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  1. Mesenchymal Stem Cells (MSC Regulate Activation of Granulocyte-Like Myeloid Derived Suppressor Cells (G-MDSC in Chronic Myeloid Leukemia Patients.

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    Cesarina Giallongo

    Full Text Available It is well known that mesenchymal stem cells (MSC have a role in promotion of tumor growth, survival and drug-resistance in chronic myeloid leukemia (CML. Recent reports indicated that a subpopulation of myeloid cells, defined as granulocyte-like myeloid-derived suppressor cells (G-MDSC is increased in these patients. So far, the role of MSC in MDSC expansion and activation into the BM microenvironment remains unexplored. To address this question, here we use a specific experimental model in vitro, co-culturing MSC with peripheral blood mononucleated cells (PBMC from normal individuals, in order to generate MSC-educated G-MDSC. Although MSC of healthy donors (HD and CML patients were able to generate the same amount of MDSC, only CML-MSC-educated G-MDSC exhibited suppressive ability on autologous T lymphocytes. In addition, compared with HD-MSC, CML-MSC over-expressed some immunomodulatory factors including TGFβ, IL6 and IL10, that could be involved in MDSC activation. CML-MSC-educated G-MDSC expressed higher levels of ARG1, TNFα, IL1β, COX2 and IL6 than G-MDSC isolated from co-culture with HD-MSC. Our data provide evidence that CML-MSC may play a critical role in tumor microenvironment by orchestrating G-MDSC activation and regulating T lymphocytes-mediated leukemia surveillance, thus contributing to CML immune escape.

  2. Mesenchymal Stem Cells (MSC) Regulate Activation of Granulocyte-Like Myeloid Derived Suppressor Cells (G-MDSC) in Chronic Myeloid Leukemia Patients.

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    Giallongo, Cesarina; Romano, Alessandra; Parrinello, Nunziatina Laura; La Cava, Piera; Brundo, Maria Violetta; Bramanti, Vincenzo; Stagno, Fabio; Vigneri, Paolo; Chiarenza, Annalisa; Palumbo, Giuseppe Alberto; Tibullo, Daniele; Di Raimondo, Francesco

    2016-01-01

    It is well known that mesenchymal stem cells (MSC) have a role in promotion of tumor growth, survival and drug-resistance in chronic myeloid leukemia (CML). Recent reports indicated that a subpopulation of myeloid cells, defined as granulocyte-like myeloid-derived suppressor cells (G-MDSC) is increased in these patients. So far, the role of MSC in MDSC expansion and activation into the BM microenvironment remains unexplored. To address this question, here we use a specific experimental model in vitro, co-culturing MSC with peripheral blood mononucleated cells (PBMC) from normal individuals, in order to generate MSC-educated G-MDSC. Although MSC of healthy donors (HD) and CML patients were able to generate the same amount of MDSC, only CML-MSC-educated G-MDSC exhibited suppressive ability on autologous T lymphocytes. In addition, compared with HD-MSC, CML-MSC over-expressed some immunomodulatory factors including TGFβ, IL6 and IL10, that could be involved in MDSC activation. CML-MSC-educated G-MDSC expressed higher levels of ARG1, TNFα, IL1β, COX2 and IL6 than G-MDSC isolated from co-culture with HD-MSC. Our data provide evidence that CML-MSC may play a critical role in tumor microenvironment by orchestrating G-MDSC activation and regulating T lymphocytes-mediated leukemia surveillance, thus contributing to CML immune escape.

  3. Granulocyte-like myeloid derived suppressor cells (G-MDSC) are increased in multiple myeloma and are driven by dysfunctional mesenchymal stem cells (MSC).

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    Giallongo, Cesarina; Tibullo, Daniele; Parrinello, Nunziatina L; La Cava, Piera; Di Rosa, Michelino; Bramanti, Vincenzo; Di Raimondo, Cosimo; Conticello, Concetta; Chiarenza, Annalisa; Palumbo, Giuseppe A; Avola, Roberto; Romano, Alessandra; Di Raimondo, Francesco

    2016-12-27

    Granulocytic-Myeloid-derived suppressor cells (G-MDSC) are increased in Multiple Myeloma (MM) patients but the mechanisms of G-MDSC generation are still unknown. There are many evidences of the role of mesenchymal stem cells (MSC) in promoting MM cell growth, survival and drug-resistance. We here used a specific experimental model in vitro to evaluate the ability of MSC to induce G-MDSC. We found that although MSC derived from healthy donors (HD), MGUS and MM were able to generate the same amount of MDSC, only MM-MSC-educated G-MDSC exhibited suppressive ability. In addition, in comparison with MSC derived from HD, MM-MSC produce higher amount of immune-modulatory factors that could be involved in MDSC induction. Compared to G-MDSC obtained from co-culture models with MSC from healthy subjects, both MGUS and MM-MSC-educated G-MDSC showed increase of immune-modulatory factors. However, only MM-MSC educated G-MDSC 1) up-regulated immune-suppressive factors as ARG1 and TNFα, 2) expressed higher levels of PROK2, important in angiogenesis and inflammatory process, and 3) showed ability to digest bone matrix.Our data demonstrate that MM-MSC are functionally different from healthy subjects and MGUS-MSC, supporting an evolving concept regarding the contribution of MM-MSC to tumor development and progression.

  4. Myeloid derived suppressor cells as therapeutic target in hematological malignancies

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    Kim eDe Veirman

    2014-12-01

    Full Text Available Myeloid derived suppressor cells (MDSC are a heterogeneous population of immature myeloid cells that accumulate during pathological conditions such as cancer and are associated with a poor clinical outcome. MDSC expansion hampers the host anti-tumor immune response by inhibition of T cell proliferation, cytokine secretion and recruitment of regulatory T cells. In addition, MDSC exert non-immunological functions including the promotion of angiogenesis, tumor invasion and metastasis. Recent years, MDSC are considered as a potential target in solid tumors and hematological malignancies to enhance the effects of currently used immune modulating agents. This review focuses on the characteristics, distribution, functions, cell-cell interactions and targeting of MDSC in hematological malignancies including multiple myeloma, lymphoma and leukemia.

  5. Arginase-1 mRNA expression correlates with myeloid-derived suppressor cell levels in peripheral blood of NSCLC patients

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    Heuvers, Marlies E.; Muskens, Femke; Bezemer, Koen; Lambers, Margaretha; Dingemans, Anne-Marie C.; Groen, Harry J. M.; Smit, Egbert F.; Hoogsteden, Henk C.; Hegmans, Joost P. J. J.; Aerts, Joachim G. J. V.

    Myeloid-derived suppressor cells (MDSC) are a heterogeneous population of immature and progenitor myeloid cells with immunosuppressive activity that are increased in cancer patients. Until now, the characterization of MDSC in humans was very challenging. The aim of this study was to determine the

  6. CD16xCD33 bispecific killer cell engager (BiKE) activates NK cells against primary MDS and MDSC CD33+ targets.

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    Gleason, Michelle K; Ross, Julie A; Warlick, Erica D; Lund, Troy C; Verneris, Michael R; Wiernik, Andres; Spellman, Stephen; Haagenson, Michael D; Lenvik, Alexander J; Litzow, Mark R; Epling-Burnette, Pearlie K; Blazar, Bruce R; Weiner, Louis M; Weisdorf, Daniel J; Vallera, Daniel A; Miller, Jeffrey S

    2014-05-08

    Myelodysplastic syndromes (MDS) are stem cell disorders that can progress to acute myeloid leukemia. Although hematopoietic cell transplantation can be curative, additional therapies are needed for a disease that disproportionally afflicts the elderly. We tested the ability of a CD16xCD33 BiKE to induce natural killer (NK) cell function in 67 MDS patients. Compared with age-matched normal controls, CD7(+) lymphocytes, NK cells, and CD16 expression were markedly decreased in MDS patients. Despite this, reverse antibody-dependent cell-mediated cytotoxicity assays showed potent degranulation and cytokine production when resting MDS-NK cells were triggered with an agonistic CD16 monoclonal antibody. Blood and marrow MDS-NK cells treated with bispecific killer cell engager (BiKE) significantly enhanced degranulation and tumor necrosis factor-α and interferon-γ production against HL-60 and endogenous CD33(+) MDS targets. MDS patients had a significantly increased proportion of immunosuppressive CD33(+) myeloid-derived suppressor cells (MDSCs) that negatively correlated with MDS lymphocyte populations and CD16 loss on NK cells. Treatment with the CD16xCD33 BiKE successfully reversed MDSC immunosuppression of NK cells and induced MDSC target cell lysis. Lastly, the BiKE induced optimal MDS-NK cell function irrespective of disease stage. Our data suggest that the CD16xCD33 BiKE functions against both CD33(+) MDS and MDSC targets and may be therapeutically beneficial for MDS patients.

  7. The role of myeloid-derived suppressor cells in immune ontogeny

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    Soren eGantt

    2014-08-01

    Full Text Available Myeloid derived suppressor cells (MDSC are a heterogeneous population of granulocytic or monocytic cells that suppress innate as well as adaptive immune responses. In healthy adults, immature myeloid cells differentiate into macrophages, dendritic cells, and granulocytes in the bone marrow, and MDSC are rarely detected in peripheral blood. However, in certain pathologies, in particular malignancies and chronic infection, differentiation of these cells is altered resulting in accumulation of circulating suppressive myeloid cells. MDSC express suppressive factors such as arginase-1, reactive oxygen species, and inducible nitric oxide synthase, which have the ability to inhibit T cell proliferation and cytoxicity, induce the expansion of regulatory T cells, and block natural killer cell activation. It is increasingly recognized that MDSC alter the immune response to several cancers, and perhaps chronic viral infections, in clinically important ways. In this review, we outline the potential contribution of MDSC to the generation of feto-maternal tolerance and to the ineffective immune responses to many infections and vaccines observed in early post-natal life. Granulocytic MDSC are present in large numbers in pregnant women and in cord blood, and wane rapidly during infancy. Furthermore, cord blood MDSC suppress in vitro T cell and NK responses, suggesting that they may play a significant role in human immune ontogeny. However, there are currently no data that demonstrate in vivo effects of MDSC on feto-maternal tolerance or immune ontogeny. Studies are ongoing to evaluate the functional importance of MDSC, including their effects on control of infection and response to vaccination in infancy. Importantly, several pharmacologic interventions have the potential to reverse MDSC function. Understanding the role of MDSC in infant ontogeny and their mechanisms of action could lead to interventions that reduce mortality due to early-life infections.

  8. Factors Influencing the Differentiation of Human Monocytic Myeloid-Derived Suppressor Cells Into Inflammatory Macrophages

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    Defne Bayik

    2018-03-01

    Full Text Available Monocytic myeloid-derived suppressor cells (mMDSC accumulate within tumors where they create an immunosuppressive milieu that inhibits the activity of cytotoxic T and NK cells thereby allowing cancers to evade immune elimination. The toll-like receptors 7/8 agonist R848 induces human mMDSC to mature into inflammatory macrophage (MACinflam. This work demonstrates that TNFα, IL-6, and IL-10 produced by maturing mMDSC are critical to the generation of MACinflam. Neutralizing any one of these cytokines significantly inhibits R848-dependent mMDSC differentiation. mMDSC cultured in pro-inflammatory cytokine IFNγ or the combination of TNFα plus IL-6 differentiate into MACinflam more efficiently than those treated with R848. These mMDSC-derived macrophages exert anti-tumor activity by killing cancer cells. RNA-Seq analysis of the genes expressed when mMDSC differentiate into MACinflam indicates that TNFα and the transcription factors NF-κB and STAT4 are major hubs regulating this process. These findings support the clinical evaluation of R848, IFNγ, and/or TNFα plus IL-6 for intratumoral therapy of established cancers.

  9. Phenotypically resembling myeloid derived suppressor cells are increased in children with HIV and exposed/infected with Mycobacterium tuberculosis.

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    Du Plessis, Nelita; Jacobs, Ruschca; Gutschmidt, Andrea; Fang, Zhuo; van Helden, Paul D; Lutz, Manfred B; Hesseling, Anneke C; Walzl, Gerhard

    2017-01-01

    Increased disease susceptibility during early life has been linked to immune immaturity, regulatory T-cell/TH2 immune biasing and hyporesponsiveness. The contribution of myeloid derived suppressor cells (MDSCs) remains uninvestigated. Here, we assessed peripheral MDSC in HIV-infected and -uninfected children with tuberculosis (TB) disease before, during and after TB treatment, along with matched household contacts (HHCs), HIV-exposed, -infected and -uninfected children without recent TB exposure. Serum analytes and enzymes associated with MDSC accumulation/activation/function were measured by colorimetric- and fluorescence arrays. Peripheral frequencies of cells phenotypically resembling MDSCs were significantly increased in HIV-exposed uninfected (HEU) and M.tb-infected children, but peaked in children with TB disease and remained high following treatment. MDSC in HIV-infected (HI) children were similar to unexposed uninfected controls; however, HAART-mediated MDSC restoration to control levels could not be disregarded. Increased MDSC frequencies in HHC coincided with enhanced indoleamine-pyrrole-2,3-dioxygenase (IDO), whereas increased MDSC in TB cases were linked to heightened IDO and arginase-1. Increased MDSC were paralleled by reduced plasma IP-10 and thrombospondin-2 levels in HEU and significantly increased plasma IL-6 in HI HHC. Current investigations into MDSC-targeted treatment strategies, together with functional analyses of MDSCs, could endorse these cells as novel innate immune regulatory mechanism of infant HIV/TB susceptibility. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Correlation between frequencies of blood monocytic myeloid-derived suppressor cells, regulatory T cells and negative prognostic markers in patients with castration-resistant metastatic prostate cancer

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    Idorn, Manja; Køllgaard, Tania; Kongsted, Per

    2014-01-01

    in establishing an immune suppressive environment in patients with PC. Moreover, correlation of M-MDSC frequency with known prognostic markers and the observed impact on OS could reflect a possible role in tumor progression. Further insight into the generation and function of MDSC and their interplay with Tregs......Myeloid-derived suppressor cells (MDSC) are believed to play a role in immune suppression and subsequent failure of T cells to mount an efficient anti-tumor response, by employing both direct T-cell inhibition as well as induction of regulatory T cells (Tregs). Investigating the frequency...... with known negative prognostic markers in patients with PC including elevated levels of lactate dehydrogenase and prostate-specific antigen. Accordingly, high levels of M-MDSC were associated with a shorter median overall survival. Our data strongly suggest that M-MDSC, possibly along with Tregs, play a role...

  11. Transmembrane Tumor Necrosis Factor Controls Myeloid-Derived Suppressor Cell Activity via TNF Receptor 2 and Protects from Excessive Inflammation during BCG-Induced Pleurisy

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    Leslie Chavez-Galan

    2017-08-01

    Full Text Available Pleural tuberculosis (TB is a form of extra-pulmonary TB observed in patients infected with Mycobacterium tuberculosis. Accumulation of myeloid-derived suppressor cells (MDSC has been observed in animal models of TB and in human patients but their role remains to be fully elucidated. In this study, we analyzed the role of transmembrane TNF (tmTNF in the accumulation and function of MDSC in the pleural cavity during an acute mycobacterial infection. Mycobacterium bovis BCG-induced pleurisy was resolved in mice expressing tmTNF, but lethal in the absence of tumor necrosis factor. Pleural infection induced MDSC accumulation in the pleural cavity and functional MDSC required tmTNF to suppress T cells as did pleural wild-type MDSC. Interaction of MDSC expressing tmTNF with CD4 T cells bearing TNF receptor 2 (TNFR2, but not TNFR1, was required for MDSC suppressive activity on CD4 T cells. Expression of tmTNF attenuated Th1 cell-mediated inflammatory responses generated by the acute pleural mycobacterial infection in association with effective MDSC expressing tmTNF and interacting with CD4 T cells expressing TNFR2. In conclusion, this study provides new insights into the crucial role played by the tmTNF/TNFR2 pathway in MDSC suppressive activity required during acute pleural infection to attenuate excessive inflammation generated by the infection.

  12. Critical role of mast cells and peroxisome proliferator-activated receptor gamma (PPARγ) in the induction of myeloid-derived suppressor cells by marijuana cannabidiol in vivo

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    Hegde, Venkatesh L.; Singh, Udai P.; Nagarkatti, Prakash S.; Nagarkatti, Mitzi

    2015-01-01

    Cannabidiol (CBD) is a natural non-psychotropic cannabinoid from marijuana (Cannabis sativa) with anti-epileptic and anti-inflammatory properties. Effect of CBD on naïve immune system is not precisely understood. In this study, we observed that administering CBD into naïve mice triggers robust induction of CD11b+Gr-1+ MDSC in the peritoneum, which expressed functional Arg1, and potently suppressed T cell proliferation ex vivo. Further, CBD-MDSC suppressed LPS-induced acute inflammatory response upon adoptive transfer in vivo. CBD-induced suppressor cells were comprised of CD11b+Ly6-G+Ly6-C+ granulocytic and CD11b+Ly6-G−Ly6-C+ monocytic subtypes, with monocytic MDSC exhibiting higher T cell suppressive function. Induction of MDSC by CBD was markedly attenuated in Kit-mutant (KitW/W-v) mast cell-deficient mice. MDSC response was reconstituted upon transfer of WT bone marrow-derived mast cells in KitW/W-v mice suggesting the key role of cKit (CD117) as well as mast cells. Moreover, mast cell activator compound 48/80 induced significant levels of MDSC in vivo. CBD administration in mice induced G-CSF, CXCL1 and M-CSF, but not GM-CSF. G-CSF was found to play a key role in MDSC mobilization inasmuch as neutralizing G-CSF caused a significant decrease in MDSC. Lastly, CBD enhanced the transcriptional activity of PPARγ in luciferase reporter assay, and PPARγ selective antagonist completely inhibited MDSC induction in vivo suggesting its critical role. Together, the results suggest that CBD may induce activation of PPARγ in mast cells leading to secretion of G-CSF and consequent MDSC mobilization. CBD being a major component of Cannabis, our study indicates that marijuana may modulate or dysregulate the immune system by mobilizing MDSC. PMID:25917103

  13. Pancreatic Cancer Cells Isolated from Muc1-null Tumors Favor the Generation of a Mature Less Suppressive MDSC Population

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    Amritha eKidiyoor

    2014-02-01

    Full Text Available Mucin 1 (MUC1 is a transmembrane mucin glycoprotein that is over-expressed and aberrantly glycosylated in >80% of human pancreatic ductal adenocarcinoma (PDA and is associated with poor prognosis. To understand the role of MUC1 in PDA, we have recently developed two mouse models of spontaneous PDA, one that expresses full-length human MUC1 transgene (KCM mice and one that is null for MUC1 (KCKO mice. We have previously reported that KCM mice express high levels of myeloid derived suppressor cells (MDSCs in their tumors and develop highly aggressive PDA. To further understand the underlying mechanism for high MDSC levels in KCM tumors, we generated primary cell lines from KCM and KCKO tumors. In this study, we report that MDSCs derived using KCM cells express significantly higher levels of arginase 1 and inducible nitric oxide synthase (markers associated with immune suppression and lower levels of CD115 (a marker associated with maturation of myeloid cells as compared to KCKO-derived MDSCs. Functionally, KCM-derived MDSCs secrete significantly higher levels of urea and nitric oxide when co-cultured with normal splenic cells as compared to KCKO-derived MDSCs. Data indicates that KCM-derived MDSCs remain immature and are more suppressive as compared to KCKO-derived MDSCs. This was further corroborated in vivo where MDSCs isolated from KCM-tumor bearing mice retained their immature state and were highly suppressive as compared to MDSCs derived from KCKO-tumor bearing mice. Finally, we show that KCM cells secrete significantly higher levels of prostaglandin E2 (PGE2,, a COX-2 metabolite and a known driver of suppressive MDSCs as compared to KCKO cells. Thus, inhibiting PGE2 with a specific COX-2 inhibitor reverses the immunosuppressive and immature phenotype of KCM-derived MDSCs. This is the first report that clearly suggests a functional role of pancreatic tumor-associated MUC1 in the development of functional MDSCs.

  14. Myeloid-derived suppressor cells restrain Natural Killer cell activity in CVB3 myocarditis

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    Holz, Lisa Maria

    2017-01-01

    Murine models of coxsackievirus B3 (CVB3) induced myocarditis (with host specific outcomes), represent different outcome of myocarditis, ranging from virus elimination and complete recovery in resistant C57BL/6J mice to virus persistence and chronic myocarditis in susceptible A.BY/SnJ mice. In previous experiments, we found that Natural Killer cells (NK cells) positively influence the outcome of CVB3 myocarditis in mice. Myeloid-derived suppressor cells (MDSC) are potent inhibitors of the inn...

  15. Monocytic myeloid-derived suppressor cells as prognostic factor in chronic myeloid leukaemia patients treated with dasatinib.

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    Giallongo, Cesarina; Parrinello, Nunziatina L; La Cava, Piera; Camiolo, Giuseppina; Romano, Alessandra; Scalia, Marina; Stagno, Fabio; Palumbo, Giuseppe A; Avola, Roberto; Li Volti, Giovanni; Tibullo, Daniele; Di Raimondo, Francesco

    2018-02-01

    Myeloid suppressor cells are a heterogeneous group of myeloid cells that are increased in patients with chronic myeloid leukaemia (CML) inducing T cell tolerance. In this study, we found that therapy with tyrosine kinase inhibitors (TKI) decreased the percentage of granulocytic MDSC, but only patients treated with dasatinib showed a significant reduction in the monocytic subset (M-MDSC). Moreover, a positive correlation was observed between number of persistent M-MDSC and the value of major molecular response in dasatinib-treated patients. Serum and exosomes from patients with CML induced conversion of monocytes from healthy volunteers into immunosuppressive M-MDSC, suggesting a bidirectional crosstalk between CML cells and MDSC. Overall, we identified M-MDSC as prognostic factors in patients treated with dasatinib. It might be of interest to understand whether MDSC may be a candidate predictive markers of relapse risk following TKI discontinuation, suggesting their potential significance as practice of precision medicine. © 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  16. The Role of Myeloid-Derived Suppressor Cells in the Immunotherapy of HER2/neu-Positive Breast Carcinomas

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    2009-10-01

    applications beyond cancer immunotherapy, since increased MDSC have also been seen in some para- sitic infections such as Trypanosoma cruzi [17] and in cases...during acute Trypanosoma cruzi infection: involvement of Ly6G (Gr1(+))CD11b(+)immature myeloid suppressor cells. Int Immu- nol 14(10):1125–1134 18. Guy

  17. Ubiquitin Conjugation Probed by Inflammation in Myeloid-Derived Suppressor Cell Extracellular Vesicles.

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    Adams, Katherine R; Chauhan, Sitara; Patel, Divya B; Clements, Virginia K; Wang, Yan; Jay, Steven M; Edwards, Nathan J; Ostrand-Rosenberg, Suzanne; Fenselau, Catherine

    2018-01-05

    Ubiquitinated proteins carried by the extracellular vesicles (EV) released by myeloid-derived suppressor cells (MDSC) have been investigated using proteomic strategies to examine the effect of tumor-associated inflammation. EV were collected from MDSC directly following isolation from tumor-bearing mice with low and high inflammation. Among the 1092 proteins (high inflammation) and 925 proteins (low inflammation) identified, more than 50% were observed as ubiquitinated proteoforms. More than three ubiquitin-attachment sites were characterized per ubiquitinated protein, on average. Multiple ubiquitination sites were identified in the pro-inflammatory proteins S100 A8 and S100 A9, characteristic of MDSC and in histones and transcription regulators among other proteins. Spectral counting and pathway analysis suggest that ubiquitination occurs independently of inflammation. Some ubiquitinated proteins were shown to cause the migration of MDSC, which has been previously connected with immune suppression and tumor progression. Finally, MDSC EV are found collectively to carry all the enzymes required to catalyze ubiquitination, and the hypothesis is presented that a portion of the ubiquitinated proteins are produced in situ.

  18. CD40 dependent exacerbation of immune mediated hepatitis by hepatic CD11b+ Gr-1+ myeloid derived suppressor cells in tumor bearing mice

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    Kapanadze, Tamar; Medina-Echeverz, José; Gamrekelashvili, Jaba; Weiss, Jonathan M.; Wiltrout, Robert H.; Kapoor, Veena; Hawk, Nga; Terabe, Masaki; Berzofsky, Jay A.; Manns, Michael P.; Wang, Ena; Marincola, Francesco M.; Korangy, Firouzeh; Greten, Tim F.

    2015-01-01

    Immunosuppressive CD11b+Gr-1+ myeloid-derived suppressor cells (MDSC) accumulate in the livers of tumor-bearing mice. We studied hepatic MDSC in two murine models of immune mediated hepatitis. Unexpectedly, treatment of tumor bearing mice with Concanavalin A or α-Galactosylceramide resulted in increased ALT and AST serum levels in comparison to tumor free mice. Adoptive transfer of hepatic MDSC into naïve mice exacerbated Concanavalin A induced liver damage. Hepatic CD11b+Gr-1+ cells revealed a polarized pro-inflammatory gene signature after Concanavalin A treatment. An interferon gamma- dependent up-regulation of CD40 on hepatic CD11b+Gr-1+ cells along with an up-regulation of CD80, CD86, and CD1d after Concanavalin A treatment was observed. Concanavalin A treatment resulted in a loss of suppressor function by tumor-induced CD11b+Gr-1+ MDSC as well as enhanced reactive oxygen species-mediated hepatotoxicity. CD40 knockdown in hepatic MDSC led to increased arginase activity upon Concanavalin A treatment and lower ALT/AST serum levels. Finally, blockade of arginase activity in Cd40−/− tumor-induced myeloid cells resulted in exacerbation of hepatitis and increased reactive oxygen species production in vivo. Our findings indicate that in a setting of acute hepatitis, tumor-induced hepatic MDSC act as pro-inflammatory immune effector cells capable of killing hepatocytes in a CD40-dependent manner. PMID:25616156

  19. Liver myeloid-derived suppressor cells expand in response to liver metastases in mice and inhibit the anti-tumor efficacy of anti-CEA CAR-T

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    Burga, Rachel A.; Thorn, Mitchell; Point, Gary R.; Guha, Prajna; Nguyen, Cang T.; Licata, Lauren A.; DeMatteo, Ronald P.; Ayala, Alfred; Espat, N. Joseph; Junghans, Richard P.; Katz, Steven C.

    2015-01-01

    Chimeric antigen receptor modified T cell (CAR-T) technology, a promising immunotherapeutic tool, has not been applied specifically to treat liver metastases (LM). While CAR-T delivery to LM can be optimized by regional intrahepatic infusion, we propose that liver CD11b+Gr-1+ myeloid-derived suppressor cells (L-MDSC) will inhibit the efficacy of CAR-T in the intrahepatic space. We studied anti-CEA CAR-T in a murine model of CEA+ LM and identified mechanisms through which L-MDSC expand and inhibit CAR-T function. We established CEA+ LM in mice and studied purified L-MDSC and responses to treatment with intrahepatic anti-CEA CAR-T infusions. L-MDSC expanded three-fold in response to LM and their expansion was dependent on GM-CSF, which was produced by tumor cells. L-MDSC utilized PD-L1 to suppress anti-tumor responses through engagement of PD-1 on CAR-T. GM-CSF, in cooperation with STAT3, promoted L-MDSC PD-L1 expression. CAR-T efficacy was rescued when mice received CAR-T in combination with MDSC depletion, GM-CSF neutralization to prevent MDSC expansion, or PD-L1 blockade. As L-MDSC suppressed anti-CEA CAR-T, infusion of anti-CEA CAR-T in tandem with agents targeting L-MDSC is a rational strategy for future clinical trials. PMID:25850344

  20. Inhibiting HSP90 prevents the induction of myeloid-derived suppressor cells by melanoma cells.

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    Janssen, Nicole; Speigl, Lisa; Pawelec, Graham; Niessner, Heike; Shipp, Christopher

    2018-02-21

    Metastatic melanoma is the most dangerous form of skin cancer, with an ever-increasing incidence worldwide. Despite encouraging results with immunotherapeutic approaches, long-term survival is still poor. This is likely partly due to tumour-induced immune suppression mediated by myeloid-derived suppressor cells (MDSCs), which were shown to be associated with response to therapy and survival. Thus, identifying pathways responsible for MDSC differentiation may provide new therapeutic targets and improve efficacy of existing immunotherapies. Therefore, we've analysed mechanisms by which tumour cells contribute to the induction of MDSCs. Established melanoma cell lines were pre-treated with inhibitors of different pathways and tested for their capacity to alleviate T cell suppression via MDSC differentiation in vitro. Targeting HSP70/90 in melanoma cells resulted in reduced induction of immune suppressive cells on a phenotypic and functional basis, for which a more potent effect was observed when HSP90 was inhibited under hypoxic conditions. This initial study suggests a novel mechanism in tumour cells responsible for the induction of MDSC in melanoma. Copyright © 2018. Published by Elsevier Inc.

  1. Drafting the proteome landscape of myeloid-derived suppressor cells.

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    Gato, María; Blanco-Luquin, Idoia; Zudaire, Maribel; de Morentin, Xabier Martínez; Perez-Valderrama, Estela; Zabaleta, Aintzane; Kochan, Grazyna; Escors, David; Fernandez-Irigoyen, Joaquín; Santamaría, Enrique

    2016-01-01

    Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of cells that are defined by their myeloid origin, immature state, and ability to potently suppress T-cell responses. They regulate immune responses and the population significantly increases in the tumor microenvironment of patients with glioma and other malignant tumors. For their study, MDSCs are usually isolated from the spleen or directly of tumors from a large number of tumor-bearing mice although promising ex vivo differentiated MDSC production systems have been recently developed. During the last years, proteomics has emerged as a powerful approach to analyze MDSCs proteomes using shotgun-based mass spectrometry (MS), providing functional information about cellular homeostasis and metabolic state at a global level. Here, we will revise recent proteome profiling studies performed in MDSCs from different origins. Moreover, we will perform an integrative functional analysis of the protein compilation derived from these large-scale proteomic studies in order to obtain a comprehensive view of MDSCs biology. Finally, we will also discuss the potential application of high-throughput proteomic approaches to study global proteome dynamics and post-translational modifications (PTMs) during the differentiation process of MDSCs that will greatly boost the identification of novel MDSC-specific therapeutic targets to apply in cancer immunotherapy. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. LMP1-mediated glycolysis induces myeloid-derived suppressor cell expansion in nasopharyngeal carcinoma

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    Cai, Ting-Ting; Ye, Shu-Biao; Liu, Yi-Na; He, Jia; Chen, Qiu-Yan; Mai, Hai-Qiang; Zhang, Chuan-Xia; Cui, Jun; Zhang, Xiao-Shi; Zeng, Yi-Xin

    2017-01-01

    Myeloid-derived suppressor cells (MDSCs) are expanded in tumor microenvironments, including that of Epstein–Barr virus (EBV)-associated nasopharyngeal carcinoma (NPC). The link between MDSC expansion and EBV infection in NPC is unclear. Here, we show that EBV latent membrane protein 1 (LMP1) promotes MDSC expansion in the tumor microenvironment by promoting extra-mitochondrial glycolysis in malignant cells, which is a scenario for immune escape initially suggested by the frequent, concomitant detection of abundant LMP1, glucose transporter 1 (GLUT1) and CD33+ MDSCs in tumor sections. The full process has been reconstituted in vitro. LMP1 promotes the expression of multiple glycolytic genes, including GLUT1. This metabolic reprogramming results in increased expression of the Nod-like receptor family protein 3 (NLRP3) inflammasome, COX-2 and P-p65 and, consequently, increased production of IL-1β, IL-6 and GM-CSF. Finally, these changes in the environment of malignant cells result in enhanced NPC-derived MDSC induction. One key step is the physical interaction of LMP1 with GLUT1 to stabilize the GLUT1 protein by blocking its K48-ubiquitination and p62-dependent autolysosomal degradation. This work indicates that LMP1-mediated glycolysis regulates IL-1β, IL-6 and GM-CSF production through the NLRP3 inflammasome, COX-2 and P-p65 signaling pathways to enhance tumor-associated MDSC expansion, which leads to tumor immunosuppression in NPC. PMID:28732079

  3. Transcriptomic analysis comparing tumor-associated neutrophils with granulocytic myeloid-derived suppressor cells and normal neutrophils.

    Directory of Open Access Journals (Sweden)

    Zvi G Fridlender

    Full Text Available The role of myeloid cells in supporting cancer growth is well established. Most work has focused on myeloid-derived suppressor cells (MDSC that accumulate in tumor-bearing animals, but tumor-associated neutrophils (TAN are also known to be capable of augmenting tumor growth. However, little is known about their evolution, phenotype, and relationship to naïve neutrophils (NN and to the granulocytic fraction of MDSC (G-MDSC.In the current study, a transcriptomics approach was used in mice to compare these cell types. Our data show that the three populations of neutrophils are significantly different in their mRNA profiles with NN and G-MDSC being more closely related to each other than to TAN. Structural genes and genes related to cell-cytotoxicity (i.e. respiratory burst were significantly down-regulated in TAN. In contrast, many immune-related genes and pathways, including genes related to the antigen presenting complex (e.g. all six MHC-II complex genes, and cytokines (e.g. TNF-α, IL-1-α/β, were up-regulated in G-MDSC, and further up-regulated in TAN. Thirteen of the 25 chemokines tested were markedly up-regulated in TAN compared to NN, including striking up-regulation of chemoattractants for T/B-cells, neutrophils and macrophages.This study characterizes different populations of neutrophils related to cancer, pointing out the major differences between TAN and the other neutrophil populations.

  4. Toward harmonized phenotyping of human myeloid-derived suppressor cells by flow cytometry: results from an interim study.

    Science.gov (United States)

    Mandruzzato, Susanna; Brandau, Sven; Britten, Cedrik M; Bronte, Vincenzo; Damuzzo, Vera; Gouttefangeas, Cécile; Maurer, Dominik; Ottensmeier, Christian; van der Burg, Sjoerd H; Welters, Marij J P; Walter, Steffen

    2016-02-01

    There is an increasing interest for monitoring circulating myeloid-derived suppressor cells (MDSCs) in cancer patients, but there are also divergences in their phenotypic definition. To overcome this obstacle, the Cancer Immunoguiding Program under the umbrella of the Association of Cancer Immunotherapy is coordinating a proficiency panel program that aims at harmonizing MDSC phenotyping. After a consultation period, a two-stage approach was designed to harmonize MDSC phenotype. In the first step, an international consortium of 23 laboratories immunophenotyped 10 putative MDSC subsets on pretested, peripheral blood mononuclear cells of healthy donors to assess the level of concordance and define robust marker combinations for the identification of circulating MDSCs. At this stage, no mandatory requirements to standardize reagents or protocols were introduced. Data analysis revealed a small intra-laboratory, but very high inter-laboratory variance for all MDSC subsets, especially for the granulocytic subsets. In particular, the use of a dead-cell marker altered significantly the reported percentage of granulocytic MDSCs, confirming that these cells are especially sensitive to cryopreservation and/or thawing. Importantly, the gating strategy was heterogeneous and associated with high inter-center variance. Overall, our results document the high variability in MDSC phenotyping in the multicenter setting if no harmonization/standardization measures are applied. Although the observed variability depended on a number of identified parameters, the main parameter associated with variation was the gating strategy. Based on these findings, we propose further efforts to harmonize marker combinations and gating parameters to identify strategies for a robust enumeration of MDSC subsets.

  5. Myeloid-Derived Suppressor Cells: Possible Link Between Chronic Obstrucive Pulmonary Disease and Lung Cancer.

    Science.gov (United States)

    Scrimini, Sergio; Pons, Jaume; Sauleda, Jaume

    2016-01-01

    Chronic obstructive pulmonary disease (COPD) and lung cancer (LC) are prevalent diseases and are a leading cause of morbidity and mortality worldwide. There is strong evidence to show that COPD is an independent risk factor for LC. Chronic inflammation plays a significant pathogenic role in COPD comorbidities, particularly in LC. On the one hand, cellular and molecular inflammatory mediators promote carcinogenesis and, on the other, chronic inflammation impairs the capacity of the immune system to identify and destroy pre-malignant and malignant cells, a process known as tumor immune surveillance. This altered antitumor immunity is due in part to the expansion of myeloid-derived suppressor cells (MDSC), which are characterized by an ability to suppress the antitumor activity of T-cells by down-regulation of the T-cell receptor ζ chain (TCRζ) through the catabolism of L-arginine. COPD and LC patients share a common pattern of expansion and activation of circulating MDSC associated with TCRζ downregulation and impaired peripheral T-cell function. The objectives of this study were to review the evidence on the association between COPD and LC and to analyze how MDSC accumulation may alter tumor immune surveillance in COPD, and therefore, promote LC development. Copyright © 2015 SEPAR. Published by Elsevier Espana. All rights reserved.

  6. Requirement for Interactions of Natural Killer T Cells and Myeloid Derived Suppressor Cells for Transplantation Tolerance

    Science.gov (United States)

    Hongo, David; Tang, Xiaobin; Baker, Jeanette; Engleman, Edgar G.; Strober, Samuel

    2014-01-01

    The goal of the study was to elucidate the cellular and molecular mechanisms by which a clinically applicable immune tolerance regimen of combined bone marrow and heart transplants in mice results in mixed chimerism and graft acceptance. The conditioning regimen of lymphoid irradiation and anti-T cell antibodies changed the balance of cells in the lymphoid tissues to create a tolerogenic microenvironment favoring the increase of natural killer T (NKT) cells, CD4+CD25+ Tregs, and Gr-1+CD11b+ myeloid derived suppressor cells (MDSCs), over conventional T cells. The depletion of MDSCs abrogated chimerism and tolerance, and add back of these purified cells was restorative. The conditioning regimen activated the MDSCs as judged by the increased expression of arginase-1, IL-4Rα, and PDL1, and the activated cells gained the capacity to suppress the proliferation of conventional T cells to alloantigens in the mixed leukocyte reaction. MDSC activation was dependent on the presence of host invariant NKT cells. The conditioning regimen polarized the host invariant NKT cells toward IL-4 secretion, and MDSC activation was dependent on IL-4. In conclusion, there was a requirement for MDSCs for chimerism and tolerance, and their suppressive function was dependent on their interactions with NKT cells and IL-4. PMID:25311657

  7. Targeting myeloid-derived suppressor cells augments antitumor activity against lung cancer

    Directory of Open Access Journals (Sweden)

    Srivastava MK

    2012-10-01

    Full Text Available Minu K Srivastava,1,2 Li Zhu,1,2 Marni Harris-White,2 Min Huang,1–3 Maie St John,1,3 Jay M Lee,1,3 Ravi Salgia,4 Robert B Cameron,1,3,5 Robert Strieter,6 Steven Dubinett,1–3 Sherven Sharma1–31Department of Medicine, UCLA Lung Cancer Research Program, David Geffen School of Medicine at UCLA, Los Angeles, CA, 2Molecular Gene Medicine Laboratory, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, 3Jonsson Comprehensive Cancer Center, David Geffen School of Medicine at UCLA, Los Angeles, CA, 4Department of Medicine, University of Chicago, Chicago, IL, 5Department of Surgery, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, 6Department of Medicine, University of Virginia, Charlottesville, VA, USAAbstract: Lung cancer evades host immune surveillance by dysregulating inflammation. Tumors and their surrounding stromata produce growth factors, cytokines, and chemokines that recruit, expand, and/or activate myeloid-derived suppressor cells (MDSCs. MDSCs regulate immune responses and are frequently found in malignancy. In this review the authors discuss tumor-MDSC interactions that suppress host antitumor activities and the authors' recent findings regarding MDSC depletion that led to improved therapeutic vaccination responses against lung cancer. Despite the identification of a repertoire of tumor antigens, hurdles persist for immune-based anticancer therapies. It is likely that combined therapies that address the multiple immune deficits in cancer patients will be required for effective therapy. MDSCs play a major role in the suppression of T-cell activation and they sustain tumor growth, proliferation, and metastases. Regulation of MDSC recruitment, differentiation or expansion, and inhibition of the MDSC suppressive function with pharmacologic agents will be useful in the control of cancer growth and progression. Pharmacologic agents that regulate MDSCs may be more effective when combined with

  8. Modulating glioma-mediated myeloid-derived suppressor cell development with sulforaphane.

    Directory of Open Access Journals (Sweden)

    Ravi Kumar

    Full Text Available Glioblastoma is the most common primary tumor of the brain and has few long-term survivors. The local and systemic immunosuppressive environment created by glioblastoma allows it to evade immunosurveillance. Myeloid-derived suppressor cells (MDSCs are a critical component of this immunosuppression. Understanding mechanisms of MDSC formation and function are key to developing effective immunotherapies. In this study, we developed a novel model to reliably generate human MDSCs from healthy-donor CD14+ monocytes by culture in human glioma-conditioned media. Monocytic MDSC frequency was assessed by flow cytometry and confocal microscopy. The resulting MDSCs robustly inhibited T cell proliferation. A cytokine array identified multiple components of the GCM potentially contributing to MDSC generation, including Monocyte Chemoattractive Protein-1, interleukin-6, interleukin-8, and Macrophage Migration Inhibitory Factor (MIF. Of these, Macrophage Migration Inhibitory Factor is a particularly attractive therapeutic target as sulforaphane, a naturally occurring MIF inhibitor derived from broccoli sprouts, has excellent oral bioavailability. Sulforaphane inhibits the transformation of normal monocytes to MDSCs by glioma-conditioned media in vitro at pharmacologically relevant concentrations that are non-toxic to normal leukocytes. This is associated with a corresponding increase in mature dendritic cells. Interestingly, sulforaphane treatment had similar pro-inflammatory effects on normal monocytes in fresh media but specifically increased immature dendritic cells. Thus, we have used a simple in vitro model system to identify a novel contributor to glioblastoma immunosuppression for which a natural inhibitor exists that increases mature dendritic cell development at the expense of myeloid-derived suppressor cells when normal monocytes are exposed to glioma conditioned media.

  9. A clinical and biological perspective of human myeloid-derived suppressor cells in cancer.

    Science.gov (United States)

    Shipp, Christopher; Speigl, Lisa; Janssen, Nicole; Martens, Alexander; Pawelec, Graham

    2016-11-01

    Considering the large number of studies focused on myeloid-derived suppressor cells (MDSCs) to date, only a handful of well-defined relationships in human cancer have been established. The difficulty of assessing the impact of MDSCs in human cancer is partly due to the relatively small number of studies performed in humans. This is compounded in the literature by a common lack of clear indication of which species is being referred to for each characteristic described. These aspects may result in inappropriate extrapolation of animal studies to those in the human setting. This is especially the case for studies focused on investigating therapies which can be used to target MDSCs or those aimed at understanding their mechanism. Here, we attempt to rectify this by reviewing only studies on MDSC performed in humans. We survey studies which explore (1) whether MDSC levels are altered in cancer patients and if this is correlated with patient survival, (2) the so far identified mechanisms employed by MDSC to exert immune suppression, and (3) whether therapeutic agents can be used to target MDSCs by either altering their level, influencing their differentiation or inhibiting their suppressive function. Despite the fact that these studies clearly show that MDSCs are important in human cancer, the clinical employment of agents intended to target them has not yet been accomplished. We identify factors which have contributed to this and propose steps which may facilitate the translation of these therapies to the clinic in future.

  10. Prophylactic DNA vaccine targeting Foxp3+ regulatory T cells depletes myeloid-derived suppressor cells and improves anti-melanoma immune responses in a murine model.

    Science.gov (United States)

    Namdar, Afshin; Mirzaei, Reza; Memarnejadian, Arash; Boghosian, Roobina; Samadi, Morteza; Mirzaei, Hamid Reza; Farajifard, Hamid; Zavar, Mehdi; Azadmanesh, Kayhan; Elahi, Shokrollah; Noorbakhsh, Farshid; Rezaei, Abbas; Hadjati, Jamshid

    2018-03-01

    Regulatory T cells (Treg) and myeloid-derived suppressor cells (MDSC) are the two important and interactive immunosuppressive components of the tumor microenvironment that hamper anti-tumor immune responses. Therefore, targeting these two populations together might be beneficial for overcoming immune suppression in the tumor microenvironment. We have recently shown that prophylactic Foxp3 DNA/recombinant protein vaccine (Foxp3 vaccine) promotes immunity against Treg in tumor-free conditions. In the present study, we investigated the immune modulatory effects of a prophylactic regimen of the redesigned Foxp3 vaccine in the B16F10 melanoma model. Our results indicate that Foxp3 vaccination continuously reduces Treg population in both the tumor site and the spleen. Surprisingly, Treg reduction was associated with a significant decrease in the frequency of MDSC, both in the spleen and in the tumor environment. Furthermore, Foxp3 vaccination resulted in a significant reduction of arginase-1(Arg-1)-induced nitric oxide synthase (iNOS), reactive oxygen species (ROS) and suppressed MDSC activity. Moreover, this concurrent depletion restored production of inflammatory cytokine IFN-γ and enhanced tumor-specific CTL response, which subsequently resulted in the reduction of tumor growth and the improved survival rate of vaccinated mice. In conclusion, our results revealed that Foxp3 vaccine promotes an immune response against tumor by targeting both Treg and MDSC, which could be exploited as a potential immunotherapy approach.

  11. No evidence that genetic variation in the myeloid-derived suppressor cell pathway influences ovarian cancer survival

    DEFF Research Database (Denmark)

    Sucheston-Campbell, Lara E; Cannioto, Rikki; Clay, Alyssa I

    2017-01-01

    BACKGROUND: The precise mechanism by which the immune system is adversely affected in cancer patients remains poorly understood, but the accumulation of immune suppressive/pro-tumorigenic myeloid-derived suppressor cells (MDSCs) is thought to be one prominent mechanism contributing to immunologic...... tolerance of malignant cells in epithelial ovarian cancer (EOC). To this end, we hypothesized genetic variation in MDSC pathway genes would be associated with survival after EOC diagnoses. METHODS: We measured the hazard of death due to EOC within 10 years of diagnosis, overall and by invasive subtype...

  12. Myeloid-derived suppressor cells contribute to Staphylococcus aureus orthopedic biofilm infection.

    Science.gov (United States)

    Heim, Cortney E; Vidlak, Debbie; Scherr, Tyler D; Kozel, Jessica A; Holzapfel, Melissa; Muirhead, David E; Kielian, Tammy

    2014-04-15

    Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature monocytes and granulocytes that are potent inhibitors of T cell activation. A role for MDSCs in bacterial infections has only recently emerged, and nothing is known about MDSC function in the context of Staphylococcus aureus infection. Because S. aureus biofilms are capable of subverting immune-mediated clearance, we examined whether MDSCs could play a role in this process. CD11b(+)Gr-1(+) MDSCs represented the main cellular infiltrate during S. aureus orthopedic biofilm infection, accounting for >75% of the CD45+ population. Biofilm-associated MDSCs inhibited T cell proliferation and cytokine production, which correlated with a paucity of T cell infiltrates at the infection site. Analysis of FACS-purified MDSCs recovered from S. aureus biofilms revealed increased arginase-1, inducible NO synthase, and IL-10 expression, key mediators of MDSC suppressive activity. Targeted depletion of MDSCs and neutrophils using the mAb 1A8 (anti-Ly6G) improved bacterial clearance by enhancing the intrinsic proinflammatory attributes of infiltrating monocytes and macrophages. Furthermore, the ability of monocytes/macrophages to promote biofilm clearance in the absence of MDSC action was revealed with RB6-C85 (anti-Gr-1 or anti-Ly6G/Ly6C) administration, which resulted in significantly increased S. aureus burdens both locally and in the periphery, because effector Ly 6C monocytes and, by extension, mature macrophages were also depleted. Collectively, these results demonstrate that MDSCs are key contributors to the chronicity of S. aureus biofilm infection, as their immunosuppressive function prevents monocyte/macrophage proinflammatory activity, which facilitates biofilm persistence.

  13. Myeloid-derived suppressor cells (MDSCs) contribute to S. aureus orthopedic biofilm infection

    Science.gov (United States)

    Heim, Cortney E.; Vidlak, Debbie; Scherr, Tyler D.; Kozel, Jessica A.; Holzapfel, Melissa; Muirhead, David E.; Kielian, Tammy

    2014-01-01

    Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature monocytes and granulocytes that are potent inhibitors of T cell activation. A role for MDSCs in bacterial infections has only recently emerged and nothing is known about MDSC function in the context of Staphylococcus aureus (S. aureus) infection. Since S. aureus biofilms are capable of subverting immune-mediated clearance, we examined whether MDSCs could play a role in this process. CD11b+Gr-1+ MDSCs represented the main cellular infiltrate during S. aureus orthopedic biofilm infection, accounting for over 75% of the CD45+ population. Biofilm-associated MDSCs inhibited T cell proliferation and cytokine production, which correlated with a paucity of T cell infiltrates at the infection site. Analysis of FACS-purified MDSCs recovered from S. aureus biofilms revealed increased Arg-1, iNOS, and IL-10 expression, key mediators of MDSC suppressive activity. Targeted depletion of MDSCs and neutrophils using the mAb 1A8 (anti-Ly6G) improved bacterial clearance by enhancing the intrinsic pro-inflammatory attributes of infiltrating monocytes and macrophages. Furthermore, the ability of monocytes/macrophages to promote biofilm clearance in the absence of MDSC action was revealed with RB6-C85 (anti-Gr-1 or anti-Ly6G/Ly6C) administration, which resulted in significantly increased S. aureus burdens both locally and in the periphery, since effector Ly-6C monocytes and by extension, mature macrophages, were also depleted. Collectively, these results are the first to demonstrate that MDSCs are key contributors to the chronicity of S. aureus biofilm infection, as their immunosuppressive function prevents monocyte/macrophage proinflammatory activity, which facilitates biofilm persistence. PMID:24646737

  14. Calreticulin Fragment 39-272 Promotes B16 Melanoma Malignancy through Myeloid-Derived Suppressor Cells In Vivo

    Directory of Open Access Journals (Sweden)

    Xiao-Yan He

    2017-10-01

    Full Text Available Calreticulin (CRT, a multifunctional Ca2+-binding glycoprotein mainly located in the endoplasmic reticulum, is a tumor-associated antigen that has been shown to play protective roles in angiogenesis suppression and anti-tumor immunity. We previously reported that soluble CRT (sCRT was functionally similar to heat shock proteins or damage-associated molecular patterns in terms of ability to activate myeloid cells and elicit strong inflammatory cytokine production. In the present study, B16 melanoma cell lines expressing recombinant CRT fragment 39-272 (sCRT/39-272 in secreted form (B16-CRT, or recombinant enhanced green fluorescence protein (rEGFP (B16-EGFP, were constructed for investigation on the roles of sCRT in tumor development. When s.c. inoculated into C57BL/6 mice, the B16-CRT cells were significantly more aggressive (in terms of solid tumor growth rate than B16-EGFP controls in a TLR4- and myeloid-derived suppressor cells (MDSC-dependent manner. The B16-CRT-bearing mice showed increased Gr1+ MDSC infiltration in tumor tissues, accelerated proliferation of CD11b+Ly6G+Ly6Clow (G-MDSC precursors in bone marrow, and higher percentages of G-MDSCs in spleen and blood, which was mirrored by decreased percentage of dendritic cells (DC in periphery. In in vitro studies, recombinant sCRT/39-272 was able to promote migration and survival of tumor-derived MDSCs via interaction with TLR4, inhibit MDSC differentiation into DC, and also elicit expression of inflammatory proteins S100A8 and S100A9 which are essential for functional maturation and chemotactic migration of MDSCs. Our data provide solid evidence for CRT as a double-edged sword in tumor development.

  15. Myeloid-derived suppressor cells mediate immune suppression in spinal cord injury.

    Science.gov (United States)

    Wang, Lei; Yu, Wei-bo; Tao, Lian-yuan; Xu, Qing

    2016-01-15

    Spinal cord injury (SCI) is characterized by the loss of motor and sensory functions in areas below the level of the lesion and numerous accompanying deficits. Previous studies have suggested that myeloid-derived suppressor cell (MDSC)-induced immune depression may play a pivotal role in the course of SCI. However, the concrete mechanism of these changes regarding immune suppression remains unknown. Here, we created an SCI mouse model to gain further evidence regarding the relationship between MDSCs following SCI and T lymphocyte suppression. We showed that in the SCI mouse model, the expanding MDSCs have the capacity to suppress T cell proliferation, and this suppression could be reversed by blocking the arginase. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Pam2 lipopeptides systemically increase myeloid-derived suppressor cells through TLR2 signaling

    Energy Technology Data Exchange (ETDEWEB)

    Maruyama, Akira; Shime, Hiroaki, E-mail: shime@med.hokudai.ac.jp; Takeda, Yohei; Azuma, Masahiro; Matsumoto, Misako; Seya, Tsukasa, E-mail: seya-tu@pop.med.hokudai.ac.jp

    2015-02-13

    Myeloid-derived suppressor cells (MDSCs) are immature myeloid cells that exhibit potent immunosuppressive activity. They are increased in tumor-bearing hosts and contribute to tumor development. Toll-like receptors (TLRs) on MDSCs may modulate the tumor-supporting properties of MDSCs through pattern-recognition. Pam2 lipopeptides represented by Pam2CSK4 serve as a TLR2 agonist to exert anti-tumor function by dendritic cell (DC)-priming that leads to NK cell activation and cytotoxic T cell proliferation. On the other hand, TLR2 enhances tumor cell progression/invasion by activating tumor-infiltrating macrophages. How MDSCs respond to TLR2 agonists has not yet been determined. In this study, we found intravenous administration of Pam2CSK4 systemically up-regulated the frequency of MDSCs in EG7 tumor-bearing mice. The frequency of tumor-infiltrating MDSCs was accordingly increased in response to Pam2CSK4. MDSCs were not increased by Pam2CSK4 stimuli in TLR2 knockout (KO) mice. Adoptive transfer experiments using CFSE-labeled MDSCs revealed that the TLR2-positive MDSCs survived long in tumor-bearing mice in response to Pam2CSK4 treatment. Since the increased MDSC population sustained immune-suppressive properties, our study suggests that Pam2CSK4-triggered TLR2 activation enhances the MDSC potential and suppress antitumor immune response in tumor microenvironment. - Highlights: • Pam2CSK4 administration induces systemic accumulation of CD11b{sup +}Gr1{sup +} MDSCs. • TLR2 is essential for Pam2CSK4-induced accumulation of CD11b{sup +}Gr1{sup +} MDSCs. • Pam2CSK4 supports survival of CD11b{sup +}Gr1{sup +} MDSCs in vivo.

  17. Myeloid derived suppressor cells in multiple myeloma: preclinical research and translational opportunities

    Directory of Open Access Journals (Sweden)

    Cirino eBotta

    2014-12-01

    Full Text Available Immunosuppressive cells have been reported to play an important role in tumor progression mainly because of their capability to promote immune-escape, angiogenesis and metastasis. Among them, myeloid derived suppressor cells (MDSCs have been recently identified as immature myeloid cells, induced by tumor-associated inflammation, able to impair both innate and adaptive immunity. While murine MDSCs are usually identified by the expression of CD11b and Gr-1, human MDSCs represent a more heterogeneous population characterized by the expression of CD33 and CD11b, low or no HLA-DR and variable CD14 and CD15. In particular, the last two may alternatively identify monocyte-like or granulocyte-like MDSC subsets with different immunosuppressive properties. Recently, a substantial increase of MDSCs has been found in peripheral blood and bone marrow (BM of multiple myeloma (MM patients with a role in disease progression and/or drug resistance. Preclinical models recapitulating the complexity of the MM-related BM microenvironment (BMM are major tools for the study of the interactions between MM cells and cells of the BMM (including MDSCs and for the development of new agents targeting MM-associated immune suppressive cells.This review will focus on current strategies for human MDSCs generation and investigation of their immunosuppressive function in vitro and in vivo, taking into account the relevant relationship occurring within the MM-BMM. We will then provide trends in MDSC-associated research and suggest potential application for the treatment of MM.

  18. Silibinin inhibits accumulation of myeloid-derived suppressor cells and tumor growth of murine breast cancer

    International Nuclear Information System (INIS)

    Forghani, Parvin; Khorramizadeh, Mohammad R; Waller, Edmund K

    2014-01-01

    Myeloid-derived suppressor cells (MDSC)s increase in blood and accumulate in the tumor microenvironment of tumor-bearing animals, contributing to immune suppression in cancer. Silibinin, a natural flavonoid from the seeds of milk thistle, has been developed as an anti-inflammatory agent and supportive care agent to reduce the toxicity of cancer chemotherapy. The goals of this study were to evaluate the effect of silibinin on MDSCs in tumor-bearing mice and antitumor activity of silibinin in a mouse model of breast cancer. 4T1 luciferase-transfected mammary carcinoma cells were injected into in the mammary fat pad female BALB/c mice, and female CB17-Prkdc Scid/J mice. Silibinin treatment started on day 4 or day 14 after tumor inoculation continued every other day. Tumor growth was monitored by bioluminescent imaging (BLI) measuring total photon flux. Flow cytometry measured total leukocytes, CD11b + Gr-1 + MDSC, and T cells in the blood and tumors of tumor-bearing mice. The effects of silibinin on 4T1 cell viability in vitro were measured by BLI. Treatment with silibinin increased overall survival in mice harboring tumors derived from the 4T1-luciferase breast cancer cell line, and reduced tumor volumes and numbers of CD11b + Gr-1 + MDSCs in the blood and tumor, and increased the content of T cells in the tumor microenvironment. Silibinin failed to inhibit tumor growth in immunocompromised severe combined immunodeficiency mice, supporting the hypothesis that anticancer effect of silibinin is immune-mediated. The antitumor activity of silibinin requires an intact host immune system and is associated with decreased accumulation of blood and tumor-associated MDSCs

  19. Trans-sialidase-based vaccine candidate protects against Trypanosoma cruzi infection, not only inducing an effector immune response but also affecting cells with regulatory/suppressor phenotype

    Science.gov (United States)

    Prochetto, Estefanía; Roldán, Carolina; Bontempi, Iván A.; Bertona, Daiana; Peverengo, Luz; Vicco, Miguel H.; Rodeles, Luz M.; Pérez, Ana R.; Marcipar, Iván S.; Cabrera, Gabriel

    2017-01-01

    Prophylactic and/or therapeutic vaccines have an important potential to control Trypanosoma cruzi (T. cruzi)infection. The involvement of regulatory/suppressor immune cells after an immunization treatment and T. cruzi infection has never been addressed. Here we show that a new trans-sialidase-based immunogen (TSf) was able to confer protection, correlating not only with beneficial changes in effector immune parameters, but also influencing populations of cells related to immune control. Regarding the effector response, mice immunized with TSf showed a TS-specific antibody response, significant delayed-type hypersensitivity (DTH) reactivity and increased production of IFN-γ by CD8+ splenocytes. After a challenge with T. cruzi, TSf-immunized mice showed 90% survival and low parasitemia as compared with 40% survival and high parasitemia in PBS-immunized mice. In relation to the regulatory/suppressor arm of the immune system, after T. cruzi infection TSf-immunized mice showed an increase in spleen CD4+ Foxp3+ regulatory T cells (Treg) as compared to PBS-inoculated and infected mice. Moreover, although T. cruzi infection elicited a notable increase in myeloid derived suppressor cells (MDSC) in the spleen of PBS-inoculated mice, TSf-immunized mice showed a significantly lower increase of MDSC. Results presented herein highlight the need of studying the immune response as a whole when a vaccine candidate is rationally tested. PMID:28938533

  20. IRF-8 regulates expansion of myeloid-derived suppressor cells and Foxp3+ regulatory T cells and modulates Th2 immune responses to gastrointestinal nematode infection.

    Directory of Open Access Journals (Sweden)

    Rajesh M Valanparambil

    2017-10-01

    Full Text Available Interferon regulatory factor-8 (IRF-8 is critical for Th1 cell differentiation and negatively regulates myeloid cell development including myeloid-derived suppressor cells (MDSC. MDSC expand during infection with various pathogens including the gastrointestinal (GI nematode Heligmosomoides polygyrus bakeri (Hpb. We investigated if IRF-8 contributes to Th2 immunity to Hpb infection. Irf8 expression was down-regulated in MDSC from Hpb-infected C57BL/6 (B6 mice. IRF-8 deficient Irf8-/- and BXH-2 mice had significantly higher adult worm burdens than B6 mice after primary or challenge Hpb infection. During primary infection, MDSC expanded to a significantly greater extent in mesenteric lymph nodes (MLN and spleens of Irf8-/- and BXH-2 than B6 mice. CD4+GATA3+ T cells numbers were comparable in MLN of infected B6 and IRF-8 deficient mice, but MLN cells from infected IRF-8 deficient mice secreted significantly less parasite-specific IL-4 ex vivo. The numbers of alternatively activated macrophages in MLN and serum levels of Hpb-specific IgG1 and IgE were also significantly less in infected Irf8-/- than B6 mice. The frequencies of antigen-experienced CD4+CD11ahiCD49dhi cells that were CD44hiCD62L- were similar in MLN of infected Irf8-/- and B6 mice, but the proportions of CD4+GATA3+ and CD4+IL-4+ T cells were lower in infected Irf8-/- mice. CD11b+Gr1+ cells from naïve or infected Irf8-/- mice suppressed CD4+ T cell proliferation and parasite-specific IL-4 secretion in vitro albeit less efficiently than B6 mice. Surprisingly, there were significantly more CD4+ T cells in infected Irf8-/- mice, with a higher frequency of CD4+CD25+Foxp3+ T (Tregs cells and significantly higher numbers of Tregs than B6 mice. In vivo depletion of MDSC and/or Tregs in Irf8-/- mice did not affect adult worm burdens, but Treg depletion resulted in higher egg production and enhanced parasite-specific IL-5, IL-13, and IL-6 secretion ex vivo. Our data thus provide a previously

  1. Mast cell histamine promotes the immunoregulatory activity of myeloid-derived suppressor cells.

    Science.gov (United States)

    Martin, Rebecca K; Saleem, Sheinei J; Folgosa, Lauren; Zellner, Hannah B; Damle, Sheela R; Nguyen, Giang-Kim T; Ryan, John J; Bear, Harry D; Irani, Anne-Marie; Conrad, Daniel H

    2014-07-01

    It has been shown recently that MCs are required for differential regulation of the immune response by granulocytic versus monocytic MDSCs. Granulocytic MDSCs promoted parasite clearance, whereas monocytic MDSCs enhanced tumor progression; both activities were abrogated in MC-deficient mice. Herein, we demonstrate that the lack of MCs also influences MDSC trafficking. Preferential trafficking to the liver was not seen in MC-deficient mice. In addition, evidence that the MC mediator histamine was important in MDSC trafficking and activation is also shown. MDSCs express HR1-3. Blockade of these receptors by HR1 or HR2 antagonists reversed the histamine enhancement of MDSC survival and proliferation observed in cell culture. In addition, histamine differentially influenced Arg1 and iNOS gene expression in MDSCs and greatly enhanced IL-4 and IL-13 message, especially in granulocytic MDSCs. Evidence that histamine influenced activity seen in vitro translated to in vivo when HR1 and HR2 antagonists blocked the effect of MDSCs on parasite expulsion and tumor metastasis. All of these data support the MDSC-mediated promotion of Th2 immunity, leading to the suggestion that allergic-prone individuals would have elevated MDSC levels. This was directly demonstrated by looking at the relative MDSC levels in allergic versus control patients. Monocytic MDSCs trended higher, whereas granulocytic MDSCs were increased significantly in allergic patients. Taken together, our studies indicate that MCs and MC-released histamine are critical for MDSC-mediated immune regulation, and this interaction should be taken into consideration for therapeutic interventions that target MDSCs. © 2014 Society for Leukocyte Biology.

  2. HMGB1 enhances immune suppression by facilitating the differentiation and suppressive activity of myeloid-derived suppressor cells.

    Science.gov (United States)

    Parker, Katherine H; Sinha, Pratima; Horn, Lucas A; Clements, Virginia K; Yang, Huan; Li, Jianhua; Tracey, Kevin J; Ostrand-Rosenberg, Suzanne

    2014-10-15

    Chronic inflammation often precedes malignant transformation and later drives tumor progression. Likewise, subversion of the immune system plays a role in tumor progression, with tumoral immune escape now well recognized as a crucial hallmark of cancer. Myeloid-derived suppressor cells (MDSC) are elevated in most individuals with cancer, where their accumulation and suppressive activity are driven by inflammation. Thus, MDSCs may define an element of the pathogenic inflammatory processes that drives immune escape. The secreted alarmin HMGB1 is a proinflammatory partner, inducer, and chaperone for many proinflammatory molecules that MDSCs develop. Therefore, in this study, we examined HMGB1 as a potential regulator of MDSCs. In murine tumor systems, HMGB1 was ubiquitous in the tumor microenvironment, activating the NF-κB signal transduction pathway in MDSCs and regulating their quantity and quality. We found that HMGB1 promotes the development of MDSCs from bone marrow progenitor cells, contributing to their ability to suppress antigen-driven activation of CD4(+) and CD8(+) T cells. Furthermore, HMGB1 increased MDSC-mediated production of IL-10, enhanced crosstalk between MDSCs and macrophages, and facilitated the ability of MDSCs to downregulate expression of the T-cell homing receptor L-selectin. Overall, our results revealed a pivotal role for HMGB1 in the development and cancerous contributions of MDSCs. ©2014 American Association for Cancer Research.

  3. High numbers of myeloid derived suppressor cells in peripheral blood and ascitic fluid of cirrhotic and HCC patients.

    Science.gov (United States)

    Elwan, Nadia; Salem, Mohamed Labib; Kobtan, Abdelrahman; El-Kalla, Ferial; Mansour, Loai; Yousef, Mohamed; Al-Sabbagh, Ashraf; Zidan, Abdel-Aziz A; Abd-Elsalam, Sherief

    2018-02-01

    Hepatocellular carcinoma (HCC) is the 3rd most common cause of cancer-related death worldwide. It has evolved different immune escape mechanisms, which might include emergence of lymphoid and myeloid regulatory cells. Aim of this work: To determine the numbers of Myeloid-derived suppressor cells (MDSCs) in peripheral blood and ascitic fluid in cirrhosis and HCC and their relation to IFN-γ and α-fetoprotein (α-FP). Sixty individuals were enrolled in this study; forty cirrhotic patients with ascites; twenty without HCC (Group I), and twenty with HCC (group II) as well as twenty healthy individuals as a control group (group III). The phenotype and numbers of MDSCs were analyzed in peripheral blood of all the individuals and ascitic fluid of the patients using flow cytometry. Intracellular IFN-γ and serum alfa-fetoprotein were measured. Significant increases in the relative and the mean number of peripheral blood MDSCs were found in the cirrhosis and HCC groups than in the control group, with the HCC group showing the highest number. MDSC count was negatively correlated with IFN-γ levels, while α-FP was positively correlated with MDSC% in the HCC group. MDSC count was low in ascitic fluid of both HCC and cirrhosis groups with no significant difference between the 2 groups. A high frequency of MDSCs was detected in the peripheral blood of cirrhotic and HCC patients, indicating presence of immunosuppressive arms. These cells could be targeted to develop a new effective immunotherapy or an adjuvant to current therapies.

  4. Protection against HPV-16-Associated Tumors Requires the Activation of CD8+ Effector Memory T Cells and the Control of Myeloid-Derived Suppressor Cells.

    Science.gov (United States)

    Diniz, Mariana O; Sales, Natiely S; Silva, Jamile R; Ferreira, Luís Carlos S

    2016-08-01

    Active anticancer immunotherapeutic approaches have been shown to induce cellular or humoral immune responses in patients, but, thus far, the observed outcomes did not ensure their recommendation for clinical use. The induction of tumor-specific CD8(+) T cells, although required for the clearance of most solid tumors, was shown to be insufficient for the development of a successful immunotherapeutic approach. The suppressive immune environment triggered by tumors, including the expansion of myeloid-derived suppressor cells (MDSC), is detrimental to the development of antitumor immune responses and precludes the generation of more promising clinical outcomes. In this work, we characterized the CD8(+) T-cell population specifically involved in the control of tumor growth and the role of MDSCs after administration of an antitumor therapeutic DNA vaccine targeting human papillomavirus type 16 (HPV-16)-associated tumors. Activation of cytotoxic high-avidity CD8(+) T cells with an effector memory phenotype was found in mice grafted with tumor cells expressing the HPV-16 oncoproteins. In addition, MDSC antibody depletion further enhanced the immunotherapeutic effects of the vaccine, resulting in the complete eradication of tumor cells. Collectively, the current results indicate that the simultaneous control of MDSCs and activation of high-avidity tumor-specific effector memory CD8(+) T cells are key features for tumor protection by immunotherapeutic approaches and deserve further testing under clinical conditions. Mol Cancer Ther; 15(8); 1920-30. ©2016 AACR. ©2016 American Association for Cancer Research.

  5. Myeloid-Derived Suppressor Cells Ameliorate Cyclosporine A-Induced Hypertension in Mice.

    Science.gov (United States)

    Chiasson, Valorie L; Bounds, Kelsey R; Chatterjee, Piyali; Manandhar, Lochana; Pakanati, Abhinandan R; Hernandez, Marcos; Aziz, Bilal; Mitchell, Brett M

    2018-01-01

    The calcineurin inhibitor cyclosporine A (CsA) suppresses the immune system but promotes hypertension, vascular dysfunction, and renal damage. CsA decreases regulatory T cells and this contributes to the development of hypertension. However, CsA's effects on another important regulatory immune cell subset, myeloid-derived suppressor cells (MDSCs), is unknown. We hypothesized that augmenting MDSCs would ameliorate the CsA-induced hypertension and vascular and renal injury and dysfunction and that CsA reduces MDSCs in mice. Daily interleukin-33 treatment, which increased MDSC levels, completely prevented CsA-induced hypertension and vascular and renal toxicity. Adoptive transfer of MDSCs from control mice into CsA-treated mice after hypertension was established dose-dependently reduced blood pressure and vascular and glomerular injury. CsA treatment of aortas and kidneys isolated from control mice for 24 hours decreased relaxation responses and increased inflammation, respectively, and these effects were prevented by the presence of MDSCs. MDSCs also prevented the CsA-induced increase in fibronectin in microvascular and glomerular endothelial cells. Last, CsA dose-dependently reduced the number of MDSCs by inhibiting calcineurin and preventing cell proliferation, as other direct calcineurin signaling pathway inhibitors had the same dose-dependent effect. These data suggest that augmenting MDSCs can reduce the cardiovascular and renal toxicity and hypertension caused by CsA. © 2017 American Heart Association, Inc.

  6. Myeloid-derived suppressor cells in murine AIDS inhibit B-cell responses in part via soluble mediators including reactive oxygen and nitrogen species, and TGF-β.

    Science.gov (United States)

    Rastad, Jessica L; Green, William R

    2016-12-01

    Monocytic myeloid-derived suppressor cells (M-MDSCs) were increased during LP-BM5 retroviral infection, and were capable of suppressing not only T-cell, but also B-cell responses. In addition to previously demonstrating iNOS- and VISTA-dependent M-MDSC mechanisms, in this paper, we detail how M-MDSCs utilized soluble mediators, including the reactive oxygen and nitrogen species superoxide, peroxynitrite, and nitric oxide, and TGF-β, to suppress B cells in a predominantly contact-independent manner. Suppression was independent of cysteine-depletion and hydrogen peroxide production. When two major mechanisms of suppression (iNOS and VISTA) were eliminated in double knockout mice, M-MDSCs from LP-BM5-infected mice were able to compensate using other, soluble mechanisms in order to maintain suppression of B cells. The IL-10 producing regulatory B-cell compartment was among the targets of M-MDSC-mediated suppression. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Myeloid-derived suppressor cell-like fibrocytes are increased and associated with preserved lung function in chronic obstructive pulmonary disease.

    Science.gov (United States)

    Wright, A K A; Newby, C; Hartley, R A; Mistry, V; Gupta, S; Berair, R; Roach, K M; Saunders, R; Thornton, T; Shelley, M; Edwards, K; Barker, B; Brightling, C E

    2017-04-01

    The role of fibrocytes in chronic obstructive pulmonary disease (COPD) is unknown. We sought to enumerate blood and tissue fibrocytes in COPD and determine the association of blood fibrocytes with clinical features of disease. Utilizing flow cytometry to identify circulating, collagen type 1 + cells, we found two populations: (i) CD45 + CD34 + (fibrocytes) and (ii) CD45 + CD34 - [myeloid-derived suppressor cell (MDSC)-like fibrocytes] cells in stable COPD (n = 41) and control (n = 29) subjects. Lung resection material from a separate group of subjects with (n = 11) or without (n = 11) COPD was collected for tissue fibrocyte detection. We examined circulating fibrocyte populations for correlations with clinical parameters including quantitative computed tomography (qCT) and determined pathways of association between correlated variables using a path analysis model. Blood and tissue fibrocytes were not increased compared to control subjects nor were blood fibrocytes associated with lung function or qCT, but were increased in eosinophilic COPD. Myeloid-derived suppressor cell-like fibrocytes were increased in COPD compared to controls [2.3 (1.1-4.9), P = 0.038]. Our path analysis model showed that collagen type 1 intensity for MDSC-like fibrocytes was positively associated with lung function through associations with air trapping, predominately in the upper lobes. We have demonstrated that two circulating populations of fibrocyte exist in COPD, with distinct clinical associations, but are not prevalent in proximal or small airway tissue. Blood MDSC-like fibrocytes, however, are increased and associated with preserved lung function through a small airway-dependent mechanism in COPD. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Myeloid-Derived Suppressor Cells in the Tumor Microenvironment: Current Knowledge and Future Perspectives.

    Science.gov (United States)

    Ibáñez-Vea, Maria; Zuazo, Miren; Gato, Maria; Arasanz, Hugo; Fernández-Hinojal, Gonzalo; Escors, David; Kochan, Grazyna

    2018-04-01

    The current knowledge on tumor-infiltrating myeloid-derived suppressor cells (MDSCs) is based mainly on the extensive work performed in murine models. Data obtained for human counterparts are generated on the basis of tumor analysis from patient samples. Both sources of information led to determination of the main suppressive mechanisms used by these cell subsets in tumor-bearing hosts. As a result of the identification of protein targets responsible for MDSCs suppressive activity, different therapeutics agents have been used to eliminate/reduce their adverse effect. In the present work, we review the current knowledge on suppressive mechanisms of MDSCs and therapeutic treatments that interfere with their differentiation, expansion or activity. Based on the accumulation of new evidences supporting their importance for tumor progression and metastasis, the interest in these cell types is increasing. We revise the methods of MDSC generation/differentiation ex vivo that may help in overcoming problems associated with limited numbers of cells available from animals and patients for their study.

  9. Immunosuppressive activity enhances central carbon metabolism and bioenergetics in myeloid-derived suppressor cells in vitro models

    Directory of Open Access Journals (Sweden)

    Hammami Ines

    2012-07-01

    Full Text Available Abstract Background The tumor microenvironment contains a vast array of pro- and anti-inflammatory cytokines that alter myelopoiesis and lead to the maturation of immunosuppressive cells known as myeloid-derived suppressor cells (MDSCs. Incubating bone marrow (BM precursors with a combination of granulocyte-macrophage colony-stimulating factor (GM-CSF and interleukin-6 (IL-6 generated a tumor-infiltrating MDSC-like population that impaired anti-tumor specific T-cell functions. This in vitro experimental approach was used to simulate MDSC maturation, and the cellular metabolic response was then monitored. A complementary experimental model that inhibited L-arginine (L-Arg metabolizing enzymes in MSC-1 cells, an immortalized cell line derived from primary MDSCs, was used to study the metabolic events related to immunosuppression. Results Exposure of BM cells to GM-CSF and IL-6 activated, within 24 h, L-Arg metabolizing enzymes which are responsible for the MDSCs immunosuppressive potential. This was accompanied by an increased uptake of L-glutamine (L-Gln and glucose, the latter being metabolized by anaerobic glycolysis. The up-regulation of nutrient uptake lead to the accumulation of TCA cycle intermediates and lactate as well as the endogenous synthesis of L-Arg and the production of energy-rich nucleotides. Moreover, inhibition of L-Arg metabolism in MSC-1 cells down-regulated central carbon metabolism activity, including glycolysis, glutaminolysis and TCA cycle activity, and led to a deterioration of cell bioenergetic status. The simultaneous increase of cell specific concentrations of ATP and a decrease in ATP-to-ADP ratio in BM-derived MDSCs suggested cells were metabolically active during maturation. Moreover, AMP-activated protein kinase (AMPK was activated during MDSC maturation in GM-CSF and IL-6–treated cultures, as revealed by the continuous increase of AMP-to-ATP ratios and the phosphorylation of AMPK. Likewise, AMPK activity was

  10. ATP/P2X7 axis modulates myeloid-derived suppressor cell functions in neuroblastoma microenvironment.

    Science.gov (United States)

    Bianchi, G; Vuerich, M; Pellegatti, P; Marimpietri, D; Emionite, L; Marigo, I; Bronte, V; Di Virgilio, F; Pistoia, V; Raffaghello, L

    2014-03-20

    Tumor microenvironment of solid tumors is characterized by a strikingly high concentration of adenosine and ATP. Physiological significance of this biochemical feature is unknown, but it has been suggested that it may affect infiltrating immune cell responses and tumor progression. There is increasing awareness that many of the effects of extracellular ATP on tumor and inflammatory cells are mediated by the P2X7 receptor (P2X7R). Aim of this study was to investigate whether: (i) extracellular ATP is a component of neuroblastoma (NB) microenvironment, (ii) myeloid-derived suppressor cells (MDSCs) express functional P2X7R and (iii) the ATP/P2X7R axis modulates MDSC functions. Our results show that extracellular ATP was detected in NB microenvironment in amounts that increased in parallel with tumor progression. The percentage of CD11b(+)/Gr-1(+) cells was higher in NB-bearing mice compared with healthy animals. Within the CD11b/Gr-1(+) population, monocytic MDSCs (M-MDSCs) produced higher levels of reactive oxygen species (ROS), arginase-1 (ARG-1), transforming growth factor-β1 (TGF-β1) and stimulated more potently in vivo tumor growth, as compared with granulocytic MDSCs (G-MDSCs). P2X7R of M-MDSCs was localized at the plasma membrane, coupled to increased functionality, upregulation of ARG-1, TGF-β1 and ROS. Quite surprisingly, the P2X7R in primary MDSCs as well as in the MSC-1 and MSC-2 lines was uncoupled from cytotoxicity. This study describes a novel scenario in which MDSC immunosuppressive functions are modulated by the ATP-enriched tumor microenvironment.

  11. Increased level of both CD4+FOXP3+ regulatory T cells and CD14+HLA-DR⁻/low myeloid-derived suppressor cells and decreased level of dendritic cells in patients with multiple myeloma

    DEFF Research Database (Denmark)

    Brimnes, M K; Vangsted, Annette Juul; Knudsen, L M

    2010-01-01

    Patients with multiple myeloma (MM) suffer from a general impaired immunity comprising deficiencies in humoral responses, T-cell responses as well as dendritic cell (DC) function. Thus, to achieve control of tumour growth through immune therapy constitutes a challenge. Careful evaluation...... of the immune status in patients with MM seems crucial prior to active immune therapy. We evaluated the proportion of both, DC, Treg cells and myeloid-derived suppressor cells (MDSC) in peripheral blood from patients with MM at diagnosis and in remission as well as patients with monoclonal gammopathy......+FOXP3+ Treg cells was increased in patients at diagnosis and not in patients in remission or with MGUS. Also, Treg cells from patients with MM were functionally intact as they were able to inhibit proliferation of both CD4 and CD8 T cells. Finally, we observed an increase in the proportion of CD14+HLA...

  12. Glycolysis regulates the expansion of myeloid-derived suppressor cells in tumor-bearing hosts through prevention of ROS-mediated apoptosis

    Science.gov (United States)

    Jian, Shiou-Ling; Chen, Wei-Wei; Su, Yu-Chia; Su, Yu-Wen; Chuang, Tsung-Hsien; Hsu, Shu-Ching; Huang, Li-Rung

    2017-01-01

    Immunotherapy aiming to rescue or boost antitumor immunity is an emerging strategy for treatment of cancers. The efficacy of immunotherapy is strongly controlled by the immunological milieu of cancer patients. Myeloid-derived suppressor cells (MDSCs) are heterogeneous immature myeloid cell populations with immunosuppressive functions accumulating in individuals during tumor progression. The signaling mechanisms of MDSC activation have been well studied. However, there is little known about the metabolic status of MDSCs and the physiological role of their metabolic reprogramming. In this study, we discovered that myeloid cells upregulated their glycolytic genes when encountered with tumor-derived factors. MDSCs exhibited higher glycolytic rate than their normal cell compartment did, which contributed to the accumulation of the MDSCs in tumor-bearing hosts. Upregulation of glycolysis prevented excess reactive oxygen species (ROS) production by MDSCs, which protected MDSCs from apoptosis. Most importantly, we identified the glycolytic metabolite, phosphoenolpyruvate (PEP), as a vital antioxidant agent able to prevent excess ROS production and therefore contributed to the survival of MDSCs. These findings suggest that glycolytic metabolites have important roles in the modulation of fitness of MDSCs and could be potential targets for anti-MDSC strategy. Targeting MDSCs with analogs of specific glycolytic metabolites, for example, 2-phosphoglycerate or PEP may diminish the accumulation of MDSCs and reverse the immunosuppressive milieu in tumor-bearing individuals. PMID:28492541

  13. Tumor suppressors status in cancer cell line Encyclopedia.

    Science.gov (United States)

    Sonkin, Dmitriy; Hassan, Mehedi; Murphy, Denis J; Tatarinova, Tatiana V

    2013-08-01

    Tumor suppressors play a major role in the etiology of human cancer, and typically achieve a tumor-promoting effect upon complete functional inactivation. Bi-allelic inactivation of tumor suppressors may occur through genetic mechanisms (such as loss of function mutation, copy number (CN) loss, or loss of heterozygosity (LOH)), epigenetic mechanisms (such as promoter methylation or histone modification), or a combination of the two. We report systematically derived status of 69 known or putative tumor suppressors, across 799 samples of the Cancer Cell Line Encyclopedia. In order to generate such resource we constructed a novel comprehensive computational framework for the assessment of tumor suppressor functional "status". This approach utilizes several orthogonal genomic data types, including mutation data, copy number, LOH and expression. Through correlation with additional data types (compound sensitivity and gene set activity) we show that this integrative method provides a more accurate assessment of tumor suppressor status than can be inferred by expression, copy number, or mutation alone. This approach has the potential for a more realistic assessment of tumor suppressor genes for both basic and translational oncology research. Copyright © 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  14. Vasoactive intestinal peptide induces CD14+HLA-DR‑/low myeloid-derived suppressor cells in gastric cancer.

    Science.gov (United States)

    Li, Gang; Wu, Ke; Tao, Kaixiong; Lu, Xiaoming; Ma, Jianhua; Mao, Zhengqiang; Li, Hang; Shi, Liang; Li, Jing; Niu, Yanfeng; Xiang, Fan; Wang, Guobin

    2015-07-01

    Myeloid-derived suppressor cells (MDSCs) are a heterogeneous group of cells, which have been revealed to inhibit T-cell responses in tumor-bearing mice. In addition, a number of immune suppressive mechanisms have linked MDSCs and the development of human cancer. However, the role of MDSCs in human gastric cancer tissue remains to be elucidated as specific markers are lacking. Therefore, the aim of the present study was to investigate the frequency and immune suppressive function of MDSCs denoted in the present study as cluster of differentiation 14 (CD14)+human leukocyte antigen (HLA)-DR-/low in gastric cancer patients. In the present study, MDSCs were directly isolated and characterized from the tumor and adjacent normal tissue of gastric cancer patients. Functional analysis of the CD14+HLA-DR-/low MDSCs co-cultured with allogeneic CD4+ T cells were performed and compared with controls. In addition, the interferon-γ (IFN-γ) and interleukin (IL)-2 production was compared in order to investigate the capacity of vasoactive intestinal peptide (VIP) to induce CD14+HLA-DR(-/low) MDSC-mediated CD4+ T-cell dysfunction and whether IL-10 secretion is involved in this mechanism. As a result, the quantity of CD14+HLA-DR(-/low) cells in tumor tissue from gastric cancer patients was significantly higher than that in the adjacent normal tissue. In addition, CD14+HLA-DR-/low MDSCs isolated from tumor tissue were observed to inhibit the CD4+ T-cells' immune responses in comparison with those from the adjacent normal tissue. Furthermore, VIP was able to induce the differentiation of CD14+ mononuclear cells isolated from healthy donor peripheral blood mononuclear cells into activated MDSC cells. Of note, the immunosuppressive effect of VIP-induced CD14+HLA-DR(-/low) MDSCs on CD4+ T cells was mediated by IL-10 secretion, which was demonstrated in the subsequent decrease of IFN-γ and IL-2 production. In conclusion, CD14+HLA-DR(-/low) cells were significantly increased in gastric

  15. Suppressor cell function is preserved in pemphigus and pemphigoid

    Energy Technology Data Exchange (ETDEWEB)

    King, A.J.; Schwartz, S.A.; Lopatin, D.; Voorhees, J.J.; Diaz, L.A.

    1982-09-01

    Human peripheral blood lymphocytes (PBL) are activated to become suppressor T cells (S-T-C) by incubation with Concanavalin-A (Con-A). This has become the standard method for evaluation of suppressor function in patients. S-T-C function has been found to be impaired in several autoimmune diseases, including systemic lupus erythematosus (SLE). Using this assay, we have investigated suppressor-cell function in 2 autoimmune disorders, bullous pemphigoid (BP) and pemphigus vulgaris (PV), studying 6 patients from each group. Three patients with active SLE (positive controls), and 11 normal donors (negative controls) were also included. None of these patients had received systemic therapy with the exception of 2 patients with PV who were treated with gold in the past. PBL from these patients were incubated with and without 40 micrograms/ml Con-A for 72 hr to generate suppressor cells. Both groups of PBL were then irradiated wih 1500 r cobalt. Co-cultures were set up in sextuplicate using normal PBL as responders. Responder PBL were stimulated with 0.5, 1.0, and 2.0 micrograms/ml of phytohemagglutin (PHA) and 5.0, 10.0, and 20.0 micrograms/ml of Con-A. Cultures were pulsed on day 3 with /sup 3/H-thymidine and harvested on day 4. Data were analyzed using Student's t-test. S-T-C function was found to be significantly impaired in SLE vs normal (p . 0.0316). No statistically significant difference was seen in BP (p . 0.5883) and PV (p . 0.0921) as compared with normals. A defect in suppressor cell function may still be present in patients with PV and BP for the defect may be antigen-specific and therefore remain undetected by the Con-A suppressor assay.

  16. Suppressor cell function is preserved in pemphigus and pemphigoid

    International Nuclear Information System (INIS)

    King, A.J.; Schwartz, S.A.; Lopatin, D.; Voorhees, J.J.; Diaz, L.A.

    1982-01-01

    Human peripheral blood lymphocytes (PBL) are activated to become suppressor T cells (S-T-C) by incubation with Concanavalin-A (Con-A). This has become the standard method for evaluation of suppressor function in patients. S-T-C function has been found to be impaired in several autoimmune diseases, including systemic lupus erythematosus (SLE). Using this assay, we have investigated suppressor-cell function in 2 autoimmune disorders, bullous pemphigoid (BP) and pemphigus vulgaris (PV), studying 6 patients from each group. Three patients with active SLE (positive controls), and 11 normal donors (negative controls) were also included. None of these patients had received systemic therapy with the exception of 2 patients with PV who were treated with gold in the past. PBL from these patients were incubated with and without 40 micrograms/ml Con-A for 72 hr to generate suppressor cells. Both groups of PBL were then irradiated wih 1500 r cobalt. Co-cultures were set up in sextuplicate using normal PBL as responders. Responder PBL were stimulated with 0.5, 1.0, and 2.0 micrograms/ml of phytohemagglutin (PHA) and 5.0, 10.0, and 20.0 micrograms/ml of Con-A. Cultures were pulsed on day 3 with 3 H-thymidine and harvested on day 4. Data were analyzed using Student's t-test. S-T-C function was found to be significantly impaired in SLE vs normal (p . 0.0316). No statistically significant difference was seen in BP (p . 0.5883) and PV (p . 0.0921) as compared with normals. A defect in suppressor cell function may still be present in patients with PV and BP for the defect may be antigen-specific and therefore remain undetected by the Con-A suppressor assay

  17. Identification of myeloid derived suppressor cells in the peripheral blood of tumor bearing dogs.

    Science.gov (United States)

    Sherger, Matthew; Kisseberth, William; London, Cheryl; Olivo-Marston, Susan; Papenfuss, Tracey L

    2012-10-31

    Myeloid derived suppressor cells (MDSCs) are a recently described population of immune cells that significantly contribute to the immunosuppression seen in cancer patients. MDSCs are one of the most important factors that limit the efficacy of cancer immunotherapy (e.g. cancer vaccines) and MDSC levels are increased in cancer in multiple species. Identifying and targeting MDSCs is actively being investigated in the field of human oncology and is increasingly being investigated in veterinary oncology. The treatment of canine cancer not only benefits dogs, but is being used for translational studies evaluating and modifying candidate therapies for use in humans. Thus, it is necessary to understand the immune alterations seen in canine cancer patients which, to date, have been relatively limited. This study investigates the use of commercially available canine antibodies to detect an immunosuppressive (CD11b low/CADO48 low) cell population that is increased in the peripheral blood of tumor-bearing dogs. Commercially available canine antibodies CD11b and CADO48A were used to evaluate white blood cells from the peripheral blood cells of forty healthy control dogs and forty untreated, tumor-bearing dogs. Tumor-bearing dogs had a statistically significant increase in CD11b low/CADO48A low cells (7.9%) as compared to the control dogs (3.6%). Additionally, sorted CD11b low/CADO48A low generated in vitro suppressed the proliferation of canine lymphocytes. The purpose of this study was aimed at identifying potential canine specific markers for identifying MDSCs in the peripheral blood circulation of dogs. This study demonstrates an increase in a unique CD11b low/CADO48A low cell population in tumor-bearing dogs. This immunophenotype is consistent with described phenotypes of MDSCs in other species (i.e. mice) and utilizes commercially available canine-specific antibodies. Importantly, CD11b low/CADO48A low from a tumor environment suppress the proliferation of lymphocytes

  18. Novel Therapeutic Approaches Targeting MDSC in Myelodysplastic Syndrome

    Science.gov (United States)

    2017-09-01

    c) HL60 cells were treated with either DMSO, 20 µM of the anti-inflammatory compound ICT for 4 days prior to addition of BI 836858 (2 µg/ml) or...cells we pretreated HL60 with ICT , a compound that reduces MDSC and the S100A9/ CD33 axis,37 and show that pretreatment with ICT reduced the ...Public Release; Distribution Unlimited The views, opinions and/or findings contained in this report are those of the author(s) and should not be

  19. Mathematical modeling of tumor-induced immunosuppression by myeloid-derived suppressor cells: Implications for therapeutic targeting strategies.

    Science.gov (United States)

    Shariatpanahi, Seyed Peyman; Shariatpanahi, Seyed Pooya; Madjidzadeh, Keivan; Hassan, Moustapha; Abedi-Valugerdi, Manuchehr

    2018-04-07

    Myeloid-derived suppressor cells (MDSCs) belong to immature myeloid cells that are generated and accumulated during the tumor development. MDSCs strongly suppress the anti-tumor immunity and provide conditions for tumor progression and metastasis. In this study, we present a mathematical model based on ordinary differential equations (ODE) to describe tumor-induced immunosuppression caused by MDSCs. The model consists of four equations and incorporates tumor cells, cytotoxic T cells (CTLs), natural killer (NK) cells and MDSCs. We also provide simulation models that evaluate or predict the effects of anti-MDSC drugs (e.g., l-arginine and 5-Fluorouracil (5-FU)) on the tumor growth and the restoration of anti-tumor immunity. The simulated results obtained using our model were in good agreement with the corresponding experimental findings on the expansion of splenic MDSCs, immunosuppressive effects of these cells at the tumor site and effectiveness of l-arginine and 5-FU on the re-establishment of antitumor immunity. Regarding this latter issue, our predictive simulation results demonstrated that intermittent therapy with low-dose 5-FU alone could eradicate the tumors irrespective of their origins and types. Furthermore, at the time of tumor eradication, the number of CTLs prevailed over that of cancer cells and the number of splenic MDSCs returned to the normal levels. Finally, our predictive simulation results also showed that the addition of l-arginine supplementation to the intermittent 5-FU therapy reduced the time of the tumor eradication and the number of iterations for 5-FU treatment. Thus, the present mathematical model provides important implications for designing new therapeutic strategies that aim to restore antitumor immunity by targeting MDSCs. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Myeloid-Derived Suppressor Cells Associated With Disease Progression in Primary HIV Infection: PD-L1 Blockade Attenuates Inhibition.

    Science.gov (United States)

    Zhang, Zi-Ning; Yi, Nan; Zhang, Tong-Wei; Zhang, Le-Le; Wu, Xian; Liu, Mei; Fu, Ya-Jing; He, Si-Jia; Jiang, Yong-Jun; Ding, Hai-Bo; Chu, Zhen-Xing; Shang, Hong

    2017-10-01

    Events occurring during the initial phase of human immunodeficiency virus (HIV) infection are intriguing because of their dramatic impact on the subsequent course of the disease. In particular, the relationship between myeloid-derived suppressor cells (MDSCs) and HIV pathogenesis in primary infection remains unknown and the mechanism of MDSCs in HIV infection are incompletely defined. The frequency of MDSC expression in patients with primary HIV infection (PHI) and chronic HIV infection was measured, and the association with disease progression was studied. Programmed death-ligand 1 (PD-L1) and galectin-9 (Gal-9) expression on MDSCs was measured and in vitro blocking experiments were performed to study the role of PD-L1 in MDSCs' inhibition. We found increased levels of HLA-DRCD14CD33CD11b granulocytic(G)-MDSCs in PHI individuals compared with normal controls, which correlated with viral loads and was negatively related to CD4 T-cell levels. When cocultured with purified G-MDSCs, both proliferation and interferon-γ secretion by T cell receptor (TCR)-stimulated CD8 T cells from HIV-infected patients were significantly inhibited. We also demonstrated that PD-L1, but not Gal-9, expression on HLA-DRCD14CD33CD11b cells increased during HIV infection. The suppressive activity of G-MDSCs from HIV-infected patients was attenuated by PD-L1 blockade. We found a significant increase in G-MDSCs in PHI patients that was related to disease progression and PD-L1 was used by MDSCs to inhibit CD8 T cells in HIV infection. Our data improve the understanding of HIV pathogenesis in PHI.

  1. Splenectomy inhibits non-small cell lung cancer growth by modulating anti-tumor adaptive and innate immune response

    Science.gov (United States)

    Levy, Liran; Mishalian, Inbal; Bayuch, Rachel; Zolotarov, Lida; Michaeli, Janna; Fridlender, Zvi G

    2015-01-01

    It has been shown that inhibitors of the immune system reside in the spleen and inhibit the endogenous antitumor effects of the immune system. We hypothesized that splenectomy would inhibit the growth of relatively large non-small lung cancer (NSCLC) tumors by modulating the systemic inhibition of the immune system, and in particular Myeloid Derived Suppressor Cells (MDSC). The effect of splenectomy was evaluated in several murine lung cancer models. We found that splenectomy reduces tumor growth and the development of lung metastases, but only in advanced tumors. In immune-deficient NOD-SCID mice the effect of splenectomy on tumor growth and metastatic spread disappeared. Splenectomy significantly reduced the presence of MDSC, and especially monocytic-MDSC in the circulation and inside the tumor. Specific reduction of the CCR2+ subset of monocytic MDSC was demonstrated, and the importance of the CCL2-CCR2 axis was further shown by a marked reduction in CCL2 following splenectomy. These changes were followed by changes in the macrophages contents of the tumors to become more antitumorigenic, and by increased activation of CD8+ Cytotoxic T-cells (CTL). By MDSC depletion, and adoptive transfer of MDSCs, we demonstrated that the effect of splenectomy on tumor growth was substantially mediated by MDSC cells. We conclude that the spleen is an important contributor to tumor growth and metastases, and that splenectomy can blunt this effect by depletion of MDSC, changing the amount and characteristics of myeloid cells and enhancing activation of CTL. PMID:26137413

  2. Tumor-derived exosomes induce CD8+T cell suppressors.

    Science.gov (United States)

    Maybruck, Brian T; Pfannenstiel, Lukas W; Diaz-Montero, Marcela; Gastman, Brian R

    2017-08-15

    The suppressive nature of immune cells in the tumor microenvironment plays a major role in regulating anti-tumor immune responses. Our previous work demonstrated that a soluble factor from tumor cells is able to induce a suppressor phenotype (SP) in human CD8 + T cells typified by loss of CD27/CD28 expression and acquisition of a potent suppressor function. The present study hypothesized that the soluble mechanism that is inducing the SP in CD8 + T cells are tumor-derived exosomes (TDEs). Membrane vesicles and TDEs from multiple head and neck cancer cell line's conditioned growth media were isolated by ultracentrifugation and precipitation, respectively. Human purified CD3 + CD8 + T cells were assessed for their induction of the T cell SP by flow cytometry identifying loss of CD27/CD28 expression and in vitro suppression assays. Furthermore, the T cell SP was characterized for the attenuation of IFN-γ production. To delineate exosomal proteins contributing to T cell SP, mass spectrometry was used to identify unique proteins that were present in TDEs. CRISPR/Cas9 knockout constructs were used to examine the role of one of these proteins, galectin-1. To assess the role of exosomal RNA, RNA purified from TDEs was nucleofected into CD8 + T cells followed by suppression analysis. Using fractionated conditioned growth media, factors >200 kDa induced CD8 + T cell SP, which was determined to be an exosome by mass spectrometry analysis. Multiple head and neck cancer-derived cell lines were found to secrete T cell SP-inducing exosomes. Mass spectrometry analysis revealed that an immunoregulatory protein, galectin-1 (Gal-1), was expressed in those exosomes, but not in TDEs unable to induce T cell SP. Galectin-1 knockout cells were found to be less able to induce T cell SP. Furthermore, RNA purified from the T cell SP-inducing exosomes were found to partially induce the SP when transfected into normal CD8 + T cells. For the first-time, TDEs have been identified to induce a

  3. Early Expansion of Circulating Granulocytic Myeloid-derived Suppressor Cells Predicts Development of Nosocomial Infections in Patients with Sepsis.

    Science.gov (United States)

    Uhel, Fabrice; Azzaoui, Imane; Grégoire, Murielle; Pangault, Céline; Dulong, Joelle; Tadié, Jean-Marc; Gacouin, Arnaud; Camus, Christophe; Cynober, Luc; Fest, Thierry; Le Tulzo, Yves; Roussel, Mikael; Tarte, Karin

    2017-08-01

    Sepsis induces a sustained immune dysfunction responsible for poor outcome and nosocomial infections. Myeloid-derived suppressor cells (MDSCs) described in cancer and inflammatory processes may be involved in sepsis-induced immune suppression, but their clinical impact remains poorly defined. To clarify phenotype, suppressive activity, origin, and clinical impact of MDSCs in patients with sepsis. Peripheral blood transcriptomic analysis was performed on 29 patients with sepsis and 15 healthy donors. A second cohort of 94 consecutive patients with sepsis, 11 severity-matched intensive care patients, and 67 healthy donors was prospectively enrolled for flow cytometry and functional experiments. Genes involved in MDSC suppressive functions, including S100A12, S100A9, MMP8, and ARG1, were up-regulated in the peripheral blood of patients with sepsis. CD14 pos HLA-DR low/neg monocytic (M)-MDSCs were expanded in intensive care unit patients with and without sepsis and CD14 neg CD15 pos low-density granulocytes/granulocytic (G)-MDSCs were more specifically expanded in patients with sepsis (P sepsis. G-MDSCs, made of immature and mature granulocytes expressing high levels of degranulation markers, were specifically responsible for arginase 1 activity. High initial levels of G-MDSCs, arginase 1, and S100A12 but not M-MDSCs were associated with subsequent occurrence of nosocomial infections. M-MDSCs and G-MDSCs strongly contribute to T-cell dysfunction in patients with sepsis. More specifically, G-MDSCs producing arginase 1 are associated with a higher incidence of nosocomial infections and seem to be major actors of sepsis-induced immune suppression.

  4. Nonspecific suppressor T cells cause decreased mixed lymphocyte culture reactivity in bone marrow transplant patients

    Energy Technology Data Exchange (ETDEWEB)

    Harada, M.; Ueda, M.; Nakao, S.; Kondo, K.; Odaka, K.; Shiobara, S.; Matsue, K.; Mori, T.; Matsuda, T.

    1986-07-15

    Decreased reactivity in mixed lymphocyte culture (MLC) was observed in patients within 1 yr after allogeneic and autologous bone marrow transplantation. Suppressor activity of peripheral blood mononuclear cells (PBMC) from transplant patients was studied by adding these cells as modulator cells to a bidirectional MLC with cells from normal individuals. PBMC from transplant patients markedly suppressed MLC reactivity in a dose-dependent manner. Suppressor activity was present in cells forming rosettes with sheep erythrocytes. Treatment of modulator cells with monoclonal antibodies against T cell differentiation antigens (OKT8, OKIa1) and complement completely abolished suppression of MLC. Suppressor activity was unaffected by 30 Gy irradiation. Suppressor activity declined gradually after transplantation and was inversely correlated with MLC reactivity of each patient at a significant level (p less than 0.01). These observations suggest that OKT8+ Ia+ radioresistant suppressor T cells play a role in the development of decreased MLC reactivity observed during the early post-transplant period.

  5. Myeloid-Derived Suppressor Cells and Therapeutic Strategies in Cancer

    Directory of Open Access Journals (Sweden)

    Hiroshi Katoh

    2015-01-01

    Full Text Available Development of solid cancer depends on escape from host immunosurveillance. Various types of immune cells contribute to tumor-induced immune suppression, including tumor associated macrophages, regulatory T cells, type 2 NKT cells, and myeloid-derived suppressor cells (MDSCs. Growing body of evidences shows that MDSCs play pivotal roles among these immunosuppressive cells in multiple steps of cancer progression. MDSCs are immature myeloid cells that arise from myeloid progenitor cells and comprise a heterogeneous immune cell population. MDSCs are characterized by the ability to suppress both adaptive and innate immunities mainly through direct inhibition of the cytotoxic functions of T cells and NK cells. In clinical settings, the number of circulating MDSCs is associated with clinical stages and response to treatment in several cancers. Moreover, MDSCs are reported to contribute to chemoresistant phenotype. Collectively, targeting MDSCs could potentially provide a rationale for novel treatment strategies in cancer. This review summarizes recent understandings of MDSCs in cancer and discusses promissing clinical approaches in cancer patients.

  6. Deficiency of Kruppel-like factor KLF4 in mammary tumor cells inhibits tumor growth and pulmonary metastasis and is accompanied by compromised recruitment of myeloid-derived suppressor cells

    Science.gov (United States)

    Yu, Fang; Shi, Ying; Wang, Junfeng; Li, Juan; Fan, Daping; Ai, Walden

    2013-01-01

    Increasing evidence indicates that myeloid-derived suppressor cells (MDSCs) negatively regulate immune responses during tumor progression, inflammation and infection. However, the underlying molecular mechanisms of their development and mobilization remain to be fully delineated. Kruppel-like factor KLF4 is a transcription factor that has an oncogenic function in breast cancer development, but its function in tumor microenvironment, a critical component for tumorigenesis, has not been examined. By using a spontaneously metastatic 4T1 breast cancer mouse model and an immunodeficient NOD/SCID mouse model, we demonstrated that KLF4 knockdown delayed tumor development and inhibited pulmonary metastasis, which was accompanied by decreased accumulation of MDSCs in bone marrow, spleens and primary tumors. Mechanistically, we found that KLF4 knockdown resulted in a significant decrease of circulating GM-CSF, an important cytokine for MDSC biology. Consistently, recombinant GM-CSF restored the frequency of MDSCs in purified bone marrow cells incubated with conditioned medium from KLF4 deficient cells. In addition, we identified CXCL5 as a critical mediator to enhance the expression and function of GM-CSF. Reduced CXCL5 expression by KLF4 knockdown in primary tumors and breast cancer cells was correlated with a decreased GM-CSF expression in our mouse models. Finally, we found that CXCL5/CXCR2 axis facilitated MDSC migration and that anti-GM-CSF antibodies neutralized CXCL5-induced accumulation of MDSCs. Taken together, our data suggest that KLF4 modulates maintenance of MDSCs in bone marrow by inducing GM-CSF production via CXCL5 and regulates recruitment of MDSCs into the primary tumors through the CXCL5/CXCR2 axis, both of which contribute to KLF4-mediated mammary tumor development. PMID:23737434

  7. Soluble suppressor supernatants elaborated by concanavalin A-activated human mononuclear cells. Characterization of a soluble suppressor of B cell immunoglobulin production

    International Nuclear Information System (INIS)

    Fleisher, T.A.; Greene, W.C.; Blaese, R.M.; Waldmann, T.A.

    1981-01-01

    Human peripheral blood mononuclear cells (PBMC) activated with the mitogenic lectin concanavalin A (Con A) elaborate a soluble immune suppressor supernatant (SISS) that contains at least 2 distinct suppressor factors. One of these, SISS-B, inhibits polyclonal B cell immunoglobulin production, whereas the other, SISS-T, suppresses T cell proliferation to both mitogens and antigens. The latter mediator is discussed in the companion paper. Characteristics of the human soluble suppressor of B cell immunoglobulin production (SISS-B) include: 1) inhibition by a noncytotoxic mechanism, 2) loss of activity in the presence of the monosaccharide L-rhamnose, 3) appearance within 8 to 16 hr after the addition of Con A, 4) elaboration by cells irradiated with 500 or 2000 rads, 5) production by highly purified T cells, 6) stability at pH 2.5 but instability at 56/sup o/C, and 7) m.w. of 60 to 80,000. These data indicate that after Con A activation, selected T cells not only become potent suppressor cells, but also generate a soluble saccharide-specific factor(s) that inhibits polyclonal immunoglobulin production by human B cells

  8. Regulatory role for the memory B cell as suppressor-inducer of feedback control

    International Nuclear Information System (INIS)

    Kennedy, M.W.; Thomas, D.B.

    1983-01-01

    A regulatory role is proposed for the antigen-responsive B cell, as suppressor-inducer of feedback control during the secondary response in vivo. In a double adoptive transfer of memory cells primed to a thymus-dependent antigen from one irradiated host to another, antigen-specific suppressors are generated after a critical time in the primary recipient, able to entirely ablate a secondary anti-hapten response. Positive cell selection in the fluorescence-activated cell sorter confirmed that suppression was mediated by an Lyt-2+ T cell; however, positively selected B cells were also inhibitory and able to induce suppressors in a carrier-specific manner: B hapten induced suppressors in a carrier-primed population, and B carrier induced suppressors in a hapten-carrier population. At the peak of the antibody response in the primary host, memory B cells and their progeny were unable to differentiate further to plasma cells due to their intrinsic suppressor-inducer activity, but this autoregulatory circuit could be severed by adoptive transfer to carrier-primed, X-irradiated recipients

  9. Suppressor cells in transplantation tolerance. III. The role of antigen in the maintenance of transplantation tolerance

    International Nuclear Information System (INIS)

    Tutschka, P.J.; Hess, A.D.; Beschorner, W.E.; Santos, G.W.

    1982-01-01

    Suppressor cells, which in an alloantigen-specific manner inhibit proliferation of donor cells to host antigens in a mixed lymphocyte culture and adoptively transfer the suppression of graft-versus-host disease (GVHD), undergo a gradual clonal reduction in long-term, allogeneic, histoincompatible rat radiation chimeras until they can no longer be measured in an in vitro suppressor cell assay. When lymphohematopoietic cells from these chimeras are transferred into lethally irradiated secondary recipients of original donor strain, the suppressor cells, now in a target antigen-free environment, undergo a further clonal reduction. After parking for 120 days, the chimeric cells are specifically tolerant to original host antigens, but cannot adoptively transfer suppression of GVHD. When chimeric cells, parked for 120 days in secondary recipients of original donor strain, are stimulated with original host-type antigen repeatedly during or once at the end of the parking period, the suppressor cell clone is expanded, suppressor cells can be identified in vitro, and suppression of GVHD can adoptively be transferred to tertiary recipients

  10. Novel Therapeutic Approaches Targeting MDSC in Myelodysplastic Syndrome

    Science.gov (United States)

    2016-09-01

    hematopoiesis and a propensity for progression to acute myeloid leukemia (AML). MDS are senescence-dependent myeloid malignancies with a rising prevalence owing...STATEMENT 13. SUPPLEMENTARY NOTES 14. ABSTRACT 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: a. REPORT b. ABSTRACT c. THIS PAGE 17. LIMITATION OF... myeloid -derived suppressor cells (MDSCs), a heterogeneous group of immature myeloid cells, which play a critical role in MDS pathogenesis. A key

  11. Clinical impact of the immunome in lymphoid malignancies: the role of Myeloid-Derived Suppressor Cells

    Directory of Open Access Journals (Sweden)

    Calogero eVetro

    2015-05-01

    Full Text Available The better definition of the mutual sustainment between neoplastic cells and immune system has been translated from the bench to the bedside acquiring value as prognostic factor. Additionally, it represents a promising tool for improving therapeutic strategies. In this context, myeloid-derived suppressor cells have gained a central role in tumor developing with consequent therapeutic implications. In this review, we will focus on the biological and clinical impact of the study of myeloid-derived suppressor cells in the settings of lymphoid malignancies.

  12. A highly efficient tumor-infiltrating MDSC differentiation system for discovery of anti-neoplastic targets, which circumvents the need for tumor establishment in mice.

    Science.gov (United States)

    Liechtenstein, Therese; Perez-Janices, Noemi; Gato, Maria; Caliendo, Fabio; Kochan, Grazyna; Blanco-Luquin, Idoia; Van der Jeught, Kevin; Arce, Frederick; Guerrero-Setas, David; Fernandez-Irigoyen, Joaquin; Santamaria, Enrique; Breckpot, Karine; Escors, David

    2014-09-15

    Myeloid-derived suppressor cells (MDSCs) exhibit potent immunosuppressive activities in cancer. MDSCs infiltrate tumors and strongly inhibit cancer-specific cytotoxic T cells. Their mechanism of differentiation and identification of MDSC-specific therapeutic targets are major areas of interest. We have devised a highly efficient and rapid method to produce very large numbers of melanoma-infiltrating MDSCs ex vivo without inducing tumors in mice. These MDSCs were used to study their differentiation, immunosuppressive activities and were compared to non-neoplastic counterparts and conventional dendritic cells using unbiased systems biology approaches. Differentially activated/deactivated pathways caused by cell type differences and by the melanoma tumor environment were identified. MDSCs increased the expression of trafficking receptors to sites of inflammation, endocytosis, changed lipid metabolism, and up-regulated detoxification pathways such as the expression of P450 reductase. These studies uncovered more than 60 potential novel therapeutic targets. As a proof of principle, we demonstrate that P450 reductase is the target of pro-drugs such as Paclitaxel, which depletes MDSCs following chemotherapy in animal models of melanoma and in human patients. Conversely, P450 reductase protects MDSCs against the cytotoxic actions of other chemotherapy drugs such as Irinotecan, which is ineffective for the treatment of melanoma.

  13. Identification of CD4+CD25+CD127-regulatory T cells and CD14+HLA-DR-/low myeloid-derived suppressor cells and their roles in the prognosis of breast cancer.

    Science.gov (United States)

    Wang, Jinhu; Yang, Jianhong

    2016-08-01

    The aim of the present study was to identify cluster of differentiation 4 + (CD4 + )CD25 + CD127 - regulatory T cells (Tregs) and CD14 + human leukocyte antigen-antigen D-related (HLA - DR - )/low myeloid-derived suppressor cells (MDSCs) in patients with breast cancer of varying stages, and investigate their roles and the potential interactions in the prognosis of breast cancer. A total of 40 patients with breast cancer were included in the study. A total of 30 healthy individuals served as the healthy control. Flow cytometry was performed for the identification of biomarkers. Natural Tregs were characterized by the expression of CD4 + CD25 + CD127 - . The MDSC frequency was expressed as the percentage of CD33 + CD11b + HLA - DR - lineage markers (Lin) - . The absolute number of Tregs was higher in breast cancer patients compared to the healthy control. The absolute number of Tregs in the patients with stage III or IV breast cancer was higher than those of the stage I or II, respectively. The percentage showed a gradual increase in the patients with breast cancer compared with the normal control. No direct correlation was established between the number or percentage of Tregs and the patient survival. There was a higher percentage of circulating MDSCs in breast cancer patients compared with the normal individuals. A close correlation was established between clinical cancer stage and percentage and total number of circulating MDSCs. To be exact, a significant increase of MDSC percentage and total number was observed in patients with stage III-IV breast cancer compared with the other cancer patients (stage I-II) and the normal individuals. No statistical difference was observed in the 3- and 5-year survival rates in the breast cancer patients with enhanced expression of Tregs, compared with the normal individuals. In conclusion, enhanced expression of CD4 + CD25 + CD127 - Tregs cells and CD33 + CD11 + HLA - DR - LIN - MDSCs were identified from patients with breast

  14. Mast cells down-regulate CD4+CD25+ T regulatory cell suppressor function via histamine H1 receptor interaction.

    Science.gov (United States)

    Forward, Nicholas A; Furlong, Suzanne J; Yang, Yongjun; Lin, Tong-Jun; Hoskin, David W

    2009-09-01

    Mast cells promote both innate and acquired immune responses, but little is known about the effect of mast cells on T regulatory (T(reg)) cell function. In this study, we show for the first time that the capacity of murine CD4(+)CD25(+) T(reg) cells to suppress in vitro proliferation by CD4(+)CD25(-) T responder (T(resp)) cells in response to anti-CD3/anti-CD28 mAb-coated beads was reduced in the presence of syngeneic bone marrow-derived mast cells (BMMC) activated by FcepsilonR cross-linking. Activated BMMC culture supernatants or exogenous histamine also inhibited T(reg) cell suppressor function while the histamine H1 receptor-specific antagonist loratadine, but not the H2 receptor-specific antagonist famotidine, restored T(reg) cell suppressor function in the presence of activated BMMC or activated BMMC culture supernatants. Moreover, treatment of T(reg) cells with loratadine, but not famotidine, rescued T(reg) cell suppressor function in the presence of exogenous histamine. In addition, the H1 receptor-specific agonist 2-pyridylethylamine dihydrochloride inhibited T(reg) cell suppressor function to an extent that was comparable to histamine, whereas the H2 receptor-specific agonist amthamine dihydrobromide was without effect. Both T(reg) cells and T(resp) cells expressed H1 receptors. Exposure to histamine caused T(reg) cells to express lower levels of CD25 and the T(reg) cell-specific transcription factor Foxp3. Taken together, these data indicate that BMMC-elaborated histamine inhibited T(reg) cell suppressor function by signaling through the H1 receptor. We suggest that histamine released as a result of mast cell activation by microbial products might cause a transient decrease in T(reg) cell suppressor function, thereby enhancing the development of protective immunity.

  15. An Immature Myeloid/Myeloid-Suppressor Cell Response Associated with Necrotizing Inflammation Mediates Lethal Pulmonary Tularemia.

    Directory of Open Access Journals (Sweden)

    Sivakumar Periasamy

    2016-03-01

    Full Text Available Inhalation of Francisella tularensis (Ft causes acute and fatal pneumonia. The lung cytokine milieu favors exponential Ft replication, but the mechanisms underlying acute pathogenesis and death remain unknown. Evaluation of the sequential and systemic host immune response in pulmonary tularemia reveals that in contrast to overwhelming bacterial burden or cytokine production, an overt innate cellular response to Ft drives tissue pathology and host mortality. Lethal infection with Ft elicits medullary and extra-medullary myelopoiesis supporting recruitment of large numbers of immature myeloid cells and MDSC to the lungs. These cells fail to mature and die, leading to subsequent necrotic lung damage, loss of pulmonary function, and host death that is partially dependent upon immature Ly6G+ cells. Acceleration of this process may account for the rapid lethality seen with Ft SchuS4. In contrast, during sub-lethal infection with Ft LVS the pulmonary cellular response is characterized by a predominance of mature neutrophils and monocytes required for protection, suggesting a required threshold for lethal bacterial infection. Further, eliciting a mature phagocyte response provides transient, but dramatic, innate protection against Ft SchuS4. This study reveals that the nature of the myeloid cell response may be the primary determinant of host mortality versus survival following Francisella infection.

  16. Nutrient restriction enhances the proliferative potential of cells lacking the tumor suppressor PTEN in mitotic tissues

    Science.gov (United States)

    Nowak, Katarzyna; Seisenbacher, Gerhard; Hafen, Ernst; Stocker, Hugo

    2013-01-01

    How single cells in a mitotic tissue progressively acquire hallmarks of cancer is poorly understood. We exploited mitotic recombination in developing Drosophila imaginal tissues to analyze the behavior of cells devoid of the tumor suppressor PTEN, a negative regulator of PI3K signaling, under varying nutritional conditions. Cells lacking PTEN strongly overproliferated specifically in nutrient restricted larvae. Although the PTEN mutant cells were sensitive to starvation, they successfully competed with neighboring cells by autonomous and non-autonomous mechanisms distinct from cell competition. The overgrowth was strictly dependent on the activity of the downstream components Akt/PKB and TORC1, and a reduction in amino acid uptake by reducing the levels of the amino acid transporter Slimfast caused clones of PTEN mutant cells to collapse. Our findings demonstrate how limiting nutritional conditions impact on cells lacking the tumor suppressor PTEN to cause hyperplastic overgrowth. DOI: http://dx.doi.org/10.7554/eLife.00380.001 PMID:23853709

  17. Identification of an MLC suppressor cell population in acute leukemia

    International Nuclear Information System (INIS)

    Bryan, C.F.; Broxmeyer, H.E.; Hansen, J.; Pollack, M.; Dupont, B.

    1978-01-01

    The MLC data from the 20 nonsuppressing patients and the 10 suppressing leukemia patients were analyzed with regard to HLA-A, -B, and -C antigens in the leukemia patients and compared with the presence or absence of suppression. These results demonstrate a significant increase (p < 0.02, Mann-Whitney U test) of HLA antigens Al, A3, and A11 in the leukemia suppressor group. Seven of the 10 leukemia patients showing suppression were A1, A3, or A11, while only 4 of the 20 nonsuppressing leukemia patients carried any of these three HLA-A antigens. The studies demonstrate that a nonspecific suppression of MLC responses is observed in 33% of the patients with acute leukemia

  18. Myeloid derived suppressor cells-An overview of combat strategies to increase immunotherapy efficacy

    NARCIS (Netherlands)

    Draghiciu, Oana; Lubbers, Joyce; Nijman, Hans W.; Daemen, Toos

    2015-01-01

    Myeloid-derived suppressor cells (MDSCs) contribute to tumor-mediated immune escape and negatively correlate with overall survival of cancer patients. Nowadays, a variety of methods to target MDSCs are being investigated. Based on the intervention stage of MDSCs, namely development, expansion and

  19. Metabolic activity is necessary for activation of T suppressor cells by B cells

    International Nuclear Information System (INIS)

    Elkins, K.L.; Stashak, P.W.; Baker, P.J.

    1990-01-01

    Ag-primed B cells must express cell-surface IgM, but not IgD or Ia Ag, and must remain metabolically active, in order to activate suppressor T cells (Ts) specific for type III pneumococcal polysaccharide. Ag-primed B cells that were gamma-irradiated with 1000r, or less, retained the ability to activate Ts; however, Ag-primed B cells exposed to UV light were not able to do so. gamma-Irradiated and UV-treated Ag-primed B cells both expressed comparable levels of cell-surface IgM, and both localized to the spleen after in vivo transfer; neither could proliferate in vitro in response to mitogens. By contrast, gamma-irradiated primed B cells were still able to synthesize proteins, whereas UV-treated primed B cells could not. These findings suggest that in order for Ag-primed B cells to activate Ts, they must (a) express cell-associated IgM (sIgM) antibody bearing the idiotypic determinants of antibody specific for type III pneumococcal polysaccharide, and (b) be able to synthesize protein for either the continued expression of sIgM after cell transfer, or for the elaboration of another protein molecule that is also required for the activation of Ts; this molecule does not appear to be Ia Ag

  20. Alloantigen-specific suppressor T cells are not inhibited by cyclosporin A, but do require IL 2 for activation

    International Nuclear Information System (INIS)

    Bucy, R.P.

    1986-01-01

    Alloantigen-specific suppressor T cells are activated from normal murine spleen cells in mixed lymphocyte reactions (MLR). These T cells are radioresistant and suppress the activation of cytotoxic T lymphocytes (CTL) in second primary MLR cultures. This report demonstrates that cyclosporin A (CsA) blocks the activation of these suppressor cells at a dose of 1 microgram/ml. However, reconstitution of CsA blocked cultures with IL 2 restores the activation of the suppressor T cells, but fails to significantly restore the activation of CTL in these same cultures. This differential activation requirement was used to establish T cell lines that demonstrate enriched suppressor cell activity but depletion of CTL activity. These findings are discussed in terms of the mechanism of action of CsA in these distinct T cell subsets and the relevance to models of allograft unresponsiveness

  1. CMTM5 exhibits tumor suppressor activity through promoter methylation in oral squamous cell carcinoma

    International Nuclear Information System (INIS)

    Zhang, Heyu; Nan, Xu; Li, Xuefen; Chen, Yan; Zhang, Jianyun; Sun, Lisha; Han, Wenlin; Li, Tiejun

    2014-01-01

    Highlights: • Down-regulation of CMTM5 expression in OSCC tissues was found. • The promoter methylation status of CMTM5 was measured. • CMTM5-v1 inhibited cell proliferation and migration and induced apoptosis. • CMTM5 might act as a putative tumor suppressor gene in OSCC. - Abstract: Oral squamous cell carcinoma (OSCC) is one of the most common types of malignancies in the head and neck region. CKLF-like MARVEL transmembrane domain-containing member 5 (CMTM5) has been recently implicated as a tumor suppressor gene in several cancer types. Herein, we examined the expression and function of CMTM5 in oral squamous cell carcinoma. CMTM5 was down-regulated in oral squamous cell lines and tumor samples from patients with promoter methylation. Treatment with the demethylating agent 5-aza-2′-deoxycytidine restored CMTM5 expression. In the OSCC cell lines CAL27 and GNM, the ectopic expression of CMTM5-v1 strongly inhibited cell proliferation and migration and induced apoptosis. In addition, CMTM5-v1 inhibited tumor formation in vivo. Therefore, CMTM5 might act as a putative tumor suppressor gene through promoter methylation in oral squamous cell carcinoma

  2. CMTM5 exhibits tumor suppressor activity through promoter methylation in oral squamous cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Heyu [Central Laboratory, Peking University School of Stomatology, Beijing (China); Nan, Xu [Center for Human Disease Genomics, Department of Immunology, Key Laboratory of Medical Immunology, Ministry of Health, School of Basic Medical Sciences, Peking University, Beijing (China); Li, Xuefen [Central Laboratory, Peking University School of Stomatology, Beijing (China); Chen, Yan; Zhang, Jianyun [Department of Oral Pathology, Peking University School of Stomatology, Beijing (China); Sun, Lisha [Central Laboratory, Peking University School of Stomatology, Beijing (China); Han, Wenlin [Center for Human Disease Genomics, Department of Immunology, Key Laboratory of Medical Immunology, Ministry of Health, School of Basic Medical Sciences, Peking University, Beijing (China); Li, Tiejun, E-mail: litiejun22@vip.sina.com [Department of Oral Pathology, Peking University School of Stomatology, Beijing (China)

    2014-05-02

    Highlights: • Down-regulation of CMTM5 expression in OSCC tissues was found. • The promoter methylation status of CMTM5 was measured. • CMTM5-v1 inhibited cell proliferation and migration and induced apoptosis. • CMTM5 might act as a putative tumor suppressor gene in OSCC. - Abstract: Oral squamous cell carcinoma (OSCC) is one of the most common types of malignancies in the head and neck region. CKLF-like MARVEL transmembrane domain-containing member 5 (CMTM5) has been recently implicated as a tumor suppressor gene in several cancer types. Herein, we examined the expression and function of CMTM5 in oral squamous cell carcinoma. CMTM5 was down-regulated in oral squamous cell lines and tumor samples from patients with promoter methylation. Treatment with the demethylating agent 5-aza-2′-deoxycytidine restored CMTM5 expression. In the OSCC cell lines CAL27 and GNM, the ectopic expression of CMTM5-v1 strongly inhibited cell proliferation and migration and induced apoptosis. In addition, CMTM5-v1 inhibited tumor formation in vivo. Therefore, CMTM5 might act as a putative tumor suppressor gene through promoter methylation in oral squamous cell carcinoma.

  3. Clinical Impact of the Immunome in Lymphoid Malignancies: The Role of Myeloid-Derived Suppressor Cells

    Science.gov (United States)

    Vetro, Calogero; Romano, Alessandra; Ancora, Flavia; Coppolino, Francesco; Brundo, Maria V.; Raccuia, Salvatore A.; Puglisi, Fabrizio; Tibullo, Daniele; La Cava, Piera; Giallongo, Cesarina; Parrinello, Nunziatina L.

    2015-01-01

    The better definition of the mutual sustainment between neoplastic cells and immune system has been translated from the bench to the bedside acquiring value as prognostic factor. Additionally, it represents a promising tool for improving therapeutic strategies. In this context, myeloid-derived suppressor cells (MDSCs) have gained a central role in tumor developing with consequent therapeutic implications. In this review, we will focus on the biological and clinical impact of the study of MDSCs in the settings of lymphoid malignancies. PMID:26052505

  4. Cyclophosphamide-induced myeloid-derived suppressor cell population is immunosuppressive but not identical to myeloid-derived suppressor cells induced by growing TC-1 tumors

    Czech Academy of Sciences Publication Activity Database

    Mikyšková, Romana; Indrová, Marie; Polláková, Veronika; Bieblová, Jana; Šímová, Jana; Reiniš, Milan

    2012-01-01

    Roč. 35, č. 5 (2012), s. 374-384 ISSN 1524-9557 R&D Projects: GA ČR(CZ) GPP301/11/P220; GA ČR GA301/09/1024; GA ČR GA301/07/1410 EU Projects: European Commission(XE) 18933 - CLINIGENE Institutional research plan: CEZ:AV0Z50520514 Institutional support: RVO:68378050 Keywords : myeloid-derived suppressor cells * cyclophosphamide * all-trans-retinoic acid * IL-12 * HPV16 Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.463, year: 2012

  5. Immune suppressor factor confers stromal cell line with enhanced supporting activity for hematopoietic stem cells

    International Nuclear Information System (INIS)

    Nakajima, Hideaki; Shibata, Fumi; Fukuchi, Yumi; Goto-Koshino, Yuko; Ito, Miyuki; Urano, Atsushi; Nakahata, Tatsutoshi; Aburatani, Hiroyuki; Kitamura, Toshio

    2006-01-01

    Immune suppressor factor (ISF) is a subunit of the vacuolar ATPase proton pump. We earlier identified a short form of ISF (ShIF) as a stroma-derived factor that supports cytokine-independent growth of mutant Ba/F3 cells. Here, we report that ISF/ShIF supports self-renewal and expansion of primary hematopoietic stem cells (HSCs). Co-culture of murine bone marrow cells with a stromal cell line overexpressing ISF or ShIF (MS10/ISF or MS10/ShIF) not only enhanced their colony-forming activity and the numbers of long-term culture initiating cells, but also maintained the competitive repopulating activity of HSC. This stem cell supporting activity depended on the proton-transfer function of ISF/ShIF. Gene expression analysis of ISF/ShIF-transfected cell lines revealed down-regulation of secreted frizzled-related protein-1 and tissue inhibitor of metalloproteinase-3, and the restoration of their expressions in MS10/ISF cells partially reversed its enhanced LTC-IC supporting activity to a normal level. These results suggest that ISF/ShIF confers stromal cells with enhanced supporting activities for HSCs by modulating Wnt-activity and the extracellular matrix

  6. Tumor Suppressors and Cell-Cycle Proteins in Lung Cancer

    Directory of Open Access Journals (Sweden)

    Alfonso Baldi

    2011-01-01

    Full Text Available The cell cycle is the cascade of events that allows a growing cell to duplicate all its components and split into two daughter cells. Cell cycle progression is mediated by the activation of a highly conserved family of protein kinases, the cyclin-dependent kinases (CDKs. CDKs are also regulated by related proteins called cdk inhibitors grouped into two families: the INK4 inhibitors (p16, p15, p19, and p18 and the Cip/Kip inhibitors (p21, p27, and p53. Several studies report the importance of cell-cycle proteins in the pathogenesis and the prognosis of lung cancer. This paper will review the most recent data from the literature about the regulation of cell cycle. Finally, based essentially on the data generated in our laboratory, the expression, the diagnostic, and prognostic significance of cell-cycle molecules in lung cancer will be examined.

  7. Cancer Stem Cell-Secreted Macrophage Migration Inhibitory Factor Stimulates Myeloid Derived Suppressor Cell Function and Facilitates Glioblastoma Immune Evasion

    DEFF Research Database (Denmark)

    Otvos, Balint; Silver, Daniel J; Mulkearns-Hubert, Erin E

    2016-01-01

    populations, including myeloid-derived suppressor cells (MDSCs), which serve to suppress immune system function. We have identified immune-suppressive MDSCs in the brains of GBM patients and found that they were in close proximity to self-renewing cancer stem cells (CSCs). MDSCs were selectively depleted...... that MIF is primarily an indirect promoter of GBM progression, working to suppress immune rejection by activating and protecting immune suppressive MDSCs within the GBM tumor microenvironment. Stem Cells 2016;34:2026-2039....

  8. Simultaneous loss of the DLC1 and PTEN tumor suppressors enhances breast cancer cell migration

    International Nuclear Information System (INIS)

    Heering, Johanna; Erlmann, Patrik; Olayioye, Monilola A.

    2009-01-01

    The phosphatase and tensin homolog (PTEN) gene is a tumor suppressor frequently deleted or mutated in sporadic tumors of the breast, prostate, endometrium and brain. The protein acts as a dual specificity phosphatase for lipids and proteins. PTEN loss confers a growth advantage to cells, protects from apoptosis and favors cell migration. The deleted in liver cancer 1 (DLC1) gene has emerged as a novel tumor suppressor downregulated in a variety of tumor types including those of the breast. DLC1 contains a Rho GTPase activating domain that is involved in the inhibition of cell proliferation, migration and invasion. To investigate how simultaneous loss of PTEN and DLC1 contributes to cell transformation, we downregulated both proteins by RNA interference in the non-invasive MCF7 breast carcinoma cell line. Joint depletion of PTEN and DLC1 resulted in enhanced cell migration in wounding and chemotactic transwell assays. Interestingly, both proteins were found to colocalize at the plasma membrane and interacted physically in biochemical pulldowns and coimmunoprecipitations. We therefore postulate that the concerted local inactivation of signaling pathways downstream of PTEN and DLC1, respectively, is required for the tight control of cell migration.

  9. Simultaneous loss of the DLC1 and PTEN tumor suppressors enhances breast cancer cell migration

    Energy Technology Data Exchange (ETDEWEB)

    Heering, Johanna; Erlmann, Patrik [University of Stuttgart, Institute of Cell Biology and Immunology, Allmandring 31, 70569 Stuttgart (Germany); Olayioye, Monilola A., E-mail: monilola.olayioye@izi.uni-stuttgart.de [University of Stuttgart, Institute of Cell Biology and Immunology, Allmandring 31, 70569 Stuttgart (Germany)

    2009-09-10

    The phosphatase and tensin homolog (PTEN) gene is a tumor suppressor frequently deleted or mutated in sporadic tumors of the breast, prostate, endometrium and brain. The protein acts as a dual specificity phosphatase for lipids and proteins. PTEN loss confers a growth advantage to cells, protects from apoptosis and favors cell migration. The deleted in liver cancer 1 (DLC1) gene has emerged as a novel tumor suppressor downregulated in a variety of tumor types including those of the breast. DLC1 contains a Rho GTPase activating domain that is involved in the inhibition of cell proliferation, migration and invasion. To investigate how simultaneous loss of PTEN and DLC1 contributes to cell transformation, we downregulated both proteins by RNA interference in the non-invasive MCF7 breast carcinoma cell line. Joint depletion of PTEN and DLC1 resulted in enhanced cell migration in wounding and chemotactic transwell assays. Interestingly, both proteins were found to colocalize at the plasma membrane and interacted physically in biochemical pulldowns and coimmunoprecipitations. We therefore postulate that the concerted local inactivation of signaling pathways downstream of PTEN and DLC1, respectively, is required for the tight control of cell migration.

  10. The Role and Potential Therapeutic Application of Myeloid-Derived Suppressor Cells in Allo- and Autoimmunity

    Directory of Open Access Journals (Sweden)

    Qi Zhang

    2015-01-01

    Full Text Available Myeloid-derived suppressor cells (MDSCs are a heterogeneous population of cells that consists of myeloid progenitor cells and immature myeloid cells. They have been identified as a cell population that may affect the activation of CD4+ and CD8+ T-cells to regulate the immune response negatively, which makes them attractive targets for the treatment of transplantation and autoimmune diseases. Several studies have suggested the potential suppressive effect of MDSCs on allo- and autoimmune responses. Conversely, MDSCs have also been found at various stages of differentiation, accumulating during pathological situations, not only during tumor development but also in a variety of inflammatory immune responses, bone marrow transplantation, and some autoimmune diseases. These findings appear to be contradictory. In this review, we summarize the roles of MDSCs in different transplantation and autoimmune diseases models as well as the potential to target these cells for therapeutic benefit.

  11. Inhibition of human antigen-induced lymphoblastoid B-cell function by an in vivo-induced suppressor T cell.

    Science.gov (United States)

    Brieva, J A; Stevens, R H

    1983-04-01

    Lymphoblastoid (LB) B cells which spontaneously produce antitetanus toxoid IgG antibodies (Tet-IgG) in short-term cultures (3 days) appear in the circulation 5-7 days after immunization with tetanus toxoid. Addition of pokeweed mitogen (PWM), normally a stimulator of antibody production, caused instead a reduction in the in vitro synthesis of Tet-IgG by the LB cells. In order for this inhibition of antibody production to occur, T cells had to be present, and the inhibition was proportional to the number of T cells added to the culture, demonstrating the existence of PWM-inducible suppressor cells. The cells mediating the suppression had the OKT8 phenotype and also exhibited the following characteristics: (1) a PWM pretreatment period as little as 14 hr was enough to complete activation; (2) conventional inhibitors of suppressor T cells as hydrocortisone and cyclosporin A only partially reversed its effect; and (3) DNA synthesis was not required. The T-suppressor activity was detectable in the circulation before immunization, increased two- to fourfold by 5-12 days after boosting, and waned after 3 weeks. The mechanism of action of this suppression does not appear to involve conventional cytotoxic T cells as (1) the suppression was mediated across allogeneic barriers and (2) the suppression could not be reversed by inclusion of anti-Leu-2a antibodies in the culture. These results suggest that this suppressor T-cell subset may be important in the normal regulation of activated stages of human B lymphocytes.

  12. Tumor suppressor protein SMAR1 modulates the roughness of cell surface: combined AFM and SEM study

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    Mamgain Hitesh

    2009-10-01

    Full Text Available Abstract Background Imaging tools such as scanning electron microscope (SEM and atomic force microscope (AFM can be used to produce high-resolution topographic images of biomedical specimens and hence are well suited for imaging alterations in cell morphology. We have studied the correlation of SMAR1 expression with cell surface smoothness in cell lines as well as in different grades of human breast cancer and mouse tumor sections. Methods We validated knockdown and overexpression of SMAR1 using RT-PCR as well as Western blotting in human embryonic kidney (HEK 293, human breast cancer (MCF-7 and mouse melanoma (B16F1 cell lines. The samples were then processed for cell surface roughness studies using atomic force microscopy (AFM and scanning electron microscopy (SEM. The same samples were used for microarray analysis as well. Tumors sections from control and SMAR1 treated mice as well as tissues sections from different grades of human breast cancer on poly L-lysine coated slides were used for AFM and SEM studies. Results Tumor sections from mice injected with melanoma cells showed pronounced surface roughness. In contrast, tumor sections obtained from nude mice that were first injected with melanoma cells followed by repeated injections of SMAR1-P44 peptide, exhibited relatively smoother surface profile. Interestingly, human breast cancer tissue sections that showed reduced SMAR1 expression exhibited increased surface roughness compared to the adjacent normal breast tissue. Our AFM data establishes that treatment of cells with SMAR1-P44 results into increase in cytoskeletal volume that is supported by comparative gene expression data showing an increase in the expression of specific cytoskeletal proteins compared to the control cells. Altogether, these findings indicate that tumor suppressor function of SMAR1 might be exhibited through smoothening of cell surface by regulating expression of cell surface proteins. Conclusion Tumor suppressor

  13. Snail transcription factor negatively regulates maspin tumor suppressor in human prostate cancer cells

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    Neal Corey L

    2012-08-01

    Full Text Available Abstract Background Maspin, a putative tumor suppressor that is down-regulated in breast and prostate cancer, has been associated with decreased cell motility. Snail transcription factor is a zinc finger protein that is increased in breast cancer and is associated with increased tumor motility and invasion by induction of epithelial-mesenchymal transition (EMT. We investigated the molecular mechanisms by which Snail increases tumor motility and invasion utilizing prostate cancer cells. Methods Expression levels were analyzed by RT-PCR and western blot analyses. Cell motility and invasion assays were performed, while Snail regulation and binding to maspin promoter was analyzed by luciferase reporter and chromatin immunoprecipitation (ChIP assays. Results Snail protein expression was higher in different prostate cancer cells lines as compared to normal prostate epithelial cells, which correlated inversely with maspin expression. Snail overexpression in 22Rv1 prostate cancer cells inhibited maspin expression and led to increased migration and invasion. Knockdown of Snail in DU145 and C4-2 cancer cells resulted in up-regulation of maspin expression, concomitant with decreased migration. Transfection of Snail into 22Rv1 or LNCaP cells inhibited maspin promoter activity, while stable knockdown of Snail in C4-2 cells increased promoter activity. ChIP analysis showed that Snail is recruited to the maspin promoter in 22Rv1 cells. Conclusions Overall, this is the first report showing that Snail can negatively regulate maspin expression by directly repressing maspin promoter activity, leading to increased cell migration and invasion. Therefore, therapeutic targeting of Snail may be useful to re-induce expression of maspin tumor suppressor and prevent prostate cancer tumor progression.

  14. Myeloid-derived suppressor cells: paradoxical roles in infection and immunity.

    Science.gov (United States)

    Dai, Jun; El Gazzar, Mohamed; Li, Guang Y; Moorman, Jonathan P; Yao, Zhi Q

    2015-01-01

    Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature suppressor cells that are generated due to aberrant myelopoiesis under pathological conditions. Although MDSCs have been recognized for more than 20 years under the guise of different monikers, these particular populations of myeloid cells gained more attention recently due to their immunosuppressive properties, which halt host immune responses to growing cancers or overwhelming infections. While MDSCs may contribute to immune homeostasis after infection or tissue injury by limiting excessive inflammatory processes, their expansion may be at the expense of pathogen elimination and thus may lead to disease persistence. Therefore, MDSCs may be either damaging or obliging to the host by attenuating, for example, antitumor or anti-infectious immune responses. In this review, we recapitulate the biological and immunological aspects of MDSCs, including their generation, distribution, trafficking and the factors involved in their activation, expansion, suppressive functions, and interplay between MDSCs and regulatory T cells, with a focus on the perspectives of infection and inflammation. © 2014 S. Karger AG, Basel.

  15. Generation of protein-specific and alloantigen-specific suppressor cells following total lymphoid irradiation in mice

    International Nuclear Information System (INIS)

    Slavin, S.; Zan-Bar, I.; Strober, S.

    1979-01-01

    The presence of donor-type specific suppressor cells was demonstrated in C57BL/Ka → BALB/c BM chimeras in both in vivo and in vitro experiments. In both experiments tolerance to either BSA of C57BL/Ka tissue antigens could be transferred into adoptive recipients. In view of the data obtained in BSA-tolerant mice, it is likely that the suppressor cells in the chimeras were also T cells in origin; however, formal proof has yet to be obtained. We conclude that antigen-specific suppressor cells are generated following TLI. Specific transplantation tolerance obtained by immunomanipulation rather than by prolonged use of nonspecific immunosuppressive agents is the goal of clinical BM and organ transplantation. Due to the experience accumulated in patients with Hodgkin's disease regarding the effects and relative safety of using TLI, it may soon become a new clinical tool for BM and organ transplantation in man

  16. Expansion of Myeloid-Derived Suppressor Cells in Patients with Acute Coronary Syndrome

    Directory of Open Access Journals (Sweden)

    Yan-ge Wang

    2015-01-01

    Full Text Available Aim: The aim of this study was to explore whether the circulating frequency and function of myeloid-derived suppressor cells (MDSCs are altered in patients with acute coronary syndrome (ACS. Methods: The frequency of MDSCs in peripheral blood was determined by flow cytometry, and mRNA expression in purified MDSCs was analyzed by real-time reverse transcription polymerase chain reaction (RT-PCR. The suppressive function of MDSCs isolated from different groups was also determined. The plasma levels of certain cytokines were determined using Bio-Plex Pro™ Human Cytokine Assays. Results: The frequency of circulating CD14+HLA-DR-/low MDSCs; arginase-1 (Arg-1 expression; and plasma levels of interleukin (IL-1β, IL-6, tumor necrosis factor (TNF-α, and IL-33 were markedly increased in ACS patients compared to stable angina (SA or control patients. Furthermore, MDSCs from ACS patients were more potent suppressors of T-cell proliferation and IFN-γ production than those from the SA or control groups at ratios of 1:4 and 1:2; this effect was partially mediated by Arg-1. In addition, the frequency of MDSCs was positively correlated with plasma levels of IL-6, IL-33, and TNF-α. Conclusions: We observed an increased frequency and suppressive function of MDSCs in ACS patients, a result that may provide insights into the mechanisms involved in ACS.

  17. Murine neonatal spleen contains natural T and non-T suppressor cells capable of inhibiting adult alloreactive and newborn autoreactive T-cell proliferation.

    Science.gov (United States)

    Hooper, D C; Hoskin, D W; Gronvik, K O; Murgita, R A

    1986-05-01

    The spleen of neonatal mice is known to be a rich source of cells capable of suppressing a variety of immune functions of adult lymphocytes in vitro. From such observations has emerged the concept that the gradual development in ability to express immune functions after birth is due in part to the parallel normal physiological decay of naturally occurring regulatory suppressor cells. There is, however, some confusion in the literature as to the exact nature of the newborn of the newborn inhibitory cell type(s). In contrast to most previous reports which detect only a single type of neonatal suppressor cell, usually a T cell, we show here that newborn spleen harbors both T and non-T inhibitory cells. Both types of suppressor cells could be shown to suppress the proliferative response of adult spleen to alloantigens as well as newborn T cells reacting against self-Ia antigen in the autologous mixed lymphocyte reaction (AMLR). Newborn suppressor T cells were characterized as being non-adherent to Ig-anti-Ig affinity columns, soybean agglutinin receptor negative (SBA-), and susceptible to lysis by anti-T-cell specific antiserum plus complement. Non-T suppressor cells were identified as non-phagocytic, SBA receptor positive (SBA+), and resistant to cytotoxic treatment with anti-T-cell antibodies and complement. The apparent controversy surrounding previous reports as to the T versus non-T nature of newborn suppressor cells can be reconciled by the present observation that both types of inhibitory cells coexist in the spleen. Furthermore, the demonstration that newborn suppressor cells can effectively regulate T-cell proliferative activity mediated by other newborn cells provides more direct support for the contention that such inhibitory cells play a physiological role in controlling immune responsiveness during early ontogeny.

  18. Tumor suppressor gene E-cadherin and its role in normal and malignant cells

    Directory of Open Access Journals (Sweden)

    Pećina-Šlaus Nives

    2003-10-01

    Full Text Available Abstract E-cadherin tumor suppressor genes are particularly active area of research in development and tumorigenesis. The calcium-dependent interactions among E-cadherin molecules are critical for the formation and maintenance of adherent junctions in areas of epithelial cell-cell contact. Loss of E-cadherin-mediated-adhesion characterises the transition from benign lesions to invasive, metastatic cancer. Nevertheless, there is evidence that E-cadherins may also play a role in the wnt signal transduction pathway, together with other key molecules involved in it, such as beta-catenins and adenomatous poliposis coli gene products. The structure and function of E-cadherin, gene and protein, in normal as well as in tumor cells are reviewed in this paper.

  19. Identification of a myeloid-derived suppressor cell cystatin-like protein that inhibits metastasis

    Science.gov (United States)

    Boutté, Angela M.; Friedman, David B.; Bogyo, Matthew; Min, Yongfen; Yang, Li; Lin, P. Charles

    2011-01-01

    Myeloid-derived suppressor cells (MDSCs) are significantly increased in cancer patients and tumor bearing-animals. MDSCs infiltrate into tumors and promote tumor invasion and metastasis. To identify the mediator responsible for the prometastatic property of MDSCs, we used proteomics. We found neutrophilic granule protein (NGP) was decreased >2-fold in MDSCs from metastatic 4T1 tumor-bearing mice compared to nonmetastatic 67NR controls. NGP mRNA levels were decreased in bone marrow and in tumor-infiltrating MDSCs by 45 and 66%, respectively, in 4T1 tumor-bearing mice compared to 67NR controls. Interestingly, 4T1-conditioned medium reduced myeloid cell NGP expression by ∼40%, suggesting that a secreted factor mediates gene reduction. Sequence analysis shows a putative cystatin domain in NGP, and biochemical analysis confirms NGP a novel cathepsin inhibitor. It inhibited cathepsin B activity by nearly 40% in vitro. NGP expression in 4T1 tumor cells suppressed cell invasion, delayed primary tumor growth, and greatly reduced lung metastasis in vivo. A 2.8-fold reduction of cathepsin activity was found in tumors expressing NGP compared to controls. NGP significantly reduced tumor angiogenesis to 12.6 from 19.6 and lymphangiogenesis to 4.6 from 9.1 vessels/field. Necrosis was detectable only in NGP-expressing tumors, and the number of apoptotic cells increased to 22.4 from 8.3 in controls. Taken together, this study identifies a negative regulator of tumor metastasis in MDSCs, NGP, which is down-regulated in metastatic conditions. The finding suggests that malignant tumors promote invasion/metastasis not only through up-regulation of proteases but also down-regulation of protease inhibitors.—Boutté, A. M., Friedman, D. B., Bogyo, M., Min, Y., Yang, L., Lin, P. C. Identification of a myeloid-derived suppressor cell cystatin-like protein that inhibits metastasis. PMID:21518852

  20. The von Hippel-Lindau tumor suppressor regulates programmed cell death 5-mediated degradation of Mdm2

    NARCIS (Netherlands)

    Essers, P B; Klasson, T D; Pereboom, T C; Mans, D A; Nicastro, M; Boldt, K; Giles, R H; MacInnes, A W

    2015-01-01

    Functional loss of the von Hippel-Lindau (VHL) tumor suppressor protein (pVHL), which is part of an E3-ubiquitin ligase complex, initiates most inherited and sporadic clear-cell renal cell carcinomas (ccRCC). Genetic inactivation of the TP53 gene in ccRCC is rare, suggesting that an alternate

  1. Acquisition of repertoires of suppressor T cells under the influence of macrophages

    International Nuclear Information System (INIS)

    Soejima, T.; Nagayama, A.; Sado, T.; Taniguchi, M.

    1988-01-01

    Acquisition of repertoires and genetic restriction specificities of suppressor T cells (Ts) and their factors were studied by using full allogeneic radiation bone marrow chimera and H-2 congenic pairs, B10.A(3R) and B10.A(5R), which received conventional or cloned macrophages by cell transfer. Suppressor T-cell factor (TsF) from C3H----C57BL/6 or C57BL/6----C3H chimera suppressed only donor but not host-type responses of either C3H or C57BL/6, in an antigen-specific fashion. However, if chimera mice were given conventional or cloned macrophages of the host type, the chimera TsF in turn suppressed both the responses of C3H and C57BL/6 mice but not those of the third party, BALB/c, indicating that macrophages are responsible for the acquisition of host restriction specificity. Similarly, B10.A(5R) mice developed I-Jb restricted Ts or TsF when the B10.A(3R) macrophage cell line was injected at the time of antigen priming. The reverse was also true. B10.A(3R) mice did generate I-Jk restricted Ts when they received the B10.A(5R) macrophage cell line. Thus, the results clearly demonstrated that B10.A(3R) or B10.A(5R) mice potentially possessed their ability to express both I-Jk and I-Jb determinants and that repertoires and genetic restriction specificity of Ts and their TsF were acquired at a macrophage level at the time of antigen-priming

  2. NDRG2 is a candidate tumor-suppressor for oral squamous-cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Furuta, Hiroshi; Kondo, Yuudai [Division of Oral and Maxillofacial Surgery, Medicine of Sensory and Motor Organs, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki-gun, Miyazaki 889-1692 (Japan); Division of Tumor and Cellular Biochemistry, Department of Medical Sciences, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki-gun, Miyazaki 889-1692 (Japan); Nakahata, Shingo; Hamasaki, Makoto [Division of Tumor and Cellular Biochemistry, Department of Medical Sciences, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki-gun, Miyazaki 889-1692 (Japan); Sakoda, Sumio [Division of Oral and Maxillofacial Surgery, Medicine of Sensory and Motor Organs, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki-gun, Miyazaki 889-1692 (Japan); Morishita, Kazuhiro, E-mail: kmorishi@med.miyazaki-u.ac.jp [Division of Tumor and Cellular Biochemistry, Department of Medical Sciences, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki-gun, Miyazaki 889-1692 (Japan)

    2010-01-22

    Oral cancer is one of the most common cancers worldwide, and squamous-cell carcinoma (OSCC) is the most common phenotype of oral cancer. Although patients with OSCC have poor survival rates and a high incidence of metastasis, the molecular mechanisms of OSCC development have not yet been elucidated. This study investigated whether N-myc downstream-regulated gene 2 (NDRG2) contributes to the carcinogenesis of OSCC, as NDRG2 is reported to be a candidate tumor-suppressor gene in a wide variety of cancers. The down-regulation of NDRG2 mRNA, which was dependent on promoter methylation, was seen in the majority of OSCC cases and in several cases of precancerous leukoplakia with dysplasia. Induction of NDRG2 expression in an HSC-3/OSCC cell line significantly inhibited cell proliferation and decreased colony formation ability on soft agar. The majority of OSCC cell lines showed an activation of PI3K/Akt signaling, and enforced expression of NDRG2 in HSC-3 cells decreased the level of phosphorylated Akt at Serine 473 (p-Akt). Immunohistochemical p-Akt staining was detected in 56.5% of the OSCC tumors, and 80.4% of the tumors were negative for NDRG2 staining. Moreover, positive p-Akt staining was inversely correlated with decreased NDRG2 expression in OSCC tumors with moderate to poor differentiation (p < 0.005). Therefore, NDRG2 is a candidate tumor-suppressor gene for OSCC development and probably contributes to the tumorigenesis of OSCC partly via the modulation of Akt signaling.

  3. Immortalized myeloid suppressor cells trigger apoptosis in antigen-activated T lymphocytes.

    Science.gov (United States)

    Apolloni, E; Bronte, V; Mazzoni, A; Serafini, P; Cabrelle, A; Segal, D M; Young, H A; Zanovello, P

    2000-12-15

    We described a generalized suppression of CTL anamnestic responses that occurred in mice bearing large tumor nodules or immunized with powerful recombinant viral immunogens. Immune suppression entirely depended on GM-CSF-driven accumulation of CD11b(+)/Gr-1(+) myeloid suppressor cells (MSC) in secondary lymphoid organs. To further investigate the nature and properties of MSC, we immortalized CD11b(+)/Gr-1(+) cells isolated from the spleens of immunosuppressed mice, using a retrovirus encoding the v-myc and v-raf oncogenes. Immortalized cells expressed monocyte/macrophage markers (CD11b, F4/80, CD86, CD11c), but they differed from previously characterized macrophage lines in their capacities to inhibit T lymphocyte activation. Two MSC lines, MSC-1 and MSC-2, were selected based upon their abilities to inhibit Ag-specific proliferative and functional CTL responses. MSC-1 line was constitutively inhibitory, while suppressive functions of MSC-2 line were stimulated by exposure to the cytokine IL-4. Both MSC lines triggered the apoptotic cascade in Ag-activated T lymphocytes by a mechanism requiring cell-cell contact. Some well-known membrane molecules involved in the activation of apoptotic pathways (e.g., TNF-related apoptosis-inducing ligand, Fas ligand, TNF-alpha) were ruled out as candidate effectors for the suppression mechanism. The immortalized myeloid lines represent a novel, useful tool to shed light on the molecules involved in the differentiation of myeloid-related suppressors as well as in the inhibitory pathway they use to control T lymphocyte activation.

  4. Characterization of membrane determinant in old T-cells with suppressor activity

    International Nuclear Information System (INIS)

    Hendricks, L.C.; Heidrick, M.L.

    1986-01-01

    T-cell function declines with age. Many T-cell functions are initiated at the cell membrane; therefore, age-related membrane alterations may contribute to loss of function. They have previously reported developing a monoclonal antibody, HH-AGE-T(1), which recognizes a cell with suppressor activity and binds to 15-20% of the T-cells from old BC3F 1 mice, but only to 0-4% of young T-cells. To further characterize the determinant recognized by HH-AGE-T(1), they analyzed immunoprecipitates (IP) of young and old T-cell membranes by 2D-SDS PAGE, followed by Western blotting. Immunodetection of the blots showed that HH-AGE-T(1) bound a heterodimer (66 kD, pI 8.44 and 36 kD, pI 5.82-7.12 subunits) in IP from old mice; but not young mice. Monoclonal anti-Lyt 2 antibody did not bind the determinant. When IP of iodinated T-cells were run on SDS-PAGE gels followed by blotting and autoradiography of the blots, very prominent bands were detected in the old sample and faint bands were detected in the young sample. These results suggest that HH-AGE-T(1) recognizes a membrane protein which is present in small amounts on young T-cells but which increases markedly with age. Further studies are needed to determine the significance of this age-related membrane change

  5. Expression of arf tumor suppressor in spermatogonia facilitates meiotic progression in male germ cells.

    Directory of Open Access Journals (Sweden)

    Michelle L Churchman

    2011-07-01

    Full Text Available The mammalian Cdkn2a (Ink4a-Arf locus encodes two tumor suppressor proteins (p16(Ink4a and p19(Arf that respectively enforce the anti-proliferative functions of the retinoblastoma protein (Rb and the p53 transcription factor in response to oncogenic stress. Although p19(Arf is not normally detected in tissues of young adult mice, a notable exception occurs in the male germ line, where Arf is expressed in spermatogonia, but not in meiotic spermatocytes arising from them. Unlike other contexts in which the induction of Arf potently inhibits cell proliferation, expression of p19(Arf in spermatogonia does not interfere with mitotic cell division. Instead, inactivation of Arf triggers germ cell-autonomous, p53-dependent apoptosis of primary spermatocytes in late meiotic prophase, resulting in reduced sperm production. Arf deficiency also causes premature, elevated, and persistent accumulation of the phosphorylated histone variant H2AX, reduces numbers of chromosome-associated complexes of Rad51 and Dmc1 recombinases during meiotic prophase, and yields incompletely synapsed autosomes during pachynema. Inactivation of Ink4a increases the fraction of spermatogonia in S-phase and restores sperm numbers in Ink4a-Arf doubly deficient mice but does not abrogate γ-H2AX accumulation in spermatocytes or p53-dependent apoptosis resulting from Arf inactivation. Thus, as opposed to its canonical role as a tumor suppressor in inducing p53-dependent senescence or apoptosis, Arf expression in spermatogonia instead initiates a salutary feed-forward program that prevents p53-dependent apoptosis, contributing to the survival of meiotic male germ cells.

  6. Mechanisms maintaining enhancement of allografts. I. Demonstration of a specific suppressor cell

    International Nuclear Information System (INIS)

    Hall, B.M.

    1985-01-01

    DA rats treated with hyperimmune anti-PVG serum and grafted with (DA X PVG)F1 heart grafts in which graft survival was prolonged for greater than 75 d were used to examine the cellular mechanisms that maintain the state of specific unresponsiveness found in these animals. The capacity of lymphocytes from these animals to effect or inhibit graft rejection on adoptive transfer to irradiated heart-grafted hosts was tested. Spleen cell populations and the T cell subpopulation separated from spleen cells in vitro failed to restore rejection of PVG heart grafts in irradiated DA recipients but restored third party Lew graft rejection. Whole spleen cells had the capacity to suppress the ability of normal DA LNC to cause graft rejection, but T cells from spleen only delayed the restoration of rejection. LNC and recirculating T cells from rats with enhanced grafts adoptively restored PVG rejection, however. These studies show that the state of specific unresponsiveness that follows the induction of passive enhancement is dependent in part upon active suppression, which is induced or mediated by T lymphocytes. The recirculating pool of lymphocytes in these animals is not depleted of specific alloreactive cells with the capacity to initiate and effect rejection. Thus, these animals responsiveness is not like that found in transplantation tolerance induced in neonatal rats, but is, in part, due to a suppressor response that can inhibit normal alloreactive cells capacity to initiate and effect rejection

  7. TIG3 tumor suppressor-dependent organelle redistribution and apoptosis in skin cancer cells.

    Directory of Open Access Journals (Sweden)

    Tiffany M Scharadin

    Full Text Available TIG3 is a tumor suppressor protein that limits keratinocyte survival during normal differentiation. It is also important in cancer, as TIG3 level is reduced in tumors and in skin cancer cell lines, suggesting that loss of expression may be required for cancer cell survival. An important goal is identifying how TIG3 limits cell survival. In the present study we show that TIG3 expression in epidermal squamous cell carcinoma SCC-13 cells reduces cell proliferation and promotes morphological and biochemical apoptosis. To identify the mechanism that drives these changes, we demonstrate that TIG3 localizes near the centrosome and that pericentrosomal accumulation of TIG3 alters microtubule and microfilament organization and organelle distribution. Organelle accumulation at the centrosome is a hallmark of apoptosis and we demonstrate that TIG3 promotes pericentrosomal organelle accumulation. These changes are associated with reduced cyclin D1, cyclin E and cyclin A, and increased p21 level. In addition, Bax level is increased and Bcl-XL level is reduced, and cleavage of procaspase 3, procaspase 9 and PARP is enhanced. We propose that pericentrosomal localization of TIG3 is a key event that results in microtubule and microfilament redistribution and pericentrosomal organelle clustering and that leads to cancer cell apoptosis.

  8. Regional CAR-T cell infusions for peritoneal carcinomatosis are superior to systemic delivery.

    Science.gov (United States)

    Katz, S C; Point, G R; Cunetta, M; Thorn, M; Guha, P; Espat, N J; Boutros, C; Hanna, N; Junghans, R P

    2016-05-01

    Metastatic spread of colorectal cancer (CRC) to the peritoneal cavity is common and difficult to treat, with many patients dying from malignant bowel obstruction. Chimeric antigen receptor T cell (CAR-T) immunotherapy has shown great promise, and we previously reported murine and phase I clinical studies on regional intrahepatic CAR-T infusion for CRC liver metastases. We are now studying intraperitoneal (IP) delivery of CAR-Ts for peritoneal carcinomatosis. Regional IP infusion of CAR-T resulted in superior protection against carcinoembryonic antigen (CEA+) peritoneal tumors, when compared with systemically infused CAR-Ts. IP CAR-Ts also provided prolonged protection against IP tumor re-challenges and demonstrated an increase in effector memory phenotype over time. IP CAR-Ts provided protection against tumor growth at distant subcutaneous (SC) sites in association with increases in serum IFNγ levels. Given the challenges posed by immunoinhibitory pathways in solid tumors, we combined IP CAR-T treatment with suppressor cell targeting. High frequencies of myeloid-derived suppressor cells (MDSC) and regulatory T cells (Treg) were found within the IP tumors, with MDSC expressing high levels of immunosuppressive PD-L1. Combinatorial IP CAR-T treatment with depleting antibodies against MDSC and Treg further improved efficacy against peritoneal metastases. Our data support further development of combinatorial IP CAR-T immunotherapy for peritoneal malignancies.

  9. The LKB1 tumor suppressor differentially affects anchorage independent growth of HPV positive cervical cancer cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Mack, Hildegard I.D.; Munger, Karl, E-mail: kmunger@rics.bwh.harvard.edu

    2013-11-15

    Infection with high-risk human papillomaviruses is causally linked to cervical carcinogenesis. However, most lesions caused by high-risk HPV infections do not progress to cancer. Host cell mutations contribute to malignant progression but the molecular nature of such mutations is unknown. Based on a previous study that reported an association between liver kinase B1 (LKB1) tumor suppressor loss and poor outcome in cervical cancer, we sought to determine the molecular basis for this observation. LKB1-negative cervical and lung cancer cells were reconstituted with wild type or kinase defective LKB1 mutants and we examined the importance of LKB1 catalytic activity in known LKB1-regulated processes including inhibition of cell proliferation and elevated resistance to energy stress. Our studies revealed marked differences in the biological activities of two kinase defective LKB1 mutants in the various cell lines. Thus, our results suggest that LKB1 may be a cell-type specific tumor suppressor. - Highlights: • LKB1 is a tumor suppressor that is linked to Peutz-Jeghers syndrome. • Peutz-Jeghers syndrome patients have a high incidence of cervical cancer. • Cervical cancer is caused by HPV infections. • This study investigates LKB1 tumor suppressor activity in cervical cancer.

  10. PTEN Plays Dual Roles As a Tumor Suppressor in Osteosarcoma Cells.

    Science.gov (United States)

    Xi, Yongming; Chen, Yan

    2017-09-01

    Osteosarcoma (OS) is the most common primary bone cancer, which occurs primarily in children and adolescents. Functional loss of the tumor suppressor PTEN has been demonstrated in bone malignancies including OS. We have recently reported that Pten expression inversely correlates with OS aggressiveness in mouse models. However, the mechanism whereby PTEN exerts its anti-tumor effect remains unknown. In this study, we first examined the expression of PTEN in human OS cell lines including U2OS, MG63 and Saos-2, and found that PTEN expression is reduced as compared to normal human osteoblasts. The downregulation of PTEN also associates with activation of AKT pathway. We then treated previously reported mouse OS tumor cells MOTO-Rank Δ/ΔOC and human OS cell line U2OS with PTEN inhibitor VO-OHpic to investigate how PTEN impacts tumor cell behaviors. Our results showed that PTEN inhibits tumor cell proliferation, migration and invasion, but enhances tumor cell apoptosis. However, PTEN has no effects on tumor cell senescence and chemotaxis. PTEN also fails to induce tumor cells differentiation toward osteoblast lineage. On the other hand, PTEN inhibits tumor associated osteoclast differentiation. Moreover, overexpression of PTEN using gene transfer in U2OS cells inhibits proliferation but increases apoptosis. These findings indicate that PTEN not only targets tumor cells themselves by impacting cell behaviors, but also blocks osteoclast-mediated bone destruction, leading to interruption of the vicious cycle during osteosarcomagenesis. Loss of PTEN may consequently facilitate tumor growth and expansion in bone. Restoration of fully functional PTEN using gene therapy represents a potential approach against OS. J. Cell. Biochem. 118: 2684-2692, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  11. Myeloid-derived suppressor cells mediate tolerance induction in autoimmune disease.

    Science.gov (United States)

    Wegner, Anja; Verhagen, Johan; Wraith, David C

    2017-05-01

    In multiple sclerosis (MS) T cells aberrantly recognize self-peptides of the myelin sheath and attack the central nervous system (CNS). Antigen-specific peptide immunotherapy, which aims to restore tolerance while avoiding the use of non-specific immunosuppressive drugs, is a promising approach to combat autoimmune disease, but the cellular mechanisms behind successful therapy remain poorly understood. Myeloid-derived suppressor cells (MDSCs) have been studied intensively in the field of cancer and to a lesser extent in autoimmunity. Because of their suppressive effect on the immune system in cancer, we hypothesized that the development of MDSCs and their interaction with CD4 + T cells could be beneficial for antigen-specific immunotherapy. Hence, changes in the quantity, phenotype and function of MDSCs during tolerance induction in our model of MS were evaluated. We reveal, for the first time, an involvement of a subset of MDSCs, known as polymorphonuclear (PMN)-MDSCs, in the process of tolerance induction. PMN-MDSCs were shown to adopt a more suppressive phenotype during peptide immunotherapy and inhibit CD4 + T-cell proliferation in a cell-contact-dependent manner, mediated by arginase-1. Moreover, increased numbers of tolerogenic PMN-MDSCs, such as observed over the course of peptide immunotherapy, were demonstrated to provide protection from disease in a model of experimental autoimmune encephalomyelitis. © 2017 John Wiley & Sons Ltd.

  12. microRNA-184 functions as tumor suppressor in renal cell carcinoma.

    Science.gov (United States)

    Su, Zhengming; Chen, Duqun; Li, Yifan; Zhang, Enpu; Yu, Zuhu; Chen, Ting; Jiang, Zhimao; Ni, Liangchao; Yang, Shangqi; Gui, Yaoting; Ye, Jiongxian; Lai, Yongqing

    2015-03-01

    microRNAs (miRNAs) are evolutionarily conserved, endogenous, small, noncoding RNA molecules of approximately 22 nucleotides in length that function as post-transcriptional gene regulators. Their aberrant expression may be involved in human diseases, including cancer. Although miRNA-184 (miR-184) has been reported in other tumors, its function in renal cell carcinoma (RCC) is still unknown. The aim of the present study was to investigate the role of miR-184 in RCC. The impacts of miR-184 on cell migration, proliferation and apoptosis were evaluated using migration scratch, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry assay. Our studies revealed that miR-184 mimic significantly inhibits cell migration, suppresses cell proliferation and induces renal cancer cell apoptosis in vitro when compared with the negative control (P184 played a significant role as a tumor suppressor in RCC. Therefore, miR-184 may be a promising therapeutic target for renal cancer treatment in the future.

  13. Inhibition of SRC family kinases reduces myeloid-derived suppressor cells in head and neck cancer.

    Science.gov (United States)

    Mao, Liang; Deng, Wei-Wei; Yu, Guang-Tao; Bu, Lin-Lin; Liu, Jian-Feng; Ma, Si-Rui; Wu, Lei; Kulkarni, Ashok B; Zhang, Wen-Feng; Sun, Zhi-Jun

    2017-03-01

    SRC family kinases (SFKs), a group of nonreceptor tyrosine kinases, modulate multiple cellular functions, such as cell proliferation, differentiation and metabolism. SFKs display aberrant activity in progressive stages of human cancers. However, the precise role of SFKs in the head and neck squamous cell carcinoma (HNSCC) signaling network is far from clear. In this study, we found that the inhibition of SFKs activity by dasatinib effectively reduced the tumor size and population of MDSCs in the HNSCC mouse model. Molecular analysis indicates that phosphorylation of LYN, rather than SRC, was inhibited by dasatinib treatment. Next, we analyzed LYN expression by immunostaining and found that it was overexpressed in the human HNSCC specimens. Moreover, LYN expression in stromal cells positively correlated with myeloid-derived suppressor cells (MDSCs) makers CD11b and CD33 in human HNSCC. The dual positive expression of LYN in epithelial and stromal cells (EPI + SRT + ) was associated with unfavorable overall survival of HNSCC patients. These findings indicate that SFKs may be a potential target for an effective immunotherapy of HNSCC by decreasing MDSCs and moreover, LYN will have an impact on such therapeutic strategy. © 2016 UICC.

  14. Engineered reversal of drug resistance in cancer cells--metastases suppressor factors as change agents.

    Science.gov (United States)

    Yadav, Vinod Kumar; Kumar, Akinchan; Mann, Anita; Aggarwal, Suruchi; Kumar, Maneesh; Roy, Sumitabho Deb; Pore, Subrata Kumar; Banerjee, Rajkumar; Mahesh Kumar, Jerald; Thakur, Ram Krishna; Chowdhury, Shantanu

    2014-01-01

    Building molecular correlates of drug resistance in cancer and exploiting them for therapeutic intervention remains a pressing clinical need. To identify factors that impact drug resistance herein we built a model that couples inherent cell-based response toward drugs with transcriptomes of resistant/sensitive cells. To test this model, we focused on a group of genes called metastasis suppressor genes (MSGs) that influence aggressiveness and metastatic potential of cancers. Interestingly, modeling of 84 000 drug response transcriptome combinations predicted multiple MSGs to be associated with resistance of different cell types and drugs. As a case study, on inducing MSG levels in a drug resistant breast cancer line resistance to anticancer drugs caerulomycin, camptothecin and topotecan decreased by more than 50-60%, in both culture conditions and also in tumors generated in mice, in contrast to control un-induced cells. To our knowledge, this is the first demonstration of engineered reversal of drug resistance in cancer cells based on a model that exploits inherent cellular response profiles.

  15. Nature of the suppressor cells mediating prolonged graft survival after administration of extracted histocompatibility antigen and cyclosporine

    International Nuclear Information System (INIS)

    Yoshimura, N.; Kahan, B.D.

    1985-01-01

    Antigen-specific suppressor T cells are induced by donor histocompatibility antigen extracted from spleen cells with 3M KCl combined with cyclosporine (Ag-CsA). A single i.v. injection of 5 mg 3M-KCl-extracted donor Buffalo (Buf, RT1b) antigen (Ag) combined with a three day course of CsA prolonged renal allograft survival in Wistar-Furth (WFu, RT1u) hosts to a greater extent (MST 26.5 days) than CsA alone (MST 11.8 days). Peripheral blood lymphocytes (PBL) or spleen cells harvested from Ag-CsA-treated recipients ten days after transplantation inhibited the mixed lymphocyte reaction (MLR) between normal responder WFu cells and irradiated Buf cells (55.6% and 64.4% suppression, respectively, P less than 0.025), but not third-party Brown-Norway (BN, RT1n) stimulator cells (13.6% and -18.3% suppression, respectively, NS). The suppressor effect was not mediated by cytolytic cells; there was neither primary nor secondary cytolytic activity against 51 Cr-labeled Con-A blastoid Buf cells. The suppressor cells were neither adherent to plastic dishes nor to nylon-wool columns. PBL irradiated with 800 rads, but not 1500 rads, suppressed the MLR. A single injection of cyclophosphamide (CY, 25 mg/kg) seven days after transplantation abrogated the suppression induced by Ag-CsA treatment. Moreover, PBL from Ag-CsA recipients failed to suppress the MLR, if depleted either of all T cells by treatment with monoclonal antibody (Mab) W3/13 HLK (pan T cells; % suppression -15.8), or of cytotoxic/suppressor cells with Mab OX-8 (-19.3% suppression) together with rabbit antimouse immunoglobulin and complement

  16. Suppressor T cells, distinct from "veto cells," are induced by alloantigen priming and mediate transferable suppression of cytotoxic T lymphocyte responses in vivo

    DEFF Research Database (Denmark)

    Owens, T; Crispe, I N

    1985-01-01

    of this is that antigen-specific host suppressor T cells (Ts) are activated. Alternatively, donor Lyt-2+ T cells, introduced in the priming inoculum, may inactivate host CTL precursors (CTLp) that recognize the priming (donor) alloantigens. Donor cells that act in this way are termed veto T cells. The experiments...

  17. Tumor suppressor molecules and methods of use

    Science.gov (United States)

    Welch, Peter J.; Barber, Jack R.

    2004-09-07

    The invention provides substantially pure tumor suppressor nucleic acid molecules and tumor suppressor polypeptides. The invention also provides hairpin ribozymes and antibodies selective for these tumor suppressor molecules. Also provided are methods of detecting a neoplastic cell in a sample using detectable agents specific for the tumor suppressor nucleic acids and polypeptides.

  18. NIRF constitutes a nodal point in the cell cycle network and is a candidate tumor suppressor.

    Science.gov (United States)

    Mori, Tsutomu; Ikeda, Daisuke D; Fukushima, Toshihiko; Takenoshita, Seiichi; Kochi, Hideo

    2011-10-01

    In biological networks, a small number of "hub" proteins play critical roles in the network integrity and functions. The cell cycle network orchestrates versatile cellular functions through interactions between many signaling modules, whose defects impair diverse cellular processes, often leading to cancer. However, the network architecture and molecular basis that ensure proper coordination between distinct modules are unclear. Here, we show that the ubiquitin ligase NIRF (also known as UHRF2), which induces G1 arrest, interacts with multiple cell cycle proteins including cyclins (A2, B1, D1 and E1), p53 and pRB, and ubiquitinates cyclins D1 and E1. Consistent with its versatility, a bioinformatic network analysis demonstrated that NIRF is an intermodular hub protein that is responsible for the coordination of multiple network modules. Notably, intermodular hubs are frequently associated with oncogenesis. Indeed, we detected loss of heterozygosity of the NIRF gene in several kinds of tumors. When a cancer outlier profile analysis was applied to the Oncomine database, loss of the NIRF gene was found at statistically significant levels in diverse tumors. Importantly, a recurrent microdeletion targeting NIRF was observed in non-small cell lung carcinoma. Furthermore, NIRF is immediately adjacent to the single nucleotide polymorphism rs719725, which is reportedly associated with the risk of colorectal cancer. These observations suggest that NIRF occupies a prominent position within the cell cycle network, and is a strong candidate for a tumor suppressor whose aberration contributes to the pathogenesis of diverse malignancies. © 2011 Landes Bioscience

  19. Suppressor of fused (Sufu) promotes epithelial-mesenchymal transition (EMT) in cervical squamous cell carcinoma

    Science.gov (United States)

    Zhang, Ziyu; Zou, Yang; Liang, Meirong; Chen, Yuanting; Luo, Yong; Yang, Bicheng; Liu, Faying; Qin, Yunna; He, Deming; Wang, Feng; Huang, Ouping

    2017-01-01

    Suppressor of fused is essential for the maximal activation of Sonic Hedgehog signaling in development and tumorigenesis. However, the role of Sufu in cervical carcinoma remains unknown. Here, we report new findings of Sufu in regulating the epithelial-to-mesenchymal transition through the FoxM1 transcriptional modulation by 14-3-3ζ protein in cervical carcinoma. Sufu is overexpressed in cervical squamous cell carcinoma and its level in clinical tumor tissues is positively correlated with 14-3-3ζ. Functionanlly, siSufu remarkably prevents the cancer cell migration and invasion. We further demonstrate that the transcriptional activity of Sufu is increased by FoxM1, of which stability is promoted by 14-3-3ζ. Knockdown FoxM1 decreases the invasion of SiHa cells and reconstitution of Sufu rescues the invasion of these cells.Finally, overexpression of Sufu is significantly associated with differentiation grade, FIGO stage, Depth of stromal invasion and vascular cancer embolus. Our findings highlight a novel role for Sufu in cervical carcinogenesis. PMID:29371981

  20. Regulatory T cells as suppressors of anti-tumor immunity: Role of metabolism.

    Science.gov (United States)

    De Rosa, Veronica; Di Rella, Francesca; Di Giacomo, Antonio; Matarese, Giuseppe

    2017-06-01

    Novel concepts in immunometabolism support the hypothesis that glucose consumption is also used to modulate anti-tumor immune responses, favoring growth and expansion of specific cellular subsets defined in the past as suppressor T cells and currently reborn as regulatory T (Treg) cells. During the 1920s, Otto Warburg and colleagues observed that tumors consumed high amounts of glucose compared to normal tissues, even in the presence of oxygen and completely functioning mitochondria. However, the role of the Warburg Effect is still not completely understood, particularly in the context of an ongoing anti-tumor immune response. Current experimental evidence suggests that tumor-derived metabolic restrictions can drive T cell hyporesponsiveness and immune tolerance. For example, several glycolytic enzymes, deregulated in cancer, contribute to tumor progression independently from their canonical metabolic activity. Indeed, they can control apoptosis, gene expression and activation of specific intracellular pathways, thus suggesting a direct link between metabolic switches and pro-tumorigenic transcriptional programs. Focus of this review is to define the specific metabolic pathways controlling Treg cell immunobiology in the context of anti-tumor immunity and tumor progression. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Estrogen receptor β regulates the tumoral suppressor PTEN to modulate pituitary cell growth.

    Science.gov (United States)

    Perez, Pablo A; Petiti, Juan P; Picech, Florencia; Guido, Carolina B; dV Sosa, Liliana; Grondona, Ezequiel; Mukdsi, Jorge H; De Paul, Ana L; Torres, Alicia I; Gutierrez, Silvina

    2018-02-01

    In this study, we focused on ERβ regulation in the adenohypophysis under different estrogenic milieu, by analyzing whether ER modulates the phosphatase and tensin homolog deleted on chromosome 10 (PTEN) expression and its subcellular localization on anterior pituitary glands from Wistar rats and GH3 lactosomatotroph cells that over-expressed ERβ. ERβ was regulated in a cyclic manner, and underwent dynamic changes throughout the estrous cycle, with decreased ERβ+ cells in estrus and under E2 treatment, but increased in ovariectomized rats. In addition, the ERα/β ratio increased in estrus and under E2 stimulation, but decreased in ovariectomized rats. Double immunofluorescence revealed that lactotroph and somatotroph ERβ+ were significantly decreased in estrus. Also, variations in the PTEN expression was observed, which was diminished with high E2 conditions but augmented with low E2 milieu. The subcellular localization of this phosphatase was cell cycle-dependent, with remarkable changes in the immunostaining pattern: nuclear in arrested pituitary cells but cytoplasmic in stimulated cells, and responding differently to ER agonists, with only DPN being able to increase PTEN expression and retaining it in the nucleus. Finally, ERβ over-expression increased PTEN with a noticeable subcellular redistribution, and with a significant nuclear signal increase in correlation with an increase of cells in G0/G1 phase. These results showed that E2 is able to inhibit ERβ expression and suggests that the tumoral suppressor PTEN might be one of the signaling proteins by which E2, through ERβ, acts to modulate pituitary cell proliferation, thereby adapting endocrine populations in relation with hormonal necessities. © 2017 Wiley Periodicals, Inc.

  2. Suppressor of cytokine signaling 1 modulates invasion and metastatic potential of colorectal cancer cells.

    Science.gov (United States)

    David, Muriel; Naudin, Cécile; Letourneur, Martine; Polrot, Mélanie; Renoir, Jack-Michel; Lazar, Vladimir; Dessen, Philippe; Roche, Serge; Bertoglio, Jacques; Pierre, Josiane

    2014-07-01

    Suppressor of cytokine signaling (SOCS) 1 is an inducible negative regulator of cytokine signaling but its role in human cancer is not completely established. Here we report that, while SOCS1 is expressed in normal colonic epithelium and colon adenocarcinomas, its level decreases during progression of colon adenocarcinomas, the lowest level being found in the most aggressive stage and least differentiated carcinomas. Forced expression of SOCS1 in metastatic colorectal SW620 cells reverses many characteristics of Epithelial-Mesenchymal Transition (EMT), as highlighted by the disappearance of the transcription factor ZEB1 and the mesenchymal form of p120ctn and the re-expression of E-cadherin. Furthermore, miRNA profiling indicated that SOCS1 also up-regulates the expression of the mir-200 family of miRNAs, which can promote the mesenchymal-epithelial transition and reduce tumor cell migration. Accordingly, overexpression of SOCS1 induced cell morphology changes and dramatically reduced tumor cell invasion in vitro. When injected in nude mice, SOCS1-expressing SW620 cells induced metastases in a smaller number of animals than parental SW620 cells, and did not generate any adrenal gland or bone metastasis. Overall, our results suggest that SOCS1 controls metastatic progression of colorectal tumors by preventing the mesenchymal-epithelial transition (MET), including E-cadherin expression. This pathway may be associated with survival to colorectal cancer by reducing the capacity of generating metastases. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  3. Expansion of monocytic myeloid-derived suppressor cells in endometriosis patients: A pilot study.

    Science.gov (United States)

    Chen, Haiwen; Qin, Shuang; Lei, Aihua; Li, Xing; Gao, Qi; Dong, Jingyin; Xiao, Qing; Zhou, Jie

    2017-06-01

    Endometriosis is a chronic inflammation disease and is closely associated with immune dysregulation. Myeloid-derived suppressor cells (MDSCs) are a negative regulator of the immune system. The aim of this study was to evaluate the possible role of MDSCs in endometriosis patients. We collected the peripheral blood and peritoneal fluid from endometriosis patients and controls and analyzed M-MDSCs level using specific monoclonal antibodies recognizing HLA-DR, CD33, CD11b, CD14 markers by flow cytometry. We found that there existed abnormal expansion of monocytic MDSCs (M-MDSCs) (HLA-DR -/low CD33 + CD11b + CD14 + ) in peripheral blood and peritoneal fluid of patients with endometriosis. Functional studies revealed that M-MDSCs from endometriosis patients significantly suppressed T-cell responses and produced high level of reactive oxygen species (ROS). The elevation of M-MDSCs from endometriosis patients may contribute to the disease progression. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Restoring Sensitivity to Apoptosis in Prostate Cancer Cells by Reconstitution of the Tumor Suppressor PTEN

    National Research Council Canada - National Science Library

    Whang, Young

    2003-01-01

    ... suppressor PTEN in regulating sensitivity to apoptosis in prostate cancer. We have previously shown that loss of HEN function leads to excessive antiapoptotic signaling through constitutive activation of the Akt protein kinase...

  5. [Changes of Peripheral Blood Marrow-Derived Suppressor Cell Level after Chemotherapy Induction Remission by VDLP Regimen and Their Relationship with Immune System in B-ALL Children].

    Science.gov (United States)

    Guo, Xue-Mei; Fang, Yong-Jun; Lv, Cheng-Lan; Wang, Yong-Ren; Sun, Xiao-Yan

    2017-12-01

    To investigate the changes of peripheral blood marrow-derived suppressor cell level after chemotherapy induction remission by regimen consisting of vincristine, daunorubicin, L-asparaginase and prednisone (VDLP) and to analyze their relationship with immume system in B-ALL children. Thirty B-ALL children after induction remission by VDLP regimen from August 2015 to August 2016 were selected as B-ALL group and 30 normal healthy children were selected as control group. The peripheral blood in 2 groups was collected and detected by flow cytometry, then the ratios of CD30 + cells and CD33 + HLA-DR - marrow-derived suppressor cells, CD14 + CD33 + HLA-DR - marrow-derived suppressor cells and CD15 + CD33 + HLA-DR - marrow-derived suppressor cells were calculated, and their changes after induction remission by VDLP regimen and the relationship with immune system were analyzed. After treatment the ratio of CD33 + cells in peripheral blood of B-ALL group and control group was not significantly different (P> 0.05), moreover, the ratio of CD33 + cells in B-ALL group was significantly higher than that before treatment (Pderived suppressor cells, CD14 + CD33 + HLA-DR - marrow-derived suppressor cells and CD15 + CD33 + HLA-DR - marrow-derived suppressor cells in B-ALL group were significantly lower than those in control group (all P0.05). The ratios of marrow-derived suppressor cells in peripheral blood of B-ALL children in complete remission after treatment with VDLP regimen are higher than those before treatment, but are significantly lower than normal value, which may be related with non-complese recovery of immune system in B-ALL children after treatment.

  6. miR-34a expands myeloid-derived suppressor cells via apoptosis inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Anfei, E-mail: huang_anfei@163.com [Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, Jiangsu Province (China); Zhang, Haitao, E-mail: zhanghtjp@126.com [Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou 215021, Jiangsu Province (China); Chen, Si, E-mail: chensisdyxb@126.com [Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, Jiangsu Province (China); Xia, Fei, E-mail: xiafei87@gmail.com [Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, Jiangsu Province (China); Yang, Yi, E-mail: 602744364@qq.com [Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, Jiangsu Province (China); Dong, Fulu, E-mail: adiok0903@126.com [Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, Jiangsu Province (China); Sun, Di, E-mail: dongfl@suda.edu.cn [Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, Jiangsu Province (China); Xiong, Sidong, E-mail: sdxiong@suda.edu.cn [Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, Jiangsu Province (China); Zhang, Jinping, E-mail: j_pzhang@suda.edu.cn [Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, Jiangsu Province (China)

    2014-08-15

    Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population and show significant expansion under pathological conditions. microRNA plays important roles in many biological processes, whether microRNAs have a function in the expansion of MDSCs is still not very clear. In this study, miR-34a overexpression can induce the expansion of MDSCs in bone marrow chimera and transgenic mice model. The experimental results suggest that miR-34a inhibited the apoptosis of MDSCs but did not affect the proliferation of MDSCs. The distinct mRNA microarray profiles of MDSCs of wild type and miR-34a over-expressing MDSCs combined with the target prediction of miR-34a suggest that miR-34a may target genes such as p2rx7, Tia1, and plekhf1 to inhibit the apoptosis of MDSCs. Taken together, miR-34a contributes to the expansion of MDSCs by inhibiting the apoptosis of MDSCs. - Highlights: • Over-expression of miR-34a increases the number of MDSCs. • miR-34a inhibits the apoptosis of MDSCs, but does not affects their proliferation. • miR-34a may inhibit the apoptosis of MDSCs via targeting the p2rx7, Tia1 and plekhf1.

  7. Characterization of the tumor suppressor gene WWOX in primary human oral squamous cell carcinomas

    Science.gov (United States)

    Pimenta, Flávio J.; Gomes, Dawidson A.; Perdigão, Paolla F.; Barbosa, Alvimar A.; Romano-Silva, Marco A.; Gomez, Marcus V.; Aldaz, C. Marcelo; De Marco, Luiz; Gomez, Ricardo S.

    2014-01-01

    Oral squamous cell carcinoma (OSCC) is the most common malignant neoplasm of the oral cavity, representing ~90% of all oral carcinomas and accounting for 3–5% of all malignancies. The WWOX gene (WW-domain containing oxidoreductase) is a candidate tumor suppressor gene located at 16q23.3–24.1, spanning the second most common fragile site, FRA16D. In this report, the role of the WWOX gene was investigated in 20 tumors and 10 normal oral mucosas, and we demonstrated an altered WWOX gene in 50% (10/20) of OSCCs. Using nested RT-PCR, mRNA transcription was altered in 35% of the tumors, with the complete absence of transcripts in 2 samples as well as absence of exons 6–8 (2 tumors), exon 7 (1 tumor), exon 7 and exon 6–8 (1 tumor) and partial loss of exons 8 and 9 (1 tumor). To determine if the aberrant transcripts were translated, Western blots were performed in all samples; however, only the normal protein was detected. By immunohistochemistry, a reduction in Wwox protein expression was observed, affecting 40% of the tumors when compared with normal mucosa. In addition, a novel somatic mutation (S329F) was found. The presence of alterations in mRNA transcription correlated with the reduced expression of Wwox protein in the tumors. These results show that the WWOX gene is frequently altered in OSCC and may contribute to the carcinogenesis processes in oral cancer. PMID:16152610

  8. Role of tumor suppressor genes in the cancer-associated reprogramming of human induced pluripotent stem cells.

    Science.gov (United States)

    Lin, Ying-Chu; Murayama, Yoshinobu; Hashimoto, Koichiro; Nakamura, Yukio; Lin, Chang-Shin; Yokoyama, Kazunari K; Saito, Shigeo

    2014-01-01

    Because of their pluripotent characteristics, human induced pluripotent stem cells (iPSCs) possess great potential for therapeutic application and for the study of degenerative disorders. These cells are generated from normal somatic cells, multipotent stem cells, or cancer cells. They express embryonic stem cell markers, such as OCT4, SOX2, NANOG, SSEA-3, SSEA-4, and REX1, and can differentiate into all adult tissue types, both in vitro and in vivo. However, some of the pluripotency-promoting factors have been implicated in tumorigenesis. Here, we describe the merits of tumor suppresser genes as reprogramming factors for the generation of iPSCs without tumorigenic activity. The initial step of reprogramming is induction of the exogenous pluripotent factors to generate the oxidative stress that leads to senescence by DNA damage and metabolic stresses, thus inducing the expression of tumor suppressor genes such as p21CIP1 and p16INK4a through the activation of p53 to be the pre-induced pluripotent stem cells (pre-iPSCs). The later stage includes overcoming the barrier of reprogramming-induced senescence or cell-cycle arrest by shutting off the function of these tumor suppressor genes, followed by the induction of endogenous stemness genes for the full commitment of iPSCs (full-iPSCs). Thus, the reactive oxygen species (ROS) produced by oxidative stress might be critical for the induction of endogenous reprogramming-factor genes via epigenetic changes or antioxidant reactions. We also discuss the critical role of tumor suppressor genes in the evaluation of the tumorigenicity of human cancer cell-derived pluripotent stem cells, and describe how to overcome their tumorigenic properties for application in stem cell therapy in the field of regenerative medicine.

  9. Recent advances and potential applications of modulated differential scanning calorimetry (mDSC) in drug development

    DEFF Research Database (Denmark)

    Knopp, Matthias Manne; Löbmann, Korbinian; Elder, David P.

    2016-01-01

    Differential scanning calorimetry (DSC) is frequently the thermal analysis technique of choice within preformulation and formulation sciences because of its ability to provide detailed information about both the physical and energetic properties of a substance and/or formulation. However......, conventional DSC has shortcomings with respect to weak transitions and overlapping events, which could be solved by the use of the more sophisticated modulated DSC (mDSC). mDSC has multiple potential applications within the pharmaceutical field and the present review provides an up-to-date overview...

  10. Myeloid-derived suppressor cells as a Trojan horse: A cellular vehicle for the delivery of oncolytic viruses.

    Science.gov (United States)

    Pan, Ping-Ying; Chen, Hui-Ming; Chen, Shu-Hsia

    2013-08-01

    We have recently demonstrated that oncolytic vesicular stomatitis viruses can be efficiently and selectively delivered to neoplastic lesions by myeloid-derived suppressor cells (MDSCs). Importantly, the loading of viruses onto MDSCs inhibited their immunosuppressive properties and endowed them with immunostimulatory and tumoricidal functions. Our study demonstrates the potential use of MDSCs as a Trojan horse for the tumor-targeted delivery of various anticancer therapeutics.

  11. Tumor suppressor NDRG2 inhibits glycolysis and glutaminolysis in colorectal cancer cells by repressing c-Myc expression.

    Science.gov (United States)

    Xu, Xinyuan; Li, Jianying; Sun, Xiang; Guo, Yan; Chu, Dake; Wei, Li; Li, Xia; Yang, Guodong; Liu, Xinping; Yao, Libo; Zhang, Jian; Shen, Lan

    2015-09-22

    Cancer cells use glucose and glutamine as the major sources of energy and precursor intermediates, and enhanced glycolysis and glutamimolysis are the major hallmarks of metabolic reprogramming in cancer. Oncogene activation and tumor suppressor gene inactivation alter multiple intracellular signaling pathways that affect glycolysis and glutaminolysis. N-Myc downstream regulated gene 2 (NDRG2) is a tumor suppressor gene inhibiting cancer growth, metastasis and invasion. However, the role and molecular mechanism of NDRG2 in cancer metabolism remains unclear. In this study, we discovered the role of the tumor suppressor gene NDRG2 in aerobic glycolysis and glutaminolysis of cancer cells. NDRG2 inhibited glucose consumption and lactate production, glutamine consumption and glutamate production in colorectal cancer cells. Analysis of glucose transporters and the catalytic enzymes involved in glycolysis revealed that glucose transporter 1 (GLUT1), hexokinase 2 (HK2), pyruvate kinase M2 isoform (PKM2) and lactate dehydrogenase A (LDHA) was significantly suppressed by NDRG2. Analysis of glutamine transporter and the catalytic enzymes involved in glutaminolysis revealed that glutamine transporter ASC amino-acid transporter 2 (ASCT2) and glutaminase 1 (GLS1) was also significantly suppressed by NDRG2. Transcription factor c-Myc mediated inhibition of glycolysis and glutaminolysis by NDRG2. More importantly, NDRG2 inhibited the expression of c-Myc by suppressing the expression of β-catenin, which can transcriptionally activate C-MYC gene in nucleus. In addition, the growth and proliferation of colorectal cancer cells were suppressed significantly by NDRG2 through inhibition of glycolysis and glutaminolysis. Taken together, these findings indicate that NDRG2 functions as an essential regulator in glycolysis and glutaminolysis via repression of c-Myc, and acts as a suppressor of carcinogenesis through coordinately targeting glucose and glutamine transporter, multiple catalytic

  12. Activated NKT cells facilitated functional switch of myeloid-derived suppressor cells at inflammation sites in fulminant hepatitis mice.

    Science.gov (United States)

    Wu, Danxiao; Shi, Yu; Wang, Cheng; Chen, Hanwen; Liu, Qiaoyun; Liu, Jianhua; Zhang, Lihuang; Wu, Yihua; Xia, Dajing

    2017-02-01

    Myeloid-derived suppressor cells (MDSCs) confer immunosuppressive properties, but their roles in fulminant hepatitis have not been well defined. In this study, we systematically examined the distribution of MDSCs in bone marrow (BM), liver and spleen, and their functional and differentiation status in an acute fulminant hepatitis mouse model induced by lipopolysaccharide and D-galactosamine (LPS-GalN). Moreover, the interaction between NKT cells and MDSCs was determined. Our study revealed that BM contained the largest pool of MDSCs during pathogenesis of fulminant hepatitis compared with liver and spleen. MDSCs in liver/spleen expressed higher levels of chemokine receptors such as CCR2, CX3CR1 and CXCR2. At inflamed tissues such as liver or spleen, activated NKT cells induced differentiation of MDSCs through cell-cell interaction, which markedly dampened the immunosuppressive effects and promoted MDSCs to produce pro-inflammatory cytokines and activate inflammatory cells. Our findings thus demonstrated an unexpected pro-inflammatory state for MDSCs, which was mediated by the activated NKT cells that precipitated the differentiation and functional evolution of these MDSCs at sites of inflammation. Copyright © 2016. Published by Elsevier GmbH.

  13. SPARC overexpression inhibits cell proliferation in neuroblastoma and is partly mediated by tumor suppressor protein PTEN and AKT.

    Directory of Open Access Journals (Sweden)

    Praveen Bhoopathi

    Full Text Available Secreted protein acidic and rich in cysteine (SPARC is also known as BM-40 or Osteonectin, a multi-functional protein modulating cell-cell and cell-matrix interactions. In cancer, SPARC is not only linked with a highly aggressive phenotype, but it also acts as a tumor suppressor. In the present study, we sought to characterize the function of SPARC and its role in sensitizing neuroblastoma cells to radio-therapy. SPARC overexpression in neuroblastoma cells inhibited cell proliferation in vitro. Additionally, SPARC overexpression significantly suppressed the activity of AKT and this suppression was accompanied by an increase in the tumor suppressor protein PTEN both in vitro and in vivo. Restoration of neuroblastoma cell radio-sensitivity was achieved by overexpression of SPARC in neuroblastoma cells in vitro and in vivo. To confirm the role of the AKT in proliferation inhibited by SPARC overexpression, we transfected neuroblastoma cells with a plasmid vector carrying myr-AKT. Myr-AKT overexpression reversed SPARC-mediated PTEN and increased proliferation of neuroblastoma cells in vitro. PTEN overexpression in parallel with SPARC siRNA resulted in decreased AKT phosphorylation and proliferation in vitro. Taken together, these results establish SPARC as an effector of AKT-PTEN-mediated inhibition of proliferation in neuroblastoma in vitro and in vivo.

  14. The hookworm tissue inhibitor of metalloproteases (Ac-TMP-1 modifies dendritic cell function and induces generation of CD4 and CD8 suppressor T cells.

    Directory of Open Access Journals (Sweden)

    Carmen Cuéllar

    Full Text Available Hookworm infection is a major cause of disease burden for humans. Recent studies have described hookworm-related immunosuppression in endemic populations and animal models. A Tissue Inhibitor of Metalloproteases (Ac-TMP-1 has been identified as one of the most abundant proteins released by the adult parasite. We investigated the effect of recombinant Ac-TMP-1 on dendritic cell (DC and T cell function. Splenic T cells from C57BL/6 mice injected with Ac-TMP-1 showed reduced proliferation to restimulation with anti CD3 or bystander antigens such as OVA. Incubation of bone marrow-derived DCs with Ac-TMP-1 decreased MHC Class I and, especially, Class II expression but increased CD86 and IL-10 expression. Co-incubation of splenic T cells with DCs pulsed with Ac-TMP-1 induced their differentiation into CD4+ and, particularly, CD8+ CD25+Foxp3+ T cells that expressed IL-10. These cells were able to suppress proliferation of naïve and activated CD4+ T cells by TGF-Beta-dependent (CD4+ suppressors or independent (CD8+ suppressors mechanisms. Priming of DCs with non-hookworm antigens, such as OVA, did not result in the generation of suppressor T cells. These data indicate that Ac-TMP-1 initiates the development of a regulatory response through modifications in DC function and generation of suppressor T cells. This is the first report to propose a role of suppressor CD8+ T cells in gastrointestinal helminthic infections.

  15. Cancer cell specific cytotoxic gene expression mediated by ARF tumor suppressor promoter constructs

    Energy Technology Data Exchange (ETDEWEB)

    Kurayoshi, Kenta [Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337 (Japan); Ozono, Eiko [Centre for Molecular Oncology, Barts Cancer Institute, Queen Mary, University of London, John Vane Science Centre, Charterhouse Square, London EC1M 6BQ (United Kingdom); Iwanaga, Ritsuko; Bradford, Andrew P. [Department of Obstetrics and Gynecology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045 (United States); Komori, Hideyuki [Center for Stem Cell Biology, Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109 (United States); Ohtani, Kiyoshi, E-mail: btm88939@kwansei.ac.jp [Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337 (Japan)

    2014-07-18

    Highlights: • ARF promoter showed higher responsiveness to deregulated E2F activity than the E2F1 promoter. • ARF promoter showed higher cancer cell-specificity than E2F1 promoter to drive gene expression. • HSV-TK driven by ARF promoter showed higher cancer cell-specific cytotoxicity than that driven by E2F1 promoter. - Abstract: In current cancer treatment protocols, such as radiation and chemotherapy, side effects on normal cells are major obstacles to radical therapy. To avoid these side effects, a cancer cell-specific approach is needed. One way to specifically target cancer cells is to utilize a cancer specific promoter to express a cytotoxic gene (suicide gene therapy) or a viral gene required for viral replication (oncolytic virotherapy). For this purpose, the selected promoter should have minimal activity in normal cells to avoid side effects, and high activity in a wide variety of cancers to obtain optimal therapeutic efficacy. In contrast to the AFP, CEA and PSA promoters, which have high activity only in a limited spectrum of tumors, the E2F1 promoter exhibits high activity in wide variety of cancers. This is based on the mechanism of carcinogenesis. Defects in the RB pathway and activation of the transcription factor E2F, the main target of the RB pathway, are observed in almost all cancers. Consequently, the E2F1 promoter, which is mainly regulated by E2F, has high activity in wide variety of cancers. However, E2F is also activated by growth stimulation in normal growing cells, suggesting that the E2F1 promoter may also be highly active in normal growing cells. In contrast, we found that the tumor suppressor ARF promoter is activated by deregulated E2F activity, induced by forced inactivation of pRB, but does not respond to physiological E2F activity induced by growth stimulation. We also found that the deregulated E2F activity, which activates the ARF promoter, is detected only in cancer cell lines. These observations suggest that ARF promoter

  16. Simultaneous Infiltration of Polyfunctional Effector and Suppressor T Cells into Renal Cell Carcinomas

    NARCIS (Netherlands)

    Attig, Sebastian; Hennenlotter, Jörg; Pawelec, Graham; Klein, Gerd; Koch, Sven D.; Pircher, Hanspeter; Feyerabend, Susan; Wernet, Dorothee; Stenzl, Arnulf; Rammensee, Hans-Georg; Gouttefangeas, Cécile

    2009-01-01

    Renal cell carcinoma is frequently infiltrated by cells of the immune system. This makes it important to understand interactions between cancer cells and immune cells so they can be manipulated to bring clinical benefit. Here, we analyze subsets and functions of T lymphocytes infiltrating renal cell

  17. Myeloid cells in circulation and tumor microenvironment of breast cancer patients.

    Science.gov (United States)

    Toor, Salman M; Syed Khaja, Azharuddin Sajid; El Salhat, Haytham; Faour, Issam; Kanbar, Jihad; Quadri, Asif A; Albashir, Mohamed; Elkord, Eyad

    2017-06-01

    Pathological conditions including cancers lead to accumulation of a morphological mixture of highly immunosuppressive cells termed as myeloid-derived suppressor cells (MDSC). The lack of conclusive markers to identify human MDSC, due to their heterogeneous nature and close phenotypical and functional proximity with other cell subsets, made it challenging to identify these cells. Nevertheless, expansion of MDSC has been reported in periphery and tumor microenvironment of various cancers. The majority of studies on breast cancers were performed on murine models and hence limited literature is available on the relation of MDSC accumulation with clinical settings in breast cancer patients. The aim of this study was to investigate levels and phenotypes of myeloid cells in peripheral blood (n = 23) and tumor microenvironment of primary breast cancer patients (n = 7), compared with blood from healthy donors (n = 21) and paired non-tumor normal breast tissues from the same patients (n = 7). Using multicolor flow cytometric assays, we found that breast cancer patients had significantly higher levels of tumor-infiltrating myeloid cells, which comprised of granulocytes (P = 0.022) and immature cells that lack the expression of markers for fully differentiated monocytes or granulocytes (P = 0.016). Importantly, this expansion was not reflected in the peripheral blood. The immunosuppressive potential of these cells was confirmed by expression of Arginase 1 (ARG1), which is pivotal for T-cell suppression. These findings are important for developing therapeutic modalities to target mechanisms employed by immunosuppressive cells that generate an immune-permissive environment for the progression of cancer.

  18. Grape seed proanthocyanidins reactivate silenced tumor suppressor genes in human skin cancer cells by targeting epigenetic regulators

    Energy Technology Data Exchange (ETDEWEB)

    Vaid, Mudit; Prasad, Ram; Singh, Tripti; Jones, Virginia [Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL 35294 (United States); Katiyar, Santosh K., E-mail: skatiyar@uab.edu [Birmingham Veterans Affairs Medical Center, Birmingham, AL 35294 (United States); Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL 35294 (United States); Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL 35294 (United States)

    2012-08-15

    Grape seed proanthocyanidins (GSPs) have been shown to have anti-skin carcinogenic effects in in vitro and in vivo models. However, the precise epigenetic molecular mechanisms remain unexplored. This study was designed to investigate whether GSPs reactivate silenced tumor suppressor genes following epigenetic modifications in skin cancer cells. For this purpose, A431 and SCC13 human squamous cell carcinoma cell lines were used as in vitro models. The effects of GSPs on DNA methylation, histone modifications and tumor suppressor gene expressions were studied in these cell lines using enzyme activity assays, western blotting, dot-blot analysis and real-time polymerase chain reaction (RT-PCR). We found that treatment of A431 and SCC13 cells with GSPs decreased the levels of: (i) global DNA methylation, (ii) 5-methylcytosine, (iii) DNA methyltransferase (DNMT) activity and (iv) messenger RNA (mRNA) and protein levels of DNMT1, DNMT3a and DNMT3b in these cells. Similar effects were noted when these cancer cells were treated identically with 5-aza-2′-deoxycytidine, an inhibitor of DNA methylation. GSPs decreased histone deacetylase activity, increased levels of acetylated lysines 9 and 14 on histone H3 (H3-Lys 9 and 14) and acetylated lysines 5, 12 and 16 on histone H4, and reduced the levels of methylated H3-Lys 9. Further, GSP treatment resulted in re-expression of the mRNA and proteins of silenced tumor suppressor genes, RASSF1A, p16{sup INK4a} and Cip1/p21. Together, this study provides a new insight into the epigenetic mechanisms of GSPs and may have significant implications for epigenetic therapy in the treatment/prevention of skin cancers in humans. -- Highlights: ►Epigenetic modulations have been shown to have a role in cancer risk. ►Proanthocyanidins decrease the levels of DNA methylation and histone deacetylation. ►Proanthocyanidins inhibit histone deacetylase activity in skin cancer cells. ►Proanthocyanidins reactivate tumor suppressor genes in skin

  19. Grape seed proanthocyanidins reactivate silenced tumor suppressor genes in human skin cancer cells by targeting epigenetic regulators

    International Nuclear Information System (INIS)

    Vaid, Mudit; Prasad, Ram; Singh, Tripti; Jones, Virginia; Katiyar, Santosh K.

    2012-01-01

    Grape seed proanthocyanidins (GSPs) have been shown to have anti-skin carcinogenic effects in in vitro and in vivo models. However, the precise epigenetic molecular mechanisms remain unexplored. This study was designed to investigate whether GSPs reactivate silenced tumor suppressor genes following epigenetic modifications in skin cancer cells. For this purpose, A431 and SCC13 human squamous cell carcinoma cell lines were used as in vitro models. The effects of GSPs on DNA methylation, histone modifications and tumor suppressor gene expressions were studied in these cell lines using enzyme activity assays, western blotting, dot-blot analysis and real-time polymerase chain reaction (RT-PCR). We found that treatment of A431 and SCC13 cells with GSPs decreased the levels of: (i) global DNA methylation, (ii) 5-methylcytosine, (iii) DNA methyltransferase (DNMT) activity and (iv) messenger RNA (mRNA) and protein levels of DNMT1, DNMT3a and DNMT3b in these cells. Similar effects were noted when these cancer cells were treated identically with 5-aza-2′-deoxycytidine, an inhibitor of DNA methylation. GSPs decreased histone deacetylase activity, increased levels of acetylated lysines 9 and 14 on histone H3 (H3-Lys 9 and 14) and acetylated lysines 5, 12 and 16 on histone H4, and reduced the levels of methylated H3-Lys 9. Further, GSP treatment resulted in re-expression of the mRNA and proteins of silenced tumor suppressor genes, RASSF1A, p16 INK4a and Cip1/p21. Together, this study provides a new insight into the epigenetic mechanisms of GSPs and may have significant implications for epigenetic therapy in the treatment/prevention of skin cancers in humans. -- Highlights: ►Epigenetic modulations have been shown to have a role in cancer risk. ►Proanthocyanidins decrease the levels of DNA methylation and histone deacetylation. ►Proanthocyanidins inhibit histone deacetylase activity in skin cancer cells. ►Proanthocyanidins reactivate tumor suppressor genes in skin

  20. Simultaneous infiltration of polyfunctional effector and suppressor T cells into renal cell carcinomas.

    Science.gov (United States)

    Attig, Sebastian; Hennenlotter, Jörg; Pawelec, Graham; Klein, Gerd; Koch, Sven D; Pircher, Hanspeter; Feyerabend, Susan; Wernet, Dorothee; Stenzl, Arnulf; Rammensee, Hans-Georg; Gouttefangeas, Cécile

    2009-11-01

    Renal cell carcinoma is frequently infiltrated by cells of the immune system. This makes it important to understand interactions between cancer cells and immune cells so they can be manipulated to bring clinical benefit. Here, we analyze subsets and functions of T lymphocytes infiltrating renal cell tumors directly ex vivo following mechanical disaggregation and without any culture step. Subpopulations of memory and effector CD4(+) Th1, Th2, and Th17 and CD8(+) Tc1 cells were identified based on surface phenotype, activation potential, and multicytokine production. Compared with the same patient's peripheral blood, T lymphocytes present inside tumors were found to be enriched in functional CD4(+) cells of the Th1 lineage and in effector memory CD8(+) cells. Additionally, several populations of CD4(+) and CD8(+) regulatory T cells were identified that may synergize to locally dampen antitumor T-cell responses.

  1. The role of baculovirus apoptotic suppressors in AcMNPV-mediated translation arrest in Ld652Y cells

    International Nuclear Information System (INIS)

    Thiem, Suzanne M.; Chejanovsky, Nor

    2004-01-01

    Infecting the insect cell line IPLB-Ld652Y with the baculovirus Autographa californica multinucleocapsid nucleopolyhedrovirus (AcMNPV) results in global translation arrest, which correlates with the presence of the AcMNPV apoptotic suppressor, p35. In this study, we investigated the role of apoptotic suppression on AcMNPV-induced translation arrest. Infecting cells with AcMNPV bearing nonfunctional mutant p35 did not result in global translation arrest. In contrast, global translation arrest was observed in cells infected with AcMNPV in which p35 was replaced with Opiap, Cpiap, or p49, baculovirus apoptotic suppressors that block apoptosis by different mechanisms than p35. These results indicated that suppressing apoptosis triggered translation arrest in AcMNPV-infected Ld652Y cells. Experiments using the DNA synthesis inhibitor aphidicolin and temperature shift experiments, using the AcMNPV replication mutants ts8 and ts8Δp35, indicated that translation arrest initiated during the early phase of infection, but events during the late phase were required for global translation arrest. Peptide caspase inhibitors could not substitute for baculovirus apoptotic suppressors to induce translation arrest in Ld652Y cells infected with a p35-null virus. However, if the p35-null-AcMNPV also carried hrf-1, a novel baculovirus host range gene, progeny virus was produced and treatment with peptide caspase inhibitors enhanced translation of a late viral gene transcript. Together, these results indicate that translation arrest in AcMNPV-infected Ld652Y cells is due to the anti-apoptotic function of p35, but suggests that rather than simply preventing caspase activation, its activity enhances signaling to a separate translation arrest pathway, possibly by stimulating the late stages of the baculovirus infection cycle

  2. Dissecting functions of the retinoblastoma tumor suppressor and the related pocket proteins by integrating genetic, cell biology, and electrophoretic techniques

    DEFF Research Database (Denmark)

    Hansen, Klaus; Lukas, J; Holm, K

    1999-01-01

    The members of the 'pocket protein' family, comprising the retinoblastoma tumor suppressor (pRB) and its relatives, p107 and p130, negatively regulate cell proliferation and modulate fundamental biological processes including embryonic development, differentiation, homeostatic tissue renewal......, and defense against cancer. The large, multidomain pocket proteins act by binding a plethora of cell fate-determining and growth-stimulatory proteins, the most prominent of which are the E2F/DP transcription factors. These protein-protein interactions are in turn regulated by carefully orchestrated...

  3. Sodium butyrate induces cell death by autophagy and reactivates a tumor suppressor gene DIRAS1 in renal cell carcinoma cell line UOK146.

    Science.gov (United States)

    Verma, Shiv Prakash; Agarwal, Ayushi; Das, Parimal

    2018-04-01

    Sodium butyrate (SB), a histone deacetylase inhibitor, is emerging as a potent anti-cancer drug for different types of cancers. In the present study, anti-cancer activity of SB in Xp11.2 (TFE3) translocated renal cell carcinoma cell line UOK146 was studied. Anti-proliferative effect of SB in renal cell carcinoma (RCC) cell line UOK146 was evaluated by MTT assay and morphological characteristics were observed by phase contrast microscopy which displayed the cell death after SB treatment. SB induces DNA fragmentation and change in nuclear morphology observed by increased sub-G1 region cell population and nuclear blebbings. Cell cycle arrest at G2/M phase was found after SB treatment. UOK146 cell line shows autophagy mode of cell death as displayed by acridine orange staining and flow cytometry analysis. LC3-II, a protein marker of autophagy, was also found to be upregulated after SB treatment. A tumor suppressor gene DIRAS1 was upregulated after SB treatment, displaying its anti-cancer potential at molecular level. These findings suggest that SB could serve as a novel regulator of tumor suppressors and lead to the discovery of novel therapeutics with better and enhanced anti-cancer activity.

  4. Immunoregulatory changes induced by total lymphoid irradiation. II. Development of thymus-leukemia antigen-positive and -negative suppressor T cells that differ in their regulatory function

    International Nuclear Information System (INIS)

    King, D.P.; Strober, S.

    1981-01-01

    BALB/c mice treated with total lymphoid irradiation (TLI) develop non-antigen-specific suppressor cells of the adoptive secondary antibody response and of the mixed leukocyte reaction. Suppressors of the adoptive anti-DNP response were eliminated by incubation of spleen cells with anti-Thy-1.2 or anti-thymus-leukemia (TL) antiserum and complement before cell transfer. Thymectomy before TLI prevented the appearance of the latter suppressor cells. On the other hand, suppressors of the MLR were eliminated by incubation of spleen cells with anti-Thy-1.2 but not anti-TL antiserum and complement. Thymectomy before TLI did not prevent their subsequent development. Thus, two subpopulations of suppressor T cells that differ in the expression of the TL surface antigen, dependence on the presence of the thymus, and in regulatory functions develop after TLI. The TL+, thymus-dependent cell suppresses the adoptive antibody response, and the TL-, thymus-independent cell suppresses the MLR

  5. Differential expression of the klf6 tumor suppressor gene upon cell damaging treatments in cancer cells

    International Nuclear Information System (INIS)

    Gehrau, Ricardo C.; D'Astolfo, Diego S.; Andreoli, Veronica; Bocco, Jose L.; Koritschoner, Nicolas P.

    2011-01-01

    The mammalian Krueppel-like factor 6 (KLF6) is involved in critical roles such as growth-related signal transduction, cell proliferation and differentiation, development, apoptosis and angiogenesis. Also, KLF6 appears to be an emerging key factor during cancer development and progression. Its expression is thoroughly regulated by several cell-damaging stimuli. DNA damaging agents at lethal concentrations induce a p53-independent down-regulation of the klf6 gene. To investigate the impact of external stimuli on human klf6 gene expression, its mRNA level was analyzed using a cancer cell line profiling array system, consisting in an assortment of immobilized cDNAs from multiple cell lines treated with several cell-damaging agents at growth inhibitory concentrations (IC 50 ). Cell-damaging agents affected the klf6 expression in 62% of the cDNA samples, though the expression pattern was not dependent on the cell origin type. Interestingly, significant differences (p 50 concentrations of physical and chemical stimuli in a p53-dependent manner. Most of these agents are frequently used in cancer therapy. Induction of klf6 expression in the absence of functional p53 directly correlates with cell death triggered by these compounds, whereas it is down-regulated in p53+/+ cells. Hence, klf6 expression level could represent a valuable marker for the efficiency of cell death upon cancer treatment.

  6. Phytochemical Compositions of Immature Wheat Bran, and Its Antioxidant Capacity, Cell Growth Inhibition, and Apoptosis Induction through Tumor Suppressor Gene

    Directory of Open Access Journals (Sweden)

    Mi Jeong Kim

    2016-09-01

    Full Text Available The purpose of this study was to investigate the phytochemical compositions and antioxidant capacity, cell growth inhibition, and apoptosis induction in extracts of immature wheat bran. Immature wheat bran (IWB was obtained from immature wheat harvested 10 days earlier than mature wheat. The phytochemical compositions of bran extract samples were analyzed by ultra-high performance liquid chromatography. The total ferulic acid (3.09 mg/g and p-coumaric acid (75 µg/g in IWB were significantly higher than in mature wheat bran (MWB, ferulic acid: 1.79 mg/g; p-coumaric acid: 55 µg/g. The oxygen radical absorbance capacity (ORAC: 327 µM Trolox equivalents (TE/g and cellular antioxidant activity (CAA: 4.59 µM Quercetin equivalents (QE/g of the IWB were higher than those of the MWB (ORAC: 281 µM TE/g; CAA: 0.63 µM QE/g. When assessing cell proliferation, the IWB extracts resulted in the lowest EC50 values against HT-29 (18.9 mg/mL, Caco-2 (7.74 mg/mL, and HeLa cells (8.17 mg/mL among bran extract samples. Additionally, the IWB extracts increased the gene expression of p53 and PTEN (tumor suppressor genes in HT-29 cells, indicating inhibited cell growth and induced apoptosis through tumor suppressor genes.

  7. ERK5/BMK1 Is a Novel Target of the Tumor Suppressor VHL: Implication in Clear Cell Renal Carcinoma

    Directory of Open Access Journals (Sweden)

    Laura Arias-González

    2013-06-01

    Full Text Available Extracellular signal-regulated kinase 5 (ERK5, also known as big mitogen-activated protein kinase (MAPK 1, is implicated in a wide range of biologic processes, which include proliferation or vascularization. Here, we show that ERK5 is degraded through the ubiquitin-proteasome system, in a process mediated by the tumor suppressor von Hippel-Lindau (VHL gene, through a prolyl hydroxylation-dependent mechanism. Our conclusions derive from transient transfection assays in Cos7 cells, as well as the study of endogenous ERK5 in different experimental systems such as MCF7, HMEC, or Caki-2 cell lines. In fact, the specific knockdown of ERK5 in pVHL-negative cell lines promotes a decrease in proliferation and migration, supporting the role of this MAPK in cellular transformation. Furthermore, in a short series of fresh samples from human clear cell renal cell carcinoma, high levels of ERK5 correlate with more aggressive and metastatic stages of the disease. Therefore, our results provide new biochemical data suggesting that ERK5 is a novel target of the tumor suppressor VHL, opening a new field of research on the role of ERK5 in renal carcinomas.

  8. Acute Malaria Induces PD1+CTLA4+ Effector T Cells with Cell-Extrinsic Suppressor Function.

    Directory of Open Access Journals (Sweden)

    Maria Sophia Mackroth

    2016-11-01

    Full Text Available In acute Plasmodium falciparum (P. falciparum malaria, the pro- and anti-inflammatory immune pathways must be delicately balanced so that the parasitemia is controlled without inducing immunopathology. An important mechanism to fine-tune T cell responses in the periphery is the induction of coinhibitory receptors such as CTLA4 and PD1. However, their role in acute infections such as P. falciparum malaria remains poorly understood. To test whether coinhibitory receptors modulate CD4+ T cell functions in malaria, blood samples were obtained from patients with acute P. falciparum malaria treated in Germany. Flow cytometric analysis showed a more frequent expression of CTLA4 and PD1 on CD4+ T cells of malaria patients than of healthy control subjects. In vitro stimulation with P. falciparum-infected red blood cells revealed a distinct population of PD1+CTLA4+CD4+ T cells that simultaneously produced IFNγ and IL10. This antigen-specific cytokine production was enhanced by blocking PD1/PDL1 and CTLA4. PD1+CTLA4+CD4+ T cells were further isolated based on surface expression of PD1 and their inhibitory function investigated in-vitro. Isolated PD1+CTLA4+CD4+ T cells suppressed the proliferation of the total CD4+ population in response to anti-CD3/28 and plasmodial antigens in a cell-extrinsic manner. The response to other specific antigens was not suppressed. Thus, acute P. falciparum malaria induces P. falciparum-specific PD1+CTLA4+CD4+ Teffector cells that coproduce IFNγ and IL10, and inhibit other CD4+ T cells. Transient induction of regulatory Teffector cells may be an important mechanism that controls T cell responses and might prevent severe inflammation in patients with malaria and potentially other acute infections.

  9. Allospecific CD8 T suppressor cells induced by multiple MLC stimulation or priming in the presence of ILT3.Fc have similar gene expression profiles.

    Science.gov (United States)

    Chen, Ling; Xu, Zheng; Chang, Chris; Ho, Sophey; Liu, Zhuoru; Vlad, George; Cortesini, Raffaello; Clynes, Raphael A; Luo, Yun; Suciu-Foca, Nicole

    2014-02-01

    Alloantigen specific CD8 T suppressor cells can be generated in vitro either by multiple stimulations of CD3 T cells with allogeneic APC or by single stimulation in primary MLC containing recombinant ILT3.Fc protein. The aim of the present study was to determine whether multiple MLC stimulation induced in CD8(+) CD28(-) T suppressor cells molecular changes that are similar to those observed in CD8 T suppressor cells from primary MLC containing ILT3.Fc protein. Our study demonstrates that the characteristic signatures of CD8 T suppressor cells, generated by either of these methods are the same consisting of up-regulation of the BCL6 transcriptional repressor and down-regulation of inflammatory microRNAs, miR-21, miR-30b, miR-146a, and miR-155 expression. In conclusion microRNAs which are increased under inflammatory conditions in activated CD4 and CD8 T cells with helper or cytotoxic function show low levels of expression in CD8 T cells which have acquired antigen-specific suppressor activity. Copyright © 2014. Published by Elsevier Inc.

  10. Differential expression of the klf6 tumor suppressor gene upon cell damaging treatments in cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Gehrau, Ricardo C.; D' Astolfo, Diego S.; Andreoli, Veronica [Centro de Investigaciones en Bioquimica Clinica e Inmunologia (CIBICI-CONICET), Departamento de Bioquimica Clinica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, 5000 Cordoba (Argentina); Bocco, Jose L., E-mail: jbocco@fcq.unc.edu.ar [Centro de Investigaciones en Bioquimica Clinica e Inmunologia (CIBICI-CONICET), Departamento de Bioquimica Clinica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, 5000 Cordoba (Argentina); Koritschoner, Nicolas P. [Centro de Investigaciones en Bioquimica Clinica e Inmunologia (CIBICI-CONICET), Departamento de Bioquimica Clinica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, 5000 Cordoba (Argentina)

    2011-02-10

    The mammalian Krueppel-like factor 6 (KLF6) is involved in critical roles such as growth-related signal transduction, cell proliferation and differentiation, development, apoptosis and angiogenesis. Also, KLF6 appears to be an emerging key factor during cancer development and progression. Its expression is thoroughly regulated by several cell-damaging stimuli. DNA damaging agents at lethal concentrations induce a p53-independent down-regulation of the klf6 gene. To investigate the impact of external stimuli on human klf6 gene expression, its mRNA level was analyzed using a cancer cell line profiling array system, consisting in an assortment of immobilized cDNAs from multiple cell lines treated with several cell-damaging agents at growth inhibitory concentrations (IC{sub 50}). Cell-damaging agents affected the klf6 expression in 62% of the cDNA samples, though the expression pattern was not dependent on the cell origin type. Interestingly, significant differences (p < 0.0001) in KLF6 mRNA levels were observed depending on the cellular p53 status upon cell damage. KLF6 expression was significantly increased in 63% of p53-deficient cells (122/195). Conversely, KLF6 mRNA level decreased nearly 4 fold in more than 70% of p53+/+ cells. In addition, klf6 gene promoter activity was down-regulated by DNA damaging agents in cells expressing the functional p53 protein whereas it was moderately increased in the absence of functional p53. Consistent results were obtained for the endogenous KLF6 protein level. Results indicate that human klf6 gene expression is responsive to external cell damage mediated by IC{sub 50} concentrations of physical and chemical stimuli in a p53-dependent manner. Most of these agents are frequently used in cancer therapy. Induction of klf6 expression in the absence of functional p53 directly correlates with cell death triggered by these compounds, whereas it is down-regulated in p53+/+ cells. Hence, klf6 expression level could represent a valuable

  11. Effect of recombinant adenovirus encoding human p53 tumor suppressor gene combined with radiation therapy on human lymphoma cells lines

    International Nuclear Information System (INIS)

    Yu Zeyang; Fan Wo; Li Dongqing; Zhu Ran; Wan Jianmei; Wang Yongqing; Wu Jinchang

    2008-01-01

    This paper analyzes the inhibitory effect and radiation sensitization of recombinant adenovirus encoding human p53 tumor suppressor gene (rAd-p53) on human lymphoma cell lines. Human lymphoma cell lines were treated with rAd-p53, radiation therapy and combined treatment, respectively. The cell growth inhibition was assessed by MTF. The cell cycle and apoptosis were detected by flow cytometry, and the p53 protein expression was detected by Western blotting. The results showed that extrinsic p53 gene have expressed to some degree, but not at high level. The role of inhibition and radiation sensitivity of rAd-p53 was not significant to human lymphoma cell lines. (authors)

  12. Cholesterol and phytosterols differentially regulate the expression of caveolin 1 and a downstream prostate cell growth-suppressor gene

    Science.gov (United States)

    Ifere, Godwin O.; Equan, Anita; Gordon, Kereen; Nagappan, Peri; Igietseme, Joseph U.; Ananaba, Godwin A.

    2010-01-01

    Background The purpose of our study was to show the distinction between the apoptotic and anti-proliferative signaling of phytosterols and cholesterol enrichment in prostate cancer cell lines, mediated by the differential transcription of caveolin-1, and N-myc downstream regulated gene1 (NDRG1), a pro-apoptotic androgen-regulated tumor suppressor. Methods PC-3 and DU145 cells were treated with sterols (cholesterol and phytosterols) for 72 h, followed by trypan blue dye exclusion measurement of necrosis and cell growth measured with a Coulter counter. Sterol induction of cell growth-suppressor gene expression was evaluated by mRNA transcription using RT-PCR, while cell cycle analysis was performed by FACS analysis. Altered expression of Ndrg1 protein was confirmed by Western blot analysis. Apoptosis was evaluated by real time RT-PCR amplification of P53, Bcl-2 gene and its related pro- and anti-apoptotic family members. Results Physiological doses (16 µM) of cholesterol and phytosterols were not cytotoxic in these cells. Cholesterol enrichment promoted cell growth (Pphytosterols significantly induced growth-suppression (Pphytosterols decreased mitotic subpopulations. We demonstrated for the first time that cholesterols concertedly attenuated the expression of caveolin-1(cav-1) and NDRG1 genes in both prostate cancer cell lines. Phytosterols had the opposite effect by inducing overexpression of cav-1, a known mediator of androgen-dependent signals that presumably control cell growth or apoptosis. Conclusions Cholesterol and phytosterol treatment differentially regulated the growth of prostate cancer cells and the expression of p53 and cav-1, a gene that regulates androgen-regulated signals. These sterols also differentially regulated cell cycle arrest, downstream pro-apoptotic androgen-regulated tumor-suppressor, NDRG1 suggesting that cav-1 may mediate pro-apoptotic NDRG1 signals. Elucidation of the mechanism for sterol modulation of growth and apoptosis signaling

  13. Nuclear location of tumor suppressor protein maspin inhibits proliferation of breast cancer cells without affecting proliferation of normal epithelial cells

    International Nuclear Information System (INIS)

    Machowska, Magdalena; Wachowicz, Katarzyna; Sopel, Mirosław; Rzepecki, Ryszard

    2014-01-01

    Maspin, which is classified as a tumor suppressor protein, is downregulated in many types of cancer. Several studies have suggested potential anti-proliferative activity of maspin as well as sensitizing activity of maspin for therapeutic cytotoxic agents in breast cancer tissue culture and animal models. All of the experimental data gathered so far have been based on studies with maspin localized cytoplasmically, while maspin in breast cancer tumor cells may be located in the cytoplasm, nucleus or both. In this study, the effect of maspin cytoplasmic and nuclear location and expression level on breast cancer proliferation and patient survival was studied. Tissue sections from 166 patients with invasive ductal breast cancer were stained by immunohistochemistry for maspin and Ki-67 protein. The localization and expression level of maspin were correlated with estimated patient overall survival and percent of Ki-67-positive cells. In further studies, we created constructs for transient transfection of maspin into breast cancer cells with targeted cytoplasmic and nuclear location. We analyzed the effect of maspin location in normal epithelial cell line MCF10A and three breast cancer cell lines - MCF-7, MDA-MB-231 and SKBR-3 - by immunofluorescence and proliferation assay. We observed a strong positive correlation between moderate and high nuclear maspin level and survival of patients. Moreover, a statistically significant negative relationship was observed between nuclear maspin and Ki-67 expression in patients with invasive ductal breast cancer. Spearman’s correlation analysis showed a negative correlation between level of maspin localized in nucleus and percentage of Ki-67 positive cells. No such differences were observed in cells with cytoplasmic maspin. We found a strong correlation between nuclear maspin and loss of Ki-67 protein in breast cancer cell lines, while there was no effect in normal epithelial cells from breast. The anti-proliferative effect of nuclear

  14. Nuclear location of tumor suppressor protein maspin inhibits proliferation of breast cancer cells without affecting proliferation of normal epithelial cells

    Science.gov (United States)

    2014-01-01

    Background Maspin, which is classified as a tumor suppressor protein, is downregulated in many types of cancer. Several studies have suggested potential anti-proliferative activity of maspin as well as sensitizing activity of maspin for therapeutic cytotoxic agents in breast cancer tissue culture and animal models. All of the experimental data gathered so far have been based on studies with maspin localized cytoplasmically, while maspin in breast cancer tumor cells may be located in the cytoplasm, nucleus or both. In this study, the effect of maspin cytoplasmic and nuclear location and expression level on breast cancer proliferation and patient survival was studied. Methods Tissue sections from 166 patients with invasive ductal breast cancer were stained by immunohistochemistry for maspin and Ki-67 protein. The localization and expression level of maspin were correlated with estimated patient overall survival and percent of Ki-67-positive cells. In further studies, we created constructs for transient transfection of maspin into breast cancer cells with targeted cytoplasmic and nuclear location. We analyzed the effect of maspin location in normal epithelial cell line MCF10A and three breast cancer cell lines - MCF-7, MDA-MB-231 and SKBR-3 - by immunofluorescence and proliferation assay. Results We observed a strong positive correlation between moderate and high nuclear maspin level and survival of patients. Moreover, a statistically significant negative relationship was observed between nuclear maspin and Ki-67 expression in patients with invasive ductal breast cancer. Spearman’s correlation analysis showed a negative correlation between level of maspin localized in nucleus and percentage of Ki-67 positive cells. No such differences were observed in cells with cytoplasmic maspin. We found a strong correlation between nuclear maspin and loss of Ki-67 protein in breast cancer cell lines, while there was no effect in normal epithelial cells from breast. The anti

  15. Human umbilical cord matrix mesenchymal stem cells suppress the growth of breast cancer by expression of tumor suppressor genes.

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    Naomi Ohta

    Full Text Available Human and rat umbilical cord matrix mesenchymal stem cells (UCMSC possess the ability to control the growth of breast carcinoma cells. Comparative analyses of two types of UCMSC suggest that rat UCMSC-dependent growth regulation is significantly stronger than that of human UCMSC. Their different tumoricidal abilities were clarified by analyzing gene expression profiles in the two types of UCMSC. Microarray analysis revealed differential gene expression between untreated naïve UCMSC and those co-cultured with species-matched breast carcinoma cells. The analyses screened 17 differentially expressed genes that are commonly detected in both human and rat UCMSC. The comparison between the two sets of gene expression profiles identified two tumor suppressor genes, adipose-differentiation related protein (ADRP and follistatin (FST, that were specifically up-regulated in rat UCMSC, but down-regulated in human UCMSC when they were co-cultured with the corresponding species' breast carcinoma cells. Over-expression of FST, but not ADRP, in human UCMSC enhanced their ability to suppress the growth of MDA-231 cells. The growth of MDA-231 cells was also significantly lower when they were cultured in medium conditioned with FST, but not ADRP over-expressing human UCMSC. In the breast carcinoma lung metastasis model generated with MDA-231 cells, systemic treatment with FST-over-expressing human UCMSC significantly attenuated the tumor burden. These results suggest that FST may play an important role in exhibiting stronger tumoricidal ability in rat UCMSC than human UCMSC and also implies that human UCMSC can be transformed into stronger tumoricidal cells by enhancing tumor suppressor gene expression.

  16. IFN regulatory factor 8 represses GM-CSF expression in T cells to affect myeloid cell lineage differentiation.

    Science.gov (United States)

    Paschall, Amy V; Zhang, Ruihua; Qi, Chen-Feng; Bardhan, Kankana; Peng, Liang; Lu, Geming; Yang, Jianjun; Merad, Miriam; McGaha, Tracy; Zhou, Gang; Mellor, Andrew; Abrams, Scott I; Morse, Herbert C; Ozato, Keiko; Xiong, Huabao; Liu, Kebin

    2015-03-01

    During hematopoiesis, hematopoietic stem cells constantly differentiate into granulocytes and macrophages via a distinct differentiation program that is tightly controlled by myeloid lineage-specific transcription factors. Mice with a null mutation of IFN regulatory factor 8 (IRF8) accumulate CD11b(+)Gr1(+) myeloid cells that phenotypically and functionally resemble tumor-induced myeloid-derived suppressor cells (MDSCs), indicating an essential role of IRF8 in myeloid cell lineage differentiation. However, IRF8 is expressed in various types of immune cells, and whether IRF8 functions intrinsically or extrinsically in regulation of myeloid cell lineage differentiation is not fully understood. In this study, we report an intriguing finding that, although IRF8-deficient mice exhibit deregulated myeloid cell differentiation and resultant accumulation of CD11b(+)Gr1(+) MDSCs, surprisingly, mice with IRF8 deficiency only in myeloid cells exhibit no abnormal myeloid cell lineage differentiation. Instead, mice with IRF8 deficiency only in T cells exhibited deregulated myeloid cell differentiation and MDSC accumulation. We further demonstrated that IRF8-deficient T cells exhibit elevated GM-CSF expression and secretion. Treatment of mice with GM-CSF increased MDSC accumulation, and adoptive transfer of IRF8-deficient T cells, but not GM-CSF-deficient T cells, increased MDSC accumulation in the recipient chimeric mice. Moreover, overexpression of IRF8 decreased GM-CSF expression in T cells. Our data determine that, in addition to its intrinsic function as an apoptosis regulator in myeloid cells, IRF8 also acts extrinsically to repress GM-CSF expression in T cells to control myeloid cell lineage differentiation, revealing a novel mechanism that the adaptive immune component of the immune system regulates the innate immune cell myelopoiesis in vivo. Copyright © 2015 by The American Association of Immunologists, Inc.

  17. Neutrophils and Granulocytic MDSC: The Janus God of Cancer Immunotherapy

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    Serena Zilio

    2016-09-01

    Full Text Available Neutrophils are the most abundant circulating blood cell type in humans, and are the first white blood cells recruited at the inflammation site where they orchestrate the initial immune response. Although their presence at the tumor site was recognized in the 1970s, until recently these cells have been neglected and considered to play just a neutral role in tumor progression. Indeed, in recent years neutrophils have been recognized to play a dual role in tumor development by either assisting the growth, angiogenesis, invasion, and metastasis or by exerting tumoricidal action directly via the secretion of antitumoral compounds, or indirectly via the orchestration of antitumor immunity. Understanding the biology of these cells and influencing their polarization in the tumor micro- and macro-environment may be the key for the development of new therapeutic strategies, which may finally hold the promise of an effective immunotherapy for cancer.

  18. Hypermethylation of the 16q23.1 Tumor Suppressor Gene ADAMTS18 in Clear Cell Renal Cell Carcinoma

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    Ben Xu

    2015-01-01

    Full Text Available To identify tumor suppressor genes (TSGs silenced by hypermethylation and discover new epigenetic biomarkers for early cancer detection. ADAMTS18, located at 16q23.1, has been reported to be a critical TSG in multiple primary tumors; however, this has not yet been verified in clear cell renal cell carcinoma (ccRCC. We explored epigenetic alterations in this gene in ccRCC and analyzed possible clinicopathological associations. We examined ADAMTS18 gene expression and methylation by semi-quantitative reverse transcription PCR (RT-PCR and methylation-specific polymerase chain reaction (MSP in 5 ccRCC-derived cell lines before and after treatment with 5-aza-2'-deoxycytidine (5-AzaC. MSP was further performed for 101 ccRCC primary tumors and 20 adjacent normal tissues. Some cell lines and specimens were examined by subsequent bisulfite genomic sequencing (BGS and real-time PCR. Further, we analyzed the relationship between the ADAMTS18 gene methylation and clinicopathological features, including short-term disease-free survival (DFS, in patients with ccRCC. ADAMTS18 down-regulation and hypermethylation were detected in the ccRCC-derived cell lines using RT-PCR and MSP. Treatment with 5-AzaC reversed the hypermethylation of the ADAMTS18 gene and restored its expression. Hypermethylation was further detected in 44 of 101 (43.6% primary tumors and 3 of 20 (15.0% adjacent normal tissues. However, a significant difference between both groups was observed (p = 0.02. BGS analysis and real-time PCR were subsequently performed to confirm the results of RT-PCR and MSP. Furthermore, the methylation status of ADAMTS18 was not significantly associated with gender, age, location, tumor diameter, pathological stage, nuclear grade or short-term DFS in patients with ccRCC (p > 0.05. The ADAMTS18 gene is often down-regulated by hypermethylation in ccRCC-derived cell lines and primary tumors, indicating its critical role as a TSG in ccRCC. We conclude that ADAMTS18

  19. Protocadherin-10 acts as a tumor suppressor gene, and is frequently downregulated by promoter methylation in pancreatic cancer cells.

    Science.gov (United States)

    Qiu, Chan; Bu, Xiaona; Jiang, Zheng

    2016-07-01

    Protocadherin-10 (PCDH10), a member of non-clustered protocadherin family which plays important roles in calcium-dependent cell-cell signal transduction and adhesion. PCDH10 functions as a tumor suppressor gene and its expression is downregulated by promoter methylation in many malignances. In the present study, we explored PCDH10 expression and promoter methylation status, and its biological effects in pancreatic cancer cells, and furthermore, we explored the mechanism of PCDH10 preliminary in pancreatic cancer cells. the mRNA level of PCDH10 was detected by semi-quantitative reverse transcription PCR and promoter methylation status examined by methylation-specific PCR in the pancreatic cancer cells (Capan-1, Panc-1, AsPC-1 and BxPC-3) as well as the human normal pancreatic ductal epithelial cells HPDE6-C7 which was used as a control. The human pancreatic cells were transfected with plasmid pcDNA3.1-PCDH10 or pcDNA3.1 by lipofectamine 2000. The biological function of PCDH10 in pancreatic cancer cells was determined by CCK-8 assay, colony formation assay, flow cytometry, Transwell invasion assay and wound-healing assay. The levels of apoptosis related proteins were examined by western blotting. PCDH10 expression was obviously downregulated in the pancreatic cancer cells (Capan-1, Panc-1, BxPC-3) compared to the normal pancreatic ductal epithelial cells. PCDH10 promoter methylation was observed in the two pancreatic cancer cells Capan-1 and BxPC-3,and the expression of PCDH10 could be restored after treating with 5-aza-2'-deoxycytidine and trichostatin A in the two cell types. Overexpression of PCDH10 can inhibit the proliferation, migration, invasion ability of pancreatic cancer cells and induce apoptosis. Ectopic expression of PCDH10 could increase the levels of PARP, caspase-3, caspase-9 and decrease the level of bcl-2, AKT and p-AKT. PCDH10 acts as a tumor suppressor gene, and is frequently down-regulated by promoter methylation in pancreatic cancer cells. PCDH

  20. Phenotypic and functional characteristics of active suppressor cells against IFN-gamma production in PHA-stimulated cord blood lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Seki, H.; Taga, K.; Matsuda, A.; Uwadana, N.; Hasui, M.; Miyawaki, T.; Taniguchi, N.

    1986-11-15

    Cord blood mononuclear cells (MNC) were defective in their ability to produce interferon-gamma (IFN-gamma) on stimulation with phytohemagglutinin (PHA) or recombinant interleukin 2, whereas cord MNC could induce comparable amounts of IFN-gamma with adult controls on stimulation with a streptococcal preparation, OK-432. Moreover, irradiation of cord MNC with 1500 rad before PHA stimulation could restore the IFN-gamma production. Kinetic studies indicated that such augmentation of IFN-gamma production by irradiation was evident when cord MNC were irradiated before or by 12 hr of PHA-stimulated culture. But irradiation after 18 hr or more of PHA stimulation did not exert any significant augmentation on IFN-gamma production by cord MNC. It seemed most likely that the ability of IFN-gamma production is already mature at birth, but radiosensitive suppressor effectors on IFN-gamma production are activated within cord MNC at an early stage of PHA stimulation, resulting in poor IFN-gamma production by cord MNC. PHA-induced IFN-gamma production by OKT3+, OKT4+, and OKT8- cord cells were markedly enhanced by irradiation with 1,500 rad before the culture. Coculture experiments disclosed that cord OKT4+ cells, but not OKT4- cells, when prestimulated with PHA for 24 hr, exerted active suppression on PHA-induced IFN-gamma production by adult MNC in a dose-dependent manner. These results suggested that radiosensitive suppressor effectors on IFN-gamma production were induced within the OKT4+ T cell subset of cord MNC on PHA stimulation.

  1. Tumor suppressor KAI1 affects integrin αvβ3-mediated ovarian cancer cell adhesion, motility, and proliferation

    International Nuclear Information System (INIS)

    Ruseva, Zlatna; Geiger, Pamina Xenia Charlotte; Hutzler, Peter; Kotzsch, Matthias; Luber, Birgit; Schmitt, Manfred; Gross, Eva; Reuning, Ute

    2009-01-01

    The tetraspanin KAI1 had been described as a metastasis suppressor in many different cancer types, a function for which associations of KAI1 with adhesion and signaling receptors of the integrin superfamily likely play a role. In ovarian cancer, integrin αvβ3 correlates with tumor progression and its elevation in vitro provoked enhanced cell adhesion accompanied by significant increases in cell motility and proliferation in the presence of its major ligand vitronectin. In the present study, we characterized integrin αvβ3-mediated tumor biological effects as a function of cellular KAI1 restoration and proved for the first time that KAI1, besides its already known physical crosstalk with β1-integrins, also colocalizes with integrin αvβ3. Functionally, elevated KAI1 levels drastically increased integrin αvβ3/vitronectin-dependent ovarian cancer cell adhesion. Since an intermediate level of cell adhesive strength is required for optimal cell migration, we next studied ovarian cancer cell motility as a function of KAI1 restoration. By time lapse video microscopy, we found impaired integrin αvβ3/vitronectin-mediated cell migration most probably due to strongly enhanced cellular immobilization onto the adhesion-supporting matrix. Moreover, KAI1 reexpression significantly diminished cell proliferation. These data strongly indicate that KAI1 may suppress ovarian cancer progression by inhibiting integrin αvβ3/vitronectin-provoked tumor cell motility and proliferation as important hallmarks of the oncogenic process.

  2. Senescence-Associated Secretory Phenotypes Reveal Cell-Nonautonomous Functions of Oncogenic RAS and the p53 Tumor Suppressor

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    Copp& #233; , Jean-Philippe; Patil, Christopher; Rodier, Francis; Sun, Yu; Munoz, Denise; Goldstein, Joshua; Nelson, Peter; Desprez, Pierre-Yves; Campisi, Judith

    2008-10-24

    Cellular senescence suppresses cancer by arresting cell proliferation, essentially permanently, in response to oncogenic stimuli, including genotoxic stress. We modified the use of antibody arrays to provide a quantitative assessment of factors secreted by senescent cells. We show that human cells induced to senesce by genotoxic stress secrete myriad factors associated with inflammation and malignancy. This senescence-associated secretory phenotype (SASP) developed slowly over several days and only after DNA damage of sufficient magnitude to induce senescence. Remarkably similar SASPs developed in normal fibroblasts, normal epithelial cells, and epithelial tumor cells after genotoxic stress in culture, and in epithelial tumor cells in vivo after treatment of prostate cancer patients with DNA-damaging chemotherapy. In cultured premalignant epithelial cells, SASPs induced an epithelial-mesenchyme transition and invasiveness, hallmarks of malignancy, by a paracrine mechanism that depended largely on the SASP factors interleukin (IL)-6 and IL-8. Strikingly, two manipulations markedly amplified, and accelerated development of, the SASPs: oncogenic RAS expression, which causes genotoxic stress and senescence in normal cells, and functional loss of the p53 tumor suppressor protein. Both loss of p53 and gain of oncogenic RAS also exacerbated the promalignant paracrine activities of the SASPs. Our findings define a central feature of genotoxic stress-induced senescence. Moreover, they suggest a cell-nonautonomous mechanism by which p53 can restrain, and oncogenic RAS can promote, the development of age-related cancer by altering the tissue microenvironment.

  3. NBPF1, a tumor suppressor candidate in neuroblastoma, exerts growth inhibitory effects by inducing a G1 cell cycle arrest

    International Nuclear Information System (INIS)

    Andries, Vanessa; Vandepoele, Karl; Staes, Katrien; Berx, Geert; Bogaert, Pieter; Van Isterdael, Gert; Ginneberge, Daisy; Parthoens, Eef; Vandenbussche, Jonathan; Gevaert, Kris; Roy, Frans van

    2015-01-01

    NBPF1 (Neuroblastoma Breakpoint Family, member 1) was originally identified in a neuroblastoma patient on the basis of its disruption by a chromosomal translocation t(1;17)(p36.2;q11.2). Considering this genetic defect and the frequent genomic alterations of the NBPF1 locus in several cancer types, we hypothesized that NBPF1 is a tumor suppressor. Decreased expression of NBPF1 in neuroblastoma cell lines with loss of 1p36 heterozygosity and the marked decrease of anchorage-independent clonal growth of DLD1 colorectal carcinoma cells with induced NBPF1 expression further suggest that NBPF1 functions as tumor suppressor. However, little is known about the mechanisms involved. Expression of NBPF was analyzed in human skin and human cervix by immunohistochemistry. The effects of NBPF1 on the cell cycle were evaluated by flow cytometry. We investigated by real-time quantitative RT-PCR the expression profile of a panel of genes important in cell cycle regulation. Protein levels of CDKN1A-encoded p21 CIP1/WAF1 were determined by western blotting and the importance of p53 was shown by immunofluorescence and by a loss-of-function approach. LC-MS/MS analysis was used to investigate the proteome of DLD1 colon cancer cells with induced NBPF1 expression. Possible biological interactions between the differentially regulated proteins were investigated with the Ingenuity Pathway Analysis tool. We show that NBPF is expressed in the non-proliferative suprabasal layers of squamous stratified epithelia of human skin and cervix. Forced expression of NBPF1 in HEK293T cells resulted in a G1 cell cycle arrest that was accompanied by upregulation of the cyclin-dependent kinase inhibitor p21 CIP1/WAF1 in a p53-dependent manner. Additionally, forced expression of NBPF1 in two p53-mutant neuroblastoma cell lines also resulted in a G1 cell cycle arrest and CDKN1A upregulation. However, CDKN1A upregulation by NBPF1 was not observed in the DLD1 cells, which demonstrates that NBPF1 exerts cell

  4. Retinoid-induced expression and activity of an immediate early tumor suppressor gene in vascular smooth muscle cells.

    Directory of Open Access Journals (Sweden)

    Jeffrey W Streb

    2011-04-01

    Full Text Available Retinoids are used clinically to treat a number of hyper-proliferative disorders and have been shown in experimental animals to attenuate vascular occlusive diseases, presumably through nuclear receptors bound to retinoic acid response elements (RARE located in target genes. Here, we show that natural or synthetic retinoids rapidly induce mRNA and protein expression of a specific isoform of A-Kinase Anchoring Protein 12 (AKAP12β in cultured smooth muscle cells (SMC as well as the intact vessel wall. Expression kinetics and actinomycin D studies indicate Akap12β is a retinoid-induced, immediate-early gene. Akap12β promoter analyses reveal a conserved RARE mildly induced with atRA in a region that exhibits hyper-acetylation. Immunofluorescence microscopy and protein kinase A (PKA regulatory subunit overlay assays in SMC suggest a physical association between AKAP12β and PKA following retinoid treatment. Consistent with its designation as a tumor suppressor, inducible expression of AKAP12β attenuates SMC growth in vitro. Further, immunohistochemistry studies establish marked decreases in AKAP12 expression in experimentally-injured vessels of mice as well as atheromatous lesions in humans. Collectively, these results demonstrate a novel role for retinoids in the induction of an AKAP tumor suppressor that blocks vascular SMC growth thus providing new molecular insight into how retiniods may exert their anti-proliferative effects in the injured vessel wall.

  5. ING Genes Work as Tumor Suppressor Genes in the Carcinogenesis of Head and Neck Squamous Cell Carcinoma

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    Xiaohan Li

    2011-01-01

    Full Text Available Head and neck squamous cell carcinoma (HNSCC is the sixth most common cancer in the world. The evolution and progression of HNSCC are considered to result from multiple stepwise alterations of cellular and molecular pathways in squamous epithelium. Recently, inhibitor of growth gene (ING family consisting of five genes, ING1 to ING5, was identified as a new tumor suppressor gene family that was implicated in the downregulation of cell cycle and chromatin remodeling. In contrast, it has been shown that ING1 and ING2 play an oncogenic role in some cancers, this situation being similar to TGF-β. In HNSCC, the ING family has been reported to be downregulated, and ING translocation from the nucleus to the cytoplasm may be a critical event for carcinogenesis. In this paper, we describe our recent results and briefly summarize current knowledge regarding the biologic functions of ING in HNSCC.

  6. Antihelminthic drug niclosamide inhibits CIP2A and reactivates tumor suppressor protein phosphatase 2A in non-small cell lung cancer cells.

    Science.gov (United States)

    Kim, Myeong-Ok; Choe, Min Ho; Yoon, Yi Na; Ahn, Jiyeon; Yoo, Minjin; Jung, Kwan-Young; An, Sungkwan; Hwang, Sang-Gu; Oh, Jeong Su; Kim, Jae-Sung

    2017-11-15

    Protein phosphatase 2A (PP2A) is a critical tumor suppressor complex responsible for the inactivation of various oncogenes. Recently, PP2A reactivation has emerged asan anticancer strategy. Cancerous inhibitor of protein phosphatase 2A (CIP2A), an endogenous inhibitor of PP2A, is upregulated in many cancer cells, including non-small cell lung cancer (NSCLC) cells. We demonstrated that the antihelminthic drug niclosamide inhibited the expression of CIP2A and reactivated the tumor suppressor PP2A in NSCLC cells. We performed a drug-repurposing screen and identified niclosamide asa CIP2A suppressor in NSCLC cells. Niclosamide inhibited cell proliferation, colony formation, and tumor sphere formation, and induced mitochondrial dysfunction through increased mitochondrial ROS production in NSCLC cells; however, these effects were rescued by CIP2A overexpression, which indicated that the antitumor activity of niclosamide was dependent on CIP2A. We found that niclosamide increased PP2A activity through CIP2A inhibition, which reduced the phosphorylation of several oncogenic proteins. Moreover, we found that a niclosamide analog inhibited CIP2A expression and increased PP2A activity in several types of NSCLC cells. Finally, we showed that other well-known PP2A activators, including forskolin and FTY720, did not inhibit CIP2A and that their activities were not dependent on CIP2A. Collectively, our data suggested that niclosamide effectively suppressed CIP2A expression and subsequently activated PP2A in NSCLC cells. This provided strong evidence for the potential use of niclosamide asa PP2A-activating drug in the clinical treatment of NSCLC. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Wolf–Hirschhorn Syndrome Candidate 1 (whsc1 Functions as a Tumor Suppressor by Governing Cell Differentiation

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    Chuan Yu

    2017-08-01

    Full Text Available Wolf–Hirschhorn syndrome candidate 1 (WHSC1 is a histone 3 lysine 36 (H3K36 specific methyltransferase that is frequently deleted in Wolf–Hirschhorn syndrome (WHS. Whsc1 is also found mutated in a subgroup of B-cell derived malignant diseases by genomic translocation or point mutation, both of which resulted in hyperactivity of WHSC1 mediated H3K36 methylation and uncontrolled cell proliferation, suggesting that whsc1 functions as an oncogene. However, here we provided evidences to show that whsc1 also has tumor suppressor functions. We used zebrafish as an in vivo model and generated homozygous whsc1 mutant lines via clustered regularly interspaced short palindromic repeats-associated protein Cas9 (CRISPR/Cas9 technology. Then western-blot (WB and immunofluorescence (IF were performed to analysis the expression level of H3K36Me2 and H3K36Me3, and we identified the diseased tissue via hematoxylin–eosin (HE staining, IF staining or immunohistochemistry (IHC. Whsc1 lose-of-function led to significant decrease in di- and tri-methylation of H3K36. A series of WHS related phenotypes were found in whsc1−/− zebrafish, including growth retardation, neural development defects and heart failure. In addition, loss of function of whsc1 led to defects in the development of swim bladder, possibly through the dis-regulation of key genes in swim bladder organogenesis and inhibition of progenitor cell differentiation, which was correlated with its expression in this organ during embryonic development. At later stage, these whsc1−/− zebrafishes are inclined to grow tumors in the swim bladder. Our work suggested that whsc1 may function as a tumor suppressor by governing progenitor cell differentiation.

  8. Screening of amber suppressor tRNAs suitable to introduce nonnatural amino acids into proteins by real-time monitoring of cell-free translation.

    Science.gov (United States)

    Iijima, Issei; Hohsaka, Takahiro

    2009-01-01

    Incorporation of nonnatural amino acids into proteins is a useful technique to analyze protein structure and function. We have reported that amber suppressor tRNAs suitable for efficient and specific incorporation of nonnatural amino acids into proteins can be obtained by screening a wide variety of naturally occurring tRNAs in an E. coli. cell-free translation system. The amber suppressor activity of the tRNAs was evaluated by incorporation of a fluorescent nonnatural amino acid and fluorescent SDS-PAGE analysis of cell-free translation products, though the SDS-PAGE was troublesome and time-consuming. In this research, we developed an alternative method for the screening of amber suppressor tRNAs by real-time measurement of fluorescence resonance energy transfer (FRET) from GFP to BODIPY558-linked nonnatural amino acid, which was incorporated into the N-terminus of GFP by amber suppressor tRNAs. Using this method, we demonstrated that the screening of the amber suppressor activity of various prokaryotic Trp tRNAs was performed in a high-throughput manner.

  9. Mesenchymal Transition of High-Grade Breast Carcinomas Depends on Extracellular Matrix Control of Myeloid Suppressor Cell Activity.

    Science.gov (United States)

    Sangaletti, Sabina; Tripodo, Claudio; Santangelo, Alessandra; Castioni, Nadia; Portararo, Paola; Gulino, Alessandro; Botti, Laura; Parenza, Mariella; Cappetti, Barbara; Orlandi, Rosaria; Tagliabue, Elda; Chiodoni, Claudia; Colombo, Mario P

    2016-09-27

    The extracellular matrix (ECM) contributes to the biological and clinical heterogeneity of breast cancer, and different prognostic groups can be identified according to specific ECM signatures. In high-grade, but not low-grade, tumors, an ECM signature characterized by high SPARC expression (ECM3) identifies tumors with increased epithelial-to-mesenchymal transition (EMT), reduced treatment response, and poor prognosis. To better understand how this ECM3 signature is contributing to tumorigenesis, we expressed SPARC in isogenic cell lines and found that SPARC overexpression in tumor cells reduces their growth rate and induces EMT. SPARC expression also results in the formation of a highly immunosuppressive microenvironment, composed by infiltrating T regulatory cells, mast cells, and myeloid-derived suppressor cells (MDSCs). The ability of SPARC to induce EMT depended on the localization and suppressive function of myeloid cells, and inhibition of the suppressive function MDSCs by administration of aminobisphosphonates could revert EMT, rendering SPARC-overexpressing tumor cells sensitive to Doxil. We conclude that that SPARC is regulating the interplay between MDSCs and the ECM to drive the induction of EMT in tumor cells. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  10. PHTS, a novel putative tumor suppressor, is involved in the transformation reversion of HeLaHF cells independently of the p53 pathway

    International Nuclear Information System (INIS)

    Yu Dehua; Fan, Wufang; Liu, Guohong; Nguy, Vivian; Chatterton, Jon E.; Long Shilong; Ke, Ning; Meyhack, Bernd; Bruengger, Adrian; Brachat, Arndt; Wong-Staal, Flossie; Li, Qi-Xiang

    2006-01-01

    HeLaHF is a non-transformed revertant of HeLa cells, likely resulting from the activation of a putative tumor suppressor(s). p53 protein was stabilized in this revertant and reactivated for certain transactivation functions. Although p53 stabilization has not conclusively been linked to the reversion, it is clear that the genes in p53 pathway are involved. The present study confirms the direct role of p53 in HeLaHF reversion by demonstrating that RNAi-mediated p53 silencing partially restores anchorage-independent growth potential of the revertant through the suppression of anoikis. In addition, we identified a novel gene, named PHTS, with putative tumor suppressor properties, and showed that this gene is also involved in HeLaHF reversion independently of the p53 pathway. Expression profiling revealed that PHTS is one of the genes that is up-regulated in HeLaHF but not in HeLa. It encodes a putative protein with CD59-like domains. RNAi-mediated PHTS silencing resulted in the partial restoration of transformation (anchorage-independent growth) in HeLaHF cells, similar to that of p53 gene silencing, implying its tumor suppressor effect. However, the observed increased transformation potential by PHTS silencing appears to be due to an increased anchorage-independent proliferation rate rather than suppression of anoikis, unlike the effect of p53 silencing. p53 silencing did not affect PHTS gene expression, and vice versa, suggesting PHTS may function in a new and p53-independent tumor suppressor pathway. Furthermore, over-expression of PHTS in different cancer cell lines, in addition to HeLa, reduces cell growth likely via induced apoptosis, confirming the broad PHTS tumor suppressor properties

  11. Candidate tumour suppressor CCDC19 regulates miR-184 direct targeting of C-Myc thereby suppressing cell growth in non-small cell lung cancers.

    Science.gov (United States)

    Liu, Zhen; Mai, Chunping; Yang, Huiling; Zhen, Yan; Yu, Xiaoli; Hua, Shengni; Wu, Qiangyun; Jiang, Qinping; Zhang, Yajie; Song, Xin; Fang, Weiyi

    2014-08-01

    We previously reported and revised the nasopharyngeal epithelium specific protein CCDC19 and identified it as a potential tumour suppressor in nasopharyngeal carcinoma. The purpose of this study was to investigate the involvement of CCDC19 in the pathogenesis of human non-small cell lung cancers (NSCLC). Down-regulated CCDC19 expression was observed in NSCLC tissues and cells compared to normal tissues. However, reduced protein expression did not correlate with the status of NSCLC progression. Instead, we observed that patients with lower CCDC19 expression had a shorter overall survival than did patients with higher CCDC19 expression. Lentiviral-mediated CCDC19 overexpression significantly suppressed cell proliferation and cell cycle transition from G1 to S and G2 phases in NSCLC cells. Knocking down CCDC19 expression significantly restored the ability of cell growth in CCDC19 overexpressing NSCLC cells. Mechanistically CCDC19 functions as a potential tumour suppressor by stimulating miR-184 suppression of C-Myc thus blocking cell growth mediated by the PI3K/AKT/C-Jun pathway. Our studies are the first to demonstrate that reduced expression of CCDC19 is an unfavourable factor in NSCLC. © 2014 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  12. Re-expression of methylation-induced tumor suppressor gene silencing is associated with the state of histone modification in gastric cancer cell lines

    OpenAIRE

    Meng, Chun-Feng; Zhu, Xin-Jiang; Peng, Guo; Dai, Dong-Qiu

    2007-01-01

    AIM: To identify the relationship between DNA hyper-methylation and histone modification at a hyperme-thylated, silenced tumor suppressor gene promoter in human gastric cancer cell lines and to elucidate whether alteration of DNA methylation could affect histone modification.

  13. Suppressor T cells, distinct from "veto cells," are induced by alloantigen priming and mediate transferable suppression of cytotoxic T lymphocyte responses in vivo

    DEFF Research Database (Denmark)

    Owens, T; Crispe, I N

    1985-01-01

    Primary and secondary cytotoxic T lymphocyte responses to minor alloantigens can be suppressed by priming host mice with a high dose (10(8) cells) of alloantigenic donor spleen cells (SC). Such suppression is antigen specific and transferable into secondary hosts with T cells. One interpretation...... of this is that antigen-specific host suppressor T cells (Ts) are activated. Alternatively, donor Lyt-2+ T cells, introduced in the priming inoculum, may inactivate host CTL precursors (CTLp) that recognize the priming (donor) alloantigens. Donor cells that act in this way are termed veto T cells. The experiments...... for the transfer of suppression of a secondary CTL response to B10 minors was of the host Thy-1 allotype, and so originated in the host spleen and was not introduced in the priming inoculum. Secondly, antigen-specific Ts generated in CBA female mice against B10 minors could act on CTL responses to an unequivocally...

  14. Heterozygous mutations in the tumor suppressor gene PATCHED provoke basal cell carcinoma-like features in human organotypic skin cultures.

    Science.gov (United States)

    Brellier, F; Bergoglio, V; Valin, A; Barnay, S; Chevallier-Lagente, O; Vielh, P; Spatz, A; Gorry, P; Avril, M-F; Magnaldo, T

    2008-11-20

    Basal cell carcinoma of the skin is the most common type of cancer in humans. The majority of these tumors displays aberrant activation of the SONIC HEDGEHOG (SHH)/PATCHED pathway, triggered by mutations in the PATCHED tumor suppressor gene, which encodes a transmembrane receptor of SHH. In this study, we took advantage of the natural genotype (PATCHED(+/-)) of healthy keratinocytes expanded from patients with the nevoid basal cell carcinoma or Gorlin syndrome to mimic heterozygous somatic mutations thought to occur in the PATCHED gene early upon basal cell carcinoma development in the general population. PATCHED(+/-) epidermis developed on a dermal equivalent containing wild-type (WT) PATCHED(+/+) fibroblasts exhibited striking invasiveness and hyperproliferation, as well as marked differentiation impairment. Deciphering the phenotype of PATCHED(+/-) keratinocytes revealed slight increases of the transcriptional activators GLI1 and GLI2-the latter known to provoke basal cell carcinoma-like tumors when overexpressed in transgenic mice. PATCHED(+/-) keratinocytes also showed a substantial increase of the cell cycle regulator cyclin D1. These data show for the first time the physiological impact of constitutive heterozygous PATCHED mutations in primary human keratinocytes and strongly argue for a yet elusive mechanism of haploinsufficiency leading to cancer proneness.

  15. GGNBP2 acts as a tumor suppressor by inhibiting estrogen receptor α activity in breast cancer cells.

    Science.gov (United States)

    Lan, Zi-Jian; Hu, YunHui; Zhang, Sheng; Li, Xian; Zhou, Huaxin; Ding, Jixiang; Klinge, Carolyn M; Radde, Brandie N; Cooney, Austin J; Zhang, Jin; Lei, Zhenmin

    2016-07-01

    Gametogenetin-binding protein 2 (GGNBP2) is encoded in human chromosome 17q12-q23, a region known as a breast and ovarian cancer susceptibility locus. GGNBP2, also referred to ZFP403, has a single C2H2 zinc finger and a consensus LxxLL nuclear receptor-binding motif. Here, we demonstrate that GGNBP2 expression is reduced in primary human breast tumors and in breast cancer cell lines, including T47D, MCF-7, LCC9, LY2, and MDA-MB-231 compared with normal, immortalized estrogen receptor α (ERα) negative MCF-10A and MCF10F breast epithelial cells. Overexpression of GGNBP2 inhibits the proliferation of T47D and MCF-7 ERα positive breast cancer cells without affecting MCF-10A and MCF10F. Stable GGNBP2 overexpression in T47D cells inhibits 17β-estradiol (E2)-stimulated proliferation as well as migration, invasion, anchorage-independent growth in vitro, and xenograft tumor growth in mice. We further demonstrate that GGNBP2 protein physically interacts with ERα, inhibits E2-induced activation of estrogen response element-driven reporter activity, and attenuates ER target gene expression in T47D cells. In summary, our in vitro and in vivo findings suggest that GGNBP2 is a novel breast cancer tumor suppressor functioning as a nuclear receptor corepressor to inhibit ERα activity and tumorigenesis.

  16. MicroRNA-140 mediates RB tumor suppressor function to control stem cell-like activity through interleukin-6.

    Science.gov (United States)

    Yoshida, Akiyo; Kitajima, Shunsuke; Li, Fengkai; Cheng, Chaoyang; Takegami, Yujiro; Kohno, Susumu; Wan, Yuan Song; Hayashi, Naoyuki; Muranaka, Hayato; Nishimoto, Yuuki; Nagatani, Naoko; Nishiuchi, Takumi; Thai, Tran C; Suzuki, Sawako; Nakao, Shinji; Tanaka, Tomoaki; Hirose, Osamu; Barbie, David A; Takahashi, Chiaki

    2017-02-21

    We established an in vitro cell culture system to determine novel activities of the retinoblastoma (Rb) protein during tumor progression. Rb depletion in p53-null mouse-derived soft tissue sarcoma cells induced a spherogenic phenotype. Cells retrieved from Rb-depleted spheres exhibited slower proliferation and less efficient BrdU incorporation, however, much higher spherogenic activity and aggressive behavior. We discovered six miRNAs, including mmu-miR-18a, -25, -29b, -140, -337, and -1839, whose expression levels correlated tightly with the Rb status and spherogenic activity. Among these, mmu-miR-140 appeared to be positively controlled by Rb and to antagonize the effect of Rb depletion on spherogenesis and tumorigenesis. Furthermore, among genes potentially targeted by mmu-miR-140, Il-6 was upregulated by Rb depletion and downregulated by mmu-mir-140 overexpression. Altogether, we demonstrate the possibility that mmu-mir-140 mediates the Rb function to downregulate Il-6 by targeting its 3'-untranslated region. Finally, we detected the same relationship among RB, hsa-miR-140 and IL-6 in a human breast cancer cell line MCF-7. Because IL-6 is a critical modulator of malignant features of cancer cells and the RB pathway is impaired in the majority of cancers, hsa-miR-140 might be a promising therapeutic tool that disrupts linkage between tumor suppressor inactivation and pro-inflammatory cytokine response.

  17. Expression of metastasis suppressor BRMS1 in breast cancer cells results in a marked delay in cellular adhesion to matrix.

    Science.gov (United States)

    Khotskaya, Yekaterina B; Beck, Benjamin H; Hurst, Douglas R; Han, Zhenbo; Xia, Weiya; Hung, Mien-Chie; Welch, Danny R

    2014-12-01

    Metastatic dissemination is a multi-step process that depends on cancer cells' ability to respond to microenvironmental cues by adapting adhesion abilities and undergoing cytoskeletal rearrangement. Breast Cancer Metastasis Suppressor 1 (BRMS1) affects several steps of the metastatic cascade: it decreases survival in circulation, increases susceptibility to anoikis, and reduces capacity to colonize secondary organs. In this report, BRMS1 expression is shown to not significantly alter expression levels of integrin monomers, while time-lapse and confocal microscopy revealed that BRMS1-expressing cells exhibited reduced activation of both β1 integrin and focal adhesion kinase, and decreased localization of these molecules to sites of focal adhesions. Short-term plating of BRMS1-expressing cells onto collagen or fibronectin markedly decreased cytoskeletal reorganization and formation of cellular adhesion projections. Under 3D culture conditions, BRMS1-expressing cells remained rounded and failed to reorganize their cytoskeleton and form invasive colonies. Taken together, BRMS1-expressing breast cancer cells are greatly attenuated in their ability to respond to microenvironment changes. © 2013 Wiley Periodicals, Inc. © 2013 Wiley Periodicals, Inc.

  18. Lethal giant larvae 1 tumour suppressor activity is not conserved in models of mammalian T and B cell leukaemia.

    Directory of Open Access Journals (Sweden)

    Edwin D Hawkins

    Full Text Available In epithelial and stem cells, lethal giant larvae (Lgl is a potent tumour suppressor, a regulator of Notch signalling, and a mediator of cell fate via asymmetric cell division. Recent evidence suggests that the function of Lgl is conserved in mammalian haematopoietic stem cells and implies a contribution to haematological malignancies. To date, direct measurement of the effect of Lgl expression on malignancies of the haematopoietic lineage has not been tested. In Lgl1⁻/⁻ mice, we analysed the development of haematopoietic malignancies either alone, or in the presence of common oncogenic lesions. We show that in the absence of Lgl1, production of mature white blood cell lineages and long-term survival of mice are not affected. Additionally, loss of Lgl1 does not alter leukaemia driven by constitutive Notch, c-Myc or Jak2 signalling. These results suggest that the role of Lgl1 in the haematopoietic lineage might be restricted to specific co-operating mutations and a limited number of cellular contexts.

  19. Immunomodulatory effect of prednisolone (PRD) induced soluble suppressor factor(s) (PRD-SSF) on natural killer (NK) cell activity

    Energy Technology Data Exchange (ETDEWEB)

    Nair, M.P.N.; Cilik, J.M.; Schwartz, S.A.

    1986-03-01

    The authors have previously reported that peripheral blood lymphocytes precultured for 24 hrs with PRD showed significant suppression of their NK activity. Purified HNK-1/sup +/ lymphocytes were treated either directly with PRD or with supernates from allogeneic lymphocytes precultured with 10/sup -6/ to 10/sup -9/M PRD and examined for any inhibition of NK activity. For the NK assay K562 and U937 cell lines were used as targets in a 4 hr /sup 51/Cr release assay. HNK-1/sup +/ lymphocytes precultured with PRD showed significantly lower level of NK activity. In a single cell assay, both HNK-1/sup +/ and HNK-1/sup -/ subpopulations of PBL precultured with PRD also suppressed the target binding and lytic capacity of allogeneic fresh large granular lymphocytes, suggesting that NK cells/T cells or their precursors can be stimulated by PRD to inhibit NK activity. PBL precultured with increasing concentrations of culture supernates containing PRD-SSF showed a dose dependent inhibitory effect of their NK activity. This data suggest that PRD activated suppressor cells function through the release of soluble mediators. These findings may be of clinical significance to patients receiving corticosteroids for a variety of disorders including malignant, autoimmune and atopic diseases.

  20. Multi-gene epigenetic silencing of tumor suppressor genes in T-cell lymphoma cells; delayed expression of the p16 protein upon reversal of the silencing

    DEFF Research Database (Denmark)

    Nagasawa, T; Zhang, Q; Raghunath, P N

    2006-01-01

    )-expressing T-cell lymphomas. p16 gene was epigenetically silenced in all but one of the 10 malignant T-cell lines examined, p15 gene silenced in roughly half of the lines, and p14 was the least frequently affected. Extensive methylation of the p16 promoter was seen in six out of 10 cutaneous T-cell lymphoma...... promoter demethylation and required up to 3 weeks to occur, seemingly reflecting late activation of the p16 gene. These findings indicate that epigenetic silencing affects in T-cell malignancies, often simultaneously, several tumor suppressor genes that impact on key cell functions. The observed...... differential silencing of p16 and p14, and to a lesser degree p15 gene, indicates that the silencing is governed by precise, promoter region-specific mechanisms. The study provides also further rationale for treatment of at least some types of T-cell lymphomas with DNA methyltransferase inhibitors to target...

  1. Chemotherapy alters the increased numbers of myeloid-derived suppressor and regulatory T cells in children with acute lymphoblastic leukemia.

    Science.gov (United States)

    Salem, Mohamed Labib; El-Shanshory, Mohamed R; Abdou, Said H; Attia, Mohamed S; Sobhy, Shymaa M; Zidan, Mona F; Zidan, Abdel-Aziz A

    2018-04-01

    Acute lymphoblastic leukemia (ALL) is the most common cancer diagnosed in children. The precise mechanism behind the relapse in this disease is not clearly known. One possible mechanism could be the accumulation of immunosuppressive cells, including myeloid-derived suppressor cells (MDSCs) and T regulatory cells (T regs ) which we and others have reported to mediate suppression of anti-tumor immune responses. In this study, we aimed to analyze the numbers of these cells in a population of B-ALL pediatric patients. Peripheral blood samples withdrawn from B-ALL pediatric patients (n = 45 before, during and after the induction phase of chemotherapy. Using multi parametric flow cytometric analysis. MDSCs were identified as Lin - HLA-DR - CD33 + CD11b + ; and T reg cells were defined as CD4 + CD25 + CD127 -/low . Early diagnosed B-ALL patients showed significant increases in the numbers of MDSCs and T regs as compared to healthy volunteers. During induction of chemotherapy, however, the patients showed higher and lower numbers of MDSCs and T reg cells, respectively as compared to early diagnosed patients (i.e., before chemotherapy). After induction of chemotherapy, the numbers of MDSCs and T reg cells showed higher increases and decreases, respectively as compared to the numbers in patients during chemotherapy. Our results indicate that B-ALL patients harbor high numbers of both MDSCs and T regs cells. This pilot study opens a new avenue to investigate the mechanism mediating the emergence of these cells on larger number of B-ALL patients at different treatment stages.

  2. MicroRNAs as tumour suppressors in canine and human melanoma cells and as a prognostic factor in canine melanomas.

    Science.gov (United States)

    Noguchi, S; Mori, T; Hoshino, Y; Yamada, N; Maruo, K; Akao, Y

    2013-06-01

    Malignant melanoma (MM) is one of the most aggressive cancers in dogs and in humans. However, the molecular mechanisms of its development and progression remain unclear. Presently, we examined the expression profile of microRNAs (miRs) in canine oral MM tissues and paired normal oral mucosa tissues by using the microRNA-microarray assay and quantitative RT-PCR. Importantly, a decreased expression of miR-203 was significantly associated with a shorter survival time. Also, miR-203 and -205 were markedly down-regulated in canine and human MM cell lines tested. Furthermore, the ectopic expression of miR-205 had a significant inhibitory effect on the cell growth of canine and human melanoma cells tested by targeting erbb3. Our data suggest that miR-203 is a new prognostic factor in canine oral MMs and that miR-205 functions as a tumour suppressor by targeting erbb3 in both canine and human MM cells. © 2011 John Wiley & Sons Ltd.

  3. C-Myc negatively controls the tumor suppressor PTEN by upregulating miR-26a in glioblastoma multiforme cells

    International Nuclear Information System (INIS)

    Guo, Pin; Nie, Quanmin; Lan, Jin; Ge, Jianwei; Qiu, Yongming; Mao, Qing

    2013-01-01

    Highlights: •The c-Myc oncogene directly upregulates miR-26a expression in GBM cells. •ChIP assays demonstrate that c-Myc interacts with the miR-26a promoter. •Luciferase reporter assays show that PTEN is a specific target of miR-26a. •C-Myc–miR-26a suppression of PTEN may regulate the PTEN/AKT pathway. •Overexpression of c-Myc enhances the proliferative capacity of GBM cells. -- Abstract: The c-Myc oncogene is amplified in many tumor types. It is an important regulator of cell proliferation and has been linked to altered miRNA expression, suggesting that c-Myc-regulated miRNAs might contribute to tumor progression. Although miR-26a has been reported to be upregulated in glioblastoma multiforme (GBM), the mechanism has not been established. We have shown that ectopic expression of miR-26a influenced cell proliferation by targeting PTEN, a tumor suppressor gene that is inactivated in many common malignancies, including GBM. Our findings suggest that c-Myc modulates genes associated with oncogenesis in GBM through deregulation of miRNAs via the c-Myc–miR-26a–PTEN signaling pathway. This may be of clinical relevance

  4. C-Myc negatively controls the tumor suppressor PTEN by upregulating miR-26a in glioblastoma multiforme cells

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Pin; Nie, Quanmin; Lan, Jin; Ge, Jianwei [Department of Neurosurgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127 (China); Qiu, Yongming, E-mail: qiuzhoub@hotmail.com [Department of Neurosurgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127 (China); Shanghai Institute of Head Trauma, Shanghai 200127 (China); Mao, Qing, E-mail: maoq@netease.com [Department of Neurosurgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127 (China); Shanghai Institute of Head Trauma, Shanghai 200127 (China)

    2013-11-08

    Highlights: •The c-Myc oncogene directly upregulates miR-26a expression in GBM cells. •ChIP assays demonstrate that c-Myc interacts with the miR-26a promoter. •Luciferase reporter assays show that PTEN is a specific target of miR-26a. •C-Myc–miR-26a suppression of PTEN may regulate the PTEN/AKT pathway. •Overexpression of c-Myc enhances the proliferative capacity of GBM cells. -- Abstract: The c-Myc oncogene is amplified in many tumor types. It is an important regulator of cell proliferation and has been linked to altered miRNA expression, suggesting that c-Myc-regulated miRNAs might contribute to tumor progression. Although miR-26a has been reported to be upregulated in glioblastoma multiforme (GBM), the mechanism has not been established. We have shown that ectopic expression of miR-26a influenced cell proliferation by targeting PTEN, a tumor suppressor gene that is inactivated in many common malignancies, including GBM. Our findings suggest that c-Myc modulates genes associated with oncogenesis in GBM through deregulation of miRNAs via the c-Myc–miR-26a–PTEN signaling pathway. This may be of clinical relevance.

  5. Mechanisms of cross-suppression of TNP-specific plaque forming cell responses by TMA-specific first-order T suppressor factor

    Energy Technology Data Exchange (ETDEWEB)

    Jendrisak, G.S.; Bellone, C.J.

    1986-03-05

    The addition of hybridoma-derived phenyltrimethylammonium (TMA)-specific first-order T suppressor factor (TsF/sub 1/) into cultures containing Brucella abortus coupled with the TMA and trinitrophenol haptens (TMA-BA-TNP) results in the cross-suppression of TNP-specific plaque forming cell (PFC) responses. The suppression mediated by TMA-TsF/sub 1/ is dependent on the presence of T cells and specific antigen (TMA). Subculturing of whole spleen cells with TMA-TsF/sub 1/ and specific soluble antigen (TMA-BSA) is able to induce suppressor T cells which cross-suppress the TNP-specific PFC of spleen cell cultures stimulated with TMA-BA-TNP in an antigen (TMA)-dependent manner at the effector phase of the response. The effector acting T suppressor cells (Tse) are nylon wool nonadherent and appears to require whole spleen cells in responding cultures for suppression, suggesting that the target of the Tse is not the TNP-specific B cell. The authors are presently characterizing the mechanisms of cross-suppression by TMA-TsF/sub 1/ and Tse utilizing the described primary in vitro antibody assay.

  6. The tumor suppressor PTEN inhibits EGF-induced TSP-1 and TIMP-1 expression in FTC-133 thyroid carcinoma cells

    International Nuclear Information System (INIS)

    Soula-Rothhut, Mahdhia; Coissard, Cyrille; Sartelet, Herve; Boudot, Cedric; Bellon, Georges; Martiny, Laurent; Rothhut, Bernard

    2005-01-01

    Thrombospondin-1 (TSP-1) is a multidomain extracellular macromolecule that was first identified as natural modulator of angiogenesis and tumor growth. In the present study, we found that epidermal growth factor (EGF) up-regulated TSP-1 expression in FTC-133 (primary tumor) but not in FTC-238 (lung metastasis) thyroid cancer cells. Both EGF and TSP-1 induced expression of tissue inhibitor of metalloproteinase-1 (TIMP-1) in a mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) and phosphatidylinositol 3-kinase (PI3-kinase)-dependent manner. In FTC-133 cells, EGF induced proliferation in a TSP-1- and TIMP-1-dependent manner. In addition, we determined that re-expression of the tumor suppressor protein PTEN induced cell death, an effect that correlated with a block of Akt kinase phosphorylation. EGF-induced TSP-1 and TIMP-1 promoter activity and protein expression were inhibited in FTC-133 cells stably expressing wtPTEN but not in cells expressing mutant PTEN. Furthermore, we found that wtPTEN inhibited EGF-but not TSP-1-stimulated FTC-133 cell migration and also inhibited invasion induced by EGF and by TSP-1. Finally, an antibody against TSP-1 reversed EGF-stimulated FTC-133 cell invasion as well as the constitutive invasive potential of FTC-238 cells. Overall, our results suggest that PTEN can function as an important modulator of extracellular matrix proteins in thyroid cancer. Therefore, analyzing differential regulation of TSP-1 by growth factors such as EGF can be helpful in understanding thyroid cancer development

  7. Cdh11 Acts as a Tumor Suppressor in a Murine Retinoblastoma Model by Facilitating Tumor Cell Death

    Science.gov (United States)

    Marchong, Mellone N.; Yurkowski, Christine; Ma, Clement; Spencer, Clarellen; Pajovic, Sanja; Gallie, Brenda L.

    2010-01-01

    CDH11 gene copy number and expression are frequently lost in human retinoblastomas and in retinoblastomas arising in TAg-RB mice. To determine the effect of Cdh11 loss in tumorigenesis, we crossed Cdh11 null mice with TAg-RB mice. Loss of Cdh11 had no gross morphological effect on the developing retina of Cdh11 knockout mice, but led to larger retinal volumes in mice crossed with TAg-RB mice (p = 0.01). Mice null for Cdh11 presented with fewer TAg-positive cells at postnatal day 8 (PND8) (p = 0.01) and had fewer multifocal tumors at PND28 (p = 0.016), compared to mice with normal Cdh11 alleles. However, tumor growth was faster in Cdh11-null mice between PND8 and PND84 (p = 0.003). In tumors of Cdh11-null mice, cell death was decreased 5- to 10-fold (p<0.03 for all markers), while proliferation in vivo remained unaffected (p = 0.121). Activated caspase-3 was significantly decreased and β-catenin expression increased in Cdh11 knockdown experiments in vitro. These data suggest that Cdh11 displays tumor suppressor properties in vivo and in vitro in murine retinoblastoma through promotion of cell death. PMID:20421947

  8. Cdh11 acts as a tumor suppressor in a murine retinoblastoma model by facilitating tumor cell death.

    Directory of Open Access Journals (Sweden)

    Mellone N Marchong

    2010-04-01

    Full Text Available CDH11 gene copy number and expression are frequently lost in human retinoblastomas and in retinoblastomas arising in TAg-RB mice. To determine the effect of Cdh11 loss in tumorigenesis, we crossed Cdh11 null mice with TAg-RB mice. Loss of Cdh11 had no gross morphological effect on the developing retina of Cdh11 knockout mice, but led to larger retinal volumes in mice crossed with TAg-RB mice (p = 0.01. Mice null for Cdh11 presented with fewer TAg-positive cells at postnatal day 8 (PND8 (p = 0.01 and had fewer multifocal tumors at PND28 (p = 0.016, compared to mice with normal Cdh11 alleles. However, tumor growth was faster in Cdh11-null mice between PND8 and PND84 (p = 0.003. In tumors of Cdh11-null mice, cell death was decreased 5- to 10-fold (p<0.03 for all markers, while proliferation in vivo remained unaffected (p = 0.121. Activated caspase-3 was significantly decreased and beta-catenin expression increased in Cdh11 knockdown experiments in vitro. These data suggest that Cdh11 displays tumor suppressor properties in vivo and in vitro in murine retinoblastoma through promotion of cell death.

  9. [Compound K suppresses myeloid-derived suppressor cells in a mouse model bearing CT26 colorectal cancer xenograft].

    Science.gov (United States)

    Wang, Rong; Li, Yalin; Wang, Wuzhou; Zhou, Meijuan; Cao, Zhaohui

    2015-05-01

    To investigate the effect of ginseng-derived compound K (C-K) on apoptosis, immunosuppressive activity, and pro-inflammatory cytokine production of myeloid-derived suppressor cells (MDSCs) from mice bearing colorectal cancer xenograft. Flow-sorted bone marrow MDSCs from Balb/c mice bearing CT26 tumor xenograft were treated with either C-K or PBS for 96 h and examined for apoptosis with Annexin V/7-AAD, Cox-2 and Arg-1 expressions using qRT-PCR, and supernatant IL-1β, IL-6, and IL-17 levels with ELISA. C-K- or PBS-treated MDSCs were subcutaneously implanted along with CT26 tumor cells in WT Balb/c mice, and the tumor size and morphology were evaluated 21 days later. C-K treatment significantly increased the percentages of early and late apoptotic MDSCs in vitro (Pimmunosuppresive effect of MDSCs to inhibit tumor cell proliferation in mice, which suggests a new strategy of tumor therapy by targeting MDSCs.

  10. The Fbw7 tumor suppressor targets KLF5 for ubiquitin-mediated degradation and suppresses breast cell proliferation.

    Science.gov (United States)

    Zhao, Dong; Zheng, Han-Qiu; Zhou, Zhongmei; Chen, Ceshi

    2010-06-01

    Fbw7 is a tumor suppressor frequently inactivated in cancers. The KLF5 transcription factor promotes breast cell proliferation and tumorigenesis through upregulating FGF-BP. The KLF5 protein degrades rapidly through the ubiquitin proteasome pathway. Here, we show that the Skp1-CUL1-Fbw7 E3 ubiquitin ligase complex (SCF(Fbw7)) targets KLF5 for ubiquitin-mediated degradation in a GSK3beta-mediated KLF5 phosphorylation-dependent manner. Mutation of the critical S303 residue in the KLF5 Cdc4 phospho-degrons motif ((303)SPPSS) abolishes the protein interaction, ubiquitination, and degradation by Fbw7. Inactivation of endogenous Fbw7 remarkably increases the endogenous KLF5 protein abundances. Endogenous Fbw7 suppresses the FGF-BP gene expression and breast cell proliferation through targeting KLF5 for degradation. These findings suggest that Fbw7 inhibits breast cell proliferation at least partially through targeting KLF5 for proteolysis. This new regulatory mechanism of KLF5 degradation may result in useful diagnostic and therapeutic targets for breast cancer and other cancers. Copyright 2010 AACR.

  11. MicroRNA-30e Functions as a Tumor Suppressor in Cervical Carcinoma Cells through Targeting GALNT7

    Directory of Open Access Journals (Sweden)

    Huijuan Wu

    2017-12-01

    Full Text Available Cervical cancer is the third most common cancer in women worldwide. However, the underlying mechanism of occurrence and development of cervical cancer is obscure. In this study, we observed that miR-30e was downregulated in clinical cervical cancer tissues and cervical cancer cells. Next, overexpression of miR-30e reduced the cervical cancer cell growth through MTT, colony formation, EdU, and Transwell assay in SiHa and Caski cells. Subsequently, UDP-N-acetyl-D-galactosamine: polypeptide N-acetylgalactosaminyltransferase 7 (GALNT7 was identified as a potential miR-30e target by bioinformatics analysis. Moreover, we showed that miR-30e was able to bind to the 3′UTR of GALNT7 by luciferase reporter assay. In addition, the mRNA and protein levels of GALNT7 in cervical cancer cells were downregulated by miR-30e. And we validated that downregulation of GALNT7 repressed the proliferation of SiHa and Caski cells by MTT, colony formation, and Transwell assay. We identified that the restoration of GALNT7 expression was able to counteract the effect of miR-30e on cell proliferation of cervical cancer cells. Furthermore, we found that the expression levels of GALNT7 were frequently upregulated and negatively correlative to those of miR-30e in cervical cancer tissues. In addition, we validated that restoration of GALNT7 rescued the miR-30e–suppressed growth of cervical cancer xenografts in vivo. In conclusion, the current results suggest that miR-30e may function as tumor suppressors in cervical cancer through downregulation of GALNT7. Both miR-30e and its novel target, GALNT7, may play an important role in the process of cervical cancer.

  12. LncRNA TUG1 acts as a tumor suppressor in human glioma by promoting cell apoptosis.

    Science.gov (United States)

    Li, Jun; Zhang, Meng; An, Gang; Ma, Qingfang

    2016-03-01

    Previous studies have revealed multiple functional roles of long non-coding RNA taurine upregulated gene 1 in different types of malignant tumors, except for human glioma. Here, it was designed to study the potential function of taurine upregulated gene 1 in glioma pathogenesis focusing on its regulation on cell apoptosis. The expression of taurine upregulated gene 1 in glioma tissues was detected by quantitative RT-PCR and compared with that in adjacent normal tissues. Further correlation analysis was conducted to show the relationship between taurine upregulated gene 1 expression and different clinicopathologic parameters. Functional studies were performed to investigate the influence of taurine upregulated gene 1 on apoptosis and cell proliferation by using Annexin V/PI staining and cell counting kit-8 assays, respectively. And, caspase activation and Bcl-2 expression were analyzed to explore taurine upregulated gene 1-induced mechanism. taurine upregulated gene 1 expression was significantly inhibited in glioma and showed significant correlation with WHO Grade, tumor size and overall survival. Further experiments revealed that the dysregulation of taurine upregulated gene 1 affected the apoptosis and cell proliferation of glioma cells. Moreover, taurine upregulated gene 1 could induce the activation of caspase-3 and-9, with inhibited expression of Bcl-2, implying the mechanism in taurine upregulated gene 1-induced apoptosis. taurine upregulated gene 1 promoted cell apoptosis of glioma cells by activating caspase-3 and -9-mediated intrinsic pathways and inhibiting Bcl-2-mediated anti-apoptotic pathways, acting as a tumor suppressor in human glioma. This study provided new insights for the function of taurine upregulated gene 1 in cancer biology, and suggested a potent application of taurine upregulated gene 1 overexpression for glioma therapy. © 2016 by the Society for Experimental Biology and Medicine.

  13. Human xenospecific T suppressor cells inhibit T helper cell proliferation to porcine aortic endothelial cells, and NF-kappaB activity in porcine APC.

    Science.gov (United States)

    Ciubotariu, R; Li, J; Colovai, A I; Platt, J L; Cortesini, R; Suciu Foca Cortesini, N

    2001-05-01

    Human T suppressor cells (Ts), capable of preventing autologous T helper cells (Th) from reacting against xenogeneic pig endothelial cells and pig APC can be generated in vitro. Ts derive from a population of CD3(+)CD8(+)CD28(-) T lymphocytes and specifically recognize the MHC class I antigens of the APC used for in vitro immunization. To study the mechanism that underlies suppression, we investigated whether Ts inhibit the expression of costimulatory molecules in xenogeneic professional and semiprofessional APC. We found that Ts down-regulate Th-induced expression of CD86 in pig APC, and that this effect occurs at the level of transcription, as indicated by nuclear run-on and Northern blot assays. EMSA results revealed that inhibition of CD86 expression is mediated by inactivation of transcription factor NF-kappaB. Furthermore, transfection of pig APC with a vector expressing NF-kappaB p65 partially rescued Th-induced expression of the CD86 molecule. These results strongly support the concept that xenospecific Ts inhibit the APC function of xenogeneic cells by preventing activation of NF-kappaB.

  14. [Silencing of tumor metastasis suppressor gene 1 promotes invasion of prostate cancer cell in vitro and its molecular mechanisms].

    Science.gov (United States)

    Xu, Xiao-yan; You, Jiang-feng; Pei, Fei; Zhang, Bo

    2011-12-18

    To explore the effect of small interference RNA (siRNA) targeting homosapiens longevity assurance homologue 2(LASS2, or TMSG1) on the invasion of PC-3M-2B4 (a variant subline of human prostate carcinoma cell line PC-3M with low metastatic potential) and its molecular mechanisms. PC-3M-2B4 cells were transfected with siRNA by using lipofectamine 2000. The expression of LASS2 mRNA and protein was detected after transfection by real-time fluorogentic quantitative PCR (RFQ-PCR) and Western blot to screen the effective siRNA fragment. The V-ATPase activity of PC-3M-2B4 cells was detected by V-ATPase activity assay kit. The concentration of extracellular hydrogen ion was measured by pH-sensitive fluorescence probe bis-carboxyethyl-carboxyfluorescein (BCECF). The matrix metalloproteinase-2 (MMP-2) protein in the supernatant and cells was analyzed by Western blot. The activity of MMP-2 was examined by Gelatin zymography. Furthermore, the migration and invasion of cells were evaluated by in vitro wound migration assay and invasion assay. RFQ-PCR and Western blot revealed dramatic reduction (84.5% and 60% ) in the levels of LASS2 mRNA and protein after transfection of siRNA-2 in PC-3M-2B4 cells. The V-ATPases activity and extracellular hydrogen ion concentration were significantly increased in PC-3M-2B4 cells transfected with the siRNA-2 compared with other control groups (P<0.05); There were no differences in the expression and secretion of MMP-2 protein between LASS2-siRNA treated cells and other control groups. However, the activity of MMP-2 was up-regulated in LASS2-siRNA treated cells compared with other control groups( P<0.05); and the capacity for migration and invasion in LASS2-siRNA treated cells was significantly higher than in other control groups (P<0.05). Silencing of LASS2 can promote invasion of prostate cancer cells in vitro through the increase of the V-ATPases activity, extracellular hydrogen ion concentration and in turn the activation of secreted MMP-2

  15. Relevance of miR-21 in regulation of tumor suppressor gene PTEN in human cervical cancer cells

    International Nuclear Information System (INIS)

    Peralta-Zaragoza, Oscar; Deas, Jessica; Meneses-Acosta, Angélica; De la O-Gómez, Faustino; Fernández-Tilapa, Gloria; Gómez-Cerón, Claudia; Benítez-Boijseauneau, Odelia; Burguete-García, Ana; Torres-Poveda, Kirvis; Bermúdez-Morales, Victor Hugo; Madrid-Marina, Vicente; Rodríguez-Dorantes, Mauricio; Hidalgo-Miranda, Alfredo; Pérez-Plasencia, Carlos

    2016-01-01

    Expression of the microRNA miR-21 has been found to be altered in almost all types of cancers and it has been classified as an oncogenic microRNA or oncomir. Due to the critical functions of its target proteins in various signaling pathways, miR-21 is an attractive target for genetic and pharmacological modulation in various cancers. Cervical cancer is the second most common cause of death from cancer in women worldwide and persistent HPV infection is the main etiologic agent. This malignancy merits special attention for the development of new treatment strategies. In the present study we analyze the role of miR-21 in cervical cancer cells. To identify the downstream cellular target genes of upstream miR-21, we silenced endogenous miR-21 expression in a cervical intraepithelial neoplasia-derived cell lines using siRNAs. The effect of miR-21 on gene expression was assessed in cervical cancer cells transfected with the siRNA expression plasmid pSIMIR21. We identified the tumor suppressor gene PTEN as a target of miR-21 and determined the mechanism of its regulation throughout reporter construct plasmids. Using this model, we analyzed the expression of miR-21 and PTEN as well as functional effects such as autophagy and apoptosis induction. In SiHa cells, there was an inverse correlation between miR-21 expression and PTEN mRNA level as well as PTEN protein expression in cervical cancer cells. Transfection with the pSIMIR21 plasmid increased luciferase reporter activity in construct plasmids containing the PTEN-3′-UTR microRNA response elements MRE21-1 and MRE21-2. The role of miR-21 in cell proliferation was also analyzed in SiHa and HeLa cells transfected with the pSIMIR21 plasmid, and tumor cells exhibited markedly reduced cell proliferation along with autophagy and apoptosis induction. We conclude that miR-21 post-transcriptionally down-regulates the expression of PTEN to promote cell proliferation and cervical cancer cell survival. Therefore, it may be a

  16. Loss of the HVEM Tumor Suppressor in Lymphoma and Restoration by Modified CAR-T Cells.

    Science.gov (United States)

    Boice, Michael; Salloum, Darin; Mourcin, Frederic; Sanghvi, Viraj; Amin, Rada; Oricchio, Elisa; Jiang, Man; Mottok, Anja; Denis-Lagache, Nicolas; Ciriello, Giovanni; Tam, Wayne; Teruya-Feldstein, Julie; de Stanchina, Elisa; Chan, Wing C; Malek, Sami N; Ennishi, Daisuke; Brentjens, Renier J; Gascoyne, Randy D; Cogné, Michel; Tarte, Karin; Wendel, Hans-Guido

    2016-10-06

    The HVEM (TNFRSF14) receptor gene is among the most frequently mutated genes in germinal center lymphomas. We report that loss of HVEM leads to cell-autonomous activation of B cell proliferation and drives the development of GC lymphomas in vivo. HVEM-deficient lymphoma B cells also induce a tumor-supportive microenvironment marked by exacerbated lymphoid stroma activation and increased recruitment of T follicular helper (T FH ) cells. These changes result from the disruption of inhibitory cell-cell interactions between the HVEM and BTLA (B and T lymphocyte attenuator) receptors. Accordingly, administration of the HVEM ectodomain protein (solHVEM (P37-V202) ) binds BTLA and restores tumor suppression. To deliver solHVEM to lymphomas in vivo, we engineered CD19-targeted chimeric antigen receptor (CAR) T cells that produce solHVEM locally and continuously. These modified CAR-T cells show enhanced therapeutic activity against xenografted lymphomas. Hence, the HVEM-BTLA axis opposes lymphoma development, and our study illustrates the use of CAR-T cells as "micro-pharmacies" able to deliver an anti-cancer protein. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Chronic but not acute virus infection induces sustained expansion of myeloid suppressor cell numbers that inhibit viral-specific T cell immunity.

    Science.gov (United States)

    Norris, Brian A; Uebelhoer, Luke S; Nakaya, Helder I; Price, Aryn A; Grakoui, Arash; Pulendran, Bali

    2013-02-21

    Resolution of acute and chronic viral infections requires activation of innate cells to initiate and maintain adaptive immune responses. Here we report that infection with acute Armstrong (ARM) or chronic Clone 13 (C13) strains of lymphocytic choriomeningitis virus (LCMV) led to two distinct phases of innate immune response. During the first 72 hr of infection, dendritic cells upregulated activation markers and stimulated antiviral CD8(+) T cells, independent of viral strain. Seven days after infection, there was an increase in Ly6C(hi) monocytic and Gr-1(hi) neutrophilic cells in lymphoid organs and blood. This expansion in cell numbers was enhanced and sustained in C13 infection, whereas it occurred only transiently with ARM infection. These cells resembled myeloid-derived suppressor cells and potently suppressed T cell proliferation. The reduction of monocytic cells in Ccr2(-/-) mice or after Gr-1 antibody depletion enhanced antiviral T cell function. Thus, innate cells have an important immunomodulatory role throughout chronic infection. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. NKL homeobox gene MSX1 acts like a tumor suppressor in NK-cell leukemia.

    Science.gov (United States)

    Nagel, Stefan; Pommerenke, Claudia; Meyer, Corinna; Kaufmann, Maren; MacLeod, Roderick A F; Drexler, Hans G

    2017-09-15

    NKL homeobox gene MSX1 is physiologically expressed in lymphoid progenitors and subsequently downregulated in developing T- and B-cells. In contrast, elevated expression levels of MSX1 persist in mature natural killer (NK)-cells, indicating a functional role in this compartment. While T-cell acute lymphoblastic leukemia (T-ALL) subsets exhibit aberrant overexpression of MSX1, we show here that in malignant NK-cells the level of MSX1 transcripts is aberrantly downregulated. Chromosomal deletions at 4p16 hosting the MSX1 locus have been described in NK-cell leukemia patients. However, NK-cell lines analyzed here showed normal MSX1 gene configurations, indicating that this aberration might be uncommon. To identify alternative MSX1 regulatory mechanisms we compared expression profiling data of primary normal NK-cells and malignant NK-cell lines. This procedure revealed several deregulated genes including overexpressed IRF4, MIR155HG and MIR17HG and downregulated AUTS2, EP300, GATA3 and HHEX. As shown recently, chromatin-modulator AUTS2 is overexpressed in T-ALL subsets where it mediates aberrant transcriptional activation of MSX1. Here, our data demonstrate that in malignant NK-cell lines AUTS2 performed MSX1 activation as well, but in accordance with downregulated MSX1 transcription therein we detected reduced AUTS2 expression, a small genomic deletion at 7q11 removing exons 3 and 4, and truncating mutations in exon 1. Moreover, genomic profiling and chromosomal analyses of NK-cell lines demonstrated amplification of IRF4 at 6p25 and deletion of PRDM1 at 6q21, highlighting their potential oncogenic impact. Functional analyses performed via knockdown or forced expression of these genes revealed regulatory network disturbances effecting downregulation of MSX1 which may underlie malignant development in NK-cells.

  19. Reduction of myeloid suppressor cell derived nitric oxide provides a mechanistic basis of lead enhancement of alloreactive CD4+ T cell proliferation

    International Nuclear Information System (INIS)

    Farrer, David G.; Hueber, Sara; Laiosa, Michael D.; Eckles, Kevin G.; McCabe, Michael J.

    2008-01-01

    The persistent environmental toxicant and immunomodulator, lead (Pb), has been proposed to directly target CD4 + T cells. However, our studies suggest that CD4 + T cells are an important functional, yet indirect target. In order to identify the direct target of Pb in the immune system and the potential mechanism of Pb-induced immunotoxicity, myeloid suppressor cells (MSCs) were evaluated for their ability to modulate CD4 + T cell proliferation after Pb exposure. Myeloid suppressor cells regulate the adaptive immune response, in part, by inhibiting the proliferation of CD4 + T cells. It is thought that the mechanism of MSC-dependent regulation involves the release of the bioactive gas, nitric oxide (NO), blocking cell signaling cascades downstream of the IL-2 receptor and thus preventing T cells from entering cell-cycle. In mixed lymphocyte culture (MLC), increasing numbers of MSCs suppressed T cell proliferation in a dose-dependent manner, and this suppression is strikingly abrogated with 5 μM lead (Pb) treatment. The Pb-sensitive MSC population is CD11b + , GR1 + and CD11c - and thus phenotypically consistent with MSCs described in other literature. Inhibition of NO-synthase (NOS), the enzyme responsible for the production of NO, enhanced alloreactive T cell proliferation in MLC. Moreover, Pb attenuated NO production in MLC, and exogenous replacement of NO restored suppression in the presence of Pb. Significantly, MSC from iNOS-/- mice were unable to suppress T cell proliferation. An MSC-derived cell line (MSC-1) also suppressed T cell proliferation in MLC, and Pb disrupted this suppression by attenuating NO production. Additionally, Pb disrupted NO production in MSC-1 cells in response to treatment with interferon-γ (IFN-γ) and LPS or in response to concanavalin A-stimulated splenocytes. However, neither the abundance of protein nor levels of mRNA for the inducible isoform of NOS (iNOS) were altered with Pb treatment. Taken together these data suggest that Pb

  20. The effect of suppressor of cytokine signaling 3 on GH signaling in beta-cells

    DEFF Research Database (Denmark)

    Rønn, Sif G; Hansen, Johnny A; Lindberg, Karen

    2002-01-01

    GH is an important regulator of cell growth and metabolism. In the pancreas, GH stimulates mitogenesis as well as insulin production in beta-cells. The cellular effects of GH are exerted mainly through activation of the Janus kinase-signal transducer and activator of transcription (STAT) pathway...

  1. Moringa oleifera Gold Nanoparticles Modulate Oncogenes, Tumor Suppressor Genes, and Caspase-9 Splice Variants in A549 Cells.

    Science.gov (United States)

    Tiloke, Charlette; Phulukdaree, Alisa; Anand, Krishnan; Gengan, Robert M; Chuturgoon, Anil A

    2016-10-01

    Gold nanoparticles (AuNP's) facilitate cancer cell recognition and can be manufactured by green synthesis using nutrient rich medicinal plants such as Moringa oleifera (MO). Targeting dysregulated oncogenes and tumor suppressor genes is crucial for cancer therapeutics. We investigated the antiproliferative effects of AuNP synthesized from MO aqueous leaf extracts (MLAuNP ) in A549 lung and SNO oesophageal cancer cells. A one-pot green synthesis technique was used to synthesise MLAuNP . A549, SNO cancer cells and normal peripheral blood mononuclear cells (PBMCs) were exposed to MLAuNP and CAuNP to evaluate cytotoxicity (MTT assay); apoptosis was measured by phosphatidylserine (PS) externalization, mitochondrial depolarization (ΔΨm) (flow cytometry), caspase-3/7, -9 activity, and ATP levels (luminometry). The mRNA expression of c-myc, p53, Skp2, Fbw7α, and caspase-9 splice variants was determined using qPCR, while relative protein expression of c-myc, p53, SRp30a, Bax, Bcl-2, Smac/DIABLO, Hsp70, and PARP-1 were determined by Western blotting. MLAuNP and CAuNP were not cytotoxic to PBMCs, whilst its pro-apoptotic properties were confirmed in A549 and SNO cells. MLAuNP significantly increased caspase activity in SNO cells while MLAuNP significantly increased PS externalization, ΔΨm, caspase-9, caspase-3/7 activities, and decreased ATP levels in A549 cells. Also, p53 mRNA and protein levels, SRp30a (P = 0.428), Bax, Smac/DIABLO and PARP-1 24 kDa fragment levels were significantly increased. Conversely, MLAuNP significantly decreased Bcl-2, Hsp70, Skp2, Fbw7α, c-myc mRNA, and protein levels and activated alternate splicing with caspase-9a splice variant being significantly increased. MLAuNP possesses antiproliferative properties and induced apoptosis in A549 cells by activating alternate splicing of caspase-9. J. Cell. Biochem. 117: 2302-2314, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  2. TNF{alpha} induced FOXP3-NF{kappa}B interaction dampens the tumor suppressor role of FOXP3 in gastric cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Qiang; Li, Weina; Zhang, Cun; Qin, Xin; Xue, Xiaochang; Li, Meng; Shu, Zhen; Xu, Tianjiao; Xu, Yujin; Wang, Weihua [The State Key Laboratory of Cancer Biology, School of Pharmacy, Department of Biopharmaceutics, Fourth Military Medical University, Xi' an 710032 (China); Zhang, Wei, E-mail: Zhangw90@fmmu.edu.cn [The State Key Laboratory of Cancer Biology, School of Pharmacy, Department of Biopharmaceutics, Fourth Military Medical University, Xi' an 710032 (China); Zhang, Yingqi, E-mail: Zhangyqh@fmmu.edu.cn [The State Key Laboratory of Cancer Biology, School of Pharmacy, Department of Biopharmaceutics, Fourth Military Medical University, Xi' an 710032 (China)

    2013-01-04

    Highlights: Black-Right-Pointing-Pointer FOXP3 inhibition of cell proliferation is p21-dependent under basal conditions. Black-Right-Pointing-Pointer Inflammation induced by TNF{alpha} inhibits the tumor suppressor role of FOXP3. Black-Right-Pointing-Pointer Interaction between p65 and FOXP3 inhibits p21 transcription activation. -- Abstract: Controversial roles of FOXP3 in different cancers have been reported previously, while its role in gastric cancer is largely unknown. Here we found that FOXP3 is unexpectedly upregulated in some gastric cancer cells. To test whether increased FOXP3 remains the tumor suppressor role in gastric cancer as seen in other cancers, we test its function in cell proliferation both at basal and TNF{alpha} mimicked inflammatory condition. Compared with the proliferation inhibitory role observed in basal condition, FOXP3 is insufficient to inhibit the cell proliferation under TNF{alpha} treatment. Molecularly, we found that TNF{alpha} induced an interaction between FOXP3 and p65, which in turn drive the FOXP3 away from the promoter of the well known target p21. Our data here suggest that although FOXP3 is upregulated in gastric cancer, its tumor suppressor role has been dampened due to the inflammation environment.

  3. TNFα induced FOXP3–NFκB interaction dampens the tumor suppressor role of FOXP3 in gastric cancer cells

    International Nuclear Information System (INIS)

    Hao, Qiang; Li, Weina; Zhang, Cun; Qin, Xin; Xue, Xiaochang; Li, Meng; Shu, Zhen; Xu, Tianjiao; Xu, Yujin; Wang, Weihua; Zhang, Wei; Zhang, Yingqi

    2013-01-01

    Highlights: ► FOXP3 inhibition of cell proliferation is p21-dependent under basal conditions. ► Inflammation induced by TNFα inhibits the tumor suppressor role of FOXP3. ► Interaction between p65 and FOXP3 inhibits p21 transcription activation. -- Abstract: Controversial roles of FOXP3 in different cancers have been reported previously, while its role in gastric cancer is largely unknown. Here we found that FOXP3 is unexpectedly upregulated in some gastric cancer cells. To test whether increased FOXP3 remains the tumor suppressor role in gastric cancer as seen in other cancers, we test its function in cell proliferation both at basal and TNFα mimicked inflammatory condition. Compared with the proliferation inhibitory role observed in basal condition, FOXP3 is insufficient to inhibit the cell proliferation under TNFα treatment. Molecularly, we found that TNFα induced an interaction between FOXP3 and p65, which in turn drive the FOXP3 away from the promoter of the well known target p21. Our data here suggest that although FOXP3 is upregulated in gastric cancer, its tumor suppressor role has been dampened due to the inflammation environment.

  4. Utility of P19 Gene-Silencing Suppressor for High Level Expression of Recombinant Human Therapeutic Proteins in Plant Cells

    Directory of Open Access Journals (Sweden)

    Maryam Zangi

    2016-07-01

    Full Text Available Background: The potential of plants, as a safe and eukaryotic system, is considered in the production of recombinant therapeutic human protein today; but the expression level of heterologous proteins is limited by the post-transcriptional gene silencing (PTGS response in this new technology. The use of viral suppressors of gene silencing can prevent PTGS and improve transient expression level of foreign proteins. In this study, we investigated the effect of p19 silencing suppressor on recombinant human nerve growth factor expression in Nicotiana benthamiana. Materials and Methods: The p19 coding region was inserted in the pCAMBIA using NcoI and BstEII recognition sites. Also, the cloned synthesized recombinant human NGF (rhNGF fragment was cloned directly into PVX vector by ClaI and SalI restriction enzymes. The co-agroinfiltration of rhNGF with p19 viral suppressor of gene silencing was evaluated by dot-blot and SDS-PAGE. The amount of expressed rhNGF protein was calculated by AlphaEaseFC software. Results: Co-agroinfiltration of hNGF with P19 suppressor showed about forty-fold increase (8% total soluble protein (TSP when compared to the absence of P19 suppressor (0.2%TSP. Conclusion: The results presented here confirmed that the use of P19 gene silencing suppressor derived from tomato bushy stunt virus (TBSV could efficiently increase the transient expression of recombinant proteins in Nicotiana benthamiana manifold.

  5. Splenectomy suppresses growth and metastasis of hepatocellular carcinoma through decreasing myeloid-derived suppressor cells in vivo.

    Science.gov (United States)

    Long, Xin; Wang, Jian; Zhao, Jian-Ping; Liang, Hui-Fang; Zhu, Peng; Cheng, Qi; Chen, Qian; Wu, Yan-Hui; Zhang, Zhan-Guo; Zhang, Bi-Xiang; Chen, Xiao-Ping

    2016-10-01

    The function of the spleen in tumor development has been investigated for years. The relationship of the spleen with hepatocellular carcinoma (HCC), a huge health burden worldwide, however, remains unknown. The present study aimed to examine the effect of splenectomy on the development of HCC and the possible mechanism. Mouse hepatic carcinoma lines H22 and Hepa1-6 as well as BALB/c and C57 mice were used to establish orthotopic and metastatic mouse models of liver cancer. Mice were divided into four groups, including control group, splenectomy control group (S group), tumor group (T group) and tumor plus splenectomy group (T+S group). Tumor growth, metastases and overall survival were assessed at determined time points. Meanwhile, myeloid-derived suppressor cells (MDSCs) were isolated from the peripheral blood (PB), the spleen and liver tumors, and then measured by flow cytometery. It was found that liver cancer led to splenomegaly, and increased the percentage of MDSCs in the PB and spleen in the mouse models. Splenectomy inhibited the growth and progression of liver cancer and prolonged the overall survival time of orthotopic and metastatic models, which was accompanied by decreased proportion of MDSCs in the PB and tumors of liver cancer-bearing mouse. It was suggested that splenectomy could be considered an adjuvant therapy to treat liver cancer.

  6. Cystatin D is a candidate tumor suppressor gene induced by vitamin D in human colon cancer cells.

    Science.gov (United States)

    Alvarez-Díaz, Silvia; Valle, Noelia; García, José Miguel; Peña, Cristina; Freije, José M P; Quesada, Víctor; Astudillo, Aurora; Bonilla, Félix; López-Otín, Carlos; Muñoz, Alberto

    2009-08-01

    The active vitamin D metabolite 1alpha,25-dihydroxyvitamin D3 [1alpha,25(OH)2D3] has wide but not fully understood antitumor activity. A previous transcriptomic analysis of 1alpha,25(OH)2D3 action on human colon cancer cells revealed cystatin D (CST5), which encodes an inhibitor of several cysteine proteases of the cathepsin family, as a candidate target gene. Here we report that 1alpha,25(OH)2D3 induced vitamin D receptor (VDR) binding to, and activation of, the CST5 promoter and increased CST5 RNA and protein levels in human colon cancer cells. In cells lacking endogenous cystatin D, ectopic cystatin D expression inhibited both proliferation in vitro and xenograft tumor growth in vivo. Furthermore, cystatin D inhibited migration and anchorage-independent growth, antagonized the Wnt/beta-catenin signaling pathway, and repressed c-MYC expression. Cystatin D repressed expression of the epithelial-mesenchymal transition inducers SNAI1, SNAI2, ZEB1, and ZEB2 and, conversely, induced E-cadherin and other adhesion proteins. CST5 knockdown using shRNA abrogated the antiproliferative effect of 1alpha,25(OH)2D3, attenuated E-cadherin expression, and increased c-MYC expression. In human colorectal tumors, expression of cystatin D correlated with expression of VDR and E-cadherin, and loss of cystatin D correlated with poor tumor differentiation. Based on these data, we propose that CST5 has tumor suppressor activity that may contribute to the antitumoral action of 1alpha,25(OH)2D3 in colon cancer.

  7. Kaempferol Promotes Apoptosis in Human Bladder Cancer Cells by Inducing the Tumor Suppressor, PTEN

    Directory of Open Access Journals (Sweden)

    Liqun Zhou

    2013-10-01

    Full Text Available Kaempferol (Kae, a natural flavonoid, is widely distributed in fruits and vegetables. Previous studies have identified Kae as a possible cancer preventive and therapeutic agent. We found Kae to exhibit potent antiproliferation and anti-migration effects in human bladder cancer EJ cells. Kaempferol robustly induced apoptosis in EJ cells in a dose-dependent manner, as evidenced by increased cleavage of caspase-3. Furthermore, we found Kae-induced apoptosis in EJ cells to be associated with phosphatase and the tensin homolog deleted on the chromosome 10 (PTEN/PI3K/Akt pathway. Kae significantly increased PTEN and decreased Akt phosphorylation. Kae-induced apoptosis was partially attenuated in PTEN-knockdown cells. Our findings indicate that Kae could be an alternative medicine for bladder cancer, based on a PTEN activation mechanism.

  8. Arctigenin from Fructus Arctii is a novel suppressor of heat shock response in mammalian cells

    Science.gov (United States)

    Ishihara, Keiichi; Yamagishi, Nobuyuki; Saito, Youhei; Takasaki, Midori; Konoshima, Takao; Hatayama, Takumi

    2006-01-01

    Because heat shock proteins (Hsps) are involved in protecting cells and in the pathophysiology of diseases such as inflammation, cancer, and neurodegenerative disorders, the use of regulators of the expression of Hsps in mammalian cells seems to be useful as a potential therapeutic modality. To identify compounds that modulate the response to heat shock, we analyzed several natural products using a mammalian cell line containing an hsp promoter-regulated reporter gene. In this study, we found that an extract from Fructus Arctii markedly suppressed the expression of Hsp induced by heat shock. A component of the extract arctigenin, but not the component arctiin, suppressed the response at the level of the activation of heat shock transcription factor, the induction of mRNA, and the synthesis and accumulation of Hsp. Furthermore, arctigenin inhibited the acquisition of thermotolerance in mammalian cells, including cancer cells. Thus, arctigenin seemed to be a new suppressive regulator of heat shock response in mammalian cells, and may be useful for hyperthermia cancer therapy. PMID:16817321

  9. Prognostic Significance of Monocytes and Monocytic Myeloid-Derived Suppressor Cells in Diffuse Large B-Cell Lymphoma Treated with R-CHOP

    Directory of Open Access Journals (Sweden)

    Chongyang Wu

    2016-07-01

    Full Text Available Background/Aims: To evaluate the prognostic significance of monocytes and monocytic myeloid-derived suppressor cells (M-MDSCs for patients with diffuse large B-cell lymphoma (DLBCL under R-CHOP chemotherapy. Methods: Flow cytometry (FCM was applied to measure M-MDSCs (CD14+ HLA-DRlow/− M-MDSCs. Results: Analysis of 144 patients with DLBCL under R-CHOP treatment showed that the 5-year overall survival rate was 61.09% (95% CI: 43.72%-72.56% and the average survival time of patients with monocytes (% ≥ 8% was shorter than those with monocytes (% 2 (P = 0.0397, meanwhile, there was no significant difference in survival of patients with monocytes (% ≥ 8% compared to patients with monocytes (% Conclusion: Our results indicated that monocytes (% and M-MDSCs combined with R-IPI may be a simple and efficient immunological index to evaluate prognosis.

  10. Folliculin, the product of the Birt-Hogg-Dube tumor suppressor gene, interacts with the adherens junction protein p0071 to regulate cell-cell adhesion.

    Directory of Open Access Journals (Sweden)

    Doug A Medvetz

    Full Text Available Birt-Hogg-Dube (BHD is a tumor suppressor gene syndrome associated with fibrofolliculomas, cystic lung disease, and chromophobe renal cell carcinoma. In seeking to elucidate the pathogenesis of BHD, we discovered a physical interaction between folliculin (FLCN, the protein product of the BHD gene, and p0071, an armadillo repeat containing protein that localizes to the cytoplasm and to adherens junctions. Adherens junctions are one of the three cell-cell junctions that are essential to the establishment and maintenance of the cellular architecture of all epithelial tissues. Surprisingly, we found that downregulation of FLCN leads to increased cell-cell adhesion in functional cell-based assays and disruption of cell polarity in a three-dimensional lumen-forming assay, both of which are phenocopied by downregulation of p0071. These data indicate that the FLCN-p0071 protein complex is a negative regulator of cell-cell adhesion. We also found that FLCN positively regulates RhoA activity and Rho-associated kinase activity, consistent with the only known function of p0071. Finally, to examine the role of Flcn loss on cell-cell adhesion in vivo, we utilized keratin-14 cre-recombinase (K14-cre to inactivate Flcn in the mouse epidermis. The K14-Cre-Bhd(flox/flox mice have striking delays in eyelid opening, wavy fur, hair loss, and epidermal hyperplasia with increased levels of mammalian target of rapamycin complex 1 (mTORC1 activity. These data support a model in which dysregulation of the FLCN-p0071 interaction leads to alterations in cell adhesion, cell polarity, and RhoA signaling, with broad implications for the role of cell-cell adhesion molecules in the pathogenesis of human disease, including emphysema and renal cell carcinoma.

  11. Hsa-let-7a functions as a tumor suppressor in renal cell carcinoma cell lines by targeting c-myc

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yongchao; Yin, Bingde; Zhang, Changcun; Zhou, Libin [Department of Urology, Shanghai First People' s Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200080 (China); Fan, Jie, E-mail: jief67@sina.com [Department of Urology, Shanghai First People' s Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200080 (China)

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer This study is the first to test the let-7a/c-myc loop in renal cell carcinoma cell lines. Black-Right-Pointing-Pointer Let-7a down-regulated c-myc in three renal cell carcinoma cell lines. Black-Right-Pointing-Pointer c-myc target genes were down-regulated because of the let-7a-mediated down-regulation of c-myc. Black-Right-Pointing-Pointer The let-7a/c-myc loop has a significant function in renal cell carcinoma cell lines. -- Abstract: Widespread functions of the c-myc pathway play a crucial role in renal cell carcinoma (RCC) carcinogenesis. Thus, we evaluated the connection between proto-oncogenic c-myc and anti-neoplastic hsa-let-7a (let-7a) in RCC cell lines. The levels of c-myc and let-7a in 3 RCC cell lines (769P, Caki-1 and 786O) were measured after transfecting the cells with let-7a mimics or a negative control. The change in c-myc protein level was confirmed by Western blot. The anti-neoplastic function of let-7a was evaluated using cell counting kit-8 (CCK-8) for proliferation analysis and cell flow cytometry for cell cycle analysis. The changes of downstream targets of c-myc were measured using reverse transcription quantitative real-time PCR (qRT-PCR). Our results suggest for the first time that let-7a acts as a tumor suppressor in RCC cell lines by down-regulating c-myc and c-myc target genes such as proliferating cell nuclear antigen (PCNA), cyclin D1 (CCND1) and the miR17-92 cluster, which is accompanied by proliferation inhibition and cell cycle arrest.

  12. In vivo evidence for CD4+ and CD8+ suppressor T cells in vaccination-induced suppression of murine experimental autoimmune thyroiditis

    International Nuclear Information System (INIS)

    Flynn, J.C.; Kong, Y.C.

    1991-01-01

    In several experimental autoimmune diseases, including experimental autoimmune thyroiditis (EAT), vaccination with attenuated autoantigen-specific T cells has provided protection against subsequent induction of disease. However, the mechanism(s) of vaccination-induced suppression remains to be clarified. Since the authors have previously shown that suppression generated by pretreatment with mouse thyroglobulin (MTg) or thyroid-stimulating hormone in EAT is mediated by CD4+, not CD8+, suppressor T cells, they examined the role of T cell subsets in vaccination-induced suppression of EAT. Mice were vaccinated with irradiated, MTg-primed, and MTg-activated spleen cells and then challenged. Pretreatment with these cells suppressed EAT induced by immunization with MTg and adjuvant, but not by adoptive transfer of thyroiditogenic cells, suggesting a mechanism of afferent suppression. The activation of suppressor mechanisms did not require CD8+ cells, since mice depleted of CD8+ cells before vaccination showed reduced EAT comparable to control vaccinated mice. Furthermore, depletion of either the CD4+ or the CD8+ subset after vaccination did not significantly abrogate suppression. However, suppression was eliminated by the depletion of both CD4+ and CD8+ cells in vaccinated mice. These results provide evidence for the cooperative effects of CD4+ and CD8+ T cells in vaccination-induced suppression of EAT

  13. Myeloid derived suppressor cells (MDSCs are increased and exert immunosuppressive activity together with polymorphonuclear leukocytes (PMNs in chronic myeloid leukemia patients.

    Directory of Open Access Journals (Sweden)

    Cesarina Giallongo

    Full Text Available Tumor immune tolerance can derive from the recruitment of suppressor cell population, including myeloid derived suppressor cells (MDSCs, able to inhibit T cells activity. We identified a significantly expanded MDSCs population in chronic myeloid leukemia (CML patients at diagnosis that decreased to normal levels after imatinib therapy. In addition, expression of arginase 1 (Arg1 that depletes microenvironment of arginine, an essential aminoacid for T cell function, resulted in an increase in patients at diagnosis. Purified CML CD11b+CD33+CD14-HLADR- cells markedly suppressed normal donor T cell proliferation in vitro. Comparing CML Gr-MDSCs to autologous polymorphonuclear leukocytes (PMNs we observed a higher Arg1 expression and activity in PMNs, together with an inhibitory effect on T cells in vitro. Our data indicate that CML cells create an immuno-tolerant environment associated to MDSCs expansion with immunosuppressive capacity mediated by Arg1. In addition, we demonstrated for the first time also an immunosuppressive activity of CML PMNs, suggesting a strong potential immune escape mechanism created by CML cells, which control the anti-tumor reactive T cells. MDSCs should be monitored in imatinib discontinuation trials to understand their importance in relapsing patients.

  14. Suppressor cell mediated regulation of delayed-type hypersensitivity to histocompatibility antigens

    NARCIS (Netherlands)

    A. Molendijk (Arie)

    1987-01-01

    textabstractDTH to allogeneic histocompatibility antigens is a T cell dependent reaction, which can be induced in immunologically competent individuals by subcutaneous (s.c.) or intravenous (i.v.) administration of alloantigens (Vander Kwast and Benner, 1978; Bianchi et al., 1984). After

  15. Renal Cell Regulation and Cancer: Tumor Suppressor Networks and the Primary Cilium

    NARCIS (Netherlands)

    Klasson, TD

    2017-01-01

    Cancer affects a large number of people the world over. Cancer is a class of extremely complex diseases that arise from malfunctions in otherwise vital cellular processes, especially those that govern aspects of cellular functions like proliferation, apoptosis or the cell cycle. These processes are

  16. Increased circulating FOXP3+ T-cells in patients with granulomatosis with polyangiitis are attributed to an increase in the non-suppressor FOXP3LOW CD45RO+ treg cell subpopulation

    NARCIS (Netherlands)

    Abdulahad, Wayel H.; Stegeman, Coen A.; Huitema, Minke G.; Rutgers, Abraham; Heeringa, Peter; Limburg, Pieter C.; Kallenberg, Cees G.M.

    2012-01-01

    Background/Purpose: Human FoxP3+T-cells are functionally heterogeneous, and can be classified into three phenotypically distinct subpopulations based on the expression levels of FoxP3 and the memory T-cell marker CD45RO. These three subpopulations can be defined as: activated suppressor TRegs

  17. Tumor suppressor ING4 inhibits estrogen receptor activity in breast cancer cells

    Directory of Open Access Journals (Sweden)

    Keenen MM

    2016-11-01

    Full Text Available Madeline M Keenen,1 Suwon Kim1,2 1Department of Basic Medical Sciences, University of Arizona College of Medicine – Phoenix, Phoenix, AZ, 2Division of Cancer and Cell Biology, Translational Genomics Research Institute, Phoenix, AZ, USA Abstract: Resistance to antiestrogen therapy remains a significant problem in breast cancer. Low expression of inhibitor of growth 4 (ING4 in primary tumors has been correlated with increased rates of recurrence in estrogen receptor-positive (ER+ breast cancer patients, suggesting a role for ING4 in ER signaling. This study provides evidence that ING4 inhibits ER activity. ING4 overexpression increased the sensitivity of T47D and MCF7 ER+ breast cancer cells to hormone deprivation. ING4 attenuated maximal estrogen-dependent cell growth without affecting the dose–response of estrogen. These results indicated that ING4 functions as a noncompetitive inhibitor of estrogen signaling and may inhibit estrogen-independent ER activity. Supportive of this, treatment with fulvestrant but not tamoxifen rendered T47D cells sensitive to hormone deprivation as did ING4 overexpression. ING4 did not affect nuclear ERα protein expression, but repressed selective ER-target gene transcription. Taken together, these results demonstrated that ING4 inhibited estrogen-independent ER activity, suggesting that ING4-low breast tumors recur faster due to estrogen-independent ER activity that renders tamoxifen less effective. This study puts forth fulvestrant as a proposed therapy choice for patients with ING4-low ER+ breast tumors. Keywords: tamoxifen resistance, transcription repression, PDZK1, TFF1, estrogen independent ERa, fulvestrant  

  18. Myeloid-derived suppressor cells in cancer cachexia syndrome: a new explanation for an old problem.

    Science.gov (United States)

    Winfield, Robert D; Delano, Matthew J; Pande, Kalyan; Scumpia, Philip O; Laface, Drake; Moldawer, Lyle L

    2008-01-01

    Cachexia accompanies many chronic inflammatory diseases, including cancer. Lean tissue wasting is only one component of the cancer cachexia response, which also includes anemia, anorexia, a hepatic acute phase protein response, and increased susceptibility to secondary infections. The etiologies of cancer cachexia are multifactorial and include an overproduction of inflammatory mediators, including cytokines produced by inappropriate activation of innate immunity. However, anticytokine therapies have generally not been seriously considered for cancer cachexia, in large part because of the overlapping activities of several inflammatory cytokines and the inability to prospectively identify the contributions of individual mediators. In contrast, recent evidence has focused on an immature myeloid cell population that expands dramatically in the tumors and secondary lymphoid organs of animals with some actively growing tumors. These immature GR-1(+)CD11b(+) cells are metabolically active and secrete large quantities of inflammatory cytokines and chemokines with the potential to produce cachexia. Their expansion is temporally associated with the development of cachexia. Future studies are required to determine whether therapeutic efforts intended to block the expansion of these cells can prevent the lean tissue wasting that accompanies active tumor growth.

  19. The effect of age at exposure on the inactivating mechanisms and relative contributions of key tumor suppressor genes in radiation-induced mouse T-cell lymphomas

    International Nuclear Information System (INIS)

    Sunaoshi, Masaaki; Amasaki, Yoshiko; Hirano-Sakairi, Shinobu; Blyth, Benjamin J.; Morioka, Takamitsu; Kaminishi, Mutsumi; Shang, Yi; Nishimura, Mayumi; Shimada, Yoshiya; Tachibana, Akira

    2015-01-01

    Highlights: • T-cell lymphoma incidence, latency and weight did not change with age at exposure. • Lymphomas had frequent loss of heterozygosity on chromosomes 4, 11 and 19. • These lesions targeted the Cdkn2a, Ikaros and Pten tumor suppressor genes. • Age at exposure may influence which tumor suppressor genes are lost in each tumor. • The mechanisms of tumor suppressor gene loss were different at each locus. - Abstract: Children are considered more sensitive to radiation-induced cancer than adults, yet any differences in genomic alterations associated with age-at-exposure and their underlying mechanisms remain unclear. We assessed genome-wide DNA copy number and mutation of key tumor suppressor genes in T-cell lymphomas arising after weekly irradiation of female B6C3F1 mice with 1.2 Gy X-rays for 4 consecutive weeks starting during infancy (1 week old), adolescence (4 weeks old) or as young adults (8 weeks old). Although T-cell lymphoma incidence was similar, loss of heterozygosity at Cdkn2a on chromosome 4 and at Ikaros on chromosome 11 was more frequent in the two older groups, while loss at the Pten locus on chromosome 19 was more frequent in the infant-irradiated group. Cdkn2a and Ikaros mutation/loss was a common feature of the young adult-irradiation group, with Ikaros frequently (50%) incurring multiple independent hits (including deletions and mutations) or suffering a single hit predicted to result in a dominant negative protein (such as those lacking exon 4, an isoform we have designated Ik12, which lacks two DNA binding zinc-finger domains). Conversely, Pten mutations were more frequent after early irradiation (60%) than after young adult-irradiation (30%). Homozygous Pten mutations occurred without DNA copy number change after irradiation starting in infancy, suggesting duplication of the mutated allele by chromosome mis-segregation or mitotic recombination. Our findings demonstrate that while deletions on chromosomes 4 and 11 affecting Cdkn2

  20. The effect of age at exposure on the inactivating mechanisms and relative contributions of key tumor suppressor genes in radiation-induced mouse T-cell lymphomas

    Energy Technology Data Exchange (ETDEWEB)

    Sunaoshi, Masaaki [Radiobiology for Children' s Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Department of Biological Sciences, College of Science, Ibaraki University, Bunkyo 2-1-1, Mito, Ibaraki 310-8512 (Japan); Amasaki, Yoshiko; Hirano-Sakairi, Shinobu; Blyth, Benjamin J. [Radiobiology for Children' s Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Morioka, Takamitsu [Radiobiology for Children' s Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Radiation Effect Accumulation and Prevention Project, Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Kaminishi, Mutsumi [Radiobiology for Children' s Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Shang, Yi [Radiation Effect Accumulation and Prevention Project, Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Nishimura, Mayumi; Shimada, Yoshiya [Radiobiology for Children' s Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Radiation Effect Accumulation and Prevention Project, Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Tachibana, Akira [Department of Biological Sciences, College of Science, Ibaraki University, Bunkyo 2-1-1, Mito, Ibaraki 310-8512 (Japan); and others

    2015-09-15

    Highlights: • T-cell lymphoma incidence, latency and weight did not change with age at exposure. • Lymphomas had frequent loss of heterozygosity on chromosomes 4, 11 and 19. • These lesions targeted the Cdkn2a, Ikaros and Pten tumor suppressor genes. • Age at exposure may influence which tumor suppressor genes are lost in each tumor. • The mechanisms of tumor suppressor gene loss were different at each locus. - Abstract: Children are considered more sensitive to radiation-induced cancer than adults, yet any differences in genomic alterations associated with age-at-exposure and their underlying mechanisms remain unclear. We assessed genome-wide DNA copy number and mutation of key tumor suppressor genes in T-cell lymphomas arising after weekly irradiation of female B6C3F1 mice with 1.2 Gy X-rays for 4 consecutive weeks starting during infancy (1 week old), adolescence (4 weeks old) or as young adults (8 weeks old). Although T-cell lymphoma incidence was similar, loss of heterozygosity at Cdkn2a on chromosome 4 and at Ikaros on chromosome 11 was more frequent in the two older groups, while loss at the Pten locus on chromosome 19 was more frequent in the infant-irradiated group. Cdkn2a and Ikaros mutation/loss was a common feature of the young adult-irradiation group, with Ikaros frequently (50%) incurring multiple independent hits (including deletions and mutations) or suffering a single hit predicted to result in a dominant negative protein (such as those lacking exon 4, an isoform we have designated Ik12, which lacks two DNA binding zinc-finger domains). Conversely, Pten mutations were more frequent after early irradiation (60%) than after young adult-irradiation (30%). Homozygous Pten mutations occurred without DNA copy number change after irradiation starting in infancy, suggesting duplication of the mutated allele by chromosome mis-segregation or mitotic recombination. Our findings demonstrate that while deletions on chromosomes 4 and 11 affecting Cdkn2

  1. The protumorigenic potential of FTY720 by promoting extramedullary hematopoiesis and MDSC accumulation.

    Science.gov (United States)

    Li, Y; Zhou, T; Wang, Y; Ning, C; Lv, Z; Han, G; Morris, J C; Taylor, E N; Wang, R; Xiao, H; Hou, C; Ma, Y; Shen, B; Feng, J; Guo, R; Li, Y; Chen, G

    2017-06-29

    FTY720 (also called fingolimod) is recognized as an immunosuppressant and has been approved by the Food and Drug Administration to treat refractory multiple sclerosis. However, long-term administration of FTY720 potentially increases the risk for cancer in recipients. The underlying mechanisms remain poorly understood. Herein, we provided evidence that FTY720 administration potentiated tumor growth. Mechanistically, FTY720 enhanced extramedullary hematopoiesis and massive accumulation of myeloid-derived suppressor cells (MDSCs), which actively suppressed antitumor immune responses. Granulocyte-macrophage colony-stimulating factor (GM-CSF), mainly produced by MDSCs, was identified as a key factor to mediate these effects of FTY720 in tumor microenvironment. Furthermore, we showed that FTY720 triggers MDSCs to release GM-CSF via S1P receptor 3 (S1pr3) through Rho kinase and extracellular signal-regulated kinase-dependent pathway. Thus, our findings provide mechanistic explanation for the protumorigenic potentials of FTY720 and suggest that targeting S1pr3 simultaneously may be beneficial for the patients receiving FTY720 treatment.

  2. Functional Studies on Primary Tubular Epithelial Cells Indicate a Tumor Suppressor Role of SETD2 in Clear Cell Renal Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Jun Li

    2016-06-01

    Full Text Available SET domain-containing 2 (SETD2 is responsible for the trimethylation of histone H3 lysine36 (H3K36me3 and is one of the genes most frequently mutated in clear cell renal cell carcinoma (ccRCC. It is located at 3p21, one copy of which is lost in the majority of ccRCC tumors, suggesting that SETD2 might function as a tumor suppressor gene. However, the manner in which loss of SETD2 contributes to ccRCC development has not been studied in renal primary tubular epithelial cells (PTECs. Therefore, we studied the consequences of SETD2 knockdown through lentiviral shRNA in human PTECs. Consistent with its known function, SETD2 knockdown (SETD-KD led to loss of H3K36me3 in PTECs. In contrast to SETD2 wild-type PTECs, which have a limited proliferation capacity; the SETD2-KD PTECs continued to proliferate. The expression profiles of SETD2-KD PTECs showed a large overlap with the expression profile of early-passage, proliferating PTECs, whereas nonproliferating PTECs showed a significantly different expression profile. Gene set enrichment analysis revealed a significant enrichment of E2F targets in SETD2-KD and proliferating PTECs as compared with nonproliferating PTECs and in proliferating PTEC compared with SETD2-KD. The SETD2-KD PTECs maintained low expression of CDKN2A and high expression of E2F1, whereas their levels changed with continuing passages in untreated PTECs. In contrast to the nonproliferating PTECs, SETD2-KD PTECs showed no β-galactosidase staining, confirming the protection against senescence. Our results indicate that SETD2 inactivation enables PTECs to bypass the senescence barrier, facilitating a malignant transformation toward ccRCC.

  3. Tumor suppressor PDCD4 modulates miR-184-mediated direct suppression of C-MYC and BCL2 blocking cell growth and survival in nasopharyngeal carcinoma.

    Science.gov (United States)

    Zhen, Yan; Liu, Zhen; Yang, Huiling; Yu, Xiaoli; Wu, Qiangyun; Hua, Shengni; Long, Xiaobin; Jiang, Qingping; Song, Ye; Cheng, Chao; Wang, Hao; Zhao, Menyang; Fu, Qiaofen; Lyu, Xiaoming; Chen, Yiyu; Fan, Yue; Liu, Yan; Li, Xin; Fang, Weiyi

    2013-10-24

    Programmed cell death 4 (PDCD4), a novel tumor suppressor, inhibits cell proliferation, migration and invasion as well as promotes cell apoptosis in tumors. However, the molecular mechanism of its tumor-suppressive function remains largely unknown in tumors including nasopharyngeal carcinoma (NPC). In this study, downregulated PDCD4 expression was significantly associated with the status of NPC progression and poor prognosis. PDCD4 markedly suppressed the ability of cell proliferation and cell survival by modulating C-MYC-controlled cell cycle and BCL-2-mediated mitochondrion apoptosis resistance signals, and oncogenic transcription factor C-JUN in NPC. Furthermore, miR-184, a tumor-suppressive miRNA modulated by PDCD4 directly targeting BCL2 and C-MYC, participated in PDCD4-mediated suppression of cell proliferation and survival in NPC. Further, we found that PDCD4 decreased the binding of C-Jun to the AP-1 element on the miR-184 promoter regions by PI3K/AKT/JNK/C-Jun pathway and stimulated miR-184 expression. In clinical fresh specimens, reduced PDCD4 mRNA level was positively correlated with miR-184 expression in NPC. Our studies are the first to demonstrate that PDCD4 as tumor suppressor regulated miR-184-mediated direct targeting of BCL2 and C-MYC via PI3K/AKT and JNK/C-Jun pathway attenuating cell proliferation and survival in NPC.

  4. Indomethacin sensitive suppressor cell activity in head and neck cancer patients pre- and postirradiation therapy

    International Nuclear Information System (INIS)

    Maca, R.D.; Panje, W.R.

    1982-01-01

    The effects of the addition of indomethacin to PHA or Con A stimulated lymphocytes from patients with untreated squamous cell carcinoma of the head and neck or from patients with the disease who have just finished irradiation therapy from the disease was quantitated and compared to those of the control group. Lymphocytes from eight of 26 patients with untreated carcinoma were significantly augmented by the addition of indomethacin. The remaining eighteen patients were equal to the controls. For all 17 patients who had just finished extensive field irradiation therapy, significant enhancement of PHA and Con A reactivity by indomethacin was found, which did not appear to be solely a function of low baseline mitogen reactivity. The results of this study support the hypothesis that perhaps patients receiving irradiation therapy may benefit by the oral administration of indomethacin, an approach that needs further consideration

  5. Immunomodulatory effect of captopril and local irradiation on myeloid-derived suppressor cells

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Won Kyung; Shin, Sung Won; Kim, Shin Yeong; Choi, Chang Hoon; Park, Won; Noh, Jae Myoung [Dept. of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Hong, Chang Won [Dept. of Physiology, Kyungpook National University School of Medicine, Daegu (Korea, Republic of)

    2016-09-15

    This study is to investigate the effect of captopril when combined with irradiation. 4T1 (mouse mammary carcinoma) cells were injected in the right hind leg of Balb/c mice. Mice were randomized to four groups; control (group 1), captopril-treated (group 2), irradiated (group 3), irradiated and captopril-treated concurrently (group 4). Captopril was administered by intraperitoneal injection (10 mg/kg) daily and irradiation was delivered on the tumor-bearing leg for 15 Gy in 3 fractions. Surface markers of splenic neutrophils (G-MDSCs) and intratumoral neutrophils (tumor-associated neutrophils [TANs]) were assessed using flow cytometry and expression of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor 1 alpha (HIF-1α) of tumor was evaluated by immunohistochemical (IHC) staining. The mean tumor volumes (±standard error) at the 15th day after randomization were 1,382.0 (±201.2) mm{sup 3} (group 1), 559.9 (±67.8) mm{sup 3} (group 3), and 370.5 (± 48.1) mm{sup 3} (group 4), respectively. For G-MDSCs, irradiation reversed decreased expression of CD{sub 101} from tumor-bearing mice, and additional increase of CD{sub 101} expression was induced by captopril administration. Similar tendency was observed in TANs. The expression of tumor-necrosis factor-associated molecules, CD{sub 120} and CD{sub 137}, are increased by irradiation in both G-MDSCs and TANs. Further increment was observed by captopril except CD{sub 120} in TANs. For IHC staining, VEGF and HIF-1α positivity in tumor cells were decreased when treated with captopril. Captopril is suggested to have additional effect when combined to irradiation in a murine tumor model by modulation of MDSCs and angiogenesis.

  6. Blood CD33(+)HLA-DR(-) myeloid-derived suppressor cells are increased with age and a history of cancer.

    Science.gov (United States)

    Verschoor, Chris P; Johnstone, Jennie; Millar, Jamie; Dorrington, Michael G; Habibagahi, Mojtaba; Lelic, Alina; Loeb, Mark; Bramson, Jonathan L; Bowdish, Dawn M E

    2013-04-01

    As we age, the composition of our peripheral leukocytes changes dramatically. Many of these alterations contribute to the general immune dysfunction that burdens the elderly, which in turn, contributes to increased susceptibility to disease. MDSCs represent a heterogeneous population of immunosuppressive leukocytes that are elevated in the peripheral blood of cancer patients. Given the relation between cancer incidence and age, this study examined the frequency of peripheral blood CD33(+)HLA-DR(-) MDSCs across three cohorts: healthy adults (19-59 years old), community-dwelling seniors (61-76 years old), and frail elderly (67-99 years old). This analysis is the first to demonstrate that MDSCs and specifically the CD11b(+)CD15(+) MDSC subset are increased with age. Proinflammatory cytokines that are required for the differentiation of MDSCs (e.g., TNF-α, IL-6, and IL-1β) were similarly found to be increased in the serum of the frail elderly. Furthermore, the proportion of MDSCs and the CD11b(+)CD15(+) subset were found to be elevated significantly in elderly donors with a history of cancer. This age-related elevation in the frequency of MDSCs may contribute to the increased cancer incidence that occurs with age. Further investigation into the functional consequences of elevated MDSCs will provide valuable insight into the progression of age-related pathologies.

  7. Indomethacin sensitive suppressor cell activity in head and neck cancer patients pre- and postirradiation therapy

    International Nuclear Information System (INIS)

    Maca, R.D.; Panje, W.R.

    1982-01-01

    The effects of the addition of indomethacin to PHA or Con A stimulated lymphocytes from patients with untreated squamous cell carcinoma of the head and neck or from patients with the disease who have just finished irradiation therapy from the disease was quantitated and compared to those of the control group. Lymphocytes from eight of 26 patients with untreated carcinoma were significantly augmented by the addition of indomethacin. The remaining eighteen patients were equal to the controls. For all 17 patients who had just finished extensive field irradiation therapy, significant enhancement of PHA and Con A reactivity by indomethacin was found, which did not appear to be solely a function of low baseline mitogen reactivity. In additional studies, stimulated lymphocytes of irradiated patients were tested for their sensitivity to the inhibitory effect of PGE2. The mitogen treated lymphocytes from all patients that had just finished irradiation therapy were found to be significantly more sensitive to the inhibition by PGE2 as compared to the normal lymphocyte response. This effect was also found not to be related merely to a low PHA or Con A reactivity of the lymphocytes. The results of this study support the hypothesis that perhaps patients receiving irradiation therapy may benefit by the oral administration of indomethacin, an approach that needs further consideration

  8. Tumor suppressors: enhancers or suppressors of regeneration?

    Science.gov (United States)

    Pomerantz, Jason H.; Blau, Helen M.

    2013-01-01

    Tumor suppressors are so named because cancers occur in their absence, but these genes also have important functions in development, metabolism and tissue homeostasis. Here, we discuss known and potential functions of tumor suppressor genes during tissue regeneration, focusing on the evolutionarily conserved tumor suppressors pRb1, p53, Pten and Hippo. We propose that their activity is essential for tissue regeneration. This is in contrast to suggestions that tumor suppression is a trade-off for regenerative capacity. We also hypothesize that certain aspects of tumor suppressor pathways inhibit regenerative processes in mammals, and that transient targeted modification of these pathways could be fruitfully exploited to enhance processes that are important to regenerative medicine. PMID:23715544

  9. ß-cell specific overexpression of suppressor of cytokine signalling-3 does not protect against multiple low dose streptozotocin induced type 1 diabetes in mice

    DEFF Research Database (Denmark)

    Börjesson, A; Rønn, S G; Karlsen, A E

    2011-01-01

    We investigated the impact of ß-cell specific overexpression of suppressor of cytokine signalling-3 (SOCS-3) on the development of multiple low dose streptozotocin (MLDSTZ) induced Type 1 diabetes and the possible mechanisms involved. MLDSTZ treatment was administered to RIP-SOCS-3 transgenic......RNA in islet cells and secretion of IL-1Ra into culture medium. MLDSTZ treatment caused gradual hyperglycemia both in the wt mice and in the transgenic mice with the latter tending to be more sensitive. In vitro experiments on wt and transgenic islets did not reveal any differences in sensitivity to damaging...

  10. The long non-coding RNA H19-derived miR-675 modulates human gastric cancer cell proliferation by targeting tumor suppressor RUNX1

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, Ming [Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu (China); Department of Oncology, The First People’s Hospital of Lianyungang, Lianyungang, Jiangsu (China); Gao, Wen; Xu, Jing; Wang, Ping [Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu (China); Shu, Yongqian, E-mail: shuyongqian39000@163.com [Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu (China)

    2014-06-06

    Graphical abstract: - Highlights: • H19 regulates gastric cancer cell proliferation phenotype via miR-675. • MiR-675 modulates cell proliferation of gastric cancer cells by targeting tumor suppressor RUNX1. • The H19/miR-675/RUNX1 axis plays an important role in the tumorigenesis of gastric cancer. - Abstract: The lncRNA H19 has been recently shown to be upregulated and play important roles in gastric cancer tumorigenesis. However, the precise molecular mechanism of H19 and its mature product miR-675 in the carcinogenesis of gastric cancer remains unclear. In this study, we found that miR-675 was positively expressed with H19 and was a pivotal mediator in H19-induced gastric cancer cell growth promotion. Subsequently, the tumor suppressor Runt Domain Transcription Factor1 (RUNX1) was confirmed to be a direct target of miR-675 using a luciferase reporter assay and Western blotting analyses. A series of rescue assays indicated that RUNX1 mediated H19/miR-67-induced gastric cancer cell phenotypic changes. Moreover, the inverse relationship between the expression of RUNX1 and H19/miR-675 was also revealed in gastric cancer tissues and gastric cancer cell lines. Taken together, our study demonstrated that the novel pathway H19/miR-675/RUNX1 regulates gastric cancer development and may serve as a potential target for gastric cancer therapy.

  11. DLC1 tumor suppressor gene inhibits migration and invasion of multiple myeloma cells through RhoA GTPase pathway

    Czech Academy of Sciences Publication Activity Database

    Ullmannová-Benson, Veronika; Guan, M.; Zhou, X. G.; Tripathi, V.; Yang, V.; Zimonjic, D. B.; Popescu, C.

    2009-01-01

    Roč. 23, č. 2 (2009), s. 383-390 ISSN 0887-6924 Institutional research plan: CEZ:AV0Z50200510 Keywords : multiple myeloma * tumor suppressor gene * promoter methylation Subject RIV: EC - Immunology Impact factor: 8.296, year: 2009

  12. Expression of metastasis suppressor BRMS1 in breast cancer cells results in a marked delay in cellular adhesion to matrix

    Science.gov (United States)

    Metastatic dissemination is a multi-step process that depends on cancer cells’ ability to respond to microenvironmental cues by adapting adhesion abilities and undergoing cytoskeletal rearrangement. Breast Cancer Metastasis Suppressor 1 (BRMS1) affects several steps of the metastatic cascade: it dec...

  13. Systemic agonistic anti-CD40 treatment of tumor bearing mice modulates hepatic myeloid suppressive cells and causes immune-mediated liver damage

    Science.gov (United States)

    Medina-Echeverz, José; Ma, Chi; Duffy, Austin; Eggert, Tobias; Hawk, Nga; Kleiner, David E.; Korangy, Firouzeh; Greten, Tim F.

    2015-01-01

    Immune stimulatory monoclonal antibodies are currently evaluated as anti tumor agents. Although overall toxicity appears to be moderate, liver toxicities have been reported and are not completely understood. We studied the effect of systemic CD40 antibody treatment on myeloid cells in spleen and liver. Naïve and tumor-bearing mice were treated systemically with agonistic anti-CD40 antibody. Immune cell subsets in liver and spleen, serum transaminases and liver histologies were analyzed after antibody administration. Nox2−/−, Cd40−/− as well as bone marrow chimeric mice were used to study the mechanism by which agonistic anti-CD40 mediates its effects in vivo. Suppressor function of murine and human tumor-induced myeloid derived suppressive cells was studied upon CD40 ligation. Agonistic CD40 antibody caused liver damage within 24 hours after injection in two unrelated tumor models and mice strains. Using bone marrow chimeras we demonstrated that CD40 antibody-induced hepatitis in tumor-bearing mice was dependent on the presence of CD40-expressing hematopoietic cells. Agonistic CD40 ligation-dependent liver damage was induced by the generation of reactive oxygen species. Furthermore, agonistic CD40 antibody resulted in increased CD80 and CD40 positive liver CD11b+Gr-1+ immature myeloid cells. CD40 ligation on tumor-induced murine and human CD14+HLA-DRlow PBMC from cancer patients reduced their immune suppressor function. Collectively, agonistic CD40 antibody treatment activated tumor-induced, myeloid cells, caused myeloid dependent hepatotoxicity and ameliorated the suppressor function of murine and human MDSC. Collectively, our data suggests that CD40 may mature immunosuppressive myeloid cells and thereby cause liver damage in mice with an accumulation of tumor-induced hepatic MDSC. PMID:25637366

  14. Differential retention of tumor- and differentiation-suppressor functions in cells derived from a human squamous cell carcinoma.

    Science.gov (United States)

    Jaffe, D R; Montero-Puerner, Y; Beckett, M A; Cowan, J M; Weichselbaum, R R; Diamond, A M

    1992-01-01

    Three morphologically distinct cell lines--F.2a, V, and B.2--were isolated from a single human squamous cell carcinoma. Although all three cell lines can grow indefinitely in culture, they differ in a number of important transformation-related phenotypes. Only B.2 is strongly tumorigenic when injected into the flanks of nude mice, and only V can efficiently grow in semisolid media. The dominance of these traits was investigated by generating somatic cell hybrids among the three cell lines. F.2a was able to suppress the tumorigenicity of B.2 cells, whereas B.2 inhibited the capacity for anchorage-independent growth of V, the latter trait being a function of the ability of these epithelial cells to differentiate when deprived of support. The influence of exogenously added growth factors was also evaluated. This study indicates that the particular tumor we examined consisted of a heterogeneous population of cells with distinct growth and differentiation capacities.

  15. Sulforaphane Alone and in Combination with Clofarabine Epigenetically Regulates the Expression of DNA Methylation-Silenced Tumour Suppressor Genes in Human Breast Cancer Cells.

    Science.gov (United States)

    Lubecka-Pietruszewska, Katarzyna; Kaufman-Szymczyk, Agnieszka; Stefanska, Barbara; Cebula-Obrzut, Barbara; Smolewski, Piotr; Fabianowska-Majewska, Krystyna

    2015-01-01

    Sporadic breast cancer is frequently associated with aberrant DNA methylation patterns that are reversible and responsive to environmental factors, including diet. In the present study, we investigated the effects of sulforaphane (SFN), a phytochemical from cruciferous vegetables, on the methylation and expression of PTEN and RARbeta2 tumour suppressor genes as well as on the expression of regulators of DNA methylation reaction, DNMT1 , p53 , and p21 , in MCF-7 and MDA-MB-231 human breast cancer cells with different invasive potential. We also evaluate the role of SFN epigenetic effects in support of therapy with clofarabine (ClF) that was recently shown to modulate the epigenome as well. Promoter methylation and gene expression were estimated using methylation-sensitive restriction analysis and real-time PCR, respectively. In both MCF-7 and MDA-MB-231 cells, SFN at IC 50 (22 and 46 μ M , respectively) and a physiologically relevant 10 μ M concentration lead to hypomethylation of PTEN and RARbeta2 promoters with concomitant gene upregulation. The combination of SFN and ClF enhances these effects, resulting in an increase in cell growth arrest and apoptosis at a non-invasive breast cancer stage. Our findings provide evidence that SFN activates DNA methylation-silenced tumour suppressor genes in breast cancer cells and may contribute to SFN-mediated support of therapy with an anti-cancer drug, ClF, increasing its applications in solid tumours.

  16. Radiation of different human melanoma cell lines increased expression of RHOB. Level of this tumor suppressor gene in different cell lines

    International Nuclear Information System (INIS)

    Notcovich, C.; Molinari, B.; Duran, H.; Delgado González, D.; Sánchez Crespo, R.

    2013-01-01

    Previous results of our group show that a correlation exists between intrinsic radiosensitivity of human melanoma cells and cell death by apoptosis. RhoB is a small GTPase that regulates cytoskeletal organization. Besides, is related to the process of apoptosis in cells exposed to DNA damage as radiation. Also, RhoB levels decrease in a wide variety of tumors with the tumor stage, being considered a tumor suppressor gene due to its antiproliferative and proapoptotic effect. The aim of this study was to analyze the expression of RhoB in different human melanoma cell lines in relation to melanocytes, and evaluate the effect of gamma radiation on the expression of RhoB. We used the A375, SB2 and Meljcell lines, and the derived from melanocytes Pig1. It was found for all three tumor lines RhoB expression levels significantly lower than those of Pig1 (p <0.05), as assessed by semiquantitative RT-PCR . When tumor cells were irradiated to a dose of 2Gyinduction was observed at 3 hours RhoB irradiation. RhoB expression increased in all lines relative to non-irradiated control, showing a greater induction ( p< 0.05) for the more radiosensitive line SB2, consistent with apoptosis in response to radiation. The results allow for the first time in melanoma demonstrate that RhoB, as well as in other tumor types, has a lower expression in tumor cells than their normal counterparts. Moreover, induction in the expression of RhoB in irradiated cells may be associated with the process of radiation-induced apoptosis. The modulation of RhoB could be a new tool to sensitize radioresistant melanoma. (author)

  17. The p75NTR tumor suppressor induces cell cycle arrest facilitating caspase mediated apoptosis in prostate tumor cells

    International Nuclear Information System (INIS)

    Khwaja, Fatima; Tabassum, Arshia; Allen, Jeff; Djakiew, Daniel

    2006-01-01

    The p75 neurotrophin receptor (p75 NTR ) is a death receptor which belongs to the tumor necrosis factor receptor super-family of membrane proteins. This study shows that p75 NTR retarded cell cycle progression by induced accumulation of cells in G0/G1 and a reduction in the S phase of the cell cycle. The rescue of tumor cells from cell cycle progression by a death domain deleted (ΔDD) dominant-negative antagonist of p75 NTR showed that the death domain transduced anti-proliferative activity in a ligand-independent manner. Conversely, addition of NGF ligand rescued retardation of cell cycle progression with commensurate changes in components of the cyclin/cdk holoenzyme complex. In the absence of ligand, p75 NTR -dependent cell cycle arrest facilitated an increase in apoptotic nuclear fragmentation of the prostate cancer cells. Apoptosis of p75 NTR expressing cells occurred via the intrinsic mitochondrial pathway leading to a sequential caspase-9 and -7 cascade. Since the death domain deleted dominant-negative antagonist of p75 NTR rescued intrinsic caspase associated apoptosis in PC-3 cells, this shows p75 NTR was integral to ligand independent induction of apoptosis. Moreover, the ability of ligand to ameliorate the p75 NTR -dependent intrinsic apoptotic cascade indicates that NGF functioned as a survival factor for p75 NTR expressing prostate cancer cells

  18. Tolerance in a rat cardiac allograft model after short-term treatment with LF 08-0299. Absence of clonal deletion and evidence of CD4+ suppressor cells.

    Science.gov (United States)

    Andoins, C; de Fornel, D; Annat, J; Dutartre, P

    1996-12-15

    LF 08-0299 is a new immunosuppressive compound. In a fully mismatched rat cardiac allograft model (Dark Agouti [DA]-->Lewis [LEW]), long-term unresponsiveness was observed after LF 08-0299 short-term treatment (20 days). Survival of additional cardiac and skin DA allografts, and rejection of third-party (Brown Norway [BN]) skin allografts demonstrated induction of a donor-specific tolerance state. The aim of this study was to investigate mechanisms of cardiac acceptance in this model. LEW rats with long-term surviving heart grafts (LTS LEW) were examined for their immune proliferative and cytotoxic responses toward donors (DA) and third-party (BN) antigens. Normal proliferative responses were observed and limiting dilution analysis did not reveal a reduction of T cytotoxic cell precursors. In our model, tolerance exists despite the presence of cells reactive with donor alloantigens. In vivo adoptive transfer of serum from LTS LEW failed to transfer unresponsiveness, indicating that serum factors do not seem to be involved in tolerance maintenance. Transfer of spleen cells, obtained from LTS LEW, showed specific prolongation of DA cardiac allografts in syngeneic hosts. Moreover, these cells were able to induce the rejection of third-party BN grafts. These results suggest that although LTS LEW possessed suppressor cells, they remained immunocompetent in recognizing and responding to third-party alloantigens. Purified CD4+ cells transferred unresponsiveness to secondary hosts, but CD8+ cells did not. Taken together, these results suggest that tolerance to donor alloantigens after treatment with LF 08-0299 in the rat cardiac allograft model is most likely due to induction of specific CD4+ suppressor cell activity, rather than induction of suppressive serum factor and selective elimination of antidonor helper or cytotoxic cell precursors (clonal deletion).

  19. Invariant Natural Killer T Cells As Suppressors of Graft-versus-Host Disease in Allogeneic Hematopoietic Stem Cell Transplantation

    Directory of Open Access Journals (Sweden)

    Melissa Mavers

    2017-07-01

    Full Text Available Invariant natural killer T (iNKT cells serve as a bridge between innate and adaptive immunity and have been shown to play an important role in immune regulation, defense against pathogens, and cancer immunity. Recent data also suggest that this compartment of the immune system plays a significant role in reducing graft-versus-host disease (GVHD in the setting of allogeneic hematopoietic stem cell transplantation. Murine studies have shown that boosting iNKT numbers through certain conditioning regimens or adoptive transfer leads to suppression of acute or chronic GVHD. Preclinical work reveals that iNKT cells exert their suppressive function by expanding regulatory T cells in vivo, though the exact mechanism by which this occurs has yet to be fully elucidated. Human studies have demonstrated that a higher number of iNKT cells in the graft or in the peripheral blood of the recipient post-transplantation are associated with a reduction in GVHD risk, importantly without a loss of graft-versus-tumor effect. In two separate analyses of many immune cell subsets in allogeneic grafts, iNKT cell dose was the only parameter associated with a significant improvement in GVHD or in GVHD-free progression-free survival. Failure to reconstitute iNKT cells following allogeneic transplantation has also been associated with an increased risk of relapse. These data demonstrate that iNKT cells hold promise for future clinical application in the prevention of GVHD in allogeneic stem cell transplantation and warrant further study of the immunoregulatory functions of iNKT cells in this setting.

  20. Tumour suppressor PTEN regulates cell cycle and protein kinase B/Akt pathway in breast cancer cells

    Czech Academy of Sciences Publication Activity Database

    Hlobilková, Alice; Knillová, J.; Šváchová, M.; Skypalová, P.; Kryštof, Vladimír; Kolář, Z.

    2006-01-01

    Roč. 26, 2A (2006), s. 1015-1022 ISSN 0250-7005 R&D Projects: GA MZd NR7828 Institutional research plan: CEZ:AV0Z50380511 Keywords : breast cancer cell lines * cell cycle * phosphatase activity Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.479, year: 2006

  1. Interaction in vivo between hapten-specific suppressor T cells and an in vitro cultured helper T cell line

    DEFF Research Database (Denmark)

    Owens, T; Miller, J F

    1987-01-01

    by trinitrophenyl (TNP)-coupled SC, both Tc responses and their suppression were occasionally nonspecific. Induction of Th was assayed by measuring the release from primed lymph node cells of IL 2 and IL 3 in response to haptenated SC in vitro. Both cytotoxic and Th responses could be made dependent...... on the provision of exogenous Th by reducing the antigen dose. This stratagem allowed the assay in vivo of a long-term cultured ABA-specific Th cell line (E9). Injection of 10(5) E9 cells/mouse (with antigen, in the rear footpad) helped the induction of both Tc and Th in response to a reduced dose of antigen....... The fact that the E9 Th cell line could be suppressed also shows that long-term culture of T cells does not affect their capacity to be regulated in vivo....

  2. Inactivation of a Gα(s)-PKA tumour suppressor pathway in skin stem cells initiates basal-cell carcinogenesis.

    Science.gov (United States)

    Iglesias-Bartolome, Ramiro; Torres, Daniela; Marone, Romina; Feng, Xiaodong; Martin, Daniel; Simaan, May; Chen, Min; Weinstein, Lee S; Taylor, Susan S; Molinolo, Alfredo A; Gutkind, J Silvio

    2015-06-01

    Genomic alterations in GNAS, the gene coding for the Gαs heterotrimeric G protein, are associated with a large number of human diseases. Here, we explored the role of Gαs on stem cell fate decisions by using the mouse epidermis as a model system. Conditional epidermal deletion of Gnas or repression of PKA signalling caused a remarkable expansion of the stem cell compartment, resulting in rapid basal-cell carcinoma formation. In contrast, inducible expression of active Gαs in the epidermis caused hair follicle stem cell exhaustion and hair loss. Mechanistically, we found that Gαs-PKA disruption promotes the cell autonomous Sonic Hedgehog pathway stimulation and Hippo signalling inhibition, resulting in the non-canonical activation of GLI and YAP1. Our study highlights an important tumour suppressive function of Gαs-PKA, limiting the proliferation of epithelial stem cells and maintaining proper hair follicle homeostasis. These findings could have broad implications in multiple pathophysiological conditions, including cancer.

  3. Inactivation of a Gαs-PKA tumor suppressor pathway in skin stem cells initiates basal-cell carcinogenesis

    Science.gov (United States)

    Iglesias-Bartolome, Ramiro; Torres, Daniela; Marone, Romina; Feng, Xiaodong; Martin, Daniel; Simaan, May; Chen, Min; Weinstein, Lee S.; Taylor, Susan S.; Molinolo, Alfredo A.; Gutkind, J. Silvio

    2015-01-01

    Genomic alterations in GNAS, the gene coding for the Gαs heterotrimeric G-protein, are associated with a large number human of diseases. Here, we explored the role of Gαs on stem cell fate decisions by using the mouse epidermis as a model system. Conditional epidermal deletion of Gnas or repression of PKA signaling caused a remarkable expansion of the stem cell compartment, resulting in rapid basal cell carcinoma formation. In contrast, inducible expression of active Gαs in the epidermis caused hair follicle stem cell exhaustion and hair loss. Mechanistically, we found that Gαs-PKA disruption promotes the cell autonomous Sonic Hedgehog pathway stimulation and Hippo signaling inhibition, resulting in the non-canonical activation of GLI and YAP1. Our study highlights an important tumor suppressive function of Gαs-PKA, limiting the proliferation of epithelial stem cells and maintaining proper hair follicle homeostasis. These findings can have broad implications in multiple pathophysiological conditions, including cancer. PMID:25961504

  4. [The expression and association of CD14(+) HLA-DR(Low/-) myeloid-derived suppressor cell-like cells and interleukin-1β in ovarian cancer].

    Science.gov (United States)

    Wang, H Y; Zhao, R; Ren, H; Zou, M J; Zhang, J; Zhang, Y

    2017-09-12

    Objective: To analyze the percentage of CD14(+) HLA-DR(Low/-) myeloid-derived suppressor cell-like cell subtypes(MDSCs) and interleukin-1β(IL-1β) concentration in peripheral blood and ascites of ovarian cancer patients, and to explore their association with clinicopathological characteristics. Methods: Blood samples of 31 patients and ascites of 5 patients in Qilu Hospital of Shandong University from January 2016 to December 2016 were collected. Blood samples of 20 healthy volunteers with matched age were collected as control. The percentages of CD14(+) HLA-DR(Low/-) cell subtypes in CD14(+) monocytes were collected by flow cytometry and their phenotypes were analyzed. qRT-PCR was used to analyze the expression of immunosuppression factors in this subtype. ELISA was used to analyze IL-1β concentration in peripheral blood and ascites of ovarian cancer patients and healthy controls. The correlation between CD14(+) HLA-DR(Low/-) cell percentage and IL-1β concentration was explored. The association between CD14(+) HLA-DR(Low/-) cell percentage, IL-1β concentration and clinicopathological characteristics were analyzed. Results: The percentage of CD14(+) HLA-DR(Low/-) cells in CD14(+) monocytes of peripheral blood of healthy controls was (2.30±0.49)%, and the percentage in ovarian cancer patients was (3.74±0.95)%, with statistical significance ( t =6.96, P HLA-DR(Low/-) cells in peripheral blood ascites of ovarian cancer patients was (16.60±7.35)%, significantly higher than those in peripheral bloods (4.03±0.94)%( t =3.87, P cancer patients was (12.77±3.52) ng/L, with statistical significance ( Z =-4.93, P cancer patients was (62.17±23.05) ng/L, significantly higher than that in peripheral bloods (12.65±3.93) ng/L( t =5.20, P HLA-DR(Low/-) cell percentage in ovarian cancer patients ( R (2)=0.36 in peripheral blood, P 0.05). The percentage of CD14(+) HLA-DR(Low/-) cells and IL-1β concentration were associated with metastasis and FIGO stage of ovarian cancer

  5. IL-7 treatment augments and prolongs sepsis-induced expansion of IL-10-producing B lymphocytes and myeloid-derived suppressor cells.

    Science.gov (United States)

    Kulkarni, Upasana; Herrmenau, Christoph; Win, Stephanie J; Bauer, Michael; Kamradt, Thomas

    2018-01-01

    Immunological dysregulation in sepsis is associated with often lethal secondary infections. Loss of effector cells and an expansion of immunoregulatory cell populations both contribute to sepsis-induced immunosuppression. The extent and duration of this immunosuppression are unknown. Interleukin 7 (IL-7) is important for the maintenance of lymphocytes and can accelerate the reconstitution of effector lymphocytes in sepsis. How IL-7 influences immunosuppressive cell populations is unknown. We have used the mouse model of peritoneal contamination and infection (PCI) to investigate the expansion of immunoregulatory cells as long-term sequelae of sepsis with or without IL-7 treatment. We analysed the frequencies and numbers of regulatory T cells (Tregs), double negative T cells, IL-10 producing B cells and myeloid-derived suppressor cells (MDSCs) for 3.5 months after sepsis induction. Sepsis induced an increase in IL-10+ B cells, which was enhanced and prolonged by IL-7 treatment. An increased frequency of MDSCs in the spleen was still detectable 3.5 months after sepsis induction and this was more pronounced in IL-7-treated mice. MDSCs from septic mice were more potent at suppressing T cell proliferation than MDSCs from control mice. Our data reveal that sepsis induces a long lasting increase in IL-10+ B cells and MDSCs. Late-onset IL-7 treatment augments this increase, which should be relevant for clinical interventions.

  6. Antiviral signaling protein MITA acts as a tumor suppressor in breast cancer by regulating NF-κB induced cell death.

    Science.gov (United States)

    Bhatelia, Khyati; Singh, Aru; Tomar, Dhanendra; Singh, Kritarth; Sripada, Lakshmi; Chagtoo, Megha; Prajapati, Paresh; Singh, Rochika; Godbole, Madan M; Singh, Rajesh

    2014-02-01

    Emerging evidences suggest that chronic inflammation is one of the major causes of tumorigenesis. The role of inflammation in regulation of breast cancer progression is not well established. Recently Mediator of IRF3 Activation (MITA) protein has been identified that regulates NF-κB and IFN pathways. Role of MITA in the context of inflammation and cancer progression has not been investigated. In the current report, we studied the role of MITA in the regulation of cross talk between cell death and inflammation in breast cancer cells. The expression of MITA was significantly lower on in estrogen receptor (ER) positive breast cancer cells than ER negative cells. Similarly, it was significantly down regulated in tumor tissue as compared to the normal tissue. The overexpression of MITA in MCF-7 and T47D decreases the cell proliferation and increases the cell death by activation of caspases. MITA positively regulates NF-κB transcription factor, which is essential for MITA induced cell death. The activation of NF-κB induces TNF-α production which further sensitizes MITA induced cell death by activation of death receptor pathway through capsase-8. MITA expression decreases the colony forming units and migration ability of MCF-7 cells. Thus, our finding suggests that MITA acts as a tumor suppressor which is down regulated during tumorigenesis providing survival advantage to tumor cell. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. The von Hippel-Lindau tumor suppressor gene inhibits hepatocyte growth factor/scatter factor-induced invasion and branching morphogenesis in renal carcinoma cells.

    Science.gov (United States)

    Koochekpour, S; Jeffers, M; Wang, P H; Gong, C; Taylor, G A; Roessler, L M; Stearman, R; Vasselli, J R; Stetler-Stevenson, W G; Kaelin, W G; Linehan, W M; Klausner, R D; Gnarra, J R; Vande Woude, G F

    1999-09-01

    Loss of function in the von Hippel-Lindau (VHL) tumor suppressor gene occurs in familial and most sporadic renal cell carcinomas (RCCs). VHL has been linked to the regulation of cell cycle cessation (G(0)) and to control of expression of various mRNAs such as for vascular endothelial growth factor. RCC cells express the Met receptor tyrosine kinase, and Met mediates invasion and branching morphogenesis in many cell types in response to hepatocyte growth factor/scatter factor (HGF/SF). We examined the HGF/SF responsiveness of RCC cells containing endogenous mutated (mut) forms of the VHL protein (VHL-negative RCC) with that of isogenic cells expressing exogenous wild-type (wt) VHL (VHL-positive RCC). We found that VHL-negative 786-0 and UOK-101 RCC cells were highly invasive through growth factor-reduced (GFR) Matrigel-coated filters and exhibited an extensive branching morphogenesis phenotype in response to HGF/SF in the three-dimensional (3D) GFR Matrigel cultures. In contrast, the phenotypes of A498 VHL-negative RCC cells were weaker, and isogenic RCC cells ectopically expressing wt VHL did not respond at all. We found that all VHL-negative RCC cells expressed reduced levels of tissue inhibitor of metalloproteinase 2 (TIMP-2) relative to the wt VHL-positive cells, implicating VHL in the regulation of this molecule. However, consistent with the more invasive phenotype of the 786-0 and UOK-101 VHL-negative RCC cells, the levels of TIMP-1 and TIMP-2 were reduced and levels of the matrix metalloproteinases 2 and 9 were elevated compared to the noninvasive VHL-positive RCC cells. Moreover, recombinant TIMPs completely blocked HGF/SF-mediated branching morphogenesis, while neutralizing antibodies to the TIMPs stimulated HGF/SF-mediated invasion in vitro. Thus, the loss of the VHL tumor suppressor gene is central to changes that control tissue invasiveness, and a more invasive phenotype requires additional genetic changes seen in some but not all RCC lines. These

  8. Genetic and Epigenetic Tumor Suppressor Gene Silencing are Distinct Molecular Phenotypes Driven by Growth Promoting Mutations in Non small Cell Lung Cancer

    International Nuclear Information System (INIS)

    Marsit, C. J.; Kelsey, K. T.; Houseman, E. A.; Kelsey, K. T.; Houseman, E. A.; Nelson, H. H.

    2008-01-01

    Both genetic and epigenetic alterations characterize human non small cell lung cancer (NSCLC), but the biological processes that create or select these alterations remain incompletely investigated. Our hypothesis posits that a roughly reciprocal relationship between the propensity for promoter hyper methylation and a propensity for genetic deletion leads to distinct molecular phenotypes of lung cancer. To test this hypothesis, we examined promoter hyper methylation of 17 tumor suppressor genes, as a marker of epigenetic alteration propensity, and deletion events at the 3p21 region, as a marker of genetic alteration. To model the complex biology between these somatic alterations, we utilized an item response theory model. We demonstrated that tumors exhibiting LOH at greater than 30% of informative alleles in the 3p21 region have a significantly reduced propensity for hyper methylation. At the same time, tumors with activating KRAS mutations showed a significantly increased propensity for hyper methylation of the loci examined, a result similar to what has been observed in colon cancer. These data suggest that NSCLCs have distinct epigenetic or genetic alteration phenotypes acting upon tumor suppressor genes and that mutation of oncogenic growth promoting genes, such as KRAS, is associated with the epigenetic phenotype.

  9. Inhibition of adipose triglyceride lipase (ATGL) by the putative tumor suppressor G0S2 or a small molecule inhibitor attenuates the growth of cancer cells.

    Science.gov (United States)

    Zagani, Rachid; El-Assaad, Wissal; Gamache, Isabelle; Teodoro, Jose G

    2015-09-29

    The G0/G1 switch gene 2 (G0S2) is methylated and silenced in a wide range of human cancers. The protein encoded by G0S2 is an endogenous inhibitor of lipid catabolism that directly binds adipose triglyceride lipase (ATGL). ATGL is the rate-limiting step in triglyceride metabolism. Although the G0S2 gene is silenced in cancer, the impact of ATGL in the growth and survival of cancer cells has never been addressed. Here we show that ectopic expression of G0S2 in non-small cell lung carcinomas (NSCL) inhibits triglyceride catabolism and results in lower cell growth. Similarly, knockdown of ATGL increased triglyceride levels, attenuated cell growth and promoted apoptosis. Conversely, knockdown of endogenous G0S2 enhanced the growth and invasiveness of cancer cells. G0S2 is strongly induced in acute promyelocytic leukemia (APL) cells in response to all trans retinoic acid (ATRA) and we show that inhibition of ATGL in these cells by G0S2 is required for efficacy of ATRA treatment. Our data uncover a novel tumor suppressor mechanism by which G0S2 directly inhibits activity of a key intracellular lipase. Our results suggest that elevated ATGL activity may be a general property of many cancer types and potentially represents a novel target for chemotherapy.

  10. Primary microcephaly gene MCPH1 shows signatures of tumor suppressors and is regulated by miR-27a in oral squamous cell carcinoma.

    Directory of Open Access Journals (Sweden)

    Thejaswini Venkatesh

    Full Text Available Mutations in the MCPH1 (microcephalin 1 gene, located at chromosome 8p23.1, result in two autosomal recessive disorders: primary microcephaly and premature chromosome condensation syndrome. MCPH1 has also been shown to be downregulated in breast, prostate and ovarian cancers, and mutated in 1/10 breast and 5/41 endometrial tumors, suggesting that it could also function as a tumor suppressor (TS gene. To test the possibility of MCPH1 as a TS gene, we first performed LOH study in a panel of 81 matched normal oral tissues and oral squamous cell carcinoma (OSCC samples, and observed that 14/71 (19.72% informative samples showed LOH, a hallmark of TS genes. Three protein truncating mutations were identified in 1/15 OSCC samples and 2/5 cancer cell lines. MCPH1 was downregulated at both the transcript and protein levels in 21/41 (51.22% and 19/25 (76% OSCC samples respectively. A low level of MCPH1 promoter methylation was also observed in 4/40 (10% tumor samples. We further observed that overexpression of MCPH1 decreased cellular proliferation, anchorage-independent growth in soft agar, cell invasion and tumor size in nude mice, indicating its tumor suppressive function. Using bioinformatic approaches and luciferase assay, we showed that the 3'-UTR of MCPH1 harbors two non-overlapping functional seed regions for miR-27a which negatively regulated its level. The expression level of miR-27a negatively correlated with the MCPH1 protein level in OSCC. Our study indicates for the first time that, in addition to its role in brain development, MCPH1 also functions as a tumor suppressor gene and is regulated by miR-27a.

  11. The oncogenic transcription factor ERG represses the transcription of the tumour suppressor gene PTEN in prostate cancer cells.

    Science.gov (United States)

    Adamo, Patricia; Porazinski, Sean; Rajatileka, Shavanthi; Jumbe, Samantha; Hagen, Rachel; Cheung, Man-Kim; Wilson, Ian; Ladomery, Michael R

    2017-11-01

    The oncogene ETS-related gene (ERG) encodes a transcription factor with roles in the regulation of haematopoiesis, angiogenesis, vasculogenesis, inflammation, migration and invasion. The ERG oncogene is activated in >50% of prostate cancer cases, generally through a gene fusion with the androgen-responsive promoter of transmembrane protease serine 2. Phosphatase and tensin homologue ( PTEN ) is an important tumour suppressor gene that is often inactivated in cancer. ERG overexpression combined with PTEN inactivation or loss is often associated with aggressive prostate cancer. The present study aimed to determine whether or not ERG regulates PTEN transcription directly. ERG was demonstrated to bind to the PTEN promoter and repress its transcription. ERG overexpression reduced endogenous PTEN expression, whereas ERG knockdown increased PTEN expression. The ability of ERG to repress PTEN may contribute to a more cancer-permissive environment.

  12. Active suppression of host-vs-graft reaction in pregnant mice. VII. Spontaneous abortion of allogeneic CBA/J x DBA/2 fetuses in the uterus of CBA/J mice correlates with deficient non-T suppressor cell activity

    International Nuclear Information System (INIS)

    Clark, D.A.; Chaput, A.; Tutton, D.

    1986-01-01

    The mammalian fetus has been viewed as an unusually successful type of allograft and unexplained spontaneous abortion as a possible example of maternal rejection. Previous studies have shown the presence of small lymphocytic suppressor cells in the murine decidua which block the generation and reactivation of anti-paternal cytotoxic T lymphocytes (CTL) and lymphokine-activated killer cells (LAK) by elaborating a factor that inhibits the response to interleukin 2 (IL 2). A deficiency of these suppressor cells was associated with implants of xenogeneic Mus caroli embryos in the Mus musculus uterus which are infiltrated by maternal lymphoid cells and aborted. A deficiency of such suppressor cells in the lymph nodes draining the uterus of CBA/J females in the process of aborting their semi-allogeneic CBA x DBA/2 F 1 progeny has also been shown. CBA/J females possess significantly lower levels of decidua-associated non-T suppressor cells on day 8.5 to 10.5 of allopregnancy than do mothers that will produce large litters of live babies. The F 1 embryos are infiltrated by maternal lymphocytes prior to abortion, and the infiltration and abortion rate appears to be augmented by pre-immunization with paternal DBA/2 spleen cells. The CBA/J x DBA/2J mating combination provides a model of spontaneous abortion in which immunologic factors play an important role and demonstrates that the association between deficiency of decidua-associated suppressor cells and xenopregnancy failure also holds true for the failure of allopregnancies resulting from natural within-species mating

  13. Pretreatment dietary intake is associated with tumor suppressor DNA methylation in head and neck squamous cell carcinomas

    Science.gov (United States)

    Colacino, Justin A.; Arthur, Anna E.; Dolinoy, Dana C.; Sartor, Maureen A.; Duffy, Sonia A.; Chepeha, Douglas B.; Bradford, Carol R.; Walline, Heather M.; McHugh, Jonathan B.; D'Silva, Nisha; Carey, Thomas E.; Wolf, Gregory T.; Taylor, Jeremy M.G.; Peterson, Karen E.; Rozek, Laura S.

    2012-01-01

    Diet is associated with cancer prognosis, including head and neck cancer (HNC), and has been hypothesized to influence epigenetic state by determining the availability of functional groups involved in the modification of DNA and histone proteins. The goal of this study was to describe the association between pretreatment diet and HNC tumor DNA methylation. Information on usual pretreatment food and nutrient intake was estimated via food frequency questionnaire (FFQ) on 49 HNC cases. Tumor DNA methylation patterns were assessed using the Illumina Goldengate Methylation Cancer Panel. First, a methylation score, the sum of individual hypermethylated tumor suppressor associated CpG sites, was calculated and associated with dietary intake of micronutrients involved in one-carbon metabolism and antioxidant activity, and food groups abundant in these nutrients. Second, gene specific analyses using linear modeling with empirical Bayesian variance estimation were conducted to identify if methylation at individual CpG sites was associated with diet. All models were controlled for age, sex, smoking, alcohol and HPV status. Individuals reporting in the highest quartile of folate, vitamin B12 and vitamin A intake, compared with those in the lowest quartile, showed significantly less tumor suppressor gene methylation, as did patients reporting the highest cruciferous vegetable intake. Gene specific analyses identified differential associations between DNA methylation and vitamin B12 and vitamin A intake when stratifying by HPV status. These preliminary results suggest that intake of folate, vitamin A and vitamin B12 may be associated with the tumor DNA methylation profile in HNC and enhance tumor suppression. PMID:22722388

  14. The Human Homolog of Drosophila Headcase Acts as a Tumor Suppressor through Its Blocking Effect on the Cell Cycle in Hepatocellular Carcinoma.

    Directory of Open Access Journals (Sweden)

    Jun Wang

    Full Text Available The molecular pathogenesis of hepatocellular carcinoma (HCC is heterogeneous and extremely complex. Thus, for individual molecular targeted therapy, novel molecular markers are needed. The abnormal expression of the human homolog of Drosophila headcase (HECA homo has been found in pancreatic, colorectal, and oral squamous cell carcinoma. Studies of oral squamous cell carcinoma have also demonstrated that the HECA homo protein can be negatively controlled by the Wnt-pathway and transcription factor 4 (TCF4 and can slow cell division by interacting with cyclins and CDKs. However, the role of HECA in HCC has not been reported elsewhere. Here, immunohistochemical analysis revealed that the downregulation of HECA homo protein occurred in 71.0% (66/93 of HCC cases and was positively correlated with a poorly differentiated grade, high serum AFP level, liver cirrhosis and large tumor size. The expression of HECA homo was detected in five live cell lines. In vitro, the overexpression of HECA homo in HepG2, Huh-7 and MHCC-97H cells could inhibit cell proliferation and colony formation and induce G1 phase arrest. In contrast, the downregulation of HECA homo could promote cell proliferation, colony formation and the cell cycle process. However, neither the overexpression nor downregulation of HECA homo in the three cell lines could affect cell migration or invasion. Collectively, HECA homo is regularly expressed in normal live cells, and the HECA homo protein level is heterogeneously altered in HCC, but the downregulation of HECA homo is more common and positively correlated with several malignant phenotypes. The HECA homo protein can slow cell proliferation to some extent primarily through its blocking effect on the cell cycle. Hence, the HECA homo protein may act as a tumor suppressor in HCC and might be a potential molecular marker for diagnostic classification and targeted therapy in HCC.

  15. Increased natural CD4+CD25+ regulatory T cells and their suppressor activity do not contribute to mortality in murine polymicrobial sepsis.

    Science.gov (United States)

    Scumpia, Philip O; Delano, Matthew J; Kelly, Kindra M; O'Malley, Kerri A; Efron, Philip A; McAuliffe, Priscilla F; Brusko, Todd; Ungaro, Ricardo; Barker, Tolga; Wynn, James L; Atkinson, Mark A; Reeves, Westley H; Salzler, Michael J Clare; Moldawer, Lyle L

    2006-12-01

    Regulatory T cells (Tregs), including natural CD4+CD25+ Tregs and inducible IL-10 producing T regulatory type 1 (T(R)1) cells, maintain tolerance and inhibit autoimmunity. Recently, increased percentages of Tregs have been observed in the blood of septic patients, and ex vivo-activated Tregs were shown to prevent polymicrobial sepsis mortality. Whether endogenous Tregs contribute to sepsis outcome remains unclear. Polymicrobial sepsis, induced by cecal ligation and puncture, caused an increased number of splenic Tregs compared with sham-treated mice. Splenic CD4+CD25+ T cells from septic mice expressed higher levels of Foxp3 mRNA and were more efficient suppressors of CD4+CD25- T effector cell proliferation. Isolated CD4+ T cells from septic mice displayed increased intracellular IL-10 staining following stimulation, indicating that T(R)1 cells may also be elevated in sepsis. Surprisingly, Ab depletion of total CD4+ or CD4+CD25+ populations did not affect mortality. Furthermore, no difference in survival outcome was found between CD25 or IL-10 null mice and wild-type littermates, indicating that Treg or T(R)1-generated IL-10 are not required for survival. These results demonstrate that, although sepsis causes a relative increase in Treg number and increases their suppressive function, their presence does not contribute significantly to overall survival in this model.

  16. Tumor suppressor FLCN inhibits tumorigenesis of a FLCN-null renal cancer cell line and regulates expression of key molecules in TGF-β signaling

    Directory of Open Access Journals (Sweden)

    Linehan W Marston

    2010-06-01

    Full Text Available Abstract Background Germline mutations in the FLCN gene are responsible for the development of fibrofolliculomas, lung cysts and renal neoplasia in Birt-Hogg-Dube' (BHD syndrome. The encoded protein folliculin (FLCN is conserved across species but contains no classic motifs or domains and its function remains unknown. Somatic mutations or loss of heterozygosity in the remaining wild type copy of the FLCN gene have been found in renal tumors from BHD patients suggesting that FLCN is a classic tumor suppressor gene. Results To examine the tumor suppressor function of FLCN, wild-type or mutant FLCN (H255R was stably expressed in a FLCN-null renal tumor cell line, UOK257, derived from a BHD patient. When these cells were injected into nude mice, tumor development was inversely dependent upon the level of wild-type FLCN expression. We identified genes that were differentially expressed in the cell lines with or without wild-type FLCN, many of which are involved in TGF-β signaling, including TGF-β2 (TGFB2, inhibin β A chain (INHBA, thrombospondin 1 (THBS1, gremlin (GREM1, and SMAD3. In support of the in vitro data, TGFB2, INHBA, THBS1 and SMAD3 expression levels were significantly lower in BHD-associated renal tumors compared with normal kidney tissue. Although receptor mediated SMAD phosphorylation was not affected, basal and maximal TGF-β-induced levels of TGFB2, INHBA and SMAD7 were dramatically reduced in FLCN-null cells compared with FLCN-restored cells. Secreted TGF-β2 and activin A (homo-dimer of INHBA protein levels were also lower in FLCN-null cells compared with FLCN-restored cells. Consistent with a growth suppressive function, activin A (but not TGF-β2 completely suppressed anchorage-independent growth of FLCN-null UOK257 cells. Conclusions Our data demonstrate a role for FLCN in the regulation of key molecules in TGF-β signaling and confirm deregulation of their expression in BHD-associated renal tumors. Thus, deregulation of genes

  17. Genistein inhibits proliferation of colon cancer cells by attenuating a negative effect of epidermal growth factor on tumor suppressor FOXO3 activity

    International Nuclear Information System (INIS)

    Qi, Wentao; Weber, Christopher R; Wasland, Kaarin; Savkovic, Suzana D

    2011-01-01

    Soy consumption is associated with a lower incidence of colon cancer which is believed to be mediated by one of its of components, genistein. Genistein may inhibit cancer progression by inducing apoptosis or inhibiting proliferation, but mechanisms are not well understood. Epidermal growth factor (EGF)-induced proliferation of colon cancer cells plays an important role in colon cancer progression and is mediated by loss of tumor suppressor FOXO3 activity. The aim of this study was to assess if genistein exerts anti-proliferative properties by attenuating the negative effect of EGF on FOXO3 activity. The effect of genistein on proliferation stimulated by EGF-mediated loss of FOXO3 was examined in human colonic cancer HT-29 cells. EGF-induced FOXO3 phosphorylation and translocation were assessed in the presence of genistein. EGF-mediated loss of FOXO3 interactions with p53 (co-immunoprecipitation) and promoter of p27kip1 (ChIP assay) were examined in presence of genistein in cells with mutated p53 (HT-29) and wild type p53 (HCT116). Silencing of p53 determined activity of FOXO3 when it is bound to p53. Genistein inhibited EGF-induced proliferation, while favoring dephosphorylation and nuclear retention of FOXO3 (active state) in colon cancer cells. Upstream of FOXO3, genistein acts via the PI3K/Akt pathway to inhibit EGF-stimulated FOXO3 phosphorylation (i.e. favors active state). Downstream, EGF-induced disassociation of FOXO3 from mutated tumor suppressor p53, but not wild type p53, is inhibited by genistein favoring FOXO3-p53(mut) interactions with the promoter of the cell cycle inhibitor p27kip1 in colon cancer cells. Thus, the FOXO3-p53(mut) complex leads to elevated p27kip1 expression and promotes cell cycle arrest. These novel anti-proliferative mechanisms of genistein suggest a possible role of combining genistein with other chemoreceptive agents for the treatment of colon cancer

  18. MicroRNA-193b-3p acts as a tumor suppressor by targeting the MYB oncogene in T-cell acute lymphoblastic leukemia.

    Science.gov (United States)

    Mets, E; Van der Meulen, J; Van Peer, G; Boice, M; Mestdagh, P; Van de Walle, I; Lammens, T; Goossens, S; De Moerloose, B; Benoit, Y; Van Roy, N; Clappier, E; Poppe, B; Vandesompele, J; Wendel, H-G; Taghon, T; Rondou, P; Soulier, J; Van Vlierberghe, P; Speleman, F

    2015-04-01

    The MYB oncogene is a leucine zipper transcription factor essential for normal and malignant hematopoiesis. In T-cell acute lymphoblastic leukemia (T-ALL), elevated MYB levels can arise directly through T-cell receptor-mediated MYB translocations, genomic MYB duplications or enhanced TAL1 complex binding at the MYB locus or indirectly through the TAL1/miR-223/FBXW7 regulatory axis. In this study, we used an unbiased MYB 3'untranslated region-microRNA (miRNA) library screen and identified 33 putative MYB-targeting miRNAs. Subsequently, transcriptome data from two independent T-ALL cohorts and different subsets of normal T-cells were used to select miRNAs with relevance in the context of normal and malignant T-cell transformation. Hereby, miR-193b-3p was identified as a novel bona fide tumor-suppressor miRNA that targets MYB during malignant T-cell transformation thereby offering an entry point for efficient MYB targeting-oriented therapies for human T-ALL.

  19. Effect of recombinant adenovirus encoding human p53 tumor suppressor gene (rAd-p53) on the growth and radiotherapeutic sensitivity of human lymphoma cell lines

    International Nuclear Information System (INIS)

    Yu Zeyang; Fan Wo; Li Dongqing; Zhu Ran; Wang Yongqing; Wu Jinchang

    2008-01-01

    Objective: To explore the inhibitory effect and radiation sensitization of recombinant adenovirus encoding human p53 tumor suppressor gene (rAd-p53) on human lymphoma cell lines. Methods: Human lymphoma cell lines Raji and Daudi were treated with rAd-p53, radiation therapy and combined treatment, respectively. The cell growth inhibition was assessed by MTT. The p53 protein expression was detected by Western blotting, and p53 mRNA was detected by BT-PCB. Results: The MTT results showed that the inhibitory effect and radiosensitivity enhancement of rAd-p53 on human lymphoma cell lines were not obvious [Raji: (27.5±4.1)%; Daudi: (28.1±1.6)%]. The results of Western blotting and BT-PCB showed that extrinsic p53 protein and p53 mRNA were expressed to some degree, but not at high-level. In addition, the results didn't demonstrate obvious radiosensitivity enhancement. Conclusions: The role of inhibition and radiosensitivity enhancement of rAd-p53 was not significant on human lymphoma cell lines. (authors)

  20. DC-SCRIPT is a novel regulator of the tumor suppressor gene CDKN2B and induces cell cycle arrest in ERα-positive breast cancer cells

    NARCIS (Netherlands)

    M. Ansems (Marleen); J.N. Søndergaard (Jonas Nørskov); A.M. Sieuwerts (Anieta); M.W.G. Looman (Maaike W. G.); M. Smid (Marcel); A.M.A. de Graaf (Annemarie M. A.); V. de Weerd (Vanja); M. Zuidscherwoude (Malou); J.A. Foekens (John); J.W.M. Martens (John); G.J. Adema (Gosse J.)

    2015-01-01

    textabstractBreast cancer is one of the most common causes of cancer-related deaths in women. The estrogen receptor (ERα) is well known for having growth promoting effects in breast cancer. Recently, we have identified DC-SCRIPT (ZNF366) as a co-suppressor of ERα and as a strong and independent

  1. DC-SCRIPT is a novel regulator of the tumor suppressor gene CDKN2B and induces cell cycle arrest in ERalpha-positive breast cancer cells

    NARCIS (Netherlands)

    Ansems, M.; Sondergaard, J.N.; Sieuwerts, A.M.; Looman, M.W.G.; Smid, M.; Graaf, A.M.A. de; Weerd, V. de; Zuidscherwoude, M.; Foekens, J.A.; Martens, J.W.; Adema, G.J.

    2015-01-01

    Breast cancer is one of the most common causes of cancer-related deaths in women. The estrogen receptor (ERalpha) is well known for having growth promoting effects in breast cancer. Recently, we have identified DC-SCRIPT (ZNF366) as a co-suppressor of ERalpha and as a strong and independent

  2. Suppressor of cytokine signaling (SOCS genes are silenced by DNA hypermethylation and histone deacetylation and regulate response to radiotherapy in cervical cancer cells.

    Directory of Open Access Journals (Sweden)

    Moon-Hong Kim

    Full Text Available Suppressor of cytokine signaling (SOCS family is an important negative regulator of cytokine signaling and deregulation of SOCS has been involved in many types of cancer. All cervical cancer cell lines tested showed lower expression of SOCS1, SOCS3, and SOCS5 than normal tissue or cell lines. The immunohistochemistry result for SOCS proteins in human cervical tissue also confirmed that normal tissue expressed higher level of SOCS proteins than neighboring tumor. Similar to the regulation of SOCS in other types of cancer, DNA methylation contributed to SOCS1 downregulation in CaSki, ME-180, and HeLa cells. However, the expression of SOCS3 or SOCS5 was not recovered by the inhibition of DNA methylation. Histone deacetylation may be another regulatory mechanism involved in SOCS1 and SOCS3 expression, however, SOCS5 expression was neither affected by DNA methylation nor histone deacetylation. Ectopic expression of SOCS1 or SOCS3 conferred radioresistance to HeLa cells, which implied SOCS signaling regulates the response to radiation in cervical cancer. In this study, we have shown that SOCS expression repressed by, in part, epigenetically and altered SOCS1 and SOCS3 expression could contribute to the radiosensitive phenotype in cervical cancer.

  3. Stabilization of the prostate-specific tumor suppressor NKX3.1 by the oncogenic protein kinase Pim-1 in prostate cancer cells.

    Science.gov (United States)

    Padmanabhan, Achuth; Gosc, Eliza B; Bieberich, Charles J

    2013-05-01

    Loss of NKX3.1 is an early and consistent event in prostate cancer and is associated with increased proliferation of prostate epithelial cells and poor prognosis. NKX3.1 stability is regulated post-translationally through phosphorylation at multiple sites by several protein kinases. Here, we report the paradoxical stabilization of the prostate-specific tumor suppressor NKX3.1 by the oncogenic protein kinase Pim-1 in prostate cancer cells. Pharmacologic Pim-1 inhibition using the small molecule inhibitor CX-6258 decreased steady state levels and half-life of NKX3.1 protein but mRNA was not affected. This effect was reversed by inhibition of the 26S-proteasome, demonstrating that Pim-1 protects NKX3.1 from proteasome-mediated degradation. Mass spectrometric analyses revealed Thr89, Ser185, Ser186, Ser195, and Ser196 as Pim-1 phospho-acceptor sites on NKX3.1. Through mutational analysis, we determined that NKX3.1 phosphorylation at Ser185, Ser186, and within the N-terminal PEST domain is essential for Pim-1-mediated stabilization. Further, we also identified Lys182 as a critical residue for NKX3.1 stabilization by Pim-1. Pim-1-mediated NKX3.1 stabilization may be important in maintaining normal cellular homeostasis in normal prostate epithelial cells, and may maintain basal NKX3.1 protein levels in prostate cancer cells. Copyright © 2012 Wiley Periodicals, Inc.

  4. Sulforaphane Reverses the Expression of Various Tumor Suppressor Genes by Targeting DNMT3B and HDAC1 in Human Cervical Cancer Cells

    Directory of Open Access Journals (Sweden)

    Munawwar Ali Khan

    2015-01-01

    Full Text Available Sulforaphane (SFN may hinder carcinogenesis by altering epigenetic events in the cells; however, its molecular mechanisms are unclear. The present study investigates the role of SFN in modifying epigenetic events in human cervical cancer cells, HeLa. HeLa cells were treated with SFN (2.5 µM for a period of 0, 24, 48, and 72 hours for all experiments. After treatment, expressions of DNMT3B, HDAC1, RARβ, CDH1, DAPK1, and GSTP1 were studied using RT-PCR while promoter DNA methylation of tumor suppressor genes (TSGs was studied using MS-PCR. Inhibition assays of DNA methyl transferases (DNMTs and histone deacetylases (HDACs were performed at varying time points. Molecular modeling and docking studies were performed to explore the possible interaction of SFN with HDAC1 and DNMT3B. Time-dependent exposure to SFN decreases the expression of DNMT3B and HDAC1 and significantly reduces the enzymatic activity of DNMTs and HDACs. Molecular modeling data suggests that SFN may interact directly with DNMT3B and HDAC1 which may explain the inhibitory action of SFN. Interestingly, time-dependent reactivation of the studied TSGs via reversal of methylation in SFN treated cells correlates well with its impact on the epigenetic alterations accumulated during cancer development. Thus, SFN may have significant implications for epigenetic based therapy.

  5. Immunometabolism and PI(3)K Signaling As a Link between IL-2, Foxp3 Expression, and Suppressor Function in Regulatory T Cells.

    Science.gov (United States)

    Fan, Martin Y; Turka, Laurence A

    2018-01-01

    CD4 + Foxp3 + regulatory T cells (Tregs) are an essential component of immune homeostasis. Modulation of Treg function has been proposed as a means of treating autoimmune conditions and preventing rejection of organ transplants, although achieving this goal will require a detailed understanding of Treg signaling pathways. Signaling within Tregs is known to differ considerably from that observed in other T cell subsets. Of note, Tregs are the only cell type known to constitutively express CD25, the main ligand-binding subunit of the IL-2 receptor. The PI(3)K/Akt/mTOR cascade constitutes a major signaling pathway downstream of IL-2 and is closely tied to cellular metabolism. Due to increasing recognition of the links between cellular fuel usage and immune cell function, the interplay between IL-2 signaling and Treg metabolism represents an important space for exploration and a potential approach for immunomodulation. Here, we discuss how IL-2 may affect Treg metabolism via PI(3)K signaling, as well as the effects of altered metabolism on Treg lineage stability and suppressor function.

  6. Immunometabolism and PI(3K Signaling As a Link between IL-2, Foxp3 Expression, and Suppressor Function in Regulatory T Cells

    Directory of Open Access Journals (Sweden)

    Martin Y. Fan

    2018-01-01

    Full Text Available CD4+ Foxp3+ regulatory T cells (Tregs are an essential component of immune homeostasis. Modulation of Treg function has been proposed as a means of treating autoimmune conditions and preventing rejection of organ transplants, although achieving this goal will require a detailed understanding of Treg signaling pathways. Signaling within Tregs is known to differ considerably from that observed in other T cell subsets. Of note, Tregs are the only cell type known to constitutively express CD25, the main ligand-binding subunit of the IL-2 receptor. The PI(3K/Akt/mTOR cascade constitutes a major signaling pathway downstream of IL-2 and is closely tied to cellular metabolism. Due to increasing recognition of the links between cellular fuel usage and immune cell function, the interplay between IL-2 signaling and Treg metabolism represents an important space for exploration and a potential approach for immunomodulation. Here, we discuss how IL-2 may affect Treg metabolism via PI(3K signaling, as well as the effects of altered metabolism on Treg lineage stability and suppressor function.

  7. The tumor suppressor CDX2 opposes pro-metastatic biomechanical modifications of colon cancer cells through organization of the actin cytoskeleton.

    Science.gov (United States)

    Platet, Nadine; Hinkel, Isabelle; Richert, Ludovic; Murdamoothoo, Devadarssen; Moufok-Sadoun, Ahlam; Vanier, Marie; Lavalle, Philippe; Gaiddon, Christian; Vautier, Dominique; Freund, Jean-Noel; Gross, Isabelle

    2017-02-01

    The vast majority of cancer deaths are caused by the formation of metastases rather than the primary tumor itself. Despite this clinical importance, the molecular and cellular events that support the dissemination of cancer cells are not yet fully unraveled. We have previously shown that CDX2, a homeotic transcription factor essential for gut development, acts as a colon-specific tumor suppressor and opposes metastasis. Here, using a combination of biochemical, biophysical, and immunofluorescence techniques, we further investigated the mechanisms promoted by CDX2 that might antagonize tumor cell dissemination. We found that CDX2 expression regulates the transcription of RHO GEFs, thereby activating RHO signaling cascades that lead to reorganization of the actin cytoskeleton and enhanced adherent junctions. Accordingly, we observed by atomic force microscopy (AFM) that colon cancer cells expressing CDX2 are less deformable, a feature that has been shown to correlate with poor metastatic potential. Thus, this study illustrates how the loss of expression of a transcription factor during colon cancer progression modifies the biomechanical characteristics of tumor cells and hence facilitates invasion and metastasis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  8. Re-expression of methylation-induced tumor suppressor gene silencing is associated with the state of histone modification in gastric cancer cell lines.

    Science.gov (United States)

    Meng, Chun-Feng; Zhu, Xin-Jiang; Peng, Guo; Dai, Dong-Qiu

    2007-12-14

    To identify the relationship between DNA hyper-methylation and histone modification at a hyperme-thylated, silenced tumor suppressor gene promoter in human gastric cancer cell lines and to elucidate whether alteration of DNA methylation could affect histone modification. We used chromatin immunoprecipitation (ChIP) assay to assess the status of histone acetylation and methylation in promoter regions of the p16 and mutL homolog 1 (MLH1) genes in 2 gastric cancer cell lines, SGC-7901 and MGC-803. We used methylation-specific PCR (MSP) to evaluate the effect of 5-Aza-2'-deoxycytidine (5-Aza-dC), trichostatin A (TSA) or their combination treatment on DNA methylation status. We used RT-PCR to determine whether alterations of histone modification status after 5-Aza-dC and TSA treatment are reflected in gene expression. For the p16 and MLH1 genes in two cell lines, silenced loci associated with DNA hypermethylation were characterized by histone H3-K9 hypoacetylation and hypermethylation and histone H3-K4 hypomethylation. Treatment with TSA resulted in moderately increased histone H3-K9 acetylation at the silenced loci with no effect on histone H3-K9 methylation and minimal effects on gene expression. In contrast, treatment with 5-Aza-dC rapidly reduced histone H3-K9 methylation at the silenced loci and resulted in reactivation of the two genes. Combined treatment with 5-Aza-dC and TSA was synergistic in reactivating gene expression at the loci showing DNA hypermethylation. Similarly, histone H3-K4 methylation was not affected after TSA treatment, and increased moderately at the silenced loci after 5-Aza-dC treatment. Hypermethylation of DNA in promoter CpG islands is related to transcriptional silencing of tumor suppressor genes. Histone H3-K9 methylation in different regions of the promoters studied correlates with DNA methylation status of each gene in gastric cancer cells. However, histone H3-K9 acetylation and H3-K4 methylation inversely correlate with DNA methylation

  9. The helper and suppressor functions of primate T cells elicited by a 185K streptococcal antigen, as compared with the helper function elicited by a 4K streptococcal antigen.

    Science.gov (United States)

    Lehner, T; Mehlert, A; Avery, J; Jones, T; Caldwell, J

    1985-08-01

    Helper and suppressor functions of human T lymphocytes that act on antibody-forming B cells were elicited by a large 185K streptococcal cell wall antigen. However, a small 4K streptococcal peptide elicited helper but no suppressor function. These differences in the functional activities of the large and small m.w. streptococcal antigens (SA) were confirmed by direct immunisation of rhesus monkeys with the 185K-SA and 4K-SA. Sequential studies have shown that whereas the 185K-SA elicits dose-dependent helper and suppressor activities, the 4K-SA elicits only helper function. Cell-depletion studies with human cells suggest that removal of T8+ cells by killing with OK.T8 and complement leads to a loss of suppressor and a broadening in the concentration of 185K-SA, which elicits helper activity. Because the 4K-SA does not elicit suppression, removal of T8+ cells does not affect this function. However, similar depletion of T4+ cells results in loss of the helper activities, both with the 185K-SA and 4K-SA, and again a broadening in the concentration of the 185K-SA, which elicits suppression. Direct comparison by autoradiography between 125I-labeled 185K-SA and 4K-SA suggests that both antigens can bind directly to monocytes or T8+ VV+ cells. Furthermore, both antigens can induce helper function if T4+ cells are reconstituted with either monocytes or T8+ VV+ cells. Attempts will now be made to sequence the amino acid determinants of the 185K-SA, so as to define the epitopes responsible for the two major regulating functions elicited by this antigen.

  10. WISP-2 in human gastric cancer and its potential metastatic suppressor role in gastric cancer cells mediated by JNK and PLC-γ pathways.

    Science.gov (United States)

    Ji, Jiafu; Jia, Shuqin; Jia, Yongning; Ji, Ke; Hargest, Rachel; Jiang, Wen G

    2015-09-15

    It has recently been shown that WISP proteins (Wnt-inducted secreted proteins), a group of intra- and extra-cellular regulatory proteins, have been implicated in the initiation and progression of a variety of tumour types including colorectal and breast cancer. However, the role of WISP proteins in gastric cancer (GC) cells and their clinical implications have not yet been elucidated. The expression of WISP molecules in a cohort of GC patients was analysed using real-time quantitative PCR and immunohistochemistry. The expression of a panel of recognised epithelial-mesenchymal transition (EMT) markers was quantified using Q-PCR in paired tumour and normal tissues. WISP-2 knockdown (kd) sublines using ribozyme transgenes were created in the GC cell lines AGS and HGC27. Subsequently, several biological functions, including cell growth, adhesion, migration and invasion, were studied. Potential pathways for the interaction of EMT, extracellular matrix and MMP were evaluated. Overexpression of WISP-2 was detected in GC and significantly correlated with early tumour node-metastasis staging, differentiation status and positively correlated with overall survival and disease-free survival of the patients. WISP-2 expression was inversely correlated with that of Twist and Slug in paired samples. Kd of WISP-2 expression promoted the proliferation, migration and invasion of GC cells. WISP-2 suppressed GC cell metastasis through reversing EMT and suppressing the expression and activity of MMP9 and MMP2 via JNK and ERK. Cell motility analysis indicated that WISP-2 kd contributed to GC cells' motility and can be attenuated by PLC-γ and JNK small inhibitors. Increased expression of WISP-2 in GC is positively correlated with favourable clinical features and the survival of patients with GC and is a negative regulator of growth, migration and invasion in GC cells. These findings suggest that WISP-2 is a potential tumour suppressor in GC.

  11. Tumoral tissue specific promoter hypermethylation of distinct tumor suppressor genes in a case with non--small cell lung carcinoma: A case report

    Directory of Open Access Journals (Sweden)

    Arslan Sulhattin

    2008-01-01

    Full Text Available Objective: Non-small cell lung carcinoma is an aggressive phenomenon and the epigenetical alterations of some tumor supressor genes have been reported for the different tumor types. Case Presentation: It is presented a case report concerning a 43 years old male with NSCLC on the lower segment of the right lung. The patient underwent a diag-nostic excisional thin-needle biopsy and after the histological confirmation. We examined the promoter methylation status of some distinct tumor supressor genes in tumoral and blood tissues of the case after sodium bisulfite conversion and DNA amplification with methylation specific multiplex PCR technique. Both tissues were also searched for G to A transitions in codons 12 and 13 of the K-ras proto-oncogene. Results: Tumor specimen showed fully methyl pattern profiles for the SFRP2, p16, DAPK1 and partially hyper-methylated profile for the p53 and MGMT genes in this case with non-small lung carci-noma. Blood speicemen showed normal hypomethylated profiles for all studied TS genes. The K-ras proto-oncogene was in normal structure both in blood and tumoral spiecemens that examined. Conclusion: Results indicate that genes exhibit tumor suppressor activi-ties in blood, but exhibit epigenetic inactivation in carcinoma cell. These findings strongly support the hypothesis that epigenetic mechanisms may play an important role in the non-small cell lung carcinogenesis in human.

  12. Intrinsic tolerance in autologous collagen-induced arthritis is generated by CD152-dependent CD4+ suppressor cells

    DEFF Research Database (Denmark)

    Treschow, Alexandra P; Bäcklund, Johan; Holmdahl, Rikard

    2005-01-01

    . We found that expression of heterologous rat CII sequence in the cartilage of mice positively selects autoreactive CD4(+) T cells with suppressive capacity. Although CD4(+)CD25(+) cells did not play a prominent role in this suppression, CD152-expressing T cells played a crucial role in this tolerance....... MMC CD4(+) T cells were able to suppress proliferation of wild-type cells in vitro where this suppression required cell-to-cell contact. The suppressive capability of MMC cells was also demonstrated in vivo, as transfer of such cells into wild-type arthritis susceptible mice delayed arthritis onset....... This study also determined that both tolerance and disease resistance were CD152-dependent as demonstrated by Ab treatment experiments. These findings could have relevance for RA because the transgenic mice used express the same CII epitope in cartilage as humans and because autoreactive T cells, specific...

  13. [Effects of moxibustion intervention on inflammatory reactions and expression of suppressor of cytokine signaling proteins of synovium cells in rheumatoid arthritis rabbits].

    Science.gov (United States)

    Yang, Xin; Liu, Xu-Guang; Wang, Yue; Yang, Shen-Qiao; Jin, Rong-Jiang

    2013-04-01

    To observe the effect of moxibustion intervention on inflammatory reactions and expression of suppressor of cyfokine signaling 1 (SOCS 1) and SOCS 2 [Which are involved in inhibition of the Janus Kinase-signal transducer and activator of transcrip-tion (JAK/STAT signaling pathway and in sffenuation of cytokine signaling)] in synovium cells of the hind-knee joint in rheumatoid arthritis (RA) rabbits, so as to study its mechanism underlying improvement of RA. Forty-two Japanese big-ear white rabbits were randomized into control, model and moxibustion groups respectively, with 14 cases in each group. RA model was established by injection of Freund's Complete Adjuvant (0. 5 mL/kg) into the rabbits' bilateral hind-knee joint cavities. Moxibustion was applied to bilateral "Shenshu" (BL 23) areas, 5 cones every time, once daily for 3 weeks except the Sundays. The perimeters of rabbits' hind legs were measured before and after modeling and after the therapy. The synovial tissue of joint was sampled for analyzing the expression levels of SOCS 1 and SOCS 3 by immunohistochemistry. Before the therapy, the perimeters of bilateral knee joints of the control, model and moxibustion groups were of no statistical significance (P>0. 05). In comparison with the control group, the perimeters of bilateral knee joints were significantly increased on day 1, 7, 14 and 21 in the model group (P<0. 01). Compared with the model group, the perimeters of bilateral knee joints in the moxibustion group were significantly decreased (P<0. 05), suggesting an improvement of the inflammatory reaction after moxibustion intervention. Correspondingly, synovial SOCS 1 and SOCS 3 expression levels were remarkabely higher in the model group than in the control group (P<0. 01), and obviously decreased in the moxibustion group compared with the model group (P<0. 01). Moxibustion intervention has an anti-inflammatory and detumescent effects in RA rabbits, which may be closely associated with its effects in

  14. Loss of a putative tumor suppressor locus after gamma-ray-induced neoplastic transformation of HeLa x Skin fibroblast human cell hybrids

    International Nuclear Information System (INIS)

    Mendonca, M.S.; Redpath, J.L.; Fasching, C.L.

    1995-01-01

    The nontumorigenic HeLa x skin fibroblast hybrid cell line, CGL1, can be induced to re-express HeLa tumor-associated cell surface antigen, p75-IAP (intestinal alkaline phosphatase), with resulting neoplastic transformation, by exposure to γ radiation. This has allowed the human hybrid system to be developed into a quantitative in vitro model for radiation-induced neoplastic transformation of human cells. Recently, several γ-ray-induced IAP-expression mutants (GIMs) of the nontumorigenic HeLa x skin fibroblast hybrid CGL1 were isolated and all were tumorigenic when injected subcutaneously into nude mice. Control cell lines which were negative for p75-IAP (CONs) were also isolated from irradiated populations, and none were found to be tumorigenic. We have now begun to investigate the molecular basis of radiation-induced neoplastic transformation in this system by studying the potential genetic linkage between p75/IAP expression, tumorigenicity and damage to a putative tumor suppressor locus on fibroblast chromosome 11. Previous analysis of rare spontaneous segregants has indicated that this locus is involved in the regulation of tumorigenicity and in the expression of the HeLa tumor-associated cell surface marker intestinal alkaline phosphatase (p75-IAP) in this system. Therefore, analysis by restriction fragment length polymorphism and chromosome painting have been performed for chromosome 11, and for chromosome 13 as a control, for the p75/IAP-positive GIM and p75/IAP-negative CON cell lines. We report that in five of eight of the GIMs large-scale damage to the fibroblast chromosome 11's is evident (four GIMs have lost one complete copy of a fibroblast chromosome 11 heavily damaged). None of the CONs, however (0/5), have lost a complete copy of either fibroblast chromosome 11. No large-scale damage to the control chromosome 13's was detected in the GIMs or CONs. 49 refs., 3 figs., 2 tabs

  15. ELF5 Drives Lung Metastasis in Luminal Breast Cancer through Recruitment of Gr1+ CD11b+ Myeloid-Derived Suppressor Cells.

    Directory of Open Access Journals (Sweden)

    David Gallego-Ortega

    2015-12-01

    Full Text Available During pregnancy, the ETS transcription factor ELF5 establishes the milk-secreting alveolar cell lineage by driving a cell fate decision of the mammary luminal progenitor cell. In breast cancer, ELF5 is a key transcriptional determinant of tumor subtype and has been implicated in the development of insensitivity to anti-estrogen therapy. In the mouse mammary tumor virus-Polyoma Middle T (MMTV-PyMT model of luminal breast cancer, induction of ELF5 levels increased leukocyte infiltration, angiogenesis, and blood vessel permeability in primary tumors and greatly increased the size and number of lung metastasis. Myeloid-derived suppressor cells, a group of immature neutrophils recently identified as mediators of vasculogenesis and metastasis, were recruited to the tumor in response to ELF5. Depletion of these cells using specific Ly6G antibodies prevented ELF5 from driving vasculogenesis and metastasis. Expression signatures in luminal A breast cancers indicated that increased myeloid cell invasion and inflammation were correlated with ELF5 expression, and increased ELF5 immunohistochemical staining predicted much shorter metastasis-free and overall survival of luminal A patients, defining a group who experienced unexpectedly early disease progression. Thus, in the MMTV-PyMT mouse mammary model, increased ELF5 levels drive metastasis by co-opting the innate immune system. As ELF5 has been previously implicated in the development of antiestrogen resistance, this finding implicates ELF5 as a defining factor in the acquisition of the key aspects of the lethal phenotype in luminal A breast cancer.

  16. The putative tumor suppressor microRNA-497 modulates gastric cancer cell proliferation and invasion by repressing eIF4E

    Energy Technology Data Exchange (ETDEWEB)

    Li, Weidong; Jin, Xuejun; Deng, Xubin [Department of Medical Oncology, Affiliated Cancer Hospital of Guangzhou Medical University, Cancer Center of Guangzhou Medical University (CCGMU), Guangzhou (China); Zhang, Gong [Department of Radiotherapy, People’s Hospital of Shanxi Province, Taiyuan (China); Zhang, Bingqian [Cancer Research Institution, Southern Medical University, Guangzhou (China); Ma, Lei, E-mail: malei01@yeah.net [Department of Medical Oncology, Affiliated Cancer Hospital of Guangzhou Medical University, Cancer Center of Guangzhou Medical University (CCGMU), Guangzhou (China)

    2014-06-27

    Highlights: • MiR-497 expression was down-regulated in GC patients and GC cell lines. • MiR-497 inhibited cell proliferation and invasion of GC cells in vitro. • MiR-497 modulated eIF4E expression in GC cells. • Restoration of miR-497 decreased tumor growth and metastasis in vivo. - Abstract: Accumulating evidence has shown that microRNAs are involved in multiple processes in gastric cancer (GC) development and progression. Aberrant expression of miR-497 has been frequently reported in cancer studies; however, the role and mechanism of its function in GC remains unknown. Here, we reported that miR-497 was frequently downregulated in GC tissues and associated with aggressive clinicopathological features of GC patients. Further in vitro observations showed that the enforced expression of miR-497 inhibited cell proliferation by blocking the G1/S transition and decreased the invasion of GC cells, implying that miR-497 functions as a tumor suppressor in the progression of GC. In vivo study indicated that restoration of miR-497 inhibited tumor growth and metastasis. Luciferase assays revealed that miR-497 inhibited eIF4E expression by targeting the binding sites in the 3′-untranslated region of eIF4E mRNA. qRT-PCR and Western blot assays verified that miR-497 reduced eIF4E expression at both the mRNA and protein levels. A reverse correlation between miR-497 and eIF4E expression was noted in GC tissues. Taken together, our results identify a crucial tumor suppressive role of miR-497 in the progression of GC and suggest that miR-497 might be an anticancer therapeutic target for GC patients.

  17. Tumor suppressors BTG1 and IKZF1 cooperate during mouse leukemia development and increase relapse risk in B-cell precursor acute lymphoblastic leukemia patients.

    Science.gov (United States)

    Scheijen, Blanca; Boer, Judith M; Marke, René; Tijchon, Esther; van Ingen Schenau, Dorette; Waanders, Esmé; van Emst, Liesbeth; van der Meer, Laurens T; Pieters, Rob; Escherich, Gabriele; Horstmann, Martin A; Sonneveld, Edwin; Venn, Nicola; Sutton, Rosemary; Dalla-Pozza, Luciano; Kuiper, Roland P; Hoogerbrugge, Peter M; den Boer, Monique L; van Leeuwen, Frank N

    2017-03-01

    Deletions and mutations affecting lymphoid transcription factor IKZF1 (IKAROS) are associated with an increased relapse risk and poor outcome in B-cell precursor acute lymphoblastic leukemia. However, additional genetic events may either enhance or negate the effects of IKZF1 deletions on prognosis. In a large discovery cohort of 533 childhood B-cell precursor acute lymphoblastic leukemia patients, we observed that single-copy losses of BTG1 were significantly enriched in IKZF1 -deleted B-cell precursor acute lymphoblastic leukemia ( P =0.007). While BTG1 deletions alone had no impact on prognosis, the combined presence of BTG1 and IKZF1 deletions was associated with a significantly lower 5-year event-free survival ( P =0.0003) and a higher 5-year cumulative incidence of relapse ( P =0.005), when compared with IKZF1 -deleted cases without BTG1 aberrations. In contrast, other copy number losses commonly observed in B-cell precursor acute lymphoblastic leukemia, such as CDKN2A/B, PAX5, EBF1 or RB1 , did not affect the outcome of IKZF1 -deleted acute lymphoblastic leukemia patients. To establish whether the combined loss of IKZF1 and BTG1 function cooperate in leukemogenesis, Btg1 -deficient mice were crossed onto an Ikzf1 heterozygous background. We observed that loss of Btg1 increased the tumor incidence of Ikzf1 +/- mice in a dose-dependent manner. Moreover, murine B cells deficient for Btg1 and Ikzf1 +/- displayed increased resistance to glucocorticoids, but not to other chemotherapeutic drugs. Together, our results identify BTG1 as a tumor suppressor in leukemia that, when deleted, strongly enhances the risk of relapse in IKZF1 -deleted B-cell precursor acute lymphoblastic leukemia, and augments the glucocorticoid resistance phenotype mediated by the loss of IKZF1 function. Copyright© Ferrata Storti Foundation.

  18. Endogenous microRNA-424 predicts clinical outcome and its inhibition acts as cancer suppressor in human non-small cell lung cancer.

    Science.gov (United States)

    Wang, Yu; Lv, Zhenyang; Fu, Junfeng; Wang, Ze; Fan, Zhe; Lei, Ting

    2017-05-01

    We examined the expression, clinical correlation and functional mechanisms of endogenous microRNA-424 (miR-424) in human non-small cell lung cancer (NSCLC). Expression pattern of endogenous miR-424 was examined by qRT-PCR in clinical samples obtained from 233 NSCLC patients. Correlations between differential miR-424 expression level (low vs. high) and NSCLC patients' clinicopathological parameters or survival were statistically examined. In in vitro NSCLC H596 and SW900 cells, miR-424 was either upregulated or downregulation by lentiviral transduction. Their effects on cancer cell viability, proliferation, and cell-cycle transition were also examined. MiR-424 expression was not different between NSCLC tumors and healthy lung tissues. However, it is much upregulated in NSCLC tumors associated with patients at advanced clinical stages. Statistical analyses demonstrated that high endogenous miR-424 expression in NSCLC tumors was significantly correlated with patients' advanced clinical stages, aggressive tumor metastasis, and short survival. In addition, Cox regression model predicted that endogenous miR-424 might be an independent prognostic marker in NSCLC. In in vitro NSCLC cell lines, miR-424 downregulation had a significant suppressing effect on cancer proliferation and G1 to S phase cell-cycle transition. On the other hand, miR-424 upregulation had no effect on NSCLC in vitro. High endogenous miR-424 expression in tumors may predict poor prognosis of patients with NSCLC. Inhibiting endogenous miR-424 may also serve an effective cancer suppressor in NSCLC. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  19. Role of the Ink4a/Arf tumor suppressors in cerebellar development, stem cells and cancer

    OpenAIRE

    Valk-Lingbeek, Merel Esmée

    2005-01-01

    In order to take proper cell fate decisions, cells have to guide their biochemical machinery through the appropriate decisions in both differentiation and proliferation. Especially for stem cells such decisions are critical as they have the capacity to self-renew, i.e. give rise to new daughter stem cells and differentiated progeny. Important to mention here is at least a subset of cancers is now thought of as to derive from cancer stem cells. The current view is that either stem cells aberra...

  20. Role of the Ink4a/Arf tumor suppressors in cerebellar development, stem cells and cancer

    NARCIS (Netherlands)

    Valk-Lingbeek, Merel Esmée

    2005-01-01

    In order to take proper cell fate decisions, cells have to guide their biochemical machinery through the appropriate decisions in both differentiation and proliferation. Especially for stem cells such decisions are critical as they have the capacity to self-renew, i.e. give rise to new daughter stem

  1. The soybean peptide lunasin promotes apoptosis of mammary epithelial cells via induction of tumor suppressor PTEN: similarities and distinct actions from soy isoflavone genistein.

    Science.gov (United States)

    Pabona, John Mark P; Dave, Bhuvanesh; Su, Ying; Montales, Maria Theresa E; de Lumen, Ben O; de Mejia, Elvira G; Rahal, Omar M; Simmen, Rosalia C M

    2013-01-01

    Breast cancer is the leading cause of cancer deaths in women. Diet and lifestyle are major contributing factors to increased breast cancer risk. While mechanisms underlying dietary protection of mammary tumor formation are increasingly elucidated, there remains a dearth of knowledge on the nature and precise actions of specific bioactive components present in foods with purported health effects. The 43-amino acid peptide lunasin (LUN) is found in soybeans, is bioavailable similar to the isoflavone genistein (GEN), and thus may mediate the beneficial effects of soy food consumption. Here, we evaluated whether LUN displays common and distinct actions from those of GEN in non-malignant (mouse HC11) and malignant (human MCF-7) mammary epithelial cells. In MCF-7 cells, LUN up-regulated tumor suppressor phosphatase and tensin homolog deleted in chromosome ten (PTEN) promoter activity, increased PTEN transcript and protein levels and enhanced nuclear PTEN localization, similar to that shown for GEN in mammary epithelial cells. LUN-induced cellular apoptosis, akin to GEN, was mediated by PTEN, but unlike that for GEN, was p53-independent. LUN promoted E-cadherin and β-catenin non-nuclear localization similar to GEN, but unlike GEN, did not influence the proliferative effects of oncogene Wnt1 on HC11 cells. Further, LUN did not recapitulate GEN inhibitory effects on expansion of the cancer stem-like/progenitor population in MCF-7 cells. Results suggest the concerted actions of GEN and LUN on cellular apoptosis for potential mammary tumor preventive effects and highlight whole food consumption rather than intake of specific dietary supplements with limited biological effects for greater health benefits.

  2. Regulation of APC and AXIN2 expression by intestinal tumor suppressor CDX2 in colon cancer cells

    DEFF Research Database (Denmark)

    Olsen, Anders Krüger; Coskun, Mehmet; Bzorek, Michael

    2013-01-01

    Wnt signaling is often constitutively active in colorectal cancer cells. The expression of the intestinal specific transcription factor CDX2 is found to be transiently decreased in invasive cells at the tumor/stroma interface. A recent ChIP-Seq study has indicated that several Wnt signaling...... suggest that a low CDX2 level has influence on the Wnt signaling in invasive colon cancer cells possibly promoting cellular migration....

  3. p16 Tumor Suppressor Gene Methylation in Diffuse Large B Cell Lymphoma: A Study of 88 Cases at Two Hospitals in the East Coast of Malaysia

    Science.gov (United States)

    Mohd Ridah, Lailatul Jalilah; A Talib, Norlelawati; Muhammad, Naznin; Hussain, Faezahtul Arbaeyah; Zainuddin, Norafiza

    2017-10-26

    Introduction: p16 gene plays an important role in the normal cell cycle regulation. Methylation of p16 has been reported to be one of the epigenetic events contributing to the pathogenesis of diffuse large B-cell lymphoma (DLBCL) which occurring at varying frequency. DLBCL is an aggressive and high-grade malignancy which accounts for approximately 30% of all non-Hodgkin lymphoma cases. However, little is known regarding the epigenetic alterations of p16 gene in DLBCL cases in Malaysia. Therefore, the objective of this study was to examine the status of p16 methylation in DLBCL. Methods: A total of 88 formalin-fixed paraffin-embedded DLBCL tissues retrieved from two hospitals located in the east coast of Malaysia, namely Hospital Tengku Ampuan Afzan (HTAA) Pahang and Hospital Universiti Sains Malaysia (HUSM) Kelantan, were chosen for this study. DNA specimens were isolated and subsequently subjected to bisulfite treatment prior to methylation specific-PCR. Two pairs of primers were used to amplify methylated and unmethylated regions of p16 gene. The PCR products were then separated using agarose gel electrophoresis and visualised under UV illumination. SPSS version 12.0 was utilised to perform all statistical analysis. Result: p16 methylation was detected in 65 of 88 (74%) samples. There was a significant association between p16 methylation status and patients aged >50 years old (p=0.04). Conclusion: Our study demonstrated that methylation of p16 tumor suppressor gene in our DLBCL cases is common and significantly increased among patients aged 50 years and above. Aging is known to be an important risk factor in the development of cancers and we speculate that this might be due to the increased transformation of malignant cells in aging cell population. However, this has yet to be confirmed with further research and correlate the findings with clinicopathological parameters. Creative Commons Attribution License

  4. Metformin inhibits epithelial–mesenchymal transition in prostate cancer cells: Involvement of the tumor suppressor miR30a and its target gene SOX4

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jing; Shen, Chengwu [Department of Pharmacy, Shandong Provincial Hospital, Shandong University, Jinan 250021 (China); Wang, Lin [Department of Pathology, School of Medicine, Shandong University, Jinan 250012 (China); Research Center for Medicinal Biotechnology, Shandong Academy of Medicinal Sciences, Jinan 250012 (China); Ma, Quanping [Department of Clinical Laboratory, The Fourth People’s Hospital of Jinan, Jinan 250031 (China); Xia, Pingtian; Qi, Mei; Yang, Muyi [Department of Pathology, School of Medicine, Shandong University, Jinan 250012 (China); Han, Bo, E-mail: boh@sdu.edu.cn [Department of Pathology, School of Medicine, Shandong University, Jinan 250012 (China); Department of Pathology, Qilu Hospital, Shandong University, Jinan 250012 (China)

    2014-09-26

    Highlights: • Metformin inhibits TGF-β-induced EMT in prostate cancer (PCa) cells. • Metformin upregulates tumor suppressor miR30a and downregulates SOX4 in PCa cells. • SOX4 is a target gene of miR30a. - Abstract: Tumor metastasis is the leading cause of mortality and morbidity of prostate cancer (PCa) patients. Epithelial–mesenchymal transition (EMT) plays a critical role in cancer progression and metastasis. Recent evidence suggested that diabetic patients treated with metformin have lower PCa risk and better prognosis. This study was aimed to investigate the effects of metformin on EMT in PCa cells and the possible microRNA (miRNA)-based mechanisms. MiRNAs have been shown to regulate various processes of cancer metastasis. We herein showed that metformin significantly inhibits proliferation of Vcap and PC-3 cells, induces G0/G1 cell cycle arrest and inhibits invasiveness and motility capacity of Vcap cells. Metformin could inhibit TGF-β-induced EMT in Vcap cells, as manifested by inhibition of the increase of N-cadherin (p = 0.013), Vimentin (p = 0.002) and the decrease of E-cadherin (p = 0.0023) and β-catenin (p = 0.034) at mRNA and protein levels. Notably, we demonstrated significant upregulation of miR30a levels by metformin (P < 0.05) and further experiments indicated that miR30a significantly inhibits proliferation and EMT process of Vcap cells. Interestingly, we identified that SOX4, a previously reported oncogenic transcriptional factor and modulator of EMT, is a direct target gene of miR30a. Finally, we screened the expression of miR30a and SOX4 in 84 PCa cases with radical prostatectomy. Of note, SOX4 overexpression is significantly associated with decreased levels of miR30a in PCa cases. In all, our study suggested that inhibition of EMT by metformin in PCa cells may involve upregulation of miR30a and downregulation of SOX4.

  5. Systems analysis of the prostate tumor suppressor NKX3.1 supports roles in DNA repair and luminal cell differentiation [v1; ref status: indexed, http://f1000r.es/35m

    Directory of Open Access Journals (Sweden)

    Chih-Cheng Yang

    2014-05-01

    Full Text Available NKX3.1 is a homeobox transcription factor whose function as a prostate tumor suppressor remains insufficiently understood because neither the transcriptional program governed by NKX3.1, nor its interacting proteins have been fully revealed. Using affinity purification and mass spectrometry, we have established an extensive NKX3.1 interactome which contains the DNA repair proteins Ku70, Ku80, and PARP, thus providing a molecular underpinning to previous reports implicating NKX3.1 in DNA repair. Transcriptomic profiling of NKX3.1-negative prostate epithelial cells acutely expressing NKX3.1 revealed a rapid and complex response that is a near mirror image of the gene expression signature of human prostatic intraepithelial neoplasia (PIN. Pathway and network analyses suggested that NKX3.1 actuates a cellular reprogramming toward luminal cell differentiation characterized by suppression of pro-oncogenic c-MYC and interferon-STAT signaling and activation of tumor suppressor pathways. Consistently, ectopic expression of NKX3.1 conferred a growth arrest depending on TNFα and JNK signaling. We propose that the tumor suppressor function of NKX3.1 entails a transcriptional program that maintains the differentiation state of secretory luminal cells and that disruption of NKX3.1 contributes to prostate tumorigenesis by permitting luminal cell de-differentiation potentially augmented by defects in DNA repair.

  6. Genomic loss of tumor suppressor miRNA-204 promotes cancer cell migration and invasion by activating AKT/mTOR/Rac1 signaling and actin reorganization.

    Directory of Open Access Journals (Sweden)

    J Saadi Imam

    Full Text Available Increasing evidence suggests that chromosomal regions containing microRNAs are functionally important in cancers. Here, we show that genomic loci encoding miR-204 are frequently lost in multiple cancers, including ovarian cancers, pediatric renal tumors, and breast cancers. MiR-204 shows drastically reduced expression in several cancers and acts as a potent tumor suppressor, inhibiting tumor metastasis in vivo when systemically delivered. We demonstrated that miR-204 exerts its function by targeting genes involved in tumorigenesis including brain-derived neurotrophic factor (BDNF, a neurotrophin family member which is known to promote tumor angiogenesis and invasiveness. Analysis of primary tumors shows that increased expression of BDNF or its receptor tropomyosin-related kinase B (TrkB parallel a markedly reduced expression of miR-204. Our results reveal that loss of miR-204 results in BDNF overexpression and subsequent activation of the small GTPase Rac1 and actin reorganization through the AKT/mTOR signaling pathway leading to cancer cell migration and invasion. These results suggest that microdeletion of genomic loci containing miR-204 is directly linked with the deregulation of key oncogenic pathways that provide crucial stimulus for tumor growth and metastasis. Our findings provide a strong rationale for manipulating miR-204 levels therapeutically to suppress tumor metastasis.

  7. [The number of myeloid-derived suppressor cells in the peripheral blood and tumor tissues in patients with gastric cancer and its clinical significance].

    Science.gov (United States)

    Xia, Rui; Wang, Feng; Gao, Tengfei; Wen, Wen; Lu, Binfeng; Zhu, Yibei; Zhang, Xueguang

    2014-07-01

    To investigate the number of myeloid-derived suppressor cells (MDSCs) in peripheral blood, tumor tissue and para-tumor normal tissues in patients with gastric cancer in an attempt to explore the relationship between MDSCs expression and clinicopathologic characteristics. Peripheral blood was collected from 62 gastric cancer patients and 20 healthy volunteers (HC group). Gastric cancer tissues and adjacent normal tissues were obtained from 12 of the 62 gastric cancer patients. HLA-DR⁻ CD33⁺ CD11b⁺ MDSCs were analyzed by flow cytometry. Student's t-test, One-way ANOVA and Mann-Whitney U test were used to explore the correlation between MDSCs expression in peripheral blood and the depth of tumor invasion, degree of differentiation, TNM stage and lymph node metastasis. Compare with the HC group, the number of MDSCs in peripheral blood of newly-diagnosed gastric cancer patients was higher (Pblood of gastric cancer patients was significantly associated with the depth of invasion, degree of differentiation, TNM stage and lymph node metastasis (Ptissues was obviously higher than that of the adjacent tissues in the same patient. The number of MDSCs in peripheral blood from recurrent/metastasis group was obviously higher than that from non-recurrent/metastasis group (Pblood was higher in patients with gastric cancer. MDSCs expression in peripheral blood of gastric cancer patients was closely associated with tumor malignant degree and tumor recurrence/metastasis.

  8. Identification of a genetic interaction between the tumor suppressor EAF2 and the retinoblastoma protein (Rb) signaling pathway in C. elegans and prostate cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Liquan; Wang, Dan [Department of Urology, The University of Pittsburgh, 5200 Centre Avenue, Pittsburgh, PA 15216 (United States); Fisher, Alfred L., E-mail: fishera2@uthscsa.edu [Division of Geriatrics, Gerontology, and Palliative Medicine, Department of Medicine, UTHSCSA, San Antonio, TX 78229 (United States); Center for Healthy Aging, UTHSCSA, San Antonio, TX 78229 (United States); GRECC, STVAHCS, San Antonio, TX 78229 (United States); Wang, Zhou, E-mail: wangz2@upmc.edu [Department of Urology, The University of Pittsburgh, 5200 Centre Avenue, Pittsburgh, PA 15216 (United States); GRECC, STVAHCS, San Antonio, TX 78229 (United States)

    2014-05-02

    Highlights: • RNAi screen identified genetic enhancers for the C. elegans homolog of EAF2. • EAF2 and RBBP4 proteins physically bind to each other and alter transcription. • Overexpression of EAF2 and RBBP4 induces the cell death in prostate cancer cells. - Abstract: The tumor suppressor EAF2 is regulated by androgen signaling and associated with prostate cancer. While EAF2 and its partner ELL have been shown to be members of protein complexes involved in RNA polymerase II transcriptional elongation, the biologic roles for EAF2 especially with regards to the development of cancer remains poorly understood. We have previously identified the eaf-1 gene in Caenorhabditiselegans as the ortholog of EAF2, and shown that eaf-1 interacts with the ELL ortholog ell-1 to control development and fertility in worms. To identify genetic pathways that interact with eaf-1, we screened RNAi libraries consisting of transcription factors, phosphatases, and chromatin-modifying factors to identify genes which enhance the effects of eaf-1(tm3976) on fertility. From this screen, we identified lin-53, hmg-1.2, pha-4, ruvb-2 and set-6 as hits. LIN-53 is the C. elegans ortholog of human retinoblastoma binding protein 4/7 (RBBP 4/7), which binds to the retinoblastoma protein and inhibits the Ras signaling pathway. We find that lin-53 showed a synthetic interaction with eaf-1(tm3976) where knockdown of lin-53 in an eaf-1(tm3976) mutant resulted in sterile worms. This phenotype may be due to cell death as the treated worms contain degenerated embryos with increased expression of the ced-1:GFP cell death marker. Further we find that the interaction between eaf-1 and lin-53/RBBP4/7 also exists in vertebrates, which is reflected by the formation of a protein complex between EAF2 and RBBP4/7. Finally, overexpression of either human EAF2 or RBBP4 in LNCaP cells induced the cell death while knockdown of EAF2 in LNCaP enhanced cell proliferation, indicating an important role of EAF2 in

  9. Analysis of Monocytic and Granulocytic Myeloid-Derived Suppressor Cells Subsets in Patients with Hepatitis C Virus Infection and Their Clinical Significance

    Directory of Open Access Journals (Sweden)

    Gang Ning

    2015-01-01

    Full Text Available Myeloid-derived suppressor cells (MDSCs have been shown to inhibit T-cell responses in many diseases, but, in hepatitis C virus (HCV infected patients, MDSCs are still poorly studied. In this assay, we investigated the phenotype and frequency of two new populations of MDSCs denoted as monocytic and granulocytic MDSCs (M-MDSCs and G-MDSCs in HCV infected patients and analyzed their clinical significance in these patients respectively. We found that the frequency of CD14+HLA-DR-/low cells (M-MDSCs from HCV infected patients (mean ± SE, 3.134% ± 0.340% was significantly increased when compared to healthy controls (mean ± SE, 1.764% ± 0.461% (Z = −2.438, P = 0.015, while there was no statistical difference between the frequency of HLA-DR-/lowCD33+CD11b+CD15+ (G-MDSCs of HCV infected patients and healthy donors (0.201% ± 0.038% versus 0.096% ± 0.026%, P > 0.05, which suggested that HCV infection could cause the proliferation of M-MDSCs instead of G-MDSCs. Besides, we found that the frequency of M-MDSCs in HCV infected patients had certain relevance with age (r = 0.358, P = 0.003; patients older than 40 years old group (mean ± SE, 3.673% ± 0.456% had a significantly higher frequency of M-MDSCs than that of age less than 40 years old group (mean ± SE, 2.363% ± 0.482% (Z = −2.685, P = 0.007. The frequency of M-MDSCs, however, had no correlation with HCV RNA loads, aspartate aminotransferase (AST, alanine aminotransferase (ALT, and the level of liver inflammation degree.

  10. The role of MHC class II antigenic determinants in the function of human antigen binding T8+ cells, monocytes and helper and suppressor factors.

    Science.gov (United States)

    Lehner, T; Jones, T

    1984-06-01

    The role of MHC class II antigens was investigated in the process of antigen binding by T8+ cells and monocytes (Mo) and in the functions of helper factor (HF) and suppressor factor (SF). Monoclonal antibodies (MoAbs) to HLA-DR, DC and SB determinants were used in immunofluorescence, inhibition of antigen binding and affinity chromatography of HF and SF. Indirect immunofluorescence studies suggest that T lymphocytes from peripheral blood of healthy subjects have a small proportion of cells expressing HLA-DR, beta chain determinants (1.4-3.8%). These belong predominantly to the T8+ subset of cells (4.6-8.8%), with only a very small proportion in the T4+ cells (0.1-1.8%). However, DC1 on DRw6+ T cells and SB2,3 on any HLA typed cells were found in significantly greater proportion than the DR antigens in both T8+ and T4+ cells, though this was again greater on T8+ (30 and 25%) than T4+ (8.3 and 14.4%) cells. Although Mo had a greatly increased proportion of cells with DR-beta chain determinants (27-45%) than the T8+ cells, the converse was found with DC1 and SB2,3 determinants (13.9 and 11.4%). Inhibition of 125I-streptococcal antigen (SA) binding to T8+ cells and to Mo by MoAbs to the class II antigens showed that DR-beta chain monomorphic or polymorphic antibodies and DC1 antibodies inhibited binding to both cell types by 66-94%. However, MoAbs to DR-alpha chains or to the SB2,3 determinant failed to yield significant inhibition. Affinity chromatography studies of HF and SF revealed that the DR-beta chain monomorphic and DC1 antibodies bound HF and SF activities and that this was not found with the DR-beta chain polymorphic or SB2,3 antibodies. The results of inhibition of 125I-SA binding to T8+ cells and Mo, and absorption of HF and SF by affinity chromatography with MoAbs suggest four categories of recognition of human MHC class II antigenic determinants. (1) Class II determinants shared by the T8+ cells, Mo, HF and SF and recognized by MoAbs to monomorphic beta

  11. Role of myeloid-derived suppressor cells in amelioration of experimental autoimmune hepatitis following activation of TRPV1 receptors by cannabidiol.

    Directory of Open Access Journals (Sweden)

    Venkatesh L Hegde

    2011-04-01

    Full Text Available Myeloid-derived suppressor cells (MDSCs are getting increased attention as one of the main regulatory cells of the immune system. They are induced at sites of inflammation and can potently suppress T cell functions. In the current study, we demonstrate how activation of TRPV1 vanilloid receptors can trigger MDSCs, which in turn, can inhibit inflammation and hepatitis.Polyclonal activation of T cells, following injection of concanavalin A (ConA, in C57BL/6 mice caused acute hepatitis, characterized by significant increase in aspartate transaminase (AST, induction of inflammatory cytokines, and infiltration of mononuclear cells in the liver, leading to severe liver injury. Administration of cannabidiol (CBD, a natural non-psychoactive cannabinoid, after ConA challenge, inhibited hepatitis in a dose-dependent manner, along with all of the associated inflammation markers. Phenotypic analysis of liver infiltrating cells showed that CBD-mediated suppression of hepatitis was associated with increased induction of arginase-expressing CD11b(+Gr-1(+ MDSCs. Purified CBD-induced MDSCs could effectively suppress T cell proliferation in vitro in arginase-dependent manner. Furthermore, adoptive transfer of purified MDSCs into naïve mice conferred significant protection from ConA-induced hepatitis. CBD failed to induce MDSCs and suppress hepatitis in the livers of vanilloid receptor-deficient mice (TRPV1(-/- thereby suggesting that CBD primarily acted via this receptor to induce MDSCs and suppress hepatitis. While MDSCs induced by CBD in liver consisted of granulocytic and monocytic subsets at a ratio of ∼2∶1, the monocytic MDSCs were more immunosuppressive compared to granulocytic MDSCs. The ability of CBD to induce MDSCs and suppress hepatitis was also demonstrable in Staphylococcal enterotoxin B-induced liver injury.This study demonstrates for the first time that MDSCs play a critical role in attenuating acute inflammation in the liver, and that agents

  12. Role of Myeloid-Derived Suppressor Cells in Amelioration of Experimental Autoimmune Hepatitis Following Activation of TRPV1 Receptors by Cannabidiol

    Science.gov (United States)

    Hegde, Venkatesh L.; Nagarkatti, Prakash S.; Nagarkatti, Mitzi

    2011-01-01

    Background Myeloid-derived suppressor cells (MDSCs) are getting increased attention as one of the main regulatory cells of the immune system. They are induced at sites of inflammation and can potently suppress T cell functions. In the current study, we demonstrate how activation of TRPV1 vanilloid receptors can trigger MDSCs, which in turn, can inhibit inflammation and hepatitis. Methodology/Principal Findings Polyclonal activation of T cells, following injection of concanavalin A (ConA), in C57BL/6 mice caused acute hepatitis, characterized by significant increase in aspartate transaminase (AST), induction of inflammatory cytokines, and infiltration of mononuclear cells in the liver, leading to severe liver injury. Administration of cannabidiol (CBD), a natural non-psychoactive cannabinoid, after ConA challenge, inhibited hepatitis in a dose-dependent manner, along with all of the associated inflammation markers. Phenotypic analysis of liver infiltrating cells showed that CBD-mediated suppression of hepatitis was associated with increased induction of arginase-expressing CD11b+Gr-1+ MDSCs. Purified CBD-induced MDSCs could effectively suppress T cell proliferation in vitro in arginase-dependent manner. Furthermore, adoptive transfer of purified MDSCs into naïve mice conferred significant protection from ConA-induced hepatitis. CBD failed to induce MDSCs and suppress hepatitis in the livers of vanilloid receptor-deficient mice (TRPV1−/−) thereby suggesting that CBD primarily acted via this receptor to induce MDSCs and suppress hepatitis. While MDSCs induced by CBD in liver consisted of granulocytic and monocytic subsets at a ratio of ∼2∶1, the monocytic MDSCs were more immunosuppressive compared to granulocytic MDSCs. The ability of CBD to induce MDSCs and suppress hepatitis was also demonstrable in Staphylococcal enterotoxin B-induced liver injury. Conclusions/Significance This study demonstrates for the first time that MDSCs play a critical role in

  13. Loss of the tumor suppressor spinophilin (PPP1R9B) increases the cancer stem cell population in breast tumors.

    Science.gov (United States)

    Ferrer, I; Verdugo-Sivianes, E M; Castilla, M A; Melendez, R; Marin, J J; Muñoz-Galvan, S; Lopez-Guerra, J L; Vieites, B; Ortiz-Gordillo, M J; De León, J M; Praena-Fernandez, J M; Perez, M; Palacios, J; Carnero, A

    2016-05-01

    The spinophilin (Spn, PPP1R9B) gene is located at 17q21.33, a region frequently associated with microsatellite instability and loss of heterozygosity, especially in breast tumors. Spn is a regulatory subunit of phosphatase1a (PP1), which targets the catalytic subunit to distinct subcellular locations. Spn downregulation reduces PPP1CA activity against the retinoblastoma protein, pRb, thereby maintaining higher levels of phosphorylated pRb. This effect contributes to an increase in the tumorigenic properties of cells in certain contexts. Here, we explored the mechanism of how Spn downregulation contributes to the malignant phenotype and poor prognosis in breast tumors and found an increase in the stemness phenotype. Analysis of human breast tumors showed that Spn mRNA and protein are reduced or lost in 15% of carcinomas, correlating with a worse prognosis, a more aggressive tumor phenotype and triple-negative tumors, whereas luminal tumors showed high Spn levels. Downregulation of Spn by shRNA increased the stemness properties along with the expression of stem-related genes (Sox2, KLF4, Nanog and OCT4), whereas ectopic overexpression of Spn cDNA reduced these properties. Breast tumor stem cells appeared to have low levels of Spn mRNA, and Spn loss correlated with increased stem-like cell appearance in breast tumors as indicated by an increase in CD44+/CD24- cells. A reduction of the levels of PPP1CA mimicked the cancer stem-like cell phenotype of Spn downregulation, suggesting that the mechanism of Spn involves PP1a. These increased cancer stem cell-like properties with reduced Spn might account for the malignant phenotype observed in Spn-loss tumors and may contribute to a worse patient prognosis.

  14. Mxd1 mediates hypoxia-induced cisplatin resistance in osteosarcoma cells by repression of the PTEN tumor suppressor gene.

    Science.gov (United States)

    Zheng, Datong; Wu, Weiling; Dong, Na; Jiang, Xiuqin; Xu, Jinjin; Zhan, Xi; Zhang, Zhengdong; Hu, Zhenzhen

    2017-10-01

    Hypoxia-induced chemoresistance remains a major obstacle to treating osteosarcoma effectively. Mxd1, a member of the Myc/Max/Mxd family, was shown to be involved in the development of drug resistance under hypoxia. However, the effect of Mxd1 on hypoxia-induced cisplatin (CDDP) resistance and its mechanism in osteosarcoma have not been fully elucidated. In this study, we demonstrated that HIF-1α-induced Mxd1 contributed to CDDP resistance in hypoxic U-2OS and MG-63 cells. The knockdown of Mxd1 expression elevated PTEN expression at both protein and RNA levels in these hypoxic cells. Using Luciferase reporter and ChIP assays, we confirmed that Mxd1 directly bound to the E-box sites within the PTEN promoter region. We further demonstrated that PTEN knockdown decreased CDDP sensitivity in Mxd1 siRNA-transfected U-2OS and MG-63 cells under hypoxia. Our results also showed that Mxd1 deficiency in hypoxic U-2OS and MG-63 cells lead to inactivation of PI3K/AKT signaling, which is the downstream of PTEN. Furthermore, blockade of PI3K/AKT signal re-sensitized hypoxic U-2OS and MG-63 cells to CDDP. Taken together, these findings suggest that HIF-1α-induced Mxd1 up-regulation suppresses the expression of PTEN under hypoxia, which leads to the activation of PI3K/AKT antiapoptotic and survival pathway. As a result CDDP resistance in osteosarcoma cells is induced. © 2017 Wiley Periodicals, Inc.

  15. Modulation of allogeneic stimulation in man. I. Characterization of an in vitro induced suppressor macrophage population

    International Nuclear Information System (INIS)

    Stux, S.V.; Dubey, D.P.; Yunis, E.J.

    1981-01-01

    Cultured human peripheral blood mononuclear cells suppressed the allogeneic response of fresh autologous lymphocytes. This suppressor activity developed gradually over a period of one week. The cells primarily responsible for this effect were enriched by Ficoll density gradient centrifugation. It was found that the suppressor cell is a large, low density nylon wool adherent, radioresistant, phagocytic, and nonspecific esterase positive mononuclear cell. Moreover, these cells did not form E rosettes and were Fc positive. Electron microscopy confirmed that suppressor cells were macrophage like. Suppressor activity was not due to cytotoxicity, crowding, or steric hinderance by the cultured cells. The suppressor macrophage population did not appear to inhibit the allogeneic response via prostaglandin or arginase release, or interfere with the tritiated thymidine uptake by release of endogenous thymidine. The above system is viewed as an in vitro model of immune regulation by suppressor macrophages, in the context of allogeneic response

  16. miRNA-34b as a tumor suppressor in estrogen-dependent growth of breast cancer cells

    Science.gov (United States)

    2011-01-01

    Introduction Estrogen is involved in several physiological and pathological processes through estrogen receptor (ER)-mediated transcriptional gene regulation. miRNAs (miRs), which are noncoding RNA genes, may respond to estrogen and serve as posttranscriptional regulators in tumorigenic progression, especially in breast cancer; however, only limited information about this possibility is available. In the present study, we identified the estrogen-regulated miR-34b and investigated its functional role in breast cancer progression. Methods Estrogen-regulated miRNAs were identified by using a TaqMan low density array. Our in vivo Tet-On system orthotopic model revealed the tumor-suppressive ability of miR-34b. Luciferase reporter assays and chromatin immunoprecipitation assay demonstrated miR-34b were regulated by p53-ER interaction. Results In this study, we identified one such estrogen downregulated miRNA, miR-34b, as an oncosuppressor that targets cyclin D1 and Jagged-1 (JAG1) in an ER+/wild-type p53 breast cancer cell line (MCF-7), as well as in ovarian and endometrial cells, but not in ER-negative or mutant p53 breast cancer cell lines (T47D, MBA-MB-361 and MDA-MB-435). There is a negative association between ERα and miR-34b expression levels in ER+ breast cancer patients. Tet-On induction of miR-34b can cause inhibition of tumor growth and cell proliferation. Also, the overexpression of miR-34b inhibited ER+ breast tumor growth in an orthotopic mammary fat pad xenograft mouse model. Further validation indicated that estrogen's inhibition of miR-34b expression was mediated by interactions between ERα and p53, not by DNA methylation regulation. The xenoestrogens diethylstilbestrol and zeranol also showed similar estrogenic effects by inhibiting miR-34b expression and by restoring the protein levels of the miR-34b targets cyclin D1 and JAG1 in MCF-7 cells. Conclusions These findings reveal that miR-34b is an oncosuppressor miRNA requiring both ER+ and wild-type p

  17. Modulation of Stem Cells Differentiation and Myostatin as an Approach to Counteract Fibrosis in Muscle Dystrophy and Regeneration after Injury

    National Research Council Canada - National Science Library

    Gonzalez, Nestor F

    2008-01-01

    ...) Wt MDSC express an embryonic stem cell marker Oct-4 and cells positive for this marker were located in vivo in the skeletal muscle using a transgenic mouse model that detects Oct-4 expression with a reporter gene; 3...

  18. Enhanced suppressor cell activity as a mechanism of immunosuppression by 2,3,7,8-tetrachlorodibenzo-p-dioxin

    Energy Technology Data Exchange (ETDEWEB)

    Clark, D.A.; Gauldie, J.; Szewczuk, M.R.; Sweeney, G.

    1981-11-01

    TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin), a toxic halogenated aromatic hydrocarbon, acts in the body as a cumulative poison. The chronic immunotoxic effects of TCDD were studied in C57B1/6 male mice. Total doses of 100 ..mu..g/kg or greater produced cellular depletion in thymus, spleen, and lymph nodes, and the animals appeared sick. No cellular depletion was seen following 0.4 ..mu..g/kg, and only thymus was affected by 4 and 40 ..mu..g/kg. The antibody response to SRBC and TNP-Brucella abortus was impaired following ..mu..g/kg and the generation of alloantigen-specific cytotoxic T cells (CTL) was sensitive to as little as 0.004 ..mu..g/kg TCDD. In vitro analysis of the mechanism of suppression using limiting dilution techniques showed that TCDD did not deplete the precursors of CTL but generated cells capable of suppressing CTL generation in vitro.

  19. Physical mapping of a commonly deleted region, the site of a candidate tumor suppressor gene, at 12q22 in human male germ cell tumors

    Energy Technology Data Exchange (ETDEWEB)

    Murty, V.V.V.S.; Bosl, G.J.; Chaganti, R.S.K. [Memorial Sloan-Kettering Cancer Center, New York, NY (United States)] [and others

    1996-08-01

    A candidate tumor suppressor gene (TSG) site at 12q22 characterized by a high frequency of loss of heterozygosity (LOH) and a homozygous deletion has previously (LOH) and a homozygous deletion has previously been reported in human male germ cell tumors (GCTs). In a detailed deletion mapping analysis of 67 normal-tumor DNAs utilizing 20 polymorphic markers mapped to 12q22-q24, we identified the limits of the minimal region of deletion at 12q22 between D12S377 (priximal) and D12S296 (distal). We have constructed a YAC contig map of a 3-cM region of this band between the proximal marker D12S101 and the distal marker D12S346, which contained the minimal region of deletion in GCTs. The map is composed of 53 overlapping YACs and 3 cosmids onto which 25 polymorphic and nonpolymorphic sequence-tagged sites (STSs) were placed in a unique order. The size of the minimal region of deletion was approximately 2 Mb from overlapping, nonchimeric YACs that spanned the region. We also developed a radiation hybrid (RH) map of the region between D12S101 and D12S346 containing 17 loci. The consensus order developed by RH mapping is in good agreement with the YAC STS-content map order. The RH map estimated the distance between D12S101 and D12S346 to be 246 cR{sub 8000} and the minimal region of deletion to be 141 cR{sub 8000}. In addition, four genes that were previously mapped to 12q22 have been excluded as candidate genes. The leads gained from the deletion mapping and physical maps should expedite the isolation and characterization of the TSG at 12q22. 35 refs., 4 figs., 2 tabs.

  20. Consumption of soy isoflavone enriched bread in men with prostate cancer is associated with reduced proinflammatory cytokines and immunosuppressive cells.

    Science.gov (United States)

    Lesinski, Gregory B; Reville, Patrick K; Mace, Thomas A; Young, Gregory S; Ahn-Jarvis, Jennifer; Thomas-Ahner, Jennifer; Vodovotz, Yael; Ameen, Zeenath; Grainger, Elizabeth; Riedl, Kenneth; Schwartz, Steven; Clinton, Steven K

    2015-11-01

    We hypothesized that soy phytochemicals may have immunomodulatory properties that may affect prostate carcinogenesis and progression. A randomized, phase II trial was conducted in 32 patients with prostate cancer with asymptomatic biochemical recurrence but no measurable disease on standard staging studies. Patients were randomized to two slices of soy bread (34 mg isoflavones/slice) or soy bread containing almond powder daily as a source of β-glucosidase. Flow cytometry and bioplex assays were used to measure cytokines or immune cell phenotype in blood at baseline (day 0) and following intervention (day 56). Adequate blood samples were available at enrollment and day 56 and evaluated. Multiple plasma cytokines and chemokines were significantly decreased on day 56 versus baseline. Subgroup analysis indicated reduced TH1 (P = 0.028) and myeloid-derived suppressor cell (MDSC)-associated cytokines (P = 0.035). TH2 and TH17 cytokines were not significantly altered. Phenotypic analysis revealed no change in CD8(+) or CD4(+) T cells but showed increased CD56(+) natural killer (NK) cells (P = 0.038). The percentage of cells with a T regulatory cell phenotype (CD4(+)CD25(+)FoxP3(+)) was significantly decreased after 56 days of soy bread (P = 0.0136). Significantly decreased monocytic (CD33(+)HLADR(neg)CD14(+)) MDSC were observed in patients consuming soy bread (P = 0.0056). These data suggest that soy bread modulates systemic soluble and cellular biomarkers consistent with limiting inflammation and suppression of MDSCs. Additional studies to elucidate impact on the carcinogenic process or as a complement to immune-based therapy are required. ©2015 American Association for Cancer Research.

  1. Regulation of the PML tumor suppressor in drug-induced senescence of human normal and cancer cells by JAK/STAT-mediated signaling

    Czech Academy of Sciences Publication Activity Database

    Hubáčková, Soňa; Nováková, Zora; Krejčíková, Kateřina; Košař, Martin; Dobrovolná, Jana; Dušková, Pavlína; Hanzlíková, Hana; Vančurová, Markéta; Barath, P.; Bartek, J.; Hodný, Zdeněk

    2010-01-01

    Roč. 9, č. 15 (2010), s. 3085-3099 ISSN 1538-4101 R&D Projects: GA AV ČR IAA500390501; GA ČR GA204/08/1418; GA ČR GA301/08/0353 Institutional research plan: CEZ:AV0Z50520514 Keywords : PML tumor suppressor * cellular senescence * JAK-STAT signaling pathway Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.999, year: 2010

  2. A genome-wide siRNA screen for regulators of tumor suppressor p53 activity in human non-small cell lung cancer cells identifies components of the RNA splicing machinery as targets for anticancer treatment.

    Science.gov (United States)

    Siebring-van Olst, Ellen; Blijlevens, Maxime; de Menezes, Renee X; van der Meulen-Muileman, Ida H; Smit, Egbert F; van Beusechem, Victor W

    2017-05-01

    Reinstating wild-type tumor suppressor p53 activity could be a valuable option for the treatment of cancer. To contribute to development of new treatment options for non-small cell lung cancer (NSCLC), we performed genome-wide siRNA screens for determinants of p53 activity in NSCLC cells. We identified many genes not previously known to be involved in regulating p53 activity. Silencing p53 pathway inhibitor genes was associated with loss of cell viability. The largest functional gene cluster influencing p53 activity was mRNA splicing. Prominent p53 activation was observed upon silencing of specific spliceosome components, rather than by general inhibition of the spliceosome. Ten genes were validated as inhibitors of p53 activity in multiple NSCLC cell lines: genes encoding the Ras pathway activator SOS1, the zinc finger protein TSHZ3, the mitochondrial membrane protein COX16, and the spliceosome components SNRPD3, SF3A3, SF3B1, SF3B6, XAB2, CWC22, and HNRNPL. Silencing these genes generally increased p53 levels, with distinct effects on CDKN1A expression, induction of cell cycle arrest and cell death. Silencing spliceosome components was associated with alternative splicing of MDM4 mRNA, which could contribute to activation of p53. In addition, silencing splice factors was particularly effective in killing NSCLC cells, albeit in a p53-independent manner. Interestingly, silencing SNRPD3 and SF3A3 exerted much stronger cytotoxicity to NSCLC cells than to lung fibroblasts, suggesting that these genes could represent useful therapeutic targets. © 2017 The Authors. Published by FEBS Press and John Wiley & Sons Ltd.

  3. Mutations blocking side chain assembly, polymerization, or transport of a Wzy-dependent Streptococcus pneumoniae capsule are lethal in the absence of suppressor mutations and can affect polymer transfer to the cell wall.

    Science.gov (United States)

    Xayarath, Bobbi; Yother, Janet

    2007-05-01

    Extracellular polysaccharides of many bacteria are synthesized by the Wzy polymerase-dependent mechanism, where long-chain polymers are assembled from undecaprenyl-phosphate-linked repeat units on the outer face of the cytoplasmic membrane. In gram-positive bacteria, Wzy-dependent capsules remain largely cell associated via membrane and peptidoglycan linkages. Like many Wzy-dependent capsules, the Streptococcus pneumoniae serotype 2 capsule is branched. In this study, we found that deletions of cps2K, cps2J, or cps2H, which encode a UDP-glucose dehydrogenase necessary for side chain synthesis, the putative Wzx transporter (flippase), and the putative Wzy polymerase, respectively, were obtained only in the presence of suppressor mutations. Most of the suppressor mutations were in cps2E, which encodes the initiating glycosyltransferase for capsule synthesis. The cps2K mutants containing the suppressor mutations produced low levels of high-molecular-weight polymer that was detected only in membrane fractions. cps2K-repaired mutants exhibited only modest increases in capsule production due to the effect of the secondary mutation, but capsule was detectable in both membrane and cell wall fractions. Lethality of the cps2K, cps2J, and cps2H mutations was likely due to sequestration of undecaprenyl-phosphate in the capsule pathway and either preclusion of its turnover for utilization in essential pathways or destabilization of the membrane due to an accumulation of lipid-linked intermediates. The results demonstrate that proper polymer assembly requires not only a functional transporter and polymerase but also complete repeat units. A central role for the initiating glycosyltransferase in controlling capsule synthesis is also suggested.

  4. An endothelial cell genetic screen identifies the GTPase Rem2 as a suppressor of p19ARF expression that promotes endothelial cell proliferation and angiogenesis

    NARCIS (Netherlands)

    Bierings, Ruben; Beato, Miguel; Edel, Michael J.

    2008-01-01

    Angiogenesis requires an increase in endothelial cell proliferation to support an increase in mass of blood vessels. We designed an in vitro endothelial cell model to functionally screen for genes that regulate endothelial cell proliferation. A gain of function screen for genes that bypass p53

  5. Tumor suppressor gene p16/INK4A/CDKN2A-dependent regulation into and out of the cell cycle in a spontaneous canine model of breast cancer.

    Science.gov (United States)

    Agarwal, Payal; Sandey, Maninder; DeInnocentes, Patricia; Bird, R Curtis

    2013-06-01

    p16/INK4A/CDKN2A is an important tumor suppressor gene that arrests cell cycle in G1 phase inhibiting binding of CDK4/6 with cyclin D1, leaving the Rb tumor suppressor protein unphosphorylated and E2F bound and inactive. We hypothesized that p16 has a role in exit from cell cycle that becomes defective in cancer cells. Well characterized p16-defective canine mammary cancer cell lines (CMT28, CMT27, and CMT12), derived stably p16-transfected CMT cell clones (CMT27A, CMT27H, CMT28A, and CMT28F), and normal canine fibroblasts (NCF), were used to investigate expression of p16 after serum starvation into quiescence followed by re-feeding to induce cell cycle re-entry. The parental CMT cell lines used lack p16 expression either at the mRNA or protein expression levels, while p27 and other p16-associated proteins, including CDK4, CDK6, cyclin D1, and Rb, were expressed. We have successfully demonstrated cell cycle arrest and relatively synchronous cell cycle re-entry in parental CMT12, CMT28 and NCF cells as well as p16 transfected CMT27A, CMT27H, CMT28A, and CMT28F cells and confirmed this by (3)H-thymidine incorporation and flow cytometric analysis of cell cycle phase distribution. p16-transfected CMT27A and CMT27H cells exited cell cycle post-serum-starvation in contrast to parental CMT27 cells. NCF, CMT27A, and CMT28F cells expressed upregulated levels of p27 and p16 mRNA, post-serum starvation, as cells exited cell cycle and entered quiescence. Because quiescence and differentiation are associated with increased levels of p27, our data demonstrating that p16 was upregulated along with p27 during quiescence, suggests a potential role for p16 in maintaining these non-proliferative states. Copyright © 2012 Wiley Periodicals, Inc.

  6. miR-485 acts as a tumor suppressor by inhibiting cell growth and migration in breast carcinoma T47D cells.

    Science.gov (United States)

    Anaya-Ruiz, Maricruz; Bandala, Cindy; Perez-Santos, Jose Luis Martin

    2013-01-01

    MicroRNAs (miRNAs) are small, non-coding RNAs (18-25 nucleotides) that post-transcriptionally modulate gene expression by negatively regulating the stability or translational efficiency of their target mRNAs. In this context, the present study aimed to evaluate the in vitro effects of miR-485 mimics in breast carcinoma T47D cells. Forty-eight hours after T47D cells were transfected with miR-485 mimics, an MTT (3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide) assay was utilized to determine the effects on cell viability. Colony formation and cell migration assays were adopted to determine whether miR-485 affects the proliferation rates and cell migration of breast carcinoma T47D cells. Our results showed that ectopic expression of miR-485 resulted in a significant decrease in cell growth, cell colony formation, and cell migration. These findings suggest that miR- 485 might play an important role in breast cancer by suppressing cell proliferation and migration.

  7. Targeting the cell cycle and the PI3K pathway: a possible universal strategy to reactivate innate tumor suppressor programmes in cancer cells.

    Science.gov (United States)

    David-Pfeuty, Thérèse; Legraverend, Michel; Ludwig, Odile; Grierson, David S

    2010-04-01

    Corruption of the Rb and p53 pathways occurs in virtually all human cancers. This could be because it lends oncogene-bearing cells a surfeit of Cdk activity and growth, enabling them to elaborate strategies to evade tumor-suppressive mechanisms and divide inappropriately. Targeting both Cdk activities and the PI3K pathway might be therefore a potentially universal means to palliate their deficiency in cancer cells. We showed that the killing efficacy of roscovitine and 16 other purines and potentiation of roscovitine-induced apoptosis by the PI3K inhibitor, LY294002, decreased with increasing corruption of the Rb and p53 pathways. Further, we showed that purines differing by a single substitution, which exerted little lethal effect on distant cell types in rich medium, could display widely-differing cytotoxicity profiles toward the same cell types in poor medium. Thus, closely-related compounds targeting similar Cdks may interact with different targets that could compete for their interaction with therapeutically-relevant Cdk targets. In the perspective of clinical development in association with the PI3K pathway inhibitors, it might thus be advisable to select tumor cell type-specific Cdk inhibitors on the basis of their toxicity in cell-culture-based assays performed at a limiting serum concentration sufficient to suppress their interaction with undesirable crossreacting targets whose range and concentration would depend on the cell genotype.

  8. MicroRNA-429 induces tumorigenesis of human non-small cell lung cancer cells and targets multiple tumor suppressor genes

    Energy Technology Data Exchange (ETDEWEB)

    Lang, Yaoguo; Xu, Shidong; Ma, Jianqun; Wu, Jun [Department of Thoracic Surgery, Harbin Medical University Cancer Hospital, 150 Haping Road, Harbin, Heilongjiang 150081 (China); Jin, Shi; Cao, Shoubo [Department of Medical Oncology, Harbin Medical University Cancer Hospital, 150 Haping Road, Harbin, Heilongjiang 150081 (China); Yu, Yan, E-mail: yuyan@hrbmu.edu.cn [Department of Medical Oncology, Harbin Medical University Cancer Hospital, 150 Haping Road, Harbin, Heilongjiang 150081 (China)

    2014-07-18

    Highlights: • MiR-429 expression is upregulated in non-small cell lung cancer (NSCLC). • MiR-429 inhibits PTEN, RASSF8 and TIMP2 expression. • MiR-429 promotes metastasis and proliferation. • We report important regulatory mechanisms involved in NSCLC progression. • MiR-429 is a potential therapeutic target and diagnostic marker. - Abstract: Lung cancer is the major cause of cancer death globally. MicroRNAs are evolutionally conserved small noncoding RNAs that are critical for the regulation of gene expression. Aberrant expression of microRNA (miRNA) has been implicated in cancer initiation and progression. In this study, we demonstrated that the expression of miR-429 are often upregulated in non-small cell lung cancer (NSCLC) compared with normal lung tissues, and its expression level is also increased in NSCLC cell lines compared with normal lung cells. Overexpression of miR-429 in A549 NSCLC cells significantly promoted cell proliferation, migration and invasion, whereas inhibition of miR-429 inhibits these effects. Furthermore, we demonstrated that miR-429 down-regulates PTEN, RASSF8 and TIMP2 expression by directly targeting the 3′-untranslated region of these target genes. Taken together, our results suggest that miR-429 plays an important role in promoting the proliferation and metastasis of NSCLC cells and is a potential target for NSCLC therapy.

  9. Targeting activating mutations of EZH2 leads to potent cell growth inhibition in human melanoma by derepression of tumor suppressor genes

    OpenAIRE

    Tiffen, Jessamy C.; Gunatilake, Dilini; Gallagher, Stuart J.; Gowrishankar, Kavitha; Heinemann, Anja; Cullinane, Carleen; Dutton-Regester, Ken; Pupo, Gulietta M.; Strbenac, Dario; Yang, Jean Y.; Madore, Jason; Mann, Graham J.; Hayward, Nicholas K.; McArthur, Grant A.; Filipp, Fabian V.

    2015-01-01

    The epigenetic modifier EZH2 is part of the polycomb repressive complex that suppresses gene expression via histone methylation. Activating mutations in EZH2 are found in a subset of melanoma that contributes to disease progression by inactivating tumor suppressor genes. In this study we have targeted EZH2 with a specific inhibitor (GSK126) or depleted EZH2 protein by stable shRNA knockdown. We show that inhibition of EZH2 has potent effects on the growth of both wild-type and EZH2 mutant hum...

  10. The putative tumor suppressor, miR-199a, regulated by Snail, modulates clear cell renal cell carcinoma aggressiveness by repressing ROCK1.

    Science.gov (United States)

    Zhang, Xiao; Li, Peng; Ding, Zhen; Wang, Huili; Wang, Junye; Han, Lei; Ding, Shangwei

    2018-01-01

    Aberrant expression of miR-199a has been frequently reported in cancer studies; however, its role in renal cell carcinoma (RCC) has not been examined in detail. Here, we showed that miR-199a was downregulated in RCC and associated with poor prognostic phenotype. Using luciferase and western blot assays we identified that Rho-associated coiled coil-containing protein kinases 1 (ROCK1) was a direct target gene for miR-199a. miR-199a regulated proliferation, invasion, and apoptosis of clear cell renal cell carcinoma (ccRCC) cells by modulating ROCK1 expression. Interestingly, we also found that miR-199a was modulated by snail in ccRCC cells. Snail elevated ROCK1 expression by repressing miR-199a activity. Altogether, our results identify a crucial tumor suppressive role of miR-199a in the progression of ccRCC and suggest that miR-199a might be an anticancer therapeutic target for ccRCC patients.

  11. Activation of human T-helper/inducer cell, T-cytotoxic/suppressor cell, B-cell, and natural killer (NK)-cells and induction of NK cell activity against K562 chronic myeloid leukemia cells with modified citrus pectin

    Science.gov (United States)

    Background Modified citrus pectin (MCP) is known for its anti-cancer effects and its ability to be absorbed and circulated in the human body. In this report we tested the ability of MCP to induce the activation of human blood lymphocyte subsets including T-helper/inducer cell, Tcytotoxic/suppres...

  12. Suppressor cell hyperactivity relative to allogeneic lymphocyte proliferation as a manifestation of defective T-T-cell interactions in systemic lupus erythematosus

    International Nuclear Information System (INIS)

    Stenina, M.A.; Potapova, A.A.; Biryukov, A.V.; Skripnik, A.Yu.; Cheredeev, A.N.

    1987-01-01

    The authors study the state of immunoregulatory process in patients with systemic lupus erythematosus at the T-T-cell interaction level and seek to test the possibility of the pharmacological modulation of this process. The proliferative activity of mononuclear lymphocytes, extracted from the blood of ten lupus patients, was assessed by measuring the incorporation of tritiated thymidine into cultures stimulated by phytohemagglutinin, concanavalin, and theophylline. The comparative effects of each of these agents on the immunoregulatory and proliferative activity of the lymphocytes are reported

  13. Viral suppression of multiple escape mutants by de novo CD8+ T cell responses in a human immunodeficiency virus-1 Infected elite suppressor

    Directory of Open Access Journals (Sweden)

    Siliciano Robert F

    2011-08-01

    Full Text Available Abstract Elite suppressors or controllers (ES are HIV-1 infected patients who maintain undetectable viral loads without treatment. While HLA-B*57-positive ES are usually infected with virus that is unmutated at CTL epitopes, a single, dominant variant containing CTL escape mutations is typically seen in plasma during chronic infection. We describe an ES who developed seven distinct and rare escape variants at an HLA-B*57-restricted Gag epitope over a five year period. Interestingly, he developed proliferative, de novo CTL responses that suppressed replication of each of these variants. These responses, in combination with low viral fitness of each variant, may contribute to sustained elite control in this ES.

  14. P53 tumor suppressor gene and protein expression is altered in cell lines derived from spontaneous and alpha-radiation-induced canine lung tumors

    International Nuclear Information System (INIS)

    Tierney, L.A.; Johnson, N.F.; Lechner, J.F.

    1994-01-01

    Mutations in the p53 tumor suppressor gene are the most frequently occurring gene alterations in malignant human cancers, including lung cancer. In lung cancer, common point mutations within conserved exons of the p53 gene result in a stabilized form of mutant protein which is detectable in most cases by immunohistochemistry. In addition to point mutations, allelic loss, rearrangements, and deletions of the p53 gene have also been detected in both human and rodent tumors. It has been suggested that for at least some epithelial neoplasms, the loss of expression of wild-type p53 protein may be more important for malignant transformation than the acquisition of activating mutations. Mechanisms responsible for the loss of expression of wild-type protein include gene deletion or rearrangement, nonsense or stop mutations, mutations within introns or upstream regulatory regions of the gene, and accelerated rates of degradation of the protein by DNA viral oncoproteins

  15. LncRNAs as an intermediate in HPV16 promoting myeloid-derived suppressor cell recruitment of head and neck squamous cell carcinoma

    Science.gov (United States)

    Jiang, Yaping; Gao, Xiaolei; Cen, Xiao; Wu, Jiashun; Wang, Shasha; Tang, Yajie; Tang, Yaling; Liang, Xinhua

    2017-01-01

    The emerging evidence showed that long noncoding RNAs (lncRNAs) are involved in cell growth and apoptosis as well as cancer progression and metastasis of malignant tumor, however, limited data are available on the role of lncRNAs in human papillomavirus (HPV)-associated Head and neck squamous cell carcinomas (HNSCC). Here, we demonstrated that 23.98% of 196 HNSCC cases in Southwest China could be classified as HPV16 infection. The number of MDSCs in HPV-positive HNSCC was significantly higher than normal control, indicating that HPV infection may promote MDSCs aggregation. Then, we applied an array-based approach to monitor the lncRNA expression between HPV-positive HNSCC, HPV-negative HNSCC and normal oral mucous, and obtained 132 different lncRNAs in different HPV infected states of HNSCC. HOTAIR, PROM1, CCAT1, and MUC19 mRNA levels, determined by qRT-PCR were inversely correlated with MDSCs collection of HPV-associated HNSCC in 2 independent patient cohorts. The results may provide a rationale for the further evaluation of lncRNAs as a molecular target to elucidate the molecular mechanism of HPV promoting MDSCs collection of HNSCC. PMID:28159935

  16. Circulating CD8+CD28- suppressor T cells tied to poorer prognosis among metastatic breast cancer patients receiving adoptive T-cell therapy: A cohort study.

    Science.gov (United States)

    Song, Qingkun; Ren, Jun; Zhou, Xinna; Wang, Xiaoli; Song, Guohong; Hobeika, Amy; Yuan, Yanhua; Lyerly, Herbert Kim

    2018-01-01

    This study aimed to determine the prognostic value of circulating CD8 + CD28 - T lymphocytes among breast cancer patients treated with adoptive T-lymphocyte immunotherapy after chemotherapy. Two hundred and thirty-two breast cancer patients underwent adoptive T-cell immunotherapy. Circulating CD8 + CD28 - proportion was measured by flow cytometry. Median proportion of CD8 + CD28 - was 24.2% and set as the categorical cutoff value for further analysis. The median survival was estimated by Kaplan-Meier curve, with difference detection and hazard ratio estimation by log-rank test and Cox hazard proportion regression model. With adoptive T-cell therapy, patients with higher CD8 + CD28 - levels experienced median progression-free and overall survival of 7.1 months and 26.9 months, respectively-significantly shorter than patients with lower levels (11.8 and 36.2 months). CD8 + CD28 - proportion >24.2% demonstrated a hazard ratio (HR) of 2.06 (95% confidence interval [CI] 1.31-3.12) for progression and an HR of 1.97 (95% CI 1.06-3.67) for death. Among patients who had received previous first-line chemotherapy, CD8 + CD28 - proportion >24.2% demonstrated an HR of 2.66 (95% CI 1.45-4.88) for progression. Among patients exposed to previous second-line or higher chemotherapy, CD8 + CD28 - proportion >24.2% demonstrated a 486% higher risk for death (HR = 5.86, 95% CI 1.77-19.39). A 1% increase in suppressive T cells was associated with a 5% increased risk of death. Elevated peripheral blood CD8 + CD28 - was associated with poorer prognosis for metastatic breast cancer, especially for higher risk of progression among patients with first-line chemotherapy and higher risk of death among patients with more than second-line chemotherapy. Copyright © 2017 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

  17. RET is a potential tumor suppressor gene in colorectal cancer

    Science.gov (United States)

    Luo, Yanxin; Tsuchiya, Karen D.; Park, Dong Il; Fausel, Rebecca; Kanngurn, Samornmas; Welcsh, Piri; Dzieciatkowski, Slavomir; Wang, Jianping; Grady, William M.

    2012-01-01

    Cancer arises as the consequence of mutations and epigenetic alterations that activate oncogenes and inactivate tumor suppressor genes. Through a genome-wide screen for methylated genes in colon neoplasms, we identified aberrantly methylated RET in colorectal cancer. RET, a transmembrane receptor tyrosine kinase and a receptor for the GDNF-family ligands, was one of the first oncogenes to be identified and has been shown to be an oncogene in thyroid cancer and pheochromocytoma. However, unexpectedly, we found RET is methylated in 27% of colon adenomas and in 63% of colorectal cancers, and now provide evidence that RET has tumor suppressor activity in colon cancer. The aberrant methylation of RET correlates with decreased RET expression, whereas the restoration of RET in colorectal cancer cell lines results in apoptosis. Furthermore, in support of a tumor suppressor function of RET, mutant RET has also been found in primary colorectal cancer. We now show that these mutations inactivate RET, which is consistent with RET being a tumor suppressor gene in the colon. These findings suggest that the aberrant methylation of RET and the mutational inactivation of RET promote colorectal cancer formation and that RET can serve as a tumor suppressor gene in the colon. Moreover, the increased frequency of methylated RET in colon cancers compared to adenomas suggests RET inactivation is involved in the progression of colon adenomas to cancer. PMID:22751117

  18. Suppressors of DnaAATP imposed overinitiation in Escherichia coli

    DEFF Research Database (Denmark)

    Charbon, Godefroid; Riber, Leise; Cohen, Malene

    2011-01-01

    Chromosome replication in Escherichia coli is limited by the supply of DnaA associated with ATP. Cells deficient in RIDA (Regulatory Inactivation of DnaA) due to a deletion of the hda gene accumulate suppressor mutations (hsm) to counteract the overinitiation caused by an elevated DnaAATP level...

  19. Surgical Stress Abrogates Pre-Existing Protective T Cell Mediated Anti-Tumor Immunity Leading to Postoperative Cancer Recurrence.

    Directory of Open Access Journals (Sweden)

    Abhirami A Ananth

    Full Text Available Anti-tumor CD8+ T cells are a key determinant for overall survival in patients following surgical resection for solid malignancies. Using a mouse model of cancer vaccination (adenovirus expressing melanoma tumor-associated antigen (TAA-dopachrome tautomerase (AdDCT and resection resulting in major surgical stress (abdominal nephrectomy, we demonstrate that surgical stress results in a reduction in the number of CD8+ T cell that produce cytokines (IFNγ, TNFα, Granzyme B in response to TAA. This effect is secondary to both reduced proliferation and impaired T cell function following antigen binding. In a prophylactic model, surgical stress completely abrogates tumor protection conferred by vaccination in the immediate postoperative period. In a clinically relevant surgical resection model, vaccinated mice undergoing a positive margin resection with surgical stress had decreased survival compared to mice with positive margin resection alone. Preoperative immunotherapy with IFNα significantly extends survival in surgically stressed mice. Importantly, myeloid derived suppressor cell (MDSC population numbers and functional impairment of TAA-specific CD8+ T cell were altered in surgically stressed mice. Our observations suggest that cancer progression may result from surgery-induced suppression of tumor-specific CD8+ T cells. Preoperative immunotherapies aimed at targeting the prometastatic effects of cancer surgery will reduce recurrence and improve survival in cancer surgery patients.

  20. The in vitro and in vivo effects of re-expressing methylated von Hippel-Lindau tumor suppressor gene in clear cell renal carcinoma with 5-aza-2'-deoxycytidine.

    Science.gov (United States)

    Alleman, Wade G; Tabios, Ray L; Chandramouli, Gadisetti V R; Aprelikova, Olga N; Torres-Cabala, Carlos; Mendoza, Arnulfo; Rogers, Craig; Rodgers, Craig; Sopko, Nikolai A; Linehan, W Marston; Vasselli, James R

    2004-10-15

    Clear cell renal carcinoma (ccRCC) is strongly associated with loss of the von Hippel-Lindau (VHL) tumor suppressor gene. The VHL gene is functionally lost through hypermethylation in up to 19% of sporadic ccRCC cases. We theorized that re-expressing VHL silenced by methylation in ccRCC cells, using a hypo-methylating agent, may be an approach to treatment in patients with this type of cancer. We test the ability of two hypo-methylating agents to re-express VHL in cell culture and in mice bearing human ccRCC and evaluate the effects of re-expressed VHL in these models. Real-time reverse transcription-PCR was used to evaluate the ability of zebularine and 5-aza-2'-deoxycytidine (5-aza-dCyd) to re-express VHL in four ccRCC cell lines with documented VHL gene silencing through hypermethylation. We evaluated if the VHL re-expressed after hypo-methylating agent treatment could recreate similar phenotypic changes in ccRCC cells observed when the VHL gene is re-expressed via transfection in cell culture and in a xenograft mouse model. Finally we evaluate global gene expression changes occurring in our cells, using microarray analysis. 5-Aza-dCyd was able to re-express VHL in our cell lines both in culture and in xenografted murine tumors. Well described phenotypic changes of VHL expression including decreased invasiveness into Matrigel, and decreased vascular endothelial growth factor and glucose transporter-1 expression were observed in the treated lines. VHL methylated ccRCC xenografted tumors were significantly reduced in size in mice treated with 5-aza-dCyd. Mice bearing nonmethylated but VHL-mutated tumors showed no tumor shrinkage with 5-aza-dCyd treatment. Hypo-methylating agents may be useful in the treatment of patients having ccRCC tumors consisting of cells with methylated VHL.

  1. The tumor suppressor phosphatase and tensin homolog protein (PTEN) is negatively regulated by NF-κb p50 homodimers and involves histone 3 methylation/deacetylation in UROtsa cells chronically exposed to monomethylarsonous acid.

    Science.gov (United States)

    Oliva-González, C; Uresti-Rivera, E E; Galicia-Cruz, O G; Jasso-Robles, F I; Gandolfi, A J; Escudero-Lourdes, C

    2017-10-05

    UROtsa cells have been accepted as a model to study carcinogenicity mechanisms of arsenic-associated human bladder cancer. In vitro continuous exposure to monomethylarsonous acid (MMA III ), leads UROtsa cells to commit to malignant transformation. In this process, NF-κβ-associated inflammatory response seems to play an important role since this transcription factor activates some minutes after cells are exposed in vitro to MMA III and keeps activated during the cellular malignant transformation. It is known that a slight decrease in the protein phosphatase and tensin homologue (PTEN) gene expression is enough for some cells to become malignantly transformed. Interestingly, this tumor suppressor has been proven to be negatively regulated by NF-κβ through binding to its gene promoter. Based on these observations we propose that NF-κβ may be involved in arsenic associated carcinogenesis through the negative regulation of PTEN gene expression. Changes in PTEN expression and the binding of p50 NF-κβ subunit to PTEN promoter were evaluated in UROtsa cells exposed for 4, 12, 20, or 24 wk to 50nM MMA III . Results showed that MMA III induced a significant decrease in PTEN expression around 20 wk exposure to MMA III ,which correlated with increased binding of p50 subunit to the PTEN promoter. Consistent with these results, ChIP assays also showed a significant decrease in H3 acetylation (H3ac) but an increase in the repression marks H3k9me3 and H327me3 in PTEN promoter when compared with not treated cells. These results suggest that the activation of NF-κβ by MMA III may participate in UROtsa cells malignant transformation through the negative regulation of PTEN expression involving p50 homodimers-mediated chromatin remodeling around the PTEN promoter. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Surveillance on the status of immune cells after Echinnococcus granulosus protoscoleces infection in Balb/c mice.

    Directory of Open Access Journals (Sweden)

    Wei Pan

    Full Text Available BACKGROUND: Cystic echinococcosis is a global parasitic disease caused by infection with Echinococcus granulosus larvae with potentially life-threatening complications in humans. To date, the status of the immune cells believed to be associated with the pathogenicity of E. granulosus infection has not been demonstrated clearly. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we developed a multiplex flow cytometry assay to investigate the systemic immune status of innate and adaptive immunity at 30, 180, 360 days post-infection (dpi in mice infected with E. granulousus. At 30 dpi, an increase in the number of CD11b(+ and CD11c(+ antigen-presenting cells (APCs was observed. This was accompanied by the slight down-regulated expression of the co-stimulatory molecule MHC-II, indicating the impairment of APCs in early infection through the release of secretory-excretory products. In all infected groups, we observed a significant increase in innate immune cells, including APCs and GR-1(+ cells, and a dramatic increase in the myeloid-derived suppressor cells (MDSC expressing CD11b(+/GR-1(+. Moreover, the upregulation of the activated markers CD69, CD44, CD40L, and the downregulation of CD62L were observed in the CD4(+ and CD8(+ T cells following infection. Regulatory T cells expressing CD4(+/CD25(+/FoxP3 (+ increased significantly over the course of infection. CONCLUSIONS: Our findings demonstrate that the microenvironment in the peripheral immune system after E. granulosus infection changes in subtle but detectably ways, especially during the persistent period of infection. We found that T cells were activated following infection, but observed that the significant increase of immunosuppressive cells such as MDSC and Treg cells could inhibit T cell response to E. granulosus antigens. We suggest these cells may play a neglected but key role in the downregulation of the immune response in long-term parasitic infection. Understanding the basic functions

  3. Functional Analysis of Chromosome 18 in Pancreatic Cancer: Strong Evidence for New Tumour Suppressor Genes

    Directory of Open Access Journals (Sweden)

    Liviu P. Lefter

    2004-04-01

    Conclusion: These data represent strong functional evidence that chromosome 18q encodes strong tumour and metastasis suppressor activity that is able to switch human pancreatic cancer cells to a dormant phenotype.

  4. Structure of the Tetrameric p53 Tumor Suppressor Bound to DNA

    National Research Council Canada - National Science Library

    Marmorstein, Ronen

    2002-01-01

    The p53 tumor suppressor binds DNA as a tetramer to regulate the transcription of genes involved in cell cycle arrest and apoptosis, and alterations in the DNA-binding core domain of p53 are the most...

  5. Polysaccharide Agaricus blazei Murill stimulates myeloid derived suppressor cell differentiation from M2 to M1 type, which mediates inhibition of tumour immune-evasion via the Toll-like receptor 2 pathway.

    Science.gov (United States)

    Liu, Yi; Zhang, Lingyun; Zhu, Xiangxiang; Wang, Yuehua; Liu, WenWei; Gong, Wei

    2015-11-01

    Gr-1(+) CD11b(+) myeloid-derived suppressor cells (MDSCs) accumulate in tumor-bearing animals and play a critical negative role during tumor immunotherapy. Strategies for inhibition of MDSCs are expected to improve cancer immunotherapy. Polysaccharide Agaricus blazei Murill (pAbM) has been found to have anti-cancer activity, but the underlying mechanism of this is poorly understood. Here, pAbM directly activated the purified MDSCs through inducing the expression of interleukin-6 (IL-6), IL-12, tumour necrosis factor and inducible nitric oxide synthase (iNOS), CD86, MHC II, and pSTAT1 of it, and only affected natural killer and T cells in the presence of Gr-1(+) CD11b(+) monocytic MDSCs. On further analysis, we demonstrated that pAbM could selectively block the Toll-like receptor 2 (TLR2) signal of Gr-1(+) CD11b(+) MDSCs and increased their M1-type macrophage characteristics, such as producing IL-12, lowering expression of Arginase 1 and increasing expression of iNOS. Extensive study showed that Gr-1(+) CD11b(+) MDSCs by pAbM treatment had less ability to convert the CD4(+) CD25(-) cells into CD4(+) CD25(+) phenotype. Moreover, result from selective depletion of specific cell populations in xenograft mice model suggested that the anti-tumour effect of pAbM was dependent on Gr-1(+ ) CD11b(+) monocytes, nether CD8(+) T cells nor CD4(+) T cells. In addition to, pAbM did not inhibit tumour growth in TLR2(-/-) mice. All together, these results suggested that pAbM, a natural product commonly used for cancer treatment, was a specific TLR2 agonist and had potent anti-tumour effects through the opposite of the suppressive function of Gr-1(+) CD11b(+) MDSCs. © 2015 John Wiley & Sons Ltd.

  6. Deciphering the BRCA1 Tumor Suppressor Network*

    Science.gov (United States)

    Jiang, Qinqin; Greenberg, Roger A.

    2015-01-01

    The BRCA1 tumor suppressor protein is a central constituent of several distinct macromolecular protein complexes that execute homology-directed DNA damage repair and cell cycle checkpoints. Recent years have borne witness to an exciting phase of discovery at the basic molecular level for how this network of DNA repair proteins acts to maintain genome stability and suppress cancer. The clinical dividends of this investment are now being realized with the approval of first-in-class BRCA-targeted therapies for ovarian cancer and identification of molecular events that determine responsiveness to these agents. Further delineation of the basic science underlying BRCA network function holds promise to maximally exploit genome instability for hereditary and sporadic cancer therapy. PMID:26048987

  7. Microbial Regulation of p53 Tumor Suppressor.

    Directory of Open Access Journals (Sweden)

    Alexander I Zaika

    2015-09-01

    Full Text Available p53 tumor suppressor has been identified as a protein interacting with the large T antigen produced by simian vacuolating virus 40 (SV40. Subsequent research on p53 inhibition by SV40 and other tumor viruses has not only helped to gain a better understanding of viral biology, but also shaped our knowledge of human tumorigenesis. Recent studies have found, however, that inhibition of p53 is not strictly in the realm of viruses. Some bacterial pathogens also actively inhibit p53 protein and induce its degradation, resulting in alteration of cellular stress responses. This phenomenon was initially characterized in gastric epithelial cells infected with Helicobacter pylori, a bacterial pathogen that commonly infects the human stomach and is strongly linked to gastric cancer. Besides H. pylori, a number of other bacterial species were recently discovered to inhibit p53. These findings provide novel insights into host-bacteria interactions and tumorigenesis associated with bacterial infections.

  8. Noise suppressor for turbo fan jet engines

    Science.gov (United States)

    Cheng, D. Y. (Inventor)

    1983-01-01

    A noise suppressor is disclosed for installation on the discharge or aft end of a turbo fan engine. Within the suppressor are fixed annular airfoils which are positioned to reduce the relative velocity between the high temperature fast moving jet exhaust and the low temperature slow moving air surrounding it. Within the suppressor nacelle is an exhaust jet nozzle which constrains the shape of the jet exhaust to a substantially uniform elongate shape irrespective of the power setting of the engine. Fixed ring airfoils within the suppressor nacelle therefore have the same salutary effects irrespective of the power setting at which the engine is operated.

  9. Fractionation of T cell subsets on Ig anti-Ig columns: isolation of helper T cells from nonresponder mice, demonstration of antigen-specific T suppressor cells, and selection of CD-3 negative variants of Jurkat T cells

    DEFF Research Database (Denmark)

    Rubin, B; Geisler, C; Kuhlmann, J

    1989-01-01

    In the present experiments we have explored the possibilities of a modified immunoadsorbent technique to select for (1) mutagenized T cell receptor (Tcr) negative variants of Jurkat T lymphoma cells and (2) purified CD-4+ or CD-8+ T lymphocytes. The basic principle was to make large numbers......, and the "autologous" mixed lymphocyte reaction. In addition, the immunoadsorbent method very efficiently selects Tcr/CD-3- variants from mutagenized Jurkat cell populations incubated with anti-CD3 mAb. The described method is easy and quick and can fractionate large numbers of cells; it is the "poor-man's cell sorter...

  10. IL-1 beta-induced chemokine and Fas expression are inhibited by suppressor of cytokine signalling-3 in insulin-producing cells

    DEFF Research Database (Denmark)

    Jacobsen, M.L.B.; Ronn, S.G.; Bruun, C.

    2009-01-01

    -induced Fas and chemokine expression in beta cells. Using a beta cell line with inducible Socs3 expression or primary neonatal rat islet cells transduced with a Socs3-encoding adenovirus, we employed real-time RT-PCR analysis to investigate whether SOCS-3 affects cytokine-induced chemokine and Fas m...

  11. Suppressors made from intermetallic materials

    Science.gov (United States)

    Klett, James W; Muth, Thomas R; Cler, Dan L

    2014-11-04

    Disclosed are several examples of apparatuses for suppressing the blast and flash produced as a projectile is expelled by gases from a firearm. In some examples, gases are diverted away from the central chamber to an expansion chamber by baffles. The gases are absorbed by the expansion chamber and desorbed slowly, thus decreasing pressure and increasing residence time of the gases. In other examples, the gases impinge against a plurality of rods before expanding through passages between the rods to decrease the pressure and increase the residence time of the gases. These and other exemplary suppressors are made from an intermetallic material composition for enhanced strength and oxidation resistance at high operational temperatures.

  12. A pro-inflammatory role for Th22 cells in Helicobacter pylori-associated gastritis.

    Science.gov (United States)

    Zhuang, Yuan; Cheng, Ping; Liu, Xiao-fei; Peng, Liu-sheng; Li, Bo-sheng; Wang, Ting-ting; Chen, Na; Li, Wen-hua; Shi, Yun; Chen, Weisan; Pang, Ken C; Zeng, Ming; Mao, Xu-hu; Yang, Shi-ming; Guo, Hong; Guo, Gang; Liu, Tao; Zuo, Qian-fei; Yang, Hui-jie; Yang, Liu-yang; Mao, Fang-yuan; Lv, Yi-pin; Zou, Quan-ming

    2015-09-01

    Helper T (Th) cell responses are critical for the pathogenesis of Helicobacter pylori-induced gastritis. Th22 cells represent a newly discovered Th cell subset, but their relevance to H. pylori-induced gastritis is unknown. Flow cytometry, real-time PCR and ELISA analyses were performed to examine cell, protein and transcript levels in gastric samples from patients and mice infected with H. pylori. Gastric tissues from interleukin (IL)-22-deficient and wild-type (control) mice were also examined. Tissue inflammation was determined for pro-inflammatory cell infiltration and pro-inflammatory protein production. Gastric epithelial cells and myeloid-derived suppressor cells (MDSC) were isolated, stimulated and/or cultured for Th22 cell function assays. Th22 cells accumulated in gastric mucosa of both patients and mice infected with H. pylori. Th22 cell polarisation was promoted via the production of IL-23 by dendritic cells (DC) during H. pylori infection, and resulted in increased inflammation within the gastric mucosa. This inflammation was characterised by the CXCR2-dependent influx of MDSCs, whose migration was induced via the IL-22-dependent production of CXCL2 by gastric epithelial cells. Under the influence of IL-22, MDSCs, in turn, produced pro-inflammatory proteins, such as S100A8 and S100A9, and suppressed Th1 cell responses, thereby contributing to the development of H. pylori-associated gastritis. This study, therefore, identifies a novel regulatory network involving H. pylori, DCs, Th22 cells, gastric epithelial cells and MDSCs, which collectively exert a pro-inflammatory effect within the gastric microenvironment. Efforts to inhibit this Th22-dependent pathway may therefore prove a valuable strategy in the therapy of H. pylori-associated gastritis. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  13. 15-Deoxy-Δ12,14-prostaglandin J2 activates PI3K-Akt signaling in human breast cancer cells through covalent modification of the tumor suppressor PTEN at cysteine 136.

    Science.gov (United States)

    Suh, Jinyoung; Kim, Do-Hee; Kim, Eun-Hee; Park, Sin-Aye; Park, Jong-Min; Jang, Jeong-Hoon; Kim, Su-Jung; Na, Hye-Kyung; Kim, Nam-Doo; Kim, Nam-Jung; Suh, Young Ger; Surh, Young-Joon

    2018-03-14

    15-Deoxy-Δ 12,14 -prostaglandin J 2 (15d-PGJ 2 ), one of the terminal products of cyclooxygenase-2-catalized arachidonic acid metabolism, has been shown to stimulate breast cancer cell proliferation and migration through Akt activation, but the underlying mechanisms remain poorly understood. In the present study, we investigated the effects of 15d-PGJ 2 on the activity of PTEN, the inhibitor of the phosphoinositide 3-kinase (PI3K)-Akt axis, in human breast cancer (MCF-7) cells. Since the α,β-unsaturated carbonyl moiety in the cyclopentenone ring of 15d-PGJ 2 is electrophilic, we hypothesized that 15d-PGJ 2 -induced Akt phosphorylation might result from the covalent modification and subsequent inactivation of PTEN that has several critical cysteine residues. When treated to MCF-7 cells, 15d-PGJ 2 bound to PTEN, and this was abolished in the presence of the thiol-reducing agent dithiothreitol. A mass spectrometric analysis by using recombinant and endogenous PTEN protein revealed that the cysteine 136 residue (Cys 136 ) of PTEN is covalently modified upon treatment with 15d-PGJ 2 . Notably, the ability of 15d-PGJ 2 to covalently bind to PTEN as well as to induce Akt phosphorylation was abolished in the cells expressing a mutant form of PTEN in which Cys 136 was replaced by serine (C136S-PTEN). The present study demonstrates for the first time that electrophilic 15d-PGJ 2 directly binds to cysteine 136 of PTEN and provides new insight into PTEN loss in cancer progression associated with chronic inflammation. These observations suggest that 15d-PGJ 2 can undergo nucleophilic addition to PTEN, presumably at Cys 136 , thereby inactivating this tumor suppressor protein with concomitant Akt activation. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Allosuppressor and allohelper T cells in acute and chronic graft-vs-host disease. I. Alloreactive suppressor cells rather than killer T cells appear to be the decisive effector cells in lethal graft-vs.-host disease

    NARCIS (Netherlands)

    Rolink, A. G.; Radaszkiewicz, T.; Pals, S. T.; van der Meer, W. G.; Gleichmann, E.

    1982-01-01

    Splenic T cells from B10 donors were injected into irradiated (B10 x DBA/2)F1 mice. Either 5 or 6 d later, activated donor T cells were recovered from the spleens of these primary F1 (1 degree F1) recipients and transferred to groups of nonirradiated syngeneic F1 (2 degrees F1) recipients. Whereas

  15. The von Hippel-Lindau (VHL) tumor-suppressor gene is down-regulated by selenium deficiency in Caco-2 cells and rat colon mucosa

    Science.gov (United States)

    To test the hypothesis that selenium affects DNA methylation and hence gene regulation we employed a methylation array (Panomics) in the human colonic epithelial Caco-2 cell model. The array profiles DNA methylation from promoter regions of 82 human genes. After conditioning cells to repeatedly redu...

  16. MicroRNA-139-5p acts as a tumor suppressor by targeting ELTD1 and regulating cell cycle in glioblastoma multiforme

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Shouping [Department of Diagnostic Imaging, Linyi People' s Hospital, Linyi, Shandong 276000 (China); Wang, Xianjun [Department of Neurology, Linyi People' s Hospital, Linyi, Shandong 276000 (China); Li, Xiao [Department of Pathology, First Affiliated Hospital of Nanjing Medical University, Nanjing (China); Cao, Yuandong, E-mail: yuandongcao@sina.com [Department of Radiotherapy, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province (China)

    2015-11-13

    MicroRNA-139-5p was identified to be significantly down-regulated in glioblastoma multiform (GBM) by miRNA array. In this report we aimed to clarify its biological function, molecular mechanisms and direct target gene in GBM. Twelve patients with GBM were analyzed for the expression of miR-139-5p by quantitative RT-PCR. miR-139-5p overexpression was established by transfecting miR-139-5p-mimic into U87MG and T98G cells, and its effects on cell proliferation were studied using MTT assay and colony formation assays. We concluded that ectopic expression of miR-139-5p in GBM cell lines significantly suppressed cell proliferation and inducing apoptosis. Bioinformatics coupled with luciferase and western blot assays also revealed that miR-139-5p suppresses glioma cell proliferation by targeting ELTD1 and regulating cell cycle. - Highlights: • miR-139-5p is downregulated in GBM. • miR-139-5p regulates cell proliferation through inducing apoptosis. • miR-139-5p regulates glioblastoma tumorigenesis by targeting 3′UTR of ELTD1. • miR-139-5p is involved in cell cycle regulation.

  17. Post-transcriptional modulation of protein phosphatase PPP2CA and tumor suppressor PTEN by endogenous siRNA cleaved from hairpin within PTEN mRNA 3'UTR in human liver cells.

    Science.gov (United States)

    Gao, Yu-En; Wang, Yuan; Chen, Fu-Quan; Feng, Jin-Yan; Yang, Guang; Feng, Guo-Xing; Yang, Zhe; Ye, Li-Hong; Zhang, Xiao-Dong

    2016-07-01

    Increasing evidence shows that mRNAs exert regulatory function along with coding proteins. Recently we report that a hairpin within YAP mRNA 3'UTR can modulate the Hippo signaling pathway. PTEN is a tumor suppressor, and is mutated in human cancers. In this study we examined whether PTEN mRNA 3'UTR contained a hairpin structure that could regulate gene regulation at the post-transcriptional level. The secondary structure of PTEN mRNA 3'UTR was analyzed using RNAdraw and RNAstructure. Function of hairpin structure derived from the PTEN mRNA 3'UTR was examined using luciferase reporter assay, RT-PCR and Western blotting. RNA-immunoprecipitation (RIP) assay was used to analyze the interaction between PTEN mRNA and microprocessor Drosha and DGCR8. Endogenous siRNA (esiRNA) derived from PTEN mRNA 3'UTR was identified by RT-PCR and rt-PCR, and its target genes were predicted using RNAhybrid. A bioinformatics analysis revealed that PTEN mRNA contained a hairpin structure (termed PTEN-sh) within 3'UTR, which markedly increased the reporter activities of AP-1 and NF-κB in 293T cells. Moreover, treatment with PTEN-sh (1 and 2 μg) dose-dependently inhibited the expression of PTEN in human liver L-O2 cells. RIP assay demonstrated that the microprocessor Drosha and DGCR8 was bound to PTEN-sh in L-O2 cells, leading to the cleavage of PTEN-sh from PTEN mRNA 3'UTR. In addition, microprocessor Dicer was involved in the processing of PTEN-sh. Interestingly, esiRNA (termed PTEN-sh-3p21) cleaved from PTEN-sh was identified in 293T cells and human liver tissues, which was found to target the mRNA 3'UTRs of protein phosphatase PPP2CA and PTEN in L-O2 cells. Treatment of L-O2 or Chang liver cells with PTEN-sh-3p21 (50, 100 nmol/L) promoted the cell proliferation in dose- and time-dependent manners. The endogenous siRNA (PTEN-sh-3p21) cleaved from PTEN-sh within PTEN mRNA 3'UTR modulates PPP2CA and PTEN at the post-transcriptional level in liver cells.

  18. Post-transcriptional modulation of protein phosphatase PPP2CA and tumor suppressor PTEN by endogenous siRNA cleaved from hairpin within PTEN mRNA 3′UTR in human liver cells

    Science.gov (United States)

    Gao, Yu-en; Wang, Yuan; Chen, Fu-quan; Feng, Jin-yan; Yang, Guang; Feng, Guo-xing; Yang, Zhe; Ye, Li-hong; Zhang, Xiao-dong

    2016-01-01

    Aim: Increasing evidence shows that mRNAs exert regulatory function along with coding proteins. Recently we report that a hairpin within YAP mRNA 3′UTR can modulate the Hippo signaling pathway. PTEN is a tumor suppressor, and is mutated in human cancers. In this study we examined whether PTEN mRNA 3′UTR contained a hairpin structure that could regulate gene regulation at the post-transcriptional level. Methods: The secondary structure of PTEN mRNA 3′UTR was analyzed using RNAdraw and RNAstructure. Function of hairpin structure derived from the PTEN mRNA 3′UTR was examined using luciferase reporter assay, RT-PCR and Western blotting. RNA-immunoprecipitation (RIP) assay was used to analyze the interaction between PTEN mRNA and microprocessor Drosha and DGCR8. Endogenous siRNA (esiRNA) derived from PTEN mRNA 3′UTR was identified by RT-PCR and rt-PCR, and its target genes were predicted using RNAhybrid. Results: A bioinformatics analysis revealed that PTEN mRNA contained a hairpin structure (termed PTEN-sh) within 3′UTR, which markedly increased the reporter activities of AP-1 and NF-κB in 293T cells. Moreover, treatment with PTEN-sh (1 and 2 μg) dose-dependently inhibited the expression of PTEN in human liver L-O2 cells. RIP assay demonstrated that the microprocessor Drosha and DGCR8 was bound to PTEN-sh in L-O2 cells, leading to the cleavage of PTEN-sh from PTEN mRNA 3′UTR. In addition, microprocessor Dicer was involved in the processing of PTEN-sh. Interestingly, esiRNA (termed PTEN-sh-3p21) cleaved from PTEN-sh was identified in 293T cells and human liver tissues, which was found to target the mRNA 3′UTRs of protein phosphatase PPP2CA and PTEN in L-O2 cells. Treatment of L-O2 or Chang liver cells with PTEN-sh-3p21 (50, 100 nmol/L) promoted the cell proliferation in dose- and time-dependent manners. Conclusion: The endogenous siRNA (PTEN-sh-3p21) cleaved from PTEN-sh within PTEN mRNA 3′UTR modulates PPP2CA and PTEN at the post

  19. CD14+ HLA-DR-/low MDSCs are elevated in the periphery of early-stage breast cancer patients and suppress autologous T cell proliferation.

    Science.gov (United States)

    Speigl, Lisa; Burow, Helen; Bailur, Jithendra Kini; Janssen, Nicole; Walter, Christina-Barbara; Pawelec, Graham; Shipp, Christopher

    2018-04-01

    Despite the recent expansion in the use of immunotherapy for many cancer types, it is still not a standard treatment for breast cancer. Identifying differences in the immune systems of breast cancer patients compared to healthy women might provide insight into potential targets for immunotherapy and thus may assist its clinical implementation. Multi-colour flow cytometry was used to investigate myeloid and lymphoid populations in the peripheral blood of breast cancer patients (n = 40) and in the blood of healthy age-matched women (n = 25). We additionally performed functional testing to identify immune suppressive mechanisms used by circulating CD14+ myeloid cells from breast cancer patients. Our results show that breast cancer patients have significantly elevated frequencies of cells with the monocytic myeloid-derived suppressor cell (mMDSC) phenotype CD14+ HLA-DR-/low compared with healthy women (p < 0.01). We also observed higher levels of earlier differentiated T cells and correspondingly lower levels of T cells in later stages of differentiation (p < 0.05). These disease-associated differences could already be detected in early-stage breast cancer patients in stages 1 and 2 (n = 33 of 40) (p < 0.05). Levels of circulating T cells correlated with certain clinical features and with patient age (p < 0.05). Functional tests showed that CD14+ myeloid cells from breast cancer patients more potently suppressed autologous T cell proliferation than CD14+ cells from healthy women (p < 0.01). Subsequent investigation determined that suppression was mediated in part by reactive oxygen species, because inhibiting this pathway partially restored T cell proliferation (p < 0.01). Our results highlight the potential importance of cells with mMDSC phenotypes in breast cancer, identifiable already at early stages of disease. This may provide a basis for identifying possible new therapeutic targets to enhance anti-cancer immunity.

  20. MiR-424 Promotes Non-Small Cell Lung Cancer Progression and Metastasis through Regulating the Tumor Suppressor Gene TNFAIP1

    Directory of Open Access Journals (Sweden)

    Ming Zhang

    2017-05-01

    Full Text Available Background/Aims: This study aimed to investigate the potential roles of miR-424 expression in non-small cell lung cancer (NSCLC metastasis and growth and its underlying mechanism. Methods: The expression of miR-424 in two NSCLC cell lines (A549 and H1975 was altered by transfection with miR-424 mimic and inhibitor. Effects of miR-424 overexpression and suppression on cells migration, invasion and colony formation were analyzed. Target genes for miR-424 were predicted using bioinformatics method and then verified using luciferase assay. Effects of miR-424 expression on cell migration, invasion and proliferation were reanalyzed on the condition of TNFAIP1 was silenced. Moreover, TNFAIP1 silencing and miR-424 modified A549 cells were subcutaneous injected into node BALB/c mice to confirm the regulation of miR-424 on TNFAIP1 in regulating tumor growth. Results: Compared with the control, miR-424 overexpression significantly increased the migrated and invaded cells, as well as the proliferated colonies. TNFAIP1 was a predicted target gene for miR-424, and was negatively regulated by miR-424. TNFAIP1 silence significantly increased the migrated and invaded cells compared to that in control, while these increases were abolished by miR-424 suppression. Animal experiment further evidenced miR-424 affected tumor growth by regulating TNFAIP1. Conclusions: These data demonstrate that miR-424 may be a contributor for NSCLC progression and metastasis through involving in cell migration, invasion and proliferation via inhibiting TNFAIP1. This study may provide theoretical basis for miR-424 in NSCLC target therapeutic treatment.

  1. MicroRNA-9 functions as a tumor suppressor and enhances radio-sensitivity in radio-resistant A549 cells by targeting neuropilin 1.

    Science.gov (United States)

    Xiong, Kai; Shao, Li Hong; Zhang, Hai Qin; Jin, Linlin; Wei, Wei; Dong, Zhuo; Zhu, Yue Quan; Wu, Ning; Jin, Shun Zi; Xue, Li Xiang

    2018-03-01

    Radiotherapy is commonly used to treat lung cancer but may not kill all cancer cells, which may be attributed to the radiotherapy resistance that often occurs in non-small cell lung cancer (NSCLC). At present, the molecular mechanism of radio-resistance remains unclear. Neuropilin 1 (NRP1), a co-receptor for vascular endothelial growth factor (VEGF), was demonstrated to be associated with radio-resistance of NSCLC cells via the VEGF-phosphoinositide 3-kinase-nuclear factor-κB pathway in our previous study. It was hypothesized that certain microRNAs (miRs) may serve crucial functions in radio-sensitivity by regulating NRP1. Bioinformatics predicted that NRP1 was a potential target of miR-9, and this was validated by luciferase reporter assays. Functionally, miR-9-transfected A549 cells exhibited a decreased proliferation rate, increased apoptosis rate and attenuated migratory and invasive abilities. Additionally, a high expression of miR-9 also significantly enhanced the radio-sensitivity of A549 cells in vitro and in vivo . These data improve understanding of the mechanisms of cell radio-resistance, and suggest that miR-9 may be a molecular target for the prediction of radio-sensitivity in NSCLC.

  2. Hypomethylation of tumor suppressor genes in odontogenic myxoma

    OpenAIRE

    Moreira,Paula Rocha; Cardoso,Fabiano Pereira; Brito,João Artur Ricieri; Batista,Aline Carvalho; Gomes,Carolina Cavaliéri; Gomez,Ricardo Santiago

    2011-01-01

    Odontogenic myxoma (OM) is an ectomesenchymal benign odontogenic tumor characterized by spindle or stellate-shaped cells embedded in an abundant myxoid or mucoid extracellular matrix. DNA methylation is characterized by the addition of methyl groups in cytosines within CpG islands in the promoter gene. DNA methylation can decrease the expression of tumor suppressor genes and contribute to the development of neoplastic lesions. The aim of study was to evaluate the methylation pattern of the tu...

  3. Von Hippel-Lindau tumor suppressor gene loss in renal cell carcinoma promotes oncogenic epidermal growth factor receptor signaling via Akt-1 and MEK-1.

    Science.gov (United States)

    Lee, S Justin; Lattouf, Jean-Baptiste; Xanthopoulos, Julie; Linehan, W Marston; Bottaro, Donald P; Vasselli, James R

    2008-10-01

    Clear-cell renal cell carcinoma (RCC) is the most prevalent form of kidney cancer and is frequently associated with loss of von Hippel-Lindau (VHL) gene function, resulting in the aberrant transcriptional activation of genes that contribute to tumor growth and metastasis, including transforming growth factor-alpha (TGF-alpha), a ligand of the epidermal growth factor receptor (EGFR) tyrosine kinase. To determine the functional impact of EGFR activation on RCC, we suppressed critical components of this pathway: EGFR, Akt-1, and MEK-1. Stable transfection of RCC cells with plasmids bearing shRNA directed against each of these genes was used to individually suppress their expression. Transfectants were characterized for growth and invasiveness in vitro and tumorigenesis in vivo. RCC cell transfectants displayed significantly reduced growth rate and matrix invasion in vitro and RCC tumor xenograft growth rate in vivo. Analysis of tumor cells that emerged after extended periods in each model showed that significant EGFR suppression was sustained, whereas Akt-1 and MEK-1 knock-down cells had escaped shRNA suppression. EGFR, Akt-1, and MEK-1 are individually critical for RCC cell invasiveness in vitro and tumorigenicity in vivo, and even partial suppression of each can have a significant impact on tumor progression. The emergence of transfectants that had escaped Akt-1 and MEK-1 suppression during tumorigenicity experiments suggests that these effectors may each be more critical than EGFR for RCC tumorigenesis, consistent with results from clinical trials of EGFR inhibitors for RCC, where durable clinical responses have not been seen.

  4. Von Hippel-Lindau Tumor Suppressor Gene Loss in Renal Cell Carcinoma Promotes Oncogenic Epidermal Growth Factor Receptor Signaling via Akt-1 and MEK1

    Science.gov (United States)

    Lee, S. Justin; Lattouf, Jean-Baptiste; Xanthopoulos, Julie; Linehan, W. Marston; Bottaro, Donald P.; Vasselli, James R.

    2008-01-01

    Objectives Clear-cell renal cell carcinoma (RCC) is the most prevalent form of kidney cancer and is frequently associated with loss of von Hippel-Lindau (VHL) gene function, resulting in the aberrant transcriptional activation of genes that contribute to tumor growth and metastasis, including transforming growth factor-α (TGF-α), a ligand of the epidermal growth factor receptor (EGFR) tyrosine kinase. To determine the functional impact of EGFR activation on RCC, we suppressed critical components of this pathway: EGFR, Akt-1, and MEK-1. Methods Stable transfection of RCC cells with plasmids bearing shRNA directed against each of these genes was used to individually suppress their expression. Transfectants were characterized for growth and invasiveness in vitro and tumorigenesis in vivo. Results RCC cell transfectants displayed significantly reduced growth rate and matrix invasion in vitro and RCC tumor xenograft growth rate in vivo. Analysis of tumor cells that emerged after extended periods in each model showed that significant EGFR suppression was sustained, whereas Akt-1 and MEK-1 knockdown cells had escaped shRNA suppression. Conclusions EGFR, Akt-1, and MEK-1 are individually critical for RCC cell invasiveness in vitro and tumorigenicity in vivo, and even partial suppression of each can have a significant impact on tumor progression. The emergence of transfectants that had escaped Akt-1 and MEK-1 suppression during tumorigenicity experiments suggests that these effectors may each be more critical than EGFR for RCC tumorigenesis, consistent with results from clinical trials of EGFR inhibitors for RCC, where durable clinical responses have not been seen. PMID:18243508

  5. Gelsolin negatively regulates the activity of tumor suppressor p53 through their physical interaction in hepatocarcinoma HepG2 cells

    Energy Technology Data Exchange (ETDEWEB)

    An, Joo-Hee; Kim, Jung-Woong; Jang, Sang-Min; Kim, Chul-Hong; Kang, Eun-Jin; Choi, Kyung-Hee, E-mail: khchoi@cau.ac.kr

    2011-08-19

    Highlights: {yields} The actin binding protein Gelsolin (GSN) interacts with transcription factor p53. {yields} GSN interacts with transactivation- and DNA binding domains of p53. {yields} GSN represses transactivity of p53 via inhibition of nuclear translocation of p53. {yields} GSN inhibits the p53-mediated apoptosis in hepatocarcinoma HepG2 cells. -- Abstract: As a transcription factor, p53 modulates several cellular responses including cell-cycle control, apoptosis, and differentiation. In this study, we have shown that an actin regulatory protein, gelsolin (GSN), can physically interact with p53. The nuclear localization of p53 is inhibited by GSN overexpression in hepatocarcinoma HepG2 cells. Additionally, we demonstrate that GSN negatively regulates p53-dependent transcriptional activity of a reporter construct, driven by the p21-promoter. Furthermore, p53-mediated apoptosis was repressed in GSN-transfected HepG2 cells. Taken together, these results suggest that GSN binds to p53 and this interaction leads to the inhibition of p53-induced apoptosis by anchoring of p53 in the cytoplasm in HepG2 cells.

  6. The splicing mutant of the human tumor suppressor protein DFNA5 induces programmed cell death when expressed in the yeast Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Sofie eVan Rossom

    2012-07-01

    Full Text Available DFNA5 was first identified as a gene responsible for autosomal dominant deafness. Different mutations were found, but they all resulted in exon 8 skipping during splicing and premature termination of the protein. Later, it became clear that the protein also has a tumor suppression function and that it can induce apoptosis. Epigenetic silencing of the DFNA5 gene is associated with different types of cancers, including gastric and colorectal cancers as well as breast tumors. We introduced the wild-type and mutant DFNA5 allele in the yeast Saccharomyces cerevisiae. The expression of the wild-type protein was well tolerated by the yeast cells, although the protein was subject of degradation and often deposited in distinct foci when cells entered the diauxic shift. In contrast, cells had problems to cope with mutant DFNA5 and despite an apparent compensatory reduction in expression levels, the mutant protein still triggered a marked growth defect, which in part can be ascribed to its interaction with mitochondria. Consistently, cells with mutant DFNA5 displayed significantly increased levels of ROS and signs of programmed cell death. The latter occurred independently of the yeast caspase, Mca1, but involved the mitochondrial fission protein, Fis1, the voltage-dependent anion channel protein, Por1 and the mitochondrial adenine-nucleotide translocators, Aac1 and Aac3. Recent data proposed DFNA5 toxicity to be associated to a globular domain encoded by exon 2 to 6. We confirmed these data by showing that expression of solely this domain confers a strong growth phenotype. In addition, we identified a point mutant in this domain that completely abrogated its cytotoxicity in yeast as well as human HEK293T cells. Combined, our data underscore that the yeast system offers a valuable tool to further dissect the apoptotic properties of DFNA5.

  7. MicroRNA-193b-3p acts as a tumor suppressor by targeting the MYB oncogene in T-cell acute lymphoblastic leukemia

    OpenAIRE

    Mets, E; Van der Meulen, J; Van Peer, G; Boice, M; Mestdagh, P; Van de Walle, I; Lammens, T; Goossens, S; De Moerloose, B; Benoit, Y; Van Roy, N; Clappier, E; Poppe, B; Vandesompele, J; Wendel, H-G

    2014-01-01

    The MYB oncogene is a leucine zipper transcription factor essential for normal and malignant hematopoiesis. In T-cell acute lymphoblastic leukemia (T-ALL), elevated MYB levels can arise directly through T-cell receptor-mediated MYB translocations, genomic MYB duplications or enhanced TAL1 complex binding at the MYB locus or indirectly through the TAL1/miR-223/FBXW7 regulatory axis. In this study, we used an unbiased MYB 3′untranslated region–microRNA (miRNA) library screen and identified 33 p...

  8. Tumor suppressors BTG1 and IKZF1 cooperate during mouse leukemia development and increase relapse risk in B-cell precursor acute lymphoblastic leukemia patients

    NARCIS (Netherlands)

    Scheijen, B.; Boer, J.M.A.; Marke, R.; Tijchon, E.J.; Ingen Schenau, D.S. van; Waanders, E.; Emst, L. van; Meer, L.T. van der; Pieters, R.; Escherich, G.; Horstmann, M.A.; Sonneveld, E.; Venn, N.; Sutton, R.; Dalla-Pozza, L.; Kuiper, R.P.; Hoogerbrugge, P.M.; Boer, M.L. Den; Leeuwen, F.N. van

    2017-01-01

    Deletions and mutations affecting lymphoid transcription factor IKZF1 (IKAROS) are associated with an increased relapse risk and poor outcome in B-cell precursor acute lymphoblastic leukemia. However, additional genetic events may either enhance or negate the effects of IKZF1 deletions on prognosis.

  9. Bax Inhibitor-1, a conserved cell death suppressor, is a key molecular switch downstream from a variety of biotic and abiotic stress signals in plants.

    Science.gov (United States)

    Watanabe, Naohide; Lam, Eric

    2009-07-10

    In Nature plants are constantly challenged by a variety of environmental stresses that could lead to disruptions in cellular homeostasis. Programmed cell death (PCD) is a fundamental cellular process that is often associated with defense responses to pathogens, during development and in response to abiotic stresses in fungi, animals and plants. Although there are many characteristics shared between different types of PCD events, it remains unknown whether a common mechanism drives various types of PCD in eukaryotes. One candidate regulator for such a mechanism is Bax Inhibitor-1 (BI-1), an evolutionary conserved, endoplasmic reticulum (ER)-resident protein that represents an ancient cell death regulator that potentially regulates PCD in all eukaryotes. Recent findings strongly suggested that BI-1 plays an important role in the conserved ER stress response pathway to modulate cell death induction in response to multiple types of cell death signals. As ER stress signaling pathways has been suggested to play important roles not only in the control of ER homeostasis but also in other biological processes such as the response to pathogens and abiotic stress in plants, BI-1 might function to control the convergence point that modulates the level of the "pro-survival and pro-death" signals under multiple stress conditions.

  10. Cell-cycle and suppressor proteins expression in uterine cervix in HIV/HPV co-infection: comparative study by tissue micro-array (TMA)

    International Nuclear Information System (INIS)

    Nicol, Alcina F; Pirmez, Claude; Pires, Andréa Rodrigues Cordovil; Souza, Simone R de; Nuovo, Gerard J; Grinsztejn, Beatriz; Tristão, Aparecida; Russomano, Fabio B; Velasque, Luciane; Silva, José R Lapa e

    2008-01-01

    The oncoproteins of human papillomavirus (HPVs) directly effect cell-cycle control. We hypothesize that regulatory and cell cycle protein expression might be additionally modified in the cervix of HIV/HPV co-infected women. We analyzed the expression of Rb, p27, VEGF and Elf-1 transcriptor factor by immunohistochemistry in 163 paraffin-embeded cervical samples using Tissue Micro-Array (TMA) and correlated this to HIV-1 and HPV infection. HIV/HPV co-infection was associated with a significant increase in expression (p < 0.001) of VEGF and p27 in both low and high grade CIN when compared to the cervices of women infected by HPV alone. Decreased Rb expression was evident with increased CIN grade in the cervices of women infected with HPV alone (p = 0.003 average of cells/mm 2 in CIN I: 17.9, CIN II/III: 4.8, and tumor 3.9). Rb expression increased 3-fold for both low and high grade CIN with HPV/HIV-1 co-infection compared to HPV infection alone but did not reach statistical significance. There was a significant increase in Elf-1 expression in HPV+/HIV- women with CIN II/III and tumor (average of cells/mm 2 in CIN I: 63.8; CIN II/III: 115.7 and tumor: 112.0, p = 0.005), in comparison to controls. Co-infection of HPV and HIV leads to significant increase in the VEGF and p27 expression when compared to HPV+/HIV-negative infection that could facilitate viral persistence and invasive tumor development

  11. Cell-cycle and suppressor proteins expression in uterine cervix in HIV/HPV co-infection: comparative study by tissue micro-array (TMA).

    Science.gov (United States)

    Nicol, Alcina F; Pires, Andréa Rodrigues Cordovil; de Souza, Simone R; Nuovo, Gerard J; Grinsztejn, Beatriz; Tristão, Aparecida; Russomano, Fabio B; Velasque, Luciane; Lapa e Silva, José R; Pirmez, Claude

    2008-10-07

    The oncoproteins of human papillomavirus (HPVs) directly effect cell-cycle control. We hypothesize that regulatory and cell cycle protein expression might be additionally modified in the cervix of HIV/HPV co-infected women. We analyzed the expression of Rb, p27, VEGF and Elf-1 transcriptor factor by immunohistochemistry in 163 paraffin-embeded cervical samples using Tissue Micro-Array (TMA) and correlated this to HIV-1 and HPV infection. HIV/HPV co-infection was associated with a significant increase in expression (p < 0.001) of VEGF and p27 in both low and high grade CIN when compared to the cervices of women infected by HPV alone. Decreased Rb expression was evident with increased CIN grade in the cervices of women infected with HPV alone (p = 0.003 average of cells/mm2 in CIN I: 17.9, CIN II/III: 4.8, and tumor 3.9). Rb expression increased 3-fold for both low and high grade CIN with HPV/HIV-1 co-infection compared to HPV infection alone but did not reach statistical significance. There was a significant increase in Elf-1 expression in HPV+/HIV- women with CIN II/III and tumor (average of cells/mm2 in CIN I: 63.8; CIN II/III: 115.7 and tumor: 112.0, p = 0.005), in comparison to controls. Co-infection of HPV and HIV leads to significant increase in the VEGF and p27 expression when compared to HPV+/HIV-negative infection that could facilitate viral persistence and invasive tumor development.

  12. Invasion suppressor cystatin E/M (CST6): High-level cell type-specific expression in normal brain and epigenetic silencing in gliomas

    Science.gov (United States)

    Qiu, Jingxin; Ai, Lingbao; Ramachandran, Cheppail; Yao, Bing; Gopalakrishnan, Suhasni; Fields, C. Robert; Delmas, Amber L.; Dyer, Lisa M.; Melnick, Steven J.; Yachnis, Anthony T.; Schwartz, Philip H.; Fine, Howard A.; Brown, Kevin D.; Robertson, Keith D.

    2008-01-01

    DNA hypermethylation mediated gene silencing is a frequent and early contributor to aberrant cell growth and invasion in cancer. Malignant gliomas are the most common primary brain tumors in adults and the second most common tumor in children. Morbidity and mortality are high in glioma patients because tumors are resistant to treatment and are highly invasive into surrounding brain tissue rendering complete surgical resection impossible. Invasiveness is regulated by the interplay between secreted proteases (e.g. cathepsins) and their endogenous inhibitors (cystatins). In our previous studies we identified cystatin E/M (CST6) as a frequent target of epigenetic silencing in glioma. Cystatin E/M is a potent inhibitor of cathepsin B, which is frequently over-expressed in glioma. Here we study the expression of cystatin E/M in normal brain and show that it is highly and moderately expressed in oligodendrocytes and astrocytes, respectively, but not in neurons. Consistent with this, the CST6 promoter is hypomethylated in all normal samples using methylation specific PCR, bisulfite genomic sequencing, and pyrosequencing. In contrast, 78% of 28 primary brain tumors demonstrated reduced/absent cystatin E/M expression using a tissue microarray and this reduced expression correlated with CST6 promoter hypermethylation. Interestingly, CST6 was expressed in neural stem cells (NSC) and markedly induced upon differentiation, while a glioma tumor initiating cell (TIC) line was completely blocked for CST6 expression by promoter methylation. Analysis of primary pediatric brain tumor-derived lines also showed CST6 downregulation and methylation in nearly 100% of 12 cases. Finally, ectopic expression of cystatin E/M in glioma lines reduced cell motility and invasion. These results demonstrate that epigenetic silencing of CST6 is frequent in adult and pediatric brain tumors and occurs in TICs, which are thought to give rise to the tumor. CST6 methylation may therefore represent a novel

  13. Cell-cycle and suppressor proteins expression in uterine cervix in HIV/HPV co-infection: comparative study by tissue micro-array (TMA

    Directory of Open Access Journals (Sweden)

    Russomano Fabio B

    2008-10-01

    Full Text Available Abstract Background The oncoproteins of human papillomavirus (HPVs directly effect cell-cycle control. We hypothesize that regulatory and cell cycle protein expression might be additionally modified in the cervix of HIV/HPV co-infected women. Methods We analyzed the expression of Rb, p27, VEGF and Elf-1 transcriptor factor by immunohistochemistry in 163 paraffin-embeded cervical samples using Tissue Micro-Array (TMA and correlated this to HIV-1 and HPV infection. Results HIV/HPV co-infection was associated with a significant increase in expression (p 2 in CIN I: 17.9, CIN II/III: 4.8, and tumor 3.9. Rb expression increased 3-fold for both low and high grade CIN with HPV/HIV-1 co-infection compared to HPV infection alone but did not reach statistical significance. There was a significant increase in Elf-1 expression in HPV+/HIV- women with CIN II/III and tumor (average of cells/mm2 in CIN I: 63.8; CIN II/III: 115.7 and tumor: 112.0, p = 0.005, in comparison to controls. Conclusion Co-infection of HPV and HIV leads to significant increase in the VEGF and p27 expression when compared to HPV+/HIV-negative infection that could facilitate viral persistence and invasive tumor development.

  14. Extravirgin olive oil up-regulates CB₁ tumor suppressor gene in human colon cancer cells and in rat colon via epigenetic mechanisms.

    Science.gov (United States)

    Di Francesco, Andrea; Falconi, Anastasia; Di Germanio, Clara; Micioni Di Bonaventura, Maria Vittoria; Costa, Antonio; Caramuta, Stefano; Del Carlo, Michele; Compagnone, Dario; Dainese, Enrico; Cifani, Carlo; Maccarrone, Mauro; D'Addario, Claudio

    2015-03-01

    Extravirgin olive oil (EVOO) represents the typical lipid source of the Mediterranean diet, an eating habit pattern that has been associated with a significant reduction of cancer risk. Diet is the more studied environmental factor in epigenetics, and many evidences suggest dysregulation of epigenetic pathways in cancer. The aim of our study was to investigate the effects of EVOO and its phenolic compounds on endocannabinoid system (ECS) gene expression via epigenetic regulation in both human colon cancer cells (Caco-2) and rats exposed to short- and long-term dietary EVOO. We observed a selective and transient up-regulation of CNR1 gene - encoding for type 1 cannabinoid receptor (CB₁) - that was evoked by exposure of Caco-2 cells to EVOO (100 ppm), its phenolic extracts (OPE, 50 μM) or authentic hydroxytyrosol (HT, 50 μM) for 24 h. None of the other major elements of the ECS (i.e., CB₂; GPR55 and TRPV1 receptors; and NAPE-PLD, DAGL, FAAH and MAGL enzymes) was affected at any time point. The stimulatory effect of OPE and HT on CB₁ expression was inversely correlated to DNA methylation at CNR1 promoter and was associated with reduced proliferation of Caco-2 cells. Interestingly, CNR1 gene was less expressed in Caco-2 cells when compared to normal colon mucosa cells, and again this effect was associated with higher level of DNA methylation at CNR1. Moreover, in agreement with the in vitro studies, we also observed a remarkable (~4-fold) and selective increase in CB₁ expression in the colon of rats receiving dietary EVOO supplementation for 10 days. Consistently, CpG methylation of rat Cnr1 promoter, miR23a and miR-301a, previously shown to be involved in the pathogenesis of colorectal cancer and predicted to target CB₁ mRNA, was reduced after EVOO administration down to ~50% of controls. Taken together, our findings demonstrating CB₁ gene expression modulation by EVOO or its phenolic compounds via epigenetic mechanism, both in vitro and in vivo, may

  15. The TAL1 complex targets the FBXW7 tumor suppressor by activating miR-223 in human T cell acute lymphoblastic leukemia

    OpenAIRE

    Mansour, Marc R.; Sanda, Takaomi; Lawton, Lee N.; Li, Xiaoyu; Kreslavsky, Taras; Novina, Carl D.; Brand, Marjorie; Gutierrez, Alejandro; Kelliher, Michelle A.; Jamieson, Catriona H.M.; von Boehmer, Harald; Young, Richard A.; Look, A. Thomas

    2013-01-01

    The oncogenic transcription factor TAL1/SCL is aberrantly expressed in 60% of cases of human T cell acute lymphoblastic leukemia (T-ALL) and initiates T-ALL in mouse models. By performing global microRNA (miRNA) expression profiling after depletion of TAL1, together with genome-wide analysis of TAL1 occupancy by chromatin immunoprecipitation coupled to massively parallel DNA sequencing, we identified the miRNA genes directly controlled by TAL1 and its regulatory partners HEB, E2A, LMO1/2, GAT...

  16. Phosphorylation-regulated degradation of the tumor-suppressor form of PED by chaperone-mediated autophagy in lung cancer cells.

    Science.gov (United States)

    Quintavalle, Cristina; Di Costanzo, Stefania; Zanca, Ciro; Tasset, Immaculada; Fraldi, Alessandro; Incoronato, Mariarosaria; Mirabelli, Peppino; Monti, Maria; Ballabio, Andrea; Pucci, Piero; Cuervo, Ana Maria; Condorelli, Gerolama

    2014-10-01

    PED/PEA-15 is a death effector domain (DED) family member with a variety of effects on cell growth and metabolism. To get further insight into the role of PED in cancer, we aimed to find new PED interactors. Using tandem affinity purification, we identified HSC70 (Heat Shock Cognate Protein of 70 kDa)-which, among other processes, is involved in chaperone-mediated autophagy (CMA)-as a PED-interacting protein. We found that PED has two CMA-like motifs (i.e., KFERQ), one of which is located within a phosphorylation site, and demonstrate that PED is a bona fide CMA substrate and the first example in which phosphorylation modifies the ability of HSC70 to access KFERQ-like motifs and target the protein for lysosomal degradation. Phosphorylation of PED switches its function from tumor suppression to tumor promotion, and we show that HSC70 preferentially targets the unphosphorylated form of PED to CMA. Therefore, we propose that the up-regulated CMA activity characteristic of most types of cancer cell enhances oncogenesis by shifting the balance of PED function toward tumor promotion. This mechanism is consistent with the notion of a therapeutic potential for targeting CMA in cancer, as inhibition of this autophagic pathway may help restore a physiological ratio of PED forms. © 2014 Wiley Periodicals, Inc.

  17. Genomic Analyses Reveal Global Functional Alterations That Promote Tumor Growth and Novel Tumor Suppressor Genes in Natural Killer-Cell Malignancies

    DEFF Research Database (Denmark)

    Kucuk, Can; Iqbal, Javeed; J. deLeeuw, Ronald

    in the gene expression profile, we performed GEP and array-CGH studies on seven clinically well defined cases and eight well characterized cell lines derived from NKL patients. Methods: Array-CGH was performed on a tiling BAC array and GEP on an Affymetrix 133 plus2 array.The two data sets were correlated...... to identify functional alterations associated with the genetic abnormalities.Candidate genes on del 6q21 were identified and further studied for mutations and promoter methylation. Results: Our aCGH study identified frequent recurrent gains (> 25 %) in 1q, 2p, 7q, 13q, 17q and 20pter-qter. Regions of loss...

  18. MicroRNA-31 functions as an oncogenic microRNA in mouse and human lung cancer cells by repressing specific tumor suppressors

    DEFF Research Database (Denmark)

    Liu, Xi; Sempere, Lorenzo F; Ouyang, Haoxu

    2010-01-01

    MicroRNAs (miRNAs) regulate gene expression. It has been suggested that obtaining miRNA expression profiles can improve classification, diagnostic, and prognostic information in oncology. Here, we sought to comprehensively identify the miRNAs that are overexpressed in lung cancer by conducting mi......RNA microarray expression profiling on normal lung versus adjacent lung cancers from transgenic mice. We found that miR-136, miR-376a, and miR-31 were each prominently overexpressed in murine lung cancers. Real-time RT-PCR and in situ hybridization (ISH) assays confirmed these miRNA expression profiles in paired...... normal-malignant lung tissues from mice and humans. Engineered knockdown of miR-31, but not other highlighted miRNAs, substantially repressed lung cancer cell growth and tumorigenicity in a dose-dependent manner. Using a bioinformatics approach, we identified miR-31 target mRNAs and independently...

  19. Using yeast to determine the functional consequences of mutations in the human p53 tumor suppressor gene: An introductory course-based undergraduate research experience in molecular and cell biology.

    Science.gov (United States)

    Hekmat-Scafe, Daria S; Brownell, Sara E; Seawell, Patricia Chandler; Malladi, Shyamala; Imam, Jamie F Conklin; Singla, Veena; Bradon, Nicole; Cyert, Martha S; Stearns, Tim

    2017-03-04

    The opportunity to engage in scientific research is an important, but often neglected, component of undergraduate training in biology. We describe the curriculum for an innovative, course-based undergraduate research experience (CURE) appropriate for a large, introductory cell and molecular biology laboratory class that leverages students' high level of interest in cancer. The course is highly collaborative and emphasizes the analysis and interpretation of original scientific data. During the course, students work in teams to characterize a collection of mutations in the human p53 tumor suppressor gene via expression and analysis in yeast. Initially, student pairs use both qualitative and quantitative assays to assess the ability of their p53 mutant to activate expression of reporter genes, and they localize their mutation within the p53 structure. Through facilitated discussion, students suggest possible molecular explanations for the transactivation defects displayed by their p53 mutants and propose experiments to test these hypotheses that they execute during the second part of the course. They use a western blot to determine whether mutant p53 levels are reduced, a DNA-binding assay to test whether recognition of any of three p53 target sequences is compromised, and fluorescence microscopy to assay nuclear localization. Students studying the same p53 mutant periodically convene to discuss and interpret their combined data. The course culminates in a poster session during which students present their findings to peers, instructors, and the greater biosciences community. Based on our experience, we provide recommendations for the development of similar large introductory lab courses. © 2016 by The International Union of Biochemistry and Molecular Biology, 45(2):161-178, 2017. © 2016 The International Union of Biochemistry and Molecular Biology.

  20. Increased level of both CD4+FOXP3+ regulatory T cells and CD14+HLA-DR⁻/low myeloid-derived suppressor cells and decreased level of dendritic cells in patients with multiple myeloma

    DEFF Research Database (Denmark)

    Brimnes, Marie Klinge; Vangsted, Annette Juul; Meldgaard Knudsen, Lene

    2010-01-01

    +FOXP3+ Treg cells was increased in patients at diagnosis and not in patients in remission or with MGUS. Also, Treg cells from patients with MM were functionally intact as they were able to inhibit proliferation of both CD4 and CD8 T cells. Finally, we observed an increase in the proportion of CD14+HLA...

  1. Effects of sildenafil and/or muscle derived stem cells on myocardial infarction

    Directory of Open Access Journals (Sweden)

    Wang Judy SC

    2012-08-01

    Full Text Available Abstract Background Previous studies have shown that long-term oral daily PDE 5 inhibitors (PDE5i counteract fibrosis, cell loss, and the resulting dysfunction in tissues of various rat organs and that implantation of skeletal muscle-derived stem cells (MDSC exerts some of these effects. PDE5i and stem cells in combination were found to be more effective in non-MI cardiac repair than each treatment separately. We have now investigated whether sildenafil at lower doses and MDSC, alone or in combination are effective to attenuate LV remodeling after MI in rats. Methods MI was induced in rats by ligature of the left anterior descending coronary artery. Treatment groups were: “Series A”: 1 untreated; 2 oral sildenafil 3 mg/kg/day from day 1; and “Series B”: intracardiac injection at day 7 of: 3 saline; 4 rat MDSC (106 cells; 5 as #4, with sildenafil as in #2. Before surgery, and at 1 and 4 weeks, the left ventricle ejection fraction (LVEF was measured. LV sections were stained for collagen, myofibroblasts, apoptosis, cardiomyocytes, and iNOS, followed by quantitative image analysis. Western blots estimated angiogenesis and myofibroblast accumulation, as well as potential sildenafil tachyphylaxis by PDE 5 expression. Zymography estimated MMPs 2 and 9 in serum. Results As compared to untreated MI rats, sildenafil improved LVEF, reduced collagen, myofibroblasts, and circulating MMPs, and increased cardiac troponin T. MDSC replicated most of these effects and stimulated cardiac angiogenesis. Concurrent MDSC/sildenafil counteracted cardiomyocyte and endothelial cells loss, but did not improve LVEF or angiogenesis, and upregulated PDE 5. Conclusions Long-term oral sildenafil, or MDSC given separately, reduce the MI fibrotic scar and improve left ventricular function in this rat model. The failure of the treatment combination may be due to inducing overexpression of PDE5.

  2. Molecular biology III - Oncogenes and tumor suppressor genes

    International Nuclear Information System (INIS)

    Giaccia, Amato J.

    1996-01-01

    Purpose: The purpose of this course is to introduce to radiation oncologists the basic concepts of tumorigenesis, building on the information that will be presented in the first and second part of this series of lectures. Objective: Our objective is to increase the current understanding of radiation oncologists with the process of tumorigenesis, especially focusing on genes that are altered in many tumor types that are potential candidates for novel molecular strategies. As strategies to treat cancer of cancer are becoming more sophisticated, it will be important for both the practitioner and academician to develop a basic understanding of the function of cancer 'genes'. This will be the third in a series of refresher courses that are meant to address recent advances in Cancer Biology in a way that both clinicians without previous knowledge of molecular biology or experienced researchers will find interesting. The lecture will begin with a basic overview of tumorigenesis; methods of detecting chromosome/DNA alterations, approaches used to isolate oncogenes and tumor suppressor genes, and their role in cell killing by apoptosis. Special attention will be given to oncogenes and tumor suppressor genes that are modulated by ionizing radiation and the tumor microenvironment. We will relate the biology of oncogenes and tumor suppressor genes to basic aspects of radiation biology that would be important in clinical practice. Finally, we will review recent studies on the prognostic significance of p53 mutations and apoptosis in tumor specimens. The main point of this lecture is to relate both researcher and clinician what are the therapeutic ramifications of oncogene and tumor suppressor gene mutations found in human neoptasia

  3. TFPI-2 is a putative tumor suppressor gene frequently inactivated by promoter hypermethylation in nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Wang, Shumin; Ma, Ning; Murata, Mariko; Huang, Guangwu; Zhang, Zhe; Xiao, Xue; Zhou, Xiaoying; Huang, Tingting; Du, Chunping; Yu, Nana; Mo, Yingxi; Lin, Longde; Zhang, Jinyan

    2010-01-01

    Epigenetic silencing of tumor suppressor genes play important roles in NPC tumorgenesis. Tissue factor pathway inhibitor-2 (TFPI-2), is a protease inhibitor. Recently, TFPI-2 was suggested to be a tumor suppressor gene involved in tumorigenesis and metastasis in some cancers. In this study, we investigated whether TFPI-2 was inactivated epigenetically in nasopharyngeal carcinoma (NPC). Transcriptional expression levels of TFPI-2 was evaluated by RT-PCR. Methylation status were investigated by methylation specific PCR and bisulfate genomic sequencing. The role of TFPI-2 as a tumor suppressor gene in NPC was addressed by re-introducing TFPI-2 expression into the NPC cell line CNE2. TFPI-2 mRNA transcription was inactivated in NPC cell lines. TFPI-2 was aberrantly methylated in 66.7% (4/6) NPC cell lines and 88.6% (62/70) of NPC primary tumors, but not in normal nasopharyngeal epithelia. TFPI-2 expression could be restored in NPC cells after demethylation treatment. Ectopic expression of TFPI-2 in NPC cells induced apoptosis and inhibited cell proliferation, colony formation and cell migration. Epigenetic inactivation of TFPI-2 by promoter hypermethylation is a frequent and tumor specific event in NPC. TFPI-2 might be considering as a putative tumor suppressor gene in NPC

  4. Effect of duct shape, Mach number, and lining construction on measured suppressor attenuation and comparison with theory

    Science.gov (United States)

    Olsen, W. A.; Krejsa, E. A.; Coats, J. W.

    1972-01-01

    Noise attenuation was measured for several types of cylindrical suppressors that use a duct lining composed of honeycomb cells covered with a perforated plate. The experimental technique used gave attenuation data that were repeatable and free of noise floors and other sources of error. The suppressor length, the effective acoustic diameter, suppressor shape and flow velocity were varied. The agreement among the attenuation data and two widely used analytical models was generally satisfactory. Changes were also made in the construction of the acoustic lining to measure their effect on attenuation. One of these produced a very broadband muffler.

  5. Modulator of Apoptosis 1 (MOAP-1) Is a Tumor Suppressor Protein Linked to the RASSF1A Protein*

    OpenAIRE

    Law, Jennifer; Salla, Mohamed; Zare, Alaa; Wong, Yoke; Luong, Le; Volodko, Natalia; Svystun, Orysya; Flood, Kayla; Lim, Jonathan; Sung, Miranda; Dyck, Jason R. B.; Tan, Chong Teik; Su, Yu-Chin; Yu, Victor C.; Mackey, John

    2015-01-01

    Modulator of apoptosis 1 (MOAP-1) is a BH3-like protein that plays key roles in cell death or apoptosis. It is an integral partner to the tumor suppressor protein, Ras association domain family 1A (RASSF1A), and functions to activate the Bcl-2 family pro-apoptotic protein Bax. Although RASSF1A is now considered a bona fide tumor suppressor protein, the role of MOAP-1 as a tumor suppressor protein has yet to be determined. In this study, we present several lines of evidence from cancer databas...

  6. Tumor suppressor identified as inhibitor of inflammation

    Science.gov (United States)

    Scientists at NCI have found that a protein, FBXW7, which acts as a tumor suppressor, is also important for the reduction in strength of inflammatory pathways. It has long been recognized that a complex interaction exists between cancer causing mechanisms

  7. RNAi suppressors encoded by pathogenic human viruses

    NARCIS (Netherlands)

    de Vries, Walter; Berkhout, Ben

    2008-01-01

    RNA silencing or RNAi interference (RNAi) serves as an innate antiviral mechanism in plants, fungi and animals. Human viruses, like plant viruses, encode suppressor proteins or RNAs that block or modulate the RNAi pathway. This review summarizes the mechanisms by which pathogenic human viruses

  8. Regulation of T cell immunity in atopic dermatitis by microbes: The Yin and Yang of cutaneous inflammation

    Directory of Open Access Journals (Sweden)

    Tilo eBiedermann

    2015-07-01

    Full Text Available Atopic dermatitis (AD is a chronic inflammatory skin disease predominantly mediated by T helper cells. While numerous adaptive immune mechanisms in AD pathophysiology have been elucidated in detail, deciphering the impact of innate immunity in AD pathogenesis has made substantial progress in recent years and is currently a fast evolving field. As innate and adaptive immunity are intimately linked cross-talks between these two branches of the immune system are critically influencing the resulting immune response and disease. Innate immune recognition of the cutaneous microbiota was identified to substantially contribute to immune homeostasis and shaping of protective adaptive immunity in the absence of inflammation. Disturbances in the composition of the skin microbiome with reduced microbial diversity and overabundance of Staphylococcus spp. have been shown to be associated with AD inflammation. Distinct S. aureus associated microbial associated molecular patterns (MAMPs binding to TLR2 heterodimers could be identified to initiate long lasting cutaneous inflammation driven by T helper cells and consecutively local immune suppression by induction of myeloid derived suppressor cells (MDSC further favoring secondary skin infections as often seen in AD patients. Moreover dissecting cellular and molecular mechanisms in cutaneous innate immune sensing in AD pathogenesis paved the way for exploiting regulatory and anti-inflammatory pathways to attenuate skin inflammation. Activation of the innate immune system by MAMPs of non-pathogenic bacteria on AD skin alleviated cutaneous inflammation. The induction of tolerogenic dendritic cells, Interleukin-10 expression and regulatory Tr1 cells were shown to mediate this beneficial effect. Thus, activation of innate immunity by MAMPs of non-pathogenic bacteria for induction of regulatory T cell phenotypes seems to be a promising strategy for treatment of inflammatory skin disorders as atopic dermatitis. These

  9. Cellular senescence and tumor suppressor gene p16.

    Science.gov (United States)

    Rayess, Hani; Wang, Marilene B; Srivatsan, Eri S

    2012-04-15

    Cellular senescence is an irreversible arrest of cell growth. Biochemical and morphological changes occur during cellular senescence, including the formation of a unique cellular morphology such as flattened cytoplasm. Function of mitochondria, endoplasmic reticulum and lysosomes are affected resulting in the inhibition of lysosomal and proteosomal pathways. Cellular senescence can be triggered by a number of factors including, aging, DNA damage, oncogene activation and oxidative stress. While the molecular mechanism of senescence involves p16 and p53 tumor suppressor genes and telomere shortening, this review is focused on the mechanism of p16 control. The p16-mediated senescence acts through the retinoblastoma (Rb) pathway inhibiting the action of the cyclin dependant kinases leading to G1 cell cycle arrest. Rb is maintained in a hypophosphorylated state resulting in the inhibition of transcription factor E2F1. Regulation of p16 expression is complex and involves epigenetic control and multiple transcription factors. PRC1 (Pombe repressor complex (1) and PRC2 (Pombe repressor complex (2) proteins and histone deacetylases play an important role in the promoter hypermethylation for suppressing p16 expression. While transcription factors YY1 and Id1 suppress p16 expression, transcription factors CTCF, Sp1 and Ets family members activate p16 transcription. Senescence occurs with the inactivation of suppressor elements leading to the enhanced expression of p16. Copyright © 2011 UICC.

  10. ABCE1 is a highly conserved RNA silencing suppressor.

    Directory of Open Access Journals (Sweden)

    Kairi Kärblane

    Full Text Available ATP-binding cassette sub-family E member 1 (ABCE1 is a highly conserved protein among eukaryotes and archaea. Recent studies have identified ABCE1 as a ribosome-recycling factor important for translation termination in mammalian cells, yeast and also archaea. Here we report another conserved function of ABCE1. We have previously described AtRLI2, the homolog of ABCE1 in the plant Arabidopsis thaliana, as an endogenous suppressor of RNA silencing. In this study we show that this function is conserved: human ABCE1 is able to suppress RNA silencing in Nicotiana benthamiana plants, in mammalian HEK293 cells and in the worm Caenorhabditis elegans. Using co-immunoprecipitation and mass spectrometry, we found a number of potential ABCE1-interacting proteins that might support its function as an endogenous suppressor of RNA interference. The interactor candidates are associated with epigenetic regulation, transcription, RNA processing and mRNA surveillance. In addition, one of the identified proteins is translin, which together with its binding partner TRAX supports RNA interference.

  11. p53 tumor suppressor gene: significance in neoplasia - a review

    International Nuclear Information System (INIS)

    Alam, J.M.

    2000-01-01

    p53 is a tumor suppressor gene located on chromosome 17p13.1. Its function includes cell cycle control and apoptosis. Loss of p53 function, either due to decreased level or genetic transformation, is associated with loss of cell cycle control, decrease, apoptosis and genomic modification, such mutation of p53 gene is now assessed and the indicator of neoplasia of cancer of several organs and cell types, p53 has demonstrated to have critical role in defining various progressive stages of neoplasia, therapeutic strategies and clinical application. The present review briefly describes function of p53 in addition to its diagnostic and prognostic significance in detecting several types of neoplasia. (author)

  12. The potential for tumor suppressor gene therapy in head and neck cancer.

    Science.gov (United States)

    Birkeland, Andrew C; Ludwig, Megan L; Spector, Matthew E; Brenner, J Chad

    2016-01-01

    Head and neck squamous cell carcinoma remains a highly morbid and fatal disease. Importantly, genomic sequencing of head and neck cancers has identified frequent mutations in tumor suppressor genes. While targeted therapeutics increasingly are being investigated in head and neck cancer, the majority of these agents are against overactive/overexpressed oncogenes. Therapy to restore lost tumor suppressor gene function remains a key and under-addressed niche in trials for head and neck cancer. Recent advances in gene editing have captured the interest of both the scientific community and the public. As our technology for gene editing and gene expression modulation improves, addressing lost tumor suppressor gene function in head and neck cancers is becoming a reality. This review will summarize new techniques, challenges to implementation, future directions, and ethical ramifications of gene therapy in head and neck cancer.

  13. Alterations in tumour suppressor gene p53 in human gliomas from ...

    Indian Academy of Sciences (India)

    Unknown

    [Phatak P, Selvi S K, Divya T, Hegde A S, Hegde S and Somasundaram K 2002 Alterations in tumour suppressor gene p53 in human gliomas from Indian patients; J. Biosci. 27 673–678]. 1. Introduction. Glioma, a neoplasm of neuroglial cells, is the most common type of brain tumour, constituting more than 50% of all.

  14. The molecular effect of metastasis suppressors on Src signaling and tumorigenesis: new therapeutic targets

    Science.gov (United States)

    Liu, Wensheng; Kovacevic, Zaklina; Peng, Zhihai; Jin, Runsen; Wang, Puxiongzhi; Yue, Fei; Zheng, Minhua; Huang, Michael L-H.; Jansson, Patric J.; Richardson, Vera; Kalinowski, Danuta S.; Lane, Darius J.R.; Merlot, Angelica M.; Sahni, Sumit; Richardson, Des R.

    2015-01-01

    A major problem for cancer patients is the metastasis of cancer cells from the primary tumor. This involves: (1) migration through the basement membrane; (2) dissemination via the circulatory system; and (3) invasion into a secondary site. Metastasis suppressors, by definition, inhibit metastasis at any step of the metastatic cascade. Notably, Src is a non-receptor, cytoplasmic, tyrosine kinase, which becomes aberrantly activated in many cancer-types following stimulation of plasma membrane receptors (e.g., receptor tyrosine kinases and integrins). There is evidence of a prominent role of Src in tumor progression-related events such as the epithelial–mesenchymal transition (EMT) and the development of metastasis. However, the precise molecular interactions of Src with metastasis suppressors remain unclear. Herein, we review known metastasis suppressors and summarize recent advances in understanding the mechanisms of how these proteins inhibit metastasis through modulation of Src. Particular emphasis is bestowed on the potent metastasis suppressor, N-myc downstream regulated gene 1 (NDRG1) and its interactions with the Src signaling cascade. Recent studies demonstrated a novel mechanism through which NDRG1 plays a significant role in regulating cancer cell migration by inhibiting Src activity. Moreover, we discuss the rationale for targeting metastasis suppressor genes as a sound therapeutic modality, and we review several examples from the literature where such strategies show promise. Collectively, this review summarizes the essential interactions of metastasis suppressors with Src and their effects on progression of cancer metastasis. Moreover, interesting unresolved issues regarding these proteins as well as their potential as therapeutic targets are also discussed. PMID:26431493

  15. Specific Inhibition of the VEGFR-3 Tyrosine Kinase by SAR131675 Reduces Peripheral and Tumor Associated Immunosuppressive Myeloid Cells

    Energy Technology Data Exchange (ETDEWEB)

    Espagnolle, Nicolas [UMR5273 INSERM U1031/CNRS/EFS StromaLab, Toulouse 31432 (France); Barron, Pauline; Mandron, Marie; Blanc, Isabelle; Bonnin, Jacques [Sanofi Recherche et Développement, Early to Candidate DPU, Toulouse 31036 (France); Agnel, Magali; Kerbelec, Erwan [Molecular Biology Unit, Biologics Department, Sanofi, Vitry-sur-Seine 94400 (France); Herault, Jean Pascal; Savi, Pierre; Bono, Françoise; Alam, Antoine, E-mail: antoine.alam@sanofi.com [Sanofi Recherche et Développement, Early to Candidate DPU, Toulouse 31036 (France)

    2014-02-28

    Myeloid derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs) represent prominent components in cancer progression. We previously showed that inhibition of the VEGFR-3 pathway by SAR131675 leads to reduction of TAM infiltration and tumor growth. Here, we found that treatment with SAR131675 prevents the accumulation of immunosuppressive blood and splenic MDSCs which express VEGFR-3, in 4T1 tumor bearing mice. Moreover we showed that soluble factors secreted by tumor cells promote MDSCs proliferation and differentiation into M2 polarized F4/80+ macrophages. In addition, cell sorting and transcriptomic analysis of tumor infiltrating myeloid cells revealed the presence of a heterogeneous population that could be divided into 3 subpopulations: (i) immature cells with a MDSC phenotype (GR1+/CD11b+/F4/80{sup −}); (ii) “immuno-incompetent” macrophages (F4/80{sup high}/CD86{sup neg}/MHCII{sup Low}) strongly expressing M2 markers such as Legumain, CD206 and Mgl1/2 and (iii) “immuno-competent”-M1 like macrophages (F4/80{sup Low}/CD86{sup +}/MHCII{sup High}). SAR131675 treatment reduced MDSCs in lymphoid organs as well as F4/80{sup High} populations in tumors. Interestingly, in the tumor SAR131675 was able to increase the immunocompetent M1 like population (F4/80{sup low}). Altogether these results demonstrate that the specific VEGFR-3 inhibitor SAR131675 exerts its anti tumoral activity by acting on different players that orchestrate immunosuppression and cancer progression in a tumoral context: MDSCs in peripheral lymphoid organs and TAMs infiltrating the tumor.

  16. Whole genome in vivo RNAi screening identifies the leukemia inhibitory factor receptor as a novel breast tumor suppressor.

    Science.gov (United States)

    Iorns, Elizabeth; Ward, Toby M; Dean, Sonja; Jegg, Anna; Thomas, Dafydd; Murugaesu, Nirupa; Sims, David; Mitsopoulos, Costas; Fenwick, Kerry; Kozarewa, Iwanka; Naceur-Lombarelli, Cristina; Zvelebil, Marketa; Isacke, Clare M; Lord, Christopher J; Ashworth, Alan; Hnatyszyn, H James; Pegram, Mark; Lippman, Marc

    2012-08-01

    Cancer is caused by mutations in oncogenes and tumor suppressor genes, resulting in the deregulation of processes fundamental to the normal behavior of cells. The identification and characterization of oncogenes and tumor suppressors has led to new treatment strategies that have significantly improved cancer outcome. The advent of next generation sequencing has allowed the elucidation of the fine structure of cancer genomes, however, the identification of pathogenic changes is complicated by the inherent genomic instability of cancer cells. Therefore, functional approaches for the identification of novel genes involved in the initiation and development of tumors are critical. Here we report the first whole human genome in vivo RNA interference screen to identify functionally important tumor suppressor genes. Using our novel approach, we identify previously validated tumor suppressor genes including TP53 and MNT, as well as several novel candidate tumor suppressor genes including leukemia inhibitory factor receptor (LIFR). We show that LIFR is a key novel tumor suppressor, whose deregulation may drive the transformation of a significant proportion of human breast cancers. These results demonstrate the power of genome wide in vivo RNAi screens as a method for identifying novel genes regulating tumorigenesis.

  17. Molecular genetic analysis of tumor suppressor genes in ovarian cancer

    International Nuclear Information System (INIS)

    Lee, Je Ho; Park, Sang Yun

    1992-04-01

    To examine the loci of putative tumor suppressor genes in ovarian cancers, we performed the molecular genetic analysis with fresh human ovarian cancers and observed the following data. Frequent allelic losses were observed on chromosomes 4p(42%), 6p(50%), 7p(43%), 8q(31%), 12p(38%), 12q(33%), 16p(33%), 16q(37%), and 19p(34%) in addition to the previously reported 6q, 11p, and 17p in ovarian caroinomas. we have used an additional probe, TCP10 to narrow down the deleted region on chromosome 6q. TCP10 was reported to be mapped to 6q 25-27. Allelic loss was found to be 40% in epithelial ovarian caroinomas. This finding suggests that chromosome 6q 24-27 is one of putative region haboring the tumor suppressor gene of epithelial ovarian cancer (particularly serous type). To examine the association between FAL(Fractional Allelic Loss) and histopathological features, the FAL value on each phenotypically different tumor was calculated as the ratio of the number of allelic losses versus the number of cases informative in each chromosomal arm. The average FALs for each phenotypically different tumor were: serous cystoadenocarcinomas. FAL=0.31 : mucinous 0.12 : and clear cell carcinoma. FAL=0.20. (Author)

  18. SERPINB5 and AKAP12 -- Expression and promoter methylation of metastasis suppressor genes in pancreatic ductal adenocarcinoma

    Directory of Open Access Journals (Sweden)

    Haier Joerg

    2010-10-01

    Full Text Available Abstract Background Early metastasis and infiltration are survival limiting characteristics of pancreatic ductal adenocarcinoma (PDAC. Thus, PDAC is likely to harbor alterations in metastasis suppressor genes that may provide novel diagnostic and therapeutic opportunities. This study investigates a panel of metastasis suppressor genes in correlation to PDAC phenotype and examines promoter methylation for regulatory influence on metastasis suppressor gene expression and for its potential as a diagnostic tool. Methods Metastatic and invasive potential of 16 PDAC cell lines were quantified in an orthotopic mouse model and mRNA expression of 11 metastasis suppressor genes determined by quantitative RT-PCR. Analysis for promoter methylation was performed using methylation specific PCR and bisulfite sequencing PCR. Protein expression was determined by Western blot. Results In general, higher metastasis suppressor gene mRNA expression was not consistent with less aggressive phenotypes of PDAC. Instead, mRNA overexpression of several metastasis suppressor genes was found in PDAC cell lines vs. normal pancreatic RNA. Of the investigated metastasis suppressor genes, only higher AKAP12 mRNA expression was correlated with decreased metastasis (P SERPINB5 mRNA expression was correlated with increased metastasis scores (P SERPINB5 methylation was associated with loss of mRNA and protein expression (P SERPINB5 methylation was also directly correlated to decreased metastasis scores (P Conclusions AKAP12 mRNA expression was correlated to attenuated invasive and metastatic potential and may be associated with less aggressive phenotypes of PDAC while no such evidence was obtained for the remaining metastasis suppressor genes. Increased SERPINB5 mRNA expression was correlated to increased metastasis and mRNA expression was regulated by methylation. Thus, SERPINB5 methylation was directly correlated to metastasis scores and may provide a diagnostic tool for PDAC.

  19. Structural basis for c-KIT inhibition by the suppressor of cytokine signaling 6 (SOCS6) ubiquitin ligase

    DEFF Research Database (Denmark)

    Zadjali, Fahad; Pike, Ashley C W; Vesterlund, Mattias

    2011-01-01

    The c-KIT receptor tyrosine kinase mediates the cellular response to stem cell factor (SCF). Whereas c-KIT activity is important for the proliferation of hematopoietic cells, melanocytes and germ cells, uncontrolled c-KIT activity contributes to the growth of diverse human tumors. Suppressor...

  20. RASSF10 is epigenetically silenced and functions as a tumor suppressor in gastric cancer

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Ziran [Department of General Surgery, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai (China); Chen, Xia [Urology Department, Minhang District Central Hospital, Shanghai (China); Chen, Ji; Wang, Weimin [Department of General Surgery, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai (China); Xu, Xudong [Urology Department, Minhang District Central Hospital, Shanghai (China); Cai, Qingping, E-mail: qingping_caicz@163.com [Department of General Surgery, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai (China)

    2013-03-22

    Highlights: ► Epigenetic silencing of RASSF10 gene expression in GC cells. ► RASSF10 overexpression inhibits cell growth in vitro and in vivo. ► RASSF10 induces apoptosis in GC cells. ► RASSF10 inhibits Wnt/β-catenin signaling pathway. -- Abstract: Ras association domain family (RASSF) proteins are encoded by several tumor suppressor genes that are frequently silenced in human cancers. In this study, we investigated RASSF10 as a target of epigenetic inactivation and examined its functions as a tumor suppressor in gastric cancer. RASSF10 was silenced in six out of eight gastric cancer cell lines. Loss or downregulation of RASSF10 expression was associated with promoter hypermethylation, and could be restored by a demethylating agent. Overexpression of RASSF10 in gastric cancer cell lines (JRST, BGC823) suppressed cell growth and colony formation, and induced apoptosis, whereas RASSF10 depletion promoted cell growth. In xenograft animal experiments, RASSF10 overexpression effectively repressed tumor growth. Mechanistic investigations revealed that RASSF10 inhibited tumor growth by blocking activation of β-catenin and its downstream targets including c-Myc, cyclinD1, cyclinE1, peroxisome proliferator-activated receptor δ, transcription factor 4, transcription factor 1 and CD44. In conclusion, the results of this study provide insight into the role of RASSF10 as a novel functional tumor suppressor in gastric cancer through inhibition of the Wnt/β-catenin signaling pathway.

  1. MicroRNA-34a is a potent tumor suppressor molecule in vivo in neuroblastoma.

    LENUS (Irish Health Repository)

    Tivnan, Amanda

    2011-01-01

    Neuroblastoma is a paediatric cancer which originates from precursor cells of the sympathetic nervous system and accounts for 15% of childhood cancer mortalities. With regards to the role of miRNAs in neuroblastoma, miR-34a, mapping to a chromosome 1p36 region that is commonly deleted, has been found to act as a tumor suppressor through targeting of numerous genes associated with cell proliferation and apoptosis.

  2. Anti-proliferative and pro-apoptotic activity of whole extract and isolated indicaxanthin from Opuntia ficus-indica associated with re-activation of the onco-suppressor p16{sup INK4a} gene in human colorectal carcinoma (Caco-2) cells

    Energy Technology Data Exchange (ETDEWEB)

    Naselli, Flores; Tesoriere, Luisa; Caradonna, Fabio; Bellavia, Daniele; Attanzio, Alessandro; Gentile, Carla; Livrea, Maria A., E-mail: maria.livrea@unipa.it

    2014-07-18

    Highlights: • Cactus pear fruit extract and indicaxanthin cause apoptosis of colon cancer cells. • Indicaxanthin does not cause ROS formation, but affects epigenoma in Caco-2 cells. • Indicaxanthin reverses methylation of oncosuppressor p16{sup INK4a} gene in Caco-2 cells. • Indicaxanthin reactivates retinoblastoma in Caco-2 cells. • Bioavailable indicaxanthin may have chemopreventive activity in colon cancer. - Abstract: Phytochemicals may exert chemo-preventive effects on cells of the gastro-intestinal tract by modulating epigenome-regulated gene expression. The effect of the aqueous extract from the edible fruit of Opuntia ficus-indica (OFI extract), and of its betalain pigment indicaxanthin (Ind), on proliferation of human colon cancer Caco-2 cells has been investigated. Whole extract and Ind caused a dose-dependent apoptosis of proliferating cells at nutritionally relevant amounts, with IC{sub 50} 400 ± 25 mg fresh pulp equivalents/mL, and 115 ± 15 μM (n = 9), respectively, without toxicity for post-confluent differentiated cells. Ind accounted for ∼80% of the effect of the whole extract. Ind did not cause oxidative stress in proliferating Caco-2 cells. Epigenomic activity of Ind was evident as de-methylation of the tumor suppressor p16{sup INK4a} gene promoter, reactivation of the silenced mRNA expression and accumulation of p16{sup INK4a}, a major controller of cell cycle. As a consequence, decrease of hyper-phosphorylated, in favor of the hypo-phosphorylated retinoblastoma was observed, with unaltered level of the cycline-dependent kinase CDK4. Cell cycle showed arrest in the G2/M-phase. Dietary cactus pear fruit and Ind may have chemo-preventive potential in intestinal cells.

  3. Functional involvement of human discs large tumor suppressor in cytokinesis

    International Nuclear Information System (INIS)

    Unno, Kenji; Hanada, Toshihiko; Chishti, Athar H.

    2008-01-01

    Cytokinesis is the final step of cell division that completes the separation of two daughter cells. We found that the human discs large (hDlg) tumor suppressor homologue is functionally involved in cytokinesis. The guanylate kinase (GUK) domain of hDlg mediates the localization of hDlg to the midbody during cytokinesis, and over-expression of the GUK domain in U2OS and HeLa cells impaired cytokinesis. Mouse embryonic fibroblasts (MEFs) derived from dlg mutant mice contained an increased number of multinucleated cells and showed reduced proliferation in culture. A kinesin-like motor protein, GAKIN, which binds directly to the GUK domain of hDlg, exhibited a similar intracellular distribution pattern with hDlg throughout mitosis and localized to the midbody during cytokinesis. However, the targeting of hDlg and GAKIN to the midbody appeared to be independent of each other. The midbody localization of GAKIN required its functional kinesin-motor domain. Treatment of cells with the siRNA specific for hDlg and GAKIN caused formation of multinucleated cells and delayed cytokinesis. Together, these results suggest that hDlg and GAKIN play functional roles in the maintenance of midbody architecture during cytokinesis

  4. Tumor Suppressor Function of CYLD in Nonmelanoma Skin Cancer

    Directory of Open Access Journals (Sweden)

    K. C. Masoumi

    2011-01-01

    Full Text Available Ubiquitin and ubiquitin-related proteins posttranslationally modify substrates, and thereby alter the functions of their targets. The ubiquitination process is involved in various physiological responses, and dysregulation of components of the ubiquitin system has been linked to many diseases including skin cancer. The ubiquitin pathways activated among skin cancers are highly diverse and may reflect the various characteristics of the cancer type. Basal cell carcinoma and squamous cell carcinoma, the most common types of human skin cancer, are instances where the involvement of the deubiquitination enzyme CYLD has been recently highlighted. In basal cell carcinoma, the tumor suppressor protein CYLD is repressed at the transcriptional levels through hedgehog signaling pathway. Downregulation of CYLD in basal cell carcinoma was also shown to interfere with TrkC expression and signaling, thereby promoting cancer progression. By contrast, the level of CYLD is unchanged in squamous cell carcinoma, instead, catalytic inactivation of CYLD in the skin has been linked to the development of squamous cell carcinoma. This paper will focus on the current knowledge that links CYLD to nonmelanoma skin cancers and will explore recent insights regarding CYLD regulation of NF-κB and hedgehog signaling during the development and progression of these types of human tumors.

  5. Tumor suppressor WWOX and p53 alterations and drug resistance in glioblastomas

    Directory of Open Access Journals (Sweden)

    Ming-Fu eChiang

    2013-03-01

    Full Text Available Tumor suppressor p53 are frequently mutated in glioblastomas (GBMs and appears to contribute, in part, to resistance to temozolomide and therapeutic drugs. WW domain-containing oxidoreductase WWOX (FOR or WOX1 is a proapoptotic protein and is considered as a tumor suppressor. Loss of WWOX gene expression is frequently seen in malignant cancer cells due to promoter hypermethylation, genetic alterations, and translational blockade. Intriguingly, ectopic expression of wild type WWOX preferentially induces apoptosis in human glioblastoma cells harboring mutant p53. WWOX is known to physically bind and stabilize wild type p53. Here, we provide an overview for the updated knowledge in p53 and WWOX, and postulate a potential scenarios that wild type and mutant p53, or isoforms, modulate the apoptotic function of WWOX. We propose that triggering WWOX activation by therapeutic drugs under p53 functional deficiency is needed to overcome TMZ resistance and induce GBM cell death.

  6. Analyses of tumor-suppressor genes in germline mouse models of cancer.

    Science.gov (United States)

    Wang, Jingqiang; Abate-Shen, Cory

    2014-08-01

    Tumor-suppressor genes are critical regulators of growth and functioning of cells, whose loss of function contributes to tumorigenesis. Accordingly, analyses of the consequences of their loss of function in genetically engineered mouse models have provided important insights into mechanisms of human cancer, as well as resources for preclinical analyses and biomarker discovery. Nowadays, most investigations of genetically engineered mouse models of tumor-suppressor function use conditional or inducible alleles, which enable analyses in specific cancer (tissue) types and overcome the consequences of embryonic lethality of germline loss of function of essential tumor-suppressor genes. However, historically, analyses of genetically engineered mouse models based on germline loss of function of tumor-suppressor genes were very important as these early studies established the principle that loss of function could be studied in mouse cancer models and also enabled analyses of these essential genes in an organismal context. Although the cancer phenotypes of these early germline models did not always recapitulate the expected phenotypes in human cancer, these models provided the essential foundation for the more sophisticated conditional and inducible models that are currently in use. Here, we describe these "first-generation" germline models of loss of function models, focusing on the important lessons learned from their analyses, which helped in the design and analyses of "next-generation" genetically engineered mouse models. © 2014 Cold Spring Harbor Laboratory Press.

  7. Characteristics of Suppressor Macrophages Induced by Mycobacterial and Protozoal Infections in relation to Alternatively Activated M2 Macrophages

    Directory of Open Access Journals (Sweden)

    Haruaki Tomioka

    2012-01-01

    Full Text Available In the advanced stages of mycobacterial infections, host immune systems tend to change from a Th1-type to Th2-type immune response, resulting in the abrogation of Th1 cell- and macrophage-mediated antimicrobial host protective immunity. Notably, this type of immune conversion is occasionally associated with the generation of certain types of suppressor macrophage populations. During the course of Mycobacterium tuberculosis (MTB and Mycobacterium avium-intracellulare complex (MAC infections, the generation of macrophages which possess strong suppressor activity against host T- and B-cell functions is frequently encountered. This paper describes the immunological properties of M1- and M2-type macrophages generated in tumor-bearing animals and those generated in hosts with certain microbial infections. In addition, this paper highlights the immunological and molecular biological characteristics of suppressor macrophages generated in hosts with mycobacterial infections, especially MAC infection.

  8. Epigenetic regulation of putative tumor suppressor TGFBI in human leukemias.

    Science.gov (United States)

    Fang, Hongbo; Liu, Jing; Guo, Dan; Liu, Peixiang; Zhao, Yongliang

    2014-01-01

    Both in vitro and in vivo data have demonstrated the TGFBI gene functions as a putative tumor suppressor and is frequently downregulated in human tumors of different histological types. The hypermethylation of the TGFBI promoter, as one of the main regulatory mechanisms, is associated with TGFBI silencing. In this study, we used a methylation-specific PCR (MSP) method to evaluate the methylation status of the TGFBI promoter in human leukemias. Real-time RT-PCR and methylation-specific PCR approaches were performed to define the TGFBI expression and promoter methylation in human leukemia cell lines and clinical samples. Genomic DNA was isolated from peripheral blood mononuclear cells from leukemia patients, bisulfite-converted, and analyzed by the MSP method. Hypermethylation of the TGFBI promoter occurred in leukemia cell lines and demethylation treatment reexpressed TGFBI at a substantially increased level in most of leukemia cell lines tested. Furthermore, a much higher level of CpG island methylation and a significantly lower TGFBI expression were also identified in clinical leukemia samples. The results suggest an important role of promoter methylation in regulating TGFBI expression in leukemia, which provides a useful diagnostic marker for clinical management of human leukemias.

  9. PML tumor suppressor protein is required for HCV production

    Energy Technology Data Exchange (ETDEWEB)

    Kuroki, Misao [Department of Tumor Virology, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, 2-5-1, Shikata-cho, Okayama 700-8558 (Japan); Research Fellow of the Japan Society for the Promotion of Science (Japan); Center for AIDS Research, Kumamoto University, Kumamoto 860-0811 (Japan); Ariumi, Yasuo, E-mail: ariumi@kumamoto-u.ac.jp [Department of Tumor Virology, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, 2-5-1, Shikata-cho, Okayama 700-8558 (Japan); Center for AIDS Research, Kumamoto University, Kumamoto 860-0811 (Japan); Hijikata, Makoto [Department of Viral Oncology, Institute for Virus Research, Kyoto University, Kyoto 606-8507 (Japan); Ikeda, Masanori; Dansako, Hiromichi [Department of Tumor Virology, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, 2-5-1, Shikata-cho, Okayama 700-8558 (Japan); Wakita, Takaji [Department of Virology II, National Institute of Infectious Diseases, Tokyo 162-8640 (Japan); Shimotohno, Kunitada [Research Center for Hepatitis and Immunology, National Center for Global Health and Medicine, Ichikawa, Chiba 272-8516 (Japan); Kato, Nobuyuki [Department of Tumor Virology, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, 2-5-1, Shikata-cho, Okayama 700-8558 (Japan)

    2013-01-11

    Highlights: Black-Right-Pointing-Pointer PML tumor suppressor protein is required for HCV production. Black-Right-Pointing-Pointer PML is dispensable for HCV RNA replication. Black-Right-Pointing-Pointer HCV could not alter formation of PML-NBs. Black-Right-Pointing-Pointer INI1 and DDX5, PML-related proteins, are involved in HCV life cycle. -- Abstract: PML tumor suppressor protein, which forms discrete nuclear structures termed PML-nuclear bodies, has been associated with several cellular functions, including cell proliferation, apoptosis and antiviral defense. Recently, it was reported that the HCV core protein colocalizes with PML in PML-NBs and abrogates the PML function through interaction with PML. However, role(s) of PML in HCV life cycle is unknown. To test whether or not PML affects HCV life cycle, we examined the level of secreted HCV core and the infectivity of HCV in the culture supernatants as well as the level of HCV RNA in HuH-7-derived RSc cells, in which HCV-JFH1 can infect and efficiently replicate, stably expressing short hairpin RNA targeted to PML. In this context, the level of secreted HCV core and the infectivity in the supernatants from PML knockdown cells was remarkably reduced, whereas the level of HCV RNA in the PML knockdown cells was not significantly affected in spite of very effective knockdown of PML. In fact, we showed that PML is unrelated to HCV RNA replication using the subgenomic HCV-JFH1 replicon RNA, JRN/3-5B. Furthermore, the infectivity of HCV-like particle in the culture supernatants was significantly reduced in PML knockdown JRN/3-5B cells expressing core to NS2 coding region of HCV-JFH1 genome using the trans-packaging system. Finally, we also demonstrated that INI1 and DDX5, the PML-related proteins, are involved in HCV production. Taken together, these findings suggest that PML is required for HCV production.

  10. The Ras effector RASSF2 is a novel tumor-suppressor gene in human colorectal cancer.

    Science.gov (United States)

    Akino, Kimishige; Toyota, Minoru; Suzuki, Hiromu; Mita, Hiroaki; Sasaki, Yasushi; Ohe-Toyota, Mutsumi; Issa, Jean-Pierre J; Hinoda, Yuji; Imai, Kohzoh; Tokino, Takashi

    2005-07-01

    Activation of Ras signaling is a hallmark of colorectal cancer (CRC), but the roles of negative regulators of Ras are not fully understood. Our aim was to address that question by surveying genetic and epigenetic alterations of Ras-Ras effector genes in CRC cells. The expression and methylation status of 6 RASSF family genes were examined using RT-PCR and bisulfite PCR in CRC cell lines and in primary CRCs and colorectal adenomas. Colony formation assays and flow cytometry were used to assess the tumor suppressor activities of RASSF1 and RASSF2. Immunofluorescence microscopy was used to determine the effect of altered RASSF2 expression on cell morphology. Mutations of K- ras , BRAF, and p53 were identified using single-strand conformation analysis and direct sequencing. Aberrant methylation and histone deacetylation of RASSF2 was associated with the gene's silencing in CRC. The activities of RASSF2, which were distinct from those of RASSF1, included induction of morphologic changes and apoptosis; moreover, its ability to prevent cell transformation suggests that RASSF2 acts as a tumor suppressor in CRC. Primary CRCs that showed K- ras /BRAF mutations also frequently showed RASSF2 methylation, and inactivation of RASSF2 enhanced K- ras -induced oncogenic transformation. RASSF2 methylation was also frequently identified in colorectal adenomas. RASSF2 is a novel tumor suppressor gene that regulates Ras signaling and plays a pivotal role in the early stages of colorectal tumorigenesis.

  11. Suppressors of RNA silencing encoded by tomato leaf curl ...

    Indian Academy of Sciences (India)

    2013-01-06

    Jan 6, 2013 ... satellite DNA β which are predicted to function as silencing suppressors. In the present study suppressor function ... of plant viruses with circular single-stranded DNA genomes that are composed of one or two components of ..... 1 2 3 4 5 6 7 8 9 10 11 12 13 14 M. Figure 4. Southern blot analysis of DNA ...

  12. Signalling through FOXP3 as an X-linked Tumor Suppressor

    Science.gov (United States)

    Katoh, Hiroto; Zheng, Pan; Liu, Yang

    2010-01-01

    The FOXP3 (forkhead box P3) gene is a member of forkhead winged helix family transcription factors and functions as both a transcriptional activator and a repressor. FOXP3 dysfunction is responsible for an X-linked autoimmune syndrome: immune dysregulation, polyendopathy, enterophathy, X-linked syndrome. In addition to its role as an essential transcription factor in regulatory T cells, the FOXP3 gene is an epithelial cell-intrinsic tumor suppressor for breast and prostate cancers. We will focus on the FOXP3 signalling pathway in epithelial cells and discuss how genetic and/or epigenetic inactivation of the FOXP3 contributes to the malignant transformation of cells. PMID:20678582

  13. Extragenic suppressor mutations in ΔripA disrupt stability and function of LpxA.

    Science.gov (United States)

    Miller, Cheryl N; Steele, Shaun P; Brunton, Jason C; Jenkins, Ronald J; LoVullo, Eric D; Taft-Benz, Sharon A; Romanchuk, Artur; Jones, Corbin D; Dotson, Garry D; Collins, Edward J; Kawula, Thomas H

    2014-12-31

    Francisella tularensis is a Gram-negative bacterium that infects hundreds of species including humans, and has evolved to grow efficiently within a plethora of cell types. RipA is a conserved membrane protein of F. tularensis, which is required for growth inside host cells. As a means to determine RipA function we isolated and mapped independent extragenic suppressor mutants in ∆ripA that restored growth in host cells. Each suppressor mutation mapped to one of two essential genes, lpxA or glmU, which are involved in lipid A synthesis. We repaired the suppressor mutation in lpxA (S102, LpxA T36N) and the mutation in glmU (S103, GlmU E57D), and demonstrated that each mutation was responsible for the suppressor phenotype in their respective strains. We hypothesize that the mutation in S102 altered the stability of LpxA, which can provide a clue to RipA function. LpxA is an UDP-N-acetylglucosamine acyltransferase that catalyzes the transfer of an acyl chain from acyl carrier protein (ACP) to UDP-N-acetylglucosamine (UDP-GlcNAc) to begin lipid A synthesis. LpxA was more abundant in the presence of RipA. Induced expression of lpxA in the ΔripA strain stopped bacterial division. The LpxA T36N S102 protein was less stable and therefore less abundant than wild type LpxA protein. These data suggest RipA functions to modulate lipid A synthesis in F. tularensis as a way to adapt to the host cell environment by interacting with LpxA.

  14. The p53 tumour suppressor gene and the tobacco industry: research, debate, and conflict of interest

    OpenAIRE

    Bitton, A; Neuman, M D; Barnoya, J; Glantz, Stanton A. Ph.D.

    2005-01-01

    Mutations in the p53 tumour suppressor gene lead to uncontrolled cell division and are found in over 50% of all human tumours, including 60% of lung cancers. Research published in 1996 by Denissenko and colleagues demonstrated patterned in-vitro mutagenic effects on p53 of benzo[a]pyrene, a carcinogen present in tobacco smoke. We investigated the tobacco industry's response to p53 research linking smoking to cancer. We searched online tobacco document archives, including the Legacy Tobacco Do...

  15. Macrophages, Inflammation, and Tumor Suppressors: ARF, a New Player in the Game

    Directory of Open Access Journals (Sweden)

    Paqui G. Través

    2012-01-01

    Full Text Available The interaction between tumor progression and innate immune system has been well established in the last years. Indeed, several lines of clinical evidence indicate that immune cells such as tumor-associated macrophages (TAMs interact with tumor cells, favoring growth, angiogenesis, and metastasis of a variety of cancers. In most tumors, TAMs show properties of an alternative polarization phenotype (M2 characterized by the expression of a series of chemokines, cytokines, and proteases that promote immunosuppression, tumor proliferation, and spreading of the cancer cells. Tumor suppressor genes have been traditionally linked to the regulation of cancer progression; however, a growing body of evidence indicates that these genes also play essential roles in the regulation of innate immunity pathways through molecular mechanisms that are still poorly understood. In this paper, we provide an overview of the immunobiology of TAMs as well as what is known about tumor suppressors in the context of immune responses. Recent advances regarding the role of the tumor suppressor ARF as a regulator of inflammation and macrophage polarization are also reviewed.

  16. Tumor-suppressor activity of RRIG1 in breast cancer

    International Nuclear Information System (INIS)

    Zhang, Guihong; Brewster, Abenaa; Guan, Baoxiang; Fan, Zhen; Brown, Powel H; Xu, Xiao-Chun

    2011-01-01

    Retinoid receptor-induced gene-1 (RRIG1) is a novel gene that has been lost in several types of human cancers. The aim of this study was to determine whether RRIG1 plays a role in breast cancer, such as in the suppression of breast cancer cell growth and invasion. Immunohistochemistry was used to detect RRIG1 expression in breast tissue specimens. Gene transfection was used to restore or knock down RRIG1 expression in breast cancer cell lines for analysis of cell viability, colony formation, and migration/invasion potential. Reverse-transcription polymerase chain reaction and western blot assays were used to detect the changes in gene expression. The RhoA activation assay was used to assess RRIG1-induced inhibition of RhoA activity. The immunohistochemical data showed that RRIG1 expression was reduced in breast cancer tissues compared with normal and atypical hyperplastic breast tissues. RRIG1 expression was inversely correlated with lymph node metastasis of breast cancer but was not associated with the status of hormone receptors, such as estrogen receptor, progesterone receptor, or HER2. Furthermore, restoration of RRIG1 expression inhibited proliferation, colony formation, migration, and invasion of breast cancer cells. Expression of RRIG1 also reduced phosphorylated Erk1/2 and Akt levels; c-Jun, MMP9, and Akt expressions; and RhoA activity. In contrast, knockdown of RRIG1 expression promoted breast cancer cell proliferation, colony formation, migration, and invasion potential. The data from the current study indicated that RRIG1 expression was reduced or lost in breast cancer and that restoration of RRIG1 expression suppressed breast cancer cell growth and invasion capacity. Future studies will determine the underlying molecular mechanisms and define RRIG1 as a tumor-suppressor gene in breast cancer

  17. Transducer of ERBB2.1 (TOB1 as a Tumor Suppressor: A Mechanistic Perspective

    Directory of Open Access Journals (Sweden)

    Hun Seok Lee

    2015-12-01

    Full Text Available Transducer of ERBB2.1 (TOB1 is a tumor-suppressor protein, which functions as a negative regulator of the receptor tyrosine-kinase ERBB2. As most of the other tumor suppressor proteins, TOB1 is inactivated in many human cancers. Homozygous deletion of TOB1 in mice is reported to be responsible for cancer development in the lung, liver, and lymph node, whereas the ectopic overexpression of TOB1 shows anti-proliferation, and a decrease in the migration and invasion abilities on cancer cells. Biochemical studies revealed that the anti-proliferative activity of TOB1 involves mRNA deadenylation and is associated with the reduction of both cyclin D1 and cyclin-dependent kinase (CDK expressions and the induction of CDK inhibitors. Moreover, TOB1 interacts with an oncogenic signaling mediator, β-catenin, and inhibits β-catenin-regulated gene transcription. TOB1 antagonizes the v-akt murine thymoma viral oncogene (AKT signaling and induces cancer cell apoptosis by activating BCL2-associated X (BAX protein and inhibiting the BCL-2 and BCL-XL expressions. The tumor-specific overexpression of TOB1 results in the activation of other tumor suppressor proteins, such as mothers against decapentaplegic homolog 4 (SMAD4 and phosphatase and tensin homolog-10 (PTEN, and blocks tumor progression. TOB1-overexpressing cancer cells have limited potential of growing as xenograft tumors in nude mice upon subcutaneous implantation. This review addresses the molecular basis of TOB1 tumor suppressor function with special emphasis on its regulation of intracellular signaling pathways.

  18. Mutation analysis of suppressor of cytokine signalling 3, a candidate gene in Type 1 diabetes and insulin sensitivity

    DEFF Research Database (Denmark)

    Gylvin, T; Nolsøe, R; Hansen, T

    2004-01-01

    Beta cell loss in Type 1 and Type 2 diabetes mellitus may result from apoptosis and necrosis induced by inflammatory mediators. The suppressor of cytokine signalling (SOCS)-3 is a natural inhibitor of cytokine signalling and also influences insulin signalling. SOCS3 could therefore be a candidate...... gene in the development of Type 1 and Type 2 diabetes mellitus....

  19. LARG at chromosome 11q23 has functional characteristics of a tumor suppressor in human breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ong, Danny C.T.; Rudduck, Christina; Chin, Koei; Kuo, Wen-Lin; Lie, Daniel K.H.; Chua, Constance L.M.; Wong, Chow Yin; Hong, Ga Sze; Gray, Joe; Lee, Ann S.G.

    2008-05-06

    Deletion of 11q23-q24 is frequent in a diverse variety of malignancies, including breast and colorectal carcinoma, implicating the presence of a tumor suppressor gene at that chromosomal region. We show here that LARG, from 11q23, has functional characteristics of a tumor suppressor. We examined a 6-Mb region on 11q23 by high-resolution deletion mapping, utilizing both loss of heterozygosity (LOH) analysis and microarray comparative genomic hybridization (CGH). LARG (also called ARHGEF12), identified from the analyzed region, was underexpressed in 34% of primary breast carcinomas and 80% of breast cancer cell lines including the MCF-7 line. Multiplex ligation-dependent probe amplification on 30 primary breast cancers and six breast cancer cell lines showed that LARG had the highest frequency of deletion compared to the BCSC-1 and TSLC1 genes, two known candidate tumor suppressor genes from 11q. In vitro analysis of breast cancer cell lines that underexpress LARG showed that LARG could be reactivated by trichostatin A, a histone deacetylase inhibitor, but not by 5-Aza-2{prime}-deoxycytidine, a demethylating agent. Bisulfite sequencing and quantitative high-throughput analysis of DNA methylation confirmed the lack of CpG island methylation in LARG in breast cancer. Restoration of LARG expression in MCF-7 cells by stable transfection resulted in reduced proliferation and colony formation, suggesting that LARG has functional characteristics of a tumor suppressor gene.

  20. Overexpression of the p53 tumor suppressor gene product in primary lung adenocarcinomas is associated with cigarette smoking

    NARCIS (Netherlands)

    Westra, W. H.; Offerhaus, G. J.; Goodman, S. N.; Slebos, R. J.; Polak, M.; Baas, I. O.; Rodenhuis, S.; Hruban, R. H.

    1993-01-01

    Mutations in the p53 tumor suppressor gene are frequently observed in primary lung adenocarcinomas, suggesting that these mutations are critical events in the malignant transformation of airway cells. These mutations are often associated with stabilization of the p53 gene product, resulting in the

  1. Chemokine receptor CXCR4 downregulated by von Hippel-Lindau tumour suppressor pVHL

    DEFF Research Database (Denmark)

    Staller, Peter; Sulitkova, Jitka; Lisztwan, Joanna

    2003-01-01

    regulates CXCR4 expression owing to its capacity to target hypoxia-inducible factor (HIF) for degradation under normoxic conditions. This process is suppressed under hypoxic conditions, resulting in HIF-dependent CXCR4 activation. An analysis of clear cell renal carcinoma that manifests mutation of the VHL...... of the CXCR4-specific ligand stromal cell-derived factor-1alpha (ref. 1). It is still uncertain how an evolving tumour cell is reprogrammed to express CXCR4, thus implementing the tendency to metastasize to specific organs. Here we show that the von Hippel-Lindau tumour suppressor protein pVHL negatively...

  2. Articular Cartilage Repair Through Muscle Cell-Based Tissue Engineering

    Science.gov (United States)

    2011-03-01

    TaqMan probe AAC-CCT-CTT- TTC -GGA-TTA-ACC-CTG-CGA- GTT. Articular cartilage defect model and cell transplanta- tion. All animal experiments were... inhalation mask. The knee joint was exposed by medial parapa- tellar incision, and the trochlear groove was exposed by lateral dislocation of the...least significant difference test. P values less than 0.05 were considered significant. RESULTS In vitro MDSC characterization. Flow cytometric analysis

  3. Potential of lactic acid bacteria as suppressors of wine allergies

    Directory of Open Access Journals (Sweden)

    Yıldırım Hatice Kalkan

    2017-01-01

    Full Text Available Allergens causes some symptoms as all asthma, allergic conjunctivitis, and allergic rhinitis. These symptoms are seen twice as many in women than in men. The major wine allergens reported in wines are endochitinase 4A and lipid-transfer protein (LTP. This review deal with possibilities of using lactic acid bacteria as suppressors of wine allergies. Phenolic compounds present in wines have not only antioxidant properties causing radical scavenging but also some special properties reported in many in vitro studies as regulating functions in inflammatory cells as mast cells. So what is the role of lactic acid bacteria in these cases? Lactic acid bacteria are used during malolactic fermentation step of wine production with purpose of malic acid reduction. During this bioconversion complex phenolic compounds could be hydrolysed by bacterial enzymes to their aglycone forms. Obtained aglycons could pass through the intestinal epithelium of human and allowed reduction of IgE antibody production by affecting Th1/ Th2 ratio. Considering different contents and quantities of phenols in different grape varieties and consequently in different wines more studies are required in order to determine which lactic acid bacteria and strains could be effective in suppressing wine allergens.

  4. Regulation of the tumor suppressor PTEN by natural anticancer compounds.

    Science.gov (United States)

    Kim, Do-Hee; Suh, Jinyoung; Surh, Young-Joon; Na, Hye-Kyung

    2017-08-01

    The tumor suppressor phosphatase and tensin homologue (PTEN) has phosphatase activity, with phosphatidylinositol (3,4,5)-trisphosphate (PIP3), a product of phosphatidylinositol 3-kinase (PI3K), as one of the principal substrates. PTEN is a negative regulator of the Akt pathway, which plays a fundamental role in controlling cell growth, survival, and proliferation. Loss of PTEN function has been observed in many different types of cancer. Functional inactivation of PTEN as a consequence of germ-line mutations or promoter hypermethylation predisposes individuals to malignancies. PTEN undergoes posttranslational modifications, such as oxidation, acetylation, phosphorylation, SUMOylation, and ubiquitination, which influence its catalytic activity, interactions with other proteins, and subcellular localization. Cellular redox status is crucial for posttranslational modification of PTEN and its functional consequences. Oxidative stress and inflammation are major causes of loss of PTEN function. Pharmacologic or nutritional restoration of PTEN function is considered a reliable strategy in the management of PTEN-defective cancer. In this review, we highlight natural compounds, such as curcumin, indol-3 carbinol, and omega-3 fatty acids, that have the potential to restore or potentiate PTEN expression/activity, thereby suppressing cancer cell proliferation, survival, and resistance to chemotherapeutic agents. © 2017 New York Academy of Sciences.

  5. SIRT3: Oncogene and Tumor Suppressor in Cancer

    Directory of Open Access Journals (Sweden)

    Margalida Torrens-Mas

    2017-07-01

    Full Text Available Sirtuin 3 (SIRT3, the major deacetylase in mitochondria, plays a crucial role in modulating oxygen reactive species (ROS and limiting the oxidative damage in cellular components. SIRT3 targets different enzymes which regulate mitochondrial metabolism and participate in ROS detoxification, such as the complexes of the respiratory chain, the isocitrate dehydrogenase, or the manganese superoxide dismutase. Thus, SIRT3 activity is essential in maintaining mitochondria homeostasis and has recently received great attention, as it is considered a fidelity protein for mitochondrial function. In some types of cancer, SIRT3 functions as a tumoral promoter, since it keeps ROS levels under a certain threshold compatible with cell viability and proliferation. On the contrary, other studies describe SIRT3 as a tumoral suppressor, as SIRT3 could trigger cell death under stress conditions. Thus, SIRT3 could have a dual role in cancer. In this regard, modulation of SIRT3 activity could be a new target to develop more personalized therapies against cancer.

  6. Latexin exhibits tumor-suppressor potential in pancreatic ductal adenocarcinoma

    Science.gov (United States)

    XUE, ZHANXIONG; ZHOU, YUHUI; WANG, CHENG; ZHENG, JIHANG; ZHANG, PU; ZHOU, LINGLING; WU, LIANG; SHAN, YUNFENG; YE, MENGSI; HE, YUN; CAI, ZHENZHAI

    2016-01-01

    Recent studies suggest that latexin (Lxn) expression is involved in stem cell regulation and that it plays significant roles in tumor cell migration and invasion. The clinicopathological significance of Lxn expression and its possible correlation with CD133 expression in pancreatic ductal adenocarcinoma (PDAC) is currently unknown. In the present study, immunohistochemical analysis was performed to determine Lxn and CD133 expression in 43 PDAC patient samples and in 32 corresponding adjacent non-cancerous samples. The results were analyzed and compared with patient age, gender, tumor site and size, histological grade, clinical stage and overall mean survival time. Lxn expression was clearly decreased in the PDAC tissues compared with that in the adjacent non-cancerous tissues, while CD133 expression was increased. Low Lxn expression in the PDAC tissues was significantly correlated with tumor size (P=0.002), histological grade (P=0.000), metastasis (P=0.007) and clinical stage (P=0.018), but not with age (P=0.451), gender (P=0.395) or tumor site (P=0.697). Kaplan-Meier survival analysis revealed that low Lxn expression was significantly correlated with reduced overall survival time (P=0.000). Furthermore, Lxn expression was found to be inversely correlated with CD133 expression (r=−0.485, P=0.001). Furthermore, CD133-positive MIA PaCa-2 pancreatic tumor cells were sorted by magnetic-activated cell sorting (MACS), and those that overexpressed Lxn exhibited a significantly higher rate of apoptosis and lower proliferative activity. Our findings suggest that Lxn may function as a tumor suppressor that targets CD133-positive pancreatic cancer cells. PMID:26530530

  7. Visualization of Tumor-Immune Interaction - Target-Specific Imaging of S100A8/A9 Reveals Pre-Metastatic Niche Establishment

    NARCIS (Netherlands)

    Eisenblaetter, M.; Flores-Borja, F.; Lee, J.J.; Wefers, C.; Smith, H.; Hueting, R.; Cooper, M.S.; Blower, P.J.; Patel, D.; Rodriguez-Justo, M.; Milewicz, H.; Vogl, T.; Roth, J.; Tutt, A.; Schaeffter, T.; Ng, T.

    2017-01-01

    Background Systemic cancer spread is preceded by the establishment of a permissive microenvironment in the target tissue of metastasis - the premetastatic niche. As crucial players in establishment of the pre-metastatic niche, myeloid derived suppressor cells (MDSC) release S100A8/A9, an exosomal

  8. Analysis of chikungunya virus proteins reveals that non-structural proteins nsP2 and nsP3 exhibit RNA interference (RNAi) suppressor activity.

    Science.gov (United States)

    Mathur, Kalika; Anand, Abhishek; Dubey, Sunil Kumar; Sanan-Mishra, Neeti; Bhatnagar, Raj K; Sunil, Sujatha

    2016-11-30

    RNAi pathway is an antiviral defence mechanism employed by insects that result in degradation of viral RNA thereby curbing infection. Several viruses including flaviviruses encode viral suppressors of RNAi (VSRs) to counteract the antiviral RNAi pathway. Till date, no VSR has been reported in alphaviruses. The present study was undertaken to evaluate chikungunya virus (CHIKV) proteins for RNAi suppressor activity. We systematically analyzed all nine CHIKV proteins for RNAi suppressor activity using Sf21 RNAi sensor cell line based assay. Two non-structural proteins, namely, nsP2 and nsP3 were found to exhibit RNAi suppressor activity. We further validated the findings in natural hosts, namely in Aedes and in mammalian cell lines and further through EMSA and Agrobacterium infiltration in GFP silenced transgenic tobacco plants. Domains responsible for maximum RNAi suppressor activity were also identified within these proteins. RNA binding motifs in these domains were identified and their participation in RNAi suppression evaluated using site directed mutagenesis. Sequence alignment of these motifs across all species of known alphaviruses revealed conservation of these motifs emphasizing on a similar role of action in other species of alphaviruses as well. Further validation of RNAi suppressor activity of these proteins awaits establishment of specific virus infection models.

  9. Hypermethylation of the tumor suppressor gene PRDM1/Blimp-1 supports a pathogenetic role in EBV-positive Burkitt lymphoma

    International Nuclear Information System (INIS)

    Zhang, T; Ma, J; Nie, K; Yan, J; Liu, Y; Bacchi, C E; Queiroga, E M; Gualco, G; Sample, J T; Orazi, A; Knowles, D M; Tam, W

    2014-01-01

    PRDM1/Blimp-1 is a tumor suppressor gene in the activated B-cell subtype of diffuse large B-cell lymphomas. Its inactivation contributes to pathogenesis in this setting by impairing terminal B-cell differentiation induced by constitutive nuclear factor-κB activation. The role of PRDM1 in Burkitt lymphoma (BL) lymphomagenesis is not known. Here we identified hypermethylation of the promoter region and exon 1 of PRDM1 in all six Epstein–Barr virus (EBV)-positive BL cell lines and 12 of 23 (52%) primary EBV-positive BL or BL-related cases examined, but in none of the EBV-negative BL cell lines or primary tumors that we assessed, implying a tumor suppressor role for PRDM1 specifically in EBV-associated BL. A direct induction of PRDM1 hypermethylation by EBV is unlikely, as PRDM1 hypermethylation was not observed in EBV-immortalized B lymphoblastoid cell lines. Treatment of EBV-positive BL cells with 5′ azacytidine resulted in PRDM1 induction associated with PRDM1 demethylation, consistent with transcriptional silencing of PRDM1 as a result of DNA methylation. Overexpression of PRDM1 in EBV-positive BL cell lines resulted in cell cycle arrest. Our results expand the spectrum of lymphoid malignancies in which PRDM1 may have a tumor suppressor role and identify an epigenetic event that likely contributes to the pathogenesis of BL

  10. Hypermethylation of the tumor suppressor gene PRDM1/Blimp-1 supports a pathogenetic role in EBV-positive Burkitt lymphoma.

    Science.gov (United States)

    Zhang, T; Ma, J; Nie, K; Yan, J; Liu, Y; Bacchi, C E; Queiroga, E M; Gualco, G; Sample, J T; Orazi, A; Knowles, D M; Tam, W

    2014-11-07

    PRDM1/Blimp-1 is a tumor suppressor gene in the activated B-cell subtype of diffuse large B-cell lymphomas. Its inactivation contributes to pathogenesis in this setting by impairing terminal B-cell differentiation induced by constitutive nuclear factor-κB activation. The role of PRDM1 in Burkitt lymphoma (BL) lymphomagenesis is not known. Here we identified hypermethylation of the promoter region and exon 1 of PRDM1 in all six Epstein-Barr virus (EBV)-positive BL cell lines and 12 of 23 (52%) primary EBV-positive BL or BL-related cases examined, but in none of the EBV-negative BL cell lines or primary tumors that we assessed, implying a tumor suppressor role for PRDM1 specifically in EBV-associated BL. A direct induction of PRDM1 hypermethylation by EBV is unlikely, as PRDM1 hypermethylation was not observed in EBV-immortalized B lymphoblastoid cell lines. Treatment of EBV-positive BL cells with 5' azacytidine resulted in PRDM1 induction associated with PRDM1 demethylation, consistent with transcriptional silencing of PRDM1 as a result of DNA methylation. Overexpression of PRDM1 in EBV-positive BL cell lines resulted in cell cycle arrest. Our results expand the spectrum of lymphoid malignancies in which PRDM1 may have a tumor suppressor role and identify an epigenetic event that likely contributes to the pathogenesis of BL.

  11. Suppressor of cytokine signalling-3 expression inhibits cytokine-mediated destruction of primary mouse and rat pancreatic islets and delays allograft rejection

    DEFF Research Database (Denmark)

    Rønn, S G; Börjesson, A; Bruun, C

    2008-01-01

    The pro-inflammatory cytokines IL-1 and IFNgamma are critical molecules in immune-mediated beta cell destruction leading to type 1 diabetes mellitus. Suppressor of cytokine signalling (SOCS)-3 inhibits the cytokine-mediated destruction of insulinoma-1 cells. Here we investigate the effect of SOCS...... in primary rodent beta cells and diabetic animal models....

  12. Regulation of the Tumor Suppressor Protein PTEN by Phosphorylation

    National Research Council Canada - National Science Library

    Vasquez, Fancisca

    2001-01-01

    The purpose of the research project of this grant is to study the role of phosphorylation on the regulation of PTEN, a tumor suppressor localized on a chromosome region frequently deleted in various...

  13. PTEN, a Tumor Suppressor Gene for Prostate Cancer

    National Research Council Canada - National Science Library

    Ittmann, Michael

    1999-01-01

    .... The PTEN gene is a tumor suppressor gene recently cloned from human chromosome 10q23.3 that encodes a lipid phosphatase which influences a variety of cellular processes that impact on the neoplastic phenotype...

  14. Regulation of the Tumor Suppressor Protein PTEN by Phosphorylation

    National Research Council Canada - National Science Library

    Vazquez, Francisca

    2000-01-01

    The purpose of the research project of this grant is to study the role of phosphorylation on the regulation of PTEN, a tumor suppressor localized on a chromosome region frequently deleted in various...

  15. The Retinoblastoma Tumor Suppressor Regulates a Xenobiotic Detoxification Pathway

    Science.gov (United States)

    Sáenz Robles, Maria Teresa; Case, Ashley; Chong, Jean-Leon; Leone, Gustavo; Pipas, James M.

    2011-01-01

    The retinoblastoma tumor suppressor (pRb) regulates cell cycle entry, progression and exit by controlling the activity of the E2F-family of transcription factors. During cell cycle exit pRb acts as a transcriptional repressor by associating with E2F proteins and thereby inhibiting their ability to stimulate the expression of genes required for S phase. Indeed, many tumors harbor mutations in the RB gene and the pRb-E2F pathway is compromised in nearly all types of cancers. In this report we show that both pRb and its interacting partners, the transcriptional factors E2F1-2-3, act as positive modulators of detoxification pathways important for metabolizing and clearing xenobiotics—such as toxins and drugs—from the body. Using a combination of conventional molecular biology techniques and microarray analysis of specific cell populations, we have analyzed the detoxification pathway in murine samples in the presence or absence of pRb and/or E2F1-2-3. In this report, we show that both pRb and E2F1-2-3 act as positive modulators of detoxification pathways in mice, challenging the conventional view of E2F1-2-3 as transcriptional repressors negatively regulated by pRb. These results suggest that mutations altering the pRb-E2F axis may have consequences beyond loss of cell cycle control by altering the ability of tissues to remove toxins and to properly metabolize anticancer drugs, and might help to understand the formation and progression rates of different types of cancer, as well as to better design appropriate therapies based on the particular genetic composition of the tumors. PMID:22022495

  16. A Novel Cryptic Three-Way Translocation t(2;9;18(p23.2;p21.3;q21.33 with Deletion of Tumor Suppressor Genes in 9p21.3 and 13q14 in a T-Cell Acute Lymphoblastic Leukemia

    Directory of Open Access Journals (Sweden)

    Moneeb A. K. Othman

    2014-01-01

    Full Text Available Acute leukemia often presents with pure chromosomal resolution; thus, aberrations may not be detected by banding cytogenetics. Here, a case of 26-year-old male diagnosed with T-cell acute lymphoblastic leukemia (T-ALL and a normal karyotype after standard GTG-banding was studied retrospectively in detail by molecular cytogenetic and molecular approaches. Besides fluorescence in situ hybridization (FISH, multiplex ligation-dependent probe amplification (MLPA and high resolution array-comparative genomic hybridization (aCGH were applied. Thus, cryptic chromosomal aberrations not observed before were detected: three chromosomes were involved in a cytogenetically balanced occurring translocation t(2;9;18(p23.2;p21.3;q21.33. Besides a translocation t(10;14(q24;q11 was identified, an aberration known to be common in T-ALL. Due to the three-way translocation deletion of tumor suppressor genes CDKN2A/INK4A/p16, CDKN2B/INK4B/p15, and MTAP/ARF/p14 in 9p21.3 took place. Additionally RB1 in 13q14 was deleted. This patient, considered to have a normal karyotype after low resolution banding cytogenetics, was treated according to general protocol of anticancer therapy (ALL-BFM 95.

  17. Modulator of apoptosis 1 (MOAP-1) is a tumor suppressor protein linked to the RASSF1A protein.

    Science.gov (United States)

    Law, Jennifer; Salla, Mohamed; Zare, Alaa; Wong, Yoke; Luong, Le; Volodko, Natalia; Svystun, Orysya; Flood, Kayla; Lim, Jonathan; Sung, Miranda; Dyck, Jason R B; Tan, Chong Teik; Su, Yu-Chin; Yu, Victor C; Mackey, John; Baksh, Shairaz

    2015-10-02

    Modulator of apoptosis 1 (MOAP-1) is a BH3-like protein that plays key roles in cell death or apoptosis. It is an integral partner to the tumor suppressor protein, Ras association domain family 1A (RASSF1A), and functions to activate the Bcl-2 family pro-apoptotic protein Bax. Although RASSF1A is now considered a bona fide tumor suppressor protein, the role of MOAP-1 as a tumor suppressor protein has yet to be determined. In this study, we present several lines of evidence from cancer databases, immunoblotting of cancer cells, proliferation, and xenograft assays as well as DNA microarray analysis to demonstrate the role of MOAP-1 as a tumor suppressor protein. Frequent loss of MOAP-1 expression, in at least some cancers, appears to be attributed to mRNA down-regulation and the rapid proteasomal degradation of MOAP-1 that could be reversed utilizing the proteasome inhibitor MG132. Overexpression of MOAP-1 in several cancer cell lines resulted in reduced tumorigenesis and up-regulation of genes involved in cancer regulatory pathways that include apoptosis (p53, Fas, and MST1), DNA damage control (poly(ADP)-ribose polymerase and ataxia telangiectasia mutated), those within the cell metabolism (IR-α, IR-β, and AMP-activated protein kinase), and a stabilizing effect on microtubules. The loss of RASSF1A (an upstream regulator of MOAP-1) is one of the earliest detectable epigenetically silenced tumor suppressor proteins in cancer, and we speculate that the additional loss of function of MOAP-1 may be a second hit to functionally compromise the RASSF1A/MOAP-1 death receptor-dependent pathway and drive tumorigenesis. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. Modulator of Apoptosis 1 (MOAP-1) Is a Tumor Suppressor Protein Linked to the RASSF1A Protein*

    Science.gov (United States)

    Law, Jennifer; Salla, Mohamed; Zare, Alaa; Wong, Yoke; Luong, Le; Volodko, Natalia; Svystun, Orysya; Flood, Kayla; Lim, Jonathan; Sung, Miranda; Dyck, Jason R. B.; Tan, Chong Teik; Su, Yu-Chin; Yu, Victor C.; Mackey, John; Baksh, Shairaz

    2015-01-01

    Modulator of apoptosis 1 (MOAP-1) is a BH3-like protein that plays key roles in cell death or apoptosis. It is an integral partner to the tumor suppressor protein, Ras association domain family 1A (RASSF1A), and functions to activate the Bcl-2 family pro-apoptotic protein Bax. Although RASSF1A is now considered a bona fide tumor suppressor protein, the role of MOAP-1 as a tumor suppressor protein has yet to be determined. In this study, we present several lines of evidence from cancer databases, immunoblotting of cancer cells, proliferation, and xenograft assays as well as DNA microarray analysis to demonstrate the role of MOAP-1 as a tumor suppressor protein. Frequent loss of MOAP-1 expression, in at least some cancers, appears to be attributed to mRNA down-regulation and the rapid proteasomal degradation of MOAP-1 that could be reversed utilizing the proteasome inhibitor MG132. Overexpression of MOAP-1 in several cancer cell lines resulted in reduced tumorigenesis and up-regulation of genes involved in cancer regulatory pathways that include apoptosis (p53, Fas, and MST1), DNA damage control (poly(ADP)-ribose polymerase and ataxia telangiectasia mutated), those within the cell metabolism (IR-α, IR-β, and AMP-activated protein kinase), and a stabilizing effect on microtubules. The loss of RASSF1A (an upstream regulator of MOAP-1) is one of the earliest detectable epigenetically silenced tumor suppressor proteins in cancer, and we speculate that the additional loss of function of MOAP-1 may be a second hit to functionally compromise the RASSF1A/MOAP-1 death receptor-dependent pathway and drive tumorigenesis. PMID:26269600

  19. RASSF6; the Putative Tumor Suppressor of the RASSF Family

    Directory of Open Access Journals (Sweden)

    Hiroaki Iwasa

    2015-12-01

    Full Text Available Humans have 10 genes that belong to the Ras association (RA domain family (RASSF. Among them, RASSF7 to RASSF10 have the RA domain in the N-terminal region and are called the N-RASSF proteins. In contradistinction to them, RASSF1 to RASSF6 are referred to as the C-RASSF proteins. The C-RASSF proteins have the RA domain in the middle region and the Salvador/RASSF/Hippo domain in the C-terminal region. RASSF6 additionally harbors the PSD-95/Discs large/ZO-1 (PDZ-binding motif. Expression of RASSF6 is epigenetically suppressed in human cancers and is generally regarded as a tumor suppressor. RASSF6 induces caspase-dependent and -independent apoptosis. RASSF6 interacts with mammalian Ste20-like kinases (homologs of Drosophila Hippo and cross-talks with the Hippo pathway. RASSF6 binds MDM2 and regulates p53 expression. The interactions with Ras and Modulator of apoptosis 1 (MOAP1 are also suggested by heterologous protein-protein interaction experiments. RASSF6 regulates apoptosis and cell cycle through these protein-protein interactions, and is implicated in the NF-κB and JNK signaling pathways. We summarize our current knowledge about RASSF6 and discuss what common and different properties RASSF6 and the other C-RASSF proteins have.

  20. Epigenetic silencing of tumor suppressor genes: Paradigms, puzzles, and potential.

    Science.gov (United States)

    Kazanets, Anna; Shorstova, Tatiana; Hilmi, Khalid; Marques, Maud; Witcher, Michael

    2016-04-01

    Cancer constitutes a set of diseases with heterogeneous molecular pathologies. However, there are a number of universal aberrations common to all cancers, one of these being the epigenetic silencing of tumor suppressor genes (TSGs). The silencing of TSGs is thought to be an early, driving event in the oncogenic process. With this in consideration, great efforts have been made to develop small molecules aimed at the restoration of TSGs in order to limit tumor cell proliferation and survival. However, the molecular forces that drive the broad epigenetic reprogramming and transcriptional repression of these genes remain ill-defined. Undoubtedly, understanding the molecular underpinnings of transcriptionally silenced TSGs will aid us in our ability to reactivate these key anti-cancer targets. Here, we describe what we consider to be the five most logical molecular mechanisms that may account for this widely observed phenomenon: 1) ablation of transcription factor binding, 2) overexpression of DNA methyltransferases, 3) disruption of CTCF binding, 4) elevation of EZH2 activity, 5) aberrant expression of long non-coding RNAs. The strengths and weaknesses of each proposed mechanism is highlighted, followed by an overview of clinical efforts to target these processes. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  1. RASSF6; the Putative Tumor Suppressor of the RASSF Family.

    Science.gov (United States)

    Iwasa, Hiroaki; Jiang, Xinliang; Hata, Yutaka

    2015-12-09

    Humans have 10 genes that belong to the Ras association (RA) domain family (RASSF). Among them, RASSF7 to RASSF10 have the RA domain in the N-terminal region and are called the N-RASSF proteins. In contradistinction to them, RASSF1 to RASSF6 are referred to as the C-RASSF proteins. The C-RASSF proteins have the RA domain in the middle region and the Salvador/RASSF/Hippo domain in the C-terminal region. RASSF6 additionally harbors the PSD-95/Discs large/ZO-1 (PDZ)-binding motif. Expression of RASSF6 is epigenetically suppressed in human cancers and is generally regarded as a tumor suppressor. RASSF6 induces caspase-dependent and -independent apoptosis. RASSF6 interacts with mammalian Ste20-like kinases (homologs of Drosophila Hippo) and cross-talks with the Hippo pathway. RASSF6 binds MDM2 and regulates p53 expression. The interactions with Ras and Modulator of apoptosis 1 (MOAP1) are also suggested by heterologous protein-protein interaction experiments. RASSF6 regulates apoptosis and cell cycle through these protein-protein interactions, and is implicated in the NF-κB and JNK signaling pathways. We summarize our current knowledge about RASSF6 and discuss what common and different properties RASSF6 and the other C-RASSF proteins have.

  2. ARS2 is a general suppressor of pervasive transcription.

    Science.gov (United States)

    Iasillo, Claudia; Schmid, Manfred; Yahia, Yousra; Maqbool, Muhammad A; Descostes, Nicolas; Karadoulama, Evdoxia; Bertrand, Edouard; Andrau, Jean-Christophe; Jensen, Torben Heick

    2017-09-29

    Termination of transcription is important for establishing gene punctuation marks. It is also critical for suppressing many of the pervasive transcription events occurring throughout eukaryotic genomes and coupling their RNA products to efficient decay. In human cells, the ARS2 protein has been implicated in such function as its depletion causes transcriptional read-through of selected gene terminators and because it physically interacts with the ribonucleolytic nuclear RNA exosome. Here, we study the role of ARS2 on transcription and RNA metabolism genome wide. We show that ARS2 depletion negatively impacts levels of promoter-proximal RNA polymerase II at protein-coding (pc) genes. Moreover, our results reveal a general role of ARS2 in transcription termination-coupled RNA turnover at short transcription units like snRNA-, replication-dependent histone-, promoter upstream transcript- and enhancer RNA-loci. Depletion of the ARS2 interaction partner ZC3H18 mimics the ARS2 depletion, although to a milder extent, whereas depletion of the exosome core subunit RRP40 only impacts RNA abundance post-transcriptionally. Interestingly, ARS2 is also involved in transcription termination events within first introns of pc genes. Our work therefore establishes ARS2 as a general suppressor of pervasive transcription with the potential to regulate pc gene expression. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  3. Inhibitor of differentiation 4 (Id4 is a potential tumor suppressor in prostate cancer

    Directory of Open Access Journals (Sweden)

    Carey Jason PW

    2009-06-01

    Full Text Available Abstract Background Inhibitor of differentiation 4 (Id4, a member of the Id gene family is also a dominant negative regulator of basic helix loop helix (bHLH transcription factors. Some of the functions of Id4 appear to be unique as compared to its other family members Id1, Id2 and Id3. Loss of Id4 gene expression in many cancers in association with promoter hypermethylation has led to the proposal that Id4 may act as a tumor suppressor. In this study we provide functional evidence that Id4 indeed acts as a tumor suppressor and is part of a cancer associated epigenetic re-programming. Methods Data mining was used to demonstrate Id4 expression in prostate cancer. Methylation specific polymerase chain reaction (MSP analysis was performed to understand molecular mechanisms associated with Id4 expression in prostate cancer cell lines. The effect of ectopic Id4 expression in DU145 cells was determined by cell cycle analysis (3H thymidine incorporation and FACS, expression of androgen receptor, p53 and cyclin dependent kinase inhibitors p27 and p21 by a combination of RT-PCR, real time-PCR, western blot and immuno-cytochemical analysis. Results Id4 expression was down-regulated in prostate cancer. Id4 expression was also down-regulated in prostate cancer line DU145 due to promoter hyper-methylation. Ectopic Id4 expression in DU145 prostate cancer cell line led to increased apoptosis and decreased cell proliferation due in part by an S-phase arrest. In addition to S-phase arrest, ectopic Id4 expression in PC3 cells also resulted in prolonged G2/M phase. At the molecular level these changes were associated with increased androgen receptor (AR, p21, p27 and p53 expression in DU145 cells. Conclusion The results suggest that Id4 acts directly as a tumor suppressor by influencing a hierarchy of cellular processes at multiple levels that leads to a decreased cell proliferation and change in morphology that is possibly mediated through induction of previously

  4. KF-1 ubiquitin ligase: anxiety suppressor model.

    Science.gov (United States)

    Hashimoto-Gotoh, Tamotsu; Iwabe, Naoyuki; Tsujimura, Atsushi; Nakagawa, Masanori; Marunaka, Yoshinori

    2011-06-01

    Anxiety disorders are the most popular psychiatric disease in any human societies irrespective of nation, culture, religion, economics or politics. Anxiety expression mediated by the amygdala may be suppressed by signals transmitted from the prefrontal cortex and hippocampus. KF-1 is an endoplasmic reticulum (ER)-based E3-ubiquitin (Ub) ligase with a RING-H2 finger motif at the C-terminus. The kf-1 gene expression is up-regulated in the frontal cortex and hippocampus in rats after anti-depressant treatments. The kf-1 null mice show no apparent abnormalities, but exhibit selectively pronounced anxiety-like behaviors or increased timidity-like responses. The kf-1 orthologous genes had been generated after the Poriferan emergence, and are found widely in all animals except insects, arachnids and threadworms such as Drosophila, Ixodes and Caenorhabditis, respectively. This suggests that the kf-1 gene may be relevant to some biological functions characteristic to animals. Based on these observations, the Anxiety Suppressor Model has been proposed, which assumes that KF-1 Ub ligase may suppress the amygdala-mediated anxiety by degrading some anxiety promoting protein(s), such as a neurotransmitter receptor, through the ER-associated degradation pathway in the frontal cortex and hippocampus. According to this model, the emotional sensitivity to environmental stresses may be regulated by the cellular protein level of KF-1 relative to that of the putative anxiety promoter. The kf-1 null mice should be useful in elucidating the molecular mechanisms of the anxiety regulation and for screening novel anxiolytic compounds, which may block the putative anxiety promoter.

  5. A single mutation in the 15S rRNA gene confers nonsense suppressor activity and interacts with mRF1 the release factor in yeast mitochondria

    Directory of Open Access Journals (Sweden)

    Ali Gargouri

    2015-08-01

    Full Text Available We have determined the nucleotide sequence of the mim3-1 mitochondrial ribosomal suppressor, acting on ochre mitochondrial mutations and one frameshift mutation in Saccharomyces cerevisiae. The 15s rRNA suppressor gene contains a G633 to C transversion. Yeast mitochondrial G633 corresponds to G517 of the E.coli 15S rRNA, which is occupied by an invariant G in all known small rRNA sequences. Interestingly, this mutation has occurred at the same position as the known MSU1 mitochondrial suppressor which changes G633 to A. The suppressor mutation lies in a highly conserved region of the rRNA, known in E.coli as the 530-loop, interacting with the S4, S5 and S12 ribosomal proteins. We also show an interesting interaction between the mitochondrial mim3-1 and the nuclear nam3-1 suppressors, both of which have the same action spectrum on mitochondrial mutations: nam3-1 abolishes the suppressor effect when present with mim3-1 in the same haploid cell. We discuss these results in the light of the nature of Nam3, identified by [1] as the yeast mitochondrial translation release factor. A hypothetical mechanism of suppression by "ribosome shifting" is also discussed in view of the nature of mutations suppressed and not suppressed.

  6. Identification of a third protein 4.1 tumor suppressor, protein 4.1R, in meningioma pathogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Robb, Victoria A.; Li, Wen; Gascard, Philippe; Perry, Arie; Mohandas, Narla; Gutmann, David H.

    2003-06-11

    Meningiomas are common tumors of the central nervous system, however, the mechanisms under lying their pathogenesis are largely undefined. Two members of the Protein 4.1 super family, the neuro fibromatosis 2 (NF2) gene product (merlin/schwannomin) and Protein 4.1B have been implicated as meningioma tumor suppressors. In this report, we demonstrate that another Protein 4.1 family member, Protein 4.1R, also functions as a meningioma tumor suppressor. Based on the assignment of the Protein 4.1R gene to chromosome 1p32-36, a common region of deletion observed in meningiomas, we analyzed Protein 4.1R expression in meningioma cell lines and surgical tumor specimens. We observed loss of Protein 4.1R protein expression in two meningioma cell lines (IOMM-Lee, CH157-MN) by Western blotting as well as in 6 of 15 sporadic meningioma as by immuno histo chemistry (IHC). Analysis of a subset of these sporadic meningiomas by fluorescent in situ hybridization (FISH) with a Protein 4.1R specific probe demonstrated 100 percent concordance with the IHC results. In support of a meningioma tumor suppressor function, over expression of Protein 4.1R resulted in suppression of IOMM-Lee and CH157MN cell proliferation. Similar to the Protein 4.1B and merlin meningioma tumor suppressors, Protein 4.1R localization in the membrane fraction increased significantly under conditions of growth arrest in vitro. Lastly, Protein 4.1R interacted with some known merlin/Protein 4.1B interactors such as CD44 and bII-spectrin, but did not associate with the Protein 4.1B interactors 14-3-3 and PRMT3 or the merlin binding proteins SCHIP-1 and HRS. Collectively, these results suggest that Protein 4.1R functions as an important tumor suppressor important in the molecular pathogenesis of meningioma.

  7. Using Yeast to Determine the Functional Consequences of Mutations in the Human p53 Tumor Suppressor Gene: An Introductory Course-Based Undergraduate Research Experience in Molecular and Cell Biology

    Science.gov (United States)

    Hekmat-Scafe, Daria S.; Brownell, Sara E.; Seawell, Patricia Chandler; Malladi, Shyamala; Imam, Jamie F. Conklin; Singla, Veena; Bradon, Nicole; Cyert, Martha S.; Stearns, Tim

    2017-01-01

    The opportunity to engage in scientific research is an important, but often neglected, component of undergraduate training in biology. We describe the curriculum for an innovative, course-based undergraduate research experience (CURE) appropriate for a large, introductory cell and molecular biology laboratory class that leverages students' high…

  8. Src Inhibits the Hippo Tumor Suppressor Pathway through Tyrosine Phosphorylation of Lats1.

    Science.gov (United States)

    Si, Yuan; Ji, Xinyan; Cao, Xiaolei; Dai, Xiaoming; Xu, Lingyi; Zhao, Hongxia; Guo, Xiaocan; Yan, Huan; Zhang, Haitao; Zhu, Chu; Zhou, Qi; Tang, Mei; Xia, Zongping; Li, Li; Cong, Yu-Sheng; Ye, Sheng; Liang, Tingbo; Feng, Xin-Hua; Zhao, Bin

    2017-09-15

    The Hippo pathway regulates cell proliferation, apoptosis, and stem cell self-renewal, and its inactivation in animal models causes organ enlargement followed by tumorigenesis. Hippo pathway deregulation occurs in many human cancers, but the underlying mechanisms are not fully understood. Here, we report tyrosine phosphorylation of the Hippo pathway tumor suppressor LATS1 as a mechanism underlying its regulation by cell adhesion. A tyrosine kinase library screen identified Src as the kinase to directly phosphorylate LATS1 on multiple residues, causing attenuated Mob kinase activator binding and structural alteration of the substrate-binding pocket in the kinase domain. Cell matrix adhesion activated the Hippo pathway effector transcription coactivator YAP partially through Src-mediated phosphorylation and inhibition of LATS1. Aberrant Src activation abolished the tumor suppressor activity of LATS1 and induced tumorigenesis in a YAP-dependent manner. Protein levels of Src in human breast cancer tissues correlated with accumulation of active YAP dephosphorylated on the LATS1 target site. These findings reveal tyrosine phosphorylation of LATS1 by Src as a novel mechanism of Hippo pathway regulation by cell adhesion and suggest Src activation as an underlying reason for YAP deregulation in tumorigenesis. Cancer Res; 77(18); 4868-80. ©2017 AACR . ©2017 American Association for Cancer Research.

  9. Mutations Blocking Side Chain Assembly, Polymerization, or Transport of a Wzy-Dependent Streptococcus pneumoniae Capsule Are Lethal in the Absence of Suppressor Mutations and Can Affect Polymer Transfer to the Cell Wall▿

    OpenAIRE

    Xayarath, Bobbi; Yother, Janet

    2007-01-01

    Extracellular polysaccharides of many bacteria are synthesized by the Wzy polymerase-dependent mechanism, where long-chain polymers are assembled from undecaprenyl-phosphate-linked repeat units on the outer face of the cytoplasmic membrane. In gram-positive bacteria, Wzy-dependent capsules remain largely cell associated via membrane and peptidoglycan linkages. Like many Wzy-dependent capsules, the Streptococcus pneumoniae serotype 2 capsule is branched. In this study, we found that deletions ...

  10. Structure of the Wilms Tumor Suppressor

    Energy Technology Data Exchange (ETDEWEB)

    Stoll, R.; Lee, B.M.; Debler, E.W.; Laity, J.H.; Wilson, I.A.; Dyson, H.J.; Wright, P.E.

    2009-06-04

    The zinc finger domain of the Wilms tumor suppressor protein (WT1) contains four canonical Cys{sub 2}His{sub 2} zinc fingers. WT1 binds preferentially to DNA sequences that are closely related to the EGR-1 consensus site. We report the structure determination by both X-ray crystallography and NMR spectroscopy of the WT1 zinc finger domain in complex with DNA. The X-ray structure was determined for the complex with a cognate 14 base-pair oligonucleotide, and composite X-ray/NMR structures were determined for complexes with both the 14 base-pair and an extended 17 base-pair DNA. This combined approach allowed unambiguous determination of the position of the first zinc finger, which is influenced by lattice contacts in the crystal structure. The crystal structure shows the second, third and fourth zinc finger domains inserted deep into the major groove of the DNA where they make base-specific interactions. The DNA duplex is distorted in the vicinity of the first zinc finger, with a cytidine twisted and tilted out of the base stack to pack against finger 1 and the tip of finger 2. By contrast, the composite X-ray/NMR structures show that finger 1 continues to follow the major groove in the solution complexes. However, the orientation of the helix is non-canonical, and the fingertip and the N terminus of the helix project out of the major groove; as a consequence, the zinc finger side-chains that are commonly involved in base recognition make no contact with the DNA. We conclude that finger 1 helps to anchor WT1 to the DNA by amplifying the binding affinity although it does not contribute significantly to binding specificity. The structures provide molecular level insights into the potential consequences of mutations in zinc fingers 2 and 3 that are associated with Denys-Drash syndrome and nephritic syndrome. The mutations are of two types, and either destabilize the zinc finger structure or replace key base contact residues.

  11. The tumor suppressor Rb and its related Rbl2 genes are regulated by Utx histone demethylase

    Energy Technology Data Exchange (ETDEWEB)

    Terashima, Minoru; Ishimura, Akihiko; Yoshida, Masakazu [Division of Functional Genomics, Cancer Research Institute, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Ishikawa (Japan); Suzuki, Yutaka; Sugano, Sumio [Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8561, Chiba (Japan); Suzuki, Takeshi, E-mail: suzuki-t@staff.kanazawa-u.ac.jp [Division of Functional Genomics, Cancer Research Institute, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Ishikawa (Japan)

    2010-08-20

    Research highlights: {yields} Utx increases expression of Rb and Rbl2 genes through its demethylase activity. {yields} Utx changes histone H3 methylation on the Rb and Rbl2 promoters. {yields} Utx induces decreased cell proliferation of mammalian primary cells. -- Abstract: Utx is a candidate tumor suppressor gene that encodes histone H3 lysine 27 (H3K27) demethylase. In this study, we found that ectopic expression of Utx enhanced the expression of retinoblastoma tumor suppressor gene Rb and its related gene Rbl2. This activation was dependent on the demethylase activity of Utx, and was suggested to contribute to the decreased cell proliferation induced by Utx. A chromatin immunoprecipitation assay showed that over-expressed Utx was associated with the promoter regions of Rb and Rbl2 resulting in the removal of repressive H3K27 tri-methylation and the increase in active H3K4 tri-methylation. Furthermore, siRNA-mediated knockdown of Utx revealed the recruitment of endogenous Utx protein on the promoters of Rb and Rbl2 genes. These results indicate that Rb and Rbl2 are downstream target genes of Utx and may play important roles in Utx-mediated cell growth control.

  12. Unexpected functional similarities between gatekeeper tumour suppressor genes and proto-oncogenes revealed by systems biology.

    Science.gov (United States)

    Zhao, Yongzhong; Epstein, Richard J

    2011-05-01

    Familial tumor suppressor genes comprise two subgroups: caretaker genes (CTs) that repair DNA, and gatekeeper genes (GKs) that trigger cell death. Since GKs may also induce cell cycle delay and thus enhance cell survival by facilitating DNA repair, we hypothesized that the prosurvival phenotype of GKs could be selected during cancer progression, and we used a multivariable systems biology approach to test this. We performed multidimensional data analysis, non-negative matrix factorization and logistic regression to compare the features of GKs with those of their putative antagonists, the proto-oncogenes (POs), as well as with control groups of CTs and functionally unrelated congenital heart disease genes (HDs). GKs and POs closely resemble each other, but not CTs or HDs, in terms of gene structure (Pexpression level and breadth (Pimplied suggest a common functional attribute that is strongly negatively selected-that is, a shared phenotype that enhances cell survival. The counterintuitive finding of similar evolutionary pressures affecting GKs and POs raises an intriguing possibility: namely, that cancer microevolution is accelerated by an epistatic cascade in which upstream suppressor gene defects subvert the normal bifunctionality of wild-type GKs by constitutively shifting the phenotype away from apoptosis towards survival. If correct, this interpretation would explain the hitherto unexplained phenomenon of frequent wild-type GK (for example, p53) overexpression in tumors.

  13. Active suppression of host-vs-graft reaction in pregnant mice. VI. Soluble suppressor activity obtained from decidua of allopregnant mice blocks the response to IL 2.

    Science.gov (United States)

    Clark, D A; Chaput, A; Walker, C; Rosenthal, K L

    1985-03-01

    The mammalian fetus expresses a variety of antigens against which the maternal immune system can react and which in an allogeneic mating bears paternal transplantation antigens. Although these antigens may be expressed on the fetal trophoblast cells that contact maternal uterine decidua, the "fetal allograft" is not usually rejected. Previous studies have demonstrated the presence of nonspecific non-thymus-derived suppressor cells in the lymph nodes draining the uterus and in decidua of laboratory mice undergoing first allogeneic pregnancy. These suppressor cells appeared to be small lymphocyte cells that inhibit the generation of cytotoxic T lymphocytes (CTL) in vitro and in vivo and elaborate a nonspecific non-MHC-restricted soluble suppressor activity when cultured for 48 hours at 37 degrees C in vitro. We now report that soluble suppressor activity obtained from the decidua (DS) of allopregnant C3H/HeJ mice inhibits both the primary and secondary (memory) CTL response in vitro but does not inhibit lysis of target cells by preformed CTL. DS did not suppress the proliferation of YAC lymphoma cells, P-815 cells, or a C3H placental trophoblastoma line. Suppressor activity was obtained from anti-thy-1.2 + complement-resistant cells in the decidua, could also be obtained from the decidua of allopregnant CD1 nu/nu mice, and was associated with a single peak of activity of approximately 100,000 daltons on Sephacryl 200 chromatography. Suppression could not be overcome by adding either crude or HPLC-purified IL 2 to the mixed lymphocyte cultures in vitro, and both crude and column-purified suppressor factor inhibited the IL 2-dependent proliferation of H-Y cells (a cloned T cell line with NK activity). Furthermore, DS inhibited the IL 2-dependent generation of cytotoxic effector cells in vitro in the absence of allogeneic stimulator cells. Thus, a soluble suppressor factor obtained from non-T cells present in the decidua of successfully allopregnant mice could block the

  14. Remodeling epigenetic modifications at tumor suppressor gene promoters with bovine oocyte extract.

    Science.gov (United States)

    Wang, Zhenfei; Yue, Yongli; Han, Pengyong; Sa, Rula; Ren, Xiaolv; Wang, Jie; Bai, Haidong; Yu, Haiquan

    2013-09-01

    Epigenetic silencing of tumor suppressor genes by aberrant DNA methylation and histone modifications at their promoter regions plays an important role in the initiation and progression of cancer. The therapeutic effect of the widely used epigenetic drugs, including DNA methyltransferase inhibitors and histone deacetylase inhibitors, remains unsatisfactory. One important underlying factor in the ineffectiveness of these drugs is that their actions lack specificity. To investigate whether oocyte extract can be used for epigenetic re-programming of cancer cells, H460 human lung cancer cells were reversibly permeabilized and incubated with bovine oocyte extract. Bisulfite sequencing showed that bovine oocyte extract induced significant demethylation at hypermethylated promoter CpG islands of the tumor suppressor genes RUNX3 and CDH1; however, the DNA methylation levels of repetitive sequences were not affected. Chromatin immunoprecipitation showed that bovine oocyte extract significantly reduced transcriptionally repressive histone modifications and increased transcriptionally activating histone modifications at the promoter regions of RUNX3 and CDH1. Bovine oocyte extract reactivated the expression of RUNX3 and CDH1 at both the messenger RNA and the protein levels without up-regulating the transcription of pluripotency-associated genes. At the functional level, anchorage-independent proliferation, migration and invasion of H460 cells was strongly inhibited. These results demonstrate that bovine oocyte extract reactivates epigenetically silenced tumor suppressor genes by remodeling the epigenetic modifications at their promoter regions. Bovine oocyte extract may provide a useful tool for investigating epigenetic mechanisms in cancer and a valuable source for developing novel safe therapeutic approaches that target epigenetic alterations. Copyright © 2013 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

  15. PTEN functions as a melanoma tumor suppressor by promoting host immune response.

    Science.gov (United States)

    Dong, Y; Richards, J-Ae; Gupta, R; Aung, P P; Emley, A; Kluger, Y; Dogra, S K; Mahalingam, M; Wajapeyee, N

    2014-09-18

    Cancer cells acquire several traits that allow for their survival and progression, including the ability to evade the host immune response. However, the mechanisms by which cancer cells evade host immune responses remain largely elusive. Here we study the phenomena of immune evasion in malignant melanoma cells. We find that the tumor suppressor phosphatase and tensin homolog (PTEN) is an important regulator of the host immune response against melanoma cells. Mechanistically, PTEN represses the expression of immunosuppressive cytokines by blocking the phosphatidylinositide 3-kinase (PI3K) pathway. In melanoma cells lacking PTEN, signal transducer and activator of transcription 3 activates the transcription of immunosuppressive cytokines in a PI3K-dependent manner. Furthermore, conditioned media from PTEN-deficient, patient-derived short-term melanoma cultures and established melanoma cell lines blocked the production of the interleukin-12 (IL-12) in human monocyte-derived dendritic cells. Inhibition of IL-12 production was rescued by restoring PTEN or using neutralizing antibodies against the immunosuppressive cytokines. Furthermore, we report that PTEN, as an alternative mechanism to promote the host immune response against cancer cells, represses the expression of programmed cell death 1 ligand, a known repressor of the host immune response. Finally, to establish the clinical significance of our results, we analyzed malignant melanoma patient samples with or without brisk host responses. These analyses confirmed that PTEN loss is associated with a higher percentage of malignant melanoma samples with non-brisk host responses compared with samples with brisk host responses. Collectively, these results establish that PTEN functions as a melanoma tumor suppressor in part by regulating the host immune response against melanoma cells and highlight the importance of assessing PTEN status before recruiting melanoma patients for immunotherapies.

  16. Firearm suppressor having enhanced thermal management for rapid heat dissipation

    Science.gov (United States)

    Moss, William C.; Anderson, Andrew T.

    2014-08-19

    A suppressor is disclosed for use with a weapon having a barrel through which a bullet is fired. The suppressor has an inner portion having a bore extending coaxially therethrough. The inner portion is adapted to be secured to a distal end of the barrel. A plurality of axial flow segments project radially from the inner portion and form axial flow paths through which expanding propellant gasses discharged from the barrel flow through. The axial flow segments have radially extending wall portions that define sections which may be filled with thermally conductive material, which in one example is a thermally conductive foam. The conductive foam helps to dissipate heat deposited within the suppressor during firing of the weapon.

  17. Wilms' tumours: about tumour suppressor genes, an oncogene and a chameleon gene.

    Science.gov (United States)

    Huff, Vicki

    2011-02-01

    Genes identified as being mutated in Wilms' tumour include TP53, a classic tumour suppressor gene (TSG); CTNNB1 (encoding β-catenin), a classic oncogene; WTX, which accumulating data indicate is a TSG; and WT1, which is inactivated in some Wilms' tumours, similar to a TSG. However, WT1 does not always conform to the TSG label, and some data indicate that WT1 enhances cell survival and proliferation, like an oncogene. Is WT1 a chameleon, functioning as either a TSG or an oncogene, depending on cellular context? Are these labels even appropriate for describing and understanding the function of WT1?

  18. Tumour suppressor genes in sporadic epithelial ovarian cancer

    DEFF Research Database (Denmark)

    Liu, Ying; Ganesan, Trivadi S

    2002-01-01

    Ovarian cancer is the most frequent cause of death from gynaecological malignancies in the western world, and sporadic epithelial ovarian cancer is its most predominant form. The aetiology of sporadic ovarian cancer remains unknown. Genetic studies have enabled a better understanding...... of the evolution of tumour progression. A major focus of research has been to identify tumour suppressor genes implicated in sporadic ovarian cancer over the past decade. Several tumour suppressor genes have been identified by strategies such as positional cloning and differential expression display. Further...... research is warranted to understand fully their contribution to the pathogenesis of sporadic ovarian cancer....

  19. Synthetic lethal interaction between the tumour suppressor STAG2 and its paralog STAG1.

    Science.gov (United States)

    Benedetti, Lorena; Cereda, Matteo; Monteverde, LeeAnn; Desai, Nikita; Ciccarelli, Francesca D

    2017-06-06

    Cohesin is a multi-protein complex that tethers sister chromatids during mitosis and mediates DNA repair, genome compartmentalisation and regulation of gene expression. Cohesin subunits frequently acquire cancer loss-of-function alterations and act as tumour suppressors in several tumour types. This has led to increased interest in cohesin as potential target in anti-cancer therapy. Here we show that the loss-of-function of STAG2, a core component of cohesin and an emerging tumour suppressor, leads to synthetic dependency of mutated cancer cells on its paralog STAG1. STAG1 and STAG2 share high sequence identity, encode mutually exclusive cohesin subunits and retain partially overlapping functions. We inhibited STAG1 and STAG2 in several cancer cell lines where the two genes have variable mutation and copy number status. In all cases, we observed that the simultaneous blocking of STAG1 and STAG2 significantly reduces cell proliferation. We further confirmed the synthetic lethal interaction developing a vector-free CRISPR system to induce STAG1/STAG2 double gene knockout. We provide strong evidence that STAG1 is a promising therapeutic target in cancers with inactivating alterations of STAG2.

  20. Cancer-associated splicing variant of tumor suppressor AIMP2/p38: pathological implication in tumorigenesis.

    Directory of Open Access Journals (Sweden)

    Jin Woo Choi

    2011-03-01

    Full Text Available Although ARS-interacting multifunctional protein 2 (AIMP2, also named as MSC p38 was first found as a component for a macromolecular tRNA synthetase complex, it was recently discovered to dissociate from the complex and work as a potent tumor suppressor. Upon DNA damage, AIMP2 promotes apoptosis through the protective interaction with p53. However, it was not demonstrated whether AIMP2 was indeed pathologically linked to human cancer. In this work, we found that a splicing variant of AIMP2 lacking exon 2 (AIMP2-DX2 is highly expressed by alternative splicing in human lung cancer cells and patient's tissues. AIMP2-DX2 compromised pro-apoptotic activity of normal AIMP2 through the competitive binding to p53. The cells with higher level of AIMP2-DX2 showed higher propensity to form anchorage-independent colonies and increased resistance to cell death. Mice constitutively expressing this variant showed increased susceptibility to carcinogen-induced lung tumorigenesis. The expression ratio of AIMP2-DX2 to normal AIMP2 was increased according to lung cancer stage and showed a positive correlation with the survival of patients. Thus, this work identified an oncogenic splicing variant of a tumor suppressor, AIMP2/p38, and suggests its potential for anti-cancer target.