Imbalanced gp130 signalling in ApoE-deficient mice protects against atherosclerosis.

PubMed

Jones, Gareth W; McLeod, Louise; Kennedy, Catherine L; Bozinovski, Steven; Najdovska, Meri; Jenkins, Brendan J

2015-02-01

Interleukin (IL)-6 is a key modulator of the acute phase response (APR), and while both are implicated in atherosclerosis, the pathological role of specific IL-6 signalling cascades is ill-defined. Since IL-6 employs the cytokine receptor gp130 to primarily activate the STAT3 pathway, here we evaluate whether gp130-dependent STAT3 activation modulates atherosclerosis. High-fat diet-induced atherosclerosis was established in ApoE(-/-) mice crossed with gp130(F/F) knock-in mice displaying elevated gp130-dependent STAT3 activation and production of the APR protein, serum amyloid A (SAA). Also generated were gp130(F/F):Stat3(-/+):ApoE(-/-) mice displaying genetically-normalised STAT3 activation and SAA levels, and bone marrow chimeras involving ApoE(-/-) and gp130(F/F):ApoE(-/-) mice. At 10 weeks post high-fat diet, aortic atherosclerotic lesions, including the presence of CD68(+) macrophages, and plasma lipid and SAA profiles, were assessed. Aortic plaque development and plasma triglyceride levels in gp130(F/F):ApoE(-/-) mice were significantly reduced (3-fold, P < 0.001) compared to ApoE(-/-) littermates. By contrast, in gp130(F/F):ApoE(-/-) mice, atherosclerotic plaques contained augmented CD68(+) macrophage infiltrates, and plasma SAA levels were elevated, compared to ApoE(-/-) mice. Atherosclerotic lesion development and plasma triglyceride levels in gp130(F/F):ApoE(-/-) and gp130(F/F):Stat3(-/+):ApoE(-/-) mice were comparable, despite a significant (P < 0.05) reduction in macrophage numbers in lesions, and also plasma SAA levels, in gp130(F/F):Stat3(-/+):ApoE(-/-) mice. Aortic plaque development and plasma triglyceride levels were comparable in ApoE(-/-) mice reconstituted with gp130(F/F):ApoE(-/-) (ApoE(F/F:ApoE)) or ApoE(-/-) (ApoE(ApoE)) bone marrow cells. Deregulation of gp130/STAT3 signalling augments the APR and macrophage infiltration during atherosclerosis without impacting on the development of aortic plaques. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Network-based differential gene expression analysis suggests cell cycle related genes regulated by E2F1 underlie the molecular difference between smoker and non-smoker lung adenocarcinoma

PubMed Central

2013-01-01

Background Differential gene expression (DGE) analysis is commonly used to reveal the deregulated molecular mechanisms of complex diseases. However, traditional DGE analysis (e.g., the t test or the rank sum test) tests each gene independently without considering interactions between them. Top-ranked differentially regulated genes prioritized by the analysis may not directly relate to the coherent molecular changes underlying complex diseases. Joint analyses of co-expression and DGE have been applied to reveal the deregulated molecular modules underlying complex diseases. Most of these methods consist of separate steps: first to identify gene-gene relationships under the studied phenotype then to integrate them with gene expression changes for prioritizing signature genes, or vice versa. It is warrant a method that can simultaneously consider gene-gene co-expression strength and corresponding expression level changes so that both types of information can be leveraged optimally. Results In this paper, we develop a gene module based method for differential gene expression analysis, named network-based differential gene expression (nDGE) analysis, a one-step integrative process for prioritizing deregulated genes and grouping them into gene modules. We demonstrate that nDGE outperforms existing methods in prioritizing deregulated genes and discovering deregulated gene modules using simulated data sets. When tested on a series of smoker and non-smoker lung adenocarcinoma data sets, we show that top differentially regulated genes identified by the rank sum test in different sets are not consistent while top ranked genes defined by nDGE in different data sets significantly overlap. nDGE results suggest that a differentially regulated gene module, which is enriched for cell cycle related genes and E2F1 targeted genes, plays a role in the molecular differences between smoker and non-smoker lung adenocarcinoma. Conclusions In this paper, we develop nDGE to prioritize deregulated genes and group them into gene modules by simultaneously considering gene expression level changes and gene-gene co-regulations. When applied to both simulated and empirical data, nDGE outperforms the traditional DGE method. More specifically, when applied to smoker and non-smoker lung cancer sets, nDGE results illustrate the molecular differences between smoker and non-smoker lung cancer. PMID:24341432

JAK2-V617F-induced MAPK activity is regulated by PI3K and acts synergistically with PI3K on the proliferation of JAK2-V617F-positive cells

PubMed Central

Wolf, Alexandra; Eulenfeld, René; Gäbler, Karoline; Rolvering, Catherine; Haan, Serge; Behrmann, Iris; Denecke, Bernd; Haan, Claude; Schaper, Fred

2013-01-01

The identification of a constitutively active JAK2 mutant, namely JAK2-V617F, was a milestone in the understanding of Philadelphia chromosome-negative myeloproliferative neoplasms. The JAK2-V617F mutation confers cytokine hypersensitivity, constitutive activation of the JAK-STAT pathway, and cytokine-independent growth. In this study we investigated the mechanism of JAK2-V617F-dependent signaling with a special focus on the activation of the MAPK pathway. We observed JAK2-V617F-dependent deregulated activation of the multi-site docking protein Gab1 as indicated by constitutive, PI3K-dependent membrane localization and tyrosine phosphorylation of Gab1. Furthermore, we demonstrate that PI3K signaling regulates MAPK activation in JAK2-V617F-positve cells. This cross-regulation of the MAPK pathway by PI3K affects JAK2-V617F-specific target gene induction, erythroid colony formation, and regulates proliferation of JAK2-V617F-positive patient cells in a synergistically manner. PMID:24069558

Gene expression profiling: cell cycle deregulation and aneuploidy do not cause breast cancer formation in WAP-SVT/t transgenic animals.

PubMed

Klein, Andreas; Guhl, Eva; Zollinger, Raphael; Tzeng, Yin-Jeh; Wessel, Ralf; Hummel, Michael; Graessmann, Monika; Graessmann, Adolf

2005-05-01

Microarray studies revealed that as a first hit the SV40 T/t antigen causes deregulation of 462 genes in mammary gland cells (ME cells) of WAP-SVT/t transgenic animals. The majority of deregulated genes are cell proliferation specific and Rb-E2F dependent, causing ME cell proliferation and gland hyperplasia but not breast cancer formation. In the breast tumor cells a further 207 genes are differentially expressed, most of them belonging to the cell communication category. In tissue culture breast tumor cells frequently switch off WAP-SVT/t transgene expression and regain the morphology and growth characteristics of normal ME cells, although the tumor-revertant cells are aneuploid and only 114 genes regain the expression level of normal ME cells. The profile of retransformants shows that only 38 deregulated genes are tumor-specific, and that none of them is considered to be a typical breast cancer gene.

Reengineering of the feedback-inhibition enzyme N-acetyl-L-glutamate kinase to enhance L-arginine production in Corynebacterium crenatum.

PubMed

Zhang, Jingjing; Xu, Meijuan; Ge, Xiaoxun; Zhang, Xian; Yang, Taowei; Xu, Zhenghong; Rao, Zhiming

2017-02-01

N-acetyl-L-glutamate kinase (NAGK) catalyzes the second step of L-arginine biosynthesis and is inhibited by L-arginine in Corynebacterium crenatum. To ascertain the basis for the arginine sensitivity of CcNAGK, residue E19 which located at the entrance of the Arginine-ring was subjected to site-saturated mutagenesis and we successfully illustrated the inhibition-resistant mechanism. Typically, the E19Y mutant displayed the greatest deregulation of L-arginine feedback inhibition. An equally important strategy is to improve the catalytic activity and thermostability of CcNAGK. For further strain improvement, we used site-directed mutagenesis to identify mutations that improve CcNAGK. Results identified variants I74V, F91H and K234T display higher specific activity and thermostability. The L-arginine yield and productivity of the recombinant strain C. crenatum SYPA-EH3 (which possesses a combination of all four mutant sites, E19Y/I74V/F91H/K234T) reached 61.2 and 0.638 g/L/h, respectively, after 96 h in 5 L bioreactor fermentation, an increase of approximately 41.8% compared with the initial strain.

Disruption of the G1/S Transition in Human Papillomavirus Type 16 E7-Expressing Human Cells Is Associated with Altered Regulation of Cyclin E

PubMed Central

Martin, Larry G.; Demers, G. William; Galloway, Denise A.

1998-01-01

The development of neoplasia frequently involves inactivation of the p53 and retinoblastoma (Rb) tumor suppressor pathways and disruption of cell cycle checkpoints that monitor the integrity of replication and cell division. The human papillomavirus type 16 (HPV-16) oncoproteins, E6 and E7, have been shown to bind p53 and Rb, respectively. To further delineate the mechanisms by which E6 and E7 affect cell cycle control, we examined various aspects of the cell cycle machinery. The low-risk HPV-6 E6 and E7 proteins did not cause any significant change in the levels of cell cycle proteins analyzed. HPV-16 E6 resulted in very low levels of p53 and p21 and globally elevated cyclin-dependent kinase (CDK) activity. In contrast, HPV-16 E7 had a profound effect on several aspects of the cell cycle machinery. A number of cyclins and CDKs were elevated, and despite the elevation of the levels of at least two CDK inhibitors, p21 and p16, CDK activity was globally increased. Most strikingly, cyclin E expression was deregulated both transcriptionally and posttranscriptionally and persisted at high levels in S and G2/M. Transit through G1 was shortened by the premature activation of cyclin E-associated kinase activity. Elevation of cyclin E levels required both the CR1 and CR2 domains of E7. These data suggest that cyclin E may be a critical target of HPV-16 E7 in the disruption of G1/S cell cycle progression and that the ability of E7 to regulate cyclin E involves activities in addition to the release of E2F. PMID:9444990

Effect of Deregulation in the Telecommunications Industry on Military Base Telephone Communications.

DTIC Science & Technology

1983-03-01

a s stell11 n=etwcrk in srder to antar -,nt, the long d iS -c s market - In addiio n co he z ccal I e 1eph one ma~ke=t *whcre_ : ow opi:ates. Other...ra n out. By 1910 +he i-ndzp=-dans: (%:Dn-Bell) ele- ph.-one companias accounted fc=r. ne ar=l"y h ..f o f th4 - eieohcrn, * market , anI rates had...vazious ?ffc---;s of tne3 challz-cqers to ant er the stablished markets of thh, commcM Car:4=erS. 2 DurJig te thirties and f3_ i s s, t:hs only s

p53-repressed miRNAs are involved with E2F in a feed-forward loop promoting proliferation

PubMed Central

Brosh, Ran; Shalgi, Reut; Liran, Atar; Landan, Gilad; Korotayev, Katya; Nguyen, Giang Huong; Enerly, Espen; Johnsen, Hilde; Buganim, Yosef; Solomon, Hilla; Goldstein, Ido; Madar, Shalom; Goldfinger, Naomi; Børresen-Dale, Anne-Lise; Ginsberg, Doron; Harris, Curtis C; Pilpel, Yitzhak; Oren, Moshe; Rotter, Varda

2008-01-01

Normal cell growth is governed by a complicated biological system, featuring multiple levels of control, often deregulated in cancers. The role of microRNAs (miRNAs) in the control of gene expression is now increasingly appreciated, yet their involvement in controlling cell proliferation is still not well understood. Here we investigated the mammalian cell proliferation control network consisting of transcriptional regulators, E2F and p53, their targets and a family of 15 miRNAs. Indicative of their significance, expression of these miRNAs is downregulated in senescent cells and in breast cancers harboring wild-type p53. These miRNAs are repressed by p53 in an E2F1-mediated manner. Furthermore, we show that these miRNAs silence antiproliferative genes, which themselves are E2F1 targets. Thus, miRNAs and transcriptional regulators appear to cooperate in the framework of a multi-gene transcriptional and post-transcriptional feed-forward loop. Finally, we show that, similarly to p53 inactivation, overexpression of representative miRNAs promotes proliferation and delays senescence, manifesting the detrimental phenotypic consequence of perturbations in this circuit. Taken together, these findings position miRNAs as novel key players in the mammalian cellular proliferation network. PMID:19034270

Molecular Mechanism of Nkx3.1 Deregulation and its Function in Murine Pten Prostate Cancer Model

DTIC Science & Technology

2006-09-01

of transfected 293T cells using total protein lysate (Figure 2B, upper row in the right panel) or eGFP-sorted cells (Figure 2B, middle row in the...through an AR-dependent mechanism A: NKX3.1 regulates AR transcription and re- duces AKT phosphorylation in vitro. Total RNA and protein were...resulting in de- creased total p53 protein level (compare lanes 1 and 2 of Figure 6F). In contrast, coexpressing Nkx3.1 reduces p53- HDAC1 association

HABP2 p.G534E variant in patients with family history of thyroid and breast cancer

PubMed Central

Pinheiro, Maisa; Drigo, Sandra Aparecida; Tonhosolo, Renata; Andrade, Sonia C.S.; Marchi, Fabio Albuquerque; Jurisica, Igor; Kowalski, Luiz Paulo; Achatz, Maria Isabel; Rogatto, Silvia Regina

2017-01-01

Familial Papillary Thyroid Carcinoma (PTC) has been described as a hereditary predisposition cancer syndrome associated with mutations in candidate genes including HABP2. Two of 20 probands from families with history of PTC and breast carcinoma (BC) were evaluated by whole exome sequencing (WES) revealing HABP2 p.G534E. Sanger sequencing was used to confirm the involvement of this variant in three families (F1: 7 relatives; F2: 3 and F3: 3). The proband and his sister (with no malignant tumor so far) from F1 were homozygous for the variant whereas one relative with PTC from F2 was negative for the variant. Although the proband of the F3 with PTC was HABP2 wild type, three relatives presented the variant. Five of 170 healthy Brazilian individuals with no family history of BC or PTC and three of 50 sporadic PTC presented the p.G534E. These findings suggested no association of this variant with our familial PTC cases. Genes potentially associated with deregulation of the extracellular matrix organization pathway (CTSB, TNXB, COL4A3, COL16A1, COL24A1, COL5A2, NID1, LOXL2, MMP11, TRIM24 and MUSK) and DNA repair function (NBN and MSH2) were detected by WES, suggesting that other cancer-associated genes have pathogenic effects in the risk of familial PTC development. PMID:28402931

Testing the effectiveness of deregulation in the electric utility industry: A market-based approach

NASA Astrophysics Data System (ADS)

Wang, Manfen

In this paper, I investigate one stated purpose of deregulation in the electric utility industry---to make utility operations more responsive to news releases, a proxy for market forces. My premise is that utilities providing electricity to highly deregulated states will be more responsive to market forces than those providing electricity to non-deregulated states. I employ intraday data from April to June 2001, the year after deregulation, and from 1994, the year before deregulation. I also employ the Brown-Forsythe-Modified Levene (BFL) test to determine the volatility differences between days with released news and days without released news. The results of BFL F tests for the year 2001 indicate that utilities headquartered in and serving states that have undergone substantial deregulation respond to news releases more strongly than those utilities headquartered in and serving states that are still regulated. The BFL F tests for utilities in 1994 confirm the premise that regulated utilities are less responsive to news releases. Finally, I conduct regression tests for utilities, the results of which support the findings from BFL tests---that all utilities serving highly deregulated states show pronounced responses to macroeconomic news releases. It appears that deregulation in the electric utility industry does, in fact, make utility operations more responsive to market forces and that deregulation is effective for states that implement a customer-choice model.

Deregulated expression of p16INK4a and p53 pathway members in benign and malignant myoepithelial tumours of the salivary glands.

PubMed

Vékony, H; Röser, K; Löning, T; Raaphorst, F M; Leemans, C R; Van der Waal, I; Bloemena, E

2008-12-01

Myoepithelial salivary gland tumours are uncommon and follow an unpredictable biological course. The aim was to examine their molecular background to acquire a better understanding of their clinical behaviour. Expression of protein (E2F1, p16(INK4a), p53, cyclin D1, Ki67 and Polycomb group proteins BMI-1, MEL-18 and EZH2) was investigated in 49 benign and 30 primary malignant myoepithelial tumours and five histologically benign recurrences by immunohistochemistry and the findings correlated with histopathological characteristics. Benign tumours showed a higher percentage of cells with expression of p16(INK4a) pathway members [p16(INK4a) and E2F1 (both P < 0.001), and cyclin D1, P = 0.002] compared with normal salivary gland. Furthermore, malignant tumours expressed p53 (P = 0.003) and EZH2 (P = 0.09) in a higher percentage. Recurrences displayed more p53 + tumour cells (P = 0.02) than benign primaries. Amongst the benign tumours, the clear cell type had the highest proliferation fraction (P = 0.05) and a higher percentage of EZH2 was detected in the plasmacytoid cell type (P = 0.002). This study is the first to demonstrate that deregulation of the p16(INK4a) senescence pathway is involved in the development of myoepithelial tumours. We propose that additional inactivation of p53 in malignant primaries and benign recurrences contributes to myoepithelial neoplastic transformation and aggressive tumour growth.

Differential antioxidant defense and detoxification mechanisms in photodynamically stressed rice plants treated with the deregulators of porphyrin biosynthesis, 5-aminolevulinic acid and oxyfluorfen

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

Phung, Thu-Ha; Jung, Sunyo, E-mail: sjung@knu.ac.kr

This study focuses on differential molecular mechanisms of antioxidant and detoxification systems in rice plants under two different types of photodynamic stress imposed by porphyrin deregulators, 5-aminolevulinic acid (ALA) and oxyfluorfen (OF). The ALA-treated plants with white necrosis exhibited a greater decrease in photochemical quantum efficiency, F{sub v}/F{sub m}, as well as a greater increase in activity of superoxide dismutase, compared to the OF-treated plants. By contrast, the brown necrosis in OF-treated plants resulted in not only more widely dispersed H{sub 2}O{sub 2} production and greater increases in H{sub 2}O{sub 2}-decomposing enzymes, catalase and peroxidase, but also lower ascorbate redoxmore » state. In addition, ALA- and OF-treated plants markedly up-regulated transcript levels of genes involved in detoxification processes including transport and movement, cellular homeostasis, and xenobiotic conjugation, with prominent up-regulation of serine/threonine kinase and chaperone only in ALA-treated plants. Our results demonstrate that different photodynamic stress imposed by ALA and OF developed differential actions of antioxidant enzymes and detoxification. Particularly, detoxification system may play potential roles in plant protection against photodynamic stress imposed by porphyrin deregulators, thereby contributing to alleviation of photodynamic damage. - Highlights: • We employ two different types of photodynamic stress, white and brown necrosis. • We examine molecular mechanisms of antioxidative and detoxification systems. • ALA and OF develop differential actions of antioxidant and detoxification systems. • Coordinated mechanism of antioxidants and detoxification works against toxic ROS. • Detoxification system plays critical roles in protection against photodynamic stress.« less

WAVE3 is a Biomarker for Breast Cancer Progression and Metastasis

DTIC Science & Technology

2012-04-01

insure reproducibility of the results. f) Repeat tasks a to e for the specimens with questionable results. Completed. See below Task 7: A BC TMA...miRs 570, 542, 103, 107 and 302, all of which have been found to be deregulated during cancer progression and metastasis [26,33,39–44], therefore

Transforming properties of Felis catus papillomavirus type 2 E6 and E7 putative oncogenes in vitro and their transcriptional activity in feline squamous cell carcinoma in vivo

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

Altamura, Gennaro, E-mail: gennaro.altamura@unina.it; Corteggio, Annunziata, E-mail: ancorteg@unina.it; Pacini, Laura, E-mail: PaciniL@students.iarc.fr

Felis catus papillomavirus type 2 (FcaPV2) DNA is found in feline cutaneous squamous cell carcinomas (SCCs); however, its biological properties are still uncharacterized. In this study, we successfully expressed FcaPV2 E6 and E7 putative oncogenes in feline epithelial cells and demonstrated that FcaPV2 E6 binds to p53, impairing its protein level. In addition, E6 and E7 inhibited ultraviolet B (UVB)-triggered accumulation of p53, p21 and pro-apoptotic markers such as Cleaved Caspase3, Bax and Bak, suggesting a synergistic action of the virus with UV exposure in tumour pathogenesis. Furthermore, FcaPV2 E7 bound to feline pRb and impaired pRb levels, resulting inmore » upregulation of the downstream pro-proliferative genes Cyclin A and Cdc2. Importantly, we demonstrated mRNA expression of FcaPV2 E2, E6 and E7 in feline SCC samples, strengthening the hypothesis of a causative role in the development of feline SCC. - Highlights: • FcaPV2 E6 binds to and deregulates feline p53 protein. • FcaPV2 E7 binds to and deregulates feline pRb protein. • FcaPV2 oncogenes inhibit UVB-induced apoptosis. • FcaPV2 E6E7 and E7 increase the lifespan of primary cells. • FcaPV2 E2, E6 and E7 are expressed at the mRNA level in feline SCC in vivo.« less

Effects of dipotassium-trioxohydroxytetrafluorotriborate, K2[B3O3F4OH], on cell viability and gene expression of common human cancer drug targets in a melanoma cell line.

PubMed

Pojskic, Lejla; Haveric, Sanin; Lojo-Kadric, Naida; Hadzic, Maida; Haveric, Anja; Galic, Zoran; Galic, Borivoj; Vullo, Daniela; Supuran, Claudiu T; Milos, Mladen

2016-12-01

Recently it was found that dipotassium-trioxohydroxytetrafluorotriborate, K2(B3O3F4OH), is a potent and highly specific inhibitor of precancerous cell processes. We conducted gene expression profiling of human melanoma cells before and after treatment with two concentrations (0.1 and 1 mM) of this boron inorganic derivative in order to assess its effects on deregulation of genes associated with tumor pathways. Parallel trypan blue exclusion assay was performed to assess the cytotoxicity effects of this chemical. Treatment with K2(B3O3F4OH) induced a significant decrease of cell viability in melanoma cellline at both tested concentrations. Furthermore, these treatments caused deregulation of more than 30 genes known as common anti-tumor drug targets. IGF-1 and hTERT were found to be significantly downregulated and this result may imply potential use of K2(B3O3F4OH) as an inhibitor or human telomerase and insulin-like growth factor 1, both of which are associated with various tumor pathways.

Differential Processing of Propeptide Inhibitors of Rap Phosphatases in Bacillus subtilis†

PubMed Central

Jiang, Min; Grau, Roberto; Perego, Marta

2000-01-01

In the phosphorelay signal transduction system for sporulation initiation in Bacillus subtilis, the opposing activities of histidine kinases and aspartyl phosphate phosphatases determine the cell's decision whether to continue with vegetative growth or to initiate the differentiation process. Regulated dephosphorylation of the Spo0A and Spo0F response regulators allows a variety of negative signals from physiological processes that are antithetical to sporulation to impact on the activation level of the phosphorelay. Spo0F∼P is the known target of two related phosphatases, RapA and RapB. In addition to RapA and RapB, a third member of the Rap family of phosphatases, RapE, specifically dephosphorylated the Spo0F∼P intermediate in response to competence development. RapE phosphatase activity was found to be controlled by a pentapeptide (SRNVT) generated from within the carboxy-terminal domain of the phrE gene product. A synthetic PhrE pentapeptide could (i) complement the sporulation deficiency caused by deregulated RapE activity of a phrE mutant and (ii) inhibit RapE-dependent dephosphorylation of Spo0F∼P in in vitro experiments. The PhrE pentapeptide did not inhibit the phosphatase activity of RapA and RapB. These results confirm previous conclusions that the specificity for recognition of the target phosphatase is contained within the amino acid sequence of the pentapeptide inhibitor. PMID:10629174

LMW-E/CDK2 Deregulates Acinar Morphogenesis, Induces Tumorigenesis, and Associates with the Activated b-Raf-ERK1/2-mTOR Pathway in Breast Cancer Patients

PubMed Central

Duong, MyLinh T.; Akli, Said; Wei, Caimiao; Wingate, Hannah F.; Liu, Wenbin; Lu, Yiling; Yi, Min; Mills, Gordon B.; Hunt, Kelly K.; Keyomarsi, Khandan

2012-01-01

Elastase-mediated cleavage of cyclin E generates low molecular weight cyclin E (LMW-E) isoforms exhibiting enhanced CDK2–associated kinase activity and resistance to inhibition by CDK inhibitors p21 and p27. Approximately 27% of breast cancers express high LMW-E protein levels, which significantly correlates with poor survival. The objective of this study was to identify the signaling pathway(s) deregulated by LMW-E expression in breast cancer patients and to identify pharmaceutical agents to effectively target this pathway. Ectopic LMW-E expression in nontumorigenic human mammary epithelial cells (hMECs) was sufficient to generate xenografts with greater tumorigenic potential than full-length cyclin E, and the tumorigenicity was augmented by in vivo passaging. However, cyclin E mutants unable to interact with CDK2 protected hMECs from tumor development. When hMECs were cultured on Matrigel, LMW-E mediated aberrant acinar morphogenesis, including enlargement of acinar structures and formation of multi-acinar complexes, as denoted by reduced BIM and elevated Ki67 expression. Similarly, inducible expression of LMW-E in transgenic mice generated hyper-proliferative terminal end buds resulting in enhanced mammary tumor development. Reverse-phase protein array assay of 276 breast tumor patient samples and cells cultured on monolayer and in three-dimensional Matrigel demonstrated that, in terms of protein expression profile, hMECs cultured in Matrigel more closely resembled patient tissues than did cells cultured on monolayer. Additionally, the b-Raf-ERK1/2-mTOR pathway was activated in LMW-E–expressing patient samples, and activation of this pathway was associated with poor disease-specific survival. Combination treatment using roscovitine (CDK inhibitor) plus either rapamycin (mTOR inhibitor) or sorafenib (a pan kinase inhibitor targeting b-Raf) effectively prevented aberrant acinar formation in LMW-E–expressing cells by inducing G1/S cell cycle arrest. LMW-E requires CDK2–associated kinase activity to induce mammary tumor formation by disrupting acinar development. The b-Raf-ERK1/2-mTOR signaling pathway is aberrantly activated in breast cancer and can be suppressed by combination treatment with roscovitine plus either rapamycin or sorafenib. PMID:22479189

JAK2 inhibitor therapy in myeloproliferative disorders: rationale, preclinical studies and ongoing clinical trials.

PubMed

Pardanani, A

2008-01-01

The recent identification of somatic mutations such as JAK2V617F that deregulate Janus kinase (JAK)-signal transducer and activator of transcription signaling has spurred development of orally bioavailable small-molecule inhibitors that selectively target JAK2 kinase as an approach to pathogenesis-directed therapy of myeloproliferative disorders (MPD). In pre-clinical studies, these compounds inhibit JAK2V617F-mediated cell growth at nanomolar concentrations, and in vivo therapeutic efficacy has been demonstrated in mouse models of JAK2V617F-induced disease. In addition, ex vivo growth of progenitor cells from MPD patients harboring JAK2V617F or MPLW515L/K mutations is also potently inhibited. JAK2 inhibitors currently in clinical trials can be grouped into those designed to primarily target JAK2 kinase (JAK2-selective) and those originally developed for non-MPD indications, but that nevertheless have significant JAK2-inhibitory activity (non-JAK2 selective). This article discusses the rationale for using JAK2 inhibitors for the treatment of MPD, as well as relevant aspects of clinical trial development for these patients. For instance, which group of MPD patients is appropriate for initial Phase I studies? Should JAK2V617F-negative MPD patients be included in the initial studies? What are the likely consequences of 'off-target' JAK3 and wild-type JAK2 inhibition? How should treatment responses be monitored?

E2f1–3 Are Critical for Myeloid Development*

PubMed Central

Trikha, Prashant; Sharma, Nidhi; Opavsky, Rene; Reyes, Andres; Pena, Clarissa; Ostrowski, Michael C.; Roussel, Martine F.; Leone, Gustavo

2011-01-01

Hematopoietic development involves the coordinated activity of differentiation and cell cycle regulators. In current models of mammalian cell cycle control, E2f activators (E2f1, E2f2, and E2f3) are portrayed as the ultimate transcriptional effectors that commit cells to enter and progress through S phase. Using conditional gene knock-out strategies, we show that E2f1–3 are not required for the proliferation of early myeloid progenitors. Rather, these E2fs are critical for cell survival and proliferation at two distinct steps of myeloid development. First, E2f1–3 are required as transcriptional repressors for the survival of CD11b+ myeloid progenitors, and then they are required as activators for the proliferation of CD11b+ macrophages. In bone marrow macrophages, we show that E2f1–3 respond to CSF1-Myc mitogenic signals and serve to activate E2f target genes and promote their proliferation. Together, these findings expose dual functions for E2f1–3 at distinct stages of myeloid development in vivo, first as repressors in cell survival and then as activators in cell proliferation. In summary, this work places E2f1–3 in a specific signaling cascade that is critical for myeloid development in vivo. PMID:21115501

Calpains are downstream effectors of bax-dependent excitotoxic apoptosis.

PubMed

D'Orsi, Beatrice; Bonner, Helena; Tuffy, Liam P; Düssmann, Heiko; Woods, Ina; Courtney, Michael J; Ward, Manus W; Prehn, Jochen H M

2012-02-01

Excitotoxicity resulting from excessive Ca(2+) influx through glutamate receptors contributes to neuronal injury after stroke, trauma, and seizures. Increased cytosolic Ca(2+) levels activate a family of calcium-dependent proteases with papain-like activity, the calpains. Here we investigated the role of calpain activation during NMDA-induced excitotoxic injury in embryonic (E16-E18) murine cortical neurons that (1) underwent excitotoxic necrosis, characterized by immediate deregulation of Ca(2+) homeostasis, a persistent depolarization of mitochondrial membrane potential (Δψ(m)), and insensitivity to bax-gene deletion, (2) underwent excitotoxic apoptosis, characterized by recovery of NMDA-induced cytosolic Ca(2+) increases, sensitivity to bax gene deletion, and delayed Δψ(m) depolarization and Ca(2+) deregulation, or (3) that were tolerant to excitotoxic injury. Interestingly, treatment with the calpain inhibitor calpeptin, overexpression of the endogenous calpain inhibitor calpastatin, or gene silencing of calpain protected neurons against excitotoxic apoptosis but did not influence excitotoxic necrosis. Calpeptin failed to exert a protective effect in bax-deficient neurons but protected bid-deficient neurons similarly to wild-type cells. To identify when calpains became activated during excitotoxic apoptosis, we monitored calpain activation dynamics by time-lapse fluorescence microscopy using a calpain-sensitive Förster resonance energy transfer probe. We observed a delayed calpain activation that occurred downstream of mitochondrial engagement and directly preceded neuronal death. In contrast, we could not detect significant calpain activity during excitotoxic necrosis or in neurons that were tolerant to excitotoxic injury. Oxygen/glucose deprivation-induced injury in organotypic hippocampal slice cultures confirmed that calpains were specifically activated during bax-dependent apoptosis and in this setting function as downstream cell-death executioners.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD)-mediated deregulation of myeloid and sebaceous gland stem/progenitor cell homeostasis.

PubMed

Bock, Karl Walter

2017-06-01

Studies of TCDD toxicity stimulated identification of the responsible aryl hydrocarbon receptor (AHR), a multifunctional, ligand-activated transcription factor of the basic helix-loop-helix/Per-Arnt-Sim family. Accumulating evidence suggests a role of this receptor in homeostasis of stem/progenitor cells, in addition to its known role in xenobiotic metabolism. (1) Regulation of myelopoiesis is complex. As one example, AHR-mediated downregulation of human CD34+ progenitor differentiation to monocytes/macrophages is discussed. (2) Accumulation of TCDD in sebum leads to deregulation of sebocyte differentiation via Blimp1-mediated inhibition of c-Myc signaling and stimulation of Wnt-mediated proliferation of interfollicular epidermis. The resulting sebaceous gland atrophy and formation of dermal cysts may explain the pathogenesis of chloracne, the hallmark of TCDD toxicity. (3) TCDD treatment of confluent liver stem cell-like rat WB-F344 cells leads to release from cell-cell contact inhibition via AHR-mediated crosstalk with multiple signaling pathways. Further work is needed to delineate AHR function in crosstalk with other signaling pathways.

The Aryl Hydrocarbon Receptor Binds to E2F1 and Inhibits E2F1-induced Apoptosis

PubMed Central

Marlowe, Jennifer L.; Fan, Yunxia; Chang, Xiaoqing; Peng, Li; Knudsen, Erik S.; Xia, Ying

2008-01-01

Cellular stress by DNA damage induces checkpoint kinase-2 (CHK2)-mediated phosphorylation and stabilization of the E2F1 transcription factor, leading to induction of apoptosis by activation of a subset of proapoptotic E2F1 target genes, including Apaf1 and p73. This report characterizes an interaction between the aryl hydrocarbon (Ah) receptor (AHR), a ligand-activated transcription factor, and E2F1 that results in the attenuation of E2F1-mediated apoptosis. In Ahr−/− fibroblasts stably transfected with a doxycycline-regulated AHR expression vector, inhibition of AHR expression causes a significant elevation of oxidative stress, γH2A.X histone phosphorylation, and E2F1-dependent apoptosis, which can be blocked by small interfering RNA-mediated knockdown of E2F1 expression. In contrast, ligand-dependent AHR activation protects these cells from etoposide-induced cell death. In cells expressing both proteins, AHR and E2F1 interact independently of the retinoblastoma protein (RB), because AHR and E2F1 coimmunoprecipitate from extracts of RB-negative cells. Additionally, chromatin immunoprecipitation assays indicate that AHR and E2F1 bind to the Apaf1 promoter at a region containing a consensus E2F1 binding site but no AHR binding sites. AHR activation represses Apaf1 and TAp73 mRNA induction by a constitutively active CHK2 expression vector. Furthermore, AHR overexpression blocks the transcriptional induction of Apaf1 and p73 and the accumulation of sub-G0/G1 cells resulting from ectopic overexpression of E2F1. These results point to a proproliferative, antiapoptotic function of the Ah receptor that likely plays a role in tumor progression. PMID:18524851

Census of U.S. Civil Aircraft, Calendar Year 1980.

DTIC Science & Technology

1980-12-31

This increase is partly due to the deregulation of the airlines under the Airline Deregulation Act of 1978 and the associated entry of new carriers. The... ASSOCIATES 2 --- --- ---. 2 AIR MAINI, INC. 9 --- --- ... 1 8 AIR NEBRASKA, INC- 2 --- -- I AIR NEVADA AIRLINES 9 --- --- --- -- AIR NORTH I...12 -" MONTAUK CARIBBEAN AIRWAYS 3 . I - 2 MOUNTAIN HOmE AIR SERVICE 1 . .. .. .. 1 MOUNTAIN WEST AIRLINES 3 - - 2 1 /uNZ NORTHERN AIRLINES, INC

Arginine methylation-dependent reader-writer interplay governs growth control by E2F-1

PubMed Central

Zheng, Shunsheng; Moehlenbrink, Jutta; Lu, Yi-Chien; Zalmas, Lykourgos-Panagiotis; Sagum, Cari A.; Carr, Simon; McGouran, Joanna F.; Alexander, Leila; Fedorov, Oleg; Munro, Shonagh; Kessler, Benedikt; Bedford, Mark T.; Yu, Qiang; La Thangue, Nicholas B.

2014-01-01

Summary The mechanisms that underlie and dictate the different biological outcomes of E2F-1 activity have yet to be elucidated. We describe the residue-specific methylation of E2F-1 by the asymmetric dimethylating protein arginine methyltransferase (PRMT) 1 and symmetric dimethylating PRMT5, and relate the marks to different functional consequences of E2F-1 activity. Methylation by PRMT1 hinders methylation by PRMT5, which augments E2F-1-dependent apoptosis, whereas PRMT5-dependent methylation favours proliferation by antagonising methylation by PRMT1. The ability of E2F-1 to prompt apoptosis in DNA damaged cells coincides with enhanced PRMT1 methylation. In contrast, cyclin A binding to E2F-1 impedes PRMT1 methylation and augments PRMT5 methylation, thus ensuring that E2F-1 is locked into its cell cycle progression mode. The Tudor domain protein p100-TSN reads the symmetric methylation mark, and binding of p100-TSN down-regulates E2F-1 apoptotic activity. Our results define an exquisite level of precision in the reader-writer interplay that governs the biological outcome of E2F-1 activity. PMID:24076217

E2F1 promote the aggressiveness of human colorectal cancer by activating the ribonucleotide reductase small subunit M2

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

Fang, Zejun; Gong, Chaoju; Liu, Hong

2015-08-21

As the ribonucleotide reductase small subunit, the high expression of ribonucleotide reductase small subunit M2 (RRM2) induces cancer and contributes to tumor growth and invasion. In several colorectal cancer (CRC) cell lines, we found that the expression levels of RRM2 were closely related to the transcription factor E2F1. Mechanistic studies were conducted to determine the molecular basis. Ectopic overexpression of E2F1 promoted RRM2 transactivation while knockdown of E2F1 reduced the levels of RRM2 mRNA and protein. To further investigate the roles of RRM2 which was activated by E2F1 in CRC, CCK-8 assay and EdU incorporation assay were performed. Overexpression ofmore » E2F1 promoted cell proliferation in CRC cells, which was blocked by RRM2 knockdown attenuation. In the migration and invasion tests, overexpression of E2F1 enhanced the migration and invasion of CRC cells which was abrogated by silencing RRM2. Besides, overexpression of RRM2 reversed the effects of E2F1 knockdown partially in CRC cells. Examination of clinical CRC specimens demonstrated that both RRM2 and E2F1 were elevated in most cancer tissues compared to the paired normal tissues. Further analysis showed that the protein expression levels of E2F1 and RRM2 were parallel with each other and positively correlated with lymph node metastasis (LNM), TNM stage and distant metastasis. Consistently, the patients with low E2F1 and RRM2 levels have a better prognosis than those with high levels. Therefore, we suggest that E2F1 can promote CRC proliferation, migration, invasion and metastasis by regulating RRM2 transactivation. Understanding the role of E2F1 in activating RRM2 transcription will help to explain the relationship between E2F1 and RRM2 in CRC and provide a novel predictive marker for diagnosis and prognosis of the disease. - Highlights: • E2F1 promotes RRM2 transactivation in CRC cells. • E2F1 promotes the proliferation of CRC cells by activating RRM2. • E2F1 promotes the migration and invasion of CRC cells by activating RRM2. • E2F1 is upregulated in CRC tissues and positively associated with RRM2 level. • E2F1-mediated RRM2 transcription will provide a new strategy in CRC.« less

Emerging strategies for EphA2 receptor targeting for cancer therapeutics.

PubMed

Tandon, Manish; Vemula, Sai Vikram; Mittal, Suresh K

2011-01-01

High mortality rates with cancers warrant further development of earlier diagnostics and better treatment strategies. Membrane-bound erythropoietin-producing hepatocellular receptor tyrosine kinase class A2 (EphA2) is overexpressed in breast, prostate, urinary bladder, skin, lung, ovary and brain cancers. EphA2 overexpression in cancers, its signaling mechanisms and strategies to target its deregulation. High EphA2 expression in cancer cells is correlated with a poor prognosis associated with recurrence due to enhanced metastasis. Interaction of the EphA2 receptor with its ligand (e.g., ephrinA1) triggers events that are deregulated and implicated in carcinogenesis. EphrinA1-independent oncogenic activity and ephrinA1-dependent tumor suppressor roles for EphA2 are described. Molecular interactions of EphA2 with signaling proteins are associated with the modulation of cytoskeleton dynamics, cell adhesion, proliferation, differentiation and metastasis. The deregulated signaling by EphA2 and its involvement in oncogenesis provide multiple avenues for the rational design of intervention approaches. EphA2 has been tested as a drug target using multiple approaches such as agonist antibodies, RNA interference, immunotherapy, virus vector-mediated gene transfer, small-molecule inhibitors and nanoparticles. With over a decade of research, encouraging results with targeting of EphA2 expression in various pre-clinical cancer models necessitate further studies.

Therapeutic Strategies Against Cyclin E1 Amplified Ovarian Cancers

DTIC Science & Technology

2017-10-01

interaction will lead to enhancement of RB/E2F interaction and suppression of E2F- dependent oncogenic activity resulting in activity against CCNE1-amplified...relevant for CCNE1-amplified ovarian tumors which are dependent on hyperactive HR and are sensitive to suppression of BRCA1. 15. SUBJECT TERMS Ovarian...enhancement of RB/E2F interaction and suppression of E2F- dependent oncogenic activity resulting in activity against CCNE1-amplified cells. In the third

Census of U.S. Civil Aircraft. Calendar Year 1981.

DTIC Science & Technology

1981-12-31

that for 1978. This increase is partly due to the deregulation of the airlines under the Airline Deregulation Act of 1978 and the associated entry of...4. - AIR t UCY 4 .. ... 4 . .. AIRLIFT ASSOCIATES 2 .. ... ... 2 - AIR Li K 1 ... - I - AIR LOwsTIcS OF ALASKA, IC 4 ... 4 ..... AIR NEV AIRLINES 10...VALLEY 14 ... .... 14 --- -- Mtotu CARIEA AIRWAYS 4 --- ..... 1 2 1 MOUNTAIN HOmE AIR SERVICE 5 --- --- ---. 3 2 --- PMNz NORTHERN AIRLINEs, INC 7

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.

The ras/mitogen-activated protein kinase pathway inhibitor and likely tumor suppressor proteins, sprouty 1 and sprouty 2 are deregulated in breast cancer.

PubMed

Lo, Ting Ling; Yusoff, Permeen; Fong, Chee Wai; Guo, Ke; McCaw, Ben J; Phillips, Wayne A; Yang, He; Wong, Esther Sook Miin; Leong, Hwei Fen; Zeng, Qi; Putti, Thomas Choudary; Guy, Graeme R

2004-09-01

Sprouty (Spry) proteins were found to be endogenous inhibitors of the Ras/mitogen-activated protein kinase pathway that play an important role in the remodeling of branching tissues. We investigated Spry expression levels in various cancers and found that Spry1 and Spry2 were down-regulated consistently in breast cancers. Such prevalent patterns of down-regulation may herald the later application of these isoforms as tumor markers that are breast cancer specific and more profound than currently characterized markers. Spry1 and 2 were expressed specifically in the luminal epithelial cells of breast ducts, with higher expression during stages of tissue remodeling when the epithelial ducts are forming and branching. These findings suggest that Sprys might be involved as a modeling counterbalance and surveillance against inappropriate epithelial expansion. The abrogation of endogenous Spry activity in MCF-7 cells by the overexpression of a previously characterized dominant-negative mutant of Spry, hSpry2Y55F resulted in enhanced cell proliferation in vitro. The hSpry2Y55F stably expressing cells also formed larger and greater number of colonies in the soft-agar assay. An in vivo nude mice assay showed a dramatic increase in the tumorigenic potential of hSpry2Y55F stable cells. The consistent down-regulation of Spry1 and 2 in breast cancer and the experimental evidence using a dominant-negative hSpry2Y55F indicate that Spry proteins may actively maintain tissue integrity that runs amok when their expression is decreased below normal threshold levels. This alludes to a previously unrecognized role for Sprys in cancer development.

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

PubMed

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

2015-11-10

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

ROS Production Is Essential for the Apoptotic Function of E2F1 in Pheochromocytoma and Neuroblastoma Cell Lines

PubMed Central

Espada, Lilia; Meo-Evoli, Nathalie; Sancho, Patricia; Real, Sebastian; Fabregat, Isabel; Ambrosio, Santiago; Tauler, Albert

2012-01-01

In this study we demonstrate that accumulation of reactive oxygen species (ROS) is essential for E2F1 mediated apoptosis in ER-E2F1 PC12 pheochromocytoma, and SH-SY5Y and SK-N-JD neuroblastoma stable cell lines. In these cells, the ER-E2F1 fusion protein is expressed in the cytosol; the addition of 4-hydroxytamoxifen (OHT) induces its translocation to the nucleus and activation of E2F1target genes. Previously we demonstrated that, in ER-E2F1 PC12 cells, OHT treatment induced apoptosis through activation of caspase-3. Here we show that caspase-8 activity did not change upon treatment with OHT. Moreover, over-expression of Bcl-xL arrested OHT-induced apoptosis; by contrast, over-expression of c-FLIP, did not have any effect on OHT-induced apoptosis. OHT addition induces BimL expression, its translocation to mitochondria and activation of Bax, which is paralleled by diminished mitochondrial enrichment of Bcl-xL. Treatment with a Bax-inhibitory peptide reduced OHT-induced apoptosis. These results point out the essential role of mitochondria on the apoptotic process driven by E2F1. ROS accumulation followed E2F1 induction and treatment with the antioxidant N-acetylcysteine, inhibited E2F1-induced Bax translocation to mitochondria and subsequent apoptosis. The role of ROS in mediating OHT-induced apoptosis was also studied in two neuroblastoma cell lines, SH-SY5Y and SK-N-JD. In SH-SY5Y cells, activation of E2F1 by the addition of OHT induced ROS production and apoptosis, whereas over-expression of E2F1 in SK-N-JD cells failed to induce either response. Transcriptional profiling revealed that many of the genes responsible for scavenging ROS were down-regulated following E2F1-induction in SH-SY5Y, but not in SK-N-JD cells. Finally, inhibition of GSK3β blocked ROS production, Bax activation and the down regulation of ROS scavenging genes. These findings provide an explanation for the apparent contradictory role of E2F1 as an apoptotic agent versus a cell cycle activator. PMID:23251571

Emerging strategies for EphA2 receptor targeting for cancer therapeutics

PubMed Central

Tandon, Manish; Vemula, Sai Vikram; Mittal, Suresh K.

2010-01-01

Importance of the field High mortality rates with cancers warrant further development of earlier diagnostics and better treatment strategies. Membrane-bound hepatocellular receptor tyrosine kinase class A2 (EphA2) is overexpressed in breast, prostate, urinary bladder, skin, lung, ovary and brain cancers. Areas covered in this review This review describes EphA2 overexpression in cancers, its signaling mechanisms and strategies to target its deregulation. What will the reader will gain High EphA2 expression in cancer cells is correlated to a poor prognosis associated with recurrence due to enhanced metastasis. Interaction of the EphA2 receptor with its ligand (e.g., EphrinA1) triggers events that are deregulated and implicated in carcinogenesis. Both EphrinA1-independent oncogenic activity and EphrinA1-dependent tumor suppressor roles for EphA2 are described. Molecular interactions of EphA2 with signaling proteins are associated with the modulation of cytoskeleton dynamics, cell adhesion, proliferation, differentiation and metastasis. The deregulated signaling by EphA2 and its involvement in oncogenesis provide multiple avenues for the rational design of intervention approaches. Take home message EphA2 has been tested as a drug target using multiple approaches such as agonist antibodies, RNA interference, immunotherapy, virus vectors-mediated gene transfer, small molecule inhibitors and nanoparticles. With over a decade of research, encouraging results with successful targeting of EphA2 expression in various pre-clinical cancer models necessitate further studies. PMID:21142802

Human papillomavirus 16 E6 modulates the expression of miR-496 in oropharyngeal cancer.

PubMed

Mason, Dayna; Zhang, Xiaoying; Marques, Tânia Monteiro; Rose, Barbara; Khoury, Samantha; Hill, Meredith; Deutsch, Fiona; Lyons, J Guy; Gama-Carvalho, Margarida; Tran, Nham

2018-06-20

Human papillomavirus (HPV), notably type 16, is a risk factor for up to 75% of oropharyngeal squamous cell carcinomas (SCC). It has been demonstrated that small non-coding RNAs known as microRNAs play a vital role in the cellular transformation process. In this study, we used an LNA array to further investigate the impact of HPV16 on the expression of microRNAs in oropharyngeal (tonsillar) cancer. A number of miRNAs were found to be deregulated, with miR-496 showing a four-fold decrease. Over-expression of the high risk E6 oncoprotein down-regulated miR-496, impacting upon the post-transcriptional control of the transcription factor E2F2. These HPV specific miRNAs were integrated with the HPV16 interactome to identify possible mechanistic pathways. These analyses provide insights into novel molecular interactions between HPV16 and miRNAs in oropharyngeal cancers. Copyright © 2018. Published by Elsevier Inc.

Deregulated expression of TANK in glioblastomas triggers pro-tumorigenic ERK1/2 and AKT signaling pathways.

PubMed

Stellzig, J; Chariot, A; Shostak, K; Ismail Göktuna, S; Renner, F; Acker, T; Pagenstecher, A; Schmitz, M L

2013-11-11

Signal transmission by the noncanonical IkappaB kinases (IKKs), TANK-binding kinase 1 (TBK1) and IKKɛ, requires interaction with adapter proteins such as TRAF associated NF-κB activator (TANK). Although increased expression or dysregulation of both kinases has been described for a variety of human cancers, this study shows that deregulated expression of the TANK protein is frequently occurring in glioblastomas (GBMs). The functional relevance of TANK was analyzed in a panel of GBM-derived cell lines and revealed that knockdown of TANK arrests cells in the S-phase and prohibits tumor cell migration. Deregulated TANK expression affects several signaling pathways controlling cell proliferation and the inflammatory response. Interference with stoichiometrically assembled signaling complexes by overexpression or silencing of TANK prevented constitutive interferon-regulatory factor 3 (IRF3) phosphorylation. Knockdown of TANK frequently prevents constitutive activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2). TANK-mediated ERK1/2 activation is independent from the canonical MAP kinase or ERK kinase (MEK) 1/2-mediated pathway and utilizes an alternative pathway that uses a TBK1/IKKɛ/Akt signaling axis, thus identifying a novel pathway suitable to block constitutive ERK1/2 activity.

Deregulated expression of TANK in glioblastomas triggers pro-tumorigenic ERK1/2 and AKT signaling pathways

PubMed Central

Stellzig, J; Chariot, A; Shostak, K; Ismail Göktuna, S; Renner, F; Acker, T; Pagenstecher, A; Schmitz, M L

2013-01-01

Signal transmission by the noncanonical IkappaB kinases (IKKs), TANK-binding kinase 1 (TBK1) and IKKɛ, requires interaction with adapter proteins such as TRAF associated NF-κB activator (TANK). Although increased expression or dysregulation of both kinases has been described for a variety of human cancers, this study shows that deregulated expression of the TANK protein is frequently occurring in glioblastomas (GBMs). The functional relevance of TANK was analyzed in a panel of GBM-derived cell lines and revealed that knockdown of TANK arrests cells in the S-phase and prohibits tumor cell migration. Deregulated TANK expression affects several signaling pathways controlling cell proliferation and the inflammatory response. Interference with stoichiometrically assembled signaling complexes by overexpression or silencing of TANK prevented constitutive interferon-regulatory factor 3 (IRF3) phosphorylation. Knockdown of TANK frequently prevents constitutive activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2). TANK-mediated ERK1/2 activation is independent from the canonical MAP kinase or ERK kinase (MEK) 1/2-mediated pathway and utilizes an alternative pathway that uses a TBK1/IKKɛ/Akt signaling axis, thus identifying a novel pathway suitable to block constitutive ERK1/2 activity. PMID:24217713

DEREGULATION OF DUX4 AND ERG IN ACUTE LYMPHOBLASTIC LEUKEMIA

PubMed Central

Zhang, Jinghui; McCastlain, Kelly; Yoshihara, Hiroki; Xu, Beisi; Chang, Yunchao; Churchman, Michelle L.; Wu, Gang; Li, Yongjin; Wei, Lei; Iacobucci, Ilaria; Liu, Yu; Qu, Chunxu; Wen, Ji; Edmonson, Michael; Payne-Turner, Debbie; Kaufmann, Kerstin B.; Takayanagi, Shin-ichiro; Wienholds, Erno; Waanders, Esmé; Ntziachristos, Panagiotis; Bakogianni, Sofia; Wang, Jingjing; Aifantis, Iannis; Roberts, Kathryn G.; Ma, Jing; Song, Guangchun; Easton, John; Mulder, Heather L.; Chen, Xiang; Newman, Scott; Ma, Xiaotu; Rusch, Michael; Gupta, Pankaj; Boggs, Kristy; Vadodaria, Bhavin; Dalton, James; Liu, Yanling; Valentine, Marcus L; Ding, Li; Lu, Charles; Fulton, Robert S.; Fulton, Lucinda; Tabib, Yashodhan; Ochoa, Kerri; Devidas, Meenakshi; Pei, Deqing; Cheng, Cheng; Yang, Jun; Evans, William E.; Relling, Mary V.; Pui, Ching-Hon; Jeha, Sima; Harvey, Richard C.; Chen, I-Ming L; Willman, Cheryl L.; Marcucci, Guido; Bloomfield, Clara D.; Kohlschmidt, Jessica; Mrózek, Krzysztof; Paietta, Elisabeth; Tallman, Martin S.; Stock, Wendy; Foster, Matthew C.; Racevskis, Janis; Rowe, Jacob M.; Luger, Selina; Kornblau, Steven M.; Shurtleff, Sheila A; Raimondi, Susana C.; Mardis, Elaine R.; Wilson, Richard K.; Dick, John E.; Hunger, Stephen P; Loh, Mignon L.; Downing, James R.; Mullighan, Charles G.

2016-01-01

Chromosomal rearrangements deregulating hematopoietic transcription factors are common in acute lymphoblastic leukemia (ALL).1,2 Here, we show that deregulation of the homeobox transcription factor gene DUX4 and the ETS transcription factor gene ERG are hallmarks of a subtype of B-progenitor ALL that comprises up to 7% of B-ALL. DUX4 rearrangement and overexpression was present in all cases, and was accompanied by transcriptional deregulation of ERG, expression of a novel ERG isoform, ERGalt, and frequent ERG deletion. ERGalt utilizes a non-canonical first exon whose transcription was initiated by DUX4 binding. ERGalt retains the DNA-binding and transactivating domains of ERG, but inhibits wild-type ERG transcriptional activity and is transforming. These results illustrate a unique paradigm of transcription factor deregulation in leukemia, in which DUX4 deregulation results in loss-of-function of ERG, either by deletion or induction of expression of an isoform that is a dominant negative inhibitor of wild type ERG function. PMID:27776115

Lentiviral Nef Proteins Utilize PAK2-Mediated Deregulation of Cofilin as a General Strategy To Interfere with Actin Remodeling▿ †

PubMed Central

Stolp, Bettina; Abraham, Libin; Rudolph, Jochen M.; Fackler, Oliver T.

2010-01-01

Nef is an accessory protein and pathogenicity factor of human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) which elevates virus replication in vivo. We recently described for HIV type 1SF2 (HIV-1SF2) the potent interference of Nef with T-lymphocyte chemotaxis via its association with the cellular kinase PAK2. Mechanistic analysis revealed that this interaction results in deregulation of the actin-severing factor cofilin and thus blocks the chemokine-mediated actin remodeling required for cell motility. However, the efficiency of PAK2 association is highly variable among Nef proteins from different lentiviruses, prompting us to evaluate the conservation of this actin-remodeling/cofilin-deregulating mechanism. Based on the analysis of a total of 17 HIV-1, HIV-2, and SIV Nef proteins, we report here that inhibition of chemokine-induced actin remodeling as well as inactivation of cofilin are strongly conserved activities of lentiviral Nef proteins. Of note, even for Nef variants that display only marginal PAK2 association in vitro, these activities require the integrity of a PAK2 recruitment motif and the presence of endogenous PAK2. Thus, reduced in vitro affinity to PAK2 does not indicate limited functionality of Nef-PAK2 complexes in intact HIV-1 host cells. These results establish hijacking of PAK2 for deregulation of cofilin and inhibition of triggered actin remodeling as a highly conserved function of lentiviral Nef proteins, supporting the notion that PAK2 association may be critical for Nef's activity in vivo. PMID:20147394

Lentiviral Nef proteins utilize PAK2-mediated deregulation of cofilin as a general strategy to interfere with actin remodeling.

PubMed

Stolp, Bettina; Abraham, Libin; Rudolph, Jochen M; Fackler, Oliver T

2010-04-01

Nef is an accessory protein and pathogenicity factor of human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) which elevates virus replication in vivo. We recently described for HIV type 1(SF2) (HIV-1(SF2)) the potent interference of Nef with T-lymphocyte chemotaxis via its association with the cellular kinase PAK2. Mechanistic analysis revealed that this interaction results in deregulation of the actin-severing factor cofilin and thus blocks the chemokine-mediated actin remodeling required for cell motility. However, the efficiency of PAK2 association is highly variable among Nef proteins from different lentiviruses, prompting us to evaluate the conservation of this actin-remodeling/cofilin-deregulating mechanism. Based on the analysis of a total of 17 HIV-1, HIV-2, and SIV Nef proteins, we report here that inhibition of chemokine-induced actin remodeling as well as inactivation of cofilin are strongly conserved activities of lentiviral Nef proteins. Of note, even for Nef variants that display only marginal PAK2 association in vitro, these activities require the integrity of a PAK2 recruitment motif and the presence of endogenous PAK2. Thus, reduced in vitro affinity to PAK2 does not indicate limited functionality of Nef-PAK2 complexes in intact HIV-1 host cells. These results establish hijacking of PAK2 for deregulation of cofilin and inhibition of triggered actin remodeling as a highly conserved function of lentiviral Nef proteins, supporting the notion that PAK2 association may be critical for Nef's activity in vivo.

TRIP-Br2 promotes oncogenesis in nude mice and is frequently overexpressed in multiple human tumors

PubMed Central

Cheong, Jit Kong; Gunaratnam, Lakshman; Zang, Zhi Jiang; Yang, Christopher M; Sun, Xiaoming; Nasr, Susan L; Sim, Khe Guan; Peh, Bee Keow; Rashid, Suhaimi Bin Abdul; Bonventre, Joseph V; Salto-Tellez, Manuel; Hsu, Stephen I

2009-01-01

Background Members of the TRIP-Br/SERTAD family of mammalian transcriptional coregulators have recently been implicated in E2F-mediated cell cycle progression and tumorigenesis. We, herein, focus on the detailed functional characterization of the least understood member of the TRIP-Br/SERTAD protein family, TRIP-Br2 (SERTAD2). Methods Oncogenic potential of TRIP-Br2 was demonstrated by (1) inoculation of NIH3T3 fibroblasts, which were engineered to stably overexpress ectopic TRIP-Br2, into athymic nude mice for tumor induction and (2) comprehensive immunohistochemical high-throughput screening of TRIP-Br2 protein expression in multiple human tumor cell lines and human tumor tissue microarrays (TMAs). Clinicopathologic analysis was conducted to assess the potential of TRIP-Br2 as a novel prognostic marker of human cancer. RNA interference of TRIP-Br2 expression in HCT-116 colorectal carcinoma cells was performed to determine the potential of TRIP-Br2 as a novel chemotherapeutic drug target. Results Overexpression of TRIP-Br2 is sufficient to transform murine fibroblasts and promotes tumorigenesis in nude mice. The transformed phenotype is characterized by deregulation of the E2F/DP-transcriptional pathway through upregulation of the key E2F-responsive genes CYCLIN E, CYCLIN A2, CDC6 and DHFR. TRIP-Br2 is frequently overexpressed in both cancer cell lines and multiple human tumors. Clinicopathologic correlation indicates that overexpression of TRIP-Br2 in hepatocellular carcinoma is associated with a worse clinical outcome by Kaplan-Meier survival analysis. Small interfering RNA-mediated (siRNA) knockdown of TRIP-Br2 was sufficient to inhibit cell-autonomous growth of HCT-116 cells in vitro. Conclusion This study identifies TRIP-Br2 as a bona-fide protooncogene and supports the potential for TRIP-Br2 as a novel prognostic marker and a chemotherapeutic drug target in human cancer. PMID:19152710

Functional synergy between DP-1 and E2F-1 in the cell cycle-regulating transcription factor DRTF1/E2F.

PubMed Central

Bandara, L R; Buck, V M; Zamanian, M; Johnston, L H; La Thangue, N B

1993-01-01

It is widely believed that the cellular transcription factor DRTF1/E2F integrates cell cycle events with the transcription apparatus because during cell cycle progression in mammalian cells it interacts with molecules that are important regulators of cellular proliferation, such as the retinoblastoma tumour suppressor gene product (pRb), p107, cyclins and cyclin-dependent kinases. Thus, pRb, which negatively regulates early cell cycle progression and is frequently mutated in tumour cells, and the Rb-related protein p107, bind to and repress the transcriptional activity of DRTF1/E2F. Viral oncoproteins, such as adenovirus E1a and SV40 large T antigen, overcome such repression by sequestering pRb and p107 and in so doing are likely to activate genes regulated by DRTF1/E2F, such as cdc2, c-myc and DHFR. Two sequence-specific DNA binding proteins, E2F-1 and DP-1, which bind to the E2F site, contain a small region of similarity. The functional relationship between them has, however, been unclear. We report here that DP-1 and E2F-1 exist in a DNA binding complex in vivo and that they bind efficiently and preferentially as a heterodimer to the E2F site. Moreover, studies in yeast and Drosophila cells indicate that DP-1 and E2F-1 interact synergistically in E2F site-dependent transcriptional activation. Images PMID:8223441

E2F8 as a Novel Therapeutic Target for Lung Cancer

PubMed Central

Park, Sin-Aye; Platt, James; Lee, Jong Woo; López-Giráldez, Francesc; Herbst, Roy S.

2015-01-01

Background: The E2F members have been divided into transcription activators (E2F1-E2F3) and repressors (E2F4-E2F8). E2F8 with E2F7 has been known to play an important physiologic role in embryonic development and cell cycle regulation by repressing E2F1. However, the function of E2F8 in cancer cells is unknown. Methods: E2F8 expression was assessed by immunoblotting or immunofluorescence staining in human lung cancer (LC) cells and tissues from LC patients (n = 45). Cell proliferation, colony formation, and invasion analysis were performed to evaluate the role of E2F8 in LC. Microarray analysis was used to determine the target genes of E2F8. The regulation of E2F8 on the expression of ubiquitin-like PHD and RING domain-containing 1 (UHRF1), one of E2F8 target genes, was determined using chromatin immunoprecipitation and promoter activity assays. Human LC xenograft models were used to determine the effects of inhibiting E2F8 by siRNAs (n = 7 per group) or antisense morpholino (n = 8 per group) on tumor growth. Survival was analyzed using the Kaplan-Meier method and group differences by the Student’s t test. All statistical tests were two-sided. Results: LC tumors overexpressed E2F8 compared with normal lung tissues. Depletion of E2F8 inhibited cell proliferation and tumor growth. E2F8 knockdown statistically significantly reduced the expression of UHRF1 (~60%-70%, P < .001), and the direct binding of E2F8 on the promoter of UHRF1 was identified. Kaplan-Meier analysis with a public database showed prognostic significance of aberrant E2F8 expression in LC (HR = 1.91 95% CI = 1.21 to 3.01 in chemo-naïve patients, P = .0047). Conclusions: We demonstrated that E2F8 is overexpressed in LC and is required for the growth of LC cells. These findings implicate E2F8 as a novel therapeutic target for LC treatment. PMID:26089541

Gene deregulation and spatial genome reorganization near breakpoints prior to formation of translocations in anaplastic large cell lymphoma.

PubMed

Mathas, Stephan; Kreher, Stephan; Meaburn, Karen J; Jöhrens, Korinna; Lamprecht, Björn; Assaf, Chalid; Sterry, Wolfram; Kadin, Marshall E; Daibata, Masanori; Joos, Stefan; Hummel, Michael; Stein, Harald; Janz, Martin; Anagnostopoulos, Ioannis; Schrock, Evelin; Misteli, Tom; Dörken, Bernd

2009-04-07

Although the identification and characterization of translocations have rapidly increased, little is known about the mechanisms of how translocations occur in vivo. We used anaplastic large cell lymphoma (ALCL) with and without the characteristic t(2;5)(p23;q35) translocation to study the mechanisms of formation of translocations and of ALCL transformation. We report deregulation of several genes located near the ALCL translocation breakpoint, regardless of whether the tumor contains the t(2;5). The affected genes include the oncogenic transcription factor Fra2 (located on 2p23), the HLH protein Id2 (2p25), and the oncogenic tyrosine kinase CSF1-receptor (5q33.1). Their up-regulation promotes cell survival and repression of T cell-specific gene expression programs that are characteristic for ALCL. The deregulated genes are in spatial proximity within the nuclear space of t(2;5)-negative ALCL cells, facilitating their translocation on induction of double-strand breaks. These data suggest that deregulation of breakpoint-proximal genes occurs before the formation of translocations, and that aberrant transcriptional activity of genomic regions is linked to their propensity to undergo chromosomal translocations. Also, our data demonstrate that deregulation of breakpoint-proximal genes has a key role in ALCL.

Gene deregulation and spatial genome reorganization near breakpoints prior to formation of translocations in anaplastic large cell lymphoma

PubMed Central

Mathas, Stephan; Kreher, Stephan; Meaburn, Karen J.; Jöhrens, Korinna; Lamprecht, Björn; Assaf, Chalid; Sterry, Wolfram; Kadin, Marshall E.; Daibata, Masanori; Joos, Stefan; Hummel, Michael; Stein, Harald; Janz, Martin; Anagnostopoulos, Ioannis; Schrock, Evelin; Misteli, Tom; Dörken, Bernd

2009-01-01

Although the identification and characterization of translocations have rapidly increased, little is known about the mechanisms of how translocations occur in vivo. We used anaplastic large cell lymphoma (ALCL) with and without the characteristic t(2;5)(p23;q35) translocation to study the mechanisms of formation of translocations and of ALCL transformation. We report deregulation of several genes located near the ALCL translocation breakpoint, regardless of whether the tumor contains the t(2;5). The affected genes include the oncogenic transcription factor Fra2 (located on 2p23), the HLH protein Id2 (2p25), and the oncogenic tyrosine kinase CSF1-receptor (5q33.1). Their up-regulation promotes cell survival and repression of T cell-specific gene expression programs that are characteristic for ALCL. The deregulated genes are in spatial proximity within the nuclear space of t(2;5)-negative ALCL cells, facilitating their translocation on induction of double-strand breaks. These data suggest that deregulation of breakpoint-proximal genes occurs before the formation of translocations, and that aberrant transcriptional activity of genomic regions is linked to their propensity to undergo chromosomal translocations. Also, our data demonstrate that deregulation of breakpoint-proximal genes has a key role in ALCL. PMID:19321746

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

Telecommunications Policy Research Conference. Regulation, Deregulation & Competition Section. Papers.

ERIC Educational Resources Information Center

Telecommunications Policy Research Conference, Inc., Washington, DC.

Three papers discuss aspects of telecommunications regulation in a deregulated environment. The first paper, "Implementing Telephone Deregulation: The Political Economy of State Regulation in the Post-Divestiture Era" (Paul E. Teske), analyzed the variation in state regulation of local telephone operating companies using regression…

E2F1 transcription is induced by genotoxic stress through ATM/ATR activation.

PubMed

Carcagno, Abel L; Ogara, María F; Sonzogni, Silvina V; Marazita, Mariela C; Sirkin, Pablo F; Ceruti, Julieta M; Cánepa, Eduardo T

2009-05-01

E2F1, a member of the E2F family of transcription factors, plays a critical role in controlling both cell cycle progression and apoptotic cell death in response to DNA damage and oncogene activation. Following genotoxic stresses, E2F1 protein is stabilized by phosphorylation and acetylation driven to its accumulation. The aim of the present work was to examine whether the increase in E2F1 protein levels observed after DNA damage is only a reflection of an increase in E2F1 protein stability or is also the consequence of enhanced transcription of the E2F1 gene. The data presented here demonstrates that UV light and other genotoxics induce the transcription of E2F1 gene in an ATM/ATR dependent manner, which results in increasing E2F1 mRNA and protein levels. After genotoxic stress, transcription of cyclin E, an E2F1 target gene, was significantly induced. This induction was the result of two well-differentiated effects, one of them dependent on de novo protein synthesis and the other on the protein stabilization. Our results strongly support a transcriptional effect of DNA damaging agents on E2F1 expression. The results presented herein uncover a new mechanism involving E2F1 in response to genotoxic stress.

Aneuploidy-dependent massive deregulation of the cellular transcriptome and apparent divergence of the Wnt/beta-catenin signaling pathway in human rectal carcinomas.

PubMed

Grade, Marian; Ghadimi, B Michael; Varma, Sudhir; Simon, Richard; Wangsa, Danny; Barenboim-Stapleton, Linda; Liersch, Torsten; Becker, Heinz; Ried, Thomas; Difilippantonio, Michael J

2006-01-01

To identify genetic alterations underlying rectal carcinogenesis, we used global gene expression profiling of a series of 17 locally advanced rectal adenocarcinomas and 20 normal rectal mucosa biopsies on oligonucleotide arrays. A total of 351 genes were differentially expressed (P < 1.0e-7) between normal rectal mucosa and rectal carcinomas, 77 genes had a >5-fold difference, and 85 genes always had at least a 2-fold change in all of the matched samples. Twelve genes satisfied all three of these criteria. Altered expression of genes such as PTGS2 (COX-2), WNT1, TGFB1, VEGF, and MYC was confirmed, whereas our data for other genes, like PPARD and LEF1, were inconsistent with previous reports. In addition, we found deregulated expression of many genes whose involvement in rectal carcinogenesis has not been reported. By mapping the genomic imbalances in the tumors using comparative genomic hybridization, we could show that DNA copy number gains of recurrently aneuploid chromosome arms 7p, 8q, 13q, 18q, 20p, and 20q correlated significantly with their average chromosome arm expression profile. Taken together, our results show that both the high-level, significant transcriptional deregulation of specific genes and general modification of the average transcriptional activity of genes residing on aneuploid chromosomes coexist in rectal adenocarcinomas.

Chronic fatigue syndrome: exercise performance related to immune dysfunction.

PubMed

Nijs, Jo; Meeus, Mira; McGregor, Neil R; Meeusen, Romain; de Schutter, Guy; van Hoof, Elke; de Meirleir, Kenny

2005-10-01

To date, the exact cause of abnormal exercise response in chronic fatigue syndrome (CFS) remains to be revealed, but evidence addressing intracellular immune deregulation in CFS is growing. Therefore, the aim of this cross-sectional study was to examine the interactions between several intracellular immune variables and exercise performance in CFS patients. After venous blood sampling, subjects (16 CFS patients) performed a maximal exercise stress test on a bicycle ergometer with continuous monitoring of cardiorespiratory variables. The following immune variables were assessed: the ratio of 37 kDa Ribonuclease (RNase) L to the 83 kDa native RNase L (using a radiolabeled ligand/receptor assay), RNase L enzymatic activity (enzymatic assay), protein kinase R activity assay (comparison Western blot), elastase activity (enzymatic-colorimetric assay), the percent of monocytes, and nitric oxide determination (for monocytes and lymphocytes; flow cytometry, live cell assay). Forward stepwise multiple regression analysis revealed 1) that elastase activity was the only factor related to the reduction in oxygen uptake at a respiratory exchange ratio (RER) of 1.0 (regression model: R = 0.53, F (1,14) = 15.5, P < 0.002; elastase activity P < 0.002); 2) that the protein kinase R activity was the principle factor related to the reduction in workload at RER = 1.0; and 3) that elastase activity was the principle factor related to the reduction in percent of target heart rate achieved. These data provide evidence for an association between intracellular immune deregulation and exercise performance in patients with CFS. To establish a causal relationship, further study of these interactions using a prospective longitudinal design is required.

KCa2 channels activation prevents [Ca2+]i deregulation and reduces neuronal death following glutamate toxicity and cerebral ischemia

PubMed Central

Dolga, A M; Terpolilli, N; Kepura, F; Nijholt, I M; Knaus, H-G; D'Orsi, B; Prehn, J H M; Eisel, U L M; Plant, T; Plesnila, N; Culmsee, C

2011-01-01

Exacerbated activation of glutamate receptor-coupled calcium channels and subsequent increase in intracellular calcium ([Ca2+]i) are established hallmarks of neuronal cell death in acute and chronic neurological diseases. Here we show that pathological [Ca2+]i deregulation occurring after glutamate receptor stimulation is effectively modulated by small conductance calcium-activated potassium (KCa2) channels. We found that neuronal excitotoxicity was associated with a rapid downregulation of KCa2.2 channels within 3 h after the onset of glutamate exposure. Activation of KCa2 channels preserved KCa2 expression and significantly reduced pathological increases in [Ca2+]i providing robust neuroprotection in vitro and in vivo. These data suggest a critical role for KCa2 channels in excitotoxic neuronal cell death and propose their activation as potential therapeutic strategy for the treatment of acute and chronic neurodegenerative disorders. PMID:21509037

KCa2 channels activation prevents [Ca2+]i deregulation and reduces neuronal death following glutamate toxicity and cerebral ischemia.

PubMed

Dolga, A M; Terpolilli, N; Kepura, F; Nijholt, I M; Knaus, H-G; D'Orsi, B; Prehn, J H M; Eisel, U L M; Plant, T; Plesnila, N; Culmsee, C

2011-04-21

Exacerbated activation of glutamate receptor-coupled calcium channels and subsequent increase in intracellular calcium ([Ca2+]i) are established hallmarks of neuronal cell death in acute and chronic neurological diseases. Here we show that pathological [Ca2+]i deregulation occurring after glutamate receptor stimulation is effectively modulated by small conductance calcium-activated potassium (KCa2) channels. We found that neuronal excitotoxicity was associated with a rapid downregulation of KCa2.2 channels within 3 h after the onset of glutamate exposure. Activation of KCa2 channels preserved KCa2 expression and significantly reduced pathological increases in [Ca2+]i providing robust neuroprotection in vitro and in vivo. These data suggest a critical role for KCa2 channels in excitotoxic neuronal cell death and propose their activation as potential therapeutic strategy for the treatment of acute and chronic neurodegenerative disorders.

How the early sporulation sigma factor sigmaF delays the switch to late development in Bacillus subtilis.

PubMed

Karmazyn-Campelli, Céline; Rhayat, Lamya; Carballido-López, Rut; Duperrier, Sandra; Frandsen, Niels; Stragier, Patrick

2008-03-01

Sporulation in Bacillus subtilis is a primitive differentiation process involving two cell types, the forespore and the mother cell. Each cell implements two successive transcription programmes controlled by specific sigma factors. We report that activity of sigma(G), the late forespore sigma factor, is kept in check by Gin, the product of csfB, a gene controlled by sigma(F), the early forespore sigma factor. Gin abolishes sigma(G) transcriptional activity when sigma(G) is artificially synthesized during growth, but has no effect on sigma(F). Gin interacts strongly with sigma(G) but not with sigma(F) in a yeast two-hybrid experiment. The absence of Gin allows sigma(G) to be active during sporulation independently of the mother-cell development to which it is normally coupled. Premature sigma(G) activity leads to the formation of slow-germinating spores, and complete deregulation of sigma(G) synthesis is lethal when combined with gin inactivation. Gin allows sigma(F) to delay the switch to the late forespore transcription programme by preventing sigma(G) to take over before the cell has reached a critical stage of development. A similar strategy, following a completely unrelated route, is used by the mother cell.

E2F8 as a Novel Therapeutic Target for Lung Cancer.

PubMed

Park, Sin-Aye; Platt, James; Lee, Jong Woo; López-Giráldez, Francesc; Herbst, Roy S; Koo, Ja Seok

2015-09-01

The E2F members have been divided into transcription activators (E2F1-E2F3) and repressors (E2F4-E2F8). E2F8 with E2F7 has been known to play an important physiologic role in embryonic development and cell cycle regulation by repressing E2F1. However, the function of E2F8 in cancer cells is unknown. E2F8 expression was assessed by immunoblotting or immunofluorescence staining in human lung cancer (LC) cells and tissues from LC patients (n = 45). Cell proliferation, colony formation, and invasion analysis were performed to evaluate the role of E2F8 in LC. Microarray analysis was used to determine the target genes of E2F8. The regulation of E2F8 on the expression of ubiquitin-like PHD and RING domain-containing 1 (UHRF1), one of E2F8 target genes, was determined using chromatin immunoprecipitation and promoter activity assays. Human LC xenograft models were used to determine the effects of inhibiting E2F8 by siRNAs (n = 7 per group) or antisense morpholino (n = 8 per group) on tumor growth. Survival was analyzed using the Kaplan-Meier method and group differences by the Student's t test. All statistical tests were two-sided. LC tumors overexpressed E2F8 compared with normal lung tissues. Depletion of E2F8 inhibited cell proliferation and tumor growth. E2F8 knockdown statistically significantly reduced the expression of UHRF1 (~60%-70%, P < .001), and the direct binding of E2F8 on the promoter of UHRF1 was identified. Kaplan-Meier analysis with a public database showed prognostic significance of aberrant E2F8 expression in LC (HR = 1.91 95% CI = 1.21 to 3.01 in chemo-naïve patients, P = .0047). We demonstrated that E2F8 is overexpressed in LC and is required for the growth of LC cells. These findings implicate E2F8 as a novel therapeutic target for LC treatment. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

YAP Inhibition Restores Hepatocyte Differentiation in Advanced HCC, Leading to Tumor Regression.

PubMed

Fitamant, Julien; Kottakis, Filippos; Benhamouche, Samira; Tian, Helen S; Chuvin, Nicolas; Parachoniak, Christine A; Nagle, Julia M; Perera, Rushika M; Lapouge, Marjorie; Deshpande, Vikram; Zhu, Andrew X; Lai, Albert; Min, Bosun; Hoshida, Yujin; Avruch, Joseph; Sia, Daniela; Campreciós, Genís; McClatchey, Andrea I; Llovet, Josep M; Morrissey, David; Raj, Lakshmi; Bardeesy, Nabeel

2015-03-10

Defective Hippo/YAP signaling in the liver results in tissue overgrowth and development of hepatocellular carcinoma (HCC). Here, we uncover mechanisms of YAP-mediated hepatocyte reprogramming and HCC pathogenesis. YAP functions as a rheostat in maintaining metabolic specialization, differentiation, and quiescence within the hepatocyte compartment. Increased or decreased YAP activity reprograms subsets of hepatocytes to different fates associated with deregulation of the HNF4A, CTNNB1, and E2F transcriptional programs that control hepatocyte quiescence and differentiation. Importantly, treatment with small interfering RNA-lipid nanoparticles (siRNA-LNPs) targeting YAP restores hepatocyte differentiation and causes pronounced tumor regression in a genetically engineered mouse HCC model. Furthermore, YAP targets are enriched in an aggressive human HCC subtype characterized by a proliferative signature and absence of CTNNB1 mutations. Thus, our work reveals Hippo signaling as a key regulator of the positional identity of hepatocytes, supports targeting of YAP using siRNA-LNPs as a paradigm of differentiation-based therapy, and identifies an HCC subtype that is potentially responsive to this approach. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Analysis of E2F factors during epidermal differentiation.

PubMed

Chang, Wing Y; Dagnino, Lina

2005-01-01

The multigene E2F family of transcription factors is central in the control of cell cycle progression. The expression and activity of E2F proteins is tightly regulated transcriptionally and posttranslationally as a function of the proliferation and differentiation status of the cell. In this chapter, we review protocols designed to determine E2F mRNA abundance in tissues by in situ hybridization techniques. The ability to culture primary epidermal keratinocytes and maintain them as either undifferentiated or terminally differentiated cells allows the biochemical and molecular characterization of changes in E2F expression and activity. Thus, we also discuss in detail methods to analyze E2F protein abundance by immunoblot and their ability to bind DNA in cultured cells using electrophoretic mobility shift assays.

Targeting Signaling to YAP for the Therapy of NF2

DTIC Science & Technology

2015-10-01

clear mechanism of Merlin’s tumor suppressor function. Our studies have shown that inactivation of Merlin/NF2 de-regulates the E3 ubiquitin ligase...Keywords NF2, E3 ubiquitin ligase, high throughput small molecule screening, targeted therapy. 6 Accomplishment Major goals and objectives

Aberrant activity of NKL homeobox gene NKX3-2 in a T-ALL subset

PubMed Central

Meyer, Corinna; Kaufmann, Maren; Zaborski, Margarete; MacLeod, Roderick A. F.; Drexler, Hans G.

2018-01-01

T-cell acute lymphoblastic leukemia (T-ALL) is a hematopoietic malignancy originating from T-cell progenitors in which differentiation is blocked at early stages. Physiological expression of specific NKL homeobox genes obeys a hematopoietic NKL-code implicated in the process of lymphopoiesis while in differentiated T-cells these genes are silenced. We propose that this developmental expression pattern underlies the observation that NKL homeobox genes are the most ubiquitous group of transcription factors deregulated in T-ALL, including TLX1, TLX3, NKX2-5 and NKX3-1. Here, we describe a novel member of the NKL homeobox gene subclass, NKX3-2 (BAPX1), which is aberrantly activated in 18% of pediatric T-ALL patients analyzed while being normally expressed in developing spleen. Identification of NKX3-2 expression in T-ALL cell line CCRF-CEM qualified these cells to model its deregulation and function in a leukemic context. Genomic and chromosomal analyses demonstrated normal configuration of the NKX3-2 locus at chromosome 4p15, thus excluding cytogenetic dysregulation. Comparative expression profiling analysis of NKX3-2 patient data revealed deregulated activity of BMP- and MAPK-signalling. These candidate pathways were experimentally confirmed to mediate aberrant NKX3-2 expression. We also show that homeobox gene SIX6, plus MIR17HG and GATA3 are downstream targets of NKX3-2 and plausibly contribute to the pathogenesis of this malignancy by suppressing T-cell differentiation. Finally, NKL homeobox gene NKX2-5 was activated by NKX3-2 in CCRF-CEM and by FOXG1 in PEER, representing mutually inhibitory activators of this translocated oncogene. Together, our findings reveal a novel oncogenic NKL homeobox gene subclass member which is aberrantly expressed in a large subset of T-ALL patients and participates in a deregulated gene network likely to arise in developing spleen. PMID:29746601

Aberrant activity of NKL homeobox gene NKX3-2 in a T-ALL subset.

PubMed

Nagel, Stefan; Meyer, Corinna; Kaufmann, Maren; Zaborski, Margarete; MacLeod, Roderick A F; Drexler, Hans G

2018-01-01

T-cell acute lymphoblastic leukemia (T-ALL) is a hematopoietic malignancy originating from T-cell progenitors in which differentiation is blocked at early stages. Physiological expression of specific NKL homeobox genes obeys a hematopoietic NKL-code implicated in the process of lymphopoiesis while in differentiated T-cells these genes are silenced. We propose that this developmental expression pattern underlies the observation that NKL homeobox genes are the most ubiquitous group of transcription factors deregulated in T-ALL, including TLX1, TLX3, NKX2-5 and NKX3-1. Here, we describe a novel member of the NKL homeobox gene subclass, NKX3-2 (BAPX1), which is aberrantly activated in 18% of pediatric T-ALL patients analyzed while being normally expressed in developing spleen. Identification of NKX3-2 expression in T-ALL cell line CCRF-CEM qualified these cells to model its deregulation and function in a leukemic context. Genomic and chromosomal analyses demonstrated normal configuration of the NKX3-2 locus at chromosome 4p15, thus excluding cytogenetic dysregulation. Comparative expression profiling analysis of NKX3-2 patient data revealed deregulated activity of BMP- and MAPK-signalling. These candidate pathways were experimentally confirmed to mediate aberrant NKX3-2 expression. We also show that homeobox gene SIX6, plus MIR17HG and GATA3 are downstream targets of NKX3-2 and plausibly contribute to the pathogenesis of this malignancy by suppressing T-cell differentiation. Finally, NKL homeobox gene NKX2-5 was activated by NKX3-2 in CCRF-CEM and by FOXG1 in PEER, representing mutually inhibitory activators of this translocated oncogene. Together, our findings reveal a novel oncogenic NKL homeobox gene subclass member which is aberrantly expressed in a large subset of T-ALL patients and participates in a deregulated gene network likely to arise in developing spleen.

Potential antidiabetic activity of extracellular polysaccharides in submerged fermentation culture of Coriolus versicolor LH1.

PubMed

Yang, John Powen; Hsu, Taihao; Lin, Fangyi; Hsu, Wenkuang; Chen, Yucheng

2012-09-01

The separation and purification of extracellular polysaccharides from Coriolus versicolor LH1 were investigated along with their α-glucosidase inhibition properties. Three polysaccharide fractions (ePS-F2-1, ePS-F3-1, and ePS-F4-1) were separated from the culture medium of LH1 using a DEAE anion-exchange column and a Sephadex™ G-50 gel filtration column. Their chemical compositions was determined. On the basis of an α-glucosidase inhibition assay, the enzyme inhibition activities of ePS-F2-1, ePS-F3-1, and ePS-F4-1 were investigated. Among these, ePS-F4-1 had the highest enzyme inhibition effects on α-glucosidase. According to the results of the chemical component analysis, ePS-F3-1 and ePS-F4-1 are the polysaccharides which are combined with triterpenoides, and ePS-F2-1 is complexed with proteins and triterpenoides. Copyright © 2012 Elsevier Ltd. All rights reserved.

The expression of miR-21 and miR-143 is deregulated by the HPV16 E7 oncoprotein and 17β-estradiol.

PubMed

Gómez-Gómez, Yazmín; Organista-Nava, Jorge; Ocadiz-Delgado, Rodolfo; García-Villa, Enrique; Leyva-Vazquez, Marco Antonio; Illades-Aguiar, Berenice; Lambert, Paul F; García-Carrancá, Alejandro; Gariglio, Patricio

2016-08-01

MicroRNAs (miRNAs) are a class of non-coding RNAs that negatively regulate their target mRNAs at a posttranscriptional level, thereby affecting crucial processes in cancer development. However, little is known about the molecular events that control expression of miRNAs in cervical cancer (CC). HPV16 E7 oncoprotein in conjunction with estrogen are sufficient to produce high grade cervical dysplasia and invasive cervical malignancies in a mouse model. In the present study, we determined the potential role that the E7 oncoprotein and 17β-estradiol (E2) play in the deregulation of miR-21 and miR-143 expression levels by these two risk factors. We found that, while the expression of miR-21 was upregulated and the expression of miR-143 was downregulated by the HPV16 E7 oncoprotein in vivo, and in vitro and that E2 treatment is also implicated in the deregulation of these important miRNAs in vivo. Sustained upregulation of miR-21 resulted in suppression of PTEN expression, and repression of miR-143 increased the mRNA and protein levels from Bcl-2. These results suggested that HPV type 16 E7 oncoprotein and E2 play an important role in regulating miR-21 and miR-143 expression. We have observed similar results in CC patients containing HPV16 sequences, suggesting that these miRNAs could serve as diagnostic biomarkers in CC. The present study highlights the roles of miRNAs in cervical tissue and implicates these important molecules in cervical carcinogenesis.

Characterization of two genes encoding the Mycobacterium tuberculosis ribonucleotide reductase small subunit.

PubMed Central

Yang, F; Curran, S C; Li, L S; Avarbock, D; Graf, J D; Chua, M M; Lu, G; Salem, J; Rubin, H

1997-01-01

Two nrdF genes, nrdF1 and nrdF2, encoding the small subunit (R2) of ribonucleotide reductase (RR) from Mycobacterium tuberculosis have 71% identity at the amino acid level and are both highly homologous with Salmonella typhimurium R2F. The calculated molecular masses of R2-1 and R2-2 are 36,588 (322 amino acids [aa]) and 36,957 (324 aa) Da, respectively. Western blot analysis of crude M. tuberculosis extracts indicates that both R2s are expressed in vivo. Recombinant R2-2 is enzymatically active when assayed with pure recombinant M. tuberculosis R1 subunit. Both ATP and dATP are activators for CDP reduction up to 2 and 1 mM, respectively. The gene encoding M. tuberculosis R2-1, nrdF1, is not linked to nrdF2, nor is either gene linked to the gene encoding the large subunit, M. tuberculosis nrdE. The gene encoding MTP64 was found downstream from nrdF1, and the gene encoding alcohol dehydrogenase was found downstream from nrdF2. A nrdA(Ts) strain of E. coli (E101) could be complemented by simultaneous transformation with M. tuberculosis nrdE and nrdF2. An M. tuberculosis nrdF2 variant in which the codon for the catalytically necessary tyrosine was replaced by the phenylalanine codon did not complement E101 when cotransformed with M. tuberculosis nrdE. Similarly, M. tuberculosis nrdF1 and nrdE did not complement E101. Activity of recombinant M. tuberculosis RR was inhibited by incubating the enzyme with a peptide corresponding to the 7 C-terminal amino acid residues of the R2-2 subunit. M. tuberculosis is a species in which a nrdEF system appears to encode the biologically active species of RR and also the only bacterial species identified so far in which class I RR subunits are not arranged on an operon. PMID:9335290

NmF2 and hmF2 measurements at 95° E and 127° E around the EIA northern crest during 2010-2014

NASA Astrophysics Data System (ADS)

Kalita, Bitap Raj; Bhuyan, Pradip Kumar; Yoshikawa, Akimasa

2015-11-01

The characteristics of the F2 layer parameters NmF2 and hmF2 over Dibrugarh (27.5° N, 95° E, 17° N geomagnetic, 43° dip) measured by a Canadian Advanced Digital Ionosonde (CADI) for the period of August 2010 to July 2014 are reported for the first time from this low mid-latitude station lying within the daytime peak of the longitudinal wave number 4 structure of equatorial anomaly (EIA) around the northern edge of anomaly crest. Equinoctial asymmetry is clearly observed at all solar activity levels whereas the midday winter anomaly is observed only during high solar activity years and disappears during the temporary dip in solar activity in 2013 but forenoon winter anomaly can be observed even at moderate solar activity. The NmF2/hmF2 variations over Dibrugarh are compared with that of Okinawa (26.5° N, 127° E, 17° N geomagnetic), and the eastward propagation speed of the wave number 4 longitudinal structure from 95° E to 127° E is estimated. The speed is found to be close to the theoretical speed of the wave number 4 (WN4) structure. The correlation of daily NmF2 over Dibrugarh and Okinawa with solar activity exhibits diurnal and seasonal variations. The highest correlation in daytime is observed during the forenoon hours in equinox. The correlation of daily NmF2 (linear or non-linear) with solar activity exhibits diurnal variation. A tendency for amplification with solar activity is observed in the forenoon and late evening period of March equinox and the postsunset period of December solstice. NmF2 saturation effect is observed only in the midday period of equinox. Non-linear variation of neutral composition at higher altitudes and variation of recombination rates with solar activity via temperature dependence may be related to the non-linear trend. The noon time maximum NmF2 over Dibrugarh exhibits better correlation with equatorial electrojet (EEJ) than with solar activity and, therefore, new low-latitude NmF2 index is proposed taking both solar activity and EEJ strength into account.

Phosphorylation of Mps1 by BRAFV600E prevents Mps1 degradation and contributes to chromosome instability in melanoma.

PubMed

Liu, J; Cheng, X; Zhang, Y; Li, S; Cui, H; Zhang, L; Shi, R; Zhao, Z; He, C; Wang, C; Zhao, H; Zhang, C; Fisk, H A; Guadagno, T M; Cui, Y

2013-02-07

Activating BRAF mutations that deregulate the mitogen-activated protein kinase (MAPK) pathway commonly occur in cancer. BRAF(V600E) induces centrosome amplification and spindle abnormalities that result in aneuploidy. We find modification of Mps1 is critical for contributing to centrosome amplification and chromosome instability induced by BRAF(V600E). Phosphorylation of Mps1 at residue S281 induced by BRAF(V600E) stabilizes Mps1 protein by preventing its ubiquitination by APC/C and subsequent degradation, allowing the non-degraded protein to accumulate at centrosomes. Cells in which endogenous Mps1 was replaced with a phospho-mimetic Mps1 mutant are viable but amplify centrosomes and missegregate chromosomes frequently. Importantly, analysis of tumor micro arrays revealed that phospho-MAPK and S281-phosphorylated Mps1 were highly correlated in human melanoma tissues, implying that MAPK contributes to defects in the degradation of Mps1 in situ. We propose that continuously activated BRAF(V600E) signaling may be a possible mechanism for the deregulation of Mps1 stability and kinase activity in human tumors, and that persistent phosphorylation of Mps1 through BRAF(V600E) signaling is a key event in disrupting the control of centrosome duplication and chromosome stability that may contribute to tumorigenesis. Our findings raise the possibility that targeting the oncogenic BRAF and S281-phosphorylated Mps1, especially when used in combination could potentially provide great therapeutic opportunities for cancer treatment.

The association of GSK3 beta with E2F1 facilitates nerve growth factor-induced neural cell differentiation.

PubMed

Zhou, Fangfang; Zhang, Long; Wang, Aijun; Song, Bo; Gong, Kai; Zhang, Lihai; Hu, Min; Zhang, Xiufang; Zhao, Nanming; Gong, Yandao

2008-05-23

It is widely acknowledged that E2F1 and GSK3beta are both involved in the process of cell differentiation. However, the relationship between E2F1 and GSK3beta in cell differentiation has yet to be discovered. Here, we provide evidence that in the differentiation of PC12 cells induced by nerve growth factor (NGF), GSK3beta was increased at both the mRNA and protein levels, whereas E2F1 at these two levels was decreased. Both wild-type GSK3beta and its kinase-defective mutant GSK3beta KM can inhibit E2F1 by promoting its ubiquitination through physical interaction. In addition, the colocalization of GSK3beta and E2F1 and their subcellular distribution, regulated by NGF, were observed in the process of PC12 differentiation. At the tissue level, GSK3beta colocalized and interacted with E2F1 in mouse hippocampus. Furthermore, GSK3beta facilitated neurite outgrowth by rescuing the promoter activities of Cdk inhibitors p21 and p15 from the inhibition caused by E2F1. To summarize, our findings suggest that GSK3beta can promote the ubiquitination of E2F1 via physical interaction and thus inhibit its transcription activity in a kinase activity independent manner, which plays an important role in the NGF-induced PC12 differentiation.

Embryonic Lethality Due to Arrested Cardiac Development in Psip1/Hdgfrp2 Double-Deficient Mice.

PubMed

Wang, Hao; Shun, Ming-Chieh; Dickson, Amy K; Engelman, Alan N

2015-01-01

Hepatoma-derived growth factor (HDGF) related protein 2 (HRP2) and lens epithelium-derived growth factor (LEDGF)/p75 are closely related members of the HRP2 protein family. LEDGF/p75 has been implicated in numerous human pathologies including cancer, autoimmunity, and infectious disease. Knockout of the Psip1 gene, which encodes for LEDGF/p75 and the shorter LEDGF/p52 isoform, was previously shown to cause perinatal lethality in mice. The function of HRP2 was by contrast largely unknown. To learn about the role of HRP2 in development, we knocked out the Hdgfrp2 gene, which encodes for HRP2, in both normal and Psip1 knockout mice. Hdgfrp2 knockout mice developed normally and were fertile. By contrast, the double deficient mice died at approximate embryonic day (E) 13.5. Histological examination revealed ventricular septal defect (VSD) associated with E14.5 double knockout embryos. To investigate the underlying molecular mechanism(s), RNA recovered from ventricular tissue was subjected to RNA-sequencing on the Illumina platform. Bioinformatic analysis revealed several genes and biological pathways that were significantly deregulated by the Psip1 knockout and/or Psip1/Hdgfrp2 double knockout. Among the dozen genes known to encode for LEDGF/p75 binding factors, only the expression of Nova1, which encodes an RNA splicing factor, was significantly deregulated by the knockouts. However the expression of other RNA splicing factors, including the LEDGF/p52-interacting protein ASF/SF2, was not significantly altered, indicating that deregulation of global RNA splicing was not a driving factor in the pathology of the VSD. Tumor growth factor (Tgf) β-signaling, which plays a key role in cardiac morphogenesis during development, was the only pathway significantly deregulated by the double knockout as compared to control and Psip1 knockout samples. We accordingly speculate that deregulated Tgf-β signaling was a contributing factor to the VSD and prenatal lethality of Psip1/Hdgfrp2 double-deficient mice.

A lentiviral vector with expression controlled by E2F-1: A potential tool for the study and treatment of proliferative diseases

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

Strauss, Bryan E.; Patricio, Juliana Rotelli; Program in Biotechnology, University of Sao Paulo

2006-10-06

We have constructed a lentiviral vector with expression limited to cells presenting active E2F-1 protein, a potential advantage for gene therapy of proliferative diseases. For the FE2FLW vector, the promoter region of the human E2F-1 gene was utilized to drive expression of luciferase cDNA, included as a reporter of viral expression. Primary, immortalized, and transformed cells were transduced with the FE2FLW vector and cell cycle alterations were induced with serum starvation/replacement, contact inhibition or drug treatment, revealing cell cycle-dependent changes in reporter activity. Forced E2F-1 expression, but not E2F-2 or E2F-3, increased reporter activity, indicating a major role for thismore » factor in controlling expression from the FE2FLW virus. We show the utility of this vector as a reporter of E2F-1 and proliferation-dependent cellular alterations upon cytotoxic/cytostatic treatment, such as the introduction of tumor suppressor genes. We propose that the FE2FLW vector may be a starting point for the development of gene therapy strategies for proliferative diseases, such as cancer or restinosis.« less

Pathway deregulation and expression QTLs in response to Actinobacillus pleuropneumoniae infection in swine.

PubMed

Reiner, Gerald; Dreher, Felix; Drungowski, Mario; Hoeltig, Doris; Bertsch, Natalie; Selke, Martin; Willems, Hermann; Gerlach, Gerald Friedrich; Probst, Inga; Tuemmler, Burkhardt; Waldmann, Karl-Heinz; Herwig, Ralf

2014-12-01

Actinobacillus (A.) pleuropneumoniae is among the most important pathogens in pig. The agent causes severe economic losses due to decreased performance, the occurrence of acute or chronic pleuropneumonia, and an increase in death incidence. Since therapeutics cannot be used in a sustainable manner, and vaccination is not always available, new prophylactic measures are urgently needed. Recent research has provided evidence for a genetic predisposition in susceptibility to A. pleuropneumoniae in a Hampshire × German Landrace F2 family with 170 animals. The aim of the present study is to characterize the expression response in this family in order to unravel resistance and susceptibility mechanisms and to prioritize candidate genes for future fine mapping approaches. F2 pigs differed distinctly in clinical, pathological, and microbiological parameters after challenge with A. pleuropneumoniae. We monitored genome-wide gene expression from the 50 most and 50 least susceptible F2 pigs and identified 171 genes differentially expressed between these extreme phenotypes. We combined expression QTL analyses with network analyses and functional characterization using gene set enrichment analysis and identified a functional hotspot on SSC13, including 55 eQTL. The integration of the different results provides a resource for candidate prioritization for fine mapping strategies, such as TF, TFRC, RUNX1, TCN1, HP, CD14, among others.

MYC Deregulation in Primary Human Cancers

PubMed Central

Kalkat, Manpreet; De Melo, Jason; Hickman, Katherine Ashley; Lourenco, Corey; Redel, Cornelia; Resetca, Diana; Tamachi, Aaliya; Tu, William B.; Penn, Linda Z.

2017-01-01

MYC regulates a complex biological program by transcriptionally activating and repressing its numerous target genes. As such, MYC is a master regulator of many processes, including cell cycle entry, ribosome biogenesis, and metabolism. In cancer, the activity of the MYC transcriptional network is frequently deregulated, contributing to the initiation and maintenance of disease. Deregulation often leads to constitutive overexpression of MYC, which can be achieved through gross genetic abnormalities, including copy number alterations, chromosomal translocations, increased enhancer activity, or through aberrant signal transduction leading to increased MYC transcription or increased MYC mRNA and protein stability. Herein, we summarize the frequency and modes of MYC deregulation and describe both well-established and more recent findings in a variety of cancer types. Notably, these studies have highlighted that with an increased appreciation for the basic mechanisms deregulating MYC in cancer, new therapeutic vulnerabilities can be discovered and potentially exploited for the inhibition of this potent oncogene in cancer. PMID:28587062

Modulation of E2F activity in primary mouse B cells following stimulation via surface IgM and CD40 receptors.

PubMed

Lam, E W; Glassford, J; van der Sman, J; Banerji, L; Pizzey, A R; Shaun, N; Thomas, B; Klaus, G G

1999-10-01

Since signals via CD40 and the B cell receptor are known to synergize to induce B cell activation, we have analyzed the pocket protein/E2F complexes in mouse B lymphocytes following stimulation by anti-IgM, anti-CD40, alone or together. We find that E2F4 and DP1 form the predominant E2F heterodimers in the G0 and G1 phases of the cell cycle, complexed with hypophosphorylated p130. During late G1 and S phase this complex is replaced by at least three different E2F complexes, one of which is an E2F complex containing p107 or pRB as well as two "free" E2F complexes consisting of E2F4/DP1 and E2F1-3/DP1. These effects were mirrored by the levels and phosphorylation status of the three pocket proteins. We also observed an increase in electrophoretic mobility of DP1 and E2F4 as B cells progressed from G0 into early G1, resulting from their dephosphorylation. This is known to correlate with a decrease in DNA binding capacity of these proteins and could also be important for derepression of genes negatively regulated through E2F sites in their promoters. These results therefore indicate that the pRB/E2F pathway integrates proliferative signals emanating from the sIgM and CD40 receptors.

Genetic Ablation of CCAAT/Enhancer Binding Protein α in Epidermis Reveals Its Role in Suppression of Epithelial Tumorigenesis

PubMed Central

Loomis, Kari D.; Zhu, Songyun; Yoon, Kyungsil; Johnson, Peter F.; Smart, Robert C.

2013-01-01

CCAAT/enhancer binding protein y (C/EBPα) is a basic leucine zipper transcription factor that inhibits cell cycle progression and regulates differentiation in various cell types. C/EBPα is inactivated by mutation in acute myeloid leukemia (AML) and is considered a human tumor suppressor in AML. Although C/EBPα mutations have not been observed in malignancies other than AML, greatly diminished expression of C/EBPα occurs in numerous human epithelial cancers including lung, liver, endometrial, skin, and breast, suggesting a possible tumor suppressor function. However, direct evidence for C/EBPα as an epithelial tumor suppressor is lacking due to the absence of C/EBPα mutations in epithelial tumors and the lethal effect of C/EBPα deletion in mouse model systems. To examine the function of C/EBPα in epithelial tumor development, an epidermal-specific C/EBPα knockout mouse was generated. The epidermal-specific C/EBPα knockout mice survived and displayed no detectable abnormalities in epidermal keratinocyte proliferation, differentiation, or apoptosis, showing that C/EBPα is dispensable for normal epidermal homeostasis. In spite of this, the epidermal-specific C/EBPα knockout mice were highly susceptible to skin tumor development involving oncogenic Ras. These mice displayed decreased tumor latency and striking increases in tumor incidence, multiplicity, growth rate, and the rate of malignant progression. Mice hemizygous for C/EBPα displayed an intermediate-enhanced tumor phenotype. Our results suggest that decreased expression of C/EBPα contributes to deregulation of tumor cell proliferation. C/EBPα had been proposed to block cell cycle progression through inhibition of E2F activity. We observed that C/EBPα blocked Ras-induced and epidermal growth factor-induced E2F activity in keratinocytes and also blocked Ras-induced cell transformation and cell cycle progression. Our study shows that C/EBPα is dispensable for epidermal homeostasis and provides genetic evidence that C/EBPα is a suppressor of epithelial tumorigenesis. PMID:17638888

Activation of the Rb/E2F1 pathway by the nonproliferative p38 MAPK during Fas (APO1/CD95)-mediated neuronal apoptosis.

PubMed

Hou, Sheng T; Xie, Xiaoqi; Baggley, Anne; Park, David S; Chen, Gao; Walker, Teena

2002-12-13

Aberrant activation of the Rb/E2F1 pathway in cycling cells, in response to mitogenic or nonmitogenic stress signals, leads to apoptosis through hyperphosphorylation of Rb. To test whether in postmitotic neurons the Rb/E2F1 pathway can be activated by the nonmitogenic stress signaling, we examined the role of the p38 stress-activated protein kinase (SAPK) in regulating Rb phosphorylation in response to Fas (CD95/APO1)-mediated apoptosis of cultured cerebellar granule neurons (CGNs). Anti-Fas antibody induced a dramatic and early activation of p38. Activated p38 was correlated with the induction of hyperphosphorylation of both endogenous and exogenous Rb. The p38-selective inhibitor, SB203580, attenuated such an increase in pRb phosphorylation and significantly protected CGNs from Fas-induced apoptosis. The cyclin-dependent kinase-mediated Rb phosphorylation played a lesser role in this neuronal death paradigm, since cyclin-dependent kinase inhibitors, such as olomoucine, roscovitine, and flavopiridol, did not significantly prevent anti-Fas antibody-evoked neuronal apoptosis. Hyperphosphorylation of Rb by p38 SAPK resulted in the release of Rb-bound E2F1. Increased E2F1 modulated neuronal apoptosis, since E2F1-/- CGNs were significantly less susceptible to Fas-mediated apoptosis in comparison with the wild-type CGNs. Taken together, these studies demonstrate that neuronal Rb/E2F1 is modulated by the nonproliferative p38 SAPK in Fas-mediated neuronal apoptosis.

Curcumin Derivative Epigenetically Reactivates Nrf2 Antioxidative Stress Signaling in Mouse Prostate Cancer TRAMP C1 Cells.

PubMed

Li, Wenji; Su, Zheng-Yuan; Guo, Yue; Zhang, Chengyue; Wu, Renyi; Gao, Linbo; Zheng, Xi; Du, Zhi-Yun; Zhang, Kun; Kong, Ah-Ng

2018-02-19

The carcinogenesis of prostate cancer (PCa) in TRAMP model is highly correlated with hypermethylation in the promoter region of Nrf2 and the accompanying reduced transcription of Nrf2 and its regulated detoxifying genes. We aimed to investigate the effects of (3E,5E)-3,5-bis-(3,4,5-trimethoxybenzylidene)-tetrahydro-thiopyran-4-one (F10) and (3E,5E)-3,5-bis-(3,4,5-trimethoxy-benzylidene)-tetrahydropyran-4-one (E10), two synthetic curcumin derivatives, on restoring Nrf2 activity in TRAMP C1 cells. HepG2-C8 cells transfected with an antioxidant-response element (ARE)-luciferase vector were treated with F10, E10, curcumin, and sulforaphane (SFN) to compare their effects on Nrf2-ARE pathways. We performed real-time quantitative PCR and Western blotting to investigate the effects of F10 and E10 on Nrf2, correlated phase II detoxification genes. We also measured expression and activity of DNMTand HDAC enzymes. Enrichment of H3K27me3 on the promoter region of Nrf2 was explored with a chromatin immunoprecipitation (ChIP) assay. Methylation of the CpG region in Nrf2 promoter was doubly examined by bisulfite genomic sequencing (BGS) and methylation DNA immunoprecipitation (MeDIP). Compared with curcumin and SFN, F10 is more potent in activating Nrf2-ARE pathways. Both F10 and E10 enhanced level of Nrf2 and the correlated phase II detoxifying genes. BGS and MeDIP assays indicated that F10 but not E10 hypomethylated the Nrf2 promoter. F10 also downregulated the protein level of DNMT1, DNMT3a, DNMT3b, HDAC1, HDAC4, and HDAC7 and the activity of DNMTs and HDACs. F10 but not E10 effectively reduced the accumulation of H3k27me3 on the promoter of Nrf2. F10 and E10 can activate the Nrf2-ARE pathway and increase the level of Nrf2 and correlated phase II detoxification genes. The reactivation effect on Nrf2 by F10 in TRAMP C1 may come from demethylation, decrease of HDACs, and inhibition of H3k27me3 accumulation.

Gene expression profiling reveals a massive, aneuploidy-dependent transcriptional deregulation and distinct differences between lymph node-negative and lymph node-positive colon carcinomas.

PubMed

Grade, Marian; Hörmann, Patrick; Becker, Sandra; Hummon, Amanda B; Wangsa, Danny; Varma, Sudhir; Simon, Richard; Liersch, Torsten; Becker, Heinz; Difilippantonio, Michael J; Ghadimi, B Michael; Ried, Thomas

2007-01-01

To characterize patterns of global transcriptional deregulation in primary colon carcinomas, we did gene expression profiling of 73 tumors [Unio Internationale Contra Cancrum stage II (n = 33) and stage III (n = 40)] using oligonucleotide microarrays. For 30 of the tumors, expression profiles were compared with those from matched normal mucosa samples. We identified a set of 1,950 genes with highly significant deregulation between tumors and mucosa samples (P < 1e-7). A significant proportion of these genes mapped to chromosome 20 (P = 0.01). Seventeen genes had a >5-fold average expression difference between normal colon mucosa and carcinomas, including up-regulation of MYC and of HMGA1, a putative oncogene. Furthermore, we identified 68 genes that were significantly differentially expressed between lymph node-negative and lymph node-positive tumors (P < 0.001), the functional annotation of which revealed a preponderance of genes that play a role in cellular immune response and surveillance. The microarray-derived gene expression levels of 20 deregulated genes were validated using quantitative real-time reverse transcription-PCR in >40 tumor and normal mucosa samples with good concordance between the techniques. Finally, we established a relationship between specific genomic imbalances, which were mapped for 32 of the analyzed colon tumors by comparative genomic hybridization, and alterations of global transcriptional activity. Previously, we had conducted a similar analysis of primary rectal carcinomas. The systematic comparison of colon and rectal carcinomas revealed a significant overlap of genomic imbalances and transcriptional deregulation, including activation of the Wnt/beta-catenin signaling cascade, suggesting similar pathogenic pathways.

Transcriptional deregulation of oncogenic myocyte enhancer factor 2C in T-cell acute lymphoblastic leukemia.

PubMed

Nagel, Stefan; Venturini, Letizia; Meyer, Corinna; Kaufmann, Maren; Scherr, Michaela; Drexler, Hans G; Macleod, Roderick A F

2011-02-01

Myocyte enhancer factor 2C (MEF2C) encodes a transcription factor which is ectopically expressed in T-cell acute lymphoblastic leukemia (T-ALL) cell lines, deregulated directly by ectopically expressed homeodomain protein NKX2-5 or by loss of promoter regions via del(5)(q14). Here, we analyzed the MEF2C 5'-region, thus identifying potential regulatory binding sites for GFI1B, basic helix-loop-helix proteins, STAT5, and HOXA9/HOXA10. Chromatin immunoprecipitation and overexpression analyses demonstrated direct activation by GFI1B and LYL1 and inhibition by STAT5. HOXA9/HOXA10 activated expression of NMYC which in turn mediated MEF2C repression, indicating an indirect mode of regulation via NMYC interactor (NMI) and STAT5. Lacking comma: Chromosomal deletion of the STAT5 binding site in LOUCY cells reduced protein levels of STAT5 in some MEF2C-positve T-ALL cell lines, and the presence of inhibitory IL7-JAK-STAT5 signaling highlighted the repressive impact of this factor in MEF2C regulation. Taken together, our results indicate that the expression of MEF2C in T-ALL cells is principally deregulated via activating leukemic transcription factors GFI1B or NKX2-5 and by escaping inhibitory developmental STAT5 signaling.

Does deregulation in community pharmacy impact accessibility of medicines, quality of pharmacy services and costs? Evidence from nine European countries.

PubMed

Vogler, Sabine; Habimana, Katharina; Arts, Danielle

2014-09-01

To analyse the impact of deregulation in community pharmacy on accessibility of medicines, quality of pharmacy services and costs. We analysed and compared community pharmacy systems in five rather deregulated countries (England, Ireland, the Netherlands, Norway, Sweden) and four rather regulated countries (Austria, Denmark, Finland, Spain). Data were collected by literature review, a questionnaire survey and interviews. Following a deregulation, several new pharmacies and dispensaries of Over-the-Counter (OTC) medicines tended to be established, predominantly in urban areas. Unless prevented by regulation, specific stakeholders, e.g. wholesalers, were seen to gain market dominance which limited envisaged competition. There were indications for an increased workload for pharmacists in some deregulated countries. Economic pressure to increase the pharmacy turnover through the sale of OTC medicines and non-pharmaceuticals was observed in deregulated and regulated countries. Prices of OTC medicines were not found to decrease after a deregulation in pharmacy. Access to pharmacies usually increases after a deregulation but this is likely to favour urban populations with already good accessibility. Policy-makers are recommended to take action to ensure equitable accessibility and sustainable competition in a more deregulated environment. No association between pharmaceutical expenditure and the extent of regulation/deregulation appears to exist. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

The evaluation of anoxia responsive E2F DNA binding activity in the red eared slider turtle, Trachemys scripta elegans.

PubMed

Biggar, Kyle K; Storey, Kenneth B

2018-01-01

In many cases, the DNA-binding activity of a transcription factor does not change, while its transcriptional activity is greatly influenced by the make-up of bound proteins. In this study, we assessed the protein composition and DNA-binding ability of the E2F transcription factor complex to provide insight into cell cycle control in an anoxia tolerant turtle through the use of a modified ELISA protocol. This modification also permits the use of custom DNA probes that are tailored to a specific DNA binding region, introducing the ability to design capture probes for non-model organisms. Through the use of EMSA and ELISA DNA binding assays, we have successfully determined the in vitro DNA binding activity and complex dynamics of the Rb/E2F cell cycle regulatory mechanisms in an anoxic turtle, Trachemys scripta elegans . Repressive cell cycle proteins (E2F4, Rb, HDAC4 and Suv39H1) were found to significantly increase at E2F DNA-binding sites upon anoxic exposure in anoxic turtle liver. The lack of p130 involvement in the E2F DNA-bound complex indicates that anoxic turtle liver may maintain G 1 arrest for the duration of stress survival.

The evaluation of anoxia responsive E2F DNA binding activity in the red eared slider turtle, Trachemys scripta elegans

PubMed Central

Biggar, Kyle K.

2018-01-01

In many cases, the DNA-binding activity of a transcription factor does not change, while its transcriptional activity is greatly influenced by the make-up of bound proteins. In this study, we assessed the protein composition and DNA-binding ability of the E2F transcription factor complex to provide insight into cell cycle control in an anoxia tolerant turtle through the use of a modified ELISA protocol. This modification also permits the use of custom DNA probes that are tailored to a specific DNA binding region, introducing the ability to design capture probes for non-model organisms. Through the use of EMSA and ELISA DNA binding assays, we have successfully determined the in vitro DNA binding activity and complex dynamics of the Rb/E2F cell cycle regulatory mechanisms in an anoxic turtle, Trachemys scripta elegans. Repressive cell cycle proteins (E2F4, Rb, HDAC4 and Suv39H1) were found to significantly increase at E2F DNA-binding sites upon anoxic exposure in anoxic turtle liver. The lack of p130 involvement in the E2F DNA-bound complex indicates that anoxic turtle liver may maintain G1 arrest for the duration of stress survival. PMID:29770276

The over expression of long non-coding RNA ANRIL promotes epithelial-mesenchymal transition by activating the ATM-E2F1 signaling pathway in pancreatic cancer: An in vivo and in vitro study.

PubMed

Chen, Shi; Zhang, Jia-Qiang; Chen, Jiang-Zhi; Chen, Hui-Xing; Qiu, Fu-Nan; Yan, Mao-Lin; Chen, Yan-Ling; Peng, Cheng-Hong; Tian, Yi-Feng; Wang, Yao-Dong

2017-09-01

This study aims to investigate the roles of lncRNA ANRIL in epithelial-mesenchymal transition (EMT) by regulating the ATM-E2F1 signaling pathway in pancreatic cancer (PC). PC rat models were established and ANRIL overexpression and interference plasmids were transfected. The expression of ANRIL, EMT markers (E-cadherin, N-cadherin and Vimentin) and ATM-E2F1 signaling pathway-related proteins (ATM, E2F1, INK4A, INK4B and ARF) were detected. Small molecule drugs were applied to activate and inhibit the ATM-E2F1 signaling pathway. Transwell assay and the scratch test were adopted to detect cell invasion and migration abilities. ANRIL expression in the PC cells was higher than in normal pancreatic duct epithelial cells. In the PC rat models and PC cells, ANRIL interference promoted the expressions of INK4B, INK4A, ARF and E-cadherin, while reduced N-cadherin and Vimentin expression. Over-expressed ANRIL decreased the expression of INK4B, INK4A, ARF and E-cadherin, but raised N-cadherin and Vimentin expressions. By inhibiting the ATM-E2F1 signaling pathway in PC cells, E-cadherin expression increased but N-cadherin and Vimentin expressions decreased. After ANRIL was silenced or the ATM-E2F1 signaling pathway inhibited, PC cell migration and invasion abilities were decreased. In conclusion, over-expression of lncRNA ANRIL can promote EMT of PC cells by activating the ATM-E2F1 signaling pathway. Copyright © 2017 Elsevier B.V. All rights reserved.

Post-transcriptional gene expression control by NANOS is up-regulated and functionally important in pRb-deficient cells

PubMed Central

Miles, Wayne O; Korenjak, Michael; Griffiths, Lyra M; Dyer, Michael A; Provero, Paolo; Dyson, Nicholas J

2014-01-01

Inactivation of the retinoblastoma tumor suppressor (pRb) is a common oncogenic event that alters the expression of genes important for cell cycle progression, senescence, and apoptosis. However, in many contexts, the properties of pRb-deficient cells are similar to wild-type cells suggesting there may be processes that counterbalance the transcriptional changes associated with pRb inactivation. Therefore, we have looked for sets of evolutionary conserved, functionally related genes that are direct targets of pRb/E2F proteins. We show that the expression of NANOS, a key facilitator of the Pumilio (PUM) post-transcriptional repressor complex, is directly repressed by pRb/E2F in flies and humans. In both species, NANOS expression increases following inactivation of pRb/RBF1 and becomes important for tissue homeostasis. By analyzing datasets from normal retinal tissue and pRb-null retinoblastomas, we find a strong enrichment for putative PUM substrates among genes de-regulated in tumors. These include pro-apoptotic genes that are transcriptionally down-regulated upon pRb loss, and we characterize two such candidates, MAP2K3 and MAP3K1, as direct PUM substrates. Our data suggest that NANOS increases in importance in pRb-deficient cells and helps to maintain homeostasis by repressing the translation of transcripts containing PUM Regulatory Elements (PRE). PMID:25100735

Post-transcriptional gene expression control by NANOS is up-regulated and functionally important in pRb-deficient cells.

PubMed

Miles, Wayne O; Korenjak, Michael; Griffiths, Lyra M; Dyer, Michael A; Provero, Paolo; Dyson, Nicholas J

2014-10-01

Inactivation of the retinoblastoma tumor suppressor (pRb) is a common oncogenic event that alters the expression of genes important for cell cycle progression, senescence, and apoptosis. However, in many contexts, the properties of pRb-deficient cells are similar to wild-type cells suggesting there may be processes that counterbalance the transcriptional changes associated with pRb inactivation. Therefore, we have looked for sets of evolutionary conserved, functionally related genes that are direct targets of pRb/E2F proteins. We show that the expression of NANOS, a key facilitator of the Pumilio (PUM) post-transcriptional repressor complex, is directly repressed by pRb/E2F in flies and humans. In both species, NANOS expression increases following inactivation of pRb/RBF1 and becomes important for tissue homeostasis. By analyzing datasets from normal retinal tissue and pRb-null retinoblastomas, we find a strong enrichment for putative PUM substrates among genes de-regulated in tumors. These include pro-apoptotic genes that are transcriptionally down-regulated upon pRb loss, and we characterize two such candidates, MAP2K3 and MAP3K1, as direct PUM substrates. Our data suggest that NANOS increases in importance in pRb-deficient cells and helps to maintain homeostasis by repressing the translation of transcripts containing PUM Regulatory Elements (PRE). © 2014 The Authors.

Mutations in the HECT domain of NEDD4L lead to AKT-mTOR pathway deregulation and cause periventricular nodular heterotopia.

PubMed

Broix, Loïc; Jagline, Hélène; Ivanova, Ekaterina; Schmucker, Stéphane; Drouot, Nathalie; Clayton-Smith, Jill; Pagnamenta, Alistair T; Metcalfe, Kay A; Isidor, Bertrand; Louvier, Ulrike Walther; Poduri, Annapurna; Taylor, Jenny C; Tilly, Peggy; Poirier, Karine; Saillour, Yoann; Lebrun, Nicolas; Stemmelen, Tristan; Rudolf, Gabrielle; Muraca, Giuseppe; Saintpierre, Benjamin; Elmorjani, Adrienne; Moïse, Martin; Weirauch, Nathalie Bednarek; Guerrini, Renzo; Boland, Anne; Olaso, Robert; Masson, Cecile; Tripathy, Ratna; Keays, David; Beldjord, Cherif; Nguyen, Laurent; Godin, Juliette; Kini, Usha; Nischké, Patrick; Deleuze, Jean-François; Bahi-Buisson, Nadia; Sumara, Izabela; Hinckelmann, Maria-Victoria; Chelly, Jamel

2016-11-01

Neurodevelopmental disorders with periventricular nodular heterotopia (PNH) are etiologically heterogeneous, and their genetic causes remain in many cases unknown. Here we show that missense mutations in NEDD4L mapping to the HECT domain of the encoded E3 ubiquitin ligase lead to PNH associated with toe syndactyly, cleft palate and neurodevelopmental delay. Cellular and expression data showed sensitivity of PNH-associated mutants to proteasome degradation. Moreover, an in utero electroporation approach showed that PNH-related mutants and excess wild-type NEDD4L affect neurogenesis, neuronal positioning and terminal translocation. Further investigations, including rapamycin-based experiments, found differential deregulation of pathways involved. Excess wild-type NEDD4L leads to disruption of Dab1 and mTORC1 pathways, while PNH-related mutations are associated with deregulation of mTORC1 and AKT activities. Altogether, these data provide insights into the critical role of NEDD4L in the regulation of mTOR pathways and their contributions in cortical development.

Capsaicin Displays Anti-Proliferative Activity against Human Small Cell Lung Cancer in Cell Culture and Nude Mice Models via the E2F Pathway

PubMed Central

Hardman, W. Elaine; Luo, Haitao; Chen, Yi C.; Carpenter, A. Betts; Lau, Jamie K.; Dasgupta, Piyali

2010-01-01

Background Small cell lung cancer (SCLC) is characterized by rapid progression and low survival rates. Therefore, novel therapeutic agents are urgently needed for this disease. Capsaicin, the active ingredient of chilli peppers, displays anti-proliferative activity in prostate and epidermoid cancer in vitro. However, the anti-proliferative activity of capsaicin has not been studied in human SCLCs. The present manuscript fills this void of knowledge and explores the anti-proliferative effect of capsaicin in SCLC in vitro and in vivo. Methodology/Principal Findings BrdU assays and PCNA ELISAs showed that capsaicin displays robust anti-proliferative activity in four human SCLC cell lines. Furthermore, capsaicin potently suppressed the growth of H69 human SCLC tumors in vivo as ascertained by CAM assays and nude mice models. The second part of our study attempted to provide insight into molecular mechanisms underlying the anti-proliferative activity of capsaicin. We found that the anti-proliferative activity of capsaicin is correlated with a decrease in the expression of E2F-responsive proliferative genes like cyclin E, thymidylate synthase, cdc25A and cdc6, both at mRNA and protein levels. The transcription factor E2F4 mediated the anti-proliferative activity of capsaicin. Ablation of E2F4 levels by siRNA methodology suppressed capsaicin-induced G1 arrest. ChIP assays demonstrated that capsaicin caused the recruitment of E2F4 and p130 on E2F-responsive proliferative promoters, thereby inhibiting cell proliferation. Conclusions/Significance Our findings suggest that the anti-proliferative effects of capsaicin could be useful in the therapy of human SCLCs. PMID:20421925

E2F transcription factors and digestive system malignancies: how much do we know?

PubMed

Xanthoulis, Athanasios; Tiniakos, Dina G

2013-06-07

E2F family of transcription factors regulates various cellular functions related to cell cycle and apoptosis. Its individual members have traditionally been classified into activators and repressors, based on in vitro studies. However their contribution in human cancer is more complicated and difficult to predict. We review current knowledge on the expression of E2Fs in digestive system malignancies and its clinical implications for patient prognosis and treatment. E2F1, the most extensively studied member and the only one with prognostic value, exhibits a tumor-suppressing activity in esophageal, gastric and colorectal adenocarcinoma, and in hepatocellular carcinoma (HCC), whereas in pancreatic ductal adenocarcinoma and esophageal squamous cell carcinoma may function as a tumor-promoter. In the latter malignancies, E2F1 immunohistochemical expression has been correlated with higher tumor grade and worse patient survival, whereas in esophageal, gastric and colorectal adenocarcinomas is a marker of increased patient survival. E2F2 has only been studied in colorectal cancer, where its role is not considered significant. E2F4's role in colorectal, gastric and hepatic carcinogenesis is tumor-promoting. E2F8 is strongly upregulated in human HCC, thus possibly contributing to hepatocarcinogenesis. Adenoviral transfer of E2F as gene therapy to sensitize pancreatic cancer cells for chemotherapeutic agents has been used in experimental studies. Other therapeutic strategies are yet to be developed, but it appears that targeted approaches using E2F-agonists or antagonists should take into account the tissue-dependent function of each E2F member. Further understanding of E2Fs' contribution in cellular functions in vivo would help clarify their role in carcinogenesis.

Epigenetic Alterations Associated with CCCTC-Binding Factor Deregulation in Prostate Cancer

DTIC Science & Technology

2012-07-01

HPV16  E6  and/or  E7  prostate cell lines.  We have had to reestablish stable cell lines containing inducible multiple CTCF  shRNA in pTRIPZ vector in PPC...1, LNCaPs, 293T and non‐tumorigenic HPV16  E6   5 and/or  E7  prostate cell lines. We have had to rederive these due to leakage from the  promoter...empty pTRIPZ vector and control scrambled shRNA.  f. To test the tumorigenic ability of CTCF shRNA infected non‐tumorigenic  E6 / E7  cells using colony

Epigenetic Alterations Associated With CCCTC-Binding Factor Deregulation in Prostate Cancer

DTIC Science & Technology

2013-09-01

cancer cells. (Months 1‐12)  a. Establish cell cultures of human prostate cancer (PC‐3 and PPC‐1) cell  lines, HPECs, non‐tumorigenic HPV16  E6  and/or  E7 ...and non‐tumorigenic HPV16  E6   5 and/or  E7  prostate cell lines. We have had to rederive these due to leakage from the  promoter leading to clonal...and control scrambled shRNA.  f. To test the tumorigenic ability of CTCF shRNA infected non‐tumorigenic  E6 / E7  cells using colony forming assays and

Enhancing eNOS activity with simultaneous inhibition of IKKβ restores vascular function in Ins2(Akita+/-) type-1 diabetic mice.

PubMed

Krishnan, Manickam; Janardhanan, Preethi; Roman, Linda; Reddick, Robert L; Natarajan, Mohan; van Haperen, Rien; Habib, Samy L; de Crom, Rini; Mohan, Sumathy

2015-10-01

The balance of nitric oxide (NO) versus superoxide generation has a major role in the initiation and progression of endothelial dysfunction. Under conditions of high glucose, endothelial nitric oxide synthase (eNOS) functions as a chief source of superoxide rather than NO. In order to improve NO bioavailability within the vessel wall in type-1 diabetes, we investigated treatment strategies that improve eNOS phosphorylation and NO-dependent vasorelaxation. We evaluated methods to increase the eNOS activity by (1) feeding Ins2(Akita) spontaneously diabetic (type-1) mice with l-arginine in the presence of sepiapterin, a precursor of tetrahydrobiopterin; (2) preventing eNOS/NO deregulation by the inclusion of inhibitor kappa B kinase beta (IKKβ) inhibitor, salsalate, in the diet regimen in combination with l-arginine and sepiapterin; and (3) independently increasing eNOS expression to improve eNOS activity and associated NO production through generating Ins2(Akita) diabetic mice that overexpress human eNOS predominantly in vascular endothelial cells. Our results clearly demonstrated that diet supplementation with l-arginine, sepiapterin along with salsalate improved phosphorylation of eNOS and enhanced vasorelaxation of thoracic/abdominal aorta in type-1 diabetic mice. More interestingly, despite the overexpression of eNOS, the in-house generated transgenic eNOS-GFP (TgeNOS-GFP)-Ins2(Akita) cross mice showed an unanticipated effect of reduced eNOS phosphorylation and enhanced superoxide production. Our results demonstrate that enhancement of endogenous eNOS activity by nutritional modulation is more beneficial than increasing the endogenous expression of eNOS by gene therapy modalities.

EBP1 is a novel E2F target gene regulated by transforming growth factor-β.

PubMed

Judah, David; Chang, Wing Y; Dagnino, Lina

2010-11-10

Regulation of gene expression requires transcription factor binding to specific DNA elements, and a large body of work has focused on the identification of such sequences. However, it is becoming increasingly clear that eukaryotic transcription factors can exhibit widespread, nonfunctional binding to genomic DNA sites. Conversely, some of these proteins, such as E2F, can also modulate gene expression by binding to non-consensus elements. E2F comprises a family of transcription factors that play key roles in a wide variety of cellular functions, including survival, differentiation, activation during tissue regeneration, metabolism, and proliferation. E2F factors bind to the Erb3-binding protein 1 (EBP1) promoter in live cells. We now show that E2F binding to the EBP1 promoter occurs through two tandem DNA elements that do not conform to typical consensus E2F motifs. Exogenously expressed E2F1 activates EBP1 reporters lacking one, but not both sites, suggesting a degree of redundancy under certain conditions. E2F1 increases the levels of endogenous EBP1 mRNA in breast carcinoma and other transformed cell lines. In contrast, in non-transformed primary epidermal keratinocytes, E2F, together with the retinoblastoma family of proteins, appears to be involved in decreasing EBP1 mRNA abundance in response to growth inhibition by transforming growth factor-β1. Thus, E2F is likely a central coordinator of multiple responses that culminate in regulation of EBP1 gene expression, and which may vary depending on cell type and context.

11β-Hydroxysteroid dehydrogenase type-2 and type-1 (11β-HSD2 and 11β-HSD1) and 5β-reductase activities in the pathogenia of essential hypertension.

PubMed

Campino, Carmen; Carvajal, Cristian A; Cornejo, Javiera; San Martín, Betty; Olivieri, Oliviero; Guidi, Giancesare; Faccini, Giovanni; Pasini, Francesco; Sateler, Javiera; Baudrand, Rene; Mosso, Lorena; Owen, Gareth I; Kalergis, Alexis M; Padilla, Oslando; Fardella, Carlos E

2010-02-01

Cortisol availability is modulated by several enzymes: 11β-HSD2, which transforms cortisol (F) to cortisone (E) and 11β-HSD1 which predominantly converts inactive E to active F. Additionally, the A-ring reductases (5α- and 5β-reductase) inactivate cortisol (together with 3α-HSD) to tetrahydrometabolites: 5αTHF, 5βTHF, and THE. The aim was to assess 11β-HSD2, 11β-HSD1, and 5β-reductase activity in hypertensive patients. Free urinary F, E, THF, and THE were measured by HPLC-MS/MS in 102 essential hypertensive patients and 18 normotensive controls. 11β-HSD2 enzyme activity was estimated by the F/E ratio, the activity of 11β-HSD1 in compare to 11β-HSD2 was inferred by the (5αTHF + 5βTHF)/THE ratio and 5β-reductase activity assessed using the E/THE ratio. Activity was considered altered when respective ratios exceeded the maximum value observed in the normotensive controls. A 15.7% of patients presented high F/E ratio suggesting a deficit of 11β-HSD2 activity. Of the remaining 86 hypertensive patients, two possessed high (5αTHF + 5βTHF)/THE ratios and 12.8% had high E/THE ratios. We observed a high percentage of alterations in cortisol metabolism at pre-receptor level in hypertensive patients, previously misclassified as essential. 11β-HSD2 and 5β-reductase decreased activity and imbalance of 11β-HSDs should be considered in the future management of hypertensive patients.

Elevated autophagy gene expression in adipose tissue of obese humans: A potential non-cell-cycle-dependent function of E2F1

PubMed Central

Haim, Yulia; Blüher, Matthias; Slutsky, Noa; Goldstein, Nir; Klöting, Nora; Harman-Boehm, Ilana; Kirshtein, Boris; Ginsberg, Doron; Gericke, Martin; Guiu Jurado, Esther; Kovsan, Julia; Tarnovscki, Tanya; Kachko, Leonid; Bashan, Nava; Gepner, Yiftach; Shai, Iris; Rudich, Assaf

2015-01-01

Autophagy genes' expression is upregulated in visceral fat in human obesity, associating with obesity-related cardio-metabolic risk. E2F1 (E2F transcription factor 1) was shown in cancer cells to transcriptionally regulate autophagy. We hypothesize that E2F1 regulates adipocyte autophagy in obesity, associating with endocrine/metabolic dysfunction, thereby, representing non-cell-cycle function of this transcription factor. E2F1 protein (N=69) and mRNA (N=437) were elevated in visceral fat of obese humans, correlating with increased expression of ATG5 (autophagy-related 5), MAP1LC3B/LC3B (microtubule-associated protein 1 light chain 3 β), but not with proliferation/cell-cycle markers. Elevated E2F1 mainly characterized the adipocyte fraction, whereas MKI67 (marker of proliferation Ki-67) was elevated in the stromal-vascular fraction of adipose tissue. In human visceral fat explants, chromatin-immunoprecipitation revealed body mass index (BMI)-correlated increase in E2F1 binding to the promoter of MAP1LC3B, but not to the classical cell cycle E2F1 target, CCND1 (cyclin D1). Clinically, omental fat E2F1 expression correlated with insulin resistance, circulating free-fatty-acids (FFA), and with decreased circulating ADIPOQ/adiponectin, associations attenuated by adjustment for autophagy genes. Overexpression of E2F1 in HEK293 cells enhanced promoter activity of several autophagy genes and autophagic flux, and sensitized to further activation of autophagy by TNF. Conversely, mouse embryonic fibroblast (MEF)-derived adipocytes from e2f1 knockout mice (e2f1−/−) exhibited lower autophagy gene expression and flux, were more insulin sensitive, and secreted more ADIPOQ. Furthermore, e2f1−/− MEF-derived adipocytes, and autophagy-deficient (by Atg7 siRNA) adipocytes were resistant to cytokines-induced decrease in ADIPOQ secretion. Jointly, upregulated E2F1 sensitizes adipose tissue autophagy to inflammatory stimuli, linking visceral obesity to adipose and systemic metabolic-endocrine dysfunction. PMID:26391754

[Design of new anti-tumor agents interrupting deregulated signaling pathways induced by tyrosine kinase proteins. Inhibition of protein-protein interaction involving Grb2].

PubMed

Vidal, Michel; Liu, Wang Qing; Gril, Brunile; Assayag, Franck; Poupon, Marie-France; Garbay, Christiane

2004-01-01

Cellular signaling pathways induced by growth-factor receptors are frequently deregulated in cancer. Anti-tumor agents that inhibit their enzymatic tyrosine kinase activity have been designed and are now used in human chemotherapy. We propose here an alternative way to interrupt over-expressed signaling by inhibiting protein-protein interactions that involve either the over-expressed proteins or proteins located downstream. The adaptor protein Grb2 over-expressed in connection with HER2/ErbB2/neu in Ras signaling pathway was chosen as a target. Peptides with very high affinity for Grb2 were rationally designed from structural data. Their capacity to interrupt the signaling pathway, their anti-proliferative activity as well as their potential anti-tumor properties are described.

A single oncogenic enhancer rearrangement causes concomitant EVI1 and GATA2 deregulation in leukemia.

PubMed

Gröschel, Stefan; Sanders, Mathijs A; Hoogenboezem, Remco; de Wit, Elzo; Bouwman, Britta A M; Erpelinck, Claudia; van der Velden, Vincent H J; Havermans, Marije; Avellino, Roberto; van Lom, Kirsten; Rombouts, Elwin J; van Duin, Mark; Döhner, Konstanze; Beverloo, H Berna; Bradner, James E; Döhner, Hartmut; Löwenberg, Bob; Valk, Peter J M; Bindels, Eric M J; de Laat, Wouter; Delwel, Ruud

2014-04-10

Chromosomal rearrangements without gene fusions have been implicated in leukemogenesis by causing deregulation of proto-oncogenes via relocation of cryptic regulatory DNA elements. AML with inv(3)/t(3;3) is associated with aberrant expression of the stem-cell regulator EVI1. Applying functional genomics and genome-engineering, we demonstrate that both 3q rearrangements reposition a distal GATA2 enhancer to ectopically activate EVI1 and simultaneously confer GATA2 functional haploinsufficiency, previously identified as the cause of sporadic familial AML/MDS and MonoMac/Emberger syndromes. Genomic excision of the ectopic enhancer restored EVI1 silencing and led to growth inhibition and differentiation of AML cells, which could be replicated by pharmacologic BET inhibition. Our data show that structural rearrangements involving the chromosomal repositioning of a single enhancer can cause deregulation of two unrelated distal genes, with cancer as the outcome. Copyright © 2014 Elsevier Inc. All rights reserved.

A C2HC zinc finger is essential for the RING-E2 interaction of the ubiquitin ligase RNF125

PubMed Central

Bijlmakers, Marie-José; Teixeira, João M. C.; Boer, Roeland; Mayzel, Maxim; Puig-Sàrries, Pilar; Karlsson, Göran; Coll, Miquel; Pons, Miquel; Crosas, Bernat

2016-01-01

The activity of RING ubiquitin ligases (E3s) depends on an interaction between the RING domain and ubiquitin conjugating enzymes (E2), but posttranslational events or additional structural elements, yet largely undefined, are frequently required to enhance or regulate activity. Here, we show for the ubiquitin ligase RNF125 that, in addition to the RING domain, a C2HC Zn finger (ZnF) is crucial for activity, and a short linker sequence (Li2120-128) enhances activity. The contribution of these regions was first shown with truncated proteins, and the essential role of the ZnF was confirmed with mutations at the Zn chelating Cys residues. Using NMR, we established that the C2HC ZnF/Li2120-128 region is crucial for binding of the RING domain to the E2 UbcH5a. The partial X-ray structure of RNF125 revealed the presence of extensive intramolecular interactions between the RING and C2HC ZnF. A mutation at one of the contact residues in the C2HC ZnF, a highly conserved M112, resulted in the loss of ubiquitin ligase activity. Thus, we identified the structural basis for an essential role of the C2HC ZnF and conclude that this domain stabilizes the RING domain, and is therefore required for binding of RNF125 to an E2. PMID:27411375

Naphthol AS-E Phosphate Inhibits the Activity of the Transcription Factor Myb by Blocking the Interaction with the KIX Domain of the Coactivator p300.

PubMed

Uttarkar, Sagar; Dukare, Sandeep; Bopp, Bertan; Goblirsch, Michael; Jose, Joachim; Klempnauer, Karl-Heinz

2015-06-01

The transcription factor c-Myb is highly expressed in hematopoietic progenitor cells and controls the transcription of genes important for lineage determination, cell proliferation, and differentiation. Deregulation of c-Myb has been implicated in the development of leukemia and certain other types of human cancer. c-Myb activity is highly dependent on the interaction of the c-Myb with the KIX domain of the coactivator p300, making the disruption of this interaction a reasonable strategy for the development of Myb inhibitors. Here, we have used bacterial Autodisplay to develop an in vitro binding assay that mimics the interaction of Myb and the KIX domain of p300. We have used this binding assay to investigate the potential of Naphthol AS-E phosphate, a compound known to bind to the KIX domain, to disrupt the interaction between Myb and p300. Our data show that Naphthol AS-E phosphate interferes with the Myb-KIX interaction in vitro and inhibits Myb activity in vivo. By using several human leukemia cell lines, we demonstrate that Naphthol AS-E phosphate suppresses the expression of Myb target genes and induces myeloid differentiation and apoptosis. Our work identifies Naphthol AS-E phosphate as the first low molecular weight compound that inhibits Myb activity by disrupting its interaction with p300, and suggests that inhibition of the Myb-KIX interaction might be a useful strategy for the treatment of leukemia and other tumors caused by deregulated c-Myb. ©2015 American Association for Cancer Research.

E-cadherin-defective gastric cancer cells depend on Laminin to survive and invade.

PubMed

Caldeira, Joana; Figueiredo, Joana; Brás-Pereira, Catarina; Carneiro, Patrícia; Moreira, Ana M; Pinto, Marta T; Relvas, João B; Carneiro, Fátima; Barbosa, Mário; Casares, Fernando; Janody, Florence; Seruca, Raquel

2015-10-15

Epithelial-cadherin (Ecad) deregulation affects cell-cell adhesion and results in increased invasiveness of distinct human carcinomas. In gastric cancer, loss of Ecad expression is a common event and is associated with disease aggressiveness and poor prognosis. However, the molecular mechanisms underlying the invasive process associated to Ecad dysfunction are far from understood. We hypothesized that deregulation of cell-matrix interactions could play an important role during this process. Thus, we focussed on LM-332, which is a major matrix component, and in Ecad/LM-332 crosstalk in the process of Ecad-dependent invasion. To verify whether matrix deregulation was triggered by Ecad loss, we used the Drosophila model. To dissect the key molecules involved and unveil their functional significance, we used gastric cancer cell lines. The relevance of this relationship was then confirmed in human primary tumours. In vivo, Ecad knockdown induced apoptosis; nonetheless, at the invasive front, cells ectopically expressed Laminin A and βPS integrin. In vitro, we demonstrated that, in two different gastric cancer cell models, Ecad-defective cells overexpressed Laminin γ2 (LM-γ2), β1 and β4 integrin, when compared with Ecad-competent ones. We showed that LM-γ2 silencing impaired invasion and enhanced cell death, most likely via pSrc and pAkt reduction, and JNK activation. In human gastric carcinomas, we found a concomitant decrease in Ecad and increase in LM-γ2. This is the first evidence that ectopic Laminin expression depends on Ecad loss and allows Ecad-dysfunctional cells to survive and invade. This opens new avenues for using LM-γ2 signalling regulators as molecular targets to impair gastric cancer progression. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

E-cadherin-defective gastric cancer cells depend on Laminin to survive and invade

PubMed Central

Caldeira, Joana; Figueiredo, Joana; Brás-Pereira, Catarina; Carneiro, Patrícia; Moreira, Ana M.; Pinto, Marta T.; Relvas, João B.; Carneiro, Fátima; Barbosa, Mário; Casares, Fernando; Janody, Florence; Seruca, Raquel

2015-01-01

Epithelial-cadherin (Ecad) deregulation affects cell–cell adhesion and results in increased invasiveness of distinct human carcinomas. In gastric cancer, loss of Ecad expression is a common event and is associated with disease aggressiveness and poor prognosis. However, the molecular mechanisms underlying the invasive process associated to Ecad dysfunction are far from understood. We hypothesized that deregulation of cell–matrix interactions could play an important role during this process. Thus, we focussed on LM-332, which is a major matrix component, and in Ecad/LM-332 crosstalk in the process of Ecad-dependent invasion. To verify whether matrix deregulation was triggered by Ecad loss, we used the Drosophila model. To dissect the key molecules involved and unveil their functional significance, we used gastric cancer cell lines. The relevance of this relationship was then confirmed in human primary tumours. In vivo, Ecad knockdown induced apoptosis; nonetheless, at the invasive front, cells ectopically expressed Laminin A and βPS integrin. In vitro, we demonstrated that, in two different gastric cancer cell models, Ecad-defective cells overexpressed Laminin γ2 (LM-γ2), β1 and β4 integrin, when compared with Ecad-competent ones. We showed that LM-γ2 silencing impaired invasion and enhanced cell death, most likely via pSrc and pAkt reduction, and JNK activation. In human gastric carcinomas, we found a concomitant decrease in Ecad and increase in LM-γ2. This is the first evidence that ectopic Laminin expression depends on Ecad loss and allows Ecad-dysfunctional cells to survive and invade. This opens new avenues for using LM-γ2 signalling regulators as molecular targets to impair gastric cancer progression. PMID:26246502

Emerin modulates spatial organization of chromosome territories in cells on softer matrices

PubMed Central

Pradhan, Roopali; Ranade, Devika

2018-01-01

Abstract Cells perceive and relay external mechanical forces into the nucleus through the nuclear envelope. Here we examined the effect of lowering substrate stiffness as a paradigm to address the impact of altered mechanical forces on nuclear structure-function relationships. RNA sequencing of cells on softer matrices revealed significant transcriptional imbalances, predominantly in chromatin associated processes and transcriptional deregulation of human Chromosome 1. Furthermore, 3-Dimensional fluorescence in situ hybridization (3D-FISH) analyses showed a significant mislocalization of Chromosome 1 and 19 Territories (CT) into the nuclear interior, consistent with their transcriptional deregulation. However, CT18 with relatively lower transcriptional dysregulation, also mislocalized into the nuclear interior. Furthermore, nuclear Lamins that regulate chromosome positioning, were mislocalized into the nuclear interior in response to lowered matrix stiffness. Notably, Lamin B2 overexpression retained CT18 near the nuclear periphery in cells on softer matrices. While, cells on softer matrices also activated emerin phosphorylation at a novel Tyr99 residue, the inhibition of which in a phospho-deficient mutant (emerinY99F), selectively retained chromosome 18 and 19 but not chromosome 1 territories at their conserved nuclear locations. Taken together, emerin functions as a key mechanosensor, that modulates the spatial organization of chromosome territories in the interphase nucleus. PMID:29684168

A novel mechanism of E2F1 regulation via nucleocytoplasmic shuttling: determinants of nuclear import and export.

PubMed

Ivanova, Iordanka A; Vespa, Alisa; Dagnino, Lina

2007-09-01

E2F1 is a transcription factor central for cell survival, proliferation, and repair following genomic insult. Depending on the cell type and conditions, E2F1 can induce apoptosis in transformed cells, behaving as a tumour suppressor, or impart growth advantages favouring tumour formation. The pleiotropic functions of E2F1 are a likely consequence of its ability to transcriptionally control a wide variety of target genes, and require tight regulation of its activity at multiple levels. Although sequestration of proteins to particular cellular compartments is a well-established regulatory mechanism, virtually nothing is known about its contribution to modulation of E2F1 target gene expression. We have examined the subcellular trafficking of E2F1 and, contrary to the widely held notion that this factor is constitutively nuclear, we now demonstrate that it is subjected to continuous nucleocytoplasmic shuttling. We have also defined two nuclear localization domains and a nuclear export region, which mediates CRM1-dependent transit out of the nucleus. The predominant subcellular location of E2F1 is likely determined by the balance between the activity of nuclear import and export domains, and can be modulated by differentiation stimuli in epidermal cells. Thus, we have identified a hitherto unrecognized mechanism to control E2F1 function through modulation of its subcellular localization.

Division of labour between Myc and G1 cyclins in cell cycle commitment and pace control.

PubMed

Dong, Peng; Maddali, Manoj V; Srimani, Jaydeep K; Thélot, François; Nevins, Joseph R; Mathey-Prevot, Bernard; You, Lingchong

2014-09-01

A body of evidence has shown that the control of E2F transcription factor activity is critical for determining cell cycle entry and cell proliferation. However, an understanding of the precise determinants of this control, including the role of other cell-cycle regulatory activities, has not been clearly defined. Here, recognizing that the contributions of individual regulatory components could be masked by heterogeneity in populations of cells, we model the potential roles of individual components together with the use of an integrated system to follow E2F dynamics at the single-cell level and in real time. These analyses reveal that crossing a threshold amplitude of E2F accumulation determines cell cycle commitment. Importantly, we find that Myc is critical in modulating the amplitude, whereas cyclin D/E activities have little effect on amplitude but do contribute to the modulation of duration of E2F activation, thereby affecting the pace of cell cycle progression.

Novel functions for the transcription factor E2F4 in development and disease

PubMed Central

Sage, Julien

2016-01-01

ABSTRACT The E2F family of transcription factors is a key determinant of cell proliferation in response to extra- and intra-cellular signals. Within this family, E2F4 is a transcriptional repressor whose activity is critical to engage and maintain cell cycle arrest in G0/G1 in conjunction with members of the retinoblastoma (RB) family. However, recent observations challenge this paradigm and indicate that E2F4 has a multitude of functions in cells besides this cell cycle regulatory role, including in embryonic and adult stem cells, during regenerative processes, and in cancer. Some of these new functions are independent of the RB family and involve direct activation of target genes. Here we review the canonical functions of E2F4 and discuss recent evidence expanding the role of this transcription factor, with a focus on cell fate decisions in tissue homeostasis and regeneration. PMID:27753528

E2F1 transcription factor and its impact on growth factor and cytokine signaling.

PubMed

Ertosun, Mustafa Gokhan; Hapil, Fatma Zehra; Osman Nidai, Ozes

2016-10-01

E2F1 is a transcription factor involved in cell cycle regulation and apoptosis. The transactivation capacity of E2F1 is regulated by pRb. In its hypophosphorylated form, pRb binds and inactivates DNA binding and transactivating functions of E2F1. The growth factor stimulation of cells leads to activation of CDKs (cyclin dependent kinases), which in turn phosphorylate Rb and hyperphosphorylated Rb is released from E2F1 or E2F1/DP complex, and free E2F1 can induce transcription of several genes involved in cell cycle entry, induction or inhibition of apoptosis. Thus, growth factors and cytokines generally utilize E2F1 to direct cells to either fate. Furthermore, E2F1 regulates expressions of various cytokines and growth factor receptors, establishing positive or negative feedback mechanisms. This review focuses on the relationship between E2F1 transcription factor and cytokines (IL-1, IL-2, IL-3, IL-6, TGF-beta, G-CSF, LIF), growth factors (EGF, KGF, VEGF, IGF, FGF, PDGF, HGF, NGF), and interferons (IFN-α, IFN-β and IFN-γ). Copyright © 2016 Elsevier Ltd. All rights reserved.

Human papillomavirus type 16 E6 inhibits p21{sup WAF1} transcription independently of p53 by inactivating p150{sup Sal2}

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

Parroche, Peggy; Institut Federatif de Recherche 128 BioSciences Gerland-Lyon Sud; Touka, Majid

2011-09-01

HPV16 E6 deregulates G1/S cell cycle progression through p53 degradation preventing transcription of the CDK inhibitor p21{sup WAF1}. However, additional mechanisms independent of p53 inactivation appear to exist. Here, we report that HPV16 E6 targets the cellular factor p150{sup Sal2}, which positively regulates p21{sup WAF1} transcription. HPV16 E6 associates with p150{sup Sal2}, inducing its functional inhibition by preventing its binding to cis elements on the p21{sup WAF1} promoter. A HPV16 E6 mutant, L110Q, which was unable to bind p150{sup Sal2}, did not affect the ability of the cellular protein to bind p21{sup WAF1} promoter, underlining the linkage between these events.more » These data describe a novel mechanism by which HPV16 E6 induces cell cycle deregulation with a p53-independent pathway. The viral oncoprotein targets p150{sup Sal2}, a positive transcription regulator of p21{sup WAF1} gene, preventing G1/S arrest and allowing cellular proliferation and efficient viral DNA replication.« less

Deregulated activation of oncoprotein kinase Tpl2/Cot in HTLV-I-transformed T cells.

PubMed

Babu, Geetha; Waterfield, Michael; Chang, Mikyoung; Wu, Xuefeng; Sun, Shao-Cong

2006-05-19

Protein kinase Tpl2/Cot is encoded by a protooncogene that is cis-activated by retroviral insertion in murine T cell lymphomas. It has remained unclear whether this oncoprotein kinase is mutated or post-translationally activated in human cancer cells. We have shown here that Tpl2/Cot is constitutively activated in human leukemia cell lines transformed by the human T cell leukemia virus type I (HTLV-I). The kinase activity of Tpl2/Cot is normally suppressed through its physical interaction with an inhibitor, the NF-kappaB1 precursor protein p105. Interestingly, a large pool of Tpl2/Cot is liberated from p105 and exhibits constitutive kinase activity in HTLV-I-transformed T cells. In contrast to its labile property in normal cells, the pathologically activated Tpl2/Cot is remarkably stable. Further, whereas the physiological activation of Tpl2/Cot involves its long isoform, the HTLV-activated Tpl2/Cot is predominantly the short isoform. We have also shown that the HTLV-I-encoded Tax protein is able to activate Tpl2/Cot in transfected cells. Finally, Tpl2/Cot participates in the activation of NF-kappaB by Tax. These findings indicate that deregulated activation of Tpl2/Cot may occur in human cancer cells.

E2F1-mediated human POMC expression in ectopic Cushing's syndrome.

PubMed

Araki, Takako; Liu, Ning-Ai; Tone, Yukiko; Cuevas-Ramos, Daniel; Heltsley, Roy; Tone, Masahide; Melmed, Shlomo

2016-11-01

Cushing's syndrome is caused by excessive adrenocorticotropic hormone (ACTH) secretion derived from pituitary corticotroph tumors (Cushing disease) or from non-pituitary tumors (ectopic Cushing's syndrome). Hypercortisolemic features of ectopic Cushing's syndrome are severe, and no definitive treatment for paraneoplastic ACTH excess is available. We aimed to identify subcellular therapeutic targets by elucidating transcriptional regulation of the human ACTH precursor POMC (proopiomelanocortin) and ACTH production in non-pituitary tumor cells and in cell lines derived from patients with ectopic Cushing's syndrome. We show that ectopic hPOMC transcription proceeds independently of pituitary-specific Tpit/Pitx1 and demonstrate a novel E2F1-mediated transcriptional mechanism regulating hPOMC We identify an E2F1 cluster binding to the proximal hPOMC promoter region (-42 to +68), with DNA-binding activity determined by the phosphorylation at Ser-337. hPOMC mRNA expression in cancer cells was upregulated (up to 40-fold) by the co-expression of E2F1 and its heterodimer partner DP1. Direct and indirect inhibitors of E2F1 activity suppressed hPOMC gene expression and ACTH by modifying E2F1 DNA-binding activity in ectopic Cushing's cell lines and primary tumor cells, and also suppressed paraneoplastic ACTH and cortisol levels in xenografted mice. E2F1-mediated hPOMC transcription is a potential target for suppressing ACTH production in ectopic Cushing's syndrome. © 2016 Society for Endocrinology.

E2F transcription factor-1 deficiency reduces pathophysiology in the mouse model of Duchenne muscular dystrophy through increased muscle oxidative metabolism.

PubMed

Blanchet, Emilie; Annicotte, Jean-Sébastien; Pradelli, Ludivine A; Hugon, Gérald; Matecki, Stéfan; Mornet, Dominique; Rivier, François; Fajas, Lluis

2012-09-01

E2F1 deletion leads to increased mitochondrial number and function, increased body temperature in response to cold and increased resistance to fatigue with exercise. Since E2f1-/- mice show increased muscle performance, we examined the effect of E2f1 genetic inactivation in the mdx background, a mouse model of Duchenne muscular dystrophy (DMD). E2f1-/-;mdx mice demonstrated a strong reduction of physiopathological signs of DMD, including preservation of muscle structure, decreased inflammatory profile, increased utrophin expression, resulting in better endurance and muscle contractile parameters, comparable to normal mdx mice. E2f1 deficiency in the mdx genetic background increased the oxidative metabolic gene program, mitochondrial activity and improved muscle functions. Interestingly, we observed increased E2F1 protein levels in DMD patients, suggesting that E2F1 might represent a promising target for the treatment of DMD.

E2F8 is essential for polyploidization in mammalian cells.

PubMed

Pandit, Shusil K; Westendorp, Bart; Nantasanti, Sathidpak; van Liere, Elsbeth; Tooten, Peter C J; Cornelissen, Peter W A; Toussaint, Mathilda J M; Lamers, Wouter H; de Bruin, Alain

2012-11-01

Polyploidization is observed in all mammalian species and is a characteristic feature of hepatocytes, but its molecular mechanism and biological significance are unknown. Hepatocyte polyploidization in rodents occurs through incomplete cytokinesis, starts after weaning and increases with age. Here, we show in mice that atypical E2F8 is induced after weaning and required for hepatocyte binucleation and polyploidization. A deficiency in E2f8 led to an increase in the expression level of E2F target genes promoting cytokinesis and thereby preventing polyploidization. In contrast, loss of E2f1 enhanced polyploidization and suppressed the polyploidization defect of hepatocytes deficient for atypical E2Fs. In addition, E2F8 and E2F1 were found on the same subset of target promoters. Contrary to the long-standing hypothesis that polyploidization indicates terminal differentiation and senescence, we show that prevention of polyploidization through inactivation of atypical E2Fs has, surprisingly, no impact on liver differentiation, zonation, metabolism and regeneration. Together, these results identify E2F8 as a repressor and E2F1 as an activator of a transcriptional network controlling polyploidization in mammalian cells.

Synthesis and anti-tumor evaluation of panaxadiol halogen-derivatives.

PubMed

Xiao, Shengnan; Chen, Shuai; Sun, Yuanyuan; Zhou, Wuxi; Piao, Huri; Zhao, Yuqing

2017-09-01

In the current work, 13 novel panaxadiol (PD) derivatives were synthesized by reacting with chloroacetyl chloride and bromoacetyl bromide. Their in vitro antitumor activities were evaluated on three human tumor cell lines (HCT-116, BGC-823, SW-480) and three normal cells (human gastric epithelial cell line-GES-1, hair follicle dermal papilla cell line-HHDPC and rat myocardial cell line-H9C2) by MTT assay. Compared with PD, the results demonstrated that compound 1e, 2d, 2e showed significant anti-tumor activity against three tumor cell lines, the IC50 value of compound 2d against HCT-116 was the lowest (3.836μM). The anti-tumor activity of open-ring compounds are significantly better than the compounds of C-25 cyclization. Compound 1f, 2f, 2g showed the strong anti-tumor activity. The IC50 value of compound 2g against BGC-823 and SW-480 were the lowest (0.6μM and 0.1μM, respectively). Combined with cytotoxicity test, the IC50 value of compound 1e, 2d, 2e are greater than 100. the open-ring compounds (1f, 2f, 2g) showed a strong toxicity. The toxicity of 1f is lower than 2f and 2g. These compounds may be useful for the development of novel antiproliferative agents. Copyright © 2017. Published by Elsevier Ltd.

Defense Planning and Programming Categories: A Special Tool for Special Needs. Volume 3. Appendix E. Proposed Expanded DPPC Structure

DTIC Science & Technology

1990-04-01

SURVEILLANCE & WARNING SYTEMS A2C COMMAND & CONTROL ACTIVITIES A2D SPACE ACTIVITIES (STRATEGIC CONTROL & SURV) A2E STRAT CONTROL & SURV: COMMUNICATIONS A2F...STRATEGIC AIR DEFENSE 0501802A NIKE-AJAX (ARNS) (H) AID STRATEGIC AIR DEFENSE AIC SPACE DEFENSE OI02115N F-6 Squadrons (H) AIC SPACE DEFENSE 0102215N ABM ...WARNING SYTEMS 0102310F NCHC - TW/AA Systems A2B SURVEILLANCE & WARNIIIG SYTEMS 0102311F NCMC - Space Defense Systems A21 SURVEILLANCE & WARNING SYTEMS

Human papillomavirus (HPV) oncoprotein E6 facilitates Calcineurin-Nuclear factor for activated T cells 2 (NFAT2) signaling to promote cellular proliferation in cervical cell carcinoma.

PubMed

Ram, Babul Moni; Dolpady, Jayashree; Kulkarni, Rakesh; Usha, R; Bhoria, Usha; Poli, Usha Rani; Islam, Mojahidul; Trehanpati, Nirupma; Ramakrishna, Gayatri

2018-01-01

The calcineurin-NFAT signaling pathway regulates cell proliferation, differentiation, and development in diverse cell types and organ systems. Deregulation of calcineurin-NFAT signaling has been reported in leukaemias and few solid tumors such as breast and colon. In the present study, we found elevated calcineurin protein levels and phosphatase activity in cervical cancer cell lines and depletion of the same attenuated cell proliferation. Additionally, nuclear levels of NFAT2, a downstream target of calcineurin, viz, was found elevated in human papillomavirus (HPV) infected cells, HeLa and SiHa, compared to the HPV negative cells, HaCaT and C33A, indicative of its higher DNA binding activity. The nuclear levels of both NFAT1 and NFAT3 remain unaltered implicating they have little role in cervical carcinogenesis. Similar to the in vitro studies, the HPV infected human squamous cell carcinoma specimens showed higher NFAT2 levels compared to the normal cervical epithelium. Depletion of NFAT2 by RNAi attenuated growth of SiHa cells. Overexpression of HPV16 oncoproteins viz, E6 and E7 increased NFAT2 expression levels and DNA binding activity, while knockdown of E6 by RNAi decreased the same. Briefly, we now report an activation of calcineurin-NFAT2 axis in cervical cancer and a novel role of HPV oncoprotein in facilitating NFAT2 dependent cell proliferation. Copyright © 2017 Elsevier Inc. All rights reserved.

Bioactivity-guided isolation of spasmolytic components of Pycnocycla spinosa Decne ex Boiss.

PubMed

Sadraei, H; Asghari, G; Behzad, S

2011-07-01

Hydroalcoholic extract of Pycnocycla spinosa has spasmolytic effect in vitro and antidiarrhoeal action in vivo. The aim of this research was to separate fractions of total hydroalcoholic extract of P. spinosa guided by their spasmolytic activity. Aerial parts of P. spinosa were extracted with ethanol. The concentrated extract was subjected to column chromatography and thin layer chromatography. Initially four fractions were obtained (F1, F2, F3, and F4) and their spasmolytic activities were determined on ileum contraction induced by KCl (80 mM). The more active fraction was subjected to further isolation and tested to find its most active components. The active component was phytochemically characterized using phytochemical methods including ultraviolet and infrared spectroscopy. Hydroalcoholic extract of P. spinosa (10-320 μg/ml) in a concentration dependent manner inhibited ileum contraction with the IC(50) value of 47 ± 8.1 μg/ml (mean ± S.E.M., n=6). Fraction F2 was the most potent inhibitor of ileum contraction (IC(50)= 3.4 ± 0.33 μg/ml). From five sub-fractions separated from fraction F2 (F2a, F2b, F2c, F2d, and F2e, respectively), F2c was a more active component with the IC(50) value of 2.6 ± 0.27 μg/ml. The primary results of target fraction (F2c) showed sugar moiety in its structure or in one of its components. In this research we have isolated pharmacological active fraction which is most likely responsible for antispasmodic action of P. spinosa hydroalcoholic extract.

E2F1 somatic mutation within miRNA target site impairs gene regulation in colorectal cancer.

PubMed

Lopes-Ramos, Camila M; Barros, Bruna P; Koyama, Fernanda C; Carpinetti, Paola A; Pezuk, Julia; Doimo, Nayara T S; Habr-Gama, Angelita; Perez, Rodrigo O; Parmigiani, Raphael B

2017-01-01

Genetic studies have largely concentrated on the impact of somatic mutations found in coding regions, and have neglected mutations outside of these. However, 3' untranslated regions (3' UTR) mutations can also disrupt or create miRNA target sites, and trigger oncogene activation or tumor suppressor inactivation. We used next-generation sequencing to widely screen for genetic alterations within predicted miRNA target sites of oncogenes associated with colorectal cancer, and evaluated the functional impact of a new somatic mutation. Target sequencing of 47 genes was performed for 29 primary colorectal tumor samples. For 71 independent samples, Sanger methodology was used to screen for E2F1 mutations in miRNA predicted target sites, and the functional impact of these mutations was evaluated by luciferase reporter assays. We identified germline and somatic alterations in E2F1. Of the 100 samples evaluated, 3 had germline alterations at the MIR205-5p target site, while one had a somatic mutation at MIR136-5p target site. E2F1 gene expression was similar between normal and tumor tissues bearing the germline alteration; however, expression was increased 4-fold in tumor tissue that harbored a somatic mutation compared to that in normal tissue. Luciferase reporter assays revealed both germline and somatic alterations increased E2F1 activity relative to wild-type E2F1. We demonstrated that somatic mutation within E2F1:MIR136-5p target site impairs miRNA-mediated regulation and leads to increased gene activity. We conclude that somatic mutations that disrupt miRNA target sites have the potential to impact gene regulation, highlighting an important mechanism of oncogene activation.

STAT3 and STAT1 mediate IL-11–dependent and inflammation-associated gastric tumorigenesis in gp130 receptor mutant mice

PubMed Central

Ernst, Matthias; Najdovska, Meri; Grail, Dianne; Lundgren-May, Therese; Buchert, Michael; Tye, Hazel; Matthews, Vance B.; Armes, Jane; Bhathal, Prithi S.; Hughes, Norman R.; Marcusson, Eric G.; Karras, James G.; Na, Songqing; Sedgwick, Jonathon D.; Hertzog, Paul J.; Jenkins, Brendan J.

2008-01-01

Deregulated activation of STAT3 is frequently associated with many human hematological and epithelial malignancies, including gastric cancer. While exaggerated STAT3 signaling facilitates an antiapoptotic, proangiogenic, and proproliferative environment for neoplastic cells, the molecular mechanisms leading to STAT3 hyperactivation remain poorly understood. Using the gp130Y757F/Y757F mouse model of gastric cancer, which carries a mutated gp130 cytokine receptor signaling subunit that cannot bind the negative regulator of cytokine signaling SOCS3 and is characterized by hyperactivation of the signaling molecules STAT1 and STAT3, we have provided genetic evidence that IL-11 promotes chronic gastric inflammation and associated tumorigenesis. Expression of IL-11 was increased in gastric tumors in gp130Y757F/Y757F mice, when compared with unaffected gastric tissue in wild-type mice, while gp130Y757F/Y757F mice lacking the IL-11 ligand–binding receptor subunit (IL-11Rα) showed normal gastric STAT3 activation and IL-11 expression and failed to develop gastric tumors. Furthermore, reducing STAT3 activity in gp130Y757F/Y757F mice, either genetically or by therapeutic administration of STAT3 antisense oligonucleotides, normalized gastric IL-11 expression and alleviated gastric tumor burden. Surprisingly, the genetic reduction of STAT1 expression also reduced gastric tumorigenesis in gp130Y757F/Y757F mice and coincided with reduced gastric inflammation and IL-11 expression. Collectively, our data have identified IL-11 as a crucial cytokine promoting chronic gastric inflammation and associated tumorigenesis mediated by excessive activation of STAT3 and STAT1. PMID:18431520

Aberrantly Expressed OTX Homeobox Genes Deregulate B-Cell Differentiation in Hodgkin Lymphoma.

PubMed

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

2015-01-01

In Hodgkin lymphoma (HL) we recently reported that deregulated homeobox gene MSX1 mediates repression of the B-cell specific transcription factor ZHX2. In this study we investigated regulation of MSX1 in this B-cell malignancy. Accordingly, we analyzed expression and function of OTX homeobox genes which activate MSX1 transcription during embryonal development in the neural plate border region. Our data demonstrate that OTX1 and OTX2 are aberrantly expressed in both HL patients and cell lines. Moreover, both OTX loci are targeted by genomic gains in overexpressing cell lines. Comparative expression profiling and subsequent pathway modulations in HL cell lines indicated that aberrantly enhanced FGF2-signalling activates the expression of OTX2. Downstream analyses of OTX2 demonstrated transcriptional activation of genes encoding transcription factors MSX1, FOXC1 and ZHX1. Interestingly, examination of the physiological expression profile of ZHX1 in normal hematopoietic cells revealed elevated levels in T-cells and reduced expression in B-cells, indicating a discriminatory role in lymphopoiesis. Furthermore, two OTX-negative HL cell lines overexpressed ZHX1 in correlation with genomic amplification of its locus at chromosomal band 8q24, supporting the oncogenic potential of this gene in HL. Taken together, our data demonstrate that deregulated homeobox genes MSX1 and OTX2 respectively impact transcriptional inhibition of (B-cell specific) ZHX2 and activation of (T-cell specific) ZHX1. Thus, we show how reactivation of a specific embryonal gene regulatory network promotes disturbed B-cell differentiation in HL.

Identification of novel posttranscriptional targets of the BCR/ABL oncoprotein by ribonomics: requirement of E2F3 for BCR/ABL leukemogenesis

PubMed Central

Eiring, Anna M.; Neviani, Paolo; Santhanam, Ramasamy; Oaks, Joshua J.; Chang, Ji Suk; Notari, Mario; Willis, William; Gambacorti-Passerini, Carlo; Volinia, Stefano; Marcucci, Guido; Caligiuri, Michael A.; Leone, Gustavo W.

2008-01-01

Several RNA binding proteins (RBPs) have been implicated in the progression of chronic myelogenous leukemia (CML) from the indolent chronic phase to the aggressively fatal blast crisis. In the latter phase, expression and function of specific RBPs are aberrantly regulated at transcriptional or posttranslational levels by the constitutive kinase activity of the BCR/ABL oncoprotein. As a result, altered expression/function of RBPs leads to increased resistance to apoptotic stimuli, enhanced survival, growth advantage, and differentiation arrest of CD34+ progenitors from patients in CML blast crisis. Here, we identify the mRNAs bound to the hnRNP-A1, hnRNP-E2, hnRNP-K, and La/SSB RBPs in BCR/ABLtransformed myeloid cells. Interestingly, we found that the mRNA encoding the transcription factor E2F3 associates to hnRNP-A1 through a conserved binding site located in the E2F3 3′ untranslated region (UTR). E2F3 levels were up-regulated in CML-BCCD34+ in a BCR/ABL kinase– and hnRNP-A1 shuttling–dependent manner. Moreover, by using shRNA-mediated E2F3 knock-down and BCR/ABL-transduced lineage-negative bone marrow cells from E2F3+/+ and E2F3−/− mice, we show that E2F3 expression is important for BCR/ABL clonogenic activity and in vivo leukemogenic potential. Thus, the complexity of the mRNA/RBP network, together with the discovery of E2F3 as an hnRNP-A1–regulated factor, outlines the relevant role played by RBPs in posttranscriptional regulation of CML development and progression. PMID:17925491

Stochastic E2F activation and reconciliation of phenomenological cell-cycle models.

PubMed

Lee, Tae J; Yao, Guang; Bennett, Dorothy C; Nevins, Joseph R; You, Lingchong

2010-09-21

The transition of the mammalian cell from quiescence to proliferation is a highly variable process. Over the last four decades, two lines of apparently contradictory, phenomenological models have been proposed to account for such temporal variability. These include various forms of the transition probability (TP) model and the growth control (GC) model, which lack mechanistic details. The GC model was further proposed as an alternative explanation for the concept of the restriction point, which we recently demonstrated as being controlled by a bistable Rb-E2F switch. Here, through a combination of modeling and experiments, we show that these different lines of models in essence reflect different aspects of stochastic dynamics in cell cycle entry. In particular, we show that the variable activation of E2F can be described by stochastic activation of the bistable Rb-E2F switch, which in turn may account for the temporal variability in cell cycle entry. Moreover, we show that temporal dynamics of E2F activation can be recast into the frameworks of both the TP model and the GC model via parameter mapping. This mapping suggests that the two lines of phenomenological models can be reconciled through the stochastic dynamics of the Rb-E2F switch. It also suggests a potential utility of the TP or GC models in defining concise, quantitative phenotypes of cell physiology. This may have implications in classifying cell types or states.

Deregulation of E2-EPF Ubiquitin Carrier Protein in Papillary Renal Cell Carcinoma

PubMed Central

Roos, Frederik C.; Evans, Andrew J.; Brenner, Walburgis; Wondergem, Bill; Klomp, Jeffery; Heir, Pardeep; Roche, Olga; Thomas, Christian; Schimmel, Heiko; Furge, Kyle A.; Teh, Bin T.; Thüroff, Joachim W.; Hampel, Christian; Ohh, Michael

2011-01-01

Molecular pathways associated with pathogenesis of sporadic papillary renal cell carcinoma (PRCC), the second most common form of kidney cancer, are poorly understood. We analyzed primary tumor specimens from 35 PRCC patients treated by nephrectomy via gene expression analysis and tissue microarrays constructed from an additional 57 paraffin-embedded PRCC samples via immunohistochemistry. Gene products were validated and further studied by Western blot analyses using primary PRCC tumor samples and established renal cell carcinoma cell lines, and potential associations with pathologic variables and survival in 27 patients with follow-up information were determined. We show that the expression of E2-EPF ubiquitin carrier protein, which targets the principal negative regulator of hypoxia-inducible factor (HIF), von Hippel-Lindau protein, for proteasome-dependent degradation, is markedly elevated in the majority of PRCC tumors exhibiting increased HIF1α expression, and is associated with poor prognosis. In addition, we identified multiple hypoxia-responsive elements within the E2-EPF promoter, and for the first time we demonstrated that E2-EPF is a hypoxia-inducible gene directly regulated via HIF1. These findings reveal deregulation of the oxygen-sensing pathway impinging on the positive feedback mechanism of HIF1-mediated regulation of E2-EPF in PRCC. PMID:21281817

CDH1 regulates E2F1 degradation in response to differentiation signals in keratinocytes

PubMed Central

Singh, Randeep K.; Dagnino, Lina

2017-01-01

The E2F1 transcription factor plays key roles in skin homeostasis. In the epidermis, E2F1 expression is essential for normal proliferation of undifferentiated keratinocytes, regeneration after injury and DNA repair following UV radiation-induced photodamage. Abnormal E2F1 expression promotes nonmelanoma skin carcinoma. In addition, E2F1 must be downregulated for proper keratinocyte differentiation, but the relevant mechanisms involved remain poorly understood. We show that differentiation signals induce a series of post-translational modifications in E2F1 that are jointly required for its downregulation. Analysis of the structural determinants that govern these processes revealed a central role for S403 and T433. In particular, substitution of these two amino acid residues with non-phosphorylatable alanine (E2F1 ST/A) interferes with E2F1 nuclear export, K11- and K48-linked polyubiquitylation and degradation in differentiated keratinocytes. In contrast, replacement of S403 and T433 with phosphomimetic aspartic acid to generate a pseudophosphorylated E2F1 mutant protein (E2F1 ST/D) generates a protein that is regulated in a manner indistinguishable from that of wild type E2F1. Cdh1 is an activating cofactor that interacts with the anaphase-promoting complex/cyclosome (APC/C) ubiquitin E3 ligase, promoting proteasomal degradation of various substrates. We found that Cdh1 associates with E2F1 in keratinocytes. Inhibition or RNAi-mediated silencing of Cdh1 prevents E2F1 degradation in response to differentiation signals. Our results reveal novel regulatory mechanisms that jointly modulate post-translational modifications and downregulation of E2F1, which are necessary for proper epidermal keratinocyte differentiation. PMID:27903963

CDH1 regulates E2F1 degradation in response to differentiation signals in keratinocytes.

PubMed

Singh, Randeep K; Dagnino, Lina

2017-01-17

The E2F1 transcription factor plays key roles in skin homeostasis. In the epidermis, E2F1 expression is essential for normal proliferation of undifferentiated keratinocytes, regeneration after injury and DNA repair following UV radiation-induced photodamage. Abnormal E2F1 expression promotes nonmelanoma skin carcinoma. In addition, E2F1 must be downregulated for proper keratinocyte differentiation, but the relevant mechanisms involved remain poorly understood. We show that differentiation signals induce a series of post-translational modifications in E2F1 that are jointly required for its downregulation. Analysis of the structural determinants that govern these processes revealed a central role for S403 and T433. In particular, substitution of these two amino acid residues with non-phosphorylatable alanine (E2F1 ST/A) interferes with E2F1 nuclear export, K11- and K48-linked polyubiquitylation and degradation in differentiated keratinocytes. In contrast, replacement of S403 and T433 with phosphomimetic aspartic acid to generate a pseudophosphorylated E2F1 mutant protein (E2F1 ST/D) generates a protein that is regulated in a manner indistinguishable from that of wild type E2F1. Cdh1 is an activating cofactor that interacts with the anaphase-promoting complex/cyclosome (APC/C) ubiquitin E3 ligase, promoting proteasomal degradation of various substrates. We found that Cdh1 associates with E2F1 in keratinocytes. Inhibition or RNAi-mediated silencing of Cdh1 prevents E2F1 degradation in response to differentiation signals. Our results reveal novel regulatory mechanisms that jointly modulate post-translational modifications and downregulation of E2F1, which are necessary for proper epidermal keratinocyte differentiation.

Triptolide abrogates growth of colon cancer and induces cell cycle arrest by inhibiting transcriptional activation of E2F.

PubMed

Oliveira, Amanda; Beyer, Georg; Chugh, Rohit; Skube, Steven J; Majumder, Kaustav; Banerjee, Sulagna; Sangwan, Veena; Li, Lihua; Dawra, Rajinder; Subramanian, Subbaya; Saluja, Ashok; Dudeja, Vikas

2015-06-01

Despite significant progress in diagnostics and therapeutics, over 50 thousand patients die from colorectal cancer annually. Hence, there is urgent need for new lines of treatment. Triptolide, a natural compound isolated from the Chinese herb Tripterygium wilfordii, is effective against multiple cancers. We have synthesized a water soluble analog of triptolide, named Minnelide, which is currently in phase I trial against pancreatic cancer. The aims of the current study were to evaluate whether triptolide/Minnelide is effective against colorectal cancer and to elucidate the mechanism by which triptolide induces cell death in colorectal cancer. Efficacy of Minnelide was evaluated in subcutaneous xenograft and liver metastasis model of colorectal cancer. For mechanistic studies, colon cancer cell lines HCT116 and HT29 were treated with triptolide and the effect on viability, caspase activation, annexin positivity, lactate dehydrogenase release, and cell cycle progression was evaluated. Effect of triptolide on E2F transcriptional activity, mRNA levels of E2F-dependent genes, E2F1- retinoblastoma protein (Rb) binding, and proteins levels of regulator of G1-S transition was also measured. DNA binding of E2F1 was evaluated by chromatin immunoprecipitation assay. Triptolide decreased colon cancer cell viability in a dose- and time-dependent fashion. Minnelide markedly inhibited the growth of colon cancer in the xenograft and liver metastasis model of colon cancer and more than doubles the median survival of animals with liver metastases from colon cancer. Mechanistically, we demonstrate that at low concentrations triptolide induces apoptotic cell death but at higher concentrations it induces cell cycle arrest. Our data suggest that triptolide is able to induce G1 cell cycle arrest by inhibiting transcriptional activation of E2F1. Our data also show that triptolide downregulates E2F activity by potentially modulating events downstream of DNA binding. Therefore, we conclude that Triptolide and Minnelide are effective against colon cancer in multiple pre-clinical models.

Activation of H2 over the Ru-Zn Bond in the Transition Metal-Lewis Acid Heterobimetallic Species [Ru(IPr)2(CO)ZnEt](.).

PubMed

Riddlestone, Ian M; Rajabi, Nasir A; Lowe, John P; Mahon, Mary F; Macgregor, Stuart A; Whittlesey, Michael K

2016-09-07

Reaction of [Ru(IPr)2(CO)H]BAr(F)4 with ZnEt2 forms the heterobimetallic species [Ru(IPr)2(CO)ZnEt]BAr(F)4 (2), which features an unsupported Ru-Zn bond. 2 reacts with H2 to give [Ru(IPr)2(CO)(η(2)-H2)(H)2ZnEt]BAr(F)4 (3) and [Ru(IPr)2(CO)(H)2ZnEt]BAr(F)4 (4). DFT calculations indicate that H2 activation at 2 proceeds via oxidative cleavage at Ru with concomitant hydride transfer to Zn. 2 can also activate hydridic E-H bonds (E = B, Si), and computed mechanisms for the facile H/H exchange processes observed in 3 and 4 are presented.

HBV core promoter mutations promote cellular proliferation through E2F1-mediated upregulation of S-phase kinase-associated protein 2 transcription.

PubMed

Huang, Yuehua; Tai, Andrew W; Tong, Shuping; Lok, Anna S F

2013-06-01

Hepatitis B virus (HBV) core promoter (CP) mutations have been associated with an increased risk of hepatocellular carcinoma (HCC) in clinical studies. We previously reported that a combination of CP mutations seen in HCC patients, expressed in HBx gene, increased SKP2 (S-phase kinase-associated protein 2) expression, thereby promoting cellular proliferation. Here, we investigate the possible mechanisms by which CP mutations upregulate SKP2. We used immunoblotting and ATPlite assay to validate the effect of CP mutations in full-length HBV genome on cell cycle regulator levels and cell proliferation. Activation of SKP2 mRNA was assessed by quantitative real-time PCR in primary human hepatocytes (PHH) and HCC cell lines. Effect of CP mutations on SKP2 promoter activity was determined by luciferase assay. Target regulation of E2F1 on SKP2 was analyzed by siRNAs. CP mutations in full-length HBV genome upregulated SKP2 expression, thereby downregulating cell cycle inhibitors and accelerating cellular proliferation. CP mutations enhanced SKP2 promoter activity but had no effect on SKP2 protein stability. Mapping of the SKP2 promoter identified a region necessary for activation by CP mutations that contains an E2F1 response element. Knocking down E2F1 reduced the effects of CP mutations on SKP2 and cellular proliferation. The effect of CP mutations on E2F1 might be mediated through hyperphosphorylation of RB. HBV CP mutations enhance SKP2 transcription by activating the E2F1 transcription factor and in turn downregulate cell cycle inhibitors, thus providing a potential mechanism for an association between CP mutations and HCC. Copyright © 2013 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Tpbpa-Cre-mediated deletion of TFAP2C leads to deregulation of Cdkn1a, Akt1 and the ERK pathway, causing placental growth arrest.

PubMed

Sharma, Neha; Kubaczka, Caroline; Kaiser, Stephanie; Nettersheim, Daniel; Mughal, Sadaf S; Riesenberg, Stefanie; Hölzel, Michael; Winterhager, Elke; Schorle, Hubert

2016-03-01

Loss of TFAP2C in mouse leads to developmental defects in the extra-embryonic compartment with lethality at embryonic day (E)7.5. To investigate the requirement of TFAP2C in later placental development, deletion of TFAP2C was induced throughout extra-embryonic ectoderm at E6.5, leading to severe placental abnormalities caused by reduced trophoblast population and resulting in embryonic retardation by E8.5. Deletion of TFAP2C in TPBPA(+) progenitors at E8.5 results in growth arrest of the junctional zone. TFAP2C regulates its target genes Cdkn1a (previously p21) and Dusp6, which are involved in repression of MAPK signaling. Loss of TFAP2C reduces activation of ERK1/2 in the placenta. Downregulation of Akt1 and reduced activation of phosphorylated AKT in the mutant placenta are accompanied by impaired glycogen synthesis. Loss of TFAP2C led to upregulation of imprinted gene H19 and downregulation of Slc38a4 and Ascl2. The placental insufficiency post E16.5 causes fetal growth restriction, with 19% lighter mutant pups. Knockdown of TFAP2C in human trophoblast choriocarcinoma JAr cells inhibited MAPK and AKT signaling. Thus, we present a model where TFAP2C in trophoblasts controls proliferation by repressing Cdkn1a and activating the MAPK pathway, further supporting differentiation of glycogen cells by activating the AKT pathway. © 2016. Published by The Company of Biologists Ltd.

Therapeutic Strategies Against Cyclin E1 Amplified Ovarian Cancers

DTIC Science & Technology

2017-10-01

interaction and suppression of E2F- dependent oncogenic activity resulting in activity against CCNE1-amplified cells. In the third aim, we hypothesize...tumors which are dependent on hyperactive HR and are sensitive to suppression of BRCA1. 15. SUBJECT TERMS Ovarian Cancer, CCNE1 amplification...suppression of E2F- dependent oncogenic activity resulting in activity against CCNE1-amplified cells. In the third aim, we hypothesize that miR-1255b, miR

Ionospheric climatology at Africa EIA trough stations during descending phase of sunspot cycle 22

NASA Astrophysics Data System (ADS)

Adebesin, B. O.; Rabiu, A. B.; Bolaji, O. S.; Adeniyi, J. O.; Amory-Mazaudier, C.

2018-07-01

The African equatorial ionospheric climatology during the descending phase of sunspot-cycle 22 (spanning 1992-1996) was investigated using 3 ionosondes located at Dakar (14.70 N, 342.60 E), Ouagadougou (12.420 N, 358.60 E), and Korhogo (9.510 N, 354.40 E). The variations in the virtual height of the F-layer (h'F), maximum electron density (NmF2), vertical plasma drift (Vp) and zonal electric field (Ey) were presented. Significant decrease in the NmF2 amplitude compared to h'F in all of the stations during the descending period is obvious. While NmF2 magnitude maximizes/minimizes during the E-seasons/J-season, h'F attained highest/lowest altitude in J-season/D-season for all stations. D-season anomaly was evident in NmF2 at all stations. For any season, the intensity (Ibt) of NmF2 noon-bite-out is highest at Dakar owning to fountain effect and maximizes in March-E season. Stations across the EIA trough show nearly coherence ionospheric climatology characteristics whose difference is of latitudinal origin. Hemispheric dependence in NmF2 is obvious, with difference more significant during high-solar activity and closes with decreasing solar activity. The variability in the plasma drift during the entire phase is suggested to emanate from solar flux variations, and additionally from enhanced leakage of electric fields from high-to low-latitudes. Existing African regional model of evening/nightttime pre-reversal plasma drift/sunspot number (PREpeak/R) relationship compares well with experimental observations at all stations with slight over-estimation. The correlation/root-mean-square-deviation (RMSdev) pair between the model and observed Vp during the descending phase recorded 94.9%/0.756, 92.4%/1.526, and 79.1%/3.612 at Korhogo, Ouagadougou and Dakar respectively. The Ey/h'F and Ey/NmF2 relationships suggest that zonal electric field is more active in the lifting of h'F and suppression of NmF2 during high- and moderate-solar activities when compared with low-solar activity. This is the first work to show higher bite-out at the equatorial northern-station (Dakar) than southern-station (Korhogo) using ionosonde data.

Origin of bistability underlying mammalian cell cycle entry

PubMed Central

Yao, Guang; Tan, Cheemeng; West, Mike; Nevins, Joseph R; You, Lingchong

2011-01-01

Precise control of cell proliferation is fundamental to tissue homeostasis and differentiation. Mammalian cells commit to proliferation at the restriction point (R-point). It has long been recognized that the R-point is tightly regulated by the Rb–E2F signaling pathway. Our recent work has further demonstrated that this regulation is mediated by a bistable switch mechanism. Nevertheless, the essential regulatory features in the Rb–E2F pathway that create this switching property have not been defined. Here we analyzed a library of gene circuits comprising all possible link combinations in a simplified Rb–E2F network. We identified a minimal circuit that is able to generate robust, resettable bistability. This minimal circuit contains a feed-forward loop coupled with a mutual-inhibition feedback loop, which forms an AND-gate control of the E2F activation. Underscoring its importance, experimental disruption of this circuit abolishes maintenance of the activated E2F state, supporting its importance for the bistability of the Rb–E2F system. Our findings suggested basic design principles for the robust control of the bistable cell cycle entry at the R-point. PMID:21525871

E2F transcription factors and digestive system malignancies: how much do we know?

PubMed

Evangelou, Konstantinos; Havaki, Sophia; Kotsinas, Athanassios

2014-08-07

The E2F proteins comprise a family of 8 members that function as transcription factors. They are key targets of the retinoblastoma protein (RB) and were initially divided into groups of activators and repressors. Accumulating data suggest that there is no specific role for each individual E2F member. Instead, each E2F can exert a variety of cellular effects, some of which represent opposing ones. For instance, specific E2Fs can activate transcription and repression, promote or hamper cell proliferation, augment or inhibit apoptosis, all being dependent on the cellular context. This complexity reflects the importance that these transcription factors have on a cell's fate. Thus, delineating the specific role for each E2F member in specific malignancies, although not easy, is a challenging and continuously pursued task, especially in view of potential E2F targeted therapies. Therefore, several reviews are continuously trying to evaluate available data on E2F status in various malignancies. Such reviews have attempted to reach a consensus, often in the simplistic form of oncogenes or tumor suppressor genes for the E2Fs. However they frequently miss spatial and temporal alterations of these factors during tumor development, which should also be considered in conjunction with the status of the regulatory networks that these factors participate in. In the current ''Letter to the Editor'', we comment on the flaws, misinterpretations and omissions in one such review article published recently in the World Journal of Gastroenterology regarding the role of E2Fs in digestive system malignancies.

The Hippo component YAP localizes in the nucleus of human papilloma virus positive oropharyngeal squamous cell carcinoma.

PubMed

Alzahrani, Faisal; Clattenburg, Leanne; Muruganandan, Shanmugam; Bullock, Martin; MacIsaac, Kaitlyn; Wigerius, Michael; Williams, Blair A; Graham, M Elise R; Rigby, Matthew H; Trites, Jonathan R B; Taylor, S Mark; Sinal, Christopher J; Fawcett, James P; Hart, Robert D

2017-02-22

HPV infection causes cervical cancer, mediated in part by the degradation of Scribble via the HPV E6 oncoprotein. Recently, Scribble has been shown to be an important regulator of the Hippo signaling cascade. Deregulation of the Hippo pathway induces an abnormal cellular transformation, epithelial to mesenchymal transition, which promotes oncogenic progression. Given the recent rise in oropharyngeal HPV squamous cell carcinoma we sought to determine if Hippo signaling components are implicated in oropharyngeal squamous cell carcinoma. Molecular and cellular techniques including immunoprecipiations, Western blotting and immunocytochemistry were used to identify the key Hippo pathway effector Yes-Associated Protein (YAP)1. Oropharyngeal tissue was collected from CO 2 laser resections, and probed with YAP1 antibody in tumor and pre-malignant regions of HPV positive OPSCC tissue. This study reveals that the Scribble binding protein Nitric Oxide Synthase 1 Adaptor Protein (NOS1AP) forms a complex with YAP. Further, the NOS1APa and NOS1APc isoforms show differential association with activated and non-activated YAP, and impact cellular proliferation. Consistent with deregulated Hippo signaling in OPSCC HPV tumors, we see a delocalization of Scribble and increased nuclear accumulation of YAP1 in an HPV-positive OPSCC. Our preliminary data indicates that NOS1AP isoforms differentially associate with YAP1, which, together with our previous findings, predicts that loss of YAP1 enhances cellular transformation. Moreover, YAP1 is highly accumulated in the nucleus of HPV-positive OPSCC, implying that Hippo signaling and possibly NOS1AP expression are de-regulated in OPSCC. Further studies will help determine if NOS1AP isoforms, Scribble and Hippo components will be useful biomarkers in OPSCC tumor biology.

Metabolism of styrene to styrene oxide and vinylphenols in cytochrome P450 2F2- and P450 2E1-knockout mouse liver and lung microsomes

PubMed Central

Shen, Shuijie; Li, Lei; Ding, Xinxin; Zheng, Jiang

2014-01-01

Pulmonary toxicity of styrene is initiated by cytochromes P450-dependent metabolic activation. P450 2E1 and P450 2F2 are considered to be two main cytochrome P450 (CYP) enzymes responsible for styrene metabolism in mice. The objective of the current study was to determine the correlation between the formation of styrene metabolites (i.e. styrene oxide and 4-vinylphenol) and pulmonary toxicity of styrene, using Cyp2e1- and Cyp2f2-null mouse models. Dramatic decrease in the formation of styrene glycol and 4-vinylphenol was found in Cyp2f2-null mouse lung microsomes, relative to that in the wild-type mouse lung microsomes. However, no significant difference in the production of the styrene metabolites was observed between lung microsomes obtained from Cyp2e1-null and the wild-type mice. The knock–out and wild-type mice were treated with styrene (6.0 mmol/kg, ip), and cell counts and LDH activity in bronchoalveolar lavage fluids were monitored to evaluate the pulmonary toxicity induced by styrene. Cyp2e1-null mice displayed similar susceptibility to lung toxicity of styrene as the wild-type animals. However, Cyp2f2-null mice were resistant to styrene-induced pulmonary toxicity. In conclusion, both P450 2E1 and P450 2F2 are responsible for the metabolic activation of styrene. The latter enzyme plays an important role in styrene-induced pulmonary toxicity. Both styrene oxide and 4-vinylphenol are suggested to participate in the development of lung injury induced by styrene. PMID:24320693

Metabolism of styrene to styrene oxide and vinylphenols in cytochrome P450 2F2- and P450 2E1-knockout mouse liver and lung microsomes.

PubMed

Shen, Shuijie; Li, Lei; Ding, Xinxin; Zheng, Jiang

2014-01-21

Pulmonary toxicity of styrene is initiated by cytochromes P450-dependent metabolic activation. P450 2E1 and P450 2F2 are considered to be two main cytochrome P450 enzymes responsible for styrene metabolism in mice. The objective of the current study was to determine the correlation between the formation of styrene metabolites (i.e., styrene oxide and 4-vinylphenol) and pulmonary toxicity of styrene, using Cyp2e1- and Cyp2f2-null mouse models. A dramatic decrease in the formation of styrene glycol and 4-vinylphenol was found in Cyp2f2-null mouse lung microsomes relative to that in the wild-type mouse lung microsomes; however, no significant difference in the production of the styrene metabolites was observed between lung microsomes obtained from Cyp2e1-null and the wild-type mice. The knockout and wild-type mice were treated with styrene (6.0 mmol/kg, ip), and cell counts and LDH activity in bronchoalveolar lavage fluids were monitored to evaluate the pulmonary toxicity induced by styrene. Cyp2e1-null mice displayed a susceptibility to lung toxicity of styrene similar to that of the wild-type animals; however, Cyp2f2-null mice were resistant to styrene-induced pulmonary toxicity. In conclusion, both P450 2E1 and P450 2F2 are responsible for the metabolic activation of styrene. The latter enzyme plays an important role in styrene-induced pulmonary toxicity. Both styrene oxide and 4-vinylphenol are suggested to participate in the development of lung injury induced by styrene.

Exposure to Endocrine Disruptor Induces Transgenerational Epigenetic Deregulation of MicroRNAs in Primordial Germ Cells

PubMed Central

Brieño-Enríquez, Miguel A.; García-López, Jesús; Cárdenas, David B.; Guibert, Sylvain; Cleroux, Elouan; Děd, Lukas; Hourcade, Juan de Dios; Pěknicová, Jana; Weber, Michael; del Mazo, Jesús

2015-01-01

In mammals, germ cell differentiation is initiated in the Primordial Germ Cells (PGCs) during fetal development. Prenatal exposure to environmental toxicants such as endocrine disruptors may alter PGC differentiation, development of the male germline and induce transgenerational epigenetic disorders. The anti-androgenic compound vinclozolin represents a paradigmatic example of molecule causing transgenerational effects on germ cells. We performed prenatal exposure to vinclozolin in mice and analyzed the phenotypic and molecular changes in three successive generations. A reduction in the number of embryonic PGCs and increased rate of apoptotic cells along with decrease of fertility rate in adult males were observed in F1 to F3 generations. Blimp1 is a crucial regulator of PGC differentiation. We show that prenatal exposure to vinclozolin deregulates specific microRNAs in PGCs, such as miR-23b and miR-21, inducing disequilibrium in the Lin28/let-7/Blimp1 pathway in three successive generations of males. As determined by global maps of cytosine methylation, we found no evidence for prominent changes in DNA methylation in PGCs or mature sperm. Our data suggest that embryonic exposure to environmental endocrine disruptors induces transgenerational epigenetic deregulation of expression of microRNAs affecting key regulatory pathways of germ cells differentiation. PMID:25897752

Synthesis and evaluation of curcumin-related compounds for anticancer activity.

PubMed

Wei, Xingchuan; Du, Zhi-Yun; Zheng, Xi; Cui, Xiao-Xing; Conney, Allan H; Zhang, Kun

2012-07-01

Sixty-one curcumin-related compounds were synthesized and evaluated for their anticancer activity toward cultured prostate cancer PC-3 cells, pancreas cancer Panc-1 cells and colon cancer HT-29 cells. Inhibitory effects of these compounds on the growth of PC-3, Panc-1 and HT-29 cells were determined by the MTT assay. Compounds E10, F10, FN1 and FN2 exhibited exceptionally potent inhibitory effects on the growth of cultured PC-3, Panc-1 and HT-29 cells. The IC(50) for these compounds was lower than 1 μM in all three cell lines. E10 was 72-, 46- and 117-fold more active than curcumin for inhibiting the growth of PC-3, Panc-1 and HT-29 cells, respectively. F10 was 69-, 34- and 72-fold more active than curcumin for inhibiting the growth of PC-3, Panc-1 and HT-29 cells, respectively. FN1 and FN2 had about the same inhibitory effect as E10 and F10 toward Panc-1 cells but were less active than E10 and F10 toward PC-3 and HT-29 cells. The active compounds were potent stimulators of apoptosis. The present study indicates that E10, F10, FN1 and FN2 may have useful anticancer activity. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

HTLV Deregulation of the NF-κB Pathway: An Update on Tax and Antisense Proteins Role.

PubMed

Fochi, Stefania; Mutascio, Simona; Bertazzoni, Umberto; Zipeto, Donato; Romanelli, Maria G

2018-01-01

Human T-cell lymphotropic virus type 1 (HTLV-1) is the causative agent of adult T-cell leukemia (ATL), an aggressive CD4 + /CD25 + T-cell malignancy and of a severe neurodegenerative disease, HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP). The chronic activation or deregulation of the canonical and non-canonical nuclear factor kappa B (NF-κB) pathways play a crucial role in tumorigenesis. The HTLV-1 Tax-1 oncoprotein is a potent activator of the NF-κB transcription factors and the NF-κB response is required for promoting the development of HTLV-1 transformed cell lines. The homologous retrovirus HTLV-2, which also expresses a Tax-2 transforming protein, is not associated with ATL. In this review, we provide an updated synopsis of the role of Tax-1 in the deregulation of the NF-κB pathway, highlighting the differences with the homologous Tax-2. Special emphasis is directed toward the understanding of the molecular mechanisms involved in NF-κB activation resulting from Tax interaction with host factors affecting several cellular processes, such as cell cycle, apoptosis, senescence, cell proliferation, autophagy, and post-translational modifications. We also discuss the current knowledge on the role of the antisense viral protein HBZ in down-regulating the NF-κB activation induced by Tax, and its implication in cellular senescence. In addition, we review the recent studies on the mechanism of HBZ-mediated inhibition of NF-κB activity as compared to that exerted by the HTLV-2 antisense protein, APH-2. Finally, we discuss recent advances aimed at understanding the role exerted in the development of ATL by the perturbation of NF-κB pathway by viral regulatory proteins.

HTLV Deregulation of the NF-κB Pathway: An Update on Tax and Antisense Proteins Role

PubMed Central

Fochi, Stefania; Mutascio, Simona; Bertazzoni, Umberto; Zipeto, Donato; Romanelli, Maria G.

2018-01-01

Human T-cell lymphotropic virus type 1 (HTLV-1) is the causative agent of adult T-cell leukemia (ATL), an aggressive CD4+/CD25+ T-cell malignancy and of a severe neurodegenerative disease, HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP). The chronic activation or deregulation of the canonical and non-canonical nuclear factor kappa B (NF-κB) pathways play a crucial role in tumorigenesis. The HTLV-1 Tax-1 oncoprotein is a potent activator of the NF-κB transcription factors and the NF-κB response is required for promoting the development of HTLV-1 transformed cell lines. The homologous retrovirus HTLV-2, which also expresses a Tax-2 transforming protein, is not associated with ATL. In this review, we provide an updated synopsis of the role of Tax-1 in the deregulation of the NF-κB pathway, highlighting the differences with the homologous Tax-2. Special emphasis is directed toward the understanding of the molecular mechanisms involved in NF-κB activation resulting from Tax interaction with host factors affecting several cellular processes, such as cell cycle, apoptosis, senescence, cell proliferation, autophagy, and post-translational modifications. We also discuss the current knowledge on the role of the antisense viral protein HBZ in down-regulating the NF-κB activation induced by Tax, and its implication in cellular senescence. In addition, we review the recent studies on the mechanism of HBZ-mediated inhibition of NF-κB activity as compared to that exerted by the HTLV-2 antisense protein, APH-2. Finally, we discuss recent advances aimed at understanding the role exerted in the development of ATL by the perturbation of NF-κB pathway by viral regulatory proteins. PMID:29515558

Repression of transcriptional activity of C/EBPalpha by E2F-dimerization partner complexes.

PubMed

Zaragoza, Katrin; Bégay, Valérie; Schuetz, Anja; Heinemann, Udo; Leutz, Achim

2010-05-01

The transcription factor CCAAT/enhancer-binding protein alpha (C/EBPalpha) coordinates proliferation arrest and the differentiation of myeloid progenitors, adipocytes, hepatocytes, keratinocytes, and cells of the lung and placenta. C/EBPalpha transactivates lineage-specific differentiation genes and inhibits proliferation by repressing E2F-regulated genes. The myeloproliferative C/EBPalpha BRM2 mutant serves as a paradigm for recurrent human C-terminal bZIP C/EBPalpha mutations that are involved in acute myeloid leukemogenesis. BRM2 fails to repress E2F and to induce adipogenesis and granulopoiesis. The data presented here show that, independently of pocket proteins, C/EBPalpha interacts with the dimerization partner (DP) of E2F and that C/EBPalpha-E2F/DP interaction prevents both binding of C/EBPalpha to its cognate sites on DNA and transactivation of C/EBP target genes. The BRM2 mutant, in addition, exhibits enhanced interaction with E2F-DP and reduced affinity toward DNA and yet retains transactivation potential and differentiation competence that becomes exposed when E2F/DP levels are low. Our data suggest a tripartite balance between C/EBPalpha, E2F/DP, and pocket proteins in the control of proliferation, differentiation, and tumorigenesis.

Transformation of arachidonate into 6-oxoprostaglandin F1 alpha, thromboxane B2 and prostaglandin E2 by sheep lung microsomal fraction.

PubMed Central

Tai, H H; Yuan, B; Wu, A T

1978-01-01

In the presence of haemoglobin and isoproterenol, the microsomal fraction of sheep lung catalysed the conversion of arachidonate predominantly into thromboxane B2 and to a lesser extent into 6-oxoprostaglandin F1alpha. Very little prostaglandin E2 and prostaglandin F2alpha were formed. If reduced glutathione was added in combination with haemoglobin and isoproterenol, the synthesis of prostaglandin E2 was favoured over that of thromboxane B2 and 6-oxoprostaglandin F1alpha. The identities of these products were confirmed by t.l.c. and by combined g.l.c.-mass spectrometry. These results indicate that microsomal fraction of sheep lung possesses active prostaglandin synthase, prostacyclin synthase and thromboxane synthase activities. PMID:637853

Replication initiator protein RepE of mini-F plasmid: functional differentiation between monomers (initiator) and dimers (autogenous repressor).

PubMed Central

Ishiai, M; Wada, C; Kawasaki, Y; Yura, T

1994-01-01

Replication of mini-F plasmid requires the plasmid-encoded RepE initiator protein and several host factors including DnaJ, DnaK, and GrpE, heat shock proteins of Escherichia coli. The RepE protein plays a crucial role in replication and exhibits two major functions: initiation of replication from the origin, ori2, and autogenous repression of repE transcription. One of the mini-F plasmid mutants that can replicate in the dnaJ-defective host produces an altered RepE (RepE54) with a markedly enhanced initiator activity but little or no repressor activity. RepE54 has been purified from cell extracts primarily in monomeric form, unlike the wild-type RepE that is recovered in dimeric form. Gel-retardation assays revealed that RepE54 monomers bind to ori2 (direct repeats) with a very high efficiency but hardly bind to the repE operator (inverted repeat), in accordance with the properties of RepE54 in vivo. Furthermore, the treatment of wild-type RepE dimers with protein denaturants enhanced their binding to ori2 but reduced binding to the operator: RepE dimers were partially converted to monomers, and the ori2 binding activity was uniquely associated with monomers. These results strongly suggest that RepE monomers represent an active form by binding to ori2 to initiate replication, whereas dimers act as an autogenous repressor by binding to the operator. We propose that RepE is structurally and functionally differentiated and that monomerization of RepE dimers, presumably mediated by heat shock protein(s), activates the initiator function and participates in regulation of mini-F DNA replication. Images PMID:8170998

Novel Tacrine-Based Pyrano[3',4':5,6]pyrano[2,3-b]quinolinones: Synthesis and Cholinesterase Inhibitory Activity.

PubMed

Hariri, Roshanak; Afshar, Zahra; Mahdavi, Mohammad; Safavi, Maliheh; Saeedi, Mina; Najafi, Zahra; Sabourian, Reyhaneh; Karimpour-Razkenari, Elahe; Edraki, Najmeh; Moghadam, Farshad Homayouni; Shafiee, Abbas; Khanavi, Mahnaz; Akbarzadeh, Tahmineh

2016-12-01

In order to develop effective anti-cholinesterase compounds, a novel series of pyrano[3',4':5,6]pyrano[2,3-b]quinolinones were designed, synthesized, and evaluated in vitro against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). All derivatives showed very good AChE inhibitory (AChEI) activity (IC 50  = 0.37-5.62 μM) compared with rivastigmine (IC 50  = 11.07 μM). Among them, 11-amino-12-(2,3-dichlorophenyl)-3-methyl-7,8,9,10-tetrahydropyrano[3',4':5,6]pyrano[2,3-b]quinolin-1(12H)-one (6f) displayed the best inhibitory activity. However, most of the synthesized compounds showed no anti-BChE activity and compounds 6b and 6f were found to be only moderate inhibitors. The most potent anti-AChE compound 6f had low and moderate inhibitory activity and neuroprotective effects against beta-secretase (BACE1) and oxidative stress-induced cell death, respectively. Also, kinetic and molecular docking studies of binding interactions elucidated that compound 6f bound to both the catalytic anionic site (CAS) and peripheral anionic site (PAS) of AChE. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

AMP-activated protein kinase α2 and E2F1 transcription factor mediate doxorubicin-induced cytotoxicity by forming a positive signal loop in mouse embryonic fibroblasts and non-carcinoma cells.

PubMed

Yang, Wookyeom; Park, In-Ja; Yun, Hee; Im, Dong-Uk; Ock, Sangmi; Kim, Jaetaek; Seo, Seon-Mi; Shin, Ha-Yeon; Viollet, Benoit; Kang, Insug; Choe, Wonchae; Kim, Sung-Soo; Ha, Joohun

2014-02-21

Doxorubicin is one of the most widely used anti-cancer drugs, but its clinical application is compromised by severe adverse effects in different organs including cardiotoxicity. In the present study we explored mechanisms of doxorubicin-induced cytotoxicity by revealing a novel role for the AMP-activated protein kinase α2 (AMPKα2) in mouse embryonic fibroblasts (MEFs). Doxorubicin robustly induced the expression of AMPKα2 in MEFs but slightly reduced AMPKα1 expression. Our data support the previous notion that AMPKα1 harbors survival properties under doxorubicin treatment. In contrast, analyses of Ampkα2(-/-) MEFs, gene knockdown of AMPKα2 by shRNA, and inhibition of AMPKα2 activity with an AMPK inhibitor indicated that AMPKα2 functions as a pro-apoptotic molecule under doxorubicin treatment. Doxorubicin induced AMPKα2 at the transcription level via E2F1, a transcription factor that regulates apoptosis in response to DNA damage. E2F1 directly transactivated the Ampkα2 gene promoter. In turn, AMPKα2 significantly contributed to stabilization and activation of E2F1 by doxorubicin, forming a positive signal amplification loop. AMPKα2 directly interacted with and phosphorylated E2F1. This signal loop was also detected in H9c2, C2C12, and ECV (human epithelial cells) cells as well as mouse liver under doxorubicin treatment. Resveratrol, which has been suggested to attenuate doxorubicin-induced cytotoxicity, significantly blocked induction of AMPKα2 and E2F1 by doxorubicin, leading to protection of these cells. This signal loop appears to be non-carcinoma-specific because AMPKα2 was not induced by doxorubicin in five different tested cancer cell lines. These results suggest that AMPKα2 may serve as a novel target for alleviating the cytotoxicity of doxorubicin.

O-GlcNAcylation affects β-catenin and E-cadherin expression, cell motility and tumorigenicity of colorectal cancer.

PubMed

Harosh-Davidovich, Shani Ben; Khalaila, Isam

2018-03-01

O-GlcNAcylation, the addition of β-N-acetylglucosamine (O-GlcNAc) moiety to Ser/Thr residues, is a sensor of the cell metabolic state. Cancer diseases such as colon, lung and breast cancer, possess deregulated O-GlcNAcylation. Studies during the last decade revealed that O-GlcNAcylation is implicated in cancer tumorigenesis and proliferation. The Wnt/β-catenin signaling pathway and cadherin-mediated adhesion are also implicated in epithelial-mesenchymal transition (EMT), a key cellular process in invasion and cancer metastasis. Often, deregulation of the Wnt pathway is caused by altered phosphorylation of its components. Specifically, phosphorylation of Ser or Thr residues of β-catenin affects its location and interaction with E-cadherin, thus facilitating cell-cell adhesion. Consistent with previous studies, the current study indicates that β-catenin is O-GlcNAcylated. To test the effect of O-GlcNAcylation on cell motility and how O-GlcNAcylation might affect β-catenin and E-cadherin functions, the enzyme machinery of O-GlcNAcylation was modulated either with chemical inhibitors or by gene silencing. When O-GlcNAcase (OGA) was inhibited, a global elevation of protein O-GlcNAcylation and increase in the expression of E-cadherin and β-catenin were noted. Concomitantly with enhanced O-GlcNAcylation, β-catenin transcriptional activity were elevated. Additionally, fibroblast cell motility was enhanced. Stable silenced cell lines with adenoviral OGA or adenoviral O-GlcNAc transferase (OGT) were established. Consistent with the results obtained by OGA chemical inhibition by TMG, OGT-silencing led to a significant reduction in β-catenin level. In vivo, murine orthotropic colorectal cancer model indicates that elevated O-GlcNAcylation leads to increased mortality rate, tumor and metastasis development. However, reduction in O-GlcNAcylation promoted survival that could be attributed to attenuated tumor and metastasis development. The results described herein provide circumstantial clues that O-GlcNAcylation deregulates β-catenin and E-cadherin expression and activity in fibroblast cell lines and this might influence EMT and cell motility, which may further influence tumor development and metastasis. Copyright © 2018 Elsevier Inc. All rights reserved.

Inhibition of ATP Hydrolysis by Thermoalkaliphilic F1Fo-ATP Synthase Is Controlled by the C Terminus of the ɛ Subunit

PubMed Central

Keis, Stefanie; Stocker, Achim; Dimroth, Peter; Cook, Gregory M.

2006-01-01

The F1Fo-ATP synthases of alkaliphilic bacteria exhibit latent ATPase activity, and for the thermoalkaliphile Bacillus sp. strain TA2.A1, this activity is intrinsic to the F1 moiety. To study the mechanism of ATPase inhibition, we developed a heterologous expression system in Escherichia coli to produce TA2F1 complexes from this thermoalkaliphile. Like the native F1Fo-ATP synthase, the recombinant TA2F1 was blocked in ATP hydrolysis activity, and this activity was stimulated by the detergent lauryldimethylamine oxide. To determine if the C-terminal domain of the ɛ subunit acts as an inhibitor of ATPase activity and if an electrostatic interaction plays a role, a TA2F1 mutant with either a truncated ɛ subunit [i.e., TA2F1(ɛΔC)] or substitution of basic residues in the second α-helix of ɛ with nonpolar alanines [i.e., TA2F1(ɛ6A)] was constructed. Both mutants showed ATP hydrolysis activity at low and high concentrations of ATP. Treatment of the purified F1Fo-ATP synthase and TA2F1(ɛWT) complex with proteases revealed that the ɛ subunit was resistant to proteolytic digestion. In contrast, the ɛ subunit of TA2F1(ɛ6A) was completely degraded by trypsin, indicating that the C-terminal arm was in a conformation where it was no longer protected from proteolytic digestion. In addition, ATPase activity was not further activated by protease treatment when compared to the untreated control, supporting the observation that ɛ was responsible for inhibition of ATPase activity. To study the effect of the alanine substitutions in the ɛ subunit in the entire holoenzyme, we reconstituted recombinant TA2F1 complexes with F1-stripped native membranes of strain TA2.A1. The reconstituted TA2FoF1(ɛWT) was blocked in ATP hydrolysis and exhibited low levels of ATP-driven proton pumping consistent with the F1Fo-ATP synthase in native membranes. Reconstituted TA2FoF1(ɛ6A) exhibited ATPase activity that correlated with increased ATP-driven proton pumping, confirming that the ɛ subunit also inhibits ATPase activity of TA2FoF1. PMID:16707672

KDM4A Coactivates E2F1 to Regulate the PDK-Dependent Metabolic Switch between Mitochondrial Oxidation and Glycolysis.

PubMed

Wang, Ling-Yu; Hung, Chiu-Lien; Chen, Yun-Ru; Yang, Joy C; Wang, Junjian; Campbell, Mel; Izumiya, Yoshihiro; Chen, Hong-Wu; Wang, Wen-Ching; Ann, David K; Kung, Hsing-Jien

2016-09-13

The histone lysine demethylase KDM4A/JMJD2A has been implicated in prostate carcinogenesis through its role in transcriptional regulation. Here, we describe KDM4A as a E2F1 coactivator and demonstrate a functional role for the E2F1-KDM4A complex in the control of tumor metabolism. KDM4A associates with E2F1 on target gene promoters and enhances E2F1 chromatin binding and transcriptional activity, thereby modulating the transcriptional profile essential for cancer cell proliferation and survival. The pyruvate dehydrogenase kinases (PDKs) PDK1 and PDK3 are direct targets of KDM4A and E2F1 and modulate the switch between glycolytic metabolism and mitochondrial oxidation. Downregulation of KDM4A leads to elevated activity of pyruvate dehydrogenase and mitochondrial oxidation, resulting in excessive accumulation of reactive oxygen species. The altered metabolic phenotypes can be partially rescued by ectopic expression of PDK1 and PDK3, indicating a KDM4A-dependent tumor metabolic regulation via PDK. Our results suggest that KDM4A is a key regulator of tumor metabolism and a potential therapeutic target for prostate cancer. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

Integrative Genome-Scale Analysis Identifies Epigenetic Mechanisms of Transcriptional Deregulation in Unfavorable Neuroblastomas.

PubMed

Henrich, Kai-Oliver; Bender, Sebastian; Saadati, Maral; Dreidax, Daniel; Gartlgruber, Moritz; Shao, Chunxuan; Herrmann, Carl; Wiesenfarth, Manuel; Parzonka, Martha; Wehrmann, Lea; Fischer, Matthias; Duffy, David J; Bell, Emma; Torkov, Alica; Schmezer, Peter; Plass, Christoph; Höfer, Thomas; Benner, Axel; Pfister, Stefan M; Westermann, Frank

2016-09-15

The broad clinical spectrum of neuroblastoma ranges from spontaneous regression to rapid progression despite intensive multimodal therapy. This diversity is not fully explained by known genetic aberrations, suggesting the possibility of epigenetic involvement in pathogenesis. In pursuit of this hypothesis, we took an integrative approach to analyze the methylomes, transcriptomes, and copy number variations in 105 cases of neuroblastoma, complemented by primary tumor- and cell line-derived global histone modification analyses and epigenetic drug treatment in vitro We found that DNA methylation patterns identify divergent patient subgroups with respect to survival and clinicobiologic variables, including amplified MYCN Transcriptome integration and histone modification-based definition of enhancer elements revealed intragenic enhancer methylation as a mechanism for high-risk-associated transcriptional deregulation. Furthermore, in high-risk neuroblastomas, we obtained evidence for cooperation between PRC2 activity and DNA methylation in blocking tumor-suppressive differentiation programs. Notably, these programs could be re-activated by combination treatments, which targeted both PRC2 and DNA methylation. Overall, our results illuminate how epigenetic deregulation contributes to neuroblastoma pathogenesis, with novel implications for its diagnosis and therapy. Cancer Res; 76(18); 5523-37. ©2016 AACR. ©2016 American Association for Cancer Research.

Therapeutic correction of ApoER2 splicing in Alzheimer's disease mice using antisense oligonucleotides.

PubMed

Hinrich, Anthony J; Jodelka, Francine M; Chang, Jennifer L; Brutman, Daniella; Bruno, Angela M; Briggs, Clark A; James, Bryan D; Stutzmann, Grace E; Bennett, David A; Miller, Steven A; Rigo, Frank; Marr, Robert A; Hastings, Michelle L

2016-04-01

Apolipoprotein E receptor 2 (ApoER2) is an apolipoprotein E receptor involved in long-term potentiation, learning, and memory. Given its role in cognition and its association with the Alzheimer's disease (AD) risk gene, apoE, ApoER2 has been proposed to be involved in AD, though a role for the receptor in the disease is not clear. ApoER2 signaling requires amino acids encoded by alternatively spliced exon 19. Here, we report that the balance of ApoER2 exon 19 splicing is deregulated in postmortem brain tissue from AD patients and in a transgenic mouse model of AD To test the role of deregulated ApoER2 splicing in AD, we designed an antisense oligonucleotide (ASO) that increases exon 19 splicing. Treatment of AD mice with a single dose of ASO corrected ApoER2 splicing for up to 6 months and improved synaptic function and learning and memory. These results reveal an association between ApoER2 isoform expression and AD, and provide preclinical evidence for the utility of ASOs as a therapeutic approach to mitigate Alzheimer's disease symptoms by improving ApoER2 exon 19 splicing. © 2016 The Authors. Published under the terms of the CC BY 4.0 license.

The Drosophila FTZ-F1 Nuclear Receptor Mediates Juvenile Hormone Activation of E75A Gene Expression through an Intracellular Pathway*

PubMed Central

Dubrovsky, Edward B.; Dubrovskaya, Veronica A.; Bernardo, Travis; Otte, Valerie; DiFilippo, Robert; Bryan, Heather

2011-01-01

Juvenile hormone (JH) regulates a wide variety of biological activities in holometabolous insects, ranging from vitellogenesis and caste determination in adults to the timing of metamorphosis in larvae. The mechanism of JH signaling in such a diverse array of processes remains either unknown or contentious. We previously found that the nuclear receptor gene E75A is activated in S2 cells as a primary response to JH. Here, by expressing an intracellular form of JH esterase, we demonstrate that JH must enter the cell in order to activate E75A. To find intracellular receptors involved in the JH response, we performed an RNAi screen against nuclear receptor genes expressed in this cell line and identified the orphan receptor FTZ-F1. Removal of FTZ-F1 prevents JH activation of E75A, whereas overexpression enhances activation, implicating FTZ-F1 as a critical component of the JH response. FTZ-F1 is bound in vivo to multiple enhancers upstream of E75A, suggesting that it participates in direct JH-mediated gene activation. To better define the role of FTZ-F1 in JH signaling, we investigated interactions with candidate JH receptors and found that the bHLH-PAS proteins MET and GCE both interact with FTZ-F1 and can activate transcription through the FTZ-F1 response element. Removal of endogenous GCE, but not MET, prevents JH activation of E75A. We propose that FTZ-F1 functions as a competence factor by loading JH signaling components to the promoter, thus facilitating the direct regulation of E75A gene expression by JH. PMID:21832074

DEPDC1 promotes cell proliferation and tumor growth via activation of E2F signaling in prostate cancer.

PubMed

Huang, Lin; Chen, Keng; Cai, Zhao-Peng; Chen, Fu-Chao; Shen, Hui-Yong; Zhao, Wei-Hua; Yang, Song-Jie; Chen, Xu-Biao; Tang, Guo-Xue; Lin, Xi

2017-08-26

DEP domain containing 1 (DEPDC1) is recently reported to be overexpressed in several types of human cancer; however the role of DEPDC1 in prostate cancer remains to be investigated. Herein, we identified that the DEPDC1 mRNA and protein expression levels were dramatically increased in prostate cancer tissues and cell lines. Overexpression of DEPDC1 promoted, but depletion of DEPDC1 inhibited cell proliferation by regulating the G1-S phase cell cycle transition. Importantly, we found that DEPDC1 was essential for the tumor growth and formation of bone metastases of prostate cancer cells in vivo. Finally, we demonstrated that DEPDC1 interacted with E2F1 and increased its transcriptional activity, leading to hyper-activation of E2F signaling in prostate cancer cells. Our findings reveal an oncogenic role of DEPDC1 in prostate cancer progression via activation of E2F signaling, and suggest DEPDC1 might be a potential therapeutic target against the disease. Copyright © 2017 Elsevier Inc. All rights reserved.

Identifying environmental sounds: a multimodal mapping study

PubMed Central

Tomasino, Barbara; Canderan, Cinzia; Marin, Dario; Maieron, Marta; Gremese, Michele; D'Agostini, Serena; Fabbro, Franco; Skrap, Miran

2015-01-01

Our environment is full of auditory events such as warnings or hazards, and their correct recognition is essential. We explored environmental sounds (ES) recognition in a series of studies. In study 1 we performed an Activation Likelihood Estimation (ALE) meta-analysis of neuroimaging experiments addressing ES processing to delineate the network of areas consistently involved in ES processing. Areas consistently activated in the ALE meta-analysis were the STG/MTG, insula/rolandic operculum, parahippocampal gyrus and inferior frontal gyrus bilaterally. Some of these areas truly reflect ES processing, whereas others are related to design choices, e.g., type of task, type of control condition, type of stimulus. In study 2 we report on 7 neurosurgical patients with lesions involving the areas which were found to be activated by the ALE meta-analysis. We tested their ES recognition abilities and found an impairment of ES recognition. These results indicate that deficits of ES recognition do not exclusively reflect lesions to the right or to the left hemisphere but both hemispheres are involved. The most frequently lesioned area is the hippocampus/insula/STG. We made sure that any impairment in ES recognition would not be related to language problems, but reflect impaired ES processing. In study 3 we carried out an fMRI study on patients (vs. healthy controls) to investigate how the areas involved in ES might be functionally deregulated because of a lesion. The fMRI evidenced that controls activated the right IFG, the STG bilaterally and the left insula. We applied a multimodal mapping approach and found that, although the meta-analysis showed that part of the left and right STG/MTG activation during ES processing might in part be related to design choices, this area was one of the most frequently lesioned areas in our patients, thus highlighting its causal role in ES processing. We found that the ROIs we drew on the two clusters of activation found in the left and in the right STG overlapped with the lesions of at least 4 out of the 7 patients' lesions, indicating that the lack of STG activation found for patients is related to brain damage and is crucial for explaining the ES deficit. PMID:26539096

Two distinct cellular proteins interact with the EIa-responsive element of an adenovirus early promoter.

PubMed Central

Jansen-Durr, P; Wintzerith, M; Reimund, B; Hauss, C; Kédinger, C

1990-01-01

EIa-dependent transactivation of the adenovirus EIIa early (EIIaE) promoter is correlated with the activation of the cellular transcription factor E2F. In this study we identified a cellular protein, C alpha, that is distinct from E2F and that binds two sites in the EIIaE promoter, one of which overlaps with the proximal E2F binding site of the EIIaE promoter. The possible involvement of C alpha in the EIa responsiveness of this promoter is discussed. Images PMID:2139142

Deregulation of E2-EPF ubiquitin carrier protein in papillary renal cell carcinoma.

PubMed

Roos, Frederik C; Evans, Andrew J; Brenner, Walburgis; Wondergem, Bill; Klomp, Jeffery; Heir, Pardeep; Roche, Olga; Thomas, Christian; Schimmel, Heiko; Furge, Kyle A; Teh, Bin T; Thüroff, Joachim W; Hampel, Christian; Ohh, Michael

2011-02-01

Molecular pathways associated with pathogenesis of sporadic papillary renal cell carcinoma (PRCC), the second most common form of kidney cancer, are poorly understood. We analyzed primary tumor specimens from 35 PRCC patients treated by nephrectomy via gene expression analysis and tissue microarrays constructed from an additional 57 paraffin-embedded PRCC samples via immunohistochemistry. Gene products were validated and further studied by Western blot analyses using primary PRCC tumor samples and established renal cell carcinoma cell lines, and potential associations with pathologic variables and survival in 27 patients with follow-up information were determined. We show that the expression of E2-EPF ubiquitin carrier protein, which targets the principal negative regulator of hypoxia-inducible factor (HIF), von Hippel-Lindau protein, for proteasome-dependent degradation, is markedly elevated in the majority of PRCC tumors exhibiting increased HIF1α expression, and is associated with poor prognosis. In addition, we identified multiple hypoxia-responsive elements within the E2-EPF promoter, and for the first time we demonstrated that E2-EPF is a hypoxia-inducible gene directly regulated via HIF1. These findings reveal deregulation of the oxygen-sensing pathway impinging on the positive feedback mechanism of HIF1-mediated regulation of E2-EPF in PRCC. Copyright © 2011 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Quantifying the activity of adenoviral E1A CR2 deletion mutants using renilla luciferase bioluminescence and 3'-deoxy-3'-[18F]fluorothymidine positron emission tomography imaging.

PubMed

Leyton, Julius; Lockley, Michelle; Aerts, Joeri L; Baird, Sarah K; Aboagye, Eric O; Lemoine, Nicholas R; McNeish, Iain A

2006-09-15

The adenoviral E1A CR2 mutant dl922-947 has potent activity in ovarian cancer. We have used Renilla luciferase bioluminescence imaging to monitor viral E1A expression and replication and [18F]fluorothymidine positron emission tomography ([18F]FLT-PET) to quantify the activity of dl922-947 in vivo. We created dlCR2 Ren, with the same E1A CR2 deletion as dl922-947 and the luciferase gene from Renilla reniformis downstream of E1. Light emitted from s.c. and i.p. IGROV1 ovarian carcinoma xenografts was measured following treatment with dlCR2 Ren. Mice bearing s.c. IGROV1 xenografts were injected with 2.96 to 3.7 MBq of [18F]FLT 48 and 168 hours following i.t. injection of dl922-947 or control virus Ad LM-X. The presence of Renilla luciferase in dlCR2 Ren did not reduce in vitro nor in vivo potency compared with dl922-947. Light emission correlated closely with E1A expression in vitro and peaked 48 hours after dlCR2 Ren injection in both s.c. and i.p. IGROV1 xenografts. It diminished by 168 hours in s.c. tumors but persisted for at least 2 weeks in i.p. models. Normalized tumor [18F]FLT uptake at 60 minutes (NUV60), fractional retention, and area under radioactivity curve all decreased marginally 48 hours after dl922-947 treatment and significantly at 168 hours compared with controls. There was a close linear correlation between NUV60 and both tumor proliferation (Ki67 labeling index) and thymidine kinase 1 expression. Renilla luciferase bioluminescence and [18F]FLT-PET imaging are capable of quantifying the activity and effectiveness of E1A CR2-deleted adenoviral mutants in ovarian cancer.

E2F mediates induction of the Sp1-controlled promoter of the human DNA polymerase ɛ B-subunit gene POLE2

PubMed Central

Huang, Deqi; Jokela, Maarit; Tuusa, Jussi; Skog, Sven; Poikonen, Kari; Syväoja, Juhani E.

2001-01-01

The B-subunits of replicative DNA polymerases from Archaea to humans belong to the same protein family, suggesting that they share a common fundamental function. We report here the gene structure for the B-subunit of human DNA polymerase ɛ (POLE2), whose expression and transcriptional regulation is typical for replication proteins with some unique features. The 75 bp core promoter region, located within exon 1, contains an Sp1 element that is a critical determinant of promoter activity as shown by the luciferase reporter, electrophoretic mobility shift and DNase I footprinting assays. Two overlapping E2F elements adjacent to the Sp1 element are essential for full promoter activity and serum response. Binding sites for E2F1 and NF-1 reside immediately downstream from the core promoter region. Our results suggest that human POLE2 is regulated by two E2F–pocket protein complexes, one associated with Sp1 and the other with NF-1. So far, only one replicative DNA polymerase B-subunit gene promoter, POLA2 encoding the B-subunit of DNA polymerase α, has been characterized. Mitogenic activation of the POLE2 promoter by an E2F-mediated mechanism resembles that of POLA2, but the regulation of basal promoter activity is different between these two genes. PMID:11433027

Heterogeneity of murine adherent interleukin-2-activated killer cells. Differential effect of prostaglandin E2 and forskolin.

PubMed

Vaillier, D; Daculsi, R; Gualde, N

1995-01-01

We have studied the relationship between cytotoxic activity, size and granularity of murine interleukin-2-activated adherent killer cells issued from spleen cells cultured with high levels of IL-2. The effects of prostaglandin E2 (PGE2) and forskolin upon these cells were assessed. All adherent spleen cells obtained after 5 days of culture were large granular lymphocytes but presented a heterogeneity in size and granularity. After fractionation on a discontinuous-density Percoll gradient, four cellular subpopulations were isolated. Fluorescence-activated cell sorting analysis showed that cells of the lightest fraction (F1) were the largest, while the cells found in the heaviest fraction (F4) were much more granular than the cells collected in the two intermediate fractions (F2 and F3). The serine esterases level was higher in F4 than in unfractionated cells and diminished to about 40% in cells of fractions F2 and F3, which expressed a cytotoxic activity against YAC-1 cells higher than that in unfractionated cells or in F1 or F4, which presented the lowest cytotoxic activity. When AK cells were cultured for 48 h in the presence of either PGE2 or forskolin, which induce an intracellular increase of cAMP, we observed that PGE2 (1 microM) inhibited the cytotoxic activity, but surprisingly forskolin (2 microM) exerted a stimulating effect on the induction of cytotoxic activity. After fractionation on a discontinuous Percoll gradient we observed the same cellular distribution among PGE2 or forskolin-treated or -untreated cells, but PGE2 induced an increase of size and granularity. This effect of PGE2 was more potent on the cells collected in F4. However this variation of granularity was not associated with any variation in the serine esterase level. The cytotoxic activity of PGE2- or forskolin-treated cells did not present any significant variation relative to the control for cells collected in F2 and F3; on the other hand, forskolin-treated cells collected in F4 showed a significantly higher cytotoxicity than did the corresponding untreated or PGE2-treated cells.

ATM-dependent E2F1 accumulation in the nucleolus is an indicator of ribosomal stress in early response to DNA damage

PubMed Central

Jin, Ya-Qiong; An, Guo-Shun; Ni, Ju-Hua; Li, Shu-Yan; Jia, Hong-Ti

2014-01-01

The nucleolus plays a major role in ribosome biogenesis. Most genotoxic agents disrupt nucleolar structure and function, which results in the stabilization/activation of p53, inducing cell cycle arrest or apoptosis. Likewise, transcription factor E2F1 as a DNA damage responsive protein also plays roles in cell cycle arrest, DNA repair, or apoptosis in response to DNA damage through transcriptional response and protein–protein interaction. Furthermore, E2F1 is known to be involved in regulating rRNA transcription. However, how E2F1 displays in coordinating DNA damage and nucleolar stress is unclear. In this study, we demonstrate that ATM-dependent E2F1 accumulation in the nucleolus is a characteristic feature of nucleolar stress in early response to DNA damage. We found that at the early stage of DNA damage, E2F1 accumulation in the nucleolus was an ATM-dependent and a common event in p53-suficient and -deficient cells. Increased nucleolar E2F1 was sequestered by the nucleolar protein p14ARF, which repressed E2F1-dependent rRNA transcription initiation, and was coupled with S phase. Our data indicate that early accumulation of E2F1 in the nucleolus is an indicator for nucleolar stress and a component of ATM pathway, which presumably buffers elevation of E2F1 in the nucleoplasm and coordinates the diversifying mechanisms of E2F1 acts in cell cycle progression and apoptosis in early response to DNA damage. PMID:24675884

ATM-dependent E2F1 accumulation in the nucleolus is an indicator of ribosomal stress in early response to DNA damage.

PubMed

Jin, Ya-Qiong; An, Guo-Shun; Ni, Ju-Hua; Li, Shu-Yan; Jia, Hong-Ti

2014-01-01

The nucleolus plays a major role in ribosome biogenesis. Most genotoxic agents disrupt nucleolar structure and function, which results in the stabilization/activation of p53, inducing cell cycle arrest or apoptosis. Likewise, transcription factor E2F1 as a DNA damage responsive protein also plays roles in cell cycle arrest, DNA repair, or apoptosis in response to DNA damage through transcriptional response and protein-protein interaction. Furthermore, E2F1 is known to be involved in regulating rRNA transcription. However, how E2F1 displays in coordinating DNA damage and nucleolar stress is unclear. In this study, we demonstrate that ATM-dependent E2F1 accumulation in the nucleolus is a characteristic feature of nucleolar stress in early response to DNA damage. We found that at the early stage of DNA damage, E2F1 accumulation in the nucleolus was an ATM-dependent and a common event in p53-suficient and -deficient cells. Increased nucleolar E2F1 was sequestered by the nucleolar protein p14ARF, which repressed E2F1-dependent rRNA transcription initiation, and was coupled with S phase. Our data indicate that early accumulation of E2F1 in the nucleolus is an indicator for nucleolar stress and a component of ATM pathway, which presumably buffers elevation of E2F1 in the nucleoplasm and coordinates the diversifying mechanisms of E2F1 acts in cell cycle progression and apoptosis in early response to DNA damage.

Hydrolysis of acetylthiocoline, o-nitroacetanilide and o-nitrotrifluoroacetanilide by fetal bovine serum acetylcholinesterase.

PubMed

Montenegro, María F; Moral-Naranjo, María T; Muñoz-Delgado, Encarnación; Campoy, Francisco J; Vidal, Cecilio J

2009-04-01

Besides esterase activity, acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) hydrolyze o-nitroacetanilides through aryl acylamidase activity. We have reported that BuChE tetramers and monomers of human blood plasma differ in o-nitroacetanilide (ONA) hydrolysis. The homology in quaternary structure and folding of subunits in the prevalent BuChE species (G4(H)) of human plasma and AChE forms of fetal bovine serum prompted us to study the esterase and amidase activities of fetal bovine serum AChE. The k(cat)/K(m) values for acetylthiocholine (ATCh), ONA and its trifluoro derivative N-(2-nitrophenyl)-trifluoroacetamide (F-ONA) were 398 x 10(6) M(-1) min(-1), 0.8 x 10(6) M(-1) min(-1), and 17.5 x 10(6) M(-1) min(-1), respectively. The lack of inhibition of amidase activity at high F-ONA concentrations makes it unlikely that there is a role for the peripheral anionic site (PAS) in F-ONA degradation, but the inhibition of ATCh, ONA and F-ONA hydrolysis by the PAS ligand fasciculin-2 points to the transit of o-nitroacetalinides near the PAS on their way to the active site. Sedimentation analysis confirmed substrate hydrolysis by tetrameric 10.9S AChE. As compared with esterase activity, amidase activity was less sensitive to guanidine hydrochloride. This reagent led to the formation of 9.3S tetramers with partially unfolded subunits. Their capacity to hydrolyze ATCh and F-ONA revealed that, despite the conformational change, the active site architecture and functionality of AChE were partially retained.

Role of melatonin in the epigenetic regulation of breast cancer.

PubMed

Korkmaz, Ahmet; Sanchez-Barcelo, Emilio J; Tan, Dun-Xian; Reiter, Russel J

2009-05-01

The oncostatic properties of melatonin as they directly or indirectly involve epigenetic mechanisms of cancer are reviewed with a special focus on breast cancer. Five lines of evidence suggest that melatonin works via epigenetic processes: (1) melatonin influences transcriptional activity of nuclear receptors (ERalpha, GR and RAR) involved in the regulation of breast cancer cell growth; (2) melatonin down-regulates the expression of genes responsible for the local synthesis or activation of estrogens including aromatase, an effect which may be mediated by methylation of the CYP19 gene or deacetylation of CYP19 histones; (3) melatonin inhibits telomerase activity and expression induced by either natural estrogens or xenoestrogens; (4) melatonin modulates the cell cycle through the inhibition of cyclin D1 expression; (5) melatonin influences circadian rhythm disturbances dependent on alterations of the light/dark cycle (i.e., light at night) with the subsequent deregulation of PER2 which acts as a tumor suppressor gene.

Comparison of ionospheric F2 peak parameters foF2 and hmF2 with IRI2001 at Hainan

NASA Astrophysics Data System (ADS)

Wang, X.; Shi, J. K.; Wang, G. J.; Gong, Y.

2009-06-01

Monthly median values of foF2, hmF2 and M(3000)F2 parameters, with quarter-hourly time interval resolution for the diurnal variation, obtained with DPS4 digisonde at Hainan (19.5°N, 109.1°E; Geomagnetic coordinates: 178.95°E, 8.1°N) are used to investigate the low-latitude ionospheric variations and comparisons with the International Reference Ionosphere (IRI) model predictions. The data used for the present study covers the period from February 2002 to April 2007, which is characterized by a wide range of solar activity, ranging from high solar activity (2002) to low solar activity (2007). The results show that (1) Generally, IRI predictions follow well the diurnal and seasonal variation patterns of the experimental values of foF2, especially in the summer of 2002. However, there are systematic deviation between experimental values and IRI predictions with either CCIR or URSI coefficients. Generally IRI model greatly underestimate the values of foF2 from about noon to sunrise of next day, especially in the afternoon, and slightly overestimate them from sunrise to about noon. It seems that there are bigger deviations between IRI Model predictions and the experimental observations for the moderate solar activity. (2) Generally the IRI-predicted hmF2 values using CCIR M(3000)F2 option shows a poor agreement with the experimental results, but there is a relatively good agreement in summer at low solar activity. The deviation between the IRI-predicted hmF2 using CCIR M(3000)F2 and observed hmF2 is bigger from noon to sunset and around sunrise especially at high solar activity. The occurrence time of hmF2 peak (about 1200 LT) of the IRI model predictions is earlier than that of observations (around 1500 LT). The agreement between the IRI hmF2 obtained with the measured M(3000)F2 and the observed hmF2 is very good except that IRI overestimates slightly hmF2 in the daytime in summer at high solar activity and underestimates it in the nighttime with lower values near sunrise at low solar activity.

Activation of RNA Polymerase III Transcription in Cells Transformed by Simian Virus 40

PubMed Central

Larminie, Christopher G. C.; Sutcliffe, Josephine E.; Tosh, Kerrie; Winter, Andrew G.; Felton-Edkins, Zoe A.; White, Robert J.

1999-01-01

RNA polymerase (Pol) III transcription is abnormally active in fibroblasts that have been transformed by simian virus 40 (SV40). This report presents evidence that two separate components of the general Pol III transcription apparatus, TFIIIB and TFIIIC2, are deregulated following SV40 transformation. TFIIIC2 subunits are expressed at abnormally high levels in SV40-transformed cells, an effect which is observed at both protein and mRNA levels. In untransformed fibroblasts, TFIIIB is subject to repression through association with the retinoblastoma protein RB. The interaction between RB and TFIIIB is compromised following SV40 transformation. Furthermore, the large T antigen of SV40 is shown to relieve repression by RB. The E7 oncoprotein of human papillomavirus can also activate Pol III transcription, an effect that is dependent on its ability to bind to RB. The data provide evidence that both TFIIIB and TFIIIC2 are targets for activation by DNA tumor viruses. PMID:10373542

Cranberry extract inhibits in vitro adhesion of F4 and F18+Escherichia coli to pig intestinal epithelium and reduces in vivo excretion of pigs orally challenged with F18+ verotoxigenic E. coli.

PubMed

Coddens, Annelies; Loos, Michaela; Vanrompay, Daisy; Remon, Jean Paul; Cox, Eric

2017-04-01

F4 + E. coli and F18 + E. coli infections are an important threat for pig industry worldwide. Antibiotics are commonly used to treat infected piglets, but the emerging development of resistance against antibiotics raises major concerns. Hence, alternative therapies to prevent pigs from F4 + E. coli and F18 + E. coli infections need to be developed. Since cranberry previously showed anti-adhesive activity against uropathogenic E. coli, we aimed to investigate whether cranberry extract could also inhibit binding of F4 + E. coli and F18 + E. coli to pig intestinal epithelium. Using the in vitro villus adhesion assay, we found that low concentrations of cranberry extract (20μg or 100μg/ml) have strong inhibitory activity on F4 + E. coli (75.3%, S.D.=9.31 or 95.8%, S.D.=2.56, respectively) and F18 + E. coli adherence (100% inhibition). This effect was not due to antimicrobial activity. Moreover, cranberry extract (10mg or 100mg) could also abolish in vivo binding of F4 and F18 fimbriae to the pig intestinal epithelium in ligated loop experiments. Finally, two challenge experiments with F18 + E. coli were performed to address the efficacy of in-feed or water supplemented cranberry extract. No effect could be observed in piglets that received cranberry extract only in feed (1g/kg or 10g/kg). However, supplementation of feed (10g/kg) and drinking water (1g/L) significantly decreased excretion and diarrhea. The decreased infection resulted in a decreased serum antibody response indicating reduced exposure to F18 + E. coli. Copyright © 2017 Elsevier B.V. All rights reserved.

The association between perceived emotional support, maternal mood, salivary cortisol, salivary cortisone, and the ratio between the two compounds in response to acute stress in second trimester pregnant women.

PubMed

La Marca-Ghaemmaghami, Pearl; La Marca, Roberto; Dainese, Sara M; Haller, Marina; Zimmermann, Roland; Ehlert, Ulrike

2013-10-01

Little is known about the effect of social support on the reactivity of the hypothalamic-pituitary-adrenal (HPA) axis during pregnancy. Moreover, when investigating the HPA axis most studies do not consider the activity of 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2), an enzyme within the salivary glands that inactivates cortisol to cortisone. This study explores the association between perceived emotional support and the maternal psychobiological stress response to a standardized naturalistic stressor by assessing maternal mood and the reactivity of salivary cortisol (SalF), salivary cortisone (SalE), and the SalE/(E+F) ratio as a marker of 11β-HSD2 activity. Repeated saliva samples and measures of maternal mood were obtained from 34 healthy second trimester pregnant women undergoing amniocentesis which served as a psychological stressor. The pregnant women additionally responded to a questionnaire of perceived emotional support and provided sociodemographic (e.g., maternal educational degree) and pregnancy-specific data (e.g., planned versus unplanned pregnancy). Perceived emotional support neither showed a significant effect on mood nor on the SalF or SalE response to stress. However, a moderately strong positive association was found between perceived emotional support and SalE/(E+F) (r=.49). Additionally, the final regression analysis revealed a significant negative relationship between educational degree, planned/unplanned pregnancy and SalE/(E+F). Findings suggest a higher metabolization of cortisol to cortisone in pregnant women with higher emotional support. In contrast, higher maternal education and unplanned pregnancy appear to be associated with decreased salivary 11β-HSD2 activity. The current study emphasizes the importance of taking the activity of 11β-HSD2 into account when examining SalF. © 2013.

Spread-F occurrences and relationships with foF2 and h'F at low- and mid-latitudes in China

NASA Astrophysics Data System (ADS)

Wang, Ning; Guo, Lixin; Zhao, Zhenwei; Ding, Zonghua; Lin, Leke

2018-04-01

Ionospheric irregularities are an important phenomenon in scientific studies and applications of radio-wave propagation. Spread-F echoes in ionograms are a type of high-frequency band irregularities that include frequency spread-F (FSF), range spread-F (RSF), and mixed spread-F (MSF) events. In this study, we obtained spread-F data from four ionosondes at low- and mid-latitudes near the 120°E chain in China during the 23rd solar cycle. We used these data to investigate spread-F occurrence percentages and variations with local time, season, latitude, and solar activity. The four ionosondes were located at Haikou (HK) (20°N, 110.34°E), Guangzhou (GZ) (23.14°N, 113.36°E), Beijing (BJ) (40.11°N, 116.28°E), and Changchun (CC) (43.84°N, 125.28°E). We also present possible correlations between spread-Fs and other ionospheric parameters, such as the critical frequency of the F2-layer (foF2) and the virtual height of the bottom-side F-layer (h'F). In particular, we investigated the possible threshold of the foF2 affecting the FSF and the relationship between the h'F and the RSF. The main conclusions are as follows: (a) the FSF occurrence percentages were anti-correlated with solar activity at all four sites; meanwhile, RSF occurrence rates increased with the increase in solar activity at HK, but not at the other three sites; (b) FSF occurrence rates were larger at the mid-latitudes than expected, while FSFs occurred more often after midnight; (c) the highest FSF occurrence rates mostly appeared during the summer months, while RSFs occurred mostly in the equinoctial months of 2000-2002 at HK and GZ; (d) a lower foF2 was suitable for FSF events; nevertheless, h'F and RSF occurrences satisfied the parabolic relationship; (e) the foF2 thresholds for FSFs were 15, 14, 7.6, and 7.8 MHz at HK, GZ, BJ, and CC, respectively. The h'Fs occurring between 240 and 290 km were more favorable for RSF occurrences. These results are important for understanding ionospheric irregularity variations in eastern Asia and for improving space weather modeling and forecasting capabilities[Figure not available: see fulltext.] .

Modulation of Estrogen Response Element-Driven Gene Expressions and Cellular Proliferation with Polar Directions by Designer Transcription Regulators

PubMed Central

Muyan, Mesut; Güpür, Gizem; Yaşar, Pelin; Ayaz, Gamze; User, Sırma Damla; Kazan, Hasan Hüseyin; Huang, Yanfang

2015-01-01

Estrogen receptor α (ERα), as a ligand-dependent transcription factor, mediates 17β-estradiol (E2) effects. ERα is a modular protein containing a DNA binding domain (DBD) and transcription activation domains (AD) located at the amino- and carboxyl-termini. The interaction of the E2-activated ERα dimer with estrogen response elements (EREs) of genes constitutes the initial step in the ERE-dependent signaling pathway necessary for alterations of cellular features. We previously constructed monomeric transcription activators, or monotransactivators, assembled from an engineered ERE-binding module (EBM) using the ERα-DBD and constitutively active ADs from other transcription factors. Monotransactivators modulated cell proliferation by activating and repressing ERE-driven gene expressions that simulate responses observed with E2-ERα. We reasoned here that integration of potent heterologous repression domains (RDs) into EBM could generate monotransrepressors that alter ERE-bearing gene expressions and cellular proliferation in directions opposite to those observed with E2-ERα or monotransactivators. Consistent with this, monotransrepressors suppressed reporter gene expressions that emulate the ERE-dependent signaling pathway. Moreover, a model monotransrepressor regulated DNA synthesis, cell cycle progression and proliferation of recombinant adenovirus infected ER-negative cells through decreasing as well as increasing gene expressions with polar directions compared with E2-ERα or monotransactivator. Our results indicate that an ‘activator’ or a ‘repressor’ possesses both transcription activating/enhancing and repressing/decreasing abilities within a chromatin context. Offering a protein engineering platform to alter signal pathway-specific gene expressions and cell growth, our approach could also be used for the development of tools for epigenetic modifications and for clinical interventions wherein multigenic de-regulations are an issue. PMID:26295471

77 FR 74487 - Agency Information Collection Activities: Petition for Alien Fiance(e), Form Number I-129F...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-14

...-0001] Agency Information Collection Activities: Petition for Alien Fiance(e), Form Number I-129F... information collection. (2) Title of the Form/Collection: Petition for Alien Fiance(e). (3) Agency form number... petition for an alien fiance(e), spouse, or his/her children. (5) An estimate of the total number of...

Stereocontrolled generation of nucleophilic (Z)- or (E)-α-fluoroalkenylchromium reagents via carbon-fluorine bond activation: highly stereoselective synthesis of (E)- or (Z)-β-fluoroallylic alcohols.

PubMed

Nihei, Takashi; Yokotani, Saya; Ishihara, Takashi; Konno, Tsutomu

2014-02-14

Highly nucleophilic (Z)- or (E)-α-fluoroalkenylchromium species could be generated in a stereoselective manner via C-F bond activation of CBrF2-containing molecules, and they reacted smoothly with various aldehydes to give (E)- or (Z)-β-fluoroallylic alcohol derivatives in high yields, respectively.

Fire Incident Reporting Manual

DTIC Science & Technology

1984-02-01

Purpose 1-1 B. Scope 1-1 C. Procedures 1-1 D. Exclusions 1-3 E . Preparation 1-3 F. Information Requirements 1-4 CHAPTER 2 - INSTRUCTIONS FOR PREPARING DoD...Structure and Fire Data 2-16 4. Section D - Fire Protection Facilities (In Structures Only) 2-28 5. Section E - Losses 2-30 6. Section F - Times (24...Activities Program," February 21, 1976 ( e ) National Fire Protection Association (NFPA) Standard 901, "Uniform Coding for Fire Protection," 1976 (f) NFPA

Biological Effects of Activating Distinct ErbB Receptor Dimers in Polarized Growth Arrested Epithelia

DTIC Science & Technology

2006-09-01

deregulating the function of Par protein complex, we made the unexpected observation that overexpression of Par6 induced growth- factor independent...predisposition factors for human cancer [8] and the human papillomavirus protein E6, targets scribble for degradation[9]. It has also been shown that Par6...vivo and thus is an excellent model to study the important factors in the initiation of the oncogenic process. However, activation of ErbB1 does not

Functional interaction of CCAAT/enhancer-binding-protein-α basic region mutants with E2F transcription factors and DNA.

PubMed

Kowenz-Leutz, Elisabeth; Schuetz, Anja; Liu, Qingbin; Knoblich, Maria; Heinemann, Udo; Leutz, Achim

2016-07-01

The transcription factor CCAAT/enhancer-binding protein α (C/EBPα) regulates cell cycle arrest and terminal differentiation of neutrophils and adipocytes. Mutations in the basic leucine zipper domain (bZip) of C/EBPα are associated with acute myeloid leukemia. A widely used murine transforming C/EBPα basic region mutant (BRM2) entails two bZip point mutations (I294A/R297A). BRM2 has been discordantly described as defective for DNA binding or defective for interaction with E2F. We have separated the two BRM2 mutations to shed light on the intertwined reciprocity between C/EBPα-E2F-DNA interactions. Both, C/EBPα I294A and R297A retain transactivation capacity and interaction with E2F-DP. The C/EBPα R297A mutation destabilized DNA binding, whereas the C/EBPα I294A mutation enhanced binding to DNA. The C/EBPα R297A mutant, like BRM2, displayed enhanced interaction with E2F-DP but failed to repress E2F-dependent transactivation although both mutants were readily suppressed by E2F1 for transcription through C/EBP cis-regulatory sites. In contrast, the DNA binding enhanced C/EBPα I294A mutant displayed increased repression of E2F-DP mediated transactivation and resisted E2F-DP mediated repression. Thus, the efficient repression of E2F dependent S-phase genes and the activation of differentiation genes reside in the balanced DNA binding capacity of C/EBPα. Copyright © 2016 Elsevier B.V. All rights reserved.

The HDAC inhibitor SAHA regulates CBX2 stability via a SUMO-triggered ubiquitin-mediated pathway in leukemia.

PubMed

Di Costanzo, Antonella; Del Gaudio, Nunzio; Conte, Lidio; Dell'Aversana, Carmela; Vermeulen, Michiel; de Thé, Hugues; Migliaccio, Antimo; Nebbioso, Angela; Altucci, Lucia

2018-05-01

Polycomb group (PcG) proteins regulate transcription, playing a key role in stemness and differentiation. Deregulation of PcG members is known to be involved in cancer pathogenesis. Emerging evidence suggests that CBX2, a member of the PcG protein family, is overexpressed in several human tumors, correlating with lower overall survival. Unraveling the mechanisms regulating CBX2 expression may thus provide a promising new target for anticancer strategies. Here we show that the HDAC inhibitor SAHA regulates CBX2 stability via a SUMO-triggered ubiquitin-mediated pathway in leukemia. We identify CBX4 and RNF4 as the E3 SUMO and E3 ubiquitin ligase, respectively, and describe the specific molecular mechanism regulating CBX2 protein stability. Finally, we show that CBX2-depleted leukemic cells display impaired proliferation, underscoring its critical role in regulating leukemia cell tumorogenicity. Our results show that SAHA affects CBX2 stability, revealing a potential SAHA-mediated anti-leukemic activity though SUMO2/3 pathway.

Genetic enhancement of microsomal epoxide hydrolase improves metabolic detoxification but impairs cerebral blood flow regulation.

PubMed

Marowsky, Anne; Haenel, Karen; Bockamp, Ernesto; Heck, Rosario; Rutishauser, Sibylle; Mule, Nandkishor; Kindler, Diana; Rudin, Markus; Arand, Michael

2016-12-01

Microsomal epoxide hydrolase (mEH) is a detoxifying enzyme for xenobiotic compounds. Enzymatic activity of mEH can be greatly increased by a point mutation, leading to an E404D amino acid exchange in its catalytic triad. Surprisingly, this variant is not found in any vertebrate species, despite the obvious advantage of accelerated detoxification. We hypothesized that this evolutionary avoidance is due to the fact that the mEH plays a dualistic role in detoxification and control of endogenous vascular signaling molecules. To test this, we generated mEH E404D mice and assessed them for detoxification capacity and vascular dynamics. In liver microsomes from these mice, turnover of the xenobiotic compound phenanthrene-9,10-oxide was four times faster compared to WT liver microsomes, confirming accelerated detoxification. mEH E404D animals also showed faster metabolization of a specific class of endogenous eicosanoids, arachidonic acid-derived epoxyeicosatrienoic acids (EETs) to dihydroxyeicosatrienoic acids (DHETs). Significantly higher DHETs/EETs ratios were found in mEH E404D liver, urine, plasma, brain and cerebral endothelial cells compared to WT controls, suggesting a broad impact of the mEH mutant on endogenous EETs metabolism. Because EETs are strong vasodilators in cerebral vasculature, hemodynamics were assessed in mEH E404D and WT cerebral cortex and hippocampus using cerebral blood volume (CBV)-based functional magnetic resonance imaging (fMRI). Basal CBV 0 levels were similar between mEH E404D and control mice in both brain areas. But vascular reactivity and vasodilation in response to the vasodilatory drug acetazolamide were reduced in mEH E404D forebrain compared to WT controls by factor 3 and 2.6, respectively. These results demonstrate a critical role for mEH E404D in vasodynamics and suggest that deregulation of endogenous signaling pathways is the undesirable gain of function associated with the E404D variant.

Differentiation and injury-repair signals modulate the interaction of E2F and pRB proteins with novel target genes in keratinocytes.

PubMed

Chang, Wing Y; Andrews, Joseph; Carter, David E; Dagnino, Lina

2006-08-01

E2F transcription factors are central to epidermal morphogenesis and regeneration after injury. The precise nature of E2F target genes involved in epidermal formation and repair has yet to be determined. Identification of these genes is essential to understand how E2F proteins regulate fundamental aspects of epidermal homeostasis and transformation. We have conducted a genome-wide screen using CpG island microarray analysis to identify novel promoters bound by E2F3 and E2F5 in human keratinocytes. We further characterized several of these genes, and determined that multiple E2F and retinoblastoma (pRb) family proteins associate with them in exponentially proliferating cells. We also assessed the effect on E2F and pRb binding to those genes in response to differentiation induced by bone morphogenetic protein-6 (BMP-6), or to activation of repair mechanisms induced by transforming growth factor-beta (TGF-beta). These studies demonstrate promoter- and cytokine-specific changes in binding profiles of E2F and/or pRb family proteins. For example, E2F1, 3, 4 and p107 were recruited to the N-myc promoter in cells treated with BMP-6, whereas E2F1, 3, 4, 5, p107 and p130 were bound to this promoter in the presence of TGF-beta. Functionally, these different interactions resulted in transcriptional repression by BMP-6 and TGF-beta of the N-myc gene, via mechanisms that involved E2F binding to the promoter and association with pRb-family proteins. Thus, multiple combinations of E2F and pRb family proteins may associate with and transcriptionally regulate a given target promoter in response to differentiation and injury-repair stimuli in epidermal keratinocytes.

Synergy between the KEAP1/NRF2 and PI3K Pathways Drives Non-Small-Cell Lung Cancer with an Altered Immune Microenvironment.

PubMed

Best, Sarah A; De Souza, David P; Kersbergen, Ariena; Policheni, Antonia N; Dayalan, Saravanan; Tull, Dedreia; Rathi, Vivek; Gray, Daniel H; Ritchie, Matthew E; McConville, Malcolm J; Sutherland, Kate D

2018-04-03

The lung presents a highly oxidative environment, which is tolerated through engagement of tightly controlled stress response pathways. A critical stress response mediator is the transcription factor nuclear factor erythroid-2-related factor 2 (NFE2L2/NRF2), which is negatively regulated by Kelch-like ECH-associated protein 1 (KEAP1). Alterations in the KEAP1/NRF2 pathway have been identified in 23% of lung adenocarcinomas, suggesting that deregulation of the pathway is a major cancer driver. We demonstrate that inactivation of Keap1 and Pten in the mouse lung promotes adenocarcinoma formation. Notably, metabolites identified in the plasma of Keap1 f/f /Pten f/f tumor-bearing mice indicate that tumorigenesis is associated with reprogramming of the pentose phosphate pathway. Furthermore, the immune milieu was dramatically changed by Keap1 and Pten deletion, and tumor regression was achieved utilizing immune checkpoint inhibition. Thus, our study highlights the ability to exploit both metabolic and immune characteristics in the detection and treatment of lung tumors harboring KEAP1/NRF2 pathway alterations. Copyright © 2018 Elsevier Inc. All rights reserved.

Cytoplasmic E2f4 forms organizing centres for initiation of centriole amplification during multiciliogenesis

PubMed Central

Mori, Munemasa; Hazan, Renin; Danielian, Paul S.; Mahoney, John E.; Li, Huijun; Lu, Jining; Miller, Emily S.; Zhu, Xueliang; Lees, Jacqueline A.; Cardoso, Wellington V.

2017-01-01

Abnormal development of multiciliated cells is a hallmark of a variety of human conditions associated with chronic airway diseases, hydrocephalus and infertility. Multiciliogenesis requires both activation of a specialized transcriptional program and assembly of cytoplasmic structures for large-scale centriole amplification that generates basal bodies. It remains unclear, however, what mechanism initiates formation of these multiprotein complexes in epithelial progenitors. Here we show that this is triggered by nucleocytoplasmic translocation of the transcription factor E2f4. After inducing a transcriptional program of centriole biogenesis, E2f4 forms apical cytoplasmic organizing centres for assembly and nucleation of deuterosomes. Using genetically altered mice and E2F4 mutant proteins we demonstrate that centriole amplification is crucially dependent on these organizing centres and that, without cytoplasmic E2f4, deuterosomes are not assembled, halting multiciliogenesis. Thus, E2f4 integrates nuclear and previously unsuspected cytoplasmic events of centriole amplification, providing new perspectives for the understanding of normal ciliogenesis, ciliopathies and cancer. PMID:28675157

dREAM co-operates with insulator-binding proteins and regulates expression at divergently paired genes

PubMed Central

Korenjak, Michael; Kwon, Eunjeong; Morris, Robert T.; Anderssen, Endre; Amzallag, Arnaud; Ramaswamy, Sridhar; Dyson, Nicholas J.

2014-01-01

dREAM complexes represent the predominant form of E2F/RBF repressor complexes in Drosophila. dREAM associates with thousands of sites in the fly genome but its mechanism of action is unknown. To understand the genomic context in which dREAM acts we examined the distribution and localization of Drosophila E2F and dREAM proteins. Here we report a striking and unexpected overlap between dE2F2/dREAM sites and binding sites for the insulator-binding proteins CP190 and Beaf-32. Genetic assays show that these components functionally co-operate and chromatin immunoprecipitation experiments on mutant animals demonstrate that dE2F2 is important for association of CP190 with chromatin. dE2F2/dREAM binding sites are enriched at divergently transcribed genes, and the majority of genes upregulated by dE2F2 depletion represent the repressed half of a differentially expressed, divergently transcribed pair of genes. Analysis of mutant animals confirms that dREAM and CP190 are similarly required for transcriptional integrity at these gene pairs and suggest that dREAM functions in concert with CP190 to establish boundaries between repressed/activated genes. Consistent with the idea that dREAM co-operates with insulator-binding proteins, genomic regions bound by dREAM possess enhancer-blocking activity that depends on multiple dREAM components. These findings suggest that dREAM functions in the organization of transcriptional domains. PMID:25053843

Ectopic expression of homeobox gene NKX2-1 in diffuse large B-cell lymphoma is mediated by aberrant chromatin modifications.

PubMed

Nagel, Stefan; Ehrentraut, Stefan; Tomasch, Jürgen; Quentmeier, Hilmar; Meyer, Corinna; Kaufmann, Maren; Drexler, Hans G; MacLeod, Roderick A F

2013-01-01

Homeobox genes encode transcription factors ubiquitously involved in basic developmental processes, deregulation of which promotes cell transformation in multiple cancers including hematopoietic malignancies. In particular, NKL-family homeobox genes TLX1, TLX3 and NKX2-5 are ectopically activated by chromosomal rearrangements in T-cell neoplasias. Here, using transcriptional microarray profiling and RQ-PCR we identified ectopic expression of NKL-family member NKX2-1, in a diffuse large B-cell lymphoma (DLBCL) cell line SU-DHL-5. Moreover, in silico analysis demonstrated NKX2-1 overexpression in 5% of examined DLBCL patient samples. NKX2-1 is physiologically expressed in lung and thyroid tissues where it regulates differentiation. Chromosomal and genomic analyses excluded rearrangements at the NKX2-1 locus in SU-DHL-5, implying alternative activation. Comparative expression profiling implicated several candidate genes in NKX2-1 regulation, variously encoding transcription factors, chromatin modifiers and signaling components. Accordingly, siRNA-mediated knockdown and overexpression studies confirmed involvement of transcription factor HEY1, histone methyltransferase MLL and ubiquitinated histone H2B in NKX2-1 deregulation. Chromosomal aberrations targeting MLL at 11q23 and the histone gene cluster HIST1 at 6p22 which we observed in SU-DHL-5 may, therefore, represent fundamental mutations mediating an aberrant chromatin structure at NKX2-1. Taken together, we identified ectopic expression of NKX2-1 in DLBCL cells, representing the central player in an oncogenic regulative network compromising B-cell differentiation. Thus, our data extend the paradigm of NKL homeobox gene deregulation in lymphoid malignancies.

Direct trans-activation of the human cyclin D2 gene by the oncogene product Tax of human T-cell leukemia virus type I.

PubMed

Huang, Y; Ohtani, K; Iwanaga, R; Matsumura, Y; Nakamura, M

2001-03-01

Cyclins are one of the pivotal determinants regulating cell cycle progression. We previously reported that the trans-activator Tax of human T-cell leukemia virus type I (HTLV-I) induces endogenous cyclin D2 expression along with cell cycle progression in a resting human T-cell line, Kit 225, suggesting a role of cyclin D2 in Tax-mediated cell cycle progression. The cyclin D2 gene has a typical E2F binding element, raising the possibility that induction of cyclin D2 expression is a consequence of cell cycle progression. In this study, we examined the role and molecular mechanism of induction of the endogenous human cyclin D2 gene by Tax. Introduction of p19(INK4d), a cyclin dependent kinase (CDK) inhibitor of the INK4 family specific for D-type CDK, inhibited Tax-mediated activation of E2F, indicating requirement of D-type CDK in Tax-mediated activation of E2F. Previously indicated E2F binding element and two NF-kappaB-like binding elements in the 1.6 kbp cyclin D2 promoter fragment had little, if any, effect on responsiveness to Tax. We found that trans-activation of the cyclin D2 promoter by Tax was mainly mediated by a newly identified NF-kappaB-like element with auxiliary contribution of a CRE-like element residing in sequences downstream of -444 which were by themselves sufficient for trans-activation by Tax. These results indicate that Tax directly trans-activates the cyclin D2 gene, resulting in growth promotion and perhaps leukemogenesis through activation of D-type CDK.

Single Electron Delivery to Lewis Pairs: An Avenue to Anions by Small Molecule Activation.

PubMed

Liu, Liu Leo; Cao, Levy L; Shao, Yue; Stephan, Douglas W

2017-07-26

Single electron transfer (SET) reactions are effected by the combination of a Lewis acid (e.g., E(C 6 F 5 ) 3 E = B or Al) with a small molecule substrate and decamethylferrocene (Cp* 2 Fe). Initially, the corresponding reactions of (PhS) 2 and (PhTe) 2 were shown to give the species [Cp* 2 Fe][PhSB(C 6 F 5 ) 3 ] 1 and [Cp* 2 Fe][(μ-PhS)(Al(C 6 F 5 ) 3 ) 2 ] 2 and [Cp* 2 Fe][(μ-PhTe)(Al(C 6 F 5 ) 3 ) 2 ] 3, respectively. Analogous reactions with di-tert-butyl peroxide yielded [Cp* 2 Fe][(μ-HO)(B(C 6 F 5 ) 3 ) 2 ] 4 with isobutene while with benzoyl peroxide afforded [Cp* 2 Fe][PhC(O)OE(C 6 F 5 ) 3 ] (E = B 5, Al 6). Evidence for a radical pathway was provided by the reaction of Ph 3 SnH and p-quinone afforded [Cp* 2 Fe][HB(C 6 F 5 ) 3 ] 7 and [Cp* 2 Fe] 2 [(μ-O 2 C 6 H 4 )(E(C 6 F 5 ) 3 ) 2 ] (E = B 8, Al 9). In addition, the reaction of TEMPO with Lewis acid and Cp* 2 Fe afforded [Cp* 2 Fe][(C 5 H 6 Me 4 NOE(C 6 F 5 ) 3 ] (E = B 10, Al 11). Finally, reactions with O 2 , Se, Te and S 8 gave [Cp* 2 Fe] 2 [((C 6 F 5 ) 2 Al(μ-O)Al(C 6 F 5 ) 3 ) 2 ] 2 12, [Cp* 2 Fe] 2 [((C 6 F 5 ) 2 Al(μ-Se)Al(C 6 F 5 ) 3 ) 2 ] 2 13, [Cp* 2 Fe][(μ-Te) 2 (Al(C 6 F 5 ) 2 ) 3 ] 14 and [Cp* 2 Fe] 2 [(μ-S 7 )B(C 6 F 5 ) 3 ) 2 ] 15, respectively. The mechanisms of these SET reactions are discussed, and the ramifications are considered.

Mutational signatures reveal the role of RAD52 in p53-independent p21-driven genomic instability.

PubMed

Galanos, Panagiotis; Pappas, George; Polyzos, Alexander; Kotsinas, Athanassios; Svolaki, Ioanna; Giakoumakis, Nickolaos N; Glytsou, Christina; Pateras, Ioannis S; Swain, Umakanta; Souliotis, Vassilis L; Georgakilas, Alexandros G; Geacintov, Nicholas; Scorrano, Luca; Lukas, Claudia; Lukas, Jiri; Livneh, Zvi; Lygerou, Zoi; Chowdhury, Dipanjan; Sørensen, Claus Storgaard; Bartek, Jiri; Gorgoulis, Vassilis G

2018-03-16

Genomic instability promotes evolution and heterogeneity of tumors. Unraveling its mechanistic basis is essential for the design of appropriate therapeutic strategies. In a previous study, we reported an unexpected oncogenic property of p21 WAF1/Cip1 , showing that its chronic expression in a p53-deficient environment causes genomic instability by deregulation of the replication licensing machinery. We now demonstrate that p21 WAF1/Cip1 can further fuel genomic instability by suppressing the repair capacity of low- and high-fidelity pathways that deal with nucleotide abnormalities. Consequently, fewer single nucleotide substitutions (SNSs) occur, while formation of highly deleterious DNA double-strand breaks (DSBs) is enhanced, crafting a characteristic mutational signature landscape. Guided by the mutational signatures formed, we find that the DSBs are repaired by Rad52-dependent break-induced replication (BIR) and single-strand annealing (SSA) repair pathways. Conversely, the error-free synthesis-dependent strand annealing (SDSA) repair route is deficient. Surprisingly, Rad52 is activated transcriptionally in an E2F1-dependent manner, rather than post-translationally as is common for DNA repair factor activation. Our results signify the importance of mutational signatures as guides to disclose the repair history leading to genomic instability. We unveil how chronic p21 WAF1/Cip1 expression rewires the repair process and identifies Rad52 as a source of genomic instability and a candidate therapeutic target.

The MAPK1/3 pathway is essential for the deregulation of autophagy observed in G2019S LRRK2 mutant fibroblasts

PubMed Central

Bravo-San Pedro, José M.; Gómez-Sánchez, Rubén; Niso-Santano, Mireia; Pizarro-Estrella, Elisa; Aiastui-Pujana, Ana; Gorostidi, Ana; Climent, Vicente; López de Maturana, Rakel; Sanchez-Pernaute, Rosario; López de Munain, Adolfo; Fuentes, José M.; González-Polo, Rosa A.

2012-01-01

The link between the deregulation of autophagy and cell death processes can be essential in the development of several neurodegenerative diseases, such as Parkinson disease (PD). However, the molecular mechanism of deregulation of this degradative process in PD patients is unknown. The leucine-rich repeat kinase 2 (LRRK2) gene is related to PD and its implication in autophagy regulation has been described. Our recent work shows that the presence of the G2019S LRRK2 mutation, one of the most prevalent in LRRK2, is accompanied by a deregulation of autophagy basal levels dependent on the MAPK1/3 (ERK2/1) pathway. PMID:22914360

Cell cycle regulator E2F4 is essential for the development of the ventral telencephalon.

PubMed

Ruzhynsky, Vladimir A; McClellan, Kelly A; Vanderluit, Jacqueline L; Jeong, Yongsu; Furimsky, Marosh; Park, David S; Epstein, Douglas J; Wallace, Valerie A; Slack, Ruth S

2007-05-30

Early forebrain development is characterized by extensive proliferation of neural precursors coupled with complex structural transformations; however, little is known regarding the mechanisms by which these processes are integrated. Here, we show that deficiency of the cell cycle regulatory protein, E2F4, results in the loss of ventral telencephalic structures and impaired self-renewal of neural precursor cells. The mechanism underlying aberrant ventral patterning lies in a dramatic loss of Sonic hedgehog (Shh) expression specifically in this region. The E2F4-deficient phenotype can be recapitulated by interbreeding mice heterozygous for E2F4 with those lacking one allele of Shh, suggesting a genetic interaction between these pathways. Treatment of E2F4-deficient cells with a Hh agonist rescues stem cell self-renewal and cells expressing the homeodomain proteins that specify the ventral telencephalic structures. Finally, we show that E2F4 deficiency results in impaired activity of Shh forebrain-specific enhancers. In conclusion, these studies establish a novel requirement for the cell cycle regulatory protein, E2F4, in the development of the ventral telencephalon.

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

Nakayama, Hironao; Department of Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115; Division of Cell Growth and Tumor Regulation, Proteo-Science Center, Ehime University, Toon, Ehime 791-0295

Class 3 semaphorins were discovered as a family of axon guidance molecules, but are now known to be involved in diverse biologic processes. In this study, we investigated the anti-angiogenic potential of SEMA3E and SEMA3F (SEMA3E&F) in infantile hemangioma (IH). IH is a common vascular tumor that involves both vasculogenesis and angiogenesis. Our lab has identified and isolated hemangioma stem cells (HemSC), glucose transporter 1 positive (GLUT1{sup +}) endothelial cells (designated as GLUT1{sup sel} cells) based on anti-GLUT1 magnetic beads selection and GLUT1-negative endothelial cells (named HemEC). We have shown that these types of cells play important roles in hemangiogenesis.more » We report here that SEMA3E inhibited HemEC migration and proliferation while SEMA3F was able to suppress the migration and proliferation in all three types of cells. Confocal microscopy showed that stress fibers in HemEC were reduced by SEMA3E&F and that stress fibers in HemSC were decreased by SEMA3F, which led to cytoskeletal collapse and loss of cell motility in both cell types. Additionally, SEMA3E&F were able to inhibit vascular endothelial growth factor (VEGF)-induced sprouts in all three types of cells. Further, SEMA3E&F reduced the level of p-VEGFR2 and its downstream p-ERK in HemEC. These results demonstrate that SEMA3E&F inhibit IH cell proliferation and suppress the angiogenic activities of migration and sprout formation. SEMA3E&F may have therapeutic potential to treat or prevent growth of highly proliferative IH. - Highlights: • SEMA3E&F reduce actin stress fibers and induce cytoskeletal collapse in HemEC. • SEMA3E&F inhibit angiogenic activities of HemEC. • SEMA3E&F can interrupt the VEGF-A-VEGFR2-ERK signaling pathway in HemEC. • Plexin D1 and NRP2 are induced during HemSC/GLUT1{sup sel}-to-EC differentiation.« less

Atypical E2f functions are critical for pancreas polyploidization

PubMed Central

Moreno, Eva; Toussaint, Mathilda J. M.; Tooten, Peter C. J.; van Essen, Saskia C.; van Liere, Elsbeth A.; Youssef, Sameh A.; Bongiovanni, Laura; de Bruin, Alain

2018-01-01

The presence of polyploid cells in the endocrine and exocrine pancreas has been reported for four decades. In rodents, pancreatic polyploidization is initiated after weaning and the number of polyploid cells increases with age. Surprisingly the molecular regulators and biological functions of polyploidization in the pancreas are still unknown. We discovered that atypical E2f activity is essential for polyploidization in the pancreas, using an inducible Cre/LoxP approach in new-born mice to delete ubiquitously the atypical E2f transcription factors, E2f7 and E2f8. In contrast to its critical role in embryonic survival, conditional deletion of both of both atypical E2fs in newborn mice had no impact on postnatal survival and mice lived until old age. However, deficiency of E2f7 or E2f8 alone was sufficient to suppress polyploidization in the pancreas and associated with only a minor decrease in blood serum levels of glucose, insulin, amylase and lipase under 4 hours starvation condition compared to wildtype littermates. In mice with fewer pancreatic polyploid cells that were fed ad libitum, no major impact on hormones or enzymes levels was observed. In summary, we identified atypical E2fs to be essential for polyploidization in the pancreas and discovered that postnatal induced loss of both atypical E2fs in many organs is compatible with life until old age. PMID:29329320

Atypical E2f functions are critical for pancreas polyploidization.

PubMed

Matondo, Ramadhan B; Moreno, Eva; Toussaint, Mathilda J M; Tooten, Peter C J; van Essen, Saskia C; van Liere, Elsbeth A; Youssef, Sameh A; Bongiovanni, Laura; de Bruin, Alain

2018-01-01

The presence of polyploid cells in the endocrine and exocrine pancreas has been reported for four decades. In rodents, pancreatic polyploidization is initiated after weaning and the number of polyploid cells increases with age. Surprisingly the molecular regulators and biological functions of polyploidization in the pancreas are still unknown. We discovered that atypical E2f activity is essential for polyploidization in the pancreas, using an inducible Cre/LoxP approach in new-born mice to delete ubiquitously the atypical E2f transcription factors, E2f7 and E2f8. In contrast to its critical role in embryonic survival, conditional deletion of both of both atypical E2fs in newborn mice had no impact on postnatal survival and mice lived until old age. However, deficiency of E2f7 or E2f8 alone was sufficient to suppress polyploidization in the pancreas and associated with only a minor decrease in blood serum levels of glucose, insulin, amylase and lipase under 4 hours starvation condition compared to wildtype littermates. In mice with fewer pancreatic polyploid cells that were fed ad libitum, no major impact on hormones or enzymes levels was observed. In summary, we identified atypical E2fs to be essential for polyploidization in the pancreas and discovered that postnatal induced loss of both atypical E2fs in many organs is compatible with life until old age.

The acute autonomic stress response and amniotic fluid glucocorticoids in second-trimester pregnant women.

PubMed

La Marca-Ghaemmaghami, Pearl; Dainese, Sara M; La Marca, Roberto; Zimmermann, Roland; Ehlert, Ulrike

2015-01-01

The maternal autonomic nervous system (ANS) has received little attention in the investigation of biological mechanisms linking prenatal stress to fetal cortisol (F) excess. In vitro, norepinephrine and epinephrine inhibit placental 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2), which protects the fetus from F overexposure by inactivating it to cortisone (E). Here, we investigated the acute ANS stress response to an amniocentesis and its association with amniotic fluid F, E, and E/(E + F) as a marker of fetoplacental 11β-HSD2 activity. An aliquot of amniotic fluid was obtained from 34 healthy, second-trimester pregnant women undergoing amniocentesis. Repeated assessment of mood states served to examine the psychological stress response to amniocentesis. Saliva samples were collected to measure stress-induced changes in salivary α-amylase concentrations in response to amniocentesis. Cardiac parameters were measured continuously. Undergoing amniocentesis induced significant psychological and autonomic alterations. Low-frequency (LF)/high-frequency (HF) baseline, suggested to reflect sympathovagal balance, was negatively correlated with amniotic E/(E + F) (r=-0.53, p = .002) and positively with F (r = 0.62, p < .001). In contrast, a stronger acute LF/HF response was positively associated with E/(E + F) (r = 0.44, p = .012) and negatively with F (r=-0.40, p = .025). These findings suggest that the maternal ANS is involved in the regulation of the fetoplacental barrier to stress. Allostatic processes may have been initiated to counterbalance acute stress effects. In contrast, higher LF/HF baseline values, possibly indicative of chronic stress exposure, may have inhibited 11β-HSD2 activity in the fetoplacental unit. These results parallel animal findings of up-regulated placental 11β-HSD2 in response to acute stress but impairment under chronic stress.

Disruption of Mouse Cytochrome P450 4f14 (Cyp4f14 Gene) Causes Severe Perturbations in Vitamin E Metabolism*

PubMed Central

Bardowell, Sabrina A.; Duan, Faping; Manor, Danny; Swanson, Joy E.; Parker, Robert S.

2012-01-01

Vitamin E is a family of naturally occurring and structurally related lipophilic antioxidants, one of which, α-tocopherol (α-TOH), selectively accumulates in vertebrate tissues. The ω-hydroxylase cytochrome P450–4F2 (CYP4F2) is the only human enzyme shown to metabolize vitamin E. Using cDNA cloning, cell culture expression, and activity assays, we identified Cyp4f14 as a functional murine ortholog of CYP4F2. We then investigated the effect of Cyp4f14 deletion on vitamin E metabolism and status in vivo. Cyp4f14-null mice exhibited substrate-specific reductions in liver microsomal vitamin E-ω-hydroxylase activity ranging from 93% (γ-TOH) to 48% (γ-tocotrienol). In vivo data obtained from metabolic cage studies showed whole-body reductions in metabolism of γ-TOH of 90% and of 68% for δ- and α-TOH. This metabolic deficit in Cyp4f14−/− mice was partially offset by increased fecal excretion of nonmetabolized tocopherols and of novel ω-1- and ω-2-hydroxytocopherols. 12′-OH-γ-TOH represented 41% of whole-body production of γ-TOH metabolites in Cyp4f14−/− mice fed a soybean oil diet. Despite these counterbalancing mechanisms, Cyp4f14-null mice fed this diet for 6 weeks hyper-accumulated γ-TOH (2-fold increase over wild-type littermates) in all tissues and appeared normal. We conclude that CYP4F14 is the major but not the only vitamin E-ω-hydroxylase in mice. Its disruption significantly impairs whole-body vitamin E metabolism and alters the widely conserved phenotype of preferential tissue deposition of α-TOH. This model animal and its derivatives will be valuable in determining the biological actions of specific tocopherols and tocotrienols in vivo. PMID:22665481

A specific, nonproliferative role for E2F-5 in choroid plexus function revealed by gene targeting

PubMed Central

Lindeman, Geoffrey J.; Dagnino, Lina; Gaubatz, Stefan; Xu, Yuhui; Bronson, Roderick T.; Warren, Henry B.; Livingston, David M.

1998-01-01

Homozygous E2F-5 knockout embryos and mice have been generated. Although embryonic development appeared normal, newborn mice developed nonobstructive hydrocephalus, suggesting excessive cerebrospinal fluid (CSF) production. Although the CSF-producing choroid plexus displayed normal cellular organization, it contained abundant electron-lucent epithelial cells, consistent with excessive CSF secretory activity. Moreover, E2F-5 CNS expression in normal animals was largely confined to the choroid plexus. Cell cycle kinetics were not perturbed in homozygous knockout embryo fibroblasts. Thus, E2F-5 is not essential for cell proliferation. Rather, it affects the secretory behavior of a differentiated neural tissue. PMID:9553039

Protective effect of quercetin on high-fat diet-induced non-alcoholic fatty liver disease in mice is mediated by modulating intestinal microbiota imbalance and related gut-liver axis activation.

PubMed

Porras, David; Nistal, Esther; Martínez-Flórez, Susana; Pisonero-Vaquero, Sandra; Olcoz, José Luis; Jover, Ramiro; González-Gallego, Javier; García-Mediavilla, María Victoria; Sánchez-Campos, Sonia

2017-01-01

Gut microbiota is involved in obesity, metabolic syndrome and the progression of nonalcoholic fatty liver disease (NAFLD). It has been recently suggested that the flavonoid quercetin may have the ability to modulate the intestinal microbiota composition, suggesting a prebiotic capacity which highlights a great therapeutic potential in NAFLD. The present study aims to investigate benefits of experimental treatment with quercetin on gut microbial balance and related gut-liver axis activation in a nutritional animal model of NAFLD associated to obesity. C57BL/6J mice were challenged with high fat diet (HFD) supplemented or not with quercetin for 16 weeks. HFD induced obesity, metabolic syndrome and the development of hepatic steatosis as main hepatic histological finding. Increased accumulation of intrahepatic lipids was associated with altered gene expression related to lipid metabolism, as a result of deregulation of their major modulators. Quercetin supplementation decreased insulin resistance and NAFLD activity score, by reducing the intrahepatic lipid accumulation through its ability to modulate lipid metabolism gene expression, cytochrome P450 2E1 (CYP2E1)-dependent lipoperoxidation and related lipotoxicity. Microbiota composition was determined via 16S ribosomal RNA Illumina next-generation sequencing. Metagenomic studies revealed HFD-dependent differences at phylum, class and genus levels leading to dysbiosis, characterized by an increase in Firmicutes/Bacteroidetes ratio and in Gram-negative bacteria, and a dramatically increased detection of Helicobacter genus. Dysbiosis was accompanied by endotoxemia, intestinal barrier dysfunction and gut-liver axis alteration and subsequent inflammatory gene overexpression. Dysbiosis-mediated toll-like receptor 4 (TLR-4)-NF-κB signaling pathway activation was associated with inflammasome initiation response and reticulum stress pathway induction. Quercetin reverted gut microbiota imbalance and related endotoxemia-mediated TLR-4 pathway induction, with subsequent inhibition of inflammasome response and reticulum stress pathway activation, leading to the blockage of lipid metabolism gene expression deregulation. Our results support the suitability of quercetin as a therapeutic approach for obesity-associated NAFLD via its anti-inflammatory, antioxidant and prebiotic integrative response. Copyright © 2016 Elsevier Inc. All rights reserved.

[Stimulation of human hepatic stellate cells by cytochrome P4502E1-mediated oxidative stress].

PubMed

Li, Jing; Liu, Tian-hui; You, Hong; Xu, You-qing; Wang, Chen

2010-08-01

To explore the stimulation of human hepatic stellate cells by Cytochrome P4502E1-mediated oxidative stress. HepG2-line was transfected with human CYP2E1 plasmid (HepG2/CYP2E1) and empty plasmid (HepG2/PCI) respectively. The CYP2E1 expression was evaluated with RT-PCR and Western blot. MDA was measured in culture medium of HepG2 cell lines. LX2 was co-incubated with HepG2/CYP2E1, HepG2/PCI and HepG2 respectively. The level of hydroxyproline in culture medium was examined in 48 hours and the cells were lysated and total RNA and protein were extracted. COL-1 and MMP2 mRNA levels were detected by RT-PCR and analyzed semi-quantitatively. PICP proteins were measured by ELISA. Zymography was performed to investigate MMP2 enzymatic activities. (1) MDA from the HepG2 which (HepG2/CYP2E1)express human CYP2E1 (6.51+/-0.25) was significantly higher than that from the HepG2 which do not (HepG2/PCI) express human CYP2E1 (3.07+/-0.29) and HepG2 alone (2.57+/-0.29). (F=22.66, all P<0.01). (2) After co-incubated for 48 hours,the level of hydroxyproline in culture medium (35.24+/-3.52) excreted from CYP2E1/LX2 could significantly increase (F=58.89, P is less than 0.01). PICP protein (540.01+/-11.38) excreted from CYP2E1/LX2 was significantly increased (F=124.97, P<0.01). Zymography showed MMP2 gene expression and enzymatic activities of MMP2 had no difference among the groups (F=0.29, P>0.05) (F=0.33, P>0.05). CYP2E1 derived oxidative stress mediated stimulation of collagen I synthesis by hepatic stellate cells. Hydroxyproline excreted by LX2 was increased by CYP2E1. COL-1mRNA had no difference among the groups (F=0.73, P>0.05).

mTORC1 and CK2 coordinate ternary and eIF4F complex assembly

PubMed Central

Gandin, Valentina; Masvidal, Laia; Cargnello, Marie; Gyenis, Laszlo; McLaughlan, Shannon; Cai, Yutian; Tenkerian, Clara; Morita, Masahiro; Balanathan, Preetika; Jean-Jean, Olivier; Stambolic, Vuk; Trost, Matthias; Furic, Luc; Larose, Louise; Koromilas, Antonis E.; Asano, Katsura; Litchfield, David; Larsson, Ola; Topisirovic, Ivan

2016-01-01

Ternary complex (TC) and eIF4F complex assembly are the two major rate-limiting steps in translation initiation regulated by eIF2α phosphorylation and the mTOR/4E-BP pathway, respectively. How TC and eIF4F assembly are coordinated, however, remains largely unknown. We show that mTOR suppresses translation of mRNAs activated under short-term stress wherein TC recycling is attenuated by eIF2α phosphorylation. During acute nutrient or growth factor stimulation, mTORC1 induces eIF2β phosphorylation and recruitment of NCK1 to eIF2, decreases eIF2α phosphorylation and bolsters TC recycling. Accordingly, eIF2β mediates the effect of mTORC1 on protein synthesis and proliferation. In addition, we demonstrate a formerly undocumented role for CK2 in regulation of translation initiation, whereby CK2 stimulates phosphorylation of eIF2β and simultaneously bolsters eIF4F complex assembly via the mTORC1/4E-BP pathway. These findings imply a previously unrecognized mode of translation regulation, whereby mTORC1 and CK2 coordinate TC and eIF4F complex assembly to stimulate cell proliferation. PMID:27040916

Interrupted E2F1-miR-34c-SCF negative feedback loop by hyper-methylation promotes colorectal cancer cell proliferation

PubMed Central

Yang, Shu; Wu, Bo; Sun, Haimei; Ji, Fengqing; Sun, Tingyi; Zhao, Yan; Zhou, Deshan

2015-01-01

Tumour suppressor miR-34c deficiency resulted from hyper-methylation in its promoter is believed to be one of the main causes of colorectal cancer (CRC). Till date, miR-34c has been validated as a direct target of p53; but previous evidence suggested other transcription factor(s) must be involved in miR-34c transcription. In the present study, we in the first place identified a core promoter region (−1118 to −883 bp) of pre-miR-34c which was embedded within a hyper-methylated CpG island. Secondly, E2F1 promoted miR-34c transcription by physical interaction with the miR-34c promoter at site −897 to −889 bp. The transcriptional activating effect of E2F1 on miR-34c was in a p53 independent manner but profoundly promoted in the presence of p53 with exposure to 5-aza-2′-deoxycytidine (DAC). Thirdly, stem cell factor (SCF), a miR-34c target, was specifically reduced upon an introduction of E2F1 which lead to suppression of CRC cell proliferation. The E2F1-suppressed cell proliferation was partially abrogated by additional miR-34c inhibitor, indicating that the anti-proliferation effect of E2F1 was probably through activating miR-34c-SCF axis. Finally, SCF/KIT signalling increased E2F1 production by reducing its proteosomal degradation dependent on PI3K/Akt-GSK3β pathway. In conclusion, our results suggested the existence of E2F1-miR-34c-SCF negative feedback loop which was interrupted by the hyper-methylation of miR-34c promoter in CRC cells and increased cell proliferation. PMID:26704889

The DP-1 transcription factor is required for keratinocyte growth and epidermal stratification.

PubMed

Chang, Wing Y; Bryce, Dawn M; D'Souza, Sudhir J A; Dagnino, Lina

2004-12-03

The epidermis is a stratified epithelium constantly replenished through the ability of keratinocytes in its basal layer to proliferate and self-renew. The epidermis arises from a single-cell layer ectoderm during embryogenesis. Large proliferative capacity is central to ectodermal cell and basal keratinocyte function. DP-1, a heterodimeric partner of E2F transcription factors, is highly expressed in the ectoderm and all epidermal layers during embryogenesis. To investigate the role of DP-1 in epidermal morphogenesis, we inhibited DP-1 activity through exogenous expression of a dominant-negative mutant (dnDP-1). Expression of the dnDP-1 mutant interferes with binding of E2F/DP-1 heterodimers to DNA and inhibits DNA replication, as well as cyclin A mRNA and protein expression. Chromatin immunoprecipitation analysis demonstrated that the cyclin A promoter is predominantly bound in proliferating keratinocytes by complexes containing E2F-3 and E2F-4. Thus, the mechanisms of decreased expression of cyclin A in the presence of dnDP-1 seem to involve inactivation of DP-1 complexes containing E2F-3 and E2F-4. To assess the consequences on epidermal morphogenesis of inhibiting DP-1 activity, we expressed dnDP-1 in rat epithelial keratinocytes in organotypic culture and observed that DP-1 inhibition negatively affected stratification of these cells. Likewise, expression of dnDP-1 in embryonic ectoderm explants produced extensive disorganization of subsequently formed epidermal basal and suprabasal layers, interfering with normal epidermal formation. We conclude that DP-1 activity is required for normal epidermal morphogenesis and ectoderm-to-epidermis transition.

The prohibitin-repressive interaction with E2F1 is rapidly inhibited by androgen signalling in prostate cancer cells

PubMed Central

Koushyar, S; Economides, G; Zaat, S; Jiang, W; Bevan, C L; Dart, D A

2017-01-01

Prohibitin (PHB) is a tumour suppressor molecule with pleiotropic activities across several cellular compartments including mitochondria, cell membrane and the nucleus. PHB and the steroid-activated androgen receptor (AR) have an interplay where AR downregulates PHB, and PHB represses AR. Additionally, their cellular locations and chromatin interactions are in dynamic opposition. We investigated the mechanisms of cell cycle inhibition by PHB and how this is modulated by AR in prostate cancer. Using a prostate cancer cell line overexpressing PHB, we analysed the gene expression changes associated with PHB-mediated cell cycle arrest. Over 1000 gene expression changes were found to be significant and gene ontology analysis confirmed PHB-mediated repression of genes essential for DNA replication and synthesis, for example, MCMs and TK1, via an E2F1 regulated pathway—agreeing with its G1/S cell cycle arrest activity. PHB is known to inhibit E2F1-mediated transcription, and the PHB:E2F1 interaction was seen in LNCaP nuclear extracts, which was then reduced by androgen treatment. Upon two-dimensional western blot analysis, the PHB protein itself showed androgen-mediated charge differentiation (only in AR-positive cells), indicating a potential dephosphorylation event. Kinexus phosphoprotein array analysis indicated that Src kinase was the main interacting intracellular signalling hub in androgen-treated LNCaP cells, and that Src inhibition could reduce this AR-mediated charge differentiation. PHB charge change may be associated with rapid dissociation from chromatin and E2F1, allowing the cell cycle to proceed. The AR and androgens may deactivate the repressive functions of PHB upon E2F1 leading to cell cycle progression, and indicates a role for AR in DNA replication licensing. PMID:28504694

Tandem E2F Binding Sites in the Promoter of the p107 Cell Cycle Regulator Control p107 Expression and Its Cellular Functions

PubMed Central

Burkhart, Deborah L.; Wirt, Stacey E.; Zmoos, Anne-Flore; Kareta, Michael S.; Sage, Julien

2010-01-01

The retinoblastoma tumor suppressor (Rb) is a potent and ubiquitously expressed cell cycle regulator, but patients with a germline Rb mutation develop a very specific tumor spectrum. This surprising observation raises the possibility that mechanisms that compensate for loss of Rb function are present or activated in many cell types. In particular, p107, a protein related to Rb, has been shown to functionally overlap for loss of Rb in several cellular contexts. To investigate the mechanisms underlying this functional redundancy between Rb and p107 in vivo, we used gene targeting in embryonic stem cells to engineer point mutations in two consensus E2F binding sites in the endogenous p107 promoter. Analysis of normal and mutant cells by gene expression and chromatin immunoprecipitation assays showed that members of the Rb and E2F families directly bound these two sites. Furthermore, we found that these two E2F sites controlled both the repression of p107 in quiescent cells and also its activation in cycling cells, as well as in Rb mutant cells. Cell cycle assays further indicated that activation of p107 transcription during S phase through the two E2F binding sites was critical for controlled cell cycle progression, uncovering a specific role for p107 to slow proliferation in mammalian cells. Direct transcriptional repression of p107 by Rb and E2F family members provides a molecular mechanism for a critical negative feedback loop during cell cycle progression and tumorigenesis. These experiments also suggest novel therapeutic strategies to increase the p107 levels in tumor cells. PMID:20585628

Deregulation of RB1 expression by loss of imprinting in human hepatocellular carcinoma.

PubMed

Anwar, Sumadi Lukman; Krech, Till; Hasemeier, Britta; Schipper, Elisa; Schweitzer, Nora; Vogel, Arndt; Kreipe, Hans; Lehmann, Ulrich

2014-08-01

The tumour suppressor gene RB1 is frequently silenced in many different types of human cancer, including hepatocellular carcinoma (HCC). However, mutations of the RB1 gene are relatively rare in HCC. A systematic screen for the identification of imprinted genes deregulated in human HCC revealed that RB1 shows imprint abnormalities in a high proportion of primary patient samples. Altogether, 40% of the HCC specimens (16/40) showed hyper- or hypomethylation at the CpG island in intron 2 of the RB1 gene. Re-analysis of publicly available genome-wide DNA methylation data confirmed these findings in two independent HCC cohorts. Loss of correct DNA methylation patterns at the RB1 locus leads to the aberrant expression of an alternative RB1-E2B transcript, as measured by quantitative real-time PCR. Demethylation at the intron 2 CpG island by DNMT1 knock-down or aza-deoxycytidine (DAC) treatment stimulated expression of the RB1-E2B transcript, accompanied by diminished RB1 main transcript expression. No aberrant DNA methylation was found at the RB1 locus in hepatocellular adenoma (HCA, n = 10), focal nodular hyperplasia (FNH, n = 5) and their corresponding adjacent liver tissue specimens. Deregulated RB1 expression due to hyper- or hypomethylation in intron 2 of the RB1 gene is found in tumours without loss of heterozygosity and is associated with a decrease in overall survival (p = 0.032) if caused by hypermethylation of CpG85. This unequivocally demonstrates that loss of imprinting represents an important additional mechanism for RB1 pathway inactivation in human HCC, complementing well-described molecular defects. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Worldwide U.S. Active Duty Military Deaths. Alphabetical Index by Name, 1 October 1979 Through 30 September 1994

DTIC Science & Technology

1994-09-30

DE LME NDO G E R A R D O MAR I GZA A I R F O R C E D E LMUNDO L I LY F E D E R I S NAVY D E LOACH B O B B Y D E A N A I R F ORCE D E LOGE B...YAN LAMON EAR LE JAME S ARTHUR EAR LEY KEN W EAR LEY R OB E R T WI L L IAM J R EAR LS M I CHAE L G EAR LS OMAR DALE EAR LY BE N JAMIN J R...8 9 B R OOK LYN E 0 4 2 2 F e b 8 2 KEN TON E 0 7 14 D e c 9 1 R OCKH I L L 0 0 2 1 4 J u l 8 1 T E XAS C I T Y E 0 6 24 Oc t 7 9

The C-terminal domain of the betaine carrier BetP of Corynebacterium glutamicum is directly involved in sensing K+ as an osmotic stimulus.

PubMed

Schiller, Dirk; Rübenhagen, René; Krämer, Reinhard; Morbach, Susanne

2004-05-18

The glycine betaine carrier BetP of Corynebacterium glutamicum was recently shown to function both as an osmosensor and as an osmoregulator in proteoliposomes by sensing changes in the internal K(+) concentration as a measure of hyperosmotic stress. In vivo analysis of mutants carrying deletions at the C-terminal extension of BetP indicated that this domain participates in osmostress-dependent activity regulation. To address the question, whether a putative K(+) sensor is located within the C-terminal domain, several mutants with truncations in this domain were purified and reconstituted in proteoliposomes of Escherichia coli phospholipids, since this in vitro system allowed variation of the K(+) concentration at the lumenal side. Truncation of 12 amino acids led to a partly deregulated BetP in terms of osmoregulation; however, K(+) sensitivity was not impaired in this mutant. The deletion of 25 amino acid residues at the C-terminal end of BetP led to both deregulation of the carrier activity, i.e., high activity independent of external osmolality, and loss of K(+)-dependent transport stimulation, indicating that this region of the C-terminal domain is necessary for K(+) sensing and/or K(+)-dependent carrier activation. Immunological and proteolysis analyses showed that BetP and its recombinant forms were reconstituted in a right-side-out orientation, i.e., the C-terminal domain faces the lumen of the proteoliposomes and is thus able to detect the K(+) signal at the inside. This is the first experimental demonstration of a direct connection between an osmotic stimulus, i.e., the change in internal K(+), and a putative sensor domain.

Comparative Analysis of Toxic Responses of Organic Extracts from Diesel and Selected Alternative Fuels Engine Emissions in Human Lung BEAS-2B Cells.

PubMed

Libalova, Helena; Rossner, Pavel; Vrbova, Kristyna; Brzicova, Tana; Sikorova, Jitka; Vojtisek-Lom, Michal; Beranek, Vit; Klema, Jiri; Ciganek, Miroslav; Neca, Jiri; Pencikova, Katerina; Machala, Miroslav; Topinka, Jan

2016-11-03

This study used toxicogenomics to identify the complex biological response of human lung BEAS-2B cells treated with organic components of particulate matter in the exhaust of a diesel engine. First, we characterized particles from standard diesel (B0), biodiesel (methylesters of rapeseed oil) in its neat form (B100) and 30% by volume blend with diesel fuel (B30), and neat hydrotreated vegetable oil (NEXBTL100). The concentration of polycyclic aromatic hydrocarbons (PAHs) and their derivatives in organic extracts was the lowest for NEXBTL100 and higher for biodiesel. We further analyzed global gene expression changes in BEAS-2B cells following 4 h and 24 h treatment with extracts. The concentrations of 50 µg extract/mL induced a similar molecular response. The common processes induced after 4 h treatment included antioxidant defense, metabolism of xenobiotics and lipids, suppression of pro-apoptotic stimuli, or induction of plasminogen activating cascade; 24 h treatment affected fewer processes, particularly those involved in detoxification of xenobiotics, including PAHs. The majority of distinctively deregulated genes detected after both 4 h and 24 h treatment were induced by NEXBTL100; the deregulated genes included, e.g., those involved in antioxidant defense and cell cycle regulation and proliferation. B100 extract, with the highest PAH concentrations, additionally affected several cell cycle regulatory genes and p38 signaling.

Resetting cancer stem cell regulatory nodes upon MYC inhibition.

PubMed

Galardi, Silvia; Savino, Mauro; Scagnoli, Fiorella; Pellegatta, Serena; Pisati, Federica; Zambelli, Federico; Illi, Barbara; Annibali, Daniela; Beji, Sara; Orecchini, Elisa; Alberelli, Maria Adele; Apicella, Clara; Fontanella, Rosaria Anna; Michienzi, Alessandro; Finocchiaro, Gaetano; Farace, Maria Giulia; Pavesi, Giulio; Ciafrè, Silvia Anna; Nasi, Sergio

2016-12-01

MYC deregulation is common in human cancer and has a role in sustaining the aggressive cancer stem cell populations. MYC mediates a broad transcriptional response controlling normal biological programmes, but its activity is not clearly understood. We address MYC function in cancer stem cells through the inducible expression of Omomyc-a MYC-derived polypeptide interfering with MYC activity-taking as model the most lethal brain tumour, glioblastoma. Omomyc bridles the key cancer stemlike cell features and affects the tumour microenvironment, inhibiting angiogenesis. This occurs because Omomyc interferes with proper MYC localization and itself associates with the genome, with a preference for sites occupied by MYC This is accompanied by selective repression of master transcription factors for glioblastoma stemlike cell identity such as OLIG2, POU3F2, SOX2, upregulation of effectors of tumour suppression and differentiation such as ID4, MIAT, PTEN, and modulation of the expression of microRNAs that target molecules implicated in glioblastoma growth and invasion such as EGFR and ZEB1. Data support a novel view of MYC as a network stabilizer that strengthens the regulatory nodes of gene expression networks controlling cell phenotype and highlight Omomyc as model molecule for targeting cancer stem cells. © 2016 The Authors.

E2F4 is required for early eye patterning.

PubMed

Ruzhynsky, Vladimir A; Furimsky, Marosh; Park, David S; Wallace, Valerie A; Slack, Ruth S

2009-01-01

Increasingly, studies reveal novel functions for cell cycle proteins during development. Here, we investigated the role of E2F4 in eye development. E2F4-deficient mouse embryos exhibit severe early eye patterning defects, which are evident from embryonic day 11.5 and characterized by aberrant shape of the optic cup, coloboma as well as abnormal eye pigmentation. Loss of E2F4 is associated with proximal-distal patterning defects in the optic vesicle. These defects are characterized by the expansion of optic stalk marker gene expression to the optic cup and reduced expression of ventral optic cup markers. These defects are associated with a split of Shh expression domain at the ventral midline of the forebrain and expansion of the Shh activity into the ventral optic cup. Despite these patterning defects, early neuronal differentiation and Shh expression in the retina are not affected by E2F4 deletion. Overall, the results of our studies show a novel role of E2F4 in the early eye development. 2009 S. Karger AG, Basel.

E2F4 Promotes Neuronal Regeneration and Functional Recovery after Spinal Cord Injury in Zebrafish

PubMed Central

Sasagawa, Shota; Nishimura, Yuhei; Hayakawa, Yuka; Murakami, Soichiro; Ashikawa, Yoshifumi; Yuge, Mizuki; Okabe, Shiko; Kawaguchi, Koki; Kawase, Reiko; Tanaka, Toshio

2016-01-01

Mammals exhibit poor recovery after spinal cord injury (SCI), whereas non-mammalian vertebrates exhibit significant spontaneous recovery after SCI. The mechanisms underlying this difference have not been fully elucidated; therefore, the purpose of this study was to investigate these mechanisms. Using comparative transcriptome analysis, we demonstrated that genes related to cell cycle were significantly enriched in the genes specifically dysregulated in zebrafish SCI. Most of the cell cycle-related genes dysregulated in zebrafish SCI were down-regulated, possibly through activation of e2f4. Using a larval zebrafish model of SCI, we demonstrated that the recovery of locomotive function and neuronal regeneration after SCI were significantly inhibited in zebrafish treated with an E2F4 inhibitor. These results suggest that activation of e2f4 after SCI may be responsible, at least in part, for the significant recovery in zebrafish. This provides novel insight into the lack of recovery after SCI in mammals and informs potential therapeutic strategies. PMID:27242526

Conservation and divergence of C-terminal domain structure in the retinoblastoma protein family

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

Liban, Tyler J.; Medina, Edgar M.; Tripathi, Sarvind

The retinoblastoma protein (Rb) and the homologous pocket proteins p107 and p130 negatively regulate cell proliferation by binding and inhibiting members of the E2F transcription factor family. The structural features that distinguish Rb from other pocket proteins have been unclear but are critical for understanding their functional diversity and determining why Rb has unique tumor suppressor activities. We describe here important differences in how the Rb and p107 C-terminal domains (CTDs) associate with the coiled-coil and marked-box domains (CMs) of E2Fs. We find that although CTD–CM binding is conserved across protein families, Rb and p107 CTDs show clear preferences formore » different E2Fs. A crystal structure of the p107 CTD bound to E2F5 and its dimer partner DP1 reveals the molecular basis for pocket protein–E2F binding specificity and how cyclin-dependent kinases differentially regulate pocket proteins through CTD phosphorylation. Our structural and biochemical data together with phylogenetic analyses of Rb and E2F proteins support the conclusion that Rb evolved specific structural motifs that confer its unique capacity to bind with high affinity those E2Fs that are the most potent activators of the cell cycle.« less

Lactic acid bacteria increase antiallergic effect of Artemisia princeps pampanini SS-1.

PubMed

Lee, Seung-Hoon; Shin, Yong-Wook; Bae, Eun-Ah; Lee, Bomi; Min, Sungwon; Baek, Nam-In; Chung, Hae-Gon; Kim, Nam-Jae; Kim, Dong-Hyun

2006-09-01

Artemisia princeps Pampanini, which is called Ssajuarissuk in Korean (SS-1), was fermented with lactic acid bacteria (LAB) and their passive cutaneous anaphylaxis reaction-inhibitory activity was investigated. Of these fermented agents, SS-1 extract fermented with Bifidobacterium infantis K-525 (F-SS-1) most effectively inhibited the release of P-hexosamindase from RBL-2H3 cells induced IgE. In IgE-induced RBL-2H3 cells, F-SS-1 inhibited proinflammatory cytokines IL-6 and TNF-alpha mRNA expression. Oral administration of SS-1 and F-SS-1 to mice inhibited passive cutaneous anaphylaxis (PCA) reaction induced by IgE and scratching behaviors induced by compound 48/80. The inhibitory activity of F-SS-1 against scratching behaviors was more effective than that of SS-1. These findings suggest that the fermentation of SS-1 with LAB can increase its antiallergic activity.

A Herpesvirus Ribosome-Associated, RNA-Binding Protein Confers a Growth Advantage upon Mutants Deficient in a GADD34-Related Function†

PubMed Central

Mulvey, Matthew; Poppers, Jeremy; Ladd, Alison; Mohr, Ian

1999-01-01

The herpes simplex virus type 1 γ34.5 gene product and the cellular GADD34 protein both contain similar domains that can regulate the activity of eukaryotic initiation factor 2 (eIF2), a critical translation initiation factor. Viral mutants that lack the GADD34-related function grow poorly on a variety of malignant human cells, as activation of the cellular PKR kinase leads to the accumulation of inactive, phosphorylated eIF2 at late times postinfection. Termination of translation prior to the completion of the viral reproductive cycle leads to impaired growth. Extragenic suppressors that regain the ability to synthesize proteins efficiently in the absence of the viral GADD34-related function have been isolated. These suppressor alleles are dominant in trans and affect the steady-state accumulation of several viral mRNA species. We demonstrate that deregulated expression of Us11, a virus-encoded RNA-binding, ribosome-associated protein is necessary and sufficient to confer a growth advantage upon viral mutants that lack a GADD34-related function. Ectopic expression of Us11 reduces the accumulation of the activated cellular PKR kinase and allows for sustained protein synthesis. Thus, an RNA-binding, ribosome-associated protein (Us11) and a GADD34-related protein (γ34.5) both function in a signal pathway that regulates translation by modulating eIF2 phosphorylation. PMID:10074192

The quiet and disturbed time performance of the IRI 2012 within 90°-130°E longitude sector during solar cycle 24

NASA Astrophysics Data System (ADS)

Bhuyan, Pradip; Yokoyama, Tatsuhiro; Supnithi, Pornchai; Kalita, Bitap Raj; Wang, Kehe; Komolmis, Tharadol; Yatini, Clara

2016-07-01

The performance of the IRI 2012 model is examined for the double peaked solar cycle 24 in the low latitude region of 90-130oE longitude in the context of the global longitudinal wave number four structure (WN4). The monthly mean values of the foF2 and the hmF2(if available) measurements at low and low mid-latitude stations Dibrugarh (27.5°N, 95°E), Hainan (19.2°N,109.7°E),Okinawa (26.5°N,128°E) and Cocos Island (12.2°S,96.8°E) during quiet times and Dibrugarh (27.5°N, 95°E), Chiang Mai (18.76°N,98.93°E), Chumphon (10.72°N,99.37°E), Kototabang (0.2°S,100.32°E) and Cocos Island (12.2°S,96.8°E ) during the disturbed days of a severe geomagnetic storm are investigated. These stations are located under the strongest peak of the longitudinal WN4 structure in NmF2 along 90-130°E longitudes. The IRI is quite successful in predicting the seasonal averages of NmF2 over this region except in the equinox afternoon period where IRI underestimates the NmF2 in low latitudes. When the monthly mean measured data is compared with IRI, the difference between the IRI model predictions and the measurements are found to follow a systematic pattern. The IRI-2012 with CCIR options slightly underestimates foF2 over Dibrugarh in day time and overestimates in the night time. The amount of underestimation varies from month to month and also depends on the solar activity levels. The IRI also underestimated the day time hmF2 and overestimated the night time hmF2 over Dibrugarh. In case of Hainan, the IRI overestimates the NmF2 in the equinox months and generally in the afternoon to post sunset period. The model values are closer in the solstice than in the equinox. In Okinawa, the trend reverses and the IRI overestimates the NmF2 in the day time and underestimates in the night time. The IRI overestimated the day time hmF2 and underestimated the night time hmF2 over Okinawa. In case of Cocos Island which lies almost on the EIA anomaly region of the southern hemisphere, IRI underestimates the peak day time NmF2 in most months. The measurements are closer to the model values in the forenoon period and in the low solar activity period. The striking feature across all the stations is the IRI underestimation of the post sunset enhancement of NmF2 in low latitudes. During the severe geomagnetic storm of 17-18 March, 2015, the IRI was not able to replicate the inhibition of EIA on the next day i.e. 18 March as observed in the 100°E longitude.

Identification of estrogenic and antiestrogenic activities of respirable diesel exhaust particles by bioassay-directed fractionation.

PubMed

Oh, Seung Min; Ryu, Byung Taek; Chung, Kyu Hyuck

2008-01-01

Bioassay-directed fractionation was performed to identify causative chemical groups of DEPs with estrogenic and antiestrogenic activities. Bioassay-directed fractionation consists of a cell bioassay (E-SCREEN) in conjunction with acid-base partitioning (F1 and F2) and silica gel column fractionation of neutral fractions (F3-F7). Crude extract (CE) of DEPs in dichloromethane (DCM) exhibited both estrogenic and antiestrogenic activity. Estrogenic activity of CE and some fractions (F1, F2, F3, F5 and F6) was induced through estrogen receptor (ER)-mediated pathways. In particular, the acid polar fraction (F2) of DEPs, which contains phenols, induced high levels of estrogenic activity compared to other fractions. The estrogenic activity of F2 (610.80 pg-bio-EEQ/g-DEPs) was higher than that of the total estrogenic activity of CE (222.22 pg-bio-EEQ/g-DEPs). This result indicates that the estrogenic activity induced by causative estrogenic fraction (F2) may be antagonized by unidentified chemicals in DEPs. On the other hand, non-polar fractions (F3 and F4) of DEPs include aliphatic and chlorinated hydrocarbon, polyaromatic hydrocarbons, and their alkyl derivatives, which play an important role in the antiestrogenic activity of DEPs. In particular, F4, which contains PAH and its derivatives, showed the highest antiestrogenic activity. Since in our previous study, dibenzo(a, h)anthracene and chrysene were identified in F4, and these chemicals have antiestrogenic activity, we assume that these chemicals are the major causative chemicals with antiestrogenic activity in DEPs. In contrast to the estrogenic activity of DEPs, antiestrogenic activity of CE was stronger than that of antiestrogenic fractions (F3 and F4) at non-cytotoxic concentrations, indicating that additive or synergistic effects by unidentified chemicals contained in DEPs occurred.

Fluoride induces endoplasmic reticulum stress and inhibits protein synthesis and secretion.

PubMed

Sharma, Ramaswamy; Tsuchiya, Masahiro; Bartlett, John D

2008-09-01

Exposure to excessive amounts of fluoride (F(-)) causes dental fluorosis in susceptible individuals; however, the mechanism of F(-)-induced toxicity is unclear. Previously, we have shown that high-dose F(-) activates the unfolded protein response (UPR) in ameloblasts that are responsible for dental enamel formation. The UPR is a signaling pathway responsible for either alleviating endoplasmic reticulum (ER) stress or for inducing apoptosis of the stressed cells. In this study we determined if low-dose F(-) causes ER stress and activates the UPR, and we also determined whether F(-) interferes with the secretion of proteins from the ER. We stably transfected the ameloblast-derived LS8 cell line with secreted alkaline phosphatase (SEAP) and determined activity and localization of SEAP and F(-)-mediated induction of UPR proteins. Also, incisors from mice given drinking water containing various concentrations of F(-) were examined for eucaryotic initiation factor-2, subunit alpha (eIF2alpha) phosphorylation. We found that F(-) decreases the extracellular secretion of SEAP in a linear, dose-dependent manner. We also found a corresponding increase in the intracellular accumulation of SEAP after exposure to F(-). These changes are associated with the induction of UPR proteins such as the molecular chaperone BiP and phosphorylation of the UPR sensor PKR-like ER kinase, and its substrate, eIF2alpha. Importantly, F(-)-induced phosphorylation of eIF2alphawas confirmed in vivo. These data suggest that F(-) initiates an ER stress response in ameloblasts that interferes with protein synthesis and secretion. Consequently, ameloblast function during enamel development may be impaired, and this may culminate in dental fluorosis.

Inhibition of Retinoblastoma Protein Inactivation

DTIC Science & Technology

2017-11-01

SUBJECT TERMS cell cycle, Retinoblastoma protein, E2F transcription factor, high throughput screen, drug discovery, x-ray crystallography 16. SECURITY...screening by x-ray crystallography . 2.0 KEYWORDS Retinoblastoma (Rb) pathway, E2F transcription factor, cancer, cell-cycle inhibition, activation...modulation, inhibition, high throughput screening, fragment-based screening, x-ray crystallography . 3.0 ACCOMPLISHMENTS Summary: We

Transcriptional deregulation of homeobox gene ZHX2 in Hodgkin lymphoma.

PubMed

Nagel, Stefan; Schneider, Björn; Meyer, Corinna; Kaufmann, Maren; Drexler, Hans G; Macleod, Roderick A F

2012-05-01

Recently, we identified a novel chromosomal rearrangement in Hodgkin lymphoma (HL), t(4;8)(q27;q24), which targets homeobox gene ZHX2 at the recurrent breakpoint 8q24. This aberration deletes the far upstream region of ZHX2 and results in silenced transcription pinpointing loss of activatory elements. Here, we have looked for potential binding sites within this deleted region to analyze the transcriptional deregulation of this tumor suppressor gene in B-cell malignancies. SiRNA-mediated knockdown and reporter gene analyses identified two transcription factors, homeodomain protein MSX1 and bZIP protein XBP1, directly regulating ZHX2 expression. Furthermore, MSX1-cofactor histone H1C mediated repression of ZHX2 and showed enhanced expression levels in cell line L-1236. As demonstrated by fluorescence in situ hybridization and genomic array analysis, the gene loci of MSX1 at 4p16 and H1C at 6p22 were rearranged in several HL cell lines, correlating with their altered expression activity. The expression of XBP1 was reduced in 6/7 HL cell lines as compared to primary hematopoietic cells. Taken together, our results demonstrate multiple mechanisms decreasing expression of tumor suppressor gene ZHX2 in HL cell lines: loss of enhancing binding sites, reduced expression of activators MSX1 and XBP1, and overexpression of MSX1-corepressor H1C. Moreover, chromosomal deregulations of genes involved in this regulative network highlight their role in development and malignancy of B-cells. Copyright © 2011 Elsevier Ltd. All rights reserved.

Influenza A virus protein PB1-F2 exacerbates IFN-beta expression of human respiratory epithelial cells.

PubMed

Le Goffic, Ronan; Bouguyon, Edwige; Chevalier, Christophe; Vidic, Jasmina; Da Costa, Bruno; Leymarie, Olivier; Bourdieu, Christiane; Decamps, Laure; Dhorne-Pollet, Sophie; Delmas, Bernard

2010-10-15

The PB1-F2 protein of the influenza A virus (IAV) contributes to viral pathogenesis by a mechanism that is not well understood. PB1-F2 was shown to modulate apoptosis and to be targeted by the CD8(+) T cell response. In this study, we examined the downstream effects of PB1-F2 protein during IAV infection by measuring expression of the cellular genes in response to infection with wild-type WSN/33 and PB1-F2 knockout viruses in human lung epithelial cells. Wild-type virus infection resulted in a significant induction of genes involved in innate immunity. Knocking out the PB1-F2 gene strongly decreased the magnitude of expression of cellular genes implicated in antiviral response and MHC class I Ag presentation, suggesting that PB1-F2 exacerbates innate immune response. Biological network analysis revealed the IFN pathway as a link between PB1-F2 and deregulated genes. Using quantitative RT-PCR and IFN-β gene reporter assay, we determined that PB1-F2 mediates an upregulation of IFN-β expression that is dependent on NF-κB but not on AP-1 and IFN regulatory factor-3 transcription factors. Recombinant viruses knocked out for the PB1-F2 and/or the nonstructural viral protein 1 (the viral antagonist of the IFN response) genes provide further evidence that PB1-F2 increases IFN-β expression and that nonstructural viral protein 1 strongly antagonizes the effect of PB1-F2 on the innate response. Finally, we compared the effect of PB1-F2 variants taken from several IAV strains on IFN-β expression and found that PB1-F2-mediated IFN-β induction is significantly influenced by its amino acid sequence, demonstrating its importance in the host cell response triggered by IAV infection.

Ectopic Expression of Homeobox Gene NKX2-1 in Diffuse Large B-Cell Lymphoma Is Mediated by Aberrant Chromatin Modifications

PubMed Central

Nagel, Stefan; Ehrentraut, Stefan; Tomasch, Jürgen; Quentmeier, Hilmar; Meyer, Corinna; Kaufmann, Maren; Drexler, Hans G.; MacLeod, Roderick A. F.

2013-01-01

Homeobox genes encode transcription factors ubiquitously involved in basic developmental processes, deregulation of which promotes cell transformation in multiple cancers including hematopoietic malignancies. In particular, NKL-family homeobox genes TLX1, TLX3 and NKX2-5 are ectopically activated by chromosomal rearrangements in T-cell neoplasias. Here, using transcriptional microarray profiling and RQ-PCR we identified ectopic expression of NKL-family member NKX2-1, in a diffuse large B-cell lymphoma (DLBCL) cell line SU-DHL-5. Moreover, in silico analysis demonstrated NKX2-1 overexpression in 5% of examined DLBCL patient samples. NKX2-1 is physiologically expressed in lung and thyroid tissues where it regulates differentiation. Chromosomal and genomic analyses excluded rearrangements at the NKX2-1 locus in SU-DHL-5, implying alternative activation. Comparative expression profiling implicated several candidate genes in NKX2-1 regulation, variously encoding transcription factors, chromatin modifiers and signaling components. Accordingly, siRNA-mediated knockdown and overexpression studies confirmed involvement of transcription factor HEY1, histone methyltransferase MLL and ubiquitinated histone H2B in NKX2-1 deregulation. Chromosomal aberrations targeting MLL at 11q23 and the histone gene cluster HIST1 at 6p22 which we observed in SU-DHL-5 may, therefore, represent fundamental mutations mediating an aberrant chromatin structure at NKX2-1. Taken together, we identified ectopic expression of NKX2-1 in DLBCL cells, representing the central player in an oncogenic regulative network compromising B-cell differentiation. Thus, our data extend the paradigm of NKL homeobox gene deregulation in lymphoid malignancies. PMID:23637834

Biophysical characterization of fluorotyrosine probes site-specifically incorporated into enzymes: E. coli ribonucleotide reductase as an example

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

Oyala, Paul H.; Ravichandran, Kanchana R.; Funk, Michael A.

Here, fluorinated tyrosines (F nY’s, n = 2 and 3) have been site-specifically incorporated into E. coli class Ia ribonucleotide reductase (RNR) using the recently evolved M. jannaschii Y-tRNA synthetase/tRNA pair. Class Ia RNRs require four redox active Y’s, a stable Y radical (Y·) in the β subunit (position 122 in E. coli), and three transiently oxidized Y’s (356 in β and 731 and 730 in α) to initiate the radicaldependent nucleotide reduction process. F nY (3,5; 2,3; 2,3,5; and 2,3,6) incorporation in place of Y 122-β and the X-ray structures of each resulting β with a diferric cluster aremore » reported and compared with wt-β2 crystallized under the same conditions. The essential diferric-FnY· cofactor is self-assembled from apo F nY-β2, Fe 2+, and O 2 to produce ~1 Y·/β2 and ~3 Fe 3+/β2. The F nY· are stable and active in nucleotide reduction with activities that vary from 5% to 85% that of wt-β2. Each F nY·-β2 has been characterized by 9 and 130 GHz electron paramagnetic resonance and high-field electron nuclear double resonance spectroscopies. The hyperfine interactions associated with the 19F nucleus provide unique signatures of each F nY· that are readily distinguishable from unlabeled Y·’s. The variability of the abiotic F nY pK a’s (6.4 to 7.8) and reduction potentials (-30 to +130 mV relative to Y at pH 7.5) provide probes of enzymatic reactions proposed to involve Y·’s in catalysis and to investigate the importance and identity of hopping Y·’s within redox active proteins proposed to protect them from uncoupled radical chemistry.« less

Biophysical characterization of fluorotyrosine probes site-specifically incorporated into enzymes: E. coli ribonucleotide reductase as an example

DOE PAGES

Oyala, Paul H.; Ravichandran, Kanchana R.; Funk, Michael A.; ...

2016-06-08

Here, fluorinated tyrosines (F nY’s, n = 2 and 3) have been site-specifically incorporated into E. coli class Ia ribonucleotide reductase (RNR) using the recently evolved M. jannaschii Y-tRNA synthetase/tRNA pair. Class Ia RNRs require four redox active Y’s, a stable Y radical (Y·) in the β subunit (position 122 in E. coli), and three transiently oxidized Y’s (356 in β and 731 and 730 in α) to initiate the radicaldependent nucleotide reduction process. F nY (3,5; 2,3; 2,3,5; and 2,3,6) incorporation in place of Y 122-β and the X-ray structures of each resulting β with a diferric cluster aremore » reported and compared with wt-β2 crystallized under the same conditions. The essential diferric-FnY· cofactor is self-assembled from apo F nY-β2, Fe 2+, and O 2 to produce ~1 Y·/β2 and ~3 Fe 3+/β2. The F nY· are stable and active in nucleotide reduction with activities that vary from 5% to 85% that of wt-β2. Each F nY·-β2 has been characterized by 9 and 130 GHz electron paramagnetic resonance and high-field electron nuclear double resonance spectroscopies. The hyperfine interactions associated with the 19F nucleus provide unique signatures of each F nY· that are readily distinguishable from unlabeled Y·’s. The variability of the abiotic F nY pK a’s (6.4 to 7.8) and reduction potentials (-30 to +130 mV relative to Y at pH 7.5) provide probes of enzymatic reactions proposed to involve Y·’s in catalysis and to investigate the importance and identity of hopping Y·’s within redox active proteins proposed to protect them from uncoupled radical chemistry.« less

Ionic liquid mediated synthesis and molecular docking study of novel aromatic embedded Schiff bases as potent cholinesterase inhibitors.

PubMed

Abd Razik, Basma M; Osman, Hasnah; Basiri, Alireza; Salhin, Abdussalam; Kia, Yalda; Ezzat, Mohammed Oday; Murugaiyah, Vikneswaran

2014-12-01

Novel aromatic embedded Schiff bases have been synthesized in ionic liquid [bmim]Br and evaluated in vitro for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes inhibitory activities. Among the newly synthesized compounds, 5f, 5h and 7j displayed higher AChE enzyme inhibitory activities than standard drug, galanthamine, with IC50 values of 1.88, 2.05 and 2.03μM, respectively. Interestingly, all the compounds except for compound 5c displayed higher BChE inhibitories than standard with IC50 values ranging from 3.49 to 19.86μM. Molecular docking analysis for 5f and 7j possessing the most potent AChE and BChE inhibitory activities, disclosed their binding interaction templates to the active site of AChE and BChE enzymes, respectively. Copyright © 2014 Elsevier Inc. All rights reserved.

Fe(III) and Fe(II) ions different effects on Enterococcus hirae cell growth and membrane-associated ATPase activity

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

Vardanyan, Zaruhi; Trchounian, Armen, E-mail: trchounian@ysu.am

2012-01-06

Highlights: Black-Right-Pointing-Pointer Fe{sup 3+} stimulates but Fe{sup 2+} suppresses Enterococcus hirae wild-type and atpD mutant growth. Black-Right-Pointing-Pointer Fe ions change oxidation-reduction potential drop during cell growth. Black-Right-Pointing-Pointer Fe{sup 3+} and Fe{sup 2+} have opposite effects on a membrane-associated ATPase activity. Black-Right-Pointing-Pointer These effects are either in the presence of F{sub 0}F{sub 1} inhibitor or non-functional F{sub 0}F{sub 1}. Black-Right-Pointing-Pointer Fe ions decrease protons and coupled potassium ions fluxes across the membrane. -- Abstract: Enterococcus hirae is able to grow under anaerobic conditions during glucose fermentation (pH 8.0) which is accompanied by acidification of the medium and drop in its oxidation-reductionmore » potential (E{sub h}) from positive values to negative ones (down to {approx}-200 mV). In this study, iron (III) ions (Fe{sup 3+}) have been shown to affect bacterial growth in a concentration-dependent manner (within the range of 0.05-2 mM) by decreasing lag phase duration and increasing specific growth rate. While iron(II) ions (Fe{sup 2+}) had opposite effects which were reflected by suppressing bacterial growth. These ions also affected the changes in E{sub h} values during bacterial growth. It was revealed that ATPase activity with and without N,N Prime -dicyclohexylcarbodiimide (DCCD), an inhibitor of the F{sub 0}F{sub 1}-ATPase, increased in the presence of even low Fe{sup 3+} concentration (0.05 mM) but decreased in the presence of Fe{sup 2+}. It was established that Fe{sup 3+} and Fe{sup 2+} both significantly inhibited the proton-potassium exchange of bacteria, but stronger effects were in the case of Fe{sup 2+} with DCCD. Such results were observed with both wild-type ATCC9790 and atpD mutant (with defective F{sub 0}F{sub 1}) MS116 strains but they were different with Fe{sup 3+} and Fe{sup 2+}. It is suggested that the effects of Fe{sup 3+} might be due to interaction of these ions with F{sub 0}F{sub 1} or there might be a Fe{sup 3+}-dependent ATPase different from F{sub 0}F{sub 1} in these bacteria that is active even in the presence of DCCD. Fe{sup 2+} inhibits E. hirae cell growth probably by strong effect on E{sub h} leading to changes in F{sub 0}F{sub 1} and decreasing its activity.« less

Mutations in PIK3CA are infrequent in neuroblastoma

PubMed Central

Dam, Vincent; Morgan, Brian T; Mazanek, Pavel; Hogarty, Michael D

2006-01-01

Background Neuroblastoma is a frequently lethal pediatric cancer in which MYCN genomic amplification is highly correlated with aggressive disease. Deregulated MYC genes require co-operative lesions to foster tumourigenesis and both direct and indirect evidence support activated Ras signaling for this purpose in many cancers. Yet Ras genes and Braf, while often activated in cancer cells, are infrequent targets for activation in neuroblastoma. Recently, the Ras effector PIK3CA was shown to be activated in diverse human cancers. We therefore assessed PIK3CA for mutation in human neuroblastomas, as well as in neuroblastomas arising in transgenic mice with MYCN overexpressed in neural-crest tissues. In this murine model we additionally surveyed for Ras family and Braf mutations as these have not been previously reported. Methods Sixty-nine human neuroblastomas (42 primary tumors and 27 cell lines) were sequenced for PIK3CA activating mutations within the C2, helical and kinase domain "hot spots" where 80% of mutations cluster. Constitutional DNA was sequenced in cases with confirmed alterations to assess for germline or somatic acquisition. Additionally, Ras family members (Hras1, Kras2 and Nras) and the downstream effectors Pik3ca and Braf, were sequenced from twenty-five neuroblastomas arising in neuroblastoma-prone transgenic mice. Results We identified mutations in the PIK3CA gene in 2 of 69 human neuroblastomas (2.9%). Neither mutation (R524M and E982D) has been studied to date for effects on lipid kinase activity. Though both occurred in tumors with MYCN amplification the overall rate of PIK3CA mutations in MYCN amplified and single-copy tumors did not differ appreciably (2 of 31 versus 0 of 38, respectively). Further, no activating mutations were identified in a survey of Ras signal transduction genes (including Hras1, Kras2, Nras, Pik3ca, or Braf genes) in twenty-five neuroblastic tumors arising in the MYCN-initiated transgenic mouse model. Conclusion These data suggest that activating mutations in the Ras/Raf-MAPK/PI3K signaling cascades occur infrequently in neuroblastoma. Further, despite compelling evidence for MYC and RAS cooperation in vitro and in vivo to promote tumourigenesis, activation of RAS signal transduction does not constitute a preferred secondary pathway in neuroblastomas with MYCN deregulation in either human tumors or murine models. PMID:16822308

E-box-independent regulation of transcription and differentiation by MYC.

PubMed

Uribesalgo, Iris; Buschbeck, Marcus; Gutiérrez, Arantxa; Teichmann, Sophia; Demajo, Santiago; Kuebler, Bernd; Nomdedéu, Josep F; Martín-Caballero, Juan; Roma, Guglielmo; Benitah, Salvador Aznar; Di Croce, Luciano

2011-10-23

MYC proto-oncogene is a key player in cell homeostasis that is commonly deregulated in human carcinogenesis(1). MYC can either activate or repress target genes by forming a complex with MAX (ref. 2). MYC also exerts MAX-independent functions that are not yet fully characterized(3). Cells possess an intrinsic pathway that can abrogate MYC-MAX dimerization and E-box interaction, by inducing phosphorylation of MYC in a PAK2-dependent manner at three residues located in its helix-loop-helix domain(4). Here we show that these carboxy-terminal phosphorylation events switch MYC from an oncogenic to a tumour-suppressive function. In undifferentiated cells, MYC-MAX is targeted to the promoters of retinoic-acid-responsive genes by its direct interaction with the retinoic acid receptor-α (RARα). MYC-MAX cooperates with RARα to repress genes required for differentiation, in an E-box-independent manner. Conversely, on C-terminal phosphorylation of MYC during differentiation, the complex switches from a repressive to an activating function, by releasing MAX and recruiting transcriptional co-activators. Phospho-MYC synergizes with retinoic acid to eliminate circulating leukaemic cells and to decrease the level of tumour invasion. Our results identify an E-box-independent mechanism for transcriptional regulation by MYC that unveils previously unknown functions for MYC in differentiation. These may be exploited to develop alternative targeted therapies.

New tactics and technologies to meet the competitive utility environment

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

Audin, L.

A new age is dawning for lower-cost energy use and supply. The deregulation of the electric industry is creating new pricing options that will change how one evaluates cost-cutting energy alternatives. As competition begins, smart users will grasp these opportunities and press for greater innovation on the part of marketers. Energy users can best navigate these choices by: understanding the concepts inherent in deregulation (such as transmission constrains); influencing the deregulation process (which does not end when markets first open); learning to use new analytical tools (such as load profile analysis); applying new technologies (e.g., wireless automatic metering); and beingmore » as creative as possible (because marketers won`t be).« less

Luminescence characteristics of Dy3+ activated Na 2Sr 2Mg (BO 3)2F 2: Dy 3+ phosphor

NASA Astrophysics Data System (ADS)

Wani, Javaid A.; Dhoble, N. S.; Dhoble, S. J.

2012-11-01

In this paper, we have reported a new Na 2Sr 2Mg (BO 3)2F 2:Dy 3+ thermoluminescence (TL) phosphor prepared via the wet chemical method. Prepared phosphor was characterized by X-ray powder diffraction, photoluminescence (PL), TL and scanning electronmicroscopy techniques. The scanning electronmicroscopic image of Na 2Sr 2Mg (BO 3)2F 2:Dy 3+ phosphor confirms the micron size of particles. Under the PL study, the characteristic emission spectrum of Dy 3+ corresponding to 4F 9/2→6H 15/2 (481 nm) and 4F 9/2→6H 13/2 (576 nm) transitions was observed. The TL property of the as prepared phosphor was also found to be good. TL intensity of Na 2Sr2Mg(BO 3)F 2:Dy 3+ phosphors at 0.99 kGy exposure of γ-irradiations was compared with standard CaSO 4:Dy phosphor. It was seen that TL intensity of Na 2Sr 2Mg (BO 3)2F 2: Dy 3+ phosphors is 1.1 times less compared with the standard CaSO 4:Dy TL dosimeter phosphor. The kinetic parameters are also discussed in detail. The values of activation energy E (eV) and frequency factor S (s -1) were found to be 0.57 eV and 1.25×106 s-1, respectively.

The mTORC1-4E-BP-eIF4E axis controls de novo Bcl6 protein synthesis in T cells and systemic autoimmunity.

PubMed

Yi, Woelsung; Gupta, Sanjay; Ricker, Edd; Manni, Michela; Jessberger, Rolf; Chinenov, Yurii; Molina, Henrik; Pernis, Alessandra B

2017-08-15

Post-transcriptional modifications can control protein abundance, but the extent to which these alterations contribute to the expression of T helper (T H ) lineage-defining factors is unknown. Tight regulation of Bcl6 expression, an essential transcription factor for T follicular helper (T FH ) cells, is critical as aberrant T FH cell expansion is associated with autoimmune diseases, such as systemic lupus erythematosus (SLE). Here we show that lack of the SLE risk variant Def6 results in deregulation of Bcl6 protein synthesis in T cells as a result of enhanced activation of the mTORC1-4E-BP-eIF4E axis, secondary to aberrant assembly of a raptor-p62-TRAF6 complex. Proteomic analysis reveals that this pathway selectively controls the abundance of a subset of proteins. Rapamycin or raptor deletion ameliorates the aberrant T FH cell expansion in mice lacking Def6. Thus deregulation of mTORC1-dependent pathways controlling protein synthesis can result in T-cell dysfunction, indicating a mechanism by which mTORC1 can promote autoimmunity.Excessive expansion of the T follicular helper (T FH ) cell pool is associated with autoimmune disease and Def6 has been identified as an SLE risk variant. Here the authors show that Def6 limits proliferation of T FH cells in mice via alteration of mTORC1 signaling and inhibition of Bcl6 expression.

Serum MicroRNAs as Potential Biomarkers for Early Diagnosis of Hepatitis C Virus-Related Hepatocellular Carcinoma in Egyptian Patients

PubMed Central

Motawi, Tarek K.; Shaker, Olfat G.; El-Maraghy, Shohda A.; Senousy, Mahmoud A.

2015-01-01

Circulating microRNAs are deregulated in liver fibrosis and hepatocellular carcinoma (HCC) and are candidate biomarkers. This study investigated the potential of serum microRNAs; miR-19a, miR-296, miR-130a, miR-195, miR-192, miR-34a, and miR-146a as early diagnostic biomarkers for hepatitis C virus (HCV)-related HCC. As how these microRNAs change during liver fibrosis progression is not clear, we explored their serum levels during fibrosis progression in HCV-associated chronic liver disease (CLD) and if they could serve as non-invasive biomarkers for fibrosis progression to HCC. 112 Egyptian HCV-HCC patients, 125 non-malignant HCV-CLD patients, and 42 healthy controls were included. CLD patients were subdivided according to Metavir fibrosis-scoring. Serum microRNAs were measured by qRT-PCR custom array. Serum microRNAs were deregulated in HCC versus controls, and except miR-130a, they were differentially expressed between HCC and CLD or late fibrosis (F3-F4) subgroup. Serum microRNAs were not significantly different between individual fibrosis-stages or between F1-F2 (early/moderate fibrosis) and F3-F4. Only miR-19a was significantly downregulated from liver fibrosis (F1-F3) to cirrhosis (F4) to HCC. Individual microRNAs discriminated HCC from controls, and except miR-130a, they distinguished HCC from CLD or F3-F4 patients by receiver-operating-characteristic analysis. Multivariate logistic analysis revealed a panel of four microRNAs (miR-19a, miR-195, miR-192, and miR-146a) with high diagnostic accuracy for HCC (AUC = 0.946). The microRNA panel also discriminated HCC from controls (AUC = 0.949), CLD (AUC = 0.945), and F3-F4 (AUC = 0.955). Studied microRNAs were positively correlated in HCC group. miR-19a and miR-34a were correlated with portal vein thrombosis and HCC staging scores, respectively. In conclusion, studied microRNAs, but not miR-130a, could serve as potential early biomarkers for HCC in high-risk groups, with miR-19a as a biomarker for liver fibrosis progression to cirrhosis to HCC. We identified a panel of four serum microRNAs with high accuracy in HCC diagnosis. Additional studies are required to confirm this panel and test its prognostic significance. PMID:26352740

Autoinhibition of a calmodulin-dependent calcium pump involves a structure in the stalk that connects the transmembrane domain to the ATPase catalytic domain

NASA Technical Reports Server (NTRS)

Curran, A. C.; Hwang, I.; Corbin, J.; Martinez, S.; Rayle, D.; Sze, H.; Harper, J. F.; Evans, M. L. (Principal Investigator)

2000-01-01

The regulation of Ca(2+)-pumps is important for controlling [Ca(2+)] in the cytosol and organelles of all eukaryotes. Here, we report a genetic strategy to identify residues that function in autoinhibition of a novel calmodulin-activated Ca(2+)-pump with an N-terminal regulatory domain (isoform ACA2 from Arabidopsis). Mutant pumps with constitutive activity were identified by complementation of a yeast (K616) deficient in two Ca(2+)-pumps. Fifteen mutations were found that disrupted a segment of the N-terminal autoinhibitor located between Lys(23) and Arg(54). Three mutations (E167K, D219N, and E341K) were found associated with the stalk that connects the ATPase catalytic domain (head) and with the transmembrane domain. Enzyme assays indicated that the stalk mutations resulted in calmodulin-independent activity, with V(max), K(mATP), and K(mCa(2+)) similar to that of a pump in which the N-terminal autoinhibitor had been deleted. A highly conservative substitution at Asp(219) (D219E) still produced a deregulated pump, indicating that the autoinhibitory structure in the stalk is highly sensitive to perturbation. In plasma membrane H(+)-ATPases from yeast and plants, similarly positioned mutations resulted in hyperactive pumps. Together, these results suggest that a structural feature of the stalk is of general importance in regulating diverse P-type ATPases.

Human papilloma virus type16 E6 deregulates CHK1 and sensitizes human fibroblasts to environmental carcinogens independently of its effect on p53

PubMed Central

Chen, Bo; Simpson, Dennis A.; Zhou, Yingchun; Mitra, Amritava; Mitchell, David L.; Cordeiro-Stone, Marila; Kaufmann, William K.

2015-01-01

After treatment with ultraviolet radiation (UV), human fibroblasts that express the HPV type 16 E6 oncoprotein display defects in repair of cyclobutane pyrimidine dimers, hypersensitivity to inactivation of clonogenic survival and an inability to sustain DNA replication. To determine whether these effects are specific to depletion of p53 or inactivation of its function, fibroblast lines were constructed with ectopic expression of a dominant-negative p53 allele (p53-H179Q) to inactivate function or a short-hairpin RNA (p53-RNAi) to deplete expression of p53. Only the expression of HPV16E6 sensitized fibroblasts to UV or the chemical carcinogen, benzo[a]pyrene diolepoxide I (BPDE). Carcinogen-treated cells expressing p53-H179Q or p53-RNAi were resistant to inactivation of colony formation and did not suffer replication arrest. CHK1 is a key checkpoint kinase in the response to carcinogen-induced DNA damage. Control and p53-RNAi-expressing fibroblasts displayed phosphorylation of Ser345 on CHK1 45–120 min after carcinogen treatment with a return to near baseline phosphorylation by 6 h after treatment. HPV16E6-expressing fibroblasts displayed enhanced and sustained phosphorylation of CHK1. This was associated with enhanced phosphorylation of Thr68 on CHK2 and Ser139 on H2AX, both markers of severe replication stress and DNA double strand breaks. Incubation with the phosphatase inhibitor okadaic acid produced more phosphorylation of CHK1 in UV-treated HPV16E6-expressing cells than in p53-H179Q-expressing cells suggesting that HPV16E6 may interfere with the recovery of coupled DNA replication at replication forks that are stalled at [6-4]pyrimidine-pyrimidone photoproducts and BPDE-DNA adducts. The results indicate that HPV16E6 targets a protein or proteins other than p53 to deregulate the activity of CHK1 in carcinogen-damaged cells. PMID:19411857

Dynamic analysis of the combinatorial regulation involving transcription factors and microRNAs in cell fate decisions.

PubMed

Yan, Fang; Liu, Haihong; Liu, Zengrong

2014-01-01

P53 and E2F1 are critical transcription factors involved in the choices between different cell fates including cell differentiation, cell cycle arrest or apoptosis. Recent experiments have shown that two families of microRNAs (miRNAs), p53-responsive miR34 (miRNA-34 a, b and c) and E2F1-inducible miR449 (miRNA-449 a, b and c) are potent inducers of these different fates and might have an important role in sensitizing cancer cells to drug treatment and tumor suppression. Identifying the mechanisms responsible for the combinatorial regulatory roles of these two transcription factors and two miRNAs is an important and challenging problem. Here, based in part on the model proposed in Tongli Zhang et al. (2007), we developed a mathematical model of the decision process and explored the combinatorial regulation between these two transcription factors and two miRNAs in response to DNA damage. By analyzing nonlinear dynamic behaviors of the model, we found that p53 exhibits pulsatile behavior. Moreover, a comparison is given to reveal the subtle differences of the cell fate decision process between regulation and deregulation of miR34 on E2F1. It predicts that miR34 plays a critical role in promoting cell cycle arrest. In addition, a computer simulation result also predicts that the miR449 is necessary for apoptosis in response to sustained DNA damage. In agreement with experimental observations, our model can account for the intricate regulatory relationship between these two transcription factors and two miRNAs in the cell fate decision process after DNA damage. These theoretical results indicate that miR34 and miR449 are effective tumor suppressors and play critical roles in cell fate decisions. The work provides a dynamic mechanism that shows how cell fate decisions are coordinated by two transcription factors and two miRNAs. This article is part of a Special Issue entitled: Computational Proteomics, Systems Biology and Clinical Implications. Guest Editor: Yudong Cai. Crown Copyright © 2013. All rights reserved.

MiR-34a-3p alters proliferation and apoptosis of meningioma cells in vitro and is directly targeting SMAD4, FRAT1 and BCL2

PubMed Central

Werner, Tamara V.; Hart, Martin; Nickels, Ruth; Kim, Yoo-Jin; Menger, Michael D.; Bohle, Rainer M.; Keller, Andreas; Ludwig, Nicole; Meese, Eckart

2017-01-01

Micro (mi)RNAs are short, noncoding RNAs and deregulation of miRNAs and their targets are implicated in tumor generation and progression in many cancers. Meningiomas are mostly benign, slow growing tumors of the central nervous system with a small percentage showing a malignant phenotype. Following in silico prediction of potential targets of miR-34a-3p, SMAD4, FRAT1, and BCL2 have been confirmed as targets by dual luciferase assays with co-expression of miR-34a-3p and reporter gene constructs containing the respective 3'UTRs. Disruption of the miR-34a-3p binding sites in the 3'UTRs resulted in loss of responsiveness to miR-34a-3p overexpression. In meningioma cells, overexpression of miR-34a-3p resulted in decreased protein levels of SMAD4, FRAT1 and BCL2, while inhibition of miR-34a-3p led to increased levels of these proteins as confirmed by Western blotting. Furthermore, deregulation of miR-34a-3p altered cell proliferation and apoptosis of meningioma cells in vitro. We show that SMAD4, FRAT1 and BCL2 are direct targets of miR-34a-3p and that deregulation of miR-34a-3p alters proliferation and apoptosis of meningioma cells in vitro. As part of their respective signaling pathways, which are known to play a role in meningioma genesis and progression, deregulation of SMAD4, FRAT1 and BCL2 might contribute to the aberrant activation of these signaling pathways leading to increased proliferation and inhibition of apoptosis in meningiomas. PMID:28340489

MiR-34a-3p alters proliferation and apoptosis of meningioma cells in vitro and is directly targeting SMAD4, FRAT1 and BCL2.

PubMed

Werner, Tamara V; Hart, Martin; Nickels, Ruth; Kim, Yoo-Jin; Menger, Michael D; Bohle, Rainer M; Keller, Andreas; Ludwig, Nicole; Meese, Eckart

2017-03-23

Micro (mi)RNAs are short, noncoding RNAs and deregulation of miRNAs and their targets are implicated in tumor generation and progression in many cancers. Meningiomas are mostly benign, slow growing tumors of the central nervous system with a small percentage showing a malignant phenotype.Following in silico prediction of potential targets of miR-34a-3p, SMAD4 , FRAT1 , and BCL2 have been confirmed as targets by dual luciferase assays with co-expression of miR-34a-3p and reporter gene constructs containing the respective 3'UTRs. Disruption of the miR-34a-3p binding sites in the 3'UTRs resulted in loss of responsiveness to miR-34a-3p overexpression. In meningioma cells, overexpression of miR-34a-3p resulted in decreased protein levels of SMAD4, FRAT1 and BCL2, while inhibition of miR-34a-3p led to increased levels of these proteins as confirmed by Western blotting. Furthermore, deregulation of miR-34a-3p altered cell proliferation and apoptosis of meningioma cells in vitro .We show that SMAD4 , FRAT1 and BCL2 are direct targets of miR-34a-3p and that deregulation of miR-34a-3p alters proliferation and apoptosis of meningioma cells in vitro . As part of their respective signaling pathways, which are known to play a role in meningioma genesis and progression, deregulation of SMAD4 , FRAT1 and BCL2 might contribute to the aberrant activation of these signaling pathways leading to increased proliferation and inhibition of apoptosis in meningiomas.

Transcription factors ETF, E2F, and SP-1 are involved in cytokine-independent proliferation of murine hepatocytes.

PubMed

Zellmer, Sebastian; Schmidt-Heck, Wolfgang; Godoy, Patricio; Weng, Honglei; Meyer, Christoph; Lehmann, Thomas; Sparna, Titus; Schormann, Wiebke; Hammad, Seddik; Kreutz, Clemens; Timmer, Jens; von Weizsäcker, Fritz; Thürmann, Petra A; Merfort, Irmgard; Guthke, Reinhard; Dooley, Steven; Hengstler, Jan G; Gebhardt, Rolf

2010-12-01

The cellular basis of liver regeneration has been intensely investigated for many years. However, the mechanisms initiating hepatocyte "plasticity" and priming for proliferation are not yet fully clear. We investigated alterations in gene expression patterns during the first 72 hours of C57BL/6N mouse hepatocyte culture on collagen monolayers (CM), which display a high basal frequency of proliferation in the absence of cytokines. Although many metabolic genes were down-regulated, genes related to mitogen-activated protein kinase (MAPK) signaling and cell cycle were up-regulated. The latter genes showed an overrepresentation of transcription factor binding sites (TFBS) for ETF (TEA domain family member 2), E2F1 (E2F transcription factor 1), and SP-1 (Sp1 transcription factor) (P < 0.001), all depending on MAPK signaling. Time-dependent increase of ERK1/2 phosphorylation occurred during the first 48 hours (and beyond) in the absence of cytokines, accompanied by an enhanced bromodeoxyuridine labeling index of 20%. The MEK inhibitor PD98059 blunted these effects indicating MAPK signaling as major trigger for this cytokine-independent proliferative response. In line with these in vitro findings, liver tissue of mice challenged with CCl(4) displayed hepatocytes with intense p-ERK1/2 staining and nuclear SP-1 and E2F1 expression. Furthermore, differentially expressed genes in mice after partial hepatectomy contained overrepresented TFBS for ETF, E2F1, and SP-1 and displayed increased expression of E2F1. Cultivation of murine hepatocytes on CM primes cells for proliferation through cytokine-independent activation of MAPK signaling. The transcription factors ETF, E2F1, and SP-1 seem to play a pronounced role in mediating proliferation-dependent differential gene expression. Similar events, but on a shorter time-scale, occur very early after liver damage in vivo. Copyright © 2010 American Association for the Study of Liver Diseases.

Copper-induced deregulation of microRNA expression in the zebrafish olfactory system

PubMed Central

Wang, Lu; Bammler, Theo K.; Beyer, Richard P.; Gallagher, Evan P.

2016-01-01

Although environmental trace metals, such as copper (Cu), can disrupt normal olfactory function in fish, the underlying molecular mechanisms of metal-induced olfactory injury have not been elucidated. Current research has suggested the involvement of epigenetic modifications. To address this hypothesis, we analyzed microRNA (miRNA) profiles in the olfactory system of Cu-exposed zebrafish. Our data revealed 2, 10, and 28 differentially expressed miRNAs in a dose-response manner corresponding to three increasing Cu concentrations. Numerous deregulated miRNAs were involved in neurogenesis (e.g. let-7, miR-7a, miR-128 and miR-138), indicating a role for Cu-mediated toxicity via interference with neurogenesis processes. Putative gene targets of deregulated miRNAs were identified when interrogating our previously published microarray database, including those involved in cell growth and proliferation, cell death, and cell morphology. Moreover, several miRNAs (e.g. miR-203a, miR-199*, miR-16a, miR-16c, and miR-25) may contribute to decreased mRNA levels of their host genes involved in olfactory signal transduction pathways and other critical neurological processes via a post-transcriptional mechanism. Our findings provide novel insight into the epigenetic regulatory mechanisms of metal-induced neurotoxicity of the fish olfactory system, and identify novel miRNA biomarkers of metal exposures. PMID:23745839

Binding of 2-[18F]fluoro-CP-118,954 to mouse acetylcholinesterase: microPET and ex vivo Cerenkov luminescence imaging studies.

PubMed

Kim, Dong Hyun; Choe, Yearn Seong; Choi, Joon Young; Lee, Kyung-Han; Kim, Byung-Tae

2011-05-01

Acetylcholinesterase (AChE) has been an important cholinergic factor for the diagnosis of Alzheimer's disease (AD), because of reduced AChE activity in the postmortem brains of AD patients. We previously developed 5,7-dihydro-3-(2-(1-(2-[(18)F]fluorobenzyl)-4-piperidinyl)ethyl)-6H-pyrrolo(3,2,f)-1,2-benzisoxazol-6-one (2-[(18)F]fluoro-CP-118,954) for in vivo studies of AChE in mice. In the present study, we automated the synthesis of 2-[(18)F]fluoro-CP-118,954 for the routine use and evaluated the radioligand by microPET and ex vivo Cerenkov luminescence imaging of mouse AChE. 4-[(18)F]Fluoro-donepezil, another AChE inhibitor, was used for comparison. Automated syntheses of 2-[(18)F]fluoro-CP-118,954 and 4-[(18)F]fluoro-donepezil resulted in high radiochemical yields (25-33% and 30-40%) and high specific activity (27.1-35.4 and 29.7-37.3 GBq/μmol). Brain microPET images of two ICR mice injected with 2-[(18)F]fluoro-CP-118,954 demonstrated high uptake in the striatum (ROI analysis: 5.1 %ID/g for the first 30 min and 4.1 %ID/g for another 30 min), and a blocking study with injection of CP-118,954 into one of the mice at 30 min after radioligand injection led to complete blocking of radioligand uptake in the striatum (ROI analysis: 1.9 %ID/g), whereas (18)F-labeled donepezil did not show specific uptake in the striatum. In another set of experiments, the brain tissues (striatum, parietal cortex, frontal cortex and cerebellum) were excised after brain microPET/CT imaging of mouse injected with 2-[(18)F]fluoro-CP-118,954, and a high striatal uptake was also detected in ex vivo optical and microPET images (ROI analysis: 1.4 %ID/g) and in γ-counting data (2.1 %ID/g at 50 min post-injection) of the brain tissues. Taken together, these results demonstrated that 2-[(18)F]fluoro-CP-118,954 specifically binds to AChE in mouse brains. Copyright © 2011 Elsevier Inc. All rights reserved.

E6/E7-P53-POU2F1-CTHRC1 axis promotes cervical cancer metastasis and activates Wnt/PCP pathway

PubMed Central

Zhang, Rong; Lu, Huan; Lyu, Yuan-yuan; Yang, Xiao-mei; Zhu, Lin-yan; Yang, Guang-dong; Jiang, Peng-cheng; Re, Yuan; Song, Wei-wei; Wang, Jin-hao; Zhang, Can-can; Gu, Fei; Luo, Tian-jiao; Wu, Zhi-yong; Xu, Cong-jian

2017-01-01

Cervical cancer is an infectious cancer and the most common gynecologic cancer worldwide. E6/E7, the early genes of the high-risk mucosal human papillomavirus type, play key roles in the carcinogenic process of cervical cancer. However, little was known about its roles in modulating tumor microenvironment, particular extracellular matrix (ECM). In this study, we found that E6/E7 could regulate multiple ECM proteins, especially collagen triple helix repeat containing 1 (CTHRC1). CTHRC1 is highly expressed in cervical cancer tissue and serum and closely correlated with clinicopathological parameters. CTHRC1 promotes cervical cancer cell migration and invasion in vitro and metastasis in vivo. E6/E7 regulates the expression of CTHRC1 in cervical cancer by E6/E7-p53-POU2F1 (POU class 2 homeobox 1) axis. Futhermore, CTHRC1 activates Wnt/PCP signaling pathway. Take together, E6/E7-p53-POU2F1-CTHRC1 axis promotes cervical cancer cell invasion and metastasis and may act as a potential therapeutic target for interventions against cervical cancer invasion and metastasis. PMID:28303973

Inhibition of Retinoblastoma Protein Inactivation

DTIC Science & Technology

2016-09-01

Retinoblastoma protein, E2F transcription factor, high throughput screen, drug discovery, x-ray crystallography 16. SECURITY CLASSIFICATION OF: 17...developed a method to perform fragment based screening by x-ray crystallography . 2.0 KEYWORDS Retinoblastoma (Rb) pathway, E2F transcription factor...cancer, cell-cycle inhibition, activation, modulation, inhibition, high throughput screening, fragment-based screening, x-ray crystallography

The broadly neutralizing anti-human immunodeficiency virus type 1 4E10 monoclonal antibody is better adapted to membrane-bound epitope recognition and blocking than 2F5.

PubMed

Huarte, Nerea; Lorizate, Maier; Maeso, Rubén; Kunert, Renate; Arranz, Rocio; Valpuesta, José M; Nieva, José L

2008-09-01

The broadly neutralizing 2F5 and 4E10 monoclonal antibodies (MAbs) recognize epitopes within the membrane-proximal external region (MPER) that connects the human immunodeficiency virus type 1 (HIV-1) envelope gp41 ectodomain with the transmembrane anchor. By adopting different conformations that stably insert into the virion external membrane interface, such as helical structures, a conserved aromatic-rich sequence within the MPER is thought to participate in HIV-1-cell fusion. Recent experimental evidence suggests that the neutralizing activity of 2F5 and 4E10 might correlate with the MAbs' capacity to recognize epitopes inserted into the viral membrane, thereby impairing MPER fusogenic activity. To gain new insights into the molecular mechanism underlying viral neutralization by these antibodies, we have compared the capacities of 2F5 and 4E10 to block the membrane-disorganizing activity of MPER peptides inserted into the surface bilayer of solution-diffusing unilamellar vesicles. Both MAbs inhibited leakage of vesicular aqueous contents (membrane permeabilization) and intervesicular lipid mixing (membrane fusion) promoted by MPER-derived peptides. Thus, our data support the idea that antibody binding to a membrane-inserted epitope may interfere with the function of the MPER during gp41-induced fusion. Antibody insertion into a cholesterol-containing, uncharged virion-like membrane is mediated by specific epitope recognition, and moreover, partitioning-coupled folding into a helix reduces the efficiency of 2F5 MAb binding to its epitope in the membrane. We conclude that the capacity to interfere with the membrane activity of conserved MPER sequences is best correlated with the broad neutralization of the 4E10 MAb.

The variability and IRI2007-predictability of hmF2 over South Africa

NASA Astrophysics Data System (ADS)

Mbambo, M. C.; McKinnell, Lee-Anne; Habarulema, J. B.

2013-11-01

This paper presents an investigation into the variability and predictability of the maximum height of the ionospheric F2 layer, hmF2 over the South African region. Data from three South African stations, namely Madimbo (22.4°S, 26.5°E, dip angle: -61.47°), Grahamstown (33.3°S, 26.5°E, dip angle: -64.08°) and Louisvale (28.5°S, 21.2°E, dip angle: -65.44°) were used in this study. The results indicate that hmF2 shows a larger variability around midnight than during the daytime for all seasons. Monthly median hmF2 values were used in all cases and were compared with predictions from the IRI-2007 model, using the URSI (Union Radio-Scientifique Internationale) coefficient option. The analysis covers the diurnal and seasonal hourly hmF2 values for the selected months and time sectors e.g. January, July, April and October for 2003 and 2005. The time ranges between (03h00-23h00 UT; LT = UT + 2h) representing the local sunrise, midday, sunset and midnight hours. The time covers sunrise, midday, sunrise, and midnight hours (03-06h00 UT, 07-11h00 UT, sunrise 16-18h00 UT and 22-23h00 UT; LT = UT + 2h). The dependence of the results on solar activity levels was also investigated. The IRI-2007 predictions follow fairly well the diurnal and seasonal variation patterns of the observed hmF2 values at all the stations. However, the IRI-2007 model overestimates and underestimates the hmF2 value during different months for all the solar activity periods.

YB-1, the E2F Pathway, and Regulation of Tumor Cell Growth

PubMed Central

Samuel, Weini; Cao, Helen; Patel, Rachna; Mehta, Reena; Stern, J. Lewis; Reid, Glen; Woolley, Adele G.; Miller, Lance D.; Black, Michael A; Shelling, Andrew N.; Print, Cristin G.; Braithwaite, Antony W.

2012-01-01

Background Y-box binding factor 1 (YB-1) has been associated with prognosis in many tumor types. Reduced YB-1 expression inhibits tumor cell growth, but the mechanism is unclear. Methods YB-1 mRNA levels were compared with tumor grade and histology using microarray data from 771 breast cancer patients and with disease-free survival and distant metastasis–free survival using data from 375 of those patients who did not receive adjuvant therapy. Microarrays were further searched for genes that had correlated expression with YB-1 mRNA. Small interfering RNA (siRNA) was used to study the effects of reduced YB-1 expression on growth of three tumor cell lines (MCF-7 breast, HCT116 colon, and A549 lung cancer cells), on tumorigenesis by A549 cells in nude mice, and on global transcription in the three cancer cell lines. Reporter gene assays were used to determine whether YB-1 siRNAs affected the expression of E2F1, and chromatin immunoprecipitation was used to determine whether YB-1 bound to various E2F promoters as well as E2F1-regulated promoters. All P values were from two-sided tests. Results YB-1 levels were elevated in more aggressive tumors and were strongly associated with poor disease-free survival and distant metastasis–free survival. YB-1 expression was often associated with the expression of genes with E2F sites in their promoters. Cells expressing YB-1 siRNA grew substantially more slowly than control cells and formed tumors less readily in nude mice. Transcripts that were altered in cancer cell lines with YB-1 siRNA included 32 genes that are components of prognostic gene expression signatures. YB-1 regulated expression of an E2F1 promoter–reporter construct in A549 cells (eg, relative E2F1 promoter activity with control siRNA = 4.04; with YB-1 siRNA = 1.40, difference= −2.64, 95% confidence interval = −3.57 to −1.71, P < .001) and bound to the promoters of several well-defined E2F1 target genes. Conclusion YB-1 expression is associated with the activity of E2F transcription factors and may control tumor cell growth by this mechanism. PMID:22205655

Differential antioxidant defense and detoxification mechanisms in photodynamically stressed rice plants treated with the deregulators of porphyrin biosynthesis, 5-aminolevulinic acid and oxyfluorfen.

PubMed

Phung, Thu-Ha; Jung, Sunyo

2015-04-03

This study focuses on differential molecular mechanisms of antioxidant and detoxification systems in rice plants under two different types of photodynamic stress imposed by porphyrin deregulators, 5-aminolevulinic acid (ALA) and oxyfluorfen (OF). The ALA-treated plants with white necrosis exhibited a greater decrease in photochemical quantum efficiency, Fv/Fm, as well as a greater increase in activity of superoxide dismutase, compared to the OF-treated plants. By contrast, the brown necrosis in OF-treated plants resulted in not only more widely dispersed H2O2 production and greater increases in H2O2-decomposing enzymes, catalase and peroxidase, but also lower ascorbate redox state. In addition, ALA- and OF-treated plants markedly up-regulated transcript levels of genes involved in detoxification processes including transport and movement, cellular homeostasis, and xenobiotic conjugation, with prominent up-regulation of serine/threonine kinase and chaperone only in ALA-treated plants. Our results demonstrate that different photodynamic stress imposed by ALA and OF developed differential actions of antioxidant enzymes and detoxification. Particularly, detoxification system may play potential roles in plant protection against photodynamic stress imposed by porphyrin deregulators, thereby contributing to alleviation of photodynamic damage. Copyright © 2015 Elsevier Inc. All rights reserved.

Structure-Activity Relationship Study of Ionotropic Glutamate Receptor Antagonist (2S,3R)-3-(3-Carboxyphenyl)pyrrolidine-2-carboxylic Acid.

PubMed

Krogsgaard-Larsen, Niels; Storgaard, Morten; Møller, Charlotte; Demmer, Charles S; Hansen, Jeanette; Han, Liwei; Monrad, Rune N; Nielsen, Birgitte; Tapken, Daniel; Pickering, Darryl S; Kastrup, Jette S; Frydenvang, Karla; Bunch, Lennart

2015-08-13

Herein we describe the first structure-activity relationship study of the broad-range iGluR antagonist (2S,3R)-3-(3-carboxyphenyl)pyrrolidine-2-carboxylic acid (1) by exploring the pharmacological effect of substituents in the 4, 4', or 5' positions and the bioisosteric substitution of the distal carboxylic acid for a phosphonic acid moiety. Of particular interest is a hydroxyl group in the 4' position 2a which induced a preference in binding affinity for homomeric GluK3 over GluK1 (Ki = 0.87 and 4.8 μM, respectively). Two X-ray structures of ligand binding domains were obtained: 2e in GluA2-LBD and 2f in GluK1-LBD, both at 1.9 Å resolution. Compound 2e induces a D1-D2 domain opening in GluA2-LBD of 17.3-18.8° and 2f a domain opening in GluK1-LBD of 17.0-17.5° relative to the structures with glutamate. The pyrrolidine-2-carboxylate moiety of 2e and 2f shows a similar binding mode as kainate. The 3-carboxyphenyl ring of 2e and 2f forms contacts comparable to those of the distal carboxylate in kainate.

Ppm1E is an in cellulo AMP-activated protein kinase phosphatase.

PubMed

Voss, Martin; Paterson, James; Kelsall, Ian R; Martín-Granados, Cristina; Hastie, C James; Peggie, Mark W; Cohen, Patricia T W

2011-01-01

Activation of 5'-AMP-activated protein kinase (AMPK) is believed to be the mechanism by which the pharmaceuticals, metformin and phenformin, exert their beneficial effects for treatment of type 2 diabetes. These biguanide drugs elevate 5'-AMP, which allosterically activates AMPK and promotes phosphorylation on Thr172 of AMPK catalytic α subunits. Although kinases phosphorylating this site have been identified, phosphatases that dephosphorylate it are unknown. The aim of this study is to identify protein phosphatase(s) that dephosphorylate AMPKα-Thr172 within cells. Our initial data indicated that members of the protein phosphatase Mg/Mn(2+)-dependent [corrected] (PPM) family and not those of the PPP family of protein serine/threonine phosphatases may be directly or indirectly inhibited by phenformin. Using antibodies raised to individual Ppm phosphatases that facilitated the assessment of their activities, phenformin stimulation of cells was found to decrease the Mg(2+)/Mn(2+)-dependent [corrected] protein serine/threonine phosphatase activity of Ppm1E and Ppm1F, but not that attributable to other PPM family members, including Ppm1A/PP2Cα. Depletion of Ppm1E, but not Ppm1A, using lentiviral-mediated stable gene silencing, increased AMPKα-Thr172 phosphorylation approximately three fold in HEK293 cells. In addition, incubation of cells with low concentrations of phenformin and depletion of Ppm1E increased AMPK phosphorylation synergistically. Ppm1E and the closely related Ppm1F interact weakly with AMPK and assays with lysates of cells stably depleted of Ppm1F suggest [corrected] that this phosphatase contributes to dephosphorylation of AMPK. The data indicate that Ppm1E and probably PpM1F are in cellulo AMPK phosphatases and that Ppm1E is a potential anti-diabetic drug target. Copyright © 2010 Elsevier Inc. All rights reserved.

E2F1-mediated upregulation of p19INK4d determines its periodic expression during cell cycle and regulates cellular proliferation.

PubMed

Carcagno, Abel L; Marazita, Mariela C; Ogara, María F; Ceruti, Julieta M; Sonzogni, Silvina V; Scassa, María E; Giono, Luciana E; Cánepa, Eduardo T

2011-01-01

A central aspect of development and disease is the control of cell proliferation through regulation of the mitotic cycle. Cell cycle progression and directionality requires an appropriate balance of positive and negative regulators whose expression must fluctuate in a coordinated manner. p19INK4d, a member of the INK4 family of CDK inhibitors, has a unique feature that distinguishes it from the remaining INK4 and makes it a likely candidate for contributing to the directionality of the cell cycle. p19INK4d mRNA and protein levels accumulate periodically during the cell cycle under normal conditions, a feature reminiscent of cyclins. In this paper, we demonstrate that p19INK4d is transcriptionally regulated by E2F1 through two response elements present in the p19INK4d promoter. Ablation of this regulation reduced p19 levels and restricted its expression during the cell cycle, reflecting the contribution of a transcriptional effect of E2F1 on p19 periodicity. The induction of p19INK4d is delayed during the cell cycle compared to that of cyclin E, temporally separating the induction of these proliferative and antiproliferative target genes. Specific inhibition of the E2F1-p19INK4d pathway using triplex-forming oligonucleotides that block E2F1 binding on p19 promoter, stimulated cell proliferation and increased the fraction of cells in S phase. The results described here support a model of normal cell cycle progression in which, following phosphorylation of pRb, free E2F induces cyclin E, among other target genes. Once cyclinE/CDK2 takes over as the cell cycle driving kinase activity, the induction of p19 mediated by E2F1 leads to inhibition of the CDK4,6-containing complexes, bringing the G1 phase to an end. This regulatory mechanism constitutes a new negative feedback loop that terminates the G1 phase proliferative signal, contributing to the proper coordination of the cell cycle and provides an additional mechanism to limit E2F activity.

E2F1-Mediated Upregulation of p19INK4d Determines Its Periodic Expression during Cell Cycle and Regulates Cellular Proliferation

PubMed Central

Carcagno, Abel L.; Marazita, Mariela C.; Ogara, María F.; Ceruti, Julieta M.; Sonzogni, Silvina V.; Scassa, María E.; Giono, Luciana E.; Cánepa, Eduardo T.

2011-01-01

Background A central aspect of development and disease is the control of cell proliferation through regulation of the mitotic cycle. Cell cycle progression and directionality requires an appropriate balance of positive and negative regulators whose expression must fluctuate in a coordinated manner. p19INK4d, a member of the INK4 family of CDK inhibitors, has a unique feature that distinguishes it from the remaining INK4 and makes it a likely candidate for contributing to the directionality of the cell cycle. p19INK4d mRNA and protein levels accumulate periodically during the cell cycle under normal conditions, a feature reminiscent of cyclins. Methodology/Principal Findings In this paper, we demonstrate that p19INK4d is transcriptionally regulated by E2F1 through two response elements present in the p19INK4d promoter. Ablation of this regulation reduced p19 levels and restricted its expression during the cell cycle, reflecting the contribution of a transcriptional effect of E2F1 on p19 periodicity. The induction of p19INK4d is delayed during the cell cycle compared to that of cyclin E, temporally separating the induction of these proliferative and antiproliferative target genes. Specific inhibition of the E2F1-p19INK4d pathway using triplex-forming oligonucleotides that block E2F1 binding on p19 promoter, stimulated cell proliferation and increased the fraction of cells in S phase. Conclusions/Significance The results described here support a model of normal cell cycle progression in which, following phosphorylation of pRb, free E2F induces cyclin E, among other target genes. Once cyclinE/CDK2 takes over as the cell cycle driving kinase activity, the induction of p19 mediated by E2F1 leads to inhibition of the CDK4,6-containing complexes, bringing the G1 phase to an end. This regulatory mechanism constitutes a new negative feedback loop that terminates the G1 phase proliferative signal, contributing to the proper coordination of the cell cycle and provides an additional mechanism to limit E2F activity. PMID:21765927

Transposable Element Misregulation Is Linked to the Divergence between Parental piRNA Pathways in Drosophila Hybrids

PubMed Central

Romero-Soriano, Valèria; Modolo, Laurent; Lopez-Maestre, Hélène; Mugat, Bruno; Pessia, Eugénie; Chambeyron, Séverine; Vieira, Cristina

2017-01-01

Abstract Interspecific hybridization is a genomic stress condition that leads to the activation of transposable elements (TEs) in both animals and plants. In hybrids between Drosophila buzzatii and Drosophila koepferae, mobilization of at least 28 TEs has been described. However, the molecular mechanisms underlying this TE release remain poorly understood. To give insight on the causes of this TE activation, we performed a TE transcriptomic analysis in ovaries (notorious for playing a major role in TE silencing) of parental species and their F1 and backcrossed (BC) hybrids. We find that 15.2% and 10.6% of the expressed TEs are deregulated in F1 and BC1 ovaries, respectively, with a bias toward overexpression in both cases. Although differences between parental piRNA (Piwi-interacting RNA) populations explain only partially these results, we demonstrate that piRNA pathway proteins have divergent sequences and are differentially expressed between parental species. Thus, a functional divergence of the piRNA pathway between parental species, together with some differences between their piRNA pools, might be at the origin of hybrid instabilities and ultimately cause TE misregulation in ovaries. These analyses were complemented with the study of F1 testes, where TEs tend to be less expressed than in D. buzzatii. This can be explained by an increase in piRNA production, which probably acts as a defence mechanism against TE instability in the male germline. Hence, we describe a differential impact of interspecific hybridization in testes and ovaries, which reveals that TE expression and regulation are sex-biased. PMID:28854624

Importance of maternal diabetes on the chronological deregulation of the intrauterine development: an experimental study in rat.

PubMed

Salazar García, Marcela; Reyes Maldonado, Elba; Revilla Monsalve, María Cristina; Villavicencio Guzmán, Laura; Reyes López, Alfonso; Sánchez-Gómez, Concepción

2015-01-01

We investigated whether maternal diabetes induced in rats using streptozotocin (STZ) on Day 5 of pregnancy affects the intrauterine developmental timeline. A total of 30 pregnant Sprague-Dawley diabetic rats (DRs) and 20 control rats (CRs) were used to obtain 21-day fetuses (F21) and newborn (NB) pups. Gestational age, weight, and body size were recorded as were the maxillofacial morphometry and morphohistological characteristics of the limbs. In DRs, pregnancy continued for ∼1.7 days, and delivery occurred 23 days postcoitus (DPC). In this group, the number of pups was lower, and 13% had maxillofacial defects. F21 in the DR group had lower weights and were smaller; moreover, the morphological characteristics of the maxillofacial structures, derived from the neural crest, were discordant with their chronological gestational age, resembling 18- to 19-day-old fetuses. These deficiencies were counterbalanced in NB pups. We conclude that hyperglycemia, which results from maternal diabetes and precedes embryo implantation, deregulates the intrauterine developmental timeline, restricts embryo-fetal growth, and primarily delays the remodeling and maturation of the structures derived from neural crest cells.

Linked Tumor-Selective Virus Replication and Transgene Expression from E3-Containing Oncolytic Adenoviruses†

PubMed Central

Zhu, Mingzhu; Bristol, J. Andrew; Xie, Yuefeng; Mina, Mervat; Ji, Hong; Forry-Schaudies, Suzanne; Ennist, David L.

2005-01-01

Historically, the adenoviral E3 region was found to be nonessential for viral replication in vitro. In addition, adenoviruses whose genome was more than approximately 105% the size of the native genome were inefficiently packaged. These profound observations were used experimentally to insert transgenes into the adenoviral backbone. More recently, however, the reintroduction of the E3 region into oncolytic adenoviruses has been found to positively influence antitumor efficacy in preclinical models and clinical trials. In the studies reported here, the granulocyte-macrophage colony-stimulating factor (GM-CSF) cDNA sequence has been substituted for the E3-gp19 gene in oncolytic adenoviruses that otherwise retained the E3 region. Five viruses that differed slightly in the method of transgene insertion were generated and compared to Ar6pAE2fGmF (E2F/GM/ΔE3), a previously described E3-deleted oncolytic adenovirus encoding GM-CSF. In all of the viruses, the human E2F-1 promoter regulated E1A expression and GM-CSF expression was under the control of the adenoviral E3 promoter and the packaging signal was relocated immediately upstream from the right terminal repeat. The E3-gp19-deleted viruses had similar cytolytic properties, as measured in vitro by cytotoxicity assays, but differed markedly in their capacity to express and secrete GM-CSF. Ar15pAE2fGmF (E2F/GM/E3b), the virus that produced the highest levels of GM-CSF and retained the native GM-CSF leader sequence, was selected for further analysis. The E2F/GM/E3b and E2F/GM/ΔE3 viruses exhibited similar cytotoxic activity and GM-CSF production in several tumor cell lines in vitro. However, when compared in vivo in nude mouse xenograft tumor models, E2F/GM/E3b spread through tumors to a greater extent, resulted in higher peak GM-CSF and total exposure levels in both tumor and serum, and was more efficacious than the E3-deleted virus. Using the matched WI-38 (parental) and WI-38-VA13 (simian virus 40 large T antigen transformed) cell pair, GM-CSF was shown to be selectively produced in cells expressing high levels of E2F, indicating that the tumor-selective E2F promoter controlled E1A and GM-CSF expression. PMID:15827160

Synthesis, characterization and cytotoxic activity of substituted benzyl iminoether Pt(II) complexes of the type cis- and trans-[PtCl2{E-N(H)=C(OMe)CH2-C6H4-p-R}2] (R=Me, OMe, F). X-ray structure of trans-[PtCl2{E-N(H)=C(OMe)CH2-C6H4-p-F}2].

PubMed

Mazzega Sbovata, Silvia; Bettio, Frazia; Marzano, Christine; Tassan, Augusto; Mozzon, Mirto; Bertani, Roberta; Benetollo, Franco; Michelin, Rino A

2008-04-01

New substituted benzyl iminoether derivatives of the type cis- and trans-[PtCl(2){E-N(H)C(OMe)CH(2)-C(6)H(4)-p-R}(2)] (R=Me (1a, 2a), OMe (3a, 4a), F (5a, 6a)) have been synthesized and characterized by elemental analyses, FT-IR spectroscopy and NMR techniques. The iminoether ligands are in the E configuration, which is stable in solution and in the solid state, as confirmed by the (1)H NMR data. Complex trans-[PtCl(2){E-N(H)C(OMe)CH(2)-C(6)H(4)-p-F}(2)] (6a) was also characterized by an X-ray diffraction study. Complexes 1a-6a have been tested against a panel of human tumor cell lines in order to evaluate their cytotoxic activity. cis-Isomers were significant more potent than the corresponding trans-isomers against all tumor cell lines tested; moreover, complexes 1a and 5a showed IC(50) values from about 2-fold to 6-fold lower than those exhibited by cisplatin, used as reference platinum anticancer drug.

Guide to purchasing electricity and gas

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

Cunningham, P.R.; Burrell, D.

1999-09-01

An issue which now faces all energy users is understanding the specifics of the impact of the deregulation of the electric and natural gas industries. This book was written to help one understand the forces behind deregulation, and how one can use this knowledge now to negotiate lower utility rates, even if deregulation has not been fully implemented in one`s area. Readers will learn how coordinating new rate packages with the management of in-house loads can multiply savings. Essential ingredients to successful negotiation are clearly outlined, including assessing the alternatives for both load management and supply, understanding interruptible rate options,more » doing homework on ongoing deregulation activities, finding out who makes the decisions and working directly with them, and hands-on involvement in fine tuning the final contract. Case studies are also included.« less

The Retinoblastoma Tumor Suppressor Regulates a Xenobiotic Detoxification Pathway

PubMed Central

Sáenz Robles, Maria Teresa; Case, Ashley; Chong, Jean-Leon; Leone, Gustavo; Pipas, James M.

2011-01-01

The retinoblastoma tumor suppressor (pRb) regulates cell cycle entry, progression and exit by controlling the activity of the E2F-family of transcription factors. During cell cycle exit pRb acts as a transcriptional repressor by associating with E2F proteins and thereby inhibiting their ability to stimulate the expression of genes required for S phase. Indeed, many tumors harbor mutations in the RB gene and the pRb-E2F pathway is compromised in nearly all types of cancers. In this report we show that both pRb and its interacting partners, the transcriptional factors E2F1-2-3, act as positive modulators of detoxification pathways important for metabolizing and clearing xenobiotics—such as toxins and drugs—from the body. Using a combination of conventional molecular biology techniques and microarray analysis of specific cell populations, we have analyzed the detoxification pathway in murine samples in the presence or absence of pRb and/or E2F1-2-3. In this report, we show that both pRb and E2F1-2-3 act as positive modulators of detoxification pathways in mice, challenging the conventional view of E2F1-2-3 as transcriptional repressors negatively regulated by pRb. These results suggest that mutations altering the pRb-E2F axis may have consequences beyond loss of cell cycle control by altering the ability of tissues to remove toxins and to properly metabolize anticancer drugs, and might help to understand the formation and progression rates of different types of cancer, as well as to better design appropriate therapies based on the particular genetic composition of the tumors. PMID:22022495

76 FR 6759 - Monsanto Company and KWS SAAT AG; Decision With Respect to the Petition for Partial Deregulation...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-08

... Genetically Engineered Roundup Ready Sugar Beets AGENCY: Animal and Plant Health Inspection Service, USDA... Ready[supreg] sugar beets developed by the Monsanto Company (Monsanto) and KWS SAAT AG (KWS), designated.... APHIS will grant a partial deregulation for event H7-1 sugar beet root crop production activities when...

Jak2 FERM Domain Interaction with the Erythropoietin Receptor Regulates Jak2 Kinase Activity▿

PubMed Central

Funakoshi-Tago, Megumi; Pelletier, Stéphane; Moritake, Hiroshi; Parganas, Evan; Ihle, James N.

2008-01-01

Janus kinases are essential for signal transduction by a variety of cytokine receptors and when inappropriately activated can cause hematopoietic disorders and oncogenesis. Consequently, it can be predicted that the interaction of the kinases with receptors and the events required for activation are highly controlled. In a screen to identify phosphorylation events regulating Jak2 activity in EpoR signaling, we identified a mutant (Jak2-Y613E) which has the property of being constitutively activated, as well as an inactivating mutation (Y766E). Although no evidence was obtained to indicate that either site is phosphorylated in signaling, the consequences of the Y613E mutation are similar to those observed with recently described activating mutations in Jak2 (Jak2-V617F and Jak2-L611S). However, unlike the V617F or L611S mutant, the Y613E mutant requires the presence of the receptor but not Epo stimulation for activation and downstream signaling. The properties of the Jak2-Y613E mutant suggest that under normal conditions, Jak2 that is not associated with a receptor is locked into an inactive state and receptor binding through the FERM domain relieves steric constraints, allowing the potential to be activated with receptor engagement. PMID:18160720

Cytochalasin E alters the cytoskeleton and decreases ENaC activity in Xenopus 2F3 cells.

PubMed

Reifenberger, Matthew S; Yu, Ling; Bao, Hui-Fang; Duke, Billie Jeanne; Liu, Bing-Chen; Ma, He-Ping; Alli, Ahmed A; Eaton, Douglas C; Alli, Abdel A

2014-07-01

Numerous reports have linked cytoskeleton-associated proteins with the regulation of epithelial Na(+) channel (ENaC) activity. The purpose of the present study was to determine the effect of actin cytoskeleton disruption by cytochalasin E on ENaC activity in Xenopus 2F3 cells. Here, we show that cytochalasin E treatment for 60 min can disrupt the integrity of the actin cytoskeleton in cultured Xenopus 2F3 cells. We show using single channel patch-clamp experiments and measurements of short-circuit current that ENaC activity, but not its density, is altered by cytochalasin E-induced disruption of the cytoskeleton. In nontreated cells, 8 of 33 patches (24%) had no measurable ENaC activity, whereas in cytochalasin E-treated cells, 17 of 32 patches (53%) had no activity. Analysis of those patches that did contain ENaC activity showed channel open probability significantly decreased from 0.081 ± 0.01 in nontreated cells to 0.043 ± 0.01 in cells treated with cytochalasin E. Transepithelial current from mpkCCD cells treated with cytochalasin E, cytochalasin D, or latrunculin B for 60 min was decreased compared with vehicle-treated cells. The subcellular expression of fodrin changed significantly, and several protein elements of the cytoskeleton decreased at least twofold after 60 min of cytochalasin E treatment. Cytochalasin E treatment disrupted the association between ENaC and myristoylated alanine-rich C-kinase substrate. The results presented here suggest disruption of the actin cytoskeleton by different compounds can attenuate ENaC activity through a mechanism involving changes in the subcellular expression of fodrin, several elements of the cytoskeleton, and destabilization of the ENaC-myristoylated alanine-rich C-kinase substrate complex. Copyright © 2014 the American Physiological Society.

Cytochalasin E alters the cytoskeleton and decreases ENaC activity in Xenopus 2F3 cells

PubMed Central

Reifenberger, Matthew S.; Yu, Ling; Bao, Hui-Fang; Duke, Billie Jeanne; Liu, Bing-Chen; Ma, He-Ping; Eaton, Douglas C.; Alli, Abdel A.

2014-01-01

Numerous reports have linked cytoskeleton-associated proteins with the regulation of epithelial Na+ channel (ENaC) activity. The purpose of the present study was to determine the effect of actin cytoskeleton disruption by cytochalasin E on ENaC activity in Xenopus 2F3 cells. Here, we show that cytochalasin E treatment for 60 min can disrupt the integrity of the actin cytoskeleton in cultured Xenopus 2F3 cells. We show using single channel patch-clamp experiments and measurements of short-circuit current that ENaC activity, but not its density, is altered by cytochalasin E-induced disruption of the cytoskeleton. In nontreated cells, 8 of 33 patches (24%) had no measurable ENaC activity, whereas in cytochalasin E-treated cells, 17 of 32 patches (53%) had no activity. Analysis of those patches that did contain ENaC activity showed channel open probability significantly decreased from 0.081 ± 0.01 in nontreated cells to 0.043 ± 0.01 in cells treated with cytochalasin E. Transepithelial current from mpkCCD cells treated with cytochalasin E, cytochalasin D, or latrunculin B for 60 min was decreased compared with vehicle-treated cells. The subcellular expression of fodrin changed significantly, and several protein elements of the cytoskeleton decreased at least twofold after 60 min of cytochalasin E treatment. Cytochalasin E treatment disrupted the association between ENaC and myristoylated alanine-rich C-kinase substrate. The results presented here suggest disruption of the actin cytoskeleton by different compounds can attenuate ENaC activity through a mechanism involving changes in the subcellular expression of fodrin, several elements of the cytoskeleton, and destabilization of the ENaC-myristoylated alanine-rich C-kinase substrate complex. PMID:24829507

Peroxisome Proliferator-Activated Receptor β/δ Cross Talks with E2F and Attenuates Mitosis in HRAS-Expressing Cells

PubMed Central

Zhu, Bokai; Khozoie, Combiz; Bility, Moses T.; Ferry, Christina H.; Blazanin, Nicholas; Glick, Adam B.; Gonzalez, Frank J.

2012-01-01

The role of peroxisome proliferator-activated receptor β/δ (PPARβ/δ) in Harvey sarcoma ras (Hras)-expressing cells was examined. Ligand activation of PPARβ/δ caused a negative selection with respect to cells expressing higher levels of the Hras oncogene by inducing a mitotic block. Mitosis-related genes that are predominantly regulated by E2F were induced to a higher level in HRAS-expressing Pparβ/δ-null keratinocytes compared to HRAS-expressing wild-type keratinocytes. Ligand-activated PPARβ/δ repressed expression of these genes by direct binding with p130/p107, facilitating nuclear translocation and increasing promoter recruitment of p130/p107. These results demonstrate a novel mechanism of PPARβ/δ cross talk with E2F signaling. Since cotreatment with a PPARβ/δ ligand and various mitosis inhibitors increases the efficacy of increasing G2/M arrest, targeting PPARβ/δ in conjunction with mitosis inhibitors could become a suitable option for development of new multitarget strategies for inhibiting RAS-dependent tumorigenesis. PMID:22473992

Itch/β-arrestin2-dependent non-proteolytic ubiquitylation of SuFu controls Hedgehog signalling and medulloblastoma tumorigenesis.

PubMed

Infante, Paola; Faedda, Roberta; Bernardi, Flavia; Bufalieri, Francesca; Lospinoso Severini, Ludovica; Alfonsi, Romina; Mazzà, Daniela; Siler, Mariangela; Coni, Sonia; Po, Agnese; Petroni, Marialaura; Ferretti, Elisabetta; Mori, Mattia; De Smaele, Enrico; Canettieri, Gianluca; Capalbo, Carlo; Maroder, Marella; Screpanti, Isabella; Kool, Marcel; Pfister, Stefan M; Guardavaccaro, Daniele; Gulino, Alberto; Di Marcotullio, Lucia

2018-03-07

Suppressor of Fused (SuFu), a tumour suppressor mutated in medulloblastoma, is a central player of Hh signalling, a pathway crucial for development and deregulated in cancer. Although the control of Gli transcription factors by SuFu is critical in Hh signalling, our understanding of the mechanism regulating this key event remains limited. Here, we show that the Itch/β-arrestin2 complex binds SuFu and induces its Lys63-linked polyubiquitylation without affecting its stability. This process increases the association of SuFu with Gli3, promoting the conversion of Gli3 into a repressor, which keeps Hh signalling off. Activation of Hh signalling antagonises the Itch-dependent polyubiquitylation of SuFu. Notably, different SuFu mutations occurring in medulloblastoma patients are insensitive to Itch activity, thus leading to deregulated Hh signalling and enhancing medulloblastoma cell growth. Our findings uncover mechanisms controlling the tumour suppressive functions of SuFu and reveal that their alterations are implicated in medulloblastoma tumorigenesis.

Comparative Analysis of Toxic Responses of Organic Extracts from Diesel and Selected Alternative Fuels Engine Emissions in Human Lung BEAS-2B Cells

PubMed Central

Libalova, Helena; Rossner,, Pavel; Vrbova, Kristyna; Brzicova, Tana; Sikorova, Jitka; Vojtisek-Lom, Michal; Beranek, Vit; Klema, Jiri; Ciganek, Miroslav; Neca, Jiri; Pencikova, Katerina; Machala, Miroslav; Topinka, Jan

2016-01-01

This study used toxicogenomics to identify the complex biological response of human lung BEAS-2B cells treated with organic components of particulate matter in the exhaust of a diesel engine. First, we characterized particles from standard diesel (B0), biodiesel (methylesters of rapeseed oil) in its neat form (B100) and 30% by volume blend with diesel fuel (B30), and neat hydrotreated vegetable oil (NEXBTL100). The concentration of polycyclic aromatic hydrocarbons (PAHs) and their derivatives in organic extracts was the lowest for NEXBTL100 and higher for biodiesel. We further analyzed global gene expression changes in BEAS-2B cells following 4 h and 24 h treatment with extracts. The concentrations of 50 µg extract/mL induced a similar molecular response. The common processes induced after 4 h treatment included antioxidant defense, metabolism of xenobiotics and lipids, suppression of pro-apoptotic stimuli, or induction of plasminogen activating cascade; 24 h treatment affected fewer processes, particularly those involved in detoxification of xenobiotics, including PAHs. The majority of distinctively deregulated genes detected after both 4 h and 24 h treatment were induced by NEXBTL100; the deregulated genes included, e.g., those involved in antioxidant defense and cell cycle regulation and proliferation. B100 extract, with the highest PAH concentrations, additionally affected several cell cycle regulatory genes and p38 signaling. PMID:27827897

Involvement of aryl hydrocarbon receptor signaling in the development of small cell lung cancer induced by HPV E6/E7 oncoproteins

PubMed Central

2011-01-01

Background Lung cancers consist of four major types that and for clinical-pathological reasons are often divided into two broad categories: small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). All major histological types of lung cancer are associated with smoking, although the association is stronger for SCLC and squamous cell carcinoma than adenocarcinoma. To date, epidemiological studies have identified several environmental, genetic, hormonal and viral factors associated with lung cancer risk. It has been estimated that 15-25% of human cancers may have a viral etiology. The human papillomavirus (HPV) is a proven cause of most human cervical cancers, and might have a role in other malignancies including vulva, skin, oesophagus, head and neck cancer. HPV has also been speculated to have a role in the pathogenesis of lung cancer. To validate the hypothesis of HPV involvement in small cell lung cancer pathogenesis we performed a gene expression profile of transgenic mouse model of SCLC induced by HPV-16 E6/E7 oncoproteins. Methods Gene expression profile of SCLC has been performed using Agilent whole mouse genome (4 × 44k) representing ~ 41000 genes and mouse transcripts. Samples were obtained from two HPV16-E6/E7 transgenic mouse models and from littermate's normal lung. Data analyses were performed using GeneSpring 10 and the functional classification of deregulated genes was performed using Ingenuity Pathway Analysis (Ingenuity® Systems, http://www.ingenuity.com). Results Analysis of deregulated genes induced by the expression of E6/E7 oncoproteins supports the hypothesis of a linkage between HPV infection and SCLC development. As a matter of fact, comparison of deregulated genes in our system and those in human SCLC showed that many of them are located in the Aryl Hydrocarbon Receptor Signal transduction pathway. Conclusions In this study, the global gene expression of transgenic mouse model of SCLC induced by HPV-16 E6/E7 oncoproteins led us to identification of several genes involved in SCLC tumor development. Furthermore, our study reveled that the Aryl Hydrocarbon Receptor Signaling is the primarily affected pathway by the E6/E7 oncoproteins expression and that this pathway is also deregulated in human SCLC. Our results provide the basis for the development of new therapeutic approaches against human SCLC. PMID:21205295

Oncogenic B-Raf(V600E) abrogates the AKT/B-Raf/Mps1 interaction in melanoma cells.

PubMed

Zhang, Ling; Shi, Ruyi; He, Chanting; Cheng, Caixia; Song, Bin; Cui, Heyang; Zhang, Yanyan; Zhao, Zhiping; Bi, Yanghui; Yang, Xiaofeng; Miao, Xiaoping; Guo, Jiansheng; Chen, Xing; Wang, Jinfen; Li, Yaoping; Cheng, Xiaolong; Liu, Jing; Cui, Yongping

2013-08-28

Activating B-Raf mutations that deregulate the mitogen-activated protein kinase (MAPK) pathway commonly occur in cancer. Although B-Raf(V600E) induces increased Mps1 protein contributing to centrosome amplification and chromosome instability, the regulatory mechanisms of Mps1 in melanoma cells is not fully understood. Here, we report that Mps1/AKT and B-Raf(WT)/ERK signaling form an auto-regulatory negative feedback loop in melanoma cells; notably, oncogenic B-Raf(V600E) abrogates the negative feedback loop, contributing the aberrant Mps1 functions and tumorigenesis. Our findings raise the possibility that targeting the oncogenic B-Raf and Mps1, especially when used in combination could potentially provide great therapeutic opportunities for cancer treatment. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

miR-132 and miR-212 are increased in pancreatic cancer and target the retinoblastoma tumor suppressor

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

Park, Jong-Kook; Henry, Jon C.; Jiang, Jinmai

2011-03-25

Research highlights: {yields} The expression of miR-132 and miR-212 are significantly increased in pancreatic cancer. {yields} miR-132 and miR-212 target the tumor suppressor pRb, resulting in enhanced proliferation. {yields} miR-132 and miR-212 expression is increased by a {beta}2 adrenergic receptor agonist, suggesting a novel mechanism for pancreatic cancer progression. -- Abstract: Numerous microRNAs (miRNAs) are reported as differentially expressed in cancer, however the consequence of miRNA deregulation in cancer is unknown for many miRNAs. We report that two miRNAs located on chromosome 17p13, miR-132 and miR-212, are over-expressed in pancreatic adenocarcinoma (PDAC) tissues. Both miRNAs are predicted to target themore » retinoblastoma tumor suppressor, Rb1. Validation of this interaction was confirmed by luciferase reporter assay and western blot in a pancreatic cancer cell line transfected with pre-miR-212 and pre-miR-132 oligos. Cell proliferation was enhanced in Panc-1 cells transfected with pre-miR-132/-212 oligos. Conversely, antisense oligos to miR-132/-212 reduced cell proliferation and caused a G{sub 2}/M cell cycle arrest. The mRNA of a number of E2F transcriptional targets were increased in cells over expressing miR-132/-212. Exposing Panc-1 cells to the {beta}2 adrenergic receptor agonist, terbutaline, increased the miR-132 and miR-212 expression by 2- to 4-fold. We report that over-expression of miR-132 and miR-212 result in reduced pRb protein in pancreatic cancer cells and that the increase in cell proliferation from over-expression of these miRNAs is likely due to increased expression of several E2F target genes. The {beta}2 adrenergic pathway may play an important role in this novel mechanism.« less

Ubiquitin-Dependent Regulation of the Mammalian Hippo Pathway: Therapeutic Implications for Cancer.

PubMed

Nguyen, Thanh Hung; Kugler, Jan-Michael

2018-04-17

The Hippo pathway serves as a key barrier for oncogenic transformation. It acts by limiting the activity of the proto-oncogenes YAP and TAZ. Reduced Hippo signaling and elevated YAP/TAZ activities are frequently observed in various types of tumors. Emerging evidence suggests that the ubiquitin system plays an important role in regulating Hippo pathway activity. Deregulation of ubiquitin ligases and of deubiquitinating enzymes has been implicated in increased YAP/TAZ activity in cancer. In this article, we review recent insights into the ubiquitin-mediated regulation of the mammalian Hippo pathway, its deregulation in cancer, and possibilities for targeting the Hippo pathway through the ubiquitin system.

Bismuth heterocycles based on a diphenyl sulfone scaffold: synthesis and substituent effect on the antifungal activity against Saccharomyces cerevisiae.

PubMed

Murafuji, Toshihiro; Fujiwara, Yudai; Yoshimatsu, Daisuke; Miyakawa, Isamu; Migita, Kouto; Mikata, Yuji

2011-02-01

A series of heterocyclic organobismuth(III) compounds 2 [ClBi(5-R-C6H(3)-2-SO2C6H(4)-1'-): R=Me, Ph, MeO, Cl, H, t-Bu, CF3, F, Me2N] was synthesized in order to study the relative importance of structure and specific substitutions in relation to their lipophilicity and antifungal activity against the yeast Saccharomyces cerevisiae. A clear structure-activity relationship between the size of the inhibition zone and the value of ClogP was found for 2. These results suggest that the higher the lipophilicity, the lower the antifungal activity. Thus, 2e (R=H) and 2h (R=F), which had ClogP values of 1.18 and 1.45, respectively, were most active. In contrast, 2b (R=Ph) and 2f (R=t-Bu) had ClogP values of 3.06 and 3.00, respectively, and exhibited no antifungal activity. Compound 6b ClBi[5-(OH)C6H(3)-2-SO(2)-5'-(OH)C6H(3)-1'-] had an estimated ClogP value of 0.81 but exhibited only low activity in spite of its low ClogP value, suggesting that such a considerable decrease in lipophilicity lowers inhibition activity. Bismuth carboxylate 7b derived from p-nitrobenzoic acid and 2e exhibited inhibition activity comparable to those of 2e and 2h despite its higher lipophilicity (ClogP=2.68). Copyright © 2010 Elsevier Masson SAS. All rights reserved.

Novel engineered cationic antimicrobial peptides display broad-spectrum activity against Francisella tularensis, Yersinia pestis and Burkholderia pseudomallei.

PubMed

Abdelbaqi, Suha; Deslouches, Berthony; Steckbeck, Jonathan; Montelaro, Ronald; Reed, Douglas S

2016-02-01

Broad-spectrum antimicrobials are needed to effectively treat patients infected in the event of a pandemic or intentional release of a pathogen prior to confirmation of the pathogen's identity. Engineered cationic antimicrobial peptides (eCAPs) display activity against a number of bacterial pathogens including multi-drug-resistant strains. Two lead eCAPs, WLBU2 and WR12, were compared with human cathelicidin (LL-37) against three highly pathogenic bacteria: Francisella tularensis, Yersinia pestis and Burkholderia pseudomallei. Both WLBU2 and WR12 demonstrated bactericidal activity greater than that of LL-37, particularly against F. tularensis and Y. pestis. Only WLBU2 had bactericidal activity against B. pseudomallei. WLBU2, WR12 and LL-37 were all able to inhibit the growth of the three bacteria in vitro. Because these bacteria can be facultative intracellular pathogens, preferentially infecting macrophages and dendritic cells, we evaluated the activity of WLBU2 against F. tularensis in an ex vivo infection model with J774 cells, a mouse macrophage cell line. In that model WLBU2 was able to achieve greater than 50% killing of F. tularensis at a concentration of 12.5 μM. These data show the therapeutic potential of eCAPs, particularly WLBU2, as a broad-spectrum antimicrobial for treating highly pathogenic bacterial infections.

Deregulation of an imprinted gene network in prostate cancer

PubMed Central

Ribarska, Teodora; Goering, Wolfgang; Droop, Johanna; Bastian, Klaus-Marius; Ingenwerth, Marc; Schulz, Wolfgang A

2014-01-01

Multiple epigenetic alterations contribute to prostate cancer progression by deregulating gene expression. Epigenetic mechanisms, especially differential DNA methylation at imprinting control regions (termed DMRs), normally ensure the exclusive expression of imprinted genes from one specific parental allele. We therefore wondered to which extent imprinted genes become deregulated in prostate cancer and, if so, whether deregulation is due to altered DNA methylation at DMRs. Therefore, we selected presumptive deregulated imprinted genes from a previously conducted in silico analysis and from the literature and analyzed their expression in prostate cancer tissues by qRT-PCR. We found significantly diminished expression of PLAGL1/ZAC1, MEG3, NDN, CDKN1C, IGF2, and H19, while LIT1 was significantly overexpressed. The PPP1R9A gene, which is imprinted in selected tissues only, was strongly overexpressed, but was expressed biallelically in benign and cancerous prostatic tissues. Expression of many of these genes was strongly correlated, suggesting co-regulation, as in an imprinted gene network (IGN) reported in mice. Deregulation of the network genes also correlated with EZH2 and HOXC6 overexpression. Pyrosequencing analysis of all relevant DMRs revealed generally stable DNA methylation between benign and cancerous prostatic tissues, but frequent hypo- and hyper-methylation was observed at the H19 DMR in both benign and cancerous tissues. Re-expression of the ZAC1 transcription factor induced H19, CDKN1C and IGF2, supporting its function as a nodal regulator of the IGN. Our results indicate that a group of imprinted genes are coordinately deregulated in prostate cancers, independently of DNA methylation changes. PMID:24513574

Deregulation of an imprinted gene network in prostate cancer.

PubMed

Ribarska, Teodora; Goering, Wolfgang; Droop, Johanna; Bastian, Klaus-Marius; Ingenwerth, Marc; Schulz, Wolfgang A

2014-05-01

Multiple epigenetic alterations contribute to prostate cancer progression by deregulating gene expression. Epigenetic mechanisms, especially differential DNA methylation at imprinting control regions (termed DMRs), normally ensure the exclusive expression of imprinted genes from one specific parental allele. We therefore wondered to which extent imprinted genes become deregulated in prostate cancer and, if so, whether deregulation is due to altered DNA methylation at DMRs. Therefore, we selected presumptive deregulated imprinted genes from a previously conducted in silico analysis and from the literature and analyzed their expression in prostate cancer tissues by qRT-PCR. We found significantly diminished expression of PLAGL1/ZAC1, MEG3, NDN, CDKN1C, IGF2, and H19, while LIT1 was significantly overexpressed. The PPP1R9A gene, which is imprinted in selected tissues only, was strongly overexpressed, but was expressed biallelically in benign and cancerous prostatic tissues. Expression of many of these genes was strongly correlated, suggesting co-regulation, as in an imprinted gene network (IGN) reported in mice. Deregulation of the network genes also correlated with EZH2 and HOXC6 overexpression. Pyrosequencing analysis of all relevant DMRs revealed generally stable DNA methylation between benign and cancerous prostatic tissues, but frequent hypo- and hyper-methylation was observed at the H19 DMR in both benign and cancerous tissues. Re-expression of the ZAC1 transcription factor induced H19, CDKN1C and IGF2, supporting its function as a nodal regulator of the IGN. Our results indicate that a group of imprinted genes are coordinately deregulated in prostate cancers, independently of DNA methylation changes.

Deregulation of PPARβ/δ target genes in tumor-associated macrophages by fatty acid ligands in the ovarian cancer microenvironment.

PubMed

Schumann, Tim; Adhikary, Till; Wortmann, Annika; Finkernagel, Florian; Lieber, Sonja; Schnitzer, Evelyn; Legrand, Nathalie; Schober, Yvonne; Nockher, W Andreas; Toth, Philipp M; Diederich, Wibke E; Nist, Andrea; Stiewe, Thorsten; Wagner, Uwe; Reinartz, Silke; Müller-Brüsselbach, Sabine; Müller, Rolf

2015-05-30

The nuclear receptor peroxisome proliferator-activated receptor β/δ (PPARβ/δ) is a lipid ligand-inducible transcription factor associated with macrophage polarization. However, its function in tumor-associated macrophages (TAMs) has not been investigated to date. Here, we report the PPARβ/δ-regulated transcriptome and cistrome for TAMs from ovarian carcinoma patients. Comparison with monocyte-derived macrophages shows that the vast majority of direct PPARβ/δ target genes are upregulated in TAMs and largely refractory to synthetic agonists, but repressible by inverse agonists. Besides genes with metabolic functions, these include cell type-selective genes associated with immune regulation and tumor progression, e.g., LRP5, CD300A, MAP3K8 and ANGPTL4. This deregulation is not due to increased expression of PPARβ/δ or its enhanced recruitment to target genes. Instead, lipidomic analysis of malignancy-associated ascites revealed high concentrations of polyunsaturated fatty acids, in particular linoleic acid, acting as potent PPARβ/δ agonists in macrophages. These fatty acid ligands accumulate in lipid droplets in TAMs, thereby providing a reservoir of PPARβ/δ ligands. These observations suggest that the deregulation of PPARβ/δ target genes by ligands of the tumor microenvironment contributes to the pro-tumorigenic polarization of ovarian carcinoma TAMs. This conclusion is supported by the association of high ANGPTL4 expression with a shorter relapse-free survival in serous ovarian carcinoma.

Deregulation of PPARβ/δ target genes in tumor-associated macrophages by fatty acid ligands in the ovarian cancer microenvironment

PubMed Central

Finkernagel, Florian; Lieber, Sonja; Schnitzer, Evelyn; Legrand, Nathalie; Schober, Yvonne; Nockher, W. Andreas; Toth, Philipp M.; Diederich, Wibke E.; Nist, Andrea; Stiewe, Thorsten; Wagner, Uwe; Reinartz, Silke; Müller-Brüsselbach, Sabine; Müller, Rolf

2015-01-01

The nuclear receptor peroxisome proliferator-activated receptor β/δ (PPARβ/δ) is a lipid ligand-inducible transcription factor associated with macrophage polarization. However, its function in tumor-associated macrophages (TAMs) has not been investigated to date. Here, we report the PPARβ/δ-regulated transcriptome and cistrome for TAMs from ovarian carcinoma patients. Comparison with monocyte-derived macrophages shows that the vast majority of direct PPARβ/δ target genes are upregulated in TAMs and largely refractory to synthetic agonists, but repressible by inverse agonists. Besides genes with metabolic functions, these include cell type-selective genes associated with immune regulation and tumor progression, e.g., LRP5, CD300A, MAP3K8 and ANGPTL4. This deregulation is not due to increased expression of PPARβ/δ or its enhanced recruitment to target genes. Instead, lipidomic analysis of malignancy-associated ascites revealed high concentrations of polyunsaturated fatty acids, in particular linoleic acid, acting as potent PPARβ/δ agonists in macrophages. These fatty acid ligands accumulate in lipid droplets in TAMs, thereby providing a reservoir of PPARβ/δ ligands. These observations suggest that the deregulation of PPARβ/δ target genes by ligands of the tumor microenvironment contributes to the pro-tumorigenic polarization of ovarian carcinoma TAMs. This conclusion is supported by the association of high ANGPTL4 expression with a shorter relapse-free survival in serous ovarian carcinoma. PMID:25968567

Histone deacetylase and Cullin3-REN(KCTD11) ubiquitin ligase interplay regulates Hedgehog signalling through Gli acetylation.

PubMed

Canettieri, Gianluca; Di Marcotullio, Lucia; Greco, Azzura; Coni, Sonia; Antonucci, Laura; Infante, Paola; Pietrosanti, Laura; De Smaele, Enrico; Ferretti, Elisabetta; Miele, Evelina; Pelloni, Marianna; De Simone, Giuseppina; Pedone, Emilia Maria; Gallinari, Paola; Giorgi, Alessandra; Steinkühler, Christian; Vitagliano, Luigi; Pedone, Carlo; Schinin, M Eugenià; Screpanti, Isabella; Gulino, Alberto

2010-02-01

Hedgehog signalling is crucial for development and is deregulated in several tumours, including medulloblastoma. Regulation of the transcriptional activity of Gli (glioma-associated oncogene) proteins, effectors of the Hedgehog pathway, is poorly understood. We show here that Gli1 and Gli2 are acetylated proteins and that their HDAC-mediated deacetylation promotes transcriptional activation and sustains a positive autoregulatory loop through Hedgehog-induced upregulation of HDAC1. This mechanism is turned off by HDAC1 degradation through an E3 ubiquitin ligase complex formed by Cullin3 and REN, a Gli antagonist lost in human medulloblastoma. Whereas high HDAC1 and low REN expression in neural progenitors and medulloblastomas correlates with active Hedgehog signalling, loss of HDAC activity suppresses Hedgehog-dependent growth of neural progenitors and tumour cells. Consistent with this, abrogation of Gli1 acetylation enhances cellular proliferation and transformation. These data identify an integrated HDAC- and ubiquitin-mediated circuitry, where acetylation of Gli proteins functions as an unexpected key transcriptional checkpoint of Hedgehog signalling.

Electron Spin Relaxation and Biochemical Characterization of the Hydrogenase Maturase HydF: Insights into [2Fe-2S] and [4Fe-4S] Cluster Communication and Hydrogenase Activation.

PubMed

Shepard, Eric M; Byer, Amanda S; Aggarwal, Priyanka; Betz, Jeremiah N; Scott, Anna G; Shisler, Krista A; Usselman, Robert J; Eaton, Gareth R; Eaton, Sandra S; Broderick, Joan B

2017-06-27

Nature utilizes [FeFe]-hydrogenase enzymes to catalyze the interconversion between H 2 and protons and electrons. Catalysis occurs at the H-cluster, a carbon monoxide-, cyanide-, and dithiomethylamine-coordinated 2Fe subcluster bridged via a cysteine to a [4Fe-4S] cluster. Biosynthesis of this unique metallocofactor is accomplished by three maturase enzymes denoted HydE, HydF, and HydG. HydE and HydG belong to the radical S-adenosylmethionine superfamily of enzymes and synthesize the nonprotein ligands of the H-cluster. These enzymes interact with HydF, a GTPase that acts as a scaffold or carrier protein during 2Fe subcluster assembly. Prior characterization of HydF demonstrated the protein exists in both dimeric and tetrameric states and coordinates both [4Fe-4S] 2+/+ and [2Fe-2S] 2+/+ clusters [Shepard, E. M., Byer, A. S., Betz, J. N., Peters, J. W., and Broderick, J. B. (2016) Biochemistry 55, 3514-3527]. Herein, electron paramagnetic resonance (EPR) is utilized to characterize the [2Fe-2S] + and [4Fe-4S] + clusters bound to HydF. Examination of spin relaxation times using pulsed EPR in HydF samples exhibiting both [4Fe-4S] + and [2Fe-2S] + cluster EPR signals supports a model in which the two cluster types either are bound to widely separated sites on HydF or are not simultaneously bound to a single HydF species. Gel filtration chromatographic analyses of HydF spectroscopic samples strongly suggest the [2Fe-2S] + and [4Fe-4S] + clusters are coordinated to the dimeric form of the protein. Lastly, we examined the 2Fe subcluster-loaded form of HydF and showed the dimeric state is responsible for [FeFe]-hydrogenase activation. Together, the results indicate a specific role for the HydF dimer in the H-cluster biosynthesis pathway.

Electron Spin Relaxation and Biochemical Characterization of the Hydrogenase Maturase HydF: Insights into [2Fe-2S] and [4Fe-4S] Cluster Communication and Hydrogenase Activation

PubMed Central

2017-01-01

Nature utilizes [FeFe]-hydrogenase enzymes to catalyze the interconversion between H2 and protons and electrons. Catalysis occurs at the H-cluster, a carbon monoxide-, cyanide-, and dithiomethylamine-coordinated 2Fe subcluster bridged via a cysteine to a [4Fe-4S] cluster. Biosynthesis of this unique metallocofactor is accomplished by three maturase enzymes denoted HydE, HydF, and HydG. HydE and HydG belong to the radical S-adenosylmethionine superfamily of enzymes and synthesize the nonprotein ligands of the H-cluster. These enzymes interact with HydF, a GTPase that acts as a scaffold or carrier protein during 2Fe subcluster assembly. Prior characterization of HydF demonstrated the protein exists in both dimeric and tetrameric states and coordinates both [4Fe-4S]2+/+ and [2Fe-2S]2+/+ clusters [Shepard, E. M., Byer, A. S., Betz, J. N., Peters, J. W., and Broderick, J. B. (2016) Biochemistry 55, 3514–3527]. Herein, electron paramagnetic resonance (EPR) is utilized to characterize the [2Fe-2S]+ and [4Fe-4S]+ clusters bound to HydF. Examination of spin relaxation times using pulsed EPR in HydF samples exhibiting both [4Fe-4S]+ and [2Fe-2S]+ cluster EPR signals supports a model in which the two cluster types either are bound to widely separated sites on HydF or are not simultaneously bound to a single HydF species. Gel filtration chromatographic analyses of HydF spectroscopic samples strongly suggest the [2Fe-2S]+ and [4Fe-4S]+ clusters are coordinated to the dimeric form of the protein. Lastly, we examined the 2Fe subcluster-loaded form of HydF and showed the dimeric state is responsible for [FeFe]-hydrogenase activation. Together, the results indicate a specific role for the HydF dimer in the H-cluster biosynthesis pathway. PMID:28525271

The Vulnerability of Occupational Health and Safety to Deregulation: The Weakening of Information Regulations during the Economic Crisis in Korea.

PubMed

Jhang, Won Gi

2018-05-01

This study was conducted to investigate the causes and consequences of the vulnerability of occupational health and safety (OHS) regulations to deregulation during a period of economic crisis in the Republic of Korea. Analysis of Korea's national regulation database revealed that the vulnerability of OHS regulations to deregulation was related to the fact that OHS policy included many regulations without direct deregulatory impacts on workers. The most affected victim of this characteristic was information regulation that provided a legal basis for government's monitoring and inspection of OHS activities. The massive relaxation of information regulation has the potential to weaken government oversight and to tempt businesses to hide industrial accidents. Since changes in regulations without direct deregulatory impacts are not easily identifiable by workers, careful monitoring of deregulation is necessary to prevent policy impacts harmful to workers' health and safety.

Overexpression of the PepF Oligopeptidase Inhibits Sporulation Initiation in Bacillus subtilis†

PubMed Central

Kanamaru, Kyoko; Stephenson, Sophie; Perego, Marta

2002-01-01

The yjbG gene encoding the homologue of the PepF1 and PepF2 oligoendopeptidases of Lactococcus lactis (Monnet et al., J. Biol. Chem. 269:32070–32076, 1994; Nardi et al., J. Bacteriol. 179:4164–4171, 1997) has been identified in Bacillus subtilis as an inhibitor of sporulation initiation when present in the cells on a multicopy plasmid. Genetic analysis suggested that the inhibitory effect is due to hydrolysis of the PhrA peptide in a form as small as the pentapeptide (ARNQT). Inactivation of PhrA results in deregulation of the RapA phosphatase and thus dephosphorylation of the Spo0F∼∼P response regulator component of the phosphorelay for sporulation initiation. When overexpressed, the B. subtilis PepF is most likely hydrolyzing additional peptides of the Phr family, as is the case for PhrC involved in control of competence development. Chromosomal inactivation of the yjbG/pepF gene did not give rise to any detectable phenotype. The function of PepF in B. subtilis remains unknown. Limited experiments with a yjbG paralogue called yusX indicated that a frameshift is present, making the corresponding gene product inactive. PMID:11741842

CD147 contains different bioactive epitopes involving the regulation of cell adhesion and lymphocyte activation.

PubMed

Chiampanichayakul, Sawitree; Peng-in, Pakorn; Khunkaewla, Panida; Stockinger, Hannes; Kasinrerk, Watchara

2006-01-01

CD147 is a leukocyte surface molecule which belongs to the immunoglobulin superfamily. It is broadly expressed on various cell types and is a lymphocyte activation-associated molecule. In order to study the function of CD147, five CD147 monoclonal antibodies (mAbs) were generated: M6-2F9; M6-1D4; M6-1F3; M6-1B9; and M6-1E9. Biochemical characterizations and cross-blocking experiments indicated that M6-1B9 and M6-1E9 recognize the same or contiguous epitopes on CD147. By employing COS transfectants expressing CD147 membrane-distal domain (domain 1) and membrane-proximal domain (domain 2), mAbs M6-2F9, M6-1D4, M6-1B9, and M6-1E9 were shown to recognize epitopes located on domain 1 of the molecule. Functional studies indicated that engagement of CD147 by mAbs M6-1B9 and M6-1E9 strongly inhibited lymphocyte proliferation induced by a CD3 mAb. In contrast, mAbs M6-2F9, M6-1D4, and M6-1F3 induced U937 homotypic cell aggregation. The results indicate that CD147 contains at least two bioactive domains. Epitopes responsible for induction of cell aggregation are different from those regulating lymphocyte activation.

Job Placement in Germany: Developments before and after Deregulation. IAB Labour Market Research Topics No. 31.

ERIC Educational Resources Information Center

Walwei, Ulrich

Since 1994, the German public employment service has not had a monopoly on placement. A new law permits private job placement as an independent activity, but only with a license from the public employment service. Since deregulation, the number of job placement licenses has increased continuously, but the number of placements made by private…

Low-dose exposure to bisphenols A, F and S of human primary adipocyte impacts coding and non-coding RNA profiles

PubMed Central

Leloire, Audrey; Dhennin, Véronique; Coumoul, Xavier; Yengo, Loïc; Froguel, Philippe

2017-01-01

Bisphenol A (BPA) exposure has been suspected to be associated with deleterious effects on health including obesity and metabolically-linked diseases. Although bisphenols F (BPF) and S (BPS) are BPA structural analogs commonly used in many marketed products as a replacement for BPA, only sparse toxicological data are available yet. Our objective was to comprehensively characterize bisphenols gene targets in a human primary adipocyte model, in order to determine whether they may induce cellular dysfunction, using chronic exposure at two concentrations: a “low-dose” similar to the dose usually encountered in human biological fluids and a higher dose. Therefore, BPA, BPF and BPS have been added at 10 nM or 10 μM during the differentiation of human primary adipocytes from subcutaneous fat of three non-diabetic Caucasian female patients. Gene expression (mRNA/lncRNA) arrays and microRNA arrays, have been used to assess coding and non-coding RNA changes. We detected significantly deregulated mRNA/lncRNA and miRNA at low and high doses. Enrichment in “cancer” and “organismal injury and abnormalities” related pathways was found in response to the three products. Some long intergenic non-coding RNAs and small nucleolar RNAs were differentially expressed suggesting that bisphenols may also activate multiple cellular processes and epigenetic modifications. The analysis of upstream regulators of deregulated genes highlighted hormones or hormone-like chemicals suggesting that BPS and BPF can be suspected to interfere, just like BPA, with hormonal regulation and have to be considered as endocrine disruptors. All these results suggest that as BPA, its substitutes BPS and BPF should be used with the same restrictions. PMID:28628672

First somatic mutation of E2F1 in a critical DNA binding residue discovered in well-differentiated papillary mesothelioma of the peritoneum

PubMed Central

2011-01-01

Background Well differentiated papillary mesothelioma of the peritoneum (WDPMP) is a rare variant of epithelial mesothelioma of low malignancy potential, usually found in women with no history of asbestos exposure. In this study, we perform the first exome sequencing of WDPMP. Results WDPMP exome sequencing reveals the first somatic mutation of E2F1, R166H, to be identified in human cancer. The location is in the evolutionarily conserved DNA binding domain and computationally predicted to be mutated in the critical contact point between E2F1 and its DNA target. We show that the R166H mutation abrogates E2F1's DNA binding ability and is associated with reduced activation of E2F1 downstream target genes. Mutant E2F1 proteins are also observed in higher quantities when compared with wild-type E2F1 protein levels and the mutant protein's resistance to degradation was found to be the cause of its accumulation within mutant over-expressing cells. Cells over-expressing wild-type E2F1 show decreased proliferation compared to mutant over-expressing cells, but cell proliferation rates of mutant over-expressing cells were comparable to cells over-expressing the empty vector. Conclusions The R166H mutation in E2F1 is shown to have a deleterious effect on its DNA binding ability as well as increasing its stability and subsequent accumulation in R166H mutant cells. Based on the results, two compatible theories can be formed: R166H mutation appears to allow for protein over-expression while minimizing the apoptotic consequence and the R166H mutation may behave similarly to SV40 large T antigen, inhibiting tumor suppressive functions of retinoblastoma protein 1. PMID:21955916

Current topics in HIV-1 pathogenesis: The emergence of deregulated immuno-metabolism in HIV-infected subjects.

PubMed

Dagenais-Lussier, Xavier; Mouna, Aounallah; Routy, Jean-Pierre; Tremblay, Cecile; Sekaly, Rafick-Pierre; El-Far, Mohamed; Grevenynghe, Julien van

2015-12-01

HIV-1 infection results in long-lasting activation of the immune system including elevated production of pro-inflammatory cytokine/chemokines, and bacterial product release from gut into blood and tissue compartments, which are not fully restored by antiretroviral therapies. HIV-1 has also developed numerous strategies via viral regulatory proteins to hijack cell molecular mechanisms to enhance its own replication and dissemination. Here, we reviewed the relationship between viral proteins, immune activation/inflammation, and deregulated metabolism occurring in HIV-1-infected patients that ultimately dampens the protective innate and adaptive arms of immunity. Defining precisely the molecular mechanisms related to deregulated immuno-metabolism during HIV-1 infection could ultimately help in the development of novel clinical approaches to restore proper immune functions in these patients. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Deregulation of Rab and Rab Effector Genes in Bladder Cancer

PubMed Central

Ho, Joel R.; Chapeaublanc, Elodie; Kirkwood, Lisa; Nicolle, Remy; Benhamou, Simone; Lebret, Thierry; Allory, Yves; Southgate, Jennifer; Radvanyi, François; Goud, Bruno

2012-01-01

Growing evidence indicates that Rab GTPases, key regulators of intracellular transport in eukaryotic cells, play an important role in cancer. We analysed the deregulation at the transcriptional level of the genes encoding Rab proteins and Rab-interacting proteins in bladder cancer pathogenesis, distinguishing between the two main progression pathways so far identified in bladder cancer: the Ta pathway characterized by a high frequency of FGFR3 mutation and the carcinoma in situ pathway where no or infrequent FGFR3 mutations have been identified. A systematic literature search identified 61 genes encoding Rab proteins and 223 genes encoding Rab-interacting proteins. Transcriptomic data were obtained for normal urothelium samples and for two independent bladder cancer data sets corresponding to 152 and 75 tumors. Gene deregulation was analysed with the SAM (significant analysis of microarray) test or the binomial test. Overall, 30 genes were down-regulated, and 13 were up-regulated in the tumor samples. Five of these deregulated genes (LEPRE1, MICAL2, RAB23, STXBP1, SYTL1) were specifically deregulated in FGFR3-non-mutated muscle-invasive tumors. No gene encoding a Rab or Rab-interacting protein was found to be specifically deregulated in FGFR3-mutated tumors. Cluster analysis showed that the RAB27 gene cluster (comprising the genes encoding RAB27 and its interacting partners) was deregulated and that this deregulation was associated with both pathways of bladder cancer pathogenesis. Finally, we found that the expression of KIF20A and ZWINT was associated with that of proliferation markers and that the expression of MLPH, MYO5B, RAB11A, RAB11FIP1, RAB20 and SYTL2 was associated with that of urothelial cell differentiation markers. This systematic analysis of Rab and Rab effector gene deregulation in bladder cancer, taking relevant tumor subgroups into account, provides insight into the possible roles of Rab proteins and their effectors in bladder cancer pathogenesis. This approach is applicable to other group of genes and types of cancer. PMID:22724020

Inhibition of cholinesterase activity by extracts, fractions and compounds from Calceolaria talcana and C. integrifolia (Calceolariaceae: Scrophulariaceae).

PubMed

Cespedes, Carlos L; Muñoz, Evelyn; Salazar, Juan R; Yamaguchi, Lydia; Werner, Enrique; Alarcon, Julio; Kubo, Isao

2013-12-01

Extracts, fractions and compounds from Calceolaria talcana and C. integrifolia exhibited strong inhibitory effects of the activity of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes using the in vitro Ellman's method. The most active samples were from the ethyl acetate extract, which caused a mixed-type inhibition against AChE (69.8% and 79.5% at 100 and 200 μg/ml, respectively) and against BChE (98.5% and 99.8% at 100 and 200 μg/ml, respectively) and its major components verbascoside 8 (50.9% and 70.0% at 200 μg/ml, against AChE and BChE, respectively), martynoside 9, and fraction F-7 (which corresponds to a mixture of 8, 9, and other phenylethanoids and phenolics that remain unidentified) (80.2% and 85.3% at 100 and 200 μg/ml, against AChE, respectively and 99.1% and 99.7% at 100 and 200 μg/ml, against BChE, respectively) inhibited the acetylcholinesterase enzyme competitively. The most polar fraction F-5 from n-hexane extract (a mixture of naphthoquinones: 2-hydroxy-3-(1,1-dimethylallyl-1,4-naphthoquinone) 6, α-dunnione 7 and other polar compounds that remain unidentified) showed a mixed-type inhibition (71.5% and 72.1% against AChE and BChE at 200 μg/ml, respectively). Finally, the methanol-soluble residue presented a complex, mixed-type inhibition (39.9% and 67.9% against AChE and BChE at 200 μg/ml, respectively). The mixture F-3 with diterpenes was obtained from the n-hexane extract: (1,10-cyclopropyl-9-epi-ent-isopimarol) 1, 19-α-hydroxy-abietatriene 2, and F-4 a mixture of triterpenes α-lupeol 3, β-sitosterol 4, ursolic acid 5 together with a complex mixture of terpenes that did not show activity. In summary, extracts and natural compounds from C. talcana and C. integrifolia were isolated, identified and characterized as cholinesterase inhibitors.

Gene expression profiling of histologically normal breast tissue in females with human epidermal growth factor receptor 2‑positive breast cancer.

PubMed

Zubor, Pavol; Hatok, Jozef; Moricova, Petra; Kapustova, Ivana; Kajo, Karol; Mendelova, Andrea; Sivonova, Monika Kmetova; Danko, Jan

2015-02-01

Gene expression profile‑based taxonomy of breast cancer (BC) has been described as a significant breakthrough in comprehending the differences in the origin and behavior of cancer to allow individually tailored therapeutic approaches. In line with this, we hypothesized that the gene expression profile of histologically normal epithelium (HNEpi) could harbor certain genetic abnormalities predisposing breast tissue cells to develop human epidermal growth factor receptor 2 (HER2)‑positive BC. Thus, the aim of the present study was to assess gene expression in normal and BC tissue (BCTis) from patients with BC in order to establish its value as a potential diagnostic marker for cancer development. An array study evaluating a panel of 84 pathway‑ and disease‑specific genes in HER2‑positive BC and tumor‑adjacent HNEpi was performed using quantitative polymerase chain reaction in 12 patients using microdissected samples from frozen tissue. Common prognostic and predictive parameters of BC were assessed by immunohistochemistry and in situ hybridization. In the BCTis and HNEpi samples of 12 HER2‑positive subjects with BC, the expression of 2,016 genes was assessed. A total of 39.3% of genes were deregulated at a minimal two‑fold deregulation rate and 10.7% at a five‑fold deregulation rate in samples of HNEpi or BCTis. Significant differences in gene expression between BCTis and HNEpi samples were revealed for BCL2L2, CD44, CTSD, EGFR, ERBB2, ITGA6, NGFB, RPL27, SCBG2A1 and SCGB1D2 genes (P<0.05), as well as GSN, KIT, KLK5, SERPINB5 and STC2 genes (P<0.01). Insignificant differences (P<0.07) were observed for CCNA1, CLU, DLC1, GABRP and IL6 genes. The ontological gene analyses revealed that the majority of the deregulated genes in the HNEpi samples were part of the functional gene group directly associated with BC origin and prognosis. Functional analysis showed that the most frequent gene deregulations occurred in genes associated with apoptosis and cell cycle regulation in BCTis samples, and with angiogenesis, regulation of the cell cycle and transcriptional activity in HNEpi samples. The molecular profiling of HNEpi breast tissue revealed gene expression abnormalities that may represent potential markers of increased risk for HER2‑positive malignant transformation of breast tissue, and may be able to be employed as predictors of prognosis.

Integrative Genomic Analyses Yields Cell Cycle Regulatory Programs with Prognostic Value

PubMed Central

Cheng, Chao; Lou, Shaoke; Andrews, Erik H.; Ung, Matthew H.; Varn, Frederick S.

2016-01-01

Liposarcoma is the second most common form of sarcoma, which has been categorized into four molecular subtypes, which are associated with differential prognosis of patients. However, the transcriptional regulatory programs associated with distinct histological and molecular subtypes of liposarcoma have not been investigated. This study uses integrative analyses to systematically define the transcriptional regulatory programs associated with liposarcoma. Likewise, computational methods are used to identify regulatory programs associated with different liposarcoma subtypes as well as programs that are predictive of prognosis. Further analysis of curated gene sets was used to identify prognostic gene signatures. The integration of data from a variety sources including gene expression profiles, transcription factor (TF) binding data from ChIP-seq experiments, curated gene sets, and clinical information of patients indicated discrete regulatory programs (e.g., controlled by E2F1 and E2F4) with significantly different regulatory activity in one or multiple subtypes of liposarcoma with respect to normal adipose tissue. These programs were also shown to be prognostic, wherein liposarcoma patients with higher E2F4 or E2F1 activity associated with unfavorable prognosis. A total of 259 gene sets were significantly associated with patient survival in liposarcoma, among which >50% are involved in cell cycle and proliferation. PMID:26856934

Activation barriers for series of exothermic homologous reactions. V. Boron group diatomic species reactions

NASA Astrophysics Data System (ADS)

Blue, Alan S.; Belyung, David P.; Fontijn, Arthur

1997-09-01

Semiempirical configuration interaction (SECI) theory is used to predict activation barriers E, as defined by k(T)=ATn exp(-E/RT). Previously SECI has been applied to homologous series of oxidation reactions of s1, s2, and s2p1 metal atoms. Here it is extended to oxidation reactions of diatomic molecules containing one s2p1 atom. E values are calculated for the reactions of BH, BF, BCl, AlF, AlCl, AlBr, GaF, GaI, InCl, InBr, InI, TlF, TlCl, TlBr, and TlI with O2, CO2, SO2, or N2O. These values correlate with the sums of the ionization potentials and Σ-Π promotion energies of the former minus the electron affinities of the latter. In the earlier work n was chosen somewhat arbitrarily, which affected the absolute values of E. Here it is shown that examination of available experimental and theoretical results allows determination of the best values of n. Using this approach yields n=1.9 for the present series. For the seven reactions which have been studied experimentally, the average deviation of the SECI activation barrier prediction from experiment is 4.0 kJ mol-1. Energy barriers are calculated for another 52 reactions.

Tuning into single-band red upconversion luminescence in Yb(3+)/Ho(3+) activated nano-glass-ceramics through Ce(3+) doping.

PubMed

Chen, Daqin; Zhou, Yang; Wan, Zhongyi; Ji, Zhenguo; Huang, Ping

2015-03-28

Yb(3+)/Ho(3+) activated glass ceramics containing β-YF3 nanocrystals were successfully fabricated. The green ((5)S2/(5)F4→(5)I8) upconversion emission is dominant in the glass ceramics and is about 160 times stronger than that of the precursor glass, resulting from the partition of lanthanide activators into a low-phonon-energy crystalline lattice and the subsequent low probability of multi-phonon nonradiative relaxation from the (5)S2/(5)F4 and (5)I6 states to the lower ones. Upon the introduction of Ce(3+) ions into nano-glass-ceramics, two efficient cross-relaxation processes between Ho(3+) and Ce(3+), i.e., Ho(3+):(5)S2/(5)F4 + Ce(3+):(2)F5/2→Ho(3+):(5)F5 + Ce(3+):(2)F7/2 and Ho(3+):(5)I6 + Ce(3+):(2)F5/2→Ho(3+):(5)I7 + Ce(3+):(2)F7/2, are demonstrated to greatly suppress the population of the green-emitting (5)S2/(5)F4 state and to enhance the population of the red-emitting (5)F5 one, leading to the intense single-band red UC radiation of Ho(3+).

The NAMPT/E2F2/SIRT1 axis promotes proliferation and inhibits p53-dependent apoptosis in human melanoma cells.

PubMed

Zhao, Hailong; Tang, Weiwei; Chen, Xiaowen; Wang, Siyu; Wang, Xianyan; Xu, Haiyan; Li, Lijuan

2017-11-04

Melanoma is the most common primary malignant neoplasm in adults, causing more deaths than any other skin cancer, necessitating the development of new target-based approaches. Current evidence suggests SIRT1, the mammalian nicotinamide adenine dinucleotide (NAD + )-dependent protein deacetylase, and nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting NAD + biosynthetic enzyme, together comprise a novel systemic regulatory network to play a pivotal role in cell proliferation and apoptosis. Nevertheless, how the regulation of this cofactor interfaces with signal transduction network remains poorly understood in melanoma. Here, we report NAMPT is highly expressed in melanomaassociated with poor overall survival in patients. Pharmacological and genetic inhibition of NAMPT decreased NAD + levels and melanoma cell proliferation capacity, and NAMPT knockdown induced apoptosis through the activity of the tumor suppressor p53. Next, we demonstrate NAMPT regulates the transcription factor E2F family member 2 (E2F2) in the apoptosis process. Downstream, E2F2 control the mRNA and protein levels of SIRT1. Finally, we find NAMPT mediates the apoptosis resistance of melanoma cells through NAMPT-E2F2-SIRT1 axis, more than NAD + -driven transcriptional program. Accordingly, our results demonstrated that NAMPT is a prognostic marker in melanoma, and the identificationofNAMPT-E2F2-SIRT1 pathway establishes another link between NAMPT and apoptosis events in melanoma, with therapeutic implications for this deadly cancer. Copyright © 2017 Elsevier Inc. All rights reserved.

Inhibition of Delta-like 4 mediated signaling induces abortion in mice due to deregulation of decidual angiogenesis.

PubMed

García-Pascual, C M; Ferrero, H; Zimmermann, R C; Simón, C; Pellicer, A; Gómez, R

2014-07-01

To explore whether the Dll4/Notch1 pathway plays a key role in regulating the vascular endothelial growth factor (VEGF)/VEGF receptor 2 (VEGFR2) driven decidual angiogenesis and related pregnancy through induction of a tip/stalk phenotype. Progesterone-replaced ovariectomized pregnant mice received a single injection of YW152F (Dll4 blocking antibody, BAb) or placebo at embryonic day (E) 4.5. Animals were sacrificed at different time points; blood and uterus were collected for further analysis. Number of embryos and implantation site, uteri weight, and serum progesterone levels were assessed. Alterations in the tip/stalk phenotype were determined by quantitative immunofluorescent analysis of vascularization, Dll4 expression, cellular proliferation and apoptosis in uterine sections. Abrogation of Dll4 signaling leads to a promiscuous expression of Dll4, increased cell proliferation, apoptosis and vascularization at E 6.5. Such an abrogation was associated with a dramatic disruption of embryo growth and development starting at E 9.5. The observed promiscuous expression of Dll4 and the increase in cell proliferation, apoptosis and vascularization are events compatible with loss of the tip/stalk phenotype. Excessive (although very likely defective) decidual angiogenesis due to such vascular alterations is the most likely cause of subsequent interruption of embryo development and related pregnancy in Dll4 treated mice. Dll4 plays a key role in regulating decidual angiogenesis and related pregnancy through induction of a tip/stalk phenotype. Copyright © 2014 Elsevier Ltd. All rights reserved.

Roles for the Histone Modifying and Exchange Complex NuA4 in Cell Cycle Progression in Drosophila melanogaster.

PubMed

Flegel, Kerry; Grushko, Olga; Bolin, Kelsey; Griggs, Ellen; Buttitta, Laura

2016-07-01

Robust and synchronous repression of E2F-dependent gene expression is critical to the proper timing of cell cycle exit when cells transition to a postmitotic state. Previously NuA4 was suggested to act as a barrier to proliferation in Drosophila by repressing E2F-dependent gene expression. Here we show that NuA4 activity is required for proper cell cycle exit and the repression of cell cycle genes during the transition to a postmitotic state in vivo However, the delay of cell cycle exit caused by compromising NuA4 is not due to additional proliferation or effects on E2F activity. Instead NuA4 inhibition results in slowed cell cycle progression through late S and G2 phases due to aberrant activation of an intrinsic p53-independent DNA damage response. A reduction in NuA4 function ultimately produces a paradoxical cell cycle gene expression program, where certain cell cycle genes become derepressed in cells that are delayed during the G2 phase of the final cell cycle. Bypassing the G2 delay when NuA4 is inhibited leads to abnormal mitoses and results in severe tissue defects. NuA4 physically and genetically interacts with components of the E2F complex termed D: rosophila, R: bf, E: 2F A: nd M: yb/ M: ulti-vulva class B: (DREAM/MMB), and modulates a DREAM/MMB-dependent ectopic neuron phenotype in the posterior wing margin. However, this effect is also likely due to the cell cycle delay, as simply reducing Cdk1 is sufficient to generate a similar phenotype. Our work reveals that the major requirement for NuA4 in the cell cycle in vivo is to suppress an endogenous DNA damage response, which is required to coordinate proper S and G2 cell cycle progression with differentiation and cell cycle gene expression. Copyright © 2016 by the Genetics Society of America.

Roles for the Histone Modifying and Exchange Complex NuA4 in Cell Cycle Progression in Drosophila melanogaster

PubMed Central

Flegel, Kerry; Grushko, Olga; Bolin, Kelsey; Griggs, Ellen; Buttitta, Laura

2016-01-01

Robust and synchronous repression of E2F-dependent gene expression is critical to the proper timing of cell cycle exit when cells transition to a postmitotic state. Previously NuA4 was suggested to act as a barrier to proliferation in Drosophila by repressing E2F-dependent gene expression. Here we show that NuA4 activity is required for proper cell cycle exit and the repression of cell cycle genes during the transition to a postmitotic state in vivo. However, the delay of cell cycle exit caused by compromising NuA4 is not due to additional proliferation or effects on E2F activity. Instead NuA4 inhibition results in slowed cell cycle progression through late S and G2 phases due to aberrant activation of an intrinsic p53-independent DNA damage response. A reduction in NuA4 function ultimately produces a paradoxical cell cycle gene expression program, where certain cell cycle genes become derepressed in cells that are delayed during the G2 phase of the final cell cycle. Bypassing the G2 delay when NuA4 is inhibited leads to abnormal mitoses and results in severe tissue defects. NuA4 physically and genetically interacts with components of the E2F complex termed Drosophila, Rbf, E2F and Myb/Multi-vulva class B (DREAM/MMB), and modulates a DREAM/MMB-dependent ectopic neuron phenotype in the posterior wing margin. However, this effect is also likely due to the cell cycle delay, as simply reducing Cdk1 is sufficient to generate a similar phenotype. Our work reveals that the major requirement for NuA4 in the cell cycle in vivo is to suppress an endogenous DNA damage response, which is required to coordinate proper S and G2 cell cycle progression with differentiation and cell cycle gene expression. PMID:27184390

Identification of a unique nsaid, fluoro-loxoprofen with gastroprotective activity.

PubMed

Suemasu, Shintaro; Yamakawa, Naoki; Ishihara, Tomoaki; Asano, Teita; Tahara, Kayoko; Tanaka, Ken-ichiro; Matsui, Hirofumi; Okamoto, Yoshinari; Otsuka, Masami; Takeuchi, Koji; Suzuki, Hidekazu; Mizushima, Tohru

2012-12-01

We previously proposed that direct cytotoxicity of NSAIDs due to their membrane permeabilization activity, together with their ability to decrease gastric prostaglandin E(2), contributes to production of gastric lesions. Compared to loxoprofen (LOX), fluoro-loxoprofen (F-LOX) has much lower membrane permeabilization and gastric ulcerogenic activities but similar anti-inflammatory activity. In this study, we examined the mechanism for this low ulcerogenic activity in rats. Compared to LOX, the level of gastric mucosal cell death was lower following administration of F-LOX. However, the gastric level of prostaglandin E(2) was similar in response to treatment with the two NSAIDs. Oral pre-administration of F-LOX conferred protection against the formation of gastric lesions produced by subsequent administration of LOX and orally administered F-LOX resulted in a higher gastric pH value and mucus content. In the presence of a stimulant of gastric acid secretion, the difference in the ulcerogenic activity of F-LOX and LOX was less apparent. Furthermore, an increase in the mucus was observed in gastric cells cultured in the presence of F-LOX in a manner dependent of increase in the cellular level of cAMP. These results suggest that low ulcerogenic activity of F-LOX involves its both low direct cytotoxicity and protective effect against the development of gastric lesions. This protective effect seems to be mediated through an increase in a protective factor (mucus) and a decrease in an aggressive factor (acid). Copyright © 2012 Elsevier Inc. All rights reserved.

Ubiquitin-Dependent Regulation of the Mammalian Hippo Pathway: Therapeutic Implications for Cancer

PubMed Central

Nguyen, Thanh Hung

2018-01-01

The Hippo pathway serves as a key barrier for oncogenic transformation. It acts by limiting the activity of the proto-oncogenes YAP and TAZ. Reduced Hippo signaling and elevated YAP/TAZ activities are frequently observed in various types of tumors. Emerging evidence suggests that the ubiquitin system plays an important role in regulating Hippo pathway activity. Deregulation of ubiquitin ligases and of deubiquitinating enzymes has been implicated in increased YAP/TAZ activity in cancer. In this article, we review recent insights into the ubiquitin-mediated regulation of the mammalian Hippo pathway, its deregulation in cancer, and possibilities for targeting the Hippo pathway through the ubiquitin system. PMID:29673168

Equinoctial spread-F occurrence at low latitudes in different longitude sectors under moderate and high solar activity

NASA Astrophysics Data System (ADS)

Pietrella, M.; Pezzopane, M.; Fagundes, P. R.; de Jesus, R.; Supnithi, P.; Klinngam, S.; Ezquer, R. G.; Cabrera, M. A.

2017-11-01

A comparative study aimed to investigate the equatorial and low-latitude spread-F occurrences for moderate solar activity (MSA) and high solar activity (HSA), was carried out considering concurrent observations made in some ionospheric stations, which identify three separate longitudinal sectors: Chiang Mai (CGM; 18.8° N, 98.9° E, mag. Lat. 13.2° N) and Chumphon (CPN; 10.7° N, 99.4° E, mag. Lat. 3.2° N), Thailand; Palmas (PAL; 10.2° S, 311.8° E, mag. Lat. 0.9° S) and São José dos Campos (SJC; 23.2° S, 314.1° E, mag. Lat. 14.0° S), Brazil; Tucumán (TUC; 26.9° S, 294.6° E, mag. Lat. 16.8° S), Argentina. Spread-F phenomena recorded during the equinoctial months of September and October 2010, March and April 2011, for MSA, March and April 2014, September and October 2014, for HSA, were classified in two different modes: range spread-F (RSF) and frequency spread-F (FSF). The satellite trace (ST) occurrence was also investigated as possible precursor of spread-F events. When comparing the results of equatorial (CPN and PAL) and low-latitude (CGM, SJC, and TUC) stations, some common features independently of the solar activity emerge: (1) a prevalence of RSF signatures is observed in the time interval 20:00-03:00 LT, while FSF occurrences prevail in the time interval 03:00-06:00 LT; (2) STs are confirmed to be a possible precursor of RSF occurrences. For HSA, at equatorial latitudes, spread-F occurrences in the Thai sector (CPN) are higher than those observed in the Brazilian sector (PAL). When comparing the results of low-latitude stations of CGM, SJC, and TUC some unusual aspects characterizing the morphology of spread-F occurrences emerge: (1) contrary to the Thai and Argentine sectors, in the Brazilian sector (SJC), RSF and FSF appearances in September, for HSA, are observed with relatively long persistence times between about 03:00-06:00 LT and 01:00-03:00 LT respectively, while balanced RSF and FSF occurrences with short persistence times are observed for months for MSA; (2) a prevalence of FSF at CGM during the first half of September for MSA, never observed in the Brazilian and Argentine areas. During years of LSA and MSA common morphological aspects are found at CGM and SJC, that is a predominance of FSF, with the lowest persistence times characterizing SJC. This suggests that the low-latitude behaviour of spread-F occurrences, under different levels of solar activity, at least in the longitude sectors here analysed, can be to a some extent generalized.

Connective Tissue Growth Factor (CTGF) as a Regulator of Lactogenic Differentiation

DTIC Science & Technology

2009-06-09

1 1.62 Myeloid leukemia factor 1, Mlf1 1.57 ADAMTS-l4 1.55 E2F transcription factor, E2F2 1.44 Tensin 4 -1.5 BCL2/adenovirus E1B interacting... Mlf1 1.57 ADAMTS-l4 1.55 Ras homolog gene family, member B, RhoB 1.48 Cell Differentiation-associated Wingless-type MMTV integration site family...B, relB 1.92 Myeloid leukemia factor 1, Mlf1 1.57 Growth Factor, Catalytic Activity-associated Dual specificity protein phosphatase 8, Dusp8

Activation of translation complex eIF4F is essential for the genesis and maintenance of the malignant phenotype in human mammary epithelial cells.

PubMed

Avdulov, Svetlana; Li, Shunan; Michalek, Van; Burrichter, David; Peterson, Mark; Perlman, David M; Manivel, J Carlos; Sonenberg, Nahum; Yee, Douglas; Bitterman, Peter B; Polunovsky, Vitaly A

2004-06-01

Common human malignancies acquire derangements of the translation initiation complex, eIF4F, but their functional significance is unknown. Hypophosphorylated 4E-BP proteins negatively regulate eIF4F assembly by sequestering its mRNA cap binding component eIF4E, whereas hyperphosphorylation abrogates this function. We found that breast carcinoma cells harbor increases in the eIF4F constituent eIF4GI and hyperphosphorylation of 4E-BP1 which are two alterations that activate eIF4F assembly. Ectopic expression of eIF4E in human mammary epithelial cells enabled clonal expansion and anchorage-independent growth. Transfer of 4E-BP1 phosphorylation site mutants into breast carcinoma cells suppressed their tumorigenicity, whereas loss of these 4E-BP1 phosphorylation site mutants accompanied spontaneous reversion to a malignant phenotype. Thus, eIF4F activation is an essential component of the malignant phenotype in breast carcinoma.

Signalling in the epidermis: the E2F cell cycle regulatory pathway in epidermal morphogenesis, regeneration and transformation.

PubMed

Ivanova, Iordanka A; D'Souza, Sudhir J A; Dagnino, Lina

2005-01-01

The epidermis is the outermost layer in the skin, and it is the first line of defence against the environment. The epidermis also provides a barrier against loss of fluids and electrolytes, which is crucial for life. Essential in the maintenance of this tissue is its ability to continually self-renew and regenerate after injury. These two characteristics are critically dependent on the ability of the principal epidermal cell type, the keratinocyte, to proliferate and to respond to differentiation cues. Indeed, the epidermis is a multilayered tissue composed of keratinocyte stem cells and their differentiated progeny. Central for the control of cell proliferation is the E2F transcription factor regulatory network. This signaling network also includes cyclins, cdk, cdk inhibitors and the retinoblastoma (pRb) family of proteins. The biological importance of the E2F/pRb pathway is emphasized by the fact that a majority of human tumours exhibit alterations that disrupt the ability of pRb proteins to inhibit E2F, leading to permanent activation of the latter. Further, E2F is essential for normal epidermal regeneration after injury. Other member of the E2F signaling pathway are also involved in epidermal development and pathophysiology. Thus, whereas the pRb family of proteins is essential for epidermal morphogenesis, abnormal regulation of cyclins and E2F proteins results in tumorgenesis in this tissue. In this review, we discuss the role of each member of this important growth regulatory network in epidermal formation, homeostasis and carcinogenesis.

Signalling In The Epidermis: The E2f Cell Cycle Regulatory Pathway In Epidermal Morphogenesis, Regeneration And Transformation

PubMed Central

2005-01-01

The epidermis is the outermost layer in the skin, and it is the first line of defence against the environment. The epidermis also provides a barrier against loss of fluids and electrolytes, which is crucial for life. Essential in the maintenance of this tissue is its ability to continually self-renew and regenerate after injury. These two characteristics are critically dependent on the ability of the principal epidermal cell type, the keratinocyte, to proliferate and to respond to differentiation cues. Indeed, the epidermis is a multilayered tissue composed of keratinocyte stem cells and their differentiated progeny. Central for the control of cell proliferation is the E2F transcription factor regulatory network. This signaling network also includes cyclins, cdk, cdk inhibitors and the retinoblastoma (pRb) family of proteins. The biological importance of the E2F/pRb pathway is emphasized by the fact that a majority of human tumours exhibit alterations that disrupt the ability of pRb proteins to inhibit E2F, leading to permanent activation of the latter. Further, E2F is essential for normal epidermal regeneration after injury. Other member of the E2F signaling pathway are also involved in epidermal development and pathophysiology. Thus, whereas the pRb family of proteins is essential for epidermal morphogenesis, abnormal regulation of cyclins and E2F proteins results in tumorgenesis in this tissue. In this review, we discuss the role of each member of this important growth regulatory network in epidermal formation, homeostasis and carcinogenesis. PMID:15951853

The HPV-16 E7 oncoprotein induces centriole multiplication through deregulation of Polo-like kinase 4 expression

PubMed Central

2011-01-01

Background Infection with high-risk human papillomaviruses (HPVs) such as HPV-16 is intimately associated with squamous cell carcinomas (SCCs) of the anogenital tract and a subset of oropharyngeal carcinomas. Such lesions, including pre-invasive precursors, frequently show multipolar mitoses and aneuploidy. The high-risk HPV-16-encoded E7 oncoprotein has been shown to rapidly induce centrosome abnormalities thereby causing the formation of supernumerary mitotic spindle poles and increasing the risk for chromosome missegregation. HPV-16 E7 has been found to rapidly induce centriole overduplication, in part, through the simultaneous formation of more than one daughter centriole at single maternal centrioles (centriole multiplication). The precise molecular mechanism that underlies HPV-16 E7-induced centriole multiplication, however, remains poorly understood. Findings Here, we show that human keratinocytes engineered to stably express the HPV-16 E7 oncoprotein exhibit aberrant Polo-like kinase 4 (PLK4) protein expression at maternal centrioles. Real-time quantitative reverse transcriptase (qRT-PCR) analysis of these cells revealed an increase of PLK4 mRNA levels compared to control cells. Importantly, the ability of the HPV-16 E7 oncoprotein to induce centriole multiplication was found to correlate with its ability to activate the PLK4 promoter and to up-regulate PLK4 mRNA. Conclusions These results highlight the critical role of PLK4 transcriptional deregulation in centriole multiplication in HPV-16 E7-expressing cells. Our findings encourage further experiments to test transcriptional inhibitors or small molecules targeting PLK4 to prevent centriole abnormalities, mitotic infidelity and malignant progression in HPV-associated neoplasms and other tumors in which PLK4 regulation is disrupted. PMID:21609466

Anticholinesterase and antioxidant investigations of crude extracts, subsequent fractions, saponins and flavonoids of atriplex laciniata L.: potential effectiveness in Alzheimer's and other neurological disorders.

PubMed

Kamal, Zul; Ullah, Farhat; Ayaz, Muhammad; Sadiq, Abdul; Ahmad, Sajjad; Zeb, Anwar; Hussain, Abid; Imran, Muhammad

2015-04-01

Atriplex laciniata L. was investigated for phenolic, flavonoid contents, antioxidant, anticholinesterase activities, in an attempt to explore its effectiveness in Alzheimer's and other neurological disorders. Plant crude methanolic extract (Al.MeF), subsequent fractions; n-hexane (Al.HxF), chloroform (Al.CfF), ethyl acetate (Al.EaF), aqueous (Al.WtF), Saponins (Al.SPF) and Flavonoids (Al.FLVF) were investigated for DPPH, ABTS and H2O2 free radical scavenging activities. Further these extracts were subjected to acetylcholinesterase (AChE) & butyrylcholinesterase (BChE) inhibitory activities using Ellman's assay. Phenolic and Flavonoid contents were determined and expressed in mg Gallic acid GAE/g and Rutin RTE/g of samples respectively. In DPPH free radicals scavenging assay, Al.FLVF, Al.SPF and Al.MeF showed highest activity causing 89.41 ± 0.55, 83.37 ± 0.34 and 83.37 ± 0.34% inhibition of free radicals respectively at 1 mg/mL concentration. IC50 for these fractions were 33, 83 and 82 μg/mL respectively. Similarly, plant extracts showed high ABTS scavenging potential, i.e. Al.FLVF (90.34 ± 0.55), Al.CfF (83.42 ± 0.57), Al.MeF (81.49 ± 0.60) with IC50 of 30, 190 and 70 μg/ml respectively. further, H2O2 percent scavenging was highly appraised in Al.FLVF (91.29 ± 0.53, IC50 75), Al.SPF (85.35 ± 0.61, IC50 70) and Al.EaF (83.48 ± 0.67, IC50 270 μg/mL). All fractions exhibited concentration dependent AChE inhibitory activity as; Al.FLVF, 88.31 ± 0.57 (IC50 70 μg/mL), Al.SPF, 84.36 ± 0.64 (IC50 90 μg/mL), Al.MeF, 78.65 ± 0.70 (IC50 280 μg/mL), Al.EaF, 77.45 ± 0.46 (IC50 270 μg/mL) and Al.WtF 72.44 ± 0.58 (IC50 263 μg/mL) at 1 mg/mL. Likewise the percent BChE inhibitory activity was most obvious in Al.FLVF 85.46 ± 0.62 (IC50 100 μg/mL), Al.CfF 83.49 ± 0.46 (IC50 160 μg/mL), Al.MeF 82.68 ± 0.60 (IC50 220 μg/mL) and Al.SPF 80.37 ± 0.54 (IC50 120 μg/mL). These results stipulate that A. laciniata is enriched with phenolic and flavonoid contents that possess significant antioxidant and anticholinestrase effects. This provide pharmacological basis for the presence of compounds that may be effective in Alzheimer's and other neurological disorders.

Synthesis, fungicidal activity, structure-activity relationships (SARs) and density functional theory (DFT) studies of novel strobilurin analogues containing arylpyrazole rings.

PubMed

Liu, Yuanyuan; Lv, Kunzhi; Li, Yi; Nan, Qiuli; Xu, Jinyuan

2018-05-18

A series of novel strobilurin analogues (1a-1f, 2a-2e, 3a-3e) containing arylpyrazole rings were synthesized and characterized by NMR spectroscopy. The structures of 1f, 2b and 3b were also determined by single crystal X-ray diffraction analysis. These analogues were collected together with other twenty-eight similar compounds 4a-4f, 5a-5h, 6a-6h and 7a-7f from our previous studies, for in vitro bioassays and thorough structure-activity relationships (SARs) studies. Most compounds exhibited excellent-to-good fungicidal activity against Rhizoctonia solani, especially 5c, 7a, 6c, and 3b with 98.94%, 83.40%, 71.40% and 65.87% inhibition rates at 0.1 μg mL -1 , respectively, better than commercial pyraclostrobin. Comparative molecular field analysis (CoMFA) was employed to study three-dimensional quantitative structure-activity relationships (3D-QSARs). Density functional theory (DFT) calculation was also carried out to provide more information regarding SARs. The present work provided some hints for developing novel strobilurin fungicides.

Transposable Element Misregulation Is Linked to the Divergence between Parental piRNA Pathways in Drosophila Hybrids.

PubMed

Romero-Soriano, Valèria; Modolo, Laurent; Lopez-Maestre, Hélène; Mugat, Bruno; Pessia, Eugénie; Chambeyron, Séverine; Vieira, Cristina; Garcia Guerreiro, Maria Pilar

2017-06-01

Interspecific hybridization is a genomic stress condition that leads to the activation of transposable elements (TEs) in both animals and plants. In hybrids between Drosophila buzzatii and Drosophila koepferae, mobilization of at least 28 TEs has been described. However, the molecular mechanisms underlying this TE release remain poorly understood. To give insight on the causes of this TE activation, we performed a TE transcriptomic analysis in ovaries (notorious for playing a major role in TE silencing) of parental species and their F1 and backcrossed (BC) hybrids. We find that 15.2% and 10.6% of the expressed TEs are deregulated in F1 and BC1 ovaries, respectively, with a bias toward overexpression in both cases. Although differences between parental piRNA (Piwi-interacting RNA) populations explain only partially these results, we demonstrate that piRNA pathway proteins have divergent sequences and are differentially expressed between parental species. Thus, a functional divergence of the piRNA pathway between parental species, together with some differences between their piRNA pools, might be at the origin of hybrid instabilities and ultimately cause TE misregulation in ovaries. These analyses were complemented with the study of F1 testes, where TEs tend to be less expressed than in D. buzzatii. This can be explained by an increase in piRNA production, which probably acts as a defence mechanism against TE instability in the male germline. Hence, we describe a differential impact of interspecific hybridization in testes and ovaries, which reveals that TE expression and regulation are sex-biased. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

foF2 vs solar indices for the Rome station: Looking for the best general relation which is able to describe the anomalous minimum between cycles 23 and 24

NASA Astrophysics Data System (ADS)

Perna, L.; Pezzopane, M.

2016-10-01

Analyses of the dependence of the F2layer critical frequency, foF2, on five widely used solar activity indices (F10.7, Lym-α, MgII, R and EUV0.1-50)are carried out considering noon values manually validated at the ionospheric station of Rome (41.8°N, 12.5°E, Italy) between January 1976 and December 2013, a period of time covering the last three solar cycles and including the prolonged and anomalous minimum of solar cycle 23/24 (years 2008-2009). After applying a 1-year running mean to both foF2 and solar activity indices time series, a second order polynomial fitting proves to perform better than a linear one, and this is specifically due to the very low solar activity of the last solar minimum and to the remaining saturation effect characterizing the high solar activity. A comparison between observed and synthetic foF2 values, the latter calculated by using the analytical relations found for every index, and some considerations made on the R parameter introduced by Solomon et al. (2013), suggest that MgII is the best index to describe the dependence of foF2 on the solar activity. Three main reasons justify this result: (1) the good sensibility of MgII to the variations of foF2 for low solar activity; (2) the reduced saturation effect characterizing MgII at high solar activity; (3) the poor influence of the hysteresis effect characterizing MgII at medium solar activity. On the other hand, the F10.7 index, widely used as input parameter for numerous ionospheric models, does not represent properly the last minimum; specifically, it is not able to describe the variations of foF2 under a solar activity level of F10.7=82·10-22 [J Hz-1 s-1 m-2].

Importance of Maternal Diabetes on the Chronological Deregulation of the Intrauterine Development: An Experimental Study in Rat

PubMed Central

Salazar García, Marcela; Reyes Maldonado, Elba; Revilla Monsalve, María Cristina; Villavicencio Guzmán, Laura; Reyes López, Alfonso; Sánchez-Gómez, Concepción

2015-01-01

We investigated whether maternal diabetes induced in rats using streptozotocin (STZ) on Day 5 of pregnancy affects the intrauterine developmental timeline. A total of 30 pregnant Sprague-Dawley diabetic rats (DRs) and 20 control rats (CRs) were used to obtain 21-day fetuses (F21) and newborn (NB) pups. Gestational age, weight, and body size were recorded as were the maxillofacial morphometry and morphohistological characteristics of the limbs. In DRs, pregnancy continued for ∼1.7 days, and delivery occurred 23 days postcoitus (DPC). In this group, the number of pups was lower, and 13% had maxillofacial defects. F21 in the DR group had lower weights and were smaller; moreover, the morphological characteristics of the maxillofacial structures, derived from the neural crest, were discordant with their chronological gestational age, resembling 18- to 19-day-old fetuses. These deficiencies were counterbalanced in NB pups. We conclude that hyperglycemia, which results from maternal diabetes and precedes embryo implantation, deregulates the intrauterine developmental timeline, restricts embryo-fetal growth, and primarily delays the remodeling and maturation of the structures derived from neural crest cells. PMID:25756053

Analysis of a Soluble (UreD:UreF:UreG)2 Accessory Protein Complex and Its Interactions with Klebsiella aerogenes Urease by Mass Spectrometry

NASA Astrophysics Data System (ADS)

Farrugia, Mark A.; Han, Linjie; Zhong, Yueyang; Boer, Jodi L.; Ruotolo, Brandon T.; Hausinger, Robert P.

2013-09-01

Maturation of the nickel-containing urease of Klebsiella aerogenes is facilitated by the UreD, UreF, and UreG accessory proteins along with the UreE metallo-chaperone. A fusion of the maltose binding protein and UreD (MBP-UreD) was co-isolated with UreF and UreG in a soluble complex possessing a (MBP-UreD:UreF:UreG)2 quaternary structure. Within this complex a UreF:UreF interaction was identified by chemical cross-linking of the amino termini of its two UreF protomers, as shown by mass spectrometry of tryptic peptides. A pre-activation complex was formed by the interaction of (MBP-UreD:UreF:UreG)2 and urease. Mass spectrometry of intact protein species revealed a pathway for synthesis of the urease pre-activation complex in which individual hetero-trimer units of the (MBP-UreD:UreF:UreG)2 complex bind to urease. Together, these data provide important new insights into the structures of protein complexes associated with urease activation.

Antibodies derived from a toxoid MEFA (multiepitope fusion antigen) show neutralizing activities against heat-labile toxin (LT), heat-stable toxins (STa, STb), and Shiga toxin 2e (Stx2e) of porcine enterotoxigenic Escherichia coli (ETEC).

PubMed

Rausch, Dana; Ruan, Xiaosai; Nandre, Rahul; Duan, Qiangde; Hashish, Emad; Casey, Thomas A; Zhang, Weiping

2017-04-01

Enterotoxigenic Escherichia coli (ETEC) strains are the main cause of diarrhea in pigs. Pig diarrhea especially post-weaning diarrhea remains one of the most important swine diseases. ETEC bacterial fimbriae including K88, F18, 987P, K99 and F41 promote bacterial attachment to intestinal epithelial cells and facilitate ETEC colonization in pig small intestine. ETEC enterotoxins including heat-labile toxin (LT) and heat-stable toxins type Ia (porcine-type STa) and type II (STb) stimulate fluid hyper-secretion, leading to watery diarrhea. Blocking bacteria colonization and/or neutralizing enterotoxicity of ETEC toxins are considered effective prevention against ETEC diarrhea. In this study, we applied the MEFA (multiepitope fusion antigen) strategy to create toxoid MEFAs that carried antigenic elements of ETEC toxins, and examined for broad antitoxin immunogenicity in a murine model. By embedding STa toxoid STa P12F (NTFYCCELCCNFACAGCY), a STb epitope (KKDLCEHY), and an epitope of Stx2e A subunit (QSYVSSLN) into the A1 peptide of a monomeric LT toxoid (LT R192G ), two toxoid MEFAs, 'LT R192G -STb-Stx2e-STa P12F ' and 'LT R192G -STb-Stx2e-3xSTa P12F ' which carried three copies of STa P12F , were constructed. Mice intraperitoneally immunized with each toxoid MEFA developed IgG antibodies to all four toxins. Induced antibodies showed in vitro neutralizing activities against LT, STa, STb and Stx2e toxins. Moreover, suckling piglets born by a gilt immunized with 'LT R192G -STb-Stx2e-3xSTa P12F ' were protected when challenged with ETEC strains, whereas piglets born by a control gilt developed diarrhea. Results from this study showed that the toxoid MEFA induced broadly antitoxin antibodies, and suggested potential application of the toxoid MEFA for developing a broad-spectrum vaccine against ETEC diarrhea in pigs. Copyright © 2016 Elsevier B.V. All rights reserved.

RNA-Sequencing of Primary Retinoblastoma Tumors Provides New Insights and Challenges Into Tumor Development.

PubMed

Elchuri, Sailaja V; Rajasekaran, Swetha; Miles, Wayne O

2018-01-01

Retinoblastoma is rare tumor of the retina caused by the homozygous loss of the Retinoblastoma 1 tumor suppressor gene (RB1). Loss of the RB1 protein, pRB, results in de-regulated activity of the E2F transcription factors, chromatin changes and developmental defects leading to tumor development. Extensive microarray profiles of these tumors have enabled the identification of genes sensitive to pRB disruption, however, this technology has a number of limitations in the RNA profiles that they generate. The advent of RNA-sequencing has enabled the global profiling of all of the RNA within the cell including both coding and non-coding features and the detection of aberrant RNA processing events. In this perspective, we focus on discussing how RNA-sequencing of rare Retinoblastoma tumors will build on existing data and open up new area's to improve our understanding of the biology of these tumors. In particular, we discuss how the RB-research field may be to use this data to determine how RB1 loss results in the expression of; non-coding RNAs, causes aberrant RNA processing events and how a deeper analysis of metabolic RNA changes can be utilized to model tumor specific shifts in metabolism. Each section discusses new opportunities and challenges associated with these types of analyses and aims to provide an honest assessment of how understanding these different processes may contribute to the treatment of Retinoblastoma.

The role of the Hippo pathway in human disease and tumorigenesis

PubMed Central

2014-01-01

Understanding the molecular nature of human cancer is essential to the development of effective and personalized therapies. Several different molecular signal transduction pathways drive tumorigenesis when deregulated and respond to different types of therapeutic interventions. The Hippo signaling pathway has been demonstrated to play a central role in the regulation of tissue and organ size during development. The deregulation of Hippo signaling leads to a concurrent combination of uncontrolled cellular proliferation and inhibition of apoptosis, two key hallmarks in cancer development. The molecular nature of this pathway was first uncovered in Drosophila melanogaster through genetic screens to identify regulators of cell growth and cell division. The pathway is strongly conserved in humans, rendering Drosophila a suitable and efficient model system to better understand the molecular nature of this pathway. In the present study, we review the current understanding of the molecular mechanism and clinical impact of the Hippo pathway. Current studies have demonstrated that a variety of deregulated molecules can alter Hippo signaling, leading to the constitutive activation of the transcriptional activator YAP or its paralog TAZ. Additionally, the Hippo pathway integrates inputs from a number of growth signaling pathways, positioning the Hippo pathway in a central role in the regulation of tissue size. Importantly, deregulated Hippo signaling is frequently observed in human cancers. YAP is commonly activated in a number of in vitro and in vivo models of tumorigenesis, as well as a number of human cancers. The common activation of YAP in many different tumor types provides an attractive target for potential therapeutic intervention. PMID:25097728

Dynamic Testing of Signal Transduction Deregulation During Breast Cancer Initiation

DTIC Science & Technology

2012-07-01

Std. Z39.18 Victoria Seewaldt, M.D. Dynamic Testing of Signal Transduction Deregulation During Breast Cancer Initiation Duke University Durham...attomole- zeptomole range. Internal dilution curves insure a high-dynamic calibration range. DU -26 8L DU -26 6L DU -29 5R DU -22 9.2 L DU...3: Nanobiosensor technology is translated to test for pathway deregulation in RPFNA cytology obtained from 10 high-risk women with cytological

Cyclin E-Mediated Human Proopiomelanocortin Regulation as a Therapeutic Target for Cushing Disease.

PubMed

Liu, Ning-Ai; Araki, Takako; Cuevas-Ramos, Daniel; Hong, Jiang; Ben-Shlomo, Anat; Tone, Yukiko; Tone, Masahide; Melmed, Shlomo

2015-07-01

Cushing disease, due to pituitary corticotroph tumor ACTH hypersecretion, drives excess adrenal cortisol production with adverse morbidity and mortality. Loss of glucocorticoid negative feedback on the hypothalamic-pituitary-adrenal axis leads to autonomous transcription of the corticotroph precursor hormone proopiomelanocortin (POMC), consequent ACTH overproduction, and adrenal hypercortisolism. We previously reported that R-roscovitine (CYC202, seliciclib), a 2,6,9-trisubstituted purine analog, suppresses cyclin-dependent-kinase 2/cyclin E and inhibits ACTH in mice and zebrafish. We hypothesized that intrapituitary cyclin E signaling regulates corticotroph tumor POMC transcription independently of cell cycle progression. The aim was to investigate whether R-roscovitine inhibits human ACTH in corticotroph tumors by targeting the cyclin-dependent kinase 2/cyclin E signaling pathway. Primary cell cultures of surgically resected human corticotroph tumors were treated with or without R-roscovitine, ACTH measured by RIA and quantitative PCR, and/or Western blot analysis performed to investigate ACTH and lineage-specific transcription factors. Cyclin E and E2F transcription factor 1 (E2F1) small interfering RNA (siRNA) transfection was performed in murine corticotroph tumor AtT20 cells to elucidate mechanisms for drug action. POMC gene promoter activity in response to R-roscovitine treatment was analyzed using luciferase reporter and chromatin immunoprecipitation assays. R-roscovitine inhibits human corticotroph tumor POMC and Tpit/Tbx19 transcription with decreased ACTH expression. Cyclin E and E2F1 exhibit reciprocal positive regulation in corticotroph tumors. R-roscovitine disrupts E2F1 binding to the POMC gene promoter and suppresses Tpit/Tbx19 and other lineage-specific POMC transcription cofactors via E2F1-dependent and -independent pathways. R-roscovitine inhibits human pituitary corticotroph tumor ACTH by targeting the cyclin E/E2F1 pathway. Pituitary cyclin E/E2F1 signaling is a previously unappreciated molecular mechanism underlying neuroendocrine regulation of the hypothalamic-pituitary-adrenal axis, providing a subcellular therapeutic target for small molecule cyclin-dependent kinase 2 inhibitors of pituitary ACTH-dependent hypercortisolism, ie, Cushing disease.

Nuclear localization of pyruvate dehydrogenase complex-E2 (PDC-E2), a mitochondrial enzyme, and its role in signal transducer and activator of transcription 5 (STAT5)-dependent gene transcription.

PubMed

Chueh, Fu-Yu; Leong, King-Fu; Cronk, Robert J; Venkitachalam, Srividya; Pabich, Samantha; Yu, Chao-Lan

2011-07-01

STAT (signal transducer and activator of transcription) proteins play a critical role in cellular response to a wide variety of cytokines and growth factors by regulating specific nuclear genes. STAT-dependent gene transcription can be finely tuned through the association with co-factors in the nucleus. We showed previously that STAT5 (including 5a and 5b) specifically interacts with a mitochondrial enzyme PDC-E2 (E2 subunit of pyruvate dehydrogenase complex) in both leukemic T cells and cytokine-stimulated cells. However, the functional significance of this novel association remains largely unknown. Here we report that PDC-E2 may function as a co-activator in STAT5-dependent nuclear gene expression. Subcellular fractionation analysis revealed that a substantial amount of PDC-E2 was constitutively present in the nucleus of BaF3, an interleukin-3 (IL-3)-dependent cell line. IL-3-induced tyrosine-phosphorylated STAT5 associated with nuclear PDC-E2 in co-immunoprecipitation analysis. These findings were confirmed by confocal immunofluorescence microscopy showing constant nuclear localization of PDC-E2 and its co-localization with STAT5 after IL-3 stimulation. Similar to mitochondrial PDC-E2, nuclear PDC-E2 was lipoylated and associated with PDC-E1. Overexpression of PDC-E2 in BaF3 cells augmented IL-3-induced STAT5 activity as measured by reporter assay with consensus STAT5-binding sites. Consistent with the reporter data, PDC-E2 overexpression in BaF3 cells led to elevated mRNA levels of endogenous SOCS3 (suppressor of cytokine signaling 3) gene, a known STAT5 target. We further identified two functional STAT5-binding sites in the SOCS3 gene promoter important for its IL-3-inducibility. The observation that both cis-acting elements were essential to detect the stimulatory effect by PDC-E2 strongly supports the role of PDC-E2 in up-regulating the transactivating ability of STAT5. All together, our results reveal a novel function of PDC-E2 in the nucleus. It also raises the possibility of nuclear-mitochondrial crosstalk through the interaction between STAT5 and PDC-E2. Copyright © 2011 Elsevier Inc. All rights reserved.

Nuclear localization of pyruvate dehydrogenase complex-E2 (PDC-E2), a mitochondrial enzyme, and its role in signal transducer and activator of transcription 5 (STAT5)-dependent gene transcription

PubMed Central

Chueh, Fu-Yu; Leong, King-Fu; Cronk, Robert J.; Venkitachalam, Srividya; Pabich, Samantha; Yu, Chao-Lan

2011-01-01

STAT (signal transducer and activator of transcription) proteins play a critical role in cellular response to a wide variety of cytokines and growth factors by regulating specific nuclear genes. STAT-dependent gene transcription can be finely tuned through the association with cofactors in the nucleus. We showed previously that STAT5 (including 5a and 5b) specifically interacts with a mitochondrial enzyme PDC-E2 (E2 subunit of pyruvate dehydrogenase complex) in both leukemic T cells and cytokine-stimulated cells. However, the functional significance of this novel association remains largely unknown. Here we report that PDC-E2 may function as a co-activator in STAT5-dependent nuclear gene expression. Subcellular fractionation analysis revealed that a substantial amount of PDC-E2 was constitutively present in the nucleus of BaF3, an interleukin-3 (IL-3)-dependent cell line. IL-3-induced tyrosine-phosphorylated STAT5 associated with nuclear PDC-E2 in co-immunoprecipitation analysis. These findings were confirmed by confocal immunofluorescence microscopy showing constant nuclear localization of PDC-E2 and its co-localization with STAT5 after IL-3 stimulation. Similar to mitochondrial PDC-E2, nuclear PDC-E2 was lipoylated and associated with PDC-E1. Overexpression of PDC-E2 in BaF3 cells augmented IL-3-induced STAT5 activity as measured by reporter assay with consensus STAT5-binding sites. Consistent with the reporter data, PDC-E2 overexpression in BaF3 cells led to elevated mRNA levels of endogenous SOCS3 (suppressor of cytokine signaling 3) gene, a known STAT5 target. We further identified two functional STAT5-binding sites in the SOCS3 gene promoter important for its IL-3-inducibility. The observation that both cis-acting elements were essential to detect the stimulatory effect by PDC-E2 strongly supports the role of PDC-E2 in up-regulating the transactivating ability of STAT5. All together, our results reveal a novel function of PDC-E2 in the nucleus. It also raises the possibility of nuclear-mitochondrial crosstalk through the interaction between STAT5 and PDC-E2. PMID:21397011

Na[superscript +] binding to meizothrombin desF1

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

Papaconstantinou, M.E.; Gandhi, P.S.; Chen, Z.

2009-06-10

Meizothrombin is the physiologically active intermediate generated by a single cleavage of prothrombin at R320 to separate the A and B chains. Recent evidence has suggested that meizothrombin, like thrombin, is a Na{sup +}-activated enzyme. In this study we present the first X-ray crystal structure of human meizothrombin desF1 solved in the presence of the active site inhibitor PPACK at 2.1 {angstrom} resolution. The structure reveals a Na{sup +} binding site whose architecture is practically identical to that of human thrombin. Stopped-flow measurements of Na{sup +} binding to meizothrombin desF1 document a slow phase of fluorescence change with a kmore » obs decreasing hyperbolically with increasing [Na{sup +}], consistent with the existence of three conformations in equilibrium, E*, E and E:Na{sup +}, as for human thrombin. Evidence that meizothrombin exists in multiple conformations provides valuable new information for studies of the mechanism of prothrombin activation.« less

Estimation of the fraction of absorbed photosynthetically active radiation (fPAR) in maize canopies using LiDAR data and hyperspectral imagery.

PubMed

Qin, Haiming; Wang, Cheng; Zhao, Kaiguang; Xi, Xiaohuan

2018-01-01

Accurate estimation of the fraction of absorbed photosynthetically active radiation (fPAR) for maize canopies are important for maize growth monitoring and yield estimation. The goal of this study is to explore the potential of using airborne LiDAR and hyperspectral data to better estimate maize fPAR. This study focuses on estimating maize fPAR from (1) height and coverage metrics derived from airborne LiDAR point cloud data; (2) vegetation indices derived from hyperspectral imagery; and (3) a combination of these metrics. Pearson correlation analyses were conducted to evaluate the relationships among LiDAR metrics, hyperspectral metrics, and field-measured fPAR values. Then, multiple linear regression (MLR) models were developed using these metrics. Results showed that (1) LiDAR height and coverage metrics provided good explanatory power (i.e., R2 = 0.81); (2) hyperspectral vegetation indices provided moderate interpretability (i.e., R2 = 0.50); and (3) the combination of LiDAR metrics and hyperspectral metrics improved the LiDAR model (i.e., R2 = 0.88). These results indicate that LiDAR model seems to offer a reliable method for estimating maize fPAR at a high spatial resolution and it can be used for farmland management. Combining LiDAR and hyperspectral metrics led to better performance of maize fPAR estimation than LiDAR or hyperspectral metrics alone, which means that maize fPAR retrieval can benefit from the complementary nature of LiDAR-detected canopy structure characteristics and hyperspectral-captured vegetation spectral information.

E2F1 and E2F2 induction in response to DNA damage preserves genomic stability in neuronal cells.

PubMed

Castillo, Daniela S; Campalans, Anna; Belluscio, Laura M; Carcagno, Abel L; Radicella, J Pablo; Cánepa, Eduardo T; Pregi, Nicolás

2015-01-01

E2F transcription factors regulate a wide range of biological processes, including the cellular response to DNA damage. In the present study, we examined whether E2F family members are transcriptionally induced following treatment with several genotoxic agents, and have a role on the cell DNA damage response. We show a novel mechanism, conserved among diverse species, in which E2F1 and E2F2, the latter specifically in neuronal cells, are transcriptionally induced after DNA damage. This upregulation leads to increased E2F1 and E2F2 protein levels as a consequence of de novo protein synthesis. Ectopic expression of these E2Fs in neuronal cells reduces the level of DNA damage following genotoxic treatment, while ablation of E2F1 and E2F2 leads to the accumulation of DNA lesions and increased apoptotic response. Cell viability and DNA repair capability in response to DNA damage induction are also reduced by the E2F1 and E2F2 deficiencies. Finally, E2F1 and E2F2 accumulate at sites of oxidative and UV-induced DNA damage, and interact with γH2AX DNA repair factor. As previously reported for E2F1, E2F2 promotes Rad51 foci formation, interacts with GCN5 acetyltransferase and induces histone acetylation following genotoxic insult. The results presented here unveil a new mechanism involving E2F1 and E2F2 in the maintenance of genomic stability in response to DNA damage in neuronal cells.

E2F1 and E2F2 induction in response to DNA damage preserves genomic stability in neuronal cells

PubMed Central

Castillo, Daniela S; Campalans, Anna; Belluscio, Laura M; Carcagno, Abel L; Radicella, J Pablo; Cánepa, Eduardo T; Pregi, Nicolás

2015-01-01

E2F transcription factors regulate a wide range of biological processes, including the cellular response to DNA damage. In the present study, we examined whether E2F family members are transcriptionally induced following treatment with several genotoxic agents, and have a role on the cell DNA damage response. We show a novel mechanism, conserved among diverse species, in which E2F1 and E2F2, the latter specifically in neuronal cells, are transcriptionally induced after DNA damage. This upregulation leads to increased E2F1 and E2F2 protein levels as a consequence of de novo protein synthesis. Ectopic expression of these E2Fs in neuronal cells reduces the level of DNA damage following genotoxic treatment, while ablation of E2F1 and E2F2 leads to the accumulation of DNA lesions and increased apoptotic response. Cell viability and DNA repair capability in response to DNA damage induction are also reduced by the E2F1 and E2F2 deficiencies. Finally, E2F1 and E2F2 accumulate at sites of oxidative and UV-induced DNA damage, and interact with γH2AX DNA repair factor. As previously reported for E2F1, E2F2 promotes Rad51 foci formation, interacts with GCN5 acetyltransferase and induces histone acetylation following genotoxic insult. The results presented here unveil a new mechanism involving E2F1 and E2F2 in the maintenance of genomic stability in response to DNA damage in neuronal cells. PMID:25892555

1E7-03, a low MW compound targeting host protein phosphatase-1, inhibits HIV-1 transcription

PubMed Central

Ammosova, Tatyana; Platonov, Maxim; Ivanov, Andrei; Kont, Yasemin Saygideğer; Kumari, Namita; Kehn-Hall, Kylene; Jerebtsova, Marina; Kulkarni, Amol A; Üren, Aykut; Kovalskyy, Dmytro; Nekhai, Sergei

2014-01-01

Background and Purpose HIV-1 transcription is activated by the Tat protein which recruits the cyclin-dependent kinase CDK9/cyclin T1 to TAR RNA. Tat binds to protein phosphatase-1 (PP1) through the Q35VCF38 sequence and translocates PP1 to the nucleus. PP1 dephosphorylates CDK9 and activates HIV-1 transcription. We have synthesized a low MW compound 1H4, that targets PP1 and prevents HIV-1 Tat interaction with PP1 and inhibits HIV-1 gene transcription. Here, we report our further work with the 1H4-derived compounds and analysis of their mechanism of action. Experimental Approach Using the 1H4-PP1 complex as a model, we iteratively designed and synthesized follow-up libraries that were analysed for the inhibition of HIV-1 transcription and toxicity. We also confirmed the mechanism of action of the PP1-targeting molecules by determining the affinity of binding of these molecules to PP1, by analysing their effects on PP1 activity, disruption of PP1 binding to Tat and shuttling of PP1 to the nucleus. Key Results We identified a tetrahydroquinoline derivative, compound 7, which disrupted the interaction of Tat with PP1. We further optimized compound 7 and obtained compound 7c, renamed 1E7-03, which inhibited HIV-1 with low IC50 (fivefold lower than the previously reported compound, 1H4), showed no cytotoxicity and displayed a plasma half-life greater than 8 h in mice. 1E7-03 bound to PP1 in vitro and prevented shuttling of PP1 into the nucleus. Conclusions and Implications Our study shows that low MW compounds that functionally mimic the PP1-binding RVxF peptide can inhibit HIV-1 transcription by deregulating PP1. PMID:25073485

Aneuploidy-Dependent Massive Deregulation of the Cellular Transcriptome and Apparent Divergence of the Wnt/β-catenin Signaling Pathway in Human Rectal Carcinomas

PubMed Central

Grade, Marian; Ghadimi, B. Michael; Varma, Sudhir; Simon, Richard; Wangsa, Danny; Barenboim-Stapleton, Linda; Liersch, Torsten; Becker, Heinz; Ried, Thomas; Difilippantonio, Michael J.

2016-01-01

To identify genetic alterations underlying rectal carcinogenesis, we used global gene expression profiling of a series of 17 locally advanced rectal adenocarcinomas and 20 normal rectal mucosa biopsies on oligonucleotide arrays. A total of 351 genes were differentially expressed (P < 1.0e–7) between normal rectal mucosa and rectal carcinomas, 77 genes had a >5-fold difference, and 85 genes always had at least a 2-fold change in all of the matched samples. Twelve genes satisfied all three of these criteria. Altered expression of genes such as PTGS2 (COX-2), WNT1, TGFB1, VEGF, and MYC was confirmed, whereas our data for other genes, like PPARD and LEF1, were inconsistent with previous reports. In addition, we found deregulated expression of many genes whose involvement in rectal carcinogenesis has not been reported. By mapping the genomic imbalances in the tumors using comparative genomic hybridization, we could show that DNA copy number gains of recurrently aneuploid chromosome arms 7p, 8q, 13q, 18q, 20p, and 20q correlated significantly with their average chromosome arm expression profile. Taken together, our results show that both the high-level, significant transcriptional deregulation of specific genes and general modification of the average transcriptional activity of genes residing on aneuploid chromosomes coexist in rectal adenocarcinomas. PMID:16397240

Transposable Elements in Human Cancer: Causes and Consequences of Deregulation.

PubMed

Anwar, Sumadi Lukman; Wulaningsih, Wahyu; Lehmann, Ulrich

2017-05-04

Transposable elements (TEs) comprise nearly half of the human genome and play an essential role in the maintenance of genomic stability, chromosomal architecture, and transcriptional regulation. TEs are repetitive sequences consisting of RNA transposons, DNA transposons, and endogenous retroviruses that can invade the human genome with a substantial contribution in human evolution and genomic diversity. TEs are therefore firmly regulated from early embryonic development and during the entire course of human life by epigenetic mechanisms, in particular DNA methylation and histone modifications. The deregulation of TEs has been reported in some developmental diseases, as well as for different types of human cancers. To date, the role of TEs, the mechanisms underlying TE reactivation, and the interplay with DNA methylation in human cancers remain largely unexplained. We reviewed the loss of epigenetic regulation and subsequent genomic instability, chromosomal aberrations, transcriptional deregulation, oncogenic activation, and aberrations of non-coding RNAs as the potential mechanisms underlying TE deregulation in human cancers.

Transposable Elements in Human Cancer: Causes and Consequences of Deregulation

PubMed Central

Anwar, Sumadi Lukman; Wulaningsih, Wahyu; Lehmann, Ulrich

2017-01-01

Transposable elements (TEs) comprise nearly half of the human genome and play an essential role in the maintenance of genomic stability, chromosomal architecture, and transcriptional regulation. TEs are repetitive sequences consisting of RNA transposons, DNA transposons, and endogenous retroviruses that can invade the human genome with a substantial contribution in human evolution and genomic diversity. TEs are therefore firmly regulated from early embryonic development and during the entire course of human life by epigenetic mechanisms, in particular DNA methylation and histone modifications. The deregulation of TEs has been reported in some developmental diseases, as well as for different types of human cancers. To date, the role of TEs, the mechanisms underlying TE reactivation, and the interplay with DNA methylation in human cancers remain largely unexplained. We reviewed the loss of epigenetic regulation and subsequent genomic instability, chromosomal aberrations, transcriptional deregulation, oncogenic activation, and aberrations of non-coding RNAs as the potential mechanisms underlying TE deregulation in human cancers. PMID:28471386

The controversial role of forkhead box F2 (FOXF2) transcription factor in breast cancer.

PubMed

Lo, Pang-Kuo

2017-01-01

Deregulating the subcellular localization, functions and expression of Forkhead box (FOX) transcription factors that are critically involved in embryonic development and multiple biological processes is known to result in the development and progression of diseases, in particular cancer. Human FOXF transcription factors, including FOXF1 and FOXF2, are a subfamily of the FOX gene family. The recent findings from ours and others have linked FOXF2 to breast cancer development and progression. Our studies have shown that FOXF2 acts as a tumor-suppressive inhibitor of DNA replication in luminal and HER2-positive breast cancers and as an oncogenic activator of the epithelial-mesenchymal transition (EMT) in triple-negative/basal-like breast cancers (TN/BLBC), suggesting that FOXF2 plays a dual role in breast cancer. However, studies from Feng's research group have pointed out an opposite role of FOXF2 in TN/BLBC, which acts as an inhibitor of the EMT and as a promoter of cell proliferation in TN/BLBC. These discrepancies between our and Feng's studies have caused controversy in the role of FOXF2 in breast cancer. This article reviews both studies and discusses what causes might have led to these inconsistencies as well as what future experiments are needed to solve this debate.

Inhibitory effect of fermented Arctium lappa fruit extract on the IgE-mediated allergic response in RBL‑2H3 cells.

PubMed

Yoo, Jae-Myung; Yang, Ju Hye; Yang, Hye Jin; Cho, Won-Kyung; Ma, Jin Yeul

2016-02-01

Arctium lappa fruit has been used in traditional medicine, and it is known to exert beneficial effects, such as antioxidant, anti-inflammatory and anticancer effects. However, the effects of the Arctium lappa fruit on the allergic response remain unknown. In this study, we evaluated the anti-allergic effects of Arctium lappa fruit extract (AFE) and its fermented form (F-AFE) using immunoglobulin E (IgE)-activated RBL‑2H3 cells. To investigate the anti-allergic effects of AFE or F-AFE, we examined the release of β-hexosaminidase, a key biomarker of degranulation during an allergic reaction, and the production of pro-inflammatory mediators, such as tumor necrosis factor-α (TNF-α) and prostaglandin E2 (PGE2) in the cells treated with or without the above-mentioned extracts. AFE weakly inhibited the release of β-hexosaminidase, whereas F-AFE significantly suppressed the release of β-hexosaminidase in a dose-dependent manner. Consistently, F-AFE suppressed the production of TNF-α and PGE2 in a dose-dependent manner. F-AFE exerted an inhibitory effect on the production of β-hexosaminidase, TNF-α and PGE2 with an IC50 value of 30.73, 46.96 and 36.27 µg/ml, respectively. Furthermore, F-AFE inhibited the phosphorylation of Lyn, Fyn and Syk, which are involved in the FcεRI signaling pathway, that of phosphoinositide phospholipase C (PLC)γ1/2 and protein kinase C (PKC)δ, which are associated with the degranulation process, as well as that of extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal kinase 1/2 (JNK), p38 and Akt, which are associated with cytokine expression. In the late phase, F-AFE partially suppressed the phosphorylation of cytosolic phospholipase A2 (cPLA2), but not the expression of cyclooxygenase (COX)-2. To compare and identify the major components of the two extracts, we used high-performance liquid chromatography. The levels of arctigenin, one of the major compounds, were elevated 6-fold in F-AFE compared with AFE, whereas the levels of arctiin, an arctigenin glycoside, were decreased in F-AFE by approximately 57.40%. These results suggest that arctigenin plays an important role in the anti-allergic effects of F-AFE. Taken together, F-AFE containing anti-allergic phytochemicals, including arctigenin, inhibited the activation of the FcεRI receptor induced by the antigen‑IgE complex. Such effects may provide further information for the development of a phytomedicine for allergic diseases.

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.

Variability of foF2 in the African equatorial ionosphere

NASA Astrophysics Data System (ADS)

Akala, A. O.; Oyeyemi, E. O.; Somoye, E. O.; Adeloye, A. B.; Adewale, A. O.

2010-06-01

This paper presents the impact of diurnal, seasonal and solar activity effects on the variability of ionospheric foF2 in the African equatorial latitude. Three African ionospheric stations; Dakar (14.8°N, 17.4°W, dip: 11.4°N), Ouagadougou (12.4°N, 1.5°W, dip: 2.8°N) and Djibouti (11.5°N, 42.8°E, dip: 7.2°N) were considered for the investigation. The overall aim is to provide African inputs that will be of assistance at improving existing forecasting models. The diurnal analysis revealed that the ionospheric critical frequency (foF2) is more susceptible to variability during the night-time than the day-time, with two peaks in the range; 18-38% during post-sunset hours and 35-55% during post-midnight hours. The seasonal and solar activity analyses showed a post-sunset September Equinox maximum and June Solstice maximum of foF2 variability in all the stations for all seasons. At all the stations, foF2 variability was high for low solar activity year. Overall, we concluded that equatorial foF2 variability increases with decreasing solar activity during night-time.

Posttranscriptional deregulation of signaling pathways in meningioma subtypes by differential expression of miRNAs.

PubMed

Ludwig, Nicole; Kim, Yoo-Jin; Mueller, Sabine C; Backes, Christina; Werner, Tamara V; Galata, Valentina; Sartorius, Elke; Bohle, Rainer M; Keller, Andreas; Meese, Eckart

2015-09-01

Micro (mi)RNAs are key regulators of gene expression and offer themselves as biomarkers for cancer development and progression. Meningioma is one of the most frequent primary intracranial tumors. As of yet, there are limited data on the role of miRNAs in meningioma of different histological subtypes and the affected signaling pathways. In this study, we compared expression of 1205 miRNAs in different meningioma grades and histological subtypes using microarrays and independently validated deregulation of selected miRNAs with quantitative real-time PCR. Clinical utility of a subset of miRNAs as biomarkers for World Health Organization (WHO) grade II meningioma based on quantitative real-time data was tested. Potential targets of deregulated miRNAs were discovered with an in silico analysis. We identified 13 miRNAs deregulated between different subtypes of benign meningiomas, and 52 miRNAs deregulated in anaplastic meningioma compared with benign meningiomas. Known and putative target genes of deregulated miRNAs include genes involved in epithelial-to-mesenchymal transition for benign meningiomas, and Wnt, transforming growth factor-β, and vascular endothelial growth factor signaling for higher-grade meningiomas. Furthermore, a 4-miRNA signature (miR-222, -34a*, -136, and -497) shows promise as a biomarker differentiating WHO grade II from grade I meningiomas with an area under the curve of 0.75. Our data provide novel insights into the contribution of miRNAs to the phenotypic spectrum in benign meningiomas. By deregulating translation of genes belonging to signaling pathways known to be important for meningioma genesis and progression, miRNAs provide a second in line amplification of growth promoting cellular signals. MiRNAs as biomarkers for diagnosis of aggressive meningiomas might prove useful and should be explored further in a prospective manner. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Integrated expression analysis identifies transcription networks in mouse and human gastric neoplasia.

PubMed

Chen, Zheng; Soutto, Mohammed; Rahman, Bushra; Fazili, Muhammad W; Peng, DunFa; Blanca Piazuelo, Maria; Chen, Heidi; Kay Washington, M; Shyr, Yu; El-Rifai, Wael

2017-07-01

Gastric cancer (GC) is a leading cause of cancer-related deaths worldwide. The Tff1 knockout (KO) mouse model develops gastric lesions that include low-grade dysplasia (LGD), high-grade dysplasia (HGD), and adenocarcinomas. In this study, we used Affymetrix microarrays gene expression platforms for analysis of molecular signatures in the mouse stomach [Tff1-KO (LGD) and Tff1 wild-type (normal)] and human gastric cancer tissues and their adjacent normal tissue samples. Combined integrated bioinformatics analysis of mouse and human datasets indicated that 172 genes were consistently deregulated in both human gastric cancer samples and Tff1-KO LGD lesions (P < .05). Using Ingenuity pathway analysis, these genes mapped to important transcription networks that include MYC, STAT3, β-catenin, RELA, NFATC2, HIF1A, and ETS1 in both human and mouse. Further analysis demonstrated activation of FOXM1 and inhibition of TP53 transcription networks in human gastric cancers but not in Tff1-KO LGD lesions. Using real-time RT-PCR, we validated the deregulated expression of several genes (VCAM1, BGN, CLDN2, COL1A1, COL1A2, COL3A1, EpCAM, IFITM1, MMP9, MMP12, MMP14, PDGFRB, PLAU, and TIMP1) that map to altered transcription networks in both mouse and human gastric neoplasia. Our study demonstrates significant similarities in deregulated transcription networks in human gastric cancer and gastric tumorigenesis in the Tff1-KO mouse model. The data also suggest that activation of MYC, STAT3, RELA, and β-catenin transcription networks could be an early molecular step in gastric carcinogenesis. © 2017 Wiley Periodicals, Inc.

Transgenerational epigenetic effects of the endocrine disruptor vinclozolin on pregnancies and female adult onset disease.

PubMed

Nilsson, Eric E; Anway, Matthew D; Stanfield, Jacob; Skinner, Michael K

2008-05-01

Endocrine disruptor exposure during gonadal sex determination was previously found to induce male rat adult onset transgenerational disease (F1-F4 generation), and this was associated with an alteration in the epigenetic (i.e., DNA methylation) programming of the male germ line. The current study was designed to characterize the transgenerational disease phenotypes of the female adult offspring. Pregnant rats (F0 generation) were treated transiently with vinclozolin (i.e., fungicide with anti-androgenic activity) on embryonic (E) days E8-E14 of gestation. F1 control and vinclozolin generation offspring from different litters were mated to produce F2 offspring, and similarly F2 generation animals produced F3 generation offspring. Observations demonstrated that 9 out of 105 pregnant rats (8.6%) from the vinclozolin F1-F3 generations exhibited uterine hemorrhage and/or anemia late in pregnancy. None (0 out of 82) of the control F1-F3 generation females had similar pregnancy problems. Complete blood cell counts and serum chemistry profiles demonstrated that selected vinclozolin generation animals, but not controls, exhibited marked regenerative anemia in late pregnancy. Examination of kidney histology revealed moderate or severe glomerular abnormalities in 67% of the vinclozolin F2 and F3 generation adult females compared with 18% of the controls. Adult female vinclozolin generation animals also developed various types of tumors in 6.5% of the animals (11 out of 170), while 2% of control-line animals (3 out of 151) developed mammary tumors. Observations demonstrate that vinclozolin exposure during gonadal sex determination promotes a transgenerational increase in pregnancy abnormalities and female adult onset disease states.

Transgenerational epigenetic effects of the endocrine disruptor vinclozolin on pregnancies and female adult onset disease

PubMed Central

Nilsson, Eric E; Anway, Matthew D; Stanfield, Jacob; Skinner, Michael K

2017-01-01

Endocrine disruptor exposure during gonadal sex determination was previously found to induce male rat adult onset transgenerational disease (F1–F4 generation), and this was associated with an alteration in the epigenetic (i.e., DNA methylation) programming of the male germ line. The current study was designed to characterize the transgenerational disease phenotypes of the female adult offspring. Pregnant rats (F0 generation) were treated transiently with vinclozolin (i.e., fungicide with anti-androgenic activity) on embryonic (E) days E8–E14 of gestation. F1 control and vinclozolin generation offspring from different litters were mated to produce F2 offspring, and similarly F2 generation animals produced F3 generation offspring. Observations demonstrated that 9 out of 105 pregnant rats (8.6%) from the vinclozolin F1–F3 generations exhibited uterine hemorrhage and/or anemia late in pregnancy. None (0 out of 82) of the control F1–F3 generation females had similar pregnancy problems. Complete blood cell counts and serum chemistry profiles demonstrated that selected vinclozolin generation animals, but not controls, exhibited marked regenerative anemia in late pregnancy. Examination of kidney histology revealed moderate or severe glomerular abnormalities in 67% of the vinclozolin F2 and F3 generation adult females compared with 18% of the controls. Adult female vinclozolin generation animals also developed various types of tumors in 6.5% of the animals (11 out of 170), while 2% of control-line animals (3 out of 151) developed mammary tumors. Observations demonstrate that vinclozolin exposure during gonadal sex determination promotes a transgenerational increase in pregnancy abnormalities and female adult onset disease states. PMID:18304984

Competing E2 and SN2 Mechanisms for the F- + CH3CH2I Reaction.

PubMed

Yang, Li; Zhang, Jiaxu; Xie, Jing; Ma, Xinyou; Zhang, Linyao; Zhao, Chenyang; Hase, William L

2017-02-09

Anti-E2, syn-E2, inv-, and ret-S N 2 reaction channels for the gas-phase reaction of F - + CH 3 CH 2 I were characterized with a variety of electronic structure calculations. Geometrical analysis confirmed synchronous E2-type transition states for the elimination of the current reaction, instead of nonconcerted processes through E1cb-like and E1-like mechanisms. Importantly, the controversy concerning the reactant complex for anti-E2 and inv-S N 2 paths has been clarified in the present work. A positive barrier of +19.2 kcal/mol for ret-S N 2 shows the least feasibility to occur at room temperature. Negative activation energies (-16.9, -16.0, and -4.9 kcal/mol, respectively) for inv-S N 2, anti-E2, and syn-E2 indicate that inv-S N 2 and anti-E2 mechanisms significantly prevail over the eclipsed elimination. Varying the leaving group for a series of reactions F - + CH 3 CH 2 Y (Y = F, Cl, Br, and I) leads to monotonically decreasing barriers, which relates to the gradually looser TS structures following the order F > Cl > Br > I. The reactivity of each channel nearly holds unchanged except for the perturbation between anti-E2 and inv-S N 2. RRKM calculation reveals that the reaction of the fluorine ion with ethyl iodide occurs predominately via anti-E2 elimination, and the inv-S N 2 pathway is suppressed, although it is energetically favored. This phenomenon indicates that, in evaluating the competition between E2 and S N 2 processes, the kinetic or dynamical factors may play a significant role. By comparison with benchmark CCSD(T) energies, MP2, CAM-B3LYP, and M06 methods are recommended to perform dynamics simulations of the title reaction.

Associations between active trachoma and community intervention with Antibiotics, Facial cleanliness, and Environmental improvement (A,F,E).

PubMed

Ngondi, Jeremiah; Matthews, Fiona; Reacher, Mark; Baba, Samson; Brayne, Carol; Emerson, Paul

2008-04-30

Surgery, Antibiotics, Facial cleanliness and Environmental improvement (SAFE) are advocated by the World Health Organization (WHO) for trachoma control. However, few studies have evaluated the complete SAFE strategy, and of these, none have investigated the associations of Antibiotics, Facial cleanliness, and Environmental improvement (A,F,E) interventions and active trachoma. We aimed to investigate associations between active trachoma and A,F,E interventions in communities in Southern Sudan. Surveys were undertaken in four districts after 3 years of implementation of the SAFE strategy. Children aged 1-9 years were examined for trachoma and uptake of SAFE assessed through interviews and observations. Using ordinal logistic regression, associations between signs of active trachoma and A,F,E interventions were explored. Trachomatous inflammation-intense (TI) was considered more severe than trachomatous inflammation-follicular (TF). A total of 1,712 children from 25 clusters (villages) were included in the analysis. Overall uptake of A,F,E interventions was: 53.0% of the eligible children had received at least one treatment with azithromycin; 62.4% children had a clean face on examination; 72.5% households reported washing faces of children two or more times a day; 73.1% households had received health education; 44.4% of households had water accessible within 30 minutes; and 6.3% households had pit latrines. Adjusting for age, sex, and district baseline prevalence of active trachoma, factors independently associated with reduced odds of a more severe active trachoma sign were: receiving three treatments with azithromycin (odds ratio [OR] = 0.1; 95% confidence interval [CI] 0.0-0.4); clean face (OR = 0.3; 95% CI 0.2-0.4); washing faces of children three or more times daily (OR = 0.4; 95% CI 0.3-0.7); and presence and use of a pit latrine in the household (OR = 0.4; 95% CI 0.2-0.9). Analysis of associations between the A,F,E components of the SAFE strategy and active trachoma showed independent protective effects against active trachoma of mass systemic azithromycin treatment, facial cleanliness, face washing, and use of pit latrines in the household. This strongly argues for continued use of all the components of the SAFE strategy together.

Massive deregulation of miRNAs from nuclear reprogramming errors during trophoblast differentiation for placentogenesis in cloned pregnancy.

PubMed

Hossain, Md Munir; Tesfaye, Dawit; Salilew-Wondim, Dessie; Held, Eva; Pröll, Maren J; Rings, Franca; Kirfel, Gregor; Looft, Christian; Tholen, Ernst; Uddin, Jasim; Schellander, Karl; Hoelker, Michael

2014-01-18

Low efficiency of Somatic Cell Nuclear Transfer (NT) has been widely addressed with high incidence of placental abnormalities due to genetic and epigenetic modifications. MiRNAs are shown to be major regulators of such modifications. The present study has been carried out to identify the expression patterns of 377 miRNAs, their functional associations and mechanism of regulation in bovine placentas derived from artificial insemination (AI), in vitro production (IVP) and NT pregnancies. This study reveals a massive deregulation of miRNAs as chromosomal cluster or miRNA families without sex-linkage in NT and in-vitro derived IVP placentas. Cell specific localization miRNAs in blastocysts and expression profiling of embryos and placentas at different developmental stages identified that the major deregulation of miRNAs exhibited in placentas at day 50 of pregnancies is found to be less dependent on global DNA methylation, rather than on aberrant miRNA biogenesis molecules. Among them, aberrant AGO2 expression due to hypermethylation of its promoter was evident. Along with other factors, aberrant AGO2 expression was observed to be associated with multiple defects in trophoblast differentiation through deregulation of miRNAs mediated mechanisms. These aberrant miRNA activities might be associated with genetic and epigenetic modifications in abnormal placentogenesis due to maldifferentiation of early trophoblast cell lineage in NT and IVP pregnancies. This study provides the first insight into genome wide miRNA expression, their role in regulation of trophoblast differentiation as well as abnormal placental development in Somatic Cell Nuclear Transfer pregnancies to pave the way to improve the efficiency of cloning by nuclear transfer.

Massive deregulation of miRNAs from nuclear reprogramming errors during trophoblast differentiation for placentogenesis in cloned pregnancy

PubMed Central

2014-01-01

Background Low efficiency of Somatic Cell Nuclear Transfer (NT) has been widely addressed with high incidence of placental abnormalities due to genetic and epigenetic modifications. MiRNAs are shown to be major regulators of such modifications. The present study has been carried out to identify the expression patterns of 377 miRNAs, their functional associations and mechanism of regulation in bovine placentas derived from artificial insemination (AI), in vitro production (IVP) and NT pregnancies. Results This study reveals a massive deregulation of miRNAs as chromosomal cluster or miRNA families without sex-linkage in NT and in-vitro derived IVP placentas. Cell specific localization miRNAs in blastocysts and expression profiling of embryos and placentas at different developmental stages identified that the major deregulation of miRNAs exhibited in placentas at day 50 of pregnancies is found to be less dependent on global DNA methylation, rather than on aberrant miRNA biogenesis molecules. Among them, aberrant AGO2 expression due to hypermethylation of its promoter was evident. Along with other factors, aberrant AGO2 expression was observed to be associated with multiple defects in trophoblast differentiation through deregulation of miRNAs mediated mechanisms. Conclusion These aberrant miRNA activities might be associated with genetic and epigenetic modifications in abnormal placentogenesis due to maldifferentiation of early trophoblast cell lineage in NT and IVP pregnancies. This study provides the first insight into genome wide miRNA expression, their role in regulation of trophoblast differentiation as well as abnormal placental development in Somatic Cell Nuclear Transfer pregnancies to pave the way to improve the efficiency of cloning by nuclear transfer. PMID:24438674

Ionospheric Peak Electron Density and Performance Evaluation of IRI-CCIR Near Magnetic Equator in Africa During Two Extreme Solar Activities

NASA Astrophysics Data System (ADS)

Adebesin, B. O.; Rabiu, A. B.; Obrou, O. K.; Adeniyi, J. O.

2018-03-01

The F2 layer peak electron density (NmF2) was investigated over Korhogo (Geomagnetic: 1.26°S, 67.38°E), a station near the magnetic equator in the African sector. Data for 1996 and 2000 were, respectively, categorized into low solar quiet and disturbed and high solar quiet and disturbed. NmF2 prenoon peak was higher than the postnoon peak during high solar activity irrespective of magnetic activity condition, while the postnoon peak was higher for low solar activity. Higher NmF2 peak amplitude characterizes disturbed magnetic activity than quiet magnetic condition for any solar activity. The maximum peaks appeared in equinox. June solstice noontime bite out lagged other seasons by 1-2 h. For any condition of solar and magnetic activities, the daytime NmF2 percentage variability (%VR) measured by the relative standard deviation maximizes/minimizes in June solstice/equinox. Daytime variability increases with increasing magnetic activity. The highest peak in the morning time NmF2 variability occurs in equinox, while the highest evening/nighttime variability appeared in June solstice for all solar/magnetic conditions. The nighttime annual variability amplitude is higher during disturbed than quiet condition regardless of solar activity period. At daytime, variability is similar for all conditions of solar activities. NmF2 at Korhogo is well represented on the International Reference Ionosphere-International Radio Consultative Committee (IRI-CCIR) option. The model/observation relationship performed best between local midnight and postmidnight period (00-08 LT). The noontime trough characteristics is not prominent in the IRI pattern during high solar activity but evident during low solar conditions when compared with Korhogo observations. The Nash-Sutcliffe coefficients revealed better model performance during disturbed activities.

Effects of fluorine incorporation into β-Ga2O3

NASA Astrophysics Data System (ADS)

Yang, Jiangcheng; Fares, Chaker; Ren, F.; Sharma, Ribhu; Patrick, Erin; Law, Mark E.; Pearton, S. J.; Kuramata, Akito

2018-04-01

β-Ga2O3 rectifiers fabricated on lightly doped epitaxial layers on bulk substrates were exposed to CF4 plasmas. This produced a significant decrease in Schottky barrier height relative to unexposed control diodes (0.68 eV compared to 1.22 eV) and degradation in ideality factor (2.95 versus 1.01 for the control diodes). High levels of F (>1022 cm-3) were detected in the near-surface region by Secondary Ion Mass Spectrometry. The diffusion of fluorine into the Ga2O3 was thermally activated with an activation energy of 1.24 eV. Subsequent annealing in the range 350-400 °C brought recovery of the diode characteristics and an increase in barrier height to a value larger than in the unexposed control diodes (1.36 eV). Approximately 70% of the initial F was removed from the Ga2O3 by 400 °C, with the surface outgas rate also being thermally activated with an activation energy of 1.23 eV. Very good fits to the experimental data were obtained by integrating physics of the outdiffusion mechanisms into the Florida Object Oriented Process Simulator code and assuming that the outgas rate from the surface was mediated through fluorine molecule formation. The fluorine molecule forward reaction rate had an activation energy of 1.24 eV, while the reversal rate of this reaction had an activation energy of 0.34 eV. The net carrier density in the drift region of the rectifiers decreased after CF4 exposure and annealing at 400 °C. The data are consistent with a model in which near-surface plasma-induced damage creates degraded Schottky barrier characteristics, but as the samples are annealed, this damage is removed, leaving the compensation effect of Si donors by F- ions. The barrier lowering and then enhancement are due to the interplay between surface defects and the chemical effects of the fluorine.

Environmental Baseline Survey Parcel E2, F, and I, Military Housing Areas Nellis Air Force Base, Nevada. Phase 1

DTIC Science & Technology

2011-09-01

SEP 2011 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Final Phase I Environmental Baseline Survey Parcel E2, F, and I...lead-based paint LUST leaking underground storage tank M.D.M. Mount Diablo Meridian MFH military family housing MHPI Military Housing...northwest OWS oil/water separator PADS PCB Activity Database PCB polychorinated biphenyl PCR Physical Condition Report PDF portable

Phase 1 Environmental Baseline Survey Parcels E2, F, and I, Military Housing Areas, Nellis Air Force Base, Nevada

DTIC Science & Technology

2011-09-01

21 SEP 2011 2. REPORT TYPE N/A 3. DATES COVERED 4. TITLE AND SUBTITLE Final Phase I Environmental Baseline Survey Parcels E2, F, and I...leaking underground storage tank M.D.M. Mount Diablo Meridian MFH military family housing MHPI Military Housing Privatization Initiative MSL...water separator PADS PCB Activity Database PCB polychorinated biphenyl PCR Physical Condition Report PDF portable document format PPV

Genomic structure, expression pattern, and functional characterization of transcription factor E2F-2 from black tiger shrimp (Penaeus monodon)

PubMed Central

Zhao, Chao; Qiu, Lihua

2017-01-01

Transcription factor E2F-2 is a regulator of cell cycle. Researchers identified E2F-2 genes from yeasts to humans, but few reports investigated E2F-2 gene from black tiger shrimp. In the present study, we cloned E2F-2 gene from black tiger shrimp (Penaeus monodon). Full-length PmE2F-2 complementary DNA sequence measures 3,189 bp with an open reading frame of 1,371 bp. Complete PmE2F-2 genomic sequence (17,305 bp) of P. monodon contains nine exons, which are separated by eight introns. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis indicated that PmE2F-2 is highly expressed in hepatopancreas and ovaries of P. monodon. Highest PmE2F-2 expression levels were observed in stage III ovarian development of P. monodon. PmE2F-2 expression levels were significantly augmented in ovaries of P. monodon after 5-hydroxytryptamine injection and eyestalk ablation. RNA interference experiments were conducted to examine PmE2F-2, PmCDK2, and PmCyclin E expression profiles. PmE2F-2 was successfully knocked down in ovaries and hepatopancreas via double-stranded RNA (dsRNA)–E2F-2 injection. In the same organs, PmE2F-2 expression localization and level were investigated through in situ hybridization, which revealed consistent results with those of qRT-PCR. After dsRNA—E2F-2 injection, gonadosomatic index of shrimp was significantly lower than those following dsRNA—GFP and phosphate-buffered solution injections. Therefore, PmE2F-2 may be involved in ovarian maturation in P. monodon. PMID:28558060

Radiation Dose Deposition in the Active Marrow of Reference Man.

DTIC Science & Technology

1977-10-31

204 16 1.546E-10 .252 1,427E-10 .261 1,292E1o .273 17 1.530F-10 .237 10580E.10 9304 1.ooIEinl o272 18 9.490E11l .308 19494E-10 9249 1.3ASE-10 .268 19...IO ,269 2,399E-10 .198 29337E-10 .19217 8,124F-11 .288 1,310E-10 .?28 19331E-10 .244 18 9.013E-11 .292 2.403E-o0 . 204 2.002E-1O .199 q 7.s69E-i1 .Sl1...2.88SE-t0 viol 3,37bf-10 .155 16 1.379E-10 .227 ?.586E-i0 .179 2.030E-t0 . 204 17 2.23SEin10 .226 1.8O1E-10 .237 2,044E-10 .195 18 1.429E-I0 .?268 2367E-10

Synthetic regulators of the 2-oxoglutarate oxidative decarboxylation alleviate the glutamate excitotoxicity in cerebellar granule neurons.

PubMed

Kabysheva, Maria S; Storozhevykh, Tatiana P; Pinelis, Vsevolod G; Bunik, Victoria I

2009-05-01

Impairment of the 2-oxoglutarate oxidative decarboxylation by the 2-oxoglutarate dehydrogenase complex (OGDHC) is associated with the glutamate accumulation, ROS production and neuropathologies. We hypothesized that correct function of OGDHC under metabolic stress is essential to overcome the glutamate excitotoxic action on neurons. We show that synthetic phosphono analogs of 2-oxoglutarate, succinyl phosphonate and its phosphono ethyl ester, improve the catalysis by brain OGDHC through inhibiting the side reaction of irreversible inactivation of its first component, 2-oxoglutarate dehydrogenase. Under the substrate and cofactor saturation, the component and complex undergo the inactivation during catalysis with the apparent rate constant 0.2 min(-1). The inactivation rate is reduced by 90% and 60% in the presence of 50 microM succinyl phosphonate and its phosphono ethyl ester, correspondingly. In cultured cerebellar granule neurons exposed to excitotoxic glutamate, the phosphonates (100 microM) protect from the irreversible impairment of mitochondrial function and delayed calcium deregulation. The deregulation amplitude is decreased by succinyl phosphonate and its phosphono ethyl ester by 50% and 30%, correspondingly. Thus, succinyl phosphonate is more potent than its phosphono ethyl ester in protecting both the isolated brain OGDHC from inactivation and cultured neurons from the glutamate-induced calcium deregulation. The correlation of the relative efficiency of the phosphonates in vitro and in situ indicates that their cellular effects are due to targeting OGDHC, which is in accord with independent studies. We conclude that the compounds preserving the 2-oxoglutarate dehydrogenase activity are of neuroprotective value upon metabolic disbalance induced by glutamate excess.

PDLIM2 suppresses human T-cell leukemia virus type I Tax-mediated tumorigenesis by targeting Tax into the nuclear matrix for proteasomal degradation

PubMed Central

Yan, Pengrong; Fu, Jing; Qu, Zhaoxia; Li, Shirong; Tanaka, Takashi; Grusby, Michael J.

2009-01-01

The mechanisms by which the human T-cell leukemia virus type I (HTLV-I) Tax oncoprotein deregulates cellular signaling for oncogenesis have been extensively studied, but how Tax itself is regulated remains largely unknown. Here we report that Tax was negatively regulated by PDLIM2, which promoted Tax K48-linked polyubiquitination. In addition, PDLIM2 recruited Tax from its functional sites into the nuclear matrix where the polyubiquitinated Tax was degraded by the proteasome. Consistently, PDLIM2 suppressed Tax-mediated signaling activation, cell transformation, and oncogenesis both in vitro and in animal. Notably, PDLIM2 expression was down-regulated in HTLV-I–transformed T cells, and PDLIM2 reconstitution reversed the tumorigenicity of the malignant cells. These studies indicate that the counterbalance between HTLV-I/Tax and PDLIM2 may determine the outcome of HTLV-I infection. These studies also suggest a potential therapeutic strategy for cancers and other diseases associated with HTLV-I infection and/or PDLIM2 deregulation. PMID:19131544

Emerging role of Hippo pathway in gastric and other gastrointestinal cancers.

PubMed

Kang, Wei; Cheng, Alfred S L; Yu, Jun; To, Ka Fai

2016-01-21

More evidence has underscored the importance of Hippo signaling pathway in gastrointestinal tissue homeostasis, whereas its deregulation induces tumorigenesis. Yes-associated protein 1 (YAP1) and its close paralog TAZ, transcriptional co-activator with a PDZ-binding motif, function as key effectors negatively controlled by the Hippo pathway. YAP1/TAZ exerts oncogenic activities by transcriptional regulation via physical interaction with TEAD transcription factors. In various cancers, Hippo pathway cross-talks with pro- or anti-tumorigenic pathways such as GPCR, Wnt/β-catenin, Notch and TGF-β signaling and is deregulated by multiple factors including cell density/junction and microRNAs. As YAP1 expression is significantly associated with poor prognosis of gastric and other gastrointestinal cancers, detailed delineation of Hippo regulation in tumorigenesis provides novel insight for therapeutic intervention. In current review, we summarized the recent research progresses on the deregulation of Hippo pathway in the gastrointestinal tract including stomach and discuss the molecular consequences leading to tumorigenesis.

Novel Podophyllotoxin Derivatives as Partial PPARγ Agonists and their Effects on Insulin Resistance and Type 2 Diabetes.

PubMed

Zhang, Xiangming; Liu, Huijuan; Sun, Bo; Sun, Yan; Zhong, Weilong; Liu, Yanrong; Chen, Shuang; Ling, Honglei; Zhou, Lei; Jing, Xiangyan; Qin, Yuan; Xiao, Ting; Sun, Tao; Zhou, Honggang; Yang, Cheng

2016-11-17

Peroxisome proliferator-activated receptor γ (PPARγ) is recognized as a key regulator of insulin resistance. In this study, we searched for novel PPARγ agonists in a library of structurally diverse organic compounds and determined that podophyllotoxin exhibits partial agonist activity toward PPARγ. Eight novel podophyllotoxin-like derivatives were synthesized and assayed for toxicity and functional activity toward PPARγ to reduce the possible systemic toxic effects of podophyllotoxin and to maintain partial agonist activity toward PPARγ. Cell-based transactivation assays showed that compounds (E)-3-(hydroxy(3,4,5-trimethoxyphenyl)methyl)-4-(4(trifluoromethyl)styryl)dihydrofuran-2(3H)-one (3a) and (E)-4-(3-acetylstyryl)-3-(hydroxyl (3,4,5-trimethoxyphenyl)methyl)dihydrofuran-2(3H)-one (3f) exhibited partial agonist activity. An experiment using human hepatocarcinoma cells (HepG2) that were induced to become an insulin-resistant model showed that compounds 3a and 3f improved insulin sensitivity and glucose consumption. In addition, compounds 3a and 3f significantly improved hyperglycemia and insulin resistance in high-fat diet-fed streptozotocin (HFD-STZ)-induced type 2 diabetic rats at a dose of 15 mg/kg/day administered orally for 45 days, without significant weight gain. Cell toxicity testing also showed that compounds 3a and 3f exhibited weaker toxicity than pioglitazone. These findings suggested that compounds 3a and 3f improved insulin resistance in vivo and in vitro and that the compounds exhibited potential for the treatment of type 2 diabetes mellitus.

The disruption of a novel limb cis-regulatory element of SHH is associated with autosomal dominant preaxial polydactyly-hypertrichosis

PubMed Central

Petit, Florence; Jourdain, Anne-Sophie; Holder-Espinasse, Muriel; Keren, Boris; Andrieux, Joris; Duterque-Coquillaud, Martine; Porchet, Nicole; Manouvrier-Hanu, Sylvie; Escande, Fabienne

2016-01-01

The expression gradient of the morphogen Sonic Hedgehog (SHH) is crucial in establishing the number and the identity of the digits during anteroposterior patterning of the limb. Its anterior ectopic expression is responsible for preaxial polydactyly (PPD). Most of these malformations are due to the gain-of-function of the Zone of Polarizing Activity Regulatory Sequence, the only limb-specific enhancer of SHH known to date. We report a family affected with a novel condition associating PPD and hypertrichosis of the upper back, following an autosomal dominant mode of inheritance. This phenotype is consistent with deregulation of SHH expression during limb and follicle development. In affected members, we identified a 2 kb deletion located ~240 kb upstream from the SHH promoter. The deleted sequence is capable of repressing the transcriptional activity of the SHH promoter in vitro, consistent with a silencer activity. We hypothesize that the deletion of this silencer could be responsible for SHH deregulation during development, leading to a PPD-hypertrichosis phenotype. PMID:25782671

Monitoring Pc 4-mediated photodynamic therapy of U87 tumors with 18F- fluorodeoxy-glucose PET imaging in the Athymic Nude Rat

NASA Astrophysics Data System (ADS)

Varghai, Davood; Cross, Nathan; Spring-Robinson, Chandra; Sharma, Rahul; Feyes, Denise K.; Ahmad, Yusra; Oleinick, Nancy L.; Muzic, Raymond F., Jr.; Dean, David

2007-02-01

Introduction: We have previously demonstrated the use of phthalocyanine Pc 4 for the photodynamic therapy (PDT) of ectopic human glial tumors in the athymic nude rat brain. We wish to determine whether 18F-fluorodeoxy-glucose ( 18F-FDG) Positron Emission Tomography (PET) imaging can detect the reduction in tumor metabolism that must occur after Pc 4-PDT-induced necrosis. Methods: 2.5 x 10 5 U87 cells were injected into the brains of 12 athymic nude rats. After 7 days of tumor growth, all 12 animals were imaged functionally by 18F-FDG micro-PET (μPET) and structurally by micro-CT and/or micro-MR. These animals received 0.5 mg/kg b.w. Pc 4 via tail-vein injection. One day later the scalp was re-incised and the tumor illuminated with 30 J/cm2 of 672-nm light from a diode laser. The next day these animals were again 18F-FDG μPET imaged. Next, the animals were euthanized and their brains were explanted for H&E histology. Results: Histology showed that tumors in the 6 Pc 4-PDT-treated animals demonstrated necrosis ranging from full to frank (severe). Preliminary analysis showed that 18F-FDG μPET activity in 3 of the 6 non-PDT group (i.e., no tumor necrosis observed) animals was seen to increase 2.28 times following tumor photoirradiation, whereas 18F-FDG μPET activity in 5 of the 6 PDT group (i.e., tumor necrosis observed) animals was seen to increase 1.15 times following tumor photoirradiation. Discussion: The increased 18F-FDG μPET activity in the PDT group was unexpected. We had expected this activity to decrease and are presently investigating the cause of this observation.

Allergenicity, trypsin inhibitor activity and nutritive quality of enzymatically modified soy proteins.

PubMed

De La Barca, Ana María Calderón; Wall, Abraham; López-Díaz, José Alberto

2005-05-01

Two ultrafiltered soy flour protein fractions were evaluated; the first was obtained by hydrolysis (0.5-3 kDa, F(0.5-3)), and the second was an enzymatically methionine-enriched fraction (1-10 kDa, F(1-10)E). Amino acid profiles, protein quality, allergenicity (against soy-sensitive infant sera) and trypsin inhibitor activity were determined. Fraction F(1-10)E fulfilled amino acid requirements for infants, whereas the F(0.5-3) fraction was methionine deficient. Both fractions were similar in net protein utilization, and F(1-10)E digestibility was comparable with casein and higher (P?

PAK1 translocates into nucleus in response to prolactin but not to estrogen

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

Oladimeji, Peter, E-mail: Peter.Oladimeji@rockets.utoledo.edu; Diakonova, Maria, E-mail: mdiakon@utnet.utoledo.edu

2016-04-22

Tyrosyl phosphorylation of the p21-activated serine–threonine kinase 1 (PAK1) has an essential role in regulating PAK1 functions in breast cancer cells. We previously demonstrated that PAK1 serves as a common node for estrogen (E2)- and prolactin (PRL)-dependent pathways. We hypothesize herein that intracellular localization of PAK1 is affected by PRL and E2 treatments differently. We demonstrate by immunocytochemical analysis that PAK1 nuclear translocation is ligand-dependent: only PRL but not E2 stimulated PAK1 nuclear translocation. Tyrosyl phosphorylation of PAK1 is essential for this nuclear translocation because phospho-tyrosyl-deficient PAK1 Y3F mutant is retained in the cytoplasm in response to PRL. We confirmedmore » these data by Western blot analysis of subcellular fractions. In 30 min of PRL treatment, only 48% of pTyr-PAK1 is retained in the cytoplasm of PAK1 WT clone while 52% re-distributes into the nucleus and pTyr-PAK1 shuttles back to the cytoplasm by 60 min of PRL treatment. In contrast, PAK1 Y3F is retained in the cytoplasm. E2 treatment causes nuclear translocation of neither PAK1 WT nor PAK1 Y3F. Finally, we show by an in vitro kinase assay that PRL but not E2 stimulates PAK1 kinase activity in the nuclear fraction. Thus, PAK1 nuclear translocation is ligand-dependent: PRL activates PAK1 and induces translocation of activated pTyr-PAK1 into nucleus while E2 activates pTyr-PAK1 only in the cytoplasm. - Highlights: • Prolactin but not estrogen causes translocation of PAK1 into nucleus. • Tyrosyl phosphorylation of PAK1 is required for nuclear localization. • Prolactin but not estrogen stimulates PAK1 kinase activity in nucleus.« less

Thermoluminescence dosimetric characteristics on cubic fluoroperovskite single crystal (KMgF3:Eu2+, Ce3+)

NASA Astrophysics Data System (ADS)

Joseph Daniel, D.; Madhusoodanan, U.; Annalakshmi, O.; Jose, M. T.; Ramasamy, P.

2015-07-01

This paper describes investigation of thermoluminescence radiation dosimetry characteristics of Eu2+ doped Potassium Magnesium Fluoride (KMgF3) single crystal co-doped with Ce3+ ions. The perovskite-like KMgF3 polycrystalline compounds were synthesized by standard solid state reaction technique. Phase purity of the synthesized compounds was analyzed by powder X-ray diffraction technique. Single crystals of KMgF3 have been grown from melt by using a vertical Bridgman-Stockbarger method. Thermoluminescence (TL) characteristics of KMgF3 samples doped with Eu2+ and Ce3+ have been studied after β-ray irradiation at room temperature. Order of kinetics (b), activation energy (E), and frequency factor (s) were determined by Chen's method and variable heating rate method. Results show that the TL glow peak of the KMgF3 samples obeys second-order kinetics. Analysis of the main dosimetric peak by using the methods mentioned above revealed that activation energy (E) is about 1.2 eV and the frequency factor (s) is in the range 1010-1011 s-1. The TL glow curve structure of the sample remained stable for higher doses of 90Sr/90Y beta source and it shows linearity up to 180 Gy. The time dependent fading behavior of the TL characteristics has also been investigated and is found to be quite stable over long time duration. The characteristic Eu2+ emissions are observed in the TL emission spectra.

E2F1 and NF-κB: Key Mediators of Inflammation-associated Cancers and Potential Therapeutic Targets.

PubMed

Huang, Yulin; Chen, Rui; Zhou, Jianwei

2016-01-01

Inflammation is the fundamental protective response; however disordered immuno-response can cause chronic human disease, including cancer. Inflammatory cells and mediators are essential to the tumor microenvironment and dissection of this complex molecular and cellular milieu may elucidate a connection between cancer and inflammation and help to identify potential novel therapeutic targets. Thus, focusing on transcription factor NF-κB and E2F1 in inflammation-associated cancer is urgent. NF-κB activation is prevalent in carcinomas, mainly driven by inflammatory cytokines in the tumor microenvironment. E2F1 is also involved in regulating immune responses. Understanding the crosstalk between the two pathways may contribute to the development of novel anti-cancer drugs.

New cholinesterase inhibitors for Alzheimer's disease: Structure Activity Studies (SARs) and molecular docking of isoquinolone and azepanone derivatives.

PubMed

Bacalhau, Patrícia; San Juan, Amor A; Marques, Carolina S; Peixoto, Daniela; Goth, Albertino; Guarda, Cátia; Silva, Mara; Arantes, Sílvia; Caldeira, A Teresa; Martins, Rosário; Burke, Anthony J

2016-08-01

A library of isoquinolinone and azepanone derivatives were screened for both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activity. The strategy adopted included (a) in vitro biological assays, against eel AChE (EeAChE) and equine serum BuChE (EqBuChE) in order to determine the compounds IC50 and their dose-response activity, consolidated by (b) molecular docking studies to evaluate the docking poses and interatomic interactions in the case of the hit compounds, validated by STD-NMR studies. Compound (1f) was identified as one of these hits with an IC50 of 89.5μM for EeAChE and 153.8μM for EqBuChE, (2a) was identified as a second hit with an IC50 of 108.4μM (EeAChE) and 277.8μM (EqBuChE). In order to gain insights into the binding mode and principle active site interactions of these molecules, (R)-(1f) along with 3 other analogues (also as the R-enantiomer) were docked into both RhAChE and hBuChE models. Galantamine was used as the benchmark. The docking study was validated by performing an STD-NMR study of (1f) with EeAChE using galantamine as the benchmark. Copyright © 2016 Elsevier Inc. All rights reserved.

SUMOylation of DRIL1 Directs Its Transcriptional Activity Towards Leukocyte Lineage-Specific Genes

PubMed Central

van Lohuizen, Maarten; Peeper, Daniel S.

2009-01-01

DRIL1 is an ARID family transcription factor that can immortalize primary mouse fibroblasts, bypass RASV12-induced cellular senescence and collaborate with RASV12 or MYC in mediating oncogenic transformation. It also activates immunoglobulin heavy chain transcription and engages in heterodimer formation with E2F to stimulate E2F-dependent transcription. Little, however, is known about the regulation of DRIL1 activity. Recently, DRIL1 was found to interact with the SUMO-conjugating enzyme Ubc9, but the functional relevance of this association has not been assessed. Here, we show that DRIL1 is sumoylated both in vitro and in vivo at lysine 398. Moreover, we provide evidence that PIASy functions as a specific SUMO E3-ligase for DRIL1 and promotes its sumoylation both in vitro and in vivo. Furthermore, consistent with the subnuclear localization of PIASy in the Matrix-Associated Region (MAR), SUMO-modified DRIL1 species are found exclusively in the MAR fraction. This post-translational modification interferes neither with the subcellular localization nor the DNA-binding activity of the protein. In contrast, DRIL1 sumoylation impairs its interaction with E2F1 in vitro and modifies its transcriptional activity in vivo, driving transcription of subset of genes regulating leukocyte fate. Taken together, these results identify sumoylation as a novel post-translational modification of DRIL1 that represents an important mechanism for targeting and modulating DRIL1 transcriptional activity. PMID:19436740

New species of Cenozoic benthic foraminifera from the former British Petroleum micropalaeontology collection

NASA Astrophysics Data System (ADS)

Fox, Lyndsey R.; Stukins, Stephen; Hill, Tom; Bailey, Haydon

2018-01-01

This paper describes four new Cenozoic, deep-water benthic foraminifera from the reference collections at the Natural History Museum in London. The focus is on selected calcareous taxa that are of stratigraphical and/or palaeoecological significance for academic and industrial-related activities. Alabamina heyae (urn:lsid:zoobank.org:act:1E8A66E9-1F4C-4B61-BA97-6E0ECCD0173E), Nonion cepa (urn:lsid:zoobank.org:act:9F36350A-1E49-4D69-B2CC-C83F343E2952), Uvigerina kingi (urn:lsid:zoobank.org:act:C36C89C2-2E65-4FF6-9368-C169B4591995) and Lenticulina stewarti (urn:lsid:zoobank.org:act:485AE871-CECA-44E8-ABD1-BAE2961FFD59) are described with new illustrations. Their biostratigraphic and palaeoecological significance is briefly discussed.

47 CFR 32.23 - Nonregulated activities.

Code of Federal Regulations, 2010 CFR

2010-10-01

... accounting purposes as regulated activities. Activities that have been deregulated at the interstate level... section describes the accounting treatment of activities classified for accounting purposes as... subject to regulation will be classified for accounting purposes as “nonregulated.” Activities that...

Single crystals of the fluorite nonstoichiometric phase Eu{0.916/2+}Eu{0.084/3+}F2.084 (conductivity, transmission, and hardness)

NASA Astrophysics Data System (ADS)

Sobolev, B. P.; Turkina, T. M.; Sorokin, N. I.; Karimov, D. N.; Komar'kova, O. N.; Sulyanova, E. A.

2010-07-01

The nonstoichiometric phase EuF2+ x has been obtained via the partial reduction of EuF3 by elementary Si at 900-1100°C. Eu{0.916/2+}Eu{0.084/3+}F2.084 (EuF2.084) single crystals have been grown from melt by the Bridgman method in a fluorinating atmosphere. These crystals belong to the CaF2 structure type (sp. gr. Fm bar 3 m) with the cubic lattice parameter a = 5.8287(2) Å, are transparent in the spectral range of 0.5-11.3 μm, and have microhardness H μ = 3.12 ± 0.13 GPa and ionic conductivity σ = 1.4 × 10-5 S/cm at 400°C with the ion transport activation energy E a = 1.10 ± 0.05 eV. The physicochemical characteristics of the fluorite phases in the EuF2 - EuF3 systems are similar to those of the phases in the SrF2 - EuF3 and SrF2 - GdF3 systems due to the similar lattice parameters of the EuF2 and SrF2 components. Europium difluoride supplements the list of fluorite components MF2 ( M = Ca, Sr, Ba, Cd, Pb), which are crystal matrices for nonstoichiometric (nanostructured) fluoride materials M 1 - x R x F2 + x ( R are rare earth elements).

Regulation of the Wnt/β-Catenin Signaling Pathway by Human Papillomavirus E6 and E7 Oncoproteins

PubMed Central

Muñoz Bello, Jesus Omar; Olmedo Nieva, Leslie; Contreras Paredes, Adriana; Fuentes Gonzalez, Alma Mariana; Rocha Zavaleta, Leticia; Lizano, Marcela

2015-01-01

Cell signaling pathways are the mechanisms by which cells transduce external stimuli, which control the transcription of genes, to regulate diverse biological effects. In cancer, distinct signaling pathways, such as the Wnt/β-catenin pathway, have been implicated in the deregulation of critical molecular processes that affect cell proliferation and differentiation. For example, changes in β-catenin localization have been identified in Human Papillomavirus (HPV)-related cancers as the lesion progresses. Specifically, β-catenin relocates from the membrane/cytoplasm to the nucleus, suggesting that this transcription regulator participates in cervical carcinogenesis. The E6 and E7 oncoproteins are responsible for the transforming activity of HPV, and some studies have implicated these viral oncoproteins in the regulation of the Wnt/β-catenin pathway. Nevertheless, new interactions of HPV oncoproteins with cellular proteins are emerging, and the study of the biological effects of such interactions will help to understand HPV-related carcinogenesis. This review addresses the accumulated evidence of the involvement of the HPV E6 and E7 oncoproteins in the activation of the Wnt/β-catenin pathway. PMID:26295406

Oxidative stress in relation to diet and physical activity among premenopausal women.

PubMed

Anderson, Chelsea; Milne, Ginger L; Sandler, Dale P; Nichols, Hazel B

2016-10-01

Higher levels of oxidative stress, as measured by F2-isoprostanes, have been associated with chronic diseases such as CVD and some cancers. Improvements in diet and physical activity may help reduce oxidative stress; however, previous studies regarding associations between lifestyle factors and F2-isoprostane concentrations have been inconsistent. The aim of this cross-sectional study was to investigate whether physical activity and intakes of fruits/vegetables, antioxidant nutrients, dietary fat subgroups and alcohol are associated with concentrations of F2-isoprostane and the major F2-isoprostane metabolite. Urinary F2-isoprostane and its metabolite were measured in urine samples collected at enrolment from 912 premenopausal women (aged 35-54 years) participating in the Sister Study. Physical activity, alcohol consumption and dietary intakes were self-reported via questionnaires. With adjustment for potential confounders, the geometric means of F2-isoprostane and its metabolite were calculated according to quartiles of dietary intakes, alcohol consumption and physical activity, and linear regression models were used to evaluate trends. Significant inverse associations were found between F2-isoprostane and/or its metabolite and physical activity, vegetables, fruits, vitamin C, α-carotene, vitamin E, β-carotene, vitamin A, Se, lutein+zeaxanthin and long-chain n-3 fatty acids. Although trans fats were positively associated with both F2-isoprostane and its metabolite, other dietary fat subgroups including SFA, n-6 fatty acids, n-3 fatty acids, MUFA, PUFA, short-chain n-3 fatty acids, long-chain n-3 fatty acids and total fat were not associated with either F2-isoprostane or its metabolite. Our findings suggest that lower intake of antioxidant nutrients and higher intake of trans fats may be associated with greater oxidative stress among premenopausal women.

ERBB2 Deficiency Alters an E2F-1-Dependent Adaptive Stress Response and Leads to Cardiac Dysfunction

PubMed Central

Perry, Marie-Claude; Dufour, Catherine R.; Eichner, Lillian J.; Tsang, David W. K.; Deblois, Geneviève; Muller, William J.

2014-01-01

The tyrosine kinase receptor ERBB2 is required for normal development of the heart and is a potent oncogene in breast epithelium. Trastuzumab, a monoclonal antibody targeting ERBB2, improves the survival of breast cancer patients, but cardiac dysfunction is a major side effect of the drug. The molecular mechanisms underlying how ERBB2 regulates cardiac function and why trastuzumab is cardiotoxic remain poorly understood. We show here that ERBB2 hypomorphic mice develop cardiac dysfunction that mimics the side effects observed in patients treated with trastuzumab. We demonstrate that this phenotype is related to the critical role played by ERBB2 in cardiac homeostasis and physiological hypertrophy. Importantly, genetic and therapeutic reduction of ERBB2 activity in mice, as well as ablation of ERBB2 signaling by trastuzumab or siRNAs in human cardiomyocytes, led to the identification of an impaired E2F-1-dependent genetic program critical for the cardiac adaptive stress response. These findings demonstrate the existence of a previously unknown mechanistic link between ERBB2 and E2F-1 transcriptional activity in heart physiology and trastuzumab-induced cardiac dysfunction. PMID:25246633

The Production In Vivo of Microcin E492 with Antibacterial Activity Depends on Salmochelin and EntF▿

PubMed Central

Mercado, Gabriela; Tello, Mario; Marín, Macarena; Monasterio, Octavio; Lagos, Rosalba

2008-01-01

Microcin E492 is a channel-forming bacteriocin that is found in two forms, namely, a posttranslationally modified form obtained by the covalent linkage of salmochelin-like molecules to serine 84 and an unmodified form. The production of modified microcin E492 requires the synthesis of enterochelin, which is subsequently glycosylated by MceC and converted into salmochelin. mceC mutants produced inactive microcin E492, and this phenotype was reversed either by complementation with iroB from Salmonella enterica or by the addition of exogenous salmochelin. Cyclic salmochelin uptake by Escherichia coli occurred mainly through the outer membrane catecholate siderophore receptor Fiu. The production of inactive microcin E492 by mutants in entB and entC was reverted by the addition of the end product of the respective mutated pathway (2,3-dihydroxybenzoic acid and enterochelin/salmochelin, respectively), while mutants in entF did not produce active microcin E492 in the presence of enterochelin or salmochelin. The EntF adenylation domain was the only domain required for this microcin E492 maturation step. Inactivation of the enzymatic activity of this domain by site-directed mutagenesis did not prevent the synthesis of active microcin E492 in the presence of salmochelin, indicating that the adenylation activity is not essential for the function of EntF at this stage of microcin E492 maturation. PMID:18502859

DREAMs make plant cells to cycle or to become quiescent.

PubMed

Magyar, Zoltán; Bögre, László; Ito, Masaki

2016-12-01

Cell cycle phase specific oscillation of gene transcription has long been recognized as an underlying principle for ordered processes during cell proliferation. The G1/S-specific and G2/M-specific cohorts of genes in plants are regulated by the E2F and the MYB3R transcription factors. Mutant analysis suggests that activator E2F functions might not be fully required for cell cycle entry. In contrast, the two activator-type MYB3Rs are part of positive feedback loops to drive the burst of mitotic gene expression, which is necessary at least to accomplish cytokinesis. Repressor MYB3Rs act outside the mitotic time window during cell cycle progression, and are important for the shutdown of mitotic genes to impose quiescence in mature organs. The two distinct classes of E2Fs and MYB3Rs together with the RETINOBLATOMA RELATED are part of multiprotein complexes that may be evolutionary related to what is known as DREAM complex in animals. In plants, there are multiple such complexes with distinct compositions and functions that may be involved in the coordinated cell cycle and developmental regulation of E2F targets and mitotic genes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Analysis of a Soluble (UreD:UreF:UreG)2 Accessory Protein Complex and its Interactions with Klebsiella aerogenes Urease by Mass Spectrometry

PubMed Central

Farrugia, Mark A.; Han, Linjie; Zhong, Yueyang; Boer, Jodi L.; Ruotolo, Brandon T.; Hausinger, Robert P.

2013-01-01

Maturation of the nickel-containing urease of Klebsiella aerogenes is facilitated by the UreD, UreF, and UreG accessory proteins along with the UreE metallo-chaperone. A fusion of the maltose binding protein and UreD (MBP-UreD) was co-isolated with UreF and UreG in a soluble complex possessing a (MBP-UreD:UreF:UreG)2 quaternary structure. Within this complex a UreF:UreF interaction was identified by chemical cross-linking of the amino termini of its two UreF protomers, as shown by mass spectrometry of tryptic peptides. A pre-activation complex was formed by the interaction of (MBP-UreD:UreF:UreG)2 and urease. Mass spectrometry of intact protein species revealed a pathway for synthesis of the urease pre-activation complex in which individual hetero-trimer units of the (MBP-UreD:UreF:UreG)2 complex bind to urease. Together, these data provide important new insights into the structures of protein complexes associated with urease activation. PMID:23797863

Gene Expression Profiling Reveals a Massive, Aneuploidy-Dependent Transcriptional Deregulation and Distinct Differences between Lymph Node–Negative and Lymph Node–Positive Colon Carcinomas

PubMed Central

Grade, Marian; Hörmann, Patrick; Becker, Sandra; Hummon, Amanda B.; Wangsa, Danny; Varma, Sudhir; Simon, Richard; Liersch, Torsten; Becker, Heinz; Difilippantonio, Michael J.; Ghadimi, B. Michael; Ried, Thomas

2016-01-01

To characterize patterns of global transcriptional deregulation in primary colon carcinomas, we did gene expression profiling of 73 tumors [Unio Internationale Contra Cancrum stage II (n = 33) and stage III (n = 40)] using oligonucleotide microarrays. For 30 of the tumors, expression profiles were compared with those from matched normal mucosa samples. We identified a set of 1,950 genes with highly significant deregulation between tumors and mucosa samples (P < 1e–7). A significant proportion of these genes mapped to chromosome 20 (P = 0.01). Seventeen genes had a >5-fold average expression difference between normal colon mucosa and carcinomas, including up-regulation of MYC and of HMGA1, a putative oncogene. Furthermore, we identified 68 genes that were significantly differentially expressed between lymph node–negative and lymph node–positive tumors (P < 0.001), the functional annotation of which revealed a preponderance of genes that play a role in cellular immune response and surveillance. The microarray-derived gene expression levels of 20 deregulated genes were validated using quantitative real-time reverse transcription-PCR in >40 tumor and normal mucosa samples with good concordance between the techniques. Finally, we established a relationship between specific genomic imbalances, which were mapped for 32 of the analyzed colon tumors by comparative genomic hybridization, and alterations of global transcriptional activity. Previously, we had conducted a similar analysis of primary rectal carcinomas. The systematic comparison of colon and rectal carcinomas revealed a significant overlap of genomic imbalances and transcriptional deregulation, including activation of the Wnt/β-catenin signaling cascade, suggesting similar pathogenic pathways. PMID:17210682

2-heptyl-formononetin increases cholesterol and induces hepatic steatosis in mice.

PubMed

Andersen, Charlotte; Schjoldager, Janne G; Tortzen, Christian G; Vegge, Andreas; Hufeldt, Majbritt R; Skaanild, Mette T; Vogensen, Finn K; Kristiansen, Karsten; Hansen, Axel K; Nielsen, John

2013-01-01

Consumption of isoflavones may prevent adiposity, hepatic steatosis, and dyslipidaemia. However, studies in the area are few and primarily with genistein. This study investigated the effects of formononetin and its synthetic analogue, 2-heptyl-formononetin (C7F), on lipid and cholesterol metabolism in C57BL/6J mice. The mice were fed a cholesterol-enriched diet for five weeks to induce hypercholesterolemia and were then fed either the cholesterol-enriched diet or the cholesterol-enriched diet-supplemented formononetin or C7F for three weeks. Body weight and composition, glucose homeostasis, and plasma lipids were compared. In another experiment, mice were fed the above diets for five weeks, and hepatic triglyceride accumulation and gene expression and histology of adipose tissue and liver were examined. Supplementation with C7F increased plasma HDL-cholesterol thereby increasing the plasma level of total cholesterol. Supplementation with formononetin did not affect plasma cholesterol but increased plasma triglycerides levels. Supplementation with formononetin and C7F induced hepatic steatosis. However, formononetin decreased markers of inflammation and liver injury. The development of hepatic steatosis was associated with deregulated expression of hepatic genes involved in lipid and lipoprotein metabolism. In conclusion, supplementation with formononetin and C7F to a cholesterol-enriched diet adversely affected lipid and lipoprotein metabolism in C57BL/6J mice.

2-Heptyl-Formononetin Increases Cholesterol and Induces Hepatic Steatosis in Mice

PubMed Central

Andersen, Charlotte; Schjoldager, Janne G.; Tortzen, Christian G.; Vegge, Andreas; Hufeldt, Majbritt R.; Skaanild, Mette T.; Vogensen, Finn K.; Kristiansen, Karsten; Hansen, Axel K.; Nielsen, John

2013-01-01

Consumption of isoflavones may prevent adiposity, hepatic steatosis, and dyslipidaemia. However, studies in the area are few and primarily with genistein. This study investigated the effects of formononetin and its synthetic analogue, 2-heptyl-formononetin (C7F), on lipid and cholesterol metabolism in C57BL/6J mice. The mice were fed a cholesterol-enriched diet for five weeks to induce hypercholesterolemia and were then fed either the cholesterol-enriched diet or the cholesterol-enriched diet-supplemented formononetin or C7F for three weeks. Body weight and composition, glucose homeostasis, and plasma lipids were compared. In another experiment, mice were fed the above diets for five weeks, and hepatic triglyceride accumulation and gene expression and histology of adipose tissue and liver were examined. Supplementation with C7F increased plasma HDL-cholesterol thereby increasing the plasma level of total cholesterol. Supplementation with formononetin did not affect plasma cholesterol but increased plasma triglycerides levels. Supplementation with formononetin and C7F induced hepatic steatosis. However, formononetin decreased markers of inflammation and liver injury. The development of hepatic steatosis was associated with deregulated expression of hepatic genes involved in lipid and lipoprotein metabolism. In conclusion, supplementation with formononetin and C7F to a cholesterol-enriched diet adversely affected lipid and lipoprotein metabolism in C57BL/6J mice. PMID:23738334

High expression of Polycomb group protein EZH2 predicts poor survival in salivary gland adenoid cystic carcinoma.

PubMed

Vékony, H; Raaphorst, F M; Otte, A P; van Lohuizen, M; Leemans, C R; van der Waal, I; Bloemena, E

2008-06-01

The prognosis of adenoid cystic carcinoma (ACC), a malignant salivary gland tumour, depends on clinicopathological parameters. To decipher the biological behaviour of ACC, and to identify patients at risk of developing metastases, additional markers are needed. Expression of the cell cycle proteins p53, cyclin D1, p16(INK4a), E2F1 and Ki-67, together with the Polycomb group (PcG) proteins BMI-1, MEL-18, EZH2 and EED was investigated immunohistochemically 21 formalin-fixed, paraffin-embedded primary ACCs in relation to tumour characteristics. ACC revealed significantly increased expression of the cell cycle proteins compared to normal salivary tissue (n = 17). Members of the two PcG complexes displayed mutually exclusive expression in normal salivary gland tissue, with BMI-1 and MEL-18 being abundantly present. In ACC, this expression pattern was disturbed, with EZH2 and EED showing significantly increased expression levels. In univariate analysis, presence of recurrence, poor differentiation and high EZH2 levels (>25% immunopositivity) significantly correlated with unfavourable outcome. ACCs with high proliferative rate (>25% Ki-67 immunopositivity) significantly correlated with high levels of EZH2 and p16. Only the development of recurrence was an independent prognostic factor of survival in multivariate analysis. Expression of PcG complexes and of essential cell cycle proteins is highly deregulated in ACC. Also, EZH2 expression has prognostic relevance in this malignancy.

3-methyl-2-phenyl-1-substituted-indole derivatives as indomethacin analogs: design, synthesis and biological evaluation as potential anti-inflammatory and analgesic agents.

PubMed

Abdellatif, Khaled R A; Lamie, Phoebe F; Omar, Hany A

2016-01-01

In a new group of 3-methyl-2-phenyl-1-substituted-indole derivatives (10a-f), the indomethacin analogs were prepared via the Fisher indole synthesis reaction of propiophenone with appropriately substituted phenylhydrazine hydrochloride. This is followed by the insertion of the appropriate benzyl or benzoyl fragment. All the synthesized compounds were evaluated for their anti-inflammatory (in vitro and in vivo) and analgesic activities. The methanesulphonyl derivatives 10d, e and f showed the highest anti-inflammatory (in vitro and in vivo) and analgesic activities. In addition, molecular docking studies were performed on compounds 10a-f and the results were in agreement with that obtained from the in vitro COX inhibition assays. The significant anti-inflammatory and analgesic activities exhibited by 10d and 10e warrant continued preclinical development as potential anti-inflammatory and analgesic agents.

Cyclophilin D Promotes Brain Mitochondrial F1FO ATP Synthase Dysfunction in Aging Mice

PubMed Central

Gauba, Esha; Guo, Lan; Du, Heng

2017-01-01

Brain aging is the known strongest risk factor for Alzheimer’s disease (AD). In recent years, mitochondrial deficits have been proposed to be a common mechanism linking brain aging to AD. Therefore, to elucidate the causative mechanisms of mitochondrial dysfunction in aging brains is of paramount importance for our understanding of the pathogenesis of AD, in particular its sporadic form. Cyclophilin D (CypD) is a specific mitochondrial protein. Recent studies have shown that F1FO ATP synthase oligomycin sensitivity conferring protein (OSCP) is a binding partner of CypD. The interaction of CypD with OSCP modulates F1FO ATP synthase function and mediates mitochondrial permeability transition pore (mPTP) opening. Here, we have found that increased CypD expression, enhanced CypD/OSCP interaction, and selective loss of OSCP are prominent brain mitochondrial changes in aging mice. Along with these changes, brain mitochondria from the aging mice demonstrated decreased F1FO ATP synthase activity and defective F1FO complex coupling. In contrast, CypD deficient mice exhibited substantially mitigated brain mitochondrial F1FO ATP synthase dysfunction with relatively preserved mitochondrial function during aging. Interestingly, the aging-related OSCP loss was also dramatically attenuated by CypD depletion. Therefore, the simplest interpretation of this study is that CypD promotes F1FO ATP synthase dysfunction and the resultant mitochondrial deficits in aging brains. In addition, in view of CypD and F1FO ATP synthase alterations seen in AD brains, the results further suggest that CypD-mediated F1FO ATP synthase deregulation is a shared mechanism linking mitochondrial deficits in brain aging and AD. PMID:27834780

Cyclophilin D Promotes Brain Mitochondrial F1FO ATP Synthase Dysfunction in Aging Mice.

PubMed

Gauba, Esha; Guo, Lan; Du, Heng

2017-01-01

Brain aging is the known strongest risk factor for Alzheimer's disease (AD). In recent years, mitochondrial deficits have been proposed to be a common mechanism linking brain aging to AD. Therefore, to elucidate the causative mechanisms of mitochondrial dysfunction in aging brains is of paramount importance for our understanding of the pathogenesis of AD, in particular its sporadic form. Cyclophilin D (CypD) is a specific mitochondrial protein. Recent studies have shown that F1FO ATP synthase oligomycin sensitivity conferring protein (OSCP) is a binding partner of CypD. The interaction of CypD with OSCP modulates F1FO ATP synthase function and mediates mitochondrial permeability transition pore (mPTP) opening. Here, we have found that increased CypD expression, enhanced CypD/OSCP interaction, and selective loss of OSCP are prominent brain mitochondrial changes in aging mice. Along with these changes, brain mitochondria from the aging mice demonstrated decreased F1FO ATP synthase activity and defective F1FO complex coupling. In contrast, CypD deficient mice exhibited substantially mitigated brain mitochondrial F1FO ATP synthase dysfunction with relatively preserved mitochondrial function during aging. Interestingly, the aging-related OSCP loss was also dramatically attenuated by CypD depletion. Therefore, the simplest interpretation of this study is that CypD promotes F1FO ATP synthase dysfunction and the resultant mitochondrial deficits in aging brains. In addition, in view of CypD and F1FO ATP synthase alterations seen in AD brains, the results further suggest that CypD-mediated F1FO ATP synthase deregulation is a shared mechanism linking mitochondrial deficits in brain aging and AD.

HPV: Molecular pathways and targets.

PubMed

Gupta, Shilpi; Kumar, Prabhat; Das, Bhudev C

2018-04-05

Infection of high-risk human papillomaviruses (HPVs) is a prerequisite for the development of cervical carcinoma. HPV infections are also implicated in the development of other types of carcinomas. Chronic or persistent infection of HPV is essential but HPV alone is inadequate, additional endogenous or exogenous cues are needed along with HPV to induce cervical carcinogenesis. The strategies that high-risk HPVs have developed in differentiating epithelial cells to reach a DNA-synthesis competent state leading to tumorigenic transformation are basically due to overexpression of the E6 and E7 oncoproteins and the activation of diverse cellular regulatory or signaling pathways that are targeted by them. Moreover, the Wnt/β-catenin/Notch and phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathways are deregulated in various cancers, and have also been implicated in HPV-induced cancers. These are basically related to the "cancer hallmarks," and include sustaining proliferative signals, the evasion of growth suppression and immune destruction, replicative immortality, inflammation, invasion, metastasis and angiogenesis, as well as genome instability, resisting cell death, and deregulation of cellular energetics. These information could eventually aid in identifying or developing new diagnostic, prognostic biomarkers, and may contribute to design more effective targeted therapeutics and treatment strategies. Although surgery, chemotherapy and radiotherapy can cure more than 90% of women with early stage cervical cancer, the recurrent and metastatic disease remains a major cause of cancer mortality. Numerous efforts have been made to design new drugs and develop gene therapies to treat cervical cancer. In recent years, research on treatment strategies has proposed several options, including the role of HPV E5, E6, and E7 oncogenes, which are retained and overexpressed in most of the cervical cancers and whose respective oncoproteins are critical to the induction and maintenance of the malignant phenotype. Other efforts have been focused on antitumor immunotherapy strategies. It is known that during the development of cervical cancer, a cascade of abnormal events is induced, including disruption of cell cycle control, perturbation of antitumor immune response, alteration of gene expression, deregulation of microRNA and cancer stem cell and stemness related markers expression could serve as novel molecular targets for reliable diagnosis and treatment of HPV-positive cancers. However, the search for new proposals for disease control and prevention has brought new findings and approaches in the context of molecular biology indicating innovations and perspectives in the early detection and prevention of the disease. Thus, in this article, we discuss molecular signaling pathways activated by HPV and potential targets or biomarkers for early detection or prevention and the treatment of HPV-associated cancers. Copyright © 2018 Elsevier Inc. All rights reserved.

Urinary Exosomal miRNA Signature in Type II Diabetic Nephropathy Patients

PubMed Central

Delić, Denis; Eisele, Claudia; Schmid, Ramona; Baum, Patrick; Wiech, Franziska; Gerl, Martin; Zimdahl, Heike; Pullen, Steven S.; Urquhart, Richard

2016-01-01

MicroRNAs (miRNAs) are short non-coding RNA species which are important post-transcriptional regulators of gene expression and play an important role in the pathogenesis of diabetic nephropathy. miRNAs are present in urine in a remarkably stable form packaged in extracellular vesicles, predominantly exosomes. In the present study, urinary exosomal miRNA profiling was conducted in urinary exosomes obtained from 8 healthy controls (C), 8 patients with type II diabetes (T2D) and 8 patients with type II diabetic nephropathy (DN) using Agilent´s miRNA microarrays. In total, the expression of 16 miRNA species was deregulated (>2-fold) in DN patients compared to healthy donors and T2D patients: the expression of 14 miRNAs (miR-320c, miR-6068, miR-1234-5p, miR-6133, miR-4270, miR-4739, miR-371b-5p, miR-638, miR-572, miR-1227-5p, miR-6126, miR-1915-5p, miR-4778-5p and miR-2861) was up-regulated whereas the expression of 2 miRNAs (miR-30d-5p and miR-30e-5p) was down-regulated. Most of the deregulated miRNAs are involved in progression of renal diseases. Deregulation of urinary exosomal miRNAs occurred in micro-albuminuric DN patients but not in normo-albuminuric DN patients. We used qRT-PCR based analysis of the most strongly up-regulated miRNAs in urinary exosomes from DN patients, miRNAs miR-320c and miR-6068. The correlation of miRNA expression and micro-albuminuria levels could be replicated in a confirmation cohort. In conclusion, urinary exosomal miRNA content is altered in type II diabetic patients with DN. Deregulated miR-320c, which might have an impact on the TGF-β-signaling pathway via targeting thrombospondin 1 (TSP-1) shows promise as a novel candidate marker for disease progression in type II DN that should be evaluated in future studies. PMID:26930277

Role of ubiquitin and the HPV E6 oncoprotein in E6AP-mediated ubiquitination

PubMed Central

Mortensen, Franziska; Schneider, Daniel; Barbic, Tanja; Sladewska-Marquardt, Anna; Kühnle, Simone; Marx, Andreas; Scheffner, Martin

2015-01-01

Deregulation of the ubiquitin ligase E6 associated protein (E6AP) encoded by the UBE3A gene has been associated with three different clinical pictures. Hijacking of E6AP by the E6 oncoprotein of distinct human papillomaviruses (HPV) contributes to the development of cervical cancer, whereas loss of E6AP expression or function is the cause of Angelman syndrome, a neurodevelopmental disorder, and increased expression of E6AP has been involved in autism spectrum disorders. Although these observations indicate that the activity of E6AP has to be tightly controlled, only little is known about how E6AP is regulated at the posttranslational level. Here, we provide evidence that the hydrophobic patch of ubiquitin comprising Leu-8 and Ile-44 is important for E6AP-mediated ubiquitination, whereas it does not affect the catalytic properties of the isolated catalytic HECT domain of E6AP. Furthermore, we show that the HPV E6 oncoprotein rescues the disability of full-length E6AP to use a respective hydrophobic patch mutant of ubiquitin for ubiquitination and that it stimulates E6AP-mediated ubiquitination of Ring1B, a known substrate of E6AP, in vitro and in cells. Based on these data, we propose that E6AP exists in at least two different states, an active and a less active or latent one, and that the activity of E6AP is controlled by noncovalent interactions with ubiquitin and allosteric activators such as the HPV E6 oncoprotein. PMID:26216987

In Vitro Progression of HPV16 Episome-Associated Cervical Neoplasia Displays Fundamental Similarities to Integrant-Associated Carcinogenesis

PubMed Central

Gray, Elizabeth; Pett, Mark R.; Ward, Dawn; Winder, David M.; Stanley, Margaret A.; Roberts, Ian; Scarpini, Cinzia G.; Coleman, Nicholas

2010-01-01

An important event in the development of cervical squamous cell carcinoma (SCC) is deregulated expression of high-risk human papillomavirus (HR-HPV) oncogenes, most commonly related to viral integration into host DNA. Mechanisms of development of the ~15% of SCCs that contain extra-chromosomal (episomal) HR-HPV are poorly understood, due to limited longitudinal data. We therefore employed the W12 model to study mechanisms of cervical carcinogenesis associated with episomal HPV16. In vitro progression of W12 normally occurs through selection of cells containing integrated HPV16. However, in one long-term culture, keratinocytes developed a selective growth advantage and invasive phenotype, while retaining HPV16 episomes at increased copy number in the absence of transcriptionally active integrants. Longitudinal investigations revealed similarities between the episome- and integrant-associated routes of neoplastic progression. Most notable were dynamic changes in viral early gene expression in episome-retaining cells, consistent with continually changing selective pressures. An early increase in viral transcription preceded elevated episome copy number and was followed by a reduction to near baseline after the development of invasiveness. Episomal transcriptional deregulation did not require selection of a specific sequence variant of the HPV16 upstream regulatory region, although increased levels of acetylated histone H4 around the late promoter implicated a role for altered chromatin structure. Interestingly, invasive episome-retaining cells demonstrated high levels of HPV16-E2/E6 proteins (despite decreased transcript levels) and reduced expression of interferon-stimulated genes, adaptations that support viral persistence and cell survival. Our findings suggest a unified working model for events important in cervical neoplastic progression, regardless of HR-HPV physical state. PMID:20442284

The Cdk4-E2f1 pathway regulates early pancreas development by targeting Pdx1+ progenitors and Ngn3+ endocrine precursors

PubMed Central

Kim, So Yoon; Rane, Sushil G.

2011-01-01

Cell division and cell differentiation are intricately regulated processes vital to organ development. Cyclin-dependent kinases (Cdks) are master regulators of the cell cycle that orchestrate the cell division and differentiation programs. Cdk1 is essential to drive cell division and is required for the first embryonic divisions, whereas Cdks 2, 4 and 6 are dispensable for organogenesis but vital for tissue-specific cell development. Here, we illustrate an important role for Cdk4 in regulating early pancreas development. Pancreatic development involves extensive morphogenesis, proliferation and differentiation of the epithelium to give rise to the distinct cell lineages of the adult pancreas. The cell cycle molecules that specify lineage commitment within the early pancreas are unknown. We show that Cdk4 and its downstream transcription factor E2f1 regulate mouse pancreas development prior to and during the secondary transition. Cdk4 deficiency reduces embryonic pancreas size owing to impaired mesenchyme development and fewer Pdx1+ pancreatic progenitor cells. Expression of activated Cdk4R24C kinase leads to increased Nkx2.2+ and Nkx6.1+ cells and a rise in the number and proliferation of Ngn3+ endocrine precursors, resulting in expansion of the β cell lineage. We show that E2f1 binds and activates the Ngn3 promoter to modulate Ngn3 expression levels in the embryonic pancreas in a Cdk4-dependent manner. These results suggest that Cdk4 promotes β cell development by directing E2f1-mediated activation of Ngn3 and increasing the pool of endocrine precursors, and identify Cdk4 as an important regulator of early pancreas development that modulates the proliferation potential of pancreatic progenitors and endocrine precursors. PMID:21490060

Giardia lamblia: identification of molecules that contribute to direct mast cell activation.

PubMed

Muñoz-Cruz, Samira; Gomez-García, Argelia; Matadamas-Martínez, Félix; Alvarado-Torres, Juan A; Meza-Cervantez, Patricia; Arriaga-Pizano, Lourdes; Yépez-Mulia, Lilián

2018-06-02

Mast cells play a central role in the early clearance of the intestinal parasite Giardia lamblia. In a previous study, we reported that G. lamblia live trophozoites or trophozoite-derived total soluble extract induced direct activation (IgE-independent) of mast cells and release of IL-6 and TNF-α. To identify the Giardia molecules and the mast cell receptors involved in this activation, trophozoite-derived total soluble proteins separated into three fractions (F1-F3) were evaluated for its ability to activate mast cells in vitro. F2 activated mast cells in a greater extent than F1 and F3. Furthermore, F2 induced the release of IL-6 and TNF-α by mast cells. TLR2 and TLR4 expression increased slightly after mast cell stimulation with either F2 or total soluble extract; however, these receptors were not involved in F2 or total soluble extract-induced proinflammatory cytokine production. Proteins present in F2 as unique and high-intensity bands identified by liquid chromatography coupled with tandem mass spectrometry, include molecules with important biological activities such as enolase and arginine deiminase (ADI). Recombinant ADI and enolase were tested for their ability to activate mast cells, but only ADI induced a significant release of IL-6 and TNF-α. ADI product, citrulline but not ammonium, also induced mast cell release of TNF-α. Interestingly, recombinant ADI still stimulated the secretion of TNF-α by mast cells in a arginine-free medium, although in a lower extend that in the presence of arginine, indicating that either ADI itself can stimulate mast cells or through its metabolic product, citrulline.

Proteinases secreted by Fasciola hepatica degrade extracellular matrix and basement membrane components.

PubMed

Berasaín, P; Goñi, F; McGonigle, S; Dowd, A; Dalton, J P; Frangione, B; Carmona, C

1997-02-01

The invasive stages of the parasitic trematode Fasciola hepatica release proteinases into the medium in which they are maintained. In this study, we investigated the interaction of F. hepatica excretory/secretory (E/S) products and 2 cysteine proteinases (CL1 and CL2) purified from these products with extracellular matrix and basement membrane macromolecules. Fasciola hepatica E/S products contained collagenolytic activity on fibrillar types I and III collagen as well as basement membrane type IV collagen. CL1 and CL2 were capable of degrading acid-soluble type III and type IV collagen but not insoluble type I collagen. In contrast, neither the E/S products nor the purified CL1 and CL2 showed elastinolytic activity. Fibronectin and laminin were degraded by E/S products and by CL1 and CL2. Sequence analysis of fibronectin degradation products showed that the fragments obtained corresponded to complete biologically active domains. These results indicate that the cysteine proteinases secreted by F. hepatica may be involved in the process of tissue invasion by the parasite.

The Molecular Chaperone Hsp90 Is Required for Cell Cycle Exit in Drosophila melanogaster

PubMed Central

Bandura, Jennifer L.; Jiang, Huaqi; Nickerson, Derek W.; Edgar, Bruce A.

2013-01-01

The coordination of cell proliferation and differentiation is crucial for proper development. In particular, robust mechanisms exist to ensure that cells permanently exit the cell cycle upon terminal differentiation, and these include restraining the activities of both the E2F/DP transcription factor and Cyclin/Cdk kinases. However, the full complement of mechanisms necessary to restrain E2F/DP and Cyclin/Cdk activities in differentiating cells are not known. Here, we have performed a genetic screen in Drosophila melanogaster, designed to identify genes required for cell cycle exit. This screen utilized a PCNA-miniwhite+ reporter that is highly E2F-responsive and results in a darker red eye color when crossed into genetic backgrounds that delay cell cycle exit. Mutation of Hsp83, the Drosophila homolog of mammalian Hsp90, results in increased E2F-dependent transcription and ectopic cell proliferation in pupal tissues at a time when neighboring wild-type cells are postmitotic. Further, these Hsp83 mutant cells have increased Cyclin/Cdk activity and accumulate proteins normally targeted for proteolysis by the anaphase-promoting complex/cyclosome (APC/C), suggesting that APC/C function is inhibited. Indeed, reducing the gene dosage of an inhibitor of Cdh1/Fzr, an activating subunit of the APC/C that is required for timely cell cycle exit, can genetically suppress the Hsp83 cell cycle exit phenotype. Based on these data, we propose that Cdh1/Fzr is a client protein of Hsp83. Our results reveal that Hsp83 plays a heretofore unappreciated role in promoting APC/C function during cell cycle exit and suggest a mechanism by which Hsp90 inhibition could promote genomic instability and carcinogenesis. PMID:24086162

The molecular chaperone Hsp90 is required for cell cycle exit in Drosophila melanogaster.

PubMed

Bandura, Jennifer L; Jiang, Huaqi; Nickerson, Derek W; Edgar, Bruce A

2013-01-01

The coordination of cell proliferation and differentiation is crucial for proper development. In particular, robust mechanisms exist to ensure that cells permanently exit the cell cycle upon terminal differentiation, and these include restraining the activities of both the E2F/DP transcription factor and Cyclin/Cdk kinases. However, the full complement of mechanisms necessary to restrain E2F/DP and Cyclin/Cdk activities in differentiating cells are not known. Here, we have performed a genetic screen in Drosophila melanogaster, designed to identify genes required for cell cycle exit. This screen utilized a PCNA-miniwhite(+) reporter that is highly E2F-responsive and results in a darker red eye color when crossed into genetic backgrounds that delay cell cycle exit. Mutation of Hsp83, the Drosophila homolog of mammalian Hsp90, results in increased E2F-dependent transcription and ectopic cell proliferation in pupal tissues at a time when neighboring wild-type cells are postmitotic. Further, these Hsp83 mutant cells have increased Cyclin/Cdk activity and accumulate proteins normally targeted for proteolysis by the anaphase-promoting complex/cyclosome (APC/C), suggesting that APC/C function is inhibited. Indeed, reducing the gene dosage of an inhibitor of Cdh1/Fzr, an activating subunit of the APC/C that is required for timely cell cycle exit, can genetically suppress the Hsp83 cell cycle exit phenotype. Based on these data, we propose that Cdh1/Fzr is a client protein of Hsp83. Our results reveal that Hsp83 plays a heretofore unappreciated role in promoting APC/C function during cell cycle exit and suggest a mechanism by which Hsp90 inhibition could promote genomic instability and carcinogenesis.

Deregulation of the endogenous C/EBPβ LIP isoform predisposes to tumorigenesis.

PubMed

Bégay, Valérie; Smink, Jeske J; Loddenkemper, Christoph; Zimmermann, Karin; Rudolph, Cornelia; Scheller, Marina; Steinemann, Doris; Leser, Ulf; Schlegelberger, Brigitte; Stein, Harald; Leutz, Achim

2015-01-01

Two long and one truncated isoforms (termed LAP*, LAP, and LIP, respectively) of the transcription factor CCAAT enhancer binding protein beta (C/EBPβ) are expressed from a single intronless Cebpb gene by alternative translation initiation. Isoform expression is sensitive to mammalian target of rapamycin (mTOR)-mediated activation of the translation initiation machinery and relayed through an upstream open reading frame (uORF) on the C/EBPβ mRNA. The truncated C/EBPβ LIP, initiated by high mTOR activity, has been implied in neoplasia, but it was never shown whether endogenous C/EBPβ LIP may function as an oncogene. In this study, we examined spontaneous tumor formation in C/EBPβ knockin mice that constitutively express only the C/EBPβ LIP isoform from its own locus. Our data show that deregulated C/EBPβ LIP predisposes to oncogenesis in many tissues. Gene expression profiling suggests that C/EBPβ LIP supports a pro-tumorigenic microenvironment, resistance to apoptosis, and alteration of cytokine/chemokine expression. The results imply that enhanced translation reinitiation of C/EBPβ LIP promotes tumorigenesis. Accordingly, pharmacological restriction of mTOR function might be a therapeutic option in tumorigenesis that involves enhanced expression of the truncated C/EBPβ LIP isoform. Elevated C/EBPβ LIP promotes cancer in mice. C/EBPβ LIP is upregulated in B-NHL. Deregulated C/EBPβ LIP alters apoptosis and cytokine/chemokine networks. Deregulated C/EBPβ LIP may support a pro-tumorigenic microenvironment.

Discovering the Deregulated Molecular Functions Involved in Malignant Transformation of Endometriosis to Endometriosis-Associated Ovarian Carcinoma Using a Data-Driven, Function-Based Analysis

PubMed Central

Chang, Chia-Ming; Yang, Yi-Ping; Chuang, Jen-Hua; Chuang, Chi-Mu; Lin, Tzu-Wei; Wang, Peng-Hui; Yu, Mu-Hsien

2017-01-01

The clinical characteristics of clear cell carcinoma (CCC) and endometrioid carcinoma EC) are concomitant with endometriosis (ES), which leads to the postulation of malignant transformation of ES to endometriosis-associated ovarian carcinoma (EAOC). Different deregulated functional areas were proposed accounting for the pathogenesis of EAOC transformation, and there is still a lack of a data-driven analysis with the accumulated experimental data in publicly-available databases to incorporate the deregulated functions involved in the malignant transformation of EOAC. We used the microarray gene expression datasets of ES, CCC and EC downloaded from the National Center for Biotechnology Information Gene Expression Omnibus (NCBI GEO) database. Then, we investigated the pathogenesis of EAOC by a data-driven, function-based analytic model with the quantified molecular functions defined by 1454 Gene Ontology (GO) term gene sets. This model converts the gene expression profiles to the functionome consisting of 1454 quantified GO functions, and then, the key functions involving the malignant transformation of EOAC can be extracted by a series of filters. Our results demonstrate that the deregulated oxidoreductase activity, metabolism, hormone activity, inflammatory response, innate immune response and cell-cell signaling play the key roles in the malignant transformation of EAOC. These results provide the evidence supporting the specific molecular pathways involved in the malignant transformation of EAOC. PMID:29113136

Regulation of Herpes Simplex Virus Glycoprotein-Induced Cascade of Events Governing Cell-Cell Fusion

PubMed Central

Saw, Wan Ting; Eisenberg, Roselyn J.; Cohen, Gary H.

2016-01-01

ABSTRACT Receptor-dependent herpes simplex virus (HSV)-induced cell-cell fusion requires glycoproteins gD, gH/gL, and gB. Our current model posits that during fusion, receptor-activated conformational changes in gD activate gH/gL, which subsequently triggers the transformation of the prefusion form of gB into a fusogenic state. To examine the role of each glycoprotein in receptor-dependent cell-cell fusion, we took advantage of our discovery that fusion by wild-type herpes simplex virus 2 (HSV-2) glycoproteins occurs twice as fast as that achieved by HSV-1 glycoproteins. By sequentially swapping each glycoprotein between the two serotypes, we established that fusion speed was governed by gH/gL, with gH being the main contributor. While the mutant forms of gB fuse at distinct rates that are dictated by their molecular structure, these restrictions can be overcome by gH/gL of HSV-2 (gH2/gL2), thereby enhancing their activity. We also found that deregulated forms of gD of HSV-1 (gD1) and gH2/gL2 can alter the fusogenic potential of gB, promoting cell fusion in the absence of a cellular receptor, and that deregulated forms of gB can drive the fusion machinery to even higher levels. Low pH enhanced fusion by affecting the structure of both gB and gH/gL mutants. Together, our data highlight the complexity of the fusion machinery, the impact of the activation state of each glycoprotein on the fusion process, and the critical role of gH/gL in regulating HSV-induced fusion. IMPORTANCE Cell-cell fusion mediated by HSV glycoproteins requires gD, gH/gL, gB, and a gD receptor. Here, we show that fusion by wild-type HSV-2 glycoproteins occurs twice as fast as that achieved by HSV-1 glycoproteins. By sequentially swapping each glycoprotein between the two serotypes, we found that the fusion process was controlled by gH/gL. Restrictions imposed on the gB structure by mutations could be overcome by gH2/gL2, enhancing the activity of the mutants. Under low-pH conditions or when using deregulated forms of gD1 and gH2/gL2, the fusogenic potential of gB could only be increased in the absence of receptor, underlining the exquisite regulation that occurs in the presence of receptor. Our data highlight the complexity of the fusion machinery, the impact of the activation state of each glycoprotein on the fusion process, and the critical role of gH/gL in regulating HSV-induced fusion. PMID:27630245

Limazepines A-F, pyrrolo[1,4]benzodiazepine Antibiotics from an Indonesian Micrococcus sp.

PubMed

Fotso, Serge; Zabriskie, T Mark; Proteau, Philip J; Flatt, Patricia M; Santosa, Dwi Andreas; Mahmud, Taifo

2009-04-01

In our screening of Indonesian microorganisms for novel bioactive natural products we have isolated seven new compounds, designated as limazepines A, B1 and B2 (isolated as an isomeric mixture), C, D, E, and F, from the culture broth of Micrococcus sp. strain ICBB 8177. In addition, the known natural products prothracarcin and 7-O-succinylmacrolactin A, as well as two previously reported synthetic compounds, 2-amino-3-hydroxy-4-methoxybenzoic acid methyl ester and 4-ethylpyrrole-2-carboxaldehyde, were obtained from the extract. Chemical structures were determined by spectroscopic methods and by comparison with the NMR data of structurally related compounds. The limazepines belong to the growing group of the pyrrolo[1,4]benzodiazepine antitumor antibiotics isolated from various soil bacteria. Limazepines B1/B2 mixture, C, and E were active against the Gram-positive bacterium Staphylococcus aureus and the Gram-negative bacterium Escherichia coli. Limazepine D was also active against S. aureus, but was not active against E. coli. Interestingly, only the limazepines B1/B2 mixture and D were active against Pseudomonas aeruginosa.

Census of U.S. Civil Aircraft. Calendar Year 1982.

DTIC Science & Technology

1982-12-31

is partly due to the deregulation of the airlines under the Airline Deregulation Act of 1978 and the associated entry of new carriers. The increase is...Airlift Associates 2 ..--- --- --- 2 Air Link 1 --- --- --- -- 1 Air Logistics of Alaska, Inc A .. ....... 4 --- Air Mark Corp. 1 --- I --- 1-- ... Air...Mid South Airlines, Inc. 3 -- --- --- --- 2 -- I Mississippi Valley 14 --- --- --- --- 14 ... ..... Mountain Nose Air Service 3

Automated cGMP-compliant radiosynthesis of [18 F]-(E)-PSS232 for brain PET imaging of metabotropic glutamate receptor subtype 5.

PubMed

Park, Jun Young; Son, Jeongmin; Yun, Mijin; Ametamey, Simon M; Chun, Joong-Hyun

2018-01-01

(E)-3-(Pyridin-2-yl ethynyl)cyclohex-2-enone O-(3-(2-[ 18 F]-fluoroethoxy)propyl) oxime ([ 18 F]-(E)-PSS232, [ 18 F]2a) is a recently developed radiotracer that can be used to visualize metabotropic glutamate receptor subtype 5 (mGlu 5 ) in vivo. The mGlu 5 has become an attractive therapeutic and diagnostic target owing to its role in many neuropsychiatric disorders. Several carbon-11-labeled and fluorine-18-labeled radiotracers have been developed to measure mGlu 5 receptor occupancy in the human brain. The radiotracer [ 18 F]2a, which is used as an analogue for [ 11 C]ABP688 ([ 11 C]1) and has a longer physical half-life, is a selective radiotracer that exhibits high binding affinity for mGlu 5 . Herein, we report the fully automated radiosynthesis of [ 18 F]2a using a commercial GE TRACERlab™ FX- FN synthesizer for routine production and distribution to nearby satellite clinics. Nucleophilic substitution of the corresponding mesylate precursor with cyclotron-produced [ 18 F]fluoride ion at 100°C in dimethyl sulfoxide (DMSO), followed by high-performance liquid chromatography (HPLC) purification and formulation, readily provided [ 18 F]2a with a radiochemical yield of 40 ± 2% (decay corrected, n = 5) at the end of synthesis. Radiochemical purity for the [ 18 F]-(E)-conformer was greater than 95%. Molar activity was determined to be 63.6 ± 9.6 GBq/μmol (n = 5), and the overall synthesis time was 70 minutes. Copyright © 2017 John Wiley & Sons, Ltd.

The adenovirus oncoprotein E1a stimulates binding of transcription factor ETF to transcriptionally activate the p53 gene.

PubMed

Hale, T K; Braithwaite, A W

1999-08-20

Expression of the tumor suppressor protein p53 plays an important role in regulating the cellular response to DNA damage. During adenovirus infection, levels of p53 protein also increase. It has been shown that this increase is due not only to increased stability of the p53 protein but to the transcriptional activation of the p53 gene during infection. We demonstrate here that the E1a proteins of adenovirus are responsible for activating the mouse p53 gene and that both major E1a proteins, 243R and 289R, are required for complete activation. E1a brings about the binding of two cellular transcription factors to the mouse p53 promoter. One of these, ETF, binds to three upstream sites in the p53 promoter and one downstream site, whereas E2F binds to one upstream site in the presence of E1a. Our studies indicate that E2F binding is not essential for activation of the p53 promoter but that ETF is. Our data indicate the ETF site located downstream of the start site of transcription is the key site in conferring E1a responsiveness on the p53 promoter.

Innate Immunity Dysregulation in Myelodysplastic Syndromes

DTIC Science & Technology

2014-10-01

the CD34+ enriched MDS bone marrow hematopoietic stem/ progenitor cells . We also demonstrated that interference of the TLR2-JMJD3 innate immunity...able to demonstrate that TLR2 innate immune signaling is excessively activated in MDS bone marrow stem/ progenitor cells and that inhibiting this...evidence that the deregulation of innate immune and inflammatory signaling also 13 affects other cells from the immune system and the bone marrow

Further studies on the role of prostaglandin in fever

PubMed Central

Dey, P. K.; Feldberg, W.; Gupta, K. P.; Milton, A. S.; Wendlandt, Sabine

1974-01-01

1. Experiments were carried out in unanaesthetized cats to find out if a prostaglandin is the mediator (a) for the long lasting fever which often follows injections of phsyiological salt solutions into the cerebral ventricles or into the cisterna magna, as well as their perfusions through the cerebral ventricles, and (b) for the sodium fever which occurs during a perfusion of the cerebral ventricles with calcium-free artificial c.s.f. A fever mediated by prostaglandin should be accompanied by an increase of prostaglandin activity in cisternal c.s.f., and be abolished or prevented by antipyretics like paracetamol or indomethacin which inhibit prostaglandin synthesis. Both criteria were applied. 2. The fever which follows injections or perfusions of physiological salt solutions appears to be mediated by a prostaglandin of the E series, probably E2 (PGE2) because it was accompanied by increased prostaglandin E-like activity in the c.s.f. and abolished by paracetamol and indomethacin. During the first few days after pre-treatment of the cats with intramuscular chloramphenicol the injections were rarely followed by fever. 3. The fever which occurs during a perfusion with calcium-free artificial c.s.f. appears not to be mediated by prostaglandin, because it was not associated with increased prostaglandin activity in the cisternal effluent, and not prevented by paracetamol or indomethacin, although these antipyretics usually attenuated the fever. 4. A perfusion of the cerebral ventricles with artificial c.s.f. containing calcium in an abnormally high concentration (6·25 mM) brought down fever produced by PGE1, or PGE2, or bacterial pyrogen. PMID:4215879

NmF2 Morphology during four-classes of solar and magnetic activity conditions at an African station around the EIA trough and comparison with IRI-2016 Map

NASA Astrophysics Data System (ADS)

Adebesin, B.; Rabiu, B.; Obrou, O. K.

2017-12-01

Better understanding of the electrodynamics between parameters used in describing the ionospheric layer and their solar and geomagnetic influences goes a long way in furthering the expansion of space weather knowledge. Telecommunication and scientific radar launch activities can however be interrupted either on a larger/smaller scales by geomagnetic activities which is susceptible to changes in solar activity and effects. Consequently, the ionospheric NmF2 electrodynamics was investigated for a station near the magnetic dip in the African sector (Korhogo, Geomagnetic: -1.26°N, 67.38°E). Data covering years 1996 and 2000 were investigated for four categories of magnetic and solar activities viz (i) F10.7 < 85 sfu, ap ≤ 7 nT (low solar quiet, LSQ); (ii) F10.7 < 85 sfu, ap > 7 nT (low solar disturbed, LSD); (iii) F10.7 > 150 sfu, ap ≤ 7 nT (high solar quiet, HSQ); and (iv) F10.7 > 150 sfu, ap > 7 nT (high solar disturbed, HSD). NmF2 revealed a pre-noon peak higher than the post-noon peak during high solar activity irrespective of magnetic activity condition and overturned during low solar activity. Higher NmF2 peak amplitude however characterise disturbed magnetic activity than quiet magnetic condition for any solar activity. The maximum pre-/post-noon peaks appeared in equinox season. June solstice noon-time bite out lagged other seasons by 1-2 h. Daytime variability increases with increasing magnetic activity. Equinox/June solstice recorded the highest pre-sunrise/post-sunset peak variability magnitudes with the lowest emerging in June solstice/equinox for all solar and magnetic conditions. The nighttime annual variability amplitude is higher during disturbed than quiet condition regardless of solar activity period; while the range is similar for daytime observations. The noon-time trough characteristics is not significant in the IRI NmF2 pattern during high solar activity but evident during low solar conditions. IRI-2016 map performed best during disturbed activity conditions especially for F10.7 < 85 sfu, ap > 7 nT condition.

E2F function in muscle growth is necessary and sufficient for viability in Drosophila

PubMed Central

Zappia, Maria Paula; Frolov, Maxim V.

2016-01-01

The E2F transcription factor is a key cell cycle regulator. However, the inactivation of the entire E2F family in Drosophila is permissive throughout most of animal development until pupation when lethality occurs. Here we show that E2F function in the adult skeletal muscle is essential for animal viability since providing E2F function in muscles rescues the lethality of the whole-body E2F-deficient animals. Muscle-specific loss of E2F results in a significant reduction in muscle mass and thinner myofibrils. We demonstrate that E2F is dispensable for proliferation of muscle progenitor cells, but is required during late myogenesis to directly control the expression of a set of muscle-specific genes. Interestingly, E2f1 provides a major contribution to the regulation of myogenic function, while E2f2 appears to be less important. These findings identify a key function of E2F in skeletal muscle required for animal viability, and illustrate how the cell cycle regulator is repurposed in post-mitotic cells. PMID:26823289

Small business support of youth physical activity opportunities.

PubMed

Suminski, Richard R; Ding, Ding

2012-01-01

Describe small business support for youth physical activity opportunities (YPAO) and identify factors associated with this support. Cross-sectional analysis of quantitative data relating business characteristics and support for YPAO. Eight demographically heterogeneous, urban neighborhoods in a Midwest metropolitan area. Adult small business owners (n = 90; 65% response rate; mean age 48.4 years; 73.3% male; 45.2% minority). Neighborhood demographics from the 2000 U.S. Census and self-reported business and owner characteristics. Multivariate analysis of variance was used to contrast business and owner characteristics between businesses that did and did not support YPAO. Businesses supporting YPAO had larger annual operating (F = 7.6; p = .018) and advertising budgets (F = 8.5; p = .009) and had younger owners (F = 6.1; p = .034), with sports backgrounds (χ(2) = 5.6; p = .018) and who felt businesses should support YPAO (χ(2) = 3.8; p = .048). Of the 46 businesses not supporting YPAO, 82.6% felt small businesses should support YPAO. The major reasons for nonsupport were difficulty identifying YPAO to support and not being asked for support. Business (e.g., budgets) and business owner characteristics (e.g., age), owner connectedness with YPAO, and the approach used for garnering support (active solicitation, clearly defined support mechanism) were associated with supporting YPAO. Additional business (e.g., annual revenues), owner (e.g., perceptions of YPAO), and environmental (e.g., crime rate, land use) factors should be examined as potential correlates.

Anti-inflammatory and acetylcholinesterase activity of extract, fractions and five compounds isolated from the leaves and twigs of Artemisia annua growing in Cameroon.

PubMed

Chougouo, Rosine D K; Nguekeu, Yves M M; Dzoyem, Jean P; Awouafack, Maurice D; Kouamouo, Jonas; Tane, Pierre; McGaw, Lyndy J; Eloff, Jacobus N

2016-01-01

Natural products, including those derived from higher plants have, over the years, contributed greatly to the development of modern therapeutic drugs. Due to the medicinal importance in traditional practice and the diversified biology and chemistry of the constituents from Artemisia spp., the genus has been receiving growing attention. The aim of this study was to investigate the ability of the ethanol extract, four fractions (F1-F4) and five compounds namely artemisinin (1), scopoletin (2), chrysosplenetin (3), eupatin (4) and 3-O-β-d-glucopyranoside of sitosterol (5) isolated from A. annua to modulate the activity of anticholinesterase (AchE) and the production of nitric oxide (NO) in LPS-activated RAW 264.7 macrophages. At the lowest concentration tested (6.25 µg/mL), the crude extract and fraction F2 had the highest NO inhibitory activity (72.39 and 71.00 % inhibition respectively) without significant toxicity on the viability of macrophage cells (93.86 and 79.87 % of cell viability respectively). The crude extract inhibited AchE activity by 71.83 % (at 1 mg/mL) with an IC50 value of 87.43 µg/mL while F2 and F4 were the most active fractions (IC50 values of 36.75 and 28.82 µg/mL). Artemisinin (1) and chrysosplenetin (3) had the highest AChE activity with 71.67 and 80.00 % inhibition (at 0.1 mg/mL) and IC50 values of 29.34 and 27.14 µg/mL, respectively. Our results validate the traditional use of A. annua and could help to support the usefulness of this plant in the treatment of inflammatory and neurological disorders especially where nitric oxide and a cholinesterase are involved.

Comparative Proteomic and Nutritional Composition Analysis of Independent Transgenic Pigeon Pea Seeds Harboring cry1AcF and cry2Aa Genes and Their Nontransgenic Counterparts.

PubMed

Mishra, Pragya; Singh, Shweta; Rathinam, Maniraj; Nandiganti, Muralimohan; Ram Kumar, Nikhil; Thangaraj, Arulprakash; Thimmegowda, Vinutha; Krishnan, Veda; Mishra, Vagish; Jain, Neha; Rai, Vandna; Pattanayak, Debasis; Sreevathsa, Rohini

2017-02-22

Safety assessment of genetically modified plants is an important aspect prior to deregulation. Demonstration of substantial equivalence of the transgenics compared to their nontransgenic counterparts can be performed using different techniques at various molecular levels. The present study is a first-ever comprehensive evaluation of pigeon pea transgenics harboring two independent cry genes, cry2Aa and cry1AcF. The absence of unintended effects in the transgenic seed components was demonstrated by proteome and nutritional composition profiling. Analysis revealed that no significant differences were found in the various nutritional compositional analyses performed. Additionally, 2-DGE-based proteome analysis of the transgenic and nontransgenic seed protein revealed that there were no major changes in the protein profile, although a minor fold change in the expression of a few proteins was observed. Furthermore, the study also demonstrated that neither the integration of T-DNA nor the expression of the cry genes resulted in the production of unintended effects in the form of new toxins or allergens.

11 CFR 112.1 - Requests for advisory opinions (2 U.S.C. 437f(a)(1)).

Code of Federal Regulations, 2010 CFR

2010-01-01

... situation, or regarding the activities of third parties, do not qualify as advisory opinion requests. (c... Election Commission, Office of General Counsel, 999 E Street, NW., Washington, DC 20463. (f) Upon receipt...

Targeting the Warburg effect with a novel glucose transporter inhibitor to overcome gemcitabine resistance in pancreatic cancer cells

PubMed Central

Lai, I-Lu; Chou, Chih-Chien; Lai, Po-Ting; Fang, Chun-Sheng; Shirley, Lawrence A.; Yan, Ribai; Mo, Xiaokui; Bloomston, Mark; Kulp, Samuel K.; Bekaii-Saab, Tanios; Chen, Ching-Shih

2014-01-01

Gemcitabine resistance remains a significant clinical challenge. Here, we used a novel glucose transporter (Glut) inhibitor, CG-5, as a proof-of-concept compound to investigate the therapeutic utility of targeting the Warburg effect to overcome gemcitabine resistance in pancreatic cancer. The effects of gemcitabine and/or CG-5 on viability, survival, glucose uptake and DNA damage were evaluated in gemcitabine-sensitive and gemcitabine-resistant pancreatic cancer cell lines. Mechanistic studies were conducted to determine the molecular basis of gemcitabine resistance and the mechanism of CG-5-induced sensitization to gemcitabine. The effects of CG-5 on gemcitabine sensitivity were investigated in a xenograft tumor model of gemcitabine-resistant pancreatic cancer. In contrast to gemcitabine-sensitive pancreatic cancer cells, the resistant Panc-1 and Panc-1GemR cells responded to gemcitabine by increasing the expression of ribonucleotide reductase M2 catalytic subunit (RRM2) through E2F1-mediated transcriptional activation. Acting as a pan-Glut inhibitor, CG-5 abrogated this gemcitabine-induced upregulation of RRM2 through decreased E2F1 expression, thereby enhancing gemcitabine-induced DNA damage and inhibition of cell survival. This CG-5-induced inhibition of E2F1 expression was mediated by the induction of a previously unreported E2F1-targeted microRNA, miR-520f. The addition of oral CG-5 to gemcitabine therapy caused greater suppression of Panc-1GemR xenograft tumor growth in vivo than either drug alone. Glut inhibition may be an effective strategy to enhance gemcitabine activity for the treatment of pancreatic cancer. PMID:24879635

Estimation of crop gross primary production (GPP): fAPAR_chl versus MOD15A2 FPAR

USDA-ARS?s Scientific Manuscript database

Within leaf chloroplasts chlorophylls absorb photosynthetically active radiation (PAR) for photosynthesis (PSN). The MOD15A2 FPAR (fraction of PAR absorbed by canopy, i.e., fAPARcanopy) product has been widely used to compute absorbed PAR for PSN (APARPSN). The MOD17A2 algorithm uses MOD15A2 FPAR i...

Deregulated Methionine Adenosyltransferase α1, c-Myc and Maf Proteins Interplay Promotes Cholangiocarcinoma Growth in Mice and Humans

PubMed Central

Yang, Heping; Liu, Ting; Wang, Jiaohong; Li, Tony W.H.; Fan, Wei; Peng, Hui; Krishnan, Anuradha; Gores, Gregory J.; Mato, Jose M.; Lu, Shelly C.

2016-01-01

We reported c-Myc induction drives cholestatic liver injury and cholangiocarcinoma (CCA) in mice. We also showed induction of Maf proteins (MafG and c-Maf) contributed to cholestatic liver injury, whereas S-adenosylmethionine (SAMe) administration was protective. Here we determined whether there is interplay between c-Myc, Maf proteins and methionine adenosyltransferase α1 (MATα1), which is responsible for SAMe biosynthesis in liver. We used bile duct ligation (BDL) and lithocholic acid (LCA) treatment in mice as chronic cholestasis models, a murine CCA model, human CCA cell lines KMCH and Huh-28, human liver cancer HepG2, and human CCA specimens to study gene and protein expression, protein-protein interactions, molecular mechanisms and functional outcomes. We found c-Myc, MATα1 (encoded by MAT1A), MafG and c-Maf interact with each other directly. MAT1A expression fell in hepatocytes and bile duct epithelial cells during chronic cholestasis and in murine and human CCA. The opposite occurred with c-Myc, MafG and c-Maf expression. MATα1 interacts mainly with Mnt in normal liver but this switches to c-Maf, MafG and c-Myc in cholestatic livers and CCA. Promoter regions of these genes have E-boxes that are bound by MATα1 and Mnt in normal liver and benign bile duct epithelial cells that switched to c-Myc, c-Maf and MafG in cholestasis and CCA cells. E-box positively regulates c-Myc, MafG and c-Maf, but it negatively regulates MAT1A. MATα1 represses whereas c-Myc, MafG and c-Maf enhance E-box-driven promoter activity. Knocking down MAT1A or overexpressing MafG or c-Maf enhanced CCA growth and invasion in vivo. Conclusion We have uncovered a novel interplay between MATα1, c-Myc and Maf proteins and their deregulation during chronic cholestasis may facilitate CCA oncogenesis. PMID:26969892

FMRI activity during associative encoding is correlated with cardiorespiratory fitness and source memory performance in older adults

PubMed Central

Hayes, Scott M.; Hayes, Jasmeet P.; Williams, Victoria J.; Liu, Huiting; Verfaellie, Mieke

2017-01-01

Older adults (OA), relative to young adults (YA), exhibit age-related alterations in functional Magnetic Resonance Imaging (fMRI) activity during associative encoding, which contributes to deficits in source memory. Yet, there are remarkable individual differences in brain health and memory performance among OA. Cardiorespiratory fitness (CRF) is one individual difference factor that may attenuate brain aging, and thereby contribute to enhanced source memory in OA. To examine this possibility, 26 OA and 31 YA completed a treadmill-based exercise test to evaluate CRF (peak VO2) and fMRI to examine brain activation during a face-name associative encoding task. Our results indicated that in OA, peak VO2 was positively associated with fMRI activity during associative encoding in multiple regions including bilateral prefrontal cortex, medial frontal cortex, bilateral thalamus and left hippocampus. Next, a conjunction analysis was conducted to assess whether CRF influenced age-related differences in fMRI activation. We classified OA as high or low CRF and compared their activation to YA. High fit OA (HFOA) showed fMRI activation more similar to YA than low fit OA (LFOA) (i.e., reduced age-related differences) in multiple regions including thalamus, posterior and prefrontal cortex. Conversely, in other regions, primarily in prefrontal cortex, HFOA, but not LFOA, demonstrated greater activation than YA (i.e., increased age-related differences). Further, fMRI activity in these brain regions was positively associated with source memory among OA, with a mediation model demonstrating that associative encoding activation in medial frontal cortex indirectly influenced the relationship between peak VO2 and subsequent source memory performance. These results indicate that CRF may contribute to neuroplasticity among OA, reducing age-related differences in some brain regions, consistent with the brain maintenance hypothesis, but accentuating age-differences in other regions, consistent with the brain compensation hypothesis. PMID:28161031

FMRI activity during associative encoding is correlated with cardiorespiratory fitness and source memory performance in older adults.

PubMed

Hayes, Scott M; Hayes, Jasmeet P; Williams, Victoria J; Liu, Huiting; Verfaellie, Mieke

2017-06-01

Older adults (OA), relative to young adults (YA), exhibit age-related alterations in functional Magnetic Resonance Imaging (fMRI) activity during associative encoding, which contributes to deficits in source memory. Yet, there are remarkable individual differences in brain health and memory performance among OA. Cardiorespiratory fitness (CRF) is one individual difference factor that may attenuate brain aging, and thereby contribute to enhanced source memory in OA. To examine this possibility, 26 OA and 31 YA completed a treadmill-based exercise test to evaluate CRF (peak VO 2 ) and fMRI to examine brain activation during a face-name associative encoding task. Our results indicated that in OA, peak VO 2 was positively associated with fMRI activity during associative encoding in multiple regions including bilateral prefrontal cortex, medial frontal cortex, bilateral thalamus and left hippocampus. Next, a conjunction analysis was conducted to assess whether CRF influenced age-related differences in fMRI activation. We classified OA as high or low CRF and compared their activation to YA. High fit OA (HFOA) showed fMRI activation more similar to YA than low fit OA (LFOA) (i.e., reduced age-related differences) in multiple regions including thalamus, posterior and prefrontal cortex. Conversely, in other regions, primarily in prefrontal cortex, HFOA, but not LFOA, demonstrated greater activation than YA (i.e., increased age-related differences). Further, fMRI activity in these brain regions was positively associated with source memory among OA, with a mediation model demonstrating that associative encoding activation in medial frontal cortex indirectly influenced the relationship between peak VO 2 and subsequent source memory performance. These results indicate that CRF may contribute to neuroplasticity among OA, reducing age-related differences in some brain regions, consistent with the brain maintenance hypothesis, but accentuating age-differences in other regions, consistent with the brain compensation hypothesis. Published by Elsevier Ltd.

Bim, a Proapoptotic Protein, Up-regulated via Transcription Factor E2F1-dependent Mechanism, Functions as a Prosurvival Molecule in Cancer*

PubMed Central

Gogada, Raghu; Yadav, Neelu; Liu, Junwei; Tang, Shaohua; Zhang, Dianmu; Schneider, Andrea; Seshadri, Athul; Sun, Leimin; Aldaz, C. Marcelo; Tang, Dean G.; Chandra, Dhyan

2013-01-01

Proapoptotic Bcl-2 homology 3-only protein Bim plays an important role in Bax/Bak-mediated cytochrome c release and apoptosis. Here, we provide evidence for a novel prosurvival function of Bim in cancer cells. Bim was constitutively overexpressed in multiple prostate and breast cancer cells as well as in primary tumor cells. Quantitative real time PCR analysis showed that Bim was transcriptionally up-regulated. We have identified eight endogenous E2F1-binding sites on the Bim promoter using in silico analysis. Luciferase assay demonstrated that Bim expression was E2F1-dependent as mutation of the E2F1-binding sites on the Bim promoter inhibited luciferase activities. In support, E2F1 silencing led to the loss of Bim expression in cancer cells. Bim primarily localized to mitochondrial and cytoskeleton-associated fractions. Bim silencing or microinjection of anti-Bim antibodies into the cell cytoplasm resulted in cell rounding, detachment, and subsequent apoptosis. We observed up-regulation of prosurvival proteins Bcl-xL and Mcl-1, which sequester Bim in cancer cells. In addition, a phosphorylated form of Bim was also elevated in cancer cells. These findings suggest that the constitutively overexpressed Bim may function as a prosurvival molecule in epithelial cancer cells, and phosphorylation and association with Bcl-xL/Mcl-1 block its proapoptotic functions. PMID:23152504

Interaction of the Retinoblastoma Protein with Orc1 and Its Recruitment to Human Origins of DNA Replication

PubMed Central

Mendoza-Maldonado, Ramiro; Paolinelli, Roberta; Galbiati, Laura; Giadrossi, Sara; Giacca, Mauro

2010-01-01

Background The retinoblastoma protein (Rb) is a crucial regulator of cell cycle progression by binding with E2F transcription factor and repressing the expression of a variety of genes required for the G1-S phase transition. Methodology/Principal Findings Here we show that Rb and E2F1 directly participate in the control of initiation of DNA replication in human HeLa, U2OS and T98G cells by specifically binding to origins of DNA replication in a cell cycle regulated manner. We show that, both in vitro and inside the cells, the largest subunit of the origin recognition complex (Orc1) specifically binds hypo-phosphorylated Rb and that this interaction is competitive with the binding of Rb to E2F1. The displacement of Rb-bound Orc1 by E2F1 at origins of DNA replication marks the progression of the G1 phase of the cell cycle toward the G1-S border. Conclusions/Significance The participation of Rb and E2F1 in the formation of the multiprotein complex that binds origins of DNA replication in mammalian cells appears to represent an effective mechanism to couple the expression of genes required for cell cycle progression to the activation of DNA replication. PMID:21085491

A systems biology approach for miRNA-mRNA expression patterns analysis in non-small cell lung cancer.

PubMed

Najafi, Ali; Tavallaei, Mahmood; Hosseini, Sayed Mostafa

2016-01-01

Non-small cell lung cancers (NSCLCs) is a prevalent and heterogeneous subtype of lung cancer accounting for 85 percent of patients. MicroRNAs (miRNAs), a class of small endogenous non-coding RNAs, incorporate into regulation of gene expression post-transcriptionally. Therefore, deregulation of miRNAs' expression has provided further layers of complexity to the molecular etiology and pathogenesis of different diseases and malignancies. Although, until now considerable number of studies has been carried out to illuminate this complexity in NSCLC, they have remained less effective in their goal due to lack of a holistic and integrative systems biology approach which considers all natural elaborations of miRNAs' function. It is able to reliably nominate most affected signaling pathways and therapeutic target genes by deregulated miRNAs during a particular pathological condition. Herein, we utilized a holistic systems biology approach, based on appropriate re-analyses of microarray datasets followed by reliable data filtering, to analyze integrative and combinatorial deregulated miRNA-mRNA interaction network in NSCLC, aiming to ascertain miRNA-dysregulated signaling pathway and potential therapeutic miRNAs and mRNAs which represent a lion' share during various aspects of NSCLC's pathogenesis. Our systems biology approach introduced and nominated 1) important deregulated miRNAs in NSCLCs compared with normal tissue 2) significant and confident deregulated mRNAs which were anti-correlatively targeted by deregulated miRNA in NSCLCs and 3) dysregulated signaling pathways in association with deregulated miRNA-mRNAs interactions in NSCLCs. These results introduce possible mechanism of function of deregulated miRNAs and mRNAs in NSCLC that could be used as potential therapeutic targets.

Absence of the neurogenesis-dependent nuclear receptor TLX induces inflammation in the hippocampus.

PubMed

Kozareva, Danka A; Hueston, Cara M; Ó'Léime, Ciarán S; Crotty, Suzanne; Dockery, Peter; Cryan, John F; Nolan, Yvonne M

2017-08-20

The orphan nuclear receptor TLX (Nr2e1) is a key regulator of hippocampal neurogenesis. Impaired adult hippocampal neurogenesis has been reported in neurodegenerative and psychiatric conditions including dementia and stress-related depression. Neuroinflammation is also implicated in the neuropathology of these disorders, and has been shown to negatively affect hippocampal neurogenesis. To investigate a role for TLX in hippocampal neuroinflammation, we assessed microglial activation in the hippocampus of mice with a spontaneous deletion of TLX. Results from our study suggest that a lack of TLX is implicated in deregulation of microglial phenotype and that consequently, the survival and function of newborn cells in the hippocampus is impaired. TLX may be an important target in understanding inflammatory-associated impairments in neurogenesis. Copyright © 2017 Elsevier B.V. All rights reserved.

The effect of airline deregulation on automobile fatalities.

PubMed

Bylow, L F; Savage, I

1991-10-01

This paper attempts to quantify the effects of airline deregulation in the United States on intercity automobile travel and consequently on the number of highway fatalities. A demand model is constructed for auto travel, which includes variables representing the price and availability of air service. A reduced form model of the airline market is then estimated. Finding that deregulation has decreased airfares and increased flights, it is estimated that auto travel has been reduced by 2.2% per year on average. Given assumptions on the characteristics of drivers switching modes and the types of roads they drove on, the number of automobile fatalities averted since 1978 is estimated to be in the range 200-300 per year.

Dynamic NF-κB and E2F interactions control the priority and timing of inflammatory signalling and cell proliferation

PubMed Central

Ankers, John M; Awais, Raheela; Jones, Nicholas A; Boyd, James; Ryan, Sheila; Adamson, Antony D; Harper, Claire V; Bridge, Lloyd; Spiller, David G; Jackson, Dean A; Paszek, Pawel; Sée, Violaine; White, Michael RH

2016-01-01

Dynamic cellular systems reprogram gene expression to ensure appropriate cellular fate responses to specific extracellular cues. Here we demonstrate that the dynamics of Nuclear Factor kappa B (NF-κB) signalling and the cell cycle are prioritised differently depending on the timing of an inflammatory signal. Using iterative experimental and computational analyses, we show physical and functional interactions between NF-κB and the E2 Factor 1 (E2F-1) and E2 Factor 4 (E2F-4) cell cycle regulators. These interactions modulate the NF-κB response. In S-phase, the NF-κB response was delayed or repressed, while cell cycle progression was unimpeded. By contrast, activation of NF-κB at the G1/S boundary resulted in a longer cell cycle and more synchronous initial NF-κB responses between cells. These data identify new mechanisms by which the cellular response to stress is differentially controlled at different stages of the cell cycle. DOI: http://dx.doi.org/10.7554/eLife.10473.001 PMID:27185527

(2E,5E)-2,5-Bis(3-hydroxy-4-methoxybenzylidene) cyclopentanone Exerts Anti-Melanogenesis and Anti-Wrinkle Activities in B16F10 Melanoma and Hs27 Fibroblast Cells.

PubMed

Jung, Hee Jin; Lee, A Kyoung; Park, Yeo Jin; Lee, Sanggwon; Kang, Dongwan; Jung, Young Suk; Chung, Hae Young; Moon, Hyung Ryong

2018-06-11

Ultraviolet (UV) radiation exposure is the primary cause of extrinsic skin aging, which results in skin hyperpigmentation and wrinkling. In this study, we investigated the whitening effect of (2 E ,5 E )-2,5-bis(3-hydroxy-4-methoxybenzylidene)cyclopentanone (BHCP) on B16F10 melanoma and its anti-wrinkle activity on Hs27 fibroblasts cells. BHCP was found to potently inhibit tyrosinase, with 50% inhibition concentration (IC 50 ) values of 1.10 µM and 8.18 µM for monophenolase (l-tyrosine) and diphenolase (l-DOPA), and the enzyme kinetics study revealed that BHCP is a competitive-type tyrosinase inhibitor. Furthermore, BHCP significantly inhibited melanin content and cellular tyrosinase activity, and downregulated the levels of microphthalmia-associated transcription factor (MITF), phosphorylated levels of cAMP response element-binding (CREB) protein, and tyrosinase in α-melanocyte stimulating hormone (α-MSH)-induced B16F10 melanoma cells. Moreover, BHCP inhibited the phosphorylation of p65 and expression of matrix metalloproteinases (MMP-1, MMP-9, MMP-12, and MMP-13) in Hs27 fibroblasts stimulated with UV radiation. Therefore, our results demonstrate that BHCP may be a good candidate for the development of therapeutic agents for diseases associated with hyperpigmentation and wrinkling.

The ER-bound RING finger protein 5 (RNF5/RMA1) causes degenerative myopathy in transgenic mice and is deregulated in inclusion body myositis.

PubMed

Delaunay, Agnès; Bromberg, Kenneth D; Hayashi, Yukiko; Mirabella, Massimiliano; Burch, Denise; Kirkwood, Brian; Serra, Carlo; Malicdan, May C; Mizisin, Andrew P; Morosetti, Roberta; Broccolini, Aldobrando; Guo, Ling T; Jones, Stephen N; Lira, Sergio A; Puri, Pier Lorenzo; Shelton, G Diane; Ronai, Ze'ev

2008-02-13

Growing evidence supports the importance of ubiquitin ligases in the pathogenesis of muscular disorders, although underlying mechanisms remain largely elusive. Here we show that the expression of RNF5 (aka RMA1), an ER-anchored RING finger E3 ligase implicated in muscle organization and in recognition and processing of malfolded proteins, is elevated and mislocalized to cytoplasmic aggregates in biopsies from patients suffering from sporadic-Inclusion Body Myositis (sIBM). Consistent with these findings, an animal model for hereditary IBM (hIBM), but not their control littermates, revealed deregulated expression of RNF5. Further studies for the role of RNF5 in the pathogenesis of s-IBM and more generally in muscle physiology were performed using RNF5 transgenic and KO animals. Transgenic mice carrying inducible expression of RNF5, under control of beta-actin or muscle specific promoter, exhibit an early onset of muscle wasting, muscle degeneration and extensive fiber regeneration. Prolonged expression of RNF5 in the muscle also results in the formation of fibers containing congophilic material, blue-rimmed vacuoles and inclusion bodies. These phenotypes were associated with altered expression and activity of ER chaperones, characteristic of myodegenerative diseases such as s-IBM. Conversely, muscle regeneration and induction of ER stress markers were delayed in RNF5 KO mice subjected to cardiotoxin treatment. While supporting a role for RNF5 Tg mice as model for s-IBM, our study also establishes the importance of RNF5 in muscle physiology and its deregulation in ER stress associated muscular disorders.

The ER-Bound RING Finger Protein 5 (RNF5/RMA1) Causes Degenerative Myopathy in Transgenic Mice and Is Deregulated in Inclusion Body Myositis

PubMed Central

Delaunay, Agnès; Bromberg, Kenneth D.; Hayashi, Yukiko; Mirabella, Massimiliano; Burch, Denise; Kirkwood, Brian; Serra, Carlo; Malicdan, May C.; Mizisin, Andrew P.; Morosetti, Roberta; Broccolini, Aldobrando; Guo, Ling T.; Jones, Stephen N.; Lira, Sergio A.; Puri, Pier Lorenzo; Shelton, G. Diane; Ronai, Ze'ev

2008-01-01

Growing evidence supports the importance of ubiquitin ligases in the pathogenesis of muscular disorders, although underlying mechanisms remain largely elusive. Here we show that the expression of RNF5 (aka RMA1), an ER-anchored RING finger E3 ligase implicated in muscle organization and in recognition and processing of malfolded proteins, is elevated and mislocalized to cytoplasmic aggregates in biopsies from patients suffering from sporadic-Inclusion Body Myositis (sIBM). Consistent with these findings, an animal model for hereditary IBM (hIBM), but not their control littermates, revealed deregulated expression of RNF5. Further studies for the role of RNF5 in the pathogenesis of s-IBM and more generally in muscle physiology were performed using RNF5 transgenic and KO animals. Transgenic mice carrying inducible expression of RNF5, under control of β-actin or muscle specific promoter, exhibit an early onset of muscle wasting, muscle degeneration and extensive fiber regeneration. Prolonged expression of RNF5 in the muscle also results in the formation of fibers containing congophilic material, blue-rimmed vacuoles and inclusion bodies. These phenotypes were associated with altered expression and activity of ER chaperones, characteristic of myodegenerative diseases such as s-IBM. Conversely, muscle regeneration and induction of ER stress markers were delayed in RNF5 KO mice subjected to cardiotoxin treatment. While supporting a role for RNF5 Tg mice as model for s-IBM, our study also establishes the importance of RNF5 in muscle physiology and its deregulation in ER stress associated muscular disorders. PMID:18270596

Integrative Genomics Reveals Mechanisms of Copy Number Alterations Responsible for Transcriptional Deregulation in Colorectal Cancer

PubMed Central

Camps, Jordi; Nguyen, Quang Tri; Padilla-Nash, Hesed M.; Knutsen, Turid; McNeil, Nicole E.; Wangsa, Danny; Hummon, Amanda B.; Grade, Marian; Ried, Thomas; Difilippantonio, Michael J.

2016-01-01

To evaluate the mechanisms and consequences of chromosomal aberrations in colorectal cancer (CRC), we used a combination of spectral karyotyping, array comparative genomic hybridization (aCGH), and array-based global gene expression profiling on 31 primary carcinomas and 15 established cell lines. Importantly, aCGH showed that the genomic profiles of primary tumors are recapitulated in the cell lines. We revealed a preponderance of chromosome breakpoints at sites of copy number variants (CNVs) in the CRC cell lines, a novel mechanism of DNA breakage in cancer. The integration of gene expression and aCGH led to the identification of 157 genes localized within high-level copy number changes whose transcriptional deregulation was significantly affected across all of the samples, thereby suggesting that these genes play a functional role in CRC. Genomic amplification at 8q24 was the most recurrent event and led to the overexpression of MYC and FAM84B. Copy number dependent gene expression resulted in deregulation of known cancer genes such as APC, FGFR2, and ERBB2. The identification of only 36 genes whose localization near a breakpoint could account for their observed deregulated expression demonstrates that the major mechanism for transcriptional deregulation in CRC is genomic copy number changes resulting from chromosomal aberrations. PMID:19691111

Biochemical characterisation of the chlamydial MurF ligase, and possible sequence of the chlamydial peptidoglycan pentapeptide stem.

PubMed

Patin, Delphine; Bostock, Julieanne; Chopra, Ian; Mengin-Lecreulx, Dominique; Blanot, Didier

2012-06-01

Chlamydiaceae are obligate intracellular bacteria that do not synthesise detectable peptidoglycan although they possess an almost complete arsenal of genes encoding peptidoglycan biosynthetic activities. In this paper, the murF gene from Chlamydia trachomatis was shown to be capable of complementing a conditional Escherichia coli mutant impaired in UDP-MurNAc-tripeptide:D-Ala-D-Ala ligase activity. Recombinant MurF from C. trachomatis was overproduced and purified from E. coli. It exhibited ATP-dependent UDP-MurNAc-X-γ-D-Glu-meso-A(2)pm:D-Ala-D-Ala ligase activity in vitro. No significant difference of kinetic parameters was seen when X was L-Ala, L-Ser or Gly. The L-Lys-containing UDP-MurNAc-tripeptide was a poorer substrate as compared to the meso-A(2)pm-containing one. Based on the respective substrate specificities of the chlamydial MurC, MurE, MurF and Ddl enzymes, a sequence L-Ala/L-Ser/Gly-γ-D-Glu-meso-A(2)pm-D-Ala-D-Ala is expected for the chlamydial pentapeptide stem, with Gly at position 1 being less likely.

Prostate Cancer Evaluation: Design, Synthesis and Evaluation of Novel Enzyme-Activated Proton MRI Contrast Agents

DTIC Science & Technology

2008-10-01

3$*(6 D1$0(2)5(63216,%/(3(5621 D5(3257 E $%675$&7 F7+,63$*( /,0,7$7,212) $%675$&7 6WDQGDUG)RUP 5HY 3UHVFULEHG... E \\$16,6WG= 7KHSXEOLFUHSRUWLQJEXUGHQIRUWKLVFROOHFWLRQRI LQIRUPDWLRQLVHVWLPDWHGWRDYHUDJHKRXUSHUUHVSRQVH LQFOXGLQJWKHWLPH...FRQWUROQXPEHU 3/($6(�(7851)250727+($%29($’𔃿(66 ’$7(6&29(5(’ )URP7R E *5$17180%(5 F352*5$0(/(0(17180%(5 G

MYBL2 (B-Myb): a central regulator of cell proliferation, cell survival and differentiation involved in tumorigenesis

PubMed Central

Musa, Julian; Aynaud, Marie-Ming; Mirabeau, Olivier; Delattre, Olivier; Grünewald, Thomas GP

2017-01-01

Limitless cell proliferation, evasion from apoptosis, dedifferentiation, metastatic spread and therapy resistance: all these properties of a cancer cell contribute to its malignant phenotype and affect patient outcome. MYBL2 (alias B-Myb) is a transcription factor of the MYB transcription factor family and a physiological regulator of cell cycle progression, cell survival and cell differentiation. When deregulated in cancer cells, MYBL2 mediates the deregulation of these properties. In fact, MYBL2 is overexpressed and associated with poor patient outcome in numerous cancer entities. MYBL2 and players of its downstream transcriptional network can be used as prognostic and/or predictive biomarkers as well as potential therapeutic targets to offer less toxic and more specific anti-cancer therapies in future. In this review, we summarize current knowledge on the physiological roles of MYBL2 and highlight the impact of its deregulation on cancer initiation and progression. PMID:28640249

BID-F1 and BID-F2 Domains of Bartonella henselae Effector Protein BepF Trigger Together with BepC the Formation of Invasome Structures

PubMed Central

Truttmann, Matthias C.; Guye, Patrick; Dehio, Christoph

2011-01-01

The gram-negative, zoonotic pathogen Bartonella henselae (Bhe) translocates seven distinct Bartonella effector proteins (Beps) via the VirB/VirD4 type IV secretion system (T4SS) into human cells, thereby interfering with host cell signaling [1], [2]. In particular, the effector protein BepG alone or the combination of effector proteins BepC and BepF trigger massive F-actin rearrangements that lead to the establishment of invasome structures eventually resulting in the internalization of entire Bhe aggregates [2], [3]. In this report, we investigate the molecular function of the effector protein BepF in the eukaryotic host cell. We show that the N-terminal [E/T]PLYAT tyrosine phosphorylation motifs of BepF get phosphorylated upon translocation but do not contribute to invasome-mediated Bhe uptake. In contrast, we found that two of the three BID domains of BepF are capable to trigger invasome formation together with BepC, while a mutation of the WxxxE motif of the BID-F1 domain inhibited its ability to contribute to the formation of invasome structures. Next, we show that BepF function during invasome formation can be replaced by the over-expression of constitutive-active Rho GTPases Rac1 or Cdc42. Finally we demonstrate that BID-F1 and BID-F2 domains promote the formation of filopodia-like extensions in NIH 3T3 and HeLa cells as well as membrane protrusions in HeLa cells, suggesting a role for BepF in Rac1 and Cdc42 activation during the process of invasome formation. PMID:22043280

BID-F1 and BID-F2 domains of Bartonella henselae effector protein BepF trigger together with BepC the formation of invasome structures.

PubMed

Truttmann, Matthias C; Guye, Patrick; Dehio, Christoph

2011-01-01

The gram-negative, zoonotic pathogen Bartonella henselae (Bhe) translocates seven distinct Bartonella effector proteins (Beps) via the VirB/VirD4 type IV secretion system (T4SS) into human cells, thereby interfering with host cell signaling [1], [2]. In particular, the effector protein BepG alone or the combination of effector proteins BepC and BepF trigger massive F-actin rearrangements that lead to the establishment of invasome structures eventually resulting in the internalization of entire Bhe aggregates [2], [3]. In this report, we investigate the molecular function of the effector protein BepF in the eukaryotic host cell. We show that the N-terminal [E/T]PLYAT tyrosine phosphorylation motifs of BepF get phosphorylated upon translocation but do not contribute to invasome-mediated Bhe uptake. In contrast, we found that two of the three BID domains of BepF are capable to trigger invasome formation together with BepC, while a mutation of the WxxxE motif of the BID-F1 domain inhibited its ability to contribute to the formation of invasome structures. Next, we show that BepF function during invasome formation can be replaced by the over-expression of constitutive-active Rho GTPases Rac1 or Cdc42. Finally we demonstrate that BID-F1 and BID-F2 domains promote the formation of filopodia-like extensions in NIH 3T3 and HeLa cells as well as membrane protrusions in HeLa cells, suggesting a role for BepF in Rac1 and Cdc42 activation during the process of invasome formation.

Revisiting the Measurement of Anomie

PubMed Central

Teymoori, Ali; Jetten, Jolanda; Bastian, Brock; Ariyanto, Amarina; Autin, Frédérique; Ayub, Nadia; Badea, Constantina; Besta, Tomasz; Butera, Fabrizio; Costa-Lopes, Rui; Cui, Lijuan; Fantini, Carole; Finchilescu, Gillian; Gaertner, Lowell; Gollwitzer, Mario; Gómez, Ángel; González, Roberto; Hong, Ying Yi; Jensen, Dorthe Høj; Karasawa, Minoru; Kessler, Thomas; Klein, Olivier; Lima, Marcus; Mähönen, Tuuli Anna; Megevand, Laura; Morton, Thomas; Paladino, Paola; Polya, Tibor; Ruza, Aleksejs; Shahrazad, Wan; Sharma, Sushama; Torres, Ana Raquel; van der Bles, Anne Marthe; Wohl, Michael

2016-01-01

Sociologists coined the term “anomie” to describe societies that are characterized by disintegration and deregulation. Extending beyond conceptualizations of anomie that conflate the measurements of anomie as ‘a state of society’ and as a ‘state of mind’, we disentangle these conceptualizations and develop an analysis and measure of this phenomenon focusing on anomie as a perception of the ‘state of society’. We propose that anomie encompasses two dimensions: a perceived breakdown in social fabric (i.e., disintegration as lack of trust and erosion of moral standards) and a perceived breakdown in leadership (i.e., deregulation as lack of legitimacy and effectiveness of leadership). Across six studies we present evidence for the validity of the new measure, the Perception of Anomie Scale (PAS). Studies 1a and 1b provide evidence for the proposed factor structure and internal consistency of PAS. Studies 2a-c provide evidence of convergent and discriminant validity. Finally, assessing PAS in 28 countries, we show that PAS correlates with national indicators of societal functioning and that PAS predicts national identification and well-being (Studies 3a & 3b). The broader implications of the anomie construct for the study of group processes are discussed. PMID:27383133

Revisiting the Measurement of Anomie.

PubMed

Teymoori, Ali; Jetten, Jolanda; Bastian, Brock; Ariyanto, Amarina; Autin, Frédérique; Ayub, Nadia; Badea, Constantina; Besta, Tomasz; Butera, Fabrizio; Costa-Lopes, Rui; Cui, Lijuan; Fantini, Carole; Finchilescu, Gillian; Gaertner, Lowell; Gollwitzer, Mario; Gómez, Ángel; González, Roberto; Hong, Ying Yi; Jensen, Dorthe Høj; Karasawa, Minoru; Kessler, Thomas; Klein, Olivier; Lima, Marcus; Mähönen, Tuuli Anna; Megevand, Laura; Morton, Thomas; Paladino, Paola; Polya, Tibor; Ruza, Aleksejs; Shahrazad, Wan; Sharma, Sushama; Torres, Ana Raquel; van der Bles, Anne Marthe; Wohl, Michael

2016-01-01

Sociologists coined the term "anomie" to describe societies that are characterized by disintegration and deregulation. Extending beyond conceptualizations of anomie that conflate the measurements of anomie as 'a state of society' and as a 'state of mind', we disentangle these conceptualizations and develop an analysis and measure of this phenomenon focusing on anomie as a perception of the 'state of society'. We propose that anomie encompasses two dimensions: a perceived breakdown in social fabric (i.e., disintegration as lack of trust and erosion of moral standards) and a perceived breakdown in leadership (i.e., deregulation as lack of legitimacy and effectiveness of leadership). Across six studies we present evidence for the validity of the new measure, the Perception of Anomie Scale (PAS). Studies 1a and 1b provide evidence for the proposed factor structure and internal consistency of PAS. Studies 2a-c provide evidence of convergent and discriminant validity. Finally, assessing PAS in 28 countries, we show that PAS correlates with national indicators of societal functioning and that PAS predicts national identification and well-being (Studies 3a & 3b). The broader implications of the anomie construct for the study of group processes are discussed.

The PPARα/p16INK4a Pathway inhibits Vascular Smooth Muscle Cell Proliferation by repressing Cell Cycle-dependent Telomerase Activation

PubMed Central

Gizard, Florence; Nomiyama, Takashi; Zhao, Yue; Findeisen, Hannes M.; Heywood, Elizabeth B.; Jones, Karrie L.; Staels, Bart; Bruemmer, Dennis

2009-01-01

Peroxisome Proliferator-Activated Receptor (PPAR) α, the molecular target for fibrates used to treat dyslipidemia, exerts pleiotropic effects on vascular cells. In vascular smooth muscle cells (VSMCs), we have previously demonstrated that PPARα activation suppresses G1→S cell cycle progression by targeting the cyclin-dependent kinase inhibitor p16INK4a (p16). In the present study, we demonstrate that this inhibition of VSMC proliferation by PPARα is mediated through a p16-dependent suppression of telomerase activity, which has been implicated in key cellular functions including proliferation. PPARα activation inhibited mitogen-induced telomerase activity by repressing the catalytic subunit telomerase reverse transcriptase (TERT) through negative cross-talk with an E2F-1-dependent trans-activation of the TERT promoter. This trans-repression involved the recruitment of the retinoblastoma (RB) family proteins p107 and p130 to the TERT promoter resulting in impaired E2F-1 binding, an effect which was dependent on p16. The inhibition of cell proliferation by PPARα activation was lost in VSMC following TERT overexpression or knock-down, pointing to a key role of telomerase as a target for the antiproliferative effects of PPARα. Finally, we demonstrate that PPARα agonists suppress telomerase activation during the proliferative response following vascular injury indicating that these findings are applicable in vivo. In concert, these results demonstrate that the anti-proliferative effects of PPARα in VSMCs depend on the suppression of telomerase activity by targeting the p16/RB/E2F transcriptional cascade. PMID:18818403

Spectroscopic characterization, antimicrobial activity and molecular docking study of novel azo-imine functionalized sulphamethoxazoles

NASA Astrophysics Data System (ADS)

Sahu, Nilima; Mondal, Sudipa; Naskar, Kaushik; Mahapatra, Ananya Das; Gupta, Suvroma; Slawin, Alexandra M. Z.; Chattopadhyay, Debprasad; Sinha, Chittaranjan

2018-03-01

[SMXsbnd Ndbnd Nsbnd C6H3sbnd (p-OH)(msbnd CHO)] (1) reacts with ArNH2 to synthesize Schiff bases, [SMXsbnd Ndbnd Nsbnd C6H3sbnd (psbnd OH)(msbnd HCdbnd Nsbnd Ar)] (Ar = sbnd C6H5 (2a), sbnd C6H4sbnd psbnd CH3 (2b), sbnd C6H4sbnd psbnd OCH3 (2c), sbnd C6H4sbnd psbnd Cl (2d), sbnd C6H4sbnd psbnd NO2 (2e), sbnd C10H7 (2f)) and the products have been assessed for antibacterial properties against Gram positive bacteria, B. subtillis: IC50 (μg/ml): 39.2 (1), 60.1 (2a), 64.0 (2b), 85.6 (2c), 55.1 (2d), 88.4 (2e) and 65.1 (2f); and Gram negative bacteria, E. coli: IC50 (μg/ml): 159.0 (1), 151.4 (2a), 155.3 (2b), 140 (2c), 156.0 (2d), 153.5 (2e) and 157 (2f). The cell line toxicity (Vero cells) has also been evaluated with these compounds and EC50 (μg/ml) values are 129.9 (1), 74.2 (2a) and 93.0 (2b), 191.9 (2c), 99.1 (2d), 93.2 (2e) and 62.0 (2f). The anti-viral efficiency against harpies virus (HSVsbnd 1F ATCC-733) infection demonstrates that the compound 1 has highest selectivity index (CC50/EC50), 5.06 than the compounds 2a-f (CC50/EC50: 1.18 (2a), 1.42 (2b), 3.50 (2c), 1.45 (2d), 1.58 (2e), 1.29 (2f)). The compounds have been spectroscopically characterized and the structural confirmation has been established in one case by single crystal X-ray diffraction studies of 2c. In silico Molecular Docking study has been done using optimized geometries of the compounds to search the most favored binding mode of these drugs and hence useful to explain their competitive drug efficiency.

Correlation between the conformational states of F1-ATPase as determined from its crystal structure and single-molecule rotation

PubMed Central

Okuno, Daichi; Fujisawa, Ryo; Iino, Ryota; Hirono-Hara, Yoko; Imamura, Hiromi; Noji, Hiroyuki

2008-01-01

F1-ATPase is a rotary molecular motor driven by ATP hydrolysis that rotates the γ-subunit against the α3β3 ring. The crystal structures of F1, which provide the structural basis for the catalysis mechanism, have shown essentially 1 stable conformational state. In contrast, single-molecule studies have revealed that F1 has 2 stable conformational states: ATP-binding dwell state and catalytic dwell state. Although structural and single-molecule studies are crucial for the understanding of the molecular mechanism of F1, it remains unclear as to which catalytic state the crystal structure represents. To address this issue, we introduced cysteine residues at βE391 and γR84 of F1 from thermophilic Bacillus PS3. In the crystal structures of the mitochondrial F1, the corresponding residues in the ADP-bound β (βDP) and γ were in direct contact. The βE190D mutation was additionally introduced into the β to slow ATP hydrolysis. By incorporating a single copy of the mutant β-subunit, the chimera F1, α3β2β(E190D/E391C)γ(R84C), was prepared. In single-molecule rotation assay, chimera F1 showed a catalytic dwell pause in every turn because of the slowed ATP hydrolysis of β(E190D/E391C). When the mutant β and γ were cross-linked through a disulfide bond between βE391C and γR84C, F1 paused the rotation at the catalytic dwell angle of β(E190D/E391C), indicating that the crystal structure represents the catalytic dwell state and that βDP is the catalytically active form. The former point was again confirmed in experiments where F1 rotation was inhibited by adenosine-5′-(β,γ-imino)-triphosphate and/or azide, the most commonly used inhibitors for the crystallization of F1. PMID:19075235

Epigenetic Heterogeneity of B-Cell Lymphoma: Chromatin Modifiers

PubMed Central

Hopp, Lydia; Nersisyan, Lilit; Löffler-Wirth, Henry; Arakelyan, Arsen; Binder, Hans

2015-01-01

We systematically studied the expression of more than fifty histone and DNA (de)methylating enzymes in lymphoma and healthy controls. As a main result, we found that the expression levels of nearly all enzymes become markedly disturbed in lymphoma, suggesting deregulation of large parts of the epigenetic machinery. We discuss the effect of DNA promoter methylation and of transcriptional activity in the context of mutated epigenetic modifiers such as EZH2 and MLL2. As another mechanism, we studied the coupling between the energy metabolism and epigenetics via metabolites that act as cofactors of JmjC-type demethylases. Our study results suggest that Burkitt’s lymphoma and diffuse large B-cell Lymphoma differ by an imbalance of repressive and poised promoters, which is governed predominantly by the activity of methyltransferases and the underrepresentation of demethylases in this regulation. The data further suggest that coupling of epigenetics with the energy metabolism can also be an important factor in lymphomagenesis in the absence of direct mutations of genes in metabolic pathways. Understanding of epigenetic deregulation in lymphoma and possibly in cancers in general must go beyond simple schemes using only a few modes of regulation. PMID:26506391

Potential therapeutic effect of nanobased formulation of rivastigmine on rat model of Alzheimer's disease.

PubMed

Ismail, Manal Fouad; Elmeshad, Aliaa Nabil; Salem, Neveen Abdel-Hameed

2013-01-01

To sustain the effect of rivastigmine, a hydrophilic cholinesterase inhibitor, nanobased formulations were prepared. The efficacy of the prepared rivastigmine liposomes (RLs) in comparison to rivastigmine solution (RS) was assessed in an aluminium chloride (AlCl(3))-induced Alzheimer's model. Liposomes were prepared by lipid hydration (F1) and heating (F2) methods. Rats were treated with either RS or RLs (1 mg/kg/day) concomitantly with AlCl(3) (50 mg/kg/day). The study showed that the F1 method produced smaller liposomes (67.51 ± 14.2 nm) than F2 (528.7 ± 15.5 nm), but both entrapped the same amount of the drug (92.1% ± 1.4%). After 6 hours, 74.2% ± 1.5% and 60.8% ± 2.3% of rivastigmine were released from F1 and F2, respectively. Both RLs and RS improved the deterioration of spatial memory induced by AlCl(3), with RLs having a superior effect. Further biochemical measurements proved that RS and RLs were able to lower plasma C-reactive protein, homocysteine and asymmetric dimethy-larginine levels. RS significantly attenuated acetylcholinesterase (AChE) activity, whereas Na(+)/K(+)-adenosine triphosphatase (ATPase) activity was enhanced compared to the AlCl(3)-treated animals; however, RLs succeeded in normalization of AChE and Na(+)/K(+) ATPase activities. Gene-expression profile showed that cotreatment with RS to AlCl(3)-treated rats succeeded in exerting significant decreases in BACE1, AChE, and IL1B gene expression. Normalization of the expression of the aforementioned genes was achieved by coadministration of RLs to AlCl(3)-treated rats. The profound therapeutic effect of RLs over RS was evidenced by nearly preventing amyloid plaque formation, as shown in the histopathological examination of rat brain. RLs could be a potential drug-delivery system for ameliorating Alzheimer's disease.

Potential therapeutic effect of nanobased formulation of rivastigmine on rat model of Alzheimer’s disease

PubMed Central

Ismail, Manal Fouad; ElMeshad, Aliaa Nabil; Salem, Neveen Abdel-Hameed

2013-01-01

Background To sustain the effect of rivastigmine, a hydrophilic cholinesterase inhibitor, nanobased formulations were prepared. The efficacy of the prepared rivastigmine liposomes (RLs) in comparison to rivastigmine solution (RS) was assessed in an aluminium chloride (AlCl3)-induced Alzheimer’s model. Methods Liposomes were prepared by lipid hydration (F1) and heating (F2) methods. Rats were treated with either RS or RLs (1 mg/kg/day) concomitantly with AlCl3 (50 mg/kg/day). Results The study showed that the F1 method produced smaller liposomes (67.51 ± 14.2 nm) than F2 (528.7 ± 15.5 nm), but both entrapped the same amount of the drug (92.1% ± 1.4%). After 6 hours, 74.2% ± 1.5% and 60.8% ± 2.3% of rivastigmine were released from F1 and F2, respectively. Both RLs and RS improved the deterioration of spatial memory induced by AlCl3, with RLs having a superior effect. Further biochemical measurements proved that RS and RLs were able to lower plasma C-reactive protein, homocysteine and asymmetric dimethy-larginine levels. RS significantly attenuated acetylcholinesterase (AChE) activity, whereas Na+/K+-adenosine triphosphatase (ATPase) activity was enhanced compared to the AlCl3-treated animals; however, RLs succeeded in normalization of AChE and Na+/K+ ATPase activities. Gene-expression profile showed that cotreatment with RS to AlCl3-treated rats succeeded in exerting significant decreases in BACE1, AChE, and IL1B gene expression. Normalization of the expression of the aforementioned genes was achieved by coadministration of RLs to AlCl3-treated rats. The profound therapeutic effect of RLs over RS was evidenced by nearly preventing amyloid plaque formation, as shown in the histopathological examination of rat brain. Conclusion RLs could be a potential drug-delivery system for ameliorating Alzheimer’s disease. PMID:23378761

Increased hippocampal activation in ApoE-4 carriers and non-carriers with amnestic mild cognitive impairment.

PubMed

Tran, Tammy T; Speck, Caroline L; Pisupati, Aparna; Gallagher, Michela; Bakker, Arnold

2017-01-01

Increased fMRI activation in the hippocampus is recognized as a signature characteristic of the amnestic mild cognitive impairment (aMCI) stage of Alzheimer's disease (AD). Previous work has localized this increased activation to the dentate gyrus/CA3 subregion of the hippocampus and showed a correlation with memory impairments in those patients. Increased hippocampal activation has also been reported in carriers of the ApoE-4 allelic variation independently of mild cognitive impairment although these findings were not localized to a hippocampal subregion. To assess the ApoE-4 contribution to increased hippocampal fMRI activation, patients with aMCI genotyped for ApoE-4 status and healthy age-matched control participants completed a high-resolution fMRI scan while performing a memory task designed to tax hippocampal subregion specific functions. Consistent with previous reports, patients with aMCI showed increased hippocampal activation in the left dentate gyrus/CA3 region of the hippocampus as well as memory task errors attributable to this subregion. However, this increased fMRI activation in the hippocampus did not differ between ApoE-4 carriers and ApoE-4 non-carriers and the proportion of memory errors attributable to dentate gyrus/CA3 function did not differ between ApoE-4 carriers and ApoE-4 non-carriers. These results indicate that increased fMRI activation of the hippocampus observed in patients with aMCI is independent of ApoE-4 status and that ApoE-4 does not contribute to the dysfunctional hippocampal activation or the memory errors attributable to this subregion in these patients.

Alkylphenol Xenoestrogens with Varying Carbon Chain Lengths Differentially and Potently Activate Signaling and Functional Responses in GH3/B6/F10 Somatomammotropes

PubMed Central

Kochukov, Mikhail Y.; Jeng, Yow-Jiun; Watson, Cheryl S.

2009-01-01

Background Alkylphenols varying in their side-chain lengths [ethyl-, propyl-, octyl-, and nonylphenol (EP, PP, OP, and NP, respectively)] and bisphenol A (BPA) represent a large group of structurally related xenoestrogens that have endocrine-disruptive effects. Their rapid nongenomic effects that depend on structure for cell signaling and resulting functions are unknown. Objectives We compared nongenomic estrogenic activities of alkylphenols with BPA and 17β-estradiol (E2) in membrane estrogen receptor-α–enriched GH3/B6/F10 pituitary tumor cells. These actions included calcium (Ca) signaling, prolactin (PRL) release, extracellular-regulated kinase (ERK) phosphorylation, and cell proliferation. Methods We imaged Ca using fura-2, measured PRL release via radioimmunoassay, detected ERK phosphorylation by fixed cell immunoassay, and estimated cell number using the crystal violet assay. Results All compounds caused increases in Ca oscillation frequency and intracellular Ca volume at 100 fM to 1 nM concentrations, although long-chain alkylphenols were most effective. All estrogens caused rapid PRL release at concentrations as low as 1 fM to 10 pM; the potency of EP, PP, and NP exceeded that of E2. All compounds at 1 nM produced similar increases in ERK phosphorylation, causing rapid peaks at 2.5–5 min, followed by inactivation and additional 60-min peaks (except for BPA). Dose–response patterns of ERK activation at 5 min were similar for E2, BPA, and PP, whereas EP caused larger effects. Only E2 and NP increased cell number. Some rapid estrogenic responses showed correlations with the hydrophobicity of estrogenic molecules; the more hydrophobic OP and NP were superior at Ca and cell proliferation responses, whereas the less hydrophobic EP and PP were better at ERK activations. Conclusions Alkylphenols are potent estrogens in evoking these nongenomic responses contributing to complex functions; their hydrophobicity can largely predict these behaviors. PMID:19479013

Insights into the Prostanoid Pathway in the Ovary Development of the Penaeid Shrimp Penaeus monodon

PubMed Central

Wimuttisuk, Wananit; Tobwor, Punsa; Deenarn, Pacharawan; Danwisetkanjana, Kannawat; Pinkaew, Decha; Kirtikara, Kanyawim; Vichai, Vanicha

2013-01-01

The prostanoid pathway converts polyunsaturated fatty acids (PUFAs) into bioactive lipid mediators, including prostaglandins, thromboxanes and prostacyclins, all of which play vital roles in the immune and reproductive systems in most animal phyla. In crustaceans, PUFAs and prostaglandins have been detected and often associated with female reproductive maturation. However, the presence of prostanoid biosynthesis genes remained in question in these species. In this study, we outlined the prostanoid pathway in the black tiger shrimp Penaeus monodon based on the amplification of nine prostanoid biosynthesis genes: cytosolic phospholipase A2, hematopoietic prostaglandin D synthase, glutathione-dependent prostaglandin D synthase, prostaglandin E synthase 1, prostaglandin E synthase 2, prostaglandin E synthase 3, prostaglandin F synthase, thromboxane A synthase and cyclooxygenase. TBLASTX analysis confirmed the identities of these genes with 51-99% sequence identities to their closest homologs. In addition, prostaglandin F2α (PGF2α), which is a product of the prostaglandin F synthase enzyme, was detected for the first time in P. monodon ovaries along with the previously identified PUFAs and prostaglandin E2 (PGE2) using RP-HPLC and mass-spectrometry. The prostaglandin synthase activity was also observed in shrimp ovary homogenates using in vitro activity assay. When prostaglandin biosynthesis was examined in different stages of shrimp ovaries, we found that the amounts of prostaglandin F synthase gene transcripts and PGF2α decreased as the ovaries matured. These findings not only indicate the presence of a functional prostanoid pathway in penaeid shrimp, but also suggest a possible role of the PGF2α biosynthesis in shrimp ovarian development. PMID:24116186

Loss of 4E-BP1 function induces EMT and promotes cancer cell migration and invasion via cap-dependent translational activation of snail

PubMed Central

She, Qing-Bai

2014-01-01

The cap-dependent translation is frequently deregulated in a variety of cancers associated with tumor progression. However, the molecular basis of the translation activation for metastatic progression of cancer remains largely elusive. Here, we demonstrate that activation of cap-dependent translation by silencing the translational repressor 4E-BP1 causes cancer epithelial cells to undergo epithelial-mesenchymal transition (EMT), which is associated with selective upregulation of the EMT inducer Snail followed by repression of E-cadherin expression and promotion of cell migratory and invasive capabilities as well as metastasis. Conversely, inhibition of cap-dependent translation by a dominant active mutant 4E-BP1 effectively downregulates Snail expression and suppresses cell migration and invasion. Furthermore, dephosphorylation of 4E-BP1 by mTORC1 inhibition or directly targeting the translation initiation also profoundly attenuates Snail expression and cell motility, whereas knockdown of 4E-BP1 or overexpression of Snail significantly rescues the inhibitory effects. Importantly, 4E-BP1-regulated Snail expression is not associated with its changes in the level of transcription or protein stability. Together, these findings indicate a novel role of 4E-BP1 in the regulation of EMT and cell motility through translational control of Snail expression and activity, and suggest that targeting cap-dependent translation may provide a promising approach for blocking Snail-mediated metastatic potential of cancer. PMID:24970798

The adaptor protein Crk controls activation and inhibition of natural killer cells.

PubMed

Liu, Dongfang; Peterson, Mary E; Long, Eric O

2012-04-20

Natural killer (NK) cell inhibitory receptors recruit tyrosine phosphatases to prevent activation, induce phosphorylation and dissociation of the small adaptor Crk from cytoskeleton scaffold complexes, and maintain NK cells in a state of responsiveness to subsequent activation events. How Crk contributes to inhibition is unknown. We imaged primary NK cells over lipid bilayers carrying IgG1 Fc to stimulate CD16 and human leukocyte antigen (HLA)-E to inhibit through receptor CD94-NKG2A. HLA-E alone induced Crk phosphorylation in NKG2A(+) NK cells. At activating synapses with Fc alone, Crk was required for the movement of Fc microclusters and their ability to trigger activation signals. At inhibitory synapses, HLA-E promoted central accumulation of both Fc and phosphorylated Crk and blocked the Fc-induced buildup of F-actin. We propose a unified model for inhibitory receptor function: Crk phosphorylation prevents essential Crk-dependent activation signals and blocks F-actin network formation, thereby reducing constraints on subsequent engagement of activation receptors. Copyright © 2012 Elsevier Inc. All rights reserved.

CHARACTERIZATION OF TANK 5F VERTICAL COOLING COIL LEACHATES FOR SELECT RADIONUCLIDES 2011

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

Oji, L.; Diprete, D.

2001-08-17

Two twenty-four inch samples of vertical sections of the cooling coils from Tank 5F, taken from Riser 1, were made available to SRNL by SRR for leaching and characterization of the leachates for select radionuclide trapped in the corrosion layer on the exterior of the cooling coils. One piece of cooling coil sample was obtained from a section of a vertical cooling coil located above the 45-inch elevation from the tank floor and the other also from a vertical section of a cooling coil located below the 45-inch elevation from the tank floor of Tank 5F. Analysis results from bothmore » cooling coils show that the predominant radionuclides contributing to the activity in both coils are strontium-90 and cesium-137. The activities for strontium-90 and cesium-137 in the Tank 5F vertical cooling coil located above the 45-inch elevation of the tank and designated as sample 5-R1-A45 averaged 1.34E-02 {+-} 1.12E-03 and 7.27E-04 {+-} 4.46E-05 Ci/ft{sup 2}, respectively, while the activities for the vertical cooling coil located below the 45-inch elevation of the tank and designated as sample 5-R1-B45 averaged 8.93E-03 {+-} 8.25E-04 for Sr-90 and 8.10E-04 {+-} 6.36E-05 Ci/ft{sup 2} for Cs-137. Other significant activity contributing radionuclides are americium-241 and europium-154/155. With the exception of the analysis result for Pu-241 in the 5-R1-A45 cooling coils samples, the target detection limits for the other radionuclides were met in both cooling coil samples. The detection limits for Pu-241 analyses result in coil sample 5-R1-A45 were not met consistently because of possible background changes during counting.« less

Rap Phosphatase of Virulence Plasmid pXO1 Inhibits Bacillus anthracis Sporulation†

PubMed Central

Bongiorni, Cristina; Stoessel, Ricarda; Shoemaker, Dorinda; Perego, Marta

2006-01-01

This study shows that the Bacillus anthracis pXO1 virulence plasmid carries a Rap-Phr system, BXA0205, which regulates sporulation initiation in this organism. The BXA0205Rap protein was shown to dephosphorylate the Spo0F response regulator intermediate of the phosphorelay signal transduction system that regulates the initiation of the developmental pathway in response to environmental, metabolic, and cell cycle signals. The activity of the Rap protein was shown to be inhibited by the carboxy-terminal pentapeptide generated through an export-import processing pathway from the associated BXA0205Phr protein. Deregulation of the Rap activity by either overexpression or lack of the Phr pentapeptide resulted in severe inhibition of sporulation. Five additional Rap-Phr encoding systems were identified on the chromosome of B. anthracis, one of which, BA3790-3791, also affected sporulation initiation. The results suggest that the plasmid-borne Rap-Phr system may provide a selective advantage to the virulence of B. anthracis. PMID:16385039

Rap phosphatase of virulence plasmid pXO1 inhibits Bacillus anthracis sporulation.

PubMed

Bongiorni, Cristina; Stoessel, Ricarda; Shoemaker, Dorinda; Perego, Marta

2006-01-01

This study shows that the Bacillus anthracis pXO1 virulence plasmid carries a Rap-Phr system, BXA0205, which regulates sporulation initiation in this organism. The BXA0205Rap protein was shown to dephosphorylate the Spo0F response regulator intermediate of the phosphorelay signal transduction system that regulates the initiation of the developmental pathway in response to environmental, metabolic, and cell cycle signals. The activity of the Rap protein was shown to be inhibited by the carboxy-terminal pentapeptide generated through an export-import processing pathway from the associated BXA0205Phr protein. Deregulation of the Rap activity by either overexpression or lack of the Phr pentapeptide resulted in severe inhibition of sporulation. Five additional Rap-Phr encoding systems were identified on the chromosome of B. anthracis, one of which, BA3790-3791, also affected sporulation initiation. The results suggest that the plasmid-borne Rap-Phr system may provide a selective advantage to the virulence of B. anthracis.

Enzymatic hydrolysis of esters containing a tetrazole ring.

PubMed

Łukowska-Chojnacka, Edyta; Mierzejewska, Jolanta

2014-12-01

The lipase-catalyzed enantioselective hydrolysis of acetates containing tetrazole moiety was studied. Among all tested lipases, Novozyme SP 435 allowed to obtain optically active 4-(5-aryl-2H-tetrazol-2yl)butan-2-ol and 1-(5-aryl-2H-tetrazol-2yl)-propan-2-ol and their acetates with the highest optical purities (ee = 95%-99%) and excellent enantioselectivity (E>100). Some of the synthesized tetrazole derivatives were screened for their antifungal activity. Racemic mixtures of 4-[5-(4-chlorophenyl)-2H-tetrazol-2-yl)butan-2-ol as well as pure enantiomers of this compound showed promising antifungal activity against F. sambucinum, F. oxysporum, C. coccodes, and A. niger. © 2014 Wiley Periodicals, Inc.

Three enzymatically active neurotoxins of Clostridium botulinum strain Af84: BoNT/A2, /F4, and /F5.

PubMed

Kalb, Suzanne R; Baudys, Jakub; Smith, Theresa J; Smith, Leonard A; Barr, John R

2014-04-01

Botulinum neurotoxins (BoNTs) are produced by various species of clostridia and are potent neurotoxins which cause the disease botulism, by cleaving proteins needed for successful nerve transmission. There are currently seven confirmed serotypes of BoNTs, labeled A-G, and toxin-producing clostridia typically only produce one serotype of BoNT. There are a few strains (bivalent strains) which are known to produce more than one serotype of BoNT, producing either both BoNT/A and /B, BoNT/A and /F, or BoNT/B and /F, designated as Ab, Ba, Af, or Bf. Recently, it was reported that Clostridium botulinum strain Af84 has three neurotoxin gene clusters: bont/A2, bont/F4, and bont/F5. This was the first report of a clostridial organism containing more than two neurotoxin gene clusters. Using a mass spectrometry based proteomics approach, we report here that all three neurotoxins, BoNT/A2, /F4, and /F5, are produced by C. botulinum Af84. Label free MS(E) quantification of the three toxins indicated that toxin composition is 88% BoNT/A2, 1% BoNT/F4, and 11% BoNT/F5. The enzymatic activity of all three neurotoxins was assessed by examining the enzymatic activity of the neurotoxins upon peptide substrates, which mimic the toxins' natural targets, and monitoring cleavage of the substrates by mass spectrometry. We determined that all three neurotoxins are enzymatically active. This is the first report of three enzymatically active neurotoxins produced in a single strain of Clostridium botulinum.

Effects of Al content and annealing on the phases formation, lattice parameters, and magnetization of A lxF e2B2 (x =1.0 ,1.1 ,1.2 ) alloys

NASA Astrophysics Data System (ADS)

Levin, E. M.; Jensen, B. A.; Barua, R.; Lejeune, B.; Howard, A.; McCallum, R. W.; Kramer, M. J.; Lewis, L. H.

2018-03-01

AlF e2B2 is a ferromagnet with the Curie temperature around 300 K and has the potential to be an outstanding rare-earth free candidate for magnetocaloric applications. However, samples prepared from the melt contain additional phases which affect the functional response of the AlF e2B2 phase. We report on the effects of Al content in samples with the initial (nominal) composition of A lxF e2B2 , where x =1.0 , 1.1, and 1.2 prepared by arc-melting followed by suction casting and annealing. The as-cast A lxF e2B2 alloys contain AlF e2B2 as well as additional phases, including the primary solidifying FeB and A l13F e4 compounds, which are ferromagnetic and paramagnetic, respectively, at 300 K. The presence of these phases makes it difficult to extract the intrinsic magnetic properties of AlF e2B2 phase. Annealing of A lxF e2B2 alloys at 1040 °C for 3 days allows for reaction of the FeB with A l13F e4 to form the AlF e2B2 phase, significantly reduces the amount of additional phases, and results in nearly pure AlF e2B2 phase as confirmed with XRD, magnetization, scanning electron microscopy, and electronic transport. The values of the magnetization, effective magnetic moment per Fe atom, specific heat capacity, electrical resistivity, and Seebeck coefficient for the AlF e2B2 compound have been established.

Genetic Polymorphism of Cytochrome P450 4F2, Vitamin E Level and Histological Response in Adults and Children with Nonalcoholic Fatty Liver Disease Who Participated in PIVENS and TONIC Clinical Trials

PubMed Central

Athinarayanan, Shaminie; Wei, Rongrong; Zhang, Min; Bai, Shaochun; Traber, Maret G.; Yates, Katherine; Cummings, Oscar W.; Molleston, Jean; Liu, Wanqing; Chalasani, Naga

2014-01-01

Vitamin E improved liver histology in children and adults with NAFLD who participated in TONIC and PIVENS clinical trials, but with significant inter-individual variability in its efficacy. Cytochrome P450 4F2 (CYP4F2) is the major enzyme metabolizing Vit E, with two common genetic variants (V433M, rs2108622 and W12G, rs3093105) found to alter its activity. We investigated the relationship between CYP4F2 genotypes, α-tocopherol levels and histological improvement in these two trials. V433M and W12G variants were genotyped in TONIC (n = 155) and PIVENS (n = 213) DNA samples. The relationships between CYP4F2 genotypes, plasma α-tocopherol levels at baseline and weeks 48 (w48) and 96 (w96) and histological end points (overall improvement in liver histology and resolution of NASH) were investigated. As a result, the V433M genotype was significantly associated with baseline plasma α-tocopherol in the TONIC trial (p = 0.004), but not in PIVENS. Among those receiving Vit E treatment, CYP4F2 V433M genotype was associated with significantly decreased plasma α-tocopherol levels at w48 (p = 0.003 for PIVENS and p = 0.026 for TONIC) but not at w96. The w96 α-tocopherol level was significantly associated with resolution of NASH (p = 0.006) and overall histology improvement (p = 0.021)in the PIVENS, but not in the TONIC trial. There was no significant association between CYP4F2 genotypes and histological end points in either trial. Our study suggested the a moderate role of CYP4F2 polymorphisms in affecting the pharmacokinetics of Vit E as a therapeutic agent. In addition, there may be age-dependent relationship between CYP4F2 genetic variability and Vit E pharmacokinetics in NAFLD. PMID:24759732

Electrical conductivity of diopside: evidence for oxygen vacancies

USGS Publications Warehouse

Huebner, J.S.; Voigt, D.E.

1988-01-01

Impedance spectra for two natural single crystals of diopside were obtained at 800 to 1300??C and 1-bar pressure over the frequency range 0.001 Hz to 100 kHz in a system closed to all components but oxygen. At both higher and lower fO2 values, no fO2 dependence of conductivity was observed, indicating the presence of different conduction mechanisms. At temperatures less than 1000??C, the activation energy is 1.3 eV, also suggesting a different conduction mechanism. Thus, at least four regimes are necessary to describe the conductivity of this diopside in T-fO2 space. The approximately -1/(7 ?? 1) value of d(log ??)/d(log fO2) in a high-temperature geologic region suggests a reaction by which oxygen vacancies control the conductivity. This relatively pure diopside is much less conducting than olivine or orthopyroxene. A second diopside with greater Fe content but otherwise similar in composition to the near-end-member diopside, is more conducting, has a smaller activation energy (1.0 eV) over the range 1050 to 1225??C, and shows only a weak negative fO2 dependence; suggesting that oxygen vacancies are present but are not the dominant defect in controlling the conductivity. -from Authors

Deregulation? Early Radio Policy Reconsidered.

ERIC Educational Resources Information Center

Benjamin, Louise M.

In debating the merits of the deregulation of broadcasting, policy makers should be cognizant of the conditions that led originally to that regulation. An examination of (1) the letters and speeches of Secretary of Commerce, Herbert Hoover, the first regulator of broadcasting; (2) the congressional debate over the regulatory issues of monopoly,…

Assessment of the effectiveness of physical activity interventions in the Brazilian Unified Health System.

PubMed

Ribeiro, Evelyn Helena Corgosinho; Garcia, Leandro Martin Totaro; Salvador, Emanuel Péricles; Costa, Evelyn Fabiana; Andrade, Douglas Roque; Latorre, Maria do Rosario Dias de Oliveira; Florindo, Alex Antonio

2017-06-26

To assess the effect of interventions on the levels of physical activity of healthy adults, users of the Brazilian Unified Health System and attended by the Family Health Strategy. Non-randomized experimental study with 157 adults allocated in three groups: 1) physical exercise classes (n = 54), 2) health education (n = 54), 3) control (n = 49). The study lasted for18 months, with 12 months of interventions and six months of follow-up after intervention. Assessments took place at the beginning, in the 12 months, and in the 18 months of study. Physical activity has been assessed by questionnaires and accelerometry. For the analyses, we have used the intention-to-treat principle and generalized estimating equations. After 12 months, both intervention groups have increased the minutes of weekly leisure time physical activity and annual scores of physical exercise, leisure and transport-related physical activity. The exercise class group has obtained the highest average annual physical exercises score when compared to the other groups (p < 0.001). In the follow-up period, the exercise class group reduced its annual score (average: -0.3; 95%CI -0.5--0.1), while the health education group increased this score (average: 0.2; 95%CI 0.1-0.4). There have been no differences in the levels of physical activity measured by accelerometry. The interventions have been effective in increasing the practice of physical activity. However, we have observed that the health education intervention was more effective for maintaining the practice of physical activity in the period after intervention. We recommend the use of both interventions to promote physical activity in the Brazilian Unified Health System, according to the local reality of professionals, facilities, and team objectives. Avaliar o efeito de intervenções nos níveis de atividade física de adultos saudáveis, usuários do Sistema Único de Saúde e atendidos pela Estratégia de Saúde da Família. Estudo experimental, não randomizado, com 157 adultos alocados em três grupos: 1) classes de exercícios físicos (n = 54); 2) educação em saúde (n = 54); 3) controle (n = 49). O estudo teve duração de 18 meses, sendo 12 meses de intervenções e seis meses de acompanhamento pós-intervenção. As avaliações ocorreram no início, nos 12 e nos 18 meses de estudo. A atividade física foi avaliada por questionários e por acelerometria. Para as análises, utilizaram-se o princípio de intenção de tratar e equações de estimativas generalizadas. Após 12 meses, ambos os grupos de intervenção aumentaram os minutos semanais de atividade física no lazer e os escores anuais de exercícios físicos, de lazer e de deslocamento. O grupo das classes de exercícios físicos obteve maior média de escore anual de exercícios físicos em comparação com os outros grupos (p < 0,001). No período pós-intervenção, o grupo de classes de exercícios físicos reduziu o escore anual de exercícios físicos (média: -0,3; IC95% -0,5--0,1), enquanto o grupo de educação em saúde aumentou este escore (média: 0,2; IC95% 0,1-0,4). Não houve diferenças nos níveis de atividade física mensurados por acelerometria. As intervenções foram efetivas para aumentar a prática de atividade física. No entanto, observou-se que a intervenção de educação em saúde foi mais efetiva para a manutenção da prática de atividade física no período pós-intervenção. Recomenda-se a utilização de ambas as intervenções para a promoção da atividade física no Sistema Único de Saúde, de acordo com as realidades locais de profissionais, instalações e objetivos das equipes.

HER2 signaling drives DNA anabolism and proliferation through SRC-3 phosphorylation and E2F1-regulated genes

PubMed Central

Nikolai, Bryan C.; Lanz, Rainer B.; York, Brian; Dasgupta, Subhamoy; Mitsiades, Nicholas; Creighton, Chad J.; Tsimelzon, Anna; Hilsenbeck, Susan G.; Lonard, David M.; Smith, Carolyn L.; O’Malley, Bert W.

2016-01-01

Approximately 20% of early-stage breast cancers display amplification or overexpression of the ErbB2/HER2 oncogene, conferring poor prognosis and resistance to endocrine therapy. Targeting HER2+ tumors with trastuzumab or the receptor tyrosine kinase (RTK) inhibitor lapatinib significantly improves survival, yet tumor resistance and progression of metastatic disease still develop over time. While the mechanisms of cytosolic HER2 signaling are well studied, nuclear signaling components and gene regulatory networks that bestow therapeutic resistance and limitless proliferative potential are incompletely understood. Here, we use biochemical and bioinformatic approaches to identify effectors and targets of HER2 transcriptional signaling in human breast cancer. Phosphorylation and activity of the Steroid Receptor Coactivator-3 (SRC-3) is reduced upon HER2 inhibition, and recruitment of SRC-3 to regulatory elements of endogenous genes is impaired. Transcripts regulated by HER2 signaling are highly enriched with E2F1 binding sites and define a gene signature associated with proliferative breast tumor subtypes, cell cycle progression, and DNA replication. We show that HER2 signaling promotes breast cancer cell proliferation through regulation of E2F1-driven DNA metabolism and replication genes together with phosphorylation and activity of the transcriptional coactivator SRC-3. Furthermore, our analyses identified a cyclin dependent kinase (CDK) signaling node that, when targeted using the CDK4/6 inhibitor Palbociclib, defines overlap and divergence of adjuvant pharmacological targeting. Importantly, lapatinib and palbociclib strictly block de novo synthesis of DNA, mostly through disruption of E2F1 and its target genes. These results have implications for rational discovery of pharmacological combinations in pre-clinical models of adjuvant treatment and therapeutic resistance. PMID:26833126

ATM Mediates pRB Function To Control DNMT1 Protein Stability and DNA Methylation

PubMed Central

Suzuki, Misa; Hayashi, Naoyuki; Kobayashi, Masahiko; Sasaki, Nobunari; Nishiuchi, Takumi; Doki, Yuichiro; Okamoto, Takahiro; Kohno, Susumu; Muranaka, Hayato; Kitajima, Shunsuke; Yamamoto, Ken-ichi

2013-01-01

The retinoblastoma tumor suppressor gene (RB) product has been implicated in epigenetic control of gene expression owing to its ability to physically bind to many chromatin modifiers. However, the biological and clinical significance of this activity was not well elucidated. To address this, we performed genetic and epigenetic analyses in an Rb-deficient mouse thyroid C cell tumor model. Here we report that the genetic interaction of Rb and ATM regulates DNMT1 protein stability and hence controls the DNA methylation status in the promoters of at least the Ink4a, Shc2, FoxO6, and Noggin genes. Furthermore, we demonstrate that inactivation of pRB promotes Tip60 (acetyltransferase)-dependent ATM activation; allows activated ATM to physically bind to DNMT1, forming a complex with Tip60 and UHRF1 (E3 ligase); and consequently accelerates DNMT1 ubiquitination driven by Tip60-dependent acetylation. Our results indicate that inactivation of the pRB pathway in coordination with aberration in the DNA damage response deregulates DNMT1 stability, leading to an abnormal DNA methylation pattern and malignant progression. PMID:23754744

TGFβ pathway deregulation and abnormal phospho-SMAD2/3 staining in hereditary cerebral hemorrhage with amyloidosis-Dutch type.

PubMed

Grand Moursel, Laure; Munting, Leon P; van der Graaf, Linda M; van Duinen, Sjoerd G; Goumans, Marie-Jose T H; Ueberham, Uwe; Natté, Remco; van Buchem, Mark A; van Roon-Mom, Willeke M C; van der Weerd, Louise

2017-05-29

Hereditary cerebral hemorrhage with amyloidosis-Dutch type (HCHWA-D) is an early onset hereditary form of cerebral amyloid angiopathy (CAA) pathology, caused by the E22Q mutation in the amyloid β (Aβ) peptide. Transforming growth factor β1 (TGFβ1) is a key player in vascular fibrosis and in the formation of angiopathic vessels in transgenic mice. Therefore, we investigated whether the TGFβ pathway is involved in HCHWA-D pathogenesis in human postmortem brain tissue from frontal and occipital lobes. Components of the TGFβ pathway were analyzed with quantitative RT-PCR. TGFβ1 and TGFβ Receptor 2 (TGFBR2) gene expression levels were significantly increased in HCHWA-D in comparison to the controls, in both frontal and occipital lobes. TGFβ-induced pro-fibrotic target genes were also upregulated. We further assessed pathway activation by detecting phospho-SMAD2/3 (pSMAD2/3), a direct TGFβ down-stream signaling mediator, using immunohistochemistry. We found abnormal pSMAD2/3 granular deposits specifically on HCHWA-D angiopathic frontal and occipital vessels. We graded pSMAD2/3 accumulation in angiopathic vessels and found a positive correlation with the CAA load independent of the brain area. We also observed pSMAD2/3 granules in a halo surrounding occipital vessels, which was specific for HCHWA-D. The result of this study indicates an upregulation of TGFβ1 in HCHWA-D, as was found previously in AD with CAA pathology. We discuss the possible origins and implications of the TGFβ pathway deregulation in the microvasculature in HCHWA-D. These findings identify the TGFβ pathway as a potential biomarker of disease progression and a possible target of therapeutic intervention in HCHWA-D. © 2017 The Authors. Brain Pathology published by John Wiley & Sons Ltd on behalf of International Society of Neuropathology.

Penicyclones A-E, Antibacterial Polyketides from the Deep-Sea-Derived Fungus Penicillium sp. F23-2.

PubMed

Guo, Wenqiang; Zhang, Zhenzhen; Zhu, Tianjiao; Gu, Qianqun; Li, Dehai

2015-11-25

Five new ambuic acid analogues, penicyclones A-E (1-5), were isolated from the extract of the deep-sea-derived fungus Penicillium sp. F23-2. The structures including the absolute configurations were established by interpretation of NMR and MS data, as well as the application of ECD, X-ray crystallography, and a chemical conversion, as well as the TDDFT-ECD calculations. Penicyclones A-E (1-5) exhibited antimicrobial activity against the Gram-positive bacterium Staphylococcus aureus with MIC values ranging from 0.3 to 1.0 μg/mL.

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

Deregulation of the miRNAs Expression in Cervical Cancer: Human Papillomavirus Implications

PubMed Central

Gómez-Gómez, Yazmín; Organista-Nava, Jorge; Gariglio, Patricio

2013-01-01

MicroRNAs (miRNAs) are a class of small non coding RNAs of 18–25 nucleotides in length. The temporal or short-lived expression of the miRNAs modulates gene expression post transcriptionally. Studies have revealed that miRNAs deregulation correlates and is involved with the initiation and progression of human tumors. Cervical cancer (CC) displays notably increased or decreased expression of a large number of cellular oncogenic or tumor suppressive miRNAs, respectively. However, understanding the potential role of miRNAs in CC is still limited. In CC, the high-risk human papillomaviruses (HR-HPVs) infection can affect the miRNAs expression through oncoprotein E6 and E7 that contribute to viral pathogenesis, although other viral proteins might also be involved. This deregulation in the miRNAs expression has an important role in the hallmarks of CC. Interestingly, the miRNA expression profile in CC can discriminate between normal and tumor tissue and the extraordinary stability of miRNAs makes it suitable to serve as diagnostic and prognostic biomarkers of cancer. In this review, we will summarize the role of the HR-HPVs in miRNA expression, the role of miRNAs in the hallmarks of CC, and the use of miRNAs as potential prognostic biomarkers in CC. PMID:24490161

The Use of a Higher Order Kinematic Relationship on the Analysis of Cylindrical Composite Panels

DTIC Science & Technology

1991-12-01

form: exNl All A 12 A 16 B11 B12 B16 D nl D12 D16 E11 E12 E16 F11 F12 F16 COyI A12 A22 A6 B12 B22 B 1 D 2 D22 D26 E12 E2 2 E16 F1 2 F22 F26 0 A16 A 26...2 + 2E,,)kw,, ,., " kErWly + (kE11 + B 1 1)4f.,. + 2(kE 6 B16 )*.,x,, + (kE6 6 + B 616 ) *X,yy + (kE 1 6 + B 1 6 ) *y,, + [k (E1 2 + E6 6 ) " B12...B1 6 ) *x, y " (kE1 6 + B1 6 ) 1Y~ + (kE31 2 + B12) p,y, + -R-- 1 O 2 - B16 o, x + 12 W- 16W y- kF12 W, y - Wk16 + D6 x x-a W k 12 + D1 2)4r,y, 0 auo

Deregulation of miRNAs Contributes to Development and Progression of Prostate Cancer

DTIC Science & Technology

2012-09-01

p14ARF gene were co-transfected with miR-125b into LNCaP cells. Cotransfection resulted in approximately 50% reduction of the enzyme activity (Fig...Figure3. Downregulation of miR-125b activity induces apoptosis in p53-null CaP cells. A) Western blot analysis of p14ARF and...miR-124-mediated downregulation of the AR affects the AR activity , both AR- positive LNCaP and C4-2B were treated with miR-124 mimic. Western blot

Cartography of Pathway Signal Perturbations Identifies Distinct Molecular Pathomechanisms in Malignant and Chronic Lung Diseases

PubMed Central

Arakelyan, Arsen; Nersisyan, Lilit; Petrek, Martin; Löffler-Wirth, Henry; Binder, Hans

2016-01-01

Lung diseases are described by a wide variety of developmental mechanisms and clinical manifestations. Accurate classification and diagnosis of lung diseases are the bases for development of effective treatments. While extensive studies are conducted toward characterization of various lung diseases at molecular level, no systematic approach has been developed so far. Here we have applied a methodology for pathway-centered mining of high throughput gene expression data to describe a wide range of lung diseases in the light of shared and specific pathway activity profiles. We have applied an algorithm combining a Pathway Signal Flow (PSF) algorithm for estimation of pathway activity deregulation states in lung diseases and malignancies, and a Self Organizing Maps algorithm for classification and clustering of the pathway activity profiles. The analysis results allowed clearly distinguish between cancer and non-cancer lung diseases. Lung cancers were characterized by pathways implicated in cell proliferation, metabolism, while non-malignant lung diseases were characterized by deregulations in pathways involved in immune/inflammatory response and fibrotic tissue remodeling. In contrast to lung malignancies, chronic lung diseases had relatively heterogeneous pathway deregulation profiles. We identified three groups of interstitial lung diseases and showed that the development of characteristic pathological processes, such as fibrosis, can be initiated by deregulations in different signaling pathways. In conclusion, this paper describes the pathobiology of lung diseases from systems viewpoint using pathway centered high-dimensional data mining approach. Our results contribute largely to current understanding of pathological events in lung cancers and non-malignant lung diseases. Moreover, this paper provides new insight into molecular mechanisms of a number of interstitial lung diseases that have been studied to a lesser extent. PMID:27200087

Understanding of the sources of the F-region field-aligned irregularities in the middle latitude using ground-based and satellite observations

NASA Astrophysics Data System (ADS)

Kwak, Y. S.; Kil, H.; Yang, T. Y.; Park, J.; Choi, J. M.

2017-12-01

The electron density irregularities in the F region are problematic in satellite communication and navigation systems. Extensive efforts have been made to understand the onset conditions and sources of such irregularities and to predict or avoid the impact of these irregularities on the society. A VHF radar was built at Daejeon (36.2°N, 127.1°E, 26.7°N dip latitude) in South Korea in December 2009 to study the characteristics and source of the irregularities in middle latitudes. Our study investigates the occurrence climatology of the field-aligned irregularities (FAIs) and their association with medium-scale traveling ionospheric disturbances (MSTIDs) and sporadic E. The activity of FAIs is investigated with the Daejeon radar data acquired in 2010-2016, and the occurrences of MSTIDs and sporadic E are monitored with the total electron content maps over Japan and ionosonde data at Icheon in South Korea, respectively. Swarm satellite observations are used to investigate the field-aligned properties in the F-region FAIs. Through the comparison of the activities of F-region FAIs, MSTIDs, and sporadic E, we assess the role of MSTIDs and sporadic E in the creation of the F-region FAIs.

Altered microRNA expression patterns in irradiated hematopoietic tissues suggest a sex-specific protective mechanism

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

Ilnytskyy, Yaroslav; Zemp, Franz J.; Koturbash, Igor

To investigate involvement of miRNAs in radiation responses we used microRNAome profiling to analyze the sex-specific response of radiation sensitive hematopoietic lymphoid tissues. We show that radiation exposure resulted in a significant and sex-specific deregulation of microRNA expression in murine spleen and thymus tissues. Among the regulated miRNAs, we found that changes in expression of miR-34a and miR-7 may be involved in important protective mechanisms counteracting radiation cytotoxicity. We observed a significant increase in the expression of tumor-suppressor miR-34a, paralleled by a decrease in the expression of its target oncogenes NOTCH1, MYC, E2F3 and cyclin D1. Additionally, we show thatmore » miR-7 targets the lymphoid-specific helicase LSH, a pivotal regulator of DNA methylation and genome stability. While miR-7 was significantly down-regulated LSH was significantly up-regulated. These cellular changes may constitute an attempt to counteract radiation-induced hypomethylation. Tissue specificity of miRNA responses and possible regulation of miRNA expression upon irradiation are discussed.« less

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

Kanai, Dai; Ueda, Atsushi; Akagi, Tadayuki

Embryonic stem (ES) cells, derived from the inner cell mass of blastocysts, have a characteristic cell cycle with truncated G1 and G2 phases. Recent findings that suppression of Oct3/4 expression results in a reduced proliferation rate of ES cells suggest the involvement of Oct3/4 in the regulation of ES cell growth, although the underlying molecular mechanism remains unclear. In the present study, we identified E2F3a as a direct target gene of Oct3/4 in ES cells. Oct3/4 directly bound to the promoter region of the E2F3a gene and positively regulated expression of E2F3a in mouse ES cells. Suppression of E2F3a activitymore » by E2F6 overexpression led to the reduced proliferation in ES cells, which was relieved by co-expression of E2F3a. Furthermore, cell growth retardation caused by loss of Oct3/4 was rescued by E2F3a expression. These results suggest that Oct3/4 upregulates E2F3a expression to promote ES cell growth. - Highlights: • Oct3/4 positively regulates E2F3a expression in ES cells. • Oct3/4 binds to the promoter region of the E2F3a gene. • Overexpression of E2F6, an inhibitor of E2F3a, reduces ES cell growth. • E2F3a recovers growth retardation of ES cells caused by Oct3/4 reduction.« less

Phytochemical and biological studies of Atriplex inflata f. Muell.: isolation of secondary bioactive metabolites.

PubMed

Ben Nejma, Aymen; Znati, Mansour; Nguir, Asma; Daich, Adam; Othman, Mohamed; Lawson, Ata Martin; Ben Jannet, Hichem

2017-08-01

This work describes the phytochemical and biological investigation of the Tunisian Atriplex inflata F. Muell (Chenopodiaceae). Their chemical structures were elucidated on the basis of extensive spectroscopic methods, including 1D NMR and 2D NMR, ESI-HRMS and comparison with available literature data. The isolates were evaluated for their antioxidant activity by the DPPH • , ABTS +• , Fe 3+ and catalase assays and also for their antibacterial and anticholinesterase activity. The chemical study of Atriplex inflata F. Muell led to the isolation of two fatty acids (9E)-methyl-8,11,12-trihydroxyoctadec-9-enoate 1 and (9E)-8,11,12-trihydroxyoctadecenoic acid 2 together with (Z)-litchiol B 3 and 20-hydroxyecdysone 4. Three of which are reported here for the first time in Atriplex genus. Based on the biosynthesis of hydroxylated arachidonic acid and derivatives, a plausible biogenesis pathway of the two fatty acids (1 and 2) was proposed. (Z)-litchiol B (3) was found to be the most active against Staphylococcus aureus. According to the literature, this is the first time that compounds 1, 2 and 3 were tested for their eventual biological activity. In the results of the present work, we have proposed the biogenesis pathway of unsaturated fatty acid and described the structure-activity relationship. © 2017 Royal Pharmaceutical Society.

Myeloid malignancies: mutations, models and management

PubMed Central

2012-01-01

Myeloid malignant diseases comprise chronic (including myelodysplastic syndromes, myeloproliferative neoplasms and chronic myelomonocytic leukemia) and acute (acute myeloid leukemia) stages. They are clonal diseases arising in hematopoietic stem or progenitor cells. Mutations responsible for these diseases occur in several genes whose encoded proteins belong principally to five classes: signaling pathways proteins (e.g. CBL, FLT3, JAK2, RAS), transcription factors (e.g. CEBPA, ETV6, RUNX1), epigenetic regulators (e.g. ASXL1, DNMT3A, EZH2, IDH1, IDH2, SUZ12, TET2, UTX), tumor suppressors (e.g. TP53), and components of the spliceosome (e.g. SF3B1, SRSF2). Large-scale sequencing efforts will soon lead to the establishment of a comprehensive repertoire of these mutations, allowing for a better definition and classification of myeloid malignancies, the identification of new prognostic markers and therapeutic targets, and the development of novel therapies. Given the importance of epigenetic deregulation in myeloid diseases, the use of drugs targeting epigenetic regulators appears as a most promising therapeutic approach. PMID:22823977

17-Beta-estradiol inhibits transforming growth factor-beta signaling and function in breast cancer cells via activation of extracellular signal-regulated kinase through the G protein-coupled receptor 30.

PubMed

Kleuser, Burkhard; Malek, Daniela; Gust, Ronald; Pertz, Heinz H; Potteck, Henrik

2008-12-01

Breast cancer development and breast cancer progression involves the deregulation of growth factors leading to uncontrolled cellular proliferation, invasion and metastasis. Transforming growth factor (TGF)-beta plays a crucial role in breast cancer because it has the potential to act as either a tumor suppressor or a pro-oncogenic chemokine. A cross-communication between the TGF-beta signaling network and estrogens has been postulated, which is important for breast tumorigenesis. Here, we provide evidence that inhibition of TGF-beta signaling is associated with a rapid estrogen-dependent nongenomic action. Moreover, we were able to demonstrate that estrogens disrupt the TGF-beta signaling network as well as TGF-beta functions in breast cancer cells via the G protein-coupled receptor 30 (GPR30). Silencing of GPR30 in MCF-7 cells completely reduced the ability of 17-beta-estradiol (E2) to inhibit the TGF-beta pathway. Likewise, in GPR30-deficient MDA-MB-231 breast cancer cells, E2 achieved the ability to suppress TGF-beta signaling only after transfection with GPR30-encoding plasmids. It is most interesting that the antiestrogen fulvestrant (ICI 182,780), which possesses agonistic activity at the GPR30, also diminished TGF-beta signaling. Further experiments attempted to characterize the molecular mechanism by which activated GPR30 inhibits the TGF-beta pathway. Our results indicate that GPR30 induces the stimulation of the mitogen-activated protein kinases (MAPKs), which interferes with the activation of Smad proteins. Inhibition of MAPK activity prevented the ability of E2 from suppressing TGF-beta signaling. These findings are of great clinical relevance, because down-regulation of TGF-beta signaling is associated with the development of breast cancer resistance in response to antiestrogens.

Synthesis of biologically active N-methyl derivatives of amidines and cyclized five-membered products of amidines with oxalyl chloride.

PubMed

Sondhi, Sham M; Dinodia, Monica; Jain, Shubhi; Kumar, Ashok

2008-12-01

A series of substituted N-methylisonicotinamidine (2a-f), N-methylpyrazine-2-carboxamidine (2g-i) derivatives were synthesized by reaction of amidine derivatives (1a-i) with methyl iodide in presence of triethylamine. Five-membered condensed dihydroimidazolylbenzenesulfonamide derivatives (3a-i) were obtained by the reaction of amidine derivatives (1a-i) with acylating agent oxalyl chloride. All the compounds, i.e. 2a-i and 3a-i were purified by crystallization. Structures of all the synthesized compounds are supported by correct IR, (1)H NMR, mass spectral and analytical data. Anti-inflammatory activity evaluation was carried out using carrageenan-induced paw oedema assay and compounds 2e, 3a and 3d exhibited good anti-inflammatory activity (44%, 31% and 37% activity at 50 mg/kg p.o., respectively). Analgesic activity evaluation was carried out using acetic acid writhing assay and compounds 2a and 3f gave 75% activity each at 100 mg/kg p.o.; on the other hand compounds 3a and 3d exhibited 60% analgesic activity each at 50 mg/kg p.o. Compounds 3a and 3d exhibited good anti-inflammatory and analgesic activities.

Regulation of RB Transcription In Vivo by RB Family Members▿ ‡

PubMed Central

Burkhart, Deborah L.; Ngai, Lynn K.; Roake, Caitlin M.; Viatour, Patrick; Thangavel, Chellappagounder; Ho, Victoria M.; Knudsen, Erik S.; Sage, Julien

2010-01-01

In cancer cells, the retinoblastoma tumor suppressor RB is directly inactivated by mutation in the RB gene or functionally inhibited by abnormal activation of cyclin-dependent kinase activity. While variations in RB levels may also provide an important means of controlling RB function in both normal and cancer cells, little is known about the mechanisms regulating RB transcription. Here we show that members of the RB and E2F families bind directly to the RB promoter. To investigate how the RB/E2F pathway may regulate Rb transcription, we generated reporter mice carrying an eGFP transgene inserted into a bacterial artificial chromosome containing most of the Rb gene. Expression of eGFP largely parallels that of Rb in transgenic embryos and adult mice. Using these reporter mice and mutant alleles for Rb, p107, and p130, we found that RB family members modulate Rb transcription in specific cell populations in vivo and in culture. Interestingly, while Rb is a target of the RB/E2F pathway in mouse and human cells, Rb expression does not strictly correlate with the cell cycle status of these cells. These experiments identify novel regulatory feedback mechanisms within the RB pathway in mammalian cells. PMID:20100864

Single Cell Analysis to locate the Restriction Point with respect to E2F Expression

NASA Astrophysics Data System (ADS)

Pimienta, R.; Johnson, A.

2011-12-01

The restriction point is a G1-phase checkpoint that regulates passage through the cell cycle and is misregulated in all known types of cancer. The Rb-E2F switch is thought to be one of the most relevant molecular mechanisms which regulate the restriction point in mammalian cells. However, recent experiments have brought the timing of the restriction point into question. In previous studies, cells were analyzed as populations and this prevented an accurate determination of the restriction point. By creating and analyzing an E2F-GFP reporter in single cells, we can pinpoint the timing of E2F activation and determine whether it coincides with the restriction point. Using calcium phosphate and Fugene,we transfected human embryonic kidney (293T) cells with a CMV-GFP plasmid and an E2F-GFP reporter. Based on our results, it appears that calcium phosphate is more effective than Fugene at transfecting mammalian cells. The calcium phosphate transfection had 9.59% more fluorescent cells than Fugene. However, this result only occurred with the CMV-GFP plasmid and not the E2F-GFP reporter, which was not properly expressed in human embryonic kidney (293T) cells. We will continue troubleshooting to fix this reporter as we proceed with our research. Once the reporter is properly cloned, we will transfect it into retinal pigmented epithelial (RPE1-hTERT) cells using the calcium phosphate method. RPE1-hTERT cells are an immortalized with telomerase and are more close to normal cells than tumor-derived cell lines. Through this research we will better comprehend commitment to the mammalian cell cycle.

Molecular Pathways: Disrupting polyamine homeostasis as a therapeutic strategy for neuroblastoma

PubMed Central

Evageliou, Nicholas F.; Hogarty, Michael D.

2009-01-01

MYC genes are deregulated in a plurality of human cancers. Through direct and indirect mechanisms the MYC network regulates the expression of >15% of the human genome, including both protein-coding and non-coding RNAs. This complexity has complicated efforts to define the principal pathways mediating MYC’s oncogenic activity. MYC plays a central role providing for the bioenergetic and biomass needs of proliferating cells, and polyamines are essential cell constituents supporting many of these functions. The rate-limiting enzyme in polyamine biosynthesis, ODC, is a bona fide MYC target, as are other regulatory enzymes in this pathway. A wealth of data link enhanced polyamine biosynthesis to cancer progression, and polyamine-depletion may limit malignant transformation of pre-neoplastic lesions. Studies using transgenic cancer models also supports that the effect of MYC on tumor initiation and progression can be attenuated through repression of polyamine production. High-risk neuroblastomas (an often lethal embryonal tumor in which MYC activation is paramount) deregulate numerous polyamine enzymes to promote expansion of intracellular polyamine pools. Selective inhibition of key enzymes in this pathway, e.g., using DFMO and/or SAM486, reduces tumorigenesis and synergizes with chemotherapy to regress tumors in pre-clinical models. Here we review the potential clinical application of these and additional polyamine-depletion agents to neuroblastoma and other advanced cancers in which MYC is operative. PMID:19789308

New localization and function of calpain-2 in nucleoli of colorectal cancer cells in ribosomal biogenesis: effect of KRAS status

PubMed Central

Telechea-Fernández, Marcelino; Rodríguez-Fernández, Lucia; García, Concha; Zaragozá, Rosa; Viña, Juan; Cervantes, Andrés; García-Trevijano, Elena R.

2018-01-01

Calpain-2 belongs to a family of pleiotropic Cys-proteases with modulatory rather than degradative functions. Calpain (CAPN) overexpression has been controversially correlated with poor prognosis in several cancer types, including colorectal carcinoma (CRC). However, the mechanisms of substrate-recognition, calpain-2 regulation/deregulation and specific functions in CRC remain elusive. Herein, calpain subcellular distribution was studied as a key event for substrate-recognition and consequently, for calpain-mediated function. We describe a new localization for calpain-2 in the nucleoli of CRC cells. Calpain-2 nucleolar distribution resulted dependent on its enzymatic activity and on the mutational status of KRAS. In KRASWT/- cells serum-starvation induced CAPN2 expression, nucleolar accumulation and increased binding to the rDNA-core promoter and intergenic spacer (IGS), concomitant with a reduction in pre-rRNA levels. Depletion of calpain-2 by specific siRNA prevented pre-rRNA down-regulation after serum removal. Conversely, ribosomal biogenesis proceeded in the absence of serum in unresponsive KRASG13D/- cells whose CAPN2 expression, nucleolar localization and rDNA-occupancy remained unchanged during the time-course of serum starvation. We propose here that nucleolar calpain-2 might be a KRAS-dependent sensor to repress ribosomal biogenesis in growth limiting conditions. Under constitutive activation of the pathway commonly found in CRC, calpain-2 is deregulated and tumor cells become insensitive to the extracellular microenvironment. PMID:29507677

New localization and function of calpain-2 in nucleoli of colorectal cancer cells in ribosomal biogenesis: effect of KRAS status.

PubMed

Telechea-Fernández, Marcelino; Rodríguez-Fernández, Lucia; García, Concha; Zaragozá, Rosa; Viña, Juan; Cervantes, Andrés; García-Trevijano, Elena R

2018-02-06

Calpain-2 belongs to a family of pleiotropic Cys-proteases with modulatory rather than degradative functions. Calpain (CAPN) overexpression has been controversially correlated with poor prognosis in several cancer types, including colorectal carcinoma (CRC). However, the mechanisms of substrate-recognition, calpain-2 regulation/deregulation and specific functions in CRC remain elusive. Herein, calpain subcellular distribution was studied as a key event for substrate-recognition and consequently, for calpain-mediated function. We describe a new localization for calpain-2 in the nucleoli of CRC cells. Calpain-2 nucleolar distribution resulted dependent on its enzymatic activity and on the mutational status of KRAS. In KRASWT/- cells serum-starvation induced CAPN2 expression, nucleolar accumulation and increased binding to the rDNA-core promoter and intergenic spacer (IGS), concomitant with a reduction in pre-rRNA levels. Depletion of calpain-2 by specific siRNA prevented pre-rRNA down-regulation after serum removal. Conversely, ribosomal biogenesis proceeded in the absence of serum in unresponsive KRASG13D/- cells whose CAPN2 expression, nucleolar localization and rDNA-occupancy remained unchanged during the time-course of serum starvation. We propose here that nucleolar calpain-2 might be a KRAS-dependent sensor to repress ribosomal biogenesis in growth limiting conditions. Under constitutive activation of the pathway commonly found in CRC, calpain-2 is deregulated and tumor cells become insensitive to the extracellular microenvironment.

Thailand low and equatorial F 2-layer peak electron density and comparison with IRI-2007 model

NASA Astrophysics Data System (ADS)

Wichaipanich, N.; Supnithi, P.; Tsugawa, T.; Maruyama, T.

2012-06-01

Ionosonde measurements obtained at two Thailand ionospheric stations, namely Chumphon (10.72°N, 99.37°E, dip 3.0°N) and Chiang Mai (18.76°N, 98.93°E, dip 12.7°N) are used to examine the variation of the F 2-layer peak electron density ( N m F 2) which is derived from the F 2-layer critical frequency, f o f 2. Measured data from September 2004 to August 2005 (a period of low solar activity) are analyzed based on the diurnal and seasonal variation and then compared with IRI-2007 model predictions. Our results show that, in general, the diurnal and seasonal variations of the N m F 2 predicted by the IRI (URSI and CCIR options) model show a feature generally similar to the observed N m F 2. Underestimation mostly occurs in all seasons except during the September equinox and the December solstice at Chumphon, and the September equinox and the March equinox at Chiang Mai, when they overestimate those measured. The best agreement between observation and prediction occurs during the pre-sunrise to post-sunrise hours. The best agreement of the %PD values of both the options occurs during the March equinox, while the agreement is the worst during the September equinox. The N m F 2 values predicted by the CCIR option show a smaller range of deviation than the N m F 2 values predicted by the URSI option. During post-sunset to morning hours (around 21:00-09:00 LT), the observed N m F 2 at both stations are almost identical for the periods of low solar activity. However, during daytime, the observed N m F 2 at Chumphon is lower than that at Chiang Mai. The difference between these two stations can be explained by the equatorial ionospheric anomaly (EIA). These results are important for future improvements of the IRI model for N m F 2 over Southeast Asia, especially for the areas covered by Chumphon and Chiang Mai stations.

Integrated genomic sequencing reveals mutational landscape of T-cell prolymphocytic leukemia

PubMed Central

Kiel, Mark J.; Velusamy, Thirunavukkarasu; Rolland, Delphine; Sahasrabuddhe, Anagh A.; Chung, Fuzon; Bailey, Nathanael G.; Schrader, Alexandra; Li, Bo; Li, Jun Z.; Ozel, Ayse B.; Betz, Bryan L.; Miranda, Roberto N.; Medeiros, L. Jeffrey; Zhao, Lili; Herling, Marco

2014-01-01

The comprehensive genetic alterations underlying the pathogenesis of T-cell prolymphocytic leukemia (T-PLL) are unknown. To address this, we performed whole-genome sequencing (WGS), whole-exome sequencing (WES), high-resolution copy-number analysis, and Sanger resequencing of a large cohort of T-PLL. WGS and WES identified novel mutations in recurrently altered genes not previously implicated in T-PLL including EZH2, FBXW10, and CHEK2. Strikingly, WGS and/or WES showed largely mutually exclusive mutations affecting IL2RG, JAK1, JAK3, or STAT5B in 38 of 50 T-PLL genomes (76.0%). Notably, gain-of-function IL2RG mutations are novel and have not been reported in any form of cancer. Further, high-frequency mutations in STAT5B have not been previously reported in T-PLL. Functionally, IL2RG-JAK1-JAK3-STAT5B mutations led to signal transducer and activator of transcription 5 (STAT5) hyperactivation, transformed Ba/F3 cells resulting in cytokine-independent growth, and/or enhanced colony formation in Jurkat T cells. Importantly, primary T-PLL cells exhibited constitutive activation of STAT5, and targeted pharmacologic inhibition of STAT5 with pimozide induced apoptosis in primary T-PLL cells. These results for the first time provide a portrait of the mutational landscape of T-PLL and implicate deregulation of DNA repair and epigenetic modulators as well as high-frequency mutational activation of the IL2RG-JAK1-JAK3-STAT5B axis in the pathogenesis of T-PLL. These findings offer opportunities for novel targeted therapies in this aggressive leukemia. PMID:24825865

Integrated genomic sequencing reveals mutational landscape of T-cell prolymphocytic leukemia.

PubMed

Kiel, Mark J; Velusamy, Thirunavukkarasu; Rolland, Delphine; Sahasrabuddhe, Anagh A; Chung, Fuzon; Bailey, Nathanael G; Schrader, Alexandra; Li, Bo; Li, Jun Z; Ozel, Ayse B; Betz, Bryan L; Miranda, Roberto N; Medeiros, L Jeffrey; Zhao, Lili; Herling, Marco; Lim, Megan S; Elenitoba-Johnson, Kojo S J

2014-08-28

The comprehensive genetic alterations underlying the pathogenesis of T-cell prolymphocytic leukemia (T-PLL) are unknown. To address this, we performed whole-genome sequencing (WGS), whole-exome sequencing (WES), high-resolution copy-number analysis, and Sanger resequencing of a large cohort of T-PLL. WGS and WES identified novel mutations in recurrently altered genes not previously implicated in T-PLL including EZH2, FBXW10, and CHEK2. Strikingly, WGS and/or WES showed largely mutually exclusive mutations affecting IL2RG, JAK1, JAK3, or STAT5B in 38 of 50 T-PLL genomes (76.0%). Notably, gain-of-function IL2RG mutations are novel and have not been reported in any form of cancer. Further, high-frequency mutations in STAT5B have not been previously reported in T-PLL. Functionally, IL2RG-JAK1-JAK3-STAT5B mutations led to signal transducer and activator of transcription 5 (STAT5) hyperactivation, transformed Ba/F3 cells resulting in cytokine-independent growth, and/or enhanced colony formation in Jurkat T cells. Importantly, primary T-PLL cells exhibited constitutive activation of STAT5, and targeted pharmacologic inhibition of STAT5 with pimozide induced apoptosis in primary T-PLL cells. These results for the first time provide a portrait of the mutational landscape of T-PLL and implicate deregulation of DNA repair and epigenetic modulators as well as high-frequency mutational activation of the IL2RG-JAK1-JAK3-STAT5B axis in the pathogenesis of T-PLL. These findings offer opportunities for novel targeted therapies in this aggressive leukemia. © 2014 by The American Society of Hematology.

Human butyrylcholinesterase components differ in aryl acylamidase activity.

PubMed

Montenegro, María F; María, T Moral-Naranjo; de la Cadena, María Páez; Campoy, Francisco J; Muñoz-Delgado, Encarnación; Vidal, Cecilio J

2008-04-01

Apart from its esterase activity, butyrylcholinesterase (BuChE) displays aryl acylamidase (AAA) activity able to hydrolyze o-nitroacetanilide (ONA) and its trifluoro-derivative (F-ONA). We report here that, despite amidase and esterase sites residing in the same protein, in human samples depleted of acetylcholinesterase the ratio of amidase to esterase activity varied depending on the source of BuChE. The much faster degradation of ONA and F-ONA by BuChE monomers (G1) of colon and kidney than by the tetramers (G4) suggests aggregation-driven differences in the AAA site between single and polymerized subunits. The similar ratio of F-ONAto butyrylthiocholine hydrolysis by serum G1 and G4 forms support structural differences in the amidase site according to the source of BuChE. The changing ratios of amidase to esterase activities in the human sources probably arise from post-translational modifications in BuChE subunits, the specific proportion of monomers and oligomers and the variable capacity of the tetramers for degrading ONA and F-ONA. The elevated amidase activity of BuChE monomers and the scant activity of the tetramers justify the occurrence of single BuChE subunits in cells as a means to sustain the AAA activity of BuChE which otherwise could be lost by tetramerization.

Deregulation of tumor angiogenesis and blockade of tumor growth in PPARbeta-deficient mice.

PubMed

Müller-Brüsselbach, Sabine; Kömhoff, Martin; Rieck, Markus; Meissner, Wolfgang; Kaddatz, Kerstin; Adamkiewicz, Jürgen; Keil, Boris; Klose, Klaus J; Moll, Roland; Burdick, Andrew D; Peters, Jeffrey M; Müller, Rolf

2007-08-08

The peroxisome proliferator-activated receptor-beta (PPARbeta) has been implicated in tumorigenesis, but its precise role remains unclear. Here, we show that the growth of syngeneic Pparb wild-type tumors is impaired in Pparb(-/-) mice, concomitant with a diminished blood flow and an abundance of hyperplastic microvascular structures. Matrigel plugs containing pro-angiogenic growth factors harbor increased numbers of morphologically immature, proliferating endothelial cells in Pparb(-/-) mice, and retroviral transduction of Pparb triggers microvessel maturation. We have identified the Cdkn1c gene encoding the cell cycle inhibitor p57(Kip2) as a PPARbeta target gene and a mediator of the PPARbeta-mediated inhibition of cell proliferation, which provides a possible mechanistic explanation for the observed tumor endothelial hyperplasia and deregulation of tumor angiogenesis in Pparb(-/-) mice. Our data point to an unexpected essential role for PPARbeta in constraining tumor endothelial cell proliferation to allow for the formation of functional tumor microvessels.

Residues Phe103 and Phe149 are critical for the co-chaperone activity of Bacillus licheniformis GrpE.

PubMed

Lin, Min-Guan; Chi, Meng-Chun; Chen, Bo-En; Wang, Tzu-Fan; Lo, Huei-Fen; Lin, Long-Liu

2015-01-01

A tryptophan-free Bacillus licheniformis nucleotide exchange factor (BlGrpE) and its Trp mutants (F70W, F103W, F149W, F70/103W, F70/149W, F103/149W and F70/103/149W) were over-expressed and purified to near homogeneity. Simultaneous addition of B. licheniformis DnaJ, NR-peptide and individual variants synergistically stimulated the ATPase activity of a recombinant DnaK (BlDnaK) from the same bacterium by 3.1-14.7-fold, which are significantly lower than the synergistic stimulation (18.9-fold) of BlGrpE. Protein-protein interaction analysis revealed that Trp mutants relevant to amino acid positions 103 and 149 lost the ability to bind BlDnaK. Circular dichroism measurements indicate that F70W displayed a comparable level of secondary structure to that of BlGrpE, and the wild-type protein and the Trp mutants as well all experienced a reversible behavior of thermal denaturation. Guanidine hydrochloride (GdnHCl)-induced unfolding transition for BlGrpE was calculated to be 1.25 M corresponding to ΔG(N-U) of 4.29 kcal/mol, whereas the unfolding transitions of mutant proteins were in the range of 0.77-1.31 M equivalent to ΔG(N-U) of 2.41-4.14 kcal/mol. Taken together, the introduction of tryptophan residue, especially at positions 103 and 149, into the primary structure of BlGrpE has been proven to be detrimental to structural integrity and proper function of the protein. Copyright © 2014 Elsevier B.V. All rights reserved.

Comparison of semantic and episodic memory BOLD fMRI activation in predicting cognitive decline in older adults.

PubMed

Hantke, Nathan; Nielson, Kristy A; Woodard, John L; Breting, Leslie M Guidotti; Butts, Alissa; Seidenberg, Michael; Carson Smith, J; Durgerian, Sally; Lancaster, Melissa; Matthews, Monica; Sugarman, Michael A; Rao, Stephen M

2013-01-01

Previous studies suggest that task-activated functional magnetic resonance imaging (fMRI) can predict future cognitive decline among healthy older adults. The present fMRI study examined the relative sensitivity of semantic memory (SM) versus episodic memory (EM) activation tasks for predicting cognitive decline. Seventy-eight cognitively intact elders underwent neuropsychological testing at entry and after an 18-month interval, with participants classified as cognitively "Stable" or "Declining" based on ≥ 1.0 SD decline in performance. Baseline fMRI scanning involved SM (famous name discrimination) and EM (name recognition) tasks. SM and EM fMRI activation, along with Apolipoprotein E (APOE) ε4 status, served as predictors of cognitive outcome using a logistic regression analysis. Twenty-seven (34.6%) participants were classified as Declining and 51 (65.4%) as Stable. APOE ε4 status alone significantly predicted cognitive decline (R(2) = .106; C index = .642). Addition of SM activation significantly improved prediction accuracy (R(2) = .285; C index = .787), whereas the addition of EM did not (R(2) = .212; C index = .711). In combination with APOE status, SM task activation predicts future cognitive decline better than EM activation. These results have implications for use of fMRI in prevention clinical trials involving the identification of persons at-risk for age-associated memory loss and Alzheimer's disease.

Targeting deregulated AMPK/mTORC1 pathways improves muscle function in myotonic dystrophy type I.

PubMed

Brockhoff, Marielle; Rion, Nathalie; Chojnowska, Kathrin; Wiktorowicz, Tatiana; Eickhorst, Christopher; Erne, Beat; Frank, Stephan; Angelini, Corrado; Furling, Denis; Rüegg, Markus A; Sinnreich, Michael; Castets, Perrine

2017-02-01

Myotonic dystrophy type I (DM1) is a disabling multisystemic disease that predominantly affects skeletal muscle. It is caused by expanded CTG repeats in the 3'-UTR of the dystrophia myotonica protein kinase (DMPK) gene. RNA hairpins formed by elongated DMPK transcripts sequester RNA-binding proteins, leading to mis-splicing of numerous pre-mRNAs. Here, we have investigated whether DM1-associated muscle pathology is related to deregulation of central metabolic pathways, which may identify potential therapeutic targets for the disease. In a well-characterized mouse model for DM1 (HSALR mice), activation of AMPK signaling in muscle was impaired under starved conditions, while mTORC1 signaling remained active. In parallel, autophagic flux was perturbed in HSALR muscle and in cultured human DM1 myotubes. Pharmacological approaches targeting AMPK/mTORC1 signaling greatly ameliorated muscle function in HSALR mice. AICAR, an AMPK activator, led to a strong reduction of myotonia, which was accompanied by partial correction of misregulated alternative splicing. Rapamycin, an mTORC1 inhibitor, improved muscle relaxation and increased muscle force in HSALR mice without affecting splicing. These findings highlight the involvement of AMPK/mTORC1 deregulation in DM1 muscle pathophysiology and may open potential avenues for the treatment of this disease.

Targeting deregulated AMPK/mTORC1 pathways improves muscle function in myotonic dystrophy type I

PubMed Central

Brockhoff, Marielle; Rion, Nathalie; Chojnowska, Kathrin; Wiktorowicz, Tatiana; Eickhorst, Christopher; Erne, Beat; Frank, Stephan; Angelini, Corrado; Rüegg, Markus A.; Sinnreich, Michael

2017-01-01

Myotonic dystrophy type I (DM1) is a disabling multisystemic disease that predominantly affects skeletal muscle. It is caused by expanded CTG repeats in the 3′-UTR of the dystrophia myotonica protein kinase (DMPK) gene. RNA hairpins formed by elongated DMPK transcripts sequester RNA-binding proteins, leading to mis-splicing of numerous pre-mRNAs. Here, we have investigated whether DM1-associated muscle pathology is related to deregulation of central metabolic pathways, which may identify potential therapeutic targets for the disease. In a well-characterized mouse model for DM1 (HSALR mice), activation of AMPK signaling in muscle was impaired under starved conditions, while mTORC1 signaling remained active. In parallel, autophagic flux was perturbed in HSALR muscle and in cultured human DM1 myotubes. Pharmacological approaches targeting AMPK/mTORC1 signaling greatly ameliorated muscle function in HSALR mice. AICAR, an AMPK activator, led to a strong reduction of myotonia, which was accompanied by partial correction of misregulated alternative splicing. Rapamycin, an mTORC1 inhibitor, improved muscle relaxation and increased muscle force in HSALR mice without affecting splicing. These findings highlight the involvement of AMPK/mTORC1 deregulation in DM1 muscle pathophysiology and may open potential avenues for the treatment of this disease. PMID:28067669

Loss of GCN5 leads to increased neuronal apoptosis by upregulating E2F1- and Egr-1-dependent BH3-only protein Bim.

PubMed

Wu, Yanna; Ma, Shanshan; Xia, Yong; Lu, Yangpeng; Xiao, Shiyin; Cao, Yali; Zhuang, Sidian; Tan, Xiangpeng; Fu, Qiang; Xie, Longchang; Li, Zhiming; Yuan, Zhongmin

2017-01-26

Cellular acetylation homeostasis is a kinetic balance precisely controlled by histone acetyl-transferase (HAT) and histone deacetylase (HDAC) activities. The loss of the counterbalancing function of basal HAT activity alters the precious HAT:HDAC balance towards enhanced histone deacetylation, resulting in a loss of acetylation homeostasis, which is closely associated with neuronal apoptosis. However, the critical HAT member whose activity loss contributes to neuronal apoptosis remains to be identified. In this study, we found that inactivation of GCN5 by either pharmacological inhibitors, such as CPTH2 and MB-3, or by inactivation with siRNAs leads to a typical apoptosis in cultured cerebellar granule neurons. Mechanistically, the BH3-only protein Bim is transcriptionally upregulated by activated Egr-1 and E2F1 and mediates apoptosis following GCN5 inhibition. Furthermore, in the activity withdrawal- or glutamate-evoked neuronal apoptosis models, GCN5 loses its activity, in contrast to Bim induction. Adenovirus-mediated overexpression of GCN5 suppresses Bim induction and apoptosis. Interestingly, the loss of GCN5 activity and the induction of Egr-1, E2F1 and Bim are involved in the early brain injury (EBI) following subarachnoid haemorrhage (SAH) in rats. HDAC inhibition not only significantly rescues Bim expression and apoptosis induced by either potassium deprivation or GCN5 inactivation but also ameliorates these events and EBI in SAH rats. Taken together, our results highlight a new mechanism by which the loss of GCN5 activity promotes neuronal apoptosis through the transcriptional upregulation of Bim, which is probably a critical event in triggering neuronal death when cellular acetylation homeostasis is impaired.

Quorum Sensing Extracellular Death Peptides Enhance the Endoribonucleolytic Activities of Mycobacterium tuberculosis MazF Toxins

PubMed Central

Nigam, Akanksha; Kumar, Sathish

2018-01-01

ABSTRACT mazEF is a toxin-antitoxin module located on chromosomes of most bacteria. MazF toxins are endoribonucleases antagonized by MazE antitoxins. Previously, we characterized several quorum sensing peptides called "extracellular death factors" (EDFs). When secreted from bacterial cultures, EDFs induce interspecies cell death. EDFs also enhance the endoribonucleolytic activity of Escherichia coli MazF. Mycobacterium tuberculosis carries several mazEF modules. Among them, the endoribonucleolytic activities of MazF proteins mt-1, mt-3, and mt-6 were identified. MazF-mt6 and MazF-mt-3 cleave M. tuberculosis rRNAs. Here we report the in vitro effects of EDFs on the endoribonucleolytic activities of M. tuberculosis MazFs. Escherichia coli EDF (EcEDF) and the three Pseudomonas aeruginosa EDFs (PaEDFs) individually enhance the endoribonucleolytic activities of MazF-mt6 and MazF-mt3 and overcome the inhibitory effect of MazE-mt3 or MazE-mt6 on the endoribonucleolytic activities of the respective toxins. We propose that these EDFs can serve as a basis for a novel class of antibiotics against M. tuberculosis. PMID:29717013

Preparation of the oligosaccharides derived from Flammulina velutipes and their antioxidant activities.

PubMed

Xia, Zhenqiang

2015-03-15

The oligosaccharides were prepared from Flammulina velutipes by hydrolysis of F. velutipes polysaccharides with hydrogen peroxide (H2O2). The yields of F. velutipes derived oligosaccharides (FVOs) were monitored during the hydrolysis process. FVOs yields were affected by three factors, i.e. reaction temperature, H2O2 concentration, and time, which were optimized by using an orthogonal design experiments as follows: reaction temperature 70°C, H2O2 concentration 3%, and reaction time 6h. Under these optimum conditions, the maximal yield of the oligosaccharides reached 17.10%, which was higher than that of hot water extraction method. The oligosaccharides were partially characterized by Fourier transform infrared spectrum, monosaccharide composition, and antioxidant activity. The results indicate that the oligosaccharides derived from F. velutipes showed strong hydroxyl radical activity and reducing capacity at the concentration of 100 μg/mL. Copyright © 2014 Elsevier Ltd. All rights reserved.

An oncolytic adenovirus vector combining enhanced cell-to-cell spreading, mediated by the ADP cytolytic protein, with selective replication in cancer cells with deregulated wnt signaling.

PubMed

Toth, Karoly; Djeha, Hakim; Ying, Baoling; Tollefson, Ann E; Kuppuswamy, Mohan; Doronin, Konstantin; Krajcsi, Peter; Lipinski, Kai; Wrighton, Christopher J; Wold, William S M

2004-05-15

We have constructed a novel oncolytic adenovirus (Ad) vector named VRX-009 that combines enhanced cell spread with tumor-specific replication. Enhanced spread, which could significantly increase antitumor efficacy, is mediated by overexpression of the Ad cytolytic protein named ADP (also known as E3-11.6K). Replication of VRX-009 is restricted to cells with a deregulated wnt signal transduction pathway by replacement of the wild-type Ad E4 promoter with a synthetic promoter consisting of five consensus binding sites for the T-cell factor transcription factor. Tumor-selective replication is indicated by several lines of evidence. VRX-009 expresses E4ORF3, a representative Ad E4 protein, only in colon cancer cell lines. Furthermore, VRX-009 replicates preferentially in colon cancer cell lines as evidenced by virus productivity 2 orders of magnitude higher in SW480 colon cancer cells than in A549 lung cancer cells. Replication in primary human bronchial epithelial cells and human umbilical vein endothelial cells was also significantly lower than in SW480 cells. When tested in human tumor xenografts in nude mice, VRX-009 effectively suppressed the growth of SW480 colon tumors but not of A549 lung tumors. VRX-009 may provide greater level of antitumor efficacy than standard oncolytic Ad vectors in tumors in which a defect in wnt signaling increases the level of nuclear beta-catenin.

Inflammation in Parkinson’s disease: role of glucocorticoids

PubMed Central

Herrero, María-Trinidad; Estrada, Cristina; Maatouk, Layal; Vyas, Sheela

2015-01-01

Chronic inflammation is a major characteristic feature of Parkinson’s disease (PD). Studies in PD patients show evidence of augmented levels of potent pro-inflammatory molecules e.g., TNF-α, iNOS, IL-1β whereas in experimental Parkinsonism it has been consistently demonstrated that dopaminergic neurons are particularly vulnerable to activated glia releasing these toxic factors. Recent genetic studies point to the role of immune system in the etiology of PD, thus in combination with environmental factors, both peripheral and CNS-mediated immune responses could play important roles in onset and progression of PD. Whereas microglia, astrocytes and infiltrating T cells are known to mediate chronic inflammation, the roles of other immune-competent cells are less well understood. Inflammation is a tightly controlled process. One major effector system of regulation is HPA axis. Glucocorticoids (GCs) released from adrenal glands upon stimulation of HPA axis, in response to either cell injury or presence of pathogen, activate their receptor, GR. GR regulates inflammation both through direct transcriptional action on target genes and by indirectly inhibiting transcriptional activities of transcriptional factors such as NF-κB, AP-1 or interferon regulatory factors. In PD patients, the HPA axis is unbalanced and the cortisol levels are significantly increased, implying a deregulation of GR function in immune cells. In experimental Parkinsonism, the activation of microglial GR has a crucial effect in diminishing microglial cell activation and reducing dopaminergic degeneration. Moreover, GCs are also known to regulate human brain vasculature as well as blood brain barrier (BBB) permeability, any dysfunction in their actions may influence infiltration of cytotoxic molecules resulting in increased vulnerability of dopamine neurons in PD. Overall, deregulation of glucocorticoid receptor actions is likely important in dopamine neuron degeneration through establishment of chronic inflammation. PMID:25883554

Shikonin Derivative DMAKO-05 Inhibits Akt Signal Activation and Melanoma Proliferation.

PubMed

Yang, Yao-Yao; He, Hui-Qiong; Cui, Jia-Hua; Nie, Yun-Juan; Wu, Ya-Xian; Wang, Rui; Wang, Gang; Zheng, Jun-Nian; Ye, Richard D; Wu, Qiong; Li, Shao-Shun; Qian, Feng

2016-06-01

DMAKO-05((S)-1-((5E,8E)-5,8-bis(hydroxyimino)-1,4-dimethoxy-5,8-dihydronaphthalen-2-yl)-4-methylpent-3-enyl 3-methylbutanoate) is a novel oxime derivative of shikonin, the major component extracted from Chinese herb Lithospermun erythrorhizon. Here, we report that DMAKO-05 had an antitumor activity against mouse melanoma cell line B16F0. Our studies indicated that DMAKO-05 not only inhibited B16F0 proliferation and migration but also led to cell cycle arrest at G1 phase and cell apoptosis, in which DMAKO-05 triggered mitochondrial-mediated apoptosis signal including caspase-9/3 and PARP. In response to DMAKO-05 treatment, the Akt-mediated survival signals were remarkably attenuated in B16F0 cells. Collectively, DMAKO-05 has a strong cytotoxicity in B16F0 cells via inhibiting Akt activation, inducing G1 arrest, and promoting B16F0 cell apoptosis. DMAKO-05 might serve as a potential candidate lead compound for melanoma. © 2016 John Wiley & Sons A/S.

Discovery of a Highly Selective JAK2 Inhibitor, BMS-911543, for the Treatment of Myeloproliferative Neoplasms

PubMed Central

2015-01-01

JAK2 kinase inhibitors are a promising new class of agents for the treatment of myeloproliferative neoplasms and have potential for the treatment of other diseases possessing a deregulated JAK2-STAT pathway. X-ray structure and ADME guided refinement of C-4 heterocycles to address metabolic liability present in dialkylthiazole 1 led to the discovery of a clinical candidate, BMS-911543 (11), with excellent kinome selectivity, in vivo PD activity, and safety profile. PMID:26288683

Deregulation strategies for local governments and the role/opportunities for energy efficiency services in the utility industry deregulation

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

Tseng, P.C.

As the future shape of the electric utility industry continues to unfold and as retail competition becomes a reality, local governments are faced with balancing the need for: (1) economic development; (2) and to avoid the potential impact of cost-shifting among residents and businesses, while ensuring reliable and universal energy services. Furthermore, local governments need to find ways to recoup potential loss of franchise and tax revenues, to ensure fair and adequate energy-efficiency programs, and to continue other social programs for low income families. This paper will address two important issues every local government in the US are facing: (1)more » the development of viable deregulation strategies before, during and after the promulgation of utility deregulation; (2) opportunities for energy efficiency services in the competitive markets to serve local governments, which typically constitutes the largest market segment in utility's service territory. This paper presents issues and challenges common to all local governments. It documents strategies that several local governments are utilizing to embrace the coming electric utility restructuring and competition challenge to the benefits of their respective communities. This paper presents the results on deregulation work by the City of Portland, Oregon, Barnstable County, Massachusetts, and Montgomery County, Maryland. The research by these local governments was sponsored by the Urban Consortium Energy Task Force and Public Technology, Inc.« less

HER2 Deregulation in Lung Cancer: Right Time to Adopt an Orphan?

PubMed

Cappuzzo, Federico; Landi, Lorenza

2018-06-01

HER2 -deregulated non-small cell lung cancer is an orphan of any specific therapy, probably because of lack of both accurate patient selection and effective drugs. Recent evidence suggests that osimertinib could be effective in HER2 -amplified or mutated lung cancer as a single agent or in combination. Clin Cancer Res; 24(11); 2470-2. ©2018 AACR See related article by Liu et al., p. 2594 . ©2018 American Association for Cancer Research.

Variations of the critical foE-frequency of the ionosphere connected with earthquakes. Evaluation of observations of the vertical sounding station "Tokyo"

NASA Astrophysics Data System (ADS)

Liperovskaya, Elena V.; Meister, Claudia-Veronika; Hoffmann, Dieter H. H.; Silina, Alexandra S.

2016-04-01

In the present work the critical frequencies foE and foF2 of the ionosphere are considered as possible earthquake precursors. The statistical analysis of the critical frequencies is carried out based on the data of the vertical sounding station (VSS) "Kokubunji" ("Tokyo") (ϕ = 35.7o N, λ = 139.5o E, 1957-1988) obtained every hour. Disturbances are considered on the background of seasonal, geomagnetic as well as 11-years and 27-days Solar variations. Special normalized parameters E and F are introduced, which represent the almost seasonal-independent parts of foE and foF2. Days with high Solar (Wolf number > 100) and geomagnetic (ΣKp > 25) activities are excluded from the analysis. For all data (observed every hour) analysed, no correlations of the normalized parameters E and F are found. One day before the seismic shock, a positive correlation is observed. The superimposed epochs method is used to determine the temporal behaviour of E and F. It is found that E and F decrease one day before the earthquakes provided that the seismic shocks occur at distances 600 < R < 1000 km from the VSS, and that the focus of earthquakes with magnitudes M > 5.5 is situated at depths smaller than 60 km. The reliability of the effect is larger than 98 %. Possible physical mechanisms of the phenomenon are discussed.

The Correlation Between Urinary 8-Iso-Prostaglandin F2α and Hydrogen Peroxide Toward Renal Function in T2DM Patients Consuming Sulfonylurea and Combination of Metformin-Sulfonylurea.

PubMed

Sauriasari, Rani; Wulandari, Fitri; Nurifahmi, Rahmaningtyas; Sekar, Andisyah P; Susilo, Veronika Y

2018-01-01

Renal dysfunction is a common complication in type 2 diabetes mellitus patients associated with oxidative damage which could be characterized by 8-iso-prostaglandin F2α and hydrogen peroxide level as oxidative stress markers. The aim of our study is to determine if there is a difference in 8-iso-prostaglandin F2α and hydrogen peroxide levels between sulfonylurea and combination of metformin-sulfonylurea in diabetic patients. We also wanted to determine if these oxidative stress markers correlate with the estimated Glomerular Filtration Rate (eGFR). We conducted a cross-sectional study with inclusion of 55 patients with type 2 diabetes mellitus in Dr. Sitanala Tangerang Hospital, Indonesia with purposive sampling. The value of eGFR was obtained by serum creatinine levels, while the level of 8-iso-prostaglandin F2α was measured by ELISA and urinary hydrogen peroxide using FOX-1 (Ferrous Ion Oxidation Xylenol Orange 1). There was no difference in 8-iso-prostaglandin F2α and hydrogen peroxide level between the two groups (p=0.088 and p=0.848). Moreover, there was no difference in eGFR values between the two groups, measured by Cockroft-Gault, MDRD, and CKD-EPI. 8-iso-prostaglandin F2α (n=55) was positively correlated with eGFR based on Cockroft-Gault (r=0.382; p=0.009), whereas urinary hydrogen peroxide (n=47) also generate significant positive correlation with eGFR based on the MDRD equation (r=0.326; p=0.021). Linear regression analysis showed that 8-iso-prostaglandin F2α is the most predictive factor and the only significant factor for eGFR in Cockroft-Gault, MDRD and also CKDEPI, even after controlled by gender, age, BMI, HbA1c, systole, and H2O2. The two treatments did not have any significant differences in antioxidant activity. However, an increase of urinary 8-iso-prostaglandin F2. and hydrogen peroxide which correlates with eGFR in the total sample may play a significant role in the pathophysiology of diabetic nephropathy. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Synthesis and thermoluminescence characteristics of γ-irradiated K3Ca2(SO4)3F:Eu or Ce fluoride

NASA Astrophysics Data System (ADS)

Poddar, Anuradha; Gedam, S. C.; Dhoble, S. J.

2015-05-01

New halophosphor K3Ca2(SO4)3F activated by Eu and Ce has been synthesized by a co-precipitation method and characterized according to its thermoluminescence. The formation of traps in rare earth doped K3Ca2(SO4)3F and the effects of γ-radiation dose on the glow curve are discussed. The glow curve of K3Ca2(SO4)3F:Ce shows a prominent single peak at 150°C, whereas K3Ca2(SO4)3F:Eu and K3Ca2(SO4)3F:Ce,Eu at 142°C and 192°C, respectively. A single glow peak indicates that there is only one set of trap being activated within the particular temperature range. The presented phosphors are also studied because of its fading, reusability and trapping parameters. There was just 2% fading during a period of 10 days, indicating no serious fading problem. Trapping parameters such as order of kinetics (b), activation energy (E) and frequency factor (S) were calculated by using Chen's half-width method. The observations presented in this paper are good for lamp phosphors as well as solid-state dosimeter.

Ab initio study of dynamical E × e Jahn-Teller and spin-orbit coupling effects in the transition-metal trifluorides TiF3, CrF3, and NiF3

NASA Astrophysics Data System (ADS)

Mondal, Padmabati; Opalka, Daniel; Poluyanov, Leonid V.; Domcke, Wolfgang

2012-02-01

Multiconfiguration ab initio methods have been employed to study the effects of Jahn-Teller (JT) and spin-orbit (SO) coupling in the transition-metal trifluorides TiF3, CrF3, and NiF3, which possess spatially doubly degenerate excited states (ME) of even spin multiplicities (M = 2 or 4). The ground states of TiF3, CrF3, and NiF3 are nondegenerate and exhibit minima of D3h symmetry. Potential-energy surfaces of spatially degenerate excited states have been calculated using the state-averaged complete-active-space self-consistent-field method. SO coupling is described by the matrix elements of the Breit-Pauli operator. Linear and higher order JT coupling constants for the JT-active bending and stretching modes as well as SO-coupling constants have been determined. Vibronic spectra of JT-active excited electronic states have been calculated, using JT Hamiltonians for trigonal systems with inclusion of SO coupling. The effect of higher order (up to sixth order) JT couplings on the vibronic spectra has been investigated for selected electronic states and vibrational modes with particularly strong JT couplings. While the weak SO couplings in TiF3 and CrF3 are almost completely quenched by the strong JT couplings, the stronger SO coupling in NiF3 is only partially quenched by JT coupling.

Hierarchical porous silver metal using Pluronic F-127 and graphene oxide as reinforcing agents for the reduction of o-nitroaniline to 1, 2-benzenediamine

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

Bano, Mustri; Ahirwar, Devendra; Thomas, Molly

An elegant method is used to prepare silver monoliths with Pluronic F-127(F-127) as sacrificial template by modified sol-gel method. Si nanoparticles (SiNPs) and graphene oxide (GO) are added in situ to Ag/F-127 hydrogel for the reduction of ο-nitroaniline (ο-NA) to 1, 2-benzenediamine. Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Thermogravimetric analysis (TGA), Raman Spectroscopy, Powder X-Ray Diffraction (PXRD) analysis and Brunauer-Emmett-Teller (BET) Nitrogen adsorption techniques were used for characterization of monoliths. An epoch-making catalytic activity of Ag/F-127/GO monoliths is observed in the reduction of ο-NA to 1, 2-benzenediamine in presence of NaBH{sub 4} inmore » aqueous media. The catalyst Ag/F-127/GO took only 2 min which is the minimum time reported so far with significant rate constant claimed itself a leading catalyst for the reduction of ο-NA to 1,2-benzenediamine. Pseudo first order rate constant (k) and Turn over frequency (TOF) values are 0.231 min{sup −1} and 30.053×10{sup 19} molecules min{sup −1} respectively suggest that the catalyst has industrial importance. Recyclability and stability of Ag/F-127/GO catalyst are studied successfully up to 10 cycles. Energy of activation (E{sub a}), and thermodynamic parameters viz. activation enthalpy (ΔH{sup ≠}), activation Gibbs free energy (ΔG{sup ≠}), and entropy of activation (ΔS{sup ≠}) were also ascertained. Catalytic activities of Ag/F-127, Ag/F-127/Dextran, Ag/F-127/Trimethylbenzene (TMB), Ag/F-127/SiNPs, and Ag/F-127/Si/GO monoliths were also studied. - Graphical abstract: Significant catalytic activities of silver monoliths against the reduction of ο-NA to 1,2 benzenediamine. - Highlights: • A new catalyst synthesized Ag/F-127/GO for the reduction of ο- NA to 1, 2- benzenediamine took only 2 min. • Turn over frequency of as synthesized catalyst was 30.053×10{sup 19} molecules min{sup −1} claimed itself a leading catalyst. • Recyclability of the catalyst was up to 10 cycles. • The synthesis is non toxic, economically viable and environmentally benign.« less

Hepatocellular carcinomas of the albumin SV40 T-antigen transgenic rat display fetal-like re-expression of lgf2 and deregulation of H19.

PubMed

Czarny, Matthew J; Babcock, Karlee; Baus, Rebecca M; Manoharan, Herbert; Pitot, Henry C

2007-09-01

Previous studies in our laboratory have shown that one of the earliest events during hepatocarcinogenesis in the albumin SV40 T antigen (Alb SV40 T Ag) transgenic rat is the duplication of chromosome 1q3.7-4.3, a region which contains the imprinted and coordinately regulated genes Igf2 and H19. We have also shown that this duplication is associated with the biallelic expression of the normally monoallelically-expressed H19. These results, however, are seemingly at odds with studies in the mouse that have shown a conservation of fetal regulatory patterns of these two genes in hepatic neoplasms. We therefore aimed in this study to determine the allelic origin of Igf2 expression in hepatocellular carcinomas of the Alb SV40 T Ag transgenic rat. Sprague-Dawley Alb SV40 T Ag transgenic rats and Brown Norway rats were reciprocally mated and the expression of Igf2 in hepatocellular carcinomas of the resulting F(1) transgene-positive female rats was analyzed by Northern blotting and RT-PCR. We determined that Igf2 was expressed exclusively from the paternal allele, which prompted the study (by the same methods) of the allelic origin of H19 in the same hepatocellular carcinomas in order to determine if the two genes remained coordinately regulated. Our results demonstrate fetal-like re-expression of Igf2 and deregulation of H19 in singular hepatocellular carcinomas of the rat. These results imply that another regulatory mechanism other than the generally accepted ICR/CTCF mechanism may play a role in the control of Igf2 and H19 expression. (c) 2007 Wiley-Liss, Inc.

S-Nitrosylation of Cofilin-1 Mediates Estradiol-17β-Stimulated Endothelial Cytoskeleton Remodeling

PubMed Central

Zhang, Hong-hai; Lechuga, Thomas J.; Tith, Tevy; Wang, Wen; Wing, Deborah A.

2015-01-01

Rapid nitric oxide (NO) production via endothelial NO synthase (eNOS) activation represents a major signaling pathway for the cardiovascular protective effects of estrogens; however, the pathways after NO biosynthesis that estrogens use to function remain largely unknown. Covalent adduction of a NO moiety to cysteines, termed S-nitrosylation (SNO), has emerged as a key route for NO to directly regulate protein function. Cofilin-1 (CFL1) is a small actin-binding protein essential for actin dynamics and cytoskeleton remodeling. Despite being identified as a major SNO protein in endothelial cells, whether SNO regulates CFL-1 function is unknown. We hypothesized that estradiol-17β (E2β) stimulates SNO of CFL1 via eNOS-derived NO and that E2β-induced SNO-CFL1 mediates cytoskeleton remodeling in endothelial cells. Point mutation studies determined Cys80 as the primary SNO site among the 4 cysteines (Cys39/80/139/147) in CFL1. Substitutions of Cys80 with Ala or Ser were used to prepare the SNO-mimetic/deficient (C80A/S) CFL1 mutants. Recombinant wild-type (wt) and mutant CFL1 proteins were prepared; their actin-severing activity was determined by real-time fluorescence imaging analysis. The activity of C80A CFL1 was enhanced to that of the constitutively active S3/A CFL1, whereas the other mutants had no effects. C80A/S mutations lowered Ser3 phosphorylation. Treatment with E2β increased filamentous (F)-actin and filopodium formation in endothelial cells, which were significantly reduced in cells overexpressing wt-CFL. Overexpression of C80A, but not C80S, CFL1 decreased basal F-actin and further suppressed E2β-induced F-actin and filopodium formation compared with wt-CFL1 overexpression. Thus, SNOCys80 of cofilin-1 via eNOS-derived NO provides a novel pathway for mediating estrogen-induced endothelial cell cytoskeleton remodeling. PMID:25635941

Airline Deregulation and Public Policy

NASA Astrophysics Data System (ADS)

Morrison, Steven A.; Winston, Clifford

1989-08-01

An assessment of the effects of airline deregulation on travelers and carriers indicates that deregulation has provided travelers and carriers with 14.9 billion of annual benefits (1988 dollars). Airport congestion, airline safety, airline bankruptcy, and mergers are also analyzed and found in most cases to have reduced benefits. But, these costs should not be attributed to deregulation per se, but to failures by the government to pursue appropriate policies in these areas. Pursuit of policies that promote airline competition and efficient use of airport capacity would significantly increase the benefits from deregulation and would provide valuable guidance for other industries undergoing the transition to deregulation.

Apoptosis transcriptional mechanism of feline infectious peritonitis virus infected cells.

PubMed

Shuid, Ahmad Naqib; Safi, Nikoo; Haghani, Amin; Mehrbod, Parvaneh; Haron, Mohd Syamsul Reza; Tan, Sheau Wei; Omar, Abdul Rahman

2015-11-01

Apoptosis has been postulated to play an important role during feline infectious peritonitis virus (FIPV) infection; however, its mechanism is not well characterized. This study is focused on apoptosis and transcriptional profiling of FIPV-infected cells following in vitro infection of CRFK cells with FIPV 79-1146 WSU. Flow cytometry was used to determine mode of cell death in first 42 h post infection (hpi). FIPV infected cells underwent early apoptosis at 9 hpi (p < 0.05) followed by late apoptosis at 12 hpi (p < 0.05) and necrosis from 24 hpi (p < 0.05). Then, next generation sequencing was performed on 9 hpi and control uninfected cells by Illumina analyzer. An aggregate of 4546 genes (2229 down-regulated and 2317 up-regulated) from 17 cellular process, 11 molecular functions and 130 possible biological pathways were affected by FIPV. 131 genes from apoptosis cluster (80 down-regulated and 51 up-regulated) along with increase of apoptosis, p53, p38 MAPK, VEGF and chemokines/cytokines signaling pathways were probably involved in apoptosis process. Six of the de-regulated genes expression (RASSF1, BATF2, MAGEB16, PDCD5, TNFα and TRAF2) and TNFα protein concentration were analyzed by RT-qPCR and ELISA, respectively, at different time-points. Up-regulations of both pro-apoptotic (i.e. PDCD5) and anti-apoptotic (i.e. TRAF2) were detected from first hpi and continuing to deregulate during apoptosis process in the infected cells.

NF-κB deregulation in Hodgkin lymphoma.

PubMed

Weniger, Marc A; Küppers, Ralf

2016-08-01

Hodgkin and Reed/Sternberg (HRS) cells in classical Hodgkin lymphoma (HL) show constitutive activity of both the canonical and non-canonical NF-κB signaling pathways. The central pathogenetic role of this activity is indicated from studies with HL cell lines, which undergo apoptosis upon NF-κB inhibition. Multiple factors contribute to the strong NF-κB activity of HRS cells. This includes interaction with other cells in the lymphoma microenvironment through CD30, CD40, BCMA and other receptors, but also recurrent somatic genetic lesions in various factors of the NF-κB pathway, including destructive mutations in negative regulators of NF-κB signaling (e.g. TNFAIP3, NFKBIA), and copy number gains of genes encoding positive regulators (e.g. REL, MAP3K14). In Epstein-Barr virus-positive cases of classical HL, the virus-encoded latent membrane protein 1 causes NF-κB activation by mimicking an active CD40 receptor. NF-κB activity is also seen in the tumor cells of the rare nodular lymphocyte predominant form of HL, but the causes for this activity are largely unclear. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Coast Artillery Journal. Volume 92, Number 2, March-April 1949

DTIC Science & Technology

1949-04-01

population. There were four in ,the vicinity of Ros- tock with fields of fire over the Baltic, one near Fecamp on the Channel, and one near Antwerp...34’~AGA>~, Brig. Gen., SeNG . f f f Lerter to the Editor \\~7e"have a very active reserve organization here-t~ 656th Composite Group, which is shortly going... Hospitals To Care For Army Dependents Naval actIvities having facilities for medical care of de- pendents have been authorized to provide such care for

Catabolism of 6-ketoprostaglandin F1alpha by the rat kidney cortex.

PubMed

Pace-Asciak, C R; Domazet, Z; Carrara, M

1977-05-25

Homogenates of the rat kidney cortex converted 5,8,9,11,12,14,15-hepta-tritiated 6-ketoprostaglandin F 1alpha into one major product identified by gas chromatography-mass spectrometry of the methoxime-methyl ester trimethylsilyl ether derivative as 6,15-diketo-9,11-dihydroxyprost-13-enoic acid. The sequence of derivatisation i.e. methoximation prior to methylation, was crucial as methylation of 15-keto catabolites of the E, F and 6-keto-F series affords degradation products. The corresponding 15-keto-13,14-dihydro catabolite was formed in much smaller quantities. Time course studies indicated that 6-keto-prostaglandin F1alpha was catabolised at a slower rate (about 2-5 fold) than prostaglandin F1alpha. The catabolic activity was blocked by NADH.

Temperature sensing in Yersinia pestis: regulation of yopE transcription by lcrF.

PubMed Central

Hoe, N P; Minion, F C; Goguen, J D

1992-01-01

In Escherichia coli, a yopE::lacZ fusion was found to be regulated by temperature in the presence of the cloned BamHI G fragment of Yersinia pestis plasmid pCD1, which contains the lcrF locus. Increasing the copy number of lcrF relative to that of the yopE reporter had a negligible effect on the induction ratio (26 versus 37 degrees C) but caused large reductions in the absolute levels of yopE transcription. We localized the lcrF gene by monitoring the induction phenotype of BamHI G deletion derivatives. Sequencing revealed an open reading frame capable of encoding a protein of 30.8 kDa. A protein product of this size was detected in a T7 expression system, and LcrF-dependent yopE-specific DNA binding activity was observed. As expected, LcrF exhibited 98% homology to VirF of Yersinia enterocolitica and significant homology to the carboxy termini of other members of the AraC family of transcriptional regulatory proteins. These proteins could be divided into two classes according to function: those regulating operons involved in catabolism of carbon and energy sources and those involved in regulating virulence genes. lcrF::lacZ transcriptional fusions were constructed and analyzed in Y. pestis and E. coli. The activity of the fusions was not affected by the native pCD1 virulence plasmid, an intact lcrF gene, or temperature. Thus, induction of lcrF transcription is not essential for temperature-dependent activation of yopE transcription. A portion of LcrF was found associated with the membrane fraction in E. coli; however, pulse-chase experiments indicated that this result is an artifact of fractionation. Images PMID:1624422

Deregulation of polycomb repressor complex 1 modifier AUTS2 in T-cell leukemia.

PubMed

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

2016-07-19

Recently, we identified deregulated expression of the B-cell specific transcription factor MEF2C in T-cell acute lymphoid leukemia (T-ALL). Here, we performed sequence analysis of a regulatory upstream section of MEF2C in T-ALL cell lines which, however, proved devoid of mutations. Unexpectedly, we found strong conservation between the regulatory upstream region of MEF2C (located at chromosomal band 5q14) and an intergenic stretch at 7q11 located between STAG3L4 and AUTS2, covering nearly 20 kb. While the non-coding gene STAG3L4 was inconspicuously expressed, AUTS2 was aberrantly upregulated in 6% of T-ALL patients (public dataset GSE42038) and in 3/24 T-ALL cell lines, two of which represented very immature differentiation stages. AUTS2 expression was higher in normal B-cells than in T-cells, indicating lineage-specific activity in lymphopoiesis. While excluding chromosomal aberrations, examinations of AUTS2 transcriptional regulation in T-ALL cells revealed activation by IL7-IL7R-STAT5-signalling and MEF2C. AUTS2 protein has been shown to interact with polycomb repressor complex 1 subtype 5 (PRC1.5), transforming this particular complex into an activator. Accordingly, expression profiling and functional analyses demonstrated that AUTS2 activated while PCGF5 repressed transcription of NKL homeobox gene MSX1 in T-ALL cells. Forced expression and pharmacological inhibition of EZH2 in addition to H3K27me3 analysis indicated that PRC2 repressed MSX1 as well. Taken together, we found that AUTS2 and MEF2C, despite lying on different chromosomes, share strikingly similar regulatory upstream regions and aberrant expression in T-ALL subsets. Our data implicate chromatin complexes PRC1/AUTS2 and PRC2 in a gene network in T-ALL regulating early lymphoid differentiation.

A Functional Role of RB-Dependent Pathway in the Control of Quiescence in Adult Epidermal Stem Cells Revealed by Genomic Profiling

PubMed Central

Lorz, Corina; García-Escudero, Ramón; Segrelles, Carmen; Garín, Marina I.; Ariza, José M.; Santos, Mirentxu; Ruiz, Sergio; Lara, María F.; Martínez-Cruz, Ana B.; Costa, Clotilde; Buitrago-Pérez, Águeda; Saiz-Ladera, Cristina; Dueñas, Marta

2010-01-01

Continuous cell renewal in mouse epidermis is at the expense of a pool of pluripotent cells that lie in a well defined niche in the hair follicle known as the bulge. To identify mechanisms controlling hair follicle stem cell homeostasis, we developed a strategy to isolate adult bulge stem cells in mice and to define their transcriptional profile. We observed that a large number of transcripts are underexpressed in hair follicle stem cells when compared to non-stem cells. Importantly, the majority of these downregulated genes are involved in cell cycle. Using bioinformatics tools, we identified the E2F transcription factor family as a potential element involved in the regulation of these transcripts. To determine their functional role, we used engineered mice lacking Rb gene in epidermis, which showed increased expression of most E2F family members and increased E2F transcriptional activity. Experiments designed to analyze epidermal stem cell functionality (i.e.: hair regrowth and wound healing) imply a role of the Rb-E2F axis in the control of stem cell quiescence in epidermis. Electronic supplementary material The online version of this article (doi:10.1007/s12015-010-9139-0) contains supplementary material, which is available to authorized users. PMID:20376578

Description of a local cardiac adiponectin system and its deregulation in dilated cardiomyopathy.

PubMed

Skurk, Carsten; Wittchen, Frank; Suckau, Lennart; Witt, Henning; Noutsias, Michael; Fechner, Henry; Schultheiss, Heinz-Peter; Poller, Wolfgang

2008-05-01

Despite recent advances in medical therapy, heart failure remains a leading cause for cardiovascular mortality, and its complex pathogenesis is incompletely understood. This study was performed to identify possible new therapeutic targets in dilated cardiomyopathy (DCM). Oligonucleotide microarray analysis was performed on endomyocardial biopsies (EMBs) from patients with early DCM (LVEDD > or = 55 mm, LVEF < or = 55%, n = 5) and control subjects (LVEDD < 55 mm, LVEF > 60%, no cardiac pathology, n = 4). Adiponectin, an adipocytokine involved in cellular metabolism, survival, and immunmodulation, was six-fold downregulated in DCM patients. Microarray data for adiponectin were confirmed by TaqMan-PCR (9.2-fold downregulation, control n= 9 vs. DCM n= 9, respectively, P < 0.05). Immunohistological analysis of EMBs showed significant downregulation of cardiac adiponectin protein expression independent of serum adiponectin (P = 0.36, ns) or serum TNFalpha concentrations (P = 0.46, ns). Neither the adiponectin receptor 1 (adipo-R1) nor adipo-R2 was deregulated in early DCM. Adiponectin mRNA and protein downregulation were confirmed in explanted hearts of patients with advanced DCM (LVEF < 25%, n= 8). In vitro, adiponectin incubation of neonatal rat ventricular myocytes led to activation of the pro-survival kinase PKB/Akt, increased eNOS-phosphorylation, and prevented stress-induced apoptosis of cardiomyocytes in an Akt-dependent manner. Moreover, inhibition of adiponectin secretion was accompanied by an increase in the expression of the cytokine and its receptors. These data indicate the existence of a local cardiac adiponectin system regulated independent of adiponectin and TNFalpha serum levels and its disturbance in cardiac pathology. The study suggests a role for adiponectin in the pathogenesis of DCM and implicates the adipocytokine as a possible future therapeutic target in DCM.

Claudin-1 promotes TNF-α-induced epithelial-mesenchymal transition and migration in colorectal adenocarcinoma cells

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

Bhat, Ajaz A.; Ahmad, Rizwan; Uppada, SrijayaPrakash B.

Epithelial-mesenchymal transition (EMT) is an important mechanism in cancer progression and malignancy including colorectal cancer (CRC). Importantly, inflammatory mediators are critical constituents of the local tumor environment and an intimate link between CRC progression and inflammation is now validated. We and others have reported key role of the deregulated claudin-1 expression in colon carcinogenesis including colitis-associated colon cancer (CAC). However, the causal association between claudin-1 expression and inflammation-induced colon cancer progression remains unclear. Here we demonstrate, TNF-α, a pro-inflammatory cytokine, regulates claudin-1 to modulate epithelial to mesenchymal transition (EMT) and migration in colon adenocarcinoma cells. Importantly, colon cancer cells culturedmore » in the presence of TNF-α (10 ng/ml), demonstrated a sharp decrease in E-cadherin expression and an increase in vimentin expression (versus control cells). Interestingly, TNF-α treatment also upregulated (and delocalized) claudin-1 expression in a time-dependent manner accompanied by increase in proliferation and wound healing. Furthermore, similar to our previous observation that claudin-1 overexpression in CRC cells induces ERK1/2 and Src- activation, signaling associated with colon cancer cell survival and transformation, TNF-α-treatment induced upregulation of phospho-ERK1/2 and -Src expression. The shRNA-mediated inhibition of claudin-1 expression largely abrogated the TNF-α-induced changes in EMT, proliferation, migration, p-Erk and p-Src expression. Taken together, our data demonstrate TNF-α mediated regulation of claudin-1 and tumorigenic abilities of colon cancer cells and highlights a key role of deregulated claudin-1 expression in inflammation-induced colorectal cancer growth and progression, through the regulation of the ERK and Src-signaling.« less

Altered metabolic pathways in clear cell renal cell carcinoma: A meta-analysis and validation study focused on the deregulated genes and their associated networks

PubMed Central

Zaravinos, Apostolos; Pieri, Myrtani; Mourmouras, Nikos; Anastasiadou, Natassa; Zouvani, Ioanna; Delakas, Dimitris; Deltas, Constantinos

2014-01-01

Clear cell renal cell carcinoma (ccRCC) is the predominant subtype of renal cell carcinoma (RCC). It is one of the most therapy-resistant carcinomas, responding very poorly or not at all to radiotherapy, hormonal therapy and chemotherapy. A more comprehensive understanding of the deregulated pathways in ccRCC can lead to the development of new therapies and prognostic markers. We performed a meta- analysis of 5 publicly available gene expression datasets and identified a list of co- deregulated genes, for which we performed extensive bioinformatic analysis coupled with experimental validation on the mRNA level. Gene ontology enrichment showed that many proteins are involved in response to hypoxia/oxygen levels and positive regulation of the VEGFR signaling pathway. KEGG analysis revealed that metabolic pathways are mostly altered in ccRCC. Similarly, Ingenuity Pathway Analysis showed that the antigen presentation, inositol metabolism, pentose phosphate, glycolysis/gluconeogenesis and fructose/mannose metabolism pathways are altered in the disease. Cellular growth, proliferation and carbohydrate metabolism, were among the top molecular and cellular functions of the co-deregulated genes. qRT-PCR validated the deregulated expression of several genes in Caki-2 and ACHN cell lines and in a cohort of ccRCC tissues. NNMT and NR3C1 increased expression was evident in ccRCC biopsies from patients using immunohistochemistry. ROC curves evaluated the diagnostic performance of the top deregulated genes in each dataset. We show that metabolic pathways are mostly deregulated in ccRCC and we highlight those being most responsible in its formation. We suggest that these genes are candidate predictive markers of the disease. PMID:25594006

Optical diagnostics in gas turbine combustors

NASA Astrophysics Data System (ADS)

Woodruff, Steven D.

1999-01-01

Deregulation of the power industry and increasingly tight emission controls are pushing gas turbine manufacturers to develop engines operating at high pressure for efficiency and lean fuel mixtures to control NOx. This combination also gives rise to combustion instabilities which threaten engine integrity through acoustic pressure oscillations and flashback. High speed imaging and OH emission sensors have been demonstrated to be invaluable tools in characterizing and monitoring unstable combustion processes. Asynchronous imaging technique permit detailed viewing of cyclic flame structure in an acoustic environment which may be modeled or utilized in burner design . The response of the flame front to the acoustic pressure cycle may be tracked with an OH emission monitor using a sapphire light pipe for optical access. The OH optical emission can be correlated to pressure sensor data for better understanding of the acoustical coupling of the flame. Active control f the combustion cycle can be implemented using an OH emission sensor for feedback.

Rubusuaviins A-F, monomeric and oligomeric ellagitannins from Chinese sweet tea and their alpha-amylase inhibitory activity.

PubMed

Li, Haizhou; Tanaka, Takashi; Zhang, Ying-Jun; Yang, Chong-Ren; Kouno, Isao

2007-09-01

Six new ellagitannins herein, rubusuaviins A-F, were isolated from the aqueous acetone extract of Chinese sweet tea (Tien-cha, dried leaves of Rubus suavissimus S. LEE) together with seven known tannins. Rubusuaviin A was characterized as 1-O-galloyl-2,3-O-(S)-HHDP-4,6-O-(S)-sanguisorboyl-beta-D-glucopyranose. Rubusuaviins B, C, and E are dimeric, trimeric, and tetrameric ellagitannins, respectively, in which the sanguisorboyl groups were connected ellagitannin units. Rubusuaviins D and F were desgalloyl derivatives of rubusuaviins C and E, respectively. The inhibition of alpha-amylase activity by rubusuaviins and related ellagitannins was compared. Ellagitannins with beta-galloyl groups at the glucose C-1 positions showed stronger inhibition compared with the alpha-galloyl and desgalloyl compounds. The molecular weight of these compounds was not important for the inhibition of alpha-amylase activity.