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Sample records for inhibitor r-roscovitine suppresses

  1. The cyclin dependent kinase inhibitor (R)-roscovitine mediates selective suppression of alloreactive human T cells but preserves pathogen-specific and leukemia-specific effectors.

    PubMed

    Nellore, Anoma; Liu, Bianling; Patsoukis, Nikolaos; Boussiotis, Vassiliki A; Li, Lequn

    2014-01-01

    Graft versus host disease (GvHD), mediated by donor T cells, remains the primary cause of non-relapse mortality after allogeneic hematopoietic stem cell transplantation and novel therapeutic approaches are required. Cdk2 is a critical node of signal integration and programming of T cell responses towards immunity versus anergy but is dispensable for hematopoiesis and thymocyte development. We examined the effects of pharmacologic Cdk2 inhibition on alloreactive human T cells. Inhibition of Cdk2 blocked expansion of alloreactive T cells upon culture with HLA-mismatched dendritic cells and prevented generation of IFN-γ-producing alloantigen-specific effectors. In contrast, Cdk2 inhibition preserved effectors specific for Wilms' tumor 1 (WT1) leukemia antigen and for CMV as determined by WT1-specific and CMV-specific pentamers. Cdk2 inhibition preserved Treg cells, which have the ability to prevent GvHD while maintaining GvL. Thus, Cdk inhibitors may improve allogeneic HSCT by reducing alloreactivity and GvHD without loss of pathogen-specific and leukemia-specific immunity. PMID:24631965

  2. The cyclin dependent kinase inhibitor (R)-roscovitine mediates selective suppression of alloreactive human T cells but preserves pathogen-specific and leukemia-specific effectors

    PubMed Central

    Nellore, Anoma; Liu, Bianling; Patsoukis, Nikolaos; Boussiotis, Vassiliki A.; Li, Lequn

    2014-01-01

    Graft versus host disease (GvHD), mediated by donor T cells, remains the primary cause of non-relapse mortality after allogeneic hematopoietic stem cell transplantation and novel therapeutic approaches are required. Cdk2 is a critical node of signal integration and programming of T cell responses towards immunity versus anergy but is dispensable for hematopoiesis and thymocyte development. We examined the effects of pharmacologic Cdk2 inhibition on alloreactive human T cells. Inhibition of Cdk2 blocked expansion of alloreactive T cells upon culture with HLA-mismatched dendritic cells and prevented generation of IFN-γ-producing alloantigen-specific effectors. In contrast, Cdk2 inhibition preserved effectors specific for Wilms’ tumor 1 (WT1) leukemia antigen and for CMV as determined by WT1-specific and CMV-specific pentamers. Cdk2 inhibition preserved Treg cells, which have the ability to prevent GvHD while maintaining GvL. Thus, Cdk inhibitors may improve allogeneic HSCT by reducing alloreactivity and GvHD without loss of pathogen-specific and leukemia-specific immunity. PMID:24631965

  3. The cyclin-dependent kinase inhibitor seliciclib (R-roscovitine; CYC202) decreases the expression of mitotic control genes and prevents entry into mitosis.

    PubMed

    Whittaker, Steven R; Te Poele, Robert H; Chan, Florence; Linardopoulos, Spiros; Walton, Michael I; Garrett, Michelle D; Workman, Paul

    2007-12-15

    The cyclin-dependent kinase (CDK) inhibitor seliciclib (R-roscovitine, CYC202) shows promising antitumor activity in preclinical models and is currently undergoing phase II clinical trials. Inhibition of the CDKs by seliciclib could contribute to cell cycle arrest and apoptosis seen with the drug. However, it is common for drugs to exert multiple effects on gene expression and biochemical pathways. To further our understanding of the molecular pharmacology of seliciclib, we employed cDNA microarrays to determine changes in gene expression profiles induced by the drug in HT29 human colon cancer cells. Concentrations of seliciclib were used that inhibited RB phosphorylation and cell proliferation. An increase in the mRNA expression for CJUN and EGR1 was confirmed by Western blotting, consistent with activation of the ERK1/2 MAPK pathway by seliciclib. Transcripts of key genes required for the progression through mitosis showed markedly reduced expression, including Aurora-A/B (AURK-A/B), Polo-like kinase (PLK), cyclin B2 (CCNB2), WEE1 and CDC25C. Reduced expression of these mitotic genes was also seen at the protein level. siRNA-mediated depletion of Aurora-A protein led to an arrest of cells in the G(2)/M phase, consistent with the effects of seliciclib treatment. Inhibition of mitotic entry following seliciclib treatment was indicated by a reduction of histone H3 phosphorylation, which is catalyzed by Aurora-B, and by decreased expression of mitotic markers, including phospho-protein phosphatase 1 alpha. The results indicate a potential mechanism through which seliciclib prevents entry into mitosis. Gene expression profiling has generated hypotheses that led to an increase in our knowledge of the cellular effects of seliciclib and could provide potential pharmacodynamic or response biomarkers for use in animal models and clinical trials. PMID:18075315

  4. R-roscovitine reduces lung inflammation induced by lipoteichoic acid and Streptococcus pneumoniae.

    PubMed

    Hoogendijk, Arie J; Roelofs, Joris J T H; Duitman, Janwillem; van Lieshout, Miriam H P; Blok, Dana C; van der Poll, Tom; Wieland, Catharina W

    2012-01-01

    Bacterial pneumonia remains associated with high morbidity and mortality. The gram-positive pathogen Streptococcus pneumoniae is the most common cause of community-acquired pneumonia. Lipoteichoic acid (LTA) is an important proinflammatory component of the gram-positive bacterial cell wall. R-roscovitine, a purine analog, is a potent cyclin-dependent kinase (CDK)-1, -2, -5 and -7 inhibitor that has the ability to inhibit the cell cycle and to induce polymorphonuclear cell (PMN) apoptosis. We sought to investigate the effect of R-roscovitine on LTA-induced activation of cell lines with relevance for lung inflammation in vitro and on lung inflammation elicited by either LTA or viable S. pneumoniae in vivo. In vitro R-roscovitine enhanced apoptosis in PMNs and reduced tumor necrosis factor (TNF)-α and keratinocyte chemoattractant (KC) production in MH-S (alveolar macrophage) and MLE-12/MLE-15 (respiratory epithelial) cell lines. In vivo R-roscovitine treatment reduced PMN numbers in bronchoalveolar lavage fluid during LTA-induced lung inflammation; this effect was reversed by inhibiting apoptosis. Postponed treatment with R-roscovitine (24 and 72 h) diminished PMN numbers in lung tissue during gram-positive pneumonia; this step was associated with a transient increase in pulmonary bacterial loads. R-roscovitine inhibits proinflammatory responses induced by the gram-positive stimuli LTA and S. pneumoniae. R-roscovitine reduces PMN numbers in lungs upon LTA administration by enhancing apoptosis. The reduction in PMN numbers caused by R-roscovitine during S. pneumoniae pneumonia may hamper antibacterial defense. PMID:22692577

  5. Novel R-roscovitine NO-donor hybrid compounds as potential pro-resolution of inflammation agents

    PubMed Central

    Montanaro, Gabriele; Bertinaria, Massimo; Rolando, Barbara; Fruttero, Roberta; Lucas, Christopher D.; Dorward, David A.; Rossi, Adriano G.; Megson, Ian L.; Gasco, Alberto

    2013-01-01

    Neutrophils play a pivotal role in the pathophysiology of multiple human inflammatory diseases. Novel pharmacological strategies which drive neutrophils to undergo programmed cell death (apoptosis) have been shown to facilitate the resolution of inflammation. Both the cyclin-dependent kinase inhibitor (CDKi) R-roscovitine and nitric oxide (NO) have been shown to enhance apoptosis of neutrophils and possess pro-resolution of inflammation properties. In order to search for new multi-target pro-resolution derivatives, here we describe the design, synthesis and investigation of the biological potential of a small series of hybrid compounds obtained by conjugating R-roscovitine with two different NO-donor moieties (compounds 2, 9a, 9c). The synthesized compounds were tested as potential pro-resolution agents, with their ability to promote human neutrophil apoptosis evaluated. Both compound 9a and 9c showed an increased pro-apoptotic activity when compared with either R-roscovitine or structurally related compounds devoid of the ability to release NO (des-NO analogues). Inhibition of either NO-synthase or soluble guanylate cyclase did not affect the induction of apoptosis by the R-roscovitine derivatives, similar to that reported for other classes of NO-donors. In contrast the NO scavenger PTIO prevented the enhanced apoptosis seen with compound 9a over R-roscovitine. These data show that novel compounds such as CDKi–NO-donor hybrids may have additive pro-resolution of inflammation effects. PMID:23394865

  6. State-dependent block of HERG potassium channels by R-roscovitine: implications for cancer therapy

    PubMed Central

    Ganapathi, Sindura B.; Kester, Mark; Elmslie, Keith S.

    2009-01-01

    Human ether-a-go-go-related gene (HERG) potassium channel acts as a delayed rectifier in cardiac myocytes and is an important target for both pro- and antiarrhythmic drugs. Many drugs have been pulled from the market for unintended HERG block causing arrhythmias. Conversely, recent evidence has shown that HERG plays a role in cell proliferation and is overexpressed both in multiple tumor cell lines and in primary tumor cells, which makes HERG an attractive target for cancer treatment. Therefore, a drug that can block HERG but that does not induce cardiac arrhythmias would have great therapeutic potential. Roscovitine is a cyclin-dependent kinase (CDK) inhibitor that is in phase II clinical trials as an anticancer agent. In the present study we show that R-roscovitine blocks HERG potassium current (human embryonic kidney-293 cells stably expressing HERG) at clinically relevant concentrations. The block (IC50 = 27 μM) was rapid (τ = 20 ms) and reversible (τ = 25 ms) and increased with channel activation, which supports an open channel mechanism. Kinetic study of wild-type and inactivation mutant HERG channels supported block of activated channels by roscovitine with relatively little effect on either closed or inactivated channels. A HERG gating model reproduced all roscovitine effects. Our model of open channel block by roscovitine may offer an explanation of the lack of arrhythmias in clinical trials using roscovitine, which suggests the utility of a dual CDK/HERG channel block as an adjuvant cancer therapy. PMID:19244476

  7. Inhibition of human immunodeficiency virus type-1 by cdk inhibitors.

    PubMed

    Guendel, Irene; Agbottah, Emmanuel T; Kehn-Hall, Kylene; Kashanchi, Fatah

    2010-01-01

    Current therapy for human immunodeficiency virus (HIV-1) infection relies primarily on the administration of anti-retroviral nucleoside analogues, either alone or in combination with HIV-protease inhibitors. Although these drugs have a clinical benefit, continuous therapy with the drugs leads to drug-resistant strains of the virus. Recently, significant progress has been made towards the development of natural and synthetic agents that can directly inhibit HIV-1 replication or its essential enzymes. We previously reported on the pharmacological cyclin-dependent kinase inhibitor (PCI) r-roscovitine as a potential inhibitor of HIV-1 replication. PCIs are among the most promising novel antiviral agents to emerge over the past few years. Potent activity on viral replication combined with proliferation inhibition without the emergence of resistant viruses, which are normally observed in HAART patients; make PCIs ideal candidates for HIV-1 inhibition. To this end we evaluated twenty four cdk inhibitors for their effect on HIV-1 replication in vitro. Screening of these compounds identified alsterpaullone as the most potent inhibitor of HIV-1 with activity at 150 nM. We found that alsterpaullone effectively inhibits cdk2 activity in HIV-1 infected cells with a low IC50 compared to control uninfected cells. The effects of alsterpaullone were associated with suppression of cdk2 and cyclin expression. Combining both alsterpaullone and r-roscovitine (cyc202) in treatment exhibited even stronger inhibitory activities in HIV-1 infected PBMCs. PMID:20334651

  8. Suppression of Coronavirus Replication by Cyclophilin Inhibitors

    PubMed Central

    Tanaka, Yoshikazu; Sato, Yuka; Sasaki, Takashi

    2013-01-01

    Coronaviruses infect a variety of mammalian and avian species and cause serious diseases in humans, cats, mice, and birds in the form of severe acute respiratory syndrome (SARS), feline infectious peritonitis (FIP), mouse hepatitis, and avian infectious bronchitis, respectively. No effective vaccine or treatment has been developed for SARS-coronavirus or FIP virus, both of which cause lethal diseases. It has been reported that a cyclophilin inhibitor, cyclosporin A (CsA), could inhibit the replication of coronaviruses. CsA is a well-known immunosuppressive drug that binds to cellular cyclophilins to inhibit calcineurin, a calcium-calmodulin-activated serine/threonine-specific phosphatase. The inhibition of calcineurin blocks the translocation of nuclear factor of activated T cells from the cytosol into the nucleus, thus preventing the transcription of genes encoding cytokines such as interleukin-2. Cyclophilins are peptidyl-prolyl isomerases with physiological functions that have been described for many years to include chaperone and foldase activities. Also, many viruses require cyclophilins for replication; these include human immunodeficiency virus, vesicular stomatitis virus, and hepatitis C virus. However, the molecular mechanisms leading to the suppression of viral replication differ for different viruses. This review describes the suppressive effects of CsA on coronavirus replication. PMID:23698397

  9. Suppression of coronavirus replication by cyclophilin inhibitors.

    PubMed

    Tanaka, Yoshikazu; Sato, Yuka; Sasaki, Takashi

    2013-05-01

    Coronaviruses infect a variety of mammalian and avian species and cause serious diseases in humans, cats, mice, and birds in the form of severe acute respiratory syndrome (SARS), feline infectious peritonitis (FIP), mouse hepatitis, and avian infectious bronchitis, respectively. No effective vaccine or treatment has been developed for SARS-coronavirus or FIP virus, both of which cause lethal diseases. It has been reported that a cyclophilin inhibitor, cyclosporin A (CsA), could inhibit the replication of coronaviruses. CsA is a well-known immunosuppressive drug that binds to cellular cyclophilins to inhibit calcineurin, a calcium-calmodulin-activated serine/threonine-specific phosphatase. The inhibition of calcineurin blocks the translocation of nuclear factor of activated T cells from the cytosol into the nucleus, thus preventing the transcription of genes encoding cytokines such as interleukin-2. Cyclophilins are peptidyl-prolyl isomerases with physiological functions that have been described for many years to include chaperone and foldase activities. Also, many viruses require cyclophilins for replication; these include human immunodeficiency virus, vesicular stomatitis virus, and hepatitis C virus. However, the molecular mechanisms leading to the suppression of viral replication differ for different viruses. This review describes the suppressive effects of CsA on coronavirus replication. PMID:23698397

  10. Suppression of caspase-11 expression by histone deacetylase inhibitors

    SciTech Connect

    Heo, Hyejung; Yoo, Lang; Shin, Ki Soon; Kang, Shin Jung

    2009-01-02

    It has been well documented that histone deacetylase inhibitors suppress inflammatory gene expression. Therefore, we investigated whether histone deacetylase inhibitors modulate the expression of caspase-11 that is known as an inducible caspase regulating both inflammation and apoptosis. In the present study, we show that sodium butyrate and trichostatin A, two structurally unrelated inhibitors of histone deacetylase (HDAC), effectively suppressed the induction of caspase-11 in mouse embryonic fibroblasts stimulated with lipopolysaccharides. Sodium butyrate inhibited the activation of upstream signaling events for the caspase-11 induction such as activation of p38 mitogen-activated protein kinase and c-Jun N-terminal kinase, degradation of inhibitor of {kappa}B, and activation of nuclear factor-{kappa}B. These results suggest that the HDAC inhibitor suppressed cytosolic signaling events for the induction of caspase-11 by inhibiting the deacetylation of non-histone proteins.

  11. Selective Serotonin Reuptake Inhibitor Suppression of HIV Infectivity and Replication

    PubMed Central

    Benton, Tami; Lynch, Kevin; Dubé, Benoit; Gettes, David R.; Tustin, Nancy B.; Lai, Jian Ping; Metzger, David S.; Blume, Joshua; Douglas, Steven D.; Evans, Dwight L.

    2010-01-01

    Objective To test the hypothesis that the selective serotonin reuptake inhibitor (SSRI) citalopram would down regulate HIV infectivity and that the greatest effects would be seen in people with depression. Depression is a risk factor for morbidity and mortality in HIV/AIDS. Serotonin (5-HT) neurotransmission has been implicated in the pathobiology of depression, and pharmacologic therapies for depression target this system. The 5-HT transporter and 5-HT receptors are widely distributed throughout the central nervous and immune systems. Depression has been associated with suppression of natural killer cells (NK) cells and CD8+ lymphocytes, key regulators of HIV infection. Methods Ex-vivo models for acute and chronic HIV infection were used to study the effects of citalopram on HIV viral infection and replication, in 48 depressed and non-depressed women. For both the acute and chronic infection models, HIV reverse transcriptase (RT) activity was measured in the citalopram treatment condition and the control condition. Results The SSRI significantly downregulated the RT response in both the acute and chronic infection models. Specifically, citalopram significantly decreased the acute HIV infectivity of macrophages. Citalopram also significantly decreased HIV viral replication in the latently infected T-cell line and in the latently infected macrophage cell line. There was no difference in down-regulation by depression status. Conclusions These studies suggest that an SSRI enhances NK/CD8 non-cytolytic HIV suppression in HIV/AIDS and decreases HIV viral infectivity of macrophages, ex vivo, suggesting the need for in vivo studies to determine a potential role for agents targeting serotonin in the host defense against HIV. PMID:20947783

  12. Suppression of BRCA1 sensitizes cells to proteasome inhibitors

    PubMed Central

    Gu, Y; Bouwman, P; Greco, D; Saarela, J; Yadav, B; Jonkers, J; Kuznetsov, S G

    2014-01-01

    BRCA1 is a multifunctional protein best known for its role in DNA repair and association with breast and ovarian cancers. To uncover novel biologically significant molecular functions of BRCA1, we tested a panel of 198 approved and experimental drugs to inhibit growth of MDA-MB-231 breast cancer cells depleted for BRCA1 by siRNA. 26S proteasome inhibitors bortezomib and carfilzomib emerged as a new class of selective BRCA1-targeting agents. The effect was confirmed in HeLa and U2OS cancer cell lines using two independent siRNAs, and in mouse embryonic stem (ES) cells with inducible deletion of Brca1. Bortezomib treatment did not cause any increase in nuclear foci containing phosphorylated histone H2AX, and knockdown of BRCA2 did not entail sensitivity to bortezomib, suggesting that the DNA repair function of BRCA1 may not be directly involved. We found that a toxic effect of bortezomib on BRCA1-depleted cells is mostly due to deregulated cell cycle checkpoints mediated by RB1-E2F pathway and 53BP1. Similar to BRCA1, depletion of RB1 also conferred sensitivity to bortezomib, whereas suppression of E2F1 or 53BP1 together with BRCA1 reduced induction of apoptosis after bortezomib treatment. A gene expression microarray study identified additional genes activated by bortezomib treatment only in the context of inactivation of BRCA1 including a critical involvement of the ERN1-mediated unfolded protein response. Our data indicate that BRCA1 has a novel molecular function affecting cell cycle checkpoints in a manner dependent on the 26S proteasome activity. PMID:25522274

  13. Suppression of BRCA1 sensitizes cells to proteasome inhibitors.

    PubMed

    Gu, Y; Bouwman, P; Greco, D; Saarela, J; Yadav, B; Jonkers, J; Kuznetsov, S G

    2014-01-01

    BRCA1 is a multifunctional protein best known for its role in DNA repair and association with breast and ovarian cancers. To uncover novel biologically significant molecular functions of BRCA1, we tested a panel of 198 approved and experimental drugs to inhibit growth of MDA-MB-231 breast cancer cells depleted for BRCA1 by siRNA. 26S proteasome inhibitors bortezomib and carfilzomib emerged as a new class of selective BRCA1-targeting agents. The effect was confirmed in HeLa and U2OS cancer cell lines using two independent siRNAs, and in mouse embryonic stem (ES) cells with inducible deletion of Brca1. Bortezomib treatment did not cause any increase in nuclear foci containing phosphorylated histone H2AX, and knockdown of BRCA2 did not entail sensitivity to bortezomib, suggesting that the DNA repair function of BRCA1 may not be directly involved. We found that a toxic effect of bortezomib on BRCA1-depleted cells is mostly due to deregulated cell cycle checkpoints mediated by RB1-E2F pathway and 53BP1. Similar to BRCA1, depletion of RB1 also conferred sensitivity to bortezomib, whereas suppression of E2F1 or 53BP1 together with BRCA1 reduced induction of apoptosis after bortezomib treatment. A gene expression microarray study identified additional genes activated by bortezomib treatment only in the context of inactivation of BRCA1 including a critical involvement of the ERN1-mediated unfolded protein response. Our data indicate that BRCA1 has a novel molecular function affecting cell cycle checkpoints in a manner dependent on the 26S proteasome activity. PMID:25522274

  14. Suppression of dioxins by S-N inhibitors in pilot-scale experiments.

    PubMed

    Zhan, Ming-Xiu; Fu, Jian-Ying; Chen, Tong; Lin, Xiao-Qing; Li, Xiao-Dong; Yan, Jian-Hua; Buekens, Alfons

    2016-08-01

    S-N inhibitors like thiourea and sewage sludge decomposition gases (SDG) are relatively novel dioxins suppressants and their efficiencies are proven in numerous lab-scale experiments. In this study, the suppression effects of both thiourea and SDG on the formation of dioxins are systematically tested in a pilot-scale system, situated at the bypass of a hazardous waste incinerator (HWI). Moreover, a flue gas recirculation system is used to get high dioxin suppression efficiencies. Operating experience shows that this system is capable of stable operation and to keep gaseous suppressant compounds at a high and desirable molar ratio (S + N)/Cl level in the flue gas. The suppression efficiencies of dioxins are investigated in flue gas both without and with addition of S-N inhibitors. A dioxin reduction of more than 80 % is already achieved when the (S + N)/Cl molar ratio is increased to ca. 2.20. When this (S + N)/Cl molar ratio has augmented to 4.18 by applying suppressant recirculation, the residual PCDD/Fs concentration in the flue gas shrank from 1.22 to 0.08 ng I-TEQ/Nm(3). Furthermore, the congener distribution of dioxins is analysed to find some possible explanation or suppression mechanism. In addition, a correlation analysis between (S + N)/Cl molar ratios and PCDD/Fs is also conducted to investigate the chief functional compounds for dioxin suppression. PMID:27164888

  15. Inhibitors of cyclooxygenase-2 (COX-2) suppressed the proliferation and differentiation of human leukaemia cell lines.

    PubMed

    Nakanishi, Y; Kamijo, R; Takizawa, K; Hatori, M; Nagumo, M

    2001-08-01

    Prostaglandins (PG) are known to play important roles in the proliferation and differentiation of leukaemia cells. The effect of the inhibitors of cyclooxygenase-2 (COX-2), a rate-limiting enzyme for the synthesis of PG, on the proliferation and differentiation of leukaemia cell lines was investigated. COX-2 inhibitors, NS-398 and nabumetone, suppressed the proliferation of U-937 and ML-1 cells by inducing a G0/G1 cell-cycle arrest. Cell-cycle arrest induced by these COX-2 inhibitors was not associated with an upregulation of the cyclin-dependent kinase inhibitors. COX-2 inhibitors also inhibited the differentiation of these cells induced by interferon-gamma (IFN-gamma), tumour necrosis factor-alpha (TNF-alpha) and retinoic acid (RA). Treatment with NS-398 did not suppress the levels of PGs produced by these cells. Although COX-2 antisense oligonucleotide showed a similar inhibitory effect on these cells, its inhibitory effect was smaller than that of NS-398. These results suggest that COX-2 inhibitors may suppress the proliferation and differentiation of leukaemia cells both via COX-2-dependent and -independent pathways. PMID:11506967

  16. The dipeptidyl peptidase-4 inhibitor sitagliptin suppresses mouse colon tumorigenesis in type 2 diabetic mice.

    PubMed

    Yorifuji, Naoki; Inoue, Takuya; Iguchi, Munetaka; Fujiwara, Kaori; Kakimoto, Kazuki; Nouda, Sadaharu; Okada, Toshihiko; Kawakami, Ken; Abe, Yosuke; Takeuchi, Toshihisa; Higuchi, Kazuhide

    2016-02-01

    Patients with type 2 diabetes mellitus are known to have an increased risk of colorectal neoplasia. Dipeptidyl peptidase-4 (DPP-4) inhibitors have been used as a new therapeutic tool for type 2 diabetes. Since the substrates for DPP-4 include intestinotrophic hormones and chemokines such as GLP-2 and stromal cell-derived factor-1 (SDF-1), which are associated with tumor progression, DPP-4 inhibitors may increase the risk of colorectal tumors. However, the influence of DPP-4 inhibitors on colorectal neoplasia in patients with type 2 diabetes remains unknown. In the present study, we show that long-term administration of a DPP-4 inhibitor, sitagliptin (STG), suppressed colon carcinogenesis in leptin-deficient (ob/ob) C57BL/6J mice. Colonic mucosal concentrations of glucagon‑like peptide-1 (GLP-1) and GLP-2 were significantly elevated in the ob/ob mice. However, mucosal GLP concentrations and the plasma level of SDF-1 were not affected by the administration of STG. Real‑time PCR analysis revealed that colonic mucosal IL-6 mRNA expression, which was significantly upregulated in the ob/ob mice, was significantly suppressed by the long-term administration of STG. These results suggest that a DPP-4 inhibitor may suppress colon carcinogenesis in mice with type 2 diabetes in a GLP-independent manner. Since DPP-4 has multiple biological functions, further studies analyzing other factors related to colon carcinogenesis are needed. PMID:26573958

  17. Pharmacologic suppression of MITF expression via HDAC inhibitors in the melanocyte lineage

    PubMed Central

    Yokoyama, Satoru; Feige, Erez; Poling, Laura L.; Levy, Carmit; Widlund, Hans R.; Khaled, Mehdi; Kung, Andrew L.; Fisher, David E.

    2013-01-01

    Summary Melanoma incidence continues to rise at an alarming rate while effective systemic therapies remain very limited. Microphthalmia-associated transcription factor (MITF) is required for development of melanocytes and is an amplified oncogene in a fraction of human melanomas. MITF also plays an oncogenic role in human clear cell sarcomas, which typically exhibit melanoma-like features. Although pharmacologic suppression of MITF is of potential interest in a variety of clinical settings, it is not known to contain intrinsic catalytic activity capable of direct small molecule inhibition. An alternative drug-targeting strategy is to identify and interfere with lineage-restricted mechanisms required for its expression. Here, we report that multiple HDAC-inhibitor drugs potently suppress MITF expression in melanocytes, melanoma and clear cell sarcoma cells. Although HDAC inhibitors may affect numerous cellular targets, we observed suppression of skin pigmentation by topical drug application as well as evidence of anti-melanoma efficacy in vitro and in mouse xenografts. Consequently, HDAC inhibitor drugs are candidates to play therapeutic roles in targeting conditions affecting the melanocyte lineage. PMID:18627530

  18. Inhibitors of secreted phospholipase A2 suppress the release of PGE2 in renal mesangial cells.

    PubMed

    Vasilakaki, Sofia; Barbayianni, Efrosini; Magrioti, Victoria; Pastukhov, Oleksandr; Constantinou-Kokotou, Violetta; Huwiler, Andrea; Kokotos, George

    2016-07-01

    The upregulation of PGE2 by mesangial cells has been observed under chronic inflammation condition. In the present work, renal mesangial cells were stimulated to trigger a huge increase of PGE2 synthesis and were treated in the absence or presence of known PLA2 inhibitors. A variety of synthetic inhibitors, mainly developed in our labs, which are known to selectively inhibit each of GIVA cPLA2, GVIA iPLA2, and GIIA/GV sPLA2, were used as tools in this study. Synthetic sPLA2 inhibitors, such as GK115 (an amide derivative based on the non-natural amino acid (R)-γ-norleucine) as well as GK126 and GK241 (2-oxoamides based on the natural (S)-α-amino acid leucine and valine, respectively) presented an interesting effect on the suppression of PGE2 formation. PMID:27234891

  19. IDO1 suppresses inhibitor development in hemophilia A treated with factor VIII

    PubMed Central

    Matino, Davide; Gargaro, Marco; Santagostino, Elena; Di Minno, Matteo N.D.; Castaman, Giancarlo; Morfini, Massimo; Rocino, Angiola; Mancuso, Maria E.; Di Minno, Giovanni; Coppola, Antonio; Talesa, Vincenzo N.; Volpi, Claudia; Vacca, Carmine; Orabona, Ciriana; Iannitti, Rossana; Mazzucconi, Maria G.; Santoro, Cristina; Tosti, Antonella; Chiappalupi, Sara; Sorci, Guglielmo; Tagariello, Giuseppe; Belvini, Donata; Radossi, Paolo; Landolfi, Raffaele; Fuchs, Dietmar; Boon, Louis; Pirro, Matteo; Marchesini, Emanuela; Grohmann, Ursula; Puccetti, Paolo; Iorio, Alfonso; Fallarino, Francesca

    2015-01-01

    The development of inhibitory antibodies to factor VIII (FVIII) is a major obstacle in using this clotting factor to treat individuals with hemophilia A. Patients with a congenital absence of FVIII do not develop central tolerance to FVIII, and therefore, any control of their FVIII-reactive lymphocytes relies upon peripheral tolerance mechanisms. Indoleamine 2,3-dioxygenase 1 (IDO1) is a key regulatory enzyme that supports Treg function and peripheral tolerance in adult life. Here, we investigated the association between IDO1 competence and inhibitor status by evaluating hemophilia A patients harboring F8-null mutations that were either inhibitor negative (n = 50) or positive (n = 50). We analyzed IDO1 induction, expression, and function for any relationship with inhibitor occurrence by multivariable logistic regression and determined that defective TLR9-mediated activation of IDO1 induction is associated with an inhibitor-positive status. Evaluation of experimental hemophilic mouse models with or without functional IDO1 revealed that tryptophan metabolites, which result from IDO1 activity, prevent generation of anti-FVIII antibodies. Moreover, treatment of hemophilic animals with a TLR9 agonist suppressed FVIII-specific B cells by a mechanism that involves IDO1-dependent induction of Tregs. Together, these findings indicate that strategies aimed at improving IDO1 function should be further explored for preventing or eradicating inhibitors to therapeutically administered FVIII protein. PMID:26426076

  20. IDO1 suppresses inhibitor development in hemophilia A treated with factor VIII.

    PubMed

    Matino, Davide; Gargaro, Marco; Santagostino, Elena; Di Minno, Matteo N D; Castaman, Giancarlo; Morfini, Massimo; Rocino, Angiola; Mancuso, Maria E; Di Minno, Giovanni; Coppola, Antonio; Talesa, Vincenzo N; Volpi, Claudia; Vacca, Carmine; Orabona, Ciriana; Iannitti, Rossana; Mazzucconi, Maria G; Santoro, Cristina; Tosti, Antonella; Chiappalupi, Sara; Sorci, Guglielmo; Tagariello, Giuseppe; Belvini, Donata; Radossi, Paolo; Landolfi, Raffaele; Fuchs, Dietmar; Boon, Louis; Pirro, Matteo; Marchesini, Emanuela; Grohmann, Ursula; Puccetti, Paolo; Iorio, Alfonso; Fallarino, Francesca

    2015-10-01

    The development of inhibitory antibodies to factor VIII (FVIII) is a major obstacle in using this clotting factor to treat individuals with hemophilia A. Patients with a congenital absence of FVIII do not develop central tolerance to FVIII, and therefore, any control of their FVIII-reactive lymphocytes relies upon peripheral tolerance mechanisms. Indoleamine 2,3-dioxygenase 1 (IDO1) is a key regulatory enzyme that supports Treg function and peripheral tolerance in adult life. Here, we investigated the association between IDO1 competence and inhibitor status by evaluating hemophilia A patients harboring F8-null mutations that were either inhibitor negative (n = 50) or positive (n = 50). We analyzed IDO1 induction, expression, and function for any relationship with inhibitor occurrence by multivariable logistic regression and determined that defective TLR9-mediated activation of IDO1 induction is associated with an inhibitor-positive status. Evaluation of experimental hemophilic mouse models with or without functional IDO1 revealed that tryptophan metabolites, which result from IDO1 activity, prevent generation of anti-FVIII antibodies. Moreover, treatment of hemophilic animals with a TLR9 agonist suppressed FVIII-specific B cells by a mechanism that involves IDO1-dependent induction of Tregs. Together, these findings indicate that strategies aimed at improving IDO1 function should be further explored for preventing or eradicating inhibitors to therapeutically administered FVIII protein. PMID:26426076

  1. A Novel Malate Dehydrogenase 2 Inhibitor Suppresses Hypoxia-Inducible Factor-1 by Regulating Mitochondrial Respiration.

    PubMed

    Ban, Hyun Seung; Xu, Xuezhen; Jang, Kusik; Kim, Inhyub; Kim, Bo-Kyung; Lee, Kyeong; Won, Misun

    2016-01-01

    We previously reported that hypoxia-inducible factor (HIF)-1 inhibitor LW6, an aryloxyacetylamino benzoic acid derivative, inhibits malate dehydrogenase 2 (MDH2) activity during the mitochondrial tricarboxylic acid (TCA) cycle. In this study, we present a novel MDH2 inhibitor compound 7 containing benzohydrazide moiety, which was identified through structure-based virtual screening of chemical library. Similar to LW6, compound 7 inhibited MDH2 activity in a competitive fashion, thereby reducing NADH level. Consequently, compound 7 reduced oxygen consumption and ATP production during the mitochondrial respiration cycle, resulting in increased intracellular oxygen concentration. Therefore, compound 7 suppressed the accumulation of HIF-1α and expression of its target genes, vascular endothelial growth factor (VEGF) and glucose transporter 1 (GLUT1). Moreover, reduction in ATP content activated AMPK, thereby inactivating ACC and mTOR the downstream pathways. As expected, compound 7 exhibited significant growth inhibition of human colorectal cancer HCT116 cells. Compound 7 demonstrated substantial anti-tumor efficacy in an in vivo xenograft assay using HCT116 mouse model. Taken together, a novel MDH2 inhibitor, compound 7, suppressed HIF-1α accumulation via reduction of oxygen consumption and ATP production, integrating metabolism into anti-cancer efficacy in cancer cells. PMID:27611801

  2. Glycolytic inhibitor 2-deoxyglucose simultaneously targets cancer and endothelial cells to suppress neuroblastoma growth in mice

    PubMed Central

    Huang, Chao-Cheng; Wang, Shuo-Yu; Lin, Li-Ling; Wang, Pei-Wen; Chen, Ting-Ya; Hsu, Wen-Ming; Lin, Tsu-Kung; Liou, Chia-Wei; Chuang, Jiin-Haur

    2015-01-01

    ABSTRACT Neuroblastoma is characterized by a wide range of clinical manifestations and associated with poor prognosis when there is amplification of MYCN oncogene or high expression of Myc oncoproteins. In a previous in vitro study, we found that the glycolytic inhibitor 2-deoxyglucose (2DG) could suppress the growth of neuroblastoma cells, particularly in those with MYCN amplification. In this study, we established a mouse model of neuroblastoma xenografts with SK-N-DZ and SK-N-AS cells treated with 2DG by intraperitoneal injection twice a week for 3 weeks at 100 or 500 mg/kg body weight. We found that 2DG was effective in suppressing the growth of both MYCN-amplified SK-N-DZ and MYCN-non-amplified SK-N-AS neuroblastoma xenografts, which was associated with downregulation of HIF-1α, PDK1 and c-Myc, and a reduction in the number of tumor blood vessels. In vitro study showed that 2DG can suppress proliferation, cause apoptosis and reduce migration of murine endothelial cells, with inhibition of the formation of lamellipodia and filopodia and disorganization of F-actin filaments. The results suggest that 2DG might simultaneously target cancer cells and endothelial cells in the neuroblastoma xenografts in mice regardless of the status of MYCN amplification, providing a potential therapeutic opportunity to use 2DG or other glycolytic inhibitors for the treatment of patients with refractory neuroblastoma. PMID:26398947

  3. Neddylation inhibitor MLN4924 suppresses growth and migration of human gastric cancer cells.

    PubMed

    Lan, Huiyin; Tang, Zaiming; Jin, Hongchuan; Sun, Yi

    2016-01-01

    MLN4924 is a recently discovered small molecule inhibitor of NEDD8-Activating Enzyme (NAE). Because cullin RING ligase (CRL), the largest family of E3 ubiquitin ligase, requires cullin neddylation for its activity, MLN4924, therefore, acts as an indirect inhibitor of CRL by blocking cullin neddylation. Given that CRLs components are up-regulated, whereas neddylation modification is over-activated in a number of human cancers, MLN4924 was found to be effective in growth suppression of cancer cells. Whether MLN4924 is effective against gastric cancer cells, however, remains elusive. Here we showed that in gastric cancer cells, MLN4924 rapidly inhibited cullin 1 neddylation and remarkably suppressed growth and survival as well as migration in a dose-and time-dependent manner. Mechanistic studies in combination with siRNA knockdown-based rescue experiments revealed that MLN4924 induced the accumulation of a number of CRL substrates, including CDT1/ORC1, p21/p27, and PHLPP1 to trigger DNA damage response and induce growth arrest at the G2/M phase, to induce senescence, as well as autophagy, respectively. MLN4924 also significantly suppressed migration by transcriptionally activating E-cadherin and repressing MMP-9. Taken together, our study suggest that neddylation modification and CRL E3 ligase are attractive gastric cancer targets, and MLN4924 might be further developed as a potent therapeutic agent for the treatment of gastric cancer. PMID:27063292

  4. Neddylation inhibitor MLN4924 suppresses growth and migration of human gastric cancer cells

    PubMed Central

    Lan, Huiyin; Tang, Zaiming; Jin, Hongchuan; Sun, Yi

    2016-01-01

    MLN4924 is a recently discovered small molecule inhibitor of NEDD8-Activating Enzyme (NAE). Because cullin RING ligase (CRL), the largest family of E3 ubiquitin ligase, requires cullin neddylation for its activity, MLN4924, therefore, acts as an indirect inhibitor of CRL by blocking cullin neddylation. Given that CRLs components are up-regulated, whereas neddylation modification is over-activated in a number of human cancers, MLN4924 was found to be effective in growth suppression of cancer cells. Whether MLN4924 is effective against gastric cancer cells, however, remains elusive. Here we showed that in gastric cancer cells, MLN4924 rapidly inhibited cullin 1 neddylation and remarkably suppressed growth and survival as well as migration in a dose-and time-dependent manner. Mechanistic studies in combination with siRNA knockdown-based rescue experiments revealed that MLN4924 induced the accumulation of a number of CRL substrates, including CDT1/ORC1, p21/p27, and PHLPP1 to trigger DNA damage response and induce growth arrest at the G2/M phase, to induce senescence, as well as autophagy, respectively. MLN4924 also significantly suppressed migration by transcriptionally activating E-cadherin and repressing MMP-9. Taken together, our study suggest that neddylation modification and CRL E3 ligase are attractive gastric cancer targets, and MLN4924 might be further developed as a potent therapeutic agent for the treatment of gastric cancer. PMID:27063292

  5. The serotonin reuptake inhibitor citalopram suppresses activity in the neonatal rat barrel cortex in vivo.

    PubMed

    Akhmetshina, Dinara; Zakharov, Andrei; Vinokurova, Daria; Nasretdinov, Azat; Valeeva, Guzel; Khazipov, Roustem

    2016-06-01

    Inhibition of serotonin uptake, which causes an increase in extracellular serotonin levels, disrupts the development of thalamocortical barrel maps in neonatal rodents. Previous in vitro studies have suggested that the disruptive effect of excessive serotonin on barrel map formation involves a depression at thalamocortical synapses. However, the effects of serotonin uptake inhibitors on the early thalamocortical activity patterns in the developing barrel cortex in vivo remain largely unknown. Here, using extracellular recordings of the local field potentials and multiple unit activity (MUA) we explored the effects of the selective serotonin reuptake inhibitor (SSRI) citalopram (10-20mg/kg, intraperitoneally) on sensory evoked activity in the barrel cortex of neonatal (postnatal days P2-5) rats in vivo. We show that administration of citalopram suppresses the amplitude and prolongs the delay of the sensory evoked potentials, reduces the power and frequency of the early gamma oscillations, and suppresses sensory evoked and spontaneous neuronal firing. In the adolescent P21-29 animals, citalopram affected neither sensory evoked nor spontaneous activity in barrel cortex. We suggest that suppression of the early thalamocortical activity patterns contributes to the disruption of the barrel map development caused by SSRIs and other conditions elevating extracellular serotonin levels. PMID:27016034

  6. Aromatase inhibitor plus ovarian suppression as adjuvant therapy in premenopausal women with breast cancer

    PubMed Central

    Figg, William D; Cook, Katherine; Clarke, Robert

    2014-01-01

    The goal of adjuvant hormonal therapy for breast cancer is to prevent recurrence by eradicating micrometastatic disease. Recent studies have shown that the use of aromatase inhibitors (AIs) as adjuvant therapy improves outcomes for postmenopausal women with estrogen receptor (ER)-positive breast cancer compared to adjuvant endocrine therapy with tamoxifen alone. The research question has been raised whether AIs would have similar improvements in disease-free survival (DFS) in premenopausal women with ER-positive breast cancer. Combining 2 phase 3 clinical trials (n = 4,690), Pagani and colleagues randomized premenopausal women with ER-positive early breast cancer to exemestane plus ovarian suppression or tamoxifen plus ovarian suppression for a period of 5 y. After a median follow-up of 68 months, DFS was 91.1% in the AI group and 87.3% in the tamoxifen group. In premenopausal women with hormone-receptor-positive early breast cancer, adjuvant treatment with exemestane plus ovarian suppression, as compared with tamoxifen plus ovarian suppression, significantly reduced recurrence. PMID:25535893

  7. Suppression of lung metastases by the CD26/DPP4 inhibitor Vildagliptin in mice.

    PubMed

    Jang, Jae-Hwi; Baerts, Lesley; Waumans, Yannick; De Meester, Ingrid; Yamada, Yoshito; Limani, Perparim; Gil-Bazo, Ignacio; Weder, Walter; Jungraithmayr, Wolfgang

    2015-10-01

    Metastases rather than primary cancers determine nowadays the survival of patients. One of the most common primary malignancies is colorectal cancer and this type of tumor is characterized by a high tendency to spread metastases to the lung and liver. CD26/DPP4 is a transmembrane molecule with enzymatic functions which cleaves biologically active peptides. Recently, CD26/DPP4 has become the focus of cancer research and it was shown that CD26/DPP4-positive cancer cells display increased metastatic activity. Here, we tested if the CD26/DPP4-inhibitor Vildagliptin suppresses the development and growth of mouse colorectal lung metastases. This inhibitor of CD26/DPP4 was employed on mouse (C57BL/6) colorectal lung metastases, established by intravenous injection of the syngeneic cell line MC38. For mechanistic analysis, a subcutaneous tumor model was used. The treatment with Vildagliptin significantly suppressed both, the incidence and growth of lung metastases. Autophagy markers (LC3, p62, and ATF4) decreased, apoptosis increased (TUNEL, pH3/Ki-76), and the cell cycle regulator pCDC2 was inhibited. In conclusion, we here showed an anti-tumor effect of Vildagliptin via downregulation of autophagy resulting in increased apoptosis and modulation of the cell cycle. We therefore propose Vildagliptin for the evaluation as a new therapeutic approach for the treatment of colorectal cancer lung metastases. PMID:26233333

  8. The novel combination of dual mTOR inhibitor AZD2014 and pan-PIM inhibitor AZD1208 inhibits growth in acute myeloid leukemia via HSF pathway suppression

    PubMed Central

    Yamamoto, Shinichi; Kaur, Surinder; Arslan, Dirim; Ramirez, Santiago; Jacamo, Rodrigo; Platanias, Leonidas; Matsushita, Hiromichi; Fujimura, Tsutomu; Kazuno, Saiko; Kojima, Kensuke; Tabe, Yoko; Konopleva, Marina

    2015-01-01

    Mammalian target of rapamycin (mTOR) signaling is a critical pathway in the biology of acute myeloid leukemia (AML). Proviral integration site for moloney murine leukemia virus (PIM) serine/threonine kinase signaling takes part in various pathways exerting tumorigenic properties. We hypothesized that the combination of a PIM kinase inhibitor with an mTOR inhibitor might have complementary growth-inhibitory effects against AML. The simultaneous inhibition of the PIM kinase by pan-PIM inhibitor AZD1208 and of mTOR by selective mTORC1/2 dual inhibitor AZD2014 exerted anticancer properties in AML cell lines and in cells derived from primary AML samples with or without supportive stromal cell co-culture, leading to suppressed proliferation and increased apoptosis. The combination of AZD1208 and AZD2014 rapidly activated AMPKα, a negative regulator of translation machinery through mTORC1/2 signaling in AML cells; profoundly inhibited AKT and 4EBP1 activation; and suppressed polysome formation. Inhibition of both mTOR and PIM counteracted induction of heat-shock family proteins, uncovering the master negative regulation of heat shock factor 1 (HSF1), the dominant transcription factor controlling cellular stress responses. The novel combination of the dual mTOR inhibitor and pan-PIM inhibitor synergistically inhibited AML growth by effectively reducing protein synthesis through heat shock factor pathway suppression. PMID:26473447

  9. Suppression of VEGF-induced angiogenesis by the protein tyrosine kinase inhibitor, lavendustin A.

    PubMed Central

    Hu, D E; Fan, T P

    1995-01-01

    1. Vascular endothelial growth factor (VEGF) is a heparin-binding angiogenic factor which specifically acts on endothelial cells via distinct membrane-spanning tyrosine kinase receptors. Here we used the rat sponge implant model to test the hypothesis that the angiogenic activity of VEGF can be suppressed by protein tyrosine kinase (PTK) inhibitors. 2. Neovascular responses in subcutaneous sponge implants were determined by measurements of relative sponge blood flow by use of a 133Xe clearance technique, and confirmed by histological studies and morphometric analysis. 3. Daily local administration of 250 ng VEGF165 accelerated the rate of 133Xe clearance from the sponges and induced an intense neovascularisation. This VEGF165-induced angiogenesis was inhibited by daily co-administration of the selective PTK inhibitor, lavendustin A (10 micrograms), but not its negative control, lavendustin B (10 micrograms). Blood flow measurements and morphometric analysis of 8-day-old sponges showed that lavendustin A reduced the 133Xe clearance of VEGF165-treated sponges from 32.9 +/- 1.5% to 20.9 +/- 1.6% and the total fibrovascular growth area from 62.4 +/- 6.1% to 21.6 +/- 6.8% (n = 12, P < 0.05). 4. Co-injection of suramin (3 mg), an inhibitor of heparin-binding growth factors, also suppressed the VEGF165-elicited neovascular response. In contrast, neither lavendustin A nor suramin produced any effect on the basal sponge-induced angiogenesis. 5. When given alone, low doses of VEGF165 (25 ng) or basic fibroblast growth factor (bFGF; 10 ng) did not modify the basal sponge-induced neovascularisation.(ABSTRACT TRUNCATED AT 250 WORDS) Images Figure 2 Figure 2 PMID:7533611

  10. Histone Deacetylase Inhibitors Antagonize Distinct Pathways to Suppress Tumorigenesis of Embryonal Rhabdomyosarcoma

    PubMed Central

    Vleeshouwer-Neumann, Terra; Phelps, Michael; Bammler, Theo K.; MacDonald, James W.; Jenkins, Isaac; Chen, Eleanor Y.

    2015-01-01

    Embryonal rhabdomyosarcoma (ERMS) is the most common soft tissue cancer in children. The prognosis of patients with relapsed or metastatic disease remains poor. ERMS genomes show few recurrent mutations, suggesting that other molecular mechanisms such as epigenetic regulation might play a major role in driving ERMS tumor biology. In this study, we have demonstrated the diverse roles of histone deacetylases (HDACs) in the pathogenesis of ERMS by characterizing effects of HDAC inhibitors, trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA; also known as vorinostat) in vitro and in vivo. TSA and SAHA suppress ERMS tumor growth and progression by inducing myogenic differentiation as well as reducing the self-renewal and migratory capacity of ERMS cells. Differential expression profiling and pathway analysis revealed downregulation of key oncogenic pathways upon HDAC inhibitor treatment. By gain-of-function, loss-of-function, and chromatin immunoprecipitation (ChIP) studies, we show that Notch1- and EphrinB1-mediated pathways are regulated by HDACs to inhibit differentiation and enhance migratory capacity of ERMS cells, respectively. Our study demonstrates that aberrant HDAC activity plays a major role in ERMS pathogenesis. Druggable targets in the molecular pathways affected by HDAC inhibitors represent novel therapeutic options for ERMS patients. PMID:26636678

  11. Combination of PIM and JAK2 inhibitors synergistically suppresses cell proliferation and overcomes drug resistance of myeloproliferative neoplasms

    PubMed Central

    Greco, Rita; Li, Zhifang; Sun, Fangxian; Barberis, Claude; Tabart, Michel; Patel, Vinod; Schio, Laurent; Hurley, Raelene; Chen, Bo; Cheng, Hong; Lengauer, Christoph; Pollard, Jack; Watters, James; Garcia-Echeverria, Carlos; Wiederschain, Dmitri; Adrian, Francisco; Zhang, JingXin

    2014-01-01

    Inhibitors of JAK2 kinase are emerging as an important treatment modality for myeloproliferative neoplasms (MPN). However, similar to other kinase inhibitors, resistance to JAK2 inhibitors may eventually emerge through a variety of mechanisms. Effective drug combination is one way to enhance therapeutic efficacy and combat resistance against JAK2 inhibitors. To identify potential combination partners for JAK2 compounds in MPN cell lines, we performed pooled shRNA screen targeting 5,000 genes in the presence or absence of JAK2 blockade. One of the top hits identified was MYC, an oncogenic transcription factor that is difficult to inhibit directly, but could be targeted by modulation of upstream regulatory elements such as kinases. We demonstrate herein that PIM kinase inhibitors efficiently suppress MYC protein levels in MPN cell lines. Overexpression of MYC restores the viability of PIM inhibitor-treated cells, revealing causal relationship between MYC down-regulation and cell growth inhibition by PIM compounds. Combination of various PIM inhibitors with a JAK2 inhibitor results in significant synergistic growth inhibition of multiple MPN cancer cell lines and induction of apoptosis. Mechanistic studies revealed strong downregulation of phosphorylated forms of S6 and 4EBP1 by JAK2/PIM inhibitor combination treatment. Finally, such combination was effective in eradicating in vitro JAK2 inhibitor-resistant MPN clones, where MYC is consistently up-regulated. These findings demonstrate that simultaneous suppression of JAK2 and PIM kinase activity by small molecule inhibitors is more effective than either agent alone in suppressing MPN cell growth. Our data suggest that JAK2 and PIM combination might warrant further investigation for the treatment of JAK2-driven hematologic malignancies. PMID:24830942

  12. Integrin α7 Binds Tissue Inhibitor of Metalloproteinase 3 to Suppress Growth of Prostate Cancer Cells

    PubMed Central

    Tan, Lang-Zhu; Song, Yang; Nelson, Joel; Yu, Yan P.; Luo, Jian-Hua

    2014-01-01

    Integrin α7 (ITGA7) is a tumor-suppressor gene that is critical for suppressing the growth of malignant tumors; however, the mechanisms allowing ITGA7 to suppress the growth of cancer cells remain unclear. Herein, we show that ITGA7 binds to tissue inhibitor of metalloproteinase 3 (TIMP3) in prostate cancer cells. The ITGA7-TIMP3 binding led to a decreased protein level of tumor necrosis factor α, cytoplasmic translocation of NF-κB, and down-regulation of cyclin D1. These changes led to an accumulation of cells in G0/G1 and a dramatic suppression of cell growth. Knocking down TIMP3 or ITGA7/TIMP3 binding interference largely abrogated the signaling changes induced by ITGA7, whereas a mutant ITGA7 lacking TIMP3 binding activity had no tumor-suppressor activity. Interestingly, knocking down ITGA7 ligand laminin β1 enhanced ITGA7-TIMP3 signaling and the downstream tumor-suppressor activity, suggesting the existence of a counterbalancing role between extracellular matrix and integrin signaling. As a result, this report demonstrates a novel and critical signaling mechanism of ITGA7, through the TIMP3/NF-κB/cyclin D1 pathway. PMID:23830872

  13. Suppression of chlorinated aromatics by nitrogen and sulphur inhibitors in iron ore sintering.

    PubMed

    Zhang, Yadi; Buekens, Alfons; Liu, Lina; Zhang, Yibo; Zeng, Xiaolan; Sun, Yifei

    2016-07-01

    Dioxins generated by iron and steel industry account for the majority of industrial dioxins emissions. This study compares the performance of different additives (including calcium sulphate dehydrate CaSO4·2H2O; calcium polysulphide CaSx; ammonium sulphate (NH4)2SO4; 4-methylthiosemicarbazide H3C-SC(NH)2NH2 and thiourea H2NCSNH2) as suppressant of chlorinated aromatics in iron ore sintering. The formation of chlorobenzenes (CBz) and polychlorinated biphenyls (PCBs), used as surrogates for dioxins, was suppressed significantly in the present of various inhibitors (1 wt%) except for CaSO4·2H2O. Moreover, a larger molar ratio of (S + N)/Cl leads to a higher suppression efficiency, so that the inhibition capacity of (NH4)2SO4 on both CBz and PCBs was weaker than H2NCSNH2. The generation of dioxin-like PCBs (Co- or dl-PCB) was also analysed. PMID:27131450

  14. A small-molecule inhibitor of sarcomere contractility suppresses hypertrophic cardiomyopathy in mice

    PubMed Central

    Green, Eric M.; Wakimoto, Hiroko; Anderson, Robert L.; Evanchik, Marc J.; Gorham, Joshua M.; Harrison, Brooke C.; Henze, Marcus; Kawas, Raja; Oslob, Johan D.; Rodriguez, Hector M.; Song, Yonghong; Wan, William; Leinwand, Leslie A.; Spudich, James A.; McDowell, Robert S.; Seidman, J. G.; Seidman, Christine E.

    2016-01-01

    Hypertrophic cardiomyopathy (HCM) is an inherited disease of heart muscle that can be caused by mutations in sarcomere proteins. Clinical diagnosis depends on an abnormal thickening of the heart, but the earliest signs of disease are hyperdynamic contraction and impaired relaxation. Whereas some in vitro studies of power generation by mutant and wild-type sarcomere proteins are consistent with mutant sarcomeres exhibiting enhanced contractile power, others are not. We identified a small molecule, MYK-461, that reduces contractility by decreasing the adenosine triphosphatase activity of the cardiac myosin heavy chain. Here we demonstrate that early, chronic administration of MYK-461 suppresses the development of ventricular hypertrophy, cardiomyocyte disarray, and myocardial fibrosis and attenuates hypertrophic and profibrotic gene expression in mice harboring heterozygous human mutations in the myosin heavy chain. These data indicate that hyperdynamic contraction is essential for HCM pathobiology and that inhibitors of sarcomere contraction may be a valuable therapeutic approach for HCM. PMID:26912705

  15. A small-molecule inhibitor of sarcomere contractility suppresses hypertrophic cardiomyopathy in mice.

    PubMed

    Green, Eric M; Wakimoto, Hiroko; Anderson, Robert L; Evanchik, Marc J; Gorham, Joshua M; Harrison, Brooke C; Henze, Marcus; Kawas, Raja; Oslob, Johan D; Rodriguez, Hector M; Song, Yonghong; Wan, William; Leinwand, Leslie A; Spudich, James A; McDowell, Robert S; Seidman, J G; Seidman, Christine E

    2016-02-01

    Hypertrophic cardiomyopathy (HCM) is an inherited disease of heart muscle that can be caused by mutations in sarcomere proteins. Clinical diagnosis depends on an abnormal thickening of the heart, but the earliest signs of disease are hyperdynamic contraction and impaired relaxation. Whereas some in vitro studies of power generation by mutant and wild-type sarcomere proteins are consistent with mutant sarcomeres exhibiting enhanced contractile power, others are not. We identified a small molecule, MYK-461, that reduces contractility by decreasing the adenosine triphosphatase activity of the cardiac myosin heavy chain. Here we demonstrate that early, chronic administration of MYK-461 suppresses the development of ventricular hypertrophy, cardiomyocyte disarray, and myocardial fibrosis and attenuates hypertrophic and profibrotic gene expression in mice harboring heterozygous human mutations in the myosin heavy chain. These data indicate that hyperdynamic contraction is essential for HCM pathobiology and that inhibitors of sarcomere contraction may be a valuable therapeutic approach for HCM. PMID:26912705

  16. Activated Drosophila Ras1 is selectively suppressed by isoprenyl transferase inhibitors.

    PubMed Central

    Kauffmann, R C; Qian, Y; Vogt, A; Sebti, S M; Hamilton, A D; Carthew, R W

    1995-01-01

    Ras CAAX (C = cysteine, A = aliphatic amino acid, and X = any amino acid) peptidomimetic inhibitors of farnesyl protein transferase suppress Ras-dependent cell transformation by preventing farnesylation of the Ras oncoprotein. These compounds are potential anticancer agents for tumors associated with Ras mutations. The peptidomimetic FTI-254 was tested for Ras1-inhibiting activity in whole animals by injection of activated Ras1val12 Drosophila larvae. FTI-254 decreased the ability of Ras1val12 to form supernumerary R7 photoreceptor cells in the compound eye of transformed flies. In contrast, it had no effect on the related supernumerary R7 phenotypes of flies transformed with either the activated sevenless receptor tyrosine kinase, Raf kinase, or a chimeric Ras1val12 protein that is membrane associated through myristylation instead of isoprenylation. Therefore, FTI-254 acts as an isoprenylation inhibitor to selectively inhibit Ras1val12 signaling activity in a whole-animal model system. Images Fig. 2 PMID:7479910

  17. Linker-Region Modified Derivatives of the Deoxyhypusine Synthase Inhibitor CNI-1493 Suppress HIV-1 Replication.

    PubMed

    Schröder, Marcus; Kolodzik, Adrian; Windshügel, Björn; Krepstakies, Marcel; Priyadarshini, Poornima; Hartjen, Philip; van Lunzen, Jan; Rarey, Matthias; Hauber, Joachim; Meier, Chris

    2016-02-01

    The inhibition of cellular factors that are involved in viral replication may be an important alternative to the commonly used strategy of targeting viral enzymes. The guanylhydrazone CNI-1493, a potent inhibitor of the deoxyhypusine synthase (DHS), prevents the activation of the cellular factor eIF-5A and thereby suppresses HIV replication and a number of other diseases. Here, we report on the design, synthesis and biological evaluation of a series of CNI-1493 analogues. The sebacoyl linker in CNI-1493 was replaced by different alkyl or aryl dicarboxylic acids. Most of the tested derivatives suppress HIV-1 replication efficiently in a dose-dependent manner without showing toxic side effects. The unexpected antiviral activity of the rigid derivatives point to a second binding mode as previously assumed for CNI-1493. Moreover, the chemical stability of CNI-1493 was analysed, showing a successive hydrolysis of the imino bonds. By molecular dynamics simulations, the behaviour of the parent CNI-1493 in solution and its interactions with DHS were investigated. PMID:26725082

  18. The p53 inhibitor, pifithrin-{alpha}, suppresses self-renewal of embryonic stem cells

    SciTech Connect

    Abdelalim, Essam Mohamed; Tooyama, Ikuo

    2012-04-13

    Highlights: Black-Right-Pointing-Pointer We determine the role of p53 in ES cells under unstressful conditions. Black-Right-Pointing-Pointer PFT-{alpha} suppresses ES cell proliferation. Black-Right-Pointing-Pointer PFT-{alpha} induces ES cell cycle arrest. Black-Right-Pointing-Pointer PFT-{alpha} downregulates Nanog and cyclin D1. -- Abstract: Recent studies have reported the role of p53 in suppressing the pluripotency of embryonic stem (ES) cells after DNA damage and blocking the reprogramming of somatic cells into induced pluripotent stem (iPS) cells. However, to date no evidence has been presented to support the function of p53 in unstressed ES cells. In this study, we investigated the effect of pifithrin (PFT)-{alpha}, an inhibitor of p53-dependent transcriptional activation, on self-renewal of ES cells. Our results revealed that treatment of ES cells with PFT-{alpha} resulted in the inhibition of ES cell propagation in a dose-dependent manner, as indicated by a marked reduction in the cell number and colony size. Also, PFT-{alpha} caused a cell cycle arrest and significant reduction in DNA synthesis. In addition, inhibition of p53 activity reduced the expression levels of cyclin D1 and Nanog. These findings indicate that p53 pathway in ES cells rather than acting as an inactive gene, is required for ES cell proliferation and self-renewal under unstressful conditions.

  19. AKT inhibitor suppresses hyperthermia-induced Ndrg2 phosphorylation in gastric cancer cells

    PubMed Central

    Tao, Yurong; Guo, Yan; Liu, Wenchao; Zhang, Jian; Li, Xia; Shen, Lan; Ru, Yi; Xue, Yan; Zheng, Jin; Liu, Xinping; Zhang, Jing; Yao, Libo

    2013-01-01

    Hyperthermia is one of the most effective adjuvant treatments for various cancers with few side effects. However, the underlying molecular mechanisms still are not known. N-myc downstream-regulated gene 2 (NDRG2), a tumor suppressor, has been shown to be involved in diverse cellular stresses including hypoxia, lipotoxicity, etc. In addition, Ndrg2 has been reported to be related to progression of gastric cancer. In the current study, our data showed that the apoptosis rate of MKN28 cells increased relatively rapidly to 13.4% by 24 h after treatment with hyperthermia (42°C for 1 h) compared to 5.1% in control cells (P < 0.05). Nevertheless, there was no obvious change in the expression level of total Ndrg2 during this process. Further investigation demonstrated that the relative phosphorylation levels of Ndrg2 at Ser332, Thr348 increased up to 3.2- and 1.9-fold (hyperthermia group vs control group) at 3 h in MKN28 cells, respectively (P < 0.05). We also found that heat treatment significantly increased AKT phosphorylation. AKT inhibitor VIII (10 µM) decreased the phosphorylation level of Ndrg2 induced by hyperthermia. Accordingly, the apoptosis rate rose significantly in MKN28 cells (16.4%) treated with a combination of AKT inhibitor VIII and hyperthermia compared to that (6.8%) of cells treated with hyperthermia alone (P < 0.05). Taken together, these data demonstrated that Ndrg2 phosphorylation could be induced by hyperthermia in an AKT-dependent manner in gastric cancer cells. Furthermore, AKT inhibitor VIII suppressed Ndrg2 phosphorylation and rendered gastric cancer cells susceptible to apoptosis induced by hyperthermia. PMID:23558861

  20. The Novel ATP-Competitive MEK/Aurora Kinase Inhibitor BI-847325 Overcomes Acquired BRAF Inhibitor Resistance through Suppression of Mcl-1 and MEK Expression.

    PubMed

    Phadke, Manali S; Sini, Patrizia; Smalley, Keiran S M

    2015-06-01

    Resistance to BRAF inhibitors is a major clinical problem. Here, we evaluate BI-847325, an ATP-competitive inhibitor of MEK and Aurora kinases, in treatment-naïve and drug-resistant BRAF-mutant melanoma models. BI-847325 potently inhibited growth and survival of melanoma cell lines that were both BRAF inhibitor naïve and resistant in 2D culture, 3D cell culture conditions, and in colony formation assays. Western blot studies showed BI-847325 to reduce expression of phospho-ERK and phospho-histone 3 in multiple models of vemurafenib resistance. Mechanistically, BI-847325 decreased the expression of MEK and Mcl-1 while increasing the expression of the proapoptotic protein BIM. Strong suppression of MEK expression was observed after 48 hours of treatment, with no recovery following >72 hours of washout. siRNA-mediated knockdown of Mcl-1 enhanced the effects of BI-847325, whereas Mcl-1 overexpression reversed this in both 2D cell culture and 3D spheroid melanoma models. In vivo, once weekly BI-847325 (70 mg/kg) led to durable regression of BRAF-inhibitor naïve xenografts with no regrowth seen (>65 days of treatment). In contrast, treatment with the vemurafenib analog PLX4720 was associated with tumor relapse at >30 days. BI-847325 also suppressed the long-term growth of xenografts with acquired PLX4720 resistance. Analysis of tumor samples revealed BI-847325 to induce apoptosis associated with suppression of phospho-ERK, total MEK, phospho-Histone3, and Mcl-1 expression. Our studies indicate that BI-847325 is effective in overcoming BRAF inhibitor resistance and has long-term inhibitory effects upon BRAF-mutant melanoma in vivo, through a mechanism associated with the decreased expression of both MEK and Mcl-1. PMID:25873592

  1. The novel ATP-competitive MEK/Aurora kinase inhibitor BI-847325 overcomes acquired BRAF inhibitor resistance through suppression of Mcl-1 and MEK expression

    PubMed Central

    Phadke, Manali S.; Sini, Patrizia; Smalley, Keiran S. M.

    2015-01-01

    Resistance to BRAF inhibitors is a major clinical problem. Here we evaluate BI-847325, an ATP-competitive inhibitor of MEK and Aurora kinases, in treatment-naïve and drug-resistant BRAF-mutant melanoma models. BI-847325 potently inhibited growth and survival of melanoma cell lines that were both BRAF inhibitor naïve and resistant in 2D culture, 3D cell culture conditions and in colony formation assays. Western blot studies showed BI-847325 to reduce expression of phospho-ERK and phospho-histone 3 in multiple models of vemurafenib resistance. Mechanistically, BI-847325 decreased the expression of MEK and Mcl-1 while increasing the expression of the pro-apoptotic protein BIM. Strong suppression of MEK expression was observed after 48 h of treatment, with no recovery following >72 h of washout. siRNA mediated knockdown of Mcl-1 enhanced the effects of BI-847325, whereas Mcl-1 overexpression reversed this in both 2D cell culture and 3D spheroid melanoma models. In vivo, once weekly BI-847325 (70 mg/kg) led to durable regression of BRAF-inhibitor naive xenografts with no regrowth seen (>65 days of treatment). In contrast, treatment with the vemurafenib analog PLX4720 was associated with tumor relapse at >30 days. BI-847325 also suppressed the long-term growth of xenografts with acquired PLX4720 resistance. Analysis of tumor samples revealed BI-847325 to induce apoptosis associated with suppression of phospho-ERK, total MEK, phospho-Histone3 and Mcl-1 expression. Our studies indicate that BI-847325 is effective in overcoming BRAF inhibitor resistance and has long-term inhibitory effects upon BRAF-mutant melanoma in vivo, through a mechanism associated with the decreased expression of both MEK and Mcl-1. PMID:25873592

  2. Met tyrosine kinase inhibitor, PF-2341066, suppresses growth and invasion of nasopharyngeal carcinoma

    PubMed Central

    Zhao, Yuanyuan; Zhang, Jing; Tian, Ying; Xue, Cong; Hu, Zhihuang; Zhang, Li

    2015-01-01

    Purpose We explored the effect of hepatocyte growth factor (HGF)/Met signaling pathway on nasopharyngeal carcinoma (NPC) cells in vitro and in vivo, and investigated the ability of Met tyrosine kinase inhibitor (TKI) to block HGF-induced biological signaling. Experimental design Met TKI inhibitor PF-2341066 alone, or in combination with cisplatin, was investigated for its ability to block HGF-induced signaling and biological effects in vitro and in vivo. HGF/Met expression and activation of signaling in NPC cells were detected by using Western blot and immunohistochemistry. Biological evaluation, including wound healing, cell proliferation, and invasion of NPC cells, was also examined, and the correlation between HGF/Met expression of primary and metastatic tumor in NPC patients and clinical prognosis were also analyzed. Results Met TKI inhibitor, PF-2341066, inhibited growth of NPC cells in vivo with half maximal inhibitory concentration of 0.79±0.21 μmol/L, and suppressed invasion and migration of NPC cells; also, the inhibition of PF-2341066 was synergized with cisplatin treatment. Compared with the control group, Met TKI inhibited metastasis of transplanted NPC in nude mice (the number of live metastases [mean ± SD]: 5.8±2.2 versus 11.8±2.2, P=0.03; the number of lung metastases: 2.3±1.5 versus 5.3±0.9, P=0.06). HGF was widely expressed in both primary and metastatic lesions while Met expression of metastatic lesions was higher than that of primary lesions (primary lesions: 24.7%; liver metastases: 40%; lung metastases: 29%; lymph node metastases: 29%, P<0.05), and overall survival of NPC patients with higher expression of Met was shorter (P=0.13). Conclusion Our results demonstrated that HGF/Met signaling promoted NPC growth, further resulting in metastasis and poor prognosis. Met TKI, PF-2341066, showed potent antitumor activity in vivo and in vitro which was enhanced by combination with cisplatin. Our study implied that HGF/Met signaling was the

  3. Nucleoside Reverse Transcriptase Inhibitors Suppress Laser-Induced Choroidal Neovascularization in Mice

    PubMed Central

    Mizutani, Takeshi; Fowler, Benjamin J.; Kim, Younghee; Yasuma, Reo; Krueger, Laura A.; Gelfand, Bradley D.; Ambati, Jayakrishna

    2015-01-01

    Purpose To evaluate the efficacy of nucleoside reverse transcriptase inhibitors (NRTIs) in the laser-induced mouse model of choroidal neovascularization (CNV). Methods We evaluated the NRTIs lamivudine (3TC), zidovudine (AZT), and abacavir (ABC) and the P2X7 antagonist A438079. Choroidal neovascularization was induced by laser injury in C57BL/6J wild-type, Nlrp3−/−, and P2rx7−/− mice, and CNV volume was measured after 7 days by confocal microscopy. Drugs were administered by intravitreous injection immediately after the laser injury. Vascular endothelial growth factor-A in RPE-choroid lysates was measured 3 days after laser injury by ELISA. HEK293 cells expressing human and mouse P2X7 were exposed to the selective P2X7 receptor agonist 2′, 3′-(benzoyl-4-benzoyl)-ATP (Bz-ATP) with or without 3TC, and VEGF-A levels in media were measured by ELISA. Results Intravitreous injection of 3TC, AZT, and ABC significantly suppressed laser-induced CNV in C57BL/6J wild-type and Nlrp3−/− mice (P < 0.05) but not in P2rx7−/− mice. Intravitreous injection of A438079 also suppressed the laser-induced CNV (P < 0.05). The NRTIs 3TC, AZT, and ABC blocked VEGF-A levels in the RPE/choroid after laser injury in wild-type (P < 0.05) but not P2rx7−/− mice. Moreover, there was no additive effect of 3TC on CNV inhibition when coadministered with a neutralizing VEGF-A antibody. Stimulation of human and mouse P2X7-expressing HEK293 cells with Bz-ATP increased VEGF secretion (P < 0.001), which was abrogated by 3TC (P < 0.001). Stimulation of primary human RPE cells with Bz-ATP increased VEGFA and IL6 mRNA levels, which were abrogated by 3TC. Conclusions Multiple clinically relevant NRTIs suppressed laser-induced CNV and downregulated VEGF-A, via P2X7. PMID:26529046

  4. PARP Inhibitor PJ34 Suppresses Osteogenic Differentiation in Mouse Mesenchymal Stem Cells by Modulating BMP-2 Signaling Pathway

    PubMed Central

    Kishi, Yuta; Fujihara, Hisako; Kawaguchi, Koji; Yamada, Hiroyuki; Nakayama, Ryoko; Yamamoto, Nanami; Fujihara, Yuko; Hamada, Yoshiki; Satomura, Kazuhito; Masutani, Mitsuko

    2015-01-01

    Poly(ADP-ribosyl)ation is known to be involved in a variety of cellular processes, such as DNA repair, cell death, telomere regulation, genomic stability and cell differentiation by poly(ADP-ribose) polymerase (PARP). While PARP inhibitors are presently under clinical investigation for cancer therapy, little is known about their side effects. However, PARP involvement in mesenchymal stem cell (MSC) differentiation potentiates MSC-related side effects arising from PARP inhibition. In this study, effects of PARP inhibitors on MSCs were examined. MSCs demonstrated suppressed osteogenic differentiation after 1 µM PJ34 treatment without cytotoxicity, while differentiation of MSCs into chondrocytes or adipocytes was unaffected. PJ34 suppressed mRNA induction of osteogenic markers, such as Runx2, Osterix, Bone Morphogenetic Protein-2, Osteocalcin, bone sialoprotein, and Osteopontin, and protein levels of Bone Morphogenetic Protein-2, Osterix and Osteocalcin. PJ34 treatment also inhibited transcription factor regulators such as Smad1, Smad4, Smad5 and Smad8. Extracellular mineralized matrix formation was also diminished. These results strongly suggest that PARP inhibitors are capable of suppressing osteogenic differentiation and poly(ADP-ribosyl)ation may play a physiological role in this process through regulation of BMP-2 signaling. Therefore, PARP inhibition may potentially attenuate osteogenic metabolism, implicating cautious use of PARP inhibitors for cancer treatments and monitoring of patient bone metabolism levels. PMID:26492236

  5. PARP Inhibitor PJ34 Suppresses Osteogenic Differentiation in Mouse Mesenchymal Stem Cells by Modulating BMP-2 Signaling Pathway.

    PubMed

    Kishi, Yuta; Fujihara, Hisako; Kawaguchi, Koji; Yamada, Hiroyuki; Nakayama, Ryoko; Yamamoto, Nanami; Fujihara, Yuko; Hamada, Yoshiki; Satomura, Kazuhito; Masutani, Mitsuko

    2015-01-01

    Poly(ADP-ribosyl)ation is known to be involved in a variety of cellular processes, such as DNA repair, cell death, telomere regulation, genomic stability and cell differentiation by poly(ADP-ribose) polymerase (PARP). While PARP inhibitors are presently under clinical investigation for cancer therapy, little is known about their side effects. However, PARP involvement in mesenchymal stem cell (MSC) differentiation potentiates MSC-related side effects arising from PARP inhibition. In this study, effects of PARP inhibitors on MSCs were examined. MSCs demonstrated suppressed osteogenic differentiation after 1 µM PJ34 treatment without cytotoxicity, while differentiation of MSCs into chondrocytes or adipocytes was unaffected. PJ34 suppressed mRNA induction of osteogenic markers, such as Runx2, Osterix, Bone Morphogenetic Protein-2, Osteocalcin, bone sialoprotein, and Osteopontin, and protein levels of Bone Morphogenetic Protein-2, Osterix and Osteocalcin. PJ34 treatment also inhibited transcription factor regulators such as Smad1, Smad4, Smad5 and Smad8. Extracellular mineralized matrix formation was also diminished. These results strongly suggest that PARP inhibitors are capable of suppressing osteogenic differentiation and poly(ADP-ribosyl)ation may play a physiological role in this process through regulation of BMP-2 signaling. Therefore, PARP inhibition may potentially attenuate osteogenic metabolism, implicating cautious use of PARP inhibitors for cancer treatments and monitoring of patient bone metabolism levels. PMID:26492236

  6. Purvalanol A, a CDK inhibitor, effectively suppresses Src-mediated transformation by inhibiting both CDKs and c-Src.

    PubMed

    Hikita, Tomoya; Oneyama, Chitose; Okada, Masato

    2010-10-01

    The nonreceptor tyrosine kinase c-Src is frequently over-expressed or hyperactivated in various human cancers and contributes to cancer progression in cooperation with up-regulated growth factor receptors. However, Src-selective anticancer drugs are still in clinical trials. To identify more effective inhibitors of c-Src-mediated cancer progression, we developed a new screening platform using Csk-deficient cells that can be transformed by c-Src. We found that purvalanol A, developed as a CDK inhibitor, potently suppressed the anchorage-independent growth of c-Src-transformed cells, indicating that the activation of CDKs contributes to the c-Src transformation. We also found that purvalanol A suppressed the c-Src activity as effectively as the Src-selective inhibitor PP2, and that it reverted the transformed morphology to a nearly normal shape with less cytotoxicity than PP2. Purvalanol A induced a strong G2-M arrest, whereas PP2 weakly acted on the G1-S transition. Furthermore, when compared with PP2, purvalanol A more effectively suppressed the growth of human colon cancer HT29 and SW480 cells, in which Src family kinases and CDKs are activated. These findings demonstrate that the coordinated inhibition of cell cycle progression and tyrosine kinase signaling by the multi-selective purvalanol A is effective in suppressing cancer progression associated with c-Src up-regulation. PMID:20825494

  7. MET inhibitor PHA-665752 suppresses the hepatocyte growth factor-induced cell proliferation and radioresistance in nasopharyngeal carcinoma cells

    SciTech Connect

    Liu, Tongxin; Li, Qi; Sun, Quanquan; Zhang, Yuqin; Yang, Hua; Wang, Rong; Chen, Longhua; Wang, Wei

    2014-06-20

    Highlights: • We demonstrated that irradiation induced MET overexpression and activation. • The aberrant MET signal mediated by HGF induced proliferation and radioresistance of NPC cells. • MET inhibitor PHA-665752 effectively suppressed HGF induced cell proliferation and radioresistance in NPC cells. • PHA-665752 suppressed the three downstream pathway of HGF/MET signal in a dose-dependent manner. - Abstract: Although ionizing radiation (IR) has provided considerable improvements in nasopharyngeal carcinoma (NPC), in subsets of patients, radioresistance is still a major problem in the treatment. In this study, we demonstrated that irradiation induced MET overexpression and activation, and the aberrant MET signal mediated by hepatocyte growth factor (HGF) induced radioresistance. We also found that MET inhibitor PHA-665752 effectively suppressed HGF induced cell proliferation and radioresistance in NPC cells. Further investigation indicated that PHA-665752 suppressed the phosphorylation of the Akt, ERK1/2, and STAT3 proteins in a dose-dependent manner. Our data indicated that the combination of IR with a MET inhibitor, such as PHA-665752, might be a promising therapeutic strategy for NPC.

  8. A novel PI3K inhibitor iMDK suppresses non-small cell lung Cancer cooperatively with A MEK inhibitor

    PubMed Central

    Ishida, Naomasa; Fukazawa, Takuya; Maeda, Yutaka; Yamatsuji, Tomoki; Takaoka, Munenori; Haisa, Minoru; Yokota, Etsuko; Shigemitsu, Kaori; Morita, Ichiro; Kato, Katsuya; Matsumoto, Kenichi; Shimo, Tsuyoshi; Okui, Tatsuo; Bao, Xiao-Hong; Hao, Huifang; Grant, Shawn N.; Takigawa, Nagio; Whitsett, Jeffrey A.; Naomoto, Yoshio

    2015-01-01

    The PI3K–AKT pathway is expected to be a therapeutic target for non-small cell lung cancer (NSCLC) treatment. We previously reported that a novel PI3K inhibitor iMDK suppressed NSCLC cells in vitro and in vivo without harming normal cells and mice. Unexpectedly, iMDK activated the MAPK pathway, including ERK, in the NSCLC cells. Since iMDK did not eradicate such NSCLC cells completely, it is possible that the activated MAPK pathway confers resistance to the NSCLC cells against cell death induced by iMDK. In the present study, we assessed whether suppressing of iMDK-mediated activation of the MAPK pathway would enhance anti-tumorigenic activity of iMDK. PD0325901, a MAPK inhibitor, suppressed the MAPK pathway induced by iMDK and cooperatively inhibited cell viability and colony formation of NSCLC cells by inducing apoptosis in vitro. HUVEC tube formation, representing angiogenic processes in vitro, was also cooperatively inhibited by the combinatorial treatment of iMDK and PD0325901. The combinatorial treatment of iMDK with PD0325901 cooperatively suppressed tumor growth and tumor-associated angiogenesis in a lung cancer xenograft model in vivo. Here, we demonstrate a novel treatment strategy using iMDK and PD0325901 to eradicate NSCLC. PMID:25839409

  9. EZH2 inhibition enhances the efficacy of an EGFR inhibitor in suppressing colon cancer cells

    PubMed Central

    Katona, Bryson W; Liu, Yuanyuan; Ma, Anqi; Jin, Jian; Hua, Xianxin

    2014-01-01

    Metastatic colon cancer has a 5-year survival of less than 10% despite the use of aggressive chemotherapeutic regimens. As signaling from epidermal growth factor receptor (EGFR) is often enhanced and epigenetic regulation is often altered in colon cancer, it is desirable to enhance the efficacy of EGFR-directed therapy by co-targeting an epigenetic pathway. We showed that the histone methyltransferase EZH2, which catalyzes methylation of histone H3 lysine 27 (H3K27), was upregulated in colon cancers in The Cancer Genome Atlas (TCGA) database. Since co-inhibition of both EGFR and EZH2 has not been studied in colon cancer, we examined the effects of co-inhibition of EGFR and EZH2 on 2 colon cancer cell lines, HT-29 and HCT-15. Co-inhibition of EZH2 and EGFR with the small molecules UNC1999 and gefitinib, led to a significant decrease in cell number and increased apoptosis compared to inhibition of either pathway alone, and similar results were noted after EZH2 shRNA knockdown. Moreover, co-inhibition of EZH2 and EGFR also significantly induced autophagy, indicating that autophagy may play a role in the observed synergy. Together, these findings suggest that inhibition of both EZH2 and EGFR serves as an effective method to increase the efficacy of EGFR inhibitors in suppressing colon cancer cells. PMID:25535899

  10. Dual Suppression of the Cyclin-Dependent Kinase Inhibitors CDKN2C and CDKN1A in Human Melanoma

    PubMed Central

    2012-01-01

    Resistance to BRAFV600E inhibitors is associated with reactivation of mitogen-activated protein kinase (MAPK) signaling at different levels in melanoma. To identify downstream effectors of MAPK signaling that could be used as potential additional therapeutic targets for BRAFV600E inhibitors, we used hTERT/CDK4R24C/p53DD-immortalized primary human melanocytes genetically modified to ectopically express BRAF V600E or NRAS G12D and observed induction of the AP-1 transcription factor family member c-Jun. Using a dominant negative approach, in vitro cell proliferation assays, western blots, and flow cytometry showed that MAPK signaling via BRAFV600E promotes melanoma cell proliferation at G1 through AP-1-mediated negative regulation of the INK4 family member, cyclin-dependent kinase inhibitor 2C (CDKN2C), and the CIP/KIP family member, cyclin-dependent kinase inhibitor 1A (CDKN1A). These effects were antagonized by pharmacological inhibition of CDKN2C and CDKN1A targets CDK2 and CDK4 in vitro. In contrast to BRAF V600E or NRAS G12D-expressing melanocytes, melanoma cells have an inherent resistance to suppression of AP-1 activity by BRAFV600E- or MEK-inhibitors. Here, CDK2/4 inhibition statistically significantly augmented the effects of BRAFV600E- or MEK-inhibitors on melanoma cell viability in vitro and growth in athymic nude Foxn1 nu mice (P = .03 when mean tumor volume at day 13 was compared for BRAFV600E inhibitor vs BRAFV600E inhibitor plus CDK2/4 inhibition; P = .02 when mean tumor volume was compared for MEK inhibitor vs MEK inhibitor plus CDK2/4 inhibition; P values were calculated by a two-sided Welch t test; n = 4–8 mice per group). PMID:22997239

  11. Inhibitors of cyclic nucleotide phosphodiesterase isozymes type-III and type-IV suppress mitogenesis of rat mesangial cells.

    PubMed Central

    Matousovic, K; Grande, J P; Chini, C C; Chini, E N; Dousa, T P

    1995-01-01

    We studied interactions between the mitogen-activated protein kinase (MAPK) signalling pathway and cAMP-protein kinase (PKA) signaling pathway in regulation of mitogenesis of mesangial cells (MC) determined by [3H]thymidine incorporation, with or without added EGF. Forskolin or dibutyryl cAMP strongly (by 60-70%) inhibited [3H]thymidine incorporation into MC. Cilostamide, lixazinone or cilostazol selective inhibitors of cAMP-phosphodiesterase (PDE) isozyme PDE-III, inhibited mitogenesis to similar extent as forskolin and DBcAMP and activated in situ PKA, but without detectable increase in cAMP levels. Cilostamide and cilostazol were more than three times more effective at inhibiting mesangial mitogenesis than rolipram and denbufylline, inhibitors of isozyme PDE-IV, even though PDE-IV was two times more abundant in MC than was PDE-III. On the other hand, when incubated with forskolin, rolipram-enhanced cAMP accumulation was far greater (10-100x) than with cilostamide. EGF increased MAPK activity (+300%); PDE isozyme inhibitors which suppressed mitogenesis also inhibited MAPK. PDE isozyme inhibitors also suppressed PDGF-stimulated MC proliferation. We conclude that cAMP inhibits the mitogen-dependent MAPK-signaling pathway probably by decreasing the activity of Raf-1 due to PKA-catalyzed phosphorylation. Further, we surmise that minor increase in the cAMP pool metabolized by PDE-III is intimately related to regulation of mesangial proliferation. Thus, PDE isozyme inhibitors have the potential to suppress MC proliferation by a focused effect upon signaling pathways. Images PMID:7615811

  12. Tissue Inhibitor of Metalloproteinase-2 Suppresses Collagen Synthesis in Cultured Keloid Fibroblasts

    PubMed Central

    Dohi, Teruyuki; Aoki, Masayo; Ogawa, Rei; Akaishi, Satoshi; Shimada, Takashi; Okada, Takashi; Hyakusoku, Hiko

    2015-01-01

    Background: Keloids are defined as a kind of dermal fibroproliferative disorder resulting from the accumulation of collagen. In the remodeling of extracellular matrix, the balance between matrix metalloproteinases (MMPs) and the tissue inhibitors of metalloproteinases (TIMPs) is as critical as the proper production of extracellular matrix. We investigate the role of TIMPs and MMPs in the pathogenesis of keloids and examine the therapeutic potential of TIMP-2. Methods: The expression of TIMPs and MMPs in most inflamed parts of cultured keloid fibroblasts (KFs) and peripheral normal skin fibroblasts (PNFs) in the same individuals and the reactivity of KFs to cyclic mechanical stretch were analyzed by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay (n = 7). To evaluate the effect of treating KFs with TIMP-2, collagen synthesis was investigated by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay, and microscopic analysis was used to examine the treatment effects of TIMP-2 on ex vivo cultures of keloid tissue (n = 6). Results: TIMP-2 was downregulated in cultured KFs compared with PNFs in the same individuals, and the reduction in TIMP-2 was exacerbated by cyclic mechanical stretch. Administration of TIMP-2 (200 or 300 ng/mL) significantly suppressed expression of Col1A2 and Col3A1 mRNA and collagen type I protein in KFs. TIMP-2 also significantly reduced the skin dermal and collagen bundle thickness in ex vivo cultures of keloid tissue. Conclusion: These results indicated that downregulation of TIMP-2 in KFs is a crucial event in the pathogenesis of keloids, and the TIMP-2 would be a promising candidate for the treatment of keloids. PMID:26495233

  13. Doravirine Suppresses Common Nonnucleoside Reverse Transcriptase Inhibitor-Associated Mutants at Clinically Relevant Concentrations.

    PubMed

    Feng, Meizhen; Sachs, Nancy A; Xu, Min; Grobler, Jay; Blair, Wade; Hazuda, Daria J; Miller, Michael D; Lai, Ming-Tain

    2016-04-01

    Doravirine (DOR), which is currently in a phase 3 clinical trial, is a novel human immunodeficiency type 1 virus (HIV-1) nonnucleoside reverse transcriptase inhibitor (NNRTI). DOR exhibits potent antiviral activity against wild-type virus and K103N, Y181C, and K103N/Y181C mutant viruses, with 50% inhibitory concentrations (IC50s) of 12, 21, 31, and 33 nM, respectively, when measured in 100% normal human serum (NHS). To assess the potential for DOR to suppress NNRTI-associated and rilpivirine (RPV)-specific mutants at concentrations achieved in the clinic setting, inhibitory quotients (IQs) were calculated by determining the ratio of the clinical trough concentration over the antiviral IC50for each virus with DOR and RPV and efavirenz (EFV). DOR displayed IQs of 39, 27, and 25 against the K103N, Y181C, and K103N/Y181C mutants, respectively. In contrast, RPV exhibited IQs of 4.6, 1.4, and 0.8, and EFV showed IQs of 2.5, 60, and 1.9 against these viruses, respectively. DOR also displayed higher IQs than those of RPV and EFV against other prevalent NNRTI-associated mutants, with the exception of Y188L. Both DOR and EFV exhibited higher IQs than RPV when analyzed with RPV-associated mutants. Resistance selections were conducted with K103N, Y181C, G190A, and K103N/Y181C mutants at clinically relevant concentrations of DOR, RPV, and EFV. No viral breakthrough was observed with DOR, whereas breakthrough viruses were readily detected with RPV and EFV against Y181C and K103N viruses, respectively. These data suggest that DOR should impose a higher barrier to the development of resistance than RPV and EFV at the concentrations achieved in the clinic setting. PMID:26833152

  14. Plasminogen Activator Inhibitor-1 Suppresses Profibrotic Responses in Fibroblasts from Fibrotic Lungs*

    PubMed Central

    Marudamuthu, Amarnath S.; Shetty, Shwetha K.; Bhandary, Yashodhar P.; Karandashova, Sophia; Thompson, Michael; Sathish, Venkatachalem; Florova, Galina; Hogan, Taryn B.; Pabelick, Christina M.; Prakash, Y. S.; Tsukasaki, Yoshikazu; Fu, Jian; Ikebe, Mitsuo; Idell, Steven; Shetty, Sreerama

    2015-01-01

    Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease characterized by progressive interstitial scarification. A hallmark morphological lesion is the accumulation of myofibroblasts or fibrotic lung fibroblasts (FL-fibroblasts) in areas called fibroblastic foci. We previously demonstrated that the expression of both urokinase-type plasminogen activator (uPA) and the uPA receptor are elevated in FL-fibroblasts from the lungs of patients with IPF. FL-fibroblasts isolated from human IPF lungs and from mice with bleomycin-induced pulmonary fibrosis showed an increased rate of proliferation compared with normal lung fibroblasts (NL-fibroblasts) derived from histologically “normal” lung. Basal expression of plasminogen activator inhibitor-1 (PAI-1) in human and murine FL-fibroblasts was reduced, whereas collagen-I and α-smooth muscle actin were markedly elevated. Conversely, alveolar type II epithelial cells surrounding the fibrotic foci in situ, as well as those isolated from IPF lungs, showed increased activation of caspase-3 and PAI-1 with a parallel reduction in uPA expression. Transduction of an adenovirus PAI-1 cDNA construct (Ad-PAI-1) suppressed expression of uPA and collagen-I and attenuated proliferation in FL-fibroblasts. On the contrary, inhibition of basal PAI-1 in NL-fibroblasts increased collagen-I and α-smooth muscle actin. Fibroblasts isolated from PAI-1-deficient mice without lung injury also showed increased collagen-I and uPA. These changes were associated with increased Akt/phosphatase and tensin homolog proliferation/survival signals in FL-fibroblasts, which were reversed by transduction with Ad-PAI-1. This study defines a new role of PAI-1 in the control of fibroblast activation and expansion and its role in the pathogenesis of fibrosing lung disease and, in particular, IPF. PMID:25648892

  15. Survivin inhibitor YM155 suppresses gastric cancer xenograft growth in mice without affecting normal tissues

    PubMed Central

    Cheng, Xiao Jiao; Lin, Jia Cheng; Ding, Yan Fei; Zhu, Liming; Ye, Jing; Tu, Shui Ping

    2016-01-01

    Survivin overexpression is associated with poor prognosis of human gastric cancer, and is a target for gastric cancer therapy. YM155 is originally identified as a specific inhibitor of survivin. In this study, we investigated the antitumor effect of YM155 on human gastric cancer. Our results showed that YM155 treatment significantly inhibited cell proliferation, reduced colony formation and induced apoptosis of gastric cancer cells in a dose-dependent manner. Accordingly, YM155 treatment significantly decreased survivin expression without affecting XIAP expression and increased the cleavage of apoptosis-associated proteins caspase 3, 7, 8, 9. YM155 significantly inhibited sphere formation of gastric cancer cells, suppressed expansion and growth of the formed spheres (cancer stem cell-like cells, CSCs) and downregulated the protein levels of β-catenin, c-Myc, Cyclin D1 and CD44 in gastric cancer cells. YM155 infusion at 5 mg/kg/day for 7 days markedly inhibited growth of gastric cancer xenograft in a nude mouse model. Immunohistochemistry staining and Western Blot showed that YM155 treatment inhibited expression of survivin and CD44, induced apoptosis and reduced CD44+ CSCs in xenograft tumor tissues in vivo. No obvious pathological changes were observed in organs (e.g. heart, liver, lung and kidney) in YM155-treated mice. Our results demonstrated that YM155 inhibits cell proliferation, induces cell apoptosis, reduces cancer stem cell expansion, and inhibits xenograft tumor growth in gastric cancer cells. Our results elucidate a new mechanism by which YM155 inhibits gastric cancer growth by inhibition of CSCs. YM155 may be a promising agent for gastric cancer treatment. PMID:26771139

  16. Survivin inhibitor YM155 suppresses gastric cancer xenograft growth in mice without affecting normal tissues.

    PubMed

    Cheng, Xiao Jiao; Lin, Jia Cheng; Ding, Yan Fei; Zhu, Liming; Ye, Jing; Tu, Shui Ping

    2016-02-01

    Survivin overexpression is associated with poor prognosis of human gastric cancer, and is a target for gastric cancer therapy. YM155 is originally identified as a specific inhibitor of survivin. In this study, we investigated the antitumor effect of YM155 on human gastric cancer. Our results showed that YM155 treatment significantly inhibited cell proliferation, reduced colony formation and induced apoptosis of gastric cancer cells in a dose-dependent manner. Accordingly, YM155 treatment significantly decreased survivin expression without affecting XIAP expression and increased the cleavage of apoptosis-associated proteins caspase 3, 7, 8, 9. YM155 significantly inhibited sphere formation of gastric cancer cells, suppressed expansion and growth of the formed spheres (cancer stem cell-like cells, CSCs) and downregulated the protein levels of β-catenin, c-Myc, Cyclin D1 and CD44 in gastric cancer cells. YM155 infusion at 5 mg/kg/day for 7 days markedly inhibited growth of gastric cancer xenograft in a nude mouse model. Immunohistochemistry staining and Western Blot showed that YM155 treatment inhibited expression of survivin and CD44, induced apoptosis and reduced CD44+ CSCs in xenograft tumor tissues in vivo. No obvious pathological changes were observed in organs (e.g. heart, liver, lung and kidney) in YM155-treated mice. Our results demonstrated that YM155 inhibits cell proliferation, induces cell apoptosis, reduces cancer stem cell expansion, and inhibits xenograft tumor growth in gastric cancer cells. Our results elucidate a new mechanism by which YM155 inhibits gastric cancer growth by inhibition of CSCs. YM155 may be a promising agent for gastric cancer treatment. PMID:26771139

  17. Suppression of IAPP fibrillation at anionic lipid membranes via IAPP-derived amyloid inhibitors and insulin.

    PubMed

    Sellin, Daniel; Yan, Li-Mei; Kapurniotu, Aphrodite; Winter, Roland

    2010-08-01

    Aggregation of human islet amyloid polypeptide (hIAPP) into cytotoxic beta-sheet oligomers and amyloid plaques is considered a key event in pancreatic beta-cell degeneration in type 2 diabetes (T2D). hIAPP is synthesized in the pancreatic beta-cells and it is stored, co-processed in the secretory granules, and co-secreted to the extracellular matrix together with insulin. In vivo, hIAPP aggregation may start and proceed at the water-cell membrane interface and anionic lipid membranes strongly enhance the process of hIAPP fibrillization which is causally linked to membrane disintegration and cell degeneration. In this study we explored the amyloidogenic propensity and conformational properties of hIAPP in the presence of negatively charged membrane (DOPC/DOPG phospholipid bilayers) surfaces upon addition of two recently designed potent hIAPP-derived inhibitors of hIAPP amyloidogenesis, the hexapeptide NF(N-Me)GA(N-Me)IL (NFGAIL-GI) and the 37-residue non-amyloidogenic hIAPP analog [(N-Me)G24, (N-Me)I26]-IAPP (IAPP-GI). For comparison, the effects of insulin, which is a natively occurring hIAPP aggregation inhibitor, rat IAPP (rIAPP), which is a natively non-amyloidogenic hIAPP analog, and the hIAPP amyloid core peptide hIAPP(22-27) or NFGAIL were also studied. The aim of our study was to test whether and how the above peptides which have been shown to completely block or suppress hIAPP amyloidogenesis in bulk solution in vitro would also affect these processes in the presence of lipid membranes. To this end, attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) was applied. We find that IAPP-GI, NFGAIL-GI, insulin, and rIAPP are potent inhibitors of hIAPP fibrillization. Importantly, our data also suggest that the hetero-complexes of IAPP-GI, rIAPP, and insulin with hIAPP although non-amyloidogenic per se are still able to adsorb at the lipid membrane. By contrast, in the presence of NFGAIL-GI, interaction of hIAPP with the lipid membrane is

  18. Potentiated suppression of Dickkopf-1 in breast cancer by combined administration of the mevalonate pathway inhibitors zoledronic acid and statins.

    PubMed

    Göbel, Andy; Browne, Andrew J; Thiele, Stefanie; Rauner, Martina; Hofbauer, Lorenz C; Rachner, Tilman D

    2015-12-01

    The Wnt-inhibitor dickkopf-1 (DKK-1) promotes cancer-induced osteolytic bone lesions by direct inhibition of osteoblast differentiation and indirect activation of osteoclasts. DKK-1 is highly expressed in human breast cancer cells and can be suppressed by inhibitors of the mevalonate pathway such as statins and amino-bisphosphonates. However, supraphysiological concentrations are required to suppress DKK-1. We show that a sequential mevalonate pathway blockade using statins and amino-bisphosphonates suppresses DKK-1 more significantly than the individual agents alone. Thus, the reduction of the DKK-1 expression and secretion in the human osteotropic tumor cell lines MDA-MB-231, MDA-MET, and MDA-BONE by zoledronic acid was potentiated by the combination with low concentrations of statins (atorvastatin, simvastatin, and rosuvastatin) by up to 75% (p < 0.05). The specific rescue of prenylation using farnesyl pyrophosphate or geranylgeranyl pyrophosphate revealed that these effects were mediated by suppressed geranylgeranylation rather than by suppressed farnesylation. Moreover, combining low concentrations of statins (1 µM atorvastatin or 0.25 µM simvastatin) and zoledronic acid at low concentrations resulted in an at least 50% reversal of breast cancer-derived DKK-1-mediated inhibition of osteogenic markers in C2C12 cells (p < 0.05). Finally, the intratumoral injection of atorvastatin and zoledronic acid in as subcutaneous MDA-MB-231 mouse model reduced the serum level of human DKK-1 by 25% compared to untreated mice. Hence our study reveals that a sequential mevalonate pathway blockade allows for the combined use of low concentration of statins and amino-bisphosphonates. This combination still significantly suppresses breast cancer-derived DKK-1 to levels where it can no longer inhibit Wnt-mediated osteoblast differentiation. PMID:26515701

  19. Peptidylarginine Deiminase Inhibitor Suppresses Neutrophil Extracellular Trap Formation and MPO-ANCA Production

    PubMed Central

    Kusunoki, Yoshihiro; Nakazawa, Daigo; Shida, Haruki; Hattanda, Fumihiko; Miyoshi, Arina; Masuda, Sakiko; Nishio, Saori; Tomaru, Utano; Atsumi, Tatsuya; Ishizu, Akihiro

    2016-01-01

    Myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA)-associated vasculitis is a systemic small-vessel vasculitis, wherein, MPO-ANCA plays a critical role in the pathogenesis. Neutrophil extracellular traps (NETs) released from activated neutrophils are composed of extracellular web-like DNA and antimicrobial proteins, including MPO. Diverse stimuli, such as phorbol myristate acetate (PMA) and ligands of toll-like receptors (TLR), induce NETs. Although TLR-mediated NET formation can occur with preservation of living neutrophilic functions (called vital NETosis), PMA-stimulated neutrophils undergo cell death with NET formation (called suicidal NETosis). In the process of suicidal NETosis, histones are citrullinated by peptidylarginine deiminase 4 (PAD4). Since this step is necessary for decondensation of DNA, PAD4 plays a pivotal role in suicidal NETosis. Although NETs are essential for elimination of microorganisms, excessive formation of NETs has been suggested to be implicated in MPO-ANCA production. This study aimed to determine if pan-PAD inhibitors could suppress MPO-ANCA production in vivo. At first, NETs were induced in peripheral blood neutrophils derived from healthy donors (1 × 106/ml) by stimulation with 20 nM PMA with or without 20 μM propylthiouracil (PTU), an anti-thyroid drug. We then determined that the in vitro NET formation was inhibited completely by 200 μM Cl-amidine, a pan-PAD inhibitor. Next, we established mouse models with MPO-ANCA production. BALB/c mice were given intraperitoneal (i.p.) injection of PMA (50 ng at days 0 and 7) and oral PTU (2.5 mg/day) for 2 weeks. These mice were divided into two groups; the first group was given daily i.p. injection of PBS (200 μl/day) (n = 13) and the other group with daily i.p. injection of Cl-amidine (0.3 mg/200 μl PBS/day) (n = 7). Two weeks later, citrullination as an indicator of NET formation in the peritoneum and serum MPO-ANCA titer was compared

  20. Peptidylarginine Deiminase Inhibitor Suppresses Neutrophil Extracellular Trap Formation and MPO-ANCA Production.

    PubMed

    Kusunoki, Yoshihiro; Nakazawa, Daigo; Shida, Haruki; Hattanda, Fumihiko; Miyoshi, Arina; Masuda, Sakiko; Nishio, Saori; Tomaru, Utano; Atsumi, Tatsuya; Ishizu, Akihiro

    2016-01-01

    Myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA)-associated vasculitis is a systemic small-vessel vasculitis, wherein, MPO-ANCA plays a critical role in the pathogenesis. Neutrophil extracellular traps (NETs) released from activated neutrophils are composed of extracellular web-like DNA and antimicrobial proteins, including MPO. Diverse stimuli, such as phorbol myristate acetate (PMA) and ligands of toll-like receptors (TLR), induce NETs. Although TLR-mediated NET formation can occur with preservation of living neutrophilic functions (called vital NETosis), PMA-stimulated neutrophils undergo cell death with NET formation (called suicidal NETosis). In the process of suicidal NETosis, histones are citrullinated by peptidylarginine deiminase 4 (PAD4). Since this step is necessary for decondensation of DNA, PAD4 plays a pivotal role in suicidal NETosis. Although NETs are essential for elimination of microorganisms, excessive formation of NETs has been suggested to be implicated in MPO-ANCA production. This study aimed to determine if pan-PAD inhibitors could suppress MPO-ANCA production in vivo. At first, NETs were induced in peripheral blood neutrophils derived from healthy donors (1 × 10(6)/ml) by stimulation with 20 nM PMA with or without 20 μM propylthiouracil (PTU), an anti-thyroid drug. We then determined that the in vitro NET formation was inhibited completely by 200 μM Cl-amidine, a pan-PAD inhibitor. Next, we established mouse models with MPO-ANCA production. BALB/c mice were given intraperitoneal (i.p.) injection of PMA (50 ng at days 0 and 7) and oral PTU (2.5 mg/day) for 2 weeks. These mice were divided into two groups; the first group was given daily i.p. injection of PBS (200 μl/day) (n = 13) and the other group with daily i.p. injection of Cl-amidine (0.3 mg/200 μl PBS/day) (n = 7). Two weeks later, citrullination as an indicator of NET formation in the peritoneum and serum MPO-ANCA titer was compared

  1. Cyclin-dependent kinase inhibitor drugs as potential novel anti-inflammatory and pro-resolution agents

    PubMed Central

    Leitch, AE; Haslett, C; Rossi, AG

    2009-01-01

    The cyclin-dependent kinase inhibitor (CDKi) drugs such as R-roscovitine have emerged as potential anti-inflammatory, pharmacological agents that can influence the resolution of inflammation. Usually, once an inciting inflammatory stimulus has been eliminated, resolution proceeds by prompt, safe removal of dominant inflammatory cells. This is accomplished by programmed cell death (apoptosis) of prominent effector, inflammatory cells typified by the neutrophil. Apoptosis of neutrophils ensures that toxic neutrophil granule contents are securely packaged in apoptotic bodies and expedites phagocytosis by professional phagocytes such as macrophages. A panel of CDKi drugs have been shown to promote neutrophil apoptosis in a concentration- and time-dependent manner and the archetypal CDKi drug, R-roscovitine, overrides the anti-apoptotic effects of powerful survival factors [including lipopolysaccharide (LPS) and granulocyte macrophage-colony stimulating factor (GM-CSF)]. Inflammatory cell longevity and survival signalling is integral to the inflammatory process and any putative anti-inflammatory agent must unravel a complex web of redundancy in order to be effective. CDKi drugs have also been demonstrated to have significant effects on other cell types including lymphocytes and fibroblasts indicating that they may have pleiotropic anti-inflammatory, pro-resolution activity. In keeping with this, CDKi drugs like R-roscovitine have been reported to be efficacious in resolving established animal models of neutrophil-dominant and lymphocyte-driven inflammation. However, the mechanism of action behind these powerful effects has not yet been fully elucidated. CDKs play an integral role in the regulation of the cell cycle but are also recognized as participants in processes such as apoptosis and transcriptional regulation. Neutrophils have functional CDKs, are transcriptionally active and demonstrate augmented apoptosis in response to CDKi drugs, while lymphocyte proliferation

  2. Suppression of complement regulatory protein C1 inhibitor in vascular endothelial activation by inhibiting vascular cell adhesion molecule-1 action

    SciTech Connect

    Zhang, Haimou; Qin, Gangjian; Liang, Gang; Li, Jinan; Chiu, Isaac; Barrington, Robert A.; Liu, Dongxu . E-mail: dxliu001@yahoo.com

    2007-07-13

    Increased expression of adhesion molecules by activated endothelium is a critical feature of vascular inflammation associated with the several diseases such as endotoxin shock and sepsis/septic shock. Our data demonstrated complement regulatory protein C1 inhibitor (C1INH) prevents endothelial cell injury. We hypothesized that C1INH has the ability of an anti-endothelial activation associated with suppression of expression of adhesion molecule(s). C1INH blocked leukocyte adhesion to endothelial cell monolayer in both static assay and flow conditions. In inflammatory condition, C1INH reduced vascular cell adhesion molecule (VCAM-1) expression associated with its cytoplasmic mRNA destabilization and nuclear transcription level. Studies exploring the underlying mechanism of C1INH-mediated suppression in VCAM-1 expression were related to reduction of NF-{kappa}B activation and nuclear translocation in an I{kappa}B{alpha}-dependent manner. The inhibitory effects were associated with reduction of inhibitor I{kappa}B kinase activity and stabilization of the NF-{kappa}B inhibitor I{kappa}B. These findings indicate a novel role for C1INH in inhibition of vascular endothelial activation. These observations could provide the basis for new therapeutic application of C1INH to target inflammatory processes in different pathologic situations.

  3. Suppression of Angiogenesis and Tumor Growth by the Inhibitor K1-5 Generated by Plasmin-Mediated Proteolysis

    NASA Astrophysics Data System (ADS)

    Cao, Renhai; Wu, Hua-Lin; Veitonmaki, Niina; Linden, Philip; Farnebo, Jacob; Shi, Guey-Yueh; Cao, Yihai

    1999-05-01

    Proteolytic enzymes are involved in generation of a number of endogenous angiogenesis inhibitors. Previously, we reported that angiostatin, a potent angiogenesis inhibitor, is a protcolytic fragment containing the first four kringle modules of plasminogen. In this report, we demonstrate that urokinase-activated plasmin can process plasminogen to release an angiogenesis inhibitor, K1-5 (protease-activated kringles 1-5). K1-5 inhibits endothelial-cell proliferation with a half-maximal concentration of approximately 50 pM. This inhibitory effect is endothelial-cell-specific and appears to be at least approximately 50-fold greater than that of angiostatin. A synergistic efficacy of endothelial inhibition was observed when angiostatin and kringle 5 (K5) were coincubated with capillary endothelial cells. The synergistic effect is comparable to that produced by K1-5 alone. Systemic treatment of mice with K1-5 at a low dose significantly blocked the fibroblast growth factor-induced corneal neovascularization, whereas angiostatin had no effect at the same dose. K1-5 also suppressed angiogenesis in chicken embryos. Systemic administration of K1-5 at a low dose at which angiostatin was ineffective significantly suppressed the growth of a murine T241 fibrosarcoma in mice. The antitumor effect correlates with the reduced neovascularization. These findings suggest that the plasmin-mediated proteolysis may be involved in the negative switch of angiogenesis.

  4. The X-Linked Inhibitor of Apoptosis Protein Inhibitor Embelin Suppresses Inflammation and Bone Erosion in Collagen Antibody Induced Arthritis Mice

    PubMed Central

    Dharmapatni, Anak A. S. S. K.; Cantley, Melissa D.; Marino, Victor; Perilli, Egon; Crotti, Tania N.; Smith, Malcolm D.; Haynes, David R.

    2015-01-01

    Objective. To investigate the effect of Embelin, an inhibitor of X-Linked Inhibitor of Apoptosis Protein (XIAP), on inflammation and bone erosion in a collagen antibody induced arthritis (CAIA) in mice. Methods. Four groups of mice (n = 6 per group) were allocated: CAIA untreated mice, CAIA treated with Prednisolone (10 mg/kg/day), CAIA treated with low dose Embelin (30 mg/kg/day), and CAIA treated with high dose Embelin (50 mg/kg/day). Joint inflammation was evaluated using clinical paw score and histological assessments. Bone erosion was assessed using micro-CT, tartrate resistant acid phosphatase (TRAP) staining, and serum carboxy-terminal collagen crosslinks (CTX-1) ELISA. Immunohistochemistry was used to detect XIAP protein. TUNEL was performed to identify apoptotic cells. Results. Low dose, but not high dose Embelin, suppressed inflammation as reflected by lower paw scores (P < 0.05) and lower histological scores for inflammation. Low dose Embelin reduced serum CTX-1 (P < 0.05) and demonstrated lower histological score and TRAP counting, and slightly higher bone volume as compared to CAIA untreated mice. XIAP expression was not reduced but TUNEL positive cells were more abundant in Embelin treated CAIA mice. Conclusion. Low dose Embelin suppressed inflammation and serum CTX-1 in CAIA mice, indicating a potential use for Embelin to treat pathological bone loss. PMID:26347311

  5. Development of an orally-administrative MELK-targeting inhibitor that suppresses the growth of various types of human cancer.

    PubMed

    Chung, Suyoun; Suzuki, Hanae; Miyamoto, Takashi; Takamatsu, Naofumi; Tatsuguchi, Ayako; Ueda, Koji; Kijima, Kyoko; Nakamura, Yusuke; Matsuo, Yo

    2012-12-01

    We previously reported MELK (maternal embryonic leucine zipper kinase) as a novel therapeutic target for breast cancer. MELK was also reported to be highly upregulated in multiple types of human cancer. It was implied to play indispensable roles in cancer cell survival and indicated its involvement in the maintenance of tumor-initiating cells. We conducted a high-throughput screening of a compound library followed by structure-activity relationship studies, and successfully obtained a highly potent MELK inhibitor OTSSP167 with IC₅₀ of 0.41 nM. OTSSP167 inhibited the phosphorylation of PSMA1 (proteasome subunit alpha type 1) and DBNL (drebrin-like), which we identified as novel MELK substrates and are important for stem-cell characteristics and invasiveness. The compound suppressed mammosphere formation of breast cancer cells and exhibited significant tumor growth suppression in xenograft studies using breast, lung, prostate, and pancreas cancer cell lines in mice by both intravenous and oral administration. This MELK inhibitor should be a promising compound possibly to suppress the growth of tumor-initiating cells and be applied for treatment of a wide range of human cancer. PMID:23283305

  6. Suppression of IL-12p40-related regulatory cytokines by suberoylanilide hydroxamic acid an inhibitor of histone deacetylases.

    PubMed

    Dobreva, Zlatka Georgieva; Grigorov, Boncho Grigorov; Stanilova, Spaska Angelova

    2016-08-01

    Small molecule inhibitors of histone deacetylases (HDACs) are a new class drugs used in clinical trials for the treatment of various malignancies. Emerging evidence suggest that HDAC inhibitors may also have anti-inflammatory properties, although the molecular mechanisms remain poorly defined. Our study investigates the effect of the HDACs inhibitor suberoylanilide hydroxamic acid (SAHA) on the expression of IL-12p40-related cytokines. For this purpose, human peripheral blood mononuclear cells (PBMC) were stimulated with LPS and C3bgp with or without SAHA. IL-12p40, IL-12p35 and IL-23p19 mRNA was determined at 6 h by qRT-PCR. Cytokine levels were determined in culture supernatants at 6 and 24 h, by ELISA. SAHA significantly inhibited IL-12p40 and IL-23p19 mRNA synthesis and did not change IL-12p35 mRNA transcription. Early at 6 h, we detected significantly decreased IL-12p40 and IL-23, but not IL-12p70 protein production in cultures treated with SAHA. Results also showed that the suppression of IL-12p40-related cytokines was clearly defined at 24 h. However, this suppression was less pronounced regarding IL-12p70. The present study showed that SAHA suppressed the gene expression of IL-23p19 stronger than the expression of IL-12p35, as well as the synthesis of IL-23 compared to that of IL-12p70. We suggest that this inhibitory effect of SAHA may be beneficial during treatment of inflammatory and autoimmune diseases mediated by Th17 immune response. PMID:27240992

  7. Dose-Dependent Suppression of Cytokine production from T cells by a Novel Phosphoinositide 3-Kinase Delta Inhibitor

    PubMed Central

    Way, Emily E.; Trevejo-Nunez, Giraldina; Kane, Lawrence P.; Steiner, Bart H.; Puri, Kamal D.; Kolls, Jay K.; Chen, Kong

    2016-01-01

    There remains a significant need for development of effective small molecules that can inhibit cytokine-mediated inflammation. Phosphoinositide 3 kinase (PI3K) is a direct upstream activator of AKT, and plays a critical role in multiple cell signaling pathways, cell cycle progression, and cell growth, and PI3K inhibitors have been approved or are in clinical development. We examined novel PI3Kdelta inhibitors, which are highly selective for the p110delta isoform of in CD3/CD28 stimulated T-cell cytokine production. In vitro generated CD4+ T effector cells stimulated in the presence of a PI3Kdelta inhibitor demonstrated a dose-dependent suppression of cytokines produced by Th1, Th2, and Th17 cells. This effect was T-cell intrinsic, and we observed similar effects on human PBMCs. Th17 cells expressing a constitutively activated form of AKT were resistant to PI3Kdelta inhibition, suggesting that the inhibitor is acting through AKT signaling pathways. Additionally, PI3Kdelta inhibition decreased IL-17 production in vivo and decreased neutrophil recruitment to the lung in a murine model of acute pulmonary inflammation. These experiments show that targeting PI3Kdelta activity can modulate T-cell cytokine production and reduce inflammation in vivo, suggesting that PI3Kdelta inhibition could have therapeutic potential in treating inflammatory diseases. PMID:27461849

  8. Combining BET and HDAC inhibitors synergistically induces apoptosis of melanoma and suppresses AKT and YAP signaling

    PubMed Central

    Heinemann, Anja; Cullinane, Carleen; De Paoli-Iseppi, Ricardo; Wilmott, James S.; Gunatilake, Dilini; Madore, Jason; Strbenac, Dario; Yang, Jean Y.; Gowrishankar, Kavitha; Tiffen, Jessamy C.; Prinjha, Rab K.; Smithers, Nicholas; McArthur, Grant A.; Hersey, Peter; Gallagher, Stuart J.

    2015-01-01

    Histone acetylation marks have an important role in controlling gene expression and are removed by histone deacetylases (HDACs). These marks are read by bromodomain and extra-terminal (BET) proteins and novel inhibitiors of these proteins are currently in clinical development. Inhibitors of HDAC and BET proteins have individually been shown to cause apoptosis and reduce growth of melanoma cells. Here we show that combining the HDAC inhibitor LBH589 and BET inhibitor I-BET151 synergistically induce apoptosis of melanoma cells but not of melanocytes. Induction of apoptosis proceeded through the mitochondrial pathway, was caspase dependent and involved upregulation of the BH3 pro-apoptotic protein BIM. Analysis of signal pathways in melanoma cell lines resistant to BRAF inhibitors revealed that treatment with the combination strongly downregulated anti-apoptotic proteins and proteins in the AKT and Hippo/YAP signaling pathways. Xenograft studies showed that the combination of inhibitors was more effective than single drug treatment and confirmed upregulation of BIM and downregulation of XIAP as seen in vitro. These results support the combination of these two classes of epigenetic regulators in treatment of melanoma including those resistant to BRAF inhibitors. PMID:26087189

  9. Reversal of high dietary fructose-induced PPARalpha suppression by oral administration of lipoxygenase/cyclooxygenase inhibitors.

    PubMed

    Kelley, Glen L; Azhar, Salman

    2005-08-01

    High fructose feeding causes diet-induced alterations of lipid metabolism and decreased insulin sensitivity, hallmark of which is a rapid and profound hypertriglyceridemia. One of the mechanisms that contribute to serum hypertriglyceridemia in this model is suppression of hepatic PPARalpha. HMG-CoA inhibitors, which reduce serum triglycerides in these animals, also elevate/restore hepatic PPARalpha. Previously we demonstrated that two known lipoxygenase/cyclooxygenase inhibitors reversed diet-induced hypertriglyceridemia in this model and that reversal of certain inflammatory markers in the liver correlated with the metabolic benefit. In this paper we extended these studies by examining the impact of these compounds on expression of PPARalpha, both at the level of transcription and expression. Our data show that diet-induced suppression of hepaic PPARalpha is reversed upon treatment with lipoxygenase/cyclooxygenase compounds. We then tested one of these compounds, BW-755c, over a range of doses from 10 mg/kg to 100 mg/kg to establish a dose-response relationship with the reduction of serum hypertriglyceridemia in this model. These experiments support the concept of using anti-inflammatory medications as one method to correct metabolic dysfunction. PMID:16091142

  10. The Rho-kinase inhibitor HA-1077 suppresses proliferation/migration and induces apoptosis of urothelial cancer cells

    PubMed Central

    2014-01-01

    Background Activation of Rho, one of the small GTPases, and its major downstream target Rho-kinase (ROCK) promotes the development and metastasis of cancer. We previously showed that elevation of Rho and ROCK expression was associated with tumor invasion, metastasis, and an unfavorable prognosis in patients with urothelial cancer of the bladder or upper urinary tract. Methods We investigated the effects of a ROCK inhibitor on the growth, migration, and apoptosis of bladder cancer cells. We also examined phosphorylation of RhoA (RhoA activity) by measuring its GTP-bound active form and assessed the expression of ROCK to explore the underlying molecular mechanisms. Results Lysophosphatidic acid (LPA) and geranylgeraniol (GGOH) induced an increase of cell proliferation and migration in association with promotion of RhoA activity and upregulation of ROCK expression. The ROCK inhibitor fasudil (HA-1077) suppressed cell proliferation and migration, and also induced apoptosis in a dose-dependent manner. HA-1077 dramatically suppressed the expression of ROCK-I and ROCK-II, but did not affect RhoA activity. Conclusions These findings suggest that ROCK could be a potential molecular target for the treatment of urothelial cancer. PMID:24908363

  11. Histone deacetylase inhibitor valproic acid promotes the induction of pluripotency in mouse fibroblasts by suppressing reprogramming-induced senescence stress

    SciTech Connect

    Zhai, Yingying; Chen, Xi; Yu, Dehai; Li, Tao; Cui, Jiuwei; Wang, Guanjun; Hu, Ji-Fan; Li, Wei

    2015-09-10

    Histone deacetylase inhibitor valproic acid (VPA) has been used to increase the reprogramming efficiency of induced pluripotent stem cell (iPSC) from somatic cells, yet the specific molecular mechanisms underlying this effect is unknown. Here, we demonstrate that reprogramming with lentiviruses carrying the iPSC-inducing factors (Oct4-Sox2-Klf4-cMyc, OSKM) caused senescence in mouse fibroblasts, establishing a stress barrier for cell reprogramming. Administration of VPA protected cells from reprogramming-induced senescent stress. Using an in vitro pre-mature senescence model, we found that VPA treatment increased cell proliferation and inhibited apoptosis through the suppression of the p16/p21 pathway. In addition, VPA also inhibited the G2/M phase blockage derived from the senescence stress. These findings highlight the role of VPA in breaking the cell senescence barrier required for the induction of pluripotency. - Highlights: • Histone deacetylase inhibitor valproic acid enhances iPSC induction. • Valproic acid suppresses reprogramming-induced senescence stress. • Valproic acid downregulates the p16/p21 pathway in reprogramming. • This study demonstrates a new mechanistic role of valproic acid in enhancing reprogramming.

  12. Cholesterol biosynthesis inhibitor RO 48-8071 suppresses growth of hormone-dependent and castration-resistant prostate cancer cells

    PubMed Central

    Liang, Yayun; Mafuvadze, Benford; Aebi, Johannes D; Hyder, Salman M

    2016-01-01

    Standard treatment for primary prostate cancer includes systemic exposure to chemotherapeutic drugs that target androgen receptor or antihormone therapy (chemical castration); however, drug-resistant cancer cells generally emerge during treatment, limiting the continued use of systemic chemotherapy. Patients are then treated with more toxic standard therapies. Therefore, there is an urgent need for novel and more effective treatments for prostate cancer. The cholesterol biosynthetic pathway is an attractive therapeutic target for treating endocrine-dependent cancers because cholesterol is an essential structural and functional component of cell membranes as well as the metabolic precursor of endogenous steroid hormones. In this study, we have examined the effects of RO 48-8071 (4′-[6-(allylmethylamino)hexyloxy]-4-bromo-2′-fluorobenzophenone fumarate; Roche Pharmaceuticals internal reference: RO0488071) (RO), which is an inhibitor of 2, 3-oxidosqualene cyclase (a key enzyme in the cholesterol biosynthetic pathway), on prostate cancer cells. Exposure of both hormone-dependent and castration-resistant human prostate cancer cells to RO reduced prostate cancer cell viability and induced apoptosis in vitro. RO treatment reduced androgen receptor protein expression in hormone-dependent prostate cancer cells and increased estrogen receptor β (ERβ) protein expression in both hormone-dependent and castration-resistant prostate cancer cell lines. Combining RO with an ERβ agonist increased its ability to reduce castration-resistant prostate cancer cell viability. In addition, RO effectively suppressed the growth of aggressive castration-resistant human prostate cancer cell xenografts in vivo without any signs of toxicity to experimental animals. Importantly, RO did not reduce the viability of normal prostate cells in vitro. Our study is the first to demonstrate that the cholesterol biosynthesis inhibitor RO effectively suppresses growth of human prostate cancer cells

  13. The dopamine β-hydroxylase inhibitor, nepicastat, suppresses chocolate self-administration and reinstatement of chocolate seeking in rats.

    PubMed

    Zaru, Alessandro; Maccioni, Paola; Colombo, Giancarlo; Gessa, Gian Luigi

    2013-10-01

    Craving for chocolate is a common phenomenon, which may evolve to an addictive-like behaviour and contribute to obesity. Nepicastat is a selective dopamine β-hydroxylase (DBH) inhibitor that suppresses cocaine-primed reinstatement of cocaine seeking in rats. We verified whether nepicastat was able to modify the reinforcing and motivational properties of a chocolate solution and to prevent the reinstatement of chocolate seeking in rats. Nepicastat (25, 50 and 100 mg/kg, intraperitoneal) produced a dose-related inhibition of operant self-administration of the chocolate solution in rats under fixed-ratio 10 (FR10) and progressive-ratio schedules of reinforcement, measures of the reinforcing and motivational properties of the chocolate solution, respectively. The effect of nepicastat on the reinstatement of chocolate seeking was studied in rats in which lever-responding had been extinguished by removing the chocolate solution for approximately 8 d. Nepicastat dose-dependently suppressed the reinstatement of lever-responding triggered by a 'priming' of the chocolate solution together with cues previously associated with the availability of the reward. In a separate group of food-restricted rats trained to lever-respond for regular food pellets, nepicastat reduced FR10 lever-responding with the same potency as for the chocolate solution. Spontaneous locomotor activity was not modified by nepicastat doses that reduced self-administration of the chocolate solution and regular food pellets and suppressed the reinstatement of chocolate seeking. The results indicate that nepicastat reduces motivation to food consumption sustained by appetite or palatability. Moreover, the results suggest that DBH inhibitors may be a new class of pharmacological agents potentially useful in the prevention of relapse to food seeking in human dieters. PMID:23561307

  14. Small-molecule inhibitors suppress the expression of both type III secretion and amylovoran biosynthesis genes in Erwinia amylovora.

    PubMed

    Yang, Fan; Korban, Schuyler S; Pusey, P Lawrence; Elofsson, Michael; Sundin, George W; Zhao, Youfu

    2014-01-01

    The type III secretion system (T3SS) and exopolysaccharide (EPS) amylovoran are two essential pathogenicity factors in Erwinia amylovora, the causal agent of the serious bacterial disease fire blight. In this study, small molecules that inhibit T3SS gene expression in E. amylovora under hrp (hypersensitive response and pathogenicity)-inducing conditions were identified and characterized using green fluorescent protein (GFP) as a reporter. These compounds belong to salicylidene acylhydrazides and also inhibit amylovoran production. Microarray analysis of E. amylovora treated with compounds 3 and 9 identified a total of 588 significantly differentially expressed genes. Among them, 95 and 78 genes were activated and suppressed by both compounds, respectively, when compared with the dimethylsulphoxide (DMSO) control. The expression of the majority of T3SS genes in E. amylovora, including hrpL and the avrRpt2 effector gene, was suppressed by both compounds. Compound 3 also suppressed the expression of amylovoran precursor and biosynthesis genes. However, both compounds induced significantly the expression of glycogen biosynthesis genes and siderophore biosynthesis, regulatory and transport genes. Furthermore, many membrane, lipoprotein and exported protein-encoding genes were also activated by both compounds. Similar expression patterns were observed for compounds 1, 2 and 4. Using crab apple flower as a model, compound 3 was capable of reducing disease development in pistils. These results suggest a common inhibition mechanism shared by salicylidene acylhydrazides and indicate that small-molecule inhibitors that disable T3SS function could be explored to control fire blight disease. PMID:23915008

  15. IKK inhibitor suppresses epithelial-mesenchymal transition and induces cell death in prostate cancer.

    PubMed

    Ping, Hao; Yang, Feiya; Wang, Mingshuai; Niu, Yinong; Xing, Nianzeng

    2016-09-01

    IκB kinase (IKK)/nuclear factor κB (NF-κB) pathway activation is a key event in the acquisition of invasive and metastatic capacities in prostate cancer. A potent small-molecule compound, BMS-345541, was identified as a highly selective IKKα and IKKβ inhibitor to inhibit kinase activity. This study explored the effect of IKK inhibitor on epithelial-mesenchymal transition (EMT), apoptosis and metastasis in prostate cancer. Here, we demonstrate the role of IKK inhibitor reducing proliferation and inducing apoptosis in PC-3 cells. Furthermore, BMS345541 inhibited IκBα phosphorylation and nuclear level of NF-κB/p65 in PC-3 cells. We also observed downregulation of the N-cadherin, Snail, Slug and Twist protein in a dose-dependent manner. BMS‑345541 induced upregulation of the epithelial marker E-cadherin and phosphorylated NDRG1 at protein level. Moreover, BMS‑345541 reduced invasion and metastasis of PC-3 cells in vitro. In conclusion, IKK has a key role in both EMT and apoptosis of prostate cancer. IKK inhibitor can reverse EMT and induce cell death in PCa cells. IKK was identified as a potential target structure for future therapeutic intervention in PCa. PMID:27432067

  16. DNMT (DNA methyltransferase) inhibitors radiosensitize human cancer cells by suppressing DNA repair activity

    PubMed Central

    2012-01-01

    Background Histone modifications and DNA methylation are two major factors in epigenetic phenomenon. Unlike the histone deacetylase inhibitors, which are known to exert radiosensitizing effects, there have only been a few studies thus far concerning the role of DNA methyltransferase (DNMT) inhibitors as radiosensitizers. The principal objective of this study was to evaluate the effects of DNMT inhibitors on the radiosensitivity of human cancer cell lines, and to elucidate the mechanisms relevant to that process. Methods A549 (lung cancer) and U373MG (glioblastoma) cells were exposed to radiation with or without six DNMT inhibitors (5-azacytidine, 5-aza-2'-deoxycytidine, zebularine, hydralazine, epigallocatechin gallate, and psammaplin A) for 18 hours prior to radiation, after which cell survival was evaluated via clonogenic assays. Cell cycle and apoptosis were analyzed via flow cytometry. Expressions of DNMT1, 3A/3B, and cleaved caspase-3 were detected via Western blotting. Expression of γH2AX, a marker of radiation-induced DNA double-strand break, was examined by immunocytochemistry. Results Pretreatment with psammaplin A, 5-aza-2'-deoxycytidine, and zebularine radiosensitized both A549 and U373MG cells. Pretreatment with psammaplin A increased the sub-G1 fraction of A549 cells, as compared to cells exposed to radiation alone. Prolongation of γH2AX expression was observed in the cells treated with DNMT inhibitors prior to radiation as compared with those treated by radiation alone. Conclusions Psammaplin A, 5-aza-2'-deoxycytidine, and zebularine induce radiosensitivity in both A549 and U373MG cell lines, and suggest that this effect might be associated with the inhibition of DNA repair. PMID:22429326

  17. A novel tankyrase small-molecule inhibitor suppresses APC mutation-driven colorectal tumor growth.

    PubMed

    Lau, Ted; Chan, Emily; Callow, Marinella; Waaler, Jo; Boggs, Jason; Blake, Robert A; Magnuson, Steven; Sambrone, Amy; Schutten, Melissa; Firestein, Ron; Machon, Ondrej; Korinek, Vladimir; Choo, Edna; Diaz, Dolores; Merchant, Mark; Polakis, Paul; Holsworth, Daniel D; Krauss, Stefan; Costa, Mike

    2013-05-15

    Most colorectal cancers (CRC) are initiated by mutations of APC, leading to increased β-catenin-mediated signaling. However, continued requirement of Wnt/β-catenin signaling for tumor progression in the context of acquired KRAS and other mutations is less well-established. To attenuate Wnt/β-catenin signaling in tumors, we have developed potent and specific small-molecule tankyrase inhibitors, G007-LK and G244-LM, that reduce Wnt/β-catenin signaling by preventing poly(ADP-ribosyl)ation-dependent AXIN degradation, thereby promoting β-catenin destabilization. We show that novel tankyrase inhibitors completely block ligand-driven Wnt/β-catenin signaling in cell culture and display approximately 50% inhibition of APC mutation-driven signaling in most CRC cell lines. It was previously unknown whether the level of AXIN protein stabilization by tankyrase inhibition is sufficient to impact tumor growth in the absence of normal APC activity. Compound G007-LK displays favorable pharmacokinetic properties and inhibits in vivo tumor growth in a subset of APC-mutant CRC xenograft models. In the xenograft model most sensitive to tankyrase inhibitor, COLO-320DM, G007-LK inhibits cell-cycle progression, reduces colony formation, and induces differentiation, suggesting that β-catenin-dependent maintenance of an undifferentiated state may be blocked by tankyrase inhibition. The full potential of the antitumor activity of G007-LK may be limited by intestinal toxicity associated with inhibition of Wnt/β-catenin signaling and cell proliferation in intestinal crypts. These results establish proof-of-concept antitumor efficacy for tankyrase inhibitors in APC-mutant CRC models and uncover potential diagnostic and safety concerns to be overcome as tankyrase inhibitors are advanced into the clinic. PMID:23539443

  18. Abacavir/lamivudine versus tenofovir/emtricitabine in virologically suppressed patients switching from ritonavir-boosted protease inhibitors to raltegravir.

    PubMed

    Martínez, Esteban; d'Albuquerque, Polyana M; Pérez, Ignacio; Pich, Judit; Gatell, José M

    2013-02-01

    There are few clinical data on the combination abacavir/lamivudine plus raltegravir. We compared the outcomes of patients from the SPIRAL trial receiving either abacavir/lamivudine or tenofovir/emtricitabine at baseline who had taken at least one dose of either raltegravir or ritonavir-boosted protease inhibitors. For the purpose of this analysis, treatment failure was defined as virological failure (confirmed HIV-1 RNA ≥50 copies/ml) or discontinuation of abacavir/lamivudine or tenofovir/emtricitabine because of adverse events, consent withdrawal, or lost to follow-up. There were 143 (72.59%) patients with tenofovir/emtricitabine and 54 (27.41%) with abacavir/lamivudine. In the raltegravir group, there were three (11.11%) treatment failures with abacavir/lamivudine and eight (10.96%) with tenofovir/emtricitabine (estimated difference 0.15%; 95% CI -17.90 to 11.6). In the ritonavir-boosted protease inhibitor group, there were four (14.81%) treatment failures with abacavir/lamivudine and 12 (17.14%) with tenofovir/emtricitabine (estimated difference -2.33%; 95% CI -16.10 to 16.70). Triglycerides decreased and HDL cholesterol increased through the study more pronouncedly with abacavir/lamivudine than with tenofovir/emtricitabine and differences in the total-to-HDL cholesterol ratio between both combinations of nucleoside reverse transcriptase inhibitors (NRTIs) tended to be higher in the raltegravir group, although differences at 48 weeks were not significant. While no patient discontinued abacavir/lamivudine due to adverse events, four (2.80%) patients (all in the ritonavir-boosted protease inhibitor group) discontinued tenofovir/emtricitabine because of adverse events (p=0.2744). The results of this analysis do not suggest that outcomes of abacavir/lamivudine are worse than those of tenofovir/emtricitabine when combined with raltegravir in virologically suppressed HIV-infected adults. PMID:22916715

  19. An iminosugar-based heparanase inhibitor heparastatin (SF4) suppresses infiltration of neutrophils and monocytes into inflamed dorsal air pouches.

    PubMed

    Sue, Mayumi; Higashi, Nobuaki; Shida, Hiroaki; Kogane, Yusuke; Nishimura, Yoshio; Adachi, Hayamitsu; Kolaczkowska, Elzbieta; Kepka, Magdalena; Nakajima, Motowo; Irimura, Tatsuro

    2016-06-01

    Local infiltration of inflammatory cells is regulated by a number of biological steps during which the cells likely penetrate through subendothelial basement membranes that contain heparan sulfate proteoglycans. In the present study, we examined whether administration of heparastatin (SF4), an iminosugar-based inhibitor of heparanase, could suppress local inflammation and degradation of heparan sulfate proteoglycans in basement membranes. In a carrageenan- or formyl peptide-induced dorsal air pouch inflammation model, the number of infiltrated neutrophils and monocytes was significantly lower in mice after topical administration of heparastatin (SF4). The concentration of chemokines MIP-2 and KC in pouch exudates of drug-treated mice was similar to control. In a zymosan-induced peritonitis model, the number of infiltrated cells was not altered in drug-treated mice. To further test how heparastatin (SF4) influences transmigration of inflammatory neutrophils, its suppressive effect on migration and matrix degradation was examined in vitro. In the presence of heparastatin (SF4), the number of neutrophils that infiltrated across a Matrigel-coated polycarbonate membrane was significantly lower, while the number of neutrophils passing through an uncoated membrane was not altered. Lysate of bone marrow-derived neutrophils released sulfate-radiolabeled macromolecules from basement membrane-like extracellular matrix, which was suppressed by heparastatin (SF4). Heparan sulfate degradation activity was almost completely abolished after incubation of lysate with protein G-conjugated anti-heparanase monoclonal antibody, strongly suggesting that the activity was due to heparanase-mediated degradation. Taken together, in a dorsal air pouch inflammation model heparastatin (SF4) potentially suppresses extravasation of inflammatory cells by impairing the degradation of basement membrane heparan sulfate. PMID:27015605

  20. The monoacylglycerol lipase inhibitor JZL184 suppresses inflammatory pain in the mouse carrageenan model

    PubMed Central

    Ghosh, Sudeshna; Wise, Laura E.; Chen, Yugang; Gujjar, Ramesh; Mahadevan, Anu; Cravatt, Benjamin F.; Lichtman, Aron H.

    2013-01-01

    Aim The present study tested whether the selective monoacylglycerol lipase (MAGL) inhibitor JZL184 would reduce allodynia and paw edema in the carrageenan test. Main methods The anti-edematous and anti-allodynic effects of JZL184 were compared to those of PF-3845, an inhibitor of fatty acid amide hydrolase (FAAH), and diclofenac, a non-selective cyclooxygenase inhibitor. Cannabinoid receptor involvement in the anti-edematous and anti-allodynic effects of JZL184 was evaluated by administration of the respective CB1 and CB2 receptor antagonists rimonabant and SR144528 as well as with CB1(−/−) and CB2(−/−) mice. JZL184 (1.6, 4, 16, or 40 mg/kg) was administered for six days to assess tolerance. Key findings JZL184 administered before or after carrageenan significantly attenuated carrageenan-induced paw edema and mechanical allodynia. Complementary genetic and pharmacological approaches revealed that the anti-allodynic effects of JZL184 required both CB1 and CB2 receptors, but only CB2 receptors mediated its anti-edematous actions. Importantly, both the anti-edematous and anti-allodynic effects underwent tolerance following repeated injections of high dose JZL184 (16 or 40 mg/kg), but repeated administration of low dose JZL184 (4 mg/kg) retained efficacy. Significance These results suggest that the MAGL inhibitor JZL184 reduces inflammatory nociception through the activation of both CB1 and CB2 receptors, with no evidence of tolerance following repeated administration of low doses. PMID:22749865

  1. Protease inhibitors suppress the survival increase mediated by uncouplers in X-irradiated mammalian cells.

    PubMed

    Michel, S; Laval, F

    1982-01-01

    When mammalian cells are incubated with an uncoupler of oxidative phosphorylation prior to and during X-irradiation, the survival and the mutation frequency are markedly increased. This process requires protein synthesis and is inhibited when the cells are plated in the presence of a protease inhibitor (antipain or leupeptin). These results suggest the existence of an error-prone DNA repair process in X-irradiated mammalian cells. PMID:6814524

  2. Suppression of cytochrome P450 3A protein levels by proteasome inhibitors.

    SciTech Connect

    Zangar, Richard C. ); Kocarek, Thomas A.; Shen, Shang; Bollinger, Nikki ); Dahn, Michael S.; Lee, Donna W.

    2003-06-01

    We have previously reported that CYP3A cross-links with polyubiquitinated proteins in microsomes from nicardipine-treated rats in a process that is distinct from classical polyubiquitination. To further examine the role of the proteasome in CYP3A degradation, we investigated the effects of proteasome inhibitors lactacystin, MG132, proteasome inhibitor 1, and hemin in primary cultures of rat and human hepatocytes. With the exception of hemin, these agents increased the total pool of ubiquitinated proteins in microsomes isolated from rat hepatocytes, indicating that lactacystin, MG132, and proteasome inhibitor 1 effectively inhibited the proteasome in these cells. All four agents caused a reduction in the amount of the major approximately 55-kDa CYP3A band, opposite to what would be expected if the ubiquitin-proteasome pathway degraded CYP3A. Only hemin treatment caused an increase in high molecular mass (HMM) CYP3A bands. Because hemin treatment did not alter levels of ubiquitin in CYP3 A immunoprecipitates, the HMM CYP3A bands formed in response to hemin treatment clearly were not due to proteasome inhibition. Rather, because hemin treatment also caused an increase in HMM CYP3A in the detergent-insoluble fraction of the 10,000g pellet, the HMM CYP3A seems to represent a large protein complex that is unlikely to primarily represent ubiquitination.

  3. A novel role for the apoptosis inhibitor ARC in suppressing TNFα-induced regulated necrosis.

    PubMed

    Kung, G; Dai, P; Deng, L; Kitsis, R N

    2014-04-01

    TNFα signaling can promote apoptosis or a regulated form of necrosis. ARC (apoptosis repressor with CARD (caspase recruitment domain)) is an endogenous inhibitor of apoptosis that antagonizes both the extrinsic (death receptor) and intrinsic (mitochondrial/ER) apoptosis pathways. We discovered that ARC blocks not only apoptosis but also necrosis. TNFα-induced necrosis was abrogated by overexpression of wild-type ARC but not by a CARD mutant that is also defective for inhibition of apoptosis. Conversely, knockdown of ARC exacerbated TNFα-induced necrosis, an effect that was rescued by reconstitution with wild-type, but not CARD-defective, ARC. Similarly, depletion of ARC in vivo exacerbated necrosis caused by infection with vaccinia virus, which elicits severe tissue damage through this pathway, and sensitized mice to TNFα-induced systemic inflammatory response syndrome. The mechanism underlying these effects is an interaction of ARC with TNF receptor 1 that interferes with recruitment of RIP1, a critical mediator of TNFα-induced regulated necrosis. These findings extend the role of ARC from an apoptosis inhibitor to a regulator of the TNFα pathway and an inhibitor of TNFα-mediated regulated necrosis. PMID:24440909

  4. Epigenetic suppression of the antitumor cytotoxicity of NK cells by histone deacetylase inhibitor valproic acid

    PubMed Central

    Shi, Xiumin; Li, Min; Cui, Meizi; Niu, Chao; Xu, Jianting; Zhou, Lei; Li, Wei; Gao, Yushun; Kong, Weisheng; Cui, Jiuwei; Hu, Jifan; Jin, Haofan

    2016-01-01

    Natural killer (NK) cells play an essential role in the fight against tumor development. The therapeutic use of autologous NK cells has been exploited to treat human malignancies, yet only limited antitumor activity is observed in cancer patients. In this study, we sought to augment the antitumor activity of NK cells using epigenetic approaches. Four small molecules that have been known to promote epigenetic reprogramming were tested for their ability to enhance the activity of NK cells. Using a tumor cell lysis assay, we found that the DNA demethylating agent 5-azacytidine and vitamin C did not significantly affect the tumor killing ability of NK cells. The thyroid hormone triiodothyronine (T3) slightly increased the activity of NK cells. The histone deacetylase inhibitor valproic acid (VPA), however, inhibited NK cell lytic activity against leukemic cells in a dose-dependent manner. Pretreatment using VPA reduced IFNγ secretion, impaired CD107a degranulation, and induced apoptosis by activating the PD-1/PD-L1 pathway. VPA downregulated the expression of the activating receptor NKG2D (natural-killer group 2, member D) by inducing histone K9 hypermethylation and DNA methylation in the gene promoter. Histone deacetylase inhibitors have been developed as anticancer agents for use as monotherapies or in combination with other anticancer therapies. Our data suggest that the activity of histone deacetylase inhibitors on NK cell activity should be considered in drug development. PMID:27152238

  5. Ex vivo expanded autologous polyclonal regulatory T cells suppress inhibitor formation in hemophilia

    PubMed Central

    Sarkar, Debalina; Biswas, Moanaro; Liao, Gongxian; Seay, Howard R; Perrin, George Q; Markusic, David M; Hoffman, Brad E; Brusko, Todd M; Terhorst, Cox; Herzog, Roland W

    2014-01-01

    Adoptive cell therapy utilizing ex vivo expanded polyclonal CD4+CD25+FOXP3+ regulatory T cells (Treg) is in use in clinical trials for the treatment of type 1 diabetes and prevention of graft versus host disease in bone marrow transplantation. Here, we seek to evaluate this approach in the treatment of inherited protein deficiencies, i.e., hemophilia, which is often complicated by antibody formation against the therapeutic protein. Treg from mice that express green fluorescent protein–marked FoxP3 were highly purified by two-step magnetic/flow sorting and ex vivo expanded 50- to 100-fold over a 2-week culture period upon stimulation with antibody-coated microbeads. FoxP3 expression was maintained in >80% of expanded Treg, which also expressed high levels of CD62L and CTLA-4. Transplanted Treg suppressed inhibitory antibody formation against coagulation factors VIII and IX in protein and gene therapies in strain-matched hemophilia A and B mice, including in mice with pre-existing antibodies. Although transplanted Treg became undetectable within 2 weeks, suppression persisted for >2 months. Additional studies suggested that antigen-specific suppression emerged due to induction of endogenous Treg. The outcomes of these studies support the concept that cell therapy with ex vivo expanded autologous Treg can be used successfully to minimize immune responses in gene and protein replacement therapies. PMID:25364772

  6. miR-17 inhibitor suppressed osteosarcoma tumor growth and metastasis via increasing PTEN expression

    SciTech Connect

    Gao, Yong; Luo, Ling-hui; Li, Shuai; Yang, Cao

    2014-02-07

    Highlights: • miR-17 was increased in OS tissues and cell lines. • Inhibition of miR-17 suppressed OS cell proliferation. • Inhibition of miR-17 suppressed OS cell migration and invasion. • PTEN was a target of miR-17. • miR-17 was negatively correlated with PTEN in OS tissues. - Abstract: MicroRNAs (miRNAs) play essential roles in cancer development and progression. Here, we investigated the role of miR-17 in the progression and metastasis of osteosarcoma (OS). miR-17 was frequently increased in OS tissues and cell lines. Inhibition of miR-17 in OS cell lines substantially suppressed cell proliferation, migration, and invasion. Phosphatase and tensin homolog (PTEN) was identified as a target of miR-17, and ectopic expression of miR-17 inhibited PTEN by direct binding to its 3′-untranslated region (3′-UTR). Expression of miR-17 was negatively correlated with PTEN in OS tissues. Together, these findings indicate that miR-17 acts as an oncogenic miRNA and may contribute to the progression and metastasis of OS, suggesting miR-17 as a potential novel diagnostic and therapeutic target of OS.

  7. Formation of embryogenic cell clumps from carrot epidermal cells is suppressed by 5-azacytidine, a DNA methylation inhibitor.

    PubMed

    Yamamoto, Nozomi; Kobayashi, Hatsumi; Togashi, Takashi; Mori, Yukiko; Kikuchi, Koji; Kuriyama, Kyoko; Tokuji, Yoshihiko

    2005-01-01

    Using a direct somatic embryogenesis system in carrot, we examined the role of DNA methylation in the change of cellular differentiation state, from somatic to embryogenic. 5-Azacytidine (aza-C), an inhibitor of DNA methylation suppressed the formation of embryogenic cell clumps from epidermal carrot cells. Aza-C also downregulated the expression of DcLEC1c, a LEC1-like embryonic gene in carrot, during morphogenesis of embryos. A carrot DNA methyltransferase gene, Met1-5 was expressed transiently after the induction of somatic embryogenesis by 2,4-dichlorophenoxyacetic acid (2,4-D), before the formation of embryogenic cell clumps. These findings suggested the significance of DNA methylation in acquiring the embryogenic competence in somatic cells in carrot. PMID:15700420

  8. Suppression of Neurotensin Receptor Type 1 Expression and Function by Histone Deacetylase Inhibitors in Human Colorectal Cancers*

    PubMed Central

    Wang, Xiaofu; Jackson, Lindsey N.; Johnson, Sara M.; Wang, Qingding; Evers, B. Mark

    2010-01-01

    Neurotensin (NT), a gut peptide, stimulates growth of colorectal cancers (CRCs) which possess the high affinity NT receptor (NTR1). Sodium butyrate (NaBT) is a potent histone deacetylase inhibitor (HDACi) which induces growth arrest, differentiation and apoptosis of CRCs. Previously, we showed that NaBT increases nuclear GSK-3β expression and kinase activity; GSK-3β functions as a negative regulator of ERK signaling. The purpose of our current study was to determine: (a) whether HDACi alters NTR1 expression and function, and (b) the role of GSK-3β/ERK in NTR1 regulation. Human CRCs with NTR1 were treated with various HDACi and NTR1 expression and function were assessed. Treatment with HDACi dramatically decreased endogenous NTR1 mRNA, protein and promoter activity. Overexpression of GSK-3β decreased NTR1 promoter activity (> 30%); inhibition of GSK-3β increased NTR1 expression in CRC cells, indicating that GSK-3β is a negative regulator of ERK and NTR1. Consistent with our previous findings, HDACi significantly decreased phosphorylated ERK while increasing GSK-3β. Selective MEK/ERK inhibitors suppressed NTR1 mRNA expression in a time- and dose-dependent fashion, and reduced NTR1 promoter activity by ~70%. Finally, pretreatment with NaBT prevented NT-mediated COX-2 and c-myc expression and attenuated NT-induced IL-8 expression. HDACi suppresses endogenous NTR1 expression and function in CRC cell lines; this effect is mediated through, at least in part, the GSK-3β/ERK pathway. The down-regulation of NTR1 in CRCs may represent an important mechanism for the anti-cancer effects of HDACi. PMID:20663927

  9. Hypouricemic effects of novel concentrative nucleoside transporter 2 inhibitors through suppressing intestinal absorption of purine nucleosides.

    PubMed

    Hiratochi, Masahiro; Tatani, Kazuya; Shimizu, Kazuo; Kuramochi, Yu; Kikuchi, Norihiko; Kamada, Noboru; Itoh, Fumiaki; Isaji, Masayuki

    2012-09-01

    We have developed concentrative nucleoside transporter 2 (CNT2) inhibitors as a novel pharmacological approach for improving hyperuricemia by inhibiting intestinal absorption of purines. Dietary purine nucleosides are absorbed in the small intestines by CNTs expressed in the apical membrane. In humans, the absorbed purine nucleosides are rapidly degraded to their final end product, uric acid, by xanthine oxidase. Based on the expression profile of human CNTs in digestive tract tissues, we established a working hypothesis that mainly CNT2 contributes to the intestinal absorption of purine nucleosides. In order to confirm this possibility, we developed CNT2 inhibitors and found that (2R,3R,4S,5R)-2-(6-amino-8-{[3'-(3-aminopropoxy)-biphenyl-4-ylmethyl]-amino}-9H-purin-9-yl)-5-hydroxymethyl-tetrahydrofuran-3,4-diol (KGO-2142) and 1-[3-(5-{[1-((2R,3R,4S,5R)-3,4-dihydroxy-5-hydroxymethyl-tetrahydrofuran-2-yl)-1H-benzimidazol-2-ylamino]-methyl}-2-ethoxyphenoxy)-propyl]-piperidine-4-carboxylic acid amide (KGO-2173) were inhibitory. These CNT2 inhibitors had potent inhibitory activity against inosine uptake via human CNT2, but they did not potently interfere with nucleoside uptake via human CNT1, CNT3 or equilibrative nucleoside transporters (ENTs) in vitro. After oral administration of KGO-2173 along with [(14)C]-inosine, KGO-2173 significantly decreased the urinary excretion of radioactivity at 6 and 24h in rats. Since dietary purine nucleosides are not utilized in the body and are excreted into the urine rapidly, this decrease in radioactivity in the urine represented the inhibitory activity of KGO-2173 toward the absorption of [(14)C]-inosine in the small intestines. KGO-2142 almost completely inhibited dietary RNA-induced hyperuricemia and the increase in urinary excretion of uric acid in cebus monkeys. These novel CNT2 inhibitors, KGO-2142 and KGO-2173, could be useful therapeutic options for the treatment of hyperuricemia. PMID:22709993

  10. Multiple CDK inhibitor dinaciclib suppresses neuroblastoma growth via inhibiting CDK2 and CDK9 activity

    PubMed Central

    Chen, Zhenghu; Wang, Zhenyu; Pang, Jonathan C.; Yu, Yang; Bieerkehazhi, Shayahati; Lu, Jiaxiong; Hu, Ting; Zhao, Yanling; Xu, Xin; Zhang, Hong; Yi, Joanna S.; Liu, Shangfeng; Yang, Jianhua

    2016-01-01

    Neuroblastoma (NB), the most common extracranial solid tumor of childhood, is responsible for approximately 15% of cancer-related mortality in children. Aberrant activation of cyclin-dependent kinases (CDKs) has been shown to contribute to tumor cell progression in many cancers including NB. Therefore, small molecule inhibitors of CDKs comprise a strategic option in cancer therapy. Here we show that a novel multiple-CDK inhibitor, dinaciclib (SCH727965, MK-7965), exhibits potent anti-proliferative effects on a panel of NB cell lines by blocking the activity of CDK2 and CDK9. Dinaciclib also significantly sensitized NB cell lines to the treatment of chemotherapeutic agents such as doxorubicin (Dox) and etoposide (VP-16). Furthermore, dinaciclib revealed in vivo antitumor efficacy in an orthotopic xenograft mouse model of two NB cell lines and blocked tumor development in the TH-MYCN transgenic NB mouse model. Taken together, this study suggests that CDK2 and CDK9 are potential therapeutic targets in NB and that abrogating CDK2 and CDK9 activity by small molecules like dinaciclib is a promising strategy and a treatment option for NB patients. PMID:27378523

  11. Inhibitors of Endoplasmic Reticulum α-Glucosidases Potently Suppress Hepatitis C Virus Virion Assembly and Release▿

    PubMed Central

    Qu, Xiaowang; Pan, Xiaoben; Weidner, Jessica; Yu, Wenquan; Alonzi, Dominic; Xu, Xiaodong; Butters, Terry; Block, Timothy; Guo, Ju-Tao; Chang, Jinhong

    2011-01-01

    α-Glucosidases I and II are endoplasmic reticulum-resident enzymes that are essential for N-linked glycan processing and subsequent proper folding of glycoproteins. In this report, we first demonstrate that downregulation of the expression of α-glucosidase I, II, or both in Huh7.5 cells by small hairpin RNA technology inhibited the production of hepatitis C virus (HCV). In agreement with the essential role of α-glucosidases in HCV envelope glycoprotein processing and folding, treatment of HCV-infected cells with a panel of imino sugar derivatives, which are competitive inhibitors of α-glucosidases, did not affect intracellular HCV RNA replication and nonstructural protein expression but resulted in the inhibition of glycan processing and subsequent degradation of HCV E2 glycoprotein. As a consequence, HCV virion assembly and secretion were inhibited. In searching for imino sugars with better antiviral activity, we found that a novel imino sugar, PBDNJ0804, had a superior ability to inhibit HCV virion assembly and secretion. In summary, we demonstrated that glucosidases are important host factor-based antiviral targets for HCV infection. The low likelihood of drug-resistant virus emergence and potent antiviral efficacy of the novel glucosidase inhibitor hold promise for its development as a therapeutic agent for the treatment of chronic hepatitis C. PMID:21173177

  12. The xanthine oxidase inhibitor febuxostat suppresses development of nonalcoholic steatohepatitis in a rodent model.

    PubMed

    Nakatsu, Yusuke; Seno, Yasuyuki; Kushiyama, Akifumi; Sakoda, Hideyuki; Fujishiro, Midori; Katasako, Aya; Mori, Keiichi; Matsunaga, Yasuka; Fukushima, Toshiaki; Kanaoka, Ryuhei; Yamamotoya, Takeshi; Kamata, Hideaki; Asano, Tomoichiro

    2015-07-01

    Xanthine oxidase (XO) is an enzyme involved in the production of uric acid (UA) from purine nucleotides. Numerous recent studies have revealed the likelihood of metabolic syndrome including nonalcoholic fatty liver disease (NAFLD) or steatohepatitis (NASH) to be related to hyperuricemia. However, it remains unclear whether elevated serum UA during the development of NAFLD or NASH is a cause or a consequence of these diseases. In this study, the XO inhibitor febuxostat was administered to two types of NASH model mice. Febuxostat exerted a strong protective effect against NASH development induced by a high-fat diet containing trans fatty acid (HFDT). In contrast, methionine choline-deficient-diet-induced NASH development not accompanied by hyperuricemia showed no UA normalization, suggesting that the ameliorating effect of febuxostat occurs via the normalization of hyperuricemia itself and/or accompanying molecular mechanism(s) such as oxidative stress. In the HFDT-fed mice, hyperuricemia, elevated alanine aminotransferase, and increased Tunnel-positive cells in the liver were normalized by febuxostat administration. In addition, upregulation of fatty acid oxidation-related genes, fibrotic change, and increases in collagen deposition, inflammatory cytokine expressions, and lipid peroxidation in the HFDT-fed mice were also normalized by febuxostat administration. Taken together, these observations indicate that administration of febuxostat has a protective effect against HFDT-induced NASH development, suggesting the importance of XO in its pathogenesis. Thus XO inhibitors are potentially potent therapies for patients with NASH, particularly that associated with hyperuricemia. PMID:25999428

  13. CBP30, a selective CBP/p300 bromodomain inhibitor, suppresses human Th17 responses

    PubMed Central

    Hammitzsch, Ariane; Tallant, Cynthia; Fedorov, Oleg; O’Mahony, Alison; Brennan, Paul E.; Hay, Duncan A.; Martinez, Fernando O.; Al-Mossawi, M. Hussein; de Wit, Jelle; Vecellio, Matteo; Wells, Christopher; Wordsworth, Paul; Müller, Susanne; Knapp, Stefan; Bowness, Paul

    2015-01-01

    Th17 responses are critical to a variety of human autoimmune diseases, and therapeutic targeting with monoclonal antibodies against IL-17 and IL-23 has shown considerable promise. Here, we report data to support selective bromodomain blockade of the transcriptional coactivators CBP (CREB binding protein) and p300 as an alternative approach to inhibit human Th17 responses. We show that CBP30 has marked molecular specificity for the bromodomains of CBP and p300, compared with 43 other bromodomains. In unbiased cellular testing on a diverse panel of cultured primary human cells, CBP30 reduced immune cell production of IL-17A and other proinflammatory cytokines. CBP30 also inhibited IL-17A secretion by Th17 cells from healthy donors and patients with ankylosing spondylitis and psoriatic arthritis. Transcriptional profiling of human T cells after CBP30 treatment showed a much more restricted effect on gene expression than that observed with the pan-BET (bromo and extraterminal domain protein family) bromodomain inhibitor JQ1. This selective targeting of the CBP/p300 bromodomain by CBP30 will potentially lead to fewer side effects than with the broadly acting epigenetic inhibitors currently in clinical trials. PMID:26261308

  14. Dual mTOR inhibitor MLN0128 suppresses Merkel cell carcinoma (MCC) xenograft tumor growth

    PubMed Central

    Kannan, Aarthi; Lin, Zhenyu; Shao, Qiang; Zhao, Stephanie; Fang, Bin; Moreno, Mauricio A.; Vural, Emre; Stack, Brendan C.; Suen, James Y.; Kannan, Krishnaswamy; Gao, Ling

    2016-01-01

    Merkel cell carcinoma (MCC) is an aggressive neuroendocrine skin cancer. Pathologic activation of PI3K/mTOR pathway and elevated expression of c-Myc are frequently detected in MCC. Yet, there is no targeted therapy presently available for this lethal disease. Recently, MLN0128, a second-generation dual TORC1/2 inhibitor is shown to have therapeutic efficacy in preclinical studies. MLN0128 is currently in clinical trials as a potential therapy for advanced cancers. Here we characterize the therapeutic efficacy of MLN0128 in the preclinical setting of MCC and delineate downstream targets of mTORC1/2 in MCC cellular systems. MLN0128 significantly attenuates xenograft MCC tumor growth independent of Merkel cell polyomavirus. Moreover, MLN0128 markedly diminishes MCC cell proliferation and induces apoptosis. Further investigations indicate that senescence does not contribute to MLN0128-mediated repression of xenograft MCC tumor growth. Finally, we also observe robust antitumor effects of MLN0128 when administered as a dual therapy with JQ1, a bromodomain protein BRD4 inhibitor. These results suggest dual blockade of PI3K/mTOR pathway and c-Myc axis is effective in the control of MCC tumor growth. Our results demonstrate that MLN0128 is potent as monotherapy or as a member of combination therapy with JQ1 for advanced MCC. PMID:26536665

  15. Multiple CDK inhibitor dinaciclib suppresses neuroblastoma growth via inhibiting CDK2 and CDK9 activity.

    PubMed

    Chen, Zhenghu; Wang, Zhenyu; Pang, Jonathan C; Yu, Yang; Bieerkehazhi, Shayahati; Lu, Jiaxiong; Hu, Ting; Zhao, Yanling; Xu, Xin; Zhang, Hong; Yi, Joanna S; Liu, Shangfeng; Yang, Jianhua

    2016-01-01

    Neuroblastoma (NB), the most common extracranial solid tumor of childhood, is responsible for approximately 15% of cancer-related mortality in children. Aberrant activation of cyclin-dependent kinases (CDKs) has been shown to contribute to tumor cell progression in many cancers including NB. Therefore, small molecule inhibitors of CDKs comprise a strategic option in cancer therapy. Here we show that a novel multiple-CDK inhibitor, dinaciclib (SCH727965, MK-7965), exhibits potent anti-proliferative effects on a panel of NB cell lines by blocking the activity of CDK2 and CDK9. Dinaciclib also significantly sensitized NB cell lines to the treatment of chemotherapeutic agents such as doxorubicin (Dox) and etoposide (VP-16). Furthermore, dinaciclib revealed in vivo antitumor efficacy in an orthotopic xenograft mouse model of two NB cell lines and blocked tumor development in the TH-MYCN transgenic NB mouse model. Taken together, this study suggests that CDK2 and CDK9 are potential therapeutic targets in NB and that abrogating CDK2 and CDK9 activity by small molecules like dinaciclib is a promising strategy and a treatment option for NB patients. PMID:27378523

  16. Proteomic analysis reveals suppression of bark chitinases and proteinase inhibitors in citrus plants affected by the citrus sudden death disease.

    PubMed

    Cantú, M D; Mariano, A G; Palma, M S; Carrilho, E; Wulff, N A

    2008-10-01

    Citrus sudden death (CSD) is a disease of unknown etiology that greatly affects sweet oranges grafted on Rangpur lime rootstock, the most important rootstock in Brazilian citriculture. We performed a proteomic analysis to generate information related to this plant pathogen interaction. Protein profiles from healthy, CSD-affected and CSD-tolerant stem barks, were generated using two-dimensional gel electrophoresis. The protein spots were well distributed over a pI range of 3.26 to 9.97 and a molecular weight (MW) range from 7.1 to 120 kDa. The patterns of expressed proteins on 2-DE gels made it possible to distinguish healthy barks from CSD-affected barks. Protein spots with MW around 30 kDa and pI values ranging from 4.5 to 5.2 were down-regulated in the CSD-affected root-stock bark. This set of protein spots was identified as chitinases. Another set of proteins, ranging in pI from 6.1 to 9.6 with an MW of about 20 kDa, were also suppressed in CSD-affected rootstock bark; these were identified as miraculin-like proteins, potential trypsin inhibitors. Down-regulation of chitinases and proteinase inhibitors in CSD-affected plants is relevant since chitinases are well-known pathogenesis-related protein, and their activity against plant pathogens is largely accepted. PMID:18943454

  17. Proteasome Inhibitor Bortezomib Suppresses Nuclear Factor-Kappa B Activation and Ameliorates Eye Inflammation in Experimental Autoimmune Uveitis

    PubMed Central

    Hsu, Sheng-Min; Yang, Chang-Hao; Shen, Fang-Hsiu; Chen, Shun-Hua; Lin, Chia-Jhen; Shieh, Chi-Chang

    2015-01-01

    Bortezomib is a proteasome inhibitor used for hematologic cancer treatment. Since it can suppress NF-κB activation, which is critical for the inflammatory process, bortezomib has been found to possess anti-inflammatory activity. In this study, we evaluated the effect of bortezomib on experimental autoimmune uveitis (EAU) in mice and investigated the potential mechanisms related to NF-κB inactivation. High-dose bortezomib (0.75 mg/kg), low-dose bortezomib (0.15 mg/kg), or phosphate buffered saline was given after EAU induction. We found that the EAU is ameliorated by high-dose bortezomib treatment when compared with low-dose bortezomib or PBS treatment. The DNA-binding activity of NF-κB was suppressed and expression of several key inflammatory mediators including TNF-α, IL-1α, IL-1β, IL-12, IL-17, and MCP-1 was lowered in the high-dose bortezomib-treated group. These results suggest that proteasome inhibition is a promising treatment strategy for autoimmune uveitis. PMID:25653480

  18. Antibiotic monensin synergizes with EGFR inhibitors and oxaliplatin to suppress the proliferation of human ovarian cancer cells.

    PubMed

    Deng, Youlin; Zhang, Junhui; Wang, Zhongliang; Yan, Zhengjian; Qiao, Min; Ye, Jixing; Wei, Qiang; Wang, Jing; Wang, Xin; Zhao, Lianggong; Lu, Shun; Tang, Shengli; Mohammed, Maryam K; Liu, Hao; Fan, Jiaming; Zhang, Fugui; Zou, Yulong; Liao, Junyi; Qi, Hongbo; Haydon, Rex C; Luu, Hue H; He, Tong-Chuan; Tang, Liangdan

    2015-01-01

    Ovarian cancer is the most lethal gynecologic malignancy with an overall cure rate of merely 30%. Most patients experience recurrence within 12-24 months of cure and die of progressively chemotherapy-resistant disease. Thus, more effective anti-ovarian cancer therapies are needed. Here, we investigate the possibility of repurposing antibiotic monensin as an anti-ovarian cancer agent. We demonstrate that monensin effectively inhibits cell proliferation, migration and cell cycle progression, and induces apoptosis of human ovarian cancer cells. Monensin suppresses multiple cancer-related pathways including Elk1/SRF, AP1, NFκB and STAT, and reduces EGFR expression in ovarian cancer cells. Monensin acts synergistically with EGFR inhibitors and oxaliplatin to inhibit cell proliferation and induce apoptosis of ovarian cancer cells. Xenograft studies confirm that monensin effectively inhibits tumor growth by suppressing cell proliferation through targeting EGFR signaling. Our results suggest monensin may be repurposed as an anti-ovarian cancer agent although further preclinical and clinical studies are needed. PMID:26639992

  19. Suppression of Tumor Growth in Mice by Rationally Designed Pseudopeptide Inhibitors of Fibroblast Activation Protein and Prolyl Oligopeptidase1

    PubMed Central

    Jackson, Kenneth W.; Christiansen, Victoria J.; Yadav, Vivek R.; Silasi-Mansat, Robert; Lupu, Florea; Awasthi, Vibhudutta; Zhang, Roy R.; McKee, Patrick A.

    2015-01-01

    Tumor microenvironments (TMEs) are composed of cancer cells, fibroblasts, extracellular matrix, microvessels, and endothelial cells. Two prolyl endopeptidases, fibroblast activation protein (FAP) and prolyl oligopeptidase (POP), are commonly overexpressed by epithelial-derived malignancies, with the specificity of FAP expression by cancer stromal fibroblasts suggesting FAP as a possible therapeutic target. Despite overexpression in most cancers and having a role in angiogenesis, inhibition of POP activity has received little attention as an approach to quench tumor growth. We developed two specific and highly effective pseudopeptide inhibitors, M83, which inhibits FAP and POP proteinase activities, and J94, which inhibits only POP. Both suppressed human colon cancer xenograft growth > 90% in mice. By immunohistochemical stains, M83- and J94-treated tumors had fewer microvessels, and apoptotic areas were apparent in both. In response to M83, but not J94, disordered collagen accumulations were observed. Neither M83- nor J94-treated mice manifested changes in behavior, weight, or gastrointestinal function. Tumor growth suppression was more extensive than noted with recently reported efforts by others to inhibit FAP proteinase function or reduce FAP expression. Diminished angiogenesis and the accompanying profound reduction in tumor growth suggest that inhibition of either FAP or POP may offer new therapeutic approaches that directly target TMEs. PMID:25622898

  20. Antibiotic monensin synergizes with EGFR inhibitors and oxaliplatin to suppress the proliferation of human ovarian cancer cells

    PubMed Central

    Deng, Youlin; Zhang, Junhui; Wang, Zhongliang; Yan, Zhengjian; Qiao, Min; Ye, Jixing; Wei, Qiang; Wang, Jing; Wang, Xin; Zhao, Lianggong; Lu, Shun; Tang, Shengli; Mohammed, Maryam K.; Liu, Hao; Fan, Jiaming; Zhang, Fugui; Zou, Yulong; Liao, Junyi; Qi, Hongbo; Haydon, Rex C.; Luu, Hue H.; He, Tong-Chuan; Tang, Liangdan

    2015-01-01

    Ovarian cancer is the most lethal gynecologic malignancy with an overall cure rate of merely 30%. Most patients experience recurrence within 12–24 months of cure and die of progressively chemotherapy-resistant disease. Thus, more effective anti-ovarian cancer therapies are needed. Here, we investigate the possibility of repurposing antibiotic monensin as an anti-ovarian cancer agent. We demonstrate that monensin effectively inhibits cell proliferation, migration and cell cycle progression, and induces apoptosis of human ovarian cancer cells. Monensin suppresses multiple cancer-related pathways including Elk1/SRF, AP1, NFκB and STAT, and reduces EGFR expression in ovarian cancer cells. Monensin acts synergistically with EGFR inhibitors and oxaliplatin to inhibit cell proliferation and induce apoptosis of ovarian cancer cells. Xenograft studies confirm that monensin effectively inhibits tumor growth by suppressing cell proliferation through targeting EGFR signaling. Our results suggest monensin may be repurposed as an anti-ovarian cancer agent although further preclinical and clinical studies are needed. PMID:26639992

  1. Oncogenic roles of TOPK and MELK, and effective growth suppression by small molecular inhibitors in kidney cancer cells

    PubMed Central

    Kato, Taigo; Inoue, Hiroyuki; Imoto, Seiya; Tamada, Yoshinori; Miyamoto, Takashi; Matsuo, Yo; Nakamura, Yusuke; Park, Jae-Hyun

    2016-01-01

    T–lymphokine-activated killer cell–originated protein kinase (TOPK) and maternal embryonic leucine zipper kinase (MELK) have been reported to play critical roles in cancer cell proliferation and maintenance of stemness. In this study, we investigated possible roles of TOPK and MELK in kidney cancer cells and found their growth promotive effect as well as some feedback mechanism between these two molecules. Interestingly, the blockade of either of these two kinases effectively caused downregulation of forkhead box protein M1 (FOXM1) activity which is known as an oncogenic transcriptional factor in various types of cancer cells. Small molecular compound inhibitors against TOPK (OTS514) and MELK (OTS167) effectively suppressed the kidney cancer cell growth, and the combination of these two compounds additively worked and showed the very strong growth suppressive effect on kidney cancer cells. Collectively, our results suggest that both TOPK and MELK are promising molecular targets for kidney cancer treatment and that dual blockade of OTS514 and OTS167 may bring additive anti-tumor effects with low risk of side effects. PMID:26933922

  2. Hesperetin, a Selective Phosphodiesterase 4 Inhibitor, Effectively Suppresses Ovalbumin-Induced Airway Hyperresponsiveness without Influencing Xylazine/Ketamine-Induced Anesthesia

    PubMed Central

    Shih, Chung-Hung; Lin, Ling-Hung; Hsu, Hsin-Te; Wang, Kuo-Hsien; Lai, Chi-Yin; Chen, Chien-Ming; Ko, Wun-Chang

    2012-01-01

    Hesperetin, a selective phosphodiesterase (PDE)4 inhibitor, is present in the traditional Chinese medicine, “Chen Pi.” Therefore, we were interested in investigating its effects on ovalbumin- (OVA-) induced airway hyperresponsiveness, and clarifying its rationale for ameliorating asthma and chronic obstructive pulmonary disease (COPD). Hesperetin was revealed to have a therapeutic (PDE4H/PDE4L) ratio of >11. Hesperetin (10 ~ 30 μmol/kg, intraperitoneally (i.p.)) dose-dependently and significantly attenuated the airway hyperresponsiveness induced by methacholine. It also significantly suppressed the increases in total inflammatory cells, macrophages, lymphocytes, neutrophils, and eosinophils, and levels of cytokines, including interleukin (IL)-2, IL-4, IL-5, interferon-γ, and tumor necrosis factor-α in bronchoalveolar lavage fluid (BALF). It dose-dependently and significantly suppressed total and OVA-specific immunoglobulin E levels in the BALF and serum. However, hesperetin did not influence xylazine/ketamine-induced anesthesia, suggesting that hesperetin has few or no emetic effects. In conclusion, the rationales for ameliorating allergic asthma and COPD by hesperetin are anti-inflammation, immunoregulation, and bronchodilation. PMID:22454667

  3. Normalizing the bone marrow microenvironment with p38 inhibitor reduces multiple myeloma cell proliferation and adhesion and suppresses osteoclast formation

    SciTech Connect

    Nguyen, Aaron N.; Stebbins, Elizabeth G.; Henson, Margaret; O'Young, Gilbert; Choi, Sun J.; Quon, Diana; Damm, Debby; Reddy, Mamatha; Ma, Jing Y.; Haghnazari, Edwin; Kapoun, Ann M.; Medicherla, Satyanarayana; Protter, Andy; Schreiner, George F.; Kurihara, Noriyoshi; Anderson, Judy; Roodman, G. David; Navas, Tony A.; Higgins, Linda S. . E-mail: lhiggin3@scius.jnj.com

    2006-06-10

    The multiple myeloma (MM) bone marrow (BM) microenvironment plays a critical role in supporting tumor growth and survival as well as in promoting formation of osteolytic lesions. Recent results suggest that the p38 mitogen-activated protein kinase (MAPK) is an important factor in maintaining this activated environment. In this report, we demonstrate that the p38{alpha} MAPK inhibitor, SCIO-469, suppresses secretion of the tumor-supportive factors IL-6 and VEGF from BM stromal cells (BMSCs) as well as cocultures of BMSCs with MM cells, resulting in reduction in MM cell proliferation. Additionally, we show that SCIO-469 prevents TNF{alpha}-induced adhesion of MM cells to BMSCs through an ICAM-1- and VCAM-1-independent mechanism. Microarray analysis revealed a novel set of TNF{alpha}-induced chemokines in BMSCs that is strongly inhibited by SCIO-469. Furthermore, reintroduction of chemokines CXCL10 and CCL8 to BMSCs overcomes the inhibitory effect of SCIO-469 on TNF{alpha}-induced MM adhesion. Lastly, we show that SCIO-469 inhibits secretion and expression of the osteoclast-activating factors IL-11, RANKL, and MIP-1{alpha} as well as prevents human osteoclast formation in vitro. Collectively, these results suggest that SCIO-469 treatment can suppress factors in the bone marrow microenvironment to inhibit MM cell proliferation and adhesion and also to alleviate osteolytic activation in MM.

  4. Calcineurin inhibitor tacrolimus does not interfere with the suppression of hepatitis C virus infection by interferon-alpha.

    PubMed

    Pan, Qiuwei; Metselaar, Herold J; de Ruiter, Petra; Kwekkeboom, Jaap; Tilanus, Hugo W; Janssen, Harry L A; van der Laan, Luc J W

    2010-04-01

    Immunosuppression considerably affects hepatitis C virus (HCV) recurrence and the outcome of antiviral treatment after liver transplantation. Recent findings have suggested that the calcineurin inhibitor tacrolimus (Tac), unlike cyclosporine A (CsA), interferes with the antiviral activity of interferon-alpha (IFN-alpha) in vitro. The aim of this study was to more extensively investigate the effects of calcineurin inhibitors on IFN-alpha signaling and antiviral activity in subgenomic and infectious HCV models. Treatment with Tac and CsA did not affect Huh7 cell proliferation at doses of 10 to 500 ng/mL; however, it completely inhibited T cell proliferation. In contrast to previous reports, Tac had no effect on IFN-alpha-stimulated reporter gene expression, even at the dose of 5 microg/mL. Furthermore, in Huh7 subgenomic HCV replicon cells, treatment with Tac had no significant effect on the suppression of viral replication by IFN-alpha. In the infectious HCV model, treatment with IFN-alpha effectively inhibited both viral RNA replication and de novo production of virus particles, and neither was attenuated at any concentration of Tac. CsA had no significant effect on IFN-alpha-stimulated reporter gene expression; however, as shown previously, a combination of CsA (at 500 ng/mL and higher) and IFN-alpha resulted in enhanced inhibition of viral replication in both the subgenomic and infectious HCV models. In conclusion, our study shows no evidence that Tac or CsA interferes with IFN-alpha-mediated inhibition of HCV replication and virion production in vitro. Therefore, no further mechanistic arguments have been found to break the clinical controversy about the choice of calcineurin inhibitors during posttransplantation antiviral therapy. PMID:20373462

  5. Lymphocyte-suppressing action of angiotensin-converting enzyme inhibitors in coronary artery disease patients with normal blood pressure.

    PubMed

    Krysiak, Robert; Okopień, Bogusław

    2011-01-01

    The clinical effectiveness of angiotensin-converting enzyme (ACE) in the prevention and treatment of cardiovascular disorders partially results from its anti-inflammatory action. No previous study has investigated the effect of any ACE inhibitor on lymphocyte cytokine release. In this study, we compared the effects of serum- and tissue-type angiotensin-converting enzyme inhibitors on systemic inflammation and lymphocyte secretory function in normotensive patients with stable coronary artery disease. The study included 134 patients with coronary artery disease who were randomized into one of three groups and treated with enalapril (20 mg/d, n = 47), perindopril (4 mg/d, n = 45) or placebo (n = 42), respectively. The control group included 40 age-, sex- and weight-matched healthy subjects. The plasma lipid profile, glucose metabolism markers, hsCRP and lymphocyte cytokine release were examined at the beginning of the study and after 30 and 90 days of treatment. Phytohemagglutinin-stimulated T cells released significantly more interleukin-2, interferon-γ and TNFα than the lymphocytes of control subjects. Neither enalapril nor perindopril treatment was associated with any significant changes in blood pressure. Perindopril treatment inhibited lymphocyte cytokine release and systemic inflammation, while the effect of enalapril was insignificant. Perindopril, and, to a lesser extent, enalapril, strongly reduced lymphocyte cytokine release in insulin-resistant but not insulin-sensitive subjects. Our results indicate that perindopril is superior to enalapril in producing lymphocyte-suppressing and systemic anti-inflammatory effects in normotensive coronary artery disease patients. These effects may contribute to a reduction in the vascular risk of this group of patients, particularly in those subjects who are resistant to insulin, when these patients are treated with tissue-type angiotensin-converting enzyme inhibitors. PMID:22180357

  6. A dual PI3K/AKT/mTOR signaling inhibitor miR-99a suppresses endometrial carcinoma

    PubMed Central

    Li, Yunyun; Zhang, Zhongzu; Zhang, Xiaojing; Lin, Ying; Luo, Tangshu; Xiao, Zhenghua; Zhou, Qin

    2016-01-01

    Activation of the PI3K/AKT/mTOR signaling pathway, a common mechanism in all subtypes of endometrial cancers (EC), plays an important role in the initiation and progression of many cancers. Inhibitors against various components of this pathway might promise a novel effective approach for targeted therapy for EC in the future. Intriguingly, two major members of this pathway, AKT1 and mTOR, were both reported to be the putative target genes of miR-99a, which were widely reported to function as a tumor suppressor in a variety of cancers. However, the direct role of miR-99a in endometrial cancer progression and the signaling pathways might been involved have never been deciphered. In this paper, we demonstrate that the expression of miR-99a was significantly suppressed in the EC tissues and was negatively correlated with the differentiation of tumors. Furthermore, we find that overexpression of miR-99a in EC cells induced a complex phenotype, namely an inhibition of cell proliferation, block of G1/S phase transition, induction of cell apoptosis, suppression of cell invasion, and inhibition of tumor growth in vivo, which was mediated, at least partially, through dual-suppression of PI3K/AKT/mTOR pathway. This finding not only helps us understand the molecular mechanism of endometrial carcinogenesis, but also gives us a strong rationale to further investigate miR-99a as a potential biomarker and therapeutic target for EC. PMID:27158364

  7. Proton pump inhibitors suppress iNOS-dependent DNA damage in Barrett's esophagus by increasing Mn-SOD expression

    SciTech Connect

    Thanan, Raynoo; Ma, Ning; Iijima, Katsunori; Abe, Yasuhiko; Koike, Tomoyuki; Shimosegawa, Tooru; Pinlaor, Somchai; Hiraku, Yusuke; Oikawa, Shinji; Murata, Mariko; Kawanishi, Shosuke

    2012-05-04

    Highlights: Black-Right-Pointing-Pointer Inflammation by Barrett's esophagus (BE) is a risk factor of its adenocarcinoma (BEA). Black-Right-Pointing-Pointer 8-Nitroguanine and 8-oxodG are inflammation-related DNA lesions. Black-Right-Pointing-Pointer DNA lesions and iNOS expression were higher in the order, BEA > BE > normal tissues. Black-Right-Pointing-Pointer Proton pump inhibitors suppress DNA damage by increasing Mn-SOD via Nrf2 activation. Black-Right-Pointing-Pointer DNA lesions can be useful biomarkers to predict risk of BEA in BE patients. -- Abstract: Barrett's esophagus (BE), an inflammatory disease, is a risk factor for Barrett's esophageal adenocarcinoma (BEA). Treatment of BE patients with proton pump inhibitors (PPIs) is expected to reduce the risk of BEA. We performed an immunohistochemical study to examine the formation of nitrative and oxidative DNA lesions, 8-nitroguanine and 8-oxo-7,8-dihydro-2 Prime -deoxygaunosine (8-oxodG), in normal esophageal, BE with pre- and post-treatment by PPIs and BEA tissues. We also observed the expression of an oxidant-generating enzyme (iNOS) and its transcription factor NF-{kappa}B, an antioxidant enzyme (Mn-SOD), its transcription factor (Nrf2) and an Nrf2 inhibitor (Keap1). The immunoreactivity of DNA lesions was significantly higher in the order of BEA > BE > normal tissues. iNOS expression was significantly higher in the order of BEA > BE > normal tissues, while Mn-SOD expression was significantly lower in the order of BEA < BE < normal tissues. Interestingly, Mn-SOD expression and the nuclear localization of Nrf2 were significantly increased, and the formation of DNA lesions was significantly decreased in BE tissues after PPIs treatment for 3-6 months. Keap1 and iNOS expression was not significantly changed by the PPIs treatment in BE tissues. These results indicate that 8-nitroguanine and 8-oxodG play a role in BE-derived BEA. Additionally, PPIs treatment may trigger the activation and nuclear translocation

  8. Inhibitors

    MedlinePlus

    ... Community Counts Blood Safety Inhibitors Articles & Key Findings Free Materials Videos Starting the Conversation Playing it Safe A Look at Hemophilia Joint Range of Motion My Story Links to Other Websites ...

  9. Novel STAT3 phosphorylation inhibitors exhibit potent growth suppressive activity in pancreatic and breast cancer cells

    PubMed Central

    Lin, Li; Hutzen, Brian; Zuo, Mingxin; Ball, Sarah; Deangelis, Stephanie; Foust, Elizabeth; Pandit, Bulbul; Ihnat, Michael A.; Shenoy, Satyendra S.; Kulp, Samuel; Li, Pui-Kai; Li, Chenglong; Fuchs, James; Lin, Jiayuh

    2010-01-01

    The constitutive activation of Signal Transducer and Activator of Transcription 3 (STAT3) is frequently detected in most types of human cancer where it plays important roles in survival, drug-resistance, angiogenesis, and other functions. Targeting constitutive STAT3 signaling is thus an attractive therapeutic approach for these cancers. We have recently developed novel small molecule STAT3 inhibitors known as FLLL31 and FLLL32, which are derived from curcumin (the primary bioactive compound of turmeric). These compounds are designed to bind selectively to Janus Kinase 2 (JAK2) and the STAT3 SH2 domain, which serves crucial roles in STAT3 dimerization and signal transduction. Here we show that FLLL31 and FLLL32 are effective inhibitors of STAT3 phosphorylation, DNA binding activity, and transactivation in vitro, leading to the impediment of multiple oncogenic processes and the induction of apoptosis in pancreatic and breast cancer cell lines. FLLL31 and FLLL32 also inhibit colony formation in soft agar, cell invasion, and exhibit synergy with the anti-cancer drug doxorubicin against breast cancer cells. In addition, we show that FLLL32 can inhibit the induction of STAT3 phosphorylation by Interferon-α (IFNα) and Interleukin-6 (IL-6) in breast cancer cells. We also demonstrate that administration of FLLL32 can inhibit tumor growth and vascularity in chicken embryo xenografts as well as substantially reduce tumor volumes in mouse xenografts. Our findings highlight the potential of these new compounds and their efficacy in targeting pancreatic and breast cancers that exhibit constitutive STAT3 signaling. PMID:20215512

  10. AT9283, a novel aurora kinase inhibitor, suppresses tumor growth in aggressive B-cell lymphomas.

    PubMed

    Qi, Wenqing; Liu, Xiaobing; Cooke, Laurence S; Persky, Daniel O; Miller, Thomas P; Squires, Matthew; Mahadevan, Daruka

    2012-06-15

    Aurora kinases are oncogenic serine/threonine kinases that play key roles in regulating the mitotic phase of the eukaryotic cell cycle. Auroras are overexpressed in numerous tumors including B-cell non-Hodgkin's lymphomas and are validated oncology targets. AT9283, a pan-aurora inhibitor inhibited growth and survival of multiple solid tumors in vitro and in vivo. In this study, we demonstrated that AT9283 had potent activity against Aurora B in a variety of aggressive B-(non-Hodgkin lymphoma) B-NHL cell lines. Cells treated with AT9283 exhibited endoreduplication confirming the mechanism of action of an Aurora B inhibitor. Also, treatment of B-NHL cell lines with AT9283 induced apoptosis in a dose and time dependent manner and inhibited cell proliferation with an IC(50) < 1 μM. It is well known that inhibition of auroras (A or B) synergistically enhances the effects of microtubule targeting agents such as taxanes and vinca alkaloids to induce antiproliferation and apoptosis. We evaluated whether AT9283 in combination with docetaxel is more efficient in inducing apoptosis than AT9283 or docetaxel alone. At very low doses (5 nM) apoptosis was doubled in the combination (23%) compared to AT9283 or docetaxel alone (10%). A mouse xenograft model of mantle cell lymphoma demonstrated that AT9283 at 15 mg/kg and docetaxel (10 mg/kg) alone had modest anti-tumor activity. However, AT9283 at 20 mg/kg and AT9283 (15 or 20 mg/kg) plus docetaxel (10 mg/kg) demonstrated a statistically significant tumor growth inhibition and enhanced survival. Together, our results suggest that AT9283 plus docetaxel may represent a novel therapeutic strategy in B-cell NHL and warrant early phase clinical trial evaluation. PMID:21796626

  11. Plants Release Precursors of Histone Deacetylase Inhibitors to Suppress Growth of Competitors.

    PubMed

    Venturelli, Sascha; Belz, Regina G; Kämper, Andreas; Berger, Alexander; von Horn, Kyra; Wegner, André; Böcker, Alexander; Zabulon, Gérald; Langenecker, Tobias; Kohlbacher, Oliver; Barneche, Fredy; Weigel, Detlef; Lauer, Ulrich M; Bitzer, Michael; Becker, Claude

    2015-11-01

    To secure their access to water, light, and nutrients, many plant species have developed allelopathic strategies to suppress competitors. To this end, they release into the rhizosphere phytotoxic substances that inhibit the germination and growth of neighbors. Despite the importance of allelopathy in shaping natural plant communities and for agricultural production, the underlying molecular mechanisms are largely unknown. Here, we report that allelochemicals derived from the common class of cyclic hydroxamic acid root exudates directly affect the chromatin-modifying machinery in Arabidopsis thaliana. These allelochemicals inhibit histone deacetylases both in vitro and in vivo and exert their activity through locus-specific alterations of histone acetylation and associated gene expression. Our multilevel analysis collectively shows how plant-plant interactions interfere with a fundamental cellular process, histone acetylation, by targeting an evolutionarily highly conserved class of enzymes. PMID:26530086

  12. Plants Release Precursors of Histone Deacetylase Inhibitors to Suppress Growth of Competitors[OPEN

    PubMed Central

    Venturelli, Sascha; Belz, Regina G.; Kämper, Andreas; Berger, Alexander; von Horn, Kyra; Wegner, André; Böcker, Alexander; Zabulon, Gérald; Barneche, Fredy; Lauer, Ulrich M.; Bitzer, Michael

    2015-01-01

    To secure their access to water, light, and nutrients, many plant species have developed allelopathic strategies to suppress competitors. To this end, they release into the rhizosphere phytotoxic substances that inhibit the germination and growth of neighbors. Despite the importance of allelopathy in shaping natural plant communities and for agricultural production, the underlying molecular mechanisms are largely unknown. Here, we report that allelochemicals derived from the common class of cyclic hydroxamic acid root exudates directly affect the chromatin-modifying machinery in Arabidopsis thaliana. These allelochemicals inhibit histone deacetylases both in vitro and in vivo and exert their activity through locus-specific alterations of histone acetylation and associated gene expression. Our multilevel analysis collectively shows how plant-plant interactions interfere with a fundamental cellular process, histone acetylation, by targeting an evolutionarily highly conserved class of enzymes. PMID:26530086

  13. The Rac1 Inhibitor NSC23766 Suppresses CREB Signaling by Targeting NMDA Receptor Function

    PubMed Central

    Hou, Hailong; Chávez, Andrés E.; Wang, Chih-Chieh; Yang, Hongtian; Gu, Hua; Siddoway, Benjamin A.; Hall, Benjamin J.; Castillo, Pablo E.

    2014-01-01

    NMDA receptor signaling plays a complex role in CREB activation and CREB-mediated gene transcription, depending on the subcellular location of NMDA receptors, as well as how strongly they are activated. However, it is not known whether Rac1, the prototype of Rac GTPase, plays a role in neuronal CREB activation induced by NMDA receptor signaling. Here, we report that NSC23766, a widely used specific Rac1 inhibitor, inhibits basal CREB phosphorylation at S133 (pCREB) and antagonizes changes in pCREB levels induced by NMDA bath application in rat cortical neurons. Unexpectedly, we found that NSC23766 affects the levels of neuronal pCREB in a Rac1-independent manner. Instead, our results indicate that NSC23766 can directly regulate NMDA receptors as indicated by their strong effects on both exogenous and synaptically evoked NMDA receptor-mediated currents in mouse and rat neurons, respectively. Our findings strongly suggest that Rac1 does not affect pCREB signaling in cortical neurons and reveal that NSC23766 could be a novel NMDA receptor antagonist. PMID:25319697

  14. Suppression of cell cycle progression by a fungal lectin: activation of cyclin-dependent kinase inhibitors.

    PubMed

    Liua, W; Ho, J C; Ng, T

    2001-01-01

    The antiproliferative activity of a fungal lectin (VVL) isolated from the mushroom, Volvariella volvacea, was studied using a battery of cultured tumor cell lines. It was revealed that [(3)H]thymidine incorporation into the cell lines was markedly reduced at 0.32 microM VVL. When S180 mouse sarcoma cells were incubated for 48 hr with doses of VVL ranging from 0.32 to 0.8 microM, prominent blebs on the cell surface and large vacuoles in the cytoplasm, but not apoptotic bodies, were observed under a fluorescence microscopy. VVL did not exert ribosome-inactivating activity or induce any changes in the expression of cyclins A, D1, and E. However, it did activate the expression of cyclin kinase inhibitors, namely p21, p27, p53, and Rb, in a dose-dependent manner. Flow cytometric analysis demonstrated an accumulation of cells in the G2/M phase in a time- and dose-dependent manner, indicating that VVL arrested cell proliferation by blocking cell cycle progression in the G2/M phase. PMID:11137706

  15. The PI3Kδ inhibitor idelalisib suppresses liver and lung cellular respiration

    PubMed Central

    Hammadi, Suleiman Al; Almarzooqi, Saeeda; Abdul-Kader, Hidaya Mohammed; Saraswathiamma, Dhanya; Souid, Abdul-Kader

    2015-01-01

    Idelalisib (an inhibitor of phosphatidylinositol-3-kinase-delta) is approved for treatment of B-cell malignancies, with a Boxed Warning concerning potentially fatal hepatic, lung, and intestinal toxicities. The mechanisms of these tissue-specific adverse events have yet to be elucidated. This in vitro study investigated whether these effects could be attributed, at least in part, to altered cellular bioenergetics. A phosphorescence analyzer was used to measure cellular mitochondrial O2 consumption (kc, µM O2 min-1 mg-1) in C57BL/6 mouse organs in the presence of 10 µM idelalisib or dimethyl-sulfoxide. Idelalisib significantly reduced the rate of cellular respiration in liver and lung fragments by 20% and 27%, respectively. Respiration in intestinal, thymic, and kidney fragments was unaffected. Idelalisib did not alter respiratory chain activities in mitochondria isolated from the liver and did not induce hepatocyte death. Thus, the drug mildly lowers liver and lung cellular respiration, an effect that may contribute to toxicities observed in these organs. PMID:26823960

  16. Suppressive effect of topoisomerase inhibitors on JC polyomavirus propagation in human neuroblastoma cells.

    PubMed

    Nukuzuma, Souichi; Nakamichi, Kazuo; Kameoka, Masanori; Sugiura, Shigeki; Nukuzuma, Chiyoko; Tasaki, Takafumi; Takegami, Tsutomu

    2016-04-01

    JC polyomavirus (JCPyV) causes progressive multifocal leukoencephalopathy (PML), a fatal demyelinating disease of the central nervous system, in immunocompromised patients. Because no drugs have been approved for treating PML, many antiviral agents are currently being investigated for this purpose. The inhibitory effects of the topoisomerase I inhibitors topotecan and β-lapachone were assessed by investigating viral replication, propagation and viral protein 1 (VP1) production in cultured cells. JCPyV replication was assayed using the human neuroblastoma cell line IMR-32 transfected with the JCPyV plasmid and RT- PCR combined with Dpn I treatment. Dpn I digests the input plasmid DNA containing methylated adenosine, but not newly replicated JCPyV DNA, in IMR-32 cells. It was found that JCPyV replicates less in IMR-32 cells treated with topotecan or β-lapachone than in untreated cells. Moreover, drug treatment of JCI cells, which are IMR-32 cells persistently infected with JCPyV, led to a reduction in the amount of JCPyV DNA and population of VP1-positive cells. These results demonstrate that topotecan and β-lapachone affects JCPyV propagation in human neuroblastoma cell lines, suggesting that topotecan and β-lapachone could potentially be used to treat PML. PMID:26935240

  17. Piperlongumine as a direct TrxR1 inhibitor with suppressive activity against gastric cancer.

    PubMed

    Zou, Peng; Xia, Yiqun; Ji, Jiansong; Chen, Weiqian; Zhang, Jinsan; Chen, Xi; Rajamanickam, Vinothkumar; Chen, Gaozhi; Wang, Zhe; Chen, Lingfeng; Wang, Yifeng; Yang, Shulin; Liang, Guang

    2016-05-28

    Piperlongumine (PL), a natural alkaloid isolated from the fruit of long pepper, is known to selectively kill tumor cells while sparing their normal counterparts. However, the cellular target and potent anticancer efficacy of PL in numerous types of human cancer cells have not been fully defined. We report here that PL may interact with the thioredoxin reductase 1 (TrxR1), an important selenocysteine (Sec)-containing antioxidant enzyme, to induce reactive oxygen species (ROS)-mediated apoptosis in human gastric cancer cells. By inhibiting TrxR1 activity and increasing intracellular ROS levels, PL induces a lethal endoplasmic reticulum stress and mitochondrial dysfunction in human gastric cancer cells. Importantly, knockdown of TrxR1 sensitizes cells to PL treatment, and PL displays synergistic lethality with GSH inhibitors (BSO and Erastin) against gastric cancer cells. In vivo, PL treatment markedly reduces the TrxR1 activity and tumor cell burden. Remarkably, TrxR1 was significantly overexpressed in gastric cancer cell lines and human gastric cancer tissues. Targeting TrxR1 with PL thus discloses a previously unrecognized mechanism underlying the biological activity of PL and provides an in-depth insight into the action of PL in the treatment of gastric cancer. PMID:26963494

  18. Inhibitors of protein disulfide isomerase suppress apoptosis induced by misfolded proteins

    PubMed Central

    Hoffstrom, Benjamin G.; Kaplan, Anna; Letso, Reka; Schmid, Ralf; Turmel, Gregory J.; Lo, Donald C.; Stockwell, Brent R.

    2010-01-01

    A hallmark of many neurodegenerative diseases is accumulation of misfolded proteins within neurons, leading to cellular dysfunction and cell death. Although several mechanisms have been proposed to link protein misfolding to cellular toxicity, the connection remains enigmatic. Here, we report a cell death pathway involving protein disulfide isomerase (PDI), a protein chaperone that catalyzes isomerization, reduction, and oxidation of disulfides. Through a small-molecule-screening approach, we discovered five structurally distinct compounds that prevent apoptosis induced by mutant huntingtin protein. Using modified Huisgen cycloaddition chemistry, we then identified PDI as the molecular target of these small molecules. Expression of polyglutamine-expanded huntingtin exon 1 in PC12 cells caused PDI to accumulate at mitochondrial-associated-ER-membranes and trigger apoptotic cell death, via mitochondrial outer membrane permeabilization. Inhibiting PDI in rat brain cells suppressed the toxicity of mutant huntingtin exon1 and Aβ peptides processed from the amyloid precursor protein. This pro-apoptotic function of PDI provides a new mechanism linking protein misfolding and apoptotic cell death. PMID:21079601

  19. Histone deacetylase inhibitors suppress RSV infection and alleviate virus-induced airway inflammation.

    PubMed

    Feng, Qiuqin; Su, Zhonglan; Song, Shiyu; Χu, Hui; Zhang, Bin; Yi, Long; Tian, Man; Wang, Hongwei

    2016-09-01

    Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in infants and young children. However, the majority of RSV-infected patients only show mild symptoms. Different severities of infection and responses among the RSV-infected population indicate that epigenetic regulation as well as personal genetic background may affect RSV infectivity. Histone deacetylase (HDAC) is an important epigenetic regulator in lung diseases. The present study aimed to explore the possible connection between HDAC expression and RSV-induced lung inflammation. To address this question, RSV-infected airway epithelial cells (BEAS‑2B) were prepared and a mouse model of RSV infection was established, and then treated with various concentrations of HDAC inhibitors (HDACis), namely trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA). Viral replication and markers of virus-induced airway inflammation or oxidative stress were assessed. The activation of the nuclear factor-κB (NF-κB), cyclo-oxygenase-2 (COX-2), mitogen-activated protein kinase (MAPK) and signal transducer and activator of transcription 3 (STAT3) signaling pathways was evaluated by western blot analysis. Our results showed that RSV infection in airway epithelial cells (AECs) significantly decreased histone acetylation levels by altering HDAC2 expression. The treatment of RSV-infected AECs with HDACis significantly restricted RSV replication by upregulating the interferon-α (IFN-α) related signaling pathways. The treatment of RSV-infected AECs with HDACis also significantly inhibited RSV-induced pro-inflammatory cytokine release [interleukin (IL)-6 and IL-8] and oxidative stress-related molecule production [malondialdehyde (MDA), and nitrogen monoxide (NO)]. The activation of NF-κB, COX-2, MAPK and Stat3, which orchestrate pro‑inflammatory gene expression and oxidative stress injury, was also significantly inhibited. Our in vivo study using a mouse model of

  20. Histone deacetylase inhibitors suppress RSV infection and alleviate virus-induced airway inflammation

    PubMed Central

    Feng, Qiuqin; Su, Zhonglan; Song, Shiyu; Xu, Hui; Zhang, Bin; Yi, Long; Tian, Man; Wang, Hongwei

    2016-01-01

    Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in infants and young children. However, the majority of RSV-infected patients only show mild symptoms. Different severities of infection and responses among the RSV-infected population indicate that epigenetic regulation as well as personal genetic background may affect RSV infectivity. Histone deacetylase (HDAC) is an important epigenetic regulator in lung diseases. The present study aimed to explore the possible connection between HDAC expression and RSV-induced lung inflammation. To address this question, RSV-infected airway epithelial cells (BEAS-2B) were prepared and a mouse model of RSV infection was established, and then treated with various concentrations of HDAC inhibitors (HDACis), namely trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA). Viral replication and markers of virus-induced airway inflammation or oxidative stress were assessed. The activation of the nuclear factor-κB (NF-κB), cyclo-oxygenase-2 (COX-2), mitogen-activated protein kinase (MAPK) and signal transducer and activator of transcription 3 (STAT3) signaling pathways was evaluated by western blot analysis. Our results showed that RSV infection in airway epithelial cells (AECs) significantly decreased histone acetylation levels by altering HDAC2 expression. The treatment of RSV-infected AECs with HDACis significantly restricted RSV replication by upregulating the interferon-α (IFN-α) related signaling pathways. The treatment of RSV-infected AECs with HDACis also significantly inhibited RSV-induced pro-inflammatory cytokine release [interleukin (IL)-6 and IL-8] and oxidative stress-related molecule production [malondialdehyde (MDA), and nitrogen monoxide (NO)]. The activation of NF-κB, COX-2, MAPK and Stat3, which orchestrate pro-inflammatory gene expression and oxidative stress injury, was also significantly inhibited. Our in vivo study using a mouse model of RSV infection

  1. Suppressive Effects of the Site 1 Protease (S1P) Inhibitor, PF-429242, on Dengue Virus Propagation

    PubMed Central

    Uchida, Leo; Urata, Shuzo; Ulanday, Gianne Eduard L.; Takamatsu, Yuki; Yasuda, Jiro; Morita, Kouichi; Hayasaka, Daisuke

    2016-01-01

    Dengue virus (DENV) infection causes one of the most widespread mosquito-borne diseases in the world. Despite the great need, effective vaccines and practical antiviral therapies are still under development. Intracellular lipid levels are regulated by sterol regulatory elements-binding proteins (SREBPs), which are activated by serine protease, site 1 protease (S1P). Small compound PF-429242 is known as a S1P inhibitor and the antivirus effects have been reported in some viruses. In this study, we examined the anti-DENV effects of PF-429242 using all four serotypes of DENV by several primate-derived cell lines. Moreover, emergence of drug-resistant DENV mutants was assessed by sequential passages with the drug. DENV dependency on intracellular lipids during their infection was also evaluated by adding extracellular lipids. The addition of PF-429242 showed suppression of viral propagation in all DENV serotypes. We showed that drug-resistant DENV mutants are unlikely to emerge after five times sequential passages through treatment with PF-429242. Although the levels of intracellular cholesterol and lipid droplets were reduced by PF-429242, viral propagations were not recovered by addition of exogenous cholesterol or fatty acids, indicating that the reduction of LD and cholesterol caused by PF-429242 treatment is not related to its mechanism of action against DENV propagation. Our results suggest that PF-429242 is a promising candidate for an anti-DENV agent. PMID:26875984

  2. Suppressive Effects of the Site 1 Protease (S1P) Inhibitor, PF-429242, on Dengue Virus Propagation.

    PubMed

    Uchida, Leo; Urata, Shuzo; Ulanday, Gianne Eduard L; Takamatsu, Yuki; Yasuda, Jiro; Morita, Kouichi; Hayasaka, Daisuke

    2016-02-01

    Dengue virus (DENV) infection causes one of the most widespread mosquito-borne diseases in the world. Despite the great need, effective vaccines and practical antiviral therapies are still under development. Intracellular lipid levels are regulated by sterol regulatory elements-binding proteins (SREBPs), which are activated by serine protease, site 1 protease (S1P). Small compound PF-429242 is known as a S1P inhibitor and the antivirus effects have been reported in some viruses. In this study, we examined the anti-DENV effects of PF-429242 using all four serotypes of DENV by several primate-derived cell lines. Moreover, emergence of drug-resistant DENV mutants was assessed by sequential passages with the drug. DENV dependency on intracellular lipids during their infection was also evaluated by adding extracellular lipids. The addition of PF-429242 showed suppression of viral propagation in all DENV serotypes. We showed that drug-resistant DENV mutants are unlikely to emerge after five times sequential passages through treatment with PF-429242. Although the levels of intracellular cholesterol and lipid droplets were reduced by PF-429242, viral propagations were not recovered by addition of exogenous cholesterol or fatty acids, indicating that the reduction of LD and cholesterol caused by PF-429242 treatment is not related to its mechanism of action against DENV propagation. Our results suggest that PF-429242 is a promising candidate for an anti-DENV agent. PMID:26875984

  3. Coumarin sulfonamides derivatives as potent and selective COX-2 inhibitors with efficacy in suppressing cancer proliferation and metastasis.

    PubMed

    Lu, Xiao-Yuan; Wang, Zhong-Chang; Ren, Shen-Zhen; Shen, Fa-Qian; Man, Ruo-Jun; Zhu, Hai-Liang

    2016-08-01

    Cyclooxygenase-2 is frequently overexpression in malignant tumors and the product PGE2 promotes cancer cell progression and metastasis. We designed novel series of coumarin sulfonamides derivatives to improve biological activities of COX-2 inhibition and anticancer. Among them, compound 7t showed most powerful selective inhibitory and antiproliferative activity (IC50=0.09μM for COX-2, IC50=48.20μM for COX-1, IC50=0.36μM against HeLa cells), comparable to the control positive compound Celecoxib (0.31μM, 43.37μM, 7.79μM). Cancer cell apoptosis assay were performed and results indicated that compound 7t effectively fuels HeLa cells apoptosis in a dose and time-dependent manner. Moreover, 7t could significantly suppress cancer cell adhesion, migration and invasion which were essential process of cancer metastasis. Docking simulations results was further indicated that compound 7t could bind well to the COX-2 active site and guided a reasonable design of selective COX-2 inhibitor with anticancer activities in future. PMID:27349331

  4. Selective PCAF inhibitor ameliorates cognitive and behavioral deficits by suppressing NF-κB-mediated neuroinflammation induced by Aβ in a model of Alzheimer's disease.

    PubMed

    Park, Soo-Yeon; Kim, Mi-Jeong; Kim, Young Jun; Lee, Yoo-Hyun; Bae, Donghyuk; Kim, Sunoh; Na, Younghwa; Yoon, Ho-Geun

    2015-04-01

    Several recent studies have reported an association between neurodegeneration and histone modifications, such as acetylation, deacetylation and methylation. In addition, questions have been raised regarding a potential functional role for the histone acetylation enzymes in β-amyloid (Aβ)-mediated neurotoxicity, particularly the p300/CBP-associated factor (PCAF) enzyme. We recently reported the potential utility of a PCAF inhibitor in the suppression of Aβ-induced neuronal cell death, although the in vivo effectiveness of the PCAF inhibitor remained unclear. In this study, we modified the PCAF inhibitor by chemical derivatization and selected compound C-30-27 as the most potent PCAF inhibitor. We demonstrated that C-30-27 selectively inhibited acetylation-dependent nuclear factor-κB (NF-κB) at Lys-122 and suppressed the NF-κB-mediated inflammatory response induced by lipopolysaccharide (LPS) or Aβ in both BV2 and Neuro-2A (N2A) cells. Finally, we demonstrated that C-30-27 improved cognitive deficits, as well as the capacity for locomotion and the damaged cholinergic system in the Aβ-treated rats. In conclusion, our results demonstrate that this selective PCAF inhibitor has the potential to reduce the neuroinflammatory response induced by Aβ. PMID:25672970

  5. Bromoenol Lactone, an Inhibitor of Calcium-Independent Phospholipase A2, Suppresses Carrageenan-Induced Prostaglandin Production and Hyperalgesia in Rat Hind Paw

    PubMed Central

    Tsuchida, Keiichiro; Ibuki, Takae; Matsumura, Kiyoshi

    2015-01-01

    Prostaglandin (PG) E2 and PGI2 are essential to hyperalgesia in inflammatory tissues. These prostaglandins are produced from arachidonic acid, which is cleaved from membrane phospholipids by the action of phospholipase A2 (PLA2). Which isozyme of PLA2 is responsible for the cleavage of arachidonic acid and the production of prostaglandins essential to inflammation-induced hyperalgesia is not clear. In this study, we examined the effects of two PLA2 isozyme-specific inhibitors on carrageenan-induced production of PGE2 and PGI2 in rat hind paw and behavioral nociceptive response to radiant heat. Local administration of bromoenol lactone (BEL), an inhibitor of calcium-independent PLA2 (iPLA2), significantly reduced carrageenan-induced elevation of prostaglandins in the inflamed foot pad 3 h after injection. It also ameliorated the hyperalgesic response between 1 h and 3 h after carrageenan injection. On the other hand, AACOCF3, an inhibitor of cytosolic PLA2, suppressed neither prostaglandin production nor the hyperalgesic response. BEL did not suppress the mRNA levels of iPLA2β, iPLA2γ, cyclooxygenase-2, microsomal prostaglandin E synthase, prostaglandin I synthase, or proinflammatory cytokines in the inflamed foot pad, indicating that BEL did not suppress inflammation itself. These results suggest that iPLA2 is involved in the production of prostaglandins and hyperalgesia at the inflammatory loci. PMID:26063975

  6. Glycogen synthase kinase 3 inhibitors induce the canonical WNT/β-catenin pathway to suppress growth and self-renewal in embryonal rhabdomyosarcoma

    PubMed Central

    Chen, Eleanor Y.; DeRan, Michael T.; Ignatius, Myron S.; Grandinetti, Kathryn Brooke; Clagg, Ryan; McCarthy, Karin M.; Lobbardi, Riadh M.; Brockmann, Jillian; Keller, Charles; Wu, Xu; Langenau, David M.

    2014-01-01

    Embryonal rhabdomyosarcoma (ERMS) is a common pediatric malignancy of muscle, with relapse being the major clinical challenge. Self-renewing tumor-propagating cells (TPCs) drive cancer relapse and are confined to a molecularly definable subset of ERMS cells. To identify drugs that suppress ERMS self-renewal and induce differentiation of TPCs, a large-scale chemical screen was completed. Glycogen synthase kinase 3 (GSK3) inhibitors were identified as potent suppressors of ERMS growth through inhibiting proliferation and inducing terminal differentiation of TPCs into myosin-expressing cells. In support of GSK3 inhibitors functioning through activation of the canonical WNT/β-catenin pathway, recombinant WNT3A and stabilized β-catenin also enhanced terminal differentiation of human ERMS cells. Treatment of ERMS-bearing zebrafish with GSK3 inhibitors activated the WNT/β-catenin pathway, resulting in suppressed ERMS growth, depleted TPCs, and diminished self-renewal capacity in vivo. Activation of the canonical WNT/β-catenin pathway also significantly reduced self-renewal of human ERMS, indicating a conserved function for this pathway in modulating ERMS self-renewal. In total, we have identified an unconventional tumor suppressive role for the canonical WNT/β-catenin pathway in regulating self-renewal of ERMS and revealed therapeutic strategies to target differentiation of TPCs in ERMS. PMID:24706870

  7. LYTAK1, a TAK1 inhibitor, suppresses proliferation and epithelial‑mesenchymal transition in retinal pigment epithelium cells.

    PubMed

    Chen, Zhen; Mei, Yan; Lei, Huo; Tian, Run; Ni, Ninghua; Han, Fang; Gan, Shengwei; Sun, Shanquan

    2016-07-01

    The proliferation of retinal pigment epithelium (RPE) cells following epithelial‑mesenchymal transition (EMT) is critical in proliferative vitreoretinopathy (PVR), which results in retinal detachment and the loss of vision. The current study was conducted to examine the importance of transforming growth factor β‑1 (TGF‑β1)‑activated kinase 1 (TAK1) inhibitor (LYTAK1) in regulating EMT and the proliferation of RPE cells. RPE cells were pre-treated with increasing concentrations of LYTAK1 prior to treatment with TGF‑β1 for 24 h. The effect of LYTAK1 on RPE cell proliferation was examined using a Cell Counting kit‑8 assay. The expression levels of TAK1, smooth muscle actin, fibronectin, p-Smad2, p-Smad3, nuclear factor (NF)-κB p65 and IκB kinase α were detected by western blotting. LYTAK1 suppressed the proliferation and migration of RPE cells. Additionally, LYTAK1 significantly prevented TGF‑β1‑induced EMT by decreasing the levels of fibronectin and α‑smooth muscle actin. It was demonstrated that the effects of LYTAK1 were via the Smad signaling pathway. The present study also determined, that the underlying mechanism of the effects of LYTAK1 on EMT in RPE cells involves downregulation of the NF‑κB signaling pathway. In conclusion, TAK1 transcription factor was shown to be important in TGF‑β1‑induced EMT in human RPE cells. Thus, the results of this study aid in elucidating the pathogenesis of human PVR. In addition, this study suggests that specific inhibition by LYTAK1 may provide a novel approach for the treatment and prevention of PVR. PMID:27175834

  8. LYTAK1, a TAK1 inhibitor, suppresses proliferation and epithelial-mesenchymal transition in retinal pigment epithelium cells

    PubMed Central

    CHEN, ZHEN; MEI, YAN; LEI, HUO; TIAN, RUN; NI, NINGHUA; HAN, FANG; GAN, SHENGWEI; SUN, SHANQUAN

    2016-01-01

    The proliferation of retinal pigment epithelium (RPE) cells following epithelial-mesenchymal transition (EMT) is critical in proliferative vitreoretinopathy (PVR), which results in retinal detachment and the loss of vision. The current study was conducted to examine the importance of transforming growth factor β-1 (TGF-β1)-activated kinase 1 (TAK1) inhibitor (LYTAK1) in regulating EMT and the proliferation of RPE cells. RPE cells were pre-treated with increasing concentrations of LYTAK1 prior to treatment with TGF-β1 for 24 h. The effect of LYTAK1 on RPE cell proliferation was examined using a Cell Counting kit-8 assay. The expression levels of TAK1, smooth muscle actin, fibronectin, p-Smad2, p-Smad3, nuclear factor (NF)-κB p65 and IκB kinase α were detected by western blotting. LYTAK1 suppressed the proliferation and migration of RPE cells. Additionally, LYTAK1 significantly prevented TGF-β1-induced EMT by decreasing the levels of fibronectin and α-smooth muscle actin. It was demonstrated that the effects of LYTAK1 were via the Smad signaling pathway. The present study also determined, that the underlying mechanism of the effects of LYTAK1 on EMT in RPE cells involves downregulation of the NF-κB signaling pathway. In conclusion, TAK1 transcription factor was shown to be important in TGF-β1-induced EMT in human RPE cells. Thus, the results of this study aid in elucidating the pathogenesis of human PVR. In addition, this study suggests that specific inhibition by LYTAK1 may provide a novel approach for the treatment and prevention of PVR. PMID:27175834

  9. Bortezomib induces apoptosis and growth suppression in human medulloblastoma cells, associated with inhibition of AKT and NF-ĸB signaling, and synergizes with an ERK inhibitor

    PubMed Central

    Yang, Fan; Jove, Veronica; Chang, Shirley; Hedvat, Michael; Liu, Lucy; Buettner, Ralf; Tian, Yan; Scuto, Anna; Wen, Wei; Yip, M.L. Richard; Van Meter, Timothy; Yen, Yun; Jove, Richard

    2012-01-01

    Medulloblastoma is the most common brain tumor in children. Here, we report that bortezomib, a proteasome inhibitor, induced apoptosis and inhibited cell proliferation in two established cell lines and a primary culture of human medulloblastomas. Bortezomib increased the release of cytochrome c to cytosol and activated caspase-9 and caspase-3, resulting in cleavage of PARP. Caspase inhibitor (Z-VAD-FMK) could rescue medulloblastoma cells from the cytotoxicity of bortezomib. Phosphorylation of AKT and its upstream regulator mTOR were reduced by bortezomib treatment in medulloblastoma cells. Bortezomib increased the expression of Bad and Bak, pro-apoptotic proteins, and p21Cip1 and p27Kip1, negative regulators of cell cycle progression, which are associated with the growth suppression and induction of apoptosis in these tumor cells. Bortezomib also increased the accumulation of phosphorylated IĸBα, and decreased nuclear translocation of NF-ĸB. Thus, NF-ĸB signaling and activation of its downstream targets are suppressed. Moreover, ERK inhibitors or downregulating ERK with ERK siRNA synergized with bortezomib on anticancer effects in medulloblastoma cells. Bortezomib also inhibited the growth of human medulloblastoma cells in a mouse xenograft model. These findings suggest that proteasome inhibitors are potentially promising drugs for treatment of pediatric medulloblastomas. PMID:22313636

  10. Delphinidin, a specific inhibitor of histone acetyltransferase, suppresses inflammatory signaling via prevention of NF-{kappa}B acetylation in fibroblast-like synoviocyte MH7A cells

    SciTech Connect

    Seong, Ah-Reum; Yoo, Jung-Yoon; Choi, KyungChul; Lee, Mee-Hee; Lee, Yoo-Hyun; Lee, Jeongmin; Jun, Woojin; Kim, Sunoh; Yoon, Ho-Geun

    2011-07-08

    Highlights: {yields} Delphinidin is a novel inhibitor of p300/CBP histone acetyltransferase. {yields} Delphinidin prevents the hyperacetylation of p65 by inhibiting the HAT activity of p300/CBP. {yields} Delphinidin efficiently suppresses the expression of inflammatory cytokines in MH7A cells via hypoacetylation of NF-{kappa}B. {yields} Delphinidin inhibits cytokine release in the Jurkat T lymphocyte cell line. -- Abstract: Histone acetyltransferase (HAT) inhibitors (HATi) isolated from dietary compounds have been shown to suppress inflammatory signaling, which contributes to rheumatoid arthritis. Here, we identified a novel HATi in Punica granatum L. known as delphinidin (DP). DP did not affect the activity of other epigenetic enzymes (histone deacetylase, histone methyltransferase, or sirtuin1). DP specifically inhibited the HAT activities of p300/CBP. It also inhibited p65 acetylation in MH7A cells, a human rheumatoid arthritis synovial cell line. DP-induced hypoacetylation was accompanied by cytosolic accumulation of p65 and nuclear localization of IKB{alpha}. Accordingly, DP treatment inhibited TNF{alpha}-stimulated increases in NF-{kappa}B function and expression of NF-{kappa}B target genes in these cells. Importantly, DP suppressed lipopolysaccharide-induced pro-inflammatory cytokine expression in Jurkat T lymphocytes, demonstrating that HATi efficiently suppresses cytokine-mediated immune responses. Together, these results show that the HATi activity of DP counters anti-inflammatory signaling by blocking p65 acetylation and that this compound may be useful in preventing inflammatory arthritis.

  11. Tofogliflozin, A Highly Selective Inhibitor of SGLT2 Blocks Proinflammatory and Proapoptotic Effects of Glucose Overload on Proximal Tubular Cells Partly by Suppressing Oxidative Stress Generation.

    PubMed

    Ishibashi, Y; Matsui, T; Yamagishi, S

    2016-03-01

    Ninety percent of glucose filtered by the glomerulus is reabsorbed by a sodium-glucose cotransporter 2 (SGLT2), which is mainly expressed on S1 and S2 segment of renal proximal tubules. Since SGLT-2-mediated glucose reabsorption is increased under diabetic conditions, selective inhibition of SGLT2 is a potential therapeutic target for the treatment of diabetes. We have recently shown that an inhibitor of SGLT2 has anti-inflammatory and antifibrotic effects on experimental diabetic nephropathy partly by suppressing advanced glycation end products formation and oxidative stress generation in the kidney. However, the direct effects of SGLT2 inhibitor on tubular cell damage remain unclear. In this study, we investigated the effects of tofogliflozin, a highly selective inhibitor of SGLT2 on oxidative stress generation, inflammatory and proapoptotic reactions in cultured human proximal tubular cells exposed to high glucose. Tofogliflozin dose-dependently suppressed glucose entry into tubular cells. High glucose exposure (30 mM) for 4 and 24 h significantly increased oxidative stress generation in tubular cells, which were suppressed by the treatment of tofogliflozin or an antioxidant N-acetylcysteine (NAC). Monocyte chemoattractant protein-1 (MCP-1) gene expression and apoptotic cell death were induced by 4 h- and 8 day-exposure to high glucose, respectively, both of which were also blocked by tofogliflozin or NAC. The present study suggests that SGLT2-mediated glucose entry into tubular cells could stimulate oxidative stress and evoke inflammatory and proapoptotic reactions in this cell type. Blockade of glucose reabsorption in tubular cells by SGLT2 inhibitor might exert beneficial effects on tubulointerstitial damage in diabetic nephropathy. PMID:26158396

  12. Suppression of the invasive potential of Glioblastoma cells by mTOR inhibitors involves modulation of NFκB and PKC-α signaling.

    PubMed

    Chandrika, Goparaju; Natesh, Kumar; Ranade, Deepak; Chugh, Ashish; Shastry, Padma

    2016-01-01

    Glioblastoma (GBM) is the most aggressive type of brain tumors in adults with survival period <1.5 years of patients. The role of mTOR pathway is documented in invasion and migration, the features associated with aggressive phenotype in human GBM. However, most of the preclinical and clinical studies with mTOR inhibitors are focused on antiproliferative and cytotoxic activity in GBM. In this study, we demonstrate that mTOR inhibitors-rapamycin (RAP), temisirolimus (TEM), torin-1 (TOR) and PP242 suppress invasion and migration induced by Tumor Necrosis Factor-α (TNFα) and tumor promoter, Phorbol 12-myristate 13-acetate (PMA) and also reduce the expression of the TNFα and IL1β suggesting their potential to regulate factors in microenvironment that support tumor progression. The mTOR inhibitors significantly decreased MMP-2 and MMP-9 mRNA, protein and activity that was enhanced by TNFα and PMA. The effect was mediated through reduction of Protein kinase C alpha (PKC-α) activity and downregulation of NFκB. TNFα- induced transcripts of NFκB targets -VEGF, pentraxin-3, cathepsin-B and paxillin, crucial in invasion were restored to basal level by these inhibitors. With limited therapeutic interventions currently available for GBM, our findings are significant and suggest that mTOR inhibitors may be explored as anti-invasive drugs for GBM treatment. PMID:26940200

  13. Suppression of the invasive potential of Glioblastoma cells by mTOR inhibitors involves modulation of NFκB and PKC-α signaling

    PubMed Central

    Chandrika, Goparaju; Natesh, Kumar; Ranade, Deepak; Chugh, Ashish; Shastry, Padma

    2016-01-01

    Glioblastoma (GBM) is the most aggressive type of brain tumors in adults with survival period <1.5 years of patients. The role of mTOR pathway is documented in invasion and migration, the features associated with aggressive phenotype in human GBM. However, most of the preclinical and clinical studies with mTOR inhibitors are focused on antiproliferative and cytotoxic activity in GBM. In this study, we demonstrate that mTOR inhibitors-rapamycin (RAP), temisirolimus (TEM), torin-1 (TOR) and PP242 suppress invasion and migration induced by Tumor Necrosis Factor-α (TNFα) and tumor promoter, Phorbol 12-myristate 13-acetate (PMA) and also reduce the expression of the TNFα and IL1β suggesting their potential to regulate factors in microenvironment that support tumor progression. The mTOR inhibitors significantly decreased MMP-2 and MMP-9 mRNA, protein and activity that was enhanced by TNFα and PMA. The effect was mediated through reduction of Protein kinase C alpha (PKC-α) activity and downregulation of NFκB. TNFα- induced transcripts of NFκB targets -VEGF, pentraxin-3, cathepsin-B and paxillin, crucial in invasion were restored to basal level by these inhibitors. With limited therapeutic interventions currently available for GBM, our findings are significant and suggest that mTOR inhibitors may be explored as anti-invasive drugs for GBM treatment. PMID:26940200

  14. 3'-Azido-3'-deoxythymidine resistance suppressed by a mutation conferring human immunodeficiency virus type 1 resistance to nonnucleoside reverse transcriptase inhibitors.

    PubMed Central

    Larder, B A

    1992-01-01

    Nonnucleoside reverse transcriptase (NNRT) inhibitors (R82913; (+)-S-4,5,6,7-tetrahydro-9-chloro-5-methyl-6-(3-methyl-2-butenyl)- imidazo[4,5,1-jk][1,4]-benzodiazepin-2(1H)-thione; Cl-TIBO; and BI-RG-587, nevirapine) were used to select resistant human immunodeficiency virus type 1 (HIV-1) variants by passage in cell cultures of wild-type or 3'-azido-3'-deoxythymidine (zidovudine; AZT)-resistant strains. Similar to other NNRT inhibitors, Cl-TIBO induced a single mutation (Y181 to C) in reverse transcriptase (RT) that accounted for the resistance. BI-RG-587 induced a different mutation (V106-->A) in AZT resistance backgrounds. A series of viable HIV-1 variants was constructed by site-directed mutagenesis of the RT, which harbored multiple drug resistance mutations, including Y181 to C. HIV-1 that was co-resistant to NNRT inhibitors and 2',3'-dideoxyinosine resulted when a 2',3'-dideoxyinosine resistance mutation (L74 to V) was also present in RT. By contrast, however, the Y181 to C mutation in an AZT resistance background significantly suppressed resistance to AZT, while it conferred resistance to NNRT inhibitors. However, the V106-->A substitution did not cause suppression of preexisting AZT resistance. Since certain combinations of nucleoside analogs and NNRT inhibitors might result in the development of co-resistance, careful analysis of clinical isolates obtained during combination therapy will be needed to determine the potential significance of these observations. PMID:1282792

  15. Suppression of CD4+ T lymphocyte activation in vitro and experimental encephalomyelitis in vivo by the phosphatidyl inositol 3-kinase inhibitor PIK-75.

    PubMed

    Acosta, Y Y; Montes-Casado, M; Aragoneses-Fenoll, L; Dianzani, U; Portoles, P; Rojo, J M

    2014-01-01

    Class IA phosphatidyl inositol-3 kinases (PI3-K) are important targets in cancer therapy and are essential to immune responses, particularly through costimulation by CD28 and ICOS. Thus, small PI3-K inhibitors are likely candidates to immune intervention. PIK-75 is an efficient inhibitor of the PI3-K p110alpha catalytic subunits that suppresses tumor growth, and its effects on immune and autoimmune responses should be studied. Here, we describe the effect of PIK-75 on different immune parameters in vitro and in vivo. PIK-75 at concentrations commonly used in vitro (≥0.1 μM) inhibited T and B cell activation by Concanavalin A and LPS, respectively, and survival of non-stimulated spleen cells. In naive CD4+ T lymphocytes, PIK-75 induced apoptosis of resting or activated cells that was prevented by caspase inhibitors. At low nanomolar concentrations (≤10 nM), PIK-75 inhibited naive CD4+ T cell proliferation, and IL-2 and IFN-gamma production induced by anti-CD3 plus anti-CD28. In activated CD4+ T blasts costimulated by ICOS, PIK-75 (less than 10 nM) inhibited IFN-gamma, IL-17A, or IL-21 secretion. Furthermore, PIK-75 (20 mg/kg p.o.) suppressed clinical symptoms in ongoing experimental autoimmune encephalomyelitis (EAE) and inhibited MOG-specific responses in vitro. Thus, PIK-75 is an efficient suppressor of EAE, modulating lymphocyte function and survival. PMID:24674679

  16. Cyclooxygenase-2 or tumor necrosis factor-α inhibitors attenuate the mechanotransductive effects of pulsed focused ultrasound to suppress mesenchymal stromal cell homing to healthy and dystrophic muscle

    PubMed Central

    Tebebi, Pamela A.; Burks, Scott R.; Kim, Saejeong J.; Williams, Rashida A.; Nguyen, Ben A.; Venkatesh, Priyanka; Frenkel, Victor; Frank, Joseph A.

    2014-01-01

    Maximal homing of infused stem cells to diseased tissue is critical for regenerative medicine. Pulsed focused ultrasound (pFUS) is a clinically relevant platform to direct stem cell migration. Through mechanotransduction, pFUS establishes local gradients of cytokines, chemokines, trophic factors (CCTF) and cell adhesion molecules (CAM) in treated skeletal muscle that subsequently infused mesenchymal stromal cells (MSC) can capitalize to migrate into the parenchyma. Characterizing molecular responses to mechanical pFUS effects revealed tumor necrosis factor-alpha (TNFα) drives cyclooxygenase-2 (COX2) signaling to locally increase CCTF/CAM that are necessary for MSC homing. pFUS failed to increase chemoattractants and induce MSC homing to treated muscle in mice pretreated with ibuprofen (non-specific COX inhibitor) or etanercept (TNFα inhibitor). pFUS-induced MSC homing was also suppressed in COX2-knockout mice, demonstrating ibuprofen blocked the mechanically-induced CCTF/CAM by acting on COX2. Anti-inflammatory drugs, including ibuprofen, are administered to muscular dystrophy (MD) patients and ibuprofen also suppressed pFUS-induced homing to muscle in a mouse model of MD. Drug interactions with cell therapies remain unexplored and are not controlled for during clinical cell therapy trials. This study highlights potentially negative drug-host interactions that suppress stem cell homing and could undermine cell-based approaches for regenerative medicine. PMID:25534849

  17. Histone deacetylase inhibitor sodium butyrate suppresses proliferation and promotes apoptosis in osteosarcoma cells by regulation of the MDM2–p53 signaling

    PubMed Central

    Xie, Chuhai; Wu, Boyi; Chen, Binwei; Shi, Qunwei; Guo, Jianhong; Fan, Ziwen; Huang, Yan

    2016-01-01

    Histone deacetylase inhibitors have been reported to induce tumor cell growth arrest, differentiation, and apoptosis. This study aimed to investigate the effects of one histone deacetylase inhibitor – sodium butyrate (SB) – on osteosarcoma (OS) cell proliferation and apoptosis and also the molecular mechanisms by which SB exerts regulatory effects on OS cells. U2OS and MG63 cells were treated with SB at various concentrations. Then, cell proliferation and apoptosis were determined by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide and flow cytometry assays, respectively; the expression of Ki67, Bax, Bcl-2, MDM2, and p53 proteins was determined by using Western blot assay. The results showed that SB suppressed proliferation in a concentration-dependent manner and promoted apoptosis of OS cells. In addition, SB enhanced p53 expression and decreased MDM2 expression, indicating that SB can regulate MDM2–p53 feedback loop. p53 inhibited proliferation and promoted apoptosis, whereas MDM2 promoted proliferation and suppressed apoptosis, which indicated that functional effect of SB on OS cell lines at least in part depended on the MDM2–p53 signaling. We also explored the effect of SB on OS cells in vivo and found that SB suppressed the growth of OS cells with no noticeable effect on activity and body weight of mice in vivo. These findings will offer new clues for OS development and progression and offer SB as a potent targeted agent for OS treatment. PMID:27445491

  18. Suppression of PRKAR1A expression enhances anti-proliferative and apoptotic effects of protein kinase inhibitors and chemotherapeutic drugs on cholangiocarcinoma cells.

    PubMed

    Loilome, Watcharin; Juntana, Sirinun; Pinitsoontorn, Chadamas; Namwat, Nisana; Tassaneeyakul, Wichittra; Yongvanit, Puangrat

    2012-01-01

    Suppression of protein kinase A regulatory subunit 1 alpha (PRKAR1A) has been proven to inhibit cholangiocarcinoma (CCA) cell growth and enhance apoptosis. In the present study, we aimed to determine synergistic and/or additive effects of chemotherapeutic agents, including protein kinase inhibitors (i.e. sorafenib, sunitinib, gefitinib, Met inhibitor) and conventional chemotherapeutic drugs (i.e. 5-fluorouracil, doxorubicin, paclitaxel, gemcitabine), in PRKARIA knockdown CCA cell lines. The results revealed that PRKAR1A suppressed CCA cell lines demonstrated enhanced sensitivity to some chemotherapeutic drugs when compared to control cells. Moreover, PRKAR1A knockdown in combination with either sorafenib or 5-fluorouracil increased apoptotic effects on CCA cell lines. Therefore, selective inhibition of PRKAR1A appears to enhance the growth inhibitory effects of chemotherapeutic drugs as well as induce apoptotic cell death. Our findings suggest that additional suppression of PRKAR1A expression may increase the efficacy of conventional CCA chemotherapeutic treatment. Clinical studies in CCA patients now need to be conducted. PMID:23480756

  19. Histone deacetylase inhibitor sodium butyrate suppresses proliferation and promotes apoptosis in osteosarcoma cells by regulation of the MDM2-p53 signaling.

    PubMed

    Xie, Chuhai; Wu, Boyi; Chen, Binwei; Shi, Qunwei; Guo, Jianhong; Fan, Ziwen; Huang, Yan

    2016-01-01

    Histone deacetylase inhibitors have been reported to induce tumor cell growth arrest, differentiation, and apoptosis. This study aimed to investigate the effects of one histone deacetylase inhibitor - sodium butyrate (SB) - on osteosarcoma (OS) cell proliferation and apoptosis and also the molecular mechanisms by which SB exerts regulatory effects on OS cells. U2OS and MG63 cells were treated with SB at various concentrations. Then, cell proliferation and apoptosis were determined by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide and flow cytometry assays, respectively; the expression of Ki67, Bax, Bcl-2, MDM2, and p53 proteins was determined by using Western blot assay. The results showed that SB suppressed proliferation in a concentration-dependent manner and promoted apoptosis of OS cells. In addition, SB enhanced p53 expression and decreased MDM2 expression, indicating that SB can regulate MDM2-p53 feedback loop. p53 inhibited proliferation and promoted apoptosis, whereas MDM2 promoted proliferation and suppressed apoptosis, which indicated that functional effect of SB on OS cell lines at least in part depended on the MDM2-p53 signaling. We also explored the effect of SB on OS cells in vivo and found that SB suppressed the growth of OS cells with no noticeable effect on activity and body weight of mice in vivo. These findings will offer new clues for OS development and progression and offer SB as a potent targeted agent for OS treatment. PMID:27445491

  20. A direct thrombin inhibitor suppresses protein C activation and factor Va degradation in human plasma: Possible mechanisms of paradoxical enhancement of thrombin generation.

    PubMed

    Kamisato, Chikako; Furugohri, Taketoshi; Morishima, Yoshiyuki

    2016-05-01

    We have demonstrated that antithrombin (AT)-independent thrombin inhibitors paradoxically increase thrombin generation (TG) in human plasma in a thrombomodulin (TM)- and protein C (PC)-dependent manner. We determined the effects of AT-independent thrombin inhibitors on the negative-feedback system, activation of PC and production and degradation of factor Va (FVa), as possible mechanisms underlying the paradoxical enhancement of TG. TG in human plasma containing 10nM TM was assayed by means of the calibrated automated thrombography. As an index of PC activation, plasma concentration of activated PC-PC inhibitor complex (aPC-PCI) was measured. The amounts of FVa heavy chain and its degradation product (FVa(307-506)) were examined by western blotting. AT-independent thrombin inhibitors, melagatran and dabigatran (both at 25-600nM) and 3-30μg/ml active site-blocked thrombin (IIai), increased peak levels of TG. Melagatran, dabigatran and IIai significantly decreased plasma concentration of aPC-PCI complex at 25nM or more, 75nM or more, and 10 and 30μg/ml, respectively. Melagatran (300nM) significantly increased FVa and decreased FVa(307-506). In contrast, a direct factor Xa inhibitor edoxaban preferentially inhibited thrombin generation (≥25nM), and higher concentrations were required to inhibit PC activation (≥150nM) and FVa degradation (300nM). The present study suggests that the inhibitions of protein C activation and subsequent degradation of FVa and increase in FVa by antithrombin-independent thrombin inhibitors may contribute to the paradoxical TG enhancement, and edoxaban may inhibit PC activation and FVa degradation as a result of TG suppression. PMID:26974491

  1. Combination of YM155, a survivin suppressant with a STAT3 inhibitor: a new strategy to treat diffuse large B-cell lymphoma.

    PubMed

    Kaneko, Naoki; Kita, Aya; Yamanaka, Kentaro; Mori, Masamichi

    2013-09-01

    Survivin and STAT3 pathway have been reported to be important for the growth of diffuse large B-cell lymphoma (DLBCL) cells. Here we investigated the antitumor activity of sepantronium bromide (YM155), a survivin suppressant, in combination with STAT3 inhibitors in DLBCL cell lines in vitro. YM155 synergistically enhanced STAT3 inhibitors (AG490 and STA-21)-induced apoptosis in DLBCL cell lines. Moreover, rituximab, which shows inhibitory activity against STAT3, also sensitized DLBCL cell lines to YM155 regardless of sensitivity to rituximab. These results suggest that combining the inhibition of survivin with STAT3 pathway is an attractive and potentially effective way for the treatment of DLBCL. PMID:23746965

  2. Suppression of Ammonia Volatilization from Urea-Based Fertilizers Using Urease Inhibitors: A Reasonably Available Control Technology for Agriculture?

    NASA Astrophysics Data System (ADS)

    Robarge, W. P.

    2015-12-01

    Ammonia loss from fertilizers can impact formation of atmospheric aerosols, as well as contribute to nitrogen (N) deposition in terrestrial and aquatic ecosystems. Urea is the predominant form of N fertilizer used worldwide due to its high N content (46.6% N) and low cost. Once in contact with soil or vegetation, urea is hydrolyzed to ammonium via naturally occurring urease enzymes. Losses of N from surface applied urea as ammonia can exceed 30%. To address this issue, various physical and chemical mechanisms have been incorporated into granular urea. The most common approach is incorporation of urease inhibitors such as N-(n-butyl) thiophosphoric triamide (NBPT). We have been investigating ammonia volatilization from urea granules (+/- urease inhibitors) in various field and laboratory controlled experiments for the past several years. Laboratory experiments are conducted with a customized growth chamber system designed to continuously measure ammonia volatilization. Field measurements are conducted using a passive sampler technology with an acid-coated trap in PVC cylinders, or annular denuder technology using flow-through PVC chambers. Daily exchanges of acid-coated denuder tubes enhance the sensitivity of ammonia volatilization measurements for the urease-inhibitor treated product. Loss of N from commercial urea granules has ranged from 6 - ~ 35%, depending on ambient temperature. This loss typically occurs within the first 5-10 days under field conditions. Some urease-inhibitors can minimize loss of N via volatilization (< 5%) for up to 20+ days in the absence of a rainfall event. Visual observations have confirmed that on bare soil, treated or untreated urea granules quickly "dissolve" and move into the soil. The accompanying urease-inhibitor formulation moves with the urea continuing to provide protection against reaction with naturally occurring urease enzymes. Use of urease-inhibitors does not guarantee increased crop yields or NUE, but the consistency of

  3. Factor Xa Inhibitor Suppresses the Release of Phosphorylated HSP27 from Collagen-Stimulated Human Platelets: Inhibition of HSP27 Phosphorylation via p44/p42 MAP Kinase

    PubMed Central

    Tsujimoto, Masanori; Kuroyanagi, Gen; Matsushima-Nishiwaki, Rie; Kito, Yuko; Enomoto, Yukiko; Iida, Hiroki; Ogura, Shinji; Otsuka, Takanobu; Tokuda, Haruhiko; Kozawa, Osamu; Iwama, Toru

    2016-01-01

    Selective inhibitors of factor Xa (FXa) are widely recognized as useful therapeutic tools for stroke prevention in non-valvular atrial fibrillation or venous thrombosis. Thrombin, which is rapidly generated from pro-thrombin through the activation of factor X to FXa, acts as a potent activator of human platelets. Thus, the reduction of thrombin generation by FXa inhibitor eventually causes a suppressive effect on platelet aggregation. However, little is known whether FXa inhibitors directly affect the function of human platelets. We have previously reported that collagen induces the phosphorylation of heat shock protein 27 (HSP27), a low-molecular weight heat shock protein via Rac-dependent activation of p44/p42 mitogen-activated protein (MAP) kinase in human platelets, eventually resulting in the release of HSP27. In the present study, we investigated the direct effect of FXa inhibitor on the collagen-induced human platelet activation. Rivaroxaban as well as edoxaban significantly reduced the collagen-induced phosphorylation of both HSP27 and p44/p42 MAP kinase without affecting the platelet aggregation. Rivaroxaban significantly inhibited the release of phosphorylated HSP27 from collagen-stimulated platelets but not the secretion of platelet derived growth factor-AB. In patients administrated with rivaroxaban, the collagen-induced levels of phosphorylated HSP27 were markedly diminished after 2 days of administration, which failed to affect the platelet aggregation. These results strongly suggest that FXa inhibitor reduces the collagen-stimulated release of phosphorylated HSP27 from human platelets due to the inhibition of HSP27 phosphorylation via p44/p42 MAP kinase. PMID:26867010

  4. Pantoprazole, an FDA-approved proton-pump inhibitor, suppresses colorectal cancer growth by targeting T-cell-originated protein kinase.

    PubMed

    Zeng, Xiaoyu; Liu, Lin; Zheng, Mengzhu; Sun, Huimin; Xiao, Juanjuan; Lu, Tao; Huang, Guangqian; Chen, Pianpian; Zhang, Jianmin; Zhu, Feng; Li, Hua; Duan, Qiuhong

    2016-04-19

    T-cell-originated protein kinase (TOPK) is highly expressed in several cancer cells and promotes tumorigenesis and progression, and therefore, it is an important target for drug treatment of tumor. Pantoprazole (PPZ) was identified to be a TOPK inhibitor from FDA-approved drug database by structure based virtual ligand screening. Herein, the data indicated that pantoprazole inhibited TOPK activities by directly binding with TOPK in vitro and in vivo. Ex vivo studies showed that pantoprazole inhibited TOPK activities in JB6 Cl41 cells and HCT 116 colorectal cancer cells. Moreover, knockdown of TOPK in HCT 116 cells decreased their sensitivities to pantoprazole. Results of an in vivo study demonstrated that i.p. injection of pantoprazole in HCT 116 colon tumor-bearing mice effectively suppressed cancer growth. The TOPK downstream signaling molecule phospho-histone H3 in tumor tissues was also decreased after pantoprazole treatment. In short, pantoprazole can suppress growth of colorectal cancer cells as a TOPK inhibitor both in vitro and in vivo. PMID:26967058

  5. Pharmacologic suppression of JAK1/2 by JAK1/2 inhibitor AZD1480 potently inhibits IL-6-induced experimental prostate cancer metastases formation.

    PubMed

    Gu, Lei; Talati, Pooja; Vogiatzi, Paraskevi; Romero-Weaver, Ana L; Abdulghani, Junaid; Liao, Zhiyong; Leiby, Benjamin; Hoang, David T; Mirtti, Tuomas; Alanen, Kalle; Zinda, Michael; Huszar, Dennis; Nevalainen, Marja T

    2014-05-01

    Metastatic prostate cancer is lethal and lacks effective strategies for prevention or treatment, requiring novel therapeutic approaches. Interleukin-6 (IL-6) is a cytokine that has been linked with prostate cancer pathogenesis by multiple studies. However, the direct functional roles of IL-6 in prostate cancer growth and progression have been unclear. In the present study, we show that IL-6 is produced in distant metastases of clinical prostate cancers. IL-6-activated signaling pathways in prostate cancer cells induced a robust 7-fold increase in metastases formation in nude mice. We further show that IL-6 promoted migratory prostate cancer cell phenotype, including increased prostate cancer cell migration, microtubule reorganization, and heterotypic adhesion of prostate cancer cells to endothelial cells. IL-6-driven metastasis was predominantly mediated by Stat3 and to lesser extent by ERK1/2. Most importantly, pharmacologic inhibition of Jak1/2 by AZD1480 suppressed IL-6-induced signaling, migratory prostate cancer cell phenotypes, and metastatic dissemination of prostate cancer in vivo in nude mice. In conclusion, we demonstrate that the cytokine IL-6 directly promotes prostate cancer metastasis in vitro and in vivo via Jak-Stat3 signaling pathway, and that IL-6-driven metastasis can be effectively suppressed by pharmacologic targeting of Jak1/2 using Jak1/2 inhibitor AZD1480. Our results therefore provide a strong rationale for further development of Jak1/2 inhibitors as therapy for metastatic prostate cancer. PMID:24577942

  6. HMG-CoA reductase inhibitors induce apoptosis of lymphoma cells by promoting ROS generation and regulating Akt, Erk and p38 signals via suppression of mevalonate pathway

    PubMed Central

    Qi, X-F; Zheng, L; Lee, K-J; Kim, D-H; Kim, C-S; Cai, D-Q; Wu, Z; Qin, J-W; Yu, Y-H; Kim, S-K

    2013-01-01

    Statins, the inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, are widely used cholesterol-lowering drugs. Convincing evidence indicates that statins stimulate apoptotic cell death in several types of proliferating tumor cells in a cholesterol-lowering-independent manner. The objective here was to elucidate the molecular mechanism by which statins induce lymphoma cells death. Statins (atorvastatin, fluvastatin and simvastatin) treatment enhanced the DNA fragmentation and the activation of proapoptotic members such as caspase-3, PARP and Bax, but suppressed the activation of anti-apoptotic molecule Bcl-2 in lymphoma cells including A20 and EL4 cells, which was accompanied by inhibition of cell survival. Both increase in levels of reactive oxygen species (ROS) and activation of p38 MAPK and decrease in mitochondrial membrane potential and activation of Akt and Erk pathways were observed in statin-treated lymphoma cells. Statin-induced cytotoxic effects, DNA fragmentation and changes of activation of caspase-3, Akt, Erk and p38 were blocked by antioxidant (N-acetylcysteine) and metabolic products of the HMG-CoA reductase reaction, such as mevalonate, farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP). These results suggests that HMG-CoA reductase inhibitors induce lymphoma cells apoptosis by increasing intracellular ROS generation and p38 activation and suppressing activation of Akt and Erk pathways, through inhibition of metabolic products of the HMG-CoA reductase reaction including mevalonate, FPP and GGPP. PMID:23449454

  7. LDL suppresses angiogenesis through disruption of the HIF pathway via NF-κB inhibition which is reversed by the proteasome inhibitor BSc2118

    PubMed Central

    Doeppner, Thorsten R.; Niu, Feng; Li, Qiaochuan; Yang, Yanping; Kuckelkorn, Ulrike; Hagemann, Nina; Li, Wei; Hermann, Dirk M.; Dai, Yun; Zhou, Wen; Jin, Fengyan

    2015-01-01

    Since disturbance of angiogenesis predisposes to ischemic injuries, attempts to promote angiogenesis have been made to improve clinical outcomes of patients with many ischemic disorders. While hypoxia inducible factors (HIFs) stimulate vascular remodeling and angiogenesis, hyperlipidemia impairs angiogenesis in response to various pro-angiogenic factors. However, it remains uncertain how HIFs regulate angiogenesis under hyperlipidemia. Here, we report that exposure to low-density lipoprotein (LDL) suppressed in vitro angiogenesis of human brain microvascular endothelial cells. Whereas LDL exposure diminished expression of HIF-1α and HIF-2α induced by hypoxia, it inhibited DMOG- and TNFα-induced HIF-1α and HIF-2α expression in normoxia. Notably, in both hypoxia and normoxia, LDL markedly reduced expression of HIF-1β, a constitutively stable HIF subunit, an event associated with NF-κB inactivation. Moreover, knockdown of HIF-1β down-regulated HIF-1α and HIF-2α expression, in association with increased HIF-1α hydroxylation and 20S proteasome activity after LDL exposure. Significantly, the proteasome inhibitor BSc2118 prevented angiogenesis attenuation by LDL through restoring expression of HIFs. Together, these findings argue that HIF-1β might act as a novel cross-link between the HIF and NF-κB pathways in suppression of angiogenesis by LDL, while proteasome inhibitors might promote angiogenesis by reactivating this signaling cascade under hyperlipidemia. PMID:26388611

  8. Pantoprazole, an FDA-approved proton-pump inhibitor, suppresses colorectal cancer growth by targeting T-cell-originated protein kinase

    PubMed Central

    Sun, Huimin; Xiao, Juanjuan; Lu, Tao; Huang, Guangqian; Chen, Pianpian; Zhang, Jianmin; Zhu, Feng; Li, Hua; Duan, Qiuhong

    2016-01-01

    T-cell-originated protein kinase (TOPK) is highly expressed in several cancer cells and promotes tumorigenesis and progression, and therefore, it is an important target for drug treatment of tumor. Pantoprazole (PPZ) was identified to be a TOPK inhibitor from FDA-approved drug database by structure based virtual ligand screening. Herein, the data indicated that pantoprazole inhibited TOPK activities by directly binding with TOPK in vitro and in vivo. Ex vivo studies showed that pantoprazole inhibited TOPK activities in JB6 Cl41 cells and HCT 116 colorectal cancer cells. Moreover, knockdown of TOPK in HCT 116 cells decreased their sensitivities to pantoprazole. Results of an in vivo study demonstrated that i.p. injection of pantoprazole in HCT 116 colon tumor-bearing mice effectively suppressed cancer growth. The TOPK downstream signaling molecule phospho-histone H3 in tumor tissues was also decreased after pantoprazole treatment. In short, pantoprazole can suppress growth of colorectal cancer cells as a TOPK inhibitor both in vitro and in vivo. PMID:26967058

  9. Selective class I histone deacetylase inhibitors suppress persistent spontaneous nociception and thermal hypersensitivity in a rat model of bee venom-induced inflammatory pain.

    PubMed

    Yang, Fan; Yang, Yan; Wang, Yan; Yang, Fei; Li, Chun-Li; Wang, Xiao-Liang; Li, Zhen; Chen, Jun

    2015-10-25

    To confirm whether class I histone deacetylase inhibitors (HDACIs) are effective in relief of peripheral inflammatory pain, the effects of two selective inhibitors, MS-275 and MGCD0103, were studied in rats inflamed by subcutaneous (s.c.) injection of bee venom (BV). The BV test is characterized by displaying both persistent spontaneous nociception (PSN) and primary hypersensitivity. Intrathecal (i.t.) pre-treatment of either MS-275 or MGCD0103 with a single dose of 60 nmol/20 μL resulted in profound suppression of both PSN and primary thermal hypersensitivity but without significant influence upon the primary mechanical hypersensitivity and mirror-image thermal hypersensitivity. Moreover, the up-regulation of both HDAC1 and HDAC2 induced by s.c. BV injection was completely suppressed by i.t. pre-treatment of MS-275. The present results provide with another new line of evidence showing involvement of epigenetic regulation of chromatin structure by HDAC1/2-mediated histone hypoacetylation in the BV-induced PSN and thermal hypersensitivity and demonstrate the beneficial effects of class I HDACIs in prevention of peripheral inflammatory pain from occurring. PMID:26490061

  10. Suppression of asymmetric acid efflux and gravitropism in maize roots treated with auxin transport inhibitors of sodium orthovanadate

    NASA Technical Reports Server (NTRS)

    Mulkey, T. J.; Evans, M. L.

    1982-01-01

    In gravitropically stimulated roots of maize (Zea mays L., hybrid WF9 x 38MS), there is more acid efflux on the rapidly growing upper side than on the slowly growing lower side. In light of the Cholodny/Went hypothesis of gravitropism which states that gravitropic curvature results from lateral redistribution of auxin, the effects of auxin transport inhibitors on the development of acid efflux asymmetry and curvature in gravistimulated roots were examined. All the transport inhibitors tested prevented both gravitropism and the development of asymmetric acid efflux in gravistimulated roots. The results indicate that auxin redistribution may cause the asymmetry of acid efflux, a finding consistent with the Cholodny/Went hypothesis of gravitropism. As further evidence that auxin-induced acid efflux asymmetry may mediate gravitropic curvature, sodium orthovanadate, an inhibitor of auxin-induced H+ efflux was found to prevent both gravitropism and the development of asymmetric acid efflux in gravistimulated roots.

  11. Mangiferin, a novel nuclear factor kappa B-inducing kinase inhibitor, suppresses metastasis and tumor growth in a mouse metastatic melanoma model.

    PubMed

    Takeda, Tomoya; Tsubaki, Masanobu; Sakamoto, Kotaro; Ichimura, Eri; Enomoto, Aya; Suzuki, Yuri; Itoh, Tatsuki; Imano, Motohiro; Tanabe, Genzoh; Muraoka, Osamu; Matsuda, Hideaki; Satou, Takao; Nishida, Shozo

    2016-09-01

    Advanced metastatic melanoma, one of the most aggressive malignancies, is currently without reliable therapy. Therefore, new therapies are urgently needed. Mangiferin is a naturally occurring glucosylxanthone and exerts many beneficial biological activities. However, the effect of mangiferin on metastasis and tumor growth of metastatic melanoma remains unclear. In this study, we evaluated the effect of mangiferin on metastasis and tumor growth in a mouse metastatic melanoma model. We found that mangiferin inhibited spontaneous metastasis and tumor growth. Furthermore, mangiferin suppressed the nuclear translocation of nuclear factor kappa B (NF-κB) and expression of phosphorylated NF-κB-inducing kinase (NIK), inhibitor of kappa B kinase (IKK), and inhibitor of kappa B (IκB) and increases the expression of IκB protein in vivo. In addition, we found that mangiferin inhibited the expression of matrix metalloproteinases (MMPs) and very late antigens (VLAs) in vivo. Mangiferin treatment also increased the expression of cleaved caspase-3, cleaved Poly ADP ribose polymerase-1 (PARP-1), p53 upregulated modulator of apoptosis (PUMA), p53, and phosphorylated p53 proteins, and decreased the expression of Survivin and Bcl-associated X (Bcl-xL) proteins in vivo. These results indicate that mangiferin selectivity suppresses the NF-κB pathway via inhibition of NIK activation, thereby inhibiting metastasis and tumor growth. Importantly, the number of reported NIK selective inhibitors is limited. Taken together, our data suggest that mangiferin may be a potential therapeutic agent with a new mechanism of targeting NIK for the treatment of metastatic melanoma. PMID:27417526

  12. Suppression of Heat Shock Protein 27 Using OGX-427 Induces Endoplasmic Reticulum Stress and Potentiates Heat Shock Protein 90 Inhibitors to Delay Castrate-resistant Prostate Cancer

    PubMed Central

    Lamoureux, François; Thomas, Christian; Yin, Min-Jean; Fazli, Ladan; Zoubeidi, Amina; Gleave, Martin E.

    2014-01-01

    Background Although prostate cancer responds initially to androgen ablation therapies, progression to castration-resistant prostate cancer (CRPC) frequently occurs. Heat shock protein (Hsp) 90 inhibition is a rational therapeutic strategy for CRPC that targets key proteins such as androgen receptor (AR) and protein kinase B (Akt); however, most Hsp90 inhibitors trigger elevation of stress proteins like Hsp27 that confer tumor cell survival and treatment resistance. Objective We hypothesized that cotargeting the cytoprotective chaperone Hsp27 and Hsp90 would amplify endoplasmic reticulum (ER) stress and treatment-induced cell death in cancer. Design, setting, and participants Inducible and constitutive Hsp27 and other HSPs were measured by real-time reverse transcription-polymerase chain reaction and immunoblot assays. The combinations of OGX-427 with Hsp90 inhibitors were evaluated in vitro for LNCaP cell growth and apoptosis and in vivo in CRPC LNCaP xenograft models. Outcome measurements and statistical analysis Tumor volumes were compared using the Kruskal-Wallis test. Overall survival was analyzed using Kaplan-Meier curves, and statistical significance was assessed with the log-rank test. Results and limitations Hsp90 inhibitors induced expression of HSPs in tumor cells and tissues in a dose- and time-dependent manner; in particular, Hsp27 mRNA and protein levels increased threefold. In vitro, OGX-427 synergistically enhanced Hsp90 inhibitor-induced suppression of cell growth and induced apoptosis by 60% as measured by increased sub-G1 fraction and poly(ADP-ribose) polymerase cleavage. These biologic events were accompanied by decreased expression of HSPs, Akt, AR, and prostate-specific antigen, and induction of ER stress markers (cleaved activating transcription factor 6, glucose-regulated protein 78, and DNA-damage-inducible transcript 3). In vivo, OGX-427 potentiated the anticancer effects of Hsp90 inhibitor PF-04929113 (orally, 25 mg/kg) to inhibit tumor

  13. MPT0B098, a Microtubule Inhibitor, Suppresses JAK2/STAT3 Signaling Pathway through Modulation of SOCS3 Stability in Oral Squamous Cell Carcinoma.

    PubMed

    Peng, Hsuan-Yu; Cheng, Yun-Ching; Hsu, Yuan-Ming; Wu, Guan-Hsun; Kuo, Ching-Chuan; Liou, Jing-Ping; Chang, Jang-Yang; Jin, Shiow-Lian Catherine; Shiah, Shine-Gwo

    2016-01-01

    Microtubule inhibitors have been shown to inhibit Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signal transduction pathway in various cancer cells. However, little is known of the mechanism by which the microtubule inhibitors inhibit STAT3 activity. In the present study, we examined the effect of a novel small-molecule microtubule inhibitor, MPT0B098, on STAT3 signaling in oral squamous cell carcinoma (OSCC). Treatment of various OSCC cells with MPT0B098 induced growth inhibition, cell cycle arrest and apoptosis, as well as increased the protein level of SOCS3. The accumulation of SOCS3 protein enhanced its binding to JAK2 and TYK2 which facilitated the ubiquitination and degradation of JAK2 and TYK2, resulting in a loss of STAT3 activity. The inhibition of STAT3 activity led to sensitization of OSCC cells to MPT0B098 cytotoxicity, indicating that STAT3 is a key mediator of drug resistance in oral carcinogenesis. Moreover, the combination of MPT0B098 with the clinical drug cisplatin or 5-FU significantly augmented growth inhibition and apoptosis in OSCC cells. Taken together, our results provide a novel mechanism for the action of MPT0B098 in which the JAK2/STAT3 signaling pathway is suppressed through the modulation of SOCS3 protein level. The findings also provide a promising combinational therapy of MPT0B098 for OSCC. PMID:27367272

  14. MPT0B098, a Microtubule Inhibitor, Suppresses JAK2/STAT3 Signaling Pathway through Modulation of SOCS3 Stability in Oral Squamous Cell Carcinoma

    PubMed Central

    Peng, Hsuan-Yu; Cheng, Yun-Ching; Hsu, Yuan-Ming; Wu, Guan-Hsun; Kuo, Ching-Chuan; Liou, Jing-Ping; Chang, Jang-Yang

    2016-01-01

    Microtubule inhibitors have been shown to inhibit Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signal transduction pathway in various cancer cells. However, little is known of the mechanism by which the microtubule inhibitors inhibit STAT3 activity. In the present study, we examined the effect of a novel small-molecule microtubule inhibitor, MPT0B098, on STAT3 signaling in oral squamous cell carcinoma (OSCC). Treatment of various OSCC cells with MPT0B098 induced growth inhibition, cell cycle arrest and apoptosis, as well as increased the protein level of SOCS3. The accumulation of SOCS3 protein enhanced its binding to JAK2 and TYK2 which facilitated the ubiquitination and degradation of JAK2 and TYK2, resulting in a loss of STAT3 activity. The inhibition of STAT3 activity led to sensitization of OSCC cells to MPT0B098 cytotoxicity, indicating that STAT3 is a key mediator of drug resistance in oral carcinogenesis. Moreover, the combination of MPT0B098 with the clinical drug cisplatin or 5-FU significantly augmented growth inhibition and apoptosis in OSCC cells. Taken together, our results provide a novel mechanism for the action of MPT0B098 in which the JAK2/STAT3 signaling pathway is suppressed through the modulation of SOCS3 protein level. The findings also provide a promising combinational therapy of MPT0B098 for OSCC. PMID:27367272

  15. JQ1, an inhibitor of the epigenetic reader BRD4, suppresses the bidirectional MYC-AP4 axis via multiple mechanisms.

    PubMed

    Choi, Sung Kyung; Hong, Seong Hwi; Kim, Hyuk Soon; Shin, Chan Young; Nam, Suk Woo; Choi, Wahn Soo; Han, Jeung-Whan; You, Jueng Soo

    2016-02-01

    Bromodomain and extra-terminal domain (BET) family proteins are representative epigenetic modulators that read acetylated lysine residues and transfer cellular signals. Recently, the BET protein inhibitor JQ1 was developed and has been extensively studied in many cancer cell types. We demonstrated that JQ1 effectively suppressed the MYC-AP4 axis and induced antitumorigenic effects by targeting a bidirectional positive loop between MYC and AP4 which was first proposed in the present study. MYC and AP4 are the direct targets of BRD4, as demonstrated by chromatin immunoprecipitation (ChIP) assay and BRD4 loss-of-function experiments. Although inhibition of the MYC/MAC dimer suppressed AP4, the efficacy of suppression was not as effective as BRD4 inhibition. Notably, AP4 loss-of-function studies demonstrated that AP4 is a major critical target of JQ1 and that MYC is a novel downstream target of AP4, as demonstrated by AP4 binding to the MYC promoter. Taken together, our results suggest that the epigenetic reader BRD4 is a key mediator of the activated MYC-AP4 axis, which supports the possibility that targeting BET protein is a novel therapeutic strategy for MYC-AP4 axis-activated cancers. PMID:26573731

  16. HDAC inhibitors suppress c-Jun/Fra-1-mediated proliferation through transcriptionally downregulating MKK7 and Raf1 in neuroblastoma cells

    PubMed Central

    Tang, Xiaomei; Xia, Yong; He, Guozhen; Min, Zhiqun; Li, Chun; Xiong, Shiqiu; Shi, Zhi; Lu, Yongjian; Yuan, Zhongmin

    2016-01-01

    Activator protein 1 (AP-1) is a transcriptional factor composed of the dimeric members of bZIP proteins, which are frequently deregulated in human cancer cells. In this study, we aimed to identify an oncogenic AP-1 dimer critical for the proliferation of neuroblastoma cells and to investigate whether histone deacetylase inhibitors (HDACIs), a new generation of anticancer agents, could target the AP-1 dimer. We report here that HDACIs including trichostatin A, suberoylanilidehydroxamic acid, valproic acid and M344 can transcriptionally suppress both c-Jun and Fra-1, preceding their inhibition of cell growth. c-Jun preferentially interacting with Fra-1 as a heterodimer is responsible for AP-1 activity and critical for cell growth. Mechanistically, HDACIs suppress Fra-1 expression through transcriptionally downregulating Raf1 and subsequently decreasing MEK1/2-ERK1/2 activity. Unexpectedly, HDACI treatment caused MKK7 downregulation at both the protein and mRNA levels. Deletion analysis of the 5′-flanking sequence of the MKK7 gene revealed that a major element responsible for the downregulation by HDACI is located at −149 to −3 relative to the transcriptional start site. Knockdown of MKK7 but not MKK4 remarkably decreased JNK/c-Jun activity and proliferation, whereas ectopic MKK7-JNK1 reversed HDACI-induced c-Jun suppression. Furthermore, suppression of both MKK-7/c-Jun and Raf-1/Fra-1 activities was involved in the tumor growth inhibitory effects induced by SAHA in SH-SY5Y xenograft mice. Collectively, these findings demonstrated that c-Jun/Fra-1 dimer is critical for neuroblastoma cell growth and that HDACIs act as effective suppressors of the two oncogenes through transcriptionally downregulating MKK7 and Raf1. PMID:26734995

  17. Secretory Leukocyte Protease Inhibitor Suppresses the Inflammation and Joint Damage of Bacterial Cell Wall–Induced Arthritis

    PubMed Central

    Song, Xiao-yu; Zeng, Li; Jin, Wenwen; Thompson, John; Mizel, Diane E.; Lei, Ke-jian; Billinghurst, R.C.; Poole, A. Robin; Wahl, Sharon M.

    1999-01-01

    Disruption of the balance between proteases and protease inhibitors is often associated with pathologic tissue destruction. To explore the therapeutic potential of secretory leukocyte protease inhibitor (SLPI) in erosive joint diseases, we cloned, sequenced, and expressed active rat SLPI, which shares the protease-reactive site found in human SLPI. In a rat streptococcal cell wall (SCW)-induced model of inflammatory erosive polyarthritis, endogenous SLPI was unexpectedly upregulated at both mRNA and protein levels in inflamed joint tissues. Systemic delivery of purified recombinant rat SLPI inhibited joint inflammation and cartilage and bone destruction. Inflammatory pathways as reflected by circulating tumor necrosis factor α and nuclear factor κB activation and cartilage resorption detected by circulating levels of type II collagen collagenase-generated cleavage products were all diminished by SLPI treatment in acute and chronic arthritis, indicating that the action of SLPI may extend beyond inhibition of serine proteases. PMID:10449524

  18. [Suppressive effect of protein kinase C inhibitors on tumor cell function via phosphorylation of p53 protein in mice].

    PubMed

    Nakamura, K; Shinozuka, K; Kunitomo, M

    2000-12-01

    We examined the role of protein kinase C (PKC) in the phosphorylation of a p53 protein. Exposure to a protein kinase inhibitor, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H7), increased the phosphorylation of the wild type p53 protein, whereas exposure to a tumor promoter phorbol ester, 12-O-tetradecanoyl-phorbol-13-acetate (TPA), decreased it in vivo after incubation with mouse epidermal JB6 cells for 3 h. Exposure to a cAMP dependent protein kinase (PKA) activator, forskolin, did not decrease the phosphorylation of p53 protein. In the transient transfection/luciferase reporter transactivation assay, H7 slightly increased the mouse double minute (MDM) 2 reporter transactivation activity of the p53 protein after treatment for 24 h, whereas TPA completely blocked it. Exposure to H7 and a specific PKC inhibitor, bisindolylmaleimide (bis), dose-dependently reduced the lung-colonizing potential of highly metastatic B16-F10 mouse melanoma cells in syngeneic mice. These results suggest that the phosphorylation of the wild type p53 protein is inversely related to PKC activation, and also suggest that the phosphorylation of the p53 protein is involved in the function of its transcription factor. The PKC inhibitor may exhibit a potent anti-metastatic effect through the phosphorylation of wild type p53 protein and the activation of its function. PMID:11193387

  19. Novel acridine-based agents with topoisomerase II inhibitor activity suppress mesothelioma cell proliferation and induce apoptosis.

    PubMed

    Raza, Ahmad; Jacobson, Blake A; Benoit, Adam; Patel, Manish R; Jay-Dixon, Joe; Hiasa, Hiroshi; Ferguson, David M; Kratzke, Robert Arthur

    2012-08-01

    Human topoisomerase II (hTopoII) inhibitors are important chemotherapeutic agents in many different settings including treatment of malignant mesothelioma. Topoisomerase poisons, such as etoposide and doxorubicin, function by trapping the DNA-enzyme covalent complex producing DNA strand breaks which can ultimately lead to cancer cell death, as well as development of secondary malignancies. While these compounds have been used successfully in treating a wide variety of cancers, their use against mesothelioma has been limited. This study evaluates the anti-proliferative activity of series of acridine-based catalytic inhibitors of hTopoII using four mesothelioma cell lines (H513, H2372, H2461, and H2596). The results indicate these compounds inhibit malignant cell proliferation with EC(50) values ranging from 6.9 to 32 μM. Experiments are also performed that show that combination therapies may be used to increase potency. Based on the results of PARP cleavage and Guava Nexin assay, it is concluded that the primary mode of cell death is by apoptosis. The results are consistent with prior work involving pancreatic cancer and hTopoII catalytic inhibitors and suggest substituted acridines may hold promise in treating malignant mesothelioma. PMID:21789510

  20. Effects of suppression of estrogen action by the p450 aromatase inhibitor letrozole on bone mineral density and bone turnover in pubertal boys.

    PubMed

    Wickman, Sanna; Kajantie, Eero; Dunkel, Leo

    2003-08-01

    The essential role of estrogen (E) in regulation of developing peak bone mass in males was confirmed when young adult men were described who cannot respond to or produce E because of defective E receptor alpha or P-450 aromatase enzyme, respectively. These men had significantly reduced bone mineral density (BMD) despite normal or supranormal androgen concentrations, and E administration improved BMD in the men with aromatase deficiency, whereas testosterone (T) was ineffective. Because new P450 aromatase inhibitors may prove to be potential drugs in various growth disorders, the effect of suppression of E action on developing peak bone mass has to be closely evaluated. In this study, we explored the effects of suppression of E synthesis on bone metabolism in pubertal boys. A total of 23 boys with constitutional delay of puberty were randomized to receive T and placebo or T and a specific and potent P450 aromatase inhibitor, letrozole. We determined BMD in the lumbar spine and the femoral neck. Bone resorption was studied by measuring the serum concentration of cross-linked carboxyterminal telopeptide of type I collagen by two different methods (CTx and ICTP), and bone formation by determining the serum concentrations of carboxyterminal propeptide of type I procollagen (PICP), osteocalcin, and alkaline phosphatase. We demonstrated previously that, during treatment with T and placebo, the concentrations of androgens and E increased. During treatment with T and letrozole, the E concentrations remained at the pretreatment level, but the androgen concentrations increased; the increase in the T concentration was more than 5-fold higher than during treatment with T and placebo. We did not observe any significant differences in the changes in bone mineral content, BMD, or bone mineral apparent density, an estimate of true volumetric BMD, between the treated groups. Lumbar spine bone mineral apparent density increased in both treated groups; but in the T- plus letrozole

  1. A combination of YM-155, a small molecule survivin inhibitor, and IL-2 potently suppresses renal cell carcinoma in murine model.

    PubMed

    Guo, Kai; Huang, Peng; Xu, Naijin; Xu, Peng; Kaku, Haruki; Zheng, Shaobo; Xu, Abai; Matsuura, Eiji; Liu, Chunxiao; Kumon, Hiromi

    2015-08-28

    YM155, a small molecule inhibitor of the antiapoptotic protein survivin, has been developed as a potential anti-cancer drug. We investigated a combination therapy of YM155 and interleukin-2 (IL-2) in a mouse model of renal cell carcinoma (RCC). YM155 caused cell cycle arrest and apoptosis in renal cancer (RENCA) cells. Next, luciferase-expressing RENCA cells were implanted in the left kidney and the lung of BALB/c mice to develop RCC metastatic model. In this orthotopic renal and metastatic lung tumors models, YM155 and IL-2 additively decreased tumor weight, lung metastasis, and luciferin-stained tumor images. Also, the combination significantly suppressed regulatory T cells and myeloid-derived suppressor cells compared with single agent treatment. We suggest that a combination of YM155 and IL-2 can be tested as a potential therapeutic modality in patients with RCC. PMID:26023798

  2. A combination of YM-155, a small molecule survivin inhibitor, and IL-2 potently suppresses renal cell carcinoma in murine model

    PubMed Central

    Huang, Peng; Xu, Peng; Kaku, Haruki; Zheng, Shaobo; Xu, Abai; Matsuura, Eiji; Liu, Chunxiao; Kumon, Hiromi

    2015-01-01

    YM155, a small molecule inhibitor of the antiapoptotic protein survivin, has been developed as a potential anti-cancer drug. We investigated a combination therapy of YM155 and interleukin-2 (IL-2) in a mouse model of renal cell carcinoma (RCC). YM155 caused cell cycle arrest and apoptosis in renal cancer (RENCA) cells. Next, luciferase-expressing RENCA cells were implanted in the left kidney and the lung of BALB/c mice to develop RCC metastatic model. In this orthotopic renal and metastatic lung tumors models, YM155 and IL-2 additively decreased tumor weight, lung metastasis, and luciferin-stained tumor images. Also, the combination significantly suppressed regulatory T cells and myeloid-derived suppressor cells compared with single agent treatment. We suggest that a combination of YM155 and IL-2 can be tested as a potential therapeutic modality in patients with RCC. PMID:26023798

  3. Dasatinib suppression of medulloblastoma survival and migration is markedly enhanced by combining treatment with the aurora kinase inhibitor AT9283

    PubMed Central

    Petersen, William; Liu, Jingbo; Yuan, Liangping; Zhang, Hongying; Schneiderjan, Matthew; Cho, Yoon-Jae; MacDonald, Tobey J.

    2014-01-01

    Medulloblastoma (MB) expresses Src kinase, while aurora kinase A overexpression correlates with poor survival. We thus investigated novel combination treatment with dasatinib and AT9283, inhibitors of Src and aurora kinase, respectively, on MB growth in vitro and in vivo. Treatment with each drug significantly reduced cell viability and combined treatment markedly potentiated this response. AT9283 induced p53 expression, autophagy, and G2/M cell-cycle arrest, while combined treatment induced S phase arrest. Dasatinib treatment caused tumor regression in vivo. Activated Src was detected in 44% MB analyzed. We conclude that further evaluation of this combination therapy for MB is highly warranted. PMID:25107642

  4. DNA-dependent protein kinase catalytic subunit inhibitor reverses acquired radioresistance in lung adenocarcinoma by suppressing DNA repair.

    PubMed

    Li, Yong; Li, Hang; Peng, Wen; He, Xin-Yun; Huang, Min; Qiu, Dong; Xue, Ying-Bo; Lu, Liang

    2015-07-01

    The mechanisms underlying lung cancer radioresistance remain to be fully elucidated. The DNA repair pathway is a predominant target of radiotherapy, which is considered to be involved in the acquired radioresistance of cancer cells. The present study aimed to establish a radioresistant cell model using the A549 human lung cancer cell line, and to further investigate the potential mechanisms underlying the radioresistance. The A549R radioresistant lung cancer cell variant was established by exposing the parental A549 cells to repeated γ-ray irradiation at a total dose of 60 Gy. Colony formation assays were then used to determine cell survival following γ-ray exposure. The established radioresistant cells were subsequently treated with or without the NU7026 DNA-PKcs inhibitor. The levels of DNA damage were determined by counting the number of fluorescent γ-H2AX foci in the cells. The cellular capacity for DNA repair was assessed using antibodies for the detection of various DNA repair pathway proteins. The radioresistant sub-clones exhibited significantly decreased survival following NU7026 treatment, compared with the parental cells, as determined by colony formation assays (P<0.05), and this finding was found to be dose-dependent. Treatment with the DNA-dependent protein kinase (DNA-PK) inhibitor significantly reduced γ-H2AX foci formation (P<0.05) following acute radiation exposure in the radioresistant sub-clones, compared with the parental control cells. The decreased levels of γ-H2AX were accompanied by an increase in the percentage of apoptotic cells in the radioresistant cell line following post-radiation treatment with the DNA-PKcs inhibitor. The expression levels of proteins associated with the DNA repair pathway were altered markedly in the cells treated with NU7026. The results of the present study suggested that radioresistance may be associated with enhanced DNA repair following exposure to radiation, resulting in reduced apoptosis. Therefore, the

  5. Soluble inhibitors generated during hydrothermal pretreatment of oil palm mesocarp fiber suppressed the catalytic activity of Acremonium cellulase.

    PubMed

    Zakaria, Mohd Rafein; Hirata, Satoshi; Fujimoto, Shinji; Ibrahim, Izzudin; Hassan, Mohd Ali

    2016-01-01

    Oil palm mesocarp fiber was subjected to hydrothermal pretreatment under isothermal and non-isothermal conditions. The pretreated slurries were separated by filtration, pretreated liquids and solids were characterized. An enzymatic digestibility study was performed for both pretreated slurries and solids to understand the effect of soluble inhibitors generated during the pretreatment process. The highest glucose yield obtained from pretreated slurries was 70.1%, and gradually decreased with higher pretreatment severities. The highest glucose yield obtained in pretreated solids was 100%, after pretreatment at 210°C for 20min. In order to study the inhibitory effects of compounds generated during pretreatment with cellulase, technical grade solutions that mimic the pretreated liquid were prepared and their effect on Acremonium cellulase activity was monitored using Avicel. Xylo-oligomers and tannic acid were identified as powerful inhibitors of Acremonium cellulase, and the lowest hydrolysis rate of Avicel of 0.18g/g-glucose released/L/h was obtained from tannic acid. PMID:26524253

  6. Human C1-Inhibitor Suppresses Malaria Parasite Invasion and Cytoadhesion via Binding to Parasite Glycosylphosphatidylinositol and Host Cell Receptors.

    PubMed

    Mejia, Pedro; Diez-Silva, Monica; Kamena, Faustin; Lu, Fengxin; Fernandes, Stacey M; Seeberger, Peter H; Davis, Alvin E; Mitchell, James R

    2016-01-01

    Plasmodium falciparum-induced severe malaria remains a continuing problem in areas of endemicity, with elevated morbidity and mortality. Drugs targeting mechanisms involved in severe malaria pathology, including cytoadhesion of infected red blood cells (RBCs) to host receptors and production of proinflammatory cytokines, are still necessary. Human C1-inhibitor (C1INH) is a multifunctional protease inhibitor that regulates coagulation, vascular permeability, and inflammation, with beneficial effects in inflammatory disease models, including septic shock. We found that human C1INH, at therapeutically relevant doses, blocks severe malaria pathogenic processes by 2 distinct mechanisms. First, C1INH bound to glycan moieties within P. falciparum glycosylphosphatidylinositol (PfGPI) molecules on the parasite surface, inhibiting parasite RBC invasion and proinflammatory cytokine production by parasite-stimulated monocytes in vitro and reducing parasitemia in a rodent model of experimental cerebral malaria (ECM) in vivo. Second, C1INH bound to host CD36 and chondroitin sulfate A molecules, interfering with cytoadhesion of infected RBCs by competitive binding to these receptors in vitro and reducing sequestration in specific tissues and protecting against ECM in vivo. This study reveals that C1INH is a potential therapeutic antimalarial molecule able to interfere with severe-disease etiology at multiple levels through specific interactions with both parasite PfGPIs and host cell receptors. PMID:26347576

  7. A novel proteasome inhibitor suppresses tumor growth via targeting both 19S proteasome deubiquitinases and 20S proteolytic peptidases

    PubMed Central

    Liu, Ningning; Liu, Chunjiao; Li, Xiaofen; Liao, Siyan; Song, Wenbin; Yang, Changshan; Zhao, Chong; Huang, Hongbiao; Guan, Lixia; Zhang, Peiquan; Liu, Shouting; Hua, Xianliang; Chen, Xin; Zhou, Ping; Lan, Xiaoying; Yi, Songgang; Wang, Shunqing; Wang, Xuejun; Dou, Q. Ping; Liu, Jinbao

    2014-01-01

    The successful development of bortezomib-based therapy for treatment of multiple myeloma has established proteasome inhibition as an effective therapeutic strategy, and both 20S proteasome peptidases and 19S deubiquitinases (DUBs) are becoming attractive targets of cancer therapy. It has been reported that metal complexes, such as copper complexes, inhibit tumor proteasome. However, the involved mechanism of action has not been fully characterized. Here we report that (i) copper pyrithione (CuPT), an alternative to tributyltin for antifouling paint biocides, inhibits the ubiquitin-proteasome system (UPS) via targeting both 19S proteasome-specific DUBs and 20S proteolytic peptidases with a mechanism distinct from that of the FDA-approved proteasome inhibitor bortezomib; (ii) CuPT potently inhibits proteasome-specific UCHL5 and USP14 activities; (iii) CuPT inhibits tumor growth in vivo and induces cytotoxicity in vitro and ex vivo. This study uncovers a novel class of dual inhibitors of DUBs and proteasome and suggests a potential clinical strategy for cancer therapy. PMID:24912524

  8. CRM1 inhibitor S109 suppresses cell proliferation and induces cell cycle arrest in renal cancer cells.

    PubMed

    Liu, Xuejiao; Chong, Yulong; Liu, Huize; Han, Yan; Niu, Mingshan

    2016-03-01

    Abnormal localization of tumor suppressor proteins is a common feature of renal cancer. Nuclear export of these tumor suppressor proteins is mediated by chromosome region maintenance-1 (CRM1). Here, we investigated the antitumor eff ects of a novel reversible inhibitor of CRM1 on renal cancer cells. We found that S109 inhibits the CRM1-mediated nuclear export of RanBP1 and reduces protein levels of CRM1. Furthermore, the inhibitory eff ect of S109 on CRM1 is reversible. Our data demonstrated that S109 signifi cantly inhibits proliferation and colony formation of renal cancer cells. Cell cycle assay showed that S109 induced G1-phase arrest, followed by the reduction of Cyclin D1 and increased expression of p53 and p21. We also found that S109 induces nuclear accumulation of tumor suppressor proteins, Foxo1 and p27. Most importantly, mutation of CRM1 at Cys528 position abolished the eff ects of S109. Taken together, our results indicate that CRM1 is a therapeutic target in renal cancer and the novel reversible CRM1 inhibitor S109 can act as a promising candidate for renal cancer therapy. PMID:26937212

  9. A novel small-molecule inhibitor of influenza A virus acts by suppressing PA endonuclease activity of the viral polymerase

    PubMed Central

    Yuan, Shuofeng; Chu, Hin; Singh, Kailash; Zhao, Hanjun; Zhang, Ke; Kao, Richard Y. T.; Chow, Billy K. C.; Zhou, Jie; Zheng, Bo-Jian

    2016-01-01

    The RNA-dependent RNA polymerase of influenza A virus comprises conserved and independently-folded subdomains with defined functionalities. The N-terminal domain of the PA subunit (PAN) harbors the endonuclease function so that it can serve as a desired target for drug discovery. To identify a class of anti-influenza inhibitors that impedes PAN endonuclease activity, a screening approach that integrated the fluorescence resonance energy transfer based endonuclease inhibitory assay with the DNA gel-based endonuclease inhibitory assay was conducted, followed by the evaluation of antiviral efficacies and potential cytotoxicity of the primary hits in vitro and in vivo. A small-molecule compound ANA-0 was identified as a potent inhibitor against the replication of multiple subtypes of influenza A virus, including H1N1, H3N2, H5N1, H7N7, H7N9 and H9N2, in cell cultures. Combinational treatment of zanamivir and ANA-0 exerted synergistic anti-influenza effect in vitro. Intranasal administration of ANA-0 protected mice from lethal challenge and reduced lung viral loads in H1N1 virus infected BALB/c mice. In summary, ANA-0 shows potential to be developed to novel anti-influenza agents. PMID:26956222

  10. The 5-lipoxygenase inhibitor RF-22c potently suppresses leukotriene biosynthesis in cellulo and blocks bronchoconstriction and inflammation in vivo.

    PubMed

    Schaible, Anja M; Filosa, Rosanna; Krauth, Verena; Temml, Veronika; Pace, Simona; Garscha, Ulrike; Liening, Stefanie; Weinigel, Christina; Rummler, Silke; Schieferdecker, Sebastian; Nett, Markus; Peduto, Antonella; Collarile, Selene; Scuotto, Maria; Roviezzo, Fioretina; Spaziano, Giuseppe; de Rosa, Mario; Stuppner, Hermann; Schuster, Daniela; D'Agostino, Bruno; Werz, Oliver

    2016-07-15

    5-Lipoxygenase (5-LO) catalyzes the first two steps in leukotriene (LT) biosynthesis. Because LTs play pivotal roles in allergy and inflammation, 5-LO represents a valuable target for anti-inflammatory drugs. Here, we investigated the molecular mechanism, the pharmacological profile, and the in vivo effectiveness of the novel 1,2-benzoquinone-featured 5-LO inhibitor RF-22c. Compound RF-22c potently inhibited 5-LO product synthesis in neutrophils and monocytes (IC50⩾22nM) and in cell-free assays (IC50⩾140nM) without affecting 12/15-LOs, cyclooxygenase (COX)-1/2, or arachidonic acid release, in a specific and reversible manner, supported by molecular docking data. Antioxidant or iron-chelating properties were not evident for RF-22c and 5-LO-regulatory cofactors like Ca(2+) mobilization, ERK-1/2 activation, and 5-LO nuclear membrane translocation and interaction with 5-LO-activating protein (FLAP) were unaffected. RF-22c (0.1mg/kg; i.p.) impaired (I) bronchoconstriction in ovalbumin-sensitized mice challenged with acetylcholine, (II) exudate formation in carrageenan-induced paw edema, and (III) zymosan-induced leukocyte infiltration in air pouches. Taken together, RF-22c is a highly selective and potent 5-LO inhibitor in intact human leukocytes with pronounced effectiveness in different models of inflammation that warrants further preclinical analysis of this agent as anti-inflammatory drug. PMID:27157409

  11. A novel proteasome inhibitor suppresses tumor growth via targeting both 19S proteasome deubiquitinases and 20S proteolytic peptidases.

    PubMed

    Liu, Ningning; Liu, Chunjiao; Li, Xiaofen; Liao, Siyan; Song, Wenbin; Yang, Changshan; Zhao, Chong; Huang, Hongbiao; Guan, Lixia; Zhang, Peiquan; Liu, Shouting; Hua, Xianliang; Chen, Xin; Zhou, Ping; Lan, Xiaoying; Yi, Songgang; Wang, Shunqing; Wang, Xuejun; Dou, Q Ping; Liu, Jinbao

    2014-01-01

    The successful development of bortezomib-based therapy for treatment of multiple myeloma has established proteasome inhibition as an effective therapeutic strategy, and both 20S proteasome peptidases and 19S deubiquitinases (DUBs) are becoming attractive targets of cancer therapy. It has been reported that metal complexes, such as copper complexes, inhibit tumor proteasome. However, the involved mechanism of action has not been fully characterized. Here we report that (i) copper pyrithione (CuPT), an alternative to tributyltin for antifouling paint biocides, inhibits the ubiquitin-proteasome system (UPS) via targeting both 19S proteasome-specific DUBs and 20S proteolytic peptidases with a mechanism distinct from that of the FDA-approved proteasome inhibitor bortezomib; (ii) CuPT potently inhibits proteasome-specific UCHL5 and USP14 activities; (iii) CuPT inhibits tumor growth in vivo and induces cytotoxicity in vitro and ex vivo. This study uncovers a novel class of dual inhibitors of DUBs and proteasome and suggests a potential clinical strategy for cancer therapy. PMID:24912524

  12. Design of Group IIA Secreted/Synovial Phospholipase A2 Inhibitors: An Oxadiazolone Derivative Suppresses Chondrocyte Prostaglandin E2 Secretion

    PubMed Central

    Dong, Chang Zhi; Plocki, Stéphanie; Tsagris, Lydia; Rannou, François; Massicot, France; Djimdé, Atimé; El-Hayek, Elissar; Shi, Yiming; Heymans, Françoise; Gresh, Nohad; Chauvet, Caroline

    2010-01-01

    Group IIA secreted/synovial phospholipase A2 (GIIAPLA2) is an enzyme involved in the synthesis of eicosanoids such as prostaglandin E2 (PGE2), the main eicosanoid contributing to pain and inflammation in rheumatic diseases. We designed, by molecular modeling, 7 novel analogs of 3-{4-[5(indol-1-yl)pentoxy]benzyl}-4H-1,2,4-oxadiazol-5-one, denoted C1, an inhibitor of the GIIAPLA2 enzyme. We report the results of molecular dynamics studies of the complexes between these derivatives and GIIAPLA2, along with their chemical synthesis and results from PLA2 inhibition tests. Modeling predicted some derivatives to display greater GIIAPLA2 affinities than did C1, and such predictions were confirmed by in vitro PLA2 enzymatic tests. Compound C8, endowed with the most favorable energy balance, was shown experimentally to be the strongest GIIAPLA2 inhibitor. Moreover, it displayed an anti-inflammatory activity on rabbit articular chondrocytes, as shown by its capacity to inhibit IL-1β-stimulated PGE2 secretion in these cells. Interestingly, it did not modify the COX-1 to COX-2 ratio. C8 is therefore a potential candidate for anti-inflammatory therapy in joints. PMID:20531958

  13. Reactivating p53 functions by suppressing its novel inhibitor iASPP: a potential therapeutic opportunity in p53 wild-type tumors

    PubMed Central

    Dong, Peixin; Ihira, Kei; Hamada, Junichi; Watari, Hidemichi; Yamada, Takahiro; Hosaka, Masayoshi; Hanley, Sharon J.B.; Kudo, Masataka; Sakuragi, Noriaki

    2015-01-01

    Although mutational inactivation of p53 is found in 50% of all human tumors, a subset of tumors display defective p53 function, but retain wild-type (WT) p53. Here, direct and indirect mechanisms leading to the loss of WT p53 activities are discussed. We summarize the oncogenic roles of iASPP, an inhibitor of WT p53, in promoting proliferation, invasion, drug or radiation-resistance and metastasis. From the therapeutic view, we highlight promising perspectives of microRNA-124, peptide and small molecules that reduce or block iASPP for the treatment of cancer. High iASPP expression enhances proliferation, aggressive behavior, the resistance to radiation/chemotherapy and correlates with poor prognosis in a range of human tumors. Overexpression of iASPP accelerates tumorigenesis and invasion through p53-dependent and p53-independent mechanisms. MicroRNA-124 directly targets iASPP and represses the growth and invasiveness of cancer cells. The disruption of iASPP-p53 interaction by a p53-derived peptide A34 restores p53 function in cancer cells. The inhibition of iASPP phosphorylation with small molecules induces p53-dependent apoptosis and growth suppression. The mechanisms underlying aberrant expression of iASPP in human tumors should be further investigated. Reactivating WT p53 functions by targeting its novel inhibitor iASPP holds promise for potential therapeutic interventions in the treatment of WT p53-containing tumors. PMID:26343523

  14. ROCK inhibitor Y27632 promotes proliferation and diminishes apoptosis of marmoset induced pluripotent stem cells by suppressing expression and activity of caspase 3.

    PubMed

    Wu, Yuehong; Shu, Jianhong; He, Chengwen; Li, Min; Wang, Yujiong; Ou, Wenbin; He, Yulong

    2016-01-15

    Previous studies reported that Rho-associated kinase inhibitor Y27632 markedly diminishes human embryonic stem cell and induced pluripotent stem cell (iPSC) dissociation-induced apoptosis and increases cloning efficiency in a feeder-free culture system. However, the mechanisms by which Y27632 protects pluripotent stem cells from apoptosis remain unknown. In the present study, we tested the effects of Y27632 on single dissociated marmoset iPSCs in a feeder-free culture. The results showed that Y27632 promoted the number of cells proliferating after passage by single-cell dissociation in a dose-dependent manner. The Rho-associated kinase inhibitor Y27632 markedly increased the cloning efficiency of marmoset iPSCs without affecting their karyotype and the expression of pluripotency markers. Meanwhile, Y27632 markedly diminished apoptosis of the marmoset iPSCs under even more severe conditions by suppressing the expression and activity of caspase 3. Taken together, the present results suggest that this reagent is effective in improving the cultural system of primate iPSCs. PMID:26476594

  15. Assessing a peptidylic inhibitor-based therapeutic approach that simultaneously suppresses polyglutamine RNA- and protein-mediated toxicities in patient cells and Drosophila

    PubMed Central

    Zhang, Qian; Tsoi, Ho; Peng, Shaohong; Li, Pan P.; Lau, Kwok-Fai; Rudnicki, Dobrila D.; Ngo, Jacky Chi-Ki; Chan, Ho Yin Edwin

    2016-01-01

    ABSTRACT Polyglutamine (polyQ) diseases represent a group of progressive neurodegenerative disorders that are caused by abnormal expansion of CAG triplet nucleotides in disease genes. Recent evidence indicates that not only mutant polyQ proteins, but also their corresponding mutant RNAs, contribute to the pathogenesis of polyQ diseases. Here, we describe the identification of a 13-amino-acid peptide, P3, which binds directly and preferentially to long-CAG RNA within the pathogenic range. When administered to cell and Drosophila disease models, as well as to patient-derived fibroblasts, P3 inhibited expanded-CAG-RNA-induced nucleolar stress and suppressed neurotoxicity. We further examined the combined therapeutic effect of P3 and polyQ-binding peptide 1 (QBP1), a well-characterized polyQ protein toxicity inhibitor, on neurodegeneration. When P3 and QBP1 were co-administered to disease models, both RNA and protein toxicities were effectively mitigated, resulting in a notable improvement of neurotoxicity suppression compared with the P3 and QBP1 single-treatment controls. Our findings indicate that targeting toxic RNAs and/or simultaneous targeting of toxic RNAs and their corresponding proteins could open up a new therapeutic strategy for treating polyQ degeneration. PMID:26839389

  16. Assessing a peptidylic inhibitor-based therapeutic approach that simultaneously suppresses polyglutamine RNA- and protein-mediated toxicities in patient cells and Drosophila.

    PubMed

    Zhang, Qian; Tsoi, Ho; Peng, Shaohong; Li, Pan P; Lau, Kwok-Fai; Rudnicki, Dobrila D; Ngo, Jacky Chi-Ki; Chan, Ho Yin Edwin

    2016-03-01

    Polyglutamine (polyQ) diseases represent a group of progressive neurodegenerative disorders that are caused by abnormal expansion of CAG triplet nucleotides in disease genes. Recent evidence indicates that not only mutant polyQ proteins, but also their corresponding mutant RNAs, contribute to the pathogenesis of polyQ diseases. Here, we describe the identification of a 13-amino-acid peptide, P3, which binds directly and preferentially to long-CAG RNA within the pathogenic range. When administered to cell and Drosophila disease models, as well as to patient-derived fibroblasts, P3 inhibited expanded-CAG-RNA-induced nucleolar stress and suppressed neurotoxicity. We further examined the combined therapeutic effect of P3 and polyQ-binding peptide 1 (QBP1), a well-characterized polyQ protein toxicity inhibitor, on neurodegeneration. When P3 and QBP1 were co-administered to disease models, both RNA and protein toxicities were effectively mitigated, resulting in a notable improvement of neurotoxicity suppression compared with the P3 and QBP1 single-treatment controls. Our findings indicate that targeting toxic RNAs and/or simultaneous targeting of toxic RNAs and their corresponding proteins could open up a new therapeutic strategy for treating polyQ degeneration. PMID:26839389

  17. Icariside II, a natural mTOR inhibitor, disrupts aberrant energy homeostasis via suppressing mTORC1-4E-BP1 axis in sarcoma cells.

    PubMed

    Zhang, Chao; Yang, Lei; Geng, Ya-di; An, Fa-Liang; Xia, Yuan-Zheng; Guo, Chao; Luo, Jian-Guang; Zhang, Lu-Yong; Guo, Qing-Long; Kong, Ling-Yi

    2016-05-10

    The aberrant energy homeostasis that characterized by high rate of energy production (glycolysis) and energy consumption (mRNA translation) is associated with the development of cancer. As mammalian target of rapamycin (mTOR) is a critical regulator of aberrant energy homeostasis, it is an attractive target for anti-tumor intervention. The flavonoid compound Icariside II (IS) is a natural mTOR inhibitor derived from Epimedium. Koreanum. Herein, we evaluate the effect of IS on aberrant energy homeostasis. The reduction of glycolysis and mRNA translation in U2OS (osteosarcoma), S180 (fibrosarcoma) and SW1535 (chondrosarcoma) cells observed in our study, indicate that, IS inhibits aberrant energy homeostasis. This inhibition is found to be due to suppression of mammalian target of rapamycin complex 1 (mTORC1)-eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1) axis through blocking the assembly of mTORC1. Furthermore, IS inhibits the cap-dependent translation of c-myc through mTORC1-4E-BP1 axis which links the relationship between mRNA translation and glycolysis. Inhibition of aberrant energy homeostasis by IS, contributes to its in vitro and in vivo anti-proliferation activity. These data indicate that IS disrupts aberrant energy homeostasis of sarcoma cells through suppression of mTORC1-4E-BP1 axis, providing a novel mechanism of IS to inhibit cell proliferation in sarcoma cells. PMID:27056897

  18. Surfactants, Aromatic and Isoprenoid Compounds, and Fatty Acid Biosynthesis Inhibitors Suppress Staphylococcus aureus Production of Toxic Shock Syndrome Toxin 1▿

    PubMed Central

    McNamara, Peter J.; Syverson, Rae Ellen; Milligan-Myhre, Kathy; Frolova, Olga; Schroeder, Sarah; Kidder, Joshua; Hoang, Thanh; Proctor, Richard A.

    2009-01-01

    Menstrual toxic shock syndrome is a rare but potentially life-threatening illness manifest through the actions of Staphylococcus aureus toxic shock syndrome toxin 1 (TSST-1). Previous studies have shown that tampon additives can influence staphylococcal TSST-1 production. We report here on the TSST-1-suppressing activity of 34 compounds that are commonly used additives in the pharmaceutical, food, and perfume industries. Many of the tested chemicals had a minimal impact on the growth of S. aureus and yet were potent inhibitors of TSST-1 production. The TSST-1-reducing compounds included surfactants with an ether, amide, or amine linkage to their fatty acid moiety (e.g., myreth-3-myristate, Laureth-3, disodium lauroamphodiacetate, disodium lauramido monoethanolamido, sodium lauriminodipropionic acid, and triethanolamine laureth sulfate); aromatic compounds (e.g. phenylethyl and benzyl alcohols); and several isoprenoids and related compounds (e.g., terpineol and menthol). The membrane-targeting and -altering effects of the TSST-1-suppressing compounds led us to assess the activity of molecules that are known to inhibit fatty acid biosynthesis (e.g., cerulenin, triclosan, and hexachlorophene). These compounds also reduced S. aureus TSST-1 production. This study suggests that more additives than previously recognized inhibit the production of TSST-1. PMID:19223628

  19. The Stilbenoid Tyrosine Kinase Inhibitor, G6, Suppresses Jak2-V617F-mediated Human Pathological Cell Growth in Vitro and in Vivo*

    PubMed Central

    Kirabo, Annet; Embury, Jennifer; Kiss, Róbert; Polgár, Tímea; Gali, Meghanath; Majumder, Anurima; Bisht, Kirpal S.; Cogle, Christopher R.; Keserű, György M.; Sayeski, Peter P.

    2011-01-01

    Using structure-based virtual screening, we previously identified a novel stilbenoid inhibitor of Jak2 tyrosine kinase named G6. Here, we hypothesized that G6 suppresses Jak2-V617F-mediated human pathological cell growth in vitro and in vivo. We found that G6 inhibited proliferation of the Jak2-V617F expressing human erythroleukemia (HEL) cell line by promoting marked cell cycle arrest and inducing apoptosis. The G6-dependent increase in apoptosis levels was concomitant with increased caspase 3/7 activity and cleavage of PARP. G6 also selectively inhibited phosphorylation of STAT5, a downstream signaling target of Jak2. Using a mouse model of Jak2-V617F-mediated hyperplasia, we found that G6 significantly decreased the percentage of blast cells in the peripheral blood, reduced splenomegaly, and corrected a pathologically low myeloid to erythroid ratio in the bone marrow by eliminating HEL cell engraftment in this tissue. In addition, drug efficacy correlated with the presence of G6 in the plasma, marrow, and spleen. Collectively, these data demonstrate that the stilbenoid compound, G6, suppresses Jak2-V617F-mediated aberrant cell growth. As such, G6 may be a potential therapeutic lead candidate against Jak2-mediated, human disease. PMID:21127060

  20. Suppression of the senescence-associated secretory phenotype (SASP) in human fibroblasts using small molecule inhibitors of p38 MAP kinase and MK2.

    PubMed

    Alimbetov, Dauren; Davis, Terence; Brook, Amy J C; Cox, Lynne S; Faragher, Richard G A; Nurgozhin, Talgat; Zhumadilov, Zhaxybay; Kipling, David

    2016-04-01

    Senescent cells show an altered secretome profile termed the senescence-associated secretory phenotype (SASP). There is an increasing body of evidence that suggests that the accumulation of SASP-positive senescent cells in humans is partially causal in the observed shift to a low-level pro-inflammatory state in aged individuals. This in turn suggests the SASP as a possible therapeutic target to ameliorate inflammatory conditions in the elderly, and thus a better understanding of the signalling pathways underlying the SASP are required. Prior studies using the early generation p38 MAPK inhibitor SB203580 indicated that p38 signalling was required for the SASP. In this study, we extend these observations using two next-generation p38 inhibitors (UR-13756 and BIRB 796) that have markedly improved selectivity and specificity compared to SB203580, to strengthen the evidence that the SASP is p38-dependent in human fibroblasts. BIRB 796 has an efficacy and toxicity profile that has allowed it to reach Phase III clinical trials, suggesting its possible use to suppress the SASP in vivo. We also demonstrate for the first time a requirement for signalling through the p38 downstream MK2 kinase in the regulation of the SASP using two MK2 inhibitors. Finally, we demonstrate that a commercially-available multiplex cytokine assay technology can be used to detect SASP components in the conditioned medium of cultured fibroblasts from both young and elderly donors. This assay is a high-throughput, multiplex microtitre-based assay system that is highly sensitive, with very low sample requirements, allowing it to be used for low-volume human biological fluids. Our initial studies using existing multiplex plates form the basis for a "SASP signature" assay that could be used as a high-throughput system in a clinical study setting. Our findings therefore provide important steps towards the study of, and intervention in, the SASP in human ageing and age-related disease. PMID:26400758

  1. Pharmacologic inhibitors of IkappaB kinase suppress growth and migration of mammary carcinosarcoma cells in vitro and prevent osteolytic bone metastasis in vivo.

    PubMed

    Idris, Aymen I; Libouban, Hélène; Nyangoga, Hervé; Landao-Bassonga, Euphemie; Chappard, Daniel; Ralston, Stuart H

    2009-08-01

    The NF-kappaB signaling pathway is known to play an important role in the regulation of osteoclastic bone resorption and cancer cell growth. Previous studies have shown that genetic inactivation of IkappaB kinase (IKK), a key component of NF-kappaB signaling, inhibits osteoclastogenesis, but the effects of pharmacologic IKK inhibitors on osteolytic bone metastasis are unknown. Here, we studied the effects of the IKK inhibitors celastrol, BMS-345541, parthenolide, and wedelolactone on the proliferation and migration of W256 cells in vitro and osteolytic bone destruction in vivo. All compounds tested inhibited the growth and induced apoptosis of W256 cells as evidenced by caspase-3 activation and nuclear morphology. Celastrol, BMS-345541, and parthenolide abolished IL1beta and tumor necrosis factor alpha-induced IkappaB phosphorylation and prevented nuclear translocation of NF-kappaB and DNA binding. Celastrol and parthenolide but not BMS-345541 prevented the activation of both IKKalpha and IKKbeta, and celastrol inhibited IKKalpha/beta activation by preventing the phosphorylation of TAK1, a key receptor-associated factor upstream of IKK. Celastrol and parthenolide markedly reduced the mRNA expression of matrix metalloproteinase 9 and urinary plasminogen activator, and inhibited W256 migration. Administration of celastrol or parthenolide at a dose of 1 mg/kg/day suppressed trabecular bone loss and reduced the number and size of osteolytic bone lesions following W256 injection in rats. Histomorphometric analysis showed that both compounds decreased osteoclast number and inhibited bone resorption. In conclusion, pharmacologic inhibitors of IKK are effective in preventing osteolytic bone metastasis in this model and might represent a promising class of agents to the prevention and treatment of metastatic bone disease associated with breast cancer. PMID:19671767

  2. Toll-like receptor 9 ligand D-type oligodeoxynucleotide D35 as a broad inhibitor for influenza A virus replication that is associated with suppression of neuraminidase activity.

    PubMed

    Yamada, Hiroshi; Nagase, Satoshi; Takahashi, Kazuo; Sakoda, Yoshihiro; Kida, Hiroshi; Okamoto, Shigefumi

    2016-05-01

    The most effective drugs available to treat influenza are neuraminidase (NA) inhibitors, which provide important additional measures for the control of influenza virus infections. However, since the emergence of NA inhibitor-resistant viruses may compromise the clinical utility of this class of anti-influenza agents, it is very important to develop new anti-influenza agents which target a different region in NA responsible for its sensitivity from that for NA inhibitors and could be used to treat NA inhibitors-resistant isolates. The oligodeoxynucleotide D35, multimerized and aggregated, suppressed replication of influenza A viruses except A/WSN/33 (WSN). The suppressive viral replication by D35 depended on G-terad and multimer formation. The range of the suppressive viral replication at the late stage, including virus assembly and release from infected cells, was much larger than that at the initial stage, viral attachment and entry. D35 suppressed NA activity of influenza A viruses. Furthermore, replacing the NA gene of A/Puerto Rico/8/34 (PR8), in which viral replication was inhibited by D35 at the late stage, with the NA gene from WSN, in which viral replication was not inhibited, eliminated the D35-dependent suppression. D35 showed an additive anti-influenza effect with oseltamivir. It was also effective in vivo. These results suggest that the influenza virus NA mainly contributes to the D35-suppressible virus release from infected cells at the late stage. In addition, because administration of D35 into the virus-infected mice suppressed viral replication and weight loss, clinical application of D35 could be considered. PMID:26923882

  3. DC120, a novel AKT inhibitor, preferentially suppresses nasopharyngeal carcinoma cancer stem-like cells by downregulating Sox2

    PubMed Central

    Tang, Jun; Yang, Fen; Feng, Gong-Kan; Chen, Wen-Dan; Wu, Xiao-Qi; Qian, Xiao-Jun; Ding, Ke; Zhu, Xiao-Feng

    2015-01-01

    Side population (SP) contains cancer stem-like cells (CSLCs). In this study, we characterized SP cells from nasopharyngeal carcinoma (NPC) cell lines and found that SP cells had a higher self-renewal ability in vitro and greater tumorigenicity in vivo. The AKT pathway was activated in NPC SP cells. DC120, a 2-pyrimidyl-5-amidothiazole inhibitor of the ATP binding site of AKT, inhibited phosphorylation of FKHRL1 and GSK-3β. DC120 inhibited SP fraction, the sphere-forming ability in vitro and growth of primary xenografts as well as secondary xenografts’ tumor recurrence. This inhibition was accompanied by reduced expression of stem-related gene Sox2 due to induction of p27 and miR-30a. A combination of DC120 and CDDP more effectively inhibited NPC cells compared with monotherapy in vitro and in vivo. Clinical evaluation of DC120 is warranted. PMID:25749514

  4. A Potent Systemically Active N-Acylethanolamine Acid Amidase Inhibitor that Suppresses Inflammation and Human Macrophage Activation.

    PubMed

    Ribeiro, Alison; Pontis, Silvia; Mengatto, Luisa; Armirotti, Andrea; Chiurchiù, Valerio; Capurro, Valeria; Fiasella, Annalisa; Nuzzi, Andrea; Romeo, Elisa; Moreno-Sanz, Guillermo; Maccarrone, Mauro; Reggiani, Angelo; Tarzia, Giorgio; Mor, Marco; Bertozzi, Fabio; Bandiera, Tiziano; Piomelli, Daniele

    2015-08-21

    Fatty acid ethanolamides such as palmitoylethanolamide (PEA) and oleoylethanolamide (OEA) are lipid-derived mediators that potently inhibit pain and inflammation by ligating type-α peroxisome proliferator-activated receptors (PPAR-α). These bioactive substances are preferentially degraded by the cysteine hydrolase, N-acylethanolamine acid amidase (NAAA), which is highly expressed in macrophages. Here, we describe a new class of β-lactam derivatives that are potent, selective, and systemically active inhibitors of intracellular NAAA activity. The prototype of this class deactivates NAAA by covalently binding the enzyme's catalytic cysteine and exerts profound anti-inflammatory effects in both mouse models and human macrophages. This agent may be used to probe the functions of NAAA in health and disease and as a starting point to discover better anti-inflammatory drugs. PMID:25874594

  5. Novel STAT3 phosphorylation inhibitors exhibit potent growth-suppressive activity in pancreatic and breast cancer cells.

    PubMed

    Lin, Li; Hutzen, Brian; Zuo, Mingxin; Ball, Sarah; Deangelis, Stephanie; Foust, Elizabeth; Pandit, Bulbul; Ihnat, Michael A; Shenoy, Satyendra S; Kulp, Samuel; Li, Pui-Kai; Li, Chenglong; Fuchs, James; Lin, Jiayuh

    2010-03-15

    The constitutive activation of signal transducer and activator of transcription 3 (STAT3) is frequently detected in most types of human cancer where it plays important roles in survival, drug resistance, angiogenesis, and other functions. Targeting constitutive STAT3 signaling is thus an attractive therapeutic approach for these cancers. We have recently developed novel small-molecule STAT3 inhibitors, known as FLLL31 and FLLL32, which are derived from curcumin (the primary bioactive compound of turmeric). These compounds are designed to bind selectively to Janus kinase 2 and the STAT3 Src homology-2 domain, which serve crucial roles in STAT3 dimerization and signal transduction. Here we show that FLLL31 and FLLL32 are effective inhibitors of STAT3 phosphorylation, DNA-binding activity, and transactivation in vitro, leading to the impediment of multiple oncogenic processes and the induction of apoptosis in pancreatic and breast cancer cell lines. FLLL31 and FLLL32 also inhibit colony formation in soft agar and cell invasion and exhibit synergy with the anticancer drug doxorubicin against breast cancer cells. In addition, we show that FLLL32 can inhibit the induction of STAT3 phosphorylation by IFNalpha and interleukin-6 in breast cancer cells. We also show that administration of FLLL32 can inhibit tumor growth and vascularity in chicken embryo xenografts as well as substantially reduce tumor volumes in mouse xenografts. Our findings highlight the potential of these new compounds and their efficacy in targeting pancreatic and breast cancers that exhibit constitutive STAT3 signaling. PMID:20215512

  6. LYTAK1, a novel TAK1 inhibitor, suppresses KRAS mutant colorectal cancer cell growth in vitro and in vivo.

    PubMed

    Zhou, Jundong; Zheng, Bing; Ji, Jiansong; Shen, Fei; Min, Han; Liu, Biao; Wu, Jinchang; Zhang, Shuyu

    2015-05-01

    KRAS mutation in colorectal cancer (CRC) activates transforming growth factor-β (TGF-β)-activated kinase 1 (TAK1) to promote tumor progression. In the current study, we explored the potential effect of LYTAK1, a novel TAK1 inhibitor, against KRAS mutant CRC cells in vitro and in vivo. We found that LYTAK1 dose-dependently inhibited KRAS mutant CRC cell (HT-29 and SW-620 lines) growth, and induced cell cycle G1-S arrest. Further, LYTAK1 activated apoptosis in HT-29 cells and SW-620 cells, and apoptosis inhibitors almost reversed LYTAK1-mediated growth inhibition. While in KRAS wild-type (WT) CRC cell lines (DLD-1 and HCT-116), LYTAK1 had almost no effect on cell growth, cell cycle progression, or cell apoptosis. In KRAS mutant HT-29 cells and SW-260 cells, LYTAK1 blocked TAK1 activation or phosphorylation at Thr-184/187. Activation of nuclear factor κB (NF-κB) in these cells, detected by phosphorylations of p65 and IκB kinase α (IKKα) as well as expression of NF-κB-regulated gene cyclin D1, was significantly inhibited by LYTAK1. Further, LYTAK1 treatment resulted in downregulation of β-catenin and Wnt response gene Axin 2, indicating Wnt inactivation. In vivo, oral LYTAK1 significantly inhibited HT-29 xenograft growth in nude mice. Together, these results show that LYTAK1 inhibits KRAS mutant CRC cell growth both in vitro and in vivo. LYTAK1 might be investigated as a novel agent against CRC with KRAS mutation. PMID:25524577

  7. Tissue Inhibitor of Matrix Metalloproteinases-1 Knockdown Suppresses the Proliferation of Human Adipose-Derived Stem Cells

    PubMed Central

    Zhang, Peihua; Li, Jin; Qi, Yawei; Tang, Xudong; Duan, Jianfeng; Liu, Li; Wu, Zeyong; Liang, Jie; Li, Jiangfeng; Wang, Xian; Zeng, Guofang; Liu, Hongwei

    2016-01-01

    Tissue inhibitor of metalloproteinases-1 (TIMP-1) is a multifunctional matrix metalloproteinase, and it is involved in the regulation of cell proliferation and apoptosis in various cell types. However, little is known about the effect of TIMP-1 expression on the proliferation of adipose-derived stem cells (ADSCs). Therefore, TIMP-1 expression in the ADSCs was firstly detected by western blotting, and TIMP-1 gene was knocked down by lentivirus-mediated shRNA. Cell proliferation was then evaluated by MTT assay and Ki67 staining, respectively. Cell cycle progression was determined by flow cytometry. The changes of p51, p21, cyclin E, cyclin-dependent kinase 2 (CDK2), and P-CDK2 caused by TIMP-1 knockdown were detected by western blotting. The results indicated that ADSCs highly expressed TIMP-1 protein, and the knockdown of TIMP-1 inhibited cell proliferation and arrested cell cycle progression at G1 phase in the ADSCs possibly through the upregulation of p53, p21, and P-CDK2 protein levels and concurrent downregulation of cyclin E and CDK2 protein levels. These findings suggest that TIMP-1 works as a positive regulator of cell proliferation in ADSCs. PMID:27239203

  8. Effective growth-suppressive activity of maternal embryonic leucine-zipper kinase (MELK) inhibitor against small cell lung cancer

    PubMed Central

    Inoue, Hiroyuki; Kato, Taigo; Olugbile, Sope; Tamura, Kenji; Chung, Suyoun; Miyamoto, Takashi; Matsuo, Yo; Salgia, Ravi; Nakamura, Yusuke; Park, Jae-Hyun

    2016-01-01

    Maternal embryonic leucine zipper kinase (MELK), that plays a critical role in maintenance of cancer stem cells (CSCs), is predominantly expressed in various types of human cancer including small cell lung cancer (SCLC). SCLC usually acquires resistance to anti-cancer drugs and portends dismal prognosis. We have delineated roles of MELK in development/progression of SCLC and examined anti-tumor efficacy of OTS167, a highly potent MELK inhibitor, against SCLC. MELK expression was highly upregulated in both SCLC cell lines and primary tumors. siRNA-mediated MELK knockdown induced significant growth inhibition in SCLC cell lines. Concordantly, treatment with OTS167 exhibited strong cytotoxicity against eleven SCLC cell lines with IC50 of < 10 nM. As similar to siRNA knockdown, OTS167 treatment induced cytokinetic defects with intercellular bridges, and in some cell lines we observed formation of neuronal protrusions accompanied with increase of a neuronal differentiation marker (CD56), indicating that the compound induced differentiation of cancer cells to neuron-like cells. Furthermore, the MELK inhibition decreased its downstream FOXM1 activity and Akt expression in SCLC cells, and led to apoptotic cell death. OTS167 appeared to be more effective to CSCs as measured by the sphere formation assay, thus MELK inhibition might become a promising treatment modality for SCLC. PMID:26871945

  9. Cinnamon and its Components Suppress Vascular Smooth Muscle Cell Proliferation by Up-Regulating Cyclin-Dependent Kinase Inhibitors.

    PubMed

    Kwon, Hyeeun; Lee, Jung-Jin; Lee, Ji-Hye; Cho, Won-Kyung; Gu, Min Jung; Lee, Kwang Jin; Ma, Jin Yeul

    2015-01-01

    Cinnamomum cassia bark has been used in traditional herbal medicine to treat a variety of cardiovascular diseases. However, the antiproliferative effect of cinnamon extract on vascular smooth muscle cells (VSMCs) and the corresponding restenosis has not been explored. Hence, after examining the effect of cinnamon extract on VSMC proliferation, we investigated the possible involvement of signal transduction pathways associated with early signal and cell cycle analysis, including regulatory proteins. Besides, to identify the active components, we investigated the components of cinnamon extract on VSMC proliferation. Cinnamon extract inhibited platelet-derived growth factor (PDGF)-BB-induced VSMC proliferation and suppressed the PDGF-stimulated early signal transduction. In addition, cinnamon extract arrested the cell cycle and inhibited positive regulatory proteins. Correspondingly, the protein levels of p21 and p27 not only were increased in the presence of cinnamon extract, also the expression of proliferating cell nuclear antigen (PCNA) was inhibited by cinnamon extract. Besides, among the components of cinnamon extract, cinnamic acid (CA), eugenol (EG) and cinnamyl alcohol significantly inhibited the VSMC proliferation. Overall, the present study demonstrates that cinnamon extract inhibited the PDGF-BB-induced proliferation of VSMCs through a G0/G1 arrest, which down-regulated the expression of cell cycle positive regulatory proteins by up-regulating p21 and p27 expression. PMID:26119954

  10. Small molecule inhibitor of c-Met (PHA665752) suppresses the growth of ovarian cancer cells and reverses cisplatin resistance.

    PubMed

    Li, Enze; Hu, Zheng; Sun, Yi; Zhou, Qi; Yang, Bin; Zhang, Zhiguo; Cao, Wenwu

    2016-06-01

    c-Met as a tyrosine-kinase receptor plays a major role in tumorigenesis, invasion, and metastatic spread of human tumors, including ovarian cancer. Expressing high levels of c-Met proteins is often associated with resistance to chemotherapy and an adverse prognosis. In this study, we have determined the effect of PHA665752, a small molecule inhibitor of c-Met proteins, with and without cisplatin and the role of c-Met in several ovarian cancer cell lines having high c-Met expression. The methyl thiazolyl tetrazolium (MTT) assay was used to detect cell proliferation, and apoptosis was evaluated by flow cytometry. Western blotting was carried out to determine protein expression levels. Gene silencing was used to detect the influence of c-Met gene silence on the resistance to cisplatin. Compared to more sensitive ovarian cancer cell lines SKOV3 and 3AO, we found that the expression of c-Met was significantly increased in SKOV3(DDP), OVCAR3, and OV-90 ovarian cancer cell lines, which were resistant to cisplatin. Our data indicated that cisplatin sustained activated phosphor-Met in SKOV3(DDP), OVCAR3, and OV-90 cell lines. We also observed a significant transient activation of c-Met phosphorylation in SKOV3 and 3AO cells. Treatment with PHA665752 inhibited c-Met expression inhibited cell growth, induced apoptosis, and enhanced cisplatin-induced proliferation inhibition and apoptosis in c-Met over-expressed cell lines. In addition, blocking c-Met expression with small interfering RNA (siRNA) overcame the resistance of cancer cells to cisplatin. Thus, blocking c-Met expression presents a promising therapeutic approach for ovarian cancer. PMID:26695152

  11. Identification of Tetraazacyclic Compounds as Novel Potent Inhibitors Antagonizing RORγt Activity and Suppressing Th17 Cell Differentiation

    PubMed Central

    Ding, Qingfeng; Zhao, Mei; Yu, Bolan; Bai, Chuan; Huang, Zhaofeng

    2015-01-01

    CD4+ T-helper cells that produce interleukin-17 (Th17 cells) are characterized as pathological T-helper cells in autoimmune diseases. Differentiation of human and mouse Th17 cells requires a key transcription regulator, retinoic acid receptor-related orphan receptor γt (RORγt), which is a potential therapeutic target for autoimmune diseases. To develop a therapeutic agent for Th17-mediated autoimmune diseases, we have established a high-throughput screening (HTS) assay for candidate screening, in which the luciferase activity in RORγt-LBD positive and negative Jurkat cells were analyzed to evaluate induction of RORγt activity by compounds. This technique was applied to screen a commercially-available drug-like chemical compound library (Enamine) which contains 20155 compounds. The screening identified 17 compounds that can inhibit RORγt function in the HTS screen system. Of these, three tetraazacyclic compounds can potently inhibit RORγt activity, and suppress Th17 differentiation and IL-17 production. These three candidate compounds could significantly attenuate the expression of the Il17a by 65%- 90%, and inhibit IL-17A secretion by 47%, 63%, and 74%, respectively. These compounds also exhibited a potent anti-RORγt activity, with EC50 values of 0.25 μM, 0.67 μM and 2.6 μM, respectively. Our data demonstrated the feasibility of targeting the RORγt to inhibit Th17 cell differentiation and function with these tetraazacyclic compounds, and the potential to improve the structure of these compounds for autoimmune diseases therapeutics. PMID:26368822

  12. Histone Deacetylase Inhibitor Romidepsin Induces HIV Expression in CD4 T Cells from Patients on Suppressive Antiretroviral Therapy at Concentrations Achieved by Clinical Dosing

    PubMed Central

    Wei, Datsen George; Chiang, Vicki; Fyne, Elizabeth; Balakrishnan, Mini; Barnes, Tiffany; Graupe, Michael; Hesselgesser, Joseph; Irrinki, Alivelu; Murry, Jeffrey P.; Stepan, George; Stray, Kirsten M.; Tsai, Angela; Yu, Helen; Spindler, Jonathan; Kearney, Mary; Spina, Celsa A.; McMahon, Deborah; Lalezari, Jacob; Sloan, Derek; Mellors, John; Geleziunas, Romas; Cihlar, Tomas

    2014-01-01

    Persistent latent reservoir of replication-competent proviruses in memory CD4 T cells is a major obstacle to curing HIV infection. Pharmacological activation of HIV expression in latently infected cells is being explored as one of the strategies to deplete the latent HIV reservoir. In this study, we characterized the ability of romidepsin (RMD), a histone deacetylase inhibitor approved for the treatment of T-cell lymphomas, to activate the expression of latent HIV. In an in vitro T-cell model of HIV latency, RMD was the most potent inducer of HIV (EC50 = 4.5 nM) compared with vorinostat (VOR; EC50 = 3,950 nM) and other histone deacetylase (HDAC) inhibitors in clinical development including panobinostat (PNB; EC50 = 10 nM). The HIV induction potencies of RMD, VOR, and PNB paralleled their inhibitory activities against multiple human HDAC isoenzymes. In both resting and memory CD4 T cells isolated from HIV-infected patients on suppressive combination antiretroviral therapy (cART), a 4-hour exposure to 40 nM RMD induced a mean 6-fold increase in intracellular HIV RNA levels, whereas a 24-hour treatment with 1 µM VOR resulted in 2- to 3-fold increases. RMD-induced intracellular HIV RNA expression persisted for 48 hours and correlated with sustained inhibition of cell-associated HDAC activity. By comparison, the induction of HIV RNA by VOR and PNB was transient and diminished after 24 hours. RMD also increased levels of extracellular HIV RNA and virions from both memory and resting CD4 T-cell cultures. The activation of HIV expression was observed at RMD concentrations below the drug plasma levels achieved by doses used in patients treated for T-cell lymphomas. In conclusion, RMD induces HIV expression ex vivo at concentrations that can be achieved clinically, indicating that the drug may reactivate latent HIV in patients on suppressive cART. PMID:24722454

  13. Inhibitor of growth 4 suppresses colorectal cancer growth and invasion by inducing G1 arrest, inhibiting tumor angiogenesis and reversing epithelial-mesenchymal transition.

    PubMed

    Qu, Hui; Yin, Hong; Yan, Su; Tao, Min; Xie, Yufeng; Chen, Weichang

    2016-05-01

    Previous studies have found that inhibitor of growth 4 (ING4), a tumor suppressor, is reduced in human colorectal cancer (CRC), and is inversely correlated with clinical Dukes' stage, histological grade, lymph node metastasis and microvessel density (MVD). However, its underlying mechanism remains undetermined. In the present study, we analyzed ING4 expression in a panel of human CRC cells using low (LS174T and SW480) and high (LoVo and SW620) metastatic cell lines. We demonstrated that both the low and high metastatic CRC cells exhibited a lower level of ING4 compared to the level in normal human colorectal mucous epithelial FHC cells. Furthermore, ING4 expression in high metastatic CRC cells was less than that in low metastatic CRC cells. We then generated a lentivirus construct expressing ING4 and green fluorescent protein (GFP), established a ING4-stably transgenic LoVo CRC cell line, and investigated the effect of lentiviral-mediated ING4 expression on high metastatic LoVo CRC cells. Gain-of-function studies revealed that ING4 significantly inhibited LoVo CRC cell growth and invasion in vitro and induced cell cycle G1 phase arrest. Moreover, ING4 obviously suppressed LoVo CRC subcutaneously xenografted tumor growth and reduced tumor MVD in vivo in athymic BALB/c nude mice. Mechanistically, ING4 markedly upregulated P21 and E-cadherin but downregulated cyclin E, interleukin (IL)-6, IL-8, vascular endothelial growth factor (VEGF), Snail1, N-cadherin and vimentin in the LoVo CRC cells. Our data provide compelling evidence that i) ING4 suppresses CRC growth possibly via induction of G1 phase arrest through upregulation of P21 cyclin-dependent kinase (CDK) inhibitor and downregulation of cyclin E as well as inhibition of tumor angiogenesis through reduction of IL-6, IL-8 and VEGF proangiogenic factors; ii) ING4 inhibits CRC invasion and metastasis probably via a switch from mesenchymal marker N-cadherin to epithelial marker E-cadherin through

  14. ZD6474, a Multitargeted Inhibitor for Receptor Tyrosine Kinases, Suppresses Growth of Gliomas Expressing an Epidermal Growth Factor Receptor Mutant, EGFRvIII, in the Brain

    PubMed Central

    Yiin, Jia-Jean; Hu, Bo; Schornack, Paul A.; Sengar, Raghvendra S.; Liu, Kun-wei; Feng, Haizhong; Lieberman, Frank S.; Chiou, Shih-Hwa; Sarkaria, Jann N.; Wiener, Erik C.; Ma, Hsin-I; Cheng, Shi-Yuan

    2010-01-01

    Epidermal growth factor receptor (EGFR) vIII is a mutated EGFR that is frequently overexpressed in glioblastomas and implicated in response to receptor tyrosine kinase inhibitors. In this study, we investigate the effect of ZD6474 (ZACTIMA, vandetanib), a dual inhibitor for vascular endothelial growth factor receptor 2 and EGFR on growth and angiogenesis of gliomas expressing EGFRvIII. We used two glioma xenograft models, U87MG cells overexpressing EGFRvIII and short-term cultured primary glioma GBM8 cells with EGFRvIII. ZD6474 inhibited tumor growth and angiogenesis and induced cell apoptosis in various brain gliomas. Moreover, significant inhibition of EGFRvIII-expressing U87MG and GBM8 gliomas was observed compared with their controls. Magnetic resonance imaging analysis using the apparent diffusion coefficient and three-dimensional T2*weighed measurements validated ZD6474 inhibition on tumor growth and angiogenesis in EGFRvIII-expressing GBM8 gliomas. Mechanistically, ZD6474 shows better inhibition of cell growth and survival of U87MG/EGFRvIII, GBM6, and GBM8 cells that express EGFRvIII than U87MG or GBM14 cells that have nondetectable EGFRvIII through attenuation of activated phosphorylation of signal transducer and activator of transcription 3, Akt, and Bcl-XL expression. Albeit in lesser extent, ZD6474 also displays suppressions of U87MG/EGFR and GBM12 cells that overexpress wild-type EGFR. Additionally, ZD6474 inhibits activation of extracellular signal-regulated kinase 1/2 in both types of cells, and expression of a constitutively active phosphoinositide 3-kinases partially rescued ZD6474 inhibition in U87MG/EGFRvIII cells. Taken together, these data show that ZD6474 significantly inhibited growth and angiogenesis of gliomas expressing EGFRvIII by specifically blocking EGFRvIII-activated signaling mediators, suggesting a potential application of ZD6474 in treatments for glioblastomas that overexpress EGFRvIII. PMID:20371720

  15. Inhibitors of Growth 1b Suppresses Peroxisome Proliferator-Activated Receptor-β/δ Expression Through Downregulation of Hypoxia-Inducible Factor 1α in Osteoblast Differentiation.

    PubMed

    Qu, Bo; Hong, Zhen; Gong, Kai; Sheng, Jun; Wu, Hong-Hua; Deng, Shao-Lin; Huang, Gang; Ma, Ze-Hui; Pan, Xian-Ming

    2016-04-01

    Bone formation, a highly regulated developmental process, involves osteoblast differentiation, which is controlled by different important transcription factors. Recent evidence has suggested possible negative regulation of inhibitors of growth (ING) 1b on the osteoblast marker expression. The aim of this study is to examine the detailed mechanism by which the activity of ING1b inhibits osteoblast differentiation. In the current study, we investigated the function and mechanism by which ING1b inhibits osteoblast differentiation using C3H10T1/2 mesenchymal stem cells and MC3T3-E1 preosteoblasts. Real-time polymerase chain reaction and Western blotting showed that ING1b was decreased during osteoblast differentiation and ING1b overexpression markedly decreased alkaline phosphatase (ALP) activity, runt-related transcription factor 2 (Runx2) expression, and collagen type 1 synthesis, whereas ING1b silencing significantly upregulated ALP activity, Runx2 expression, and collagen type 1 synthesis. Further studies indicated that ING1b suppressed the expression of peroxisome proliferator-activated receptor (PPAR)-β/δ in a hypoxia-inducible factor (HIF) 1α-dependent manner, while ING1b silencing significantly increased the expression of PPAR-β/δ and HIF1α. Moreover, PPAR-β/δ or HIF1α silencing significantly inhibited ALP activity, Runx2 expression, and collagen type 1 synthesis. These results demonstrated that ING1b is an important regulator of osteoblast differentiation and suppresses PPAR-β/δ. Our study may provide additional insight into osteoblast differentiation and offer a potential new molecular target for osteoporosis. PMID:26849833

  16. Small-molecule survivin inhibitor YM155 enhances radiosensitization in esophageal squamous cell carcinoma by the abrogation of G2 checkpoint and suppression of homologous recombination repair

    PubMed Central

    2014-01-01

    Background Survivin is overexpressed in cancer cells and plays a crucial role in apoptosis evasion. YM155, a small-molecule inhibitor of survivin, could enhance the cytotoxicity of various DNA-damaging agents. Here, we evaluated the radiosensitizaion potential of YM155 in human esophageal squamous cell carcinoma (ESCC). Methods Cell viability was determined by CCK8 assay. The radiosensitization effect of YM155 was evaluated by clonogenic survival and progression of tumor xenograft. Cell cycle progression was determined by flow cytometric analysis. Radiation-induced DNA double strand break (DSB) and homologous recombination repair (HRR) were detected by the staining of γ-H2AX and RAD51, respectively. Expression of survivin and cell cycle regulators was detected by Western blot analysis. Results YM155 induced radiosensitization in ESCC cell lines Eca109 and TE13, associated with the abrogation of radiation induced G2/M checkpoint, impaired Rad51 focus formation, and the prolongation of γ-H2AX signaling. G2/M transition markers, including the activation of cyclinB1/Cdc2 kinase and the suppression of Cdc2 Thr14/Tyr15 phosphorylation were induced by YM155 in irradiated cells. The combination of YM155 plus irradiation delayed the growth of ESCC tumor xenografts to a greater extent compared with either treatment modality alone. Conclusions Our findings suggest that the abrogation of G2 checkpoint and the inhibition of HRR contribute to radiosensitization by YM155 in ESCC cells. PMID:25139395

  17. A Novel Small-Molecule Inhibitor Targeting CREB-CBP Complex Possesses Anti-Cancer Effects along with Cell Cycle Regulation, Autophagy Suppression and Endoplasmic Reticulum Stress

    PubMed Central

    Lee, Jong Woo; Park, Hee Sun; Park, Sin-Aye; Ryu, Seung-Hee; Meng, Wuyi; Jürgensmeier, Juliane M.; Kurie, Jonathan M.; Hong, Waun Ki; Boyer, Julie L.; Herbst, Roy S.; Koo, Ja Seok

    2015-01-01

    Lung adenocarcinoma, the most common subtype of lung cancer, is the leading cause of cancer death worldwide. Despite attempts for the treatment of lung cancer which have been accumulating, promising new therapies are still needed. Here, we found that cyclic-AMP response element-binding protein (CREB)-CREB binding protein (CBP) transcription factors complex inhibitor, Naphthol AS-TR phosphate (NASTRp), is a potential therapeutic agent for lung cancer. We show that NASTRp inhibited oncogenic cell properties through cell cycle arrest with concomitant suppression of tumor-promoting autophagy with down-regulations of Atg5-12 and Atg7, and accumulation of p62 in human lung cancer cell lines. In addition, NASTRp induced expression of endoplasmic reticulum stress markers such as DDIT3/CHOP, and led to apoptosis along with Bim induction. These findings suggest that transcription factor/co-activator complex, CREB-CBP, can be a potential therapeutic target and its inhibition could be a novel therapeutic strategy for lung cancer. PMID:25897662

  18. Tyrosine kinase inhibitor suppresses coronary arteriosclerotic changes and vasospastic responses induced by chronic treatment with interleukin-1 beta in pigs in vivo.

    PubMed Central

    Ito, A; Shimokawa, H; Kadokami, T; Fukumoto, Y; Owada, M K; Shiraishi, T; Nakaike, R; Takayanagi, T; Egashira, K; Takeshita, A

    1995-01-01

    We recently demonstrated that chronic treatment with IL-1 beta induces coronary arteriosclerotic changes and vasospastic responses to autacoids in pigs in vivo and that those responses are importantly mediated by PDGF. The receptors for PDGF and other major growth factors are known to have tyrosine kinase activity. We therefore investigated the effects of a selective tyrosine kinase inhibitor, ST 638, on those responses induced by IL-1 beta in our swine model. Intimal thickening and coronary vasospastic responses to serotonin and histamine were induced at the site of the coronary artery where IL-1 beta was chronically and locally applied. These responses were significantly suppressed in a dose-dependent manner by cotreatment with ST 638. In addition, ST 494, which is an inactive form of ST 638, did not inhibit those responses. The treatment with ST 638 alone did not affect the coronary vasoconstricting responses to the autacoids. Immunoblotting using an antibody to phosphotyrosines confirmed the inhibitory effects of ST 638 on the tyrosine phosphorylations induced by IL-1 beta. These results thus suggest that tyrosine kinase activation may play an important role in mediating the effects of IL-1 beta, while also suggesting that ST 638 has an inhibitory effect on the arteriosclerotic changes and vasospastic responses to autacoids in our swine model in vivo. Images PMID:7657803

  19. The pan-inhibitor of Aurora kinases danusertib induces apoptosis and autophagy and suppresses epithelial-to-mesenchymal transition in human breast cancer cells

    PubMed Central

    Li, Jin-Ping; Yang, Yin-Xue; Liu, Qi-Lun; Zhou, Zhi-Wei; Pan, Shu-Ting; He, Zhi-Xu; Zhang, Xueji; Yang, Tianxin; Pan, Si-Yuan; Duan, Wei; He, Shu-Ming; Chen, Xiao-Wu; Qiu, Jia-Xuan; Zhou, Shu-Feng

    2015-01-01

    Danusertib (Danu) is a pan-inhibitor of Aurora kinases and a third-generation breakpoint cluster region-Abelson murine leukemia viral oncogene homolog 1 (Bcr-Abl) tyrosine kinase inhibitor, but its antitumor effect and underlying mechanisms in the treatment of human breast cancer remain elusive. This study aimed to investigate the effects of Danu on the growth, apoptosis, autophagy, and epithelial-to-mesenchymal transition (EMT) and the molecular mechanisms in human breast cancer MCF7 and MDA-MB-231 cells. The results demonstrated that Danu remarkably inhibited cell proliferation, induced apoptosis and autophagy, and suppressed EMT in both breast cancer cell lines. Danu arrested MCF7 and MDA-MB-231 cells in G2/M phase, accompanied by the downregulation of cyclin-dependent kinase 1 and cyclin B1 and upregulation of p21 Waf1/Cip1, p27 Kip1, and p53. Danu significantly decreased the expression of B-cell lymphoma-extra-large (Bcl-xl) and B-cell lymphoma 2 (Bcl-2), but increased the expression of Bcl-2-associated X protein (Bax) and p53-upregulated modulator of apoptosis (PUMA), and promoted the cleavage of caspases 3 and 9. Furthermore, Danu significantly increased the expression levels of the membrane-bound microtubule-associated protein 1A/1B-light chain 3 (LC3-II) and beclin 1 in breast cancer cells, two markers for autophagy. Danu induced the activation of p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinases 1 and 2 (Erk1/2) and inhibited the activation of protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathways in breast cancer cells. Treatment with wortmannin (a phosphatidylinositol 3-kinase inhibitor) markedly inhibited Danu-induced activation of p38 MAPK and conversion of cytosolic LC3-I to membrane-bound LC3-II. Pharmacological inhibition and small interfering RNA-mediated knockdown of p38 MAPK suppressed Akt activation, resulting in LC3-II accumulation and enhanced autophagy. Pharmacological inhibition

  20. Hes-1 SUMOylation by protein inhibitor of activated STAT1 enhances the suppressing effect of Hes-1 on GADD45α expression to increase cell survival

    PubMed Central

    2014-01-01

    Background Hairy and Enhancer of split 1 (Hes-1) is a transcriptional repressor that plays an important role in neuronal differentiation and development, but post-translational modifications of Hes-1 are much less known. In the present study, we aimed to investigate whether Hes-1 could be SUMO-modified and identify the candidate SUMO acceptors on Hes-1. We also wished to examine the role of the SUMO E3 ligase protein inhibitor of activated STAT1 (PIAS1) in SUMOylation of Hes-1 and the molecular mechanism of Hes-1 SUMOylation. Further, we aimed to identify the molecular target of Hes-1 and examine how Hes-1 SUMOylation affects its molecular target to affect cell survival. Results In this study, by using HEK293T cells, we have found that Hes-1 could be SUMO-modified and Hes-1 SUMOylation was greatly enhanced by the SUMO E3 ligase PIAS1 at Lys8, Lys27 and Lys39. Furthermore, Hes-1 SUMOylation stabilized the Hes-1 protein and increased the transcriptional suppressing activity of Hes-1 on growth arrest and DNA damage-inducible protein alpha (GADD45α) expression. Overexpression of GADD45α increased, whereas knockdown of GADD45αα expression decreased cell apoptosis. In addition, H2O2 treatment increased the association between PIAS1 and Hes-1 and enhanced the SUMOylation of Hes-1 for endogenous protection. Overexpression of Hes-1 decreased H2O2-induced cell death, but this effect was blocked by transfection of the Hes-1 triple sumo-mutant (Hes-1 3KR). Overexpression of PIAS1 further facilitated the anti-apoptotic effect of Hes-1. Moreover, Hes-1 SUMOylation was independent of Hes-1 phosphorylation and vice versa. Conclusions The present results revealed, for the first time, that Hes-1 could be SUMO-modified by PIAS1 and GADD45α is a novel target of Hes-1. Further, Hes-1 SUMOylation mediates cell survival through enhanced suppression of GADD45α expression. These results revealed a novel role of Hes-1 in addition to its involvement in Notch signaling. They also

  1. Durable pharmacological responses from the peptide ShK-186, a specific Kv1.3 channel inhibitor that suppresses T cell mediators of autoimmune disease.

    PubMed

    Tarcha, Eric J; Chi, Victor; Muñoz-Elías, Ernesto J; Bailey, David; Londono, Luz M; Upadhyay, Sanjeev K; Norton, Kayla; Banks, Amy; Tjong, Indra; Nguyen, Hai; Hu, Xueyou; Ruppert, Greg W; Boley, Scott E; Slauter, Richard; Sams, James; Knapp, Brian; Kentala, Dustin; Hansen, Zachary; Pennington, Michael W; Beeton, Christine; Chandy, K George; Iadonato, Shawn P

    2012-09-01

    The Kv1.3 channel is a recognized target for pharmaceutical development to treat autoimmune diseases and organ rejection. ShK-186, a specific peptide inhibitor of Kv1.3, has shown promise in animal models of multiple sclerosis and rheumatoid arthritis. Here, we describe the pharmacokinetic-pharmacodynamic relationship for ShK-186 in rats and monkeys. The pharmacokinetic profile of ShK-186 was evaluated with a validated high-performance liquid chromatography-tandem mass spectrometry method to measure the peptide's concentration in plasma. These results were compared with single-photon emission computed tomography/computed tomography data collected with an ¹¹¹In-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-conjugate of ShK-186 to assess whole-blood pharmacokinetic parameters as well as the peptide's absorption, distribution, and excretion. Analysis of these data support a model wherein ShK-186 is absorbed slowly from the injection site, resulting in blood concentrations above the Kv1.3 channel-blocking IC₅₀ value for up to 7 days in monkeys. Pharmacodynamic studies on human peripheral blood mononuclear cells showed that brief exposure to ShK-186 resulted in sustained suppression of cytokine responses and may contribute to prolonged drug effects. In delayed-type hypersensitivity, chronic relapsing-remitting experimental autoimmune encephalomyelitis, and pristane-induced arthritis rat models, a single dose of ShK-186 every 2 to 5 days was as effective as daily administration. ShK-186's slow distribution from the injection site and its long residence time on the Kv1.3 channel contribute to the prolonged therapeutic effect of ShK-186 in animal models of autoimmune disease. PMID:22637724

  2. Raf kinase inhibitor protein suppresses nuclear factor-κB-dependent cancer cell invasion at the level of matrix metalloproteinase expression but not cell migration

    PubMed Central

    Beshir, Anwar B.; Ren, Gang; Magpusao, Anniefer N.; Barone, Lauren M.; Yeung, Kam C.; Fenteany, Gabriel

    2010-01-01

    Accumulating evidence suggests that Raf kinase inhibitor protein (RKIP), which negatively regulates multiple signaling cascades including the Raf and nuclear factor κB (NF-κB) pathways, functions as a metastasis suppressor. However, the basis for this activity is not clear. We investigated this question in a panel of breast cancer, colon cancer and melanoma cell lines. We found that RKIP negatively regulated the invasion of the different cancer cells through three-dimensional extracellular matrix barriers by controlling the expression of matrix metalloproteinases (MMPs), particularly, MMP-1 and MMP-2. Silencing of RKIP expression resulted in a highly invasive phenotype and dramatically increased levels of MMP-1 and MMP-2 expression, while overexpression of RKIP decreased cancer cell invasion in vitro and metastasis in vivo of murine tumor allografts. Knockdown of MMP-1 or MMP-2 in RKIP-knockdown cells reverted their invasiveness to normal. In contrast, when examining migration of the different cancer cells in a two-dimensional, barrier-less environment, we found that RKIP had either a positive regulatory activity or no activity, but in no case a negative one (as would be expected if RKIP suppressed metastasis at the level of cell migration itself). Therefore, RKIP’s function as a metastasis suppressor appears to arise from its ability to negatively regulate expression of specific MMPs, and thus invasion through barriers, and not from a direct effect on the raw capacity of cells to move. The NF-κB pathway, but not the Raf pathway, appeared to positively control the invasion of breast cancer cells. A regulatory loop involving an opposing relationship between RKIP and the NF-κB pathway may control the level of MMP expression and cell invasion. PMID:20855151

  3. Combination of AG490, a Jak2 inhibitor, and methylsulfonylmethane synergistically suppresses bladder tumor growth via the Jak2/STAT3 pathway.

    PubMed

    Joung, Youn Hee; Na, Yoon Mi; Yoo, Young Bum; Darvin, Pramod; Sp, Nipin; Kang, Dong Young; Kim, Sang Yoon; Kim, Hong Sup; Choi, Yoon Hee; Lee, Hak Kyo; Park, Kyung Do; Cho, Byung Wook; Kim, Heui Soo; Park, Jong Hwan; Yang, Young Mok

    2014-03-01

    Human urinary bladder cancer is the fifth most common cancer, with a worldwide estimate of about two million patients. Recurrence after complete transurethral prostatic resection is the most important problem in therapy. Combination therapy is a new approach in the treatment of cancers that do not respond to current therapies. These therapies have many advantages over conventional therapies, such as fewer side-effects and greater efficiency. Research efforts using natural compounds for the elimination or growth suppression of the cancer arise from studies on methylsulfonylmethane (MSM). MSM is a natural sulfur compound with no side-effects. AG490 is a tyrosine kinase inhibitor that has been extensively used for inhibiting Jak2 in vitro and in vivo. In our study, the combinatorial effect of these two agents on human bladder cancer cell lines and xenografts was analyzed. We observed that the combination of AG490 and MSM inhibited cancer cell viability and cell migration in vitro. This combination inhibited VEGF mRNA expression in bladder cancer cell lines. In vivo experiments showed that oral administration of AG490 and MSM combination significantly inhibited the growth of tumor xenografts in mice. Our study clearly demonstrates that the predominant effect of this combination is the reduction of signaling molecules including STAT3, STAT5b, IGF-1R, VEGF and VEGF-R2 which are involved in the growth, progression and metastasis of human bladder cancer. The anti-metastatic ability of this drug combination is confirmed using metastatic animal models. Therefore, this combination could have the effect of genesistasis and powerful anticancer effects against bladder cancer. PMID:24402583

  4. Nimesulide, a cyclooxygenase-2 selective inhibitor, suppresses obesity-related non-alcoholic fatty liver disease and hepatic insulin resistance through the regulation of peroxisome proliferator-activated receptor γ

    PubMed Central

    Tsujimoto, Shunsuke; Kishina, Manabu; Koda, Masahiko; Yamamoto, Yasutaka; Tanaka, Kohei; Harada, Yusuke; Yoshida, Akio; Hisatome, Ichiro

    2016-01-01

    Cyclooxygenase (COX)-2 selective inhibitors suppress non-alcoholic fatty liver disease (NAFLD); however, the precise mechanism of action remains unknown. The aim of this study was to examine how the COX-2 selective inhibitor nimesulide suppresses NAFLD in a murine model of high-fat diet (HFD)-induced obesity. Mice were fed either a normal chow diet (NC), an HFD, or HFD plus nimesulide (HFD-nime) for 12 weeks. Body weight, hepatic COX-2 mRNA expression and triglyceride accumulation were significantly increased in the HFD group. Triglyceride accumulation was suppressed in the HFD-nime group. The mRNA expression of hepatic peroxisome proliferator-activated receptor γ (PPARγ) and the natural PPARγ agonist 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) were significantly increased in the HFD group and significantly suppressed in the HFD-nime group. Glucose metabolism was impaired in the HFD group compared with the NC group, and it was significantly improved in the HFD-nime group. In addition, the plasma insulin levels in the HFD group were increased compared with those in the NC group, and were decreased in the HFD-nime group. These results indicate that HFD-induced NAFLD is mediated by the increased hepatic expression of COX-2. We suggest that the production of 15d-PGJ2, which is mediated by COX-2, induces NAFLD and hepatic insulin resistance by activating PPARγ. Furthermore, the mRNA expression of tissue inhibitor of metalloproteinases-1 (TIMP-1), procollagen-1 and monocyte chemoattractant protein-1 (MCP-1), as well as the number of F4/80-positive hepatic (Kupffer) cells, were significantly increased in the HFD group compared with the NC group, and they were reduced by nimesulide. In conclusion, COX-2 may emerge as a molecular target for preventing the development of NAFLD and insulin resistance in diet-related obesity. PMID:27431935

  5. From a natural product lead to the identification of potent and selective benzofuran-3-yl-(indol-3-yl)maleimides as glycogen synthase kinase 3beta inhibitors that suppress proliferation and survival of pancreatic cancer cells.

    PubMed

    Gaisina, Irina N; Gallier, Franck; Ougolkov, Andrei V; Kim, Ki H; Kurome, Toru; Guo, Songpo; Holzle, Denise; Luchini, Doris N; Blond, Sylvie Y; Billadeau, Daniel D; Kozikowski, Alan P

    2009-04-01

    Recent studies have demonstrated that glycogen synthase kinase 3beta (GSK-3beta) is overexpressed in human colon and pancreatic carcinomas, contributing to cancer cell proliferation and survival. Here, we report the design, synthesis, and biological evaluation of benzofuran-3-yl-(indol-3-yl)maleimides, potent GSK-3beta inhibitors. Some of these compounds show picomolar inhibitory activity toward GSK-3beta and an enhanced selectivity against cyclin-dependent kinase 2 (CDK-2). Selected GSK-3beta inhibitors were tested in the pancreatic cancer cell lines MiaPaCa-2, BXPC-3, and HupT3. We determined that some of these compounds, namely compounds 5, 6, 11, 20, and 26, demonstrate antiproliferative activity against some or all of the pancreatic cancer cells at low micromolar to nanomolar concentrations. We found that the treatment of pancreatic cancer cells with GSK-3beta inhibitors 5 and 26 resulted in suppression of GSK-3beta activity and a distinct decrease of the X-linked inhibitor of apoptosis (XIAP) expression, leading to significant apoptosis. The present data suggest a possible role for GSK-3beta inhibitors in cancer therapy, in addition to their more prominent applications in CNS disorders. PMID:19338355

  6. Small-molecule caspase inhibitors

    NASA Astrophysics Data System (ADS)

    Zhenodarova, S. M.

    2010-02-01

    The review considers low-molecular weight inhibitors of caspases, cysteine proteases being key contributors to apoptosis (programmed cell death). The inhibitors with aspartic acid residues or various heterocyclic systems (both synthetic and natural) are covered. Their possible mechanisms of action are discussed. Data on inhibitor structure-activity relationship studies are systematically surveyed. The interactions of the non-peptide fragments of an inhibitor with the enzymes are examined. Examples of the use of some inhibitors for apoptosis suppression are provided.

  7. A selective inhibitor of the immunoproteasome subunit LMP2 induces apoptosis in PC-3 cells and suppresses tumour growth in nude mice

    PubMed Central

    Wehenkel, M; Ban, J-O; Ho, Y-K; Carmony, K C; Hong, J T; Kim, K B

    2012-01-01

    Background: Although the proteasome is a validated anticancer target, the clinical application of its inhibitors has been limited because of inherent systemic toxicity. To broaden clinical utility of proteasome inhibitors as anticancer agents, it is critical to develop strategies to selectively target proteasomes in cancer cells. The immunoproteasome is an alternative form of the constitutive proteasome that is expressed at high levels in cancer tissues, but not in most normal cells in the body. Methods: To validate the immunoproteasome as a chemotherapeutic target, an immunoproteasome catalytic subunit LMP2-targeting inhibitor and siRNA were used. The sensitivity of PC-3 prostate cancer cells to these reagents was investigated using viability assays. Further, a xenograft model of prostate cancer was studied to test the in vivo effects of LMP2 inhibition. Results: A small molecule inhibitor of the immunoproteasome subunit LMP2, UK-101, induced apoptosis of PC-3 cells and resulted in significant inhibition (∼50–60%) of tumour growth in vivo. Interestingly, UK-101 did not block degradation of IκBα in PC-3 cells treated with TNF-α, suggesting that its mode of action may be different from that of general proteasome inhibitors, such as bortezomib, which block IκBα degradation. Conclusion: These results strongly suggest that the immunoproteasome has important roles in cancer cell growth and thus provide a rationale for targeting the immunoproteasome in the treatment of prostate cancer. PMID:22677907

  8. Nimesulide, a cyclooxygenase-2 selective inhibitor, suppresses obesity-related non-alcoholic fatty liver disease and hepatic insulin resistance through the regulation of peroxisome proliferator-activated receptor γ.

    PubMed

    Tsujimoto, Shunsuke; Kishina, Manabu; Koda, Masahiko; Yamamoto, Yasutaka; Tanaka, Kohei; Harada, Yusuke; Yoshida, Akio; Hisatome, Ichiro

    2016-09-01

    Cyclooxygenase (COX)-2 selective inhibitors suppress non-alcoholic fatty liver disease (NAFLD); however, the precise mechanism of action remains unknown. The aim of this study was to examine how the COX-2 selective inhibitor nimesulide suppresses NAFLD in a murine model of high-fat diet (HFD)‑induced obesity. Mice were fed either a normal chow diet (NC), an HFD, or HFD plus nimesulide (HFD-nime) for 12 weeks. Body weight, hepatic COX-2 mRNA expression and triglyceride accumulation were significantly increased in the HFD group. Triglyceride accumulation was suppressed in the HFD-nime group. The mRNA expression of hepatic peroxisome proliferator-activated receptor γ (PPARγ) and the natural PPARγ agonist 15-deoxy-Δ12,14-prostaglandin J2 (15d‑PGJ2) were significantly increased in the HFD group and significantly suppressed in the HFD-nime group. Glucose metabolism was impaired in the HFD group compared with the NC group, and it was significantly improved in the HFD-nime group. In addition, the plasma insulin levels in the HFD group were increased compared with those in the NC group, and were decreased in the HFD-nime group. These results indicate that HFD-induced NAFLD is mediated by the increased hepatic expression of COX-2. We suggest that the production of 15d-PGJ2, which is mediated by COX-2, induces NAFLD and hepatic insulin resistance by activating PPARγ. Furthermore, the mRNA expression of tissue inhibitor of metalloproteinases-1 (TIMP‑1), procollagen-1 and monocyte chemoattractant protein-1 (MCP-1), as well as the number of F4/80-positive hepatic (Kupffer) cells, were significantly increased in the HFD group compared with the NC group, and they were reduced by nimesulide. In conclusion, COX-2 may emerge as a molecular target for preventing the development of NAFLD and insulin resistance in diet-related obesity. PMID:27431935

  9. Suppression of human T cell proliferation by the caspase inhibitors, z-VAD-FMK and z-IETD-FMK is independent of their caspase inhibition properties

    SciTech Connect

    Lawrence, C.P.; Chow, S.C.

    2012-11-15

    The caspase inhibitors, benzyloxycarbony (Cbz)-l-Val-Ala-Asp (OMe)-fluoromethylketone (z-VAD-FMK) and benzyloxycarbonyl (Cbz)-Ile-Glu (OMe)-Thr-Asp (OMe)-FMK (z-IETD-FMK) at non-toxic doses were found to be immunosuppressive and inhibit human T cell proliferation induced by mitogens and IL-2 in vitro. Both caspase inhibitors were shown to block NF-κB in activated primary T cells, but have little inhibitory effect on the secretion of IL-2 and IFN-γ during T cell activation. However, the expression of IL-2 receptor α-chain (CD25) in activated T cells was inhibited by both z-VAD-FMK and z-IETD-FMK, whereas the expression of the early activated T cell marker, CD69 was unaffected. During primary T cell activation via the antigen receptor, both caspase-8 and caspase-3 were activated and processed to their respective subunits, but neither caspase inhibitors had any effect on the processing of these two caspases. In sharp contrast both caspase inhibitors readily blocked apoptosis and the activation of caspases during FasL-induced apoptosis in activated primary T cells and Jurkat T cells. Collectively, the results demonstrate that both z-VAD-FMK and z-IETD-FMK are immunosuppressive in vitro and inhibit T cell proliferation without blocking the processing of caspase-8 and caspase-3. -- Highlights: ► Caspase-8 and caspase-3 were activated during T cell activation and proliferation. ► T cell proliferation was blocked by caspase inhibitors. ► Caspase activation during T cell proliferation was not block by caspase inhibitors.

  10. A novel p38 mitogen activated protein kinase (MAPK) specific inhibitor suppresses respiratory syncytial virus and influenza A virus replication by inhibiting virus-induced p38 MAPK activation.

    PubMed

    Choi, Myung-Soo; Heo, Jinyuk; Yi, Chae-Min; Ban, Junsu; Lee, Noh-Jin; Lee, Na-Rae; Kim, Sang Won; Kim, Nam-Jung; Inn, Kyung-Soo

    2016-08-26

    Respiratory syncytial virus (RSV) and influenza A virus are leading causes of acute lower respiratory infectious disease. Respiratory diseases caused by RSV and influenza A virus result in serious economic burden and life-threatening disease for immunocompromised people. With the revelation that p38 mitogen-activated protein kinase (MAPK) activity in host cells is crucial for infection and replication of RSV and influenza A virus, inhibition of p38 MAPK activity has been suggested as a potential antiviral therapeutic strategy. However, the low selectivity and high toxicity of the p38 MAPK inhibitors necessitate the development of better inhibitors. Herein, we report the synthesis of a novel p38 MAPK inhibitor, NJK14047, with high kinase selectivity. In this work, it was demonstrated that NJK14047 inhibits RSV- and influenza A-mediated p38 MAPK activation in epithelial cells. Subsequently, NJK14047 treatment resulted in decreased viral replication and viral mRNA synthesis. In addition, secretion of interleukin-6 from infected cells was greatly diminished by NJK14047, suggesting that it can ameliorate immunopathological responses to RSV and influenza A. Collectively, the results suggest that NJK14047 has therapeutic potential to treat respiratory viral infection through the suppression of p38 MAPK activation, which is suggested to be an essential step for respiratory virus infection. PMID:27346133

  11. Synthetic Lethal Screen Demonstrates That a JAK2 Inhibitor Suppresses a BCL6-dependent IL10RA/JAK2/STAT3 Pathway in High Grade B-cell Lymphoma.

    PubMed

    Beck, Daniel; Zobel, Jenny; Barber, Ruth; Evans, Sian; Lezina, Larissa; Allchin, Rebecca L; Blades, Matthew; Elliott, Richard; Lord, Christopher J; Ashworth, Alan; Porter, Andrew C G; Wagner, Simon D

    2016-08-01

    We demonstrate the usefulness of synthetic lethal screening of a conditionally BCL6-deficient Burkitt lymphoma cell line, DG75-AB7, with a library of small molecules to determine survival pathways suppressed by BCL6 and suggest mechanism-based treatments for lymphoma. Lestaurtinib, a JAK2 inhibitor and one of the hits from the screen, repressed survival of BCL6-deficient cells in vitro and reduced growth and proliferation of xenografts in vivo BCL6 deficiency in DG75-AB7 induced JAK2 mRNA and protein expression and STAT3 phosphorylation. Surface IL10RA was elevated by BCL6 deficiency, and blockade of IL10RA repressed STAT3 phosphorylation. Therefore, we define an IL10RA/JAK2/STAT3 pathway each component of which is repressed by BCL6. We also show for the first time that JAK2 is a direct BCL6 target gene; BCL6 bound to the JAK2 promoter in vitro and was enriched by ChIP-seq. The place of JAK2 inhibitors in the treatment of diffuse large B-cell lymphoma has not been defined; we suggest that JAK2 inhibitors might be most effective in poor prognosis ABC-DLBCL, which shows higher levels of IL10RA, JAK2, and STAT3 but lower levels of BCL6 than GC-DLBCL and might be usefully combined with novel approaches such as inhibition of IL10RA. PMID:27268052

  12. The IRE1/bZIP60 pathway and Bax inhibitor 1 suppress systemic accumulation of potyviruses and potexviruses in Arabidopsis and N. benthamiana plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The inositol requiring enzyme (IRE1) is an endoplasmic reticulum (ER) stress sensor and when activated it splices the bZIP60 mRNA producing a truncated transcription factor that upregulates expression of genes involved in the unfolded protein response (UPR). Bax inhibitor 1 (BI-1) is another ER stre...

  13. Hydroxamic Acid and Benzoic Acid-Based STAT3 Inhibitors Suppress Human Glioma and Breast Cancer Phenotypes In Vitro and In Vivo.

    PubMed

    Yue, Peibin; Lopez-Tapia, Francisco; Paladino, David; Li, Yifei; Chen, Chih-Hong; Namanja, Andrew T; Hilliard, Tyvette; Chen, Yuan; Tius, Marcus A; Turkson, James

    2016-02-01

    STAT3 offers an attractive target for cancer therapy, but small-molecule inhibitors with appealing pharmacologic properties have been elusive. Here, we report hydroxamic acid-based and benzoic acid-based inhibitors (SH5-07 and SH4-54, respectively) with robust bioactivity. Both inhibitors blocked STAT3 DNA-binding activity in vitro and in human glioma, breast, and prostate cancer cells and in v-Src-transformed murine fibroblasts. STAT3-dependent gene transcription was blocked along with Bcl-2, Bcl-xL, Mcl-1, cyclin D1, c-Myc, and survivin expression. Nuclear magnetic resonance analysis of STAT3-inhibitor complexes defined interactions with the SH2 and DNA-binding domains of STAT3. Ectopic expression of the SH2 domain in cells was sufficient to counter the STAT3-inhibitory effects of SH4-54. Neither compound appreciably affected STAT1 or STAT5 DNA-binding activities, STAT3-independent gene transcription, or activation of a panel of oncogenic kinases in malignant cells. Each compound decreased the proliferation and viability of glioma, breast, and prostate cancer cells and v-Src-transformed murine fibroblasts harboring constitutively active STAT3. Further, in mouse xenograft models of glioma and breast cancer, administration of SH5-07 or SH4-54 effectively inhibited tumor growth. Our results offer preclinical proof of concept for SH5-07 and SH4-54 as candidates for further development as cancer therapeutics. PMID:26088127

  14. PI3K/Akt/mTOR pathway inhibitors enhance radiosensitivity in radioresistant prostate cancer cells through inducing apoptosis, reducing autophagy, suppressing NHEJ and HR repair pathways.

    PubMed

    Chang, L; Graham, P H; Hao, J; Ni, J; Bucci, J; Cozzi, P J; Kearsley, J H; Li, Y

    2014-01-01

    The PI3K/Akt/mTOR pathway has a central role in cancer metastasis and radiotherapy. To develop effective therapeutics to improve radiosensitivity, understanding the possible pathways of radioresistance involved and the effects of a combination of the PI3K/Akt/mTOR inhibitors with radiotherapy on prostate cancer (CaP) radioresistant cells is needed. We found that compared with parent CaP cells, CaP-radioresistant cells demonstrated G0/G1 and S phase arrest, activation of cell cycle check point, autophagy and DNA repair pathway proteins, and inactivation of apoptotic proteins. We also demonstrated that compared with combination of single PI3K or mTOR inhibitors (BKM120 or Rapamycin) and radiation, low-dose of dual PI3K/mTOR inhibitors (BEZ235 or PI103) combined with radiation greatly improved treatment efficacy by repressing colony formation, inducing more apoptosis, leading to the arrest of the G2/M phase, increased double-strand break levels and less inactivation of cell cycle check point, autophagy and non-homologous end joining (NHEJ)/homologous recombination (HR) repair pathway proteins in CaP-radioresistant cells. This study describes the possible pathways associated with CaP radioresistance and demonstrates the putative mechanisms of the radiosensitization effect in CaP-resistant cells in the combination treatment. The findings from this study suggest that the combination of dual PI3K/Akt/mTOR inhibitors (BEZ235 or PI103) with radiotherapy is a promising modality for the treatment of CaP to overcome radioresistance. PMID:25275598

  15. Lipoxygenase inhibitors suppress IL-2 synthesis: relationship with rise of [Ca++]i and the events dependent on protein kinase C activation.

    PubMed

    Dornand, J; Sekkat, C; Mani, J C; Gerber, M

    1987-11-01

    The present study was performed in an attempt to understand the mechanism involved in the inhibition of interleukin 2 (IL-2) synthesis by lipoxygenase (LO) pathway inhibitors. Using the two IL-2-producing lymphoid cell lines, (Jurkat and EL4 cells), we showed first that the inhibitory effect of the phenolic compounds tested (NDGA, BHA and caffeic acid) acted on lymphoid cells themselves and not on eventual monocytic or granulocytic contaminant cells. Secondly, these inhibitors were demonstrated as exerting their effect on two levels: they affected the events controlled by both second messengers implicated in T cell activation, namely rise of intracellular free calcium concentration [( Ca++]i) and protein kinase C (PKC) activation. For this purpose, LO inhibitor effects have been compared: (a) on IL-2 production by the two different lines: Jurkat cells, which need both signals, and EL4 cells, which require only PKC activation for the induction of this production; and (b) on the events induced by the different ways of Jurkat cell activation: PHA (or anti-CD3 monoclonal antibody) versus calcium ionophore. These results are discussed with respect to an eventual involvement of arachidonic acid [AA] derivatives in IL-2 synthesis. PMID:3123378

  16. Dihydroartemisinin as a Putative STAT3 Inhibitor, Suppresses the Growth of Head and Neck Squamous Cell Carcinoma by Targeting Jak2/STAT3 Signaling

    PubMed Central

    Jia, Lifeng; Song, Qi; Zhou, Chenyang; Li, Xiaoming; Pi, Lihong; Ma, Xiuru; Li, Hui; Lu, Xiuying; Shen, Yupeng

    2016-01-01

    Developing drugs that can effectively block STAT3 activation may serve as one of the most promising strategy for cancer treatment. Currently, there is no putative STAT3 inhibitor that can be safely and effectively used in clinic. In the present study, we investigated the potential of dihydroartemisinin (DHA) as a putative STAT3 inhibitor and its antitumor activities in head and neck squamous cell carcinoma (HNSCC). The inhibitory effects of DHA on STAT3 activation along with its underlying mechanisms were studied in HNSCC cells. The antitumor effects of DHA against HNSCC cells were explored both in vitro and in vivo. An investigation on cooperative effects of DHA with cisplatin in killing HNSCC cells was also implemented. DHA exhibited remarkable and specific inhibitory effects on STAT3 activation via selectively blocking Jak2/STAT3 signaling. Besides, DHA significantly inhibited HNSCC growth both in vitro and in vivo possibly through induction of apoptosis and attenuation of cell migration. DHA also synergized with cisplatin in tumor inhibition in HNSCC cells. Our findings demonstrate that DHA is a putative STAT3 inhibitor that may represent a new and effective drug for cancer treatment and therapeutic sensitization in HNSCC patients. PMID:26784960

  17. Dihydroartemisinin as a Putative STAT3 Inhibitor, Suppresses the Growth of Head and Neck Squamous Cell Carcinoma by Targeting Jak2/STAT3 Signaling.

    PubMed

    Jia, Lifeng; Song, Qi; Zhou, Chenyang; Li, Xiaoming; Pi, Lihong; Ma, Xiuru; Li, Hui; Lu, Xiuying; Shen, Yupeng

    2016-01-01

    Developing drugs that can effectively block STAT3 activation may serve as one of the most promising strategy for cancer treatment. Currently, there is no putative STAT3 inhibitor that can be safely and effectively used in clinic. In the present study, we investigated the potential of dihydroartemisinin (DHA) as a putative STAT3 inhibitor and its antitumor activities in head and neck squamous cell carcinoma (HNSCC). The inhibitory effects of DHA on STAT3 activation along with its underlying mechanisms were studied in HNSCC cells. The antitumor effects of DHA against HNSCC cells were explored both in vitro and in vivo. An investigation on cooperative effects of DHA with cisplatin in killing HNSCC cells was also implemented. DHA exhibited remarkable and specific inhibitory effects on STAT3 activation via selectively blocking Jak2/STAT3 signaling. Besides, DHA significantly inhibited HNSCC growth both in vitro and in vivo possibly through induction of apoptosis and attenuation of cell migration. DHA also synergized with cisplatin in tumor inhibition in HNSCC cells. Our findings demonstrate that DHA is a putative STAT3 inhibitor that may represent a new and effective drug for cancer treatment and therapeutic sensitization in HNSCC patients. PMID:26784960

  18. In vivo examination of hydroxyurea and the novel ribonucleotide reductase inhibitors trimidox and didox in combination with the reverse transcriptase inhibitor abacavir: suppression of retrovirus-induced immunodeficiency disease.

    PubMed

    Sumpter, L Ryan; Inayat, Mohammed S; Yost, Erin E; Duvall, William; Hagan, Espen; Mayhew, Christopher N; Elford, Howard L; Gallicchio, Vincent S

    2004-06-01

    Inhibition of ribonucleotide reductase (RR) has gained attention as a potential strategy for HIV-1 therapy through the success of hydroxyurea (HU) to potentiate the activity of the nucleoside reverse transcriptase inhibitor (NRTI) didanosine (ddI) in clinical trials. However, the use of HU has been limited by its development of hematopoietic toxicity. In this study, the novel RR inhibitors didox (DX; 3,4-dihydroxybenzohydroxamic acid), and trimidox (TX; 3,4,5-trihydroxybenzamidoxime) were evaluated along with HU for anti-retroviral efficacy in LPBM5-induced retro-viral disease (MAIDS) both as monotherapeutic regimens and in combination with the guanine containing NRTI abacavir (ABC). Anti-retroviral drug efficacy was determined by measuring inhibition of splenomegaly, hypergammaglobulinemia, and splenic levels of proviral DNA. In this study, all RRIs tested showed the ability to improve the efficacy of ABC in the MAIDS model by reducing splenomegaly, hypergammaglobulinemia, and splenic proviral DNA levels. PMID:15130534

  19. Treatment with a Small Molecule Mutant IDH1 Inhibitor Suppresses Tumorigenic Activity and Decreases Production of the Oncometabolite 2-Hydroxyglutarate in Human Chondrosarcoma Cells.

    PubMed

    Li, Luyuan; Paz, Ana C; Wilky, Breelyn A; Johnson, Britt; Galoian, Karina; Rosenberg, Andrew; Hu, Guozhi; Tinoco, Gabriel; Bodamer, Olaf; Trent, Jonathan C

    2015-01-01

    Chondrosarcomas are malignant bone tumors that produce cartilaginous matrix. Mutations in isocitrate dehydrogenase enzymes (IDH1/2) were recently described in several cancers including chondrosarcomas. The IDH1 inhibitor AGI-5198 abrogates the ability of mutant IDH1 to produce the oncometabolite D-2 hydroxyglutarate (D-2HG) in gliomas. We sought to determine if treatment with AGI-5198 would similarly inhibit tumorigenic activity and D-2HG production in IDH1-mutant human chondrosarcoma cells. Two human chondrosarcoma cell lines, JJ012 and HT1080 with endogenous IDH1 mutations and a human chondrocyte cell line C28 with wild type IDH1 were employed in our study. Mutation analysis of IDH was performed by PCR-based DNA sequencing, and D-2HG was detected using tandem mass spectrometry. We confirmed that JJ012 and HT1080 harbor IDH1 R132G and R132C mutation, respectively, while C28 has no mutation. D-2HG was detectable in cell pellets and media of JJ012 and HT1080 cells, as well as plasma and urine from an IDH-mutant chondrosarcoma patient, which decreased after tumor resection. AGI-5198 treatment decreased D-2HG levels in JJ012 and HT1080 cells in a dose-dependent manner, and dramatically inhibited colony formation and migration, interrupted cell cycling, and induced apoptosis. In conclusion, our study demonstrates anti-tumor activity of a mutant IDH1 inhibitor in human chondrosarcoma cell lines, and suggests that D-2HG is a potential biomarker for IDH mutations in chondrosarcoma cells. Thus, clinical trials of mutant IDH inhibitors are warranted for patients with IDH-mutant chondrosarcomas. PMID:26368816

  20. Treatment with a Small Molecule Mutant IDH1 Inhibitor Suppresses Tumorigenic Activity and Decreases Production of the Oncometabolite 2-Hydroxyglutarate in Human Chondrosarcoma Cells

    PubMed Central

    Li, Luyuan; Paz, Ana C.; Wilky, Breelyn A.; Johnson, Britt; Galoian, Karina; Rosenberg, Andrew; Hu, Guozhi; Tinoco, Gabriel; Bodamer, Olaf; Trent, Jonathan C.

    2015-01-01

    Chondrosarcomas are malignant bone tumors that produce cartilaginous matrix. Mutations in isocitrate dehydrogenase enzymes (IDH1/2) were recently described in several cancers including chondrosarcomas. The IDH1 inhibitor AGI-5198 abrogates the ability of mutant IDH1 to produce the oncometabolite D-2 hydroxyglutarate (D-2HG) in gliomas. We sought to determine if treatment with AGI-5198 would similarly inhibit tumorigenic activity and D-2HG production in IDH1-mutant human chondrosarcoma cells. Two human chondrosarcoma cell lines, JJ012 and HT1080 with endogenous IDH1 mutations and a human chondrocyte cell line C28 with wild type IDH1 were employed in our study. Mutation analysis of IDH was performed by PCR-based DNA sequencing, and D-2HG was detected using tandem mass spectrometry. We confirmed that JJ012 and HT1080 harbor IDH1 R132G and R132C mutation, respectively, while C28 has no mutation. D-2HG was detectable in cell pellets and media of JJ012 and HT1080 cells, as well as plasma and urine from an IDH-mutant chondrosarcoma patient, which decreased after tumor resection. AGI-5198 treatment decreased D-2HG levels in JJ012 and HT1080 cells in a dose-dependent manner, and dramatically inhibited colony formation and migration, interrupted cell cycling, and induced apoptosis. In conclusion, our study demonstrates anti-tumor activity of a mutant IDH1 inhibitor in human chondrosarcoma cell lines, and suggests that D-2HG is a potential biomarker for IDH mutations in chondrosarcoma cells. Thus, clinical trials of mutant IDH inhibitors are warranted for patients with IDH-mutant chondrosarcomas. PMID:26368816

  1. Statins and the squalene synthase inhibitor zaragozic acid stimulate the non-amyloidogenic pathway of amyloid-beta protein precursor processing by suppression of cholesterol synthesis.

    PubMed

    Kojro, Elzbieta; Füger, Petra; Prinzen, Claudia; Kanarek, Anna Maria; Rat, Dorothea; Endres, Kristina; Fahrenholz, Falk; Postina, Rolf

    2010-01-01

    Cholesterol-lowering drugs such as statins influence the proteolytic processing of the amyloid-beta protein precursor (AbetaPP) and are reported to stimulate the activity of alpha-secretase, the major preventive secretase of Alzheimer's disease. Statins can increase the alpha-secretase activity by their cholesterol-lowering properties as well as by impairment of isoprenoids synthesis. In the present study, we elucidate the contribution of these pathways in alpha-secretase activation. We demonstrate that zaragozic acid, a potent inhibitor of squalene synthase which blocks cholesterol synthesis but allows synthesis of isoprenoids, also stimulates alpha-secretase activity. Treatment of human neuroblastoma cells with 50 microM zaragozic acid resulted in a approximately 3 fold increase of alpha-secretase activity and reduced cellular cholesterol by approximately 30%. These effects were comparable to results obtained from cells treated with a low lovastatin concentration (2 microM). Zaragozic acid-stimulated secretion of alpha-secretase-cleaved soluble AbetaPP was dose dependent and saturable. Lovastatin- or zaragozic acid-stimulated increase of alpha-secretase activity was completely abolished by a selective ADAM10 inhibitor. By targeting the alpha-secretase ADAM10 to lipid raft domains via a glycosylphosphatidylinositol anchor, we demonstrate that ADAM10 is unable to cleave AbetaPP in a cholesterol-rich environment. Our results indicate that inhibition of cholesterol biosynthesis by a low lovastatin concentration is sufficient for alpha-secretase activation. PMID:20413873

  2. Oxidative DNA damage induces the ATM-mediated transcriptional suppression of the Wnt inhibitor WIF-1 in systemic sclerosis and fibrosis.

    PubMed

    Svegliati, Silvia; Marrone, Giusi; Pezone, Antonio; Spadoni, Tatiana; Grieco, Antonella; Moroncini, Gianluca; Grieco, Domenico; Vinciguerra, Maria; Agnese, Savina; Jüngel, Astrid; Distler, Oliver; Musti, Anna Maria; Gabrielli, Armando; Avvedimento, Enrico V

    2014-09-01

    Systemic sclerosis (SSc) is an autoimmune disease characterized by extensive visceral organ and skin fibrosis. SSc patients have increased production of autoreactive antibodies and Wnt signaling activity. We found that expression of the gene encoding Wnt inhibitor factor 1 (WIF-1) was decreased in fibroblasts from SSc patient biopsies. WIF-1 deficiency in SSc patient cells correlated with increased abundance of the Wnt effector β-catenin and the production of collagen. Knocking down WIF-1 in normal fibroblasts increased Wnt signaling and collagen production. WIF-1 loss and DNA damage were induced in normal fibroblasts by either SSc patient immunoglobulins or oxidative DNA-damaging agents, such as ultraviolet light, hydrogen peroxide, or bleomycin. The DNA damage checkpoint kinase ataxia telangiectasia mutated (ATM) mediated WIF-1 silencing through the phosphorylation of the transcription factor c-Jun, which in turn activated the expression of the gene encoding activating transcription factor 3 (ATF3). ATF3 and c-Jun were recruited together with histone deacetylase 3 (HDAC3) to the WIF-1 promoter and inhibited WIF-1 expression. Preventing the accumulation of reactive oxygen species or inhibiting the activation of ATM, c-Jun, or HDACs restored WIF-1 expression in cultured SSc patient cells. Trichostatin A, an HDAC inhibitor, prevented WIF-1 loss, β-catenin induction, and collagen accumulation in an experimental fibrosis model. Our findings suggest that oxidative DNA damage induced by SSc autoreactive antibodies enables Wnt activation that contributes to fibrosis. PMID:25185156

  3. Class I HDAC inhibitor mocetinostat induces apoptosis by activation of miR-31 expression and suppression of E2F6

    PubMed Central

    Zhang, Q; Sun, M; Zhou, S; Guo, B

    2016-01-01

    The class I selective inhibitor of the histone deacetylases, mocetinostat, has promising antitumor activities in both preclinical studies and the clinical trials. To understand how mocetinostat induces apoptosis, we examined the effects of mocetinostat on miR-31, a proapoptotic microRNA that was previously found to be epigenetically silenced in prostate cancer. We found that miR-31 was significantly upregulated by mocetinostat in prostate cancer cells. Antiapoptotic protein E2F6, the target of miR-31, was decreased by mocetinostat treatment. When miR-31 was blocked with an inhibitor, the ability of mocetinostat to induce apoptosis was reduced. We further demonstrated that mocetinostat enhanced the activity of docetaxel in apoptosis induction. While siRNA knockdown of E2F6 sensitized cancer cells to mocetinostat-induced apoptosis, overexpression of E2F6 blocked mocetinostat-induced apoptosis. In an orthotopic xenograft model, we demonstrated that mocetinostat activated miR-31, decreased E2F6, induced apoptosis, and significantly reduced prostate cancer growth. Importantly, we found that mocetinostat also increased miR-31 expression, decreased E2F6, and induced apoptosis in the primary prostate cancer stem cells. Thus, activation of miR-31 and downregulation of E2F6 constitute an important mechanism in mocetinostat-induced apoptosis in prostate cancer. PMID:27551526

  4. BI 5700, a Selective Chemical Inhibitor of IκB Kinase 2, Specifically Suppresses Epithelial-Mesenchymal Transition and Metastasis in Mouse Models of Tumor Progression

    PubMed Central

    Huber, Margit A.; Maier, Harald J.; Alacakaptan, Memetcan; Wiedemann, Eva; Braunger, Jürgen; Boehmelt, Guido; Madwed, Jeffrey B.; Young, Erick R.R.; Marshall, Daniel R.; Pehamberger, Hubert; Wirth, Thomas; Kraut, Norbert; Beug, Hartmut

    2010-01-01

    Increasing evidence suggests that processes termed epithelial-mesenchymal transitions (EMTs) play a key role in therapeutic resistance, tumor recurrence, and metastatic progression. NF-κB signaling has been previously identified as an important pathway in the regulation of EMT in a mouse model of tumor progression. However, it remains unclear whether there is a broad requirement for this pathway to govern EMT and what the relative contribution of IKK family members acting as upstream NF-κB activators is toward promoting EMT and metastasis. To address this question, we have used a novel, small-molecule inhibitor of IκB kinase 2 (IKK2/IKKβ), termed BI 5700. We investigated the role of IKK2 in a number of mouse models of EMT, including TGFβ-induced EMT in the mammary epithelial cell line EpRas, CT26 colon carcinoma cells, and 4T1 mammary carcinoma cells. The latter model was also used to evaluate in vivo activities of BI 5700.We found that BI 5700 inhibits IKK2 with an IC50 of 9 nM and was highly selective as compared to other IKK family members (IKK1, IKKε, and TBK1) and other kinases. BI 5700 effectively blocks NF-κB activity in EpRas cells and prevents TGFβ-induced EMT. In addition, BI 5700 reverts EMT in mesenchymal CT26 cells and prevents EMT in the 4T1 model. Oral application of BI 5700 significantly interferes with metastasis after mammary fat-pad injection of 4T1 cells, yielding fewer, smaller, and more differentiated metastases as compared to vehicle-treated control animals. We conclude that IKK2 is a key regulator of both the induction and maintenance of EMT in a panel of mouse tumor progression models and that the IKK2 inhibitor BI 5700 constitutes a promising candidate for the treatment of metastatic cancers. PMID:21779445

  5. Multi-kinase inhibitors can associate with heat shock proteins through their NH2-termini by which they suppress chaperone function.

    PubMed

    Booth, Laurence; Shuch, Brian; Albers, Thomas; Roberts, Jane L; Tavallai, Mehrad; Proniuk, Stefan; Zukiwski, Alexander; Wang, Dasheng; Chen, Ching-Shih; Bottaro, Don; Ecroyd, Heath; Lebedyeva, Iryna O; Dent, Paul

    2016-03-15

    We performed proteomic studies using the GRP78 chaperone-inhibitor drug AR-12 (OSU-03012) as bait. Multiple additional chaperone and chaperone-associated proteins were shown to interact with AR-12, including: GRP75, HSP75, BAG2; HSP27; ULK-1; and thioredoxin. AR-12 down-regulated in situ immuno-fluorescence detection of ATP binding chaperones using antibodies directed against the NH2-termini of the proteins but only weakly reduced detection using antibodies directed against the central and COOH portions of the proteins. Traditional SDS-PAGE and western blotting assessment methods did not exhibit any alterations in chaperone detection. AR-12 altered the sub-cellular distribution of chaperone proteins, abolishing their punctate speckled patterning concomitant with changes in protein co-localization. AR-12 inhibited chaperone ATPase activity, which was enhanced by sildenafil; inhibited chaperone - chaperone and chaperone - client interactions; and docked in silico with the ATPase domains of HSP90 and of HSP70. AR-12 combined with sildenafil in a GRP78 plus HSP27 -dependent fashion to profoundly activate an eIF2α/ATF4/CHOP/Beclin1 pathway in parallel with inactivating mTOR and increasing ATG13 phosphorylation, collectively resulting in formation of punctate toxic autophagosomes. Over-expression of [GRP78 and HSP27] prevented: AR-12 -induced activation of ER stress signaling and maintained mTOR activity; AR-12 -mediated down-regulation of thioredoxin, MCL-1 and c-FLIP-s; and preserved tumor cell viability. Thus the inhibition of chaperone protein functions by AR-12 and by multi-kinase inhibitors very likely explains why these agents have anti-tumor effects in multiple genetically diverse tumor cell types. PMID:26887051

  6. Multi-kinase inhibitors can associate with heat shock proteins through their NH2-termini by which they suppress chaperone function

    PubMed Central

    Roberts, Jane L.; Tavallai, Mehrad; Proniuk, Stefan; Zukiwski, Alexander; Wang, Dasheng; Chen, Ching-Shih; Bottaro, Don; Ecroyd, Heath; Lebedyeva, Iryna O.; Dent, Paul

    2016-01-01

    We performed proteomic studies using the GRP78 chaperone-inhibitor drug AR-12 (OSU-03012) as bait. Multiple additional chaperone and chaperone-associated proteins were shown to interact with AR-12, including: GRP75, HSP75, BAG2; HSP27; ULK-1; and thioredoxin. AR-12 down-regulated in situ immuno-fluorescence detection of ATP binding chaperones using antibodies directed against the NH2-termini of the proteins but only weakly reduced detection using antibodies directed against the central and COOH portions of the proteins. Traditional SDS-PAGE and western blotting assessment methods did not exhibit any alterations in chaperone detection. AR-12 altered the sub-cellular distribution of chaperone proteins, abolishing their punctate speckled patterning concomitant with changes in protein co-localization. AR-12 inhibited chaperone ATPase activity, which was enhanced by sildenafil; inhibited chaperone – chaperone and chaperone – client interactions; and docked in silico with the ATPase domains of HSP90 and of HSP70. AR-12 combined with sildenafil in a GRP78 plus HSP27 –dependent fashion to profoundly activate an eIF2α/ATF4/CHOP/Beclin1 pathway in parallel with inactivating mTOR and increasing ATG13 phosphorylation, collectively resulting in formation of punctate toxic autophagosomes. Over-expression of [GRP78 and HSP27] prevented: AR-12 –induced activation of ER stress signaling and maintained mTOR activity; AR-12 –mediated down-regulation of thioredoxin, MCL-1 and c-FLIP-s; and preserved tumor cell viability. Thus the inhibition of chaperone protein functions by AR-12 and by multi-kinase inhibitors very likely explains why these agents have anti-tumor effects in multiple genetically diverse tumor cell types. PMID:26887051

  7. The selective dopamine uptake inhibitor, D-84, suppresses cocaine self-administration, but does not occasion cocaine-like levels of generalization.

    PubMed

    Batman, Angela M; Dutta, Aloke K; Reith, Maarten E A; Beardsley, Patrick M

    2010-12-01

    A successful replacement pharmacotherapy for treating cocaine dependency would likely reduce cocaine's abuse, support a low abuse liability, overlap cocaine's subjective effects, and have a long duration of action. Inhibitors with varying selectivity at the dopamine transporter (DAT) have approximated these properties. The objective of the present study was to characterize the behavioural effects of an extremely selective DAT inhibitor, (+) trans-4-(2-Benzhydryloxyethyl)-1-(4-fluorobenzyl) piperadin-3-ol (D-84), a 3-hydroxy substituted piperidine derivative of GBR-12935, for its cocaine-like discriminative stimulus effects, its effects on cocaine self-administration, and for its own self-administration. During cocaine discrimination tests, cocaine occasioned the 10 mg/kg cocaine training stimulus with an ED(50) value of 3.13 (1.54-6.34) mg/kg, and reduced response rates with an ED(50) value of 20.39 (7.24-57.44) mg/kg. D-84 incompletely generalized to the cocaine stimulus occasioning a maximal 76% cocaine-lever responding, while reducing response rates with lower potency than cocaine (ED(50)=30.94 (12.34-77.60) mg/kg). Pretreatment with D-84 (9.6-30.4 mg/kg) significantly (P<0.05) reduced cocaine intake at 17.1 mg/kg D-84 when cocaine was self-administered at 0.5 mg/kg/infusion, and at 30.4 mg/kg D-84 when cocaine was self-administered at 0.1, 0.5 .and 1.0 mg/kg/infusion. During self-administration tests with D-84 (0.1-1 mg/kg/infusion), numbers of infusions significantly exceeded vehicle levels at 0.3 mg/kg/infusion. These results show that D-84 pretreatment can decrease cocaine intake especially when high doses of cocaine are being self-administered. This observation, combined with its incomplete generalization to the cocaine discriminative stimulus and its reported long duration of action, provides a profile consistent with a potential replacement therapy for treating cocaine-abusing patients. PMID:20840845

  8. Human immunodeficiency virus integrase inhibitors efficiently suppress feline immunodeficiency virus replication in vitro and provide a rationale to redesign antiretroviral treatment for feline AIDS

    PubMed Central

    Savarino, Andrea; Pistello, Mauro; D'Ostilio, Daniela; Zabogli, Elisa; Taglia, Fabiana; Mancini, Fabiola; Ferro, Stefania; Matteucci, Donatella; De Luca, Laura; Barreca, Maria Letizia; Ciervo, Alessandra; Chimirri, Alba; Ciccozzi, Massimo; Bendinelli, Mauro

    2007-01-01

    Background Treatment of feline immunodeficiency virus (FIV) infection has been hampered by the absence of a specific combination antiretroviral treatment (ART). Integrase strand transfer inhibitors (INSTIs) are emerging as a promising new drug class for HIV-1 treatment, and we evaluated the possibility of inhibiting FIV replication using INSTIs. Methods Phylogenetic analysis of lentiviral integrase (IN) sequences was carried out using the PAUP* software. A theoretical three-dimensional structure of the FIV IN catalytic core domain (CCD) was obtained by homology modeling based on a crystal structure of HIV-1 IN CCD. The interaction of the transferred strand of viral DNA with the catalytic cavity of FIV IN was deduced from a crystal structure of a structurally similar transposase complexed with transposable DNA. Molecular docking simulations were conducted using a genetic algorithm (GOLD). Antiviral activity was tested in feline lymphoblastoid MBM cells acutely infected with the FIV Petaluma strain. Circular and total proviral DNA was quantified by real-time PCR. Results The calculated INSTI-binding sites were found to be nearly identical in FIV and HIV-1 IN CCDs. The close similarity of primate and feline lentivirus IN CCDs was also supported by phylogenetic analysis. In line with these bioinformatic analyses, FIV replication was efficiently inhibited in acutely infected cell cultures by three investigational INSTIs, designed for HIV-1 and belonging to different classes. Of note, the naphthyridine carboxamide INSTI, L-870,810 displayed an EC50 in the low nanomolar range. Inhibition of FIV integration in situ was shown by real-time PCR experiments that revealed accumulation of circular forms of FIV DNA within cells treated with L-870,810. Conclusion We report a drug class (other than nucleosidic reverse transcriptase inhibitors) that is capable of inhibiting FIV replication in vitro. The present study helped establish L-870,810, a compound successfully tested in

  9. Connexin 43-dependent tumor-suppressing effect of the Bowman-Birk protease inhibitor on M5076 ovarian sarcoma-bearing mice.

    PubMed

    Sakurai, Noritaka; Suzuki, Kazuyuki; Nagaoka, Tetsuya; Saito, Teruyoshi; Yoshimura, Hisashi; Yano, Tomohiro; Sadzuka, Yasuyuki; Asano, Ryuji

    2008-01-01

    The present study was designed to confirm whether the Bowman-Birk inhibitor (BBI) induces an increase in p27 accumulation without S phase kinase-associated protein 2 (skp2) degradation by means of the expression of connexin (Cx) 43 as a gap junctional intercellular communication (GJIC)-dependent pathway in mice with M5076 ovarian sarcoma. M5076 ovarian sarcomas (1x105 cells/animal) were subcutaneously transplanted onto the backs of BDF1 mice receiving 10, 20 or 40 mg/kg of purified BBI intraperitoneally. Relative tumor weight (p<0.01, r=0.503) was negatively correlated with the dose of BBI. In contrast, the relative density of Cx43 mRNA (p<0.01, r=0.570) and Cx43 (p<0.01, r=0.718) was positively correlated with the dose of BBI, as were p21 (p<0.01, r=0.633), p27 (p<0.01, r=0.561) and skp2 (p<0.01, r=0.733). We therefore suggest that the anti-carcinogenic effects of BBI induce negative growth control by means of an increase in p27 accumulation caused by the expression of Cx43 as a GJIC pathway. PMID:21479471

  10. Ochratoxin A inhibits the production of tissue factor and plasminogen activator inhibitor-2 by human blood mononuclear cells: Another potential mechanism of immune-suppression

    SciTech Connect

    Rossiello, Maria R.; Rotunno, Crescenzia; Coluccia, Addolorata; Carratu, Maria R.; Di Santo, Angelomaria; Evangelista, Virgilio; Semeraro, Nicola; Colucci, Mario

    2008-06-01

    The mycotoxin ochratoxin A (OTA), an ubiquitous contaminant of food products endowed with a wide spectrum of toxicity, affects several functions of mononuclear leukocytes. Monocytes/macrophages play a major role in fibrin accumulation associated with immune-inflammatory processes through the production of tissue factor (TF) and plasminogen activator inhibitor 2 (PAI-2). We studied the effect of OTA on TF and PAI-2 production by human blood mononuclear cells (MNC). The cells were incubated for 3 or 18 h at 37 deg. C with non toxic OTA concentrations in the absence and in the presence of lipopolysaccharide (LPS) or other inflammatory agents. TF activity was measured by a one-stage clotting test. Antigen assays were performed by specific ELISAs in cell extracts or conditioned media and specific mRNAs were assessed by RT-PCR. OTA had no direct effect on TF and PAI-2 production by MNC. However, OTA caused a dose-dependent reduction in LPS-induced TF (activity, antigen and mRNA) and PAI-2 (antigen and mRNA) production with > 85% inhibition at 1 {mu}g/ml. Similar results were obtained when monocyte-enriched preparations were used instead of MNC. TF production was also impaired by OTA (1 {mu}g/ml) when MNC were stimulated with phorbol myristate acetate (98% inhibition), IL-1{beta} (83%) or TNF-{alpha} (62%). The inhibition of TF and PAI-2 induction might represent a hitherto unrecognized mechanism whereby OTA exerts immunosuppressant activity.

  11. The novel mTORC1/2 dual inhibitor INK-128 suppresses survival and proliferation of primary and transformed human pancreatic cancer cells.

    PubMed

    Lou, Hai-Zhou; Weng, Xiao-Chuan; Pan, Hong-Ming; Pan, Qin; Sun, Peng; Liu, Li-Li; Chen, Bin

    2014-07-25

    Pancreatic cancer has one of worst prognosis among all human malignancies around the world, the development of novel and more efficient anti-cancer agents against this disease is urgent. In the current study, we tested the potential effect of INK-128, a novel mammalian target of rapamycin (mTOR) complex 1 and 2 (mTORC1/2) dual inhibitor, against pancreatic cancer cells in vitro. Our results demonstrated that INK-128 concentration- and time-dependently inhibited the survival and growth of pancreatic cancer cells (both primary cells and transformed cells). INK-128 induced pancreatic cancer cell apoptosis and necrosis simultaneously. Further, INK-128 dramatically inhibited phosphorylation of 4E-binding protein 1 (4E-BP1), ribosomal S6 kinase 1 (S6K1) and Akt at Ser 473 in pancreatic cancer cells. Meanwhile, it downregulated cyclin D1 expression and caused cell cycle arrest. Finally, we found that a low concentration of INK-128 significantly increased the sensitivity of pancreatic cancer cells to gemcitabine. Together, our in vitro results suggest that INK-128 might be further investigated as a novel anti-cancer agent or chemo-adjuvant for pancreatic cancer treatment. PMID:24971544

  12. A peptide derived from the parasite receptor, complement C2 receptor inhibitor trispanning, suppresses immune complex-mediated inflammation in mice.

    PubMed

    Inal, Jameel M; Schneider, Brigitte; Armanini, Marta; Schifferli, Jürg A

    2003-04-15

    Complement C2 receptor inhibitor trispanning (CRIT) is a Schistosoma protein that binds the human complement protein, C2. We recently showed that peptides based on the ligand binding region of CRIT inhibit the classical pathway (CP) of complement activation in human serum, using hemolytic assays and so speculated that on the parasite surface CRIT has the function of evading human complement. We now show that in vitro the C2-binding 11-aa C terminus of the first extracellular domain of CRIT, a 1.3-kDa peptide termed CRIT-H17, inhibits CP activation in a species-specific manner, inhibiting mouse and rat complement but not that from guinea pig. Hitherto, the ability of CRIT to regulate complement in vivo has not been assessed. In this study we show that by inhibiting the CP, CRIT-H17 is able to reduce immune complex-mediated inflammation (dermal reversed passive Arthus reaction) in BALB/c mice. Upon intradermal injection of CRIT-H17, and similarly with recombinant soluble complement receptor type 1, there was a 41% reduction in edema and hemorrhage, a 72% reduction in neutrophil influx, and a reduced C3 deposition. Furthermore, when H17 was administered i.v. at a 1 mg/kg dose, inflammation was reduced by 31%. We propose that CRIT-H17 is a potential therapeutic agent against CP complement-mediated inflammatory tissue destruction. PMID:12682267

  13. Chidamide, a novel histone deacetylase inhibitor, inhibits the viability of MDS and AML cells by suppressing JAK2/STAT3 signaling

    PubMed Central

    Zhao, Sida; Guo, Juan; Zhao, Youshan; Fei, Chengming; Zheng, Qingqing; Li, Xiao; Chang, Chunkang

    2016-01-01

    Many studies have indicated that histone deacetylase (HDAC) activity is always increased in a lot of human tumors, and inhibition of HDAC activity is a promising new strategy in the treatment of cancers. Chidamide, a novel HDAC inhibitor of the benzamide class, is currently under clinical trials. In this study, we aimed to investigate the antitumor activity of Chidamide on myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) cell lines and explore the possible mechanism. Chidamide exhibited efficient anti-proliferative activity on MDS and AML cells in a time- and dose-dependent manner, accompanied by cell cycle arrest at G0/G1 phase and cell apoptosis. Importantly, Chidamide possessed potent HDAC inhibition property, as evaluated by HDAC activity analysis and acetylation of histone H3 and H4. Moreover, Chidamide significantly increased the expression of Suppressors of cytokine signaling 3 (SOCS3), reduced the expression of Janus activated kinases 2 (JAK2) and Signal transducer and activator of transcription 3 (STAT3), and inhibited STAT3 downstream genes, including c-Myc, Bcl-xL, and Mcl-1, which are involved in cell cycle progression and anti-apoptosis. Therefore, we demonstrate that Chidamide exhibits potent inhibitory effect on cell viability of MDS and AML cells, and the possible mechanism may lie in the downregulation of JAK2/STAT3 signaling through SOCS3 upregulation. Our data provide rationale for clinical investigations of Chidamide in MDS and AML. PMID:27508038

  14. Plantar injection of formalin in rats reduces the expression of a potassium chroride cotransporter KCC2 in the spinal cord and a kinase inhibitor suppresses this reduction.

    PubMed

    Tsuruga, Kenkichi; Hashimoto, Toshikazu; Kato, Ryoko; Kato, Rui; Uchida, Yousuke; Hase, Tetsutaro; Morimoto, Yuji

    2016-01-01

    Brain-derived neurotrophic factor (BDNF) is released from activated microglia during neuropathic pain and is hypothesized to downregulate the expression of the potassium chloride cotransporter 2 (KCC2) via the TrkB receptor. Previous studies reported that KCC2 is downregulated 5 min after the plantar injection of formalin in rats; however, the mechanism behind this decrease in KCC2 expression during acute inflammatory pain remains unknown. In this study, we determined whether the TrkB receptor contributes to the expression of KCC2 during the acute pain. Five minutes after the plantar injection of formalin in rats, the ratio of KCC2-immunoreactive area in layer II of the spinal cord significantly decreased on the stimulated side compared to the unaffected side. On the other hand, this response was inhibited by the injection of a kinase inhibitor, K252a, in the subarachnoid space 15 min before the formalin injection. These findings suggest that in acute pain, the TrkB receptor may contribute to the decrease in the expression of KCC2. PMID:27545000

  15. Suppression of Human T Cell Proliferation Mediated by the Cathepsin B Inhibitor, z-FA-FMK Is Due to Oxidative Stress

    PubMed Central

    Rajah, Tanuja; Chow, Sek Chuen

    2015-01-01

    The cathepsin B inhibitor, benzyloxycarbonyl-phenylalanine-alanine-fluoromethyl ketone (z-FA-FMK) readily inhibits anti-CD3-induced human T cell proliferation, whereas the analogue benzyloxycarbonyl-phenylalanine-alanine-diazomethyl ketone (z-FA-DMK) had no effect. In contrast, benzyloxycarbonyl-phenylalanine-alanine-chloromethyl ketone (z-FA-CMK) was toxic. The inhibition of T cell proliferation mediated by z-FA-FMK requires not only the FMK moiety, but also the benzyloxycarbonyl group at the N-terminal, suggesting some degree of specificity in z-FA-FMK-induced inhibition of primary T cell proliferation. We showed that z-FA-FMK treatment leads to a decrease in intracellular glutathione (GSH) with a concomitant increase in reactive oxygen species (ROS) levels in activated T cells. The inhibition of anti-CD3-induced T cell proliferation mediated by z-FA-FMK was abolished by the presence of low molecular weight thiols such as GSH, N-acetylcysteine (NAC) and L-cysteine, whereas D-cysteine which cannot be metabolised to GSH has no effect. The inhibition of anti-CD3-induced up-regulation of CD25 and CD69 expression mediated by z-FA-FMK was also attenuated in the presence of exogenous GSH. Similar to cell proliferation, GSH, NAC and L-cysteine but not D-cysteine, completely restored the processing of caspase-8 and caspase-3 to their respective subunits in z-FA-FMK-treated activated T cells. Our collective results demonstrated that the inhibition of T cell activation and proliferation mediated by z-FA-FMK is due to oxidative stress via the depletion of GSH. PMID:25915766

  16. Sphingosine kinase inhibitor suppresses IL-18-induced interferon-gamma production through inhibition of p38 MAPK activation in human NK cells

    SciTech Connect

    Cheon, Soyoung; Song, Seok Bean; Jung, Minkyung; Park, Yoorim; Bang, Jung-Wook; Kim, Tae Sung; Park, Hyunjeong; Kim, Cherl-hyun; Yang, Yool-hee; Bang, Sa Ik; Cho, Daeho

    2008-09-12

    Natural killer (NK) cells play an important role in the innate immune response. Interleukin-18 (IL-18) is a well-known interferon-gamma (IFN-{gamma} inducing factor, which stimulates immune response in NK and T cells. Sphingosine kinase (SPHK) catalyzes the formation of sphingosine 1-phosphate (S1P), which acts as a second messenger to function as an anti-apoptotic factor and proliferation stimulator of immune cells. In this study, to elucidate whether SPHK is involved in IL-18-induced IFN-{gamma} production, we measured IL-18-induced IFN-{gamma} production after pre-treatment with SPHK inhibitor (SKI) in NK-92MI cells. We found that IL-18-induced IFN-{gamma} expression was blocked by SKI pre-treatment in both mRNA and protein levels. In addition, the increased IFN-{gamma} production by stimulation with IL-18 is mediated through both SPHK and p38 MAPK. To determine the upstream signals of SKI and p38 MAPK in IL-18-induced IFN-{gamma} production, phosphorylation levels of p38 MAPK was measured after SKI pre-treatment. As a result, inhibition of SPHK by SKI blocked phosphorylation of p38 MAPK, showing that SPHK activation by IL-18 is an upstream signal of p38 MAPK activation. Inhibition of SPHK by SKI also inhibited IL-18-induced IFN-{gamma} production in human primary NK cells. In conclusion, SPHK activation is an essential factor for IL-18-induced IFN-{gamma} production via p38 MAPK.

  17. The novel JAK inhibitor AZD1480 blocks STAT3 and FGFR3 signaling, resulting in suppression of human myeloma cell growth and survival.

    PubMed

    Scuto, A; Krejci, P; Popplewell, L; Wu, J; Wang, Y; Kujawski, M; Kowolik, C; Xin, H; Chen, L; Wang, Y; Kretzner, L; Yu, H; Wilcox, W R; Yen, Y; Forman, S; Jove, R

    2011-03-01

    IL-6 and downstream JAK-dependent signaling pathways have critical roles in the pathophysiology of multiple myeloma (MM). We investigated the effects of a novel small-molecule JAK inhibitor (AZD1480) on IL-6/JAK signal transduction and its biological consequences on the human myeloma-derived cell lines U266 and Kms.11. At low micromolar concentrations, AZD1480 blocks cell proliferation and induces apoptosis of myeloma cell lines. These biological responses to AZD1480 are associated with concomitant inhibition of phosphorylation of JAK2, STAT3 and MAPK signaling proteins. In addition, there is inhibition of expression of STAT3 target genes, particularly Cyclin D2. Examination of a wider variety of myeloma cells (RPMI 8226, OPM-2, NCI-H929, Kms.18, MM1.S and IM-9), as well as primary myeloma cells, showed that AZD1480 has broad efficacy. In contrast, viability of normal peripheral blood (PB) mononuclear cells and CD138(+) cells derived from healthy controls was not significantly inhibited. Importantly, AZD1480 induces cell death of Kms.11 cells grown in the presence of HS-5 bone marrow (BM)-derived stromal cells and inhibits tumor growth in a Kms.11 xenograft mouse model, accompanied with inhibition of phospho-FGFR3, phospho-JAK2, phospho-STAT3 and Cyclin D2 levels. In sum, AZD1480 blocks proliferation, survival, FGFR3 and JAK/STAT3 signaling in myeloma cells cultured alone or cocultured with BM stromal cells, and in vivo. Thus, AZD1480 represents a potential new therapeutic agent for patients with MM. PMID:21164517

  18. Treatment with the PI3K inhibitor buparlisib (NVP-BKM120) suppresses the growth of established patient-derived GBM xenografts and prolongs survival in nude rats.

    PubMed

    Netland, I A; Førde, H E; Sleire, L; Leiss, L; Rahman, M A; Skeie, B S; Miletic, H; Enger, P Ø; Goplen, D

    2016-08-01

    Glioblastomas (GBMs) are aggressive brain tumours with a dismal prognosis, despite combined surgery, radio- and chemotherapy. Close to 90 % of all GBMs harbour a deregulated PI3K pathway, which is essential in regulating central cellular functions such as proliferation, cell growth, motility and survival. Thus, PI3K represents a potential target for molecular therapy in GBM. We investigated the anti-tumour efficacy of the PI3K inhibitor buparlisib (NVP-BKM120) in GBM cell lines in vitro and in vivo, when treatment was initiated after MRI-confirmed tumour engraftment. We found that buparlisib inhibited glioma cell proliferation in a dose dependent manner, demonstrated by MTS assay, manual cell count and BrdU incorporation. A dose dependent increase in apoptosis was observed through flow cytometric analysis. Furthermore, by immunocytochemistry and western blot, we found a dose dependent inhibition of Akt phosphorylation. Moreover, buparlisib prolonged survival of nude rats harboring human GBM xenografts in three independent studies and reduced the tumours' volumetric increase, as determined by MRI. In addition, histological analyses of xenograft rat brains showed necrotic areas and change in tumour cell nuclei in buparlisib-treated animals. The rats receiving buparlisib maintained their weight, activity level and food- and water intake. In conclusion, buparlisib effectively inhibits glioma cell proliferation in vitro and growth of human GBM xenografts in nude rats. Moreover, the compound is well tolerated when administered at doses providing anti-tumour efficacy. Thus, buparlisib may have a future role in glioma therapy, and further studies are warranted to validate this compound for human use. PMID:27283525

  19. B5, a thioredoxin reductase inhibitor, induces apoptosis in human cervical cancer cells by suppressing the thioredoxin system, disrupting mitochondrion-dependent pathways and triggering autophagy

    PubMed Central

    Ma, Dong-Lei; Chen, Wen-Bo; Fu, Wu-Yu; Ruan, Bi-Bo; Rui, Wen; Zhang, Jia-Xuan; Wang, Sheng; Wong, Nai Sum; Xiao, Hao; Li, Man-Mei; Liu, Xiao; Liu, Qiu-Ying; Zhou, Xiao-dong; Yan, Hai-Zhao; Wang, Yi-Fei; Chen, Chang-Yan; Liu, Zhong; Chen, Hong-Yuan

    2015-01-01

    The synthetic curcumin analog B5 is a potent inhibitor of thioredoxin reductase (TrxR) that has potential anticancer effects. The molecular mechanism underlying B5 as an anticancer agent is not yet fully understood. In this study, we report that B5 induces apoptosis in two human cervical cancer cell lines, CaSki and SiHa, as evidenced by the downregulation of XIAP, activation of caspases and cleavage of PARP. The involvement of the mitochondrial pathway in B5-induced apoptosis was suggested by the dissipation of mitochondrial membrane potential and increased expression of pro-apoptotic Bcl-2 family proteins. In B5-treated cells, TrxR activity was markedly inhibited with concomitant accumulation of oxidized thioredoxin, increased formation of reactive oxygen species (ROS), and activation of ASK1 and its downstream regulatory target p38/JNK. B5-induced apoptosis was significantly inhibited in the presence of N-acetyl-l-cysteine. Microscopic examination of B5-treated cells revealed increased presence of cytoplasmic vacuoles. The ability of B5 to activate autophagy in cells was subsequently confirmed by cell staining with acridine orange, accumulation of LC3-II, and measurement of autophagic flux. Unlike B5-induced apoptosis, autophagy induced by B5 is not ROS-mediated but a role for the AKT and AMPK signaling pathways is implied. In SiHa cells but not CaSki cells, B5-induced apoptosis was promoted by autophagy. These data suggest that the anticarcinogenic effects of B5 is mediated by complex interplay between cellular mechanisms governing redox homeostasis, apoptosis and autophagy. PMID:26439985

  20. The novel JAK inhibitor AZD1480 blocks STAT3 and FGFR3 signaling, resulting in suppression of human myeloma cell growth and survival

    PubMed Central

    Scuto, Anna; Krejci, Pavel; Popplewell, Leslie; Wu, Jun; Wang, Yan; Kujawski, Maciej; Kowolik, Claudia; Xin, Hong; Chen, Linling; Wang, Yafan; Kretzner, Leo; Yu, Hua; Wilcox, William R.; Yen, Yun; Forman, Stephen; Jove, Richard

    2011-01-01

    IL-6 and downstream JAK-dependent signaling pathways have critical roles in the pathophysiology of multiple myeloma. We investigated the effects of a novel small-molecule JAK inhibitor (AZD1480) on IL-6/JAK signal transduction and its biological consequences on the human myeloma-derived cell lines U266 and Kms.11. At low micromolar concentrations, AZD1480 blocks cell proliferation and induces apoptosis of myeloma cell lines. These biological responses to AZD1480 are associated with concomitant inhibition of phosphorylation of JAK2, STAT3 and MAPK signaling proteins. In addition, there is inhibition of expression of STAT3 target genes, particularly Cyclin D2. Examination of a wider variety of myeloma cells (RPMI 8226, OPM-2, NCI-H929, Kms.18, MM1.S, IM-9) as well as primary myeloma cells showed that AZD1480 has broad efficacy. By contrast, viability of normal PBMCs and CD138+ cells derived from healthy controls was not significantly inhibited. Importantly, AZD1480 induces cell death of Kms.11 cells grown in the presence of HS-5 bone marrow-derived stromal cells and inhibits tumor growth in a Kms.11 xenograft mouse model, accompanied with inhibition of phospho-FGFR3, phospho-JAK2, phospho-STAT3 and Cyclin D2 levels. In sum, AZD1480 blocks proliferation, survival, FGFR3 and JAK/STAT3 signaling in myeloma cells cultured alone or co-cultured with bone marrow stromal cells and in vivo. Thus, AZD1480 represents a potential new therapeutic agent for patients with multiple myeloma. PMID:21164517

  1. The Novel Small Molecule Inhibitor, OSU-T315, Suppresses Vestibular Schwannoma and Meningioma Growth by Inhibiting PDK2 Function in the AKT Pathway Activation

    PubMed Central

    Mercado-Pimentel, ME; Igarashi, S; Dunn, AM; Behbahani, M; Miller, C; Read, CM; Jacob, A

    2016-01-01

    Activation of PKB/AKT signaling, which requires PDK1 and PDK2 function, drives Vestibular Schwannoma (VS) and meningioma growth. PDK2 function is defined as a molecule that phosphorylates AKT-Ser473. Integrin-Linked Kinase (ILK) functions as PDK2 in PKB/AKT activation in many cancers; therefore, we hypothesized that OSU-T315, a small molecule ILK inhibitor, will inhibit the ILK-PDK2 function in PKB/AKT signaling activation in VS and meningioma cell growth. OSU-T315 decreased cell viability at IC50 < 2μM in VS (HEI193) and meningioma (Ben-Men-1) cell lines, in primary cells at < 3.5μM, while in normal primary Schwann cells at 7.1μM. OSU-T315 inhibits AKT signaling by decreasing phosphorylation at AKT-Ser473, AKT-Thr308, ILK-Ser246 and ILK-Thr173. In addition, OSU-T315 affected the phosphorylation or expression levels of AKT downstream proliferation effectors as well as autophagy markers. Flow cytometry shows that OSU-T315 increased the percentage of cells arrested at G2/M for both, HEI193 (39.99%) and Ben-Men-1 (26.96%) cells, compared to controls (21.54%, 8.47%). Two hours of OSU-T315 treatment increased cell death in both cell lines (34.3%, 9.1%) versus untreated (12.1%, 8.1%). Though longer exposure increased cell death in Ben-Men-1, TUNEL assays showed that OSU-T315 does not induce apoptosis. OSU-T315 was primarily cytotoxic for HEI193 and Ben-Men-1 inducing a dysregulated autophagy. Our studies suggest that OSU-T315 has translational potential as a chemotherapeutic agent against VS and meningioma.

  2. MLN4924, a novel protein neddylation inhibitor, suppresses proliferation and migration of human urothelial carcinoma: In vitro and in vivo studies.

    PubMed

    Kuo, Kuan Lin; Ho, I Lin; Shi, Chung Sheng; Wu, June Tai; Lin, Wei Chou; Tsai, Yu Chieh; Chang, Hong Chiang; Chou, Chien Tso; Hsu, Chen Hsun; Hsieh, Ju Ton; Chang, Shih Chen; Pu, Yeong Shiau; Huang, Kuo How

    2015-07-28

    MLN4924, a small molecule inhibitor of NEDD8 activating enzyme (NAE), has been reported to elicit an anti-tumor effect on various malignancies. In this study, we investigated the anti-tumor effect of MLN4924 in human urothelial carcinoma (UC) in vitro and in vivo by using three human UC cell lines of various grading (T24, NTUB1 and RT4). The impact of MLN4924 on UC cells was determined by measuring viability (MTT), proliferation (BrdU incorporation), cell cycle progression (flow cytometry with propidium iodide staining) and apoptosis (flow cytometry with annexin V-FITC labeling). The cell cycle regulatory molecules, apoptosis-related molecules, and cell stress-related proteins were examined by Western blotting. The influence of tumor cell migration and invasion was analyzed by Transwell and wound healing assays. We also evaluated the effects of MLN4924 on tumor growth by a SCID xenograft mouse model. The data show that MLN4924 induced dose-dependent cytotoxicity, anti-proliferation, anti-migration, anti-invasion and apoptosis in human UC cells, accompanied by activations of Bad, phospho-histone H2A.X, caspase-3, 7 and PARP, decreased level of phospho-Bcl2, and caused cell cycle retardation at the G2M phase. Moreover, MLN4924 activated endoplasmic reticulum stress-related molecules (caspase-4, phospho-eIF2α, ATF-4 and CHOP) and other stress responses (JNK and c-Jun activations). Finally, we confirmed MLN4924 inhibited tumor growth in a UC xenograft mouse model with minimal general toxicity. We concluded that MLN4924 induces apoptosis and cell cycle arrest, as well as activation of cell stress responses in human UC. These findings imply MLN4924 provides a novel strategy for the treatment of UC. PMID:25615422

  3. B5, a thioredoxin reductase inhibitor, induces apoptosis in human cervical cancer cells by suppressing the thioredoxin system, disrupting mitochondrion-dependent pathways and triggering autophagy.

    PubMed

    Shao, Fang-Yuan; Du, Zhi-Yun; Ma, Dong-Lei; Chen, Wen-Bo; Fu, Wu-Yu; Ruan, Bi-Bo; Rui, Wen; Zhang, Jia-Xuan; Wang, Sheng; Wong, Nai Sum; Xiao, Hao; Li, Man-Mei; Liu, Xiao; Liu, Qiu-Ying; Zhou, Xiao-Dong; Yan, Hai-Zhao; Wang, Yi-Fei; Chen, Chang-Yan; Liu, Zhong; Chen, Hong-Yuan

    2015-10-13

    The synthetic curcumin analog B5 is a potent inhibitor of thioredoxin reductase (TrxR) that has potential anticancer effects. The molecular mechanism underlying B5 as an anticancer agent is not yet fully understood. In this study, we report that B5 induces apoptosis in two human cervical cancer cell lines, CaSki and SiHa, as evidenced by the downregulation of XIAP, activation of caspases and cleavage of PARP. The involvement of the mitochondrial pathway in B5-induced apoptosis was suggested by the dissipation of mitochondrial membrane potential and increased expression of pro-apoptotic Bcl-2 family proteins. In B5-treated cells, TrxR activity was markedly inhibited with concomitant accumulation of oxidized thioredoxin, increased formation of reactive oxygen species (ROS), and activation of ASK1 and its downstream regulatory target p38/JNK. B5-induced apoptosis was significantly inhibited in the presence of N-acetyl-l-cysteine. Microscopic examination of B5-treated cells revealed increased presence of cytoplasmic vacuoles. The ability of B5 to activate autophagy in cells was subsequently confirmed by cell staining with acridine orange, accumulation of LC3-II, and measurement of autophagic flux. Unlike B5-induced apoptosis, autophagy induced by B5 is not ROS-mediated but a role for the AKT and AMPK signaling pathways is implied. In SiHa cells but not CaSki cells, B5-induced apoptosis was promoted by autophagy. These data suggest that the anticarcinogenic effects of B5 is mediated by complex interplay between cellular mechanisms governing redox homeostasis, apoptosis and autophagy. PMID:26439985

  4. The novel mTORC1/2 dual inhibitor INK-128 suppresses survival and proliferation of primary and transformed human pancreatic cancer cells

    SciTech Connect

    Lou, Hai-zhou; Weng, Xiao-chuan; Pan, Hong-ming; Pan, Qin; Sun, Peng; Liu, Li-li; Chen, Bin

    2014-07-25

    Highlights: • INK-128 inhibits the survival and growth of human pancreatic cancer cells. • INK-128 induced pancreatic cancer cell apoptosis and necrosis simultaneously. • INK-128 blocks mTORC1/2 activation simultaneously in pancreatic cancer cells. • INK-128 down-regulates cyclin D1 and causes pancreatic cancer cell cycle arrest. • INK-128 significantly increases sensitivity of pancreatic cancer cells to gemcitabine. - Abstract: Pancreatic cancer has one of worst prognosis among all human malignancies around the world, the development of novel and more efficient anti-cancer agents against this disease is urgent. In the current study, we tested the potential effect of INK-128, a novel mammalian target of rapamycin (mTOR) complex 1 and 2 (mTORC1/2) dual inhibitor, against pancreatic cancer cells in vitro. Our results demonstrated that INK-128 concentration- and time-dependently inhibited the survival and growth of pancreatic cancer cells (both primary cells and transformed cells). INK-128 induced pancreatic cancer cell apoptosis and necrosis simultaneously. Further, INK-128 dramatically inhibited phosphorylation of 4E-binding protein 1 (4E-BP1), ribosomal S6 kinase 1 (S6K1) and Akt at Ser 473 in pancreatic cancer cells. Meanwhile, it downregulated cyclin D1 expression and caused cell cycle arrest. Finally, we found that a low concentration of INK-128 significantly increased the sensitivity of pancreatic cancer cells to gemcitabine. Together, our in vitro results suggest that INK-128 might be further investigated as a novel anti-cancer agent or chemo-adjuvant for pancreatic cancer treatment.

  5. Down-regulation of the PTTG1 proto-oncogene contributes to the melanoma suppressive effects of the cyclin-dependent kinase inhibitor PHA-848125.

    PubMed

    Caporali, Simona; Alvino, Ester; Levati, Lauretta; Esposito, Alessia I; Ciomei, Marina; Brasca, Maria G; Del Bufalo, Donatella; Desideri, Marianna; Bonmassar, Enzo; Pfeffer, Ulrich; D'Atri, Stefania

    2012-09-01

    We previously demonstrated that PHA-848125, a cyclin-dependent kinase inhibitor presently under Phase II clinical investigation, impairs melanoma cell growth. In this study, gene expression profiling showed that PHA-848125 significantly modulated the expression of 128 genes, predominantly involved in cell cycle control, in the highly drug-sensitive GL-Mel (p53 wild-type) melanoma cells. Up-regulation of 4 selected genes (PDCD4, SESN2, DDIT4, DEPDC6), and down-regulation of 6 selected genes (PTTG1, CDC25A, AURKA, AURKB, PLK1, BIRC5) was confirmed at protein levels. The same protein analysis performed in PHA-848125-treated M10 melanoma cells - p53 mutated and less sensitive to the drug than GL-Mel cells - revealed no DEPDC6 expression and no changes of PTTG1, PDCD4 and BIRC5 levels. Upon PHA-848125 treatment, a marked PTTG1 down-modulation was also observed in A375 cells (p53 wild-type) but not in CN-Mel cells (p53 mutated). PTTG1 silencing significantly inhibited melanoma cell proliferation and induced senescence, with effects less pronounced in p53 mutated cells. PTTG1 silencing increased PHA-848125 sensitivity of p53 mutated cells but not that of A375 or GL-Mel cells. Accordingly, in M10 but not in A375 cells a higher level of senescence was detected in PHA-848125-treated/PTTG1-silenced cells with respect to PHA-848125-treated controls. In A375 and GL-Mel cells, TP53 silencing attenuated PHA-848125-induced down-modulation of PTTG1 and decreased cell sensitivity to the drug. These findings indicate that PHA-848125-induced down-regulation of PTTG1 depends, at least in part, on p53 function and contributes to the antiproliferative activity of the drug. Our study provides further molecular insight into the antitumor mechanism of PHA-848125. PMID:22704958

  6. A third-generation matrix metalloproteinase (MMP) inhibitor (ONO-4817) combined with docetaxel suppresses progression of lung micrometastasis of MMP-expressing tumor cells in nude mice.

    PubMed

    Yamamoto, Akihiko; Yano, Seiji; Shiraga, Minoru; Ogawa, Hirohisa; Goto, Hisatsugu; Miki, Toyokazu; Zhang, Helong; Sone, Saburo

    2003-03-01

    The lung is the common target organ of hematogenous metastasis that restricts the prognosis of cancer patients. MMPs play a pivotal role in metastasis by promoting tumor invasion and angiogenesis; therefore, a large number of MMPIs have been developed. Our purpose was to determine the therapeutic efficacy of a selective-spectrum MMPI, ONO-4817 (inhibits MMP-2 and MMP-9 but not MMP-1), against established lung micrometastasis in combination with a cytotoxic anticancer drug, DOC, in a nude mouse model. Human non-small cell lung cancer PC14PE6 (adenocarcinoma) or H226 (squamous cell carcinoma) cells, expressing MMP-2, MMP-9 and/or MMP-1, were injected i.v. into nude mice on day 0. Mice received a single injection of DOC on day 7 (after establishment of micrometastasis) and/or ONO-4817 mixed with food from day 7 to the end of experiments. Monotherapy with ONO-4817 or DOC inhibited formation of lung metastasis by PC14PE6 and H226 cells. In addition, combined use of ONO-4817 with DOC significantly suppressed the tumor burden of H226 and PC14PE6 cells in the lung and prolonged the survival of PC14PE6-bearing mice compared to ONO-4817 or DOC alone. These therapies did not affect the body weight or food intake of tumor-bearing mice. FIZ revealed that lung lesions, but not nontumor parenchyma of the lung, expressed gelatinolytic activity and that treatment with ONO-4817 abrogated the gelatinolytic activity in lung lesions. These results suggest that the combined use of MMPIs with cytotoxic anticancer drugs may be helpful in the control of established lung micrometastasis by tumor cells expressing MMPs. PMID:12516105

  7. The Daidzein Metabolite, 6,7,4'-Trihydroxyisoflavone, Is a Novel Inhibitor of PKCα in Suppressing Solar UV-Induced Matrix Metalloproteinase 1

    PubMed Central

    Lim, Tae-Gyu; Kim, Jong-Eun; Lee, Sung-Young; Park, Jun Seong; Yeom, Myung Hun; Chen, Hanyong; Bode, Ann M.; Dong, Zigang; Lee, Ki Won

    2014-01-01

    Soy isoflavone is an attractive source of functional cosmetic materials with anti-wrinkle, whitening and skin hydration effects. After consumption, the majority of soy isoflavones are converted to their metabolites in the human gastrointestinal tract. To understand the physiological impact of soy isoflavone on the human body, it is necessary to evaluate and address the biological function of its metabolites. In this study, we investigated the effect of 6,7,4'-trihydroxyisoflavone (6,7,4'-THIF), a major metabolite of daidzein, against solar UV (sUV)-induced matrix metalloproteinases (MMPs) in normal human dermal fibroblasts. MMPs play a critical role in the degradation of collagen in skin, thereby accelerating the aging process of skin. The mitogen-activated protein/extracellular signal-regulated kinase (MEK)/extracellular signal-regulated kinase (ERK), mitogen-activated protein kinase (MKK)3/6/p38 and MKK4/c-Jun N-terminal kinases (JNK) signaling pathways are known to modulate MMP-1 function, and their activation by sUV was significantly reduced by 6,7,4'-THIF pretreatment. Our results also indicated that the enzyme activity of protein kinase C (PKC)α, an upstream regulator of MKKs signaling, is suppressed by 6,7,4'-THIF using the in vitro kinase assay. Furthermore, the direct interaction between 6,7,4'-THIF and endogenous PKCα was confirmed using the pull-down assay. Not only sUV-induced MMP-1 expression, but also sUV-induced signaling pathway activation were decreased in PKCα knockdown cells. Overall, we elucidated the inhibitory effect of 6,7,4'-THIF on sUV-induced MMPs and suggest PKCα as its direct molecular target. PMID:25415304

  8. A novel ligand-independent peptide inhibitor of TREM-1 suppresses tumor growth in human lung cancer xenografts and prolongs survival of mice with lipopolysaccharide-induced septic shock

    PubMed Central

    Sigalov, Alexander B.

    2014-01-01

    Triggering receptor expressed on myeloid cells-1 (TREM-1) amplifies the inflammatory response and plays a role in cancer and sepsis. Inhibition of TREM-1 by short hairpin RNA (shRNA) in macrophages suppresses cancer cell invasion in vitro. In the clinical setting, high levels of TREM-1 expression on tumor-associated macrophages are associated with cancer recurrence and poor survival of patients with non-small cell lung cancer (NSCLC). TREM-1 upregulation on peritoneal neutrophils has been found in human sepsis patients and in mice with experimental lipopolysaccharide (LPS)-induced septic shock. However, the precise function of TREM-1 and the nature of its ligand are not yet known. In this study, we used the signaling chain homooligomerization (SCHOOL) model of immune signaling to design a novel, ligand-independent peptide-based TREM-1 inhibitor and demonstrated that this peptide specifically silences TREM-1 signaling in vitro and in vivo. Utilizing two human lung tumor xenograft nude mouse models (H292 and A549) and mice with LPS-induced sepsis, we show for the first time that blockade of TREM-1 function using non-toxic and non-immunogenic SCHOOL peptide inhibitors: 1) delays tumor growth in xenograft models of human NSCLC, 2) prolongs survival of mice with LPS-induced septic shock, and 3) substantially decreases cytokine production in vitro and in vivo. In addition, targeted delivery of SCHOOL peptides to macrophages utilizing lipoprotein-mimicking nanoparticles significantly increased peptide half-life and dosage efficacy. Together, the results suggest that ligand-independent modulation of TREM-1 function using small synthetic peptides might be a suitable treatment for sepsis and NSCLC and possibly other types of inflammation-associated disorders. PMID:24836682

  9. Statins, 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, potentiate the anti-angiogenic effects of bevacizumab by suppressing angiopoietin2, BiP, and Hsp90α in human colorectal cancer

    PubMed Central

    Lee, S J; Lee, I; Lee, J; Park, C; Kang, W K

    2014-01-01

    Background: Statins, 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, are commonly prescribed because of their therapeutic and preventive effects on cardiovascular diseases. Even though they have been occasionally reported to have antitumour activity, it is unknown whether statins have anti-angiogenic effect in human colorectal cancer (CRC). Methods: A total of 11 human CRC cell lines were used to test the effects of bevacizumab, statins, and bevacizumab plus statins on human umbilical vein endothelial cell (HUVEC) viability and invasion in vitro. To determine the molecular mechanism of statins as anti-angiogenic agents, we performed an angiogenesis antibody array and proteomics analysis and confirmed the results using immunoblot assay, HUVEC invasion rescue assay, and siRNA assay. The antitumoural effects of bevacizumab and statins were evaluated in xenograft models. Results: A conventional dose of statins (simvastatin 0.2 μM, lovastatin 0.4 μM, atorvastatin 0.1 μM, and pravastatin 0.4 μM) in combination with bevacizumab directly reduced the cell viability, migration, invasion, and tube formation of HUVECs. The culture media of the CRC cells treated with bevacizumab or statins were also found to inhibit HUVEC invasion by suppressing angiogenic mediators, such as angiopoietin2, binding immunoglobulin protein (BiP), and Hsp90α. The combined treatment with bevacizumab and simvastatin significantly reduced the growth and metastases of xenograft tumours compared with treatment with bevacizumab alone. Conclusions: The addition of simvastatin at a dose used in patients with cardiovascular diseases (40–80 mg once daily) may potentiate the anti-angiogenic effects of bevacizumab on CRC by suppressing angiopoietin2, BiP, and Hsp90α in cancer cells. A clinical trial of simvastatin in combination with bevacizumab in patients with CRC is needed. PMID:24945998

  10. Strong suppression of the renin-angiotensin system has a renal-protective effect in hypertensive patients: high-dose ARB with ACE inhibitor (Hawaii) study.

    PubMed

    Ohishi, Mitsuru; Takeya, Yasushi; Tatara, Yuji; Yamamoto, Koichi; Onishi, Miyuki; Maekawa, Yoshihiro; Kamide, Kei; Rakugi, Hiromi

    2010-11-01

    The principal means for reducing proteinuria in patients with chronic kidney disease are strong blockade of the renin-angiotensin system and strict regulation of blood pressure (BP). This study compared the efficacy of the maximum permissible doses of two common angiotensin receptor blockers (ARBs), namely valsartan (maximum dose=160 mg per day) and olmesartan (maximum dose=40 mg per day). We also investigated whether a high-dose ARB or the combination of an angiotensin-converting enzyme inhibitor with a high-dose ARB would be more renal protective. We recruited 87 poorly controlled hypertensive patients. In the first study, 50 patients without proteinuria were switched from valsartan (160 mg per day) to olmesartan (40 mg per day) for 4 months. In the second study, 37 patients with proteinuria were randomized to either switch from valsartan 160 mg per day to 40 mg per day olmesartan (n=19; Olm-G) or addition of 2.5-10 mg per day imidapril (stepped up by 2.5 mg per month) to valsartan at 160 mg per day (n=18; Imi-G). After 4 months, the BP level decreased (first study) from 157/88 mm Hg to 145/82 mm Hg (P<0.001) and (second study) from 149/86 mm Hg to 135/77 mm Hg and 145/82 mm Hg for Olm-G and Imi-G, respectively. Furthermore, in the second study, urinary protein/creatinine excretion was reduced from 2.0±1.8 g g⁻¹ to 0.8±0.8 g g⁻¹ (P=0.0242) in Olm-G and from 1.4±1.3 g g⁻¹ to 0.9±1.0 g g⁻¹ (P=0.0398) in Imi-G. The significance persisted after adjustment for BP or other risk factors. Our results suggested that the maximum dose of olmesartan was more effective than that of valsartan and comparable with the combination of valsartan and imidapril for reducing BP and proteinuria in poorly controlled hypertensive patients. PMID:20703230