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1

Docosahexaenoic acid induces the degradation of HPV E6/E7 oncoproteins by activating the ubiquitin-proteasome system.  

PubMed

The oncogenic human papillomavirus (HPV) E6/E7 proteins are essential for the onset and maintenance of HPV-associated malignancies. Here, we report that activation of the cellular ubiquitin-proteasome system (UPS) by the omega-3 fatty acid, docosahexaenoic acid (DHA), leads to proteasome-mediated degradation of E6/E7 viral proteins and the induction of apoptosis in HPV-infected cancer cells. The increases in UPS activity and degradation of E6/E7 oncoproteins were associated with DHA-induced overproduction of mitochondrial reactive oxygen species (ROS). Exogenous oxidative stress and pharmacological induction of mitochondrial ROS showed effects similar to those of DHA, and inhibition of ROS production abolished UPS activation, E6/E7 viral protein destabilization, and apoptosis. These findings identify a novel role for DHA in the regulation of UPS and viral proteins, and provide evidence for the use of DHA as a mechanistically unique anticancer agent for the chemoprevention and treatment of HPV-associated tumors. PMID:25393480

Jing, K; Shin, S; Jeong, S; Kim, S; Song, K-S; Park, J-H; Heo, J-Y; Seo, K-S; Park, S-K; Kweon, G-R; Wu, T; Park, J-I; Lim, K

2014-01-01

2

The Human Papillomavirus E7 Oncoprotein  

PubMed Central

The human papillomavirus (HPV) E7 oncoprotein shares functional similarities with such proteins as adenovirus E1A and SV40 large tumor antigen. As one of only two viral proteins always expressed in HPV-associated cancers, E7 plays a central role in both the viral life cycle and carcinogenic transformation. In the HPV viral life cycle, E7 disrupts the intimate association between cellular differentiation and proliferation in normal epithelium, allowing for viral replication in cells that would no longer be in the dividing population. This function is directly reflected in the transforming activities of E7, including tumor initiation and induction of genomic instability. PMID:19007963

McLaughlin-Drubin, Margaret E.; Münger, Karl

2009-01-01

3

The Human papillomavirus type 16 E7 oncoprotein induces a transcriptional repressor complex on the Toll-like receptor 9 promoter  

PubMed Central

Human papillomavirus type 16 (HPV16) and other oncogenic viruses have been reported to deregulate immunity by suppressing the function of the double-stranded DNA innate sensor TLR9. However, the mechanisms leading to these events remain to be elucidated. We show that infection of human epithelial cells with HPV16 promotes the formation of an inhibitory transcriptional complex containing NF-?Bp50–p65 and ER? induced by the E7 oncoprotein. The E7-mediated transcriptional complex also recruited the histone demethylase JARID1B and histone deacetylase HDAC1. The entire complex bound to a specific region on the TLR9 promoter, which resulted in decreased methylation and acetylation of histones upstream of the TLR9 transcriptional start site. The involvement of NF-?B and ER? in the TLR9 down-regulation by HPV16 E7 was fully confirmed in cervical tissues from human patients. Importantly, we present evidence that the HPV16-induced TLR9 down-regulation affects the interferon response which negatively regulates viral infection. Our studies highlight a novel HPV16-mediated mechanism that combines epigenetic and transcriptional events to suppress a key innate immune sensor. PMID:23752229

Zannetti, Claudia; Parroche, Peggy; Goutagny, Nadège; Malfroy, Marine; Roblot, Guillaume; Carreira, Christine; Hussain, Ishraq; Müller, Martin; Taylor-Papadimitriou, Joyce; Picard, Didier; Sylla, Bakary S.; Trinchieri, Giorgio; Medzhitov, Ruslan

2013-01-01

4

E7 Oncoprotein of Novel Human Papillomavirus Type 108 Lacking the E6 Gene Induces Dysplasia in Organotypic Keratinocyte Cultures ?  

PubMed Central

The genome organization of the novel human papillomavirus type 108 (HPV108), isolated from a low-grade cervical lesion, deviates from those of other HPVs in lacking an E6 gene. The three related HPV types HPV103, HPV108, and HPV101 were isolated from cervicovaginal cells taken from normal genital mucosa (HPV103) and low-grade (HPV108) and high-grade cervical (HPV101) intraepithelial neoplasia (Z. Chen, M. Schiffman, R. Herrero, R. DeSalle, and R. D. Burk, Virology 360:447-453, 2007, and this report). Their unusual genome organization, against the background of considerable phylogenetic distance from the other HPV types usually associated with lesions of the genital tract, prompted us to investigate whether HPV108 E7 per se is sufficient to induce the above-mentioned clinical lesions. Expression of HPV108 E7 in organotypic keratinocyte cultures increases proliferation and apoptosis, focal nuclear polymorphism, and polychromasia. This is associated with irregular intra- and extracellular lipid accumulation and loss of the epithelial barrier. These alterations are linked to HPV108 E7 binding to pRb and inducing its decrease, an increase in PCNA expression, and BrdU incorporation, as well as increased p53 and p21CIP1 protein levels. A delay in keratin K10 expression, increased expression of keratins K14 and K16, and loss of the corneal proteins involucrin and loricrin have also been noted. These modifications are suggestive of infection by a high-risk papillomavirus. PMID:19153227

Nobre, Rui Jorge; Herráez-Hernández, Elsa; Fei, Jian-Wei; Langbein, Lutz; Kaden, Sylvia; Gröne, Hermann-Josef; de Villiers, Ethel-Michele

2009-01-01

5

Human papillomavirus E7 oncoprotein induces KDM6A and KDM6B histone demethylase expression and causes epigenetic reprogramming.  

PubMed

Despite the availability of vaccines, human papillomavirus (HPV) infections remain a cause of significant cancer morbidity and mortality. We have previously shown that HPV16 E7 associates with and diminishes E2F6-containing polycomb repressive complexes. Here, we show that repressive trimethyl marks on lysine 27 of histone 3, which are necessary for binding of polycomb repressive complexes, are decreased in HPV16 E7-expressing cells and HPV16-positive cervical lesions. This is caused by transcriptional induction of the KDM6A and KDM6B histone 3 lysine 27-specific demethylases. HPV16 E7-mediated KDM6B induction accounts for expression of the cervical cancer biomarker, p16(INK4A). Moreover, KDM6A- and KDM6B-responsive Homeobox genes are expressed at significantly higher levels, suggesting that HPV16 E7 results in reprogramming of host epithelial cells. These effects are independent of the ability of E7 to inhibit the retinoblastoma tumor suppressor protein. Most importantly, these effects are reversed when E7 expression is silenced, indicating that this pathway may have prognostic and/or therapeutic significance. PMID:21245294

McLaughlin-Drubin, Margaret E; Crum, Christopher P; Münger, Karl

2011-02-01

6

Oncoprotein E7 from beta human papillomavirus 38 induces formation of an inhibitory complex for a subset of p53-regulated promoters.  

PubMed

Our previous studies on cutaneous beta human papillomavirus 38 (HPV38) E6 and E7 oncoproteins highlighted a novel activity of I?B kinase beta (IKK?) in the nucleus of human keratinocytes, where it phosphorylates and stabilizes ?Np73?, an antagonist of p53/p73 functions. Here, we further characterize the role of the IKK? nuclear form. We show that IKK? nuclear translocation and ?Np73? accumulation are mediated mainly by HPV38 E7 oncoprotein. Chromatin immunoprecipitation (ChIP)/Re-ChIP experiments showed that ?Np73? and IKK? are part, together with two epigenetic enzymes DNA methyltransferase 1 (DNMT1) and the enhancer of zeste homolog 2 (EZH2), of a transcriptional regulatory complex that inhibits the expression of some p53-regulated genes, such as PIG3. Recruitment to the PIG3 promoter of EZH2 and DNMT1 resulted in trimethylation of histone 3 on lysine 27 and in DNA methylation, respectively, both events associated with gene expression silencing. Decreases in the intracellular levels of HPV38 E7 or ?Np73? strongly affected the recruitment of the inhibitory transcriptional complex to the PIG3 promoter, with consequent restoration of p53-regulated gene expression. Finally, the ?Np73?/IKK?/DNMT1/EZH2 complex appears to bind a subset of p53-regulated promoters. In fact, the complex is efficiently recruited to several promoters of genes encoding proteins involved in DNA repair and apoptosis, whereas it does not influence the expression of the prosurvival factor Survivin. In summary, our data show that HPV38 via E7 protein promotes the formation of a multiprotein complex that negatively regulates the expression of several p53-regulated genes. PMID:24006445

Saidj, Djamel; Cros, Marie-Pierre; Hernandez-Vargas, Hector; Guarino, Francesca; Sylla, Bakary S; Tommasino, Massimo; Accardi, Rosita

2013-11-01

7

Differential Regulation of the Pocket Domains of the Retinoblastoma Family Proteins by the HPVI6 E7 Oncoprotein1  

Microsoft Academic Search

The human papillomavirus E7 oncoprotein binds to the retinoblastoma (Rb) tumor suppressor protein, and the binding to Rb correlates with the oncogenic potential of E7. Recent studies from several laboratories indicated that the half-life of the Rb protein is reduced in cells that are stably transformed with E7, suggesting that E7 could induce the proteolytic degradation of Rb. To investigate

Ekaterena Berezutskaya; Bo Yu; Alexei Morozov; Pradip Raychaudhuri; Srilata Bagchi

1997-01-01

8

HPV E7 Viral Oncoprotein Disrupts Transcriptional Regulation of L1Md Retrotransposon  

PubMed Central

Murine L1Md-A5 retrotransposon is a redox-inducible element regulated by Nrf-2/JunD and E2F/Rb-binding sites within its promoter (5?-UTR). Because the human papillomavirus (HPV) oncoprotein E7 interacts with retinoblastoma (pRb) and members of the AP1 family, studies were conducted to examine functional interactions between HPV E7, pRb, and histone deacetylase 2 (HDAC2) in the regulation of L1Md-A5. Using a transient heterologous transcription system we found that HPV E7 alone, or in combination with HDAC2, disrupted pRb-mediated L1MdA-5 transactivation. HPV E7 also ablated the transcriptional response of L1Md-A5 to genotoxic stress, but did not interfere with basal activity. We conclude that HPV E7 associates with proteins involved in the assembly of macromolecular complexes that regulate antioxidant and E2F/Rb sites within L1MdA-5 to regulate biological activity PMID:22172279

Montoya-Durango, Diego E.; Ramos, Kenneth S.

2012-01-01

9

Nuclear export of cutaneous HPV8 E7 oncoprotein is mediated by a leucine-rich nuclear export signal via a CRM1 pathway.  

PubMed

We recently determined that the nuclear import of cutaneous beta genus HPV8 E7 oncoprotein it is mediated by its zinc-binding domain via direct hydrophobic interactions with the FG nucleoporins Nup62 and Nup153 (Onder and Moroianu, 2014). Here we investigated the nuclear export of HPV8 E7 oncoprotein using confocal microscopy after transfections of HeLa cells with EGFP-8cE7 and mutant plasmids and treatment with Ratjadone A nuclear export inhibitor. We determined that HPV8 E7 contains a leucine-rich nuclear export signal (NES), 76IRTFQELLF84, within its zinc-binding domain that mediates its nuclear export via a CRM1 pathway. We found that HPV8 E7 interacts with CRM1 and that the hydrophobic amino acid residues I76, F79 and L82 of the NES are essential for this interaction and for nuclear export of HPV8 E7 oncoprotein. PMID:25463601

Onder, Zeynep; Chang, Vivian; Moroianu, Junona

2015-01-01

10

Human Papillomavirus E7 Oncoprotein Increases Production of the Anti-Inflammatory Interleukin-18 Binding Protein in Keratinocytes  

PubMed Central

ABSTRACT Human papillomavirus (HPV) can successfully evade the host immune response to establish a persistent infection. We show here that expression of the E7 oncoprotein in primary human keratinocytes results in increased production of interleukin-18 (IL-18) binding protein (IL-18BP). This anti-inflammatory cytokine binding protein is a natural antagonist of IL-18 and is necessary for skin homeostasis. We map increased IL-18BP production to the CR3 region of E7 and demonstrate that this ability is shared among E7 proteins from different HPV types. Furthermore, mutagenesis shows that increased IL-18BP production is mediated by a gamma-activated sequence (GAS) in the IL-18BP promoter. Importantly, the increased IL-18BP levels seen in E7-expressing keratinocytes are capable of diminishing IL-18-mediated CD4 lymphocyte activation. This study provides the first evidence for a virus protein that targets IL-18BP and further validates E7 as a key component of the HPV immune evasion armor. IMPORTANCE Infection with human papillomavirus is a leading cause of morbidity and mortality worldwide. This study demonstrates that the E7 protein increases production of the anti-inflammatory IL-18BP, a major regulator of epithelial homeostasis. A number of E7 proteins can increase IL-18BP production, and a region within the CR3 of E7 is necessary for mediating the increase. A consequence of increased IL-18BP production is a reduction in CD4-positive lymphocyte activation in response to IL-18 costimulation. These findings may shed light on the immune evasion abilities of HPV. PMID:24478434

Richards, Kathryn H.; Doble, Rosella; Wasson, Christopher W.; Haider, Mohammed; Blair, G. Eric; Wittmann, Miriam

2014-01-01

11

Structure-function analysis of the human papillomavirus type 16 E7 oncoprotein.  

PubMed Central

The E7 gene of human papillomavirus type 16 encodes a multifunctional nuclear phosphoprotein that is functionally and structurally similar to the adenovirus (Ad) E1A proteins and the T antigens of other papovaviruses. E7 can cooperate with an activated ras oncogene to transform primary rodent cells, trans activate the Ad E2 promoter, and abrogate transforming growth factor beta-mediated repression of c-myc. Recent studies suggest that these functions may in part be a consequence of the ability of E7 to associate with the product of the retinoblastoma tumor suppressor gene (pRB). In this study, a series of site-specific mutations of the human papillomavirus type 16 E7 gene product were constructed and assessed for their effects on intracellular protein stability, ras cooperativity, transcriptional trans activation, pRB association, and phosphorylation. The results of these studies indicate that the transforming and trans-activating domains extensively overlap within a region of the protein analogous to conserved region 2 of Ad E1A, suggesting that pRB binding is necessary for both activities. Deletion of sequences in conserved region 1 abrogates cellular transformation but has only a marginal effect on trans activation. These data suggest that E7 trans activation and cellular transformation are interrelated but separable functions. Images PMID:1312637

Phelps, W C; Münger, K; Yee, C L; Barnes, J A; Howley, P M

1992-01-01

12

Degradation of the E7 human papillomavirus oncoprotein by the ubiquitin-proteasome system: targeting via ubiquitination of the N-terminal residue  

Microsoft Academic Search

The E7 oncoprotein of the high risk human papillomavirus type 16 (HPV-16), which is etiologically associated with uterine cervical cancer, is a potent immortalizing and transforming agent. It probably exerts its oncogenic functions by interacting and altering the normal activity of cell cycle control proteins such as p21WAF1, p27KIP1 and pRb, transcriptional activators such as TBP and AP-1, and metabolic

Eyal Reinstein; Martin Scheffner; Moshe Oren; Aaron Ciechanover; Alan Schwartz

2000-01-01

13

Human papillomavirus type 16 E7 oncoprotein inhibits the anaphase promoting complex/cyclosome activity by dysregulating EMI1 expression in mitosis.  

PubMed

The anaphase promoting complex/cyclosome (APC/C) is a ubiquitin ligase complex that orchestrates mitotic progression by targeting key mitotic regulators for proteasomal degradation. APC/C dysfunction is a frequent event during cancer development and can give rise to genomic instability. Here we report that the HPV16 E7 oncoprotein interferes with the degradation of APC/C substrates and that the APC/C inhibitor, EMI1, is expressed at higher levels in HPV16 E7-expressing mitotic cells. HPV16 E7 expression causes increased EMI1 mRNA expression and also inhibits EMI1 degradation. The resulting abnormally high EMI1 levels in HPV16 E7-expressing mitotic cells may inhibit degradation of APC/C substrates and cause the prometaphase delay that we have previously observed in such cells. PMID:24074588

Yu, Yueyang; Munger, Karl

2013-11-01

14

The High-Risk HPV16 E7 Oncoprotein Mediates Interaction between the Transcriptional Coactivator CBP and the Retinoblastoma Protein pRb.  

PubMed

The oncoprotein E7 from human papillomavirus (HPV) strains that confer high cancer risk mediates cell transformation by deregulating host cellular processes and activating viral gene expression through recruitment of cellular proteins such as the retinoblastoma protein (pRb) and the cyclic-AMP response element binding binding protein (CBP) and its paralog p300. Here we show that the intrinsically disordered N-terminal region of E7 from high-risk HPV16 binds the TAZ2 domain of CBP with greater affinity than E7 from low-risk HPV6b. HPV E7 and the tumor suppressor p53 compete for binding to TAZ2. The TAZ2 binding site in E7 overlaps the LxCxE motif that is crucial for interaction with pRb. While TAZ2 and pRb compete for binding to a monomeric E7 polypeptide, the full-length E7 dimer mediates an interaction between TAZ2 and pRb by promoting formation of a ternary complex. Cell-based assays show that expression of full-length HPV16 E7 promotes increased pRb acetylation and that this response depends both on the presence of CBP/p300 and on the ability of E7 to form a dimer. These observations suggest a model for the oncogenic effect of high-risk HPV16 E7. The disordered region of one E7 molecule in the homodimer interacts with the pocket domain of pRb, while the same region of the other E7 molecule binds the TAZ2 domain of CBP/p300. Through its ability to dimerize, E7 recruits CBP/p300 and pRb into a ternary complex, bringing the histone acetyltransferase domain of CBP/p300 into proximity to pRb and promoting acetylation, leading to disruption of cell cycle control. PMID:25451029

Jansma, Ariane L; Martinez-Yamout, Maria A; Liao, Rong; Sun, Peiqing; Dyson, H Jane; Wright, Peter E

2014-12-12

15

SOC1 inhibits HPV-E7-mediated transformation by inducing degradation of E7 protein  

Microsoft Academic Search

Human papilloma viruses (HPVs) are small double-stranded DNA viruses that infect mucosal and cutaneous epithelium and induce cervical cancer. It has been shown that interferon (IFN)? suppresses proliferation of HPV-infected cells by suppressing expression of HPV E7. Here, we found that IFN? induces not only suppression of E7 transcription but also proteasome-dependent degradation. Suppressor of cytokine signaling-1 (SOCS1)\\/JAB, a suppressor

Masaki Kamio; Takafumi Yoshida; Hisanobu Ogata; Tsutomu Douchi; Yukihiro Nagata; Makoto Inoue; Mamoru Hasegawa; Yoshikazu Yonemitsu; Akihiko Yoshimura

2004-01-01

16

PP1 Inhibitor Induces Degradation of RETMEN2A and RETMEN2B Oncoproteins through Proteosomal Targeting1  

Microsoft Academic Search

RET tyrosine kinase oncoproteins are potential targets for anticancer therapy. We show here that along with the inhibition of RET tyrosine phosphorylation, the pyrazolo-pyrimidine inhibitor PP1 induces RETMEN2A and RETMEN2B oncoprotein destruction. In fact, as a consequence of PP1 treatment, RET oncoproteins translocate from the outer limiting membrane to inner cellular compartments and are rapidly addressed to the degradative pathway.

Cristiana Carniti; Carla Perego; Piera Mondellini; Marco Alessandro Pierotti; Italia Bongarzone

2003-01-01

17

Human papillomavirus e7 oncoprotein transgenic skin develops an enhanced inflammatory response to 2,4-dinitrochlorobenzene by an arginase-1-dependent mechanism.  

PubMed

We have shown that the expression of human papillomavirus type 16 E7 (HPV16.E7) protein within epithelial cells results in local immune suppression and a weak and ineffective immune response to E7 similar to that occuring in HPV-associated premalignancy and cancers. However, a robust acute inflammatory stimulus can overcome this to enable immune elimination of HPV16.E7-transformed epithelial cells. 2,4-Dinitrochlorobenzene (DNCB) can elicit acute inflammation and it has been shown to initiate the regression of HPV-associated genital warts. Although the clinical use of DNCB is discouraged owing to its mutagenic potential, understanding how DNCB-induced acute inflammation alters local HPV16.E7-mediated immune suppression might lead to better treatments. Here, we show that topical DNCB application to skin expressing HPV16.E7 as a transgene induces a hyperinflammatory response, which is not seen in nontransgenic control animals. The E7-associated inflammatory response is characterized by enhanced expression of Th2 cytokines and increased infiltration of CD11b(+)Gr1(int)F4/80(+)Ly6C(hi)Ly6G(low) myeloid cells, producing arginase-1. Inhibition of arginase with an arginase-specific inhibitor, N(omega)-hydroxy-nor-L-arginine, ameliorates the DNCB-induced inflammatory response. Our results demonstrate that HPV16.E7 protein enhances DNCB-associated production of arginase-1 by myeloid cells and consequent inflammatory cellular infiltration of skin. PMID:24732401

Tran, Le Son; Bergot, Anne-Sophie; Mattarollo, Stephen R; Mittal, Deepak; Frazer, Ian H

2014-09-01

18

Construction and characterization of recombinant fowlpox viruses expressing human papilloma virus E6 and E7 oncoproteins  

Microsoft Academic Search

Human papilloma virus (HPV)-16 is the most prevalent high-risk mucosal genotype and the expression of the E6 and E7 proteins, which can bind to the p53 and p105Rb host cell-cycle regulatory proteins, is related to its tumorigenicity. Virus-like-particle (VLP)-based immunogens developed recently are successful as prophylactic HPV vaccines. However, given the high number of individuals infected already with HPV and

Eleana Pozzi; Valeria Basavecchia; Carlo Zanotto; Sole Pacchioni; Carlo De Giuli Morghen; Antonia Radaelli

2009-01-01

19

Oncoprotein Akt/PKB induces trophic effects in murine models of Parkinson's disease  

E-print Network

Oncoprotein Akt/PKB induces trophic effects in murine models of Parkinson's disease Vincent Ries an established role in the treatment of human neurodegenerative diseases. One impediment has been the diffi, neurons affected in Parkinson's disease, by adeno-associated virus 1 trans- duction with a gene encoding

Burke, Robert E

20

Chemo-radio Resistance in Cervical Cancer Induced by HPV16 E7  

Microsoft Academic Search

Alteration of the apoptosis pathway, as well as the presence of human papilloma virus (HPV), has been linked to the proliferative capacity and drug resistant phenotype of SiHa cervical cancer. We investigated the roles of E6 and E7 HPV oncoproteins in the expression of apoptosis regulating genes in cervical cancer cells that contain the characteristics of apoptosis resistance, and also

Saharat Aungsumart

21

Different regions of the HPV-E7 and Ad-E1A viral oncoproteins bind competitively but through distinct mechanisms to the CH1 transactivation domain of p300.  

PubMed

p300 is a transcriptional coactivator that participates in many important processes in the cell, including proliferation, differentiation, and apoptosis. The viral oncoproteins, adenovirus (Ad) E1A and human papillomavirus (HPV) E7, have been implicated in binding to p300. The Ad-E1A-p300 interaction has been shown to result in the induction of cellular proliferation, epigenetic reprogramming, and cellular transformation and cancer. The HPV-E7-p300 interaction, on the other hand, is not well understood. p300 contains three zinc-binding domains, CH1-CH3, and studies have shown that Ad-E1A can bind to the p300 CH1 and CH3 domains whereas E7 can bind to the CH1 domain and to a lesser extent to the CH2 and CH3 domains. Here we address how high-risk HPV16-E7 and Ad5-E1A, which have different structures, can both bind the p300 CH1 domain. Using pull-down, gel filtration, and analytical ultracentrifugation studies, we show that the N-terminus and CR1 domains of Ad5-E1A and the CR1 and CR2 domains of HPV16-E7 bind to the p300 CH1 domain competitively and with midnanomolar and low micromolar dissociation constants, respectively. We also show that Ad5-E1A can form a ternary complex with the p300 CH1 domain and the retinoblastoma pRb transcriptional repressor, whereas HPV16-E7 cannot. These studies suggest that the HPV16-E7 and Ad5-E1A viral oncoproteins bind to the same p300 CH1 domain to disrupt p300 function by distinct mechanisms. PMID:23121466

Fera, Daniela; Marmorstein, Ronen

2012-11-27

22

Analysis of the p53-mediated G1 growth arrest pathway in cells expressing the human papillomavirus type 16 E7 oncoprotein.  

PubMed Central

Cells expressing human papillomavirus type 16 (HPV-16) E7, similar to those which express HPV-16 E6, are resistant to a p53-mediated G1 growth arrest. We examined the p53-mediated DNA damage response pathway in E7-expressing cells to determine the mechanism by which E7-containing cells continue to cycle. In response to DNA damage, no dramatic difference was detected in G1- or S-phase cyclin or cyclin-dependent kinase (Cdk) levels when E7-expressing cells were compared to the parental cell line, RKO. Furthermore, Cdk2 kinase activity was inhibited in both RKO cells and E7-expressing cells, while Cdk2 remained active in E6-expressing cells. However, the steady-state levels of pRB and p107 protein were substantially lower in E7-expressing cells than in the parental RKO cells or E6-expressing cells. There was no reduction in pRB mRNA levels, but the half-life of pRB in E7-expressing cells was markedly shorter. Infection of primary human foreskin keratinocytes with recombinant retroviruses expressing HPV-16 E7 resulted in a decrease in pRB protein levels, indicating this phenomenon is a consequence of E7 expression, not of immortalization or transformation. These data strongly suggest E7 interferes with the stability of pRB and p107 protein. We propose that the removal of these components of the p53-mediated G1 growth arrest pathway in E7-expressing cells contributes to the ability of E7 to overcome a p53-mediated G1 growth arrest. PMID:9060648

Jones, D L; Münger, K

1997-01-01

23

Berberine alters epigenetic modifications, disrupts microtubule network, and modulates HPV-18 E6-E7 oncoproteins by targeting p53 in cervical cancer cell HeLa: A mechanistic study including molecular docking.  

PubMed

Increased evidence of chemo-resistance, toxicity and carcinogenicity necessitates search for alternative approaches for determining next generation cancer therapeutics and targets. We therefore tested the efficacy of plant alkaloid berberine on human papilloma virus (HPV) -18 positive cervical cancer cell HeLa systematically-involving certain cellular, viral and epigenetic factors. We observed disruptions of microtubule network and changes in membrane topology due to berberine influx through confocal and atomic force microscopies (AFM). We examined nuclear uptake, internucleosomal DNA damages, mitochondrial membrane potential (MMP) alterations and cell migration assays to validate possible mode of cell death events. Analytical data on interactions of berberine with pBR322 through fourier transform infrared (FTIR) and gel migration assay strengthen berberine?s biologically significant DNA binding abilities. We measured cellular uptake, DNA ploidy and DNA strand-breaks through fluorescence activated cell sorting (FACS). To elucidate epigenetic modifications, in support of DNA binding associated processes, if any, we conducted methylation-specific restriction enzyme (RE) assay, methylation specific-PCR (MSP) and expression studies of histone proteins. We also analyzed differential interactions and localization of cellular tumor suppressor p53 and viral oncoproteins HPV-18 E6-E7 through siRNA approach. We further made in-silico approaches to determine possible binding sites of berberine on histone proteins. Overall results indicated cellular uptake of berberine through cell membrane depolarization causing disruption of microtubule networks and its biological DNA binding abilities that probably contributed to epigenetic modifications. Results of modulation in p53 and viral oncoproteins HPV-18 E6-E7 by berberine further proved its potential as a promising chemotherapeutic agent in cervical cancer. PMID:25448308

Saha, Santu Kumar; Khuda-Bukhsh, Anisur Rahman

2014-12-01

24

Expression of the HPV16E7 Oncoprotein by Thymic Epithelium is Accompanied by Disrupted T Cell Maturation and a Failure of the Thymus to Involute with Age  

PubMed Central

Transgenic mice expressing the E7 protein of HPV16 from the keratin 14 promoter demonstrate increasing thymic hypertrophy with age. This hypertrophy is associated with increased absolute numbers of all thymocyte types, and with increased cortical and medullary cellularity. In the thymic medulla, increased compartmentalization of the major thymic stromal cell types and expansion of thymic epithelial cell population is observed. Neither an increased rate of immature thymocyte division nor a decreased rate of immature thymocyte death was able to account for the observed hypertrophy. Thymocytes with reduced levels of expression of CD4 and/or CD8 were more abundant in transgenic (tg) mice and became increasingly more so with age. These thymic SP and DP populations with reduced levels of CD4 and/or CD8 markers had a lower rate of apoptosis in the tg than in the non-tg mice. The rate of export of mature thymocytes to peripheral lymphoid organs was less in tg animals relative to the pool of available mature cells, particularly for the increasingly abundant CD4lo population. We therefore suggest that mature thymocytes that would normally die in the thymus gradually accumulated in E7 transgenic animals, perhaps as a consequence of exposure to a hypertrophied E7-expressing thymic epithelium or to factors secreted by this expanded thymic stromal cell population. The K14E7 transgenic mouse thus provides a unique model to study effects of the thymic epithelial cell compartment on thymus development and involution. PMID:14768939

Malcolm, K. M.; Gill, J.; Leggatt, G. R.; Boyd, R.; Lambert, P.; Frazer, I. H.

2003-01-01

25

Transcriptional regulation of genes involved in keratinocyte differentiation by human papillomavirus 16 oncoproteins.  

PubMed

The life cycle of human papillomaviruses (HPVs) is strictly linked to the differentiation of their natural host cells. The HPV E6 and E7 oncoproteins can delay the normal differentiation program of keratinocytes; however, the exact mechanisms responsible for this have not yet been identified. The goal of this study was to investigate the effects of HPV16 oncoproteins on the expression of genes involved in keratinocyte differentiation. Primary human keratinocytes transduced by LXSN (control) retroviruses or virus vectors expressing HPV16 E6, E7 or E6/E7 genes were subjected to gene expression profiling. The results of microarray analysis showed that HPV 16 E6 and E7 have the capacity to downregulate the expression of several genes involved in keratinocyte differentiation. Quantitative real-time polymerase chain reaction (qRT-PCR) assays were performed to confirm the microarray data. To investigate the effects of the HPV oncoproteins on the promoters of selected keratinocyte differentiation genes, luciferase reporter assays were performed. Our results suggest that the HPV 16 E6 and/or E7 oncogenes are able to downregulate the expression of several genes involved in keratinocyte differentiation (such as desmocollin 1, keratin 4, S100 calcium-binding protein A8 and small proline-rich protein 1A), at least partially by downregulating their promoter activity. This activity of the HPV oncoproteins may have a role in the productive virus life cycle, and also in virus-induced carcinogenesis. PMID:25488293

Gyöngyösi, Eszter; Szalmás, Anita; Ferenczi, Annamária; Póliska, Szilárd; Kónya, József; Veress, György

2014-12-01

26

The HPV-16 E7 oncogene sensitizes malignant cells to IFN-alpha-induced apoptosis  

SciTech Connect

Interferons (IFNs) exert antitumor effects in several human malignancies, but their mechanism of action is unclear. There is a great variability in sensitivity to IFN treatment depending on both tumor type and the individual patient. The reason for this variable sensitivity is not known. The fact that several IFN-induced anticellular effects are exerted through modulation of proto-oncogenes and tumor suppressor genes may indicate that the malignant genotype may be decisive in the cell's sensitivity to IFN. To determine if a deregulated oncogene could alter the cellular response to IFN, a mouse lymphoma cell line (J3D) was stably transfected with the viral human papillomavirus-16 (HPV-16) E7 oncogene. The E7-transfected cells and their respective mock-transfected sister clones were treated with IFN-{alpha} and examined for possible IFN-induced anticellular effects. We found that the E7-transfected clones were greatly sensitized to IFN-{alpha}-induced apoptosis compared with their mock-transfected counterparts. Induction of apoptosis in the transfected cells correlated with the ability of IFN to activate parts of the proapoptotic machinery specifically in these cells, including activation of caspases and the proapoptotic protein Bak. In summary, our data suggest that transfection of malignant cells with the E7 oncogene can sensitize them to IFN-{alpha}-induced apoptosis. This demonstrates that an oncogenic event may alter the cellular sensitivity to IFN and might also have implications for treatment of HPV related diseases with IFN.

Wang, Yisong [ORNL

2005-10-01

27

Splicing-factor oncoprotein SRSF1 stabilizes p53 via RPL5 and induces cellular senescence  

PubMed Central

SUMMARY Splicing and translation are highly regulated steps of gene expression. Altered expression of proteins involved in these processes can be deleterious. Therefore, the cell has many safeguards against such misregulation. We report that the oncogenic splicing factor SRSF1, which is overexpressed in many cancers, stabilizes the tumor-suppressor protein p53 by abrogating its MDM2-dependent proteasomal degradation. We show that SRSF1 is a necessary component of an MDM2/ribosomal-protein complex—separate from the ribosome—that functions in a p53-dependent ribosomal-stress checkpoint pathway. Consistent with the stabilization of p53, increased SRSF1 expression in primary human fibroblasts decreases cellular proliferation and ultimately triggers oncogene-induced senescence (OIS). These findings underscore the deleterious outcome of SRSF1 overexpression and identify a cellular defense mechanism against its aberrant function. Furthermore, they implicate the RPL5-MDM2 complex in OIS, and demonstrate a link between spliceosomal and ribosomal components—functioning independently of their canonical roles—to monitor cellular physiology and cell-cycle progression. PMID:23478443

Fregoso, Oliver I.; Das, Shipra; Akerman, Martin; Krainer, Adrian R.

2013-01-01

28

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

Microsoft Academic Search

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

Tonia Buonomo; Laura Carraresi; Mara Rossini; Rosanna Martinelli

2011-01-01

29

HPV E7 contributes to the telomerase activity of immortalized and tumorigenic cells and augments E6-induced hTERT promoter function  

PubMed Central

The E6 and E7 proteins of high-risk HPVs are both required for the immortalization of primary human keratinocytes and the maintenance of the malignant phenotype of HPV-positive cancer cell lines. Our previous studies have shown that E6 protein binds Myc protein and that both E6 and Myc associate with and cooperatively activate the hTERT promoter, thereby increasing cellular telomerase activity. In this study, we evaluated the role of E7 in the maintenance and activation of telomerase in immortalized and tumorigenic cells. siRNA knockdown of either E6 or E7 (or both) in HPV-immortalized cells or an HPV-positive cancer cell line reduced hTERT transcription and telomerase activity. Since telomerase was inhibited by E7 siRNA in cells that independently expressed the E6 and E7 genes, our results reveal an independent role for E7 in the maintenance of telomerase activity. However, E7 alone was insufficient to increase endogenous hTERT mRNA or telomerase activity, although it significantly augmented E6-induced hTERT transcription and telomerase activity. To further explore this apparent E7-induced promoter augmentation, we analyzed an exogenous hTERT core promoter in transduced keratinocytes. E7 alone induced the wt hTERT promoter and augmented E6-induced hTERT promoter activity. Mutation of the E2F site in the hTERT promoter abrogated the ability of E7 to induce the hTERT promoter or to enhance the ability of E6 to induce the promoter. Correspondingly, keratinocytes expressing E6 and a mutant E7 (defective for binding pRb pocket proteins) showed lower telomerase activity than cells expressing wt E6 and wt E7. Thus, HPV E7 plays a role in the maintenance of telomerase activity in stable cell lines and augments acute, E6-induced hTERT promoter activity. PMID:18367227

Liu, Xuefeng; Roberts, Jeffrey; Dakic, Aleksandra; Zhang, Yiyu; Schlegel, Richard

2009-01-01

30

Mechanistic Analysis of the Role of Bromodomain-containing Protein 4 (BRD4) in BRD4-NUT Oncoprotein-induced Transcriptional Activation.  

PubMed

NUT midline carcinoma (NMC) is a rare but highly aggressive cancer typically caused by the translocation t(15;19), which results in the formation of the BRD4-NUT fusion oncoprotein. Previous studies have demonstrated that fusion of the NUT protein with the double bromodomains of BRD4 may significantly alter the cellular gene expression profile to contribute to NMC tumorigenesis. However, the mechanistic details of this BRD4-NUT function remain poorly understood. In this study, we examined the NUT function in transcriptional regulation by targeting it to a LacO transgene array integrated in U2OS 2-6-3 cells, which allow us to visualize how NUT alters the in situ gene transcription dynamic. Using this system, we demonstrated that the NUT protein tethered to the LacO locus recruits p300/CREB-binding protein (CBP), induces histone hyperacetylation, and enriches BRD4 to the transgene array chromatin foci. We also discovered that, in BRD4-NUT expressed in NMC cells, the NUT moiety of the fusion protein anchored to chromatin by the double bromodomains also stimulates histone hyperacetylation, which causes BRD4 to bind tighter to chromatin. Consequently, multiple BRD4-interacting factors are recruited to the NUT-associated chromatin locus to activate in situ transgene expression. This gene transcription function was repressed by either expression of a dominant negative inhibitor of the p300-NUT interaction or treatment with (+)-JQ1, which dissociates BRD4 from the LacO chromatin locus. Our data support a model in which BRD4-NUT-stimulated histone hyperacetylation recruits additional BRD4 and interacting partners to support transcriptional activation, which underlies the BRD4-NUT oncogenic mechanism in NMC. PMID:25512383

Wang, Ranran; You, Jianxin

2015-01-30

31

Expression of Human Papillomavirus Type 16 E7 Is Sufficient to Significantly Increase Expression of Angiogenic Factors But Is Not Sufficient to Induce Endothelial Cell Migration  

PubMed Central

Tumor suppressors negatively regulate angiogenesis, an essential step in tumor progression. Together, HPV 16 E6 and E7 proteins, which target p53 and pRb family members, respectively, for degradation, increase the expression of two angiogenic inducers, VEGF and IL-8, in primary foreskin keratinocytes (HFKs). Conditioned media from such cells are sufficient to alter endothelial cell behavior. Here, the individual contribution of E6 and E7 to angiogenesis was investigated. E7 and, to a lesser extent E6, increased expression of VEGF and IL-8. Nevertheless, neither conditioned media from HPV 16 E6 nor E7-expressing HFKs were sufficient to induce migration of endothelial cells. Conditioned media from HFKs expressing the HPV 16 E6 and the E7 mutant E7C24G, which can target p107 and p130 but not pRb for degradation, contained increased levels of VEGF and IL-8. The results suggest that the mechanism of HPV 16 E7-mediated increased levels of VEGF is pRb-independent. PMID:21159359

Walker, Joanna; Smiley, Lucy Clare; Ingram, David; Roman, Ann

2010-01-01

32

Disruption of HPV16-E7 by CRISPR/Cas System Induces Apoptosis and Growth Inhibition in HPV16 Positive Human Cervical Cancer Cells  

PubMed Central

High-risk human papillomavirus (HR-HPV) has been recognized as a major causative agent for cervical cancer. Upon HPV infection, early genes E6 and E7 play important roles in maintaining malignant phenotype of cervical cancer cells. By using clustered regularly interspaced short palindromic repeats- (CRISPR-) associated protein system (CRISPR/Cas system), a widely used genome editing tool in many organisms, to target HPV16-E7 DNA in HPV positive cell lines, we showed for the first time that the HPV16-E7 single-guide RNA (sgRNA) guided CRISPR/Cas system could disrupt HPV16-E7 DNA at specific sites, inducing apoptosis and growth inhibition in HPV positive SiHa and Caski cells, but not in HPV negative C33A and HEK293 cells. Moreover, disruption of E7 DNA directly leads to downregulation of E7 protein and upregulation of tumor suppressor protein pRb. Therefore, our results suggest that HPV16-E7 gRNA guided CRISPR/Cas system might be used as a therapeutic strategy for the treatment of cervical cancer. PMID:25136604

Hu, Zheng; Yu, Lan; Zhu, Da; Ding, Wencheng; Wang, Xiaoli; Zhang, Changlin; Wang, Liming; Jiang, Xiaohui; Shen, Hui; He, Dan; Li, Kezhen; Xi, Ling; Ma, Ding; Wang, Hui

2014-01-01

33

Three Regions of the pRB Pocket Domain Affect Its Inactivation by Human Papillomavirus E7 Proteins  

PubMed Central

A critical event in papillomavirus transformation of human cells is the inactivation of pRB by the E7 protein. E7, like many other viral oncoproteins, possesses a well-characterized LXCXE peptide motif that interacts with the pocket domain of pRB. Disruption of the LXCXE-binding cleft on pRB renders it resistant to E7 binding and inactivation. Such binding cleft mutants of pRB are capable of inducing a G1 arrest in the human papillomavirus 18-transformed HeLa cell line. We show here that the efficient inactivation of pRB in HeLa cells does not simply depend on the integrity of the LXCXE-binding cleft. Multiple site-directed mutants that alter conserved surfaces of the pRB pocket domain cause HeLa cells to accumulate in G1. We divide these mutants into two classes: those that can be bound by E7 and those that cannot. The E7 interacting mutants include changes in conserved residues that lie in a groove between the A and B halves of the pocket. Surprisingly, none of these mutants show a clear defect in any of the known mechanisms for pRB inactivation by E7. Analysis of mutants that are compromised for E7 binding reveals that this interaction depends on both the LXCXE-binding cleft and on a conserved group of lysines adjacent to the cleft. These basic amino acids on pRB define a discrete interaction point with E7. These residues most likely form ionic interactions with conserved acidic amino acids on E7 since a stable pRB/E7 interaction was restored when the lysine residues on pRB and the acidic residues on E7 were interchanged. PMID:12021356

Dick, Frederick A.; Dyson, Nicholas J.

2002-01-01

34

Destabilization of Rb by human papillomavirus E7 is cell cycle dependent: E2-25K is involved in the proteolysis  

PubMed Central

The HPV-oncoprotein, E7 promotes proteasomal degradation of the tumor suppressor protein, Rb. In this study, we analyzed the regulation of E7-induced Rb proteolysis in HPV-containing Caski cervical cancer cells. We show that the Rb proteolysis is cell cycle dependent; in S phase Rb is stable while in post-mitotic early G1 phase cells and in differentiated cells, Rb is unstable. Similarly, the in vivo Rb/E7 interaction is not detected in S phase cells, but is readily detected in differentiating Caski cells. The ubiquitinating enzymes involved in Rb proteolysis have not been identified. We find that the E3 ligase MDM2 is not involved in the Rb proteolysis in Caski cells. An in vivo analysis using multiple catalytic-site mutant dominant negative E2-enzymes show that the C92A E2-25K most effectively blocks E7-induced Rb proteolysis. Taken together, these results show that E7 induces Rb proteolysis in growth-arrested cells and E2-25K is involved in the proteolysis. PMID:19906396

Oh, Kwang-Jin; Kalinina, Anna; Bagchi, Srilata

2009-01-01

35

Identification of unusual E6 and E7 proteins within avian papillomaviruses: cellular localization, biophysical characterization, and phylogenetic analysis.  

PubMed

Papillomaviruses (PVs) are a large family of small DNA viruses infecting mammals, reptiles, and birds. PV infection induces cell proliferation that may lead to the formation of orogenital or skin tumors. PV-induced cell proliferation has been related mainly to the expression of two small oncoproteins, E6 and E7. In mammalian PVs, E6 contains two 70-residue zinc-binding repeats, whereas E7 consists of a natively unfolded N-terminal region followed by a zinc-binding domain which folds as an obligate homodimer. Here, we show that both the novel francolin bird PV Francolinus leucoscepus PV type 1 (FlPV-1) and the chaffinch bird PV Fringilla coelebs PV contain unusual E6 and E7 proteins. The avian E7 proteins contain an extended unfolded N terminus and a zinc-binding domain of reduced size, whereas the avian E6 proteins consist of a single zinc-binding domain. A comparable single-domain E6 protein may have existed in a common ancestor of mammalian and avian PVs. Mammalian E6 C-terminal domains are phylogenetically related to those of single-domain avian E6, whereas mammalian E6 N-terminal domains seem to have emerged by duplication and subsequently diverged from the original ancestral domain. In avian and mammalian cells, both FlPV-1 E6 and FlPV-1 E7 were evenly expressed in the cytoplasm and the nucleus. Finally, samples of full-length FlPV-1 E6 and the FlPV-1 E7 C-terminal zinc-binding domain were prepared for biophysical analysis. Both constructs were highly soluble and well folded, according to nuclear magnetic resonance spectroscopy measurements. PMID:19553340

Van Doorslaer, Koenraad; Sidi, Abdellahi Ould M'hamed Ould; Zanier, Katia; Rybin, Vladimir; Deryckère, François; Rector, Annabel; Burk, Robert D; Lienau, E Kurt; van Ranst, Marc; Travé, Gilles

2009-09-01

36

Identification of Unusual E6 and E7 Proteins within Avian Papillomaviruses: Cellular Localization, Biophysical Characterization, and Phylogenetic Analysis? §  

PubMed Central

Papillomaviruses (PVs) are a large family of small DNA viruses infecting mammals, reptiles, and birds. PV infection induces cell proliferation that may lead to the formation of orogenital or skin tumors. PV-induced cell proliferation has been related mainly to the expression of two small oncoproteins, E6 and E7. In mammalian PVs, E6 contains two 70-residue zinc-binding repeats, whereas E7 consists of a natively unfolded N-terminal region followed by a zinc-binding domain which folds as an obligate homodimer. Here, we show that both the novel francolin bird PV Francolinus leucoscepus PV type 1 (FlPV-1) and the chaffinch bird PV Fringilla coelebs PV contain unusual E6 and E7 proteins. The avian E7 proteins contain an extended unfolded N terminus and a zinc-binding domain of reduced size, whereas the avian E6 proteins consist of a single zinc-binding domain. A comparable single-domain E6 protein may have existed in a common ancestor of mammalian and avian PVs. Mammalian E6 C-terminal domains are phylogenetically related to those of single-domain avian E6, whereas mammalian E6 N-terminal domains seem to have emerged by duplication and subsequently diverged from the original ancestral domain. In avian and mammalian cells, both FlPV-1 E6 and FlPV-1 E7 were evenly expressed in the cytoplasm and the nucleus. Finally, samples of full-length FlPV-1 E6 and the FlPV-1 E7 C-terminal zinc-binding domain were prepared for biophysical analysis. Both constructs were highly soluble and well folded, according to nuclear magnetic resonance spectroscopy measurements. PMID:19553340

Van Doorslaer, Koenraad; Ould M'hamed Ould Sidi, Abdellahi; Zanier, Katia; Rybin, Vladimir; Deryckère, François; Rector, Annabel; Burk, Robert D.; Lienau, E. Kurt; van Ranst, Marc; Travé, Gilles

2009-01-01

37

ADXS-HPV: A therapeutic Listeria vaccination targeting cervical cancers expressing the HPV E7 antigen.  

PubMed

Listeria monocytogenes is a bacterium that can be genetically modified to express fusion proteins with antigens specific to certain cancer models. This technology has been harnessed to develop ADXS11-001, a vaccine that aims to elicit an immune response against human papillomavirus (HPV) oncoprotein E7.??Pre-clinical studies assessing the efficacy of recombinant Listeria vaccination targeting this same oncoprotein have consistently demonstrated successful reduction of in vivo tumor burden among animal cancer models. Several clinical trials are underway to assess the efficacy of ADXS11-001 in eliciting both immune and clinical responses against HPV-related human cervical, oropharyngeal and anal cancers. PMID:25483687

Cory, Lori; Chu, Christina

2014-11-01

38

Overexpression of human papillomavirus (HPV) type 16 oncoproteins promotes angiogenesis via enhancing HIF-1? and VEGF expression in non-small cell lung cancer cells.  

PubMed

HPV-16 infection may play an important role in the development of non-small cell lung cancer (NSCLC) among never-smokers. Due to the critical role of angiogenesis in NSCLC development, we describe here the effect of HPV-16 oncoproteins on angiogenesis in NSCLC and the underlying mechanisms. We found that overexpression of HPV-16 E6 and E7 oncoproteins in NSCLC cells significantly promoted angiogenesis both in vitro and in vivo, and correspondingly, an enhanced expression of HIF-1? and VEGF, important pro-angiogenic factors in tumor angiogenesis. Meanwhile, overexpression of HPV-16 oncoproteins also led to HIF-1?-dependent increases in the secretion of several other pro-angiogenic factors, including IL-8. Our findings suggest that HPV-16 oncoproteins contribute to the development of NSCLC possibly by promoting HIF-1?/VEGF-mediated tumor angiogenesis. PMID:21868151

Li, Gang; He, Li; Zhang, Erying; Shi, Jingli; Zhang, Qunzhou; Le, Anh D; Zhou, Keyuan; Tang, Xudong

2011-12-01

39

Luteolin induces intrinsic apoptosis via inhibition of E6/E7 oncogenes and activation of extrinsic and intrinsic signaling pathways in HPV-18-associated cells.  

PubMed

Luteolin, a flavonoid extracted from a number of plants with recognized anticancer, anti-inflammatory and anti-oxidative activities, inhibits angiogenic processes and modulates multidrug resistance. However, the efficacy and mechanisms of action of this flavonoid agent are still undergoing study. In order to elucidate whether luteolin exhibits an anticancer effect in cervical cancer cells, HeLa cells were incubated with luteolin and apoptosis was assessed by observing nuclear morphological changes, and performing Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) staining. Cell cycle analysis, western blotting, RT-PCR and mitochondrial membrane potential measurements were also carried out. Luteolin showed a significant dose-dependent cytotoxic effect only in human papillomavirus (HPV)-positive cervical cancer cells, when compared to its effect on HPV-negative cervical cancer C33A cells. Expression levels of human papilloma virus E6 and E7 oncogenes were suppressed, those of related factors pRb and p53 were recovered and E2F5 was increased by luteolin treatment. Furthermore, luteolin enhanced the expression of death receptors and death receptor downstream factors such as Fas/FasL, DR5/TRAIL and FADD in HeLa cells, and activated caspase cascades. In particular, luteolin enhanced the activity of caspase-3 and -8 in a dose-dependent manner. Activation of caspase-3 induced caspase-8 activity and vice versa. Luteolin also induced mitochondrial membrane potential collapse and cytochrome c release, and inhibited Bcl-2 and Bcl-xL expression. In conclusion, luteolin exerts anticarcinogenic activity through inhibition of E6 and E7 expression and cross-activation of caspase-3 and -8. Taken together, these results suggest that luteolin induces inactivation of HPV-18 oncogene expression and apoptosis by activating the intrinsic and extrinsic pathways. PMID:24789165

Ham, Sunyoung; Kim, Ki Hong; Kwon, Tae Ho; Bak, Yesol; Lee, Dong Hun; Song, Yong Seok; Park, Su-Ho; Park, Yun Sun; Kim, Man Sub; Kang, Jeong Woo; Hong, Jin Tae; Yoon, Do-Young

2014-06-01

40

A Novel Mucosal Vaccine Based on Live Lactococci Expressing E7 Antigen and IL12 Induces Systemic and Mucosal Immune Responses and Protects Mice against Human Papillomavirus Type 16Induced Tumors  

Microsoft Academic Search

Current strategies to prevent or treat human papillomavirus type 16 (HPV-16) infection are promising, but remain costly. More economical but efficient vaccines are thus needed. In this study, we evaluated the protective effects of mucosally coadministered live Lactococcus lactis strains expressing cell wall-anchored E7 Ag and a secreted form of IL-12 to treat HPV-16-induced tumors in a murine model. When

Luis G. Bermudez-Humaran; Naima G. Cortes-Perez; Francois Lefevre; Sylvie Rabot; Juan M. Alcocer-Gonzalez; Jean-Jacques Gratadoux; Cristina Rodriguez-Padilla; Reyes S. Tamez-Guerra; Gerard Corthier; Alexandra Gruss; Philippe Langella

2005-01-01

41

A20/TNFAIP3 inhibits NF-?B activation induced by the Kaposi's sarcoma-associated herpesvirus vFLIP oncoprotein.  

PubMed

Kaposi's sarcoma-associated herpesvirus (KSHV) K13/vFLIP (viral Flice-inhibitory protein) induces transcription of numerous genes through NF-?B activation, including pro-inflammatory cytokines, which contribute to the pathogenesis of Kaposi's sarcoma (KS). In this study, we report that KSHV vFLIP induces the expression of the NF-?B regulatory proteins A20, ABIN-1 and ABIN-3 (A20-binding NF-?B inhibitors) in primary human endothelial cells, and that KS spindle cells express A20 in KS tissue. In reporter assays, A20 strongly impaired vFLIP-induced NF-?B activation in 293T cells, but ABIN-1 and ABIN-3 did not. Mutational analysis established that the C-terminal domain (residues 427-790) is critical for A20 modulation of NF-?B, but the ubiquitin-editing OTU (ovarian tumor) domain is not. In functional assays, A20 inhibited vFLIP-induced expression of the chemokine IP-10, reduced vFLIP-induced cell proliferation and increased IKK1 protein levels. Thus, we demonstrate that A20 negatively regulates NF-?B activation directly induced by KSHV vFLIP. By attenuating excessive and prolonged vFLIP-induced NF-?B activation that could be harmful to KSHV-infected cells, A20 likely has an important role in the pathogenesis of KSHV-associated diseases, in which vFLIP is expressed. PMID:22525270

Sakakibara, S; Espigol-Frigole, G; Gasperini, P; Uldrick, T S; Yarchoan, R; Tosato, G

2013-03-01

42

Kaposi's sarcoma-associated herpesvirus oncoprotein K13 protects against B cell receptor-induced growth arrest and apoptosis through NF-?B activation.  

PubMed

Kaposi's sarcoma-associated herpesvirus (KSHV) has been linked to the development of Kaposi's sarcoma, primary effusion lymphoma, and multicentric Castleman's disease (MCD). We have characterized the role of KSHV-encoded viral FLICE inhibitory protein (vFLIP) K13 in the modulation of anti-IgM-induced growth arrest and apoptosis in B cells. We demonstrate that K13 protects WEHI 231, an immature B-cell line, against anti-IgM-induced growth arrest and apoptosis. The protective effect of K13 was associated with the activation of the NF-?B pathway and was deficient in a mutant K13 with three alanine substitutions at positions 58 to 60 (K13-58AAA) and a structural homolog, vFLIP E8, both of which lack NF-?B activity. K13 upregulated the expression of NF-?B subunit RelB and blocked the anti-IgM-induced decline in c-Myc and rise in p27(Kip1) that have been associated with growth arrest and apoptosis. K13 also upregulated the expression of Mcl-1, an antiapoptotic member of the Bcl2 family. Finally, K13 protected the mature B-cell line Ramos against anti-IgM-induced apoptosis through NF-?B activation. Inhibition of anti-IgM-induced apoptosis by K13 may contribute to the development of KSHV-associated lymphoproliferative disorders. PMID:23236068

Graham, Ciaren; Matta, Hittu; Yang, Yanqiang; Yi, Han; Suo, Yulan; Tolani, Bhairavi; Chaudhary, Preet M

2013-02-01

43

An E7 Surprise  

E-print Network

We explore some curious implications of Seiberg duality for an SU(2) four-dimensional gauge theory with eight chiral doublets. We argue that two copies of the theory can be deformed by an exactly marginal quartic superpotential so that they acquire an enhanced E7 flavor symmetry. We argue that a single copy of the theory can be used to define an E7-invariant superconformal boundary condition for a theory of 28 five-dimensional free hypermultiplets. Finally, we derive similar statements for three-dimensional gauge theories such as an SU(2) gauge theory with six chiral doublets or Nf=4 SQED.

Tudor Dimofte; Davide Gaiotto

2012-09-06

44

The Leukemia-associated Mll-Ell Oncoprotein Induces Fibroblast Growth Factor 2 (Fgf2)-dependent Cytokine Hypersensitivity in Myeloid Progenitor Cells*  

PubMed Central

The subset of acute myeloid leukemias (AML) with chromosomal translocations involving the MLL gene have a poor prognosis (referred to as 11q23-AML). The MLL fusion proteins that are expressed in 11q23-AML facilitate transcription of a set of HOX genes, including HOXA9 and HOXA10. Because Hox proteins are transcription factors, this suggests the possibility that Hox target genes mediate the adverse effects of MLL fusion proteins in leukemia. Identifying such Hox target genes might provide insights to the pathogenesis and treatment of 11q23-AML. In the current study we found that Mll-Ell (an MLL fusion protein) induced transcriptional activation of the FGF2 gene in a HoxA9- and HoxA10-dependent manner. FGF2 encodes fibroblast growth factor 2 (also referred to as basic fibroblast growth factor). Fgf2 influences proliferation and survival of hematopoietic stem cells and myeloid progenitor cells, and increased Fgf2-expression has been described in AMLs. We determined that expression of Mll-Ell in myeloid progenitor cells resulted in autocrine production of Fgf2 and Fgf2-dependent cytokine hypersensitivity. Therefore, our results implicated increased Fgf2 expression in progenitor proliferation and expansion in 11q23-AML. Because small molecule inhibitors of Fgf-receptors are in human clinical trials, this suggested a potential therapeutic approach to this treatment refractory leukemia. PMID:24089521

Shah, Chirag A.; Bei, Ling; Wang, Hao; Platanias, Leonidas C.; Eklund, Elizabeth A.

2013-01-01

45

Andrographolide downregulates the v-Src and Bcr-Abl oncoproteins and induces Hsp90 cleavage in the ROS-dependent suppression of cancer malignancy.  

PubMed

Andrographolide is a diterpenoid compound isolated from Andrographis paniculata that exhibits anticancer activity. We previously reported that andrographolide suppressed v-Src-mediated cellular transformation by promoting the degradation of Src. In the present study, we demonstrated the involvement of Hsp90 in the andrographolide-mediated inhibition of Src oncogenic activity. Using a proteomics approach, a cleavage fragment of Hsp90? was identified in andrographolide-treated cells. The concentration- and time-dependent induction of Hsp90 cleavage that accompanied the reduction in Src was validated in RK3E cells transformed with either v-Src or a human truncated c-Src variant and treated with andrographolide. In cancer cells, the induction of Hsp90 cleavage by andrographolide and its structural derivatives correlated well with decreased Src levels, the suppression of transformation, and the induction of apoptosis. Moreover, the andrographolide-induced Hsp90 cleavage, Src degradation, inhibition of transformation, and induction of apoptosis were abolished by a ROS inhibitor, N-acetyl-cysteine. Notably, Hsp90 cleavage, decreased levels of Bcr-Abl (another known Hsp90 client protein), and the induction of apoptosis were also observed in human K562 leukemia cells treated with andrographolide or its active derivatives. Together, we demonstrated a novel mechanism by which andrographolide suppressed cancer malignancy that involved inhibiting Hsp90 function and reducing the levels of Hsp90 client proteins. Our results broaden the molecular basis of andrographolide-mediated anticancer activity. PMID:24161787

Liu, Sheng-Hung; Lin, Chao-Hsiung; Liang, Fong-Ping; Chen, Pei-Fen; Kuo, Cheng-Deng; Alam, Mohd Mujahid; Maiti, Barnali; Hung, Shih-Kai; Chi, Chin-Wen; Sun, Chung-Ming; Fu, Shu-Ling

2014-01-15

46

Human papillomavirus type 45 E7 is a transforming protein inducing retinoblastoma protein degradation and anchorage-independent cell cycle progression  

Microsoft Academic Search

High-risk human papillomaviruses (HPV) cause cervical cancer. The biological properties of HPV-45, the third most prevalent high-risk HPV-genotype, are unknown. We demonstrate here that the HPV-45 E7 protein transforms immortalized NIH3T3 fibroblasts, while mutations in either the conserved LXCXE sequence (C28G) or the carboxyl-terminus (?87LQQLF91) significantly abolish this activity. To address the mechanisms underlying cell transformation by HPV-45 E7, we

Dieter Morandell; Ursula Rostek; Veronique Bouvard; Beatriz Campo-Fernández; Marc Fiedler; Pidder Jansen-Dürr; Werner Zwerschke

2008-01-01

47

Molecular Targeting of the Oncoprotein PLK1 in Pediatric Acute Myeloid Leukemia: RO3280, a Novel PLK1 Inhibitor, Induces Apoptosis in Leukemia Cells  

PubMed Central

Polo-like kinase 1 (PLK1) is highly expressed in many cancers and therefore a biomarker of transformation and potential target for the development of cancer-specific small molecule drugs. RO3280 was recently identified as a novel PLK1 inhibitor; however its therapeutic effects in leukemia treatment are still unknown. We found that the PLK1 protein was highly expressed in leukemia cell lines as well as 73.3% (11/15) of pediatric acute myeloid leukemia (AML) samples. PLK1 mRNA expression was significantly higher in AML samples compared with control samples (82.95 ± 110.28 vs. 6.36 ± 6.35; p < 0.001). Kaplan-Meier survival analysis revealed that shorter survival time correlated with high tumor PLK1 expression (p = 0.002). The 50% inhibitory concentration (IC50) of RO3280 for acute leukemia cells was between 74 and 797 nM. The IC50 of RO3280 in primary acute lymphocytic leukemia (ALL) and AML cells was between 35.49 and 110.76 nM and 52.80 and 147.50 nM, respectively. RO3280 induced apoptosis and cell cycle disorder in leukemia cells. RO3280 treatment regulated several apoptosis-associated genes. The regulation of DCC, CDKN1A, BTK, and SOCS2 was verified by western blot. These results provide insights into the potential use of RO3280 for AML therapy; however, the underlying mechanisms remain to be determined. PMID:25574601

Wang, Na-Na; Li, Zhi-Heng; Zhao, He; Tao, Yan-Fang; Xu, Li-Xiao; Lu, Jun; Cao, Lan; Du, Xiao-Juan; Sun, Li-Chao; Zhao, Wen-Li; Xiao, Pei-Fang; Fang, Fang; Su, Guang-Hao; Li, Yan-Hong; Li, Gang; Li, Yi-Ping; Xu, Yun-Yun; Zhou, Hui-Ting; Wu, Yi; Jin, Mei-Fang; Liu, Lin; Ni, Jian; Wang, Jian; Hu, Shao-Yan; Zhu, Xue-Ming; Feng, Xing; Pan, Jian

2015-01-01

48

Molecular targets of HPV oncoproteins: potential biomarkers for cervical carcinogenesis.  

PubMed

Cervical cancer is the second most common cancer among women worldwide and is responsible for 275,000 deaths each year. Persistent infection with high-risk human papillomavirus (HR-HPV) is an essential factor for the development of cervical cancer. Although the process is not fully understood, molecular mechanisms caused by HPV infection are necessary for its development and reveal a large number of potential biomarkers for diagnosis and prognosis. These molecules are host genes and/or proteins, and cellular microRNAs involved in cell cycle regulation that result from disturbed expression of HR-HPV E5, E6 and E7 oncoproteins. One of the current challenges in medicine is to discover potent biomarkers that can correctly diagnose cervical premalignant lesions and standardize clinical management. Currently, studies are showing that some of these molecules are potential biomarkers of cervical carcinogenesis, and it is possible to carry out a more accurate diagnosis and provide more appropriate follow-up treatment for women with cervical dysplasia. In this paper, we review recent research studies on cell cycle molecules deregulated by HPV infections, as well as their potential use for cervical cancer screening. PMID:24388872

de Freitas, Antonio Carlos; Coimbra, Eliane Campos; Leitão, Maria da Conceição Gomes

2014-04-01

49

Species restriction of Herpesvirus saimiri and Herpesvirus ateles: human lymphocyte transformation correlates with distinct signaling properties of viral oncoproteins.  

PubMed

The potential of Herpesvirus saimiri (HVS) subgroups A, B and C and Herpesvirus ateles (HVA) to transform primary T cells to permanent growth in vitro is restricted by the primate host species and by viral variability represented by distinct viral oncoproteins. We now addressed the relation between the transforming potential of the different viruses and the signaling pathways activated by transiently expressed oncoproteins. Marmoset lymphocytes were transformed by all HVS subgroups as well as HVA, while transformation of human cells was restricted to HVS-C and, unexpectedly, HVA. NF-?B and Src-family kinase (SFK) activity was required for survival of all transformed lymphocytes. Accordingly, NF-?B was induced by oncoproteins of all viruses. In contrast, SFK-related signaling was detectable only for oncoproteins of HVS-C and HVA. Thus, the restricted transformation of human lymphocytes likely correlates with the specific SFK targeting by these oncoproteins. These results will enable further studies into novel SFK effector mechanisms relevant for T-cell proliferation. PMID:22374337

Katsch, Kristin; de Jong, Sarah Jill; Schmidt, Monika; Müller-Fleckenstein, Ingrid; Fleckenstein, Bernhard; Albrecht, Jens-Christian; Biesinger, Brigitte

2012-05-01

50

A p300\\/CBP-associated factor that competes with the adenoviral oncoprotein E1A  

Microsoft Academic Search

The adenoviral oncoprotein E1A induces progression through the cell cycle by binding to the products of the p300\\/CBP and retinoblastoma gene families. A new cellular p300\\/CBP-associated factor (P\\/CAF) having intrinsic histone acetylase activity has been identified that competes with E1A. Exogenous expression of P\\/CAF in HeLa cells inhibits cell-cycle progression and counteracts the mitogenic activity of E1A. E1A disturbs the

Xiang-Jiao Yang; Vasily V. Ogryzko; Jun-Ichi Nishikawa; Bruce H. Howard; Yoshihiro Nakatani

1996-01-01

51

Clinical potential of the ERG oncoprotein in prostate cancer  

Microsoft Academic Search

Oncogenic activation of ERG resulting from gene fusion is present in over half of all patients with prostate cancer in Western countries. Although the underlying genetic mechanisms have been extensively studied, evaluation of the ERG oncoprotein—the translational product of ERG gene fusions—has just begun. The robust correlation between ERG oncoprotein detection and gene fusion status enables rapid characterization of this

Philip Rosen; Isabell A. Sesterhenn; Stephen A. Brassell; David G. McLeod; Shiv Srivastava; Albert Dobi

2012-01-01

52

Enhancement of Ad-CRT/E7-mediated antitumor effect by preimmunization with L. lactis expressing HPV-16 E7.  

PubMed

Although current polyvalent vaccines can prevent development of cervical cancer, they cannot be used to treat patients who already have the disease. Adenovirus expressing calreticulin-E7 (Ad-CRT-E7) has shown promising results in the cervical cancer murine model. We also demonstrated that immunization with Lactococcus lactis encoding HPV-16 E7 (Ll-E7) anchored to its surface induces significant HPV-16 E7-specific immune response. Here, we assessed the combination of both approaches in the treatment of a cervical cancer animal model. Intranasal preimmunization of Ll-E7, followed by a single Ad-CRT/E7 application, induced ?80% of tumor suppression in comparison with controls. Mice treated with a combination of Ll-E7 and Ad-CRT/E7 resulted in a 70% survival rate 300 days post-treatment, whereas 100% of the mice in the control groups died by 50 days. Significant CD8+ cytotoxic T-lymphocytes infiltration was detected in the tumors of mice treated with Ll-E7+Ad-CRT/E7. Tumors with regression showed a greater number of positive cells for in situ TUNEL staining than controls. Our results suggest that preimmunization with Ll-E7 enhances the Ad-CRT/E7-mediated antitumor effect. This treatment provides an enormous advantage over repeated applications of Ad-CRT/E7 by maintaining the effectiveness of the three-dose application of Ad-CRT/E7, but avoiding the high systemic toxicities associated with such repeat treatments. PMID:25216057

Rangel-Colmenero, Blanca R; Gomez-Gutierrez, Jorge G; Villatoro-Hernández, Julio; Zavala-Flores, Laura M; Quistián-Martínez, Deyanira; Rojas-Martínez, Augusto; Arce-Mendoza, Alma Y; Guzmán-López, Santos; Montes-de-Oca-Luna, Roberto; Saucedo-Cárdenas, Odila

2014-11-01

53

The papillomavirus E7 proteins.  

PubMed

E7 is an accessory protein that is not encoded by all papillomaviruses. The E7 amino terminus contains two regions of similarity to conserved regions 1 and 2 of the adenovirus E1A protein, which are also conserved in the simian vacuolating virus 40 large tumor antigen. The E7 carboxyl terminus consists of a zinc-binding motif, which is related to similar motifs in E6 proteins. E7 proteins play a central role in the human papillomavirus life cycle, reprogramming the cellular environment to be conducive to viral replication. E7 proteins encoded by the cancer-associated alpha human papillomaviruses have potent transforming activities, which together with E6, are necessary but not sufficient to render their host squamous epithelial cell tumorigenic. This article strives to provide a comprehensive summary of the published research studies on human papillomavirus E7 proteins. PMID:23731972

Roman, Ann; Munger, Karl

2013-10-01

54

Epigenetic roles of MLL oncoproteins are dependent on NF-?B  

PubMed Central

Summary MLL fusion proteins in leukemia induce aberrant transcriptional elongation and associated chromatin perturbations, however the upstream signaling pathways and activators that recruit or retain MLL oncoproteins at initiated promoters are unknown. Through functional and comparative genomic studies, we identified an essential role for NF-?B signaling in MLL leukemia. Suppression of NF-?B led to robust anti-leukemia effects that phenocopied loss of functional MLL oncoprotein or associated epigenetic cofactors. The NF-?B subunit RELA occupies promoter regions of crucial MLL target genes and sustains the MLL-dependent leukemia stem cell program. IKK/NF-?B signaling is required for wild-type and fusion MLL protein retention and maintenance of associated histone modifications providing a molecular rationale for enhanced efficacy in therapeutic targeting of this pathway in MLL leukemias. PMID:24054986

Kuo, Hsu-Ping; Wang, Zhong; Lee, Dung-Fang; Iwasaki, Masayuki; Duque-Afonso, Jesus; Wong, Stephen H.K.; Lin, Chiou-Hong; Figueroa, Maria E.; Su, Jie; Lemischka, Ihor R.; Cleary, Michael L.

2013-01-01

55

The E6 Oncoproteins of High-Risk Papillomaviruses Bind to a Novel Putative GAP Protein, E6TP1, and Target It for Degradation  

Microsoft Academic Search

The high-risk human papillomaviruses (HPVs) are associated with carcinomas of the cervix and other genital tumors. Previous studies have identified two viral oncoproteins, E6 and E7, which are expressed in the majority of HPV-associated carcinomas. The ability of high-risk HPV E6 protein to immortalize human mam- mary epithelial cells (MECs) has provided a single-gene model to study the mechanisms of

QINGSHEN GAO; SEETHA SRINIVASAN; SARAH N. BOYER; DAVID E. WAZER; VIMLA BAND

1999-01-01

56

Post-Translational Control of IL-1? via the Human Papillomavirus Type 16 E6 Oncoprotein: A Novel Mechanism of Innate Immune Escape Mediated by the E3-Ubiquitin Ligase E6-AP and p53  

PubMed Central

Infections with high-risk human papillomaviruses (HPVs) are causally involved in the development of anogenital cancer. HPVs apparently evade the innate immune response of their host cells by dysregulating immunomodulatory factors such as cytokines and chemokines, thereby creating a microenvironment that favors malignancy. One central key player in the immune surveillance interactome is interleukin-1 beta (IL-1?) which not only mediates inflammation, but also links innate and adaptive immunity. Because of its pleiotropic physiological effects, IL-1? production is tightly controlled on transcriptional, post-translational and secretory levels. Here, we describe a novel mechanism how the high-risk HPV16 E6 oncoprotein abrogates IL-1? processing and secretion in a NALP3 inflammasome-independent manner. We analyzed IL-1? regulation in immortalized keratinocytes that harbor the HPV16 E6 and/or E7 oncogenes as well as HPV-positive cervical tumor cells. While in primary and in E7-immortalized human keratinocytes the secretion of IL-1? was highly inducible upon inflammasome activation, E6-positive cells did not respond. Western blot analyses revealed a strong reduction of basal intracellular levels of pro-IL-1? that was independent of dysregulation of the NALP3 inflammasome, autophagy or lysosomal activity. Instead, we demonstrate that pro-IL-1? is degraded in a proteasome-dependent manner in E6-positive cells which is mediated via the ubiquitin ligase E6-AP and p53. Conversely, in E6- and E6/E7-immortalized cells pro-IL-1? levels were restored by siRNA knock-down of E6-AP and simultaneous recovery of functional p53. In the context of HPV-induced carcinogenesis, these data suggest a novel post-translational mechanism of pro-IL-1? regulation which ultimately inhibits the secretion of IL-1? in virus-infected keratinocytes. The clinical relevance of our results was further confirmed in HPV-positive tissue samples, where a gradual decrease of IL-1? towards cervical cancer could be discerned. Hence, attenuation of IL-1? by the HPV16 E6 oncoprotein in immortalized cells is apparently a crucial step in viral immune evasion and initiation of malignancy. PMID:23935506

Niebler, Martina; Qian, Xu; Höfler, Daniela; Kogosov, Vlada; Kaewprag, Jittranan; Kaufmann, Andreas M.; Ly, Regina; Böhmer, Gerd; Zawatzky, Rainer; Rösl, Frank; Rincon-Orozco, Bladimiro

2013-01-01

57

The Bmi1 oncoprotein interacts with dinG and MPh2: the role of RING finger domains  

Microsoft Academic Search

Experimentally-induced mutations in the C3HC4 RING finger domain of the Bmi-1 oncoprotein block its ability to induce lymphomas in mice. In this report, the role of the Bmi-1 RING finger in mediating protein-protein interactions is examined using the yeast two-hybrid system. Bmi-1 interacts directly with the RING finger protein dinG\\/RING1B. Heterodimerization of the two proteins requires the intact RING finger

Charles S Hemenway; Benjamin W Halligan; Laura S Levy

1998-01-01

58

Karyopherin {beta}3: A new cellular target for the HPV-16 E5 oncoprotein  

SciTech Connect

Epidemiological and experimental studies have shown that high-risk human papillomaviruses (HPVs) are the causative agents of cervical cancer worldwide, and that HPV-16 is associated with more than half of these cases. In addition to the well-characterized E6 and E7 oncoproteins of HPV-16, recent evidence increasingly has implicated the HPV-16 E5 protein (16E5) as an important mediator of oncogenic transformation. Since 16E5 has no known intrinsic enzymatic activity, its effects on infected cells are most likely mediated by interactions with various cellular proteins and/or its documented association with lipid rafts. In the present study, we describe a new cellular target that binds to 16E5 in COS cells and in stable human ectocervical cell lines. This target is karyopherin {beta}3, a member of the nuclear import receptor family with critical roles in the nuclear import of ribosomal proteins and in the secretory pathway.

Krawczyk, Ewa [Department of Pathology, Georgetown University Medical School, 3900 Reservoir Road NW, Washington, DC 20057 (United States); Hanover, John A. [Laboratory of Cell Biochemistry and Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892 (United States); Schlegel, Richard [Department of Pathology, Georgetown University Medical School, 3900 Reservoir Road NW, Washington, DC 20057 (United States); Suprynowicz, Frank A. [Department of Pathology, Georgetown University Medical School, 3900 Reservoir Road NW, Washington, DC 20057 (United States)], E-mail: suprynfa@georgetown.edu

2008-07-11

59

Analysis of human papillomavirus E7 protein status in C-33A cervical cancer cells.  

PubMed

High-risk human papillomaviruses (HPV) are the main etiologic factor for the development of cervical cancer. Infections by these viruses have been detected in virtually all cervical cancers. C-33A is one of the rare cervical cancer derived cell lines considered as HPV-negative. Employing monoclonal antibodies raised against a conformational epitope of the HPV-16 E7 oncoprotein, we present evidence suggesting that E7-positive cells can be sporadically and transiently detected in C-33A cell cultures. Immunoblotting with affinity-purified rabbit polyclonal anti-HPV 16 E7 antisera and q-RT-PCR analysis suggest that these cells do probably not express HPV-16 E7. Moreover, we show that the HPV E7 protein level differs considerably between individual cells in cultures of several established cervical cancer cell lines. Our data suggest that expression of the E7 protein is variable in established cervical cancer cell lines including C-33A cells. PMID:25326774

Kaiser, Andreas; Jenewein, Brigitte; Pircher, Haymo; Rostek, Ursula; Jansen-Dürr, Pidder; Zwerschke, Werner

2014-10-19

60

Herpesvirus saimiri Oncoproteins Tip and StpC Synergistically Stimulate NF-?B Activity and Interleukin2 Gene Expression  

Microsoft Academic Search

Saimiriine herpesvirus 2 (Herpesvirus saimiri) is capable of inducing lethal T-cell lymphoproliferative diseases in primates and of immortalizing human T lymphocytes in vitro. Two viral oncoproteins, Tip and StpC, are essential for T-cell transformation by Herpesvirus saimiri strains of the subgroup C, which exhibits a higher transformation potential than other subgroups of this virus. Despite the importance of these proteins,

Joseph J. Merlo; Alexander Y. Tsygankov

2001-01-01

61

Ras oncoproteins transfer from melanoma cells to T cells and modulate their effector functions.  

PubMed

Lymphocytes establish dynamic cell-cell interactions with the cells they scan. Previous studies show that upon cell contact, various membrane-associated proteins, such as Ras-family proteins, transfer from B to T and NK lymphocytes. Mutations in RAS genes that encode constitutively active, GTP-bound, oncoproteins are rather common in human cancers; for instance, melanoma. Cancer immunoediting has been postulated to contribute to the elimination of malignant melanoma. Thus, we asked whether Ras oncoproteins can transfer from melanoma to T cells, including tumor-infiltrating lymphocytes (TILs), and subsequently induce functional effects in the adopting T cells. To explore this issue, we genetically engineered an HLA-A2(+) melanoma cell line, MEL526, to express GFP or GFP-tagged H-Ras mutants stably. In this study, we show by an in vitro coculture system that GFP-tagged H-Ras, but not GFP, transfers from MEL526 to T cells and localizes to the inner aspect of their plasma membrane. This cell-contact-dependent process was increased by TCR stimulation and did not require strict Ag specificity. Importantly, we found a positive correlation between the levels of the acquired constitutively active H-RasG12V and ERK1/2 phosphorylation within the adopting TILs. We also show a significant increase in IFN-? production and cytotoxic activity in TILs that acquired H-RasG12V compared to TILs that acquired a different H-Ras mutant. In conclusion, our findings demonstrate a hitherto unknown phenomenon of intercellular transfer of Ras oncoproteins from melanoma to TILs that consequently augments their effector functions. PMID:23028055

Vernitsky, Helly; Rechavi, Oded; Rainy, Nir; Besser, Michal J; Nagar, Meital; Schachter, Jacob; Lerenthal, Yaniv; Ehrlich, Marcelo; Kloog, Yoel; Goldstein, Itamar

2012-11-01

62

Epstein-Barr Virus Oncoprotein Super-enhancers Control B Cell Growth.  

PubMed

Super-enhancers are clusters of gene-regulatory sites bound by multiple transcription factors that govern cell transcription, development, phenotype, and oncogenesis. By examining Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines (LCLs), we identified four EBV oncoproteins and five EBV-activated NF-?B subunits co-occupying ?1,800 enhancer sites. Of these, 187 had markedly higher and broader histone H3K27ac signals, characteristic of super-enhancers, and were designated "EBV super-enhancers." EBV super-enhancer-associated genes included the MYC and BCL2 oncogenes, which enable LCL proliferation and survival. EBV super-enhancers were enriched for B cell transcription factor motifs and had high co-occupancy of STAT5 and NFAT transcription factors (TFs). EBV super-enhancer-associated genes were more highly expressed than other LCL genes. Disrupting EBV super-enhancers by the bromodomain inhibitor JQ1 or conditionally inactivating an EBV oncoprotein or NF-?B decreased MYC or BCL2 expression and arrested LCL growth. These findings provide insight into mechanisms of EBV-induced lymphoproliferation and identify potential therapeutic interventions. PMID:25639793

Zhou, Hufeng; Schmidt, Stefanie C S; Jiang, Sizun; Willox, Bradford; Bernhardt, Katharina; Liang, Jun; Johannsen, Eric C; Kharchenko, Peter; Gewurz, Benjamin E; Kieff, Elliott; Zhao, Bo

2015-02-11

63

NSD3-NUT Fusion Oncoprotein in NUT Midline Carcinoma: Implications for a Novel Oncogenic Mechanism  

PubMed Central

NUT midline carcinoma (NMC) is an aggressive subtype of squamous cell carcinoma that typically harbors BRD4/3-NUT fusion oncoproteins that block differentiation and maintain tumor growth. In 20% of cases NUT is fused to uncharacterized non-BRD gene(s). We established a new patient-derived NMC cell line (1221) and demonstrated that it harbors a novel NSD3-NUT fusion oncogene. We find that NSD3-NUT is both necessary and sufficient for the blockade of differentiation and maintenance of proliferation in NMC cells. NSD3-NUT binds to BRD4, and BRD bromodomain inhibitors induce differentiation and arrest proliferation of 1221 cells. We find further that NSD3 is required for the blockade of differentiation in BRD4-NUT-expressing NMCs. These findings identify NSD3 as a novel critical oncogenic component and potential therapeutic target in NMC. PMID:24875858

French, Christopher A.; Rahman, Shaila; Walsh, Erica M.; Kühnle, Simone; Grayson, Adlai R.; Lemieux, Madeleine E.; Grunfeld, Noam; Rubin, Brian P.; Antonescu, Cristina R.; Zhang, Songlin; Venkatramani, Rajkumar; Cin, Paola Dal; Howley, Peter M.

2014-01-01

64

Adenoviral E1B55K oncoprotein sequesters candidate leukemia suppressor sequence-specific single-stranded DNA-binding protein 2 into aggresomes  

Microsoft Academic Search

Sequence-specific single-stranded DNA-binding protein 2 (SSBP2) is a candidate tumor suppressor for human acute myelogenous leukemia (AML). Inducible expression of SSBP2 causes growth arrest and partial differentiation in AML cells. Here, we report that the adenoviral oncoprotein E1B55K directly binds to endogenous SSBP2 protein and sequesters it into juxtanuclear bodies in adenovirally transformed human embryonic kidney (HEK) 293 cells. Similarly,

H B Fleisig; N I Orazio; H Liang; A F Tyler; H P Adams; M D Weitzman; L Nagarajan

2007-01-01

65

Modulation of oxidative stress by twist oncoproteins.  

PubMed

Expression of developmental genes Twist1 and Twist2 is reactivated in many human tumors. Among their oncogenic activities, induction of epithelial to mesenchymal transition is believed to increase cell motility and invasiveness and may be related to acquisition of cancer stem cell phenotype. In addition, Twist proteins promote malignant conversion by overriding two oncogene-induced failsafe programs: senescence and apoptosis. Reactive oxygen species (ROS) are also important mediators of apoptosis, senescence and motility and are tightly linked to disease, notably to cancer. We report here that Twist factors and ROS are functionally linked. In wild type cells both Twist1 and Twist2 exhibit antioxidant properties. We show that Twist-driven modulation of oncogene-induced apoptosis is linked to its effects on oxidative stress. Finally, we identify several targets that mediate Twist antioxidant activity. These findings unveil a new function of Twist factors that could be important in explaining their pleiotropic role during carcinogenesis. PMID:23967308

Floc'h, Nicolas; Kolodziejski, Jakub; Akkari, Leila; Simonin, Yannick; Ansieau, Stéphane; Puisieux, Alain; Hibner, Urszula; Lassus, Patrice

2013-01-01

66

Modulation of Oxidative Stress by Twist Oncoproteins  

PubMed Central

Expression of developmental genes Twist1 and Twist2 is reactivated in many human tumors. Among their oncogenic activities, induction of epithelial to mesenchymal transition is believed to increase cell motility and invasiveness and may be related to acquisition of cancer stem cell phenotype. In addition, Twist proteins promote malignant conversion by overriding two oncogene-induced failsafe programs: senescence and apoptosis. Reactive oxygen species (ROS) are also important mediators of apoptosis, senescence and motility and are tightly linked to disease, notably to cancer. We report here that Twist factors and ROS are functionally linked. In wild type cells both Twist1 and Twist2 exhibit antioxidant properties. We show that Twist-driven modulation of oncogene-induced apoptosis is linked to its effects on oxidative stress. Finally, we identify several targets that mediate Twist antioxidant activity. These findings unveil a new function of Twist factors that could be important in explaining their pleiotropic role during carcinogenesis. PMID:23967308

Akkari, Leila; Simonin, Yannick; Ansieau, Stéphane; Puisieux, Alain; Hibner, Urszula; Lassus, Patrice

2013-01-01

67

Activation of human papillomavirus type 18 E6-E7 oncogene expression by transcription factor Sp1.  

PubMed Central

The human papillomavirus 18 (HPV18) E6 and E7 proteins are considered to be primarily responsive for the transforming activity of the virus. In order to analyse the molecular mechanisms resulting in viral oncoprotein expression, it is necessary to identify the factors involved in the transcriptional regulation of the E6/E7 genes. Here we define by gel retardation experiments a sequence aberrant Sp1 binding site present in the promoter proximal part of the viral transcriptional control region (Upstream Regulatory Region, URR). Functional analyses employing transient reporter assays reveal that this Sp1 element is required for an efficient stimulation of the HPV18 E6/E7-promoter. Mutation of the Sp1 element in the natural context of the HPV18 URR leads to a strong decrease in the activity of the E6/E7-promoter in several cell lines. The magnitude of reduction varies between different cell types and is higher in cell lines of epithelial origin when compared with nonepithelial cells. Cotransfection assays using Sp1 expression vector systems further define the promoter proximal HPV18 Sp1 binding motif as a functional Sp1 element in vivo and show that its integrity is essential for the stimulation of the E6/E7-promoter by augmented levels of Sp1. These results indicate, that the cellular transcription factor Sp1 plays an important role for the stimulation of the E6/E7-promoter by the viral URR and represents a major determinant for the expression of HPV18 transforming genes E6 and E7. Images PMID:1336181

Hoppe-Seyler, F; Butz, K

1992-01-01

68

STP-A11, an oncoprotein of Herpesvirus saimiri augments both NF-kappaB and AP-1 transcription activity through TRAF6.  

PubMed

Herpesvirus saimiri (HVS), a member of the gamma-herpesvirus family, encodes an oncoprotein called Saimiri Transforming Protein (STP) which is required for lymphoma induction in non-human primates. However, a detailed mechanism of STP-A11-induced oncogenesis has not been revealed yet. We first report that STP-A11 oncoprotein interacts with TNF-alpha receptor-associated factor (TRAF) 6 in vivo and in vitro. Mutagenesis analysis of the TRAF6-binding motif (10)PQENDE(15) in STP-A11 reveals that Glu (E)(12) residue is critical for binding to TRAF6 and NF-kappaB activation. Interestingly, co-expression of E12A mutant, lack of TRAF6 binding, with cellular Src (Src) results in decreased transcriptional activity of Stat3 and AP-1, a novel target of STP-A11 compared to that of wild type. Furthermore, the presence of STP-A11 enhances the association of TRAF6 with Src and induces the translocation of both TRAF6 and Src to a nonionic detergent-insoluble fraction. Taken together, these studies suggest that STP-A11 oncoprotein up-regulates both NF-kappaB and AP-1 transcription activity through TRAF6, which would ultimately contribute cellular transformation. PMID:17334229

Jeong, Sunam; Cho, Il-Rae; An, Won Gun; Jhun, Byung Hak; Lee, BokSoo; Park, Keerang; Chung, Young-Hwa

2007-02-28

69

USP11 stabilizes HPV-16E7 and further modulates the E7 biological activity.  

PubMed

HPV-16E7 is a major transforming protein, which has been implicated in the development of cervical cancer. The stability of E7 is thus important to ensure its fully functional status. Using the yeast two-hybrid system, we found that USP11 (ubiquitin-specific protease 11), a member of a protein family that cleaves polyubiquitin chains and/or ubiquitin precursors, interacts and forms a specific complex with HPV-16E7. Our results indicate that the USP11 can greatly increase the steady state level of HPV-16E7 by reducing ubiquitination and attenuating E7 degradation. In contrast, a catalytically inactive mutant of USP11 abolished the deubiquitinating ability and returned E7 to a normal rate of degradation. Moreover, USP11 not only protected E7 from ubiquitination but also influenced E7 function as a modulator of cell growth status. These results suggest that USP11 plays an important role in regulating the levels of E7 protein and subsequently affects the biological function of E7 as well as its contribution to cell transformation by HPV-16E7. PMID:18408009

Lin, Ching-Hui; Chang, Hung-Shu; Yu, Winston C Y

2008-06-01

70

Actin-dependent activation of serum response factor in T cells by the viral oncoprotein tip  

PubMed Central

Serum response factor (SRF) acts as a multifunctional transcription factor regulated by mutually exclusive interactions with ternary complex factors (TCFs) or myocardin-related transcription factors (MRTFs). Binding of Rho- and actin-regulated MRTF:SRF complexes to target gene promoters requires an SRF-binding site only, whereas MAPK-regulated TCF:SRF complexes in addition rely on flanking sequences present in the serum response element (SRE). Here, we report on the activation of an SRE luciferase reporter by Tip, the viral oncoprotein essentially contributing to human T-cell transformation by Herpesvirus saimiri. SRE activation in Tip-expressing Jurkat T cells could not be attributed to triggering of the MAPK pathway. Therefore, we further analyzed the contribution of MRTF complexes. Indeed, Tip also activated a reporter construct responsive to MRTF:SRF. Activation of this reporter was abrogated by overexpression of a dominant negative mutant of the MRTF-family member MAL. Moreover, enrichment of monomeric actin suppressed the Tip-induced reporter activity. Further upstream, the Rho-family GTPase Rac, was found to be required for MRTF:SRF reporter activation by Tip. Initiation of this pathway was strictly dependent on Tip's ability to interact with Lck and on the activity of this Src-family kinase. Independent of Tip, T-cell stimulation orchestrates Src-family kinase, MAPK and actin pathways to induce SRF. These findings establish actin-regulated transcription in human T cells and suggest its role in viral oncogenesis. PMID:22385615

2012-01-01

71

Tyrosine Phosphorylation of the Tio Oncoprotein Is Essential for Transformation of Primary Human T Cells  

Microsoft Academic Search

Human T cells are transformed to antigen-independent permanent growth in vitro upon infection with herpesvirus saimiri subgroup C strains. The viral oncoproteins required for this process, StpC and Tip, could be replaced by Tio, the oncoprotein of herpesvirus ateles. Here we demonstrate that proliferation of lympho- cytes transformed with Tio-recombinant herpesvirus saimiri required the activity of Src family kinases. Src

Jens-Christian Albrecht; Ingrid Muller-Fleckenstein; Monika Schmidt; Bernhard Fleckenstein; Brigitte Biesinger

2005-01-01

72

Progeny of Lgr5-expressing hair follicle stem cell contributes to papillomavirus-induced tumor development in epidermis.  

PubMed

Epidermal keratinocytes and hair follicle (HF) stem cells (SCs) expressing oncogenes are competent at developing squamous cell carcinomas (SCCs) in epidermis and HFs, respectively. To determine whether bulge and hair germ (HG) SCs from HF contribute to SCC generation at distant epidermis, the most frequent epidermal region where these lesions arise in human skin, we used a skin cancer mouse model expressing E6 and E7 oncoproteins from Human papillomavirus (HPV) 16 in SCs and basal keratinocytes. This previously described mouse model recapitulates the human skin papillomavirus-induced SCC pathology. We show that E6 and E7 expression promote the expansion of keratin 15 (K15)-expressing cells. These K15(+) aberrant cells exhibit some HGSC markers and diminished expression of Tcf3 and Sox9 hair SC specification genes, which are accumulated in HFs and mislocalized to interfollicular epidermis. Leucine-rich G-protein-coupled receptor 5 (Lgr5)-expressing SCs, localized in the bulge and HG, are the origin of the expanded K15(+) cell population. A large subset of the Lgr5(+) SC progeny, expressing K15 and P-cadherin, is aberrantly mobilized to the upper region of HFs and the epidermis, and accumulates at E6/E7-induced pre-neoplastic lesions and epidermal tumors. These findings indicate that aberrant accumulation of altered SCs in HFs and their subsequent migration to the epidermis contribute to HPV-induced tumor development. PMID:22945646

da Silva-Diz, V; Solé-Sánchez, S; Valdés-Gutiérrez, A; Urpí, M; Riba-Artés, D; Penin, R M; Pascual, G; González-Suárez, E; Casanovas, O; Viñals, F; Paramio, J M; Batlle, E; Muñoz, P

2013-08-01

73

Oncoprotein 18 is a phosphorylation-responsive regulator of microtubule dynamics.  

PubMed Central

Oncoprotein 18 (Op18, also termed p19, p18, prosolin or stathmin) is a cytosolic protein of previously unknown function. Phosphorylation of Op18 is cell cycle regulated by cyclin-dependent kinases (CDKs), and expression of a 'CDK target site-deficient mutant' results in a phenotype indicative of a role for Op18 during mitosis. This phenotype is compatible with the idea that Op18 is a phosphorylation-responsive regulator of microtubule (MT) dynamics. Therefore, in this study, we analyzed MTs in cells induced to express either wild-type or mutated Op18. The results showed that wild-type Op18 and a CDK target site mutant both efficiently elicited rapid depolymerization of MTs. This result contrasts with clear-cut differences in their cell cycle phenotypes. Morphological analysis of MTs explained this apparent discrepancy: while interphase MTs were depolymerized in cells expressing either Op18 derivative, apparently normal mitotic spindles were formed only in cells overexpressing wild-type Op18. This result correlates with our finding that only mutated Op18 causes a block during mitosis. Hence, we conclude that Op18 decreases MT stability and that this activity of Op18 is subject to cell cycle regulation by CDKs. Images PMID:8895574

Marklund, U; Larsson, N; Gradin, H M; Brattsand, G; Gullberg, M

1996-01-01

74

The multifaceted oncoprotein Tax: subcellular localization, posttranslational modifications, and NF-?B activation.  

PubMed

The human T-cell lymphotropic virus type-I (HTLV-I) is the etiologic agent of adult T-cell leukemia/lymphoma (ATL) and of tropical spastic paraparesis/HTLV-I-associated myelopathy. Constitutive NF-?B activation by the viral oncoprotein Tax plays a crucial role in the induction and maintenance of cellular proliferation, transformation, and inhibition of apoptosis. In an attempt to provide a general view of the molecular mechanisms of constitutive Tax-induced NF-?B activation, we summarize in this review the recent body of literature that supports a major role for Tax posttranslational modifications, chiefly ubiquitination, and SUMOylation, in the NF-?B activity of Tax. These modifications indeed participate in the control of Tax subcellular localization and modulate its protein-protein interaction potential. Tax posttranslational modifications, which highlight the ability of HTLV-I to optimize its limited viral genome size, might represent an attractive target for the design of new therapies for ATL. PMID:22429853

Kfoury, Youmna; Nasr, Rihab; Journo, Chloé; Mahieux, Renaud; Pique, Claudine; Bazarbachi, Ali

2012-01-01

75

Gaugings from E7 (7 ) extended geometries  

NASA Astrophysics Data System (ADS)

We discuss the construction of gaugings in recent models of E7 extended geometries, focusing on the two inequivalent S L (8 ) truncations of the theory. In these sectors the conditions for the generation of gaugings in the 36 , 36' , 420 and 420' representations of E7 (7 ) can be compactly expressed in terms of objects which are in the fundamental representation of S L (8 ), making the search of solutions simpler. We present a no-go theorem showing that neither of these truncations lead to the new S O (8 ) dyonic gaugings, at least if the so-called section conditions are implemented. We also show that these truncations can be used to obtain the generalized twist of the seven-sphere, leading to the electric S O (8 ) gaugings.

Baron, Walter H.

2015-01-01

76

Targeting the MUC1-C oncoprotein inhibits self-renewal capacity of breast cancer cells  

PubMed Central

The capacity of breast cancer cells to form mammospheres in non-adherent serum-free culture is used as a functional characteristic of the self-renewing stem-like cell population. The present studies demonstrate that silencing expression of the MUC1-C oncoprotein inhibits growth of luminal MCF-7 and HER2-overexpressing SKBR3 breast cancer cells as mammospheres. We also show that triple-negative MDA-MB-468 breast cancer cells are dependent on MUC1-C for growth as mammospheres and tumor xenografts. Similar results were obtained when MUC1-C function was inhibited by expression of a MUC1-C(CQC?AQA) mutant. Moreover, treatment with the MUC1-C inhibitor GO-203, a cell penetrating peptide that binds to the MUC1-C cytoplasmic domain and blocks MUC1-C function, confirmed the importance of this target for self-renewal. The mechanistic basis for these findings is supported by the demonstration that MUC1-C activates NF-?B, occupies the IL-8 promoter with NF-?B, and induces IL-8 transcription. MUC1-C also induces NF-?B-dependent expression of the IL-8 receptor, CXCR1. In concert with these results, targeting MUC1-C with GO-203 suppresses IL-8/CXCR1 expression and disrupts the formation of established mammospheres. Our findings indicate that MUC1-C contributes to the self-renewal of breast cancer cells by activating the NF-?B?IL-8/CXCR1 pathway and that targeting MUC1-C represents a potential approach for the treatment of this population. PMID:24770886

Jin, Caining; Kufe, Donald

2014-01-01

77

HPV16-E7 Expression in Squamous Epithelium Creates a Local Immune Suppressive Environment via CCL2- and CCL5- Mediated Recruitment of Mast Cells  

PubMed Central

Human Papillomavirus (HPV) 16 E7 protein promotes the transformation of HPV infected epithelium to malignancy. Here, we use a murine model in which the E7 protein of HPV16 is expressed as a transgene in epithelium to show that mast cells are recruited to the basal layer of E7-expressing epithelium, and that this recruitment is dependent on the epithelial hyperproliferation induced by E7 by inactivating Rb dependent cell cycle regulation. E7 induced epithelial hyperplasia is associated with increased epidermal secretion of CCL2 and CCL5 chemokines, which attract mast cells to the skin. Mast cells in E7 transgenic skin, in contrast to those in non-transgenic skin, exhibit degranulation. Notably, we found that resident mast cells in E7 transgenic skin cause local immune suppression as evidenced by tolerance of E7 transgenic skin grafts when mast cells are present compared to the rejection of mast cell-deficient E7 grafts in otherwise competent hosts. Thus, our findings suggest that mast cells, recruited towards CCL2 and CCL5 expressed by epithelium induced to proliferate by E7, may contribute to an immunosuppressive environment that enables the persistence of HPV E7 protein induced pre-cancerous lesions. PMID:25340820

Bergot, Anne-Sophie; Ford, Neill; Leggatt, Graham R.

2014-01-01

78

STP-C, an oncoprotein of herpesvirus saimiri augments the activation of NF-kappaB through ubiquitination of TRAF6.  

PubMed

Herpesvirus saimiri (HVS), a member of the gamma-herpesvirus family, encodes an oncoprotein called Saimiri Transforming Protein (STP) which is required for lymphoma induction in non-human primates. Previous study has shown that STP-C, an oncoprotein of HVS, activates NF-kappaB signaling pathway. However, the detailed mechanism of STP-C-mediated NF-kappaB activation has not been reported yet. We first report that STP-C interacts with TRAF6 protein in vivo and in vitro and further investigation shows that Glu(12) residue of STP-C is critical for binding to TRAF6. Introduction of ubiquitin together with STP-C augments NF-kappaB activity compared to that of STP-C expression alone. STP-C expression further induces ubiquitination of endogenous TRAF6. In addition, either a deubiquitination enzyme, CYLD or a dominant negative E2-conjugation enzyme reduced NF-kappaB activity in spite of the presence of STP-C, supporting that the interaction between STP-C and TRAF6 induces ubiquitination of TRAF6. NF-kappaB activation by STP-C through the ubiquitinated TRAF6 causes the increased production of IL-8, an inflammatory chemokine and the enhanced expression of costimulatory molecule ICAM, which might ultimately contribute cellular transformation by the exposure of HVS-infected cells with inflammatory microenvironment and chronic activation. PMID:17562285

Chung, Young-Hwa; Jhun, Byung Hak; Ryu, Su-Chak; Kim, Heui-Soo; Kim, Cheol-Min; Kim, Bong-Seok; Kim, Young-Ok; Lee, Sang Jun

2007-05-31

79

Artificial transmembrane oncoproteins smaller than the2 bovine papillomavirus E5 protein redefine sequence requirements3  

E-print Network

KTS 1 1 Artificial transmembrane oncoproteins smaller than the2 bovine papillomavirus E5 protein; bovine papillomavirus21 Word count: Abtract = 190; Text = 8,63722 * Corresponding author: Tel: 203.asm.orgDownloadedfrom #12;KTS 2 ABSTRACT24 The bovine papillomavirus E5 protein (BPV E5) is a 44-amino acid homodimeric25

Gerstein, Mark

80

Problem-Solving Test: The Mechanism of Action of a Human Papilloma Virus Oncoprotein  

ERIC Educational Resources Information Center

Terms to be familiar with before you start to solve the test: human papilloma virus; cervical cancer; oncoproteins; malignant transformation; retinoblastoma protein; cell cycle; quiescent and cycling cells; cyclin/cyclin-dependent kinase (Cdk) complexes; E2F; S-phase genes; enhancer element; proto-oncogenes; tumor suppressor genes; radioactive…

Szeberenyi, Jozsef

2009-01-01

81

Hepatitis C virus genotyping in relation to neu- oncoprotein overexpression and the development of hepatocellular carcinoma  

Microsoft Academic Search

The distribution of hepatitis C virus (HCV) genotypes among Egyptian patients positive for anti-HCV was determined and their influence, when combined with neu-oncoprotein overexpression, on the development of hepatocellular carcinoma (HCC) was examined. The study groups included asymptomatic carriers (ASC) and patients with chronic active hepatitis (CAH) and HCC. HCV genomes were detected in the sera of 27 ASC, 29

ABDEL-RAHMAN N. ZEKRI; ABEER A. BAHNASSY; SABRY M. SHAARAWY; A. MANSOURk; MOHAMED A. MADUAR; HUSSEIN M. KHALED; OMER EL-AHMADIk

82

NFKB1 Is a Direct Target of the TAL1 Oncoprotein in Human T Leukemia Cells  

E-print Network

NFKB1 Is a Direct Target of the TAL1 Oncoprotein in Human T Leukemia Cells Pei-Yun Chang, 1 Kyle Abstract We recently showed that a subset of human T acute lymphoblastic leukemia (T-ALL) cell lines in CEM T leukemia cells, basal NFKB1 expression is increased, and the levels of p65:cRel complex

Miyamoto, Shigeki

83

ERG oncoprotein expression in prostate carcinoma patients of different ethnicities.  

PubMed

Overexpression of the erythroblast transformation-specific-related gene (ERG) oncoprotein due to transmembrane protease, serine 2 (TMPRSS2)-ERG fusion, the most prevalent genomic alteration in prostate cancer (CaP), is more frequently observed among Caucasian patients compared to patients of African or Asian descent. To the best of our knowledge, this is the first study to investigate the prevalence of ERG alterations in a multiethnic cohort of CaP patients. A total of 191 formalin-fixed paraffin-embedded sections of transrectal ultrasound-guided prostate biopsy specimens, collected from 120 patients treated at the Sime Darby Medical Centre, Subang Jaya, Malaysia, were analyzed for ERG protein expression by immunohistochemistry using the anti-ERG monoclonal antibody 9FY as a surrogate for the detection of ERG fusion events. The overall frequency of ERG protein expression in the population evaluated in this study was 39.2%. Although seemingly similar to rates reported in other Asian communities, the expression of ERG was distinct amongst different ethnic groups (P=0.004). Malaysian Indian (MI) patients exhibited exceedingly high expression of ERG in their tumors, almost doubling that of Malaysian Chinese (MC) patients, whereas ERG expression was very low amongst Malay patients (12.5%). When collectively analyzing data, we observed a significant correlation between younger patients and higher ERG expression (P=0.04). The prevalence of ERG expression was significantly different amongst CaP patients of different ethnicities. The higher number of ERG-expressing tumors among MI patients suggested that the TMPRSS2-ERG fusion may be particularly important in the pathogenesis of CaP amongst this group of patients. Furthermore, the more frequent expression of ERG among the younger patients analyzed suggested an involvement of ERG in the early onset of CaP. The results of this study underline the value of using ERG status to better understand the differences in the etiology of CaP initiation and progression between ethnic groups. PMID:25469265

Kelly, Gregory M; Kong, Yink Heay; Dobi, Albert; Srivastava, Shiv; Sesterhenn, Isabell A; Pathmanathan, Rajadurai; Tan, Hui Meng; Tan, Shyh-Han; Cheong, Sok Ching

2015-01-01

84

Ubiquitination and degradation of the hominoid-specific oncoprotein TBC1D3 is regulated by protein palmitoylation  

SciTech Connect

Highlights: •Hominoid-specific oncogene TBC1D3 is targeted to plasma membrane by palmitoylation. •TBC1D3 is palmitoylated on two cysteine residues: 318 and 325. •TBC1D3 palmitoylation governs growth factors-induced TBC1D3 degradation. •Post-translational modifications may regulate oncogenic properties of TBC1D3. -- Abstract: Expression of the hominoid-specific oncoprotein TBC1D3 promotes enhanced cell growth and proliferation by increased activation of signal transduction through several growth factors. Recently we documented the role of CUL7 E3 ligase in growth factors-induced ubiquitination and degradation of TBC1D3. Here we expanded our study to discover additional molecular mechanisms that control TBC1D3 protein turnover. We report that TBC1D3 is palmitoylated on two cysteine residues: 318 and 325. The expression of double palmitoylation mutant TBC1D3:C318/325S resulted in protein mislocalization and enhanced growth factors-induced TBC1D3 degradation. Moreover, ubiquitination of TBC1D3 via CUL7 E3 ligase complex was increased by mutating the palmitoylation sites, suggesting that depalmitoylation of TBC1D3 makes the protein more available for ubiquitination and degradation. The results reported here provide novel insights into the molecular mechanisms that govern TBC1D3 protein degradation. Dysregulation of these mechanisms in vivo could potentially result in aberrant TBC1D3 expression and promote oncogenesis.

Kong, Chen; Lange, Jeffrey J.; Samovski, Dmitri [Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110 (United States)] [Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110 (United States); Su, Xiong [Department of Internal Medicine, Center for Human Nutrition Washington University School of Medicine, St. Louis, MO 63110 (United States)] [Department of Internal Medicine, Center for Human Nutrition Washington University School of Medicine, St. Louis, MO 63110 (United States); Liu, Jialiu [Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110 (United States)] [Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110 (United States); Sundaresan, Sinju [Department of Internal Medicine, Center for Human Nutrition Washington University School of Medicine, St. Louis, MO 63110 (United States)] [Department of Internal Medicine, Center for Human Nutrition Washington University School of Medicine, St. Louis, MO 63110 (United States); Stahl, Philip D., E-mail: pstahl@wustl.edu [Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110 (United States)

2013-05-03

85

Human papillomavirus (HPV) type 16 E7 protein bodies cause tumour regression in mice  

PubMed Central

Background Human papillomaviruses (HPV) are the causative agents of cervical cancer in women, which results in over 250 000 deaths per year. Presently there are two prophylactic vaccines on the market, protecting against the two most common high-risk HPV types 16 and 18. These vaccines remain very expensive and are not generally affordable in developing countries where they are needed most. Additionally, there remains a need to treat women that are already infected with HPV, and who have high-grade lesions or cervical cancer. Methods In this paper, we characterize the immunogenicity of a therapeutic vaccine that targets the E7 protein of the most prevalent high-risk HPV - type 16 – the gene which has previously been shown to be effective in DNA vaccine trials in mice. The synthetic shuffled HPV-16 E7 (16E7SH) has lost its transforming properties but retains all naturally-occurring CTL epitopes. This was genetically fused to Zera®, a self-assembly domain of the maize ?-zein able to induce the accumulation of recombinant proteins into protein bodies (PBs), within the endoplasmic reticulum in a number of expression systems. Results High-level expression of the HPV 16E7SH protein fused to Zera® in plants was achieved, and the protein bodies could be easily and cost-effectively purified. Immune responses comparable to the 16E7SH DNA vaccine were demonstrated in the murine model, with the protein vaccine successfully inducing a specific humoral as well as cell mediated immune response, and mediating tumour regression. Conclusions The fusion of 16E7SH to the Zera® peptide was found to enhance the immune responses, presumably by means of a more efficient antigen presentation via the protein bodies. Interestingly, simply mixing the free PBs and 16E7SH also enhanced immune responses, indicating an adjuvant activity for the Zera® PBs. PMID:24885328

2014-01-01

86

HER-2/neu (c-erbB-2) oncoprotein in hyperplastic endometrial polyps detected in two cats.  

PubMed

The presence of HER-2/neu (c-erbB-2) oncoprotein, oestrogen-alpha receptor (ER), and progesterone receptor (PR) in hyperplastic endometrial polyps (EPs) of two cats with cystic endometrial hyperplasia-pyometra (CEH-P) complex was investigated. Immunohistochemistry assay for ER, PR and c-erbB-2 oncoprotein in the glandular and stromal tissue of the EPs was performed. ER and c-erbB-2 immunoreactivity was observed in the glandular epithelium of the EPs whereas PR immunoreactivity was detected only in the stromal fibroblasts. The c-erbB-2 oncoprotein may play a role with the ER in the pathogenesis of the hyperplastic EPs, although the role of this oncoprotein in the pathogenesis of EPs has yet to be determined. PMID:19560383

Misirlioglu, Deniz; Nak, Deniz; Ozyigit, Musa Ozgur; Nak, Yavuz; Akkoc, Ahmet

2009-10-01

87

NF-kappaB activation by the viral oncoprotein StpC enhances IFN-gamma production in T cells.  

PubMed

Interferon-gamma (IFN-gamma) is an essential regulator of innate and adaptive immune responses and a hallmark of the Th1 T-cell subset. It is produced at high levels by human T lymphocytes upon transformation with Herpesvirus saimiri, which depends on the expression of the viral oncoproteins saimiri transformation-associated protein of subgroup C (StpC) and tyrosine kinase-interacting protein (Tip). Here, we show that IFN-gamma production was induced by Tip in Jurkat T cells. StpC by itself did not affect IFN-gamma expression, but enhanced the effect of Tip. Our results substantiated the findings that StpC induces NF-kappaB activation and demonstrated that other transcription factors, including NFAT, AP-1 and serum response element regulators, were not activated by StpC in unstimulated T cells. Studies using StpC mutants deficient in NF-kappaB activation, dominant negative IkappaBalpha and constitutively active IKK2, established the importance of NF-kappaB in StpC-mediated upregulation of IFN-gamma production. These observations suggest that NF-kappaB induction by StpC contributes to the Th1-like phenotype of virus-transformed human T cells. PMID:18560378

Glanz, Anja; Albrecht, Jens-Christian; Heinemann, Stefanie; Fleckenstein, Bernhard; Isakov, Noah; Biesinger, Brigitte

2008-10-01

88

Oncoprotein MDM2 is a ubiquitin ligase E3 for tumor suppressor p53  

Microsoft Academic Search

The tumor suppressor p53 is degraded by the ubiquitin-proteasome system. p53 was polyubiquitinated in the presence of E1, UbcH5 as E2 and MDM2 oncoprotein. A ubiquitin molecule bound MDM2 through sulfhydroxy bond which is characteristic of ubiquitin ligase (E3)-ubiquitin binding. The cysteine residue in the carboxyl terminus of MDM2 was essential for the activity. These data suggest that the MDM2

Reiko Honda; Hirofumi Tanaka; Hideyo Yasuda

1997-01-01

89

The adenovirus E1A oncoprotein recruits the cellular TRRAP\\/GCN5 histone acetyltransferase complex  

Microsoft Academic Search

The adenovirus E1A oncoprotein stimulates cell growth and inhibits differentiation by deregulating the normal transcription program via interaction with positive and negative cellular effectors. E1A associates with transcriptional regulatory complexes containing p400 and TRRAP involved in chromatin remodeling and decondensation. TRRAP is a component of three distinct human histone acetyltransferase (HAT) complexes: the TIP60 complex and complexes containing GCN5 or

Steven E Lang; Patrick Hearing

2003-01-01

90

Persistence of High-Grade Cervical Dysplasia and Cervical Cancer Requires the Continuous Expression of the Human Papillomavirus Type 16 E7 Oncogene  

PubMed Central

Several mucosotropic human papillomaviruses (HPV), including HPV type 16 (HPV-16), are etiologic agents of a subset of anogenital cancers and head and neck squamous cell carcinomas. In mice, HPV-16 E7 is the most potent of the papillomaviral oncogenes in the development of cervical disease. Furthermore, interfering specifically with the expression of E7 in HPV-positive cell lines derived from human cervical cancers inhibits their ability to proliferate, indicating that the expression of E7 is important in maintaining the transformed phenotype in vitro. To assess the temporal role of E7 in maintaining HPV-associated tumors and precancerous lesions in vivo, we generated Bi-L E7 transgenic mice that harbor a tetracycline-inducible transgene that expresses both HPV-16 E7 and firefly luciferase. When we crossed Bi-L E7 mice to a K5-tTA transgene-inducing line of mice, which expresses a tetracycline-responsive transactivator selectively in the stratified squamous epithelia, the resulting Bi-L E7/K5-tTA bitransgenic mice expressed E7 and luciferase in the skin and cervical epithelium, and doxycycline repressed this expression. Bitransgenic mice displayed several overt and acute epithelial phenotypes previously shown to be associated with the expression of E7, and these phenotypes were reversed on treatment with doxycycline. Repressing the expression of E7 caused the regression of high-grade cervical dysplasia and established cervical tumors, indicating that they depend on the continuous expression of E7 for their persistence. These results suggest that E7 is a relevant target not only for anticancer therapy but also for the treatment of HPV-positive dysplastic cervical lesions. PMID:19435895

Jabbar, Sean F.; Abrams, Linda; Glick, Adam; Lambert, Paul F.

2010-01-01

91

Control of alpha subunit of eukaryotic translation initiation factor 2 (eIF2 alpha) phosphorylation by the human papillomavirus type 18 E6 oncoprotein: implications for eIF2 alpha-dependent gene expression and cell death.  

PubMed

Phosphorylation of the alpha subunit of eukaryotic translation initiation factor 2 (eIF2alpha) at serine 51 inhibits protein synthesis in cells subjected to various forms of stress including virus infection. The human papillomavirus (HPV) E6 oncoprotein contributes to virus-induced pathogenicity through multiple mechanisms including the inhibition of apoptosis and the blockade of interferon (IFN) action. We have investigated a possible functional relationship between the E6 oncoprotein and eIF2alpha phosphorylation by an inducible-dimerization form of the IFN-inducible protein kinase PKR. Herein, we demonstrate that HPV type 18 E6 protein synthesis is rapidly repressed upon eIF2alpha phosphorylation caused by the conditional activation of the kinase. The remainder of E6, however, can rescue cells from PKR-mediated inhibition of protein synthesis and induction of apoptosis. E6 physically associates with GADD34/PP1 holophosphatase complex, which mediates translational recovery, and facilitates eIF2alpha dephosphorylation. Inhibition of eIF2alpha phosphorylation by E6 mitigates eIF2alpha-dependent responses to transcription and translation of proapoptotic genes. These findings demonstrate, for the first time, a role of the oncogenic E6 in apoptotic signaling induced by PKR and eIF2alpha phosphorylation. The functional interaction between E6 and the eIF2alpha phosphorylation pathway may have important implications for HPV infection and associated pathogenesis. PMID:15060162

Kazemi, Shirin; Papadopoulou, Stavroula; Li, Suiyang; Su, Qiaozhu; Wang, Shuo; Yoshimura, Akihiko; Matlashewski, Greg; Dever, Thomas E; Koromilas, Antonis E

2004-04-01

92

Molecular genetic characterization of p53 mutated oropharyngeal squamous cell carcinoma cells transformed with human papillomavirus E6 and E7 oncogenes  

PubMed Central

Patients with HPV-positive oropharyngeal cancer show better tumor response to radiation or chemotherapy than patients with HPV-negative cancer. HPV oncoprotein E6 binds and degrades a typically wild-type p53 protein product. However, HPV16 infection and p53 mutation infrequently coexist in a subset of HNSCCs. The purpose of this study was to investigate the mechanisms through which tumor biology and molecular genetic mechanisms change when two HPV-negative, p53-mutated oropharyngeal cell lines (YD8, non-disruptive p53 mutation; YD10B, disruptive p53 mutation) derived from patients with a history of heavy smoking are transfected with HPV E6 and E7 oncogenes in vitro. Transfection with HPV E6 and E7 oncogenes in YD8, reduced the abundance of proteins encoded by tumor suppressor genes, such as p-p53 and p-Rb. Cell proliferative activity was increased in the cells transfected with E6E7 compared to cells transfected with vector alone (P=0.09), whereas the invasiveness of E6E7-transfected cells was significantly reduced (P=0.02). cDNA microarray of the transfected cells with E6E7 showed significant changes in mRNA expression in several signaling pathways, including focal adhesion, JAK-STAT signaling pathway, cell cycle and p53 signaling pathway. Regarding the qPCR array for the p53 signaling pathway, the mRNA expression of STAT1 was remarkably upregulated by 6.47-fold (P<0.05); in contrast, IGF-1R was significantly downregulated by 2.40-fold in the YD8-vector compared toYD8-E6E7 (P<0.01). Finally, data collected from these two array experiments enabled us to select two genes, STAT1 and IGF-1R, for further study. In immunohistochemical study, nuclear STAT1 expression was slightly higher in HPV-positive compared to HPV-negative oropharyngeal tumors (P=0.18); however, cytoplasmic STAT1 was significantly lower in HPV-positive cases (P=0.03). IGF-1R expression levels were remarkably lower in HPV-positive compared to HPV-negative cases (P=0.01). Our data suggest that upregulated STAT1 and interferon signals by HPV16 E6 and E7 genes may play a major role in the relatively favorable prognosis for HPV-positive oropharyngeal squamous cell carcinoma cases with non-disruptive p53 mutations. PMID:23708675

OH, JI-EUN; KIM, JEONG-OH; SHIN, JUNG-YOUNG; ZHANG, XIANG-HUA; WON, HYE-SUNG; CHUN, SANG-HOON; JUNG, CHAN-KWON; PARK, WON-SANG; NAM, SUK-WOO; EUN, JUNG-WOO; KANG, JIN-HYOUNG

2013-01-01

93

The Human Papillomavirus E7 Proteins Associate with p190RhoGAP and Alter Its Function  

PubMed Central

ABSTRACT Using mass spectrometry, we identified p190RhoGAP (p190) as a binding partner of human papillomavirus 16 (HPV16) E7. p190 belongs to the GTPase activating protein (GAP) family and is one of the primary GAPs for RhoA. GAPs stimulate the intrinsic GTPase activity of the Rho proteins, leading to Rho inactivation and influencing numerous biological processes. RhoA is one of the best-characterized Rho proteins and is specifically involved in formation of focal adhesions and stress fibers, thereby regulating cell migration and cell spreading. Since this is the first report that E7 associates with p190, we carried out detailed interaction studies. We show that E7 proteins from other HPV types also bind p190. Furthermore, we found that conserved region 3 (CR3) of E7 and the middle domain of p190 are important for this interaction. More specifically, we identified two residues in CR3 of E7 that are necessary for p190 binding and used mutants of E7 with mutations of these residues to determine the biological consequences of the E7-p190 interaction. Our data suggest that the interaction of E7 with p190 dysregulates this GAP and alters the actin cytoskeleton. We also found that this interaction negatively regulates cell spreading on a fibronectin substrate and therefore likely contributes to important aspects of the HPV life cycle or HPV-induced tumorigenesis. IMPORTANCE This study identifies p190RhoGAP as a novel cellular binding partner for the human papillomavirus (HPV) E7 protein. Our study shows that a large number of different HPV E7 proteins bind p190RhoGAP, and it identifies regions in both E7 and p190RhoGAP which are important for the interaction to occur. This study also highlights the likelihood that the E7-p190RhoGAP interaction may have important biological consequences related to actin organization in the infected cell. These changes could be an important contributor to the viral life cycle and during progression to cancer in HPV-infected cells. Importantly, this work also emphasizes the need for further study in a field which has largely been unexplored as it relates to the HPV life cycle and HPV-induced transformation. PMID:24403595

Todorovic, Biljana; Nichols, Anthony C.; Chitilian, Jennifer M.; Myers, Michael P.; Shepherd, Trevor G.; Parsons, Sarah J.; Barrett, John W.; Banks, Lawrence

2014-01-01

94

Detection of transcriptionally active high-risk HPV in patients with head and neck squamous cell carcinoma as visualized by a novel E6/E7 mRNA in situ hybridization method.  

PubMed

Evidence for transcriptional activation of the viral oncoproteins E6 and E7 is regarded as the gold standard for the presence of clinically relevant human papillomavirus (HPV), but detection of E6/E7 mRNA requires RNA extraction and polymerase chain reaction amplification-a challenging technique that is restricted to the research laboratory. The development of RNA in situ hybridization (ISH) probes complementary to E6/E7 mRNA permits direct visualization of viral transcripts in routinely processed tissues and has opened the door for accurate HPV detection in the clinical care setting. Tissue microarrays containing 282 head and neck squamous cell carcinomas from various anatomic subsites were tested for the presence of HPV using p16 immunohistochemistry, HPV DNA ISH, and an RNA ISH assay (RNAscope) targeting high-risk HPV E6/E7 mRNA transcripts. The E6/E7 mRNA assay was also used to test an additional 25 oropharyngeal carcinomas in which the HPV status as recorded in the surgical pathology reports was equivocal due to conflicting detection results (ie, p16 positive, DNA ISH negative). By the E6/E7 mRNA method, HPV was detected in 49 of 282 (17%) HNSCCs including 43 of 77 (56%) carcinomas from the oropharynx, 2 of 3 (67%) metastatic HNSCCs of an unknown primary site, 2 of 7 (29%) carcinomas from the sinonasal tract, and 2 of 195 (1%) carcinomas from other head and neck sites. p16 expression was strongly associated with the presence of HPV E6/E7 mRNA: 46 of 49 HPV-positive tumors exhibited p16 expression, whereas only 22 of 233 HPV-negative tumors were p16 positive (94% vs. 9%, P<0.0001). There was also a high rate of concordance (99%) between the E6/E7 mRNA method and HPV DNA ISH. For the selected group of discordant HNSCCs (p16/HPV DNA), the presence of E6/E7 transcripts was detected in 21 of 25 (84%) cases. The E6/E7 mRNA method confirmed the presence of transcriptionally active HPV-related HNSCC that has a strong predilection for the oropharynx and is strongly associated with high levels of p16 expression. Testing for HPV E6/E7 transcripts by RNA ISH is ideal because it confirms the presence of integrated and transcriptionally active virus, permits visualization of viral transcripts in tissues, and is technically feasible for routine testing in the clinical laboratory. PMID:23060353

Bishop, Justin A; Ma, Xiao-Jun; Wang, Hongwei; Luo, Yuling; Illei, Peter B; Begum, Shanaz; Taube, Janis M; Koch, Wayne M; Westra, William H

2012-12-01

95

Detection of transcriptionally active high risk HPV in patients with head and neck squamous cell carcinoma as visualized by a novel E6/E7 mRNA in situ hybridization method  

PubMed Central

Background Evidence for transcriptional activation of the viral oncoproteins E6 and E7 is regarded as the gold standard for the presence of clinically relevant human papillomavirus (HPV), but detection of E6/E7 mRNA requires RNA extraction and PCR amplification - a challenging technique that is restricted to the research laboratory. The development of RNA in-situ hybridization (ISH) probes complementary to E6/E7 mRNA permits direct visualization of viral transcripts in routinely processed tissues and has opened the door for accurate HPV detection in the clinical care setting. Methods Tissue microarrays (TMAs) containing 282 head and neck squamous cell carcinomas (HNSCCs) from various anatomic subsites were tested for the presence of HPV using p16 immunohistochemistry, HPV DNA ISH, and a RNA ISH assay (RNAscope®) targeting high risk HPV E6/E7 mRNA transcripts. The E6/E7 mRNA assay was also used to test an additional 25 oropharyngeal carcinomas where HPV status as recorded in the surgical pathology reports was equivocal due to conflicting detection results (i.e. p16 positive, DNA ISH negative). Results By the E6/E7 mRNA method, HPV was detected in 49 of 282 (17%) HNSCCs including 43 of 77 (56%) carcinomas from the oropharynx, 2 of 3 (67%) metastatic HNSCCs of unknown primary site, 2 of 7 (29%) carcinomas from the sinonasal tract, and 2 of 195 (1%) carcinomas from other head and neck sites. P16 expression was strongly associated with the presence of HPV E6/E7 mRNA: 46 of 49 HPV positive tumors exhibited p16 expression, whereas only 22 of 233 HPV negative tumors were p16 positive (94% versus 9%, p < .0001). There was also a high rate of concordance (99%) between the E6/E7 mRNA method and HPV DNA ISH. For the selected group of discordant HNSCCs (p16+/HPV DNA-), the presence of E6/E7 transcripts was detected in 21 of 25 (84%) cases. Conclusions The E6/E7 mRNA method confirmed the presence of transcriptionally active HPV-related HNSCC that has a strong predilection for the oropharynx and is strongly associated with high levels of p16 expression. Testing for HPV E6/E7 transcripts by RNA ISH is ideal because it confirms the presence of integrated and transcriptionally active virus, permits visualization of viral transcripts in tissues, and is technically feasible for routine testing in the clinical laboratory. PMID:23060353

Bishop, JA; Ma, X-J; Wang, H; Luo, Y; Illei, PB; Begum, S; Taube, JM; Koch, WM; Westra, WH

2012-01-01

96

Direct Binding of the N-Terminus of HTLV-1 Tax Oncoprotein to Cyclin-Dependent Kinase 4 Is a Dominant Path To Stimulate the Kinase Activity  

E-print Network

Direct Binding of the N-Terminus of HTLV-1 Tax Oncoprotein to Cyclin-Dependent Kinase 4 for immortalization and transformation of human T-cell leukemia virus 1 (HTLV-1) infected cells. In both p16 oncoprotein in HTLV-1 infected cells. Our current understanding of cell cycle control in eukary- otes

Tsai, Ming-Daw

97

Oct4 Is Required ?E7.5 for Proliferation in the Primitive Streak  

PubMed Central

Oct4 is a widely recognized pluripotency factor as it maintains Embryonic Stem (ES) cells in a pluripotent state, and, in vivo, prevents the inner cell mass (ICM) in murine embryos from differentiating into trophectoderm. However, its function in somatic tissue after this developmental stage is not well characterized. Using a tamoxifen-inducible Cre recombinase and floxed alleles of Oct4, we investigated the effect of depleting Oct4 in mouse embryos between the pre-streak and headfold stages, ?E6.0–E8.0, when Oct4 is found in dynamic patterns throughout the embryonic compartment of the mouse egg cylinder. We found that depletion of Oct4 ?E7.5 resulted in a severe phenotype, comprised of craniorachischisis, random heart tube orientation, failed turning, defective somitogenesis and posterior truncation. Unlike in ES cells, depletion of the pluripotency factors Sox2 and Oct4 after E7.0 does not phenocopy, suggesting that ?E7.5 Oct4 is required within a network that is altered relative to the pluripotency network. Oct4 is not required in extraembryonic tissue for these processes, but is required to maintain cell viability in the embryo and normal proliferation within the primitive streak. Impaired expansion of the primitive streak occurs coincident with Oct4 depletion ?E7.5 and precedes deficient convergent extension which contributes to several aspects of the phenotype. PMID:24244203

DeVeale, Brian; Brokhman, Irina; Mohseni, Paria; Babak, Tomas; Yoon, Charles; Lin, Anthony; Onishi, Kento; Tomilin, Alexey; Pevny, Larysa; Zandstra, Peter W.; Nagy, Andras; van der Kooy, Derek

2013-01-01

98

Polo-like kinase 4 transcription is activated via CRE and NRF1 elements, repressed by DREAM through CDE/CHR sites and deregulated by HPV E7 protein  

PubMed Central

Infection by oncogenic viruses is a frequent cause for tumor formation as observed in cervical cancer. Viral oncoproteins cause inactivation of p53 function and false transcriptional regulation of central cell cycle genes. Here we analyze the regulation of Plk4, serving as an example of many cell cycle- and p53-regulated genes. Cell cycle genes are often repressed via CDE and CHR elements in their promoters and activated by NF-Y binding to CCAAT-boxes. In contrast, general activation of Plk4 depends on NRF1 and CRE sites. Bioinformatic analyses imply that NRF1 and CRE are central elements of the transcriptional network controlling cell cycle genes. We identify CDE and CHR sites in the Plk4 promoter, which are necessary for binding of the DREAM (DP, RB-like, E2F4 and MuvB) complex and for mediating repression in G0/G1. When cells progress to G2 and mitosis, DREAM is replaced by the MMB (Myb-MuvB) complex that only requires the CHR element for binding. Plk4 expression is downregulated by the p53-p21WAF1/CIP1-DREAM signaling pathway through the CDE and CHR sites. Cell cycle- and p53-dependent repression is abrogated by HPV E7 oncoprotein. Together with genome-wide analyses our results imply that many cell cycle genes upregulated in tumors by viral infection are bound by DREAM through CDE/CHR sites. PMID:24071582

Fischer, Martin; Quaas, Marianne; Wintsche, Axel; Müller, Gerd A.; Engeland, Kurt

2014-01-01

99

Control of Cervicovaginal HPV-16 E7-Expressing Tumors by the Combination of Therapeutic HPV Vaccination and Vascular Disrupting Agents  

PubMed Central

Abstract Antigen-specific immunotherapy and vascular disrupting agents, such as 5,6-dimethylxanthenone-4-acetic acid (DMXAA), have emerged as attractive approaches for the treatment of cancers. In the current study, we tested the combination of DMXAA treatment with therapeutic human papillomavirus type 16 (HPV-16) E7 peptide-based vaccination for their ability to generate E7-specific CD8+ T-cell immune responses, as well as their ability to control E7-expressing tumors in a subcutaneous and a cervicovaginal tumor model. We found that the combination of DMXAA treatment with E7 long peptide (amino acids 43–62) vaccination mixed with polyriboinosinic:polyribocytidylic generated significantly stronger E7-specific CD8+ T-cell immune responses and antitumor effects compared with treatment with DMXAA alone or HPV peptide vaccination alone in the subcutaneous model. Additionally, we found that the DMXAA-mediated enhancement of E7-specific CD8+ T-cell immune responses generated by the therapeutic HPV peptide-based vaccine was dependent on the timing of administration of DMXAA. Treatment with DMXAA in tumor-bearing mice was also shown to lead to increased dendritic cell maturation and increased production of inflammatory cytokines in the tumor. Furthermore, we observed that the combination of DMXAA with HPV-16 E7 peptide vaccination generated a significant enhancement in the antitumor effects in the cervicovaginal TC-1 tumor growth model, which closely resembles the tumor microenvironment of cervical cancer. Taken together, our data demonstrated that administration of the vascular disrupting agent, DMXAA, enhances therapeutic HPV vaccine-induced cytotoxic T-lymphocyte responses and antitumor effects against E7-expressing tumors in two different locations. Our study has significant implications for future clinical translation. PMID:21128743

Zeng, Qi; Peng, Shiwen; Monie, Archana; Yang, Ming; Pang, Xiaowu; Hung, Chien-Fu

2011-01-01

100

Elucidating Molecular Interactions of Natural Inhibitors with HPV-16 E6 Oncoprotein through Docking Analysis  

PubMed Central

Human papillomavirus (HPV) infection is the leading cause of cancer mortality among women worldwide. The life-threatening infection caused by HPV demands the need for designing anticancerous drugs. In the recent years, different compounds from natural origins, such as carrageenan, curcumin, epigallocatechin gallate, indole-3-carbinol, jaceosidin, and withaferin, have been used as a hopeful source of anticancer therapy. These compounds have been shown to suppress HPV infection by different researchers. In the present study, we explored these natural inhibitors against E6 oncoprotein of high-risk HPV-16, which is known to inactivate the p53 tumor suppressor protein. A robust homology model of HPV-16 E6 was built to anticipate the interaction mechanism of E6 oncoprotein with natural inhibitory molecules using a structure-based drug designing approach. Docking analysis showed the interaction of these natural compounds with the p53-binding site of E6 protein residues 113-122 (CQKPLCPEEK) and helped the restoration of p53 functioning. Docking analysis, besides helping in silico validation of natural compounds, also helps understand molecular mechanisms of protein-ligand interactions. PMID:25031569

Jena, Lingaraja; Galande, Sneha; Daf, Sangeeta; Mohod, Kanchan; Varma, Ashok K.

2014-01-01

101

Tyrosine phosphorylation of the Tio oncoprotein is essential for transformation of primary human T cells.  

PubMed

Human T cells are transformed to antigen-independent permanent growth in vitro upon infection with herpesvirus saimiri subgroup C strains. The viral oncoproteins required for this process, StpC and Tip, could be replaced by Tio, the oncoprotein of herpesvirus ateles. Here we demonstrate that proliferation of lymphocytes transformed with Tio-recombinant herpesvirus saimiri required the activity of Src family kinases. Src kinases had previously been identified as interaction partners of Tio. This interaction was now shown to be independent of any of the four tyrosine residues of Tio but to be dependent on an SH3-binding motif. Mutations within this motif abrogated the transforming capabilities of Tio-recombinant herpesvirus saimiri. Furthermore, kinase interaction resulted in the phosphorylation of Tio on a single tyrosine residue at position 136. Mutation of this residue in the viral context revealed that this phosphorylation site, but none of the other tyrosine residues, was required for T-cell transformation. These data indicate that the interaction of Tio with a Src kinase is essential for both the initiation and the maintenance of T-cell transformation by recombinant herpesvirus saimiri. The requirement for the tyrosine phosphorylation site at position 136 suggests a role for Tio beyond simple deregulation of the kinase. PMID:16051843

Albrecht, Jens-Christian; Müller-Fleckenstein, Ingrid; Schmidt, Monika; Fleckenstein, Bernhard; Biesinger, Brigitte

2005-08-01

102

Tyrosine Phosphorylation of the Tio Oncoprotein Is Essential for Transformation of Primary Human T Cells  

PubMed Central

Human T cells are transformed to antigen-independent permanent growth in vitro upon infection with herpesvirus saimiri subgroup C strains. The viral oncoproteins required for this process, StpC and Tip, could be replaced by Tio, the oncoprotein of herpesvirus ateles. Here we demonstrate that proliferation of lymphocytes transformed with Tio-recombinant herpesvirus saimiri required the activity of Src family kinases. Src kinases had previously been identified as interaction partners of Tio. This interaction was now shown to be independent of any of the four tyrosine residues of Tio but to be dependent on an SH3-binding motif. Mutations within this motif abrogated the transforming capabilities of Tio-recombinant herpesvirus saimiri. Furthermore, kinase interaction resulted in the phosphorylation of Tio on a single tyrosine residue at position 136. Mutation of this residue in the viral context revealed that this phosphorylation site, but none of the other tyrosine residues, was required for T-cell transformation. These data indicate that the interaction of Tio with a Src kinase is essential for both the initiation and the maintenance of T-cell transformation by recombinant herpesvirus saimiri. The requirement for the tyrosine phosphorylation site at position 136 suggests a role for Tio beyond simple deregulation of the kinase. PMID:16051843

Albrecht, Jens-Christian; Müller-Fleckenstein, Ingrid; Schmidt, Monika; Fleckenstein, Bernhard; Biesinger, Brigitte

2005-01-01

103

Preferential nuclear localization of the human papillomavirus type 16 E6 oncoprotein in cervical carcinoma cells.  

PubMed

The E6 protein of the high-risk human papillomavirus type 16 (HPV-16) is involved in the tumorigenesis of human cervical cells by targeting numerous cellular proteins. We characterized new anti-E6 monoclonal antibodies and used them for precise localization of the E6 oncoprotein within carcinoma cells. Overexpressed E6 protein was predominantly detected in the nucleus of transiently transfected HaCaT cells. While mostly localized at the periphery of condensed chromatin, E6 was also associated with nuclear ribonucleoproteic ultrastructures and with some ribosomal areas in the cytoplasm of SiHa and CaSki cells. The chimeric beta-galactosidase-E6 protein expressed in transfected HeLa cells was essentially localized in the nuclear compartment. Together, these data indicate that the E6 sequence of HPV-16 may encode a nuclear localization signal. The preferential nuclear distribution of this viral oncoprotein in HPV-transformed cells correlates with its activities at the transcriptional level. PMID:12867640

Masson, Murielle; Hindelang, Colette; Sibler, Annie-Paule; Schwalbach, Georges; Travé, Gilles; Weiss, Etienne

2003-08-01

104

Elucidating Molecular Interactions of Natural Inhibitors with HPV-16 E6 Oncoprotein through Docking Analysis.  

PubMed

Human papillomavirus (HPV) infection is the leading cause of cancer mortality among women worldwide. The life-threatening infection caused by HPV demands the need for designing anticancerous drugs. In the recent years, different compounds from natural origins, such as carrageenan, curcumin, epigallocatechin gallate, indole-3-carbinol, jaceosidin, and withaferin, have been used as a hopeful source of anticancer therapy. These compounds have been shown to suppress HPV infection by different researchers. In the present study, we explored these natural inhibitors against E6 oncoprotein of high-risk HPV-16, which is known to inactivate the p53 tumor suppressor protein. A robust homology model of HPV-16 E6 was built to anticipate the interaction mechanism of E6 oncoprotein with natural inhibitory molecules using a structure-based drug designing approach. Docking analysis showed the interaction of these natural compounds with the p53-binding site of E6 protein residues 113-122 (CQKPLCPEEK) and helped the restoration of p53 functioning. Docking analysis, besides helping in silico validation of natural compounds, also helps understand molecular mechanisms of protein-ligand interactions. PMID:25031569

Kumar, Satish; Jena, Lingaraja; Galande, Sneha; Daf, Sangeeta; Mohod, Kanchan; Varma, Ashok K

2014-06-01

105

Phosphatidylinositol 3-kinase (PI3K): The Oncoprotein  

PubMed Central

The catalytic and regulatory subunits of class I phosphoinositide 3-kinase (PI3K) have oncogenic potential. The catalytic subunit p110? and the regulatory subunit p85 undergo cancer-specific gain-of-function mutations that lead to enhanced enzymatic activity, ability to signal constitutively and oncogenicity. The ?, ? and ? isoforms of p110 are cell-transforming as overexpressed wild-type proteins. Class I PI3Ks have the unique ability to generate phosphoinositide 3,4,5 trisphosphate (PIP3). Class II and class III PI3Ks lack this ability. Genetic and cell biological evidence suggests that PIP3 is essential for PI3K-mediated oncogenicity, explaining why class II and class III enzymes have not been linked to cancer. Mutational analysis reveals the existence of at least two distinct molecular mechanisms for the gain of function seen with cancer-specific mutations in p110?, one causing independence from upstream receptor tyrosine kinases, the other inducing independence from Ras. An essential component of the oncogenic signal that is initiated by PI3K is the TOR (target of rapamycin) kinase. TOR is an integrator of growth and of metabolic inputs. In complex with the raptor protein (TORC1), it controls cap-dependent translation, and this function is essential for PI3K-initiated oncogenesis. PMID:20582532

Vogt, Peter K.; Hart, Jonathan R.; Gymnopoulos, Marco; Jiang, Hao; Kang, Sohye; Bader, Andreas G.; Zhao, Li; Denley, Adam

2010-01-01

106

E6 and E7 of human papillomavirus type 18 and UVB irradiation corporately regulate interleukin-6 and interleukin-8 expressions in basal cell carcinoma.  

PubMed

The lack of a human papillomavirus (HPV)-infected skin cancer cell line has hampered the investigation of the interaction of UV and HPV in skin carcinogenesis. We identified a human basal cell carcinoma (BCC-1/KMC) cell line integrated with E6 and E7 genes of high-risk HPV type 18 and demonstrated that repression of E6 and E7 results in proliferation inhibition. Sublethal ultraviolet-B (UVB) irradiation induced the expressions of interleukin-6 (IL-6) and interleukin-8 (IL-8), as well as viral E6 and E7 genes, in BCC-1/KMC cells. When E6 and E7 expressions were inhibited, IL-6/IL-8 expressions were repressed. Furthermore, IL-6/IL-8 remained inducible by UVB irradiation when E6 and E7 were inhibited. These results indicated that IL-6 and IL-8 can be upregulated by viral E6 and E7 proteins without UVB irradiation. Moreover, chronic exposure to UVB upregulates IL-6 and IL-8 when E6/E7 is induced by UVB. PMID:24079741

Hsiao, Yu-Ping; Yang, Jen-Hung; Wu, Wen-Jun; Lin, Meng-Hsuan; Sheu, Gwo-Tarng

2013-10-01

107

Intracellular scFvs against the viral E6 oncoprotein provoke apoptosis in human papillomavirus-positive cancer cells  

E-print Network

Intracellular scFvs against the viral E6 oncoprotein provoke apoptosis in human papillomavirus : 10.1016/j.bbrc.2007.07.040 #12;ABSTRACT The E6 protein of Human papillomavirus type 16 (16E6 infection with high-risk human papillomaviruses (HPVs) [1]. Epidemiological studies have demonstrated

Paris-Sud XI, Université de

108

int. j. radiat. biol 2001, vol. 77, no. 1, 31 40 Oncoprotein expression in human breast epithelial cells  

E-print Network

cells transformed by high-LET radiation G. CALAF* and T. K. HEI (Received 24 March 2000; accepted 13 of oncoproteins that are frequently altered in breast ing of the natural history of breast tumors. These cancer staining coupled with confocal microscopy tion, i.e. deregulated proliferation and invasion. in transformed

109

COX-2/PGE2: molecular ambassadors of Kaposi's sarcoma-associated herpes virus oncoprotein-v-FLIP.  

PubMed

Kaposi's sarcoma herpesvirus (KSHV) latent oncoprotein viral FLICE (FADD-like interferon converting enzyme)-like inhibitory protein (v-FLIP) or K13, a potent activator of NF-?B, has well-established roles in KSHV latency and oncogenesis. KSHV-induced COX-2 represents a novel strategy employed by KSHV to promote latency and inflammation/angiogenesis/invasion. Here, we demonstrate that v-FLIP/K13 promotes tumorigenic effects via the induction of host protein COX-2 and its inflammatory metabolite PGE2 in an NF-?B-dependent manner. In addition to our previous studies demonstrating COX-2/PGE2's role in transcriptional regulation of KSHV latency promoter and latent gene expression, the current study adds to the complexity that though LANA-1 (latency associated nuclear antigen) is utilizing COX-2/PGE2 as critical factors for its transcriptional regulation, it is the v-FLIP/K13 gene in the KSHV latency cluster that maintains continuous COX-2/PGE2 levels in the infected cells. We demonstrate that COX-2 inhibition, via its chemical inhibitors (NS-398 or celecoxib), reduced v-FLIP/K13-mediated NF-?B induction, and extracellular matrix (ECM) interaction-mediated signaling, mitochondrial antioxidant enzyme manganese superoxide dismutase (MnSOD) levels, and subsequently downregulated detachment-induced apoptosis (anoikis) resistance. vFLIP expression mediated the secretion of cytokines, and spindle cell differentiation activated the phosphorylation of p38, RSK, FAK, Src, Akt and Rac1-GTPase. The COX-2 inhibition in v-FLIP/K13-HMVECs reduced inflammation and invasion/metastasis-related genes, along with reduced anchorage-independent colony formation via modulating 'extrinsic' as well as 'intrinsic' cell death pathways. COX-2 blockade in v-FLIP/K13-HMVEC cells drastically augmented cell death induced by removal of essential growth/survival factors secreted in the microenvironment. Transformed cells obtained from anchorage-independent colonies of COX-2 inhibitor-treated v-FLIP/K13-HMVEC cells expressed lower levels of endothelial-mesenchymal transition genes such as slug, snail and twist, and higher expression of the tumor-suppressor gene, E-cadherin. Taken together, our study provides strong evidences that FDA-approved COX-2 inhibitors have great potential in blocking tumorigenic events linked to KSHV's oncogenic protein v-FLIP/K13. PMID:23552603

Sharma-Walia, N; Patel, K; Chandran, K; Marginean, A; Bottero, V; Kerur, N; Paul, A G

2012-01-01

110

An RNA Aptamer Targets the PDZ-Binding Motif of the HPV16 E6 Oncoprotein  

PubMed Central

Human papillomavirus 16 (HPV16) is a high-risk DNA tumour virus which is the primary causative agent of cervical cancer. Cell transformation arises from deregulated expression of the E6 and E7 oncogenes. E6 has been shown to bind a number of cellular proteins, including p53 and proteins containing a PDZ domain. This study reports the first RNA aptamers to E6. These have been employed as molecular tools to further investigate E6-p53 and E6-PDZ interactions. This study is focussed on two aptamers (termed F2 and F4) which induced apoptosis in cells derived from an HPV16-transformed cervical carcinoma. The molecules were able to inhibit the interaction between E6 and PDZ1 from Magi1, with F2 being the most effective inhibitor. Neither of the aptamers inhibited E6-p53 interaction or p53 degradation. This study shows the specificity of this approach and highlights the potential benefits of the E6 aptamers as potential therapeutic or diagnostic agents in the future. PMID:25062098

Belyaeva, Tamara A.; Nicol, Clare; Cesur, Özlem; Travé, Gilles; Blair, George Eric; Stonehouse, Nicola J.

2014-01-01

111

NF-?B-mediated transcriptional upregulation of TNFAIP2 by the Epstein-Barr virus oncoprotein, LMP1, promotes cell motility in nasopharyngeal carcinoma.  

PubMed

Nasopharyngeal carcinoma (NPC), which is closely associated with Epstein-Barr virus (EBV), is a metastasis-prone epithelial cancer. We previously showed that tumor necrosis factor ?-induced protein 2 (TNFAIP2) is highly expressed in NPC tumor tissues and is correlated with metastasis and poor survival in NPC patients. However, the underlying mechanism remains unclear. In this study, we demonstrate that the EBV oncoprotein, latent membrane protein 1 (LMP1), can transcriptionally induce TNFAIP2 expression via NF-?B. Quantitative RT-PCR and western blotting revealed that LMP1 induces TNFAIP2 expression through its C-terminal-activating region (CTAR2) domain, which is required for transduction of NF-?B (nuclear factor kappa-light-chain-enhancer of activated B cells) signaling. Inhibition of NF-?B activation or depletion of p65 (a component of NF-?B) by RNA interference abolished the LMP1-induced expression of TNFAIP2, whereas ectopic expression of p65 was sufficient to induce TNFAIP2 expression. Luciferase reporter assays showed that LMP1 transcriptionally induces TNFAIP2 expression through a newly identified NF-?B-binding site within the TNFAIP2 promoter (-3,869 to -3,860?bp). Immunohistochemical analysis of NPC biopsy specimens further revealed a significant correlation between the protein levels of TNFAIP2 and activated p65 (R=0.689, P<0.001), indicating that our findings are clinically relevant. Immunofluorescence microscopy and co-immunoprecipitation assays showed that TNFAIP2 associates with actin and is involved in the formation of actin-based membrane protrusions. Furthermore, transwell migration assays demonstrated that TNFAIP2 contributes to LMP1-induced cell motility. Collectively, these findings provide novel insights into the regulation of TNFAIP2 and its role in promoting NPC tumor progression. PMID:23975427

Chen, C-C; Liu, H-P; Chao, M; Liang, Y; Tsang, N-M; Huang, H-Y; Wu, C-C; Chang, Y-S

2014-07-10

112

Therapeutic DNA vaccination against colorectal cancer by targeting the MYB oncoprotein  

PubMed Central

Cancers can be addicted to continued and relatively high expression of nuclear oncoproteins. This is evident in colorectal cancer (CRC) where the oncoprotein and transcription factor MYB is over expressed and essential to continued proliferation and tumour cell survival. Historically, targeting transcription factors in the context of cancer has been very challenging. Nevertheless, we formulated a DNA vaccine to generate a MYB-specific immune response in the belief MYB peptides might be aberrantly presented on the cell surface of CRC cells. MYB, like many tumour antigens, is weakly immunogenic as it is a ‘self' antigen and is subject to tolerance. To break tolerance, a fusion vaccine was generated comprising a full-length MYB complementary DNA (cDNA) flanked by two potent CD4-epitopes derived from tetanus toxoid. Vaccination was achieved against tumours initiated by two distinct highly aggressive, syngeneic cancer cell lines (CT26 and MC38) that express MYB. This was done in BALB/c and C57BL/6 mouse strains respectively. We introduced multiple inactivating mutations into the oncogene sequence for safety and sub-cloned the cDNA into a Food and Drug Administration (FDA)-compliant vector. We used low dose cyclophosphamide (CY) to overcome T-regulatory cell immune suppression, and anti-program cell death receptor 1 (anti-PD-1) antibodies to block T-cell exhaustion. Anti-PD-1 administered alone slightly delayed tumour growth in MC38 and more effectively in CT26 bearing mice, while CY treatment alone did not. We found that therapeutic vaccination elicits protection when MC38 tumour burden is low, mounts tumour-specific cell killing and affords enhanced protection when MC38 and CT26 tumour burden is higher but only in combination with anti-PD-1 antibody or low dose CY, respectively.

Cross, Ryan S; Malaterre, Jordane; Davenport, Alexander J; Carpinteri, Sandra; Anderson, Robin L; Darcy, Phillip K; Ramsay, Robert G

2015-01-01

113

Therapeutic DNA vaccination against colorectal cancer by targeting the MYB oncoprotein.  

PubMed

Cancers can be addicted to continued and relatively high expression of nuclear oncoproteins. This is evident in colorectal cancer (CRC) where the oncoprotein and transcription factor MYB is over expressed and essential to continued proliferation and tumour cell survival. Historically, targeting transcription factors in the context of cancer has been very challenging. Nevertheless, we formulated a DNA vaccine to generate a MYB-specific immune response in the belief MYB peptides might be aberrantly presented on the cell surface of CRC cells. MYB, like many tumour antigens, is weakly immunogenic as it is a 'self' antigen and is subject to tolerance. To break tolerance, a fusion vaccine was generated comprising a full-length MYB complementary DNA (cDNA) flanked by two potent CD4-epitopes derived from tetanus toxoid. Vaccination was achieved against tumours initiated by two distinct highly aggressive, syngeneic cancer cell lines (CT26 and MC38) that express MYB. This was done in BALB/c and C57BL/6 mouse strains respectively. We introduced multiple inactivating mutations into the oncogene sequence for safety and sub-cloned the cDNA into a Food and Drug Administration (FDA)-compliant vector. We used low dose cyclophosphamide (CY) to overcome T-regulatory cell immune suppression, and anti-program cell death receptor 1 (anti-PD-1) antibodies to block T-cell exhaustion. Anti-PD-1 administered alone slightly delayed tumour growth in MC38 and more effectively in CT26 bearing mice, while CY treatment alone did not. We found that therapeutic vaccination elicits protection when MC38 tumour burden is low, mounts tumour-specific cell killing and affords enhanced protection when MC38 and CT26 tumour burden is higher but only in combination with anti-PD-1 antibody or low dose CY, respectively. PMID:25671128

Cross, Ryan S; Malaterre, Jordane; Davenport, Alexander J; Carpinteri, Sandra; Anderson, Robin L; Darcy, Phillip K; Ramsay, Robert G

2015-01-01

114

N=8 Counterterms and E7(7) Current Conservation  

E-print Network

We examine conservation of the E7(7) Noether-Gaillard-Zumino current in the presence of N=8 supergravity counterterms using the momentum space helicity formalism, which significantly simplifies the calculations. The main result is that the 4-point counterterms at any loop order L are forbidden by the E7(7) current conservation identity. We also clarify the relation between linearized and full non-linear superinvariants as candidate counterterms. This enables us to show that all n-point counterterms at L=7, 8 are forbidden since they provide a non-linear completions of the 4-point ones. This supports and exemplifies our general proof in arXiv:1103.4115 of perturbative UV finiteness of N=8 supergravity.

Renata Kallosh

2011-04-28

115

Phase Properties of Hexanedioldiacrylate\\/E7 Blends  

Microsoft Academic Search

Equilibrium phase diagrams of uncured and UV-cured difunctional hexanedioldiacrylate and the eutectic mixture of low molecular weight liquid crystals E7 are established by polarized optical microscopy and differential scanning calorimetry. Data are analyzed using the Maier-Saupe model of nematic order. In the case of the uncured system the Flory-Huggins free energy of isotropic mixing is applied while for the cured

F. Roussel; U. Maschke; J.-M. Buisine; X. Coqueret; F. Benmouna

2001-01-01

116

Plant Ecology VolumE 7, NumbEr 1,  

E-print Network

Journal of Plant Ecology VolumE 7, NumbEr 1, PagEs 86­96 FEbruary 2014 doi:10.1093/jpe/rtt016, Beijing 100049, China 3 Department of Plant and Soil Science, University of Vermont, Burlington VT 05405 of the Fungal phospholipid fatty acids (PlFas)/ bacterial PlFas ratio. Fungal PlFa values were greater

Neher, Deborah A.

117

Bcl2 Oncoprotein Blocks Chemotherapy-Induced Apoptosis in a Human Leukemia Cell Line  

Microsoft Academic Search

HE bcl-2 gene was initially discovered by virtue of its T involvement in t( 14; 181 (q32;q21) chromosomal translocations that are found in the majority of non-Hodg- kin's lymphomas (NHLs).' This gene encodes a 26-Kd in- tegral membrane protein that appears to reside at least in part in mitochondria, and that promotes the survival of sev- eral types of hematolymphoid

Toshiyuki Miyashita; John C. Reed

1993-01-01

118

Human Papillomavirus Type 16 E6/E7-Specific Cytotoxic T Lymphocytes for Adoptive Immunotherapy of HPV-Associated Malignancies  

PubMed Central

Vaccines prevent HPV-associated cancer but, although these tumors express foreign, viral antigens (E6 and E7 proteins), they have little benefit in established malignancies, likely due to negative environmental cues that block tumor recognition and induce T cell anergy in vivo. We postulated that we could identify mechanisms by which ex vivo stimulation of T cells could reactivate and expand tumor-directed T-cell lines from HPV-positive cancer patients for subsequent adoptive immunotherapy. A total of 68 patients with HPV-associated cancers were studied. Peripheral blood T cells were stimulated with monocyte-derived dendritic cells loaded with pepmixes (peptide libraries of 15-mers overlapping by 11 amino-acids) spanning E6/E7, in the presence or absence of specific accessory cytokines. The resulting T-cell lines were further expanded with pepmix-loaded activated B-cell blasts. IFN? release and cytotoxic responses to E6/E7 were assessed. We successfully reactivated and expanded (>1200-fold) E6/E7-specific T cells from 8/16 cervical and 33/52 oropharyngeal cancer patients. The presence of the cytokines IL-6, -7, -12 and -15 is critical for this process. These T cell lines possess the desirable characteristics of polyclonality, multiple T-cell subset representation (including the memory compartment) and a TH1 bias, and may eliminate E6/E7-positive targets. In conclusion, we have shown it is possible to robustly generate HPV16 E6/E7-directed T-cell lines from patients with HPV16-associated cancers. Because our technique is scalable and good-manufacturing-procedures compliant, these lines could be used for adoptive cellular immunotherapy of patients with HPV16-positive cancers. PMID:23211628

Ramos, Carlos A.; Narala, Neeharika; Vyas, Gayatri M.; Leen, Ann M.; Gerdemann, Ulrike; Sturgis, Erich M.; Anderson, Matthew L.; Savoldo, Barbara; Heslop, Helen E.; Brenner, Malcolm K.; Rooney, Cliona M.

2012-01-01

119

Control of Microtubule Dynamics by Oncoprotein 18: Dissection of the Regulatory Role of Multisite Phosphorylation during Mitosis  

Microsoft Academic Search

Oncoprotein 18 (Op18; also termed p19, 19K, metablastin, stathmin, and prosolin) is a conserved protein that regulates microtubule (MT) dynamics. Op18 is multisite phosphorylated on four Ser residues during mitosis; two of these Ser residues, Ser-25 and Ser-38, are targets for cyclin-dependent protein kinases (CDKs), and the other two Ser residues, Ser-16 and Ser-63, are targets for an unidentified protein

NIKLAS LARSSON; ULRICA MARKLUND; HELENA MELANDER GRADIN; GORAN BRATTSAND; MARTIN GULLBERG

1997-01-01

120

Activation of non-canonical NF-kappaB pathway mediated by STP-A11, an oncoprotein of Herpesvirus saimiri.  

PubMed

Although Saimiri Transforming Protein (STP)-A11, an oncoprotein of Herpesvirus saimiri, has been known to activate NF-kappaB signaling pathway, the detailed mechanism has not been reported yet. We herein report that STP-A11 activates non-canonical NF-kappaB pathway, resulting in p100 processing to p52. In addition, translocation of p52 protein (NF-kappaB2) into the nucleus is observed by the expression of STP-A11. STP-A11-mediated processing of p100 to p52 protein requires proteosome-mediated proteolysis because MG132 treatment clearly blocked p52 production in spite of the expression of STP-A11. Analysis of STP-A11 mutants to activate NF-kappaB2 pathway discloses the requirement of TRAF6-binding site not Src-binding site for STP-A11-mediated NF-kappaB2 pathway. Blockage of STP-A11-mediated p52 production using siRNA against p52 enhanced a chemotherapeutic drug-mediated cell death, suggesting that p52 production induced by the expression of STP-A11 would contribute to cellular transformation, which results from a resistance to cell death. PMID:17028057

Cho, Il-Rae; Jeong, Sunam; Jhun, Byung Hak; An, Won G; Lee, BokSoo; Kwak, Youn-Tae; Lee, Sun-Hwa; Jung, Jae U; Chung, Young-Hwa

2007-03-01

121

Identification of human T cell leukemia virus type 1 tax amino acid signals and cellular factors involved in secretion of the viral oncoprotein.  

PubMed

Human T cell leukemia virus type 1 (HTLV-1) is the etiologic agent of a number of pathologic abnormalities, including adult T cell leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The viral oncoprotein Tax has been implicated in the pathogenesis of these diseases. Recently, cell-free Tax was detected in the cerebrospinal fluid of HAM/TSP patients, implying that extracellular Tax may be relevant to neurologic disease. Additionally, the presence of a nuclear export signal within Tax and its active secretion has been demonstrated in vitro. However, the mechanism of Tax secretion remains to be established. Studies reported herein elucidate the process of Tax secretion and identify domains of Tax critical to its subcellular localization and secretion. Tax was shown to interact with a number of cellular secretory pathway proteins in both the model cell line BHK (baby hamster kidney)-21 and an HTLV-1-infected T cell line, C8166, physiologically relevant to HTLV-1-induced disease. Silencing of selected components of the secretory pathway affected Tax secretion, further confirming regulated secretion of Tax. Additionally, mutations in two putative secretory signals within Tax DHE and YTNI resulted in aberrant subcellular localization of Tax and significantly altered protein secretion. Together, these studies demonstrate that Tax secretion is a regulated event facilitated by its interactions with proteins of the cellular secretory pathway and the presence of secretory signals within the carboxyl-terminal domain of the protein. PMID:17897946

Jain, Pooja; Mostoller, Kate; Flaig, Katherine E; Ahuja, Jaya; Lepoutre, Veronique; Alefantis, Timothy; Khan, Zafar K; Wigdahl, Brian

2007-11-23

122

C-erbB-2 onco-protein expression in breast cancer: relationship to tumour characteristics and short-term survival in Universiti Kebansaan Malaysia Medical Centre.  

PubMed

Breast cancer is the commonest cancer affecting females in Malaysia, contributing 31% of all newly diagnosed cases amongst Malaysian women. The present retrospective cohort study evaluated the relationship between cerbB- 2 onco-protein overexpression with various tumour characteristics and survival rate of breast cancer patients treated at the Universiti Kebangsaan Malaysia Medical Centre (UKMMC) between 1996-2000. CerbB- 2 oncoprotein overexpression was determined by immunohistochemistry (IHC) and tumors showing 2+ positivity were verified by Fluorescence In Situ Hybridization (FISH). One hundred and seventy two patients were eligible for the study with a short-term follow-up (median) of 5.1 years. C-erbB-2 oncoprotein overexpression correlated with lymph node positivity, oestrogen receptor (ER) and progesterone receptor (PR) negativity. Univariate analyses showed shorter disease free survival (DFS) and overall survival (OS) in patients with cerbB- 2 oncoprotein overexpression, Malay ethnicity, higher tumour grade, lymph node positivity, ER and PR negativity. In a subgroup of patients with c-erbB-2 oncoprotein overexpression, a shorter OS was observed in those with lymph node positivity, ER and PR negativity. In multivariate prognostic analysis, lymph node status, ER status and tumour grading were the strongest independent prognostic factors for both OS and DFS. However, c-erbB-2 status was not a significantly independent prognostic factor, even in subsets with lymph node positive or negative group. C-erbB-2 oncoprotein overexpression correlated well with lymph node status, ER and PR. Shorter OS and DFS were significantly observed in patients with c-erbB-2 oncoprotein overexpression. Lymph node status, ER status and tumour grading were the only three independent prognostic factors for OS and DFS in this study. Although c-erbB-2 expression is obviously important from a biological standpoint, multivariate analysis showed that it is not an independent prognostic indicator in breast carcinoma in the local population. PMID:19271345

Sharifah, N A; Lee, B R; Clarence-Ko, C H; Tan, G C; Shiran, M S; Naqiyah, I; Rohaizak, M; Fuad, I; Tamil, A M

2008-01-01

123

Identification of Functionally Distinct TRAF Proinflammatory and Phosphatidylinositol 3-Kinase/Mitogen-activated Protein Kinase/Extracellular Signal-regulated Kinase Kinase (PI3K/MEK) Transforming Activities Emanating from RET/PTC Fusion Oncoprotein*  

PubMed Central

Thyroid carcinomas that harbor RET/PTC oncogenes are well differentiated, relatively benign neoplasms compared with those expressing oncogenic RAS or BRAF mutations despite signaling through shared transforming pathways. A distinction, however, is that RET/PTCs induce immunostimulatory programs, suggesting that, in the case of this tumor type, the additional pro-inflammatory pathway reduces aggressiveness. Here, we demonstrate that pro-inflammatory programs are selectively activated by TRAF2 and TRAF6 association with RET/PTC oncoproteins. Eliminating this mechanism reduces pro-inflammatory cytokine production without decreasing transformation efficiency. Conversely, ablating MEK/ERK or PI3K/AKT signaling eliminates transformation but not pro-inflammatory cytokine secretion. Functional uncoupling of the two pathways demonstrates that intrinsic pro-inflammatory pathways are not required for cellular transformation and suggests a need for further investigation into the role inflammation plays in thyroid tumor progression. PMID:22158616

Wixted, Josephine H. F.; Rothstein, Jay L.; Eisenlohr, Laurence C.

2012-01-01

124

42 CFR 52e.7 - What are the terms and conditions of awards?  

Code of Federal Regulations, 2011 CFR

...7 Section 52e.7 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS NATIONAL HEART, LUNG, AND BLOOD INSTITUTE GRANTS FOR PREVENTION AND CONTROL PROJECTS § 52e.7 What are the terms and conditions of...

2011-10-01

125

42 CFR 52e.7 - What are the terms and conditions of awards?  

Code of Federal Regulations, 2013 CFR

...Section 52e.7 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS NATIONAL HEART, LUNG, AND BLOOD INSTITUTE GRANTS FOR PREVENTION AND CONTROL PROJECTS § 52e.7 What are the terms and conditions of...

2013-10-01

126

42 CFR 52e.7 - What are the terms and conditions of awards?  

Code of Federal Regulations, 2014 CFR

...Section 52e.7 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS NATIONAL HEART, LUNG, AND BLOOD INSTITUTE GRANTS FOR PREVENTION AND CONTROL PROJECTS § 52e.7 What are the terms and conditions of...

2014-10-01

127

42 CFR 52e.7 - What are the terms and conditions of awards?  

Code of Federal Regulations, 2012 CFR

...Section 52e.7 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS NATIONAL HEART, LUNG, AND BLOOD INSTITUTE GRANTS FOR PREVENTION AND CONTROL PROJECTS § 52e.7 What are the terms and conditions of...

2012-10-01

128

A novel fusion protein-based vaccine comprising a cell penetrating and immunostimulatory peptide linked to human papillomavirus (HPV) type 16 E7 antigen generates potent immunologic and anti-tumor responses in mice.  

PubMed

The ultimate success of cancer vaccination is dependent upon the generation of tumor-specific CTLs. In this study, we designed and evaluated a novel fusion protein comprising a cell penetrating and immunostimulatory peptide corresponding to residues 32-51 of the Limulus polyphemus protein (LALF(32-51)) linked to human papillomavirus (HPV) 16 E7 antigen (LALF(32-51)-E7). We demonstrated that LALF(32-51) penetrates the cell membrane and delivers E7 into cells. In a preclinical model of HPV16-induced cervical carcinoma we showed that vaccination with adjuvant-free LALF(32-51)-E7 fusion protein significantly improves the presentation of E7-derived peptides to T-cells in vitro and induces suppression of tumor growth. PMID:21145912

Granadillo, Milaid; Vallespi, Maribel G; Batte, Aileen; Mendoza, Osmany; Soria, Yordanka; Lugo, Victoria M; Torrens, Isis

2011-01-29

129

Oncoprotein EWS-FLI1 activity is enhanced by RNA helicase A.  

PubMed

RNA helicase A (RHA), a member of the DEXH box helicase family of proteins, is an integral component of protein complexes that regulate transcription and splicing. The EWS-FLI1 oncoprotein is expressed as a result of the chromosomal translocation t(11;22) that occurs in patients with the Ewing's sarcoma family of tumors (ESFT). Using phage display library screening, we identified an EWS-FLI1 binding peptide containing homology to RHA. ESFT cell lines and patient tumors highly expressed RHA. GST pull-down and ELISA assays showed that EWS-FLI1 specifically bound RHA fragment amino acids 630 to 1020, which contains the peptide region discovered by phage display. Endogenous RHA was identified in a protein complex with EWS-FLI1 in ESFT cell lines. Chromatin immunoprecipitation experiments showed both EWS-FLI1 and RHA bound to EWS-FLI1 target gene promoters. RHA stimulated the transcriptional activity of EWS-FLI1 regulated promoters, including Id2, in ESFT cells. In addition, RHA expression in mouse embryonic fibroblast cells stably transfected with EWS-FLI1 enhanced the anchorage-independent phenotype above that with EWS-FLI1 alone. These results suggest that RHA interacts with EWS-FLI1 as a transcriptional cofactor to enhance its function. PMID:16740692

Toretsky, Jeffrey A; Erkizan, Verda; Levenson, Amy; Abaan, Ogan D; Parvin, Jeffrey D; Cripe, Timothy P; Rice, Anna M; Lee, Sean Bong; Uren, Aykut

2006-06-01

130

Structural Role of the Conserved Cysteines in the Dimerization of the Viral Transmembrane Oncoprotein E5  

PubMed Central

The E5 oncoprotein is the major transforming protein of bovine papillomavirus type 1. This 44-residue transmembrane protein can interact with the platelet-derived growth factor receptor ?, leading to ligand-independent activation and cell transformation. For productive interaction, E5 needs to dimerize via a C-terminal pair of cysteines, though a recent study suggested that its truncated transmembrane segment can dimerize on its own. To analyze the structure of the full protein in a membrane environment and elucidate the role of the Cys-Ser-Cys motif, we produced recombinantly the wild-type protein and four cysteine mutants. Comparison by circular dichroism in detergent micelles and lipid vesicular dispersion and by NMR in trifluoroethanol demonstrates that the absence of one or both cysteines does not influence the highly ?-helical secondary structure, nor does it impair the ability of E5 to dimerize, observations that are further supported by sodium dodecylsulfate polyacrylamide gel electrophoresis. We also observed assemblies of higher order. Oriented circular dichroism in lipid bilayers shows that E5 is aligned as a transmembrane helix with a slight tilt angle, and that this membrane alignment is also independent of any cysteines. We conclude that the Cys-containing motif represents a disordered region of the protein that serves as an extra covalent connection for stabilization. PMID:20858420

Windisch, Dirk; Hoffmann, Silke; Afonin, Sergii; Vollmer, Stefanie; Benamira, Soraya; Langer, Birgid; Bürck, Jochen; Muhle-Goll, Claudia; Ulrich, Anne S.

2010-01-01

131

Structural characterization of a C-terminally truncated E5 oncoprotein from papillomavirus in lipid bilayers.  

PubMed

E5 is the major transforming oncoprotein of bovine papillomavirus, which activates the platelet-derived growth factor receptor ? in a highly specific manner. The short transmembrane protein E5 with only 44 residues interacts directly with the transmembrane segments of the receptor, but structural details are not available. Biophysical investigations are challenging, because the hydrophobic E5 protein tends to aggregate and get cross-linked non-specifically via two Cys residues near its C-terminus. Here, we demonstrate that a truncation by 10 amino acids creates a more manageable protein that can be conveniently used for structure analysis. Synchrotron radiation circular dichroism and solid-state (15)N- and (31)P-nuclear magnetic resonance spectroscopy show that this E5 variant serves as a representative model for the wild-type protein. The helical conformation of the transmembrane segment, its orientation in the lipid bilayer, and the ability to form homodimers in the membrane are not affected by the C-terminal truncation. PMID:25324446

Windisch, Dirk; Ziegler, Colin; Bürck, Jochen; Ulrich, Anne S

2014-12-01

132

DNA binding and transcriptional activation by the Ski oncoprotein mediated by interaction with NFI.  

PubMed Central

The Ski oncoprotein has been found to bind non-specifically to DNA in association with unindentified nuclear factors. In addition, Ski has been shown to activate transcription of muscle-specific and viral promoters/enhancers. The present study was undertaken to identify Ski's DNA binding and transcriptional activation partners by identifying specific DNA binding sites. We used nuclear extracts from a v-Ski-transduced mouse L-cell line and selected Ski-bound sequences from a pool of degenerate oligonucleotides with anti-Ski monoclonal antibodies. Two sequences were identified by this technique. The first (TGGC/ANNNNNT/GCCAA) is the previously identified binding site of the nuclear factor I (NFI) family of transcription factors. The second (TCCCNNGGGA) is the binding site of Olf-1/EBF. By electophoretic mobility shift assays we find that Ski is a component of one or more NFI complexes but we fail to detect Ski in Olf-1/EBF complexes. We show that Ski binds NFI proteins and activates transcription of NFI reporters, but only in the presence of NFI. We also find that homodimerization of Ski is essential for co-activation with NFI. However, the C-terminal dimerization domain of c-Ski, which is missing in v-Ski, can be substituted by the leucine zipper domain of GCN4. PMID:9380514

Tarapore, P; Richmond, C; Zheng, G; Cohen, S B; Kelder, B; Kopchick, J; Kruse, U; Sippel, A E; Colmenares, C; Stavnezer, E

1997-01-01

133

RGG-boxes of the EWS oncoprotein repress a range of transcriptional activation domains.  

PubMed

The Ewings Sarcoma Oncoprotein (EWS) interacts with several components of the mammalian transcriptional and pre-mRNA splicing machinery and is also found in the cytoplasm and even on the cell surface. The apparently diverse cellular functions of EWS are, however, not well characterized. EWS harbours a potent N-terminal transcriptional activation domain (the EAD) that is revealed in the context of oncogenic EWS-fusion proteins (EFPs) and a C-terminal RNA-binding domain (RBD) that recruits pre-mRNA splicing factors and may couple transcription and splicing. In contrast to EFPs, the presumed transcriptional role of normal EWS remains enigmatic. Here, we report that multiple RGG-boxes within the RBD are necessary and sufficient for cis-repression of the EAD and that RGG-boxes can also repress in-trans, within dimeric partners. Lys can functionally substitute for Arg, indicating that the basic nature of the Arg side chain is the critical determinant of RGG-box-mediated repression. In addition to the EAD, RGG-boxes can repress a broad range of activation domains (including those of VP16, E1a and CREB), but repression can be alleviated by the simultaneous presence of more than one activation domain. We therefore propose that a key function of RGG boxes within native EWS is to restrict promiscuous activation by the EAD while still allowing EWS to enter functional transcription complexes and participate in other transactions involving pre-mRNAs. PMID:15743974

Alex, Deepa; Lee, Kevin A W

2005-01-01

134

Human papillomavirus 16 E7 inactivator of retinoblastoma family proteins complements  

E-print Network

Human papillomavirus 16 E7 inactivator of retinoblastoma family proteins complements human tested whether the human papillomavirus type 16 E7 protein, which inactivates pRb family proteins papillomavirus (HPV), of which certain subtypes cause cervical cancer (2). The HPV16 E7 protein binds

135

Inactivation of the human papillomavirus E6 or E7 gene in cervical carcinoma cells by using a bacterial CRISPR/Cas RNA-guided endonuclease.  

PubMed

High-risk human papillomaviruses (HPVs), including HPV-16 and HPV-18, are the causative agents of cervical carcinomas and are linked to several other tumors of the anogenital and oropharyngeal regions. The majority of HPV-induced tumors contain integrated copies of the normally episomal HPV genome that invariably retain intact forms of the two HPV oncogenes E6 and E7. E6 induces degradation of the cellular tumor suppressor p53, while E7 destabilizes the retinoblastoma (Rb) protein. Previous work has shown that loss of E6 function in cervical cancer cells induces p53 expression as well as downstream effectors that induce apoptosis and cell cycle arrest. Similarly, loss of E7 allows increased Rb expression, leading to cell cycle arrest and senescence. Here, we demonstrate that expression of a bacterial Cas9 RNA-guided endonuclease, together with single guide RNAs (sgRNAs) specific for E6 or E7, is able to induce cleavage of the HPV genome, resulting in the introduction of inactivating deletion and insertion mutations into the E6 or E7 gene. This results in the induction of p53 or Rb, leading to cell cycle arrest and eventual cell death. Both HPV-16- and HPV-18-transformed cells were found to be responsive to targeted HPV genome-specific DNA cleavage. These data provide a proof of principle for the idea that vector-delivered Cas9/sgRNA combinations could represent effective treatment modalities for HPV-induced cancers. Importance: Human papillomaviruses (HPVs) are the causative agents of almost all cervical carcinomas and many other tumors, including many head and neck cancers. In these cancer cells, the HPV DNA genome is integrated into the cellular genome, where it expresses high levels of two viral oncogenes, called E6 and E7, that are required for cancer cell growth and viability. Here, we demonstrate that the recently described bacterial CRISPR/Cas RNA-guided endonuclease can be reprogrammed to target and destroy the E6 or E7 gene in cervical carcinoma cells transformed by HPV, resulting in cell cycle arrest, leading to cancer cell death. We propose that viral vectors designed to deliver E6- and/or E7-specific CRISPR/Cas to tumor cells could represent a novel and highly effective tool to treat and eliminate HPV-induced cancers. PMID:25100830

Kennedy, Edward M; Kornepati, Anand V R; Goldstein, Michael; Bogerd, Hal P; Poling, Brigid C; Whisnant, Adam W; Kastan, Michael B; Cullen, Bryan R

2014-10-01

136

The oncoprotein hepatitis B X-interacting protein promotes the migration of ovarian cancer cells through the upregulation of S-phase kinase-associated protein 2 by Sp1.  

PubMed

Hepatitis B X-interacting protein (HBXIP) is a novel oncoprotein. We have previously reported that HBXIP promotes the proliferation and migration of breast cancer cells. S-phase kinase-associated protein 2 (Skp2) is another oncoprotein which is important for migration. In this study, we investigated whether Skp2 is involved in the migration enhanced by HBXIP in ovarian cancer. The expression of HBXIP and Skp2 in ovarian cancer tissues was examined by immunohistochemistry using tissue microarrays. The role of HBXIP and Skp2 in the migration of ovarian cancer cells was investigated by wound-healing assay and Transwell migration assay. The effect of HBXIP on Skp2 was assessed by reverse transcription polymerase chain reaction (RT-PCR), western blot analysis, luciferase reporter gene assays and chromatin immunoprecipitation in ovarian cancer cells (SKOV3 and CAOV3). We found that both HBXIP and Skp2 were highly expressed in ovarian cancer tissues. We observed that the overexpression of HBXIP enhanced the migration of ovarian cancer cells, while Skp2 siRNAs decreased the cell migration enhanced by HBXIP. The HBXIP siRNAs inhibited ovarian cancer cell migration and Skp2 rescued the migration inhibition induced by HBXIP siRNA. HBXIP could upregulate Skp2 at the levels of mRNA and protein in ovarian cancer cells. Moreover, HBXIP increased the activity of Skp2 promoter via binding to the transcription factor Sp1. HBXIP is highly expressed in ovarian cancer tissues. HBXIP enhances the migration of ovarian cancer cells. HBXIP was able to stimulate the activity of Skp2 promoter via transcription factor Sp1 thus promoting the migration of ovarian cancer cells. PMID:24788380

Xu, Fuqiang; Zhu, Xiaoming; Han, Tao; You, Xiaona; Liu, Fabao; Ye, Lihong; Zhang, Xiaodong; Wang, Xiaohong; Yao, Yuanqing

2014-07-01

137

High expression of oncoprotein DEK predicts poor prognosis of small cell lung cancer  

PubMed Central

Oncoprotein DEK plays an important role in cancer tumorigenesis. To explore the clinical implication of DEK expression on prognostic evaluation in small cell lung cancer (SCLC), 130 cases of SCLC with strict follow-up were selected for immunohistochemical (IHC) staining of DEK protein. The correlation between DEK expression and clinicopathological features of SCLC was evaluated using the Chi-square and Fisher’s exact tests, survival rates were calculated using the Kaplan-Meier method and univariate and multivariate analyses were performed using the Cox proportional hazards regression model. IHC analysis demonstrated that DEK protein staining was strongly positive and significantly higher (44.62%) in SCLC compared with either adjacent non-tumor or normal lung tissues (P < 0.001 for both). DEK expression correlated with large tumor size (P = 0.025) and late pathologic stage (P = 0.005). Moreover, it correlated with low disease-free (P = 0.004) and 5-year (P = 0.005) survival rates. In the late-stage group, disease-free and 5-year survival rates of patients with high level DEK expression were significantly lower than those with low level DEK expression (P = 0.006 and P = 0.001, respectively). Furthermore, Cox analysis revealed that DEK expression emerged as a significant independent hazard factor for the overall survival rate of patients with SCLC (HR: 1.594, 95% CI: 1.087-2.336, P = 0.017). In conclusion, DEK plays an important role in the progression of SCLC. DEK may potentially be used as an independent biomarker for the prognostic evaluation of SCLC. PMID:25197373

Wang, Xiaoyan; Lin, Lijuan; Ren, Xiangshan; Lin, Zhenhua; Li, Zhuhu; Li, Chunyu; Jin, Tiefeng

2014-01-01

138

HPV16 E7Dependent Transformation Activates NHE1 through a PKA-RhoA-Iinduced Inhibition of p38alpha  

Microsoft Academic Search

BackgroundNeoplastic transformation originates from a large number of different genetic alterations. Despite this genetic variability, a common phenotype to transformed cells is cellular alkalinization. We have previously shown in human keratinocytes and a cell line in which transformation can be turned on and followed by the inducible expression of the E7 oncogene of human papillomavirus type 16 (HPV16), that intracellular

Rosa A. Cardone; Giovanni Busco; Maria R. Greco; Antonia Bellizzi; Rosita Accardi; Antonella Cafarelli; Stefania Monterisi; Pierluigi Carratù; Valeria Casavola; Angelo Paradiso; Massimo Tommasino; Stephan J. Reshkin; Dong-Yan Jin

2008-01-01

139

Low- and high-risk human papillomavirus E7 proteins regulate p130 differently  

SciTech Connect

The E7 protein of high-risk human papillomaviruses (HR HPVs) targets pRb family members (pRb, p107 and p130) for degradation; low-risk (LR) HPV E7 only targets p130 for degradation. The effect of HR HPV 16 E7 and LR HPV 6 E7 on p130 intracellular localization and half-life was examined. Nuclear/cytoplasmic fractionation and immunofluorescence showed that, in contrast to control and HPV 6 E7-expressing cells, a greater amount of p130 was present in the cytoplasm in the presence of HPV 16 E7. The half-life of p130, relative to control cells, was decreased in the cytoplasm in the presence of HPV 6 E7 or HPV 16 E7, but only decreased by HPV 6 E7 in the nucleus. Inhibition of proteasomal degradation extended the half-life of p130, regardless of intracellular localization. These results suggest that there may be divergent mechanisms by which LR and HR HPV E7 target p130 for degradation.

Barrow-Laing, Lisa; Chen Wei [Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202 (United States); Roman, Ann, E-mail: aroman@iupui.ed [Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202 (United States)

2010-05-10

140

Up-Regulation of FOXM1 by E6 Oncoprotein through the MZF1/NKX2-1 Axis Is Required for Human Papillomavirus–Associated Tumorigenesis12  

PubMed Central

PURPOSE: Foxhead box M1 (FOXM1) expression has been shown to be linked with human papillomavirus (HPV) 16/18–infected cervical cancer. However, the mechanism underlying the induction of FOXM1 in HPV 16/18–infected cancers remains elusive. EXPERIMENTAL DESIGN: The mechanistic actions of FOXM1 induced by the E6/NKX2-1 axis in tumor aggressiveness were elucidated in cellular and animal models. The prognostic value of FOXM1 for overall survival (OS) and relapse-free survival (RFS) in HPV-positive oral and lung cancers was assessed using Kaplan-Meier and Cox regression models. RESULTS: Herein, FOXM1 expression is upregulated by E6-mediated NKX2-1 in HPV-positive cervical, oral, and lung cancer cells. Induction of FOXM1 by E6 through the MZF1/NKX2-1 axis is responsible for HPV-mediated soft agar growth, invasiveness, and stemness through activating Wnt/?-catenin signaling pathway. In a nude mice model, metastatic lung tumor nodules in HPV 18 E6-positive GNM or HPV 16 E6-positive TL-1–injected nude mice were markedly decreased in both cell types with E6 knockdown, FOXM1 knockdown, or treatment with FOXM1 inhibitor (thiostrepton). Among the four subgroup patients, the worst FOXM1 prognostic value for OS and RFS was observed in HPV 16/18–positive patients with tumors with high-expressing FOXM1. CONCLUSIONS: Induction of FOXM1 by E6 oncoprotein through the MZF1/NKX2-1 axis may be responsible for HPV 16/18–mediated tumor progression and poor outcomes in HPV-positive patients. PMID:25425970

Chen, Po-Ming; Cheng, Ya-Wen; Wang, Yao-Chen; Wu, Tzu-Chin; Chen, Chih-Yi; Lee, Huei

2014-01-01

141

Targeting SET/I2PP2A Oncoprotein Functions as a Multi-pathway Strategy for Cancer Therapy  

PubMed Central

The SET oncoprotein participates in cancer progression by affecting multiple cellular processes, inhibiting the tumor suppressor PP2A and inhibiting the metastasis suppressor nm23-H1. Based upon these multiple activities, we hypothesized that targeted inhibition of SET would have multiple discrete and measurable effects on cancer cells. Here, the effects of inhibiting SET oncoprotein function on intracellular signaling and proliferation of human cancer cell lines was investigated. We observed the effects of COG112, a novel SET interacting peptide, on PP2A activity, Akt signaling, nm23-H1 activity, and cellular migration/invasion in human U87 glioblastoma and MDA-MB-231 breast adenocarcinoma cancer cell lines. We found that COG112 interacted with SET protein and inhibited the association between SET and PP2A-c or nm23-H1. The interaction between COG112 and SET caused PP2A phosphatase, and nm23-H1 exonuclease activities, to increase. COG112-mediated increases in PP2A activity resulted in the inhibition of Akt signaling and cellular proliferation. Additionally, COG112 inhibited SET association with Rac1 leading to decreased cellular migration and invasion. COG112 treatment releases the SET-mediated inhibition of the tumor suppressor PP2A, as well as the metastasis suppressor nm23-H1. These results establish SET as a novel molecular target, and that the inhibition of SET may have beneficial effects in cancer chemotherapy. PMID:21297667

Switzer, Christopher H.; Cheng, Robert Y.S.; Vitek, Timothy M.; Christensen, Dale J.; Wink, David A.; Vitek, Michael P.

2010-01-01

142

HPV16 synthetic long peptide (HPV16-SLP) vaccination therapy of patients with advanced or recurrent HPV16-induced gynecological carcinoma, a phase II trial  

PubMed Central

Background Human papilloma virus type 16 (HPV16)-induced gynecological cancers, in particular cervical cancers, are found in many women worldwide. The HPV16 encoded oncoproteins E6 and E7 are tumor-specific targets for the adaptive immune system permitting the development of an HPV16-synthetic long peptide (SLP) vaccine with an excellent treatment profile in animal models. Here, we determined the toxicity, safety, immunogenicity and efficacy of the HPV16 SLP vaccine in patients with advanced or recurrent HPV16-induced gynecological carcinoma. Methods Patients with HPV16-positive advanced or recurrent gynecological carcinoma (n?=?20) were subcutaneously vaccinated with an HPV16-SLP vaccine consisting of a mix of 13 HPV16 E6 and HPV16 E7 overlapping long peptides in Montanide ISA-51 adjuvant. The primary endpoints were safety, toxicity and tumor regression as determined by RECIST. In addition, the vaccine-induced T-cell response was assessed by proliferation and associated cytokine production as well as IFN?-ELISPOT. Results No systemic toxicity beyond CTCAE grade II was observed. In a few patients transient flu-like symptoms were observed. In 9 out of 16 tested patients vaccine-induced HPV16-specific proliferative responses were detected which were associated with the production of IFN?, TNF?, IL-5 and/or IL-10. ELISPOT analysis revealed a vaccine-induced immune response in 11 of the 13 tested patients. The capacity to respond to the vaccine was positively correlated to the patient’s immune status as reflected by their response to common recall antigens at the start of the trial. Median survival was 12.6 ± 9.1?months. No regression of tumors was observed among the 12 evaluable patients. Nineteen patients died of progressive disease. Conclusions The HPV16-SLP vaccine was well tolerated and induced a broad IFN?-associated T-cell response in patients with advanced or recurrent HPV16-induced gynecological carcinoma but neither induced tumor regression nor prevented progressive disease. We, therefore, plan to use this vaccine in combination with chemotherapy and immunomodulation. PMID:23557172

2013-01-01

143

The causes of cancer revisited: “Mitochondrial malignancy” and ROS-induced oncogenic transformation – Why mitochondria are targets for cancer therapy  

Microsoft Academic Search

The role of oncoproteins and tumor suppressor proteins in promoting the malignant transformation of mammalian cells by affecting properties such as proliferative signalling, cell cycle regulation and altered adhesion is well established. Chemicals, viruses and radiation are also generally accepted as agents that commonly induce mutations in the genes encoding these cancer-causing proteins, thereby giving rise to cancer. However, more

Stephen J. Ralph; Sara Rodríguez-Enríquez; Jiri Neuzil; Emma Saavedra; Rafael Moreno-Sánchez

2010-01-01

144

Heterodimerization of Hox proteins with Pbx1 and oncoprotein E2a-Pbx1 generates unique DNA-binding specifities at nucleotides predicted to contact the N-terminal arm of the Hox homeodomain--demonstration of Hox-dependent targeting of E2a-Pbx1 in vivo.  

PubMed

Hox proteins control genetic programs that orchestrate development, and a large subset of Hox proteins can bind DNA elements as heterodimers with the Pbx family of homeodomain proteins. A transcriptionally activated version of Pbx1, E2a-Pbx1, is an oncoprotein in human pre-B cell leukemia that strongly suppresses differentiation and retains its ability to heterodimerize with Hox proteins. Because monomeric Hox proteins bind very similar DNA motifs, it is unclear how they activate diverse developmental programs. Here we demonstrate that heterodimers containing different Hox proteins and a common Pbx1 or E2a-Pbx1 partner bind different DNA motifs. Structural models suggest that the specificity of the Hox protein is altered by a conformation change involving residues in the N-terminal arm of the Hox homeodomain. Mutational analysis also supported the hypothesis that unique sequences in the N-terminal arm of the Hox homeodomain are at least partially responsible for mediating this specificity. In vivo, Hox proteins directed E2a-Pbx1-mediated transactivation with moderate specificity to cognate Hox-Pbx motifs. Thus, the development specificity of individual Hox proteins may be mediated, in part, by differential targeting of cellular genes by Pbx1-Hox complexes. Likewise, through its function as a common heterodimer partner, oncoprotein E2a-Pbx1 may be able to interfere with multiple programs of development that are induced by the sequential or simultaneous expression of Hox proteins during hematopoiesis. PMID:9010234

Lu, Q; Kamps, M P

1997-01-01

145

Repression of MHC class I transcription by HPV16E7 through interaction with a putative RXR{beta} motif and NF-{kappa}B cytoplasmic sequestration  

SciTech Connect

Down-regulation of transcription of the MHC class I genes in HPV16 tumorigenic cells is partly due to HPV16E7 associated with the MHC class I promoter and repressed chromatin activation. In this study, we further demonstrated that HPV16E7 is physically associated with a putative RXR{beta} binding motif (GGTCA) of the proximal promoter of the MHC class I genes by using reporter transcriptional assays and chromatin immunoprecipitation assays. Our data also provide evidence that HPV16E7 inhibits TNF-{alpha}-induced up-regulation of MHC class I transcription by impaired nuclear translocation of NF-{kappa}B. More importantly, CaSki tumor cells treated with TSA and transfected with the constitutively active mutant form of IKK-{alpha} (which can activate NF-{kappa}B directly) showed a maximal level of up-regulation of MHC-I expression. Taken together, our results suggest that HPV16E7 may employ two independent mechanisms to ensure that either the constitutive or inducible transcription of MHC class I genes is down-regulated.

Li, Hui; Zhan, TaiLan; Li, Chang [Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology and Center for Human Genome Research, Huazhong University of Science and Technology, Wuhan (China)] [Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology and Center for Human Genome Research, Huazhong University of Science and Technology, Wuhan (China); Liu, Mugen, E-mail: lium@mail.hust.edu.cn [Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology and Center for Human Genome Research, Huazhong University of Science and Technology, Wuhan (China)] [Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology and Center for Human Genome Research, Huazhong University of Science and Technology, Wuhan (China); Wang, Qing K., E-mail: qkwang@mail.hust.edu.cn [Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology and Center for Human Genome Research, Huazhong University of Science and Technology, Wuhan (China); Center for Cardiovascular Genetics, Cleveland Clinic, Cleveland, OH 44195 (United States)

2009-10-16

146

Oncogenic and nononcogenic human genital papillomaviruses generate the E7 mRNA by different mechanisms.  

PubMed Central

A new promoter located within E6 was mapped in human papillomavirus type 6b (HPV6b)- and HPV11-containing benign genital condylomata (genital warts). The RNA transcribed from this promoter represented the major RNA species colinear with open reading frames E6 and E7 and can encode the E7 protein. No equivalent promoter was active in HPV16-containing cancers and cancer-derived cell lines. In those, the major transcripts contained one of two different introns within E6 and the RNAs could encode two different E6 proteins and E7. Images PMID:2536845

Smotkin, D; Prokoph, H; Wettstein, F O

1989-01-01

147

Human Papillomavirus Type 16 E6* Induces Oxidative Stress and DNA Damage  

PubMed Central

ABSTRACT High-risk types of human papillomavirus (HPV) are the causative agents of virtually all cases of cervical cancer and a significant proportion of other anogenital cancers, as well as both oral and pharyngeal cancers. The high-risk types encode two viral oncogenes, E6 and E7, which work together to initiate cell transformation. Multiple steps involving the activities and interactions of both viral and cellular proteins are involved in the progression from HPV infection to cell transformation to cancer. The E6 oncoprotein is expressed as several isoforms: a full-length variant referred to as E6 and a few shorter isoforms collectively referred to as E6*. In this study, we found that expression of E6* increased the level of reactive oxygen species (ROS) in both HPV-positive and HPV-negative cells. This increased oxidative stress led to higher levels of DNA damage, as assessed by the comet assay, quantification of 8-oxoguanine, and poly(ADP-ribose) polymerase 1. The observed increase in ROS may be due to a decrease in cellular antioxidant activity, as we found that E6* expression also led to decreased expression of superoxide dismutase isoform 2 and glutathione peroxidase. These studies indicate that E6* may play an important role in virus-induced mutagenesis by increasing oxidative stress and DNA damage. IMPORTANCE Our findings demonstrate for the first time that an HPV gene product, E6*, can increase ROS levels in host cells. This ability may play a significant role both in the viral life cycle and in cancer development, because an increase in oxidative DNA damage may both facilitate HPV genome amplification and increase the probability of HPV16 DNA integration. Integration, in turn, is thought to be an important step in HPV-mediated carcinogenesis. PMID:24696478

Williams, Vonetta M.; Filippova, Maria; Filippov, Valery; Payne, Kimberly J.

2014-01-01

148

London School of Hygiene & Tropical Medicine Keppel Street, London WC1E 7HT, UK  

E-print Network

London School of Hygiene & Tropical Medicine Keppel Street, London WC1E 7HT, UK Switchboard: +44 (0 A global community The London School of Hygiene & Tropical Medicine is a world-leading centre for research

Maizels, Rick

149

Tax oncoprotein of HTLV1 binds to the human homologue of Drosophila discs large tumor suppressor protein, hDLG, and perturbs its function in cell growth control  

Microsoft Academic Search

HTLV-1 Tax oncoprotein interacts with various cellular factors and modulates transcription and the cell cycle. To identify more cellular targets, we employed the yeast two hybrid system with Tax using a human cDNA library, and isolated a cDNA encoding the human counterpart of Drosophila discs large tumor suppressor protein, hDLG. Tax binding to hDLG was confirmed in vitro and also

Takeshi Suzuki; Yohta Ohsugi; Masami Uchida-Toita; Tetsu Akiyama; Mitsuaki Yoshida

1999-01-01

150

PDZ domain-binding motif of human T-cell leukemia virus type 1 Tax oncoprotein augments the transforming activity in a rat fibroblast cell line  

Microsoft Academic Search

While human T-cell leukemia virus type 1 (HTLV-1) is associated with the development of adult T-cell leukemia (ATL), HTLV-2 has not been reported to be associated with such malignant leukemias. HTLV-1 Tax1 oncoprotein transforms a rat fibroblast cell line (Rat-1) to form multiple large colonies in soft agar, and this activity is much greater than that of HTLV-2 Tax2. We

Akira Hirata; Masaya Higuchi; Akiko Niinuma; Minako Ohashi; Masaya Fukushi; Masayasu Oie; Tetsu Akiyama; Yuetsu Tanaka; Fumitake Gejyo; Masahiro Fujii

2004-01-01

151

Human Papillomavirus Type 16 Nucleoprotein E7 is a Tumor Rejection Antigen  

Microsoft Academic Search

It has been speculated that immunological mechanisms play an important role in the control of carcinomas associated with human papillomavirus (HPV), such as cervical cancers. We have now demonstrated that immunization of C3H\\/HeN mice by syngeneic nontumorigenic fibroblast-like cells that contain the transfected HPV-16 E7 gene conferred protection against transplanted cells from a HPV-16 E7-positive syngeneic tumor. This protection was

Lieping Chen; Elaine Kinney Thomas; Shiu-Lok Hu; Ingegerd Hellstrom; Karl Erik Hellstrom

1991-01-01

152

Arsenic Trioxide Is a Potent Inhibitor of the Interaction of SMRT Corepressor with Its Transcription Factor Partners, Including the PML-Retinoic Acid Receptor ? Oncoprotein Found in Human Acute Promyelocytic Leukemia  

PubMed Central

The SMRT corepressor complex participates in transcriptional repression by a diverse array of vertebrate transcription factors. The ability to recruit SMRT appears to play a crucial role in leukemogenesis by the PML-retinoic acid receptor ? (RAR?) oncoprotein, an aberrant nuclear hormone receptor implicated in human acute promyelocytic leukemia (APL). Arsenite induces clinical remission of APL through a incompletely understood mechanism. We report here that arsenite is a potent inhibitor of the interaction of SMRT with its transcription factor partners, including PML-RAR?. Arsenite operates, in part, through a mitogen-activated protein (MAP) kinase cascade culminating in phosphorylation of the SMRT protein, dissociation of SMRT from its nuclear receptor partners, and a relocalization of SMRT out of the nucleus into the cytoplasm of the cell. Conversely, inhibition of this MAP kinase cascade attenuates the effects of arsenite on APL cells. Our results implicate SMRT as an important biological target for the actions of arsenite in both normal and neoplastic cells. PMID:11585900

Hong, Suk-Hyun; Yang, Zhihong; Privalsky, Martin L.

2001-01-01

153

HTLV1 oncoprotein Tax deregulates transcription of cellular genes through multiple mechanisms  

Microsoft Academic Search

Infection of a human retrovirus HTLV-1 induces adult T cell leukemia and a neurological disease, HAM\\/TSP. Regulatory protein Tax of HTLV-1 is thought to contribute to the pathogenesis. We have studied the mechanism of transcriptional activation induced by Tax protein and identified two independent mechanisms: (a) binding to the enhancer-binding proteins, CREB, CREM, NF-?B and SRF, resulting in the activation

Mitsuaki Yoshida

1995-01-01

154

Kaposi's sarcoma-associated herpesvirus (KSHV) oncoprotein K13 bypasses TRAFs and directly interacts with the IkappaB kinase complex to selectively activate NF-kappaB without JNK activation.  

PubMed

Kaposi's sarcoma herpesvirus oncoprotein vFLIP K13 is a potent activator of NF-kappaB and plays a key role in viral pathogenesis. K13 contains a putative TRAF-interacting motif, which is reportedly required for its interaction with TRAF2. The K13-TRAF2 interaction is believed to be essential for the recruitment of K13 to the I-kappaB kinase (IKK) complex and for K13-induced NF-kappaB and JNK activation. In addition, TRAF3 has been reported to be required for K13-induced NF-kappaB and JNK activation. We have re-examined the role of the TRAFs in K13 signaling and report that mutations in the putative TRAF-interacting motif of K13 have no deleterious effect on its ability to interact with the IKK complex or activation of the NF-kappaB pathway. Furthermore, endogenously expressed TRAF2 and TRAF3 do not interact with K13 and play no role in K13-induced NF-kappaB activation or its interaction with the IKK complex. Finally, K13 does not activate the JNK pathway. Our results support a model in which K13 bypasses the upstream components of the tumor necrosis factor receptor signaling pathway and directly interacts with the IKK complex to selectively activate the NF-kappaB pathway without affecting the JNK pathway. Selective NF-kappaB activation by K13 might represent a novel strategy employed by the virus to promote latency. PMID:17597077

Matta, Hittu; Mazzacurati, Lucia; Schamus, Sandra; Yang, Tianbing; Sun, Qinmiao; Chaudhary, Preet M

2007-08-24

155

Basal and Human Papillomavirus E6 Oncoprotein-Induced Degradation of Myc Proteins by the Ubiquitin Pathway  

Microsoft Academic Search

We have previously shown that the degradation of c-myc and N-myc in vitro is mediated by the ubiquitin system. However, the role of the system in targeting the myc proteins in vivo and the identity of the conjugating enzymes and possible ancillary proteins involved has remained obscure. Here we report that the degradation of the myc proteins in cells is

Shlomit Gross-Mesilaty; Eyal Reinstein; Beatrice Bercovich; Karin E. Tobias; Alan L. Schwartz; Chaim Kahana; Aaron Ciechanover

1998-01-01

156

NF-?B signalling is attenuated by the E7 protein from cutaneous human papillomaviruses.  

PubMed

The high-risk Alpha-types of human papillomavirus (HPV) are the causative agent of cervical cancer, which is the second major cause of death among women worldwide. Recent investigations have shown that E7 from the Alpha-papillomavirus HPV-16 interacts with IKK? and IKK? of the IKK complex in the NF-?B pathway leading to an attenuation of the activity. There is a possible link between development of non-melanoma skin cancer and cutaneous Beta-papillomavirus but if these HPV types attenuate the NF-?B pathway is unclear. Seven different E7 proteins, representing four out of the five different species of the Beta genus (HPV-20, -37, -38, -92, -93 and -96) and one from the Gamma genus (HPV-4) were investigated for potential modulation of the NF-?B pathway in U2OS cells. Our results demonstrate that E7 from all the cutaneous HPV types were capable of inhibiting the NF-?B activity as well as E7 from HPV-16. In addition, E7 proteins from the cutaneous HPV types demonstrated interaction with IKK? but not with IKK?. The deregulation of the NF-?B pathway by cutaneous HPVs might contribute to the pathogenesis of non-melanoma skin cancers and its precursors. PMID:22776252

Byg, Luise M; Vidlund, Jessica; Vasiljevic, Natasa; Clausen, Dorte; Forslund, Ola; Norrild, Bodil

2012-10-01

157

Metastasis-associated protein 1 (MTA1) is an essential downstream effector of the c-MYC oncoprotein  

PubMed Central

The c-myc oncogene is among the most commonly overexpressed genes in human cancer. c-myc encodes a basic helix–loop–helix/leucine zipper (bHLH/LZ) transcription factor (c-MYC) that activates a cascade of downstream targets that ultimately mediate cellular transformation. Although a large number of genes are regulated by c-MYC, only a few have been functionally linked to c-MYC-mediated transformation. By expression profiling, the metastasis-associated protein 1 (MTA1) gene was identified here as a target of the c-MYC oncoprotein in primary human cells, a result confirmed in human cancer cells. MTA1 itself has been previously implicated in cellular transformation, in part through its ability to regulate the epithelial-to-mesenchymal transition and metastasis. MTA1 is a component of the Mi-2/nucleosome remodeling and deacetylating (NURD) complex that contains both histone deacetylase and nucleosome remodeling activity. The data reported here demonstrate that endogenous c-MYC binds to the genomic MTA1 locus and recruits transcriptional coactivators. Most importantly, short hairpin RNA (shRNA)-mediated knockdown of MTA1 blocks the ability of c-MYC to transform mammalian cells. These data implicate MTA1 and the Mi-2/NURD complex as one of the first downstream targets of c-MYC function that are essential for the transformation potential of c-MYC. PMID:16172399

Zhang, Xiao-yong; DeSalle, Lauren M.; Patel, Jagruti H.; Capobianco, Anthony J.; Yu, Duonan; Thomas-Tikhonenko, Andrei; McMahon, Steven B.

2005-01-01

158

Identification of Relevant Conformational Epitopes on the HER2 Oncoprotein by Using Large Fragment Phage Display (LFPD)  

PubMed Central

We developed a new phage-display based approach, the Large Fragment Phage Display (LFPD), that can be used for mapping conformational epitopes on target molecules of immunological interest. LFPD uses a simplified and more effective phage-display approach in which only a limited set of larger fragments (about 100 aa in length) are expressed on the phage surface. Using the human HER2 oncoprotein as a target, we identified novel B-cell conformational epitopes. The same homologous epitopes were also detected in rat HER2 and all corresponded to the epitopes predicted by computational analysis (PEPITO software), showing that LFPD gives reproducible and accurate results. Interestingly, these newly identified HER2 epitopes seem to be crucial for an effective immune response against HER2-overexpressing breast cancers and might help discriminating between metastatic breast cancer and early breast cancer patients. Overall, the results obtained in this study demonstrated the utility of LFPD and its potential application to the detection of conformational epitopes on many other molecules of interest, as well as, the development of new and potentially more effective B-cell conformational epitopes based vaccines. PMID:23555577

Gabrielli, Federico; Salvi, Roberto; Garulli, Chiara; Kalogris, Cristina; Arima, Serena; Tardella, Luca; Monaci, Paolo; Pupa, Serenella M.; Tagliabue, Elda; Montani, Maura; Quaglino, Elena; Stramucci, Lorenzo; Curcio, Claudia

2013-01-01

159

Dysregulating IRES-dependent translation contributes to over-expression of the Aurora A kinase onco-protein  

PubMed Central

Over-expression of the oncoprotein, Aurora A kinase occurs in multiple types of carcinomas, often early during cell transformation. To identify mechanism(s) contributing to enhanced Aurora A protein expression, we examined normal human lung fibroblast and breast epithelial cells and compared them to non-tumorigenic breast (MCF10A and MCF12A) and tumorigenic breast and cervical epithelial cell lines (MCF-7 and HeLa S3, respectively). A subset of these immortalized lines (MCF10, MCF12A, and HeLa S3) exhibited increased levels of Aurora A protein, independent of tumorigenicity. The increase in Aurora A protein expression in these immortalized cells was not due to increased transcription/RNA stability, protein half-life or cap-dependent translation. Assays utilizing monocistronic and dicistronic RNA constructs revealed that the Aurora A 5? leader contains an internal ribosomal entry site (IRES), which is regulated through the cell cycle, peaking in G2/M phase. Moreover, IRES activity was increased in the immortalized cell lines in which Aurora A protein expression was also enhanced. Additional assays indicated that the increased internal initiation is specific to the Aurora A IRES and may be an early event during cancer progression. Taken together, these results identify a novel mechanism contributing to Aurora A kinase over-expression and possibly to immortalization leading to carcinogenesis. PMID:23661421

Dobson, Tara; Chen, Juan; Krushel, Les A.

2014-01-01

160

The oncoprotein HBXIP upregulates PDGFB via activating transcription factor Sp1 to promote the proliferation of breast cancer cells  

SciTech Connect

Highlights: •HBXIP is able to upregulate the expression of PDGFB in breast cancer cells. •HBXIP serves as a coactivator of activating transcription factor Sp1. •HBXIP stimulates the PDGFB promoter via activating transcription factor Sp1. •HBXIP promotes the proliferation of breast cancer cell via upregulating PDGFB. -- Abstract: We have reported that the oncoprotein hepatitis B virus X-interacting protein (HBXIP) acts as a novel transcriptional coactivator to promote proliferation and migration of breast cancer cells. Previously, we showed that HBXIP was able to activate nuclear factor-?B (NF-?B) in breast cancer cells. As an oncogene, the platelet-derived growth factor beta polypeptide (PDGFB) plays crucial roles in carcinogenesis. In the present study, we found that both HBXIP and PDGFB were highly expressed in breast cancer cell lines. Interestingly, HBXIP was able to increase transcriptional activity of NF-?B through PDGFB, suggesting that HBXIP is associated with PDGFB in the cells. Moreover, HBXIP was able to upregulate PDGFB at the levels of mRNA, protein and promoter in the cells. Then, we identified that HBXIP stimulated the promoter of PDGFB through activating transcription factor Sp1. In function, HBXIP enhanced the proliferation of breast cancer cells through PDGFB in vitro. Thus, we conclude that HBXIP upregulates PDGFB via activating transcription factor Sp1 to promote proliferation of breast cancer cells.

Zhang, Yingyi; Zhao, Yu; Li, Leilei; Shen, Yu; Cai, Xiaoli [Department of Biochemistry, College of Life Sciences, Nankai University, Tianjin 300071 (China)] [Department of Biochemistry, College of Life Sciences, Nankai University, Tianjin 300071 (China); Zhang, Xiaodong, E-mail: zhangxd@nankai.edu.cn [Department of Cancer Research, Institute for Molecular Biology, College of Life Sciences, Nankai University, Tianjin 300071 (China)] [Department of Cancer Research, Institute for Molecular Biology, College of Life Sciences, Nankai University, Tianjin 300071 (China); Ye, Lihong, E-mail: yelihong@nankai.edu.cn [Department of Biochemistry, College of Life Sciences, Nankai University, Tianjin 300071 (China)] [Department of Biochemistry, College of Life Sciences, Nankai University, Tianjin 300071 (China)

2013-05-03

161

Oncogenic nexus of cancerous inhibitor of protein phosphatase 2A (CIP2A): An oncoprotein with many hands  

PubMed Central

Oncoprotein CIP2A a Cancerous Inhibitor of PP2A forms an “oncogenic nexus” by virtue of its control on PP2A and MYC stabilization in cancer cells. The expression and prognostic function of CIP2A in different solid tumors including colorectal carcinoma, head & neck cancers, gastric cancers, lung carcinoma, cholangiocarcinoma, esophageal cancers, pancreatic carcinoma, brain cancers, breast carcinoma, bladder cancers, ovarian carcinoma, renal cell carcinomas, tongue cancers, cervical carcinoma, prostate cancers, and oral carcinoma as well as a number of hematological malignancies are just beginning to emerge. Herein, we reviewed the recent progress in our understanding of (1) how an “oncogenic nexus” of CIP2A participates in the tumorigenic transformation of cells and (2) how we can prospect/view the clinical relevance of CIP2A in the context of cancer therapy. The review will try to understand the role of CIP2A (a) as a biomarker in cancers and evaluate the prognostic value of CIP2A in different cancers (b) as a therapeutic target in cancers and (c) in drug response and developing chemo-resistance in cancers. PMID:25015035

De, Pradip; Carlson, Jennifer; Leyland-Jones, Brian; Dey, Nandini

2014-01-01

162

Interplay Between Oncoproteins and Antioxidant Enzymes in Esophageal Carcinoma Treated Without and With Chemoradiotherapy: A Prospective Study  

SciTech Connect

Purpose: To analyze p53, bcl-2, c-myc, and cyclooxygenase-2 protein expression changes and examine their relationship with various antioxidant enzymes in esophageal carcinoma patients. Methods and Materials: Patients in Group 1 underwent transhiatal esophagectomy and those in Group 2 were administered chemoradiotherapy followed by surgery after 4 weeks of neoadjuvant therapy. Results: The relationship analysis among the various protein markers and antioxidant enzymes showed an inverse correlation between bcl-2 and superoxide dismutase/catalase in tumor tissues, irrespective of the treatment arm followed. An important positive association was observed between bcl-2 and reduced glutathione levels in the tumor tissue of patients receiving neoadjuvant therapy. Another apoptosis-modulating marker, c-myc, in the tumor tissue of Group 2 patients showed similar pattern levels (high and low) as that of superoxide dismutase/catalase. The association of cyclooxygenase-2 and p53 with various antioxidant enzymes showed a significant positive correlation between cyclooxygenase-2 expression and catalase activity and an inverse trend between p53 expression and superoxide dismutase and catalase activity in the tumor tissue of patients given neoadjuvant therapy. In addition, patients with overexpressed p53 protein levels had lower glutathione peroxidase enzyme levels and vice versa in the tumor tissue of patients who had undergone surgery as their main mode of treatment. Conclusion: The results of this study broaden the insight into the relationships shared among oncoproteins and the antioxidant defense system, and this could be helpful in the clinical management of esophageal carcinoma.

Kaur, Tranum [Department of Biophysics, Postgraduate Institute of Medical Education and Research, Chandigarh (India); Gupta, Rajesh [Department of General Surgery, Postgraduate Institute of Medical Education and Research, Chandigarh (India); Vaiphei, Kim [Department of Histopathology, Postgraduate Institute of Medical Education and Research, Chandigarh (India); Kapoor, Rakesh [Department of Radiotherapy, Postgraduate Institute of Medical Education and Research, Chandigarh (India); Gupta, N.M. [Department of General Surgery, Postgraduate Institute of Medical Education and Research, Chandigarh (India); Khanduja, K.L. [Department of Biophysics, Postgraduate Institute of Medical Education and Research, Chandigarh (India); Department of Biophysics, Postgraduate Institute of Medical Education and Research, Chandigarh (India)], E-mail: klkhanduja@gmail.com

2008-02-01

163

Altered nuclear co-factor switching in retinoic resistant variants of the PML-RAR? oncoprotein of acute promyelocytic leukemia†  

PubMed Central

Acute Promyelocytic Leukemia (APL) results from a reciprocal translocation that fuses the gene for the PML tumor suppressor to that encoding the retinoic acid receptor alpha (RAR?). The resulting PML-RAR? oncogene product interferes with multiple regulatory pathways associated with myeloid differentiation, including normal PML and RAR? functions. The standard treatment for APL includes anthracycline-based chemotherapeutic agents plus the RAR? agonist all-trans retinoic acid (ATRA). Relapse, which is often accompanied by ATRA resistance, occurs in an appreciable frequency of treated patients. One potential mechanism suggested by model experiments featuring the selection of ATRA resistant APL cell lines involves ATRA resistant versions of the PML-RAR? oncogene, where the relevant mutations localize to the RAR? ligand-binding domain (LBD). Such mutations may act by compromising agonist binding, but other mechanisms are possible. Here, we studied the molecular consequence of ATRA resistance by use of circular dichroism, protease resistance, and fluorescence anisotropy assays employing peptides derived from the NCOR nuclear co-repressor and the ACTR nuclear co-activator. The consequences of the mutations on global structure and co-factor interaction functions were assessed quantitatively, providing insights into the basis of agonist resistance. Attenuated co-factor switching and increased protease resistance represent features of the LBDs of ATRA-resistant PML-RAR?, and these properties may be recapitulated in the full-length oncoproteins. PMID:22228505

Farris, Mindy; Lague, Astrid; Manuelyan, Zara; Statnekov, Jacob; Francklyn, Christopher

2011-01-01

164

Transforming properties of the cottontail rabbit papillomavirus oncoproteins Le6 and SE6 and of the E8 protein.  

PubMed Central

Cottontail rabbit papillomavirus induces on cottontail and domestic rabbits papillomas which progress at a high frequency to carcinoma. The virus encodes three transforming proteins; one is translated from open reading frame (ORF) E7 and binds the retinoblastoma protein, and two, LE6 and SE6, are translated from the first and second ATGs of ORF E6, respectively. Here we show that neither of the E6 proteins coprecipitated with p53 in vitro, nor did they bind to a recently identified E6-binding protein (J. J. Chen, C. E. Reid, V. Band, and E. Androphy, Science 269:529-531, 1995). This protein was shown to bind to the E6 proteins of the high-risk human papillomairus types 16 and 18 but not to the low-risk human papillomavirus types VI and II. In-frame deletions cloned into the pZipNeo vector were used to identify structural features of SE6 and LE6 important for transformation of NIH 3T3 cells. Three deletions covering the amino-terminal half of SE6 did not transform cells. In two of the three deletions, two Cys-X-X-Cys motifs were deleted, each deletion preventing the formation of one of the potential small Zn fingers of SE6. Among the LE6 deletions, only one had a reduced transformation efficiency, while seven transformed cells at least as efficiently as wild-type LE6. In each of three of these seven mutants, two Cys-X-X-Cys motifs were deleted. None of the three amino acid deletions which abolished transformation by SE6 reduced transformation by LE6. Furthermore, transformation did not correlate with the level of SE6 or LE6 proteins detectable. ORF E8 colinear with ORF E6, which could generate a 50-amino-acid protein with a hydrophobic segment, did not transform cells when cloned into the pZipNeo vector. However, mutation of the E8 ATG, which did not alter the amino acid sequence of LE6, increased transformation by LE6 without affecting the level of LE6 expression. The data suggest that transformation by the E6 proteins is not mediated by interfering with p53 function or through binding to the E6-binding protein. Furthermore, different structural features are important to maintain transformation functions and protein stability of LE6 and SE6. Finally, E8 seems not to be a transforming protein but rather appears to modulate transformation bv LE6. PMID:8648665

Harry, J B; Wettstein, F O

1996-01-01

165

Activation of Stat3 Transcription Factor by Herpesvirus Saimiri STP-A Oncoprotein  

PubMed Central

The saimiri transforming protein (STP) oncogene of Herpesvirus saimiri subgroup A strain 11 (STP-A11) is not required for viral replication but is required for lymphoid cell immortalization in culture and lymphoma induction in primates. We previously showed that STP-A11 interacts with cellular Src kinase through its SH2 binding motif and that this interaction elicits Src signal transduction. Here we demonstrate that STP-A11 interacts with signal transducer and activator of transcription 3 (Stat3) independently of Src association and that the amino-terminal short proline-rich motif of STP-A11 and the central linker region of Stat3 are necessary for their interaction. STP-A11 formed a triple complex with Src kinase and Stat3 where Src kinase phosphorylated Stat3, resulting in the nuclear localization and transcriptional activation of Stat3. Consequently, the constitutively active Stat3 induced by STP-A11 elicited cellular signal transduction, which ultimately induced cell survival and proliferation upon serum deprivation. Furthermore, this activity was strongly correlated with the induction of Fos, cyclin D1, and Bcl-XL expression. These results demonstrate that STP-A11 independently targets two important cellular signaling molecules, Src and Stat3, and that these proteins cooperate efficiently to induce STP-A11-mediated transformation. PMID:15163742

Chung, Young-Hwa; Cho, Nam-hyuk; Garcia, Maria Ines; Lee, Sun-Hwa; Feng, Pinghui; Jung, Jae U.

2004-01-01

166

Human papillomavirus type 16 E7 perturbs DREAM to promote cellular proliferation and mitotic gene expression.  

PubMed

The study of the small DNA tumor viruses continues to provide valuable new insights into oncogenesis and fundamental biological processes. Although much has already been revealed about how the human papillomaviruses (HPVs) can transform cells and contribute to cervical and oropharyngeal cancer, there clearly is much more to learn. In this issue of Oncogene, Pang et al., doi:10.1038/onc.2013.426, demonstrate that the high-risk HPV16 E7 oncogene can promote cellular proliferation by interacting with the DREAM (DP, RB-like, E2F and MuvB) complex at two distinct phases of the cell cycle. Consistent with earlier work, HPV16 E7 can bind to the retinoblastoma tumor suppressor (RB) family member p130 (RBL2) protein and promote its proteasome-mediated destruction thereby disrupting the DREAM complex and can prevent exit from the cell cycle into quiescence. In addition, they demonstrate that HPV16 E7 can bind to MuvB core complex in association with BMYB and FOXM1 and activate gene expression during the G2 and M phase of the cell cycle. Thus, HPV16 E7 acts to prevent exit from the cell cycle entry and promotes mitotic proliferation and may account for the high levels of FOXM1 often observed in poor-risk cervical cancers. PMID:24166507

DeCaprio, J A

2014-07-31

167

Physica E 7 (2000) 322325 www.elsevier.nl/locate/physe  

E-print Network

-743-72-6011; fax: +81-743-72-6019. E-mail address: sunyu@ms.aist-nara.ac.jp (Y. Kanemitsu) can be implanted. PII: S 1386-9477(99)00333-1 #12;Y. Kanemitsu et al. / Physica E 7 (2000) 322­325 323 Fig. 1

Atwater, Harry

168

HPV16 E7 Protein and hTERT Proteins Defective for Telomere Maintenance Cooperate to Immortalize Human Keratinocytes  

PubMed Central

Previous studies have shown that wild-type human telomerase reverse transcriptase (hTERT) protein can functionally replace the human papillomavirus type 16 (HPV-16) E6 protein, which cooperates with the viral E7 protein in the immortalization of primary keratinocytes. In the current study, we made the surprising finding that catalytically inactive hTERT (hTERT-D868A), elongation-defective hTERT (hTERT-HA), and telomere recruitment-defective hTERT (hTERT N+T) also cooperate with E7 in mediating bypass of the senescence blockade and effecting cell immortalization. This suggests that hTERT has activities independent of its telomere maintenance functions that mediate transit across this restriction point. Since hTERT has been shown to have a role in gene activation, we performed microarray studies and discovered that E6, hTERT and mutant hTERT proteins altered the expression of highly overlapping sets of cellular genes. Most important, the E6 and hTERT proteins induced mRNA and protein levels of Bmi1, the core subunit of the Polycomb Group (PcG) complex 1. We show further that Bmi1 substitutes for E6 or hTERT in cell immortalization. Finally, tissue array studies demonstrated that expression of Bmi1 increased with the severity of cervical dysplasia, suggesting a potential role in the progression of cervical cancer. Together, these data demonstrate that hTERT has extra-telomeric activities that facilitate cell immortalization and that its induction of Bmi1 is one potential mechanism for mediating this activity. PMID:23592995

Miller, Jonathan; Dakic, Aleksandra; Chen, Renxiang; Palechor-Ceron, Nancy; Dai, Yuhai; Kallakury, Bhaskar; Schlegel, Richard; Liu, Xuefeng

2013-01-01

169

Identification of target genes of synovial sarcoma-associated fusion oncoprotein using human pluripotent stem cells  

SciTech Connect

Highlights: ? We tried to identify targets of synovial sarcoma (SS)-associated SYT–SSX fusion gene. ? We established pluripotent stem cell (PSC) lines with inducible SYT–SSX gene. ? SYT–SSX responsive genes were identified by the induction of SYT–SSX in PSC. ? SS-related genes were selected from database by in silico analyses. ? 51 genes were finally identified among SS-related genes as targets of SYT–SSX in PSC. -- Abstract: Synovial sarcoma (SS) is a malignant soft tissue tumor harboring chromosomal translocation t(X; 18)(p11.2; q11.2), which produces SS-specific fusion gene, SYT–SSX. Although precise function of SYT–SSX remains to be investigated, accumulating evidences suggest its role in gene regulation via epigenetic mechanisms, and the product of SYT–SSX target genes may serve as biomarkers of SS. Lack of knowledge about the cell-of-origin of SS, however, has placed obstacle in the way of target identification. Here we report a novel approach to identify SYT–SSX2 target genes using human pluripotent stem cells (hPSCs) containing a doxycycline-inducible SYT–SSX2 gene. SYT–SSX2 was efficiently induced both at mRNA and protein levels within three hours after doxycycline administration, while no morphological change of hPSCs was observed until 24 h. Serial microarray analyses identified genes of which the expression level changed more than twofold within 24 h. Surprisingly, the majority (297/312, 95.2%) were up-regulated genes and a result inconsistent with the current concept of SYT–SSX as a transcriptional repressor. Comparing these genes with SS-related genes which were selected by a series of in silico analyses, 49 and 2 genes were finally identified as candidates of up- and down-regulated target of SYT–SSX, respectively. Association of these genes with SYT–SSX in SS cells was confirmed by knockdown experiments. Expression profiles of SS-related genes in hPSCs and human mesenchymal stem cells (hMSCs) were strikingly different in response to the induction of SYT–SSX, and more than half of SYT–SSX target genes in hPSCs were not induced in hMSCs. These results suggest the importance of cellular context for correct understanding of SYT–SSX function, and demonstrated how our new system will help to overcome this issue.

Hayakawa, Kazuo [Department of Tissue Regeneration, Institute for Frontier Medical Sciences, Kyoto University, Kyoto (Japan) [Department of Tissue Regeneration, Institute for Frontier Medical Sciences, Kyoto University, Kyoto (Japan); Department of Cell Growth and Differentiation, Center for iPS Cell Research and Application, Kyoto University, Kyoto (Japan); Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Nagoya City University, Nagoya (Japan); Ikeya, Makoto [Department of Cell Growth and Differentiation, Center for iPS Cell Research and Application, Kyoto University, Kyoto (Japan)] [Department of Cell Growth and Differentiation, Center for iPS Cell Research and Application, Kyoto University, Kyoto (Japan); Fukuta, Makoto [Department of Tissue Regeneration, Institute for Frontier Medical Sciences, Kyoto University, Kyoto (Japan) [Department of Tissue Regeneration, Institute for Frontier Medical Sciences, Kyoto University, Kyoto (Japan); Department of Cell Growth and Differentiation, Center for iPS Cell Research and Application, Kyoto University, Kyoto (Japan); Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Nagoya City University, Nagoya (Japan); Woltjen, Knut [Department of Reprogramming Sciences, Center for iPS Cell Research and Application, Kyoto University, Kyoto (Japan)] [Department of Reprogramming Sciences, Center for iPS Cell Research and Application, Kyoto University, Kyoto (Japan); Tamaki, Sakura; Takahara, Naoko; Kato, Tomohisa; Sato, Shingo [Department of Tissue Regeneration, Institute for Frontier Medical Sciences, Kyoto University, Kyoto (Japan)] [Department of Tissue Regeneration, Institute for Frontier Medical Sciences, Kyoto University, Kyoto (Japan); Otsuka, Takanobu [Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Nagoya City University, Nagoya (Japan)] [Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Nagoya City University, Nagoya (Japan); Toguchida, Junya, E-mail: togjun@frontier.kyoto-u.ac.jp [Department of Tissue Regeneration, Institute for Frontier Medical Sciences, Kyoto University, Kyoto (Japan) [Department of Tissue Regeneration, Institute for Frontier Medical Sciences, Kyoto University, Kyoto (Japan); Department of Cell Growth and Differentiation, Center for iPS Cell Research and Application, Kyoto University, Kyoto (Japan); Department of Orthopaedic Surgery, Graduate School of Medicine, Kyoto University, Kyoto (Japan)

2013-03-22

170

Molecular mobility of nematic E7 confined to molecular sieves with a low filling degree.  

PubMed

The nematic liquid crystalline mixture E7 was confined with similar filling degrees to molecular sieves with constant composition but different pore diameters (from 2.8 to 6.8 nm). Fourier transform infrared analysis proved that the E7 molecules interact via the cyanogroup with the pore walls of the molecular sieves. The molecular dynamics of the system was investigated by broadband dielectric spectroscopy (10(-2)-10(9) Hz) covering a wide temperature range of approximately 200 K from temperatures well above the isotropic-nematic transition down to the glass transition of bulk E7. A variety of relaxation processes is observed including two modes that are located close to the bulk behavior in its temperature dependence. For all confined samples, two relaxation processes, at frequencies lower than the processes observed for the bulk, were detected. At lower temperatures, their relaxation rates have different temperature dependencies whereas at higher temperatures, they seem to collapse into one chart. The temperature dependence of the slowest process (S-process) obeys the Vogel-Fulcher-Tammann law indicating a glassy dynamics of the E7 molecules anchored to the pore surface. The pore size dependence of both the Vogel temperature and fragility revealed a steplike transition around 4 nm pore size, which indicates a transition from a strong to a fragile behavior. The process with a relaxation rate in between the bulklike and the S-process (I-process) shows no dependence on the pore size. The agreement of the I-process with the behavior of a 5CB surface layer adsorbed on nonporous silica leads to the assignment of E7 molecules anchored at the outer surface of the microcrystals of the molecular sieves. PMID:20550409

Brás, A R; Frunza, S; Guerreiro, L; Fonseca, I M; Corma, A; Frunza, L; Dionísio, M; Schönhals, A

2010-06-14

171

Targeting Oncoprotein Stability Overcomes Drug Resistance Caused by FLT3 Kinase Domain Mutations  

PubMed Central

FLT3 is the most frequently mutated kinase in acute myeloid leukemia (AML). Internal tandem duplications (ITDs) in the juxta-membrane region constitute the majority of activating FLT3 mutations. Several FLT3 kinase inhibitors were developed and tested in the clinic with significant success. However, recent studies have reported the development of secondary drug resistance in patients treated with FLT3 inhibitors. Since FLT3-ITD is an HSP90 client kinase, we here explored if targeting the stability of drug-resistant FLT3 mutant protein could be a potential therapeutic option. We observed that HSP90 inhibitor treatment resulted in the degradation of inhibitor-resistant FLT3-ITD mutants and selectively induced toxicity in cells expressing FLT3-ITD mutants. Thus, HSP90 inhibitors provide a potential therapeutic choice to overcome secondary drug resistance following TKI treatment in FLT3-ITD positive AML. PMID:24849514

Duyster, Justus

2014-01-01

172

Arsenic trioxide amplifies cisplatin toxicity in human tubular cells transformed by HPV-16 E6/E7 for further therapeutic directions in renal cell carcinoma.  

PubMed

Human papillomavirus (HPV) DNA integrations may affect therapeutic responses in cancers through ATM network-related DNA damage response (DDR). We studied whether cisplatin-induced DDR was altered in human HK-2 renal tubular cells immortalized by HPV16 E6/E7 genes. Cytotoxicity assays utilized thiazolyl blue dye and DDR was identified by gene expression differences, double-strand DNA breaks, ATM promoter activity, and analysis of cell cycling and side population cells. After cisplatin, HK-2 cells showed greater ATM promoter activity indicating activation of this network, but DDR was muted, since little ?H2AX was expressed, DNA strand breaks were absent and cells continued cycling. When HK-2 cells were treated with the MDM2 antagonist inducing p53, nutlin-3, or p53 transcriptional activator, tenovin-1, cell growth decreased but cisplatin toxicity was unaffected. By contrast, arsenic trioxide, which by inhibiting wild-type p53-induced phosphatase-1 that serves responses downstream of p53, and by depolymerizing tubulin, synergistically enhanced cisplatin cytotoxicity including loss of SP cells. Our findings demonstrated that HPV16 E6/E7 altered DDR through p53-mediated cell growth controls, which may be overcome by targeting of WIP1 and other processes, and thus should be relevant for treating renal cell carcinoma. PMID:25444910

Dogra, Samriti; Bandi, Sriram; Viswanathan, Preeti; Gupta, Sanjeev

2015-01-28

173

The oncoprotein HBXIP enhances migration of breast cancer cells through increasing filopodia formation involving MEKK2/ERK1/2/Capn4 signaling.  

PubMed

We have reported that the oncoprotein hepatitis B X-interacting protein (HBXIP) plays a crucial role in the promotion of migration of breast cancer cells. Lamellipodia and filopodia protrusions play fundamental roles, involving dynamic cytoskeleton reorganization in the metastasis of cancer. Here, we observed that the expression levels of both HBXIP and Calpain small subunit 1 (Capn4) were very high in clinical metastatic lymph nodes of breast tumor. Then, we found that HBXIP was able to up-regulate Capn4 at the levels of promoter, mRNA and protein in breast cancer cells through activation of ERK1/2. Moreover, we showed that HBXIP activated ERK1/2 through up-regulating MEKK2. In function, we revealed that HBXIP increased the filopodia formation through Capn4, resulting in cell migration. Thus, we conclude that the oncoprotein HBXIP enhances the migration of breast cancer through increasing filopodia formation involving MEKK2/ERK1/2/Capn4 signaling. Therapeutically, HBXIP may serve as a novel target in breast cancer. PMID:25304384

Li, Yinghui; Zhang, Zhao; Zhou, Xiaolei; Li, Leilei; Liu, Qian; Wang, Zhen; Bai, Xiao; Zhao, Yu; Shi, Hui; Zhang, Xiaodong; Ye, Lihong

2014-12-28

174

Detection of JC virus DNA sequence and expression of the viral oncoprotein, tumor antigen, in brain of immunocompetent patient with oligoastrocytoma.  

PubMed Central

We describe molecular and clinical findings in an immunocompetent patient with an oligoastrocytoma and the concomitant presence of the human papovavirus, JC virus (JCV), which is the etiologic agent of the subacute, debilitating demyelinating disease, progressive multifocal leukoencephalopathy. Histologic review revealed a glial neoplasm consisting primarily of a moderately cellular oligodendroglioma with distinct areas of a fibrillary astrocytoma. Immunohistochemical analysis revealed nuclear staining of tumor cells with antibodies against the viral oncoprotein [tumor antigen (T antigen)], the proliferation marker (Ki67), and the cellular proliferation regulator (p53). Using primers specific to the JCV control region, PCR yielded amplified DNA that was identical to the control region of the Mad-4 strain of the virus. PCR analysis demonstrated the presence of the genome for the viral oncoprotein, T antigen, and results from primer extension studies revealed synthesis of the viral early RNA for T antigen in the tumor tissues. The presence of viral T antigen in the tumor tissue was further demonstrated by immunoblot assay. To our knowledge, this is the first report of the presence of JCV DNA, RNA, and T antigen in tissue in which viral T antigen is localized to tumor cell nuclei and suggests the possible association of JCV with some glial neoplasms. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:8692997

Rencic, A; Gordon, J; Otte, J; Curtis, M; Kovatich, A; Zoltick, P; Khalili, K; Andrews, D

1996-01-01

175

Degradation of the transcription factor Twist, an oncoprotein that promotes cancer metastasis.  

PubMed

Basic helix-loop-helix (bHLH) transcription factor Twist is one of the key inducers of epithelial to mesenchymal transition (EMT) that is a transdifferentiation program associated with embryo development and tumor metastasis. High level of Twist expression is shown to be correlated with cancer malignancy. Although Twist has been reported to be degraded by F-box and leucine-rich repeat protein 14 (FBXL14), the molecular mechanisms by which Twist levels are regulated have not been fully elucidated. In the present study, we identified Twist to be a ubiquitin substrate of ?-transducin repeat-containing protein (?-TRCP), the adaptor subunit of SCF(?-TRCP) (Skp1-Cul1-F-box protein) E3 ligase complex. We observed that depletion of ?-TRCP leads to an accumulation of Twist protein, which could enhance tumor cell motility and cancer metastasis. Moreover, phosphorylation of Twist by inhibitor of KappaB kinase ? (IKK?) at multiple sites triggers its cytoplasmic translocation and the destruction by SCF(?-TRCP). Thus, our results provide the potential molecular mechanism of how the mesenchymal marker Twist is degraded, thereby shedding lights into regulation of the EMT, and providing the rationale for development of new therapeutic intervention to achieve better treatment outcomes in human cancer. PMID:23375009

Zhong, Jiateng; Ogura, Kohei; Wang, Zhiwei; Inuzuka, Hiroyuki

2013-01-01

176

EWS-WT1 oncoprotein activates neuronal reprogramming factor ASCL1 and promotes neural differentiation.  

PubMed

The oncogenic fusion gene EWS-WT1 is the defining chromosomal translocation in desmoplastic small round-cell tumors (DSRCT), a rare but aggressive soft tissue sarcoma with a high rate of mortality. EWS-WT1 functions as an aberrant transcription factor that drives tumorigenesis, but the mechanistic basis for its pathogenic activity is not well understood. To address this question, we created a transgenic mouse strain that permits physiologic expression of EWS-WT1 under the native murine Ews promoter. EWS-WT1 expression led to a dramatic induction of many neuronal genes in embryonic fibroblasts and primary DSRCT, most notably the neural reprogramming factor ASCL1. Mechanistic analyses demonstrated that EWS-WT1 directly bound the proximal promoter of ASCL1, activating its transcription through multiple WT1-responsive elements. Conversely, EWS-WT1 silencing in DSRCT cells reduced ASCL1 expression and cell viability. Notably, exposure of DSRCT cells to neuronal induction media increased neural gene expression and induced neurite-like projections, both of which were abrogated by silencing EWS-WT1. Taken together, our findings reveal that EWS-WT1 can activate neural gene expression and direct partial neural differentiation via ASCL1, suggesting agents that promote neural differentiation might offer a novel therapeutic approach to treat DSRCT. PMID:24934812

Kang, Hong-Jun; Park, Jun Hong; Chen, WeiPing; Kang, Soo Im; Moroz, Krzysztof; Ladanyi, Marc; Lee, Sean Bong

2014-08-15

177

Targeting of the HPV-16 E7 protein by RNA aptamers.  

PubMed

The expression of high-risk human papillomavirus E6 and E7 proteins in most cervical tumors raised a considerable interest in the diagnostic and therapeutic applications of functional oligonucleotides (i.e., DNAzymes, ribozymes, and aptamers) directed against HPV targets. Aptamers are short single-stranded oligonucleotides that specifically recognize a wide variety of molecular targets, including HPV proteins. Here, we describe a protocol for the successful isolation of RNA aptamers directed at the recombinant HPV-16 E7 protein through the application of the SELEX method. Once the nucleic acid sequence of a functional aptamer is determined, large amounts of the oligonucleotide can be produced and modified at low cost and high efficiency. The remarkable affinity and specificity of aptamers for their targets make these molecules the next-generation tool for diagnostics and therapeutics of cervical cancer. PMID:25348310

Toscano-Garibay, Julia Dolores; Benítez-Hess, María Luisa; Alvarez-Salas, Luis Marat

2015-01-01

178

Expression of mucosa-related integrin ?E?7 on alveolar T cells in interstitial lung diseases  

PubMed Central

The expression of ?E?7 integrin has been related to the selective retention of lymphocytes in mucosal tissues of gut, urogenital tract and lung. To identify potential disease-associated ?E?7 expression patterns on cells accounting for lymphocytic alveolitis in interstitial lung disease (ILD), ?E expression on CD4+ and CD8+ T cell subsets was evaluated by dual-colour flow cytometry in peripheral blood and bronchoalveolar lavage fluid (BALF) of patients with idiopathic pulmonary fibrosis (IPF; n = 18), hypersensitivity pneumonitis (HP; n = 20) and sarcoidosis (n = 44) in comparison with healthy controls (n = 15). In both healthy individuals and all patient groups the proportion of ?E-bearing T cells in peripheral blood was < 2%, whereas the vast majority of alveolar CD8+ T cells consistently co-expressed ?E. Absolute alveolar CD8+?E+ cell numbers/ml were up to 30-fold increased in HP patients. Proportions of ?E-bearing CD4+ cells in BALF were significantly elevated in IPF (74.0 ± 2.7%) and HP (70.0 ± 2.4%) compared with normals (30.0 ± 1.8%) (mean ± s.e.m.; P < 0.01). In sarcoidosis, the ?E expression on BALF CD4+ cells displayed subgroup dependency: proportions significantly lower than normal were noted in chest radiographic stage I (14.3 ± 1.5%), but increased proportions in stages II (50.0 ± 3.8%) and III (64.0 ± 4.8%). Correlations between common markers of T cell activation or BALF transforming growth factor-beta (TGF-?) bioactivity and ?E expression were not noted. We conclude that the vast majority of alveolar CD8+ T cells consistently express ?E?7 and that distinct patterns of ?E?7 expression on alveolar CD4+ lymphocytes in sarcoidosis are related to the diverse manifestations of the sarcoid inflammatory process in the lung. PMID:10337028

Lohmeyer, J; Friedrich, J; Grimminger, F; Maus, U; Tenter, R; Morr, H; Velcovsky, H G; Seeger, W; Rosseau, S

1999-01-01

179

Protein arginine methyltransferase 5 is a key regulator of the MYCN oncoprotein in neuroblastoma cells.  

PubMed

Approximately half of poor prognosis neuroblastomas (NBs) are characterized by pathognomonic MYCN gene amplification and MYCN over-expression. Here we present data showing that short-interfering RNA mediated depletion of the protein arginine methyltransferase 5 (PRMT5) in cell-lines representative of NBs with MYCN gene amplification leads to greatly impaired growth and apoptosis. Growth suppression is not apparent in the MYCN-negative SH-SY5Y NB cell-line, or in two immortalized human fibroblast cell-lines. Immunoblotting of NB cell-lines shows that high PRMT5 expression is strongly associated with MYCN-amplification (P < 0.004, Mann-Whitney U-test) and immunohistochemical analysis of primary NBs reveals that whilst PRMT5 protein is ubiquitously expressed in the cytoplasm of most cells, MYCN-amplified tumours exhibit pronounced nuclear PRMT5 staining. PRMT5 knockdown in MYCN-overexpressing cells, including the SHEP-21N cell-line with inducible MYCN expression leads to a dramatic decrease in MYCN protein and MYCN-associated cell-death in SHEP-21N cells. Quantitative gene expression analysis and cycloheximide chase experiments suggest that PRMT5 regulates MYCN at a post-transcriptional level. Reciprocal co-immunoprecipitation experiments demonstrated that endogenous PRMT5 and MYCN interact in both SK-N-BE(2)C and NGP cell lines. By using liquid chromatography - tandem mass spectrometry (LC-MS/MS) analysis of immunoprecipitated MYCN protein, we identified several potential sites of arginine dimethylation on the MYCN protein. Together our studies implicate PRMT5 in a novel mode of MYCN post-translational regulation and suggest PRMT5 plays a major role in NB tumorigenesis. Small-molecule inhibitors of PRMT5 may therefore represent a novel therapeutic strategy for neuroblastoma and other cancers driven by the MYCN oncogene. PMID:25475372

Park, Ji Hyun; Szemes, Marianna; Vieira, Gabriella Cunha; Melegh, Zsombor; Malik, Sally; Heesom, Kate J; Von Wallwitz-Freitas, Laura; Greenhough, Alexander; Brown, Keith W; Zheng, Y George; Catchpoole, Daniel; Deery, Michael J; Malik, Karim

2014-11-15

180

Targeting Epstein-Barr virus oncoprotein LMP1-mediated glycolysis sensitizes nasopharyngeal carcinoma to radiation therapy.  

PubMed

Our goal in this work was to illustrate the Epstein-Barr virus (EBV)-modulated global biochemical profile and provide a novel metabolism-related target to improve the therapeutic regimen of nasopharyngeal carcinoma (NPC). We used a metabolomics approach to investigate EBV-modulated metabolic changes, and found that the exogenous overexpression of the EBV-encoded latent membrane protein 1 (LMP1) significantly increased glycolysis. The deregulation of several glycolytic genes, including hexokinase 2 (HK2), was determined to be responsible for the reprogramming of LMP1-mediated glucose metabolism in NPC cells. The upregulation of HK2 elevated aerobic glycolysis and facilitated proliferation by blocking apoptosis. More importantly, HK2 was positively correlated with LMP1 in NPC biopsies, and high HK2 levels were significantly associated with poor overall survival of NPC patients following radiation therapy. Knockdown of HK2 effectively enhanced the sensitivity of LMP1-overexpressing NPC cells to irradiation. Finally, c-Myc was demonstrated to be required for LMP1-induced upregulation of HK2. The LMP1-mediated attenuation of the PI3-K/Akt-GSK3beta-FBW7 signaling axis resulted in the stabilization of c-Myc. These findings indicate a close relationship between EBV and glycolysis in NPC. Notably, LMP1 is the key regulator of the reprogramming of EBV-mediated glycolysis in NPC cells. Given the importance of EBV-mediated deregulation of glycolysis, anti-glycolytic therapy might represent a worthwhile avenue of exploration in the treatment of EBV-related cancers. PMID:24662831

Xiao, L; Hu, Z-Y; Dong, X; Tan, Z; Li, W; Tang, M; Chen, L; Yang, L; Tao, Y; Jiang, Y; Li, J; Yi, B; Li, B; Fan, S; You, S; Deng, X; Hu, F; Feng, L; Bode, A M; Dong, Z; Sun, L-Q; Cao, Y

2014-09-11

181

Radiosensitization of Oropharyngeal Squamous Cell Carcinoma Cells by Human Papillomavirus 16 Oncoprotein E6*I  

SciTech Connect

Purpose: Patients with oropharyngeal squamous cell carcinoma (OSCC) whose disease is associated with high-risk human papillomavirus (HPV) infection have a significantly better outcome than those with HPV-negative disease, but the reasons for the better outcome are not known. We postulated that they might relate to an ability of HPV proteins to confer a better response to radiotherapy, a commonly used treatment for OSCC. Methods and Materials: We stably expressed the specific splicing-derived isoforms, E6*I and E6*II, or the entire E6 open reading frame (E6total), which gives rise to both full length and E6*I isoforms, in OSCC cell lines. Radiation resistance was measured in clonogenicity assays, p53 activity was measured using transfected reporter genes, and flow cytometry was used to analyze cell cycle and apoptosis. Results: E6*I and E6total sensitized the OSCC cells to irradiation, E6*I giving the greatest degree of radiosensitization (approximately eightfold lower surviving cell fraction at 10 Gy), whereas E6*II had no effect. In contrast to radiosensitivity, E6*I was a weaker inhibitor than E6total of tumor suppressor p53 transactivator activity in the same cells. Flow cytometric analyses showed that irradiated E6*I expressing cells had a much higher G2M:G1 ratio than control cells, indicating that, after G2, cells were diverted from the cell cycle to programmed cell death. Conclusion: This study supports a role for E6*I in the enhanced responsiveness of HPV-positive oropharyngeal carcinomas to p53-independent radiation-induced death.

Pang, Ervinna [Sydney Head and Neck Cancer Institute, Sydney Cancer Centre, Royal Prince Alfred Hospital, NSW (Australia); Discipline of Infectious Diseases and Immunology, University of Sydney, NSW (Australia); Delic, Naomi C. [Sydney Head and Neck Cancer Institute, Sydney Cancer Centre, Royal Prince Alfred Hospital, NSW (Australia); Discipline of Dermatology, University of Sydney, NSW (Australia); Hong, Angela; Zhang Mei [Sydney Head and Neck Cancer Institute, Sydney Cancer Centre, Royal Prince Alfred Hospital, NSW (Australia); Department of Radiation Oncology, Royal Prince Alfred Hospital, NSW (Australia); Rose, Barbara R. [Sydney Head and Neck Cancer Institute, Sydney Cancer Centre, Royal Prince Alfred Hospital, NSW (Australia); Discipline of Infectious Diseases and Immunology, University of Sydney, NSW (Australia); Lyons, J. Guy, E-mail: guy.lyons@sydney.edu.a [Sydney Head and Neck Cancer Institute, Sydney Cancer Centre, Royal Prince Alfred Hospital, NSW (Australia); Discipline of Dermatology, University of Sydney, NSW (Australia)

2011-03-01

182

Lack of the canonical pRB-binding domain in the E7 ORF of artiodactyl papillomaviruses  

E-print Network

Lack of the canonical pRB-binding domain in the E7 ORF of artiodactyl papillomaviruses of papillomavirus (PV) E7 proteins has been implicated in the immortalization and transformation of the host cell. However, sequencing of the complete genomes of bovine papillomavirus type 3 (BPV-3), bovine papillomavirus

DeSalle, Rob

183

A second magnesium ion is critical for ATP binding in the kinase domain of the oncoprotein v-Fps.  

PubMed

The activity of the kinase domain of the oncoprotein v-Fps was found to be sensitive to the concentration of magnesium ions. Plots of initial velocity versus free magnesium concentration are hyperbolic and do not extrapolate to the origin at stoichiometric ATP-Mg, indicating that there are two sites for metal chelation on the enzyme and the second is nonessential for catalysis. The second metal is strongly activating and increases the reaction rate constant almost 20-fold from 0.5 to 8.3 s-1 using 0.2 mM ATP-Mg and 1 mM peptide, EAEIYEAIE. This increase in rate is due to a large increase in the apparent affinity of ATP-Mg at high magnesium concentrations. At 0.5 and 10 mM free Mg2+, KATP-Mg is 3.6 and 0.22 mM, respectively. Extrapolation of the observed affinity of ATP-Mg to zero and infinite free metal indicates that KATP-Mg is greater than 8 mM in the absence of the second metal and 0.1 mM in the presence of the second metal, a minimum 80-fold enhancement. By comparison, free levels of the divalent ion do not influence maximum turnover (kcat) and have only a 2-fold effect on the Km for the peptide substrate between 0.5 and 20 mM free Mg2+. Viscosometric studies indicate that free Mg2+ does not influence the rates of phosphoryl transfer or net product release above 0.5 mM but does affect directly the dissociation constant for ATP-Mg. The Kd for ATP-Mg in the absence and presence of the second metal ion is >32 and 0.4 mM, respectively. At high magnesium concentrations, ATP-Mg and the peptide substrate bind independently, while at lower concentrations (0.5 mM), there is significant negative binding synergism suggesting that the second metal may help to reduce charge repulsion between ATP-Mg and the peptide. The data indicate that the first metal is sufficient for phosphoryl transfer. While the second metal could have some influence on phosphoryl transfer or product binding, it is a potent activator that functions minimally by controlling ATP-Mg binding. PMID:9730835

Saylor, P; Wang, C; Hirai, T J; Adams, J A

1998-09-01

184

Tyrosine B10 triggers a heme propionate hydrogen bonding network loop with glutamine E7 moiety  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer H-bonding network loop by PheB10Tyr mutation is proposed. Black-Right-Pointing-Pointer The propionate group H-bonding network restricted the flexibility of the heme. Black-Right-Pointing-Pointer The hydrogen bonding interaction modulates the electron density of the iron. Black-Right-Pointing-Pointer Propionate H-bonding network loop explains the heme-ligand stabilization. -- Abstract: Propionates, as peripheral groups of the heme active center in hemeproteins have been described to contribute in the modulation of heme reactivity and ligand selection. These electronic characteristics prompted the question of whether the presence of hydrogen bonding networks between propionates and distal amino acids present in the heme ligand moiety can modulate physiological relevant events, like ligand binding association and dissociation activities. Here, the role of these networks was evaluated by NMR spectroscopy using the hemoglobin I PheB10Tyr mutant from Lucina pectinata as model for TyrB10 and GlnE7 hemeproteins. {sup 1}H-NMR results for the rHbICN PheB10Tyr derivative showed chemical shifts of TyrB10 OH{eta} at 31.00 ppm, GlnE7 N{sub {epsilon}1}H/N{sub {epsilon}2}H at 10.66 ppm/-3.27 ppm, and PheE11 C{sub {delta}}H at 11.75 ppm, indicating the presence of a crowded, collapsed, and constrained distal pocket. Strong dipolar contacts and inter-residues crosspeaks between GlnE7/6-propionate group, GlnE7/TyrB10 and TyrB10/CN suggest that this hydrogen bonding network loop between GlnE7, TyrB10, 6-propionate group, and the heme ligand contribute significantly to the modulation of the heme iron electron density as well as the ligand stabilization mechanism. Therefore, the network loop presented here support the fact that the electron withdrawing character of the hydrogen bonding is controlled by the interaction of the propionates and the nearby electronic environments contributing to the modulation of the heme electron density state. Thus, we hypothesize that in hemeproteins with similar electrostatic environment the flexibility of the heme-6-propionate promotes a hydrogen bonding network loop between the 6-propionate, the heme ligand and nearby amino acids, tailoring in this way the electron density in the heme-ligand moiety.

Ramos-Santana, Brenda J., E-mail: brenda.ramos@upr.edu [Department of Chemistry, University of Puerto Rico, Mayagueez Campus, P.O. Box 9019, Mayagueez 00681-9019 (Puerto Rico); Lopez-Garriga, Juan, E-mail: juan.lopez16@upr.edu [Department of Chemistry, University of Puerto Rico, Mayagueez Campus, P.O. Box 9019, Mayagueez 00681-9019 (Puerto Rico)] [Department of Chemistry, University of Puerto Rico, Mayagueez Campus, P.O. Box 9019, Mayagueez 00681-9019 (Puerto Rico)

2012-08-10

185

Silencing of E6/E7 expression in cervical cancer stem-like cells.  

PubMed

Accumulating evidence supports the concept that cancer stem cells (CSCs) are responsible for the tumor recurrence and metastasis, the two major causes of cancer-related death. Therefore, CSC-targeted cancer therapy is important for the future development of more effective and advanced cancer therapy. One of the approaches is to specifically silence oncogene expression in CSCs and inhibit their growth. The significance of this approach is its specificity and ability to avoid multi-drug resistance of CSCs. In this chapter, we will describe a method of silencing HPV oncogenes E6/E7 in human cervical CSCs using HeLa cells as a model system. PMID:25348305

Gu, Wenyi; McMillan, Nigel; Yu, Chengzhong

2015-01-01

186

Simulation evaluation of transition and hover flying qualities of the E-7A STOVL aircraft  

NASA Technical Reports Server (NTRS)

The generalized simulation model developed for the E-7A STOVL fighter-type aircraft configuration has attempted to define the limits of acceptibility for a vertical-to-horizontal-to-vertical flight transition envelope. An effort was also made to determine the control power required during hover and transition, and to evaluate whether the integration of flight and propulsion controls thus far effected achieves good flying qualities throughout the low-speed flight envelope. The results thus obtained furnish a general view of the acceptable transition corridor, expressed in terms of the minimum-climb capability.

Franklin, James A.; Stortz, Michael W.; Gerdes, Ronald M.; Hardy, Gordon H.; Martin, James L.; Engelland, Shawn A.

1988-01-01

187

Herpesvirus ateles Tio can replace herpesvirus saimiri StpC and Tip oncoproteins in growth transformation of monkey and human T cells.  

PubMed

Herpesvirus saimiri group C strains are capable of transforming human and simian T-lymphocyte populations to permanent antigen-independent growth. Two viral oncoproteins, StpC and Tip, that are encoded by a single bicistronic mRNA, act in concert to mediate this phenotype. A closely related New World monkey herpesvirus, herpesvirus ateles, transcribes a single spliced mRNA at an equivalent genome locus. The encoded protein, Tio, has sequence homologies to both StpC and Tip. We inserted the tio sequence of herpesvirus ateles strain 73 into a recombinant herpesvirus saimiri C488 lacking its own stpC/tip oncogene. Simian as well as human T lymphocytes were growth transformed by the chimeric Tio-expressing viruses. Thus, a single herpesvirus protein appears to be responsible for the oncogenic effects of herpesvirus ateles. PMID:15331715

Albrecht, Jens-Christian; Biesinger, Brigitte; Müller-Fleckenstein, Ingrid; Lengenfelder, Doris; Schmidt, Monika; Fleckenstein, Bernhard; Ensser, Armin

2004-09-01

188

Herpesvirus Ateles Tio Can Replace Herpesvirus Saimiri StpC and Tip Oncoproteins in Growth Transformation of Monkey and Human T Cells  

PubMed Central

Herpesvirus saimiri group C strains are capable of transforming human and simian T-lymphocyte populations to permanent antigen-independent growth. Two viral oncoproteins, StpC and Tip, that are encoded by a single bicistronic mRNA, act in concert to mediate this phenotype. A closely related New World monkey herpesvirus, herpesvirus ateles, transcribes a single spliced mRNA at an equivalent genome locus. The encoded protein, Tio, has sequence homologies to both StpC and Tip. We inserted the tio sequence of herpesvirus ateles strain 73 into a recombinant herpesvirus saimiri C488 lacking its own stpC/tip oncogene. Simian as well as human T lymphocytes were growth transformed by the chimeric Tio-expressing viruses. Thus, a single herpesvirus protein appears to be responsible for the oncogenic effects of herpesvirus ateles. PMID:15331715

Albrecht, Jens-Christian; Biesinger, Brigitte; Müller-Fleckenstein, Ingrid; Lengenfelder, Doris; Schmidt, Monika; Fleckenstein, Bernhard; Ensser, Armin

2004-01-01

189

SET oncoprotein overexpression in B-cell chronic lymphocytic leukemia and non-Hodgkin lymphoma: a predictor of aggressive disease and a new treatment target  

PubMed Central

B-cell chronic lymphocytic leukemia (CLL), an incurable leukemia, is characterized by defective apoptosis. We found that the SET oncoprotein, a potent inhibitor of the protein phosphatase 2A (PP2A) tumor suppressor, is overexpressed in primary CLL cells and B-cell non-Hodgkin lymphoma (NHL) cell line cells. In CLL, increased levels of SET correlated significantly with disease severity (shorter time to treatment and overall survival). We developed SET antagonist peptides that bound SET, increased cellular PP2A activity, decreased Mcl-1 expression, and displayed selective cytotoxicity for CLL and NHL cells in vitro. In addition, shRNA for SET was cytotoxic for NHL cells in vitro. The SET antagonist peptide COG449 inhibited growth of NHL tumor xenografts in mice. These data demonstrate that SET is a new treatment target in B-cell malignancies and that SET antagonists represent novel agents for treatment of CLL and NHL. PMID:21844565

Chen, Youwei; Oddo, Jessica; Matta, Karen M.; Neil, Jessica; Davis, Evan D.; Volkheimer, Alicia D.; Lanasa, Mark C.; Friedman, Daphne R.; Goodman, Barbara K.; Gockerman, Jon P.; Diehl, Louis F.; de Castro, Carlos M.; Moore, Joseph O.; Vitek, Michael P.; Weinberg, J. Brice

2011-01-01

190

Oncoprotein protein kinase  

DOEpatents

An isolated polypeptide (JNK) characterized by having a molecular weight of 46kD as determined by reducing SDS-PAGE, having serine and threonine kinase activity, phosphorylating the c-Jun N-terminal activation domain and polynucleotide sequences and method of detection of JNK are provided herein. JNK phosphorylates c-Jun N-terminal activation domain which affects gene expression from AP-1 sites.

Karin, Michael (2565 Chalcedony, San Diego, CA 92122); Hibi, Masahiko (7528 Charmant Dr., No. 418, San Diego, CA 92122); Lin, Anning (8655 Via Mallorca Dr., Apt. 93, La Jolla, CA 92093)

1997-01-01

191

Oncoprotein protein kinase  

DOEpatents

An isolated polypeptide (JNK) characterized by having a molecular weight of 46 kD as determined by reducing SDS-PAGE is disclosed. The polypeptide has serine and threonine kinase activity, phosphorylating the c-Jun N-terminal activation domain and polynucleotide sequences. The method of detection of JNK is also provided. JNK phosphorylates c-Jun N-terminal activation domain which affects gene expression from AP-1 sites. 44 figs.

Karin, M.; Hibi, M.; Lin, A.

1997-02-25

192

The E7 protein of the cottontail rabbit papillomavirus immortalizes normal rabbit keratinocytes and reduces pRb levels, while E6 cooperates in immortalization but neither degrades p53 nor binds E6AP  

SciTech Connect

Human papillomaviruses (HPVs) cause cervical cancer and are associated with the development of non-melanoma skin cancer. A suitable animal model for papillomavirus-associated skin carcinogenesis is the infection of domestic rabbits with the cottontail rabbit papillomavirus (CRPV). As the immortalizing activity of CRPV genes in the natural target cells remains unknown, we investigated the properties of CRPV E6 and E7 in rabbit keratinocytes (RK) and their influence on the cell cycle. Interestingly, CRPV E7 immortalized RK after a cellular crisis but showed no such activity in human keratinocytes. Co-expressed CRPV E6 prevented cellular crisis. The HPV16 or CRPV E7 protein reduced rabbit pRb levels thereby causing rabbit p19{sup ARF} induction and accumulation of p53 without affecting cellular proliferation. Both CRPV E6 proteins failed to degrade rabbit p53 in vitro or to bind E6AP; however, p53 was still inducible by mitomycin C. In summary, CRPV E7 immortalizes rabbit keratinocytes in a species-specific manner and E6 contributes to immortalization without directly affecting p53.

Ganzenmueller, Tina; Matthaei, Markus; Muench, Peter; Scheible, Michael; Iftner, Angelika; Hiller, Thomas; Leiprecht, Natalie; Probst, Sonja; Stubenrauch, Frank [Sektion Experimentelle Virologie, Universitaetsklinikum Tuebingen, 72076 Tuebingen (Germany); Iftner, Thomas [Sektion Experimentelle Virologie, Universitaetsklinikum Tuebingen, 72076 Tuebingen (Germany)], E-mail: thomas.iftner@med.uni-tuebingen.de

2008-03-15

193

Proteomic Investigation in A549 Lung Cell Line Stably Infected by HPV16E6\\/E7 Oncogenes  

Microsoft Academic Search

Background: Data have accumulated implicating the involvement of oncogenic human papillomaviruses (HPVs) in bronchial carcinogenesis. We recently described the presence of oncogenic HPV transcripts in non-small cell lung cancers. Objective: To investigate the role of oncogenic HPVs in lung carcinogenesis. Material and Methods: The lung cell line A549 stably infected with HPV16E6, HPV16E7 and HPVE6\\/E7 constructs was used to investigate

Marco Ciotti; Valeria Marzano; Laura Giuliani; Marzia Nuccetelli; Simona D’Aguanno; Barbara Azzimonti; Sergio Bernardini; Carlo Federico Perno; Andrea Urbani; Cartesio Favalli; Giorgio Federici

2009-01-01

194

Identification of RNA Aptamers that Internalize into HPV-16 E6/E7 Transformed Tonsillar Epithelial Cells  

PubMed Central

Human papillomavirus type 16 (HPV-16) associated oropharyngeal cancers are on a significant increase and better therapeutic strategies are needed. The HPV-16 oncogenes E6 and E7 are expressed in HPV-associated cancers and are able to transform human tonsillar epithelial cells (HTECs). We used cell-SELEX (Systematic Evolution of Ligands by Exponential Enrichment) to select for RNA aptamers that entered into HPV-16 E6/E7-HTECs. After 12 rounds of cell-SELEX, a pool of aptamers was obtained that had significantly greater internalization capacity (~5-fold) into E6/E7-HTECs as compared to primary HTECs or fibroblasts. Analysis of individual aptamers from the pool indicated variable internalization into E6/E7-HTECs (1 to 8-fold as compared to a negative control). Most of the individual aptamers internalized into E6/E7 and primary HTECs with similar efficiency, while one aptamer exhibited ~3-fold better internalization into E6/E7-HTECs. Aptamers that internalize into cells may be useful for delivering therapeutic agents to HPV-16 associated malignancies. PMID:24074596

Gourronc, Francoise A.; Rockey, William M.; Thiel, William H.; Giangrande, Paloma H.; Klingelhutz, Aloysius J.

2013-01-01

195

Identification of T- and B-cell epitopes of the E7 protein of human papillomavirus type 16.  

PubMed Central

There is strong evidence implicating human papillomavirus type 16 (HPV16) in the genesis of human genital cancer. Viral DNA has been identified in invasive carcinoma of the uterine cervix and in cell lines derived from cervical carcinomas. These sequences are actively transcribed, and translation products corresponding to the early (E)-region genes have been identified. The most abundant viral protein is the E7 protein, which has been shown to possess transforming activity for both established and primary cells. In addition, it has been shown to bind to a cellular tumor suppressor, the retinoblastoma gene product (pRb-105). In view of these properties, we have undertaken the immunological analysis of this protein and have identified four T-cell epitopes and three B-cell epitopes by using a series of overlapping peptides spanning the entire HPV16 E7 sequence. Two of the B-cell epitopes were recognized by antisera from mice with three different murine (H-2) haplotypes (k, d, and s) immunized with two different E7 fusion proteins and from Fischer rats seeded with baby rat kidney cells transformed by HPV16 E7 and ras. A third B-cell epitope was recognized by antisera from CBA mice seeded with HPV16 E7-expressing L cells. Two regions of the protein contain common B- and T-cell epitopes, one of which appears to be particularly immunodominant. Images PMID:1714516

Comerford, S A; McCance, D J; Dougan, G; Tite, J P

1991-01-01

196

Cassini Plasma Spectrometer Ion Observations Close to Enceladus: E3, E5 and E7  

NASA Astrophysics Data System (ADS)

The Cassini Plasma Spectrometer (CAPS) detected freshly-produced water-group ions (O+, OH+, H2O+, H3O+) and heavier water dimer ions (HxO2)+ very close to Enceladus where the plasma begins to emerge from the south polar plume (1). The data were obtained during two close (52 and 25 km) flybys of Enceladus in 2008 (E3 and E5) and are consistent with measurements from the Cassini Ion Neutral Mass Spectrometer (INMS). The ions are observed in CAPS detectors looking in the Cassini ram direction close to the ram kinetic energy, indicative of a nearly stagnant plasma flow in the plume. North of Enceladus the plasma slowing commences about 4 to 6 Enceladus radii away, while south of Enceladus signatures of the plasma interaction with the plume are detected 22 Enceladus radii away. Here we review and contrast these observations including the E7 flyby (anticipated Nov. 2, 2009). E7 is planned for a closest approach ~103 km south of Enceladus and CAPS should detect ions at rest with respect to Enceladus and over a broad range of gyrophase angles. Plasma fluid parameters both upstream and downstream of these encounters are extracted from the CAPS data. In addition, we compare the CAPS ion measurements with both fluid and 3D hybrid simulations. The MHD simulations (BATSRUS) are tuned to agree with Cassini Magnetometer (MAG) observations during the encounters then compared with CAPS observations. For example, for the E3 encounter the CAPS/BATSRUS comparison is striking, with features reproduced such as: the overall spatial scale of the interaction, the slowing of the ion flow within the dust plume to less than 5 km/s with respect to Enceladus, the temperature, flow and density signature of the geometric wake, and the flow perturbation along the magnetic field due to wake expansion. For E5, BATSRUS tuned against MAG suggests a 15 km/s bulk plasma flow toward Saturn during the encounter. We search for signatures of this flow in the CAPS ion data. 1.) Tokar,R.L. et al. Geophys. Res. Lett., 36, L13203, doi:10.1029/2009GL038923, 2009.

Tokar, R. L.; Johnson, R. E.; Thomsen, M. F.; Wilson, R. J.; Crary, F. J.; Young, D. T.; Goldstein, R.; Reisenfeld, D. B.; Sittler, E. C.; Coates, A. J.; Paty, C. S.; Jia, Y.; Omidi, N.; Russell, C.

2009-12-01

197

The transcription elongation factor ELL2 is specifically upregulated in HTLV-1-infected T-cells and is dependent on the viral oncoprotein Tax.  

PubMed

The oncoprotein Tax of human T-cell leukemia virus type 1 (HTLV-1) is a potent transactivator of viral and cellular transcription. Here, we identified ELL2 as the sole transcription elongation factor to be specifically upregulated in HTLV-1-/Tax-transformed T-cells. Tax contributes to regulation of ELL2, since transient transfection of Tax increases ELL2 mRNA, Tax transactivates the ELL2 promoter, and repression of Tax results in decrease of ELL2 in transformed T-lymphocytes. However, we also measured upregulation of ELL2 in HTLV-1-transformed cells exhibiting undetectable amounts of Tax, suggesting that ELL2 can still be maintained independent of continuous Tax expression. We further show that Tax and ELL2 synergistically activate the HTLV-1 promoter, indicating that ELL2 cooperates with Tax in viral transactivation. This is supported by our findings that Tax and ELL2 accumulate in nuclear fractions and that they co-precipitate upon co-expression in transiently-transfected cells. Thus, upregulation of ELL2 could contribute to HTLV-1 gene regulation. PMID:25058508

Mann, Melanie C; Strobel, Sarah; Fleckenstein, Bernhard; Kress, Andrea K

2014-09-01

198

The HBx Oncoprotein of Hepatitis B Virus Deregulates the Cell Cycle by Promoting the Intracellular Accumulation and Re-Compartmentalization of the Cellular Deubiquitinase USP37  

PubMed Central

The HBx oncoprotein of hepatitis B Virus has been accredited as one of the protagonists in driving hepatocarcinogenesis. HBx exerts its influence over the cell cycle progression by potentiating the activity of cyclin A/E-CDK2 complex, the Cyclin A partner of which is a well-known target of cellular deubiquitinase USP37. In the present study, we observed the intracellular accumulation of cyclin A and USP37 proteins under the HBx microenvironment. Flow cytometry analysis of the HBx-expressing cells showed deregulation of cell cycle apparently due to the enhanced gene expression and stabilization of USP37 protein and deubiquitination of Cyclin A by USP37. Our co-immunoprecipitation and confocal microscopic studies suggested a direct interaction between USP37 and HBx. This interaction promoted the translocation of USP37 outside the nucleus and prevented its association and ubiquitination by E3 ubiquitin ligases - APC/CDH1 and SCF/?-TrCP. Thus, HBx seems to control the cell cycle progression via the cyclin A-CDK2 complex by regulating the intracellular distribution and stability of deubiquitinase USP37. PMID:25347529

Saxena, Nehul; Kumar, Vijay

2014-01-01

199

The TBC1D15 Oncoprotein Controls Stem Cell Self-Renewal through Destabilization of the Numb-p53 Complex  

PubMed Central

Stem cell populations are maintained through self-renewing divisions in which one daughter cell commits to a specific fate while the other retains the multipotent characteristics of its parent. The p53 tumor suppressor, in conjunction with its interacting partner protein Numb, preserves this asymmetry and functions as a vital barrier against the unchecked expansion of tumor stem cell pools; however, little is known about the biological control of the Numb-p53 interaction. We show here that Numb and p53 are the constituents of a high molecular mass complex, which is disintegrated upon activation of aPKC?, a Numb kinase. Using large-scale affinity purification and tandem mass spectrometry, we identify TBC1D15 as a Numb-associated protein and demonstrate that its amino-terminal domain disengages p53 from Numb, triggering p53 proteolysis and promoting self-renewal and pluripotency. Cellular levels of TBC1D15 are diminished upon acute nutrient deprivation through autophagy-mediated degradation, indicating that TBC1D15 serves as a conduit through which cellular metabolic status is linked to self-renewal. The profound deregulation of TBC1D15 expression exhibited in a diverse array of patient tumors underscores its proposed function as an oncoprotein. PMID:23468968

Feldman, Douglas E.; Chen, Chialin; Punj, Vasu; Machida, Keigo

2013-01-01

200

Why there are no elliptical galaxies more flattened than E7: thirty years later  

E-print Network

Elliptical galaxies are modelled as homeoidally striated Jacobi ellipsoids where the peculiar velocity distribution is anisotropic, or equivalently as their adjoints configurations i.e. classical Jacobi ellipsoids of equal mass and axes, in real or imaginary rotation. Reasons for the coincidence of bifurcation points from axisymmetric to triaxial configurations in both the sequences, contrary to earlier findings, are presented and discussed. The effect of centrifugal support at the ends of the major equatorial axis, is briefly outlined. The existence of a lower limit to the flattening of elliptical galaxies is investigated in dealing with a number of limiting situations. More specifically, (i) elliptical galaxies are considered as isolated systems, and an allowed region within Ellipsoidland, related to the occurrence of bifurcation points from ellipsoidal to pear-shaped configurations, is shown to be consistent with observations; (ii) elliptical galaxies are considered as embedded within dark matter haloes and, under reasonable assumptions, it is shown that tidal effects from hosting haloes have little influence on the above mentioned results; (iii) dark matter haloes and embedded elliptical galaxies, idealized as a single homeoidally striated Jacobi ellipsoid, are considered in connection with the cosmological transition from expansion to relaxation, by generalizing an earlier model, and the existence of a lower limit to the flattening of relaxed (oblate-like) configurations, is established. On the other hand, no lower limit is found to the elongation of relaxed (prolate-like) configurations, and the observed lack of elliptical galaxies more elongated than E7 needs a different physical interpretation, such as the fully investigated bending instabilities.

R. Caimmi

2007-04-24

201

Multiple Aromatic Side Chains within a Disordered Structure Are Critical for Transcription and Transforming Activity of EWS Family Oncoproteins  

Microsoft Academic Search

Chromosomal translocations involving the N-terminal ?250 residues of the Ewings sarcoma (EWS) oncogene produce a group of EWS fusion proteins (EFPs) that cause several distinct human cancers. EFPs are potent transcriptional activators and interact with other proteins required for mRNA biogenesis, indicating that EFPs induce tumorigenesis by perturbing gene expression. Although EFPs were discovered more than a decade ago, molecular

King Pan Ng; Gary Potikyan; Rupert O. V. Savene; Christopher T. Denny; Vladimir N. Uversky; Kevin A. W. Lee

2007-01-01

202

Bovine Papillomavirus Type 2 (BPV-2) E5 Oncoprotein Binds to the Subunit D of the V1-ATPase Proton Pump in Naturally Occurring Urothelial Tumors of the Urinary Bladder of Cattle  

PubMed Central

Background Active infection by bovine papillomavirus type 2 (BPV-2) was documented for fifteen urinary bladder tumors in cattle. Two were diagnosed as papillary urothelial neoplasm of low malignant potential (PUNLMP), nine as papillary and four as invasive urothelial cancers. Methods and Findings In all cancer samples, PCR analysis revealed a BPV-2-specific 503 bp DNA fragment. E5 protein, the major oncoprotein of the virus, was shown both by immunoprecipitation and immunohistochemical analysis. E5 was found to bind to the activated (phosphorylated) form of the platelet derived growth factor ? receptor. PDGF?R immunoprecipitation from bladder tumor samples and from normal bladder tissue used as control revealed a protein band which was present in the pull-down from bladder cancer samples only. The protein was identified with mass spectrometry as “V1-ATPase subunit D”, a component of the central stalk of the V1-ATPase vacuolar pump. The subunit D was confirmed in this complex by coimmunoprecipitation investigations and it was found to colocalize with the receptor. The subunit D was also shown to be overexpressed by Western blot, RT-PCR and immunofluorescence analyses. Immunoprecipitation and immunofluorescence also revealed that E5 oncoprotein was bound to the subunit D. Conclusion For the first time, a tri-component complex composed of E5/PDGF?R/subunit D has been documented in vivo. Previous in vitro studies have shown that the BPV-2 E5 oncoprotein binds to the proteolipid c ring of the V0-ATPase sector. We suggest that the E5/PDGF?R/subunit D complex may perturb proteostasis, organelle and cytosol homeostasis, which can result in altered protein degradation and in autophagic responses. PMID:24586417

Roperto, Sante; Russo, Valeria; Borzacchiello, Giuseppe; Urraro, Chiara; Lucà, Roberta; Esposito, Iolanda; Riccardi, Marita Georgia; Raso, Cinzia; Gaspari, Marco; Ceccarelli, Dora Maria; Galasso, Rocco; Roperto, Franco

2014-01-01

203

A functional interaction of E7 with B-Myb-MuvB complex promotes acute cooperative transcriptional activation of both S- and M-phase genes. (129 c).  

PubMed

High-risk human papillomaviruses are causative agents of cervical cancer. Viral protein E7 is required to establish and maintain the pro-oncogenic phenotype in infected cells, but the molecular mechanisms by which E7 promotes carcinogenesis are only partially understood. Our transcriptome analyses in primary human fibroblasts transduced with the viral protein revealed that E7 activates a group of mitotic genes via the activator B-Myb-MuvB complex. We show that E7 interacts with the B-Myb, FoxM1 and LIN9 components of this activator complex, leading to cooperative transcriptional activation of mitotic genes in primary cells and E7 recruitment to the corresponding promoters. E7 interaction with LIN9 and FoxM1 depended on the LXCXE motif, which is also required for pocket protein interaction and degradation. Using E7 mutants for the degradation of pocket proteins but intact for the LXCXE motif, we demonstrate that E7 functional interaction with the B-Myb-MuvB complex and pocket protein degradation are two discrete functions of the viral protein that cooperate to promote acute transcriptional activation of mitotic genes. Transcriptional level of E7 in patient's cervical lesions at different stages of progression was shown to correlate with those of B-Myb and FoxM1 as well as other mitotic gene transcripts, thereby linking E7 with cellular proliferation and progression in cervical cancer in vivo. E7 thus can directly activate the transcriptional levels of cell cycle genes independently of pocket protein stability. PMID:24141769

Pang, C L; Toh, S Y; He, P; Teissier, S; Ben Khalifa, Y; Xue, Y; Thierry, F

2014-07-31

204

ERP, a new member of the ets transcription factor/oncoprotein family: cloning, characterization, and differential expression during B-lymphocyte development.  

PubMed Central

The ets gene family encodes a group of proteins which function as transcription factors under physiological conditions and, if aberrantly expressed, can cause cellular transformation. We have recently identified two regulatory elements in the murine immunoglobulin heavy-chain (IgH) enhancer, pi and microB, which exhibit striking similarity to binding sites for ets-related proteins. To identify ets-related transcriptional regulators expressed in pre-B lymphocytes that may interact with either the pi or the microB site, we have used a PCR approach with degenerate oligonucleotides encoding conserved sequences in all members of the ets family. We have cloned the gene for a new ets-related transcription factor, ERP (ets-related protein), from the murine pre-B cell line BASC 6C2 and from mouse lung tissue. The ERP protein contains a region of high homology with the ETS DNA-binding domain common to all members of the ets transcription factor/oncoprotein family. Three additional smaller regions show homology to the ELK-1 and SAP-1 genes, a subgroup of the ets gene family that interacts with the serum response factor. Full-length ERP expresses only negligible DNA-binding activity by itself. Removal of the carboxy terminus enables ERP to interact with a variety of ets-binding sites including the E74 site, the IgH enhancer pi site, and the lck promoter ets site, suggesting a carboxy-terminal negative regulatory domain. At least three ERP-related transcripts are expressed in a variety of tissues. However, within the B-cell lineage, ERP is highly expressed primarily at early stages of B-lymphocyte development, and expression declines drastically upon B-cell maturation, correlating with the enhancer activity of the IgH pi site. These data suggest that ERP might play a role in B-cell development and in IgH gene regulation. Images PMID:7909357

Lopez, M; Oettgen, P; Akbarali, Y; Dendorfer, U; Libermann, T A

1994-01-01

205

Protein Tyrosine Phosphatase 1B Antagonizes Signalling by Oncoprotein Tyrosine Kinase p210 bcr-abl In Vivo  

PubMed Central

The p210 bcr-abl protein tyrosine kinase (PTK) appears to be directly responsible for the initial manifestations of chronic myelogenous leukemia (CML). In contrast to the extensive characterization of the PTK and its effects on cell function, relatively little is known about the nature of the protein tyrosine phosphatases (PTPs) that may modulate p210 bcr-abl-induced signalling. In this study, we have demonstrated that expression of PTP1B is enhanced specifically in various cells expressing p210 bcr-abl, including a cell line derived from a patient with CML. This effect on expression of PTP1B required the kinase activity of p210 bcr-abl and occurred rapidly, concomitant with maximal activation of a temperature-sensitive mutant of the PTK. The effect is apparently specific for PTP1B since, among several PTPs tested, we detected no change in the levels of TCPTP, the closest relative of PTP1B. We have developed a strategy for identification of physiological substrates of individual PTPs which utilizes substrate-trapping mutant forms of the enzymes that retain the ability to bind to substrate but fail to catalyze efficient dephosphorylation. We have observed association between a substrate-trapping mutant of PTP1B (PTP1B-D181A) and p210 bcr-abl, but not v-Abl, in a cellular context. Consistent with the trapping data, we observed dephosphorylation of p210 bcr-abl, but not v-Abl, by PTP1B in vivo. We have demonstrated that PTP1B inhibited binding of the adapter protein Grb2 to p210 bcr-abl and suppressed p210 bcr-abl-induced transcriptional activation that is dependent on Ras. These results illustrate selectivity in the effects of PTPs in a cellular context and suggest that PTP1B may function as a specific, negative regulator of p210 bcr-abl signalling in vivo. PMID:9566916

LaMontagne, Kenneth R.; Flint, Andrew J.; Franza, B. Robert; Pendergast, Ann Marie; Tonks, Nicholas K.

1998-01-01

206

Interaction of human papillomavirus 8 regulatory proteins E2, E6 and E7 with components of the TFIID complex.  

PubMed

Human papillomavirus 8 (HPV8) is one of the oncogenic HPV types specifically associated with skin cancers of epidermodysplasia verruciformis patients. The early gene products of this virus exert functions in transformation (E2, E6, E7), replication (E1, E2) and in the control of viral transcription (E2, E7). Many viral and cellular transactivators of transcription have been shown to interact selectively and directly with a number of TATA-box-binding protein (TBP)-associated factors (TAFIIs), which then play a role as coactivators. Using glutathione-S-transferase (GST) pull-down experiments, we tested in vitro interactions between GST-HPV8-E1, -E2, -E6 and -E7 and 7 in-vitro-translated TAFIIs in the human (h) system (hTAFII18, hTAFII20, hTAFII28, hTAFII30, hTAFII55, hTAFII100, hTAFIIDeltaN135) or TBP. We could show that GST-HPV8-E2 interacts directly at least with hTAFII55 and TBP. Deletion analysis indicated that a domain overlapping with the C-terminal moiety of HPV8-E2 is required for binding to TBP, whereas determinants for interactions with hTAFII55 are in the central and C-terminal part of the E2 protein. In similar binding studies, GST-HPV8-E6 interacted with hTAFII28, hTAFIIDeltaN135 and TBP, and more weakly with hTAFII20, whereas GST- HPV8-E7 bound to hTAFII20, hTAFII28, hTAFII55, hTAFIIDeltaN135 and TBP. Deletion analysis revealed that the C-terminal part of HPV8-E7 is required for the interaction with these hTAFIIs. In contrast, no interactions were observed between GST-HPV8-E1 and in-vitro-translated hTAFIIs. PMID:9820841

Enzenauer, C; Mengus, G; Lavigne, A; Davidson, I; Pfister, H; May, M

1998-01-01

207

Heterodimers of the SnoN and Ski oncoproteins form preferentially over homodimers and are more potent transforming agents.  

PubMed

sno is a member of the ski oncogene family and shares ski 's ability to transform avian fibroblasts and induce muscle differentiation. Ski and SnoN are transcription factors that form both homodimers and heterodimers. They recognize a specific DNA binding site (GTCTAGAC) through which they repress transcription. Efficient homodimerization of Ski, mediated by a bipartite C-terminal domain consisting of five tandem repeats (TR) and a leucine zipper (LZ), correlates with efficient DNA binding and cellular transformation. The present study assesses the role of SnoN homodimerization and SnoN:Ski heterodimerization in the activities of these proteins. Unlike Ski, efficient homodimerization by SnoN is shown to require an upstream region of the protein in addition to the TR/LZ domain. Deletion of the TR/LZ from SnoN decreases its activity in transcriptional repression and cellular transformation. When co-expressed in vitro, c-Ski and SnoN preferentially form heterodimers. In vivo, they form heterodimers that bind the GTCTAGAC element. Tethered Ski:Sno hetero-dimers that lack TR/LZ domains are more active than either their monomeric counterparts, tethered Ski:Ski homodimers or full-length SnoN and c-Ski. This work demonstrates, for the first time, the differences between dimer formation by Ski and SnoN and underscores the importance of dimerization in their activity. PMID:9927733

Cohen, S B; Zheng, G; Heyman, H C; Stavnezer, E

1999-02-15

208

The PIM family of oncoproteins: Small kinases with huge implications in myeloid leukemogenesis and as therapeutic targets  

PubMed Central

PIM kinases are a family of serine/threonine kinases involved in cell survival and proliferation. There is significant structural similarity between the three PIM kinases (PIM1, PIM2 and PIM3) and few amino acid differences. Although, several studies have specifically monitored the role of PIM1 in tumorigenesis, much less is known about PIM2 and PIM3. Therefore, in this study we have used in vitro cell culture models and in vivo bone marrow infection/transplantation to assess the comparative signaling and oncogenic potential of each of the three PIM kinases. All three PIM kinases were able to protect FL5.12 cells from IL-3 withdrawal induced death. Interestingly, the downstream signaling cascades were indistinguishable between the three kinases. Transplantation of murine bone marrow co-expressing MYC and PIM1, PIM2 or PIM3 caused rapid and uniformly lethal myeloid leukemia. De-induction of MYC 18 days following transplantation significantly increased the survival of mice, even with continual expression of PIM kinases. Alternatively, mice treated at the pre-leukemic stage with a PIM kinase inhibitor increased the lifespan of the mice, even with continual expression of the MYC transgene. These data demonstrate the role of PIM kinases in driving myeloid leukemia, and as candidate molecules for therapy against human malignancies. PMID:25238262

Shah, Parag P.; Mims, Alice S.; Lockwood, William W.; Kraft, Andrew S.; Beverly, Levi J.

2014-01-01

209

Multiple aromatic side chains within a disordered structure are critical for transcription and transforming activity of EWS family oncoproteins.  

PubMed

Chromosomal translocations involving the N-terminal approximately 250 residues of the Ewings sarcoma (EWS) oncogene produce a group of EWS fusion proteins (EFPs) that cause several distinct human cancers. EFPs are potent transcriptional activators and interact with other proteins required for mRNA biogenesis, indicating that EFPs induce tumorigenesis by perturbing gene expression. Although EFPs were discovered more than a decade ago, molecular analysis has been greatly hindered by the repetitive EWS activation domain (EAD) structure, containing multiple degenerate hexapeptide repeats (consensus SYGQQS) with a conserved tyrosine residue. By exploiting total gene synthesis, we have been able to systematically mutagenize the EAD and determine the effect on transcriptional activation by EWS/ATF1 and cellular transformation by EWS/Fli1. In both assays, we find the following requirements for EAD function. First, multiple tyrosine residues are essential. Second, phenylalanine can effectively substitute for tyrosine, showing that an aromatic ring can confer EAD function in the absence of tyrosine phosphorylation. Third, there is little requirement for specific peptide sequences and, thus, overall sequence composition (and not the degenerate hexapeptide repeat) confers EAD activity. Consistent with the above findings, we also report that the EAD is intrinsically disordered. However, a sensitive computational predictor of natural protein disorder (PONDR VL3) identifies potential molecular recognition features that are tyrosine-dependent and that correlate well with EAD function. In summary we have uncovered several molecular features of the EAD that will impact future studies of the broader EFP family and molecular recognition by complex intrinsically disordered proteins. PMID:17202261

Ng, King Pan; Potikyan, Gary; Savene, Rupert O V; Denny, Christopher T; Uversky, Vladimir N; Lee, Kevin A W

2007-01-01

210

Transgenic expression of Helicobacter pylori CagA induces gastrointestinal and hematopoietic neoplasms in mouse.  

PubMed

Infection with cagA-positive Helicobacter pylori is associated with gastric adenocarcinoma and gastric mucosa-associated lymphoid tissue (MALT) lymphoma of B cell origin. The cagA-encoded CagA protein is delivered into gastric epithelial cells via the bacterial type IV secretion system and, upon tyrosine phosphorylation by Src family kinases, specifically binds to and aberrantly activates SHP-2 tyrosine phosphatase, a bona fide oncoprotein in human malignancies. CagA also elicits junctional and polarity defects in epithelial cells by interacting with and inhibiting partitioning-defective 1 (PAR1)/microtubule affinity-regulating kinase (MARK) independently of CagA tyrosine phosphorylation. Despite these CagA activities that contribute to neoplastic transformation, a causal link between CagA and in vivo oncogenesis remains unknown. Here, we generated transgenic mice expressing wild-type or phosphorylation-resistant CagA throughout the body or predominantly in the stomach. Wild-type CagA transgenic mice showed gastric epithelial hyperplasia and some of the mice developed gastric polyps and adenocarcinomas of the stomach and small intestine. Systemic expression of wild-type CagA further induced leukocytosis with IL-3/GM-CSF hypersensitivity and some mice developed myeloid leukemias and B cell lymphomas, the hematological malignancies also caused by gain-of-function SHP-2 mutations. Such pathological abnormalities were not observed in transgenic mice expressing phosphorylation-resistant CagA. These results provide first direct evidence for the role of CagA as a bacterium-derived oncoprotein (bacterial oncoprotein) that acts in mammals and further indicate the importance of CagA tyrosine phosphorylation, which enables CagA to deregulate SHP-2, in the development of H. pylori-associated neoplasms. PMID:18192401

Ohnishi, Naomi; Yuasa, Hitomi; Tanaka, Shinya; Sawa, Hirofumi; Miura, Motohiro; Matsui, Atsushi; Higashi, Hideaki; Musashi, Manabu; Iwabuchi, Kazuya; Suzuki, Misao; Yamada, Gen; Azuma, Takeshi; Hatakeyama, Masanori

2008-01-22

211

[Construction and eukaryotic expression of PVAX1-hPV58mE6E7fcGB composite gene vaccine].  

PubMed

To construct and express a composite gene vaccine for human papillomavirus 58(HPV58)-associated cervical cancer, we inserted HPV58mE6E7 fusion gene into pCI-Fc-GPI eukaryotic expression vector, constructing a recombinant plasmid named pCI-sig-HPV58mE6E7-Fc-GPI. Then we further inserted fragment of sig-HPV58mE6E7Fc-GPI into the novel vaccine vector PVAX1-IRES-GM/B7, constructing PVAX1-HPV58mE6E7FcGB composite gene vaccine. PVAX1-HPV58mE6E7FcGB vaccine was successfully constructed and identified by restriction endonuclease and sequencing analysis. Eukaryotic expression of fusion antigen sig-HPV58mE6E7-Fc-GPI and molecular ad-juvant GM-CSF and B7. 1 were proved to be realized at the same time by flow cytometry and immunofluorescence. So PVAX1-HPV58mE6E7FcGB can be taken as a candidate of therapeutic vaccine for HPV58-associated tumors and their precancerous transformations. PMID:24459978

Wang, He; Yu, Jiyun; Li, Li

2013-10-01

212

Optimization of supercoiled HPV-16 E6/E7 plasmid DNA purification with arginine monolith using design of experiments.  

PubMed

The progress of DNA vaccines is dependent on the development of suitable chromatographic procedures to successfully purify genetic vectors, such as plasmid DNA. Human Papillomavirus is associated with the development of tumours due to the oncogenic power of E6 and E7 proteins, produced by this virus. The supercoiled HPV-16 E6/E7 plasmid-based vaccine was recently purified with the arginine monolith, with 100% of purity, but only 39% of recovery was achieved. Therefore, the present study describes the application of experimental design tools, a newly explored methodology in preparative chromatography, in order to improve the supercoiled plasmid DNA recovery with the arginine monolith, maintaining the high purity degree. In addition, the importance and influence of pH in the pDNA retention to the arginine ligand was also demonstrated. The Composite Central Face design was validated and the recovery of the target molecule was successfully improved from 39% to 83.5%, with an outstanding increase of more than double, while maintaining 100% of purity. PMID:25544011

Almeida, A M; Queiroz, J A; Sousa, F; Sousa, A

2015-01-26

213

Kinetic screening of antibody-Im7 conjugates by capture on a colicin E7 DNase domain using optical biosensors.  

PubMed

Antibody generation by phage display and related in vitro display technologies routinely yields large panels of clones detected in primary end-point screenings such as enzyme-linked immunosorbent assay (ELISA). However, for the development of clinical lead candidates, rapid determination of secondary characteristics such as kinetics and thermodynamics is of nearly equal importance. Surface plasmon resonance-based biosensors are ideal tools for carrying out such high-throughput secondary screenings, allowing preliminary but confident ranking and identification of lead clones. A key feature of these assays is the stable and reversible capture of antibody fragments from crude samples leading to high-resolution kinetic analysis of library outputs. Here we exploit the high-affinity interaction between the naturally occurring nuclease domain of E. coli colicin E7 (DNaseE7) and its cognate partner, the immunity protein 7 (Im7), to develop a ligand capture system suitable for accurate kinetic ranking of library clones. We demonstrate generic applicability for a range of antibody formats: scFv antibodies, diabodies, antigen binding fragments (Fabs), and shark V(NAR) single domain antibodies. The system is adaptable and reproducible, with comparable results achieved for both the Biacore T100 and ProteOn XPR36 array biosensors. PMID:19073134

Hosse, Ralf J; Tay, Leigh; Hattarki, Meghan K; Pontes-Braz, Luisa; Pearce, Lesley A; Nuttall, Stewart D; Dolezal, Olan

2009-02-15

214

Prevalence of HPV and variation of HPV 16/HPV 18 E6/E7 genes in cervical cancer in women in South West China.  

PubMed

Genetic variations of High-Risk HPV E6/E7 may be associated with the development of cervical cancer in specific geographic regions. Few data have been reported about the HPV prevalence and E6/E7 variants among cervical cancer patients in Southwest China. This study was designed to investigate the prevalence of HPV and E6/E7 variants of most prevalent HPV among cervical cancer patients in Southwest China. After genotyping, E6/E7 genes of most prevalent HR HPV samples were sequenced and analyzed. Phylogenetic trees were then constructed, followed by an analysis of the diversity of secondary structure and selection pressures. HPV 16 (73.8%) and HPV 18 (16.4%) are the most prevalent infection types among cervical cancer patients, followed by HPV 58, HPV 56 and HPV 59, which is different from the high HPV 58 infection rate of outpatients in this region. Eighteen single nucleotide changes were observed in HPV 16 E6 with 13/18 non-synonymous mutations (5 in beta sheet and 2 in alpha helix). Ten single nucleotide changes were identified among HPV 16 E7 with 3/10 non-synonymous mutations. Three single nucleotide changes were observed in HPV 18 E6 with one non-synonymous mutation, and only one synonymous mutation was identified in HPV 18 E7. HPV 16 E6-D25E, E7-N29S and E7-T846C (S95S) exhibited a prevalent linkage mutation. The phylogenetic tree demonstrates that European and Asian lineages were the main patterns. This study may help understand the intrinsic geographical relatedness and oncogenic potential of HR HPV and contributes further to research of diagnostic, therapeutic and therapeutic vaccine strategy. PMID:25111286

Yang, Lijuan; Yang, Hongying; Wu, Kun; Shi, Xinan; Ma, Shaohui; Sun, Qiangming

2014-11-01

215

Diagnosis of 25 genotypes of human papillomaviruses for their physical statuses in cervical precancerous/cancerous lesions: a comparison of E2/E6E7 ratio-based vs. multiple E1-L1/E6E7 ratio-based detection techniques.  

PubMed

BackgroundCervical lesions caused by integrated human papillomavirus (HPV) infection are highly dangerous because they can quickly develop into invasive cancers. However, clinicians are currently hampered by the lack of a quick, convenient and precise technique to detect integrated/mixed infections of various genotypes of HPVs in the cervix. This study aimed to develop a practical tool to determine the physical status of different HPVs and evaluate its clinical significance.MethodsThe target population comprised 1162 women with an HPV infection history of¿>¿six months and an abnormal cervical cytological finding. The multiple E1-L1/E6E7 ratio analysis, a novel technique, was developed based on determining the ratios of E1/E6E7, E2/E6E7, E4E5/E6E7, L2/E6E7 and L1/E6E7 within the viral genome. Any imbalanced ratios indicate integration. Its diagnostic and predictive performances were compared with those of E2/E6E7 ratio analysis. The detection accuracy of both techniques was evaluated using the gold-standard technique ¿detection of integrated papillomavirus sequences¿ (DIPS). To realize a multigenotypic detection goal, a primer and probe library was established.ResultsThe integration rate of a particular genotype of HPV was correlated with its tumorigenic potential and women with higher lesion grades often carried lower viral loads. The E1-L1/E6E7 ratio analysis achieved 92.7% sensitivity and 99.0% specificity in detecting HPV integration, while the E2/E6E7 ratio analysis showed a much lower sensitivity (75.6%) and a similar specificity (99.3%). Interference due to episomal copies was observed in both techniques, leading to false-negative results. However, some positive results of E1-L1/E6E7 ratio analysis were missed by DIPS due to its stochastic detection nature. The E1-L1/E6E7 ratio analysis is more efficient than E2/E6E7 ratio analysis and DIPS in predicting precancerous/cancerous lesions, in which both positive predictive values (36.7%-82.3%) and negative predictive values (75.9%-100%) were highest (based on the results of three rounds of biopsies).ConclusionsThe multiple E1-L1/E6E7 ratio analysis is more sensitive and predictive than E2/E6E7 ratio analysis as a triage test for detecting HPV integration. It can effectively narrow the range of candidates for colposcopic examination and cervical biopsy, thereby lowering the expense of cervical cancer prevention. PMID:25269554

Zhang, Rong; He, Yi-Feng; Chen, Mo; Chen, Chun-Mei; Zhu, Qiu-Jing; Lu, Huan; Wei, Zhen-Hong; Li, Fang; Zhang, Xiao-Xin; Xu, Cong-Jian; Yu, Long

2014-10-01

216

Clinical Performance of the PreTect HPV-Proofer E6/E7 mRNA Assay in Comparison with That of the Hybrid Capture 2 Test for Identification of Women at Risk of Cervical Cancer?  

PubMed Central

Human papillomavirus (HPV) DNA testing has a higher clinical sensitivity than cytology for the detection of high-grade cervical intraepithelial neoplasia or worse (CIN 2+). However, an improvement in specificity would be desirable. As malignant transformation is induced by HPV E6/E7 oncogenes, detection of E6/E7 oncogene activity may improve specificity and be more predictive of cervical cancer risk. The PreTect HPV-Proofer assay (Proofer; Norchip) detects E6/E7 mRNA transcripts from HPV types 16, 18, 31, 33, and 45 with simultaneous genotype-specific identification. The clinical performance of this assay was assessed in a cross-sectional study of women referred for colposcopy in comparison with the Hybrid Capture 2 (HC2; Qiagen) test, which detects DNA of 13 high-risk oncogenic HPV types collectively. Cervical specimens were collected in PreservCyt, and cytology was performed using the ThinPrep method (Hologic). The samples were processed for HPV detection with Proofer and HC2 and genotyping with the Linear Array method (Roche Molecular Systems). Histology-confirmed CIN 2+ served as the disease endpoint to assess the clinical performance of the tests. A total of 1,551 women were studied, and of these, 402 (25.9%) were diagnosed with CIN 2+ on histology. The Proofer assay showed a sensitivity of 78.1% (95% confidence interval [CI], 74.1 to 82.1) versus 95.8% (95% CI, 93.8 to 97.8) for HC2 (P < 0.05) and a specificity of 75.5% (95% CI, 73.0 to 78.0) versus 39.6% (95% CI, 36.8 to 42.4), respectively (P < 0.05). The lower sensitivity and higher specificity of Proofer for detection of CIN 2+ can be attributed to the fact that this test detects the expression of E6/E7 genes beyond a threshold from a limited number of oncogenic HPV types. In conclusion, Proofer is more specific than HC2 in identifying women with CIN 2+ but has a lower sensitivity. PMID:20573862

Ratnam, Samuel; Coutlee, Francois; Fontaine, Dan; Bentley, James; Escott, Nicholas; Ghatage, Prafull; Gadag, Veeresh; Holloway, Glen; Bartellas, Elias; Kum, Nick; Giede, Christopher; Lear, Adrian

2010-01-01

217

Oncoprotein protein kinase antibody kit  

DOEpatents

An isolated polypeptide (JNK) characterized by having a molecular weight of 46 kD as determined by reducing SDS-PAGE, having serine and threonine kinase activity, phosphorylating the c-Jun N-terminal activation domain and polynucleotide sequences and method of detection of JNK are provided herein. JNK phosphorylates c-Jun N-terminal activation domain which affects gene expression from AP-1 sites.

Karin, Michael (San Diego, CA); Hibi, Masahiko (San Diego, CA); Lin, Anning (La Jolla, CA)

2008-12-23

218

Cataracts in transgenic mice caused by a human papillomavirus type 18 E7 oncogene driven by KRT1-14  

PubMed Central

Human papillomavirus type 18 (HPV18) is a common cause of cervical cancer. To create a mouse model for this common neoplastic disease we used a human keratin 14 promoter to drive the HPV18 E7 oncogene to create transgenic mice. No mice up to a year of age developed cervical cancer. However, all transgenic mice and none of the controls developed progressive bilateral cortical cataracts. By 6 months of age the cortex liquefied leaving the lens nucleus. Proliferation of lens epithelium formed multifocal nodules and free floating lens epithelial cells within the liquefied cortex. These cells were hyperplastic not neoplastic. Other HPV transgenic stocks develop cataracts suggesting this virus may have a broad cellular tropism. PMID:18723014

Ghim, Shinje; Jenson, A. Bennett; Bubier, Jason A.; Silva, Kathleen A.; Smith, Richard S.; Sundberg, John P.

2008-01-01

219

Human Papillomavirus 16 E6 Contributes HIF-1? Induced Warburg Effect by Attenuating the VHL-HIF-1? Interaction  

PubMed Central

Cervical cancer is still one of the leading causes of cancer deaths in women worldwide, especially in the developing countries. It is a major metabolic character of cancer cells to consume large quantities of glucose and derive more energy by glycolysis even in the presence of adequate oxygen, which is called Warburg effect that can be exaggerated by hypoxia. The high risk subtype HPV16 early oncoprotein E6 contributes host cell immortalization and transformation through interacting with a number of cellular factors. Hypoxia-inducible factor 1? (HIF-1?), a ubiquitously expressed transcriptional regulator involved in induction of numerous genes associated with angiogenesis and tumor growth, is highly increased by HPV E6. HIF-1? is a best-known target of the von Hippel-Lindau tumor suppressor (VHL) as an E3 ligase for degradation. In the present work, we found that HPV16 E6 promotes hypoxia induced Warburg effect through hindering the association of HIF-1? and VHL. This disassociation attenuates VHL-mediated HIF-1? ubiquitination and causes HIF-1? accumulation. These results suggest that oncoprotein E6 plays a major role in the regulation of Warburg effect and can be a valuable therapeutic target for HPV-related cancer. PMID:24810689

Guo, Yi; Meng, Xiangkai; Ma, Jiaming; Zheng, Yahong; Wang, Qian; Wang, Yanan; Shang, Hong

2014-01-01

220

SIAH1-induced p34SEI-1 polyubiquitination/degradation mediates p53 preferential vitamin C cytotoxicity.  

PubMed

Vitamin C is considered as an important anticancer therapeutic agent although this view is debatable. In this study, we introduce a physiological mechanism demonstrating how vitamin C exerts anticancer activity that induces cell cycle arrest and apoptosis. Our previous and current data reveal that p53 tumor suppressor is the prerequisite factor for stronger anticancer effects of vitamin C. In addition, vitamin C-mediated cancer cell cytotoxicity appears to be achieved at least partly through the downregulation of the p34SEI-1 oncoprotein. Our previous study showed that p34SEI-1 increases the survival of various types of cancer cells by inhibiting their apoptosis. Present data suggest that vitamin C treatment decreases the p34SEI-1 expression at the protein level and therefore alleviates its anti-apoptotic activity. Of note, SIAH1, E3 ubiquitin ligase, appears to be responsible for the p34SEI-1 polyubiquitination and its subsequent degradation, which is dependent on p53. In summary, vitamin C increases cancer cell death by inducing SIAH1-mediated polyubiquitination/degradation of the p34SEI-1 oncoprotein in a p53-dependent manner. PMID:25586269

Lee, Soonduck; Kim, Jinsun; Jung, Samil; Li, Chengping; Yang, Young; Kim, Keun Il; Lim, Jong-Seok; Kim, Yonghwan; Cheon, Choong-Il; Lee, Myeong-Sok

2015-03-01

221

A new insight into the zinc-dependent DNA-cleavage by the colicin E7 nuclease: a crystallographic and computational study.  

PubMed

The nuclease domain of colicin E7 metallonuclease (NColE7) contains its active centre at the C-terminus. The mutant ?N4-NColE7-C* - where the four N-terminal residues including the positively charged K446, R447 and K449 are replaced with eight residues from the GST tag - is catalytically inactive. The crystal structure of this mutant demonstrates that its overall fold is very similar to that of the native NColE7 structure. This implicates the stabilizing effect of the remaining N-terminal sequence on the structure of the C-terminal catalytic site and the essential role of the deleted residues in the mechanism of the catalyzed reaction. Complementary QM/MM calculations on the protein-DNA complexes support the less favourable cleavage by the mutant protein than by NColE7. Furthermore, a water molecule as a possible ligand for the Zn(2+)-ion is proposed to play a role in the catalytic process. These results suggest that the mechanism of the Zn(2+)-containing HNH nucleases needs to be further studied and discussed. PMID:25179124

Czene, Anikó; Tóth, Eszter; Németh, Eszter; Otten, Harm; Poulsen, Jens-Christian N; Christensen, Hans E M; Rulíšek, Lubomír; Nagata, Kyosuke; Larsen, Sine; Gyurcsik, Béla

2014-11-01

222

The bmi-1 oncoprotein is differentially expressed in non-small cell lung cancer and correlates with INK4A-ARF locus expression  

Microsoft Academic Search

Genes of the polycomb group function by silencing homeotic selector genes that regulate embryogenesis. In mice, downregulation of one of the polycomb genes, bmi-1, leads to neurological alterations and severe proliferative defects in lymphoid cells, whilst bmi-1 overexpression, together with upregulation of myc-1, induces lymphoma. An oncogenic function has been further supported in primary fibroblast studies where bmi-1 overexpression induces

S Vonlanthen; J Heighway; H J Altermatt; M Gugger; A Kappeler; M M Borner; M van Lohuizen; D C Betticher

2001-01-01

223

Influence of chromosomal integration on glucocorticoid-regulated transcription of growth-stimulating papillomavirus genes E6 and E7 in cervical carcinoma cells  

SciTech Connect

In most cervical carcinoma cells the E6 and E7 genes of specific human papillomaviruses are transcribed from viral sequences integrated into host cell chromosomes. Glucocorticoids activate the promoter elements of various human papillomaviruses in transient-expression assays. The authors have analyzed the effect of dexamethasone on the transcription rate of human papillomaviruses 18 E6 and E7 genes integrated at different chromosomal sites in four cervical cancer cell lines. Dexamethasone led to an increase in the transcription rate of the integrated E6-E7 sequences in C4-1 and C4-2 cells but led to a decrease in SW 756 cells and did not affect the transcription rate in HeLa cells. It thus appears that dominant regulatory mechanisms presumably depending on the chromosomal integration site are able to override the response of the viral promoter to steroid hormones. The growth rate of all dexamethasone-treated cell lines correlated consistently with the expression of the papillomavirus E6 and E7 genes, supporting their role in the maintenance of the proliferative phenotype of cervical carcinoma cells. Since human papillomaviruses are integrated into the host cell genome at variable, presumably randomly selected chromosomal loci, regulatory mechanisms that influence viral gene expression, and hence cell growth, may differ among cancers of independent clonal origin.

Von Knebel Doeberitz, M.; Bauknecht, T.; Bartsch, D.; Zur Hausen, H. (Inst. fur Virusforshung/ATV, Heidelberg (West Germany))

1991-02-15

224

The BPS spectrum of the 4d {N}=2 SCFT's H 1, H 2, D 4, E 6, E 7, E 8  

NASA Astrophysics Data System (ADS)

Extending results of 1112.3984, we show that all rank 1 {N}=2 SCFT's in the sequence H 1, H 2, D 4 E 6, E 7, E 8 have canonical finite BPS chambers containing precisely 2 h(F) = 12(? - 1) hypermultiplets. The BPS spectrum of the canonical BPS chambers saturates the conformal central charge c, and satisfies some intriguing numerology.

Cecotti, Sergio; Del Zotto, Michele

2013-06-01

225

Successful Rechallenge with Imatinib in a Patient with Chronic Myeloid Leukemia Who Previously Experienced Imatinib Mesylate Induced Pneumonitis  

PubMed Central

Imatinib mesylate is a targeted therapy that acts by inhibiting tyrosine kinase of the bcr-abl fusion oncoprotein, which is specific to chronic myeloid leukemia (CML), and the c-transmembrane receptor, which is specific to gastrointestinal stromal tumors. Interstitial pneumonitis is a rare adverse event of imatinib therapy. It is clinically difficult to distinguish from infectious pneumonia, which can frequently occur due to the underlying disease. The standard treatment for imatinib-induced pneumonitis is to discontinue the medication and optionally administer corticosteroids. However, there are a few cases of successful retrial with imatinib. We describe a case of successful rechallenge of imatinib in a patient with imatinib-induced interstitial pneumonitis and CML without a recurrence of the underlying disease after 3 months of follow-up. PMID:24416057

Go, Seong Woo; Kim, Boo Kyeong; Lee, Sung Hak; Kim, Tae-Jung; Huh, Joo Yeon; Lee, Jong Min; Hah, Jick Hwan; Kim, Dong Whi; Cho, Min Jung; Kim, Tae Wan

2013-01-01

226

HPV16 E2 is an immediate early marker of viral infection, preceding E7 expression in precursor structures of cervical carcinoma.  

PubMed

The viral E2 gene product plays a crucial role in the human papillomavirus (HPV) vegetative cycle by regulating both transcription and replication of the viral genome. E2 is a transcriptional repressor of the E6 and E7 viral oncogenes for HPV types 16 and 18, which are involved in cervical cancers. Using new polyclonal antibodies against the HPV16 E2 protein, we showed that E2 is expressed at various precursor stages of cervical carcinoma by immunohistochemistry on paraffin-embedded clinical samples. E2 was found to be highly expressed in the nuclei and cytoplasm of cells forming the intermediate and upper layers of cervical intraepithelial neoplasia (CIN). We could show that the expressions of E2 and p16(INK4a) (surrogate marker for oncogenic E7 expression) were exclusive in most of the cases, thus implying that E2 is not expressed together with high levels of E7. Moreover, we found that E2 is expressed in a subset of columnar cells adjacent to the CIN. We could show that expression of E2 is topologically distinct from the proliferation markers p63 and Ki67, whereas it coincides with the expression of cytokeratin K13, a marker of squamous cell differentiation. Expression of E2 also topologically coincides with episomal amplification of viral genomes in the upper layers of CIN1. These in vivo data thus validate previous assumptions of the crucial role of E2 in the early steps of HPV infection and of its negative link with expression of the viral E6 and E7 oncogenes. PMID:20530671

Xue, Yuezhen; Bellanger, Sophie; Zhang, Wenying; Lim, Diana; Low, Jeffrey; Lunny, Declan; Thierry, Françoise

2010-07-01

227

Transcription of Human Papillomavirus Type 16 Early Genes in a Cervical Cancer and a Cancer-Derived Cell Line and Identification of the E7 Protein  

Microsoft Academic Search

Human papillomavirus type 16 DNA and RNA were characterized in the cervical cancer-derived CaSki cell line, which contains only integrated DNA, and in a cervical cancer, which contains predominantly plasmid DNA. In both, a major RNA can code for the early open reading frame E7 and a minor one can code for E6. The cervical cancer, but not the CaSki

David Smotkin; Felix O. Wettstein

1986-01-01

228

Behavioral and electrophysiological activity of ( Z,E )-7,9,11-dodecatrienyl formate, a mimic of the major sex pheromone component of carob moth, Ectomyelois ceratoniae  

Microsoft Academic Search

The behavioral and electrophysiological activity of a mimic [(Z,E)7,9,11-dodecatrienyl formate] of the major sex pheromone component [(Z,E) 9,11,13-tetradecatrienal] of carob moth was assessed. Wind-tunnel bioassays demonstrated that the formate was as effective as natural gland extracts, and significantly more effective than the trienal alone or than the trienal blended with two minor pheromone components, in evoking source contact. Dispensers containing

J. L. Todd; J. G. Millar; R. S. Vetter; T. C. Baker

1992-01-01

229

The BPS spectrum of the 4d N=2 SCFT's H_1, H_2, D_4, E_6, E_7, E_8  

E-print Network

Extending results of arXiv:1112.3984, we show that all rank 1 N=2 SCFT's in the sequence H_1, H_2, D_4 E_6, E_7, E_8 have canonical finite BPS chambers containing precisely 2 h(F)=12(Delta-1) hypermultiplets. The BPS spectrum of the canonical BPS chambers saturates the conformal central charge c, and satisfies some intriguing numerology.

Cecotti, Sergio

2013-01-01

230

The BPS spectrum of the 4d N=2 SCFT's H_1, H_2, D_4, E_6, E_7, E_8  

E-print Network

Extending results of arXiv:1112.3984, we show that all rank 1 N=2 SCFT's in the sequence H_1, H_2, D_4 E_6, E_7, E_8 have canonical finite BPS chambers containing precisely 2 h(F)=12(Delta-1) hypermultiplets. The BPS spectrum of the canonical BPS chambers saturates the conformal central charge c, and satisfies some intriguing numerology.

Sergio Cecotti; Michele Del Zotto

2013-04-02

231

Late Intervention with anti-BRAFV600E Therapy Induces Tumor Regression in an Orthotopic Mouse Model of Human Anaplastic Thyroid Cancer  

PubMed Central

Human anaplastic thyroid cancer (ATC) is a lethal disease with an advanced clinical presentation and median survival of 3 months. The BRAFV600E oncoprotein is a potent transforming factor that causes human thyroid cancer cell progression in vitro and in vivo; therefore, we sought to target this oncoprotein in a late intervention model of ATC in vivo. We used the human ATC cell line 8505c, which harbors the BRAFV600E and TP53R248G mutations. Immunocompromised mice were randomized to receive the selective anti-BRAFV600E inhibitor, PLX4720, or vehicle by oral gavage 28 d after tumor implantation, 1 wk before all animals typically die due to widespread metastatic lung disease and neck compressive symptoms in this model. Mice were euthanized weekly to evaluate tumor volume and metastases. Control mice showed progressive tumor growth and lung metastases by 35 d after tumor implantation. At that time, all control mice had large tumors, were cachectic, and were euthanized due to their tumor-related weight loss. PLX4720-treated mice, however, showed a significant decrease in tumor volume and lung metastases in addition to a reversal of tumor-related weight loss. Mouse survival was extended to 49 d in PLX4720-treated animals. PLX4720 treatment inhibited cell cycle progression from 28 d to 49 d in vivo. PLX4720 induces striking tumor regression and reversal of cachexia in an in vivo model of advanced thyroid cancer that harbors the BRAFV600E mutation. PMID:22202162

Nehs, Matthew A.; Nucera, Carmelo; Nagarkatti, Sushruta S.; Sadow, Peter M.; Morales-Garcia, Dieter; Hodin, Richard A.

2012-01-01

232

The PCPH Oncoprotein Antagonizes the Proapoptotic Role of the Mammalian Target of Rapamycin in the Response of Normal Fibroblasts to Ionizing Radiation1  

Microsoft Academic Search

Exposure of normal mouse fibroblasts (MEF3T3) to ionizing radiation (IR) resulted in a dose-dependent increase of mTOR mRNA and protein levels and the shuttling of the mTOR protein from its normal, predomi- nantly mitochondrial location to the cell nucleus. The same IR doses that activated mTOR induced the phosphorylation of p53 on Ser18 (mouse equivalent to human Ser15) and the

Oscar M. Tirado; Silvia Mateo-Lozano; Sean Sanders; Luis E. Dettin; Vicente Notario

2003-01-01

233

Evidence for alteration of EZH2, BMI1, and KDM6A and epigenetic reprogramming in human papillomavirus type 16 E6/E7-expressing keratinocytes.  

PubMed

A number of epigenetic alterations occur in both the virus and host cellular genomes during human papillomavirus (HPV)-associated carcinogenesis, and investigations of such alterations, including changes in chromatin proteins and histone modifications, have the potential to lead to therapeutic epigenetic reversion. We report here that transformed HPV16 E6/E7-expressing primary human foreskin keratinocytes (HFKs) (E6/E7 cells) demonstrate increased expression of the PRC2 methyltransferase EZH2 at both the mRNA and protein levels but do not exhibit the expected increase in trimethylated H3K27 (H3K27me3) compared to normal keratinocytes. In contrast, these cells show a reduction in global H3K27me3 levels in vitro, as well as upregulation of the KDM6A demethylase. We further show for the first time that transformation with the HPV16 E6 and E7 oncogenes also results in an increase in phosphorylated EZH2 serine 21 (P-EZH2-Ser21), mediated by active Akt, and in a downregulation of the PRC1 protein BMI1 in these cells. High-grade squamous cervical intraepithelial lesions also showed a loss of H3K27me3 in the presence of increased expression of EZH2. Correlating with the loss of H3K27me3, E6/E7 cells exhibited derepression of specific EZH2-, KMD6A-, and BMI1-targeted HOX genes. These results suggest that the observed reduction in H3K27me3 may be due to a combination of reduced activities/levels of specific polycomb proteins and increases in demethylases. The dysregulation of multiple chromatin proteins resulting in the loss of global H3K27me3 and the transcriptional reprogramming in HPV16 E6/E7-infected cells could provide an epigenetic signature associated with risk and/or progression of HPV16-associated cancers, as well as the potential for epigenetic reversion in the future. PMID:21865393

Hyland, Paula L; McDade, Simon S; McCloskey, Rachel; Dickson, Glenda J; Arthur, Ken; McCance, Dennis J; Patel, Daksha

2011-11-01

234

Integrated analyses of genome-wide DNA occupancy and expression profiling identify key genes and pathways involved in cellular transformation by a Marek's disease virus oncoprotein, Meq.  

PubMed

Marek's disease (MD) is an economically significant disease in chickens that is caused by the highly oncogenic Marek's disease virus (MDV). A major unanswered question is the mechanism of MDV-induced tumor formation. Meq, a bZIP transcription factor discovered in the 1990s, is critically involved in viral oncogenicity, but only a few of its host target genes have been described, impeding our understanding of MDV-induced tumorigenesis. Using chromatin immunoprecipitation-sequencing (ChIP-seq) and microarray analysis, a high-confidence list of Meq binding sites in the chicken genome and a global transcriptome of Meq-responsive genes were generated. Meq binding sites were found to be enriched in the promoter regions of upregulated genes but not in those of downregulated genes. ChIP-seq was also performed for c-Jun, a known heterodimeric partner of Meq. The close location of binding sites of Meq and c-Jun was noted, suggesting cooperativity between these two factors in modulating transcription. Pathway analysis indicated that Meq transcriptionally regulates many genes that are part of several signaling pathways including the extracellular signal-regulated kinase /mitogen-activated protein kinase (ERK/MAPK), Jak-STAT, and ErbB pathways, which are critical for oncogenesis and/or include signaling mediators involved in apoptosis. Meq activates oncogenic signaling cascades by transcriptionally activating major kinases in the ERK/MAPK pathway and simultaneously repressing phosphatases, as verified using inhibitors of MEK and ERK1/2 in a cell proliferation assay. This study provides significant insights into the mechanistic basis of Meq-dependent cell transformation. PMID:23740999

Subramaniam, Sugalesini; Johnston, John; Preeyanon, Likit; Brown, C Titus; Kung, Hsing-Jien; Cheng, Hans H

2013-08-01

235

Acetylation of the human T-cell leukemia virus type 1 Tax oncoprotein by p300 promotes activation of the NF-{kappa}B pathway  

SciTech Connect

The oncogenic potential of the HTLV-1 Tax protein involves activation of the NF-{kappa}B pathway, which depends on Tax phosphorylation, ubiquitination and sumoylation. We demonstrate that the nuclei of Tax-expressing cells, including HTLV-1 transformed T-lymphocytes, contain a pool of Tax molecules acetylated on lysine residue at amino acid position 346 by the transcriptional coactivator p300. Phosphorylation of Tax on serine residues 300/301 was a prerequisite for Tax localization in the nucleus and correlated with its subsequent acetylation by p300, whereas sumoylation, resulting in the formation of Tax nuclear bodies in which p300 was recruited, favored Tax acetylation. Overexpression of p300 markedly increased Tax acetylation and the ability of a wild type HTLV-1 provirus, -but not of a mutant provirus carrying an acetylation deficient Tax gene-, to activate gene expression from an integrated NF-{kappa}B-controlled promoter. Thus, Tax acetylation favors NF-{kappa}B activation and might play an important role in HTLV-1-induced cell transformation.

Lodewick, Julie; Lamsoul, Isabelle; Polania, Angela; Lebrun, Sylvie [Institute for Microbiological Research J-M Wiame and Laboratory of Microbiology, Universite Libre de Bruxelles, 1, Avenue Emile Gryson, B-1070 Brussels (Belgium); Burny, Arsene [Faculte des Sciences Agronomiques de Gembloux, Gembloux (Belgium); Ratner, Lee [Division of Molecular Oncology, Washington University School of Medicine, St Louis (United States); Bex, Francoise [Institute for Microbiological Research J-M Wiame and Laboratory of Microbiology, Universite Libre de Bruxelles, 1, Avenue Emile Gryson, B-1070 Brussels (Belgium)], E-mail: fbex@ulb.ac.be

2009-03-30

236

Human Papillomavirus Genotyping and E6/E7 mRNA Expression in Greek Women with Intraepithelial Neoplasia and Squamous Cell Carcinoma of the Vagina and Vulva  

PubMed Central

A large proportion of vaginal and vulvar squamous cell carcinomas (SCCs) and intraepithelial neoplasias (VAIN and VIN) are associated with HPV infection, mainly type 16. The purpose of this study was to identify HPV genotypes, as well as E6/E7 mRNA expression of high-risk HPVs (16, 18, 31, 33, and 45) in 56 histology samples of VAIN, VIN, vaginal, and vulvar SCCs. HPV was identified in 56% of VAIN and 50% of vaginal SCCs, 71.4% of VIN and 50% of vulvar SCCs. E6/E7 mRNA expression was found in one-third of VAIN and in all vaginal SCCs, 42.9% of VIN and 83.3% of vulvar SCCs. Our data indicated that HPV 16 was the commonest genotype identified in VAIN and VIN and the only genotype found in SCCs of the vagina and vulva. These findings may suggest, in accordance with other studies, that mRNA assay might be useful in triaging lesions with increased risk of progression to cancer. PMID:22187556

Tsimplaki, Elpida; Argyri, Elena; Michala, Lina; Kouvousi, Maria; Apostolaki, Aikaterini; Magiakos, George; Papassideri, Issidora; Panotopoulou, Efstathia

2012-01-01

237

Effect of ferric ions on reactive oxygen species formation, cervical cancer cell lines growth and E6/E7 oncogene expression.  

PubMed

As iron ions may participate in the pathogenesis of cancer and viral infections, the aim of this study was to monitor their influence on proliferation, E6 and E7 oncogene expression and reactive oxygen species (ROS) production in two human papilloma virus (HPV) positive cervical carcinoma cell lines (HeLa and SiHa) and one HPV negative vulvar cell line (A431). The anti-anaemic drug, ferric-sorbitol-citric acid complex (FSC) as a source of Fe(III) ions was used. Cells were treated with FSC at the concentrations between 0.001 and 1 mM Fe(III) for different time periods. Fe(III) ions inhibited the viability of HeLa and A431 cells while it had no influence on SiHa cells. Furthermore, Fe(III) treatment showed a time-dependent and a higher stimulatory effect on E6/E7 expression in SiHa cells than in HeLa cells. Fe(III) ion treatment with concentrations lower than 0.1mM showed a time and a concentration dependent intracellular ROS production in all tested cell lines, while the treatment with 1mM concentration decreased ROS production in all tested cell lines. In conclusion, Fe(III) ion treatment apart from having an anti-tumour effect, as we previously described, enhances survival of HPV 16-positive cells and might be associated with HPV oncogenesis. PMID:21044880

Poljak-Blazi, Marija; Jaganjac, Morana; Sabol, Ivan; Mihaljevic, Branka; Matovina, Mihaela; Grce, Magdalena

2011-02-01

238

PEBP2/CBF, the murine homolog of the human myeloid AML1 and PEBP2 beta/CBF beta proto-oncoproteins, regulates the murine myeloperoxidase and neutrophil elastase genes in immature myeloid cells.  

PubMed Central

The myeloperoxidase (MPO) and neutrophil elastase genes are expressed specifically in immature myeloid cells. The integrity of a polyomavirus enhancer core sequence, 5'-AACCACA-3', is critical to the activity of the murine MPO proximal enhancer. This element binds two species, myeloid nuclear factors 1 alpha and 1 beta (MyNF1 alpha and -beta), present in 32D cl3 myeloid cell nuclear extracts. The levels of the MyNF1s increase during early 32D cl3 cell granulocytic differentiation. Both MyNF1 alpha and -beta supershift with an antiserum raised by using a peptide derived from the N terminus of polyomavirus enhancer-binding protein 2/core-binding factor (PEBP2/CBF) alpha subunit. The specific peptide inhibits these supershifts. In vitro-translated PEBP2/CBF DNA-binding domain binds the murine MPO PEBP2/CBF site. An alternate PEBP2/CBF consensus site, 5'-GACCGCA-3', but not a simian virus 40 enhancer core sequence, 5'-TTCCACA-3', binds the MyNF1s in vitro and activates a minimal murine MPO-thymidine kinase promoter in vivo. The murine neutrophil elastase gene 100-bp 5'-flanking sequences contain several functional elements, including potential binding sites for PU.1, C/EBP, c-Myb, and PEBP2/CBF. The functional element 5'-GGCCACA-3' located at positions -66 to 72 differs from the PEBP2/CBF consensus (5'-PuACCPuCA-3') only by an A-to-G transition at position 2. This DNA element binds MyNF1 alpha and -beta weakly. The N terminis of two PEBP2/CBF alpha subunit family members, PEBP2 alpha A and PEBP2 alpha B (murine AML1), are nearly identical, and 32D c13 cl3 cells contain both corresponding mRNAs. Since t(8;21), t(3;21), and inv(16), associated with myeloid leukemias, disrupt subunits of PEBP2/CBF, we speculate that the resulting oncoproteins, AML1-ETO, AML1-EAP, AML1-Evi1, and CBF beta-MYH11, inhibit early myeloid differentiation. Images PMID:8035830

Nuchprayoon, I; Meyers, S; Scott, L M; Suzow, J; Hiebert, S; Friedman, A D

1994-01-01

239

EAPB0503, a novel imidazoquinoxaline derivative, inhibits growth and induces apoptosis in chronic myeloid leukemia cells.  

PubMed

Imatinib, the first-generation tyrosine kinase inhibitor, revolutionized the therapeutic management of chronic myeloid leukemia (CML) and is highly effective in inducing remissions and prolonging the survival of CML patients. However, one-third of patients develop intolerance or resistance to treatment, and CML stem cells remain insensitive to this therapy, leading almost inevitably to relapse upon treatment discontinuation. Imidazoquinoxalines are imiquimod derivatives that induce growth inhibition and induction of caspase-dependent apoptosis in melanoma and T-cell lymphoma cells. We investigated the effects of EAPB0203 and EAPB0503, two novel imidazoquinoxaline derivatives, on human CML cell lines and showed that they induced a dose-dependent and time-dependent cell growth inhibition. EAPB0503 proved more potent and induced a specific cell cycle arrest in mitosis in CML cells and direct activation of apoptosis as evidenced by increased pre-G0 population, breakdown of mitochondrial membrane potential, PARP cleavage, and DNA breakage. Interestingly, EAPB0503 decreased BCR-ABL oncoprotein levels. The combination of EAPB0503 with imatinib synergized to inhibit the proliferation of CML cells, and most importantly, EABP0503 inhibited the proliferation of imatinib-resistant CML cells, offering promising therapeutic modalities that would circumvent resistance to tyrosine kinase inhibitors and improve the prognosis of CML. PMID:24463483

Saliba, Jessica; Deleuze-Masquéfa, Carine; Iskandarani, Ahmad; El Eit, Rabab; Hmadi, Raed; Mahon, François-Xavier; Bazarbachi, Ali; Bonnet, Pierre-Antoine; Nasr, Rihab

2014-07-01

240

Aptima HPV E6/E7 mRNA Test Is as Sensitive as Hybrid Capture 2 Assay but More Specific at Detecting Cervical Precancer and Cancer?  

PubMed Central

Detection of human papillomavirus (HPV) E6/E7 oncogene expression may be more predictive of cervical cancer risk than testing for HPV DNA. The Aptima HPV test (Gen-Probe) detects E6/E7 mRNA of 14 oncogenic types. Its clinical performance was compared with that of the Hybrid Capture 2 DNA test (HC2; Qiagen) in women referred for colposcopy and those routinely screened. Aptima was also compared with the PreTect HPV-Proofer E6/E7 mRNA assay (Proofer; Norchip) in the referral population. Cervical specimens collected in PreservCyt (Hologic Inc.) were processed for HPV detection and genotyping with the Linear Array (LA) method (Roche Molecular Diagnostics, Laval, Quebec, Canada). Histology-confirmed high-grade cervical intraepithelial neoplasia (CIN 2) or worse (CIN 2+) served as the disease endpoint. On the basis of 1,418 referral cases (CIN 2+, n = 401), the sensitivity of Aptima was 96.3% (95% confidence interval [CI], 94.4, 98.2), whereas it was 94.3% (95% CI, 92.0, 96.6) for HC2. The specificities were 43.2% (95% CI, 40.2, 46.2) and 38.7% (95% CI, 35.7, 41.7), respectively (P < 0.05). In 1,373 women undergoing routine screening (CIN 2+, n = 7), both Aptima and HC2 showed 100% sensitivity, and the specificities were 88.3% (95% CI, 86.6, 90.0) and 85.3% (95% CI, 83.5, 87.3), respectively (P < 0.05); for women ?30 years of age (n = 845), the specificities were 93.9% (95% CI, 92.3, 95.5) and 92.1% (95% CI, 90.3, 93.9), respectively (P < 0.05). On the basis of 818 referral cases (CIN 2+, n = 235), the sensitivity of Aptima was 94.9% (95% CI, 92.1, 97.7) and that of Proofer was 79.1% (95% CI, 73.9, 84.3), and the specificities were 45.8% (95% CI, 41.8, 49.8) and 75.1% (95% CI, 71.6, 78.6), respectively (P < 0.05). Both Aptima and Proofer showed a higher degree of agreement with LA genotyping than HC2. In conclusion, the Aptima test is as sensitive as HC2 but more specific for detecting CIN 2+ and can serve as a reliable test for both primary cervical cancer screening and the triage of borderline cytological abnormalities. PMID:21147950

Ratnam, Samuel; Coutlee, Francois; Fontaine, Dan; Bentley, James; Escott, Nicholas; Ghatage, Prafull; Gadag, Veeresh; Holloway, Glen; Bartellas, Elias; Kum, Nick; Giede, Christopher; Lear, Adrian

2011-01-01

241

Ligand binding to heme proteins: III. FTIR studies of His-E7 and Val-E11 mutants of carbonmonoxymyoglobin.  

PubMed Central

Fouier-transform infrared (FTIR) difference spectra of several His-E7 and Val-E11 mutants of sperm whale carbonmonoxymyoglobin were obtained by photodissociation at cryogenic temperatures. The IR absorption of the CO ligand shows characteristic features for each of the mutants, both in the ligand-bound (A) state and in the photodissociated (B) state. For most of the mutants, a single A substate band is observed, which points to the crucial role of the His-E7 residue in determining the A substrate spectrum of the bound CO in the native structure. The fact that some of the mutants show more than one stretch band of the bound CO indicates that the appearance of multiple A substates is not exclusively connected to the presence of His-E7. In all but one mutant, multiple stretch bands of the CO in the photodissociated state are observed; these B substates are thought to arise from discrete positions and/or orientations of the photodissociated ligand in the heme pocket. The red shifts of the B bands with respect to the free-gas frequency indicate weak binding in the heme pocket. The observation of similar red shifts in microperoxidase (MP-8), where there is no residue on the distal side, suggests that the photodissociated ligand is still associated with the heme iron. Photoselection experiments were performed to determine the orientation of the bound ligand with respect to the heme normal by photolyzing small fractions of the sample with linearly polarized light at 540 nm. The resulting linear dichroism in the CO stretch spectrum yielded angles alpha > 20 degrees between the CO molecular axis and the heme normal for all of the mutants. We conclude that the off-axis position of the CO ligand in the native structure does not arise from steric constraints imposed by the distal histidine. There is no clear correlation between the size of the distal residue and the alpha of the CO ligand. PMID:8312483

Braunstein, D. P.; Chu, K.; Egeberg, K. D.; Frauenfelder, H.; Mourant, J. R.; Nienhaus, G. U.; Ormos, P.; Sligar, S. G.; Springer, B. A.; Young, R. D.

1993-01-01

242

Proton electron nuclear double resonance from nitrosyl horse heart myoglobin: the role of His-E7 and Val-E11.  

PubMed Central

Electron nuclear double resonance (ENDOR) spectroscopy has been used to study protons in nitrosyl horse heart myoglobin (MbNO). (1)H ENDOR spectra were recorded for different settings of the magnetic field. Detailed analysis of the ENDOR powder spectra, using computer simulation, based on the "orientation-selection" principle, leads to the identification of the available protons in the heme pocket. We observe hyperfine interactions of the N(HisF8)-Fe(2+)-N(NO) complex with five protons in axial and with eight protons in the rhombic symmetry along different orientations, including those of the principal axes of the g-tensor. Protons from His-E7 and Val-E11 residues are identified in the two symmetries, rhombic and axial, exhibited by MbNO. Our results indicate that both residues are present inside the heme pocket and help to stabilize one particular conformation. PMID:10733988

Flores, M; Wajnberg, E; Bemski, G

2000-01-01

243

Partial glutathione reductase deficiency as a cause of diverse clinical manifestations in a family with unstable hemoglobin (Hemoglobin Haná, ?63(E7) His-Asn).  

PubMed

Hemoglobin Haná [?63(E7) His-Asn] is an unstable hemoglobin variant that was described in a Czech proband and her sister with Heinz body hemolytic anemia. The mother bearing the same mutation was asymptomatic; nevertheless, all three carriers had the same proportion of the mutant globin chains. Assessment of several erythrocyte antioxidant parameters revealed that both symptomatic children, unlike their asymptomatic mother, had significantly decreased glutathione reductase (GR) activity. Their GR activities were restorable in vitro by flavin adenine dinucleotide. The riboflavin supplementation improved their glutathione metabolism and ameliorated their hemolysis. Pre- and post-treatment assessment of the B(2) vitamers indicated suboptimal pre-treatment vitamin B(2) status in both children. This study provides evidence that partial GR deficiency may alter the clinical manifestation of an unstable hemoglobinopathy. PMID:20692194

Mojzikova, Renata; Dolezel, Petr; Pavlicek, Jiri; Mlejnek, Petr; Pospisilova, Dagmar; Divoky, Vladimir

2010-10-15

244

The PEI-introduced CS shell/PMMA core nanoparticle for silencing the expression of E6/E7 oncogenes in human cervical cells.  

PubMed

In this study, we examined the potential of cationic nanoparticle - polyethyleneimine-introduced chitosan shell/poly (methyl methacrylate) core nanoparticles (CS-PEI) for siRNA delivery. Initially, DNA delivery was performed to validate the capability of CS-PEI for gene delivery in the human cervical cancer cell line, SiHa. siRNA delivery were subsequently carried out to evaluate the silencing effect on targeted E6 and E7 oncogenes. Physicochemical properties including size, zeta potential and morphology of CS-PEI/DNA and CS-PEI/siRNA complexes, were analyzed. The surface charges and sizes of the complexes were observed at different N/P ratios. The hydrodynamic sizes of the CS-PEI/DNA and CS-PEI/siRNA were approximately 300-400 and 400-500nm, respectively. Complexes were positively charged depending on the amount of added CS-PEI. AFM images revealed the mono-dispersed and spherical shapes of the complexes. Gel retardation assay confirmed that CS-PEI nanoparticles completely formed complexes with DNA and siRNA at a N/P ratio of 1.6. For DNA transfection, CS-PEI provided the highest transfection result. Localization of siRNA delivered through CS-PEI was confirmed by differential interference contrast (DIC) confocal imaging. The silencing effect of siRNA specific to HPV 16 E6/E7 oncogene was examined at 18 and 24h post-transfection. The results demonstrated the capacity of CS-PEI to suppress the expression of HVP oncogenes. PMID:22939347

Saengkrit, Nattika; Sanitrum, Phakorn; Woramongkolchai, Noppawan; Saesoo, Somsak; Pimpha, Nuttaporn; Chaleawlert-Umpon, Saowaluk; Tencomnao, Tewin; Puttipipatkhachorn, Satit

2012-10-15

245

MINI REVIEW MECHANISMS OF GENOMIC INSTABILITY IN HUMAN CANCER: INSIGHTS  

E-print Network

PAPILLOMAVIRUS ONCOPROTEINS Stefan DUENSING 1 * and Karl M¨UNGER 2 * 1 Molecular Virology Program, University-risk human papillomavirus (HPV)-associated anogenital neoplasia. The two HPV-encoded oncoproteins, E6 and E7 carcinogenesis. © 2003 Wiley-Liss, Inc. Human papillomaviruses (HPVs) are small DNA tumor viruses that cause

Dever, Jennifer A.

246

Metformin induces differentiation in acute promyelocytic leukemia by activating the MEK/ERK signaling pathway  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer Metformin induces differentiation in NB4 and primary APL cells. Black-Right-Pointing-Pointer Metformin induces activation of the MEK/ERK signaling pathway in APL cells. Black-Right-Pointing-Pointer Metformin synergizes with ATRA to trigger maturation of NB4 and primary APL cells. Black-Right-Pointing-Pointer Metformin induces the relocalization and degradation of the PML-RAR{alpha} fusion protein. Black-Right-Pointing-Pointer The study may be applicable for new differentiation therapy in cancer treatment. -- Abstract: Recent studies have shown that metformin, a widely used antidiabetic agent, may reduce the risk of cancer development. In this study, we investigated the antitumoral effect of metformin on both acute myeloid leukemia (AML) and acute promyelocytic leukemia (APL) cells. Metformin induced apoptosis with partial differentiation in an APL cell line, NB4, but only displayed a proapoptotic effect on several non-M3 AML cell lines. Further analysis revealed that a strong synergistic effect existed between metformin and all-trans retinoic acid (ATRA) during APL cell maturation and that metformin induced the hyperphosphorylation of extracellular signal-regulated kinase (ERK) in APL cells. U0126, a specific MEK/ERK activation inhibitor, abrogated metformin-induced differentiation. Finally, we found that metformin induced the degradation of the oncoproteins PML-RAR{alpha} and c-Myc and activated caspase-3. In conclusion, these results suggest that metformin treatment may contribute to the enhancement of ATRA-induced differentiation in APL, which may deepen the understanding of APL maturation and thus provide insight for new therapy strategies.

Huai, Lei; Wang, Cuicui; Zhang, Cuiping; Li, Qihui; Chen, Yirui; Jia, Yujiao; Li, Yan; Xing, Haiyan; Tian, Zheng; Rao, Qing; Wang, Min [State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300020 (China)] [State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300020 (China); Wang, Jianxiang, E-mail: wangjx@ihcams.ac.cn [State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300020 (China)] [State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300020 (China)

2012-06-08

247

Intercellular trafficking of the nuclear oncoprotein DEK  

E-print Network

DEK is a biochemically distinct, conserved nonhistone protein that is vital to global heterochromatin integrity. In addition, DEK can be secreted and function as a chemotactic, proinflammatory factor. Here we show that ...

Ploegh, Hidde

248

Triage of Women with Minor Cervical Lesions: Data Suggesting a “Test and Treat” Approach for HPV E6/E7 mRNA Testing  

PubMed Central

Background Human papillomavirus (HPV) testing is included in the cervical cancer screening program in the triage of women with equivocal (ASC-US) or low-grade (LSIL) cytological lesions. These women have an increased risk for developing high grade dysplasia and cancer (CIN2+) compared to women with normal cytology. However, in order to avoid unnecessary follow-up, as well as overtreatment, a high positive predictive value (PPV) of the triage test is important. Methodology/Principal Findings The HPV test PreTect HPV-Proofer, detecting E6/E7 mRNA from the HPV types 16, 18, 31, 33 and 45, is used as triage test together with repeat cytology. PPV data for HPV E6/E7 mRNA testing during the period from January 2006 up to June 2009 are reported. In total, 406 of 2099 women (19.3%) had a positive HPV test result. Of the women with a positive test result and with a histological diagnosis (n?=?347), 243 women had histological high-grade dysplasia or cancer (CIN2+), giving a PPV of 70.0% (95% confidence interval [CI], 65.2%–74.8%). For HPV 16 or HPV 33 positive women above 40 years of age, the PPV was 83.7% (95% CI, 73.3%–94.0%) and 84.6% (95% CI, 65.0%–100.0%) respectively. The PPV of test positive women with HSIL cytology was 94.2% (95% CI, 88.7%–99.7%). Conclusions When the result in triage is HPV mRNA positive, our data suggest direct treatment for women above 40 years of age or for women with a concurrent cytological HSIL diagnosis, contributing to better clinical safety for these women. In addition, by decreasing the time to treatment, thereby reducing the number of recalls, the patient management algorithm will be considerably improved, in turn reducing follow-up costs as well as unnecessary psychological stress among patients. PMID:20856930

Sørbye, Sveinung Wergeland; Fismen, Silje; Gutteberg, Tore; Mortensen, Elin Synnøve

2010-01-01

249

HPV E6/E7 RNA In Situ Hybridization Signal Patterns as Biomarkers of Three-Tier Cervical Intraepithelial Neoplasia Grade  

PubMed Central

Cervical lesion grading is critical for effective patient management. A three-tier classification (cervical intraepithelial neoplasia [CIN] grade 1, 2 or 3) based on H&E slide review is widely used. However, for reasons of considerable inter-observer variation in CIN grade assignment and for want of a biomarker validating a three-fold stratification, CAP-ASCCP LAST consensus guidelines recommend a two-tier system: low- or high-grade squamous intraepithelial lesions (LSIL or HSIL). In this study, high-risk HPV E6/E7 and p16 mRNA expression patterns in eighty-six CIN lesions were investigated by RNAscope chromogenic in situ hybridization (CISH). Specimens were also screened by immunohistochemistry for p16INK4a (clone E6H4), and by tyramide-based CISH for HPV DNA. HPV genotyping was performed by GP5+/6+ PCR combined with cycle-sequencing. Abundant high-risk HPV RNA CISH signals were detected in 26/32 (81.3%) CIN 1, 22/22 (100%) CIN 2 and in 32/32 (100%) CIN 3 lesions. CIN 1 staining patterns were typified (67.7% specimens) by abundant diffusely staining nuclei in the upper epithelial layers; CIN 2 lesions mostly (66.7%) showed a combination of superficial diffuse-stained nuclei and multiple dot-like nuclear and cytoplasmic signals throughout the epithelium; CIN 3 lesions were characterized (87.5%) by multiple dot-like nuclear and cytoplasmic signals throughout the epithelial thickness and absence/scarcity of diffusely staining nuclei (trend across CIN grades: P<0.0001). These data are consistent with productive phase HPV infections exemplifying CIN 1, transformative phase infections CIN 3, whereas CIN 2 shows both productive and transformative phase elements. Three-tier data correlation was not found for the other assays examined. The dual discernment of diffuse and/or dot-like signals together with the assay’s high sensitivity for HPV support the use of HPV E6/E7 RNA CISH as an adjunct test for deciding lesion grade when CIN 2 grading may be beneficial (e.g. among young women) or when ‘LSIL vs. HSIL’ assignment is equivocal. PMID:24625757

Evans, Mark F.; Peng, Zhihua; Clark, Kelli M.; Adamson, Christine S.-C.; Ma, Xiao-Jun; Wu, Xingyong; Wang, Hongwei; Luo, Yuling; Cooper, Kumarasen

2014-01-01

250

Acetylshikonin induces apoptosis of hepatitis B virus X protein-expressing human hepatocellular carcinoma cells via endoplasmic reticulum stress.  

PubMed

Since it has been known that shikonin derived from a medicinal plant possesses anti-cancer activity, we wonder whether acetylshikonin (ASK), a derivate of shikonin, can be used to treat hepatocellular carcinoma cells expressing hepatitis B virus X protein (HBX), an oncoprotein from hepatitis B virus. When ASK was added to Hep3B cells stably expressing HBX, it induced apoptosis in a dose-dependent manner. ASK induced upregulation and export of Nur77 to the cytoplasm and activation of JNK. Likewise, suppression of Nur77 and JNK inactivation protected the cells from ASK-induced apoptosis, indicating that Nur77 upregulation and JNK activation were required for ASK-mediated apoptosis. Furthermore, ASK increased the expression of Bip and ubiquitination levels of cellular proteins, features of endoplasmic reticulum (ER) stress, via the production of reactive oxygen species in a dose-dependent manner. Suppression of reactive oxygen species with N-acetylcysteine reduced levels of Bip protein and ubiquitination levels of cellular proteins during ASK treatment, leading to protection of cells from apoptosis. Cycloheximide treatment reduced ASK-induced ER stress, suggesting that protein synthesis is involved in ASK-induced ER stress. Moreover, we showed using salubrinal, an ER stress inhibitor that reactive oxygen species production, JNK activation, and Nur77 upregulation and its translocation to cytoplasm are necessary for ER-induced stress. Interestingly, we found that JNK inactivation suppresses ASK-induced ER stress, whereas Nur77 siRNA treatment does not, indicating that JNK is required for ASK-induced ER stress. Accordingly, we report that ASK induces ER stress, which is prerequisite for apoptosis of HBX-expressing hepatocellular carcinoma cells. PMID:24769509

Moon, Jeong; Koh, Sang Seok; Malilas, Waraporn; Cho, Il-Rae; Kaewpiboon, Chutima; Kaowinn, Sirichat; Lee, Keesook; Jhun, Byung Hak; Choi, Young Whan; Chung, Young-Hwa

2014-07-15

251

Bcl-3 suppresses Tax-induced NF-?B activation through p65 nuclear translocation blockage in HTLV-1-infected cells.  

PubMed

Human T cell leukemia virus type 1 (HTLV-1) Tax-induced persistent activation of the NF-?B pathway is perceived as the primary cause of adult T cell leukemia (ATL), an aggressive leukemia caused by HTLV-1. Although elevated oncoprotein Bcl-3 levels are found in many HTLV-1-infected T cell lines and ATL cells, the role of Bcl-3 in the malignant progression caused by HTLV-1 retrovirus remains poorly understood. We confirmed, in the present study, that the Tax-induced NF-?B activation involves the regulation of Bcl-3. Both knockdown and overexpression of Bcl-3 inhibit the Tax-induced NF-?B activation. Similarly, excessive Bcl-3 inhibits the NF-?B/DNA binding activity and significantly decreases Tax-induced p65 nuclear translocation. The present results demonstrate the pleiotropic roles of Bcl-3 in Tax-induced NF-?B activation and indicate that a balance in the aberrant Bcl-3 expression may be established to play an important role in the maintenance of proliferation and inhibition of apoptosis in HTLV-1-infected and ATL cells. PMID:23135533

Wang, Jinheng; Li, Junying; Huang, Yanmei; Song, Xiangfeng; Niu, Zhiguo; Gao, Zhitao; Wang, Hui

2013-01-01

252

Biosynthesis of the Cyanogenic Glucosides Linamarin and Lotaustralin in Cassava: Isolation, Biochemical Characterization, and Expression Pattern of CYP71E7, the Oxime-Metabolizing Cytochrome P450 Enzyme1[OA  

PubMed Central

Cassava (Manihot esculenta) is a eudicotyledonous plant that produces the valine- and isoleucine-derived cyanogenic glucosides linamarin and lotaustralin with the corresponding oximes and cyanohydrins as key intermediates. CYP79 enzymes catalyzing amino acid-to-oxime conversion in cyanogenic glucoside biosynthesis are known from several plants including cassava. The enzyme system converting oxime into cyanohydrin has previously only been identified in the monocotyledonous plant great millet (Sorghum bicolor). Using this great millet CYP71E1 sequence as a query in a Basic Local Alignment Search Tool-p search, a putative functional homolog that exhibited an approximately 50% amino acid sequence identity was found in cassava. The corresponding full-length cDNA clone was obtained from a plasmid library prepared from cassava shoot tips and was assigned CYP71E7. Heterologous expression of CYP71E7 in yeast afforded microsomes converting 2-methylpropanal oxime (valine-derived oxime) and 2-methylbutanal oxime (isoleucine-derived oxime) to the corresponding cyanohydrins, which dissociate into acetone and 2-butanone, respectively, and hydrogen cyanide. The volatile ketones were detected as 2.4-dinitrophenylhydrazone derivatives by liquid chromatography-mass spectrometry. A KS of approximately 0.9 ?m was determined for 2-methylbutanal oxime based on substrate-binding spectra. CYP71E7 exhibits low specificity for the side chain of the substrate and catalyzes the conversion of aliphatic and aromatic oximes with turnovers of approximately 21, 17, 8, and 1 min?1 for the oximes derived from valine, isoleucine, tyrosine, and phenylalanine, respectively. A second paralog of CYP71E7 was identified by database searches and showed approximately 90% amino acid sequence identity. In tube in situ polymerase chain reaction showed that in nearly unfolded leaves, the CYP71E7 paralogs are preferentially expressed in specific cells in the endodermis and in most cells in the first cortex cell layer. In fully unfolded leaves, the expression is pronounced in the cortex cell layer just beside the epidermis and in specific cells in the vascular tissue cortex cells. Thus, the transcripts of the CYP71E7 paralogs colocalize with CYP79D1 and CYP79D2. We conclude that CYP71E7 is the oxime-metabolizing enzyme in cyanogenic glucoside biosynthesis in cassava. PMID:21045121

Jørgensen, Kirsten; Morant, Anne Vinther; Morant, Marc; Jensen, Niels Bjerg; Olsen, Carl Erik; Kannangara, Rubini; Motawia, Mohammed Saddik; Møller, Birger Lindberg; Bak, Søren

2011-01-01

253

Sequential Cisplatin Therapy and Vaccination with HPV16 E6E7L2 Fusion Protein in Saponin Adjuvant GPI-0100 for the Treatment of a Model HPV16+ Cancer  

PubMed Central

Clinical studies suggest that responses to HPV16 E6E7L2 fusion protein (TA-CIN) vaccination alone are modest, and GPI-0100 is a well-tolerated, potent adjuvant. Here we sought to optimize both the immunogenicity of TA-CIN via formulation with GPI-0100 and treatment of HPV16+ cancer by vaccination after cisplatin chemotherapy. HPV16 neutralizing serum antibody titers, CD4+ T cell proliferative and E6/E7-specific CD8+ T cell responses were significantly enhanced when mice were vaccinated subcutaneously (s.c.) or intramuscularly (i.m.) with TA-CIN formulated with GPI-0100. Vaccination was tested for therapy of mice bearing syngeneic HPV16 E6/E7+ tumors (TC-1) either in the lung or subcutaneously. Mice treated with TA-CIN/GPI-0100 vaccination exhibited robust E7-specific CD8+ T cell responses, which were associated with reduced tumor burden in the lung, whereas mice receiving either component alone were similar to controls. Since vaccination alone was not sufficient for cure, mice bearing s.c. TC-1 tumor were first treated with two doses of cisplatin and then vaccinated. Vaccination with TA-CIN/GPI-0100 i.m. substantially retarded tumor growth and extended survival after cisplatin therapy. Injection of TA-CIN alone, but not GPI-0100, into the tumor (i.t.) was similarly efficacious after cisplatin therapy, but the mice eventually succumbed. However, tumor regression and extended remission was observed in 80% of the mice treated with cisplatin and then intra-tumoral TA-CIN/GPI-0100 vaccination. These mice also exhibited robust E7-specific CD8+ T cell and HPV16 neutralizing antibody responses. Thus formulation of TA-CIN with GPI-0100 and intra-tumoral delivery after cisplatin treatment elicits potent therapeutic responses in a murine model of HPV16+ cancer. PMID:25560237

Peng, Shiwen; Wang, Joshua W.; Karanam, Balasubramanyam; Wang, Chenguang; Huh, Warner K.; Alvarez, Ronald D.; Pai, Sara I.; Hung, Chien-fu; Wu, T. -C.; Roden, Richard B. S.

2015-01-01

254

Oncogenic c-Myc and prothymosin-alpha protect hepatocellular carcinoma cells against sorafenib-induced apoptosis.  

PubMed

Prothymosin alpha (PTMA) is overexpressed in various human tumors, including hepatocellular carcinoma (HCC). The significance of PTMA overexpression and its underlying mechanism remain unclear. We show here that silencing PTMA sensitizes HCC cells to the kinase inhibitor sorafenib. In contrast, ectopic expression of PTMA induces cell resistance to the drug. While inhibitors targeting JNK, ERK or PI3K reduce PTMA expression, only ERK activation is suppressed by sorafenib. In addition, inhibition of ERK produces a dramatic decrease in both endogenous PTMA level and promoter activation. Ectopic expression of active MKK1/2 considerably induces PTMA expression. We also identify a sorafenib-responsive segment lying 1000-1500-bp upstream of the PTMA transcription start site and observe that it is controlled by c-Myc and ERK. Mutation in the PTMA promoter at the predicted c-Myc binding site and silencing of c-Myc both abrogate sorafenib's effect on PTMA transcription. We also find that silencing PTMA potentiates Bax translocation to mitochondria in response to sorafenib and this is associated with increased cytochrome c release from mitochondria and enhanced caspase-9 activation. These results indicate that PTMA is positively regulated by the oncoprotein c-Myc and protects HCC cells against sorafenib-induced cell death, thus identifying PTMA as a new target for chemotherapy against HCC. PMID:25451688

Lin, Yi-Te; Lu, Hsing-Pang; Chao, Chuck C-K

2015-01-01

255

CD4+ T cell-mediated antigen-specific immunotherapy in a mouse model of cervical cancer.  

PubMed

A major agenda for tumor immunology is the generation of specific immune responses leading to the destruction of incipient and frank neoplasia. In this report, we show that a novel HPV16 E7 fusion protein can produce objective therapeutic responses against incipient cervical cancer in genetically engineered mice that express in the cervix the HPV16 early region genes implicated as causative agents in human cervical cancer. Although nonresponsive toward the HPV16 E7 oncoprotein in the CD8+ T-cell compartment by virtue of MHC haplotype, the mice were capable of mounting an induced CD4+ T-cell response against E7, and in addition developed spontaneous anti-E7 antibodies. HPV16/CD4-/- mice showed increased tumor burden indicative of CD4-mediated immune surveillance. Seeking to enhance the CD4 response, we immunized mice bearing incipient cervical cancer with a recombinant protein fusing E7 with a mycobacterial heat shock protein. The incidences of cervical carcinoma and of high-grade dysplasia (CIN 3) were consequently reduced by comparison to control mice. Thus, an HPV16 E7 immunogen holds promise for noninvasive treatment and prevention of human cervical cancer. PMID:15753402

Daniel, Dylan; Chiu, Christopher; Giraudo, Enrico; Inoue, Masahiro; Mizzen, Lee A; Chu, N Randall; Hanahan, Douglas

2005-03-01

256

Scientific American: The Promise of the Blue Revolution (Extended ver... http://www.sciam.com/print_version.cfm?articleID=2B10ECE2-E7F2-... 1 of 2 6/27/2007 10:27 AM  

E-print Network

Scientific American: The Promise of the Blue Revolution (Extended ver... http://www.sciam.com/print_version.cfm?articleID=2B10ECE2-E7F2-... 1 of 2 6/27/2007 10:27 AM June 17, 2007 The Promise of the Blue Revolution ecosystems. The rapid development of aquaculture in recent years has been likened to a "Blue Revolution

257

GLI1 Is a Direct Transcriptional Target of EWS-FLI1 Oncoprotein*S?  

PubMed Central

Ewing sarcoma family of tumors (ESFT) is an undifferentiated neoplasm of the bone and soft tissue. ESFT is characterized by a specific chromosomal translocation occurring between chromosome 22 and (in most cases) chromosome 11, which generates an aberrant transcription factor, EWS-FLI1. The function of EWS-FLI1 is essential for the maintenance of ESFT cell survival and tumorigenesis. The Hedgehog pathway is activated in several cancers. Oncogenic potential of the Hedgehog pathway is mediated by increasing the activity of the GLI family of transcription factors. Recent evidence suggests that EWS-FLI1 increases expression of GLI1 by an unknown mechanism. Our data from chromatin immunoprecipitation and promoter reporter studies indicated GLI1 as a direct transcriptional target of EWS-FLI1. Expression of EWS-FLI1 in non-ESFT cells increased GLI1 expression and GLI-dependent transcription. We also detected high levels of GLI1 protein in ESFT cell lines. Pharmacological inhibition of GLI1 protein function decreased proliferation and soft agar colony formation of ESFT cells. Our results establish GLI1 as a direct transcriptional target of EWS-FLI1 and suggest a potential role for GLI1 in ESFT tumorigenesis. PMID:19189974

Beauchamp, Elspeth; Bulut, Gulay; Abaan, Ogan; Chen, Kevin; Merchant, Akil; Matsui, William; Endo, Yoshimi; Rubin, Jeffrey S.; Toretsky, Jeffrey; Üren, Aykut

2009-01-01

258

Knockdown of Bcl-3 inhibits cell growth and induces DNA damage in HTLV-1-infected cells.  

PubMed

Oncoprotein Bcl-3 is perceived as an unusual member of I?B family since it can both stimulate and suppress NF-?B activation. Aberrant Bcl-3 results in increased cell proliferation and survival, suggesting a contribution to malignant potential and elevated levels of Bcl-3 have been observed in many HTLV-1-infected T cell lines and ATL cells. To investigate the specific roles of Bcl-3 in HTLV-1-infected cells, we knocked down Bcl-3 expression using shRNA and then examined the consequences with regard to DNA damage and cell proliferation, as well as NF-?B activation. The HTLV-1 encoded protein Tax promotes Bcl-3 expression and nuclear translocation. In HTLV-1-infected cells, Bcl-3 knockdown obviously induced DNA damage. Cell growth and NF-?B activation were reduced in HTLV-1-infected or Tax positive cells when Bcl-3 expression was decreased. Together, our results revealed positive roles of Bcl-3 in DNA stabilization, growth and NF-?B activation in HTLV-1-infected cells. PMID:23534762

Gao, Cai; Wang, Xia; Chen, Lin; Wang, Jin-Heng; Gao, Zhi-Tao; Wang, Hui

2013-01-01

259

Phosphorylated ezrin is associated with EBV latent membrane protein 1 in nasopharyngeal carcinoma and induces cell migration  

PubMed Central

Tumor metastasis is a complex phenomenon that is the culmination of effects of numerous cellular factors. We have shown that the EBV oncoprotein, latent membrane protein 1 (LMP1), is capable of inducing a wide range of such factors in cell culture, expression of which is also elevated in the LMP1-expressing tumor, nasopharyngeal carcinoma (NPC), a highly invasive neoplasm. Recently, the membrane-crosslinker protein ezrin has been implicated in tumor cell metastasis and malignant progression. In this study, we evaluated the possible role of LMP1 and ezrin in the pathophysiology of NPC. We show that C-terminal phosphorylation of ezrin is increased by expression of LMP1 in nasopharyngeal (NP) cells through a Protein Kinase C (PKC) pathway. LMP1 enhances organization of a ternary complex of CD44, ezrin and F-actin which is a prerequisite for ezrin phosphorylation. In NPC tissues, expression of phosphoezrin and LMP1 is directly correlated. Silencing of endogenously expressed ezrin suppresses LMP1-induced cell motility and invasiveness. Moreover inhibition of ezrin phosphorylation by PKC inhibitor suppresses migration and invasion of NP cells. These data demonstrate that phosphorylation of ezrin and its recruitment to the cell membrane linked to F-actin and CD44 is a process required for LMP1-stimulated cell motility and invasion of NP cells. PMID:19234486

Endo, Kazuhira; Kondo, Satoru; Shackleford, Julia; Horikawa, Toshiyuki; Kitagawa, Noriko; Yoshizaki, Tomokazu; Furukawa, Mitsuru; Zen, Yoh; Pagano, Joseph S.

2009-01-01

260

Gamma-radiation-induced ATM-dependent signalling in human T-lymphocyte leukemic cells, MOLT-4.  

PubMed

ATM kinase (ATM) is essential for activation of cell cycle check points and DNA repair in response to ionizing radiation (IR). In this work we studied the molecular mechanisms regulating DNA repair and cell death in human T-lymphocyte leukemic cells, MOLT-4. Apoptosis was evaluated by flow-cytometric detection of annexin V. Early apoptotic cells were determined as sub-G1 cells and late apoptotic cells were determined as APO2.7-positive ones. Proteins involved in ATM signalling pathway were analysed by Western-blotting. We observed a rapid (0.5 h) phosphorylation of ATM declining after 6 h after irradiation by all the doses studied (1.5, 3.0, and 7.5 Gy). Checkpoint kinase-2 (Chk-2) was also phosphorylated after 0.5 h but its phosphorylated form persisted 4, 2, and 1 h after the doses of 1.5, 3.0, and 7.5 Gy, respectively. The amount of p53 protein and its form phosphorylated on Ser-392 increased 1 h after irradiation (1-10 Gy). The lethal dose of 7.5 Gy caused an immediate induction and phosphorylation of p53 after 0.5 h post-irradiation. At the time of phosphorylation of p53, we found simultaneous phosphorylation of the oncoprotein Mdm2 on Ser-166. Neither ATM nor its downstream targets showed a dose-dependent response after 1 h when irradiated by the doses of 1-10 Gy. MOLT-4 cells were very sensitive to the effect of IR. Even low doses, such as 1.5 Gy, induced apoptosis 16 h after irradiation (evaluated according to the cleavage of nuclear lamin B to a 48-kDa fragment). IR-induced molecular signalling after exposure to all the tested doses was triggered by rapid phosphorylation of ATM and Chk-2. Subsequent induction of p53 protein and its phosphorylation was accompanied by concomitant phosphorylation of its negative regulator, oncoprotein Mdm2, and followed by induction of apoptosis. PMID:17565390

Tichý, Ales; Záskodová, Darina; Rezácová, Martina; Vávrová, Jirina; Vokurková, Doris; Pejchal, Jaroslav; Vilasová, Zdena; Cerman, Jaroslav; Osterreicher, Jan

2007-01-01

261

Restoration of MAGI-1 Expression in Human Papillomavirus-Positive Tumor Cells Induces Cell Growth Arrest and Apoptosis  

PubMed Central

ABSTRACT The cancer-causing high-risk human papillomavirus (HPV) E6 oncoproteins target a number of cellular proteins that contain PDZ domains. However, the role of many of these interactions in either the HPV life cycle or in HPV-induced malignancy remains to be defined. Previous studies had shown that MAGI-1 was one of the most strongly bound PDZ domain-containing substrates of E6, and one consequence of this interaction appeared to facilitate the perturbation of tight junctions (TJs) by E6. In this study, we describe the generation of a mutation, K499E, within the MAGI-1 PDZ1 domain, which is resistant to E6 targeting. This mutant allows restoration of MAGI-1 expression in HPV-positive cells and defines additional activities of MAGI-1 that are overcome as a consequence of the association with E6. The reexpression of MAGI-1 in HPV-positive cells results in an increased recruitment of ZO-1 and PAR3 to sites of cell-cell contact, repression of cell proliferation, and induction of apoptosis. While the K499E mutation does not significantly affect these intrinsic activities of MAGI-1 in HPV-negative cells, its resistance to E6 targeting in an HPV-positive setting results in more cells expressing the mutant MAGI-1 than the wild-type MAGI-1, with a corresponding increase in TJ assembly, induction of apoptosis, and reduction in cell proliferation. These studies provide compelling evidence of a direct role for the perturbation of MAGI-1 function by E6 in the HPV life cycle and in HPV-induced malignancy. IMPORTANCE It is clear that the targeting of PDZ-containing substrates by E6 is important for the normal viral life cycle and for the progression to malignancy. Nevertheless, which of these PDZ domain-containing proteins is relevant for HPV pathology is still elusive. In a previous study, we provided evidence that MAGI-1 is a sensitive proteolytic substrate for both the HPV-16 and HPV-18 E6 oncoproteins; however, the biological consequences associated with loss of MAGI-1 expression in HPV-positive cervical cancer cells are still poorly understood. Using a mutant MAGI-1, resistant to E6-mediated degradation, we show that its expression in cervical cancer cells promotes membrane recruitment of the tight junction-associated proteins ZO-1 and PAR3, represses cell proliferation, and promotes apoptosis. These findings suggest that E6-mediated inhibition of MAGI-1 function contributes to HPV pathology by perturbing tight junction assembly with concomitant stimulation of proliferation and inhibition of apoptosis. PMID:24696483

Kranjec, Christian; Massimi, Paola

2014-01-01

262

Molecular dynamics simulations of retinoblastoma protein.  

PubMed

Tumor suppressor proteins play a crucial role in cell cycle regulation. Retinoblastoma protein (pRB) is one among them which regulates G1-S transition by binding with transcription factors. The activity of pRB is deregulated by cyclin dependent kinases-mediated hyper-phosphorylation and also due to cancer-derived mutations. In addition, it is also deactivated by binding of viral onco-proteins such as large T antigen, E1A, and E7. These viral proteins initially recognize pRB through their conserved LxCxE motif and facilitate dissociation of preexisting pRB-E2F complex. Based on these features, molecular dynamics (MD) simulation is performed for four different states of pRB for which the crystal structure is available. The unliganded/apo form and complex forms with E2F and E7 peptides reveal the molecular mechanism behind the activation and inactivation of pRB. In addition, the ternary complex of pRB with both E7 and E2F (for which no crystal structure is available) is modeled and simulated to understand the influence of binding of one ligand on the other. The variations in the three major factors such as conformational changes, inter- and intra-molecular interactions, and binding free energies between the apo and complex forms confirm the possibility for designing a small molecule inhibitor to inhibit pRB-E7 interactions without altering the prebound E2F. The present study deals with the molecular modeling and MD simulations of pRB in free and ligand-bound forms and confirms that pRB could be a valid target for the anticancer drug design when the cancer is induced by the viral onco-proteins and forms a clear base for designing E7 antagonists. PMID:23157310

Ramakrishnan, C; Subramanian, V; Balamurugan, K; Velmurugan, D

2013-01-01

263

Histone deacetylase 2 and N-Myc reduce p53 protein phosphorylation at serine 46 by repressing gene transcription of tumor protein 53-induced nuclear protein 1  

PubMed Central

Myc oncoproteins and histone deacetylases (HDACs) exert oncogenic effects by modulating gene transcription. Paradoxically, N-Myc induces p53 gene expression. Tumor protein 53-induced nuclear protein 1 (TP53INP1) phosphorylates p53 protein at serine 46, leading to enhanced p53 activity, transcriptional activation of p53 target genes and programmed cell death. Here we aimed to identify the mechanism through which N-Myc overexpressing p53 wild-type neuroblastoma cells acquired resistance to apoptosis. TP53INP1 was found to be one of the genes most significantly repressed by HDAC2 and N-Myc according to Affymetrix microarray gene expression datasets. HDAC2 and N-Myc reduced TP53INP1 gene expression by direct binding to the TP53INP1 gene promoter, leading to transcriptional repression of TP53INP1, p53 protein de-phosphorylation at serine 46, neuroblastoma cell proliferation and survival. Moreover, low levels of TP53INP1 expression in human neuroblastoma tissues correlated with high levels of N-Myc expression and poor patient outcome, and the BET bromodomain inhibitors JQ1 and I-BET151 reduced N-Myc expression and reactivated TP53INP1 expression in neuroblastoma cells. These findings identify TP53INP1 repression as an important co-factor for N-Myc oncogenesis, and provide further evidence for the potential application of BET bromodomain inhibitors in the therapy of N-Myc-induced neuroblastoma. PMID:24952595

Shahbazi, Jeyran; Scarlett, Christopher J.; Norris, Murray D.; Liu, Bing; Haber, Michelle; Tee, Andrew E.; Carrier, Alice; Biankin, Andrew V.; London, Wendy B.; Marshall, Glenn M.; Lock, Richard B.; Liu, Tao

2014-01-01

264

Histone deacetylase 2 and N-Myc reduce p53 protein phosphorylation at serine 46 by repressing gene transcription of tumor protein 53-induced nuclear protein 1.  

PubMed

Myc oncoproteins and histone deacetylases (HDACs) exert oncogenic effects by modulating gene transcription. Paradoxically, N-Myc induces p53 gene expression. Tumor protein 53-induced nuclear protein 1 (TP53INP1) phosphorylates p53 protein at serine 46, leading to enhanced p53 activity, transcriptional activation of p53 target genes and programmed cell death. Here we aimed to identify the mechanism through which N-Myc overexpressing p53 wild-type neuroblastoma cells acquired resistance to apoptosis. TP53INP1 was found to be one of the genes most significantly repressed by HDAC2 and N-Myc according to Affymetrix microarray gene expression datasets. HDAC2 and N-Myc reduced TP53INP1 gene expression by direct binding to the TP53INP1 gene promoter, leading to transcriptional repression of TP53INP1, p53 protein de-phosphorylation at serine 46, neuroblastoma cell proliferation and survival. Moreover, low levels of TP53INP1 expression in human neuroblastoma tissues correlated with high levels of N-Myc expression and poor patient outcome, and the BET bromodomain inhibitors JQ1 and I-BET151 reduced N-Myc expression and reactivated TP53INP1 expression in neuroblastoma cells. These findings identify TP53INP1 repression as an important co-factor for N-Myc oncogenesis, and provide further evidence for the potential application of BET bromodomain inhibitors in the therapy of N-Myc-induced neuroblastoma. PMID:24952595

Shahbazi, Jeyran; Scarlett, Christopher J; Norris, Murray D; Liu, Bing; Haber, Michelle; Tee, Andrew E; Carrier, Alice; Biankin, Andrew V; London, Wendy B; Marshall, Glenn M; Lock, Richard B; Liu, Tao

2014-06-30

265

Conversion of Helicobacter pylori CagA from senescence inducer to oncogenic driver through polarity-dependent regulation of p21  

PubMed Central

The Helicobacter pylori CagA bacterial oncoprotein plays a critical role in gastric carcinogenesis. Upon delivery into epithelial cells, CagA causes loss of polarity and activates aberrant Erk signaling. We show that CagA-induced Erk activation results in senescence and mitogenesis in nonpolarized and polarized epithelial cells, respectively. In nonpolarized epithelial cells, Erk activation results in oncogenic stress, up-regulation of the p21Waf1/Cip1 cyclin-dependent kinase inhibitor, and induction of senescence. In polarized epithelial cells, CagA-driven Erk signals prevent p21Waf1/Cip1 expression by activating a guanine nucleotide exchange factor–H1–RhoA–RhoA-associated kinase–c-Myc pathway. The microRNAs miR-17 and miR-20a, induced by c-Myc, are needed to suppress p21Waf1/Cip1 expression. CagA also drives an epithelial-mesenchymal transition in polarized epithelial cells. These findings suggest that CagA exploits a polarity-signaling pathway to induce oncogenesis. PMID:20855497

Saito, Yasuhiro; Murata-Kamiya, Naoko; Hirayama, Toshiya; Ohba, Yusuke

2010-01-01

266

B-Raf Inhibitors Induce Epithelial Differentiation in BRAF-Mutant Colorectal Cancer Cells.  

PubMed

BRAF mutations are associated with aggressive, less-differentiated and therapy-resistant colorectal carcinoma. However, the underlying mechanisms for these correlations remain unknown. To understand how oncogenic B-Raf contributes to carcinogenesis, in particular to aspects other than cellular proliferation and survival, we generated three isogenic human colorectal carcinoma cell line models in which we can dynamically modulate the expression of the B-Raf(V600E) oncoprotein. Doxycyclin-inducible knockdown of endogenous B-Raf(V600E) decreases cellular motility and invasion in conventional and three-dimensional (3D) culture, whereas it promotes cell-cell contacts and induces various hallmarks of differentiated epithelia. Importantly, all these effects are recapitulated by B-Raf (PLX4720, vemurafenib, and dabrafenib) or MEK inhibitors (trametinib). Surprisingly, loss of B-Raf(V600E) in HT29 xenografts does not only stall tumor growth, but also induces glandular structures with marked expression of CDX2, a tumor-suppressor and master transcription factor of intestinal differentiation. By performing the first transcriptome profiles of PLX4720-treated 3D cultures of HT29 and Colo-205 cells, we identify several upregulated genes linked to epithelial differentiation and effector functions, such as claudin-1, a Cdx-2 target gene encoding a critical tight junction component. Thereby, we provide a mechanism for the clinically observed correlation between mutant BRAF and the loss of Cdx-2 and claudin-1. PLX4720 also suppressed several metastasis-associated transcripts that have not been implicated as targets, effectors or potential biomarkers of oncogenic B-Raf signaling so far. Together, we identify a novel facet of clinically applied B-Raf or MEK inhibitors by showing that they promote cellular adhesion and differentiation of colorectal carcinoma cells. Cancer Res; 75(1); 216-29. ©2014 AACR. PMID:25381152

Herr, Ricarda; Köhler, Martin; Andrlová, Hana; Weinberg, Florian; Möller, Yvonne; Halbach, Sebastian; Lutz, Lisa; Mastroianni, Justin; Klose, Martin; Bittermann, Nicola; Kowar, Silke; Zeiser, Robert; Olayioye, Monilola A; Lassmann, Silke; Busch, Hauke; Boerries, Melanie; Brummer, Tilman

2015-01-01

267

Human papillomavirus 16 E5 induces bi-nucleated cell formation by cell-cell fusion  

SciTech Connect

Human papillomaviruses (HPV) 16 is a DNA virus encoding three oncogenes - E5, E6, and E7. The E6 and E7 proteins have well-established roles as inhibitors of tumor suppression, but the contribution of E5 to malignant transformation is controversial. Using spontaneously immortalized human keratinocytes (HaCaT cells), we demonstrate that expression of HPV16 E5 is necessary and sufficient for the formation of bi-nucleated cells, a common characteristic of precancerous cervical lesions. Expression of E5 from non-carcinogenic HPV6b does not produce bi-nucleate cells. Video microscopy and biochemical analyses reveal that bi-nucleates arise through cell-cell fusion. Although most E5-induced bi-nucleates fail to propagate, co-expression of HPV16 E6/E7 enhances the proliferation of these cells. Expression of HPV16 E6/E7 also increases bi-nucleated cell colony formation. These findings identify a new role for HPV16 E5 and support a model in which complementary roles of the HPV16 oncogenes lead to the induction of carcinogenesis.

Hu Lulin; Plafker, Kendra [Department of Cell Biology, University of Oklahoma (United States); Vorozhko, Valeriya [Department of Cell Biology, University of Oklahoma (United States); Cell Cycle and Cancer Biology Research Program, Oklahoma Medical Research Foundation (United States); Zuna, Rosemary E. [Department of Pathology, University of Oklahoma HSC (United States); Hanigan, Marie H. [Department of Cell Biology, University of Oklahoma (United States); Gorbsky, Gary J. [Department of Cell Biology, University of Oklahoma (United States); Cell Cycle and Cancer Biology Research Program, Oklahoma Medical Research Foundation (United States); Plafker, Scott M. [Department of Cell Biology, University of Oklahoma (United States); Angeletti, Peter C. [Nebraska Center for Virology (United States); Ceresa, Brian P. [Department of Cell Biology, University of Oklahoma (United States)], E-mail: brian-ceresa@oushc.edu

2009-02-05

268

Chromogenic In Situ Hybridization and p16/Ki67 Dual Staining on Formalin-Fixed Paraffin-Embedded Cervical Specimens: Correlation with HPV-DNA Test, E6/E7 mRNA Test, and Potential Clinical Applications  

PubMed Central

Although HPV-DNA test and E6/E7 mRNA analyses remain the current standard for the confirmation of human papillomavirus (HPV) infections in cytological specimens, no universally adopted techniques exist for the detection of HPV in formalin-fixed paraffin-embedded samples. Particularly, in routine laboratories, molecular assays are still time-consuming and would require a high level of expertise. In this study, we investigated the possible use of a novel HPV tyramide-based chromogenic in situ hybridization (CISH) technology to locate HPV on tissue specimens. Then, we evaluate the potential usefulness of p16INK4a/Ki-67 double stain on histological samples, to identify cervical cells expressing HPV E6/E7 oncogenes. In our series, CISH showed a clear signal in 95.2% of the specimens and reached a sensitivity of 86.5%. CISH positivity always matched with HPV-DNA positivity, while 100% of cases with punctated signal joined with cervical intraepithelial neoplasia grade 2 or worse (CIN2+). p16/Ki67 immunohistochemistry gave an interpretable result in 100% of the cases. The use of dual stain significantly increased the agreement between pathologists, which reached 100%. Concordance between dual stain and E6/E7 mRNA test was 89%. In our series, both CISH and p16INK4a/Ki67 dual stain demonstrated high grade of performances. In particular, CISH would help to distinguish episomal from integrated HPV, in order to allow conclusions regarding the prognosis of the lesion, while p16INK4a/Ki67 dual stain approach would confer a high level of standardization to the diagnostic procedure. PMID:24369532

Zappacosta, Roberta; Colasante, Antonella; Viola, Patrizia; D'Antuono, Tommaso; Lattanzio, Giuseppe; Capanna, Serena; Gatta, Daniela Maria Pia; Rosini, Sandra

2013-01-01

269

Rate constants for the gas-phase reactions of OH radicals with E-7-tetradecene, 2-methyl-1-tridecene and the C(7)-C(14) 1-alkenes at 295 +/- 1 K.  

PubMed

Rate constants for the gas-phase reactions of OH radicals with the C(7)-C(14) 1-alkenes and with E-7-tetradecene and 2-methyl-1-tridecene have been measured at 295 +/- 1 K and atmospheric pressure of air using a relative rate technique. The rate constants obtained (in units of 10(-11) cm(3) molecule(-1) s(-1)) were: 1-heptene, 3.86 +/- 0.12; 1-octene, 4.14 +/- 0.08; 1-nonene, 4.32 +/- 0.05; 1-decene, 4.61 +/- 0.14; 1-undecene, 4.79 +/- 0.11; 1-dodecene, 5.03 +/- 0.13; 1-tridecene, 5.09 +/- 0.17; 1-tetradecene, 4.96 +/- 0.28; E-7-tetradecene, 7.47 +/- 0.53; and 2-methyl-1-tridecene, 8.69 +/- 0.27, where the indicated errors are two least-squares standard deviations and do not include the uncertainty associated with the rate constant for the reference compound alpha-pinene. While our rate constants for 1-octene and 1-nonene agree with those at 298 K recently measured using an absolute rate method, our rate constants for 1-decene and 1-undecene are lower by factors of 1.5 and 2.6, respectively. Combined with previous rate constants from this laboratory for the C(4)-C(7) 1-alkenes, our data show that the rate constants for the reactions of OH radicals with 1-alkenes increase linearly with increasing carbon number, with the increase per additional CH(2) group being a factor of approximately 1.4-1.5 higher than that observed in the n-alkane series. The rate constants measured for E-7-tetradecene and 2-methyl-1-tridecene suggest that the increase in rate constant per additional CH(2) group ranges from being similar to that in the n-alkanes series to being a factor of approximately 2 higher. PMID:18612520

Aschmann, Sara M; Atkinson, Roger

2008-07-28

270

Induced Probabilities.  

ERIC Educational Resources Information Center

Induced probabilities have been largely ignored by educational researchers. Simply stated, if a new or random variable is defined in terms of a first random variable, then induced probability is the probability or density of the new random variable that can be found by summation or integration over the appropriate domains of the original random…

Neel, John H.

271

Photodynamic therapy with recombinant adenovirus AdmIL-12 enhances anti-tumour therapy efficacy in human papillomavirus 16 (E6/E7) infected tumour model  

PubMed Central

Immunotherapy with photodynamic therapy (PDT) offers great promise as a new alternative for cancer treatment; however, its use remains experimental. Here we investigated the utility of adenoviral delivery of interleukin-12 (AdmIL-12) as an adjuvant for PDT in mouse tumour challenge model. PDT was performed by irradiating Radachlorin in C57BL/6 mice transplanted with TC-1 cells. PDT plus AdmIL-12 treatment for tumour suppression as well as specific immune responses were evaluated with the following tests: in vitro and in vivo tumour growth inhibition, interferon-? (IFN-?) and tumour necrosis factor-? (TNF-?) assay, and cytotoxic T lymphocyte (CTL) assay. Direct intratumoral injection of AdmIL-12 resulted in a significant suppression of tumour growth compared to the control group. Treatment of PDT along with AdmIL-12 further enhanced antitumour effects significantly higher than either AdmIL-12 or PDT alone. This combined treatment resulted in complete regression of 9-mm sized tumour in every animal. We also evaluated immune responses induced by these treatments. Combined treatment significantly increased the production level of IFN-? and TNF-? compared with that by AdmIL-12 or PDT alone. PDT plus AdmIL-12 enhanced antitumour immunity through increased expansion of the CTL subset mediated by CD8+ T cells. Taken together, these results indicate that the high anti-cancer activity of PDT with AdmIL-12 is a powerful tool against cancer therapy and is a promising subject for further investigation. PMID:18397271

Park, Eun Kyung; Bae, Su-Mi; Kwak, Sun-Young; Lee, Sung Jong; Kim, Yong-Wook; Han, Chan-Hee; Cho, Hyun-Jung; Kim, Kyung Tae; Kim, Young-Jae; Kim, Hyun-Jung; Ahn, Woong Shick

2008-01-01

272

NF-M (chicken C/EBP beta) induces eosinophilic differentiation and apoptosis in a hematopoietic progenitor cell line.  

PubMed Central

CAAT/enhancer binding proteins (C/EBPs) are transcriptional activators implicated in the differentiation processes of various cell lineages. We have shown earlier that NF-M, the chicken homolog of C/EBP beta, is specifically expressed in myelomonocytic and eosinophilic cells of the hematopoietic system. To investigate the role of NF-M in hematopoietic cell lineage commitment, we constructed a conditional form of the protein by fusing it to the hormone binding domain of the human estrogen receptor. This construct was stably expressed in a multipotent progenitor cell line transformed by the Myb-Ets oncoprotein. We report here that both NF-M-dependent promoter constructs and resident genes could be activated by addition of beta-estradiol to the NF-M-estrogen receptor expressing progenitors. At the same time, we observed a down-regulation of progenitor-specific surface markers and the up-regulation of differentiation markers restricted to the eosinophil and myeloid lineages. In addition to the onset of differentiation, cell death was induced with typical apoptotic features. Our results suggest that NF-M plays an important role in commitment along the eosinophil lineage and in the induction of apoptosis. Images PMID:8557032

Müller, C; Kowenz-Leutz, E; Grieser-Ade, S; Graf, T; Leutz, A

1995-01-01

273

Fulvestrant-Induced Cell Death and Proteasomal Degradation of Estrogen Receptor ? Protein in MCF-7 Cells Require the CSK c-Src Tyrosine Kinase  

PubMed Central

Fulvestrant is a representative pure antiestrogen and a Selective Estrogen Receptor Down-regulator (SERD). In contrast to the Selective Estrogen Receptor Modulators (SERMs) such as 4-hydroxytamoxifen that bind to estrogen receptor ? (ER?) as antagonists or partial agonists, fulvestrant causes proteasomal degradation of ER? protein, shutting down the estrogen signaling to induce proliferation arrest and apoptosis of estrogen-dependent breast cancer cells. We performed genome-wide RNAi knockdown screenings for protein kinases required for fulvestrant-induced apoptosis of the MCF-7 estrogen-dependent human breast caner cells and identified the c-Src tyrosine kinase (CSK), a negative regulator of the oncoprotein c-Src and related protein tyrosine kinases, as one of the necessary molecules. Whereas RNAi knockdown of CSK in MCF-7 cells by shRNA-expressing lentiviruses strongly suppressed fulvestrant-induced cell death, CSK knockdown did not affect cytocidal actions of 4-hydroxytamoxifen or paclitaxel, a chemotherapeutic agent. In the absence of CSK, fulvestrant-induced proteasomal degradation of ER? protein was suppressed in both MCF-7 and T47D estrogen-dependent breast cancer cells whereas the TP53-mutated T47D cells were resistant to the cytocidal action of fulvestrant in the presence or absence of CSK. MCF-7 cell sensitivities to fulvestrant-induced cell death or ER? protein degradation was not affected by small-molecular-weight inhibitors of the tyrosine kinase activity of c-Src, suggesting possible involvement of other signaling molecules in CSK-dependent MCF-7 cell death induced by fulvestrant. Our observations suggest the importance of CSK in the determination of cellular sensitivity to the cytocidal action of fulvestrant. PMID:23593342

Yeh, Wei-Lan; Shioda, Keiko; Coser, Kathryn R.; Rivizzigno, Danielle; McSweeney, Kristen R.; Shioda, Toshi

2013-01-01

274

The polycomb group protein Bmi-1 represses the tumor suppressor PTEN and induces epithelial-mesenchymal transition in human nasopharyngeal epithelial cells.  

PubMed

The polycomb group protein B lymphoma Mo-MLV insertion region 1 homolog (Bmi-1) is dysregulated in various cancers, and its upregulation strongly correlates with an invasive phenotype and poor prognosis in patients with nasopharyngeal carcinomas. However, the underlying mechanism of Bmi-1-mediated invasiveness remains unknown. In the current study, we found that upregulation of Bmi-1 induced epithelial-mesenchymal transition (EMT) and enhanced the motility and invasiveness of human nasopharyngeal epithelial cells, whereas silencing endogenous Bmi-1 expression reversed EMT and reduced motility. Furthermore, upregulation of Bmi-1 led to the stabilization of Snail, a transcriptional repressor associated with EMT, via modulation of PI3K/Akt/GSK-3beta signaling. Chromatin immunoprecipitation assays revealed that Bmi-1 transcriptionally downregulated expression of the tumor suppressor PTEN in tumor cells through direct association with the PTEN locus. This in vitro analysis was consistent with the statistical inverse correlation detected between Bmi-1 and PTEN expression in a cohort of human nasopharyngeal carcinoma biopsies. Moreover, ablation of PTEN expression partially rescued the migratory/invasive phenotype of Bmi-1-silenced cells, indicating that PTEN might be a major mediator of Bmi-1-induced EMT. Our results provide functional and mechanistic links between the oncoprotein Bmi-1 and the tumor suppressor PTEN in the development and progression of cancer. PMID:19884659

Song, Li-Bing; Li, Jun; Liao, Wen-Ting; Feng, Yan; Yu, Chun-Ping; Hu, Li-Juan; Kong, Qing-Li; Xu, Li-Hua; Zhang, Xing; Liu, Wan-Li; Li, Man-Zhi; Zhang, Ling; Kang, Tie-Bang; Fu, Li-Wu; Huang, Wen-Lin; Xia, Yun-Fei; Tsao, Sai Wah; Li, Mengfeng; Band, Vimla; Band, Hamid; Shi, Qing-Hua; Zeng, Yi-Xin; Zeng, Mu-Sheng

2009-12-01

275

L-amino acid oxidase isolated from Bothrops pirajai induces apoptosis in BCR-ABL-positive cells and potentiates imatinib mesylate effect.  

PubMed

Chronic myeloid leukaemia (CML) is a myeloproliferative disorder characterized by the presence of Philadelphia chromosome and by BCR-ABL1, which encodes the BCR-ABL oncoprotein. Although imatinib mesylate (IM) is effective for CML treatment, patients in accelerated and blastic phases of the disease are often refractory to this therapy, and there are also cases of IM resistance in patients in the chronic phase. Therefore, potential new drugs are being investigated to improve the efficiency of the therapy of CML such as snake venoms and their compounds. In this investigation, Bothrops pirajai L-amino acid oxidase (BpirLAAO-I) effect on normal peripheral blood mononuclear cells (PBMC) and on BCR-ABL(+) cell line was assessed to explore its potential against leukaemic cells. MTT viability assay, lymphocyte subsets quantification and cell activation markers expression were performed to evaluate BpirLAAO-I effect on normal PBMC. The effect of BpirLAAO-I on HL-60 and HL-60.BCR-ABL cell lines was assessed by apoptosis detection. BpirLAAO-I was able to induce apoptosis in HL-60 and HL-60.BCR-ABL cell lines in a dose-dependent manner, promoted caspases 3, 8 and 9 activation and enhanced IM effect while not affecting the viability of normal cells. In addition, BpirLAAO-I promoted immune cells activation and lymphocytes subsets changes on normal PBMC. The results indicate that BpirLAAO-I induces apoptosis and potentiates IM effect on BCR-ABL(+) cells. PMID:23551499

Burin, Sandra M; Ayres, Lorena R; Neves, Renata P; Ambrósio, Luciana; de Morais, Fabiana R; Dias-Baruffi, Marcelo; Sampaio, Suely V; Pereira-Crott, Luciana S; de Castro, Fabíola A

2013-08-01

276

[Induced acne].  

PubMed

Induced acne belongs to the clinical forms of acne. Some dermatoses present with acne-like patterns. They can be induced or perpetuated by non physiological factors. Among these factors, medicines must always be considered, taken either topically (dermocorticoids, sulfur, anti-acneic topics) or generally (androgens, oral corticoids, ACTH, anti-epileptics, anti-depressive drugs, anti-tuberculosis medications). Halogens (iodine, bromine) found in inhaled or orally taken pharmaceutical products, or associated with occupational contact, can also induce acne. Acne of exogenous origin has been described in some specific occupations, and are induced by exposure to chlorine, industrial oils, tar. Sun exposure, PUVA therapy and ionizing radiation are potentially acneigenous. Finally acne caused by cosmetics includes acne cosmetica, brilliantine and oily creams acne and detergent acne. PMID:12053790

Humbert, Philippe

2002-04-15

277

Human papillomavirus causes an angiogenic switch in keratinocytes which is sufficient to alter endothelial cell behavior  

SciTech Connect

One of the requirements for tumor growth is the ability to recruit a blood supply, a process known as angiogenesis. Angiogenesis begins early in the progression of cervical disease from mild to severe dysplasia and on to invasive cancer. We have previously reported that expression of human papillomavirus type 16 E6 and E7 (HPV16 E6E7) proteins in primary foreskin keratinocytes (HFKs) decreases expression of two inhibitors and increases expression of two angiogenic inducers [Toussaint-Smith, E., Donner, D.B., Roman, A., 2004. Expression of human papillomavirus type 16 E6 and E7 oncoproteins in primary foreskin keratinocytes is sufficient to alter the expression of angiogenic factors. Oncogene 23, 2988-2995]. Here we report that HPV-induced early changes in the keratinocyte phenotype are sufficient to alter endothelial cell behavior both in vitro and in vivo. Conditioned media from HPV16 E6E7 expressing HFKs as well as from human cervical keratinocytes containing the intact HPV16 were able to stimulate proliferation and migration of human microvascular endothelial cells. In addition, introduction of the conditioned media into immunocompetent mice using a Matrigel plug model resulted in a clear angiogenic response. These novel data support the hypothesis that HPV proteins contribute not only to the uncontrolled keratinocyte growth seen following HPV infection but also to the angiogenic response needed for tumor formation.

Chen, W. [Department of Microbiology and Immunology and the Walther Oncology Center, Indiana University School of Medicine and the Walther Cancer Institute, Indianapolis, 635 Barnhill Drive, Indianapolis, IN 46202-5120 (United States); Li, F.; Mead, L.; White, H. [Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202 (United States); Walker, J. [Department of Microbiology and Immunology and the Walther Oncology Center, Indiana University School of Medicine and the Walther Cancer Institute, Indianapolis, 635 Barnhill Drive, Indianapolis, IN 46202-5120 (United States); Ingram, D.A. [Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202 (United States); Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202 (United States); Roman, A. [Department of Microbiology and Immunology and the Walther Oncology Center, Indiana University School of Medicine and the Walther Cancer Institute, Indianapolis, 635 Barnhill Drive, Indianapolis, IN 46202-5120 (United States)], E-mail: aroman@iupui.edu

2007-10-10

278

Sulforaphane down-regulates SKP2 to stabilize p27(KIP1) for inducing antiproliferation in human colon adenocarcinoma cells.  

PubMed

Sulforaphane is a cruciferous vegetable-derived isothiocyanate with promising chemopreventive and therapeutic activities. Induction of proliferation arrest and apoptosis principally contribute to sulforaphane's anticancer activity, but the precise molecular mechanisms remain elusive. The oncoprotein SKP2 is a key component of the SKP1-CULLIN1-F-box (SCF) E3 ligase complex and is responsible for directing SCF-mediated degradation of cyclin-dependent kinase inhibitor p27(KIP1) to promote cell proliferation. We herein provide the first evidence supporting the critical involvement of the SKP2-p27(KIP1) axis in sulforaphane-induced antiproliferation in various human colon adenocarcinoma cell lines. Specifically, sulforaphane markedly suppressed the levels of bromodeoxyuridine (BrdU) incorporation and clonogenicity in all tested cell lines, illustrating the antiproliferative effect of sulforaphane. Of note, sulforaphane-induced antiproliferation was accompanied with down-regulation of SKP2, leading to the stabilization and thus up-regulation of p27(KIP1). Additionally, sulforaphane was found to down-regulate SKP2 mainly through transcriptional repression, as sulforaphane lowered SKP2 mRNA expression and the SKP2 promoter activity. Furthermore, sulforaphane treatment led to the activation of both AKT and ERK, thus ruling out the possibility that sulforaphane down-regulates SKP2 by inhibiting AKT or ERK. Notably, sulforaphane-elicited suppression of BrdU incorporation and clonogenicity were significantly rescued in the context of SKP2 overexpression or p27(KIP1) depletion, therefore highlighting the important role of SKP2 down-regulation and the ensuing stabilization of p27(KIP1) in sulforaphane-induced antiproliferation. Collectively, these data expand our molecular understanding about how sulforaphane elicits proliferation arrest, but also implicate the application of sulforaphane in therapeutic modalities targeting SKP2. PMID:25070589

Chung, Yuan-Kai; Chi-Hung Or, Richard; Lu, Chien-Hsing; Ouyang, Wei-Ting; Yang, Shu-Yi; Chang, Chia-Che

2015-01-01

279

High-risk human papillomavirus E6/E7 mRNA detection by a novel in situ hybridization assay strongly correlates with p16 expression and patient outcomes in oropharyngeal squamous cell carcinoma.  

PubMed

Human papillomavirus (HPV) is established as causative in oropharyngeal squamous cell carcinomas (OSCCs), being detected in 50% to 80% of tumors by DNA in situ hybridization (ISH) and/or polymerase chain reaction. However, these tests do not assess viral transcription. Many consider E6/E7 messenger ribonucleic acid (mRNA) the best indicator of HPV status, but it has not been detected in situ in OSCC. We constructed tissue microarrays (TMAs) from a cohort of OSCC for which p16 immunohistochemistry and HPV DNA ISH were previously performed on whole sections. We utilized a novel, chromogenic RNA ISH assay called RNAscope to detect E6/E7 mRNA of HPV-16 and other high-risk types on these TMAs. RNA ISH results were obtained for 196 of 211 TMA cases, of which 153 (78.1%) were positive. p16 immunohistochemistry and HPV DNA ISH were positive in 79.0% and 62.4% of cases, respectively. Concordance between RNA and p16, DNA and p16, and RNA and DNA were 96.4%, 78.7%, and 83.5%, respectively. Only 7 cases (3.6%) were discrepant between RNA ISH and p16. In univariate analysis, all 3 tests correlated with better overall survival (OS), disease-specific survival (DSS), and disease-free survival (DFS) (all P<0.001). In multivariate analysis, OS correlated significantly with RNA (hazard ratio=0.39, P=0.001), DNA (0.53, P=0.03), and p16 (0.30, P<0.001), but DSS and DFS correlated significantly only with p16 (DSS: 0.36, P=0.006; DFS: 0.42, P=0.016). RNA ISH is more sensitive than DNA ISH in detecting HPV in OSCC, and it correlates strongly with p16. Although both tests were comparable, p16 more strongly stratified patient outcomes. PMID:21836494

Ukpo, Odey C; Flanagan, John J; Ma, Xiao-Jun; Luo, Yuling; Thorstad, Wade L; Lewis, James S

2011-09-01

280

Transcription factor PREP1 induces EMT and metastasis by controlling the TGF-?-SMAD3 pathway in non-small cell lung adenocarcinoma.  

PubMed

Pre-B-cell leukemia homeobox (Pbx)-regulating protein-1 (Prep1) is a ubiquitous homeoprotein involved in early development, genomic stability, insulin sensitivity, and hematopoiesis. Previously we have shown that Prep1 is a haploinsufficient tumor suppressor that inhibits neoplastic transformation by competing with myeloid ecotropic integration site 1 for binding to the common heterodimeric partner Pbx1. Epithelial-mesenchymal transition (EMT) is controlled by complex networks of proinvasive transcription factors responsive to paracrine factors such as TGF-?. Here we show that, in addition to inhibiting primary tumor growth, PREP1 is a novel EMT inducer and prometastatic transcription factor. In human non-small cell lung cancer (NSCLC) cells, PREP1 overexpression is sufficient to trigger EMT, whereas PREP1 down-regulation inhibits the induction of EMT in response to TGF-?. PREP1 modulates the cellular sensitivity to TGF-? by inducing the small mothers against decapentaplegic homolog 3 (SMAD3) nuclear translocation through mechanisms dependent, at least in part, on PREP1-mediated transactivation of a regulatory element in the SMAD3 first intron. Along with the stabilization and accumulation of PBX1, PREP1 induces the expression of multiple activator protein 1 components including the proinvasive Fos-related antigen 1 (FRA-1) oncoprotein. Both FRA-1 and PBX1 are required for the mesenchymal changes triggered by PREP1 in lung tumor cells. Finally, we show that the PREP1-induced mesenchymal transformation correlates with significantly increased lung colonization by cells overexpressing PREP1. Accordingly, we have detected PREP1 accumulation in a large number of human brain metastases of various solid tumors, including NSCLC. These findings point to a novel role of the PREP1 homeoprotein in the control of the TGF-? pathway, EMT, and metastasis in NSCLC. PMID:25157139

Risolino, Maurizio; Mandia, Nadia; Iavarone, Francescopaolo; Dardaei, Leila; Longobardi, Elena; Fernandez, Serena; Talotta, Francesco; Bianchi, Fabrizio; Pisati, Federica; Spaggiari, Lorenzo; Harter, Patrick N; Mittelbronn, Michel; Schulte, Dorothea; Incoronato, Mariarosaria; Di Fiore, Pier Paolo; Blasi, Francesco; Verde, Pasquale

2014-09-01

281

Activating c-KIT mutations confer oncogenic cooperativity and rescue RUNX1/ETO-induced DNA damage and apoptosis in human primary CD34+ hematopoietic progenitors  

PubMed Central

The RUNX1/ETO (RE) fusion protein, which originates from the t(8;21) chromosomal rearrangement, is one of the most frequent translocation products found in de novo acute myeloid leukemia (AML). In RE leukemias, activated forms of the c-KIT tyrosine kinase receptor are frequently found, thereby suggesting oncogenic cooperativity between these oncoproteins in the development and maintenance of t(8;21) malignancies. In this report, we show that activated c-KIT cooperates with a C-terminal truncated variant of RE, REtr, to expand human CD34+ hematopoietic progenitors ex vivo. CD34+ cells expressing both oncogenes resemble the AML-M2 myeloblastic cell phenotype, in contrast to REtr-expressing cells which largely undergo granulocytic differentiation. Oncogenic c-KIT amplifies REtr-depended clonogenic growth and protects cells from exhaustion. Activated c-KIT reverts REtr-induced DNA damage and apoptosis. In the presence of activated c-KIT, REtr-downregulated DNA-repair genes are re-expressed leading to an enhancement of DNA-repair efficiency via homologous recombination. Together, our results provide new mechanistic insight into REtr and c-KIT oncogenic cooperativity and suggest that augmented DNA repair accounts for the increased chemoresistance observed in t(8;21)-positive AML patients with activated c-KIT mutations. This cell-protective mechanism might represent a new therapeutic target, as REtr cells with activated c-KIT are highly sensitive to pharmacological inhibitors of DNA repair. PMID:24897507

Wichmann, C; Quagliano-Lo Coco, I; Yildiz, Ö; Chen-Wichmann, L; Weber, H; Syzonenko, T; Döring, C; Brendel, C; Ponnusamy, K; Kinner, A; Brandts, C; Henschler, R; Grez, M

2015-01-01

282

Mechanisms of Cisplatin-Induced Apoptosis and of Cisplatin Sensitivity: Potential of BIN1 to Act as a Potent Predictor of Cisplatin Sensitivity in Gastric Cancer Treatment  

PubMed Central

Cisplatin is the most important and efficacious chemotherapeutic agent for the treatment of advanced gastric cancer. Cisplatin forms inter- and intrastrand crosslinked DNA adducts and its cytotoxicity is mediated by propagation of DNA damage recognition signals to downstream pathways involving ATR, p53, p73, and mitogen-activated protein kinases, ultimately resulting in apoptosis. Cisplatin resistance arises through a multifactorial mechanism involving reduced drug uptake, increased drug inactivation, increased DNA damage repair, and inhibition of transmission of DNA damage recognition signals to the apoptotic pathway. In addition, a new mechanism has recently been revealed, in which the oncoprotein c-Myc suppresses bridging integrator 1 (BIN1), thereby releasing poly(ADP-ribose)polymerase 1, which results in increased DNA repair activity and allows cancer cells to acquire cisplatin resistance. The present paper focuses on the molecular mechanisms of cisplatin-induced apoptosis and of cisplatin resistance, in particular on the involvement of BIN1 in the maintenance of cisplatin sensitivity. PMID:22778941

Tanida, Satoshi; Mizoshita, Tsutomu; Ozeki, Keiji; Tsukamoto, Hironobu; Kamiya, Takeshi; Kataoka, Hiromi; Sakamuro, Daitoku; Joh, Takashi

2012-01-01

283

Chronic cadmium exposure in vitro induces cancer cell characteristics in human lung cells  

PubMed Central

Cadmium is a known human lung carcinogen. Here, we attempt to develop an in vitro model of cadmium-induced human lung carcinogenesis by chronically exposing the peripheral lung epithelia cell line, HPL-1D, to a low level of cadmium. Cells were chronically exposed to 5 ?M cadmium, a noncytotoxic level, and monitored for acquired cancer characteristics. By 20 weeks of continuous cadmium exposure, these chronic cadmium treated lung (CCT-LC) cells showed marked increases in secreted MMP-2 activity (3.5-fold), invasion (3.4-fold), and colony formation in soft agar (2-fold). CCT-LC cells were hyperproliferative, grew well in serum-free media, and overexpressed cyclin D1. The CCT-LC cells also showed decreased expression of the tumor suppressor genes p16 and SLC38A3 at the protein levels. Also consistent with an acquired cancer cell phenotype, CCT-LC cells showed increased expression of the oncoproteins K-RAS and N-RAS as well as the epithelial-to-mesenchymal transition marker protein Vimentin. Metallothionein (MT) expression is increased by cadmium, and is typically overexpressed in human lung cancers. The major MT isoforms, MT-1A and MT-2A were elevated in CCT-LC cells. Oxidant adaptive response genes HO-1 and HIF-1A were also activated in CCT-LC cells. Expression of the metal transport genes ZNT-1, ZNT-5, and ZIP-8 increased in CCT-LC cells culminating in reduced cadmium accumulation, suggesting adaptation to the metal. Overall, these data suggest that exposure of human lung epithelial cells to cadmium causes acquisition of cancer cell characteristics. Furthermore, transformation occurs despite the cell’s ability to adapt to chronic cadmium exposure. PMID:23811327

Person, Rachel J.; Tokar, Erik J.; Xu, Yuanyuan; Orihuela, Ruben; Olive Ngalame, Ntube N.; Waalkes, Michael P.

2013-01-01

284

Chronic cadmium exposure in vitro induces cancer cell characteristics in human lung cells.  

PubMed

Cadmium is a known human lung carcinogen. Here, we attempt to develop an in vitro model of cadmium-induced human lung carcinogenesis by chronically exposing the peripheral lung epithelia cell line, HPL-1D, to a low level of cadmium. Cells were chronically exposed to 5 ?M cadmium, a noncytotoxic level, and monitored for acquired cancer characteristics. By 20 weeks of continuous cadmium exposure, these chronic cadmium treated lung (CCT-LC) cells showed marked increases in secreted MMP-2 activity (3.5-fold), invasion (3.4-fold), and colony formation in soft agar (2-fold). CCT-LC cells were hyperproliferative, grew well in serum-free media, and overexpressed cyclin D1. The CCT-LC cells also showed decreased expression of the tumor suppressor genes p16 and SLC38A3 at the protein levels. Also consistent with an acquired cancer cell phenotype, CCT-LC cells showed increased expression of the oncoproteins K-RAS and N-RAS as well as the epithelial-to-mesenchymal transition marker protein Vimentin. Metallothionein (MT) expression is increased by cadmium, and is typically overexpressed in human lung cancers. The major MT isoforms, MT-1A and MT-2A were elevated in CCT-LC cells. Oxidant adaptive response genes HO-1 and HIF-1A were also activated in CCT-LC cells. Expression of the metal transport genes ZNT-1, ZNT-5, and ZIP-8 increased in CCT-LC cells culminating in reduced cadmium accumulation, suggesting adaptation to the metal. Overall, these data suggest that exposure of human lung epithelial cells to cadmium causes acquisition of cancer cell characteristics. Furthermore, transformation occurs despite the cell's ability to adapt to chronic cadmium exposure. PMID:23811327

Person, Rachel J; Tokar, Erik J; Xu, Yuanyuan; Orihuela, Ruben; Ngalame, Ntube N Olive; Waalkes, Michael P

2013-12-01

285

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

PubMed

Blocking the oncoprotein murine double minute 2 (MDM2)-p53 protein-protein interaction has long been considered to offer a broad cancer therapeutic strategy, despite the potential risks of selecting tumors harboring p53 mutations that escape MDM2 control. In this study, we report a novel small-molecule inhibitor of the MDM2-p53 interaction, SAR405838 (MI-77301), that has been advanced into phase I clinical trials. SAR405838 binds to MDM2 with K(i) = 0.88 nmol/L and has high specificity over other proteins. A cocrystal structure of the SAR405838:MDM2 complex shows that, in addition to mimicking three key p53 amino acid residues, the inhibitor captures additional interactions not observed in the p53-MDM2 complex and induces refolding of the short, unstructured MDM2 N-terminal region to achieve its high affinity. SAR405838 effectively activates wild-type p53 in vitro and in xenograft tumor tissue of leukemia and solid tumors, leading to p53-dependent cell-cycle arrest and/or apoptosis. At well-tolerated dose schedules, SAR405838 achieves either durable tumor regression or complete tumor growth inhibition in mouse xenograft models of SJSA-1 osteosarcoma, RS4;11 acute leukemia, LNCaP prostate cancer, and HCT-116 colon cancer. Remarkably, a single oral dose of SAR405838 is sufficient to achieve complete tumor regression in the SJSA-1 model. Mechanistically, robust transcriptional upregulation of PUMA induced by SAR405838 results in strong apoptosis in tumor tissue, leading to complete tumor regression. Our findings provide a preclinical basis upon which to evaluate SAR405838 as a therapeutic agent in patients whose tumors retain wild-type p53. PMID:25145672

Wang, Shaomeng; Sun, Wei; Zhao, Yujun; McEachern, Donna; Meaux, Isabelle; Barrière, Cédric; Stuckey, Jeanne A; Meagher, Jennifer L; Bai, Longchuan; Liu, Liu; Hoffman-Luca, Cassandra Gianna; Lu, Jianfeng; Shangary, Sanjeev; Yu, Shanghai; Bernard, Denzil; Aguilar, Angelo; Dos-Santos, Odette; Besret, Laurent; Guerif, Stéphane; Pannier, Pascal; Gorge-Bernat, Dimitri; Debussche, Laurent

2014-10-15

286

Serum antibody response to Human papillomavirus (HPV) infections detected by a novel ELISA technique based on denatured recombinant HPV16 L1, L2, E4, E6 and E7 proteins  

PubMed Central

Background Human papillomaviruses (HPVs) are the primary etiological agents of cervical cancer and are also involved in the development of other tumours (skin, head and neck). Serological survey of the HPV infections is important to better elucidate their natural history and to disclose antigen determinants useful for vaccine development. At present, the analysis of the HPV-specific antibodies has not diagnostic value for the viral infections, and new approaches are needed to correlate the antibody response to the disease outcome. The aim of this study is to develop a novel ELISA, based on five denatured recombinant HPV16 proteins, to be used for detection HPV-specific antibodies. Methods The HPV16 L1, L2, E4, E6 and E7 genes were cloned in a prokaryotic expression vector and expressed as histidine-tagged proteins. These proteins, in a denatured form, were used in ELISA as coating antigens. Human sera were collected from women with abnormal PAP smear enrolled during an ongoing multicenter HPV-PathogenISS study in Italy, assessing the HPV-related pathogenetic mechanisms of progression of cervical cancer precursor lesions. Negative human sera were collected from patients affected by other infectious agents. All the HPV-positive sera were also subjected to an avidity test to assess the binding strength in the antigen-antibody complexes. Results Most of the sera showed a positive reactivity to the denatured HPV16 proteins: 82% of the sera from HPV16 infected women and 89% of the sera from women infected by other HPV genotypes recognised at least one of the HPV16 proteins. The percentages of samples showing reactivity to L1, L2 and E7 were similar, but only a few serum samples reacted to E6 and E4. Most sera bound the antigens with medium and high avidity index, suggesting specific antigen-antibody reactions. Conclusion This novel ELISA, based on multiple denatured HPV16 antigens, is able to detect antibodies in women infected by HPV16 and it is not genotype-specific, as it detects antibodies also in women infected by other genital HPVs. The assay is easy to perform and has low cost, making it suitable for monitoring the natural history of HPV infections as well as for detecting pre-existing HPV antibodies in women who receive VLP-based HPV vaccination. PMID:17150135

Di Bonito, Paola; Grasso, Felicia; Mochi, Stefania; Accardi, Luisa; Donà, Maria Gabriella; Branca, Margherita; Costa, Silvano; Mariani, Luciano; Agarossi, Alberto; Ciotti, Marco; Syrjänen, Kari; Giorgi, Colomba

2006-01-01

287

Towards a “Sample-In, Answer-Out” Point-of-Care Platform for Nucleic Acid Extraction and Amplification: Using an HPV E6/E7 mRNA Model System  

PubMed Central

The paper presents the development of a “proof-of-principle” hands-free and self-contained diagnostic platform for detection of human papillomavirus (HPV) E6/E7 mRNA in clinical specimens. The automated platform performs chip-based sample preconcentration, nucleic acid extraction, amplification, and real-time fluorescent detection with minimal user interfacing. It consists of two modular prototypes, one for sample preparation and one for amplification and detection; however, a common interface is available to facilitate later integration into one single module. Nucleic acid extracts (n = 28) from cervical cytology specimens extracted on the sample preparation chip were tested using the PreTect HPV-Proofer and achieved an overall detection rate for HPV across all dilutions of 50%–85.7%. A subset of 6 clinical samples extracted on the sample preparation chip module was chosen for complete validation on the NASBA chip module. For 4 of the samples, a 100% amplification for HPV 16 or 33 was obtained at the 1?:?10 dilution for microfluidic channels that filled correctly. The modules of a “sample-in, answer-out” diagnostic platform have been demonstrated from clinical sample input through sample preparation, amplification and final detection. PMID:22235204

Gulliksen, Anja; Keegan, Helen; Martin, Cara; O'Leary, John; Solli, Lars A.; Falang, Inger Marie; Grønn, Petter; Karlgård, Aina; Mielnik, Michal M.; Johansen, Ib-Rune; Tofteberg, Terje R.; Baier, Tobias; Gransee, Rainer; Drese, Klaus; Hansen-Hagge, Thomas; Riegger, Lutz; Koltay, Peter; Zengerle, Roland; Karlsen, Frank; Ausen, Dag; Furuberg, Liv

2012-01-01

288

CD4+ T Lymphocytes Are Critical Mediators of Tumor Immunity to Simian Virus 40 Large Tumor Antigen Induced by Vaccination with Plasmid DNA ?  

PubMed Central

A mechanistic analysis of tumor immunity directed toward the viral oncoprotein simian virus 40 (SV40) large tumor antigen (Tag) has previously been described by our laboratory for scenarios of recombinant Tag immunization in BALB/c mice. In the present study, we performed a preliminary characterization of the immune components necessary for systemic tumor immunity induced upon immunization with plasmid DNA encoding SV40 Tag as a transgene (pCMV-Tag). Antibody responses to SV40 Tag were observed via indirect enzyme-linked immunosorbent assay following three intramuscular (i.m.) injections of pCMV-Tag and were typified by a mixed Th1/Th2 response. Complete tumor immunity within a murine model of pulmonary metastasis was achieved upon two i.m. injections of pCMV-Tag, as assessed by examination of tumor foci in mouse lungs, without a detectable antibody response to SV40 Tag. Induction-phase and effector-phase depletions of T cell subsets were performed in vivo via administration of depleting rat monoclonal antibodies, and these experiments demonstrated that CD4+ T lymphocytes are required in both phases of the adaptive immune response. Conversely, depletion of CD8+ T lymphocytes did not impair tumor immunity in either immune phase and resulted in the premature production of antibodies to SV40 Tag. Our findings are unique in that a dominant role could be ascribed to CD4+ T lymphocytes within a model of DNA vaccine-induced tumor immunity to Tag-expressing tumor cells. Additionally, our findings provide insight into the general mechanisms of vaccine-induced tumor immunity directed toward tumors bearing distinct tumor-associated antigens. PMID:21593176

Aldrich, Joel F.; Lowe, Devin B.; Shearer, Michael H.; Winn, Richard E.; Jumper, Cynthia A.; Bright, Robert K.; Kennedy, Ronald C.

2011-01-01

289

Spider Mite-Induced (3S)-(E)-Nerolidol Synthase Activity in Cucumber and Lima Bean. The First Dedicated Step in Acyclic C11-Homoterpene Biosynthesis1  

PubMed Central

Many plant species respond to herbivory with de novo production of a mixture of volatiles that attracts carnivorous enemies of the herbivores. One of the major components in the blend of volatiles produced by many different plant species in response to herbivory by insects and spider mites is the homoterpene 4,8-dimethyl-1,3(E),7-nonatriene. One study (J. Donath, W. Boland [1995] Phytochemistry 39: 785–790) demonstrated that a number of plant species can convert the acyclic sesquiterpene alcohol (3S)-(E)-nerolidol to this homoterpene. Cucumber (Cucumis sativus L.) and lima bean (Phaseolus lunatus L.) both produce 4,8-dimethyl-1,3(E),7-nonatriene in response to herbivory. We report the presence in cucumber and lima bean of a sesquiterpene synthase catalyzing the formation of (3S)-(E)-nerolidol from farnesyl diphosphate. The enzyme is inactive in uninfested cucumber leaves, slightly active in uninfested lima bean leaves, and strongly induced by feeding of the two-spotted spider mite (Tetranychus urticae Koch) on both plant species, but not by mechanical wounding. The activities of the (3S)-(E)-nerolidol synthase correlated well with the levels of release of 4,8-dimethyl-1,3(E),7-nonatriene from the leaves of the different treatments. Thus, (3S)-(E)-nerolidol synthase is a good candidate for a regulatory role in the release of the important signaling molecule 4,8-dimethyl-1,3(E),7-nonatriene. PMID:10482672

Bouwmeester, Harro J.; Verstappen, Francel W.A.; Posthumus, Maarten A.; Dicke, Marcel

1999-01-01

290

Human papillomavirus types detected in skin warts and cancer differ in their transforming properties but commonly counteract UVB induced protective responses in human keratinocytes.  

PubMed

In the present study, E6E7 and E6 proteins of human papillomaviruses (HPVs) associated with skin warts and cancer were compared for their transforming and carcinogenic abilities in primary human keratinocytes (PHKs). We show that E6E7 of cancer associated beta HPV types, notably 49 and 24, were able to extend the life span and enhance the clonogenic efficiency of PHKs when maintained in serum free/low calcium medium. Activities of the beta HPV E6E7 were lower than those of HPV16 E6E7. In contrast, E6 proteins from HPV types detected in skin warts or cancer, notably 10, 49 and 38, attenuated UVB induced protective responses in PHKs including cell death, proliferation arrest and accumulation of the proapoptotic proteins, p53, bax or bak. Together, this investigation revealed functional differences and commonalities between HPVs associated with skin warts and cancer, and allowed the identification of specific properties of beta HPVs supporting their involvement in skin carcinogenesis. PMID:25443667

Shterzer, Naama; Heyman, Dariya; Shapiro, Beny; Yaniv, Abraham; Jackman, Anna; Serour, Francis; Chaouat, Malka; Gonen, Pinhas; Tommasino, Massimo; Sherman, Levana

2014-11-01

291

Depletion of the cdk Inhibitor p16INK4a Differentially Affects Proliferation of Established Cervical Carcinoma Cells  

PubMed Central

ABSTRACT Infections with high-risk human papillomaviruses (hrHPV) contribute to cervical carcinoma. The cdk inhibitor and tumor suppressor p16INK4A is consistently upregulated in cervical carcinoma cells for reasons that are poorly understood. We report here that downregulation of p16INK4A gene expression in three different cervical carcinoma cell lines reduced expression of the E7 oncogene, suggesting a positive feedback loop involving E7 and p16INK4A. p16INK4A depletion induced cellular senescence in HeLa but not CaSki and MS-751 cervical carcinoma cells. IMPORTANCE This study demonstrates that the cdk inhibitor p16INK4A, frequently used as surrogate marker for transforming infections by human papillomaviruses of the high-risk group, is required for high-level expression of the E7 oncoproteins of HPV-16, HPV-18, and HPV-45 in cervical carcinoma cells. It is also demonstrated that depletion of p16INK4A induces senescence in HeLa but not CaSki or MS-751 cervical carcinoma cells. PMID:24599991

Pauck, Alexander; Lener, Barbara; Hoell, Monika; Kaiser, Andreas; Kaufmann, Andreas M.; Zwerschke, Werner

2014-01-01

292

Tumor suppressor p16INK4A is necessary for survival of cervical carcinoma cell lines.  

PubMed

The tumor suppressor p16(INK4A) inhibits formation of enzymatically active complexes of cyclin-dependent kinases 4 and 6 (CDK4/6) with D-type cyclins. Oncogenic stress induces p16(INK4A) expression, which in turn triggers cellular senescence through activation of the retinoblastoma tumor suppressor. Subversion of oncogene-induced senescence is a key step during cancer development, and many tumors have lost p16(INK4A) activity by mutation or epigenetic silencing. Human papillomavirus (HPV)-associated tumors express high levels of p16(INK4A) in response to E7 oncoprotein expression. Induction of p16(INK4A) expression is not a consequence of retinoblastoma tumor suppressor inactivation but is triggered by a cellular senescence response and is mediated by epigenetic derepression through the H3K27-specific demethylase (KDM)6B. HPV E7 expression causes an acute dependence on KDM6B expression for cell survival. The p16(INK4A) tumor suppressor is a critical KDM6B downstream transcriptional target and its expression is critical for cell survival. This oncogenic p16(INK4A) activity depends on inhibition of CDK4/CDK6, suggesting that in cervical cancer cells where retinoblastoma tumor suppressor is inactivated, CDK4/CDK6 activity needs to be inhibited in order for cells to survive. Finally, we note that HPV E7 expression creates a unique cellular vulnerability to small-molecule KDM6A/B inhibitors. PMID:24046371

McLaughlin-Drubin, Margaret E; Park, Donglim; Munger, Karl

2013-10-01

293

Chronic cadmium exposure in vitro induces cancer cell characteristics in human lung cells  

SciTech Connect

Cadmium is a known human lung carcinogen. Here, we attempt to develop an in vitro model of cadmium-induced human lung carcinogenesis by chronically exposing the peripheral lung epithelia cell line, HPL-1D, to a low level of cadmium. Cells were chronically exposed to 5 ?M cadmium, a noncytotoxic level, and monitored for acquired cancer characteristics. By 20 weeks of continuous cadmium exposure, these chronic cadmium treated lung (CCT-LC) cells showed marked increases in secreted MMP-2 activity (3.5-fold), invasion (3.4-fold), and colony formation in soft agar (2-fold). CCT-LC cells were hyperproliferative, grew well in serum-free media, and overexpressed cyclin D1. The CCT-LC cells also showed decreased expression of the tumor suppressor genes p16 and SLC38A3 at the protein levels. Also consistent with an acquired cancer cell phenotype, CCT-LC cells showed increased expression of the oncoproteins K-RAS and N-RAS as well as the epithelial-to-mesenchymal transition marker protein Vimentin. Metallothionein (MT) expression is increased by cadmium, and is typically overexpressed in human lung cancers. The major MT isoforms, MT-1A and MT-2A were elevated in CCT-LC cells. Oxidant adaptive response genes HO-1 and HIF-1A were also activated in CCT-LC cells. Expression of the metal transport genes ZNT-1, ZNT-5, and ZIP-8 increased in CCT-LC cells culminating in reduced cadmium accumulation, suggesting adaptation to the metal. Overall, these data suggest that exposure of human lung epithelial cells to cadmium causes acquisition of cancer cell characteristics. Furthermore, transformation occurs despite the cell's ability to adapt to chronic cadmium exposure. - Highlights: • Chronic cadmium exposure induces cancer cell characteristics in human lung cells. • This provides an in vitro model of cadmium-induced human lung cell transformation. • This occurred with general and lung specific changes typical for cancer cells. • These findings add insight to the relationship between cadmium and lung cancer.

Person, Rachel J.; Tokar, Erik J.; Xu, Yuanyuan; Orihuela, Ruben; Ngalame, Ntube N. Olive; Waalkes, Michael P., E-mail: waalkes@niehs.nih.gov

2013-12-01

294

Molecules in focus: The c-Cbl oncoprotein  

Microsoft Academic Search

Cbl has emerged as a novel signal transducing protein downstream of a number of cell surface receptors coupled to tyrosine kinases. Identified as the protein product of the c-cbl proto-oncogene, the cellular homolog to the transforming gene of a murine retrovirus, Cbl comprises an N-terminal transforming region (Cbl-N), which contains a phosphotyrosine binding (PTB) domain, and a C-terminal modular region

Mark L. Lupher Jr; Christopher E. Andoniou; David Bonita; Sachiko Miyake; Hamid Band

1998-01-01

295

Janus-faces of NME-oncoprotein interactions.  

PubMed

Since the identification of Nm23 (NME1, NME/NM23 nucleoside diphosphate kinase 1) as the first non-metastatic protein, a great deal of research on members of the NME family of proteins has focused on roles in processes implicated in carcinogenesis and particularly their regulation of cellular motility and the process of metastatic spread. To date, there are ten identified members of this family of genes, and these can be dichotomized into groups both taxonomically and by the presence or absence of their nucleoside diphosphate kinase activity with NMEs 1-4 encoding nucleoside diphosphate kinases (NDPKs) and NMEs 5-9 plus RP2 displaying little if any NDPK activity. NMEs are relatively small proteins that can form hetero-oligomers (typically hexamers), and given the apparent genetic redundancy of some NMEs and the number of different isoforms, it is perhaps not surprising that there remains a great deal of uncertainty regarding their function and even more regarding cellular mechanisms of action. Since residues that contribute to NDPK activity span much of the protein, it seems likely that the consequences of NME expression must be mediated through their NDPK activity, through interactions with other structures in cells including protein-protein interactions or through combinations of these. Our goal in this review is to focus on some of the protein-protein interactions that have been identified and to highlight some of the challenges that face this area of research. PMID:25366701

Vlatkovi?, Nikolina; Chang, Shie-Hong; Boyd, Mark T

2015-02-01

296

The Epstein-Barr virus bZIP transcription factor Zta causes G0/G1 cell cycle arrest through induction of cyclin-dependent kinase inhibitors.  

PubMed Central

While oncoproteins encoded by small DNA tumor viruses and Epstein-Barr virus (EBV) latent antigens facilitate G1/S progression, the EBV lytic switch transactivator Zta was found to inhibit growth by causing cell cycle arrest in G0/G1 in several epithelial tumor cell lines. Expression of Zta results in induction of the tumor suppressor protein, p53, and the cyclin-dependent kinase inhibitors, p21 and p27, as well as accumulation of hypophosphorylated pRb. Up-regulation of p53 and p27 occurs by post-transcriptional mechanisms while expression of p21 is induced at the RNA level in a p53-dependent manner. Inactivation of pRb by transient overexpression of the human papillomavirus E7 oncoprotein indicates that pRb or pRb-related proteins are key mediators of the growth-inhibitory function of Zta. These findings suggest that EBV plays an active role in redirecting epithelial cell physiology to facilitate the viral replicative program through a Zta-mediated growth arrest function. Images PMID:8654372

Cayrol, C; Flemington, E K

1996-01-01

297

Efficacy and safety of the fully human anti-tumour necrosis factor ? monoclonal antibody adalimumab (D2E7) in DMARD refractory patients with rheumatoid arthritis: a 12 week, phase II study  

PubMed Central

Objectives: To evaluate efficacy, dose response, safety, and tolerability of adalimumab (D2E7) in disease modifying antirheumatic drug (DMARD) refractory patients with longstanding, active rheumatoid arthritis (RA). Methods: During a 12 week, double blind, placebo controlled study, 284 patients were randomly allocated to receive weekly subcutaneous injections of adalimumab 20 mg (n = 72), 40 mg (n = 70), or 80 mg (n = 72) or placebo (n = 70) without concomitant DMARDs. Results: Adalimumab significantly improved the signs and symptoms of RA for all efficacy measures. ACR20 responses with adalimumab were significant at each assessment versus placebo (p?0.01). Additionally, ACR responses with adalimumab were achieved more rapidly than with placebo, with 82/115 (71%) of the ultimate ACR20 response rate to adalimumab treatment achieved at week 2. At week 12, for adalimumab 20, 40, and 80 mg, ACR20 response rates were 50.7%, 57.1%, and 54.2%, respectively, versus 10.0% for placebo (p?0.001 for all comparisons); ACR50 rates were 23.9%, 27.1%, and 19.4%, respectively, versus 1.4% for placebo (p?0.001 for all comparisons); and ACR70 rates were 11.3%, 10.0%, and 8.3%, respectively, versus 0.0% for placebo (p?0.05 for all comparisons). All adalimumab doses significantly improved all ACR core criteria at all assessments. The 40 mg and 80 mg doses provided similar benefit. Adalimumab at all doses was generally well tolerated, with only mild or moderate adverse events. Completion rates were 87% for adalimumab and 67% for placebo. Conclusions: Adalimumab given as monotreatment to patients with longstanding, severe RA refractory to traditional DMARDs produced a rapid, sustained response and was safe and well tolerated, with no dose limiting side effects. PMID:14644854

van de Putte, L B A; Rau, R; Breedveld, F; Kalden, J; Malaise, M; van Riel, P L C M; Schattenkirchner, M; Emery, P; Burmester, G; Zeidler, H; Moutsopoulos, H; Beck, K; Kupper, H

2003-01-01

298

Aurora-A down-regulates IkappaB? via Akt activation and interacts with insulin-like growth factor-1 induced phosphatidylinositol 3-kinase pathway for cancer cell survival  

PubMed Central

Background The mitotic Aurora-A kinase exerts crucial functions in maintaining mitotic fidelity. As a bona fide oncoprotein, Aurora-A aberrant overexpression leads to oncogenic transformation. Yet, the mechanisms by which Aurora-A enhances cancer cell survival remain to be elucidated. Results Here, we found that Aurora-A overexpression was closely correlated with clinic stage and lymph node metastasis in tongue carcinoma. Aurora-A inhibitory VX-680 suppressed proliferation, induced apoptosis and markedly reduced migration in cancer cells. We further showed that insulin-like growth factor-1, a PI3K physiological activator, reversed VX-680-decreased cell survival and motility. Conversely, wortmannin, a PI3K inhibitor, combined with VX-680 showed a synergistic effect on inducing apoptosis and suppressing migration. In addition, Aurora-A inhibition suppressed Akt activation, and VX-680-induced apoptosis was attenuated by Myr-Akt overexpression, revealing a cross-talk between Aurora-A and PI3K pathway interacting at Akt activation. Significantly, we showed that suppression of Aurora-A decreased phosphorylated Akt and was associated with increased IkappaB? expression. By contrast, Aurora-A overexpression upregulated Akt activity and downregulated IkappaB?, these changes were accompanied by nuclear translocation of nuclear factor-?B and increased expression of its target gene Bcl-xL. Lastly, Aurora-A overexpression induced IkappaB? reduction was abrogated by suppression of Akt either chemically or genetically. Conclusion Taken together, our data established that Aurora-A, via activating Akt, stimulated nuclear factor-?B signaling pathway to promote cancer cell survival, and promised a novel combined chemotherapy targeting both Aurora-A and PI3K in cancer treatment. PMID:19891769

2009-01-01

299

Polycyclic Aromatic Hydrocarbons—Induced ROS Accumulation Enhances Mutagenic Potential of T-Antigen From Human Polyomavirus JC  

PubMed Central

Polycyclic aromatic hydrocarbons (PAHs) are the products of incomplete combustion of organic materials, which are present in cigarette smoke, deep-fried food, and in natural crude oil. Since PAH-metabolites form DNA adducts and cause oxidative DNA damage, we asked if these environmental carcinogens could affect transforming potential of the human Polyomavirus JC oncoprotein, T-antigen (JCV T-antigen). We extracted DMSO soluble PAHs from Deepwater Horizon oil spill in the Gulf of Mexico (oil-PAHs), and detected several carcinogenic PAHs. The oil-PAHs were tested in exponentially growing cultures of normal mouse fibroblasts (R508), and in R508 stably expressing JCV T-antigen (R508/T). The oil-PAHs were cytotoxic only at relatively high doses (1:50–1:100 dilution), and at 1:500 dilution the growth and cell survival rates were practically unaffected. This non-toxic dose triggered however, a significant accumulation of reactive oxygen species (ROS), caused oxidative DNA damage and the formation of DNA double strand breaks (DSBs). Although oil-PAHs induced similar levels of DNA damage in R508 and R508/T cells, only T-antigen expressing cells demonstrated inhibition of high fidelity DNA repair by homologous recombination (HRR). In contrast, low-fidelity repair by non-homologous end joining (NHEJ) was unaffected. This potential mutagenic shift between DNA repair mechanisms was accompanied by a significant increase in clonal growth of R508/T cells chronically exposed to low doses of the oil-PAHs. Our results indicate for the first time carcinogenic synergy in which oil-PAHs trigger oxidative DNA damage and JCV T-antigen compromises DNA repair fidelity. PMID:23558788

WILK, ANNA; RSKI, PIOTR WALIGÓ; LASSAK, ADAM; VASHISTHA, HIMANSHU; LIRETTE, DAVID; TATE, DAVID; ZEA, ARNOLD H.; KOOCHEKPOUR, SHAHRIAR; RODRIGUEZ, PAULO; MEGGS, LEONARD G.; ESTRADA, JOHN J.; OCHOA, AUGUSTO; REISS, KRZYSZTOF

2014-01-01

300

The E2A and tal-1 helix-loop-helix proteins associate in vivo and are modulated by Id proteins during interleukin 6-induced myeloid differentiation.  

PubMed Central

The immunoglobulin enhancer-binding proteins, E12 and E47, encoded by the E2A gene belong to the basic helix-loop-helix (bHLH) family of regulatory proteins and act as transcriptional activators. In addition to their critical role in B-lymphocyte development, the E12 and E47 proteins have been implicated in the induction of myogenesis as heterodimeric partners of myogenic bHLH proteins, MyoD and myogenin. Here we demonstrate that the E2A proteins form heterodimers with the bHLH oncoprotein tal-1 in myeloid and erythroid cells and that these heterodimers specifically bind to the CANNTG DNA motif. Heterodimerization with tal-1 represses transactivation by E47 and could function to prevent the expression of immunoglobulin genes in cells other than B lymphocytes. DNA binding by E2A-tal-1 heterodimers in the M1 mouse myeloid cell line is abrogated upon terminal macrophage differentiation induced by the cytokine interleukin 6. The loss of E2A-tal-1 DNA binding is correlated with elevated expression of mRNA encoding the dominant negative HLH proteins, Id1 and particularly Id2. Moreover, recombinant Id proteins inhibit the E2A-tal-1-specific DNA binding activity from undifferentiated M1 cells. These results suggest that E2A-tal-1 heterodimers may play a role in preventing terminal differentiation in the myeloid lineage and provide a possible explanation for oncogenic transformation induced by ectopic tal-1 expression in acute T-cell lymphoblastic leukemias. Images PMID:8016095

Voronova, A F; Lee, F

1994-01-01

301

Flow-induced vibration  

Microsoft Academic Search

This book reports on dimensional analysis; ideal fluid models; vortex-induced vibration; galloping and flutter; instability of tube and cylinder arrays; vibrations induced by oscillating flow; vibration induced by turbulence and sound; damping of structures; sound induced by vortex shedding; vibrations of a pipe containing a fluid flow; indices. It covers the analysis of the vibrations of structures exposed to fluid

1990-01-01

302

Curcumin-induced Aurora-A suppression not only causes mitotic defect and cell cycle arrest but also alters chemosensitivity to anticancer drugs.  

PubMed

Overexpression of oncoprotein Aurora-A increases drug resistance and promotes lung metastasis of breast cancer cells. Curcumin is an active anticancer compound in turmeric and curry. Here we observed that Aurora-A protein and kinase activity were reduced in curcumin-treated human breast chemoresistant nonmetastatic MCF-7 and highly metastatic cancer MDA-MB-231 cells. Curcumin acts in a similar manner to Aurora-A small interfering RNA (siRNA), resulting in monopolar spindle formation, S and G2/M arrest, and cell division reduction. Ectopic Aurora-A extinguished the curcumin effects. The anticancer effects of curcumin were enhanced by Aurora-A siRNA and produced additivity and synergism effects in cell division and monopolar phenotype, respectively. Combination treatment with curcumin overrode the chemoresistance to four Food and Drug Administration (FDA)-approved anticancer drugs (ixabepilone, cisplatin, vinorelbine, or everolimus) in MDA-MB-231 cells, which was characterized by a decrease in cell viability and the occurrence of an additivity or synergy effect. Ectopic expression of Aurora-A attenuated curcumin-enhanced chemosensitivity to these four tested drugs. A similar benefit of curcumin was observed in MCF-7 cells treated with ixabepilone, the primary systemic therapy to patients with invasive breast cancer (stages IIA-IIIB) before surgery. Antagonism effect was observed when MCF-7 cells were treated with curcumin plus cisplatin, vinorelbine or everolimus. Curcumin-induced enhancement in chemosensitivity was paralleled by significant increases (additivity or synergy effect) in apoptosis and cell cycle arrest at S and G2/M phases, the consequences of Aurora-A inhibition. These results suggest that a combination of curcumin with FDA-approved anticancer drugs warrants further assessment with a view to developing a novel clinical treatment for breast cancer. PMID:24613085

Ke, Ching-Shiun; Liu, Hsiao-Sheng; Yen, Cheng-Hsin; Huang, Guan-Cheng; Cheng, Hung-Chi; Huang, Chi-Ying F; Su, Chun-Li

2014-05-01

303

FTY720 Induces Apoptosis of M2 Subtype Acute Myeloid Leukemia Cells by Targeting Sphingolipid Metabolism and Increasing Endogenous Ceramide Levels  

PubMed Central

The M2 subtype Acute Myeloid Leukemia (AML-M2) with t(8;21) represents an unmet challenge because of poor clinical outcomes in a sizable portion of patients. In this study,we report that FTY720 (Fingolimod), a sphingosine analogue and an FDA approved drug for treating of multiple sclerosis, shows antitumorigenic activity against the Kasumi-1 cell line, xenograft mouse models and leukemic blasts isolated from AML-M2 patients with t(8;21) translocation. Primary investigation indicated that FTY720 caused cell apoptosis through caspases and protein phosphatase 2A (PP2A) activation. Transcriptomic profiling further revealed that FTY720 treatment could upregulate AML1 target genes and interfere with genes involved in ceramide synthesis. Treatment with FTY720 led to the elimination of AML1-ETO oncoprotein and caused cell cycle arrest. More importantly, FTY720 treatment resulted in rapid and significant increase of pro-apoptotic ceramide levels, determined by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry based lipidomic approaches. Structural simulation model had also indicated that the direct binding of ceramide to inhibitor 2 of PP2A (I2PP2A) could reactivate PP2A and cause cell death. This study demonstrates, for the first time, that accumulation of ceramide plays a central role in FTY720 induced cell death of AML-M2 with t(8;21). Targeting sphingolipid metabolism by using FTY720 may provide novel insight for the drug development of treatment for AML-M2 leukemia. PMID:25050888

Li, Lianchun; Liu, Yuan-Fang; Wang, Jiang; Liu, Hong; Song, Heng; Jiang, Hualiang; Chen, Sai-Juan; Luo, Cheng; Li, Keqin Kathy

2014-01-01

304

DNA Damage-Induced Phosphorylation of p53 Alleviates Inhibition by MDM2  

Microsoft Academic Search

DNA-damaging agents signal to p53 through as yet unidentified posttranscriptional mechanisms. Here we show that phosphorylation of human p53 at serine 15 occurs after DNA damage and that this leads to reduced interaction of p53 with its negative regulator, the oncoprotein MDM2, in vivo and in vitro. Furthermore, using purified DNA-dependent protein kinase (DNA-PK), we demonstrate that phosphorylation of p53

Sheau-Yann Shieh; Masako Ikeda; Yoichi Taya; Carol Prives

1997-01-01

305

Hesperidin induces apoptosis and triggers autophagic markers through inhibition of Aurora-A mediated phosphoinositide-3-kinase/Akt/mammalian target of rapamycin and glycogen synthase kinase-3 beta signalling cascades in experimental colon carcinogenesis.  

PubMed

Abnormalities in the homeostasis mechanisms involved in cell survival and apoptosis are contributing factors for colon carcinogenesis. Interventions of these mechanisms by pharmacologically safer agents gain predominance in colon cancer prevention. We previously reported the chemopreventive efficacy of hesperidin against colon carcinogenesis. In the present study, we aimed at investigating the potential of hesperidin over the abrogated Aurora-A coupled pro-survival phosphoinositide-3-kinase (PI3K)/Akt signalling cascades. Further, the role of hesperidin over apoptosis and mammalian target of rapamycin (mTOR) mediated autophagic responses were studied. Azoxymethane (AOM) induced mouse model of colon carcinogenesis was involved in this study. Hesperidin treatment was provided either in initiation/post-initiation mode respectively. Hesperidin significantly altered AOM mediated anti-apoptotic scenario by modulating Bax/Bcl-2 ratio together with enhanced cytochrome-c release and caspase-3, 9 activations. In addition, hesperidin enhanced p53-p21 axis with concomitant decrease in cell cycle regulator. Hesperidin treatment caused significant up-regulation of tumour suppressor phosphatase and tensin homologue (PTEN) with a reduction in the expression of AOM mediated p-PI3K and p-Akt. Additionally, hesperidin administration exhibited inhibition against p-mTOR expression which in turn led to stimulation of autophagic markers Beclin-1 and LC3-II. Aurora-A an upstream regulator of PI3K/Akt pathway was significantly inhibited by hesperidin. Furthermore, hesperidin administration restored glycogen synthase kinase-3 beta (GSK-3?) activity which in turn prevented the accumulation of oncoproteins ?-catenin, c-jun and c-myc. Taken together, hesperidin supplementation initiated apoptosis via targeted inhibition of constitutively activated Aurora-A mediated PI3K/Akt/GSK-3? and mTOR pathways coupled with autophagic stimulation against AOM induced colon carcinogenesis. PMID:25047426

Saiprasad, Gowrikumar; Chitra, Palanivel; Manikandan, Ramar; Sudhandiran, Ganapasam

2014-09-01

306

Dynamics of ps-pulse induced gratings in LC panels  

NASA Astrophysics Data System (ADS)

In the present work we focused our attention on studies of PVK:TNF hybrid polymer liquid crystal panels under short pulse laser illumination conditions. The diffraction gratings in a LC panel were induced by crossed beams generated by doubled in frequency Nd:YAG laser ((lambda) equals 532 nm) delivering pulses of 20 ps duration. So induced gratings were read by a cw laser radiation coming from a weak power He-Ne laser working at (lambda) equals 632.8 nm. The temporal evolution of intensity of first order diffraction measured in PVK:TNF hybrid liquid crystal panels shows many interesting features and complexity dependent on various experimental conditions. The substantial diffraction is observed already in time less than 1 ms after the pulse and the grating decay is completed within hundreds of milliseconds. At least three different steps of grating build-up can be distinguished which depend in various ways on the experimental conditions. A tentative mechanism of the observed responses is discussed in connection with the photoconductive properties of polymeric layers and the optical and electrical properties of the used liquid crystal E-7 (Merck).

Bartkiewicz, Stanislaw; Miniewicz, Andrzej; Sahraoui, Bouchta; Kajzar, Francois

2002-06-01

307

Flow-induced vibration  

SciTech Connect

This book reports on dimensional analysis; ideal fluid models; vortex-induced vibration; galloping and flutter; instability of tube and cylinder arrays; vibrations induced by oscillating flow; vibration induced by turbulence and sound; damping of structures; sound induced by vortex shedding; vibrations of a pipe containing a fluid flow; indices. It covers the analysis of the vibrations of structures exposed to fluid flows; explores applications for offshore platforms and piping; wind-induced vibration of buildings, bridges, and towers; and acoustic and mechanical vibration of heat exchangers, power lines, and process ducting.

Blevins, R.D.

1990-01-01

308

Cavitation-resistant inducer  

DOEpatents

An improvement in an inducer for a pump wherein the inducer includes a hub, a plurality of radially extending substantially helical blades and a wall member extending about and encompassing an outer periphery of the blades. The improvement comprises forming adjacent pairs of blades and the hub to provide a substantially rectangular cross-sectional flow area which cross-sectional flow area decreases from the inlet end of the inducer to a discharge end of the inducer, resulting in increased inducer efficiency improved suction performance, reduced susceptibility to cavitation, reduced susceptibility to hub separation and reduced fabrication costs.

Dunn, Charlton (Calabasas, CA); Subbaraman, Maria R. (Canoga Park, CA)

1989-01-01

309

Induced gauge interactions revisited  

E-print Network

It has been shown that the old-fashioned idea of Sakharov's induced gravity and gauge interactions in the "one-loop dominance" version works astonishingly well yielding reasonable parameters. It appears that induced coupling constants of gauge interactions of the standard model assume qualitatively realistic values. Moreover, it is possible to induce the Barbero--Immirzi parameter of canonical gravity from the fields entering the standard model.

Bogus?aw Broda; Micha? Szanecki

2010-12-06

310

Movie induced tourism  

Microsoft Academic Search

Movies provide the objects and subjects for the gaze of many people, and for some people, movies induce them to travel to the locations where they were filmed. The data gathered at 12 US locations supports earlier anecdotal accounts of movie-induced tourism. This paper extends from earlier studies by suggesting a variety of reasons for this type of gaze and

Roger Riley; Dwayne Baker; Carlton S. Van Doren

1998-01-01

311

Flexoelectric polarization changes induced by light in a nematic liquid crystal  

NASA Astrophysics Data System (ADS)

In a nematic liquid crystal where the director field has a splay-bend deformation mediated by the boundary conditions there is a certain intrinsic polarization density distribution characteristic of the flexoelectric properties of the medium. By application of an electric field perpendicular to the director, a twist is induced which is a measure of the flexoelectric anisotropy [I. Dozov, Ph. Martinot-Lagarde, and G. Durand, J. Phys. (Paris) Lett. 43, L-365 (1982)]. We show that in molecules susceptible to a photoinduced configurational change we may change the volume polarization by UV illumination and relate the change in flexoelectric coefficients to the configurational change in the molecule. In the experiment we use the British Drug House (Merck) nematic mixture E7 doped with 5 wt % of the dye 4-hexyloxy-(4'-hexyl)azobenzene. The photoinduced trans-cis configurational change leads to an increase by 40% in the flexoelectric anisotropy (es-eb)/K.

Hermann, D. S.; Rudquist, P.; Ichimura, K.; Kudo, K.; Komitov, L.; Lagerwall, S. T.

1997-03-01

312

[Radiation induced carcinogenesis].  

PubMed

Intense research after Hiroshima and Nagasaki atomic bomb (A-bomb) tragedy and Chernobyl nuclear plant accident revealed that ionizing radiation (IR) more than 100 mSv induces cancers that are indistinguishable from sporadic tumors. It remains controversial whether low dose IR (less than 100 mSv) is oncogenic or not. Among IR-induced malignancies, leukemia (A-bomb) and thyroid cancers (Chernobyl), in which chimeric(fusion) oncogenes formed by chromosome translocations play a critical role, develop with relatively short latency. All other cancers develop after long latency. Age-related epigenetic changes, as well as additional genetic alterations, would contribute to IR-induced carcinogenesis. PMID:22514919

Inaba, Toshiya

2012-03-01

313

Glucocorticoid-induced osteonecrosis  

PubMed Central

Awareness of the need for prevention of glucocorticoid- induced fractures is growing, but glucocorticoid administration is often overlooked as the most common cause of nontraumatic osteonecrosis. Glucocorticoid- induced osteonecrosis develops in 9–40% of patients receiving long-term therapy although it may also occur with short-term exposure to high doses, after intra-articular injection, and without glucocorticoid-induced osteoporosis. The name, osteonecrosis, is misleading because the primary histopathological lesion is osteocyte apoptosis. Apoptotic osteocytes persist because they are anatomically unavailable for phagocytosis and, with glucocorticoid excess, decreased bone remodeling retards their replacement. Glucocorticoid-induced osteocyte apoptosis, a cumulative and unrepairable defect, uniquely disrupts the mechanosensory function of the osteocyte–lacunar–canalicular system and thus starts the inexorable sequence of events leading to collapse of the femoral head. Current evidence indicates that bisphosphonates may rapidly reduce pain, increase ambulation, and delay joint collapse in patients with osteonecrosis. PMID:22169965

Weinstein, Robert S.

2013-01-01

314

Vitiligo, drug induced (image)  

MedlinePLUS

... this person's face have resulted from drug-induced vitiligo. Loss of melanin, the primary skin pigment, occasionally ... is the case with this individual. The typical vitiligo lesion is flat (macular) and depigmented, but maintains ...

315

Statin induced myotoxicity.  

PubMed

Statins are an effective treatment for the prevention of cardiovascular diseases and used extensively worldwide. However, myotoxicity induced by statins is a common adverse event and a major barrier to maximising cardiovascular risk reduction. The clinical spectrum of statin induced myotoxicity includes asymptomatic rise in creatine kinase concentration, myalgia, myositis and rhabdomyolysis. In certain cases, the cessation of statin therapy does not result in the resolution of muscular symptoms or the normalization of creatine kinase, raising the possibility of necrotizing autoimmune myopathy. There is increasing understanding and recognition of the pathophysiology and risk factors of statin induced myotoxicity. Careful history and physical examination in conjunction with selected investigations such as creatine kinase measurement, electromyography and muscle biopsy in appropriate clinical scenario help diagnose the condition. The management of statin induced myotoxicity involves statin cessation, the use of alternative lipid lowering agents or treatment regimes, and in the case of necrotizing autoimmune myopathy, immunosuppression. PMID:22560377

Sathasivam, Sivakumar

2012-06-01

316

Thrombocytopenia - drug induced  

MedlinePLUS

... the condition is called drug-induced immune thrombocytopenia. Heparin, a blood thinner, is the most common cause ... include: Immunoglobulin therapy (IVIG) given through a vein Plasma exchange (plasmapheresis) Platelet transfusions Corticosteroids

317

Denture-Induced Stomatitis  

MedlinePLUS

... cleaning habits A build-up of the yeast Candida albicans , which can cause an infection Denture-induced ... They are more likely to be infected with Candida . People who smoke and those who do not ...

318

Drug-induced hepatitis  

MedlinePLUS

Toxic hepatitis ... to get liver damage. Some drugs can cause hepatitis with small doses, even if the liver breakdown ... liver. Many different drugs can cause drug-induced hepatitis. Painkillers and fever reducers that contain acetaminophen are ...

319

Drug-Induced Cholestasis  

Microsoft Academic Search

Medications and herbal supplements can induce a variety of hepatic, acute, and chronic cholestatic syndromes including bland\\u000a cholestasis, cholestasis with concurrent hepatitis, bile duct injury, and extrahepatic biliary strictures and stones. Most\\u000a cases of drug- and herbal-induced cholestasis are benign, but progression to chronic liver disease, cirrhosis, and death is\\u000a well described. We discuss the different types of cholestasis that

James P. Hamilton; Jacqueline M. Laurin

320

Chemotherapy-Induced Neurotoxicity  

Microsoft Academic Search

\\u000a Chemotherapy-induced neurotoxicity is a common and dose-limiting side effect of many cancer treatments. While other dose-limiting\\u000a toxicities such as myelosupression and hypersensitivity reactions are largely amenable to treatment, chemotherapy-induced\\u000a neurotoxicity remains a significant problem, with limited treatment options and no standardized diagnostic or management criteria.\\u000a Receiving a full course of chemotherapy on schedule is a critical factor that determines patient

Susanna B. Park; Matthew C. Kiernan

321

Isoniazid-induced alopecia  

PubMed Central

Isoniazid is a safe and very effective antituberculosis drug. Antimitotic agents routinely cause alopecia. Drug-induced alopecia is usually reversible upon withdrawal of the drug. Isoniazid, thiacetazone and ethionamide are the antituberculosis drugs which have been associated with alopecia. Isoniazid-induced alopecia was observed in one case and confirmed by the finding that hair growth resumed when drug removed from the regimen. PMID:21654989

Gupta, K. B.; Kumar, V.; Vishvkarma, S.; Shandily, R.

2011-01-01

322

Paroxetine-induced galactorrhea  

PubMed Central

Drug-induced galactorrhea has been reported with agents such as antidopaminergic antiemetics, antipsychotics, etc., with few case reports of galactorrhea with selective serotonin reuptake inhibitors, including paroxetine, being reported in last few decades. Prolactin levels have been found to be either raised or normal in these cases. We here report a case of paroxetine induced galactorrhea in a 48-year-old female patient of obsessive compulsive disorder, having hyperprolactinemic and euprolactinemic galactorrhea at different time with a pituitary incidentaloma.

Gulati, Prannay; Chavan, B. S.; Das, Subhash

2014-01-01

323

ECT-induced Mania  

PubMed Central

Electroconvulsive therapy can induce mania. A recent change in the Diagnostic and Statistical Manuel of Mental Disorders, Fifth Edition classifies electroconvulsive therapy-induced manic episodes as a bipolar type I diagnosis. There are no current established guidelines to treat such condition. The following clinical vignette describes a vignette in which a manic episode occurred following electroconvulsive therapy treatment. This case report examines the potential benefit of prescribing mood stabilizers during the acute episode and for maintenance care.

Lee, Jae; Arcand, Laura; Narang, Puneet

2014-01-01

324

Epidermal growth factor induces HCCR expression via PI3K/Akt/mTOR signaling in PANC-1 pancreatic cancer cells  

PubMed Central

Background Human cervical cancer oncoprotein 1 (HCCR-1), reported as a negative regulator of p53, is over-expressed in a variety of human cancers. However, it is yet unknown whether HCCR-1 plays any role in pancreatic cancer development. The aim of this study was to investigate the effect of epidermal growth factor on the expression of HCCR in pancreatic cancer cells, and to explore if PI3K/Akt/mTOR signaling pathway mediated this expression. Methods A polyclonal antibody against HCCR protein was raised by immunizing Balb/c mice with the purified recombinant protein pMBPc-HCCR. Tissue samples were constructed on a tissue chip, and the expression of HCCR was investigated by immunohistochemistry assay and Western blotting. Pancreatic cell line, PANC-1 cells were stably transfected with plasmids containing sense-HCCR-1 fragment and HCCR siRNA fragment. MTT and transwell assay were used to investigate the proliferation and invasion of stable tansfectants. The specific inhibitor of PI3K and mTOR was used to see if PI3K/mTOR signal transduction was involved in the induction of HCCR gene expression. A Luciferase assay was used to see if Akt can enhance the HCCR promoter activity. Results HCCR was up-regulated in pancreatic tumor tissues (mean Allred score 4.51 ± 1.549 vs. 2.87 ± 2.193, P < 0.01), especially with high expression in poorly differentiated pancreatic cancer. The growth of cells decreased in HCCR-1 siRNA transfected cells compared with vector transfectants. The number of invasion cells was significantly lower in HCCR-1 siRNA transfected cells (24.4 ± 9.9) than that in vector transfectants (49.1 ± 15.4). Treatment of PANC-1 cells with epidermal growth factor increased HCCR protein level in a dose- and time-dependent manner. However, application of LY294002 and rapamycin caused a dramatic reduction of epidermal growth factor-induced HCCR expression. Over-expression of exogenous constitutively active Akt increased the HCCR promoter activity; in contrast, dominant negative Akt decreased the promoter activity. Conclusions EGF-induced HCCR-1 over-expression is mediated by PI3K/AKT/mTOR signaling which plays a pivotal role in pancreatic tumor progression, suggesting that HCCR-1 could be a potential target for cancer therapeutics. PMID:20423485

2010-01-01

325

Induced polarization response of microbial induced sulfideprecipitation  

SciTech Connect

A laboratory scale experiment was conducted to examine the use of induced polarization and electrical conductivity to monitor microbial induced sulfide precipitation under anaerobic conditions in sand filled columns. Three columns were fabricated; one for electrical measurements, one for geochemical sampling and a third non-inoculated column was used as a control. A continual upward flow of nutrients and metals in solution was established in each column. Desulfovibrio vulgaris microbes were injected into the middle of the geochemical and electrical columns. Iron and zinc sulfides precipitated along a microbial action front as a result of sulfate reduction due by Desulfovibrio vulgaris. The precipitation front initially developed near the microbial injection location, and subsequently migrated towards the nutrient inlet, as a result of chemotaxis by Desulfovibrio vulgaris. Sampling during and subsequent to the experiment revealed spatiotemporal changes in the biogeochemical measurements associated with microbial sulfate reduction. Conductivity measurements were insensitive to all biogeochemical changes occurred within the column. Changes in the IP response (of up to 14 mrad)were observed to coincide in place and in time with the active microbe respiration/sulfide precipitation front as determined from geochemical sampling. The IP response is correlated with the lactate concentration gradient, an indirect measurement of microbial metabolism, suggesting the potential of IP as a method for monitoring microbial respiration/activity. Post experimental destructive sample analysis and SEM imaging verified the geochemical results and supported our hypothesis that microbe induced sulfide precipitation is directly detectable using electrical methods. Although the processes not fully understood, the IP response appears to be sensitive to this anaerobic microbial precipitation, suggesting a possible novel application for the IP method.

Ntarlagiannis, Dimitrios; Williams, Kenneth Hurst; Slater, Lee; Hubbard, Susan

2004-06-04

326

Drug-induced panniculitides.  

PubMed

A substantial number of all panniculitides fails to recognize a specific etiology, and that is true also for a relatively frequent type of panniculitis, such as erythema nodosum (EN). Between the recognized causative factors of panniculitides, infectious, physical agents, autoimmune mechanisms and neoplastic disorders are well known. On the contrary, the role of drugs as inducers of panniculitides is marginally considered, and their report limited to anecdotal observations, often without due histopathological support. Since the clinical and histopathological features of drug-induced panniculitides are indistinguishable from those caused by other agents, the causative relationship may be demonstrated by the history of previous drug intake and by clinical improvement after drug discontinuation. We reviewed the currently reported descriptions of drug-induced panniculitis, including a few exemplificative original observations. EN results as the most frequently reported drug-induced panniculitis. Among the causative drugs of EN a variety of medications, with disparate, or even opposite, mechanisms of action are reported, thus limiting the understanding of the pathogenesis. Common causative drugs include oral contraceptives, nonsteroidal anti-inflammatory drugs, antiobiotics and leukotriene-modifying agents. Unfortunately, in several cases, the diagnosis of drug-induced EN is done on clinical findings alone. In those cases, the lack of histopathological support does not allow to define a precise clinicopathological correlation on etiologic grounds. Drug-induced lobular and mixed panniculitides, including eosinophilic panniculitis, are even more rarely described. Reported causative agents are glatiramer acetate, interferon beta and heparin (at sites of injections), and systemic steroids, tyrosine kinase inhibitors and BRAF with subcutaneous fat involvement at distance. In view of the recent introduction of new classes of drugs, attention should be paid to disclose their possible etiologic role in inducing among other side effects, also panniculitides. PMID:24819647

Borroni, G; Torti, S; D'Ospina, R M; Pezzini, C

2014-04-01

327

Malathion-induced granulosa cell apoptosis in caprine antral follicles: an ultrastructural and flow cytometric analysis.  

PubMed

Organophosphate pesticides (OPs) like malathion interfere with normal ovarian function resulting in an increased incidence of atresia and granulosa cell apoptosis that plays a consequential role in the loss of ovarian follicles or follicular atresia. The aim of present study was to assess malathion-induced (100 nM) reproductive stress, ultrastructural damage and changes in apoptosis frequency in ovarian granulosa cells of antral follicles. Transmission electron microscopy (TEM) was employed for ultrastructural characterization, oxidative stress was evaluated using thiobarbituric acid reactive substances (TBARS) assay to measure lipid peroxidation, and apoptosis was quantified via flow cytometry. By TEM, apoptosis was identified by the presence of an indented nuclear membrane with blebbing, pyknotic crescent-shaped fragmented nuclei, increased vacuolization, degenerating mitochondria, and lipid droplets. The results indicate a significant increase in malondialdehyde (MDA) level (nmols/g wet tissue) at a 100 nM dose of malathion i.e. 7.57±0.033*, 8.53±0.12*, and 12.87±0.78** at 4, 6, or 8 h, respectively, as compared with controls (6.07±0.033, p<0.01*, p<0.05**) showing a positive correlation between malathion-induced lipid peroxidation and percentage of granulosa cell apoptosis (r=1; p<0.01). The parallel use of these three methods enabled us to determine the role of malathion in inducing apoptosis as a consequence of cytogenetic damage and oxidative stress generated in granulosa cells of antral follicles. PMID:25409908

Bhardwaj, Jitender K; Saraf, Priyanka

2014-12-01

328

Bicistronic DNA Vaccines Simultaneously Encoding HIV, HSV and HPV Antigens Promote CD8+ T Cell Responses and Protective Immunity  

PubMed Central

Millions of people worldwide are currently infected with human papillomavirus (HPV), herpes simplex virus (HSV) or human immunodeficiency virus (HIV). For this enormous contingent of people, the search for preventive and therapeutic immunological approaches represents a hope for the eradication of latent infection and/or virus-associated cancer. To date, attempts to develop vaccines against these viruses have been mainly based on a monovalent concept, in which one or more antigens of a virus are incorporated into a vaccine formulation. In the present report, we designed and tested an immunization strategy based on DNA vaccines that simultaneously encode antigens for HIV, HSV and HPV. With this purpose in mind, we tested two bicistronic DNA vaccines (pIRES I and pIRES II) that encode the HPV-16 oncoprotein E7 and the HIV protein p24 both genetically fused to the HSV-1 gD envelope protein. Mice i.m. immunized with the DNA vaccines mounted antigen-specific CD8+ T cell responses, including in vivo cytotoxic responses, against the three antigens. Under experimental conditions, the vaccines conferred protective immunity against challenges with a vaccinia virus expressing the HIV-derived protein Gag, an HSV-1 virus strain and implantation of tumor cells expressing the HPV-16 oncoproteins. Altogether, our results show that the concept of a trivalent HIV, HSV, and HPV vaccine capable to induce CD8+ T cell-dependent responses is feasible and may aid in the development of preventive and/or therapeutic approaches for the control of diseases associated with these viruses. PMID:23951135

Santana, Vinicius C.; Diniz, Mariana O.; Cariri, Francisco A. M. O.; Ventura, Armando M.; Cunha-Neto, Edécio; Almeida, Rafael R.; Campos, Marco A.; Lima, Graciela K.; Ferreira, Luís C. S.

2013-01-01

329

Bicistronic DNA vaccines simultaneously encoding HIV, HSV and HPV antigens promote CD8? T cell responses and protective immunity.  

PubMed

Millions of people worldwide are currently infected with human papillomavirus (HPV), herpes simplex virus (HSV) or human immunodeficiency virus (HIV). For this enormous contingent of people, the search for preventive and therapeutic immunological approaches represents a hope for the eradication of latent infection and/or virus-associated cancer. To date, attempts to develop vaccines against these viruses have been mainly based on a monovalent concept, in which one or more antigens of a virus are incorporated into a vaccine formulation. In the present report, we designed and tested an immunization strategy based on DNA vaccines that simultaneously encode antigens for HIV, HSV and HPV. With this purpose in mind, we tested two bicistronic DNA vaccines (pIRES I and pIRES II) that encode the HPV-16 oncoprotein E7 and the HIV protein p24 both genetically fused to the HSV-1 gD envelope protein. Mice i.m. immunized with the DNA vaccines mounted antigen-specific CD8? T cell responses, including in vivo cytotoxic responses, against the three antigens. Under experimental conditions, the vaccines conferred protective immunity against challenges with a vaccinia virus expressing the HIV-derived protein Gag, an HSV-1 virus strain and implantation of tumor cells expressing the HPV-16 oncoproteins. Altogether, our results show that the concept of a trivalent HIV, HSV, and HPV vaccine capable to induce CD8? T cell-dependent responses is feasible and may aid in the development of preventive and/or therapeutic approaches for the control of diseases associated with these viruses. PMID:23951135

Santana, Vinicius C; Diniz, Mariana O; Cariri, Francisco A M O; Ventura, Armando M; Cunha-Neto, Edécio; Almeida, Rafael R; Campos, Marco A; Lima, Graciela K; Ferreira, Luís C S

2013-01-01

330

Carmustine induces platelet apoptosis.  

PubMed

Abstract Carmustine is one of the alkylating chemotherapeutic agents, which are used to treat various types of cancers, such as brain tumors, Hodgkins and non-Hodgkins lymphoma and multiple myeloma. However, carmustine has the side effect of thrombocytopenia, and the mechanism is not completely understood. In this study, we show that carmustine dose-dependently induced depolarization of mitochondrial inner transmembrane potential (??m), up-regulation of Bax, down-regulation of Bcl-2 and caspase-3 activation. Carmustine did not induce surface expression of P-selectin or PAC-1 binding, whereas, obviously reduced collagen and thrombin-induced platelet aggregation. Dicumarol, c-Jun NH2-terminal kinase-specific inhibitor, reduced carmustine-induced ??m depolarization in platelets. The numbers of circulating platelets were reduced, and the tail bleeding time was significantly increased in mice that were injected with carmustine. Taken together, these data indicate that carmustine induced platelet apoptosis, suggesting the possible pathogenesis of thrombocytopenia in patients treated with carmustine. PMID:24955606

Zhang, Jie; Chen, Mengxing; Zhang, Yiwen; Zhao, Lili; Yan, Rong; Dai, Kesheng

2014-06-23

331

Werner syndrome protein limits MYC-induced cellular senescence  

PubMed Central

The MYC oncoprotein is a transcription factor that coordinates cell growth and division. MYC overexpression exacerbates genomic instability and sensitizes cells to apoptotic stimuli. Here we demonstrate that MYC directly stimulates transcription of the human Werner syndrome gene, WRN, which encodes a conserved RecQ helicase. Loss-of-function mutations in WRN lead to genomic instability, an elevated cancer risk, and premature cellular senescence. The overexpression of MYC in WRN syndrome fibroblasts or after WRN depletion from control fibroblasts led to rapid cellular senescence that could not be suppressed by hTERT expression. We propose that WRN up-regulation by MYC may promote MYC-driven tumorigenesis by preventing cellular senescence. PMID:12842909

Grandori, Carla; Wu, Kou-Juey; Fernandez, Paula; Ngouenet, Celine; Grim, Jonathan; Clurman, Bruce E.; Moser, Michael J.; Oshima, Junko; Russell, David W.; Swisshelm, Karen; Frank, Scott; Amati, Bruno; Dalla-Favera, Riccardo; Monnat, Raymond J.

2003-01-01

332

Radiation-induced gliomas  

PubMed Central

Radiation-induced gliomas represent a relatively rare but well-characterized entity in the neuro-oncologic literature. Extensive retrospective cohort data in pediatric populations after therapeutic intracranial radiation show a clearly increased risk in glioma incidence that is both patient age- and radiation dose/volume-dependent. Data in adults are more limited but show heightened risk in certain groups exposed to radiation. In both populations, there is no evidence linking increased risk associated with routine exposure to diagnostic radiation. At the molecular level, recent studies have found distinct genetic differences between radiation-induced gliomas and their spontaneously-occurring counterparts. Clinically, there is understandable reluctance on the part of clinicians to re-treat patients due to concern for cumulative neurotoxicity. However, available data suggest that aggressive intervention can lead to improved outcomes in patients with radiation-induced gliomas. PMID:19831840

Prasad, Gautam; Haas-Kogan, Daphne A.

2013-01-01

333

Radiation-induced meningiomas.  

PubMed

High dose radiation-induced meningiomas are a rare, severe and late complication of craniospinal radiotherapy for brain tumors. Radiation-induced meningiomas are, according to the literature, several times more frequent than radiogenic gliomas and sarcomas. It is suggested that every new case of radiogenic meningioma has to be reported to elucidate this particular pathologic entity with its many grey areas. In addition to high dose radiation-induced meningiomas, intracranial meningiomas were observed in patients who underwent low-dose radiation for tinea capitis in childhood, applied en mass to immigrants coming to Israel from the North Africa and the Middle East during the 1950. Authors summarize the data on radiogenic meningiomas from the literature and, as the previous radiotherapy may confer a low, but life-long risk for meningioma occurrence, they suggest that surveillance MRI after high dose cerebrospinal radiotherapy should be extended to several (3-5) decades after radiotherapy. PMID:11949834

Boljesíkova, E; Chorvath, M

2001-01-01

334

Neutron-induced nucleosynthesis  

E-print Network

Neutron--induced nucleosynthesis plays an important role in astrophysical scenarios like in primordial nucleosynthesis in the early universe, in the s--process occurring in Red Giants, and in the $\\alpha$--rich freeze--out and r--process taking place in supernovae of type II. A review of the three important aspects of neutron--induced nucleosynthesis is given: astrophysical background, experimental methods and theoretical models for determining reaction cross sections and reaction rates at thermonuclear energies. Three specific examples of neutron capture at thermal and thermonuclear energies are discussed in some detail.

H. Oberhummer; H. Herndl; T. Rauscher; H. Beer

1996-08-20

335

Bleomycin-induced pneumonitis  

Microsoft Academic Search

The cytotoxic agent bleomycin is feared for its induction of sometimes\\u000a fatal pulmonary toxicity, also known as bleomycin-induced pneumonitis\\u000a (BIP). The central event in the development of BIP is endothelial damage\\u000a of the lung vasculature due to bleomycin-induced cytokines and free\\u000a radicals. Ultimately, BIP can progress in lung fibrosis. The diagnosis is\\u000a established by a combination of clinical symptoms, radiographic

S. Sleijfer

2001-01-01

336

Warfarin-induced erythroderma.  

PubMed

Erythroderma is a potentially serious and life-threatening skin disease with a number of possible aetiologies. Drug reactions are well-documented causes, with carbamazepine, penicillin and allopurinol being the most commonly implicated. This case describes a unique presentation of warfarin-induced erythroderma in a 78-year-old female patient. PMID:24592901

Rowe, Casey J; Robertson, Ivan; James, Daniel; McMeniman, Erin

2015-02-01

337

Drug-induced uveitis.  

PubMed

A number of medications have been associated with uveitis. This review highlights both well-established and recently reported systemic, topical, intraocular, and vaccine-associated causes of drug-induced uveitis, and assigns a quantitative score to each medication based upon criteria originally described by Naranjo and associates. PMID:23522744

London, Nikolas Js; Garg, Sunir J; Moorthy, Ramana S; Cunningham, Emmett T

2013-01-01

338

Shrouded inducer pump  

DOEpatents

An improvement in a pump including a shrouded inducer, the improvement comprising first and second sealing means 32,36 which cooperate with a first vortex cell 38 and a series of secondary vortex cells 40 to remove any tangential velocity components from the recirculation flow.

Meng, Sen Y. (Reseda, CA)

1989-01-01

339

Laser-induced bioluminescence  

Microsoft Academic Search

A project has been initiated to determine the feasibility of developing a complete airborne remote sensing system for rapidly mapping high concentration patches of bioluminescent organisms in the world's oceans. Conceptually, this system would be composed of a laser illuminator to induce bioluminescence and a low light level image intensifier for detection of light. Initial laboratory measurements consisted of using

G. D. Hickman; R. V. Lynch III

1981-01-01

340

Shrouded inducer pump  

DOEpatents

An improvement in a pump is described including a shrouded inducer, the improvement comprising first and second sealing means which cooperate with a first vortex cell and a series of secondary vortex cells to remove any tangential velocity components from the recirculation flow. 3 figs.

Meng, S.Y.

1989-08-08

341

Drug-induced uveitis  

PubMed Central

A number of medications have been associated with uveitis. This review highlights both well-established and recently reported systemic, topical, intraocular, and vaccine-associated causes of drug-induced uveitis, and assigns a quantitative score to each medication based upon criteria originally described by Naranjo and associates. PMID:23522744

2013-01-01

342

Effects of Induced Astigmatism.  

ERIC Educational Resources Information Center

The relationship of astigmatism to reading and the possible detrimental effects it might have on reading were investigated. The greatest incidence of astigmatism was for the with-the-rule type ranging from .50 to 1.00 diopter. This type of astigmatism was induced in 35 seniors from the Los Angeles College of Optometry by placing cylindrical lenses…

Schubert, Delwyn G.; Walton, Howard N.

1968-01-01

343

Ethionamide-induced gynecomastia  

PubMed Central

Gynecomastia is very rare during antituberculosis chemotherapy. We describe a 38-year-old male patient who developed a painful gynecomastia following second-line drug therapy for multidrug-resistant pulmonary tuberculosis. Gynecomastia disappeared after stopping the ethionamide. A published literature on antituberculosis-induced gynecomastia is also briefly discussed. PMID:22629101

Dixit, Ramakant; George, Jacob; Sharma, Arun K.; chhabra, Naveen; Jangir, Suresh K.; Mishra, Vikas

2012-01-01

344

Geomagnetism and Induced Voltage  

ERIC Educational Resources Information Center

Introductory physics laboratories have seen an influx of "conceptual integrated science" over time in their classrooms with elements of other sciences such as chemistry, biology, Earth science, and astronomy. We describe a laboratory to introduce this development, as it attracts attention to the voltage induced in the human brain as it is…

Abdul-Razzaq, W.; Biller, R. D.

2010-01-01

345

Drug-induced hyperkalemia.  

PubMed

Hyperkalemia is a common clinical condition that can be defined as a serum potassium concentration exceeding 5.0 mmol/L. Drug-induced hyperkalemia is the most important cause of increased potassium levels in everyday clinical practice. Drug-induced hyperkalemia may be asymptomatic. However, it may be dramatic and life threatening, posing diagnostic and management problems. A wide range of drugs can cause hyperkalemia by a variety of mechanisms. Drugs can interfere with potassium homoeostasis either by promoting transcellular potassium shift or by impairing renal potassium excretion. Drugs may also increase potassium supply. The reduction in renal potassium excretion due to inhibition of the renin-angiotensin-aldosterone system represents the most important mechanism by which drugs are known to cause hyperkalemia. Medications that alter transmembrane potassium movement include amino acids, beta-blockers, calcium channel blockers, suxamethonium, and mannitol. Drugs that impair renal potassium excretion are mainly represented by angiotensin-converting enzyme inhibitors, angiotensin-II receptor blockers, direct renin inhibitors, nonsteroidal anti-inflammatory drugs, calcineurin inhibitors, heparin and derivatives, aldosterone antagonists, potassium-sparing diuretics, trimethoprim, and pentamidine. Potassium-containing agents represent another group of medications causing hyperkalemia. Increased awareness of drugs that can induce hyperkalemia, and monitoring and prevention are key elements for reducing the number of hospital admissions, morbidity, and mortality related to drug-induced hyperkalemia. PMID:25047526

Ben Salem, Chaker; Badreddine, Atef; Fathallah, Neila; Slim, Raoudha; Hmouda, Houssem

2014-09-01

346

Injection-induced earthquakes.  

PubMed

Earthquakes in unusual locations have become an important topic of discussion in both North America and Europe, owing to the concern that industrial activity could cause damaging earthquakes. It has long been understood that earthquakes can be induced by impoundment of reservoirs, surface and underground mining, withdrawal of fluids and gas from the subsurface, and injection of fluids into underground formations. Injection-induced earthquakes have, in particular, become a focus of discussion as the application of hydraulic fracturing to tight shale formations is enabling the production of oil and gas from previously unproductive formations. Earthquakes can be induced as part of the process to stimulate the production from tight shale formations, or by disposal of wastewater associated with stimulation and production. Here, I review recent seismic activity that may be associated with industrial activity, with a focus on the disposal of wastewater by injection in deep wells; assess the scientific understanding of induced earthquakes; and discuss the key scientific challenges to be met for assessing this hazard. PMID:23846903

Ellsworth, William L

2013-07-12

347

Ethionamide-induced gynecomastia.  

PubMed

Gynecomastia is very rare during antituberculosis chemotherapy. We describe a 38-year-old male patient who developed a painful gynecomastia following second-line drug therapy for multidrug-resistant pulmonary tuberculosis. Gynecomastia disappeared after stopping the ethionamide. A published literature on antituberculosis-induced gynecomastia is also briefly discussed. PMID:22629101

Dixit, Ramakant; George, Jacob; Sharma, Arun K; Chhabra, Naveen; Jangir, Suresh K; Mishra, Vikas

2012-04-01

348

Pneumonitis induced by rifampicin  

Microsoft Academic Search

An 81 year old man was admitted to hospital with pulmonary Mycobacterium tuberculosis infection and was treated with rifampicin (RFP), isoniazid (INH), and ethambutol (EB). On day 9 he developed fever and dyspnoea. Chest radiographs showed new infiltration shadows in the right lung. Bronchoalveolar lavage (BAL) was performed and increased numbers of lymphocytes were recovered. Drug induced pneumonitis was suspected

N Kunichika; N Miyahara; K Kotani; H Takeyama; M Harada; M Tanimoto

2002-01-01

349

Radioactivity Induced by Neutrons  

Microsoft Academic Search

AMALDI, d'Agostino and Segrè1 report that, using neutrons from a radon - alpha particle - beryllium source, they have induced an activity in indium of a very short half-life period (13 see.) and also one of half-life period of about one hour (54 min.).

Leo Szilard; T. A. Chalmers

1935-01-01

350

Rifampicin-induced thrombocytopenia  

PubMed Central

In the treatment of tuberculosis there are special therapeutic problems related to adverse effects of drugs, compliance to treatment, and microbial resistance. Thrombocytopenia is an uncommon but potentially fatal adverse effect of certain anti-tubercular drugs when the incriminating drug is taken by a susceptible individual. We report a case of rifampicin-induced thrombocytopenia, which although rare, needs attention. PMID:20927251

Verma, Ajay Kumar; Singh, Arpita; Chandra, Amol; Kumar, Santosh; Gupta, Rajesh Kumar

2010-01-01

351

Drug-induced pulmonary disease  

MedlinePLUS

Drug-induced pulmonary disease is lung disease brought on by a bad reaction to a medicine. ... Maldonado F, Limper AH. Drug-induced pulmonary disease. In: Mason RJ, ... of Respiratory Medicine . 5th ed. Philadelphia, PA: Elsevier ...

352

Noise-Induced Hearing Loss  

MedlinePLUS

Home Health Info Hearing, Ear Infections, and Deafness Noise-Induced Hearing Loss Noise-Induced Hearing Loss On this page: What is noise-induced hearing ... continue constantly or occasionally throughout a person’s life. Hearing loss ... or both ears. Sometimes exposure to impulse or continuous loud noise ...

353

Bulgy tadpoles: inducible defense morph  

Microsoft Academic Search

Predator induced morphological defenses are marked morphological shifts induced directly by cues associated with a predator. Generally, remote cues, i.e., chemical substances emitted from predators or injured conspecifics, are considered to be ideal signals to induce morphological change in aquatic environments rather than close cues, i.e., close chemical or tactile cues, since chemical substances that can propagate over relatively long

Osamu Kishida; Kinya Nishimura

2004-01-01

354

Tulipalin A induced phytotoxicity  

PubMed Central

Tulipalin A induced phytotoxicity is a persistent allergic contact dermatitides documented in floral workers exposed to Alstroemeria and its cultivars.[1] The causative allergen is tulipalin A, a toxic glycoside named for the tulip bulbs from which it was first isolated.[2] The condition is characterized by fissured acropulpitis, often accompanied by hyperpigmentation, onychorrhexis, and paronychia. More of the volar surface may be affected in sensitized florists. Dermatitis and paronychia are extremely common conditions and diagnostic errors may occur. A thorough patient history, in conjunction with confirmatory patch testing with a bulb sliver and tuliposide A exposure, can prevent misdiagnosis. We report a case of Tulipalin A induced phytotoxicity misdiagnosed as an unresolved tinea manuum infection in a patient evaluated for occupational exposure. PMID:25024947

McCluskey, James; Bourgeois, Marie; Harbison, Raymond

2014-01-01

355

Tulipalin A induced phytotoxicity.  

PubMed

Tulipalin A induced phytotoxicity is a persistent allergic contact dermatitides documented in floral workers exposed to Alstroemeria and its cultivars.[1] The causative allergen is tulipalin A, a toxic glycoside named for the tulip bulbs from which it was first isolated.[2] The condition is characterized by fissured acropulpitis, often accompanied by hyperpigmentation, onychorrhexis, and paronychia. More of the volar surface may be affected in sensitized florists. Dermatitis and paronychia are extremely common conditions and diagnostic errors may occur. A thorough patient history, in conjunction with confirmatory patch testing with a bulb sliver and tuliposide A exposure, can prevent misdiagnosis. We report a case of Tulipalin A induced phytotoxicity misdiagnosed as an unresolved tinea manuum infection in a patient evaluated for occupational exposure. PMID:25024947

McCluskey, James; Bourgeois, Marie; Harbison, Raymond

2014-04-01

356

Pseudoelephantiasis induced by donovanosis.  

PubMed Central

In a recent survey the incidence of pseudoelephantiasis induced by donovanosis was found to be 5%. The ratio of women to men was 3:1. The incubation period was two to 20 days, and the duration was two to 24 months. The disease was contracted through premarital or extramarital sexual intercourse. The morphological features were characterised in women by globular pedunculated verrucous surfaced swellings affecting the labia majora and the clitoris and accompanying ulceration or its aftermath (depigmentation), or both. Constitutional symptoms were absent. Intracytoplasmic Donovan bodies in the tissue or a smear from the ulcers were diagnostic. Immune markers, such as total T lymphocytes and their subsets (T4 (helper/inducer) and T8 (suppressor/cytotoxic), B lymphocytes, immunoglobulins G, A, and M, and the pivotal complement component C3 were largely inconsequential. Images PMID:3817826

Sehgal, V N; Jain, M K; Sharma, V K

1987-01-01

357

Remotely induced atmospheric lasing  

SciTech Connect

We propose and analyze a remote atmospheric lasing configuration which utilizes a combination of an ultrashort pulse laser to form a plasma filament (seed electrons) by tunneling ionization and a heater pulse which thermalizes the seed electrons. Electrons collisionally excite nitrogen molecules and induce lasing in the ultraviolet. The lasing gain is sufficiently high to reach saturation within the length of the plasma filament. A remotely generated ultraviolet source may have applications for standoff detection of biological and chemical agents.

Sprangle, Phillip; Penano, Joseph; Gordon, Daniel [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States); Hafizi, Bahman [Icarus Research, Inc., PO Box 30780, Bethesda, Maryland 20824-0780 (United States); Scully, Marlan [Departments of Physics and Electrical Engineering, Texas A and M University, College Station, Texas 77843 (United States); Departments of Chemistry and Aerospace and Mechanical Engineering, Princeton University, Princeton, New Jersey 08544 (United States)

2011-05-23

358

Lime-induced phytophotodermatitis  

PubMed Central

This case describes a scenario of lime-induced phytophotodermatitis. Phytophotodermatitis is a dermatitis caused after the skin is exposed to photosensitizing compounds in plants and then exposed to sunlight. Many common plants including citrus fruits, celery, and wild parsnip contain these photosensitizing compounds which cause phytophotodermatitis. It is important for a physician to be aware of phytophotodermatitis because it may often be misdiagnosed as other skin conditions including fungal infection, cellulitis, allergic contact dermatitis, and even child abuse. PMID:25317269

Hankinson, Andrew; Lloyd, Benjamin; Alweis, Richard

2014-01-01

359

Lime-induced phytophotodermatitis.  

PubMed

This case describes a scenario of lime-induced phytophotodermatitis. Phytophotodermatitis is a dermatitis caused after the skin is exposed to photosensitizing compounds in plants and then exposed to sunlight. Many common plants including citrus fruits, celery, and wild parsnip contain these photosensitizing compounds which cause phytophotodermatitis. It is important for a physician to be aware of phytophotodermatitis because it may often be misdiagnosed as other skin conditions including fungal infection, cellulitis, allergic contact dermatitis, and even child abuse. PMID:25317269

Hankinson, Andrew; Lloyd, Benjamin; Alweis, Richard

2014-01-01

360

Methods for Inducing Pluripotency  

Microsoft Academic Search

\\u000a Induced pluripotent stem (iPS) cells are embryonic stem-like cells produced by forcing expression of a minimal number of key\\u000a factors in differentiated somatic cells. In many ways, they are indistinguishable from embryonic stem cells in that they can\\u000a differentiate into any cell type in the body. This development has led to worldwide excitement over the possibility to develop\\u000a cell-based therapies

Raymond L. Page; Christopher Malcuit; Tanja Dominko

361

The Adenovirus E1A Proteins Induce Apoptosis, which is Inhibited by the E1B 19-kDa and Bcl2 Proteins  

Microsoft Academic Search

Cooperation between the adenovirus E1A and E1B oncogenes is required for transformation of primary quiescent rodent cells. Although expression of E1A alone will stimulate cell proliferation sufficient to initiate transformed focus formation, proliferation fails to be sustained and foci degenerate. Coexpression of either the 19-kDa or 55-kDa E1B oncoproteins with E1A permits high-frequency transformation by overcoming this cytotoxic response. Without

Lakshmi Rao; Michael Debbas; Peter Sabbatini; David Hockenbery; Stanley Korsmeyer; Eileen White

1992-01-01

362

Glycerol-induced hyperhydration  

NASA Technical Reports Server (NTRS)

Maintenance of euhydration is essential for maximum work performance. Environments which induce hypohydration reduce plasma volume and cardiovascular performance progressively declines as does work capacity. Hyperhydration prior to exposure to dehydrating environments appears to be a potential countermeasure to the debilitating effects of hypohydration. The extravascular fluid space, being the largest fluid compartment in the body, is the most logical space by which significant hyperhydration can be accomplished. Volume and osmotic receptors in the vascular space result in physiological responses which counteract hyperhydration. Our hypothesis is that glycerol-induced hyperhydration (GIH) can accomplish extravascular fluid expansion because of the high solubility of glycerol in lipid and aqueous media. A hypertonic solution of glycerol is rapidly absorbed from the gastrointestinal tract, results in mild increases in plasma osmolality and is distributed to 65 percent of the body mass. A large volume of water ingested within minutes after glycerol intake results in increased total body water because of the osmotic action and distribution of glycerol. The resulting expanded extravascular fluid space can act as a reservoir to maintain plasma volume during exposure to dehydrating environments. The fluid shifts associated with exposure to microgravity result in increased urine production and is another example of an environment which induces hypohydration. Our goal is to demonstrate that GIH will facilitate maintenance of euhydration and cardiovascular performance during space flight and upon return to a 1 g environment.

Riedesel, Marvin L.; Lyons, Timothy P.; Mcnamara, M. Colleen

1991-01-01

363

Sepsis-induced myopathy  

PubMed Central

Sepsis is a major cause of morbidity and mortality in critically ill patients, and despite advances in management, mortality remains high. In survivors, sepsis increases the risk for the development of persistent acquired weakness syndromes affecting both the respiratory muscles and the limb muscles. This acquired weakness results in prolonged duration of mechanical ventilation, difficulty weaning, functional impairment, exercise limitation, and poor health-related quality of life. Abundant evidence indicates that sepsis induces a myopathy characterized by reductions in muscle force-generating capacity, atrophy (loss of muscle mass), and altered bioenergetics. Sepsis elicits derangements at multiple subcellular sites involved in excitation contraction coupling, such as decreasing membrane excitability, injuring sarcolemmal membranes, altering calcium homeostasis due to effects on the sarcoplasmic reticulum, and disrupting contractile protein interactions. Muscle wasting occurs later and results from increased proteolytic degradation as well as decreased protein synthesis. In addition, sepsis produces marked abnormalities in muscle mitochondrial functional capacity and when severe, these alterations correlate with increased death. The mechanisms leading to sepsis-induced changes in skeletal muscle are linked to excessive localized elaboration of proinflammatory cytokines, marked increases in free-radical generation, and activation of proteolytic pathways that are upstream of the proteasome including caspase and calpain. Emerging data suggest that targeted inhibition of these pathways may alter the evolution and progression of sepsis-induced myopathy and potentially reduce the occurrence of sepsis-mediated acquired weakness syndromes. PMID:20046121

Callahan, Leigh Ann; Supinski, Gerald S.

2014-01-01

364

Radiation Induced Genomic Instability  

SciTech Connect

Radiation induced genomic instability can be observed in the progeny of irradiated cells multiple generations after irradiation of parental cells. The phenotype is well established both in vivo (Morgan 2003) and in vitro (Morgan 2003), and may be critical in radiation carcinogenesis (Little 2000, Huang et al. 2003). Instability can be induced by both the deposition of energy in irradiated cells as well as by signals transmitted by irradiated (targeted) cells to non-irradiated (non-targeted) cells (Kadhim et al. 1992, Lorimore et al. 1998). Thus both targeted and non-targeted cells can pass on the legacy of radiation to their progeny. However the radiation induced events and cellular processes that respond to both targeted and non-targeted radiation effects that lead to the unstable phenotype remain elusive. The cell system we have used to study radiation induced genomic instability utilizes human hamster GM10115 cells. These cells have a single copy of human chromosome 4 in a background of hamster chromosomes. Instability is evaluated in the clonal progeny of irradiated cells and a clone is considered unstable if it contains three or more metaphase sub-populations involving unique rearrangements of the human chromosome (Marder and Morgan 1993). Many of these unstable clones have been maintained in culture for many years and have been extensively characterized. As initially described by Clutton et al., (Clutton et al. 1996) many of our unstable clones exhibit persistently elevated levels of reactive oxygen species (Limoli et al. 2003), which appear to be due dysfunctional mitochondria (Kim et al. 2006, Kim et al. 2006). Interestingly, but perhaps not surprisingly, our unstable clones do not demonstrate a “mutator phenotype” (Limoli et al. 1997), but they do continue to rearrange their genomes for many years. The limiting factor with this system is the target – the human chromosome. While some clones demonstrate amplification of this chromosome and thus lend themselves to prolonged study, many tend to eliminate or rearrange the target chromosome until it is too small for further rearrangement. The observed frequency of induced instability by low and high linear-energy-transfer radiations greatly exceeds that observed for nuclear gene mutations at similar doses; hence, mutation of a gene or gene family is unlikely to be the initiating mechanism. Once initiated however, there is evidence in the GM10115 model system that it can be perpetuated over time by dicentric chromosome formation followed by bridge breakage fusion cycles (Marder and Morgan 1993), as well as recombinational events involving interstitial telomere like repeat sequences (Day et al. 1998). There is also increasing evidence that inflammatory type reactions (Lorimore et al. 2001, Lorimore and Wright 2003), presumably involving reactive oxygen and nitrogen species as well as cytokines and chemokines might be involved in driving the ustable phenotype (Liaikis et al. 2007, Hei et al. 2008). To this end there is very convincing evidence for such reactions being involved in another non-targeted effect associated with ionizing radiation, the bystander effect (Hei et al. 2008). Clearly the link between induced instability and bystander effects suggests common processes and inflammatory type reactions will likely be the subject of future investigation.

Morgan, William F.

2011-03-01

365

Nonlinearity induced critical coupling.  

PubMed

We study a critically coupled system [Opt. Lett. 32, 1483 (2007)] with a Kerr nonlinear spacer layer. Nonlinearity is shown to inhibit null scattering in a critically coupled system at low powers. However, a system detuned from critical coupling can exhibit near-complete suppression of scattering by means of nonlinearity-induced changes in refractive index. Our studies reveal clearly an important aspect of critical coupling as a delicate balance in both the amplitude and the phase relations, while a nonlinear resonance in dispersive bistability concerns only the phase. PMID:23939099

Nireekshan Reddy, K; Gopal, Achanta Venu; Dutta Gupta, S

2013-07-15

366

Nonlinearity Induced Critical Coupling  

E-print Network

We study a critically coupled system (Opt. Lett., \\textbf{32}, 1483 (2007)) with a Kerr-nonlinear spacer layer. Nonlinearity is shown to inhibit null-scattering in a critically coupled system at low powers. However, a system detuned from critical coupling can exhibit near-complete suppression of scattering by means of nonlinearity-induced changes in refractive index. Our studies reveal clearly an important aspect of critical coupling as a delicate balance in both the amplitude and the phase relations, while a nonlinear resonance in dispersive bistability concerns only the phase.

Reddy, K Nireekshan; Gupta, S Dutta

2013-01-01

367

Coherence-induced entanglement  

E-print Network

Coherence-induced entanglement Fu-li Li, Han Xiong, and M. Suhail Zubairy Institute for Quantum Studies and Department of Physics, Texas A&M University, College Station, Texas 77843-4242, USA #1;Received 7 March 2005; published 19 July 2005#2... of atomic coherence. DOI: 10.1103/PhysRevA.72.010303 PACS number#1;s#2;: 03.67.Mn, 03.65.Ud Atomic coherence #3;1#4;, which results from a coherent su- perposition of different states of a single atom, can lead to many different quantum optical phenomena...

Li, F. L.; Xiong, H.; Zubairy, M. Suhail

2005-01-01

368

Neutron Induced Beta Radiography  

SciTech Connect

In the present paper we give a new methodology named, 'neutron induced beta radiography-NIBR' which makes use of neutron activated Dy or In foils as source of (3-radiation. Radiographs are obtained with an aluminium cassette containing image plate, a sample under inspection and the activated Dy or In foil kept in tight contact. The sensitivity of the technique to thickness was evaluated for different materials in the form of step wedges. Some radiographs are presented to demonstrate potential of method to inspect thin samples.

Shaikh, A. M.; Shylaja, D. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

2011-07-15

369

Method for inducing hypothermia  

DOEpatents

Systems for phase-change particulate slurry cooling equipment and methods to induce hypothermia in a patient through internal and external cooling are provided. Subcutaneous, intravascular, intraperitoneal, gastrointestinal, and lung methods of cooling are carried out using saline ice slurries or other phase-change slurries compatible with human tissue. Perfluorocarbon slurries or other slurry types compatible with human tissue are used for pulmonary cooling. And traditional external cooling methods are improved by utilizing phase-change slurry materials in cooling caps and torso blankets.

Becker, Lance B. (Chicago, IL); Hoek, Terry Vanden (Chicago, IL); Kasza, Kenneth E. (Palos Park, IL)

2008-09-09

370

Method for inducing hypothermia  

DOEpatents

Systems for phase-change particulate slurry cooling equipment and methods to induce hypothermia in a patient through internal and external cooling are provided. Subcutaneous, intravascular, intraperitoneal, gastrointestinal, and lung methods of cooling are carried out using saline ice slurries or other phase-change slurries compatible with human tissue. Perfluorocarbon slurries or other slurry types compatible with human tissue are used for pulmonary cooling. And traditional external cooling methods are improved by utilizing phase-change slurry materials in cooling caps and torso blankets.

Becker, Lance B. (Chicago, IL); Hoek, Terry Vanden (Chicago, IL); Kasza, Kenneth E. (Palos Park, IL)

2003-04-15

371

Cephalexin Induced Cholestatic Jaundice  

PubMed Central

Cephalexin is a very commonly prescribed orally administered antibiotic which has many potential side effects. Amongst these cholestatic jaundice has been infrequently reported as an adverse reaction. We present a case of a 57-year-old male who exhibited features of cholestatic jaundice including elevated liver function tests (LFTs) after taking cephalexin and showed improvement on removal of the offending agent. During this time he was symptomatically treated with cholestyramine. Complete resolution of LFTs was seen in four weeks. Cephalexin induced cholestasis is rare and hence requires a high degree of clinical suspicion for prompt diagnosis and treatment. PMID:25180107

Jasdanwala, Sarfaraz; Mathur, Ajay; Eng, Margaret

2014-01-01

372

Dapsone induced eosinophilic pneumonia.  

PubMed

Eosinophilic lung diseases (ELD) are a variety of several clinical entities, which may result from different etiologies, including drug treatment. Dapsone, a sulfone antibiotic widely used in leprosy (among other indications), has been described as a possible cause of ELD. We report a patient with leprosy who presented with respiratory symptoms and pulmonary infiltrates and was diagnosed as suffering from eosinophilic pneumonia. To the best of our knowledge, this is the first report in which the diagnosis of dapsone-induced eosinophilic pneumonia was supported by bronchoalveolar lavage, lung biopsy and typical response to therapy. PMID:22905598

Adar, T; Tayer-Shifman, O; Mizrahi, M; Tavdi, S; Barak, O; Shalit, M

2012-06-01

373

Diversity-induced resonance.  

PubMed

We present conclusive evidence showing that different sources of diversity, such as those represented by quenched disorder or noise, can induce a resonant collective behavior in an ensemble of coupled bistable or excitable systems. Our analytical and numerical results show that when such systems are subjected to an external subthreshold signal, their response is optimized for an intermediate value of the diversity. These findings show that intrinsic diversity might have a constructive role and suggest that natural systems might profit from their diversity in order to optimize the response to an external stimulus. PMID:17155633

Tessone, Claudio J; Mirasso, Claudio R; Toral, Raúl; Gunton, James D

2006-11-10

374

[Exercise-induced asthma].  

PubMed

Exercise-induced asthma is characterized by a transient rise of the airways resistances, associated with asthmatic symptoms, 5 to 10 minutes after the end of a submaximal effort. The treatment is based on a pre-effort warming, cover the mouth with a mask (when the weather is cold), the use of beta-mimetic bronchodilators before exercise and, chronic treatment with antiinflammatory drugs. When the patient is not controlled, an evaluation of the lung function is required with a postbronchodilator control or an exercise challenge test. If the patient remains uncontrolled despite the treatment, others diagnostics should be excluded, such as vocal cords dysfunction or left heart failure. PMID:21089401

Michel, O

2010-09-01

375

Drug-Induced Parkinsonism  

PubMed Central

Drug-induced parkinsonism (DIP) is the second-most-common etiology of parkinsonism in the elderly after Parkinson's disease (PD). Many patients with DIP may be misdiagnosed with PD because the clinical features of these two conditions are indistinguishable. Moreover, neurological deficits in patients with DIP may be severe enough to affect daily activities and may persist for long periods of time after the cessation of drug taking. In addition to typical antipsychotics, DIP may be caused by gastrointestinal prokinetics, calcium channel blockers, atypical antipsychotics, and antiepileptic drugs. The clinical manifestations of DIP are classically described as bilateral and symmetric parkinsonism without tremor at rest. However, about half of DIP patients show asymmetrical parkinsonism and tremor at rest, making it difficult to differentiate DIP from PD. The pathophysiology of DIP is related to drug-induced changes in the basal ganglia motor circuit secondary to dopaminergic receptor blockade. Since these effects are limited to postsynaptic dopaminergic receptors, it is expected that presynaptic dopaminergic neurons in the striatum will be intact. Dopamine transporter (DAT) imaging is useful for diagnosing presynaptic parkinsonism. DAT uptake in the striatum is significantly decreased even in the early stage of PD, and this characteristic may help in differentiating PD from DIP. DIP may have a significant and longstanding effect on patients' daily lives, and so physicians should be cautious when prescribing dopaminergic receptor blockers and should monitor patients' neurological signs, especially for parkinsonism and other movement disorders. PMID:22523509

Shin, Hae-Won

2012-01-01

376

Cholesterol depletion induces autophagy  

SciTech Connect

Autophagy is a mechanism to digest cells' own components, and its importance in many physiological and pathological processes is being recognized. But the molecular mechanism that regulates autophagy is not understood in detail. In the present study, we found that cholesterol depletion induces macroautophagy. The cellular cholesterol in human fibroblasts was depleted either acutely using 5 mM methyl-{beta}-cyclodextrin or 10-20 {mu}g/ml nystatin for 1 h, or metabolically by 20 {mu}M mevastatin and 200 {mu}M mevalonolactone along with 10% lipoprotein-deficient serum for 2-3 days. By any of these protocols, marked increase of LC3-II was detected by immunoblotting and by immunofluorescence microscopy, and the increase was more extensive than that caused by amino acid starvation, i.e., incubation in Hanks' solution for several hours. The induction of autophagic vacuoles by cholesterol depletion was also observed in other cell types, and the LC3-positive membranes were often seen as long tubules, >50 {mu}m in length. The increase of LC3-II by methyl-{beta}-cyclodextrin was suppressed by phosphatidylinositol 3-kinase inhibitors and was accompanied by dephosphorylation of mammalian target of rapamycin. By electron microscopy, autophagic vacuoles induced by cholesterol depletion were indistinguishable from those seen after amino acid starvation. These results demonstrate that a decrease in cholesterol activates autophagy by a phosphatidylinositol 3-kinase-dependent mechanism.

Cheng, Jinglei [Department of Anatomy and Molecular Cell Biology, Nagoya University Graduate School of Medicine, Nagoya 466-8550 (Japan); Ohsaki, Yuki [Department of Anatomy and Molecular Cell Biology, Nagoya University Graduate School of Medicine, Nagoya 466-8550 (Japan); Tauchi-Sato, Kumi [Department of Anatomy and Molecular Cell Biology, Nagoya University Graduate School of Medicine, Nagoya 466-8550 (Japan); Fujita, Akikazu [Department of Anatomy and Molecular Cell Biology, Nagoya University Graduate School of Medicine, Nagoya 466-8550 (Japan); Fujimoto, Toyoshi [Department of Anatomy and Molecular Cell Biology, Nagoya University Graduate School of Medicine, Nagoya 466-8550 (Japan)]. E-mail: tfujimot@med.nagoya-u.ac.jp

2006-12-08

377

[Orthostatically induced epileptoid attack].  

PubMed

An epileptoid attack induced by orthostatic hypotension seen in a 72-year-old man was reported. The patient had been suffering from progressive autonomic failure with parkinsonism for six years and he had severe orthostatic hypotension, syncope and generalized convulsion when he stood up. The convulsion sometimes associated with urinary incontinence, ceased immediately when he lay down although he remained drowsy for a while. Occasionally the seizure ceased spontaneously and he regained consciousness even while he was kept standing. On lying position his blood pressure was 167/88 mmHg and no abnormality was seen in electroencephalogram. When he was tilted up to 50 degrees his blood pressure fell to 70/46 mmHg, and he became unconscious followed by jaw twitching and generalized clonic seizure. Electroencephalogram during seizure showed sharp wave and rhythmic spikes. Other laboratory examination revealed diffuse and severe autonomic dysfunction and slight cerebral atrophy on brain CT scanning. He was treated with diphenylhydantoin 300 mg/day and the seizure responded partially. The reasons why the patient's seizure was thought to be epileptic rather than the convulsive syncope were as follows: the type of the seizure was similar to an epileptic generalized convulsion, the seizure and unconsciousness ceased spontaneously even during standing position, the seizure and impaired consciousness partially responded to diphenylhydantoin administration. The underlying pathophysiology of the seizure was thought to be transient cerebral hypoperfusion induced by orthostatic hypotension. PMID:2625024

Sakakibara, R; Kita, K; Hattori, T; Hirayama, K

1989-11-01

378

[Radiation-induced neuropathy].  

PubMed

Radiation-induced neuropathy is commonly observed among oncological patients. Radiation can affect the nervous tissue directly or indirectly by inducing vasculopathy or dysfunction of internal organs. Symptoms may be mild and reversible (e.g., pain, nausea, vomiting, fever, drowsiness, fatigue, paresthesia) or life-threatening (cerebral oedema, increased intracranial pressure, seizures). Such complications are clinically divided into peripheral (plexopathies, neuropathies of spinal and cranial nerves) and central neuropathy (myelopathy, encephalopathy, cognitive impairment). The degree of neuronal damages primarily depends on the total and fractional radiation dose and applied therapeutic methods. The conformal and megavoltage radiotherapy seems to be the safeties ones. Diagnostic protocol includes physical examination, imaging (in particular magnetic resonance), electromyography, nerve conduction study and sometimes histological examination. Prevention and early detection of neurological complications are necessary in order to prevent a permanent dysfunction of the nervous system. Presently their treatment is mostly symptomatic, but in same cases a surgical intervention is required. An experimental and clinical data indicates some effectiveness of different neuroprotective agents (e.g. anticoagulants, vitamin E, hyperbaric oxygen, pentoxifylline, bevacizumab, methylphenidate, donepezil), which should be administered before and/or during radiotherapy. PMID:24490474

Kolak, Agnieszka; Staros?awska, Elzbieta; Kieszko, Dariusz; Cisek, Pawe?; Patyra, Krzysztof Ireneusz; Surdyka, Dariusz; Dobrzy?ska-Rutkowska, Aneta; ?opacka-Szatan, Karolina; Burdan, Franciszek

2013-12-01

379

INTERFERON INDUCED THYROIDITIS  

PubMed Central

Autoimmune thyroid diseases (AITD) are complex diseases that develop as a result of interactions between genetic, epigenetic, and environmental factors. Significant progress has been made in our understanding of the genetic and environmental triggers contributing to AITD. The major environmental triggers of AITD include iodine, smoking, medications, pregnancy, and possibly stress. In this review we will focus on two well-documented environmental triggers of AITD, hepatitis C virus (HCV) infection and interferon alpha (IFNa) therapy. Chronic HCV infection has been shown to be associated with increased incidence of clinical and subclinical autoimmune thyroiditis (i.e. the presence of thyroid antibodies in euthyroid subjects). Moreover, IFNa therapy of chronic HCV infection is associated with subclinical or clinical thyroiditis in up to 40% of cases which can be autoimmune, or non-autoimmune thyroiditis. In some cases interferon induced thyroiditis (IIT) in chronic HCV patients may result in severe symptomatology necessitating discontinuation of therapy. While the epidemiology and clinical presentation of HCV and interferon induced thyroiditis have been well characterized, the mechanisms causing these conditions are still poorly understood. PMID:20022216

Tomer, Yaron

2009-01-01

380

INTERFERON INDUCED THYROIDITIS  

PubMed Central

Interferon-alpha (IFN?) is used for the treatment of various disorders, most notable chronic hepatitis C virus (HCV) infection. One of the commonest side effects of IFN? therapy is thyroiditis, with up to 40% of HCV patients on IFN? developing clinical or subclinical disease. In some cases interferon induced thyroiditis (IIT) may result in severe symptomatology necessitating discontinuation of therapy. IIT can manifest as clinical autoimmune thyroiditis, presenting with symptoms of classical Hashimoto’s thyroiditis or Graves’ disease, or as non-autoimmune thyroiditis. Non-autoimmune thyroiditis can manifest as destructive thyroiditis, with early thyrotoxicosis and later hypothyroidism, or as non-autoimmune hypothyroidism. While the epidemiology and clinical presentation of IIT have been well characterized the mechanisms causing IIT are still poorly understood. It is likely that the hepatitis C virus (HCV) itself plays a role in the disease, as the association between HCV infection and thyroiditis is well established. It is believed that IFN? induces thyroiditis by both immune stimulatory effects and by direct effects on the thyroid. Early detection and therapy of this condition are important in order to avoid complications of thyroid disease such as cardiac arrhythmias. PMID:19942147

Menconi, Francesca

2009-01-01

381

Drug-Induced Hematologic Syndromes  

PubMed Central

Objective. Drugs can induce almost the entire spectrum of hematologic disorders, affecting white cells, red cells, platelets, and the coagulation system. This paper aims to emphasize the broad range of drug-induced hematological syndromes and to highlight some of the newer drugs and syndromes. Methods. Medline literature on drug-induced hematologic syndromes was reviewed. Most reports and reviews focus on individual drugs or cytopenias. Results. Drug-induced syndromes include hemolytic anemias, methemoglobinemia, red cell aplasia, sideroblastic anemia, megaloblastic anemia, polycythemia, aplastic anemia, leukocytosis, neutropenia, eosinophilia, immune thrombocytopenia, microangiopathic syndromes, hypercoagulability, hypoprothrombinemia, circulating anticoagulants, myelodysplasia, and acute leukemia. Some of the classic drugs known to cause hematologic abnormalities have been replaced by newer drugs, including biologics, accompanied by their own syndromes and unintended side effects. Conclusions. Drugs can induce toxicities spanning many hematologic syndromes, mediated by a variety of mechanisms. Physicians need to be alert to the potential for iatrogenic drug-induced hematologic complications. PMID:19960059

Mintzer, David M.; Billet, Shira N.; Chmielewski, Lauren

2009-01-01

382

Glucocorticoid-Induced Reversal of Interleukin-1?-Stimulated Inflammatory Gene Expression in Human Oviductal Cells  

PubMed Central

Studies indicate that high-grade serous ovarian carcinoma (HGSOC), the most common epithelial ovarian carcinoma histotype, originates from the fallopian tube epithelium (FTE). Risk factors for this cancer include reproductive parameters associated with lifetime ovulatory events. Ovulation is an acute inflammatory process during which the FTE is exposed to follicular fluid containing both pro- and anti-inflammatory molecules, such as interleukin-1 (IL1), tumor necrosis factor (TNF), and cortisol. Repeated exposure to inflammatory cytokines may contribute to transforming events in the FTE, with glucocorticoids exerting a protective effect. The global response of FTE cells to inflammatory cytokines or glucocorticoids has not been investigated. To examine the response of FTE cells and the ability of glucocorticoids to oppose this response, an immortalized human FTE cell line, OE-E6/E7, was treated with IL1?, dexamethasone (DEX), IL1? and DEX, or vehicle and genome-wide gene expression profiling was performed. IL1? altered the expression of 47 genes of which 17 were reversed by DEX. DEX treatment alone altered the expression of 590 genes, whereas combined DEX and IL1? treatment altered the expression of 784 genes. Network and pathway enrichment analysis indicated that many genes altered by DEX are involved in cytokine, chemokine, and cell cycle signaling, including NF?? target genes and interacting proteins. Quantitative real time RT-PCR studies validated the gene array data for IL8, IL23A, PI3 and TACC2 in OE-E6/E7 cells. Consistent with the array data, Western blot analysis showed increased levels of PTGS2 protein induced by IL1? that was blocked by DEX. A parallel experiment using primary cultured human FTE cells indicated similar effects on PTGS2, IL8, IL23A, PI3 and TACC2 transcripts. These findings support the hypothesis that pro-inflammatory signaling is induced in FTE cells by inflammatory mediators and raises the possibility that dysregulation of glucocorticoid signaling could contribute to increased risk for HGSOC. PMID:24848801

Haw, Robin; Stein, Lincoln; Brown, Theodore J.

2014-01-01

383

Sirolimus-induced angioedema.  

PubMed

Sirolimus (SRL) is a macrolide immunosuppressant that has gained widespread use in organ transplantation. Its full spectrum of side-effects is yet to be defined. We describe herein three cases of SRL-induced angioedema (AE) in African-American (AA) primary renal allograft recipients who received SRL in combination with mycophenolate mofetil and steroids. In two cases, AE manifested after SRL was restarted after a period of discontinuation. The third case presented upon initial exposure to the drug. None of the patients was receiving any drug that has been previously associated with AE. Complete resolution occurred only after SRL was withdrawn. AE has not recurred in any of the patients during a follow-up period of up to 21 months. We conclude that AE is a previously unrecognized adverse event associated with SRL use. Close monitoring for this side-effect, especially in AA patients, is warranted. PMID:15147436

Wadei, Hani; Gruber, Scott A; El-Amm, Jose M; Garnick, James; West, Miguel S; Granger, Darla K; Sillix, Dale H; Migdal, Stephen D; Haririan, Abdolreza

2004-06-01

384

Chemotherapy-induced immunosuppression.  

PubMed Central

Chemotherapeutic agents are used widely in clinical medicine for the treatment of conditions where diminution of the host immune response is a goal. The clinical use of immunosuppression is indicated for immunologically mediated disease, lymphoproliferative diseases, and prevention of graft rejection. Five categories of agents are useful for these purposes; they are ionizing irradiation, corticosteroids, biological alkylating agents, antilymphocyte sera and antimetabolites. While the specific molecular action of many of these drugs is known, how they affect cellular events in immune responses is less clear. One of the unfortunate sequelae of chemotherapy induced immunosuppression is an increased susceptibility of the host to opportunistic pathogens or malignancies. Specific methods are described for monitoring the various parameters of both humoral and cellular immunity. Studies of immunologic function in lymphoma patients and cardiac transplant patients treated with immunosuppressive drugs have shown specific defects in cell mediated immunity to herpes viruses which may relate to their increased susceptibility to infection by these agents. PMID:7037385

Rasmussen, L; Arvin, A

1982-01-01

385

Radiation-Induced Bioradicals  

NASA Astrophysics Data System (ADS)

This chapter represents the second part of a review in which the production and application of radiation-induced radicals in biological matter are discussed. In part one the general aspects of the four stages (physical, physicochemical, chemical and biological) of interaction of radiation with matter in general and biological matter in particular, were discussed. Here an overview is presented of modem technologies and theoretical methods available for studying these radiation effects. The relevance is highlighted of electron paramagnetic resonance spectroscopy and quantum chemical calculations with respect to obtaining structural information on bioradicals, and a survey is given of the research studies in this field. We also discuss some basic aspects of modem accelerator technologies which can be used for creating radicals and we conclude with an overview of applications of radiation processing in biology and related fields such as biomedical and environmental engineering, food technology, medicine and pharmacy.

Lahorte, Philippe; Mondelaers, Wim

386

Chemotherapy-induced Cardiotoxicity  

PubMed Central

ABSTRACT Breast cancer represents the most frequent form of neoplasia in women worldwide, being responsible of 1.6% of annual deaths. Therefore, it is a major public health issue and research in this field should be a priority. Chemoterapics drugs are extremly potent tools, which alone or in association to radiotherapy, increase survival and lower the reccurrence rate of cancer, but their use can be limited by cardiotoxicity. Cardiotoxicity can appear early or late after therapy, and may vary from subclinical myocardial dysfunction to irreversible heart failure. Currently, cardiac dysfunction induced by chemotherapy is diagnosed through classical echocardiographic parameters. However, these cannot detect subtle, early changes of cardiac structure and function. Consequently, description of new methods, which could detect cardiac dysfunction in an early stage, becomes essential for detecting the group of patients at risk for irreversible heart failure and for monitoring the treatment. PMID:24023601

FLORESCU, Maria; CINTEZA, Mircea; VINEREANU, Dragos

2013-01-01

387

Disorder induces explosive synchronization  

E-print Network

We study explosive synchronization, a phenomenon characterized by first-order phase transitions between incoherent and synchronized states in networks of coupled oscillators. While explosive synchronization has been the subject of many recent studies, in each case strong conditions on either the heterogeneity of the network, its link weights, or its initial construction are imposed to engineer a first-order phase transition. This raises the question of how robust explosive synchronization is in view of more realistic structural and dynamical properties. Here we show that explosive synchronization can be induced in mildly heterogeneous networks by the addition of quenched disorder to the oscillators' frequencies, demonstrating that it is not only robust to, but moreover promoted by, this natural mechanism. We support these findings with numerical and analytical results, presenting simulations of a real neural network as well as a self-consistency theory used to study synthetic networks.

Per Sebastian Skardal; Alex Arenas

2014-04-03

388

Laser-induced bioluminescence  

NASA Astrophysics Data System (ADS)

A project has been initiated to determine the feasibility of developing a complete airborne remote sensing system for rapidly mapping high concentration patches of bioluminescent organisms in the world's oceans. Conceptually, this system would be composed of a laser illuminator to induce bioluminescence and a low light level image intensifier for detection of light. Initial laboratory measurements consisted of using a 2-J flash lamp pulsed optical dye laser to excite bioluminescence in the marine dinoflagellate Pyrocustis lunula at ambient temperature using Rhodamine 6G as the lasing dye (585 nm) and a laser pulse width of 1 microsec. After a latency period of 15-20 msec, the bioluminescence maximum occurred in the blue (480 nm is the wavelength maximum for most dinoflagellate bioluminescence) with the peaking occurring approximately 65 msec after the laser pulse. Planned experiments will investigate the effect of different excitation wavelengths and energies at various temperatures and salinities of the cultures.

Hickman, G. D.; Lynch, R. V., III

1981-01-01

389

Induced seismicity. Final report  

SciTech Connect

The objective of this project has been to develop a fundamental understanding of seismicity associated with energy production. Earthquakes are known to be associated with oil, gas, and geothermal energy production. The intent is to develop physical models that predict when seismicity is likely to occur, and to determine to what extent these earthquakes can be used to infer conditions within energy reservoirs. Early work focused on earthquakes induced by oil and gas extraction. Just completed research has addressed earthquakes within geothermal fields, such as The Geysers in northern California, as well as the interactions of dilatancy, friction, and shear heating, on the generation of earthquakes. The former has involved modeling thermo- and poro-elastic effects of geothermal production and water injection. Global Positioning System (GPS) receivers are used to measure deformation associated with geothermal activity, and these measurements along with seismic data are used to test and constrain thermo-mechanical models.

Segall, P.

1997-09-18

390

Tumor-induced osteomalacia  

PubMed Central

Tumor-induced osteomalacia (TIO) is an acquired disorder of isolated renal phosphate wasting associated with tumors, typically of mesenchymal origin. Patients with TIO share similar biochemical and skeletal phenotypes with patients who have autosomal dominant hypophosphatemic rickets (ADHR) and X-linked hypophosphatemia. The study of TIO introduced the idea of the existence of circulating factors, referred to as ‘phosphatonins’, produced by the tumor, which act upon the kidney to reduce phosphate reabsorption. Although several factors have been identified, the phosphatonin FGF-23, also identified as the causative factor in ADHR, is currently the best characterized of these factors relative to phosphate handling. This review describes the importance of TIO in understanding phosphate homeostasis in the context of new endocrine interactions between the skeleton and the kidney. PMID:20228870

Farrow, Emily G; White, Kenneth E

2009-01-01

391

Herbivore induced plant volatiles  

PubMed Central

Plants respond to herbivory through different defensive mechanisms. The induction of volatile emission is one of the important and immediate response of plants to herbivory. Herbivore-induced plant volatiles (HIPVs) are involved in plant communication with natural enemies of the insect herbivores, neighboring plants, and different parts of the damaged plant. Release of a wide variety of HIPVs in response to herbivore damage and their role in plant-plant, plant-carnivore and intraplant communications represents a new facet of the complex interactions among different trophic levels. HIPVs are released from leaves, flowers, and fruits into the atmosphere or into the soil from roots in response to herbivore attack. Moreover, HIPVs act as feeding and/or oviposition deterrents to insect pests. HIPVs also mediate the interactions between the plants and the microorganisms. This review presents an overview of HIPVs emitted by plants, their role in plant defense against herbivores and their implications for pest management. PMID:22105032

War, Abdul Rashid; Sharma, Hari Chand; Paulraj, Michael Gabriel; War, Mohd Yousf; Ignacimuthu, Savarimuthu

2011-01-01

392

Aminoglycoside-induced nephrotoxicity.  

PubMed

Aminoglycosides are among the oldest antibiotics available to treat serious infections caused by primarily, Gram-negative bacteria. The most commonly utilized parenteral agents in this class include gentamicin, tobramycin and amikacin. Aminoglycosides are concentration-dependent, bactericidal agents that undergo active transport into the cell where they inhibit protein synthesis on the 30S subunit of the bacterial ribosome. As the use of aminoglycosides became more widespread, the toxic effects of these agents, most notably ototoxicity and nephrotoxicity, became more apparent. When other, safer, antimicrobial agents became available, the use of aminoglycosides sharply declined. The development of multi-drug resistance among bacteria has now lead clinicians to reexamine the role of the aminoglycosides in the treatment of serious infections. This review will revisit the mechanism and risk factors for the development of aminoglycoside-induced nephrotoxicity, as well as strategies to prevent patients from developing nephrotoxicity. PMID:25199523

Wargo, Kurt A; Edwards, Jonathan D

2014-12-01

393

Solitosynthesis induced phase transitions  

NASA Astrophysics Data System (ADS)

We consider a phase transition induced by the growth of Q-balls in a false vacuum. Such a transition could occur in the early universe in the case of broken supersymmetry with a metastable false vacuum. Small Q-balls with a negative potential energy can grow in a false vacuum by accretion of global charge until they reach critical size, expand, and cause a phase transition. We consider the growth of Q-balls from small to large, using the Bethe-Salpeter equation to describe small charge solitons and connecting to the growth of larger solitons for which the semiclassical approximation is reliable. We thus test the scenario in a simplified example inspired by supersymmetric extensions of the standard model.

Pearce, Lauren

2012-06-01

394

Malocclusion induces chronic stress.  

PubMed

We examined the effect of occlusal disharmony in senescence-accelerated (SAMP8) mice on plasma corticosterone levels, spatial learning in the water maze, fos induction, hippocampal neuron number, expression of glucocorticoid receptors (GR) and glucocorticoid receptor messenger ribonucleic acid (GRmRNA) in hippocampus and inhibitor of glucocorticoid (metyrapone). Bite-raised aged mice had significantly greater plasma corticosterone levels than age-matched control mice as well as impaired spatial memory and decreased Fos induction and a number of neurons in hippocampus. GR and GRmRNA expressions were significantly decreased in aged bite-raised mice compared with age-matched control mice. Pretreatment with metyrapone inhibited not only the bite-raised induced increase in plasma corticosterone levels, but also the reduction in the number of hippocampal neurons and impaired spatial learning. These datas suggest that the bite-raised condition may enhance the aging process in hippocampus, thereby leading to impairment of spatial memory by stress. PMID:18833910

Iinuma, Mitsuo; Ichihashi, Yukiko; Hioki, Yoko; Kurata, Chika; Tamura, Yasuo; Kubo, Kin-ya

2008-05-01

395

Radiation Induced Oral Mucositis  

PubMed Central

Patients receiving radiotherapy or chemotherapy will receive some degree of oral mucositis The incidence of oral mucositis was especially high in patients: (i) With primary tumors in the oral cavity, oropharynx, or nasopharynx; (ii) who also received concomitant chemotherapy; (iii) who received a total dose over 5,000 cGy; and (iv) who were treated with altered fractionation radiation schedules. Radiation-induced oral mucositis affects the quality of life of the patients and the family concerned. The present day management of oral mucositis is mostly palliative and or supportive care. The newer guidelines are suggesting Palifermin, which is the first active mucositis drug as well as Amifostine, for radiation protection and cryotherapy. The current management should focus more on palliative measures, such as pain management, nutritional support, and maintenance, of good oral hygiene PMID:20668585

PS, Satheesh Kumar; Balan, Anita; Sankar, Arun; Bose, Tinky

2009-01-01

396

7,8,4?-Trihydroxyisoflavone Attenuates DNCB-Induced Atopic Dermatitis-Like Symptoms in NC/Nga Mice  

PubMed Central

Atopic dermatitis (AD) is characterized by chronic highly pruritic and relapsing inflammatory skin lesions. Despite its growing prevalence, therapeutic treatments remain limited. Natural immune modulators from herbal extracts or derivatives may be useful for treating AD symptoms. This study examined the effect of 7,8,4?-trihydroxyisoflavone (7,8,4?-THIF), a metabolite of soy isoflavone daidzin, on AD-like symptoms. Repeated epicutaneous application of 2,4-dinitrochlorobenzene (DNCB) was performed on the ear and dorsal skin of NC/Nga mice to induce AD-like symptoms and skin lesions, and 7,8,4?-THIF (200 and 400 nmol) or tacrolimus (100 µg) was applied topically for 3 weeks to assess their anti-pruritic effects. We found that 7,8,4?-THIF alleviated DNCB-induced AD-like symptoms as quantified by skin lesion, dermatitis score, ear thickness, and scratching behavior. Histopathological analysis demonstrated that 7,8,4?-THIF decreased DNCB-induced eosinophil and mast cell infiltration into skin lesions. We also found that 7,8,4?-THIF significantly alleviated DNCB-induced loss of water through the epidermal layer. In addition to reducing the DNCB-induced increase in serum IgE, 7,8,4?-THIF also lowered skin lesion levels of the chemokine thymus and activation regulated chemokine; Th2 cytokines interleukin (IL)-4, IL-5, and IL-13; and Th1 cytokines IL-12 and interferon-?. These results suggest that 7,8,4?-THIF might be a potential therapeutic candidate for the treatment of atopic dermatitis. PMID:25170825

Kim, Heejung; Kim, Jong Rhan; Kang, Heerim; Choi, Jinhwan; Yang, Hee; Lee, Pomjoo; Kim, Jiyoung; Lee, Ki Won

2014-01-01

397

Intramuscular Therapeutic Vaccination Targeting HPV16 Induces T Cell Responses That Localize in Mucosal Lesions  

PubMed Central

About 25% of high-grade cervical intraepithelial neoplasias (CIN2/3) caused by human papillomavirus serotype 16 (HPV16) undergo complete spontaneous regression. However, to date, therapeutic vaccination strategies for HPV disease have yielded limited success when measured by their ability to induce robust peripheral blood T cell responses to vaccine antigen. We report marked immunologic changes in the target lesion microenvironment after intramuscular therapeutic vaccination targeting HPV16 E6/E7 antigens, in subjects with CIN2/3 who had modest detectable responses in circulating T lymphocytes. Histologic and molecular changes, including markedly (average threefold) increased intensity of CD8+ T cell infiltrates in both the stromal and epithelial compartments, suggest an effector response to vaccination. Postvaccination cervical tissue immune infiltrates included organized tertiary lymphoid-like structures in the stroma subjacent to residual intraepithelial lesions and, unlike infiltrates in unvaccinated lesions, showed evidence of proliferation induced by recognition of cognate antigen. At a molecular level, these histologic changes in the stroma were characterized by increased expression of genes associated with immune activation (CXCR3) and effector function (Tbet and IFN?), and were also associated with an immunologic signature in the overlying dysplastic epithelium. High-throughput T cell receptor sequencing of unmanipulated specimens identified clonal expansions in the tissue that were not readily detectable in peripheral blood. Together, these findings indicate that peripheral therapeutic vaccination to HPV antigens can induce a robust tissue-localized effector immune response, and that analyses of immune responses at sites of antigen are likely to be much more informative than analyses of cells that remain in the circulation. PMID:24477000

Jotova, Iveta; Wu, T. C.; Wang, Chenguang; Desmarais, Cindy; Boyer, Jean D.; Tycko, Benjamin; Robins, Harlan S.; Clark, Rachael A.; Trimble, Cornelia L.

2014-01-01

398

Intramuscular therapeutic vaccination targeting HPV16 induces T cell responses that localize in mucosal lesions.  

PubMed

About 25% of high-grade cervical intraepithelial neoplasias (CIN2/3) caused by human papillomavirus serotype 16 (HPV16) undergo complete spontaneous regression. However, to date, therapeutic vaccination strategies for HPV disease have yielded limited success when measured by their ability to