assays were used to detect cell migration and invasion after altered expression of PBX3. Western blot was performed to detect the change of signaling molecule ERK1/2 following PBX3 overexpression. High level of PBX3 expression was correlated with the invasive potential of CRC cells, and significantly associated with lymph node invasion (P = 0.02), distant metastasis (P = 0.04), advanced TNM stage (P = 0.03) and poor overall survival of patients (P migration and invasion, while inhibited PBX3 expression in highly metastatic cells suppressed migration and invasion. Furthermore, upregulation of phosphorylated extracellular signal-regulated kinase (ERK)1/2 was found to be one of the targeted molecules responsible for PBX3-induced CRC cell migration and invasion. PBX3 induces invasion and metastasis of CRC cells partially through activation of the MAPK/ERK signaling pathway.

Loss of RUNX3 expression inhibits bone invasion of oral squamous cell carcinoma.

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Park, Junhee; Kim, Hyun-Jeong; Kim, Ki Rim; Lee, Sun Kyoung; Kim, Hyungkeun; Park, Kwang-Kyun; Chung, Won-Yoon

2017-02-07

High recurrence and lower survival rates in patients with oral squamous cell carcinoma (OSCC) are associated with its bone invasion. We identified the oncogenic role of RUNX3 during bone invasion by OSCC. Tumor growth and the generation of osteolytic lesions were significantly inhibited in mice that were subcutaneously inoculated with RUNX3-knockdown human OSCC cells. RUNX3 knockdown enhanced TGF-β-induced growth arrest and inhibited OSCC cell migration and invasion in the absence or presence of transforming growth factor-β (TGF-β), a major growth factor abundant in the bone microenvironment. RUNX3 knockdown induced cell cycle arrest at the G1 and G2 phases and promoted G2 arrest by TGF-β in Ca9.22 OSCC cells. RUNX3 knockdown also inhibited both the basal and TGF-β-induced epithelial-to-mesenchymal transition by increasing E-cadherin expression and suppressing the nuclear translocation of β-catenin. In addition, the expression and TGF-β-mediated induction of parathyroid hormone-related protein (PTHrP), one of key osteolytic factors, was blocked in RUNX3-knockdown OSCC cells. Furthermore, treating human osteoblastic cells with conditioned medium derived from RUNX3-knockdown OSCC cells reduced the receptor activator of nuclear factor-kappaB ligand (RANKL)/osteoprotegerin ratio compared with treatment with conditioned medium from RUNX3-expressing cells. These findings indicate that RUNX3 expression in OSCC cells contributes to their bone invasion and the resulting osteolysis by inducing their malignant behaviors and production of osteolytic factors. RUNX3 alone or in combination with TGF-β and PTHrP may be a useful predictive biomarker and therapeutic target for bone invasion by oral cancer.

Mesenchymal stromal cells in the antimicrobial host response of hematopoietic stem cell recipients with graft-versus-host disease--friends or foes?

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Balan, A; Lucchini, G; Schmidt, S; Schneider, A; Tramsen, L; Kuçi, S; Meisel, R; Bader, P; Lehrnbecher, T

2014-10-01

Mesenchymal stromal cells (MSCs) are multipotent cells, which exhibit broad immunosuppressive activities. Moreover, they may be administered irrespectively of human leukocyte antigen (HLA) compatibility, without inducing life-threatening immunological reactions, as they express no HLA class II and limited HLA class I antigens under resting conditions. These characteristics have made MSC an appealing candidate for cell therapy after hematopoietic stem cell transplantation (HSCT), for example, for treatment of graft-versus-host disease (GvHD) or for graft rejection prevention/treatment in allogeneic HSCT recipients. Unfortunately, information regarding the effect of MSC infusion on the host response to infectious agents is scarce, and study results on infectious complications in patients receiving MSC are conflicting. The present review focuses on the available data from in vitro studies and animal models regarding the interaction of MSC with bacterial, viral and fungal pathogens. In a clinical part, we present the current information on infectious complications in allogeneic HSCT recipients who had received MSCs as prophylaxis or treatment of GvHD disease.

Calorie restriction as an anti-invasive therapy for malignant brain cancer in the VM mouse.

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Shelton, Laura M; Huysentruyt, Leanne C; Mukherjee, Purna; Seyfried, Thomas N

2010-07-23

GBM (glioblastoma multiforme) is the most aggressive and invasive form of primary human brain cancer. We recently developed a novel brain cancer model in the inbred VM mouse strain that shares several characteristics with human GBM. Using bioluminescence imaging, we tested the efficacy of CR (calorie restriction) for its ability to reduce tumour size and invasion. CR targets glycolysis and rapid tumour cell growth in part by lowering circulating glucose levels. The VM-M3 tumour cells were implanted intracerebrally in the syngeneic VM mouse host. Approx. 12-15 days post-implantation, brains were removed and both ipsilateral and contralateral hemispheres were imaged to measure bioluminescence of invading tumour cells. CR significantly reduced the invasion of tumour cells from the implanted ipsilateral hemisphere into the contralateral hemisphere. The total percentage of Ki-67-stained cells within the primary tumour and the total number of blood vessels was also significantly lower in the CR-treated mice than in the mice fed ad libitum, suggesting that CR is anti-proliferative and anti-angiogenic. Our findings indicate that the VM-M3 GBM model is a valuable tool for studying brain tumour cell invasion and for evaluating potential therapeutic approaches for managing invasive brain cancer. In addition, we show that CR can be effective in reducing malignant brain tumour growth and invasion.

Calorie Restriction as an Anti-Invasive Therapy for Malignant Brain Cancer in the VM Mouse

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Laura M Shelton

2010-07-01

Full Text Available GBM (glioblastoma multiforme is the most aggressive and invasive form of primary human brain cancer. We recently developed a novel brain cancer model in the inbred VM mouse strain that shares several characteristics with human GBM. Using bioluminescence imaging, we tested the efficacy of CR (calorie restriction for its ability to reduce tumour size and invasion. CR targets glycolysis and rapid tumour cell growth in part by lowering circulating glucose levels. The VM-M3 tumour cells were implanted intracerebrally in the syngeneic VM mouse host. Approx. 12-15 days post-implantation, brains were removed and both ipsilateral and contralateral hemispheres were imaged to measure bioluminescence of invading tumour cells. CR significantly reduced the invasion of tumour cells from the implanted ipsilateral hemisphere into the contralateral hemisphere. The total percentage of Ki-67-stained cells within the primary tumour and the total number of blood vessels was also significantly lower in the CR-treated mice than in the mice fed ad libitum, suggesting that CR is anti-proliferative and anti-angiogenic. Our findings indicate that the VM-M3 GBM model is a valuable tool for studying brain tumour cell invasion and for evaluating potential therapeutic approaches for managing invasive brain cancer. In addition, we show that CR can be effective in reducing malignant brain tumour growth and invasion.

The apical complex provides a regulated gateway for secretion of invasion factors in Toxoplasma.

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Nicholas J Katris

2014-04-01

Full Text Available The apical complex is the definitive cell structure of phylum Apicomplexa, and is the focus of the events of host cell penetration and the establishment of intracellular parasitism. Despite the importance of this structure, its molecular composition is relatively poorly known and few studies have experimentally tested its functions. We have characterized a novel Toxoplasma gondii protein, RNG2, that is located at the apical polar ring--the common structural element of apical complexes. During cell division, RNG2 is first recruited to centrosomes immediately after their duplication, confirming that assembly of the new apical complex commences as one of the earliest events of cell replication. RNG2 subsequently forms a ring, with the carboxy- and amino-termini anchored to the apical polar ring and mobile conoid, respectively, linking these two structures. Super-resolution microscopy resolves these two termini, and reveals that RNG2 orientation flips during invasion when the conoid is extruded. Inducible knockdown of RNG2 strongly inhibits host cell invasion. Consistent with this, secretion of micronemes is prevented in the absence of RNG2. This block, however, can be fully or partially overcome by exogenous stimulation of calcium or cGMP signaling pathways, respectively, implicating the apical complex directly in these signaling events. RNG2 demonstrates for the first time a role for the apical complex in controlling secretion of invasion factors in this important group of parasites.

HumanViCe: Host ceRNA network in virus infected cells in human

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Suman eGhosal

2014-07-01

Full Text Available Host-virus interaction via host cellular components has been an important field of research in recent times. RNA interference mediated by short interfering RNAs and microRNAs (miRNA, is a widespread anti-viral defence strategy. Importantly, viruses also encode their own miRNAs. In recent times miRNAs were identified as key players in host-virus interaction. Furthermore, viruses were shown to exploit the host miRNA networks to suite their own need. The complex cross-talk between host and viral miRNAs and their cellular and viral targets forms the environment for viral pathogenesis. Apart from protein-coding mRNAs, non-coding RNAs may also be targeted by host or viral miRNAs in virus infected cells, and viruses can exploit the host miRNA mediated gene regulatory network via the competing endogenous RNA effect. A recent report showed that viral U-rich non-coding RNAs called HSUR, expressed in primate virus herpesvirus saimiri (HVS infected T cells, were able to bind to three host miRNAs, causing significant alteration in cellular level for one of the miRNAs. We have predicted protein coding and non protein-coding targets for viral and human miRNAs in virus infected cells. We identified viral miRNA targets within host non-coding RNA loci from AGO interacting regions in three different virus infected cells. Gene ontology (GO and pathway enrichment analysis of the genes comprising the ceRNA networks in the virus infected cells revealed enrichment of key cellular signalling pathways related to cell fate decisions and gene transcription, like Notch and Wnt signalling pathways, as well as pathways related to viral entry, replication and virulence. We identified a vast number of non-coding transcripts playing as potential ceRNAs to the immune response associated genes; e.g. APOBEC family genes, in some virus infected cells. All these information are compiled in HumanViCe, a comprehensive database that provides the potential ceRNA networks in virus

Modeling conduction in host-graft interactions between stem cell grafts and cardiomyocytes.

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Chen, Michael Q; Yu, Jin; Whittington, R Hollis; Wu, Joseph C; Kovacs, Gregory T A; Giovangrandi, Laurent

2009-01-01

Cell therapy has recently made great strides towards aiding heart failure. However, while transplanted cells may electromechanically integrate into host tissue, there may not be a uniform propagation of a depolarization wave between the heterogeneous tissue boundaries. A model using microelectrode array technology that maps the electrical interactions between host and graft tissues in co-culture is presented and sheds light on the effects of having a mismatch of conduction properties at the boundary. Skeletal myoblasts co-cultured with cardiomyocytes demonstrated that conduction velocity significantly decreases at the boundary despite electromechanical coupling. In an attempt to improve the uniformity of conduction with host cells, differentiating human embryonic stem cells (hESC) were used in co-culture. Over the course of four to seven days, synchronous electrical activity was observed at the hESC boundary, implying differentiation and integration. Activity did not extend far past the boundary, and conduction velocity was significantly greater than that of the host tissue, implying the need for other external measures to properly match the conduction properties between host and graft tissue.

Proliferative and Invasive Effects of Progesterone-Induced Blocking Factor in Human Glioblastoma Cells

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Araceli Gutiérrez-Rodríguez

2017-01-01

Full Text Available Progesterone-induced blocking factor (PIBF is a progesterone (P4 regulated protein expressed in different types of high proliferative cells including astrocytomas, the most frequent and aggressive brain tumors. It has been shown that PIBF increases the number of human astrocytoma cells. In this work, we evaluated PIBF regulation by P4 and the effects of PIBF on proliferation, migration, and invasion of U87 and U251 cells, both derived from human glioblastomas. PIBF mRNA expression was upregulated by P4 (10 nM from 12 to 24 h. Glioblastoma cells expressed two PIBF isoforms, 90 and 57 kDa. The content of the shorter isoform was increased by P4 at 24 h, while progesterone receptor antagonist RU486 (10 μM blocked this effect. PIBF (100 ng/mL increased the number of U87 cells on days 4 and 5 of treatment and induced cell proliferation on day 4. Wound-healing assays showed that PIBF increased the migration of U87 (12–48 h and U251 (24 and 48 h cells. Transwell invasion assays showed that PIBF augmented the number of invasive cells in both cell lines at 24 h. These data suggest that PIBF promotes proliferation, migration, and invasion of human glioblastoma cells.

Plant parasitic nematode effectors target host defence and nuclear functions to establish feeding cells

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Michaël eQuentin

2013-03-01

Full Text Available Plant parasitic nematodes are microscopic worms, the most damaging species of which have adopted a sedentary lifestyle within their hosts. These obligate endoparasites have a biotrophic relationship with plants, in which they induce the differentiation of root cells into hypertrophied, multinucleate feeding cells. Effectors synthesised in the oesophageal glands of the nematode are injected into the plant cells via the syringe-like stylet and play a key role in manipulating the host machinery. The establishment of specialized feeding cells requires these effectors to modulate many aspects of plant cell morphogenesis and physiology, including defence responses. This cell reprogramming requires changes to host nuclear processes. Some proteins encoded by parasitism genes target host nuclei. Several of these proteins were immunolocalised within feeding cell nuclei or shown to interact with host nuclear proteins. Comparative genomics and functional analyses are gradually revealing the roles of nematode effectors. We describe here these effectors and their hypothesised roles in the unique feeding behaviour of these pests.

The impact of parasites during range expansion of an invasive gecko.

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Barnett, Louise K; Phillips, Ben L; Heath, Allen C G; Coates, Andrew; Hoskin, Conrad J

2018-02-14

Host-parasite dynamics can play a fundamental role in both the establishment success of invasive species and their impact on native wildlife. The net impact of parasites depends on their capacity to switch effectively between native and invasive hosts. Here we explore host-switching, spatial patterns and simple fitness measures in a slow-expanding invasion: the invasion of Asian house geckos (Hemidactylus frenatus) from urban areas into bushland in Northeast Australia. In bushland close to urban edges, H. frenatus co-occurs with, and at many sites now greatly out-numbers, native geckos. We measured prevalence and intensity of Geckobia mites (introduced with H. frenatus), and Waddycephalus (a native pentastome). We recorded a new invasive mite species, and several new host associations for native mites and geckos, but we found no evidence of mite transmission between native and invasive geckos. In contrast, native Waddycephalus nymphs were commonly present in H. frenatus, demonstrating this parasite's capacity to utilize H. frenatus as a novel host. Prevalence of mites on H. frenatus decreased with distance from the urban edge, suggesting parasite release towards the invasion front; however, we found no evidence that mites affect H. frenatus body condition or lifespan. Waddycephalus was present at low prevalence in bushland sites and, although its presence did not affect host body condition, our data suggest that it may reduce host survival. The high relative density of H. frenatus at our sites, and their capacity to harbour Waddycephalus, suggests that there may be impacts on native geckos and snakes through parasite spillback.

Tumor-Infiltrating Immune Cells Promoting Tumor Invasion and Metastasis: Existing Theories

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Yan-gao Man, Alexander Stojadinovic, Jeffrey Mason, Itzhak Avital, Anton Bilchik, Bjoern Bruecher, Mladjan Protic, Aviram Nissan, Mina Izadjoo, Xichen Zhang, Anahid Jewett

2013-01-01

Full Text Available It is a commonly held belief that infiltration of immune cells into tumor tissues and direct physical contact between tumor cells and infiltrated immune cells is associated with physical destructions of the tumor cells, reduction of the tumor burden, and improved clinical prognosis. An increasing number of studies, however, have suggested that aberrant infiltration of immune cells into tumor or normal tissues may promote tumor progression, invasion, and metastasis. Neither the primary reason for these contradictory observations, nor the mechanism for the reported diverse impact of tumor-infiltrating immune cells has been elucidated, making it difficult to judge the clinical implications of infiltration of immune cells within tumor tissues. This mini-review presents several existing hypotheses and models that favor the promoting impact of tumor-infiltrating immune cells on tumor invasion and metastasis, and also analyzes their strength and weakness.

Inhibition of host cell translation elongation by Legionella pneumophila blocks the host cell unfolded protein response.

Science.gov (United States)

Hempstead, Andrew D; Isberg, Ralph R

2015-12-08

Cells of the innate immune system recognize bacterial pathogens by detecting common microbial patterns as well as pathogen-specific activities. One system that responds to these stimuli is the IRE1 branch of the unfolded protein response (UPR), a sensor of endoplasmic reticulum (ER) stress. Activation of IRE1, in the context of Toll-like receptor (TLR) signaling, induces strong proinflammatory cytokine induction. We show here that Legionella pneumophila, an intravacuolar pathogen that replicates in an ER-associated compartment, blocks activation of the IRE1 pathway despite presenting pathogen products that stimulate this response. L. pneumophila TLR ligands induced the splicing of mRNA encoding XBP1s, the main target of IRE1 activity. L. pneumophila was able to inhibit both chemical and bacterial induction of XBP1 splicing via bacterial translocated proteins that interfere with host protein translation. A strain lacking five translocated translation elongation inhibitors was unable to block XBP1 splicing, but this could be rescued by expression of a single such inhibitor, consistent with limitation of the response by translation elongation inhibitors. Chemical inhibition of translation elongation blocked pattern recognition receptor-mediated XBP1 splicing, mimicking the effects of the bacterial translation inhibitors. In contrast, host cell-promoted inhibition of translation initiation in response to the pathogen was ineffective in blocking XBP1 splicing, demonstrating the need for the elongation inhibitors for protection from the UPR. The inhibition of host translation elongation may be a common strategy used by pathogens to limit the innate immune response by interfering with signaling via the UPR.

Invasion ecology meets parasitology: Advances and challenges

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Robert Poulin

2017-12-01

Full Text Available Biological invasions threaten the diversity and functioning of native ecosystems, and the rate at which species are being introduced to new areas shows no sign of slowing down. Parasites play roles in biological invasions, for instance when native parasites interact with exotic hosts, or when parasites themselves are introduced to new areas. However, publication trends show clearly that research on parasitism in the context of biological invasions is lagging far behind research on biological invasions in general. The different articles in this special issue of International Journal for Parasitology–Parasites and Wildlife on ‘Invasions’ address various aspects of the interface between parasitology and invasion biology, including how invasive free-living species lose or gain parasites on the invasion front as they move away from their site of introduction, how these invasive species affect the dynamics of native parasites, and how exotic parasites become established and impact native hosts. Together, they highlight the challenges facing researchers in this area, and set the agenda for the next few years of research. Keywords: alien species, Biological invasions, Enemy release, Non-natives, Parasites