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1.  Hippuristanol Reduces the Viability of Primary Effusion Lymphoma Cells both in Vitro and in Vivo 
Marine Drugs  2013;11(9):3410-3424.
Primary effusion lymphoma (PEL) caused by Kaposi’s sarcoma-associated herpesvirus (also known as human herpesvirus-8) shows serious lymphomatous effusion in body cavities. PEL is difficult to treat and there is no standard treatment strategy. Hippuristanol is extracted from Okinawan coral Isis hippuris, and inhibits translational initiation by blocking eukaryotic initiation factor 4A, an ATP-dependent RNA helicase, binding to mRNA. Recently, there has been much interest in targeting translation initiation as an anticancer therapy. Here, we show that treatment of PEL cell lines with hippuristanol resulted in cell cycle arrest at G1 phase, and induced caspases activation and apoptosis. Hippuristanol also reduced the expression of cyclin D2, CDK2, CDK4, CDK6 and prosurvival XIAP and Mcl-1 proteins. Activation of activator protein-1, signal transducers and activators of transcription protein 3 and Akt pathways plays a critical role in the survival and growth of PEL cells. Hippuristanol suppressed the activities of these three pathways by inhibiting the expression of JunB, JunD, c-Fos, signal transducers and activators of transcription protein 3 and Akt proteins. In a xenograft mouse model that showed ascites and diffused organ invasion of PEL cells, treatment with hippuristanol significantly inhibited the growth and invasion of PEL cells compared with untreated mice. The results of the in vitro and in vivo experiments underline the potential usefulness of hippuristanol in the treatment of PEL.
PMCID: PMC3806466  PMID: 24018901
hippuristanol; PEL; AP-1; STAT3; Akt
2.  Antitumor activity and macrophage nitric oxide producing action of medicinal herb, Crassocephalum crepidioides 
Crassocephalum crepidioides, a plant distributed in Okinawa Islands, is known in folk medicine; however, its anticancer activity has not been investigated. The aim of this study was to determine the in vitro and in vivo antitumor activities of C. crepidioides on murine Sarcoma 180 (S-180) and related molecular mechanisms.
The antitumor effect of C. crepidioides was evaluated in S-180-cell-bearing mice. Cell growth was assessed using a colorimetric assay. Nitrite and nitrate levels were measured by colorimetry. The expression levels of inducible NO synthase (iNOS) in murine RAW264.7 macrophages was assessed by reverse transcriptase-polymerase chain reaction. Activation of iNOS promoter was detected by reporter gene. Activation of nuclear factor-κB (NF-κB) was evaluated by electrophoretic mobility shift assay. The role of NF-κB signaling was analyzed using inhibitors of NF-κB and dominant-negative mutants, and Western blot analysis.
C. crepidioides extract delayed tumor growth in S-180-bearing mice. However, it did not inhibit S-180 cell growth in vitro. Supernatant of cultured C. crepidioides-stimulated RAW264.7 macrophages was cytotoxic to S-180 cells. This cytotoxicity was associated with nitric oxide (NO) production. NF-κB signaling pathway was crucial for the transcriptional activation of iNOS gene. Isochlorogenic acid, a component of C. crepidioides, induced NF-κB activation and iNOS expression.
The results highlight the oncolytic and immunopotentiation properties of C. crepidioides mediated through NF-κB-induced release of NO from macrophages.
PMCID: PMC3407475  PMID: 22720874
3.  Beneficial effects of fucoidan in patients with chronic hepatitis C virus infection 
AIM: To evaluate the effects of fucoidan, a complex sulfated polysaccharide extract from marine seaweed, on hepatitis C virus (HCV) RNA load both in vitro and in vivo.
METHODS: HCV-1b replicon-expressing cells were cultured in the presence of fucoidan obtained from Cladosiphon okamuranus Tokida cultivated in Okinawa, Japan, and quantified the level of HCV replication. In an open-label uncontrolled study, 15 patients with chronic hepatitis C, and HCV-related cirrhosis and hepatocellular carcinoma were treated with fucoidan (0.83 g/d) for 12 mo. The clinical symptoms, biochemical tests, and HCV RNA levels were assessed before, during, and after treatment.
RESULTS: Fucoidan dose-dependently inhibited the expression of HCV replicon. At 8-10 mo of treatment with fucoidan, HCV RNA levels were significantly lower relative to the baseline. The same treatment also tended to lower serum alanine aminotransferase levels, and the latter correlated with HCV RNA levels. However, the improved laboratory tests did not translate into significant clinical improvement. Fucoidan had no serious adverse effects.
CONCLUSION: Our findings suggest that fucoidan is safe and useful in the treatment of patients with HCV-related chronic liver diseases. Further controlled clinical trials are needed to confirm the present findings.
PMCID: PMC3351773  PMID: 22611316
Fucoidan; Hepatitis C virus; Replicon
4.  Efficacy of Bidens pilosa Extract against Herpes Simplex Virus Infection In Vitro and In Vivo 
The development of strains of herpes simplex virus (HSV) resistant to drugs has been reported among the immunocompromised patients. Thus, there is a need to develop new therapeutic agents for HSV infections. We evaluated the anti-HSV activity of Bidens pilosa (B. pilosa), a tropical weed, in tissue culture cells and a mouse model. B. pilosa extract showed potent virucidal activity. It inhibited plaque formation and suppressed virus yield in Vero and RAW 264.7 cells infected with HSV-1 and HSV-2. Both the binding of virus to host cells and penetration of virus into cells were also blocked by B. pilosa. Furthermore, B. pilosa was effective against thymidine kinase-deficient and phosphonoacetate-resistant HSV-1 strains. B. pilosa treatment increased the survival rate of HSV-infected mice and limited the development of skin lesions. Our results indicate that B. pilosa has anti-HSV activity and is thus a potentially useful medical plant for treatment of HSV infection.
PMCID: PMC3303703  PMID: 22474501
5.  Induction of CD69 expression by cagPAI-positive Helicobacter pylori infection 
AIM: To investigate and elucidate the molecular mechanism that regulates inducible expression of CD69 by Helicobacter pylori (H. pylori) infection.
METHODS: The expression levels of CD69 in a T-cell line, Jurkat, primary human peripheral blood mononuclear cells (PBMCs), and CD4+ T cells, were assessed by immunohistochemistry, reverse transcription polymerase chain reaction, and flow cytometry. Activation of CD69 promoter was detected by reporter gene. Nuclear factor (NF)-κB activation in Jurkat cells infected with H. pylori was evaluated by electrophoretic mobility shift assay. The role of NF-κB signaling in H. pylori-induced CD69 expression was analyzed using inhibitors of NF-κB and dominant-negative mutants. The isogenic mutants with disrupted cag pathogenicity island (cagPAI) and virD4 were used to elucidate the role of cagPAI-encoding type IV secretion system and CagA in CD69 expression.
RESULTS: CD69 staining was detected in mucosal lymphocytes and macrophages in specimens of patients with H. pylori-positive gastritis. Although cagPAI-positive H. pylori and an isogenic mutant of virD4 induced CD69 expression, an isogenic mutant of cagPAI failed to induce this in Jurkat cells. H. pylori also induced CD69 expression in PBMCs and CD4+ T cells. The activation of the CD69 promoter by H. pylori was mediated through NF-κB. Transfection of dominant-negative mutants of IκBs, IκB kinases, and NF-κB-inducing kinase inhibited H. pylori-induced CD69 activation. Inhibitors of NF-κB suppressed H. pylori-induced CD69 mRNA expression.
CONCLUSION: The results suggest that H. pylori induces CD69 expression through the activation of NF-κB. cagPAI might be relevant in the induction of CD69 expression in T cells. CD69 in T cells may play a role in H. pylori-induced gastritis.
PMCID: PMC3181454  PMID: 21990950
CD69; T cells; Helicobacter pylori; cag pathogenicity island; Nuclear factor-κB
12.  Molecular characterization of Legionella pneumophila-induced interleukin-8 expression in T cells 
BMC Microbiology  2010;10:1.
Legionella pneumophila is the causative agent of human Legionnaire's disease. During infection, the bacterium invades macrophages and lung epithelial cells, and replicates intracellularly. However, little is known about its interaction with T cells. We investigated the ability of L. pneumophila to infect and stimulate the production of interleukin-8 (IL-8) in T cells. The objective of this study was to assess whether L. pneumophila interferes with the immune system by interacting and infecting T cells.
Wild-type L. pneumophila and flagellin-deficient Legionella, but not L. pneumophila lacking a functional type IV secretion system Dot/Icm, replicated in T cells. On the other hand, wild-type L. pneumophila and Dot/Icm-deficient Legionella, but not flagellin-deficient Legionella or heat-killed Legionella induced IL-8 expression. L. pneumophila activated an IL-8 promoter through the NF-κB and AP-1 binding regions. Wild-type L. pneumophila but not flagellin-deficient Legionella activated NF-κB, p38 mitogen-activated protein kinase (MAPK), Jun N-terminal kinase (JNK), and transforming growth factor β-associated kinase 1 (TAK1). Transfection of dominant negative mutants of IκBα, IκB kinase, NF-κB-inducing kinase, TAK1, MyD88, and p38 MAPK inhibited L. pneumophila-induced IL-8 activation. Inhibitors of NF-κB, p38 MAPK, and JNK blocked L. pneumophila-induced IL-8 expression. In addition, c-Jun, JunD, cyclic AMP response element binding protein, and activating transcription factor 1, which are substrates of p38 MAPK and JNK, bound to the AP-1 site of the IL-8 promoter.
Taken together, L. pneumophila induced a flagellin-dependent activation of TAK1, p38 MAPK, and JNK, as well as NF-κB and AP-1, which resulted in IL-8 production in human T cells, presumably contributing to the immune response in Legionnaire's disease.
PMCID: PMC2824691  PMID: 20051107
13.  Human T-Cell Leukemia Virus Type I-Mediated Repression of PDZ-LIM Domain-Containing Protein 2 Involves DNA Methylation But Independent of the Viral Oncoprotein Tax1 
Neoplasia (New York, N.Y.)  2009;11(10):1036-1041.
Human T-cell leukemia virus type I (HTLV-I) is the etiological agent of adult T-cell leukemia (ATL). Our recent studies have shown that one important mechanism of HTLV-I-Mediated tumorigenesis is through PDZ-LIM domain-containing protein 2 (PDLIM2) repression, although the involved mechanism remains unknown. Here, we further report that HTLV-I-Mediated PDLIM2 repression was a pathophysiological event and the PDLIM2 repression involved DNA methylation. Whereas DNA methyltransferases 1 and 3b but not 3a were upregulated in HTLV-I-transformed T cells, the hypomethylating agent 5-aza-2′-deoxycytidine (5-aza-dC) restored PDLIM2 expression and induced death of these malignant cells. Notably, the PDLIM2 repression was independent of the viral regulatory protein Tax because neither short-term induction nor long-term stable expression of Tax could downregulate PDLIM2 expression. These studies provide important insights into PDLIM2 regulation, HTLV-I leukemogenicity, long latency, and cancer health disparities. Given the efficient antitumor activity with no obvious toxicity of 5-aza-dC, these studies also suggest potential therapeutic strategies for ATL.
PMCID: PMC2745669  PMID: 19794962
14.  Helicobacter pylori-Induced Interleukin-12 p40 Expression▿  
Infection and Immunity  2009;77(4):1337-1348.
Interleukin-12 (IL-12) is a heterodimeric cytokine produced by antigen-presenting cells that promotes the development of T-helper lymphocyte 1 (Th1). Chronic gastritis induced by Helicobacter pylori is considered a Th1-mediated process. IL-12 levels in gastric biopsy samples of H. pylori-infected patients are higher than in those of uninfected individuals, but the cellular source of IL-12 remains elusive. IL-12 staining was detected in mucosal epithelial cells, lymphocytes, and macrophages in specimens of patients with H. pylori-positive gastritis. Therefore, we investigated IL-12 p40 mRNA induction by H. pylori in gastric epithelial cells and T cells. Although cag pathogenicity island (PAI)-positive H. pylori induced IL-12 p40 mRNA expression, an isogenic mutant of the cag PAI failed to induce it in both cell types. Supernatants from H. pylori cultures and H. pylori VacA induced IL-12 p40 mRNA expression in T cells but not in epithelial cells. The activation of the IL-12 p40 promoter by H. pylori was mediated through NF-κB. The transfection of IκB kinase and NF-κB-inducing kinase dominant-negative mutants inhibited H. pylori-induced IL-12 p40 activation. Inhibitors of NF-κB, phosphatidylinositol 3-kinase, p38 mitogen-activated protein kinase, and Hsp90 suppressed H. pylori- and VacA-induced IL-12 p40 mRNA expression. The results indicate that H. pylori induces IL-12 p40 expression by the activation of NF-κB, phosphatidylinositol 3-kinase, and p38 mitogen-activated protein kinase. Hsp90 is also a crucial regulator of H. pylori-induced IL-12 p40 expression. In addition to the cag PAI, VacA might be relevant in the induction of IL-12 expression and a Th1-polarized response only in T cells.
PMCID: PMC2663134  PMID: 19179414
15.  NF-κB activation by Helicobacter pylori requires Akt-mediated phosphorylation of p65 
BMC Microbiology  2009;9:36.
The inflammatory response in Helicobacter pylori-infected gastric tissue is mediated by cag pathogenicity island (PAI)-dependent activation of nuclear factor-κB (NF-κB). Phosphatidylinositol 3-kinase (PI3K)/Akt signaling is known to play a role in NF-κB activation, but little information is available on the relationship between H. pylori and PI3K/Akt signaling in gastric epithelial cells. We examined whether H. pylori activates Akt in gastric epithelial cells, the role of cag PAI in this process and the role of Akt in regulating H. pylori-induced NF-κB activation.
Phosphorylated Akt was detected in epithelial cells of H. pylori-positive gastric tissues. Although Akt was activated in MKN45 and AGS cells by coculture with cag PAI-positive H. pylori strains, a cag PAI-negative mutant showed no activation of Akt. H. pylori also induced p65 phosphorylation. PI3K inhibitor suppressed H. pylori-induced p65 phosphorylation and NF-κB transactivation, as well as interleukin-8 expression. Furthermore, transfection with a dominant-negative Akt inhibited H. pylori-induced NF-κB transactivation. Transfection with small interference RNAs for p65 and Akt also inhibited H. pylori-induced interleukin-8 expression.
The results suggest that cag PAI-positive H. pylori activates Akt in gastric epithelial cells and this may contribute to H. pylori-mediated NF-κB activation associated with mucosal inflammation and carcinogenesis.
PMCID: PMC2653507  PMID: 19216748
16.  Anti-adult T-cell leukemia/lymphoma effects of indole-3-carbinol 
Retrovirology  2009;6:7.
Adult T-cell leukemia/lymphoma (ATLL) is a malignancy derived from T cells infected with human T-cell leukemia virus type 1 (HTLV-1), and it is known to be resistant to standard anticancer therapies. Indole-3-carbinol (I3C), a naturally occurring component of Brassica vegetables such as cabbage, broccoli and Brussels sprout, is a promising chemopreventive agent as it is reported to possess antimutagenic, antitumorigenic and antiestrogenic properties in experimental studies. The aim of this study was to determine the potential anti-ATLL effects of I3C both in vitro and in vivo.
In the in vitro study, I3C inhibited cell viability of HTLV-1-infected T-cell lines and ATLL cells in a dose-dependent manner. Importantly, I3C did not exert any inhibitory effect on uninfected T-cell lines and normal peripheral blood mononuclear cells. I3C prevented the G1/S transition by reducing the expression of cyclin D1, cyclin D2, Cdk4 and Cdk6, and induced apoptosis by reducing the expression of XIAP, survivin and Bcl-2, and by upregulating the expression of Bak. The induced apoptosis was associated with activation of caspase-3, -8 and -9, and poly(ADP-ribose) polymerase cleavage. I3C also suppressed IκBα phosphorylation and JunD expression, resulting in inactivation of NF-κB and AP-1. Inoculation of HTLV-1-infected T cells in mice with severe combined immunodeficiency resulted in tumor growth. The latter was inhibited by treatment with I3C (50 mg/kg/day orally), but not the vehicle control.
Our preclinical data suggest that I3C could be potentially a useful chemotherapeutic agent for patients with ATLL.
PMCID: PMC2635345  PMID: 19146708
17.  Human T-cell leukemia virus type I infects human lung epithelial cells and induces gene expression of cytokines, chemokines and cell adhesion molecules 
Retrovirology  2008;5:86.
Human T-cell leukemia virus type I (HTLV-I) is associated with pulmonary diseases, characterized by bronchoalveolar lymphocytosis, which correlates with HTLV-I proviral DNA in carriers. HTLV-I Tax seems to be involved in the development of such pulmonary diseases through the local production of inflammatory cytokines and chemokines in T cells. However, little is known about induction of these genes by HTLV-I infection in lung epithelial cells.
We tested infection of lung epithelial cells by HTLV-I by coculture studies in which A549 alveolar and NCI-H292 tracheal epithelial cell lines were cocultured with MT-2, an HTLV-I-infected T-cell line. Changes in the expression of several cellular genes were assessed by reverse transcription-polymerase chain reaction, enzyme-linked immunosorbent assay and flow cytometry. Coculture with MT-2 cells resulted in infection of lung epithelial cells as confirmed by detection of proviral DNA, HTLV-I Tax expression and HTLV-I p19 in the latter cells. Infection was associated with induction of mRNA expression of various cytokines, chemokines and cell adhesion molecule. NF-κB and AP-1 were also activated in HTLV-I-infected lung epithelial cells. In vivo studies showed Tax protein in lung epithelial cells of mice bearing Tax and patients with HTLV-I-related pulmonary diseases.
Our results suggest that HTLV-I infects lung epithelial cells, with subsequent production of cytokines, chemokines and cell adhesion molecules through induction of NF-κB and AP-1. These changes can contribute to the clinical features of HTLV-I-related pulmonary diseases.
PMCID: PMC2556696  PMID: 18808681
18.  Helicobacter pylori Induces CCL20 Expression▿  
Infection and Immunity  2007;75(11):5223-5232.
CCL20 attracts immature dendritic cells and memory T cells and plays a role on mucosal surfaces in inflammation. However, whether Helicobacter pylori infection induces CCL20 in human gastric epithelial cells remains to be determined. The aim of this study was to analyze the molecular mechanism of H. pylori-induced CCL20 expression. Expression of CCL20 mRNA was assessed by reverse transcription-PCR. Five normal and five H. pylori-infected gastric tissue samples were stained immunohistochemically for CCL20. A luciferase assay was used to monitor activation of the CCL20 gene promoter, and an electrophoretic mobility shift assay was used to explore the binding of transcription factors to this promoter. The CCL20 expression in epithelial cells of H. pylori-positive tissues was higher than that in H. pylori-negative tissues. H. pylori induced CCL20 expression in gastric epithelial cell lines, and the induction was dependent on an intact cag pathogenicity island. Activation of the CCL20 promoter by H. pylori occurred through the action of NF-κB. Transfection of IκB kinase and NF-κB-inducing kinase dominant negative mutants inhibited H. pylori-mediated activation of CCL20. Treatment with an inhibitor of Hsp90 suppressed H. pylori-induced CCL20 mRNA due to deactivation of NF-κB. Collectively, these results suggest that H. pylori activates NF-κB through an intracellular signaling pathway that involves IκB kinase and NF-κB-inducing kinase, leading to CCL20 gene transcription, and that Hsp90 is a crucial regulator of H. pylori-induced CCL20 expression, presumably contributing to the immune response in H. pylori.
PMCID: PMC2168315  PMID: 17724069
19.  Mechanisms of Legionella pneumophila-induced interleukin-8 expression in human lung epithelial cells 
BMC Microbiology  2007;7:102.
Legionella pneumophila is a facultative intracellular bacterium, capable of replicating within the phagosomes of macrophages and monocytes, but little is known about its interaction with human lung epithelial cells. We investigated the effect of L. pneumophila on the expression of interleukin-8 (IL-8) in human A549 alveolar and NCI-H292 tracheal epithelial cell lines.
Infection of L. pneumophila strain, but not heat-killed strain, resulted in upregulation of IL-8. IL-8 mRNA expression was induced immediately after the infection and its signal became gradually stronger until 24 h after infection. On the other hand, IL-8 expression in A549 cells infected with L. pneumophila lacking a functional type IV secretion system was transient. The IL-8 expression was slightly induced at 16 h and increased at 24 h after infection with flagellin-deficient Legionella. Activation of the IL-8 promoter by L. pneumophila infection occurred through the action of nuclear factor-κB (NF-κB). Transfection of dominant negative mutants of NF-κB-inducing kinase, IκB kinase and IκB inhibited L. pneumophila-mediated activation of IL-8 promoter. Treatment with hsp90 inhibitor suppressed L. pneumophila-induced IL-8 mRNA due to deactivation of NF-κB.
Collectively, these results suggest that L. pneumophila induces activation of NF-κB through an intracellular signaling pathway that involves NF-κB-inducing kinase and IκB kinase, leading to IL-8 gene transcription, and that hsp90 acts as a crucial regulator in L. pneumophila-induced IL-8 expression, presumably contributing to immune response in L. pneumophila. The presence of flagellin and a type IV secretion system are critical for Legionella to induce IL-8 expression in lung epithelial cells.
PMCID: PMC2213657  PMID: 18034886

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