196 research outputs found

    WIMP dark matter in gauge-mediated SUSY breaking models and its phenomenology

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    We propose an extended version of the gauge-mediated SUSY breaking models where extra SU(2)LSU(2)_L doublets and singlet field are introduced. These fields are assumed to be parity-odd under an additional matter parity. In this model, the lightest parity-odd particle among them would be dark matter in the Universe. In this paper, we discuss direct detection of the dark matter and the collider signatures of the modelComment: 17 pages, 4 figures, accepted for publication in Physics Letters

    Critical roles of DDX31-mutp53-EGFR axis in MIBC progression

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    The p53 and EGFR pathways are frequently altered in bladder cancers, yet their contributions to its progression remain elusive. Here we report that DEAD box polypeptide 31 (DDX31) plays a critical role in the multistep progression of muscle invasive bladder cancer (MIBC) through its sequential interactions with mutant p53 (mutp53) and EGFR. In early MIBC cells, nuclear DDX31 bound mutp53/SP1 and enhanced mutp53 transcriptional activation, leading to migration and invasion of MIBC. Cytoplasmic DDX31 also bound EGFR and phospho-nucleolin (p-NCL) in advanced MIBC, leading to EGFR-Akt signaling activation. High expression of both cytoplasmic DDX31 and p53 proteins correlated with poor prognosis in patients with MIBC, and blocking the DDX31-NCL interaction resulted in downregulation of EGFR-Akt signaling, eliciting an in vivo anti-tumor effect against bladder cancer. These findings reveal that DDX31 cooperates with mutp53 and EGFR to promote progression of MIBC, and inhibition of DDX31-NCL formation may lead to potential treatment strategies for advanced MIBC

    Stapled BIG3 helical peptide ERAP potentiates anti-tumour activity for breast cancer therapeutics

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    Estradiol (E2) and the oestrogen receptor-alpha (ERα) signalling pathway play pivotal roles in the proliferative activity of breast cancer cells. Recent findings show that the brefeldin A-inhibited guanine nucleotide-exchange protein 3-prohibitin 2 (BIG3-PHB2) complex plays a crucial role in E2/ERα signalling modulation in breast cancer cells. Moreover, specific inhibition of the BIG3-PHB2 interaction using the ERα activity-regulator synthetic peptide (ERAP: 165–177 amino acids), derived from α-helical BIG3 sequence, resulted in a significant anti-tumour effect. However, the duration of this effect was very short for viable clinical application. We developed the chemically modified ERAP using stapling methods (stapledERAP) to improve the duration of its antitumour effects. The stapledERAP specifically inhibited the BIG3-PHB2 interaction and exhibited long-lasting suppressive activity. Its intracellular localization without the membrane-permeable polyarginine sequence was possible via the formation of a stable α-helix structure by stapling. Tumour bearing-mice treated daily or weekly with stapledERAP effectively prevented the BIG3-PHB2 interaction, leading to complete regression of E2-dependent tumours in vivo. Most importantly, combination of stapledERAP with tamoxifen, fulvestrant, and everolimus caused synergistic inhibitory effects on growth of breast cancer cells. Our findings suggested that the stapled ERAP may be a promising anti-tumour drug to suppress luminal-type breast cancer growth

    エストロゲン受容体陽性乳がん細胞において、BIG3は複数のKaryopherin-αを介したPHB2のエストロゲン依存性核移行を阻害する

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    We recently reported that brefeldin A-inhibited guanine nucleotide-exchange protein 3 (BIG3) binds Prohibitin 2 (PHB2) in cytoplasm, thereby causing a loss of function of the PHB2 tumor suppressor in the nuclei of breast cancer cells. However, little is known regarding the mechanism by which BIG3 inhibits the nuclear translocation of PHB2 into breast cancer cells. Here, we report that BIG3 blocks the estrogen (E2)-dependent nuclear import of PHB2 via the karyopherin alpha (KPNA) family in breast cancer cells. We found that overexpressed PHB2 interacted with KPNA1, KPNA5, and KPNA6, thereby leading to the E2-dependent translocation of PHB2 into the nuclei of breast cancer cells. More importantly, knockdown of each endogenous KPNA by siRNA caused a significant inhibition of E2-dependent translocation of PHB2 in BIG3-depleted breast cancer cells, thereby enhancing activation of estrogen receptor alpha (ERα). These data indicated that BIG3 may block the KPNAs (KPNA1, KPNA5, and KPNA6) binding region(s) of PHB2, thereby leading to inhibition of KPNAs-mediated PHB2 nuclear translocation in the presence of E2 in breast cancer cells. Understanding this regulation of PHB2 nuclear import may provide therapeutic strategies for controlling E2/ERα signals in breast cancer cells

    Patterns of C-reactive protein trends during clozapine titration and the onset of clozapine-induced inflammation: a case series of weekly and daily C-reactive protein monitoring

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    BackgroundInternational guidelines for clozapine titration recommend measuring C-reactive protein (CRP) weekly for 4 weeks after clozapine initiation to prevent fatal inflammatory adverse events, including myocarditis. However, limited evidence exists regarding whether weekly CRP monitoring can prevent clozapine-induced inflammation.AimsWe examined the relationship between CRP trends and the development of clozapine-induced inflammation. We also explored the usefulness and limitations of CRP monitoring during clozapine titration.MethodThis study presents 17 and 4 cases of weekly and daily CRP monitoring during clozapine initiation, respectively.ResultsAmong 17 patients with weekly CRP measurements, 7 had fever. Elevated CRP levels were detected before the onset of fever in two of the seven patients. Of the five remaining patients, the CRP levels on a previous test had been low; however, the fever developed suddenly. Of the 10 patients with no fever under weekly CRP monitoring, three had elevated CRP levels >3.0 mg/dL. Refraining from increasing the clozapine dose may have prevented fever in these patients. Among four patients with daily CRP measurements, two became febrile. In both cases, CRP levels increased almost simultaneously with the onset of fever.ConclusionWeekly and daily CRP monitoring during clozapine titration is valuable for preventing clozapine-induced inflammation, assessing its severity, and guiding clozapine dose adjustments. Weekly CRP monitoring may not adequately predict clozapine-induced inflammation in some cases. Consequently, clinicians should be aware of the sudden onset of clozapine-induced inflammation, even if CRP levels are low. Daily CRP monitoring is better for detecting clozapine-induced inflammation

    Efficient Retrieval and Secure Distribution of Information about Nonwritten Cultural Materials

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    Our joint research is aimed at developing basic technology necessary for information about nonwritten cultural materials to be exchanged and shared among researchers or between researchers and non-experts, and at verifying the effectiveness of the technology by using a demonstration system targeting actual materials and researchers. We will offer a proposal for basic technology required to achieve these goals, and then develop a basic system for Tadami Townʼs mingu(folk implements) record cards. To improve the keyword search function of the Tadami Internet Eco-Museum, unseen relationships will be clarified by using the Web Ontology Language(OWL) for an ontology of nonwritten cultural materials. This will lead to the discovery of new relationships, and enable users to accurately retrieve information they really need. To design a user interface suitable to, for example, creating an ontology of nonwritten cultural materials and retrieving information about them, data will be made visually manageable by regarding each datum as swarm intelligence data that can self-organize, and controlling these data. The proposed management method can be applied to self-organizing methods according to the process of data management. We will propose two information retrieval methods that take the quality of the retrieval process into consideration: a method using ant colony optimization(ACO), a swarm intelligence algorithm; and a method using a so-called “recommender system.” To create a system in which personal and confidential information are protected and copyright mediation is autonomously conducted when information about nonwritten cultural materials is retrieved and distributed, we will also propose a digital watermarking method for the copyright management of bilevel line images that embeds information in images, not pixel values, using Bézier curves. Our other proposals include : swarm intelligence that regards access control as “language games,” and adapts to changing environments by using a concept of swarm and a concept of heredity ; a value exchange system designed to facilitate the documentation, data processing and distribution of nonwritten cultural materials that can reflect a variety of values by taking advantage of a characteristic of community currencies ― “value can be set independently” ; and a model that uses game theory to satisfy each user under particular conditions

    The antitumor activity of xanthohumol

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    Xanthohumol (XN), a simple prenylated chalcone, can be isolated from hops and has the potential to be a cancer chemopreventive agent against several human tumor cell lines. We previously identified valosin-containing protein (VCP) as a target of XN; VCP can also play crucial roles in cancer progression and prognosis. Therefore, we investigated the molecular mechanisms governing the contribution of VCP to the antitumor activity of XN. Several human tumor cell lines were treated with XN to investigate which human tumor cell lines are sensitive to XN. Several cell lines exhibited high sensitivity to XN both in vitro and in vivo. shRNA screening and bioinformatics analysis identified that the inhibition of the adenylate cyclase (AC) pathway synergistically facilitated apoptosis induced by VCP inhibition. These results suggest that there is crosstalk between the AC pathway and VCP function, and targeting both VCP and the AC pathway is a potential chemotherapeutic strategy for a subset of tumor cells

    トリプル ネガティブ ニュウガン ニオケル プロテアソーム カンレン インシ PAG1 ニヨル シンキ ゾウショク キコウ ノ カイメイ

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    Triple negative breast cancer (TNBC) is considered to be one of the most aggressive subtypes of all breast cancers. To identify novel potential therapeutic targets and clarify pathophysiological features for TNBC, we conducted Meta-gene profiling analysis based on gene-expression profiling of TNBC cases purified by lasermicrobeam microdissection, and found that proteasome-associated genes (PAGs) were commonly upregulated in various pathways including cell cycle regulation in TNBC. Depletion of PAGs with RNAi caused the upregulation of p27 and p21 proteins in MDA-MB-231 and HCC1937 cells, respectively, resulting in growth inhibition. Interestingly, immunocytochmical staining revealed that PAG1 was observed in the nucleoli and/or cytoplasm (n-PAG1 and c-PAG1) in TNBC cell line and clinical specimens. Immunohistochemical staining of 100 TNBCs showed that high level of n-PAG1 was significantly associated with poor disease free and overall survival of TNBC patients. These results indicate that n-PAG1 plays a critical role in nucleus during cell cycle progression and might be a novel prognostic indicator or an attractive molecular target of TNBC

    A-kinase anchoring protein BIG3 coordinates oestrogen signalling in breast cancer cells

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    Approximately 70% of breast cancer cells express oestrogen receptor alpha (ERα). Previous studies have shown that the Brefeldin A-inhibited guanine nucleotide-exchange protein 3–prohibitin 2 (BIG3-PHB2) complex has a crucial role in these cells. However, it remains unclear how BIG3 regulates the suppressive activity of PHB2. Here we demonstrate that BIG3 functions as an A-kinase anchoring protein that binds protein kinase A (PKA) and the α isoform of the catalytic subunit of protein phosphatase 1 (PP1Cα), thereby dephosphorylating and inactivating PHB2. E2-induced PKA-mediated phosphorylation of BIG3-S305 and -S1208 serves to enhance PP1Cα activity, resulting in E2/ERα signalling activation via PHB2 inactivation due to PHB2-S39 dephosphorylation. Furthermore, an analysis of independent cohorts of ERα-positive breast cancers patients reveal that both BIG3 overexpression and PHB2-S39 dephosphorylation are strongly associated with poor prognosis. This is the first demonstration of the mechanism of E2/ERα signalling activation via the BIG3–PKA–PP1Cα tri-complex in breast cancer cells
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