Lithocholic acid is an endogenous inhibitor of MDM4 and MDM2

PubMed Central

Vogel, Simon M.; Bauer, Matthias R.; Joerger, Andreas C.; Wilcken, Rainer; Brandt, Tobias; Veprintsev, Dmitry B.; Rutherford, Trevor J.; Fersht, Alan R.; Boeckler, Frank M.

2012-01-01

The proteins MDM2 and MDM4 are key negative regulators of the tumor suppressor protein p53, which are frequently upregulated in cancer cells. They inhibit the transactivation activity of p53 by binding separately or in concert to its transactivation domain. MDM2 is also a ubiquitin ligase that leads to the degradation of p53. Accordingly, MDM2 and MDM4 are important targets for drugs to inhibit their binding to p53. We found from in silico screening and confirmed by experiment that lithocholic acid (LCA) binds to the p53 binding sites of both MDM2 and MDM4 with a fivefold preference for MDM4. LCA is an endogenous steroidal bile acid, variously reported to have both carcinogenic and apoptotic activities. The comparison of LCA effects on apoptosis in HCT116 p53+/+ vs. p53-/- cells shows a predominantly p53-mediated induction of caspase-3/7. The dissociation constants are in the μM region, but only modest inhibition of binding of MDM2 and MDM4 is required to negate their upregulation because they have to compete with transcriptional coactivator p300 for binding to p53. Binding was weakened by structural changes in LCA, and so it may be a natural ligand of MDM2 and MDM4, raising the possibility that MDM proteins may be sensors for specific steroids. PMID:23035244

Foreign Language Attrition.

ERIC Educational Resources Information Center

de Bot, Kees; Weltens, Bert

1995-01-01

Reviews recent research on language maintenance and language loss, focusing on the loss of a second language in a first language environment, the linguistic aspects of loss, and relearning a "lost" language. An annotated bibliography discusses nine important works in the field. (43 references) (MDM)

Anatomy of Mdm2 and Mdm4 in evolution.

PubMed

Tan, Ban Xiong; Liew, Hoe Peng; Chua, Joy S; Ghadessy, Farid J; Tan, Yaw Sing; Lane, David P; Coffill, Cynthia R

2017-02-01

Mouse double minute (Mdm) genes span an evolutionary timeframe from the ancient eukaryotic placozoa Trichoplax adhaerens to Homo sapiens, implying a significant and possibly conserved cellular role throughout history. Maintenance of DNA integrity and response to DNA damage involve many key regulatory pathways, including precise control over the tumour suppressor protein p53. In most vertebrates, degradation of p53 through proteasomal targeting is primarily mediated by heterodimers of Mdm2 and the Mdm2-related protein Mdm4 (also known as MdmX). Both Mdm2 and Mdm4 have p53-binding regions, acidic domains, zinc fingers, and C-terminal RING domains that are conserved throughout evolution. Vertebrates typically have both Mdm2 and Mdm4 genes, while analyses of sequenced genomes of invertebrate species have identified single Mdm genes, suggesting that a duplication event occurred prior to emergence of jawless vertebrates about 550-440 million years ago. The functional relationship between Mdm and p53 in T. adhaerens, an organism that has existed for 1 billion years, implies that these two proteins have evolved together to maintain a conserved and regulated function. © The Author (2017). Published by Oxford University Press on behalf of Journal of Molecular Cell Biology, IBCB, SIBS, CAS.

Portal of medical data models: information infrastructure for medical research and healthcare.

PubMed

Dugas, Martin; Neuhaus, Philipp; Meidt, Alexandra; Doods, Justin; Storck, Michael; Bruland, Philipp; Varghese, Julian

2016-01-01

Information systems are a key success factor for medical research and healthcare. Currently, most of these systems apply heterogeneous and proprietary data models, which impede data exchange and integrated data analysis for scientific purposes. Due to the complexity of medical terminology, the overall number of medical data models is very high. At present, the vast majority of these models are not available to the scientific community. The objective of the Portal of Medical Data Models (MDM, https://medical-data-models.org) is to foster sharing of medical data models. MDM is a registered European information infrastructure. It provides a multilingual platform for exchange and discussion of data models in medicine, both for medical research and healthcare. The system is developed in collaboration with the University Library of Münster to ensure sustainability. A web front-end enables users to search, view, download and discuss data models. Eleven different export formats are available (ODM, PDF, CDA, CSV, MACRO-XML, REDCap, SQL, SPSS, ADL, R, XLSX). MDM contents were analysed with descriptive statistics. MDM contains 4387 current versions of data models (in total 10,963 versions). 2475 of these models belong to oncology trials. The most common keyword (n = 3826) is 'Clinical Trial'; most frequent diseases are breast cancer, leukemia, lung and colorectal neoplasms. Most common languages of data elements are English (n = 328,557) and German (n = 68,738). Semantic annotations (UMLS codes) are available for 108,412 data items, 2453 item groups and 35,361 code list items. Overall 335,087 UMLS codes are assigned with 21,847 unique codes. Few UMLS codes are used several thousand times, but there is a long tail of rarely used codes in the frequency distribution. Expected benefits of the MDM portal are improved and accelerated design of medical data models by sharing best practice, more standardised data models with semantic annotation and better information exchange between information systems, in particular Electronic Data Capture (EDC) and Electronic Health Records (EHR) systems. Contents of the MDM portal need to be further expanded to reach broad coverage of all relevant medical domains. Database URL: https://medical-data-models.org. © The Author(s) 2016. Published by Oxford University Press.

The Foray into the Neurosciences: Have We Learned Anything Useful Yet?

ERIC Educational Resources Information Center

Mollica, Anthony; Danesi, Marcel

1995-01-01

Reviews research on the neuroscientific perspective to second-language acquisition and teaching, focusing on the "critical period" of language acquisition, brain hemispheric mapping, universal grammar theory, the modal directionality principle, and the modal focusing principle. (contains 74 references) (MDM)

On Cats' Eyes, Flightless Birds, and "Home Signs."

ERIC Educational Resources Information Center

Stokoe, William C.

1995-01-01

Critiques the previous article by Torigoe and others (1995) and discusses research on indigenous gestural systems developed by people with deafness and shared with local hearing communities. Poses questions for further research in the field of indigenous gestural communication. (Seven references) (MDM)

A systems wide mass spectrometric based linear motif screen to identify dominant in-vivo interacting proteins for the ubiquitin ligase MDM2.

PubMed

Nicholson, Judith; Scherl, Alex; Way, Luke; Blackburn, Elizabeth A; Walkinshaw, Malcolm D; Ball, Kathryn L; Hupp, Ted R

2014-06-01

Linear motifs mediate protein-protein interactions (PPI) that allow expansion of a target protein interactome at a systems level. This study uses a proteomics approach and linear motif sub-stratifications to expand on PPIs of MDM2. MDM2 is a multi-functional protein with over one hundred known binding partners not stratified by hierarchy or function. A new linear motif based on a MDM2 interaction consensus is used to select novel MDM2 interactors based on Nutlin-3 responsiveness in a cell-based proteomics screen. MDM2 binds a subset of peptide motifs corresponding to real proteins with a range of allosteric responses to MDM2 ligands. We validate cyclophilin B as a novel protein with a consensus MDM2 binding motif that is stabilised by Nutlin-3 in vivo, thus identifying one of the few known interactors of MDM2 that is stabilised by Nutlin-3. These data invoke two modes of peptide binding at the MDM2 N-terminus that rely on a consensus core motif to control the equilibrium between MDM2 binding proteins. This approach stratifies MDM2 interacting proteins based on the linear motif feature and provides a new biomarker assay to define clinically relevant Nutlin-3 responsive MDM2 interactors. Copyright © 2014 Elsevier Inc. All rights reserved.

Modeling Lexical Borrowability.

ERIC Educational Resources Information Center

van Hout, Roeland; Muysken, Pieter

1994-01-01

Develops analytical techniques to determine "borrowability," the ease with which a lexical item or category of lexical items can be borrowed by one language from another. These techniques are then applied to Spanish borrowings in Bolivian Quechua on the basis of a set of bilingual texts. (29 references) (MDM)

Japanese Media in English.

ERIC Educational Resources Information Center

Tanaka, Sachiko Oda

1995-01-01

Describes the use of English in the media in Japan, focusing on the role and history of English-language newspapers, radio, and television programs, as well as the proliferation of English-language films shown in Japanese cinemas. Discusses the implications of English in the Japanese media. (20 references) (MDM)

Acquiring Nothing?: The Use of Zero Pronouns by Nonnative Speakers of Chinese and the Implications for the Acquisition of Nominal Reference.

ERIC Educational Resources Information Center

Polio, Charlene

1995-01-01

Examined how speakers of languages with zero pronouns (Japanese) and without them (English) use zero pronouns when acquiring a second language (L2) that has them (Mandarin Chinese). The findings show that L2 learners do not use zero pronouns as often as native speakers and that their use increases with proficiency. (51 references) (MDM)

Language and the Media.

ERIC Educational Resources Information Center

Bell, Allan

1995-01-01

Reviews recent research on the use of language in the mass media, focusing on the work of Teun van Dijk, A. Bell, Roger Fowler, and Norman Fairclough, as well as research on broadcast interviews, talk shows, and advertising. An annotated bibliography discusses 16 important works in the field. (58 references) (MDM)

A Linguistic Innovation of Women in Cairo.

ERIC Educational Resources Information Center

Haeri, Niloofar

1994-01-01

Investigated the sociolinguistic variable of apical palatalization in Cairene Arabic, focusing on the roles of gender and social class in the distribution of palatalization. As in a number of other speech communities, women in Cairo seem to have been the innovators of this sound change. (27 references) (MDM)

Human Oncoprotein MDM2 Up-regulates Expression of NF-κB2 Precursor p100 Conferring a Survival Advantage to Lung Cells

PubMed Central

Vaughan, Catherine; Mohanraj, Lathika; Singh, Shilpa; Dumur, Catherine I.; Ramamoorthy, Mahesh; Garrett, Carleton T.; Windle, Brad; Yeudall, W. Andrew; Deb, Sumitra

2011-01-01

The current model predicts that MDM2 is primarily overexpressed in cancers with wild-type (WT) p53 and contributes to oncogenesis by degrading p53. Following a correlated expression of MDM2 and NF-κB2 transcripts in human lung tumors, we have identified a novel transactivation function of MDM2. Here, we report that in human lung tumors, overexpression of MDM2 was found in approximately 30% of cases irrespective of their p53 status, and expression of MDM2 and NF-κB2 transcripts showed a highly significant statistical correlation in tumors with WT p53. We investigated the significance of this correlated expression in terms of mechanism and biological function. Increase in MDM2 expression from its own promoter in transgenic mice remarkably enhanced expression of NF-κB2 compared with its non-transgenic littermates. Knockdown or elimination of endogenous MDM2 expression in cultured non-transformed or lung tumor cells drastically reduced expression of NF-κB2 transcripts, suggesting a normal physiological role of MDM2 in regulating NF-κB2 transcription. MDM2 could up-regulate expression of NF-κB2 transcripts when its p53-interaction domain was blocked with Nutlin-3, indicating that the MDM2-p53 interaction is dispensable for up-regulation of NF-κB2 expression. Consistently, analysis of functional domains of MDM2 indicated that although the p53-interaction domain of MDM2 contributes to the up-regulation of the NFκB2 promoter, MDM2 does not require direct interactions with p53 for this function. Accordingly, MDM2 overexpression in non-transformed or lung cancer cells devoid of p53 also generated a significant increase in the expression of NF-κB2 transcript and its targets CXCL-1 and CXCL-10, whereas elimination of MDM2 expression had the opposite effects. MDM2-mediated increase in p100/NF-κB2 expression reduced cell death mediated by paclitaxel. Furthermore, knockdown of NF-κB2 expression retarded cell proliferation. Based on these data, we propose that MDM2-mediated NF-κB2 up-regulation is a combined effect of p53-dependent and independent mechanisms and that it confers a survival advantage to lung cancer cells. PMID:22701761

Monocyte-derived macrophages from Crohn's disease patients are impaired in the ability to control intracellular adherent-invasive Escherichia coli and exhibit disordered cytokine secretion profile.

PubMed

Vazeille, Emilie; Buisson, Anthony; Bringer, Marie-Agnès; Goutte, Marion; Ouchchane, Lemlih; Hugot, Jean-Pierre; de Vallée, Amélie; Barnich, Nicolas; Bommelaer, Gilles; Darfeuille-Michaud, Arlette

2015-05-01

Ileal lesions of Crohn's disease [CD] patients are colonised by adherent-invasive Escherichia coli [AIEC] able to survive in macrophage cell lines. We analysed the ability of monocyte-derived macrophages [MDM] from CD patients to control AIEC intracellular replication and the pro-inflammatory cytokine response of the infected-MDM. Peripheral blood MDM were obtained from 24 CD genotyped for NOD2 and ATG16L1 mutations, 5 ulcerative colitis [UC] patients and 12 healthy controls [HC]. The numbers of intracellular bacteria were determined using gentamicin assay. Cytokine secretion was quantified by ELISA assay. We observed that higher levels of bacteria were internalised within MDM from CD patients than MDM from HC or UC patients. MDM from CD patients were unable to restrict AIEC intracellular replication. Infection of MDM from CD patients with AIEC resulted in significantly increased secretion of IL-6 and tumour necrosis factor alpha [TNF α] than did infection with non-pathogenic E. coli. AIEC-infected MDM from CD patients exhibited a disordered cytokines secretion compared with MDM from UC patients and HC. AIEC-infected MDM from patients with quiescent CD released significantly higher amounts of IL-6 and TNF-alpha than those with active disease or those from HC. The level of secreted TNF-alpha was correlated to the number of intracellular AIEC in MDM from CD patients. Treatment of MDM with infliximab did not change the MDM behaviour. MDM from CD patients are unable to restrict intracellular AIEC replication, leading to disordered inflammatory response influenced by disease activity. Copyright © 2015 European Crohn’s and Colitis Organisation (ECCO). Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Sensitive and simultaneous surface plasmon resonance detection of free and p53-bound MDM2 proteins from human sarcomas.

PubMed

Wu, Ling; Tang, Hailin; Hu, Shengqiang; Xia, Yonghong; Lu, Zhixuan; Fan, Yujuan; Wang, Zixiao; Yi, Xinyao; Zhou, Feimeng; Wang, Jianxiu

2018-04-30

Murine double minute 2 (MDM2) is an oncoprotein mediating the degradation of the tumor suppressor p53 protein. The physiological levels of MDM2 protein are closely related to malignant transformation and tumor growth. In this work, the simultaneous and label-free determination of free and p53-bound MDM2 proteins from sarcoma tissue extracts was conducted using a dual-channel surface plasmon resonance (SPR) instrument. Free MDM2 protein was measured in one fluidic channel covered with the consensus double-stranded (ds)-DNA/p53 conjugate, while MDM2 bound to p53 was captured by the consensus ds-DNA immobilized onto the other channel. To achieve higher sensitivity and to confirm specificity, an MDM2-specific monoclonal antibody (2A10) was used to recognize both the free and p53-bound MDM2 proteins. The resultant method afforded a detection limit of 0.55 pM of MDM2. The amenability of the method to the analysis of free and p53-bound MDM2 proteins was demonstrated for normal and sarcoma tissue extracts from three patients. Our data reveal that both free and total MDM2 (free and bound forms combined) proteins from sarcoma tissue extracts are of much higher concentrations than those from normal tissue extracts and the p53-bound MDM2 protein only constitutes a small fraction of the total MDM2 concentration. In comparison with enzyme-linked immunosorbent assay (ELISA), the proposed method possesses higher sensitivity, is more cost-effective, and is capable of determining free and p53-bound MDM2 proteins in clinical samples.

MDM2 prevents spontaneous tubular epithelial cell death and acute kidney injury

PubMed Central

Thomasova, Dana; Ebrahim, Martrez; Fleckinger, Kristina; Li, Moying; Molnar, Jakob; Popper, Bastian; Liapis, Helen; Kotb, Ahmed M; Siegerist, Florian; Endlich, Nicole; Anders, Hans-Joachim

2016-01-01

Murine double minute-2 (MDM2) is an E3-ubiquitin ligase and the main negative regulator of tumor suppressor gene p53. MDM2 has also a non-redundant function as a modulator of NF-kB signaling. As such it promotes proliferation and inflammation. MDM2 is highly expressed in the unchallenged tubular epithelial cells and we hypothesized that MDM2 is necessary for their survival and homeostasis. MDM2 knockdown by siRNA or by genetic depletion resulted in demise of tubular cells in vitro. This phenotype was completely rescued by concomitant knockdown of p53, thus suggesting p53 dependency. In vivo experiments in the zebrafish model demonstrated that the tubulus cells of the larvae undergo cell death after the knockdown of mdm2. Doxycycline-induced deletion of MDM2 in tubular cell-specific MDM2-knockout mice Pax8rtTa-cre; MDM2f/f caused acute kidney injury with increased plasma creatinine and blood urea nitrogen and sharp decline of glomerular filtration rate. Histological analysis showed massive swelling of renal tubular cells and later their loss and extensive tubular dilation, markedly in proximal tubules. Ultrastructural changes of tubular epithelial cells included swelling of the cytoplasm and mitochondria with the loss of cristae and their transformation in the vacuoles. The pathological phenotype of the tubular cell-specific MDM2-knockout mouse model was completely rescued by co-deletion of p53. Tubular epithelium compensates only partially for the cell loss caused by MDM2 depletion by proliferation of surviving tubular cells, with incomplete MDM2 deletion, but rather mesenchymal healing occurs. We conclude that MDM2 is a non-redundant survival factor for proximal tubular cells by protecting them from spontaneous p53 overexpression-related cell death. PMID:27882940

MDM4 overexpression contributes to synoviocyte proliferation in patients with rheumatoid arthritis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Nanwei; Wang, Yuji, E-mail: yujiwang@sohu.com; State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai 200433

Research highlights: {yields} Elevated MDM4 mRNA and protein levels in FLS from patients with RA and OA. {yields} Strong MDM4 staining in synovial cells of inflammatory synovium. {yields} MDM4 knockdown increased p53 and p21 levels, and inhibited the proliferation of RA FLS. {yields} MDM4 overexpression increased p53 while decreased p21 levels, and promoted the growth of RA FLS. -- Abstract: Rheumatoid arthritis (RA) is a chronic autoimmune disease with features of inflammatory cell infiltration, synovial cell invasive proliferation, and ultimately, irreversible joint destruction. It has been reported that the p53 pathway is involved in RA pathogenesis. MDM4/MDMX is a majormore » negative regulator of p53. To determine whether MDM4 contributes to RA pathogenesis, MDM4 mRNA and protein expression were assessed in fibroblast-like synoviocytes (FLS) by real-time PCR, western blotting, and in synovial tissues by immunohistochemistry. Furthermore, MDM4 was knocked down and overexpressed by lentivirus-mediated expression, and the proliferative capacity of FLS was determined by MTS assay. We found that cultured FLS from RA and osteoarthritis (OA) patients exhibited higher levels of MDM4 mRNA and protein expression than those from trauma controls. MDM4 protein was highly expressed in the synovial lining and sublining cells from both types of arthritis. Finally, MDM4 knockdown inhibited the proliferation of RA FLS by enhancing functional p53 levels while MDM4 overexpression promoted the growth of RA FLS by inhibiting p53 effects. Taken together, our results suggest that the abundant expression of MDM4 in FLS may contribute to the hyperplasia phenotype of RA synovial tissues.« less

Discovery of Dual Inhibitors of MDM2 and XIAP for Cancer Treatment | Office of Cancer Genomics

Cancer.gov

MDM2 and XIAP are mutually regulated. Binding of MDM2 RING protein to the IRES region on XIAP mRNA results in MDM2 protein stabilization and enhanced XIAP translation. In this study, we developed a protein-RNA fluorescence polarization (FP) assay for high-throughput screening (HTS) of chemical libraries. Our FP-HTS identified eight inhibitors that blocked the MDM2 protein-XIAP RNA interaction, leading to MDM2 degradation.

A Fusion Protein of the p53 Transaction Domain and the p53-Binding Domain of the Oncoprotein MdmX as an Efficient System for High-Throughput Screening of MdmX Inhibitors.

PubMed

Chen, Rong; Zhou, Jingjing; Qin, Lingyun; Chen, Yao; Huang, Yongqi; Liu, Huili; Su, Zhengding

2017-06-27

In nearly half of cancers, the anticancer activity of p53 protein is often impaired by the overexpressed oncoprotein Mdm2 and its homologue, MdmX, demanding efficient therapeutics to disrupt the aberrant p53-MdmX/Mdm2 interactions to restore the p53 activity. While many potent Mdm2-specific inhibitors have already undergone clinical investigations, searching for MdmX-specific inhibitors has become very attractive, requiring a more efficient screening strategy for evaluating potential scaffolds or leads. In this work, considering that the intrinsic fluorescence residue Trp23 in the p53 transaction domain (p53p) plays an important role in determining the p53-MdmX/Mdm2 interactions, we constructed a fusion protein to utilize this intrinsic fluorescence signal to monitor high-throughput screening of a compound library. The fusion protein was composed of the p53p followed by the N-terminal domain of MdmX (N-MdmX) through a flexible amino acid linker, while the whole fusion protein contained a sole intrinsic fluorescence probe. The fusion protein was then evaluated using fluorescence spectroscopy against model compounds. Our results revealed that the variation of the fluorescence signal was highly correlated with the concentration of the ligand within 65 μM. The fusion protein was further evaluated with respect to its feasibility for use in high-throughput screening using a model compound library, including controls. We found that the imidazo-indole scaffold was a bona fide scaffold for template-based design of MdmX inhibitors. Thus, the p53p-N-MdmX fusion protein we designed provides a convenient and efficient tool for high-throughput screening of new MdmX inhibitors. The strategy described in this work should be applicable for other protein targets to accelerate drug discovery.

Phosphorylation of the Mdm2 oncoprotein by the c-Abl tyrosine kinase regulates p53 tumor suppression and the radiosensitivity of mice.

PubMed

Carr, Michael I; Roderick, Justine E; Zhang, Hong; Woda, Bruce A; Kelliher, Michelle A; Jones, Stephen N

2016-12-27

The p53 tumor suppressor acts as a guardian of the genome by preventing the propagation of DNA damage-induced breaks and mutations to subsequent generations of cells. We have previously shown that phosphorylation of the Mdm2 oncoprotein at Ser394 by the ATM kinase is required for robust p53 stabilization and activation in cells treated with ionizing radiation, and that loss of Mdm2 Ser394 phosphorylation leads to spontaneous tumorigenesis and radioresistance in Mdm2 S394A mice. Previous in vitro data indicate that the c-Abl kinase phosphorylates Mdm2 at the neighboring residue (Tyr393) in response to DNA damage to regulate p53-dependent apoptosis. In this present study, we have generated an Mdm2 mutant mouse (Mdm2 Y393F ) to determine whether c-Abl phosphorylation of Mdm2 regulates the p53-mediated DNA damage response or p53 tumor suppression in vivo. The Mdm2 Y393F mice develop accelerated spontaneous and oncogene-induced tumors, yet display no defects in p53 stabilization and activity following acute genotoxic stress. Although apoptosis is unaltered in these mice, they recover more rapidly from radiation-induced bone marrow ablation and are more resistant to whole-body radiation-induced lethality. These data reveal an in vivo role for c-Abl phosphorylation of Mdm2 in regulation of p53 tumor suppression and bone marrow failure. However, c-Abl phosphorylation of Mdm2 Tyr393 appears to play a lesser role in governing Mdm2-p53 signaling than ATM phosphorylation of Mdm2 Ser394. Furthermore, the effects of these phosphorylation events on p53 regulation are not additive, as Mdm2 Y393F/S394A mice and Mdm2 S394A mice display similar phenotypes.

Phosphorylation of the Mdm2 oncoprotein by the c-Abl tyrosine kinase regulates p53 tumor suppression and the radiosensitivity of mice

PubMed Central

Carr, Michael I.; Roderick, Justine E.; Zhang, Hong; Woda, Bruce A.; Kelliher, Michelle A.; Jones, Stephen N.

2016-01-01

The p53 tumor suppressor acts as a guardian of the genome by preventing the propagation of DNA damage-induced breaks and mutations to subsequent generations of cells. We have previously shown that phosphorylation of the Mdm2 oncoprotein at Ser394 by the ATM kinase is required for robust p53 stabilization and activation in cells treated with ionizing radiation, and that loss of Mdm2 Ser394 phosphorylation leads to spontaneous tumorigenesis and radioresistance in Mdm2S394A mice. Previous in vitro data indicate that the c-Abl kinase phosphorylates Mdm2 at the neighboring residue (Tyr393) in response to DNA damage to regulate p53-dependent apoptosis. In this present study, we have generated an Mdm2 mutant mouse (Mdm2Y393F) to determine whether c-Abl phosphorylation of Mdm2 regulates the p53-mediated DNA damage response or p53 tumor suppression in vivo. The Mdm2Y393F mice develop accelerated spontaneous and oncogene-induced tumors, yet display no defects in p53 stabilization and activity following acute genotoxic stress. Although apoptosis is unaltered in these mice, they recover more rapidly from radiation-induced bone marrow ablation and are more resistant to whole-body radiation-induced lethality. These data reveal an in vivo role for c-Abl phosphorylation of Mdm2 in regulation of p53 tumor suppression and bone marrow failure. However, c-Abl phosphorylation of Mdm2 Tyr393 appears to play a lesser role in governing Mdm2-p53 signaling than ATM phosphorylation of Mdm2 Ser394. Furthermore, the effects of these phosphorylation events on p53 regulation are not additive, as Mdm2Y393F/S394A mice and Mdm2S394A mice display similar phenotypes. PMID:27956626

Screening of medicinal plant phytochemicals as natural antagonists of p53-MDM2 interaction to reactivate p53 functioning.

PubMed

Riaz, Muhammad; Ashfaq, Usman A; Qasim, Muhammad; Yasmeen, Erum; Ul Qamar, Muhammad T; Anwar, Farooq

2017-10-01

In most types of cancer, overexpression of murine double minute 2 (MDM2) often leads to inactivation of p53. The crystal structure of MDM2, with a 109-residue amino-terminal domain, reveals that MDM2 has a core hydrophobic region to which p53 binds as an amphipathic α helix. The interface depends on the steric complementarity between MDM2 and the hydrophobic region of p53. Especially, on p53's triad, amino acids Phe19, Trp23 and Leu26 bind to the MDM2 core. Results from studies suggest that the structural motif of both p53 and MDM2 can be attributed to similarities in the amphipathic α helix. Thus, in the current investigation it is hypothesized that the similarity in the structural motif might be the cause of p53 inactivation by MDM2. Hence, molecular docking and phytochemical screening approaches are appraised to inhibit the hydrophobic cleft of MDM2 and to stop p53-MDM2 interaction, resulting in reactivation of p53 activity. For this purpose, a library of 2295 phytochemicals were screened against p53-MDM2 to find potential candidates. Of these, four phytochemicals including epigallocatechin gallate, alvaradoin M, alvaradoin E and nordihydroguaiaretic acid were found to be potential inhibitors of p53-MDM2 interaction. The screened phytochemicals, derived from natural extracts, may have negligible side effects and can be explored as potent antagonists of p53-MDM2 interactions, resulting in reactivation of the normal transcription of p53.

MDM2 phenotypic and genotypic profiling, respective to TP53 genetic status, in diffuse large B-cell lymphoma patients treated with rituximab-CHOP immunochemotherapy: a report from the International DLBCL Rituximab-CHOP Consortium Program

PubMed Central

Xu-Monette, Zijun Y.; Møller, Michael B.; Tzankov, Alexander; Montes-Moreno, Santiago; Hu, Wenwei; Manyam, Ganiraju C.; Kristensen, Louise; Fan, Lei; Visco, Carlo; Dybkær, Karen; Chiu, April; Tam, Wayne; Zu, Youli; Bhagat, Govind; Richards, Kristy L.; Hsi, Eric D.; Choi, William W. L.; van Krieken, J. Han; Huang, Qin; Huh, Jooryung; Ai, Weiyun; Ponzoni, Maurilio; Ferreri, Andrés J. M.; Wu, Lin; Zhao, Xiaoying; Bueso-Ramos, Carlos E.; Wang, Sa A.; Go, Ronald S.; Li, Yong; Winter, Jane N.; Medeiros, L. Jeffrey

2013-01-01

MDM2 is a key negative regulator of the tumor suppressor p53, however, the prognostic significance of MDM2 overexpression in diffuse large B-cell lymphoma (DLBCL) has not been defined convincingly. In a p53 genetically–defined large cohort of de novo DLBCL patients treated with rituximab, cyclophosphamide, hydroxydaunorubicin, vincristine, and prednisone (R-CHOP) chemotherapy, we assessed MDM2 and p53 expression by immunohistochemistry (n = 478), MDM2 gene amplification by fluorescence in situ hybridization (n = 364), and a single nucleotide polymorphism in the MDM2 promoter, SNP309, by SNP genotyping assay (n = 108). Our results show that MDM2 overexpression, unlike p53 overexpression, is not a significant prognostic factor in overall DLBCL. Both MDM2 and p53 overexpression do not predict for an adverse clinical outcome in patients with wild-type p53 but predicts for significantly poorer survival in patients with mutated p53. Variable p53 activities may ultimately determine the survival differences, as suggested by the gene expression profiling analysis. MDM2 amplification was observed in 3 of 364 (0.8%) patients with high MDM2 expression. The presence of SNP309 did not correlate with MDM2 expression and survival. This study indicates that evaluation of MDM2 and p53 expression correlating with TP53 genetic status is essential to assess their prognostic significance and is important for designing therapeutic strategies that target the MDM2-p53 interaction. PMID:23982177

Mdm4 loss in the intestinal epithelium leads to compartmentalized cell death but no tissue abnormalities

PubMed Central

Valentin-Vega, Yasmine A.; Box, Neil; Terzian, Tamara; Lozano, Guillermina

2014-01-01

Mdm4 is a critical inhibitor of the p53 tumor suppressor. Mdm4 null mice die early during embryogenesis due to increased p53 activity. In this study, we explore the role that Mdm4 plays in the intestinal epithelium by crossing mice carrying the Mdm4 floxed allele to mice with the Villin Cre transgene. Our data show that loss of Mdm4 (Mdm4intΔ) in this tissue resulted in viable animals with no obvious morphological abnormalities. However, these mutants displayed increased p53 levels and apoptosis exclusively in the proliferative compartment of the intestinal epithelium. This phenotype was completely rescued in a p53 null background. Notably, the observed compartmentalized apoptosis in proliferative intestinal epithelial cells was not due to restricted Mdm4 expression in this region. Thus, in this specific cellular context, p53 is negatively regulated by Mdm4 exclusively in highly proliferative cells. PMID:19371999

A Cognitive Study of English Loan Words in Japanese Discourse.

ERIC Educational Resources Information Center

Hayashi, Takuo; Hayashi, Reiko

1995-01-01

Discusses the use of English loanwords in Japanese discourse from a cognitive perspective and reveals how the world knowledge of English loanwords is applied to a text and constitutes an integral component of the discourse production process both within and beyond the sentence level. (40 references) (MDM)

Indigenous Language Education and Literacy: Introduction to the Theme Issue.

ERIC Educational Resources Information Center

McCarty, Teresa L.; Zepeda, Ofelia

1995-01-01

Discusses the 13 papers in this special issue on American Indian and Alaska Native language education and literacy, the object of which is to critically examine the relationship of pedagogical change to larger sociopolitical and cultural processes affecting native language, bilingual, and bicultural programs. (three references) (MDM)

Using Early Silent Film to Teach French: The Language of "Cinema Muet."

ERIC Educational Resources Information Center

Bloom, Michelle E.

1995-01-01

Discusses the use of early silent films in second-language classrooms, focusing on the experiences of one instructor in using early French silents in elementary and intermediate French courses. Sample lesson plans and information on the availability of French silents are also provided. (Contains 17 references.) (MDM)

The Role of Teachers' Guided Reflection in Effecting Positive Program Change.

ERIC Educational Resources Information Center

Vogt, Lynn Allington; Au, Kathryn H. P.

1995-01-01

Examines the evolution of teacher support and development in the Kamehameha Elementary Education Program (KEEP) and Rough Rock Community School collaboration. Ongoing teacher development featured regular classroom observation and feedback with mentors and peers and self-reflection through videotaping and journal writing. (two references) (MDM)

Autonomous Learning--The Danes Vote Yes!

ERIC Educational Resources Information Center

Chambers, Gary; Sugden, David

1994-01-01

Examines techniques used by 2 Danish teachers of English as a Second Language with 11- and 12-year-olds that illustrate the autonomous learning approach to second language instruction. The role of the teacher and learners, class activities, and student journals in Danish second language classrooms are discussed. (six references) (MDM)

Molecular dynamics simulations studies and free energy analysis on inhibitors of MDM2-p53 interaction.

PubMed

Niu, Rui-Juan; Zheng, Qing-Chuan; Zhang, Ji-Long; Zhang, Hong-Xing

2013-11-01

The oncoprotein MDM2 (murine double minute 2) negatively regulates the activity and stability of tumor suppressor p53. Inactivation of the MDM2-p53 interaction by potent inhibitors offers new possibilities for anticancer therapy. Molecular dynamics (MD) simulations were performed on three inhibitors-MDM2 complexes to investigate the stability and structural transitions. Simulations show that the backbone of MDM2 maintains stable during the whole time. However, slightly structural changes of inhibitors and MDM2 are observed. Furthermore, the molecular mechanics generalized Born surface area (MM-GBSA) approach was introduced to analyze the interactions between inhibitors and MDM2. The results show that binding of inhibitor pDIQ to MDM2 is significantly stronger than that of pMI and pDI to MDM2. The side chains of residues have more contribution than backbone of residues in energy decomposition. The structure-affinity analyses show that L54, I61, M62, Y67, Q72, H73 and V93 produce important interaction energy with inhibitors. The residue W/Y22' is also very important to the interaction between the inhibitors and MDM2. The three-dimensional structures at different times indicate that the mobility of Y100 influences on the binding of inhibitors to MDM2, and its change has important role in conformations of inhibitors and MDM2. Copyright © 2013 Elsevier Inc. All rights reserved.

Mutation at p53 serine 389 does not rescue the embryonic lethality in mdm2 or mdm4 null mice.

PubMed

Iwakuma, Tomoo; Parant, John M; Fasulo, Mark; Zwart, Edwin; Jacks, Tyler; de Vries, Annemieke; Lozano, Guillermina

2004-10-07

Mdm2 and its homolog Mdm4 inhibit the function of the tumor suppressor p53. Targeted disruption of either mdm2 or mdm4 genes in mice results in embryonic lethality that is completely rescued by concomitant deletion of p53, suggesting that deletion of negative regulators of p53 results in a constitutively active p53. Thus, these mouse models offer a unique in vivo system to assay the functional significance of different p53 modifications. Phosphorylation of serine 389 in murine p53 occurs specifically after ultraviolet-light-induced DNA damage, and phosphorylation of this site enhances p53 activity both in vitro and in vivo. Recently, mice with a serine to alanine substitution at serine 389 (p53S389A) in the endogenous p53 locus were generated. To examine the in vivo significance of serine 389 phosphorylation during embryogenesis, we crossed these mutant mice to mice lacking mdm2 or mdm4. The p53S389A allele did not alter the embryonic lethality of mdm2 or mdm4. Additional crosses to assay the effect of one p53S389A allele with a p53 null allele also did not rescue the lethal phenotypes. In conclusion, the phenotypes due to loss of mdm2 or mdm4 were not even partially rescued by p53S389A, suggesting that p53S389A is functionally wild type during embryogenesis.

Small-Molecule Inhibitors of the MDM2–p53 Protein–Protein Interaction (MDM2 Inhibitors) in Clinical Trials for Cancer Treatment

PubMed Central

2015-01-01

Design of small-molecule inhibitors (MDM2 inhibitors) to block the MDM2–p53 protein–protein interaction has been pursued as a new cancer therapeutic strategy. In recent years, potent, selective, and efficacious MDM2 inhibitors have been successfully obtained and seven such compounds have been advanced into early phase clinical trials for the treatment of human cancers. Here, we review the design, synthesis, properties, preclinical, and clinical studies of these clinical-stage MDM2 inhibitors. PMID:25396320

Preclinical efficacy of the MDM2 inhibitor RG7112 in MDM2 amplified and TP53 wild-type glioblastomas

PubMed Central

Verreault, Maite; Schmitt, Charlotte; Goldwirt, Lauriane; Pelton, Kristine; Haidar, Samer; Levasseur, Camille; Guehennec, Jeremy; Knoff, David; Labussiere, Marianne; Marie, Yannick; Ligon, Azra H.; Mokhtari, Karima; Hoang-Xuan, Khe; Sanson, Marc; Alexander, Brian M; Wen, Patrick Y.; Delattre, Jean-Yves; Ligon, Keith L.; Idbaih, Ahmed

2016-01-01

Rationale p53 pathway alterations are key molecular events in glioblastoma (GBM). MDM2 inhibitors increase expression and stability of p53 and are presumed to be most efficacious in patients with TP53 wild-type and MDM2-amplified cancers. However, this biomarker hypothesis has not been tested in patients or patient-derived models for GBM. Methods We performed a preclinical evaluation of RG7112 MDM2 inhibitor, across a panel of 36 patient-derived GBM cell lines (PDCLs), each genetically characterized according to their P53 pathway status. We then performed a pharmacokinetic (PK) profiling of RG7112 distribution in mice and evaluated the therapeutic activity of RG7112 in orthotopic and subcutaneous GBM models. Results MDM2-amplified PDCLs were 44 times more sensitive than TP53 mutated lines that showed complete resistance at therapeutically attainable concentrations (avg. IC50 of 0.52 μM vs 21.9 μM). MDM4 amplified PDCLs were highly sensitive but showed intermediate response (avg. IC50 of 1.2 μM), whereas response was heterogeneous in TP53 wild-type PDCLs with normal MDM2/4 levels (avg. IC50 of 7.7 μM). In MDM2-amplified lines, RG7112 restored p53 activity inducing robust p21 expression and apoptosis. PK profiling of RG7112-treated PDCL intracranial xenografts demonstrated that the compound significantly crosses the blood-brain and the blood-tumor barriers. Most importantly, treatment of MDM2-amplified/TP53 wild-type PDCL-derived model (subcutaneous and orthotopic) reduced tumor growth, was cytotoxic, and significantly increased survival. Conclusion These data strongly support development of MDM2 inhibitors for clinical testing in MDM2-amplified GBM patients. Moreover, significant efficacy in a subset of non-MDM2 amplified models suggests that additional markers of response to MDM2 inhibitors must be identified. PMID:26482041

Synergistic cooperation of MDM2 and E2F1 contributes to TAp73 transcriptional activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kasim, Vivi, E-mail: vivikasim78@gmail.com; Huang, Can; Zhang, Jing

2014-07-04

Highlights: • MDM2 is a novel positive regulator of TAp73 transcriptional activity. • MDM2 colocalizes together and physically interacts with E2F1. • Synergistic cooperation of MDM2 and E2F1 is crucial for TAp73 transcription. • MDM2 regulates TAp73 transcriptional activity in a p53-independent manner. - Abstract: TAp73, a structural homologue of p53, plays an important role in tumorigenesis. E2F1 had been reported as a transcriptional regulator of TAp73, however, the detailed mechanism remains to be elucidated. Here we reported that MDM2-silencing reduced the activities of the TAp73 promoters and the endogenous TAp73 expression level significantly; while MDM2 overexpression upregulated them. Wemore » further revealed that the regulation of TAp73 transcriptional activity occurs as a synergistic effect of MDM2 and E2F1, most probably through their physical interaction in the nuclei. Furthermore, we also suggested that MDM2 might be involved in DNA damage-induced TAp73 transcriptional activity. Finally, we elucidated that MDM2-silencing reduced the proliferation rate of colon carcinoma cells regardless of the p53 status. Our data show a synergistic effect of MDM2 and E2F1 on TAp73 transcriptional activity, suggesting a novel regulation pathway of TAp73.« less

Induction of MDM2-P2 Transcripts Correlates with Stabilized Wild-Type p53 in Betel- and Tobacco-Related Human Oral Cancer

PubMed Central

Ralhan, Ranju; Sandhya, Agarwal; Meera, Mathur; Bohdan, Wasylyk; Nootan, Shukla K.

2000-01-01

MDM2, a critical element of cellular homeostasis mechanisms, is involved in complex interactions with important cell-cycle and stress-response regulators including p53. The mdm2-P2 promoter is a transcriptional target of p53. The aim of this study was to determine the association between mdm2-P2 transcripts and the status of the p53 gene in betel- and tobacco-related oral squamous cell carcinomas (SCCs) to understand the mechanism of deregulation of MDM2 and p53 expression and their prognostic implications in oral tumorigenesis. Elevated levels of MDM2 proteins were observed in 11 of 25 (44%) oral hyperplastic lesions, nine of 15 (60%) dysplastic lesions, and 71 of 100 (71%) SCCs. The intriguing feature of the study was the identification and different subcellular localization of three isoforms of MDM2 (ie, 90 kd, 76 kd, and 57 kd) in oral SCCs and their correlation with p53 overexpression in each tumor. The hallmark of the study was the detection of mdm2-P2 transcripts in 12 of 20 oral SCCs overexpressing both MDM2 and p53 proteins while harboring wild-type p53 alleles. Furthermore, mdm2 amplification was an infrequent event in betel- and tobacco-associated oral tumorigenesis. The differential compartmentalization of the three isoforms of MDM2 suggests that each has a distinct function, potentially in the regulation of p53 and other gene products implicated in oral tumorigenesis. In conclusion, we report herein the first evidence suggesting that enhanced translation of mdm2-P2 transcripts (S-mdm2) may represent an important mechanism of overexpression and consequent stabilization and functional inactivation of wild-type p53 serving as an adverse prognosticator in betel- and tobacco-related oral cancer. The clinical significance of the functional inactivation of wild-type p53 by MDM2 is underscored by the significantly shorter median disease-free survival time (16 months) observed in p53/MDM2-positive cases as compared to those which did not show co-expression of these proteins (median time, 26 months; P = 0.02). PMID:10934161

MDM2 restrains estrogen-mediated AKT activation by promoting TBK1-dependent HPIP degradation

PubMed Central

Shostak, K; Patrascu, F; Göktuna, S I; Close, P; Borgs, L; Nguyen, L; Olivier, F; Rammal, A; Brinkhaus, H; Bentires-Alj, M; Marine, J-C; Chariot, A

2014-01-01

Restoration of p53 tumor suppressor function through inhibition of its interaction and/or enzymatic activity of its E3 ligase, MDM2, is a promising therapeutic approach to treat cancer. However, because the MDM2 targetome extends beyond p53, MDM2 inhibition may also cause unwanted activation of oncogenic pathways. Accordingly, we identified the microtubule-associated HPIP, a positive regulator of oncogenic AKT signaling, as a novel MDM2 substrate. MDM2-dependent HPIP degradation occurs in breast cancer cells on its phosphorylation by the estrogen-activated kinase TBK1. Importantly, decreasing Mdm2 gene dosage in mouse mammary epithelial cells potentiates estrogen-dependent AKT activation owing to HPIP stabilization. In addition, we identified HPIP as a novel p53 transcriptional target, and pharmacological inhibition of MDM2 causes p53-dependent increase in HPIP transcription and also prevents HPIP degradation by turning off TBK1 activity. Our data indicate that p53 reactivation through MDM2 inhibition may result in ectopic AKT oncogenic activity by maintaining HPIP protein levels. PMID:24488098

Structure-function insights into direct lipid transfer between membranes by Mmm1-Mdm12 of ERMES.

PubMed

Kawano, Shin; Tamura, Yasushi; Kojima, Rieko; Bala, Siqin; Asai, Eri; Michel, Agnès H; Kornmann, Benoît; Riezman, Isabelle; Riezman, Howard; Sakae, Yoshitake; Okamoto, Yuko; Endo, Toshiya

2018-03-05

The endoplasmic reticulum (ER)-mitochondrial encounter structure (ERMES) physically links the membranes of the ER and mitochondria in yeast. Although the ER and mitochondria cooperate to synthesize glycerophospholipids, whether ERMES directly facilitates the lipid exchange between the two organelles remains controversial. Here, we compared the x-ray structures of an ERMES subunit Mdm12 from Kluyveromyces lactis with that of Mdm12 from Saccharomyces cerevisiae and found that both Mdm12 proteins possess a hydrophobic pocket for phospholipid binding. However in vitro lipid transfer assays showed that Mdm12 alone or an Mmm1 (another ERMES subunit) fusion protein exhibited only a weak lipid transfer activity between liposomes. In contrast, Mdm12 in a complex with Mmm1 mediated efficient lipid transfer between liposomes. Mutations in Mmm1 or Mdm12 impaired the lipid transfer activities of the Mdm12-Mmm1 complex and furthermore caused defective phosphatidylserine transport from the ER to mitochondrial membranes via ERMES in vitro. Therefore, the Mmm1-Mdm12 complex functions as a minimal unit that mediates lipid transfer between membranes. © 2018 Kawano et al.

Designing dual inhibitors of Mdm2/MdmX: Unexpected coupling of water with gatekeeper Y100/99.

PubMed

Lee, Xiong An; Verma, Chandra; Sim, Adelene Y L

2017-08-01

Mdm2 and MdmX share high structural similarity in their N-terminal domains, yet dual inhibitors are challenging to design due to differences in the conformations of the binding pockets, and notably of the proposed gatekeeper residue, Y100/99. Analysis of crystal structures and molecular dynamics (MD) simulations of complexes of Mdm2 and MdmX resulted in the identification of a water molecule with a long residence time that appears to be modulated by the conformation of Y100/99. These observations lead us to speculate that dual inhibitors either (i) stabilize both Mdm2 and MdmX with Y100/99 in the open conformation typically seen in complexes of Mdm2 with p53, or (ii) the dual inhibitors are agnostic to the conformation of Y100/99. The recently developed potent dual inhibitory stapled peptide Atsp7041 appears to be agnostic to the conformation of the gatekeeper residue. Proteins 2017; 85:1493-1506. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Oncogenic c-Myc-induced lymphomagenesis is inhibited non-redundantly by the p19Arf–Mdm2–p53 and RP–Mdm2–p53 pathways

PubMed Central

Meng, X; Carlson, NR; Dong, J; Zhang, Y

2016-01-01

The multifaceted oncogene c-Myc plays important roles in the development and progression of human cancer. Recent in vitro and in vivo studies have shown that the p19Arf–Mdm2–p53 and the ribosomal protein (RP)–Mdm2–p53 pathways are both essential in preventing oncogenic c-Myc-induced tumorigenesis. Disruption of each pathway individually by p19Arf deletion or by Mdm2C305F mutation, which disrupts RP-Mdm2 binding, accelerates Eμ-myc transgene-induced pre-B/B-cell lymphoma in mice at seemingly similar paces with median survival around 10 and 11 weeks, respectively, compared to 20 weeks for Eμ-myc transgenic mice. Because p19Arf can inhibit ribosomal biogenesis through its interaction with nucleophosmin (NPM/B23), RNA helicase DDX5 and RNA polymerase I transcription termination factor (TTF-I), it has been speculated that the p19Arf–Mdm2–p53 and the RP–Mdm2–p53 pathways might be a single p19Arf–RP–Mdm2–p53 pathway, in which p19Arf activates p53 by inhibiting RP biosynthesis; thus, p19Arf deletion or Mdm2C305F mutation would result in similar consequences. Here, we generated mice with concurrent p19Arf deletion and Mdm2C305F mutation and investigated the compound mice for tumorigenesis in the absence and the presence of oncogenic c-Myc overexpression. In the absence of Eμ-myc transgene, the Mdm2C305F mutation did not elicit spontaneous tumors in mice, nor did it accelerate spontaneous tumors in mice with p19Arf deletion. In the presence of Eμ-myc transgene, however, Mdm2C305F mutation significantly accelerated p19Arf deletion-induced lymphomagenesis and promoted rapid metastasis. We found that when p19Arf–Mdm2–p53 and RP–Mdm2–p53 pathways are independently disrupted, oncogenic c-Myc-induced p53 stabilization and activation is only partially attenuated. When both pathways are concurrently disrupted, however, c-Myc-induced p53 stabilization and activation are essentially obliterated. Thus, the p19Arf–Mdm2–p53 and the RP–Mdm2–p53 are non-redundant pathways possessing similar capabilities to activate p53 upon c-Myc overexpression. PMID:25823025

Isoindolinone inhibitors of the murine double minute 2 (MDM2)-p53 protein-protein interaction: structure-activity studies leading to improved potency.

PubMed

Hardcastle, Ian R; Liu, Junfeng; Valeur, Eric; Watson, Anna; Ahmed, Shafiq U; Blackburn, Timothy J; Bennaceur, Karim; Clegg, William; Drummond, Catherine; Endicott, Jane A; Golding, Bernard T; Griffin, Roger J; Gruber, Jan; Haggerty, Karen; Harrington, Ross W; Hutton, Claire; Kemp, Stuart; Lu, Xiaohong; McDonnell, James M; Newell, David R; Noble, Martin E M; Payne, Sara L; Revill, Charlotte H; Riedinger, Christiane; Xu, Qing; Lunec, John

2011-03-10

Inhibition of the MDM2-p53 interaction has been shown to produce an antitumor effect, especially in MDM2 amplified tumors. The isoindolinone scaffold has proved to be versatile for the discovery of MDM2-p53 antagonists. Optimization of previously reported inhibitors, for example, NU8231 (7) and NU8165 (49), was guided by MDM2 NMR titrations, which indicated key areas of the binding interaction to be explored. Variation of the 2-N-benzyl and 3-alkoxy substituents resulted in the identification of 3-(4-chlorophenyl)-3-((1-(hydroxymethyl)cyclopropyl)methoxy)-2-(4-nitrobenzyl)isoindolin-1-one (74) as a potent MDM2-p53 inhibitor (IC(50) = 0.23 ± 0.01 μM). Resolution of the enantiomers of 74 showed that potent MDM2-p53 activity primarily resided with the (+)-R-enantiomer (74a; IC(50) = 0.17 ± 0.02 μM). The cellular activity of key compounds has been examined in cell lines with defined p53 and MDM2 status. Compound 74a activates p53, MDM2, and p21 transcription in MDM2 amplified cells and shows moderate selectivity for wild-type p53 cell lines in growth inhibition assays.

The role of MDM2 and MDM4 in breast cancer development and prevention.

PubMed

Haupt, Sue; Vijayakumaran, Reshma; Miranda, Panimaya Jeffreena; Burgess, Andrew; Lim, Elgene; Haupt, Ygal

2017-02-01

The major cause of death from breast cancer is not the primary tumour, but relapsing, drug-resistant, metastatic disease. Identifying factors that contribute to aggressive cancer offers important leads for therapy. Inherent defence against carcinogens depends on the individual molecular make-up of each person. Important molecular determinants of these responses are under the control of the mouse double minute (MDM) family: comprised of the proteins MDM2 and MDM4. In normal, healthy adult cells, the MDM family functions to critically regulate measured, cellular responses to stress and subsequent recovery. Proper function of the MDM family is vital for normal breast development, but also for preserving genomic fidelity. The MDM family members are best characterized for their negative regulation of the major tumour suppressor p53 to modulate stress responses. Their impact on other cellular regulators is emerging. Inappropriately elevated protein levels of the MDM family are highly associated with an increased risk of cancer incidence. Exploration of the MDM family members as cancer therapeutic targets is relevant for designing tailored anti-cancer treatments, but successful approaches must strategically consider the impact on both the target cancer and adjacent healthy cells and tissues. This review focuses on recent findings pertaining to the role of the MDM family in normal and malignant breast cells. © The Author (2017). Published by Oxford University Press on behalf of Journal of Molecular Cell Biology, IBCB, SIBS, CAS.

A proteomic screen reveals the mitochondrial outer membrane protein Mdm34p as an essential target of the F-box protein Mdm30p.

PubMed

Ota, Kazuhisa; Kito, Keiji; Okada, Satoshi; Ito, Takashi

2008-10-01

Ubiquitination plays various critical roles in eukaryotic cellular regulation and is mediated by a cascade of enzymes including ubiquitin protein ligase (E3). The Skp1-Cullin-F-box protein complex comprises the largest E3 family, in each member of which a unique F-box protein binds its targets to define substrate specificity. Although genome sequencing uncovers a growing number of F-box proteins, most of them have remained as "orphans" because of the difficulties in identification of their substrates. To address this issue, we tested a quantitative proteomic approach by combining the stable isotope labeling by amino acids in cell culture (SILAC), parallel affinity purification (PAP) that we had developed for efficient enrichment of ubiquitinated proteins, and mass spectrometry (MS). We applied this SILAC-PAP-MS approach to compare ubiquitinated proteins between yeast cells with and without over-expressed Mdm30p, an F-box protein implicated in mitochondrial morphology. Consequently, we identified the mitochondrial outer membrane protein Mdm34p as a target of Mdm30p. Furthermore, we found that mitochondrial defects induced by deletion of MDM30 are not only recapitulated by a mutant Mdm34p defective in interaction with Mdm30p but alleviated by ubiquitination-mimicking forms of Mdm34p. These results indicate that Mdm34p is a physiologically important target of Mdm30p.

Do We Need to Be Silent to Be Extremely Polite? Silence and FTAs.

ERIC Educational Resources Information Center

Sifianou, Maria

1995-01-01

This article discusses the relationship between silence and politeness in face-to-face communication, focusing on Brown and Levinson's (1978) theory of politeness that asserts that it is in the mutual self-interest of individuals engaged in conversation not to initiate face threatening acts (FTAs). (29 references) (MDM)

Taking It Down: Notetaking Practices of L1 and L2 Students.

ERIC Educational Resources Information Center

Clerehan, Rosemary

1995-01-01

This study examined notes taken by 29 undergraduate native and non-native speakers of English during a lecture on commercial law. It found that native speakers took more detailed notes and more accurately recorded the hierarchical structure and principal elements of the lecture than non-native speakers. (48 references) (MDM)

Stress Analysis of Pallet Lever Shaft

DTIC Science & Technology

1976-03-01

ductile, plastic failure. 34 ^Ki’ ■^ ’- l^f. REFERENCES 1. L. Farace , "Runaway Escapement Redesign M125A1 Modular Booster", Tech... Farace 1 Attn: MDC 1 Attn: MDC-A, Mr. F. Shinaly 1 Attn: MDM 1 Attn: MDS 1 Attn: MDS-S 1 Attn: FI 1 Attn: MT Frankford Arsenal (Cont) 1

Speaking Practice in the Medical English Classroom: Bridging the Gap between Medical English and the Everyday World.

ERIC Educational Resources Information Center

Webber, Pauline

1995-01-01

Discusses teaching methods and techniques for use in English for Special Purposes classrooms, focusing on conversation and speaking exercises for medical students and professionals that combine medical terminology and everyday usage. Examples include doctor-patient dialogues and group discussions of general interest topics. (15 references) (MDM)

Targeting MDM4 as a Novel Therapeutic Approach for Hematologic Malignancies.

PubMed

Cao, Lei; Fan, Lei; Xu, Wei; Li, Jian-Yong

2015-01-01

Mouse double minute 4 (MDM4) as a member of MDM family, is an oncogene emerging as an imperative negative regulator of p53. Tumor suppressor protein p53 plays a crucial role in cell cycle arrest, apoptosis and homeostasis. It has been reported that frequent inactivation of p53 was observed in numerous human cancers including hematologic malignancies. MDM4, the newly discovered modulator of p53 protein, is frequently amplified in various solid tumors such as cutaneous melanoma, retinoblastoma and hematological malignances such as chronic lymphocytic leukemia, acute myeloid leukemia and mantle cell lymphoma. Multiple evidences implicate that over-expression of MDM4 is associated with tumor progression and poor prognosis which can be reversed by knockdown of MDM4 expression or restoration of p53 function, and support the rationale for the design of future MDM4-specific therapeutics. This article discusses and focuses on using MDM4 as a novel biomarker as well as a therapeutic target for hematologic malignancies.

Ubiquitin ligase parkin promotes Mdm2-arrestin interaction but inhibits arrestin ubiquitination.

PubMed

Ahmed, M Rafiuddin; Zhan, Xuanzhi; Song, Xiufeng; Kook, Seunghyi; Gurevich, Vsevolod V; Gurevich, Eugenia V

2011-05-10

Numerous mutations in E3 ubiquitin ligase parkin were shown to associate with familial Parkinson's disease. Here we show that parkin binds arrestins, versatile regulators of cell signaling. Arrestin-parkin interaction was demonstrated by coimmunoprecipitation of endogenous proteins from brain tissue and shown to be direct using purified proteins. Parkin binding enhances arrestin interactions with another E3 ubiquitin ligase, Mdm2, apparently by shifting arrestin conformational equilibrium to the basal state preferred by Mdm2. Although Mdm2 was reported to ubiquitinate arrestins, parkin-dependent increase in Mdm2 binding dramatically reduces the ubiquitination of both nonvisual arrestins, basal and stimulated by receptor activation, without affecting receptor internalization. Several disease-associated parkin mutations differentially affect the stimulation of Mdm2 binding. All parkin mutants tested effectively suppress arrestin ubiquitination, suggesting that bound parkin shields arrestin lysines targeted by Mdm2. Parkin binding to arrestins along with its effects on arrestin interaction with Mdm2 and ubiquitination is a novel function of this protein with implications for Parkinson's disease pathology.

Shaping nanoscale magnetic domain memory in exchange-coupled ferromagnets by field cooling.

PubMed

Chesnel, Karine; Safsten, Alex; Rytting, Matthew; Fullerton, Eric E

2016-06-01

The advance of magnetic nanotechnologies relies on detailed understanding of nanoscale magnetic mechanisms in materials. Magnetic domain memory (MDM), that is, the tendency for magnetic domains to repeat the same pattern during field cycling, is important for magnetic recording technologies. Here we demonstrate MDM in [Co/Pd]/IrMn films, using coherent X-ray scattering. Under illumination, the magnetic domains in [Co/Pd] produce a speckle pattern, a unique fingerprint of their nanoscale configuration. We measure MDM by cross-correlating speckle patterns throughout magnetization processes. When cooled below its blocking temperature, the film exhibits up to 100% MDM, induced by exchange-coupling with the underlying IrMn layer. The degree of MDM drastically depends on cooling conditions. If the film is cooled under moderate fields, MDM is high throughout the entire magnetization loop. If the film is cooled under nearly saturating field, MDM vanishes, except at nucleation and saturation. Our findings show how to fully control the occurrence of MDM by field cooling.

Shaping nanoscale magnetic domain memory in exchange-coupled ferromagnets by field cooling

DOE PAGES

Chesnel, Karine; Safsten, Alex; Rytting, Matthew; ...

2016-06-01

The advance of magnetic nanotechnologies relies on detailed understanding of nanoscale magnetic mechanisms in materials. Magnetic domain memory (MDM), that is, the tendency for magnetic domains to repeat the same pattern during field cycling, is important for magnetic recording technologies. Here we demonstrate MDM in [Co/Pd]/IrMn films, using coherent X-ray scattering. Under illumination, the magnetic domains in [Co/Pd] produce a speckle pattern, a unique fingerprint of their nanoscale configuration. We measure MDM by cross-correlating speckle patterns throughout magnetization processes. When cooled below its blocking temperature, the film exhibits up to 100% MDM, induced by exchange-coupling with the underlying IrMn layer.more » The degree of MDM drastically depends on cooling conditions. If the film is cooled under moderate fields, MDM is high throughout the entire magnetization loop. Lastly, if the film is cooled under nearly saturating field, MDM vanishes, except at nucleation and saturation. Our findings show how to fully control the occurrence of MDM by field cooling.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chesnel, Karine; Safsten, Alex; Rytting, Matthew

The advance of magnetic nanotechnologies relies on detailed understanding of nanoscale magnetic mechanisms in materials. Magnetic domain memory (MDM), that is, the tendency for magnetic domains to repeat the same pattern during field cycling, is important for magnetic recording technologies. Here we demonstrate MDM in [Co/Pd]/IrMn films, using coherent X-ray scattering. Under illumination, the magnetic domains in [Co/Pd] produce a speckle pattern, a unique fingerprint of their nanoscale configuration. We measure MDM by cross-correlating speckle patterns throughout magnetization processes. When cooled below its blocking temperature, the film exhibits up to 100% MDM, induced by exchange-coupling with the underlying IrMn layer.more » The degree of MDM drastically depends on cooling conditions. If the film is cooled under moderate fields, MDM is high throughout the entire magnetization loop. Lastly, if the film is cooled under nearly saturating field, MDM vanishes, except at nucleation and saturation. Our findings show how to fully control the occurrence of MDM by field cooling.« less

Shaping nanoscale magnetic domain memory in exchange-coupled ferromagnets by field cooling

PubMed Central

Chesnel, Karine; Safsten, Alex; Rytting, Matthew; Fullerton, Eric E.

2016-01-01

The advance of magnetic nanotechnologies relies on detailed understanding of nanoscale magnetic mechanisms in materials. Magnetic domain memory (MDM), that is, the tendency for magnetic domains to repeat the same pattern during field cycling, is important for magnetic recording technologies. Here we demonstrate MDM in [Co/Pd]/IrMn films, using coherent X-ray scattering. Under illumination, the magnetic domains in [Co/Pd] produce a speckle pattern, a unique fingerprint of their nanoscale configuration. We measure MDM by cross-correlating speckle patterns throughout magnetization processes. When cooled below its blocking temperature, the film exhibits up to 100% MDM, induced by exchange-coupling with the underlying IrMn layer. The degree of MDM drastically depends on cooling conditions. If the film is cooled under moderate fields, MDM is high throughout the entire magnetization loop. If the film is cooled under nearly saturating field, MDM vanishes, except at nucleation and saturation. Our findings show how to fully control the occurrence of MDM by field cooling. PMID:27248368

Simulating Molecular Mechanisms of the MDM2-Mediated Regulatory Interactions: A Conformational Selection Model of the MDM2 Lid Dynamics

PubMed Central

Verkhivker, Gennady M.

2012-01-01

Diversity and complexity of MDM2 mechanisms govern its principal function as the cellular antagonist of the p53 tumor suppressor. Structural and biophysical studies have demonstrated that MDM2 binding could be regulated by the dynamics of a pseudo-substrate lid motif. However, these experiments and subsequent computational studies have produced conflicting mechanistic models of MDM2 function and dynamics. We propose a unifying conformational selection model that can reconcile experimental findings and reveal a fundamental role of the lid as a dynamic regulator of MDM2-mediated binding. In this work, structure, dynamics and energetics of apo-MDM2 are studied as a function of posttranslational modifications and length of the lid. We found that the dynamic equilibrium between “closed” and “semi-closed” lid forms may be a fundamental characteristic of MDM2 regulatory interactions, which can be modulated by phosphorylation, phosphomimetic mutation as well as by the lid size. Our results revealed that these factors may regulate p53-MDM2 binding by fine-tuning the thermodynamic equilibrium between preexisting conformational states of apo-MDM2. In agreement with NMR studies, the effect of phosphorylation on MDM2 interactions was more pronounced with the truncated lid variant that favored the thermodynamically dominant closed form. The phosphomimetic mutation S17D may alter the lid dynamics by shifting the thermodynamic equilibrium towards the ensemble of “semi-closed” conformations. The dominant “semi-closed” lid form and weakened dependence on the phosphorylation seen in simulations with the complete lid can provide a rationale for binding of small p53-based mimetics and inhibitors without a direct competition with the lid dynamics. The results suggested that a conformational selection model of preexisting MDM2 states may provide a robust theoretical framework for understanding MDM2 dynamics. Probing biological functions and mechanisms of MDM2 regulation would require further integration of computational and experimental studies and may help to guide drug design of novel anti-cancer therapeutics. PMID:22815859

Auto-ubiquitination of Mdm2 Enhances Its Substrate Ubiquitin Ligase Activity*

PubMed Central

Ranaweera, Ruchira S.; Yang, Xiaolu

2013-01-01

The RING domain E3 ubiquitin ligase Mdm2 is the master regulator of the tumor suppressor p53. It targets p53 for proteasomal degradation, restraining the potent activity of p53 and enabling cell survival and proliferation. Like most E3 ligases, Mdm2 can also ubiquitinate itself. How Mdm2 auto-ubiquitination may influence its substrate ubiquitin ligase activity is undefined. Here we show that auto-ubiquitination of Mdm2 is an activating event. Mdm2 that has been conjugated to polyubiquitin chains, but not to single ubiquitins, exhibits substantially enhanced activity to polyubiquitinate p53. Mechanistically, auto-ubiquitination of Mdm2 facilitates the recruitment of the E2 ubiquitin-conjugating enzyme. This occurs through noncovalent interactions between the ubiquitin chains on Mdm2 and the ubiquitin binding domain on E2s. Mutations that diminish the noncovalent interactions render auto-ubiquitination unable to stimulate Mdm2 substrate E3 activity. These results suggest a model in which polyubiquitin chains on an E3 increase the local concentration of E2 enzymes and permit the processivity of substrate ubiquitination. They also support the notion that autocatalysis may be a prevalent mode for turning on the activity of latent enzymes. PMID:23671280

Implementation rates of uro-oncology multidisciplinary meeting decisions.

PubMed

Kinnear, Ned; Smith, Riley; Hennessey, Derek B; Bolton, Damien; Sengupta, Shomik

2017-11-01

To assess implementation rates of the consensus plans made at the uro-oncology multidisciplinary meeting (MDM) of an Australian tertiary centre, and analyse obstacles to implementation. A retrospective review was performed of all patients discussed at the uro-oncology MDM at our institution between 1 January and 30 June 2015. Rates of referral for MDM discussion after a new histological diagnosis of malignancy, categorised by tumour type, were assessed. Patient records were interrogated to confirm MDM plan implementation, with the outcomes examined being completion of MDM plan within 3 months and factors preventing implementation. During the enrolment period, from 291 uro-oncological procedures, 240 yielded malignant histology of which 160 (67%) were discussed at the MDM. Overall, 202 patients, including 32 females, were discussed at the uro-oncology MDM. MDM consensus plans were implemented in 184 (91.1%) patients. Reasons for deviation from the MDM plan included delay in care, patient deterioration or comorbidities, patient preference, consultant decision, loss to follow-up, and change in patient scenario due to additional new information. The MDM is increasingly important in the care of uro-oncology patients, with about two-thirds of new diagnoses currently captured. There appear to be few barriers to the implementation of consensus plans, with nearly all patients undergoing the recommended management. © 2017 The Authors BJU International © 2017 BJU International Published by John Wiley & Sons Ltd.

Distinct downstream targets manifest p53-dependent pathologies in mice.

PubMed

Pant, V; Xiong, S; Chau, G; Tsai, K; Shetty, G; Lozano, G

2016-11-03

Mdm2, the principal negative regulator of p53, is critical for survival, a fact clearly demonstrated by the p53-dependent death of germline or conditional mice following deletion of Mdm2. On the other hand, Mdm2 hypomorphic (Mdm2 Puro/Δ7-12 ) or heterozygous (Mdm2 +/- ) mice that express either 30 or 50% of normal Mdm2 levels, respectively, are viable but present distinct phenotypes because of increased p53 activity. Mdm2 levels are also transcriptionally regulated by p53. We evaluated the significance of this reciprocal relationship in a new hypomorphic mouse model inheriting an aberrant Mdm2 allele with insertion of the neomycin cassette and deletion of 184-bp sequence in intron 3. These mice also carry mutations in the Mdm2 P2-promoter and thus express suboptimal levels of Mdm2 entirely encoded from the P1-promoter. Resulting mice exhibit abnormalities in skin pigmentation and reproductive tissue architecture, and are subfertile. Notably, all these phenotypes are rescued on a p53-null background. Furthermore, these phenotypes depend on distinct p53 downstream activities as genetic ablation of the pro-apoptotic gene Puma reverts the reproductive abnormalities but not skin hyperpigmentation, whereas deletion of cell cycle arrest gene p21 does not rescue either phenotype. Moreover, p53-mediated upregulation of Kitl influences skin pigmentation. Altogether, these data emphasize tissue-specific p53 activities that regulate cell fate.

p53-Independent Roles of MDM2 in NF-κB Signaling: Implications for Cancer Therapy, Wound Healing, and Autoimmune Diseases1

PubMed Central

Thomasova, Dana; Mulay, Shrikant R; Bruns, Hauke; Anders, Hans-Joachim

2012-01-01

Murine double minute-2 (MDM2) is an intracellular molecule with multiple biologic functions. It serves as a negative regulator of p53 and thereby limits cell cycle arrest and apoptosis. Because MDM2 blockade suppresses tumor cell growth in vitro and in vivo, respective MDM2 inhibition is currently evaluated as anti-cancer therapy in clinical trials. However, the anti-proliferative effects of MDM2 inhibition also impair regenerative cell growth upon tissue injury. This was so far documented for tubular repair upon postischemic acute kidney injury and might apply to wound healing responses in general. Furthermore, MDM2 has numerous p53-independent effects. As a new entry, MDM2 was identified to act as a co-transcription factor for nuclear factor-kappa-light-enhancer of activated B cells (NF-κB) at cytokine promoters. This explains the potent anti-inflammatory effects of MDM2 inhibitors in vitro and in vivo. For example, the NF-κB-antagonistic and p53-agonistic activities of MDM2 inhibitors elicit potent therapeutic effects on experimental lymphoproliferative autoimmune disorders such as systemic lupus erythematosus. In this review, we discuss the classic p53-dependent, the recently discovered p53-independent, and the NF-κB-agonistic biologic functions of MDM2. We describe its complex regulatory role on p53 and NF-κB signaling and name areas of research that may help to foresee previously unexpected effects or potential alternative indications of therapeutic MDM2 blockade. PMID:23308042

Regulation of MDM2 Activity by Nucleolin

DTIC Science & Technology

2005-06-01

tumorigenesis with -50% of human cancers showing mutation of the TP53 gene , often a loss of one gene copy and a point mutation within the second. p53...Sordat B, Gillet M, Schorderet D, Bosman FT, Chaubert P (2001) Methylation silencing and mutations of the p14ARF and pl6INK4a genes in colon cancer. Lab...for the first machinery (for example, see reference 53 and references step of pre-rRNA processing (22). Mutation of the genes en- therein). It is

Native PAGE to study the interaction between the oncosuppressor p53 and its protein ligands.

PubMed

Lamberti, Anna; Sgammato, Roberta; Desiderio, Doriana; Punzo, Chiara; Raimo, Gennaro; Novellino, Ettore; Carotenuto, Alfonso; Masullo, Mariorosario

2015-02-01

In the present study, we investigated a new approach for studying the interaction between p53 and MDM2/X (where MDM is murine double minute protein). The method is based on the different mobility between the interacting domains of the oncosuppressor p53 and its protein ligands MDM2/X on polyacrylamide gels under native conditions. While the two proteins MDM2/X alone were able to enter the gel, the formation of a binary complex between p53 and MDM2/X prevented the gel entry. The novel technique is reliable for determining the different affinity elicited by MDM2 or MDMX toward p53, and can be useful for analyzing the dissociation power exerted by other molecules on the p53-MDM2/X complex. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

MDM4 is a key therapeutic target in cutaneous melanoma

PubMed Central

Gembarska, Agnieszka; Luciani, Flavie; Fedele, Clare; Russell, Elisabeth A; Dewaele, Michael; Villar, Stéphanie; Zwolinska, Aleksandra; Haupt, Sue; de Lange, Job; Yip, Dana; Goydos, James; Haigh, Jody J; Haupt, Ygal; Larue, Lionel; Jochemsen, Aart; Shi, Hubing; Moriceau, Gatien; Lo, Roger S; Ghanem, Ghanem; Shackleton, Mark; Bernal, Federico; Marine, Jean-Christophe

2013-01-01

The inactivation of the p53 tumor suppressor pathway, which often occurs through mutations in TP53 (encoding tumor protein 53) is a common step in human cancer. However, in melanoma—a highly chemotherapy-resistant disease—TP53 mutations are rare, raising the possibility that this cancer uses alternative ways to overcome p53-mediated tumor suppression. Here we show that Mdm4 p53 binding protein homolog (MDM4), a negative regulator of p53, is upregulated in a substantial proportion (∼65%) of stage I–IV human melanomas and that melanocyte-specific Mdm4 overexpression enhanced tumorigenesis in a mouse model of melanoma induced by the oncogene Nras. MDM4 promotes the survival of human metastatic melanoma by antagonizing p53 proapoptotic function. Notably, inhibition of the MDM4-p53 interaction restored p53 function in melanoma cells, resulting in increased sensitivity to cytotoxic chemotherapy and to inhibitors of the BRAF (V600E) oncogene. Our results identify MDM4 as a key determinant of impaired p53 function in human melanoma and designate MDM4 as a promising target for antimelanoma combination therapy. PMID:22820643

MDM2 copy numbers in well-differentiated and dedifferentiated liposarcoma: characterizing progression to high-grade tumors.

PubMed

Ware, Patrick L; Snow, Anthony N; Gvalani, Maya; Pettenati, Mark J; Qasem, Shadi A

2014-03-01

MDM2 gene amplification is associated with well-differentiated (WDL) and dedifferentiated liposarcomas (DDL). Using fluorescent in situ hybridization (FISH), we sought to characterize various patterns of MDM2 amplification among the morphologic spectrum of liposarcoma. Forty-six cases of liposarcoma in various sites were examined and included 22 WDLs, 14 DLLs, and 10 negative control subjects. The MDM2 amplification ratio (MDM2/CEP12) was lower in WDL (10.2) compared with DDL (18.3) cases (P = .0000002). An amplification ratio of 16 showed optimal sensitivity (0.86) and specificity (0.96) as a cutoff point for progression to DDL. Borderline areas, defined as tumors with increased cellularity and atypia but with preserved lipomatous differentiation, showed a significantly higher MDM2 ratio (17.5; P = .0007) compared with WDL. Central (retroperitoneal and intra-abdominal) tumors also showed a significantly higher MDM2 ratio than peripheral ones (P = .02). Differences in MDM2 amplification profiles among liposarcomas could help further define and predict progression to high-grade neoplasia.

Ubiquitin ligase parkin promotes Mdm2-arrestin interaction but inhibits arrestin ubiquitination

PubMed Central

Ahmed, M. Rafiuddin; Zhan, Xuanzhi; Song, Xiufeng; Kook, Seunghyi; Gurevich, Vsevolod V.; Gurevich, Eugenia V.

2011-01-01

Numerous mutations in E3 ubiquitin ligase parkin were shown to associate with familial Parkinson's disease. Here we show that parkin binds arrestins, versatile regulators of cell signaling. Arrestin-parkin interaction was demonstrated by coimmuno-precipitation of endogenous proteins from brain tissue, and shown to be direct using purified proteins. Parkin binding enhances arrestin interactions with another E3 ubiquitin ligase, Mdm2, apparently by shifting arrestin conformational equilibrium to the basal state preferred by Mdm2. Although Mdm2 was reported to ubiquitinate arrestins, parkin-dependent increase in Mdm2 binding dramatically reduces the ubiquitination of both non-visual arrestins, basal and stimulated by receptor activation, without affecting receptor internalization. Several disease-associated parkin mutations differentially affect the stimulation of Mdm2 binding. All parkin mutants tested effectively suppress arrestin ubiquitination, suggesting that bound parkin shields arrestin lysines targeted by Mdm2. Parkin binding to arrestins along with its effects on arrestin interaction with Mdm2 and ubiquitination is a novel function of this protein with implications for Parkinson's disease pathology. PMID:21466165

Coxsackievirus B4 Can Infect Human Peripheral Blood-Derived Macrophages

PubMed Central

Alidjinou, Enagnon Kazali; Sané, Famara; Trauet, Jacques; Copin, Marie-Christine; Hober, Didier

2015-01-01

Beyond acute infections, group B coxsackieviruses (CVB) are also reported to play a role in the development of chronic diseases, like type 1 diabetes. The viral pathogenesis mainly relies on the interplay between the viruses and innate immune response in genetically-susceptible individuals. We investigated the interaction between CVB4 and macrophages considered as major players in immune response. Monocyte-derived macrophages (MDM) generated with either M-CSF or GM-CSF were inoculated with CVB4, and infection, inflammation, viral replication and persistence were assessed. M-CSF-induced MDM, but not GM-CSF-induced MDM, can be infected by CVB4. In addition, enhancing serum was not needed to infect MDM in contrast with parental monocytes. The expression of viral receptor (CAR) mRNA was similar in both M-CSF and GM-CSF MDM. CVB4 induced high levels of pro-inflammatory cytokines (IL-6 and TNFα) in both MDM populations. CVB4 effectively replicated and persisted in M-CSF MDM, but IFNα was produced in the early phase of infection only. Our results demonstrate that CVB4 can replicate and persist in MDM. Further investigations are required to determine whether the interaction between the virus and MDM plays a role in the pathogenesis of CVB-induced chronic diseases. PMID:26610550

Coxsackievirus B4 Can Infect Human Peripheral Blood-Derived Macrophages.

PubMed

Alidjinou, Enagnon Kazali; Sané, Famara; Trauet, Jacques; Copin, Marie-Christine; Hober, Didier

2015-11-24

Beyond acute infections, group B coxsackieviruses (CVB) are also reported to play a role in the development of chronic diseases, like type 1 diabetes. The viral pathogenesis mainly relies on the interplay between the viruses and innate immune response in genetically-susceptible individuals. We investigated the interaction between CVB4 and macrophages considered as major players in immune response. Monocyte-derived macrophages (MDM) generated with either M-CSF or GM-CSF were inoculated with CVB4, and infection, inflammation, viral replication and persistence were assessed. M-CSF-induced MDM, but not GM-CSF-induced MDM, can be infected by CVB4. In addition, enhancing serum was not needed to infect MDM in contrast with parental monocytes. The expression of viral receptor (CAR) mRNA was similar in both M-CSF and GM-CSF MDM. CVB4 induced high levels of pro-inflammatory cytokines (IL-6 and TNFα) in both MDM populations. CVB4 effectively replicated and persisted in M-CSF MDM, but IFNα was produced in the early phase of infection only. Our results demonstrate that CVB4 can replicate and persist in MDM. Further investigations are required to determine whether the interaction between the virus and MDM plays a role in the pathogenesis of CVB-induced chronic diseases.

BTK blocks the inhibitory effects of MDM2 on p53 activity

PubMed Central

Rada, Miran; Althubiti, Mohammad; Ekpenyong-Akiba, Akang E.; Lee, Koon-Guan; Lam, Kong Peng; Fedorova, Olga; Barlev, Nickolai A.; Macip, Salvador

2017-01-01

p53 is a tumour suppressor that is activated in response to various types of stress. It is regulated by a complex pattern of over 50 different post-translational modifications, including ubiquitination by the E3 ligase MDM2, which leads to its proteasomal degradation. We have previously reported that expression of Bruton’s Tyrosine Kinase (BTK) induces phosphorylation of p53 at the N-terminus, including Serine 15, and increases its protein levels and activity. The mechanisms involved in this process are not completely understood. Here, we show that BTK also increases MDM2 and is necessary for MDM2 upregulation after DNA damage, consistent with what we have shown for other p53 target genes. Moreover, we found that BTK binds to MDM2 on its PH domain and induces its phosphorylation. This suggested a negative regulation of MDM2 functions by BTK, supported by the fact BTK expression rescued the inhibitory effects of MDM2 on p53 transcriptional activity. Indeed, we observed that BTK mediated the loss of the ubiquitination activity of MDM2, a process that was dependent on the phosphorylation functions of BTK. Our data together shows that the kinase activity of BTK plays an important role in disrupting the MDM2-p53 negative feedback loop by acting at different levels, including binding to and inactivation of MDM2. This study provides a potential mechanism to explain how BTK modulates p53 functions. PMID:29290977

The Clustered, Regularly Interspaced, Short Palindromic Repeats-associated Endonuclease 9 (CRISPR/Cas9)-created MDM2 T309G Mutation Enhances Vitreous-induced Expression of MDM2 and Proliferation and Survival of Cells.

PubMed

Duan, Yajian; Ma, Gaoen; Huang, Xionggao; D'Amore, Patricia A; Zhang, Feng; Lei, Hetian

2016-07-29

The G309 allele of SNPs in the mouse double minute (MDM2) promoter locus is associated with a higher risk of cancer and proliferative vitreoretinopathy (PVR), but whether SNP G309 contributes to the pathogenesis of PVR is to date unknown. The clustered regularly interspaced short palindromic repeats (CRISPR)-associated endonuclease (Cas) 9 from Streptococcus pyogenes (SpCas9) can be harnessed to manipulate a single or multiple nucleotides in mammalian cells. Here we delivered SpCas9 and guide RNAs using dual adeno-associated virus-derived vectors to target the MDM2 genomic locus together with a homologous repair template for creating the mutation of MDM2 T309G in human primary retinal pigment epithelial (hPRPE) cells whose genotype is MDM2 T309T. The next-generation sequencing results indicated that there was 42.51% MDM2 G309 in the edited hPRPE cells using adeno-associated viral CRISPR/Cas9. Our data showed that vitreous induced an increase in MDM2 and subsequent attenuation of p53 expression in MDM2 T309G hPRPE cells. Furthermore, our experimental results demonstrated that MDM2 T309G in hPRPE cells enhanced vitreous-induced cell proliferation and survival, suggesting that this SNP contributes to the pathogenesis of PVR. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Antisense oligonucleotide–mediated MDM4 exon 6 skipping impairs tumor growth

PubMed Central

Dewaele, Michael; Tabaglio, Tommaso; Willekens, Karen; Bezzi, Marco; Teo, Shun Xie; Low, Diana H.P.; Koh, Cheryl M.; Rambow, Florian; Fiers, Mark; Rogiers, Aljosja; Radaelli, Enrico; Al-Haddawi, Muthafar; Tan, Soo Yong; Hermans, Els; Amant, Frederic; Yan, Hualong; Lakshmanan, Manikandan; Koumar, Ratnacaram Chandrahas; Lim, Soon Thye; Derheimer, Frederick A.; Campbell, Robert M.; Bonday, Zahid; Tergaonkar, Vinay; Shackleton, Mark; Blattner, Christine; Marine, Jean-Christophe; Guccione, Ernesto

2015-01-01

MDM4 is a promising target for cancer therapy, as it is undetectable in most normal adult tissues but often upregulated in cancer cells to dampen p53 tumor-suppressor function. The mechanisms that underlie MDM4 upregulation in cancer cells are largely unknown. Here, we have shown that this key oncogenic event mainly depends on a specific alternative splicing switch. We determined that while a nonsense-mediated, decay-targeted isoform of MDM4 (MDM4-S) is produced in normal adult tissues as a result of exon 6 skipping, enhanced exon 6 inclusion leads to expression of full-length MDM4 in a large number of human cancers. Although this alternative splicing event is likely regulated by multiple splicing factors, we identified the SRSF3 oncoprotein as a key enhancer of exon 6 inclusion. In multiple human melanoma cell lines and in melanoma patient–derived xenograft (PDX) mouse models, antisense oligonucleotide–mediated (ASO-mediated) skipping of exon 6 decreased MDM4 abundance, inhibited melanoma growth, and enhanced sensitivity to MAPK-targeting therapeutics. Additionally, ASO-based MDM4 targeting reduced diffuse large B cell lymphoma PDX growth. As full-length MDM4 is enhanced in multiple human tumors, our data indicate that this strategy is applicable to a wide range of tumor types. We conclude that enhanced MDM4 exon 6 inclusion is a common oncogenic event and has potential as a clinically compatible therapeutic target. PMID:26595814

Disruption of the RP-MDM2-p53 pathway accelerates APC loss-induced colorectal tumorigenesis.

PubMed

Liu, S; Tackmann, N R; Yang, J; Zhang, Y

2017-03-01

Inactivation of the adenomatous polyposis coli (APC) tumor suppressor is frequently found in colorectal cancer. Loss of APC function results in deregulation of the Wnt/β-catenin signaling pathway causing overexpression of the c-MYC oncogene. In lymphoma, both p19ARF and ribosomal proteins RPL11 and RPL5 respond to c-MYC activation to induce p53. Their role in c-MYC-driven colorectal carcinogenesis is unclear, as p19ARF deletion does not accelerate APC loss-triggered intestinal tumorigenesis. To determine the contribution of the ribosomal protein (RP)-murine double minute 2 (MDM2)-p53 pathway to APC loss-induced tumorigenesis, we crossed mice bearing MDM2 C305F mutation, which disrupts RPL11- and RPL5-MDM2 binding, with Apc min/+ mice, which are prone to intestinal tumor formation. Interestingly, loss of RP-MDM2 binding significantly accelerated colorectal tumor formation while having no discernable effect on small intestinal tumor formation. Mechanistically, APC loss leads to overexpression of c-MYC, RPL11 and RPL5 in mouse colonic tumor cells irrespective of MDM2 C305F mutation. However, notable p53 stabilization and activation were observed only in Apc min/+ ;Mdm2 +/+ but not Apc min/+ ;Mdm2 C305F/C305F colon tumors. These data establish that the RP-MDM2-p53 pathway, in contrast to the p19ARF-MDM2-p53 pathway, is a critical mediator of colorectal tumorigenesis following APC loss.

Cardiac-specific ablation of the E3 ubiquitin ligase Mdm2 leads to oxidative stress, broad mitochondrial deficiency and early death

PubMed Central

Hauck, Ludger; Stanley-Hasnain, Shanna; Fung, Amelia; Grothe, Daniela; Rao, Vivek; Mak, Tak W.

2017-01-01

The maintenance of normal heart function requires proper control of protein turnover. The ubiquitin-proteasome system is a principal regulator of protein degradation. Mdm2 is the main E3 ubiquitin ligase for p53 in mitotic cells thereby regulating cellular growth, DNA repair, oxidative stress and apoptosis. However, which of these Mdm2-related activities are preserved in differentiated cardiomyocytes has yet to be determined. We sought to elucidate the role of Mdm2 in the control of normal heart function. We observed markedly reduced Mdm2 mRNA levels accompanied by highly elevated p53 protein expression in the hearts of wild type mice subjected to myocardial infarction or trans-aortic banding. Accordingly, we generated conditional cardiac-specific Mdm2 gene knockout (Mdm2f/f;mcm) mice. In adulthood, Mdm2f/f;mcm mice developed spontaneous cardiac hypertrophy, left ventricular dysfunction with early mortality post-tamoxifen. A decreased polyubiquitination of myocardial p53 was observed, leading to its stabilization and activation, in the absence of acute stress. In addition, transcriptomic analysis of Mdm2-deficient hearts revealed that there is an induction of E2f1 and c-Myc mRNA levels with reduced expression of the Pgc-1a/Ppara/Esrrb/g axis and Pink1. This was associated with a significant degree of cardiomyocyte apoptosis, and an inhibition of redox homeostasis and mitochondrial bioenergetics. All these processes are early, Mdm2-associated events and contribute to the development of pathological hypertrophy. Our genetic and biochemical data support a role for Mdm2 in cardiac growth control through the regulation of p53, the Pgc-1 family of transcriptional coactivators and the pivotal antioxidant Pink1. PMID:29267372

Role of the Mdm2 SNIP 309 Polymorphism in Gastric Mucosal Morphologic Patterns of Patients with Helicobacter pylori Associated Gastritis.

PubMed

Tongtawee, Taweesak; Dechsukhum, Chavaboon; Leeanansaksiri, Wilairat; Kaewpitoon, Soraya; Kaewpitoon, Natthawut; Loyd, Ryan A; Matrakool, Likit; Panpimanmas, Sukij

2016-01-01

The tumor suppressor p53 is as a regulator of cell proliferation, apoptosis and many other biological processes as well as external and internal stress responses. Mdm2 SNIP309 is a negative regulator of 53. Therefore, this study aimed to determine the role of the Mdm2 SNIP 309 polymorphism in the gastric mucosal morphological patterns in patients with Helicobacter pylori associated gastritis. A prospective cross-sectional study was carried out from November 2014 through November 2015. Biopsy specimens were obtained from patients and infection was proven by positive histology. Gastric mucosa specimens were sent to the Molecular Genetics Unit, Institute of Medicine, Suranaree University of Technology where they were tested by molecular methods to detect the patterns of Mdm2 SNIP 309 polymorphism using the real-time PCR hybridization probe method. The results were analyzed and correlated with gastric mucosal morphological patterns by using C-NBI endoscopy. A total of 300 infected patients were enrolled and gastric mucosa specimens were collected. In this study the percentage of Mdm2 SNIP 309 T/T homozygous and Mdm2 SNIP309 G/T heterozygous was 78% and 19 % respectively whereas Mdm2 SNIP309 G/G homozygous was 3%. Mdm2 SNIP 309 T/T homozygous and Mdm2 SNIP309 G/T heterozygosity correlated with type 1 to type 3 gastric mucosal morphological patterns (P<0.01) whereas Mdm2 SNIP309 G/G homozygous correlated with type 4 and type 5 (P<0.01). Our study finds the frequency of Mdm2 SNIP309 G/G in a Thai population is very low, and suggests that this can explain ae Thailand enigma. Types 1 to type 3 are the most common gastric mucosal morphological patterns according to the unique genetic polymorphism of MDM2 SNIP 309 in the Thai population.

p53-Mdm2 interaction inhibitors as novel nongenotoxic anticancer agents.

PubMed

Nayak, Surendra Kumar; Khatik, Gopal L; Narang, Rakesh; Monga, Vikramdeep; Chopra, Harish Kumar

2017-06-23

Cancer is a major global health problem with high mortality rate. Most of clinically used anticancer agents induce apoptosis through genotoxic stress at various stages of cell cycle and activation of p53. Acting as a tumor suppressor p53 plays a vital role in preventing tumor development. Tumor suppressor function of p53 is effectively antagonized by its direct interaction with murine double minute 2 (Mdm2) proteins via multiple mechanisms. Thus, p53-Mdm2 interaction has been found to be an important target for the development of novel anticancer agents. Currently, nutlin, spirooxindole, isoquilinone and piperidinone analogues inhibiting p53-Mdm2 interaction are found to be promising in the treatment of cancer. The current review focused to scrutinize the structural aspects of p53-Mdm2 interaction inhibitors. The present study provides a detailed collection of published information on different classes of inhibitors of p53-Mdm2 interaction as potential anticancer agents. The review highlighted the structural aspects of various reported p53-Mdm2 inhibitor for optimization. In the last few years, different classes of inhibitors of p53-Mdm2 have been designed and developed, and seven such compounds are being evaluated in clinical trials as new anticancer drugs. Further, to explore the role of p53 protein as a potential target for anticancer drug development, in this review, the mechanism of Mdm2 mediated inactivation of p53 and recent developments on p53-Mdm2 interactions inhibitors are discussed. Agents designed to block the p53-Mdm2 interaction may have a therapeutic potential for treatment of a subset of human cancers retaining wild-type p53. We review herein the recent advances in the design and development of potent small molecules as p53-Mdm2 inhibitors. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Effect of the Flexible Regions of the Oncoprotein Mouse Double Minute X on Inhibitor Binding Affinity.

PubMed

Qin, Lingyun; Liu, Huili; Chen, Rong; Zhou, Jingjing; Cheng, Xiyao; Chen, Yao; Huang, Yongqi; Su, Zhengding

2017-11-07

The oncoprotein MdmX (mouse double minute X) is highly homologous to Mdm2 (mouse double minute 2) in terms of their amino acid sequences and three-dimensional conformations, but Mdm2 inhibitors exhibit very weak affinity for MdmX, providing an excellent model for exploring how protein conformation distinguishes and alters inhibitor binding. The intrinsic conformation flexibility of proteins plays pivotal roles in determining and predicting the binding properties and the design of inhibitors. Although the molecular dynamics simulation approach enables us to understand protein-ligand interactions, the mechanism underlying how a flexible binding pocket adapts an inhibitor has been less explored experimentally. In this work, we have investigated how the intrinsic flexible regions of the N-terminal domain of MdmX (N-MdmX) affect the affinity of the Mdm2 inhibitor nutlin-3a using protein engineering. Guided by heteronuclear nuclear Overhauser effect measurements, we identified the flexible regions that affect inhibitor binding affinity around the ligand-binding pocket on N-MdmX. A disulfide engineering mutant, N-MdmX C25-C110/C76-C88 , which incorporated two staples to rigidify the ligand-binding pocket, allowed an affinity for nutlin-3a higher than that of wild-type N-MdmX (K d ∼ 0.48 vs K d ∼ 20.3 μM). Therefore, this mutant provides not only an effective protein model for screening and designing of MdmX inhibitors but also a valuable clue for enhancing the intermolecular interactions of the pharmacophores of a ligand with pronounced flexible regions. In addition, our results revealed an allosteric ligand-binding mechanism of N-MdmX in which the ligand initially interacts with a compact core, followed by augmenting intermolecular interactions with intrinsic flexible regions. This strategy should also be applicable to many other protein targets to accelerate drug discovery.

Nandrolone, an anabolic steroid, stabilizes Numb protein through inhibition of mdm2 in C2C12 myoblasts.

PubMed

Liu, Xin-Hua; Yao, Shen; Levine, Alice C; Kirschenbaum, Alexander; Pan, Jiangping; Wu, Yong; Qin, Weiping; Collier, Lauren; Bauman, William A; Cardozo, Christopher P

2012-01-01

Nandrolone, an anabolic steroid, slows denervation atrophy of rat muscle, prevents denervation-induced nuclear accumulation of intracellular domain of the Notch receptor, and elevates expression of Numb. Numb acts as an inhibitor of Notch signaling and promotes myogenic differentiation of satellite cells. Turnover of Numb is regulated by mdm2, an E3 ubiquitin ligase. With these considerations in mind, we investigated the effects of nandrolone on the expression of Numb and mdm2 proteins and determined the effect of mdm2 on nandrolone-induced alterations in Numb protein in C2C12 myoblasts. When C2C12 cells were cultured in a medium favoring differentiation (Dulbecco modified Eagle medium containing 2% horse serum), nandrolone up-regulated Numb protein levels in a time-dependent manner and prolonged Numb protein half-life from 10 to 18 hours. In contrast, nandrolone reduced the expression of mdm2 protein. To determine whether the decreased mdm2 expression induced by nandrolone was responsible for the increased levels and prolonged half-life of Numb protein in this cell line, mdm2-small interfering RNA (siRNA) was employed to inhibit mdm2 expression. Compared to cells transfected with scrambled siRNA (negative control), transfection with mdm2-siRNA increased basal Numb protein expression but abolished the further increase in Numb protein levels by nandrolone. In addition, transfection of mdm2-siRNA mimicked the effect of nandrolone to prolong the half-life of Numb protein. Moreover, when C2C12 cells were forced to overexpress mdm2, there was a significant decline in the expression of both basal and inducible Numb protein. Our data suggest that nandrolone, by a novel mechanism for this agent in a muscle cell type, increases Numb protein levels in C2C12 myoblasts by stabilizing Numb protein against degradation, at least in part, via suppression of mdm2 expression.

Expression screening using a Medaka cDNA library identifies evolutionarily conserved regulators of the p53/Mdm2 pathway.

PubMed

Zhang, Ping; Kratz, Anne Sophie; Salama, Mohammed; Elabd, Seham; Heinrich, Thorsten; Wittbrodt, Joachim; Blattner, Christine; Davidson, Gary

2015-10-08

The p53 tumor suppressor protein is mainly regulated by alterations in the half-life of the protein, resulting in significant differences in p53 protein levels in cells. The major regulator of this process is Mdm2, which ubiquitinates p53 and targets it for proteasomal degradation. This process can be enhanced or reduced by proteins that associate with p53 or Mdm2 and several proteins have been identified with such an activity. Furthermore, additional ubiquitin ligases for p53 have been identified in recent years. Nevertheless, our understanding of how p53 abundance and Mdm2 activity are regulated remains incomplete. Here we describe a cell culture based overexpression screen to identify evolutionarily conserved regulators of the p53/Mdm2 circuit. The results from this large-scale screening method will contribute to a better understanding of the regulation of these important proteins. Expression screening was based on co-transfection of H1299 cells with pools of cDNA's from a Medaka library together with p53, Mdm2 and, as internal control, Ror2. After cell lysis, SDS-PAGE/WB analysis was used to detect alterations in these proteins. More than one hundred hits that altered the abundance of either p53, Mdm2, or both were identified in the primary screen. Subscreening of the library pools that were identified in the primary screen identified several potential novel regulators of p53 and/or Mdm2. We also tested whether the human orthologues of the Medaka genes regulate p53 and/or Mdm2 abundance. All human orthologues regulated p53 and/or Mdm2 abundance in the same manner as the proteins from Medaka, which underscores the suitability of this screening methodology for the identification of new modifiers of p53 and Mdm2. Despite enormous efforts in the last two decades, many unknown regulators for p53 and Mdm2 abundance are predicted to exist. This cross-species approach to identify evolutionarily conserved regulators demonstrates that our Medaka unigene cDNA library represents a powerful tool to screen for these novel regulators of the p53/Mdm2 pathway.

Assessing Language Needs Within an Institutional Context: An Ethnographic Approach.

ERIC Educational Resources Information Center

Holliday, Adrian

1995-01-01

This article describes an analysis of English-language needs of an oil company in the Middle East, exploring the role of ethnography in carrying out the holistic research necessary to obtain a clear picture of the company's needs. It includes a discussion of the project's findings and recommendations for language training. (11 references) (MDM)

Embedded Clause Effects on Recall: Does High Prior Knowledge of Content Domain Overcome Syntactic Complexity in Students of Spanish?

ERIC Educational Resources Information Center

Barry, Sue; Lazarte, Alejandro A.

1995-01-01

This study tested the effect of embedded clauses on recall for 48 English-speaking high school students reading Spanish historical texts. It found that the complexity of sentence structure seemed to cancel the advantage of previous exposure to the content domain. Contains 39 references. (MDM)

Task-Based Interaction and Incidental Vocabulary Learning: A Case Study.

ERIC Educational Resources Information Center

Newton, Jonathan

1995-01-01

This case study examined the vocabulary gains made by an adult learner of English as a Second Language as a result of performing four communication tasks. It found that explicit negotiation of word meaning appeared less deterministic of posttest improvements than use of words in the process of completing the task. (13 references) (MDM)

The Ecological Approach to Language Development: A Radical Solution to Chomsky's and Quine's Problems.

ERIC Educational Resources Information Center

Reed, Edward S.

1995-01-01

Asserts that several of the assumptions underlying Noam Chomsky's and W. V. O. Quine's theories of language acquisition and development are misleading or false. It is argued, among other things, that children do not "acquire" language, but rather learn how to participate in the linguistic community surrounding them. (99 references) (MDM)

A new regulatory pathway of mRNA export by an F-box protein, Mdm30.

PubMed

Durairaj, Geetha; Lahudkar, Shweta; Bhaumik, Sukesh R

2014-02-01

Mdm30, an F-box protein in yeast, has been recently shown to promote mRNA export. However, it remains unknown how Mdm30 facilitates mRNA export. Here, we show that Mdm30 targets the Sub2 component of the TREX (Transcription/Export) complex for ubiquitylation and subsequent proteasomal degradation. Such a targeted degradation of Sub2 enhances the recruitment of the mRNA export adaptor, Yra1, to the active genes to promote mRNA export. Together, these results elucidate that Mdm30 promotes mRNA export by lowering Sub2's stability and consequently enhancing Yra1 recruitment, thus illuminating new regulatory mechanisms of mRNA export by Mdm30.

The Yeast Gene, MDM20, Is Necessary for Mitochondrial Inheritance and Organization of the Actin Cytoskeleton

PubMed Central

Hermann, Greg J.; King, Edward J.; Shaw, Janet M.

1997-01-01

In Saccharomyces cerevisiae, the growing bud inherits a portion of the mitochondrial network from the mother cell soon after it emerges. Although this polarized transport of mitochondria is thought to require functions of the cytoskeleton, there are conflicting reports concerning the nature of the cytoskeletal element involved. Here we report the isolation of a yeast mutant, mdm20, in which both mitochondrial inheritance and actin cables (bundles of actin filaments) are disrupted. The MDM20 gene encodes a 93-kD polypeptide with no homology to other characterized proteins. Extra copies of TPM1, a gene encoding the actin filament–binding protein tropomyosin, suppress mitochondrial inheritance defects and partially restore actin cables in mdm20Δ cells. Synthetic lethality is also observed between mdm20 and tpm1 mutant strains. Overexpression of a second yeast tropomyosin, Tpm2p, rescues mutant phenotypes in the mdm20 strain to a lesser extent. Together, these results provide compelling evidence that mitochondrial inheritance in yeast is an actin-mediated process. MDM20 and TPM1 also exhibit the same pattern of genetic interactions; mutations in MDM20 are synthetically lethal with mutations in BEM2 and MYO2 but not SAC6. Although MDM20 and TPM1 are both required for the formation and/or stabilization of actin cables, mutations in these genes disrupt mitochondrial inheritance and nuclear segregation to different extents. Thus, Mdm20p and Tpm1p may act in vivo to establish molecular and functional heterogeneity of the actin cytoskeleton. PMID:9105043

Structural Exploration and Conformational Transitions in MDM2 upon DHFR Interaction from Homo sapiens: A Computational Outlook for Malignancy via Epigenetic Disruption.

PubMed

Banerjee, Arundhati; Ray, Sujay

2016-01-01

Structural basis for exploration into MDM2 and MDM2-DHFR interaction plays a vital role in analyzing the obstruction in folate metabolism, nonsynthesis of purines, and further epigenetic regulation in Homo sapiens. Therefore, it leads to suppression of normal cellular behavior and malignancy. This has been earlier documented via yeast two-hybrid assays. So, with a novel outlook, this study explores the molecular level demonstration of the best satisfactory MDM2 model selection after performing manifold modeling techniques. Z-scores and other stereochemical features were estimated for comparison. Further, protein-protein docking was executed with MDM2 and the experimentally validated X-ray crystallographic DHFR. Residual disclosure from the best suited simulated protein complex disclosed 18 side chain and 3 ionic interactions to strongly accommodate MDM2 protein into the pocket-like zone in DHFR due to the positive environment by charged residues. Lysine residues from MDM2 played a predominant role. Moreover, evaluation from varied energy calculations, folding rate, and net area for solvent accessibility implied the active participation of MDM2 with DHFR. Fascinatingly, conformational transitions from coils to helices and β-sheets after interaction with DHFR affirm the conformational strength and firmer interaction of human MDM2-DHFR. Therefore, this probe instigates near-future clinical research and interactive computational investigations with mutations.

Structural Exploration and Conformational Transitions in MDM2 upon DHFR Interaction from Homo sapiens: A Computational Outlook for Malignancy via Epigenetic Disruption

PubMed Central

Banerjee, Arundhati; Ray, Sujay

2016-01-01

Structural basis for exploration into MDM2 and MDM2-DHFR interaction plays a vital role in analyzing the obstruction in folate metabolism, nonsynthesis of purines, and further epigenetic regulation in Homo sapiens. Therefore, it leads to suppression of normal cellular behavior and malignancy. This has been earlier documented via yeast two-hybrid assays. So, with a novel outlook, this study explores the molecular level demonstration of the best satisfactory MDM2 model selection after performing manifold modeling techniques. Z-scores and other stereochemical features were estimated for comparison. Further, protein-protein docking was executed with MDM2 and the experimentally validated X-ray crystallographic DHFR. Residual disclosure from the best suited simulated protein complex disclosed 18 side chain and 3 ionic interactions to strongly accommodate MDM2 protein into the pocket-like zone in DHFR due to the positive environment by charged residues. Lysine residues from MDM2 played a predominant role. Moreover, evaluation from varied energy calculations, folding rate, and net area for solvent accessibility implied the active participation of MDM2 with DHFR. Fascinatingly, conformational transitions from coils to helices and β-sheets after interaction with DHFR affirm the conformational strength and firmer interaction of human MDM2-DHFR. Therefore, this probe instigates near-future clinical research and interactive computational investigations with mutations. PMID:27213086

The p53–Mdm2 feedback loop protects against DNA damage by inhibiting p53 activity but is dispensable for p53 stability, development, and longevity

PubMed Central

Pant, Vinod; Xiong, Shunbin; Jackson, James G.; Post, Sean M.; Abbas, Hussein A.; Quintás-Cardama, Alfonso; Hamir, Amirali N.; Lozano, Guillermina

2013-01-01

The p53–Mdm2 feedback loop is perceived to be critical for regulating stress-induced p53 activity and levels. However, this has never been tested in vivo. Using a genetically engineered mouse with mutated p53 response elements in the Mdm2 P2 promoter, we show that feedback loop-deficient Mdm2P2/P2 mice are viable and aphenotypic and age normally. p53 degradation kinetics after DNA damage in radiosensitive tissues remains similar to wild-type controls. Nonetheless, DNA damage response is elevated in Mdm2P2/P2 mice. Enhanced p53-dependent apoptosis sensitizes hematopoietic stem cells (HSCs), causing drastic myeloablation and lethality. These results suggest that while basal Mdm2 levels are sufficient to regulate p53 in most tissues under homeostatic conditions, the p53–Mdm2 feedback loop is critical for regulating p53 activity and sustaining HSC function after DNA damage. Therefore, transient disruption of p53–Mdm2 interaction could be explored as a potential adjuvant/therapeutic strategy for targeting stem cells in hematological malignancies. PMID:23973961

The organization and expression of the mdm2 gene.

PubMed

de Oca Luna, R M; Tabor, A D; Eberspaecher, H; Hulboy, D L; Worth, L L; Colman, M S; Finlay, C A; Lozano, G

1996-05-01

The mdm2 gene encodes a zinc finger protein that negatively regulates p53 function by binding and masking the p53 transcriptional activation domain. Two different promoters control expression of mdm2, one of which is also transactivated by p53. We cloned and characterized the mdm2 gene from a murine 129 library. It contained at least 12 exons and spanned approximately 25 kb of DNA. Sequencing of the mdm2 gene revealed three nucleotide differences that resulted in amino acid substitutions in the previously published mdm2 sequence. Sequencing of normal BalbC/J DNA and the original cosmid clone isolated from the 3T3DM cell line revealed that they are identical, suggesting that the published sequence is in error at these three positions. In addition, we analyzed the expression pattern of mdm2 and found ubiquitous low-level expression throughout embryo development and in adult tissues. Analysis of mRNA from numerous tissues for several mdm2 spliced variants that had been identified in the transformed 3T3DM cell line revealed that these variants could not be detected in the developing embryo or in adult tissues.

MDM2 Associates with Polycomb Repressor Complex 2 and Enhances Stemness-Promoting Chromatin Modifications Independent of p53.

PubMed

Wienken, Magdalena; Dickmanns, Antje; Nemajerova, Alice; Kramer, Daniela; Najafova, Zeynab; Weiss, Miriam; Karpiuk, Oleksandra; Kassem, Moustapha; Zhang, Yanping; Lozano, Guillermina; Johnsen, Steven A; Moll, Ute M; Zhang, Xin; Dobbelstein, Matthias

2016-01-07

The MDM2 oncoprotein ubiquitinates and antagonizes p53 but may also carry out p53-independent functions. Here we report that MDM2 is required for the efficient generation of induced pluripotent stem cells (iPSCs) from murine embryonic fibroblasts, in the absence of p53. Similarly, MDM2 depletion in the context of p53 deficiency also promoted the differentiation of human mesenchymal stem cells and diminished clonogenic survival of cancer cells. Most of the MDM2-controlled genes also responded to the inactivation of the Polycomb Repressor Complex 2 (PRC2) and its catalytic component EZH2. MDM2 physically associated with EZH2 on chromatin, enhancing the trimethylation of histone 3 at lysine 27 and the ubiquitination of histone 2A at lysine 119 (H2AK119) at its target genes. Removing MDM2 simultaneously with the H2AK119 E3 ligase Ring1B/RNF2 further induced these genes and synthetically arrested cell proliferation. In conclusion, MDM2 supports the Polycomb-mediated repression of lineage-specific genes, independent of p53. Copyright © 2016 Elsevier Inc. All rights reserved.

Osteoblast differentiation and skeletal development are regulated by Mdm2–p53 signaling

PubMed Central

Lengner, Christopher J.; Steinman, Heather A.; Gagnon, James; Smith, Thomas W.; Henderson, Janet E.; Kream, Barbara E.; Stein, Gary S.; Lian, Jane B.; Jones, Stephen N.

2006-01-01

Mdm2 is required to negatively regulate p53 activity at the peri-implantation stage of early mouse development. However, the absolute requirement for Mdm2 throughout embryogenesis and in organogenesis is unknown. To explore Mdm2–p53 signaling in osteogenesis, Mdm2-conditional mice were bred with Col3.6-Cre–transgenic mice that express Cre recombinase in osteoblast lineage cells. Mdm2-conditional Col3.6-Cre mice die at birth and display multiple skeletal defects. Osteoblast progenitor cells deleted for Mdm2 have elevated p53 activity, reduced proliferation, reduced levels of the master osteoblast transcriptional regulator Runx2, and reduced differentiation. In contrast, p53-null osteoprogenitor cells have increased proliferation, increased expression of Runx2, increased osteoblast maturation, and increased tumorigenic potential, as mice specifically deleted for p53 in osteoblasts develop osteosarcomas. These results demonstrate that p53 plays a critical role in bone organogenesis and homeostasis by negatively regulating bone development and growth and by suppressing bone neoplasia and that Mdm2-mediated inhibition of p53 function is a prerequisite for Runx2 activation, osteoblast differentiation, and proper skeletal formation. PMID:16533949

MDM2 antagonists synergize broadly and robustly with compounds targeting fundamental oncogenic signaling pathways

PubMed Central

Yu, Dongyin; Lofgren, Julie A.; Osgood, Tao; Robertson, Rebecca; Canon, Jude; Su, Cheng; Jones, Adrie; Zhao, Xiaoning; Deshpande, Chetan; Payton, Marc; Ledell, Jebediah; Hughes, Paul E.; Oliner, Jonathan D.

2014-01-01

While MDM2 inhibitors hold great promise as cancer therapeutics, drug resistance will likely limit their efficacy as single agents. To identify drug combinations that might circumvent resistance, we screened for agents that could synergize with MDM2 inhibition in the suppression of cell viability. We observed broad and robust synergy when combining MDM2 antagonists with either MEK or PI3K inhibitors. Synergy was not limited to cell lines harboring MAPK or PI3K pathway mutations, nor did it depend on which node of the PI3K axis was targeted. MDM2 inhibitors also synergized strongly with BH3 mimetics, BCR-ABL antagonists, and HDAC inhibitors. MDM2 inhibitor-mediated synergy with agents targeting these mechanisms was much more prevalent than previously appreciated, implying that clinical translation of these combinations could have far-reaching implications for public health. These findings highlight the importance of combinatorial drug targeting and provide a framework for the rational design of MDM2 inhibitor clinical trials. PMID:24810962

Domain analysis of Ras-association domain family member 6 upon interaction with MDM2.

PubMed

Sarkar, Aradhan; Iwasa, Hiroaki; Hossain, Shakhawoat; Xu, Xiaoyin; Sawada, Takeru; Shimizu, Takanobu; Maruyama, Junichi; Arimoto-Matsuzaki, Kyoko; Hata, Yutaka

2017-01-01

The tumor suppressor Ras-association domain family member 6 (RASSF6) has Ras-association domain (RA) and Salvador/RASSF/Hippo domain (SARAH). RASSF6 antagonizes MDM2, stabilizes p53, and induces apoptosis and cell cycle arrest. We previously demonstrated the interaction between RASSF6 and MDM2, but did not determine how both proteins interact with each other. We have shown here that N-terminal, RA, and SARAH domains of RASSF6 interact with MDM2 at distinct regions. RA binds to the RING-finger region of MDM2 and stabilizes p53. SARAH binds RA and blocks the interaction between RA and MDM2. RA overexpression induces p53-dependent apoptosis and senescence. In the presence of active KRas, the interaction between RA and MDM2 is recovered. In this way, RA and SARAH play an important role in Ras-mediated regulation of p53. © 2017 Federation of European Biochemical Societies.

New Developments in Magnetostatic Cleanliness Modeling

NASA Astrophysics Data System (ADS)

Mehlem, K.; Wiegand, A.; Weickert, S.

2012-05-01

The paper describes improvements and extensions of the multiple magnetic dipole modeling method (MDM) for cleanliness verification which had been introduced by the author1 in 1977 and then applied during 3 decades to numerous international projects. The solutions of specific modeling problems which had been left unsolved so far, are described in the present paper. Special attention is given to the ambiguities of MDM solutions caused by the limited data coverage available. Constraint handling by the constraint-free NLP solver, optimal MDM sizing and multiple-point far-field compensation techniques are presented. The recent extension of the MDM method to field gradient data is formulated and demonstrated by an example. Finally, a complex MDM application (Ulysses) is presented. Finally, a short description of the MDM software GAMAG, recently introduced by the author1, is given.

Plant Nucleolar Stress Response, a New Face in the NAC-Dependent Cellular Stress Responses.

PubMed

Ohbayashi, Iwai; Sugiyama, Munetaka

2017-01-01

The nucleolus is the most prominent nuclear domain, where the core processes of ribosome biogenesis occur vigorously. All these processes are finely orchestrated by many nucleolar factors to build precisely ribosome particles. In animal cells, perturbations of ribosome biogenesis, mostly accompanied by structural disorders of the nucleolus, cause a kind of cellular stress to induce cell cycle arrest, senescence, or apoptosis, which is called nucleolar stress response. The best-characterized pathway of this stress response involves p53 and MDM2 as key players. p53 is a crucial transcription factor that functions in response to not only nucleolar stress but also other cellular stresses such as DNA damage stress. These cellular stresses release p53 from the inhibition by MDM2, an E3 ubiquitin ligase targeting p53, in various ways, which leads to p53-dependent activation of a set of genes. In plants, genetic impairments of ribosome biogenesis factors or ribosome components have been shown to cause characteristic phenotypes, including a narrow and pointed leaf shape, implying a common signaling pathway connecting ribosomal perturbations and certain aspects of growth and development. Unlike animals, however, plants have neither p53 nor MDM2 family proteins. Then the question arises whether plant cells have a nucleolar stress response pathway. In recent years, it has been reported that several members of the plant-specific transcription factor family NAC play critical roles in the pathways responsive to various cellular stresses. In this mini review, we outline the plant cellular stress response pathways involving NAC transcription factors with reference to the p53-MDM2-dependent pathways of animal cells, and discuss the possible involvement of a plant-unique, NAC-mediated pathway in the nucleolar stress response in plants.

On the interaction mechanisms of a p53 peptide and nutlin with the MDM2 and MDMX proteins: a Brownian dynamics study.

PubMed

ElSawy, Karim M; Verma, Chandra S; Joseph, Thomas L; Lane, David P; Twarock, Reidun; Caves, Leo S D

2013-02-01

The interaction of p53 with its regulators MDM2 and MDMX plays a major role in regulating the cell cycle. Inhibition of this interaction has become an important therapeutic strategy in oncology. Although MDM2 and MDMX share a very high degree of sequence/structural similarity, the small-molecule inhibitor nutlin appears to be an efficient inhibitor only of the p53-MDM2 interaction. Here, we investigate the mechanism of interaction of nutlin with these two proteins and contrast it with that of p53 using Brownian dynamics simulations. In contrast to earlier attempts to examine the bound states of the partners, here we locate initial reaction events in these interactions by identifying the regions of space around MDM2/MDMX, where p53/nutlin experience associative encounters with prolonged residence times relative to that in bulk solution. We find that the initial interaction of p53 with MDM2 is long-lived relative to nutlin, but, unlike nutlin, it takes place at the N- and C termini of the MDM2 protein, away from the binding site, suggestive of an allosteric mechanism of action. In contrast, nutlin initially interacts with MDM2 directly at the clefts of the binding site. The interaction of nutlin with MDMX, however, is very short-lived compared with MDM2 and does not show such direct initial interactions with the binding site. Comparison of the topology of the electrostatic potentials of MDM2 and MDMX and the locations of the initial encounters with p53/nutlin in tandem with structure-based sequence alignment revealed that the origin of the diminished activity of nutlin toward MDMX relative to MDM2 may stem partly from the differing topologies of the electrostatic potentials of the two proteins. Glu25 and Lys51 residues underpin these topological differences and appear to collectively play a key role in channelling nutlin directly toward the binding site on the MDM2 surface and are absent in MDMX. The results, therefore, provide new insight into the mechanism of p53/nutlin interactions with MDM2 and MDMX and could potentially have a broader impact on anticancer drug optimization strategies.

Identification of antipsychotic drug fluspirilene as a potential p53-MDM2 inhibitor: a combined computational and experimental study

NASA Astrophysics Data System (ADS)

Patil, Sachin P.; Pacitti, Michael F.; Gilroy, Kevin S.; Ruggiero, John C.; Griffin, Jonathan D.; Butera, Joseph J.; Notarfrancesco, Joseph M.; Tran, Shawn; Stoddart, John W.

2015-02-01

The inhibition of tumor suppressor p53 protein due to its direct interaction with oncogenic murine double minute 2 (MDM2) protein, plays a central role in almost 50 % of all human tumor cells. Therefore, pharmacological inhibition of the p53-binding pocket on MDM2, leading to p53 activation, presents an important therapeutic target against these cancers expressing wild-type p53. In this context, the present study utilized an integrated virtual and experimental screening approach to screen a database of approved drugs for potential p53-MDM2 interaction inhibitors. Specifically, using an ensemble rigid-receptor docking approach with four MDM2 protein crystal structures, six drug molecules were identified as possible p53-MDM2 inhibitors. These drug molecules were then subjected to further molecular modeling investigation through flexible-receptor docking followed by Prime/MM-GBSA binding energy analysis. These studies identified fluspirilene, an approved antipsychotic drug, as a top hit with MDM2 binding mode and energy similar to that of a native MDM2 crystal ligand. The molecular dynamics simulations suggested stable binding of fluspirilene to the p53-binding pocket on MDM2 protein. The experimental testing of fluspirilene showed significant growth inhibition of human colon tumor cells in a p53-dependent manner. Fluspirilene also inhibited growth of several other human tumor cell lines in the NCI60 cell line panel. Taken together, these computational and experimental data suggest a potentially novel role of fluspirilene in inhibiting the p53-MDM2 interaction. It is noteworthy here that fluspirilene has a long history of safe human use, thus presenting immediate clinical potential as a cancer therapeutic. Furthermore, fluspirilene could also serve as a structurally-novel lead molecule for the development of more potent, small-molecule p53-MDM2 inhibitors against several types of cancer. Importantly, the combined computational and experimental screening protocol presented in this study may also prove useful for screening other commercially-available compound databases for identification of novel, small molecule p53-MDM2 inhibitors.

Mdm2 overexpression and p14(ARF) inactivation are two mutually exclusive events in primary human lung tumors.

PubMed

Eymin, Béatrice; Gazzeri, Sylvie; Brambilla, Christian; Brambilla, Elisabeth

2002-04-18

Pathways involving p53 and pRb tumor suppressor genes are frequently deregulated during lung carcinogenesis. Through its location at the interface of these pathways, Mdm2 can modulate the function of both p53 and pRb genes. We have examined here the pattern of expression of Mdm2 in a series of 192 human lung carcinomas of all histological types using both immunohistochemical and Western blot analyses and four distinct antibodies mapping different epitopes onto the Mdm2 protein. Using Immunohistochemistry (IHC), Mdm2 was overexpressed as compared to normal lung in 31% (60 out of 192) of all tumors analysed, whatever their histological types. Western blotting was performed on 28 out of the 192 tumoral samples. Overexpression of p85/90, p74/76 and p57 Mdm2 isoforms was detected in 18% (5 out of 28), 25% (7 out of 28) and 39% (11 out of 28) of the cases respectively. Overall, overexpression of at least one isoform was observed in 14 out of 28 (50%) lung tumors and concomittant overexpression of at least two isoforms in 7 out of 28 (25%) cases. A good concordance (82%) was observed between immunohistochemical and Western blot data. Interestingly, a highly significant inverse relationship was detected between p14(ARF) loss and Mdm2 overexpression either in NSCLC (P=0.0089) or in NE lung tumors (P<0.0001). Furthermore, a Mdm2/p14(ARF) >1 ratio was correlated with a high grade phenotype among NE tumors overexpressing Mdm2 (P=0.0021). Taken together, these data strongly suggest that p14(ARF)and Mdm2 act on common pathway(s) to regulate p53 and/or pRb-dependent or independent functions and that the Mdm2 : p14(ARF) ratio might act as a rheostat in modulating the activity of both proteins.

MDM2 is an important prognostic and predictive factor for platin-pemetrexed therapy in malignant pleural mesotheliomas and deregulation of P14/ARF (encoded by CDKN2A) seems to contribute to an MDM2-driven inactivation of P53.

PubMed

Walter, R F H; Mairinger, F D; Ting, S; Vollbrecht, C; Mairinger, T; Theegarten, D; Christoph, D C; Schmid, K W; Wohlschlaeger, J

2015-03-03

Malignant pleural mesothelioma (MPM) is a highly aggressive tumour that is first-line treated with a combination of cisplatin and pemetrexed. Until now, predictive and prognostic biomarkers are lacking, making it a non-tailored therapy regimen with unknown outcome. P53 is frequently inactivated in MPM, but mutations are extremely rare. MDM2 and P14/ARF are upstream regulators of P53 that may contribute to P53 inactivation. A total of 72 MPM patients were investigated. MDM2 immunoexpression was assessed in 65 patients. MDM2 and P14/ARF mRNA expression was analysed in 48 patients of the overall collective. The expression results were correlated to overall survival (OS) and progression-free survival (PFS). OS and PFS correlated highly significantly with MDM2 mRNA and protein expression, showing a dismal prognosis for patients with elevated MDM2 expression (for OS: Score (logrank) test: P⩽0.002, and for PFS: Score (logrank) test; P<0.007). MDM2 was identified as robust prognostic and predictive biomarker for MPM on the mRNA and protein level. P14/ARF mRNA expression reached no statistical significance, but Kaplan-Meier curves distinguished patients with low P14/ARF expression and hence shorter survival from patients with higher expression and prolonged survival. MDM2 is a prognostic and predictive marker for a platin-pemetrexed therapy of patients with MPMs. Downregulation of P14/ARF expression seems to contribute to MDM2-overexpression-mediated P53 inactivation in MPM patients.

A Small-molecule Inhibitor, 5′-O-Tritylthymidine, targets FAK and Mdm-2 Interaction, and Blocks Breast and Colon Tumorigenesis in vivo

PubMed Central

Golubovskaya, Vita; Palma, Nadia L.; Zheng, Min; Ho, Baotran; Magis, Andrew; Ostrov, David; Cance, William G.

2013-01-01

Focal Adhesion Kinase (FAK) is overexpressed in many types of tumors and plays an important role in survival. We developed a novel approach, targeting FAK-protein interactions by computer modeling and screening of NCI small molecule drug database. In this report we targeted FAK and Mdm-2 protein interaction to decrease tumor growth. By macromolecular modeling we found a model of FAK and Mdm-2 interaction and performed screening of >200,000 small molecule compounds from NCI database with drug-like characteristics, targeting the FAK-Mdm-2 interaction. We identified 5′-O-Tritylthymidine, called M13 compound that significantly decreased viability in different cancer cells. M13 was docked into the pocket of FAK and Mdm-2 interaction and was directly bound to the FAK-N terminal domain by ForteBio Octet assay. In addition, M13 compound affected FAK and Mdm-2 levels and decreased complex of FAK and Mdm-2 proteins in breast and colon cancer cells. M13 re-activated p53 activity inhibited by FAK with Mdm-2 promoter. M13 decreased viability, clonogenicity, increased detachment and apoptosis in a dose-dependent manner in BT474 breast and in HCT116 colon cancer cells in vitro. M13 decreased FAK, activated p53 and caspase-8 in both cell lines. In addition, M13 decreased breast and colon tumor growth in vivo. M13 activated p53 and decreased FAK in tumor samples consistent with decreased tumor growth. The data demonstrate a novel approach for targeting FAK and Mdm-2 protein interaction, provide a model of FAK and Mdm-2 interaction, identify M13 compound targeting this interaction and decreasing tumor growth that is critical for future targeted therapeutics. PMID:22292771

Strategic L2 Lexical Innovation: Case Study of a University-Level Ab Initio Learner of German.

ERIC Educational Resources Information Center

Ridley, Jennifer; Singleton, David

1995-01-01

This article presents a case study of one English-speaking ab initio learner of German. It found that in target language production tasks performed over a two-year period, the subject exhibited a particular tendency toward lexical innovation as a strategy to cope with the lack of target language lexical knowledge. (38 references) (MDM)

DOE Office of Scientific and Technical Information (OSTI.GOV)

AhYoung, Andrew P.; Lu, Brian; Cascio, Duilio

Membrane contact sites between organelles serve as molecular hubs for the exchange of metabolites and signals. In yeast, the Endoplasmic Reticulum – Mitochondrion Encounter Structure (ERMES) tethers these two organelles likely to facilitate the non-vesicular exchange of essential phospholipids. Present in Fungi and Amoebas but not in Metazoans, ERMES is composed of five distinct subunits; among those, Mdm12, Mmm1 and Mdm34 each contain an SMP domain functioning as a lipid transfer module. We previously showed that the SMP domains of Mdm12 and Mmm1 form a hetero-tetramer. Here we describe our strategy to diversify the number of Mdm12/Mmm1 complexes suited formore » structural studies. We use sequence analysis of orthologues combined to protein engineering of disordered regions to guide the design of protein constructs and expand the repertoire of Mdm12/Mmm1 complexes more likely to crystallize. Using this combinatorial approach we report crystals of Mdm12/Mmm1 ERMES complexes currently diffracting to 4.5 Å resolution and a new structure of Mdm12 solved at 4.1 Å resolution. Our structure reveals a monomeric form of Mdm12 with a conformationally dynamic N-terminal β-strand; it differs from a previously reported homodimeric structure where the N-terminal β strands where swapped to promote dimerization. Based on our electron microscopy data, we propose a refined pseudo-atomic model of the Mdm12/Mmm1 complex that agrees with our crystallographic and small-angle X-ray scattering (SAXS) solution data.« less

Challenging dedifferentiated liposarcoma identified by MDM2-amplification, a report of two cases.

PubMed

Lokka, Suvi; Scheel, Andreas H; Dango, Sebastian; Schmitz, Katja; Hesterberg, Rudolf; Rüschoff, Josef; Schildhaus, Hans-Ulrich

2014-01-01

Liposarcoma is the most frequent soft tissue sarcoma. Well differentiated liposarcoma may progress into dedifferentiated liposarcoma with pleomorphic histology. A minority additionally features myogenic, osteo- or chondrosarcomatous heterologous differentiation. Genomic amplification of the Mouse double minute 2 homolog (MDM2) locus is characteristic for well differentiated and dedifferentiated liposarcomas. Detection of MDM2 amplification may supplement histopathology and aid to distinguish liposarcoma from other soft tissue neoplasia. Here we present two cases of dedifferentiated liposarcoma with challenging presentation. Case 1 features a myogenic component. As the tumour infiltrated the abdominal muscles and showed immunohistochemical expression of myogenic proteins, rhabdomyosarcoma had to be ruled out. Case 2 has an osteosarcomatous component resembling extraosseous osteosarcoma. The MDM2 status was determined in both cases and helped making the correct diagnosis. Overexpression of MDM2 and co-overexpression of Cyclin-dependent kinase 4 is demonstrated by immunohistochemistry. The underlying MDM2 amplification is shown by fluorescence in situ hybridisation. Since low grade osteosarcoma may also harbour MDM2 amplification it is emphasised that the amplification has to be present in the lipomatous parts of the tumour to distinguish liposarcoma from extraosseous osteosarcoma. The two cases exemplify challenges in the diagnoses of dedifferentiated liposarcoma. Liposarcoma often has pleomorphic histology and additionally may feature heterologous components that mimic other soft tissue neoplasms. Amplification of MDM2 is characteristic for well differentiated and dedifferentiated liposarcomas. Determination of the MDM2 status by in situ hybridisation may assist histopathology and help to rule out differential diagnoses.

Comparison between retroperitoneal leiomyosarcoma and dedifferentiated liposarcoma.

PubMed

Ishii, Takeaki; Kohashi, Kenichi; Ootsuka, Hiroshi; Iura, Kunio; Maekawa, Akira; Yamada, Yuichi; Bekki, Hirofumi; Yoshimoto, Masato; Yamamoto, Hidetaka; Iwamoto, Yukihide; Oda, Yoshinao

2017-06-01

It is important to distinguish between leiomyosarcoma (LMS) and dedifferentiated liposarcoma (DDLS) in the retroperitoneum. The dedifferentiated component of DDLS shows an LMS-like morphology in some cases; thus, detailed evaluation is necessary to achieve an accurate diagnosis. Immunohistochemically, MDM2 and myogenic markers provide clues for the diagnoses. However, immunoreactivity for MDM2 and myogenic markers has not been well studied in retroperitoneal LMS and DDLS. Here, we compared the clinicopathological data of 20 retroperitoneal tumors initially diagnosed as LMS with that of 36 cases of retroperitoneal DDLS and conducted an immunohistochemical study. Four (20%) of the cases initially diagnosed as LMS were immunoreactive for MDM2. Fifteen cases (41.7%) of DDLS showed positive expression of two or more myogenic markers. The patients with LMS with MDM2 overexpression were older than the patients with LMS without MDM2 overexpression (P=0.0328). LMS with MDM2 overexpression showed a worse prognosis than DDLS (P=0.0408). No significant difference in prognosis was found between LMS without MDM2 overexpression and DDLS with myogenic differentiation. In conclusion, we recommend that systemic MDM2 expression analysis be performed in cases of retroperitoneal sarcoma. Overdependence on the expression of myogenic markers could lead to misdiagnosis in distinguishing LMS from DDLS. Copyright © 2017 Elsevier GmbH. All rights reserved.

Smad Ubiquitylation Regulatory Factor 1/2 (Smurf1/2) Promotes p53 Degradation by Stabilizing the E3 Ligase MDM2*

PubMed Central

Nie, Jing; Xie, Ping; Liu, Lin; Xing, Guichun; Chang, Zhijie; Yin, Yuxin; Tian, Chunyan; He, Fuchu; Zhang, Lingqiang

2010-01-01

The tumor suppressor p53 protein is tightly regulated by a ubiquitin-proteasomal degradation mechanism. Several E3 ubiquitin ligases, including MDM2 (mouse double minute 2), have been reported to play an essential role in the regulation of p53 stability. However, it remains unclear how the activity of these E3 ligases is regulated. Here, we show that the HECT-type E3 ligase Smurf1/2 (Smad ubiquitylation regulatory factor 1/2) promotes p53 degradation by enhancing the activity of the E3 ligase MDM2. We provide evidence that the role of Smurf1/2 on the p53 stability is not dependent on the E3 activity of Smurf1/2 but rather is dependent on the activity of MDM2. We find that Smurf1/2 stabilizes MDM2 by enhancing the heterodimerization of MDM2 with MDMX, during which Smurf1/2 interacts with MDM2 and MDMX. We finally provide evidence that Smurf1/2 regulates apoptosis through p53. To our knowledge, this is the first report to demonstrate that Smurf1/2 functions as a factor to stabilize MDM2 protein rather than as a direct E3 ligase in regulation of p53 degradation. PMID:20484049

Functional characterization of p53 pathway components in the ancient metazoan Trichoplax adhaerens

NASA Astrophysics Data System (ADS)

Siau, Jia Wei; Coffill, Cynthia R.; Zhang, Weiyun Villien; Tan, Yaw Sing; Hundt, Juliane; Lane, David; Verma, Chandra; Ghadessy, Farid

2016-09-01

The identification of genes encoding a p53 family member and an Mdm2 ortholog in the ancient placozoan Trichoplax adhaerens advocates for the evolutionary conservation of a pivotal stress-response pathway observed in all higher eukaryotes. Here, we recapitulate several key functionalities ascribed to this known interacting protein pair by analysis of the placozoan proteins (Tap53 and TaMdm2) using both in vitro and cellular assays. In addition to interacting with each other, the Tap53 and TaMdm2 proteins are also able to respectively bind human Mdm2 and p53, providing strong evidence for functional conservation. The key p53-degrading function of Mdm2 is also conserved in TaMdm2. Tap53 retained DNA binding associated with p53 transcription activation function. However, it lacked transactivation function in reporter genes assays using a heterologous cell line, suggesting a cofactor incompatibility. Overall, the data supports functional roles for TaMdm2 and Tap53, and further defines the p53 pathway as an evolutionary conserved fulcrum mediating cellular response to stress.

Mdm2 is required for survival of hematopoietic stem cells/progenitors via dampening of ROS-induced p53 activity

USDA-ARS?s Scientific Manuscript database

Mdm2 is an E3 ubiquitin ligase that targets p53 for degradation. p53(515C) (encoding p53R172P) is a hypomorphic allele of p53 that rescues the embryonic lethality of Mdm2(-/-) mice. Mdm2(-/-) p53(515C/515C) mice, however, die by postnatal day 13 resulting from hematopoietic failure. Hematopoietic st...

The oncoprotein gankyrin binds to MDM2/HDM2, enhancing ubiquitylation and degradation of p53.

PubMed

Higashitsuji, Hiroaki; Higashitsuji, Hisako; Itoh, Katsuhiko; Sakurai, Toshiharu; Nagao, Toshikazu; Sumitomo, Yasuhiko; Sumitomo, Haruhiko; Masuda, Tomoko; Dawson, Simon; Shimada, Yutaka; Mayer, R John; Fujita, Jun

2005-07-01

Gankyrin is an ankyrin repeat oncoprotein commonly overexpressed in hepatocellular carcinomas. Gankyrin interacts with the S6 proteasomal ATPase and accelerates the degradation of the tumor suppressor Rb. We show here that gankyrin has an antiapoptotic activity in cells exposed to DNA damaging agents. Downregulation of gankyrin induces apoptosis in cells with wild-type p53. In vitro and in vivo experiments revealed that gankyrin binds to Mdm2, facilitating p53-Mdm2 binding, and increases ubiquitylation and degradation of p53. Gankyrin also enhances Mdm2 autoubiquitylation in the absence of p53. Downregulation of gankyrin reduced amounts of Mdm2 and p53 associated with the 26S proteasome. Thus, gankyrin is a cofactor that increases the activities of Mdm2 on p53 and probably targets polyubiquitylated p53 into the 26S proteasome.

Unbalancing p53/Mdm2/IGF-1R axis by Mdm2 activation restrains the IGF-1-dependent invasive phenotype of skin melanoma

PubMed Central

Worrall, C; Suleymanova, N; Crudden, C; Trocoli Drakensjö, I; Candrea, E; Nedelcu, D; Takahashi, S-I; Girnita, L; Girnita, A

2017-01-01

Melanoma tumors usually retain wild-type p53; however, its tumor-suppressor activity is functionally disabled, most commonly through an inactivating interaction with mouse double-minute 2 homolog (Mdm2), indicating p53 release from this complex as a potential therapeutic approach. P53 and the tumor-promoter insulin-like growth factor type 1 receptor (IGF-1R) compete as substrates for the E3 ubiquitin ligase Mdm2, making their relative abundance intricately linked. Hence we investigated the effects of pharmacological Mdm2 release from the Mdm2/p53 complex on the expression and function of the IGF-1R. Nutlin-3 treatment increased IGF-1R/Mdm2 association with enhanced IGF-1R ubiquitination and a dual functional outcome: receptor downregulation and selective downstream signaling activation confined to the mitogen-activated protein kinase/extracellular signal-regulated kinase pathway. This Nutlin-3 functional selectivity translated into IGF-1-mediated bioactivities with biphasic effects on the proliferative and metastatic phenotype: an early increase and late decrease in the number of proliferative and migratory cells, while the invasiveness was completely inhibited following Nutlin-3 treatment through an impaired IGF-1-mediated matrix metalloproteinases type 2 activation mechanism. Taken together, these experiments reveal the biased agonistic properties of Nutlin-3 for the mitogen-activated protein kinase pathway, mediated by Mdm2 through IGF-1R ubiquitination and provide fundamental insights into destabilizing p53/Mdm2/IGF-1R circuitry that could be developed for therapeutic gain. PMID:28092675

Crystal structures of Mmm1 and Mdm12–Mmm1 reveal mechanistic insight into phospholipid trafficking at ER-mitochondria contact sites

PubMed Central

Jeong, Hanbin; Park, Jumi; Jun, Youngsoo; Lee, Changwook

2017-01-01

The endoplasmic reticulum (ER)-mitochondria encounter structure (ERMES) comprises mitochondrial distribution and morphology 12 (Mdm12), maintenance of mitochondrial morphology 1 (Mmm1), Mdm34, and Mdm10 and mediates physical membrane contact sites and nonvesicular lipid trafficking between the ER and mitochondria in yeast. Herein, we report two crystal structures of the synaptotagmin-like mitochondrial lipid-binding protein (SMP) domain of Mmm1 and the Mdm12–Mmm1 complex at 2.8 Å and 3.8 Å resolution, respectively. Mmm1 adopts a dimeric SMP structure augmented with two extra structural elements at the N and C termini that are involved in tight self-association and phospholipid coordination. Mmm1 binds two phospholipids inside the hydrophobic cavity, and the phosphate ion of the distal phospholipid is specifically recognized through extensive H-bonds. A positively charged concave surface on the SMP domain not only mediates ER membrane docking but also results in preferential binding to glycerophospholipids such as phosphatidylcholine (PC), phosphatidic acid (PA), phosphatidylglycerol (PG), and phosphatidylserine (PS), some of which are substrates for lipid-modifying enzymes in mitochondria. The Mdm12–Mmm1 structure reveals two Mdm12s binding to the SMP domains of the Mmm1 dimer in a pairwise head-to-tail manner. Direct association of Mmm1 and Mdm12 generates a 210-Å-long continuous hydrophobic tunnel that facilitates phospholipid transport. The Mdm12–Mmm1 complex binds all glycerophospholipids except for phosphatidylethanolamine (PE) in vitro. PMID:29078410

The Impact of a Common MDM2 SNP on the Sensitivity of Breast Cancer to Treatment

DTIC Science & Technology

2012-06-01

1993; Kussie, 1996 ; Lin, 1994; Freedman, 1999). Apart from its p53 ubiquitination function, MDM2 has other functions including nuclear- cytoplasmic...MDM2; however, it can be degraded by MDM2 (Shvarts, 1997; Shvarts, 1996 ; Okamoto, 2005). Appropriate expression of p53 propels cells down apoptotic...prognostic value for various endpoints in multiple tumor types (Bueso-Ramos, 1996 ; Khor, 2005; Kim, 2011; Marchetti, 1995;Marchetti, 1995; McCann, 1995

Ribosomal protein-Mdm2-p53 pathway coordinates nutrient stress with lipid metabolism by regulating MCD and promoting fatty acid oxidation.

PubMed

Liu, Yong; He, Yizhou; Jin, Aiwen; Tikunov, Andrey P; Zhou, Lishi; Tollini, Laura A; Leslie, Patrick; Kim, Tae-Hyung; Li, Lei O; Coleman, Rosalind A; Gu, Zhennan; Chen, Yong Q; Macdonald, Jeffrey M; Graves, Lee M; Zhang, Yanping

2014-06-10

The tumor suppressor p53 has recently been shown to regulate energy metabolism through multiple mechanisms. However, the in vivo signaling pathways related to p53-mediated metabolic regulation remain largely uncharacterized. By using mice bearing a single amino acid substitution at cysteine residue 305 of mouse double minute 2 (Mdm2(C305F)), which renders Mdm2 deficient in binding ribosomal proteins (RPs) RPL11 and RPL5, we show that the RP-Mdm2-p53 signaling pathway is critical for sensing nutrient deprivation and maintaining liver lipid homeostasis. Although the Mdm2(C305F) mutation does not significantly affect growth and development in mice, this mutation promotes fat accumulation under normal feeding conditions and hepatosteatosis under acute fasting conditions. We show that nutrient deprivation inhibits rRNA biosynthesis, increases RP-Mdm2 interaction, and induces p53-mediated transactivation of malonyl-CoA decarboxylase (MCD), which catalyzes the degradation of malonyl-CoA to acetyl-CoA, thus modulating lipid partitioning. Fasted Mdm2(C305F) mice demonstrate attenuated MCD induction and enhanced malonyl-CoA accumulation in addition to decreased oxidative respiration and increased fatty acid accumulation in the liver. Thus, the RP-Mdm2-p53 pathway appears to function as an endogenous sensor responsible for stimulating fatty acid oxidation in response to nutrient depletion.

Development of a peer-review framework for cancer multidisciplinary meetings.

PubMed

Johnson, Claire E; Slavova-Azmanova, Neli; Saunders, Christobel

2017-05-01

There is no mechanism in place for monitoring or quality improvement of cancer multidisciplinary meetings (MDM) in Australia. To develop a peer-review process for quality improvement of MDM. This project involved three phases: (i) development of a draft peer-review framework, supporting documents and peer-review process; (ii) consultation with key stakeholders; (iii) refinement of the framework, documents and processes following a pilot study with three MDM. Feedback indicated that specific standards included in the framework needed to allow the peer reviewers to be flexible relative to the circumstances of the individual MDM. Conversely, feedback identified the need for clear, evidence-based clinical practice guidelines for the conduct of MDM, with accepted standards and objective measures of performance. MDM members were divided about the need to employ peer reviewers from the tumour stream of the MDM under review but agreed that closer involvement of the team under review to support the implementation of recommendations is warranted. We developed an adaptable peer-review framework and process using the current available evidence and guidance. While further research is needed to establish what constitutes best practice in MDM and which processes contribute to improved patient outcomes, the structured peer-review process we describe, when modified using the disease-relevant evidence, could be utilised more broadly as a quality improvement tool. © 2017 Royal Australasian College of Physicians.

Elucidation of Ligand-Dependent Modulation of Disorder-Order Transitions in the Oncoprotein MDM2.

PubMed

Bueren-Calabuig, Juan A; Michel, Julien

2015-06-01

Numerous biomolecular interactions involve unstructured protein regions, but how to exploit such interactions to enhance the affinity of a lead molecule in the context of rational drug design remains uncertain. Here clarification was sought for cases where interactions of different ligands with the same disordered protein region yield qualitatively different results. Specifically, conformational ensembles for the disordered lid region of the N-terminal domain of the oncoprotein MDM2 in the presence of different ligands were computed by means of a novel combination of accelerated molecular dynamics, umbrella sampling, and variational free energy profile methodologies. The resulting conformational ensembles for MDM2, free and bound to p53 TAD (17-29) peptide identify lid states compatible with previous NMR measurements. Remarkably, the MDM2 lid region is shown to adopt distinct conformational states in the presence of different small-molecule ligands. Detailed analyses of small-molecule bound ensembles reveal that the ca. 25-fold affinity improvement of the piperidinone family of inhibitors for MDM2 constructs that include the full lid correlates with interactions between ligand hydrophobic groups and the C-terminal lid region that is already partially ordered in apo MDM2. By contrast, Nutlin or benzodiazepinedione inhibitors, that bind with similar affinity to full lid and lid-truncated MDM2 constructs, interact additionally through their solubilizing groups with N-terminal lid residues that are more disordered in apo MDM2.

Mouse double minute-2 homolog (MDM2)-rs2279744 polymorphism associated with lung cancer risk in a Northeastern Chinese population.

PubMed

Wang, Xu; Jin, Lina; Cui, Jiuwei; Ma, Kewei; Chen, Xiao; Li, Wei

2015-01-01

Altered expression or function of mouse double minute-2 (MDM2) protein could contribute to lung carcinogenesis; thus, this study investigated MDM2-rs2279744 polymorphism together with other epidemiologic factors for their association with lung cancer risk. A total of 500 lung cancer patients and 500 age and gender-matched healthy controls living in Northeastern China were recruited for genotyping of MDM2-rs2279744. Clinicopathological data was collected and subjected to univariate and multivariate analyses. In univariate analysis, the MDM2-rs2279744 G/G genotype versus T/T + T/G genotypes showed a tendency toward a higher incidence of lung cancer in the recessive model (P = 0.043). However, there were no significant differences when it was analyzed by the dominant, additive, or multiplicative models. A significantly increased lung cancer risk was observed associated with lower education level, lower body mass index, cancer family history, prior diagnosis of chronic obstructive pulmonary disease and pneumonia, exposure to pesticide or gasoline/diesel, tobacco smoking, and heavy cooking emissions when assessed by multivariate analyses. Moreover, MDM2-rs2279744 was still a significant risk factor even after incorporating environmental and lifestyle factors. However, there was no association between MDM2-rs2279744 and other factors. The MDM2-rs2279744 G/G genotype was associated with a higher lung cancer risk, even after incorporating other epidemiologic factors.

99mTc-MDM Brain SPECT for the Detection of Recurrent/Remnant Glioma-Comparison With ceMRI and 18F-FLT PET Imaging: Initial Results.

PubMed

Singh, Baljinder; Kumar, Narendra; Sharma, Sarika; Watts, Ankit; Hazari, Puja P; Rani, Nisha; Vyas, Sameer; Anish, Bhattacharya; Mishra, Anil K

2015-10-01

To evaluate the diagnostic use of an indigenously developed single vial ready to label (with Tc) kit preparation of bis-methionine-DTPA (Tc-MDM) for the detection of recurrent/residual glioma. We prospectively studied 32 patients (21 male and 11 female subjects aged 43.0±16.0 years) with clinical suspicion of postoperative recurrent/residual glioma. After radical radiotherapy (54.0-60.0 Gy) with or without concurrent temozolomide as indicated, Tc-MDM SPECT and ceMRI of the brain was performed in all the patients and F-FLT-PET imaging in 16 of 32 patients. MDM SPECT and ceMRI findings were concordant in 28 patients (15 positive and 13 negative). The findings were discordant in the remaining 5 patients, with positive ceMRI and negative MDM-SPECT in 2 patients and negative ceMRI and positive MDM-SPECT in 3 patients. Tc-MDM-SPECT, F-FLT PET, and ceMRI scan findings were positive in 9 of 16 and negative in 5 of 16 patients. In the remaining 2 of 16 patients, both F-FLT-PET and Tc-MDM-SPECT were positive, but ceMRI was negative. Sensitivity, specificity, PPV, NPV, and DA of Tc-MDM-SPECT for diagnosing recurrent/residual glioma were 88.24%, 81.25%, 83.3%, 86.7%, and 84.8%, respectively. The diagnostic accuracy of Tc-bis-methionine (MDM)-SPECT imaging was comparable with that of ceMRI and F-FLT-PET and may be useful in the management of glioma patients in the postsurgical follow-up period. This imaging technique may be of special interest in peripheral hospitals/developing countries lacking access to expensive PET/cyclotron technology. However, comparison with the existing "gold standard" PET tracers, especially with C-11-methionine-PET imaging and histopathological correlation, is warranted in a large cohort of glioma patients through multicentric studies.

Differential diagnosis of atypical lipomatous tumor/well-differentiated liposarcoma and dedifferentiated liposarcoma: utility of p16 in combination with MDM2 and CDK4 immunohistochemistry.

PubMed

Kammerer-Jacquet, Solène-Florence; Thierry, Sixte; Cabillic, Florian; Lannes, Morgane; Burtin, Florence; Henno, Sébastien; Dugay, Frédéric; Bouzillé, Guillaume; Rioux-Leclercq, Nathalie; Belaud-Rotureau, Marc-Antoine; Stock, Nathalie

2017-01-01

The differential diagnosis between atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDLPS) and dedifferentiated liposarcoma (DDLPS) from their morphologic counterparts is challenging. Currently, the diagnosis is guided by MDM2 and CDK4 immunohistochemistry (IHC) and is confirmed by the amplification of the corresponding genes. Recently, p16 IHC has been proposed as a useful diagnostic biomarker. The objective was to assess the utility of p16 IHC in the differential diagnosis of ALT/WDLPS and DDLPS. Our series included 101 tumors that were previously analyzed using fluorescence in situ hybridization for MDM2 and CDK4 amplification. We compared sensitivity and specificity of p16 IHC to MDM2 and CDK4 IHC in the differential diagnosis of ALT-WDLPS (n=19) versus benign adipocytic tumors (n=44) and DDLPS (n=18) versus mimicking sarcomas (n=20). In the differential diagnosis of ALT-WDLPS, p16 had a sensitivity of 89.5% but a specificity of 68.2%, which was impaired by false-positive lipomas with secondary changes, especially in biopsies. Likewise, in the differential diagnosis of DDLPS, p16 had a sensitivity of 94.4% and a specificity of 70%, which hampered its use as a single marker. However, adding p16 to MDM2 and/or CDK4 increased diagnostic specificity. Indeed, MDM2+/p16+ tumors were all ALT-WDLPS, and MDM2-/p16- tumors were all benign adipocytic tumors. Moreover, all MDM2+/CDK4+/p16+ tumors were DDLPS, and the MDM2-/CDK4-/p16- tumor was an undifferentiated sarcoma. Although the use of p16 as a single immunohistochemical marker is limited by its specificity, its combination with MDM2 and CDK4 IHC may help discriminate ALT-WDLPS/DDLPS. Copyright © 2016 Elsevier Inc. All rights reserved.

Opposite regulation of MDM2 and MDMX expression in acquisition of mesenchymal phenotype in benign and cancer cells.

PubMed

Slabáková, Eva; Kharaishvili, Gvantsa; Smějová, Monika; Pernicová, Zuzana; Suchánková, Tereza; Remšík, Ján; Lerch, Stanislav; Straková, Nicol; Bouchal, Jan; Král, Milan; Culig, Zoran; Kozubík, Alois; Souček, Karel

2015-11-03

Plasticity of cancer cells, manifested by transitions between epithelial and mesenchymal phenotypes, represents a challenging issue in the treatment of neoplasias. Both epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET) are implicated in the processes of metastasis formation and acquisition of stem cell-like properties. Mouse double minute (MDM) 2 and MDMX are important players in cancer progression, as they act as regulators of p53, but their function in EMT and metastasis may be contradictory. Here, we show that the EMT phenotype in multiple cellular models and in clinical prostate and breast cancer samples is associated with a decrease in MDM2 and increase in MDMX expression. Modulation of EMT-accompanying changes in MDM2 expression in benign and transformed prostate epithelial cells influences their migration capacity and sensitivity to docetaxel. Analysis of putative mechanisms of MDM2 expression control demonstrates that in the context of defective p53 function, MDM2 expression is regulated by EMT-inducing transcription factors Slug and Twist. These results provide an alternative context-specific role of MDM2 in EMT, cell migration, metastasis, and therapy resistance.

Slow-light enhanced subwavelength plasmonic waveguide refractive index sensors.

PubMed

Huang, Yin; Min, Changjun; Dastmalchi, Pouya; Veronis, Georgios

2015-06-01

We introduce slow-light enhanced subwavelength scale refractive index sensors which consist of a plasmonic metal-dielectric-metal (MDM) waveguide based slow-light system sandwiched between two conventional MDM waveguides. We first consider a MDM waveguide with small width structrue for comparison, and then consider two MDM waveguide based slow light systems: a MDM waveguide side-coupled to arrays of stub resonators system and a MDM waveguide side-coupled to arrays of double-stub resonators system. We find that, as the group velocity decreases, the sensitivity of the effective index of the waveguide mode to variations of the refractive index of the fluid filling the sensors as well as the sensitivities of the reflection and transmission coefficients of the waveguide mode increase. The sensing characteristics of the slow-light waveguide based sensor structures are systematically analyzed. We show that the slow-light enhanced sensors lead to not only 3.9 and 3.5 times enhancements in the refractive index sensitivity, and therefore in the minimum detectable refractive index change, but also to 2 and 3 times reductions in the required sensing length, respectively, compared to a sensor using a MDM waveguide with small width structure.

How To Design a Successful p53-MDM2/X Interaction Inhibitor: A Thorough Overview Based on Crystal Structures.

PubMed

Estrada-Ortiz, Natalia; Neochoritis, Constantinos G; Dömling, Alexander

2016-04-19

A recent therapeutic strategy in oncology is based on blocking the protein-protein interaction between the murine double minute (MDM) homologues MDM2/X and the tumor-suppressor protein p53. Inhibiting the binding between wild-type (WT) p53 and its negative regulators MDM2 and/or MDMX has become an important target in oncology to restore the antitumor activity of p53, the so-called guardian of our genome. Interestingly, based on the multiple disclosed compound classes and structural analysis of small-molecule-MDM2 adducts, the p53-MDM2 complex is perhaps the best studied and most targeted protein-protein interaction. Several classes of small molecules have been identified as potent, selective, and efficient inhibitors of the p53-MDM2/X interaction, and many co-crystal structures with the protein are available. Herein we review the properties as well as preclinical and clinical studies of these small molecules and peptides, categorized by scaffold type. A particular emphasis is made on crystallographic structures and the observed binding modes of these compounds, including conserved water molecules present. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A critical role for noncoding 5S rRNA in regulating Mdmx stability.

PubMed

Li, Muyang; Gu, Wei

2011-09-16

Both p53 and Mdmx are ubiquitinated and degraded by the same E3 ligase Mdm2; interestingly, however, while p53 is rapidly degraded by Mdm2, Mdmx is a stable protein in most cancer cells. Thus, the mechanism by which Mdmx is degraded by Mdm2 needs further elucidation. Here, we identified the noncoding 5S rRNA as a major component of Mdmx-associated complexes from human cells. We show that 5S rRNA acts as a natural inhibitor of Mdmx degradation by Mdm2. RNAi-mediated knockdown of endogenous 5S rRNA, while not affecting p53 levels, significantly induces Mdmx degradation and, subsequently, activates p53-dependent growth arrest. Notably, 5S rRNA binds the RING domain of Mdmx and blocks its ubiquitination by Mdm2, whereas Mdm2-mediated p53 ubiquitination remains intact. These results provide insights into the differential effects on p53 and Mdmx by Mdm2 in vivo and reveal a critical role for noncoding 5S rRNA in modulating the p53-Mdmx axis. Copyright © 2011 Elsevier Inc. All rights reserved.

The electrostatic surface of MDM2 modulates the specificity of its interaction with phosphorylated and unphosphorylated p53 peptides.

PubMed

Brown, Christopher John; Srinivasan, Deepa; Jun, Lee Hui; Coomber, David; Verma, Chandra S; Lane, David P

2008-03-01

Florescence anisotropy measurements using FAM-labelled p53 peptides showed that the binding of the peptides to MDM2 was dependant upon the phosphorylation of p53 at Thr18 and that this binding was modulated by the electrostatic properties of MDM2. In agreement with computational predictions, the binding to phosphorylated p53 peptide, in comparison to the unphosphorylated p53 peptide, was enhanced upon mutation of 3 key residues on the MDM2 surface.

Synergistic Inhibition of Her2/neu and p53-MDM2 Pathways. Addendum

DTIC Science & Technology

2007-09-01

Therefore, combination of drugs targeting HER2/neu and MDM2 pathways will allow for a two-pronged attack on breast cancer. The overall objective of our...proposal is to determine if small molecule drugs designed to inhibit HER2/neu can be applied in combination with drugs designed to inhibit p53-MDM2...able to inhibit either the HER2/neu pathway or the p53-MDM2 pathway. Subsequently, designed small molecule drugs able to strongly induce apoptosis

The Membrane-Bound NAC Transcription Factor ANAC013 Functions in Mitochondrial Retrograde Regulation of the Oxidative Stress Response in Arabidopsis[C][W

PubMed Central

De Clercq, Inge; Vermeirssen, Vanessa; Van Aken, Olivier; Vandepoele, Klaas; Murcha, Monika W.; Law, Simon R.; Inzé, Annelies; Ng, Sophia; Ivanova, Aneta; Rombaut, Debbie; van de Cotte, Brigitte; Jaspers, Pinja; Van de Peer, Yves; Kangasjärvi, Jaakko; Whelan, James; Van Breusegem, Frank

2013-01-01

Upon disturbance of their function by stress, mitochondria can signal to the nucleus to steer the expression of responsive genes. This mitochondria-to-nucleus communication is often referred to as mitochondrial retrograde regulation (MRR). Although reactive oxygen species and calcium are likely candidate signaling molecules for MRR, the protein signaling components in plants remain largely unknown. Through meta-analysis of transcriptome data, we detected a set of genes that are common and robust targets of MRR and used them as a bait to identify its transcriptional regulators. In the upstream regions of these mitochondrial dysfunction stimulon (MDS) genes, we found a cis-regulatory element, the mitochondrial dysfunction motif (MDM), which is necessary and sufficient for gene expression under various mitochondrial perturbation conditions. Yeast one-hybrid analysis and electrophoretic mobility shift assays revealed that the transmembrane domain–containing NO APICAL MERISTEM/ARABIDOPSIS TRANSCRIPTION ACTIVATION FACTOR/CUP-SHAPED COTYLEDON transcription factors (ANAC013, ANAC016, ANAC017, ANAC053, and ANAC078) bound to the MDM cis-regulatory element. We demonstrate that ANAC013 mediates MRR-induced expression of the MDS genes by direct interaction with the MDM cis-regulatory element and triggers increased oxidative stress tolerance. In conclusion, we characterized ANAC013 as a regulator of MRR upon stress in Arabidopsis thaliana. PMID:24045019

Tight regulation of p53 activity by Mdm2 is required for ureteric bud growth and branching

PubMed Central

Hilliard, Sylvia; Aboudehen, Karam; Yao, Xiao; El-Dahr, Samir S.

2011-01-01

Mdm2 (Murine Double Minute-2) is required to control cellular p53 activity and protein levels. Mdm2 null embryos die of p53-mediated growth arrest and apoptosis at the peri-implantation stage. Thus, the absolute requirement for Mdm2 in organogenesis is unknown. This study examined the role of Mdm2 in kidney development, an organ which develops via epithelial-mesenchymal interactions and branching morphogenesis. Mdm2 mRNA and protein are expressed in the ureteric bud (UB) epithelium and metanephric mesenchyme (MM) lineages. We report here the results of conditional deletion of Mdm2 from the UB epithelium. UBmdm2−/− mice die soon after birth and uniformly display severe renal hypodysplasia due to defective UB branching and underdeveloped nephrogenic zone. Ex vivo cultured UBmdm2−/− explants exhibit arrested development of the UB and its branches and consequently develop few nephron progenitors. UBmdm2−/− cells have reduced proliferation rate and enhanced apoptosis. Although markedly reduced in number, the UB tips of UBmdm2−/− metanephroi continue to express c-ret and Wnt11; however, there was a notable reduction in Wnt9b, Lhx-1 and Pax-2 expression levels. We further show that the UBmdm2−/− mutant phenotype is mediated by aberrant p53 activity because it is rescued by UB-specific deletion of the p53 gene. These results demonstrate a critical and cell autonomous role for Mdm2 in the UB lineage. Mdm2-mediated inhibition of p53 activity is a prerequisite for renal organogenesis. PMID:21420949

MDM2 and CDK4 amplifications are rare events in salivary duct carcinomas

PubMed Central

Grünewald, Inga; Trautmann, Marcel; Busch, Alina; Bauer, Larissa; Huss, Sebastian; Schweinshaupt, Petra; Vollbrecht, Claudia; Odenthal, Margarete; Quaas, Alexander; Büttner, Reinhard; Meyer, Moritz F.; Beutner, Dirk; Hüttenbrink, Karl-Bernd; Wardelmann, Eva; Stenner, Markus; Hartmann, Wolfgang

2016-01-01

Salivary duct carcinoma (SDC) is an aggressive adenocarcinoma of the salivary glands associated with poor clinical outcome. SDCs are known to carry TP53 mutations in about 50%, however, only little is known about alternative pathogenic mechanisms within the p53 regulatory network. Particularly, data on alterations of the oncogenes MDM2 and CDK4 located in the chromosomal region 12q13-15 are limited in SDC, while genomic rearrangements of the adjacent HMGA2 gene locus are well documented in subsets of SDCs. We here analyzed the mutational status of the TP53 gene, genomic amplification of MDM2, CDK4 and HMGA2 rearrangement/amplification as well as protein expression of TP53 (p53), MDM2 and CDK4 in 51 de novo and ex pleomorphic adenoma SDCs. 25 of 51 cases were found to carry TP53 mutations, associated with extreme positive immunohistochemical p53 staining levels in 13 cases. Three out of 51 tumors had an MDM2 amplification, one of them coinciding with a CDK4 amplification and two with a HMGA2 rearrangement/amplification. Two of the MDM2 amplifications occurred in the setting of a TP53 mutation. Two out of 51 cases showed a CDK4 amplification, one synchronously being MDM2 amplified and the other one displaying concurrent low copy number increases of both, MDM2 and HMGA2. In summary, we here show that subgroups of SDCs display genomic amplifications of MDM2 and/or CDK4, partly in association with TP53 mutations and rearrangement/amplification of HMGA2. Further research is necessary to clarify the role of chromosomal region 12q13-15 alterations in SDC tumorigenesis and their potential prognostic and therapeutic relevance. PMID:27662657

MDM2 and CDK4 amplifications are rare events in salivary duct carcinomas.

PubMed

Grünewald, Inga; Trautmann, Marcel; Busch, Alina; Bauer, Larissa; Huss, Sebastian; Schweinshaupt, Petra; Vollbrecht, Claudia; Odenthal, Margarete; Quaas, Alexander; Büttner, Reinhard; Meyer, Moritz F; Beutner, Dirk; Hüttenbrink, Karl-Bernd; Wardelmann, Eva; Stenner, Markus; Hartmann, Wolfgang

2016-11-15

Salivary duct carcinoma (SDC) is an aggressive adenocarcinoma of the salivary glands associated with poor clinical outcome. SDCs are known to carry TP53 mutations in about 50%, however, only little is known about alternative pathogenic mechanisms within the p53 regulatory network. Particularly, data on alterations of the oncogenes MDM2 and CDK4 located in the chromosomal region 12q13-15 are limited in SDC, while genomic rearrangements of the adjacent HMGA2 gene locus are well documented in subsets of SDCs. We here analyzed the mutational status of the TP53 gene, genomic amplification of MDM2, CDK4 and HMGA2 rearrangement/amplification as well as protein expression of TP53 (p53), MDM2 and CDK4 in 51 de novo and ex pleomorphic adenoma SDCs.25 of 51 cases were found to carry TP53 mutations, associated with extreme positive immunohistochemical p53 staining levels in 13 cases. Three out of 51 tumors had an MDM2 amplification, one of them coinciding with a CDK4 amplification and two with a HMGA2 rearrangement/amplification. Two of the MDM2 amplifications occurred in the setting of a TP53 mutation. Two out of 51 cases showed a CDK4 amplification, one synchronously being MDM2 amplified and the other one displaying concurrent low copy number increases of both, MDM2 and HMGA2.In summary, we here show that subgroups of SDCs display genomic amplifications of MDM2 and/or CDK4, partly in association with TP53 mutations and rearrangement/amplification of HMGA2. Further research is necessary to clarify the role of chromosomal region 12q13-15 alterations in SDC tumorigenesis and their potential prognostic and therapeutic relevance.

MDM2 controls NRF2 antioxidant activity in prevention of diabetic kidney disease.

PubMed

Guo, Weiying; Tian, Dan; Jia, Ye; Huang, Wenlin; Jiang, Mengnan; Wang, Junnan; Sun, Weixia; Wu, Hao

2018-04-26

Oxidative stress and P53 contribute to the pathogenesis of diabetic kidney disease (DKD). Nuclear factor erythroid 2-related factor 2 (NRF2) is a master regulator of cellular antioxidant defense system, is negatively regulated by P53 and prevents DKD. Recent findings revealed an important role of mouse double minute 2 (MDM2) in protection against DKD. However, the mechanism remained unclear. We hypothesized that MDM2 enhances NRF2 antioxidant signaling in DKD given that MDM2 is a key negative regulator of P53. The MDM2 inhibitor nutlin3a elevated renal P53, inhibited NRF2 signaling and induced oxidative stress, inflammation, fibrosis, DKD-like renal pathology and albuminuria in the wild-type (WT) non-diabetic mice. These effects exhibited more prominently in nutlin3a-treated WT diabetic mice. Interestingly, nutlin3a failed to induce greater renal injuries in the Nrf2 knockout (KO) mice under both the diabetic and non-diabetic conditions, indicating that NRF2 predominantly mediates MDM2's action. On the contrary, P53 inhibition by pifithrin-α activated renal NRF2 signaling and the expression of Mdm2, and attenuated DKD in the WT diabetic mice, but not in the Nrf2 KO diabetic mice. In high glucose-treated mouse mesangial cells, P53 gene silencing completely abolished nutlin3a's inhibitory effect on NRF2 signaling. The present study demonstrates for the first time that MDM2 controls renal NRF2 antioxidant activity in DKD via inhibition of P53, providing MDM2 activation and P53 inhibition as novel strategies in the management of DKD. Copyright © 2018 Elsevier B.V. All rights reserved.

Multidisciplinary lung cancer meetings: improving the practice of radiation oncology and facing future challenges.

PubMed

Campbell, Belinda A; Ball, David; Mornex, Françoise

2015-02-01

Clinical guidelines widely recognize the importance of multidisciplinary meetings (MDM) in the optimal care of lung cancer patients. The published literature suggest that dedicated Lung Cancer MDM lead to increased treatment utilization rates and improved survival outcomes for patients with lung cancer. For radiation oncologists, Lung Cancer MDM have been proven to support evidence-based practice and improve the utilization of radiotherapy. Lung Cancer MDM also allow for education and promotion of specialty radiotherapy services. The fast pace of modern medicine is also presenting new challenges for the multidisciplinary lung cancer team, and technological advances are likely to lead to new changes in the structure of traditional Lung Cancer MDM. © 2015 Asian Pacific Society of Respirology.

The in vitro fungicidal activity of human macrophages against Penicillium marneffei is suppressed by dexamethasone.

PubMed

Ma, Tuan; Chen, Renqiong; Li, Xiqing; Lu, Changming; Xi, Liyan

2015-09-01

Penicillium marneffei (P. marneffei) is a pathogenic fungus that can persist in macrophages and cause a life-threatening systemic mycosis in immunocompromised hosts. To elucidate the mechanisms underlying this opportunistic fungal infection, we established the co-culture system of P. marneffei conidia and human monocyte-derived macrophages (MDM) for investigating the interactions between them. And, we impaired the immune state of MDM by the addition of dexamethasone (DEX). Compared with immunocompetent MDM without DEX treatment in response to P. marneffei, DEX could damage MDM function in initiating the innate immune response through decreasing TNF-α production and the proportion of P. marneffei conidia in mature phagolysosomes, while the red pigment secretion by P. marneffei conidia was promoted by DEX following MDM lysis. Our data provide the evidence that DEX-treated MDM have a low fungicidal activity against P. marneffei that causes penicilliosis in immunocompromised hosts. Copyright © 2015 Elsevier Ltd. All rights reserved.

Structural and mechanistic insights into phospholipid transfer by Ups1-Mdm35 in mitochondria

NASA Astrophysics Data System (ADS)

Watanabe, Yasunori; Tamura, Yasushi; Kawano, Shin; Endo, Toshiya

2015-08-01

Eukaryotic cells are compartmentalized into membrane-bounded organelles whose functions rely on lipid trafficking to achieve membrane-specific compositions of lipids. Here we focused on the Ups1-Mdm35 system, which mediates phosphatidic acid (PA) transfer between the outer and inner mitochondrial membranes, and determined the X-ray structures of Mdm35 and Ups1-Mdm35 with and without PA. The Ups1-Mdm35 complex constitutes a single domain that has a deep pocket and flexible Ω-loop lid. Structure-based mutational analyses revealed that a basic residue at the pocket bottom and the Ω-loop lid are important for PA extraction from the membrane following Ups1 binding. Ups1 binding to the membrane is enhanced by the dissociation of Mdm35. We also show that basic residues around the pocket entrance are important for Ups1 binding to the membrane and PA extraction. These results provide a structural basis for understanding the mechanism of PA transfer between mitochondrial membranes.

Improved epileptic seizure detection combining dynamic feature normalization with EEG novelty detection.

PubMed

Bogaarts, J G; Hilkman, D M W; Gommer, E D; van Kranen-Mastenbroek, V H J M; Reulen, J P H

2016-12-01

Continuous electroencephalographic monitoring of critically ill patients is an established procedure in intensive care units. Seizure detection algorithms, such as support vector machines (SVM), play a prominent role in this procedure. To correct for inter-human differences in EEG characteristics, as well as for intra-human EEG variability over time, dynamic EEG feature normalization is essential. Recently, the median decaying memory (MDM) approach was determined to be the best method of normalization. MDM uses a sliding baseline buffer of EEG epochs to calculate feature normalization constants. However, while this method does include non-seizure EEG epochs, it also includes EEG activity that can have a detrimental effect on the normalization and subsequent seizure detection performance. In this study, EEG data that is to be incorporated into the baseline buffer are automatically selected based on a novelty detection algorithm (Novelty-MDM). Performance of an SVM-based seizure detection framework is evaluated in 17 long-term ICU registrations using the area under the sensitivity-specificity ROC curve. This evaluation compares three different EEG normalization methods, namely a fixed baseline buffer (FB), the median decaying memory (MDM) approach, and our novelty median decaying memory (Novelty-MDM) method. It is demonstrated that MDM did not improve overall performance compared to FB (p < 0.27), partly because seizure like episodes were included in the baseline. More importantly, Novelty-MDM significantly outperforms both FB (p = 0.015) and MDM (p = 0.0065).

Experimental Therapy of Advanced Breast Cancer: Targeting NFAT1-MDM2-p53 Pathway.

PubMed

Qin, Jiang-Jiang; Wang, Wei; Zhang, Ruiwen

2017-01-01

Advanced breast cancer, especially advanced triple-negative breast cancer, is typically more aggressive and more difficult to treat than other breast cancer phenotypes. There is currently no curable option for breast cancer patients with advanced diseases, highlighting the urgent need for novel treatment strategies. We have recently discovered that the nuclear factor of activated T cells 1 (NFAT1) activates the murine double minute 2 (MDM2) oncogene. Both MDM2 and NFAT1 are overexpressed and constitutively activated in breast cancer, particularly in advanced breast cancer, and contribute to its initiation, progression, and metastasis. MDM2 regulates cancer cell proliferation, cell cycle progression, apoptosis, migration, and invasion through both p53-dependent and -independent mechanisms. We have proposed to target the NFAT1-MDM2-p53 pathway for the treatment of human cancers, especially breast cancer. We have recently identified NFAT1 and MDM2 dual inhibitors that have shown excellent in vitro and in vivo activities against breast cancer, including triple-negative breast cancer. Herein, we summarize recent advances made in the understanding of the oncogenic functions of MDM2 and NFAT1 in breast cancer, as well as current targeting strategies and representative inhibitors. We also propose several strategies for inhibiting the NFAT1-MDM2-p53 pathway, which could be useful for developing more specific and effective inhibitors for breast cancer therapy. Copyright © 2017. Published by Elsevier Inc.

Synergistic targeting of malignant pleural mesothelioma cells by MDM2 inhibitors and TRAIL agonists

PubMed Central

Urso, Loredana; Biasini, Lorena; Zago, Giulia; Calabrese, Fiorella; Conte, Pier Franco; Ciminale, Vincenzo; Pasello, Giulia

2017-01-01

Malignant Pleural Mesothelioma (MPM) is a chemoresistant tumor characterized by low rate of p53 mutation and upregulation of Murine Double Minute 2 (MDM2), suggesting that it may be effectively targeted using MDM2 inhibitors. In the present study, we investigated the anticancer activity of the MDM2 inhibitors Nutlin 3a (in vitro) and RG7112 (in vivo), as single agents or in combination with rhTRAIL. In vitro studies were performed using MPM cell lines derived from epithelioid (ZL55, M14K), biphasic (MSTO211H) and sarcomatoid (ZL34) MPMs. In vivo studies were conducted on a sarcomatoid MPM mouse model. In all the cell lines tested (with the exception of ZL55, which carries a biallelic loss-of-function mutation of p53), Nutlin 3a enhanced p21, MDM2 and DR5 expression, and decreased survivin expression. These changes were associated to cell cycle arrest but not to a significant induction of apoptosis. A synergistic pro-apoptotic effect was obtained through the association of rhTRAIL in all the cell lines harboring functional p53. This synergistic interaction of MDM2 inhibitor and TRAIL agonist was confirmed using a mouse preclinical model. Our results suggest that the combined targeting of MDM2 and TRAIL might provide a novel therapeutic option for treatment of MPM patients, particularly in the case of sarcomatoid MPM with MDM2 overexpression and functional inactivation of wild-type p53. PMID:28562336

Design and Testing of Bi-functional, P-loop Targeted MDM2 Inhibitors

DTIC Science & Technology

2008-03-01

Nucleotide Binding Activity of the Mdm2 RING Domain Christina Priest, Masha Poyurovsky, Brent Stockwell and Carol Prives Department of Biological Sciences...Deconstructing nucleotide binding activity of the Mdm2 RING domain Christina Priest, Carol Prives* and Masha V. Poyurovsky Department of Biological Sciences

Rapid and efficient hydrophilicity tuning of p53/mdm2 antagonists*

PubMed Central

Srivastava, Stuti; Beck, Barbara; Wang, Wei; Czarna, Anna; Holak, Tad A.; Dömling, Alexander

2009-01-01

The protein-protein interaction of p53 and mdm2 is an important anticancer target. The interface, however, is very hydrophobic and naturally results in very hydrophobic antagonists. We used the Orru three component reaction (O-3CR) along with a rapid and efficient, recently discovered amidation reaction to dramatically improve the water solubility of our recently discovered low molecular weight p53/mdm2 antagonists. Arrays of amides were synthesized with improved hydrophilicity and retainment and/or improvement of p53/mdm2 inhibitory activity. PMID:19548636

Generation of oscillations by the p53-Mdm2 feedback loop: A theoretical and experimental study

PubMed Central

Lev Bar-Or, Ruth; Maya, Ruth; Segel, Lee A.; Alon, Uri; Levine, Arnold J.; Oren, Moshe

2000-01-01

The intracellular activity of the p53 tumor suppressor protein is regulated through a feedback loop involving its transcriptional target, mdm2. We present a simple mathematical model suggesting that, under certain circumstances, oscillations in p53 and Mdm2 protein levels can emerge in response to a stress signal. A delay in p53-dependent induction of Mdm2 is predicted to be required, albeit not sufficient, for this oscillatory behavior. In line with the predictions of the model, oscillations of both p53 and Mdm2 indeed occur on exposure of various cell types to ionizing radiation. Such oscillations may allow cells to repair their DNA without risking the irreversible consequences of continuous excessive p53 activation. PMID:11016968

Structural basis of intramitochondrial phosphatidic acid transport mediated by Ups1-Mdm35 complex.

PubMed

Yu, Fang; He, Fangyuan; Yao, Hongyan; Wang, Chengyuan; Wang, Jianchuan; Li, Jianxu; Qi, Xiaofeng; Xue, Hongwei; Ding, Jianping; Zhang, Peng

2015-07-01

Ups1 forms a complex with Mdm35 and is critical for the transport of phosphatidic acid (PA) from the mitochondrial outer membrane to the inner membrane. We report the crystal structure of the Ups1-Mdm35-PA complex and the functional characterization of Ups1-Mdm35 in PA binding and transfer. Ups1 features a barrel-like structure consisting of an antiparallel β-sheet and three α-helices. Mdm35 adopts a three-helical clamp-like structure to wrap around Ups1 to form a stable complex. The β-sheet and α-helices of Ups1 form a long tunnel-like pocket to accommodate the substrate PA, and a short helix α2 acts as a lid to cover the pocket. The hydrophobic residues lining the pocket and helix α2 are critical for PA binding and transfer. In addition, a hydrophilic patch on the surface of Ups1 near the PA phosphate-binding site also plays an important role in the function of Ups1-Mdm35. Our study reveals the molecular basis of the function of Ups1-Mdm35 and sheds new light on the mechanism of intramitochondrial phospholipid transport by the MSF1/PRELI family proteins. © 2015 The Authors.

Co-expression of p53 and MDM2 in human atherosclerosis: implications for the regulation of cellularity of atherosclerotic lesions.

PubMed

Ihling, C; Haendeler, J; Menzel, G; Hess, R D; Fraedrich, G; Schaefer, H E; Zeiher, A M

1998-07-01

Atherosclerosis is a fibroproliferative disease of the arterial intima. It was recently found that wild-type p53 (wt p53) accumulates in human atherosclerotic tissue. Wt p53 is a cell cycle regulator involved in DNA repair, DNA synthesis, cell differentiation, and apoptosis and might therefore make an important contribution to the cellularity of atherosclerotic plaques. The product of the MDM2 gene is a nuclear protein which forms a complex with p53, thereby inhibiting the negative regulatory effects of wt p53 on cell cycle progression. In order to address a potential role of the interaction of p53 with MDM2 for the regulation of cellularity in atherosclerotic tissue, 22 carotid atheromatous plaques from patients undergoing endarterectomy were studied to determine the presence of p53 immunoreactivity (IR), MDM2 IR, cell proliferation as evidenced by MIB1/Ki-67 IR and DNA fragmentation by in situ terminal transferase-mediated dUTP 3' end labelling (TUNEL), as a marker for apoptosis. p53 IR localized to areas with evidence of chronic inflammation (22/22) and was observed in virtually all cell types in 68.79 +/- 7.51 per cent of the nuclei. p53 staining in the control tissue from human internal mammary arteries was present in 0.2 +/- 0.29 per cent of the cells (P < or = 0.002). MDM2 IR was present in all cases (22/22) in macrophages and smooth muscle cells (SMCs) in 60.53 +/- 8.32 per cent of the nuclei (controls: 0.8 +/- 0.65 per cent, P < or = 0.002) and co-localized with p53 IR as shown by examination of adjacent sections and by double immunofluorescence labelling. Importantly, co-immunoprecipitation and western blot analysis revealed that p53 and MDM2 were physically associated, indicating that MDM2-p53 complex formation takes place in vivo in human atherosclerotic tissue. Positive TUNEL staining and MIB1/Ki-67 IR present in 3.01 +/- 1.27 per cent of the nuclei (controls: 0 per cent, P < or = 0.002) localized to the same plaque compartments as p53 IR and MDM2 IR. Thus, the fate of cells with p53 accumulation may depend on the interaction and the stoichiometry of the p53 and MDM2 proteins. Cells were indeed found with strong p53 accumulation and nuclear morphology typical for apoptosis and there were a few MIB1/Ki-67-positive cells with co-expression of MDM2, indicating a possible role for MDM2 in reversing the negative regulatory effects of p53 for cell cycle progression. The nuclear co-localization of p53 IR with MDM2 IR and the co-immunoprecipitation assay indicate the presence of p53-MDM2 complex formation in vivo in human atherosclerotic tissue. The destiny of individual p53 and MDM2-co-expressing cells either to undergo p53-dependent apoptosis or to re-enter the cycle of cell proliferation may depend on the relative ratios of the two proteins. p53 and MDM2 may therefore play an important role in regulating cellularity and inflammatory activity in human atherosclerotic plaques.

[Interaction between p53 and MDM2 in human lung cancer cells].

PubMed

Rybárová, S; Hodorová, I; Vecanová, J; Muri, J; Mihalik, J

2014-01-01

The oncoprotein p53 protein induces cell growth arrest (apoptosis) in response to endo  or exogenous stimuli. Mutation of TP53 (gene encoding the p53 protein) is common in human malignancies and alters the conformation of p53. The result is a more stable protein which accumulates in nuclei of tumor cells with loss of function. Mutant p53 is stabilized, and it is possible to detect this form very clearly by immunohistochemistry (IHC). Expression of the MDM2 protein is used as a potential marker of p53 function. P53 levels in normal cells are highly determined by the MDM2 protein (murine double minute 2) -  mediated degradation of p53. MDM2 overexpression represents at least one mechanism by which p53 function can be abrogated during tumorigenesis. Lung carcinoma samples were obtained from patients, who underwent radical resection (lobectomy or pulmonectomy and lymphadectomy). Pathological dia-gnosis was based on the WHO criteria. In our study, we investigated the expression of p53 and MDM2 protein that might improve IHC as a marker for p53 status. Proteins were IHC detected in 136 samples of primary lung carcinoma. Immunostaining results of p53 positive samples were compared to IHC expression of MDM2 positive and MDM2 negative samples. Strong brown nuclear staining was visible in p53 and MDM2 positive cells. The most p53 positive cases were samples of squamocellular carcinoma (55%), then samples of large cell carcinoma (53%) and 26% adenocarcinoma samples showed the p53 immunoreactivity. No one sample of different types was p53 positive. When we compared the p53 expression and grade of tumor, we found that the p53 expression increased with the grade of tumor. For statistical evaluation, the chi square test was used. The relationship between p53 expression and type of tumor, also the p53 expression and grade of tumor was statistically significant (p = 0.000425; p = 0.00157). Regarding p53 and MDM2 expression, only nine samples (7%) were simultaneously p53 and MDM2 positive. In 46 (34%) cases, elevation of p53 was combined with MDM2 negative expression. Other tumor samples were either negative for both proteins (71/ 52%), or p53 negative and MDM2 positive in 10 (7%) tumor samples. Absence of p53 staining in most studies indicates absence of p53 mutation, and on the contrary, positive expression of p53 is a sign of p53 mutations with loss of function. In our study, 34% of cases with extensively high level of p53 without increased level of MDM2 were identified. We suppose that these are tumors with inactivating mutations that stabilize p53. On the other hand, tumors with high level of stabilized wildtype p53 protein and simultaneously with increased MDM2 staining (9 samples/7%) represent group with functional p53. In this group of patients, we could expect better prognosis with regard to function of p53 protein.

Colorectal multidisciplinary meeting audit to determine patient benefit.

PubMed

Fernando, Chris; Frizelle, Frank; Wakeman, Chris; Frampton, Chris; Robinson, Bridget

2017-11-01

New Zealand tumour standards require discussion of all cases of colorectal cancer in a multidisciplinary meeting (MDM), but supporting evidence is lacking. The aim was to determine which patients benefit from MDM discussion. A retrospective and prospective audit was undertaken of all patients discussed in the Christchurch Hospital colorectal MDM over 12 months to November 2014, who were compared with contemporaneous patients not discussed and identified through Hospital discharge codes. In total, 641 patients were identified, with 459 (70%) discussed in the MDM, on average 7 years younger than not discussed. The proportion discussed by location was 39.2% colon, 63% rectosigmoid, 98% rectal, 96.6% anal. Discussed patients were more likely to have magnetic resonance imaging (68% cf 9.3%), fluorodeoxyglucose positron emission tomography scan (18% versus 2%) and chest computerized tomography scan (50% versus 26%). For colon cancer, American Joint Committee on Cancer (AJCC) stage I and II, 91% of 68 non-discussed patients went straight to surgery compared with 48% of 27 discussed in the MDM; for AJCC stage III uptake of adjuvant chemotherapy was the same whether discussed or not. An R0 resection was achieved for 91% of discussed patients, and 96% of not discussed. A clear referrer's plan, prospectively recorded in 94 patients, was changed after the MDM in 23%. Clinical staging was changed in 20 patients (4%), none with colon cancers. Discussion in the MDM influenced management, but was unlikely to change management for AJCC stage I/II colon cancer, who could be spared mandatory review in the MDM and be discussed selectively as treating clinicians decide. © 2015 Royal Australasian College of Surgeons.

Is there a rationale to use a dual mobility poly insert for failed Birmingham metal-on-metal hip replacements? A retrieval analysis.

PubMed

Renner, Lisa; Faschingbauer, Martin; Boettner, Friedrich

2015-08-01

Previous studies showed poor outcomes for patients undergoing revision of failed metal-on-metal total hip arthroplasty (MoM-THA) and resurfacing (RS) with an increased risk of dislocation. Dual mobility inserts are an option to retain the acetabular component and change the metal-on-metal bearing to plastic-on-metal. The current study analyzes the rationale for the off-label use of a dual mobility poly insert (MDM X3, Stryker, Mahwah, NJ) in a Birmingham metal shell (Smith & Nephew, Memphis, TN). Based on retrievals from the implant database the study compared the clearance between 20 BHR shells, 31 MDM poly inserts and 24 ADM acetabular components of different sizes. The radial clearance was calculated for each possible combination of implants [n = 81 (MDM/BHR) and n = 119 (MDM/ADM)]. An MDM mobile bearing poly insert in an ADM shell has an average clearance of 0.314 mm (SD 0.031) compared to 0.234 mm (SD 0.030) in a BHR shell (p < 0.01). The minimal clearance is 0.246 and 0.163 mm, respectively. 30.9 % of the MDM/BHR clearances were within the range of the MDM/ADM bearing and 88.9 % had a clearance of more than 0.2 mm. Clearances of the MDM poly insert in a BHR shell are reduced, and although the majority of combinations appear safe, the indication needs to be made on an individual base carefully considering alternative treatment options.

Disruption of the 5S RNP-Mdm2 interaction significantly improves the erythroid defect in a mouse model for Diamond-Blackfan anemia.

PubMed

Jaako, P; Debnath, S; Olsson, K; Zhang, Y; Flygare, J; Lindström, M S; Bryder, D; Karlsson, S

2015-11-01

Diamond-Blackfan anemia (DBA) is a congenital erythroid hypoplasia caused by haploinsufficiency of genes encoding ribosomal proteins (RPs). Perturbed ribosome biogenesis in DBA has been shown to induce a p53-mediated ribosomal stress response. However, the mechanisms of p53 activation and its relevance for the erythroid defect remain elusive. Previous studies have indicated that activation of p53 is caused by the inhibition of mouse double minute 2 (Mdm2), the main negative regulator of p53, by the 5S ribonucleoprotein particle (RNP). Meanwhile, it is not clear whether this mechanism solely mediates the p53-dependent component found in DBA. To approach this question, we crossed our mouse model for RPS19-deficient DBA with Mdm2(C305F) knock-in mice that have a disrupted 5S RNP-Mdm2 interaction. Upon induction of the Rps19 deficiency, Mdm2(C305F) reversed the p53 response and improved expansion of hematopoietic progenitors in vitro, and ameliorated the anemia in vivo. Unexpectedly, disruption of the 5S RNP-Mdm2 interaction also led to selective defect in erythropoiesis. Our findings highlight the sensitivity of erythroid progenitor cells to aberrations in p53 homeostasis mediated by the 5S RNP-Mdm2 interaction. Finally, we provide evidence indicating that physiological activation of the 5S RNP-Mdm2-p53 pathway may contribute to functional decline of the hematopoietic system in a cell-autonomous manner over time.

Small-molecule MDM2 antagonists reveal aberrant p53 signaling in cancer: Implications for therapy

PubMed Central

Tovar, Christian; Rosinski, James; Filipovic, Zoran; Higgins, Brian; Kolinsky, Kenneth; Hilton, Holly; Zhao, Xiaolan; Vu, Binh T.; Qing, Weiguo; Packman, Kathryn; Myklebost, Ola; Heimbrook, David C.; Vassilev, Lyubomir T.

2006-01-01

The p53 tumor suppressor retains its wild-type conformation and transcriptional activity in half of all human tumors, and its activation may offer a therapeutic benefit. However, p53 function could be compromised by defective signaling in the p53 pathway. Using a small-molecule MDM2 antagonist, nutlin-3, to probe downstream p53 signaling we find that the cell-cycle arrest function of the p53 pathway is preserved in multiple tumor-derived cell lines expressing wild-type p53, but many have a reduced ability to undergo p53-dependent apoptosis. Gene array analysis revealed attenuated expression of multiple apoptosis-related genes. Cancer cells with mdm2 gene amplification were most sensitive to nutlin-3 in vitro and in vivo, suggesting that MDM2 overexpression may be the only abnormality in the p53 pathway of these cells. Nutlin-3 also showed good efficacy against tumors with normal MDM2 expression, suggesting that many of the patients with wild-type p53 tumors may benefit from antagonists of the p53–MDM2 interaction. PMID:16443686

Structural and mechanistic insights into phospholipid transfer by Ups1–Mdm35 in mitochondria

PubMed Central

Watanabe, Yasunori; Tamura, Yasushi; Kawano, Shin; Endo, Toshiya

2015-01-01

Eukaryotic cells are compartmentalized into membrane-bounded organelles whose functions rely on lipid trafficking to achieve membrane-specific compositions of lipids. Here we focused on the Ups1–Mdm35 system, which mediates phosphatidic acid (PA) transfer between the outer and inner mitochondrial membranes, and determined the X-ray structures of Mdm35 and Ups1–Mdm35 with and without PA. The Ups1–Mdm35 complex constitutes a single domain that has a deep pocket and flexible Ω-loop lid. Structure-based mutational analyses revealed that a basic residue at the pocket bottom and the Ω-loop lid are important for PA extraction from the membrane following Ups1 binding. Ups1 binding to the membrane is enhanced by the dissociation of Mdm35. We also show that basic residues around the pocket entrance are important for Ups1 binding to the membrane and PA extraction. These results provide a structural basis for understanding the mechanism of PA transfer between mitochondrial membranes. PMID:26235513

Characterizing the Free-Energy Landscape of MDM2 Protein-Ligand Interactions by Steered Molecular Dynamics Simulations.

PubMed

Hu, Guodong; Xu, Shicai; Wang, Jihua

2015-12-01

Inhibition of p53-MDM2 interaction by small molecules is considered to be a promising approach to re-activate wild-type p53 for tumor suppression. Several inhibitors of the MDM2-p53 interaction were designed and studied by the experimental methods and the molecular dynamics simulation. However, the unbinding mechanism was still unclear. The steered molecular dynamics simulations combined with Brownian dynamics fluctuation-dissipation theorem were employed to obtain the free-energy landscape of unbinding between MDM2 and their four ligands. It was shown that compounds 4 and 8 dissociate faster than compounds 5 and 7. The absolute binding free energies for these four ligands are in close agreement with experimental results. The open movement of helix II and helix IV in the MDM2 protein-binding pocket upon unbinding is also consistent with experimental MDM2-unbound conformation. We further found that different binding mechanisms among different ligands are associated with H-bond with Lys51 and Glu25. These mechanistic results may be useful for improving ligand design. © 2015 John Wiley & Sons A/S.

Caspase-2-mediated cleavage of Mdm2 creates p53-induced positive feedback loop

PubMed Central

Oliver, Trudy G.; Meylan, Etienne; Chang, Gregory P.; Xue, Wen; Burke, James R.; Humpton, Timothy J.; Hubbard, Diana; Bhutkar, Arjun; Jacks, Tyler

2011-01-01

SUMMARY Caspase-2 is an evolutionarily conserved caspase, yet its biological function and cleavage targets are poorly understood. Caspase-2 is activated by the p53 target gene product PIDD (also known as LRDD) in a complex called the Caspase-2-PIDDosome. We show that PIDD expression promotes growth arrest and chemotherapy resistance by a mechanism that depends on Caspase-2 and wild-type p53. PIDD-induced Caspase-2 directly cleaves the E3 ubiquitin ligase Mdm2 at Asp 367, leading to loss of the C-terminal RING domain responsible for p53 ubiquitination. As a consequence, N-terminally truncated Mdm2 binds p53 and promotes its stability. Upon DNA damage, p53 induction of the Caspase-2-PIDDosome creates a positive feedback loop that inhibits Mdm2 and reinforces p53 stability and activity, contributing to cell survival and drug resistance. These data establish Mdm2 as a cleavage target of Caspase-2 and provide insight into a mechanism of Mdm2 inhibition that impacts p53 dynamics upon genotoxic stress. PMID:21726810

ATM phosphorylation of Mdm2 Ser394 regulates the amplitude and duration of the DNA damage response in mice

PubMed Central

Gannon, Hugh S.; Woda, Bruce A.; Jones, Stephen N.

2012-01-01

Summary DNA damage induced by ionizing radiation (IR) activates the ATM kinase, which subsequently stabilizes and activates the p53 tumor suppressor protein. Although phosphorylation of p53 by ATM was found previously to modulate p53 levels and transcriptional activities in vivo, it does not appear to be a major regulator of p53 stability. We have utilized mice bearing altered Mdm2 alleles to demonstrate that ATM phosphorylation of Mdm2 serine 394 is required for robust p53 stabilization and activation after DNA damage. In addition, we demonstrate that dephosphorylation of Mdm2 Ser394 regulates attenuation of the p53-mediated response to DNA damage. Therefore, the phosphorylation status of Mdm2 Ser394 governs p53 protein levels and functions in cells undergoing DNA damage. PMID:22624716

Electrically erasable non-volatile memory via electrochemical deposition of multifractal aggregates

NASA Astrophysics Data System (ADS)

West, William Clark

An electrically erasable non-volatile memory system based on the electrochemical deposition of Ag or Cu from a solid electrolyte is presented. This memory system, referred to as Metal Dendrite Memory, is characterized by its simplicity of design and operation, low power consumption, and potentially high cell density. By applying a small DC voltage (2.5-5V) across a Cu or Ag doped As-S amorphous chalcogenide film sandwiched between two metal electrodes, a metal filament can be electrodeposited, shorting the large impedance solid electrolyte ("on" state). Application of smaller amplitude voltage pulses (1-1.5V) across the metal filament ruptures the short, returning the cell to the high impedance state ("off" state). The state of the cell is read by applying very small amplitude voltage pulses (0.25V). These "read" voltage pulses do not disturb the state of the cell even after 10sp7 pulses. Due to difficulties in characterizing this solid electrolyte system via conventional techniques, the MDM cells have been examined using low excitation characterization methods such as Impedance Spectroscopy (IS) and polarization measurements. These studies have yielded a self-consistent equivalent circuit model as well as parameters such as ionic diffusivity and conductivity, double layer and geometric capacitances. In addition to materials characterization, the speed at which the MDM cells operate has been systematically studied using a series of statistically designed experiments, demonstrating the importance of photodoping time and applied voltage on device speed. These results were further examined using IS and Rutherford Backscattering Spectrometry (RBS). The morphology of the growing electrodeposit was studied in several different electrode arrangements and excitation conditions. Under migrationally limited conditions, the electrodeposit grew in multifractal patterns, as measured using lacunarity analysis. If a conducting film was deposited parallel to the growth direction, the electrodeposition could be driven from Diffusion Limited Aggregation (DLA) to Densely Branched Morphology (DBM) modes by changing the voltage applied to the cell. In summary, this study has laid the groundwork for future research and development of MDM memory systems by identifying many important characteristics of the MDM cell. These findings include quantitative measurement of ionic transport values, identification of the electrochemical mechanisms involved in MDM data storage, determination of parameters that are statistically significant in affecting data storage speed, and determination of the effect of cell geometry and bias on electrodeposit morphology.

Solar activities and Climate change hazards

NASA Astrophysics Data System (ADS)

Hady, A. A., II

2014-12-01

Throughout the geological history of Earth, climate change is one of the recurrent natural hazards. In recent history, the impact of man brought about additional climatic change. Solar activities have had notable effect on palaeoclimatic changes. Contemporary, both solar activities and building-up of green-house gases effect added to the climatic changes. This paper discusses if the global worming caused by the green-house gases effect will be equal or less than the global cooling resulting from the solar activities. In this respect, we refer to the Modern Dalton Minimum (MDM) which stated that starting from year 2005 for the next 40 years; the earth's surface temperature will become cooler than nowadays. However the degree of cooling, previously mentioned in old Dalton Minimum (c. 210 y ago), will be minimized by building-up of green-house gases effect during MDM period. Regarding to the periodicities of solar activities, it is clear that now we have a new solar cycle of around 210 years. Keywords: Solar activities; solar cycles; palaeoclimatic changes; Global cooling; Modern Dalton Minimum.

Prospective virtual screening for novel p53-MDM2 inhibitors using ultrafast shape recognition

NASA Astrophysics Data System (ADS)

Patil, Sachin P.; Ballester, Pedro J.; Kerezsi, Cassidy R.

2014-02-01

The p53 protein, known as the guardian of genome, is mutated or deleted in approximately 50 % of human tumors. In the rest of the cancers, p53 is expressed in its wild-type form, but its function is inhibited by direct binding with the murine double minute 2 (MDM2) protein. Therefore, inhibition of the p53-MDM2 interaction, leading to the activation of tumor suppressor p53 protein presents a fundamentally novel therapeutic strategy against several types of cancers. The present study utilized ultrafast shape recognition (USR), a virtual screening technique based on ligand-receptor 3D shape complementarity, to screen DrugBank database for novel p53-MDM2 inhibitors. Specifically, using 3D shape of one of the most potent crystal ligands of MDM2, MI-63, as the query molecule, six compounds were identified as potential p53-MDM2 inhibitors. These six USR hits were then subjected to molecular modeling investigations through flexible receptor docking followed by comparative binding energy analysis. These studies suggested a potential role of the USR-selected molecules as p53-MDM2 inhibitors. This was further supported by experimental tests showing that the treatment of human colon tumor cells with the top USR hit, telmisartan, led to a dose-dependent cell growth inhibition in a p53-dependent manner. It is noteworthy that telmisartan has a long history of safe human use as an approved anti-hypertension drug and thus may present an immediate clinical potential as a cancer therapeutic. Furthermore, it could also serve as a structurally-novel lead molecule for the development of more potent, small-molecule p53-MDM2 inhibitors against variety of cancers. Importantly, the present study demonstrates that the adopted USR-based virtual screening protocol is a useful tool for hit identification in the domain of small molecule p53-MDM2 inhibitors.

Ensemble-based virtual screening reveals dual-inhibitors for the p53-MDM2/MDMX interactions.

PubMed

Barakat, Khaled; Mane, Jonathan; Friesen, Douglas; Tuszynski, Jack

2010-02-26

The p53 protein, a guardian of the genome, is inactivated by mutations or deletions in approximately half of human tumors. While in the rest of human tumors, p53 is expressed in wild-type form, yet it is inhibited by over-expression of its cellular regulators MDM2 and MDMX proteins. Although the p53-binding sites within the MDMX and MDM2 proteins are closely related, known MDM2 small-molecule inhibitors have been shown experimentally not to bind to its homolog, MDMX. As a result, the activity of these inhibitors including Nutlin3 is compromised in tumor cells over-expressing MDMX, preventing these compounds from fully activating the p53 protein. Here, we applied the relaxed complex scheme (RCS) to allow for the full receptor flexibility in screening for dual-inhibitors that can mutually antagonize the two p53-regulator proteins. First, we filtered the NCI diversity set, DrugBank compounds and a derivative library for MDM2-inhibitors against 28 dominant MDM2-conformations. Then, we screened the MDM2 top hits against the binding site of p53 within the MDMX target. Results described herein identify a set of compounds that have been computationally predicted to ultimately activate the p53 pathway in tumor cells retaining the wild-type protein. Crown Copyright 2009. Published by Elsevier Inc. All rights reserved.

Fretting and Corrosion at the Backside of Modular Cobalt Chromium Acetabular Inserts: A Retrieval Analysis.

PubMed

Tarity, T David; Koch, Chelsea N; Burket, Jayme C; Wright, Timothy M; Westrich, Geoffrey H

2017-03-01

Adverse local tissue reaction formation has been suggested to occur with the Modular Dual Mobility (MDM) acetabular design. Few reports in the literature have evaluated fretting and corrosion damage between the acetabular shell and modular metal inserts in this modular system. We evaluated a series of 18 retrieved cobalt chromium MDM inserts for evidence of fretting and corrosion. We assessed the backsides of 18 MDM components for evidence of fretting and corrosion in polar and taper regions based on previously established methods. We collected and assessed 30 similarly designed modular inserts retrieved from metal-on-metal (MoM) total hip arthroplasties as a control. No specific pattern of fretting or corrosion was identified on the MDM inserts. Both fretting and corrosion were significantly greater in the MoM cohort than the MDM cohort, driven by higher fretting and corrosion scores in the engaged taper region of the MoM inserts. MoM components demonstrated more fretting and corrosion than MDM designs, specifically at the taper region, likely driven by differences in the taper engagement mechanism and geometry among the insert designs. The lack of significant fretting and corrosion observed in the MDM inserts are inconsistent with recent claims that this interface may produce clinically significant metallosis and adverse local tissue reactions. Copyright © 2016 Elsevier Inc. All rights reserved.

Glycogen synthase kinase 3β inhibitors protect hippocampal neurons from radiation-induced apoptosis by regulating MDM2-p53 pathway.

PubMed

Thotala, D K; Hallahan, D E; Yazlovitskaya, E M

2012-03-01

Exposure of the brain to ionizing radiation can cause neurocognitive deficiencies. The pathophysiology of these neurological changes is complex and includes radiation-induced apoptosis in the subgranular zone of the hippocampus. We have recently found that inhibition of glycogen synthase kinase 3β (GSK-3β) resulted in significant protection from radiation-induced apoptosis in hippocampal neurons. The molecular mechanisms of this cytoprotection include abrogation of radiation-induced accumulation of p53. Here we show that pretreatment of irradiated HT-22 hippocampal-derived neurons with small molecule inhibitors of GSK-3β SB216763 or SB415286, or with GSK-3β-specific shRNA resulted in accumulation of the p53-specific E3 ubiquitin ligase MDM2. Knockdown of MDM2 using specific shRNA or chemical inhibition of MDM2-p53 interaction prevented the protective changes triggered by GSK-3β inhibition in irradiated HT-22 neurons and restored radiation cytotoxicity. We found that this could be due to regulation of apoptosis by subcellular localization and interaction of GSK-3β, p53 and MDM2. These data suggest that the mechanisms of radioprotection by GSK-3β inhibitors in hippocampal neurons involve regulation of MDM2-dependent p53 accumulation and interactions between GSK-3β, MDM2 and p53.

Mdm-2 binding and TAF(II)31 recruitment is regulated by hydrogen bond disruption between the p53 residues Thr18 and Asp21.

PubMed

Jabbur, James R; Tabor, Amy D; Cheng, Xiaodong; Wang, Hua; Uesugi, Motonari; Lozano, Guillermina; Zhang, Wei

2002-10-10

Analyses of five wild-type p53 containing cell lines revealed lineage specific differences in phosphorylation of Thr18 after treatment with ionizing (IR) or ultraviolet (UV) radiation. Importantly, Thr18 phosphorylation correlated with induction of the p53 downstream targets p21(Waf1/Cip1) (p21) and Mdm-2, suggesting a transactivation enhancing role. Thr18 phosphorylation has been shown to abolish side-chain hydrogen bonding between Thr18 and Asp21, an interaction necessary for stabilizing alpha-helical conformation within the transactivation domain. Mutagenesis-derived hydrogen bond disruption attenuated the interaction of p53 with the transactivation repressor Mdm-2 but had no direct effect on the interaction of p53 with the basal transcription factor TAF(II)31. However, prior incubation of p53 mutants with Mdm-2 modulated TAF(II)31 interaction with p53, suggesting Mdm-2 blocks the accessibility of p53 to TAF(II)31. Consistently, p53-null cells transfected with hydrogen bond disrupting p53 mutants demonstrated enhanced endogenous p21 expression, whereas p53/Mdm-2-double null cells exhibited no discernible differences in p21 expression. We conclude disruption of intramolecular hydrogen bonding between Thr18 and Asp21 enhances p53 transactivation by modulating Mdm-2 binding, facilitating TAF(II)31 recruitment.

Diaryl- and triaryl-pyrrole derivatives: inhibitors of the MDM2-p53 and MDMX-p53 protein-protein interactions†Electronic supplementary information (ESI) available: Experimental details for compound synthesis, analytical data for all compounds and intermediates. Details for the biological evaluation. Further details for the modeling. Table of combustion analysis data. See DOI: 10.1039/c3md00161jClick here for additional data file.

PubMed

Blackburn, Tim J; Ahmed, Shafiq; Coxon, Christopher R; Liu, Junfeng; Lu, Xiaohong; Golding, Bernard T; Griffin, Roger J; Hutton, Claire; Newell, David R; Ojo, Stephen; Watson, Anna F; Zaytzev, Andrey; Zhao, Yan; Lunec, John; Hardcastle, Ian R

2013-09-21

Screening identified 2-(3-((4,6-dioxo-2-thioxotetrahydropyrimidin-5(2 H )-ylidene)methyl)-2,5-dimethyl-1 H -pyrrol-1-yl)-4,5,6,7-tetrahydrobenzo[ b ]thiophene-3-carbonitrile as an MDM2-p53 inhibitor (IC 50 = 12.3 μM). MDM2-p53 and MDMX-p53 activity was seen for 5-((1-(4-chlorophenyl)-2,5-diphenyl-1 H -pyrrol-3-yl)methylene)-2-thioxodihydropyrimidine-4,6(1 H ,5 H )-dione (MDM2 IC 50 = 0.11 μM; MDMX IC 50 = 4.2 μM) and 5-((1-(4-nitrophenyl)-2,5-diphenyl-1 H -pyrrol-3-yl)methylene)pyrimidine-2,4,6(1 H ,3 H ,5 H )-trione (MDM2 IC 50 = 0.15 μM; MDMX IC 50 = 4.2 μM), and cellular activity consistent with p53 activation in MDM2 amplified cells. Further SAR studies demonstrated the requirement for the triarylpyrrole moiety for MDMX-p53 activity but not for MDM2-p53 inhibition.

SAR405838: An optimized inhibitor of MDM2-p53 interaction that induces complete and durable tumor regression

DOE PAGES

Wang, Shaomeng; Sun, Wei; Zhao, Yujun; ...

2014-08-21

Blocking the MDM2-p53 protein-protein interaction has long been considered to offer a broad cancer therapeutic strategy, despite the potential risks of selecting tumors harboring p53 mutations that escape MDM2 control. In this study, we report a novel small molecule inhibitor of the MDM2-p53 interaction, SAR405838 (MI-77301) that has been advanced into Phase I clinical trials. SAR405838 binds to MDM2 with K i = 0.88 nM and has high specificity over other proteins. A co-crystal structure of the SAR405838:MDM2 complex shows that in addition to mimicking three key p53 amino acid residues, the inhibitor captures additional interactions not observed in themore » p53-MDM2 complex and induces refolding of the short, unstructured MDM2 N-terminal region to achieve its high affinity. SAR405838 effectively activates wild-type p53 in vitro and in xenograft tumor tissue of leukemia and solid tumors, leading to p53-dependent cell cycle arrest and/or apoptosis. At well-tolerated dose schedules, SAR405838 achieves either durable tumor regression or complete tumor growth inhibition in mouse xenograft models of SJSA-1 osteosarcoma, RS4;11 acute leukemia, LNCaP prostate cancer and HCT-116 colon cancer. Remarkably, a single oral dose of SAR405838 is sufficient to achieve complete tumor regression in the SJSA-1 model. Mechanistically, robust transcriptional up-regulation of PUMA induced by SAR405838 results in strong apoptosis in tumor tissue, leading to complete tumor regression. Lastly, our findings provide a preclinical basis upon which to evaluate SAR405838 as a therapeutic agent in patients whose tumors retain wild-type p53.« less

Discovery of novel dual inhibitors against Mdm2 and Mdmx proteins by in silico approaches and binding assay.

PubMed

Golestanian, Sahand; Sharifi, Amirhossein; Popowicz, Grzegorz M; Azizian, Homa; Foroumadi, Alireza; Szwagierczak, Aleksandra; Holak, Tad A; Amanlou, Massoud

2016-01-15

The p53 protein, also called guardian of the genome, has a key role in cell cycle regulation. It is activated under stressful circumstances, such as DNA damage which results in permanent arrest or cell death. The protein is disabled in several types of human cancer due to over-expression of the two regulators, Mdm2 and Mdmx. As a result, inhibiting Mdm subtypes could reactivate p53 and bring about a promising therapeutic strategy in cancers. Here a structure-based pharmacophore search and docking simulation are presented in order to filter our in-house library which contains 1035 compounds to find novel scaffolds that inhibit Mdm2 and Mdmx concomitantly. Afterwards, fluorescence polarization binding assay was used to obtain inhibition constant of final compounds. Thirty two ligands were introduced to bioassay as a result of in-silico methods. Twelve of them inhibit both proteins with almost balanced Ki value ranging from 18 to 162μM for Mdm2 and 18 to 233μM for Mdmx. It was observed that all compounds fill Phe19 and Trp23 pockets of Mdm2/x binding sites and form a hydrogen bond with Trp23 pocket's neighbor amino acids in a manner similar to p53 protein. Additionally, it was concluded that Trp23 pocket of Mdmx has a bigger hydrophobic volume comparing with the one of Mdm2. Three structure-activity relationship patterns are supposed which one of them presents usefulness features and can be used in future studies. This study presents first qualitative SAR for dual inhibitors against Mdm2/x. Copyright © 2016 Elsevier Inc. All rights reserved.

Effect of phorbol esters on the macrophage-mediated biodegradation of polyurethanes via protein kinase C activation and other pathways.

PubMed

McBane, Joanne Eileen; Santerre, J P; Labow, Rosalind

2009-01-01

It was previously found that re-seeding monocyte-derived macrophages (MDM) on polycarbonate-based polyurethanes (PCNUs) in the presence of the protein kinase C (PKC) activator phorbol myristate acetate (PMA) inhibited MDM-mediated degradation of PCNUs synthesized with 1,6-hexane diisocyanate (HDI), as well as esterase activity and monocyte-specific esterase (MSE) protein. However, no effect on the degradation of a 4,4'-methylene bisphenyl (MDI)-derived PCNU (MDI321) occurred. This finding suggested that oxidation, a process linked to the PKC pathway, was not activated in the same manner for all PCNUs. In the current study MDM were re-seeded onto the above PCNU surfaces with PMA, PKC-inactive 4alphaPMA and the PKC inhibitor bisindolylmaleimide I hydrochloride (BIM) for 48 h before assaying for PCNU degradation, esterase activity, MSE protein, DNA, cell viability and cell morphology. 4alphaPMA did not alter MDM-mediated HDI PCNU degradation but MDI321 degradation increased in this condition. BIM alone had no effect on any parameter; however, when BIM and PMA were added together, the PMA inhibition of biodegradation, esterase activity and MSE protein was partially reversed for MDM on HDI PCNUs only. Adding PMA to MDM on HDI PCNUs increased intercellular connections, whereas 4alphaPMA or BIM+PMA increased cell size. Although this study demonstrated a role for oxidation via a PKC-activated pathway in MDM-mediated PCNU degradation, phorbol esters appear to also activate non-PKC pathways that have roles in biodegradation. Moreover, the sensitivity to material surface chemistry in the MDM response to each PCNU dictates a multi-factorial degradative process involving alternate material specific oxidative and hydrolytic mechanisms.

vif-negative human immunodeficiency virus type 1 persistently replicates in primary macrophages, producing attenuated progeny virus.

PubMed Central

Chowdhury, I H; Chao, W; Potash, M J; Sova, P; Gendelman, H E; Volsky, D J

1996-01-01

The vif gene of human immunodeficiency virus type 1 (HIV-1) is required for efficient infection of primary T lymphocytes. In this study, we investigated in detail the role of vif in productive infection of primary monocyte-derived macrophages (MDM). Viruses carrying missense or deletion mutations in vif were constructed on the background of the monocytotropic recombinant NLHXADA-GP. Using MDM from multiple donors, we found that vif mutants produced in complementing or partially complementing cell lines were approximately 10% as infectious as wild-type virus when assayed for incomplete, complete, and circularized viral DNA molecules by quantitative PCR amplification or for viral core antigen p24 production by enzyme-linked immunosorbent assay. We then determined the structure and infectivity of vif mutant HIV-1 by using MDM exclusively both for virus production and as targets for infection. Biosynthetic labeling and immunoprecipitation analysis of sucrose cushion-purified vif-negative HIV-1 made in MDM revealed that the virus had reduced p24 content compared with wild-type HIV-1. Cell-free MDM-derived vif mutant HIV-1 was infectious in macrophages as determined by the synthesis and maintenance of full-length viral DNA and by the produc- tion of particle-associated viral RNA, but its infectivity was approximately 2,500-fold lower than that of wild-type virus whose titer was determined in parallel by measurement of the viral DNA burden. MDM infected with MDM-derived vif-negative HIV-1 were able to transmit the virus to uninfected MDM by cocultivation, confirming the infectiousness of this virus. We conclude that mutations in vif significantly reduce but do not eliminate the capacity of HIV-1 to replicate and produce infectious progeny virus in primary human macrophages. PMID:8764044

vif-negative human immunodeficiency virus type 1 persistently replicates in primary macrophages, producing attenuated progeny virus.

PubMed

Chowdhury, I H; Chao, W; Potash, M J; Sova, P; Gendelman, H E; Volsky, D J

1996-08-01

The vif gene of human immunodeficiency virus type 1 (HIV-1) is required for efficient infection of primary T lymphocytes. In this study, we investigated in detail the role of vif in productive infection of primary monocyte-derived macrophages (MDM). Viruses carrying missense or deletion mutations in vif were constructed on the background of the monocytotropic recombinant NLHXADA-GP. Using MDM from multiple donors, we found that vif mutants produced in complementing or partially complementing cell lines were approximately 10% as infectious as wild-type virus when assayed for incomplete, complete, and circularized viral DNA molecules by quantitative PCR amplification or for viral core antigen p24 production by enzyme-linked immunosorbent assay. We then determined the structure and infectivity of vif mutant HIV-1 by using MDM exclusively both for virus production and as targets for infection. Biosynthetic labeling and immunoprecipitation analysis of sucrose cushion-purified vif-negative HIV-1 made in MDM revealed that the virus had reduced p24 content compared with wild-type HIV-1. Cell-free MDM-derived vif mutant HIV-1 was infectious in macrophages as determined by the synthesis and maintenance of full-length viral DNA and by the produc- tion of particle-associated viral RNA, but its infectivity was approximately 2,500-fold lower than that of wild-type virus whose titer was determined in parallel by measurement of the viral DNA burden. MDM infected with MDM-derived vif-negative HIV-1 were able to transmit the virus to uninfected MDM by cocultivation, confirming the infectiousness of this virus. We conclude that mutations in vif significantly reduce but do not eliminate the capacity of HIV-1 to replicate and produce infectious progeny virus in primary human macrophages.

Reactivating TP53 signaling by the novel MDM2 inhibitor DS-3032b as a therapeutic option for high-risk neuroblastoma

PubMed Central

Arnhold, Viktor; Schmelz, Karin; Proba, Jutta; Winkler, Annika; Wünschel, Jasmin; Toedling, Joern; Deubzer, Hedwig E.; Künkele, Annette; Eggert, Angelika; Schulte, Johannes H.; Hundsdoerfer, Patrick

2018-01-01

Fewer than 50% of patients with high-risk neuroblastoma survive five years after diagnosis with current treatment protocols. Molecular targeted therapies are expected to improve survival. Although MDM2 has been validated as a promising target in preclinical models, no MDM2 inhibitors have yet entered clinical trials for neuroblastoma patients. Toxic side effects, poor bioavailability and low efficacy of the available MDM2 inhibitors that have entered phase I/II trials drive the development of novel MDM2 inhibitors with an improved risk-benefit profile. We investigated the effect of the novel MDM2 small molecular inhibitor, DS-3032b, on viability, proliferation, senescence, migration, cell cycle arrest and apoptosis in a panel of six neuroblastoma cell lines with different TP53 and MYCN genetic backgrounds, and assessed efficacy in a murine subcutaneous model for high-risk neuroblastoma. Re-analysis of existing expression data from 476 primary neuroblastomas showed that high-level MDM2 expression correlated with poor patient survival. DS-3032b treatment enhanced TP53 target gene expression and induced G1 cell cycle arrest, senescence and apoptosis. CRISPR-mediated MDM2 knockout in neuroblastoma cells mimicked DS-3032b treatment. TP53 signaling was selectively activated by DS-3032b in neuroblastoma cells with wildtype TP53, regardless of the presence of MYCN amplification, but was significantly reduced by TP53 mutations or expression of a dominant-negative TP53 mutant. Oral DS-3032b administration inhibited xenograft tumor growth and prolonged mouse survival. Our in vitro and in vivo data demonstrate that DS-3032b reactivates TP53 signaling even in the presence of MYCN amplification in neuroblastoma cells, to reduce proliferative capacity and cause cytotoxicity. PMID:29416773

ATM-dependent phosphorylation of Mdm2 on serine 395: role in p53 activation by DNA damage

PubMed Central

Maya, Ruth; Balass, Moshe; Kim, Seong-Tae; Shkedy, Dganit; Leal, Juan-Fernando Martinez; Shifman, Ohad; Moas, Miri; Buschmann, Thomas; Ronai, Ze'ev; Shiloh, Yosef; Kastan, Michael B.; Katzir, Ephraim; Oren, Moshe

2001-01-01

The p53 tumor suppressor protein, a key regulator of cellular responses to genotoxic stress, is stabilized and activated after DNA damage. The rapid activation of p53 by ionizing radiation and radiomimetic agents is largely dependent on the ATM kinase. p53 is phosphorylated by ATM shortly after DNA damage, resulting in enhanced stability and activity of p53. The Mdm2 oncoprotein is a pivotal negative regulator of p53. In response to ionizing radiation and radiomimetic drugs, Mdm2 undergoes rapid ATM-dependent phosphorylation prior to p53 accumulation. This results in a decrease in its reactivity with the 2A10 monoclonal antibody. Phage display analysis identified a consensus 2A10 recognition sequence, possessing the core motif DYS. Unexpectedly, this motif appears twice within the human Mdm2 molecule, at positions corresponding to residues 258–260 and 393–395. Both putative 2A10 epitopes are highly conserved and encompass potential phosphorylation sites. Serine 395, residing within the carboxy-terminal 2A10 epitope, is the major target on Mdm2 for phosphorylation by ATM in vitro. Mutational analysis supports the conclusion that Mdm2 undergoes ATM-dependent phosphorylation on serine 395 in vivo in response to DNA damage. The data further suggests that phosphorylated Mdm2 may be less capable of promoting the nucleo-cytoplasmic shuttling of p53 and its subsequent degradation, thereby enabling p53 accumulation. Our findings imply that activation of p53 by DNA damage is achieved, in part, through attenuation of the p53-inhibitory potential of Mdm2. PMID:11331603

One night of sleep is insufficient to achieve sleep-to-forget emotional decontextualisation processes.

PubMed

Deliens, Gaétane; Peigneux, Philippe

2014-01-01

Neutral memories unbind from their emotional acquisition context when sleep is allowed the night after learning and testing takes place after two additional nights of sleep. However, mood-dependent memory (MDM) effects are not abolished after a restricted sleep episode mostly featuring non rapid-eye-movement (NREM) or rapid-eye-movement (REM) sleep. Here, we tested whether (1) one night of sleep featuring several NREM-REM sleep cycles is sufficient to suppress MDM effects and (2) a neutral mood is a sufficiently contrasting state to induce MDM effects, i.e. interfere with the recall of information learned in happy or sad states. Results disclosed MDM effects both in the post-learning sleep and wake conditions, with better recall in congruent than incongruent emotional contexts. Our findings suggest that the emotional unbinding needs several consecutive nights of sleep to be complete, and that even subtle mood changes are sufficient to produce MDM effects.

Polymorphism of MDM2 promoter 309 (rs 2279744) and the risk of PCOS.

PubMed

Chan, Ying; Jiang, Hongguo; Yang, Xiaoling; Li, Dongya; Ma, Lan; Luo, Ying; Tang, Wenru

2016-01-01

This study aimed at evaluating possible association between MDM2 SNP309 polymorphism (rs 2279744) and polycystic ovary syndrome (PCOS). One hundred and twenty-five women with PCOS and two hundred and fifty women without PCOS were collected from the department of reproductive medicine of college hospital in this case-control study. Peripheral blood samples were collected from all participants and DNA was extracted, MDM2 SNP309 polymorphism (rs 2279744) was determined from the 125 cases and 250 controls. Women were grouped into PCOS (n = 125) group and control group (n = 250). Odds ratios (OR) and 95% confidence intervals (CI) were used to evaluate the association between MDM2 SNP309 polymorphism (rs 2279744) and PCOS. The distribution of T allele was significant higher in PCOS cases than controls. MDM2 SNP 309 T allele is associated with PCOS.

Convergent solid-phase and solution approaches in the synthesis of the cysteine-rich Mdm2 RING finger domain.

PubMed

Vasileiou, Zoe; Barlos, Kostas; Gatos, Dimitrios

2009-12-01

The RING finger domain of the Mdm2, located at the C-terminus of the protein, is necessary for regulation of p53, a tumor suppressor protein. The 48-residues long Mdm2 peptide is an important target for studying its interaction with small anticancer drug candidates. For the chemical synthesis of the Mdm2 RING finger domain, the fragment condensation on solid-phase and the fragment condensation in solution were studied. The latter method was performed using either protected or free peptides at the C-terminus as the amino component. Best results were achieved using solution condensation where the N-component was applied with the C-terminal carboxyl group left unprotected. The developed method is well suited for large-scale synthesis of Mdm2 RING finger domain, combining the advantages of both solid-phase and solution synthesis. (c) 2009 European Peptide Society and John Wiley & Sons, Ltd.

NASA Communications Division (NASCOM) Tracking and Data Relay Satellite System (TDRSS) shuttle multiplexer-demultiplexer data system (MDM) and supporting items

NASA Technical Reports Server (NTRS)

New, S. R.

1981-01-01

The multiplexer-demultiplexer (MDM) project included the design, documentation, manufacture, and testing of three MDM Data Systems. The equipment is contained in 59 racks, and includes more than 3,000 circuit boards and 600 microprocessors. Spares, circuit card testers, a master set of programmable integrated circuits, and a program development system were included as deliverables. All three MDM's were installed, and were operationally tested. The systems performed well with no major problems. The progress and problems analysis, addresses schedule conformance, new technology, items awaiting government approval, and project conclusions are summarized. All contract modifications are described.

NASA Communications Division (NASCOM) Tracking and Data Relay Satellite System (TDRSS) shuttle multiplexer-demultiplexer data system (MDM) and supporting items

NASA Astrophysics Data System (ADS)

New, S. R.

1981-06-01

The multiplexer-demultiplexer (MDM) project included the design, documentation, manufacture, and testing of three MDM Data Systems. The equipment is contained in 59 racks, and includes more than 3,000 circuit boards and 600 microprocessors. Spares, circuit card testers, a master set of programmable integrated circuits, and a program development system were included as deliverables. All three MDM's were installed, and were operationally tested. The systems performed well with no major problems. The progress and problems analysis, addresses schedule conformance, new technology, items awaiting government approval, and project conclusions are summarized. All contract modifications are described.

Computational Studies of Difference in Binding Modes of Peptide and Non-Peptide Inhibitors to MDM2/MDMX Based on Molecular Dynamics Simulations

PubMed Central

Chen, Jianzhong; Zhang, Dinglin; Zhang, Yuxin; Li, Guohui

2012-01-01

Inhibition of p53-MDM2/MDMX interaction is considered to be a promising strategy for anticancer drug design to activate wild-type p53 in tumors. We carry out molecular dynamics (MD) simulations to study the binding mechanisms of peptide and non-peptide inhibitors to MDM2/MDMX. The rank of binding free energies calculated by molecular mechanics generalized Born surface area (MM-GBSA) method agrees with one of the experimental values. The results suggest that van der Waals energy drives two kinds of inhibitors to MDM2/MDMX. We also find that the peptide inhibitors can produce more interaction contacts with MDM2/MDMX than the non-peptide inhibitors. Binding mode predictions based on the inhibitor-residue interactions show that the π–π, CH–π and CH–CH interactions dominated by shape complimentarity, govern the binding of the inhibitors in the hydrophobic cleft of MDM2/MDMX. Our studies confirm the residue Tyr99 in MDMX can generate a steric clash with the inhibitors due to energy and structure. This finding may theoretically provide help to develop potent dual-specific or MDMX inhibitors. PMID:22408446

Channel estimation in few mode fiber mode division multiplexing transmission system

NASA Astrophysics Data System (ADS)

Hei, Yongqiang; Li, Li; Li, Wentao; Li, Xiaohui; Shi, Guangming

2018-03-01

It is abundantly clear that obtaining the channel state information (CSI) is of great importance for the equalization and detection in coherence receivers. However, to the best of the authors' knowledge, in most of the existing literatures, CSI is assumed to be perfectly known at the receiver. So far, few literature discusses the effects of imperfect CSI on MDM system performance caused by channel estimation. Motivated by that, in this paper, the channel estimation in few mode fiber (FMF) mode division multiplexing (MDM) system is investigated, in which two classical channel estimation methods, i.e., least square (LS) method and minimum mean square error (MMSE) method, are discussed with the assumption of the spatially white noise lumped at the receiver side of MDM system. Both the capacity and BER performance of MDM system affected by mode-dependent gain or loss (MDL) with different channel estimation errors have been studied. Simulation results show that the capacity and BER performance can be further deteriorated in MDM system by the channel estimation, and an 1e-3 variance of channel estimation error is acceptable in MDM system with 0-6 dB MDL values.

Real-time polymerase chain reaction analysis of MDM2 and CDK4 expression using total RNA from core-needle biopsies is useful for diagnosing adipocytic tumors

PubMed Central

2014-01-01

Background Diagnosing adipocytic tumors can be challenging because it is often difficult to morphologically distinguish between benign, intermediate and malignant adipocytic tumors, and other sarcomas that are histologically similar. Recently, a number of tumor-specific chromosome translocations and associated fusion genes have been identified in adipocytic tumors and atypical lipomatous tumors/well-differentiated liposarcomas (ALT/WDL), which have a supernumerary ring and/or giant chromosome marker with amplified sequences of the MDM2 and CDK4 genes. The purpose of this study was to investigate whether quantitative real-time polymerase chain reaction (PCR) could be used to amplify MDM2 and CDK4 from total RNA samples obtained from core-needle biopsy sections for the diagnosis of ALT/WDL. Methods A series of lipoma (n = 124) and ALT/WDL (n = 44) cases were analyzed for cytogenetic analysis and lipoma fusion genes, as well as for MDM2 and CDK4 expression by real-time PCR. Moreover, the expression of MDM2 and CDK4 in whole tissue sections was compared with that in core-needle biopsy sections of the same tumor in order to determine whether real-time PCR could be used to distinguish ALT/WDL from lipoma at the preoperative stage. Results In whole tissue sections, the medians for MDM2 and CDK4 expression in ALT/WDL were higher than those in the lipomas (P < 0.05). Moreover, karyotype subdivisions with rings and/or giant chromosomes had higher MDM2 and CDK4 expression levels compared to karyotypes with 12q13-15 rearrangements, other abnormal karyotypes, and normal karyotypes (P < 0.05). On the other hand, MDM2 and CDK4 expression levels in core-needle biopsy sections were similar to those in whole-tissue sections (MDM2: P = 0.6, CDK4: P = 0.8, Wilcoxon signed-rank test). Conclusion Quantitative real-time PCR of total RNA can be used to evaluate the MDM2 and CDK4 expression levels in core-needle biopsies and may be useful for distinguishing ALT/WDL from adipocytic tumors. Thus, total RNA from core-needle biopsy sections may have potential as a routine diagnostic tool for other tumors where gene overexpression is a feature of the tumor. PMID:24965044

HIV-1-based defective lentiviral vectors efficiently transduce human monocytes-derived macrophages and suppress replication of wild-type HIV-1

PubMed Central

Zeng, Lingbing; Planelles, Vicente; Sui, Ziye; Gartner, Suzanne; Maggirwar, Sanjay B.; Dewhurst, Stephen; Ye, Linbai; Nerurkar, Vivek R.; Yanagihara, Richard; Lu, Yuanan

2010-01-01

Background Human monocytes play an important role in mediating human immunodeficiency virus type 1 (HIV-1) infection of the central nervous system (CNS), and monocytes-derived macrophages (MDM) represent a major viral reservoir within the brain and other target organs. Current gene transduction of MDM is hindered by a limited efficiency. In this study we established a lentiviral vector-based technique for improved gene transfer into human MDM cultures in vitro and demonstrated significant protection of transduced MDM from super-infection with wild-type HIV-1. Methods HIV-1-based lentiviral vector stocks were prepared in 293T cells by the established calcium phosphate transfection method. Human monocytes were isolated from donors' blood by Ficoll-Paque separation and cultured in vitro. To establish an effective technique for vector-mediated gene transfer, primary cultures of human MDM were transduced at varying multiplicities of infection (MOI) and at a range of time points following initial isolation of cells (time-in-culture). Transduced cells were then examined for transgene (green fluorescent protein (GFP)) expression by fluorescent microscopy and reverse transcription polymerase chain reaction (RT-PCR). These cultures were then exposed to wild-type HIV-1, and viral replication was quantitated by p24 assay; production of neurotoxic effector molecules by the transduced MDM was also examined, using indicator neurons. Results We have demonstrated that primary human MDM could be efficiently transduced (>50%) with concentrated HIV-1-based defective lentiviral vectors (DLV). Furthermore, DLV-mediated gene transduction was stable, and the transduced cells exhibited no apparent difference from normal MDM in terms of their morphology, viability and neurotoxin secretion. Challenge of DLV-transduced MDM cultures with HIV-1Ba-L revealed a 4- to 5-fold reduction in viral replication, as measured by p24 antigen production. This effect was associated with the mobilization of the GFP-expressing DLV construct by the wild-type virus. Conclusions These data demonstrate the inhibition of HIV-1 replication in primary MDM, by a DLV vector that lacks any anti-HIV-1 transgene. These findings lay the initial groundwork for future studies on the ability of DLV-modified monocytes to introduce anti-HIV-1 genes into the CNS. Lentiviral vector-mediated gene delivery to the CNS by monocytes/macrophages is a promising, emerging strategy for treating neuro-AIDS. PMID:16142830

Molecular Recognition of Methyl α-d-Mannopyranoside by Antifreeze (Glyco)Proteins

PubMed Central

2015-01-01

Antifreeze proteins and glycoproteins [AF(G)Ps] have been well-known for more than three decades for their ability to inhibit the growth and recrystallization of ice through binding to specific ice crystal faces, and they show remarkable structural compatibility with specific ice crystal faces. Here, we show that the crystal growth faces of methyl α-d-mannopyranoside (MDM), a representative pyranose sugar, also show noteworthy structural compatibility with the known periodicities of AF(G)Ps. We selected fish AFGPs (AFGP8, AFGP1–5), and a beetle AFP (DAFP1) with increasing antifreeze activity as potential additives for controlling MDM crystal growth. Similar to their effects on ice growth, the AF(G)Ps can inhibit MDM crystal growth and recrystallization, and more significantly, the effectiveness for the AF(G)Ps are well correlated with their antifreeze activity. MDM crystals grown in the presence of AF(G)Ps are smaller and have better defined shapes and are of higher quality as indicated by single crystal X-ray diffraction and polarized microscopy than control crystals, but no new polymorphs of MDM were identified by single crystal X-ray diffraction, solid-state NMR, and attenuated total reflectance infrared spectroscopy. The observed changes in the average sizes of the MDM crystals can be related to the changes in the number of the MDM nuclei in the presence of the AF(G)Ps. The critical free energy change differences of the MDM nucleation in the absence and presence of the additives were calculated. These values are close to those of the ice nucleation in the presence of AF(G)Ps suggesting similar interactions are involved in the molecular recognition of MDM by the AF(G)Ps. To our knowledge this is the first report where AF(G)Ps have been used to control crystal growth of carbohydrates and on AFGPs controlling non-ice-like crystals. Our finding suggests MDM might be a possible alternative to ice for studying the detailed mechanism of AF(G)P–crystal interactions. The relationships between AF(G)Ps and carbohydrate binding proteins are also discussed. The structural compatibility between AF(G)Ps and growing crystal faces demonstrated herein adds to the repertoire of molecular recognition by AF(G)Ps, which may have potential applications in the sugar, food, pharmaceutical, and materials industries. PMID:24918258

Lack of association of the TP53 Arg72Pro SNP and the MDM2 SNP309 with systemic lupus erythematosus in Caucasian, African American, and Asian children and adults.

PubMed

Onel, K B; Huo, D; Hastings, D; Fryer-Biggs, J; Crow, M K; Onel, K

2009-01-01

The p53 tumour suppressor is the central regulator of apoptosis. Previously, the functional TP53 Arg72Pro polymorphism was found to be associated with systemic lupus erythematosus (SLE) in Koreans but not Spaniards. MDM2 is the major negative regulator of p53. An intronic polymorphism in MDM2, the SNP309, attenuates p53 activity and is associated with accelerated tumour development in premenopausal women. Polymorphic variation in MDM2 has never been studied in SLE. The aim of this study is to further assess the contribution of p53-pathway genetic variation to SLE by testing the association of the TP53 Arg72Pro polymorphism and the MDM2 SNP309 with SLE in a well-characterised and ethnically diverse cohort of patients with both childhood- and adult-onset SLE (n = 314). No association was found between the TP53 Arg72Pro polymorphism and SLE in patients of European descent, Asian descent or in African Americans, nor was an association found between the MDM2 SNP309 and SLE in patients of European descent or in African Americans. In addition, there was no correlation between either variant and early-onset disease or nephritis, an index of severe disease. It is concluded that neither the TP53 Arg72Pro polymorphism nor the MDM2 SNP309 contributes significantly to either susceptibility or disease severity in SLE.

Estradiol shows anti-skin cancer activities through decreasing MDM2 expression.

PubMed

Li, Li; Feng, Jianguo; Chen, Ying; Li, Shun; Ou, Mengting; Sun, Weichao; Tang, Liling

2017-01-31

Estradiol plays important roles in many biological responses inducing tumor genesis and cancer treatment. However, the effects of estradiol on tumors were inconsistent among a lot of researches and the mechanism is not fully understood. Our previous study indicated that splicing factor hnRNPA1 could bind to the human homologue of mouse double minute (MDM2), an oncogene which has been observed to be over-expressed in numerous types of cancers. In this research, we investigated whether and how estradiol correlate to cancer cell behaviors through heterogeneous nuclear ribonucleoprotein (hnRNPA1) and MDM2. Results showed that 10×10-13Mestradiol elevated the expression of hnRNPA1 regardless ER expression in cells, and then down-regulated the expression of MDM2. At the same time, estradiol inhibited cell proliferation, migration and epithelial-mesenchymal transition progression of A375 and GLL19 cells. While, knocking down hnRNPA1 through the transfection of hnRNPA1 siRNA led to the increase of MDM2 at both protein level and gene level In vivo experiment, subcutaneous injection with estradiol every two days near the tumor at doses of 2.5mg/kg/d suppressed tumor growth and reduced MDM2 expression. In a word, via increasing hnRNPA1 level and then reducing the expression of MDM2, estradiol prevented carcinogenesis in melanomas. We confirmed therapeutic effect of estradiol, as well as a new way for estradiol to resist skin cancer.

Induction of the 5S RNP-Mdm2-p53 ribosomal stress pathway delays the initiation but fails to eradicate established murine acute myeloid leukemia.

PubMed

Jaako, P; Ugale, A; Wahlestedt, M; Velasco-Hernandez, T; Cammenga, J; Lindström, M S; Bryder, D

2017-01-01

Mutations resulting in constitutive activation of signaling pathways that regulate ribosome biogenesis are among the most common genetic events in acute myeloid leukemia (AML). However, whether ribosome biogenesis presents as a therapeutic target to treat AML remains unexplored. Perturbations in ribosome biogenesis trigger the 5S ribonucleoprotein particle (RNP)-Mdm2-p53 ribosomal stress pathway, and induction of this pathway has been shown to have therapeutic efficacy in Myc-driven lymphoma. In the current study we address the physiological and therapeutic role of the 5S RNP-Mdm2-p53 pathway in AML. By utilizing mice that have defective ribosome biogenesis due to downregulation of ribosomal protein S19 (Rps19), we demonstrate that induction of the 5S RNP-Mdm2-p53 pathway significantly delays the initiation of AML. However, even a severe Rps19 deficiency that normally results in acute bone marrow failure has no consistent efficacy on already established disease. Finally, by using mice that harbor a mutation in the Mdm2 gene disrupting its binding to 5S RNP, we show that loss of the 5S RNP-Mdm2-p53 pathway is dispensable for development of AML. Our study suggests that induction of the 5S RNP-Mdm2-p53 ribosomal stress pathway holds limited potential as a single-agent therapy in the treatment of AML.

Monitoring p53 by MDM2 and MDMX is required for endocrine pancreas development and function in a spatio-temporal manner.

PubMed

Zhang, Yiwei; Zeng, Shelya X; Hao, Qian; Lu, Hua

2017-03-01

Although p53 is not essential for normal embryonic development, it plays a pivotal role in many biological and pathological processes, including cell fate determination-dependent and independent events and diseases. The expression and activity of p53 largely depend on its two biological inhibitors, MDM2 and MDMX, which have been shown to form a complex in order to tightly control p53 to an undetectable level during early stages of embryonic development. However, more delicate studies using conditional gene-modification mouse models show that MDM2 and MDMX may function separately or synergistically on p53 regulation during later stages of embryonic development and adulthood in a cell and tissue-specific manner. Here, we report the role of the MDM2/MDMX-p53 pathway in pancreatic islet morphogenesis and functional maintenance, using mouse lines with specific deletion of MDM2 or MDMX in pancreatic endocrine progenitor cells. Interestingly, deletion of MDM2 results in defects of embryonic endocrine pancreas development, followed by neonatal hyperglycemia and lethality, by inducing pancreatic progenitor cell apoptosis and inhibiting cell proliferation. However, unlike MDM2-knockout animals, mice lacking MDMX in endocrine progenitor cells develop normally. But, surprisingly, the survival rate of adult MDMX-knockout mice drastically declines compared to control mice, as blockage of neonatal development of endocrine pancreas by inhibition of cell proliferation and subsequent islet dysfunction and hyperglycemia eventually lead to type 1 diabetes-like disease with advanced diabetic nephropathy. As expected, both MDM2 and MDMX deletion-caused pancreatic defects are completely rescued by loss of p53, verifying the crucial role of the MDM2 and/or MDMX in regulating p53 in a spatio-temporal manner during the development, functional maintenance, and related disease progress of endocrine pancreas. Also, our study suggests a possible mouse model of advanced diabetic nephropathy, which is complementary to other established diabetic models and perhaps useful for the development of anti-diabetes therapies. Copyright © 2017 Elsevier Inc. All rights reserved.

Monolithically mode division multiplexing photonic integrated circuit for large-capacity optical interconnection.

PubMed

Chen, Guanyu; Yu, Yu; Zhang, Xinliang

2016-08-01

We propose and fabricate an on-chip mode division multiplexed (MDM) photonic interconnection system. Such a monolithically photonic integrated circuit (PIC) is composed of a grating coupler, two micro-ring modulators, mode multiplexer/demultiplexer, and two germanium photodetectors. The signals' generation, multiplexing, transmission, demultiplexing, and detection are successfully demonstrated on the same chip. Twenty Gb/s MDM signals are successfully processed with clear and open eye diagrams, validating the feasibility of the proposed circuit. The measured power penalties show a good performance of the MDM link. The proposed on-chip MDM system can be potentially used for large-capacity optical interconnection in future high-performance computers and big data centers.

Modified dark matter: Relating dark energy, dark matter and baryonic matter

NASA Astrophysics Data System (ADS)

Edmonds, Douglas; Farrah, Duncan; Minic, Djordje; Ng, Y. Jack; Takeuchi, Tatsu

Modified dark matter (MDM) is a phenomenological model of dark matter, inspired by gravitational thermodynamics. For an accelerating universe with positive cosmological constant (Λ), such phenomenological considerations lead to the emergence of a critical acceleration parameter related to Λ. Such a critical acceleration is an effective phenomenological manifestation of MDM, and it is found in correlations between dark matter and baryonic matter in galaxy rotation curves. The resulting MDM mass profiles, which are sensitive to Λ, are consistent with observational data at both the galactic and cluster scales. In particular, the same critical acceleration appears both in the galactic and cluster data fits based on MDM. Furthermore, using some robust qualitative arguments, MDM appears to work well on cosmological scales, even though quantitative studies are still lacking. Finally, we comment on certain nonlocal aspects of the quanta of modified dark matter, which may lead to novel nonparticle phenomenology and which may explain why, so far, dark matter detection experiments have failed to detect dark matter particles.

Broadband and fabrication-tolerant on-chip scalable mode-division multiplexing based on mode-evolution counter-tapered couplers.

PubMed

Wang, Jing; Xuan, Yi; Qi, Minghao; Huang, Haiyang; Li, You; Li, Ming; Chen, Xin; Sheng, Zhen; Wu, Aimin; Li, Wei; Wang, Xi; Zou, Shichang; Gan, Fuwan

2015-05-01

A broadband and fabrication-tolerant on-chip scalable mode-division multiplexing (MDM) scheme based on mode-evolution counter-tapered couplers is designed and experimentally demonstrated on a silicon-on-insulator (SOI) platform. Due to the broadband advantage offered by mode evolution, the two-mode MDM link exhibits a very large, -1  dB bandwidth of >180  nm, which is considerably larger than most of the previously reported MDM links whether they are based on mode-interference or evolution. In addition, the performance metrics remain stable for large-device width deviations from the designed valued by -60  nm to 40 nm, and for temperature variations from -25°C to 75°C. This MDM scheme can be readily extended to higher-order mode multiplexing and a three-mode MDM link is measured with less than -10  dB crosstalk from 1.46 to 1.64 μm wavelength range.

A comparison of in-cloud HCl concentrations from the NASA/MSFC MDM to measurements for the space shuttle launch

NASA Technical Reports Server (NTRS)

Glasser, M. E.

1981-01-01

The Multilevel Diffusion Model (MDM) Version 5 was modified to include features of more recent versions. The MDM was used to predict in-cloud HCl concentrations for the April 12 launch of the space Shuttle (STS-1). The maximum centerline predictions were compared with measurements of maximum gaseous HCl obtained from aircraft passes through two segments of the fragmented shuttle ground cloud. The model over-predicted the maximum values for gaseous HCl in the lower cloud segment and portrayed the same rate of decay with time as the observed values. However, the decay with time of HCl maximum predicted by the MDM was more rapid than the observed decay for the higher cloud segment, causing the model to under-predict concentrations which were measured late in the life of the cloud. The causes of the tendency for the MDM to be conservative in over-estimating the HCl concentrations in the one case while tending to under-predict concentrations in the other case are discussed.

Electrical characterization of gold-DNA-gold structures in presence of an external magnetic field by means of I-V curve analysis.

PubMed

Khatir, Nadia Mahmoudi; Banihashemian, Seyedeh Maryam; Periasamy, Vengadesh; Ritikos, Richard; Abd Majid, Wan Haliza; Abdul Rahman, Saadah

2012-01-01

This work presents an experimental study of gold-DNA-gold structures in the presence and absence of external magnetic fields with strengths less than 1,200.00 mT. The DNA strands, extracted by standard method were used to fabricate a Metal-DNA-Metal (MDM) structure. Its electric behavior when subjected to a magnetic field was studied through its current-voltage (I-V) curve. Acquisition of the I-V curve demonstrated that DNA as a semiconductor exhibits diode behavior in the MDM structure. The current versus magnetic field strength followed a decreasing trend because of a diminished mobility in the presence of a low magnetic field. This made clear that an externally imposed magnetic field would boost resistance of the MDM structure up to 1,000.00 mT and for higher magnetic field strengths we can observe an increase in potential barrier in MDM junction. The magnetic sensitivity indicates the promise of using MDM structures as potential magnetic sensors.

Broadbanding of circularly polarized patch antenna by waveguided magneto-dielectric metamaterial

NASA Astrophysics Data System (ADS)

Yang, Xin Mi; Wen, Juan; Liu, Chang Rong; Liu, Xue Guan; Cui, Tie Jun

2015-12-01

Design of bandwidth-enhanced circularly polarized (CP) patch antenna using artificial magneto-dielectric substrate was investigated. The artificial magneto-dielectric material adopted here takes the form of waveguided metamaterial (WG-MTM). In particular, the embedded meander line (EML) structure was employed as the building element of the WG-MTM. As verified by the retrieved effective medium parameters, the EML-based waveguided magneto-dielectric metamaterial (WG-MDM) exhibits two-dimensionally isotropic magneto-dielectric property with respect to TEM wave excitations applied in two orthogonal directions. A CP patch antenna loaded with the EML-based WG-MDM (WG-MDM antenna) has been proposed and its design procedure is described in detail. Simulation results show that the impedance and axial ratio bandwidths of the WG-MDM antenna have increased by 125% and 133%, respectively, compared with those obtained with pure dielectric substrate offering the same patch size. The design of the novel WG-MDM antenna was also validated by measurement results, which show good agreement with their simulated counterparts.

Electrical Characterization of Gold-DNA-Gold Structures in Presence of an External Magnetic Field by Means of I–V Curve Analysis

PubMed Central

Khatir, Nadia Mahmoudi; Banihashemian, Seyedeh Maryam; Periasamy, Vengadesh; Ritikos, Richard; Majid, Wan Haliza Abd; Rahman, Saadah Abdul

2012-01-01

This work presents an experimental study of gold-DNA-gold structures in the presence and absence of external magnetic fields with strengths less than 1,200.00 mT. The DNA strands, extracted by standard method were used to fabricate a Metal-DNA-Metal (MDM) structure. Its electric behavior when subjected to a magnetic field was studied through its current-voltage (I–V) curve. Acquisition of the I–V curve demonstrated that DNA as a semiconductor exhibits diode behavior in the MDM structure. The current versus magnetic field strength followed a decreasing trend because of a diminished mobility in the presence of a low magnetic field. This made clear that an externally imposed magnetic field would boost resistance of the MDM structure up to 1,000.00 mT and for higher magnetic field strengths we can observe an increase in potential barrier in MDM junction. The magnetic sensitivity indicates the promise of using MDM structures as potential magnetic sensors. PMID:22737025

Simulation-Based Validation of the p53 Transcriptional Activity with Hybrid Functional Petri Net.

PubMed

Doi, Atsushi; Nagasaki, Masao; Matsuno, Hiroshi; Miyano, Satoru

2011-01-01

MDM2 and p19ARF are essential proteins in cancer pathways forming a complex with protein p53 to control the transcriptional activity of protein p53. It is confirmed that protein p53 loses its transcriptional activity by forming the functional dimer with protein MDM2. However, it is still unclear that protein p53 keeps its transcriptional activity when it forms the trimer with proteins MDM2 and p19ARF. We have observed mutual behaviors among genes p53, MDM2, p19ARF and their products on a computational model with hybrid functional Petri net (HFPN) which is constructed based on information described in the literature. The simulation results suggested that protein p53 should have the transcriptional activity in the forms of the trimer of proteins p53, MDM2, and p19ARF. This paper also discusses the advantages of HFPN based modeling method in terms of pathway description for simulations.

[The expression of p53, MDM2 and Ref1 gene in cultured retina neurons of SD rats treated with vitamin B1 and/or elevated pressure].

PubMed

Yang, Zhikuan; Ge, Jian; Yin, Wei; Shen, Huangxuan; Liu, Haiquan; Guo, Yan

2004-12-01

To investigate the expression of p53, MDM2 and Ref1 gene in cultured retina neurons of SD rats treated with Vitamin B1 and (or) elevated pressure. The retinal neuron of postnatal SD rats were cultured in vivo, the elevated pressure was produced after 7 days, and the total RNA was extracted after another 2 days, expression of p53, MDM2 and Ref1 gene were analyzed with RT-PCR. The expression level of p53 and MDM2 gene were increased in elevated pressure group, normal with Ref1 gene expression. But the expression of p53 and MDM2 gene were decreased significantly in elevated pressure group treated with vitamine B1 compare to the elevated group. Apoptosis seem to be a mechanism of cell death in retinal neurons of SD rats with elevated pressure.Vitamine B1 have protect effects against elevated pressure.

Phosphatidylserine transport by Ups2-Mdm35 in respiration-active mitochondria.

PubMed

Miyata, Non; Watanabe, Yasunori; Tamura, Yasushi; Endo, Toshiya; Kuge, Osamu

2016-07-04

Phosphatidylethanolamine (PE) is an essential phospholipid for mitochondrial functions and is synthesized mainly by phosphatidylserine (PS) decarboxylase at the mitochondrial inner membrane. In Saccharomyces cerevisiae, PS is synthesized in the endoplasmic reticulum (ER), such that mitochondrial PE synthesis requires PS transport from the ER to the mitochondrial inner membrane. Here, we provide evidence that Ups2-Mdm35, a protein complex localized at the mitochondrial intermembrane space, mediates PS transport for PE synthesis in respiration-active mitochondria. UPS2- and MDM35-null mutations greatly attenuated conversion of PS to PE in yeast cells growing logarithmically under nonfermentable conditions, but not fermentable conditions. A recombinant Ups2-Mdm35 fusion protein exhibited phospholipid-transfer activity between liposomes in vitro. Furthermore, UPS2 expression was elevated under nonfermentable conditions and at the diauxic shift, the metabolic transition from glycolysis to oxidative phosphorylation. These results demonstrate that Ups2-Mdm35 functions as a PS transfer protein and enhances mitochondrial PE synthesis in response to the cellular metabolic state. © 2016 Miyata et al.

Simultaneous Targeting of RGD-Integrins and Dual Murine Double Minute Proteins in Glioblastoma Multiforme.

PubMed

Merlino, Francesco; Daniele, Simona; La Pietra, Valeria; Di Maro, Salvatore; Di Leva, Francesco Saverio; Brancaccio, Diego; Tomassi, Stefano; Giuntini, Stefano; Cerofolini, Linda; Fragai, Marco; Luchinat, Claudio; Reichart, Florian; Cavallini, Chiara; Costa, Barbara; Piccarducci, Rebecca; Taliani, Sabrina; Da Settimo, Federico; Martini, Claudia; Kessler, Horst; Novellino, Ettore; Marinelli, Luciana

2018-05-18

In the fight against Glioblastoma Multiforme, recent literature data have highlighted that integrin α5β1 and p53 are part of convergent pathways in the control of glioma apoptosis. This observation prompted us to seek a molecule able to simultaneously modulate both target families. Analyzing the results of a previous virtual screening against murine double minute 2 protein (MDM2), we envisaged that Arg-Gly-Asp (RGD)-mimetic molecules could be inhibitors of MDM2/4. Herein we present the discovery of compound 7, which inhibits both MDM2/4 and α5β1/αvβ3 integrins. A lead optimization campaign was carried out on 7 with aim to preserve the activities on integrins while improving those on MDM proteins. Compound 9 turned out to be a potent MDM2/4, and α5β1/αvβ3 blocker. In p53-wild type glioma cells, 9 arrested cell cycle and proliferation and strongly reduced cell invasiveness, emerging as the first molecule of a novel class of integrin/MDM inhibitors, which might be especially useful in subpopulations of patients with glioblastoma expressing a functional p53 concomitantly with a high level of α5β1 integrin.

TRIM25 has a dual function in the p53/Mdm2 circuit.

PubMed

Zhang, P; Elabd, S; Hammer, S; Solozobova, V; Yan, H; Bartel, F; Inoue, S; Henrich, T; Wittbrodt, J; Loosli, F; Davidson, G; Blattner, C

2015-11-12

P53 is an important tumor suppressor that, upon activation, induces growth arrest and cell death. Control of p53 is thus of prime importance for proliferating cells, but also for cancer therapy, where p53 activity contributes to the eradication of tumors. Mdm2 functionally inhibits p53 and targets the tumor suppressor protein for degradation. In a genetic screen, we identified TRIM25 as a novel regulator of p53 and Mdm2. TRIM25 increased p53 and Mdm2 abundance by inhibiting their ubiquitination and degradation in 26 S proteasomes. TRIM25 co-precipitated with p53 and Mdm2 and interfered with the association of p300 and Mdm2, a critical step for p53 polyubiquitination. Despite the increase in p53 levels, p53 activity was inhibited in the presence of TRIM25. Downregulation of TRIM25 resulted in an increased acetylation of p53 and p53-dependent cell death in HCT116 cells. Upon genotoxic insults, TRIM25 dampened the p53-dependent DNA damage response. The downregulation of TRIM25 furthermore resulted in massive apoptosis during early embryogenesis of medaka, which was rescued by the concomitant downregulation of p53, demonstrating the functional relevance of the regulation of p53 by TRIM25 in an organismal context.

p53 AND MDM2 PROTEIN EXPRESSION IN ACTINIC CHEILITIS

PubMed Central

de Freitas, Maria da Conceição Andrade; Ramalho, Luciana Maria Pedreira; Xavier, Flávia Caló Aquino; Moreira, André Luis Gomes; Reis, Sílvia Regina Almeida

2008-01-01

Actinic cheilitis is a potentially malignant lip lesion caused by excessive and prolonged exposure to ultraviolet radiation, which can lead to histomorphological alterations indicative of abnormal cell differentiation. In this pathology, varying degrees of epithelial dysplasia may be found. There are few published studies regarding the p53 and MDM2 proteins in actinic cheilitis. Fifty-eight cases diagnosed with actinic cheilitis were histologically evaluated using Banóczy and Csiba (1976) parameters, and were subjected to immunohistochemical analysis using the streptavidin-biotin method in order to assess p53 and MDM2 protein expression. All studied cases expressed p53 proteins in basal and suprabasal layers. In the basal layer, the nuclei testing positive for p53 were stained intensely, while in the suprabasal layer, cells with slightly stained nuclei were predominant. All cases also tested positive for the MDM2 protein, but with varying degrees of nuclear expression and a predominance of slightly stained cells. A statistically significant correlation between the percentage of p53 and MDM2-positive cells was established, regardless of the degree of epithelial dysplasia. The expression of p53 and MDM2 proteins in actinic cheilitis can be an important indicator in lip carcinogenesis, regardless of the degree of epithelial dysplasia. PMID:19082401

p53 and MDM2 protein expression in actinic cheilitis.

PubMed

de Freitas, Maria da Conceição Andrade; Ramalho, Luciana Maria Pedreira; Xavier, Flávia Caló Aquino; Moreira, André Luis Gomes; Reis, Sílvia Regina Almeida

2008-01-01

Actinic cheilitis is a potentially malignant lip lesion caused by excessive and prolonged exposure to ultraviolet radiation, which can lead to histomorphological alterations indicative of abnormal cell differentiation. In this pathology, varying degrees of epithelial dysplasia may be found. There are few published studies regarding the p53 and MDM2 proteins in actinic cheilitis. Fifty-eight cases diagnosed with actinic cheilitis were histologically evaluated using Banóczy and Csiba (1976) parameters, and were subjected to immunohistochemical analysis using the streptavidin-biotin method in order to assess p53 and MDM2 protein expression. All studied cases expressed p53 proteins in basal and suprabasal layers. In the basal layer, the nuclei testing positive for p53 were stained intensely, while in the suprabasal layer, cells with slightly stained nuclei were predominant. All cases also tested positive for the MDM2 protein, but with varying degrees of nuclear expression and a predominance of slightly stained cells. A statistically significant correlation between the percentage of p53 and MDM2-positive cells was established, regardless of the degree of epithelial dysplasia. The expression of p53 and MDM2 proteins in actinic cheilitis can be an important indicator in lip carcinogenesis, regardless of the degree of epithelial dysplasia.

Non-thermal production of minimal dark matter via right-handed neutrino decay

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aoki, Mayumi; Toma, Takashi; Vicente, Avelino

2015-09-29

Minimal Dark Matter (MDM) stands as one of the simplest dark matter scenarios. In MDM models, annihilation and co-annihilation processes among the members of the MDM multiplet are usually very efficient, pushing the dark matter mass above O(10) TeV in order to reproduce the observed dark matter relic density. Motivated by this little drawback, in this paper we consider an extension of the MDM scenario by three right-handed neutrinos. Two specific choices for the MDM multiplet are studied: a fermionic SU(2){sub L} quintuplet and a scalar SU(2){sub L} septuplet. The lightest right-handed neutrino, with tiny Yukawa couplings, never reaches thermalmore » equilibrium in the early universe and is produced by freeze-in. This creates a link between dark matter and neutrino physics: dark matter can be non-thermally produced by the decay of the lightest right-handed neutrino after freeze-out, allowing to lower significantly the dark matter mass. We discuss the phenomenology of the non-thermally produced MDM and, taking into account significant Sommerfeld corrections, we find that the dark matter mass must have some specific values in order not to be in conflict with the current bounds from gamma-ray observations.« less

Non-thermal production of minimal dark matter via right-handed neutrino decay

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aoki, Mayumi; Toma, Takashi; Vicente, Avelino, E-mail: mayumi@hep.s.kanazawa-u.ac.jp, E-mail: takashi.toma@th.u-psud.fr, E-mail: Avelino.Vicente@ulg.ac.be

2015-09-01

Minimal Dark Matter (MDM) stands as one of the simplest dark matter scenarios. In MDM models, annihilation and co-annihilation processes among the members of the MDM multiplet are usually very efficient, pushing the dark matter mass above O(10) TeV in order to reproduce the observed dark matter relic density. Motivated by this little drawback, in this paper we consider an extension of the MDM scenario by three right-handed neutrinos. Two specific choices for the MDM multiplet are studied: a fermionic SU(2){sub L} quintuplet and a scalar SU(2){sub L} septuplet. The lightest right-handed neutrino, with tiny Yukawa couplings, never reaches thermalmore » equilibrium in the early universe and is produced by freeze-in. This creates a link between dark matter and neutrino physics: dark matter can be non-thermally produced by the decay of the lightest right-handed neutrino after freeze-out, allowing to lower significantly the dark matter mass. We discuss the phenomenology of the non-thermally produced MDM and, taking into account significant Sommerfeld corrections, we find that the dark matter mass must have some specific values in order not to be in conflict with the current bounds from gamma-ray observations.« less

Quantification of MDL-induced signal degradation in MIMO-OFDM mode-division multiplexing systems.

PubMed

Tian, Yu; Li, Juhao; Zhu, Paikun; Wu, Zhongying; Chen, Yuanxiang; He, Yongqi; Chen, Zhangyuan

2016-08-22

Mode-division multiplexing (MDM) transmission over few-mode optical fiber has emerged as a promising technology to enhance transmission capacity, in which multiple-input-multiple-output (MIMO) digital signal processing (DSP) after coherent detection is used to demultiplex the signals. Compared with conventional single-mode systems, MIMO-MDM systems suffer non-recoverable signal degradation induced by mode-dependent loss (MDL). In this paper, the MDL-induced signal degradation in orthogonal-frequency-division-multiplexing (OFDM) MDM systems is theoretically quantified in terms of mode-average error vector magnitude (EVM) through frequency domain norm analysis. A novel scalar MDL metric is proposed considering the probability distribution of the practical MDM input signals, and a closed-form expression for EVM measured after zero-force (ZF) MIMO equalization is derived. Simulation results show that the EVM estimations utilizing the novel MDL metric remain unbiased for unrepeated links. For a 6 × 100 km 20-mode MDM transmission system, the estimation accuracy is improved by more than 90% compared with that utilizing traditional condition number (CN) based MDL metric. The proposed MDL metric can be used to predict the MDL-induced SNR penalty in a theoretical manner, which will be beneficial for the design of practical MIMO-MDM systems.

Lack of Association of the TP53 Arg72Pro SNP and the MDM2 SNP309 with systemic lupus erythematosus in Caucasian, African American, and Asian children and adults

PubMed Central

Onel, KB; Huo, D; Hastings, D; Fryer-Biggs, J; Crow, MK; Onel, K

2009-01-01

The p53 tumour suppressor is the central regulator of apoptosis. Previously, the functional TP53 Arg72Pro polymorphism was found to be associated with systemic lupus erythematosus (SLE) in Koreans but not Spaniards. MDM2 is the major negative regulator of p53. An intronic polymorphism in MDM2, the SNP309, attenuates p53 activity and is associated with accelerated tumour development in premenopausal women. Polymorphic variation in MDM2 has never been studied in SLE. The aim of this study is to further assess the contribution of p53-pathway genetic variation to SLE by testing the association of the TP53 Arg72Pro polymorphism and the MDM2 SNP309 with SLE in a well-characterised and ethnically diverse cohort of patients with both childhood- and adult-onset SLE (n = 314). No association was found between the TP53 Arg72Pro polymorphism and SLE in patients of European descent, Asian descent or in African Americans, nor was an association found between the MDM2 SNP309 and SLE in patients of European descent or in African Americans. In addition, there was no correlation between either variant and early-onset disease or nephritis, an index of severe disease. It is concluded that neither the TP53 Arg72Pro polymorphism nor the MDM2 SNP309 contributes significantly to either susceptibility or disease severity in SLE. PMID:19074170

Proteomic investigating the cooperative lethal effect of EGFR and MDM2 inhibitors on ovarian carcinoma.

PubMed

Chang, Shing-Jyh; Liao, En-Chi; Yeo, Hsin-Yueh; Kuo, Wen-Hung; Chen, Hsin-Yi; Tsai, Yi-Ting; Wei, Yu-Shan; Chen, Ying-Jen; Wang, Yi-Shiuan; Li, Ji-Min; Shih, Chuan-Chi; Chan, Chia-Hao; Lai, Zih-Yin; Chou, Hsiu-Chuan; Chuang, Yung-Jen; Chan, Hong-Lin

2018-06-01

With the concept of precision medicine, combining multiple molecular-targeting therapies has brought new approaches to current cancer treatments. Malfunction of the tumor suppressor protein, p53 is a universal hallmark in human cancers. Under normal conditions, p53 is degraded through an ubiquitin-proteosome pathway regulated by its negative regulator, MDM2. In contrast, cellular stress such as DNA damage will activate p53 to carry out DNA repair, cell cycle arrest, and apoptosis. In this study, we focused on ovarian carcinoma with high EGFR and MDM2 overexpression rate. We assessed the effects of combined inhibition by MDM2 (JNJ-26854165) and EGFR (gefitinib) inhibitors on various ovarian cell lines to determine the importance of these two molecular targets on cell proliferation. We then used a proteomic strategy to investigate the relationship between MDM2 and EGFR inhibition to explore the underlying mechanisms of how their combined signaling blockades work together to exert cooperative inhibition. Our results demonstrated that all four cell lines were sensitive to both individual and combined, MDM2 and EGFR inhibition. The proteomic analysis also showed that gefitinib/JNJ-treated CAOV3 cells exhibited downregulation of proteins involved in nucleotide biosynthesis such as nucleoside diphosphate kinase B (NME2). In conclusion, our study showed that the combined treatment with JNJ and gefitinib exerted synergistic inhibition on cell proliferation, thereby suggesting the potential application of combining MDM2 inhibitors with EGFR inhibitors for enhancing efficacy in ovarian cancer treatment. Copyright © 2018 Elsevier Inc. All rights reserved.

The willingness and actual situation of Chinese cancer patients and their family members participating in medical decision-making.

PubMed

Zhang, Jie; Yang, Dan; Deng, Yaotiao; Wang, Ying; Deng, Lei; Luo, Xinmei; Zhong, Wuning; Liu, Jie; Wang, Yuqing; Jiang, Yu

2015-12-01

In China, not only patients and physicians are involved in medical decision-making (MDM) but also the patients' family members. The objective is to investigate the willingness and actual situation of cancer patients and their family members participating in the MDM process. In this cross-sectional study, questionnaires were administered to 247 pairs of cancer inpatients and their relatives. Information regarding participants' willingness and actual experience during the decision-making process was documented. Eligible participants were cancer inpatients or their relatives, 18 years of age or older, and informed of the cancer diagnosis. All the patients should have received chemotherapy. The effective response rate was 72.9% (180/247). Over half of the patients (53.3%) and family members (57.8%) were willing to be part of the MDM process. In contrast, only 35.0% of patients and 46.1% of family members actually experienced this process (p = 0.001 and p = 0.011, respectively). Fewer family members (42.2%) than patients (53.3%) believed that patients should be involved in the MDM process (p < 0.001). Patients who were the head of their family (odds ratio 2.577, 95% CI 1.198-5.556, p = 0.015) experienced more involvement in MDM. Although more than half of Chinese cancer patients and family members wanted to be part of MDM, the actual participation was below their expectation. Majority of family members do not want the patients to be involved in the process of MDM. Copyright © 2015 John Wiley & Sons, Ltd.

Np9, a cellular protein of retroviral ancestry restricted to human, chimpanzee and gorilla, binds and regulates ubiquitin ligase MDM2

PubMed Central

Heyne, Kristina; Kölsch, Kathrin; Bruand, Marine; Kremmer, Elisabeth; Grässer, Friedrich A; Mayer, Jens; Roemer, Klaus

2015-01-01

Humans and primates are long-lived animals with long reproductive phases. One factor that appears to contribute to longevity and fertility in humans, as well as to cancer-free survival, is the transcription factor and tumor suppressor p53, controlled by its main negative regulator MDM2. However, p53 and MDM2 homologs are found throughout the metazoan kingdom from Trichoplacidae to Hominidae. Therefore the question arises, if p53/MDM2 contributes to the shaping of primate features, then through which mechanisms. Previous findings have indicated that the appearances of novel p53-regulated genes and wild-type p53 variants during primate evolution are important in this context. Here, we report on another mechanism of potential relevance. Human endogenous retrovirus K subgroup HML-2 (HERV-K(HML-2)) type 1 proviral sequences were formed in the genomes of the predecessors of contemporary Hominoidea and can be identified in the genomes of Nomascus leucogenys (gibbon) up to Homo sapiens. We previously reported on an alternative splicing event in HERV-K(HML-2) type 1 proviruses that can give rise to nuclear protein of 9 kDa (Np9). We document here the evolution of Np9-coding capacity in human, chimpanzee and gorilla, and show that the C-terminal half of Np9 binds directly to MDM2, through a domain of MDM2 that is known to be contacted by various cellular proteins in response to stress. Np9 can inhibit the MDM2 ubiquitin ligase activity toward p53 in the cell nucleus, and can support the transactivation of genes by p53. Our findings point to the possibility that endogenous retrovirus protein Np9 contributes to the regulation of the p53-MDM2 pathway specifically in humans, chimpanzees and gorillas. PMID:26103464

Functional activation of mutant p53V172F by platinum analogs in cisplatin-resistant human tumor cells is dependent on serine-20 phosphorylation

PubMed Central

Xie, Xiaolei; He, Guangan; Siddik, Zahid H.

2017-01-01

Dysfunctionality of the p53 tumor suppressor is a major cause of therapeutic drug resistance in cancer. Recently we reported that mutant, but otherwise functional, p53V172F was inactivated in cisplatin-resistant 2780CP/Cl-16 and 2780CP/Cl-24 human ovarian tumor cells by increased recruitment of the inhibitor MDM4. The current study demonstrates that, unlike cisplatin, platinum analogs oxaliplatin and DACH-diacetato-dichloro-Pt(IV) (DAP), strongly stabilize and activate p53V172F in resistant cells, as indicated by prolonged p53 half-life and transactivation of targets p21 (CDKN1A) and MDM2. This increase in MDM2 reduced MDM4 levels in cell lysates as well as the p53 immunocomplex and prevented reversion of p53 to the inactive p53-MDM2-MDM4 bound state. Phosphorylation of p53 at Ser15 was demonstrated by all three drugs in sensitive A2780 and corresponding resistant 2780CP/Cl-16 and 2780CP/Cl-24 cell lines. However, cisplatin induced Ser20 phosphorylation in A2780 cells only, but not in resistant cells; in contrast, both DAP and oxaliplatin induced this phosphorylation in all three cell lines. The inference that Ser20 phosphorylation is more important for p53 activation was confirmed by ectopic expression of a phosphomimetic (S20D) mutant p53 that displayed reduced binding, relative to wild-type p53, to both MDM2 and MDM4 in p53-knockout A2780 cells. In consonance, temporal studies demonstrated drug-induced Ser15 phosphorylation coincided with p53 stabilization, whereas Ser20 phosphorylation coincided with p53 transactivation. Implications Cisplatin fails to activate the pathway involved in phosphorylating mutant p53V172F at Ser20 in resistant cells, but this phosphorylation is restored by oxaliplatin and DAP that reactivates p53 function and circumvents cisplatin resistance. PMID:28031409

Mitigation of nonlinear fiber distortion using optical phase conjugation for mode-division multiplexed transmission

NASA Astrophysics Data System (ADS)

Zhang, Kai; Gao, Guanjun; Zhang, Jie; Fei, Aimei; Cvijetic, Milorad

2018-07-01

We have investigated and proposed the use of optical phase conjugation (OPC) technique to mitigate the impact of fiber nonlinearities in mode-division multiplexed transmission systems. Numerical simulations are performed for three wavelengths, each loaded with 200 Gb/s dual-polarization 16-level quadrature amplitude modulation (DP-16QAM) format, in weakly guided two-mode fiber. It is known that differential mode group delay (DMGD) in mode-division multiplexed (MDM) transmission systems could be beneficial for system performance of MDM system with MIMO compensation in place. On the other side, for MDM system with OPC in place, the presence of DMGD may limit the overall benefits since signal power evolution per spatial modes should be symmetrical at the system midpoint in order to realize an effective compensation of the nonlinear effects. Our simulation results show that in the reference case (in the absence of DMGD), the employment of OPC module would lead to an average Q-factor improvement of approximately 10 dB. At the same time, in the presence of DMGD, an average Q-factor improvement would be ∼2.8 dB for WDM case. In addition, due to asymmetrical signal power map, the penalties induced by a periodic amplification process cannot be ideally compensated by the midpoint insertion of OPC. However, by accounting the impacts of both DMGD and asymmetrical signal power map, the insertion of the OPC system will still lead to an average Q-factor improvement of ∼1 dB for WDM channel arrangement.

The role of p53 in cancer drug resistance and targeted chemotherapy.

PubMed

Hientz, Karin; Mohr, André; Bhakta-Guha, Dipita; Efferth, Thomas

2017-01-31

Cancer has long been a grievous disease complicated by innumerable players aggravating its cure. Many clinical studies demonstrated the prognostic relevance of the tumor suppressor protein p53 for many human tumor types. Overexpression of mutated p53 with reduced or abolished function is often connected to resistance to standard medications, including cisplatin, alkylating agents (temozolomide), anthracyclines, (doxorubicin), antimetabolites (gemcitabine), antiestrogenes (tamoxifen) and EGFR-inhibitors (cetuximab). Such mutations in the TP53 gene are often accompanied by changes in the conformation of the p53 protein. Small molecules that restore the wild-type conformation of p53 and, consequently, rebuild its proper function have been identified. These promising agents include PRIMA-1, MIRA-1, and several derivatives of the thiosemicarbazone family. In addition to mutations in p53 itself, p53 activity may be also be impaired due to alterations in p53's regulating proteins such as MDM2. MDM2 functions as primary cellular p53 inhibitor and deregulation of the MDM2/p53-balance has serious consequences. MDM2 alterations often result in its overexpression and therefore promote inhibition of p53 activity. To deal with this problem, a judicious approach is to employ MDM2 inhibitors. Several promising MDM2 inhibitors have been described such as nutlins, benzodiazepinediones or spiro-oxindoles as well as novel compound classes such as xanthone derivatives and trisubstituted aminothiophenes. Furthermore, even naturally derived inhibitor compounds such as α-mangostin, gambogic acid and siladenoserinols have been discovered. In this review, we discuss in detail such small molecules that play a pertinent role in affecting the p53-MDM2 signaling axis and analyze their potential as cancer chemotherapeutics.

Mimicking a p53-MDM2 interaction based on a stable immunoglobulin-like domain scaffold.

PubMed

Jimenez-Sandoval, Pedro; Madrigal-Carrillo, Ezequiel A; Santamaría-Suárez, Hugo A; Maturana, Daniel; Rentería-González, Itzel; Benitez-Cardoza, Claudia G; Torres-Larios, Alfredo; Brieba, Luis G

2018-04-26

Antibodies recognize protein targets with great affinity and specificity. However, posttranslational modifications and the presence of intrinsic disulfide-bonds pose difficulties for their industrial use. The immunoglobulin fold is one of the most ubiquitous folds in nature and it is found in many proteins besides antibodies. An example of a protein family with an immunoglobulin-like fold is the Cysteine Protease Inhibitors (ICP) family I42 of the MEROPs database for protease and protease inhibitors. Members of this protein family are thermostable and do not present internal disulfide bonds. Crystal structures of several ICPs indicate that they resemble the Ig-like domain of the human T cell co-receptor CD8α As ICPs present 2 flexible recognition loops that vary accordingly to their targeted protease, we hypothesize that members of this protein family would be ideal to design peptide aptamers that mimic protein-protein interactions. Herein, we use an ICP variant from Entamoeba histolytica (EhICP1) to mimic the interaction between p53 and MDM2. We found that a 13 amino-acid peptide derived from p53 can be introduced in 2 variable loops (DE, FG) but not the third (BC). Chimeric EhICP1-p53 form a stable complex with MDM2 at a micromolar range. Crystal structure of the EhICP1-p53(FG)-loop variant in complex with MDM2 reveals a swapping subdomain between 2 chimeric molecules, however, the p53 peptide interacts with MDM2 as in previous crystal structures. The structural details of the EhICP1-p53(FG) interaction with MDM2 resemble the interaction between an antibody and MDM2. © 2018 Wiley Periodicals, Inc.

Nutlin-3 down-regulates retinoblastoma protein expression and inhibits muscle cell differentiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walsh, Erica M.; Niu, MengMeng; Bergholz, Johann

The p53 tumor suppressor gene plays a critical role in regulation of proliferation, cell death and differentiation. The MDM2 oncoprotein is a major negative regulator for p53 by binding to and targeting p53 for proteasome-mediated degradation. The small molecule inhibitor, nutlin-3, disrupts MDM2-p53 interaction resulting in stabilization and activation of p53 protein. We have previously shown that nutlin-3 activates p53, leading to MDM2 accumulation as concomitant of reduced retinoblastoma (Rb) protein stability. It is well known that Rb is important in muscle development and myoblast differentiation and that rhabdomyosarcoma (RMS), or cancer of the skeletal muscle, typically harbors MDM2 amplification.more » In this study, we show that nutlin-3 inhibited myoblast proliferation and effectively prevented myoblast differentiation, as evidenced by lack of expression of muscle differentiation markers including myogenin and myosin heavy chain (MyHC), as well as a failure to form multinucleated myotubes, which were associated with dramatic increases in MDM2 expression and decrease in Rb protein levels. These results indicate that nutlin-3 can effectively inhibit muscle cell differentiation. - Highlights: • Nutlin-3 inhibits myoblast proliferation and prevents differentiation into myotubes. • Nutlin-3 increases MDM2 expression and down-regulates Rb protein levels. • This study has implication in nutlin-3 treatment of rhabdomyosarcomas.« less

MicroRNA-188-3p is involved in sevoflurane anesthesia-induced neuroapoptosis by targeting MDM2

PubMed Central

Wang, Lei; Zheng, Mengliang; Wu, Shuishui; Niu, Zhiqiang

2018-01-01

Sevoflurane is a commonly used inhalation anesthetic. Sevoflurane-induced neuroapoptosis and cognitive impairments in animals are widely reported, however, the underlying molecular mechanisms remain largely unknown. The results of the present study demonstrated that sevoflurane anesthesia induced spatial memory impairments in rats, as determined by the Morris water maze test. Mechanistically, the current study demonstrated that sevoflurane administration significantly enhanced the expression of microRNA (miR)-188-3p. Furthermore, inhibition of miR-188-3p using lentiviral miR-188-3p inhibitors attenuated sevoflurane-induced cognitive impairments in rats. The present study also demonstrated that miR-188-3p targeted MDM2 proto-oncogene (MDM2) and negatively regulated the expression of MDM2, as determined by luciferase assays, reverse transcription-quantitative polymerase chain reaction and western blot analysis. Furthermore, decreased abundance of MDM2 following transfection with miR-188-3p mimics was associated with increased stability of p53 protein. Suppression of p53 activity using the specific p53 inhibitor pifithrin-α alleviated sevoflurane-induced neuroapoptosis. These results indicate that the miR-188-3p-MDM2-p53 axis may have a critical role in sevoflurane-induced cognitive dysfunction. Therefore, miR-188-3p may be a potential target for the treatment of sevoflurane-induced cognitive impairment. PMID:29344658

Regulation of androgen receptor and histone deacetylase 1 by Mdm2-mediated ubiquitylation.

PubMed

Gaughan, Luke; Logan, Ian R; Neal, David E; Robson, Craig N

2005-01-01

The androgen receptor (AR) is a member of the nuclear hormone receptor family of transcription factors and plays a critical role in regulating the expression of genes involved in androgen-dependent and -independent tumour formation. Regulation of the AR is achieved by alternate binding of either histone acetyltransferase (HAT)-containing co-activator proteins, or histone deacetylase 1 (HDAC1). Factors that control AR stability may also constitute an important regulatory mechanism, a notion that has been confirmed with the finding that the AR is a direct target for Mdm2-mediated ubiquitylation and proteolysis. Using chromatin immunoprecipitation (ChIP) and re-ChIP analyses, we show that Mdm2 associates with AR and HDAC1 at the active androgen-responsive PSA promoter in LNCaP prostate cancer cells. Furthermore, we demonstrate that Mdm2-mediated modification of AR and HDAC1 catalyses protein destabilization and attenuates AR sactivity, suggesting that ubiquitylation of the AR and HDAC1 may constitute an additional mechanism for regulating AR function. We also show that HDAC1 and Mdm2 function co-operatively to reduce AR-mediated transcription that is attenuated by the HAT activity of the AR co-activator Tip60, suggesting interplay between acetylation status and receptor ubiquitylation in AR regulation. In all, our data indicates a novel role for Mdm2 in regulating components of the AR transcriptosome.

Application of binding free energy calculations to prediction of binding modes and affinities of MDM2 and MDMX inhibitors.

PubMed

Lee, Hui Sun; Jo, Sunhwan; Lim, Hyun-Suk; Im, Wonpil

2012-07-23

Molecular docking is widely used to obtain binding modes and binding affinities of a molecule to a given target protein. Despite considerable efforts, however, prediction of both properties by docking remains challenging mainly due to protein's structural flexibility and inaccuracy of scoring functions. Here, an integrated approach has been developed to improve the accuracy of binding mode and affinity prediction and tested for small molecule MDM2 and MDMX antagonists. In this approach, initial candidate models selected from docking are subjected to equilibration MD simulations to further filter the models. Free energy perturbation molecular dynamics (FEP/MD) simulations are then applied to the filtered ligand models to enhance the ability in predicting the near-native ligand conformation. The calculated binding free energies for MDM2 complexes are overestimated compared to experimental measurements mainly due to the difficulties in sampling highly flexible apo-MDM2. Nonetheless, the FEP/MD binding free energy calculations are more promising for discriminating binders from nonbinders than docking scores. In particular, the comparison between the MDM2 and MDMX results suggests that apo-MDMX has lower flexibility than apo-MDM2. In addition, the FEP/MD calculations provide detailed information on the different energetic contributions to ligand binding, leading to a better understanding of the sensitivity and specificity of protein-ligand interactions.

Induction of apoptosis in Ehrlich ascites tumour cells via p53 activation by a novel small-molecule MDM2 inhibitor - LQFM030.

PubMed

da Mota, Mariana F; Cortez, Alane P; Benfica, Polyana L; Rodrigues, Bruna Dos S; Castro, Thalyta F; Macedo, Larissa M; Castro, Carlos H; Lião, Luciano M; de Carvalho, Flávio S; Romeiro, Luiz A S; Menegatti, Ricardo; Verli, Hugo; Villavicencio, Bianca; Valadares, Marize C

2016-09-01

The activation of the p53 pathway through the inhibition of MDM2 has been proposed as a novel therapeutic strategy against tumours. A series of cis-imidazoline analogues, termed nutlins, were reported to displace the recombinant p53 protein from its complex with MDM2 by binding to MDM2 in the p53 pocket, and exhibited an antitumour activity both in vitro and in vivo. Thus, the purpose of this study was to evaluate the antitumour properties of LQFM030 (2), a nutlin analogue created by employing the strategy of molecular simplification. LQFM030 (2) cytotoxicity was evaluated in Ehrlich ascites tumour (EAT) cells, p53 wild type, by the trypan blue exclusion test, and the mechanisms involved in EAT cell death were investigated by light and fluorescence microscopy, flow cytometry, real-time PCR and Western blotting. Our results demonstrate that LQFM030 has dose-dependent antiproliferative activity and cytotoxic activity on EAT cells, induces the accumulation of p53 protein and promotes cell cycle arrest and apoptosis. p53 gene transcription was unaffected by LQFM030 (2); however, MDM2 mRNA increased and MDM2 protein decreased. These results suggest that the small-molecule p53 activator LQFM030 (2) has the potential for further development as a novel cancer therapeutic agent. © 2016 Royal Pharmaceutical Society.

Whole-transcriptome, high-throughput RNA sequence analysis of the bovine macrophage response to Mycobacterium bovis infection in vitro.

PubMed

Nalpas, Nicolas C; Park, Stephen D E; Magee, David A; Taraktsoglou, Maria; Browne, John A; Conlon, Kevin M; Rue-Albrecht, Kévin; Killick, Kate E; Hokamp, Karsten; Lohan, Amanda J; Loftus, Brendan J; Gormley, Eamonn; Gordon, Stephen V; MacHugh, David E

2013-04-08

Mycobacterium bovis, the causative agent of bovine tuberculosis, is an intracellular pathogen that can persist inside host macrophages during infection via a diverse range of mechanisms that subvert the host immune response. In the current study, we have analysed and compared the transcriptomes of M. bovis-infected monocyte-derived macrophages (MDM) purified from six Holstein-Friesian females with the transcriptomes of non-infected control MDM from the same animals over a 24 h period using strand-specific RNA sequencing (RNA-seq). In addition, we compare gene expression profiles generated using RNA-seq with those previously generated by us using the high-density Affymetrix® GeneChip® Bovine Genome Array platform from the same MDM-extracted RNA. A mean of 7.2 million reads from each MDM sample mapped uniquely and unambiguously to single Bos taurus reference genome locations. Analysis of these mapped reads showed 2,584 genes (1,392 upregulated; 1,192 downregulated) and 757 putative natural antisense transcripts (558 upregulated; 119 downregulated) that were differentially expressed based on sense and antisense strand data, respectively (adjusted P-value ≤ 0.05). Of the differentially expressed genes, 694 were common to both the sense and antisense data sets, with the direction of expression (i.e. up- or downregulation) positively correlated for 693 genes and negatively correlated for the remaining gene. Gene ontology analysis of the differentially expressed genes revealed an enrichment of immune, apoptotic and cell signalling genes. Notably, the number of differentially expressed genes identified from RNA-seq sense strand analysis was greater than the number of differentially expressed genes detected from microarray analysis (2,584 genes versus 2,015 genes). Furthermore, our data reveal a greater dynamic range in the detection and quantification of gene transcripts for RNA-seq compared to microarray technology. This study highlights the value of RNA-seq in identifying novel immunomodulatory mechanisms that underlie host-mycobacterial pathogen interactions during infection, including possible complex post-transcriptional regulation of host gene expression involving antisense RNA.

C–C Chemokines Released by Lipopolysaccharide (LPS)-stimulated Human Macrophages Suppress HIV-1 Infection in Both Macrophages and T Cells

PubMed Central

Verani, Alessia; Scarlatti, Gabriella; Comar, Manola; Tresoldi, Eleonora; Polo, Simona; Giacca, Mauro; Lusso, Paolo; Siccardi, Antonio G.; Vercelli, Donata

1997-01-01

Human immunodeficiency virus-1 (HIV-1) expression in monocyte-derived macrophages (MDM) infected in vitro is known to be inhibited by lipopolysaccharide (LPS). However, the mechanisms are incompletely understood. We show here that HIV-1 suppression is mediated by soluble factors released by MDM stimulated with physiologically significant concentrations of LPS. LPS-conditioned supernatants from MDM inhibited HIV-1 replication in both MDM and T cells. Depletion of C–C chemokines (RANTES, MIP-1α, and MIP-1β) neutralized the ability of LPS-conditioned supernatants to inhibit HIV-1 replication in MDM. A combination of recombinant C–C chemokines blocked HIV-1 infection as effectively as LPS. Here, we report an inhibitory effect of C–C chemokines on HIV replication in primary macrophages. Our results raise the possibility that monocytes may play a dual role in HIV infection: while representing a reservoir for the virus, they may contribute to the containment of the infection by releasing factors that suppress HIV replication not only in monocytes but also in T lymphocytes. PMID:9120386

Single-Trial Classification of Multi-User P300-Based Brain-Computer Interface Using Riemannian Geometry.

PubMed

Korczowski, L; Congedo, M; Jutten, C

2015-08-01

The classification of electroencephalographic (EEG) data recorded from multiple users simultaneously is an important challenge in the field of Brain-Computer Interface (BCI). In this paper we compare different approaches for classification of single-trials Event-Related Potential (ERP) on two subjects playing a collaborative BCI game. The minimum distance to mean (MDM) classifier in a Riemannian framework is extended to use the diversity of the inter-subjects spatio-temporal statistics (MDM-hyper) or to merge multiple classifiers (MDM-multi). We show that both these classifiers outperform significantly the mean performance of the two users and analogous classifiers based on the step-wise linear discriminant analysis. More importantly, the MDM-multi outperforms the performance of the best player within the pair.

Effect of the MDM2 antagonist RG7112 on the P53 pathway in patients with MDM2-amplified, well-differentiated or dedifferentiated liposarcoma: an exploratory proof-of-mechanism study.

PubMed

Ray-Coquard, Isabelle; Blay, Jean-Yves; Italiano, Antoine; Le Cesne, Axel; Penel, Nicolas; Zhi, Jianguo; Heil, Florian; Rueger, Ruediger; Graves, Bradford; Ding, Meichun; Geho, David; Middleton, Steven A; Vassilev, Lyubomir T; Nichols, Gwen L; Bui, Binh Nguyen

2012-11-01

We report a proof-of-mechanism study of RG7112, a small-molecule MDM2 antagonist, in patients with chemotherapy-naive primary or relapsed well-differentiated or dedifferentiated MDM2-amplified liposarcoma who were eligible for resection. Patients with well-differentiated or dedifferentiated liposarcoma were enrolled at four centres in France. Patients received up to three 28-day neoadjuvant treatment cycles of RG7112 1440 mg/m(2) per day for 10 days. If a patient progressed at any point after the first cycle, the lesion was resected or, if unresectable, an end-of-study biopsy was done. The primary endpoint was to assess markers of RG7112-dependent MDM2 inhibition and P53 pathway activation (P53, P21, MDM2, Ki-67, macrophage inhibitory cytokine-1 [MIC-1], and apoptosis). All analyses were per protocol. This trial is registered with EudraCT, number 2009-015522-10. Between June 3, and Dec 14, 2010, 20 patients were enrolled and completed pretreatment and day 8 biopsies. 18 of 20 patients had TP53 wild-type tumours and two carried missense TP53 mutations. 14 of 17 assessed patients had MDM2 gene amplification. Compared with baseline, P53 and P21 concentrations, assessed by immunohistochemistry, had increased by a median of 4·86 times (IQR 4·38-7·97; p=0·0001) and 3·48 times (2·05-4·09; p=0·0001), respectively, at day 8 (give or take 2 days). At the same timepoint, relative MDM2 mRNA expression had increased by a median of 3·03 times (1·23-4·93; p=0·003) that at baseline. The median change from baseline for Ki-67-positive tumour cells was -5·05% (IQR -12·55 to 0·05; p=0·01). Drug exposure correlated with blood concentrations of MIC-1 (p<0·0001) and haematological toxicity. One patient had a confirmed partial response and 14 had stable disease. All patients experienced at least one adverse event, mostly nausea (14 patients), vomiting (11 patients), asthenia (nine patients), diarrhoea (nine patients), and thrombocytopenia (eight patients). There were 12 serious adverse events in eight patients, the most common of which were neutropenia (six patients) and thrombocytopenia (three patients). MDM2 inhibition activates the P53 pathway and decreases cell proliferation in MDM2-amplified liposarcoma. This study suggests that it is feasible to undertake neoadjuvant biopsy-driven biomarker studies in liposarcoma. F Hoffmann-La Roche. Copyright © 2012 Elsevier Ltd. All rights reserved.

Algoriphagus aestuarii sp. nov., a member of the Cyclobacteriaceae isolated from a tidal-flat sediment of the Yellow Sea in Korea.

PubMed

Jung, Yong-Taek; Lee, Jung-Sook; Yoon, Jung-Hoon

2015-10-01

A Gram-strain-negative, coccoid or oval-shaped, non-motile bacterial strain, designated MDM-1T, was isolated from a tidal-flat sediment on the Korean peninsula. Strain MDM-1T was found to grow optimally at pH 7.0-8.0, at 30 °C and in the presence of 2-3 % (w/v) NaCl. A neighbour-joining phylogenetic tree based on 16S rRNA gene sequences showed that strain MDM-1T falls within the clade comprising species of the genus Algoriphagus, clustering with the type strains of Algoriphagus halophilus, A. lutimaris, A. chungangensis and A. machipongonensis, with which it exhibited 97.2-98.5 % 16S rRNA gene sequence similarity. Sequence similarities to the type strains of the other recognized species of the genus Algoriphagus were 92.8-97.6 %. Strain MDM-1T was found to contain MK-7 as the predominant menaquinone and iso-C15 : 0 and summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c) as the major fatty acids. The major polar lipids were identified as phosphatidylcholine, phosphatidylethanolamine and two unidentified lipids. The DNA G+C content of strain MDM-1T was determined to be 42.7 mol% and the mean DNA-DNA relatedness with A. halophilus KCTC 12051T, A. lutimaris S1-3T, A. chungangensis KCTC 23759T, A. machipongonensis DSM 24695T and A. ratkowskyi CIP 107452T was 19.7-5.2 %. Differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that strain MDM-1T is distinguishable from recognized species of the genus Algoriphagus. On the basis of the data presented, strain MDM-1T is proposed to represent a novel species of the genus Algoriphagus, for which the name Algoriphagus aestuarii sp. nov. is proposed. The type strain is MDM-1T ( = KCTC 42199T = NBRC 110552T).

40Gbit/s MDM-WDM Laguerre-Gaussian Mode with Equalization for Multimode Fiber in Access Networks

NASA Astrophysics Data System (ADS)

Fazea, Yousef; Amphawan, Angela

2018-04-01

Modal dispersion is seen as the primary impairment for multimode fiber. Mode division multiplexing (MDM) is a promising technology that has been realized as a favorable technology for considerably upsurges the capacity and distance of multimode fiber in conjunction with Wavelength Division Multiplexing (WDM) for fiber-to-the-home. This paper reveals the importance of an equalization technique in conjunction with controlling the modes spacing of mode division multiplexing-wavelength division multiplexing of Laguerre-Gaussian modes to alleviate modal dispersion for multimode fiber. The effects of channel spacing of 20 channels MDM-WDM were examined through controlling the azimuthal mode number and the radial mode number of Laguerre-Gaussian modes. A data rate of 40Gbit/s was achieved for a distance of 1,500 m for MDM-WDM.

Disturbed P53-MDM2 Feedback Loop Contributes to Thoracic Aortic Dissection Formation and May be a Result of TRIM25 Overexpression.

PubMed

Gong, Bin; Wang, Zhiwei; Zhang, Min; Hu, Zhipeng; Ren, Zongli; Tang, Zheng; Jiang, Wanli; Cheng, Lianghao; Huang, Jun; Ren, Wei; Wang, Qingtao

2017-04-01

The development of thoracic aortic dissection (TAD) is attributed to a broad range of degenerative, genetic, structural, oxidative, apoptotic, and acquired disease states. In this study, we examined the role of the disturbed p53-MDM2 (murine double minute 2) feedback loop in the formation of TAD, and one of a potential feedback loop regulator, TRIM25 (tripartite motif protein-25). Surgical specimens of the aorta from TAD patients (n = 10) and controls (n = 10) were tested for α-smooth muscle actin (α-SMA), p53, MDM2, and TRIM25 by western blot, immunohistochemical staining, and quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR), respectively. When compared with controls, western blot shows that the protein levels of p53, MDM2, and TRIM25 were increased significantly in the aortic media of TAD patients. qRT-PCR further verified that the mRNA expression of MDM2 and TRIM25 was also increased 6- and 4-folds, respectively, in the TAD media of the aortic wall. Immunohistochemistry results showed significantly decreased staining of α-SMA, smooth muscle cells, and more collagen deposition in the media of the aortic wall from patients with TAD. This study provided a new insight into the disturbed p53-MDM2 feedback loop in the pathogenesis of TAD, and this may be because of the TRIM25 overexpression. Copyright © 2016 Elsevier Inc. All rights reserved.

Ultrapressure liquid chromatography-tandem mass spectrometry assay using atmospheric pressure photoionization (UPLC-APPI-MS/MS) for quantification of 4-methoxydiphenylmethane in pharmacokinetic evaluation.

PubMed

Farhan, Nashid; Fitzpatrick, Sean; Shim, Yun M; Paige, Mikell; Chow, Diana Shu-Lian

2016-09-05

4-Methoxydiphenylmethane (4-MDM), a selective augmenter of Leukotriene A4 Hydrolase (LTA4H), is a new anti-inflammatory compound for potential treatment of chronic obstructive pulmonary disease (COPD). Currently, there is no liquid chromatography tandem mass spectrometric (LC-MS/MS) method for the quantification of 4-MDM. A major barrier for developing the LC-MS/MS method is the inability of electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) to ionize 4-MDM due to its hydrophobicity and lack of any functional group for ionization. With the advent of atmospheric pressure photoionization (APPI) technique, many hydrophobic compounds have been demonstrated to ionize by charge transfer reactions. In this study, a highly sensitive ultrapressure liquid chromatography tandem mass spectrometry assay using atmospheric pressure photoionization (UPLC-APPI-MS/MS) for the quantifications of 4-MDM in rat plasma has been developed and validated. 4-MDM was extracted from the plasma by solid phase extraction (SPE) and separated chromatographically using a reverse phase C8 column. The photoionization (PI) was achieved by introducing anisole as a dopant to promote the reaction of charge transfer. The assay with a linear range of 5 (LLOQ)-400ngmL(-1) met the regulatory requirements for accuracy, precision and stability. The validated assay was employed to quantify the plasma concentrations of 4-MDM after an oral dosing in Sprague Dawley (SD) rats. Copyright © 2016 Elsevier B.V. All rights reserved.

Oral nano-delivery of anticancer ginsenoside 25-OCH3-PPD, a natural inhibitor of the MDM2 oncogene: Nanoparticle preparation, characterization, in vitro and in vivo anti-prostate cancer activity, and mechanisms of action.

PubMed

Voruganti, Sukesh; Qin, Jiang-Jiang; Sarkar, Sushanta; Nag, Subhasree; Walbi, Ismail A; Wang, Shu; Zhao, Yuqing; Wang, Wei; Zhang, Ruiwen

2015-08-28

The Mouse Double Minute 2 (MDM2) oncogene plays a critical role in cancer development and progression through p53-dependent and p53-independent mechanisms. Both natural and synthetic MDM2 inhibitors have been shown anticancer activity against several human cancers. We have recently identified a novel ginsenoside, 25-OCH3-PPD (GS25), one of the most active anticancer ginsenosides discovered thus far, and have demonstrated its MDM2 inhibition and anticancer activity in various human cancer models, including prostate cancer. However, the oral bioavailability of GS25 is limited, which hampers its further development as an oral anticancer agent. The present study was designed to develop a novel nanoparticle formulation for oral delivery of GS25. After GS25 was successfully encapsulated into PEG-PLGA nanoparticles (GS25NP) and its physicochemical properties were characterized, the efficiency of MDM2 targeting, anticancer efficacy, pharmacokinetics, and safety were evaluated in in vitro and in vivo models of human prostate cancer. Our results indicated that, compared with the unencapsulated GS25, GS25NP demonstrated better MDM2 inhibition, improved oral bioavailability and enhanced in vitro and in vivo activities. In conclusion, the validated nano-formulation for GS25 oral delivery improves its molecular targeting, oral bioavailability and anticancer efficacy, providing a basis for further development of GS25 as a novel agent for cancer therapy and prevention.

The ubiquitin ligase Mdm2 controls oligodendrocyte maturation by intertwining mTOR with G protein-coupled receptor kinase 2 in the regulation of GPR17 receptor desensitization.

PubMed

Fumagalli, Marta; Bonfanti, Elisabetta; Daniele, Simona; Zappelli, Elisa; Lecca, Davide; Martini, Claudia; Trincavelli, Maria L; Abbracchio, Maria P

2015-12-01

During oligodendrocyte precursor cell (OPC) differentiation, defective control of the membrane receptor GPR17 has been suggested to block cell maturation and impair remyelination under demyelinating conditions. After the immature oligodendrocyte stage, to enable cells to complete maturation, GPR17 is physiologically down-regulated via phosphorylation/desensitization by G protein-coupled receptor kinases (GRKs); conversely, GRKs are regulated by the "mammalian target of rapamycin" mTOR. However, how GRKs and mTOR are connected to each other in modulating GPR17 function and oligodendrogenesis has remained elusive. Here we show, for the first time, a role for Murine double minute 2 (Mdm2), a ligase previously involved in ubiquitination/degradation of the onco-suppressor p53 protein. In maturing OPCs, both rapamycin and Nutlin-3, a small molecule inhibitor of Mdm2-p53 interactions, increased GRK2 sequestration by Mdm2, leading to impaired GPR17 down-regulation and OPC maturation block. Thus, Mdm2 intertwines mTOR with GRK2 in regulating GPR17 and oligodendrogenesis and represents a novel actor in myelination. © 2015 Wiley Periodicals, Inc.

Novel MDM2 inhibitor SAR405838 (MI-773) induces p53-mediated apoptosis in neuroblastoma

PubMed Central

Lu, Jiaxiong; Guan, Shan; Zhao, Yanling; Yu, Yang; Wang, Yongfeng; Shi, Yonghua; Mao, Xinfang; Yang, Kristine L.; Sun, Wenjing; Xu, Xin; Yi, Joanna S.; Yang, Tianshu; Yang, Jianhua; Nuchtern, Jed G.

2016-01-01

Neuroblastoma (NB), which accounts for about 15% of cancer-related mortality in children, is the most common childhood extracranial malignant tumor. In NB, somatic mutations of the tumor suppressor, p53, are exceedingly rare. Unlike in adult tumors, the majority of p53 downstream functions are still intact in NB cells with wild-type p53. Thus, restoring p53 function by blocking its interaction with p53 suppressors such as MDM2 is a viable therapeutic strategy for NB treatment. Herein, we show that MDM2 inhibitor SAR405838 is a potent therapeutic drug for NB. SAR405838 caused significantly decreased cell viability of p53 wild-type NB cells and induced p53-mediated apoptosis, as well as augmenting the cytotoxic effects of doxorubicin (Dox). In an in vivo orthotopic NB mouse model, SAR405838 induced apoptosis in NB tumor cells. In summary, our data strongly suggest that MDM2-specific inhibitors like SAR405838 may serve not only as a stand-alone therapy, but also as an effective adjunct to current chemotherapeutic regimens for treating NB with an intact MDM2-p53 axis. PMID:27764791

Targeting MDM2 by the small molecule RITA: towards the development of new multi-target drugs against cancer

PubMed Central

Espinoza-Fonseca, L Michel

2005-01-01

Background The use of low-molecular-weight, non-peptidic molecules that disrupt the interaction between the p53 tumor suppressor and its negative regulator MDM2 has provided a promising alternative for the treatment of different types of cancer. Among these compounds, RITA (reactivation of p53 and induction of tumor cell apoptosis) has been shown to be effective in the selective induction of apoptosis, and this effect is due to its binding to the p53 tumor suppressor. Since biological systems are highly dynamic and MDM2 may bind to different regions of p53, new alternatives should be explored. On this basis, the computational "blind docking" approach was employed in this study to see whether RITA would bind to MDM2. Results It was observed that RITA binds to the MDM2 p53 transactivation domain-binding cleft. Thus, RITA can be used as a lead compound for designing improved "multi-target" drugs. This novel strategy could provide enormous benefits to enable effective anti-cancer strategies. Conclusion This study has demonstrated that a single molecule can target at least two different proteins related to the same disease. PMID:16174299

Overexpression of SKI Oncoprotein Leads to p53 Degradation through Regulation of MDM2 Protein Sumoylation*

PubMed Central

Ding, Boxiao; Sun, Yin; Huang, Jiaoti

2012-01-01

Protooncogene Ski was identified based on its ability to transform avian fibroblasts in vitro. In support of its oncogenic activity, SKI was found to be overexpressed in a variety of human cancers, although the exact molecular mechanism(s) responsible for its oncogenic activity is not fully understood. We found that SKI can negatively regulate p53 by decreasing its level through up-regulation of MDM2 activity, which is mediated by the ability of SKI to enhance sumoylation of MDM2. This stimulation of MDM2 sumoylation is accomplished through a direct interaction of SKI with SUMO-conjugating enzyme E2, Ubc9, resulting in enhanced thioester bond formation and mono-sumoylation of Ubc9. A mutant SKI defective in transformation fails to increase p53 ubiquitination and is unable to increase MDM2 levels and to increase mono-sumoylation of Ubc9, suggesting that the ability of SKI to enhance Ubc9 activity is essential for its transforming function. These results established a detailed molecular mechanism that underlies the ability of SKI to cause cellular transformation while unraveling a novel connection between sumoylation and tumorigenesis, providing potential new therapeutic targets for cancer. PMID:22411991

Inhibition of Mdm2 Sensitizes Human Retinal Pigment Epithelial Cells to Apoptosis

PubMed Central

Ray, Ramesh M.; Chaum, Edward; Johnson, Dianna A.; Johnson, Leonard R.

2011-01-01

Purpose. Because recent studies indicate that blocking the interaction between p53 and Mdm2 results in the nongenotoxic activation of p53, the authors sought to investigate whether the inhibition of p53-Mdm2 binding activates p53 and sensitizes human retinal epithelial cells to apoptosis. Methods. Apoptosis was evaluated by the activation of caspases and DNA fragmentation assays. The Mdm2 antagonist Nutlin-3 was used to dissociate p53 from Mdm2 and, thus, to increase p53 activity. Knockdown of p53 expression was accomplished by using p53 siRNA. Results. ARPE-19 and primary RPE cells expressed high levels of the antiapoptotic proteins Bcl-2 and Bcl-xL. Exposure of these cells to camptothecin (CPT) or TNF-α/ cycloheximide (CHX) failed to induce apoptosis. In contrast, treatment with the Mdm2 antagonist Nutlin-3 in the absence of CPT or TNF-α/CHX increased apoptosis. Activation of p53 in response to Nutlin-3 also increased levels of Noxa, p53-upregulated modulator of apoptosis (PUMA), and Siva-1, decreased expression of Bcl-2 and Bcl-xL, and simultaneously increased caspases-9 and -3 activities and DNA fragmentation. Knockdown of p53 decreased the basal expression of p21Cip1 and Bcl-2, inhibited the Nutlin-3–induced upregulation of Siva-1 and PUMA expression, and consequently inhibited caspase-3 activation. Conclusions. These results indicate that the normally available pool of intracellular p53 is predominantly engaged in the regulation of cell cycle checkpoints by p21Cip1 and does not trigger apoptosis in response to DNA-damaging agents. However, the blockage of p53 binding to Mdm2 frees a pool of p53 that is sufficient, even in the absence of DNA-damaging agents, to increase the expression of proapoptotic targets and to override the resistance of RPE cells to apoptosis. PMID:21345989

Discovery of 4-((3'R,4'S,5'R)-6″-Chloro-4'-(3-chloro-2-fluorophenyl)-1'-ethyl-2″-oxodispiro[cyclohexane-1,2'-pyrrolidine-3',3″-indoline]-5'-carboxamido)bicyclo[2.2.2]octane-1-carboxylic Acid (AA-115/APG-115): A Potent and Orally Active Murine Double Minute 2 (MDM2) Inhibitor in Clinical Development.

PubMed

Aguilar, Angelo; Lu, Jianfeng; Liu, Liu; Du, Ding; Bernard, Denzil; McEachern, Donna; Przybranowski, Sally; Li, Xiaoqin; Luo, Ruijuan; Wen, Bo; Sun, Duxin; Wang, Hengbang; Wen, Jianfeng; Wang, Guangfeng; Zhai, Yifan; Guo, Ming; Yang, Dajun; Wang, Shaomeng

2017-04-13

We previously reported the design of spirooxindoles with two identical substituents at the carbon-2 of the pyrrolidine core as potent MDM2 inhibitors. In this paper we describe an extensive structure-activity relationship study of this class of MDM2 inhibitors, which led to the discovery of 60 (AA-115/APG-115). Compound 60 has a very high affinity to MDM2 (K i < 1 nM), potent cellular activity, and an excellent oral pharmacokinetic profile. Compound 60 is capable of achieving complete and long-lasting tumor regression in vivo and is currently in phase I clinical trials for cancer treatment.

Three-mode mode-division-multiplexing passive optical network over 12-km low mode-crosstalk FMF using all-fiber mode MUX/DEMUX

NASA Astrophysics Data System (ADS)

Ren, Fang; Li, Juhao; Wu, Zhongying; Hu, Tao; Yu, Jinyi; Mo, Qi; He, Yongqi; Chen, Zhangyuan; Li, Zhengbin

2017-01-01

We propose three-mode mode-division-multiplexing passive optical network (MDM-PON) based on low mode-crosstalk few-mode fiber (FMF) and all-fiber mode multiplexer/demultiplexer (MUX/DEMUX). The FMF with step-index profile is designed and fabricated for effectively three-independent-spatial-mode transmission and low mode-crosstalk for MDM-PON transmission. The all-fiber mode MUX/DEMUX are composed of cascaded mode selective couplers (MSCs), which simultaneously multiplex or demultiplex multiple modes. Based on the low mode-crosstalk of the FMF and all-fiber mode MUX/DEMUX, each optical network unit (ONU) communicates with the optical line terminal (OLT) independently utilizing a different optical linearly polarized (LP) spatial mode in MDM-PON system. We experimentally demonstrate MDM-PON transmission of three independent-spatial-modes over 12-km FMF with 10-Gb/s optical on-off keying (OOK) signal and direct detection.

Acrolein preferentially damages nucleolus eliciting ribosomal stress and apoptosis in human cancer cells.

PubMed

Wang, Hsiang-Tsui; Chen, Tzu-Ying; Weng, Ching-Wen; Yang, Chun-Hsiang; Tang, Moon-Shong

2016-12-06

Acrolein (Acr) is a potent cytotoxic and DNA damaging agent which is ubiquitous in the environment and abundant in tobacco smoke. Acr is also an active cytotoxic metabolite of the anti-cancer drugs cyclophosphamide and ifosfamide. The mechanisms via which Acr exerts its anti-cancer activity and cytotoxicity are not clear. In this study, we found that Acr induces cytotoxicity and cell death in human cancer cells with different activities of p53. Acr preferentially binds nucleolar ribosomal DNA (rDNA) to form Acr-deoxyguanosine adducts, and induces oxidative damage to both rDNA and ribosomal RNA (rRNA). Acr triggers ribosomal stress responses, inhibits rRNA synthesis, reduces RNA polymerase I binding to the promoter of rRNA gene, disrupts nucleolar integrity, and impairs ribosome biogenesis and polysome formation. Acr causes an increase in MDM2 levels and phosphorylation of MDM2 in A549 and HeLa cells which are p53 active and p53 inactive, respectively. It enhances the binding of ribosomal protein RPL11 to MDM2 and reduces the binding of p53 and E2F-1 to MDM2 resulting in stabilization/activation of p53 in A549 cells and degradation of E2F-1 in A549 and HeLa cells. We propose that Acr induces ribosomal stress which leads to activation of MDM2 and RPL11-MDM2 binding, consequently, activates p53 and enhances E2F-1 degradation, and that taken together these two processes induce apoptosis and cell death.

A novel small molecule inhibitor of MDM2-p53 (APG-115) enhances radiosensitivity of gastric adenocarcinoma.

PubMed

Yi, Hanjie; Yan, Xianglei; Luo, Qiuyun; Yuan, Luping; Li, Baoxia; Pan, Wentao; Zhang, Lin; Chen, Haibo; Wang, Jing; Zhang, Yubin; Zhai, Yifan; Qiu, Miao-Zhen; Yang, Da-Jun

2018-05-02

Gastric cancer is the leading cause of cancer related death worldwide. Radiation alone or combined with chemotherapy plays important role in locally advanced and metastatic gastric adenocarcinoma. MDM2-p53 interaction and downstream signaling affect cellular response to DNA damage which leads to cell cycle arrest and apoptosis. Therefore, restoring p53 function by inhibiting its interaction with MDM2 is a promising therapeutic strategy for cancer. APG-115 is a novel small molecule inhibitor which blocks the interaction of MDM2 and p53. In this study, we investigated that the radiosensitivity of APG-115 in gastric adenocarcinoma in vitro and in vivo. The role of APG-115 in six gastric cancer cells viability in vitro was determined by CCK-8 assay. The expression level of MDM2, p21, PUMA and BAX in AGS and MKN45 cell lines was measured via real-time PCR (RT-PCR). The function of treatment groups on cell cycle and cell apoptosis were detected through Flow Cytometry assay. Clonogenic assays were used to measure the radiosensitivity of APG-115 in p53 wild type gastric cancer cell lines. Western blot was conducted to detect the protein expressions of mdm2-p53 signal pathway. Xenograft models in nude mice were established to explore the radiosensitivity role of APG-115 in gastric cancer cells in vivo. We found that radiosensitization by APG-115 occurred in p53 wild-type gastric cancer cells. Increasing apoptosis and cell cycle arrest was observed after administration of APG-115 and radiation. Radiosensitivity of APG-115 was mainly dependent on MDM2-p53 signal pathway. In vivo, APG-115 combined with radiation decreased xenograft tumor growth much more significantly than either single treatment. Moreover, the number of proliferating cells (Ki-67) significantly decreased in combination group compared with single treatment group. In summary, we found that combination of MDM2-p53 inhibitor (APG-115) and radiotherapy can enhance antitumor effect both in vitro and in vivo. This is the first report on radiosensitivity of APG-115 which shed light on clinical trial of the combination therapy of radiation with APG-115 in gastric adenocarcinoma.

Sensing performance analysis on Fano resonance of metallic double-baffle contained MDM waveguide coupled ring resonator

NASA Astrophysics Data System (ADS)

Chen, Ying; Luo, Pei; Liu, Xiaofei; Di, Yuanjian; Han, Shuaitao; Cui, Xingning; He, Lei

2018-05-01

Based on the transmission property and the photon localization characteristic of the surface plasmonic sub-wavelength structure, a metallic double-baffle contained metal-dielectric-metal (MDM) waveguide coupled ring resonator is proposed. Like the electromagnetically induced transparency (EIT), the Fano resonance can be achieved by the interference between the metallic double-baffle resonator and the ring resonator. Based on the coupled mode theory, the transmission property is analyzed. Through the numerical simulation by the finite element method (FEM), the quantitative analysis on the influences of the radius R of the ring and the coupling distance g between the metallic double-baffle resonator and the ring resonator for the figure of merit (FOM) is performed. And after the structure parameter optimization, the sensing performance of the waveguide structure is discussed. The simulation results show that the FOM value of the optimized structure can attain to 5.74 ×104 and the sensitivity of resonance wavelength with refractive index drift is about 825 nm/RIU. The range of the detected refractive index is suitable for all gases. The waveguide structure can provide effective theoretical references for the design of integrated plasmonic devices.

Multi data mode method as an alternative way for SPM studies of high relief surfaces

NASA Astrophysics Data System (ADS)

Abdullayeva, S. H.; Molchanov, S. P.; Mamedov, N. T.; Alekperov, S. D.

2006-09-01

In this paper we report the results of our studies of the high relief surfaces of Al oxide-based ceramic catalyst by SPM contact mode, and by so-called Multi Data Mode (MDM) method for comparison. We failed to obtain any reasonable image of the highly-developed surfaces of above material by the first method but were successful in doing so when applied the second one. The topographic and complimentary images obtained by MDM probing with high resolution are discussed to show a full range of the applications possible using MDM.

The expression of MDM2/CDK4 gene product in the differential diagnosis of well differentiated liposarcoma and large deep-seated lipoma

PubMed Central

Pilotti, S; Torre, G Della; Mezzelani, A; Tamborini, E; Azzarelli, A; Sozzi, G; Pierotti, M A

2000-01-01

Ordinary lipomas are cytogenetically characterized by a variety of balanced rearrangements involving chromosome segment 12q13–15, whereas well differentiated liposarcomas (WDL) show supernumerary ring and giant marker chromosomes, known to contain amplified 12q sequences. The tight correlation between the presence of ring chromosomes and both amplification and overexpression of MDM2 and CDK4 genes suggests the exploration of the possibility that immunocytochemistry (ICC) might assist in the differential diagnosis of lipoma-like well differentiated liposarcomas (LL-WDL) and large deep-seated lipomas (LDSL). For this purpose, 21 cases of the former and 19 cases of the latter tumours were analysed by ICC and, according to the availability of material, by molecular and cytogenetic approaches. All lipomas displayed a null MDM2/CDK4 phenotype, whereas all LL-WDL showed MDM2/CDK4 or CDK4 phenotypes. Southern blot analysis performed on 16 suitable cases, complemented by fluorescence in situ hybridization and classical cytogenetic analysis in 11 cases, was consistent with, and further supported the immunophenotyping data. In conclusion, MDM2/CDK4 product-based immunophenotyping appears to represent a valuable method for the categorization of arguable LDSL. © 2000 Cancer Research Campaign PMID:10755400

ATP Induces IL-1β Secretion in Neisseria gonorrhoeae-Infected Human Macrophages by a Mechanism Not Related to the NLRP3/ASC/Caspase-1 Axis

PubMed Central

García, Killen; Escobar, Gisselle; Mendoza, Pablo; Beltran, Caroll; Perez, Claudio; Vernal, Rolando; Acuña-Castillo, Claudio

2016-01-01

Neisseria gonorrhoeae (Ngo) has developed multiple immune evasion mechanisms involving the innate and adaptive immune responses. Recent findings have reported that Ngo reduces the IL-1β secretion of infected human monocyte-derived macrophages (MDM). Here, we investigate the role of adenosine triphosphate (ATP) in production and release of IL-1β in Ngo-infected MDM. We found that the exposure of Ngo-infected MDM to ATP increases IL-1β levels about ten times compared with unexposed Ngo-infected MDM (P < 0.01). However, we did not observe any changes in inflammasome transcriptional activation of speck-like protein containing a caspase recruitment domain (CARD) (ASC, P > 0.05) and caspase-1 (CASP1, P > 0.05). In addition, ATP was not able to modify caspase-1 activity in Ngo-infected MDM but was able to increase pyroptosis (P > 0.01). Notably ATP treatment defined an increase of positive staining for IL-1β with a distinctive intracellular pattern of distribution. Collectively, these data demonstrate that ATP induces IL-1β secretion by a mechanism not related to the NLRP3/ASC/caspase-1 axis and likely is acting at the level of vesicle trafficking or pore formation. PMID:27803513

Targeting p53-MDM2-MDMX Loop for Cancer Therapy

PubMed Central

Zhang, Qi; Zeng, Shelya X.

2015-01-01

The tumor suppressor p53 plays a central role in anti-tumorigenesis and cancer therapy. It has been described as “the guardian of the genome”, because it is essential for conserving genomic stability by preventing mutation, and its mutation and inactivation are highly related to all human cancers. Two important p53 regulators, MDM2 and MDMX, inactivate p53 by directly inhibiting its transcriptional activity and mediating its ubiquitination in a feedback fashion, as their genes are also the transcriptional targets of p53. On account of the importance of the p53-MDM2- MDMX loop in the initiation and development of wild type p53-containing tumors, intensive studies over the past decade have been aiming to identify small molecules or peptides that could specifically target individual protein molecules of this pathway for developing better anti-cancer therapeutics. In this chapter, we review the approaches for screening and discovering efficient and selective MDM2 inhibitors with emphasis on the most advanced synthetic small molecules that interfere with the p53-MDM2 interaction and are currently on Phase I clinical trials. Other therapeutically useful strategies targeting this loop, which potentially improve the prospects of cancer therapy and prevention, will also be discussed briefly. PMID:25201201

15 CFR 230.7 - Description of services and list of fees, incorporation by reference.

Code of Federal Regulations, 2010 CFR

2010-01-01

... STANDARD REFERENCE MATERIALS STANDARD REFERENCE MATERIALS Description of Services and List of Fees § 230.7 Description of services and list of fees, incorporation by reference. (a) The text of NIST Special Publication... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Description of services and list of...

Adaptive HIV-Specific B Cell-Derived Humoral Immune Defenses of the Intestinal Mucosa in Children Exposed to HIV via Breast-Feeding

PubMed Central

Moussa, Sandrine; Jenabian, Mohammad-Ali; Gody, Jean Chrysostome; Léal, Josiane; Grésenguet, Gérard; Le Faou, Alain; Bélec, Laurent

2013-01-01

Background We evaluated whether B cell-derived immune defenses of the gastro-intestinal tract are activated to produce HIV-specific antibodies in children continuously exposed to HIV via breast-feeding. Methods Couples of HIV-1-infected mothers (n = 14) and their breastfed non HIV-infected (n = 8) and HIV-infected (n = 6) babies, and healthy HIV-negative mothers and breastfed babies (n = 10) as controls, were prospectively included at the Complexe Pédiatrique of Bangui, Central African Republic. Immunoglobulins (IgA, IgG and IgM) and anti-gp160 antibodies from mother’s milk and stools of breastfed children were quantified by ELISA. Immunoaffinity purified anti-gp160 antibodies were characterized functionally regarding their capacity to reduce attachment and/or infection of R5- and X4- tropic HIV-1 strains on human colorectal epithelial HT29 cells line or monocyte-derived-macrophages (MDM). Results The levels of total IgA and IgG were increased in milk of HIV-infected mothers and stools of HIV-exposed children, indicating the activation of B cell-derived mucosal immunity. Breast milk samples as well as stool samples from HIV-negative and HIV-infected babies exposed to HIV by breast-feeding, contained high levels of HIV-specific antibodies, mainly IgG antibodies, less frequently IgA antibodies, and rarely IgM antibodies. Relative ratios of excretion by reference to lactoferrin calculated for HIV-specific IgA, IgG and IgM in stools of HIV-exposed children were largely superior to 1, indicating active production of HIV-specific antibodies by the intestinal mucosa. Antibodies to gp160 purified from pooled stools of HIV-exposed breastfed children inhibited the attachment of HIV-1NDK on HT29 cells by 63% and on MDM by 77%, and the attachment of HIV-1JRCSF on MDM by 40%; and the infection of MDM by HIV-1JRCSF by 93%. Conclusions The intestinal mucosa of children exposed to HIV by breast-feeding produces HIV-specific antibodies harbouring in vitro major functional properties against HIV. These observations lay the conceptual basis for the design of a prophylactic vaccine against HIV in exposed children. PMID:23704905

Viral Infection of Human Lung Macrophages Increases PDL1 Expression via IFNβ

PubMed Central

Staples, Karl J.; Nicholas, Ben; McKendry, Richard T.; Spalluto, C. Mirella; Wallington, Joshua C.; Bragg, Craig W.; Robinson, Emily C.; Martin, Kirstin; Djukanović, Ratko; Wilkinson, Tom M. A.

2015-01-01

Lung macrophages are an important defence against respiratory viral infection and recent work has demonstrated that influenza-induced macrophage PDL1 expression in the murine lung leads to rapid modulation of CD8+ T cell responses via the PD1 receptor. This PD1/PDL1 pathway may downregulate acute inflammatory responses to prevent tissue damage. The aim of this study was to investigate the mechanisms of PDL1 regulation by human macrophages in response to viral infection. Ex-vivo viral infection models using influenza and RSV were established in human lung explants, isolated lung macrophages and monocyte-derived macrophages (MDM) and analysed by flow cytometry and RT-PCR. Incubation of lung explants, lung macrophages and MDM with X31 resulted in mean cellular infection rates of 18%, 18% and 29% respectively. Viral infection significantly increased cell surface expression of PDL1 on explant macrophages, lung macrophages and MDM but not explant epithelial cells. Infected MDM induced IFNγ release from autologous CD8+ T cells, an effect enhanced by PDL1 blockade. We observed increases in PDL1 mRNA and IFNβ mRNA and protein release by MDM in response to influenza infection. Knockdown of IFNβ by siRNA, resulted in a 37.5% reduction in IFNβ gene expression in response to infection, and a significant decrease in PDL1 mRNA. Furthermore, when MDM were incubated with IFNβ, this cytokine caused increased expression of PDL1 mRNA. These data indicate that human macrophage PDL1 expression modulates CD8+ cell IFNγ release in response to virus and that this expression is regulated by autologous IFNβ production. PMID:25775126

Viral infection of human lung macrophages increases PDL1 expression via IFNβ.

PubMed

Staples, Karl J; Nicholas, Ben; McKendry, Richard T; Spalluto, C Mirella; Wallington, Joshua C; Bragg, Craig W; Robinson, Emily C; Martin, Kirstin; Djukanović, Ratko; Wilkinson, Tom M A

2015-01-01

Lung macrophages are an important defence against respiratory viral infection and recent work has demonstrated that influenza-induced macrophage PDL1 expression in the murine lung leads to rapid modulation of CD8+ T cell responses via the PD1 receptor. This PD1/PDL1 pathway may downregulate acute inflammatory responses to prevent tissue damage. The aim of this study was to investigate the mechanisms of PDL1 regulation by human macrophages in response to viral infection. Ex-vivo viral infection models using influenza and RSV were established in human lung explants, isolated lung macrophages and monocyte-derived macrophages (MDM) and analysed by flow cytometry and RT-PCR. Incubation of lung explants, lung macrophages and MDM with X31 resulted in mean cellular infection rates of 18%, 18% and 29% respectively. Viral infection significantly increased cell surface expression of PDL1 on explant macrophages, lung macrophages and MDM but not explant epithelial cells. Infected MDM induced IFNγ release from autologous CD8+ T cells, an effect enhanced by PDL1 blockade. We observed increases in PDL1 mRNA and IFNβ mRNA and protein release by MDM in response to influenza infection. Knockdown of IFNβ by siRNA, resulted in a 37.5% reduction in IFNβ gene expression in response to infection, and a significant decrease in PDL1 mRNA. Furthermore, when MDM were incubated with IFNβ, this cytokine caused increased expression of PDL1 mRNA. These data indicate that human macrophage PDL1 expression modulates CD8+ cell IFNγ release in response to virus and that this expression is regulated by autologous IFNβ production.

Improved immediate breast reconstruction as a result of oncoplastic multidisciplinary meeting.

PubMed

El Gammal, Mohsen M; Lim, Maria; Uppal, Rajan; Sainsbury, Richard

2017-01-01

The National Institute for Health and Clinical Excellence guidelines recommend that breast reconstruction should be available to all women undergoing mastectomy and discussed at the initial surgical consultation (2002, and updated 2009). The National Mastectomy and Breast Reconstruction Audit (2009) showed that 21% of mastectomy patients underwent immediate breast reconstruction (IBR) and 11% had delayed breast reconstruction (DBR). Breast reconstruction has been shown to have a positive effect on quality of life postmastectomy. This retrospective study investigated the impact of the introduction of a dedicated oncoplastic multidisciplinary meeting (OP MDM) on our unit's breast reconstruction rate. A retrospective analysis of 229 women who underwent mastectomy, of whom 81 (35%) underwent breast reconstruction between April 2014 and March 2016. Data were analyzed before and after introduction of OP MDM in April 2015. Data on patient age, type of surgery (mastectomy only, mastectomy and reconstruction), timing of reconstruction (IBR, DBR), and type of reconstruction (implant, autologous) were collected. Between April 2015 and March 2016, following establishment of OP multidisciplinary team in April 2015, of the 120 patients who had mastectomy, 50 (42%) underwent breast reconstruction with 78% (39/50) choosing IBR (56% implant reconstruction and 22% autologous). Compared to the period between April 2014 and March 2015 preceding the OP MDM, of 109 patients who underwent mastectomy, only 31 (28%) had breast reconstruction with 64% (20/31) choosing IBR (45% implant reconstruction and 19% autologous). The rate of DBR was lower, 22% (11/50), following OP MDM compared to 35% (11/31) before OP MDM. There has been an increased uptake of breast reconstruction surgery from 28% to 42%. The biggest impact was on those opting for the immediate type reconstruction option (78%). The OP MDM has significantly contributed to this increased rate of reconstruction.

MDM2 and Ki-67 predict for distant metastasis and mortality in men treated with radiotherapy and androgen deprivation for prostate cancer: RTOG 92-02.

PubMed

Khor, Li-Yan; Bae, Kyounghwa; Paulus, Rebecca; Al-Saleem, Tahseen; Hammond, M Elizabeth; Grignon, David J; Che, Mingxin; Venkatesan, Varagur; Byhardt, Roger W; Rotman, Marvin; Hanks, Gerald E; Sandler, Howard M; Pollack, Alan

2009-07-01

PURPOSE MDM2 regulates p53, which controls cell cycle arrest and apoptosis. Both proteins, along with Ki-67, which is an established strong determinant of metastasis, have shown promise in predicting the outcome of men treated with radiation therapy (RT) with or without short-term androgen deprivation (STAD). This report compares the utility of abnormal expression of these biomarkers in estimating progression in a cohort of men treated on RTOG 92-02. PATIENTS AND METHODS Adequate tissue for immunohistochemistry was available for p53, Ki-67, and MDM2 analyses in 478 patient cases. The percentage of tumor nuclei staining positive (PSP) was quantified manually or by image analysis, and the per-sample mean intensity score (MIS) was quantified by image analysis. Cox regression models were used to estimate overall mortality (OM), and Fine and Gray's regressions were applied to the end points of distant metastasis (DM) and cause-specific mortality (CSM). Results In multivariate analyses that adjusted for all markers and treatment covariates, MDM2 overexpression was significantly related to DM (P = .02) and OM (P = .003), and Ki-67 overexpression was significantly related to DM (P < .0001), CSM (P = .0007), and OM (P = .01). P53 overexpression was significantly related to OM (P = .02). When considered in combination, the overexpression of both Ki-67 and MDM2 at high levels was associated with significantly increased failure rates for all end points (P < .001 for DM, CSM, and OM). CONCLUSION Combined MDM2 and Ki-67 expression levels were independently related to distant metastasis and mortality and, if validated, could be considered for risk stratification of patients with prostate cancer in clinical trials.

ALV-J strain SCAU-HN06 induces innate immune responses in chicken primary monocyte-derived macrophages.

PubMed

Feng, Min; Dai, Manman; Cao, Weisheng; Tan, Yan; Li, Zhenhui; Shi, Meiqing; Zhang, Xiquan

2017-01-01

Avian leucosis virus subgroup J (ALV-J) can cause lifelong infection and can escape from the host immune defenses in chickens. Since macrophages act as the important defense line against invading pathogens in host innate immunity, we investigated the function and innate immune responses of chicken primary monocyte-derived macrophages (MDM) after ALV-J infection in this study. Our results indicated that ALV-J was stably maintained in MDM cells but that the viral growth rate was significantly lower than that in DF-1 cells. We also found that ALV-J infection significantly increased nitric oxide (NO) production, but had no effect on MDM phagocytic capacity. Interestingly, infection with ALV-J rapidly promoted the expression levels of Myxovirus resistance 1 (Mx) (3 h, 6 h), ISG12 (6 h), and interleukin-1β (IL-1β) (3 h, 12 h) at an early infection stage, whereas it sharply decreased the expression of Mx (24 h, 36 h), ISG12 (36 h), and made little change on IL-1β (24 h, 36 h) production at a late infection stage in MDM cells. Moreover, the protein levels of interferon-β (IFN-β) and interleukin-6 (IL-6) had sharply increased in infected MDM cells from 3 to 36 h post infection (hpi) of ALV-J. And, the protein level of interleukin-10 (IL-10) was dramatically decreased at 36 hpi in MDM cells infected with ALV-J. These results demonstrate that ALV-J can induce host innate immune responses and we hypothesize that macrophages play an important role in host innate immune attack and ALV-J immune escape. © The Author 2016. Published by Oxford University Press on behalf of Poultry Science Association.

Preeclampsia Is Associated with Alterations in the p53-Pathway in Villous Trophoblast

PubMed Central

Sharp, Andrew N.; Heazell, Alexander E. P.; Baczyk, Dora; Dunk, Caroline E.; Lacey, Helen A.; Jones, Carolyn J. P.; Perkins, Jonathan E.; Kingdom, John C. P.; Baker, Philip N.; Crocker, Ian P.

2014-01-01

Background Preeclampsia (PE) is characterized by exaggerated apoptosis of the villous trophoblast of placental villi. Since p53 is a critical regulator of apoptosis we hypothesized that excessive apoptosis in PE is mediated by abnormal expression of proteins participating in the p53 pathway and that modulation of the p53 pathway alters trophoblast apoptosis in vitro. Methods Fresh placental villous tissue was collected from normal pregnancies and pregnancies complicated by PE; Western blotting and real-time PCR were performed on tissue lysate for protein and mRNA expression of p53 and downstream effector proteins, p21, Bax and caspases 3 and 8. To further assess the ability of p53 to modulate apoptosis within trophoblast, BeWo cells and placental villous tissue were exposed to the p53-activator, Nutlin-3, alone or in combination with the p53-inhibitor, Pifithrin-α (PFT- α). Equally, Mdm2 was knocked-down with siRNA. Results Protein expression of p53, p21 and Bax was significantly increased in pregnancies complicated by PE. Conversely, Mdm2 protein levels were significantly depleted in PE; immunohistochemistry showed these changes to be confined to trophoblast. Reduction in the negative feedback of p53 by Mdm2, using siRNA and Nutlin-3, caused an imbalance between p53 and Mdm2 that triggered apoptosis in term villous explants. In the case of Nutlin, this was attenuated by Pifithrin-α. Conclusions These data illustrate the potential for an imbalance in p53 and Mdm2 expression to promote excessive apoptosis in villous trophoblast. The upstream regulation of p53 and Mdm2, with regard to exaggerated apoptosis and autophagy in PE, merits further investigation. PMID:24498154

Preeclampsia is associated with alterations in the p53-pathway in villous trophoblast.

PubMed

Sharp, Andrew N; Heazell, Alexander E P; Baczyk, Dora; Dunk, Caroline E; Lacey, Helen A; Jones, Carolyn J P; Perkins, Jonathan E; Kingdom, John C P; Baker, Philip N; Crocker, Ian P

2014-01-01

Preeclampsia (PE) is characterized by exaggerated apoptosis of the villous trophoblast of placental villi. Since p53 is a critical regulator of apoptosis we hypothesized that excessive apoptosis in PE is mediated by abnormal expression of proteins participating in the p53 pathway and that modulation of the p53 pathway alters trophoblast apoptosis in vitro. Fresh placental villous tissue was collected from normal pregnancies and pregnancies complicated by PE; Western blotting and real-time PCR were performed on tissue lysate for protein and mRNA expression of p53 and downstream effector proteins, p21, Bax and caspases 3 and 8. To further assess the ability of p53 to modulate apoptosis within trophoblast, BeWo cells and placental villous tissue were exposed to the p53-activator, Nutlin-3, alone or in combination with the p53-inhibitor, Pifithrin-α (PFT-α). Equally, Mdm2 was knocked-down with siRNA. Protein expression of p53, p21 and Bax was significantly increased in pregnancies complicated by PE. Conversely, Mdm2 protein levels were significantly depleted in PE; immunohistochemistry showed these changes to be confined to trophoblast. Reduction in the negative feedback of p53 by Mdm2, using siRNA and Nutlin-3, caused an imbalance between p53 and Mdm2 that triggered apoptosis in term villous explants. In the case of Nutlin, this was attenuated by Pifithrin-α. These data illustrate the potential for an imbalance in p53 and Mdm2 expression to promote excessive apoptosis in villous trophoblast. The upstream regulation of p53 and Mdm2, with regard to exaggerated apoptosis and autophagy in PE, merits further investigation.

Low dose arsenite confers resistance to UV induced apoptosis via p53-MDM2 pathway in ketatinocytes

PubMed Central

Zhou, Y; Zeng, W; Qi, M; Duan, Y; Su, J; Zhao, S; Zhong, W; Gao, M; Li, F; He, Y; Hu, X; Xu, X; Chen, X; Peng, C; Zhang, J

2017-01-01

Chronic arsenite and ultraviolet (UV) exposure are associated with skin tumor. To investigate the details by low concentrations of arsenite and UV induced carcinogenesis in skin, hTERT-immortalized human keratinocytes were used as a cellular model with exposure to low concentrations of sodium arsenite and UV. The effect of NaAsO2 on UV treatment-induced apoptosis was measured by flow cytometry and Hoechst staining. We found that the cell apoptosis induced by UV exposure was significantly attenuated after exposure to low-dose arsenite, and knockdown of p53 could block UV-induced apoptosis indicating that this phenomenon depended on p53. Interestingly, the expression of murine double minute 2 (MDM2), including its protein and transcriptional levels, was remarkably high after exposure to low-dose arsenite. Moreover, low-dose arsenite treatment dramatically decreased the MDM2 gene promoter activity, suggesting that this effect has been mediated through transcription. In addition, treatment of PD98059 reversed low-dose arsenite-induced MDM2 expression, and the inhibition of ERK2 expression could significantly block MDM2 expression as a consequence, and p53 expression automatically was increased. To validate the role of p53 in exposure to low-dose arsenite, the expression of p53 was examined by immunohistochemistry in the skin of Sprague−Dawley rats model by chronic arsenite exposure for 6 months and in patients with arsenic keratosis, and the results showed that the expression of p53 was decreased in those samples. Taken together, our results demonstrated that low-dose arsenite-induced resistance to apoptosis through p53 mediated by MDM2 in keratinocytes. PMID:28785074

Combined ALK and MDM2 inhibition increases antitumor activity and overcomes resistance in human ALK mutant neuroblastoma cell lines and xenograft models.

PubMed

Wang, Hui Qin; Halilovic, Ensar; Li, Xiaoyan; Liang, Jinsheng; Cao, Yichen; Rakiec, Daniel P; Ruddy, David A; Jeay, Sebastien; Wuerthner, Jens U; Timple, Noelito; Kasibhatla, Shailaja; Li, Nanxin; Williams, Juliet A; Sellers, William R; Huang, Alan; Li, Fang

2017-04-20

The efficacy of ALK inhibitors in patients with ALK -mutant neuroblastoma is limited, highlighting the need to improve their effectiveness in these patients. To this end, we sought to develop a combination strategy to enhance the antitumor activity of ALK inhibitor monotherapy in human neuroblastoma cell lines and xenograft models expressing activated ALK. Herein, we report that combined inhibition of ALK and MDM2 induced a complementary set of anti-proliferative and pro-apoptotic proteins. Consequently, this combination treatment synergistically inhibited proliferation of TP53 wild-type neuroblastoma cells harboring ALK amplification or mutations in vitro, and resulted in complete and durable responses in neuroblastoma xenografts derived from these cells. We further demonstrate that concurrent inhibition of MDM2 and ALK was able to overcome ceritinib resistance conferred by MYCN upregulation in vitro and in vivo. Together, combined inhibition of ALK and MDM2 may provide an effective treatment for TP53 wild-type neuroblastoma with ALK aberrations.

Analysis of the MDM2 antagonist nutlin-3 in human prostate cancer cells.

PubMed

Logan, Ian R; McNeill, Hesta V; Cook, Susan; Lu, Xiaohong; Lunec, John; Robson, Craig N

2007-06-01

Small molecule MDM2 antagonists including nutlin-3 have been shown to be effective against a range of cancer cell types and nutlin-3 can inhibit growth of LNCaP xenografts. We compared the efficacy of nutlin-3 in three prostate cancer cell types and provide an insight into the mechanism of nutlin-3. Nutlin-3 efficacy was measured using proliferation assays, cell cycle analysis, apoptosis assays, quantitative RT-PCR, and immunoblotting. Chromatin immunoprecipitation (ChIP) assays were also performed. Nutlin-3 can specifically inhibit proliferation of LNCaP cells through cell cycle arrest and apoptosis. This coincides with increased levels of the p53-responsive transcripts p21, PUMA, gadd45, and Mdm2 and recruitment of p53 to chromatin. Nutlin-3 also reduces androgen receptor levels, resulting in altered receptor recruitment to chromatin. Our study demonstrates that small molecule MDM2 antagonists might be useful in the treatment of human prostate cancers that retain functional p53 and androgen receptor signaling. Copyright 2007 Wiley-Liss, Inc.

Retroperitoneal dedifferentiated liposarcoma lacking MDM2 amplification in a patient with a germ line CHEK2 mutation.

PubMed

Sadri, Navid; Surrey, Lea F; Fraker, Douglas L; Zhang, Paul J

2014-04-01

Germ line mutations in genes that encode proteins involved in the DNA damage response predispose patients to a variety of tumors. Checkpoint kinase 2, encoded by the CHEK2 gene, is important in transducing the DNA damage response. Germ line CHEK2 mutations are seen in a subset of patients with a familial breast cancer and sarcoma phenotype. We report a case of retroperitoneal dedifferentiated liposarcoma in a 61-year-old female with germ line CHEK2 mutation. MDM2 gene amplification normally present and used to aid in the diagnosis of retroperitoneal dedifferentiated liposarcoma was absent in this case. Lack of MDM2 overexpression has similarly been reported in liposarcomas arising in patients with germ line TP53 mutations. We propose this case may highlight a nonamplified MDM2 phenotype in well- and dedifferentiated liposarcomas arising in patients with germ line mutations of genes involved in p53-associated DNA damage response pathways.

Discovery of 4-((3′R,4′S,5′R)-6″-Chloro-4′-(3-chloro-2-fluorophenyl)-1′-ethyl-2″-oxodispiro[cyclohexane-1,2′-pyrrolidine-3′,3″-indoline]-5′-carboxamido)bicyclo[2.2.2]octane-1-carboxylic Acid (AA-115/APG-115): A Potent and Orally Active Murine Double Minute 2 (MDM2) Inhibitor in Clinical Development

PubMed Central

2017-01-01

We previously reported the design of spirooxindoles with two identical substituents at the carbon-2 of the pyrrolidine core as potent MDM2 inhibitors. In this paper we describe an extensive structure–activity relationship study of this class of MDM2 inhibitors, which led to the discovery of 60 (AA-115/APG-115). Compound 60 has a very high affinity to MDM2 (Ki < 1 nM), potent cellular activity, and an excellent oral pharmacokinetic profile. Compound 60 is capable of achieving complete and long-lasting tumor regression in vivo and is currently in phase I clinical trials for cancer treatment. PMID:28339198

A retrospective comparison of false negative skin test rates in penicillin allergy, using pencilloyl-poly-lysine and minor determinants or Penicillin G, followed by open challenge.

PubMed

Rosenfield, Lana; Kalicinsky, Chrystyna; Warrington, Richard

2015-01-01

A history of penicillin allergy in patients is common, but only 10-15 % are truly allergic. While the gold standard for diagnosing penicillin allergy is challenge, it is not recommended that this be done without first carrying out diagnostic skin testing. This is carried out with the major determinant benzylpenicilloyl (PPL) and the minor determinant mixture (MDM), consisting of penilloate, penicilloate and Penicillin G. However, since availability of the MDM is limited, Penicillin G alone has been used. A retrospective chart review was carried out on patients tested for penicillin allergy in the Clinical Immunology and Allergy Clinic at the Health Sciences Centre, Winnipeg, Canada between 2005 and 2013. A total of 521 patients charts were reviewed, of whom 240 had skin testing, ImmunoCap(®) for IgE to Penicillin G and V and had oral challenges with penicillin, amoxicillin or cloxacillin. 17/240 (7.5 %) were skin test positive, 8 to PPL, 4 to MDM and 5 to Penicillin G. One was also positive on ImmunoCap(®) testing. Three patients had negative skin tests but weakly positive ImmunoCap(®). 222 patients with negative skin tests and serological tests were challenged. Of these, 12 patients reacted to challenge. Three of the challenges were equivocal. Of the nine patients with definite positive challenges, three were tested with Penicillin G and six with MDM. Therefore the false negative rates for testing were 2.3 % with PPL and Penicillin G and 6.97 % for PPL and MDM. The difference was not significant (p = 0.0856). In this group of patients with a history of penicillin allergy tested with the major determinant of benzyl penicillin and either MDM or Penicillin G, there was no difference in the rate of false negative testing, based on oral penicillin challenges. Therefore, Penicillin G can be safely used as an alternative to MDM in diagnosing penicillin allergy.

Immunohistochemical status of p53, MDM2, bcl2, bax, and ER in invasive ductal breast carcinoma in Tunisian patients.

PubMed

Baccouche, Sami; Daoud, Jamel; Frikha, Mounir; Mokdad-Gargouri, Raja; Gargouri, Ali; Jlidi, Rachid

2003-12-01

TP53 gene alterations have been associated with sporadic breast cancer. To assess the role of p53 in invasive ductal carcinoma (IDC) of the breast among Tunisian patients, p53 protein status was studied by immuno-histochemical analysis. The p53 protein was expressed in 41 of 70 (58%) tumors. Study of the status of its target gene expression showed that MDM2 was overexpressed in 43 tumors (61%), bcl2 in 29 (41%), and bax in only 9 (12%). Estrogen receptor (ER) was detected in 38 tumor tissues (54%). The accumulated p53 was significantly associated with MDM2-positive, bcl2-negative, and ER-negative tumors (P = 0.024, P = 0.000027, and P = 0.000008, respectively), whereas with bax the correlaton was not significant. Bcl2 immunostaining displayed a positive correlation with ER (P = 0.001). A significantly higher fraction of p53-positive cells was observed in ER-negative SBRII-SBRIII tumors than in ER-positive SBRI-SBRII tumors (P = 0.000066). bcl2-positive tumors were significantly correlated with ER-positive/SBRI-SBRII tumors (P = 0.007), but negatively correlated with p53/bax (P = 0000004). MDM2 immunostaining displayed the same phenotype as p53 in the correlation with bcl2 and ER (P = 0.003), strengthened by significant associations between MDM2-positive/p53-positive and bcl2-negative or ER-negative, respectively (P = 0.00005 and P = 0.000001, respectively). MDM2-positive cells were significantly correlated with the p53-positive/bax-negative phenotype (P = 0.04). These results suggest that p53 accumulated in these tumor tissues is associated with bad prognostic markers (ER-negative, SBRIII) of IDC. MDM2 overexpression might be responsible for the accumulated p53 value in IDC. Regulation of the apoptotic process is involved in IDC; bcl2 is associated with a good prognostic marker (ER-positive and SBRI-II), whereas the regulation of bax is complex and does not necessarily correlate with the overexpression of p53.

Prognostic relevance of Fédération Nationale des Centres de Lutte Contre le Cancer grade and MDM2 amplification levels in dedifferentiated liposarcoma: a study of 50 cases.

PubMed

Jour, George; Gullet, Ashley; Liu, Mingdong; Hoch, Benjamin L

2015-01-01

Dedifferentiated liposarcoma represents a form of liposarcoma composed of a non-lipogenic sarcoma associated with well-differentiated liposarcoma. The prognostic significance of histological grading of the dedifferentiated component remains to be elucidated due to vague grading criteria employed in previous studies. Molecular markers of tumor behavior, including amplification levels of murine double minute-2 (MDM2) and cyclin-dependent kinase-4 (CDK4) genes, have been explored in a limited number of cases. Here we investigate whether 'Fédération Nationale des Centres de Lutte Contre le Cancer' (FNCLCC) grade and MDM2 gene amplification levels have prognostic value in dedifferentiated liposarcoma in terms of local recurrence and disease-specific survival. Fifty cases were retrieved, reviewed and FNCLCC grade was scored for the dedifferentiated component. Testing for MDM2 gene amplification was performed by fluorescence in situ hybridization. Amplification was categorized as high level (≥20 copies) and as low level (<20 copies). Follow-up data was obtained through chart review. Log-rank test and Cox proportional hazard models were used to determine the effect of grade and level of MDM2 amplification on outcomes. Our series includes 50 patients (male n=28, female n=22) with an average age of 63 years (range, 28-88) and a median follow-up of 28 months (range, 2-120). Tumors were graded as grade 1 (6%), grade 2 (58%), and grade 3 (36%). When adjusted for age, sex, site, tumor size, and margin status, grade 3 patients had a higher recurrence rate than grades 1 and 2 (HR=2.07, 95% CI: 1.24, 7.62; P=0.015). Patients with high-level MDM2 amplification had higher recurrence rate on univariate analysis (P=0.028), but not on multivariate analysis (HR=1.69, 95% CI: 0.73, 3.94; P=0.221). FNCLCC grade 3 dedifferentiation confers a worse prognosis in dedifferentiated liposarcoma in terms of local recurrence. MDM2 amplification level remains a useful diagnostic tool in dedifferentiated liposarcoma, but has no prognostic value in terms of local recurrence.

RECENT REFERENCES: JULY 1, 2005 TO SEPTEMBER 30, 2005

DOE Office of Scientific and Technical Information (OSTI.GOV)

WINCHELL, D.F.

2005-09-30

This document lists experimental references added to Nuclear Science References (NSR) during the period July 1, 2005 to September 30, 2005. The first section lists keynumbers and keywords sorted by mass and nuclide. The second section lists all references, ordered by keynumber.

RECENT REFERENCES: OCTOBER 1, 2005 TO DECEMBER 31, 2005

DOE Office of Scientific and Technical Information (OSTI.GOV)

WINCHELL, D.F.

2005-12-31

This document lists experimental references added to Nuclear Science References (NSR) during the period October 1, 2005 to December 31, 2005. The first section lists keynumbers and keywords sorted by mass and nuclide. The second section lists all references, ordered by keynumber.

Non-linear feedback control of the p53 protein-mdm2 inhibitor system using the derivative-free non-linear Kalman filter.

PubMed

Rigatos, Gerasimos G

2016-06-01

It is proven that the model of the p53-mdm2 protein synthesis loop is a differentially flat one and using a diffeomorphism (change of state variables) that is proposed by differential flatness theory it is shown that the protein synthesis model can be transformed into the canonical (Brunovsky) form. This enables the design of a feedback control law that maintains the concentration of the p53 protein at the desirable levels. To estimate the non-measurable elements of the state vector describing the p53-mdm2 system dynamics, the derivative-free non-linear Kalman filter is used. Moreover, to compensate for modelling uncertainties and external disturbances that affect the p53-mdm2 system, the derivative-free non-linear Kalman filter is re-designed as a disturbance observer. The derivative-free non-linear Kalman filter consists of the Kalman filter recursion applied on the linearised equivalent of the protein synthesis model together with an inverse transformation based on differential flatness theory that enables to retrieve estimates for the state variables of the initial non-linear model. The proposed non-linear feedback control and perturbations compensation method for the p53-mdm2 system can result in more efficient chemotherapy schemes where the infusion of medication will be better administered.

Significant Association of the MDM2 T309G Polymorphism with Breast Cancer Risk in a Turkish Population

PubMed

Yilmaz, Meral; Tas, Ayca; Donmez, Gonca; Kacan, Turgut; Silig, Yavuz

2018-04-27

Background: Breast cancer is a leading cause of death in women worldwide. Genetic polymorphisms have been reported to be important etiological factors. Murine double minute 2 (MDM2) T309G interacts with p53 and mutations in p53 are present in approximately 50% of all cancers. However, it has been reported that effect of the polymorphism on breast cancer risk may vary in different populations. Here, we therefore investigated whether there is an association between MDM2 T309G (rs2279744) polymorphism and breast cancer in a Turkish population. Materials and Methods: We analysed 110 patients with breast cancer and 138 matched? controls. For genotyping, polymerase chain reaction and restriction length fragment polymorphism methods were used. Results: A significant difference was observed between case and control groups with regard to the distribution of the MDM2 T309G polymorphism (p<0.05). There was a significantly higher frequency of the TT genotype in the control group (p=0.028; OR, 2.42; 95% CI, 1.09-5.37). However, we did not find any relationships among tumor grade and metastasis status and this polymorphism. Conclusion: This study indicates that the MDM2 T309G polymorphism GG genotype and the TG+GG combination may be risk factors for breast cancer in our Turkish population. Creative Commons Attribution License

Study of MDM2 and SUMO-1 expression in actinic cheilitis and lip cancer.

PubMed

Oliveira Alves, Mônica Ghislaine; da Mota Delgado, Adriana; Balducci, Ivan; Carvalho, Yasmin Rodarte; Cavalcante, Ana Sueli Rodrigues; Almeida, Janete Dias

2014-11-01

Actinic cheilitis exhibits a potential of malignant transformation in 10-20 % of cases. The objective of this study was to compare the expression of MDM2 and SUMO-1 proteins between actinic cheilitis (AC) and squamous cell carcinoma (SCC) of the lip. The sample consisted of lower lip mucosa specimens obtained from cases with a clinical and histopathological diagnosis of AC (n = 26) and SCC (n = 25) and specimens of labial semi-mucosa (n = 15) without clinical alterations or inflammation. The tissue samples were stained with hematoxylin-eosin and anti-MDM2 and anti-SUMO-1 antibodies. Data were analyzed by the Kruskal-Wallis and Dunn's tests (5 %). The median expression of MDM2 (kW = 36.8565; df = 3-1 = 2; p = 0.0001) and SUMO-1 (kW = 32.7080; df = 3-1 = 2; p = 0.0001) was similar in cases of AC and SCC of the lip, but differed significantly from that observed for normal labial semi-mucosa. Despite the limitations of the present study, immunohistochemistry demonstrated the overexpression of important proteins (MDM2 and SUMO-1) related to regulatory mechanisms of apoptosis in AC and SCC of the lip, but further studies are needed.

The cis conformation of proline leads to weaker binding of a p53 peptide to MDM2 compared to trans.

PubMed

Zhan, Yingqian Ada; Ytreberg, F Marty

2015-06-01

The cis and trans conformations of the Xaa-Pro (Xaa: any amino acid) peptide bond are thermodynamically stable while other peptide bonds strongly prefer trans. The effect of proline cis-trans isomerization on protein binding has not been thoroughly investigated. In this study, computer simulations were used to calculate the absolute binding affinity for a p53 peptide (residues 17-29) to MDM2 for both cis and trans isomers of the p53 proline in position 27. Results show that the cis isomer of p53(17-29) binds more weakly to MDM2 than the trans isomer, and that this is primarily due to the difference in the free energy cost associated with the loss of conformational entropy of p53(17-29) when it binds to MDM2. The population of cis p53(17-29) was estimated to be 0.8% of the total population in the bound state. The stronger binding of trans p53(17-29) to MDM2 compared to cis may leave a minimal level of p53 available to respond to cellular stress. This study demonstrates that it is feasible to estimate the absolute binding affinity for an intrinsically disordered protein fragment binding to an ordered protein that are in good agreement with experimental results. Copyright © 2015 Elsevier Inc. All rights reserved.

Cone arrestin binding to JNK3 and Mdm2: conformational preference and localization of interaction sites

PubMed Central

Song, Xiufeng; Gurevich, Eugenia V.; Gurevich, Vsevolod V.

2008-01-01

Arrestins are multi-functional regulators of G protein-coupled receptors. Receptor-bound arrestins interact with >30 remarkably diverse proteins and redirect the signaling to G protein-independent pathways. The functions of free arrestins are poorly understood, and the interaction sites of the non-receptor arrestin partners are largely unknown. In this study, we show that cone arrestin, the least studied member of the family, binds c-Jun N-terminal kinase (JNK3) and Mdm2 and regulates their subcellular distribution. Using arrestin mutants with increased or reduced structural flexibility, we demonstrate that arrestin in all conformations binds JNK3 comparably, whereas Mdm2 preferentially binds cone arrestin ‘frozen’ in the basal state. To localize the interaction sites, we expressed separate N- and C-domains of cone and rod arrestins and found that individual domains bind JNK3 and remove it from the nucleus as efficiently as full-length proteins. Thus, the arrestin binding site for JNK3 includes elements in both domains with the affinity of partial sites on individual domains sufficient for JNK3 relocalization. N-domain of rod arrestin binds Mdm2, which localizes its main interaction site to this region. Comparable binding of JNK3 and Mdm2 to four arrestin subtypes allowed us to identify conserved residues likely involved in these interactions. PMID:17680991

Probing the origin of structural stability of single and double stapled p53 peptide analogs bound to MDM2.

PubMed

Guo, Zuojun; Streu, Kristina; Krilov, Goran; Mohanty, Udayan

2014-06-01

The stabilization of secondary structure is believed to play an important role in the peptide-protein binding interaction. In this study, the α-helical conformation and structural stability of single and double stapled all-hydrocarbon cross-linked p53 peptides when bound and unbound to MDM2 are investigated. We determined the effects of the peptide sequence, the stereochemistry of the cross-linker, the conformation of the double bond in the alkene bridge, and the length of the bridge, to the relative stability of the α-helix structure. The binding affinity calculations by WaterMap provided over one hundred hydration sites in the MDM2 binding pocket where water density is greater than twice that of the bulk, and the relative value of free energy released by displacing these hydration sites. In agreement with the experimental data, potentials of mean force obtained by weighted histogram analysis methods indicated the order of peptides from lowest to highest binding affinity. Our study provides a comprehensive rationalization of the relationship between peptide stapling strategy, the secondary structural stability, and the binding affinity of p53/MDM2 complex. We hope our efforts can help to further the development of a new generation p53/MDM2 inhibitors that can reactivate the function of p53 as tumor suppressor gene. © 2014 John Wiley & Sons A/S.

A computational analysis of the binding model of MDM2 with inhibitors

NASA Astrophysics Data System (ADS)

Hu, Guodong; Wang, Dunyou; Liu, Xinguo; Zhang, Qinggang

2010-08-01

It is a new and promising strategy for anticancer drug design to block the MDM2-p53 interaction using a non-peptide small-molecule inhibitor. We carry out molecular dynamics simulations to study the binding of a set of six non-peptide small-molecule inhibitors with the MDM2. The relative binding free energies calculated using molecular mechanics Poisson-Boltzmann surface area method produce a good correlation with experimentally determined results. The study shows that the van der Waals energies are the largest component of the binding free energy for each complex, which indicates that the affinities of these inhibitors for MDM2 are dominated by shape complementarity. The A-ligands and the B-ligands are the same except for the conformation of 2,2-dimethylbutane group. The quantum mechanics and the binding free energies calculation also show the B-ligands are the more possible conformation of ligands. Detailed binding free energies between inhibitors and individual protein residues are calculated to provide insights into the inhibitor-protein binding model through interpretation of the structural and energetic results from the simulations. The study shows that G1, G2 and G3 group mimic the Phe19, Trp23 and Leu26 residues in p53 and their interactions with MDM2, but the binding model of G4 group differs from the original design strategy to mimic Leu22 residue in p53.

Burbank works on the EPIC in the Node 2

NASA Image and Video Library

2012-02-28

ISS030-E-114433 (29 Feb. 2012) --- In the International Space Station?s Destiny laboratory, NASA astronaut Dan Burbank, Expedition 30 commander, upgrades Multiplexer/Demultiplexer (MDM) computers and Portable Computer System (PCS) laptops and installs the Enhanced Processor & Integrated Communications (EPIC) hardware in the Payload 1 (PL-1) MDM.

Spare EXT MDM Preparation

NASA Image and Video Library

2014-04-18

ISS039-E-013244 (18 April 2014) --- NASA astronaut Rick Mastracchio, Expeditionn 39 flight engineer, replaces the Enhanced Input/Output Control Unit Circuit Card of the spare External Multiplexer/Demultiplexer (MDM), in preparation for an upcoming spacewalk. He will be joined by fellow NASA astronaut and Flight Engineer Steve Swanson on the spacewalk.

DOE Office of Scientific and Technical Information (OSTI.GOV)

WINCHELL, D.F.

This document lists experimental references added to Nuclear Science References (NSR) during the period January 1, 2005 to December 31, 2005. The first section lists keynumbers and keywords sorted by mass and nuclide. The second section lists all references, ordered by keynumber.

DOE Office of Scientific and Technical Information (OSTI.GOV)

WINCHELL, D.F.

This document lists experimental references added to Nuclear Science References (NSR) during the period April 1, 2005 to June 30, 2005. The first section lists keynumbers and keywords sorted by mass and nuclide. The second section lists all references, ordered by keynumber.

Two-mode division multiplexing in a silicon-on-insulator ring resonator.

PubMed

Dorin, Bryce A; Ye, Winnie N

2014-02-24

Mode-division multiplexing (MDM) is an emerging multiple-input multiple-output method, utilizing multimode waveguides to increase channel numbers. In the past, silicon-on-insulator (SOI) devices have been primarily focused on single-mode waveguides. We present the design and fabrication of a two-mode SOI ring resonator for MDM systems. By optimizing the device parameters, we have ensured that each mode is treated equally within the ring. Using adiabatic Bezier curves in the ring bends, our ring demonstrated a signal-to-crosstalk ratio above 18 dB for both modes at the through and drop ports. We conclude that the ring resonator has the potential for filtering and switching for MDM systems on SOI.

Fast Optical Photometry of V404 Cyg at the MDM Observatory

NASA Astrophysics Data System (ADS)

Terndrup, D.; Wagner, R. M.; Starrfield, S.

2015-06-01

We obtained continuous fast differential optical photometry of V404 Cyg with the 1.3 m McGraw-Hill Telescope of the MDM Observatory on Kitt Peak on the nights of 2015 June 19.220-19.474, 20.194-20.472, 21.199-21.460, and 22.188-22.421 UT.

The Impact of a Common MDM2 SNP on the Sensitivity of Breast Cancer to Treatment

DTIC Science & Technology

2011-06-01

Kirchhoff T, Alexe G, Bond EE, Robins H, Bartel F, Taubert H, Wuerl P, Hait W, Toppmeyer D, Offit K, and Levine A. MDM2 SNP309 accelerates tumor...the Western blot analysis corresponding to the quantification in the upper graphs . 29 Figure 5. Effect of

Numerical simulation studies of nano-scale surface plasmon components: waveguides, splitters, and filters

NASA Astrophysics Data System (ADS)

Lin, Xian-Shi; Huang, Xu-Guang

2008-12-01

In this paper, we theoretically and numerically demonstrate a two-dimensional Metal-Dielectric-Metal (MDM) waveguide based on finite-difference time-domain simulation of the propagation characteristics of surface plasmon polaritons (SPPs). For practical applications, we propose a plasmonic Y-branch waveguide based on MDM structure for high integration. The simulation results show that the Y-branch waveguide proposed here makes optical splitter with large branching angle (~180 degree) come true. We also introduce a finite array of periodic tooth structure on one surface of the MDM waveguide which is in a similar way as FBGs or Bragg reflectors, potentially as filters for WDM applications. Our results show that the novel structure not only can realize filtering function of wavelength with a high transmittance over 92%, but also with an ultra-compact size in the length of a few hundred nanometers, in comparison with other grating-like SPPs filters. The MDM waveguide splitters and filters could be utilized to achieve ultra-compact photonic filtering devices for high integration in SPPs-based flat metallic surfaces.

MICOS and phospholipid transfer by Ups2-Mdm35 organize membrane lipid synthesis in mitochondria.

PubMed

Aaltonen, Mari J; Friedman, Jonathan R; Osman, Christof; Salin, Bénédicte; di Rago, Jean-Paul; Nunnari, Jodi; Langer, Thomas; Tatsuta, Takashi

2016-06-06

Mitochondria exert critical functions in cellular lipid metabolism and promote the synthesis of major constituents of cellular membranes, such as phosphatidylethanolamine (PE) and phosphatidylcholine. Here, we demonstrate that the phosphatidylserine decarboxylase Psd1, located in the inner mitochondrial membrane, promotes mitochondrial PE synthesis via two pathways. First, Ups2-Mdm35 complexes (SLMO2-TRIAP1 in humans) serve as phosphatidylserine (PS)-specific lipid transfer proteins in the mitochondrial intermembrane space, allowing formation of PE by Psd1 in the inner membrane. Second, Psd1 decarboxylates PS in the outer membrane in trans, independently of PS transfer by Ups2-Mdm35. This latter pathway requires close apposition between both mitochondrial membranes and the mitochondrial contact site and cristae organizing system (MICOS). In MICOS-deficient cells, limiting PS transfer by Ups2-Mdm35 and reducing mitochondrial PE accumulation preserves mitochondrial respiration and cristae formation. These results link mitochondrial PE metabolism to MICOS, combining functions in protein and lipid homeostasis to preserve mitochondrial structure and function. © 2016 Aaltonen et al.

Small-molecule MDM2 antagonists attenuate the senescence-associated secretory phenotype.

PubMed

Wiley, Christopher D; Schaum, Nicholas; Alimirah, Fatouma; Lopez-Dominguez, Jose Alberto; Orjalo, Arturo V; Scott, Gary; Desprez, Pierre-Yves; Benz, Christopher; Davalos, Albert R; Campisi, Judith

2018-02-05

Processes that have been linked to aging and cancer include an inflammatory milieu driven by senescent cells. Senescent cells lose the ability to divide, essentially irreversibly, and secrete numerous proteases, cytokines and growth factors, termed the senescence-associated secretory phenotype (SASP). Senescent cells that lack p53 tumor suppressor function show an exaggerated SASP, suggesting the SASP is negatively controlled by p53. Here, we show that increased p53 activity caused by small molecule inhibitors of MDM2, which promotes p53 degradation, reduces inflammatory cytokine production by senescent cells. Upon treatment with the MDM2 inhibitors nutlin-3a or MI-63, human cells acquired a senescence-like growth arrest, but the arrest was reversible. Importantly, the inhibitors reduced expression of the signature SASP factors IL-6 and IL-1α by cells made senescent by genotoxic stimuli, and suppressed the ability of senescent fibroblasts to stimulate breast cancer cell aggressiveness. Our findings suggest that MDM2 inhibitors could reduce cancer progression in part by reducing the pro-inflammatory environment created by senescent cells.

Combined ALK and MDM2 inhibition increases antitumor activity and overcomes resistance in human ALK mutant neuroblastoma cell lines and xenograft models

PubMed Central

Wang, Hui Qin; Halilovic, Ensar; Li, Xiaoyan; Liang, Jinsheng; Cao, Yichen; Rakiec, Daniel P; Ruddy, David A; Jeay, Sebastien; Wuerthner, Jens U; Timple, Noelito; Kasibhatla, Shailaja; Li, Nanxin; Williams, Juliet A; Sellers, William R; Huang, Alan; Li, Fang

2017-01-01

The efficacy of ALK inhibitors in patients with ALK-mutant neuroblastoma is limited, highlighting the need to improve their effectiveness in these patients. To this end, we sought to develop a combination strategy to enhance the antitumor activity of ALK inhibitor monotherapy in human neuroblastoma cell lines and xenograft models expressing activated ALK. Herein, we report that combined inhibition of ALK and MDM2 induced a complementary set of anti-proliferative and pro-apoptotic proteins. Consequently, this combination treatment synergistically inhibited proliferation of TP53 wild-type neuroblastoma cells harboring ALK amplification or mutations in vitro, and resulted in complete and durable responses in neuroblastoma xenografts derived from these cells. We further demonstrate that concurrent inhibition of MDM2 and ALK was able to overcome ceritinib resistance conferred by MYCN upregulation in vitro and in vivo. Together, combined inhibition of ALK and MDM2 may provide an effective treatment for TP53 wild-type neuroblastoma with ALK aberrations. DOI: http://dx.doi.org/10.7554/eLife.17137.001 PMID:28425916

CRISPR-Cas9-based target validation for p53-reactivating model compounds

PubMed Central

Wanzel, Michael; Vischedyk, Jonas B; Gittler, Miriam P; Gremke, Niklas; Seiz, Julia R; Hefter, Mirjam; Noack, Magdalena; Savai, Rajkumar; Mernberger, Marco; Charles, Joël P; Schneikert, Jean; Bretz, Anne Catherine; Nist, Andrea; Stiewe, Thorsten

2015-01-01

Inactivation of the p53 tumor suppressor by Mdm2 is one of the most frequent events in cancer, so compounds targeting the p53-Mdm2 interaction are promising for cancer therapy. Mechanisms conferring resistance to p53-reactivating compounds are largely unknown. Here we show using CRISPR-Cas9–based target validation in lung and colorectal cancer that the activity of nutlin, which blocks the p53-binding pocket of Mdm2, strictly depends on functional p53. In contrast, sensitivity to the drug RITA, which binds the Mdm2-interacting N terminus of p53, correlates with induction of DNA damage. Cells with primary or acquired RITA resistance display cross-resistance to DNA crosslinking compounds such as cisplatin and show increased DNA cross-link repair. Inhibition of FancD2 by RNA interference or pharmacological mTOR inhibitors restores RITA sensitivity. The therapeutic response to p53-reactivating compounds is therefore limited by compound-specific resistance mechanisms that can be resolved by CRISPR-Cas9-based target validation and should be considered when allocating patients to p53-reactivating treatments. PMID:26595461

Population distribution and ancestry of the cancer protective MDM2 SNP285 (rs117039649).

PubMed

Knappskog, Stian; Gansmo, Liv B; Dibirova, Khadizha; Metspalu, Andres; Cybulski, Cezary; Peterlongo, Paolo; Aaltonen, Lauri; Vatten, Lars; Romundstad, Pål; Hveem, Kristian; Devilee, Peter; Evans, Gareth D; Lin, Dongxin; Van Camp, Guy; Manolopoulos, Vangelis G; Osorio, Ana; Milani, Lili; Ozcelik, Tayfun; Zalloua, Pierre; Mouzaya, Francis; Bliznetz, Elena; Balanovska, Elena; Pocheshkova, Elvira; Kučinskas, Vaidutis; Atramentova, Lubov; Nymadawa, Pagbajabyn; Titov, Konstantin; Lavryashina, Maria; Yusupov, Yuldash; Bogdanova, Natalia; Koshel, Sergey; Zamora, Jorge; Wedge, David C; Charlesworth, Deborah; Dörk, Thilo; Balanovsky, Oleg; Lønning, Per E

2014-09-30

The MDM2 promoter SNP285C is located on the SNP309G allele. While SNP309G enhances Sp1 transcription factor binding and MDM2 transcription, SNP285C antagonizes Sp1 binding and reduces the risk of breast-, ovary- and endometrial cancer. Assessing SNP285 and 309 genotypes across 25 different ethnic populations (>10.000 individuals), the incidence of SNP285C was 6-8% across European populations except for Finns (1.2%) and Saami (0.3%). The incidence decreased towards the Middle-East and Eastern Russia, and SNP285C was absent among Han Chinese, Mongolians and African Americans. Interhaplotype variation analyses estimated SNP285C to have originated about 14,700 years ago (95% CI: 8,300 - 33,300). Both this estimate and the geographical distribution suggest SNP285C to have arisen after the separation between Caucasians and modern day East Asians (17,000 - 40,000 years ago). We observed a strong inverse correlation (r = -0.805; p < 0.001) between the percentage of SNP309G alleles harboring SNP285C and the MAF for SNP309G itself across different populations suggesting selection and environmental adaptation with respect to MDM2 expression in recent human evolution. In conclusion, we found SNP285C to be a pan-Caucasian variant. Ethnic variation regarding distribution of SNP285C needs to be taken into account when assessing the impact of MDM2 SNPs on cancer risk.

Feedback modulation of neural network synchrony and seizure susceptibility by Mdm2-p53-Nedd4-2 signaling.

PubMed

Jewett, Kathryn A; Christian, Catherine A; Bacos, Jonathan T; Lee, Kwan Young; Zhu, Jiuhe; Tsai, Nien-Pei

2016-03-22

Neural network synchrony is a critical factor in regulating information transmission through the nervous system. Improperly regulated neural network synchrony is implicated in pathophysiological conditions such as epilepsy. Despite the awareness of its importance, the molecular signaling underlying the regulation of neural network synchrony, especially after stimulation, remains largely unknown. In this study, we show that elevation of neuronal activity by the GABA(A) receptor antagonist, Picrotoxin, increases neural network synchrony in primary mouse cortical neuron cultures. The elevation of neuronal activity triggers Mdm2-dependent degradation of the tumor suppressor p53. We show here that blocking the degradation of p53 further enhances Picrotoxin-induced neural network synchrony, while promoting the inhibition of p53 with a p53 inhibitor reduces Picrotoxin-induced neural network synchrony. These data suggest that Mdm2-p53 signaling mediates a feedback mechanism to fine-tune neural network synchrony after activity stimulation. Furthermore, genetically reducing the expression of a direct target gene of p53, Nedd4-2, elevates neural network synchrony basally and occludes the effect of Picrotoxin. Finally, using a kainic acid-induced seizure model in mice, we show that alterations of Mdm2-p53-Nedd4-2 signaling affect seizure susceptibility. Together, our findings elucidate a critical role of Mdm2-p53-Nedd4-2 signaling underlying the regulation of neural network synchrony and seizure susceptibility and reveal potential therapeutic targets for hyperexcitability-associated neurological disorders.

Direct observations of conformational distributions of intrinsically disordered p53 peptides using UV Raman and explicit solvent simulations

PubMed Central

Xiong, Kan; Zwier, Matthew C.; Myshakina, Nataliya S.; Burger, Virginia M.; Asher, Sanford A.; Chong, Lillian T.

2011-01-01

We report the first experimental measurements of Ramachandran Ψ-angle distributions for intrinsically disordered peptides: the N-terminal peptide fragment of tumor suppressor p53 and its P27 mutant form. To provide atomically detailed views of the conformational distributions, we performed classical, explicit-solvent molecular dynamics simulations on the microsecond timescale. Upon binding its partner protein, MDM2, wild-type p53 peptide adopts an α-helical conformation. Mutation of Pro27 to serine results in the highest affinity yet observed for MDM2-binding of the p53 peptide. Both UV resonance Raman spectroscopy (UVRR) and simulations reveal that the P27S mutation decreases the extent of PPII helical content and increases the probability for conformations that are similar to the α-helical MDM2-bound conformation. In addition, UVRR measurements were performed on peptides that were isotopically labeled at the Leu26 residue preceding the Pro27 in order to determine the conformational distributions of Leu26 in the wild-type and mutant peptides. The UVRR and simulation results are in quantitative agreement in terms of the change in the population of non-PPII conformations involving Leu26 upon mutation of Pro27 to serine. Finally, our simulations reveal that the MDM2-bound conformation of the peptide is significantly populated in both the wild-type and mutant isolated peptide ensembles in their unbound states, suggesting that MDM2 binding of the p53 peptides may involve conformational selection. PMID:21528875

Genome-wide Mechanosensitive MicroRNA (MechanomiR) Screen Uncovers Dysregulation of Their Regulatory Networks in the mdm Mouse Model of Muscular Dystrophy*

PubMed Central

Mohamed, Junaith S.; Hajira, Ameena; Lopez, Michael A.; Boriek, Aladin M.

2015-01-01

Muscular dystrophies (MDs) are a heterogeneous group of genetic and neuromuscular disorders, which result in severe loss of motor ability and skeletal muscle mass and function. Aberrant mechanotransduction and dysregulated-microRNA pathways are often associated with the progression of MD. Here, we hypothesized that dysregulation of mechanosensitive microRNAs (mechanomiRs) in dystrophic skeletal muscle plays a major role in the progression of MD. To test our hypothesis, we performed a genome-wide expression profile of anisotropically regulated mechanomiRs and bioinformatically analyzed their target gene networks. We assessed their functional roles in the advancement of MD using diaphragm muscles from mdm (MD with myositis) mice, an animal model of human tibial MD (titinopathy), and their wild-type littermates. We were able to show that ex vivo anisotropic mechanical stretch significantly alters the miRNA expression profile in diaphragm muscles from WT and mdm mice; as a result, some of the genes associated with MDs are dysregulated in mdm mice due to differential regulation of a distinct set of mechanomiRs. Interestingly, we found a contrasting expression pattern of the highly expressed let-7 family mechanomiRs, let-7e-5p and miR-98–5p, and their target genes associated with the extracellular matrix and TGF-β pathways, respectively, between WT and mdm mice. Gain- and loss-of-function analysis of let-7e-5p in myocytes isolated from the diaphragms of WT and mdm mice confirmed Col1a1, Col1a2, Col3a1, Col24a1, Col27a1, Itga1, Itga4, Scd1, and Thbs1 as target genes of let-7e-5p. Furthermore, we found that miR-98 negatively regulates myoblast differentiation. Our study therefore introduces additional biological players in the regulation of skeletal muscle structure and myogenesis that may contribute to unexplained disorders of MD. PMID:26272747

Combination therapy in a xenograft model of glioblastoma: enhancement of the antitumor activity of temozolomide by an MDM2 antagonist.

PubMed

Wang, Haiyan; Cai, Shanbao; Bailey, Barbara J; Reza Saadatzadeh, M; Ding, Jixin; Tonsing-Carter, Eva; Georgiadis, Taxiarchis M; Zachary Gunter, T; Long, Eric C; Minto, Robert E; Gordon, Kevin R; Sen, Stephanie E; Cai, Wenjing; Eitel, Jacob A; Waning, David L; Bringman, Lauren R; Wells, Clark D; Murray, Mary E; Sarkaria, Jann N; Gelbert, Lawrence M; Jones, David R; Cohen-Gadol, Aaron A; Mayo, Lindsey D; Shannon, Harlan E; Pollok, Karen E

2017-02-01

OBJECTIVE Improvement in treatment outcome for patients with glioblastoma multiforme (GBM) requires a multifaceted approach due to dysregulation of numerous signaling pathways. The murine double minute 2 (MDM2) protein may fulfill this requirement because it is involved in the regulation of growth, survival, and invasion. The objective of this study was to investigate the impact of modulating MDM2 function in combination with front-line temozolomide (TMZ) therapy in GBM. METHODS The combination of TMZ with the MDM2 protein-protein interaction inhibitor nutlin3a was evaluated for effects on cell growth, p53 pathway activation, expression of DNA repair proteins, and invasive properties. In vivo efficacy was assessed in xenograft models of human GBM. RESULTS In combination, TMZ/nutlin3a was additive to synergistic in decreasing growth of wild-type p53 GBM cells. Pharmacodynamic studies demonstrated that inhibition of cell growth following exposure to TMZ/nutlin3a correlated with: 1) activation of the p53 pathway, 2) downregulation of DNA repair proteins, 3) persistence of DNA damage, and 4) decreased invasion. Pharmacokinetic studies indicated that nutlin3a was detected in human intracranial tumor xenografts. To assess therapeutic potential, efficacy studies were conducted in a xenograft model of intracranial GBM by using GBM cells derived from a recurrent wild-type p53 GBM that is highly TMZ resistant (GBM10). Three 5-day cycles of TMZ/nutlin3a resulted in a significant increase in the survival of mice with GBM10 intracranial tumors compared with single-agent therapy. CONCLUSIONS Modulation of MDM2/p53-associated signaling pathways is a novel approach for decreasing TMZ resistance in GBM. To the authors' knowledge, this is the first study in a humanized intracranial patient-derived xenograft model to demonstrate the efficacy of combining front-line TMZ therapy and an inhibitor of MDM2 protein-protein interactions.

Concordant p53 and mdm-2 protein expression in vulvar squamous cell carcinoma and adjacent lichen sclerosus.

PubMed

Carlson, J A; Amin, S; Malfetano, J; Tien, A T; Selkin, B; Hou, J; Goncharuk, V; Wilson, V L; Rohwedder, A; Ambros, R; Ross, J S

2001-06-01

To determine if carcinogenic events in vulvar skin precede the onset of morphologic atypia, the authors investigated for derangements in DNA content, cell proliferation, and cell death in vulvar carcinomas and surrounding skin in 140 samples of tumor and surrounding skin collected from 35 consecutive vulvectomy specimen for squamous cell carcinoma (SCC) or vulvar intraepithelial neoplasia (VIN) 3. Vulvar non-cancer excisions were used as controls. Investigations consisted of histologic classification and measurement of 9 variables--epidermal thickness (acanthosis and rete ridge length), immunolabeling index (LI) for 3 proteins (p53 protein, Ki-67, and mdm-2), pattern of p53 expression (dispersed vs. compact), DNA content index, and presence of aneuploidy by image analysis and apoptotic rate by Apotag labeling. Significant positive correlations were found for all nine variables studied versus increasing histologic severity in two proposed histologic stepwise models of vulvar carcinogenesis (lichen sclerosus (LS) and VIN 3 undifferentiated associated SCC groups). High p53 LI (>25) and the compact pattern of p53 expression (suspected oncoprotein) significantly correlated with LS and its associated vulvar samples compared with samples not associated with LS (P < or = 0.001). Furthermore, p53 LI, mdm-2 LI, and pattern of p53 expression were concordant between patient matched samples of LS and SCC. In addition, mdm-2 LI significantly correlated with dispersed pattern p53 LI suggesting a response to wild-type p53 protein accumulation. These findings support the hypothesis that neoplastic transformation occurs in sequential steps and compromises proteins involved in the cell cycle control. Concordance of p53 and mdm-2 protein expression in LS and adjacent SCC provides evidence that LS can act as a precursor lesion in the absence of morphologic atypia. Overexpression of mdm-2 with stabilization and inactivation of p53 protein may provide an alternate pathway for vulvar carcinogenesis.

Lung cancer pathogenesis associated with wood smoke exposure.

PubMed

Delgado, Javier; Martinez, Luis M; Sánchez, Therasa T; Ramirez, Alejandra; Iturria, Cecilia; González-Avila, Georgina

2005-07-01

Tobacco is considered the most important cause of lung cancer, but other factors could also be involved in its pathogenesis. The aim of the present work was to establish an association between wood smoke exposure and lung cancer pathogenesis, and to analyze the effects of wood smoke on p53 and murine double minute 2 (MDM2) protein expression. Blood samples were obtained from 62 lung cancer patients, 9 COPD patients, and 9 control subjects. Of the 62 lung cancer patients, 23 were tobacco smokers (lung cancer associated with tobacco [LCT] group), 24 were exposed to wood smoke (lung cancer associated with wood smoke [LCW] group), and 15 could not be included in these groups. Western blot assays were performed to identify the presence of p53, phospho-p53, and murine double minute 2 (MDM2) isoforms in plasma samples. Densitometric analysis was used to determine the intensity of p53, phospho-p53, and MDM2 bands. Approximately 38.7% of the lung cancer patients examined had an association with wood smoke exposure, most of them women living in rural areas. Adenocarcinoma was present in 46.7% of these patients. The p53 and phospho-p53 proteins were significantly increased in LCW samples (56,536.8 +/- 4,629 densitometry units [DU] and 58,244.8 +/- 7,492 DU, respectively [+/- SD]), in comparison with the other groups. The 57-kD MDM2 isoform plasma concentration was very high in LCW and LCT samples (75,696.4 +/- 11,979 DU and 78,551.7 +/- 11,548 DU, respectively). MDM2-p53 complexes were present in a high concentration in control and COPD subjects. This allows p53 degradation and explains the low concentrations of p53 found in these groups. MDM2-phospho-p53 complexes were observed in COPD but not in the other samples. This correlates with the low concentration of p53 observed in the COPD group (13,657 +/- 2,012 DU), and could explain the different clinic evolution of this smoker population in comparison with the LCT subjects. This study suggests that there is a possible association of lung cancer with wood smoke exposure. Likewise, our findings demonstrate that wood smoke could produce similar effects on p53, phospho-p53, and MDM2 protein expression as tobacco.

Preliminary characterization of an expanding flow of siloxane vapor MDM

NASA Astrophysics Data System (ADS)

Spinelli, A.; Cozzi, F.; Cammi, G.; Zocca, M.; Gaetani, P.; Dossena, V.; Guardone, A.

2017-03-01

The early experimental results on the characterization of expanding flows of siloxane vapor MDM (C8H24O2Si3, octamethyltrisiloxane) are presented. The measurements were performed on the Test Rig for Organic VApors (TROVA) at the CREA Laboratory of Politecnico di Milano. The TROVA test-rig was built in order to investigate the non-ideal compressible-fluid behavior of typical expanding flows occurring within organic Rankine cycles (ORC) turbine passages. The test rig implements a batch Rankine cycle where a planar converging-diverging nozzle replaces the turbine and represents a test section. Investigations related to both fields of non-ideal compressible-fluid dynamics fundamentals and turbomachinery are allowed. The nozzle can be operated with different working fluids and operating conditions aiming at measuring independently the pressure, the temperature and the velocity field and thus providing data to verify the thermo-fluid dynamic models adopted to predict the behavior of these flows. The limiting values of pressure and temperature are 50 bar and 400 °C respectively. The early measurements are performed along the nozzle axis, where an isentropic process is expected to occur. In particular, the results reported here refer to the nozzle operated in adapted conditions using the siloxane vapor MDM as working fluid in thermodynamic regions where mild to medium non-ideal compressible-fluid effects are present. Both total temperature and total pressure of the nozzle are measured upstream of the test section, while static pressure are measured along the nozzle axis. Schlieren visualizations are also carried out in order to complement the pressure measurement with information about the 2D density gradient field. The Laser Doppler Velocimetry technique is planned to be used in the future for velocity measurements. The measured flow field has also been interpreted by resorting to the quasi-one-dimensional theory and two dimensional CFD viscous calculation. In both cases state-of-the-art thermodynamic models were applied.

On p53 revival using system oriented drug dosage design.

PubMed

Haseeb, Muhammad; Azam, Shumaila; Bhatti, A I; Azam, Rizwan; Ullah, Mukhtar; Fazal, Sahar

2017-02-21

We propose a new paradigm in the drug design for the revival of the p53 pathway in cancer cells. It is shown that the current strategy of using small molecule based Mdm2 inhibitors is not enough to adequately revive p53 in cancerous cells, especially when it comes to the extracting pulsating behavior of p53. This fact has come to notice when a novel method for the drug dosage design is introduced using system oriented concepts. As a test case, small molecule drug Mdm2 repressor Nutlin 3a is considered. The proposed method determines the dose of Nutlin to revive p53 pathway functionality. For this purpose, PBK dynamics of Nutlin have also been integrated with p53 pathway model. The p53 pathway is the focus of researchers for the last thirty years for its pivotal role as a frontline cancer suppressant protein due to its effect on cell cycle checkpoints and cell apoptosis in response to a DNA strand break. That is the reason for finding p53 being absent in more than 50% of tumor cancers. Various drugs have been proposed to revive p53 in cancer cells. Small molecule based drugs are at the foremost and are the subject of advanced clinical trials. The dosage design of these drugs is an important issue. We use control systems concepts to develop the drug dosage so that the cancer cells can be treated in appropriate time. We investigate by using a computational model how p53 protein responds to drug Nutlin 3a, an agent that interferes with the MDM2-mediated p53 regulation. The proposed integrated model describes in some detail the regulation network of p53 including the negative feedback loop mediated by MDM2 and the positive feedback loop mediated by Mdm2 mRNA as well as the reversible represses of MDM2 caused by Nutlin. The reported PBK dynamics of Nutlin 3a are also incorporated to see the full effect. It has been reported that p53 response to stresses in two ways. Either it has a sustained (constant) p53 response, or there are oscillations in p53 concentration. The claimed dosage strategy achieves the p53 response in the first case. However, for the induction of oscillations, it is shown through bifurcation analysis that to achieve oscillating behavior of p53 inhibition of Mdm2 is not enough, rather antirepression of the p53-Mdm2 complex is also needed which leads to the need of a new drug design paradigm. Copyright © 2016 Elsevier Ltd. All rights reserved.

22 CFR 120.28 - Listing of forms referred to in this subchapter.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Listing of forms referred to in this subchapter. 120.28 Section 120.28 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS PURPOSE AND DEFINITIONS § 120.28 Listing of forms referred to in this subchapter. The forms referred to in...

22 CFR 120.28 - Listing of forms referred to in this subchapter.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Listing of forms referred to in this subchapter. 120.28 Section 120.28 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS PURPOSE AND DEFINITIONS § 120.28 Listing of forms referred to in this subchapter. The forms referred to in...

22 CFR 120.28 - Listing of forms referred to in this subchapter.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Listing of forms referred to in this subchapter. 120.28 Section 120.28 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS PURPOSE AND DEFINITIONS § 120.28 Listing of forms referred to in this subchapter. The forms referred to in...

22 CFR 120.28 - Listing of forms referred to in this subchapter.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Listing of forms referred to in this subchapter. 120.28 Section 120.28 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS PURPOSE AND DEFINITIONS § 120.28 Listing of forms referred to in this subchapter. The forms referred to in...

National Nutrition Education Clearing House Reference List, Preschool, Primary and Intermediate Teaching Materials and Teacher References.

ERIC Educational Resources Information Center

National Nutrition Education Clearing House, Berkeley, CA.

This is a reference list of teaching materials and teacher references of importance to teachers in the field of nutrition and nutrition education. It emphasizes resources for preschool, primary and intermediate grades. Although not a comprehensive list, resources include books, pamphlets, curriculum guides, article reprints, films and filmstrips,…

Multidisciplinary Meeting (MDM) Can Provide Education and Reinforcement of Inter-Professional Development

ERIC Educational Resources Information Center

Zafiropoulos, George; Byfield, David

2016-01-01

The introduction of a multidisciplinary meeting (MDM) was analysed through a retrospective empirical study. The question of using it as a valuable tool to reinforce inter-professional development was made. The data was collected from 60 forth year Chiropractic students, who were at the end of their education and who were practicing their…

MDM Observatory

NASA Astrophysics Data System (ADS)

Murdin, P.

2000-11-01

MDM Observatory was founded by the University of Michigan, Dartmouth College and the Massachusetts Institute of Technology. Current operating partners include Michigan, Dartmouth, MIT, Ohio State University and Columbia University. The observatory is located on the southwest ridge of the KITT PEAK NATIONAL OBSERVATORY near Tucson, Arizona. It operates the 2.4 m Hiltner Telescope and the 1.3 m McG...

12-mode OFDM transmission using reduced-complexity maximum likelihood detection.

PubMed

Lobato, Adriana; Chen, Yingkan; Jung, Yongmin; Chen, Haoshuo; Inan, Beril; Kuschnerov, Maxim; Fontaine, Nicolas K; Ryf, Roland; Spinnler, Bernhard; Lankl, Berthold

2015-02-01

We report the transmission of 163-Gb/s MDM-QPSK-OFDM and 245-Gb/s MDM-8QAM-OFDM transmission over 74 km of few-mode fiber supporting 12 spatial and polarization modes. A low-complexity maximum likelihood detector is employed to enhance the performance of a system impaired by mode-dependent loss.

Crosslanguage Lexical Activation: A Test of the Revised Hierarchical and Morphological Decomposition Models in Arabic-English Bilinguals

ERIC Educational Resources Information Center

Qasem, Mousa; Foote, Rebecca

2010-01-01

This study tested the predictions of the revised hierarchical (RHM) and morphological decomposition (MDM) models with Arabic-English bilinguals. The RHM (Kroll & Stewart, 1994) predicts that the amount of activation of first language translation equivalents is negatively correlated with second language (L2) proficiency. The MDM (Frost, Forster, &…

Long non-coding RNA ENST00462717 suppresses the proliferation, survival, and migration by inhibiting MDM2/MAPK pathway in glioma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Aiqin; Meng, Mingzhu; Zhao, Xiuhe

Gliomas are the most common and aggressive primary malignant tumor in the central nervous system, and requires new biomarkers and therapeutic methods. Long noncoding RNAs (lncRNAs) are important factors in numerous human diseases, including cancer. But studies on lncRNAs and gliomas are limited. In this study, we investigated the expression patterns of lncRNAs in 3 pairs of glioma samples and adjacent non-tumor tissues via microarray and selected the most down-regulated lnc00462717 to further verify its roles in glioma. We observed that decreased lnc00462717 expression was associated with the malignant status in glioma. In vitro experiment demonstrated that lnc00462717 overexpression suppressed gliomamore » cell proliferation, survival and migration while knockdown of lnc00462717 had an opposite result. Moreover, we identified MDM2 as a direct target of lnc00462717 and lnc00462717 played a role by partially regulating the MDM2/MAPK pathway. In conclusion, lnc00462717 may function in suppressing glioma cell proliferation, survival, migration and may potentially serve as a novel biomarker and therapeutic target for glioma. - Highlights: • Using microarray to investigate the expression patterns of lncRNAs in glioma. • Selecting the most down-regulated lnc00462717 via microarray to verify its roles. • Identifying MDM2 as a direct target of lnc00462717. • The mechanism of lnc00462717 regulating the MDM2/MAPK pathway. • lnc00462717 serve as a novel biomarker and therapeutic target for treating glioma.« less

Heme oxygenase-1 induction alters chemokine regulation and ameliorates human immunodeficiency virus-type-1 infection in lipopolysaccharide-stimulated macrophages

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Zhao-Hua; Kumari, Namita; Nekhai, Sergei

2013-06-07

Highlights: •Lipopolysaccharide stimulation of heme oxygenase-1 (HO-1) ameliorated HIV-1 infection of primary human macrophages. •The partial protection by HO-1 against HIV infection was associated with induction of chemokines such as MIP1α and MIP1β. •This mechanism explains lipopolysaccharide-stimulated HO-1-mediated inhibition of HIV-1 infection of macrophages. -- Abstract: We have elucidated a putative mechanism for the host resistance against HIV-1 infection of primary human monocyte-derived macrophages (MDM) stimulated with lipopolysaccharide (LPS). We show that LPS-activated MDM both inhibited HIV-1 entry into the cells and were refractory to post-entry productive viral replication. LPS-treated cells were virtually negative for mature virions as revealed bymore » transmission electron microscopy. LPS activation of MDM markedly enhanced the expression of heme oxygenase-1 (HO-1), a potent inducible cytoprotective enzyme. Increased HO-1 expression was accompanied by elevated production of macrophage inflammatory chemokines (MIP1α and MIP1β) by LPS-activated MDM, significantly decreased surface chemokine receptor-5 (CCR-5) expression, and substantially reduced virus replication. Treatment of cells with HO-1 inhibitor SnPP IX (tin protoporphyrin IX) attenuated the LPS-mediated responses, HIV-1 replication and secretion of MIP1α, MIP1β, and LD78β chemokines with little change in surface CCR-5 expression. These results identify a novel role for HO-1 in the modulation of host immune response against HIV infection of MDM.« less

Impact of NGO run mid day meal program on nutrition status and growth of primary school children.

PubMed

Sharma, A K; Singh, Samiksha; Meena, Sonali; Kannan, A T

2010-07-01

To study the impact of wholesome mid day meal (MDM) program run by an NGO on the growth of the primary school students in rural area of Mathura district. This intervention study involved children enrolled in Government run rural primary schools in Mathura district in Uttar Pradesh from March 06 through August 07. A wholesome, nutritionally balanced MDM provided by an NGO for the students in the 6 primary schools was selected as intervention group. Control group consisted of children in 8 schools which received locally prepared MDM by village panchayats. Height, weight, change in height/month, change in weight/month, prevalence of protein-energy malnutrition and prevalence of signs of vitamin deficiencies, were measured. Food was provided for 221 days in one year. Within group and between groups repetitive measures were compared using generalized estimating equation (GEE). Within both intervention and control groups height and weight had significantly increased (p < 0.05), while there was no significant difference between the groups. There was no change in prevalence of malnutrition within either of the groups. Reduction in vitamin A deficiency signs was 38% more in intervention group (p < 0.001). Prevalence of Vitamin D deficiency reduced by 50% more in intervention group. No such differences between groups were observed for vitamin B complex and vitamin C. MDM provided by the NGO has no better impact on growth of the primary school children, however, it reduced prevalence of vitamin deficiency significantly in comparison to the MDM run by Village Panchayats.

Jewish Studies: A Guide to Reference Sources.

ERIC Educational Resources Information Center

McGill Univ., Montreal (Quebec). McLennan Library.

An annotated bibliography to the reference sources for Jewish Studies in the McLennan Library of McGill University (Canada) is presented. Any titles in Hebrew characters are listed by their transliterated equivalents. There is also a list of relevant Library of Congress Subject Headings. General reference sources listed are: encyclopedias,…

The spectrum of clinical presentation, diagnosis, and management of mitochondrial forms of diabetes.

PubMed

Karaa, Amel; Goldstein, Amy

2015-02-01

Primary mitochondrial diseases refer to a group of heterogeneous and complex genetic disorders affecting 1:5000 people. The true prevalence is anticipated to be even higher because of the complexity of achieving a diagnosis in many patients who present with multisystemic complaints ranging from infancy to adulthood. Diabetes is a prominent feature of several of these disorders which might be overlooked by the endocrinologist. We here review mitochondrial disorders and describe the phenotypic and pathogenetic differences between mitochondrial diabetes mellitus (mDM) and other more common forms of diabetes mellitus. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The Mental Disability Military Assessment Tool: A Reliable Tool for Determining Disability in Veterans with Post-traumatic Stress Disorder.

PubMed

Fokkens, Andrea S; Groothoff, Johan W; van der Klink, Jac J L; Popping, Roel; Stewart, Roy E; van de Ven, Lex; Brouwer, Sandra; Tuinstra, Jolanda

2015-09-01

An assessment tool was developed to assess disability in veterans who suffer from post-traumatic stress disorder (PTSD) due to a military mission. The objective of this study was to determine the reliability, intra-rater and inter-rater variation of the Mental Disability Military (MDM) assessment tool. Twenty-four assessment interviews of veterans with an insurance physician were videotaped. Each videotaped interview was assessed by a group of five independent raters on limitations of the veterans using the MDM assessment tool. After 2 months the raters repeated this procedure. Next the intra-rater and inter-rater variation was assessed with an adjusted version of AG09 computing weighted percentage agreement. The results of this study showed that both the intra-rater variation and inter-rater variation on the ten subcategories of the MDM assessment tool were small, with an agreement of 84-100% within raters and 93-100% between raters. The MDM assessment tool proves to be a reliable instrument to measure PTSD limitations in functioning in Dutch military veterans who apply for disability compensation. Further research is needed to assess the validity of this instrument.

Dual targeting of MDM2 and BCL2 as a therapeutic strategy in neuroblastoma.

PubMed

Van Goethem, Alan; Yigit, Nurten; Moreno-Smith, Myrthala; Vasudevan, Sanjeev A; Barbieri, Eveline; Speleman, Frank; Shohet, Jason; Vandesompele, Jo; Van Maerken, Tom

2017-08-22

Wild-type p53 tumor suppressor activity in neuroblastoma tumors is hampered by increased MDM2 activity, making selective MDM2 antagonists an attractive therapeutic strategy for this childhood malignancy. Since monotherapy in cancer is generally not providing long-lasting clinical responses, we here aimed to identify small molecule drugs that synergize with idasanutlin (RG7388). To this purpose we evaluated 15 targeted drugs in combination with idasanutlin in three p53 wild type neuroblastoma cell lines and identified the BCL2 inhibitor venetoclax (ABT-199) as a promising interaction partner. The venetoclax/idasanutlin combination was consistently found to be highly synergistic in a diverse panel of neuroblastoma cell lines, including cells with high MCL1 expression levels. A more pronounced induction of apoptosis was found to underlie the synergistic interaction, as evidenced by caspase-3/7 and cleaved PARP measurements. Mice carrying orthotopic xenografts of neuroblastoma cells treated with both idasanutlin and venetoclax had drastically lower tumor weights than mice treated with either treatment alone. In conclusion, these data strongly support the further evaluation of dual BCL2/MDM2 targeting as a therapeutic strategy in neuroblastoma.

Melatonin and vitamin D3 synergistically down-regulate Akt and MDM2 leading to TGFβ-1-dependent growth inhibition of breast cancer cells.

PubMed

Proietti, Sara; Cucina, Alessandra; D'Anselmi, Fabrizio; Dinicola, Simona; Pasqualato, Alessia; Lisi, Elisabetta; Bizzarri, Mariano

2011-03-01

Melatonin and vitamin D3 inhibit breast cancer cell growth and induce apoptosis, but they have never been combined as a breast cancer treatment. Therefore, we investigated whether their association could lead to an enhanced anticancer activity. In MCF-7 breast cancer cells, melatonin together with vitamin D3, induced a synergistic proliferative inhibition, with an almost complete cell growth arrest at 144 hr. Cell growth blockade is associated to an activation of the TGFβ-1 pathway, leading to increased TGFβ-1, Smad4 and phosphorylated-Smad3 levels. Concomitantly, melatonin and D3, alone or in combination, caused a significant reduction in Akt phosphorylation and MDM2 values, with a consequent increase of p53/MDM2 ratio. These effects were completely suppressed by adding a monoclonal anti-TGFβ-1 antibody to the culture medium. Taken together, these results indicate that cytostatic effects triggered by melatonin and D3 are likely related to a complex TGFβ-1-dependent mechanism, involving down-regulation of both MDM2 and Akt-phosphorylation. © 2010 The Authors. Journal of Pineal Research © 2010 John Wiley & Sons A/S.

A facile method to screen inhibitors of protein-protein interactions including MDM2-p53 displayed on T7 phage.

PubMed

Ishi, Kazutomo; Sugawara, Fumio

2008-05-01

Protein-protein interactions are essential in many biological processes including cell cycle and apoptosis. It is currently of great medical interest to inhibit specific protein-protein interactions in order to treat a variety of disease states. Here, we describe a facile multiwell plate assay method using T7 phage display to screen for candidate inhibitors of protein-protein interactions. Because T7 phage display is an effective method for detecting protein-protein interactions, we aimed to utilize this technique to screen for small-molecule inhibitors that disrupt these types of interaction. We used the well-characterized interaction between p53 and MDM2 and an inhibitor of this interaction, nutlin 3, as a model system to establish a new screening method. Phage particles displaying p53 interacted with GST-MDM2 immobilized on 96-well plates, and the interaction was inhibited by nutlin 3. Multiwell plate assay was then performed using a natural product library, which identified dehydroaltenusin as a candidate inhibitor of the p53-MDM2 interaction. We discuss the potential applications of this novel T7 phage display methodology, which we propose to call 'reverse phage display'.

Rocket exhaust ground cloud/atmospheric interactions

NASA Technical Reports Server (NTRS)

Hwang, B.; Gould, R. K.

1978-01-01

An attempt to identify and minimize the uncertainties and potential inaccuracies of the NASA Multilayer Diffusion Model (MDM) is performed using data from selected Titan 3 launches. The study is based on detailed parametric calculations using the MDM code and a comparative study of several other diffusion models, the NASA measurements, and the MDM. The results are discussed and evaluated. In addition, the physical/chemical processes taking place during the rocket cloud rise are analyzed. The exhaust properties and the deluge water effects are evaluated. A time-dependent model for two aerosol coagulations is developed and documented. Calculations using this model for dry deposition during cloud rise are made. A simple model for calculating physical properties such as temperature and air mass entrainment during cloud rise is also developed and incorporated with the aerosol model.

Ultrasound-guided fine-needle aspiration of a posterior neck dedifferentiated liposarcoma with MDM2 fluorescence in situ hybridization performed on a Pap-stained smear.

PubMed

Zreik, Riyam; Soyalp, Krystal; Ruiz, Steve; Ward, Russell; Dobin, Sheila; Chen, Xiangbai; Liu, Lina; Rao, Arundhati

2015-04-01

Head and neck liposarcomas, while rare, tend to be subcutaneous and well-differentiated. Dedifferentiated liposarcomas of the head and neck are exceedingly rare in the literature. We present a case of a dedifferentiated liposarcoma arising in the soft tissue of the posterior neck of an 86-year-old man and diagnosed by fine-needle aspiration. Aspirate smears showed a dual population of atypical lipomatous and spindled cells. MDM2 (murine double minute 2) amplification was demonstrated on a Pap-stained smear using fluorescence in situ hybridization (FISH). To the best of our knowledge, this is the first report of MDM2 FISH amplification in a liposarcoma performed on an aspirate smear. © 2014 Wiley Periodicals, Inc.

Effect of Spatial Locality Prefetching on Structural Locality

DTIC Science & Technology

1991-12-01

Pollution module calculates the SLC and CAM cache pollution percentages. And finally, the Generate Reference Frequency List module produces the output...3.2.5 Generate Reference Frequency List 3.2.6 Each program module in the structure chart is mapped into an Ada package. By performing this encapsulation...call routine to generate reference -- frequency list -- end if -- end loop -- close input, output, and reference files end Cache Simulator Figure 3.5

Reference Materials and Subject Matter Knowledge Codes for Airman Knowledge Testing

DOT National Transportation Integrated Search

2004-06-08

The listings of reference materials and subject matter knowledge codes have been : prepared by the Federal Aviation Administration (FAA) to establish specific : references for all knowledge standards. The listings contain reference materials : to be ...

Influence of zinc deficiency on AKT-MDM2-P53 signaling axes in normal and malignant human prostate cells

USDA-ARS?s Scientific Manuscript database

With prostate being the highest zinc-accumulating tissue before the onset of cancer, the effects of physiologic levels of zinc on Akt-Mdm2-p53 and Akt-p21 signaling axes in human normal prostate epithelial cells (PrEC) and malignant prostate LNCaP cells were examined. Cells were cultured for 6 d in...

Genome-wide Mechanosensitive MicroRNA (MechanomiR) Screen Uncovers Dysregulation of Their Regulatory Networks in the mdm Mouse Model of Muscular Dystrophy.

PubMed

Mohamed, Junaith S; Hajira, Ameena; Lopez, Michael A; Boriek, Aladin M

2015-10-09

Muscular dystrophies (MDs) are a heterogeneous group of genetic and neuromuscular disorders, which result in severe loss of motor ability and skeletal muscle mass and function. Aberrant mechanotransduction and dysregulated-microRNA pathways are often associated with the progression of MD. Here, we hypothesized that dysregulation of mechanosensitive microRNAs (mechanomiRs) in dystrophic skeletal muscle plays a major role in the progression of MD. To test our hypothesis, we performed a genome-wide expression profile of anisotropically regulated mechanomiRs and bioinformatically analyzed their target gene networks. We assessed their functional roles in the advancement of MD using diaphragm muscles from mdm (MD with myositis) mice, an animal model of human tibial MD (titinopathy), and their wild-type littermates. We were able to show that ex vivo anisotropic mechanical stretch significantly alters the miRNA expression profile in diaphragm muscles from WT and mdm mice; as a result, some of the genes associated with MDs are dysregulated in mdm mice due to differential regulation of a distinct set of mechanomiRs. Interestingly, we found a contrasting expression pattern of the highly expressed let-7 family mechanomiRs, let-7e-5p and miR-98-5p, and their target genes associated with the extracellular matrix and TGF-β pathways, respectively, between WT and mdm mice. Gain- and loss-of-function analysis of let-7e-5p in myocytes isolated from the diaphragms of WT and mdm mice confirmed Col1a1, Col1a2, Col3a1, Col24a1, Col27a1, Itga1, Itga4, Scd1, and Thbs1 as target genes of let-7e-5p. Furthermore, we found that miR-98 negatively regulates myoblast differentiation. Our study therefore introduces additional biological players in the regulation of skeletal muscle structure and myogenesis that may contribute to unexplained disorders of MD. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

p53 participates in the protective effects of ischemic post-conditioning against OGD-reperfusion injury in primary cultured spinal cord neurons.

PubMed

Li, Jinquan; Chen, Gong; Gao, Xinjie; Shen, Chao; Zhou, Ping; Wu, Xing; Che, Xiaoming; Xie, Rong

2017-01-18

Spinal cord ischemia-reperfusion (I/R) injury is a severe clinical condition, while the mechanism is still not clarified and the therapeutic approach is limited. Ischemia post-conditioning (PC) has been found to have the protective effects against I/R injury in brain. Recently p53 has been reported to take part in the regulation and protection of I/R injury. We hypothesize that PC has the protective effects in primary cultured spinal cord neurons against ischemia-reperfusion injury, and MDM2-p53 signaling pathway may involve in its protective mechanism. In this study, we used an OGD (oxygen and glucose deprivation)-reperfusion model in primary cultured spinal cord neurons to simulate the I/R injury of spinal cord in vitro, and PC was conducted by 3 cycles of 15min restoration of glucose and oxygen with 15min OGD, followed by 6h fully restoration as reperfusion. Lentiviral vectors were used to knock down MDM2 or over-express p53 genes in primary cultured spinal cord neurons. The results showed that 3 cycles of 15min PC generated the most significant protective effects in primary cultured spinal cord neurons against OGD-reperfusion injury. The levels of MDM2 were decreased while p53, Bax, and cleaved Caspase 3 were increased under OGD-reperfusion condition. PC could significantly reverse the down-regulation of MDM2 and up-regulation of p53, Bax, and cleaved Caspase 3 by OGD-reperfusion injury. Moreover, MDM2 knockdown or p53 over-expression could induce the cleaved Caspase 3 expression and blocked the protective effects of PC in primary cultured spinal cord neurons against OGD-reperfusion injury. In conclusion, our work demonstrated that MDM2-p53 pathway plays a pivotal role in the protective effect of PC against OGD-reperfusion injury and PC may be a feasible therapy strategy in the treatment for spinal cord I/R injury. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Information Seeking Behavior and User Education in Academic Libraries: Research, Theory, and Practice. A Selected List of Information Sources.

ERIC Educational Resources Information Center

Fridie, Stephanie, Comp.

This document lists sources useful for academic reference and instruction librarians who are concerned with assisting and teaching novice or non-professional end-user searchers. The bibliography is organized in two lists: complete bibliographic citations and subject listing of references. The types of sources listed include journal articles,…

Lanthanide-doped nanoparticles conjugated with an anti-CD33 antibody and a p53-activating peptide for acute myeloid leukemia therapy.

PubMed

Niu, Fan; Yan, Jin; Ma, Bohan; Li, Shichao; Shao, Yongping; He, Pengcheng; Zhang, Wanggang; He, Wangxiao; Ma, Peter X; Lu, Wuyuan

2018-06-01

Roughly one third of all human cancers are attributable to the functional inhibition of the tumor suppressor protein p53 by its two negative regulators MDM2 and MDMX, making dual-specificity peptide antagonists of MDM2 and MDMX highly attractive drug candidates for anticancer therapy. Two pharmacological barriers, however, remain a major obstacle to the development of peptide therapeutics: susceptibility to proteolytic degradation in vivo and inability to traverse the cell membrane. Here we report the design of a fluorescent lanthanide oxyfluoride nanoparticle (LONp)-based multifunctional peptide drug delivery system for potential treatment of acute myeloid leukemia (AML) that commonly harbors wild type p53, high levels of MDM2 and/or MDMX, and an overexpressed cell surface receptor, CD33. We conjugated to LONp via metal-thiolate bonds a dodecameric peptide antagonist of both MDM2 and MDMX, termed PMI, and a CD33-targeted, humanized monoclonal antibody to allow for AML-specific intracellular delivery of a stabilized PMI. The resultant nanoparticle antiCD33-LONp-PMI, while nontoxic to normal cells, induced apoptosis of AML cell lines and primary leukemic cells isolated from AML patients by antagonizing MDM2 and/or MDMX to activate the p53 pathway. Fluorescent antiCD33-LONp-PMI also enabled real-time visualization of a series of apoptotic events in AML cells, proving a useful tool for possible disease tracking and treatment response monitoring. Our studies shed light on the development of antiCD33-LONp-PMI as a novel class of antitumor agents, which, if further validated, may help targeted molecular therapy of AML. Copyright © 2018 Elsevier Ltd. All rights reserved.

In vitro permissiveness of bovine neutrophils and monocyte derived macrophages to Leishmania donovani of Ethiopian isolate.

PubMed

Tasew, Geremew; Gadisa, Endalamaw; Abera, Adugna; Zewude, Aboma; Chanyalew, Menberework; Aseffa, Abraham; Abebe, Markos; Ritter, Uwe; van Zandbergen, Ger; Laskay, Tamás; Tafess, Ketema

2016-04-18

Epidemiological studies in Ethiopia have documented that the risk of visceral leishmaniasis (VL, Kala-azar) is higher among people living with domestic animals. The recent report on isolation of Leishmania donovani complex DNA and the detected high prevalence of anti-leishmanial antibodies in the blood of domestic animals further strengthen the potential role of domestic animals in the epidemiology of VL in Ethiopia. In mammalian hosts polymorphonuclear cells (PMN) and macrophages are the key immune cells influencing susceptibility or control of Leishmania infection. Thus to substantiate the possible role of cattle in VL transmission we investigate the permissiveness of bovine PMN and monocyte derived macrophages (MDM) for Leishmania (L.) donovani infection. Whole blood was collected from pure Zebu (Boss indicus) and their cross with Holstein Friesian cattle. L. donovani (MHOM/ET/67/HU3) wild and episomal green fluorescent protein (eGFP) labelled stationary stage promastigotes were co-incubated with whole blood and MDM to determine infection of these cells. Engulfment of promastigotes by the cells and their transformation to amastigote forms in MDM was studied with direct microscopy. Microscopy and flow cytometry were used to measure the infection rate while PCR-RLFP was used to confirm the infecting parasite. L. donovani infected bovine whole blood PMN in the presence of plasma factors and all cellular elements. Morphological examinations of stained cytospin smears revealed that PMN engulfed promastigotes. Similarly, we were able to show that bovine MDM can be infected by L. donovani, which transformed to amastigote forms in the cells. The in vitro infection of bovine PMN and MDM by L. donovani further strengthens the possibility that cattle might serve as source of L. donovani infection for humans.

The dual action of poly(ADP-ribose) polymerase -1 (PARP-1) inhibition in HIV-1 infection: HIV-1 LTR inhibition and diminution in Rho GTPase activity

PubMed Central

Rom, Slava; Reichenbach, Nancy L.; Dykstra, Holly; Persidsky, Yuri

2015-01-01

Multifactorial mechanisms comprising countless cellular factors and virus-encoded transactivators regulate the transcription of HIV-1 (HIV). Since poly(ADP-ribose) polymerase 1 (PARP-1) regulates numerous genes through its interaction with various transcription factors, inhibition of PARP-1 has surfaced recently as a powerful anti-inflammatory tool. We suggest a novel tactic to diminish HIV replication via PARP-1 inhibition in an in vitro model system, exploiting human primary monocyte-derived macrophages (MDM). PARP-1 inhibition was capable to lessen HIV replication in MDM by 60–80% after 7 days infection. Tat, tumor necrosis factor α (TNFα), and phorbol 12-myristate 13-acetate (PMA) are known triggers of the Long Terminal Repeat (LTR), which can switch virus replication. Tat overexpression in MDM transfected with an LTR reporter plasmid resulted in a 4.2-fold increase in LTR activation; PARP inhibition caused 70% reduction of LTR activity. LTR activity, which increased 3-fold after PMA or TNFα treatment, was reduced by PARP inhibition (by 85–95%). PARP inhibition in MDM exhibited 90% diminution in NFκB activity (known to mediate TNFα- and PMA-induced HIV LTR activation). Cytoskeleton rearrangements are important in effective HIV-1 infection. PARP inactivation reduced actin cytoskeleton rearrangements by affecting Rho GTPase machinery. These discoveries suggest that inactivation of PARP suppresses HIV replication in MDM by via attenuation of LTR activation, NFκB suppression and its effects on the cytoskeleton. PARP appears to be essential for HIV replication and its inhibition may provide an effective approach to management of HIV infection. PMID:26379653

The dual action of poly(ADP-ribose) polymerase -1 (PARP-1) inhibition in HIV-1 infection: HIV-1 LTR inhibition and diminution in Rho GTPase activity.

PubMed

Rom, Slava; Reichenbach, Nancy L; Dykstra, Holly; Persidsky, Yuri

2015-01-01

Multifactorial mechanisms comprising countless cellular factors and virus-encoded transactivators regulate the transcription of HIV-1 (HIV). Since poly(ADP-ribose) polymerase 1 (PARP-1) regulates numerous genes through its interaction with various transcription factors, inhibition of PARP-1 has surfaced recently as a powerful anti-inflammatory tool. We suggest a novel tactic to diminish HIV replication via PARP-1 inhibition in an in vitro model system, exploiting human primary monocyte-derived macrophages (MDM). PARP-1 inhibition was capable to lessen HIV replication in MDM by 60-80% after 7 days infection. Tat, tumor necrosis factor α (TNFα), and phorbol 12-myristate 13-acetate (PMA) are known triggers of the Long Terminal Repeat (LTR), which can switch virus replication. Tat overexpression in MDM transfected with an LTR reporter plasmid resulted in a 4.2-fold increase in LTR activation; PARP inhibition caused 70% reduction of LTR activity. LTR activity, which increased 3-fold after PMA or TNFα treatment, was reduced by PARP inhibition (by 85-95%). PARP inhibition in MDM exhibited 90% diminution in NFκB activity (known to mediate TNFα- and PMA-induced HIV LTR activation). Cytoskeleton rearrangements are important in effective HIV-1 infection. PARP inactivation reduced actin cytoskeleton rearrangements by affecting Rho GTPase machinery. These discoveries suggest that inactivation of PARP suppresses HIV replication in MDM by via attenuation of LTR activation, NFκB suppression and its effects on the cytoskeleton. PARP appears to be essential for HIV replication and its inhibition may provide an effective approach to management of HIV infection.

Multiple dual mode counter-current chromatography with variable duration of alternating phase elution steps.

PubMed

Kostanyan, Artak E; Erastov, Andrey A; Shishilov, Oleg N

2014-06-20

The multiple dual mode (MDM) counter-current chromatography separation processes consist of a succession of two isocratic counter-current steps and are characterized by the shuttle (forward and back) transport of the sample in chromatographic columns. In this paper, the improved MDM method based on variable duration of alternating phase elution steps has been developed and validated. The MDM separation processes with variable duration of phase elution steps are analyzed. Basing on the cell model, analytical solutions are developed for impulse and non-impulse sample loading at the beginning of the column. Using the analytical solutions, a calculation program is presented to facilitate the simulation of MDM with variable duration of phase elution steps, which can be used to select optimal process conditions for the separation of a given feed mixture. Two options of the MDM separation are analyzed: 1 - with one-step solute elution: the separation is conducted so, that the sample is transferred forward and back with upper and lower phases inside the column until the desired separation of the components is reached, and then each individual component elutes entirely within one step; 2 - with multi-step solute elution, when the fractions of individual components are collected in over several steps. It is demonstrated that proper selection of the duration of individual cycles (phase flow times) can greatly increase the separation efficiency of CCC columns. Experiments were carried out using model mixtures of compounds from the GUESSmix with solvent systems hexane/ethyl acetate/methanol/water. The experimental results are compared to the predictions of the theory. A good agreement between theory and experiment has been demonstrated. Copyright © 2014 Elsevier B.V. All rights reserved.

HIV-1 subtype C unproductively infects human cardiomyocytes in vitro and induces apoptosis mitigated by an anti-Gp120 aptamer.

PubMed

Lopes de Campos, Walter R; Chirwa, Nthato; London, Grace; Rotherham, Lia S; Morris, Lynn; Mayosi, Bongani M; Khati, Makobetsa

2014-01-01

HIV-associated cardiomyopathy (HIVCM) is of clinical concern in developing countries because of a high HIV-1 prevalence, especially subtype C, and limited access to highly active antiretroviral therapy (HAART). For these reasons, we investigated the direct and indirect effects of HIV-1 subtype C infection of cultured human cardiomyocytes and the mechanisms leading to cardiomyocytes damage; as well as a way to mitigate the damage. We evaluated a novel approach to mitigate HIVCM using a previously reported gp120 binding and HIV-1 neutralizing aptamer called UCLA1. We established a cell-based model of HIVCM by infecting human cardiomyocytes with cell-free HIV-1 or co-culturing human cardiomyocytes with HIV-infected monocyte derived macrophages (MDM). We discovered that HIV-1 subtype C unproductively (i.e. its life cycle is arrested after reverse transcription) infects cardiomyocytes. Furthermore, we found that HIV-1 initiates apoptosis of cardiomyocytes through caspase-9 activation, preferentially via the intrinsic or mitochondrial initiated pathway. CXCR4 receptor-using viruses were stronger inducers of apoptosis than CCR5 utilizing variants. Importantly, we discovered that HIV-1 induced apoptosis of cardiomyocytes was mitigated by UCLA1. However, UCLA1 had no protective effective on cardiomyocytes when apoptosis was triggered by HIV-infected MDM. When HIV-1 was treated with UCLA1 prior to infection of MDM, it failed to induce apoptosis of cardiomyocytes. These data suggest that HIV-1 causes a mitochondrial initiated apoptotic cascade, which signal through caspase-9, whereas HIV-1 infected MDM causes apoptosis predominantly via the death-receptor pathway, mediated by caspase-8. Furthermore the data suggest that UCLA1 protects cardiomyocytes from caspase-mediated apoptosis, directly by binding to HIV-1 and indirectly by preventing infection of MDM.

High amplification levels of MDM2 and CDK4 correlate with poor outcome in patients with dedifferentiated liposarcoma: A cytogenomic microarray analysis of 47 cases.

PubMed

Ricciotti, Robert W; Baraff, Aaron J; Jour, George; Kyriss, McKenna; Wu, Yu; Liu, Yuhua; Li, Shao-Chun; Hoch, Benjamin; Liu, Yajuan J

2017-12-01

Dedifferentiated liposarcoma (DDLS) is characterized at the molecular level by amplification of genes within 12q13-15 including MDM2 and CDK4. However, other than FNCLCC grade, prognostic markers are limited. We aim to identify molecular prognostic markers for DDLS to help risk stratify patients. To this end, we studied 49 cases of DDLS in our institutional archives and performed cytogenomic microarray analysis on 47 cases. Gene copy numbers for 12 loci were evaluated and correlated with outcome data retrieved from our institutional electronic medical records. Using cut point analysis and comparison of Kaplan-Meier survival curves by log rank tests, high amplification levels of MDM2 (>38 copies) and CDK4 (>30 copies) correlated with decreased disease free survival (DFS) (P = .0168 and 0.0169 respectively) and disease specific survival (DSS) (P = .0082 and 0.0140 respectively). Additionally, MDM2 and CDK4 showed evidence of a synergistic effect so that each additional copy of one enhances the effect on prognosis of each additional copy of the other for decreased DFS (P = .0227, 0.1% hazard). High amplification of JUN (>16 copies) also correlated with decreased DFS (P = .0217), but not DSS. The presence of copy number alteration at 3q29 correlated with decreased DSS (P = .0192). The presence of >10 mitoses per 10 high power fields and FNCLCC grade 3 also correlated with decreased DFS (P = .0310 and 0.0254 respectively). MDM2 and CDK4 gene amplification levels, along with JUN amplification and copy alterations at 3q29, can be utilized for predicting outcome in patients with DDLS. Published by Elsevier Inc.

Targeting MDM2 for Treatment of Adenoid Cystic Carcinoma

PubMed Central

Warner, Kristy A.; Nör, Felipe; Acasigua, Gerson A.; Martins, Manoela D.; Zhang, Zhaocheng; McLean, Scott A.; Spector, Matthew E.; Chepeha, Douglas B.; Helman, Joseph; Wick, Michael J.; Moskaluk, Christopher A.; Castilho, Rogerio M.; Pearson, Alexander T.; Wang, Shaomeng; Nör, Jacques E.

2016-01-01

Purpose There are no effective treatment options for patients with advanced adenoid cystic carcinoma (ACC). Here, we evaluated the effect of a new small molecule inhibitor of the MDM2-p53 interaction (MI-773) in preclinical models of ACC. Experimental Design To evaluate the anti-tumor effect of MI-773, we administered it to mice harboring 3 different patient-derived xenograft (PDX) models of ACC expressing functional p53. The effect of MI-773 on MDM2, p53, phospho-p53 and p21 was examined by Western blots in 5 low passage primary human ACC cell lines and in MI-773-treated PDX tumors. Results Single agent MI-773 caused tumor regression in the 3 PDX models of ACC studied here. For example, we observed a tumor growth inhibition (TGI) index of 127% in UM-PDX-HACC-5 tumors that was associated with an increase in the fraction of apoptotic cells (p=0.015). The number of p53-positive cells was increased in MI-773-treated PDX tumors (p<0.001), with a correspondent shift in p53 localization from the nucleus to the cytoplasm. Western blots demonstrated that MI-773 potently induced expression of p53 and its downstream targets p21, MDM2 and induced phosphorylation of p53 (serine 392) in low passage primary human ACC cells. Notably, MI-773 induced a dose-dependent increase in the fraction of apoptotic ACC cells and in the fraction of cells in the G1 phase of cell cycle (p<0.05). Conclusions Collectively, these data demonstrate that therapeutic inhibition of the MDM2-p53 interaction with MI-773 activates downstream effectors of apoptosis and causes robust tumor regression in preclinical models of adenoid cystic carcinoma. PMID:26936915

Therapeutic inhibition of the MDM2-p53 interaction prevents recurrence of adenoid cystic carcinomas

PubMed Central

Nör, Felipe; Warner, Kristy A.; Zhang, Zhaocheng; Acasigua, Gerson A.; Pearson, Alexander T.; Kerk, Samuel A.; Helman, Joseph; Filho, Manoel Sant’Ana; Wang, Shaomeng; Nör, Jacques E.

2016-01-01

Purpose Conventional chemotherapy has modest efficacy in advanced adenoid cystic carcinomas (ACC). Tumor recurrence is a major challenge in the management of ACC patients. Here, we evaluated the anti-tumor effect of a novel small molecule inhibitor of the MDM2-p53 interaction (MI-773) combined with Cisplatin in patient-derived xenograft (PDX) ACC tumors. Experimental design Therapeutic strategies with MI-773 and/or Cisplatin were evaluated in SCID mice harboring PDX ACC tumors (UM-PDX-HACC-5) and in low passage primary human ACC cells (UM-HACC-2A, -2B, -5, -6) in vitro. The effect of therapy on the fraction of cancer stem cells was determined by flow cytometry for ALDH activity and CD44 expression. Results Combined therapy with MI-773 with Cisplatin caused p53 activation, induction of apoptosis, and regression of ACC PDX tumors. Western blots revealed induction of MDM2, p53 and downstream p21 expression, and regulation of apoptosis-related proteins PUMA, BAX, Bcl-2, Bcl-xL and active Caspase-9 upon MI-773 treatment. Both, single-agent MI-773, and MI-773 combined with Cisplatin, decreased the fraction of cancer stem cells in PDX ACC tumors. Notably, neoadjuvant MI-773 and surgery eliminated tumor recurrences during a post-surgical follow-up of more than 300 days. In contrast, 62.5% of mice that received vehicle control presented with palpable tumor recurrences within this time period (p=0.0097). Conclusions Collectively, these data demonstrate that therapeutic inhibition of MDM2-p53 interaction by MI-773 decreased the cancer stem cell fraction, sensitized ACC xenograft tumors to Cisplatin, and eliminated tumor recurrence. These results suggest that patients with ACC might benefit from the therapeutic inhibition of the MDM2-p53 interaction. PMID:27550999

Mode division multiplexing using an orbital angular momentum mode sorter and MIMO-DSP over a graded-index few-mode optical fibre

PubMed Central

Huang, Hao; Milione, Giovanni; Lavery, Martin P. J.; Xie, Guodong; Ren, Yongxiong; Cao, Yinwen; Ahmed, Nisar; An Nguyen, Thien; Nolan, Daniel A.; Li, Ming-Jun; Tur, Moshe; Alfano, Robert R.; Willner, Alan E.

2015-01-01

Mode division multiplexing (MDM)– using a multimode optical fiber’s N spatial modes as data channels to transmit N independent data streams – has received interest as it can potentially increase optical fiber data transmission capacity N-times with respect to single mode optical fibers. Two challenges of MDM are (1) designing mode (de)multiplexers with high mode selectivity (2) designing mode (de)multiplexers without cascaded beam splitting’s 1/N insertion loss. One spatial mode basis that has received interest is that of orbital angular momentum (OAM) modes. In this paper, using a device referred to as an OAM mode sorter, we show that OAM modes can be (de)multiplexed over a multimode optical fiber with higher than −15 dB mode selectivity and without cascaded beam splitting’s 1/N insertion loss. As a proof of concept, the OAM modes of the LP11 mode group (OAM−1,0 and OAM+1,0), each carrying 20-Gbit/s polarization division multiplexed and quadrature phase shift keyed data streams, are transmitted 5km over a graded-index, few-mode optical fibre. Channel crosstalk is mitigated using 4 × 4 multiple-input-multiple-output digital-signal-processing with <1.5 dB power penalties at a bit-error-rate of 2 × 10−3. PMID:26450398

Mode division multiplexing using an orbital angular momentum mode sorter and MIMO-DSP over a graded-index few-mode optical fibre.

PubMed

Huang, Hao; Milione, Giovanni; Lavery, Martin P J; Xie, Guodong; Ren, Yongxiong; Cao, Yinwen; Ahmed, Nisar; An Nguyen, Thien; Nolan, Daniel A; Li, Ming-Jun; Tur, Moshe; Alfano, Robert R; Willner, Alan E

2015-10-09

Mode division multiplexing (MDM)- using a multimode optical fiber's N spatial modes as data channels to transmit N independent data streams - has received interest as it can potentially increase optical fiber data transmission capacity N-times with respect to single mode optical fibers. Two challenges of MDM are (1) designing mode (de)multiplexers with high mode selectivity (2) designing mode (de)multiplexers without cascaded beam splitting's 1/N insertion loss. One spatial mode basis that has received interest is that of orbital angular momentum (OAM) modes. In this paper, using a device referred to as an OAM mode sorter, we show that OAM modes can be (de)multiplexed over a multimode optical fiber with higher than -15 dB mode selectivity and without cascaded beam splitting's 1/N insertion loss. As a proof of concept, the OAM modes of the LP11 mode group (OAM-1,0 and OAM+1,0), each carrying 20-Gbit/s polarization division multiplexed and quadrature phase shift keyed data streams, are transmitted 5km over a graded-index, few-mode optical fibre. Channel crosstalk is mitigated using 4 × 4 multiple-input-multiple-output digital-signal-processing with <1.5 dB power penalties at a bit-error-rate of 2 × 10(-3).

Mode division multiplexing using an orbital angular momentum mode sorter and MIMO-DSP over a graded-index few-mode optical fibre

NASA Astrophysics Data System (ADS)

Huang, Hao; Milione, Giovanni; Lavery, Martin P. J.; Xie, Guodong; Ren, Yongxiong; Cao, Yinwen; Ahmed, Nisar; An Nguyen, Thien; Nolan, Daniel A.; Li, Ming-Jun; Tur, Moshe; Alfano, Robert R.; Willner, Alan E.

2015-10-01

Mode division multiplexing (MDM)- using a multimode optical fiber’s N spatial modes as data channels to transmit N independent data streams - has received interest as it can potentially increase optical fiber data transmission capacity N-times with respect to single mode optical fibers. Two challenges of MDM are (1) designing mode (de)multiplexers with high mode selectivity (2) designing mode (de)multiplexers without cascaded beam splitting’s 1/N insertion loss. One spatial mode basis that has received interest is that of orbital angular momentum (OAM) modes. In this paper, using a device referred to as an OAM mode sorter, we show that OAM modes can be (de)multiplexed over a multimode optical fiber with higher than -15 dB mode selectivity and without cascaded beam splitting’s 1/N insertion loss. As a proof of concept, the OAM modes of the LP11 mode group (OAM-1,0 and OAM+1,0), each carrying 20-Gbit/s polarization division multiplexed and quadrature phase shift keyed data streams, are transmitted 5km over a graded-index, few-mode optical fibre. Channel crosstalk is mitigated using 4 × 4 multiple-input-multiple-output digital-signal-processing with <1.5 dB power penalties at a bit-error-rate of 2 × 10-3.

VizieR Online Data Catalog: NIR spectroscopy of Galactic WR stars. III (Kanarek+, 2015)

NASA Astrophysics Data System (ADS)

Kanarek, G.; Shara, M.; Faherty, J.; Zurek, D.; Moffat, A.

2016-02-01

This survey was previously described in Paper I (Shara et al., 2009AJ....138..402S). More than 88000 exposures were taken of the Galactic plane on the Cerro Tololo Inter-American Observatory (CTIO) 1.5-m telescope over approximately 200 nights during 2005-2006. IRTF: at the 3m NASA Infrared Telescope Facility (IRTF), we obtained NIR spectra of 150 candidate WR stars, selected using the criteria above, with the SpeX spectrograph. MDM 2011: during a run of excellent weather over the seven nights in 2011 June, we obtained 113 NIR spectra of candidate stars using TIFKAM in spectroscopic mode on the 2.4m Hiltner telescope at MDM Observatory. MDM 2012: during early 2012, the original survey data were reduced again, using different methods to produce better images. (10 data files).

The inhibition of calcium carbonate crystal growth by the cysteine-rich Mdm2 peptide.

PubMed

Dalas, E; Chalias, A; Gatos, D; Barlos, K

2006-08-15

The crystal growth of calcite, the most stable calcium carbonate polymorph, in the presence of the cysteine-rich Mdm2 peptide (containing 48 amino acids in the ring finger configuration), has been investigated by the constant composition technique. Crystallization took place exclusively on well-characterized calcite crystals in solutions supersaturated only with respect to this calcium carbonate salt. The kinetic results indicated a surface diffusion spiral growth mechanism. The presence of the Mdm2 peptide inhibited the crystal growth of calcite by 22-58% in the concentration range tested, through adsorption onto the active growth sites of the calcite crystal surface. The kinetic results favored a Langmuir-type adsorption model, and the value of the calculated affinity constant was k(aff)=147x10(4) dm(3)mol(-1), a(ads)=0.29.

Advisory List of Reference Books for Grades K-6.

ERIC Educational Resources Information Center

North Carolina State Dept. of Public Instruction, Raleigh. Div. of Educational Media.

Intended to serve as a guide rather than as a comprehensive listing, this advisory list includes reference books appropriate for school media collections for grades K-6. Entries included on the list were selected from those materials submitted by publishers which received favorable reviews by educators. Single volumes and sets of books are listed…

[Measles vaccination campaign for vulnerable populations: lessons learned].

PubMed

Laurence, Sophie; Chappuis, Marielle; Lucas, Dorinela; Duteurtre, Martin; Corty, Jean-François

2013-01-01

Between 2008 and 2011, a measles epidemic raged in France. Immunization coverage in France, already insufficient in the general population, is even more worrying for deprived populations in whom exposure to the disease and the risk of complications are much higher. In this context, Medecins du Monde (MdM), the General Council of the Seine-Saint-Denis (CG93) and the Territorial Directorate of the Regional Health Agency (DTARS) implemented a measles vaccination campaign among the Rom population of the department. The objective was to improve coverage of this population by providing ambulatory services in collaboration between various field partners in a single public health project. Twenty-two of the known Rom settlements were selected to receive vaccination. MdM was in charge of logistics, mediation and vaccinations at 13 sites and the DTARS and CG93 were in charge of vaccination at another 9 sites with support from MdM for mediation and logistics. Between January and June 2012, 250 persons were vaccinated, 34.7% of the target population. Coverage of the population after the vaccination campaign was still very low. The partnership between MdM, DTARS and CG93 helped to create a positive mobile action experience and extended prevention actions towards the most vulnerable populations excluded from conventional health care structures.

p53 prevents progression of nevi to melanoma predominantly through cell cycle regulation

PubMed Central

Terzian, Tamara; Torchia, Enrique C.; Dai, Daisy; Robinson, Steven E.; Murao, Kazutoshi; Stiegmann, Regan A.; Gonzalez, Victoria; Boyle, Glen M.; Powell, Marianne B.; Pollock, Pamela M.; Lozano, Guillermina; Robinson, William A.; Roop, Dennis R.; Box, Neil F.

2011-01-01

p53 is the central member of a critical tumor suppressor pathway in virtually all tumor types, where it is silenced mainly by missense mutations. In melanoma, p53 predominantly remains wild type, thus its role has been neglected. To study the effect of p53 on melanocyte function and melanomagenesis, we crossed the ‘high-p53’ Mdm4+/− mouse to the well-established TP-ras0/+ murine melanoma progression model. After treatment with the carcinogen dimethylbenzanthracene (DMBA), TP-ras0/+ mice on the Mdm4+/− background developed fewer tumors with a delay in the age of onset of melanomas compared to TP-ras0/+ mice. Furthermore, we observed a dramatic decrease in tumor growth, lack of metastasis with increased survival of TP-ras0/+: Mdm4+/− mice. Thus, p53 effectively prevented the conversion of small benign tumors to malignant and metastatic melanoma. p53 activation in cultured primary melanocyte and melanoma cell lines using Nutlin-3, a specific Mdm2 antagonist, supported these findings. Moreover, global gene expression and network analysis of Nutlin-3-treated primary human melanocytes indicated that cell cycle regulation through the p21WAF1/CIP1 signaling network may be the key anti-melanomagenic activity of p53. PMID:20849464

Stapled α−helical peptide drug development: A potent dual inhibitor of MDM2 and MDMX for p53-dependent cancer therapy

PubMed Central

Chang, Yong S.; Graves, Bradford; Guerlavais, Vincent; Tovar, Christian; Packman, Kathryn; To, Kwong-Him; Olson, Karen A.; Kesavan, Kamala; Gangurde, Pranoti; Mukherjee, Aditi; Baker, Theresa; Darlak, Krzysztof; Elkin, Carl; Filipovic, Zoran; Qureshi, Farooq Z.; Cai, Hongliang; Berry, Pamela; Feyfant, Eric; Shi, Xiangguo E.; Horstick, James; Annis, D. Allen; Manning, Anthony M.; Fotouhi, Nader; Nash, Huw; Vassilev, Lyubomir T.; Sawyer, Tomi K.

2013-01-01

Stapled α−helical peptides have emerged as a promising new modality for a wide range of therapeutic targets. Here, we report a potent and selective dual inhibitor of MDM2 and MDMX, ATSP-7041, which effectively activates the p53 pathway in tumors in vitro and in vivo. Specifically, ATSP-7041 binds both MDM2 and MDMX with nanomolar affinities, shows submicromolar cellular activities in cancer cell lines in the presence of serum, and demonstrates highly specific, on-target mechanism of action. A high resolution (1.7-Å) X-ray crystal structure reveals its molecular interactions with the target protein MDMX, including multiple contacts with key amino acids as well as a role for the hydrocarbon staple itself in target engagement. Most importantly, ATSP-7041 demonstrates robust p53-dependent tumor growth suppression in MDM2/MDMX-overexpressing xenograft cancer models, with a high correlation to on-target pharmacodynamic activity, and possesses favorable pharmacokinetic and tissue distribution properties. Overall, ATSP-7041 demonstrates in vitro and in vivo proof-of-concept that stapled peptides can be developed as therapeutically relevant inhibitors of protein–protein interaction and may offer a viable modality for cancer therapy. PMID:23946421

A multiobjective decision support/numerical modeling approach for design and evaluation of shallow landfill burial systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ascough, II, James Clifford

1992-05-01

The capability to objectively evaluate design performance of shallow landfill burial (SLB) systems is of great interest to diverse scientific disciplines, including hydrologists, engineers, environmental scientists, and SLB regulators. The goal of this work was to develop and validate a procedure for the nonsubjective evaluation of SLB designs under actual or simulated environmental conditions. A multiobjective decision module (MDM) based on scoring functions (Wymore, 1988) was implemented to evaluate SLB design performance. Input values to the MDM are provided by hydrologic models. The MDM assigns a total score to each SLB design alternative, thereby allowing for rapid and repeatable designmore » performance evaluation. The MDM was validated for a wide range of SLB designs under different climatic conditions. Rigorous assessment of SLB performance also requires incorporation of hydrologic probabilistic analysis and hydrologic risk into the overall design. This was accomplished through the development of a frequency analysis module. The frequency analysis module allows SLB design event magnitudes to be calculated based on the hydrologic return period. The multiobjective decision and freqeuncy anslysis modules were integrated in a decision support system (DSS) framework, SLEUTH (Shallow Landfill Evaluation Using Transport and Hydrology). SLEUTH is a Microsoft Windows {trademark} application, and is written in the Knowledge Pro Windows (Knowledge Garden, Inc., 1991) development language.« less

TP53 and MDM2 single nucleotide polymorphisms influence survival in non-del(5q) myelodysplastic syndromes

PubMed Central

Sallman, David A.; Basiorka, Ashley A.; Irvine, Brittany A.; Zhang, Ling; Epling-Burnette, P.K.; Rollison, Dana E.; Mallo, Mar; Sokol, Lubomir; Solé, Francesc; Maciejewski, Jaroslaw; List, Alan F.

2015-01-01

P53 is a key regulator of many cellular processes and is negatively regulated by the human homolog of murine double minute-2 (MDM2) E3 ubiquitin ligase. Single nucleotide polymorphisms (SNPs) of either gene alone, and in combination, are linked to cancer susceptibility, disease progression, and therapy response. We analyzed the interaction of TP53 R72P and MDM2 SNP309 SNPs in relationship to outcome in patients with myelodysplastic syndromes (MDS). Sanger sequencing was performed on DNA isolated from 208 MDS cases. Utilizing a novel functional SNP scoring system ranging from +2 to −2 based on predicted p53 activity, we found statistically significant differences in overall survival (OS) (p = 0.02) and progression-free survival (PFS) (p = 0.02) in non-del(5q) MDS patients with low functional scores. In univariate analysis, only IPSS and the functional SNP score predicted OS and PFS in non-del(5q) patients. In multivariate analysis, the functional SNP score was independent of IPSS for OS and PFS. These data underscore the importance of TP53 R72P and MDM2 SNP309 SNPs in MDS, and provide a novel scoring system independent of IPSS that is predictive for disease outcome. PMID:26416416

Effective screening strategy using ensembled pharmacophore models combined with cascade docking: application to p53-MDM2 interaction inhibitors.

PubMed

Xue, Xin; Wei, Jin-Lian; Xu, Li-Li; Xi, Mei-Yang; Xu, Xiao-Li; Liu, Fang; Guo, Xiao-Ke; Wang, Lei; Zhang, Xiao-Jin; Zhang, Ming-Ye; Lu, Meng-Chen; Sun, Hao-Peng; You, Qi-Dong

2013-10-28

Protein-protein interactions (PPIs) play a crucial role in cellular function and form the backbone of almost all biochemical processes. In recent years, protein-protein interaction inhibitors (PPIIs) have represented a treasure trove of potential new drug targets. Unfortunately, there are few successful drugs of PPIIs on the market. Structure-based pharmacophore (SBP) combined with docking has been demonstrated as a useful Virtual Screening (VS) strategy in drug development projects. However, the combination of target complexity and poor binding affinity prediction has thwarted the application of this strategy in the discovery of PPIIs. Here we report an effective VS strategy on p53-MDM2 PPI. First, we built a SBP model based on p53-MDM2 complex cocrystal structures. The model was then simplified by using a Receptor-Ligand complex-based pharmacophore model considering the critical binding features between MDM2 and its small molecular inhibitors. Cascade docking was subsequently applied to improve the hit rate. Based on this strategy, we performed VS on NCI and SPECS databases and successfully discovered 6 novel compounds from 15 hits with the best, compound 1 (NSC 5359), K(i) = 180 ± 50 nM. These compounds can serve as lead compounds for further optimization.

MEMS deformable mirror embedded wavefront sensing and control system

NASA Astrophysics Data System (ADS)

Owens, Donald; Schoen, Michael; Bush, Keith

2006-01-01

Electrostatic Membrane Deformable Mirror (MDM) technology developed using silicon bulk micro-machining techniques offers the potential of providing low-cost, compact wavefront control systems for diverse optical system applications. Electrostatic mirror construction using bulk micro-machining allows for custom designs to satisfy wavefront control requirements for most optical systems. An electrostatic MDM consists of a thin membrane, generally with a thin metal or multi-layer high-reflectivity coating, suspended over an actuator pad array that is connected to a high-voltage driver. Voltages applied to the array elements deflect the membrane to provide an optical surface capable of correcting for measured optical aberrations in a given system. Electrostatic membrane DM designs are derived from well-known principles of membrane mechanics and electrostatics, the desired optical wavefront control requirements, and the current limitations of mirror fabrication and actuator drive electronics. MDM performance is strongly dependent on mirror diameter and air damping in meeting desired spatial and temporal frequency requirements. In this paper, we present wavefront control results from an embedded wavefront control system developed around a commercially available high-speed camera and an AgilOptics Unifi MDM driver using USB 2.0 communications and the Linux development environment. This new product, ClariFast TM, combines our previous Clarifi TM product offering into a faster more streamlined version dedicated strictly to Hartmann Wavefront sensing.

Adherent Human Alveolar Macrophages Exhibit a Transient Pro-Inflammatory Profile That Confounds Responses to Innate Immune Stimulation

PubMed Central

Tomlinson, Gillian S.; Booth, Helen; Petit, Sarah J.; Potton, Elspeth; Towers, Greg J.; Miller, Robert F.; Chain, Benjamin M.; Noursadeghi, Mahdad

2012-01-01

Alveolar macrophages (AM) are thought to have a key role in the immunopathogenesis of respiratory diseases. We sought to test the hypothesis that human AM exhibit an anti-inflammatory bias by making genome-wide comparisons with monocyte derived macrophages (MDM). Adherent AM obtained by bronchoalveolar lavage of patients under investigation for haemoptysis, but found to have no respiratory pathology, were compared to MDM from healthy volunteers by whole genome transcriptional profiling before and after innate immune stimulation. We found that freshly isolated AM exhibited a marked pro-inflammatory transcriptional signature. High levels of basal pro-inflammatory gene expression gave the impression of attenuated responses to lipopolysaccharide (LPS) and the RNA analogue, poly IC, but in rested cells pro-inflammatory gene expression declined and transcriptional responsiveness to these stimuli was restored. In comparison to MDM, both freshly isolated and rested AM showed upregulation of MHC class II molecules. In most experimental paradigms ex vivo adherent AM are used immediately after isolation. Therefore, the confounding effects of their pro-inflammatory profile at baseline need careful consideration. Moreover, despite the prevailing view that AM have an anti-inflammatory bias, our data clearly show that they can adopt a striking pro-inflammatory phenotype, and may have greater capacity for presentation of exogenous antigens than MDM. PMID:22768282

Guide to listing references.

DOT National Transportation Integrated Search

2005-01-01

The introduction of listing references. It introduces the reference of printed sources, CD-ROMs, websites, unpublished papers and program manuals, tapes, or other documentation for models. Meanwhile, it describes some examples to use Chicago Manual o...

[Selected aspects of computer-assisted literature management].

PubMed

Reiss, M; Reiss, G

1998-01-01

We want to report about our own experiences with a database manager. Bibliography database managers are used to manage information resources: specifically, to maintain a database to references and create bibliographies and reference lists for written works. A database manager allows to enter summary information (record) for articles, book sections, books, dissertations, conference proceedings, and so on. Other features that may be included in a database manager include the ability to import references from different sources, such as MEDLINE. The word processing components allow to generate reference list and bibliographies in a variety of different styles, generates a reference list from a word processor manuscript. The function and the use of the software package EndNote 2 for Windows are described. Its advantages in fulfilling different requirements for the citation style and the sort order of reference lists are emphasized.

30 CFR 285.115 - Documents incorporated by reference.

Code of Federal Regulations, 2011 CFR

2011-07-01

... incorporating by reference the documents listed in the table in paragraph (e) of this section. The Director of...: ER29AP09.104 (e) This paragraph lists documents incorporated by reference. To easily reference text of the... 30 Mineral Resources 2 2011-07-01 2011-07-01 false Documents incorporated by reference. 285.115...

Flight dynamics analysis and simulation of heavy lift airships. Volume 5: Programmer's manual

NASA Technical Reports Server (NTRS)

Ringland, R. F.; Tischler, M. B.; Jex, H. R.; Emmen, R. D.; Ashkenas, I. L.

1982-01-01

The Programmer's Manual contains explanations of the logic embodied in the various program modules, a dictionary of program variables, a subroutine listing, subroutine/common block/cross reference listing, and a calling/called subroutine cross reference listing.

PLC-based mode multi/demultiplexer for MDM transmission

NASA Astrophysics Data System (ADS)

Hanzawa, N.; Saitoh, K.; Sakamoto, T.; Matsui, T.; Tsujikawa, K.; Koshiba, M.; Yamamoto, F.

2013-12-01

We propose a PLC-based multi/demultiplexer (MUX/DEMUX) with a mode conversion function for mode division multiplexing (MDM) transmission applications. The PLC-based mode MUX/DEMUX can realize a low insertion loss and a wide working wavelength bandwidth. We designed and demonstrated a two-mode (LP01 and LP11 modes) and a three-mode (LP01, LP11, and LP21 modes) MUX/DEMUX for use in the C-band.

Orbiter multiplexer-demultiplexer (MDM)/Space Lab Bus Interface Unit (SL/BIU) serial data interface evaluation, volume 2

NASA Technical Reports Server (NTRS)

Tobey, G. L.

1978-01-01

Tests were performed to evaluate the operating characteristics of the interface between the Space Lab Bus Interface Unit (SL/BIU) and the Orbiter Multiplexer-Demultiplexer (MDM) serial data input-output (SIO) module. This volume contains the test equipment preparation procedures and a detailed description of the Nova/Input Output Processor Simulator (IOPS) software used during the data transfer tests to determine word error rates (WER).

Millicharge or decay: a critical take on Minimal Dark Matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nobile, Eugenio Del; Dipartimento di Fisica e Astronomia “G. Galilei”, Università di Padova and INFN, Sezione di Padova,Via Marzolo 8, 35131 Padova; Nardecchia, Marco

2016-04-26

Minimal Dark Matter (MDM) is a theoretical framework highly appreciated for its minimality and yet its predictivity. Of the two only viable candidates singled out in the original analysis, the scalar eptaplet has been found to decay too quickly to be around today, while the fermionic quintuplet is now being probed by indirect Dark Matter (DM) searches. It is therefore timely to critically review the MDM paradigm, possibly pointing out generalizations of this framework. We propose and explore two distinct directions. One is to abandon the assumption of DM electric neutrality in favor of absolutely stable, millicharged DM candidates whichmore » are part of SU(2){sub L} multiplets with integer isospin. Another possibility is to lower the cutoff of the model, which was originally fixed at the Planck scale, to allow for DM decays. We find new viable MDM candidates and study their phenomenology in detail.« less

Serum Metal Ion Levels Following Total Hip Arthroplasty With Modular Dual Mobility Components.

PubMed

Matsen Ko, Laura J; Pollag, Kimberley E; Yoo, Joanne Y; Sharkey, Peter F

2016-01-01

Dual mobility acetabular components can reduce the incidence of total hip arthroplasty (THA) instability. Modular dual mobility (MDM) components facilitate acetabular component implantation. However, corrosion can occur at modular junctions. Serum cobalt and chromium levels and Oxford scores were obtained at minimum two year follow-up for 100 consecutive patients who had THA with MDM components. Average Oxford score was 43 (range 13-48). Average serum cobalt and chromium values were 0.7 mcg/L (range, 0.0 to 7.0) and 0.6 mcg/L (range, 0.1 to 2.7), respectively. MARS MRI was performed for four patients with pain and elevated serum cobalt levels. Two of these studies were consistent with adverse local tissue reaction. We recommend use of MDM implants in only patients at high risk for dislocation following THA. Copyright © 2016 Elsevier Inc. All rights reserved.

Directional Emission from Metal-Dielectric-Metal Structures: Effect of Mixed Metal Layers, Dye Location and Dielectric Thickness.

PubMed

Choudhury, Sharmistha Dutta; Badugu, Ramachandram; Ray, Krishanu; Lakowicz, Joseph R

2015-02-12

Metal-dielectric-metal (MDM) structures provide directional emission close to the surface normal, which offers opportunities for new design formats in fluorescence based applications. The directional emission arises due to near-field coupling of fluorophores with the optical modes present in the MDM substrate. Reflectivity simulations and dispersion diagrams provide a basic understanding of the mode profiles and the factors that affect the coupling efficiency and the spatial distribution of the coupled emission. This work reveals that the composition of the metal layers, the location of the dye in the MDM substrate and the dielectric thickness are important parameters that can be chosen to tune the color of the emission wavelength, the angle of observation, the angular divergence of the emission and the polarization of the emitted light. These features are valuable for displays and optical signage.

Directional Emission from Metal-Dielectric-Metal Structures: Effect of Mixed Metal Layers, Dye Location and Dielectric Thickness

PubMed Central

Choudhury, Sharmistha Dutta; Badugu, Ramachandram; Ray, Krishanu; Lakowicz, Joseph R.

2015-01-01

Metal-dielectric-metal (MDM) structures provide directional emission close to the surface normal, which offers opportunities for new design formats in fluorescence based applications. The directional emission arises due to near-field coupling of fluorophores with the optical modes present in the MDM substrate. Reflectivity simulations and dispersion diagrams provide a basic understanding of the mode profiles and the factors that affect the coupling efficiency and the spatial distribution of the coupled emission. This work reveals that the composition of the metal layers, the location of the dye in the MDM substrate and the dielectric thickness are important parameters that can be chosen to tune the color of the emission wavelength, the angle of observation, the angular divergence of the emission and the polarization of the emitted light. These features are valuable for displays and optical signage. PMID:25844110

Selective excitation of LG 00, LG 01, and LG 02 modes by a solid core PCF based mode selector in MDM-Ro-FSO transmission systems

NASA Astrophysics Data System (ADS)

Chaudhary, Sushank; Amphawan, Angela

2018-07-01

Radio over free space (Ro-FSO) provides an ambitious platform for seamless integration of radio networks to optical networks. Three independent channels, each carrying 2.5 Gbps–5 GHz data, are successfully transmitted over a free space link of 2.5 km by using mode division multiplexing (MDM) of three modes LG 00, LG 01, and LG 02 modes in conjunction with solid core photonic crystal fibers (SC-PCFs). Moreover, SC-PCFs are used as a mode selector in the proposed MDM-Ro-FSO system. The results are reported in terms of bit error rate, mode spectrum, and spatial profiles. The performance of the proposed Ro-FSO system is also evaluated under the influence of atmospheric turbulence in the form of different levels of fog, namely, light fog, thin fog, and heavy fog.

Rare Aggressive Behavior of MDM2-Amplified Retroperitoneal Dedifferentiated Liposarcoma, with Brain, Lung and Subcutaneous Metastases.

PubMed

Ben Salha, Imen; Zaidi, Shane; Noujaim, Jonathan; Miah, Aisha B; Fisher, Cyril; Jones, Robin L; Thway, Khin

2016-09-05

Dedifferentiated liposarcoma (DDL) is a histologically pleomorphic sarcoma, traditionally defined as well-differentiated liposarcoma with abrupt transition to high grade, non-lipogenic sarcoma. It can occur as part of recurrent well-differentiated liposarcoma, or may arise de novo . DDL most frequently occurs within the retroperitoneum, and while it is prone to local recurrence, it usually has a lower rate of metastasis than other pleomorphic sarcomas. We describe a case of retroperitoneal dedifferentiated liposarcoma in a 63-year-old male, who showed MDM2 amplification with fluorescence in situ hybridization, which displayed unusually aggressive behavior, with brain, lung and subcutaneous soft tissue metastases. As previous reports of metastatic liposarcoma have largely grouped DDL in with other (genetically and clinically distinct) liposarcoma subtypes, we highlight and discuss the rare occurrence of brain metastasis in MDM2 -amplified retroperitoneal liposarcoma.

Millicharge or decay: a critical take on Minimal Dark Matter

DOE PAGES

Nobile, Eugenio Del; Nardecchia, Marco; Panci, Paolo

2016-04-26

Minimal Dark Matter (MDM) is a theoretical framework highly appreciated for its minimality and yet its predictivity. Of the two only viable candidates singled out in the original analysis, the scalar eptaplet has been found to decay too quickly to be around today, while the fermionic quintuplet is now being probed by indirect Dark Matter (DM) searches. It is therefore timely to critically review the MDM paradigm, possibly pointing out generalizations of this framework. We propose and explore two distinct directions. One is to abandon the assumption of DM electric neutrality in favor of absolutely stable, millicharged DM candidates whichmore » are part of SU(2)L multiplets with integer isospin. Another possibility is to lower the cutoff of the model, which was originally fixed at the Planck scale, to allow for DM decays. We find new viable MDM candidates and study their phenomenology in detail.« less

Manual search approaches used by systematic reviewers in dermatology.

PubMed

Vassar, Matt; Atakpo, Paul; Kash, Melissa J

2016-10-01

Manual searches are supplemental approaches to database searches to identify additional primary studies for systematic reviews. The authors argue that these manual approaches, in particular hand-searching and perusing reference lists, are often considered the same yet lead to different outcomes. We conducted a PubMed search for systematic reviews in the top 10 dermatology journals (January 2006-January 2016). After screening, the final sample comprised 292 reviews. Statements related to manual searches were extracted from each review and categorized by the primary and secondary authors. Each statement was categorized as either "Search of Reference List," "Hand Search," "Both," or "Unclear." Of the 292 systematic reviews included in our sample, 143 reviews (48.97%) did not report a hand-search or scan of reference lists. One-hundred thirty-six reviews (46.58%) reported searches of reference lists, while 4 reviews (1.37%) reported systematic hand-searches. Three reviews (1.03%) reported use of both hand-searches and scanning reference lists. Six reviews (2.05%) were classified as unclear due to vague wording. Authors of systematic reviews published in dermatology journals in our study sample scanned reference lists more frequently than they conducted hand-searches, possibly contributing to biased search outcomes. We encourage systematic reviewers to routinely practice hand-searching in order to minimize bias.

Dedifferentiated liposarcoma and pleomorphic liposarcoma: a comparative study of cytomorphology and MDM2/CDK4 expression on fine-needle aspiration.

PubMed

Mariño-Enríquez, Adrián; Hornick, Jason L; Dal Cin, Paola; Cibas, Edmund S; Qian, Xiaohua

2014-02-01

Dedifferentiated liposarcoma (DDLPS) and pleomorphic liposarcoma (PLPS) are distinct high-grade liposarcomas. DDLPS is a nonlipogenic sarcoma characterized by amplification of MDM2 and CDK4. PLPS is a high-grade sarcoma containing lipoblasts, characterized by a complex karyotype and a more aggressive clinical course. Rarely, DDLPS shows lipogenic differentiation, mimicking PLPS. The cytomorphologic features of DDLPS and PLPS and the utility of ancillary studies have not been systemically analyzed. Cytologic preparations of 25 DDLPS and 13 PLPS, all histologically confirmed, were retrospectively reviewed along with clinical and cytogenetic data. Sample cellularity, vascular architecture, background material, predominant cell morphology, quality of the cytoplasm, and nuclear pleomorphism were compared for both tumor types. Immunohistochemistry for MDM2 and CDK4 was performed on cell blocks and/or core needle biopsies. Fine-needle aspirate smears from both DDLPS and PLPS were variably cellular, composed of cellular clusters and noncohesive cells. Abundant myxoid stroma was present in ∼25% of DDLPS and PLPS cases, whereas branching curvilinear vessels were more common in DDLPS than in PLPS (7 of 25 versus 2 of 13). Tumors were composed of predominantly spindled (18 of 25 DDLPS versus 3 of 13 PLPS) or epithelioid cells (7 of 25 DDLPS versus 6 of 13 PLPS). Pleomorphic cells were predominant in 3 PLPS, and were frequent in both (13 of 25 DDLPS versus 10 of 13 PLPS). The cytoplasm was mostly fibrillary and often vacuolated in both entities. Other features included necrosis, mitoses, and a prominent inflammatory infiltrate. The main cytologic differences were the presence of marked pleomorphism, abundant lipoblasts, and cells with microvacuolated cytoplasm in most PLPS. A total of 24 (96%) and 20 (80%) cases of DDLPS expressed MDM2 and CDK4, respectively, whereas none of the PLPS expressed both markers. Six DDLPS tested showed ring or giant marker chromosomes and/or MDM2 amplification by fluorescence in situ hybridization; 2 PLPS had complex karyotypes. DDLPS and PLPS exhibit variable and occasionally overlapping cytologic features. The presence of lipoblasts, cells with microvacuolated cytoplasm, and marked pleomorphism are more suggestive of PLPS, but these characteristics can be present in DDLPS. Coexpression of MDM2 and CDK4 distinguishes DDLPS from PLPS. © 2013 American Cancer Society.

MEKK1 is a Novel Regulator of the Dmp1-Arf-p53 Pathway and Prognostic Indicator in Breast Cancer

DTIC Science & Technology

2012-12-01

hDMP1, INK4a/ARF, p53 or Hdm2 amplification. Kaplan -Meier analyses have been conducted to study the impact for the impact of loss or gain of each locus on...Palma P, Pellegrini S, Fina P et al. Mdm2 gene alterations and mdm2 protein expression in breast carcinomas. J Pathol 1995; 175: 31–38. 21 Turbin DA

Assessment of mdm2 Alterations on p53 Expression in Breast Cancer

DTIC Science & Technology

2000-10-01

Figure 2. Schematic Comparison of mdm2 with PCR Products of Various Sizes. nuclear localization signal I p53 binding site X acidic domain zinc...susceptibility gene isolated by controlled homozygous functional knockout of allelic loci in mammalian cells. Cell. 85: 319-329, 1996. 36. Li, L., Li, X ...twelve years. Chinese Journal of Parasitology and Parasitic Diseases 10: 112-114, 1992. 7. Gao DQ, Cansesaa L, Mouradian MM, Jose P. Dopamine D2-long

Regulation of MDM2 Activity by Nucleolin

DTIC Science & Technology

2007-06-01

protein also able to bind and inhibit ARF (Itahana et al., 2003; Bertwistle et al., 2004; Korgaonkar et al., 2005). A role for the nucleolus in the...found to sequester Mdm2 in the nucleolus (Weber et al., 1999), although this activity does not appear to be requisite for ARF-dependent p53 stabilization...from the nucleolus to the nucleoplasm in a reaction stimulated by physical interaction with p53, but independent of the ability of p53 to activate

The pre-existing population of 5S rRNA effects p53 stabilization during ribosome biogenesis inhibition.

PubMed

Onofrillo, Carmine; Galbiati, Alice; Montanaro, Lorenzo; Derenzini, Massimo

2017-01-17

Pre-ribosomal complex RPL5/RPL11/5S rRNA (5S RNP) is considered the central MDM2 inhibitory complex that control p53 stabilization during ribosome biogenesis inhibition. Despite its role is well defined, the dynamic of 5S RNP assembly still requires further characterization. In the present work, we report that MDM2 inhibition is dependent by a pre-existing population of 5S rRNA.

Polymorphisms in xenobiotic metabolizing genes, intakes of heterocyclic amines and red meat, and postmenopausal breast cancer

PubMed Central

Lee, Hae-Jeung; Wu, Kana; Cox, David G.; Hunter, David; Hankinson, Susan E.; Willett, Walter C.; Sinha, Rashmi; Cho, Eunyoung

2013-01-01

Heterocyclic amines (HCAs) are mutagenic compounds generated when meats are cooked at high temperature and for long duration. The findings from previous studies on the relation between HCAs and breast cancer are inconsistent, possibly due to genetic variations in the enzymes metabolizing HCAs. To evaluate whether the associations of intakes of estimated HCAs, meat-derived mutagenicity (MDM), and red meat with risk of postmenopausal breast cancer were modified by N-acetyltransferase 2 (NAT2) acetylator genotype or cytochrome P450 1A2 -164 A/C (CYP1A2) polymorphism, we conducted a nested case-control study with 579 cases and 981 controls within a prospective cohort, the Nurses’ Health Study (NHS). HCAs and MDM intakes were derived using a cooking method questionnaire administered in 1996. NAT2 acetylator genotype, the CYP1A2 polymorphism, and intakes of HCAs, MDM, and red meat were not associated with risk of postmenopausal breast cancer. There was also no interaction between NAT2 acetylator genotype or CYP1A2 polymorphism and HCAs and MDM and red meat intake in relation to breast cancer. These results do not support the hypothesis that genetic polymorphisms of xenobiotic enzymes involved in the metabolism of HCAs may modify the associations between intakes of red meat or meat-related mutagens and breast cancer risk. PMID:24099317

Dedifferentiated liposarcoma with meningothelial-like whorls, metaplastic bone formation, and CDK4, MDM2, and p16 expression: a morphologic and immunohistochemical study.

PubMed

Thway, Khin; Robertson, David; Thway, Yi; Fisher, Cyril

2011-03-01

We studied 5 cases of dedifferentiated liposarcoma with meningothelial-like whorls and metaplastic bone formation, assessing morphology and immunohistochemical expression of a panel of antigens (CDK4, MDM2, and p16 proteins, desmin, smooth muscle actin, h-caldesmon, CD34, AE1/AE3, epithelial membrane antigen, claudin-1, S100 protein, CD21, CD35, CD117, β-catenin, vimentin, and MIB1). The specimens were from the retroperitoneum (3), pelvis (1) or paratesticular region (1), and all 5 specimens comprised exclusively or predominantly dedifferentiated liposarcoma. All 5 dedifferentiated liposarcomas showed prominent metaplastic bone, 3 produced cartilage, and 1 also had osteosarcomatous tissue. The whorls comprised concentric distributions of spindle or epithelioid cells. All cases expressed smooth muscle actin, 3 strongly, whereas 4 cases showed at least focal claudin-1 positivity. In all cases, the whorls expressed at least 2 of CDK4, MDM2, and p16. The presence of 2 morphologic subsets and the immunohistochemical findings suggest that the whorls in these dedifferentiated liposarcomas exhibit divergent myofibroblastic and possibly perineurial differentiation. The CDK4, MDM2, and p16 expression in the whorls suggests that they share a similar genetic background to well-differentiated and dedifferentiated liposarcoma, and that additional genetic events are causal to their distinct morphology.

The expression of COX-2, hTERT, MDM2, LATS2 and S100A2 in different types of non-small cell lung cancer (NSCLC).

PubMed

Strazisar, Mojca; Mlakar, Vid; Glavac, Damjan

2009-01-01

Several studies have reported different expression levels of certain genes in NSCLC, mostly related to the stage and advancement of the tumours. We investigated 65 stage I-III NSCLC tumours: 32 adenocarcinomas (ADC), 26 squamous cell carcinomas (SCC) and 7 large cell carcinomas (LCC). Using the real-time reverse transcription polymerase chain reaction (RT-PCR), we analysed the expression of the COX-2, hTERT, MDM2, LATS2 and S100A2 genes and researched the relationships between the NSCLC types and the differences in expression levels. The differences in the expression levels of the LATS2, S100A2 and hTERT genes in different types of NSCLC are significant. hTERT and COX-2 were over-expressed and LATS2 under-expressed in all NSCLC. We also detected significant relative differences in the expression of LATS2 and MDM2, hTERT and MDM2 in different types of NSCLC. There was a significant difference in the average expression levels in S100A2 for ADC and SCC. Our study shows differences in the expression patterns within the NSCLC group, which may mimic the expression of the individual NSCLC type, and also new relationships in the expression levels for different NSCLC types.

Selective increase in the association of the β2 adrenergic receptor, β Arrestin-1 and p53 with Mdm2 in the ventral hippocampus one month after underwater trauma.

PubMed

Sood, Rapita; Ritov, Gilad; Richter-Levin, Gal; Barki-Harrington, Liza

2013-03-01

Chronic infusion of mice with a β2 adrenergic receptor (β2AR) analog was shown to cause long-term DNA damage in a pathway which involves β Arresin-1-mediated activation of Mdm2 and subsequent degradation of the tumor suppressor protein p53. The objective of the present study was to test whether a single acute stress, which manifests long lasting changes in behavior, affects the interaction of Mdm2 with p53, β2AR, and β Arrestin-1 in the dorsal and ventral hippocampal CA1. Adult rats were subject to underwater trauma, a brief forceful submersion under water and tested a month later for behavioral and biochemical changes. Elevated plus maze tests confirmed that animals that experienced the threat of drowning present heightened levels of anxiety one month after trauma. An examination of the CA1 hippocampal areas of the same rats showed that underwater trauma caused a significant increase in the association of Mdm2 with β2AR, β Arrestin-1, and p53 in the ventral but not dorsal CA1. Our results provide support for the idea that stress-related events may result in biochemical changes restricted to the ventral 'emotion-related' parts of the hippocampus. Copyright © 2012 Elsevier B.V. All rights reserved.

Double-edged swords as cancer therapeutics: novel, orally active, small molecules simultaneously inhibit p53-MDM2 interaction and the NF-κB pathway.

PubMed

Zhuang, Chunlin; Miao, Zhenyuan; Wu, Yuelin; Guo, Zizhao; Li, Jin; Yao, Jianzhong; Xing, Chengguo; Sheng, Chunquan; Zhang, Wannian

2014-02-13

Simultaneous inactivation of p53 and hyperactivation of nuclear factor-κB (NF-κB) is a common occurrence in human cancer. Currently, antitumor agents are being designed to selectively activate p53 or inhibit NF-κB. However, there is no concerted effort yet to deliberately design inhibitors that can simultaneously do both. This paper provided a proof-of-concept study that p53-MDM2 interaction and NF-κB pathway can be simultaneously targeted by a small-molecule inhibitor. A series of pyrrolo[3,4-c]pyrazole derivatives were rationally designed and synthesized as the first-in-class inhibitors of p53-MDM2 interaction and NF-κB pathway. Most of the compounds were identified to possess nanomolar p53-MDM2 inhibitory activity. Compounds 5q and 5s suppressed NF-κB activation through inhibition of IκBα phosphorylation and elevation of the cytoplasmic levels of p65 and phosphorylated IKKα/β. Biochemical assay for the kinases also supported the fact that pyrrolo[3,4-c]pyrazole compounds directly targeted the NF-κB pathway. In addition, four compounds (5j, 5q, 5s, and 5u) effectively inhibited tumor growth in the A549 xenograft model. Further pharmacokinetic study revealed that compound 5q exhibited excellent oral bioavailability (72.9%).

Zinc Oxide Nanoparticles Demoted MDM2 Expression to Suppress TSLP-Induced Mast Cell Proliferation.

PubMed

Kim, Min-Ho; Jeong, Hyun-Ja

2016-03-01

Activation of murine double minute 2 (MDM2) through thymic stromal lymphopoietin (TSLP)-induced signal transducers and activators of transcription (STAT6) phosphorylation plays a critical role in proliferation and survival of mast cells. Previously, we reported that zinc oxide nanoparticles (ZnO-NP) effectively decrease the mast cell-mediated allergic inflammatory reactions. Here, we evaluated the effect of ZnO-NP on TSLP-induced proliferation of mast cells. ZnO-NP significantly reduced the number of BrdU-incorporating mast cells increased by TSLP. ZnO-NP decreased the expression of MDM2 through the blockade of STAT6 phosphorylation. TSLP increased the production and mRNA expression of interleukin-13 (a growth factor of mast cells), its increase was significantly decreased by ZnO-NP (10 μg/mL). ZnO-NP induced the down-regulation of Bcl2 (an anti-apoptotic factor) and up-regulation of Bax (an apoptotic factor) through the stabilization of p53 protein. However, ZnO-NP has no effect on caspase-3 activation, cytochrome c release into cytosol, and apoptosis-inducing factor translocation into nucleus in TSLP-stimulated cells. The results of the present study demonstrated that ZnO-NP inhibited the proliferation of mast cells through the regulation of MDM2 and p53 protein levels. These finding suggest that ZnO-NP could be improved mast cell-mediated various diseases.

Compatibility of a dark matter discovery at XENONnT or LZ with the WIMP thermal production mechanism

NASA Astrophysics Data System (ADS)

Catena, Riccardo; Conrad, Jan; Krauss, Martin B.

2018-05-01

The discovery of dark matter (DM) at XENONnT or LZ would place constraints on DM particle mass and coupling constants. It is interesting to ask when these constraints can be compatible with the DM thermal production mechanism. We address this question within the most general set of renormalizable models that preserve Lorentz and gauge symmetry, and that extend the standard model by one DM candidate of mass mDM and one particle of mass Mmed mediating DM-quark interactions. Our analysis divides into two parts. First, we postulate that XENONnT/LZ has detected μS˜O (100 ) signal events, and use this input to calculate the DM relic density, ΩDMh2. Then, we identify the regions in the Mmed-ΩDMh2 plane which are compatible with the observed signal and with current CMB data. We find that for most of the models considered here, O (100 ) signal events at XENONnT/LZ and the DM thermal production are only compatible for resonant DM annihilations, i.e. for Mmed≃2 mDM. In this case, XENONnT/LZ would be able to simultaneously measure mDM and Mmed. We also discuss the dependence of our results on mDM, μS and the DM spin, and provide analytic expressions for annihilation cross sections and mediator decay widths for all models considered in this study.

RADIOISOTOPES IN MEDICINE AND HUMAN PHYSIOLOGY. A Selected List of References

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCormick, J.A. comp.

1958-08-01

This bibliography contains 2862 references on uses of radioisotopes in diagnostic medicine, therapeutic medicine, clinical research, human physiology, general medical research, and immunology. The references were taken from the 1948 to 1956 open literature. A list of the journals from which the references were selected and an author index are included. (auth)'

Libraries & Study Facilities. A Selected Bibliography.

ERIC Educational Resources Information Center

Wisconsin Univ., Madison. ERIC Clearinghouse on Educational Facilities.

This bibliography contains a selected reference list of publications of interest to architects, library planners, and librarians contemplating the planning, programing, and/or design of library facilities. Each reference is followed by a listing of ERIC descriptors that describe its contents. The items are listed in six sections: (1) library…

Biotechnology: Applications in Agriculture. Instructor Guide [and] Student Reference.

ERIC Educational Resources Information Center

Nevils, Aaron

This curriculum guide incorporates the needed components to aid agriculture teachers in the implementation of the Vocational Instructional Management System in biotechnology: applications in agriculture. The guide begins with a list of the competencies/objectives found in the six units; list of references and materials; list of materials and…

Meat mutagens and breast cancer in postmenopausal women -a cohort analysis

PubMed Central

Wu, Kana; Sinha, Rashmi; Holmes, Michelle D.; Giovannucci, Edward; Willett, Walter; Cho, Eunyoung

2011-01-01

Background Mutagenic compounds produced when meats are cooked at high temperatures have been hypothesized to increase risk of breast cancer. Methods We examined the association between intakes of the heterocyclic amines (HCAs) MeIQx (2-amino-3,8-dimethylimidazo (4,5,-f) quinoxaline), PhIP (2-amino-1-methyl-6-phenylimidazo (4,5-b) pyridine), DiMeIQx (2-amino-3,4,8-trimethylimidazo (4,5,-f)) and meat-derived mutagenic activity (MDM) and risk of breast cancer using a cooking method questionnaire administered in 1996 in the Nurses Health Study. Between 1996 and 2006, 2,317 breast cancer cases were diagnosed during 533,618 person years. Results Higher intake of HCAs or MDM was not associated with elevated risk of breast cancer (multivariate relative risk (RR) and 95% confidence interval (95% CI) for the highest vs. lowest quintile: MeIQx: 0.90 (0.79–1.03); PhIP: 0.92 (0.80–1.05); DiMeIQx: 0.92 (0.80–1.05) and MDM: 0.98 (0.85–1.12)). HCA or MDM were not associated with estrogen receptor positive/progesterone positive breast cancer risk either. There was some suggestion of a decreased risk of estrogen receptor negative/progesterone receptor negative breast cancer with higher intakes of MeIQx, DiMeIQx and PhIP, but none of the associations were statistically significant. There was little evidence for an interaction between intake of cruciferous vegetables and HCA or MDM intake and risk of breast cancer. Conclusion Higher consumption of mutagens from meats cooked at higher temperature and longer duration was not associated with increased risk of postmenopausal breast cancer. Impact Overall prospective data including results from our study do not provide support for a substantial increase in risk of breast cancer with higher intake of HCAs. PMID:20447922

Hyperprogressors after Immunotherapy: Analysis of Genomic Alterations Associated with Accelerated Growth Rate.

PubMed

Kato, Shumei; Goodman, Aaron; Walavalkar, Vighnesh; Barkauskas, Donald A; Sharabi, Andrew; Kurzrock, Razelle

2017-08-01

Purpose: Checkpoint inhibitors demonstrate salutary anticancer effects, including long-term remissions. PD-L1 expression/amplification, high mutational burden, and mismatch repair deficiency correlate with response. We have, however, observed a subset of patients who appear to be "hyperprogressors," with a greatly accelerated rate of tumor growth and clinical deterioration compared with pretherapy, which was also recently reported by Institut Gustave Roussy. The current study investigated potential genomic markers associated with "hyperprogression" after immunotherapy. Experimental Design: Consecutive stage IV cancer patients who received immunotherapies (CTLA-4, PD-1/PD-L1 inhibitors or other [investigational] agents) and had their tumor evaluated by next-generation sequencing were analyzed ( N = 155). We defined hyperprogression as time-to-treatment failure (TTF) <2 months, >50% increase in tumor burden compared with preimmunotherapy imaging, and >2-fold increase in progression pace. Results: Amongst 155 patients, TTF <2 months was seen in all six individuals with MDM2/MDM4 amplification. After anti-PD1/PDL1 monotherapy, four of these patients showed remarkable increases in existing tumor size (55% to 258%), new large masses, and significantly accelerated progression pace (2.3-, 7.1-, 7.2- and 42.3-fold compared with the 2 months before immunotherapy). In multivariate analysis, MDM2/MDM4 and EGFR alterations correlated with TTF <2 months. Two of 10 patients with EGFR alterations were also hyperprogressors (53.6% and 125% increase in tumor size; 35.7- and 41.7-fold increase). Conclusions: Some patients with MDM2 family amplification or EGFR aberrations had poor clinical outcome and significantly increased rate of tumor growth after single-agent checkpoint (PD-1/PD-L1) inhibitors. Genomic profiles may help to identify patients at risk for hyperprogression on immunotherapy. Further investigation is urgently needed. Clin Cancer Res; 23(15); 4242-50. ©2017 AACR . ©2017 American Association for Cancer Research.

MDM2 promoter polymorphism and p53 codon 72 polymorphism in chronic myeloid leukemia: the association between MDM2 promoter genotype and disease susceptibility, age of onset, and blast-free survival in chronic phase patients receiving imatinib.

PubMed

Liu, Yi-Chang; Hsiao, Hui-Hua; Yang, Wen-Chi; Liu, Ta-Chih; Chang, Chao-Sung; Yang, Ming-Yu; Lin, Pai-Mei; Hsu, Jui-Feng; Lee, Ching-Ping; Lin, Sheng-Fung

2014-12-01

The genetic or functional inactivation of the p53 pathway plays an important role with regards to disease progression from the chronic phase (CP) to blast phase (BP) and imatinib treatment response in chronic myeloid leukemia (CML). Two functional single nucleotide polymorphisms (SNPs), p53 R72P and MDM2 SNP309, are associated with alternation of p53 activity, however the association regarding CML susceptibility and BP transformation under imatinib treatment is unclear. The MDM2 SNP309 genotype was determined by polymerase chain reaction-restriction fragment length polymorphism and confirmed by direct sequencing from 116 CML patients, including 104 in the CP at diagnosis, and 162 healthy Taiwanese controls. The p53 R72P polymorphism was examined in all CML patients. The SNP309 G/G genotype was associated with an increased risk of CML susceptibility (OR: 1.82, 95% CI: 1.03-3.22, P = 0.037), and an earlier age of disease onset (log-rank P = 0.005) compared with the T/T + T/G genotypes. Higher MDM2 mRNA expression was found in G/G genotype compared with T/T (P = 0.034) and T/T + T/G (P = 0.056) genotypes. No associations were found between the p53 R72P genotypes and clinical parameters and survival outcomes. Among 62 CP patients receiving imatinib as first-line therapy, the G/G genotype was associated with a shorter blast-free survival (log-rank P = 0.048) and more clonal evolution compared with the T/T + T/G genotypes. In patients with advanced diseases at diagnosis, the G/G genotype was associated with a poor overall survival (log-rank P = 0.006). Closely monitoring CML patients harboring the G/G genotype and further large-scale studies are warranted. © 2013 Wiley Periodicals, Inc.

Macrophages are related to goblet cell hyperplasia and induce MUC5B but not MUC5AC in human bronchus epithelial cells.

PubMed

Silva, Manuel A; Bercik, Premysl

2012-06-01

Airway goblet cell hyperplasia (GCH)--detectable by mucin staining--and abnormal macrophage infiltrate are pathological features present in many chronic respiratory disorders. However, it is unknown if both factors are associated. Using in-vivo and in-vitro models, we investigated whether macrophages are related with GCH and changes in mucin immunophenotypes. Lung sections from Sprague-Dawley rats treated for 48 h with one intra-tracheal dose of PBS or LPS (n=4-6 per group) were immunophenotyped for rat-goblet cells, immune, and proliferation markers. Human monocyte-derived macrophages (MDM) were pre-treated with or without LPS, immunophenotyped, and their supernatant, as well as cytokines at levels equivalent to supernatant were used to challenge primary culture of normal human bronchus epithelial cells (HBEC) in air-liquid interface, followed by MUC5B and MUC5AC mucin immunostaining. An association between increased bronchiolar goblet cells and terminal-bronchiolar proliferative epithelial cells confirmed the presence of GCH in our LPS rat model, which was related with augmented bronchiolar CD68 macrophage infiltration. The in-vitro experiments have shown that MUC5AC phenotype was inhibited when HBEC were challenged with supernatant from MDM pre-treated with or without LPS. In contrast, TNF-α and interleukin-1β at levels equivalent to supernatant from LPS-treated MDM increased MUC5AC. MUC5B was induced by LPS, supernatant from LPS-treated MDM, a mix of cytokines including TNF-α and TNF-α alone at levels present in supernatant from LPS-treated MDM. We demonstrated that macrophages are related with bronchiolar GCH, and that they induced MUC5B and inhibited MUC5AC in HBEC, suggesting a role for them in the pathogenesis of airway MUC5B-related GCH.

Computational Framework for Prediction of Peptide Sequences That May Mediate Multiple Protein Interactions in Cancer-Associated Hub Proteins.

PubMed

Sarkar, Debasree; Patra, Piya; Ghosh, Abhirupa; Saha, Sudipto

2016-01-01

A considerable proportion of protein-protein interactions (PPIs) in the cell are estimated to be mediated by very short peptide segments that approximately conform to specific sequence patterns known as linear motifs (LMs), often present in the disordered regions in the eukaryotic proteins. These peptides have been found to interact with low affinity and are able bind to multiple interactors, thus playing an important role in the PPI networks involving date hubs. In this work, PPI data and de novo motif identification based method (MEME) were used to identify such peptides in three cancer-associated hub proteins-MYC, APC and MDM2. The peptides corresponding to the significant LMs identified for each hub protein were aligned, the overlapping regions across these peptides being termed as overlapping linear peptides (OLPs). These OLPs were thus predicted to be responsible for multiple PPIs of the corresponding hub proteins and a scoring system was developed to rank them. We predicted six OLPs in MYC and five OLPs in MDM2 that scored higher than OLP predictions from randomly generated protein sets. Two OLP sequences from the C-terminal of MYC were predicted to bind with FBXW7, component of an E3 ubiquitin-protein ligase complex involved in proteasomal degradation of MYC. Similarly, we identified peptides in the C-terminal of MDM2 interacting with FKBP3, which has a specific role in auto-ubiquitinylation of MDM2. The peptide sequences predicted in MYC and MDM2 look promising for designing orthosteric inhibitors against possible disease-associated PPIs. Since these OLPs can interact with other proteins as well, these inhibitors should be specific to the targeted interactor to prevent undesired side-effects. This computational framework has been designed to predict and rank the peptide regions that may mediate multiple PPIs and can be applied to other disease-associated date hub proteins for prediction of novel therapeutic targets of small molecule PPI modulators.

A Physical Mechanism and Global Quantification of Breast Cancer

PubMed Central

Yu, Chong; Wang, Jin

2016-01-01

Initiation and progression of cancer depend on many factors. Those on the genetic level are often considered crucial. To gain insight into the physical mechanisms of breast cancer, we construct a gene regulatory network (GRN) which reflects both genetic and environmental aspects of breast cancer. The construction of the GRN is based on available experimental data. Three basins of attraction, representing the normal, premalignant and cancer states respectively, were found on the phenotypic landscape. The progression of breast cancer can be seen as switching transitions between different state basins. We quantified the stabilities and kinetic paths of the three state basins to uncover the biological process of breast cancer formation. The gene expression levels at each state were obtained, which can be tested directly in experiments. Furthermore, by performing global sensitivity analysis on the landscape topography, six key genes (HER2, MDM2, TP53, BRCA1, ATM, CDK2) and four regulations (HER2⊣TP53, CDK2⊣BRCA1, ATM→MDM2, TP53→ATM) were identified as being critical for breast cancer. Interestingly, HER2 and MDM2 are the most popular targets for treating breast cancer. BRCA1 and TP53 are the most important oncogene of breast cancer and tumor suppressor gene, respectively. This further validates the feasibility of our model and the reliability of our prediction results. The regulation ATM→MDM2 has been extensive studied on DNA damage but not on breast cancer. We notice the importance of ATM→MDM2 on breast cancer. Previous studies of breast cancer have often focused on individual genes and the anti-cancer drugs are mainly used to target the individual genes. Our results show that the network-based strategy is more effective on treating breast cancer. The landscape approach serves as a new strategy for analyzing breast cancer on both the genetic and epigenetic levels and can help on designing network based medicine for breast cancer. PMID:27410227

Global gene expression and systems biology analysis of bovine monocyte-derived macrophages in response to in vitro challenge with Mycobacterium bovis.

PubMed

Magee, David A; Taraktsoglou, Maria; Killick, Kate E; Nalpas, Nicolas C; Browne, John A; Park, Stephen D E; Conlon, Kevin M; Lynn, David J; Hokamp, Karsten; Gordon, Stephen V; Gormley, Eamonn; MacHugh, David E

2012-01-01

Mycobacterium bovis, the causative agent of bovine tuberculosis, is a major cause of mortality in global cattle populations. Macrophages are among the first cell types to encounter M. bovis following exposure and the response elicited by these cells is pivotal in determining the outcome of infection. Here, a functional genomics approach was undertaken to investigate global gene expression profiles in bovine monocyte-derived macrophages (MDM) purified from seven age-matched non-related females, in response to in vitro challenge with M. bovis (multiplicity of infection 2:1). Total cellular RNA was extracted from non-challenged control and M. bovis-challenged MDM for all animals at intervals of 2 hours, 6 hours and 24 hours post-challenge and prepared for global gene expression analysis using the Affymetrix® GeneChip® Bovine Genome Array. Comparison of M. bovis-challenged MDM gene expression profiles with those from the non-challenged MDM controls at each time point identified 3,064 differentially expressed genes 2 hours post-challenge, with 4,451 and 5,267 differentially expressed genes detected at the 6 hour and 24 hour time points, respectively (adjusted P-value threshold ≤ 0.05). Notably, the number of downregulated genes exceeded the number of upregulated genes in the M. bovis-challenged MDM across all time points; however, the fold-change in expression for the upregulated genes was markedly higher than that for the downregulated genes. Systems analysis revealed enrichment for genes involved in: (1) the inflammatory response; (2) cell signalling pathways, including Toll-like receptors and intracellular pathogen recognition receptors; and (3) apoptosis. The increased number of downregulated genes is consistent with previous studies showing that M. bovis infection is associated with the repression of host gene expression. The results also support roles for MyD88-independent signalling and intracellular PRRs in mediating the host response to M. bovis.

Heterogeneous distribution of P53 immunoreactivity in human lung adenocarcinoma correlates with MDM2 protein expression, rather than with P53 gene mutation.

PubMed

Koga, T; Hashimoto, S; Sugio, K; Yoshino, I; Nakagawa, K; Yonemitsu, Y; Sugimachi, K; Sueishi, K

2001-07-20

Although the tumor suppressor p53 protein (P53) immunoreactivity and its gene (p53) mutation were reported to be significant prognostic indicators for human lung adenocarcinomas, little is known regarding the relationship between the heterogeneous distribution of P53 and its genetic status in each tumor focus and the clinicopathological significance. To determine how P53 is heterogeneously stabilized in patients, we compared P53 expression to both the p53 allelic mutation in exon 2 approximately 9 by polymerase chain reaction-single strand conformation polymorphism using microdissected DNA fractions, and the immunohistochemical MDM2 expression. Of the 48 positive to P53 in 118 lung adenocarcinomas examined, 10 with heterogeneous P53 expression were closely examined. The higher P53 expression foci in 7 of 10 cases were less differentiated, histologically in respective cases, and were frequently associated with fibrous stroma. Two had genetic mutations in exon 7 of the p53 gene in both the high and low P53 expression foci of cancer tissue indicating no apparent correlation between heterogeneous P53 expression and the occurrence of gene mutation. Immunohistochemical expression of MDM2 was significantly lower in high P53 expression areas (p < 0.05, the mean labeling indices of high and low P53 expression areas being 4.2 +/- 5.4% and 13.6 +/- 12.2%, respectively). In addition, among all the 118 cases examined, MDM2 expression was significantly suppressed in cases of p53 gene mutation, simultaneously with P53 overexpression, as compared with cases without both the p53 mutation and expression (p < 0.001). These findings suggest that the heterogeneous stabilization of P53 in human lung adenocarcinomas could be partly due to suppressed MDM2 expression. The overexpression of non-mutated P53 may afford a protective mechanism in human lung adenocarcinomas. Copyright 2001 Wiley-Liss, Inc.

Does the chronic care model meet the emerging needs of people living with multimorbidity? A systematic review and thematic synthesis

PubMed Central

Abu Dabrh, Abd Moain; Gionfriddo, Michael R.; Erwin, Patricia; Montori, Victor M.

2018-01-01

Background The Chronic Care Model (CCM) emerged in the 1990s as an approach to re-organize primary care and implement critical elements that enable it to proactively attend to patients with chronic conditions. The chronic care landscape has evolved further, as most patients now present with multiple chronic conditions and increasing psychosocial complexity. These patients face accumulating and overwhelming complexity resulting from the sum of uncoordinated responses to each of their problems. Minimally Disruptive Medicine (MDM) was proposed to respond to this challenge, aiming at improving outcomes that matter to patients with the smallest burden of treatment. We sought to critically appraise the extent to which MDM constructs (e.g., reducing patient work, improving patients’ capacity) have been adopted within CCM implementations. Methods We conducted a systematic review and qualitative thematic synthesis of reports of CCM implementations published from 2011–2016. Results CCM implementations were mostly aligned with the healthcare system’s goals, condition-specific, and targeted disease-specific outcomes or healthcare utilization. No CCM implementation addressed patient work. Few reduced treatment workload without adding additional tasks. Implementations supported patient capacity by offering information, but rarely offered practical resources (e.g., financial assistance, transportation), helped patients reframe their biography with chronic illness, or assisted them in engaging with a supportive social network. Few implementations aimed at improving functional status or quality of life, and only one-third of studies were targeted for patients of low socioeconomic status. Conclusion MDM provides a lens to operationalize how to care for patients with multiple chronic conditions, but its constructs remain mostly absent from how implementations of the CCM are currently reported. Improvements to the primary care of patients with multimorbidity may benefit from the application of MDM, and the current CCM implementations that do apply MDM constructs should be considered exemplars for future implementation work. PMID:29420543

MR Guided Pulsed High Intensity Focused Ultrasound Enhancement of Gene Therapy Combined with Androgen Deprivation and Radiotherapy for Prostate Cancer Treatment

DTIC Science & Technology

2012-09-01

for the treatment of prostate tumor-bearing mice using a clinical MRgHIFU device. We performed animal studies for quantitative measurement of the...by measuring the protein expression level of MDM2, p53 and p21 using immunohistochemical staining and west blotting techniques. We also performed...therapy) in implanted prostate tumors in mice in vivo by measuring the protein expression level of MDM, p53 and p21 with time points after treatment

The pre-existing population of 5S rRNA effects p53 stabilization during ribosome biogenesis inhibition

PubMed Central

Onofrillo, Carmine; Galbiati, Alice; Montanaro, Lorenzo; Derenzini, Massimo

2017-01-01

Pre-ribosomal complex RPL5/RPL11/5S rRNA (5S RNP) is considered the central MDM2 inhibitory complex that control p53 stabilization during ribosome biogenesis inhibition. Despite its role is well defined, the dynamic of 5S RNP assembly still requires further characterization. In the present work, we report that MDM2 inhibition is dependent by a pre-existing population of 5S rRNA. PMID:28032591

Regulation of MDM2 Activity by Nucleolin

DTIC Science & Technology

2006-06-01

UbcH5), p53 (1 ml produced in a wheat germ transcription-coupled in vitro translation system (Pro- mega)), GST-Mdm2 (400 ng) and 10 mg ubiquitin (Sigma... Acids Res. 28, 446 (2000). 22. V. Sirri, P. Roussel, M. C. Gendron, D. Hernandez-Verdun, Cytometry 28, 147 (1997). 23. J. Bartkova et al., Nature...DO-1). Immunoprecipitation and GST-pulldown Transfected cells were lysed in 20mM N-2-hydroxyethylpiper- azine-N0-2-ethanesulfonic acid , pH 7.4, 100mM

Self-Reference Refractive Index Sensor Based on Independently Controlled Double Resonances in Side-Coupled U-Shaped Resonators.

PubMed

Ren, Xiaobin; Ren, Kun; Ming, Chengguo

2018-04-28

A plasmonic, refractive, index nanosensor is investigated theoretically and numerically in two U-shaped cavities side-coupled to a metal⁻dielectric⁻metal (MDM) waveguide. A transparency window between two transmission dips is observed. The physical origin of the transmission phenomenon is revealed by mapping the magnetic field distribution. Independent double resonances are realized through the proposed design. Double resonances showed diverse responses to the variations of the structural dimensions. In particular, they presented different dependences on a refraction index of the medium in an individual resonator. One resonance exhibited a remarkable shift with the increase of the refraction index; however, the other resonance remained unchanged. On the basis of this unique characteristic of differing sensitivities, self-reference sensing is discussed. The nanosensor yielded a high sensitivity of 917 nm/RIU and a figure of merit of 180 RIU −1 . This work is helpful in terms of the design of on-chip optical sensors with high sensitivity and improved detection accuracy in complicated environments.

Cell- and Tissue-based Proteome Profiling and Dual Imaging of Apoptosis Markers with Probes Derived from Venetoclax and Idasanutlin.

PubMed

Li, Zhengqiu; Zhu, Dongsheng; Guo, Haijun; Chang, Yu; Ni, Yun; Li, Lin; Hao, Piliang; Xu, Yong; Ding, Ke

2018-05-16

Venetoclax (ABT-199) and idasanutlin (RG7388) are efficient anticancer drugs targeting two essential apoptosis markers, Bcl2 and MDM2, respectively. Recent studies have shown that the combination of these two drugs leads to remarkable enhancement of anticancer efficacy, both in vitro and in vivo. In an attempt to understand the mechanism of this synergistic effect, competitive affinity-based proteome profiling coupled with bioimaging was employed to characterize their protein targets in the same cancer cell line and tumor tissue. A series of protein hits, including ITPR1, GSR, RER1, PDIA3, Apoa1 and Tnfrsf17 were simultaneously identified by pull-down/LC-MS/MS with the two sets of affinity-based probes. Dual imaging was successfully carried out, simultaneously detecting Bcl2 and MDM2 expression in various cancer cells. This could facilitate the novel diagnostic and therapeutic strategies of dual targeting of Bcl2/MDM2. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chromatic characterization of ion-exchanged glass binary phase plates for mode-division multiplexing.

PubMed

Prieto-Blanco, Xesús; Montero-Orille, Carlos; Moreno, Vicente; Mateo, Eduardo F; Liñares, Jesús

2015-04-10

Mode-division multiplexing (MDM) in few-mode fibers is regarded as a promising candidate to increase optical network capacity. A fundamental element for MDM is a modal transformer to LP modes which can be implemented in a free-space basis by using multiregion phase plates, that is, LP plates. Likewise, several wavelengths have to be used due to wavelength multiplexing purposes, optical amplification tasks, and so on. In this work we show that efficient monolithic binary phase plates for different wavelengths can be fabricated by ion-exchange in glass and used for MDM tasks. We introduce an optical characterization method of the chromatic properties of such phase plates which combines the inverse Wentzel-Kramers-Brillouin (IWKB) together with Mach-Zehnder and Michelson-based interferometric techniques. The interferometric method provides a measurement of the phase step for several wavelengths, which characterizes the chromatic properties of the phase plate. Consequently, it is shown that the IWKB method allows us to design and characterize the phase plates in an easy and fast way.

Nanoparticle Based Galectin-1 Gene Silencing, Implications in Methamphetamine Regulation of HIV-1 Infection in Monocyte Derived Macrophages

PubMed Central

Law, Wing Cheung; Mahajan, Supriya D.; Aalinkeel, Ravikumar; Nair, Bindukumar; Sykes, Donald E.; Yong, Ken-Tye; Hui, Rui; Prasad, Paras N.; Schwartz, Stanley A.

2012-01-01

Galectin-1, an adhesion molecule, is expressed in macrophages and implicated in human immunodeficiency virus (HIV-1) viral adsorption. In this study, we investigated the effects of methamphetamine on galectin-1 production in human monocyte derived macrophages (MDM) and the role of galectin-1 in methamphetamine potentiation of HIV-1 infection. Herein we show that levels of galectin-1 gene and protein expression are significantly increased by meth-amphetamine. Furthermore, concomitant incubation of MDM with galectin-1 and methamphetamine facilitates HIV-1 infection compared to galectin-1 alone or methamphetamine alone. We utilized a nanotechnology approach that uses gold nanorod (GNR)-galectin-1 siRNA complexes (nanoplexes) to inhibit gene expression for galectin-1. Nanoplexes significantly silenced gene expression for galectin-1 and reversed the effects of methamphetamine on galectin-1 gene expression. Moreover, the effects of methamphetamine on HIV-1 infection were attenuated in the presence of the nanoplex in MDM. PMID:22689223

Automatic Selection of Clinical Trials Based on A Semantic Web Approach.

PubMed

Cuggia, Marc; Campillo-Gimenez, Boris; Bouzille, Guillaume; Besana, Paolo; Jouini, Wassim; Dufour, Jean-Charles; Zekri, Oussama; Gibaud, Isabelle; Garde, Cyril; Duvauferier, Regis

2015-01-01

Recruitment of patients in clinical trials is nowadays preoccupying, as the inclusion rate is particularly low. The main identified factors are the multiplicity of open clinical trials, the high number and complexity of eligibility criteria, and the additional workload that a systematic search of the clinical trials a patient could be enrolled in for a physician. The principal objective of the ASTEC project is to automate the prescreening phase during multidisciplinary meetings (MDM). This paper presents the evaluation of a computerized recruitment support systems (CRSS) based on semantic web approach. The evaluation of the system was based on data collected retrospectively from a 6 month period of MDM in Urology and on 4 clinical trials of prostate cancer. The classification performance of the ASTEC system had a precision of 21%, recall of 93%, and an error rate equal to 37%. Missing data was the main issue encountered. The system was designed to be both scalable to other clinical domains and usable during MDM process.

National Nutrition Education Clearing House Reference List, General Teacher References.

ERIC Educational Resources Information Center

National Nutrition Education Clearing House, Berkeley, CA.

References applicable to both elementary and secondary levels, as well as background information of importance to teachers in the field of nutrition and nutrition education, are included in this bibliography. Although not a comprehensive list, resources include books, pamphlets, curriculum guides, bibliographies, newsletters, article reprints, and…

Reference. Advisory List of Instructional Media.

ERIC Educational Resources Information Center

North Carolina State Dept. of Public Education, Raleigh.

The reference books featured in this annotated bibliography were selected from those titles that publishers submitted to the North Carolina Department of Public Instruction for review. As such, it is not a comprehensive list of all reference titles in print. This guide organizes the 33 titles into major subject categories: (1) Arts…

p53 and Mdm2 act synergistically to maintain cardiac homeostasis and mediate cardiomyocyte cell cycle arrest through a network of microRNAs.

PubMed

Stanley-Hasnain, Shanna; Hauck, Ludger; Grothe, Daniela; Aschar-Sobbi, Roozbeh; Beca, Sanja; Butany, Jagdish; Backx, Peter H; Mak, Tak W; Billia, Filio

2017-01-01

Defining the roadblocks responsible for cell cycle arrest in adult cardiomyocytes lies at the core of developing cardiac regenerative therapies. p53 and Mdm2 are crucial mediators of cell cycle arrest in proliferative cell types, however, little is known about their function in regulating homeostasis and proliferation in terminally differentiated cell types, like cardiomyocytes. To explore this, we generated a cardiac-specific conditional deletion of p53 and Mdm2 (DKO) in adult mice. Herein we describe the development of a dilated cardiomyopathy, in the absence of cardiac hypertrophy. In addition, DKO hearts exhibited a significant increase in cardiomyocyte proliferation. Further evaluation showed that proliferation was mediated by a significant increase in Cdk2 and cyclin E with downregulation of p21 Cip1 and p27 Kip1 . Comparison of miRNA expression profiles from DKO mouse hearts and controls revealed 11 miRNAs that were downregulated in the DKO hearts and enriched for mRNA targets involved in cell cycle regulation. Knockdown of these miRNAs in neonatal rat cardiomyocytes significantly increased cytokinesis with an upregulation in the expression of crucial cell cycle regulators. These results illustrate the importance of the cooperative activities of p53 and Mdm2 in a network of miRNAs that function to impose a barrier against aberrant cardiomyocyte cell cycle re-entry to maintain cardiac homeostasis.

77 FR 46929 - Airworthiness Directives; Airbus Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-07

...;Prices of new books are listed in the first FEDERAL REGISTER issue of each #0;week. #0; #0; #0; #0;#0... Register approved the incorporation by reference of a certain publication listed in this AD as of September... incorporation by reference of certain other publications listed in this AD as of August 13, 2004 (69 FR 45243...

Regulatory effect of dietary intake of chromium propionate on the response of monocyte-derived macrophages from Holstein cows in mid lactation.

PubMed

Garcia, M; Qu, Y; Scholte, C M; O'Connor, D; Rounds, W; Moyes, K M

2017-08-01

Chromium (Cr) has been reported to enhance immune function and improve insulin sensitivity and performance in beef and dairy cattle. However, its effect on bovine macrophage inflammatory and metabolic response is unknown. The objective of this study was to characterize the effect of dietary Cr on the inflammatory and metabolic response of polarized macrophages ex vivo. Twelve primiparous and 16 multiparous healthy Holstein cows in mid lactation (143 ± 37 d in milk) were enrolled in this study. Cows were fed a common total mixed ration once per day that was top-dressed with 200 g of ground corn containing 1 of 2 dietary treatments: control (CTL, no Cr supplementation) or Cr propionate (CrP, 8 mg of Cr/cow per day) for 35 d. At d 1, 17, and 35 of treatment, blood monocytes were isolated and cultured to obtain 3 monocyte-derived macrophage (MDM) phenotypes: M0 (non-polarized), M1 (pro-inflammatory; IFN-γ polarized) and M2 (anti-inflammatory; IL-4 polarized). The experiment was set in a randomized complete block design. Neither dry matter intake nor milk yield was affected by treatment. Plasma concentrations of metabolites and the metabolic and inflammatory response of MDM in spent media were not affected by treatment. Neither the whole blood cell population nor the specific proportion of leukocytes was affected by the main effect of treatment. However, we did observe a trend for fewer circulating neutrophils in cows fed CrP than in cows fed CTL for 35 d, which may be partly attributable to a greater influx of neutrophils into peripheral tissues, a reduced pro-inflammatory response during disease, or both; this warrants future study. Expression of IGFI was increased in MDM-M0, and expression of CXCL11 tended to increase in MDM-M2 from cows fed CrP compared with cows fed CTL. Expression of SLC2A3 also tended to increase in MDM-M2 from cows fed CrP compared with cows fed CTL at 17 d. Our results suggest that CrP has minimal effect on the inflammatory and metabolic response of MDM for Holstein dairy cows in mid lactation. Future studies are warranted to evaluate the differential regulation of Cr on the inflammatory and metabolic response of leukocytes from dairy cows at different stages of lactation and parity. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Marketing: A Bibliography of Marketing Reference Sources. The University of Rhode Island University Library.

ERIC Educational Resources Information Center

Masten, Lisa

This annotated bibliography provides a selected list of marketing reference sources for undergraduate and graduate business students interested in marketing and related topics. All sources listed are available in the Reference Department at the University Library at the University of Rhode Island Kingston campus. Most sources, with the exception…

Referencing the Unreliable

ERIC Educational Resources Information Center

Barden, Dennis M.

2008-01-01

There are two kinds of references in administrative hires. The most customary is the "on list" references which a candidate asks one to provide. The second kind of reference is the "off list" variety, of which there are two types. Typical is the call one receives from an acquaintance at the hiring institution asking for the "dirt" on one's…

National Nutrition Education Clearing House Reference List, Secondary Teaching Materials and Teacher References.

ERIC Educational Resources Information Center

National Nutrition Education Clearing House, Berkeley, CA.

A reference list of teaching materials and teacher guides in the field of nutrition is compiled in this pamphlet. Primary emphasis is on resources for secondary grades. The section on teaching materials includes books, pamphlets, leaflets, posters, charts, transparencies, ditto masters, kits, games, films, filmstrips, records, TV videotapes, and…

Amount of Postcue Encoding Predicts Amount of Directed Forgetting

ERIC Educational Resources Information Center

Pastotter, Bernhard; Bauml, Karl-Heinz

2010-01-01

In list-method directed forgetting, participants are cued to intentionally forget a previously studied list (List 1) before encoding a subsequently presented list (List 2). Compared with remember-cued participants, forget-cued participants typically show impaired recall of List 1 and improved recall of List 2, referred to as List 1 forgetting and…

Erratum to "10 Gbit/s mode-multiplexed QPSK transmission using MDM-to-MFDM based single coherent receiver for intra- and inter data center networking" [Opt. Commun. 391 (2017) 106-110

NASA Astrophysics Data System (ADS)

Asif, Rameez; Haithem, Mustafa

2018-03-01

We revisited our previous work "10 Gbit/s mode-multiplexed QPSK transmission using MDM-to-MFDM based single coherent receiver for intraand inter data center networking" [Opt. Commun. 391 (2017) 106-110] and discover a mistake in the Appendix 'A', i.e. mode-selective coherent detection technique. In this section, the direct referencing of the previous work at appropriate points is not adequate (page no. 109).

Survival of a bacterioferritin deletion mutant of Brucella melitensis 16M in human monocyte-derived macrophages.

PubMed Central

Denoel, P A; Crawford, R M; Zygmunt, M S; Tibor, A; Weynants, V E; Godfroid, F; Hoover, D L; Letesson, J J

1997-01-01

A bacterioferritin (BFR) deletion mutant of Brucella melitensis 16M was generated by gene replacement. The deletion was complemented with a broad-host-range vector carrying the wild-type bfr gene, pBBR-bfr. The survival and growth of the mutant, B. melitensis PAD 2-78, were similar to those of its parental strain in human monocyte-derived macrophages (MDM). These results suggest that BFR is not essential for the intracellular survival of B. melitensis in human MDM. PMID:9317046

Sensitization of Prostate Cancer Cells to Androgen Deprivation and Radiation via Manipulation of the MDM2 Pathway

DTIC Science & Technology

2005-04-01

cell number apoptosis, and clonogenic assays of LNCaP- MST. Months 1-6. c. Time course experiments of AS effects on AD, RT, and AD+RT in LNCaP and LNCaP...to AS- MDM2, and have not found much of an effect . More recently, we >" 0" have initiated the measurement of SmRNA expression using the Oligo Pollack...AL, Joon DL, Meistrich M, Hachem P, Pollack A. Effect of sequencing androgen deprivation and radiation on prostate cancer growth. Int J Radiat Oncol

Stable isotope sales: Mound Facility customer and shipment summaries, FY 1981

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ruwe, Jr, A H

1982-10-01

A listing is given of Mound Facility's sales of stable isotopes of noble gases, carbon, oxygen, nitrogen, chlorine, and sulfur for Fiscal Year 1981. Purchasers are listed alphabetically and are divided into domestic and foreign groups. A cross-reference index by location is included for domestic customers. Cross-reference listings by isotope purchased are included for all customers.

AgRISTARS documents tracking list report

NASA Technical Reports Server (NTRS)

Hawkins, J. L.

1982-01-01

A quarterly listing of those documents and related publications that have been issued and placed in the AgRISTARS tracking system is presented. The Tracking List Report provides a catalog, by project, of technical publications arranged by type of document and gives the reference AgRISTARS document numbers, title and date of publication, the issuing organization, and the National Technical Information Service reference number.

Systematic analysis of molecular mechanisms for HCC metastasis via text mining approach.

PubMed

Zhen, Cheng; Zhu, Caizhong; Chen, Haoyang; Xiong, Yiru; Tan, Junyuan; Chen, Dong; Li, Jin

2017-02-21

To systematically explore the molecular mechanism for hepatocellular carcinoma (HCC) metastasis and identify regulatory genes with text mining methods. Genes with highest frequencies and significant pathways related to HCC metastasis were listed. A handful of proteins such as EGFR, MDM2, TP53 and APP, were identified as hub nodes in PPI (protein-protein interaction) network. Compared with unique genes for HBV-HCCs, genes particular to HCV-HCCs were less, but may participate in more extensive signaling processes. VEGFA, PI3KCA, MAPK1, MMP9 and other genes may play important roles in multiple phenotypes of metastasis. Genes in abstracts of HCC-metastasis literatures were identified. Word frequency analysis, KEGG pathway and PPI network analysis were performed. Then co-occurrence analysis between genes and metastasis-related phenotypes were carried out. Text mining is effective for revealing potential regulators or pathways, but the purpose of it should be specific, and the combination of various methods will be more useful.

A Spectroscopic Catalog of Nearby, High Proper Motion M subdwarfs

NASA Astrophysics Data System (ADS)

Hejazi, Neda; Lepine, Sebastien; Homeier, Derek

2018-01-01

We present a catalog of 350 metal-poor M subdwarfs, most of them likely from the local Galactic halo population, assembled from medium-resolution observations made at the MDM observatory. All objects are high proper motion stars, with 257 of them having proper motions > 0.4"/yr. We have identified the brightest prototypes for each bin of a grid of 14 spectral subtypes (M0, M0.5, M1, … M6.5) and 9 metallicity bins that go from the moderately metal-poor subdwarfs (sdM), to the more metal-poor extreme subdwarfs (esdM), to the most metal-poor ultra subdwarfs (usdM), each of which is subdivided into three finer metallicity subclasses. The spectral classification by subtype and metallicity class has been determined by a template-fit method, and confirmed by synthetic-model fitting using the BT-Settl spectral grid. We provide the list of the brightest prototypes for each subtype/subclass, as a guide for future high-resolution surveys of low-mass, metal-poor stars.

Attribution of human infections with Shiga toxin-producing Escherichia coli (STEC) to livestock sources and identification of source-specific risk factors, The Netherlands (2010-2014).

PubMed

Mughini-Gras, L; van Pelt, W; van der Voort, M; Heck, M; Friesema, I; Franz, E

2018-02-01

Shiga toxin-producing Escherichia coli (STEC) is a zoonotic pathogen of public health concern whose sources and transmission routes are difficult to trace. Using a combined source attribution and case-control analysis, we determined the relative contributions of four putative livestock sources (cattle, small ruminants, pigs, poultry) to human STEC infections and their associated dietary, animal contact, temporal and socio-econo-demographic risk factors in the Netherlands in 2010/2011-2014. Dutch source data were supplemented with those from other European countries with similar STEC epidemiology. Human STEC infections were attributed to sources using both the modified Dutch model (mDM) and the modified Hald model (mHM) supplied with the same O-serotyping data. Cattle accounted for 48.6% (mDM) and 53.1% (mHM) of the 1,183 human cases attributed, followed by small ruminants (mDM: 23.5%; mHM: 25.4%), pigs (mDM: 12.5%; mHM: 5.7%) and poultry (mDM: 2.7%; mHM: 3.1%), whereas the sources of the remaining 12.8% of cases could not be attributed. Of the top five O-serotypes infecting humans, O157, O26, O91 and O103 were mainly attributed to cattle (61%-75%) and O146 to small ruminants (71%-77%). Significant risk factors for human STEC infection as a whole were the consumption of beef, raw/undercooked meat or cured meat/cold cuts. For cattle-attributed STEC infections, specific risk factors were consuming raw meat spreads and beef. Consuming raw/undercooked or minced meat were risk factors for STEC infections attributed to small ruminants. For STEC infections attributed to pigs, only consuming raw/undercooked meat was significant. Consuming minced meat, raw/undercooked meat or cured meat/cold cuts were associated with poultry-attributed STEC infections. Consuming raw vegetables was protective for all STEC infections. We concluded that domestic ruminants account for approximately three-quarters of reported human STEC infections, whereas pigs and poultry play a minor role and that risk factors for human STEC infection vary according to the attributed source. © 2017 Blackwell Verlag GmbH.

A tryptophanol-derived oxazolopiperidone lactam is cytotoxic against tumors via inhibition of p53 interaction with murine double minute proteins.

PubMed

Soares, Joana; Raimundo, Liliana; Pereira, Nuno A L; dos Santos, Daniel J V A; Pérez, Maria; Queiroz, Glória; Leão, Mariana; Santos, Maria M M; Saraiva, Lucília

2015-01-01

Inactivation of the p53 tumor suppressor protein by interaction with murine double minute (MDM) proteins, MDM2 and MDMX, is a common event in human tumors expressing wild-type p53. In these tumors, the simultaneous inhibition of these interactions with MDMs, for a full p53 reactivation, represents a promising anticancer strategy. Herein, we report the identification of a dual inhibitor of the p53 interaction with MDM2 and MDMX, the (S)-tryptophanol derivative OXAZ-1, from the screening of a small library of enantiopure tryptophanol-derived oxazolopiperidone lactams, using a yeast-based assay. With human colon adenocarcinoma HCT116 cell lines expressing wild-type p53 (HCT116 p53(+/+)) and its p53-null isogenic derivative (HCT116 p53(-/-)), it was shown that OXAZ-1 induced a p53-dependent tumor growth-inhibitory effect. In fact, OXAZ-1 induced p53 stabilization, up-regulated p53 transcription targets, such as MDM2, MDMX, p21, Puma and Bax, and led to PARP cleavage, in p53(+/+), but not in p53(-/-), HCT116 cells. In addition, similar tumor cytotoxic effects were observed for OXAZ-1 against MDMX-overexpressing breast adenocarcinoma MCF-7 tumor cells, commonly described as highly resistant to MDM2-only inhibitors. In HCT116 p53(+/+) cells, the disruption of the p53 interaction with MDMs by OXAZ-1 was further confirmed by co-immunoprecipitation. It was also shown that OXAZ-1 potently triggered a p53-dependent mitochondria-mediated apoptosis, characterized by reactive oxygen species generation, mitochondrial membrane potential dissipation, Bax translocation to mitochondria, and cytochrome c release, and exhibited a p53-dependent synergistic effect with conventional chemotherapeutic drugs. Collectively, in this work, a novel selective activator of the p53 pathway is reported with promising antitumor properties to be explored either alone or combined with conventional chemotherapeutic drugs. Moreover, OXAZ-1 may represent a promising starting scaffold to search for new dual inhibitors of the p53-MDMs interaction. Copyright © 2015 Elsevier Ltd. All rights reserved.

Group-based QSAR and molecular dynamics mechanistic analysis revealing the mode of action of novel piperidinone derived protein-protein inhibitors of p53-MDM2.

PubMed

Goyal, Sukriti; Grover, Sonam; Dhanjal, Jaspreet Kaur; Tyagi, Chetna; Goyal, Manisha; Grover, Abhinav

2014-06-01

Tumour suppressor p53 is known to play a central role in prevention of tumour development, DNA repair, senescence and apoptosis which is in normal cells maintained by negative feedback regulator MDM2 (Murine Double Minute 2). In case of dysfunctioning of this regulatory loop, tumour development starts thus resulting in cancerous condition. Inhibition of p53-MDM2 binding would result in activation of the tumour suppressor. In this study, a novel robust fragment-based QSAR model has been developed for piperidinone derived compounds experimentally known to inhibit p53-MDM2 interaction. The QSAR model developed showed satisfactory statistical parameters for the experimentally reported dataset (r(2)=0.9415, q(2)=0.8958, pred_r(2)=0.8894 and F-test=112.7314), thus judging the robustness of the model. Low standard error values (r(2)_se=0.3003, q(2)_se=0.4009 and pred_r(2)_se=0.3315) confirmed the accuracy of the developed model. The regression equation obtained constituted three descriptors (R2-DeltaEpsilonA, R1-RotatableBondCount and R2-SssOCount), two of which had positive contribution while third showed negative correlation. Based on the developed QSAR model, a combinatorial library was generated and activities of the compounds were predicted. These compounds were docked with MDM2 and two top scoring compounds with binding affinities of -10.13 and -9.80kcal/mol were selected. The binding modes of actions of these complexes were analyzed using molecular dynamics simulations. Analysis of the developed fragment-based QSAR model revealed that addition of unsaturated electronegative groups at R2 site and groups with more rotatable bonds at R1 improved the inhibitory activity of these potent lead compounds. The detailed analysis carried out in this study provides a considerable basis for the design and development of novel piperidinone-based lead molecules against cancer and also provides mechanistic insights into their mode of actions. Copyright © 2014 Elsevier Inc. All rights reserved.

Studying p53 family proteins in yeast: Induction of autophagic cell death and modulation by interactors and small molecules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leão, Mariana; Gomes, Sara; Bessa, Cláudia

In this work, the yeast Saccharomyces cerevisiae was used to individually study human p53, p63 (full length and truncated forms) and p73. Using this cell system, the effect of these proteins on cell proliferation and death, and the influence of MDM2 and MDMX on their activities were analyzed. When expressed in yeast, wild-type p53, TAp63, ΔNp63 and TAp73 induced growth inhibition associated with S-phase cell cycle arrest. This growth inhibition was accompanied by reactive oxygen species production and autophagic cell death. Furthermore, they stimulated rapamycin-induced autophagy. On the contrary, none of the tested p53 family members induced apoptosis either permore » se or after apoptotic stimuli. As previously reported for p53, also TAp63, ΔNp63 and TAp73 increased actin expression levels and its depolarization, suggesting that ACT1 is also a p63 and p73 putative yeast target gene. Additionally, MDM2 and MDMX inhibited the activity of all tested p53 family members in yeast, although the effect was weaker on TAp63. Moreover, Nutlin-3a and SJ-172550 were identified as potential inhibitors of the p73 interaction with MDM2 and MDMX, respectively. Altogether, the yeast-based assays herein developed can be envisaged as a simplified cell system to study the involvement of p53 family members in autophagy, the modulation of their activities by specific interactors (MDM2 and MDMX), and the potential of new small molecules to modulate these interactions. - Highlights: • p53, p63 and p73 are individually studied in the yeast S. cerevisiae. • p53 family members induce ROS production, cell cycle arrest and autophagy in yeast. • p53 family members increase actin depolarization and expression levels in yeast. • MDM2 and MDMX inhibit the activity of p53 family members in yeast. • Yeast can be a useful tool to study the biology and drugability of p53, p63 and p73.« less

AQP2 Abundance is Regulated by the E3-Ligase CHIP Via HSP70.

PubMed

Centrone, Mariangela; Ranieri, Marianna; Di Mise, Annarita; Berlingerio, Sante Princiero; Russo, Annamaria; Deen, Peter M T; Staub, Olivier; Valenti, Giovanna; Tamma, Grazia

2017-01-01

AQP2 expression is mainly controlled by vasopressin-dependent changes in protein abundance which is in turn regulated by AQP2 ubiquitylation and degradation, however the proteins involved in these processes are largely unknown. Here, we investigated the potential role of the CHIP E3 ligase in AQP2 regulation. MCD4 cells and kidney slices were used to study the involvement of the E3 ligase CHIP on AQP2 protein abundance by cell homogenization and immunoprecipitation followed by immunoblotting. We found that AQP2 complexes with CHIP in renal tissue. Expression of CHIP increased proteasomal degradation of AQP2 and HSP70 abundance, a molecular signature of HSP90 inhibition. Increased HSP70 level, secondary to CHIP expression, promoted ERK signaling resulting in increased AQP2 phosphorylation at S261. Phosphorylation of AQP2 at S256 and T269 were instead downregulated. Next, we investigated HSP70 interaction with AQP2, which is important for endocytosis. Compared with AQP2-wt, HSP70 binding decreased in AQP2-S256D and AQP2-S256D-S261D, while increased in AQP2-S256D-S261A. Surprisingly, expression of CHIP-delUbox, displaying a loss of E3 ligase activity, still induced AQP2 degradation, indicating that CHIP does not ubiquitylate and degrade AQP2 itself. Conversely, the AQP2 half-life was increased upon the expression of CHIP-delTPR a domain which binds Hsc70/HSP70 and HSP90. HSP70 has been reported to bind other E3 ligases such as MDM2. Notably, we found that co-expression of CHIP and MDM2 increased AQP2 degradation, whereas co-expression of CHIP with MDM2-delRING, an inactive form of MDM2, impaired AQP2 degradation. Our findings indicate CHIP as a master regulator of AQP2 degradation via HSP70 that has dual functions: (1) as chaperone for AQP2 and (2) as an anchoring protein for MDM2 E3 ligase, which is likely to be involved in AQP2 degradation. © 2017 The Author(s). Published by S. Karger AG, Basel.

Prognostic significance of p16INK4a/p53 in Tunisian patients with breast carcinoma.

PubMed

Karray-Chouayekh, Sondes; Baccouche, Sami; Khabir, Abdelmajid; Sellami-Boudawara, Tahia; Daoud, Jamel; Frikha, Mounir; Jlidi, Rachid; Gargouri, Ali; Mokdad-Gargouri, Raja

2011-09-01

Infiltrating ductal carcinoma (IDC) of the breast is a result of genetic alterations that affect the regulation of the cell cycle check-point and apoptosis. The aim of the present study was analysis using immunohistochemical localization of mouse double minute-2 (mdm2), p16INK4a, p53, bax and bcl-2 markers in Tunisian patients with breast IDC and to determine if there was correlation with the major clinico-pathological parameters and with survival of patients. We showed that the expression of p53, p16INK4a, mdm2, bcl-2, and bax was observed in 46.3%, 20.7%, 38%, 50% and 11.9% of cases, respectively. Statistical analysis revealed that positive expression of mdm2 was associated with larger tumors (P=0.013), whereas bax positivity was more prevalent in younger patients and in tumors of smaller size (P=0.008 and P=0.012 respectively). Furthermore, the expression of p16INK4a correlated with advanced grade (P<0.0001), triple negative tumors (ER-/PR-/HER2-, P=0.001) and mdm2 expression (P=0.017). The absence of nuclear p53 accumulation was predictive of good prognosis as well as when it was associated with negative expression of p16INK4a. Our findings suggest that among the biomarkers tested, p16INK4a might have a useful clinical and prognostic significance in infiltrating ductal carcinoma of the breast. Copyright © 2010 Elsevier GmbH. All rights reserved.

Pre-clinical efficacy and synergistic potential of the MDM2-p53 antagonists, Nutlin-3 and RG7388, as single agents and in combined treatment with cisplatin in ovarian cancer

PubMed Central

Zanjirband, Maryam; Edmondson, Richard J.; Lunec, John

2016-01-01

Ovarian cancer is the fifth leading cause of cancer-related female deaths. Due to serious side effects, relapse and resistance to standard chemotherapy, better and more targeted approaches are required. Mutation of the TP53 gene accounts for 50% of all human cancers. In the remaining malignancies, non-genotoxic activation of wild-type p53 by small molecule inhibition of the MDM2-p53 binding interaction is a promising therapeutic strategy. Proof of concept was established with the cis-imidazoline Nutlin-3, leading to the development of RG7388 and other compounds currently in early phase clinical trials. This preclinical study evaluated the effect of Nutlin-3 and RG7388 as single agents and in combination with cisplatin in a panel of ovarian cancer cell lines. Median-drug-effect analysis showed Nutlin-3 or RG7388 combination with cisplatin was additive to, or synergistic in a p53-dependent manner, resulting in increased p53 activation, cell cycle arrest and apoptosis, associated with increased p21WAF1 protein and/or caspase-3/7 activity compared to cisplatin alone. Although MDM2 inhibition activated the expression of p53-dependent DNA repair genes, the growth inhibitory and pro-apoptotic effects of p53 dominated the response. These data indicate that combination treatment with MDM2 inhibitors and cisplatin has synergistic potential for the treatment of ovarian cancer, dependent on cell genotype. PMID:27223080

Electrostatic polymer-based microdeformable mirror for adaptive optics

NASA Astrophysics Data System (ADS)

Zamkotsian, Frederic; Conedera, Veronique; Granier, Hugues; Liotard, Arnaud; Lanzoni, Patrick; Salvagnac, Ludovic; Fabre, Norbert; Camon, Henri

2007-02-01

Future adaptive optics (AO) systems require deformable mirrors with very challenging parameters, up to 250 000 actuators and inter-actuator spacing around 500 μm. MOEMS-based devices are promising for the development of a complete generation of new deformable mirrors. Our micro-deformable mirror (MDM) is based on an array of electrostatic actuators with attachments to a continuous mirror on top. The originality of our approach lies in the elaboration of layers made of polymer materials. Mirror layers and active actuators have been demonstrated. Based on the design of this actuator and our polymer process, realization of a complete polymer-MDM has been done using two process flows: the first involves exclusively polymer materials while the second uses SU8 polymer for structural layers and SiO II and sol-gel for sacrificial layers. The latest shows a better capability in order to produce completely released structures. The electrostatic force provides a non-linear actuation, while AO systems are based on linear matrices operations. Then, we have developed a dedicated 14-bit electronics in order to "linearize" the actuation, using a calibration and a sixth-order polynomial fitting strategy. The response is nearly perfect over our 3×3 MDM prototype with a standard deviation of 3.5 nm; the influence function of the central actuator has been measured. First evaluation on the cross non-linarities has also been studied on OKO mirror and a simple look-up table is sufficient for determining the location of each actuator whatever the locations of the neighbor actuators. Electrostatic MDM are particularly well suited for open-loop AO applications.

Spacing and lag effects in free recall of pure lists.

PubMed

Kahana, Michael J; Howard, Marc W

2005-02-01

Repeating list items leads to better recall when the repetitions are separated by several unique items than when they are presented successively; the spacing effect refers to improved recall for spaced versus successive repetition (lag > 0 vs. lag = 0); the lag effect refers to improved recall for long lags versus short lags. Previous demonstrations of the lag effect have utilized lists containing a mixture of items with varying degrees of spacing. Because differential rehearsal of items in mixed lists may exaggerate any effects of spacing, it is important to demonstrate these effects in pure lists. As in Toppino and Schneider (1999), we found an overall advantage for recall of spaced lists. We further report the first demonstration of a lag effect in pure lists, with significantly better recall for lists with widely spaced repetitions than for those with moderately spaced repetitions.

Real-time garbage collection for list processing

NASA Technical Reports Server (NTRS)

Shuler, R. L., Jr. (Inventor)

1986-01-01

In a list processing system, small reference counters are maintained in conjunction with memory cells for the purpose of identifying memory cells that become available for re-use. The counters are updated as references to the cells are created and destroyed, and when a counter of a cell is decremented to logical zero the cell is immediately returned to a list of free cells. In those cases where a counter must be incremented beyond the maximum value that can be represented in a small counter, the cell is restructured so that the additional reference count can be represented. The restructuring involves allocating an additional cell, distributing counter, tag, and pointer information among the two cells, and linking both cells appropriately into the existing list structure.

An Evaluation of References to Indexes and Abstracts in Ulrich's 17th Edition.

ERIC Educational Resources Information Center

Wyndham, Diana

1980-01-01

Ulrich's performance in listing references to indexes was tested by comparing its statement of where a journal is indexed with the list of the indexed journals in the indexing/abstracting services themselves. (Author)

Intraperitoneal dedifferentiated liposarcoma showing MDM2 amplification: case report.

PubMed

Grifasi, Carlo; Calogero, Armando; Carlomagno, Nicola; Campione, Severo; D'Armiento, Francesco Paolo; Renda, Andrea

2013-11-26

Liposarcoma is the most common type of soft tissue sarcoma (STS). It is divided into five groups according to histological pattern: well-differentiated, myxoid, round cell, pleomorphic, and dedifferentiated. Dedifferentiated liposarcoma most commonly occurs in the retroperitoneum, while an intraperitoneal location is extremely rare. Only seven cases have been reported in literature. Many pathologists recognize that a large number of intra-abdominal poorly differentiated sarcomas are dedifferentiated liposarcomas. We report a case initially diagnosed as undifferentiated sarcoma that was reclassified as intraperitoneal dedifferentiated liposarcoma showing an amplification of the MDM2 gene. A 59-year-old woman with abdominal pain and constipation was referred to the Department of Advanced Biomedical Sciences, University of Naples Federico II, Naples, Italy, in November 2012. On physical examination, a very large firm mass was palpable in the meso-hypogastrium. Computed tomography (CT) scan showed a heterogeneous density mass (measuring 10 × 19 cm) that was contiguous with the mesentery and compressed the third part of the duodenum and jejunum.At laparotomy, a large mass occupying the entire abdomen was found, adhering to the first jejunal loop and involving the mesentery. Surgical removal of the tumor along with a jejunal resection was performed because the first jejunal loop was firmly attached to the tumor.Macroscopic examination showed a solid, whitish, cerebroid, and myxoid mass, with variable hemorrhage and cystic degeneration, measuring 26 × 19 × 5 cm. Microscopic examination revealed two main different morphologic patterns: areas with spindle cells in a myxoid matrix and areas with pleomorphic cells. The case was initially diagnosed as undifferentiated pleomorphic sarcoma. Histological review showed areas of well-differentiated liposarcoma. Fluorescence in situ hybridization (FISH) analysis was performed and demonstrated an amplification of the MDM2 gene. Definitive diagnosis was intraperitoneal dedifferentiated liposarcoma.No adjuvant therapy was given, but 5 months after laparotomy, the patient presented with a locoregional recurrence and chemotherapy with high-dose ifosfamide was started. No guidelines are available for the management of intraperitoneal dedifferentiated liposarcoma. We report this case to permit the collection of a larger number of cases to improve understanding and management of this tumor. Moreover, this study strongly suggests that poorly differentiated sarcomas should prompt extensive sampling to demonstrate a well-differentiated liposarcoma component and, if possible, FISH analysis.

Intraperitoneal dedifferentiated liposarcoma showing MDM2 amplification: case report

PubMed Central

2013-01-01

Background Liposarcoma is the most common type of soft tissue sarcoma (STS). It is divided into five groups according to histological pattern: well-differentiated, myxoid, round cell, pleomorphic, and dedifferentiated. Dedifferentiated liposarcoma most commonly occurs in the retroperitoneum, while an intraperitoneal location is extremely rare. Only seven cases have been reported in literature. Many pathologists recognize that a large number of intra-abdominal poorly differentiated sarcomas are dedifferentiated liposarcomas. We report a case initially diagnosed as undifferentiated sarcoma that was reclassified as intraperitoneal dedifferentiated liposarcoma showing an amplification of the MDM2 gene. Case presentation A 59-year-old woman with abdominal pain and constipation was referred to the Department of Advanced Biomedical Sciences, University of Naples Federico II, Naples, Italy, in November 2012. On physical examination, a very large firm mass was palpable in the meso-hypogastrium. Computed tomography (CT) scan showed a heterogeneous density mass (measuring 10 × 19 cm) that was contiguous with the mesentery and compressed the third part of the duodenum and jejunum. At laparotomy, a large mass occupying the entire abdomen was found, adhering to the first jejunal loop and involving the mesentery. Surgical removal of the tumor along with a jejunal resection was performed because the first jejunal loop was firmly attached to the tumor. Macroscopic examination showed a solid, whitish, cerebroid, and myxoid mass, with variable hemorrhage and cystic degeneration, measuring 26 × 19 × 5 cm. Microscopic examination revealed two main different morphologic patterns: areas with spindle cells in a myxoid matrix and areas with pleomorphic cells. The case was initially diagnosed as undifferentiated pleomorphic sarcoma. Histological review showed areas of well-differentiated liposarcoma. Fluorescence in situ hybridization (FISH) analysis was performed and demonstrated an amplification of the MDM2 gene. Definitive diagnosis was intraperitoneal dedifferentiated liposarcoma. No adjuvant therapy was given, but 5 months after laparotomy, the patient presented with a locoregional recurrence and chemotherapy with high-dose ifosfamide was started. Conclusions No guidelines are available for the management of intraperitoneal dedifferentiated liposarcoma. We report this case to permit the collection of a larger number of cases to improve understanding and management of this tumor. Moreover, this study strongly suggests that poorly differentiated sarcomas should prompt extensive sampling to demonstrate a well-differentiated liposarcoma component and, if possible, FISH analysis. PMID:24279301

Speaker diarization system on the 2007 NIST rich transcription meeting recognition evaluation

NASA Astrophysics Data System (ADS)

Sun, Hanwu; Nwe, Tin Lay; Koh, Eugene Chin Wei; Bin, Ma; Li, Haizhou

2007-09-01

This paper presents a speaker diarization system developed at the Institute for Infocomm Research (I2R) for NIST Rich Transcription 2007 (RT-07) evaluation task. We describe in details our primary approaches for the speaker diarization on the Multiple Distant Microphones (MDM) conditions in conference room scenario. Our proposed system consists of six modules: 1). Least-mean squared (NLMS) adaptive filter for the speaker direction estimate via Time Difference of Arrival (TDOA), 2). An initial speaker clustering via two-stage TDOA histogram distribution quantization approach, 3). Multiple microphone speaker data alignment via GCC-PHAT Time Delay Estimate (TDE) among all the distant microphone channel signals, 4). A speaker clustering algorithm based on GMM modeling approach, 5). Non-speech removal via speech/non-speech verification mechanism and, 6). Silence removal via "Double-Layer Windowing"(DLW) method. We achieves error rate of 31.02% on the 2006 Spring (RT-06s) MDM evaluation task and a competitive overall error rate of 15.32% for the NIST Rich Transcription 2007 (RT-07) MDM evaluation task.

p53 -Dependent and -Independent Nucleolar Stress Responses

PubMed Central

Olausson, Karl Holmberg; Nistér, Monica; Lindström, Mikael S.

2012-01-01

The nucleolus has emerged as a cellular stress sensor and key regulator of p53-dependent and -independent stress responses. A variety of abnormal metabolic conditions, cytotoxic compounds, and physical insults induce alterations in nucleolar structure and function, a situation known as nucleolar or ribosomal stress. Ribosomal proteins, including RPL11 and RPL5, become increasingly bound to the p53 regulatory protein MDM2 following nucleolar stress. Ribosomal protein binding to MDM2 blocks its E3 ligase function leading to stabilization and activation of p53. In this review we focus on a number of novel regulators of the RPL5/RPL11-MDM2-p53 complex including PICT1 (GLTSCR2), MYBBP1A, PML and NEDD8. p53-independent pathways mediating the nucleolar stress response are also emerging and in particular the negative control that RPL11 exerts on Myc oncoprotein is of importance, given the role of Myc as a master regulator of ribosome biogenesis. We also briefly discuss the potential of chemotherapeutic drugs that specifically target RNA polymerase I to induce nucleolar stress. PMID:24710530

An effective fuzzy kernel clustering analysis approach for gene expression data.

PubMed

Sun, Lin; Xu, Jiucheng; Yin, Jiaojiao

2015-01-01

Fuzzy clustering is an important tool for analyzing microarray data. A major problem in applying fuzzy clustering method to microarray gene expression data is the choice of parameters with cluster number and centers. This paper proposes a new approach to fuzzy kernel clustering analysis (FKCA) that identifies desired cluster number and obtains more steady results for gene expression data. First of all, to optimize characteristic differences and estimate optimal cluster number, Gaussian kernel function is introduced to improve spectrum analysis method (SAM). By combining subtractive clustering with max-min distance mean, maximum distance method (MDM) is proposed to determine cluster centers. Then, the corresponding steps of improved SAM (ISAM) and MDM are given respectively, whose superiority and stability are illustrated through performing experimental comparisons on gene expression data. Finally, by introducing ISAM and MDM into FKCA, an effective improved FKCA algorithm is proposed. Experimental results from public gene expression data and UCI database show that the proposed algorithms are feasible for cluster analysis, and the clustering accuracy is higher than the other related clustering algorithms.

Genetic Variations in the TP53 Pathway in Native Americans Strongly Suggest Adaptation to the High Altitudes of the Andes.

PubMed

Jacovas, Vanessa Cristina; Rovaris, Diego Luiz; Peréz, Orlando; de Azevedo, Soledad; Macedo, Gabriel Souza; Sandoval, José Raul; Salazar-Granara, Alberto; Villena, Mercedes; Dugoujon, Jean-Michel; Bisso-Machado, Rafael; Petzl-Erler, Maria Luiza; Salzano, Francisco Mauro; Ashton-Prolla, Patricia; Ramallo, Virginia; Bortolini, Maria Cátira

2015-01-01

The diversity of the five single nucleotide polymorphisms located in genes of the TP53 pathway (TP53, rs1042522; MDM2, rs2279744; MDM4, rs1563828; USP7, rs1529916; and LIF, rs929271) were studied in a total of 282 individuals belonging to Quechua, Aymara, Chivay, Cabanaconde, Yanke, Taquile, Amantani, Anapia, Uros, Guarani Ñandeva, and Guarani Kaiowá populations, characterized as Native American or as having a high level (> 90%) of Native American ancestry. In addition, published data pertaining to 100 persons from five other Native American populations (Surui, Karitiana, Maya, Pima, and Piapoco) were analyzed. The populations were classified as living in high altitude (≥ 2,500 m) or in lowlands (< 2,500 m). Our analyses revealed that alleles USP7-G, LIF-T, and MDM2-T showed significant evidence that they were selected for in relation to harsh environmental variables related to high altitudes. Our results show for the first time that alleles of classical TP53 network genes have been evolutionary co-opted for the successful human colonization of the Andes.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Capellen, J.; Svec, H.J.; Sage, C.R.

This report covers the year 1973, and lists approximately 8,000 articles of interest to mass spectroscopists. This report consists of three sections, a Bibliography section, an Author Index section and a Key Word Out of Context Index (KWOC Index) section. The Bibliography section lists the authors, the title and the publication data for each article. The Author Index lists the authors' names and the reference numbers of their articles. The KWOC Index lists the key words, the reference numbers of the articles in which the key word appears and the first 100 characters of the title.

A Serials Holdings List Using UNIX Refer.

ERIC Educational Resources Information Center

Boyce, Judith I.; Boyce, Bert R.

1987-01-01

Describes the production of an automated union list of serials holdings at minimal cost by a small consortium of state government libraries in Louisiana. Use of the UNIX Refer system without any modifications for data entry and production is described. (EM)

Catalytic, Enantioselective Synthesis of Stilbene cis-Diamines: A Concise Preparation of (–)-Nutlin-3, a Potent p53/MDM2 Inhibitor

PubMed Central

Davis, Tyler A.

2012-01-01

The first highly diastereo- and enantioselective additions of aryl nitromethane pronucleophiles to aryl aldimines are described. Identification of an electron rich chiral Bis(Amidine) catalyst for this aza-Henry variant was key to this development, leading ultimately to differentially protected cis-stilbene diamines in two steps. This method then became the lynchpin for an enantioselective synthesis of (–)-Nutlin-3 (Hoffmann-LaRoche), a potent cis-imidazoline small molecule inhibitor of p53-MDM2 used extensively as a probe of cell biology and currently in drug development. PMID:22708054

Multiplexer/Demultiplexer Loading Tool (MDMLT)

NASA Technical Reports Server (NTRS)

Brewer, Lenox Allen; Hale, Elizabeth; Martella, Robert; Gyorfi, Ryan

2012-01-01

The purpose of the MDMLT is to improve the reliability and speed of loading multiplexers/demultiplexers (MDMs) in the Software Development and Integration Laboratory (SDIL) by automating the configuration management (CM) of the loads in the MDMs, automating the loading procedure, and providing the capability to load multiple or all MDMs concurrently. This loading may be accomplished in parallel, or single MDMs (remote). The MDMLT is a Web-based tool that is capable of loading the entire International Space Station (ISS) MDM configuration in parallel. It is able to load Flight Equivalent Units (FEUs), enhanced, standard, and prototype MDMs as well as both EEPROM (Electrically Erasable Programmable Read-Only Memory) and SSMMU (Solid State Mass Memory Unit) (MASS Memory). This software has extensive configuration management to track loading history, and the performance improvement means of loading the entire ISS MDM configuration of 49 MDMs in approximately 30 minutes, as opposed to 36 hours, which is what it took previously utilizing the flight method of S-Band uplink. The laptop version recently added to the MDMLT suite allows remote lab loading with the CM of information entered into a common database when it is reconnected to the network. This allows the program to reconfigure the test rigs quickly between shifts, allowing the lab to support a variety of onboard configurations during a single day, based on upcoming or current missions. The MDMLT Computer Software Configuration Item (CSCI) supports a Web-based command and control interface to the user. An interface to the SDIL File Transfer Protocol (FTP) server is supported to import Integrated Flight Loads (IFLs) and Internal Product Release Notes (IPRNs) into the database. An interface to the Monitor and Control System (MCS) is supported to control the power state, and to enable or disable the debug port of the MDMs to be loaded. Two direct interfaces to the MDM are supported: a serial interface (debug port) to receive MDM memory dump data and the calculated checksum, and the Small Computer System Interface (SCSI) to transfer load files to MDMs with hard disks. File transfer from the MDM Loading Tool to EEPROM within the MDM is performed via the MILSTD- 1553 bus, making use of the Real- Time Input/Output Processors (RTIOP) when using the rig-based MDMLT, and via a bus box when using the laptop MDMLT. The bus box is a cost-effective alternative to PC-1553 cards for the laptop. It is noted that this system can be modified and adapted to any avionic laboratory for spacecraft computer loading, ship avionics, or aircraft avionics where multiple configurations and strong configuration management of software/firmware loads are required.

Selected Reference Books of 1971-72

ERIC Educational Resources Information Center

Sheehy, Eugene P.

1973-01-01

The purpose of this annotated list is to present a selection of recent scholarly and foreign works of interest to reference workers in university libraries. The citations are listed under the following headings: guide, bibliography, encyclopedias, dictionaries, newspapers, dissertations, biography, genealogy, literature, education, sociology,…

Atom probe field ion microscopy and related topics: A bibliography 1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

Godfrey, R.D.; Miller, M.K.; Russell, K.F.

1994-10-01

This bibliography, covering the period 1993, includes references related to the following topics: atom probe field ion microscopy (APFIM), field emission (FE), and field ion microscopy (FIM). Technique-oriented studies and applications are included. The references contained in this document were compiled from a variety of sources including computer searches and personal lists of publications. To reduce the length of this document, the references have been reduced to the minimum necessary to locate the articles. The references are listed alphabetically by authors, an Addendum of references missed in previous bibliographies is included.

[A model list of high risk drugs].

PubMed

Cotrina Luque, J; Guerrero Aznar, M D; Alvarez del Vayo Benito, C; Jimenez Mesa, E; Guzman Laura, K P; Fernández Fernández, L

2013-12-01

«High-risk drugs» are those that have a very high «risk» of causing death or serious injury if an error occurs during its use. The Institute for Safe Medication Practices (ISMP) has prepared a high-risk drugs list applicable to the general population (with no differences between the pediatric and adult population). Thus, there is a lack of information for the pediatric population. The main objective of this work is to develop a high-risk drug list adapted to the neonatal or pediatric population as a reference model for the pediatric hospital health workforce. We made a literature search in May 2012 to identify any published lists or references in relation to pediatric and/or neonatal high-risk drugs. A total of 15 studies were found, from which 9 were selected. A model list was developed mainly based on the ISMP one, adding strongly perceived pediatric risk drugs and removing those where the pediatric use was anecdotal. There is no published list that suits pediatric risk management. The list of pediatric and neonatal high-risk drugs presented here could be a «reference list of high-risk drugs » for pediatric hospitals. Using this list and training will help to prevent medication errors in each drug supply chain (prescribing, transcribing, dispensing and administration). Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

The Picture Complexity Effect: Another List Composition Paradox

ERIC Educational Resources Information Center

Nguyen, Khuyen; McDaniel, Mark A.

2015-01-01

"List composition effects" refer to the findings in which a given memory phenomenon shows discrepant patterns across different list designs (i.e., mixed or pure lists). These effects have typically been reported with verbal materials (e.g., word lists, paired associates, sentences); much less research has examined whether these effects…

Shakespeare: A Student's Guide to Basic Reference Sources.

ERIC Educational Resources Information Center

Claener, Anne, Comp.

Basic and standard reference materials dealing with William Shakespeare are listed in this bibliography. Annotated entries are grouped under the following headings: concordances, dictionaries, encyclopedias and handbooks, and bibliographies. The section on bibliographies is further divided into lists of editions of Shakespeare's work, general…

Differential targeting of the cyclin-dependent kinase inhibitor, p21CIP1/WAF1, by chelators with anti-proliferative activity in a range of tumor cell-types

PubMed Central

Moussa, Rayan S.; Kovacevic, Zaklina; Richardson, Des R.

2015-01-01

Chelators such as 2-hydroxy-1-napthylaldehyde isonicotinoyl hydrazone (311) and di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone (Dp44mT) target tumor cell iron pools and inhibit proliferation. These agents also modulate multiple targets, one of which is the cyclin-dependent kinase inhibitor, p21. Hence, this investigation examined the mechanism of action of these compounds in targeting p21. All the chelators up-regulated p21 mRNA in the five tumor cell-types assessed. In contrast, examining their effect on total p21 protein levels, these agents induced either: (1) down-regulation in MCF-7 cells; (2) up-regulation in SK-MEL-28 and CFPAC-1 cells; or (3) had no effect in LNCaP and SK-N-MC cells. The nuclear localization of p21 was also differentially affected by the ligands depending upon the cell-type, with it being decreased in MCF-7 cells, but increased in SK-MEL-28 and CFPAC-1 cells. Further studies assessing the mechanisms responsible for these effects demonstrated that p21 expression was not correlated with p53 status, suggesting a p53-independent mechanism. Considering this, we examined proteins that modulate p21 independently of p53, namely NDRG1, MDM2 and ΔNp63. These studies demonstrated that a dominant negative MDM2 isoform (p75MDM2) closely resembled p21 expression in response to chelation in three cell lines. These data suggest MDM2 may be involved in the regulation of p21 by chelators. PMID:26335183

Inhibition of herpes simplex virus type 1 by the CDK6 inhibitor PD-0332991 (palbociclib) through the control of SAMHD1.

PubMed

Badia, Roger; Angulo, Guillem; Riveira-Muñoz, Eva; Pujantell, Maria; Puig, Teresa; Ramirez, Cristina; Torres-Torronteras, Javier; Martí, Ramón; Pauls, Eduardo; Clotet, Bonaventura; Ballana, Ester; Esté, José A

2016-02-01

Sterile α motif and histidine-aspartate domain-containing protein 1 (SAMHD1) has been shown to restrict retroviruses and DNA viruses by decreasing the pool of intracellular deoxynucleotides. In turn, SAMHD1 is controlled by cyclin-dependent kinases (CDK) that regulate the cell cycle and cell proliferation. Here, we explore the effect of CDK6 inhibitors on the replication of herpes simplex virus type 1 (HSV-1) in primary monocyte-derived macrophages (MDM). MDM were treated with palbociclib, a selective CDK4/6 inhibitor, and then infected with a GFP-expressing HSV-1. Intracellular deoxynucleotide triphosphate (dNTP) content was determined using a polymerase-based method. CDK6 inhibitor palbociclib blocked SAMHD1 phosphorylation, intracellular dNTP levels and HSV-1 replication in MDM at subtoxic concentrations. Treatment of MDM with palbociclib reduced CDK2 activation, measured as the phosphorylation of the T-loop at Thr160. The antiviral activity of palbociclib was lost when SAMHD1 was degraded by viral protein X. Similarly, palbociclib did not block HSV-1 replication in SAMHD1-negative Vero cells at subtoxic concentrations, providing further evidence for a role of SAMHD1 in mediating the antiviral effect. SAMHD1-mediated HSV-1 restriction is controlled by CDK and points to a preferential role for CDK6 and CDK2 as mediators of SAMHD1 activation. Similarly, the restricting activity of SAMHD1 against DNA viruses suggests that control of dNTP availability is the major determinant of its antiviral activity. This is the first study describing the anti-HSV-1 activity of palbociclib. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

The transcription factor, T-bet, primes intestine transplantation rejection and is associated with disrupted mucosal homeostasis.

PubMed

Ranganathan, Sarangarajan; Ashokkumar, Chethan; Ningappa, Mylarappa; Schmitt, Lori; Higgs, Brandon W; Sindhi, Rakesh

2015-04-01

The transcription factor, t-bet, promotes inflammatory polarization and intestinal homing of many inflammatory cells. In previous studies, the t-bet and granulysin genes were upregulated in peripheral blood before and after intestine transplantation (ITx) rejection, but not during rejection, possibly because of sequestration in allograft mucosa. Mucosal sequestration of t-bet and granulysin may also explain the presence of inflammatory CD14+ monocyte-derived macrophages (MDM) and immunoglobulin G+ B-cell lineage cells, and loss of mature non-inflammatory CD138+ plasma cells in allograft mucosa during ITx rejection in these previous studies. T-bet-stained and granulysin-stained cells, MDM and CD138+ plasma cells were evaluated with immunohistochemistry in serial biopsies from 17 children, in whom changes in MDM and CD138+ plasma cells were observed previously. T-bet-positive mucosal cells were significantly higher in postperfusion (P = 0.035) and early posttransplant biopsies (P = 0.016) among rejectors, compared with nonrejectors. T-bet-positive cell counts per high-power field (hpf) were (a) positively correlated with MDM counts/hpf in postperfusion (Spearman r = 0.73; P = 0.01) and early posttransplant biopsies (r = 0.54, r = 0.046), and (b) negatively correlated with CD138+B-/pre-plasma cells in early posttransplant biopsies (r = 0.63, P = 0.038). T-bet expression in CD14+ monocytes, CD19+B cells, and several other leukocyte subsets was higher in random blood samples from two rejectors, compared with those from five normal human subjects and three nonrejectors. Scant granulysin-stained mucosal cells precluded additional evaluation of this cytotoxin and its role in ITx rejection. The transcription factor, t-bet, primes ITx rejection, and associates with disrupted homeostatic relationships between innate and adaptive immune cells in the allograft mucosa during rejection.

Magnetic Droplet Microfluidics as a Platform for the Concentration of [18F]Fluoride and Radiosynthesis of Sulfonyl [18F]Fluoride.

PubMed

Fiel, Somewhere A; Yang, Hua; Schaffer, Paul; Weng, Samuel; Inkster, James A H; Wong, Michael C K; Li, Paul C H

2015-06-17

The radioisotope 18F is often considered the best choice for positron emission tomography (PET) owing to its desirable chemical and radiochemical properties. However, nucleophilic 18F-fluorination of large, water-soluble biomolecules, based on C-F bond formation, has traditionally been difficult. Thus, several aqueous fluorination approaches that offer significant versatility in radiopharmaceutical synthesis with sensitive targeting vectors have been developed. Furthermore, because 18F decays rapidly, production of these 18F-labeled compounds requires an automated process to reduce production time, reduce radiation exposure, and minimize losses due to the transfer of reagents during tracer synthesis. Herein, we report the use of magnetic droplet microfluidics (MDM) as a means to concentrate [18F]fluoride from the cyclotron target solution, followed by the synthesis of an 18F-labeled compound on a microfluidic platform. Using this method, we have demonstrated 18F preconcentration in a small-volume droplet through the use of anion exchanging magnetic particles. By using MDM, the preconcentration step took approximately 5 min, and the [18F]fluoride solution was preconcentrated by 15-fold. After the preconcentration step, an 18F-labeling reaction was performed on the MDM platform using the S-F bond formation in aqueous conditions to produce an arylsulfonyl [18F]fluoride compound which can be used as a prosthetic group to label PET targeting ligands. The high radiochemical purity of 95±1% was comparable to the 96% previously reported using a conventional method. In addition, when MDM was used, the total synthesis time was improved to 15 min with lower reagent volumes (50-60 μL) used.

Glutaminase-containing microvesicles from HIV-1-infected macrophages and immune-activated microglia induce neurotoxicity.

PubMed

Wu, Beiqing; Huang, Yunlong; Braun, Alexander L; Tong, Zenghan; Zhao, Runze; Li, Yuju; Liu, Fang; Zheng, Jialin C

2015-11-06

HIV-1-infected and/or immune-activated microglia and macrophages are pivotal in the pathogenesis of HIV-1-associated neurocognitive disorders (HAND). Glutaminase, a metabolic enzyme that facilitates glutamate generation, is upregulated and may play a pathogenic role in HAND. Our previous studies have demonstrated that glutaminase is released to the extracellular fluid during HIV-1 infection and neuroinflammation. However, key molecular mechanisms that regulate glutaminase release remain unknown. Recent advances in understanding intercellular trafficking have identified microvesicles (MVs) as a novel means of shedding cellular contents. We posit that during HIV-1 infection and immune activation, microvesicles may mediate glutaminase release, generating excessive and neurotoxic levels of glutamate. MVs isolated through differential centrifugation from cell-free supernatants of monocyte-derived macrophages (MDM) and BV2 microglia cell lines were first confirmed in electron microscopy and immunoblotting. As expected, we found elevated number of MVs, glutaminase immunoreactivities, as well as glutaminase enzyme activity in the supernatants of HIV-1 infected MDM and lipopolysaccharide (LPS)-activated microglia when compared with controls. The elevated glutaminase was blocked by GW4869, a neutral sphingomyelinase inhibitor known to inhibit MVs release, suggesting a critical role of MVs in mediating glutaminase release. More importantly, MVs from HIV-1-infected MDM and LPS-activated microglia induced significant neuronal injury in rat cortical neuron cultures. The MV neurotoxicity was blocked by a glutaminase inhibitor or GW4869, suggesting that the neurotoxic potential of HIV-1-infected MDM and LPS-activated microglia is dependent on the glutaminase-containing MVs. These findings support MVs as a potential pathway/mechanism of excessive glutamate generation and neurotoxicity in HAND and therefore MVs may serve as a novel therapeutic target.

High-resolution array comparative genomic hybridization analysis of human bronchial and salivary adenoid cystic carcinoma.

PubMed

Bernheim, Alain; Toujani, Saloua; Saulnier, Patrick; Robert, Thomas; Casiraghi, Odile; Validire, Pierre; Temam, Stéphane; Menard, Philippe; Dessen, Philippe; Fouret, Pierre

2008-05-01

Adenoid cystic carcinoma (ACC) is a rare but distinctive tumor. Oligonucleotide array comparative genomic hybridization has been applied for cataloging genomic copy number alterations (CNAs) in 17 frozen salivary or bronchial tumors. Only four whole chromosome CNAs were found, and most cases had 2-4 segmental CNAs. No high level amplification was observed. There were recurrent gains at 7p15.2, 17q21-25, and 22q11-13, and recurrent losses at 1p35, 6q22-25, 8q12-13, 9p21, 12q12-13, and 17p11-13. The minimal region of gain at 7p15.2 contained the HOXA cluster. The minimal common regions of deletions contained the CDKN2A/CDKN2B, TP53, and LIMA1 tumor suppressor genes. The recurrent deletion at 8q12.3-13.1 contained no straightforward tumor suppressor gene, but the MIRN124A2 microRNA gene, whose product regulates MMP2 and CDK6. Among unique CNAs, gains harbored CCND1, KIT/PDGFRA/KDR, MDM2, and JAK2. The CNAs involving CCND1, MDM2, KIT, CDKN2A/2B, and TP53 were validated by FISH and/or multiplex ligation-dependent probe amplification. Although most tumors overexpressed cyclin D1 compared with surrounding glands, the only case to overexpress MDM2 had the corresponding CNA. In conclusion, our report suggests that ACC is characterized by a relatively low level of structural complexity. Array CGH and immunohistochemical data implicate MDM2 as the oncogene targeted at 12q15. The gain at 4q12 warrants further exploration as it contains a cluster of receptor kinase genes (KIT/PDGFRA/KDR), whose products can be responsive to specific therapies.

NASA ground terminal communication equipment automated fault isolation expert systems

NASA Technical Reports Server (NTRS)

Tang, Y. K.; Wetzel, C. R.

1990-01-01

The prototype expert systems are described that diagnose the Distribution and Switching System I and II (DSS1 and DSS2), Statistical Multiplexers (SM), and Multiplexer and Demultiplexer systems (MDM) at the NASA Ground Terminal (NGT). A system level fault isolation expert system monitors the activities of a selected data stream, verifies that the fault exists in the NGT and identifies the faulty equipment. Equipment level fault isolation expert systems are invoked to isolate the fault to a Line Replaceable Unit (LRU) level. Input and sometimes output data stream activities for the equipment are available. The system level fault isolation expert system compares the equipment input and output status for a data stream and performs loopback tests (if necessary) to isolate the faulty equipment. The equipment level fault isolation system utilizes the process of elimination and/or the maintenance personnel's fault isolation experience stored in its knowledge base. The DSS1, DSS2 and SM fault isolation systems, using the knowledge of the current equipment configuration and the equipment circuitry issues a set of test connections according to the predefined rules. The faulty component or board can be identified by the expert system by analyzing the test results. The MDM fault isolation system correlates the failure symptoms with the faulty component based on maintenance personnel experience. The faulty component can be determined by knowing the failure symptoms. The DSS1, DSS2, SM, and MDM equipment simulators are implemented in PASCAL. The DSS1 fault isolation expert system was converted to C language from VP-Expert and integrated into the NGT automation software for offline switch diagnoses. Potentially, the NGT fault isolation algorithms can be used for the DSS1, SM, amd MDM located at Goddard Space Flight Center (GSFC).

Loci influencing blood pressure identified using a cardiovascular gene-centric array.

PubMed

Ganesh, Santhi K; Tragante, Vinicius; Guo, Wei; Guo, Yiran; Lanktree, Matthew B; Smith, Erin N; Johnson, Toby; Castillo, Berta Almoguera; Barnard, John; Baumert, Jens; Chang, Yen-Pei Christy; Elbers, Clara C; Farrall, Martin; Fischer, Mary E; Franceschini, Nora; Gaunt, Tom R; Gho, Johannes M I H; Gieger, Christian; Gong, Yan; Isaacs, Aaron; Kleber, Marcus E; Mateo Leach, Irene; McDonough, Caitrin W; Meijs, Matthijs F L; Mellander, Olle; Molony, Cliona M; Nolte, Ilja M; Padmanabhan, Sandosh; Price, Tom S; Rajagopalan, Ramakrishnan; Shaffer, Jonathan; Shah, Sonia; Shen, Haiqing; Soranzo, Nicole; van der Most, Peter J; Van Iperen, Erik P A; Van Setten, Jessica; Van Setten, Jessic A; Vonk, Judith M; Zhang, Li; Beitelshees, Amber L; Berenson, Gerald S; Bhatt, Deepak L; Boer, Jolanda M A; Boerwinkle, Eric; Burkley, Ben; Burt, Amber; Chakravarti, Aravinda; Chen, Wei; Cooper-Dehoff, Rhonda M; Curtis, Sean P; Dreisbach, Albert; Duggan, David; Ehret, Georg B; Fabsitz, Richard R; Fornage, Myriam; Fox, Ervin; Furlong, Clement E; Gansevoort, Ron T; Hofker, Marten H; Hovingh, G Kees; Kirkland, Susan A; Kottke-Marchant, Kandice; Kutlar, Abdullah; Lacroix, Andrea Z; Langaee, Taimour Y; Li, Yun R; Lin, Honghuang; Liu, Kiang; Maiwald, Steffi; Malik, Rainer; Murugesan, Gurunathan; Newton-Cheh, Christopher; O'Connell, Jeffery R; Onland-Moret, N Charlotte; Ouwehand, Willem H; Palmas, Walter; Penninx, Brenda W; Pepine, Carl J; Pettinger, Mary; Polak, Joseph F; Ramachandran, Vasan S; Ranchalis, Jane; Redline, Susan; Ridker, Paul M; Rose, Lynda M; Scharnag, Hubert; Schork, Nicholas J; Shimbo, Daichi; Shuldiner, Alan R; Srinivasan, Sathanur R; Stolk, Ronald P; Taylor, Herman A; Thorand, Barbara; Trip, Mieke D; van Duijn, Cornelia M; Verschuren, W Monique; Wijmenga, Cisca; Winkelmann, Bernhard R; Wyatt, Sharon; Young, J Hunter; Boehm, Bernhard O; Caulfield, Mark J; Chasman, Daniel I; Davidson, Karina W; Doevendans, Pieter A; Fitzgerald, Garret A; Gums, John G; Hakonarson, Hakon; Hillege, Hans L; Illig, Thomas; Jarvik, Gail P; Johnson, Julie A; Kastelein, John J P; Koenig, Wolfgang; März, Winfried; Mitchell, Braxton D; Murray, Sarah S; Oldehinkel, Albertine J; Rader, Daniel J; Reilly, Muredach P; Reiner, Alex P; Schadt, Eric E; Silverstein, Roy L; Snieder, Harold; Stanton, Alice V; Uitterlinden, André G; van der Harst, Pim; van der Schouw, Yvonne T; Samani, Nilesh J; Johnson, Andrew D; Munroe, Patricia B; de Bakker, Paul I W; Zhu, Xiaofeng; Levy, Daniel; Keating, Brendan J; Asselbergs, Folkert W

2013-04-15

Blood pressure (BP) is a heritable determinant of risk for cardiovascular disease (CVD). To investigate genetic associations with systolic BP (SBP), diastolic BP (DBP), mean arterial pressure (MAP) and pulse pressure (PP), we genotyped ∼50 000 single-nucleotide polymorphisms (SNPs) that capture variation in ∼2100 candidate genes for cardiovascular phenotypes in 61 619 individuals of European ancestry from cohort studies in the USA and Europe. We identified novel associations between rs347591 and SBP (chromosome 3p25.3, in an intron of HRH1) and between rs2169137 and DBP (chromosome1q32.1 in an intron of MDM4) and between rs2014408 and SBP (chromosome 11p15 in an intron of SOX6), previously reported to be associated with MAP. We also confirmed 10 previously known loci associated with SBP, DBP, MAP or PP (ADRB1, ATP2B1, SH2B3/ATXN2, CSK, CYP17A1, FURIN, HFE, LSP1, MTHFR, SOX6) at array-wide significance (P < 2.4 × 10(-6)). We then replicated these associations in an independent set of 65 886 individuals of European ancestry. The findings from expression QTL (eQTL) analysis showed associations of SNPs in the MDM4 region with MDM4 expression. We did not find any evidence of association of the two novel SNPs in MDM4 and HRH1 with sequelae of high BP including coronary artery disease (CAD), left ventricular hypertrophy (LVH) or stroke. In summary, we identified two novel loci associated with BP and confirmed multiple previously reported associations. Our findings extend our understanding of genes involved in BP regulation, some of which may eventually provide new targets for therapeutic intervention.

Genome-Wide Localization Study of Yeast Pex11 Identifies Peroxisome–Mitochondria Interactions through the ERMES Complex

PubMed Central

Mattiazzi Ušaj, M.; Brložnik, M.; Kaferle, P.; Žitnik, M.; Wolinski, H.; Leitner, F.; Kohlwein, S.D.; Zupan, B.; Petrovič, U.

2015-01-01

Pex11 is a peroxin that regulates the number of peroxisomes in eukaryotic cells. Recently, it was found that a mutation in one of the three mammalian paralogs, PEX11β, results in a neurological disorder. The molecular function of Pex11, however, is not known. Saccharomyces cerevisiae Pex11 has been shown to recruit to peroxisomes the mitochondrial fission machinery, thus enabling proliferation of peroxisomes. This process is essential for efficient fatty acid β-oxidation. In this study, we used high-content microscopy on a genome-wide scale to determine the subcellular localization pattern of yeast Pex11 in all non-essential gene deletion mutants, as well as in temperature-sensitive essential gene mutants. Pex11 localization and morphology of peroxisomes was profoundly affected by mutations in 104 different genes that were functionally classified. A group of genes encompassing MDM10, MDM12 and MDM34 that encode the mitochondrial and cytosolic components of the ERMES complex was analyzed in greater detail. Deletion of these genes caused a specifically altered Pex11 localization pattern, whereas deletion of MMM1, the gene encoding the fourth, endoplasmic-reticulum-associated component of the complex, did not result in an altered Pex11 localization or peroxisome morphology phenotype. Moreover, we found that Pex11 and Mdm34 physically interact and that Pex11 plays a role in establishing the contact sites between peroxisomes and mitochondria through the ERMES complex. Based on these results, we propose that the mitochondrial/cytosolic components of the ERMES complex establish a direct interaction between mitochondria and peroxisomes through Pex11. PMID:25769804

Flavopiridol induces apoptosis in glioma cell lines independent of retinoblastoma and p53 tumor suppressor pathway alterations by a caspase-independent pathway.

PubMed

Alonso, Michelle; Tamasdan, Cristina; Miller, Douglas C; Newcomb, Elizabeth W

2003-02-01

Flavopiridol is a synthetic flavone, which inhibits growth in vitro and in vivo of several solid malignancies such as renal, prostate, and colon cancers. It is a potent cyclin-dependent kinase inhibitor presently in clinical trials. In this study, we examined the effect of flavopiridol on a panel of glioma cell lines having different genetic profiles: five of six have codeletion of p16(INK4a) and p14(ARF); three of six have p53 mutations; and one of six shows overexpression of mouse double minute-2 (MDM2) protein. Independent of retinoblastoma and p53 tumor suppressor pathway alterations, flavopiridol induced apoptosis in all cell lines but through a caspase-independent mechanism. No cleavage products for caspase 3 or its substrate poly(ADP-ribose) polymerase or caspase 8 were detected. The pan-caspase inhibitor Z-VAD-fmk did not inhibit flavopiridol-induced apoptosis. Mitochondrial damage measured by cytochrome c release and transmission electron microscopy was not observed in drug-treated glioma cells. In contrast, flavopiridol treatment induced translocation of apoptosis-inducing factor from the mitochondria to the nucleus. The proteins cyclin D(1) and MDM2 involved in the regulation of retinoblastoma and p53 activity, respectively, were down-regulated early after flavopiridol treatment. Given that MDM2 protein can confer oncogenic properties under certain circumstances, loss of MDM2 expression in tumor cells could promote increased chemosensitivity. After drug treatment, a low Bcl-2/Bax ratio was observed, a condition that may favor apoptosis. Taken together, the data indicate that flavopiridol has activity against glioma cell lines in vitro and should be considered for clinical development in the treatment of glioblastoma multiforme.

Variation in the Early Host-Pathogen Interaction of Bovine Macrophages with Divergent Mycobacterium bovis Strains in the United Kingdom.

PubMed

Jensen, Kirsty; Gallagher, Iain J; Johnston, Nicholas; Welsh, Michael; Skuce, Robin; Williams, John L; Glass, Elizabeth J

2018-03-01

Bovine tuberculosis has been an escalating animal health issue in the United Kingdom since the 1980s, even though control policies have been in place for over 60 years. The importance of the genetics of the etiological agent, Mycobacterium bovis , in the reemergence of the disease has been largely overlooked. We compared the interaction between bovine monocyte-derived macrophages (bMDM) and two M. bovis strains, AF2122/97 and G18, representing distinct genotypes currently circulating in the United Kingdom. These M. bovis strains exhibited differences in survival and growth in bMDM. Although uptake was similar, the number of viable intracellular AF2122/97 organisms increased rapidly, while G18 growth was constrained for the first 24 h. AF2122/97 infection induced a greater transcriptional response by bMDM than G18 infection with respect to the number of differentially expressed genes and the fold changes measured. AF2122/97 infection induced more bMDM cell death, with characteristics of necrosis and apoptosis, more inflammasome activation, and a greater type I interferon response than G18. In conclusion, the two investigated M. bovis strains interact in significantly different ways with the host macrophage. In contrast to the relatively silent infection by G18, AF2122/97 induces greater signaling to attract other immune cells and induces host cell death, which may promote secondary infections of naive macrophages. These differences may affect early events in the host-pathogen interaction, including granuloma development, which could in turn alter the progression of the disease. Therefore, the potential involvement of M. bovis genotypes in the reemergence of bovine tuberculosis in the United Kingdom warrants further investigation. Copyright © 2018 Jensen et al.

Long noncoding RNA MEG3 inhibits proliferation of chronic myeloid leukemia cells by sponging microRNA21.

PubMed

Li, Ziye; Yang, Lin; Liu, Xiaojun; Nie, Ziyuan; Luo, Jianmin

2018-05-14

The long noncoding RNA (lnc) maternally expressed 3 (MEG3) is downregulated in many types of cancers. However, the relationship between lncRNA MEG3, microRNA-21 (miR-21) and chronic myeloid leukemia (CML) blast crisis is unknown. This study examined bone marrow samples from 40 CML patients and 10 healthy donors. Proliferation and apoptosis assays, real-time polymerase chain reaction (PCR), bisulfite sequencing PCR, Western blotting, luciferase assay, RNA pull-down, RNA immunoprecipitation (RIP), co-immunoprecipitation (CoIP) and Chromatin immunoprecipitation (ChIP) were performed. We found that MEG3 and PTEN expression were down-regulated, whereas, MDM2, DNMT1 and miR-21 were up-regulated in the accelerated and blast phases of CML. Treated with 5-azacytidine decreased the level of MDM2, DNMT1 and miR21, but increased the level of MEG3 and PTEN. Overexpression of MEG3 and silencing the expression of miR-21 inhibited proliferation and induced apoptosis. MEG3 overexpression and silencing the expression of miR21 influence the levels of MMP-2, MMP-9, bcl-2 and Bax. MEG3 was able to interact with MDM2 and EZH2. MDM2 could interact with DNMT1 and PTEN. MYC and AKT can interact with EZH2. ChIP-seq showed that the promoter of KLF4 and SFRP2 interacts with DNMT1. In conclusion, lncRNA MEG3 and its target miR21 may serve as novel therapeutic targets for CML blast crisis; and demethylation drugs might also have potential clinical application in treating CML blast crisis. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Co-operative intra-protein structural response due to protein-protein complexation revealed through thermodynamic quantification: study of MDM2-p53 binding

NASA Astrophysics Data System (ADS)

Samanta, Sudipta; Mukherjee, Sanchita

2017-10-01

The p53 protein activation protects the organism from propagation of cells with damaged DNA having oncogenic mutations. In normal cells, activity of p53 is controlled by interaction with MDM2. The well understood p53-MDM2 interaction facilitates design of ligands that could potentially disrupt or prevent the complexation owing to its emergence as an important objective for cancer therapy. However, thermodynamic quantification of the p53-peptide induced structural changes of the MDM2-protein remains an area to be explored. This study attempts to understand the conformational free energy and entropy costs due to this complex formation from the histograms of dihedral angles generated from molecular dynamics simulations. Residue-specific quantification illustrates that, hydrophobic residues of the protein contribute maximum to the conformational thermodynamic changes. Thermodynamic quantification of structural changes of the protein unfold the fact that, p53 binding provides a source of inter-element cooperativity among the protein secondary structural elements, where the highest affected structural elements (α2 and α4) found at the binding site of the protein affects faraway structural elements (β1 and Loop1) of the protein. The communication perhaps involves water mediated hydrogen bonded network formation. Further, we infer that in inhibitory F19A mutation of P53, though Phe19 is important in the recognition process, it has less prominent contribution in the stability of the complex. Collectively, this study provides vivid microscopic understanding of the interaction within the protein complex along with exploring mutation sites, which will contribute further to engineer the protein function and binding affinity.

AgRISTARS documents tracking list report

NASA Technical Reports Server (NTRS)

Hawkins, J. L.

1983-01-01

A quarterly listing of documents issued and placed in the AgRISTARS tracking system is provided. The technical publications are arranged by type of documents. The reference AgRISTARS document number, title and date of publication, the issuing organization, and the National Technical Information Service reference number is given.

Archaeology: A Guide to Reference Sources.

ERIC Educational Resources Information Center

Morrison, Doreen, Comp.

This bibliographic guide lists reference sources available at McGill University for research in prehistory and non-classical archaeology. No exclusively biographical sources have been included, but many of the encyclopedias and handbooks contain biographical information and are annotated accordingly. Titles are listed in the following categories:…

Braille Instruction and Writing Equipment: Reference Circular 86-3.

ERIC Educational Resources Information Center

Library of Congress, Washington, DC. National Library Service for the Blind and Physically Handicapped.

This reference circular lists selected braille instructional materials and braille writing equipment and supplies currently available for purchase. A total of eight braille code books, seven instruction manuals for braille transcribing, and 17 instructional manuals for braille reading are listed. Suggestions are presented about braille instruction…

Resources and References for Family and Consumer Science Teachers, January 1998 to April 1998 [and] References for Family and Consumer Sciences Teachers. December 1996 to January 1998.

ERIC Educational Resources Information Center

Scholl, Jan F., Comp.

This document, which is intended for family and consumer science teachers, contains two lists of recent magazine articles, curriculum guides, bibliographies, videotapes, and other educational resources and references about and for use in secondary-level family and consumer science courses. Included on the first list are the following: 50 magazine…

Enhance the Value of a Research Paper: Choosing the Right References and Writing them Accurately.

PubMed

Bavdekar, Sandeep B

2016-03-01

References help readers identify and locate sources used for justifying the need for conducting the research study, verify methods employed in the study and for discussing the interpretation of results and implications of the study. It is extremely essential that references are accurate and complete. This article provides suggestions regarding choosing references and writing reference list. References are a list of sources that are selected by authors to represent the best documents concerning the research study.1 They constitute the foundation of any research paper. Although generally written towards the end of the article-writing process, they are nevertheless extremely important. They provide the context for the hypothesis and help justify the need for conducting the research study. Authors use references to inform readers about the techniques used for conducting the study and convince them about the appropriateness of methodology used. References help provide appropriate perspective in which the research findings should be seen and interpreted. This communication will discuss the purpose of citations, how to select quality sources for citing and the importance of accuracy while writing the reference list. © Journal of the Association of Physicians of India 2011.

Management & Supervision Personnel Administration Training; General Reference.

ERIC Educational Resources Information Center

United States Government Printing Office, Washington, DC. Training and Career Development Div.

This report lists 329 books in the library of the Training and Career Development Division of the Personnel Service. The books are listed under six categories. They are: personnel administration (46), management and supervision (60), general reference (57), training (20), American Management Association (AMA) publications (118), and United States…

76 FR 16531 - Technical Correction for Neurological Listing Cross-Reference

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-24

... 1-800-325-0778, or visit our Internet site, Social Security Online, at http://www.socialsecurity.gov... SOCIAL SECURITY ADMINISTRATION 20 CFR Part 404 [Docket No. SSA-2011-0019] RIN 0960-AH33 Technical Correction for Neurological Listing Cross-Reference AGENCY: Social Security Administration. ACTION: Final...

Public Administration: A Bibliography of Selected Reference Sources.

ERIC Educational Resources Information Center

Brustman, Mary Jane

This guide presents an annotated list of selected reference sources in public administration. All of the sources listed are found at the Graduate Library for Public Affairs and Policy (GLPP) located at the State University of New York, Albany. Detailed, exhaustive guides in literature, research, indexes, abstracts, statistical sources, government…

Handbook of Reference Sources. Third Edition.

ERIC Educational Resources Information Center

Nichols, Margaret Irby

This third edition of popular and useful reference works, which emphasizes the needs of small libraries, contains 975 annotated entries and lists 201 additional titles (most with bibliographic and order information) in the annotations, representing an expansion of 30 percent over the second edition. The appendix lists 116 basic or core reference…

49 CFR 572.120 - Incorporation by reference.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Child Test Dummy, Beta Version § 572.120 Incorporation by reference. (a) The following materials are... List and Drawings, Hybrid III Six-year-old Child Test Dummy (H-III6C, Beta Version) (June 2002... (vii) The Hybrid III Six-year-old Child Parts/Drawing List. (2) A procedures manual entitled...

Agribusiness Sales, Marketing, and Management. Instructor Guide [and] Student Reference.

ERIC Educational Resources Information Center

Schneiderheinze, Ronald; Wood, Christina

This curriculum guide incorporates the needed components to aid agriculture teachers in the implementation of the Vocational Instructional Management System in agribusiness sales, marketing, and management. The guide begins with a list of the competencies/objectives found in the nine units; list of references and materials; teaching calendar; and…

Primary cardiac dedifferentiated liposarcoma with homologous and heterologous differentiation: a case report.

PubMed

He, Du; Chen, Min; Chen, Huijiao; Liao, Dianying; Wang, Xiaozhou; Zhang, Zhang; Zhang, Hongying

2015-01-01

Liposarcoma originating in the heart is extraordinarily rare. Herein, we report a dedifferentiated liposarcoma arising from the left atrium in a 59-year-old Chinese man. Histologically, the neoplasm predominantly consisted of undifferentiated pleomorphic sarcoma. In addition, the neoplasm exhibited lipoblastic differentiation and osteo-/chondrosarcomatous components. Immunohistochemically, the neoplastic cells were strongly positive for p16, MDM2, and CDK4. Fluorescence in situ hybridization showed MDM2 gene amplification in all of the tumor components. To the best of our knowledge, this is the first published example of cardiac dedifferentiated liposarcoma exhibiting homologous and heterologous differentiation without a well-differentiated liposarcoma component.

Design, Synthesis and Evaluation of 2,5-Diketopiperazines as Inhibitors of the MDM2-p53 Interaction.

PubMed

Pettersson, Mariell; Quant, Maria; Min, Jaeki; Iconaru, Luigi; Kriwacki, Richard W; Waddell, M Brett; Guy, R Kiplin; Luthman, Kristina; Grøtli, Morten

2015-01-01

The transcription factor p53 is the main tumour suppressor in cells and many cancer types have p53 mutations resulting in a loss of its function. In tumours that retain wild-type p53 function, p53 activity is down-regulated by MDM2 (human murine double minute 2) via a direct protein-protein interaction. We have designed and synthesised two series of 2,5-diketopiperazines as inhibitors of the MDM2-p53 interaction. The first set was designed to directly mimic the α-helical region of the p53 peptide, containing key residues in the i, i+4 and i+7 positions of a natural α-helix. Conformational analysis indicated that 1,3,6-trisubstituted 2,5-diketopiperazines were able to place substituents in the same spatial orientation as an α-helix template. The key step of the synthesis involved the cyclisation of substituted dipeptides. The other set of tetrasubstituted 2,5-diketopiperazines were designed based on structure-based docking studies and the Ugi multicomponent reaction was used for the synthesis. This latter set comprised the most potent inhibitors which displayed micromolar IC50-values in a biochemical fluorescence polarisation assay.

Design, Synthesis and Evaluation of 2,5-Diketopiperazines as Inhibitors of the MDM2-p53 Interaction

PubMed Central

Pettersson, Mariell; Quant, Maria; Min, Jaeki; Iconaru, Luigi; Kriwacki, Richard W.; Waddell, M. Brett; Guy, R. Kiplin; Luthman, Kristina; Grøtli, Morten

2015-01-01

The transcription factor p53 is the main tumour suppressor in cells and many cancer types have p53 mutations resulting in a loss of its function. In tumours that retain wild-type p53 function, p53 activity is down-regulated by MDM2 (human murine double minute 2) via a direct protein—protein interaction. We have designed and synthesised two series of 2,5-diketopiperazines as inhibitors of the MDM2-p53 interaction. The first set was designed to directly mimic the α-helical region of the p53 peptide, containing key residues in the i, i+4 and i+7 positions of a natural α-helix. Conformational analysis indicated that 1,3,6-trisubstituted 2,5-diketopiperazines were able to place substituents in the same spatial orientation as an α-helix template. The key step of the synthesis involved the cyclisation of substituted dipeptides. The other set of tetrasubstituted 2,5-diketopiperazines were designed based on structure-based docking studies and the Ugi multicomponent reaction was used for the synthesis. This latter set comprised the most potent inhibitors which displayed micromolar IC50-values in a biochemical fluorescence polarisation assay. PMID:26427060

The effects of a skeletal muscle titin mutation on walking in mice.

PubMed

Pace, Cinnamon M; Mortimer, Sarah; Monroy, Jenna A; Nishikawa, Kiisa C

2017-01-01

Titin contributes to sarcomere assembly, muscle signaling, and mechanical properties of muscle. The mdm mouse exhibits a small deletion in the titin gene resulting in dystrophic mutants and phenotypically normal heterozygotes. We examined the effects of this mutation on locomotion to assess how, and if, changes to muscle phenotype explain observed locomotor differences. Mutant mice are much smaller in size than their siblings and gait abnormalities may be driven by differences in limb proportions and/or by changes to muscle phenotype caused by the titin mutation. We quantified differences in walking gait among mdm genotypes and also determined whether genotypes vary in limb morphometrics. Mice were filmed walking, and kinematic and morphological variables were measured. Mutant mice had a smaller range of motion at the ankle, shorter stride lengths, and shorter stance duration, but walked at the same relative speeds as the other genotypes. Although phenotypically similar to wildtype mice, heterozygous mice frequently exhibited intermediate gait mechanics. Morphological differences among genotypes in hindlimb proportions were small and do not explain the locomotor differences. We suggest that differences in locomotion among mdm genotypes are due to changes in muscle phenotype caused by the titin mutation.

Pathogenic prion protein fragment (PrP106-126) promotes human immunodeficiency virus type-1 infection in peripheral blood monocyte-derived macrophages.

PubMed

Bacot, Silvia M; Feldman, Gerald M; Yamada, Kenneth M; Dhawan, Subhash

2015-02-01

Transfusion of blood and blood products contaminated with the pathogenic form of prion protein Prp(sc), thought to be the causative agent of variant a Creutzfeldt-Jakob disease (vCJD), may result in serious consequences in recipients with a compromised immune system, for example, as seen in HIV-1 infection. In the present study, we demonstrate that treatment of peripheral blood monocyte-derived macrophages (MDM) with PrP106-126, a synthetic domain of PrP(sc) that has intrinsic functional activities related to the full-length protein, markedly increased their susceptibility to HIV-1 infection, induced cytokine secretion, and enhanced their migratory behavior in response to N-formyl-l-methionyl-l-leucyl-l-phenylalanine (fMLP). Live-cell imaging of MDM cultured in the presence of PrP106-126 showed large cell clusters indicative of cellular activation. Tyrosine kinase inhibitor STI-571, protein kinase C inhibitor K252B, and cyclin-dependent kinase inhibitor olomoucine attenuated PrP106-126-induced altered MDM functions. These findings delineate a previously undefined functional role of PrP106-126-mediated host cell response in promoting HIV-1 pathogenesis. Published by Elsevier Inc.

Frequent amplification of receptor tyrosine kinase genes in welldifferentiated/ dedifferentiated liposarcoma.

PubMed

Asano, Naofumi; Yoshida, Akihiko; Mitani, Sachiyo; Kobayashi, Eisuke; Shiotani, Bunsyo; Komiyama, Motokiyo; Fujimoto, Hiroyuki; Chuman, Hirokazu; Morioka, Hideo; Matsumoto, Morio; Nakamura, Masaya; Kubo, Takashi; Kato, Mamoru; Kohno, Takashi; Kawai, Akira; Kondo, Tadashi; Ichikawa, Hitoshi

2017-02-21

Well-differentiated liposarcoma (WDLPS) and dedifferentiated liposarcoma (DDLPS) are closely related tumors commonly characterized by MDM2/CDK4 gene amplification, and lack clinically effective treatment options when inoperable. To identify novel therapeutic targets, we performed targeted genomic sequencing analysis of 19 WDLPS and 37 DDLPS tumor samples using a panel of 104 cancer-related genes (NCC oncopanel v3) developed specifically for genomic testing to select suitable molecular targeted therapies. The results of this analysis indicated that these sarcomas had very few gene mutations and a high frequency of amplifications of not only MDM2 and CDK4 but also other genes. Potential driver mutations were found in only six (11%) samples; however, gene amplification events (other than MDM2 and CDK4 amplification) were identified in 30 (54%) samples. Receptor tyrosine kinase (RTK) genes in particular were amplified in 18 (32%) samples. In addition, growth of a WDLPS cell line with IGF1R amplification was suppressed by simultaneous inhibition of CDK4 and IGF1R, using palbociclib and NVP-AEW541, respectively. Combination therapy with CDK4 and RTK inhibitors may be an effective therapeutic option for WDLPS/DDLPS patients with RTK gene amplification.

Regulation of constitutive and alternative splicing by PRMT5 reveals a role for Mdm4 pre-mRNA in sensing defects in the spliceosomal machinery

PubMed Central

Bezzi, Marco; Teo, Shun Xie; Muller, Julius; Mok, Wei Chuen; Sahu, Sanjeeb Kumar; Vardy, Leah A.; Bonday, Zahid Q.; Guccione, Ernesto

2013-01-01

The tight control of gene expression at the level of both transcription and post-transcriptional RNA processing is essential for mammalian development. We here investigate the role of protein arginine methyltransferase 5 (PRMT5), a putative splicing regulator and transcriptional cofactor, in mammalian development. We demonstrate that selective deletion of PRMT5 in neural stem/progenitor cells (NPCs) leads to postnatal death in mice. At the molecular level, the absence of PRMT5 results in reduced methylation of Sm proteins, aberrant constitutive splicing, and the alternative splicing of specific mRNAs with weak 5′ donor sites. Intriguingly, the products of these mRNAs are, among others, several proteins regulating cell cycle progression. We identify Mdm4 as one of these key mRNAs that senses the defects in the spliceosomal machinery and transduces the signal to activate the p53 response, providing a mechanistic explanation of the phenotype observed in vivo. Our data demonstrate that PRMT5 is a master regulator of splicing in mammals and uncover a new role for the Mdm4 pre-mRNA, which could be exploited for anti-cancer therapy. PMID:24013503

Mechanochemical mechanism for reaction of aluminium nano- and micrometre-scale particles.

PubMed

Levitas, Valery I

2013-11-28

A recently suggested melt-dispersion mechanism (MDM) for fast reaction of aluminium (Al) nano- and a few micrometre-scale particles during fast heating is reviewed. Volume expansion of 6% during Al melting produces pressure of several GPa in a core and tensile hoop stresses of 10 GPa in an oxide shell. Such stresses cause dynamic fracture and spallation of the shell. After spallation, an unloading wave propagates to the centre of the particle and creates a tensile pressure of 3-8 GPa. Such a tensile pressure exceeds the cavitation strength of liquid Al and disperses the melt into small, bare clusters (fragments) that fly at a high velocity. Reaction of the clusters is not limited by diffusion through a pre-existing oxide shell. Some theoretical and experimental results related to the MDM are presented. Various theoretical predictions based on the MDM are in good qualitative and quantitative agreement with experiments, which resolves some basic puzzles in combustion of Al particles. Methods to control and improve reactivity of Al particles are formulated, which are exactly opposite to the current trends based on diffusion mechanism. Some of these suggestions have experimental confirmation.

Genetic Variations in the TP53 Pathway in Native Americans Strongly Suggest Adaptation to the High Altitudes of the Andes

PubMed Central

Peréz, Orlando; de Azevedo, Soledad; Macedo, Gabriel Souza; Sandoval, José Raul; Salazar-Granara, Alberto; Villena, Mercedes; Dugoujon, Jean-Michel; Bisso-Machado, Rafael; Petzl-Erler, Maria Luiza; Salzano, Francisco Mauro; Ashton-Prolla, Patricia; Ramallo, Virginia; Bortolini, Maria Cátira

2015-01-01

The diversity of the five single nucleotide polymorphisms located in genes of the TP53 pathway (TP53, rs1042522; MDM2, rs2279744; MDM4, rs1563828; USP7, rs1529916; and LIF, rs929271) were studied in a total of 282 individuals belonging to Quechua, Aymara, Chivay, Cabanaconde, Yanke, Taquile, Amantani, Anapia, Uros, Guarani Ñandeva, and Guarani Kaiowá populations, characterized as Native American or as having a high level (> 90%) of Native American ancestry. In addition, published data pertaining to 100 persons from five other Native American populations (Surui, Karitiana, Maya, Pima, and Piapoco) were analyzed. The populations were classified as living in high altitude (≥ 2,500 m) or in lowlands (< 2,500 m). Our analyses revealed that alleles USP7-G, LIF-T, and MDM2-T showed significant evidence that they were selected for in relation to harsh environmental variables related to high altitudes. Our results show for the first time that alleles of classical TP53 network genes have been evolutionary co-opted for the successful human colonization of the Andes. PMID:26382048

Effects of delay and noise in a negative feedback regulatory motif

NASA Astrophysics Data System (ADS)

Palassini, Matteo; Dies, Marta

2009-03-01

The small copy number of the molecules involved in gene regulation can induce nontrivial stochastic phenomena such as noise-induced oscillations. An often neglected aspect of regulation dynamics are the delays involved in transcription and translation. Delays introduce analytical and computational complications because the dynamics is non-Markovian. We study the interplay of noise and delays in a negative feedback model of the p53 core regulatory network. Recent experiments have found pronounced oscillations in the concentrations of proteins p53 and Mdm2 in individual cells subjected to DNA damage. Similar oscillations occur in the Hes-1 and NK-kB systems, and in circadian rhythms. Several mechanisms have been proposed to explain this oscillatory behaviour, such as deterministic limit cycles, with and without delay, or noise-induced excursions in excitable models. We consider a generic delayed Master Equation incorporating the activation of Mdm2 by p53 and the Mdm2-promoted degradation of p53. In the deterministic limit and for large delays, the model shows a Hopf bifurcation. Via exact stochastic simulations, we find strong noise-induced oscillations well outside the limit-cycle region. We propose that this may be a generic mechanism for oscillations in gene regulatory systems.

DISTRIBUTION SYSTEM EVALUATIONS OF THE CONTAMINANT CANDIDATE LIST

EPA Science Inventory

The Safe Drinking Water Act (SDWA), as amended in 1996, requires EPA to establish a list of unregulated microbiological and chemical contaminants to aid in priority setting for the Agency's drinking water program. The list is referred to as the Contaminant Candidate List (CCL). A...

The midnight density maximum in the S. Marco V and the S. Marco III equatorial density data sets

NASA Astrophysics Data System (ADS)

Arduini, C.; Laneve, G.; Ponzi, U.

In a previous paper we showed some systematic deviations of the S. Marco V drag balance equatorial density data with respect to the MSIS86 model. We interpreted these deviations as due, at least in part, to the presence of a variable ``Midnight Density Maximum'' (MDM). In the data, there was in fact evidence of some altitude and seasonal variation of this pattern. In the present paper we consider, besides the S. Marco V data base (density measured during 1988), the S. Marco III data base, collected in 1971 almost in the same seasonal period and altitude range, with an instrument very similar to that of the S. Marco V. The use of both data sets is allowing a rather detailed description of the phenomenon as seen by the DBI instrument, for what concerns both the ``seasonal'' and altitude variations. In addition also some longitude effects are evidenced, for instance, by the MITS and QUITO data subsets of S. Marco III, taken respectively around 40 deg and 280 deg East longitude. Notice in addition that S. M. III data refer to the year 1971 (descending part of solar cycle 20) while SMV was launched in 1988 (ascending part of solar cycle 22); the comparison is thus allowing to evidence the persistence of the phenomenon and of its main characteristics. The observed data are consistent ``at large'' for both S. Marco III and V, while the differences in the details are providing hints on the mechanisms of the thermospheric dynamics (tidal theory and neutral-charged interactions). The paper presents the above said features together with a discussion on the characteristics of the two data bases and on their possible relevance for modeling the considered MDM feature.

Driver mutations in TP53 are ubiquitous in high grade serous carcinoma of the ovary.

PubMed

Ahmed, Ahmed Ashour; Etemadmoghadam, Dariush; Temple, Jillian; Lynch, Andy G; Riad, Mohamed; Sharma, Raghwa; Stewart, Colin; Fereday, Sian; Caldas, Carlos; Defazio, Anna; Bowtell, David; Brenton, James D

2010-05-01

Numerous studies have tested the association between TP53 mutations in ovarian cancer and prognosis but these have been consistently confounded by limitations in study design, methodology, and/or heterogeneity in the sample cohort. High-grade serous (HGS) carcinoma is the most clinically important histological subtype of ovarian cancer. As these tumours may arise from the ovary, Fallopian tube or peritoneum, they are collectively referred to as high-grade pelvic serous carcinoma (HGPSC). To identify the true prevalence of TP53 mutations in HGPSC, we sequenced exons 2-11 and intron-exon boundaries in tumour DNA from 145 patients. HGPSC cases were defined as having histological grade 2 or 3 and FIGO stage III or IV. Surprisingly, pathogenic TP53 mutations were identified in 96.7% (n = 119/123) of HGPSC cases. Molecular and pathological review of mutation-negative cases showed evidence of p53 dysfunction associated with copy number gain of MDM2 or MDM4, or indicated the exclusion of samples as being low-grade serous tumours or carcinoma of uncertain primary site. Overall, p53 dysfunction rate approached 100% of confirmed HGPSCs. No association between TP53 mutation and progression-free or overall survival was found. From this first comprehensive mapping of TP53 mutation rate in a homogeneous group of HGPSC patients, we conclude that mutant TP53 is a driver mutation in the pathogenesis of HGPSC cancers. Because TP53 mutation is almost invariably present in HGPSC, it is not of substantial prognostic or predictive significance. Copyright (c) 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

A Reference List of Audiovisual Materials Produced by the United States Government. Supplement, 1980.

ERIC Educational Resources Information Center

National Archives and Records Service (GSA), Washington, DC. National Audiovisual Center.

This supplement to the 1978 reference guide from the National Audiovisual Center (NAC) lists approximately 600 titles recently added to its collection of more than 12,000 titles. Major subject concentrations of the collection are in education, science, social studies, industrial/technical training, and the environmental sciences; formats include…

How to Find Out in: Engineering.

ERIC Educational Resources Information Center

Campana, Jean

This library handbook is a guide for the engineering student. It lists some of the more useful materials and reference books basic to general research and gives their location in the Fogler Library at the University of Maine. Materials are listed in three categories: (1) general reference works--dictionaries, encyclopedias, and handbooks; (2)…

Reference Guide for Teaching Selected Duty Areas from Business, Marketing and Management Occupations.

ERIC Educational Resources Information Center

Rich, John H.

This reference guide was designed to assist business, marketing, and management educators in locating textbook/instructional materials for use in teaching duty areas and task lists for grades 11-14. Duty areas and task lists are matched with selected textbook/instructional publications for the secretarial, general office clerk, and information…

77 FR 29207 - Airworthiness Directives; Airbus Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-17

...;Prices of new books are listed in the first FEDERAL REGISTER issue of each #0;week. #0; #0; #0; #0;#0... Federal Register approved the incorporation by reference of a certain publication listed in this AD as of June 21, 2012. The Director of the Federal Register approved the incorporation by reference of a...

78 FR 36407 - Airworthiness Directives; Bombardier, Inc. Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-18

...;Prices of new books are listed in the first FEDERAL REGISTER issue of each #0;week. #0; #0; #0; #0;#0... Federal Register approved the incorporation by reference of certain publications listed in this AD as of July 23, 2013. The Director of the Federal Register approved the incorporation by reference of certain...

Handbook of Reference Sources. Second Edition.

ERIC Educational Resources Information Center

Nichols, Margaret Irby

Designed to serve as a selection aid for small public libraries and to list important sources available through the major resource centers of the Texas Library System, this bibliography lists 804 annotated reference sources with 126 additional works named within the annotations. The books are grouped into 18 major areas, each of which is broken…

46 CFR 530.12 - Publication.

Code of Federal Regulations, 2013 CFR

2013-10-01

... relevant FMC-assigned agreement number. (d) References. The statement of essential terms shall contain a reference to the “SC Number” as described in § 530.8(d)(1). (e) Terms. (1) The publication of the statement...) Commission listing. The Commission will publish on its website, www.fmc.gov, a listing of the locations of...

46 CFR 530.12 - Publication.

Code of Federal Regulations, 2011 CFR

2011-10-01

... relevant FMC-assigned agreement number. (d) References. The statement of essential terms shall contain a reference to the “SC Number” as described in § 530.8(d)(1). (e) Terms. (1) The publication of the statement...) Commission listing. The Commission will publish on its website, www.fmc.gov, a listing of the locations of...

46 CFR 530.12 - Publication.

Code of Federal Regulations, 2014 CFR

2014-10-01

... relevant FMC-assigned agreement number. (d) References. The statement of essential terms shall contain a reference to the “SC Number” as described in § 530.8(d)(1). (e) Terms. (1) The publication of the statement...) Commission listing. The Commission will publish on its website, www.fmc.gov, a listing of the locations of...

46 CFR 530.12 - Publication.

Code of Federal Regulations, 2012 CFR

2012-10-01

... relevant FMC-assigned agreement number. (d) References. The statement of essential terms shall contain a reference to the “SC Number” as described in § 530.8(d)(1). (e) Terms. (1) The publication of the statement...) Commission listing. The Commission will publish on its website, www.fmc.gov, a listing of the locations of...

Soilcrust References

Science.gov Websites

Soil Crust Home Crust 101 Advanced Gallery References CCERS Site Links Updated: April 24, 2006 References The complete biological soil crust reference list is available in three formats: HTML Version

Site 32SN102, Stutsman County, North Dakota. A Description and Analysis,

DTIC Science & Technology

1978-12-15

LIST OF TABLES .. ......................... iv LIST OF FIGURES. ......................... iv LIST OF PLATES . ........................... v...38 REFERENCES CITED. .......................... 40 APPEND ICES APPENDIX A ( PLATES ) APPENDIX B (MISCELLANEOUS) APPENDIX C...32SN102 .. ................. 18 6. Location of Cranial Anomalies .. .............. 25 iv LIST OF PLATES (Appendix A) Plate la Cutbank prior to

Developing a list of reference chemicals for testing alternatives to whole fish toxicity tests.

PubMed

Schirmer, Kristin; Tanneberger, Katrin; Kramer, Nynke I; Völker, Doris; Scholz, Stefan; Hafner, Christoph; Lee, Lucy E J; Bols, Niels C; Hermens, Joop L M

2008-11-11

This paper details the derivation of a list of 60 reference chemicals for the development of alternatives to animal testing in ecotoxicology with a particular focus on fish. The chemicals were selected as a prerequisite to gather mechanistic information on the performance of alternative testing systems, namely vertebrate cell lines and fish embryos, in comparison to the fish acute lethality test. To avoid the need for additional experiments with fish, the U.S. EPA fathead minnow database was consulted as reference for whole organism responses. This database was compared to the Halle Registry of Cytotoxicity and a collation of data by the German EPA (UBA) on acute toxicity data derived from zebrafish embryos. Chemicals that were present in the fathead minnow database and in at least one of the other two databases were subject to selection. Criteria included the coverage of a wide range of toxicity and physico-chemical parameters as well as the determination of outliers of the in vivo/in vitro correlations. While the reference list of chemicals now guides our research for improving cell line and fish embryo assays to make them widely applicable, the list could be of benefit to search for alternatives in ecotoxicology in general. One example would be the use of this list to validate structure-activity prediction models, which in turn would benefit from a continuous extension of this list with regard to physico-chemical and toxicological data.

22 CFR 121.2 - Interpretations of the U.S. Munitions List.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Interpretations of the U.S. Munitions List. 121... UNITED STATES MUNITIONS LIST Enumeration of Articles § 121.2 Interpretations of the U.S. Munitions List... interpretations have the same force as if they were a part of the U.S. Munitions List category to which they refer...

VizieR Online Data Catalog: WD+dMs from the SUPERBLINK proper motion survey (Skinner+, 2017)

NASA Astrophysics Data System (ADS)

Skinner, J. N.; Morgan, D. P.; West, A. A.; Lepine, S.; Thorstensen, J. R.

2018-06-01

To select for nearby WD+dMs, we used the SUPERBLINK proper motion survey (Lepine et al. 2002, J/AJ/124/1190; Lepine & Shara 2005, Cat. I/298), an ongoing all-sky survey that identifies and characterizes stars with proper motions μ>40 mas/yr. For this study, we used the 2011 July version of SUPERBLINK, which listed 2270481 stars, and was estimated to be >90% complete to V=19.0. We selected WD+dMs based on a combination of V magnitudes derived from the DSS plates (see Lepine & Shara 2005, Cat. I/298), near-UV magnitudes from GALEX, and Ks magnitudes from 2MASS. Using the UV-optical-IR color selection outlined in Skinner et al. (2014AJ....148..115S), we selected targets for spectroscopic follow-up (see bottom panel of Figure 1). We acquired optical spectroscopy of 178 newly identified WD+dM candidates, with the Boller and Chivens CCD spectrograph (CCDS), using both the Hiltner 2.4 m and McGraw-Hill 1.3 m telescopes located at the MDM Observatory. (3 data files).

Plasmonic Roche lobe in metal-dielectric-metal structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shiu, Ruei-Cheng; Lan, Yung-Chiang

2013-07-15

This study investigates a plasmonic Roche lobe that is based on a metal-dielectric-metal (MDM) structure using finite-difference time-domain simulations and theoretical analyses. The effective refractive index of the MDM structure has two centers and is inversely proportional to the distance from the position of interest to the centers, in a manner that is analogous to the gravitational potential in a two-star system. The motion of surface plasmons (SPs) strongly depends on the ratio of permittivities at the two centers. The Lagrange point is an unstable equilibrium point for SPs that propagate in the system. After the SPs have passed throughmore » the Lagrange point, their spread drastically increases.« less

[Aggression and mobbing among correctional officers].

PubMed

Merecz-Kot, Dorota; Cebrzyńska, Joanna

2008-01-01

The paper addresses the issue of violence among correctional officers. The aim of the study was to assess the frequency of exposure to violence in this professional group. The study comprised the sample of 222 correctional officers who voluntary and anonymously fulfilled the MDM questionnaire. The MDM Questionnaire allows for assessing exposure to aggression and mobbing at work. Preliminary assessment of exposure to single aggressive acts and mobbing shows a quite alarming tendency--around one third of subjects under the study experienced repetitive aggressive acts from coworkers and/or superiors. The problem of organizational aggression in correctional institutions should be recognized in details to develop effective preventive measures against violent behaviors occurring at work.

Gold occurrences in the Greenville 1 degree by 2 degrees Quadrangle, South Carolina, Georgia, and North Carolina

USGS Publications Warehouse

D'Agostino, John P.; Mason, George T.; Zupan, Alan J.W.; Maybin, Arthur H.; German, Jerry M.; Abrams, Charlotte E.

1994-01-01

All of the gold mines, prospects, placers, and occurrences known in the Greenville 1° x 2° quadrangle are tabulated in this report. The table lists, in consecutive order by county (fig. 1), the map number of each feature, which is located either on the accompanying Greenville 1° x 2° quadrangle map or figure 2. The known name of the feature; the 7.5' topographic map on the which the gold site is located (if known, within 25 ft or 7.6 m), the Universal Transverse Mercator (UTM) northing and easting grid coordinates from the appropriate 7.5' topographic map; the commodity; remarks; and references are also listed. Some locations are known, but many sites are not verified and their locations are only approximate. References are listed in References Cited and referred to by number to save space.

RADIOISOTOPE TECHNIQUES FOR INSTRUCTION IN THE BIOLOGICAL SCIENCES, A LIST OF ANNOTATED REFERENCES.

ERIC Educational Resources Information Center

HURLBURT, EVELYN M.

REFERENCES TO BIOLOGICAL EXPERIMENTS THAT EMPHASIZE THE USE OF RADIOISOTOPES AS TRACERS ARE INCLUDED IN THIS ANNOTATED BIBLIOGRAPHY. MATERIALS INCLUDED ARE CONSIDERED TO BE READILY AVAILABLE AND WERE PUBLISHED AFTER 1960. SECTION I IS COMPOSED OF SELECTED SOURCES. ENTRIES INCLUDE (1) COMPLETE CITATIONS, (2) A BRIEF ANNOTATION, AND (3) LISTS OF…

40 CFR 152.90 - The selective method.

Code of Federal Regulations, 2010 CFR

2010-07-01

... authorizations or offers to pay. Refer to § 152.95. (6) Documentation of a data gap. Refer to § 152.96. [49 FR... data gap. (a) List of data requirements. Each applicant must submit a list of the data requirements... gap procedures in § 152.96 that a conditional requirement need not be satisfied by the submission or...

77 FR 4457 - Amendment of Class D Airspace; Altus AFB, OK

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-30

...;Prices of new books are listed in the first FEDERAL REGISTER issue of each #0;week. #0; #0; #0; #0;#0... Director of the Federal Register approves this incorporation by reference action under 1 CFR part 51... incorporated by reference in 14 CFR 71.1. The Class D airspace designations listed in this document will be...

77 FR 14679 - Airworthiness Directives; Airbus Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-13

...;Prices of new books are listed in the first FEDERAL REGISTER issue of each #0;week. #0; #0; #0; #0;#0... 17, 2012. The Director of the Federal Register approved the incorporation by reference of certain... incorporation by reference of a certain publication listed in this AD as of June 24, 2002 (67 FR 35425, May 20...

Parents' Guide to the Development of Preschool Children with Disabilities: Resources and Services. Reference Circular, No. 92-1.

ERIC Educational Resources Information Center

Library of Congress, Washington, DC. National Library Service for the Blind and Physically Handicapped.

Intended for parents of preschool children with visual or physical disabilities, this reference circular lists organizations offering materials and services at the national level as well as books available from standard commercial outlets. The first section lists 14 organizations providing special format materials (Braille, cassettes, large print,…

The Explorer's Guide to the Universe. A Reading List for Planetary and Space Science.

ERIC Educational Resources Information Center

Zucker, Sandy, Comp.; And Others

This reading list for planetary and space science presents general references and bibliographies intended to supply background to the non-scientist, as well as more specific sources for recent discoveries. Included are NASA publications and those which have been commercially produced. References are sectioned into these topics: (1) general reviews…

A Guide to Reviews of Books, Plays, Films: A Selected Bibliography.

ERIC Educational Resources Information Center

Miller, Elaine N.

Forty reference sources for book, play, and film reviews are listed in this annotated bibliography: most of the titles cited are periodical indexes. A general section lists sources not restricted by subject or which contain references to all three kinds of reviews. Subsequent sections are the broad subject categories of humanities, science, social…

International Bibliography of Computer-Assisted Terminology.

ERIC Educational Resources Information Center

Krommer-Benz, Magdalena, Comp.

Because of the need for adequate reference tools in the new area of data banks for the field of terminology (there are currently 25 term banks in existence and more are planned), this bibliography lists some 350 references selected from a large number of both primary and secondary sources. It includes some entries selected from a list of…

The NASA/MSFC global reference atmospheric model: 1990 version (GRAM-90). Part 2: Program/data listings

NASA Technical Reports Server (NTRS)

Justus, C. G.; Alyea, F. N.; Cunnold, D. M.; Jeffries, W. R., III; Johnson, D. L.

1991-01-01

A new (1990) version of the NASA/MSFC Global Reference Atmospheric Model (GRAM-90) was completed and the program and key data base listing are presented. GRAM-90 incorporate extensive new data, mostly collected under the Middle Atmosphere Program, to produce a completely revised middle atmosphere model (20 to 120 km). At altitudes greater than 120 km, GRAM-90 uses the NASA Marshall Engineering Thermosphere model. Complete listings of all program and major data bases are presented. Also, a test case is included.

Primary dermal pleomorphic liposarcoma: utility of adipophilin and MDM2/CDK4 immunostainings.

PubMed

Ramírez-Bellver, Jose L; López, Joaquín; Macías, Elena; Alegría-Landa, Victoria; Gimeno, Ignacio; Pérez-Plaza, Alejandra; Kutzner, Heinz; Requena, Luis

2017-03-01

Liposarcoma, usually arises in deep soft tissues and pleomorphic liposarcoma (PL), is the rarest histopathologic variant. However, 15 cases of entirely dermal PL have been reported. We describe a case of a 79-year-old man who developed a rapidly growing nodule on his thorax. Excisional biopsy was performed and immunohistochemical studies were carried. The lesion was a well-circumscribed dermal nodule composed of multivacuolated pleomorphic lipoblasts and atypical mitotic figures. Neoplastic cells expressed CD10 and resulted negative S100 protein, Melan-A, MITF-1, AE1/AE3, CD4, CD68 (PGM1), retinoblastoma gene family protein, pericentrine and lysozyme. Adipophilin stain showed the lipid contents in the cytoplasm of the neoplastic cells. MDM2 and CDK4 resulted both negative. A diagnosis of primary dermal PL was made. This case shows the utility of adipophilin immunostaining to prove the lipid contents in neoplastic cells, which has the advantage of using formalin-fixed paraffin-embedded tissue and making needless frozen sections and ultrastructural studies to show these findings. Negative MDM2/CDK4 staining in our case argues against the possibility of dedifferentiated liposarcoma and further supports the diagnosis of true PL. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Macrophage secretome from women with HIV-associated neurocognitive disorders.

PubMed

Colon, Krystal; Perez-Laspiur, Juliana; Quiles, Raymond; Rodriguez, Yolanda; Wojna, Valerie; Shaffer, Scott A; Leszyk, John; Skolasky, Richard L; Melendez, Loyda M

2016-02-01

Thirty to 50% of HIV patients develop HIV-associated neurocognitive disorders (HANDs) despite combined antiretroviral therapy. HIV-1-infected macrophages release viral and cellular proteins that induce neuronal degeneration and death. We hypothesize that changes in the macrophage secretome of HIV-1 seropositive patients with HAND may dissect proteins related to neurotoxicity. Monocyte-derived macrophages (MDMs) were isolated from the peripheral blood of 12 HIV+ and four HIV- women characterized for neurocognitive function. Serum-free MDM supernatants were collected for protein isolation and quantification with iTRAQ® labeling. Protein identification was performed using a LTQ Orbitrap Velos mass spectrometer and validated in MDM supernatants and in plasma using ELISA. Three proteins were different between normal cognition (NC) and asymptomatic neurocognitive disorders (ANI), six between NC and HIV-associated dementia (HAD), and six between NC and HAD. Among these, S100A9 was decreased in plasma from patients with ANI, and metalloproteinase 9 was decreased in the plasma of all HIV+ patients regardless of cognitive status, and was significantly reduced in supernatant of MDM isolated from patients with ANI. S100A9 and metalloproteinase 9 have been associated with inflammation and cognitive impairment, and therefore represent potential targets for HAND treatment. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Thymosin α1 modifies podosome architecture and promptly stimulates the expression of podosomal markers in mature macrophages.

PubMed

Serafino, Annalucia; Andreola, Federica; Pittaluga, Eugenia; Krasnowska, Ewa K; Nicotera, Giuseppe; Sferrazza, Gianluca; Sinibaldi Vallebona, Paola; Pierimarchi, Pasquale; Garaci, Enrico

2015-01-01

The immunomodulatory activity of thymosin α1 (Tα1) on innate immunity has been extensively described, but its mechanism of action is not completely understood. We explored the possibility that Tα1-stimulation could affect the formation of podosomes, the highly dynamic, actin-rich, adhesion structures involved in macrophage adhesion/chemotaxis. The following methods were used: optical and scanning electron microscopy for analyzing morphology of human monocyte-derived macrophages (MDMs); time-lapse imaging for visualizing the time-dependent modifications induced at early times by Tα1 treatment; confocal microscopy and Western blot for analyzing localization and expression of podosome components; and Matrigel Migration Assay and zymography for testing MDM invasive ability and metalloproteinase secretion. We obtained data to support that Tα1 could affect MDM motility, invasion and chemotaxis by promptly stimulating assembly and disassembly of podosomal structures. At very early times after its addition to cell culture medium and within 1 h of treatment, Tα1 induces modifications in MDM morphology and in podosomal components that are suggestive of increased podosome turnover. Since impairment of podosome formation leads to reduced innate immunity and is associated with several immunodeficiency disorders, we confirm the validity of Tα1 as a potent activator of innate immunity and suggest possible new clinical application of this thymic peptide.

Ankyrin Repeat Domain Protein 2 and Inhibitor of DNA Binding 3 Cooperatively Inhibit Myoblast Differentiation by Physical Interaction*

PubMed Central

Mohamed, Junaith S.; Lopez, Michael A.; Cox, Gregory A.; Boriek, Aladin M.

2013-01-01

Ankyrin repeat domain protein 2 (ANKRD2) translocates from the nucleus to the cytoplasm upon myogenic induction. Overexpression of ANKRD2 inhibits C2C12 myoblast differentiation. However, the mechanism by which ANKRD2 inhibits myoblast differentiation is unknown. We demonstrate that the primary myoblasts of mdm (muscular dystrophy with myositis) mice (pMBmdm) overexpress ANKRD2 and ID3 (inhibitor of DNA binding 3) proteins and are unable to differentiate into myotubes upon myogenic induction. Although suppression of either ANKRD2 or ID3 induces myoblast differentiation in mdm mice, overexpression of ANKRD2 and inhibition of ID3 or vice versa is insufficient to inhibit myoblast differentiation in WT mice. We identified that ANKRD2 and ID3 cooperatively inhibit myoblast differentiation by physical interaction. Interestingly, although MyoD activates the Ankrd2 promoter in the skeletal muscles of wild-type mice, SREBP-1 (sterol regulatory element binding protein-1) activates the same promoter in the skeletal muscles of mdm mice, suggesting the differential regulation of Ankrd2. Overall, we uncovered a novel pathway in which SREBP-1/ANKRD2/ID3 activation inhibits myoblast differentiation, and we propose that this pathway acts as a critical determinant of the skeletal muscle developmental program. PMID:23824195

Morphine and galectin-1 modulate HIV-1 infection of human monocytes-derived macrophages

PubMed Central

Reynolds, Jessica L.; Law, Wing Cheung; Mahajan, Supriya D.; Aalinkeel, Ravikumar; Nair, Bindukumar; Sykes, Donald E.; Mammen, Manoj J.; Yong, Ken-Tye; Hui, Rui; Prasad, Paras N.; Schwartz, Stanley A.

2012-01-01

Morphine is a widely abused, addictive drug that modulates immune function. Macrophages are a primary reservoir of HIV-1; therefore, they not only play a role in the development of this disease but also impact the overall course of disease progression. Galectin-1 is a member of a family of β-galactoside-binding lectins that are soluble adhesion molecules and that mediate direct cell-pathogen interactions during HIV-1 viral adhesion. Since the drug abuse epidemic and the HIV-1 epidemic are closely interrelated we propose that increased expression of galectin-1 induced by morphine may modulate HIV-1 infection of human monocytes-derived macrophages (MDM). Here, we show that galectin-1 gene and protein expression are potentiated by incubation with morphine. Confirming previous studies, morphine alone or galectin-1 alone enhance HIV-1 infection of MDM. Concomitant incubation with exogenous galectin-1 and morphine potentiated HIV-1 infection of MDM. We utilized a nanotechnology approach that uses gold nanorod-galectin-1 siRNA complexes (nanoplexes) to inhibit gene expression for galectin-1. We found that nanoplexes silenced gene expression for galectin-1 and the nanoplexes reversed the effects of morphine on galectin-1 expression. Furthermore, the effects of morphine on HIV-1 infection were reduced in the presence of the nanoplex. PMID:22430735

Cyclophilin B induces chemoresistance by degrading wild type p53 via interaction with MDM2 in colorectal cancer.

PubMed

Choi, Tae Gyu; Nguyen, Minh Nam; Kim, Jieun; Jo, Yong Hwa; Jang, Miran; Nguyen, Ngoc Ngo Yen; Yun, Hyeong Rok; Choe, Wonchae; Kang, Insug; Ha, Joohun; Tang, Dean G; Kim, Sung Soo

2018-06-06

Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths worldwide. Chemoresistance is a major problem for effective therapy in CRC. Here, we investigated the mechanism by which peptidylprolyl isomerase B (PPIB; cyclophilin B, CypB) regulates chemoresistance in CRC. We found that CypB is a novel wild type p53 (p53WT)-inducible gene but a negative regulator of p53WT in response to oxaliplatin treatment. Overexpression of CypB shortens the half-life of p53WT and inhibits oxaliplatin-induced apoptosis in CRC cells, whereas knockdown of CypB lengthens the half-life of p53WT and stimulates p53WT dependent apoptosis. CypB interacts directly with MDM2, and enhances MDM2-dependent p53WT ubiquitination and degradation. Furthermore, we firmly validated using bioinformatics analyses that overexpression of CypB is associated with poor prognosis in CRC progression and chemoresistance. Hence, we suggest a novel mechanism of chemoresistance caused by overexpressed CypB, which may help to develop new anti-cancer drugs. We also propose that CypB may be utilized as a predictive biomarker in CRC patients. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Cdk5 regulates PSD-95 ubiquitination in neurons

PubMed Central

Bianchetta, Michael J.; Lam, TuKiet T.; Jones, Stephen N.; Morabito, Maria A.

2011-01-01

The kinase Cdk5 and its activator p35 have been implicated in drug addiction, neurodegenerative diseases such as Alzheimer’s, learning and memory, and synapse maturation and plasticity. However the molecular mechanisms by which Cdk5 regulates synaptic plasticity are still unclear. PSD-95 is a major postsynaptic scaffolding protein of glutamatergic synapses that regulates synaptic strength and plasticity. PSD-95 is ubiquitinated by the Ubiquitin E3 Ligase Mdm2, and rapid and transient PSD-95 ubiquitination has been implicated in NMDA receptor-induced AMPA receptor endocytosis. Here we demonstrate that genetic or pharmacological reduction of Cdk5 activity increases the interaction of Mdm2 with PSD-95 and enhances PSD-95 ubiquitination without affecting PSD-95 protein levels in vivo in mice, suggesting a non-proteolytic function of ubiquitinated PSD-95 at synapses. We show that PSD-95 ubiquitination correlates with increased interaction with β-adaptin, a subunit of the clathrin adaptor protein complex AP-2. This interaction is increased by genetic reduction of Cdk5 activity or NMDA receptor stimulation and is dependent on Mdm2. Together these results support a function for Cdk5 in regulating PSD-95 ubiqutination and its interaction with AP-2 and suggest a mechanism by which PSD-95 may regulate NMDA receptor-induced AMPA receptor endocytosis. PMID:21849563