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Sample records for loddigesii suppresses tumor

  1. Comparison of photosynthesis and fluorescent parameters between Dendrobium officinale and Dendrobium loddigesii

    PubMed Central

    Sun, Zhi-Rong; Zhu, Nan-Nan; Cheng, Li-Li; Yang, Chun-Ning

    2015-01-01

    Objective: To investigate the photosynthesis and fluorescent parameters between Dendrobium officinale and Dendrobium loddigesii, based on which to provide helpful information for the artificial cultivation of these cultivars. Methods: Seeds were placed on the MS medium supplemented with 0.2 mg/L NAA, 2% (w/v) sucrose, 15% (v/v) potato extracts and powered agar (pH 5.8). Two months after germination, seedlings (n = 10) were transferred onto rooting medium containing MS medium supplemented with 0.5 mg/L NAA, 3% (w/v) sucrose, 20% (v/v) potato extracts and 1‰ (w/v) activated carbon (pH 5.8) in a glass bottle (6.5 cm in diameter and 9.5 cm in height) with a white transparent plastic cap. Chlorophyll content was determined using the UV-Vis spectrophotometric method. In addition, rates of oxygen evolution and uptake were measured. The chlorophyll fluorescence was determined at room temperature using PAM 2000 chlorophyll fluorometer (Heinz Walz GmbH, Germany). Results: From month 5 to month 10, the overall contents of both chlorophyll a and chlorophyll b were higher in D. loddigesii compared with those in D. officinale. No statistical differences were observed in the apparent photosynthetic rate (APR) between D. loddigesii and D. officinale. No statistical difference was noticed in the Fo, Fm and Fv between D. loddigesii and D. officinale (P > 0.05). Significant increase was noticed in the oxygen consuming in PSI in month-8 and month-10 compared with that of month-6 in D. loddigesii. Nevertheless, in the D. officinale, the oxygen consuming in PSI in month-6 was remarkably increased with those of month-8 and month-10, respectively. Conclusions: The photosynthesis and fluorescence parameters varied in the seedling of D. loddigesii and D. officinale. Such information could contribute to the artificial cultivation of these cultivars. PMID:26550239

  2. Immune suppressive mechanisms in the tumor microenvironment.

    PubMed

    Munn, David H; Bronte, Vincenzo

    2016-04-01

    Effective immunotherapy, whether by checkpoint blockade or adoptive cell therapy, is limited in most patients by a key barrier: the immunosuppressive tumor microenvironment. Suppression of tumor-specific T cells is orchestrated by the activity of a variety of stromal myeloid and lymphoid cells. These often display inducible suppressive mechanisms that are triggered by the same anti-tumor inflammatory response that the immunotherapy intends to create. Therefore, a more comprehensive understanding of how the immunosuppressive milieu develops and persists is critical in order to harness the full power of immunotherapy of cancer.

  3. Tumor suppression by stromal TIMPs.

    PubMed

    Shimoda, Masayuki; Jackson, Hartland W; Khokha, Rama

    2016-05-01

    The tumor stroma has the capacity to drive cancer progression, although the mechanisms governing these effects are incompletely understood. Recently, we reported that deletion of tissue inhibitor of metalloproteinases (Timps) in fibroblasts unleashes the function of cancer-associated fibroblasts and identifies a novel mode of stromal-tumor communication that activates key oncogenic pathways invoving Notch and ras homolog gene family, member A (RhoA) via stromal exosomes. PMID:27314104

  4. Autophagy in tumor Suppression and cancer therapy

    PubMed Central

    Kung, Che-Pei; Budina, Anna; Balaburski, Gregor; Bergenstock, Marika K.; Murphy, Maureen E.

    2011-01-01

    Autophagy is a stress-induced cell survival program whereby cells under metabolic, proteotoxic, or other stress remove dysfunctional organelles and/or misfolded/polyubiquitylated proteins by shuttling them via specialized structures called autophagosomes to the lysosome for degradation. The end result is the release of free amino acids and metabolites for use in cell survival. For tumor cells, autophagy is a double-edged sword: autophagy genes are frequently mono-allelically deleted, silenced, or mutated in human tumors, resulting in an environment of increased oxidative stress that is conducive to DNA damage, genomic instability, and tumor progression. As such, autophagy is tumor suppressive. In contrast, it is important to note that although tumor cells have reduced levels of autophagy, they do not eliminate this pathway completely. Furthermore, the exposure of tumor cells to an environment of increased metabolic and other stresses renders them reliant on basal autophagy for survival. Therefore, autophagy inhibition is an active avenue for the identification of novel anti-cancer therapies. Not surprisingly, the field of autophagy and cancer has experienced an explosion of research in the past 10 years. This review covers the basic mechanisms of autophagy, discusses its role in tumor suppression and cancer therapy, and posits emerging questions for the future. PMID:21967333

  5. Wnt5a Suppresses Tumor Formation and Redirects Tumor Phenotype in MMTV-Wnt1 Tumors

    PubMed Central

    Easter, Stephanie L.; Mitchell, Elizabeth H.; Baxley, Sarah E.; Desmond, Renee; Frost, Andra R.; Serra, Rosa

    2014-01-01

    Wnt5a is a non-canonical signaling Wnt that has been implicated in tumor suppression. We previously showed that loss of Wnt5a in MMTV-PyVmT tumors resulted in a switch in tumor phenotype resulting in tumors with increased basal phenotype and high Wnt/β-catenin signaling. The object of this study was to test the hypothesis that Wnt5a can act to inhibit tumors formed by activation of Wnt/β-catenin signaling. To this end, we characterized tumor and non-tumor mammary tissue from MMTV-Wnt1 and double transgenic MMTV-Wnt1;MMTV-Wnt5a mice. Wnt5a containing mice demonstrated fewer tumors with increased latency when compared to MMTV-Wnt1 controls. Expression of markers for basal-like tumors was down-regulated in the tumors that formed in the presence of Wnt5a indicating a phenotypic switch. Reduced canonical Wnt signaling was detected in double transgenic tumors as a decrease in active β-catenin protein and a decrease in Axin2 mRNA transcript levels. In non-tumor tissues, over-expression of Wnt5a in MMTV-Wnt1 mammary glands resulted in attenuation of phenotypes normally observed in MMTV-Wnt1 glands including hyperbranching and increased progenitor and basal cell populations. Even though Wnt5a could antagonize Wnt/β-catenin signaling in primary mammary epithelial cells in culture, reduced Wnt/β-catenin signaling was not detected in non-tumor MMTV-Wnt1;Wnt5a tissue in vivo. The data demonstrate that Wnt5a suppresses tumor formation and promotes a phenotypic shift in MMTV-Wnt1 tumors. PMID:25401739

  6. Wnt5a suppresses tumor formation and redirects tumor phenotype in MMTV-Wnt1 tumors.

    PubMed

    Easter, Stephanie L; Mitchell, Elizabeth H; Baxley, Sarah E; Desmond, Renee; Frost, Andra R; Serra, Rosa

    2014-01-01

    Wnt5a is a non-canonical signaling Wnt that has been implicated in tumor suppression. We previously showed that loss of Wnt5a in MMTV-PyVmT tumors resulted in a switch in tumor phenotype resulting in tumors with increased basal phenotype and high Wnt/β-catenin signaling. The object of this study was to test the hypothesis that Wnt5a can act to inhibit tumors formed by activation of Wnt/β-catenin signaling. To this end, we characterized tumor and non-tumor mammary tissue from MMTV-Wnt1 and double transgenic MMTV-Wnt1;MMTV-Wnt5a mice. Wnt5a containing mice demonstrated fewer tumors with increased latency when compared to MMTV-Wnt1 controls. Expression of markers for basal-like tumors was down-regulated in the tumors that formed in the presence of Wnt5a indicating a phenotypic switch. Reduced canonical Wnt signaling was detected in double transgenic tumors as a decrease in active β-catenin protein and a decrease in Axin2 mRNA transcript levels. In non-tumor tissues, over-expression of Wnt5a in MMTV-Wnt1 mammary glands resulted in attenuation of phenotypes normally observed in MMTV-Wnt1 glands including hyperbranching and increased progenitor and basal cell populations. Even though Wnt5a could antagonize Wnt/β-catenin signaling in primary mammary epithelial cells in culture, reduced Wnt/β-catenin signaling was not detected in non-tumor MMTV-Wnt1;Wnt5a tissue in vivo. The data demonstrate that Wnt5a suppresses tumor formation and promotes a phenotypic shift in MMTV-Wnt1 tumors.

  7. ARF tumor suppression in the nucleolus.

    PubMed

    Maggi, Leonard B; Winkeler, Crystal L; Miceli, Alexander P; Apicelli, Anthony J; Brady, Suzanne N; Kuchenreuther, Michael J; Weber, Jason D

    2014-06-01

    Since its discovery close to twenty years ago, the ARF tumor suppressor has played a pivotal role in the field of cancer biology. Elucidating ARF's basal physiological function in the cell has been the focal interest of numerous laboratories throughout the world for many years. Our current understanding of ARF is constantly evolving to include novel frameworks for conceptualizing the regulation of this critical tumor suppressor. As a result of this complexity, there is great need to broaden our understanding of the intricacies governing the biology of the ARF tumor suppressor. The ARF tumor suppressor is a key sensor of signals that instruct a cell to grow and proliferate and is appropriately localized in nucleoli to limit these processes. This article is part of a Special Issue entitled: Role of the Nucleolus in Human Disease.

  8. Tumor growth suppression by the combination of nanobubbles and ultrasound.

    PubMed

    Suzuki, Ryo; Oda, Yusuke; Omata, Daiki; Nishiie, Norihito; Koshima, Risa; Shiono, Yasuyuki; Sawaguchi, Yoshikazu; Unga, Johan; Naoi, Tomoyuki; Negishi, Yoichi; Kawakami, Shigeru; Hashida, Mitsuru; Maruyama, Kazuo

    2016-03-01

    We previously developed novel liposomal nanobubbles (Bubble liposomes [BL]) that oscillate and collapse in an ultrasound field, generating heat and shock waves. We aimed to investigate the feasibility of cancer therapy using the combination of BL and ultrasound. In addition, we investigated the anti-tumor mechanism of this cancer therapy. Colon-26 cells were inoculated into the flank of BALB/c mice to induce tumors. After 8 days, BL or saline was intratumorally injected, followed by transdermal ultrasound exposure of tumor tissue (1 MHz, 0-4 W/cm2 , 2 min). The anti-tumor effects were evaluated by histology (necrosis) and tumor growth. In vivo cell depletion assays were performed to identify the immune cells responsible for anti-tumor effects. Tumor temperatures were significantly higher when treated with BL + ultrasound than ultrasound alone. Intratumoral BL caused extensive tissue necrosis at 3-4 W/cm2 of ultrasound exposure. In addition, BL + ultrasound significantly suppressed tumor growth at 2-4 W/cm2 . In vivo depletion of CD8+ T cells (not NK or CD4+ T cells) completely blocked the effect of BL + ultrasound on tumor growth. These data suggest that CD8+ T cells play a critical role in tumor growth suppression. Finally, we concluded that BL + ultrasound, which can prime the anti-tumor cellular immune system, may be an effective hyperthermia strategy for cancer treatment.

  9. Tumor Suppression and Promotion by Autophagy

    PubMed Central

    Ávalos, Yenniffer; Canales, Jimena; Criollo, Alfredo; Quest, Andrew F. G.

    2014-01-01

    Autophagy is a highly regulated catabolic process that involves lysosomal degradation of proteins and organelles, mostly mitochondria, for the maintenance of cellular homeostasis and reduction of metabolic stress. Problems in the execution of this process are linked to different pathological conditions, such as neurodegeneration, aging, and cancer. Many of the proteins that regulate autophagy are either oncogenes or tumor suppressor proteins. Specifically, tumor suppressor genes that negatively regulate mTOR, such as PTEN, AMPK, LKB1, and TSC1/2 stimulate autophagy while, conversely, oncogenes that activate mTOR, such as class I PI3K, Ras, Rheb, and AKT, inhibit autophagy, suggesting that autophagy is a tumor suppressor mechanism. Consistent with this hypothesis, the inhibition of autophagy promotes oxidative stress, genomic instability, and tumorigenesis. Nevertheless, autophagy also functions as a cytoprotective mechanism under stress conditions, including hypoxia and nutrient starvation, that promotes tumor growth and resistance to chemotherapy in established tumors. Here, in this brief review, we will focus the discussion on this ambiguous role of autophagy in the development and progression of cancer. PMID:25328887

  10. Tumor suppression by resistant maltodextrin, Fibersol-2.

    PubMed

    So, Eui Young; Ouchi, Mutsuko; Cuesta-Sancho, Sara; Olson, Susan Losee; Reif, Dirk; Shimomura, Kazuhiro; Ouchi, Toru

    2015-01-01

    Resistant maltodextrin Fibersol-2 is a soluble and fermentable dietary fiber that is Generally Recognized As Safe (GRAS) in the United States. We tested whether Fibersol-2 contains anti-tumor activity. Human colorectal cancer cell line, HCT116, and its isogenic cells were treated with FIbersol-2. Tumor growth and tumorigenesis were studied in vitro and in vivo. Apoptotic pathway and generation of reactive oxygen species (ROS) were investigated. We discovered that Fibersol-2 significantly inhibits tumor growth of HCT116 cells by inducing apoptosis. Fibersol-2 strongly induces mitochondrial ROS and Bax-dependent cleavage of caspase 3 and 9, which is shown by isogenic HCT116 variants. Fibersol-2 induces phosphorylation of Akt, mTOR in parental HCT116 cells, but not in HCT116 deficient for Bax or p53. It prevents growth of tumor xenograft without any apparent signs of toxicity in vivo. These results identify Fibersol-2 as a mechanism-based dietary supplement agent that could prevent colorectal cancer development.

  11. Penfluridol suppresses pancreatic tumor growth by autophagy-mediated apoptosis

    PubMed Central

    Ranjan, Alok; Srivastava, Sanjay K.

    2016-01-01

    Pancreatic tumors exhibit enhanced autophagy as compared to any other cancer, making it resistant to chemotherapy. We evaluated the effect of penfluridol against pancreatic cancer. Penfluridol treatment induced apoptosis and inhibited the growth of Panc-1, BxPC-3 and AsPC-1, pancreatic cancer cells with IC50 ranging between 6–7 μM after 24 h of treatment. Significant autophagy was induced by penfluridol treatment in pancreatic cancer cells. Punctate LC3B and autophagosomes staining confirmed autophagy. Inhibiting autophagy by chloroquine, bafilomycin, 3-methyladenine or LC3BsiRNA, significantly blocked penfluridol-induced apoptosis, suggesting that autophagy lead to apoptosis in our model. Penfluridol treatment suppressed the growth of BxPC-3 tumor xenografts by 48% as compared to 17% when treated in combination with chloroquine. Similarly, penfluridol suppressed the growth of AsPC-1 tumors by 40% versus 16% when given in combination with chloroquine. TUNEL staining and caspase-3 cleavage revealed less apoptosis in the tumors from mice treated with penfluridol and chloroquine as compared to penfluridol alone. Penfluridol treatment also suppressed the growth of orthotopically implanted Panc-1 tumors by 80% by inducing autophagy-mediated apoptosis in the tumors. These studies established that penfluridol inhibits pancreatic tumor growth by autophagy-mediated apoptosis. Since penfluridol is already in clinic, positive findings from our study will accelerate its clinical development. PMID:27189859

  12. Targeting prion-like protein doppel selectively suppresses tumor angiogenesis

    PubMed Central

    Al-Hilal, Taslim A.; Chung, Seung Woo; Choi, Jeong Uk; Kim, Seong Who; Kim, Sang Yoon; Ahsan, Fakhrul; Kim, In-San

    2016-01-01

    Controlled and site-specific regulation of growth factor signaling remains a major challenge for current antiangiogenic therapies, as these antiangiogenic agents target normal vasculature as well tumor vasculature. In this article, we identified the prion-like protein doppel as a potential therapeutic target for tumor angiogenesis. We investigated the interactions between doppel and VEGFR2 and evaluated whether blocking the doppel/VEGFR2 axis suppresses the process of angiogenesis. We discovered that tumor endothelial cells (TECs), but not normal ECs, express doppel; tumors from patients and mouse xenografts expressed doppel in their vasculatures. Induced doppel overexpression in ECs enhanced vascularization, whereas doppel constitutively colocalized and complexed with VEGFR2 in TECs. Doppel inhibition depleted VEGFR2 from the cell membrane, subsequently inducing the internalization and degradation of VEGFR2 and thereby attenuating VEGFR2 signaling. We also synthesized an orally active glycosaminoglycan (LHbisD4) that specifically binds with doppel. We determined that LHbisD4 concentrates over the tumor site and that genetic loss of doppel in TECs decreases LHbisD4 binding and targeting both in vitro and in vivo. Moreover, LHbisD4 eliminated VEGFR2 from the cell membrane, prevented VEGF binding in TECs, and suppressed tumor growth. Together, our results demonstrate that blocking doppel can control VEGF signaling in TECs and selectively inhibit tumor angiogenesis. PMID:26950422

  13. Targeting prion-like protein doppel selectively suppresses tumor angiogenesis.

    PubMed

    Al-Hilal, Taslim A; Chung, Seung Woo; Choi, Jeong Uk; Alam, Farzana; Park, Jooho; Kim, Seong Who; Kim, Sang Yoon; Ahsan, Fakhrul; Kim, In-San; Byun, Youngro

    2016-04-01

    Controlled and site-specific regulation of growth factor signaling remains a major challenge for current antiangiogenic therapies, as these antiangiogenic agents target normal vasculature as well tumor vasculature. In this article, we identified the prion-like protein doppel as a potential therapeutic target for tumor angiogenesis. We investigated the interactions between doppel and VEGFR2 and evaluated whether blocking the doppel/VEGFR2 axis suppresses the process of angiogenesis. We discovered that tumor endothelial cells (TECs), but not normal ECs, express doppel; tumors from patients and mouse xenografts expressed doppel in their vasculatures. Induced doppel overexpression in ECs enhanced vascularization, whereas doppel constitutively colocalized and complexed with VEGFR2 in TECs. Doppel inhibition depleted VEGFR2 from the cell membrane, subsequently inducing the internalization and degradation of VEGFR2 and thereby attenuating VEGFR2 signaling. We also synthesized an orally active glycosaminoglycan (LHbisD4) that specifically binds with doppel. We determined that LHbisD4 concentrates over the tumor site and that genetic loss of doppel in TECs decreases LHbisD4 binding and targeting both in vitro and in vivo. Moreover, LHbisD4 eliminated VEGFR2 from the cell membrane, prevented VEGF binding in TECs, and suppressed tumor growth. Together, our results demonstrate that blocking doppel can control VEGF signaling in TECs and selectively inhibit tumor angiogenesis. PMID:26950422

  14. Smad4/DPC4-mediated tumor suppression through suppression of angiogenesis.

    PubMed

    Schwarte-Waldhoff, I; Volpert, O V; Bouck, N P; Sipos, B; Hahn, S A; Klein-Scory, S; Lüttges, J; Klöppel, G; Graeven, U; Eilert-Micus, C; Hintelmann, A; Schmiegel, W

    2000-08-15

    Smad4/DPC4 (deleted in pancreatic carcinoma, locus 4) is a tumor suppressor gene lost at high frequency in cancers of the pancreas and other gastrointestinal organs. Smad4 encodes a key intracellular messenger in the transforming growth factor beta (TGF-beta) signaling cascade. TGF-beta is a potent inhibitor of the growth of epithelial cells; thus, it has been assumed that loss of Smad4 during tumor progression relieves this inhibition. Herein, we show that restoration of Smad4 to human pancreatic carcinoma cells suppressed tumor formation in vivo, yet it did not restore sensitivity to TGF-beta. Rather, Smad4 restoration influenced angiogenesis, decreasing expression of vascular endothelial growth factor and increasing expression of thrombospondin-1. In contrast to the parental cell line and to control transfectants that produced rapidly growing tumors in vivo, Smad4 revertants induced small nonprogressive tumors with reduced vascular density. These data define the control of an angiogenic switch as an alternative, previously unknown mechanism of tumor suppression for Smad4 and identify the angiogenic mediators vascular endothelial growth factor and thrombospondin-1 as key target genes.

  15. High rates of chromosome missegregation suppress tumor progression but do not inhibit tumor initiation

    PubMed Central

    Zasadil, Lauren M.; Britigan, Eric M. C.; Ryan, Sean D.; Kaur, Charanjeet; Guckenberger, David J.; Beebe, David J.; Moser, Amy R.; Weaver, Beth A.

    2016-01-01

    Aneuploidy, an abnormal chromosome number that deviates from a multiple of the haploid, has been recognized as a common feature of cancers for >100 yr. Previously, we showed that the rate of chromosome missegregation/chromosomal instability (CIN) determines the effect of aneuploidy on tumors; whereas low rates of CIN are weakly tumor promoting, higher rates of CIN cause cell death and tumor suppression. However, whether high CIN inhibits tumor initiation or suppresses the growth and progression of already initiated tumors remained unclear. We tested this using the ApcMin/+ mouse intestinal tumor model, in which effects on tumor initiation versus progression can be discriminated. ApcMin/+ cells exhibit low CIN, and we generated high CIN by reducing expression of the kinesin-like mitotic motor protein CENP-E. CENP-E+/−;ApcMin/+ doubly heterozygous cells had higher rates of chromosome missegregation than singly heterozygous cells, resulting in increased cell death and a substantial reduction in tumor progression compared with ApcMin/+ animals. Intestinal organoid studies confirmed that high CIN does not inhibit tumor cell initiation but does inhibit subsequent cell growth. These findings support the conclusion that increasing the rate of chromosome missegregation could serve as a successful chemotherapeutic strategy. PMID:27146113

  16. AIP1 expression in tumor niche suppresses tumor progression and metastasis

    PubMed Central

    Ji, Weidong; Li, Yonghao; He, Yun; Yin, Mingzhu; Zhou, Huanjiao Jenny; Boggon, Titus J.; Zhang, Haifeng; Min, Wang

    2015-01-01

    Studies from tumor cells suggest that tumor suppressor AIP1 inhibits epithelial-mesenchymal transition (EMT). However, the role of AIP1 in the tumor microenvironment has not been examined. We show that a global or vascular endothelial cell (EC)-specific deletion of the AIP1 gene in mice augments tumor growth and metastasis in melanoma and breast cancer models. AIP1-deficient vascular environment not only enhances tumor neovascularization and increases pre-metastatic niche formation, but also secrets tumor EMT-promoting factors. These effects from AIP1 loss are associated with increased VEGFR2 signaling in the vascular EC and could be abrogated by systemic administration of VEGFR2 kinase inhibitors. Mechanistically, AIP1 blocks VEGFR2-dependent signaling by directly binding to the phosphotyrosine residues within the activation loop of VEGFR2. Our data reveal that AIP1, by inhibiting VEGFR2-dependent signaling in tumor niche, suppresses tumor EMT switch, tumor angiogenesis and tumor pre-metastatic niche formation to limit tumor growth and metastasis. PMID:26139244

  17. Inhibiting Delta-6 Desaturase Activity Suppresses Tumor Growth in Mice

    PubMed Central

    He, Chengwei; Qu, Xiying; Wan, Jianbo; Rong, Rong; Huang, Lili; Cai, Chun; Zhou, Keyuan; Gu, Yan; Qian, Steven Y.; Kang, Jing X.

    2012-01-01

    Recent studies have shown that a tumor-supportive microenvironment is characterized by high levels of pro-inflammatory and pro-angiogenic eicosanoids derived from omega-6 (n−6) arachidonic acid (AA). Although the metabolic pathways (COX, LOX, and P450) that generate these n−6 AA eicosanoids have been targeted, the role of endogenous AA production in tumorigenesis remains unexplored. Delta-6 desaturase (D6D) is the rate-limiting enzyme responsible for the synthesis of n−6 AA and increased D6D activity can lead to enhanced n−6 AA production. Here, we show that D6D activity is upregulated during melanoma and lung tumor growth and that suppressing D6D activity, either by RNAi knockdown or a specific D6D inhibitor, dramatically reduces tumor growth. Accordingly, the content of AA and AA-derived tumor-promoting metabolites is significantly decreased. Angiogenesis and inflammatory status are also reduced. These results identify D6D as a key factor for tumor growth and as a potential target for cancer therapy and prevention. PMID:23112819

  18. Biodegradable polymeric micelle-encapsulated doxorubicin suppresses tumor metastasis by killing circulating tumor cells

    NASA Astrophysics Data System (ADS)

    Deng, Senyi; Wu, Qinjie; Zhao, Yuwei; Zheng, Xin; Wu, Ni; Pang, Jing; Li, Xuejing; Bi, Cheng; Liu, Xinyu; Yang, Li; Liu, Lei; Su, Weijun; Wei, Yuquan; Gong, Changyang

    2015-03-01

    Circulating tumor cells (CTCs) play a crucial role in tumor metastasis, but it is rare for any chemotherapy regimen to focus on killing CTCs. Herein, we describe doxorubicin (Dox) micelles that showed anti-metastatic activity by killing CTCs. Dox micelles with a small particle size and high encapsulation efficiency were obtained using a pH-induced self-assembly method. Compared with free Dox, Dox micelles exhibited improved cytotoxicity, apoptosis induction, and cellular uptake. In addition, Dox micelles showed a sustained release behavior in vitro, and in a transgenic zebrafish model, Dox micelles exhibited a longer circulation time and lower extravasation from blood vessels into surrounding tissues. Anti-tumor and anti-metastatic activities of Dox micelles were investigated in transgenic zebrafish and mouse models. In transgenic zebrafish, Dox micelles inhibited tumor growth and prolonged the survival of tumor-bearing zebrafish. Furthermore, Dox micelles suppressed tumor metastasis by killing CTCs. In addition, improved anti-tumor and anti-metastatic activities were also confirmed in mouse tumor models, where immunofluorescent staining of tumors indicated that Dox micelles induced more apoptosis and showed fewer proliferation-positive cells. There were decreased side effects in transgenic zebrafish and mice after administration of Dox micelles. In conclusion, Dox micelles showed stronger anti-tumor and anti-metastatic activities and decreased side effects both in vitro and in vivo, which may have potential applications in cancer therapy.

  19. Tumor Growth Suppression Induced by Biomimetic Silk Fibroin Hydrogels

    PubMed Central

    Yan, Le-Ping; Silva-Correia, Joana; Ribeiro, Viviana P.; Miranda-Gonçalves, Vera; Correia, Cristina; da Silva Morais, Alain; Sousa, Rui A.; Reis, Rui M.; Oliveira, Ana L.; Oliveira, Joaquim M.; Reis, Rui L.

    2016-01-01

    Protein-based hydrogels with distinct conformations which enable encapsulation or differentiation of cells are of great interest in 3D cancer research models. Conformational changes may cause macroscopic shifts in the hydrogels, allowing for its use as biosensors and drug carriers. In depth knowledge on how 3D conformational changes in proteins may affect cell fate and tumor formation is required. Thus, this study reports an enzymatically crosslinked silk fibroin (SF) hydrogel system that can undergo intrinsic conformation changes from random coil to β-sheet conformation. In random coil status, the SF hydrogels are transparent, elastic, and present ionic strength and pH stimuli-responses. The random coil hydrogels become β-sheet conformation after 10 days in vitro incubation and 14 days in vivo subcutaneous implantation in rat. When encapsulated with ATDC-5 cells, the random coil SF hydrogel promotes cell survival up to 7 days, whereas the subsequent β-sheet transition induces cell apoptosis in vitro. HeLa cells are further incorporated in SF hydrogels and the constructs are investigated in vitro and in an in vivo chick chorioallantoic membrane model for tumor formation. In vivo, Angiogenesis and tumor formation are suppressed in SF hydrogels. Therefore, these hydrogels provide new insights for cancer research and uses of biomaterials. PMID:27485515

  20. The tumor microenvironment: a potential arbitrator of the tumor suppressive and promoting actions of TGFbeta.

    PubMed

    Dumont, Nancy; Arteaga, Carlos L

    2002-12-01

    Transforming growth factor beta (TGFbeta) members are secreted in biologically inactive complexes that must be activated in order to enable binding to their cell surface receptors. Interestingly, many of the proteins that can activate TGFbeta have been implicated in either suppressing or promoting tumorigenesis. Included among these are matrix proteins (thrombospondin-1), receptors (integrins alphanubeta6 and alphanubeta8) and proteases (matrix metalloproteases and plasmin). These proteins cannot only activate TGFbeta, but can also modulate cell responsiveness to TGFbeta. In this section, we review data highlighting the complexity and bidirectionality of TGFbeta matrix interactions within the tumor microenvironment, and propose that these dynamic interactions are a critical spatial and temporal determinant of the effects of TGFbeta on tumorigenesis.

  1. Oroxin B selectively induces tumor-suppressive ER stress and concurrently inhibits tumor-adaptive ER stress in B-lymphoma cells for effective anti-lymphoma therapy.

    PubMed

    Yang, Ping; Fu, Shilong; Cao, Zhifei; Liao, Huaidong; Huo, Zihe; Pan, Yanyan; Zhang, Gaochuan; Gao, Aidi; Zhou, Quansheng

    2015-10-15

    Cancer cells have both tumor-adaptive and -suppressive endoplasmic reticulum (ER) stress machineries that determine cell fate. In malignant tumors including lymphoma, constant activation of tumor-adaptive ER stress and concurrent reduction of tumor-suppressive ER stress favors cancer cell proliferation and tumor growth. Current ER stress-based anti-tumor drugs typically activate both tumor-adaptive and -suppressive ER stresses, resulting in low anti-cancer efficacy; hence, selective induction of tumor-suppressive ER stress and inhibition of tumor-adaptive ER stress are new strategies for novel anti-cancer drug discovery. Thus far, specific tumor-suppressive ER stress therapeutics have remained absent in clinical settings. In this study, we explored unique tumor-suppressive ER stress agents from the traditional Chinese medicinal herb Oroxylum indicum, and found that a small molecule oroxin B selectively induced tumor-suppressive ER stress in malignant lymphoma cells, but not in normal cells, effectively inhibited lymphoma growth in vivo, and significantly prolonged overall survival of lymphoma-xenografted mice without obvious toxicity. Mechanistic studies have revealed that the expression of key tumor-adaptive ER-stress gene GRP78 was notably suppressed by oroxin B via down-regulation of up-stream key signaling protein ATF6, while tumor-suppressive ER stress master gene DDIT3 was strikingly activated through activating the MKK3-p38 signaling pathway, correcting the imbalance between tumor-suppressive DDIT3 and tumor-adaptive GRP78 in lymphoma. Together, selective induction of unique tumor-suppressive ER stress and concurrent inhibition of tumor-adaptive ER stress in malignant lymphoma are new and feasible approaches for novel anti-lymphoma drug discovery and anti-lymphoma therapy.

  2. Comparison of tamoxifen with edible seaweed (Eucheuma cottonii L.) extract in suppressing breast tumor.

    PubMed

    Shamsabadi, Fatemeh T; Khoddami, Ali; Fard, Samaneh Ghasemi; Abdullah, Rasedee; Othman, Hemn Hassan; Mohamed, Suhaila

    2013-01-01

    The tropical edible red seaweed (Eucheuma cottonii L.) is rich in nutrients and polyphenolic compounds that may suppress cancer through its antioxidant and antiproliferative properties. The study reports on rat mammary tumor suppression and tissue antioxidant status modulation by E. cottonii ethanol extract (ECE). The effect of orally administered ECE (100 mg/kg body-weight) was compared with that of tamoxifen (10 mg/kg body-weight). Rat was induced to develop mammary tumor with subcutaneous injection of LA-7 cells (6 × 10(6) cells/rat). The ECE was more effective than tamoxifen in suppressing tumor growth (27%), improving tissues (plasma, liver, and kidney) malondialdehyde concentrations, superoxide dismutase activity and erythrocyte glutathione concentrations (P < 0.05). Unlike tamoxifen, the ECE displayed little toxicity to the liver and kidneys. The ECE exhibited strong anticancer effect with enzyme modulating properties, suggesting its potential as a suppressing agent for mammary gland tumor. PMID:23441613

  3. Regulatory T Cells in Tumor-Associated Tertiary Lymphoid Structures Suppress Anti-tumor T Cell Responses.

    PubMed

    Joshi, Nikhil S; Akama-Garren, Elliot H; Lu, Yisi; Lee, Da-Yae; Chang, Gregory P; Li, Amy; DuPage, Michel; Tammela, Tuomas; Kerper, Natanya R; Farago, Anna F; Robbins, Rebecca; Crowley, Denise M; Bronson, Roderick T; Jacks, Tyler

    2015-09-15

    Infiltration of regulatory T (Treg) cells into many tumor types correlates with poor patient prognoses. However, mechanisms of intratumoral Treg cell function remain to be elucidated. We investigated Treg cell function in a genetically engineered mouse model of lung adenocarcinoma and found that Treg cells suppressed anti-tumor responses in tumor-associated tertiary lymphoid structures (TA-TLSs). TA-TLSs have been described in human lung cancers, but their function remains to be determined. TLSs in this model were spatially associated with >90% of tumors and facilitated interactions between T cells and tumor-antigen-presenting dendritic cells (DCs). Costimulatory ligand expression by DCs and T cell proliferation rates increased in TA-TLSs upon Treg cell depletion, leading to tumor destruction. Thus, we propose that Treg cells in TA-TLSs can inhibit endogenous immune responses against tumors, and targeting these cells might provide therapeutic benefit for cancer patients.

  4. Regulatory T cells in tumor-associated tertiary lymphoid structures suppress anti-tumor T cell responses

    PubMed Central

    Joshi, Nikhil S.; Akama-Garren, Elliot H.; Lu, Yisi; Lee, Da-Yae; Chang, Gregory P.; Li, Amy; DuPage, Michel; Tammela, Tuomas; Kerper, Natanya R.; Farago, Anna F.; Robbins, Rebecca; Crowley, Denise M.; Bronson, Roderick T.; Jacks, Tyler

    2016-01-01

    SUMMARY Infiltration of regulatory T (Treg) cells into many tumor types correlates with poor patient prognoses. However, mechanisms of intratumoral Treg cell function remain to be elucidated. We investigated Treg cell function in a genetically-engineered mouse lung adenocarcinoma model and found Treg cells suppress anti-tumor responses in tumor-associated tertiary lymphoid structures (TA-TLS). TA-TLS have been described in human lung cancers, but their function remains to be determined. TLS in this model were spatially associated with >90% of tumors and facilitated interactions between T cells and tumor-antigen presenting dendritic cells (DCs). Costimulatory ligand expression by DCs and T cell proliferation rates increased in TA-TLS upon Treg cell depletion, leading to tumor destruction. Thus, we propose Treg cells in TA-TLS can inhibit endogenous immune responses against tumors, and targeting these cells may provide therapeutic benefit for cancer patients. PMID:26341400

  5. 1p36 tumor suppression--a matter of dosage?

    PubMed

    Henrich, Kai-Oliver; Schwab, Manfred; Westermann, Frank

    2012-12-01

    A broad range of human malignancies is associated with nonrandom 1p36 deletions, suggesting the existence of tumor suppressors encoded in this region. Evidence for tumor-specific inactivation of 1p36 genes in the classic "two-hit" manner is scarce; however, many tumor suppressors do not require complete inactivation but contribute to tumorigenesis by partial impairment. We discuss recent data derived from both human tumors and functional cancer models indicating that the 1p36 genes CHD5, CAMTA1, KIF1B, CASZ1, and miR-34a contribute to cancer development when reduced in dosage by genomic copy number loss or other mechanisms. We explore potential interactions among these candidates and propose a model where heterozygous 1p36 deletion impairs oncosuppressive pathways via simultaneous downregulation of several dosage-dependent tumor suppressor genes.

  6. C6-ceramide nanoliposome suppresses tumor metastasis by eliciting PI3K and PKCζ tumor-suppressive activities and regulating integrin affinity modulation

    PubMed Central

    Zhang, Pu; Fu, Changliang; Hu, Yijuan; Dong, Cheng; Song, Yang; Song, Erqun

    2015-01-01

    Nanoliposomal formulation of C6-ceramide, a proapoptotic sphingolipid metabolite, presents an effective way to treat malignant tumor. Here, we provide evidence that acute treatment (30 min) of melanoma and breast cancer cells with nanoliposomal C6-ceramide (NaL-C6) may suppress cell migration without inducing cell death. By employing a novel flow migration assay, we demonstrated that NaL-C6 decreased tumor extravasation under shear conditions. Compared with ghost nanoliposome, NaL-C6 triggered phosphorylation of PI3K and PKCζ and dephosphorylation of PKCα. Concomitantly, activated PKCζ translocated into cell membrane. siRNA knockdown or pharmacological inhibition of PKCζ or PI3K rescued NaL-C6-mediated suppression of tumor migration. By inducing dephosphorylation of paxillin, PKCζ was responsible for NaL-C6-mediated stress fiber depolymerization and focal adhesion disassembly in the metastatic tumor cells. PKCζ and PI3K regulated cell shear-resistant adhesion in a way that required integrin αvβ3 affinity modulation. In conclusion, we identified a novel role of acute nanoliposomal ceramide treatment in reducing integrin affinity and inhibiting melanoma metastasis by conferring PI3K and PKCζ tumor-suppressive activities. PMID:25792190

  7. NBR2: A former junk gene emerges as a key player in tumor suppression.

    PubMed

    Xiao, Zhen-Dong; Liu, Xiaowen; Zhuang, Li; Gan, Boyi

    2016-07-01

    NBR2 (neighbor of BRCA1 gene 2) is a non-protein coding gene that resides adjacent to tumor suppressor gene BRCA1, but its role in cancer biology has remained unknown. Our recent study showed that NBR2 encodes a long non-coding RNA and suppresses tumor development through regulation of adenosine monophosphate-activated protein kinase (AMPK) activation. PMID:27652330

  8. Differences in the effects of host suppression on the adoptive immunotherapy of subcutaneous and visceral tumors

    SciTech Connect

    Chang, A.E.; Shu, S.Y.; Chou, T.; Lafreniere, R.; Rosenberg, S.A.

    1986-07-01

    A syngeneic transplantable sarcoma induced in C57BL/6 mice, MCA 105, was used in studies to examine host suppression on the adoptive immunotherapy of established intradermal and experimentally induced pulmonary and hepatic metastases. Fresh immune splenocytes were generated from mice immunized to the MCA 105 tumor by a mixture of viable tumor cells and Corynebacterium parvum. The adoptive immunotherapy of intradermal MCA 105 tumor with immune cells required prior immunosuppression of the recipient by sublethal irradiation with 500 R or T-cell depletion. The effect of whole-body sublethal irradiation appeared to eliminate a systemic host suppression mechanism, since partialbody irradiation involving the tumor-bearing area did not permit successful immunotherapy. Host irradiation was not required to achieve successful immunotherapy of experimentally induced pulmonary or hepatic metastases. In nonirradiated recipients bearing both intradermal and pulmonary tumors, host suppression did not affect the function of transferred immune cells to induce regression of pulmonary metastases. Thus, suppression of adoptive immunotherapy appears to be relevant to tumors confined to the skin and subcutaneous tissue but not to tumor in visceral sites, such as the lung and liver.

  9. CDC42 inhibition suppresses progression of incipient intestinal tumors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mutations in the APC or Beta-catenin genes are well-established initiators of colorectal cancer, yet modifiers that facilitate the survival and progression of nascent tumor cells are not well defined. Using genetic and pharmacologic approaches in mouse colorectal cancer and human colorectal cancer x...

  10. T-cell-mediated suppression of anti-tumor immunity. An explanation for progressive growth of an immunogenic tumor

    PubMed Central

    1980-01-01

    The results of this paper are consistent with the hypothesis that progressive growth of the Meth A fibrosarcoma evokes the generation of a T-cell-mediated mechanism of immunosuppression that prevents this highly immunogenic tumor from being rejected by its immunocompetent host. It was shown that it is possible to cause the regression of large, established Meth A tumors by intravenous infusion of tumor- sensitized T cells from immune donors, but only if the tumors are growing in T-cell-deficient recipients. It was also shown that the adoptive T-cell-mediated regression of tumors in such recipients can be prevented by prior infusion of splenic T cells from T-cell-intact, tumor-bearing donors. The results leave little doubt that the presence of suppressor T cells in T-cell-intact, tumor-bearing mice is responsible for the loss of an earlier generated state of concomitant immunity, and for the inability of intravenously infused, sensitized T cells to cause tumor regression. Because the presence of suppressor T cells generated in response to the Meth A did not suppress the capacity of Meth A-bearing mice to generate and express immunity against a tumor allograft, it is obvious that they were not in a state of generalized immunosuppression. PMID:6444236

  11. Full p53 transcriptional activation potential is dispensable for tumor suppression in diverse lineages.

    PubMed

    Jiang, Dadi; Brady, Colleen A; Johnson, Thomas M; Lee, Eunice Y; Park, Eunice J; Scott, Matthew P; Attardi, Laura D

    2011-10-11

    Over half of all human cancers, of a wide variety of types, sustain mutations in the p53 tumor suppressor gene. Although p53 limits tumorigenesis through the induction of apoptosis or cell cycle arrest, its molecular mechanism of action in tumor suppression has been elusive. The best-characterized p53 activity in vitro is as a transcriptional activator, but the identification of numerous additional p53 biochemical activities in vitro has made it unclear which mechanism accounts for tumor suppression. Here, we assess the importance of transcriptional activation for p53 tumor suppression function in vivo in several tissues, using a knock-in mouse strain expressing a p53 mutant compromised for transcriptional activation, p53(25,26). p53(25,26) is severely impaired for the transactivation of numerous classical p53 target genes, including p21, Noxa, and Puma, but it retains the ability to activate a small subset of p53 target genes, including Bax. Surprisingly, p53(25,26) can nonetheless suppress tumor growth in cancers derived from the epithelial, mesenchymal, central nervous system, and lymphoid lineages. Therefore, full transactivation of most p53 target genes is dispensable for p53 tumor suppressor function in a range of tissue types. In contrast, a transcriptional activation mutant that is completely defective for transactivation, p53(25,26,53,54), fails to suppress tumor development. These findings demonstrate that transcriptional activation is indeed broadly critical for p53 tumor suppressor function, although this requirement reflects the limited transcriptional activity observed with p53(25,26) rather than robust transactivation of a full complement of p53 target genes.

  12. Salmonella typhimurium Suppresses Tumor Growth via the Pro-Inflammatory Cytokine Interleukin-1β

    PubMed Central

    Kim, Jung-Eun; Phan, Thuy Xuan; Nguyen, Vu Hong; Dinh-Vu, Hong-Van; Zheng, Jin Hai; Yun, Misun; Park, Sung-Gyoo; Hong, Yeongjin; Choy, Hyon E.; Szardenings, Michael; Hwang, Won; Park, Jin-A; Park, SunHee; Im, Sin-Hyeog; Min, Jung-Joon

    2015-01-01

    Although strains of attenuated Salmonella typhimurium and wild-type Escherichia coli show similar tumor-targeting capacities, only S. typhimurium significantly suppresses tumor growth in mice. The aim of the present study was to examine bacteria-mediated immune responses by conducting comparative analyses of the cytokine profiles and immune cell populations within tumor tissues colonized by E. coli or attenuated Salmonellae. CT26 tumor-bearing mice were treated with two different bacterial strains: S. typhimurium defective in ppGpp synthesis (ΔppGpp Salmonellae) or wild-type E. coli MG1655. Cytokine profiles and immune cell populations in tumor tissue colonized by these two bacterial strains were examined at two time points based on the pattern of tumor growth after ΔppGpp Salmonellae treatment: 1) when tumor growth was suppressed ('suppression stage') and 2) when they began to re-grow ('re-growing stage'). The levels of IL-1β and TNF-α were markedly increased in tumors colonized by ΔppGpp Salmonellae. This increase was associated with tumor regression; the levels of both IL-1β and TNF-α returned to normal level when the tumors started to re-grow. To identify the immune cells primarily responsible for Salmonellae-mediated tumor suppression, we examined the major cell types that produce IL-1β and TNF-α. We found that macrophages and dendritic cells were the main producers of TNF-α and IL-1β. Inhibiting IL-1β production in Salmonellae-treated mice restored tumor growth, whereas tumor growth was suppressed for longer by local administration of recombinant IL-1β or TNF-α in conjunction with Salmonella therapy. These findings suggested that IL-1β and TNF-α play important roles in Salmonella-mediated cancer therapy. A better understanding of host immune responses in Salmonella therapy may increase the success of a given drug, particularly when various strategies are combined with bacteriotherapy. PMID:26516371

  13. New insights into IL-12-mediated tumor suppression

    PubMed Central

    Tugues, S; Burkhard, S H; Ohs, I; Vrohlings, M; Nussbaum, K; vom Berg, J; Kulig, P; Becher, B

    2015-01-01

    During the past two decades, interleukin-12 (IL-12) has emerged as one of the most potent cytokines in mediating antitumor activity in a variety of preclinical models. Through pleiotropic effects on different immune cells that form the tumor microenvironment, IL-12 establishes a link between innate and adaptive immunity that involves different immune effector cells and cytokines depending on the type of tumor or the affected tissue. The robust antitumor response exerted by IL-12, however, has not yet been successfully translated into the clinics. The majority of clinical trials involving treatment with IL-12 failed to show sustained antitumor responses and were associated to toxic side effects. Here we discuss the therapeutic effects of IL-12 from preclinical to clinical studies, and will highlight promising strategies to take advantage of the antitumor activity of IL-12 while limiting adverse effects. PMID:25190142

  14. Systemic elevation of PTEN induces a tumor suppressive metabolic state

    PubMed Central

    Garcia-Cao, Isabel; Song, Min Sup; Hobbs, Robin M.; Laurent, Gaelle; Giorgi, Carlotta; de Boer, Vincent C.J.; Anastasiou, Dimitrios; Ito, Keisuke; Sasaki, Atsuo T.; Rameh, Lucia; Carracedo, Arkaitz; Vander Heiden, Matthew G.; Cantley, Lewis C.; Pinton, Paolo; Haigis, Marcia C.; Pandolfi, Pier Paolo

    2012-01-01

    SUMMARY Decremental loss of PTEN results in cancer susceptibility and tumor progression. In turn this raises the possibility that PTEN elevation might be an attractive option for cancer prevention and therapy. We have generated several transgenic mouse lines with variably elevated PTEN expression levels, taking advantage of BAC (Bacterial Artificial Chromosome)-mediated transgenesis. Super-PTEN mutants are viable and show reduced body size due to decreased cell number, with no effect on cell size. Unexpectedly, PTEN elevation at the organism level results in healthy metabolism characterized by increased energy expenditure and reduced body fat accumulation. Cells derived from these mice show reduced glucose and glutamine uptake, increased mitochondrial oxidative phosphorylation, and are resistant to oncogenic transformation. Mechanistically we find that PTEN elevation orchestrates this metabolic switch by regulating PI3K-dependent and independent pathways, and negatively impacts two of the most pronounced metabolic features of tumor cells: glutaminolysis and the Warburg effect. PMID:22401813

  15. USP10 antagonizes c-Myc transcriptional activation through SIRT6 stabilization to suppress tumor formation.

    PubMed

    Lin, Zhenghong; Yang, Heeyoung; Tan, Can; Li, Jinping; Liu, Zhaojian; Quan, Qiu; Kong, Sinyi; Ye, Junsheng; Gao, Beixue; Fang, Deyu

    2013-12-26

    The reduced protein expression of SIRT6 tumor suppressor is involved in tumorigenesis. The molecular mechanisms underlying SIRT6 protein downregulation in human cancers remain unknown. Using a proteomic approach, we have identified the ubiquitin-specific peptidase USP10, another tumor suppressor, as one of the SIRT6-interacting proteins. USP10 suppresses SIRT6 ubiquitination to protect SIRT6 from proteasomal degradation. USP10 antagonizes the transcriptional activity of the c-Myc oncogene through SIRT6, as well as p53, to inhibit cell-cycle progression, cancer cell growth, and tumor formation. To support this conclusion, we detected significant reductions in both USP10 and SIRT6 protein expression in human colon cancers. Our study discovered crosstalk between two tumor-suppressive genes in regulating cell-cycle progression and proliferation and showed that dysregulated USP10 function promotes tumorigenesis through SIRT6 degradation.

  16. ESCRT-0 is not required for ectopic Notch activation and tumor suppression in Drosophila.

    PubMed

    Tognon, Emiliana; Wollscheid, Nadine; Cortese, Katia; Tacchetti, Carlo; Vaccari, Thomas

    2014-01-01

    Multivesicular endosome (MVE) sorting depends on proteins of the Endosomal Sorting Complex Required for Transport (ESCRT) family. These are organized in four complexes (ESCRT-0, -I, -II, -III) that act in a sequential fashion to deliver ubiquitylated cargoes into the internal luminal vesicles (ILVs) of the MVE. Drosophila genes encoding ESCRT-I, -II, -III components function in sorting signaling receptors, including Notch and the JAK/STAT signaling receptor Domeless. Loss of ESCRT-I, -II, -III in Drosophila epithelia causes altered signaling and cell polarity, suggesting that ESCRTs genes are tumor suppressors. However, the nature of the tumor suppressive function of ESCRTs, and whether tumor suppression is linked to receptor sorting is unclear. Unexpectedly, a null mutant in Hrs, encoding one of the components of the ESCRT-0 complex, which acts upstream of ESCRT-I, -II, -III in MVE sorting is dispensable for tumor suppression. Here, we report that two Drosophila epithelia lacking activity of Stam, the other known components of the ESCRT-0 complex, or of both Hrs and Stam, accumulate the signaling receptors Notch and Dome in endosomes. However, mutant tissue surprisingly maintains normal apico-basal polarity and proliferation control and does not display ectopic Notch signaling activation, unlike cells that lack ESCRT-I, -II, -III activity. Overall, our in vivo data confirm previous evidence indicating that the ESCRT-0 complex plays no crucial role in regulation of tumor suppression, and suggest re-evaluation of the relationship of signaling modulation in endosomes and tumorigenesis. PMID:24718108

  17. Limited Role of Murine ATM in Oncogene-Induced Senescence and p53-Dependent Tumor Suppression

    PubMed Central

    Martinez-Pastor, Barbara; Ortega-Molina, Ana; Soria, Rebeca; Collado, Manuel; Fernandez-Capetillo, Oscar; Serrano, Manuel

    2009-01-01

    Recent studies in human fibroblasts have provided a new general paradigm of tumor suppression according to which oncogenic signaling produces DNA damage and this, in turn, results in ATM/p53-dependent cellular senescence. Here, we have tested this model in a variety of murine experimental systems. Overexpression of oncogenic Ras in murine fibroblasts efficiently induced senescence but this occurred in the absence of detectable DNA damage signaling, thus suggesting a fundamental difference between human and murine cells. Moreover, lung adenomas initiated by endogenous levels of oncogenic K-Ras presented abundant senescent cells, but undetectable DNA damage signaling. Accordingly, K-Ras-driven adenomas were also senescent in Atm-null mice, and the tumorigenic progression of these lesions was only modestly accelerated by Atm-deficiency. Finally, we have examined chemically-induced fibrosarcomas, which possess a persistently activated DNA damage response and are highly sensitive to the activity of p53. We found that the absence of Atm favored genomic instability in the resulting tumors, but did not affect the persistent DNA damage response and did not impair p53-dependent tumor suppression. All together, we conclude that oncogene-induced senescence in mice may occur in the absence of a detectable DNA damage response. Regarding murine Atm, our data suggest that it plays a minor role in oncogene-induced senescence or in p53-dependent tumor suppression, being its tumor suppressive activity probably limited to the maintenance of genomic stability. PMID:19421407

  18. Suppressive effects of tumor cell-derived 5'-deoxy-5'-methylthioadenosine on human T cells.

    PubMed

    Henrich, Frederik C; Singer, Katrin; Poller, Kerstin; Bernhardt, Luise; Strobl, Carolin D; Limm, Katharina; Ritter, Axel P; Gottfried, Eva; Völkl, Simon; Jacobs, Benedikt; Peter, Katrin; Mougiakakos, Dimitrios; Dettmer, Katja; Oefner, Peter J; Bosserhoff, Anja-Katrin; Kreutz, Marina P; Aigner, Michael; Mackensen, Andreas

    2016-08-01

    The immunosuppressive tumor microenvironment represents one of the main obstacles for immunotherapy of cancer. The tumor milieu is among others shaped by tumor metabolites such as 5'-deoxy-5'-methylthioadenosine (MTA). Increased intratumoral MTA levels result from a lack of the MTA-catabolizing enzyme methylthioadenosine phosphorylase (MTAP) in tumor cells and are found in various tumor entities. Here, we demonstrate that MTA suppresses proliferation, activation, differentiation, and effector function of antigen-specific T cells without eliciting cell death. Conversely, if MTA is added to highly activated T cells, MTA exerts cytotoxic effects on T cells. We identified the Akt pathway, a critical signal pathway for T cell activation, as a target of MTA, while, for example, p38 remained unaffected. Next, we provide evidence that MTA exerts its immunosuppressive effects by interfering with protein methylation in T cells. To confirm the relevance of the suppressive effects of exogenously added MTA on human T cells, we used an MTAP-deficient tumor cell-line that was stably transfected with the MTAP-coding sequence. We observed that T cells stimulated with MTAP-transfected tumor cells revealed a higher proliferative capacity compared to T cells stimulated with Mock-transfected cells. In conclusion, our findings reveal a novel immune evasion strategy of human tumor cells that could be of interest for therapeutic targeting. PMID:27622058

  19. Triparanol suppresses human tumor growth in vitro and in vivo

    SciTech Connect

    Bi, Xinyu; Han, Xingpeng; Zhang, Fang; He, Miao; Zhang, Yi; Zhi, Xiu-Yi; Zhao, Hong

    2012-08-31

    Highlights: Black-Right-Pointing-Pointer Demonstrate Triparanol can block proliferation in multiple cancer cells. Black-Right-Pointing-Pointer Demonstrate Triparanol can induce apoptosis in multiple cancer cells. Black-Right-Pointing-Pointer Proved Triparanol can inhibit Hedgehog signaling in multiple cancer cells. Black-Right-Pointing-Pointer Demonstrated Triparanol can impede tumor growth in vivo in mouse xenograft model. -- Abstract: Despite the improved contemporary multidisciplinary regimens treating cancer, majority of cancer patients still suffer from adverse effects and relapse, therefore posing a significant challenge to uncover more efficacious molecular therapeutics targeting signaling pathways central to tumorigenesis. Here, our study have demonstrated that Triparanol, a cholesterol synthesis inhibitor, can block proliferation and induce apoptosis in multiple human cancer cells including lung, breast, liver, pancreatic, prostate cancer and melanoma cells, and growth inhibition can be rescued by exogenous addition of cholesterol. Remarkably, we have proved Triparanol can significantly repress Hedgehog pathway signaling in these human cancer cells. Furthermore, study in a mouse xenograft model of human lung cancer has validated that Triparanol can impede tumor growth in vivo. We have therefore uncovered Triparanol as potential new cancer therapeutic in treating multiple types of human cancers with deregulated Hedgehog signaling.

  20. Genetic and epigenetic mutations of tumor suppressive genes in sporadic pituitary adenoma.

    PubMed

    Zhou, Yunli; Zhang, Xun; Klibanski, Anne

    2014-04-01

    Human pituitary adenomas are the most common intracranial neoplasms. Approximately 5% of them are familial adenomas. Patients with familial tumors carry germline mutations in predisposition genes, including AIP, MEN1 and PRKAR1A. These mutations are extremely rare in sporadic pituitary adenomas, which therefore are caused by different mechanisms. Multiple tumor suppressive genes linked to sporadic tumors have been identified. Their inactivation is caused by epigenetic mechanisms, mainly promoter hypermethylation, and can be placed into two groups based on their functional interaction with tumor suppressors RB or p53. The RB group includes CDKN2A, CDKN2B, CDKN2C, RB1, BMP4, CDH1, CDH13, GADD45B and GADD45G; AIP and MEN1 genes also belong to this group. The p53 group includes MEG3, MGMT, PLAGL1, RASSF1, RASSF3 and SOCS1. We propose that the tumor suppression function of these genes is mainly mediated by the RB and p53 pathways. We also discuss possible tumor suppression mechanisms for individual genes. PMID:24035864

  1. Genetic and epigenetic mutations of tumor suppressive genes in sporadic pituitary adenoma

    PubMed Central

    Zhou, Yunli; Zhang, Xun; Klibanski, Anne

    2013-01-01

    Human pituitary adenomas are the most common intracranial neoplasms. Approximately 5% of them are familial adenomas. Patients with familial tumors carry germline mutations in predisposition genes, including AIP, MEN1 and PRKAR1A. These mutations are extremely rare in sporadic pituitary adenomas, which therefore are caused by different mechanisms. Multiple tumor suppressive genes linked to sporadic tumors have been identified. Their inactivation is caused by epigenetic mechanisms, mainly promoter hypermethylation, and can be placed into two groups based on their functional interaction with tumor suppressors RB or p53. The RB group includes CDKN2A, CDKN2B, CDKN2C, RB1, BMP4, CDH1, CDH13, GADD45B and GADD45G; AIP and MEN1 genes also belong to this group. The p53 group includes MEG3, MGMT, PLAGL1, RASSF1, RASSF3 and SOCS1. We propose that the tumor suppression function of these genes is mainly mediated by the RB and p53 pathways. We also discuss possible tumor suppression mechanisms for individual genes. PMID:24035864

  2. Histone Methylase MLL1 plays critical roles in tumor growth and angiogenesis and its knockdown suppresses tumor growth in vivo

    PubMed Central

    Ansari, Khairul I.; Kasiri, Sahba; Mandal, Subhrangsu S.

    2012-01-01

    Mixed lineage leukemias (MLL) are human histone H3 lysine-4 specific methyl transferases that play critical roles in gene expression, epigenetics, and cancer. Herein, we demonstrated that antisense-mediated knockdown of MLL1 induced cell cycle arrest and apoptosis in cultured cells. Intriguingly, application of MLL1-antisense specifically knocked down MLL1 in vivo and suppressed the growth of xenografted cervical tumor implanted in nude mouse. MLL1-knockdown downregulated various growth and angiogenic factors such as HIF1α, VEGF and CD31 in tumor tissue affecting tumor growth. MLL1 is overexpressed along the line of vascular network and localized adjacent to endothelial cell layer expressing CD31, indicating potential roles of MLL1 in vasculogenesis. MLL1 is also overexpressed in the hypoxic regions along with HIF1α. Overall, our studies demonstrated that MLL1 is a key player in hypoxia signaling, vasculogenesis, and tumor growth, and its depletion suppresses tumor growth in vivo, indicating its potential in novel cancer therapy. PMID:22926525

  3. IGFBP-3 suppresses VEGF expression and tumor angiogenesis in head and neck squamous cell carcinoma

    PubMed Central

    Oh, Seung-Hyun; Kim, Woo-Young; Lee, Ok-Hee; Kang, Ju-Hee; Woo, Jong-Kyu; Kim, Jai-Hyun; Glisson, Bonnie; Lee, Ho-Young

    2012-01-01

    Angiogenesis, the process by which new blood vessels are recruited to existing ones, is essential for tumor development. Insulin-like growth factor (IGF) binding protein-3 (IGFBP-3), which modulates bioavailability of IGF, has been studied for its potential role in angiogenesis during tissue regeneration and cancer development. In this study, we assessed the role of IGFBP-3 in tumor angiogenesis in head and neck squamous cell carcinoma (HNSCC) and human umbilical endothelial cells (HUVECs) using adenoviral (Ad-BP3) and recombinant (rBP3) IGFBP-3. Utilizing an in vivo orthotopic tongue tumor model, we confirmed that both Ad-BP3 and rBP3 suppress the growth of UMSCC38 HNSCC cells in vivo. Ad-BP3 inhibited vascularization in tongue tumors and chorio-allantoic membrane, and suppressed angiogenesis-stimulating activities in UMSCC38 cells. In HUVECs, Ad-BP3 decreased migration, invasion, and tube formation. rBP3 also suppressed production of VEGF in HUVECs and UMSCC38 cells. IGFBP-3-GGG, a mutant IGFBP-3 with loss of IGF binding capacity, suppressed VEGF production. In addition, we found that IGFBP-3 suppressed VEGF expression, even in mouse embryonic fibroblasts from an IGF-1R-null mouse. Finally, we demonstrated that IGFBP-3-GGG inhibits tumor angiogenesis and growth to the same degree as wild-type IGFBP-3. Taken together, these results support the hypothesis that IGFBP-3 has antiangiogenic activity in HNSCC, at least in part due to IGF-independent suppression of VEGF production from vascular endothelial cells and cancer cells. PMID:22494072

  4. Sanguinarine suppresses prostate tumor growth and inhibits survivin expression.

    PubMed

    Sun, Meng; Lou, Wei; Chun, Jae Yeon; Cho, Daniel S; Nadiminty, Nagalakshmi; Evans, Christopher P; Chen, Jun; Yue, Jiao; Zhou, Qinghua; Gao, Allen C

    2010-03-01

    Prostate cancer is a frequently occurring disease and is the second leading cause of cancer-related deaths of men in the United States. Current treatments have proved inadequate in curing or controlling prostate cancer, and a search for agents for the management of this disease is urgently needed. Survivin plays an important role in both progression of castration-resistant prostate cancer and resistance to chemotherapy. Altered expression of survivin in prostate cancer cells is associated with cancer progression, drug/radiation resistance, poor prognosis, and short patient survival. In the present study, the authors performed a cell-based rapid screen of the Prestwick Chemical Library consisting of 1120 Food and Drug Administration-approved compounds with known safety and bioavailability in humans to identify potential inhibitors of survivin and anticancer agents for prostate cancer. Sanguinarine, a benzophenanthridine alkaloid derived primarily from the bloodroot plant, was identified as a novel inhibitor of survivin that selectively kills prostate cancer cells over "normal" prostate epithelial cells. The authors found that sanguinarine inhibits survivin protein expression through protein degradation via the ubiquitin-proteasome system. Sanguinarine induces apoptosis and inhibits growth of human prostate cancer cells and in vivo tumor formation. Administration of sanguinarine, beginning 3 days after ectopic implantation of DU145 human prostate cancer cells, reduces both tumor weight and volume. In addition, sanguinarine sensitized paclitaxel-mediated growth inhibition and apoptosis, offering a potential therapeutic strategy for overcoming taxol resistance. These results suggest that sanguinarine may be developed as an agent either alone or in combination with taxol for treatment of prostate cancer overexpressing survivin. PMID:21318089

  5. The Bromodomain BET Inhibitor JQ1 Suppresses Tumor Angiogenesis in Models of Childhood Sarcoma.

    PubMed

    Bid, Hemant K; Phelps, Doris A; Xaio, Linlin; Guttridge, Denis C; Lin, Jiayuh; London, Cheryl; Baker, Laurence H; Mo, Xiaokui; Houghton, Peter J

    2016-05-01

    The bromodomain and extra-terminal domain inhibitor JQ1 has marked antitumor activity against several hematologic malignancies as well as solid tumor models. Here, we investigated its activity in vitro and in vivo against models of childhood rhabdomyosarcoma and Ewing sarcoma. In vitro, JQ1 (but not the inactive enantiomer JQ1R) inhibited cell proliferation and increased G1 fraction of cells, although there was no correlation between cell line sensitivity and suppression of c-MYC or MYCN. In vivo, xenografts showed significant inhibition of growth during the period of treatment, and rapid regrowth after treatment was stopped, activity typical of antiangiogenic agents. Furthermore, xenografts derived from cell lines intrinsically resistant or sensitive to JQ1 in vitro had similar sensitivity in vivo as xenografts. Further investigation showed that JQ1 reduced tumor vascularization. This was secondary to both drug-induced downregulation of tumor-derived growth factors and direct effects of JQ1 on vascular elements. JQ1 suppressed VEGF-stimulated vascularization of Matrigel plugs in mice, and in vitro suppressed differentiation, proliferation, and invasion of human umbilical cord vascular endothelial cells (HUVEC). In HUVECs, JQ1 partially suppressed c-MYC levels, but dramatically reduced AP-1 levels and activity through suppression of the AP-1-associated protein FOSL1. Our data suggest that the antitumor activity of JQ1 in these sarcoma models is largely a consequence of its antiangiogenic activity. Mol Cancer Ther; 15(5); 1018-28. ©2016 AACR. PMID:26908627

  6. Aging, tumor suppression and cancer: High-wire act!

    SciTech Connect

    Campisi, Judith

    2004-08-15

    Evolutionary theory holds that aging is a consequence of the declining force of natural selection with age. We discuss here the evidence that among the causes of aging in complex multicellular organisms, such as mammals, is the antagonistically pleiotropic effects of the cellular responses that protect the organism from cancer. Cancer is relatively rare in young mammals, owing in large measure to the activity of tumor suppressor mechanisms. These mechanisms either protect the genome from damage and/or mutations, or they elicit cellular responses--apoptosis or senescence--that eliminate or prevent the proliferation of somatic cells at risk for neoplastic transformation.We focus here on the senescence response, reviewing its causes, regulation and effects. In addition, we describe recent data that support the idea that both senescence and apoptosis may indeed be the double-edged swords predicted by the evolutionary hypothesis of antagonistic pleiotropy--protecting organisms from cancer early in life, but promoting aging phenotypes, including late life cancer, in older organisms.

  7. Tumor Suppressive Function of p21-activated Kinase 6 in Hepatocellular Carcinoma.

    PubMed

    Liu, Weisi; Liu, Yidong; Liu, Haiou; Zhang, Weijuan; Fu, Qiang; Xu, Jiejie; Gu, Jianxin

    2015-11-20

    Our previous studies identified the oncogenic role of p21-activated kinase 1 (PAK1) in hepatocellular carcinoma (HCC) and renal cell carcinoma (RCC). Contrarily, PAK6 was found to predict a favorable prognosis in RCC patients. Nevertheless, the ambiguous tumor suppressive function of PAK6 in hepatocarcinogenesis remains obscure. Herein, decreased PAK6 expression was found to be associated with tumor node metastasis stage progression and unfavorable overall survival in HCC patients. Additionally, overexpression and silence of PAK6 experiments showed that PAK6 inhibited xenografted tumor growth in vivo, and restricted cell proliferation, colony formation, migration, and invasion and promoted cell apoptosis and anoikis in vitro. Moreover, overexpression of kinase dead and nuclear localization signal deletion mutants of PAK6 experiments indicated the tumor suppressive function of PAK6 was partially dependent on its kinase activity and nuclear translocation. Furthermore, gain or loss of function in polycomb repressive complex 2 (PRC2) components, including EZH2, SUZ12, and EED, elucidated epigenetic control of H3K27me3-arbitrated PAK6 down-regulation in hepatoma cells. More importantly, negative correlation between PAK6 and EZH2 expression was observed in hepatoma tissues from HCC patients. These data identified the tumor suppressive role and potential underlying mechanism of PAK6 in hepatocarcinogenesis.

  8. Genetic ablation of SOX18 function suppresses tumor lymphangiogenesis and metastasis of melanoma in mice.

    PubMed

    Duong, Tam; Proulx, Steven T; Luciani, Paola; Leroux, Jean-Christophe; Detmar, Michael; Koopman, Peter; Francois, Mathias

    2012-06-15

    The lymphatic vasculature provides a major route for tumor metastasis and inhibiting neolymphangiogenesis induced by tumors can reduce metastasis in animal models. Developmental biology studies have identified the transcription factor SOX18 as a critical switch for lymphangiogenesis in the mouse embryo. Here, we show that SOX18 is also critical for tumor-induced lymphangiogenesis, and we show that suppressing SOX18 function is sufficient to impede tumor metastasis. Immunofluorescence analysis of murine tumor xenografts showed that SOX18 is reexpressed during tumor-induced neolymphangiogenesis. Tumors generated by implantation of firefly luciferase-expressing B16-F10 melanoma cells exhibited a reduced rate of metastasis to the regional draining lymph node in Sox18-deficient mice, as assessed by live bioluminescence imaging. Lower metastatic rates correlated with reduced tumoral lymphatic vessel density and diameter and with impaired drainage of peritumoral injected liposomes specific for lymph vessels from the sentinel lymph nodes. Overall, our findings suggested that SOX18 induction is a key step in mediating tumor lymphangiogenesis and metastasis, and they identify SOX18 as a potential therapeutic target for metastatic blockade. PMID:22523034

  9. DDX3 Represses Stemness by Epigenetically Modulating Tumor-suppressive miRNAs in Hepatocellular Carcinoma

    PubMed Central

    Li, Hao-Kang; Mai, Ru-Tsun; Huang, Hsien-Da; Chou, Chih-Hung; Chang, Yi-An; Chang, Yao-Wen; You, Li-Ru; Chen, Chun-Ming; Lee, Yan-Hwa Wu

    2016-01-01

    Studies indicate that the presence of cancer stem cells (CSCs) is responsible for poor prognosis of hepatocellular carcinoma (HCC) patients. In this study, the functional role of DDX3 in regulation of hepatic CSCs was investigated. Our results demonstrated that reduced DDX3 expression was not only inversely associated with tumor grade, but also predicted poor prognosis of HCC patients. Knockdown of DDX3 in HCC cell line HepG2 induced stemness gene signature followed by occurrence of self-renewal, chemoreisistance, EMT, migration as well as CSC expansion, and most importantly, DDX3 knockdown promotes tumorigenesis. Moreover, we found positive correlations between DDX3 level and expressions of tumor-suppressive miR-200b, miR-200c, miR-122 and miR-145, but not miR-10b and miR-519a, implying their involvement in DDX3 knockdown-induced CSC phenotypes. In addition, DDX3 reduction promoted up-regulation of DNA methyltransferase 3A (DNMT3A), while neither DNMT3B nor DNMT1 expression was affected. Enriched DNMT3A binding along with hypermethylation on promoters of these tumor-suppressive miRNAs reflected their transcriptional repressions in DDX3-knockdown cells. Furthermore, individual restoration of these tumor-suppressive miRNAs represses DDX3 knockdown-induced CSC phenotypes. In conclusion, our study suggested that DDX3 prevents generation of CSCs through epigenetically regulating a subset of tumor-suppressive miRNAs expressions, which strengthens tumor suppressor role of DDX3 in HCC. PMID:27344963

  10. E-cadherin determines Caveolin-1 tumor suppression or metastasis enhancing function in melanoma cells.

    PubMed

    Lobos-González, Lorena; Aguilar, Lorena; Diaz, Jorge; Diaz, Natalia; Urra, Hery; Torres, Vicente A; Silva, Veronica; Fitzpatrick, Christopher; Lladser, Alvaro; Hoek, Keith S; Leyton, Lisette; Quest, Andrew F G

    2013-07-01

    The role of caveolin-1 (CAV1) in cancer is highly controversial. CAV1 suppresses genes that favor tumor development, yet also promotes focal adhesion turnover and migration of metastatic cells. How these contrasting observations relate to CAV1 function in vivo is unclear. Our previous studies implicate E-cadherin in CAV1-dependent tumor suppression. Here, we use murine melanoma B16F10 cells, with low levels of endogenous CAV1 and E-cadherin, to unravel how CAV1 affects tumor growth and metastasis and to assess how co-expression of E-cadherin modulates CAV1 function in vivo in C57BL/6 mice. We find that overexpression of CAV1 in B16F10 (cav-1) cells reduces subcutaneous tumor formation, but enhances metastasis relative to control cells. Furthermore, E-cadherin expression in B16F10 (E-cad) cells reduces subcutaneous tumor formation and lung metastasis when intravenously injected. Importantly, co-expression of CAV1 and E-cadherin in B16F10 (cav-1/E-cad) cells abolishes tumor formation, lung metastasis, increased Rac-1 activity, and cell migration observed with B16F10 (cav-1) cells. Finally, consistent with the notion that CAV1 participates in switching human melanomas to a more malignant phenotype, elevated levels of CAV1 expression correlated with enhanced migration and Rac-1 activation in these cells.

  11. E-cadherin determines Caveolin-1 tumor suppression or metastasis enhancing function in melanoma cells

    PubMed Central

    Lobos-González, L; Aguilar, L; Diaz, J; Diaz, N; Urra, H; Torres, V; Silva, V; Fitzpatrick, C; Lladser, A; Hoek, K.S.; Leyton, L; Quest, AFG

    2013-01-01

    SUMMARY The role of caveolin-1 (CAV1) in cancer is highly controversial. CAV1 suppresses genes that favor tumor development, yet also promotes focal adhesion turnover and migration of metastatic cells. How these contrasting observations relate to CAV1 function in vivo is unclear. Our previous studies implicate E-cadherin in CAV1-dependent tumor suppression. Here we use murine melanoma B16F10 cells, with low levels of endogenous CAV1 and E-cadherin, to unravel how CAV1 affects tumor growth and metastasis, and to assess how co-expression of E-cadherin modulates CAV1 function in vivo in C57BL/6 mice. We find that overexpression of CAV1 in B16F10(cav-1) cells reduces subcutaneous tumor formation, but enhances metastasis relative to control cells. Furthermore, E-cadherin expression in B16F10(E-cad) cells reduces subcutaneous tumor formation, and lung metastasis when intravenously injected. Importantly, co-expression of CAV1 and E-cadherin in B16F10(cav1/E-cad) cells abolishes tumor formation, lung metastasis, increased Rac-1 activity and cell migration observed with B16F10(cav-1) cells. Finally, consistent with the notion that CAV1 participates in switching human melanomas to a more malignant phenotype, elevated levels of CAV1 expression correlated with enhanced migration and Rac-1 activation in these cells. PMID:23470013

  12. E-cadherin determines Caveolin-1 tumor suppression or metastasis enhancing function in melanoma cells.

    PubMed

    Lobos-González, Lorena; Aguilar, Lorena; Diaz, Jorge; Diaz, Natalia; Urra, Hery; Torres, Vicente A; Silva, Veronica; Fitzpatrick, Christopher; Lladser, Alvaro; Hoek, Keith S; Leyton, Lisette; Quest, Andrew F G

    2013-07-01

    The role of caveolin-1 (CAV1) in cancer is highly controversial. CAV1 suppresses genes that favor tumor development, yet also promotes focal adhesion turnover and migration of metastatic cells. How these contrasting observations relate to CAV1 function in vivo is unclear. Our previous studies implicate E-cadherin in CAV1-dependent tumor suppression. Here, we use murine melanoma B16F10 cells, with low levels of endogenous CAV1 and E-cadherin, to unravel how CAV1 affects tumor growth and metastasis and to assess how co-expression of E-cadherin modulates CAV1 function in vivo in C57BL/6 mice. We find that overexpression of CAV1 in B16F10 (cav-1) cells reduces subcutaneous tumor formation, but enhances metastasis relative to control cells. Furthermore, E-cadherin expression in B16F10 (E-cad) cells reduces subcutaneous tumor formation and lung metastasis when intravenously injected. Importantly, co-expression of CAV1 and E-cadherin in B16F10 (cav-1/E-cad) cells abolishes tumor formation, lung metastasis, increased Rac-1 activity, and cell migration observed with B16F10 (cav-1) cells. Finally, consistent with the notion that CAV1 participates in switching human melanomas to a more malignant phenotype, elevated levels of CAV1 expression correlated with enhanced migration and Rac-1 activation in these cells. PMID:23470013

  13. MicroRNA-340 suppresses osteosarcoma tumor growth and metastasis by directly targeting ROCK1

    SciTech Connect

    Zhou, Xin; Wei, Min; Wang, Wei

    2013-08-09

    Highlights: •miR-340 is downregulated in OS cell lines and tissues. •miR-340 suppresses OS cell proliferation, migration and invasion. •miR-340 suppresses tumor growth and metastasis of OS cells in nude mice. •ROCK1 is a target gene of miR-340. •ROCK1 is involved in miR-340-induced suppression of OS cell proliferation, migration and invasion. -- Abstract: MicroRNAs (miRNAs) play key roles in cancer development and progression. In the present study, we investigated the role of miR-340 in the progression and metastasis of osteosarcoma (OS). Our results showed that miR-340 was frequently downregulated in OS tumors and cell lines. Overexpression of miR-340 in OS cell lines significantly inhibited cell proliferation, migration, and invasion in vitro, and tumor growth and metastasis in a xenograft mouse model. ROCK1 was identified as a target of miR-340, and ectopic expression of miR-340 downregulated ROCK1 by direct binding to its 3′ untranslated region. siRNA-mediated silencing of ROCK1 phenocopied the effects of miR-340 overexpression, whereas restoration of ROCK1 in miR-340-overexpressing OS cells reversed the suppressive effects of miR-340. Together, these findings indicate that miR-340 acts as a tumor suppressor and its downregulation in tumor tissues may contribute to the progression and metastasis of OS through a mechanism involving ROCK1, suggesting miR-340 as a potential new diagnostic and therapeutic target for the treatment of OS.

  14. The BRCA1-interacting protein, Abraxas, is required for genomic stability and tumor suppression

    PubMed Central

    Castillo, Andy; Paul, Atanu; Sun, Baohua; Huang, Ting Hsiang; Wang, Yucai; Yazinski, Stephanie A.; Tyler, Jessica; Li, Lei; You, M James; Zou, Lee; Yao, Jun; Wang, Bin

    2014-01-01

    Summary Germline mutations of BRCA1 confer hereditary susceptibility to breast and ovarian cancer. However, somatic mutation of BRCA1 is infrequent in sporadic breast cancers. The BRCA1 protein C-terminus BRCT domains interact with multiple proteins and are required for BRCA1's tumor suppressor function. In this study, we demonstrated that Abraxas, a BRCA1 BRCT domain-interacting protein, plays a role in tumor suppression. Abraxas exerts its function through binding to BRCA1 to regulate DNA repair and maintain genome stability. Both homozygous and heterozygous Abraxas knockout mice exhibited decreased survival and increased tumor incidence. The gene encoding Abraxas suffers from gene copy loss and somatic mutations in multiple human cancers including breast, ovarian, and endometrial cancers, suggesting that mutation and loss of function of Abraxas may contribute to tumor development in human patients. PMID:25066119

  15. Increased suppression of oncolytic adenovirus carrying mutant k5 on colorectal tumor

    SciTech Connect

    Fan Junkai; Xiao Tian; Gu Jinfa; Wei Na; He Lingfeng; Ding Miao; Liu Xinyuan

    2008-09-19

    Angiogenesis plays a key role in the development of a wide variety of malignant tumors. The approach of targeting antiangiogenesis has become an important field of cancer gene therapy. In this study, the antiangiogenesis protein K5 (the kringle 5 of human plasminogen) has been mutated by changing leucine71 to arginine to form mK5. Then the ZD55-mK5, which is an oncolytic adenovirus expressing mK5, was constructed. It showed stronger inhibition on proliferation of human umbilical vein endothelial cell. Moreover, in tube formation and embryonic chorioallantoic membrane assay, ZD55-mK5 exhibited more effective antiangiogenesis than ZD55-K5. In addition, ZD55-mK5 generated obvious suppression on the growth of colorectal tumor xenografts and prolonged the life span of nude mice. These results indicate that ZD55-mK5 is a potent agent for inhibiting the tumor angiogenesis and tumor growth.

  16. Activation of mesenchymal stem cells by macrophages promotes tumor progression through immune suppressive effects

    PubMed Central

    Jia, Xiao-hua; Feng, Guo-wei; Wang, Zhong-liang; Du, Yang; Shen, Chen; Hui, Hui; Peng, Dong; Li, Zong-jin; Kong, De-ling; Tian, Jie

    2016-01-01

    Cancer development and progression is linked to tumor-associated macrophages (TAMs). Distinct TAMs subsets perform either protective or pathogenic effects in cancer. A protective role in carcinogenesis has been described for M1 macrophages, which activate antitumor mechanisms. By comparison, TAMs isolated from solid and metastatic tumors have a suppressive M2-like phenotype, which could support multiple aspects of tumor progression. Currently, it has not been clearly understood how macrophages in tumor-associated stroma could be hijacked to support tumor growth. Mesenchymal stem cells (MSCs) actively interact with components of the innate immune system and display both anti-inflammatory and pro-inflammatory effects. Here, we tested whether MSCs could favor the tumor to escape from immunologic surveillance in the presence of M1 macrophages. We found that MSCs educated by M1 condition medium (cMSCs) possessed a greatly enhanced ability in promoting tumor growth in vivo. Examination of cytokines/chemokines showed that the cMSCs acquired a regulatory profile, which expressed high levels of iNOS and MCP1. Consistent with an elevated MCP1 expression in cMSCs, the tumor-promoting effect of the cMSCs depended on MCP1 mediated macrophage recruitment to tumor sites. Furthermore, IL-6 secreted by the cMSCs could polarize infiltrated TAMs into M2-like macrophages. Therefore, when macrophages changed into M1 pro-inflammation type in tumor microenvironment, the MSCs would act as poor sensors and switchers to accelerate tumor growth. PMID:26988913

  17. A nonlinear competitive model of the prostate tumor growth under intermittent androgen suppression.

    PubMed

    Yang, Jing; Zhao, Tong-Jun; Yuan, Chang-Qing; Xie, Jing-Hui; Hao, Fang-Fang

    2016-09-01

    Hormone suppression has been the primary modality of treatment for prostate cancer. However long-term androgen deprivation may induce androgen-independent (AI) recurrence. Intermittent androgen suppression (IAS) is a potential way to delay or avoid the AI relapse. Mathematical models of tumor growth and treatment are simple while they are capable of capturing the essence of complicated interactions. Game theory models have analyzed that tumor cells can enhance their fitness by adopting genetically determined survival strategies. In this paper, we consider the survival strategies as the competitive advantage of tumor cells and propose a new model to mimic the prostate tumor growth in IAS therapy. Then we investigate the competition effect in tumor development by numerical simulations. The results indicate that successfully IAS-controlled states can be achieved even though the net growth rate of AI cells is positive for any androgen level. There is crucial difference between the previous models and the new one in the phase diagram of successful and unsuccessful tumor control by IAS administration, which means that the suggestions from the models for medication can be different. Furthermore we introduce quadratic logistic terms to the competition model to simulate the tumor growth in the environment with a finite carrying capacity considering the nutrients or inhibitors. The simulations show that the tumor growth can reach an equilibrium state or an oscillatory state with the net growth rate of AI cells being androgen independent. Our results suggest that the competition and the restraint of a limited environment can enhance the possibility of relapse prevention. PMID:27259386

  18. A nonlinear competitive model of the prostate tumor growth under intermittent androgen suppression.

    PubMed

    Yang, Jing; Zhao, Tong-Jun; Yuan, Chang-Qing; Xie, Jing-Hui; Hao, Fang-Fang

    2016-09-01

    Hormone suppression has been the primary modality of treatment for prostate cancer. However long-term androgen deprivation may induce androgen-independent (AI) recurrence. Intermittent androgen suppression (IAS) is a potential way to delay or avoid the AI relapse. Mathematical models of tumor growth and treatment are simple while they are capable of capturing the essence of complicated interactions. Game theory models have analyzed that tumor cells can enhance their fitness by adopting genetically determined survival strategies. In this paper, we consider the survival strategies as the competitive advantage of tumor cells and propose a new model to mimic the prostate tumor growth in IAS therapy. Then we investigate the competition effect in tumor development by numerical simulations. The results indicate that successfully IAS-controlled states can be achieved even though the net growth rate of AI cells is positive for any androgen level. There is crucial difference between the previous models and the new one in the phase diagram of successful and unsuccessful tumor control by IAS administration, which means that the suggestions from the models for medication can be different. Furthermore we introduce quadratic logistic terms to the competition model to simulate the tumor growth in the environment with a finite carrying capacity considering the nutrients or inhibitors. The simulations show that the tumor growth can reach an equilibrium state or an oscillatory state with the net growth rate of AI cells being androgen independent. Our results suggest that the competition and the restraint of a limited environment can enhance the possibility of relapse prevention.

  19. Sunlight suppressing rejection of 280- to 320-nm UV-radiation-induced skin tumors in mice

    SciTech Connect

    Morison, W.L.; Kelley, S.P.

    1985-02-01

    Repeated exposure of female C3H/HeNCR- mice to sunlight prevented the normal immunologic rejection of a UV-induced tumor. This systemic immunologic alteration was transferred to syngeneic lethally X-irradiated animals with lymphoid cells from mice exposed to sunlight. The lymphoid cells also were able to suppress the capacity of lymphoid cells from normal animals to reject a UV-induced tumor. The 295- to 320-nm wave band appeared to be responsible for this immunosuppressive effect of sunlight because suppression was prevented by filtration of the radiation through Mylar and by application of a sunscreen containing para-aminobenzoic acid. These observations may have importance in understanding the pathogenesis of sunlight-induced skin cancer in humans.

  20. OK-432 Suppresses Proliferation and Metastasis by Tumor Associated Macrophages in Bladder Cancer.

    PubMed

    Tian, Yuan-Feng; Tang, Kun; Guan, Wei; Yang, Tao; Xu, Hua; Zhuang, Qian-Yuan; Ye, Zhang-Qun

    2015-01-01

    OK-432, a Streptococcus-derived anticancer immunotherapeutic agent, has been applied in clinic for many years and achieved great progress in various cancers. In the present study, we investigated its anticancer effect on bladder cancer through tumor associated macrophages (TAMs). MTS assay validated OK-432 could inhibit proliferation in both T24 and EJ bladder cell lines. OK-432 also induced apoptosis of bladder cancer cells in vitro. Consequently, we demonstrated that OK-432 could suppress the bladder cancer cells migration and invasion by altering the EMT-related factors. Furthermore, using SD rat model, we revealed that OK-432 inhibited tumor growth, suppressed PCNA expression and inhibited metastasis in vivo. Taken together, these findings strongly suggest that OK-432 inhibits cell proliferation and metastasis through inducing macrophages to secret cytokines in bladder cancer.

  1. OK-432 Suppresses Proliferation and Metastasis by Tumor Associated Macrophages in Bladder Cancer.

    PubMed

    Tian, Yuan-Feng; Tang, Kun; Guan, Wei; Yang, Tao; Xu, Hua; Zhuang, Qian-Yuan; Ye, Zhang-Qun

    2015-01-01

    OK-432, a Streptococcus-derived anticancer immunotherapeutic agent, has been applied in clinic for many years and achieved great progress in various cancers. In the present study, we investigated its anticancer effect on bladder cancer through tumor associated macrophages (TAMs). MTS assay validated OK-432 could inhibit proliferation in both T24 and EJ bladder cell lines. OK-432 also induced apoptosis of bladder cancer cells in vitro. Consequently, we demonstrated that OK-432 could suppress the bladder cancer cells migration and invasion by altering the EMT-related factors. Furthermore, using SD rat model, we revealed that OK-432 inhibited tumor growth, suppressed PCNA expression and inhibited metastasis in vivo. Taken together, these findings strongly suggest that OK-432 inhibits cell proliferation and metastasis through inducing macrophages to secret cytokines in bladder cancer. PMID:26107200

  2. Disrupting Hypoxia-Induced Bicarbonate Transport Acidifies Tumor Cells and Suppresses Tumor Growth.

    PubMed

    McIntyre, Alan; Hulikova, Alzbeta; Ledaki, Ioanna; Snell, Cameron; Singleton, Dean; Steers, Graham; Seden, Peter; Jones, Dylan; Bridges, Esther; Wigfield, Simon; Li, Ji-Liang; Russell, Angela; Swietach, Pawel; Harris, Adrian L

    2016-07-01

    Tumor hypoxia is associated clinically with therapeutic resistance and poor patient outcomes. One feature of tumor hypoxia is activated expression of carbonic anhydrase IX (CA9), a regulator of pH and tumor growth. In this study, we investigated the hypothesis that impeding the reuptake of bicarbonate produced extracellularly by CA9 could exacerbate the intracellular acidity produced by hypoxic conditions, perhaps compromising cell growth and viability as a result. In 8 of 10 cancer cell lines, we found that hypoxia induced the expression of at least one bicarbonate transporter. The most robust and frequent inductions were of the sodium-driven bicarbonate transporters SLC4A4 and SLC4A9, which rely upon both HIF1α and HIF2α activity for their expression. In cancer cell spheroids, SLC4A4 or SLC4A9 disruption by either genetic or pharmaceutical approaches acidified intracellular pH and reduced cell growth. Furthermore, treatment of spheroids with S0859, a small-molecule inhibitor of sodium-driven bicarbonate transporters, increased apoptosis in the cell lines tested. Finally, RNAi-mediated attenuation of SLC4A9 increased apoptosis in MDA-MB-231 breast cancer spheroids and dramatically reduced growth of MDA-MB-231 breast tumors or U87 gliomas in murine xenografts. Our findings suggest that disrupting pH homeostasis by blocking bicarbonate import might broadly relieve the common resistance of hypoxic tumors to anticancer therapy. Cancer Res; 76(13); 3744-55. ©2016 AACR. PMID:27197160

  3. Inhibition of BRD4 suppresses tumor growth and enhances iodine uptake in thyroid cancer.

    PubMed

    Gao, Xuemei; Wu, Xinchao; Zhang, Xiao; Hua, Wenjuan; Zhang, Yajing; Maimaiti, Yusufu; Gao, Zairong; Zhang, Yongxue

    2016-01-15

    Thyroid cancer is a common malignancy of the endocrine system. Although radioiodine (131)I treatment on differentiated thyroid cancer is widely used, many patients still fail to benefit from (131)I therapy. Therefore, exploration of novel targeted therapies to suppress tumor growth and improve radioiodine uptake remains necessary. Bromodomain-containing protein 4 (BRD4) is an important member of the bromodomain and extra terminal domain family that influences transcription of downstream genes by binding to acetylated histones. In the present study, we found that BRD4 was up-regulated in thyroid cancer tissues and cell lines. Inhibition of BRD4 in thyroid cancer cells by JQ1 resulted in cell cycle arrest at G0/G1 phase and enhanced (131)I uptake in vitro and suppressed tumor growth in vivo. Moreover, JQ1 treatment suppressed C-MYC but enhanced NIS expression. We further demonstrated that BRD4 was enriched in the promoter region of C-MYC, which could be markedly blocked by JQ1 treatment. In conclusion, our findings revealed that the aberrant expression of BRD4 in thyroid cancer is possibly involved in tumor progression, and JQ1 is potentially an effective chemotherapeutic agent against human thyroid cancer. PMID:26707881

  4. Indoleamine-2,3-dioxygenase elevated in tumor-initiating cells is suppressed by mitocans.

    PubMed

    Stapelberg, Michael; Zobalova, Renata; Nguyen, Maria Nga; Walker, Tom; Stantic, Marina; Goodwin, Jacob; Pasdar, Elham Alizadeh; Thai, Thuan; Prokopova, Katerina; Yan, Bing; Hall, Susan; de Pennington, Nicholas; Thomas, Shane R; Grant, Gary; Stursa, Jan; Bajzikova, Martina; Meedeniya, Adrian C B; Truksa, Jaroslav; Ralph, Stephen J; Ansorge, Olaf; Dong, Lan-Feng; Neuzil, Jiri

    2014-02-01

    Tumor-initiating cells (TICs) often survive therapy and give rise to second-line tumors. We tested the plausibility of sphere cultures as models of TICs. Microarray data and microRNA data analysis confirmed the validity of spheres as models of TICs for breast and prostate cancer as well as mesothelioma cell lines. Microarray data analysis revealed the Trp pathway as the only pathway upregulated significantly in all types of studied TICs, with increased levels of indoleamine-2,3-dioxygenase-1 (IDO1), the rate-limiting enzyme of Trp metabolism along the kynurenine pathway. All types of TICs also expressed higher levels of the Trp uptake system consisting of CD98 and LAT1 with functional consequences. IDO1 expression was regulated via both transcriptional and posttranscriptional mechanisms, depending on the cancer type. Serial transplantation of TICs in mice resulted in gradually increased IDO1. Mitocans, represented by α-tocopheryl succinate and mitochondrially targeted vitamin E succinate (MitoVES), suppressed IDO1 in TICs. MitoVES suppressed IDO1 in TICs with functional mitochondrial complex II, involving transcriptional and posttranscriptional mechanisms. IDO1 increase and its suppression by VE analogues were replicated in TICs from primary human glioblastomas. Our work indicates that IDO1 is increased in TICs and that mitocans suppress the protein. PMID:24145120

  5. BET Bromodomain Inhibition Promotes Anti-tumor Immunity by Suppressing PD-L1 Expression.

    PubMed

    Zhu, Hengrui; Bengsch, Fee; Svoronos, Nikolaos; Rutkowski, Melanie R; Bitler, Benjamin G; Allegrezza, Michael J; Yokoyama, Yuhki; Kossenkov, Andrew V; Bradner, James E; Conejo-Garcia, Jose R; Zhang, Rugang

    2016-09-13

    Restoration of anti-tumor immunity by blocking PD-L1 signaling through the use of antibodies has proven to be beneficial in cancer therapy. Here, we show that BET bromodomain inhibition suppresses PD-L1 expression and limits tumor progression in ovarian cancer. CD274 (encoding PD-L1) is a direct target of BRD4-mediated gene transcription. In mouse models, treatment with the BET inhibitor JQ1 significantly reduced PD-L1 expression on tumor cells and tumor-associated dendritic cells and macrophages, which correlated with an increase in the activity of anti-tumor cytotoxic T cells. The BET inhibitor limited tumor progression in a cytotoxic T-cell-dependent manner. Together, these data demonstrate a small-molecule approach to block PD-L1 signaling. Given the fact that BET inhibitors have been proven to be safe with manageable reversible toxicity in clinical trials, our findings indicate that pharmacological BET inhibitors represent a treatment strategy for targeting PD-L1 expression. PMID:27626654

  6. Tumor suppressive activity of prolyl isomerase Pin1 in renal cell carcinoma

    PubMed Central

    Teng, Brian L.; Hacker, Kathryn E.; Chen, Shufen; Means, Anthony R.; Rathmell, W. Kimryn

    2011-01-01

    Pin1 specifically recognizes and catalyzes the cis-trans isomerization of phosphorylated-Ser/Thr-Pro bonds, which modulate the stability, localization, and function of numerous Pin1 targets involved in tumor progression. However, the role of Pin1 in cancer remains enigmatic as the gene is located on chromosome 19p13.2, which is a region subject to loss of heterozygosity in several tumors. Since Pin1 protein is frequently under-expressed in kidney cancer, we have explored its role in human clear cell renal cell carcinoma (ccRCC). Here we show evidence for PIN1 gene deletion and mRNA under-expression as a mechanism of Pin1 reduction in ccRCC tumors. We demonstrate that restoration of Pin1 in cell lines found to be deficient in Pin1 protein expression can attenuate the growth of ccRCC cells in soft agar and a xenograft tumor model. Moreover, this ability of Pin1 to negatively influence tumor growth in ccRCC cells may be dependent on the presence of functional p53, which is infrequently mutated in ccRCC. These observations suggest Pin1 may have a mild tumor suppressive role in ccRCC. PMID:21764651

  7. Tumor suppressive activity of prolyl isomerase Pin1 in renal cell carcinoma.

    PubMed

    Teng, Brian L; Hacker, Kathryn E; Chen, Shufen; Means, Anthony R; Rathmell, W Kimryn

    2011-10-01

    Pin1 specifically recognizes and catalyzes the cis-trans isomerization of phosphorylated-Ser/Thr-Pro bonds, which modulate the stability, localization, and function of numerous Pin1 targets involved in tumor progression. However, the role of Pin1 in cancer remains enigmatic as the gene is located on chromosome 19p13.2, which is a region subject to loss of heterozygosity in several tumors. Since Pin1 protein is frequently under-expressed in kidney cancer, we have explored its role in human clear cell renal cell carcinoma (ccRCC). Here we show evidence for PIN1 gene deletion and mRNA under-expression as a mechanism of Pin1 reduction in ccRCC tumors. We demonstrate that restoration of Pin1 in cell lines found to be deficient in Pin1 protein expression can attenuate the growth of ccRCC cells in soft agar and a xenograft tumor model. Moreover, this ability of Pin1 to negatively influence tumor growth in ccRCC cells may be dependent on the presence of functional p53, which is infrequently mutated in ccRCC. These observations suggest Pin1 may have a mild tumor suppressive role in ccRCC.

  8. Tumor suppression by miR-26 overrides potential oncogenic activity in intestinal tumorigenesis

    PubMed Central

    Zeitels, Lauren R.; Acharya, Asha; Shi, Guanglu; Chivukula, Divya; Chivukula, Raghu R.; Anandam, Joselin L.; Abdelnaby, Abier A.; Balch, Glen C.; Mansour, John C.; Yopp, Adam C.; Richardson, James A.

    2014-01-01

    Down-regulation of miR-26 family members has been implicated in the pathogenesis of multiple malignancies. In some settings, including glioma, however, miR-26-mediated repression of PTEN promotes tumorigenesis. To investigate the contexts in which the tumor suppressor versus oncogenic activity of miR-26 predominates in vivo, we generated miR-26a transgenic mice. Despite measureable repression of Pten, elevated miR-26a levels were not associated with malignancy in transgenic animals. We documented reduced miR-26 expression in human colorectal cancer and, accordingly, showed that miR-26a expression potently suppressed intestinal adenoma formation in Apcmin/+ mice, a model known to be sensitive to Pten dosage. These studies reveal a tumor suppressor role for miR-26 in intestinal cancer that overrides putative oncogenic activity, highlighting the therapeutic potential of miR-26 delivery to this tumor type. PMID:25395662

  9. The copper-chelating agent, trientine, suppresses tumor development and angiogenesis in the murine hepatocellular carcinoma cells.

    PubMed

    Yoshii, J; Yoshiji, H; Kuriyama, S; Ikenaka, Y; Noguchi, R; Okuda, H; Tsujinoue, H; Nakatani, T; Kishida, H; Nakae, D; Gomez, D E; De Lorenzo, M S; Tejera, A M; Fukui, H

    2001-12-15

    Angiogenesis is now recognized as a crucial process in tumor development, including hepatocellular carcinoma (HCC). Since HCC is known as a hypervascular tumor, anti-angiogenesis is a promising approach to inhibit the HCC development. Trientine dihydrochloride (trientine) is used in clinical practice as an alternative copper (Cu)-chelating agent for patients with Wilson's disease of penicillamine intolerance. In our study, we examined the effect of Cu-chelating agents on tumor development and angiogenesis in the murine HCC xenograft model. Although both trientine and penicillamine in the drinking water suppressed the tumor development, trientine exerted a more potent inhibitory effect than penicillamine. In combination with a Cu-deficient diet, both trientine and penicillamine almost abolished the HCC development. Trientine treatment resulted in a marked suppression of neovascularization and increase of apoptosis in the tumor, whereas tumor cell proliferation itself was not altered. In vitro studies also exhibited that trientine is not cytotoxic for the tumor cells. On the other hand, it significantly suppressed the endothelial cell proliferation. These results suggested that Cu plays a pivotal role in tumor development and angiogenesis in the murine HCC cells, and Cu-chelators, especially trientine, could inhibit angiogenesis and enhance apoptosis in the tumor with consequent suppression of the tumor growth in vivo. Since trientine is already used in clinical practice without any serious side effects as compared to penicillamine, it may be an effective new strategy for future HCC therapy.

  10. Huaier extract suppresses breast cancer via regulating tumor-associated macrophages

    PubMed Central

    Li, Yaming; Qi, Wenwen; Song, Xiaojin; Lv, Shangge; Zhang, Hanwen; Yang, Qifeng

    2016-01-01

    Macrophages in tumor microenvironment are mostly M2-polarized - and have been reported to promote tumorigenesis, which are also defined as tumor-associated macrophages (TAMs). Here, we examined the regulatory effects of Huaier extract on TAMs using RAW264.7 murine macrophage cell line. Our data demonstrated that Huaier extract could inhibit the infiltration of macrophages into tumor microenvironment in a dose-dependent manner. By performing RT-PCR, immunofluorescence and phagocytosis assay, we were able to find that Huaier extract could regulate the polarization of macrophages, with decreased M2-polarization and increased phagocytosis of RAW264.7 cells. Moreover, we identified that Huaier extract could suppress macrophages-induced angiogenesis by using HUVEC migration assay, tube formation and chorioallantoic membrane assay. Additionally, western blotting showed decreased expression of MMP2, MMP9 and VEGF with the use of Huaier extract. Finally, we found that Huaier extract could inhibit M2-macrophages infiltration and angiogenesis through treating 4T1 tumor bearing mice with Huaier extract. Our study revealed a novel mechanism of the anti-tumor effect of Huaier extract which inhibited angiogenesis by targeting TAMs. These findings provided that Huaier was a promising drug for clinical treatment of breast cancer. PMID:26831282

  11. DNA/polyethyleneimine/hyaluronic acid small complex particles and tumor suppression in mice.

    PubMed

    Ito, Tomoko; Yoshihara, Chieko; Hamada, Katsuyuki; Koyama, Yoshiyuki

    2010-04-01

    The highest barriers for non-viral vectors to an efficient in vivo gene transfection would be (1) non-specific interaction with biological molecules, and (2) large size of the DNA complex particles. Protective coating of the DNA/polyethyleneimine (PEI) complexes by hyaluronic acid (HA) effectively diminished the adverse interactions with biological molecules. Here we found HA also protected the DNA/PEI complexes against aggregation and inactivation through lyophilization-and-rehydration procedures. It allows us to prepare the concentrated very small DNA complex particles (<70 nm) suspension by preparing the complexes at highly diluted conditions, followed by lyophilized-and-rehydrated to a small volume. In vivo gene expression efficiency of the small complex was examined with mice subcutaneously inoculated with B16 melanoma cells. These formulations showed high reporter-gene expression level in tumor after intravenous injection into tumor-bearing mice. Small complex was then made of the plasmid encoding GM-CSF gene, and injected into the mice bearing subcutaneous solid B16 tumor. After intravenous injection, it induced apparent tumor growth suppression in 50% of the mice. Notably, significant therapeutic effect was detected in the mice that received intratumoral injection, and 75% of the mice were completely cured with disappearance of tumor. PMID:20047759

  12. The Dual Role of TGFβ in Human Cancer: From Tumor Suppression to Cancer Metastasis

    PubMed Central

    Lebrun, Jean-Jacques

    2012-01-01

    The transforming growth factor-beta (TGFβ) superfamily encompasses widespread and evolutionarily conserved polypeptide growth factors that regulate and orchestrate growth and differentiation in all cell types and tissues. While they regulate asymmetric cell division and cell fate determination during early development and embryogenesis, TGFβ family members play a major regulatory role in hormonal and immune responses, cell growth, cell death and cell immortalization, bone formation, tissue remodeling and repair, and erythropoiesis throughout adult life. The biological and physiological functions of TGFβ, the founding member of this family, and its receptors are of central importance to human diseases, particularly cancer. By regulating cell growth, death, and immortalization, TGFβ signaling pathways exert tumor suppressor effects in normal cells and early carcinomas. Thus, it is not surprising that a high number of human tumors arise due to mutations or deletions in the genes coding for the various TGFβ signaling components. As tumors develop and progress, these protective and cytostatic effects of TGFβ are often lost. TGFβ signaling then switches to promote cancer progression, invasion, and tumor metastasis. The molecular mechanisms underlying this dual role of TGFβ in human cancer will be discussed in depth in this paper, and it will highlight the challenge and importance of developing novel therapeutic strategies specifically aimed at blocking the prometastatic arm of the TGFβ signaling pathway without affecting its tumor suppressive effects. PMID:27340590

  13. AMPK is a negative regulator of the Warburg Effect and suppresses tumor growth in vivo

    PubMed Central

    Faubert, Brandon; Boily, Gino; Izreig, Said; Griss, Takla; Samborska, Bozena; Dong, Zhifeng; Dupuy, Fanny; Chambers, Christopher; Fuerth, Benjamin J.; Viollet, Benoit; Mamer, Orval A.; Avizonis, Daina; DeBerardinis, Ralph J.; Siegel, Peter M.; Jones, Russell G.

    2012-01-01

    Summary AMPK is a metabolic sensor that helps maintain cellular energy homeostasis. Despite evidence linking AMPK with tumor suppressor functions, the role of AMPK in tumorigenesis and tumor metabolism is unknown. Here we show that AMPK negatively regulates aerobic glycolysis (the Warburg effect) in cancer cells, and suppresses tumor growth in vivo. Genetic ablation of the α1 catalytic subunit of AMPK accelerates Myc-induced lymphomagenesis. Inactivation of AMPKα in both transformed and non-transformed cells promotes a metabolic shift to aerobic glycolysis, increased allocation of glucose carbon into lipids, and biomass accumulation. These metabolic effects require normoxic stabilization of the hypoxia-inducible factor-1α (HIF-1α), as silencing HIF-1α reverses the shift to aerobic glycolysis and the biosynthetic and proliferative advantages conferred by reduced AMPKα signaling. Together our findings suggest that AMPK activity opposes tumor development, and its loss fosters tumor progression in part by regulating cellular metabolic pathways that support cell growth and proliferation. PMID:23274086

  14. Tetrandrine Suppresses Cancer Angiogenesis and Metastasis in 4T1 Tumor Bearing Mice

    PubMed Central

    Gao, Jian-Li; He, Tong-Chuan; He, Kai; Chen, Su-Hong; Lv, Gui-Yuan

    2013-01-01

    Metastasis remains the most deadly aspect of cancer and still evades direct treatment. Thus, there is a great need to develop new treatment regimens to suppress tumor cells that have escaped surgical removal or that may have already disseminated. We have found that tetrandrine (TET) exhibits anticolon cancer activity. Here, we investigate the inhibition effect of TET to breast cancer metastasis, angiogenesis and its molecular basis underlying TET's anticancer activity. We compare TET with chemotherapy drug doxorubicin in 4T1 tumor bearing BALB/c mice model and find that TET exhibits an anticancer metastatic and antiangiogenic activities better than those of doxorubicin. The lung metastatic sites were decreased by TET, which is confirmed by bioluminescence imaging in vivo. On the other hand, laser doppler perfusion imaging (LDI) was used for measuring the blood flow of tumor in 4T1-tumor bearing mice. As a result, the local blood perfusion of tumor was markedly decreased by TET after 3 weeks. Mechanistically, TET treatment leads to a decrease in p-ERK level and an increase in NF-κB levels in HUVECs. TET also regulated metastatic and angiogenic related proteins, including vascular endothelial growth factor, hypoxia-inducible factor-1α, integrin β5, endothelial cell specific molecule-1, and intercellular adhesion molecule-1 in vivo. PMID:23762115

  15. Glipizide, an antidiabetic drug, suppresses tumor growth and metastasis by inhibiting angiogenesis.

    PubMed

    Qi, Cuiling; Zhou, Qin; Li, Bin; Yang, Yang; Cao, Liu; Ye, Yuxiang; Li, Jiangchao; Ding, Yi; Wang, Huiping; Wang, Jintao; He, Xiaodong; Zhang, Qianqian; Lan, Tian; Lee, Kenneth Ka Ho; Li, Weidong; Song, Xiaoyu; Zhou, Jia; Yang, Xuesong; Wang, Lijing

    2014-10-30

    Angiogenesis is involved in the development, progression and metastasis of various human cancers. Herein, we report the discovery of glipizide, a widely used drug for type 2 diabetes mellitus, as a promising anticancer agent through the inhibition of tumor angiogenesis. By high-throughput screening (HTS) of an FDA approved drug library utilizing our in vivo chick embryo chorioallantoic membrane (CAM) and yolk sac membrane (YSM) models, glipizide has been identified to significantly inhibit blood vessel formation and development. Moreover, glipizide was found to suppress tumor angiogenesis, tumor growth and metastasis using xenograft tumor and MMTV-PyMT transgenic mouse models. We further revealed that the anticancer capability of glipizide is not attributed to its antiproliferative effects, which are not significant against various human cancer cell lines. To investigate whether its anticancer efficacy is associated with the glucose level alteration induced by glipizide application, glimepiride, another medium to long-acting sulfonylurea antidiabetic drug in the same class, was employed for the comparison studies in the same fashion. Interestingly, glimepiride has demonstrated no significant impact on the tumor growth and metastasis, indicating that the anticancer effects of glipizide is not ascribed to its antidiabetic properties. Furthermore, glipizide suppresses endothelial cell migration and the formation of tubular structures, thereby inhibiting angiogenesis by up-regulating the expression of natriuretic peptide receptor A. These findings uncover a novel mechanism of glipizide as a potential cancer therapy, and also for the first time, provide direct evidence to support that treatment with glipizide may reduce the cancer risk for diabetic patients. PMID:25294818

  16. An integrated genomic approach identifies persistent tumor suppressive effects of transforming growth factor-β in human breast cancer

    PubMed Central

    2014-01-01

    Introduction Transforming growth factor-βs (TGF-βs) play a dual role in breast cancer, with context-dependent tumor-suppressive or pro-oncogenic effects. TGF-β antagonists are showing promise in early-phase clinical oncology trials to neutralize the pro-oncogenic effects. However, there is currently no way to determine whether the tumor-suppressive effects of TGF-β are still active in human breast tumors at the time of surgery and treatment, a situation that could lead to adverse therapeutic responses. Methods Using a breast cancer progression model that exemplifies the dual role of TGF-β, promoter-wide chromatin immunoprecipitation and transcriptomic approaches were applied to identify a core set of TGF-β-regulated genes that specifically reflect only the tumor-suppressor arm of the pathway. The clinical significance of this signature and the underlying biology were investigated using bioinformatic analyses in clinical breast cancer datasets, and knockdown validation approaches in tumor xenografts. Results TGF-β-driven tumor suppression was highly dependent on Smad3, and Smad3 target genes that were specifically enriched for involvement in tumor suppression were identified. Patterns of Smad3 binding reflected the preexisting active chromatin landscape, and target genes were frequently regulated in opposite directions in vitro and in vivo, highlighting the strong contextuality of TGF-β action. An in vivo-weighted TGF-β/Smad3 tumor-suppressor signature was associated with good outcome in estrogen receptor-positive breast cancer cohorts. TGF-β/Smad3 effects on cell proliferation, differentiation and ephrin signaling contributed to the observed tumor suppression. Conclusions Tumor-suppressive effects of TGF-β persist in some breast cancer patients at the time of surgery and affect clinical outcome. Carefully tailored in vitro/in vivo genomic approaches can identify such patients for exclusion from treatment with TGF-β antagonists. PMID:24890385

  17. Prolactin inhibits a major tumor-suppressive function of wild type BRCA1.

    PubMed

    Chen, Kuan-Hui Ethan; Walker, Ameae M

    2016-06-01

    Even though mutations in the tumor suppressor, BRCA1, markedly increase the risk of breast and ovarian cancer, most breast and ovarian cancers express wild type BRCA1. An important question is therefore how the tumor-suppressive function of normal BRCA1 is overcome during development of most cancers. Because prolactin promotes these and other cancers, we investigated the hypothesis that prolactin interferes with the ability of BRCA1 to inhibit the cell cycle. Examining six different cancer cell lines with wild type BRCA1, and making use of both prolactin and the growth-inhibiting selective prolactin receptor modulator, S179D PRL, we demonstrate that prolactin activation of Stat5 results in the formation of a complex between phospho-Stat5 and BRCA1. Formation of this complex does not interfere with nuclear translocation or binding of BRCA1 to the p21 promoter, but does interfere with the ability of BRCA1 to transactivate the p21 promoter. Overexpression of a dominant-negative Stat5 in prolactin-stimulated cells resulted in increased p21 expression. We conclude that prolactin inhibits a major tumor-suppressive function of BRCA1 by interfering with BRCA1's upregulation of expression of the cell cycle inhibitor, p21.

  18. JQ1 suppresses tumor growth through downregulating LDHA in ovarian cancer.

    PubMed

    Qiu, Haifeng; Jackson, Amanda L; Kilgore, Joshua E; Zhong, Yan; Chan, Leo Li-Ying; Gehrig, Paola A; Zhou, Chunxiao; Bae-Jump, Victoria L

    2015-03-30

    Amplification and overexpression of c-Myc is commonly seen in human ovarian cancers, and this could be a potentially novel therapeutic target for this disease. JQ1, a selective small-molecule BET bromodomain (BRDs) inhibitor, has been found to suppress tumor progression in several cancer cell types. Using ovarian cancer cell lines, a transgenic mouse model, and primary cell cultures from human ovarian cancer tissues, we demonstrated that JQ1 significantly suppressed cellular proliferation and induced cell cycle arrest and apoptosis in ovarian cancer cells and mouse model via targeting c-Myc. In addition, JQ1 had multiple influences on cancer metabolism, particularly in the aerobic glycolysis pathway. JQ1 reduced both the activity and phosphorylation of LDHA, inhibited lactate production, and decreased the energy supply to ovarian cancer cell lines and tumors. Taken together, our findings suggest that JQ1 is an efficacious anti-tumor agent in ovarian cancer that is associated with cell cycle arrest, induction of apoptosis and alterations of metabolism.

  19. Regulatory T cells with multiple suppressive and potentially pro-tumor activities accumulate in human colorectal cancer.

    PubMed

    Timperi, Eleonora; Pacella, Ilenia; Schinzari, Valeria; Focaccetti, Chiara; Sacco, Luca; Farelli, Francesco; Caronna, Roberto; Del Bene, Gabriella; Longo, Flavia; Ciardi, Antonio; Morelli, Sergio; Vestri, Anna Rita; Chirletti, Piero; Barnaba, Vincenzo; Piconese, Silvia

    2016-07-01

    Tregs can contribute to tumor progression by suppressing antitumor immunity. Exceptionally, in human colorectal cancer (CRC), Tregs are thought to exert beneficial roles in controlling pro-tumor chronic inflammation. The goal of our study was to characterize CRC-infiltrating Tregs at multiple levels, by phenotypical, molecular and functional evaluation of Tregs from the tumor site, compared to non-tumoral mucosa and peripheral blood of CRC patients. The frequency of Tregs was higher in mucosa than in blood, and further significantly increased in tumor. Ex vivo, those Tregs suppressed the proliferation of tumor-infiltrating CD8(+) and CD4(+) T cells. A differential compartmentalization was detected between Helios(high) and Helios(low) Treg subsets (thymus-derived versus peripherally induced): while Helios(low) Tregs were enriched in both sites, only Helios(high) Tregs accumulated significantly and specifically in tumors, displayed a highly demethylated TSDR region and contained high proportions of cells expressing CD39 and OX40, markers of activation and suppression. Besides the suppression of T cells, Tregs may contribute to CRC progression also through releasing IL-17, or differentiating into Tfr cells that potentially antagonize a protective Tfh response, events that were both detected in tumor-associated Tregs. Overall, our data indicate that Treg accumulation may contribute through multiple mechanisms to CRC establishment and progression. PMID:27622025

  20. Inhibition of histamine receptor 3 suppresses glioblastoma tumor growth, invasion, and epithelial-to-mesenchymal transition

    PubMed Central

    Cai, Wen-Ke; Yang, Yong-Xiang; Sun, Chao; Zhang, Zhuo; Xu, Yu-Qiao; Chang, Ting; Li, Zhu-Yi

    2015-01-01

    Histamine receptor 3 (H3R) is expressed in various tumors and correlated with malignancy and tumor proliferation. However, the role of H3R in tumor invasion and epithelial to mesenchymal transition (EMT) remains unknown. Here, we explored the H3R in the highly invasive glioblastoma (GBM) and U87MG cells. We found that H3R mRNA and protein levels were up-regulated in the GBM and glioma cell lines compared to normal brain tissue and astrocytes. In U87MG cell line, inhibition of H3R by siRNA or the antagonist ciproxifan (CPX) suppressed proliferation, invasiveness, and the expression of EMT activators (Snail, Slug and Twist). In addition, expression of epithelial markers (E-cadherin and ZO-1) was up-regulated and expression of mesenchymal markers (vimentin and N-cadherin) was down-regulated in vitro and in vivo in a xenograft model. In addition, we also showed that inhibition of H3R by siRNA or CPX inactivated the PI3K/Akt and MEK/ERK signaling pathways, while inhibition of Akt or ERK activity with antagonists or siRNAs suppressed H3R agonist (R)-(α)-(−)- methylhistamine dihydrobromide (RAMH) mediated invasion and reorganization of cadherin-household. In conclusion, overexpression of H3R is associated with glioma progression. Inhibition of H3R leads to suppressed invasion and EMT of GBM by inactivating the PI3K/Akt and MEK/ERK pathways in gliomas. PMID:25940798

  1. Antioxidant and Tumor Cell Suppression Potential of Premna Serratifolia Linn Leaf

    PubMed Central

    Selvam, Thamizh N.; Venkatakrishnan, V.; Damodar, Kumar S.; Elumalai, Preetham

    2012-01-01

    Herbal and natural products have been used in folk medicine for centuries throughout the world. There has been renewed interest in screening higher plants for novel biologically active compounds, particularly those that effectively intervene in human ailments in the field of chronic diseases. The present study has been taken up to evaluate the free radical scavenging activity and tumor cell suppression potential of Premna serratifolia leaf in various in vitro model systems. The methanolic extract of P. serratifolia leaf was obtained by soxhlet extraction method. The superoxide radical scavenging activity, nitric oxide radical, hydroxyl radical, DPPH radical and ABTS radical scavenging activity and lipid peroxidation were determined. The tumor cell suppression cell potential was determined in three different cancer cell lines MCF7 (breast cancer), HepG2 (liver cancer) and A549 (lung cancer) by SRB assay. The study showed that the methanolic extract of P. serratifolia was having free radical scavenging activity against superoxide radical, nitric oxide radical, hydroxyl radical, DPPH radical, ABTS radical and inhibition of lipid peroxidation. The IC50 value showed the efficacy was dose dependent. The test extract showed cytotoxic activity against MCF7, HepG2 and A549 cells. The GI50, TGI and LC50 values were determined against each cell line and compared with standard drug Adriamycin. The present study proved the free radical scavenging activity and tumor cell suppression potential of P. serratifolia leaf in the selective in vitro model systems. The further study has to be carried out in the aspects of isolation of functional molecules of the extract. PMID:22736900

  2. Targeting pioneering factor and hormone receptor cooperative pathways to suppress tumor progression

    PubMed Central

    Shah, Supriya; Prasad, Shikha; Knudsen, Karen E.

    2012-01-01

    Nuclear receptors and pioneer factors drive the development and progression of prostate cancer. In this disease, aggressive disease phenotypes and hormone therapy failures result from resurgent activity of androgen receptor (AR) and the upregulation of coactivator protein p300 and pioneer factors (e.g. GATA2 and FOXA1). Thus, a major current emphasis in the field is to identify mechanisms by which castrate-resistant AR activity and pioneer factor function can be combinatorially suppressed. Here we show that the turmeric spice isoflavone curcumin suppresses p300 and CBP occupancy at sites of AR function. Curcumin reduced the association of histone acetylation and pioneer factors, thereby suppressing AR residence and downstream target gene expression. Histone deacetylase inhibitors reversed the effects of curcumin on AR activity, further underscoring the impact of curcumin on altering the chromatin landscape. These functions precluded pioneer factor occupancy, leading ultimately to a suppression of ligand-dependent and ligand-independent AR residence on chromatin. Moreover, these functions were conserved even in cells with heightened pioneer factor activity, thus identifying a potential strategy to manage this subclass of tumors. Biological relevance was further identified using in vivo xenograft models mimicking disease progression. Curcumin cooperated in vivo with androgen deprivation as indicated by illustrated by a reduction in tumor growth and delay to the onset of castrate-resistant disease. Together, our results demonstrate the combinatorial impact of targeting AR and histone modification in prostate cancer, setting the stage for further development of curcumin as a novel agent to target AR signaling. PMID:22258452

  3. Targeting tumor-associated immune suppression with selective protein kinase A type I (PKAI) inhibitors may enhance cancer immunotherapy.

    PubMed

    Hussain, Muzammal; Shah, Zahir; Abbas, Nasir; Javeed, Aqeel; Mukhtar, Muhammad Mahmood; Zhang, Jiancun

    2016-01-01

    Despite the tremendous progress in last few years, the cancer immunotherapy has not yet improved disease-free because of the tumor-associated immune suppression being a major barrier. Novel trends to enhance cancer immunotherapy aims at harnessing the therapeutic manipulation of signaling pathways mediating the tumor-associated immune suppression, with the general aims of: (a) reversing the tumor immune suppression; (b) enhancing the innate and adaptive components of anti-tumor immunosurveillance, and (c) protecting immune cells from the suppressive effects of T regulatory cells (Tregs) and the tumor-derived immunoinhibitory mediators. A particular striking example in this context is the cyclic adenosine monophosphate (cAMP)-dependent protein kinase A type I (PKAI) pathway. Oncogenic cAMP/PKAI signaling has long been implicated in the initiation and progression of several human cancers. Emerging data indicate that cAMP/PKAI signaling also contributes to tumor- and Tregs-derived suppression of innate and adaptive arms of anti-tumor immunosurveillance. Therapeutically, selective PKAI inhibitors have been developed which have shown promising anti-cancer activity in pre-clinical and clinical settings. Rp-8-Br-cAMPS is a selective PKAI antagonist that is widely used as a biochemical tool in signal transduction research. Collateral data indicate that Rp-8-Br-cAMPS has shown immune-rescuing potential in terms of enhancing the innate and adaptive anti-tumor immunity, as well as protecting adaptive T cells from the suppressive effects of Tregs. Therefore, this proposal specifically implicates that combining selective PKAI antagonists/inhibitors with cancer immunotherapy may have multifaceted benefits, such as rescuing the endogenous anti-tumor immunity, enhancing the efficacy of cancer immunotherapy, and direct anti-cancer effects.

  4. Implication of p53-dependent cellular senescence related gene, TARSH in tumor suppression

    SciTech Connect

    Wakoh, Takeshi; Uekawa, Natsuko; Terauchi, Kunihiko; Sugimoto, Masataka; Ishigami, Akihito; Shimada, Jun-ichi; Maruyama, Mitsuo

    2009-03-20

    A novel target of NESH-SH3 (TARSH) was identified as a cellular senescence related gene in mouse embryonic fibroblasts (MEFs) replicative senescence, the expression of which has been suppressed in primary clinical lung cancer specimens. However, the molecular mechanism underlying the regulation of TARSH involved in pulmonary tumorigenesis remains unclear. Here we demonstrate that the reduction of TARSH gene expression by short hairpin RNA (shRNA) system robustly inhibited the MEFs proliferation with increase in senescence-associated {beta}-galactosidase (SA-{beta}-gal) activity. Using p53{sup -/-} MEFs, we further suggest that this growth arrest by loss of TARSH is evoked by p53-dependent p21{sup Cip1} accumulation. Moreover, we also reveal that TARSH reduction induces multicentrosome in MEFs, which is linked in chromosome instability and tumor development. These results suggest that TARSH plays an important role in proliferation of replicative senescence and may serve as a trigger of tumor development.

  5. Synergistic tumor suppression by adenovirus-mediated ING4/PTEN double gene therapy for gastric cancer.

    PubMed

    Zhang, H; Zhou, X; Xu, C; Yang, J; Xiang, J; Tao, M; Xie, Y

    2016-01-01

    Both inhibitor of growth 4 (ING4) and phosphatase and tensin homolog (PTEN) have been shown to be strong candidate tumor suppressors. However, the combined efficacy of ING4 and PTEN for human gastric cancer remains to be determined. In this report, we constructed a multiple promoter expression cassette-based recombinant adenovirus coexpressing ING4 and PTEN (AdVING4/PTEN), assessed the combined effects of AdVING4/PTEN on gastric cancer using wild-type p53 AGS and SNU-1 human gastric cancer cell lines, and elucidated its underlying mechanisms. We found that AdVING4/PTEN-induced synergistic growth inhibition and apoptosis in vitro AGS or SNU-1 tumor cells and in vivo AGS xenografted tumors subcutaneously inoculated in athymic BALB/c nude mice. Mechanistically, AdVING4/PTEN exhibited an enhanced effect on upregulation of p53, Ac-p53 (K382), P21, Bax, PUMA, Noxa, cleaved Caspase-9, cleaved Caspase-3 and cleaved PARP as well as downregulation of Bcl-2 in vitro and in vivo. In addition, AdVING4/PTEN synergistically downregulated tumor vessel CD34 expression and reduced microvessel density, and additively inhibited vascular endothelial growth factor (VEGF) expression in vivo. The synergistic tumor suppression elicited by AdVING4/PTEN was closely associated with the synergistic induction of apoptosis possibly via enhancement of endogenous p53 responses through cooperatively facilitating p53's stability and acetylation, and the synergistic inhibition of tumor angiogenesis probably via overlapping reduction of VEGF through cooperatively downregulating hypoxia inducible factor-1α's level and transcription activity. Thus, our results indicate that cancer gene therapy combining ING4 and PTEN may constitute a novel and effective therapeutic modality for human gastric cancer and other cancers.

  6. Honokiol inhibits bladder tumor growth by suppressing EZH2/miR-143 axis.

    PubMed

    Zhang, Qing; Zhao, Wei; Ye, Changxiao; Zhuang, Junlong; Chang, Cunjie; Li, Yuying; Huang, Xiaojing; Shen, Lan; Li, Yan; Cui, Yangyan; Song, Jiannan; Shen, Bing; Eliaz, Isaac; Huang, Ruimin; Ying, Hao; Guo, Hongqian; Yan, Jun

    2015-11-10

    The oncoprotein EZH2, as a histone H3K27 methyltransferase, is frequently overexpressed in various cancer types. However, the mechanisms underlying its role in urinary bladder cancer (UBC) cells have not yet fully understood. Herein, we reported that honokiol, a biologically active biphenolic compound isolated from the Magnolia officinalis inhibited human UBC cell proliferation, survival, cancer stemness, migration, and invasion, through downregulation of EZH2 expression level, along with the reductions of MMP9, CD44, Sox2 and the induction of tumor suppressor miR-143. Either EZH2 overexpression or miR-143 inhibition could partially reverse honokiol-induced cell growth arrest and impaired clonogenicity. Importantly, it was first revealed that EZH2 could directly bind to the transcriptional regulatory region of miR-143 and repress its expression. Furthermore, honokiol treatment on T24 tumor xenografts confirmed its anticancer effects in vivo, including suppression tumor growth and tumor stemness, accompanied by the dysregulation of EZH2 and miR-143 expressions. Our data suggest a promising therapeutic option to develop drugs targeting EZH2/miR-143 axis, such as honokiol, for bladder cancer treatment.

  7. Withaferin-A suppress AKT induced tumor growth in colorectal cancer cells

    PubMed Central

    Suman, Suman; Das, Trinath P.; Sirimulla, Suman; Alatassi, Houda; Ankem, Murali K.; Damodaran, Chendil

    2016-01-01

    The oncogenic activation of AKT gene has emerged as a key determinant of the aggressiveness of colorectal cancer (CRC); hence, research has focused on targeting AKT signaling for the treatment of advanced stages of CRC. In this study, we explored the anti-tumorigenic effects of withaferin A (WA) on CRC cells overexpressing AKT in preclinical (in vitro and in vivo) models. Our results indicated that WA, a natural compound, resulted in significant inhibition of AKT activity and led to the inhibition of cell proliferation, migration and invasion by downregulating the epithelial to mesenchymal transition (EMT) markers in CRC cells overexpressing AKT. The oral administration of WA significantly suppressed AKT-induced aggressive tumor growth in a xenograft model. Molecular analysis revealed that the decreased expression of AKT and its downstream pro-survival signaling molecules may be responsible for tumor inhibition. Further, significant inhibition of some important EMT markers, i.e., Snail, Slug, β-catenin and vimentin, was observed in WA-treated human CRC cells overexpressing AKT. Significant inhibition of micro-vessel formation and the length of vessels were evident in WA-treated tumors, which correlated with a low expression of the angiogenic marker RETIC. In conclusion, the present study emphasizes the crucial role of AKT activation in inducing cell proliferation, angiogenesis and EMT in CRC cells and suggests that WA may overcome AKT-induced cell proliferation and tumor growth in CRC. PMID:26883103

  8. Vaginal delivery of paclitaxel via nanoparticles with non-mucoadhesive surfaces suppresses cervical tumor growth

    PubMed Central

    Yang, Ming; Yu, Tao; Wang, Ying-Ying; Lai, Samuel K.; Zeng, Qi; Miao, Bolong; Tang, Benjamin C.; Simons, Brian W.; Ensign, Laura; Liu, Guanshu; Chan, Kannie W. Y.; Juang, Chih-Yin; Mert, Olcay; Wood, Joseph; Fu, Jie; McMahon, Michael T.; Wu, T.-C.; Hung, Chien-Fu; Hanes, Justin

    2014-01-01

    Local delivery of chemotherapeutics in the cervicovaginal tract using nanoparticles may reduce adverse side effects associated with systemic chemotherapy, while improving outcomes for early stage cervical cancer. We hypothesize drug-loaded nanoparticles must rapidly penetrate cervicovaginal mucus (CVM) lining the female reproductive tract to effectively deliver their payload to underlying diseased tissues in a uniform and sustained manner. We develop paclitaxel-loaded nanoparticles, composed entirely of polymers used in FDA-approved products, which rapidly penetrate human CVM and provide sustained drug release with minimal burst effect. We further employ a mouse model with aggressive cervical tumors established in the cervicovaginal tract to compare paclitaxel-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles (conventional particles , or CP) and similar particles coated with Pluronic® F127 (mucus-penetrating particles , or MPP). CP are mucoadhesive and, thus, aggregated in mucus, while MPP achieve more uniform distribution and close proximity to cervical tumors. Paclitaxel-MPP suppress tumor growth more effectively and prolong median survival of mice compared to free paclitaxel or paclitaxel-CP. Histopathological studies demonstrate minimal toxicity to the cervicovaginal epithelia, suggesting paclitaxel-MPP may be safe for intravaginal use. These results demonstrate for the first time the in vivo advantages of polymer-based MPP for treatment of tumors localized to a mucosal surface. PMID:24339398

  9. Kupffer cells suppress hepatocarcinogenesis and metastasis in tumor orthotopic implanted Kunming mice.

    PubMed

    Li, X Y; Wang, M Y; Zhang, J Y; Li, J Z; Gong, J P; Zhang, Wei

    2013-01-01

    In this research, we used GdCl3 (gadolinium chloride) to restrain the function of Kupffer cells and assessed effects on hepatocarcinogenesis and metastasis in the Kunming mouse. A 0.25% GdCl3 solution (10 mg/kg b.w.) was infused via the vena caudalis of each mouse 1 week before inoculation of H22 cells and was continued once per three days. Then we observed the follow indexes 3 weeks after injection of H22 cells: tumor weight, histologic characteristics of tumor tissue by light microscopy, ultramicrostructure of Kupffer cells under the electron microscope, distribution and number of Kupffer cells by histochemical staining, and TNF-α and IFN-γ levels in blood-serum and liver tissue by ELISA and RT-PCR. MMP-2 protein expression was tested by immunohistochemistry. The GdCl3 pretreatment had no effect on the quantity of Kupffer cells, but clearly restrained their functions, with decrease of TNF-α and IFN-γ levels and elevation of MMP2. Tumor immunity functions were markedly suppressed and tumor growth was accelerated with appearance of metastasis. Furthermore, survival time of trial mice was shortened.

  10. Membrane protein CNNM4–dependent Mg2+ efflux suppresses tumor progression

    PubMed Central

    Funato, Yosuke; Yamazaki, Daisuke; Mizukami, Shin; Du, Lisa; Kikuchi, Kazuya; Miki, Hiroaki

    2014-01-01

    Intracellular Mg2+ levels are strictly regulated; however, the biological importance of intracellular Mg2+ levels and the pathways that regulate them remain poorly understood. Here, we determined that intracellular Mg2+ is important in regulating both energy metabolism and tumor progression. We determined that CNNM4, a membrane protein that stimulates Mg2+ efflux, binds phosphatase of regenerating liver (PRL), which is frequently overexpressed in malignant human cancers. Biochemical analyses of cultured cells revealed that PRL prevents CNNM4-dependent Mg2+ efflux and that regulation of intracellular Mg2+ levels by PRL and CNNM4 is linked to energy metabolism and AMPK/mTOR signaling. Indeed, treatment with the clinically available mTOR inhibitor rapamycin suppressed the growth of cancer cells in which PRL was overexpressed. In ApcΔ14/+ mice, which spontaneously form benign polyps in the intestine, deletion of Cnnm4 promoted malignant progression of intestinal polyps to adenocarcinomas. IHC analyses of tissues from patients with colon cancer demonstrated an inverse relationship between CNNM4 expression and colon cancer malignancy. Together, these results indicate that CNNM4-dependent Mg2+ efflux suppresses tumor progression by regulating energy metabolism. PMID:25347473

  11. Candidate tumor suppressor B-cell translocation gene 3 impedes neoplastic progression by suppression of AKT

    PubMed Central

    Cheng, Y-C; Chen, P-H; Chiang, H-Y; Suen, C-S; Hwang, M-J; Lin, T-Y; Yang, H-C; Lin, W-C; Lai, P-L; Shieh, S-Y

    2015-01-01

    BTG3 (B-cell translocation gene 3) is a p53 target that also binds and inhibits E2F1. Although it connects two major growth-regulatory pathways functionally and is downregulated in human cancers, whether and how BTG3 acts as a tumor suppressor remain largely uncharacterized. Here we present evidence that BTG3 binds and suppresses AKT, a kinase frequently deregulated in cancers. BTG3 ablation results in increased AKT activity that phosphorylates and inhibits glycogen synthase kinase 3β. Consequently, we also observed elevated β-catenin/T-cell factor activity, upregulation of mesenchymal markers, and enhanced cell migration. Consistent with these findings, BTG3 overexpression suppressed tumor growth in mouse xenografts, and was associated with diminished AKT phosphorylation and reduced β-catenin in tissue specimens. Significantly, a short BTG3-derived peptide was identified, which recapitulates these effects in vitro and in cells. Thus, our study provides mechanistic insights into a previously unreported AKT inhibitory pathway downstream of p53. The identification of an AKT inhibitory peptide also unveils a new avenue for cancer therapeutics development. PMID:25569101

  12. NF-κB functions as a molecular link between tumor cells and Th1/Tc1 T cells in the tumor microenvironment to exert radiation-mediated tumor suppression

    PubMed Central

    Simon, Priscilla S.; Bardhan, Kankana; Chen, May R.; Paschall, Amy V.; Lu, Chunwan; Bollag, Roni J.; Kong, Feng-Chong; Jin, JianYue; Kong, Feng-Ming; Waller, Jennifer L.; Pollock, Raphael E.; Liu, Kebin

    2016-01-01

    Radiation modulates both tumor cells and immune cells in the tumor microenvironment to exert its anti-tumor activity; however, the molecular connection between tumor cells and immune cells that mediates radiation-exerted tumor suppression activity in the tumor microenvironment is largely unknown. We report here that radiation induces rapid activation of the p65/p50 and p50/p50 NF-κB complexes in human soft tissue sarcoma (STS) cells. Radiation-activated p65/p50 and p50/p50 bind to the TNFα promoter to activate its transcription in STS cells. Radiation-induced TNFα induces tumor cell death in an autocrine manner. A sublethal dose of Smac mimetic BV6 induces cIAP1 and cIAP2 degradation to increase tumor cell sensitivity to radiation-induced cell death in vitro and to enhance radiation-mediated suppression of STS xenografts in vivo. Inhibition of caspases, RIP1, or RIP3 blocks radiation/TNFα-induced cell death, whereas inhibition of RIP1 blocks TNFα-induced caspase activation, suggesting that caspases and RIP1 act sequentially to mediate the non-compensatory cell death pathways. Furthermore, we determined in a syngeneic sarcoma mouse model that radiation up-regulates IRF3, IFNβ, and the T cell chemokines CCL2 and CCL5 in the tumor microenvironment, which are associated with activation and increased infiltration of Th1/Tc1 T cells in the tumor microenvironment. Moreover, tumor-infiltrating T cells are in their active form since both the perforin and FasL pathways are activated in irradiated tumor tissues. Consequently, combined BV6 and radiation completely suppressed tumor growth in vivo. Therefore, radiation-induced NF-κB functions as a molecular link between tumor cells and immune cells in the tumor microenvironment for radiation-mediated tumor suppression. PMID:27014915

  13. Boswellia sacra essential oil induces tumor cell-specific apoptosis and suppresses tumor aggressiveness in cultured human breast cancer cells

    PubMed Central

    2011-01-01

    Background Gum resins obtained from trees of the Burseraceae family (Boswellia sp.) are important ingredients in incense and perfumes. Extracts prepared from Boswellia sp. gum resins have been shown to possess anti-inflammatory and anti-neoplastic effects. Essential oil prepared by distillation of the gum resin traditionally used for aromatic therapy has also been shown to have tumor cell-specific anti-proliferative and pro-apoptotic activities. The objective of this study was to optimize conditions for preparing Boswellea sacra essential oil with the highest biological activity in inducing tumor cell-specific cytotoxicity and suppressing aggressive tumor phenotypes in human breast cancer cells. Methods Boswellia sacra essential oil was prepared from Omani Hougari grade resins through hydrodistillation at 78 or 100 oC for 12 hours. Chemical compositions were identified by gas chromatography-mass spectrometry; and total boswellic acids contents were quantified by high-performance liquid chromatography. Boswellia sacra essential oil-mediated cell viability and death were studied in established human breast cancer cell lines (T47D, MCF7, MDA-MB-231) and an immortalized normal human breast cell line (MCF10-2A). Apoptosis was assayed by genomic DNA fragmentation. Anti-invasive and anti-multicellular tumor properties were evaluated by cellular network and spheroid formation models, respectively. Western blot analysis was performed to study Boswellia sacra essential oil-regulated proteins involved in apoptosis, signaling pathways, and cell cycle regulation. Results More abundant high molecular weight compounds, including boswellic acids, were present in Boswellia sacra essential oil prepared at 100 oC hydrodistillation. All three human breast cancer cell lines were sensitive to essential oil treatment with reduced cell viability and elevated cell death, whereas the immortalized normal human breast cell line was more resistant to essential oil treatment. Boswellia sacra

  14. miR-542-3p exerts tumor suppressive functions in neuroblastoma by downregulating Survivin.

    PubMed

    Althoff, Kristina; Lindner, Sven; Odersky, Andrea; Mestdagh, Pieter; Beckers, Anneleen; Karczewski, Sarah; Molenaar, Jan J; Bohrer, Anna; Knauer, Shirley; Speleman, Frank; Epple, Matthias; Kozlova, Diana; Yoon, Sena; Baek, Kwanghee; Vandesompele, Jo; Eggert, Angelika; Schramm, Alexander; Schulte, Johannes H

    2015-03-15

    MicroRNAs (miRNAs) are deregulated in a variety of human cancers, including neuroblastoma, the most common extracranial tumor of childhood. We previously reported a signature of 42 miRNAs to be highly predictive of neuroblastoma outcome. One miRNA in this signature, miR-542, was downregulated in tumors from patients with adverse outcome. Reanalysis of quantitative PCR and next-generation sequencing transcript data revealed that miR-542-5p as well as miR-542-3p expression is inversely correlated with poor prognosis in neuroblastoma patients. We, therefore, analyzed the function of miR-542 in neuroblastoma tumor biology. Ectopic expression of miR-542-3p in neuroblastoma cell lines reduced cell viability and proliferation, induced apoptosis and downregulated Survivin. Survivin expression was also inversely correlated with miR-542-3p expression in primary neuroblastomas. Reporter assays confirmed that miR-542-3p directly targeted Survivin. Downregulating Survivin using siRNA copied the phenotype of miR-542-3p expression in neuroblastoma cell lines, while cDNA-mediated ectopic expression of Survivin partially rescued the phenotype induced by miR-542-3p expression. Treating nude mice bearing neuroblastoma xenografts with miR-542-3p-loaded nanoparticles repressed Survivin expression, decreased cell proliferation and induced apoptosis in the respective xenograft tumors. We conclude that miR-542-3p exerts its tumor suppressive function in neuroblastoma, at least in part, by targeting Survivin. Expression of miR-542-3p could be a promising therapeutic strategy for treating aggressive neuroblastoma.

  15. Hsa-miR-623 suppresses tumor progression in human lung adenocarcinoma

    PubMed Central

    Wei, Shuang; Zhang, Zun-yi; Fu, Sheng-ling; Xie, Jun-gang; Liu, Xian-sheng; Xu, Yong-jian; Zhao, Jian-ping; Xiong, Wei-ning

    2016-01-01

    Our previous study revealed that Ku80 was overexpressed in lung cancer tissues and hsa-miR-623 regulated the Ku80 expression; however, the detailed function of hsa-miR-623 in lung cancer was unclear. We identified that hsa-miR-623 bound to the 3'-UTR of Ku80 mRNA, thus significantly decreasing Ku80 expression in lung adenocarcinoma cells. Hsa-miR-623 was downregulated in lung adenocarcinoma tissues compared with corresponding non-tumorous tissues, and its expression was inversely correlated with Ku80 upregulation. Downregulation of hsa-miR-623 was associated with poor clinical outcomes of lung adenocarcinoma patients. Hsa-miR-623 suppressed lung adenocarcinoma cell proliferation, clonogenicity, migration and invasion in vitro. Hsa-miR-623 inhibited xenografts growth and metastasis of lung adenocarcinoma in vivo. Ku80 knockdown in lung adenocarcinoma cells suppressed tumor properties in vitro and in vivo similar to hsa-miR-623 overexpression. Further, hsa-miR-623 overexpression decreased matrix metalloproteinase-2 (MMP-2) and MMP-9 expression levels, with decreased ERK/JNK phosphorylation. Inhibition of hsa-miR-623 or overexpression of Ku80 promoted lung adenocarcinoma cell invasion, activated ERK/JNK phosphorylation and increased MMP-2/9 expressions, which could be reversed by ERK kinase inhibitor or JNK kinase inhibitor. In summary, our results showed that hsa-miR-623 was downregulated in lung adenocarcinoma and suppressed the invasion and metastasis targeting Ku80 through ERK/JNK inactivation mediated downregulation of MMP-2/9. These findings reveal that hsa-miR-623 may serve as an important therapeutic target in lung cancer therapy. PMID:27685632

  16. Biodegradable polymeric micelle-encapsulated quercetin suppresses tumor growth and metastasis in both transgenic zebrafish and mouse models

    NASA Astrophysics Data System (ADS)

    Wu, Qinjie; Deng, Senyi; Li, Ling; Sun, Lu; Yang, Xi; Liu, Xinyu; Liu, Lei; Qian, Zhiyong; Wei, Yuquan; Gong, Changyang

    2013-11-01

    Quercetin (Que) loaded polymeric micelles were prepared to obtain an aqueous formulation of Que with enhanced anti-tumor and anti-metastasis activities. A simple solid dispersion method was used, and the obtained Que micelles had a small particle size (about 31 nm), high drug loading, and high encapsulation efficiency. Que micelles showed improved cellular uptake, an enhanced apoptosis induction effect, and stronger inhibitory effects on proliferation, migration, and invasion of 4T1 cells than free Que. The enhanced in vitro antiangiogenesis effects of Que micelles were proved by the results that Que micelles significantly suppressed proliferation, migration, invasion, and tube formation of human umbilical vein endothelial cells (HUVECs). Subsequently, transgenic zebrafish models were employed to investigate anti-tumor and anti-metastasis effects of Que micelles, in which stronger inhibitory effects of Que micelles were observed on embryonic angiogenesis, tumor-induced angiogenesis, tumor growth, and tumor metastasis. Furthermore, in a subcutaneous 4T1 tumor model, Que micelles were more effective in suppressing tumor growth and spontaneous pulmonary metastasis, and prolonging the survival of tumor-bearing mice. Besides, immunohistochemical and immunofluorescent assays suggested that tumors in the Que micelle-treated group showed more apoptosis, fewer microvessels, and fewer proliferation-positive cells. In conclusion, Que micelles, which are synthesized as an aqueous formulation of Que, possess enhanced anti-tumor and anti-metastasis activity, which can serve as potential candidates for cancer therapy.

  17. Tumor suppressive miR-124 targets androgen receptor and inhibits proliferation of prostate cancer cells

    PubMed Central

    Shi, Xu-Bao; Xue, Lingru; Ma, Ai-Hong; Tepper, Clifford G.; Gandour-Edwards, Regina; Kung, Hsing-Jien; deVere White, Ralph W.

    2014-01-01

    Although prostate cancer (CaP) is the most frequently diagnosed malignant tumor in American men, the mechanisms underlying the development and progression of CaP remain largely unknown. Recent studies have shown that downregulation of miR-124 occurs in several types of human cancer, suggesting a tumor suppressive function of miR-124. Until now, however, it has been unclear whether miR-124 is associated with CaP. In the present study, we completed a series of experiments to understand the functional role of miR-124 in CaP. We detected the expression level of miR-124 in clinical CaP tissues, evaluated the influence of miR-124 on the growth of CaP cells, and investigated the mechanism underlying the dysregulation of miR-124. We found that i) miR-124 directly targets the androgen receptor (AR) and subsequently induces a upregulation of p53; ii) miR-124 is significantly down-regulated in malignant prostatic cells compared to that in benign cells and DNA methylation causes the reduced expression of miR-124; and iii) miR-124 can inhibit the growth of CaP cells in vitro and in vivo. Data from this study revealed that loss of miR-124 expression is a common event in CaP, which may contribute to pathogenesis of CaP. Our studies also suggest that miR-124 is a potential tumor suppressive gene in CaP, and restoration of miR-124 expression may represent a novel strategy for CaP therapy. PMID:23069658

  18. NPAS3 Demonstrates Features of a Tumor Suppressive Role in Driving the Progression of Astrocytomas

    PubMed Central

    Moreira, Frederico; Kiehl, Tim-Rasmus; So, Kelvin; Ajeawung, Norbert F.; Honculada, Carmelita; Gould, Peter; Pieper, Russell O.; Kamnasaran, Deepak

    2011-01-01

    Malignant astrocytomas, the most common primary brain tumors, are predominantly fatal. Improved treatments will require a better understanding of the biological features of high-grade astrocytomas. To better understand the role of neuronal PAS 3 (NPAS3) in diseases in human beings, it was investigated as a candidate for astrocytomagenesis based on the presence of aberrant protein expression in greater than 70% of a human astrocytoma panel (n = 433) and most notably in surgically resected malignant lesions. In subsequent functional studies, it was concluded that NPAS3 exhibits features of a tumor-suppressor, which drives the progression of astrocytomas by modulating the cell cycle, proliferation, apoptosis, and cell migration/invasion and has a further influence on the viability of endothelial cells. Of clinical importance, absence of NPAS3 expression in glioblastomas was a significantly negative prognostic marker of survival. In addition, malignant astrocytomas lacking NPAS3 expression demonstrated loss of function mutations, which were associated with loss of heterozygosity. While overexpressed NPAS3 in malignant glioma cell lines significantly suppressed transformation, the converse decreased expression considerably induced more aggressive growth. In addition, knockdown NPAS3 expression in a human astrocyte cell line in concert with the human papillomavirus E6 and E7 oncogenes induced growth of malignant astrocytomas. In conclusion, NPAS3 drives the progression of human malignant astrocytomas as a tumor suppressor and is a negative prognostication marker for survival. PMID:21703424

  19. Epithelial-mesenchymal transition can suppress major attributes of human epithelial tumor-initiating cells

    PubMed Central

    Celià-Terrassa, Toni; Meca-Cortés, Óscar; Mateo, Francesca; Martínez de Paz, Alexia; Rubio, Nuria; Arnal-Estapé, Anna; Ell, Brian J.; Bermudo, Raquel; Díaz, Alba; Guerra-Rebollo, Marta; Lozano, Juan José; Estarás, Conchi; Ulloa, Catalina; ρlvarez-Simón, Daniel; Milà, Jordi; Vilella, Ramón; Paciucci, Rosanna; Martínez-Balbás, Marian; García de Herreros, Antonio; Gomis, Roger R.; Kang, Yibin; Blanco, Jerónimo; Fernández, Pedro L.; Thomson, Timothy M.

    2012-01-01

    Malignant progression in cancer requires populations of tumor-initiating cells (TICs) endowed with unlimited self renewal, survival under stress, and establishment of distant metastases. Additionally, the acquisition of invasive properties driven by epithelial-mesenchymal transition (EMT) is critical for the evolution of neoplastic cells into fully metastatic populations. Here, we characterize 2 human cellular models derived from prostate and bladder cancer cell lines to better understand the relationship between TIC and EMT programs in local invasiveness and distant metastasis. The model tumor subpopulations that expressed a strong epithelial gene program were enriched in highly metastatic TICs, while a second subpopulation with stable mesenchymal traits was impoverished in TICs. Constitutive overexpression of the transcription factor Snai1 in the epithelial/TIC-enriched populations engaged a mesenchymal gene program and suppressed their self renewal and metastatic phenotypes. Conversely, knockdown of EMT factors in the mesenchymal-like prostate cancer cell subpopulation caused a gain in epithelial features and properties of TICs. Both tumor cell subpopulations cooperated so that the nonmetastatic mesenchymal-like prostate cancer subpopulation enhanced the in vitro invasiveness of the metastatic epithelial subpopulation and, in vivo, promoted the escape of the latter from primary implantation sites and accelerated their metastatic colonization. Our models provide new insights into how dynamic interactions among epithelial, self-renewal, and mesenchymal gene programs determine the plasticity of epithelial TICs. PMID:22505459

  20. Cell cycle restriction is more important than apoptosis induction for RASSF1A protein tumor suppression.

    PubMed

    Donninger, Howard; Clark, Jennifer A; Monaghan, Megan K; Schmidt, M Lee; Vos, Michele; Clark, Geoffrey J

    2014-11-01

    The Ras association domain family protein 1A (RASSF1A) is arguably one of the most frequently inactivated tumor suppressors in human cancer. RASSF1A modulates apoptosis via the Hippo and Bax pathways but also modulates the cell cycle. In part, cell cycle regulation appears to be dependent upon the ability of RASSF1A to complex with microtubules and regulate their dynamics. Which property of RASSF1A, apoptosis induction or microtubule regulation, is responsible for its tumor suppressor function is not known. We have identified a short conserved motif that is essential for the binding of RASSF family proteins with microtubule-associated proteins. By making a single point mutation in the motif, we were able to generate a RASSF1A variant that retains wild-type apoptotic properties but completely loses the ability to bind microtubule-associated proteins and complex with microtubules. Comparison of this mutant to wild-type RASSF1A showed that, despite retaining its proapoptotic properties, the mutant was completely unable to induce cell cycle arrest or suppress the tumorigenic phenotype. Therefore, it appears that the cell cycle/microtubule effects of RASSF1A are key to its tumor suppressor function rather than its apoptotic effects.

  1. Suppression of KSHV-induced angiopoietin-2 inhibits angiogenesis, infiltration of inflammatory cells, and tumor growth.

    PubMed

    Yu, Xiaolan; Sha, Jingfeng; Xiang, Shao; Qin, Sanhai; Conrad, Patricia; Ghosh, Santosh K; Weinberg, Aaron; Ye, Fengchun

    2016-08-01

    Kaposi's sarcoma (KS) is a highly angiogenic and inflammatory neoplasia. The angiogenic and inflammatory cytokine angiopoietin-2 (Ang-2) is strongly expressed in KS due to Kaposi's sarcoma-associated herpesvirus (KSHV) infection. In the present study, we determined how Ang-2 contributes to development of KS by using telomerase-immortalized human umbilical vein endothelial cells (TIVE) as a model, which become malignantly transformed and express increased levels of Ang-2 following KSHV infection. Ang-2 released from TIVE-KSHV cells induces tyrosine phosphorylation of Tie-2 receptor from both human and mouse endothelial cells and promotes angiogenesis in nude mice. Functional inhibition or expressional "knock-down" of Ang-2 in these cells blocks angiogenesis and inhibits tumor growth. Ang-2 suppression also reduces the numbers of infiltrating monocytes/macrophages in tumors. In transwell-based cell migration assays, Ang-2 indeed enhances migration of human monocytes in a dose-dependent manner. These results underscore a pivotal role of KSHV-induced Ang-2 in KS tumor development by promoting both angiogenesis and inflammation. Our data also suggest that selective drug targeting of Ang-2 may be used for treatment of KS. PMID:27294705

  2. Tumor suppression by a rationally designed reversible inhibitor of methionine aminopeptidase-2.

    PubMed

    Wang, Jieyi; Sheppard, George S; Lou, Pingping; Kawai, Megumi; BaMaung, Nwe; Erickson, Scott A; Tucker-Garcia, Lora; Park, Chang; Bouska, Jennifer; Wang, Yi-Chun; Frost, David; Tapang, Paul; Albert, Daniel H; Morgan, Sherry J; Morowitz, Michael; Shusterman, Suzanne; Maris, John M; Lesniewski, Rick; Henkin, Jack

    2003-11-15

    Methionine aminopeptidase (MetAP)-2 has been suggested as a novel target for cancer therapy because the anticancer agent TNP-470 irreversibly inactivates the catalytic activity of this enzyme. However, the importance of MetAP2 in cell growth and tumor progression was uncertain because previous data were based on the chemically reactive TNP-470. Here we show that a rationally designed reversible MetAP2 inhibitor, A-357300, suppresses tumor growth preclinically without the toxicities observed with TNP-470. We have synthesized this bestatin-type MetAP2 inhibitor with the aid of crystal structures of the enzyme-inhibitor complexes and parallel synthesis. A-357300 induces cytostasis by cell cycle arrest at the G(1) phase selectively in endothelial cells and in a subset of tumor cells, but not in most primary cells of nonendothelial type. A-357300 inhibits angiogenesis both in vitro and in vivo and shows potent antitumor efficacy in carcinoma, sarcoma, and neuroblastoma murine models. These data affirm that MetAP2 plays a pivotal role in cell growth and establish that reversible MetAP2 inhibitors are promising novel cancer therapeutic agents.

  3. Tumor microenvironment (TME)-driven immune suppression in B cell malignancy.

    PubMed

    Nicholas, Nicole S; Apollonio, Benedetta; Ramsay, Alan G

    2016-03-01

    Immune checkpoint blockade antibodies and immunomodulatory drugs can unleash anti-tumor T cell immunity and mediate durable cancer regressions. However, only a fraction of patients currently respond to immunotherapy. Lymphoid malignancies are known to have clinically exploitable immune sensitivity and their intrinsic lymphoid tumor-microenvironment (TME) should make them natural targets for immunotherapy. However, accumulating evidence is showing that malignant cells engage in novel associations/interdependencies with reprogrammed immune and stromal cells in the TME that provide crucial contributions to the licencing of tumour progression and immune evasion (suppression of antitumor immune responses). In this review, we outline TME-driven contributions to the licencing of immune evasion mechanisms including the expression and activity of the immune checkpoint network, focussing on two types of B cell malignancy: indolent chronic lymphocytic leukemia (CLL) and aggressive diffuse large B-cell lymphoma (DLBCL). We also highlight recent therapeutic strategies to re-educate the TME to have anti-tumorigenic effects. This article is part of a Special Issue entitled: Tumor Microenvironment Regulation of Cancer Cell Survival, Metastasis, Inflammation, and Immune Surveillance edited by Peter Ruvolo and Gregg L. Semenza.

  4. Effect of tumor-derived cytokines and growth factors on differentiation and immune suppressive features of myeloid cells in cancer

    PubMed Central

    Kusmartsev, Sergei; Gabrilovich, Dmitry I.

    2006-01-01

    It is well established that cancers affect differentiation of dendritic cells and promote systemic expansion of immune suppressive immature myeloid cells. This phenomenon may represent a mechanism of tumor escape from immune attack and could have significant impact on tumor progression. In this review we discuss the role of different tumor-derived factors, which were implicated in abnormal myeloid cell differentiation. The role of reactive oxygen species as well as JAK/STAT signaling in mechanisms of the effects of tumor-derived factors on myeloid cells is also discussed. PMID:16983515

  5. A novel isoform of the 8p22 tumor suppressor gene DLC1 suppresses tumor growth and is frequently silenced in multiple common tumors.

    PubMed

    Low, J S W; Tao, Q; Ng, K M; Goh, H K; Shu, X-S; Woo, W L; Ambinder, R F; Srivastava, G; Shamay, M; Chan, A T C; Popescu, N C; Hsieh, W-S

    2011-04-21

    The critical 8p22 tumor suppressor deleted in liver cancer 1 (DLC1) is frequently inactivated by aberrant CpG methylation and/or genetic deletion and implicated in tumorigeneses of multiple tumor types. Here, we report the identification and characterization of its new isoform, DLC1 isoform 4 (DLC1-i4). This novel isoform encodes an 1125-aa (amino acid) protein with distinct N-terminus as compared with other known DLC1 isoforms. Similar to other isoforms, DLC1-i4 is expressed ubiquitously in normal tissues and immortalized normal epithelial cells, suggesting a role as a major DLC1 transcript. However, differential expression of the four DLC1 isoforms is found in tumor cell lines: Isoform 1 (longest) and 3 (short thus probably nonfunctional) share a promoter and are silenced in almost all cancer and immortalized cell lines, whereas isoform 2 and 4 utilize different promoters and are frequently downregulated. DLC1-i4 is significantly downregulated in multiple carcinoma cell lines, including 2/4 nasopharyngeal, 8/16 (50%) esophageal, 4/16 (25%) gastric, 6/9 (67%) breast, 3/4 colorectal, 4/4 cervical and 2/8(25%) lung carcinoma cell lines. The functional DLC1-i4 promoter is within a CpG island and is activated by wild-type p53. CpG methylation of the DLC1-i4 promoter is associated with its silencing in tumor cells and was detected in 38-100% of multiple primary tumors. Treatment with 5-aza-2'-deoxycytidine or genetic double knockout of DNMT1 and DNMT3B led to demethylation of the promoter and reactivation of its expression, indicating a predominantly epigenetic mechanism of silencing. Ectopic expression of DLC1-i4 in silenced tumor cells strongly inhibited their growth and colony formation. Thus, we identified a new isoform of DLC1 with tumor suppressive function. The differential expression of various DLC1 isoforms suggests interplay in modulating the complex activities of DLC1 during carcinogenesis. PMID:21217778

  6. Overexpression of iron regulatory protein 1 suppresses growth of tumor xenografts.

    PubMed

    Chen, Guohua; Fillebeen, Carine; Wang, Jian; Pantopoulos, Kostas

    2007-04-01

    Iron is essential for proliferation of normal and neoplastic cells. Cellular iron uptake, utilization and storage are regulated by transcriptional and post-transcriptional mechanisms. We hypothesized that the disruption of iron homeostasis may modulate the growth properties of cancer cells. To address this, we employed H1299 lung cancer cells engineered for tetracycline-inducible overexpression of the post-transcriptional regulator iron regulatory protein 1 (IRP1). The induction of IRP1 (wild-type or the constitutive IRP1(C437S) mutant) did not affect the proliferation of the cells in culture, and only modestly reduced their efficiency to form colonies in soft agar. However, IRP1 dramatically impaired the capacity of the cells to form solid tumor xenografts in nude mice. Tumors derived from IRP1-transfectants were <20% in size compared to those from parent cells. IRP1 coordinately controls the expression of transferrin receptor 1 (TfR1) and ferritin by binding to iron-responsive elements (IREs) within their mRNAs. Biochemical analysis revealed high expression of epitope-tagged IRP1 in tumor tissue, which was associated with a profound increase in IRE-binding activity. As expected, this response misregulated iron metabolism by increasing TfR1 levels. Surprisingly, IRP1 failed to suppress ferritin expression and did not affect the levels of the iron transporter ferroportin. Our results show that the overexpression of IRP1 is associated with an apparent tumor suppressor phenotype and provide a direct regulatory link between the IRE/IRP system and cancer.

  7. Morphine Suppresses Tumor Angiogenesis through a HIF-1α/p38MAPK Pathway

    PubMed Central

    Koodie, Lisa; Ramakrishnan, Sundaram; Roy, Sabita

    2010-01-01

    Morphine, a highly potent analgesic agent, is frequently prescribed for moderate to severe cancer pain. In this study, morphine was administered at a clinically relevant analgesic dose to assess tumor cell-induced angiogenesis and subcutaneous tumor growth in nude mice using mouse Lewis lung carcinoma cells (LLCs). Implantation of mice with a continuous slow-release morphine pellet achieved morphine plasma levels within 250–400 ng/ml (measured using a radioimmunoassay, Coat-A-Count Serum Morphine) and was sufficient to significantly reduce tumor cell-induced angiogenesis and tumor growth when compared with placebo treatment. Morphometric analysis for blood vessel formation further confirmed that morphine significantly reduced blood vessel density (P < 0.003), vessel branching (P < 0.05), and vessel length (P < 0.002) when compared with placebo treatment. Morphine’s effect was abolished in mice coadministered the classical opioid receptor antagonist, naltrexone, and in mu-opioid receptor knockout mice, supporting the involvement of the classical opioid receptors in vivo. Morphine’s inhibitory effect is mediated through the suppression of the hypoxia-induced mitochondrial p38 mitogen-activated protein kinase (MAPK) pathway. Our results suggest that in vitro morphine treatment of LLCs inhibits the hypoxia-induced nuclear translocation of hypoxia-inducible transcription factor 1α to reduce vascular endothelial growth factor transcription and secretion, in a manner similar to pharmacological blockade with the p38 MAPK-specific inhibitor, SB203585. These studies indicate that morphine, in addition to its analgesic function, may be exploited for its antiangiogenic potential. PMID:20616349

  8. Suppressing tumor progression of in vitro prostate cancer cells by emitted psychosomatic power through Zen meditation.

    PubMed

    Yu, Tiing; Tsai, Hui Ling; Hwang, Ming Liang

    2003-01-01

    Human prostate cancer PC3 cells were treated in vitro with psychosomatic power emitted by a Buddhist-Zen Master. A significant decrease of growth rate was observed as determined by MTT assay after 48 hours. These cells also had two- to three-fold higher levels of prostatic acid phosphatase (PAcP) activity, a prostate tissue-specific differentiation antigen. In addition, the treated cells formed fewer and smaller colonies in soft agar as compared with control cells, which displayed anchorage-independent growth. These observations provide insight into the suppressive effects of healing power through the practice of Buddhist-Zen meditation on tumor progression. The emitted bioenergy may be suggested as an alternative and feasible approach for cancer research and patient treatment.

  9. Investigating the Expression of Oncogenic and Tumor Suppressive MicroRNA in DLBCL.

    PubMed

    Handal, Brian; Enlow, Rossanna; Lara, Daniel; Bailey, Mark; Vega, Francisco; Hu, Peter; Lennon, Alan

    2013-01-01

    Diffuse Large B-cell Lymphoma (DLBCL) is the most common form of lymphoma, accounting for 40 percent of newly diagnosed cases each year. DLBCL is an aggressive abnormal growth of tissue characterized by the accumulation of abnormal B-lymphocytes in the lymphatics of affected individuals. The goal of this study was to analyze microRNA (miRNA) as an alternative method of diagnosis and treatment for patients affected with the observed cancer. MiRNAs are small, non-coding, endogenous RNA that control gene expression at the post-transcriptional level. Emerging evidence suggests that miRNA-mediated gene regulation has a functional role in cancer and could prove to be crucial targets for therapeutic intervention. Here, we provide a quantitative study on the expression of a diverse class of oncogenic and tumor suppressive miRNA that have shown to regulate oncoproteins involved in differentiation, proliferation, and/or apoptosis.

  10. Myo9b is a key player in SLIT/ROBO-mediated lung tumor suppression

    PubMed Central

    Kong, Ruirui; Yi, Fengshuang; Wen, Pushuai; Liu, Jianghong; Chen, Xiaoping; Ren, Jinqi; Li, Xiaofei; Shang, Yulong; Nie, Yongzhan; Wu, Kaichun; Fan, Daiming; Zhu, Li; Feng, Wei; Wu, Jane Y.

    2015-01-01

    Emerging evidence indicates that the neuronal guidance molecule SLIT plays a role in tumor suppression, as SLIT-encoding genes are inactivated in several types of cancer, including lung cancer; however, it is not clear how SLIT functions in lung cancer. Here, our data show that SLIT inhibits cancer cell migration by activating RhoA and that myosin 9b (Myo9b) is a ROBO-interacting protein that suppresses RhoA activity in lung cancer cells. Structural analyses revealed that the RhoGAP domain of Myo9b contains a unique patch that specifically recognizes RhoA. We also determined that the ROBO intracellular domain interacts with the Myo9b RhoGAP domain and inhibits its activity; therefore, SLIT-dependent activation of RhoA is mediated by ROBO inhibition of Myo9b. In a murine model, compared with control lung cancer cells, SLIT-expressing cells had a decreased capacity for tumor formation and lung metastasis. Evaluation of human lung cancer and adjacent nontumor tissues revealed that Myo9b is upregulated in the cancer tissue. Moreover, elevated Myo9b expression was associated with lung cancer progression and poor prognosis. Together, our data identify Myo9b as a key player in lung cancer and as a ROBO-interacting protein in what is, to the best of our knowledge, a newly defined SLIT/ROBO/Myo9b/RhoA signaling pathway that restricts lung cancer progression and metastasis. Additionally, our work suggests that targeting the SLIT/ROBO/Myo9b/RhoA pathway has potential as a diagnostic and therapeutic strategy for lung cancer. PMID:26529257

  11. Crocin suppresses tumor necrosis factor-alpha-induced cell death of neuronally differentiated PC-12 cells.

    PubMed

    Soeda, S; Ochiai, T; Paopong, L; Tanaka, H; Shoyama, Y; Shimeno, H

    2001-11-01

    Crocus sativus L. is used in Chinese traditional medicine to treat some disorders of the central nervous system. Crocin is an ethanol-extractable component of Crocus sativus L.; it is reported to prevent ethanol-induced impairment of learning and memory in mice. In this study, we demonstrate that crocin suppresses the effect of tumor necrosis factor (TNF)-alpha on neuronally differentiated PC-12 cells. PC-12 cells dead from exposure to TNF-alpha show apoptotic morphological changes and DNA fragmentation. These hallmark features of cell death did not appear in cells treated in the co-presence of 10 microM crocin. Moreover, crocin suppressed the TNF-alpha-induced expression of Bcl-Xs and LICE mRNAs and simultaneously restored the cytokine-induced reduction of Bcl-X(L) mRNA expression. The modulating effects of crocin on the expression of Bcl-2 family proteins led to a marked reduction of a TNF-alpha-induced release of cytochrome c from the mitochondria. Crocin also blocked the cytochrome c-induced activation of caspase-3. To learn how crocin exhibits these anti-apoptotic actions in PC-12 cells, we tested the effect of crocin on PC-12 cell death induced by daunorubicin. We found that crocin inhibited the effect of daunorubicin as well. Our findings suggest that crocin inhibits neuronal cell death induced by both internal and external apoptotic stimuli.

  12. Brain tumor regulates neuromuscular synapse growth and endocytosis in Drosophila by suppressing mad expression.

    PubMed

    Shi, Wenwen; Chen, Yan; Gan, Guangming; Wang, Dan; Ren, Jinqi; Wang, Qifu; Xu, Zhiheng; Xie, Wei; Zhang, Yong Q

    2013-07-24

    The precise regulation of synaptic growth is critical for the proper formation and plasticity of functional neural circuits. Identification and characterization of factors that regulate synaptic growth and function have been under intensive investigation. Here we report that brain tumor (brat), which was identified as a translational repressor in multiple biological processes, plays a crucial role at Drosophila neuromuscular junction (NMJ) synapses. Immunohistochemical analysis demonstrated that brat mutants exhibited synaptic overgrowth characterized by excess satellite boutons at NMJ terminals, whereas electron microscopy revealed increased synaptic vesicle size but reduced density at active zones compared with wild-types. Spontaneous miniature excitatory junctional potential amplitudes were larger and evoked quantal content was lower at brat mutant NMJs. In agreement with the morphological and physiological phenotypes, loss of Brat resulted in reduced FM1-43 uptake at the NMJ terminals, indicating that brat regulates synaptic endocytosis. Genetic analysis revealed that the actions of Brat at synapses are mediated through mothers against decapentaplegic (Mad), the signal transduction effector of the bone morphogenetic protein (BMP) signaling pathway. Furthermore, biochemical analyses showed upregulated levels of Mad protein but normal mRNA levels in the larval brains of brat mutants, suggesting that Brat suppresses Mad translation. Consistently, knockdown of brat by RNA interference in Drosophila S2 cells also increased Mad protein level. These results together reveal an important and previously unidentified role for Brat in synaptic development and endocytosis mediated by suppression of BMP signaling. PMID:23884941

  13. Kaempferol suppresses bladder cancer tumor growth by inhibiting cell proliferation and inducing apoptosis.

    PubMed

    Dang, Qiang; Song, Wenbin; Xu, Defeng; Ma, Yanmin; Li, Feng; Zeng, Jin; Zhu, Guodong; Wang, Xinyang; Chang, Luke S; He, Dalin; Li, Lei

    2015-09-01

    The effects of the flavonoid compound, kaempferol, which is an inhibitor of cancer cell proliferation and an inducer of cell apoptosis have been shown in various cancers, including lung, pancreatic, and ovarian, but its effect has never been studied in bladder cancer. Here, we investigated the effects of kaempferol on bladder cancer using multiple in vitro cell lines and in vivo mice studies. The MTT assay results on various bladder cancer cell lines showed that kaempferol enhanced bladder cancer cell cytotoxicity. In contrast, when analyzed by the flow cytometric analysis, DNA ladder experiment, and TUNEL assay, kaempferol significantly was shown to induce apoptosis and cell cycle arrest. These in vitro results were confirmed in in vivo mice studies using subcutaneous xenografted mouse models. Consistent with the in vitro results, we found that treating mice with kaempferol significant suppression in tumor growth compared to the control group mice. Tumor tissue staining results showed decreased expressions of the growth related markers, yet increased expressions in apoptosis markers in the kaempferol treated group mice tissues compared to the control group mice. In addition, our in vitro and in vivo data showed kaempferol can also inhibit bladder cancer invasion and metastasis. Further mechanism dissection studies showed that significant down-regulation of the c-Met/p38 signaling pathway is responsible for the kaempferol mediated cell proliferation inhibition. All these findings suggest kaempferol might be an effective and novel chemotherapeutic drug to apply for the future therapeutic agent to combat bladder cancer.

  14. Tumor suppressive role of sestrin2 during colitis and colon carcinogenesis

    PubMed Central

    Ro, Seung-Hyun; Xue, Xiang; Ramakrishnan, Sadeesh K; Cho, Chun-Seok; Namkoong, Sim; Jang, Insook; Semple, Ian A; Ho, Allison; Park, Hwan-Woo; Shah, Yatrik M; Lee, Jun Hee

    2016-01-01

    The mTOR complex 1 (mTORC1) and endoplasmic reticulum (ER) stress pathways are critical regulators of intestinal inflammation and colon cancer growth. Sestrins are stress-inducible proteins, which suppress both mTORC1 and ER stress; however, the role of Sestrins in colon physiology and tumorigenesis has been elusive due to the lack of studies in human tissues or in appropriate animal models. In this study, we show that human SESN2 expression is elevated in the colon of ulcerative colitis patients but is lost upon p53 inactivation during colon carcinogenesis. In mouse colon, Sestrin2 was critical for limiting ER stress and promoting the recovery of epithelial cells after inflammatory injury. During colitis-promoted tumorigenesis, Sestrin2 was shown to be an important mediator of p53’s control over mTORC1 signaling and tumor cell growth. These results highlight Sestrin2 as a novel tumor suppressor, whose downregulation can accelerate both colitis and colon carcinogenesis. DOI: http://dx.doi.org/10.7554/eLife.12204.001 PMID:26913956

  15. MiR-30a-5p suppresses tumor growth in colon carcinoma by targeting DTL.

    PubMed

    Baraniskin, Alexander; Birkenkamp-Demtroder, Karin; Maghnouj, Abdelouahid; Zöllner, Hannah; Munding, Johanna; Klein-Scory, Susanne; Reinacher-Schick, Anke; Schwarte-Waldhoff, Irmgard; Schmiegel, Wolff; Hahn, Stephan A

    2012-04-01

    MicroRNAs (miRNAs) are small non-coding RNAs that are involved in different biological processes by suppressing target gene expression. Altered expression of miR-30a-5p has been reported in colon carcinoma. To elucidate its potential biological role in colon cancer, miR-30a-5p was overexpressed via a lentiviral vector system in two different colon cancer cell lines. This induced in both lines miR-30a-5p-mediated growth inhibition, attributable to a cell cycle arrest at the G(1) phase and an induction of apoptosis. Combining global gene expression analyses of miR-30a-5p transgenic line HCT116 with in silico miRNA target prediction, we identified the denticleless protein homolog (DTL) as a potential miRNA-30a-5p target. Subsequent reporter gene assays confirmed the predicted miR-30a-5p binding site in the 3'untranslated region of DTL. Importantly, overexpression of DTL in HCT116 cells partially rescued these cells from miR-30a-5p-mediated growth suppression. In addition, TP53 and CDKN1A expression were increased in miR-30a-5p-overexpressing HCT116 cells, suggesting that miR-30a-5p is able to modulate the cell cycle via a DTL-TP53-CDKN1A regulatory circuit. Finally, 379 colorectal cancer tissues were screened for DTL expression and DTL was found to be overexpressed in 95.8% of human colorectal cancers compared with normal colon mucosa. In conclusion, our data identified miR-30a-5p as a tumor-suppressing miRNA in colon cancer cells exerting its function via modulation of DTL expression, which is frequently overexpressed in colorectal cancer. Thus, our data suggest that restoring miR-30a-5p function may prove useful as therapeutic strategy for tumors with reduced miR-30a-5p expression.

  16. Intratumoral injection of taxol in vivo suppresses A549 tumor showing cytoplasmic vacuolization.

    PubMed

    Wang, Chaoyang; Chen, Tongsheng

    2012-04-01

    Based on our recent in vitro studies, this report was designed to explore the mechanism by which high concentration of taxol (70 µM) induced paraptosis-like cell death in human lung carcinoma (A549) cells, and to evaluate the therapeutic efficacy of taxol using A549 tumor-bearing mice in vivo. Exposure of cells to taxol induced time-dependent cytotoxicity and cytoplasmic vacuolization without the involvement of Bax, Bak, Mcl-1, Bcl-XL, and caspase-3. Although taxol treatment induced activating transcription factor 6 (ATF6) cleavage indicative of endoplasmic reticulum (ER) stress, silencing ATF6 by shATF6 did not prevent taxol-induced both cytotoxcity and cytoplasmic vacuolization, suggesting that taxol-induced cytoplasmic vacuolization and cell death were not due to ER stress. Moreover, taxol-treated cells did not show DNA fragmentation and loss of mitochondrial membrane potential, the typical characteristics of apoptosis. In addition, taxol-induced cytoplasmic vacuolization did not show the cellular lysis, the characteristics of oncosis, and positive of β-galactosidase, the characteristic of senescence, indicating that taxol induced paraptosis-like cell death is neither oncosis nor senescence. Moreover, our in vivo data showed that intratumoral injection of taxol (50 mg/kg) in A549 tumor xenograft mice on day 1 and day 19 potently suppressed tumor growth showing significant ER vacuolization without toxicity. In conclusion, high concentration of taxol exhibits a significant anticancer activity by inducing paraptosis-like cell death in vitro and in vivo, without significant toxicity, suggesting a promising therapeutic strategy for apoptosis-resistance cancer by inducing ER vacuolization.

  17. APOBEC3G exerts tumor suppressive effects in human hepatocellular carcinoma.

    PubMed

    Chang, Li-Ching; Kuo, Ting-Yin; Liu, Ching-Wen; Chen, Yaw-Sen; Lin, Hsi-Hsun; Wu, Pei-Fung

    2014-04-01

    In this study, we collected 44 hepatitis B virus surface antigen positivity HBsAg (+) tumor and nontumor hepatocellular tissues from hepatocellular carcinoma (HCC) patients during hepatectomy, and quantified the APOBEC3G (A3G) mRNA by using a real-time PCR. Our results showed higher expression of A3G mRNA in the nontumor tissues than in the tumor tissues of the HBsAg (+) HCC patients. To further investigate this phenomenon, we constructed a pLV-A3G vector and transfected it into the human HCC cell line, Hep 3B. The results of an immunofluorescence analysis showed the overexpression of A3G in the cytoplasm. We then evaluated A3G cytotoxicity by using a cell viability assay (MTS assay), the results of which showed that Hep 3B cell viability was 88 and 58% after the transfection of pLV and pLV-A3G, respectively, indicating the growth inhibitory effects of A3G on Hep 3B cells. To further evaluate the tumor suppressive effects of A3G, we used a plastic pipette tip to scratch Hep 3B cells grown on a culture dish (to 70-80% confluence) after transfection with pLV-A3G. Our data indicated a ratio of wound closure of 100% in the control cells and in the pLV-expressing cells, compared with 43% in the pLV-A3G-overexpressing cells, 72 h after the wound scratch, as observed using phase-contrast microscopy. These results indicated that A3G inhibits wound healing in Hep 3B cells. Overall, our results suggest that A3G inhibits the growth of human hepatoma cells. PMID:24500029

  18. 5α-reductase inhibition suppresses testosterone-induced initial regrowth of regressed xenograft prostate tumors in animal models.

    PubMed

    Masoodi, Khalid Z; Ramos Garcia, Raquel; Pascal, Laura E; Wang, Yujuan; Ma, Hei M; O'Malley, Katherine; Eisermann, Kurtis; Shevrin, Daniel H; Nguyen, Holly M; Vessella, Robert L; Nelson, Joel B; Parikh, Rahul A; Wang, Zhou

    2013-07-01

    Androgen deprivation therapy (ADT) is the standard treatment for patients with prostate-specific antigen progression after treatment for localized prostate cancer. An alternative to continuous ADT is intermittent ADT (IADT), which allows recovery of testosterone during off-cycles to stimulate regrowth and differentiation of the regressed prostate tumor. IADT offers patients a reduction in side effects associated with ADT, improved quality of life, and reduced cost with no difference in overall survival. Our previous studies showed that IADT coupled with 5α-reductase inhibitor (5ARI), which blocks testosterone conversion to DHT could prolong survival of animals bearing androgen-sensitive prostate tumors when off-cycle duration was fixed. To further investigate this clinically relevant observation, we measured the time course of testosterone-induced regrowth of regressed LuCaP35 and LNCaP xenograft tumors in the presence or absence of a 5ARI. 5α-Reductase inhibitors suppressed the initial regrowth of regressed prostate tumors. However, tumors resumed growth and were no longer responsive to 5α-reductase inhibition several days after testosterone replacement. This finding was substantiated by bromodeoxyuridine and Ki67 staining of LuCaP35 tumors, which showed inhibition of prostate tumor cell proliferation by 5ARI on day 2, but not day 14, after testosterone replacement. 5α-Reductase inhibitors also suppressed testosterone-stimulated proliferation of LNCaP cells precultured in androgen-free media, suggesting that blocking testosterone conversion to DHT can inhibit prostate tumor cell proliferation via an intracrine mechanism. These results suggest that short off-cycle coupled with 5α-reductase inhibition could maximize suppression of prostate tumor growth and, thus, improve potential survival benefit achieved in combination with IADT. PMID:23671262

  19. Tumor-suppressive effects of natural-type interferon-β through CXCL10 in melanoma

    SciTech Connect

    Kobayashi, Hikaru; Nobeyama, Yoshimasa Nakagawa, Hidemi

    2015-08-21

    Introduction: Type 1 interferon is in widespread use as adjuvant therapy to inhibit melanoma progression. Considering the tumor-suppressive effects of local administration of interferon-β (IFN-β) on lymphatic metastasis, the present study was conducted to identify melanoma-suppressive molecules that are up-regulated by IFN-β treatment of lymphatic endothelial cells. Materials and methods: Lymphatic endothelial cells, fibroblasts, and melanoma cells were treated with natural-type IFN-β, and melanoma cells were treated with CXCL10. Genome-wide oligonucleotide microarray analysis was performed using lymphatic endothelial cells with or without IFN-β treatment. Quantitative real-time reverse transcription-PCR and an enzyme-linked immunosorbent assay were performed to examine CXCL10 expression. A proliferation assay was performed to examine the effects of IFN-β and CXCL10 in melanoma cells. Results: Genome-wide microarray analyses detected CXCL10 as a gene encoding a secretory protein that was up-regulated by IFN-β in lymphatic endothelial cells. IFN-β treatment significantly induced CXCL10 in dermal lymphatic endothelial cells and melanoma cells that are highly sensitive to IFN-β. CXCL10 reduced melanoma cell proliferation in IFN-β-sensitive cells as well as resistant cells. Melanoma cells in which CXCL10 was knocked down were sensitive to IFN-β. CXCR3-B, which encodes the CXCL10 receptor, was up-regulated in melanoma cells with high sensitivity to IFN-β and down-regulated in melanoma cells with medium to low sensitivity. Conclusions: Our data suggest that IFN-β suppresses proliferation and metastasis from the local lymphatic system and melanoma cells via CXCL10. Down-regulation of CXCR3-B by IFN-β may be associated with resistance to IFN-β. - Highlights: • We search melanoma-suppressive molecules induced by IFN-β. • IFN-β induces a high amount of CXCL10 from lymphatic endothelial cells. • CXCL10 induction level in melanoma cells is correlated

  20. hnRNP G elicits tumor-suppressive activity in part by upregulating the expression of Txnip

    SciTech Connect

    Shin, Ki-Hyuk Kim, Reuben H.; Kim, Roy H.; Kang, Mo K.; Park, No-Hee

    2008-08-08

    Heterogeneous nuclear ribonuclearproteins (hnRNPs) are nucleic acid-binding proteins and have critical roles in DNA repair, telomere regulation, and transcriptional gene regulation. Previously, we showed that hnRNP G has tumor-suppressive activity in human oral squamous cell carcinoma cells. Therefore, the identification of hnRNP G target genes is important for understanding the function of hnRNP G and its tumor-suppressive activity. In this study, we identify a known tumor suppressor gene, thioredoxin-interacting protein (Txnip) gene as a novel target of hnRNP G. Expression of Txnip is upregulated by wild-type (wt) hnRNP G but not by a suppression-defective mutant hnRNP G (K22R) in human squamous cell carcinoma. Wt hnRNP G binds and transactivates the Txnip promoter in vivo, whereas the K22R mutant does not. Furthermore, overexpression of Txnip alone in cancer cells leads to the inhibition of anchorage-independent growth and in vivo tumorigenicity in immunocompromised mice, suggesting a reversion of the transformation phenotype. These studies indicate that hnRNP G promotes the expression of Txnip and mediates its tumor-suppressive effect.

  1. The B-cell tumor promoter Bcl-3 suppresses inflammation-associated colon tumorigenesis in epithelial cells

    PubMed Central

    Tang, Wanhu; Wang, Hongshan; Ha, Hye-lin; Tassi, Ilaria; Bhardwaj, Reetika; Claudio, Estefania; Siebenlist, Ulrich

    2016-01-01

    Bcl-3 is an atypical member of the IκB family. It associates with p50/NF-κB1 and p52/NF-κB2 homodimers in nuclei where it modulates transcription in a context-dependent manner. A subset of B cell tumors exhibits recurrent translocations of Bcl-3, resulting in overexpression. Elevated expression without translocations is also observed in various B cell lymphomas and even some solid tumors. Here we investigated the role of Bcl-3 in AOM/DSS-induced colon tumors, a mouse model for colitis-associated colorectal cancers in humans. Contrary to expectations, Bcl-3 suppressed colorectal tumor formation: Bcl-3-deficient mice were relatively protected from DSS-induced epithelial damage and developed more polyps after AOM/DSS treatment, though polyp size was unaffected. DSS-challenged mutant mice exhibited increased recruitment of myeloid-derived suppressor cells (MDSCs), consistent with protection of the epithelium. Loss of Bcl-3 in intestinal epithelial cells was sufficient to increase tumorigenesis. The added tumor burden in mutant mice was dependent on TNFα, a tumorigenic, NF-κB-mediated signaling pathway that was dampened by Bcl-3. These findings reveal a tumor-suppressive role for Bcl-3 in this inflammation-associated cancer model. Bcl-3 thus functions as a tumor promoter or suppressor, depending on the cellular and environmental context. PMID:27132515

  2. Proton irradiation suppresses angiogenic genes and impairs cell invasion and tumor growth.

    PubMed

    Girdhani, Swati; Lamont, Clare; Hahnfeldt, Philip; Abdollahi, Amir; Hlatky, Lynn

    2012-07-01

    The energy deposition characteristics of proton radiation have attracted considerable attention in light of its implications for carcinogenesis risk in space travel, as well for application to cancer treatment. In space, it is the principle component of the galactic cosmic radiation to which astronauts will be exposed. For treatment, an increasing number of proton facilities are being established to exploit the physical advantages of this radiation type. However, the possibility that there may also be biologically based advantages to proton exposure has not been considered in either context. We demonstrate here that high-energy proton irradiation can inhibit expression of major pro-angiogenic factors and multiple angiogenesis-associated processes, including invasion and endothelial cell proliferation, which is prominent in cancer progression. Dose-dependent suppression of angiogenic signaling was demonstrated for both cancer and nontransformed cells. Pan-genomic microarray analysis and RT-PCR revealed that post-irradiation (0.5, 1.0 and 2.0 Gy), critical pro-angiogenic signaling factors including: vascular endothelial growth factor (VEGF), interleukin 6 and 8 (IL-6, IL-8) and hypoxia-inducible factor-1 alpha (HIF-1A), were significantly downregulated. Co-culture studies demonstrated that endothelial cell proliferation and invasion were inhibited by culturing with irradiated cancer or fibroblast cells, which suggests that proton irradiation may, in addition to direct action, contribute to angiogenesis suppression through modulation of paracrine signalings from targeted cells. Addition of recombinant IL-8 or VEGF partially restored these functions in vitro, while in vivo, an attenuated tumor growth rate was demonstrated for proton-irradiated human lung cancer cells. Taken together, these findings provide novel pre-clinical evidence that proton irradiation may, in addition to its physical targeting advantages, have important biological ramifications that should be a

  3. Proton irradiation suppresses angiogenic genes and impairs cell invasion and tumor growth.

    PubMed

    Girdhani, Swati; Lamont, Clare; Hahnfeldt, Philip; Abdollahi, Amir; Hlatky, Lynn

    2012-07-01

    The energy deposition characteristics of proton radiation have attracted considerable attention in light of its implications for carcinogenesis risk in space travel, as well for application to cancer treatment. In space, it is the principle component of the galactic cosmic radiation to which astronauts will be exposed. For treatment, an increasing number of proton facilities are being established to exploit the physical advantages of this radiation type. However, the possibility that there may also be biologically based advantages to proton exposure has not been considered in either context. We demonstrate here that high-energy proton irradiation can inhibit expression of major pro-angiogenic factors and multiple angiogenesis-associated processes, including invasion and endothelial cell proliferation, which is prominent in cancer progression. Dose-dependent suppression of angiogenic signaling was demonstrated for both cancer and nontransformed cells. Pan-genomic microarray analysis and RT-PCR revealed that post-irradiation (0.5, 1.0 and 2.0 Gy), critical pro-angiogenic signaling factors including: vascular endothelial growth factor (VEGF), interleukin 6 and 8 (IL-6, IL-8) and hypoxia-inducible factor-1 alpha (HIF-1A), were significantly downregulated. Co-culture studies demonstrated that endothelial cell proliferation and invasion were inhibited by culturing with irradiated cancer or fibroblast cells, which suggests that proton irradiation may, in addition to direct action, contribute to angiogenesis suppression through modulation of paracrine signalings from targeted cells. Addition of recombinant IL-8 or VEGF partially restored these functions in vitro, while in vivo, an attenuated tumor growth rate was demonstrated for proton-irradiated human lung cancer cells. Taken together, these findings provide novel pre-clinical evidence that proton irradiation may, in addition to its physical targeting advantages, have important biological ramifications that should be a

  4. Cadmium-coordinated supramolecule suppresses tumor growth of T-cell leukemia in mice.

    PubMed

    Zhou, Xiaoping; Koizumi, Yukio; Zhang, Muxin; Natsui, Miyuki; Koyota, Souichi; Yamada, Manabu; Kondo, Yoshihiko; Hamada, Fumio; Sugiyama, Toshihiro

    2015-05-01

    Cadmium is a toxic pollutant with occupational and environmental significance, due to its diverse toxic effects. Supramolecules that conjugate and decontaminate toxic metals have potential for use in treatment of cadmium intoxication. In addition, metal-coordinating ability has been postulated to contribute to the cytotoxic effects of anti-tumor agents such as cisplatin or bleomycin. Thiacalixarenes, cyclic oligomers of p-alkylphenol bridged by sulfur atoms, are supramolecules known to have potent coordinating ability to metal ions. In this study, we show that cadmium-coordinated thiacalix[4]arene tetrasulfate (TC4ATS-Cd) exhibits an anti-proliferative effect against T-cell leukemia cells. Cadmium exhibited cytotoxicity with IC50 values ranging from 36 to 129 μM against epithelia-derived cancer cell lines, while TC4ATS-Cd elicited no significant cytotoxicity (IC50 > 947 μM). However, a number of T-cell leukemia cell lines exhibited marked sensitivity to TC4ATS-Cd. In Jurkat cells, toxicity of TC4ATS-Cd occurred with an IC50 of 6.9 μM, which is comparable to that of 6.5 μM observed for cadmium alone. TC4ATS-Cd induced apoptotic cell death through activation of caspase-3 in Jurkat cells. In a xenograft model, TC4ATS-Cd (13 mg/kg) treatment significantly suppressed the tumor growth of Jurkat cells in mice. In addition, TC4ATS-Cd-treated mice exhibited significantly less cadmium accumulation in liver and kidney compared to equimolar cadmium-treated mice. These results suggest that cadmium-coordinated supramolecules may have therapeutic potential for treatment of T-cell leukemia.

  5. Cadmium-coordinated supramolecule suppresses tumor growth of T-cell leukemia in mice

    PubMed Central

    Zhou, Xiaoping; Koizumi, Yukio; Zhang, Muxin; Natsui, Miyuki; Koyota, Souichi; Yamada, Manabu; Kondo, Yoshihiko; Hamada, Fumio; Sugiyama, Toshihiro

    2015-01-01

    Cadmium is a toxic pollutant with occupational and environmental significance, due to its diverse toxic effects. Supramolecules that conjugate and decontaminate toxic metals have potential for use in treatment of cadmium intoxication. In addition, metal-coordinating ability has been postulated to contribute to the cytotoxic effects of anti-tumor agents such as cisplatin or bleomycin. Thiacalixarenes, cyclic oligomers of p-alkylphenol bridged by sulfur atoms, are supramolecules known to have potent coordinating ability to metal ions. In this study, we show that cadmium-coordinated thiacalix[4]arene tetrasulfate (TC4ATS-Cd) exhibits an anti-proliferative effect against T-cell leukemia cells. Cadmium exhibited cytotoxicity with IC50 values ranging from 36 to 129 μM against epithelia-derived cancer cell lines, while TC4ATS-Cd elicited no significant cytotoxicity (IC50 > 947 μM). However, a number of T-cell leukemia cell lines exhibited marked sensitivity to TC4ATS-Cd. In Jurkat cells, toxicity of TC4ATS-Cd occurred with an IC50 of 6.9 μM, which is comparable to that of 6.5 μM observed for cadmium alone. TC4ATS-Cd induced apoptotic cell death through activation of caspase-3 in Jurkat cells. In a xenograft model, TC4ATS-Cd (13 mg/kg) treatment significantly suppressed the tumor growth of Jurkat cells in mice. In addition, TC4ATS-Cd-treated mice exhibited significantly less cadmium accumulation in liver and kidney compared to equimolar cadmium-treated mice. These results suggest that cadmium-coordinated supramolecules may have therapeutic potential for treatment of T-cell leukemia. PMID:25735932

  6. The Tumor-Suppressive and Potential Therapeutic Functions of miR-34a in Epithelial Carcinomas

    PubMed Central

    Adams, Brian D.; Parsons, Christine; Slack, Frank J.

    2016-01-01

    Introduction Many RNA species have been identified as important players in the development of chronic diseases including cancer. Certain classes of regulatory RNAs such as miRNAs have been investigated in such detail that bona fide tumor suppressive and oncogenic miRNAs have been identified. Because of this, there has been a major effort to therapeutically target these small RNAs. One in particular, a liposomal formulation of miR-34a (MRX34), has entered Phase I trials. Areas Covered This review aims to summarize miRNA biology, its regulation within normal versus disease states, and how it can be targeted therapeutically, with a particular emphasis on miR-34a. Understanding the complexity of a single miRNA will aid in the development of future RNA-based therapeutics for a broader range of chronic diseases. Expert Opinion The potential of miRNAs to be developed into anti-cancer therapeutics has become an increasingly important area of research. miR-34a is a tumor suppressive miRNA across many tumor types through its ability to inhibit cellular proliferation, invasion, and tumor sphere formation. miR-34a also shows promise within certain in vivo solid tumor models. Finally, as miR-34a moves into clinical trials it will be important to determine if it can further sensitize tumors to certain chemotherapeutic agents. PMID:26652031

  7. Systemic immune suppression in glioblastoma: the interplay between CD14+HLA-DRlo/neg monocytes, tumor factors, and dexamethasone

    PubMed Central

    Gustafson, Michael P.; Lin, Yi; New, Kent C.; Bulur, Peggy A.; O'Neill, Brian Patrick; Gastineau, Dennis A.; Dietz, Allan B.

    2010-01-01

    Patients with glioblastoma (GBM) exhibit profound systemic immune defects that affect the success of conventional and immune-based treatments. A better understanding of the contribution of the tumor and/or therapy on systemic immune suppression is necessary for improved therapies, to monitor negative effects of novel treatments, to improve patient outcomes, and to increase understanding of this complex system. To characterize the immune profile of GBM patients, we phenotyped peripheral blood and compared these to normal donors. In doing so, we identified changes in systemic immunity associated with both the tumor and dexamethasone treated tumor bearing patients. In particular, dexamethasone exacerbated tumor associated lymphopenia primarily in the T cell compartment. We have also identified unique tumor and dexamethasone dependent altered monocyte phenotypes. The major population of altered monocytes (CD14+HLA-DRlo/neg) had a phenotype distinct from classical myeloid suppressor cells. These cells inhibited T cell proliferation, were unable to fully differentiate into mature dendritic cells, were associated with dexamethasone-mediated changes in CCL2 levels, and could be re-created in vitro using tumor supernatants. We provide evidence that tumors express high levels of CCL2, can contain high numbers of CD14+ cells, that tumor supernatants can transform CD14+HLA-DR+ cells into CD14+HLA-DRlo/neg immune suppressors, and that dexamethasone reduces CCL2 in vitro and is correlated with reduction of CCL2 in vivo. Consequently, we have developed a model for tumor mediated systemic immune suppression via recruitment and transformation of CD14+ cells. PMID:20179016

  8. Thyroid-Stimulating Hormone Suppression for Protection Against Hypothyroidism Due to Craniospinal Irradiation for Childhood Medulloblastoma/Primitive Neuroectodermal Tumor

    SciTech Connect

    Massimino, Maura Gandola, Lorenza; Collini, Paola; Seregni, Ettore; Marchiano, Alfonso; Serra, Annalisa; Pignoli, Emanuele Ph.D.; Spreafico, Filippo; Pallotti, Federica; Terenziani, Monica; Biassoni, Veronica; Bombardieri, Emilio; Fossati-Bellani, Franca

    2007-10-01

    Purpose: Hypothyroidism is one of the earliest endocrine effects of craniospinal irradiation (CSI). The effects of radiation also depend on circulating thyroid-stimulating hormone (TSH), which acts as an indicator of thyrocyte function and is the most sensitive marker of thyroid damage. Hence, our study was launched in 1998 to evaluate the protective effect of TSH suppression during CSI for medulloblastoma/primitive neuroectodermal tumor. Patients and Methods: From Jan 1998 to Feb 2001, a total of 37 euthyroid children scheduled for CSI for medulloblastoma/primitive neuroectodermal tumor underwent thyroid ultrasound and free triiodothyronine (FT3), free thyroxine (FT4), and TSH evaluation at the beginning and end of CSI. From 14 days before and up to the end of CSI, patients were administered L-thyroxine at suppressive doses; every 3 days, TSH suppression was checked to ensure a value <0.3 {mu}M/ml. During follow-up, blood tests and ultrasound were repeated after 1 year; primary hypothyroidism was considered an increased TSH level greater than normal range. CSI was done using a hyperfractionated accelerated technique with total doses ranging from 20.8-39 Gy; models were used to evaluate doses received by the thyroid bed. Results: Of 37 patients, 25 were alive a median 7 years after CSI. They were well matched for all clinical features, except that eight children underwent adequate TSH suppression during CSI, whereas 17 did not. Hypothyroidism-free survival rates were 70% for the 'adequately TSH-suppressed' group and 20% for the 'inadequately TSH-suppressed' group (p = 0.02). Conclusions: Thyroid-stimulating hormone suppression with L-thyroxine had a protective effect on thyroid function at long-term follow-up. This is the first demonstration that transient endocrine suppression of thyroid activity may protect against radiation-induced functional damage.

  9. Adjuvant Cationic Liposomes Presenting MPL and IL-12 Induce Cell Death, Suppress Tumor Growth, and Alter the Cellular Phenotype of Tumors in a Murine Model of Breast Cancer

    PubMed Central

    2015-01-01

    Dendritic cells (DC) process and present antigens to T lymphocytes, inducing potent immune responses when encountered in association with activating signals, such as pathogen-associated molecular patterns. Using the 4T1 murine model of breast cancer, cationic liposomes containing monophosphoryl lipid A (MPL) and interleukin (IL)-12 were administered by intratumoral injection. Combination multivalent presentation of the Toll-like receptor-4 ligand MPL and cytotoxic 1,2-dioleoyl-3-trmethylammonium-propane lipids induced cell death, decreased cellular proliferation, and increased serum levels of IL-1β and tumor necrosis factor (TNF)-α. The addition of recombinant IL-12 further suppressed tumor growth and increased expression of IL-1β, TNF-α, and interferon-γ. IL-12 also increased the percentage of cytolytic T cells, DC, and F4/80+ macrophages in the tumor. While single agent therapy elevated levels of nitric oxide synthase 3-fold above basal levels in the tumor, combination therapy with MPL cationic liposomes and IL-12 stimulated a 7-fold increase, supporting the observed cell cycle arrest (loss of Ki-67 expression) and apoptosis (TUNEL positive). In mice bearing dual tumors, the growth of distal, untreated tumors mirrored that of liposome-treated tumors, supporting the presence of a systemic immune response. PMID:25179345

  10. Regulatory T-cell Trafficking: From Thymic Development to Tumor-Induced Immune Suppression

    PubMed Central

    Mailloux, Adam W.; Young, M. Rita I.

    2011-01-01

    Regulatory T cells (Tregs) have become a priority for many investigators in immunology due to their potent immunosuppressive and tolerogenic effects. While Treg activity is required for normal immune homeostasis, dysregulation of their numbers can induce autoimmunity or aid in the pathogenesis of disease. Therefore, great effort has been made to understand the mechanisms by which Tregs accumulate in different areas of the body. Like other lymphocytes, Tregs migrate in response to a network of chemotactic stimuli involving chemokines, chemokine receptors, integrins, and their corresponding ligands. However, many of these stimuli are exclusive to Tregs, inducing their migration while leaving conventional populations unaffected. It is these selective stimuli that result in increased ratios of Tregs among conventional effector populations, leading to changes in immune suppression and homeostasis. This review explores selective Treg trafficking during thymic Treg development, migration to secondary lymphoid tissues and emigration into the periphery during homeostatic conditions, inflammation, and the tumor microenvironment, placing emphasis on stimuli that selectively recruits Tregs to target locations. PMID:21083525

  11. Downregulation and tumor-suppressive role of XPO5 in hepatocellular carcinoma.

    PubMed

    Li, Yandong; Wang, Xiao; He, Bin; Cai, Hui; Gao, Yong

    2016-04-01

    XPO5 (Exp5, Exportin-5) is a transporter protein mainly mediating pre-microRNAs' nuclear export. Recent studies have demonstrated that XPO5 may play crucial roles in a few of cancers. However, little is known about XPO5 in hepatocellular carcinoma (HCC). In the present study, we elucidated the expression of XPO5 by quantitative real-time PCR (qRT-PCR) and immunohistochemical staining in HCC samples and conducted several functional analyses to address its effects on HCC development. The results demonstrated that both mRNA and protein levels of XPO5 were downregulated in HCC tissues compared to adjacent non-cancerous livers. Ectopic expression of XPO5 significantly suppressed cell proliferation, colony formation, growth in soft agar, and tumorigenicity in nude mice, whereas knockdown of XPO5 by RNA inference showed opposite phenotypes. Moreover, XPO5 knockdown promoted HCC cell migration and decreased the expression of E-cadherin and p53. Additionally, after treatment with DAC and TSA, the mRNA level of XPO5 was upregulated in HCC cells tested, implicating that epigenetic modulation may be involved in the transcription of XPO5. Collectively, our findings suggest that XPO5 functions as a potential tumor suppressor in the development and progression of HCC as well as a promising molecular target for HCC therapy. PMID:27000860

  12. Myristica fragrans Suppresses Tumor Growth and Metabolism by Inhibiting Lactate Dehydrogenase A.

    PubMed

    Kim, Eun-Yeong; Choi, Hee-Jung; Park, Mi-Ju; Jung, Yeon-Seop; Lee, Syng-Ook; Kim, Keuk-Jun; Choi, Jung-Hye; Chung, Tae-Wook; Ha, Ki-Tae

    2016-01-01

    Most cancer cells predominantly produce ATP by maintaining a high rate of lactate fermentation, rather than by maintaining a comparatively low rate of tricarboxylic acid cycle, i.e., Warburg's effect. In the pathway, the pyruvate produced by glycolysis is converted to lactic acid by lactate dehydrogenase (LDH). Here, we demonstrated that water extracts from the seeds of Myristica fragrans Houtt. (MF) inhibit the in vitro enzymatic activity of LDH. MF effectively suppressed cell growth and the overall Warburg effect in HT29 human colon cancer cells. Although the expression of LDH-A was not changed by MF, both lactate production and LDH activity were decreased in MF-treated cells under both normoxic and hypoxic conditions. In addition, intracellular ATP levels were also decreased by MF treatment, and the uptake of glucose was also reduced by MF treatment. Furthermore, the experiment on tumor growth in the in vivo mice model revealed that MF effectively reduced the growth of allotransplanted Lewis lung carcinoma cells. Taken together, these results suggest that MF effectively inhibits cancer growth and metabolism by inhibiting the activity of LDH, a major enzyme responsible for regulating cancer metabolism. These results implicate MF as a potential candidate for development into a novel drug against cancer through inhibition of LDH activity.

  13. Integrated digital error suppression for improved detection of circulating tumor DNA

    PubMed Central

    Kurtz, David M.; Chabon, Jacob J.; Scherer, Florian; Stehr, Henning; Liu, Chih Long; Bratman, Scott V.; Say, Carmen; Zhou, Li; Carter, Justin N.; West, Robert B.; Sledge, George W.; Shrager, Joseph B.; Loo, Billy W.; Neal, Joel W.; Wakelee, Heather A.; Diehn, Maximilian; Alizadeh, Ash A.

    2016-01-01

    High-throughput sequencing of circulating tumor DNA (ctDNA) promises to facilitate personalized cancer therapy. However, low quantities of cell-free DNA (cfDNA) in the blood and sequencing artifacts currently limit analytical sensitivity. To overcome these limitations, we introduce an approach for integrated digital error suppression (iDES). Our method combines in silico elimination of highly stereotypical background artifacts with a molecular barcoding strategy for the efficient recovery of cfDNA molecules. Individually, these two methods each improve the sensitivity of cancer personalized profiling by deep sequencing (CAPP-Seq) by ~3 fold, and synergize when combined to yield ~15-fold improvements. As a result, iDES-enhanced CAPP-Seq facilitates noninvasive variant detection across hundreds of kilobases. Applied to clinical non-small cell lung cancer (NSCLC) samples, our method enabled biopsy-free profiling of EGFR kinase domain mutations with 92% sensitivity and 96% specificity and detection of ctDNA down to 4 in 105 cfDNA molecules. We anticipate that iDES will aid the noninvasive genotyping and detection of ctDNA in research and clinical settings. PMID:27018799

  14. Decreased Warburg effect induced by ATP citrate lyase suppression inhibits tumor growth in pancreatic cancer.

    PubMed

    Zong, Haifeng; Zhang, Yang; You, Yong; Cai, Tiantian; Wang, Yehuang

    2015-03-01

    ATP citrate lyase (ACLY) is responsible for the conversion of cytosolic citrate into acetyl-CoA and oxaloacetate, and the first rate-limiting enzyme involved in de novo lipogenesis. Recent studies have demonstrated that inhibition of elevated ACLY results in growth arrest and apoptosis in a subset of cancers; however, the expression pattern and underlying biological function of ACLY in pancreatic ductal adenocarcinoma (PDAC) remains unclear. In the current study, overexpressed ACLY was more commonly observed in PDAC compared to normal pancreatic tissues. Kaplan-Meier survival analysis showed that high expression level of ACLY resulted in a poor prognosis of PDAC patients. Silencing of endogenous ACLY expression by siRNA in PANC-1 cells led to reduced cell viability and increased cell apoptosis. Furthermore, significant decrease in glucose uptake and lactate production was observed after ACLY was knocked down, and this effect was blocked by 2-deoxy-D-glucose, indicating that ACLY functions in the Warburg effect affect PDAC cell growth. Collectively, this study reveals that suppression of ACLY plays an anti-tumor role through decreased Warburg effect, and ACLY-related inhibitors might be potential therapeutic approaches for PDAC. PMID:25701462

  15. Volasertib suppresses tumor growth and potentiates the activity of cisplatin in cervical cancer

    PubMed Central

    Xie, Feng-Feng; Pan, Shi-Shi; Ou, Rong-Ying; Zheng, Zhen-Zhen; Huang, Xiao-Xiu; Jian, Meng-Ting; Qiu, Jian-Ge; Zhang, Wen-Ji; Jiang, Qi-Wei; Yang, Yang; Li, Wen-Feng; Shi, Zhi; Yan, Xiao-Jian

    2015-01-01

    Volasertib (BI 6727), a highly selective and potent inhibitor of PLK1, has shown broad antitumor activities in the preclinical and clinical studies for the treatment of several types of cancers. However, the anticancer effect of volasertib on cervical cancer cells is still unknown. In the present study, we show that volasertib can markedly induce cell growth inhibition, cell cycle arrest at G2/M phase and apoptosis with the decreased protein expressions of PLK1 substrates survivin and wee1 in human cervical cancer cells. Furthermore, volasertib also enhances the intracellular reactive oxidative species (ROS) levels, and pretreated with ROS scavenger N-acety-L-cysteine totally blocks ROS generation but partly reverses volasertib-induced apoptosis. In addition, volasertib significantly potentiates the activity of cisplatin to inhibit the growth of cervical cancer in vitro and in vivo. In brief, volasertib suppresses tumor growth and potentiates the activity of cisplatin in cervical cancer, suggesting the combination of volasertib and cisplatin may be a promising strategy for the treatment of patients with cervical cancer. PMID:26885445

  16. Volasertib suppresses tumor growth and potentiates the activity of cisplatin in cervical cancer.

    PubMed

    Xie, Feng-Feng; Pan, Shi-Shi; Ou, Rong-Ying; Zheng, Zhen-Zhen; Huang, Xiao-Xiu; Jian, Meng-Ting; Qiu, Jian-Ge; Zhang, Wen-Ji; Jiang, Qi-Wei; Yang, Yang; Li, Wen-Feng; Shi, Zhi; Yan, Xiao-Jian

    2015-01-01

    Volasertib (BI 6727), a highly selective and potent inhibitor of PLK1, has shown broad antitumor activities in the preclinical and clinical studies for the treatment of several types of cancers. However, the anticancer effect of volasertib on cervical cancer cells is still unknown. In the present study, we show that volasertib can markedly induce cell growth inhibition, cell cycle arrest at G2/M phase and apoptosis with the decreased protein expressions of PLK1 substrates survivin and wee1 in human cervical cancer cells. Furthermore, volasertib also enhances the intracellular reactive oxidative species (ROS) levels, and pretreated with ROS scavenger N-acety-L-cysteine totally blocks ROS generation but partly reverses volasertib-induced apoptosis. In addition, volasertib significantly potentiates the activity of cisplatin to inhibit the growth of cervical cancer in vitro and in vivo. In brief, volasertib suppresses tumor growth and potentiates the activity of cisplatin in cervical cancer, suggesting the combination of volasertib and cisplatin may be a promising strategy for the treatment of patients with cervical cancer. PMID:26885445

  17. Differentiation-inducing factor-1 suppresses gene expression of cyclin D1 in tumor cells

    SciTech Connect

    Yasmin, Tania; Takahashi-Yanaga, Fumi . E-mail: yanaga@clipharm.med.kyushu-u.ac.jp; Mori, Jun; Miwa, Yoshikazu; Hirata, Masato; Watanabe, Yutaka; Morimoto, Sachio; Sasaguri, Toshiyuki

    2005-12-16

    To determine the mechanism by which differentiation-inducing factor-1 (DIF-1), a morphogen of Dictyostelium discoideum, inhibits tumor cell proliferation, we examined the effect of DIF-1 on the gene expression of cyclin D1. DIF-1 strongly reduced the expression of cyclin D1 mRNA and correspondingly decreased the amount of {beta}-catenin in HeLa cells and squamous cell carcinoma cells. DIF-1 activated glycogen synthase kinase-3{beta} (GSK-3{beta}) and inhibition of GSK-3{beta} attenuated the DIF-1-induced {beta}-catenin degradation, indicating the involvement of GSK-3{beta} in this effect. Moreover, DIF-1 reduced the activities of T-cell factor (TCF)/lymphoid enhancer factor (LEF) reporter plasmid and a reporter gene driven by the human cyclin D1 promoter. Eliminating the TCF/LEF consensus site from the cyclin D1 promoter diminished the effect of DIF-1. These results suggest that DIF-1 inhibits Wnt/{beta}-catenin signaling, resulting in the suppression of cyclin D1 promoter activity.

  18. Bub1 kinase activity drives error correction and mitotic checkpoint control but not tumor suppression

    PubMed Central

    Ricke, Robin M.; Jeganathan, Karthik B.; Malureanu, Liviu; Harrison, Andrew M.

    2012-01-01

    The mitotic checkpoint protein Bub1 is essential for embryogenesis and survival of proliferating cells, and bidirectional deviations from its normal level of expression cause chromosome missegregation, aneuploidy, and cancer predisposition in mice. To provide insight into the physiological significance of this critical mitotic regulator at a modular level, we generated Bub1 mutant mice that lack kinase activity using a knockin gene-targeting approach that preserves normal protein abundance. In this paper, we uncover that Bub1 kinase activity integrates attachment error correction and mitotic checkpoint signaling by controlling the localization and activity of Aurora B kinase through phosphorylation of histone H2A at threonine 121. Strikingly, despite substantial chromosome segregation errors and aneuploidization, mice deficient for Bub1 kinase activity do not exhibit increased susceptibility to spontaneous or carcinogen-induced tumorigenesis. These findings provide a unique example of a modular mitotic activity orchestrating two distinct networks that safeguard against whole chromosome instability and reveal the differential importance of distinct aneuploidy-causing Bub1 defects in tumor suppression. PMID:23209306

  19. Chitosan/TPP Nanoparticles as a Gene Delivery Agent For Tumor Suppressant P53

    NASA Astrophysics Data System (ADS)

    Liu, Gaojun

    In the last decade, non-viral polymeric vectors have become more attractive than their viral counterparts due to their nontoxicity and good biocompatibility. However, one of the major drawbacks is the low transfection efficiency when compared to viruses. In this work, a naturally cationic polysaccharide, chitosan, was cross-linked with negatively charged tripolyphosphate (TPP) to synthesize chitosan/TPP nanoparticles (CNPs) for delivery of plasmid DNA (pDNA). Particle size and zeta potential were characterized for CNPs with chitosan-TPP mass ratios of 4:1 and 6:1 (w/w) using benchtop dynamic light scattering. And both potentiometric titration method and FTIR spectrometer were applied to measure the degree of deacetylation of chitosan. Release kinetics of a model protein (bovine serum albumin, BSA) showed a steady release that reached 7% after 6 days. Besides that, we also assessed the in vitro transfection efficiency of the CNP-pDNA system using fluorescence microscopy, as well as the effect of tumor suppressant p53. Later the release kinetics and encapsulation efficiency of plasmid DNA bound to the CNPs will be investigated. Additionally, we will try to improve the gene transfection efficiency in both MC3T3-E1 and osteosarcoma cells by applying Sonicator 740 therapeutic ultrasound. Key words: gene therapy, non-viral gene vector, chitosan/TPP nanoparticles, ionic gelation, p53.

  20. Myristica fragrans Suppresses Tumor Growth and Metabolism by Inhibiting Lactate Dehydrogenase A.

    PubMed

    Kim, Eun-Yeong; Choi, Hee-Jung; Park, Mi-Ju; Jung, Yeon-Seop; Lee, Syng-Ook; Kim, Keuk-Jun; Choi, Jung-Hye; Chung, Tae-Wook; Ha, Ki-Tae

    2016-01-01

    Most cancer cells predominantly produce ATP by maintaining a high rate of lactate fermentation, rather than by maintaining a comparatively low rate of tricarboxylic acid cycle, i.e., Warburg's effect. In the pathway, the pyruvate produced by glycolysis is converted to lactic acid by lactate dehydrogenase (LDH). Here, we demonstrated that water extracts from the seeds of Myristica fragrans Houtt. (MF) inhibit the in vitro enzymatic activity of LDH. MF effectively suppressed cell growth and the overall Warburg effect in HT29 human colon cancer cells. Although the expression of LDH-A was not changed by MF, both lactate production and LDH activity were decreased in MF-treated cells under both normoxic and hypoxic conditions. In addition, intracellular ATP levels were also decreased by MF treatment, and the uptake of glucose was also reduced by MF treatment. Furthermore, the experiment on tumor growth in the in vivo mice model revealed that MF effectively reduced the growth of allotransplanted Lewis lung carcinoma cells. Taken together, these results suggest that MF effectively inhibits cancer growth and metabolism by inhibiting the activity of LDH, a major enzyme responsible for regulating cancer metabolism. These results implicate MF as a potential candidate for development into a novel drug against cancer through inhibition of LDH activity. PMID:27430914

  1. Integrated digital error suppression for improved detection of circulating tumor DNA.

    PubMed

    Newman, Aaron M; Lovejoy, Alexander F; Klass, Daniel M; Kurtz, David M; Chabon, Jacob J; Scherer, Florian; Stehr, Henning; Liu, Chih Long; Bratman, Scott V; Say, Carmen; Zhou, Li; Carter, Justin N; West, Robert B; Sledge, George W; Shrager, Joseph B; Loo, Billy W; Neal, Joel W; Wakelee, Heather A; Diehn, Maximilian; Alizadeh, Ash A

    2016-05-01

    High-throughput sequencing of circulating tumor DNA (ctDNA) promises to facilitate personalized cancer therapy. However, low quantities of cell-free DNA (cfDNA) in the blood and sequencing artifacts currently limit analytical sensitivity. To overcome these limitations, we introduce an approach for integrated digital error suppression (iDES). Our method combines in silico elimination of highly stereotypical background artifacts with a molecular barcoding strategy for the efficient recovery of cfDNA molecules. Individually, these two methods each improve the sensitivity of cancer personalized profiling by deep sequencing (CAPP-Seq) by about threefold, and synergize when combined to yield ∼15-fold improvements. As a result, iDES-enhanced CAPP-Seq facilitates noninvasive variant detection across hundreds of kilobases. Applied to non-small cell lung cancer (NSCLC) patients, our method enabled biopsy-free profiling of EGFR kinase domain mutations with 92% sensitivity and >99.99% specificity at the variant level, and with 90% sensitivity and 96% specificity at the patient level. In addition, our approach allowed monitoring of NSCLC ctDNA down to 4 in 10(5) cfDNA molecules. We anticipate that iDES will aid the noninvasive genotyping and detection of ctDNA in research and clinical settings. PMID:27018799

  2. Lentivirus-mediated PLCγ1 gene short-hairpin RNA suppresses tumor growth and metastasis of human gastric adenocarcinoma.

    PubMed

    Zhang, Bingchang; Wang, Fen; Dai, Lianzhi; Cai, Heguo; Zhan, Yanyan; Gang, Song; Hu, Tianhui; Xia, Chun; Zhang, Bing

    2016-02-16

    Targeted molecular therapy has gradually been a potential solution in cancer therapy. Other authors' and our previous studies have demonstrated that phosphoinositide-specific phospholipase γ (PLCγ) is involved in regulating tumor growth and metastasis. However, the molecular mechanism underlying PLCγ-dependent tumor growth and metastasis of gastric adenocarcinoma and whether PLCγ may be a potential target for tumor therapy in human gastric adenocarcinoma are not yet well determined. Here, we investigated the role of PLCγ inhibition in tumor growth and metastasis of human gastric adenocarcinoma using BGC-823 cell line and a nude mouse tumor xenograft model. The results manifested that the depletion of PLCγ1 by the transduction with lentivirus-mediated PLCγ1 gene short-hairpin RNA (shRNA) vector led to the decrease of tumor growth and metastasis of human gastric adenocarcinoma in vitro and in vivo. Furthermore, the Akt/Bad, Akt/S6, and ERK/Bad signal axes were involved in PLCγ1-mediated tumor growth and metastasis of human gastric adenocarcinoma. Therefore, the abrogation of PLCγ1 signaling by shRNA could efficaciously suppress human gastric adenocarcinoma tumor growth and metastasis, with important implication for validating PLCγ1 as a potential target for human gastric adenocarcinoma. PMID:26811493

  3. Lentivirus-mediated PLCγ1 gene short-hairpin RNA suppresses tumor growth and metastasis of human gastric adenocarcinoma

    PubMed Central

    Zhang, Bingchang; Wang, Fen; Dai, Lianzhi; Cai, Heguo; Zhan, Yanyan; Gang, Song; Hu, Tianhui; Xia, Chun; Zhang, Bing

    2016-01-01

    Targeted molecular therapy has gradually been a potential solution in cancer therapy. Other authors' and our previous studies have demonstrated that phosphoinositide-specific phospholipase γ (PLCγ) is involved in regulating tumor growth and metastasis. However, the molecular mechanism underlying PLCγ-dependent tumor growth and metastasis of gastric adenocarcinoma and whether PLCγ may be a potential target for tumor therapy in human gastric adenocarcinoma are not yet well determined. Here, we investigated the role of PLCγ inhibition in tumor growth and metastasis of human gastric adenocarcinoma using BGC-823 cell line and a nude mouse tumor xenograft model. The results manifested that the depletion of PLCγ1 by the transduction with lentivirus-mediated PLCγ1 gene short-hairpin RNA (shRNA) vector led to the decrease of tumor growth and metastasis of human gastric adenocarcinoma in vitro and in vivo. Furthermore, the Akt/Bad, Akt/S6, and ERK/Bad signal axes were involved in PLCγ1-mediated tumor growth and metastasis of human gastric adenocarcinoma. Therefore, the abrogation of PLCγ1 signaling by shRNA could efficaciously suppress human gastric adenocarcinoma tumor growth and metastasis, with important implication for validating PLCγ1 as a potential target for human gastric adenocarcinoma. PMID:26811493

  4. Long-term caffeine consumption reverses tumor-induced suppression of the innate immune response in adult mice.

    PubMed

    Mandal, Anup; Poddar, Mrinal K

    2008-12-01

    Caffeine (1,3,7-trimethylxanthine), the active principle alkaloid of coffee ( Coffea arabica) and tea ( Camellia sinensis) possesses a restraining effect on tumor-induced suppression of the specific immune response in adult mice. The present study deals with the effect of long-term consumption of caffeine in the development of Ehrlich ascites carcinoma (EAC) cells in adult Swiss female mice, in relation to the innate immune response and tumor growth. Although the consumption of caffeine alone for more than 12 consecutive days did not affect the innate immune response parameters, continuation of its treatment following intraperitoneal EAC cell inoculation not only reduced the IN VIVO tumor growth but also reduced/restored the EAC cell-induced suppression of the innate immune response. These results suggest that caffeine may inhibit IN VIVO tumor growth through reduction of the cancer cell-induced suppression of the innate immune response. CNS:central nervous system EAC:Ehrlich ascites carcinoma ESR:erythrocyte sedimentation rate GABA:gamma-aminobutyric acid Hb:hemoglobin HPA:hypothalamic-pituitary-adrenal HPG:hypothalamic-pituitary-gonadal PCV:packed cell volume RBC:red blood cell WBC:white blood cell.

  5. Nuclear PTEN regulates the APC-CDH1 tumor-suppressive complex in a phosphatase-independent manner.

    PubMed

    Song, Min Sup; Carracedo, Arkaitz; Salmena, Leonardo; Song, Su Jung; Egia, Ainara; Malumbres, Marcos; Pandolfi, Pier Paolo

    2011-01-21

    PTEN is a frequently mutated tumor suppressor gene that opposes the PI3K/AKT pathway through dephosphorylation of phosphoinositide-3,4,5-triphosphate. Recently, nuclear compartmentalization of PTEN was found as a key component of its tumor-suppressive activity; however its nuclear function remains poorly defined. Here we show that nuclear PTEN interacts with APC/C, promotes APC/C association with CDH1, and thereby enhances the tumor-suppressive activity of the APC-CDH1 complex. We find that nuclear exclusion but not phosphatase inactivation of PTEN impairs APC-CDH1. This nuclear function of PTEN provides a straightforward mechanistic explanation for the fail-safe cellular senescence response elicited by acute PTEN loss and the tumor-suppressive activity of catalytically inactive PTEN. Importantly, we demonstrate that PTEN mutant and PTEN null states are not synonymous as they are differentially sensitive to pharmacological inhibition of APC-CDH1 targets such as PLK1 and Aurora kinases. This finding identifies a strategy for cancer patient stratification and, thus, optimization of targeted therapies. PAPERCLIP:

  6. Nuclear PTEN regulates the APC-CDH1 tumor suppressive complex in a phosphatase-independent manner

    PubMed Central

    Song, Min Sup; Carracedo, Arkaitz; Salmena, Leonardo; Song, Su Jung; Egia, Ainara; Malumbres, Marcos; Pandolfi, Pier Paolo

    2011-01-01

    SUMMARY PTEN is a frequently mutated tumor suppressor gene that opposes the PI3K-AKT pathway through dephosphorylation of phosphoinositide-3,4,5-triphosphate. Recently, nuclear compartmentalization of PTEN was found as a key component of its tumor suppressive activity, however its nuclear function remains poorly defined. Here we show that nuclear PTEN interacts with APC/C, promotes APC/C association with CDH1, and thereby enhances the tumor suppressive activity of the APC-CDH1 complex. We find that nuclear exclusion but not phosphatase inactivation of PTEN impairs APC-CDH1. This nuclear function of PTEN provides a straightforward mechanistic explanation for the fail-safe cellular senescence response elicited by acute PTEN loss and the tumor suppressive activity of catalytically-inactive PTEN. Importantly, we demonstrate that PTEN-mutant and PTEN-null states are not synonymous since they are differentially sensitive to pharmacological inhibition of APC-CDH1 targets such as PLK1 and Aurora Kinases. This finding identifies a strategy for cancer patient stratification and thus, optimization of targeted therapies. PMID:21241890

  7. Tumor suppression in basal keratinocytes via dual non-cell-autonomous functions of a Na,K-ATPase beta subunit

    PubMed Central

    Hatzold, Julia; Beleggia, Filippo; Herzig, Hannah; Altmüller, Janine; Nürnberg, Peter; Bloch, Wilhelm; Wollnik, Bernd; Hammerschmidt, Matthias

    2016-01-01

    The molecular pathways underlying tumor suppression are incompletely understood. Here, we identify cooperative non-cell-autonomous functions of a single gene that together provide a novel mechanism of tumor suppression in basal keratinocytes of zebrafish embryos. A loss-of-function mutation in atp1b1a, encoding the beta subunit of a Na,K-ATPase pump, causes edema and epidermal malignancy. Strikingly, basal cell carcinogenesis only occurs when Atp1b1a function is compromised in both the overlying periderm (resulting in compromised epithelial polarity and adhesiveness) and in kidney and heart (resulting in hypotonic stress). Blockade of the ensuing PI3K-AKT-mTORC1-NFκB-MMP9 pathway activation in basal cells, as well as systemic isotonicity, prevents malignant transformation. Our results identify hypotonic stress as a (previously unrecognized) contributor to tumor development and establish a novel paradigm of tumor suppression. DOI: http://dx.doi.org/10.7554/eLife.14277.001 PMID:27240166

  8. MicroRNA-338-3p suppresses tumor growth of esophageal squamous cell carcinoma in vitro and in vivo.

    PubMed

    Li, Xinyu; Li, Zhihong; Yang, Guiyun; Pan, Zhenxiang

    2015-09-01

    Accumulating evidence has shown that microRNAs (miRNAs) are aberrantly expressed in human esophageal squamous cell carcinoma (ESCC) and are crucial in tumorigenesis, among which miR‑338‑3p has been examined to be downregulated in patients with ESCC. However, the role of miR‑338‑3p in ESCC remains to be elucidated. In the present study, the role of miR‑338‑3p on the growth and survival of an ESCC cell line was determined with several in vitro approaches and in nude mouse models. It was determined that miR‑338‑3p expression was frequently downregulated in ESCC tissue compared with corresponding adjacent non‑tumor tissue, and that its expression was significantly correlated with tumor stage and metastasis. Overexpression of miR‑338‑3p in ESCC cells suppressed cell proliferation, colony formation, migration and invasion, and induced cell arrest at the G0/G1 stage and cell apoptosis in vitro. In addition, it was demonstrated that overexpression of miR‑338‑3p significantly suppresses tumor growth of xenograft tumors in mice (P<0.05). These findings revealed that miR‑338‑3p may act as a tumor suppressor in ESCC, and its dysregulation may be involved in the initiation and development of human ESCC. In addition, it was suggested that miR‑338‑3p may be a potential therapeutic agent for treatment of ESCC.

  9. Wogonin inhibits LPS-induced tumor angiogenesis via suppressing PI3K/Akt/NF-κB signaling.

    PubMed

    Zhao, Kai; Song, Xiuming; Huang, Yujie; Yao, Jing; Zhou, Mi; Li, Zhiyu; You, Qidong; Guo, Qinglong; Lu, Na

    2014-08-15

    Wogonin has been shown to have anti-angiogenesis and anti-tumor effects. However, whether wogonin inhibits LPS-induced tumor angiogenesis is not well known. In this study, we investigated the effect of wogonin on inhibiting LPS-induced tumor angiogenesis and further probed the underlying mechanisms. ELISA results revealed that wogonin could suppress LPS-induced VEGF secretion from tumor cells. Transwell assay, tube formation assay, rat aortic ring assay and CAM model were used to evaluate the effect of wogonin on angiogenesis induced by MCF-7 cell (treated with LPS) in vitro and in vivo. The inhibitory effect of wogonin on angiogenesis in LPS-treated MCF-7 cells was then confirmed by the above in vitro and in vivo assays. The study of the molecular mechanism showed that wogonin could suppress PI3K/Akt signaling activation. Moreover, wogonin inhibited nuclear translocation of NF-κB and its binding to DNA. The result of real-time PCR and luciferase reporter assay suggested that VEGF expression was down-regulated by wogonin primarily at the transcriptional level. IGF-1 and p65 expression plasmid were used to activate PI3K/Akt and NF-κB pathways, and to observe the effect of wogonin on the simualtion of PI3K/Akt/NF-κB signaling. Taken together, the result suggested that wogonin was a potent inhibitor of tumor angiogenesis and provided a new insight into the mechanisms of wogonin against cancer.

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

    PubMed Central

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

    2015-01-01

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

  11. The inhibition of Akt-Pdpk1 interaction efficiently suppresses the growth of murine primary liver tumor cells.

    PubMed

    Mäemets-Allas, Kristina; Belitškin, Denis; Jaks, Viljar

    2016-05-20

    The lack of primary liver tumor cells has hampered testing of potential chemotherapeutic agents in vitro. To overcome this issue we developed a primary mouse liver tumor cell line K07074. The K07074 cells were immortal, exhibited a biliary phenotype, formed colonies in soft agar and displayed an increase in Hedgehog, Notch and Akt signaling. To study the effect of single and combined inhibition of the liver tumor-related pathways on the growth of K07074 cells we treated these with small-molecule antitumor agents. While the inhibition of Akt and Notch pathways strongly inhibited the growth of K07074 cells the inhibition of Wnt and Hedgehog pathways was less efficient in cell growth suppression. Interestingly, the inhibition of Akt pathway at the level of Akt-Pdpk1 interaction was sufficient to suppress the growth of tumor cells and no significant additive effect could be detected when co-treated with the inhibitors of Wnt, Hedgehog or Notch pathways. Only when suboptimal doses of Akt-Pdpk1 interaction inhibitor NSC156529 were used an additive effect with Notch inhibition was seen. We conclude that the Akt pathway inhibitor NSC156529 is potentially useful as single treatment for liver tumors with hyperactivated Akt signaling. PMID:27103434

  12. Proteasome Inhibitors Evoke Latent Tumor Suppression Programs in Pro-B MLL Leukemias Through MLL-AF4

    PubMed Central

    Liu, Han; Westergard, Todd D.; Cashen, Amanda; Piwnica-Worms, David R.; Kunkle, Lori; Vij, Ravi; Pham, Can G.; DiPersio, John; Cheng, Emily H.; Hsieh, James J.

    2014-01-01

    SUMMARY Chromosomal translocations disrupting MLL generate MLL-fusion proteins that induce aggressive leukemias. Unexpectedly, MLL-fusion proteins are rarely observed at high levels, suggesting excessive MLL-fusions may be incompatible with a malignant phenotype. Here, we used clinical proteasome inhibitors, bortezomib and carfilzomib, to reduce the turnover of endogenous MLL-fusions and discovered that accumulated MLL-fusions induce latent, context-dependent tumor suppression programs. Specifically, in MLL pro-B lymphoid, but not myeloid, leukemias, proteasome inhibition triggers apoptosis and cell cycle arrest involving activation cleavage of BID by Caspase-8 and upregulation of p27, respectively. Furthermore, proteasome inhibition conferred preliminary benefit to MLL-AF4 leukemia patients. Hence, feasible strategies to treat cancer-type and oncogene specific cancers can be improvised through harnessing inherent tumor suppression properties of individual oncogenic fusions. PMID:24735925

  13. Suppression of hamster lymphocyte reactivity to simian virus 40 tumor surface antigens by spleen cells from pregnant hamsters

    SciTech Connect

    Weppner, W.A.; Adkinson, L.R.; Coggin, J.H.Jr

    1980-09-01

    SV40-transformed tumor cells in hamsters have been found to have cell surface antigens cross-reactive with antigens temporally expressed on fetal tissues. Using a lymphocyte transformation assay, spleen cells from pregnant hamsters were found to be incapable of responding to preparations of either hamster fetal tissue or SV40-transformed cells. However, a suppressor component can be demonstrated in spleen cell populations of both primi-and multiparous hamsters during pregnancy that is capable of reducing the response of lymphocytes sensitized against SV40 tumor-associated antigens. The degree of suppression is proportional to the ratio of responder cells to spleen cells from pregnant animals. These results suggest there is a subpopulation of spleen cells involved in immunoregulation during pregnancy that has the ability to suppress the reactivity of lymphocytes sensitized against SV40-associated oncofetal antigens.

  14. Adenovirus-mediated ING4 Gene Transfer in Osteosarcoma Suppresses Tumor Growth via Induction of Apoptosis and Inhibition of Tumor Angiogenesis.

    PubMed

    Xu, Ming; Xie, Yufeng; Sheng, Weihua; Miao, Jingcheng; Yang, Jicheng

    2015-08-01

    The inhibitor of growth (ING) family proteins have been defined as candidate tumor suppressors. ING4 as a novel member of ING family has potential tumor-suppressive effects via multiple pathways. However, the therapeutic effect of adenovirus-mediated ING4 (Ad-ING4) gene transfer in human osteosarcoma is still unknown. In this study, we explored the in vitro and in vivo antitumor activity of Ad-ING4 in human osteosarcoma and its potential mechanism using a MG-63 human osteosarcoma cell line. We demonstrated that Ad-ING4 induced significant growth inhibition and apoptosis, upregulated the expression of P21, P27 and Bax, downregulated the Bcl-2 expression and activated Caspase-3 in MG-63 human osteosarcoma cells. Moreover, intratumoral injections of Ad-ING4 in athymic nude mice bearing MG-63 human osteosarcoma tumors significantly suppressed osteosarcoma xenografted tumor growth, increased the expression of P21, P27 and Bax, reduced the Bcl-2 and CD34 expression and microvessel density (MVD) in tumors. This retarded MG-63 osteosarcoma growth in vitro and in vivo in an athymic nude mouse model elicited by Ad-ING4 was closely associated with the increase in the expression of cell cycle-related molecules P21 and P27, decrease in the ratio of anti- to pro-apoptotic molecules Bcl-2/Bax followed by the activation of Caspase-3 leading to apoptosis via intrinsic apoptotic pathways, and the inhibition of tumor angiogenesis. Thus, our results indicate that Ad-ING4 is a potential candidate for human osteosarcoma gene therapy.

  15. Expression of tumor suppressive microRNA-34a is associated with a reduced risk of bladder cancer recurrence.

    PubMed

    Andrew, Angeline S; Marsit, Carmen J; Schned, Alan R; Seigne, John D; Kelsey, Karl T; Moore, Jason H; Perreard, Laurent; Karagas, Margaret R; Sempere, Lorenzo F

    2015-09-01

    Bladder cancer is the fourth most common cancer among men in the United States and more than half of patients experience recurrences within 5 years after initial diagnosis. Additional clinically informative and actionable biomarkers of the recurrent bladder cancer phenotypes are needed to improve screening and molecular therapeutic approaches for recurrence prevention. MicroRNA-34a (miR-34a) is a short noncoding regulatory RNA with tumor suppressive attributes. We leveraged our unique, large, population-based prognostic study of bladder cancer in New Hampshire, United States to evaluate miR-34a expression levels in individual tumor cells to assess prognostic value. We collected detailed exposure and medical history data, as well as tumor tissue specimens from bladder patients and followed them long-term for recurrence, progression and survival. Fluorescence-based in situ hybridization assays were performed on urothelial carcinoma tissue specimens (n = 229). A larger proportion of the nonmuscle invasive tumors had high levels of miR-34a within the carcinoma cells compared to those tumors that were muscle invasive. Patients with high miR-34a levels in their baseline nonmuscle invasive tumors experienced lower risks of recurrence (adjusted hazard ratio 0.57, 95% confidence interval 0.34-0.93). Consistent with these observations, we demonstrated a functional tumor suppressive role for miR-34a in cultured urothelial cells, including reduced matrigel invasion and growth in soft agar. Our results highlight the need for further clinical studies of miR-34a as a guide for recurrence screening and as a possible candidate therapeutic target in the bladder.

  16. Rac1 is required for Prkar1a-mediated Nf2 suppression in Schwann cell tumors.

    PubMed

    Manchanda, P K; Jones, G N; Lee, A A; Pringle, D R; Zhang, M; Yu, L; La Perle, K M D; Kirschner, L S

    2013-07-25

    Schwannomas are peripheral nerve sheath tumors that often occur in the setting of an inherited tumor predisposition syndrome, including neurofibromatosis types 1 (NF1) and 2 (NF2), familial schwannomatosis and Carney complex. Loss of the NF2 tumor suppressor (encoding NF2, or Merlin) is associated with upregulation of the Rac1 small GTPase, which is thought to have a key role in mediating tumor formation. In prior studies, we generated a mouse model of schwannomas by performing tissue-specific knockout (KO) of the Carney complex gene Prkar1a, which encodes the type 1A regulatory subunit of protein kinase A. These tumors exhibited down-regulation of Nf2 protein and an increase in activated Rac1. To assess the requirement for Rac1 in schwannoma formation, we generated a double KO (DKO) of Prkar1a and Rac1 in Schwann cells and monitored tumor formation. Loss of Rac1 reduced tumor formation by reducing proliferation and enhancing apoptosis. Surprisingly, the reduction of tumor formation was accompanied by re-expression of the Nf2 protein. Furthermore, activated Rac1 was able to downregulate Nf2 in vitro in a Pak-dependent manner. These in vivo data indicate that activation of Rac1 is responsible for suppression of Nf2 protein production; deficiency of Nf2 in Schwann cells leads to loss of cellular growth control and tumor formation. Further, PKA activation through mutation in Prkar1a is sufficient to initiate Rac1 signaling, with subsequent reduction of Nf2 and schwannomagenesis. Although in vitro evidence has shown that loss of Nf2 activates Rac1, our data indicate that signaling between Nf2 and Rac1 occurs in a bidirectional fashion, and these interactions are modulated by PKA. PMID:23045281

  17. Rac1 is required for Prkar1a-mediated Nf2 suppression in Schwann cell tumors

    PubMed Central

    Manchanda, Parmeet K.; Jones, Georgette N.; Lee, Audrey A.; Pringle, Daphne R.; Zhang, Mei; Yu, Lianbo; La Perle, Krista M. D.; Kirschner, Lawrence S.

    2012-01-01

    Schwannomas are peripheral nerve sheath tumors that often occur in the setting of an inherited tumor predisposition syndrome, including Neurofibromatosis Types 1 (NF1) and 2 (NF2), Familial Schwannomatosis (FS) and Carney Complex (CNC). Loss of the NF2 tumor suppressor (encoding NF2, or Merlin) is associated with upregulation of the Rac1 small GTPase, which is thought to play a key role in mediating tumor formation. In prior studies, we generated a mouse model of schwannomas by performing tissue-specific knockout of the CNC gene Prkar1a, which encodes the type 1A regulatory subunit of Protein Kinase A. These tumors exhibited down-regulation of Nf2 protein and an increase in activated Rac1. To assess the requirement for Rac1 in schwannoma formation, we generated a double knockout of Prkar1a and Rac1 in Schwann cells and monitored tumor formation. Loss of Rac1 reduced tumor formation by reducing proliferation and enhancing apoptosis. Surprisingly, the reduction of tumor formation was accompanied by re-expression of the Nf2 protein. Furthermore, activated Rac1 was able to downregulate Nf2 in vitro in a Pak-dependent manner. These in vivo data indicate that activation of Rac1 is responsible for suppression of Nf2 protein production; deficiency of Nf2 in Schwann cells leads to loss of cellular growth control and tumor formation.. Further, PKA activation through mutation in Prkar1a is sufficient to initiate Rac1 signaling, with subsequent reduction of Nf2 and schwannomagenesis. Although in vitro evidence has shown that loss of Nf2 activates Rac1, our data indicates that signaling between Nf2 and Rac1 occurs in a bidirectional fashion, and these interactions are modulated by PKA. PMID:23045281

  18. Radiofrequency Ablation of Liver Tumors in Combination with Local OK-432 Injection Prolongs Survival and Suppresses Distant Tumor Growth in the Rabbit Model with Intra- and Extrahepatic VX2 Tumors

    SciTech Connect

    Kageyama, Ken Yamamoto, Akira Okuma, Tomohisa Hamamoto, Shinichi Takeshita, Toru Sakai, Yukimasa Nishida, Norifumi Matsuoka, Toshiyuki Miki, Yukio

    2013-10-15

    Purpose: To evaluate survival and distant tumor growth after radiofrequency ablation (RFA) and local OK-432 injection at a single tumor site in a rabbit model with intra- and extrahepatic VX2 tumors and to examine the effect of this combination therapy, which we termed immuno-radiofrequency ablation (immunoRFA), on systemic antitumor immunity in a rechallenge test. Methods: Our institutional animal care committee approved all experiments. VX2 tumors were implanted to three sites: two in the liver and one in the left ear. Rabbits were randomized into four groups of seven to receive control, RFA alone, OK-432 alone, and immunoRFA treatments at a single liver tumor at 1 week after implantation. Untreated liver and ear tumor volumes were measured after the treatment. As the rechallenge test, tumors were reimplanted into the right ear of rabbits, which survived the 35 weeks and were followed up without additional treatment. Statistical significance was examined by log-rank test for survival and Student's t test for tumor volume. Results: Survival was significantly prolonged in the immunoRFA group compared to the other three groups (P < 0.05). Untreated liver and ear tumor sizes became significantly smaller after immunoRFA compared to controls (P < 0.05). In the rechallenge test, the reimplanted tumors regressed without further therapy compared to the ear tumors of the control group (P < 0.05). Conclusion: ImmunoRFA led to improved survival and suppression of distant untreated tumor growth. Decreases in size of the distant untreated tumors and reimplanted tumors suggested that systemic antitumor immunity was enhanced by immunoRFA.

  19. IMP1 suppresses breast tumor growth and metastasis through the regulation of its target mRNAs

    PubMed Central

    Liu, Xin; Huang, Wenhe; Chen, Shaoying; Zhou, Yanchun; Li, Deling; Singer, Robert H.; Gu, Wei

    2016-01-01

    We have previously reported the ability of IMP1 in inhibiting proliferation and invasiveness of breast carcinoma cells in vitro. In the current study, we utilized a mouse xenograft model to further investigate the function of IMP1 in breast tumor progression and its underlying mechanism. We demonstrated that IMP1 expression significantly suppressed the growth of MDA231 cell-derived xenograft tumors and subsequent lung metastasis. Microarray analyses and differential gene expression identified handful mRNAs, many of which were involved in breast tumor-growth and metastasis. Further studies revealed that these mRNAs were directly interacted with the KH34 domain of IMP1 and this interaction post-transcriptionally regulated their corresponding protein expression. Either deletion of the KH34 domain of IMP1 or alteration of the expression of IMP1-bound mRNAs affected cell proliferation and tumor growth, producing the same phenotypes as IMP1 knockdown. Correlation of increased IMP1 expression with the reduced levels of its bound mRNAs, such as PTGS2, GDF15 and IGF-2 transcripts, was also observed in human breast tumors. Our studies provide insights into a molecular mechanism that the positive function of IMP1 to inhibit breast tumor growth and metastasis could be through the regulation of its target mRNAs. PMID:26910917

  20. TRANSFORMING GROWTH FACTOR-BETA MEDIATED SUPPRESSION OF ANTI-TUMOR T CELLS REQUIRES FOXP1 TRANSCRIPTION FACTOR EXPRESSION

    PubMed Central

    Stephen, Tom L.; Rutkowski, Melanie R.; Allegrezza, Michael J.; Perales-Puchalt, Alfredo; Tesone, Amelia J.; Svoronos, Nikolaos; Nguyen, Jenny M.; Sarmin, Fahmida; Borowsky, Mark E.; Tchou, Julia; Conejo-Garcia, Jose R.

    2014-01-01

    SUMMARY Tumor-reactive T cells become unresponsive in advanced tumors. Here we have characterized a common mechanism of T cell unresponsiveness in cancer driven by the up-regulation of the transcription factor Forkhead box protein P1 (Foxp1), which prevents CD8+ T cells from proliferating and up-regulating Granzyme-B and interferon-γ (IFN-γ) in response to tumor antigens. Accordingly, Foxp1-deficient lymphocytes induced rejection of incurable tumors, and promoted protection against tumor re-challenge. Mechanistically, Foxp1 interacted with the transcription factors Smad2 and Smad3 in pre-activated CD8+ T cells in response to microenvironmental transforming growth factor-β (TGF-β), and was essential for its suppressive activity. Therefore, Smad2 and Smad3-mediated c-Myc repression requires Foxp1 expression in T cells. Furthermore, Foxp1 directly mediated TGF-β-induced c-Jun transcriptional repression, which abrogated T cell activity. Our results unveil a fundamental mechanism of T cell unresponsiveness different from anergy or exhaustion, driven by TGF-β signaling on tumor-associated lymphocytes undergoing Foxp1-dependent transcriptional regulation. PMID:25238097

  1. Influence of chronic prolactin suppression during puberty on the development of dimethylbenz(a)anthracene-induced mammary tumors (41163). [Rats

    SciTech Connect

    Cohen, L.A.

    1981-06-01

    In order to assess the effect of early prolactin suppression on the subsequent development of dimethylbenz(a)anthracene (DMBA)-induced mammary cancers, the dopamine agonist, CB-154, was chronically administered to female Sprague-Dawley rats from Day 35 to Day 50 of age. DMBA was then administered and tumor development assessed over a 25-week period. It was found that animals treated with CB-154 exhibited decreased tumor incidence, a longer latent period, and fewer tumors/animal, when compared to vehicle controls. These results are consistent with the hypothesis that the sensitivity of the mammary gland to polycyclic aromatic hydrocarbon (PAH) carcinogenesis is determined by the level of differentiation of the gland at the time of carcinogen administration. Accordingly, perturbations in prolactin secretion patterns, early in life, may accelerate or retard the differentiation of the mammary gland thereby rendering it less susceptible to the carcinogenic effects of PAH.

  2. Sunitinib (SUTENT, SU11248) suppresses tumor growth and induces apoptosis in xenograft models of human hepatocellular carcinoma.

    PubMed

    Huynh, H; Ngo, V C; Choo, S P; Poon, D; Koong, H N; Thng, C H; Toh, H C; Zheng, L; Ong, L C; Jin, Y; Song, I C; Chang, A P C; Ong, H S; Chung, A Y F; Chow, P K H; Soo, K C

    2009-09-01

    Hepatocellular carcinoma (HCC) is the fifth most common and third deadliest primary neoplasm. Since HCC is a particularly vascular solid tumor, we determined the antitumor and antiangiogenic activities of sunitinib malate, a potent inhibitor of two receptors involved in angiogenesis - vascular endothelial growth factor receptor (VEGFR) and platelet-derived growth factor receptor (PDGFR). In the present study, we reported that treatment of HepG2 and SK-Hep-1 cells with sunitinib led to growth inhibition and apoptosis in a dose-dependent fashion. Sunitinib inhibited phosphorylation of VEGFR-2 at Tyr951 and PDGFR-beta at Tyr1021 both in vitro and in vivo. Sunitinib also suppressed tumor growth of five patient-derived xenografts. Sunitinib-induced tumor growth inhibition was associated with increased apoptosis, reduced microvessel density and inhibition of cell proliferation. This study provides a strong rationale for further clinical investigation of sunitinib in patients with hepatocellular carcinoma.

  3. A low carbohydrate, high protein diet suppresses intratumoral androgen synthesis and slows castration-resistant prostate tumor growth in mice.

    PubMed

    Fokidis, H Bobby; Yieng Chin, Mei; Ho, Victor W; Adomat, Hans H; Soma, Kiran K; Fazli, Ladan; Nip, Ka Mun; Cox, Michael; Krystal, Gerald; Zoubeidi, Amina; Tomlinson Guns, Emma S

    2015-06-01

    likely to be mechanistic drivers behind the observed tumor growth suppression. PMID:25797030

  4. A low carbohydrate, high protein diet suppresses intratumoral androgen synthesis and slows castration-resistant prostate tumor growth in mice.

    PubMed

    Fokidis, H Bobby; Yieng Chin, Mei; Ho, Victor W; Adomat, Hans H; Soma, Kiran K; Fazli, Ladan; Nip, Ka Mun; Cox, Michael; Krystal, Gerald; Zoubeidi, Amina; Tomlinson Guns, Emma S

    2015-06-01

    likely to be mechanistic drivers behind the observed tumor growth suppression.

  5. miR-218 suppresses tumor growth and enhances the chemosensitivity of esophageal squamous cell carcinoma to cisplatin.

    PubMed

    Tian, Hang; Hou, Lei; Xiong, Yu-Mei; Huang, Jun-Xiang; She, Ying-Jun; Bi, Xiao-Bao; Song, Xing-Rong

    2015-02-01

    A growing body of evidence suggests that microRNA-218 (miR-218) acts as a tumor suppressor and is involved in tumor progression, development and metastasis and confers sensitivity to certain chemotherapeutic drugs in several types of cancer. However, our knowledge concerning the exact roles played by miR-218 in esophageal squamous cell carcinoma (ESCC) and the underlying molecular mechanisms remain relatively unclear. Thus, the aims of this study were to detect the expression of miR-218 in human ESCC tissues and explore its effects on the biological features and chemosensitivity to cisplatin (CDDP) in an ESCC cell line (Eca109), so as to provide new insights for ESCC treatment. Here, we found increased expression of miR-218 in the ESCC tissues compared with that in the matched non-tumor tissues, and its expression level was correlated with key pathological characteristics including clinical stage, tumor depth and metastasis. We also found that enforced expression of miR-218 significantly decreased cell proliferation, colony formation, migration and invasion, induced cell apoptosis and arrested the cell cycle in the G0/G1 phase, as well as suppressed tumor growth in a nude mouse model. In addition, our results showed that miR-218 mimics increased the sensitivity to the antitumor effect of CDDP in the human Eca109 cells. Importantly, this study also showed that miR-218 regulated the expression of phosphorylated PI3K, AKT and mTOR, which may contribute to suppressed tumor growth of ESCC and enhanced sensitivity of ESCC cells. These findings suggest that miR-218 is a potential therapeutic agent for the treatment of ESCC.

  6. Extremely High Expression of Antisense RNA for Wilms' Tumor 1 in Active Osteoclasts: Suppression of Wilms' Tumor 1 Protein Expression during Osteoclastogenesis.

    PubMed

    Li, Yin-Ji; Kukita, Akiko; Kyumoto-Nakamura, Yukari; Kukita, Toshio

    2016-09-01

    Wilms' tumor 1 (WT1), a zinc-finger transcription regulator of the early growth response family, identified as the product of a tumor suppressor gene of Wilms' tumors, bears potential ability to induce macrophage differentiation in blood cell differentiation. Herein, we examined the involvement of WT1 in the regulation of osteoclastogenesis. We detected a high level of WT1 protein expression in osteoclast precursors; however, WT1 expression was markedly suppressed during osteoclastogenesis. We examined expression of WT1 transcripts in bone tissue by RNA in situ hybridization. We found a high level of antisense transcripts in osteoclasts actively resorbing bone in mandible of newborn rats. Expression of antisense WT1 RNA in mandible was also confirmed by Northern blot analysis and strand-specific RT-PCR. Overexpression of antisense WT1 RNA in RAW-D cells, an osteoclast precursor cell line, resulted in a marked enhancement of osteoclastogenesis, suggesting that antisense WT1 RNA functions to suppress expression of WT1 protein in osteoclastogenesis. High level expression of antisense WT1 RNA may contribute to commitment to osteoclastogenesis, and may allow osteoclasts to maintain or stabilize their differentiation state.

  7. Fe3O4-citrate-curcumin: Promising conjugates for superoxide scavenging, tumor suppression and cancer hyperthermia

    NASA Astrophysics Data System (ADS)

    Kitture, Rohini; Ghosh, Sougata; Kulkarni, Parag; Liu, X. L.; Maity, Dipak; Patil, S. I.; Jun, Ding; Dushing, Yogesh; Laware, S. L.; Chopade, B. A.; Kale, S. N.

    2012-03-01

    Fe3O4 nanoparticles have been conjugated to curcumin (CU) molecules via a citrate (CA) linker (Fe-CA-CU) and have been explored for superoxide scavenging, tumor suppression, and cancer hyperthermia. The conjugation chemistry reveals that Fe3+ ions on the nanoparticle surface readily conjugates to the available carboxyl sites on the CA molecule, which further conjugates to CU at its central enol -OH group. As seen from the UV-vis spectroscopy, the therapeutically active chromophore group of CU, which is seen at 423 nm, was intact, ensuring the activity the molecule. Magnetization measurements showed good hysteresis curves of Fe3O4 and Fe-CA-CU, indicating the presence of magnetism after conjugation. The loading percentage of citrate-curcumin was seen to be ˜10% from the thermo-gravimetric analysis. The systems when subjected to radio-frequency fields of 240 KHz, were seen to get heated up. The Fe3O4 heating exhibited better slope (1 °C/s) as compared to the Fe-CA-CU system (˜0.7 °C/s) for a sample of concentration 10 mg/ml in average time of ˜20 s to reach the required hyperthermia threshold temperature of ˜45 °C. Tumor suppression studies were done using potato assay, which showed that while only CU showed 100% suppression in 7 days, it was about 89% by the Fe-CA-CU. Upon subjecting these systems to the superoxide anion scavenging assay and superoxide radical scavenging assay (riboflavin), it was observed that the activity was enhanced in the Fe-CA-CU to 40% (from 38% in only CU) and 100% (from 5.75% in only CU). These studies promise Fe-CA-CU as a good cancer hyperthermia-cum-tumor suppressant and antioxidant agent.

  8. Small molecule 1'-acetoxychavicol acetate suppresses breast tumor metastasis by regulating the SHP-1/STAT3/MMPs signaling pathway.

    PubMed

    Wang, Jieqiong; Zhang, Li; Chen, Guoliang; Zhang, Jing; Li, Zhenxi; Lu, Weiqiang; Liu, Mingyao; Pang, Xiufeng

    2014-11-01

    Signal transducer and activator of transcription 3 (STAT3) is implicated breast cancer metastasis and represents a potential target for developing new anti-tumor metastasis drugs. The purpose of this study is to investigate whether the natural agent 1'-acetoxychavicol acetate (ACA), derived from the rhizomes and seeds of Languas galanga, could suppress breast cancer metastasis by targeting STAT3 signaling pathway. ACA was examined for its effects on breast cancer migration/invasion and metastasis using Transwell assays in vitro and breast cancer skeletal metastasis mouse model in vivo (n = 10 mice per group). The inhibitory effect of ACA on cellular STAT3 signaling pathway was investigated by series of biochemistry analysis. The chavicol preferentially suppressed cancer cell migration and invasion, and this activity was superior to its cytotoxic effects. ACA suppressed both constitutive and interleukin-6-inducible STAT3 activation and diminished the accumulation of STAT3 in the nucleus and its DNA-binding activity. More importantly, ACA treatment led to significant up-regulation of Src homology region 2 domain-containing phosphatase 1 (SHP-1), and the ACA-induced depression of cancer cell migration and STAT3 signaling could be apparently reversed by blockade of SHP-1. Matrix metalloproteinase (MMP)-2 and -9, gene products of STAT3 that regulate cell invasion, were specifically suppressed by ACA. In tumor metastasis model, ACA potently inhibited the human breast cancer cell-induced osteolysis, and had little apparent in vivo toxicity at the test concentrations. ACA is a novel drug candidate for the inhibition of tumor metastasis through interference with the SHP-1/STAT3/MMPs signaling pathway.

  9. Pharmacological Inhibition of Microsomal Prostaglandin E Synthase-1 Suppresses Epidermal Growth Factor Receptor-Mediated Tumor Growth and Angiogenesis

    PubMed Central

    Bocci, Elena; Coletta, Isabella; Polenzani, Lorenzo; Mangano, Giorgina; Alisi, Maria Alessandra; Cazzolla, Nicola; Giachetti, Antonio; Ziche, Marina; Donnini, Sandra

    2012-01-01

    Background Blockade of Prostaglandin (PG) E2 production via deletion of microsomal Prostaglandin E synthase-1 (mPGES-1) gene reduces tumor cell proliferation in vitro and in vivo on xenograft tumors. So far the therapeutic potential of the pharmacological inhibition of mPGES-1 has not been elucidated. PGE2 promotes epithelial tumor progression via multiple signaling pathways including the epidermal growth factor receptor (EGFR) signaling pathway. Methodology/Principal Findings Here we evaluated the antitumor activity of AF3485, a compound of a novel family of human mPGES-1 inhibitors, in vitro and in vivo, in mice bearing human A431 xenografts overexpressing EGFR. Treatment of the human cell line A431 with interleukin-1beta (IL-1β) increased mPGES-1 expression, PGE2 production and induced EGFR phosphorylation, and vascular endothelial growth factor (VEGF) and fibroblast growth factor-2 (FGF-2) expression. AF3485 reduced PGE2 production, both in quiescent and in cells stimulated by IL-1β. AF3485 abolished IL-1β-induced activation of the EGFR, decreasing VEGF and FGF-2 expression, and tumor-mediated endothelial tube formation. In vivo, in A431 xenograft, AF3485, administered sub-chronically, decreased tumor growth, an effect related to inhibition of EGFR signalling, and to tumor microvessel rarefaction. In fact, we observed a decrease of EGFR phosphorylation, and VEGF and FGF-2 expression in tumours explanted from treated mice. Conclusion Our work demonstrates that the pharmacological inhibition of mPGES-1 reduces squamous carcinoma growth by suppressing PGE2 mediated-EGFR signalling and by impairing tumor associated angiogenesis. These results underscore the potential of mPGES-1 inhibitors as agents capable of controlling tumor growth. PMID:22815767

  10. miR-129 suppresses tumor cell growth and invasion by targeting PAK5 in hepatocellular carcinoma

    SciTech Connect

    Zhai, Jian; Qu, Shuping; Li, Xiaowei; Zhong, Jiaming; Chen, Xiaoxia; Qu, Zengqiang; Wu, Dong

    2015-08-14

    Emerging evidence suggests that microRNAs (miRNAs) play important roles in regulating HCC development and progression; however, the mechanisms by which their specific functions and mechanisms remained to be further explored. miR-129 has been reported in gastric cancers, lung cancer and colon cancer. In this study, we disclosed a new tumor suppresser function of miR-129 in HCC. We also found the downregulation of miR-129 occurred in nearly 3/4 of the tumors examined (56/76) compared with adjacent nontumorous tissues, which was more importantly, correlated to the advanced stage and vascular invasion. We then demonstrated that miR-129 overexpression attenuated HCC cells proliferation and invasion, inducing apoptosis in vitro. Moreover, we used miR-129 antagonist and found that anti-miR-129 promoted HCC cells malignant phenotypes. Mechanistically, our further investigations revealed that miR-129 suppressed cell proliferation and invasion by targeting the 3’-untranslated region of PAK5, as well as miR-129 silencing up-regulated PAK5 expression. Moreover, miR-129 expression was inversely correlated with PAK5 expression in 76 cases of HCC samples. RNA interference of PAK5 attenuated anti-miR-129 mediated cell proliferation and invasion in HCC cells. Taken together, these results demonstrated that miR-129 suppressed tumorigenesis and progression by directly targeting PAK5, defining miR-129 as a potential treatment target for HCC. - Highlights: • Decreased of miR-129 is found in HCC and associated with advanced stage and metastasis. • miR-129 suppresses proliferation and invasion of HCC cells. • miR-129 directly targets the 3′ UTR of PAK5 and diminishes PAK5 expression. • PAK5 is involved in miR-129 mediated suppression functions.

  11. Polymeric Nanostructure Compiled with Multifunctional Components To Exert Tumor-Targeted Delivery of Antiangiogenic Gene for Tumor Growth Suppression.

    PubMed

    Chen, Qixian; Qi, Ruogu; Chen, Xiyi; Yang, Xi; Huang, Xing; Xiao, Haihua; Wang, Xinhuan; Dong, Wenfei

    2016-09-21

    Nucleic acid-based therapy has emerged as a revolutionary methodology for treatment of the diseases related to protein dysfunction; however, lack of systemically applicable synthetic delivery systems limits its current usage in local applications, particularly for DNA-based therapy with regard to the poor bioavailability in the systemic administrations. To overcome this obstacle, we compiled multiple chemistry-based strategies into the manufacture of the gene delivery formulations to pursue improved tolerability of DNA to the enzymatic degradation in the biological milieu and prolonged retention in the systemic circulation. Here, we constructed a distinctive multilayered functional architecture: plasmid DNA (pDNA) was electrostatically complexed with cationic poly(lysine) (polyplex) as the interior pDNA reservoir, which was further cross-linked by redox-responsive disulfide cross-linking to minimize the occurrence of polyplex disassembly through exchange reaction with the biological charged components. Still, the pDNA reservoir was spatially protected by a sequential thermoresponsive poly(N-isopropylacrylamide) palisade as the intermediate barrier and a biocompatible hydrophilic poly(ethylene glycol) (PEG) shell with the aim of preventing the accessibility of the biological species, particularly the nuclease degradation to the pDNA payload. Subsequent investigations validated the utilities of these strategies in accomplishing prolonged blood retention. In an attempt to apply this method for tumor therapy, ligand cyclic (Arg-Gly-Asp) peptide was attached at the distal end of PEG, validating prompted tumor-targeted delivery and gene expression of the loaded antiangiogenic gene at the targeted tumor cells and accordingly exerting antiangiogenesis of the tumors for abrogation of tumor growth. Together with its excellent safe profile, the proposed formulation suggests potential utility as a practical gene delivery system for treatment of intractable diseases. PMID

  12. The Growth of SGC-7901 Tumor Xenografts Was Suppressed by Chinese Bayberry Anthocyanin Extract through Upregulating KLF6 Gene Expression

    PubMed Central

    Wang, Yue; Zhang, Xia-nan; Xie, Wen-hua; Zheng, Yi-xiong; Cao, Jin-ping; Cao, Pei-rang; Chen, Qing-jun; Li, Xian; Sun, Chong-de

    2016-01-01

    To investigate the antitumor effect of anthocyanins extracted from Chinese bayberry fruit (Myrica rubra Sieb. et Zucc.), a nude mouse tumor xenograft model was established. Treatments with C3G (cyanidin-3-glucoside, an anthocyanin) significantly suppressed the growth of SGC-7901 tumor xenografts in a dose-dependent manner. Immunohistochemical staining showed a significant increase in p21 expression, indicating that the cell cycle of tumor xenografts was inhibited. qPCR screening showed that C3G treatment up-regulated the expression of the KLF6 gene, which is an important tumor suppressor gene inactivated in many human cancers. Western blot showed that C3G treatments markedly increased KLF6 and p21 protein levels, inhibited CDK4 and Cyclin D1 expression, but did not notably change the expression of p53. These results indicated that KLF6 up-regulates p21 in a p53-independent manner and significantly reduces tumor proliferation. This study provides important information for the possible mechanism of C3G-induced antitumor activity against gastric adenocarcinoma in vivo. PMID:27690088

  13. Nutritional and supranutritional levels of selenate differentially suppress prostate tumor growth in adult but not young nude mice.

    PubMed

    Holmstrom, Alexandra; Wu, Ryan T Y; Zeng, Huawei; Lei, K Y; Cheng, Wen-Hsing

    2012-09-01

    The inhibitory effect of oral methylseleninic acid or methylselenocysteine administration on cancer cell xenograft development in nude mice is well characterized; however, less is known about the efficacy of selenate and age on selenium chemoprevention. In this study, we tested whether selenate and duration on diets would regulate prostate cancer xenograft in nude mice. Thirty-nine homozygous NU/J nude mice were fed a selenium-deficient, Torula yeast basal diet alone (Se-) or supplemented with 0.15 (Se) or 1.0 (Se+) mg selenium/kg (as Na₂SeO₄) for 6 months in Experiment 1 and for 4 weeks in Experiment 2, followed by a 47-day PC-3 prostate cancer cell xenograft on the designated diet. In Experiment 1, the Se- diet enhanced the initial tumor development on days 11-17, whereas the Se+ diet suppressed tumor growth on days 35-47 in adult nude mice. Tumors grown in Se- mice were loosely packed and showed increased necrosis and inflammation as compared to those in Se and Se+ mice. In Experiment 2, dietary selenium did not affect tumor development or histopathology throughout the time course. In both experiments, postmortem plasma selenium concentrations in Se and Se+ mice were comparable and were twofold greater than those in Se- mice. Taken together, dietary selenate at nutritional and supranutritional levels differentially inhibit tumor development in adult, but not young, nude mice engrafted with PC-3 prostate cancer cells.

  14. Disialoganglioside GD2 on human neuroblastoma cells: target antigen for monoclonal antibody-mediated cytolysis and suppression of tumor growth.

    PubMed

    Mujoo, K; Cheresh, D A; Yang, H M; Reisfeld, R A

    1987-02-15

    A murine monoclonal antibody 14.18 specifically recognizes disialoganglioside GD2, the major ganglioside expressed on the surface of human neuroblastoma cells. This monoclonal antibody (Mab) is of immunoglobulin G3 isotype, has an affinity constant (KA) of 3.5 X 10(8) M-1, and reacts preferentially with tumor cells and fresh frozen tumor tissues of neuroectodermal origin in enzyme-linked immunosorbent assay and immunoperoxidase assays, respectively. Mab 14.18 effectively lyses a number of human neuroblastoma cell lines by two distinct mechanisms, i.e., antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity. There is a good correlation between the average number of antibody-binding sites per neuroblastoma cell and the amount of cell lysis observed in complement-dependent cytotoxicity and antibody-dependent cellular cytotoxicity. In addition, Mab 14.18 suppresses establishment as well as growth of progressively growing, established human neuroblastoma tumors in nude mice when injected 24 h and 9 days, respectively, after the initial s.c. inoculation of tumor cells. These data suggest that Mab 14.18 can mediate tumor cell killing in vivo and in vitro and may thereby prove useful for immunotherapy of human neuroblastoma.

  15. MicroRNA-588 suppresses tumor cell migration and invasion by targeting GRN in lung squamous cell carcinoma

    PubMed Central

    Qian, Li; Lin, Longlong; Du, Yufeng; Hao, Xiaoyan; Zhao, Yuze; Liu, Xuejun

    2016-01-01

    MicroRNAs (miRNAs) have been demonstrated to be critical in regulating tumor development and progression. The present study investigated the expression of miR-588 using reverse transcription-quantitative polymerase chain reaction analysis in 85 cases of lung squamous cell carcinoma (SCC), and observed the correlation between the expression of miR-588 with clinical pathologic features. The results indicated that the expression of miR-588 was predominantly lower in the tumor samples, compared with non-tumorous samples, and was negatively associated with tumor stages and lymph node invasion. The present study also examined the significance of the expression of miR-588 in SCC using gain- and loss-of-function analyses. It was found that miR-588 inhibited tumor cell migration and invasion. In addition, it was revealed that the overexpression of miR-588 in SCC cells reduced the mRNA and protein levels of progranulin (GRN), whereas miR-588 silencing increased the expression of GRN. A luciferase activity assay showed that miR-588 was able to directly bind to the 3′untranslated region of GRN and regulate its expression. Furthermore, it was found that the expression of GRN was inversely correlated with the expression of miR-588 in 85 paired SCC samples. These results indicated that GRN was involved in the miR-588-mediated suppressive functions in the progression of SCC. PMID:27571908

  16. Tumor growth suppression by gadolinium-neutron capture therapy using gadolinium-entrapped liposome as gadolinium delivery agent.

    PubMed

    Dewi, Novriana; Yanagie, Hironobu; Zhu, Haito; Demachi, Kazuyuki; Shinohara, Atsuko; Yokoyama, Kazuhito; Sekino, Masaki; Sakurai, Yuriko; Morishita, Yasuyuki; Iyomoto, Naoko; Nagasaki, Takeshi; Horiguchi, Yukichi; Nagasaki, Yukio; Nakajima, Jun; Ono, Minoru; Kakimi, Kazuhiro; Takahashi, Hiroyuki

    2013-07-01

    Neutron capture therapy (NCT) is a promising non-invasive cancer therapy approach and some recent NCT research has focused on using compounds containing gadolinium as an alternative to currently used boron-10 considering several advantages that gadolinium offers compared to those of boron. In this study, we evaluated gadolinium-entrapped liposome compound as neutron capture therapy agent by in vivo experiment on colon-26 tumor-bearing mice. Gadolinium compound were injected intravenously via tail vein and allowed to accumulate into tumor site. Tumor samples were taken for quantitative analysis by ICP-MS at 2, 12, and 24 h after gadolinium compound injection. Highest gadolinium concentration was observed at about 2 h after gadolinium compound injection with an average of 40.3 μg/g of wet tumor tissue. We performed neutron irradiation at JRR-4 reactor facility of Japan Atomic Energy Research Institute in Tokaimura with average neutron fluence of 2×10¹² n/cm². The experimental results showed that the tumor growth suppression of gadolinium-injected irradiated group was revealed until about four times higher compared to the control group, and no significant weight loss were observed after treatment suggesting low systemic toxicity of this compound. The gadolinium-entrapped liposome will become one of the candidates for Gd delivery system on NCT.

  17. Hyaluronidase expression by an oncolytic adenovirus enhances its intratumoral spread and suppresses tumor growth.

    PubMed

    Guedan, Sonia; Rojas, Juan José; Gros, Alena; Mercade, Elena; Cascallo, Manel; Alemany, Ramon

    2010-07-01

    Successful virotherapy requires efficient virus spread within tumors. We tested whether the expression of hyaluronidase, an enzyme which dissociates the extracellular matrix (ECM), could enhance the intratumoral distribution of an oncolytic adenovirus and improve its therapeutic activity. As a proof of concept, we demonstrated that intratumoral coadministration of hyaluronidase in mice-bearing tumor xenografts improves the antitumor activity of an oncolytic adenovirus. Next, we constructed a replication-competent adenovirus expressing a soluble form of the human sperm hyaluronidase (PH20) under the control of the major late promoter (MLP) (AdwtRGD-PH20). Intratumoral treatment of human melanoma xenografts with AdwtRGD-PH20 resulted in degradation of hyaluronan (HA), enhanced viral distribution, and induced tumor regression in all treated tumors. Finally, the PH20 cDNA was inserted in an oncolytic adenovirus that selectively kills pRb pathway-defective tumor cells. The antitumoral activity of the novel oncolytic adenovirus expressing PH20 (ICOVIR17) was compared to that of the parental virus ICOVIR15. ICOVIR17 showed more antitumor efficacy following intratumoral and systemic administration in mice with prestablished tumors, along with an improved spread of the virus within the tumor. Importantly, a single intravenous dose of ICOVIR17 induced tumor regression in 60% of treated tumors. These results indicate that ICOVIR17 is a promising candidate for clinical testing.

  18. Resveratrol and Black Tea Polyphenol Combination Synergistically Suppress Mouse Skin Tumors Growth by Inhibition of Activated MAPKs and p53

    PubMed Central

    George, Jasmine; Singh, Madhulika; Srivastava, Amit Kumar; Bhui, Kulpreet; Roy, Preeti; Chaturvedi, Pranav Kumar; Shukla, Yogeshwer

    2011-01-01

    Cancer chemoprevention by natural dietary agents has received considerable importance because of their cost-effectiveness and wide safety margin. However, single agent intervention has failed to bring the expected outcome in clinical trials; therefore, combinations of chemopreventive agents are gaining increasing popularity. The present study aims to evaluate the combinatorial chemopreventive effects of resveratrol and black tea polyphenol (BTP) in suppressing two-stage mouse skin carcinogenesis induced by DMBA and TPA. Resveratrol/BTP alone treatment decreased tumor incidence by ∼67% and ∼75%, while combination of both at low doses synergistically decreased tumor incidence even more significantly by ∼89% (p<0.01). This combination also significantly regressed tumor volume and number (p<0.01). Mechanistic studies revealed that this combinatorial inhibition was associated with decreased expression of phosphorylated mitogen-activated protein kinase family proteins: extracellular signal-regulated kinase 1/2, c-Jun N-terminal kinase 1/2, p38 and increased in total p53 and phospho p53 (Ser 15) in skin tissue/tumor. Treatment with combinations of resveratrol and BTP also decreased expression of proliferating cell nuclear antigen in mouse skin tissues/tumors than their solitary treatments as determined by immunohistochemistry. In addition, histological and cell death analysis also confirmed that resveratrol and BTP treatment together inhibits cellular proliferation and markedly induces apoptosis. Taken together, our results for the first time lucidly illustrate that resveratrol and BTP in combination impart better suppressive activity than either of these agents alone and accentuate that development of novel combination therapies/chemoprevention using dietary agents will be more beneficial against cancer. This promising combination should be examined in therapeutic trials of skin and possibly other cancers. PMID:21887248

  19. The alternative medicine pawpaw and its acetogenin constituents suppress tumor angiogenesis via the HIF-1/VEGF pathway.

    PubMed

    Coothankandaswamy, Veena; Liu, Yang; Mao, Shui-Chun; Morgan, J Brian; Mahdi, Fakhri; Jekabsons, Mika B; Nagle, Dale G; Zhou, Yu-Dong

    2010-05-28

    Products that contain twig extracts of pawpaw (Asimina triloba) are widely consumed anticancer alternative medicines. Pawpaw crude extract (CE) and purified acetogenins inhibited hypoxia-inducible factor-1 (HIF-1)-mediated hypoxic signaling pathways in tumor cells. In T47D cells, pawpaw CE and the acetogenins 10-hydroxyglaucanetin (1), annonacin (2), and annonacin A (3) inhibited hypoxia-induced HIF-1 activation with IC(50) values of 0.02 microg/mL, 12 nM, 13 nM, and 31 nM, respectively. This inhibition correlates with the suppression of the hypoxic induction of HIF-1 target genes VEGF and GLUT-1. The induction of secreted VEGF protein represents a key event in hypoxia-induced tumor angiogenesis. Both the extract and the purified acetogenins blocked the angiogenesis-stimulating activity of hypoxic T47D cells in vitro. Pawpaw extract and acetogenins inhibited HIF-1 activation by blocking the hypoxic induction of nuclear HIF-1alpha protein. The inhibition of HIF-1 activation was associated with the suppression of mitochondrial respiration at complex I. Thus, the inhibition of HIF-1 activation and hypoxic tumor angiogenesis constitutes a novel mechanism of action for these anticancer alternative medicines. PMID:20423107

  20. A reason for intermittent fasting to suppress the awakening of dormant breast tumors.

    PubMed

    Lankelma, Jan; Kooi, Bob; Krab, Klaas; Dorsman, Josephine C; Joenje, Hans; Westerhoff, Hans V

    2015-01-01

    For their growth, dormant tumors, which lack angiogenesis may critically depend on gradients of nutrients and oxygen from the nearest blood vessel. Because for oxygen depletion the distance from the nearest blood vessel to depletion will generally be shorter than for glucose depletion, such tumors will contain anoxic living tumor cells. These cells are dangerous, because they are capable of inducing angiogenesis, which will "wake up" the tumor. Anoxic cells are dependent on anaerobic glucose breakdown for ATP generation. The local extracellular glucose concentration gradient is determined by the blood glucose concentration and by consumption by cells closer to the nearest blood vessel. The blood glucose concentration can be lowered by 20-40% during fasting. We calculated that glucose supply to the potentially hazardous anoxic cells can thereby be reduced significantly, resulting in cell death specifically of the anoxic tumor cells. We hypothesize that intermittent fasting will help to reduce the incidence of tumor relapse via reducing the number of anoxic tumor cells and tumor awakening. PMID:25448890

  1. Tumor suppression function of the Big-h3 gene in radiation carcinogenesis

    NASA Astrophysics Data System (ADS)

    Zhao, Y.; Piao, C.; Hei, T.

    Interaction between cell and extracellular matrix (ECM) plays a crucial role in tumor invasiveness and metastasis. Using an immortalized human bronchial epithelial (BEP2D) cell model, we show here that expression of Big-h3 gene, a secreted adhesion molecule induced by transforming growth factor- beta (TGF-beta ), is markedly decreased in independently generated, high LET radiation-induced tumor cell lines (TL1-TL5) relative to parental BEP2D cells. Expression of this gene was restored to control level in fusion cell lines between the tumorigenic and parental BEP2D cells that were no longer tumorigenic in nude mice. Transfection of Big-h3 gene into tumor cells resulted in a significant reduction of tumor growth. While integrin receptor alpha 5/beta 1 was overexpressed in tumor cells, its expression was corrected to the level of control BEP2D cells after Big-h3 transfection. These data suggest that Big-h3 is involved in tumor progression by regulating integrin receptor alpha 5/beta 1. . WWee We further show that down regulation of Big-h3 results from loss of expression of TGFbeta1 in tumor cells. The findings provide strong evidence that the Big-h3 gene has tumor suppressor function in radiation induced tumorigenic human bronchial epithelial cells and suggest a potential target for interventional therapy.

  2. Bim must be able to engage all pro-survival Bcl-2 family members for efficient tumor suppression

    PubMed Central

    Mérino, D; Strasser, A; Bouillet, P

    2012-01-01

    Over-expression of the transcriptional regulator Myc is thought to be the cause or a contributing factor in the development of a large number of human lymphomas and certain other cancers. Apoptotic cell death constitutes a tumor suppressive mechanism, particularly in the context of Myc over-expression. Accordingly, lymphoma development in Eμ-Myc transgenic mice, which mimic the Myc/IgH chromosomal translocation that causes Burkitt Lymphoma, is accelerated by concomitant over-expression of anti-apoptotic Bcl-2 family members or loss of proapoptotic BH3 only proteins, such as Bim. Bim binds with high affinity to all prosurvival Bcl-2-like proteins and can also interact with Bax/Bak, but it remains unclear which of these interactions are critical for its tumor suppressive function. We have previously generated knock-in mutant mice in which the BH3 region of Bim has been exchanged with that for Bad, Noxa or Puma so that it can only bind to select pro-survival Bcl-2-like proteins: BimBad binding to Bcl-2, Bcl-xL and Bcl-w but not Mcl-1 or A1; BimNoxa binding only to Mcl-1 and A1 and as a control, BimPuma, which can still bind all pro-survival Bcl-2-like proteins. We have now inter-crossed these Bim mutant mice with Eμ-Myc transgenic mice and found that both the BimBad and the BimNoxa mutations but not the BimPuma mutation greatly accelerate Myc-induced lymphoma development and increase leukemic burden. These results demonstrate that for optimal tumor suppressive activity, Bim must be able to interact with all and not just select pro-survival Bcl-2 family members. PMID:22081075

  3. 1′-Acetoxychavicol acetate suppresses angiogenesis-mediated human prostate tumor growth by targeting VEGF-mediated Src-FAK-Rho GTPase-signaling pathway

    PubMed Central

    Pang, Xiufeng; Zhang, Li; Lai, Li; Chen, Jing; Wu, Yuanyuan; Yi, Zhengfang; Zhang, Jian; Qu, Weijing; Aggarwal, Bharat B.; Liu, Mingyao

    2011-01-01

    Cancer therapeutic agents that are safe, effective and affordable are urgently needed. We describe that 1′-acetoxychavicol acetate (ACA), a component of Siamese ginger (Languas galanga), can suppress prostate tumor growth by largely abrogating angiogenesis. ACA suppressed vascular endothelial growth factor (VEGF)-induced proliferation, migration, adhesion and tubulogenesis of primary cultured human umbilical vascular endothelial cells (HUVECs) in a dose-dependent manner. ACA also inhibited VEGF-induced microvessel sprouting from aortic rings ex vivo and suppressed new vasculature formation in Matrigel plugs in vivo. We further demonstrated that the mechanisms of this chavicol were to block the activation of VEGF-mediated Src kinase, focal adhesion kinase (FAK) and Rho family of small guanosine triphosphatases (GTPases) (Rac1 and Cdc42 but not RhoA) in HUVECs. Furthermore, treatment of human prostate cancer cells (PC-3) with ACA resulted in decreased cell viability and suppression of angiogenic factor production by interference with dual Src/FAK kinases. After subcutaneous administration to mice bearing human prostate cancer PC-3 xenografts, ACA (6 mg/kg/day) remarkably inhibited tumor volume and tumor weight and decreased levels of Src, CD31, VEGF and Ki-67. As indicated by immunohistochemistry and TUNEL analysis, microvessel density and cell proliferation were also dramatically suppressed in tumors from ACA-treated mice. Taken together, our findings suggest that ACA targets the Src-FAK-Rho GTPase pathway, leading to the suppression of prostate tumor angiogenesis and growth. PMID:21427164

  4. 1'-Acetoxychavicol acetate suppresses angiogenesis-mediated human prostate tumor growth by targeting VEGF-mediated Src-FAK-Rho GTPase-signaling pathway.

    PubMed

    Pang, Xiufeng; Zhang, Li; Lai, Li; Chen, Jing; Wu, Yuanyuan; Yi, Zhengfang; Zhang, Jian; Qu, Weijing; Aggarwal, Bharat B; Liu, Mingyao

    2011-06-01

    Cancer therapeutic agents that are safe, effective and affordable are urgently needed. We describe that 1'-acetoxychavicol acetate (ACA), a component of Siamese ginger (Languas galanga), can suppress prostate tumor growth by largely abrogating angiogenesis. ACA suppressed vascular endothelial growth factor (VEGF)-induced proliferation, migration, adhesion and tubulogenesis of primary cultured human umbilical vascular endothelial cells (HUVECs) in a dose-dependent manner. ACA also inhibited VEGF-induced microvessel sprouting from aortic rings ex vivo and suppressed new vasculature formation in Matrigel plugs in vivo. We further demonstrated that the mechanisms of this chavicol were to block the activation of VEGF-mediated Src kinase, focal adhesion kinase (FAK) and Rho family of small guanosine triphosphatases (GTPases) (Rac1 and Cdc42 but not RhoA) in HUVECs. Furthermore, treatment of human prostate cancer cells (PC-3) with ACA resulted in decreased cell viability and suppression of angiogenic factor production by interference with dual Src/FAK kinases. After subcutaneous administration to mice bearing human prostate cancer PC-3 xenografts, ACA (6 mg/kg/day) remarkably inhibited tumor volume and tumor weight and decreased levels of Src, CD31, VEGF and Ki-67. As indicated by immunohistochemistry and TUNEL analysis, microvessel density and cell proliferation were also dramatically suppressed in tumors from ACA-treated mice. Taken together, our findings suggest that ACA targets the Src-FAK-Rho GTPase pathway, leading to the suppression of prostate tumor angiogenesis and growth.

  5. PTBP1-associated microRNA-1 and -133b suppress the Warburg effect in colorectal tumors

    PubMed Central

    Taniguchi, Kohei; Sakai, Miku; Sugito, Nobuhiko; Kumazaki, Minami; Shinohara, Haruka; Yamada, Nami; Nakayama, Tatsushi; Ueda, Hiroshi; Nakagawa, Yoshihito; Ito, Yuko; Futamura, Manabu; Uno, Bunji; Otsuki, Yoshinori; Yoshida, Kazuhiro; Uchiyama, Kazuhisa; Akao, Yukihiro

    2016-01-01

    It is known that pyruvate kinase in muscle (PKM), which is a rate-limiting glycolytic enzyme, has essential roles in the Warburg effect and that expression of cancer-dominant PKM2 is increased by polypyrimidine tract-binding protein 1 (PTBP1), which is a splicer of the PKM gene. In other words, PKM2 acts as a promoter of the Warburg effect. Previously, we demonstrated that the Warburg effect was partially established by down-regulation of several microRNAs (miRs) that bind to PTBP1 and that ectopic expression of these miRs suppressed the Warburg effect. In this study, we investigated the functions of miR-1 and -133b, which are well known as muscle-specific miRs, from the viewpoint of the Warburg effect in colorectal tumors. The expression levels of miR-1 and -133b were relatively high in colon tissue except muscle and very frequently down-regulated in 75 clinical colorectal tumors samples, even in adenomas, compared with those of the adjacent normal tissue samples. The ectopic expression of these miRs induced growth suppression and autophagic cell death through the switching of PKM isoform expression from PKM2 to PKM1 by silencing PTBP1 expression both in vitro and in vivo. Also, we showed that the resultant increase in the intracellular level of reactive oxygen species (ROS) was involved in this mechanism. Furthermore, PTBP1 was highly expressed in most of the 30 clinical colorectal tumor samples examined, even in adenomas. Our results suggested that PTBP1 and PTBP1-associated miR-1 and -133b are crucial molecules for the maintenance of the Warburg effect in colorectal tumors. PMID:26980745

  6. A novel Hsp90 inhibitor AT13387 induces senescence in EBV-positive nasopharyngeal carcinoma cells and suppresses tumor formation

    PubMed Central

    2013-01-01

    Background Nasopharyngeal carcinoma (NPC) is an epithelial malignancy strongly associated with Epstein-Barr virus (EBV). AT13387 is a novel heat shock protein 90 (Hsp90) inhibitor, which inhibits the chaperone function of Hsp90 and reduces expression of Hsp90-dependent client oncoproteins. This study aimed to evaluate both the in vitro and in vivo antitumor effects of AT13387 in the EBV-positive NPC cell line C666-1. Results Our results showed that AT13387 inhibited C666-1 cell growth and induced cellular senescence with the downregulation of multiple Hsp90 client oncoproteins EGFR, AKT, CDK4, and restored the protein expression of negative cell cycle regulator p27. We also studied the ability of AT13387 to restore p27 expression by downregulation of AKT and the p27 ubiquitin mediator, Skp2, using AKT inhibitor and Skp2 siRNA. In the functional study, AT13387 inhibited cell migration with downregulation of a cell migration regulator, HDAC6, and increased the acetylation and stabilization of α-tubulin. We also examined the effect of AT13387 on putative cancer stem cells (CSC) by 3-D tumor sphere formation assay. AT13387 effectively reduced both the number and size of C666-1 tumor spheres with decreased expression of NPC CSC-like markers CD44 and SOX2. In the in vivo study, AT13387 significantly suppressed tumor formation in C666-1 NPC xenografts. Conclusion AT13387 suppressed cell growth, cell migration, tumor sphere formation and induced cellular senescence on EBV-positive NPC cell line C666-1. Also, the antitumor effect of AT13387 was demonstrated in an in vivo model. This study provided experimental evidence for the preclinical value of using AT13387 as an effective antitumor agent in treatment of NPC. PMID:24156782

  7. EF24 inhibits tumor growth and metastasis via suppressing NF-kappaB dependent pathways in human cholangiocarcinoma

    PubMed Central

    Yin, Da-long; Liang, Ying-jian; Zheng, Tong-sen; Song, Rui-peng; Wang, Jia-bei; Sun, Bo-shi; Pan, Shang-ha; Qu, Lian-dong; Liu, Jia-ren; Jiang, Hong-chi; Liu, Lian-xin

    2016-01-01

    A synthetic monoketone analog of curcumin, termed 3, 5-bis (2-flurobenzylidene) piperidin-4-one (EF24), has been reported to inhibit the growth of a variety of cancer cells both in vitro and in vivo. However, whether EF24 has anticancer effects on cholangiocarcinoma (CCA) cells and the mechanisms remain to be investigated. The aim of our study was to evaluate the molecular mechanisms underlying the anticancer effects of EF24 on CCA tumor growth and metastasis. Cell proliferation, apoptosis, migration, invasion, tumorigenesis and metastasis were examined. EF24 exhibited time- and dose-dependent inhibitory effects on HuCCT-1, TFK-1 and HuH28 human CCA cell lines. EF24 inhibited CCA cell proliferation, migration, and induced G2/M phase arrest. EF24 induced cell apoptosis along with negative regulation of NF-κB- X-linked inhibitor of apoptosis protein (XIAP) signaling pathway. XIAP inhibition by lentivirus mediated RNA interference enhanced EF24-induced apoptosis, while XIAP overexpression reduced it in CCA cells. In vivo, EF24 significantly suppressed the growth of CCA tumor xenografts and tumor metastasis while displaying low toxicity levels. Our findings indicate that EF24 is a potent antitumor agent that inhibits tumor growth and metastasis by inhibiting NF-κB dependent signaling pathways. EF24 may represent a novel approach for CCA treatment. PMID:27571770

  8. Mesenchymal stem cells with Sirt1 overexpression suppress breast tumor growth via chemokine-dependent natural killer cells recruitment

    PubMed Central

    Yu, Yang; Liu, Yan; Zong, Chen; Yu, Qingbo; Yang, Xue; Liang, Lei; Ye, Fei; Nong, Li; Jia, Yuxian; Lu, Yongkui; Han, Zhipeng

    2016-01-01

    Mesenchymal stem cells (MSCs) are generally used in regenerative medicine, tissue engineering and therapy for immune disorder diseases. However, due to the immunosuppressive function of MSCs, the application of MSCs in breast cancer therapy remains limited. Sirt1 is the closest mammalian homologue of the yeast enzyme Sir2 which has an established capacity to influence yeast replicative lifespan. In this study, we demonstrated the effect of MSCs with Sirt1 overexpression (MSCs-Sirt1) in mice bearing 4T1 breast cancer and investigated the underlying mechanism. Firstly, we found that MSCs could accelerate breast tumor growth with promoted proliferation and inhibited apoptosis, whereas MSCs-Sirt1 significantly suppressed tumor growth with proliferation inhibition and apoptosis promotion. Moreover, we detected that NK cells were the prominent antitumor effectors for the MSCs-Sirt1-induced antitumor activity. Besides that, CXCL10 and IFN-γ showed the high level expression in MSCs-Sirt1 treatment group. The impulsive effect of MSCs-Sirt1 on 4T1 cells in vivo could be reversed by inhibition of CXCL10 and IFN-γ. Overall, our results suggest that MSCs-Sirt1 can effectively inhibit breast tumor growth via the recruitment of NK cells in tumor inflammatory microenvironment. PMID:27782173

  9. Down-regulation of tumor endothelial marker 8 suppresses cell proliferation mediated by ERK1/2 activity

    PubMed Central

    Cao, Chuangjie; Wang, Zhuo; Huang, Leilei; Bai, Lihong; Wang, Yuefeng; Liang, Yingjie; Dou, Chengyun; Wang, Liantang

    2016-01-01

    Tumor endothelial marker 8 (TEM8) was recently suggested as a putative anti-tumor target in several types of human cancer based on its selective overexpression in tumor versus normal endothelial cells. The objective of this study was to detect the potential functions of TEM8 in osteosarcoma. Overall, TEM8 was mainly located in cytoplasm and was up-regulated in osteosarcoma compared to benign bone lesions and adjacent non tumor tissue (ANT). High TEM8 expression group had a significant lower overall survival rate than that in the low TEM8 expression group. TEM8 knock-down by siRNA or shRNA results in significant reduction of osteosarcoma cell growth and proliferation both in vitro and in vivo. Ablation of TEM8 led to increasing of p21 and p27 and suppression of cyclin D1 mediated by Erk1/2 activity. These findings suggest that down-regulation of TEM8 play an important role in the inhibition of tumorigenesis and development of osteosarcoma. PMID:26996335

  10. EF24 inhibits tumor growth and metastasis via suppressing NF-kappaB dependent pathways in human cholangiocarcinoma.

    PubMed

    Yin, Da-Long; Liang, Ying-Jian; Zheng, Tong-Sen; Song, Rui-Peng; Wang, Jia-Bei; Sun, Bo-Shi; Pan, Shang-Ha; Qu, Lian-Dong; Liu, Jia-Ren; Jiang, Hong-Chi; Liu, Lian-Xin

    2016-01-01

    A synthetic monoketone analog of curcumin, termed 3, 5-bis (2-flurobenzylidene) piperidin-4-one (EF24), has been reported to inhibit the growth of a variety of cancer cells both in vitro and in vivo. However, whether EF24 has anticancer effects on cholangiocarcinoma (CCA) cells and the mechanisms remain to be investigated. The aim of our study was to evaluate the molecular mechanisms underlying the anticancer effects of EF24 on CCA tumor growth and metastasis. Cell proliferation, apoptosis, migration, invasion, tumorigenesis and metastasis were examined. EF24 exhibited time- and dose-dependent inhibitory effects on HuCCT-1, TFK-1 and HuH28 human CCA cell lines. EF24 inhibited CCA cell proliferation, migration, and induced G2/M phase arrest. EF24 induced cell apoptosis along with negative regulation of NF-κB- X-linked inhibitor of apoptosis protein (XIAP) signaling pathway. XIAP inhibition by lentivirus mediated RNA interference enhanced EF24-induced apoptosis, while XIAP overexpression reduced it in CCA cells. In vivo, EF24 significantly suppressed the growth of CCA tumor xenografts and tumor metastasis while displaying low toxicity levels. Our findings indicate that EF24 is a potent antitumor agent that inhibits tumor growth and metastasis by inhibiting NF-κB dependent signaling pathways. EF24 may represent a novel approach for CCA treatment. PMID:27571770

  11. Deoxypodophyllotoxin suppresses tumor vasculature in HUVECs by promoting cytoskeleton remodeling through LKB1-AMPK dependent Rho A activatio.

    PubMed

    Wang, Yurong; Wang, Bin; Guerram, Mounia; Sun, Li; Shi, Wei; Tian, Chongchong; Zhu, Xiong; Jiang, Zhenzhou; Zhang, Luyong

    2015-10-01

    Angiogenesis plays a critical role in the growth and metastasis of tumors, which makes it an attractive target for anti-tumor drug development. Deoxypodophyllotoxin (DPT), a natural product isolated from Anthriscus sylvestris, inhibits cell proliferation and migration in various cancer cell types. Our previous studies indicate that DPT possesses both anti-angiogenic and vascular-disrupting activities. Although the RhoA/ RhoA kinase (ROCK) signaling pathway is implicated in DPT-stimulated cytoskeleton remodeling and tumor vasculature suppressing, the detailed mechanisms by which DPT mediates these effects are poorly understood. In the current study, we found that DPT promotes cytoskeleton remodeling in human umbilical vein endothelial cells (HUVECs) via stimulation of AMP-activated protein kinase (AMPK) and that this effect is abolished by either treatment with a selective AMPK inhibitor or knockdown. Moreover, the cellular levels of LKB1, a kinase upstream of AMPK, were enhanced following DPT exposure. DPT-induced activation of AMPK in tumor vasculature effect was also verified by transgenic zebrafish (VEGFR2:GFP), Matrigel plug assay, and xenograft model in nude mice. The present findings may lay the groundwork for a novel therapeutic approach in treating cancer. PMID:26470595

  12. High PD-1 expression and suppressed cytokine signaling distinguish T cells infiltrating follicular lymphoma tumors from peripheral T cells

    PubMed Central

    Myklebust, June H.; Irish, Jonathan M.; Brody, Joshua; Czerwinski, Debra K.; Houot, Roch; Kohrt, Holbrook E.; Timmerman, John; Said, Jonathan; Green, Michael R.; Delabie, Jan; Kolstad, Arne; Alizadeh, Ash A.

    2013-01-01

    Defects in T-cell function in patients with cancer might influence their capacity to mount efficient antitumor immune responses. Here, we identified highly reduced IL-4–, IL-10–, and IL-21–induced phosphorylation of STAT6 and STAT3 in tumor-infiltrating T cells (TILs) in follicular lymphoma (FL) tumors, contrasting other non-Hodgkin lymphoma TILs. By combining phospho-protein–specific flow cytometry with several T-cell markers, we identified that CD4+CD45RO+CD62L− FL TILs were largely nonresponsive to cytokines, in contrast to the corresponding autologous peripheral blood subset. We observed differential expression of the inhibitory receptor PD-1 in FL TILs and peripheral blood T cells. Furthermore, CD4+PD-1hi FL TILs, containing TFH and non-TFH cells, had lost their cytokine responsiveness, whereas PD-1− TILs had normal cytokine signaling. However, this phenomenon was not tumor specific, because tonsil T cells were similar to FL TILs. FL tumor cells were negative for PD-1 ligands, but PD-L1+ histiocytes were found within the T cell–rich zone of the neoplastic follicles. Disruption of the microenvironment and in vitro culture of FL TILs could restore cytokine signaling in the PD-1hi subset. Because FL TILs in vivo probably receive suppressive signals through PD-1, this provides a rationale for testing PD-1 Ab in combination with immunotherapy in patients with FL. PMID:23297127

  13. Genetic delivery of the murine equivalent of bevacizumab (avastin), an anti-vascular endothelial growth factor monoclonal antibody, to suppress growth of human tumors in immunodeficient mice.

    PubMed

    Watanabe, Masaki; Boyer, Julie L; Hackett, Neil R; Qiu, Jianping; Crystal, Ronald G

    2008-03-01

    Vascular endothelial growth factor (VEGF) produced by tumor cells plays a central role in stimulating angiogenesis required for solid tumor growth. VEGF-specific antibodies inhibit tumor cell line growth in animal models and a humanized monoclonal anti-VEGF antibody (bevacizumab [Avastin]) is approved as a treatment for metastatic cancer. We hypothesized that administration of an adenoviral (Ad) vector expressing the murine monoclonal antibody equivalent of bevacizumab would suppress human tumor growth in vivo. The Ad vector (AdalphaVEGF) encodes the light chain and heavy chain cDNAs of monoclonal antibody A.4.6.1, a murine antibody that specifically recognizes human VEGF with the same antigen-binding site as bevacizumab. AdalphaVEGF efficacy in vivo was evaluated with A-673 rhabdomyosarcoma and DU 145 prostate carcinoma cells in human tumor cell xenografts in SCID mice. For both tumor models, AdalphaVEGF directed the expression of high anti-human VEGF IgG antibody titers in vivo, the numbers of mitotic nuclei and blood vessels in the tumor were significantly decreased (p < 0.05), tumor growth was suppressed (p < 0.05), and there was increased survival (p < 0.005). Thus, AdalphaVEGF, encoding a murine monoclonal antibody that is the equivalent of bevacizumab, effectively suppresses the growth of human tumors, suggesting gene therapy as an alternative to bevacizumab monoclonal antibody therapy.

  14. Biodegradable polymeric micelles encapsulated JK184 suppress tumor growth through inhibiting Hedgehog signaling pathway

    NASA Astrophysics Data System (ADS)

    Zhang, Nannan; Liu, Shichang; Wang, Ning; Deng, Senyi; Song, Linjiang; Wu, Qinjie; Liu, Lei; Su, Weijun; Wei, Yuquan; Xie, Yongmei; Gong, Changyang

    2015-01-01

    JK184 can specially inhibit Gli in the Hedgehog (Hh) pathway, which showed great promise for cancer therapeutics. For developing aqueous formulation and improving anti-tumor activity of JK184, we prepared JK184 encapsulated MPEG-PCL micelles by the solid dispersion method without using surfactants or toxic organic solvents. The cytotoxicity and cellular uptake of JK184 micelles were both increased compared with the free drug. JK184 micelles induced more apoptosis and blocked proliferation of Panc-1 and BxPC-3 tumor cells. In addition, JK184 micelles exerted a sustained in vitro release behavior and had a stronger inhibitory effect on proliferation, migration and invasion of HUVECs than free JK184. Furthermore, JK184 micelles had stronger tumor growth inhibiting effects in subcutaneous Panc-1 and BxPC-3 tumor models. Histological analysis showed that JK184 micelles improved anti-tumor activity by inducing more apoptosis, decreasing microvessel density and reducing expression of CD31, Ki67, and VEGF in tumor tissues. JK184 micelles showed a stronger inhibition of Gli expression in Hh signaling, which played an important role in pancreatic carcinoma. Furthermore, circulation time of JK184 in blood was prolonged after entrapment in polymeric micelles. Our results suggested that JK184 micelles are a promising drug candidate for treating pancreatic tumors with a highly inhibitory effect on Hh activity.JK184 can specially inhibit Gli in the Hedgehog (Hh) pathway, which showed great promise for cancer therapeutics. For developing aqueous formulation and improving anti-tumor activity of JK184, we prepared JK184 encapsulated MPEG-PCL micelles by the solid dispersion method without using surfactants or toxic organic solvents. The cytotoxicity and cellular uptake of JK184 micelles were both increased compared with the free drug. JK184 micelles induced more apoptosis and blocked proliferation of Panc-1 and BxPC-3 tumor cells. In addition, JK184 micelles exerted a sustained in

  15. Controlled release microspheres loaded with BMP7 suppress primary tumors from human glioblastoma.

    PubMed

    González-Gómez, Pilar; Crecente-Campo, Jose; Zahonero, Cristina; de la Fuente, Maria; Hernández-Laín, Aurelio; Mira, Helena; Sánchez-Gómez, Pilar; Garcia-Fuentes, Marcos

    2015-05-10

    Glioblastoma tumor initiating cells are believed to be the main drivers behind tumor recurrence, and therefore therapies that specifically manage this population are of great medical interest. In a previous work, we synthesized controlled release microspheres optimized for intracranial delivery of BMP7, and showed that these devices are able to stop the in vitro growth of a glioma cell line. Towards the translational development of this technology, we now explore these microspheres in further detail and characterize the mechanism of action and the in vivo therapeutic potential using tumor models relevant for the clinical setting: human primary glioblastoma cell lines. Our results show that BMP7 can stop the proliferation and block the self-renewal capacity of those primary cell lines that express the receptor BMPR1B. BMP7 was encapsulated in poly (lactic-co-glycolic acid) microspheres in the form of a complex with heparin and Tetronic, and the formulation provided effective release for several weeks, a process controlled by carrier degradation. Data from xenografts confirmed reduced and delayed tumor formation for animals treated with BMP7-loaded microspheres. This effect was coincident with the activation of the canonical BMP signaling pathway. Importantly, tumors treated with BMP7-loaded microspheres also showed downregulation of several markers that may be related to a malignant stem cell-like phenotype: CD133(+), Olig2, and GFAPδ. We also observed that tumors treated with BMP7-loaded microspheres showed enhanced expression of cell cycle inhibitors and reduced expression of the proliferation marker PCNA. In summary, BMP7-loaded controlled release microspheres are able to inhibit GBM growth and reduce malignancy markers. We envisage that this kind of selective therapy for tumor initiating cells could have a synergistic effect in combination with conventional cytoreductive therapy (chemo-, radiotherapy) or with immunotherapy.

  16. Controlled release microspheres loaded with BMP7 suppress primary tumors from human glioblastoma.

    PubMed

    González-Gómez, Pilar; Crecente-Campo, Jose; Zahonero, Cristina; de la Fuente, Maria; Hernández-Laín, Aurelio; Mira, Helena; Sánchez-Gómez, Pilar; Garcia-Fuentes, Marcos

    2015-05-10

    Glioblastoma tumor initiating cells are believed to be the main drivers behind tumor recurrence, and therefore therapies that specifically manage this population are of great medical interest. In a previous work, we synthesized controlled release microspheres optimized for intracranial delivery of BMP7, and showed that these devices are able to stop the in vitro growth of a glioma cell line. Towards the translational development of this technology, we now explore these microspheres in further detail and characterize the mechanism of action and the in vivo therapeutic potential using tumor models relevant for the clinical setting: human primary glioblastoma cell lines. Our results show that BMP7 can stop the proliferation and block the self-renewal capacity of those primary cell lines that express the receptor BMPR1B. BMP7 was encapsulated in poly (lactic-co-glycolic acid) microspheres in the form of a complex with heparin and Tetronic, and the formulation provided effective release for several weeks, a process controlled by carrier degradation. Data from xenografts confirmed reduced and delayed tumor formation for animals treated with BMP7-loaded microspheres. This effect was coincident with the activation of the canonical BMP signaling pathway. Importantly, tumors treated with BMP7-loaded microspheres also showed downregulation of several markers that may be related to a malignant stem cell-like phenotype: CD133(+), Olig2, and GFAPδ. We also observed that tumors treated with BMP7-loaded microspheres showed enhanced expression of cell cycle inhibitors and reduced expression of the proliferation marker PCNA. In summary, BMP7-loaded controlled release microspheres are able to inhibit GBM growth and reduce malignancy markers. We envisage that this kind of selective therapy for tumor initiating cells could have a synergistic effect in combination with conventional cytoreductive therapy (chemo-, radiotherapy) or with immunotherapy. PMID:25860932

  17. MiR-125a suppresses tumor growth, invasion and metastasis in cervical cancer by targeting STAT3.

    PubMed

    Fan, Zhongyi; Cui, Hanzhi; Xu, Xiaojie; Lin, Zhi; Zhang, Xuelin; Kang, Lei; Han, Baiyu; Meng, Jing; Yan, Zhifeng; Yan, Xiang; Jiao, Shunchang

    2015-09-22

    MiR-125a has been characterized as a tumor suppressor in several cancers. However, the role of miR-125a in cervical cancer is unknown. In this study, we found the expression of miR-125a was downregulated in cervical cancer patients, and negatively correlated with the tumor size, FIGO stage, and preoperative metastasis. Kaplan-Meier analysis showed that miR-125a expression predicted favorable outcome for cervical cancer patients. Dual luciferase assays identified the STAT3 gene as a novel direct target of miR-125a. Functional studies showed that miR-125a overexpression significantly suppressed the growth, invasion and epithelial-mesenchymal transition (EMT) of cervical cancer cells both in vitro and in vivo via decreasing STAT3 expression. Moreover, miR-125a conferred to G2/M cell cycle arrest, accompanied by inhibition of several G2/M checkpoint proteins. Mechanistically, inactivation of miR-125a during cervical carcinogenesis was caused by HPV suppression of p53 expression. Clinically, STAT3, the expression of which, predicted poorer outcome, was inversely correlated with miR-125a in cervical cancer. These data highlight the importance of miR-125a in the cell proliferation and progression of cervical cancer, and indicate that miR-125a may be a useful therapeutic target for cervical cancer.

  18. Tumor suppressive microRNA-200a inhibits renal cell carcinoma development by directly targeting TGFB2.

    PubMed

    Lu, Ruijing; Ji, Ziliang; Li, Xiaoqing; Qin, Jie; Cui, Guanghui; Chen, Jing; Zhai, Qingna; Zhao, Chunjuan; Zhang, Wei; Yu, Zhendong

    2015-09-01

    A large body of evidence indicates that microRNAs play a critical role in tumor initiation and progression by negatively regulating oncogenes or tumor suppressor genes. Here, we report that the expression of miR-200a was notably downregulated in 45 renal cell carcinoma (RCC) samples. Restoration of miR-200a suppressed cell proliferation, migration, and invasion in two RCC cell lines. Furthermore, we used an epithelial-to-mesenchymal transition PCR array to explore the putative target genes of miR-200a. By performing quantitative real-time PCR, ELISA, and luciferase reporter assays, transforming growth factor beta2 (TGFB2) was validated as a direct target gene of miR-200a. Moreover, siRNA-mediated knockdown of TGFB2 partially phenocopied the effect of miR-200a overexpression. These results suggest that miR-200a suppresses RCC development via directly targeting TGFB2, indicating that miR-200a may present a novel target for diagnostic and therapeutic strategies in RCC.

  19. miR-940 Suppresses Tumor Cell Invasion and Migration via Regulation of CXCR2 in Hepatocellular Carcinoma

    PubMed Central

    Ding, Dong; Zhang, Yaodong; Yang, Renjie; Wang, Xing; Ji, Guwei; Huo, Liqun; Shao, Zicheng

    2016-01-01

    Aim. To investigate the expression of miR-940 in the hepatocellular carcinoma (HCC) and its impact on function and biological mechanism in the HCC cells. Methods. Quantitative RT-PCR analysis was used to quantify miR-940 expression in 46 cases of tissues and cells. Transfection of HCC cell lines was performed by miR-940 mimics; the abilities of invasion and migration were assessed through Transwell array. Western blot represents the alteration in expression of CXCR2 by miR-940 mimics. Results. miR-940 expression was decreased significantly in the HCC tissues and the relevant cell lines. miR-940 upregulation suppressed the invasion and migration of HCC cells in vitro. Furthermore, the CXCR2 was downregulated to suppress invasion and migration after miR-940 mimics. Moreover, decreased miR-940 expression was negatively correlated with Edmondson grade (P = 0.008), tumor microsatellite or multiple tumors (P = 0.04), vascular invasion (P = 0.035), and recurrence and metastasis (P = 0.038). Kaplan-Meier analysis demonstrated that decreased miR-940 expression contributed to poor overall survival (P < 0.05). Conclusions. Our findings present that miR-940 acts as a pivotal adaptor of CXCR2 and its transcription downregulated CXCR2 expression to decrease HCC invasion and migration in vitro. Our study suggests that miR-940 may be a novel poor prognostic biomarker for HCC. PMID:27807540

  20. RNA-binding motif protein 47 inhibits Nrf2 activity to suppress tumor growth in lung adenocarcinoma

    PubMed Central

    Sakurai, T; Isogaya, K; Sakai, S; Morikawa, M; Morishita, Y; Ehata, S; Miyazono, K; Koinuma, D

    2016-01-01

    RNA-binding proteins provide a new layer of posttranscriptional regulation of RNA during cancer progression. We identified RNA-binding motif protein 47 (RBM47) as a target gene of transforming growth factor (TGF)-β in mammary gland epithelial cells (NMuMG cells) that have undergone the epithelial-to-mesenchymal transition. TGF-β repressed RBM47 expression in NMuMG cells and lung cancer cell lines. Expression of RBM47 correlated with good prognosis in patients with lung, breast and gastric cancer. RBM47 suppressed the expression of cell metabolism-related genes, which were the direct targets of nuclear factor erythroid 2-related factor 2 (Nrf2; also known as NFE2L2). RBM47 bound to KEAP1 and Cullin 3 mRNAs, and knockdown of RBM47 inhibited their protein expression, which led to enhanced binding of Nrf2 to target genomic regions. Knockdown of RBM47 also enhanced the expression of some Nrf2 activators, p21/CDKN1A and MafK induced by TGF-β. Both mitochondrial respiration rates and the side population cells in lung cancer cells increased in the absence of RBM47. Our findings, together with the enhanced tumor formation and metastasis of xenografted mice by knockdown of the RBM47 expression, suggested tumor-suppressive roles for RBM47 through the inhibition of Nrf2 activity. PMID:26923328

  1. Stimulatory versus suppressive effects of GM-CSF on tumor progression in multiple cancer types

    PubMed Central

    Hong, In-Sun

    2016-01-01

    Granulocyte-macrophage colony-stimulating factor (GM-CSF, also called CSF-2) is best known for its critical role in immune modulation and hematopoiesis. A large body of experimental evidence indicates that GM-CSF, which is frequently upregulated in multiple types of human cancers, effectively marks cancer cells with a ‘danger flag' for the immune system. In this context, most studies have focused on its function as an immunomodulator, namely its ability to stimulate dendritic cell (DC) maturation and monocyte/macrophage activity. However, recent studies have suggested that GM-CSF also promotes immune-independent tumor progression by supporting tumor microenvironments and stimulating tumor growth and metastasis. Although some studies have suggested that GM-CSF has inhibitory effects on tumor growth and metastasis, an even greater number of studies show that GM-CSF exerts stimulatory effects on tumor progression. In this review, we summarize a number of findings to provide the currently available information regarding the anticancer immune response of GM-CSG. We then discuss the potential roles of GM-CSF in the progression of multiple types of cancer to provide insights into some of the complexities of its clinical applications. PMID:27364892

  2. The human ARF tumor suppressor senses blastema activity and suppresses epimorphic tissue regeneration

    PubMed Central

    Hesse, Robert G; Kouklis, Gayle K; Ahituv, Nadav; Pomerantz, Jason H

    2015-01-01

    The control of proliferation and differentiation by tumor suppressor genes suggests that evolution of divergent tumor suppressor repertoires could influence species’ regenerative capacity. To directly test that premise, we humanized the zebrafish p53 pathway by introducing regulatory and coding sequences of the human tumor suppressor ARF into the zebrafish genome. ARF was dormant during development, in uninjured adult fins, and during wound healing, but was highly expressed in the blastema during epimorphic fin regeneration after amputation. Regenerative, but not developmental signals resulted in binding of zebrafish E2f to the human ARF promoter and activated conserved ARF-dependent Tp53 functions. The context-dependent activation of ARF did not affect growth and development but inhibited regeneration, an unexpected distinct tumor suppressor response to regenerative versus developmental environments. The antagonistic pleiotropic characteristics of ARF as both tumor and regeneration suppressor imply that inducing epimorphic regeneration clinically would require modulation of ARF –p53 axis activation. DOI: http://dx.doi.org/10.7554/eLife.07702.001 PMID:26575287

  3. Co-suppression of vitamin C composite nano-drug carrier and its drug delivery to nidus in tumor cells.

    PubMed

    Liu, H Z; Liu, X M; Liu, X C; Zhang, C Z; Liu, H Q

    2016-01-01

    This study aimed to discuss the co-suppression of vitamin C-contained composite nano-drug carrier and its drug delivery to nidus in tumor cells. Amphiphilic polymers PLA-block-PAAA and block polymer PLA-PEG4000-Maleimide, PLA-block-PAAA and PLA-PEG4000-Maleimide composite nano-micelles were prepared, and, PLA-block-PAAA polymer-coated Nile red nano-micelle, PLA-block-PAA and PLA-PEG4000-Maleimide composite nano-micelles as well as paclitaxel-carrying composite nano-micelle in different molar ratios were given stability tests. Lastly, PLA-block-PAAA and PLA-PEG4000-Maleimide composite nano-micelle cancer cells and paclitaxel-carrying composite nano-micelle cancer cells were given toxicity tests. Stability tests showed that self stability of PLA-block-PAAA (63/8) nano-micelle was not sufficient; the stability was good when the molar ratio of PLA-block-PAAA and PLA-PEG4000-Maleimide composite nano-micelle was 3:1; paclitaxel-carrying composite nano-micelle had good stability within 48 hours; PAAA segment had an inhibiting effect on C6 cancer cells and paclitaxel-carrying composite nano-micelle had a strong inhibiting effect also on tumors. After 24 hours, with the continuous release of paclitaxel, the tumor inhibiting effect of paclitaxel-carrying composite nano-micelle enhanced gradually, and the controlled-release of drugs had continuous inhibiting effect on tumor cells. Therefore, PAAA segment and paclitaxel had time-postponed synergistic effect. In conclusion, vitamin C-contained composite nanometer drug carrier materials can deliver anti-cancer drugs to nidus and thus inhibit tumor cells. PMID:27358123

  4. Co-suppression of vitamin C composite nano-drug carrier and its drug delivery to nidus in tumor cells.

    PubMed

    Liu, H Z; Liu, X M; Liu, X C; Zhang, C Z; Liu, H Q

    2016-01-01

    This study aimed to discuss the co-suppression of vitamin C-contained composite nano-drug carrier and its drug delivery to nidus in tumor cells. Amphiphilic polymers PLA-block-PAAA and block polymer PLA-PEG4000-Maleimide, PLA-block-PAAA and PLA-PEG4000-Maleimide composite nano-micelles were prepared, and, PLA-block-PAAA polymer-coated Nile red nano-micelle, PLA-block-PAA and PLA-PEG4000-Maleimide composite nano-micelles as well as paclitaxel-carrying composite nano-micelle in different molar ratios were given stability tests. Lastly, PLA-block-PAAA and PLA-PEG4000-Maleimide composite nano-micelle cancer cells and paclitaxel-carrying composite nano-micelle cancer cells were given toxicity tests. Stability tests showed that self stability of PLA-block-PAAA (63/8) nano-micelle was not sufficient; the stability was good when the molar ratio of PLA-block-PAAA and PLA-PEG4000-Maleimide composite nano-micelle was 3:1; paclitaxel-carrying composite nano-micelle had good stability within 48 hours; PAAA segment had an inhibiting effect on C6 cancer cells and paclitaxel-carrying composite nano-micelle had a strong inhibiting effect also on tumors. After 24 hours, with the continuous release of paclitaxel, the tumor inhibiting effect of paclitaxel-carrying composite nano-micelle enhanced gradually, and the controlled-release of drugs had continuous inhibiting effect on tumor cells. Therefore, PAAA segment and paclitaxel had time-postponed synergistic effect. In conclusion, vitamin C-contained composite nanometer drug carrier materials can deliver anti-cancer drugs to nidus and thus inhibit tumor cells.

  5. Identification of a Novel Calotropis procera Protein That Can Suppress Tumor Growth in Breast Cancer through the Suppression of NF-κB Pathway

    PubMed Central

    Samy, Ramar Perumal; Rajendran, Peramaiyan; Li, Feng; Anandi, Narayana Moorthy; Stiles, Bradley G.; Ignacimuthu, Savarimuthu; Sethi, Gautam; Chow, Vincent T. K.

    2012-01-01

    Breast cancer is the most common cancer among women. To date, improvements in hormonal and cytotoxic therapies have not yet led to a sustained remission or cure. In the present study, we investigated the in vitro and in vivo antitumor activities of a novel Calotropis procera protein (CP-P) isolated from root bark. CP-P protein inhibited the proliferation and induced apoptosis of breast cancer cells through the suppression of nuclear factor kappaB (NF-kB) activation. CP-P, when administered individually or in combination with cyclophosphamide (CYC, 0.2 mg/kg) to rats with 7, 12-dimethyl benz(a)anthracene (DMBA)-induced breast cancer decreased tumor volume significantly without affecting the body weight. To elucidate the anticancer mechanism of CP-P, antioxidant activities such as superoxide dismutase (SOD), catalase (CAT), glutathione-s-transferase (GST) and non-enzymatic antioxidant - reduced glutathione (GSH), vitamin E and C generation in the breast were analyzed by various assays. SOD, CAT, GST, GSH, vitamin E and C levels were high in combination-treated groups (CP-P+CYC) versus the CYC alone-treated groups. Also, the combination was more effective in down-regulating the expression of NF-kB-regulated gene products (cyclin D1 and Bcl-2) in breast tumor tissues. Our findings indicate that CP-P possesses significant antitumor activity comparable to a commonly used anticancer drug, cyclophosphamide, and may form the basis of a novel therapy for breast cancer. PMID:23284617

  6. Identification of a novel Calotropis procera protein that can suppress tumor growth in breast cancer through the suppression of NF-κB pathway.

    PubMed

    Samy, Ramar Perumal; Rajendran, Peramaiyan; Li, Feng; Anandi, Narayana Moorthy; Stiles, Bradley G; Ignacimuthu, Savarimuthu; Sethi, Gautam; Chow, Vincent T K

    2012-01-01

    Breast cancer is the most common cancer among women. To date, improvements in hormonal and cytotoxic therapies have not yet led to a sustained remission or cure. In the present study, we investigated the in vitro and in vivo antitumor activities of a novel Calotropis procera protein (CP-P) isolated from root bark. CP-P protein inhibited the proliferation and induced apoptosis of breast cancer cells through the suppression of nuclear factor kappaB (NF-kB) activation. CP-P, when administered individually or in combination with cyclophosphamide (CYC, 0.2 mg/kg) to rats with 7, 12-dimethyl benz(a)anthracene (DMBA)-induced breast cancer decreased tumor volume significantly without affecting the body weight. To elucidate the anticancer mechanism of CP-P, antioxidant activities such as superoxide dismutase (SOD), catalase (CAT), glutathione-s-transferase (GST) and non-enzymatic antioxidant - reduced glutathione (GSH), vitamin E and C generation in the breast were analyzed by various assays. SOD, CAT, GST, GSH, vitamin E and C levels were high in combination-treated groups (CP-P+CYC) versus the CYC alone-treated groups. Also, the combination was more effective in down-regulating the expression of NF-kB-regulated gene products (cyclin D1 and Bcl-2) in breast tumor tissues. Our findings indicate that CP-P possesses significant antitumor activity comparable to a commonly used anticancer drug, cyclophosphamide, and may form the basis of a novel therapy for breast cancer. PMID:23284617

  7. Mutant p53 Drives Cancer by Subverting Multiple Tumor Suppression Pathways

    PubMed Central

    Haupt, Sue; Raghu, Dinesh; Haupt, Ygal

    2016-01-01

    The tumor suppressor p53 normally acts as a brake to halt damaged cells from perpetrating their genetic errors into future generations. If p53 is disrupted by mutation, it may not only lose these corrective powers, but counterproductively acquire new capacities that drive cancer. A newly emerging manner in which mutant p53 executes its cancer promoting functions is by harnessing key proteins, which normally partner with its wild type, tumor-inhibiting counterpart. In association with the subverted activities of these protein partners, mutant p53 is empowered to act across multiple fundamental cellular pathways (regulating cell division and metabolism) and corrupt them to become cancer promoting. PMID:26858938

  8. Suppression of HSP27 increases the anti-tumor effects of quercetin in human leukemia U937 cells

    PubMed Central

    CHEN, XI; DONG, XIU-SHUAI; GAO, HAI-YAN; JIANG, YONG-FANG; JIN, YING-LAN; CHANG, YU-YING; CHEN, LI-YAN; WANG, JING-HUA

    2016-01-01

    Quercetin, a natural flavonoid, inhibits the growth of leukemia cells and induces apoptosis. Heat shock protein 27 (HSP27) has been reported to promote the development of leukemia by protecting tumor cells from apoptosis through various mechanisms. The present study investigated the effects of small hairpin (sh)RNA-mediated HSP27 knockdown on the anti-cancer effects of quercetin in U937 human leukemia cells. Cells were transfected with recombinant lentiviral vector pCMV-G-NR-U6-shHSP27 (shHSP27), which expressed shRNA specifically targeting the HSP27 gene, alone or in combination with quercetin. The results showed that shHSP27 and quercetin synergistically inhibited U937 cell proliferation and induced apoptosis by decreasing the Bcl2-to-Bax ratio. Furthermore, this combined treatment significantly suppressed the infiltration of tumor cells and the expression of angiogenesis-associated proteins HIF1α and VEGF. Compared with shHSP27 or quercetin alone, shHSP27 plus quercetin markedly decreased the protein expression of cyclinD1 and thus blocked the cell cycle at G1 phase. The Notch/AKT/mTOR signaling pathway is important in tumor aggressiveness; quercetin plus shHSP27 significantly decreased Notch 1 expression and the phosphorylation levels of the downstream signaling proteins AKT and mTOR. The inhibitory effects of quercetin plus shHSP27 on this pathway may thus have been responsible for the cell cycle arrest, inhibition of proliferations and infiltration as well as enhancement of apoptosis. Therefore, these findings collectively suggested that suppression of HSP27 expression amplified the anti-cancer effects of quercetin in U937 human leukemia cells, and that quercetin in combination with shHSP27 represents a promising therapeutic strategy for human leukemia. PMID:26648539

  9. Aged garlic extract inhibits 1,2-dimethylhydrazine-induced colon tumor development by suppressing cell proliferation.

    PubMed

    Jikihara, Hiroshi; Qi, Guangying; Nozoe, Koichiro; Hirokawa, Mayumi; Sato, Hiromi; Sugihara, Yuka; Shimamoto, Fumio

    2015-03-01

    Garlic and its constituents are reported to have a preventive effect against colorectal cancer in animal models. Aged garlic extract (AGE), which is produced by natural extraction from fresh garlic for more than 10 months in aqueous ethanol, also has reputed chemopreventive effects on colon carcinogenesis, but has never been studied for its effects on colon cancer development. We investigated the antitumor effects of AGE in rats with 1,2-dimethylhydrazine (DMH)-induced carcinogenesis, and the mechanism of AGE in human colon cancer cell proliferation. F344 rats randomly divided into three groups were administered DMH (20 mg/kg weight) subcutaneously once a week for 8 weeks in a basal diet. After the last injection, one group of rats was then moved onto a basal diet containing 3% wt/wt AGE, and rats were sacrificed at 8 or 31 weeks. The number of aberrant crypt foci (ACF), histological type of tumor and proliferative activity of the tumor lesions were analyzed by macroscopic, pathological and immunohistochemical methods. DLD-1 human colon cancer cells were utilized to investigate the effect of AGE on anti-cell proliferation. AGE decreased the number of ACF but had no effect on gross tumor pathology. AGE showed a lower number of adenoma and adenocarcinoma lesions by histological analysis. Immunohistochemical staining indicated that AGE suppressed the proliferative activity in adenoma and adenocarcinoma lesions, but showed no effect on normal colon mucosa. Moreover, we demonstrated that AGE delayed cell cycle progression by downregulating cyclin B1 and cdk1 expression via inactivation of NF-κB in the human colorectal cancer cells but did not induce apoptosis. These findings suggest that AGE has an antitumor effect through suppression of cell proliferation. PMID:25573280

  10. Bypassing tumor-associated immune suppression with recombinant adenovirus constructs expressing membrane bound or secreted GITR-L.

    PubMed

    Calmels, Bastien; Paul, Stéphane; Futin, Nicolas; Ledoux, Catherine; Stoeckel, Fabienne; Acres, Bruce

    2005-02-01

    Recent evidence has resurrected the concept of specialized populations of T lymphocytes that are able to suppress an antigen-specific immune response. T-regulatory cells (T-reg) have been characterized as CD4+ CD25+ T cells. Previous reports describing differential gene expression analysis have shown that the glucocorticoid-induced tumor necrosis family receptor family-related gene (GITR) is upregulated in these cells. Furthermore, antibodies specific for GITR have been shown to inhibit the T-suppressor function of CD4+ CD25+ T-reg. The ligands for both mouse and human GITR have been cloned recently. We have inserted the sequences for natural, membrane-bound GITR-ligand (GITR-L) and a truncated secreted form of GITR-L (GITR-Lsol) into the adenovirus-5 genome. Coculture experiments show that cells infected with Ad-GITR-L and supernatants from cells infected with Ad-GITR-Lsol can increase the proliferation of both CD4+ CD25- and CD8+ T cells in response to anti-CD3 stimulation, in the presence, as well as in the absence, of CD4+ CD25+ T cells. The virus constructs were injected into growing B16 melanoma tumors. Ad-GITR-L was shown to attract infiltration with both CD4+ and CD8+ T cells. Both constructs were shown to inhibit tumor growth. PMID:15472713

  11. PTEN status mediates 2ME2 anti-tumor efficacy in preclinical glioblastoma models: role of HIF1α suppression

    PubMed Central

    Muh, Carrie R.; Joshi, Shweta; Singh, Alok R.; Kesari, Santosh; Durden, Donald L.; Makale, Milan T.

    2013-01-01

    Glioblastoma (GBM) is the most common brain cancer and is highly lethal in both adults and children. 2-methoxyestradiol (2ME2) is a microtubule inhibitor that potently inhibits HIF1α, GBM angiogenesis and tumor growth in preclinical models. In patients, 2ME2 exhibits low toxicity and promising but inconsistent efficacy. Given its preclinical potency and its tolerability in patients, we sought to determine whether 2ME2 therapy could be enhanced by addressing resistance via combination therapy, and with biomarkers to identify responsive glioma subgroups. We demonstrate that the PTEN-PI3K axis regulates HIF1α in glioma models. We utilized isogenic-pairs of glioma cell lines, deficient in PTEN or stably reconstituted with PTEN, to determine the role of PTEN in 2ME2 sensitivity in vitro and in vivo. Chou-Talalay synergy studies reveal significant synergy when a pan-PI3K inhibitor is combined with 2ME2. This synergistic activity was correlated with a synergistic suppression of HIF1α accumulation under hypoxic conditions in glioma models. In vivo, 2ME2 markedly inhibited tumor-induced angiogenesis and significantly reduced tumor growth only in a PTEN reconstituted GBM models in both subcutaneous and orthotopic intracranial mouse models. Collectively, these results: (1) suggest that PTEN status predicts sensitivity to 2ME2 and (2) justify exploration of 2ME2 combined with panPI3K inhibitors for the treatment of this intractable brain cancer. PMID:24162827

  12. Silencing of E2F3 suppresses tumor growth of Her2+ breast cancer cells by restricting mitosis.

    PubMed

    Lee, Miyoung; Oprea-Ilies, Gabriela; Saavedra, Harold I

    2015-11-10

    The E2F transcriptional activators E2F1, E2F2 and E2F3a regulate many important cellular processes, including DNA replication, apoptosis and centrosome duplication. Previously, we demonstrated that silencing E2F1 or E2F3 suppresses centrosome amplification (CA) and chromosome instability (CIN) in Her2+ breast cancer cells without markedly altering proliferation. However, it is unknown whether and how silencing a single E2F activator, E2F3, affects malignancy of human breast cancer cells. Thus, we injected HCC1954 Her2+ breast cancer cells silenced for E2F3 into mammary fat pads of immunodeficient mice and demonstrated that loss of E2F3 retards tumor growth. Surprisingly, silencing of E2F3 led to significant reductions in mitotic indices relative to vector controls, while the percentage of cells undergoing S phase were not affected. Nek2 is a mitotic kinase commonly upregulated in breast cancers and a critical regulator of Cdk4- or E2F-mediated CA. In this report, we found that Nek2 overexpression rescued back the CA caused by silencing of shE2F3. However, the effects of Nek2 overexpression in affecting tumor growth rates of shE2F3 and shE2F3; GFP cells were inconclusive. Taken together, our results indicate that E2F3 silencing decreases mammary tumor growth by reducing percentage of cells undergoing mitosis.

  13. Walker 256 Tumor Growth Suppression by Crotoxin Involves Formyl Peptide Receptors and Lipoxin A4

    PubMed Central

    Brigatte, Patrícia; Faiad, Odair Jorge; Ferreira Nocelli, Roberta Cornélio; Landgraf, Richardt G.; Palma, Mario Sergio; Cury, Yara; Curi, Rui; Sampaio, Sandra Coccuzzo

    2016-01-01

    We investigated the effects of Crotoxin (CTX), the main toxin of South American rattlesnake (Crotalus durissus terrificus) venom, on Walker 256 tumor growth, the pain symptoms associated (hyperalgesia and allodynia), and participation of endogenous lipoxin A4. Treatment with CTX (s.c.), daily, for 5 days reduced tumor growth at the 5th day after injection of Walker 256 carcinoma cells into the plantar surface of adult rat hind paw. This observation was associated with inhibition of new blood vessel formation and decrease in blood vessel diameter. The treatment with CTX raised plasma concentrations of lipoxin A4 and its natural analogue 15-epi-LXA4, an effect mediated by formyl peptide receptors (FPRs). In fact, the treatment with Boc-2, an inhibitor of FPRs, abolished the increase in plasma levels of these mediators triggered by CTX. The blockage of these receptors also abolished the inhibitory action of CTX on tumor growth and blood vessel formation and the decrease in blood vessel diameter. Together, the results herein presented demonstrate that CTX increases plasma concentrations of lipoxin A4 and 15-epi-LXA4, which might inhibit both tumor growth and formation of new vessels via FPRs. PMID:27190493

  14. XAF1 promotes neuroblastoma tumor suppression and is required for KIF1Bβ-mediated apoptosis

    PubMed Central

    Choo, Zhang'e; Lin Koh, Rachel Yu; Wallis, Karin; Wei Koh, Timothy Jia; Kuick, Chik Hong; Sobrado, Veronica; Kenchappa, Rajappa S.; Pheng Loh, Amos Hong; Soh, Shui Yen; Schlisio, Susanne; En Chang, Kenneth Tou; Chen, Zhi Xiong

    2016-01-01

    Neuroblastoma is an aggressive, relapse-prone childhood tumor of the sympathetic nervous system. Current treatment modalities do not fully exploit the genetic basis between the different molecular subtypes and little is known about the targets discovered in recent mutational and genetic studies. Neuroblastomas with poor prognosis are often characterized by 1p36 deletion, containing the kinesin gene KIF1B. Its beta isoform, KIF1Bβ, is required for NGF withdrawal-dependent apoptosis, mediated by the induction of XIAP-associated Factor 1 (XAF1). Here, we showed that XAF1 low expression correlates with poor survival and disease status. KIF1Bβ deletion results in loss of XAF1 expression, suggesting that XAF1 is indeed a downstream target of KIF1Bβ. XAF1 silencing protects from NGF withdrawal and from KIF1Bβ-mediated apoptosis. Overexpression of XAF1 impairs tumor progression whereas knockdown of XAF1 promotes tumor growth, suggesting that XAF1 may be a candidate tumor suppressor in neuroblastoma and its associated pathway may be important for developing future interventions. PMID:27097110

  15. Transcription repressor activity of spleen tyrosine kinase mediates breast tumor suppression

    PubMed Central

    Wang, Lei; Devarajan, Eswaran; He, Jin; Reddy, Sekhar P.; Le Dai, Jia

    2005-01-01

    Spleen tyrosine kinase (SYK) is a candidate tumor suppressor gene in breast. Loss of SYK expression in breast tumors as a result of DNA hypermethylation promotes tumor cell proliferation and invasion and predicts shorter survival of breast cancer patients. We previously reported that, in addition to its well-known cytoplasmic localization, the full length Syk is also present in the nucleus, and that Syk nuclear translocation is a rate-limiting step to determine Syk tumor suppressor function. Here we show that the full-length form of Syk acts as a transcription repressor in the cell nucleus. Ectopic expression of Syk down-regulates the transcription of FRA1 and cyclin D1 oncogenes. This transcription repressing activity of Syk is associated with its binding to members of the histone deacetylase family. Syk interacts with transcription factor Sp1 at the Sp1 DNA-binding site in the FRA1 promoter to repress Sp1-activated FRA1 transcription. Thus, breast tumorigenesis and progression resulting from the loss of SYK are underscored by the de-repression of Sp1-mediated oncogene transcription. PMID:16288017

  16. Phosphoribosylpyrophosphate Synthetase 1 Knockdown Suppresses Tumor Formation of Glioma CD133+ Cells Through Upregulating Cell Apoptosis.

    PubMed

    Li, Chen; Yan, Zhongjie; Cao, Xuhua; Zhang, Xiaowei; Yang, Liang

    2016-10-01

    Relapse is the main cause of mortality in patients with glioblastoma multiforme (GBM). Treatment options involve surgical resection followed by a combination of radiotheraphy and chemotherapy with temozolomide. Several genes and genetic pathways have been identified to contribute to therapeutic resistance, giving rise to recurrence of the malignancy. In the last decades, glioma stem cells (GSCs) with the capacity of self-renewal have been demonstrated to maintain tumor propagation and treatment resistance. Here, we isolated CD133-positive (CD133+) and CD133-negative (CD133-) cells from glioblastoma U98G and U87MG cell lines. The role of phosphoribosylpyrophosphate synthetase 1 (PRPS1), which catalyzes the first step of the synthesis of nucleotide, in proliferation and apoptosis was investigated. We found that PRPS1 had a remarkable effect on cell proliferation and sphere formation in both CD133+ and CD133- cells. Compared to CD133- cells, CD133+ cells exhibited more significant results in cell apoptosis assay. CD133+ T98G and U87MG cells were used in xenograft mouse model of tumor formation. Interestingly, the mice implanted with PRPS1 knockdown T98G or U87MG stem cells exhibited prolonged survival time and reduced tumor volume. By immunostaining caspase-3 in tumor tissues of these mice, we demonstrated that the apoptotic activities in tumor cells were positively correlated to the survival time but negatively correlated to PRPS1 expression. Our results indicate that PRPS1 plays an important role in proliferation and apoptosis in GSCs and provide new clues for potential PRPS1-targeted therapy in GBM treatment. PMID:27343059

  17. The tumor suppressive role of RASSF1A in osteosarcoma through the Wnt signaling pathway.

    PubMed

    Wang, Wei-Guo; Chen, Shi-Jie; He, Jin-Shen; Li, Jing-Song; Zang, Xiao-Fang

    2016-07-01

    Ras-association domain family 1 isoform A (RASSF1A) is a tumor suppressor gene and its expression is lost in numerous types of cancer cells, including primary osteosarcoma cells. However, its functional significance in osteosarcoma has not been well defined. The messenger RNA (mRNA) expression of RASSF1A in osteosarcoma tissues and corresponding non-tumoral tissues was measured by real-time PCR. Overexpression of RASSF1A was established by an adenoviral vector expressing RASSF1A. Cell migration and invasion were analyzed in transwells. Apoptosis and cell cycle were analyzed using flow cytometry. Wnt/β-catenin activity was measured by TCF reporter dual-luciferase assay. Cell viability was measured by MTT assay. Protein expression was detected by Western blot. RASSF1A mRNA expression was significantly lower in osteosarcoma tissues than that in the corresponding non-tumoral tissues. The lowered RASSF1A expression correlated with the clinical severity of osteosarcoma. rAd-RASSF1A injection significantly inhibited the growth of xenograft MNNG/HOS tumors in mice. Overexpression of RASSF1A resulted in significant inhibition of the proliferation, migration, and invasion; induced apoptosis; and arrested cell cycle at G0/G1 phase in both the MNNG/HOS and SaOS2 cells. Overexpression of RASSF1A inhibited the Wnt/β-catenin activity, decreased phosphorylation of Akt/glycogen synthase kinase-3-β (GSK3-β), and increased phosphorylation of mammalian sterile 20-like kinase 1 (MST1). Overexpression of RASSF1A downregulated the cyclin D1, c-Myc, and matrix metalloproteinase-7 (MMP-7) protein levels. RASSF1A functions as a tumor suppressor in osteosarcoma and exerts anti-cancer roles through regulating Akt/GSK-3-Wnt/β-catenin signaling. PMID:26750098

  18. MiR-143 targets CTGF and exerts tumor-suppressing functions in epithelial ovarian cancer.

    PubMed

    Wang, Lufei; He, Jin; Xu, Hongmei; Xu, Longjie; Li, Na

    2016-01-01

    A series of recent studies suggested that miR-143 might involve in the tumorigenesis and metastasis of various cancer types. However, the biological function and underlying mechanisms of miR-143 in human epithelial ovarian carcinoma (EOC) remain unknown. Therefore, this study aimed to investigate the miR-143 expression and its clinical diagnosis significance in patients suffering EOC and to analyze its role and underlying molecular mechanism in EOC. Our result showed that the expression levels of miR-143 were downregulated in EOC tissues and cell lines, was associated with International Federation of Gynaecology and Obstetrics (FIGO) stage, pathological grade and lymph node metastasis (all P < 0.01) . Overexpression of miR-143 significantly inhibited EOC cell proliferation, migration, and invasion. Furthermore, computational algorithm combined with luciferase reporter assays identified connective tissue growth factor (CTGF) as the direct target of miR-143 in EOC cells. The expression level of CTGF was significantly increased in EOC tissues, was inversely correlated with miR-143 expression in clinical EOC tissues. Knockdown of CTGF mimicked the suppression effect induced by miR-143 overexpression. Restoration of CTGF expression partially reversed the suppression effect induced by miR-143 overexpression. These results suggested that miR-143 inhibited EOC cell proliferation, migration, and invasion, at least in part, via suppressing CTGF expression. PMID:27398154

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

    SciTech Connect

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

    2014-02-07

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

  20. MiR-143 targets CTGF and exerts tumor-suppressing functions in epithelial ovarian cancer

    PubMed Central

    Wang, Lufei; He, Jin; Xu, Hongmei; Xu, Longjie; Li, Na

    2016-01-01

    A series of recent studies suggested that miR-143 might involve in the tumorigenesis and metastasis of various cancer types. However, the biological function and underlying mechanisms of miR-143 in human epithelial ovarian carcinoma (EOC) remain unknown. Therefore, this study aimed to investigate the miR-143 expression and its clinical diagnosis significance in patients suffering EOC and to analyze its role and underlying molecular mechanism in EOC. Our result showed that the expression levels of miR-143 were downregulated in EOC tissues and cell lines, was associated with International Federation of Gynaecology and Obstetrics (FIGO) stage, pathological grade and lymph node metastasis (all P < 0.01) . Overexpression of miR-143 significantly inhibited EOC cell proliferation, migration, and invasion. Furthermore, computational algorithm combined with luciferase reporter assays identified connective tissue growth factor (CTGF) as the direct target of miR-143 in EOC cells. The expression level of CTGF was significantly increased in EOC tissues, was inversely correlated with miR-143 expression in clinical EOC tissues. Knockdown of CTGF mimicked the suppression effect induced by miR-143 overexpression. Restoration of CTGF expression partially reversed the suppression effect induced by miR-143 overexpression. These results suggested that miR-143 inhibited EOC cell proliferation, migration, and invasion, at least in part, via suppressing CTGF expression. PMID:27398154

  1. STK11/LKB1 Deficiency Promotes Neutrophil Recruitment and Proinflammatory Cytokine Production to Suppress T-cell Activity in the Lung Tumor Microenvironment.

    PubMed

    Koyama, Shohei; Akbay, Esra A; Li, Yvonne Y; Aref, Amir R; Skoulidis, Ferdinandos; Herter-Sprie, Grit S; Buczkowski, Kevin A; Liu, Yan; Awad, Mark M; Denning, Warren L; Diao, Lixia; Wang, Jing; Parra-Cuentas, Edwin R; Wistuba, Ignacio I; Soucheray, Margaret; Thai, Tran; Asahina, Hajime; Kitajima, Shunsuke; Altabef, Abigail; Cavanaugh, Jillian D; Rhee, Kevin; Gao, Peng; Zhang, Haikuo; Fecci, Peter E; Shimamura, Takeshi; Hellmann, Matthew D; Heymach, John V; Hodi, F Stephen; Freeman, Gordon J; Barbie, David A; Dranoff, Glenn; Hammerman, Peter S; Wong, Kwok-Kin

    2016-03-01

    STK11/LKB1 is among the most commonly inactivated tumor suppressors in non-small cell lung cancer (NSCLC), especially in tumors harboring KRAS mutations. Many oncogenes promote immune escape, undermining the effectiveness of immunotherapies, but it is unclear whether the inactivation of tumor suppressor genes, such as STK11/LKB1, exerts similar effects. In this study, we investigated the consequences of STK11/LKB1 loss on the immune microenvironment in a mouse model of KRAS-driven NSCLC. Genetic ablation of STK11/LKB1 resulted in accumulation of neutrophils with T-cell-suppressive effects, along with a corresponding increase in the expression of T-cell exhaustion markers and tumor-promoting cytokines. The number of tumor-infiltrating lymphocytes was also reduced in LKB1-deficient mouse and human tumors. Furthermore, STK11/LKB1-inactivating mutations were associated with reduced expression of PD-1 ligand PD-L1 in mouse and patient tumors as well as in tumor-derived cell lines. Consistent with these results, PD-1-targeting antibodies were ineffective against Lkb1-deficient tumors. In contrast, treating Lkb1-deficient mice with an IL6-neutralizing antibody or a neutrophil-depleting antibody yielded therapeutic benefits associated with reduced neutrophil accumulation and proinflammatory cytokine expression. Our findings illustrate how tumor suppressor mutations can modulate the immune milieu of the tumor microenvironment, and they offer specific implications for addressing STK11/LKB1-mutated tumors with PD-1-targeting antibody therapies. PMID:26833127

  2. Cycles of transient high-dose cyclophosphamide administration and intratumoral oncolytic adenovirus vector injection for long-term tumor suppression in Syrian hamsters.

    PubMed

    Dhar, D; Toth, K; Wold, W S M

    2014-04-01

    Immune responses against oncolytic adenovirus (Ad) vectors are thought to limit vector anti-tumor efficacy. With Syrian hamsters, which are immunocompetent and whose tumors and normal tissues are permissive for replication of Ad5-based oncolytic Ad vectors, treating with high-dose cyclophosphamide (CP) to suppress the immune system and exert chemotherapeutic effects enhances Ad vector anti-tumor efficacy. However, long-term CP treatment and immunosuppression can lead to anemia and vector spread to normal tissues. Here, we employed three cycles of transient high-dose CP administration plus intratumoral injection of the oncolytic Ad vector VRX-007 followed by withdrawal of CP. Each cycle lasted 4-6 weeks. This protocol allowed the hamsters to remain healthy so the study could be continued for ~100 days. The tumors were very well suppressed throughout the study. With immunocompetent hamsters, the vector retarded tumor growth initially, but after 3-4 weeks the tumors resumed rapid growth and further injections of vector were ineffective. Preimmunization of the hamsters with Ad5 prevented vector spillover from the tumor to the liver yet still allowed for effective long-term anti-tumor efficacy. Our results suggest that a clinical protocol might be developed with cycles of transient chemotherapy plus intratumoral vector injection to achieve significant anti-tumor efficacy while minimizing the side effects of cytostatic treatment.

  3. Local administration of siRNA through Microneedle: Optimization, Bio-distribution, Tumor Suppression and Toxicity.

    PubMed

    Tang, Tao; Deng, Yan; Chen, Jiao; Zhao, Yi; Yue, Ruifeng; Choy, Kwong Wai; Wang, Chi Chiu; Du, Quan; Xu, Yan; Han, Linxiao; Chung, Tony Kwok Hung

    2016-01-01

    Although RNA interference may become a novel therapeutic approach for cancer treatment, target-site accumulation of siRNA to achieve therapeutic dosage will be a major problem. Microneedle represents a better way to deliver siRNAs and we have evaluated for the first time the capability of a silicon microneedle array for delivery of Gapdh siRNA to the skin in vivo and the results showed that the microneedle arrays could effectively deliver siRNA to relevant regions of the skin noninvasively. For the further study in this field, we evaluated the efficacy of the injectable microneedle device for local delivery of siRNA to the mouse xenograft. The results presented here indicate that local administration of siRNA through injectable microneedle could effectively deliver siRNA into the tumor region, and inhibit tumor progression without major adverse effects. PMID:27457182

  4. Claudin-low bladder tumors are immune infiltrated and actively immune suppressed

    PubMed Central

    Kardos, Jordan; Chai, Shengjie; Mose, Lisle E.; Selitsky, Sara R.; Krishnan, Bhavani; Saito, Ryoichi; Iglesia, Michael D.; Milowsky, Matthew I.; Parker, Joel S.; Kim, William Y.; Vincent, Benjamin G.

    2016-01-01

    We report the discovery of a claudin-low molecular subtype of high-grade bladder cancer that shares characteristics with the homonymous subtype of breast cancer. Claudin-low bladder tumors were enriched for multiple genetic features including increased rates of RB1, EP300, and NCOR1 mutations; increased frequency of EGFR amplification; decreased rates of FGFR3, ELF3, and KDM6A mutations; and decreased frequency of PPARG amplification. While claudin-low tumors showed the highest expression of immune gene signatures, they also demonstrated gene expression patterns consistent with those observed in active immunosuppression. This did not appear to be due to differences in predicted neoantigen burden, but rather was associated with broad upregulation of cytokine and chemokine levels from low PPARG activity, allowing unopposed NFKB activity. Taken together, these results define a molecular subtype of bladder cancer with distinct molecular features and an immunologic profile that would, in theory, be primed for immunotherapeutic response.

  5. Local administration of siRNA through Microneedle: Optimization, Bio-distribution, Tumor Suppression and Toxicity

    PubMed Central

    Tang, Tao; Deng, Yan; Chen, Jiao; Zhao, Yi; Yue, Ruifeng; Choy, Kwong Wai; Wang, Chi Chiu; Du, Quan; Xu, Yan; Han, Linxiao; Chung, Tony Kwok Hung

    2016-01-01

    Although RNA interference may become a novel therapeutic approach for cancer treatment, target-site accumulation of siRNA to achieve therapeutic dosage will be a major problem. Microneedle represents a better way to deliver siRNAs and we have evaluated for the first time the capability of a silicon microneedle array for delivery of Gapdh siRNA to the skin in vivo and the results showed that the microneedle arrays could effectively deliver siRNA to relevant regions of the skin noninvasively. For the further study in this field, we evaluated the efficacy of the injectable microneedle device for local delivery of siRNA to the mouse xenograft. The results presented here indicate that local administration of siRNA through injectable microneedle could effectively deliver siRNA into the tumor region, and inhibit tumor progression without major adverse effects. PMID:27457182

  6. Local administration of siRNA through Microneedle: Optimization, Bio-distribution, Tumor Suppression and Toxicity

    NASA Astrophysics Data System (ADS)

    Tang, Tao; Deng, Yan; Chen, Jiao; Zhao, Yi; Yue, Ruifeng; Choy, Kwong Wai; Wang, Chi Chiu; Du, Quan; Xu, Yan; Han, Linxiao; Chung, Tony Kwok Hung

    2016-07-01

    Although RNA interference may become a novel therapeutic approach for cancer treatment, target-site accumulation of siRNA to achieve therapeutic dosage will be a major problem. Microneedle represents a better way to deliver siRNAs and we have evaluated for the first time the capability of a silicon microneedle array for delivery of Gapdh siRNA to the skin in vivo and the results showed that the microneedle arrays could effectively deliver siRNA to relevant regions of the skin noninvasively. For the further study in this field, we evaluated the efficacy of the injectable microneedle device for local delivery of siRNA to the mouse xenograft. The results presented here indicate that local administration of siRNA through injectable microneedle could effectively deliver siRNA into the tumor region, and inhibit tumor progression without major adverse effects.

  7. Claudin-low bladder tumors are immune infiltrated and actively immune suppressed

    PubMed Central

    Kardos, Jordan; Chai, Shengjie; Mose, Lisle E.; Selitsky, Sara R.; Krishnan, Bhavani; Saito, Ryoichi; Iglesia, Michael D.; Milowsky, Matthew I.; Parker, Joel S.; Kim, William Y.; Vincent, Benjamin G.

    2016-01-01

    We report the discovery of a claudin-low molecular subtype of high-grade bladder cancer that shares characteristics with the homonymous subtype of breast cancer. Claudin-low bladder tumors were enriched for multiple genetic features including increased rates of RB1, EP300, and NCOR1 mutations; increased frequency of EGFR amplification; decreased rates of FGFR3, ELF3, and KDM6A mutations; and decreased frequency of PPARG amplification. While claudin-low tumors showed the highest expression of immune gene signatures, they also demonstrated gene expression patterns consistent with those observed in active immunosuppression. This did not appear to be due to differences in predicted neoantigen burden, but rather was associated with broad upregulation of cytokine and chemokine levels from low PPARG activity, allowing unopposed NFKB activity. Taken together, these results define a molecular subtype of bladder cancer with distinct molecular features and an immunologic profile that would, in theory, be primed for immunotherapeutic response. PMID:27699256

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

    PubMed

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

    2012-06-15

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

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

    PubMed

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

    2012-06-15

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

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

    PubMed

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

    2016-02-01

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

  11. Doxifluridine-conjugated 2-5A analog shows strong RNase L activation ability and tumor suppressive effect.

    PubMed

    Kitamura, Yoshiaki; Kito, Seiya; Nakashima, Remi; Tanaka, Katsuki; Nagaoka, Kumi; Kitade, Yukio

    2016-08-15

    RNase L is activated by 2',5'-oligoadenylates (2-5A) at subnanomolar levels to cleave single-stranded RNA. We previously reported the hypothesis that the introduction of an 8-methyladenosine residue at the 2'-terminus of the 2-5A tetramer shifts the 2-5A binding site of RNase L. In this study, we synthesized various 5'-modified 2-5A analogs with 8-methyladenosine at the 2'-terminus. The doxifluridine-conjugated 8-methyladenosine-substituted 2-5A analog was significantly more effective as an activator of RNase L than the parent 5'-monophophorylated 2-5A tetramer and showed a tumor suppressive effect against human cervical cancer cells. PMID:27364610

  12. Monoclonal Antibody and an Antibody-Toxin Conjugate to a Cell Surface Proteoglycan of Melanoma Cells Suppress in vivo Tumor Growth

    NASA Astrophysics Data System (ADS)

    Bumol, T. F.; Wang, Q. C.; Reisfeld, R. A.; Kaplan, N. O.

    1983-01-01

    A monoclonal antibody directed against a cell surface chondroitin sulfate proteoglycan of human melanoma cells, 9.2.27, and its diphtheria toxin A chain (DTA) conjugate were investigated for their effects on in vitro protein synthesis and in vivo tumor growth of human melanoma cells. The 9.2.27 IgG and its DTA conjugate display similar serological activities against melanoma target cells but only the conjugate can induce consistent in vitro inhibition of protein synthesis and toxicity in M21 melanoma cells. However, both 9.2.27 IgG and its DTA conjugate effect significant suppression of M21 tumor growth in vivo in an immunotherapy model of a rapidly growing tumor in athymic nu/nu mice, suggesting that other host mechanisms may mediate monoclonal antibody-induced tumor suppression.

  13. Treatment Combining X-Irradiation and a Ribonucleoside Anticancer Drug, TAS106, Effectively Suppresses the Growth of Tumor Cells Transplanted in Mice

    SciTech Connect

    Yasui, Hironobu; Inanami, Osamu; Asanuma, Taketoshi; Iizuka, Daisuke; Nakajima, Takayuki; Kon, Yasuhiro; Matsuda, Akira; Kuwabara, Mikinori . E-mail: kuwabara@vetmed.hokudai.ac.jp

    2007-05-01

    Purpose: To examine the in vivo antitumor efficacy of X-irradiation combined with administration of a ribonucleoside anticancer drug, 1-(3-C-ethynyl-{beta}-D-ribo-pentofuranosyl)cytosine (TAS106, ECyd), to tumor cell-transplanted mice. Methods and Materials: Colon26 murine rectum adenocarcinoma cells and MKN45 human gastric adenocarcinoma cells were inoculated into the footpad in BALB/c mice and severe combined immunodeficient mice, respectively. They were treated with a relatively low dose of X-irradiation (2 Gy) and low amounts of TAS106 (0.1 mg/kg and 0.5 mg/kg). The tumor growth was monitored by measuring the tumor volume from Day 5 to Day 16 for Colon26 and from Day 7 to Day 20 for MKN45. Histologic analyses for proliferative and apoptotic cells in the tumors were performed using Ki-67 immunohistochemical and terminal deoxynucleotidyl transferase-mediated nick end labeling staining. The expression of survivin, a key molecule related to tumor survival, was assessed by quantitative polymerase chain reaction and immunohistochemical analysis. Results: When X-irradiation and TAS106 treatment were combined, significant inhibition of tumor growth was observed in both types of tumors compared with mice treated with X-irradiation or TAS106 alone. Marked inhibition of tumor growth was observed in half of the mice that received the combined treatment three times at 2-day intervals. Parallel to these phenomena, the suppression of survivin expression and appearance of Ki-67-negative and apoptotic cells were observed. Conclusions: X-irradiation and TAS106 effectively suppress tumor growth in mice. The inhibition of survivin expression by TAS106 is thought to mainly contribute to the suppression of the tumor growth.

  14. Epigenetic inactivation of SPINT2 is associated with tumor suppressive function in esophageal squamous cell carcinoma

    SciTech Connect

    Yue, Dongli; Fan, Qingxia; Chen, Xinfeng; Li, Feng; Wang, Liping; Huang, Lan; Dong, Wenjie; Chen, Xiaoqi; Zhang, Zhen; Liu, Jinyan; Wang, Fei; Wang, Meng; Zhang, Bin [The Biotherapy Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan; The Department of Hematology and others

    2014-03-10

    Hepatocyte growth factor activator inhibitor type 2 (SPINT2), a Kunitz-type serine proteinase inhibitor, has been identified as a putative tumor suppressor gene silenced by promoter methylation. We aimed to investigate whether SPINT2 might act as an esophageal squamous cell carcinoma (ESCC) tumor suppressor gene. Four ESCC cell lines, Fifty-two ESCC tissues and twenty-nine neighboring non-cancerous tissues were included in this study. The expression of SPINT2 was monitored by real time PCR. Bisulfite genomic sequencing and methylation-specific PCR were used to analyze methylation status. The effect of SPINT2 on cell proliferation and apoptosis in EC109 and EC9706 cells was observed by CCK-8 assay and flow cytometric analysis. We found that silencing of SPINT2 was associated with promoter methylation in ESCC cell lines. The densely methylated SPINT2 promoter region was confirmed by bisulfite genomic sequencing. Ectopic expression of SPINT2 inhibited cell proliferation through inducing cell apoptosis in vitro. Furthermore, methylation-specific PCR analysis revealed that SPINT2 promoter methylation was prominent in carcinoma tissues (52.08%) compared with neighboring non-cancerous tissues (22.58%). Kaplan–Meier analysis showed that patients with SPINT2 hypermethylation had shorter survival time. The tumor suppressor gene of SPINT2 is commonly silenced by promoter hypermethylation in human ESCC and SPINT2 hypermethylation is correlated with poor overall survival, implicating SPINT2 is an underlying prognostic marker for human ESCC. - Highlights: • We firstly found SPINT2 gene may be transcriptionally repressed by promoter hypermethylation in ESCC cells. • SPINT2 overexpressing cells induced proliferation inhibition through promoting apoptosis. • mRNA expression of SPINT2 was significantly higher in ESCC tissues than in neighboring non-cancerous tissues. • Promoter hypermethylation of SPINT2 is significantly linked to TNM stage and poor overall survival.

  15. Vitexins, nature-derived lignan compounds, induce apoptosis and suppress tumor growth

    PubMed Central

    Zhou, YingJun; Liu, Yiliang Ellie; Cao, JianGuo; Zeng, GuangYao; Shen, Cui; Li, YanLan; Zhou, MeiChen; Chen, Yiding; Pu, Weiping; Potters, Louis; Shi, Eric Y.

    2009-01-01

    Purpose Lignans such as secoisolariciresinol diglucoside (SDG) in flaxseed, are metabolizes to bioactive mammalian lignans of END and ENL. Because mammalian lignans have chemical structural similarity to the natural estrogen, they are thought to behave like selective estrogen receptor modulators (SERM) and therefore have anticancer effect against hormone-related cancers. We isolated a series of lignan compounds, named as Vitexins, from the seed of Chinese herb Vitex Negundo. Experimental Design We purified several Vitexin lignan compounds. Cytotoxic and antitumor effects were analyzed in cancer cells and in tumor xenograft models. In vivo metabolism of Vitexins was determined in rat. Results Contrasts to the classical lignans, Vitexins were not metabolized to END and ENL. A mixture of Vitexins EVn-50 and purified Vitexin compound VB1 have cytotoxic effect on breast, prostate, and ovarian cancer cells and induces apoptosis with cleavage in PARP protein, up-regulation of Bax, and down-regulation of Bcl-2. This induction of apoptosis seems to be mediated by activation of caspases because inhibition of caspases activity significantly reduced induced apoptosis. We demonstrated a broad antitumor activity of EVn-50 on seven tumor xenograft models including breast, prostate, liver, and cervical cancers. Consistent with in vitro data, EVn-50 treatment induced apoptosis, down-regulated of Bcl-2, and up-regulated Bax in tumor xenografts. Conclusion Vitexin is a class of nature lignan compounds, whose action and anticancer effect is mediated by the mechanisms different from the classical lignans. Vitexin induced antitumor effect and cytotoxic activity is exerted through proapoptotic process, which is mediated by a decreased Bcl-2/Bax ratio and activation of caspases. PMID:19671865

  16. E2f8 mediates tumor suppression in postnatal liver development

    PubMed Central

    Kent, Lindsey N.; Rakijas, Jessica B.; Pandit, Shusil K.; Westendorp, Bart; Chen, Hui-Zi; Huntington, Justin T.; Tang, Xing; Bae, Sooin; Srivastava, Arunima; Senapati, Shantibhusan; Martin, Chelsea K.; Cuitino, Maria C.; Perez, Miguel; Clouse, Julian M.; Chokshi, Veda; Shinde, Neelam; Kladney, Raleigh; Sun, Daokun; Perez-Castro, Antonio; Matondo, Ramadhan B.; Nantasanti, Sathidpak; Mokry, Michal; Machiraju, Raghu; Fernandez, Soledad; Rosol, Thomas J.; Pohar, Kamal S.; Pipas, James M.; Schmidt, Carl R.; de Bruin, Alain

    2016-01-01

    E2F-mediated transcriptional repression of cell cycle–dependent gene expression is critical for the control of cellular proliferation, survival, and development. E2F signaling also interacts with transcriptional programs that are downstream of genetic predictors for cancer development, including hepatocellular carcinoma (HCC). Here, we evaluated the function of the atypical repressor genes E2f7 and E2f8 in adult liver physiology. Using several loss-of-function alleles in mice, we determined that combined deletion of E2f7 and E2f8 in hepatocytes leads to HCC. Temporal-specific ablation strategies revealed that E2f8’s tumor suppressor role is critical during the first 2 weeks of life, which correspond to a highly proliferative stage of postnatal liver development. Disruption of E2F8’s DNA binding activity phenocopied the effects of an E2f8 null allele and led to HCC. Finally, a profile of chromatin occupancy and gene expression in young and tumor-bearing mice identified a set of shared targets for E2F7 and E2F8 whose increased expression during early postnatal liver development is associated with HCC progression in mice. Increased expression of E2F8-specific target genes was also observed in human liver biopsies from HCC patients compared to healthy patients. In summary, these studies suggest that E2F8-mediated transcriptional repression is a critical tumor suppressor mechanism during postnatal liver development. PMID:27454291

  17. Frondoside A Suppressive Effects on Lung Cancer Survival, Tumor Growth, Angiogenesis, Invasion, and Metastasis

    PubMed Central

    Attoub, Samir; Arafat, Kholoud; Gélaude, An; Al Sultan, Mahmood Ahmed; Bracke, Marc; Collin, Peter; Takahashi, Takashi; Adrian, Thomas E.; De Wever, Olivier

    2013-01-01

    A major challenge for oncologists and pharmacologists is to develop less toxic drugs that will improve the survival of lung cancer patients. Frondoside A is a triterpenoid glycoside isolated from the sea cucumber, Cucumaria frondosa and was shown to be a highly safe compound. We investigated the impact of Frondoside A on survival, migration and invasion in vitro, and on tumor growth, metastasis and angiogenesis in vivo alone and in combination with cisplatin. Frondoside A caused concentration-dependent reduction in viability of LNM35, A549, NCI-H460-Luc2, MDA-MB-435, MCF-7, and HepG2 over 24 hours through a caspase 3/7-dependent cell death pathway. The IC50 concentrations (producing half-maximal inhibition) at 24 h were between 1.7 and 2.5 µM of Frondoside A. In addition, Frondoside A induced a time- and concentration-dependent inhibition of cell migration, invasion and angiogenesis in vitro. Frondoside A (0.01 and 1 mg/kg/day i.p. for 25 days) significantly decreased the growth, the angiogenesis and lymph node metastasis of LNM35 tumor xenografts in athymic mice, without obvious toxic side-effects. Frondoside A (0.1–0.5 µM) also significantly prevented basal and bFGF induced angiogenesis in the CAM angiogenesis assay. Moreover, Frondoside A enhanced the inhibition of lung tumor growth induced by the chemotherapeutic agent cisplatin. These findings identify Frondoside A as a promising novel therapeutic agent for lung cancer. PMID:23308143

  18. Tetrandrine inhibits Wnt/β-catenin signaling and suppresses tumor growth of human colorectal cancer.

    PubMed

    He, Bai-Cheng; Gao, Jian-Li; Zhang, Bing-Qiang; Luo, Qing; Shi, Qiong; Kim, Stephanie H; Huang, Enyi; Gao, Yanhong; Yang, Ke; Wagner, Eric R; Wang, Linyuan; Tang, Ni; Luo, Jinyong; Liu, Xing; Li, Mi; Bi, Yang; Shen, Jikun; Luther, Gaurav; Hu, Ning; Zhou, Qixin; Luu, Hue H; Haydon, Rex C; Zhao, Yingming; He, Tong-Chuan

    2011-02-01

    As one of the most common malignancies, colon cancer is initiated by abnormal activation of the Wnt/β-catenin pathway. Although the treatment options have increased for some patients, overall progress has been modest. Thus, there is a great need to develop new treatments. We have found that bisbenzylisoquinoline alkaloid tetrandrine (TET) exhibits anticancer activity. TET is used as a calcium channel blocker to treat hypertensive and arrhythmic conditions in Chinese medicine. Here, we investigate the molecular basis underlying TET's anticancer activity. We compare TET with six chemotherapy drugs in eight cancer lines and find that TET exhibits comparable anticancer activities with camptothecin, vincristine, paclitaxel, and doxorubicin, and better than that of 5-fluorouracil (5-FU) and carboplatin. TET IC₅₀ is ≤5 μM in most of the tested cancer lines. TET exhibits synergistic anticancer activity with 5-FU and reduces migration and invasion capabilities of HCT116 cells. Furthermore, TET induces apoptosis and inhibits xenograft tumor growth of colon cancer. TET treatment leads to a decrease in β-catenin protein level in xenograft tumors, which is confirmed by T-cell factor/lymphocyte enhancer factor and c-Myc reporter assays. It is noteworthy that HCT116 cells with allelic oncogenic β-catenin deleted are less sensitive to TET-mediated inhibition of proliferation, viability, and xenograft tumor growth. Thus, our findings strongly suggest that the anticancer effect of TET in colon cancer may be at least in part mediated by targeting β-catenin activity. Therefore, TET may be used alone or in combination as an effective anticancer agent. PMID:20978119

  19. A Novel Ras Effector Pathway Found to Play Significant Role in Tumor Suppression | Poster

    Cancer.gov

    By Nancy Parrish, Staff Writer; photo by Richard Frederickson, Staff Photographer Normal cells have mechanisms to prevent the development of cancer. Among these is a type of tumor suppressor mechanism known as oncogene-induced senescence, or OIS, which halts the uncontrolled growth of cells caused by mutations in oncogenes. The oncogene Ras plays a crucial role in inducing OIS through a specific cascade of proteins, as reported in a recent article in Molecular and Cellular Biology by Jacqueline Salotti, Ph.D., and colleagues in the Eukaryotic Transcriptional Regulation Section of the Mouse Cancer Genetics Program, Center for Cancer Research (CCR).

  20. miR-181a shows tumor suppressive effect against oral squamous cell carcinoma cells by downregulating K-ras

    SciTech Connect

    Shin, Ki-Hyuk; Bae, Susan D.; Hong, Hannah S.; Kim, Reuben H.; Kang, Mo K.; Park, No-Hee

    2011-01-28

    Research highlights: {yields} MicroRNA-181a (miR-181a) was frequently downregulated in oral squamous cell carcinoma (OSCC). {yields} Overexpression of miR-181a suppressed OSCC growth. {yields} K-ras is a novel target of miR-181a. {yields} Decreased miR-181a expression is attributed to its lower promoter activity in OSCC. -- Abstract: MicroRNAs (miRNAs) are epigenetic regulators of gene expression, and their deregulation plays an important role in human cancer, including oral squamous cell carcinoma (OSCC). Recently, we found that miRNA-181a (miR-181a) was upregulated during replicative senescence of normal human oral keratinocytes. Since senescence is considered as a tumor suppressive mechanism, we thus investigated the expression and biological role of miR-181a in OSCC. We found that miR-181a was frequently downregulated in OSCC. Ectopic expression of miR-181a suppressed proliferation and anchorage independent growth ability of OSCC. Moreover, miR-181a dramatically reduces the growth of OSCC on three dimensional organotypic raft culture. We also identified K-ras as a novel target of miR-181a. miR-181a decreased K-ras protein level as well as the luciferase activity of reporter vectors containing the 3'-untranslated region of K-ras gene. Finally, we defined a minimal regulatory region of miR-181a and found a positive correlation between its promoter activity and the level of miR-181a expression. In conclusion, miR-181a may function as an OSCC suppressor by targeting on K-ras oncogene. Thus, miR-181a should be considered for therapeutic application for OSCC.

  1. LyP-1-conjugated doxorubicin-loaded liposomes suppress lymphatic metastasis by inhibiting lymph node metastases and destroying tumor lymphatics

    NASA Astrophysics Data System (ADS)

    Yan, Zhiqiang; Zhan, Changyou; Wen, Ziyi; Feng, Linglin; Wang, Fei; Liu, Yu; Yang, Xiangkun; Dong, Qing; Liu, Min; Lu, Weiyue

    2011-10-01

    Lymphatic metastasis can be greatly promoted by metastases growth and lymphangiogenesis in lymph nodes (LNs). LyP-1, a cyclic peptide, is able to specifically bind with tumor cells and tumor lymphatics in metastatic LNs. This work aimed to use LyP-1-conjugated liposomes (L-LS) loaded with doxorubicin (DOX) (L-LS/DOX) to suppress lymphatic metastasis by inhibiting both metastases and tumor lymphatics in LNs. L-LS were prepared and exhibited sizes around 90 nm and spherical morphology as characterized by transmission electron microscopy. The in vitro cellular studies showed that LyP-1 modification obviously increased liposome uptake by MDA-MB-435 tumor cells and enhanced the cytotoxicity of liposomal DOX. A popliteal and iliac LN metastases model was successfully established by subcutaneous inoculation of tumor cells to nude mice. The immunofluorescence staining analysis indicated that LyP-1 modification enabled specific binding of liposome with tumor lymphatics and enhanced the destroying effect of liposomal DOX on tumor lymphatics. The in vivo fluorescence imaging and pharmacodynamic studies showed that LyP-1 modification increased liposome uptake by metastatic LNs and that L-LS/DOX significantly decreased metastatic LN growth and LN metastasis rate. These results suggested that L-LS/DOX were an effective delivery system for suppressing lymphatic metastasis by simultaneously inhibiting LN metastases and tumor lymphatics.

  2. Challenge to the suppression of tumor growth by the β4-galactosyltransferase genes

    PubMed Central

    FURUKAWA, Kiyoshi

    2015-01-01

    It has been well established that structural changes in glycans attached to proteins and lipids are associated with malignant transformation of cells. We focused on galactose residues among the sugars since they are involved in the galectin-mediated biology, and many carbohydrate antigens are frequently expressed on this sugar. We found changes in the expression of the β4-galactosyltransferase (β4GalT) 2 and 5 genes in cancer cells: decreased expression of the β4GalT2 gene and increased expression of the β4GalT5 gene. The growth of mouse melanoma cells showing enhanced expression of the β4GalT2 gene or reduced expression of the β4GalT5 gene is inhibited remarkably in syngeneic mice. Tumor growth inhibition is probably caused by the induction of apoptosis, inhibition of angiogenesis, and/or reduced MAPK signals. Direct transduction of human β4GalT2 cDNA together with the adenovirus vector into human hepatocellular carcinoma cells grown in SCID mice results in marked growth retardation of the tumors. β4GalT gene-transfer appears to be a potential tool for cancer therapy. PMID:25743061

  3. A multi-targeted approach to suppress tumor-promoting inflammation.

    PubMed

    Samadi, Abbas K; Bilsland, Alan; Georgakilas, Alexandros G; Amedei, Amedeo; Amin, Amr; Bishayee, Anupam; Azmi, Asfar S; Lokeshwar, Bal L; Grue, Brendan; Panis, Carolina; Boosani, Chandra S; Poudyal, Deepak; Stafforini, Diana M; Bhakta, Dipita; Niccolai, Elena; Guha, Gunjan; Vasantha Rupasinghe, H P; Fujii, Hiromasa; Honoki, Kanya; Mehta, Kapil; Aquilano, Katia; Lowe, Leroy; Hofseth, Lorne J; Ricciardiello, Luigi; Ciriolo, Maria Rosa; Singh, Neetu; Whelan, Richard L; Chaturvedi, Rupesh; Ashraf, S Salman; Shantha Kumara, H M C; Nowsheen, Somaira; Mohammed, Sulma I; Keith, W Nicol; Helferich, William G; Yang, Xujuan

    2015-12-01

    Cancers harbor significant genetic heterogeneity and patterns of relapse following many therapies are due to evolved resistance to treatment. While efforts have been made to combine targeted therapies, significant levels of toxicity have stymied efforts to effectively treat cancer with multi-drug combinations using currently approved therapeutics. We discuss the relationship between tumor-promoting inflammation and cancer as part of a larger effort to develop a broad-spectrum therapeutic approach aimed at a wide range of targets to address this heterogeneity. Specifically, macrophage migration inhibitory factor, cyclooxygenase-2, transcription factor nuclear factor-κB, tumor necrosis factor alpha, inducible nitric oxide synthase, protein kinase B, and CXC chemokines are reviewed as important antiinflammatory targets while curcumin, resveratrol, epigallocatechin gallate, genistein, lycopene, and anthocyanins are reviewed as low-cost, low toxicity means by which these targets might all be reached simultaneously. Future translational work will need to assess the resulting synergies of rationally designed antiinflammatory mixtures (employing low-toxicity constituents), and then combine this with similar approaches targeting the most important pathways across the range of cancer hallmark phenotypes.

  4. The LATS2 tumor suppressor inhibits SREBP and suppresses hepatic cholesterol accumulation

    PubMed Central

    Aylon, Yael; Gershoni, Anat; Rotkopf, Ron; Biton, Inbal E.; Porat, Ziv; Koh, Anna P.; Sun, Xiaochen; Lee, Youngmin; Fiel, Maria-Isabel; Hoshida, Yujin; Friedman, Scott L.; Johnson, Randy L.; Oren, Moshe

    2016-01-01

    The Hippo signaling pathway is a major regulator of organ size. In the liver, Hippo pathway deregulation promotes hyperplasia and hepatocellular carcinoma primarily through hyperactivation of its downstream effector, YAP. The LATS2 tumor suppressor is a core member of the Hippo pathway. A screen for LATS2-interacting proteins in liver-derived cells identified the transcription factor SREBP2, master regulator of cholesterol homeostasis. LATS2 down-regulation caused SREBP activation and accumulation of excessive cholesterol. Likewise, mice harboring liver-specific Lats2 conditional knockout (Lats2-CKO) displayed constitutive SREBP activation and overexpressed SREBP target genes and developed spontaneous fatty liver disease. Interestingly, the impact of LATS2 depletion on SREBP-mediated transcription was clearly distinct from that of YAP overexpression. When challenged with excess dietary cholesterol, Lats2-CKO mice manifested more severe liver damage than wild-type mice. Surprisingly, apoptosis, inflammation, and fibrosis were actually attenuated relative to wild-type mice, in association with impaired p53 activation. Subsequently, Lats2-CKO mice failed to recover effectively from cholesterol-induced damage upon return to a normal diet. Additionally, decreased LATS2 mRNA in association with increased SREBP target gene expression was observed in a subset of human nonalcoholic fatty liver disease cases. Together, these findings further highlight the tight links between tumor suppressors and metabolic homeostasis. PMID:27013235

  5. Smurf E3 ubiquitin ligases at the cross roads of oncogenesis and tumor suppression.

    PubMed

    David, Diana; Nair, S Asha; Pillai, M Radhakrishna

    2013-01-01

    Smad ubiquitin regulatory factors (Smurfs) belong to the HECT- family of E3 ubiquitin ligases and comprise mainly of two members, Smurf1 and Smurf2. Initially, Smurfs have been implicated in determining the competence of cells to respond to TGF-β/BMP signaling pathway. Nevertheless, the intrinsic catalytic activity has extended the repertoire of Smurf substrates beyond the TGF-β/BMP super family expanding its realm further to epigenetic modifications of histones governing the chromatin landscape. Through regulation of a large number of proteins in multiple cellular compartments, Smurfs regulate diverse cellular processes, including cell-cycle progression, cell proliferation, differentiation, DNA damage response, maintenance of genomic stability, and metastasis. As the genomic ablation of Smurfs leads to global changes in histone modifications and predisposition to a wide spectrum of tumors, Smurfs are also considered to have a novel tumor suppressor function. This review focuses on regulation network and biological functions of Smurfs in connection with its role in cancer progression. By providing a portrait of their protein targets, we intend to link the substrate specificity of Smurfs with their contribution to tumorigenesis. Since the regulation and biological functions of Smurfs are quite complex, understanding the oncogenic potential of these E3 ubiquitin ligases may facilitate the development of mechanism-based drugs in cancer treatment.

  6. Type I collagen aging impairs discoidin domain receptor 2-mediated tumor cell growth suppression

    PubMed Central

    Saby, Charles; Buache, Emilie; Brassart-Pasco, Sylvie; El Btaouri, Hassan; Courageot, Marie-Pierre; Van Gulick, Laurence; Garnotel, Roselyne; Jeannesson, Pierre; Morjani, Hamid

    2016-01-01

    Tumor cells are confronted to a type I collagen rich environment which regulates cell proliferation and invasion. Biological aging has been associated with structural changes of type I collagen. Here, we address the effect of collagen aging on cell proliferation in a three-dimensional context (3D). We provide evidence for an inhibitory effect of adult collagen, but not of the old one, on proliferation of human fibrosarcoma HT-1080 cells. This effect involves both the activation of the tyrosine kinase Discoidin Domain Receptor 2 (DDR2) and the tyrosine phosphatase SHP-2. DDR2 and SHP-2 were less activated in old collagen. DDR2 inhibition decreased SHP-2 phosphorylation in adult collagen and increased cell proliferation to a level similar to that observed in old collagen. In the presence of old collagen, a high level of JAK2 and ERK1/2 phosphorylation was observed while expression of the cell cycle negative regulator p21CIP1 was decreased. Inhibition of DDR2 kinase function also led to an increase in ERK1/2 phosphorylation and a decrease in p21CIP1 expression. Similar signaling profile was observed when DDR2 was inhibited in adult collagen. Altogether, these data suggest that biological collagen aging could increase tumor cell proliferation by reducingthe activation of the key matrix sensor DDR2. PMID:27121132

  7. Type I collagen aging impairs discoidin domain receptor 2-mediated tumor cell growth suppression.

    PubMed

    Saby, Charles; Buache, Emilie; Brassart-Pasco, Sylvie; El Btaouri, Hassan; Courageot, Marie-Pierre; Van Gulick, Laurence; Garnotel, Roselyne; Jeannesson, Pierre; Morjani, Hamid

    2016-05-01

    Tumor cells are confronted to a type I collagen rich environment which regulates cell proliferation and invasion. Biological aging has been associated with structural changes of type I collagen. Here, we address the effect of collagen aging on cell proliferation in a three-dimensional context (3D).We provide evidence for an inhibitory effect of adult collagen, but not of the old one, on proliferation of human fibrosarcoma HT-1080 cells. This effect involves both the activation of the tyrosine kinase Discoidin Domain Receptor 2 (DDR2) and the tyrosine phosphatase SHP-2. DDR2 and SHP-2 were less activated in old collagen. DDR2 inhibition decreased SHP-2 phosphorylation in adult collagen and increased cell proliferation to a level similar to that observed in old collagen.In the presence of old collagen, a high level of JAK2 and ERK1/2 phosphorylation was observed while expression of the cell cycle negative regulator p21CIP1 was decreased. Inhibition of DDR2 kinase function also led to an increase in ERK1/2 phosphorylation and a decrease in p21CIP1 expression. Similar signaling profile was observed when DDR2 was inhibited in adult collagen. Altogether, these data suggest that biological collagen aging could increase tumor cell proliferation by reducingthe activation of the key matrix sensor DDR2. PMID:27121132

  8. FGL2 as a Multimodality Regulator of Tumor-Mediated Immune Suppression and Therapeutic Target in Gliomas

    PubMed Central

    Yan, Jun; Kong, Ling-Yuan; Hu, Jiemiao; Gabrusiewicz, Konrad; Dibra, Denada; Xia, Xueqing

    2015-01-01

    Background: Fibrinogen-like protein 2 (FGL2) may promote glioblastoma multiforme (GBM) cancer development by inducing multiple immune-suppression mechanisms. Methods: The biological significance of FGL2 expression was assessed using the The Cancer Genome Atlast (TCGA) glioma database and tumor lysates analysis. The therapeutic effects of an anti-Fgl2 antibody and the role of immune suppression regulation by Fgl2 were determined in immune-competent, NOD-scid IL2Rgammanull (NSG), and FcɣRIIB-/- mice (n = 3–18 per group). Data were analyzed with two-way analysis of variance, log-rank survival analysis, and Pearson correlation. All statistical tests were two-sided. Results: In low-grade gliomas, 72.5% of patients maintained two copies of the FGL2 gene, whereas 83.8% of GBM patients had gene amplification or copy gain. Patients with high levels of FGL2 mRNA in glioma tissues had a lower overall survival (P = .009). Protein levels of FGL2 in GBM lysates were higher relative to low-grade glioma lysates (11.48±5.75ng/mg vs 3.96±1.01ng/mg, P = .003). In GL261 mice treated with an anti-FGL2 antibody, median survival was 27 days compared with only 17 days for mice treated with an isotype control antibody (P = .01). The anti-FGL2 antibody treatment reduced CD39+ Tregs, M2 macrophages, programmed cell death protein 1 (PD-1), and myeloid-derived suppressor cells (MDSCs). FGL2-induced increases in M2, CD39, and PD-1 were ablated in FcɣRIIB-/- mice. Conclusions: FGL2 augments glioma immunosuppression by increasing the expression levels of PD-1 and CD39, expanding the frequency of tumor-supportive M2 macrophages via the FcγRIIB pathway, and enhancing the number of MDSCs and CD39+ regulatory T cells. Collectively, these results show that FGL2 functions as a key immune-suppressive modulator and has potential as an immunotherapeutic target for treating GBM. PMID:25971300

  9. MYC interaction with the tumor suppressive SWI/SNF complex member INI1 regulates transcription and cellular transformation

    PubMed Central

    Stojanova, Angelina; Tu, William B.; Ponzielli, Romina; Kotlyar, Max; Chan, Pak-Kei; Boutros, Paul C.; Khosravi, Fereshteh; Jurisica, Igor; Raught, Brian; Penn, Linda Z.

    2016-01-01

    ABSTRACT MYC is a key driver of cellular transformation and is deregulated in most human cancers. Studies of MYC and its interactors have provided mechanistic insight into its role as a regulator of gene transcription. MYC has been previously linked to chromatin regulation through its interaction with INI1 (SMARCB1/hSNF5/BAF47), a core member of the SWI/SNF chromatin remodeling complex. INI1 is a potent tumor suppressor that is inactivated in several types of cancers, most prominently as the hallmark alteration in pediatric malignant rhabdoid tumors. However, the molecular and functional interaction of MYC and INI1 remains unclear. Here, we characterize the MYC-INI1 interaction in mammalian cells, mapping their minimal binding domains to functionally significant regions of MYC (leucine zipper) and INI1 (repeat motifs), and demonstrating that the interaction does not interfere with MYC-MAX interaction. Protein-protein interaction network analysis expands the MYC-INI1 interaction to the SWI/SNF complex and a larger network of chromatin regulatory complexes. Genome-wide analysis reveals that the DNA-binding regions and target genes of INI1 significantly overlap with those of MYC. In an INI1-deficient rhabdoid tumor system, we observe that with re-expression of INI1, MYC and INI1 bind to common target genes and have opposing effects on gene expression. Functionally, INI1 re-expression suppresses cell proliferation and MYC-potentiated transformation. Our findings thus establish the antagonistic roles of the INI1 and MYC transcriptional regulators in mediating cellular and oncogenic functions. PMID:27267444

  10. MYC interaction with the tumor suppressive SWI/SNF complex member INI1 regulates transcription and cellular transformation.

    PubMed

    Stojanova, Angelina; Tu, William B; Ponzielli, Romina; Kotlyar, Max; Chan, Pak-Kei; Boutros, Paul C; Khosravi, Fereshteh; Jurisica, Igor; Raught, Brian; Penn, Linda Z

    2016-07-01

    MYC is a key driver of cellular transformation and is deregulated in most human cancers. Studies of MYC and its interactors have provided mechanistic insight into its role as a regulator of gene transcription. MYC has been previously linked to chromatin regulation through its interaction with INI1 (SMARCB1/hSNF5/BAF47), a core member of the SWI/SNF chromatin remodeling complex. INI1 is a potent tumor suppressor that is inactivated in several types of cancers, most prominently as the hallmark alteration in pediatric malignant rhabdoid tumors. However, the molecular and functional interaction of MYC and INI1 remains unclear. Here, we characterize the MYC-INI1 interaction in mammalian cells, mapping their minimal binding domains to functionally significant regions of MYC (leucine zipper) and INI1 (repeat motifs), and demonstrating that the interaction does not interfere with MYC-MAX interaction. Protein-protein interaction network analysis expands the MYC-INI1 interaction to the SWI/SNF complex and a larger network of chromatin regulatory complexes. Genome-wide analysis reveals that the DNA-binding regions and target genes of INI1 significantly overlap with those of MYC. In an INI1-deficient rhabdoid tumor system, we observe that with re-expression of INI1, MYC and INI1 bind to common target genes and have opposing effects on gene expression. Functionally, INI1 re-expression suppresses cell proliferation and MYC-potentiated transformation. Our findings thus establish the antagonistic roles of the INI1 and MYC transcriptional regulators in mediating cellular and oncogenic functions. PMID:27267444

  11. Targeting JAK1/STAT3 signaling suppresses tumor progression and metastasis in a peritoneal model of human ovarian cancer.

    PubMed

    Wen, Wei; Liang, Wei; Wu, Jun; Kowolik, Claudia M; Buettner, Ralf; Scuto, Anna; Hsieh, Meng-Yin; Hong, Hao; Brown, Christine E; Forman, Stephen J; Horne, David; Morgan, Robert; Wakabayashi, Mark; Dellinger, Thanh H; Han, Ernest S; Yim, John H; Jove, Richard

    2014-12-01

    JAK/STAT3 is one of the major signaling pathways that is aberrantly activated in ovarian cancer and associated with tumor progression and poor prognosis in patients with ovarian cancer. In this study, we evaluated the therapeutic potential of targeting JAK/STAT3 signaling in ovarian cancer using a peritoneal dissemination mouse model. We developed this mouse model by injecting a metastatic human ovarian cancer cell line, SKOV3-M-Luc, into the peritoneal cavity of immunodeficient mice. This model displayed a phenotype similar to late-stage ovarian cancer, including extensive peritoneal metastasis and ascites production. The constitutive activation of STAT3 in human ovarian cancer cells appeared to be mediated by an autocrine cytokine loop involving the IL6 family of cytokines and JAK1 kinase. shRNA-mediated knockdown of JAK1 or STAT3 in ovarian cancer cells led to reduced tumor growth, decreased peritoneal dissemination, and diminished ascites production, suggesting a critical role of STAT3 in ovarian cancer progression. Similar results were obtained when a small-molecule inhibitor (JAKi) of the JAK1 kinase was used to treat ovarian cancer in this model. In addition, we found that the expression level of IL6 was correlated with activation of STAT3 in ovarian cancer cells both in vitro and in vivo, suggesting a potential application of IL6 as a biomarker. Altogether, our results demonstrate that targeting JAK1/STAT3, using shRNA knockdown or a small-molecule inhibitor, effectively suppressed ovarian tumor progression and, therefore, could be a potential novel therapeutic approach for treating advanced ovarian cancer.

  12. MYC interaction with the tumor suppressive SWI/SNF complex member INI1 regulates transcription and cellular transformation.

    PubMed

    Stojanova, Angelina; Tu, William B; Ponzielli, Romina; Kotlyar, Max; Chan, Pak-Kei; Boutros, Paul C; Khosravi, Fereshteh; Jurisica, Igor; Raught, Brian; Penn, Linda Z

    2016-07-01

    MYC is a key driver of cellular transformation and is deregulated in most human cancers. Studies of MYC and its interactors have provided mechanistic insight into its role as a regulator of gene transcription. MYC has been previously linked to chromatin regulation through its interaction with INI1 (SMARCB1/hSNF5/BAF47), a core member of the SWI/SNF chromatin remodeling complex. INI1 is a potent tumor suppressor that is inactivated in several types of cancers, most prominently as the hallmark alteration in pediatric malignant rhabdoid tumors. However, the molecular and functional interaction of MYC and INI1 remains unclear. Here, we characterize the MYC-INI1 interaction in mammalian cells, mapping their minimal binding domains to functionally significant regions of MYC (leucine zipper) and INI1 (repeat motifs), and demonstrating that the interaction does not interfere with MYC-MAX interaction. Protein-protein interaction network analysis expands the MYC-INI1 interaction to the SWI/SNF complex and a larger network of chromatin regulatory complexes. Genome-wide analysis reveals that the DNA-binding regions and target genes of INI1 significantly overlap with those of MYC. In an INI1-deficient rhabdoid tumor system, we observe that with re-expression of INI1, MYC and INI1 bind to common target genes and have opposing effects on gene expression. Functionally, INI1 re-expression suppresses cell proliferation and MYC-potentiated transformation. Our findings thus establish the antagonistic roles of the INI1 and MYC transcriptional regulators in mediating cellular and oncogenic functions.

  13. Merlin's tumor suppression linked to inhibition of the E3 ubiquitin ligase CRL4DCAF1

    PubMed Central

    Li, Wei

    2010-01-01

    The mechanism by which the FERM domain protein Merlin, encoded by the tumor suppressor NF2, restrains cell proliferation is poorly understood. Prior studies have suggested that Merlin exerts its antimitogenic effect by interacting with multiple signaling proteins located at or near the plasma membrane. We have recently observed that Merlin translocates into the nucleus and binds to and inhibits the E3 ubiquitin ligase CRL4DCAF1. Genetic evidence indicates that inactivation of Merlin induces oncogenic gene expression, hyperproliferation, and tumorigenicity by unleashing the activity of CRL4DCAF1. In addition to providing a potential explanation for the diverse effects that loss of Merlin exerts in multiple cell types, these findings suggest that compounds inhibiting CRL4DCAF1 may display therapeutic efficacy in Neurofibromatosis type 2 and other cancers driven by Merlin inactivation. PMID:21084862

  14. Tumor suppressive function of mir-205 in breast cancer is linked to HMGB3 regulation.

    PubMed

    Elgamal, Ola A; Park, Jong-Kook; Gusev, Yuriy; Azevedo-Pouly, Ana Clara P; Jiang, Jinmai; Roopra, Avtar; Schmittgen, Thomas D

    2013-01-01

    Identifying targets of dysregulated microRNAs (miRNAs) will enhance our understanding of how altered miRNA expression contributes to the malignant phenotype of breast cancer. The expression of miR-205 was reduced in four breast cancer cell lines compared to the normal-like epithelial cell line MCF10A and in tumor and metastatic tissues compared to adjacent benign breast tissue. Two predicted binding sites for miR-205 were identified in the 3' untranslated region of the high mobility group box 3 gene, HMGB3. Both dual-luciferase reporter assay and Western blotting confirmed that miR-205 binds to and regulates HMGB3. To further explore miR-205 targeting of HMGB3, WST-1 proliferation and in vitro invasion assays were performed in MDA-MB-231 and BT549 cells transiently transfected with precursor miR-205 oligonucleotide or HMGB3 small interfering RNA (siRNA). Both treatments reduced the proliferation and invasion of the cancer cells. The mRNA and protein levels of HMGB3 were higher in the tumor compared to adjacent benign specimens and there was an indirect correlation between the expression of HMGB3 mRNA and patient survival. Treatment of breast cancer cells with 5-Aza/TSA derepressed miR-205 and reduced HMGB3 mRNA while knockdown of the transcriptional repressor NRSF/REST, reduced miR-205 and increased HMGB3. In conclusion, regulation of HMGB3 by miR-205 reduced both proliferation and invasion of breast cancer cells. Our findings suggest that modulating miR-205 and/or targeting HMGB3 are potential therapies for advanced breast cancer. PMID:24098490

  15. Knockdown of PKM2 Suppresses Tumor Growth and Invasion in Lung Adenocarcinoma.

    PubMed

    Sun, Hong; Zhu, Anyou; Zhang, Lunjun; Zhang, Jie; Zhong, Zhengrong; Wang, Fengchao

    2015-01-01

    Accumulating evidence shows that activity of the pyruvate kinase M2 (PKM2) isoform is closely related to tumorigenesis. In this study, we investigated the relationship between PKM2 expression, tumor invasion, and the prognosis of patients with lung adenocarcinoma. We retrospectively analyzed 65 cases of patients with lung adenocarcinoma who were divided into low and a high expression groups based on PKM2 immunohistochemical staining. High PKM2 expression was significantly associated with reduced patient survival. We used small interfering RNA (siRNA) technology to investigate the effect of targeted PKM2-knockout on tumor growth at the cellular level. In vitro, siRNA-mediated PKM2-knockdown significantly inhibited the proliferation, glucose uptake (25%), ATP generation (20%) and fatty acid synthesis of A549 cells, while the mitochondrial respiratory capacity of the cells increased (13%).Western blotting analysis showed that PKM2-knockout significantly inhibited the expression of the glucose transporter GLUT1 and ATP citrate lyase, which is critical for fatty acid synthesis. Further Western blotting analysis showed that PKM2-knockdown inhibited the expression of matrix metalloproteinase 2 (MMP-2) and vascular endothelial growth factor (VEGF), which are important in degradation of the extracellular matrix and angiogenesis, respectively. These observations show that PKM2 activates both glycolysis and lipid synthesis, thereby regulating cell proliferation and invasion. This information is important in elucidating the mechanisms by which PKM2 influences the growth and metastasis of lung adenocarcinoma at the cellular and molecular level, thereby providing the basic data required for the development of PKM2-targeted gene therapy.

  16. Transforming growth factor-beta suppresses tumor necrosis factor alpha-induced matrix metalloproteinase-9 expression in monocytes.

    PubMed

    Vaday, G G; Schor, H; Rahat, M A; Lahat, N; Lider, O

    2001-04-01

    The inflammatory response is marked by the release of several cytokines with multiple roles in regulating leukocyte activities, including the secretion of matrix metalloproteinases (MMPs). Although the effects of individual cytokines on monocyte MMP expression have been studied extensively, few studies have examined the influence of combinations of cytokines, which are likely present at inflammatory sites. Herein, we report our investigation of the combinatorial effects of tumor necrosis factor (TNF)-alpha and transforming growth factor (TGF)-beta on MMP-9 synthesis. We found that TGF-beta suppressed TNF-alpha-induced MMP-9 secretion by MonoMac-6 monocytic cells in a dose-dependent manner, with a maximal effect of TGF-beta observed at 1 ng/ml. Such suppression was likely regulated at the pretranslational level, because steady-state mRNA levels of TNF-alpha-induced MMP-9 were reduced by TGF-beta, and pulse-chase radiolabeling also showed a decrease in new MMP-9 protein synthesis. The suppressive effects of TGF-beta were time dependent, because short exposures to TNF-alpha before TGF-beta or simultaneous exposure to both cytokines efficiently reduced MMP-9 secretion. Expression of the tissue inhibitor of metalloproteinases (TIMP)-1 and TNF-alpha receptors was unaffected by either cytokine individually or in combination. Affinity binding with radiolabeled TGF-beta demonstrated that levels of TGF-beta receptors were not increased after preincubation with TGF-beta. Suppression of TNFalpha-induced MMP-9 secretion by TGF-beta correlated with a reduction in prostaglandin E2 (PGE2) secretion. Furthermore, the effect of TGF-beta or indomethacin on blockage of TNF-alpha-stimulated MMP-9 production was reversed by the addition of either exogenous PGE2 or the cyclic AMP (cAMP) analogue Bt2cAMP. Thus, we concluded that TGF-beta acts as a potent suppressor of TNF-alpha-induced monocyte MMP-9 synthesis via a PGE2- and cAMP-dependent mechanism. These results suggest that various

  17. Suppression of β-catenin/TCF transcriptional activity and colon tumor cell growth by dual inhibition of PDE5 and 10

    PubMed Central

    Li, Nan; Chen, Xi; Zhu, Bing; Ramírez-Alcántara, Verónica; Canzoneri, Joshua C.; Lee, Kevin; Sigler, Sara; Gary, Bernard; Li, Yonghe; Zhang, Wei; Moyer, Mary P.; Salter, E. Alan; Wierzbicki, Andrzej; Keeton, Adam B.; Piazza, Gary A.

    2015-01-01

    Previous studies suggest the anti-inflammatory drug, sulindac inhibits tumorigenesis by a COX independent mechanism involving cGMP PDE inhibition. Here we report that the cGMP PDE isozymes, PDE5 and 10, are elevated in colon tumor cells compared with normal colonocytes, and that inhibitors and siRNAs can selectively suppress colon tumor cell growth. Combined treatment with inhibitors or dual knockdown suppresses tumor cell growth to a greater extent than inhibition from either isozyme alone. A novel sulindac derivative, ADT-094 was designed to lack COX-1/-2 inhibitory activity but have improved potency to inhibit PDE5 and 10. ADT-094 displayed >500 fold higher potency to inhibit colon tumor cell growth compared with sulindac by activating cGMP/PKG signaling to suppress proliferation and induce apoptosis. Combined inhibition of PDE5 and 10 by treatment with ADT-094, PDE isozyme-selective inhibitors, or by siRNA knockdown also suppresses β-catenin, TCF transcriptional activity, and the levels of downstream targets, cyclin D1 and survivin. These results suggest that dual inhibition of PDE5 and 10 represents novel strategy for developing potent and selective anticancer drugs. PMID:26299804

  18. Herbal Extract SH003 Suppresses Tumor Growth and Metastasis of MDA-MB-231 Breast Cancer Cells by Inhibiting STAT3-IL-6 Signaling

    PubMed Central

    Woo, Sang-Mi; Park, Sunju; Shin, Yong Cheol; Ko, Seong-Gyu

    2014-01-01

    Cancer inflammation promotes cancer progression, resulting in a high risk of cancer. Here, we demonstrate that our new herbal extract, SH003, suppresses both tumor growth and metastasis of MDA-MB-231 breast cancer cells via inhibiting STAT3-IL-6 signaling path. Our new herbal formula, SH003, mixed extract from Astragalus membranaceus, Angelica gigas, and Trichosanthes kirilowii Maximowicz, suppressed MDA-MB-231 tumor growth and lung metastasis in vivo and reduced the viability and metastatic abilities of MDA-MB-231 cells in vitro. Furthermore, SH003 inhibited STAT3 activation, which resulted in a reduction of IL-6 production. Therefore, we conclude that SH003 suppresses highly metastatic breast cancer growth and metastasis by inhibiting STAT3-IL-6 signaling path. PMID:24976685

  19. MicroRNAs-449a and -449b exhibit tumor suppressive effects in retinoblastoma

    SciTech Connect

    Martin, Alissa; Jones, Aunica; Bryar, Paul J.; Mets, Marilyn; Weinstein, Joanna; Zhang, Gang; Laurie, Nikia A.

    2013-11-01

    Highlights: •We validate miR-449a/b expression in primary human retinoblastomas and cell lines. •Exogenous miRs-449a/b inhibited proliferation in retinoblastoma cell lines. •Exogenous miRs-449a/b increased apoptosis in retinoblastoma cell lines. •miRs-449a/b could serve as viable therapeutic targets for retinoblastoma treatment. -- Abstract: Retinoblastoma is the most common pediatric cancer of the eye. Currently, the chemotherapeutic treatments for retinoblastoma are broad-based drugs such as vincristine, carboplatin, or etoposide. However, therapies targeted directly to aberrant signaling pathways may provide more effective therapy for this disease. The purpose of our study is to illustrate the relationship between the expressions of miRs-449a and -449b to retinoblastoma proliferation and apoptosis. We are the first to confirm an inhibitory effect of miR-449a and -449b in retinoblastoma by demonstrating significantly impaired proliferation and increased apoptosis of tumor cells when these miRNAs are overexpressed. This study suggests that these miRNAs could serve as viable therapeutic targets for retinoblastoma treatment.

  20. Inhibitory effect of α-lipoic acid on thioacetamide-induced tumor promotion through suppression of inflammatory cell responses in a two-stage hepatocarcinogenesis model in rats.

    PubMed

    Fujii, Yuta; Segawa, Risa; Kimura, Masayuki; Wang, Liyun; Ishii, Yuji; Yamamoto, Ryuichi; Morita, Reiko; Mitsumori, Kunitoshi; Shibutani, Makoto

    2013-09-25

    To investigate the protective effect of α-lipoic acid (a-LA) on the hepatocarcinogenic process promoted by thioacetamide (TAA), we used a two-stage liver carcinogenesis model in N-diethylnitrosamine (DEN)-initiated and TAA-promoted rats. We examined the modifying effect of co-administered a-LA on the liver tissue environment surrounding preneoplastic hepatocellular lesions, with particular focus on hepatic macrophages and the mechanism behind the decrease in apoptosis of cells surrounding preneoplastic hepatocellular lesions during the early stages of hepatocellular tumor promotion. TAA increased the number and area of glutathione S-transferase placental form (GST-P)(+) liver cell foci and the numbers of proliferating and apoptotic cells in the liver. Co-administration with a-LA suppressed these effects. TAA also increased the numbers of ED2(+), cyclooxygenase-2(+), and heme oxygenase-1(+) hepatic macrophages as well as the number of CD3(+) lymphocytes. These effects were also suppressed by a-LA. Transcript levels of some inflammation-related genes were upregulated by TAA and downregulated by a-LA in real-time RT-PCR analysis. Outside the GST-P(+) foci, a-LA reduced the numbers of apoptotic cells, active caspase-8(+) cells and death receptor (DR)-5(+) cells. These results suggest that hepatic macrophages producing proinflammatory factors may be activated in TAA-induced tumor promotion. a-LA may suppress tumor-promoting activity by suppressing the activation of these macrophages and the subsequent inflammatory responses. Furthermore, a-LA may suppress tumor-promoting activity by suppressing the DR5-mediated extrinsic pathway of apoptosis and the subsequent regeneration of liver cells outside GST-P(+) foci.

  1. Downregulated MTAP expression in myxofibrosarcoma: A characterization of inactivating mechanisms, tumor suppressive function, and therapeutic relevance

    PubMed Central

    Li, Chien-Feng; Fang, Fu-Min; Kung, Hsing-Jien; Chen, Li-Tzong; Wang, Jun-Wen; Tsai, Jen-Wei; Yu, Shih Chen; Wang, Yu-Hui; Li, Shau-Hsuan; Huang, Hsuan-Ying

    2014-01-01

    Myxofibrosarcomas are genetically complex and involve recurrently deleted chromosome 9p, for which we characterized the pathogenically relevant target(s) using genomic profiling. In 12 of the 15 samples, we detected complete or partial losses of 9p. The only aggressiveness-associated, differentially lost region was 9p21.3, spanning the potential inactivated methylthioadenosine phosphorylase (MTAP) that exhibited homozygous (4/15) or hemizygous (3/15) deletions. In independent samples, MTAP gene status was assessed using quantitative- and methylation-specific PCR assays, and immunoexpression was evaluated. We applied MTAP reexpression or knockdown to elucidate the functional roles of MTAP and the therapeutic potential of L-alanosine in MTAP-preserved and MTAP-deficient myxofibrosarcoma cell lines and xenografts. MTAP protein deficiency (37%) was associated with MTAP gene inactivation (P < 0.001) by homozygous deletion or promoter methylation, and independently portended unfavorable metastasis-free survival (P = 0.0318) and disease-specific survival (P = 0.014). Among the MTAP-deficient cases, the homozygous deletion of MTAP predicted adverse outcome. In MTAP-deficient cells, MTAP reexpression inhibited cell migration and invasion, proliferation, and anchorage-independent colony formation and downregulated cyclin D1. This approach also attenuated the tube-forming abilities of human umbilical venous endothelial cells, attributable to the transcriptional repression of MMP-9, and abrogated the susceptibility to L-alanosine. The inhibiting effects of MTAP expression on tumor growth, angiogenesis, and the induction of apoptosis by L-alanosine were validated using MTAP-reexpressing xenografts and reverted using RNA interference in MTAP-preserved cells. In conclusion, homozygous deletion primarily accounts for the adverse prognostic impact of MTAP deficiency and confers the biological aggressiveness and susceptibility to L-alanosine in myxofibrosarcomas. PMID:25426549

  2. XR5967, a novel modulator of plasminogen activator inhibitor-1 activity, suppresses tumor cell invasion and angiogenesis in vitro.

    PubMed

    Brooks, Teresa D; Wang, Shouming W; Brünner, Nils; Charlton, Peter A

    2004-01-01

    Recent reports suggest that elevated levels of plasminogen activator inhibitor (PAI)-1 may contribute to tumor progression. We have recently shown that antibodies to PAI-1 block the invasive and migratory potential of human fibrosarcoma cells and suppress angiogenesis in vitro. Here we report the in vitro evaluation of a low-molecular-weight modulator of PAI-1, XR5967, on invasion, migration and angiogenesis. XR5967, a diketopiperazine, dose-dependently inhibited the activity of human and murine PAI-1, towards urokinase plasminogen activator (uPA), with IC50 values of 800 nM and 8.3 microM, respectively. This was confirmed by SDS-PAGE, revealing that XR5967 inhibited complex formation between PAI-1 and uPA. This suppression may be caused by XR5967 promoting insertion of the reactive center loop within PAI-1. XR5967 dose-dependently inhibited the invasion of human HT1080 fibrosarcoma cells through Matrigel. Their invasion was reduced by 57% (p<0.001) at 5 microM. HT1080 cell migration was inhibited in a similar manner, indicating that PAI-1 may play an additional role in invasion, which is distinct to its role in the regulation of proteolysis. The potential of XR5967 to inhibit the invasion/migration of human endothelial cells was investigated in an in vitro model of angiogenesis. In this model XR5967 reduced tubule formation by 77% at 5 microM (p<0.001), highlighting a crucial role for PAI-1 in angiogenesis. These data stress the importance of a balanced proteolysis in the processes of invasion, migration and angiogenesis. Our results support the clinical findings and indicate that modulation of PAI-1 activity, with low-molecular-weight inhibitor of PAI-1 activity, may be of therapeutic benefit for the treatment of cancer.

  3. Inflammatory cytokine tumor necrosis factor α suppresses neuroprotective endogenous erythropoietin from astrocytes mediated by hypoxia-inducible factor-2α.

    PubMed

    Nagaya, Yoshiaki; Aoyama, Mineyoshi; Tamura, Tetsuya; Kakita, Hiroki; Kato, Shin; Hida, Hideki; Saitoh, Shinji; Asai, Kiyofumi

    2014-12-01

    Interest in erythropoietin (EPO) as a neuroprotective mediator has grown since it was found that systemically administered EPO is protective in several animal models of disease. However, given that the blood-brain barrier limits EPO entry into the brain, alternative approaches that induce endogenous EPO production in the brain may be more effective clinically and associated with fewer untoward side-effects. Astrocytes are the main source of EPO in the central nervous system. In the present study we investigated the effect of the inflammatory cytokine tumor necrosis factor α (TNFα) on hypoxia-induced upregulation of EPO in rat brain. Hypoxia significantly increased EPO mRNA expression in the brain and kidney, and this increase was suppressed by TNFα in vivo. In cultured astrocytes exposed to hypoxic conditions for 6 and 12 h, TNFα suppressed the hypoxia-induced increase in EPO mRNA expression in a concentration-dependent manner. TNFα inhibition of hypoxia-induced EPO expression was mediated primarily by hypoxia-inducible factor (HIF)-2α rather than HIF-1α. The effects of TNFα in reducing hypoxia-induced upregulation of EPO mRNA expression probably involve destabilization of HIF-2α, which is regulated by the nuclear factor (NF)-κB signaling pathway. TNFα treatment attenuated the protective effects of astrocytes on neurons under hypoxic conditions via EPO signaling. The effective blockade of TNFα signaling may contribute to the maintenance of the neuroprotective effects of EPO even under hypoxic conditions with an inflammatory response. PMID:25283246

  4. Targeting NF-kappaB signaling pathway suppresses tumor growth, angiogenesis, and metastasis of human esophageal cancer.

    PubMed

    Li, Bin; Li, Yuk Yin; Tsao, Sai Wah; Cheung, Annie L M

    2009-09-01

    Esophageal cancer is the eighth most common malignancy, and one of the leading causes of cancer-related deaths worldwide. The overall 5-year survival rate of patients with esophageal cancer remains low at 10% to 40% due to late diagnosis, metastasis, and resistance of the tumor to radiotherapy and chemotherapy. NF-kappaB is involved in the regulation of cell growth, survival, and motility, but little is known about the role of this signaling pathway in the tumorigenesis of human esophageal squamous cell carcinoma (ESCC), the most common form of esophageal cancer. This study aims to explore the functions of NF-kappaB in human ESCC progression and to determine whether targeting the NF-kappaB signaling pathway might be of therapeutic value against ESCC. Our results from human ESCC cell lines and ESCC tissue indicated that NF-kappaB is constitutively active in ESCC. Exposure of ESCC cells to two NF-kappaB inhibitors, Bay11-7082 and sulfasalazine, not only reduced cancer cell proliferation, but also induced apoptosis and enhanced sensitivity to chemotherapeutic drugs, 5-fluorouracil, and cisplatin. In addition, Bay11-7082 and sulfasalazine suppressed the migration and invasive potential of ESCC cells. More importantly, the results from tumor xenograft and experimental metastasis models showed that Bay11-7082 had significant antitumor effects on ESCC xenografts in nude mice by promoting apoptosis, and inhibiting proliferation and angiogenesis, as well as reduced the metastasis of ESCC cells to the lungs without significant toxic effects. In summary, our data suggest that NF-kappaB inhibitors may be potentially useful as therapeutic agents for patients with esophageal cancer.

  5. Mechanism of dexamethasone suppression of brain tumor-associated vascular permeability in rats. Involvement of the glucocorticoid receptor and vascular permeability factor.

    PubMed Central

    Heiss, J D; Papavassiliou, E; Merrill, M J; Nieman, L; Knightly, J J; Walbridge, S; Edwards, N A; Oldfield, E H

    1996-01-01

    Brain tumor-associated cerebral edema arises because tumor capillaries lack normal blood-brain barrier function; vascular permeability factor (VPF, also known as vascular endothelial growth factor, VEGF) is a likely mediator of this phenomenon. Clinically, dexamethasone reduces brain tumor-associated vascular permeability through poorly understood mechanisms. Our goals were to determine if suppression of permeability by dexamethasone might involve inhibition of VPF action or expression, and if dexamethasone effects in this setting are mediated by the glucocorticoid receptor (GR). In two rat models of permeability (peripheral vascular permeability induced by intradermal injection of 9L glioma cell-conditioned medium or purified VPF, and intracerebral vascular permeability induced by implanted 9L glioma), dexamethasone suppressed permeability in a dose-dependent manner. Since 80% of the permeability-inducing activity in 9L-conditioned medium was removed by anti-VPF antibodies, we examined dexamethasone effects of VPF expression in 9L cells. Dexamethasone inhibited FCS- and PDGF-dependent induction of VPF expression. At all levels (intradermal, intracranial, and cell culture), dexamethasone effects were reversed by the GR antagonist mifepristone (RU486). Dexamethasone may decrease brain tumor-associated vascular permeability by two GR-dependent mechanisms: reduction of the response of the vasculature to tumor-derived permeability factors (including VPF), and reduction of VPF expression by tumor cells. PMID:8823305

  6. Improvement of the tumor-suppressive effect of boron neutron capture therapy for amelanotic melanoma by intratumoral injection of the tyrosinase gene.

    PubMed

    Morita, Norimasa; Hiratsuka, Junichi; Kondoh, Hirohumi; Uno, Masako; Asano, Tomoyuki; Niki, Yoko; Sakurai, Yoshinori; Ono, Koji; Harada, Tamotsu; Imajo, Yoshinari

    2006-04-01

    Boron neutron capture therapy (BNCT) is successful when there is a sufficient (10)B concentration in tumor cells. In melanoma, (10)B-para-boronophenylalanine (BPA) accumulation is proportional to melanin-producing activity. This study was done to confirm enhancement of the tumor-suppressive effect of BNCT on amelanotic melanoma by intratumoral injection of the tyrosinase gene. D178 or FF amelanotic melanomas were implanted s.c. in Syrian hamsters. One group of D178- or FF-bearing hamsters (TD178 or TFF group) received intratumoral injections of pcDNA-Tyrs constructed as a tyrosinase expression plasmid. The other hamsters (pD178 and pFF groups) were injected with pUC119, and control hamsters (D178 and FF groups) only with transfection reagents. All the groups underwent immunofluorescence analysis of tyrosinase expression and BPA biodistribution studies. BNCT experiments were done at the Kyoto University Research Reactor. Tyrosinase expression increased in the tumors of the TD178 and TFF groups but remained the same in the pD178 and pFF groups. Tumor boron concentrations in the TD178 and TFF groups increased significantly (TD178: 49.7 +/- 12.6 versus D178: 27.2 +/- 4.9 microg/g, P < 0.0001; TFF: 30.7 +/- 6.6 versus FF: 13.0 +/- 4.7 microg/g, P < 0.0001). The BNCT tumor-suppressive effect was marked in the TD178 and TFF groups. In vivo transfection with the tyrosinase gene increased BPA accumulation in the tumors, the BNCT tumor-suppressive effect on amelanotic melanoma being significantly enhanced. These findings suggest a potential new clinical strategy for the treatment of amelanotic melanoma with BNCT.

  7. AAVrh.10-mediated genetic delivery of bevacizumab to the pleura to provide local anti-VEGF to suppress growth of metastatic lung tumors.

    PubMed

    Watanabe, M; Boyer, J L; Crystal, R G

    2010-08-01

    Vascular endothelial growth factor (VEGF) produced by tumor cells has a central role in stimulating angiogenesis required for tumor growth. Humanized monoclonal anti-VEGF antibody (bevacizumab, Avastin), approved as a treatment for non-squamous, non-small cell lung cancer, requires administration every 3 weeks. We hypothesized that an intrapleural administration of an adeno-associated virus (AAV) vector expressing an anti-VEGF-A antibody equivalent of bevacizumab would result in sustained anti-VEGF-A localized expression within the lung and suppress metastatic tumor growth. The AAV vector AAVrh.10alphaVEGF encodes the light chain and heavy chain complementary DNAs of monoclonal antibody A.4.6.1, a murine antibody that specifically recognizes human VEGF-A with the same antigen-binding site as bevacizumab. A metastatic lung tumor model was established in severe combined immunodeficient mice by intravenous administration of human DU145 prostate carcinoma cells. Intrapleural administration of AAVrh.10alphaVEGF directed long-term expression of the anti-human VEGF-A antibody in lung, as shown by sustained, high-level anti-human VEGF titers in lung epithelial lining fluid for 40 weeks, which was the duration of the study. In the AAVrh.10alphaVEGF-treated animals, tumor growth was significantly suppressed (P<0.05), the numbers of blood vessels and mitotic nuclei in the tumor was decreased (P<0.05) and there was increased survival (P<0.05). Thus, intrapleural administration of an AAVrh.10 vector, encoding the murine monoclonal antibody equivalent of bevacizumab, effectively suppresses the growth of metastatic lung tumors, suggesting AAV-mediated gene transfer to the pleura to deliver bevacizumab locally to the lung as a novel alternative platform to conventional monoclonal antibody therapy.

  8. Dehydroeffusol inhibits gastric cancer cell growth and tumorigenicity by selectively inducing tumor-suppressive endoplasmic reticulum stress and a moderate apoptosis.

    PubMed

    Zhang, Bin; Han, Hongyan; Fu, Shilong; Yang, Ping; Gu, Zhenlun; Zhou, Quansheng; Cao, Zhifei

    2016-03-15

    Gastric cancer is ranked as the third leading cause of cancer-related death in the world. Although extensive efforts have been made in recent decades to treat gastric cancer with various anticancer drugs, effective anti-gastric cancer therapeutics to cure the disease are still lacking in the clinics. Therefore, potent novel anti-gastric cancer drugs are greatly needed. In this study, we explored a novel anti-gastric cancer agent from a medicinal herb named Juncus effusus and found that the active component dehydroeffusol (DHE), a small molecular phenanthrene, effectively inhibited gastric cancer cell proliferation and tumorigenesis by inducing tumor suppressive endoplasmic reticulum (ER) stress and by triggering moderate apoptosis. Mechanistic studies revealed that DHE selectively activated the intracellular tumor suppressive stress response by promoting the overexpression of the key ER stress marker DNA damage-inducible transcript 3 (DDIT3), through upregulation of activating transcription factor 4 (ATF4). Concurrently, DHE suppressed the expression of the cell survival and ER stress marker glucose regulated protein of molecular mass 78 (GRP78) via downregulation of the transcription factor ATF6. In addition, DHE markedly activated the stress response signaling pathway MEKK4-MKK3/6-p38-DDIT3, but significantly inhibited ERK signaling. Our data suggest that DHE inhibits gastric cancer cell growth and tumorigenicity through selectively inducing a robust tumor suppressive ER stress response and a moderate apoptosis response. Therefore, DHE may provide a novel drug candidate for further development of potential anti-gastric cancer therapeutics. PMID:26774454

  9. Tumor-suppressive microRNA-145 induces growth arrest by targeting SENP1 in human prostate cancer cells

    PubMed Central

    Wang, Chunyang; Tao, Weiyang; Ni, Shaobin; Chen, Qiyin; Zhao, Zhongshan; Ma, Li; Fu, Yiming; Jiao, Zhixing

    2015-01-01

    Prostate cancer (PCa) prevails as the most commonly diagnosed malignancy in men and the third leading cause of cancer-related deaths in developed countries. One of the distinct characteristics of prostate cancer is overexpression of the small ubiquitin-like modifier (SUMO)-specific protease 1 (SENP1), and the upregulation of SENP1 contributes to the malignant progression and cell proliferation of PCa. Previous studies have shown that the expression of microRNA-145 (miRNA-145) was extensively deregulated in PCa cell lines and primary clinical prostate cancer samples. Independent target prediction methods have indicated that the 3′-untranslated region of SENP1 mRNA is a potential target of miR-145. Here we found that low expression of miR-145 was correlated with high expression of SENP1 in PCa cell line PC-3. The transient introduction of miR-145 caused cell cycle arrest in PC-3 cells, and the opposite effect was observed when miR-145 inhibitor was transfected. Further studies revealed that the SENP1 3′-untranslated region was a regulative target of miR-145 in vitro. MicroRNA-145 also suppressed tumor formation in vivo in nude mice. Taken together, miR-145 plays an important role in tumorigenesis of PCa through interfering SENP1. PMID:25645686

  10. Antroquinonol Targets FAK-Signaling Pathway Suppressed Cell Migration, Invasion, and Tumor Growth of C6 Glioma.

    PubMed

    Thiyagarajan, Varadharajan; Tsai, May-Jywan; Weng, Ching-Feng

    2015-01-01

    Focal adhesion kinase (FAK) is a non-receptor protein tyrosine that is overexpressed in many types of tumors and plays a pivotal role in multiple cell signaling pathways involved in cell survival, migration, and proliferation. This study attempts to determine the effect of synthesized antroquinonol on the modulation of FAK signaling pathways and explore their underlying mechanisms. Antroquinonol significantly inhibits cell viability with an MTT assay in both N18 neuroblastoma and C6 glioma cell lines, which exhibits sub G1 phase cell cycle, and further induction of apoptosis is confirmed by a TUNEL assay. Antroquinonol decreases anti-apoptotic proteins, whereas it increases p53 and pro-apoptotic proteins. Alterations of cell morphology are observed after treatment by atomic force microscopy. Molecular docking results reveal that antroquinonol has an H-bond with the Arg 86 residue of FAK. The protein levels of Src, pSrc, FAK, pFAK, Rac1, and cdc42 are decreased after antroquinonol treatment. Additionally, antroquinonol also regulates the expression of epithelial to mesenchymal transition (EMT) proteins. Furthermore, antroquinonol suppresses the C6 glioma growth in xenograft studies. Together, these results suggest that antroquinonol is a potential anti-tumorigenesis and anti-metastasis inhibitor of FAK. PMID:26517117

  11. Tumor-suppressive microRNAs (miR-26a/b, miR-29a/b/c and miR-218) concertedly suppressed metastasis-promoting LOXL2 in head and neck squamous cell carcinoma.

    PubMed

    Fukumoto, Ichiro; Kikkawa, Naoko; Matsushita, Ryosuke; Kato, Mayuko; Kurozumi, Akira; Nishikawa, Rika; Goto, Yusuke; Koshizuka, Keiichi; Hanazawa, Toyoyuki; Enokida, Hideki; Nakagawa, Masayuki; Okamoto, Yoshitaka; Seki, Naohiko

    2016-02-01

    In spite of considerable advances in multimodality therapy, including surgery, radiotherapy and chemotherapy, the overall survival rate for patients with head and neck squamous cell carcinoma (HNSCC) is very poor (only 15-45%). Understanding the molecular mechanisms of metastatic pathways underlying HNSCC using currently available genomic approaches might improve therapies for and prevention of the disease. Our previous studies showed that three tumor-suppressive microRNAs (miRNAs), miR-26a/b, miR-29a/b/c and miR-218, significantly inhibited cancer cell migration and invasion. Therefore, we hypothesized that these miRNAs-regulated target genes deeply contributed to cancer metastasis. These tumor-suppressive miRNAs directly regulate LOXL2 expression in HNSCC cells by using in silico analysis and luciferase reporter assays. Overexpressed LOXL2 was confirmed in HNSCC clinical specimens, and silencing of LOXL2 inhibited cancer cell migration and invasion in HNSCC cell lines. Our present data showed that tumor-suppressive miRNAs regulation of LOXL2 will provide new insights into the novel molecular mechanisms of HNSCC metastasis.

  12. Suppression of human breast tumors in NOD/SCID mice by CD44 shRNA gene therapy combined with doxorubicin treatment

    PubMed Central

    Van Pham, Phuc; Vu, Ngoc Bich; Duong, Thuy Thanh; Nguyen, Tam Thanh; Truong, Nhung Hai; Phan, Nhan Lu Chinh; Vuong, Tue Gia; Pham, Viet Quoc; Nguyen, Hoang Minh; Nguyen, Kha The; Nguyen, Nhung Thi; Nguyen, Khue Gia; Khat, Lam Tan; Van Le, Dong; Truong, Kiet Dinh; Phan, Ngoc Kim

    2012-01-01

    Background Breast cancer stem cells with a CD44+CD24− phenotype are the origin of breast tumors. Strong CD44 expression in this population indicates its important role in maintaining the stem cell phenotype. Previous studies show that CD44 down-regulation causes CD44+CD24− breast cancer stem cells to differentiate into non-stem cells that are sensitive to antitumor drugs and lose many characteristics of the original cells. In this study, we determined tumor suppression in non-obese severe combined immunodeficiency mice using CD44 shRNA therapy combined with doxorubicin treatment. Methods Tumor-bearing non-obese severe combined immunodeficiency mice were established by injection of CD44+CD24− cells. To track CD44+CD24− cells, green fluorescence protein was stably transduced using a lentiviral vector prior to injection into mice. The amount of CD44 shRNA lentiviral vector used for transduction was based on CD44 down-regulation by in vitro CD44 shRNA transduction. Mice were treated with direct injection of CD44 shRNA lentiviral vector into tumors followed by doxorubicin administration after 48 hours. The effect was evaluated by changes in the size and weight of tumors compared with that of the control. Results The combination of CD44 down-regulation and doxorubicin strongly suppressed tumor growth with significant differences in tumor sizes and weights compared with that of CD44 down-regulation or doxorubicin treatment alone. In the combination of CD44 down-regulation and doxorubicin group, the tumor weight was significantly decreased by 4.38-fold compared with that of the control group. Conclusion These results support a new strategy for breast cancer treatment by combining gene therapy with chemotherapy. PMID:22649280

  13. The traditional Chinese medicinal formula BDL301 suppresses tumor growth by inhibiting STAT3 pathway and inducing apoptosis in colorectal cancer cells.

    PubMed

    Chu, Li; Zhao, Huaxin; Fang, Juemin; Li, Chunyan; Liu, Zhuqing; Cui, Ran; Hu, Fei; Zhang, Xi; Chen, Yijing; Han, Hui; Cao, Chuanhai; Xu, Qing

    2015-03-01

    The traditional Chinese medicinal formula BDL301 has been used to inhibit inflammation for hundreds of years. The development of colorectal cancer and chronic inflammation are closely related. In this study, we investigated whether BDL301 could inhibit tumor growth. We found that angiogenesis and tumor growth were both inhibited in vivo. In addition, apoptosis was induced and the signal transducer and activator of transcription-3 (STAT3) pathway were suppressed in the colorectal cancer cells in vitro and in vivo by BDL301. This study demonstrates that BDL301 exerted significant anticancer activity by inhibiting the STAT3 pathways and inducing apoptosis in colorectal cancer cells.

  14. Autologous formalin-fixed tumor vaccine suppressed re-recurrence of HCV-related hepatocellular carcinoma following 29 unsuccessful treatments with extensive conventional therapy: a case report.

    PubMed

    Inui, Toshio; Ohno, Tadao

    2012-01-01

    Treatment of hepatocellular carcinoma (HCC) with autologous formalin-fixed tumor vaccine after primary resection has been shown to suppress the recurrence of hepatitis B virus-associated HCC, but the effect of this treatment on hepatitis C virus (HCV)-related disease has not yet been clarified. Here, we report a case of a patient with repeat recurrent HCC that was associated with HCV who had endured 29 episodes of HCC recurrence despite a variety of therapy using conventional methods. Finally, treatment with a single course of autologous formalin-fixed tumor vaccine resulted in suppression of potential further re-recurrence of HCC for more than 43 months without any additional treatment. PMID:22789008

  15. Suppression of tumor angiogenesis by metformin treatment via a mechanism linked to targeting of HER2/HIF-1α/VEGF secretion axis.

    PubMed

    Wang, Jichang; Li, Guangyue; Wang, Yaochun; Tang, Shouching; Sun, Xin; Feng, Xuefei; Li, Yan; Bao, Gang; Li, Pingping; Mao, Xiaona; Wang, Maode; Liu, Peijun

    2015-12-29

    Anti-angiogenesis is currently considered as one of the major antitumor strategies for its protective effects against tumor emergency and later progression. The anti-diabetic drug metformin has been demonstrated to significantly inhibit tumor angiogenesis based on recent studies. However, the mechanism underlying this anti-angiogenic effect still remains an enigma. In this study, we investigated metformin-induced inhibitory effect on tumor angiogenesis in vitro and in vivo. Metformin pretreatment significantly suppressed tumor paracrine signaling-induced angiogenic promotion even in the presence of heregulin (HRG)-β1 (a co-activator of HER2) pretreatment of HER2+ tumor cells. Similar to that of AG825, a specific inhibitor of HER2 phosphorylation, metformin treatment decreased both total and phosphorylation (Tyr 1221/1222) levels of HER2 protein and significantly reduced microvessel density and the amount of Fitc-conjugated Dextran leaking outside the vessel. Furthermore, our results of VEGF-neutralizing and -rescuing tests showed that metformin markedly abrogated HER2 signaling-induced tumor angiogenesis by inhibiting VEGF secretion. Inhibition of HIF-1α signaling by using RNAi or YC-1, a specific inhibitor of HIF-1α synthesis, both completely diminished mRNA level of VEGF and greatly inhibited endothelial cell proliferation promoted by HER2+ tumor cell-conditioned medium in both the absence and presence of HRG-β1 pretreatment. Importantly, metformin treatment decreased the number of HIF-1α nucleus positive cells in 4T1 tumors, accompanied by decreased microvessel density. Our data thus provides novel insight into the mechanism underlying the metformin-induced inhibition of tumor angiogenesis and indicates possibilities of HIF-1α-VEGF signaling axis in mediating HER2-induced tumor angiogenesis. PMID:26625311

  16. Suppression of tumor angiogenesis by metformin treatment via a mechanism linked to targeting of HER2/HIF-1α/VEGF secretion axis.

    PubMed

    Wang, Jichang; Li, Guangyue; Wang, Yaochun; Tang, Shouching; Sun, Xin; Feng, Xuefei; Li, Yan; Bao, Gang; Li, Pingping; Mao, Xiaona; Wang, Maode; Liu, Peijun

    2015-12-29

    Anti-angiogenesis is currently considered as one of the major antitumor strategies for its protective effects against tumor emergency and later progression. The anti-diabetic drug metformin has been demonstrated to significantly inhibit tumor angiogenesis based on recent studies. However, the mechanism underlying this anti-angiogenic effect still remains an enigma. In this study, we investigated metformin-induced inhibitory effect on tumor angiogenesis in vitro and in vivo. Metformin pretreatment significantly suppressed tumor paracrine signaling-induced angiogenic promotion even in the presence of heregulin (HRG)-β1 (a co-activator of HER2) pretreatment of HER2+ tumor cells. Similar to that of AG825, a specific inhibitor of HER2 phosphorylation, metformin treatment decreased both total and phosphorylation (Tyr 1221/1222) levels of HER2 protein and significantly reduced microvessel density and the amount of Fitc-conjugated Dextran leaking outside the vessel. Furthermore, our results of VEGF-neutralizing and -rescuing tests showed that metformin markedly abrogated HER2 signaling-induced tumor angiogenesis by inhibiting VEGF secretion. Inhibition of HIF-1α signaling by using RNAi or YC-1, a specific inhibitor of HIF-1α synthesis, both completely diminished mRNA level of VEGF and greatly inhibited endothelial cell proliferation promoted by HER2+ tumor cell-conditioned medium in both the absence and presence of HRG-β1 pretreatment. Importantly, metformin treatment decreased the number of HIF-1α nucleus positive cells in 4T1 tumors, accompanied by decreased microvessel density. Our data thus provides novel insight into the mechanism underlying the metformin-induced inhibition of tumor angiogenesis and indicates possibilities of HIF-1α-VEGF signaling axis in mediating HER2-induced tumor angiogenesis.

  17. Tumor suppressive microRNA-133a regulates novel targets: Moesin contributes to cancer cell proliferation and invasion in head and neck squamous cell carcinoma

    SciTech Connect

    Kinoshita, Takashi; Nohata, Nijiro; Fuse, Miki; Hanazawa, Toyoyuki; Kikkawa, Naoko; Fujimura, Lisa; Watanabe-Takano, Haruko; Yamada, Yasutoshi; Yoshino, Hirofumi; Enokida, Hideki; Nakagawa, Masayuki; Okamoto, Yoshitaka; Seki, Naohiko

    2012-02-10

    Highlights: Black-Right-Pointing-Pointer Tumor suppressive microRNA-133a regulates moesin (MSN) expression in HNSCC. Black-Right-Pointing-Pointer Silencing of MSN in HNSCC cells suppressed proliferation, migration and invasion. Black-Right-Pointing-Pointer The expression level of MSN was significantly up-regulated in cancer tissues. -- Abstract: Recently, many studies suggest that microRNAs (miRNAs) contribute to the development, invasion and metastasis of various types of human cancers. Our recent study revealed that expression of microRNA-133a (miR-133a) was significantly reduced in head and neck squamous cell carcinoma (HNSCC) and that restoration of miR-133a inhibited cell proliferation, migration and invasion in HNSCC cell lines, suggesting that miR-133a function as a tumor suppressor. Genome-wide gene expression analysis of miR-133a transfectants and TargetScan database showed that moesin (MSN) was a promising candidate of miR-133a target gene. MSN is a member of the ERM (ezrin, radixin and moesin) protein family and ERM function as cross-linkers between plasma membrane and actin-based cytoskeleton. The functions of MSN in cancers are controversial in previous reports. In this study, we focused on MSN and investigated whether MSN was regulated by tumor suppressive miR-133a and contributed to HNSCC oncogenesis. Restoration of miR-133a in HNSCC cell lines (FaDu, HSC3, IMC-3 and SAS) suppressed the MSN expression both in mRNA and protein level. Silencing study of MSN in HNSCC cell lines demonstrated significant inhibitions of cell proliferation, migration and invasion activities in si-MSN transfectants. In clinical specimen with HNSCC, the expression level of MSN was significantly up-regulated in cancer tissues compared to adjacent non-cancerous tissues. These data suggest that MSN may function as oncogene and is regulated by tumor suppressive miR-133a. Our analysis data of novel tumor-suppressive miR-133a-mediated cancer pathways could provide new insights into

  18. Enhanced suppression of tumor growth by concomitant treatment of human lung cancer cells with suberoylanilide hydroxamic acid and arsenic trioxide

    SciTech Connect

    Chien, Chia-Wen; Yao, Ju-Hsien; Chang, Shih-Yu; Lee, Pei-Chih; Lee, Te-Chang

    2011-11-15

    The efficacy of arsenic trioxide (ATO) against acute promyelocytic leukemia (APL) and relapsed APL has been well documented. ATO may cause DNA damage by generating reactive oxygen intermediates. Suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor, modulates gene and protein expression via histone-dependent or -independent pathways that may result in chromatin decondensation, cell cycle arrest, differentiation, and apoptosis. We investigated whether ATO and SAHA act synergistically to enhance the death of cancer cells. Our current findings showed that combined treatment with ATO and SAHA resulted in enhanced suppression of non-small-cell lung carcinoma in vitro in H1299 cells and in vivo in a xenograft mouse model. Flow cytometric analysis of annexin V+ cells showed that apoptotic cell death was significantly enhanced after combined treatment with ATO and SAHA. At the doses used, ATO did not interfere with cell cycle progression, but SAHA induced p21 expression and led to G1 arrest. A Comet assay demonstrated that ATO, but not SAHA, induced DNA strand breaks in H1299 cells; however, co-treatment with SAHA significantly increased ATO-induced DNA damage. Moreover, SAHA enhanced acetylation of histone H3 and sensitized genomic DNA to DNase I digestion. Our results suggest that SAHA may cause chromatin relaxation and increase cellular susceptibility to ATO-induced DNA damage. Combined administration of SAHA and ATO may be an effective approach to the treatment of lung cancer. -- Highlights: Black-Right-Pointing-Pointer ATO and SAHA are therapeutic agents with different action modes. Black-Right-Pointing-Pointer Combination of ATO and SAHA synergistically inhibits tumor cell growth. Black-Right-Pointing-Pointer SAHA loosens chromatin structure resulting in increased sensitivity to DNase I. Black-Right-Pointing-Pointer ATO-induced DNA damage and apoptosis are enhanced by co-treatment with SAHA.

  19. Direct regulation of LAMP1 by tumor-suppressive microRNA-320a in prostate cancer

    PubMed Central

    OKATO, ATSUSHI; GOTO, YUSUKE; KUROZUMI, AKIRA; KATO, MAYUKO; KOJIMA, SATOKO; MATSUSHITA, RYOSUKE; YONEMORI, MASAYA; MIYAMOTO, KAZUTAKA; ICHIKAWA, TOMOHIKO; SEKI, NAOHIKO

    2016-01-01

    Advanced prostate cancer (PCa) metastasizes to bone and lymph nodes, and currently available treatments cannot prevent the progression and metastasis of the disease. Therefore, an improved understanding of the molecular mechanisms of the progression and metastasis of advanced PCa using current genomic approaches is needed. Our miRNA expression signature in castration-resistant prostate cancer (CRPC) revealed that microRNA-320a (miR-320a) was significantly reduced in cancer tissues, suggesting that miR-320a may be a promising anticancer miRNA. The aim of this study was to investigate the functional roles of miR-320a in naïve PCa and CRPC cells and to identify miR-320a-regulated genes involved in PCa metastasis. The expression levels of miR-320a were significantly reduced in naïve PCa, CRPC specimens, and PCa cell lines. Restoration of mature miR-320a in PCa cell lines showed that miR-320a significantly inhibited cancer cell migration and invasion. Moreover, we found that lysosomal-associated membrane protein 1 (LAMP1) was a direct target of miR-320a in PCa cells. Silencing of LAMP1 using siRNA significantly inhibited cell proliferation, migration, and invasion in PCa cells. Overexpression of LAMP1 was observed in PCa and CRPC clinical specimens. Moreover, downstream pathways were identified using si-LAMP1-transfected cells. The discovery of tumor-suppressive miR-320a-mediated pathways may provide important insights into the potential mechanisms of PCa metastasis. PMID:27212625

  20. miR-503 suppresses tumor cell proliferation and metastasis by directly targeting RNF31 in prostate cancer

    SciTech Connect

    Guo, Jia; Liu, Xiuheng Wang, Min

    2015-09-04

    Microarray data analyses were performed to search for metastasis-associated oncogenes in prostate cancer (PCa). RNF31 mRNA expressions in tumor tissues and benign prostate tissues were evaluated. The RNF31 protein expression levels were also analyzed by western blot and immunohistochemistry. Luciferase reporter assays were used to identify miRNAs that can regulate RNF31. The effect of RNF31 on PCa progression was studied in vitro and in vivo. We found that RNF31 was significantly increased in PCa and its expression level was highly correlated with seminal vesicle invasion, clinical stage, prostate specific antigen (PSA) level, Gleason score, and BCR. Silence of RNF31 suppressed PCa cell proliferation and metastasis in vitro and in vivo. miR-503 can directly regulate RNF31. Enforced expression of miR-503 inhibited the expression of RNF31 significantly and the restoration of RNF31 expression reversed the inhibitory effects of miR-503 on PCa cell proliferation and metastasis. These findings collectively indicated an oncogene role of RNF31 in PCa progression which can be regulated by miR-503, suggesting that RNF31 could serve as a potential prognostic biomarker and therapeutic target for PCa. - Highlights: • RNF31 is a potential metastasis associated gene and is associated with prostate cancer progression. • Silence of RNF31 inhibits PCa cell colony formation, migration and invasion. • RNF31 as a direct target of miR-503. • miR-503 can regulate cell proliferation, invasion and migration by targeting RNF31. • RNF31 plays an important role in PCa growth and metastasis in vivo.

  1. Tumor-suppressive microRNA-218 inhibits cancer cell migration and invasion via targeting of LASP1 in prostate cancer

    PubMed Central

    Nishikawa, Rika; Goto, Yusuke; Sakamoto, Shinichi; Chiyomaru, Takeshi; Enokida, Hideki; Kojima, Satoko; Kinoshita, Takashi; Yamamoto, Noriko; Nakagawa, Masayuki; Naya, Yukio; Ichikawa, Tomohiko; Seki, Naohiko

    2014-01-01

    Our recent studies of the microRNA (miRNA) expression signature in prostate cancer (PCa) indicated that miRNA-218 (miR-218) was significantly downregulated in clinical specimens, suggesting that miR-218 might act as a tumor-suppressive miRNA in PCa. The aim of the present study was to investigate the functional significance of miR-218 in PCa and to identify novel miR-218-regulated cancer pathways and target genes involved in PCa oncogenesis and metastasis. Restoration of miR-218 in PCa cell lines (PC3 and DU145) revealed that this miRNA significantly inhibited cancer cell migration and invasion. Gene expression data and in silico analysis demonstrated that LIM and SH3 protein 1 (LASP1) is a potential target of miR-218 regulation. LASP1 is a cytoskeletal scaffold protein that plays critical roles in cytoskeletal organization and cell migration. Luciferase reporter assays showed that miR-218 directly regulated expression of LASP1. Moreover, downregulating the LASP1 gene significantly inhibited cell migration and invasion in cancer cells, and the expression of LASP1 was upregulated in cancer tissues. We conclude that loss of tumor-suppressive miR-218 enhanced cancer cell migration and invasion in PCa through direct regulation of LASP1. Our data on pathways regulated by tumor-suppressive miR-218 provide new insight into the potential mechanisms of PCa oncogenesis and metastasis. PMID:24815849

  2. Inhibition of Calcium-Activated Chloride Channel ANO1/TMEM16A Suppresses Tumor Growth and Invasion in Human Lung Cancer.

    PubMed

    Jia, Linghan; Liu, Wen; Guan, Lizhao; Lu, Min; Wang, KeWei

    2015-01-01

    Lung cancer or pulmonary carcinoma is primarily derived from epithelial cells that are thin and line on the alveolar surfaces of the lung for gas exchange. ANO1/TMEM16A, initially identified from airway epithelial cells, is a member of Ca2+-activated Cl- channels (CaCCs) that function to regulate epithelial secretion and cell volume for maintenance of ion and tissue homeostasis. ANO1/TMEM16A has recently been shown to be highly expressed in several epithelium originated carcinomas. However, the role of ANO1 in lung cancer remains unknown. In this study, we show that inhibition of calcium-activated chloride channel ANO1/TMEM16A suppresses tumor growth and invasion in human lung cancer. ANO1 is upregulated in different human lung cancer cell lines. Knocking-down ANO1 by small hairpin RNAs inhibited proliferation, migration and invasion of GLC82 and NCI-H520 cancel cells evaluated by CCK-8, would-healing, transwell and 3D soft agar assays. ANO1 protein is overexpressed in 77.3% cases of human lung adenocarcinoma tissues detected by immunohistochemistry. Furthermore, the tumor growth in nude mice implanted with GLC82 cells was significantly suppressed by ANO1 silencing. Taken together, our findings provide evidence that ANO1 overexpression contributes to tumor growth and invasion of lung cancer; and suppressing ANO1 overexpression may have therapeutic potential in lung cancer therapy.

  3. Artesunate suppresses tumor growth and induces apoptosis through the modulation of multiple oncogenic cascades in a chronic myeloid leukemia xenograft mouse model

    PubMed Central

    Kim, Chulwon; Lee, Jong Hyun; Kim, Sung-Hoon; Sethi, Gautam; Ahn, Kwang Seok

    2015-01-01

    Artesunate (ART), a semi-synthetic derivative of artemisinin, is one of the most commonly used anti-malarial drugs. Also, ART possesses anticancer potential albeit through incompletely understood molecular mechanism(s). Here, the effect of ART on various protein kinases, associated gene products, cellular response, and apoptosis was investigated. The in vivo effect of ART on the growth of human CML xenograft tumors in athymic nu/nu mice was also examined. In our preliminary experiments, we first observed that phosphorylation of p38, ERK, CREB, Chk-2, STAT5, and RSK proteins were suppressed upon ART exposure. Interestingly, ART induced the expression of SOCS-1 protein and depletion of SOCS-1 using siRNA abrogated the STAT5 inhibitory effect of the drug. Also various dephosphorylations caused by ART led to the suppression of various survival gene products and induced apoptosis through caspase-3 activation. Moreover, ART also substantially potentiated the apoptosis induced by chemotherapeutic agents. Finally, when administered intraperitoneally, ART inhibited p38, ERK, STAT5, and CREB activation in tumor tissues and the growth of human CML xenograft tumors in mice without exhibiting any significant adverse effects. Overall, our results suggest that ART exerts its anti-proliferative and pro-apoptotic effects through suppression of multiple signaling cascades in CML both in vitro and in vivo. PMID:25738364

  4. Merlin/NF2 Suppresses Pancreatic Tumor Growth and Metastasis by Attenuating the FOXM1-Mediated Wnt/β-Catenin Signaling.

    PubMed

    Quan, Ming; Cui, Jiujie; Xia, Tian; Jia, Zhiliang; Xie, Dacheng; Wei, Daoyan; Huang, Suyun; Huang, Qian; Zheng, Shaojiang; Xie, Keping

    2015-11-15

    Merlin, the protein encoded by the NF2 gene, is a member of the band 4.1 family of cytoskeleton-associated proteins and functions as a tumor suppressor for many types of cancer. However, the roles and mechanism of Merlin expression in pancreatic cancer have remained unclear. In this study, we sought to determine the impact of Merlin expression on pancreatic cancer development and progression using human tissue specimens, cell lines, and animal models. Decreased expression of Merlin was pronounced in human pancreatic tumors and cancer cell lines. Functional analysis revealed that restored expression of Merlin inhibited pancreatic tumor growth and metastasis in vitro and in vivo. Furthermore, Merlin suppressed the expression of Wnt/β-catenin signaling downstream genes and the nuclear expression of β-catenin protein, and overexpression of Forkhead box M1 (FOXM1) attenuated the suppressive effect of Merlin on Wnt/β-catenin signaling. Mechanistically, Merlin decreased the stability of FOXM1 protein, which plays critical roles in nuclear translocation of β-catenin. Collectively, these findings demonstrated that Merlin critically regulated pancreatic cancer pathogenesis by suppressing FOXM1/β-catenin signaling, suggesting that targeting novel Merlin/FOXM1/β-catenin signaling is an effective therapeutic strategy for pancreatic cancer.

  5. Peripheral Opioid Antagonist Enhances the Effect of Anti-Tumor Drug by Blocking a Cell Growth-Suppressive Pathway In Vivo

    PubMed Central

    Sawada, Yumi; Ashikawa, Maho; Aoyagi, Kazuhiko; Fujita, Takeshi; Yanagihara, Kazuyoshi; Komatsu, Masayuki; Narita, Minoru; Suzuki, Tsutomu; Nagase, Hiroshi; Kushima, Ryoji; Sakamoto, Hiromi; Fukagawa, Takeo; Katai, Hitoshi; Nakagama, Hitoshi; Yoshida, Teruhiko; Uezono, Yasuhito; Sasaki, Hiroki

    2015-01-01

    The dormancy of tumor cells is a major problem in chemotherapy, since it limits the therapeutic efficacy of anti-tumor drugs that only target dividing cells. One potential way to overcome chemo-resistance is to “wake up” these dormant cells. Here we show that the opioid antagonist methylnaltrexone (MNTX) enhances the effect of docetaxel (Doc) by blocking a cell growth-suppressive pathway. We found that PENK, which encodes opioid growth factor (OGF) and suppresses cell growth, is predominantly expressed in diffuse-type gastric cancers (GCs). The blockade of OGF signaling by MNTX releases cells from their arrest and boosts the effect of Doc. In comparison with the use of Doc alone, the combined use of Doc and MNTX significantly prolongs survival, alleviates abdominal pain, and diminishes Doc-resistant spheroids on the peritoneal membrane in model mice. These results suggest that blockade of the pathways that suppress cell growth may enhance the effects of anti-tumor drugs. PMID:25853862

  6. Convergent structural alterations define SWItch/Sucrose NonFermentable (SWI/SNF) chromatin remodeler as a central tumor suppressive complex in pancreatic cancer.

    PubMed

    Shain, A Hunter; Giacomini, Craig P; Matsukuma, Karen; Karikari, Collins A; Bashyam, Murali D; Hidalgo, Manuel; Maitra, Anirban; Pollack, Jonathan R

    2012-01-31

    Defining the molecular genetic alterations underlying pancreatic cancer may provide unique therapeutic insight for this deadly disease. Toward this goal, we report here an integrative DNA microarray and sequencing-based analysis of pancreatic cancer genomes. Notable among the alterations newly identified, genomic deletions, mutations, and rearrangements recurrently targeted genes encoding components of the SWItch/Sucrose NonFermentable (SWI/SNF) chromatin remodeling complex, including all three putative DNA binding subunits (ARID1A, ARID1B, and PBRM1) and both enzymatic subunits (SMARCA2 and SMARCA4). Whereas alterations of each individual SWI/SNF subunit occurred at modest-frequency, as mutational "hills" in the genomic landscape, together they affected at least one-third of all pancreatic cancers, defining SWI/SNF as a major mutational "mountain." Consistent with a tumor-suppressive role, re-expression of SMARCA4 in SMARCA4-deficient pancreatic cancer cell lines reduced cell growth and promoted senescence, whereas its overexpression in a SWI/SNF-intact line had no such effect. In addition, expression profiling analyses revealed that SWI/SNF likely antagonizes Polycomb repressive complex 2, implicating this as one possible mechanism of tumor suppression. Our findings reveal SWI/SNF to be a central tumor suppressive complex in pancreatic cancer.

  7. Loss of p53 Attenuates the Contribution of IL-6 Deletion on Suppressed Tumor Progression and Extended Survival in Kras-Driven Murine Lung Cancer

    PubMed Central

    Chen, Zhao; Zhang, Jishuai; Wang, Yanxiao; Chen, Jicheng; Li, Xiubin; Ye, Hui; Tang, Chuanhao; Cheng, Xuan; Hou, Ning; Yang, Xiao; Wong, Kwok-Kin

    2013-01-01

    Interleukin-6 (IL-6) is involved in lung cancer tumorigenesis, tumor progression, metastasis, and drug resistance. Previous studies show that blockade of IL-6 signaling can inhibit tumor growth and increase drug sensitivity in mouse models. Clinical trials in non-small cell lung cancer (NSCLC) reveal that IL-6 targeted therapy relieves NSCLC-related anemia and cachexia, although other clinical effects require further study. We crossed IL-6-/- mice with KrasG12D mutant mice, which develop lung tumors after activation of mutant KrasG12D, to investigate whether IL-6 inhibition contributes to tumor progression and survival time in vivo. KrasG12D; IL-6-/- mice exhibited increased tumorigenesis, but slower tumor growth and longer survival, than KrasG12D mice. Further, in order to investigate whether IL-6 deletion contributes to suppression of lung cancer metastasis, we generated KrasG12D; p53flox/flox; IL-6-/- mice, which developed lung cancer with a trend for reduced metastases and longer survival than KrasG12D; p53flox/flox mice. Tumors from KrasG12D; IL-6-/- mice showed increased expression of TNFα and decreased expression of CCL-19, CCL-20 and phosphorylated STAT3 (pSTAT3) than KrasG12D mice; however, these changes were not present between tumors from KrasG12D; p53flox/flox; IL-6-/- and KrasG12D; p53flox/flox mice. Upregulation of pSTAT3 and phosphorylated AKT (pAKT) were observed in KrasG12D tumors with p53 deletion. Taken together, these results indicate that IL-6 deletion accelerates tumorigenesis but delays tumor progression and prolongs survival time in a Kras-driven mouse model of lung cancer. However, these effects can be attenuated by p53 deletion. PMID:24260500

  8. Inhibition of PHLPP2/cyclin D1 protein translation contributes to the tumor suppressive effect of NFκB2 (p100).

    PubMed

    Xu, Jiawei; Wang, Yulei; Hua, Xiaohui; Xu, Jiheng; Tian, Zhongxian; Jin, Honglei; Li, Jingxia; Wu, Xue-Ru; Huang, Chuanshu

    2016-06-01

    Although the precursor protein of NFκB2 (p100) is thought to act as a tumor suppressor in mammalian cells, the molecular mechanism of its anti-tumor activity is far from clear. Here, we are, for the first time, to report that p100 protein expression was dramatically decreased in bladder cancers of N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN)-treated mice and human patients. Knockdown of p100 in cultured human bladder cancer cells promoted anchorage-independent growth accompanied with elevating abundance of cell-cycle-related proteins and accelerated cell-cycle progression. Above effects could be completely reversed by ectopically expression of p100, but not p52. Mechanistically, p100 inhibited Cyclin D1 protein translation by activating the transcription of LARP7 and its hosted miR-302d, which could directly bind to 3'-UTR of cyclin d1 mRNA and inhibited its protein translation. Furthermore, p100 suppressed the expression of PHLPP2 (PH domain and leucine-rich repeat protein phosphatases 2), thus promoting CREB phosphorylation at Ser133 and subsequently leading to miR-302d transcription. Taken together, our studies not only for the first time establish p100 as a key tumor suppressor of bladder cancer growth, but also identify a novel molecular cascade of PHLPP2/CREB/miR-302d that mediates the tumor suppressive function of p100. PMID:27095572

  9. CD151-α3β1 integrin complexes suppress ovarian tumor growth by repressing slug-mediated EMT and canonical Wnt signaling.

    PubMed

    Baldwin, Lauren A; Hoff, John T; Lefringhouse, Jason; Zhang, Michael; Jia, Changhe; Liu, Zeyi; Erfani, Sonia; Jin, Hongyan; Xu, Mei; She, Qing-Bai; van Nagell, John R; Wang, Chi; Chen, Li; Plattner, Rina; Kaetzel, David M; Luo, Jia; Lu, Michael; West, Dava; Liu, Chunming; Ueland, Fred R; Drapkin, Ronny; Zhou, Binhua P; Yang, Xiuwei H

    2014-12-15

    Human ovarian cancer is diagnosed in the late, metastatic stages but the underlying mechanisms remain poorly understood. We report a surprising functional link between CD151-α3β1 integrin complexes and the malignancy of serous-type ovarian cancer. Analyses of clinical specimens indicate that CD151 expression is significantly reduced or diminished in 90% of metastatic lesions, while it remains detectable in 58% of primary tumors. These observations suggest a putative tumor-suppressing role of CD151 in ovarian cancer. Indeed, our analyses show that knocking down CD151 or α3 integrin enhances tumor cell proliferation, growth and ascites production in nude mice. These changes are accompanied by impaired cell-cell contacts and aberrant expression of E-cadherin, Mucin 5AC and fibronectin, largely reminiscent of an epithelial to mesenchymal transition (EMT)-like change. Importantly, Slug, a master regulator of EMT, is markedly elevated. Knocking down Slug partially restores CD151-α3β1 integrin complex-dependent suppression of cell proliferation. Moreover, disruption of these adhesion protein complexes is accompanied by a concomitant activation of canonical Wnt signaling, including elevated levels of β-catenin and Axin-2 as well as resistance to the inhibition in β-catenin-dependent transcriptional complexes. Together, our study demonstrates that CD151-α3β1 integrin complexes regulate ovarian tumor growth by repressing Slug-mediated EMT and Wnt signaling. PMID:25356755

  10. Total alkaloids of Rubus alceifolius Poir inhibit tumor angiogenesis through suppression of the Notch signaling pathway in a mouse model of hepatocellular carcinoma.

    PubMed

    Zhao, Jinyan; Lin, Wei; Cao, Zhiyun; Zhuang, Qunchuan; Zheng, Liangpu; Peng, Jun; Hong, Zhenfeng

    2015-01-01

    Angiogenesis, which has a critical role in human tumor growth and development, is tightly regulated by the Notch signaling pathway. Total alkaloids are active components of the plant Rubus alceifolius Poir, which is used for the treatment of various types of cancer. A previous study by our group showed that the total alkaloids of Rubus alceifolius Poir (TARAP) induced hepatocellular carcinoma (HCC) cell apoptosis through the activation of the mitochondria-dependent pathway in vitro and in vivo, as well as inhibited angiogenesis in a chick embryo chorioallantoic membrane model. In the present study, to further analyze the specific mechanisms underlying the antitumor activity of TARAP, a HCC xenograft mouse model was used to assess the effect of TARAP on angiogenesis in vivo. TARAP was found to suppress the expression of vascular endothelial growth factor (VEGF) A and VEGF receptor-2 in tumor tissues, which resulted in the inhibition of tumor angiogenesis. In addition, TARAP treatment was observed to inhibit the expression of Notch1, delta-like ligand 4 and jagged 1, which are key mediators of the Notch signaling pathway. The present study identified that the inhibition of tumor angiogenesis through the suppression of the Notch signaling pathway may be one of the mechanisms through which TARAP may be effective in the treatment of cancer.

  11. CD151-α3β1 integrin complexes suppress ovarian tumor growth by repressing slug-mediated EMT and canonical Wnt signaling

    PubMed Central

    Zhang, Michael; Jia, Changhe; Liu, Zeyi; Erfani, Sonia; Jin, Hongyan; Xu, Mei; She, Qing-Bai; van Nagell, John R.; Wang, Chi; Chen, Li; Plattner, Rina; Kaetzel, David M.; Luo, Jia; Lu, Michael; West, Dava; Liu, Chunming; Ueland, Fred R.; Drapkin, Ronny; Zhou, Binhua P.; Yang, Xiuwei H.

    2014-01-01

    Human ovarian cancer is diagnosed in the late, metastatic stages but the underlying mechanisms remain poorly understood. We report a surprising functional link between CD151-α3β1 integrin complexes and the malignancy of serous-type ovarian cancer. Analyses of clinical specimens indicate that CD151 expression is significantly reduced or diminished in 90% of metastatic lesions, while it remains detectable in 58% of primary tumors. These observations suggest a putative tumor-suppressing role of CD151 in ovarian cancer. Indeed, our analyses show that knocking down CD151 or α3 integrin enhances tumor cell proliferation, growth and ascites production in nude mice. These changes are accompanied by impaired cell-cell contacts and aberrant expression of E-cadherin, Mucin 5AC and fibronectin, largely reminiscent of an epithelial to mesenchymal transition (EMT)-like change. Importantly, Slug, a master regulator of EMT, is markedly elevated. Knocking down Slug partially restores CD151-α3β1 integrin complex-dependent suppression of cell proliferation. Moreover, disruption of these adhesion protein complexes is accompanied by a concomitant activation of canonical Wnt signaling, including elevated levels of β-catenin and Axin-2 as well as resistance to the inhibition in β-catenin-dependent transcriptional complexes. Together, our study demonstrates that CD151-α3β1 integrin complexes regulate ovarian tumor growth by repressing Slug-mediated EMT and Wnt signaling. PMID:25356755

  12. The TLR7 agonist induces tumor regression both by promoting CD4+T cells proliferation and by reversing T regulatory cell-mediated suppression via dendritic cells

    PubMed Central

    Wang, Xiaofeng; Wu, Xiongyan; Chen, Xuehua; Li, Jianfang; Zhu, Zhenggang; Liu, Bingya; Su, Liping

    2015-01-01

    Treg-induced immunosuppression is now recognized as a key element in enabling tumors to escape immune-mediated destruction. Although topical TLR7 therapies such as imiquimod have been proved successful in the treatment of dermatological malignancy and a number of conditions beyond the FDA-approved indications, the mechanism behind the effect of TLR7 on effector T cell and Treg cell function in cancer immunosurveillance is still not well understood. Here, we found that Loxoribin, one of the TLR7 ligands, could inhibit tumor growth in xenograft models of colon cancer and lung cancer, and these anti-tumor effects of Loxoribin were mediated by promoting CD4+T cell proliferation and reversing Treg-mediated suppression via dendritic cells (DCs). However, deprivation of IL-6 using a neutralizing antibody abrogated the ability of Loxoribin-treated DCs, which reversed the Treg cell-mediated suppression. Furthermore, adoptive transfer of Loxoribin-treated DCs inhibited the tumor growth in vivo. Thus, this study links TLR7 signaling to the functional control of effector T cells and Treg cells and identifies Loxoribin as a new therapeutic strategy in cancer treatment, which may offer new opportunities to improve the outcome of cancer immunotherapy. PMID:25593198

  13. Inhibition of PHLPP2/cyclin D1 protein translation contributes to the tumor suppressive effect of NFκB2 (p100)

    PubMed Central

    Xu, Jiawei; Wang, Yulei; Hua, Xiaohui; Xu, Jiheng; Tian, Zhongxian; Jin, Honglei; Li, Jingxia; Wu, Xue-Ru; Huang, Chuanshu

    2016-01-01

    Although the precursor protein of NFκB2 (p100) is thought to act as a tumor suppressor in mammalian cells, the molecular mechanism of its anti-tumor activity is far from clear. Here, we are, for the first time, to report that p100 protein expression was dramatically decreased in bladder cancers of N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN)-treated mice and human patients. Knockdown of p100 in cultured human bladder cancer cells promoted anchorage-independent growth accompanied with elevating abundance of cell-cycle-related proteins and accelerated cell-cycle progression. Above effects could be completely reversed by ectopically expression of p100, but not p52. Mechanistically, p100 inhibited Cyclin D1 protein translation by activating the transcription of LARP7 and its hosted miR-302d, which could directly bind to 3′-UTR of cyclin d1 mRNA and inhibited its protein translation. Furthermore, p100 suppressed the expression of PHLPP2 (PH domain and leucine-rich repeat protein phosphatases 2), thus promoting CREB phosphorylation at Ser133 and subsequently leading to miR-302d transcription. Taken together, our studies not only for the first time establish p100 as a key tumor suppressor of bladder cancer growth, but also identify a novel molecular cascade of PHLPP2/CREB/miR-302d that mediates the tumor suppressive function of p100. PMID:27095572

  14. Over-expression of EphB3 enhances cell-cell contacts and suppresses tumor growth in HT-29 human colon cancer cells.

    PubMed

    Chiu, Sou-Tyau; Chang, King-Jen; Ting, Chen-Hung; Shen, Hsi-Che; Li, Hung; Hsieh, Fon-Jou

    2009-09-01

    Receptor tyrosine kinase EphB3 is expressed in cells in the bottom of intestinal crypts near stem cell niches. Loss of Ephb3 has recently been reported to produce invasive colorectal carcinoma in Apc(Min/+) mice and EphB-mediated compartmentalization was demonstrated to be a mechanism suppressing colorectal cancer progression; however, it is unknown whether other factors contribute to EphB-mediated tumor suppression. EphA4-ephrin-A and EphB4-ephrin-B2 signaling have been reported to promote mesenchymal-to-epithelial transition (MET). Here, we examine whether EphB3-ephrin-B interaction has a similar effect and investigate its role in tumor suppression. We found in a clinical cohort that EphB3 expression was significantly reduced in advanced Dukes' stage tumor specimens, so we over-expressed EphB3 in HT-29 cells by stable transfection. EphB3 over-expression inhibited HT-29 growth in monolayer cultures, anchorage-independent growth in soft agar and xenograft growth in nude mice and initiated morphological, behavioral and molecular changes consistent with MET. Specifically, EphB3 over-expression re-organized cytoskeleton (converting spreading cells to a cobble-like epithelial morphology, patterning cortical actin cytoskeleton and polarizing E-cadherin and ZO-1), induced functional changes favoring MET (decreased transwell migration, increased apoptosis and Ca(2+)-dependent cell-cell adhesion), decreased mesenchymal markers (fibronectin and nuclear beta-catenin), increased epithelial markers (ZO-1, E-cadherin and plakoglobin) and inactivated CrkL-Rac1, a known epithelial-to-mesenchymal transition signaling pathway. Additionally, cross talk from Wnt signaling potentiated the restoration of epithelial cell polarity. Noteworthily, the same factors contributing to MET, owing to EphB3 signaling, also facilitated tumor suppression. We conclude that EphB3-ephrin-B interaction promotes MET by re-establishing epithelial cell-cell junctions and such an MET-promoting effect

  15. Novel strategies for inhibiting PD-1 pathway-mediated immune suppression while simultaneously delivering activating signals to tumor-reactive T cells.

    PubMed

    Ostrand-Rosenberg, Suzanne; Horn, Lucas A; Alvarez, Juan A

    2015-10-01

    We previously developed cell-based vaccines as therapeutics for metastatic cancers. The vaccines were aimed at activating type I CD4(+)T cells and consisted of tumor cells transfected with genes encoding syngeneic MHC class II and CD80 costimulatory molecules, and lacking the MHC II-associated invariant chain. The vaccines showed some efficacy in mice with sarcoma, melanoma, and breast cancer and activated MHC class II syngeneic T cells from breast, lung, and melanoma patients. During the course of the vaccine studies, we observed that CD80 not only costimulated naïve T cells, but also bound to PD-L1 and prevented tumor cell-expressed PD-L1 from binding to its receptor PD-1 on activated T cells. A soluble form of CD80 (CD80-Fc) had the same effect and sustained IFNγ production by both human and murine PD-1(+) activated T cells in the presence of PD-L1(+) human or mouse tumor cells, respectively. In vitro studies with human tumor cells indicated that CD80-Fc was more effective than antibodies to either PD-1 or PD-L1 in sustaining T cell production of IFNγ. Additionally, in vivo studies with a murine tumor demonstrated that CD80-Fc was more effective than antibodies to PD-L1 in extending survival time. Studies with human T cells blocked for CD28 and with T cells from CD28 knockout mice demonstrated that CD80-Fc simultaneously inhibited PD-L1/PD-1-mediated immune suppression and delivered costimulatory signals to activated T cells, thereby amplifying T cell activation. These results suggest that CD80-Fc may be a useful monotherapy that minimizes PD-1 pathway immune suppression while simultaneously activating tumor-reactive T cells. PMID:25792524

  16. Trichostatin A modulates thiazolidinedione-mediated suppression of tumor necrosis factor α-induced lipolysis in 3T3-L1 adipocytes.

    PubMed

    Lu, Juu-Chin; Chang, Yu-Tzu; Wang, Chih-Tien; Lin, Yu-Chun; Lin, Chun-Ken; Wu, Zhong-Sheng

    2013-01-01

    In obesity, high levels of tumor necrosis factor α (TNFα) stimulate lipolysis in adipocytes, leading to hyperlipidemia and insulin resistance. Thiazolidinediones (TZDs), the insulin-sensitizing drugs, antagonize TNFα-induced lipolysis in adipocytes, thereby increasing insulin sensitivity in diabetes patients. The cellular target of TZDs is peroxisome proliferator-activated receptor γ (PPARγ), a nuclear receptor that controls many adipocyte functions. As a transcription factor, PPARγ is closely modulated by coregulators, which include coactivators and corepressors. Previous studies have revealed that in macrophages, the insulin-sensitizing effect of PPARγ may involve suppression of proinflammatory gene expression by recruiting the corepressor complex that contains corepressors and histone deacetylases (HDACs). Therefore, we investigated whether the corepressor complex is involved in TZD-mediated suppression of TNFα-induced lipolysis in 3T3-L1 adipocytes. Trichostatin A (TSA), a pan HDAC inhibitor (HDACI) that inhibits class I and II HDACs, was used to examine the involvement of HDACs in the actions of TZDs. TSA alone increased basal lipolysis and attenuated TZD-mediated suppression of TNFα-induced lipolysis. Increased basal lipolysis may in part result from class I HDAC inhibition because selective class I HDACI treatment had similar results. However, attenuation of TZD-mediated TNFα antagonism may be specific to TSA and related hydroxamate-based HDACI rather than to HDAC inhibition. Consistently, corepressor depletion did not affect TZD-mediated suppression. Interestingly, TSA treatment greatly reduced PPARγ levels in differentiated adipocytes. Finally, extracellular signal-related kinase 1/2 (ERK1/2) mediated TNFα-induced lipolysis, and TZDs suppressed TNFα-induced ERK phosphorylation. We determined that TSA increased basal ERK phosphorylation, and attenuated TZD-mediated suppression of TNFα-induced ERK phosphorylation, consistent with TSA's effects

  17. Tumor-suppressive microRNA-29 family inhibits cancer cell migration and invasion directly targeting LOXL2 in lung squamous cell carcinoma

    PubMed Central

    MIZUNO, KEIKO; SEKI, NAOHIKO; MATAKI, HIROKO; MATSUSHITA, RYOSUKE; KAMIKAWAJI, KAZUTO; KUMAMOTO, TOMOHIRO; TAKAGI, KOICHI; GOTO, YUSUKE; NISHIKAWA, RIKA; KATO, MAYUKO; ENOKIDA, HIDEKI; NAKAGAWA, MASAYUKI; INOUE, HIROMASA

    2016-01-01

    Lung cancer remains the most frequent cause of cancer-related death in developed countries. A recent molecular-targeted strategy has contributed to improvement of the remarkable effect of adenocarcinoma of the lung. However, such treatment has not been developed for squamous cell carcinoma (SCC) of the disease. Our recent studies of microRNA (miRNA) expression signatures of human cancers showed that the microRNA-29 family (miR-29a, miR-29b and miR-29c) significantly reduced cancer tissues compared to normal tissues. These findings suggest that miR-29s act as tumor-suppressors by targeting several oncogenic genes. The aim of the study was to investigate the functional significance of miR-29s in lung SCC and to identify miR-29s modulating molecular targets in lung SCC cells. Restoration of all mature members of the miR-29s inhibited cancer cell migration and invasion. Gene expression data combined in silico analysis and luciferase reporter assays demonstrated that the lysyl oxidase-like 2 (LOXL2) gene was a direct regulator of tumor-suppressive miR-29s. Moreover, overexpressed LOXL2 was confirmed in lung SCC clinical specimens, and silencing of LOXL2 inhibited cancer cell migration and invasion in lung SCC cell lines. Our present data suggested that loss of tumor-suppressive miR-29s enhanced cancer cell invasion in lung SCC through direct regulation of oncogenic LOXL2. Elucidation of the novel lung SCC molecular pathways and targets regulated by tumor-suppressive miR-29s will provide new insights into the potential mechanisms of oncogenesis and metastasis of the disease. PMID:26676674

  18. Tumor

    MedlinePlus

    ... plants (aflatoxins) Excessive sunlight exposure Genetic problems Obesity Radiation exposure Viruses Types of tumors known to be caused by viruses are: Cervical cancer (human papillomavirus) Hepatocellular carcinoma (hepatitis B and hepatitis C ...

  19. KLF17 empowers TGF-β/Smad signaling by targeting Smad3-dependent pathway to suppress tumor growth and metastasis during cancer progression

    PubMed Central

    Ali, A; Zhang, P; Liangfang, Y; Wenshe, S; Wang, H; Lin, X; Dai, Y; Feng, X-h; Moses, R; Wang, D; Li, X; Xiao, J

    2015-01-01

    Inhibition of tumor suppressive signaling is linked to cancer progression, metastasis and epithelial–mesenchymal transition (EMT). Transforming growth factor-β1 (TGF-β)/Smad signaling plays an important role in tumor suppression. Kruppel-like-factor 17 (KLF17) is a negative regulator of metastasis and EMT. However, underlying mechanisms leading to tumor suppressive and anti-metastatic function of KLF17 still remains unknown. Here, we show that KLF17 plays an integral role in potentiating TGF-β/Smad signaling via Smad3-dependent pathway to suppress tumor progression. Intriguingly, TGF-β/Smad3 signaling induces KLF17 expression, generating a positive feedback loop. TGF-β/Smad3–KLF17 loop is critical for anti-metastasis and tumor inhibition in cancer cells. Mechanistically, silencing KLF17 reduced Smad3–DNA complex formation on Smad binding element (SBE) and affects the expression of TGF-β/Smad target genes. Moreover, KLF17 alters Smad3 binding pattern on chromatin. KLF17 regulates TGF-β target genes that are Smad3-dependent. Smad3 and KLF17 physically interact with each other via KLF17 responsive elements/SBE region. Intriguingly, TGF-β stimulates the recruitment of KLF17 on chromatin to subsets of metastasis-associated genes. Functionally, depletion of KLF17 enhanced tumorigenic features in cancer cells. KLF17 is critical for full cytostatic function of TGF-β/Smad signaling. Clinically, KLF17 expression significantly decreases during advance HCC. KLF17 shows positive correlation with Smad3 levels in cancer samples. Our data shows that enhance KLF17 activity has important therapeutic implications for targeted-therapies aimed at TGF-β/Smad3 pathway. These findings define novel mechanism by which TGF-β/Smad–KLF17 pathway mutually affect each other during cancer metastasis, provide a new model of regulation of TGF-β/Smad signaling by KLF17 and defines new insights into anti-metastatic function of KLF17. PMID:25766320

  20. Hinokitiol inhibits cell growth through induction of S-phase arrest and apoptosis in human colon cancer cells and suppresses tumor growth in a mouse xenograft experiment.

    PubMed

    Lee, Youn-Sun; Choi, Kyeong-Mi; Kim, Wonkyun; Jeon, Young-Soo; Lee, Yong-Moon; Hong, Jin-Tae; Yun, Yeo-Pyo; Yoo, Hwan-Soo

    2013-12-27

    Hinokitiol (1), a tropolone-related natural compound, induces apoptosis and has anti-inflammatory, antioxidant, and antitumor activities. In this study, the inhibitory effects of 1 were investigated on human colon cancer cell growth and tumor formation of xenograft mice. HCT-116 and SW-620 cells derived from human colon cancers were found to be similarly susceptible to 1, with IC50 values of 4.5 and 4.4 μM, respectively. Compound 1 induced S-phase arrest in the cell cycle progression and decreased the expression levels of cyclin A, cyclin E, and Cdk2. Conversely, 1 increased the expression of p21, a Cdk inhibitor. Compound 1 decreased Bcl-2 expression and increased the expression of Bax, and cleaved caspase-9 and -3. The effect of 1 on tumor formation when administered orally was evaluated in male BALB/c-nude mice implanted intradermally separately with HCT-116 and SW-620 cells. Tumor volumes and tumor weights in the mice treated with 1 (100 mg/kg) were decreased in both cases. These results suggest that the suppression of tumor formation by compound 1 in human colon cancer may occur through cell cycle arrest and apoptosis.

  1. Combination radiofrequency (RF) ablation and IV liposomal heat shock protein suppression: Reduced tumor growth and increased animal endpoint survival in a small animal tumor model

    PubMed Central

    Yang, Wei; Ahmed, Muneeb; Tasawwar, Beenish; Levchenko, Tatynana; Sawant, Rupa R.; Torchilin, Vladimir; Goldberg, S. Nahum

    2012-01-01

    Background To investigate the effect of IV liposomal quercetin (a known down-regulator of heat shock proteins) alone and with liposomal doxorubicin on tumor growth and end-point survival when combined with radiofrequency (RF) tumor ablation in a rat tumor model. Methods Solitary subcutaneous R3230 mammary adenocarcinoma tumors (1.3–1.5 cm) were implanted in 48 female Fischer rats. Initially, 32 tumors (n=8, each group) were randomized into four experimental groups: (a) conventional monopolar RF alone (70°C for 5 min), (b) IV liposomal quercetin alone (1 mg/kg), (c) IV liposomal quercetin followed 24hr later with RF, and (d) no treatment. Next, 16 additional tumors were randomized into two groups (n=8, each) that received a combined RF and liposomal doxorubicin (15 min post-RF, 8 mg/kg) either with or without liposomal quercetin. Kaplan-Meier survival analysis was performed using a tumor diameter of 3.0 cm as the defined survival endpoint. Results Differences in endpoint survival and tumor doubling time among the groups were highly significant (P<0.001). Endpoint survivals were 12.5±2.2 days for the control group, 16.6±2.9 days for tumors treated with RF alone, 15.5±2.1days for tumors treated with liposomal quercetin alone, and 22.0±3.9 days with combined RF and quercetin. Additionally, combination quercetin/RF/doxorubicin therapy resulted in the longest survival (48.3±20.4 days), followed by RF/doxorubicin (29.9±3.8 days). Conclusions IV liposomal quercetin in combination with RF ablation reduces tumor growth rates and improves animal endpoint survival. Further increases in endpoint survival can be seen by adding an additional anti-tumor adjuvant agent liposomal doxorubicin. This suggests that targeting several post-ablation processes with multi-drug nanotherapies can increase overall ablation efficacy. PMID:22230341

  2. Ethanol extract of Chaenomeles speciosa Nakai induces apoptosis in cancer cells and suppresses tumor growth in mice

    PubMed Central

    YAO, GENDONG; LIU, CHAOQI; HUO, HONGQI; LIU, AIMIN; LV, BAIRUI; ZHANG, CAN; WANG, HAIDONG; LI, JINNONG; LIAO, LIANMING

    2013-01-01

    Chaenomeles speciosa Nakai is commonly used in traditional Chinese medicine for a variety of health-promoting effects. The present study aimed to investigate the antitumor effects of Chaenomeles speciosa Nakai. The tumor-inhibitory activity of the ethanol extract of Chaenomeles speciosa Nakai (EEC) was evaluated by in vitro growth assays of tumor cells and in vivo H22 tumor formation assays in mice. Mitochondrial membrane potential and DNA ladder assays were used to detect tumor cell apoptosis in the presence of EEC. To investigate the cellular targets of EEC, the immunomodulatory genes PD-L1, Foxp3 and TGF-β were detected in the tumor tissue using reverse transcription polymerase chain reaction (RT-PCR). Immune responses were determined by hemolysis and lymphocyte proliferation assays. EEC markedly inhibited the proliferation of the H22 cells in a dose-dependent manner. Moreover, it induced DNA fragmentation and decreased the mitochondrial membrane potential. In vivo, EEC inhibited tumor growth and enhanced the immune responses in mice, while the expression of PD-L1, Foxp3 and TGF-β was inhibited in the tumor tissue. These results provide the first evidence that EEC may inhibit tumor growth by directly killing tumor cells and enhancing immune function. Thus, it is a natural source for safe anticancer medicine. PMID:23946814

  3. Protein interacting with C kinase 1 suppresses invasion and anchorage-independent growth of astrocytic tumor cells

    PubMed Central

    Cockbill, Louisa M. R.; Murk, Kai; Love, Seth; Hanley, Jonathan G.

    2015-01-01

    Astrocytic tumors are the most common form of primary brain tumor. Astrocytic tumor cells infiltrate the surrounding CNS tissue, allowing them to evade removal upon surgical resection of the primary tumor. Dynamic changes to the actin cytoskeleton are crucial to cancer cell invasion, but the specific mechanisms that underlie the particularly invasive phenotype of astrocytic tumor cells are unclear. Protein interacting with C kinase 1 (PICK1) is a PDZ and BAR domain–containing protein that inhibits actin-related protein 2/3 (Arp2/3)-dependent actin polymerization and is involved in regulating the trafficking of a number of cell-surface receptors. Here we report that, in contrast to other cancers, PICK1 expression is down-regulated in grade IV astrocytic tumor cell lines and also in clinical cases of the disease in which grade IV tumors have progressed from lower-grade tumors. Exogenous expression of PICK1 in the grade IV astrocytic cell line U251 reduces their capacity for anchorage-independent growth, two-dimensional migration, and invasion through a three-dimensional matrix, strongly suggesting that low PICK1 expression plays an important role in astrocytic tumorigenesis. We propose that PICK1 negatively regulates neoplastic infiltration of astrocytic tumors and that manipulation of PICK1 is an attractive possibility for therapeutic intervention. PMID:26466675

  4. The lymphoma-associated NPM-ALK oncogene elicits a p16INK4a/pRb-dependent tumor-suppressive pathway.

    PubMed

    Martinelli, Paola; Bonetti, Paola; Sironi, Cristina; Pruneri, Giancarlo; Fumagalli, Caterina; Raviele, Paola Rafaniello; Volorio, Sara; Pileri, Stefano; Chiarle, Roberto; McDuff, Fiona Kate Elizabeth; Tusi, Betsabeh Khoramian; Turner, Suzanne D; Inghirami, Giorgio; Pelicci, Pier Giuseppe; Colombo, Emanuela

    2011-06-16

    Oncogene-induced senescence (OIS) is a barrier for tumor development. Oncogene-dependent DNA damage and activation of the ARF/p53 pathway play a central role in OIS and, accordingly, ARF and p53 are frequently mutated in human cancer. A number of leukemia/lymphoma-initiating oncogenes, however, inhibit ARF/p53 and only infrequently select for ARF or p53 mutations, suggesting the involvement of other tumor-suppressive pathways. We report that NPM-ALK, the initiating oncogene of anaplastic large cell lymphomas (ALCLs), induces DNA damage and irreversibly arrests the cell cycle of primary fibroblasts and hematopoietic progenitors. This effect is associated with inhibition of p53 and is caused by activation of the p16INK4a/pRb tumor-suppressive pathway. Analysis of NPM-ALK lymphomagenesis in transgenic mice showed p16INK4a-dependent accumulation of senescent cells in premalignant lesions and decreased tumor latency in the absence of p16INK4a. Accordingly, human ALCLs showed no expression of either p16INK4a or pRb. Up-regulation of the histone-demethylase Jmjd3 and de-methylation at the p16INK4a promoter contributed to the effect of NPM-ALK on p16INK4a, which was transcriptionally regulated. These data demonstrate that p16INK4a/pRb may function as an alternative pathway of oncogene-induced senescence, and suggest that the reactivation of p16INK4a expression might be a novel strategy to restore the senescence program in some tumors.

  5. Cat's whiskers tea (Orthosiphon stamineus) extract inhibits growth of colon tumor in nude mice and angiogenesis in endothelial cells via suppressing VEGFR phosphorylation.

    PubMed

    Ahamed, Mohamed B Khadeer; Aisha, Abdalrahim F A; Nassar, Zeyad D; Siddiqui, Jamshed M; Ismail, Z; Omari, S M S; Parish, C R; Majid, A M S Abdul

    2012-01-01

    Cat's whiskers (Orthosiphon stamineus) is commonly used as Java tea to treat kidney stones including a variety of angiogenesis-dependent diseases such as tumorous edema, rheumatism, diabetic blindness, and obesity. In the present study, antitumor potential of standardized 50% ethanol extract of O. stamineus leaves (EOS) was evaluated against colorectal tumor in athymic mice and antiangiogenic efficacy of EOS was investigated in human umbilical vein endothelial cells (HUVEC). EOS at 100 mg/kg caused 47.62 ± 6.4% suppression in tumor growth, while at 200 mg/kg it caused 83.39 ± 4.1% tumor regression. Tumor histology revealed significant reduction in extent of vascularization. Enzyme-linked immunosorbent assay showed EOS (200 mg/kg) significantly reduced the vascular endothelial growth factor (VEGF) level in vitro (211 ± 0.26 pg/ml cell lysate) as well as in vivo (90.9 ± 2 pg/g tissue homogenate) when compared to the control (378 ± 5 and 135.5 ± 4 pg, respectively). However, EOS was found to be noncytotoxic to colon cancer and endothelial cells. In vitro, EOS significantly inhibited the migration and tube formation of human umbilical vein endothelial cells (HUVECs). EOS suppressed VEGF-induced phosphorylation of VEGF receptor-2 in HUVECs. High performance liquid chromatography (HPLC) analysis of EOS showed high rosmarinic acid contents, whereas phytochemical analysis revealed high protein and phenolic contents. These results demonstrated that the antitumor activity of EOS may be due to its VEGF-targeted antiangiogenicity.

  6. Inhibiting oncogenic signaling by sorafenib activates PUMA via GSK3β and NF-κB to suppress tumor cell growth.

    PubMed

    Dudgeon, C; Peng, R; Wang, P; Sebastiani, A; Yu, J; Zhang, L

    2012-11-15

    Aberrant Ras/Raf/MEK/ERK signaling is one of the most prevalent oncogenic alterations and confers survival advantage to tumor cells. Inhibition of this pathway can effectively suppress tumor cell growth. For example, sorafenib, a multi-kinase inhibitor targeting c-Raf and other oncogenic kinases, has been used clinically for treating advanced liver and kidney tumors, and also has shown efficacy against other malignancies. However, how inhibition of oncogenic signaling by sorafenib and other drugs suppresses tumor cell growth remains unclear. In this study, we found that sorafenib kills cancer cells by activating PUMA (p53-upregulated modulator of apoptosis), a p53 target and a BH3-only Bcl-2 family protein. Sorafenib treatment induces PUMA in a variety of cancer cells irrespective of their p53 status. Surprisingly, the induction of PUMA by sorafenib is mediated by IκB-independent activation of nuclear factor (NF)-κB, which directly binds to the PUMA promoter to activate its transcription. NF-κB activation by sorafenib requires glycogen synthase kinase 3β activation, subsequent to ERK inhibition. Deficiency in PUMA abrogates sorafenib-induced apoptosis and caspase activation, and renders sorafenib resistance in colony formation and xenograft tumor assays. Furthermore, the chemosensitization effect of sorafenib is dependent on PUMA, and involves concurrent PUMA induction through different pathways. BH3 mimetics potentiate the anti-cancer effects of sorafenib, and restore sorafenib sensitivity in resistant cells. Together, these results demonstrate a key role of PUMA-dependent apoptosis in therapeutic inhibition of Ras/Raf/MEK/ERK signaling. They provide a rationale for manipulating the apoptotic machinery to improve sensitivity and overcome resistance to the therapies that target oncogenic kinase signaling.

  7. Novel retinoblastoma mutation abrogating the interaction to E2F2/3, but not E2F1, led to selective suppression of thyroid tumors

    PubMed Central

    Toki, Hideaki; Inoue, Maki; Minowa, Osamu; Motegi, Hiromi; Saiki, Yuriko; Wakana, Shigeharu; Masuya, Hiroshi; Gondo, Yoichi; Shiroishi, Toshihiko; Yao, Ryoji; Noda, Tetsuo

    2014-01-01

    Mutant mouse models are indispensable tools for clarifying gene functions and elucidating the pathogenic mechanisms of human diseases. Here, we describe novel cancer models bearing point mutations in the retinoblastoma gene (Rb1) generated by N-ethyl-N-nitrosourea mutagenesis. Two mutations in splice sites reduced Rb1 expression and led to a tumor spectrum and incidence similar to those observed in the conventional Rb1 knockout mice. The missense mutant, Rb1D326V/+, developed pituitary tumors, but thyroid tumors were completely suppressed. Immunohistochemical analyses of thyroid tissue revealed that E2F1, but not E2F2/3, was selectively inactivated, indicating that the mutant Rb protein (pRb) suppressed thyroid tumors by inactivating E2F1. Interestingly, Rb1D326V/+ mice developed pituitary tumors that originated from the intermediate lobe of the pituitary, despite selective inactivation of E2F1. Furthermore, in the anterior lobe of the pituitary, other E2F were also inactivated. These observations show that pRb mediates the inactivation of E2F function and its contribution to tumorigenesis is highly dependent on the cell type. Last, by using a reconstitution assay of synthesized proteins, we showed that the D326V missense pRb bound to E2F1 but failed to interact with E2F2/3. These results reveal the effect of the pRb N-terminal domain on E2F function and the impact of the protein on tumorigenesis. Thus, this mutant mouse model can be used to investigate human Rb family-bearing mutations at the N-terminal region. PMID:25088905

  8. Nitric oxide suppresses tumor cell migration through N-Myc downstream-regulated gene-1 (NDRG1) expression: role of chelatable iron.

    PubMed

    Hickok, Jason R; Sahni, Sumit; Mikhed, Yuliya; Bonini, Marcelo G; Thomas, Douglas D

    2011-12-01

    N-Myc downstream-regulated gene 1 (NDRG1) is a ubiquitous cellular protein that is up-regulated under a multitude of stress and growth-regulatory conditions. Although the exact cellular functions of this protein have not been elucidated, mutations in this gene or aberrant expression of this protein have been linked to both tumor suppressive and oncogenic phenotypes. Previous reports have demonstrated that NDRG1 is strongly up-regulated by chemical iron chelators and hypoxia, yet its regulation by the free radical nitric oxide ((•)NO) has never been demonstrated. Herein, we examine the chemical biology that confers NDRG1 responsiveness at the mRNA and protein levels to (•)NO. We demonstrate that the interaction of (•)NO with the chelatable iron pool (CIP) and the appearance of dinitrosyliron complexes (DNIC) are key determinants. Using HCC 1806 triple negative breast cancer cells, we find that NDRG1 is up-regulated by physiological (•)NO concentrations in a dose- and time-dependant manner. Tumor cell migration was suppressed by NDRG1 expression and we excluded the involvement of HIF-1α, sGC, N-Myc, and c-Myc as upstream regulatory targets of (•)NO. Augmenting the chelatable iron pool abolished (•)NO-mediated NDRG1 expression and the associated phenotypic effects. These data, in summary, reveal a link between (•)NO, chelatable iron, and regulation of NDRG1 expression and signaling in tumor cells.

  9. A novel type of cellular senescence that can be enhanced in mouse models and human tumor xenografts to suppress prostate tumorigenesis

    PubMed Central

    Alimonti, Andrea; Nardella, Caterina; Chen, Zhenbang; Clohessy, John G.; Carracedo, Arkaitz; Trotman, Lloyd C.; Cheng, Ke; Varmeh, Shohreh; Kozma, Sara C.; Thomas, George; Rosivatz, Erika; Woscholski, Rudiger; Cognetti, Francesco; Scher, Howard I.; Pandolfi, Pier Paolo

    2010-01-01

    Irreversible cell growth arrest, a process termed cellular senescence, is emerging as an intrinsic tumor suppressive mechanism. Oncogene-induced senescence is thought to be invariably preceded by hyperproliferation, aberrant replication, and activation of a DNA damage checkpoint response (DDR), rendering therapeutic enhancement of this process unsuitable for cancer treatment. We previously demonstrated in a mouse model of prostate cancer that inactivation of the tumor suppressor phosphatase and tensin homolog deleted on chromosome 10 (Pten) elicits a senescence response that opposes tumorigenesis. Here, we show that Pten-loss–induced cellular senescence (PICS) represents a senescence response that is distinct from oncogene-induced senescence and can be targeted for cancer therapy. Using mouse embryonic fibroblasts, we determined that PICS occurs rapidly after Pten inactivation, in the absence of cellular proliferation and DDR. Further, we found that PICS is associated with enhanced p53 translation. Consistent with these data, we showed that in mice p53-stabilizing drugs potentiated PICS and its tumor suppressive potential. Importantly, we demonstrated that pharmacological inhibition of PTEN drives senescence and inhibits tumorigenesis in vivo in a human xenograft model of prostate cancer. Taken together, our data identify a type of cellular senescence that can be triggered in nonproliferating cells in the absence of DNA damage, which we believe will be useful for developing a “pro-senescence” approach for cancer prevention and therapy. PMID:20197621

  10. SPARC Expression Is Selectively Suppressed in Tumor Initiating Urospheres Isolated from As+3- and Cd+2-Transformed Human Urothelial Cells (UROtsa) Stably Transfected with SPARC

    PubMed Central

    Slusser-Nore, Andrea; Larson-Casey, Jennifer L.; Zhang, Ruowen; Zhou, Xu Dong; Somji, Seema; Garrett, Scott H.; Sens, Donald A.; Dunlevy, Jane R.

    2016-01-01

    Background This laboratory previously analyzed the expression of SPARC in the parental UROtsa cells, their arsenite (As+3) and cadmium (Cd+2)-transformed cell lines, and tumor transplants generated from the transformed cells. It was demonstrated that SPARC expression was down-regulated to background levels in Cd+2-and As+3-transformed UROtsa cells and tumor transplants compared to parental cells. In the present study, the transformed cell lines were stably transfected with a SPARC expression vector to determine the effect of SPARC expression on the ability of the cells to form tumors in immune-compromised mice. Methods Real time PCR, western blotting, immunohistochemistry, and immunofluorescence were used to define the expression of SPARC in the As+3-and Cd+2-transformed cell lines, and urospheres isolated from these cell lines, following their stable transfection with an expression vector containing the SPARC open reading frame (ORF). Transplantation of the cultured cells into immune-compromised mice by subcutaneous injection was used to assess the effect of SPARC expression on tumors generated from the above cell lines and urospheres. Results It was shown that the As+3-and Cd+2-transformed UROtsa cells could undergo stable transfection with a SPARC expression vector and that the transfected cells expressed both SPARC mRNA and secreted protein. Tumors formed from these SPARC-transfected cells were shown to have no expression of SPARC. Urospheres isolated from cultures of the SPARC-transfected As+3-and Cd+2-transformed cell lines were shown to have only background expression of SPARC. Urospheres from both the non-transfected and SPARC-transfected cell lines were tumorigenic and thus fit the definition for a population of tumor initiating cells. Conclusions Tumor initiating cells isolated from SPARC-transfected As+3-and Cd+2-transformed cell lines have an inherent mechanism to suppress the expression of SPARC mRNA. PMID:26783756

  11. Myeloid zinc-finger 1 (MZF-1) suppresses prostate tumor growth through enforcing ferroportin-conducted iron egress.

    PubMed

    Chen, Y; Zhang, Z; Yang, K; Du, J; Xu, Y; Liu, S

    2015-07-01

    Although previous studies suggest that myeloid zinc-finger 1 (MZF-1) is a multifaceted transcription factor that may function as either an oncogene or a tumor suppressor, the molecular bases determining its different traits remain elusive. Increasing evidence suggests that disorders in iron metabolism affect tumorigenesis and tumor behaviors, and that excess tumor iron stimulates tumor progression through various mechanisms such as enhancing DNA replication and energy metabolism. Ferroportin (FPN) is the only known iron exporter in mammalian cells, and it determines global iron egress out of cells. FPN reduction leads to decreased iron efflux and increased intracellular iron that consequentially aggravates the oncogenic effects of iron. MZF-1 was recently identified as a transcription factor that regulates FPN expression. Thus far, however, the molecular mechanisms underlying the MZF-1-FPN signaling in cancers are largely unknown. Here, we found a significant reduction of FPN levels in prostate tumors relative to adjacent tissues, and demonstrated a crucial role of FPN in tumor growth through controlling tumor iron concentration. Inhibition of MZF-1 expression led to reduced FPN concentration, coupled with resultant intracellular iron retention, increased iron-related cellular activities and enhanced tumor cell growth. In contrast, increase of MZF-1 expression restrained tumor cell growth by promoting FPN-driven iron egress. Importantly, we demonstrated that AP4 and c-Myb jointly modulated MZF-1 transcription, and that miR-492 was also directly involved in regulating MZF-1 concentration through binding to the 3' untranslated regions of its mRNA. These results correlate with reduced AP4 and c-Myb expression and elevated miR-492 expression found in prostate tumors as compared with adjacent tissues that resulted in diminished MZF-1 and FPN. Moreover, we demonstrated that alterations of AP4, c-Myb and miR-492 levels significantly affected tumor cell growth. Targeting

  12. Tumor-suppressive microRNA-29 family inhibits cancer cell migration and invasion directly targeting LOXL2 in lung squamous cell carcinoma.

    PubMed

    Mizuno, Keiko; Seki, Naohiko; Mataki, Hiroko; Matsushita, Ryosuke; Kamikawaji, Kazuto; Kumamoto, Tomohiro; Takagi, Koichi; Goto, Yusuke; Nishikawa, Rika; Kato, Mayuko; Enokida, Hideki; Nakagawa, Masayuki; Inoue, Hiromasa

    2016-02-01

    Lung cancer remains the most frequent cause of cancer-related death in developed countries. A recent molecular-targeted strategy has contributed to improvement of the remarkable effect of adenocarcinoma of the lung. However, such treatment has not been developed for squamous cell carcinoma (SCC) of the disease. Our recent studies of microRNA (miRNA) expression signatures of human cancers showed that the microRNA-29 family (miR‑29a, miR‑29b and miR‑29c) significantly reduced cancer tissues compared to normal tissues. These findings suggest that miR‑29s act as tumor-suppressors by targeting several oncogenic genes. The aim of the study was to investigate the functional significance of miR‑29s in lung SCC and to identify miR‑29s modulating molecular targets in lung SCC cells. Restoration of all mature members of the miR‑29s inhibited cancer cell migration and invasion. Gene expression data combined in silico analysis and luciferase reporter assays demonstrated that the lysyl oxidase-like 2 (LOXL2) gene was a direct regulator of tumor‑suppressive miR‑29s. Moreover, overexpressed LOXL2 was confirmed in lung SCC clinical specimens, and silencing of LOXL2 inhibited cancer cell migration and invasion in lung SCC cell lines. Our present data suggested that loss of tumor-suppressive miR‑29s enhanced cancer cell invasion in lung SCC through direct regulation of oncogenic LOXL2. Elucidation of the novel lung SCC molecular pathways and targets regulated by tumor-suppressive miR‑29s will provide new insights into the potential mechanisms of oncogenesis and metastasis of the disease.

  13. A phosphomimetic mutant of RelA/p65 at Ser536 induces apoptosis and senescence: An implication for tumor-suppressive role of Ser536 phosphorylation.

    PubMed

    Bu, Yiwen; Li, Xiaoning; He, Yingchun; Huang, Chenfei; Shen, Yi; Cao, Yu; Huang, Dan; Cai, Chuan; Wang, Yuhong; Wang, Ziqi; Liao, Duan-Fang; Cao, Deliang

    2016-03-01

    Hundreds of NF-κB inhibitors have been developed for cancer therapy, but their clinical efficacy is unsatisfactory. Here we show that the phosphorylation activation at Ser536 of RelA/p65 protein, a main subunit in the NF-κB family, may play a tumor-suppressive role. In normal colon mucosa, RelA/p65 phosphorylation at Ser536 was increasingly increased with the maturation and apoptotic shedding of epithelial cells, but the phosphorylation at Ser536 was decreased in colon cancer. In colon (HCT116 p53 wt and p53 -/-), breast (MCF7), and prostate (LNCaP and DU145) cancer cells, a phosphomimetic mutation of RelA/p65 at Ser536 (named p65/S536D) triggered dramatic apoptosis through affecting expression of a wide range of cell death/survival genes, such as Bim, Puma, Noxa, Bcl-2 and survivin. In HCT116 cells, p65/S536D mutant upregulated Fas, insulted mitochondrial membrane potential, and triggered cleavage and activation of caspase-3, 7, 8 and 9. A FasL neutralizing antibody (NOK1) prevented cell death induced by the p65/S536D. A pan inhibitor of caspases, Z-VAD-FMK (20 μM), blocked caspase-mediated mitochondrial membrane depolarization. This p65/S536D also triggered senescence in HCT116 cells through a p16-dependent pathway, but not in MFC7 due to lack of p16. Intratumoral delivery of the p65/S536D effectively suppressed tumor growth in nude mice. Together our data suggest that the phosphorylation of RelA/p65 at Ser536 may confer it a tumor-suppressive role by inducing apoptosis and senescence, highlighting the importance of discriminating the function and active status of individual active sites in RelA/p65 when NF-κB inhibitors are considered for targeted therapy of cancer.

  14. Suppression of tumor necrosis factor receptor-associated protein 1 expression induces inhibition of cell proliferation and tumor growth in human esophageal cancer cells.

    PubMed

    Tian, Xin; Ma, Ping; Sui, Cheng-Guang; Meng, Fan-Dong; Li, Yan; Fu, Li-Ye; Jiang, Tao; Wang, Yang; Jiang, You-Hong

    2014-06-01

    Tumor necrosis factor receptor-associated protein 1 (TRAP1) is a molecular chaperone involved in multidrug resistance and antiapoptosis in some human tumors, but its regulatory mechanisms have not been revealed in esophageal squamous cell carcinoma (ESCC). In this study, 138 specimens of ESCC were analyzed. TRAP1 was overexpressed in ESCC, particularly in poorly differentiated tumors. To further explore the molecular regulatory mechanism, we constructed specific small interfering RNA-expressing vectors targeting Trap1, and knocked down Trap1 expression in the esophageal cancer cell lines ECA109 and EC9706. Knockdown of Trap1 induced increases in reactive oxygen species and mitochondrial depolarization, which have been proposed as critical regulators of apoptosis. The cell cycle was arrested in G2/M phase, and in vitro inhibition of cell proliferation was confirmed with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide and bromodeoxyuridine assays. Furthermore, re-expression of TRAP1 in Trap1 small interfering RNA-transfected ESCC cells restored cell proliferation and cell apoptosis. Bioluminescence of subcutaneously xenografted ESCC tumor cells demonstrated significant inhibition of in vivo tumor growth by Trap1 knockdown. This study shows that TRAP1 was overexpressed in most patients with ESCC, and caused an increase in antiapoptosis potency. TRAP1 may be regarded as a target in ESCC biotherapy.

  15. Both p53-PUMA/NOXA-Bax-mitochondrion and p53-p21cip1 pathways are involved in the CDglyTK-mediated tumor cell suppression

    SciTech Connect

    Yu, Zhendong; Wang, Hao; Zhang, Libin; Tang, Aifa; Zhai, Qinna; Wen, Jianxiang; Yao, Li; Li, Pengfei

    2009-09-04

    CDglyTK fusion suicide gene has been well characterized to effectively kill tumor cells. However, the exact mechanism and downstream target genes are not fully understood. In our study, we found that CDglyTK/prodrug treatment works more efficiently in p53 wild-type (HONE1) cells than in p53 mutant (CNE1) cells. We then used adenovirus-mediated gene delivery system to either knockdown or overexpress p53 and its target genes in these cells. Consistent results showed that both p53-PUMA/NOXA/Bcl2-Bax and p53-p21 pathways contribute to the CDglyTK induced tumor cell suppression. Our work for the first time addressed the role of p53 related genes in the CDglyTK/prodrug system.

  16. Borage oil reduction of rheumatoid arthritis activity may be mediated by increased cAMP that suppresses tumor necrosis factor-alpha.

    PubMed

    Kast, R E

    2001-11-01

    Recent double blind studies have shown some benefit of borage oil in treatment of rheumatoid arthritis. Tumor necrosis factor-alpha has been shown to be a central mediator of inflammatory and joint destructive processes in rheumatoid arthritis. In this paper, evidence from published research is reviewed that indicates gamma linolenic acid component of borage oil increases prostaglandin E levels that increase cAMP levels that in turn suppress tumor necrosis factor-alpha synthesis. If this biochemical path of borage oil is correct then (1) concomitant non-steroidal anti-inflammatory drug use would tend to undermine borage oil effects, and (2) borage oil would be contraindicated in pregnancy given the teratogenic and labor inducing effects of prostaglandin E agonists. PMID:11710548

  17. Co-delivery of doxorubicin and tumor-suppressing p53 gene using a POSS-based star-shaped polymer for cancer therapy.

    PubMed

    Li, Yongmao; Xu, Bing; Bai, Tao; Liu, Wenguang

    2015-07-01

    In this work, a star-shaped polymer consisting of a cationic poly[2-(dimethylamino) ethyl methacrylate] (PDMAEMA) shell and a zwitterionic poly[N-(3-(methacryloylamino) propyl)-N,N-dimethyl-N-(3-sulfopropyl) ammonium hydroxide] (PMPD) corona was grafted from a polyhedral oligomeric silsesquioxanes (POSS)-based initiator via atomic transfer radical polymerization (ATRP). The reported star-shaped polymer could form stable micelles in aqueous solutions even in the presence of serum. In addition, anti-cancer drug doxorubicin and tumor-suppressing p53 gene were loaded in the process of micelle formation. The formed polyplex was biocompatible and highly efficient for both drug and gene delivery. Furthermore, the polyplex was able to cause a high apoptotic rate of tumor cells both in vitro and in vivo. This combination delivery strategy offers a promising method for cancer therapy and can be used for further clinical applications. PMID:25934448

  18. Borage oil reduction of rheumatoid arthritis activity may be mediated by increased cAMP that suppresses tumor necrosis factor-alpha.

    PubMed

    Kast, R E

    2001-11-01

    Recent double blind studies have shown some benefit of borage oil in treatment of rheumatoid arthritis. Tumor necrosis factor-alpha has been shown to be a central mediator of inflammatory and joint destructive processes in rheumatoid arthritis. In this paper, evidence from published research is reviewed that indicates gamma linolenic acid component of borage oil increases prostaglandin E levels that increase cAMP levels that in turn suppress tumor necrosis factor-alpha synthesis. If this biochemical path of borage oil is correct then (1) concomitant non-steroidal anti-inflammatory drug use would tend to undermine borage oil effects, and (2) borage oil would be contraindicated in pregnancy given the teratogenic and labor inducing effects of prostaglandin E agonists.

  19. High Potency VEGFRs/MET/FMS Triple Blockade by TAS-115 Concomitantly Suppresses Tumor Progression and Bone Destruction in Tumor-Induced Bone Disease Model with Lung Carcinoma Cells

    PubMed Central

    Fujioka, Yayoi; Kataoka, Yuki; Tanaka, Kenji; Hashimoto, Akihiro; Suzuki, Takamasa; Ito, Kenjiro; Haruma, Tomonori; Yamamoto-Yokoi, Hiromi; Harada, Naomoto; Sakuragi, Motomu; Oda, Nobuyuki; Matsuo, Kenichi; Inada, Masaki; Yonekura, Kazuhiko

    2016-01-01

    Approximately 25–40% of patients with lung cancer show bone metastasis. Bone modifying agents reduce skeletal-related events (SREs), but they do not significantly improve overall survival. Therefore, novel therapeutic approaches are urgently required. In this study, we investigated the anti-tumor effect of TAS-115, a VEGFRs and HGF receptor (MET)-targeted kinase inhibitor, in a tumor-induced bone disease model. A549-Luc-BM1 cells, an osteo-tropic clone of luciferase-transfected A549 human lung adenocarcinoma cells (A549-Luc), produced aggressive bone destruction associated with tumor progression after intra-tibial (IT) implantation into mice. TAS-115 significantly reduced IT tumor growth and bone destruction. Histopathological analysis showed a decrease in tumor vessels after TAS-115 treatment, which might be mediated through VEGFRs inhibition. Furthermore, the number of osteoclasts surrounding the tumor was decreased after TAS-115 treatment. In vitro studies demonstrated that TAS-115 inhibited HGF-, VEGF-, and macrophage-colony stimulating factor (M-CSF)-induced signaling pathways in osteoclasts. Moreover, TAS-115 inhibited Feline McDonough Sarcoma oncogene (FMS) kinase, as well as M-CSF and receptor activator of NF-κB ligand (RANKL)-induced osteoclast differentiation. Thus, VEGFRs/MET/FMS-triple inhibition in osteoclasts might contribute to the potent efficacy of TAS-115. The fact that concomitant dosing of sunitinib (VEGFRs/FMS inhibition) with crizotinib (MET inhibition) exerted comparable inhibitory efficacy for bone destruction to TAS-115 also supports this notion. In conclusion, TAS-115 inhibited tumor growth via VEGFR-kinase blockade, and also suppressed bone destruction possibly through VEGFRs/MET/FMS-kinase inhibition, which resulted in potent efficacy of TAS-115 in an A549-Luc-BM1 bone disease model. Thus, TAS-115 shows promise as a novel therapy for lung cancer patients with bone metastasis. PMID:27736957

  20. Dietary gamma-linolenate attenuates tumor growth in a rodent model of prostatic adenocarcinoma via suppression of elevated generation of PGE(2) and 5S-HETE.

    PubMed

    Pham, Hung; Vang, Kao; Ziboh, Vincent A

    2006-04-01

    Prostate cancer poses considerable threat to the aging male population as it has become a leading cause of cancer death to this group. Due to the complexity of this age-related disease, the mechanism(s) and factors resulting in prostate cancer remain unclear. Reports showing an increase risk in prostatic cancer with increasing dietary fat are contrasted by other studies suggesting the beneficial effects of certain polyunsaturated fatty acid (PUFA) in the modulation of tumor development. The n-6 PUFA, gamma-linolenic acid (GLA), has been shown to suppress tumor growth in vitro. Therefore, using the Lobund-Wistar (L-W) rat model of prostate cancer, we tested the hypothesis whether dietary supplementation of GLA could suppress tumor growth and development in vivo. Prostatic adenocarcinomas were induced in two groups of L-W rats, the experimental group (N-nitroso-N-methylurea, NMU/testosterone propionate, TP) and the GLA group (NMU/TP/GLA fed) undergoing similar treatment but fed a purified diet supplemented with GLA. Our findings revealed a decrease in prostate growth in the NMU/TP/GLA-fed group as determined by weight, tissue size, DNA content and prostate-specific antigen (tumor marker of prostate cancer). Comparison between the two groups showed a significant increase in 5S-hydroxyeicosatetraenoic acid and prostaglandin E(2) in the NMU/TP group. These increases paralleled the increased protein expression and activity of cyclooxygenase-2 as well as increased activity of 5-lipoxygenase. Taken together, the findings showed that intake of GLA-enriched diet does reduce prostatic cancer development in L-W rats and could serve as a non-toxic adjunct in management of human prostatic cancer. PMID:16567086

  1. Suppression of Tumor Growth by Pleurotus ferulae Ethanol Extract through Induction of Cell Apoptosis, and Inhibition of Cell Proliferation and Migration

    PubMed Central

    Wang, Weilan; Chen, Kaixu; Liu, Qing; Johnston, Nathan; Ma, Zhenghai; Zhang, Fuchun; Zheng, Xiufen

    2014-01-01

    Cancer is the second leading cause of death worldwide. Edible medicinal mushrooms have been used in traditional medicine as regimes for cancer patients. Recently anti-cancer bioactive components from some mushrooms have been isolated and their anti-cancer effects have been tested. Pleurotus ferulae, a typical edible medicinal mushroom in Xinjiang China, has also been used to treat cancer patients in folk medicine. However, little studies have been reported on the anti-cancer components of Pleurotus ferulae. This study aims to extract bioactive components from Pleurotus ferulae and to investigate the anti-cancer effects of the extracts. We used ethanol to extract anti-cancer bioactive components enriched with terpenoids from Pleurotus ferulae. We tested the anti-tumour effects of ethanol extracts on the melanoma cell line B16F10, the human gastric cancer cell line BGC 823 and the immortalized human gastric epithelial mucosa cell line GES-1 in vitro and a murine melanoma model in vivo. Cell toxicity and cell proliferation were measured by MTT assays. Cell cycle progression, apoptosis, caspase 3 activity, mitochondrial membrane potential (MMP), migration and gene expression were studied in vitro. PFEC suppressed tumor cell growth, inhibited cell proliferation, arrested cells at G0/G1 phases and was not toxic to non-cancer cells. PFEC also induced cell apoptosis and necrosis, increased caspase 3 activity, reduced the MMP, prevented cell invasion and changed the expression of genes associated with apoptosis and the cell cycle. PFEC delayed tumor formation and reduced tumor growth in vivo. In conclusion, ethanol extracted components from Pleurotus ferulae exert anti-cancer effects through direct suppression of tumor cell growth and invasion, demonstrating its therapeutic potential in cancer treatment. PMID:25029345

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

    PubMed

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

    2016-09-01

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

  3. CO2 bubbling-based 'Nanobomb' System for Targetedly Suppressing Panc-1 Pancreatic Tumor via Low Intensity Ultrasound-activated Inertial Cavitation.

    PubMed

    Zhang, Kun; Xu, Huixiong; Chen, Hangrong; Jia, Xiaoqing; Zheng, Shuguang; Cai, Xiaojun; Wang, Ronghui; Mou, Juan; Zheng, Yuanyi; Shi, Jianlin

    2015-01-01

    Noninvasive and targeted physical treatment is still desirable especially for those cancerous patients. Herein, we develop a new physical treatment protocol by employing CO2 bubbling-based 'nanobomb' system consisting of low-intensity ultrasound (1.0 W/cm(2)) and a well-constructed pH/temperature dual-responsive CO2 release system. Depending on the temperature elevation caused by exogenous low-intensity therapeutic ultrasound irradiation and the low pH caused by the endogenous acidic-environment around/within tumor, dual-responsive CO2 release system can quickly release CO2 bubbles, and afterwards, the generated CO2 bubbles waves will timely explode before dissolution due to triggering by therapeutic ultrasound waves. Related bio-effects (e.g., cavitation, mechanical, shock waves, etc) caused by CO2 bubbles' explosion effectively induce instant necrosis of panc-1 cells and blood vessel destruction within panc-1 tumor, and consequently inhibit the growth of panc-1 solid tumor, simultaneously minimizing the side effects to normal organs. This new physiotherapy employing CO2 bubbling-based 'nanobomb' system promises significant potentials in targetedly suppressing tumors, especially for those highly deadly cancers.

  4. Sulindac selectively inhibits colon tumor cell growth by activating the cGMP/PKG pathway to suppress Wnt/β-catenin signaling.

    PubMed

    Li, Nan; Xi, Yaguang; Tinsley, Heather N; Gurpinar, Evrim; Gary, Bernard D; Zhu, Bing; Li, Yonghe; Chen, Xi; Keeton, Adam B; Abadi, Ashraf H; Moyer, Mary P; Grizzle, William E; Chang, Wen-Chi; Clapper, Margie L; Piazza, Gary A

    2013-09-01

    Nonsteroidal anti-inflammatory drugs (NSAID) display promising antineoplastic activity for colorectal and other cancers, but toxicity from COX inhibition limits their long-term use for chemoprevention. Previous studies have concluded that the basis for their tumor cell growth inhibitory activity does not require COX inhibition, although the underlying mechanism is poorly understood. Here, we report that the NSAID sulindac sulfide inhibits cyclic guanosine 3',5'-monophosphate phosphodiesterase (cGMP PDE) activity to increase intracellular cGMP levels and activate cGMP-dependent protein kinase (PKG) at concentrations that inhibit proliferation and induce apoptosis of colon tumor cells. Sulindac sulfide did not activate the cGMP/PKG pathway, nor affect proliferation or apoptosis in normal colonocytes. Knockdown of the cGMP-specific PDE5 isozyme by siRNA and PDE5-specific inhibitors tadalafil and sildenafil also selectively inhibited the growth of colon tumor cells that expressed high levels of PDE5 compared with colonocytes. The mechanism by which sulindac sulfide and the cGMP/PKG pathway inhibits colon tumor cell growth involves the transcriptional suppression of β-catenin to inhibit Wnt/β-catenin T-cell factor transcriptional activity, leading to downregulation of cyclin D1 and survivin. These observations suggest that safer and more efficacious sulindac derivatives can be developed for colorectal cancer chemoprevention by targeting PDE5 and possibly other cGMP-degrading isozymes. PMID:23804703

  5. Sulindac selectively inhibits colon tumor cell growth by activating the cGMP/PKG pathway to suppress Wnt/β-catenin signaling

    PubMed Central

    Li, Nan; Xi, Yaguang; Tinsley, Heather N.; Gurpinar, Evrim; Gary, Bernard D.; Zhu, Bing; Li, Yonghe; Chen, Xi; Keeton, Adam B.; Abadi, Ashraf H.; Moyer, Mary P.; Grizzle, William E.; Chang, Wen-chi; Clapper, Margie L.; Piazza, Gary A.

    2013-01-01

    NSAIDs display promising antineoplastic activity for colorectal and other cancers, but toxicity from cyclooxygenase (COX) inhibition limits their long-term use for chemoprevention. Previous studies have concluded that the basis for their tumor cell growth inhibitory activity does not required COX inhibition, although the underlying mechanism is poorly understood. Here we report that the NSAID, sulindac sulfide (SS) inhibits cyclic guanosine monophosphate phosphodiesterase (cGMP PDE) activity to increase intracellular cGMP levels and activate cGMP dependent protein kinase (PKG) at concentrations that inhibit proliferation and induce apoptosis of colon tumor cells. SS did not activate the cGMP/PKG pathway, nor affect proliferation or apoptosis in normal colonocytes. Knockdown of the cGMP-specific PDE5 isozyme by siRNA and PDE5-specific inhibitors, tadalafil and sildenafil, also selectively inhibited the growth of colon tumor cells that expressed high levels of PDE5 compared with colonocytes. The mechanism by which SS and the cGMP/PKG pathway inhibits colon tumor cell growth appears to involve the transcriptional suppression of β-catenin to inhibit Wnt/β-catenin TCF transcriptional activity, leading to down-regulation of cyclin D1 and survivin. These observations suggest that safer and more efficacious sulindac derivatives can be developed for colorectal cancer chemoprevention by targeting PDE5 and possibly other cGMP degrading isozymes. PMID:23804703

  6. Tubeimoside-1 suppresses tumor angiogenesis by stimulation of proteasomal VEGFR2 and Tie2 degradation in a non-small cell lung cancer xenograft model

    PubMed Central

    Gu, Yuan; Körbel, Christina; Scheuer, Claudia; Nenicu, Anca; Menger, Michael D.; Laschke, Matthias W.

    2016-01-01

    Tubeimoside-1 (TBMS1) is a potent anti-tumor phytochemical. Its functional and molecular mode of action, however, remains elusive so far. Since angiogenesis is essential for tumor progression and metastasis, we herein investigated the anti-angiogenic effects of the compound. In a non-small cell lung cancer (NSCLC) xenograft model we found that treatment of CD1 nu/nu mice with TBMS1 (5mg/kg) significantly suppressed the growth and vascularization of NCI-H460 flank tumors. Moreover, TBMS1 dose-dependently reduced vascular sprouting in a rat aortic ring assay. In vitro, TBMS1 induced endothelial cell apoptosis without decreasing the viability of NSCLC tumor cells and inhibited the migration of endothelial cells by disturbing their actin filament organization. TBMS1 further stimulated the proteasomal degradation of vascular endothelial growth factor receptor-2 (VEGFR2) and Tie2 in endothelial cells, which down-regulated AKT/mTOR signaling. These findings indicate that TBMS1 represents a novel phytochemical for anti-angiogenic treatment of cancer and other angiogenesis-related diseases. PMID:26701724

  7. miR-502 inhibits cell proliferation and tumor growth in hepatocellular carcinoma through suppressing phosphoinositide 3-kinase catalytic subunit gamma

    SciTech Connect

    Chen, Suling; Li, Fang; Chai, Haiyun; Tao, Xin; Wang, Haili; Ji, Aifang

    2015-08-21

    MicroRNAs (miRNAs) play a key role in carcinogenesis and tumor progression in hepatocellular carcinoma (HCC). In the present study, we demonstrated that miR-502 significantly inhibits HCC cell proliferation in vitro and tumor growth in vivo. G1/S cell cycle arrest and apoptosis of HCC cells were induced by miR-502. Phosphoinositide 3-kinase catalytic subunit gamma (PIK3CG) was identified as a direct downstream target of miR-502 in HCC cells. Notably, overexpression of PIK3CG reversed the inhibitory effects of miR-502 in HCC cells. Our findings suggest that miR-502 functions as a tumor suppressor in HCC via inhibition of PI3KCG, supporting its utility as a promising therapeutic gene target for this tumor type. - Highlights: • miR-502 suppresses HCC cell proliferation in vitro and tumorigenicity in vivo. • miR-502 regulates cell cycle and apoptosis in HCC cells. • PIK3CG is a direct target of miR-502. • miR-502 and PIK3CG expression patterns are inversely correlated in HCC tissues.

  8. CO2 bubbling-based 'Nanobomb' System for Targetedly Suppressing Panc-1 Pancreatic Tumor via Low Intensity Ultrasound-activated Inertial Cavitation

    PubMed Central

    Zhang, Kun; Xu, Huixiong; Chen, Hangrong; Jia, Xiaoqing; Zheng, Shuguang; Cai, Xiaojun; Wang, Ronghui; Mou, Juan; Zheng, Yuanyi; Shi, Jianlin

    2015-01-01

    Noninvasive and targeted physical treatment is still desirable especially for those cancerous patients. Herein, we develop a new physical treatment protocol by employing CO2 bubbling-based 'nanobomb' system consisting of low-intensity ultrasound (1.0 W/cm2) and a well-constructed pH/temperature dual-responsive CO2 release system. Depending on the temperature elevation caused by exogenous low-intensity therapeutic ultrasound irradiation and the low pH caused by the endogenous acidic-environment around/within tumor, dual-responsive CO2 release system can quickly release CO2 bubbles, and afterwards, the generated CO2 bubbles waves will timely explode before dissolution due to triggering by therapeutic ultrasound waves. Related bio-effects (e.g., cavitation, mechanical, shock waves, etc) caused by CO2 bubbles' explosion effectively induce instant necrosis of panc-1 cells and blood vessel destruction within panc-1 tumor, and consequently inhibit the growth of panc-1 solid tumor, simultaneously minimizing the side effects to normal organs. This new physiotherapy employing CO2 bubbling-based 'nanobomb' system promises significant potentials in targetedly suppressing tumors, especially for those highly deadly cancers. PMID:26379793

  9. Suppressive effects of a proton beam on tumor growth and lung metastasis through the inhibition of metastatic gene expression in 4T1 orthotopic breast cancer model.

    PubMed

    Kwon, Yun-Suk; Lee, Kyu-Shik; Chun, So-Young; Jang, Tae Jung; Nam, Kyung-Soo

    2016-07-01

    A proton beam is a next generation tool to treat intractable cancer. Although the therapeutic effects of a proton beam are well known, the effect on tumor metastasis is not fully described. Here, we investigated the effects of a proton beam on metastasis in highly invasive 4T1 murine breast cancer cells and their orthotopic breast cancer model. Cells were irradiated with 2, 4, 8 or 16 Gy proton beam, and changes in cell proliferation, survival, and migration were observed by MTT, colony forming and wound healing assays. 4T1 breast cancer cell-implanted BALB/c mice were established and the animals were randomly divided into 4 groups when tumor size reached 200 mm3. Breast tumors were selectively irradiated with 10, 20 or 30 Gy proton beam. Breast tumor sizes were measured twice a week, and breast tumor and lung tissues were pathologically observed. Metastasis-regulating gene expression was assessed with quantitative RT-PCR. A proton beam dose-dependently decreased cell proliferation, survival and migration in 4T1 murine breast cancer cells. Also, growth of breast tumors in the 4T1 orthotopic breast cancer model was significantly suppressed by proton beam irradiation without significant change of body weight. Furthermore, fewer tumor nodules metastasized from breast tumor into lung in mice irradiated with 30 Gy proton beam, but not with 10 and 20 Gy, than in control. We observed correspondingly lower expression levels of urokinase plasminogen activator (uPA), uPA receptor, cyclooxygenase (COX)-2, and vascular endothelial growth factor (VEGF), which are important factors in cancer metastasis, in breast tumor irradiated with 30 Gy proton beam. Proton beam irradiation did not affect expressions of matrix metalloproteinase (MMP)-9 and MMP-2. Taken together, the data suggest that, although proton beam therapy is an effective tool for breast cancer treatment, a suitable dose is necessary to prevent metastasis-linked relapse and poor prognosis. PMID:27176787

  10. EGCG, a major green tea catechin suppresses breast tumor angiogenesis and growth via inhibiting the activation of HIF-1α and NFκB, and VEGF expression.

    PubMed

    Gu, Jian-Wei; Makey, Kristina L; Tucker, Kevan B; Chinchar, Edmund; Mao, Xiaowen; Pei, Ivy; Thomas, Emily Y; Miele, Lucio

    2013-01-01

    The role of EGCG, a major green tea catechin in breast cancer therapy is poorly understood. The present study tests the hypothesis that EGCG can inhibit the activation of HIF-1α and NFκB, and VEGF expression, thereby suppressing tumor angiogenesis and breast cancer progression. Sixteen eight-wk-old female mice (C57BL/6 J) were inoculated with 10^6 E0771 (mouse breast cancer) cells in the left fourth mammary gland fat pad. Eight mice received EGCG at 50-100 mg/kg/d in drinking water for 4 weeks. 8 control mice received drinking water only. Tumor size was monitored using dial calipers. At the end of the experiment, blood samples, tumors, heart and limb muscles were collected for measuring VEGF expression using ELISA and capillary density (CD) using CD31 immunohistochemistry. EGCG treatment significantly reduced tumor weight over the control (0.37 ± 0.15 vs. 1.16 ± 0.30 g; P < 0.01), tumor CD (109 ± 20 vs. 156 ± 12 capillary #/mm^2; P < 0.01), tumor VEGF expression (45.72 ± 1.4 vs. 59.03 ± 3.8 pg/mg; P < 0.01), respectively. But, it has no effects on the body weight, heart weight, angiogenesis and VEGF expression in the heart and skeletal muscle of mice. EGCG at 50 μg/ml significantly inhibited the activation of HIF-1α and NFκB as well as VEGF expression in cultured E0771 cells, compared to the control, respectively. These findings support the hypothesis that EGCG, a major green tea catechin, directly targets both tumor cells and tumor vasculature, thereby inhibiting tumor growth, proliferation, migration, and angiogenesis of breast cancer, which is mediated by the inhibition of HIF-1α and NFκB activation as well as VEGF expression.

  11. EGCG, a major green tea catechin suppresses breast tumor angiogenesis and growth via inhibiting the activation of HIF-1α and NFκB, and VEGF expression

    PubMed Central

    2013-01-01

    The role of EGCG, a major green tea catechin in breast cancer therapy is poorly understood. The present study tests the hypothesis that EGCG can inhibit the activation of HIF-1α and NFκB, and VEGF expression, thereby suppressing tumor angiogenesis and breast cancer progression. Sixteen eight-wk-old female mice (C57BL/6 J) were inoculated with 10^6 E0771 (mouse breast cancer) cells in the left fourth mammary gland fat pad. Eight mice received EGCG at 50–100 mg/kg/d in drinking water for 4 weeks. 8 control mice received drinking water only. Tumor size was monitored using dial calipers. At the end of the experiment, blood samples, tumors, heart and limb muscles were collected for measuring VEGF expression using ELISA and capillary density (CD) using CD31 immunohistochemistry. EGCG treatment significantly reduced tumor weight over the control (0.37 ± 0.15 vs. 1.16 ± 0.30 g; P < 0.01), tumor CD (109 ± 20 vs. 156 ± 12 capillary #/mm^2; P < 0.01), tumor VEGF expression (45.72 ± 1.4 vs. 59.03 ± 3.8 pg/mg; P < 0.01), respectively. But, it has no effects on the body weight, heart weight, angiogenesis and VEGF expression in the heart and skeletal muscle of mice. EGCG at 50 μg/ml significantly inhibited the activation of HIF-1α and NFκB as well as VEGF expression in cultured E0771 cells, compared to the control, respectively. These findings support the hypothesis that EGCG, a major green tea catechin, directly targets both tumor cells and tumor vasculature, thereby inhibiting tumor growth, proliferation, migration, and angiogenesis of breast cancer, which is mediated by the inhibition of HIF-1α and NFκB activation as well as VEGF expression. PMID:23638734

  12. EGFR-targeted plasmonic magnetic nanoparticles suppress lung tumor growth by abrogating G2/M cell-cycle arrest and inducing DNA damage

    PubMed Central

    Kuroda, Shinji; Tam, Justina; Roth, Jack A; Sokolov, Konstantin; Ramesh, Rajagopal

    2014-01-01

    Background We have previously demonstrated the epidermal growth factor receptor (EGFR)-targeted hybrid plasmonic magnetic nanoparticles (225-NP) produce a therapeutic effect in human lung cancer cell lines in vitro. In the present study, we investigated the molecular mechanism of 225-NP-mediated antitumor activity both in vitro and in vivo using the EGFR-mutant HCC827 cell line. Methods The growth inhibitory effect of 225-NP on lung tumor cells was determined by cell viability and cell-cycle analysis. Protein expression related to autophagy, apoptosis, and DNA-damage were determined by Western blotting and immunofluorescence. An in vivo efficacy study was conducted using a human lung tumor xenograft mouse model. Results The 225-NP treatment markedly reduced tumor cell viability at 72 hours compared with the cell viability in control treatment groups. Cell-cycle analysis showed the percentage of cells in the G2/M phase was reduced when treated with 225-NP, with a concomitant increase in the number of cells in Sub-G1 phase, indicative of cell death. Western blotting showed LC3B and PARP cleavage, indicating 225-NP-treatment activated both autophagy- and apoptosis-mediated cell death. The 225-NP strongly induced γH2AX and phosphorylated histone H3, markers indicative of DNA damage and mitosis, respectively. Additionally, significant γH2AX foci formation was observed in 225-NP-treated cells compared with control treatment groups, suggesting 225-NP induced cell death by triggering DNA damage. The 225-NP-mediated DNA damage involved abrogation of the G2/M checkpoint by inhibiting BRCA1, Chk1, and phospho-Cdc2/CDK1 protein expression. In vivo therapy studies showed 225-NP treatment reduced EGFR phosphorylation, increased γH2AX foci, and induced tumor cell apoptosis, resulting in suppression of tumor growth. Conclusion The 225-NP treatment induces DNA damage and abrogates G2/M phase of the cell cycle, leading to cellular apoptosis and suppression of lung tumor growth

  13. Tumor-suppressive function of long noncoding RNA MALAT1 in glioma cells by downregulation of MMP2 and inactivation of ERK/MAPK signaling.

    PubMed

    Han, Y; Wu, Z; Wu, T; Huang, Y; Cheng, Z; Li, X; Sun, T; Xie, X; Zhou, Y; Du, Z

    2016-03-03

    Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a type of long noncoding RNA. It is associated with metastasis and is a favorable prognostic factor for lung cancer. Recent studies have shown that MALAT1 plays an important role in other malignancies. But, little is known about the role of MALAT1 in glioma. In this study, quantitative reverse transcription PCR (qRT-PCR) was used to demonstrate that the expression of MALAT1 was lower than that in normal brain tissues. Stable RNA interference-mediated knockdown of MALAT1 in human glioma cell lines (U87 and U251) significantly promoted the invasion and proliferation of the glioma cells by in vitro assays. Conversely, overexpression of MALAT1 caused significant reduction in cell proliferation and invasion in vitro, and tumorigenicity in both subcutaneous and intracranial human glioma xenograft models. Furthermore, MALAT1-mediated tumor suppression in glioma cells may be via reduction of extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK) signaling activity and expression of matrix metalloproteinase 2 (MMP2). In conclusion, overall data demonstrated the tumor-suppressive role of MALAT1 in glioma by attenuating ERK/MAPK-mediated growth and MMP2-mediated invasiveness.

  14. Tumor-suppressive function of long noncoding RNA MALAT1 in glioma cells by downregulation of MMP2 and inactivation of ERK/MAPK signaling

    PubMed Central

    Han, Y; Wu, Z; Wu, T; Huang, Y; Cheng, Z; Li, X; Sun, T; Xie, X; Zhou, Y; Du, Z

    2016-01-01

    Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a type of long noncoding RNA. It is associated with metastasis and is a favorable prognostic factor for lung cancer. Recent studies have shown that MALAT1 plays an important role in other malignancies. But, little is known about the role of MALAT1 in glioma. In this study, quantitative reverse transcription PCR (qRT-PCR) was used to demonstrate that the expression of MALAT1 was lower than that in normal brain tissues. Stable RNA interference-mediated knockdown of MALAT1 in human glioma cell lines (U87 and U251) significantly promoted the invasion and proliferation of the glioma cells by in vitro assays. Conversely, overexpression of MALAT1 caused significant reduction in cell proliferation and invasion in vitro, and tumorigenicity in both subcutaneous and intracranial human glioma xenograft models. Furthermore, MALAT1-mediated tumor suppression in glioma cells may be via reduction of extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK) signaling activity and expression of matrix metalloproteinase 2 (MMP2). In conclusion, overall data demonstrated the tumor-suppressive role of MALAT1 in glioma by attenuating ERK/MAPK-mediated growth and MMP2-mediated invasiveness. PMID:26938295

  15. Suppression of tumor growth in lung cancer xenograft model mice by poly(sorbitol-co-PEI)-mediated delivery of osteopontin siRNA.

    PubMed

    Cho, Won-Young; Hong, Seong-Ho; Singh, Bijay; Islam, Mohammad Ariful; Lee, Somin; Lee, Ah Young; Gankhuyag, Nomundelger; Kim, Ji-Eun; Yu, Kyeong-Nam; Kim, Kwang-Ho; Park, Young-Chan; Cho, Chong-Su; Cho, Myung-Haing

    2015-08-01

    Small interfering RNA (siRNA)-mediated gene silencing represents a promising strategy for treating diseases such as cancer; however, specific gene silencing requires an effective delivery system to overcome the instability and low transfection efficiency of siRNAs. To address this issue, a polysorbitol-based transporter (PSOT) was prepared by low molecular weight branched polyethylenimine (bPEI) crosslinked with sorbitol diacrylate (SDA). Osteopontin (OPN) gene, which is highly associated with non-small cell lung cancer (NSCLC) was targeted by siRNA therapy using siRNA targeting OPN (siOPN). Characterization study confirmed that PSOT formed compact complexes with siOPN and protected siOPN against degradation by RNase. PSOT/siOPN complexes demonstrated low cytotoxicity and enhanced transfection efficiency in vitro, suggesting that this carrier may be suitable for gene silencing. In the A549 and H460 lung cancer cell lines, PSOT/siOPN complexes demonstrated significant silencing efficiency at both RNA and protein levels. To study in vivo tumor growth suppression, two lung cancer cell-xenograft mouse models were prepared and PSOT/siOPN complexes were delivered into the mice through intravenous injection. The siOPN-treated groups demonstrated significantly reduced OPN expression at both the RNA and protein levels as well as suppression of tumor volume and weight. Taken together, siOPN delivery using PSOT may present an effective and novel therapeutic system for lung cancer treatment.

  16. Tamoxifen inhibits tumor cell invasion and metastasis in mouse melanoma through suppression of PKC/MEK/ERK and PKC/PI3K/Akt pathways

    SciTech Connect

    Matsuoka, Hiroshi; Tsubaki, Masanobu; Yamazoe, Yuzuru; Ogaki, Mitsuhiko; Satou, Takao; Itoh, Tatsuki; Kusunoki, Takashi; Nishida, Shozo

    2009-07-15

    In melanoma, several signaling pathways are constitutively activated. Among these, the protein kinase C (PKC) signaling pathways are activated through multiple signal transduction molecules and appear to play major roles in melanoma progression. Recently, it has been reported that tamoxifen, an anti-estrogen reagent, inhibits PKC signaling in estrogen-negative and estrogen-independent cancer cell lines. Thus, we investigated whether tamoxifen inhibited tumor cell invasion and metastasis in mouse melanoma cell line B16BL6. Tamoxifen significantly inhibited lung metastasis, cell migration, and invasion at concentrations that did not show anti-proliferative effects on B16BL6 cells. Tamoxifen also inhibited the mRNA expressions and protein activities of matrix metalloproteinases (MMPs). Furthermore, tamoxifen suppressed phosphorylated extracellular signal-regulated kinase 1/2 (ERK1/2) and Akt through the inhibition of PKC{alpha} and PKC{delta} phosphorylation. However, other signal transduction factor, such as p38 mitogen-activated protein kinase (p38MAPK) was unaffected. The results indicate that tamoxifen suppresses the PKC/mitogen-activated protein kinase kinase (MEK)/ERK and PKC/phosphatidylinositol-3 kinase (PI3K)/Akt pathways, thereby inhibiting B16BL6 cell migration, invasion, and metastasis. Moreover, tamoxifen markedly inhibited not only developing but also clinically evident metastasis. These findings suggest that tamoxifen has potential clinical applications for the treatment of tumor cell metastasis.

  17. DEC2 suppresses tumor proliferation and metastasis by regulating ERK/NF-κB pathway in gastric cancer.

    PubMed

    Li, Ping; Jia, Yan-Fei; Ma, Xiao-Li; Zheng, Yan; Kong, Yi; Zhang, Yao; Zong, Shuai; Chen, Zhi-Tao; Wang, Yun-Shan

    2016-01-01

    Differentiated embryonic chondrocyte expressed gene 2 (DEC2; BHLHE41/Sharp1) is a helix-loop-helix (bHLH) transcription factor, and its deregulation has been observed in several tumors. However, this gene's effects on tumor progression are controversial, and its roles in gastric cancer (GC) remain unclear. In the present study, we found that DEC2 expression level is lower in GC tissues compared with adjacent non-tumor tissues, and negatively correlated with tumor invasion, lymph node metastasis, TNM stage, and poor survival of GC patients. Positive clinical correlations of DEC2 with EMT regulator, E-cadherin, were also observed in the tissue sections. Overexpression of DEC2 inhibits cell proliferation and EMT in vitro, as well as tumor growth and metastasis in vivo. DEC2 expression also induces cell apoptosis. Furthermore, the anti-metastatic effect of DEC2 was mediated by inhibiting ERK/NF-κB/EMT axis. After treatment with ERK1/2 chemical inhibitor (U0126), DEC2's inhibitory effect on ERK/NF-κB/EMT was further decreased. Collectively, these data helped to characterize DEC2, which might be a potential molecular target for diagnostic and therapeutic approaches for GC. PMID:27648362

  18. Lowered Expression of Tumor Suppressor Candidate MYO1C Stimulates Cell Proliferation, Suppresses Cell Adhesion and Activates AKT

    PubMed Central

    Visuttijai, Kittichate; Pettersson, Jennifer; Mehrbani Azar, Yashar; van den Bout, Iman; Örndal, Charlotte; Marcickiewicz, Janusz; Nilsson, Staffan; Hörnquist, Michael; Olsson, Björn; Ejeskär, Katarina

    2016-01-01

    Myosin-1C (MYO1C) is a tumor suppressor candidate located in a region of recurrent losses distal to TP53. Myo1c can tightly and specifically bind to PIP2, the substrate of Phosphoinositide 3-kinase (PI3K), and to Rictor, suggesting a role for MYO1C in the PI3K pathway. This study was designed to examine MYO1C expression status in a panel of well-stratified endometrial carcinomas as well as to assess the biological significance of MYO1C as a tumor suppressor in vitro. We found a significant correlation between the tumor stage and lowered expression of MYO1C in endometrial carcinoma samples. In cell transfection experiments, we found a negative correlation between MYO1C expression and cell proliferation, and MYO1C silencing resulted in diminished cell migration and adhesion. Cells expressing excess of MYO1C had low basal level of phosphorylated protein kinase B (PKB, a.k.a. AKT) and cells with knocked down MYO1C expression showed a quicker phosphorylated AKT (pAKT) response in reaction to serum stimulation. Taken together the present study gives further evidence for tumor suppressor activity of MYO1C and suggests MYO1C mediates its tumor suppressor function through inhibition of PI3K pathway and its involvement in loss of contact inhibition. PMID:27716847

  19. DEC2 suppresses tumor proliferation and metastasis by regulating ERK/NF-κB pathway in gastric cancer

    PubMed Central

    Li, Ping; Jia, Yan-Fei; Ma, Xiao-Li; Zheng, Yan; Kong, Yi; Zhang, Yao; Zong, Shuai; Chen, Zhi-Tao; Wang, Yun-Shan

    2016-01-01

    Differentiated embryonic chondrocyte expressed gene 2 (DEC2; BHLHE41/Sharp1) is a helix-loop-helix (bHLH) transcription factor, and its deregulation has been observed in several tumors. However, this gene’s effects on tumor progression are controversial, and its roles in gastric cancer (GC) remain unclear. In the present study, we found that DEC2 expression level is lower in GC tissues compared with adjacent non-tumor tissues, and negatively correlated with tumor invasion, lymph node metastasis, TNM stage, and poor survival of GC patients. Positive clinical correlations of DEC2 with EMT regulator, E-cadherin, were also observed in the tissue sections. Overexpression of DEC2 inhibits cell proliferation and EMT in vitro, as well as tumor growth and metastasis in vivo. DEC2 expression also induces cell apoptosis. Furthermore, the anti-metastatic effect of DEC2 was mediated by inhibiting ERK/NF-κB/EMT axis. After treatment with ERK1/2 chemical inhibitor (U0126), DEC2’s inhibitory effect on ERK/NF-κB/EMT was further decreased. Collectively, these data helped to characterize DEC2, which might be a potential molecular target for diagnostic and therapeutic approaches for GC. PMID:27648362

  20. DEC2 suppresses tumor proliferation and metastasis by regulating ERK/NF-κB pathway in gastric cancer

    PubMed Central

    Li, Ping; Jia, Yan-Fei; Ma, Xiao-Li; Zheng, Yan; Kong, Yi; Zhang, Yao; Zong, Shuai; Chen, Zhi-Tao; Wang, Yun-Shan

    2016-01-01

    Differentiated embryonic chondrocyte expressed gene 2 (DEC2; BHLHE41/Sharp1) is a helix-loop-helix (bHLH) transcription factor, and its deregulation has been observed in several tumors. However, this gene’s effects on tumor progression are controversial, and its roles in gastric cancer (GC) remain unclear. In the present study, we found that DEC2 expression level is lower in GC tissues compared with adjacent non-tumor tissues, and negatively correlated with tumor invasion, lymph node metastasis, TNM stage, and poor survival of GC patients. Positive clinical correlations of DEC2 with EMT regulator, E-cadherin, were also observed in the tissue sections. Overexpression of DEC2 inhibits cell proliferation and EMT in vitro, as well as tumor growth and metastasis in vivo. DEC2 expression also induces cell apoptosis. Furthermore, the anti-metastatic effect of DEC2 was mediated by inhibiting ERK/NF-κB/EMT axis. After treatment with ERK1/2 chemical inhibitor (U0126), DEC2’s inhibitory effect on ERK/NF-κB/EMT was further decreased. Collectively, these data helped to characterize DEC2, which might be a potential molecular target for diagnostic and therapeutic approaches for GC.

  1. CD4+CD25+FOXP3+ Regulatory T Cells Suppress Anti-Tumor Immune Responses in Patients with Colorectal Cancer

    PubMed Central

    Plant, Andrea; Wright, Kate L.; El-Shanawany, Tariq M.; Harrop, Richard; Torkington, Jared; Rees, Brian I.; Williams, Geraint T.

    2006-01-01

    Background A wealth of evidence obtained using mouse models indicates that CD4+CD25+FOXP3+ regulatory T cells (Treg) maintain peripheral tolerance to self-antigens and also inhibit anti-tumor immune responses. To date there is limited information about CD4+ T cell responses in patients with colorectal cancer (CRC). We set out to measure T cell responses to a tumor-associated antigen and examine whether Treg impinge on those anti-tumor immune responses in CRC patients. Methodology and Principal Findings Treg were identified and characterized as CD4+CD25+FOXP3+ using flow cytometry. An increased frequency of Treg was demonstrated in both peripheral blood and mesenteric lymph nodes of patients with colorectal cancer (CRC) compared with either healthy controls or patients with inflammatory bowel disease (IBD). Depletion of Treg from peripheral blood mononuclear cells (PBMC) of CRC patients unmasked CD4+ T cell responses, as observed by IFNγ release, to the tumor associated antigen 5T4, whereas no effect was observed in a healthy age-matched control group. Conclusions/Significance Collectively, these data demonstrate that Treg capable of inhibiting tumor associated antigen-specific immune responses are enriched in patients with CRC. These results support a rationale for manipulating Treg to enhance cancer immunotherapy. PMID:17205133

  2. miRs-134 and -370 function as tumor suppressors in colorectal cancer by independently suppressing EGFR and PI3K signalling

    PubMed Central

    El-Daly, Sherien M.; Abba, Mohammed L.; Patil, Nitin; Allgayer, Heike

    2016-01-01

    Growth factor receptor signalling plays a central and critical role in colorectal cancer. Most importantly, the EGFR signalling cascade involving PI3K/AKT/mTOR and Raf/MEK/ERK pathways are particularly relevant, since they are commonly activated in several cancer entities, including colorectal cancer. In this study, we show that miRs-134 and -370 are both capable of regulating these pathways by targeting EGFR and PIK3CA. In three different colorectal cancer cell lines (DLD1, HCT-116 and RKO), suppression of EGFR and PIK3CA through the enhanced expression of miR-134 or -370 led to a suppression of the key molecules of the PI3K/AKT/mTOR pathway. Furthermore, overexpression of miR-134 or -370 resulted in a significant reduction of cell proliferation, colony formation, migration, invasion and in-vivo tumor growth and metastasis. Concurrent experiments with small interfering RNAs targeting the prime targets show that our selected miRNAs exert a greater functional influence and affect more downstream molecules than is seen with silencing of the individual proteins. Taken together, these data indicate that miRs-134 and -370 are potential tumour suppressor miRNAs and could play a fundamental role in suppressing colorectal cancer tumorigenesis through their ability to co-ordinately regulate EGFR signalling cascade by independently targeting EGFR and PIK3CA. PMID:27095166

  3. Tumor growth suppressive effect of IL-4 through p21-mediated activation of STAT6 in IL-4Rα overexpressed melanoma models

    PubMed Central

    Song, Ju Kyoung; Jung, Yu Yeon; Kim, Youngsoo; Kim, Kyung Bo; Hwang, Dae Yeon; Yoon, Do Young; Song, Min Jong; Han, Sang Bae; Hong, Jin Tae

    2016-01-01

    To evaluate the significance of interleukin 4 (IL-4) in tumor development, we compared B16F10 melanoma growth in IL-4-overespressing transgenic mice (IL-4 mice) and non-transgenic mice. In IL-4 mice, reduced tumor volume and weight were observed when compared with those of non-transgenic mice. Significant activation of DNA binding activity of STAT6, phosphorylation of STAT6 as well as IL-4, IL-4Rα and p21 expression were found in the tumor tissues of IL-4 mice compared to non-transgenic mice. Higher expression of IL-4, STAT6 and p21 in human melanoma tissue compared to normal human skin tissue was also found. Higher expression of apoptotic protein such as cleaved caspase-3, cleaved caspase-8, cleaved caspase-9, Bax, p53 and p21, but lower expression levels of survival protein such as Bcl-2 were found in the tumor of IL-4 mice. In vitro study, we found that overexpression of IL-4 significantly inhibited SK-MEL-28 human melanoma cell and B16F10 murine melanoma cell growth via p21-mediated activation of STAT6 pathway as well as increased expression of apoptotic cell death proteins. Moreover, p21 knockdown with siRNA abolished IL-4 induced activation of STAT6 and expression of p53 and p21 accompanied with reduced IL-4 expression as well as melanoma cell growth inhibition. Therefore, these results showed that IL-4 overexpression suppressed tumor development through p21-mediated activation of STAT6 pathways in melanoma models. PMID:26993600

  4. Delivery of Therapeutics Targeting the mRNA-Binding Protein HuR Using 3DNA Nanocarriers Suppresses Ovarian Tumor Growth.

    PubMed

    Huang, Yu-Hung; Peng, Weidan; Furuuchi, Narumi; Gerhart, Jacquelyn; Rhodes, Kelly; Mukherjee, Neelanjan; Jimbo, Masaya; Gonye, Gregory E; Brody, Jonathan R; Getts, Robert C; Sawicki, Janet A

    2016-03-15

    Growing evidence shows that cancer cells use mRNA-binding proteins and miRNAs to posttranscriptionally regulate signaling pathways to adapt to harsh tumor microenvironments. In ovarian cancer, cytoplasmic accumulation of mRNA-binding protein HuR (ELAVL1) is associated with poor prognosis. In this study, we observed high HuR expression in ovarian cancer cells compared with ovarian primary cells, providing a rationale for targeting HuR. RNAi-mediated silencing of HuR in ovarian cancer cells significantly decreased cell proliferation and anchorage-independent growth, and impaired migration and invasion. In addition, HuR-depleted human ovarian xenografts were smaller than control tumors. A biodistribution study showed effective tumor-targeting by a novel Cy3-labeled folic acid (FA)-derivatized DNA dendrimer nanocarrier (3DNA). We combined siRNAs against HuR with FA-3DNA and found that systemic administration of the resultant FA-3DNA-siHuR conjugates to ovarian tumor-bearing mice suppressed tumor growth and ascites development, significantly prolonging lifespan. NanoString gene expression analysis identified multiple HuR-regulated genes that function in many essential cellular and molecular pathways, an attractive feature of candidate therapeutic targets. Taken together, these results are the first to demonstrate the versatility of the 3DNA nanocarrier for in vivo-targeted delivery of a cancer therapeutic and support further preclinical investigation of this system adapted to siHuR-targeted therapy for ovarian cancer.

  5. Krüppel-Like Factor 4, a Tumor Suppressor in Hepatocellular Carcinoma Cells Reverts Epithelial Mesenchymal Transition by Suppressing Slug Expression

    PubMed Central

    Yen, Yi-Chen; Lewis, Brian C.; Chen, Ya-Wen

    2012-01-01

    Krüppel-like factor 4 (KLF4) is a zinc-finger transcription factor that plays an important role in differentiation and pathogenesis. KLF4 has been suggested to act as an oncogene or tumor suppressor in different tumor types. However, the role of KLF4 in hepatocellular carcinoma (HCC) remains unclear. Here, we demonstrate that forced expression of Klf4 in murine HCC cell lines reduced anchorage-independent growth in soft agar as well as cell migration and invasion activities in vitro. Ectopic Klf4 expression impaired subcutaneous tumor growth and lung colonization in vivo. By contrast, Klf4 knockdown enhanced HCC cell migration. Interestingly, ectopic expression of Klf4 changed the morphology of murine HCC cells to a more epithelial phenotype. Associated with this, we found that expression of Slug, a critical epithelial mesenchymal transition (EMT)-related transcription factor, was significantly down-regulated in Klf4-expressing cells. Chromatin immunoprecipitation (ChIP) and luciferase reporter assays showed that Klf4 is able to bind and repress the activity of the Slug promoter. Furthermore, ectopic Slug expression partially reverts the Klf4-mediated phenotypes. Consistent with a role as a tumor suppressor in HCC, analysis of the public microarray databases from Oncomine revealed reduced KLF4 expression in human HCC tissues in comparison with normal liver tissues in 3 out of 4 data sets. By quantitative reverse transcription-polymerase chain reaction (qRT-PCR), we found reduced KLF4 mRNA in 50% of HCC tissues. Importantly, an inverse correlation between the expression of KLF4 and SLUG was found in HCC tissues. Our data suggest that KLF4 acts as a tumor suppressor in HCC cells, in part by suppressing SLUG transcription. PMID:22937066

  6. Tumor suppressive microRNA-218 inhibits cancer cell migration and invasion through targeting laminin-332 in head and neck squamous cell carcinoma.

    PubMed

    Kinoshita, Takashi; Hanazawa, Toyoyuki; Nohata, Nijiro; Kikkawa, Naoko; Enokida, Hideki; Yoshino, Hirofumi; Yamasaki, Takeshi; Hidaka, Hideo; Nakagawa, Masayuki; Okamoto, Yoshitaka; Seki, Naohiko

    2012-11-01

    Recent our microRNA (miRNA) expression signature revealed that expression of microRNA-218 (miR-218) was reduced in cancer tissues, suggesting a candidate of tumor suppressor in head and neck squamous cell carcinoma (HNSCC). The aim of this study was to investigate the functional significance of miR-218 and its mediated moleculer pathways in HNSCC. Restoration of miR-218 in cancer cells led to significant inhibition of cell migration and invasion activities in HNSCC cell lines (FaDu and SAS). Genome-wide gene expression analysis of miR-218 transfectants and in silico database analysis showed that focal adhesion pathway was a promising candidate of miR-218 target pathways. The laminins are an important and biologically active part of the basal lamina, the function of that are various such as influencing cell differentiation, migration and adhesion as well as proliferation and cell survival. Interestingly, all components of laminin-332 (LAMA3, LAMB3 and LAMC2) are listed on the candidate genes in focal adhesion pathway. Furthermore, we focused on LAMB3 which has a miR-218 target site and gene expression studies and luciferase reporter assays showed that LAMB3 was directly regulated by miR-218. Silencing study of LAMB3 demonstrated significant inhibition of cell migration and invasion. In clinical specimens with HNSCC, the expression levels of laminin-332 were significantly upregulated in cancer tissues compared to adjacent non-cancerous tissues. Our analysis data showed that tumor suppressive miR-218 contributes to cancer cell migration and invasion through regulating focal adhesion pathway, especially laminin-332. Tumor suppressive miRNA-mediated novel cancer pathways provide new insights into the potential mechanisms of HNSCC oncogenesis. PMID:23159910

  7. Boswellic Acid Suppresses Growth and Metastasis of Human Pancreatic Tumors in an Orthotopic Nude Mouse Model through Modulation of Multiple Targets

    PubMed Central

    Park, Byoungduck; Prasad, Sahdeo; Yadav, Vivek; Sung, Bokyung; Aggarwal, Bharat B.

    2011-01-01

    Pancreatic cancer (PaCa) is one of the most lethal cancers, with an estimated 5-year survival of <5% even when patients are given the best treatment available. In addition, these treatments are often toxic and expensive, thus new agents which are safe, affordable and effective are urgently needed. We describe here the results of our study with acetyl-11-keto-β-boswellic acid (AKBA), an agent obtained from an Ayurvedic medicine, gum resin of Boswellia serrata. Whether AKBA has an activity against human PaCa, was examined in in vitro models and in an orthotopic nude mouse model of PaCa. We found that AKBA inhibited the proliferation of four different PaCa cell lines (AsPC-1, PANC-28, and MIA PaCa-2 with K-Ras and p53 mutations, and BxPC-3 with wild-type K-Ras and p53 mutation). These effects correlated with an inhibition of constitutively active NF-κB and suppression of NF-κB regulating gene expression. AKBA also induced apoptosis, and sensitized the cells to apoptotic effects of gemcitabine. In the orthotopic nude mouse model of PaCa, p.o. administration of AKBA alone (100 mg/kg) significantly inhibited the tumor growth; this activity was enhanced by gemcitabine. In addition, AKBA inhibited the metastasis of the PaCa to spleen, liver, and lungs. This correlated with decreases in Ki-67, a biomarker of proliferation, and CD31, a biomarker of microvessel density, in the tumor tissue. AKBA produced significant decreases in the expression of NF-κB regulating genes in the tissues. Immunohistochemical analysis also showed AKBA downregulated the expression of COX-2, MMP-9, CXCR4, and VEGF in the tissues. Overall these results demonstrate that AKBA can suppress the growth and metastasis of human pancreatic tumors in an orthotopic nude mouse model that correlates with modulation of multiple targets. PMID:22066019

  8. Tumor-suppressive miR-218-5p inhibits cancer cell proliferation and migration via EGFR in non-small cell lung cancer

    PubMed Central

    Liao, Zhicong; Fu, Zheng; Hong, Yeting; Zhou, Yong; Zhang, Chen-Yu; Chen, Xi

    2016-01-01

    Lung cancer remains the leading cause of cancer-related death worldwide, and non-small cell lung cancer (NSCLC) accounts for approximately 80% of lung cancer cases. Recently, microRNAs (miRNAs) have been consistently demonstrated to be involved in NSCLC and to act as either tumor oncogenes or tumor suppressors. In this study, we identified a specific binding site for miR-218-5p in the 3′-untranslated region of the epidermal growth factor receptor (EGFR). We further experimentally validated miR-218-5p as a direct regulator of EGFR. We also identified an inverse correlation between miR-218-5p and EGFR protein levels in NSCLC tissue samples. Moreover, we demonstrated that miR-218-5p plays a critical role in suppressing the proliferation and migration of lung cancer cells probably by binding to EGFR. Finally, we examined the function of miR-218-5p in vivo and revealed that miR-218-5p exerts an anti-tumor effect by negatively regulating EGFR in a xenograft mouse model. Taken together, the results of this study highlight an important role for miR-218-5p in the regulation of EGFR in NSCLC and may open new avenues for future lung cancer therapies. PMID:27057632

  9. Tumor suppression in mice lacking GABARAP, an Atg8/LC3 family member implicated in autophagy, is associated with alterations in cytokine secretion and cell death

    PubMed Central

    Salah, F S; Ebbinghaus, M; Muley, V Y; Zhou, Z; Al-Saadi, K R D; Pacyna-Gengelbach, M; O'Sullivan, G A; Betz, H; König, R; Wang, Z-Q; Bräuer, R; Petersen, I

    2016-01-01

    GABARAP belongs to an evolutionary highly conserved gene family that has a fundamental role in autophagy. There is ample evidence for a crosstalk between autophagy and apoptosis as well as the immune response. However, the molecular details for these interactions are not fully characterized. Here, we report that the ablation of murine GABARAP, a member of the Atg8/LC3 family that is central to autophagosome formation, suppresses the incidence of tumor formation mediated by the carcinogen DMBA and results in an enhancement of the immune response through increased secretion of IL-1β, IL-6, IL-2 and IFN-γ from stimulated macrophages and lymphocytes. In contrast, TGF-β1 was significantly reduced in the serum of these knockout mice. Further, DMBA treatment of these GABARAP knockout mice reduced the cellularity of the spleen and the growth of mammary glands through the induction of apoptosis. Gene expression profiling of mammary glands revealed significantly elevated levels of Xaf1, an apoptotic inducer and tumor-suppressor gene, in knockout mice. Furthermore, DMBA treatment triggered the upregulation of pro-apoptotic (Bid, Apaf1, Bax), cell death (Tnfrsf10b, Ripk1) and cell cycle inhibitor (Cdkn1a, Cdkn2c) genes in the mammary glands. Finally, tumor growth of B16 melanoma cells after subcutaneous inoculation was inhibited in GABARAP-deficient mice. Together, these data provide strong evidence for the involvement of GABARAP in tumorigenesis in vivo by delaying cell death and its associated immune-related response. PMID:27124579

  10. Rhus coriaria suppresses angiogenesis, metastasis and tumor growth of breast cancer through inhibition of STAT3, NFκB and nitric oxide pathways

    PubMed Central

    El Hasasna, Hussain; Saleh, Alaaeldin; Samri, Halima Al; Athamneh, Khawlah; Attoub, Samir; Arafat, Kholoud; Benhalilou, Nehla; Alyan, Sofyan; Viallet, Jean; Dhaheri, Yusra Al; Eid, Ali; Iratni, Rabah

    2016-01-01

    Recently, we reported that Rhus coriaria exhibits anticancer activities by promoting cell cycle arrest and autophagic cell death of the metastatic triple negative MDA-MB-231 breast cancer cells. Here, we investigated the effect of Rhus coriaria on the migration, invasion, metastasis and tumor growth of TNBC cells. Our current study revealed that non-cytotoxic concentrations of Rhus coriaria significantly inhibited migration and invasion, blocked adhesion to fibronectin and downregulated MMP-9 and prostaglandin E2 (PgE2). Not only did Rhus coriaria decrease their adhesion to HUVECs and to lung microvascular endothelial (HMVEC-L) cells, but it also inhibited the transendothelial migration of MDA-MB-231 cells through TNF-α-activated HUVECs. Furthermore, we found that Rhus coriaria inhibited angiogenesis, reduced VEGF production in both MDA-MB-231 and HUVECs and downregulated the inflammatory cytokines TNF-α, IL-6 and IL-8. The underlying mechanism for Rhus coriaria effects appears to be through inhibiting NFκB, STAT3 and nitric oxide (NO) pathways. Most importantly, by using chick embryo tumor growth assay, we showed that Rhus coriaria suppressed tumor growth and metastasis in vivo. The results described in the present study identify Rhus coriaria as a promising chemopreventive and therapeutic candidate that modulate triple negative breast cancer growth and metastasis. PMID:26888313

  11. Tumor suppression in mice lacking GABARAP, an Atg8/LC3 family member implicated in autophagy, is associated with alterations in cytokine secretion and cell death.

    PubMed

    Salah, F S; Ebbinghaus, M; Muley, V Y; Zhou, Z; Al-Saadi, K R D; Pacyna-Gengelbach, M; O'Sullivan, G A; Betz, H; König, R; Wang, Z-Q; Bräuer, R; Petersen, I

    2016-01-01

    GABARAP belongs to an evolutionary highly conserved gene family that has a fundamental role in autophagy. There is ample evidence for a crosstalk between autophagy and apoptosis as well as the immune response. However, the molecular details for these interactions are not fully characterized. Here, we report that the ablation of murine GABARAP, a member of the Atg8/LC3 family that is central to autophagosome formation, suppresses the incidence of tumor formation mediated by the carcinogen DMBA and results in an enhancement of the immune response through increased secretion of IL-1β, IL-6, IL-2 and IFN-γ from stimulated macrophages and lymphocytes. In contrast, TGF-β1 was significantly reduced in the serum of these knockout mice. Further, DMBA treatment of these GABARAP knockout mice reduced the cellularity of the spleen and the growth of mammary glands through the induction of apoptosis. Gene expression profiling of mammary glands revealed significantly elevated levels of Xaf1, an apoptotic inducer and tumor-suppressor gene, in knockout mice. Furthermore, DMBA treatment triggered the upregulation of pro-apoptotic (Bid, Apaf1, Bax), cell death (Tnfrsf10b, Ripk1) and cell cycle inhibitor (Cdkn1a, Cdkn2c) genes in the mammary glands. Finally, tumor growth of B16 melanoma cells after subcutaneous inoculation was inhibited in GABARAP-deficient mice. Together, these data provide strong evidence for the involvement of GABARAP in tumorigenesis in vivo by delaying cell death and its associated immune-related response. PMID:27124579

  12. Suppression of Rev3, the catalytic subunit of Pol{zeta}, sensitizes drug-resistant lung tumors to chemotherapy.

    PubMed

    Doles, Jason; Oliver, Trudy G; Cameron, Eleanor R; Hsu, Gerald; Jacks, Tyler; Walker, Graham C; Hemann, Michael T

    2010-11-30

    Platinum-based chemotherapeutic drugs are front-line therapies for the treatment of non-small cell lung cancer. However, intrinsic drug resistance limits the clinical efficacy of these agents. Recent evidence suggests that loss of the translesion polymerase, Polζ, can sensitize tumor cell lines to cisplatin, although the relevance of these findings to the treatment of chemoresistant tumors in vivo has remained unclear. Here, we describe a tumor transplantation approach that enables the rapid introduction of defined genetic lesions into a preclinical model of lung adenocarcinoma. Using this approach, we examined the effect of impaired translesion DNA synthesis on cisplatin response in aggressive late-stage lung cancers. In the presence of reduced levels of Rev3, an essential component of Polζ, tumors exhibited pronounced sensitivity to cisplatin, leading to a significant extension in overall survival of treated recipient mice. Additionally, treated Rev3-deficient cells exhibited reduced cisplatin-induced mutation, a process that has been implicated in the induction of secondary malignancies following chemotherapy. Taken together, our data illustrate the potential of Rev3 inhibition as an adjuvant therapy for the treatment of chemoresistant malignancies, and highlight the utility of rapid transplantation methodologies for evaluating mechanisms of chemotherapeutic resistance in preclinical settings.

  13. Tumor progression locus 2 ablation suppressed hepatocellular carcinoma development by inhibiting hepatic inflammation and steatosis in mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Tumor progression locus 2 (TPL2), a serine threonine kinase, functions as a critical regulator of inflammatory pathways and mediates oncogenic events. The potential role of Tpl2 in nonalcoholic fatty liver disease (NAFLD) associated hepatocellular carcinoma (HCC) development remains unkn...

  14. Growth Inhibitory and Tumor- Suppressive Functions of p53 Depend on its Repression of CD44 Expression

    PubMed Central

    Godar, Samuel; Ince, Tan A.; Bell, George W.; Feldser, David; Donaher, Joana Liu; Bergh, Jonas; Liu, Anne; Miu, Kevin; Watnick, Randolph S.; Reinhardt, Ferenc; McAllister, Sandra S.; Jacks, Tyler; Weinberg, Robert A.

    2011-01-01

    SUMMARY The p53 tumor suppressor is a key mediator of cellular responses to various stresses. Here we show that under conditions of basal physiologic and cell-culture stress, p53 inhibits expression of the CD44 cell-surface molecule via binding to a non-canonical p53-binding sequence in the CD44 promoter. This interaction enables an untransformed cell to respond to stress-induced, p53-dependent cytostatic and apoptotic signals that would otherwise be blocked by the actions of CD44. In the absence of p53 function, the resulting de-repressed CD44 expression is essential for the growth and tumor-initiating ability of highly tumorigenic mammary epithelial cells. In both tumorigenic and non-tumorigenic cells, CD44’s expression is positively regulated by p63, a paralogue of p53. Our data indicate that CD44 is a key tumor-promoting agent in transformed tumor cells lacking p53 function. They also suggest that the de-repression of CD44 resulting from inactivation of p53 can potentially aid the survival of immortalized, premalignant, cells. PMID:18614011

  15. Suppression of microtubule dynamics by discodermolide by a novel mechanism is associated with mitotic arrest and inhibition of tumor cell proliferation.

    PubMed

    Honore, Stéphane; Kamath, Kathy; Braguer, Diane; Wilson, Leslie; Briand, Claudette; Jordan, Mary Ann

    2003-12-01

    Discodermolide is a new microtubule-targeted drug in Phase I clinical trials that inhibits tumor growth and induces G(2)-M cell cycle arrest. It is effective against paclitaxel-resistant cell lines and acts synergistically in combination with paclitaxel. Suppression of microtubule dynamics by microtubule-targeted drugs has been hypothesized to be responsible for their ability to inhibit mitotic progression and cell proliferation. To determine whether discodermolide blocks mitosis by an effect on microtubule dynamics, we analyzed the effects of discodermolide on microtubule dynamics in living A549 human lung cancer cells during interphase at concentrations that block mitosis and inhibit cell proliferation. We found that discodermolide (7-166 nM) significantly suppressed microtubule dynamic instability. At the IC(50) for proliferation (7 nM discodermolide, 72 h), overall dynamicity was reduced by 23%. The principal parameters of dynamic instability suppressed by discodermolide were the microtubule shortening rate and length shortened. In addition, discodermolide markedly increased the frequency of rescued catastrophes. At the discodermolide concentration that resulted in 50% of maximal mitotic block (83 nM, 20 h), most microtubules were completely non-dynamic, no anaphases occurred, and all spindles were abnormal. The dynamicity of the remaining dynamic microtubules was reduced by 62%. The results indicate that a principal mechanism of inhibition of cell proliferation and mitotic block by discodermolide is suppression of microtubule dynamics. Importantly, the results indicate significant additional stabilizing effects of discodermolide on microtubule dynamics as compared with those of paclitaxel that may in turn reflect differences in their binding sites and their effects on tubulin conformation.

  16. Theaflavins suppress tumor growth and metastasis via the blockage of the STAT3 pathway in hepatocellular carcinoma

    PubMed Central

    Shao, Jianping; Meng, Qingyan; Li, Yongyuan

    2016-01-01

    Theaflavins, the major black tea polyphenols, have been reported to exhibit promising antitumor activities in several human cancers. However, the role of theaflavins in hepatocellular carcinoma (HCC) is still unknown. In this study, we found that theaflavins could significantly inhibit proliferation, migration, and invasion, and induce apoptosis in HCC cells in vitro. Furthermore, we found that theaflavins inhibited the growth and metastasis of HCC in an orthotopic model and a lung metastasis model. Immunohistochemical analyses and terminal deoxynucleotidyl transferase dUTP nick end-labeling assays showed that theaflavins could suppress proliferation and induce apoptosis in vivo. Theaflavins also suppressed constitutive and inducible signal transducer and activator of transcription 3 (STAT3) phosphorylation. The downstream proteins regulated by STAT3, including the antiapoptotic proteins (Bcl-2 and Survivin) and the invasion-related proteins (MMP-2, MMP-9), were also downregulated after theaflavins treatment. Theaflavins induced apoptosis by activating the caspase pathway. Together, our results suggest that theaflavins suppress the growth and metastasis of human HCC through the blockage of the STAT3 pathway, and thus may act as potential therapeutic agents for HCC. PMID:27478384

  17. MiR-373 targeting of the Rab22a oncogene suppresses tumor invasion and metastasis in ovarian cancer.

    PubMed

    Zhang, Yue; Zhao, Fu-Jun; Chen, Li-Lan; Wang, Luo-Qiao; Nephew, Kenneth P; Wu, Ying-Li; Zhang, Shu

    2014-12-15

    Metastasis is major cause of mortality in patients with ovarian cancer. MiR-373 has been shown to play pivotal roles in tumorigenesis and metastasis; however, a role for miR-373 in ovarian cancer has not been investigated. In this study, we show that the miR-373 expression is down-regulated in human epithelial ovarian cancer (EOC) and inversely correlated with clinical stage and histological grade. Ectopic overexpression of miR-373 in human EOC cells suppressed cell invasion in vitro and metastasis in vivo, and the epithelial-mesenchymal transition process. Silencing the expression of miR-373 resulted in an increased migration and invasion of EOC cells. Using integrated bioinformatics analysis, gene expression arrays, and luciferase assay, we identified Rab22a as a direct and functional target of miR-373 in EOC cells. Expression levels of miR-373 were inversely correlated with Rab22a protein levels in human EOC tissues. Rab22a knockdown inhibited invasion and migration of EOC cells, increased E-cadherin expression, and suppressed the expression of N-cadherin. Moreover, overexpression of Rab22a abrogated miR-373-induced invasion and migration of EOC cells. Taken together, these results demonstrate that miR-373 suppresses EOC invasion and metastasis by directly targeting Rab22a gene, a new potential therapeutic target in EOC.

  18. The Wnt inhibitory factor 1 (WIF1) is targeted in glioblastoma and has a tumor suppressing function potentially by induction of senescence

    PubMed Central

    Lambiv, Wanyu L.; Vassallo, Irene; Delorenzi, Mauro; Shay, Tal; Diserens, Annie-Claire; Misra, Anjan; Feuerstein, Burt; Murat, Anastasia; Migliavacca, Eugenia; Hamou, Marie-France; Sciuscio, Davide; Burger, Raphael; Domany, Eytan; Stupp, Roger; Hegi, Monika E.

    2011-01-01

    Gene expression—based prediction of genomic copy number aberrations in the chromosomal region 12q13 to 12q15 that is flanked by MDM2 and CDK4 identified Wnt inhibitory factor 1 (WIF1) as a candidate tumor suppressor gene in glioblastoma. WIF1 encodes a secreted Wnt antagonist and was strongly downregulated in most glioblastomas as compared with normal brain, implying deregulation of Wnt signaling, which is associated with cancer. WIF1 silencing was mediated by deletion (7/69, 10%) or epigenetic silencing by promoter hypermethylation (29/110, 26%). Co-amplification of MDM2 and CDK4 that is present in 10% of glioblastomas was associated in most cases with deletion of the whole genomic region enclosed, including the WIF1 locus. This interesting pathogenetic constellation targets the RB and p53 tumor suppressor pathways in tandem, while simultaneously activating oncogenic Wnt signaling. Ectopic expression of WIF1 in glioblastoma cell lines revealed a dose-dependent decrease of Wnt pathway activity. Furthermore, WIF1 expression inhibited cell proliferation in vitro, reduced anchorage-independent growth in soft agar, and completely abolished tumorigenicity in vivo. Interestingly, WIF1 overexpression in glioblastoma cells induced a senescence-like phenotype that was dose dependent. These results provide evidence that WIF1 has tumor suppressing properties. Downregulation of WIF1 in 75% of glioblastomas indicates frequent involvement of aberrant Wnt signaling and, hence, may render glioblastomas sensitive to inhibitors of Wnt signaling, potentially by diverting the tumor cells into a senescence-like state. PMID:21642372

  19. The oncogenic triangle of HMGA2, LIN28B and IGF2BP1 antagonizes tumor-suppressive actions of the let-7 family

    PubMed Central

    Busch, Bianca; Bley, Nadine; Müller, Simon; Glaß, Markus; Misiak, Danny; Lederer, Marcell; Vetter, Martina; Strauß, Hans-Georg; Thomssen, Christoph; Hüttelmaier, Stefan

    2016-01-01

    The tumor-suppressive let-7 microRNA family targets various oncogene-encoding mRNAs. We identify the let-7 targets HMGA2, LIN28B and IGF2BP1 to form a let-7 antagonizing self-promoting oncogenic triangle. Surprisingly, 3′-end processing of IGF2BP1 mRNAs is unaltered in aggressive cancers and tumor-derived cells although IGF2BP1 synthesis was proposed to escape let-7 attack by APA-dependent (alternative polyadenylation) 3′ UTR shortening. However, the expression of the triangle factors is inversely correlated with let-7 levels and promoted by LIN28B impairing let-7 biogenesis. Moreover, IGF2BP1 enhances the expression of all triangle factors by recruiting the respective mRNAs in mRNPs lacking AGO proteins and let-7 miRNAs. This indicates that the downregulation of let-7, largely facilitated by LIN28B upregulation, and the protection of let-7 target mRNAs by IGF2BP1-directed shielding in mRNPs synergize in enhancing the expression of triangle factors. The oncogenic potential of this triangle was confirmed in ovarian cancer (OC)-derived ES-2 cells transduced with let-7 targeting decoys. In these, the depletion of HMGA2 only diminishes tumor cell growth under permissive conditions. The depletion of LIN28B and more prominently IGF2BP1 severely impairs tumor cell viability, self-renewal and 2D as well as 3D migration. In conclusion, this suggests the targeting of the HMGA2-LIN28B-IGF2BP1 triangle as a promising strategy in cancer treatment. PMID:26917013

  20. Histone H2AX suppresses translocations in lymphomas of Eμ-c-Myctransgenic mice that contain a germline amplicon of tumor-promoting genes

    PubMed Central

    Fusello, Angela; Horowitz, Julie; Yang-Iott, Katherine; Brady, Brenna L; Yin, Bu; Rowh, Marta AW; Rappaport, Eric; Bassing, Craig H

    2013-01-01

    The DNA damage response (DDR) can restrain the ability of oncogenes to cause genomic instability and drive malignant transformation. The gene encoding the histone H2AX DDR factor maps to 11q23, a region frequently altered in human cancers. Since H2ax functions as a haploinsufficient suppressor of B lineage lymphomas with c-Myc amplification and/or translocation, we determined the impact of H2ax expression on the ability of deregulated c-Myc expression to cause genomic instability and drive transformation of B cells. Neither H2ax deficiency nor haploinsufficiency affected the rate of mortality of Eμ-c-Myc mice from B lineage lymphomas with genomic deletions and amplifications. Yet H2ax functioned in a dosage-dependent manner to prevent unbalanced translocations in Eμ-c-Myc tumors, demonstrating that H2ax functions in a haploinsufficient manner to suppress allelic imbalances and limit molecular heterogeneity within and among Eμ-c-Myc lymphomas. Regardless of H2ax copy number, all Eμ-c-Myc tumors contained identical amplification of chromosome 19 sequences spanning 20 genes. Many of these genes encode proteins with tumor-promoting activities, including Cd274, which encodes the PD-L1 programmed death ligand that induces T cell apoptosis and enables cancer cells to escape immune surveillance. This amplicon was in non-malignant B and T cells and non-lymphoid cells, linked to the Eμ-c-Myc transgene, and associated with overexpression of PD-L1 on non-malignant B cells. Our data demonstrate that, in addition to deregulated c-Myc expression, non-malignant B lineage lymphocytes of Eμ-c-Myc transgenic mice may have constitutive amplification and increased expression of other tumor-promoting genes. PMID:23966158

  1. miR-141 is involved in BRD7-mediated cell proliferation and tumor formation through suppression of the PTEN/AKT pathway in nasopharyngeal carcinoma.

    PubMed

    Liu, Y; Zhao, R; Wang, H; Luo, Y; Wang, X; Niu, W; Zhou, Y; Wen, Q; Fan, S; Li, X; Xiong, W; Ma, J; Li, X; Tan, M; Li, G; Zhou, M

    2016-01-01

    Bromodomain containing 7 (BRD7) was identified as a nuclear transcriptional regulatory factor. BRD7 functions as a tumor suppressor in multiple cancers, including nasopharyngeal carcinoma (NPC). In this study, we reported a novel mechanism of BRD7 in NPC progression. We demonstrated that the expression of miR-141 was remarkably increased in NPC tissues and was negatively correlated with the expression of BRD7 and the survival rate of NPC patients. Decreased expression levels of miR-141, including the primary, the precursor and the mature forms of miR-141, were found in BRD7-overexpressing HEK293, 5-8F and HNE1 cells compared the control cells, while there was no obvious effect on the expression levels of the two critical enzymes Drosha and Dicer. BRD7 can negatively regulate the promoter activity of miR-141, while no obvious binding site of BRD7 was found in the potential promoter region of miR-141. Moreover, ectopic expression of miR-141 can significantly promote cell proliferation and inhibit apoptosis in NPC, and rescuing the expression of miR-141 in BRD7-overexpressing NPC cells could partially reverse the tumor suppressive effect of BRD7 on cell proliferation and tumor growth in vitro and in vivo. Furthermore, the activation of the PTEN/AKT pathway mediated by the overexpression of BRD7 could be inhibited by rescuing the expression of miR-141, which accordingly results in the partial restoration of cell proliferation and tumor growth. Our findings demonstrate that the BRD7/miR-141/PTEN/AKT axis has critical roles in the progression of NPC and provide some promising targets for the diagnosis and treatment of NPC. PMID:27010857

  2. E2F1 plays a direct role in Rb stabilization and p53-independent tumor suppression.

    PubMed

    Palacios, Gustavo; Talos, Flaminia; Nemajerova, Alice; Moll, Ute M; Petrenko, Oleksi

    2008-06-15

    To better understand the role of E2F1 in tumor formation, we analyzed spontaneous tumorigenesis in p53(-/-)E2F1(+/+) and p53(-/-)E2F1(-/-) mice. We show that the combined loss of p53 and E2F1 leads to an increased incidence of sarcomas and carcinomas compared to the loss of p53 alone. E2F1-deficient tumors show wide chromosomal variation, indicative of genomic instability. Consistent with this, p53(-/-)E2F1(-/-) primary fibroblasts have a reduced capacity to maintain genomic stability when exposed to S-phase inhibitors or genotoxic drugs. A major mechanism of E2F1's contribution to genomic integrity lies in mediating stabilization and engagement of the Rb protein.

  3. Suppression of colorectal cancer subcutaneous xenograft and experimental lung metastasis using nanoparticle-mediated drug delivery to tumor neovasculature.

    PubMed

    Wang, Chao; Zhao, Mei; Liu, Ya-Rong; Luan, Xin; Guan, Ying-Yun; Lu, Qin; Yu, De-Hong; Bai, Fan; Chen, Hong-Zhuan; Fang, Chao

    2014-01-01

    Antiangiogenic therapy is a validated approach for colorectal cancer (CRC) treatment. However, diverse adverse effects inevitably appear due to the off-target effect of the approved antiangiogenic inhibitors on the physiological functions and homeostasis. This study was to investigate a new tumor vessel targeting nanoparticulate drug delivery system, F56 peptide conjugated nanoparticles loading vincristine (F56-VCR-NP), for the effective treatment of CRC subcutaneous xenograft and experimental lung metastasis model. The controlled release behavior and in vivo pharmacokinetic profile of F56-VCR-NP were characterized. The tumor vessel targeting and antiangiogenic activity of F56-VCR-NP was evaluated in human umbilical vein endothelial cells (HUVEC, a classical cell model mimicking tumor vascular EC), subcutaneous human HCT-15 xenograft in immunodeficient nude mice, and experimental CT-26 lung metastasis model in immunocompetent mice. The therapeutic efficacy (animal survival and toxicity) was further investigated in the model of CT-26 lung metastasis in mice. F56-VCR-NP could achieve 30-day controlled drug release in PBS (pH 7.4) and exhibited favorable long-circulating feature in vivo. F56-VCR-NP could accurately target the CRC neovasculature and elicit nanoparticle internalization in the tumor vascular EC, where the antiangiogenic VCR-induced dramatic EC apoptosis and necrosis of CRC tissue. F56-VCR-NP significantly prolonged the mouse survival with no obvious toxicity (weight loss and anepithymia) in the CT-26 lung metastasis mice model, and this pronounced antitumor effect was closely related with the decreased microvessel density in the metastases. The present nanoparticle-based targeted antiangiogenic therapy may provide a new promising approach for the therapy of CRC and lung metastasis, which deserves further translational research.

  4. Neem tree (Azadirachta indica) extract specifically suppresses the growth of tumors in H22-bearing Kunming mice.

    PubMed

    He, Zhenxiang; Jiang, Cuihua; Zhang, Jian; Yin, Zhiqi; Yin, Zengfang; Zhu, Yunfeng; Fu, Jie

    2016-01-01

    Recently, neem tree (Azadirachta indica) extract (NTE) has been reported to have various antitumor activities against gastric, breast, prostate, and skin cancer, respectively. The current study was designed to evaluate the effect of NTE on hepatic cancer in a mouse model. The possible side effects elicited by NTE were also evaluated. The components in NTE were analyzed by liquid chromatography-mass spectrometry (LC-MS). H22 cells-bearing Kumming mice were generated by injecting H22 cells subcutaneously into the right forelimb armpit of the mice. Then the mice were treated daily for 27 days with NTE (150, 300, and 600 mg/kg body weight) by intragastric administration, using carboxymethyl cellulose (CMC, 1%) as blank control and cyclophosphamide (CTX, 20 mg/kg) as positive control. The antitumor effect of NTE was evaluated by assessment of survival rate, body weight, tumor volume and weight, tumor histology, thymus and spleen indexes, and liver histology. The tumor weight and volume in groups of NTE and CTX were significantly lower than those in the CMC group. The survival rate in the NTE group receiving the high dose (600 mg/kg) was significantly higher than that in the CTX and CMC groups. Compared with CTX, NTE was observed to have a tumor-specific cytotoxicity without impairing the normal liver tissue. Additionally, the higher indexes of thymus and spleen indicated that NTE could facilitate the growth of immune organs. The results indicate that NTE is a promising candidate for the antitumor treatment with high efficacy and safety.

  5. Neem tree (Azadirachta indica) extract specifically suppresses the growth of tumors in H22-bearing Kunming mice.

    PubMed

    He, Zhenxiang; Jiang, Cuihua; Zhang, Jian; Yin, Zhiqi; Yin, Zengfang; Zhu, Yunfeng; Fu, Jie

    2016-01-01

    Recently, neem tree (Azadirachta indica) extract (NTE) has been reported to have various antitumor activities against gastric, breast, prostate, and skin cancer, respectively. The current study was designed to evaluate the effect of NTE on hepatic cancer in a mouse model. The possible side effects elicited by NTE were also evaluated. The components in NTE were analyzed by liquid chromatography-mass spectrometry (LC-MS). H22 cells-bearing Kumming mice were generated by injecting H22 cells subcutaneously into the right forelimb armpit of the mice. Then the mice were treated daily for 27 days with NTE (150, 300, and 600 mg/kg body weight) by intragastric administration, using carboxymethyl cellulose (CMC, 1%) as blank control and cyclophosphamide (CTX, 20 mg/kg) as positive control. The antitumor effect of NTE was evaluated by assessment of survival rate, body weight, tumor volume and weight, tumor histology, thymus and spleen indexes, and liver histology. The tumor weight and volume in groups of NTE and CTX were significantly lower than those in the CMC group. The survival rate in the NTE group receiving the high dose (600 mg/kg) was significantly higher than that in the CTX and CMC groups. Compared with CTX, NTE was observed to have a tumor-specific cytotoxicity without impairing the normal liver tissue. Additionally, the higher indexes of thymus and spleen indicated that NTE could facilitate the growth of immune organs. The results indicate that NTE is a promising candidate for the antitumor treatment with high efficacy and safety. PMID:27248120

  6. GSK1838705A, an IGF-1R inhibitor, inhibits glioma cell proliferation and suppresses tumor growth in vivo.

    PubMed

    Zhou, Xiang; Shen, Fazheng; Ma, Pengju; Hui, Hongyan; Pei, Sujuan; Chen, Ming; Wang, Zhongwei; Zhou, Wenke; Jin, Baozhe

    2015-10-01

    Glioma is a type of primary malignant tumor of the central nervous system in humans. At present, standard treatment involves surgical resection, followed by radiation therapy and chemotherapy. However, the prognosis is poor and the long‑term survival rate remains low. An improved understanding of the molecular basis for glioma tumorigenesis is in urgently required. The pro‑survival effect of the insulin‑like growth factor (IGF) signaling pathway has been implicated in progression of the glioma disease state. GSK1838705A is a novel, small molecule kinase inhibitor of IGF‑IR, which inhibits IGF signal transduction and downstream target activation. Its anti-proliferative activity has been demonstrated in various tumor cell lines. The present study investigated the potential use of GSK1838705A for the treatment of glioma. Human U87MG glioma cells were used to examine the inhibitory activity of GSK1838705A in cell proliferation, migration and apoptosis. The antitumor activity of GSK1838705A was assessed in a xenograft mouse model. GSK1838705A inhibited the growth and induced the apoptosis of the U87MG glioma cells in a dose‑dependent manner. The GSK1838705A‑treated cells exhibited reduced migratory activity in response to chemoattractants. The present study further demonstrated the antitumor activity of GSK1838705A in vivo. The administration of GSK1838705A significantly inhibited the growth of glioma tumors by inducing the apoptosis of tumor cells. These results suggested that targeting IGF signaling with GSK1838705A may be a promising therapeutic strategy for the treatment of patients with glioma. PMID:26238593

  7. GSK1838705A, an IGF-1R inhibitor, inhibits glioma cell proliferation and suppresses tumor growth in vivo

    PubMed Central

    ZHOU, XIANG; SHEN, FAZHENG; MA, PENGJU; HUI, HONGYAN; PEI, SUJUAN; CHEN, MING; WANG, ZHONGWEI; ZHOU, WENKE; JIN, BAOZHE

    2015-01-01

    Glioma is a type of primary malignant tumor of the central nervous system in humans. At present, standard treatment involves surgical resection, followed by radiation therapy and chemotherapy. However, the prognosis is poor and the long-term survival rate remains low. An improved understanding of the molecular basis for glioma tumorigenesis is in urgently required. The pro-survival effect of the insulin-like growth factor (IGF) signaling pathway has been implicated in progression of the glioma disease state. GSK1838705A is a novel, small molecule kinase inhibitor of IGF-IR, which inhibits IGF signal transduction and downstream target activation. Its anti-proliferative activity has been demonstrated in various tumor cell lines. The present study investigated the potential use of GSK1838705A for the treatment of glioma. Human U87MG glioma cells were used to examine the inhibitory activity of GSK1838705A in cell proliferation, migration and apoptosis. The antitumor activity of GSK1838705A was assessed in a xenograft mouse model. GSK1838705A inhibited the growth and induced the apoptosis of the U87MG glioma cells in a dose-dependent manner. The GSK1838705A-treated cells exhibited reduced migratory activity in response to chemoattractants. The present study further demonstrated the antitumor activity of GSK1838705A in vivo. The administration of GSK1838705A significantly inhibited the growth of glioma tumors by inducing the apoptosis of tumor cells. These results suggested that targeting IGF signaling with GSK1838705A may be a promising therapeutic strategy for the treatment of patients with glioma. PMID:26238593

  8. Tumor-suppressing effects of microRNA-429 in human renal cell carcinoma via the downregulation of Sp1

    PubMed Central

    Wu, Deyao; Niu, Xiaobing; Pan, Huixing; Zhou, Yunfeng; Zhang, Zichun; Qu, Ping; Zhou, Jian

    2016-01-01

    MicroRNA (miR)-429 has been frequently reported to be downregulated in various tumors, including renal cell carcinoma (RCC), nasopharyngeal carcinoma, Ehrlich ascites tumor cells, gastric cancer, non-small cell lung cancer and endometrial endometrioid carcinoma. The present study investigated the effects of miR-429 on human RCC A498 and 786-O cells. Following transfection of cells with miR-429 mimics and scrambled control, MTT, cell migration, cell invasion and luciferase assays were performed. In addition, western blotting was performed in order to assess the expression of specificity protein 1 (Sp1), which was predicted to be a target of miR-429 by TargetScan. The present results revealed that miR-429 inhibited cell proliferation, migration and invasion of 786-O and A498 cells. In addition, the present results demonstrated that miR-429 overexpression downregulated Sp1 protein expression, which provides evidence that miR-429 may directly target Sp1 in RCC. These results suggest that miR-429 may be investigated for use as a predictive marker for early detection of tumor metastasis and blocking RCC cells from becoming invasive.

  9. NSK-01105, a Novel Sorafenib Derivative, Inhibits Human Prostate Tumor Growth via Suppression of VEGFR2/EGFR-Mediated Angiogenesis

    PubMed Central

    Yu, Pengfei; Ye, Liang; Wang, Hongbo; Du, Guangying; Zhang, Jianzhao; Zuo, Yanhua; Zhang, Jinghai; Tian, Jingwei

    2014-01-01

    The purpose of this study is to investigate the anti-angiogenic activities of NSK-01105, a novel sorafenib derivative, in in vitro, ex vivo and in vivo models, and explore the potential mechanisms. NSK-01105 significantly inhibited vascular endothelial growth factor (VEGF)-induced migration and tube formation of human umbilical vein endothelial cells at non-cytotoxic concentrations as shown by wound-healing, transwell migration and endothelial cell tube formation assays, respectively. Cell viability and invasion of LNCaP and PC-3 cells were significantly inhibited by cytotoxicity assay and matrigel invasion assay. Furthermore, NSK-01105 also inhibited ex vivo angiogenesis in matrigel plug assay. Western blot analysis showed that NSK-01105 down-regulated VEGF-induced phosphorylation of VEGF receptor 2 (VEGFR2) and the activation of epidermal growth factor receptor (EGFR). Tumor volumes were significantly reduced by NSK-01105 at 60 mg/kg/day in both xenograft models. Immunohistochemical staining demonstrated a close association between inhibition of tumor growth and neovascularization. Collectively, our results suggest a role of NSK-01105 in treatment for human prostate tumors, and one of the potential mechanisms may be attributed to anti-angiogenic activities. PMID:25551444

  10. Erucin, the Major Isothiocyanate in Arugula (Eruca sativa), Inhibits Proliferation of MCF7 Tumor Cells by Suppressing Microtubule Dynamics

    PubMed Central

    Azarenko, Olga; Jordan, Mary Ann; Wilson, Leslie

    2014-01-01

    Consumption of cruciferous vegetables is associated with reduced risk of various types of cancer. Isothiocyanates including sulforaphane and erucin are believed to be responsible for this activity. Erucin [1-isothiocyanato-4-(methylthio)butane], which is metabolically and structurally related to sulforaphane, is present in large quantities in arugula (Eruca sativa, Mill.), kohlrabi and Chinese cabbage. However, its cancer preventive mechanisms remain poorly understood. We found that erucin inhibits proliferation of MCF7 breast cancer cells (IC50 = 28 µM) in parallel with cell cycle arrest at mitosis (IC50 = 13 µM) and apoptosis, by a mechanism consistent with impairment of microtubule dynamics. Concentrations of 5–15 µM erucin suppressed the dynamic instability of microtubules during interphase in the cells. Most dynamic instability parameters were inhibited, including the rates and extents of growing and shortening, the switching frequencies between growing and shortening, and the overall dynamicity. Much higher erucin concentrations were required to reduce the microtubule polymer mass. In addition, erucin suppressed dynamic instability of microtubules reassembled from purified tubulin in similar fashion. The effects of erucin on microtubule dynamics, like those of sulforaphane, are similar qualitatively to those of much more powerful clinically-used microtubule-targeting anticancer drugs, including taxanes and the vinca alkaloids. The results suggest that suppression of microtubule dynamics by erucin and the resulting impairment of critically important microtubule-dependent cell functions such as mitosis, cell migration and microtubule-based transport may be important in its cancer preventive activities. PMID:24950293

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

    PubMed

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

    2016-05-01

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

  12. Pigment epithelial-derived factor gene loaded novel COOH-PEG-PLGA-COOH nanoparticles promoted tumor suppression by systemic administration

    PubMed Central

    Yu, Ting; Xu, Bei; He, Lili; Xia, Shan; Chen, Yan; Zeng, Jun; Liu, Yongmei; Li, Shuangzhi; Tan, Xiaoyue; Ren, Ke; Yao, Shaohua; Song, Xiangrong

    2016-01-01

    Anti-angiogenesis has been proposed as an effective therapeutic strategy for cancer treatment. Pigment epithelium-derived factor (PEDF) is one of the most powerful endogenous anti-angiogenic reagents discovered to date and PEDF gene therapy has been recognized as a promising treatment option for various tumors. There is an urgent need to develop a safe and valid vector for its systemic delivery. Herein, a novel gene delivery system based on the newly synthesized copolymer COOH-PEG-PLGA-COOH (CPPC) was developed in this study, which was probably capable of overcoming the disadvantages of viral vectors and cationic lipids/polymers-based nonviral carriers. PEDF gene loaded CPPC nanoparticles (D-NPs) were fabricated by a modified double-emulsion water-in-oil-in-water (W/O/W) solvent evaporation method. D-NPs with uniform spherical shape had relatively high drug loading (~1.6%), probably because the introduced carboxyl group in poly (D,L-lactide-co-glycolide) terminal enhanced the interaction of copolymer with the PEDF gene complexes. An excellent in vitro antitumor effect was found in both C26 and A549 cells treated by D-NPs, in which PEDF levels were dramatically elevated due to the successful transfection of PEDF gene. D-NPs also showed a strong inhibitory effect on proliferation of human umbilical vein endothelial cells in vitro and inhibited the tumor-induced angiogenesis in vivo by an alginate-encapsulated tumor cell assay. Further in vivo antitumor investigation, carried out in a C26 subcutaneous tumor model by intravenous injection, demonstrated that D-NPs could achieve a significant antitumor activity with sharply reduced microvessel density and significantly promoted tumor cell apoptosis. Additionally, the in vitro hemolysis analysis and in vivo serological and biochemical analysis revealed that D-NPs had no obvious toxicity. All the data indicated that the novel CPPC nanoparticles were ideal vectors for the systemic delivery of PEDF gene and might be widely

  13. Pigment epithelial-derived factor gene loaded novel COOH-PEG-PLGA-COOH nanoparticles promoted tumor suppression by systemic administration.

    PubMed

    Yu, Ting; Xu, Bei; He, Lili; Xia, Shan; Chen, Yan; Zeng, Jun; Liu, Yongmei; Li, Shuangzhi; Tan, Xiaoyue; Ren, Ke; Yao, Shaohua; Song, Xiangrong

    2016-01-01

    Anti-angiogenesis has been proposed as an effective therapeutic strategy for cancer treatment. Pigment epithelium-derived factor (PEDF) is one of the most powerful endogenous anti-angiogenic reagents discovered to date and PEDF gene therapy has been recognized as a promising treatment option for various tumors. There is an urgent need to develop a safe and valid vector for its systemic delivery. Herein, a novel gene delivery system based on the newly synthesized copolymer COOH-PEG-PLGA-COOH (CPPC) was developed in this study, which was probably capable of overcoming the disadvantages of viral vectors and cationic lipids/polymers-based nonviral carriers. PEDF gene loaded CPPC nanoparticles (D-NPs) were fabricated by a modified double-emulsion water-in-oil-in-water (W/O/W) solvent evaporation method. D-NPs with uniform spherical shape had relatively high drug loading (~1.6%), probably because the introduced carboxyl group in poly (D,L-lactide-co-glycolide) terminal enhanced the interaction of copolymer with the PEDF gene complexes. An excellent in vitro antitumor effect was found in both C26 and A549 cells treated by D-NPs, in which PEDF levels were dramatically elevated due to the successful transfection of PEDF gene. D-NPs also showed a strong inhibitory effect on proliferation of human umbilical vein endothelial cells in vitro and inhibited the tumor-induced angiogenesis in vivo by an alginate-encapsulated tumor cell assay. Further in vivo antitumor investigation, carried out in a C26 subcutaneous tumor model by intravenous injection, demonstrated that D-NPs could achieve a significant antitumor activity with sharply reduced microvessel density and significantly promoted tumor cell apoptosis. Additionally, the in vitro hemolysis analysis and in vivo serological and biochemical analysis revealed that D-NPs had no obvious toxicity. All the data indicated that the novel CPPC nanoparticles were ideal vectors for the systemic delivery of PEDF gene and might be widely

  14. Hwanggeumchal sorghum Induces Cell Cycle Arrest, and Suppresses Tumor Growth and Metastasis through Jak2/STAT Pathways in Breast Cancer Xenografts

    PubMed Central

    Lim, Eun Joung; Joung, Youn Hee; Hong, Dae Young; Park, Eui U.; Park, Seung Hwa; Choi, Soo Keun; Moon, Eon-Soo; Cho, Byung Wook; Park, Kyung Do; Lee, Hak Kyo; Kim, Myong-Jo; Park, Dong-Sik; Yang, Young Mok

    2012-01-01

    Background Cancer is one of the highly virulent diseases known to humankind with a high mortality rate. Breast cancer is the most common cancer in women worldwide. Sorghum is a principal cereal food in many parts of the world, and is critical in folk medicine of Asia and Africa. In the present study, we analyzed the effects of HSE in metastatic breast cancer. Methodology/Principal Findings Preliminary studies conducted on MDA-MB 231 and MCF-7 xenograft models showed tumor growth suppression by HSE. Western blotting studies conducted both in vivo and in vitro to check the effect of HSE in Jak/STAT pathways. Anti-metastatic effects of HSE were confirmed using both MDA-MB 231 and MCF-7 metastatic animal models. These studies showed that HSE can modulate Jak/STAT pathways, and it hindered the STAT5b/IGF-1R and STAT3/VEGF pathways not only by down-regulating the expression of these signal molecules and but also by preventing their phosphorylation. The expression of angiogenic factors like VEGF, VEGF-R2 and cell cycle regulators like cyclin D, cyclin E, and pRb were found down-regulated by HSE. In addition, it also targets Brk, p53, and HIF-1α for anti-cancer effects. HSE induced G1 phase arrest and migration inhibition in MDA-MB 231 cells. The metastasis of breast cancer to the lungs also found blocked by HSE in the metastatic animal model. Conclusions/Significance Usage of HS as a dietary supplement is an inexpensive natural cancer therapy, without any side effects. We strongly recommend the use of HS as an edible therapeutic agent as it possesses tumor suppression, migration inhibition, and anti-metastatic effects on breast cancer. PMID:22792362

  15. miR-144-3p, a tumor suppressive microRNA targeting ETS-1 in laryngeal squamous cell carcinoma

    PubMed Central

    Lin, Ye-Feng; Chen, Liang-Si; Luo, Xiao-Ning; Song, Xin-Han; Chen, Shao-Hua; Wu, Yi-Long

    2016-01-01

    Regional lymph node metastasis and distant metastasis are critical in the prognosis of laryngeal squamous cell carcinoma (LSCC). This study investigated the roles of miR-144-3p and E26 transformation specific-1 (ETS-1) in the invasion and migration of LSCC cells. The effects of miR-144-3p and ETS-1 on FaDu and Hep2 cell growth, migration and invasion were determined. Suppression of ETS-1 by miR-144-3p was confirmed using luciferase assays; the effects of ETS-1 silencing were determined using a xenograft tumor model. The expression of ETS-1 was analyzed in 71 paraffin-embedded tissue biopsies and eight fresh frozen biopsies obtained from LSCC patients. miR-144-3p inhibited the growth, invasion and migration of FaDu and Hep2 cells in part through suppression of epithelial-mesenchymal transition as determined by increased E-cadherin and α-catenin and reduced fibronectin and vimentin expression. Additionally, ETS-1 is a molecular target of miR-144-3p, and silencing ETS-1 expression inhibited FaDu and Hep2 cell invasion and migration as well as reduced Hep2 xenograft tumor volume. In LSCC, the expression of ETS-1 is upregulated with disease progression, and higher ETS-1 expression, which was negatively associated with miR-144-3p levels, adversely corresponded with prognoses. Thus, upregulated ETS-1 levels may promote LSCC metastasis, resulting in poor patient prognosis. PMID:26826553

  16. Physalin A exerts anti-tumor activity in non-small cell lung cancer cell lines by suppressing JAK/STAT3 signaling

    PubMed Central

    Loo, Jacky F.C.; Xia, Dajin; Gao, Sizhi P.; Ma, Zhongjun; Chen, Zhe

    2016-01-01

    The signal transducers and activators of transcription 3 (STAT3) signaling pathway plays critical roles in the pathogenesis and progression of various human cancers, including non-small cell lung cancer (NSCLC). In this study, we aimed to evaluate the therapeutic potential of physalin A, a bioactive withanolide derived from Physalis alkekengi var. francheti used in traditional Chinese medicine, was evaluated in human NSCLC cells. Its and determined whether it effect oninhibited both constitutive and induced STAT3 activity, through repressing the phosphorylation levels of JAK2 and JAK3, resulting in anti-proliferation and pro-apoptotic effects on NSCLC cells was also determined, and. theThe antitumor effects of physalin A were also validated usingin an in vivo mouse xenograft models of NSCLC cells. Physalin A had anti-proliferative and pro-apoptotic effects in NSCLC cells with constitutively activated STAT3; it also suppressed both constitutive and induced STAT3 activity by modulating the phosphorylation of JAK2 and JAK3. Furthermore, physalin A abrogated the nuclear translocation and transcriptional activity of STAT3, thereby decreasing the expression levels of STAT3, its target genes, such as Bcl-2 and XIAP. Knockdown of STAT3 expression by small interfering RNA (siRNA) significantly enhanced the pro-apoptotic effects of physalin A in NSCLC cells. Moreover, physalin A significantly suppressed tumor xenograft growth. Thus, as an inhibitor of JAK2/3-STAT3 signaling, physalin A, has potent anti-tumor activities, which may facilitate the development of a therapeutic strategy for treating NSCLC. PMID:26843613

  17. The Tumor Suppressive Role of eIF3f and Its Function in Translation Inhibition and rRNA Degradation

    PubMed Central

    Wen, Fushi; Zhou, Renyuan; Shen, Alex; Choi, Andrew; Uribe, Diana; Shi, Jiaqi

    2012-01-01

    Deregulated translation plays an important role in human cancer. We previously reported decreased eukaryotic initiation factor 3 subunit f (eIF3f) expression in pancreatic cancer. Whether decreased eIF3f expression can transform normal epithelial cells is not known. In our current study, we found evidence that stable knockdown of eIF3f in normal human pancreatic ductal epithelial cells increased cell size, nuclear pleomorphism, cytokinesis defects, cell proliferation, clonogenicity, apoptotic resistance, migration, and formation of 3-dimensional irregular masses. Our findings support the tumor suppressive role of eIF3f in pancreatic cancer. Mechanistically, we found that eIF3f inhibited both cap-dependent and cap-independent translation. An increase in the ribosomal RNA (rRNA) level was suggested to promote the generation of cancer. The regulatory mechanism of rRNA degradation in mammals is not well understood. We demonstrated here that eIF3f promotes rRNA degradation through direct interaction with heterogeneous nuclear ribonucleoprotein (hnRNP) K. We showed that hnRNP K is required for maintaining rRNA stability: under stress conditions, eIF3f dissociates hnRNP K from rRNA, thereby preventing it from protecting rRNA from degradation. We also demonstrated that rRNA degradation occurred in non-P body, non-stress granule cytoplasmic foci that contain eIF3f. Our findings established a new mechanism of rRNA decay regulation mediated by hnRNP K/eIF3f and suggest that the tumor suppressive function of eIF3f may link to impaired rRNA degradation and translation. PMID:22457825

  18. miR-144-3p, a tumor suppressive microRNA targeting ETS-1 in laryngeal squamous cell carcinoma.

    PubMed

    Zhang, Si-Yi; Lu, Zhong-Ming; Lin, Ye-Feng; Chen, Liang-Si; Luo, Xiao-Ning; Song, Xin-Han; Chen, Shao-Hua; Wu, Yi-Long

    2016-03-01

    Regional lymph node metastasis and distant metastasis are critical in the prognosis of laryngeal squamous cell carcinoma (LSCC). This study investigated the roles of miR-144-3p and E26 transformation specific-1 (ETS-1) in the invasion and migration of LSCC cells. The effects of miR-144-3p and ETS-1 on FaDu and Hep2 cell growth, migration and invasion were determined. Suppression of ETS-1 by miR-144-3p was confirmed using luciferase assays; the effects of ETS-1 silencing were determined using a xenograft tumor model. The expression of ETS-1 was analyzed in 71 paraffin-embedded tissue biopsies and eight fresh frozen biopsies obtained from LSCC patients. miR-144-3p inhibited the growth, invasion and migration of FaDu and Hep2 cells in part through suppression of epithelial-mesenchymal transition as determined by increased E-cadherin and α-catenin and reduced fibronectin and vimentin expression. Additionally, ETS-1 is a molecular target of miR-144-3p, and silencing ETS-1 expression inhibited FaDu and Hep2 cell invasion and migration as well as reduced Hep2 xenograft tumor volume. In LSCC, the expression of ETS-1 is upregulated with disease progression, and higher ETS-1 expression, which was negatively associated with miR-144-3p levels, adversely corresponded with prognoses. Thus, upregulated ETS-1 levels may promote LSCC metastasis, resulting in poor patient prognosis.

  19. Transforming growth factor-alpha abrogates glucocorticoid-stimulated tight junction formation and growth suppression in rat mammary epithelial tumor cells.

    PubMed

    Buse, P; Woo, P L; Alexander, D B; Cha, H H; Reza, A; Sirota, N D; Firestone, G L

    1995-03-24

    The glucocorticoid and transforming growth factor-alpha (TGF-alpha) regulation of growth and cell-cell contact was investigated in the Con8 mammary epithelial tumor cell line derived from a 7,12-dimethylbenz(alpha)anthracene-induced rat mammary adenocarcinoma. In Con8 cell monolayers cultured on permeable filter supports, the synthetic glucocorticoid, dexamethasone, coordinately suppressed [3H]thymidine incorporation, stimulated monolayer transepithelial electrical resistance (TER), and decreased the paracellular leakage of [3H]inulin or [14C]mannitol across the monolayer. These processes dose dependently correlated with glucocorticoid receptor occupancy and function. Constitutive production of TGF-alpha in transfected cells or exogenous treatment with TGF-alpha prevented the glucocorticoid growth suppression response and disrupted tight junction formation without affecting glucocorticoid responsiveness. Treatment with hydroxyurea or araC demonstrated that de novo DNA synthesis is not a requirement for the growth factor disruption of tight junctions. Immunofluorescence analysis revealed that the ZO-1 tight junction protein is localized exclusively at the cell periphery in dexamethasone-treated cells and that TGF-alpha caused-ZO-1 to relocalize from the cell periphery back to a cytoplasmic compartment. Taken together, our results demonstrate that glucocorticoids can coordinately regulate growth inhibition and cell-cell contact of mammary tumor cells and that TGF-alpha, can override both effects of glucocorticoids. These results have uncovered a novel functional "cross-talk" between glucocorticoids and TGF-alpha which potentially regulates the proliferation and differentiation of mammary epithelial cells.

  20. Activation of lytic cycle of Epstein-Barr virus by suberoylanilide hydroxamic acid leads to apoptosis and tumor growth suppression of nasopharyngeal carcinoma.

    PubMed

    Hui, K F; Ho, Dona N; Tsang, C M; Middeldorp, Jaap M; Tsao, George S W; Chiang, Alan K S

    2012-10-15

    Nasopharyngeal carcinoma (NPC) is strongly associated with Epstein-Barr virus (EBV). We reported that suberoylanilide hydroxamic acid (SAHA) induced EBV lytic cycle in EBV-positive gastric carcinoma cells and mediated enhanced cell death. However, expression of EBV lytic proteins was thought to exert antiapoptotic effect in EBV-infected cells. Here, we examined the in vitro and in vivo effects of SAHA on EBV lytic cycle induction in NPC cells and investigated the cellular consequences. Micromolar concentrations of SAHA significantly induced EBV lytic cycle in EBV-positive NPC cells. Increased apoptosis and proteolytic cleavage of poly(ADP-ribose) polymerase and caspase-3, -7 and -9 in EBV-positive versus EBV-negative NPC cells were observed. More than 85% of NPC cells expressing immediate-early (Zta), early (BMRF1) or late (gp350/220) lytic proteins coexpressed cleaved caspase-3. Tracking of expression of EBV lytic proteins and cleaved caspase-3 over time demonstrated that NPC cells proceeded to apoptosis following EBV lytic cycle induction. Inhibition of EBV DNA replication and late lytic protein expression by phosphonoformic acid did not impact on SAHA's induced cell death in NPC, indicating that early rather than late phase of EBV lytic cycle contributed to the apoptotic effect. In vivo effects of SAHA on EBV lytic cycle induction and tumor growth suppression were also observed in NPC xenografts in nude mice. Taken together, our data indicated that activation of lytic cycle from latent cycle of EBV by SAHA leads to apoptosis and tumor growth suppression of NPC thereby providing experimental evidence for virus-targeted therapy against EBV-positive cancer.

  1. TGF-β/β2-spectrin/CTCF-regulated tumor suppression in human stem cell disorder Beckwith-Wiedemann syndrome.

    PubMed

    Chen, Jian; Yao, Zhi-Xing; Chen, Jiun-Sheng; Gi, Young Jin; Muñoz, Nina M; Kundra, Suchin; Herlong, H Franklin; Jeong, Yun Seong; Goltsov, Alexei; Ohshiro, Kazufumi; Mistry, Nipun A; Zhang, Jianping; Su, Xiaoping; Choufani, Sanaa; Mitra, Abhisek; Li, Shulin; Mishra, Bibhuti; White, Jon; Rashid, Asif; Wang, Alan Yaoqi; Javle, Milind; Davila, Marta; Michaely, Peter; Weksberg, Rosanna; Hofstetter, Wayne L; Finegold, Milton J; Shay, Jerry W; Machida, Keigo; Tsukamoto, Hidekazu; Mishra, Lopa

    2016-02-01

    Beckwith-Wiedemann syndrome (BWS) is a human stem cell disorder, and individuals with this disease have a substantially increased risk (~800-fold) of developing tumors. Epigenetic silencing of β2-spectrin (β2SP, encoded by SPTBN1), a SMAD adaptor for TGF-β signaling, is causally associated with BWS; however, a role of TGF-β deficiency in BWS-associated neoplastic transformation is unexplored. Here, we have reported that double-heterozygous Sptbn1+/- Smad3+/- mice, which have defective TGF-β signaling, develop multiple tumors that are phenotypically similar to those of BWS patients. Moreover, tumorigenesis-associated genes IGF2 and telomerase reverse transcriptase (TERT) were overexpressed in fibroblasts from BWS patients and TGF-β-defective mice. We further determined that chromatin insulator CCCTC-binding factor (CTCF) is TGF-β inducible and facilitates TGF-β-mediated repression of TERT transcription via interactions with β2SP and SMAD3. This regulation was abrogated in TGF-β-defective mice and BWS, resulting in TERT overexpression. Imprinting of the IGF2/H19 locus and the CDKN1C/KCNQ1 locus on chromosome 11p15.5 is mediated by CTCF, and this regulation is lost in BWS, leading to aberrant overexpression of growth-promoting genes. Therefore, we propose that loss of CTCF-dependent imprinting of tumor-promoting genes, such as IGF2 and TERT, results from a defective TGF-β pathway and is responsible at least in part for BWS-associated tumorigenesis as well as sporadic human cancers that are frequently associated with SPTBN1 and SMAD3 mutations.

  2. TGF-β/β2-spectrin/CTCF-regulated tumor suppression in human stem cell disorder Beckwith-Wiedemann syndrome

    PubMed Central

    Chen, Jian; Yao, Zhi-Xing; Chen, Jiun-Sheng; Gi, Young Jin; Muñoz, Nina M.; Kundra, Suchin; Herlong, H. Franklin; Jeong, Yun Seong; Goltsov, Alexei; Ohshiro, Kazufumi; Mistry, Nipun A.; Zhang, Jianping; Su, Xiaoping; Choufani, Sanaa; Mitra, Abhisek; Li, Shulin; Mishra, Bibhuti; White, Jon; Rashid, Asif; Wang, Alan Yaoqi; Javle, Milind; Davila, Marta; Michaely, Peter; Weksberg, Rosanna; Hofstetter, Wayne L.; Finegold, Milton J.; Shay, Jerry W.; Machida, Keigo; Tsukamoto, Hidekazu; Mishra, Lopa

    2016-01-01

    Beckwith-Wiedemann syndrome (BWS) is a human stem cell disorder, and individuals with this disease have a substantially increased risk (~800-fold) of developing tumors. Epigenetic silencing of β2-spectrin (β2SP, encoded by SPTBN1), a SMAD adaptor for TGF-β signaling, is causally associated with BWS; however, a role of TGF-β deficiency in BWS-associated neoplastic transformation is unexplored. Here, we have reported that double-heterozygous Sptbn1+/– Smad3+/– mice, which have defective TGF-β signaling, develop multiple tumors that are phenotypically similar to those of BWS patients. Moreover, tumorigenesis-associated genes IGF2 and telomerase reverse transcriptase (TERT) were overexpressed in fibroblasts from BWS patients and TGF-β–defective mice. We further determined that chromatin insulator CCCTC-binding factor (CTCF) is TGF-β inducible and facilitates TGF-β–mediated repression of TERT transcription via interactions with β2SP and SMAD3. This regulation was abrogated in TGF-β–defective mice and BWS, resulting in TERT overexpression. Imprinting of the IGF2/H19 locus and the CDKN1C/KCNQ1 locus on chromosome 11p15.5 is mediated by CTCF, and this regulation is lost in BWS, leading to aberrant overexpression of growth-promoting genes. Therefore, we propose that loss of CTCF-dependent imprinting of tumor-promoting genes, such as IGF2 and TERT, results from a defective TGF-β pathway and is responsible at least in part for BWS-associated tumorigenesis as well as sporadic human cancers that are frequently associated with SPTBN1 and SMAD3 mutations. PMID:26784546

  3. Tetrandrine Inhibits Wnt/β-Catenin Signaling and Suppresses Tumor Growth of Human Colorectal CancerS⃞

    PubMed Central

    He, Bai-Cheng; Gao, Jian-Li; Zhang, Bing-Qiang; Luo, Qing; Shi, Qiong; Kim, Stephanie H.; Huang, Enyi; Gao, Yanhong; Yang, Ke; Wagner, Eric R.; Wang, Linyuan; Tang, Ni; Luo, Jinyong; Liu, Xing; Li, Mi; Bi, Yang; Shen, Jikun; Luther, Gaurav; Hu, Ning; Zhou, Qixin; Luu, Hue H.; Haydon, Rex C.; Zhao, Yingming

    2011-01-01

    As one of the most common malignancies, colon cancer is initiated by abnormal activation of the Wnt/β-catenin pathway. Although the treatment options have increased for some patients, overall progress has been modest. Thus, there is a great need to develop new treatments. We have found that bisbenzylisoquinoline alkaloid tetrandrine (TET) exhibits anticancer activity. TET is used as a calcium channel blocker to treat hypertensive and arrhythmic conditions in Chinese medicine. Here, we investigate the molecular basis underlying TET's anticancer activity. We compare TET with six chemotherapy drugs in eight cancer lines and find that TET exhibits comparable anticancer activities with camptothecin, vincristine, paclitaxel, and doxorubicin, and better than that of 5-fluorouracil (5-FU) and carboplatin. TET IC50 is ≤5 μM in most of the tested cancer lines. TET exhibits synergistic anticancer activity with 5-FU and reduces migration and invasion capabilities of HCT116 cells. Furthermore, TET induces apoptosis and inhibits xenograft tumor growth of colon cancer. TET treatment leads to a decrease in β-catenin protein level in xenograft tumors, which is confirmed by T-cell factor/lymphocyte enhancer factor and c-Myc reporter assays. It is noteworthy that HCT116 cells with allelic oncogenic β-catenin deleted are less sensitive to TET-mediated inhibition of proliferation, viability, and xenograft tumor growth. Thus, our findings strongly suggest that the anticancer effect of TET in colon cancer may be at least in part mediated by targeting β-catenin activity. Therefore, TET may be used alone or in combination as an effective anticancer agent. PMID:20978119

  4. Tumor Cellular Proteasome Inhibition and Growth Suppression by 8-Hydroxyquinoline and Clioquinol Requires Their Capabilities to Bind Copper and Transport Copper into Cells

    PubMed Central

    Zhai, Shumei; Yang, Lei; Cui, Qiuzhi Cindy; Sun, Ying; Dou, Q. Ping; Yan, Bing

    2009-01-01

    We have previously reported that when mixed with copper, 8-hydroxyquinoline (8-OHQ) and its analog clioquinol (CQ) inhibited the proteasomal activity and proliferation in cultured human cancer cells. CQ treatment of high copper-containing human tumor xenografts also caused cancer suppression, associated with proteasome inhibition in vivo. However, the nature of copper dependence of these events has not been elucidated experimentally. In the current study, by using chemical probe molecules that mimic structures of 8-OHQ and CQ, but have no copper binding capability, we dissected the complex cellular processes elicited by 8-OHQ-Cu or CQ-Cu mixture and revealed that copper-binding to 8-OHQ or CQ is required for transportation of copper complex into human breast cancer cells and the consequent proteasome-inhibitory, growth-suppressive and apoptosis-inducing activities. In contrast, the non-copper-binding analogs of 8-OHQ or CQ blocked the very first step – copper binding in this chain of events mediated by 8-OHQ-Cu or CQ-Cu. PMID:19809836

  5. Knockdown of Oncogenic KRAS in Non-Small Cell Lung Cancers Suppresses Tumor Growth and Sensitizes Tumor Cells to Targeted Therapy

    PubMed Central

    Sunaga, Noriaki; Shames, David S.; Girard, Luc; Peyton, Michael; Larsen, Jill E.; Imai, Hisao; Soh, Junichi; Sato, Mitsuo; Yanagitani, Noriko; Kaira, Kyoichi; Xie, Yang; Gazdar, Adi F.; Mori, Masatomo; Minna, John D.

    2011-01-01

    Oncogenic KRAS is found in >25% of lung adenocarcinomas, the major histologic subtype of non-small cell lung cancer (NSCLC), and is an important target for drug development. To this end, we generated four NSCLC lines with stable knockdown selective for oncogenic KRAS. As expected, stable knockdown of oncogenic KRAS led to inhibition of in vitro and in vivo tumor growth in the KRAS mutant NSCLC cells, but not in NSCLC cells that have wild-type KRAS (but mutant NRAS). Surprisingly, we did not see large-scale induction of cell death and the growth inhibitory effect was not complete. To further understand the ability of NSCLCs to grow despite selective removal of mutant KRAS expression, we performed microarray expression profiling of NSCLC cell lines with or without mutant KRAS knockdown and isogenic human bronchial epithelial cell lines (HBECs) with and without oncogenic KRAS. We found that while the MAPK pathway is significantly down-regulated after mutant KRAS knockdown, these NSCLCs showed increased levels of phospho-STAT3 and phospho-EGFR, and variable changes in phospho-Akt. In addition, mutant KRAS knockdown sensitized the NSCLCs to p38 and EGFR inhibitors. Our findings suggest that targeting oncogenic KRAS by itself will not be sufficient treatment but may offer possibilities of combining anti-KRAS strategies with other targeted drugs. PMID:21306997

  6. Lrf suppresses prostate cancer through repression of a Sox9-dependent pathway for cellular senescence bypass and tumor invasion

    PubMed Central

    Zhang, Jiangwen; Chen, Zhenbang; Ala, Ugo; Webster, Kaitlyn A.; Tay, Yvonne; Gonzalez-Billalabeitia, Enrique; Egia, Ainara; Shaffer, David R.; Carver, Brett; Liu, Xue-Song; Taulli, Riccardo; Kuo, Winston Patrick; Nardella, Caterina; Signoretti, Sabina; Cordon-Cardo, Carlos; Gerald, William L.; Pandolfi, Pier Paolo

    2013-01-01

    Lrf has been previously described as a powerful proto-oncogene. Here we surprisingly demonstrate that Lrf plays a critical oncosuppressive role in the prostate. Prostate specific inactivation of Lrf leads to a dramatic acceleration of Pten-loss-driven prostate tumorigenesis through a bypass of Pten-loss-induced senescence (PICS). We show that LRF physically interacts with and functionally antagonizes SOX9 transcriptional activity on key target genes such as MIA, which is involved in tumor cell invasion, and H19, a long non-coding RNA precursor for an Rb-targeting miRNA. Inactivation of Lrf in vivo leads to Rb down-regulation, PICS bypass and invasive prostate cancer. Importantly, we found that LRF is genetically lost, as well as down-regulated at both the mRNA and protein levels in a subset of human advanced prostate cancers. Thus, we identify LRF as a context-dependent cancer gene that can act as an oncogene in some contexts but also displays oncosuppressive-like activity in Pten−/− tumors. PMID:23727861

  7. Tumor-suppressing roles of miR-214 and miR-218 in breast cancer

    PubMed Central

    LIU, BO; TIAN, YANFENG; LI, FANG; ZHAO, ZENGREN; JIANG, XIA; ZHAI, CONGJIE; HAN, XIAODONG; ZHANG, LIKE

    2016-01-01

    MicroRNAs (miRNAs) are small non-coding RNAs that are key post-transcriptional regulators of gene expression. MicroRNA-214 (miR-214) and microRNA-218 (miR-218) have shown the function of tumor suppressors in various types of human cancers. However, the biological functions of miR-214 and miR-218 in breast cancer have not been elucidated completely. The present study evaluated the expression and biological function of miR-214 and miR-218 in human breast cancer. Our results revealed that the expression of miR-214 and miR-218 were significantly decreased in breast cancer tissues compared with adjacent tissues. The aberrant expression of miR-214 and miR-218 were negatively associated with Ki-67, and the miR-218 expression was positively associated with progesterone receptor (PR) in breast cancer tissues. In vitro, the cell proliferation and migration were decreased, cell apoptosis was induced, and cell cycle was also disturbed in miR-214 or miR-218 overexpressed breast cancer cells. Our results demonstrated that miR-214 and miR-218 function as tumor suppressors in breast cancer, and may become biomarkers and potential therapeutic targets in breast cancer. PMID:27109339

  8. Salinomycin inhibits proliferation and induces apoptosis of human nasopharyngeal carcinoma cell in vitro and suppresses tumor growth in vivo

    SciTech Connect

    Wu, Danxin; Zhang, Yu; Huang, Jie; Fan, Zirong; Shi, Fengrong; Wang, Senming

    2014-01-10

    Highlight: •We first evaluated the effect of salinomycin on nasopharyngeal carcinoma (NPC). •Salinomycin could inhibit Wnt/β-catenin signaling and induce apoptosis in NPC. •So salinomycin may be a good potential candidate for the chemotherapy of NPC. -- Abstract: Salinomycin (Sal) is a polyether ionophore antibiotic that has recently been shown to induce cell death in various human cancer cells. However, whether salinomycin plays a functional role in nasopharyngeal carcinoma (NPC) has not been determined to date. The present study investigated the chemotherapeutic efficacy of salinomycin and its molecular mechanisms of action in NPC cells. Salinomycin efficiently inhibited proliferation and invasion of 3 NPC cell lines (CNE-1, CNE-2, and CNE-2/DDP) and activated a extensive apoptotic process that is accompanied by activation of caspase-3 and caspase-9, and decreased mitochondrial membrane potential. Meanwhile, the protein expression level of the Wnt coreceptor lipoprotein receptor related protein 6 (LRP6) and β-catenin was down-regulated, which showed that the Wnt/β-catenin signaling was involved in salinomycin-induced apoptosis of NPC cells. In a nude mouse NPC xenograft model, the anti-tumor effect of salinomycin was associated with the downregulation of β-catenin expression. The present study demonstrated that salinomycin can effectively inhibit proliferation and invasion, and induce apoptosis of NPC cells in vitro and inhibit tumor growth in vivo, probably via the inhibition of Wnt/β-catenin signaling, suggesting salinomycin as a potential candidate for the chemotherapy of NPC.

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

    PubMed

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

    2014-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  11. miR-136 suppresses tumor invasion and metastasis by targeting RASAL2 in triple-negative breast cancer

    PubMed Central

    YAN, MEISI; LI, XIAOBO; TONG, DANDAN; HAN, CHANGSONG; ZHAO, RAN; HE, YAN; JIN, XIAOMING

    2016-01-01

    MicroRNAs play an important role in the regulation of cancer migration, invasion and metastasis. Patients with triple-negative breast cancer (TNBC) have a high incidence of early relapse and metastasis; however, the molecular basis for metastasis and recurrence in these individuals remains largely unknown. Herein, we demonstrate that miR-136 is an anti-invasive microRNA in TNBC and suppresses mesenchymal invasion and metastasis. Our results demonstrated that miR-136 was downregulated in TNBC and negative correlated with the WHO grades. However, RASAL2 was identified as a functional target of miR-136, and was overexpressed in TNBC and correlates with pathological grades. Moreover, overexpression of RASAL2 in a breast cancer cell line rescued miR-136-mediated cell migration and invasion. In conclusion, these results indicate that the miR-136/RASAL2/MET axis act as a suppressor of TNBC metastasis. PMID:27108696

  12. Long Non-coding RNA TUSC7, a Target of miR-23b, Plays Tumor-Suppressing Roles in Human Gliomas

    PubMed Central

    Shang, Chao; Guo, Yan; Hong, Yang; Xue, Yi-xue

    2016-01-01

    Tumour suppressor candidate 7 (TUSC7) is a novel tumor suppressor gene generating long non-coding RNA (lncRNAs) in several types of human cancers. The expression and function of TUSC7 in human brain glioma has yet to be elucidated. In this study, TUSC7 was poorly expressed in tissues and cell lines of glioma, and the lower expression was correlated with glioma of the worse histological grade. Moreover, TUSC7 is a prognostic biomarker of glioma patients. Up-regulation of TUSC7 suppressed cellular proliferation and invasion of glioma cells, and accelerated cellular apoptosis. Bioinformatics analysis showed that TUSC7 specifically binds to miR-23b. MiR-23b was up-regulated in glioma and negatively correlated with the expression of TUSC7. The miR-23b expression was inhibited remarkably by the upregulation of TUSC7 and the reciprocal inhibition was determined between TUSC7 and miR-23b.RNA pull-down and luciferase reporter assays were used to validate the sequence-specific correlation between miR-23b and TUSC7. TUSC7 inhibited the proliferation, migration and invasion of glioma cells and promoted cellular apoptosis largely bypassing miR-23b. We conclude that the lncRNA TUSC7 acted as a tumor suppressor gene negatively regulated by miR-23b, suggesting a novel therapeutic strategy against gliomas. PMID:27766072

  13. MicroRNA-630 suppresses tumor metastasis through the TGF-β- miR-630-Slug signaling pathway and correlates inversely with poor prognosis in hepatocellular carcinoma

    PubMed Central

    Ding, Ze-yang; Liang, Hui-fang; Song, Jia; Tan, Xiao-long; Wu, Jing-jing; Li, Guang-zhen; Zeng, Zhuo; Zhang, Bi-xiang; Chen, Xiao-ping

    2016-01-01

    The epithelial-mesenchymal transition (EMT) is the key process that drives tumor metastasis. Accumulating evidence suggests that the deregulation of some microRNAs (miRNAs), is implicated in this process. Here, we highlight the function and molecular mechanism of miR-630 and its potential clinical application in hepatocellular carcinoma (HCC). First, we identified the clinical relevance of miR-630 expression in a screen of 97 HCC patient tissues. Patients with low miR-630 expression had higher recurrence rates and shorter overall survival than those with high miR-630 expression. Functional studies demonstrated the overexpression of miR-630 in HCC cells attenuated the EMT phenotype in vitro. Conversely, inhibition of miR-630 promoted EMT in HCC cells. Mechanistically, our data revealed that miR-630 suppressed EMT by targeting Slug. Knockdown of Slug expression reversed miR-630 inhibitor-mediated EMT progression. Furthermore, we found that the TGF-β-Erk/SP1 and JNK/c-Jun signaling pathways repressed miR-630 transcription through occupying transcription factor binding sites. Ectopic expression of miR-630 restored the TGF-β-activated EMT process. Taken together, these findings demonstrate, in HCC cells, miR-630 exerts its tumor-suppressor functions through the TGF-β-miR-630-Slug axis and provides a potential prognostic predictor for HCC patients. PMID:26993767

  14. BRAF V600E mutation correlates with suppressive tumor immune microenvironment and reduced disease-free survival in Langerhans cell histiocytosis.

    PubMed

    Zeng, Kaixuan; Wang, Zhe; Ohshima, Koichi; Liu, Yixiong; Zhang, Weichen; Wang, Lu; Fan, Linni; Li, Mingyang; Li, Xia; Wang, Yingmei; Yu, Zhou; Yan, Qingguo; Guo, Shuangping; Wei, Jie; Guo, Ying

    2016-07-01

    Langerhans cell histiocytosis (LCH) is a neoplasm of myeloid origin characterized by a clonal proliferation of CD1a(+)/CD207(+) dendritic cells. Recurrent BRAF V600E mutation has been reported in LCH. In the present report, we confirm the feasibility of the high-specificity monoclonal antibody VE1 for detecting BRAF V600E mutation in 36/97 (37.1%) retrospectively enrolled patients with LCH; concordant immunohistochemistry and Sanger sequencing results were seen in 94.8% of cases. We then assessed the tumor immune microenvironment status in LCH, and found that the GATA binding protein 3 (GATA3)(+)/T-bet(+) ratio could distinguish between clinical multi-system/single-system (SS) multifocal and SS unifocal LCH. Notably, we found that BRAF V600E mutation is significantly correlated with increased programmed cell death 1 ligand 1 (PDL1) expression and forkhead box protein 3 (FOXP3)(+) regulatory T cells (p < 0.001, 0.009, respectively). Moreover, Cox multivariate survival analysis showed that BRAF V600E mutation and PDL1 were independent prognostic factors of poor disease-free survival (DFS) in LCH (hazard ratio [HR] = 2.38, 95% confidence interval [CI] 1.02-5.56, p = 0.044; HR = 3.06, 95%CI 1.14-7.14, p = 0.025, respectively), and the superiority of PDL1 in sensitivity and specificity as biomarker for DFS in LCH was demonstrated by receiver operator characteristic (ROC) curves when compared with BRAF V600E and risk category. Collectively, this study identifies for the first time relationship between BRAF V600E mutation and a suppressive tumor immune microenvironment in LCH, resulting in disruption of host-tumor immune surveillance, which is DFS. Our findings may provide a rationale for combining immunotherapy and BRAF-targeted therapy for treating patients with BRAF V600E mutant LCH. PMID:27622040

  15. BRAF V600E mutation correlates with suppressive tumor immune microenvironment and reduced disease-free survival in Langerhans cell histiocytosis

    PubMed Central

    Zeng, Kaixuan; Wang, Zhe; Ohshima, Koichi; Liu, Yixiong; Zhang, Weichen; Wang, Lu; Fan, Linni; Li, Mingyang; Li, Xia; Wang, Yingmei; Yu, Zhou; Yan, Qingguo; Guo, Shuangping; Wei, Jie; Guo, Ying

    2016-01-01

    ABSTRACT Langerhans cell histiocytosis (LCH) is a neoplasm of myeloid origin characterized by a clonal proliferation of CD1a+/CD207+ dendritic cells. Recurrent BRAF V600E mutation has been reported in LCH. In the present report, we confirm the feasibility of the high-specificity monoclonal antibody VE1 for detecting BRAF V600E mutation in 36/97 (37.1%) retrospectively enrolled patients with LCH; concordant immunohistochemistry and Sanger sequencing results were seen in 94.8% of cases. We then assessed the tumor immune microenvironment status in LCH, and found that the GATA binding protein 3 (GATA3)+/T-bet+ ratio could distinguish between clinical multi-system/single-system (SS) multifocal and SS unifocal LCH. Notably, we found that BRAF V600E mutation is significantly correlated with increased programmed cell death 1 ligand 1 (PDL1) expression and forkhead box protein 3 (FOXP3)+ regulatory T cells (p < 0.001, 0.009, respectively). Moreover, Cox multivariate survival analysis showed that BRAF V600E mutation and PDL1 were independent prognostic factors of poor disease-free survival (DFS) in LCH (hazard ratio [HR] = 2.38, 95% confidence interval [CI] 1.02–5.56, p = 0.044; HR = 3.06, 95%CI 1.14–7.14, p = 0.025, respectively), and the superiority of PDL1 in sensitivity and specificity as biomarker for DFS in LCH was demonstrated by receiver operator characteristic (ROC) curves when compared with BRAF V600E and risk category. Collectively, this study identifies for the first time relationship between BRAF V600E mutation and a suppressive tumor immune microenvironment in LCH, resulting in disruption of host–tumor immune surveillance, which is DFS. Our findings may provide a rationale for combining immunotherapy and BRAF-targeted therapy for treating patients with BRAF V600E mutant LCH.

  16. BRAF V600E mutation correlates with suppressive tumor immune microenvironment and reduced disease-free survival in Langerhans cell histiocytosis

    PubMed Central

    Zeng, Kaixuan; Wang, Zhe; Ohshima, Koichi; Liu, Yixiong; Zhang, Weichen; Wang, Lu; Fan, Linni; Li, Mingyang; Li, Xia; Wang, Yingmei; Yu, Zhou; Yan, Qingguo; Guo, Shuangping; Wei, Jie; Guo, Ying

    2016-01-01

    ABSTRACT Langerhans cell histiocytosis (LCH) is a neoplasm of myeloid origin characterized by a clonal proliferation of CD1a+/CD207+ dendritic cells. Recurrent BRAF V600E mutation has been reported in LCH. In the present report, we confirm the feasibility of the high-specificity monoclonal antibody VE1 for detecting BRAF V600E mutation in 36/97 (37.1%) retrospectively enrolled patients with LCH; concordant immunohistochemistry and Sanger sequencing results were seen in 94.8% of cases. We then assessed the tumor immune microenvironment status in LCH, and found that the GATA binding protein 3 (GATA3)+/T-bet+ ratio could distinguish between clinical multi-system/single-system (SS) multifocal and SS unifocal LCH. Notably, we found that BRAF V600E mutation is significantly correlated with increased programmed cell death 1 ligand 1 (PDL1) expression and forkhead box protein 3 (FOXP3)+ regulatory T cells (p < 0.001, 0.009, respectively). Moreover, Cox multivariate survival analysis showed that BRAF V600E mutation and PDL1 were independent prognostic factors of poor disease-free survival (DFS) in LCH (hazard ratio [HR] = 2.38, 95% confidence interval [CI] 1.02–5.56, p = 0.044; HR = 3.06, 95%CI 1.14–7.14, p = 0.025, respectively), and the superiority of PDL1 in sensitivity and specificity as biomarker for DFS in LCH was demonstrated by receiver operator characteristic (ROC) curves when compared with BRAF V600E and risk category. Collectively, this study identifies for the first time relationship between BRAF V600E mutation and a suppressive tumor immune microenvironment in LCH, resulting in disruption of host–tumor immune surveillance, which is DFS. Our findings may provide a rationale for combining immunotherapy and BRAF-targeted therapy for treating patients with BRAF V600E mutant LCH. PMID:27622040

  17. Mango polyphenolics suppressed tumor growth in breast cancer xenografts in mice: role of the PI3K/AKT pathway and associated microRNAs.

    PubMed

    Banerjee, Nivedita; Kim, Hyemee; Krenek, Kimberly; Talcott, Stephen T; Mertens-Talcott, Susanne U

    2015-08-01

    The cytotoxic and anti-inflammatory properties of mango polyphenolics including gallic acid and gallotannins have been demonstrated in numerous types of cancers. We hypothesized that the phosphoinositide 3-kinase (PI3K)/AKT pathway and the expression of related miRNAs are involved in the chemotherapeutic activities of mango polyphenolics in a mouse xenograft model for breast cancer. The objectives of this research were to determine the tumor-cytotoxic activities of mango polyphenolics and the underlying molecular mechanisms involving posttranscriptional targets in BT474 breast cancer cells and xenografts in mice. In vitro findings showed cytotoxic effects of mango polyphenolics in BT474 breast cancer cells within a concentration range of 2.5 to 20 mg/L gallic acid equivalents. Mango polyphenolics suppressed the expression of PI3K, AKT, hypoxia inducible factor-1α, and vascular endothelial growth factor (VEGF) mRNA, and pAKT, AKT, pPI3K (p85), VEGF and nuclear factor-kappa B protein levels. The involvement of miR-126 was verified by using antagomiR for miR-126, where mango reversed the effect of the antagomiR of miR-126. In vivo, the intake of mango polyphenolics decreased the tumor volume by 73% in BT474 xenograft-bearing mice compared with the control group. In addition, mango reduced the expression of nuclear factor-kappa B (p65), pAKT, pPI3K, mammalian target of rapamycin, hypoxia inducible factor-1α, and VEGF protein in athymic nude mice. A screening for miRNA expression changes confirmed that mango polyphenolics modulated the expression of cancer-associated miRNAs including miR-126 in the xenografted tumors. In summary, mango polyphenolics have a chemotherapeutic potential against breast cancer that at least in part is mediated through the PI3K/AKT pathway and miR-126.

  18. Preparation of Oxaliplatin-Deoxycholic Acid Derivative Nanocomplexes and In Vivo Evaluation of Their Oral Absorption and Tumor Growth Suppression.

    PubMed

    Jeon, Ok-Cheol; Byun, Youngro; Park, Jin Woo

    2016-02-01

    To prepare orally available oxaliplatin (OXA), nanocomplexes were formed by ionic conjugation of OXA with the deoxycholic acid derivative, Nalpha-deoxycholy-L-lysyl-methylester (DCK), as an oral absorption enhancer. We characterized the DCK-conjugated OXA nanocomplexes by differential scanning calorimetry, particle size determination, and morphological analysis. To evaluate the effects of DCK on the intestinal permeability of OXA, we assessed the solubilities and partition coefficients of OXA and the OXA/DCK nanocomplex, and then conducted in vitro artificial intestinal membrane and Caco-2 cell permeability studies. Finally, bioavailability in rats and tumor growth inhibition in the squamous cell carcinoma (SCC7) model after oral administration of the OXA/DCK nanocomplex were investigated compared to pure OXA. Analysis of the ionic complex formation of OXA with DCK revealed that OXA existed in an amorphous form within the complex, resulting in for- mation of nanocomp;exes (35.05 +/- 4.48 nm in diameter). The solubility of OXA in water was approximately 7.07 mg/mL, whereas the water solubility of OXA/DCK was approximately 2.04 mg/mL and its partition coefficient was approximately 1.2-fold higher than that of OXA. The in vitro intestinal membrane permeability of OXA was significantly enhanced by complex formation with DCK. An in vivo pharmacokinetic study revealed that the Cm value of the OXA/DCK nanocomplex was 3.18-fold higher than that of OXA (32.22 +/- 10.24 ng/mL), and the resulting oral bioavailability of the OXA/DCK nanocomplex was 39.3-fold more than that of OXA. Furthermore, the oral administration of OXA/DCK significantly inhibited tumor growth in SCC7-bearing mice, and maximally inhibited tumor volume by 54% compared to the control. These findings demonstrate the therapeutic potential of the OXA/DCK nanocomplex as an oral anti-cancer therapy because it improves the oral absorption of OXA, which may improve patient compliance and expand the therapeutic

  19. BDNF is associated with SFRP1 expression in luminal and basal-like breast cancer cell lines and primary breast cancer tissues: a novel role in tumor suppression?

    PubMed

    Huth, Laura; Rose, Michael; Kloubert, Veronika; Winkens, Wiebke; Schlensog, Martin; Hartmann, Arndt; Knüchel, Ruth; Dahl, Edgar

    2014-01-01

    Secreted frizzled related protein 1 (SFRP1) functions as an important inhibitor of the Wnt pathway and is a known tumor suppressor gene, which is epigenetically silenced in a variety of tumors e.g. in breast cancer. However, it is still unclear how SFRP1 exactly affects the Wnt pathway. Our aim was to decipher SFRP1 involvement in biochemical signaling in dependency of different breast cancer subtypes and to identify novel SFRP1-regulated genes. We generated SFRP1 over-expressing in vitro breast cancer models, reflecting the two major subtypes by using basal-like BT20 and luminal-like HER2-positive SKBR3 cells. DNA microarray expression profiling of these models revealed that SFRP1 expression potentially modulates Bone morphogenetic protein- and Smoothened signaling (p<0.01), in addition to the known impact on Wnt signaling. Importantly, further statistical analysis revealed that in dependency of the cancer subtype model SFRP1 may affect the canonical and non-canonical Wnt pathway (p<0.01), respectively. While SFRP1 re-expression generally mediated distinct patterns of transcriptionally induced or repressed genes in BT20 and SKBR3 cells, brain derived neurotrophic factor (BDNF) was identified as a SFRP1 induced gene in both cell lines. Although BDNF has been postulated as a putative oncogene, the co-regulation with SFRP1 indicates a potential suppressive function in breast cancer. Indeed, a positive correlation between SFRP1 and BDNF protein expression could be shown (p<0.001) in primary breast cancer samples. Moreover, TCGA dataset based analysis clearly underscores that BDNF mRNA is down-regulated in primary breast cancer samples predicting a poor prognosis of these patients. In line, we functionally provide evidence that stable BDNF re-expression in basal-like BT20 breast cancer cells blocks tumor cell proliferation. Hence, our results suggest that BDNF might rather mediate suppressive than promoting function in human breast cancer whose mode of action should be

  20. Spica prunellae promotes cancer cell apoptosis, inhibits cell proliferation and tumor angiogenesis in a mouse model of colorectal cancer via suppression of stat3 pathway

    PubMed Central

    2013-01-01

    in vitro, without apparent toxicity. In addition, EESP significantly inhibited the phosphorylation of STAT3 in tumor tissues, indicating its suppressive action on the activation of STAT3 signaling. Consequently, the inhibitory effect of EESP on STAT3 activation resulted in an increase in the pro-apoptotic Bax/Bcl-2 ratio, decrease in the expression of the pro-proliferative Cyclin D1 and CDK4, as well as down-regulation of pro-angiogenic VEGF-A and VEGFR-2 expression. Finally, these molecular effects led to the induction of apoptosis, the inhibition of cell proliferation and tumor angiogenesis. Conclusions Spica Prunellae possesses a broad range of anti-cancer activities due to its ability to affect STAT3 pathway, suggesting that Spica Prunellae could be a novel potent therapeutic agent for the treatment of CRC. PMID:23800091

  1. Knockdown of malic enzyme 2 suppresses lung tumor growth, induces differentiation and impacts PI3K/AKT signaling.

    PubMed

    Ren, Jian-Guo; Seth, Pankaj; Clish, Clary B; Lorkiewicz, Pawel K; Higashi, Richard M; Lane, Andrew N; Fan, Teresa W-M; Sukhatme, Vikas P

    2014-01-01

    Mitochondrial malic enzyme 2 (ME2) catalyzes the oxidative decarboxylation of malate to yield CO2 and pyruvate, with concomitant reduction of dinucleotide cofactor NAD(+) or NADP(+). We find that ME2 is highly expressed in many solid tumors. In the A549 non-small cell lung cancer (NSCLC) cell line, ME2 depletion inhibits cell proliferation and induces cell death and differentiation, accompanied by increased reactive oxygen species (ROS) and NADP(+)/NADPH ratio, a drop in ATP, and increased sensitivity to cisplatin. ME2 knockdown impacts phosphoinositide-dependent protein kinase 1 (PDK1) and phosphatase and tensin homolog (PTEN) expression, leading to AKT inhibition. Depletion of ME2 leads to malate accumulation and pyruvate decrease, and exogenous cell permeable dimethyl-malate (DMM) mimics the ME2 knockdown phenotype. Both ME2 knockdown and DMM treatment reduce A549 cell growth in vivo. Collectively, our data suggest that ME2 is a potential target for cancer therapy. PMID:24957098

  2. Elastin-based protein polymer nanoparticles carrying drug at both corona and core suppress tumor growth in vivo

    PubMed Central

    Shi, Pu; Aluri, Suhaas; Lin, Yi-An; Shah, Mihir; Edman-Woolcott, Maria; Dhandhukia, Jugal; Cui, Honggang; MacKay, J. Andrew

    2013-01-01

    Numerous nanocarriers of small molecules depend on either non-specific physical encapsulation or direct covalent linkage. In contrast, this manuscript explores an alternative encapsulation strategy based on high-specificity avidity between a small molecule drug and its cognate protein target fused to the corona of protein polymer nanoparticles. With the new strategy, the drug associates tightly to the carrier and releases slowly, which may decrease toxicity and promote tumor accumulation via the enhanced permeability and retention effect. To test this hypothesis, the drug Rapamycin (Rapa) was selected for its potent anti-proliferative properties, which give it immunosuppressant and anti-tumor activity. Despite its potency, Rapa has low solubility, low oral bioavailability, and rapid systemic clearance, which make it an excellent candidate for nanoparticulate drug delivery. To explore this approach, genetically engineered diblock copolymers were constructed from elastin-like polypeptides (ELPs) that assemble small (<100 nm) nanoparticles. ELPs are protein polymers of the sequence (Val-Pro-Gly-Xaa-Gly)n, where the identity of Xaa and n determine their assembly properties. Initially, a screening assay for model drug encapsulation in ELP nanoparticles was developed, which showed that Rose Bengal and Rapa have high non-specific encapsulation in the core of ELP nanoparticles with a sequence where Xaa = Ile or Phe. While excellent at entrapping these drugs, their release was relatively fast (2.2 h half-life) compared to their intended mean residence time in the human body. Having determined that Rapa can be non-specifically entrapped in the core of ELP nanoparticles, FK506 binding protein 12 (FKBP), which is the cognate protein target of Rapa, was genetically fused to the surface of these nanoparticles (FSI) to enhance their avidity towards Rapa. The fusion of FKBP to these nanoparticles slowed the terminal half-life of drug release to 57.8 h. To determine if this class

  3. Inhibition of Autophagy Enhances Curcumin United light irradiation-induced Oxidative Stress and Tumor Growth Suppression in Human Melanoma Cells.

    PubMed

    Niu, Tianhui; Tian, Yan; Mei, Zhusong; Guo, Guangjin

    2016-01-01

    Malignant melanoma is the most aggressive form of skin carcinoma, which possesses fast propagating and highly invasive characteristics. Curcumin is a natural phenol compound that has various biological activities, such as anti-proliferative and apoptosis-accelerating impacts on tumor cells. Unfortunately, the therapeutical activities of Cur are severely hindered due to its extremely low bioavailability. In this study, a cooperative therapy of low concentration Cur combined with red united blue light irradiation was performed to inspect the synergistic effects on the apoptosis, proliferation and autophagy in human melanoma A375 cell. The results showed that red united blue light irradiation efficaciously synergized with Cur to trigger oxidative stress-mediated cell death, induce apoptosis and inhibit cell proliferation. Meanwhile, Western blotting revealed that combined disposure induced the formation of autophagosomes. Conversely, inhibition of the autophagy enhanced apoptosis, obstructed cell cycle arrest and induced reversible proliferation arrest to senescence. These findings suggest that Cur combined with red united blue light irradiation could generate photochemo-preventive effects via enhancing apoptosis and triggering autophagy, and pharmacological inhibition of autophagy convert reversible arrested cells to senescence, therefore reducing the possibility that damaged cells might escape programmed death. PMID:27502897

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

    PubMed

    Nakamura, K; Shinozuka, K; Kunitomo, M

    2000-12-01

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

  5. Indacaterol inhibits tumor cell invasiveness and MMP-9 expression by suppressing IKK/NF-κB activation.

    PubMed

    Lee, Su Ui; Ahn, Kyung-Seop; Sung, Min Hee; Park, Ji-Won; Ryu, Hyung Won; Lee, Hyun-Jun; Hong, Sung-Tae; Oh, Sei-Ryang

    2014-08-01

    The β2 adrenergic receptor (ADRB2) is a G protein-coupled transmembrane receptor expressed in the human respiratory tract and widely recognized as a pharmacological target for treatments of asthma and chronic obstructive pulmonary disorder (COPD). Although a number of ADRB2 agonists have been developed for use in asthma therapy, indacaterol is the only ultra-long-acting inhaled β2-agonist (LABA) approved by the FDA for relieving the symptoms in COPD patients. The precise molecular mechanism underlying the pharmacological effect of indacaterol, however, remains unclear. Here, we show that β-arrestin-2 mediates the internalization of ADRB2 following indacaterol treatment. Moreover, we demonstrate that indacaterol significantly inhibits tumor necrosis factor-α (TNF-α)-induced NF-κB activity by reducing levels of both phosphorylated-IKK and -IκBα, thereby decreasing NF-κB nuclear translocation and the expression of MMP-9, an NF-κB target gene. Subsequently, we show that indacaterol significantly inhibits TNF-α/NF-κB-induced cell invasiveness and migration in a human cancer cell line. In conclusion, we propose that indacaterol may inhibit NF-κB activity in a β-arrestin2-dependent manner, preventing further lung damage and improving lung function in COPD patients.

  6. Inhibition of Autophagy Enhances Curcumin United light irradiation-induced Oxidative Stress and Tumor Growth Suppression in Human Melanoma Cells

    PubMed Central

    Niu, Tianhui; Tian, Yan; Mei, Zhusong; Guo, Guangjin

    2016-01-01

    Malignant melanoma is the most aggressive form of skin carcinoma, which possesses fast propagating and highly invasive characteristics. Curcumin is a natural phenol compound that has various biological activities, such as anti-proliferative and apoptosis-accelerating impacts on tumor cells. Unfortunately, the therapeutical activities of Cur are severely hindered due to its extremely low bioavailability. In this study, a cooperative therapy of low concentration Cur combined with red united blue light irradiation was performed to inspect the synergistic effects on the apoptosis, proliferation and autophagy in human melanoma A375 cell. The results showed that red united blue light irradiation efficaciously synergized with Cur to trigger oxidative stress-mediated cell death, induce apoptosis and inhibit cell proliferation. Meanwhile, Western blotting revealed that combined disposure induced the formation of autophagosomes. Conversely, inhibition of the autophagy enhanced apoptosis, obstructed cell cycle arrest and induced reversible proliferation arrest to senescence. These findings suggest that Cur combined with red united blue light irradiation could generate photochemo-preventive effects via enhancing apoptosis and triggering autophagy, and pharmacological inhibition of autophagy convert reversible arrested cells to senescence, therefore reducing the possibility that damaged cells might escape programmed death. PMID:27502897

  7. Brg1 promotes both tumor-suppressive and oncogenic activities at distinct stages of pancreatic cancer formation

    PubMed Central

    Roy, Nilotpal; Malik, Shivani; Villanueva, Karina E.; Urano, Atsushi; Lu, Xinyuan; Von Figura, Guido; Seeley, E. Scott; Dawson, David W.; Collisson, Eric A.

    2015-01-01

    Pancreatic ductal adenocarcinoma (PDA) develops predominantly through pancreatic intraepithelial neoplasia (PanIN) and intraductal papillary mucinous neoplasm (IPMN) precursor lesions. Pancreatic acinar cells are reprogrammed to a “ductal-like” state during PanIN-PDA formation. Here, we demonstrate a parallel mechanism operative in mature duct cells during which functional cells undergo “ductal retrogression” to form IPMN-PDA. We further identify critical antagonistic roles for Brahma-related gene 1 (Brg1), a catalytic subunit of the SWI/SNF complexes, during IPMN-PDA development. In mature duct cells, Brg1 inhibits the dedifferentiation that precedes neoplastic transformation, thus attenuating tumor initiation. In contrast, Brg1 promotes tumorigenesis in full-blown PDA by supporting a mesenchymal-like transcriptional landscape. We further show that JQ1, a drug that is currently being tested in clinical trials for hematological malignancies, impairs PDA tumorigenesis by both mimicking some and inhibiting other Brg1-mediated functions. In summary, our study demonstrates the context-dependent roles of Brg1 and points to potential therapeutic treatment options based on epigenetic regulation in PDA. PMID:25792600

  8. The Numb/p53 circuitry couples replicative self-renewal and tumor suppression in mammary epithelial cells

    PubMed Central

    Tosoni, Daniela; Zecchini, Silvia; Coazzoli, Marco; Colaluca, Ivan; Mazzarol, Giovanni; Rubio, Alicia; Caccia, Michele; Villa, Emanuele; Zilian, Olav

    2015-01-01

    The cell fate determinant Numb orchestrates tissue morphogenesis and patterning in developmental systems. In the human mammary gland, Numb is a tumor suppressor and regulates p53 levels. However, whether this function is linked to its role in fate determination remains unclear. Here, by exploiting an ex vivo system, we show that at mitosis of purified mammary stem cells (SCs), Numb ensures the asymmetric outcome of self-renewing divisions by partitioning into the progeny that retains the SC identity, where it sustains high p53 activity. Numb also controls progenitor maturation. At this level, Numb loss associates with the epithelial-to-mesenchymal transition and results in differentiation defects and reacquisition of stemness features. The mammary gland of Numb-knockout mice displays an expansion of the SC compartment, associated with morphological alterations and tumorigenicity in orthotopic transplants. This is because of low p53 levels and can be inhibited by restoration of Numb levels or p53 activity, which results in successful SC-targeted treatment. PMID:26598619

  9. The Numb/p53 circuitry couples replicative self-renewal and tumor suppression in mammary epithelial cells.

    PubMed

    Tosoni, Daniela; Zecchini, Silvia; Coazzoli, Marco; Colaluca, Ivan; Mazzarol, Giovanni; Rubio, Alicia; Caccia, Michele; Villa, Emanuele; Zilian, Olav; Di Fiore, Pier Paolo; Pece, Salvatore

    2015-11-23

    The cell fate determinant Numb orchestrates tissue morphogenesis and patterning in developmental systems. In the human mammary gland, Numb is a tumor suppressor and regulates p53 levels. However, whether this function is linked to its role in fate determination remains unclear. Here, by exploiting an ex vivo system, we show that at mitosis of purified mammary stem cells (SCs), Numb ensures the asymmetric outcome of self-renewing divisions by partitioning into the progeny that retains the SC identity, where it sustains high p53 activity. Numb also controls progenitor maturation. At this level, Numb loss associates with the epithelial-to-mesenchymal transition and results in differentiation defects and reacquisition of stemness features. The mammary gland of Numb-knockout mice displays an expansion of the SC compartment, associated with morphological alterations and tumorigenicity in orthotopic transplants. This is because of low p53 levels and can be inhibited by restoration of Numb levels or p53 activity, which results in successful SC-targeted treatment. PMID:26598619

  10. miR-101 suppresses tumor proliferation and migration, and induces apoptosis by targeting EZH2 in esophageal cancer cells

    PubMed Central

    Lin, Chen; Huang, Fei; Li, Qiao-Zhi; Zhang, Ya-Jing

    2014-01-01

    Aim: To investigate the role of miR-101 in the regulation of tumor proliferation, invasion, apoptosis and to its target gene in human ESCC. Methods: The expression level of miR-101 in Eca109 cell line was determined by real-time polymerase chain reaction (PCR). After transfected with miR-101 mimics and inhibitor, proliferation, migration and apoptosis in ESCC cell line (Eca109) were detected by MTT, cell wound healing assay and flow cytometry, respectively. The expression of EZH2 in Eca109 cell was examined by immunohistochemical staining. Results: We found that miR-101 was significantly down-regulated in ESCC cell than in matched normal esophageal epithelium cell. The expression level of miR-101 was inversely correlated to EZH2 protein expression in ESCC cell. In Eca109 cells, over-expression of miR-101 significantly inhibited the migration and invasion of ESCC cells, and promotes cell apoptosis. Conclusions: These findings suggest that decreased expression of miR-101 might promote metastasis of human ESCC by inducing accumulation of EZH2 protein. PMID:25400732

  11. In vivo identification of tumor- suppressive PTEN ceRNAs in an oncogenic BRAF-induced mouse model of melanoma.

    PubMed

    Karreth, Florian A; Tay, Yvonne; Perna, Daniele; Ala, Ugo; Tan, Shen Mynn; Rust, Alistair G; DeNicola, Gina; Webster, Kaitlyn A; Weiss, Dror; Perez-Mancera, Pedro A; Krauthammer, Michael; Halaban, Ruth; Provero, Paolo; Adams, David J; Tuveson, David A; Pandolfi, Pier Paolo

    2011-10-14

    We recently proposed that competitive endogenous RNAs (ceRNAs) sequester microRNAs to regulate mRNA transcripts containing common microRNA recognition elements (MREs). However, the functional role of ceRNAs in cancer remains unknown. Loss of PTEN, a tumor suppressor regulated by ceRNA activity, frequently occurs in melanoma. Here, we report the discovery of significant enrichment of putative PTEN ceRNAs among genes whose loss accelerates tumorigenesis following Sleeping Beauty insertional mutagenesis in a mouse model of melanoma. We validated several putative PTEN ceRNAs and further characterized one, the ZEB2 transcript. We show that ZEB2 modulates PTEN protein levels in a microRNA-dependent, protein coding-independent manner. Attenuation of ZEB2 expression activates the PI3K/AKT pathway, enhances cell transformation, and commonly occurs in human melanomas and other cancers expressing low PTEN levels. Our study genetically identifies multiple putative microRNA decoys for PTEN, validates ZEB2 mRNA as a bona fide PTEN ceRNA, and demonstrates that abrogated ZEB2 expression cooperates with BRAF(V600E) to promote melanomagenesis. PMID:22000016

  12. Genistein suppresses proliferation and MET oncogene expression and induces EGR-1 tumor suppressor expression in immortalized human breast epithelial cells.

    PubMed

    Singletary, Keith; Ellington, Allison

    2006-01-01

    Higher soy food intake has been hypothesized to be a major factor explaining the decreased breast cancer risk in Asian countries, compared to those regions of the world consuming predominantly Western-style diets. Consumption of soy isoflavones, particularly genistein, has received considerable attention as the soy component largely responsible for the protective effects hypothesized to result from soy food consumption. However, the impact of adult consumption of soy foods on breast cancer risk in pre-menopausal and menopausal women is not consistent. There are recent epidemiological reports that consumption of soy foods can most effectively reduce breast cancer risk when consumed early in life during the pre-pubertal or adolescent periods. The aim of the present study was to evaluate the effects of physiologically-relevant levels of genistein (0.5 microM and 1 microM), concentrations achievable in the plasma following soy food consumption, on proliferation and expression of select genes in the human breast epithelial cell model. Treatment of the non-neoplastic, immortalized human breast epithelial MCF-10F cells with these low concentrations of genistein was associated with decreased cell proliferation, down-regulation of the protooncogene MET, up-regulation of the breast tumor suppressor gene EGR-1, and up-regulation of the immediate-early response genes FOS and JUN. In addition, genistein treatment was associated with a significant increase in Egr-1 binding to the transcription factor Sp1. Taken together, these genistein-induced changes in gene expressions provide insights into potential mechanisms by which this isoflavone may protect human breast cells against neoplastic transformation. PMID:16619504

  13. Tumor necrosis factor-α suppresses the protein fractional synthesis rate of the small intestine stimulated by glutamine in rats

    PubMed Central

    ZHOU, JIHONG; FAN, SHENGXIAN; CAO, YACHENG; ZHU, MINGFANG; HAN, YONG; CAO, XUEYING; LI, YOUSHENG

    2015-01-01

    The objective of this study was to examine whether and how TNF-α affects glutamine-enhanced protein synthesis and the expression of the amino acid transporter ASCT2 in the small intestine at the mRNA and protein levels. A total of 30 male Sprague-Dawley rats were randomly assigned into three groups, namely the total parenteral nutrition (TPN; control), glutamine-treated (Gln), and glutamine- and tumor necrosis factor-α (TNF-α)-treated (TNF-α) groups. At 30 min prior to examination, all rats were mainlined with [L-15N]leucine. The concentration of TNF-α in plasma and of glutamine in plasma and the small intestine was measured. The fractional synthesis rate (FSR) of protein and the mRNA and protein expression levels of ASCT2 in the small intestine were assessed. The level of TNF-α was highest in the TNF-α group and the glutamine concentration was elevated to a greater extent in the TNF-α group than in the other two groups. However, the FSR of protein in the small intestine was significantly higher in the Gln group compared with that in the TNF-α group. The mRNA and protein expression levels of ASCT2 in the experimental groups were significantly higher that those in the control group, but did not differ significantly between the Gln and TNF-α groups. These results indicate that TNF-α may attenuate glutamine-stimulated protein synthesis in the small intestine in the early stage of sepsis in rats. The mechanism may be that TNF-α inhibits the function of the glutamine transporter in the uptake the glutamine into target cells for protein synthesis. This inhibition may occur at or following protein translation. PMID:25574232

  14. Serotonin 5-hydroxytryptamine(2A) receptor activation suppresses tumor necrosis factor-alpha-induced inflammation with extraordinary potency.

    PubMed

    Yu, Bangning; Becnel, Jaime; Zerfaoui, Mourad; Rohatgi, Rasika; Boulares, A Hamid; Nichols, Charles D

    2008-11-01

    The G protein-coupled serotonin 5-hydroxytryptamine (5-HT)(2A) receptor is primarily recognized for its role in brain neurotransmission, where it mediates a wide variety of functions, including certain aspects of cognition. However, there is significant expression of this receptor in peripheral tissues, where its importance is largely unknown. We have now discovered that activation of 5-HT(2A) receptors in primary aortic smooth muscle cells provides a previously unknown and extremely potent inhibition of tumor necrosis factor (TNF)-alpha-mediated inflammation. 5-HT(2A) receptor stimulation with the agonist (R)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane [(R)-DOI] rapidly inhibits a variety of TNF-alpha-mediated proinflammatory markers, including intracellular adhesion molecule 1 (ICAM-1), vascular adhesion molecule 1 (VCAM-1), and interleukin (IL)-6 gene expression, nitric-oxide synthase activity, and nuclear translocation of nuclear factor kappaB, with IC(50) values of only 10 to 20 pM. It is significant that proinflammatory markers can also be inhibited by (R)-DOI hours after treatment with TNF-alpha. With the exception of a few natural toxins, no current drugs or small molecule therapeutics demonstrate a comparable potency for any physiological effect. TNF-alpha-mediated inflammatory pathways have been strongly implicated in a number of diseases, including atherosclerosis, rheumatoid arthritis, psoriasis, type II diabetes, depression, schizophrenia, and Alzheimer's disease. Our results indicate that activation of 5-HT(2A) receptors represents a novel, and extraordinarily potent, potential therapeutic avenue for the treatment of disorders involving TNF-alpha-mediated inflammation. Note that because (R)-DOI can significantly inhibit the effects of TNF-alpha many hours after the administration of TNF-alpha, potential therapies could be aimed not only at preventing inflammation but also treating inflammatory injury that has already occurred or is ongoing. PMID

  15. Extracellular vesicles modulate the glioblastoma microenvironment via a tumor suppression signaling network directed by miR-1.

    PubMed

    Bronisz, Agnieszka; Wang, Yan; Nowicki, Michal O; Peruzzi, Pierpaolo; Ansari, Khairul I; Ogawa, Daisuke; Balaj, Leonora; De Rienzo, Gianluca; Mineo, Marco; Nakano, Ichiro; Ostrowski, Michael C; Hochberg, Fred; Weissleder, Ralph; Lawler, Sean E; Chiocca, E Antonio; Godlewski, Jakub

    2014-02-01

    Extracellular vesicles have emerged as important mediators of intercellular communication in cancer, including by conveying tumor-promoting microRNAs between cells, but their regulation is poorly understood. In this study, we report the findings of a comparative microRNA profiling and functional analysis in human glioblastoma that identifies miR-1 as an orchestrator of extracellular vesicle function and glioblastoma growth and invasion. Ectopic expression of miR-1 in glioblastoma cells blocked in vivo growth, neovascularization, and invasiveness. These effects were associated with a role for miR-1 in intercellular communication in the microenvironment mediated by extracellular vesicles released by cancer stem-like glioblastoma cells. An extracellular vesicle-dependent phenotype defined by glioblastoma invasion, neurosphere growth, and endothelial tube formation was mitigated by loading miR-1 into glioblastoma-derived extracellular vesicles. Protein cargo in extracellular vesicles was characterized to learn how miR-1 directed extracellular vesicle function. The mRNA encoding Annexin A2 (ANXA2), one of the most abundant proteins in glioblastoma-derived extracellular vesicles, was found to be a direct target of miR-1 control. In addition, extracellular vesicle-derived miR-1 along with other ANXA2 extracellular vesicle networking partners targeted multiple pro-oncogenic signals in cells within the glioblastoma microenvironment. Together, our results showed how extracellular vesicle signaling promotes the malignant character of glioblastoma and how ectopic expression of miR-1 can mitigate this character, with possible implications for how to develop a unique miRNA-based therapy for glioblastoma management. PMID:24310399

  16. Enhancing mitochondrial respiration suppresses tumor promoter TPA-induced PKM2 expression and cell transformation in skin epidermal JB6 cells.

    PubMed

    Wittwer, Jennifer A; Robbins, Delira; Wang, Fei; Codarin, Sarah; Shen, Xinggui; Kevil, Christopher G; Huang, Ting-Ting; Van Remmen, Holly; Richardson, Arlan; Zhao, Yunfeng

    2011-09-01

    Differentiated cells primarily metabolize glucose for energy via the tricarboxylic acid cycle and oxidative phosphorylation, but cancer cells thrive on a different mechanism to produce energy, characterized as the Warburg effect, which describes the increased dependence on aerobic glycolysis. The M2 isoform of pyruvate kinase (PKM2), which is responsible for catalyzing the final step of aerobic glycolysis, is highly expressed in cancer cells and may contribute to the Warburg effect. However, whether PKM2 plays a contributing role during early cancer development is unclear. In our studies, we have made an attempt to elucidate the effects of varying mitochondrial respiration substrates on skin cell transformation and expression of PKM2. Tumorigenicity in murine skin epidermal JB6 P+ (promotable) cells was measured in a soft agar assay using 12-O-tetradecanoylphorbol-13-acetate (TPA) as a tumor promoter. We observed a significant reduction in cell transformation upon pretreatment with the mitochondrial respiration substrate succinate or malate/pyruvate. We observed that increased expression and activity of PKM2 in TPA-treated JB6 P+ cells and pretreatment with succinate or malate/pyruvate suppressed the effects. In addition, TPA treatment also induced PKM2 whereas PKM1 expression was suppressed in mouse skin epidermal tissues in vivo. In comparison with JB6 P+ cells, the nonpromotable JB6 P- cells showed no increase in PKM2 expression or activity upon TPA treatment. Knockdown of PKM2 using a siRNA approach significantly reduced skin cell transformation. Thus, our results suggest that PKM2 activation could be an early event and play a contributing role in skin tumorigenesis.

  17. Blocking the chaperone kinome pathway: Mechanistic insights into a novel dual inhibition approach for supra-additive suppression of malignant tumors

    SciTech Connect

    Grover, Abhinav; Shandilya, Ashutosh; Agrawal, Vibhuti; Pratik, Piyush; Bhasme, Divya; Bisaria, Virendra S.; Sundar, Durai

    2011-01-07

    Research highlights: {yields} Withaferin A and 17-DMAG synergistically inhibit the Hsp90-Cdc37 chaperone pair. {yields} Binding of WA to Cdc37 cleft suppresses its kinase binding activity. {yields} 17-DMAG binding to the association complex results in H-bonds with 60% clustering. {yields} The ligands' bound complex was found structurally and thermodynamically stable. -- Abstract: The chaperone Hsp90 is involved in regulating the stability and activation state of more than 200 'client' proteins and takes part in the cancer diseased states. The major clientele-protein kinases depend on Hsp90 for their proper folding and functioning. Cdc37, a kinase targeting co-chaperone of Hsp90, mediates the interactions between Hsp90 and protein kinases. Targeting of Cdc37 has the prospect of delivering predominantly kinase-selective molecular responses as compared to the current pharmacologic Hsp90 inhibitors. The present work reports a bio-computational study carried out with the aim of exploring the dual inhibition of Hsp90/Cdc37 chaperone/co-chaperone association complex by the naturally occurring drug candidates withaferin A and 17-DMAG along with their possible modes of action. Our molecular docking studies reveal that withaferin A in combination with 17-DMAG can act as potent chaperone system inhibitors. The structural and thermodynamic stability of the ligands' bound complex was also observed from molecular dynamics simulations in water. Our results suggest a novel tumor suppressive action mechanism of herbal ligands which can be looked forward for further clinical investigations for possible anticancer drug formulations.

  18. A knock-in mouse model reveals roles for nuclear Apc in cell proliferation, Wnt signal inhibition and tumor suppression

    PubMed Central

    Zeineldin, Maged; Cunningham, Jamie; McGuinness, William; Alltizer, Preston; Cowley, Brett; Blanchat, Bryan; Xu, Wenhao; Pinson, David; Neufeld, Kristi L.

    2011-01-01

    Mutation of the tumor suppressor adenomatous polyposis coli (APC) is considered an initiating step in the genesis of the vast majority of colorectal cancers. APC inhibits the Wnt signaling pathway by targeting proto-oncogene β-catenin for destruction by cytoplasmic proteasomes. In the presence of a Wnt signal, or in the absence of functional APC, β-catenin can serve as a transcription co-factor for genes required for cell proliferation such as cyclin D1 and c-Myc. In cultured cells, APC shuttles between the nucleus and cytoplasm, with nuclear APC implicated in inhibition of Wnt target gene expression. Taking a genetic approach to evaluate the functions of nuclear APC in the context of a whole organism, we generated a mouse model with mutations that inactivate the nuclear localization signals of Apc (ApcmNLS). ApcmNLS/mNLS mice are viable and fractionation of embryonic fibroblasts (MEFs) isolated from these mice revealed a significant reduction in nuclear Apc compared to Apc+/+ MEFs. The levels of Apc and β-catenin protein were not significantly altered in small intestinal epithelia from ApcmNLS/mNLS mice. Compared to Apc+/+ mice, ApcmNLS/mNLS mice displayed increased proliferation in epithelial cells from the jejunum, ileum, and colon. These same tissues from ApcmNLS/mNLS mice displayed more mRNA from three genes up-regulated in response to canonical Wnt signal, c-Myc, Axin2, and Cyclin D1, and less mRNA from Hath 1 which is down-regulated in response to Wnt. These observations suggest a role for nuclear Apc in inhibition of canonical Wnt signaling and control of epithelial proliferation in intestinal tissue. Furthermore, we found ApcMin/+ mice, which harbor a mutation that truncates Apc, have increased polyp size and multiplicity if they also carry the ApcmNLS allele. Taken together, this analysis of the novel ApcmNLS mouse model supports a role for nuclear Apc in control of Wnt target genes, intestinal epithelial cell proliferation and polyp formation. PMID

  19. Cell-to-cell distances between tumor-infiltrating inflammatory cells have the potential to distinguish functionally active from suppressed inflammatory cells.

    PubMed

    Nagl, S; Haas, M; Lahmer, G; Büttner-Herold, M; Grabenbauer, G G; Fietkau, R; Distel, L V

    2016-05-01

    Beyond their mere presence, the distribution pattern of inflammatory cells is of special interest. Our hypothesis was that random distribution may be a clear indicator of being non-functional as a consequence of lack of interaction. Here, we have assessed the implication of cell-to-cell distances among inflammatory cells in anal squamous cell carcinoma and a possible association with survival data. Thirty-eight patients suffering from anal carcinoma were studied using tissue microarrays, double staining immunohistochemistry, whole slide scanning and image analysis software. Therapy consisted of concurrent radiochemotherapy. Numbers of stromal and intraepithelial tumor-infiltrating inflammatory cells (TIC) and the distances between cells were quantified. Double-staining of FoxP3(+) cells with either CD8(+), CD1a(+) or CD20(+) cells was performed. Measured cell-to-cell distances were compared to computer simulated cell-to-cell distances leading to the assumption of non-randomly distributed and therefore functional immune cells. Intraepithelial CD1a(+) and CD20(+) cells were randomly distributed and therefore regarded as non-functional. In contrary, stromal CD20(+) cells had a non-random distribution pattern. A non-random distance between CD20(+) and FoxP3(+) cells was associated with a clearly unfavorable outcome. Measured distances between FoxP3(+) cells were distinctly shorter than expected and indicate a functional active state of the regulatory T cells (Treg). Analysis of cell-to-cell distances between TIC has the potential to distinguish between suppressed non-functional and functionally active inflammatory cells. We conclude that in this tumor model most of the CD1a(+) cells are non-functional as are the intraepithelial CD20(+) cells, while stromal CD20(+) cells and FoxP3(+) cells are functional cells. PMID:27467940

  20. High level of CFTR expression is associated with tumor aggression and knockdown of CFTR suppresses proliferation of ovarian cancer in vitro and in vivo.

    PubMed

    Xu, Jiao; Yong, Min; Li, Jia; Dong, Xiaojing; Yu, Tinghe; Fu, Xiao; Hu, Lina

    2015-05-01

    The cystic fibrosis transmembrane conductance regulator (CFTR) belongs to the ATP-binding cassette (ABC) transporter family, members of which are involved in various types of cancer. The relationship between CFTR and ovarian cancer remains to be elucidated. The aim of the present study was to investigate the expression of CFTR in human ovarian cancer tissues and its clinical significance in the progression of ovarian cancer. The role of CFTR in the malignant invasion, migration and proliferation of ovarian cancer in vitro and in vivo was also investigated. Immunohistochemical staining analysis was performed to detect the expression of CFTR in 83 cases of human epithelial ovarian cancer specimens. Moreover, SKOV3 and A2780 stable cell lines containing shRNA gene specific for CFTR were established. Cell proliferation and motility were observed and compared with CFTR-RNAi cells. Tumorigenicity of CFTR-RNAi cells was investigated by tumor xenograft experiments conducted subcutaneously in nude mice. The expresssion of CFTR in ovarian cancer was significantly higher than that in benign ovarian tumor and normal ovaries (P<0.05). In ovarian cancer, CFTR expression was significantly associated with advanced FIGO stage, poor histopathological grade and serum Ca-125 (P<0.05). Furthermore, we observed that CFTR staining was stronger in the serous type as compared to the other types (P<0.05). Compared with the negative control, decreased cell invasion, migration, proliferation, adhesion and colony formation were observed in CFTR-RNAi cells in vitro. In vivo, tumorigenic abilities of CFTR-RNAi cells were significantly repressed compared with that of the control groups. CFTR overexpression may play an important role in the development and progression of ovarian cancer. Additionally, the downregulation of CFTR suppresses aggressive malignant biological behaviors of ovarian cancer cells in vitro and in vivo. PMID:25738998

  1. Tumor-targeted delivery of a C-terminally truncated FADD (N-FADD) significantly suppresses the B16F10 melanoma via enhancing apoptosis

    PubMed Central

    Yang, Yun-Wen; Zhang, Chun-Mei; Huang, Xian-Jie; Zhang, Xiao-Xin; Zhang, Lin-Kai; Li, Jia-Huang; Hua, Zi-Chun

    2016-01-01

    Fas-associated protein with death domain (FADD), a pivotal adaptor protein transmitting apoptotic signals, is indispensable for the induction of extrinsic apoptosis. However, overexpression of FADD can form large, filamentous aggregates, termed death effector filaments (DEFs) by self-association and initiate apoptosis independent of receptor cross-linking. A mutant of FADD, which is truncated of the C-terminal tail (m-FADD, 182–205 aa) named N-FADD (m-FADD, 1–181 aa), can dramatically up-regulate the strength of FADD self-association and increase apoptosis. In this study, it was found that over-expression of FADD or N-FADD caused apoptosis of B16F10 cells in vitro, even more, N-FADD showed a more potent apoptotic effect than FADD. Meanwhile, Attenuated Salmonella Typhimurium strain VNP20009 was engineered to express FADD or N-FADD under the control of a hypoxia-induced NirB promoter and each named VNP-pN-FADD and VNP-pN-N-FADD. The results showed both VNP-pN-FADD and VNP-pN-N-FADD delayed tumor growth in B16F10 mice model, while VNP-pN-N-FADD suppressed melanoma growth more significantly than VNP-pN-FADD. Additionally, VNP-pN-FADD and VNP-pN-N-FADD induced apoptosis of tumor cells by activating caspase-dependent apoptotic pathway. Our results show that N-FADD is a more potent apoptotic inducer and VNP20009-mediated targeted expression of N-FADD provides a possible cancer gene therapeutic approach for the treatment of melanoma. PMID:27767039

  2. Inhibition of STAT3 and ErbB2 Suppresses Tumor Growth, Enhances Radiosensitivity, and Induces Mitochondria-Dependent Apoptosis in Glioma Cells

    SciTech Connect

    Gao Ling; Li Fengsheng; Dong Bo; Zhang Junquan; Rao Yalan; Cong Yue; Mao Bingzhi; Chen Xiaohua

    2010-07-15

    Purpose: Constitutively activated signal transducer and activator of transcription 3 (STAT3) and ErbB2 are involved in the pathogenesis of many tumors, including astrocytoma. Inactivation of these molecules is reported to result in radiosensitization. The purpose of this study was to investigate whether inhibition of STAT3, ErbB2, or both could enhance radiotherapy in the human glioma model (U251 and U87 cell lines). Methods and Materials: The RNAi plasmids targeting STAT3 or ErbB2 were constructed, and their downregulatory effects on target proteins were examined by immunoblotting. After combination treatment of RNAi with or without irradiation, the cell viability was determined using 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and clonogenic assays. The in vivo effect of combined treatment was determined using the U251 xenograft model. The apoptosis caused by the inhibition of STAT3 and ErbB2 was detected, and the mechanism involved in the apoptosis was investigated, including increases in caspase proteins, mitochondrial damage, and the expression of key modulating protein of different apoptosis pathways. Results: Transfection of U251 cells with STAT3 or ErbB2 siRNA plasmids specifically reduced their target gene expressions. Inhibition of STAT3 or ErbB2 greatly decreased glioma cell survival after 2, 4, or 6 Gy irradiation. Inhibition of STAT3 and ErbB2 also enhanced radiation-induced tumor growth inhibition in the U251 xenograft model. Furthermore, the suppression of either STAT3 or ErbB2 could induce U251 cell apoptosis, which was related primarily to the mitochondrial apoptotic pathway. Conclusions: These results indicated that simultaneous inhibition of STAT3 and ErbB2 expression can promote potent antitumor activity and radiosensitizing activity in human glioma.

  3. Functional properties and effect on growth suppression of human neuroblastoma tumors by isotype switch variants of monoclonal antiganglioside GD2 antibody 14.18.

    PubMed

    Mujoo, K; Kipps, T J; Yang, H M; Cheresh, D A; Wargalla, U; Sander, D J; Reisfeld, R A

    1989-06-01

    A complete family of IgG isotype switch variant hybridomas was generated from the anti-GD2 monoclonal IgG3-producing hybridoma, 14.18, with the aid of the fluorescence-activated cell sorter. The IgG1, IgG2b, and IgG2a monoclonal antibodies (Mabs) produced by respective isotype switch variant hybridomas 14G1, 14G2b, or 14G2a, have binding activities for the biochemically defined GD2 antigen and GD2-expressing neuroblastoma target cell lines identical to that of IgG3 Mabs produced by the 14.18 parent cell line. This permitted us to examine the relative in vitro and in vivo cytotoxic capacities of each of the anti-GD2 antibodies for GD2-expressing neuroblastoma cells independent of antibody binding affinity or specificity. Mabs produced by 14.18, 14G2a, or 14G2b, but not 14G1, can direct efficient complement-dependent cytotoxicity against neuroblastoma tumor cells in the presence of human complement. Mabs produced by the parent 14.18 or by 14G2a are more efficient in directing antibody-dependent cell-mediated cytotoxicity than Mabs produced by 14G2b, and Mabs of 14G1 are inactive. However, despite these noted in vitro differences, antibodies produced by each member of this switch variant family suppress the growth of human neuroblastoma tumor cells in BALB/c athymic nu/nu mice. These studies suggest that a mechanism(s) other than Fc-directed complement-dependent cytotoxicity or antibody-dependent cell-mediated cytotoxicity may account for the in vivo antitumor effects of these particular antibodies. PMID:2720646

  4. Tumor-suppressive p53 Signaling Empowers Metastatic Inhibitor KLF17-dependent Transcription to Overcome Tumorigenesis in Non-small Cell Lung Cancer.

    PubMed

    Ali, Amjad; Bhatti, Muhammad Zeeshan; Shah, Abdus Saboor; Duong, Hong-Quan; Alkreathy, Huda Mohammad; Mohammad, Shah Faisal; Khan, Rahmat Ali; Ahmad, Ayaz

    2015-08-28

    Metastasis, which is controlled by concerted action of multiple genes, is a complex process and is an important cause of cancer death. Krüppel-like factor 17 (KLF17) is a negative regulator of metastasis and epithelial-mesenchymal transition (EMT) during cancer progression. However, the underlying molecular mechanism and biological relevance of KLF17 in cancer cells are poorly understood. Here, we show that tumor suppressor protein p53 plays an integral role to induce KLF17 expression in non-small cell lung cancer (NSCLC). p53 is recruited to the KLF17 promoter and results in the formation of p53-DNA complex. p53 enhances binding of p300 and favors histone acetylation on the KLF17 promoter. Mechanistically, p53 physically interacts with KLF17 and thereby enhances the anti-metastatic function of KLF17. p53 empowers KLF17-mediated EMT genes transcription via enhancing physical association of KLF17 with target gene promoters. Nutlin-3 recruits KLF17 to EMT target gene promoters and results in the formation of KLF17-DNA complex via a p53-dependent pathway. p53 depletion abrogates DNA binding affinity of KLF17 to EMT target gene promoters. KLF17 is critical for p53 cellular activities in NSCLC. Importantly, KLF17 enhances p53 transcription to generate a novel positive feedback loop. KLF17 depletion accelerates lung cancer cell growth in response to chemotherapy. Mechanistically, we found that KLF17 increases the expression of tumor suppressor genes p53, p21, and pRB. Functionally, KLF17 required p53 to suppress cancer cell invasion and migration in NSCLC. In conclusion, our study highlights a novel insight into the anti-EMT effect of KLF17 via a p53-dependent pathway in NSCLC, and KLF17 may be a new therapeutic target in NSCLC with p53 status.

  5. Phosphatidylinositol glycan anchor biosynthesis, class X containing complex promotes cancer cell proliferation through suppression of EHD2 and ZIC1, putative tumor suppressors.

    PubMed

    Nakakido, Makoto; Tamura, Kenji; Chung, Suyoun; Ueda, Koji; Fujii, Risa; Kiyotani, Kazuma; Nakamura, Yusuke

    2016-09-01

    We identified phosphatidylinositol glycan anchor biosynthesis, class X (PIGX), which plays a critical role in the biosynthetic pathway of glycosylphosphatidylinositol (GPI)-anchor motif, to be upregulated highly and frequently in breast cancer cells. Knockdown of PIGX as well as reticulocalbin 1 (RCN1) and reticulocalbin 2 (RCN2), which we found to interact with PIGX and was indicated to regulate calcium-dependent activities, significantly suppressed the growth of breast cancer cells. We also identified PIGX to be a core protein in an RCN1/PIGX/RCN2 complex. Microarray analysis revealed that the expression of two putative tumor suppressor genes, Zic family member 1 (ZIC1) and EH-domain containing 2 (EHD2), were upregulated commonly in cells in which PIGX, RCN1, or RCN2 was knocked down, suggesting that this RCN1/PIGX/RCN2 complex could negatively regulate the expression of these two genes and thereby contribute to human breast carcinogenesis. Our results imply that PIGX may be a good candidate molecule for development of novel anticancer drugs for breast cancer. PMID:27572108

  6. Docosahexaenoic Acid Inhibits Tumor Promoter-Induced Urokinase-Type Plasminogen Activator Receptor by Suppressing PKCδ- and MAPKs-Mediated Pathways in ECV304 Human Endothelial Cells

    PubMed Central

    Lian, Sen; Xia, Yong; Nguyen, Thi Thinh; Ung, Trong Thuan; Yoon, Hyun Joong; Kim, Nam Ho; Kim, Kyung Keun; Jung, Young Do

    2016-01-01

    The overexpression of urokinase-type plasminogen activator receptor (uPAR) is associated with inflammation and virtually all human cancers. Despite the fact that docosahexaenoic acid (DHA) has been reported to possess anti-inflammatory and anti-tumor properties, the negative regulation of uPAR by DHA is still undefined. Here, we investigated the effect of DHA on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced uPAR expression and the underlying molecular mechanisms in ECV304 human endothelial cells. DHA concentration-dependently inhibited TPA-induced uPAR. Specific inhibitors and mutagenesis studies showed that PKCδ, JNK1/2, Erk1/2, NF-κB, and AP-1 were critical for TPA-induced uPAR expression. Application of DHA suppressed TPA-induced translocation of PKCδ, activation of the JNK1/2 and Erk1/2 signaling pathways, and subsequent AP-1 and NF-κB transactivation. In conclusion, these observations suggest a novel role for DHA in reducing uPAR expression and cell invasion by inhibition of PKCδ, JNK1/2, and Erk1/2, and the reduction of AP-1 and NF-κB activation in ECV304 human endothelial cells. PMID:27654969

  7. Phosphatidylinositol glycan anchor biosynthesis, class X containing complex promotes cancer cell proliferation through suppression of EHD2 and ZIC1, putative tumor suppressors

    PubMed Central

    Nakakido, Makoto; Tamura, Kenji; Chung, Suyoun; Ueda, Koji; Fujii, Risa; Kiyotani, Kazuma; Nakamura, Yusuke

    2016-01-01

    We identified phosphatidylinositol glycan anchor biosynthesis, class X (PIGX), which plays a critical role in the biosynthetic pathway of glycosylphosphatidylinositol (GPI)-anchor motif, to be upregulated highly and frequently in breast cancer cells. Knockdown of PIGX as well as reticulocalbin 1 (RCN1) and reticulocalbin 2 (RCN2), which we found to interact with PIGX and was indicated to regulate calcium-dependent activities, significantly suppressed the growth of breast cancer cells. We also identified PIGX to be a core protein in an RCN1/PIGX/RCN2 complex. Microarray analysis revealed that the expression of two putative tumor suppressor genes, Zic family member 1 (ZIC1) and EH-domain containing 2 (EHD2), were upregulated commonly in cells in which PIGX, RCN1, or RCN2 was knocked down, suggesting that this RCN1/PIGX/RCN2 complex could negatively regulate the expression of these two genes and thereby contribute to human breast carcinogenesis. Our results imply that PIGX may be a good candidate molecule for development of novel anticancer drugs for breast cancer. PMID:27572108

  8. Alpha-carotene inhibits metastasis in Lewis lung carcinoma in vitro, and suppresses lung metastasis and tumor growth in combination with taxol in tumor xenografted C57BL/6 mice.

    PubMed

    Liu, Yi-Zhen; Yang, Chih-Min; Chen, Jen-Yin; Liao, Junn-Wang; Hu, Miao-Lin

    2015-06-01

    This study aimed to investigate the anti-metastatic activity of α-carotene (AC) in Lewis lung carcinoma (LLC) and in combination with taxol in LLC-xenografted C57BL/6 mice. Cell culture studies reveal that AC significantly inhibited invasion, migration and activities of matrix metalloproteinase (MMP)-2, -9 and urokinase plasminogen activator but increased protein expression of tissue inhibitor of MMP (TIMP)-1, -2 and plasminogen activator inhibitor (PAI)-1. These effects of AC are similar to those of β-carotene at the same concentration (2.5 μM). AC (2.5 μM) also significantly inhibited integrin β1-mediated phosphorylation of focal adhesion kinase (FAK) which then decreased the phosphorylation of MAPK family. Findings from the animal model reveal that AC treatment (5m g/kg) alone significantly decreased lung metastasis without affecting primary tumor growth, whereas taxol treatment (6 mg/kg) alone exhibited significant inhibition on both actions, as compared to tumor control group. AC treatment alone significantly decreased protein expression of integrin β1 but increased protein expression of TIMP-1 and PAI-1 without affecting protein expression of TIMP-2 and phosphorylation of FAK in lung tissues, whereas taxol treatment alone significantly increased protein expression of TIMP-1, PAI-1 and TIMP-2 but decreased protein expression of integrin β1 and phosphorylation of FAK. The combined treatment produced stronger actions on lung metastasis and lung tissues protein expression of TIMP-1, TIMP-2 and PAI-1. Overall, we demonstrate that AC effectively inhibits LLC metastasis and suppresses lung metastasis in combination with taxol in LLC-bearing mice, suggesting that AC could be used as an anti-metastatic agent or as an adjuvant for anti-cancer drugs.

  9. Regulation of the collagen cross-linking enzymes LOXL2 and PLOD2 by tumor-suppressive microRNA-26a/b in renal cell carcinoma.

    PubMed

    Kurozumi, Akira; Kato, Mayuko; Goto, Yusuke; Matsushita, Ryosuke; Nishikawa, Rika; Okato, Atsushi; Fukumoto, Ichiro; Ichikawa, Tomohiko; Seki, Naohiko

    2016-05-01

    Our recent studies of microRNA (miRNA) expression signatures in human cancers revealed that microRNA-26a (miRNA-26a) and microRNA-26b (miRNA-26b) were significantly reduced in cancer tissues. To date, few reports have provided functional analyses of miR-26a or miR-26b in renal cell carcinoma (RCC). The aim of the present study was to investigate the functional significance of miR-26a and miR-26b in RCC and to identify novel miR-26a/b-mediated cancer pathways and target genes involved in RCC oncogenesis and metastasis. Downregulation of miR-26a or miR-26b was confirmed in RCC clinical specimens. Restoration of miR-26a or miR-26b in RCC cell lines (786-O and A498) revealed that these miRNAs significantly inhibited cancer cell migration and invasion. Our in silico analysis and luciferase reporter assays showed that lysyl oxidase-like 2 (LOXL2) and procollagen-lysine, 2-oxoglutarate 5-dioxygenase 2 (PLOD2) were directly regulated by these miRNAs. Moreover, downregulating the PLOD2 gene significantly inhibited cell migration and invasion in RCC cells. Thus, our data showed that two genes promoting metastasis, LOXL2 and PLOD2, were epigenetically regulated by tumor-suppressive microRNAs, miR-26a and miR-26b, providing important insights into the molecular mechanisms of RCC metastasis.

  10. Regulation of the collagen cross-linking enzymes LOXL2 and PLOD2 by tumor-suppressive microRNA-26a/b in renal cell carcinoma

    PubMed Central

    KUROZUMI, AKIRA; KATO, MAYUKO; GOTO, YUSUKE; MATSUSHITA, RYOSUKE; NISHIKAWA, RIKA; OKATO, ATSUSHI; FUKUMOTO, ICHIRO; ICHIKAWA, TOMOHIKO; SEKI, NAOHIKO

    2016-01-01

    Our recent studies of microRNA (miRNA) expression signatures in human cancers revealed that microRNA-26a (miRNA-26a) and microRNA-26b (miRNA-26b) were significantly reduced in cancer tissues. To date, few reports have provided functional analyses of miR-26a or miR-26b in renal cell carcinoma (RCC). The aim of the present study was to investigate the functional significance of miR-26a and miR-26b in RCC and to identify novel miR-26a/b-mediated cancer pathways and target genes involved in RCC oncogenesis and metastasis. Downregulation of miR-26a or miR-26b was confirmed in RCC clinical specimens. Restoration of miR-26a or miR-26b in RCC cell lines (786-O and A498) revealed that these miRNAs significantly inhibited cancer cell migration and invasion. Our in silico analysis and luciferase reporter assays showed that lysyl oxidase-like 2 (LOXL2) and procollagen-lysine, 2-oxoglutarate 5-dioxygenase 2 (PLOD2) were directly regulated by these miRNAs. Moreover, downregulating the PLOD2 gene significantly inhibited cell migration and invasion in RCC cells. Thus, our data showed that two genes promoting metastasis, LOXL2 and PLOD2, were epigenetically regulated by tumor-suppressive microRNAs, miR-26a and miR-26b, providing important insights into the molecular mechanisms of RCC metastasis. PMID:26983694

  11. CD4+CD25+CD127low Regulatory T Cells Play Predominant Anti-Tumor Suppressive Role in Hepatitis B Virus-Associated Hepatocellular Carcinoma

    PubMed Central

    Sharma, Shreya; Khosla, Ritu; David, Paul; Rastogi, Archana; Vyas, Ashish; Singh, Dileep; Bhardwaj, Ankit; Sahney, Amrish; Maiwall, Rakhi; Sarin, Shiv Kumar; Trehanpati, Nirupma

    2015-01-01

    , resulting in higher IL-10 and TGF-β secretion. Increased suppressive ability of Tregs in HBV-related HCC confers increased anti-tumor suppressive response than in non-HBV-HCC. Modulation of Tregs and PD1 may serve as useful therapeutic targets. PMID:25767469

  12. Overexpression of miR-509 Increases Apoptosis and Inhibits Invasion via Suppression of Tumor Necrosis Factor-α in Triple-Negative Breast Cancer Hs578T Cells.

    PubMed

    Zhang, Guoqiang; Liu, Zengyan; Han, Yong; Wang, Xiaohong; Yang, Zhenlin

    2016-01-01

    Triple-negative breast cancer (TNBC) is associated with high recurrence rates of metastasis and death. miR-509 has been reported to be a tumor suppressor in many cancers, but its effect in TNBC has not yet been identified. In this article, we explored the effects of miR-509 on the malignant phenotype of TNBC cells, including proliferation, apoptosis, migration, and invasion. We transiently transfected TNBC cells, Hs578T, with miR-509 mimic. Upon transfection, the expression of miR-509 was upregulated about 50-fold compared with cells transfected with scramble mimic. Overexpression of miR-509 inhibited cell proliferation, induced cell apoptosis, and suppressed cell invasion of Hs578T cells. Moreover, tumor necrosis factor-α (TNF-α) was involved in miR-509-mediated suppressive effects of TNBC cells, as being treated with TNF-α could partially abolish the suppressive effects of miR-509. Collectively, these data suggest that miR-509 could reverse the malignant phenotype of TNBC cells, probably by suppressing TNF-α. PMID:27656833

  13. Chimeric HBcAg virus-like particles presenting a HPV 16 E7 epitope significantly suppressed tumor progression through preventive or therapeutic immunization in a TC-1-grafted mouse model

    PubMed Central

    Chu, Xiaojie; Li, Yang; Long, Qiong; Xia, Ye; Yao, Yufeng; Sun, Wenjia; Huang, Weiwei; Yang, Xu; Liu, Cunbao; Ma, Yanbing

    2016-01-01

    Background Therapeutic human papillomavirus (HPV) vaccines are currently being developed. However, no therapeutic efficacy has been achieved in clinical trials for the treatment of cervical intraepithelial neoplasia or cancer. One of the important issues in increasing vaccine efficacy is determining the best way to enhance tumor antigen-specific cellular immune responses. This study aimed to explore the virus-like particles (VLPs) of hepatitis B core antigen (HBcAg) as potential therapeutic vaccine carriers and to assess its immunological characteristics. Methods Chimeric VLPs presenting a HPV 16 cytotoxic T lymphocytes epitope E749–57 (amino acid 49–57 of the E7 protein) were prepared using recombinant genes. C57BL/6 mice were immunized with VLPs and grafted with tumor cells TC-1 which is an E7-expressing tumorigenic cell line. The dynamic tumor growth was monitored and anti-tumor immune responses were investigated. Results Using a preventive strategy, immunization with VLPs resulted in nearly complete suppression of tumor growth. In treatment studies, VLP immunization significantly suppressed the tumor progression in mice carrying 2–3 mm tumors and in those bearing even larger tumors with diameters up to 8–9 mm. The VLP structure was shown to be important to induce vigorous antitumor immunity and effects. In immunized mice, enhanced E749–57-specific cellular immune responses were evidenced by increased interferon (IFN)-γ expression and decreased interleukin (IL)-4 expression in splenic lymphocytes, as well as an elevated number of effector cells expressing IFN-γ in response to the in vitro stimulation of the specific peptide E749–57. In addition, effective immune memory after VLP immunization was maintained for at least 16 weeks, preventing significant tumor growth after subsequent TC-1 challenge. Conclusion While VLPs were highly immunogenic in stimulating humoral immunity, our results strongly indicated that VLPs, such as HBcAg particles, might

  14. The Anti-Tumor Activity of Succinyl Macrolactin A Is Mediated through the β-Catenin Destruction Complex via the Suppression of Tankyrase and PI3K/Akt

    PubMed Central

    Kim, Seung Joo; Banskota, Suhrid; Shah, Sajita; Kim, Jung-Ae

    2015-01-01

    Accumulated gene mutations in cancer suggest that multi-targeted suppression of affected signaling networks is a promising strategy for cancer treatment. In the present study, we report that 7-O-succinyl macrolactin A (SMA) suppresses tumor growth by stabilizing the β-catenin destruction complex, which was achieved through inhibition of regulatory components associated with the complex. SMA significantly reduced the activities of PI3K/Akt, which corresponded with a decrease in GSK3β phosphorylation, an increase in β-catenin phosphorylation, and a reduction in nuclear β-catenin content in HT29 human colon cancer cells. At the same time, the activity of tankyrase, which inhibits the β-catenin destruction complex by destabilizing the axin level, was suppressed by SMA. Despite the low potency of SMA against tankyrase activity (IC50 of 50.1 μM and 15.5 μM for tankyrase 1 and 2, respectively) compared to XAV939 (IC50 of 11 nM for tankyrase 1), a selective and potent tankyrase inhibitor, SMA had strong inhibitory effects on β-catenin-dependent TCF/LEF1 transcriptional activity (IC50 of 39.8 nM), which were similar to that of XAV939 (IC50 of 28.1 nM). In addition to suppressing the colony forming ability of colon cancer cells in vitro, SMA significantly inhibited tumor growth in CT26 syngenic and HT29 xenograft mouse tumor models. Furthermore, treating mice with SMA in combination with 5-FU in a colon cancer xenograft model or with cisplatin in an A549 lung cancer xenograft model resulted in greater anti-tumor activity than did treatment with the drugs alone. In the xenograft tumor tissues, SMA dose-dependently inhibited nuclear β-catenin along with reductions in GSK3β phosphorylation and increases in axin levels. These results suggest that SMA is a possible candidate as an effective anti-cancer agent alone or in combination with cytotoxic chemotherapeutic drugs, such as 5-FU and cisplatin, and that the mode of action for SMA involves stabilization of the

  15. ADAP and SKAP55 deficiency suppresses PD-1 expression in CD8+ cytotoxic T lymphocytes for enhanced anti-tumor immunotherapy

    PubMed Central

    Li, Chunyang; Li, Weiyun; Xiao, Jun; Jiao, Shaozhuo; Teng, Fei; Xue, Shengjie; Zhang, Chi; Sheng, Chun; Leng, Qibin; Rudd, Christopher E; Wei, Bin; Wang, Hongyan

    2015-01-01

    PD-1 negatively regulates CD8+ cytotoxic T lymphocytes (CTL) cytotoxicity and anti-tumor immunity. However, it is not fully understood how PD-1 expression on CD8+ CTL is regulated during anti-tumor immunotherapy. In this study, we have identified that the ADAP-SKAP55 signaling module reduced CD8+ CTL cytotoxicity and enhanced PD-1 expression in a Fyn-, Ca2+-, and NFATc1-dependent manner. In DC vaccine-based tumor prevention and therapeutic models, knockout of SKAP55 or ADAP showed a heightened protection from tumor formation or metastases in mice and reduced PD-1 expression in CD8+ effector cells. Interestingly, CTLA-4 levels and the percentages of tumor infiltrating CD4+Foxp3+ Tregs remained unchanged. Furthermore, adoptive transfer of SKAP55-deficient or ADAP-deficient CD8+ CTLs significantly blocked tumor growth and increased anti-tumor immunity. Pretreatment of wild-type CD8+ CTLs with the NFATc1 inhibitor CsA could also downregulate PD-1 expression and enhance anti-tumor therapeutic efficacy. Together, we propose that targeting the unrecognized ADAP-SKAP55-NFATc1-PD-1 pathway might increase efficacy of anti-tumor immunotherapy. PMID:25851535

  16. Interferon-γ-induced activation of JAK1 and JAK2 suppresses tumor cell susceptibility to NK cells through upregulation of PD-L1 expression

    PubMed Central

    Bellucci, Roberto; Martin, Allison; Bommarito, Davide; Wang, Kathy; Hansen, Steen H; Freeman, Gordon J; Ritz, Jerome

    2015-01-01

    Inhibition of JAK1 or JAK2 in human tumor cells was previously shown to increase susceptibility of these cells to NK cell lysis. In the present study, we examined the cellular mechanisms that mediate this effect in hematopoietic tumor cell lines and primary tumor cells. Incubation of tumor cells with supernatant from activated NK cells or interferon-gamma (IFNγ)-induced activation of pSTAT1 and increased expression of PD-L1 without altering expression of other activating or inhibitory NK cell ligands. These functional effects were blocked by chemical JAK inhibition or shRNAs targeting JAK1, JAK2 or STAT1. Inhibition of IFNγ signaling also prevented the upregulation of PD-L1 and blocking PD-L1 resulted in increased tumor lysis by NK cells. These results show that NK cell activation and secretion of IFNγ results in activation of JAK1, JAK2 and STAT1 in tumor cells, resulting in rapid up-regulation of PD-L1 expression. Increased expression of PD-L1 results in increased resistance to NK cell lysis. Blockade of JAK pathway activation prevents increased PD-L1 expression resulting in increased susceptibility of tumor cells to NK cell activity. These observations suggest that JAK pathway inhibitors as well as PD-1 and PD-L1 antibodies may work synergistically with other immune therapies by preventing IFN-induced inhibition of NK cell-mediated tumor cell lysis. PMID:26155422

  17. Amphiregulin activates regulatory T lymphocytes and suppresses CD8+ T cell-mediated anti-tumor response in hepatocellular carcinoma cells.

    PubMed

    Yuan, Chun-Hui; Sun, Xiao-Ming; Zhu, Cheng-Liang; Liu, Shao-Ping; Wu, Long; Chen, Hao; Feng, Mao-Hui; Wu, Ke; Wang, Fu-Bing

    2015-10-13

    CD8+ T cell-mediated immune response plays an important role in inhibiting progression of hepatocellular carcinoma (HCC). For strategic immunotherapy, it is critical to understand why some of the tumor cells escape from this immune attack. In this study, we investigated how HCC cells alter endogenous anti-tumor immunity and their related signaling pathways. We found that HCC cells, both in vitro and in vivo, substantially secret and express amphiregulin (AR). AR in turn activates immunosuppressive function of intratumoral CD4+Foxp3+ regulatory T cells (Tregs), a major inhibitor of CD8+ T cells. Using either lentiviral siRNA, or AR neutralizing antibody, we blocked the expression and function of AR to test the specificity of AR mediated activation of Tregs, Biochemical and cell biology studies were followed and confirmed that blocking of AR inhibited Tregs activation. In addition, we found that AR can trigger the activation of rapamycin complex 1(mTORC1) signaling in Tregs. The mTORC1 inhibitor rapamycin treatment led to compromise Treg function and resulted in enhancing anti-tumor function of CD8+ T cells. Blocking AR/EGFR signaling in Tregs with Gefitinib also enhanced anti-tumor immunity and decreased tumor size in a mouse xenograft tumor model. Taken together, our study suggested a novel mechanism of functional interaction between HCC and Tregs for regulating anti-tumor function of CD8+ T cells. PMID:26451607

  18. Suppressing tumor growth of nasopharyngeal carcinoma by hTERTC27 polypeptide delivered through adeno-associated virus plus adenovirus vector cocktail

    PubMed Central

    Liu, Xiong; Li, Xiang-Ping; Peng, Ying; Ng, Samuel S.; Yao, Hong; Wang, Zi-Feng; Wang, Xiao-Mei; Kung, Hsiang-Fu; Lin, Marie C.M.

    2012-01-01

    Nasopharyngeal carcinoma (NPC) is a metastatic carcinoma that is highly prevalent in Southeast Asia. Our laboratory has previously demonstrated that the C-terminal 27-kDa polypeptide of human telomerase reverse transcriptase (hTERTC27) inhibits the growth and tumorigenicity of human glioblastoma and melanoma cells. In this study, we investigated the antitumor effect of hTERTC27 in human C666-1 NPC cells xenografted in a nude mouse model. A cocktail of vectors comprising recombinant adeno-associated virus (rAAV) and recombinant adenovirus (rAdv) that each carry hTERTC27 (rAAV-hTERTC27 and rAdv-hTERTC27; the cocktail was abbreviated to rAAV/rAdv-hTERTC27) was more effective than either rAAV-hTERTC27 or rAdv-hTERTC27 alone in inhibiting the growth of C666-1 NPC xenografts. Furthermore, we established three tumors on each mouse and injected rAAV/rAdv-hTERTC27 into one tumor per mouse. Although hTERTC27 expression could only be detected in the injected tumors, reduced tumor growth was observed in the injected tumor as well as the uninjected tumors, demonstrating that the vector cocktail could provoke an antitumor effect on distant, metastasized tumors. Further studies showed the observed antitumor effects included inducing necrosis and apoptosis and reducing microvessel density. Together, our data suggest that the rAAV/rAdv-hTERTC27 cocktail can potently inhibit NPC tumor growth in both local and metastasized tumors and should be further developed as a novel gene therapy strategy for NPC. PMID:23149313

  19. miR-27a-3p suppresses tumor metastasis and VM by down-regulating VE-cadherin expression and inhibiting EMT: an essential role for Twist-1 in HCC

    PubMed Central

    Zhao, Nan; Sun, Huizhi; Sun, Baocun; Zhu, Dongwang; Zhao, Xiulan; Wang, Yong; Gu, Qiang; Dong, Xueyi; Liu, Fang; Zhang, Yanhui; Li, Xiao

    2016-01-01

    Twist-1 and miRNAs have been reported to be associated with tumor metastasis and angiogenesis. However, the relationship between Twist-1 and miRNAs and the function of miRNAs remain largely undefined. We aimed to reveal the Twist-1-related miRNA expression profile and to determine whether Twist-1 functions in tumor metastasis and vasculogenic mimicry (VM) by regulating miRNA expression in hepatocellular carcinoma (HCC). Results showed that the expression of miR-27a-3p was consistently down-regulated in HCC cell lines and tissue samples displaying high expression of Twist-1. Both loss- and gain-of-function assays revealed suppressive effects of miR-27a-3p. Low miR-27a-3p expression was significantly associated with early metastasis in HCC. Subsequent investigations revealed that miR-27a-3p mediated the inhibition of epithelial–mesenchymal transition (EMT). Additional experiments showed that VE-cadherin is a direct target of miR-27a-3p and further demonstrated the critical role of miR-27a-3p in suppressing tumor metastasis and VM. Conclusions: Twist-1 up-regulation in HepG2 cells resulted in the differential expression of 18 miRNAs. Among them, miR-27a-3p deregulation contributed to VM and metastasis. The miR-27a-3p-mediated down-regulation of VE-cadherin and inhibition of EMT may be essential for Twist-1 to induce tumor metastasis and VM. Our findings highlight the importance of miR-27a-3p and suggest a promising new strategy for anti-HCC therapy. PMID:26980408

  20. Methylglyoxal suppresses human colon cancer cell lines and tumor growth in a mouse model by impairing glycolytic metabolism of cancer cells associated with down-regulation of c-Myc expression.

    PubMed

    He, Tiantian; Zhou, Huaibin; Li, Chunmei; Chen, Yuan; Chen, Xiaowan; Li, Chenli; Mao, Jiating; Lyu, Jianxin; Meng, Qing H

    2016-09-01

    Methylglyoxal (MG) is a highly reactive dicarbonyl compound exhibiting anti-tumor activity. The anti-tumor effects of MG have been demonstrated in some types of cancer, but its role in colon cancer and the mechanisms underlying this activity remain largely unknown. We investigated its role in human colon cancer and the underlying mechanism using human colon cancer cells and animal model. Viability, proliferation, and apoptosis were quantified in DLD-1 and SW480 colon cancer cells by using the Cell Counting Kit-8, plate colony formation assay, and flow cytometry, respectively. Cell migration and invasion were assessed by wound healing and transwell assays. Glucose consumption, lactate production, and intracellular ATP production also were assayed. The levels of c-Myc protein and mRNA were quantitated by western blot and qRT-PCR. The anti-tumor role of MG in vivo was investigated in a DLD-1 xenograft tumor model in nude mice. We demonstrated that MG inhibited viability, proliferation, migration, and invasion and induced apoptosis of DLD-1 and SW480 colon cancer cells. Treatment with MG reduced glucose consumption, lactate production, and ATP production and decreased c-Myc protein levels in these cells. Moreover, MG significantly suppressed tumor growth and c-Myc expression in vivo. Our findings suggest that MG plays an anti-tumor role in colon cancer. It inhibits cancer cell growth by altering the glycolytic pathway associated with downregulation of c-Myc protein. MG has therapeutic potential in colon cancer by interrupting cancer metabolism. PMID:27455418