• Journal of Microbiology and Biotechnology
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• v.28 no.1
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• pp.59-64
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• 2018

Listeria monocytogenes can asymptomatically inhabit the human intestine as a commensal bacterium. However, the mechanism by which L. monocytogenes is able to inhabit the intestine without pathogenic symptoms remains unclear. We compared the invasion efficiency of L. monocytogenes strains with the 268- and 385-bp-long actA gene. Clinical strains SMFM-CI-3 and SMFM-CI-6 with 268-bp actA isolated from patients with listeriosis, and strains SMFM-SI-1 and SMFM-SI-2 with the 385-bp gene isolated from carcasses, were used for inoculum preparation. The invasion efficiency of these strains was evaluated using Caco-2 cells (intestinal epithelial cell line), prepared as normal and healthy cells with tightened tight junctions and senescent cells with loose tight junctions that were loosened by adriamycin treatment. The invasion efficiency of L. monocytogenes strains with the 268-bp-long actA gene was 1.1-2.6-times lower than that of the strains with the 385-bp-long gene in normal and healthy cells. However, the invasion efficiency of both types of strains did not differ in senescent cells. Thus, L. monocytogenes strains with the 268-bp-long actA gene can inhabit the intestine asymptomatically as a commensal bacterium, but they may invade the intestinal epithelial cells and cause listeriosis in senescent cells.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.5
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• pp.391-396
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• 2014

Although interleukin-11 (IL-11) has been reported to be elevated in hypoxic tumors and has been associated with a poor prognosis in various cancers, little is known about its precise role in promoting metastasis in hypoxic tumors. In the present study, the molecular mechanism underlying the effects of IL-11 on MDA-MB-231 breast cancer cells migration and invasion in relation to metastasis under hypoxic conditions has been defined. Inhibition of IL-11 expression or function using small interfering RNA (siRNA) or a neutralizing antibody attenuated hypoxic MDA-MB-231 breast cancer cell migration and invasion through down-regulation of matrix metalloproteinases (MMPs) and activation of epithelial-to-mesenchymal transition (EMT) related gene expression. In addition, hypoxia-induced IL-11 increased STAT3 phosphorylation and STAT3 knockdown suppressed hypoxic MDA-MB-231 breast cancer cell invasion due to reduced MMP levels and reprogrammed EMT-related gene expression. These results suggest that one of the hypoxic metastasis pathways and the regulation of this pathway could be a potential target for novel cancer therapeutics.

• Journal of Veterinary Science
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• v.24 no.6
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• pp.82.1-82.12
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• 2023

Background: The current conventional serotyping based on antigen-antisera agglutination could not provide a better understanding of the potential pathogenicity of Salmonella enterica subsp. enterica serovar Brancaster. Surveillance data from Malaysian poultry farms indicated an increase in its presence over the years. Objective: This study aims to investigate the virulence determinants and antimicrobial resistance in S. Brancaster isolated from chickens in Malaysia. Methods: One hundred strains of archived S. Brancaster isolated from chicken cloacal swabs and raw chicken meat from 2017 to 2022 were studied. Two sets of multiplex polymerase chain reaction (PCR) were conducted to identify eight virulence genes associated with pathogenicity in Salmonella (invasion protein gene [invA], Salmonella invasion protein gene [sipB], Salmonella-induced filament gene [sifA], cytolethal-distending toxin B gene [cdtB], Salmonella iron transporter gene [sitC], Salmonella pathogenicity islands gene [spiA], Salmonella plasmid virulence gene [spvB], and inositol phosphate phosphatase gene [sopB]). Antimicrobial susceptibility assessment was conducted by disc diffusion method on nine selected antibiotics for the S. Brancaster isolates. S. Brancaster, with the phenotypic ACSSuT-resistance pattern (ampicillin, chloramphenicol, streptomycin, sulphonamides, and tetracycline), was subjected to PCR to detect the corresponding resistance gene(s). Results: Virulence genes detected in S. Brancaster in this study were invA, sitC, spiA, sipB, sopB, sifA, cdtB, and spvB. A total of 36 antibiogram patterns of S. Brancaster with a high level of multidrug resistance were observed, with ampicillin exhibiting the highest resistance. Over a third of the isolates displayed ACSSuT-resistance, and seven resistance genes (β-lactamase temoneira [bla_TEM], florfenicol/chloramphenicol resistance gene [floR], streptomycin resistance gene [strA], aminoglycoside nucleotidyltransferase gene [ant(3")-Ia], sulfonamides resistance gene [sul-1, sul-2], and tetracycline resistance gene [tetA]) were detected. Conclusion: Multidrug-resistant S. Brancaster from chickens harbored an array of virulence-associated genes similar to other clinically significant and invasive non-typhoidal Salmonella serovars, placing it as another significant foodborne zoonosis.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.9
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• pp.5391-5396
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• 2013

Aim: To investigate the role of Golgi phosphoprotein 3 (GOLPH3) in tumour growth and metastasis of esophageal squamous cancer. Methods: A lentiviral shRNA-vector was utilized to stably knockdown GOLPH3 in Eca-109 esophageal squamous cancer cells. mRNA transcription and protein expression of GOLPH3 were examined by real-time quantitative PCR and Western blotting, respectively. Cell proliferation activity was assessed by MTT assay and invasion and migration potentials by matrigel invasion and transwell motility assays. Results: Stable knockdown in the GOLPH3 cell line was established. PD-A gene expression was significantly suppressed by lentivirus-mediated RNAi, which resulted in reducing the capacity for cell proliferation, migration, invasion and adhesion in vitro. In vivo, GOLPH3 depletion resulted in inhibition of tumour growth, with stable decrease in the expression of GOLPH3 in tumor xenografts. Conclusions: Our findings suggest that lentivirus mediated silencing of the GOLPH3 gene has a significant anti-tumour effect on esophageal squamous cancer in vitro and in vivo. In addition, the results indicate that GOLPH3 might be an effective molecular target for gene therapy in esophageal squamous cancer.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.200-200
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• 2001

The matrix metalloproteases (MMPs) play important roles in metastasis and invasion in various cell types. An endogenous inhibitor of MMP, tissue inhibitor of metalloprotease-2 (TIMP-2), has high specificity for MMP-2. An imbalance between MMP-2 and TIMP-2 causes the degradation of the extracellular matrix associated with pathological events including invasion and metastasis. Since TIMPs are secreted molecules, they have the potential to be used for gene therapy of certain tumors. (omitted)

• Biomolecules & Therapeutics
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• v.20 no.3
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• pp.286-292
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• 2012

All-trans retinoic acid (ATRA) is currently used in adjuvant differentiation-based treatment of residual or relapsed neuroblastoma (NB). It has been reported that short-term ATRA treatment induces migration and invasion of SH-SY5Y via transglutaminase-2 (Tgase-2). However, the detailed mechanism of Tgase-2's involvement in NB cell invasion remains unclear. Therefore we investigated the role of Tgase-2 in invasion of NB cells using SH-SY5Y cells. ATRA dose-dependently induced the invasion of SH-SY5Y cells. Cystamine (CTM), a well known tgase inhibitor suppressed the ATRA-induced invasion of SH-SY5Y cells in a dose-dependent manner. Matrix metalloproteinase -9 (MMP-9) and MMP-2, well known genes involved in invasion of cancer cells were induced in the ATRA-induced invasion of the SH-SH5Y cells. Treatment of CTM suppressed the MMP-9 and MMP-2 enzyme activities in the ATRA-induced invasion of the SH-SY5Y cells. To confirm the involvement of Tgase-2, gene silencing of Tgase-2 was performed in the ATRA-induced invasion of the SH-SH5Y cells. The siRNA of Tgase-2 suppressed the MMP-9 and MMP-2 activity of the SH-SY5Y cells. MMP-2 and MMP-9 are well known target genes of NF-${\kappa}B$. Therefore the relationship of Tgase-2 and NF-${\kappa}B$ in the ATRA-induced invasion of the SH-SY5Y cells was examined using siRNA and CTM. ATRA induced the activation of NF-${\kappa}B$ in the SH-SY5Y cells and CTM suppressed the activation of NF-${\kappa}B$. Gene silencing of Tgase-2 suppressed the MMP expression by ATRA. These results suggested that Tgase-2 might be a new target for controlling the ATRA-induced invasion of NBs.

• Molecules and Cells
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• v.40 no.10
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• pp.761-772
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• 2017

Glioblastoma is the most frequent and most aggressive brain tumor in adults. Solute carrier family 8 member 2 (SLC8A2) is only expressed in normal brain, but not present in other human normal tissues or in gliomas. Therefore, we hypothesized that SLC8A2 might be a glioma tumor suppressor gene and detected the role of SLC8A2 in glioblastoma and explored the underlying molecular mechanism. The glioblastoma U87MG cells stably transfected with the lentivirus plasmid containg SLC8A2 (U87MG-SLC8A2) and negative control (U87MG-NC) were constructed. In the present study, we found that the tumorigenicity of U87MG in nude mice was totally inhibited by SLC8A2. Overexpression of SLC8A2 had no effect on cell proliferation or cell cycle, but impaired the invasion and migration of U87MG cells, most likely through inactivating the extracellular signal-related kinases (ERK)1/2 signaling pathway, inhibiting the nuclear translocation and DNA binding activity of nuclear factor kappa B ($NF-{\kappa}B$), reducing the level of matrix metalloproteinases (MMPs) and urokinase-type plasminogen activator (uPA)-its receptor (uPAR) system (ERK1/2-$NF-{\kappa}B$-MMPs/uPA-uPAR), and altering the protein levels of epithelial to mesenchymal transitions (EMT)-associated proteins E-cardherin, vimentin and Snail. In addition, SLC8A2 inhibited the angiogenesis of U87MG cells, probably through combined inhibition of endothelium-dependent and endothelium-nondependent angiogenesis (vascular mimicry pattern). Totally, SLC8A2 serves as a tumor suppressor gene and inhibits invasion, angiogenesis and growth of glioblastoma.

• Clinical and Experimental Reproductive Medicine
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• v.40 no.1
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• pp.12-22
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• 2013

Objective: We investigated the norepinephrine transporter (NET) expression in normal and pre-eclamptic placentas and analyzed the invasion activity of trophoblastic cells based on norepinephrine (NE)-NET regulation. Methods: NET and NE expression levels were examined by western blot and enzyme-linked immunosorbent assay, respectively. Trophoblast invasion activity, depending on NE-NET regulation, was determined by NET-small interfering RNA (siRNA) and NET transfection into the human extravillous trophoblast cells with or without NE treatment and invasion rates were analyzed by zymography and an invasion assay. Results: NET mRNA was expressed at a low level in pre-eclamptic placentas compared with normal placentas and NE concentration in maternal plasma increased significantly in pre-eclamptic women compared to normal pregnant women (p<0.05). NET gene upregulation and NE treatment stimulated trophoblast cell invasion up to 2.5-fold (p<0.05) by stimulating matrix metalloproteinase-9 activity via the phosphoinositol-3-kinase/AKT signaling pathway, whereas NET-siRNA with NE treatment reduced invasion rates. Conclusion: NET expression is reduced by inadequate regulation of NE levels during placental development. This suggests that a complementary balance between NET and NE regulates trophoblast cell invasion activities during placental development.

• Journal of Microbiology
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• v.43 no.spc1
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• pp.110-117
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• 2005

Salmonella enterica serovar Typhimurium causes human gastroenteritis and a systemic typhoid-like infection in mice. A critical virulence determinant of Salmonella is the ability to invade mammalian cells. The expression of genes required for invasion is tightly regulated by environmental conditions and a variety of regulatory genes. The hilA regulator encodes an OmpR/ToxR family transcriptional regulator that activates the expression of invasion genes in response to both environmental and genetic regulatory factors. Work from several laboratories has highlighted that regulation of hilA expression is a key point for controlling expression of the invasive phenotype. A number of positive regulators of hilA expression have been identified including csrAB, sirA/barA, pstS, hilC/sirC/sprA, fis, and hilD. HilD, an AraC/XylS type transcriptional regulator, is of particular importance as a mutation in hilD results in a 14-fold decrease in chromosomal hilA::Tn5lacZY-080 expression and a 53-fold decrease in invasion of HEp-2 cells. It is believed that HilD directly regulates hilA expression as it has been shown to bind to hilA promoter sequences. In addition, our research group, and others, have identified genes (hilE, hha, pag, and lon) that negatively affect hilA transcription. HilE appears to be an important Salmonella-specific regulator that plays a critical role in inactivating hilA expression. Recent work in our lab has been directed at understanding how environmental signals that affect hilA expression may be processed through a hilE pathway to modulate expression of hilA and the invasive phenotype. The current understanding of this complex regulatory system is reviewed.

• Tuberculosis and Respiratory Diseases
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• v.49 no.2
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• pp.189-197
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• 2000

Background : Tissue inhibitor of metalloproteinase is a natural inhibitor that counteracts pro teolytic enzymes essential to the invasion of cancer cell. Whether or not TIMP-2 gene transfer via adenovirus could inhibit the invasion of lung cancer cell iη vitro was evaluated for the future purpose of gene therapy against lung cancer. Methods : Recombinant adenovirus-TIMP-2(Ad-TIMP-2) was generated by homologous recombination after pACCMV-TIMP-2 and pJM17 were cotransfected into 293 cell by standard calcium phosphate coprecipitate method. Calu-6, one of the most invasive lung cancer cells, was transduced with Ad-TIMP-2 or Ad-$\beta$gal. Anchorage-independent growth and invasiveness were assessed by soft agar clonogenicity assay and invasion assay using two-chamber, well divided by matrigel. Results : Ad-TIMP-2 transduced calu-6 cells produced biologically active TIMP-2 more than 50 times more than parental calu-6. TIMP-2 gene transfer did not suppress the in vitro tumorigenicity. However, two chamber well assay revealed that Ad-TIMP-2 transduction reduced the invasiveness of calu-6 efficiently (12% compared with parental cell) even at low 10moi. Conclusion : Even though TIMP-2 gene transfer did not inhibit in vitro tumorigenicity, it did inhibit invasion of lung cancer cell in vitro. The inhibition of invasion by Ad-TIMP-2 may be a useful strategy for the treatment of lung cancer.