Cables1 controls p21/Cip1 protein stability by antagonizing proteasome subunit alpha type 3.

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Shi, Z; Li, Z; Li, Z J; Cheng, K; Du, Y; Fu, H; Khuri, F R

2015-05-07

The cyclin-dependent kinase (CDK) inhibitor 1A, p21/Cip1, is a vital cell cycle regulator, dysregulation of which has been associated with a large number of human malignancies. One critical mechanism that controls p21 function is through its degradation, which allows the activation of its associated cell cycle-promoting kinases, CDK2 and CDK4. Thus delineating how p21 is stabilized and degraded will enhance our understanding of cell growth control and offer a basis for potential therapeutic interventions. Here we report a novel regulatory mechanism that controls the dynamic status of p21 through its interaction with Cdk5 and Abl enzyme substrate 1 (Cables1). Cables1 has a proposed role as a tumor suppressor. We found that upregulation of Cables1 protein was correlated with increased half-life of p21 protein, which was attributed to Cables1/p21 complex formation and supported by their co-localization in the nucleus. Mechanistically, Cables1 interferes with the proteasome (Prosome, Macropain) subunit alpha type 3 (PSMA3) binding to p21 and protects p21 from PSMA3-mediated proteasomal degradation. Moreover, silencing of p21 partially reverses the ability of Cables1 to induce cell death and inhibit cell proliferation. In further support of a potential pathophysiological role of Cables1, the expression level of Cables1 is tightly associated with p21 in both cancer cell lines and human lung cancer patient tumor samples. Together, these results suggest Cables1 as a novel p21 regulator through maintaining p21 stability and support the model that the tumor-suppressive function of Cables1 occurs at least in part through enhancing the tumor-suppressive activity of p21.

Zac1, an Sp1-like protein, regulates human p21{sup WAF1/Cip1} gene expression in HeLa cells

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Liu, Pei-Yao [Graduate Institute of Life Sciences, National Defense Medical Center, Taipei 114, Taiwan, ROC (China); Hsieh, Tsai-Yuan [Division of Gastroenterology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan, ROC (China); Liu, Shu-Ting; Chang, Yung-Lung [Department of Biochemistry, National Defense Medical Center, Taipei 114, Taiwan, ROC (China); Lin, Wei-Shiang [Division of Cardiology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan, ROC (China); Wang, Wei-Ming, E-mail: ades0431@ms38.hinet.net [Graduate Institute of Life Sciences, National Defense Medical Center, Taipei 114, Taiwan, ROC (China); Department of Dermatology, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan, ROC (China); Huang, Shih-Ming, E-mail: shihming@ndmctsgh.edu.tw [Graduate Institute of Life Sciences, National Defense Medical Center, Taipei 114, Taiwan, ROC (China); Department of Biochemistry, National Defense Medical Center, Taipei 114, Taiwan, ROC (China)

2011-12-10

Zac1 functions as both a transcription factor and a transcriptional cofactor for p53, nuclear receptors (NRs) and NR coactivators. Zac1 might also act as a transcriptional repressor via the recruitment of histone deacetylase 1 (HDAC1). The ability of Zac1 to interact directly with GC-specific elements indicates that Zac1 possibly binds to Sp1-responsive elements. In the present study, our data show that Zac1 is able to interact directly with the Sp1-responsive element in the p21{sup WAF1/Cip1} gene promoter and enhance the transactivation activity of Sp1 through direct physical interaction. Our data further demonstrate that Zac1 might enhance Sp1-specific promoter activity by interacting with the Sp1-responsive element, affecting the transactivation activity of Sp1 via a protein-protein interaction, or competing the HDAC1 protein away from the pre-existing Sp1/HDAC1 complex. Finally, the synergistic regulation of p21{sup WAF1/Cip1} gene expression by Zac1 and Sp1 is mediated by endogenous p53 protein and p53-responsive elements in HeLa cells. Our work suggests that Zac1 might serve as an Sp1-like protein that directly interacts with the Sp1-responsive element to oligomerize with and/or to coactivate Sp1.

Snail regulates p21WAF/CIP1 expression in cooperation with E2 A and Twist

International Nuclear Information System (INIS)

Takahashi, Eishi; Funato, Noriko; Higashihori, Norihisa; Hata, Yuiro; Gridley, Thomas; Nakamura, Masataka

2004-01-01

Snail, a zinc-finger transcriptional repressor, is essential for mesoderm and neural crest cell formation and epithelial-mesenchymal transition. The basic helix-loop-helix transcription factors E2A and Twist have been linked with Snail during embryonic development. In this study, we examined the role of Snail in cellular differentiation through regulation of p21 WAF/CIP1 expression. A reporter assay with the p21 promoter demonstrated that Snail inhibited expression of p21 induced by E2A. Co-expression of Snail with Twist showed additive inhibitory effects. Deletion mutants of the p21 promoter revealed that sequences between -270 and -264, which formed a complex with unidentified nuclear factor(s), were critical for E2A and Snail function. The E2A-dependent expression of the endogenous p21 gene was also inhibited by Snail

DNA damage responsive miR-33b-3p promoted lung cancer cells survival and cisplatin resistance by targeting p21WAF1/CIP1.

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Xu, Shun; Huang, Haijiao; Chen, Yu-Ning; Deng, Yun-Ting; Zhang, Bing; Xiong, Xing-Dong; Yuan, Yuan; Zhu, Yanmei; Huang, Haiyong; Xie, Luoyijun; Liu, Xinguang

2016-11-01

Cisplatin is the most potent and widespread used chemotherapy drug for lung cancer treatment. However, the development of resistance to cisplatin is a major obstacle in clinical therapy. The principal mechanism of cisplatin is the induction of DNA damage, thus the capability of DNA damage response (DDR) is a key factor that influences the cisplatin sensitivity of cancer cells. Recent advances have demonstrated that miRNAs (microRNAs) exerted critical roles in DNA damage response; nonetheless, the association between DNA damage responsive miRNAs and cisplatin resistance and its underlying molecular mechanism still require further investigation. The present study has attempted to identify differentially expressed miRNAs in cisplatin induced DNA damage response in lung cancer cells, and probe into the effects of the misexpressed miRNAs on cisplatin sensitivity. Deep sequencing showed that miR-33b-3p was dramatically down-regulated in cisplatin-induced DNA damage response in A549 cells; and ectopic expression of miR-33b-3p endowed the lung cancer cells with enhanced survival and decreased γH2A.X expression level under cisplatin treatment. Consistently, silencing of miR-33b-3p in the cisplatin-resistant A549/DDP cells evidently sensitized the cells to cisplatin. Furthermore, we identified CDKN1A (p21) as a functional target of miR-33b-3p, a critical regulator of G1/S checkpoint, which potentially mediated the protection effects of miR-33b-3p against cisplatin. In aggregate, our results suggested that miR-33b-3p modulated the cisplatin sensitivity of cancer cells might probably through impairing the DNA damage response. And the knowledge of the drug resistance conferred by miR-33b-3p has great clinical implications for improving the efficacy of chemotherapies for treating lung cancers.

Estudo de p27, p21, p16 em epitélio escamoso normal, papiloma escamoso e carcinoma de células escamosas da cavidade oral Comparative analysis of the immunohistochemistry expression of p27, p21WAF/Cip1, and p16INK4a in oral normal epithelium, squamous papilloma and squamous cell carcinoma

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Ana Beatriz Piazza Queiroz

2009-12-01

Full Text Available INTRODUÇÃO E OBJETIVO: O tipo de câncer oral mais frequente é o carcinoma de células escamosas, que corresponde a 95% dos casos(9. O papiloma escamoso oral é uma neoplasia benigna normalmente associada à infecção pelo papilomavírus humano (HPV(21. A análise da literatura mostra alterações nos genes reguladores do ciclo celular p27, p21WAF/Cip1 e p16INK4a, porém sem uma definição de seus papéis na carcinogênese oral. O objetivo foi caracterizar imuno-histoquimicamente p27, p21WAF/Cip1 e p16NK4a em epitélio escamoso normal, papilomas escamosos e carcinomas de células escamosas da cavidade oral. MÉTODOS: Imuno-histoquímica para p27, p21WAF/Cip1 e p16NK4a em 32 casos de epitélio escamoso normal, 30 casos de papiloma escamoso e 34 de carcinoma de células escamosas da cavidade oral. RESULTADOS: p27: 97,06% dos casos de carcinoma de células escamosas apresentaram imunopositividade focal. O grupo papiloma escamoso apresentou 33,33% e o grupo controle, 18,75%. p21WAF/Cip1: 100% de imunopositividade focal tanto no grupo controle como no grupo carcinoma de células escamosas, e 90% no grupo papiloma escamoso. p16INK4a: 100% de imunopositividade focal para os grupos controle e papiloma escamoso, e 94% para o grupo carcinoma de células escamosas. CONCLUSÃO: Imuno-histoquimicamente demonstrou-se diferença significativa para p27 quando feita comparação dos grupos controle e papiloma escamoso com o grupo carcinoma de células escamosas. O p21WAF/Cip1 não demonstrou poder de diferenciar os grupos analisados. O p16INK4a apresentou imunopositividade difusa em uma minoria dos casos do grupo carcinoma de células escamosas. O grupo papiloma escamoso se comportou de maneira similar ao grupo controle em relação aos três marcadores.INTRODUCTION: The most frequent type of oral cancer is the squamous cell carcinoma, which corresponds to 95% of the cases(9.The oral squamous papilloma is a benign neoplasia, commonly associated with

Cloning of the rat Waf1/Cip1 gene

International Nuclear Information System (INIS)

Belinsky, S.A.; Middleton, S.K.

1994-01-01

The progression of eukaryotic cells through the cell cycle involves the sequential expression of specific genes. This process is regulated by both external and internal stimuli that prevent the cell from prematurely entering the next phase before all macromolecular events have been completed. The activation and subsequent inactivation of cyclin dependent kinases (Cdks) represent one internal stimuli required to regulate the transit of cells from one stage of the cell cycle to the next. Another member of this regulatory cascade is the p53 tumor suppressor gene, which controls a G 1 checkpoint at which the cell cycle can be arrested prior to the initiation of DNA synthesis. Following DNA damage, p53 protein levels rise, and entry into S phase is delayed, presumably to allow time for repair of the lesions. When p53 function is lost, cells containing damaged DNA template enter S phase leading to fixation and propagation of genetic alterations. Recently, evidence linking the growth-suppressing activity of p53 and inactivation of Cdks has been provided by the cloning of the Waf1/Cip1 gene. Waf1/Cip1 encodes a protein of M r 21,000 (p21), which inhibits Cdks in vitro. The overexpression of Waf1/Cip1 in cells inhibits cell growth, suggesting that p21 is a downstream mediator of p53 function. Loss of Waf1/Cip1 gene function could lead to deregulation of the cell cycle and contribute to the development of the neoplastic phenotype in tumors that do not contain mutations in the p53 gene. The purpose of the present investigation was to clone the rat Waf1/Cip1 gene,then determine the frequency for alteration of this gene in lung tumors induced by X-rays

The Forkhead Transcription Factor FOXP2 Is Required for Regulation of p21WAF1/CIP1 in 143B Osteosarcoma Cell Growth Arrest.

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Gascoyne, Duncan M; Spearman, Hayley; Lyne, Linden; Puliyadi, Rathi; Perez-Alcantara, Marta; Coulton, Les; Fisher, Simon E; Croucher, Peter I; Banham, Alison H

2015-01-01

Mutations of the forkhead transcription factor FOXP2 gene have been implicated in inherited speech-and-language disorders, and specific Foxp2 expression patterns in neuronal populations and neuronal phenotypes arising from Foxp2 disruption have been described. However, molecular functions of FOXP2 are not completely understood. Here we report a requirement for FOXP2 in growth arrest of the osteosarcoma cell line 143B. We observed endogenous expression of this transcription factor both transiently in normally developing murine osteoblasts and constitutively in human SAOS-2 osteosarcoma cells blocked in early osteoblast development. Critically, we demonstrate that in 143B osteosarcoma cells with minimal endogenous expression, FOXP2 induced by growth arrest is required for up-regulation of p21WAF1/CIP1. Upon growth factor withdrawal, FOXP2 induction occurs rapidly and precedes p21WAF1/CIP1 activation. Additionally, FOXP2 expression could be induced by MAPK pathway inhibition in growth-arrested 143B cells, but not in traditional cell line models of osteoblast differentiation (MG-63, C2C12, MC3T3-E1). Our data are consistent with a model in which transient upregulation of Foxp2 in pre-osteoblast mesenchymal cells regulates a p21-dependent growth arrest checkpoint, which may have implications for normal mesenchymal and osteosarcoma biology.

Translational Upregulation of an Individual p21Cip1 Transcript Variant by GCN2 Regulates Cell Proliferation and Survival under Nutrient Stress.

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Stacey L Lehman

2015-06-01

Full Text Available Multiple transcripts encode for the cell cycle inhibitor p21(Cip1. These transcripts produce identical proteins but differ in their 5' untranslated regions (UTRs. Although several stresses that induce p21 have been characterized, the mechanisms regulating the individual transcript variants and their functional significance are unknown. Here we demonstrate through (35S labeling, luciferase reporter assays, and polysome transcript profiling that activation of the Integrated Stress Response (ISR kinase GCN2 selectively upregulates the translation of a p21 transcript variant containing 5' upstream open reading frames (uORFs through phosphorylation of the eukaryotic translation initiation factor eIF2α. Mutational analysis reveals that the uORFs suppress translation under basal conditions, but promote translation under stress. Functionally, ablation of p21 ameliorates G1/S arrest and reduces cell survival in response to GCN2 activation. These findings uncover a novel mechanism of p21 post-transcriptional regulation, offer functional significance for the existence of multiple p21 transcripts, and support a key role for GCN2 in regulating the cell cycle under stress.

Down-regulation of p21 (CDKN1A/CIP1) is inversely associated with microsatellite instability and CpG island methylator phenotype (CIMP) in colorectal cancer.

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Ogino, S; Kawasaki, T; Kirkner, G J; Ogawa, A; Dorfman, I; Loda, M; Fuchs, C S

2006-10-01

p21 (CDKN1A/CIP1/WAF1), one of the cyclin-dependent kinase inhibitors, plays a key role in regulating the cell cycle and is transcriptionally regulated by p53. Down-regulation of p21 is caused by TP53 mutations in colorectal cancer. CpG island methylator phenotype (CIMP) appears to be a distinct subtype of colorectal cancer with concordant methylation of multiple gene promoters and is associated with a high degree of microsatellite instability (MSI-H) and BRAF mutations. However, no study to date has evaluated the relationship between p21 expression and CIMP in colorectal cancer. The purpose of this study was to examine the inter-relationships between p21, p53, CIMP, MSI and KRAS/BRAF status in colorectal cancer. We utilized 737 relatively unbiased samples of colorectal cancers from two large prospective cohort studies. Using quantitative real-time PCR (MethyLight), we measured DNA methylation in five CIMP-specific gene promoters [CACNA1G, CDKN2A (p16/INK4A), CRABP1, MLH1 and NEUROG1]. CIMP-high (>or=4/5 methylated promoters) was diagnosed in 118 (16%) of the 737 tumours. We also assessed expression of p21 and p53 by immunohistochemistry. Among the 737 tumours, 371 (50%) showed p21 loss. Both p21 loss and p53 positivity were inversely associated with CIMP-high, MSI-H and BRAF mutations. The associations of p21 with these molecular features were still present after tumours were stratified by p53 status. In contrast, the associations of p53 positivity with the molecular features were no longer present after tumours were stratified by p21 status. When CIMP-high and non-CIMP-high tumours were stratified by MSI or KRAS/BRAF status, CIMP-high and MSI-H (but not BRAF mutations) were still inversely associated with p21 loss. In conclusion, down-regulation of p21 is inversely correlated with CIMP-high and MSI-H in colorectal cancer, independent of TP53 and BRAF status.

S-phase Specific Downregulation of Human O6-Methylguanine DNA Methyltransferase (MGMT and its Serendipitous Interactions with PCNA and p21cip1 Proteins in Glioma Cells

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AGM Mostofa

2018-04-01

Full Text Available Whether the antimutagenic DNA repair protein MGMT works solo in human cells and if it has other cellular functions is not known. Here, we show that human MGMT associates with PCNA and in turn, with the cell cycle inhibitor, p21cip1 in glioblastoma and other cancer cell lines. MGMT protein was shown to harbor a nearly perfect PCNA-Interacting Protein (PIP box motif. Isogenic p53-null H1299 cells were engineered to express the p21 protein by two different procedures. Reciprocal immunoprecipitation/western blotting, Far-western blotting, and confocal microscopy confirmed the specific association of MGMT with PCNA and the ability of p21 to strongly disrupt the MGMT-PCNA complexes in tumor cells. Alkylation DNA damage resulted in a greater colocalization of MGMT and PCNA proteins, particularly in HCT116 cells deficient in p21 expression. p21 expression in isogenic cell lines directly correlated with markedly higher levels of MGMT mRNA, protein, activity and greater resistance to alkylating agents. In other experiments, four glioblastoma cell lines synchronized at the G1/S phase using either double thymidine or thymidine-mimosine blocks and subsequent cycling consistently showed a loss of MGMT protein at mid- to late S-phase, irrespective of the cell line, suggesting such a downregulation is fundamental to cell cycle control. MGMT protein was also specifically degraded in extracts from S-phase cells and evidence strongly suggested the involvement of PCNA-dependent CRL4Cdt2 ubiquitin-ligase in the reaction. Overall, these data provide the first evidence for non-repair functions of MGMT in cell cycle and highlight the involvement of PCNA in MGMT downregulation, with p21 attenuating the process.

Expression of proteins FGFR3, PI3K, AKT, p21Waf1/Cip1 and cyclins D1 and D3 in patients with T1 bladder tumours: clinical implications and prognostic significance.

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Blanca Pedregosa, A M; Sánchez-González, Á; Carrasco Valiente, J; Ruiz García, J M; Gómez Gómez, E; López Beltrán, A; Requena Tapia, M J

2017-04-01

To determine the differential protein expression of biomarkers FGFR3, PI3K (subunits PI3Kp110α, PI3KClassIII, PI3Kp85), AKT, p21Waf1/Cip1 and cyclins D1 and D3 in T1 bladder cancer versus healthy tissue and to study their potential role as early recurrence markers. This is a prospective study that employed a total of 67 tissue samples (55 cases of T1 bladder tumours that underwent transurethral resection and 12 cases of adjacent healthy mucosa). The protein expression levels were assessed using Western blot, and the means and percentages were compared using Student's t-test and the chi-squared test. The survival analysis was conducted using the Kaplan-Meier method and the log-rank test. Greater protein expression was detected for FGFR3, PI3Kp110α, PI3KClassIII, cyclins D1 and D3 and p21Waf1/Cip1 in the tumour tissue than in the healthy mucosa. However, these differences were not significant for PI3Kp85 and AKT. We observed statistically significant correlations between early recurrence and PI3Kp110α, PI3KClassIII, PI3Kp85 and AKT (P=.003, P=.045, P=.050 and P=.028, respectively), between the tumour type (primary vs. recurrence) and cyclin D3 (P=.001), between the tumour size and FGFR3 (P=.035) and between multifocality and cyclin D1 (P=.039). The survival analysis selected FGFR3 (P=.024), PI3Kp110α (P=.014), PI3KClassIII (P=.042) and AKT (P=.008) as markers of early-recurrence-free survival. There is an increase in protein expression levels in bladder tumour tissue. The overexpression of FGFR3, PI3Kp110α, PI3KClassIII and AKT is associated with increased early-recurrence-free survival for patients with T1 bladder tumours. Copyright © 2016 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

Pharmacologic ATM but not ATR kinase inhibition abrogates p21-dependent G1 arrest and promotes gastrointestinal syndrome after total body irradiation.

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Vendetti, Frank P; Leibowitz, Brian J; Barnes, Jennifer; Schamus, Sandy; Kiesel, Brian F; Abberbock, Shira; Conrads, Thomas; Clump, David Andy; Cadogan, Elaine; O'Connor, Mark J; Yu, Jian; Beumer, Jan H; Bakkenist, Christopher J

2017-02-01

We show that ATM kinase inhibition using AZ31 prior to 9 or 9.25 Gy total body irradiation (TBI) reduced median time to moribund in mice to 8 days. ATR kinase inhibition using AZD6738 prior to TBI did not reduce median time to moribund. The striking finding associated with ATM inhibition prior to TBI was increased crypt loss within the intestine epithelium. ATM inhibition reduced upregulation of p21, an inhibitor of cyclin-dependent kinases, and blocked G1 arrest after TBI thereby increasing the number of S phase cells in crypts in wild-type but not Cdkn1a(p21 CIP/WAF1 )-/- mice. In contrast, ATR inhibition increased upregulation of p21 after TBI. Thus, ATM activity is essential for p21-dependent arrest while ATR inhibition may potentiate arrest in crypt cells after TBI. Nevertheless, ATM inhibition reduced median time to moribund in Cdkn1a(p21 CIP/WAF1 )-/- mice after TBI. ATM inhibition also increased cell death in crypts at 4 h in Cdkn1a(p21 CIP/WAF1 )-/-, earlier than at 24 h in wild-type mice after TBI. In contrast, ATR inhibition decreased cell death in crypts in Cdkn1a(p21 CIP/WAF1 )-/- mice at 4 h after TBI. We conclude that ATM activity is essential for p21-dependent and p21-independent mechanisms that radioprotect intestinal crypts and that ATM inhibition promotes GI syndrome after TBI.

Correlation Among Six Biologic Factors (p53, p21WAF1, MIB-1, EGFR, HER2, and Bcl-2) and Clinical Outcomes After Curative Chemoradiation Therapy in Squamous Cell Cervical Cancer

International Nuclear Information System (INIS)

Yamashita, Hideomi; Murakami, Naoya; Asari, Takao; Okuma, Kae; Ohtomo, Kuni; Nakagawa, Keiichi

2009-01-01

Purpose: The expressions of six cell-cycle-associated proteins were analyzed in cervical squamous cell carcinomas in correlation in a search for prognostic correlations in tumors treated with concurrent chemoradiation therapy (cCRT). Methods and Materials: The expressions of p53, p21/waf1/cip1, molecular immunology borstel-1 (MIB-1), epidermal growth factor receptor (EGFR), human epidermal growth factor receptor type 2 (HER2), and Bcl-2 were studied using an immunohistochemical method in 57 cases of cervical squamous cell carcinoma treated with cCRT. Patients received cCRT between 1998 and 2005. The mean patient age was 61 years (range, 27-82 years). The number of patients with Stage II, III, and IVA disease was 18, 29, and 10, respectively. Results: The number of patients with tumors positive for p53, p21/waf1/cip1, MIB-1, EGFR, HER2, and Bcl-2 was 26, 24, 49, 26, 13, and 11, respectively; no significant correlation was noted. The 5-year overall survival rates of HER2-positive and -negative patients was 76% vs. 44%, which was of borderline significance (p = 0.0675). No significant correlation was noted between overall survival and expressions of p53, p21/waf1/cip1, MIB-1, EGFR, and Bcl-2. No correlation was observed between local control and expression of any of the proteins. Conclusion: Expression of HER2 protein had a weak impact of borderline significance on overall survival in squamous cell carcinoma of the uterine cervix treated with cCRT. However, no clinical associations could be established for p53, p21/waf1/cip1, MIB-1, EGFR, and Bcl-2 protein expressions.

Chronic p53-independent p21 expression causes genomic instability by deregulating replication licensing

DEFF Research Database (Denmark)

Galanos, Panagiotis; Vougas, Konstantinos; Walter, David

2016-01-01

The cyclin-dependent kinase inhibitor p21(WAF1/CIP1) (p21) is a cell-cycle checkpoint effector and inducer of senescence, regulated by p53. Yet, evidence suggests that p21 could also be oncogenic, through a mechanism that has so far remained obscure. We report that a subset of atypical cancerous ...

Eukaryotic translation initiator protein 1A isoform, CCS-3, enhances the transcriptional repression of p21CIP1 by proto-oncogene FBI-1 (Pokemon/ZBTB7A).

Science.gov (United States)

Choi, Won-Il; Kim, Youngsoo; Kim, Yuri; Yu, Mi-young; Park, Jungeun; Lee, Choong-Eun; Jeon, Bu-Nam; Koh, Dong-In; Hur, Man-Wook

2009-01-01

FBI-1, a member of the POK (POZ and Kruppel) family of transcription factors, plays a role in differentiation, oncogenesis, and adipogenesis. eEF1A is a eukaryotic translation elongation factor involved in several cellular processes including embryogenesis, oncogenic transformation, cell proliferation, and cytoskeletal organization. CCS-3, a potential cervical cancer suppressor, is an isoform of eEF1A. We found that eEF1A forms a complex with FBI-1 by co-immunoprecipitation, SDS-PAGE, and MALDI-TOF Mass analysis of the immunoprecipitate. GST fusion protein pull-downs showed that FBI-1 directly interacts with eEF1A and CCS-3 via the zinc finger and POZ-domain of FBI-1. FBI-1 co-localizes with either eEF1A or CCS-3 at the nuclear periplasm. CCS-3 enhances transcriptional repression of the p21CIP1 gene (hereafter referred to as p21) by FBI-1. The POZ-domain of FBI-1 interacts with the co-repressors, SMRT and BCoR. We found that CCS-3 also interacts with the co-repressors independently. The molecular interaction between the co-repressors and CCS-3 at the POZ-domain of FBI-1 appears to enhance FBI-1 mediated transcriptional repression. Our data suggest that CCS-3 may be important in cell differentiation, tumorigenesis, and oncogenesis by interacting with the proto-oncogene FBI-1 and transcriptional co-repressors. Copyright 2009 S. Karger AG, Basel.

The maternal genes Ci-p53/p73-a and Ci-p53/p73-b regulate zygotic ZicL expression and notochord differentiation in Ciona intestinalis embryos.

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Noda, Takeshi

2011-12-01

I isolated a Ciona intestinalis homolog of p53, Ci-p53/p73-a, in a microarray screen of rapidly degraded maternal mRNA by comparing the transcriptomes of unfertilized eggs and 32-cell stage embryos. Higher expression of the gene in eggs and lower expression in later embryonic stages were confirmed by whole-mount in situ hybridization (WISH) and quantitative reverse transcription-PCR (qRT-PCR); expression was ubiquitous in eggs and early embryos. Knockdown of Ci-p53/p73-a by injection of antisense morpholino oligonucleotides (MOs) severely perturbed gastrulation cell movements and expression of notochord marker genes. A key regulator of notochord differentiation in Ciona embryos is Brachyury (Ci-Bra), which is directly activated by a zic-like gene (Ci-ZicL). The expression of Ci-ZicL and Ci-Bra in A-line notochord precursors was downregulated in Ci-p53/p73-a knockdown embryos. Maternal expression of Ci-p53/p73-b, a homolog of Ci-p53/p73-a, was also detected. In Ci-p53/p73-b knockdown embryos, gastrulation cell movements, expression of Ci-ZicL and Ci-Bra in A-line notochord precursors, and expression of notochord marker gene at later stages were perturbed. The upstream region of Ci-ZicL contains putative p53-binding sites. Cis-regulatory analysis of Ci-ZicL showed that these sites are involved in expression of Ci-ZicL in A-line notochord precursors at the 32-cell and early gastrula stages. These results suggest that p53 genes are maternal factors that play a crucial role in A-line notochord differentiation in C. intestinalis embryos by regulating Ci-ZicL expression. Copyright © 2011 Elsevier Inc. All rights reserved.

Development of mice without Cip/Kip CDK inhibitors

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Tateishi, Yuki; Matsumoto, Akinobu; Kanie, Tomoharu [Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582 (Japan); CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); Hara, Eiji [Cancer Institute, Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo 135-8550 (Japan); Nakayama, Keiko [Department of Developmental Genetics, Center for Translational and Advanced Animal Research, Graduate School of Medicine, Tohoku University, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575 (Japan); Nakayama, Keiichi I., E-mail: nakayak1@bioreg.kyushu-u.ac.jp [Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582 (Japan); CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan)

2012-10-19

Highlights: Black-Right-Pointing-Pointer Mice lacking Cip/Kip CKIs (p21, p27, and p57) survive until embryonic day 13.5. Black-Right-Pointing-Pointer Proliferation of MEFs lacking all three Cip/Kip CKIs appears unexpectedly normal. Black-Right-Pointing-Pointer CDK2 kinase activity of the triple mutant MEFs is increased in G0 phase. -- Abstract: Timely exit of cells from the cell cycle is essential for proper cell differentiation during embryogenesis. Cyclin-dependent kinase (CDK) inhibitors (CKIs) of the Cip/Kip family (p21, p27, and p57) are negative regulators of cell cycle progression and are thought to be essential for development. However, the extent of functional redundancy among Cip/Kip family members has remained largely unknown. We have now generated mice that lack all three Cip/Kip CKIs (TKO mice) and compared them with those lacking each possible pair of these proteins (DKO mice). We found that the TKO embryos develop normally until midgestation but die around embryonic day (E) 13.5, slightly earlier than p27/p57 DKO embryos. The TKO embryos manifested morphological abnormalities as well as increased rates of cell proliferation and apoptosis in the placenta and lens that were essentially indistinguishable from those of p27/p57 DKO mice. Unexpectedly, the proliferation rate and cell cycle profile of mouse embryonic fibroblasts (MEFs) lacking all three Cip/Kip CKIs did not differ substantially from those of control MEFs. The abundance and kinase activity of CDK2 were markedly increased, whereas CDK4 activity and cyclin D1 abundance were decreased, in both p27/p57 DKO and TKO MEFs during progression from G{sub 0} to S phase compared with those in control MEFs. The extents of the increase in CDK2 activity and the decrease in CDK4 activity and cyclin D1 abundance were greater in TKO MEFs than in p27/p57 DKO MEFs. These results suggest that p27 and p57 play an essential role in mouse development after midgestation, and that p21 plays only an auxiliary role in

Cytoplasmic p21 is a potential predictor for cisplatin sensitivity in ovarian cancer

International Nuclear Information System (INIS)

Xia, Xi; Weng, Yanjie; Liao, Shujie; Han, Zhiqiang; Liu, Ronghua; Zhu, Tao; Wang, Shixuan; Xu, Gang; Meng, Li; Zhou, Jianfeng; Ma, Ding; Ma, Quanfu; Li, Xiao; Ji, Teng; Chen, Pingbo; Xu, Hongbin; Li, Kezhen; Fang, Yong; Weng, Danhui

2011-01-01

P21 (WAF1/Cip1) binds to cyclin-dependent kinase complexes and inhibits their activities. It was originally described as an inhibitor of cancer cell proliferation. However, many recent studies have shown that p21 promotes tumor progression when accumulated in the cell cytoplasm. So far, little is known about the correlation between cytoplasmic p21 and drug resistance. This study was aimed to investigate the role of p21 in the cisplatin resistance of ovarian cancer. RT-PCR, western blot and immunofluorescence were used to detect p21 expression and location in cisplatin-resistant ovarian cancer cell line C13* and its parental line OV2008. Regulation of cytoplasmic p21 was performed through transfection of p21 siRNA, Akt2 shRNA and Akt2 constitutively active vector in the two cell lines; their effects on cisplatin-induced apoptosis were evaluated by flow cytometry. Tumor tissue sections of clinical samples were analyzed by immunohistochemistry. p21 predominantly localizes to the cytoplasm in C13* compared to OV2008. Persistent exposure to low dose cisplatin in OV2008 leads to p21 translocation from nuclear to cytoplasm, while it had not impact on p21 localization in C13*. Knockdown of cytoplasmic p21 by p21 siRNA transfection in C13* notably increased cisplatin-induced apoptosis through activation of caspase 3. Inhibition of p21 translocation into the cytoplasm by transfection of Akt2 shRNA into C13* cells significantly increased cisplatin-induced apoptosis, while induction of p21 translocation into the cytoplasm by transfection of constitutively active Akt2 in OV2008 enhanced the resistance to cisplatin. Immunohistochemical analysis of clinical ovarian tumor tissues demonstrated that cytoplasmic p21 was negatively correlated with the response to cisplatin based treatment. Cytoplasmic p21 is a novel biomarker of cisplatin resistance and it may represent a potential therapeutic target for ovarian tumors that are refractory to conventional treatment

The rice XA21 ectodomain fused to the Arabidopsis EFR cytoplasmic domain confers resistance to Xanthomonas oryzae pv. oryzae.

Science.gov (United States)

Thomas, Nicholas C; Oksenberg, Nir; Liu, Furong; Caddell, Daniel; Nalyvayko, Alina; Nguyen, Yen; Schwessinger, Benjamin; Ronald, Pamela C

2018-01-01

Rice ( Oryza sativa ) plants expressing the XA21 cell-surface receptor kinase are resistant to Xanthomonas oryzae pv. oryzae (Xoo) infection. We previously demonstrated that expressing a chimeric protein containing the ELONGATION FACTOR Tu RECEPTOR (EFR) ectodomain and the XA21 endodomain (EFR:XA21) in rice does not confer robust resistance to Xoo . To test if the XA21 ectodomain is required for Xoo resistance, we produced transgenic rice lines expressing a chimeric protein consisting of the XA21 ectodomain and EFR endodomain (XA21:EFR) and inoculated these lines with Xoo . We also tested if the XA21:EFR rice plants respond to a synthetic sulfated 21 amino acid derivative (RaxX21-sY) of the activator of XA21-mediated immunity, RaxX. We found that five independently transformed XA21:EFR rice lines displayed resistance to Xoo as measured by lesion length analysis, and showed that five lines share characteristic markers of the XA21 defense response (generation of reactive oxygen species and defense response gene expression) after treatment with RaxX21-sY. Our results indicate that expression of the XA21:EFR chimeric receptor in rice confers resistance to Xoo . These results suggest that the endodomain of the EFR and XA21 immune receptors are interchangeable and the XA21 ectodomain is the key determinant conferring robust resistance to Xoo .

Resveratrol mediated cell death in cigarette smoke transformed breast epithelial cells is through induction of p21Waf1/Cip1 and inhibition of long patch base excision repair pathway

Energy Technology Data Exchange (ETDEWEB)

Mohapatra, Purusottam; Satapathy, Shakti Ranjan; Das, Dipon; Siddharth, Sumit [Cancer Biology Division, KIIT School of Biotechnology, KIIT University, Campus-11, Patia, Bhubaneswar, Orissa 751024 (India); Choudhuri, Tathagata [Institute of Life Sciences, Nalco Square, Bhubaneswar, Orissa 751023 (India); Department of Biotechnology, Visva Bharati University, Santiniketan, West Bengal (India); Kundu, Chanakya Nath, E-mail: cnkundu@gmail.com [Cancer Biology Division, KIIT School of Biotechnology, KIIT University, Campus-11, Patia, Bhubaneswar, Orissa 751024 (India)

2014-03-15

Cigarette smoking is a key factor for the development and progression of different cancers including mammary tumor in women. Resveratrol (Res) is a promising natural chemotherapeutic agent that regulates many cellular targets including p21, a cip/kip family of cyclin kinase inhibitors involved in DNA damage-induced cell cycle arrest and blocking of DNA replication and repair. We have recently shown that cigarette smoke condensate (CSC) prepared from commercially available Indian cigarette can cause neoplastic transformation of normal breast epithelial MCF-10A cell. Here we studied the mechanism of Res mediated apoptosis in CSC transformed (MCF-10A-Tr) cells in vitro and in vivo. Res mediated apoptosis in MCF-10A-Tr cells was a p21 dependent event. It increased the p21 protein expression in MCF-10A-Tr cells and MCF-10A-Tr cells-mediated tumors in xenograft mice. Res treatment reduced the tumor size(s) and expression of anti-apoptotic proteins (e.g. PI3K, AKT, NFκB) in solid tumor. The expressions of cell cycle regulatory (Cyclins, CDC-2, CDC-6, etc.), BER associated (Pol-β, Pol-δ, Pol-ε, Pol-η, RPA, Fen-1, DNA-Ligase-I, etc.) proteins and LP-BER activity decreased in MCF-10A-Tr cells but remain significantly unaltered in isogenic p21 null MCF-10A-Tr cells after Res treatment. Interestingly, no significant changes were noted in SP-BER activity in both the cell lines after Res exposure. Finally, it was observed that increased p21 blocks the LP-BER in MCF-10A-Tr cells by increasing its interaction with PCNA via competing with Fen-1 after Res treatment. Thus, Res caused apoptosis in CSC-induced cancer cells by reduction of LP-BER activity and this phenomenon largely depends on p21. - Highlights: • Resveratrol (Res) caused reduction of MCF-10A-Tr cell growth by inducing apoptosis. • Res caused cell cycle arrest and DNA damage in p21 dependent manner. • Res mediated LP-BER reduction in MCF-10A-Tr cells was a p21 dependent phenomenon. • Res inhibits BER and PI

Resveratrol mediated cell death in cigarette smoke transformed breast epithelial cells is through induction of p21Waf1/Cip1 and inhibition of long patch base excision repair pathway

International Nuclear Information System (INIS)

Mohapatra, Purusottam; Satapathy, Shakti Ranjan; Das, Dipon; Siddharth, Sumit; Choudhuri, Tathagata; Kundu, Chanakya Nath

2014-01-01

Cigarette smoking is a key factor for the development and progression of different cancers including mammary tumor in women. Resveratrol (Res) is a promising natural chemotherapeutic agent that regulates many cellular targets including p21, a cip/kip family of cyclin kinase inhibitors involved in DNA damage-induced cell cycle arrest and blocking of DNA replication and repair. We have recently shown that cigarette smoke condensate (CSC) prepared from commercially available Indian cigarette can cause neoplastic transformation of normal breast epithelial MCF-10A cell. Here we studied the mechanism of Res mediated apoptosis in CSC transformed (MCF-10A-Tr) cells in vitro and in vivo. Res mediated apoptosis in MCF-10A-Tr cells was a p21 dependent event. It increased the p21 protein expression in MCF-10A-Tr cells and MCF-10A-Tr cells-mediated tumors in xenograft mice. Res treatment reduced the tumor size(s) and expression of anti-apoptotic proteins (e.g. PI3K, AKT, NFκB) in solid tumor. The expressions of cell cycle regulatory (Cyclins, CDC-2, CDC-6, etc.), BER associated (Pol-β, Pol-δ, Pol-ε, Pol-η, RPA, Fen-1, DNA-Ligase-I, etc.) proteins and LP-BER activity decreased in MCF-10A-Tr cells but remain significantly unaltered in isogenic p21 null MCF-10A-Tr cells after Res treatment. Interestingly, no significant changes were noted in SP-BER activity in both the cell lines after Res exposure. Finally, it was observed that increased p21 blocks the LP-BER in MCF-10A-Tr cells by increasing its interaction with PCNA via competing with Fen-1 after Res treatment. Thus, Res caused apoptosis in CSC-induced cancer cells by reduction of LP-BER activity and this phenomenon largely depends on p21. - Highlights: • Resveratrol (Res) caused reduction of MCF-10A-Tr cell growth by inducing apoptosis. • Res caused cell cycle arrest and DNA damage in p21 dependent manner. • Res mediated LP-BER reduction in MCF-10A-Tr cells was a p21 dependent phenomenon. • Res inhibits BER and PI

Individual variation in p53 and Cip1 expression profiles in normal human fibroblast strains following exposure to high-let radiation

Energy Technology Data Exchange (ETDEWEB)

Carpenter, T.R.; Johnson, N.F.; Gilliland, F.D. [Univ. of New Mexico, Albuquerque, NM (United States)] [and others

1995-12-01

Exposure to {alpha}-particles emitted by radon progeny appears to be the second-leading cause of lung cancer mortality. However, individual susceptibility to the carcinogenic effects of {alpha}-particles remains poorly characterized. Variation in susceptibility to cancer produced by certian classes of DNA-damaging chemicals is suspected to involve differences in metabolic activation and detoxication. Susceptibility to {alpha}-particle-induced cancer may involve variations in capacity or opportunity to repair DNA damage. Subtle variations in DNA repair capacity would more likely explain radon-related lung cancer susceptibility. The p53 tumor suppressor protein accumulates as a cellular response to DNA damage from ionizing radiation and regulates arrest in the G{sub 1} portion of the cell cycle. Arrest in G{sub 1} portion of the cell cycle. While upstream regulation of p53 protein stability is poorly understood, variations in the ability to accumulate p53 following DNA damage represent potential variations in lung cancer susceptibility related to radon progeny. Further, transcription of the cell-cycle regulatory gene Cip1 is regulated by p53 and increases following ionizing radiation. Therefore, variations in the expression of Cip1 following {alpha}-particle exposure may also be a susceptibility factor in radon-related lung cancers. The purpose of the present investigation was to measure p53 and Cip1 protein induction following {alpha}-particle exposure of fibroblast lines from nine individuals to determine if there were significant variations. The expression of Cip1 protein indicates the differences in response are biologically relevant.

Individual variation in p53 and Cip1 expression profiles in normal human fibroblast strains following exposure to high-let radiation

International Nuclear Information System (INIS)

Carpenter, T.R.; Johnson, N.F.; Gilliland, F.D.

1995-01-01

Exposure to α-particles emitted by radon progeny appears to be the second-leading cause of lung cancer mortality. However, individual susceptibility to the carcinogenic effects of α-particles remains poorly characterized. Variation in susceptibility to cancer produced by certian classes of DNA-damaging chemicals is suspected to involve differences in metabolic activation and detoxication. Susceptibility to α-particle-induced cancer may involve variations in capacity or opportunity to repair DNA damage. Subtle variations in DNA repair capacity would more likely explain radon-related lung cancer susceptibility. The p53 tumor suppressor protein accumulates as a cellular response to DNA damage from ionizing radiation and regulates arrest in the G 1 portion of the cell cycle. Arrest in G 1 portion of the cell cycle. While upstream regulation of p53 protein stability is poorly understood, variations in the ability to accumulate p53 following DNA damage represent potential variations in lung cancer susceptibility related to radon progeny. Further, transcription of the cell-cycle regulatory gene Cip1 is regulated by p53 and increases following ionizing radiation. Therefore, variations in the expression of Cip1 following α-particle exposure may also be a susceptibility factor in radon-related lung cancers. The purpose of the present investigation was to measure p53 and Cip1 protein induction following α-particle exposure of fibroblast lines from nine individuals to determine if there were significant variations. The expression of Cip1 protein indicates the differences in response are biologically relevant

A point mutation of human p53, which was not detected as a mutation by a yeast functional assay, led to apoptosis but not p21Waf1/Cip1/Sdi1 expression in response to ionizing radiation in a human osteosarcoma cell line, Saos-2

International Nuclear Information System (INIS)

Okaichi, Kumio; Wang Lihong; Sasaki, Ji-ichiro; Saya, Hideyuki; Tada, Mitsuhiro; Okumura, Yutaka

1999-01-01

Purpose: The 123A point mutation of p53 showed increased radiosensitivity, whereas other mutations (143A, 175H, and 273H) were not affected. To determine the reason for increased radiosensitivity of the 123A mutation, the response of the transformant of 123A mutation to ionizing radiation (IR) was examined and compared to those of transformants with the wild type p53 or other point mutations (143A, 175H, and 273H). Methods and Materials: Stable transformants with a mutant or wild type p53 made by introducing cDNA into the human osteosarcoma cell line, Saos-2, which lacks an endogenous p53 were used. The transcriptional activity of mutant p53 was examined using a yeast functional assay. The transformants were examined for the accumulation of p53, the induction of p21 Waf1/Cip1/Sdi1 (hereafter referred to as p21), and the other response of p53-responsive genes (MDM2, Bax, and Bcl-2) by Western blotting. Apoptosis was analyzed by detection of DNA fragmentation. Results: The 123A point mutation of p53 was detected as a wild type in the yeast functional assay. The 123A mutant accumulated p53 in response to IR. The 123A mutant did not induce p21, but normally responded to MDM2, Bax, and Bcl-2. The 123A mutant entered apoptosis earlier than the wild type p53 transformant, and induced Fas at earlier in response to IR. Conclusion: The 123A mutant led to apoptosis, but not p21 expression in response to IR. The occurrence of apoptosis, but not induction of p21, corresponded to the radiosensitivity in the transformant. The early occurrence of apoptosis in 123A transformants may depend on the early induction of Fas

Cell-penetrating superoxide dismutase attenuates oxidative stress-induced senescence by regulating the p53-p21Cip1 pathway and restores osteoblastic differentiation in human dental pulp stem cells

Directory of Open Access Journals (Sweden)

Park YJ

2012-09-01

Full Text Available Yoon Jung Choi,1,* Jue Yeon Lee,2,* Chong Pyoung Chung,2 Yoon Jeong Park,1,21Craniomaxillofacial Reconstructive Sciences, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea; 2Research Institute, Nano Intelligent Biomedical Engineering, Seoul, Republic of Korea*These authors contributed equally to this workBackground: Human dental pulp stem cells (DPSCs have potential applications in tissue regeneration because of their convenient cell harvesting procedures and multipotent capacity. However, the tissue regenerative potential of DPSCs is known to be negatively regulated by aging in long-term culture and under oxidative stress. With an aim of reducing cellular senescence and oxidative stress in DPSCs, an intracellular delivery system for superoxide dismutase 1 (SOD1 was developed. We conjugated SOD1 with a cell-penetrating peptide known as low-molecular weight protamine (LMWP, and investigated the effect of LMWP-SOD1 conjugates on hydrogen peroxide-induced cellular senescence and osteoblastic differentiation.Results: LMWP-SOD1 significantly attenuated enlarged and flattened cell morphology and increased senescence-associated β-galactosidase activity. Under the same conditions, LMWP-SOD1 abolished activation of the cell cycle regulator proteins, p53 and p21Cip1, induced by hydrogen peroxide. In addition, LMWP-SOD1 reversed the inhibition of osteoblastic differentiation and downregulation of osteogenic gene markers induced by hydrogen peroxide. However, LMWP-SOD1 could not reverse the decrease in odontogenesis caused by hydrogen peroxide.Conclusion: Overall, cell-penetrating LMWP-SOD1 conjugates are effective for attenuation of cellular senescence and reversal of osteoblastic differentiation of DPSCs caused by oxidative stress inhibition. This result suggests potential application in the field of antiaging and tissue engineering to overcome the limitations of senescent stem cells.Keywords: superoxide

Inactivation of p16INK4a, with retention of pRB and p53/p21cip1 function, in human MRC5 fibroblasts that overcome a telomere-independent crisis during immortalization.

Science.gov (United States)

Taylor, Lisa M; James, Alexander; Schuller, Christine E; Brce, Jesena; Lock, Richard B; Mackenzie, Karen L

2004-10-15

Recent investigations, including our own, have shown that specific strains of fibroblasts expressing telomerase reverse transcriptase (hTERT) have an extended lifespan, but are not immortal. We previously demonstrated that hTERT-transduced MRC5 fetal lung fibroblasts (MRC5hTERTs) bypassed senescence but eventually succumbed to a second mortality barrier (crisis). In the present study, 67 MRC5hTERT clones were established by limiting dilution of a mass culture. Whereas 39/67 clones had an extended lifespan, all 39 extended lifespan clones underwent crisis. 11 of 39 clones escaped crisis and were immortalized. There was no apparent relationship between the fate of clones at crisis and the level of telomerase activity. Telomeres were hyperextended in the majority of the clones analyzed. There was no difference in telomere length of pre-crisis compared with post-crisis and immortal clones, indicating that hyperextended telomeres were conducive for immortalization and confirming that crisis was independent of telomere length. Immortalization of MRC5hTERT cells was associated with repression of the cyclin-dependent kinase inhibitor p16INK4a and up-regulation of pRB. However, the regulation of pRB phosphorylation and the response of the p53/p21cip1/waf1 pathway were normal in immortal cells subject to genotoxic stress. Overexpression of oncogenic ras failed to de-repress p16INK4a in immortal cells. Furthermore, expression of ras enforced senescent-like growth arrest in p16INK4a-positive, but not p16INK4a-negative MRC5hTERT cells. Immortal cells expressing ras formed small, infrequent colonies in soft agarose, but were non-tumorigenic. Overall, these results implicate the inactivation of p16INK4a as a critical event for overcoming telomere-independent crisis, immortalizing MRC5 fibroblasts and overcoming ras-induced premature senescence.

Expression of p21 and p27 in gallbladder cancer

International Nuclear Information System (INIS)

Alsheyab, Fawzi M.; Ziadeh, Moroug T.; Bani-Hani, Kamal E.

2007-01-01

To investigate the expression of p21 and p27 factors in gallbladder cancer (GBC), and to correlate their expression with clinicopathological parameters: age, gender, stage, invasion and grade. Thirty-two surgically resected specimens were collected between 1994-2001 from different health centers in north Jordan. Tissues belong to 25 females and 7 males were examined immunohistochemically. The study took place in the Pathology Department, Jordan University of Science and Technology, Jordan. Levels of p21 were found in 75% and p27 in 25%. Furthermore, p21 was expressed in 50% of the specimens which belong to patients with ages 64 years have p 21WAF1/CIP1 expression (p=0.001). The expression of p21 between advanced stages (stages III and IV) was 89.5% and early stages (stages I and II) was 53.8% (p=0.031). The p27 expression was markedly decreased in GBC cases (25%) and there were no significant correlation between p27KIP1 expression and all clinicopathological parameters including gender, World health Organization grades, stages and invasion, whereas expression of p21 was 75% and there was a significant correlation between p21 and clinicopathological parameters including gender, stages and invasion. (author)

CIP1 polypeptides and their uses

Science.gov (United States)

Foreman, Pamela [Los Altos, CA; Van Solingen, Pieter [Naaldwijk, NL; Goedegebuur, Frits [Vlaardingen, NL; Ward, Michael [San Francisco, CA

2011-04-12

Described herein are novel gene sequences isolated from Trichoderma reesei. Two genes encoding proteins comprising a cellulose binding domain, one encoding an arabionfuranosidase and one encoding an acetylxylanesterase are described. The sequences, CIP1 and CIP2, contain a cellulose binding domain. These proteins are especially useful in the textile and detergent industry and in pulp and paper industry.

Vorinostat enhances protein stability of p27 and p21 through negative regulation of Skp2 and Cks1 in human breast cancer cells.

Science.gov (United States)

Uehara, Norihisa; Yoshizawa, Katsuhiko; Tsubura, Airo

2012-07-01

Vorinostat is a histone deacetylase inhibitor that blocks cancer cell proliferation through the regulation of cyclin-dependent kinase inhibitors. We, herein, examined the involvement of S-phase kinase-associated protein 2 (Skp2) and cyclin-dependent kinase subunit 1 (Cks1), the components of the SCFSkp2-Cks1 (Skp1/Cul1/F-box protein) ubiquitin ligase complex, in the regulation of p27 and p21 during vorinostat-induced growth arrest of MDA-MB-231 and MCF-7 human breast cancer cells. Vorinostat significantly reduced BrdU incorporation in MDA-MB-231 and MCF-7 cells, which was associated with increased p27 and p21 protein levels without concomitant induction of p27 mRNA. Vorinostat-induced accumulation of p27 and p21 proteins was inversely correlated with the mRNA and protein levels of Skp2 and Cks1. Cycloheximide chase analysis revealed that vorinostat increased the half-life of p27 and p21 proteins. The accumulation of p27 and p21 proteins was attenuated by forced expression of Skp2 and Cks1, which conferred resistance to the vorinostat-induced S-phase reduction. These results suggest that vorinostat-induced growth arrest may be in part due to the enhanced protein stability of p27 and p21 through the downregulation of Skp2 and Cks1.

Different domains of P21Cip1/waf1 regulate DNA replication and DNA repair-associated processes after UV

International Nuclear Information System (INIS)

Soria, Gaston; Speroni, Juliana; Podhajcer, Osvaldo L.; Gottifredi, Vanesa; Prives, Carol

2007-01-01

Full text: Many genotoxic insults result in p21 up-regulation and p21-dependent cell cycle arrest but UV irradiation triggers p21 proteolysis. The significance of the increased p21 turnover is unclear and might be associated to DNA repair. While the role of p21 in Nucleotide Excision Repair (NER) remains controversial, two recent reports explore its effect on Translesion DNA Synthesis (TLS), a process that avoids replication blockage during S phase. The first report shows that p21 degradation is required for efficient PCNA ubiquitination, a post transcriptional modification that is relevant for TLS. The second report demonstrates that p21 (-/-) cells have increased TLS-associated mutagenic rates. Herein we analyze the effect of p21 on different PCNA-driven processes including DNA replication, NER and TLS. Whereas only the CDK binding domain of p21 is required for cell cycle arrest in unstressed cells; neither the CDK- nor the PCNA-binding domains of p21 are able to block early and late steps of NER. Intriguingly, through its PCNA binding domain, p21 inhibited recruitment of the TLS-polymerase, polη to PCNA foci after UV. Moreover, this obstruction correlates with accumulation of γH2AX and increased apoptosis. Taking together, our data emphasizes the link between p21 turnover and efficient TLS. This might also suggest a potential effect of p21 on other activities of polζ, a DNA polymerase with central roles in other biological scenarios such as genetic conversion, homologous recombination and modulation of the cellular response to genotoxic agents [es

CASL L1 Milestone report : CASL.P4.01, sensitivity and uncertainty analysis for CIPS with VIPRE-W and BOA.

Energy Technology Data Exchange (ETDEWEB)

Sung, Yixing (Westinghouse Electric Company LLC, Cranberry Township, PA); Adams, Brian M.; Secker, Jeffrey R. (Westinghouse Electric Company LLC, Cranberry Township, PA)

2011-12-01

The CASL Level 1 Milestone CASL.P4.01, successfully completed in December 2011, aimed to 'conduct, using methodologies integrated into VERA, a detailed sensitivity analysis and uncertainty quantification of a crud-relevant problem with baseline VERA capabilities (ANC/VIPRE-W/BOA).' The VUQ focus area led this effort, in partnership with AMA, and with support from VRI. DAKOTA was coupled to existing VIPRE-W thermal-hydraulics and BOA crud/boron deposit simulations representing a pressurized water reactor (PWR) that previously experienced crud-induced power shift (CIPS). This work supports understanding of CIPS by exploring the sensitivity and uncertainty in BOA outputs with respect to uncertain operating and model parameters. This report summarizes work coupling the software tools, characterizing uncertainties, and analyzing the results of iterative sensitivity and uncertainty studies. These studies focused on sensitivity and uncertainty of CIPS indicators calculated by the current version of the BOA code used in the industry. Challenges with this kind of analysis are identified to inform follow-on research goals and VERA development targeting crud-related challenge problems.

CASL L1 Milestone report: CASL.P4.01, sensitivity and uncertainty analysis for CIPS with VIPRE-W and BOA

International Nuclear Information System (INIS)

Sung, Yixing; Adams, Brian M.; Secker, Jeffrey R.

2011-01-01

The CASL Level 1 Milestone CASL.P4.01, successfully completed in December 2011, aimed to 'conduct, using methodologies integrated into VERA, a detailed sensitivity analysis and uncertainty quantification of a crud-relevant problem with baseline VERA capabilities (ANC/VIPRE-W/BOA).' The VUQ focus area led this effort, in partnership with AMA, and with support from VRI. DAKOTA was coupled to existing VIPRE-W thermal-hydraulics and BOA crud/boron deposit simulations representing a pressurized water reactor (PWR) that previously experienced crud-induced power shift (CIPS). This work supports understanding of CIPS by exploring the sensitivity and uncertainty in BOA outputs with respect to uncertain operating and model parameters. This report summarizes work coupling the software tools, characterizing uncertainties, and analyzing the results of iterative sensitivity and uncertainty studies. These studies focused on sensitivity and uncertainty of CIPS indicators calculated by the current version of the BOA code used in the industry. Challenges with this kind of analysis are identified to inform follow-on research goals and VERA development targeting crud-related challenge problems.

The cyclin-dependent kinase inhibitor flavopiridol disrupts sodium butyrate-induced p21WAF1/CIP1 expression and maturation while reciprocally potentiating apoptosis in human leukemia cells.

Science.gov (United States)

Rosato, Roberto R; Almenara, Jorge A; Cartee, Leanne; Betts, Vicki; Chellappan, Srikumar P; Grant, Steven

2002-02-01

Interactions between the cyclin-dependent kinase inhibitor flavopiridol (FP) and the histone deacetylase inhibitor sodium butyrate (SB) have been examined in human leukemia cells (U937) in relation to differentiation and apoptosis. Whereas 1 mM of SB or 100 nM of FP minimally induced apoptosis (4% and 10%, respectively) at 24 h, simultaneous exposure of U937 cells to these agents dramatically increased cell death (e.g., approximately 60%), reflected by both morphological and Annexin/propidium iodide-staining features, procaspase 3 activation, and poly(ADP-ribose) polymerase cleavage. Similar interactions were observed in human promyelocytic (HL-60), B-lymphoblastic (Raji), and T-lymphoblastic (Jurkat) leukemia cells. Coadministration of FP opposed SB-mediated accumulation of cells in G0G1 and differentiation, reflected by reduced CD11b expression, but instead dramatically increased procaspase-3, procaspase-8, Bid, and poly(ADP-ribose) polymerase cleavage, as well as mitochondrial damage (e.g., loss of mitochondrial membrane potential and cytochrome c release). FP also blocked SB-related p21WAF1-CIP1 induction through a caspase-independent mechanism and triggered the caspase-mediated cleavage of p27KIP1 and retinoblastoma protein. The latter event was accompanied by a marked reduction in retinoblastoma protein/E2F1 complex formation. However, FP did not modify the extent of SB-associated acetylation of histones H3 and H4. Treatment of cells with FP/SB also resulted in the caspase-mediated cleavage of Bcl-2 and caspase-independent down-regulation of Mcl-1. Levels of cyclins A, D1, and E, and X-linked inhibitor of apoptosis also declined in SB/FP-treated cells. Finally, FP/SB coexposure potently induced apoptosis in two primary acute myelogenous leukemia samples. Together, these findings demonstrate that FP, when combined with SB, induces multiple perturbations in cell cycle and apoptosis regulatory proteins, which oppose leukemic cell differentiation but instead

SM22α-induced activation of p16INK4a/retinoblastoma pathway promotes cellular senescence caused by a subclinical dose of γ-radiation and doxorubicin in HepG2 cells

International Nuclear Information System (INIS)

Kim, Tae Rim; Lee, Hee Min; Lee, So Yong; Kim, Eun Jin; Kim, Kug Chan; Paik, Sang Gi; Cho, Eun Wie; Kim, In Gyu

2010-01-01

Research highlights: → SM22α overexpression in HepG2 cells leads cells to a growth arrest state, and the treatment of a subclinical dose of γ-radiation or doxorubicin promotes cellular senescence. → SM22α overexpression elevates p16 INK4a followed by pRB activation, but there are no effects on p53/p21 WAF1/Cip1 pathway. → SM22α-induced MT-1G activates p16 INK4a /pRB pathway, which promotes cellular senescence by damaging agents. -- Abstract: Smooth muscle protein 22-alpha (SM22α) is known as a transformation- and shape change-sensitive actin cross-linking protein found in smooth muscle tissue and fibroblasts; however, its functional role remains uncertain. We reported previously that SM22α overexpression confers resistance against anti-cancer drugs or radiation via induction of metallothionein (MT) isozymes in HepG2 cells. In this study, we demonstrate that SM22α overexpression leads cells to a growth arrest state and promotes cellular senescence caused by treatment with a subclinical dose of γ-radiation (0.05 and 0.1 Gy) or doxorubicin (0.01 and 0.05 μg/ml), compared to control cells. Senescence growth arrest is known to be controlled by p53 phosphorylation/p21 WAF1/Cip1 induction or p16 INK4a /retinoblastoma protein (pRB) activation. SM22α overexpression in HepG2 cells elevated p16 INK4a followed by pRB activation, but did not activate the p53/p21 WAF1/Cip1 pathway. Moreover, MT-1G, which is induced by SM22α overexpression, was involved in the activation of the p16 INK4a /pRB pathway, which led to a growth arrest state and promoted cellular senescence caused by damaging agents. Our findings provide the first demonstration that SM22α modulates cellular senescence caused by damaging agents via regulation of the p16 INK4a /pRB pathway in HepG2 cells and that these effects of SM22α are partially mediated by MT-1G.

Multidrug resistance transporters Snq2p and Pdr5p mediate caffeine efflux in Saccharomyces cerevisiae.

Science.gov (United States)

Tsujimoto, Yoshiyuki; Shimizu, Yoshihiro; Otake, Kazuya; Nakamura, Tatsuya; Okada, Ryutaro; Miyazaki, Toshitaka; Watanabe, Kunihiko

2015-01-01

SNQ2 was identified as a caffeine-resistance gene by screening a genomic library of Saccharomyces cerevisiae in a multicopy vector YEp24. SNQ2 encodes an ATP-binding cassette transporter and is highly homologous to PDR5. Multicopy of PDR5 also conferred resistance to caffeine, while its resistance was smaller than that of SNQ2. Residual caffeine contents were analyzed after transiently exposing cells to caffeine. The ratios of caffeine contents were 21.3 ± 8.8% (YEp24-SNQ2) and 81.9 ± 8.7% (YEp24-PDR5) relative to control (YEp24, 100%). In addition, multicopies of SNQ2 or PDR5 conferred resistance to rhodamine 6G (R6G), which was widely used as a substrate for transport assay. R6G was exported by both transporters, and their efflux activities were inhibited by caffeine with half-maximal inhibitory concentrations of 5.3 ± 1.9 (YEp24-SNQ2) and 17.2 ± 9.6 mM (YEp24-PDR5). These results demonstrate that Snq2p is a more functional transporter of caffeine than Pdr5p in yeast cells.

SM22{alpha}-induced activation of p16{sup INK4a}/retinoblastoma pathway promotes cellular senescence caused by a subclinical dose of {gamma}-radiation and doxorubicin in HepG2 cells

Energy Technology Data Exchange (ETDEWEB)

Kim, Tae Rim; Lee, Hee Min; Lee, So Yong; Kim, Eun Jin; Kim, Kug Chan [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Paik, Sang Gi [Department of Biology, School of Biosciences and Biotechnology, Chungnam National University, Daejeon (Korea, Republic of); Cho, Eun Wie, E-mail: ewcho@kribb.re.kr [Daejeon-KRIBB-FHCRC Cooperation Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon (Korea, Republic of); Kim, In Gyu, E-mail: igkim@kaeri.re.kr [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2010-09-10

Research highlights: {yields} SM22{alpha} overexpression in HepG2 cells leads cells to a growth arrest state, and the treatment of a subclinical dose of {gamma}-radiation or doxorubicin promotes cellular senescence. {yields} SM22{alpha} overexpression elevates p16{sup INK4a} followed by pRB activation, but there are no effects on p53/p21{sup WAF1/Cip1} pathway. {yields} SM22{alpha}-induced MT-1G activates p16{sup INK4a}/pRB pathway, which promotes cellular senescence by damaging agents. -- Abstract: Smooth muscle protein 22-alpha (SM22{alpha}) is known as a transformation- and shape change-sensitive actin cross-linking protein found in smooth muscle tissue and fibroblasts; however, its functional role remains uncertain. We reported previously that SM22{alpha} overexpression confers resistance against anti-cancer drugs or radiation via induction of metallothionein (MT) isozymes in HepG2 cells. In this study, we demonstrate that SM22{alpha} overexpression leads cells to a growth arrest state and promotes cellular senescence caused by treatment with a subclinical dose of {gamma}-radiation (0.05 and 0.1 Gy) or doxorubicin (0.01 and 0.05 {mu}g/ml), compared to control cells. Senescence growth arrest is known to be controlled by p53 phosphorylation/p21{sup WAF1/Cip1} induction or p16{sup INK4a}/retinoblastoma protein (pRB) activation. SM22{alpha} overexpression in HepG2 cells elevated p16{sup INK4a} followed by pRB activation, but did not activate the p53/p21{sup WAF1/Cip1} pathway. Moreover, MT-1G, which is induced by SM22{alpha} overexpression, was involved in the activation of the p16{sup INK4a}/pRB pathway, which led to a growth arrest state and promoted cellular senescence caused by damaging agents. Our findings provide the first demonstration that SM22{alpha} modulates cellular senescence caused by damaging agents via regulation of the p16{sup INK4a}/pRB pathway in HepG2 cells and that these effects of SM22{alpha} are partially mediated by MT-1G.

Influences of the disease resistance conferred by the individual ...

African Journals Online (AJOL)

To research possible influences of the disease resistance conferred by different trans-resistance genes on the transgenic rice plants in their yields and grain quality, three transgenic rice lines, including two with the resistance genes Pi-d2 and Pi-d3, respectively, for rice blast, and one with the resistance gene Xa21 for rice ...

Voltage-sensitive sodium channel mutations S989P + V1016G in Aedes aegypti confer variable resistance to pyrethroids, DDT and oxadiazines.

Science.gov (United States)

Smith, Letícia B; Kasai, Shinji; Scott, Jeffrey G

2018-03-01

Aedes aegypti is a vector of several important human pathogens. Control efforts rely primarily on pyrethroid insecticides for adult mosquito control, especially during disease outbreaks. A. aegypti has developed resistance nearly everywhere it occurs and insecticides are used. An important mechanism of resistance is due to mutations in the voltage-sensitive sodium channel (Vssc) gene. Two mutations, in particular, S989P + V1016G, commonly occur together in parts of Asia. We have created a strain (KDR:ROCK) that contains the Vssc mutations S989P + V1016G as the only mechanism of pyrethroid resistance within the genetic background of Rockefeller (ROCK), a susceptible lab strain. We created KDR:ROCK by crossing the pyrethroid-resistant strain Singapore with ROCK followed by four backcrosses with ROCK and Vssc S989P + V1016G genotype selections. We determined the levels of resistance conferred to 17 structurally diverse pyrethroids, the organochloride DDT, and oxadiazines (VSSC blockers) indoxacarb (proinsecticide) and DCJW (the active metabolite of indoxacarb). Levels of resistance to the pyrethroids were variable, ranging from 21- to 107-fold, but no clear pattern between resistance and chemical structure was observed. Resistance is inherited as an incompletely recessive trait. KDR:ROCK had a > 2000-fold resistance to DDT, 37.5-fold cross-resistance to indoxacarb and 13.4-fold cross-resistance to DCJW. Etofenprox (and DDT) should be avoided in areas where Vssc mutations S989P + V1016G exist at high frequencies. We found that pyrethroid structure cannot be used to predict the level of resistance conferred by kdr. These results provide useful information for resistance management and for better understanding pyrethroid interactions with VSSC. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of

Transgenic expression of the rice Xa21 pattern-recognition receptor in banana (Musa sp.) confers resistance to Xanthomonas campestris pv. musacearum.

Science.gov (United States)

Tripathi, Jaindra N; Lorenzen, Jim; Bahar, Ofir; Ronald, Pamela; Tripathi, Leena

2014-08-01

Banana Xanthomonas wilt (BXW), caused by the bacterium Xanthomonas campestris pv. musacearum (Xcm), is the most devastating disease of banana in east and central Africa. The spread of BXW threatens the livelihood of millions of African farmers who depend on banana for food security and income. There are no commercial chemicals, biocontrol agents or resistant cultivars available to control BXW. Here, we take advantage of the robust resistance conferred by the rice pattern-recognition receptor (PRR), XA21, to the rice pathogen Xanthomonas oryzae pv. oryzae (Xoo). We identified a set of genes required for activation of Xa21-mediated immunity (rax) that were conserved in both Xoo and Xcm. Based on the conservation, we hypothesized that intergeneric transfer of Xa21 would confer resistance to Xcm. We evaluated 25 transgenic lines of the banana cultivar 'Gonja manjaya' (AAB) using a rapid bioassay and 12 transgenic lines in the glasshouse for resistance against Xcm. About 50% of the transgenic lines showed complete resistance to Xcm in both assays. In contrast, all of the nontransgenic control plants showed severe symptoms that progressed to complete wilting. These results indicate that the constitutive expression of the rice Xa21 gene in banana results in enhanced resistance against Xcm. Furthermore, this work demonstrates the feasibility of PRR gene transfer between monocotyledonous species and provides a valuable new tool for controlling the BXW pandemic of banana, a staple food for 100 million people in east Africa. © 2014 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Evolution of antibiotic resistance in biofilm and planktonic P. aeruginosa populations exposed to sub-inhibitory levels of ciprofloxacin

DEFF Research Database (Denmark)

Ahmed, Marwa N.; Porse, Andreas; Sommer, Morten Otto Alexander

2018-01-01

in planktonic cultures and are less studied in biofilms. We experimentally evolved P. aeruginosa PAO1 colony-biofilms and stationary-phase planktonic cultures for seven passages in the presence of sub-inhibitory levels (0.1 mg/L) of ciprofloxacin (CIP) and performed a genotypic (whole bacterial population......The opportunistic Gram-negative pathogen Pseudomonas aeruginosa, known for its intrinsic and acquired antibiotic resistance, has a notorious ability to form biofilms, which often facilitate chronic infections. The evolutionary paths to antibiotic resistance have mainly been investigated......-dependent adaptations. A general trend towards a reduction in type IV-pili dependent motility (twitching) in CIP-evolved populations, and towards loss of virulence associated traits in the populations evolved in the absence of antibiotic, was observed. In conclusion, our data indicate that biofilms facilitate...

Both p53-PUMA/NOXA-Bax-mitochondrion and p53-p21cip1 pathways are involved in the CDglyTK-mediated tumor cell suppression

International Nuclear Information System (INIS)

Yu, Zhendong; Wang, Hao; Zhang, Libin; Tang, Aifa; Zhai, Qinna; Wen, Jianxiang; Yao, Li; Li, Pengfei

2009-01-01

CDglyTK fusion suicide gene has been well characterized to effectively kill tumor cells. However, the exact mechanism and downstream target genes are not fully understood. In our study, we found that CDglyTK/prodrug treatment works more efficiently in p53 wild-type (HONE1) cells than in p53 mutant (CNE1) cells. We then used adenovirus-mediated gene delivery system to either knockdown or overexpress p53 and its target genes in these cells. Consistent results showed that both p53-PUMA/NOXA/Bcl2-Bax and p53-p21 pathways contribute to the CDglyTK induced tumor cell suppression. Our work for the first time addressed the role of p53 related genes in the CDglyTK/prodrug system.

Both p53-PUMA/NOXA-Bax-mitochondrion and p53-p21cip1 pathways are involved in the CDglyTK-mediated tumor cell suppression

Energy Technology Data Exchange (ETDEWEB)

Yu, Zhendong, E-mail: zdyu@hotmail.com [Department of Clinical laboratory, Peking University Shenzhen Hospital, Guangdong (China); Wang, Hao [Department of pathology, The Chinese University of Hong Kong, Hong Kong (China); Zhang, Libin; Tang, Aifa; Zhai, Qinna; Wen, Jianxiang; Yao, Li [Department of Clinical laboratory, Peking University Shenzhen Hospital, Guangdong (China); Li, Pengfei, E-mail: lipengfei@cuhk.edu.hk [Department of pathology, The Chinese University of Hong Kong, Hong Kong (China)

2009-09-04

CDglyTK fusion suicide gene has been well characterized to effectively kill tumor cells. However, the exact mechanism and downstream target genes are not fully understood. In our study, we found that CDglyTK/prodrug treatment works more efficiently in p53 wild-type (HONE1) cells than in p53 mutant (CNE1) cells. We then used adenovirus-mediated gene delivery system to either knockdown or overexpress p53 and its target genes in these cells. Consistent results showed that both p53-PUMA/NOXA/Bcl2-Bax and p53-p21 pathways contribute to the CDglyTK induced tumor cell suppression. Our work for the first time addressed the role of p53 related genes in the CDglyTK/prodrug system.

The Cytochrome P450 gene CYP6P12 confers pyrethroid resistance in kdr-free Malaysian populations of the dengue vector Aedes albopictus.

Science.gov (United States)

Ishak, Intan H; Riveron, Jacob M; Ibrahim, Sulaiman S; Stott, Rob; Longbottom, Joshua; Irving, Helen; Wondji, Charles S

2016-04-20

Control of Aedes albopictus, major dengue and chikungunya vector, is threatened by growing cases of insecticide resistance. The mechanisms driving this resistance remain poorly characterised. This study investigated the molecular basis of insecticide resistance in Malaysian populations of Ae. albopictus. Microarray-based transcription profiling revealed that metabolic resistance (cytochrome P450 up-regulation) and possibly a reduced penetration mechanism (consistent over-expression of cuticular protein genes) were associated with pyrethroid resistance. CYP6P12 over-expression was strongly associated with pyrethroid resistance whereas CYP6N3 was rather consistently over-expressed across carbamate and DDT resistant populations. Other detoxification genes also up-regulated in permethrin resistant mosquitoes included a glucuronosyltransferase (AAEL014279-RA) and the glutathione-S transferases GSTS1 and GSTT3. Functional analyses further supported that CYP6P12 contributes to pyrethroid resistance in Ae. albopictus as transgenic expression of CYP6P12 in Drosophila was sufficient to confer pyrethroid resistance in these flies. Furthermore, molecular docking simulations predicted CYP6P12 possessing enzymatic activity towards pyrethroids. Patterns of polymorphism suggested early sign of selection acting on CYP6P12 but not on CYP6N3. The major role played by P450 in the absence of kdr mutations suggests that addition of the synergist PBO to pyrethroids could improve the efficacy of this insecticide class and overcome resistance in field populations of Ae. albopictus.

Familial partial duplication (1)(p21p31)

Energy Technology Data Exchange (ETDEWEB)

Hoechstetter, L.; Soukup, S.; Schorry, E.K. [Children`s Hospital Research Foundation, Cincinnati, OH (United States)

1995-11-20

A partial duplication (1)(p21p31), resulting from a maternal direct insertion (13,1) (q22p21p31), was found in a 30-year-old woman with mental retardation, cleft palate, and multiple minor anomalies. Two other affected and deceased relatives were presumed to have the same chromosome imbalance. Duplication 1p cases are reviewed. 8 refs., 5 figs., 1 tab.

Overexpression of Rice Auxilin-Like Protein, XB21, Induces Necrotic Lesions, up-Regulates Endocytosis-Related Genes, and Confers Enhanced Resistance to Xanthomonas oryzae pv. oryzae.

Science.gov (United States)

Park, Chang-Jin; Wei, Tong; Sharma, Rita; Ronald, Pamela C

2017-12-01

The rice immune receptor XA21 confers resistance to the bacterial pathogen, Xanthomonas oryzae pv. oryzae (Xoo). To elucidate the mechanism of XA21-mediated immunity, we previously performed a yeast two-hybrid screening for XA21 interactors and identified XA21 binding protein 21 (XB21). Here, we report that XB21 is an auxilin-like protein predicted to function in clathrin-mediated endocytosis. We demonstrate an XA21/XB21 in vivo interaction using co-immunoprecipitation in rice. Overexpression of XB21 in rice variety Kitaake and a Kitaake transgenic line expressing XA21 confers a necrotic lesion phenotype and enhances resistance to Xoo. RNA sequencing reveals that XB21 overexpression results in the differential expression of 8735 genes (4939 genes up- and 3846 genes down-regulated) (≥2-folds, FDR ≤0.01). The up-regulated genes include those predicted to be involved in 'cell death' and 'vesicle-mediated transport'. These results indicate that XB21 plays a role in the plant immune response and in regulation of cell death. The up-regulation of genes controlling 'vesicle-mediated transport' in XB21 overexpression lines is consistent with a functional role for XB21 as an auxilin.

Anti-cancer effect of novel PAK1 inhibitor via induction of PUMA-mediated cell death and p21-mediated cell cycle arrest.

Science.gov (United States)

Woo, Tae-Gyun; Yoon, Min-Ho; Hong, Shin-Deok; Choi, Jiyun; Ha, Nam-Chul; Sun, Hokeun; Park, Bum-Joon

2017-04-04

Hyper-activation of PAK1 (p21-activated kinase 1) is frequently observed in human cancer and speculated as a target of novel anti-tumor drug. In previous, we also showed that PAK1 is highly activated in the Smad4-deficient condition and suppresses PUMA (p53 upregulated modulator of apoptosis) through direct binding and phosphorylation. On the basis of this result, we have tried to find novel PAK1-PUMA binding inhibitors. Through ELISA-based blind chemical library screening, we isolated single compound, IPP-14 (IPP; Inhibitor of PAK1-PUMA), which selectively blocks the PAK1-PUMA binding and also suppresses cell proliferation via PUMA-dependent manner. Indeed, in PUMA-deficient cells, this chemical did not show anti-proliferating effect. This chemical possessed very strong PAK1 inhibition activity that it suppressed BAD (Bcl-2-asoociated death promoter) phosphorylation and meta-phase arrest via Aurora kinase inactivation in lower concentration than that of previous PAK1 kinase, FRAX486 and AG879. Moreover, our chemical obviously induced p21/WAF1/CIP1 (Cyclin-dependent kinase inhibitor 1A) expression by releasing from Bcl-2 (B-cell lymphoma-2) and by inhibition of AKT-mediated p21 suppression. Considering our result, IPP-14 and its derivatives would be possible candidates for PAK1 and p21 induction targeted anti-cancer drug.

Apolipoprotein L1 confers pH-switchable ion permeability to phospholipid vesicles.

Science.gov (United States)

Bruno, Jonathan; Pozzi, Nicola; Oliva, Jonathan; Edwards, John C

2017-11-03

Apolipoprotein L1 (ApoL1) is a human serum protein conferring resistance to African trypanosomes, and certain ApoL1 variants increase susceptibility to some progressive kidney diseases. ApoL1 has been hypothesized to function like a pore-forming colicin and has been reported to have permeability effects on both intracellular and plasma membranes. Here, to gain insight into how ApoL1 may function in vivo , we used vesicle-based ion permeability, direct membrane association, and intrinsic fluorescence to study the activities of purified recombinant ApoL1. We found that ApoL1 confers chloride-selective permeability to preformed phospholipid vesicles and that this selectivity is strongly pH-sensitive, with maximal activity at pH 5 and little activity above pH 7. When ApoL1 and lipid were allowed to interact at low pH and were then brought to neutral pH, chloride permeability was suppressed, and potassium permeability was activated. Both chloride and potassium permeability linearly correlated with the mass of ApoL1 in the reaction mixture, and both exhibited lipid selectivity, requiring the presence of negatively charged lipids for activity. Potassium, but not chloride, permease activity required the presence of calcium ions in both the association and activation steps. Direct assessment of ApoL1-lipid associations confirmed that ApoL1 stably associates with phospholipid vesicles, requiring low pH and the presence of negatively charged phospholipids for maximal binding. Intrinsic fluorescence of ApoL1 supported the presence of a significant structural transition when ApoL1 is mixed with lipids at low pH. This pH-switchable ion-selective permeability may explain the different effects of ApoL1 reported in intracellular and plasma membrane environments. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Antifolate resistance mediated by the multidrug resistance proteins MRP1 and MRP2

NARCIS (Netherlands)

Hooijberg, J. H.; Broxterman, H. J.; Kool, M.; Assaraf, Y. G.; Peters, G. J.; Noordhuis, P.; Scheper, R. J.; Borst, P.; Pinedo, H. M.; Jansen, G.

1999-01-01

Transfection of multidrug resistance proteins (MRPs) MRP1 and MRP2 in human ovarian carcinoma 2008 cells conferred a marked level of resistance to short-term (1-4 h) exposure to the polyglutamatable antifolates methotrexate (MTX; 21-74-fold), ZD1694 (4-138-fold), and GW1843 (101-156-fold). Evidence

Internal Tandem Duplication in FLT3 Attenuates Proliferation and Regulates Resistance to the FLT3 Inhibitor AC220 by Modulating p21Cdkn1a and Pbx1 in Hematopoietic Cells.

Directory of Open Access Journals (Sweden)

Mariko Abe

Full Text Available Internal tandem duplication (ITD mutations in the Fms-related tyrosine kinase 3 (FLT3 gene (FLT3-ITD are associated with poor prognosis in patients with acute myeloid leukemia (AML. Due to the development of drug resistance, few FLT3-ITD inhibitors are effective against FLT3-ITD+ AML. In this study, we show that FLT3-ITD activates a novel pathway involving p21Cdkn1a (p21 and pre-B cell leukemia transcription factor 1 (Pbx1 that attenuates FLT3-ITD cell proliferation and is involved in the development of drug resistance. FLT3-ITD up-regulated p21 expression in both mouse bone marrow c-kit+-Sca-1+-Lin- (KSL cells and Ba/F3 cells. The loss of p21 expression enhanced growth factor-independent proliferation and sensitivity to cytarabine as a consequence of concomitantly enriching the S+G2/M phase population and significantly increasing the expression of Pbx1, but not Evi-1, in FLT3-ITD+ cells. This enhanced cell proliferation following the loss of p21 was partially abrogated when Pbx1 expression was silenced in FLT3-ITD+ primary bone marrow colony-forming cells and Ba/F3 cells. When FLT3-ITD was antagonized with AC220, a selective inhibitor of FLT3-ITD, p21 expression was decreased coincident with Pbx1 mRNA up-regulation and a rapid decline in the number of viable FLT3-ITD+ Ba/F3 cells; however, the cells eventually became refractory to AC220. Overexpressing p21 in FLT3-ITD+ Ba/F3 cells delayed the emergence of cells that were refractory to AC220, whereas p21 silencing accelerated their development. These data indicate that FLT3-ITD is capable of inhibiting FLT3-ITD+ cell proliferation through the p21/Pbx1 axis and that treatments that antagonize FLT3-ITD contribute to the subsequent development of cells that are refractory to a FLT3-ITD inhibitor by disrupting p21 expression.

Major QTL Conferring Resistance to Rice Bacterial Leaf Streak

Institute of Scientific and Technical Information of China (English)

无

2006-01-01

Bacterial leaf streak (BLS) is one of the important limiting factors to rice production in southern China and other tropical and sub-tropical areas in Asia. Resistance to BLS was found to be a quantitative trait and no major resistant gene was located in rice until date. In the present study, a new major quantitative trait locus (QTL) conferring resistance to BLS was identified from a highly resistant variety Dular by the employment of Dular/Balilla (DB) and Dular/IR24 (DI) segregation populations and was designated qBLSR-11-1. This QTL was located between the simple sequence repeat (SSR) markers RM120 and RM441 on chromosome 11 and could account for 18.1-21.7% and 36.3% of the variance in DB and DI populations, respectively. The genetic pattern of rice resistance to BLS was discussed.

MicroRNA-21 induces 5-fluorouracil resistance in human pancreatic cancer cells by regulating PTEN and PDCD4

International Nuclear Information System (INIS)

Wei, Xueju; Wang, Weibin; Wang, Lanlan; Zhang, Yuanyuan; Zhang, Xian; Chen, Mingtai; Wang, Fang; Yu, Jia; Ma, Yanni; Sun, Guotao

2016-01-01

Pancreatic cancer patients are often resistant to chemotherapy treatment, which results in poor prognosis. The objective of this study was to delineate the mechanism by which miR-21 induces drug resistance to 5-fluorouracil (5-FU) in human pancreatic cancer cells (PATU8988 and PANC-1). We report that PATU8988 cells resistant to 5-FU express high levels of miR-21 in comparison to sensitive primary PATU8988 cells. Suppression of miR-21 expression in 5-Fu-resistant PATU8988 cells can alleviate its 5-FU resistance. Meanwhile, lentiviral vector-mediated overexpression of miR-21 not only conferred resistance to 5-FU but also promoted proliferation, migration, and invasion of PATU8988 and PANC-1 cells. The proresistance effects of miR-21 were attributed to the attenuated expression of tumor suppressor genes, including PTEN and PDCD4. Overexpression of PTEN and PDCD4 antagonized miR-21-induced resistance to 5-FU and migration activity. Our work demonstrates that miR-21 can confer drug resistance to 5-FU in pancreatic cancer cells by regulating the expression of tumor suppressor genes, as the target genes of miR-21, PTEN and PDCD4 can rescue 5-FU sensitivity and the phenotypic characteristics disrupted by miR-21

Increased p50/p50 NF-κB Activation in Human Papillomavirus Type 6- or Type 11-Induced Laryngeal Papilloma Tissue

Science.gov (United States)

Vancurova, Ivana; Wu, Rong; Miskolci, Veronika; Sun, Shishinn

2002-01-01

We have observed elevated NF-κB DNA-binding activity in nuclear extracts from human papillomavirus type 6- and 11-infected laryngeal papilloma tissues. The predominant DNA-binding species is the p50/p50 homodimer. The elevated NF-κB activity could be correlated with a reduced level of cytoplasmic IκBβ and could be associated with the overexpression of p21CIP1/WAF1 in papilloma cells. Increased NF-κB activity and cytoplasmic accumulation of p21CIP1/WAF1 might counteract death-promoting effects elicited by overexpressed PTEN and reduced activation of Akt and STAT3 previously noted in these tissues. PMID:11773428

Quantitative genome re-sequencing defines multiple mutations conferring chloroquine resistance in rodent malaria

Science.gov (United States)

2012-01-01

Background Drug resistance in the malaria parasite Plasmodium falciparum severely compromises the treatment and control of malaria. A knowledge of the critical mutations conferring resistance to particular drugs is important in understanding modes of drug action and mechanisms of resistances. They are required to design better therapies and limit drug resistance. A mutation in the gene (pfcrt) encoding a membrane transporter has been identified as a principal determinant of chloroquine resistance in P. falciparum, but we lack a full account of higher level chloroquine resistance. Furthermore, the determinants of resistance in the other major human malaria parasite, P. vivax, are not known. To address these questions, we investigated the genetic basis of chloroquine resistance in an isogenic lineage of rodent malaria parasite P. chabaudi in which high level resistance to chloroquine has been progressively selected under laboratory conditions. Results Loci containing the critical genes were mapped by Linkage Group Selection, using a genetic cross between the high-level chloroquine-resistant mutant and a genetically distinct sensitive strain. A novel high-resolution quantitative whole-genome re-sequencing approach was used to reveal three regions of selection on chr11, chr03 and chr02 that appear progressively at increasing drug doses on three chromosomes. Whole-genome sequencing of the chloroquine-resistant parent identified just four point mutations in different genes on these chromosomes. Three mutations are located at the foci of the selection valleys and are therefore predicted to confer different levels of chloroquine resistance. The critical mutation conferring the first level of chloroquine resistance is found in aat1, a putative aminoacid transporter. Conclusions Quantitative trait loci conferring selectable phenotypes, such as drug resistance, can be mapped directly using progressive genome-wide linkage group selection. Quantitative genome-wide short

Heterologous expression of the yeast Tpo1p or Pdr5p membrane transporters in Arabidopsis confers plant xenobiotic tolerance.

Science.gov (United States)

Remy, Estelle; Niño-González, María; Godinho, Cláudia P; Cabrito, Tânia R; Teixeira, Miguel C; Sá-Correia, Isabel; Duque, Paula

2017-07-03

Soil contamination is a major hindrance for plant growth and development. The lack of effective strategies to remove chemicals released into the environment has raised the need to increase plant resilience to soil pollutants. Here, we investigated the ability of two Saccharomyces cerevisiae plasma-membrane transporters, the Major Facilitator Superfamily (MFS) member Tpo1p and the ATP-Binding Cassette (ABC) protein Pdr5p, to confer Multiple Drug Resistance (MDR) in Arabidopsis thaliana. Transgenic plants expressing either of the yeast transporters were undistinguishable from the wild type under control conditions, but displayed tolerance when challenged with the herbicides 2,4-D and barban. Plants expressing ScTPO1 were also more resistant to the herbicides alachlor and metolachlor as well as to the fungicide mancozeb and the Co 2+ , Cu 2+ , Ni 2+ , Al 3+ and Cd 2+ cations, while ScPDR5-expressing plants exhibited tolerance to cycloheximide. Yeast mutants lacking Tpo1p or Pdr5p showed increased sensitivity to most of the agents tested in plants. Our results demonstrate that the S. cerevisiae Tpo1p and Pdr5p transporters are able to mediate resistance to a broad range of compounds of agricultural interest in yeast as well as in Arabidopsis, underscoring their potential in future biotechnological applications.

CIP2A protein expression in high-grade, high-stage bladder cancer

International Nuclear Information System (INIS)

Huang, Lisa P; Savoly, Diana; Sidi, Abraham A; Adelson, Martin E; Mordechai, Eli; Trama, Jason P

2012-01-01

Bladder cancer is one of the most common cancers in the United States. Numerous markers have been evaluated for suitability of bladder cancer detection and surveillance. However, few of them are acceptable as a routine tool. Therefore, there exists a continuing need for an assay that detects the presence of bladder cancer in humans. It would be advantageous to develop an assay with a protein that is associated with the development of bladder cancer. We have identified the cancerous inhibitor of PP2A (CIP2A) protein as a novel bladder cancer biomarker. In this study, Western blot analysis was used to assess the expression level of CIP2A protein in bladder cancer cell lines and bladder cancer patient tissues (n = 43). Our studies indicated CIP2A protein was abundantly expressed in bladder cancer cell lines but not in nontumor epithelial cell lines. Furthermore, CIP2A was specifically expressed in transitional cell carcinoma (TCC) of the bladder tumor tissues but not in adjacent nontumor bladder tissue. Our data showed that CIP2A protein detection in high-grade TCC tissues had a sensitivity of 65%, which is 3.4-fold higher than that seen in low-grade TCC tissues (19%). The level of CIP2A protein expression increased with the stage of disease (12%, 27%, 67%, and 100% for pTa, pT1, pT2, and pT3 tumor, respectively). In conclusion, our studies suggest that CIP2A protein is specifically expressed in human bladder tumors. CIP2A is preferentially expressed in high-grade and high-stage TCC tumors, which are high-risk and invasive tumors. Our studies reported here support the role of CIP2A in bladder cancer progression and its usefulness for the surveillance of recurrence or progression of human bladder cancer

Functional ablation of pRb activates Cdk2 and causes antiestrogen resistance in human breast cancer cells.

Directory of Open Access Journals (Sweden)

Hemant Varma

2007-12-01

Full Text Available Estrogens are required for the proliferation of hormone dependent breast cancer cells, making estrogen receptor (ER positive tumors amenable to endocrine therapies such as antiestrogens. However, resistance to these agents remains a significant cause of treatment failure. We previously demonstrated that inactivation of the retinoblastoma protein (pRb family tumor suppressors causes antiestrogen resistance in MCF-7 cells, a widely studied model of estrogen responsive human breast cancers. In this study, we investigate the mechanism by which pRb inactivation leads to antiestrogen resistance. Cdk4 and cdk2 are two key cell cycle regulators that can phosphorylate and inactivate pRb, therefore we tested whether these kinases are required in cells lacking pRb function. pRb family members were inactivated in MCF-7 cells by expressing polyomavirus large tumor antigen (PyLT, and cdk activity was inhibited using the cdk inhibitors p16(INK4A and p21(Waf1/Cip1. Cdk4 activity was no longer required in cells lacking functional pRb, while cdk2 activity was required for proliferation in both the presence and absence of pRb function. Using inducible PyLT cell lines, we further demonstrated that pRb inactivation leads to increased cyclin A expression, cdk2 activation and proliferation in antiestrogen arrested cells. These results demonstrate that antiestrogens do not inhibit cdk2 activity or proliferation of MCF-7 cells in the absence of pRb family function, and suggest that antiestrogen resistant breast cancer cells resulting from pRb pathway inactivation would be susceptible to therapies that target cdk2.

The crystal structure of the core domain of a cellulose induced protein (Cip1 from Hypocrea jecorina, at 1.5 Å resolution.

Directory of Open Access Journals (Sweden)

Frida Jacobson

Full Text Available In an effort to characterise the whole transcriptome of the fungus Hypocrea jecorina, cDNA clones of this fungus were identified that encode for previously unknown proteins that are likely to function in biomass degradation. One of these newly identified proteins, found to be co-regulated with the major H. jecorina cellulases, is a protein that was denoted Cellulose induced protein 1 (Cip1. This protein consists of a glycoside hydrolase family 1 carbohydrate binding module connected via a linker region to a domain with yet unknown function. After cloning and expression of Cip1 in H. jecorina, the protein was purified and biochemically characterised with the aim of determining a potential enzymatic activity for the novel protein. No hydrolytic activity against any of the tested plant cell wall components was found. The proteolytic core domain of Cip1 was then crystallised, and the three-dimensional structure of this was determined to 1.5 Å resolution utilising sulphur single-wavelength anomalous dispersion phasing (sulphor-SAD. A calcium ion binding site was identified in a sequence conserved region of Cip1 and is also seen in other proteins with the same general fold as Cip1, such as many carbohydrate binding modules. The presence of this ion was found to have a structural role. The Cip1 structure was analysed and a structural homology search was performed to identify structurally related proteins. The two published structures with highest overall structural similarity to Cip1 found were two poly-lyases: CsGL, a glucuronan lyase from H. jecorina and vAL-1, an alginate lyase from the Chlorella virus. This indicates that Cip1 may be a lyase. However, initial trials did not detect significant lyase activity for Cip1. Cip1 is the first structure to be solved of the 23 currently known Cip1 sequential homologs (with a sequence identity cut-off of 25%, including both bacterial and fungal members.

Silencing of the Rice Gene LRR1 Compromises Rice Xa21 Transcript Accumulation and XA21-Mediated Immunity.

Science.gov (United States)

Caddell, Daniel F; Park, Chang-Jin; Thomas, Nicholas C; Canlas, Patrick E; Ronald, Pamela C

2017-12-01

The rice immune receptor XA21 confers resistance to Xanthomonas oryzae pv. oryzae (Xoo), the causal agent of bacterial leaf blight. We previously demonstrated that an auxilin-like protein, XA21 BINDING PROTEIN 21 (XB21), positively regulates resistance to Xoo. To further investigate the function of XB21, we performed a yeast two-hybrid screen. We identified 22 unique XB21 interacting proteins, including LEUCINE-RICH REPEAT PROTEIN 1 (LRR1), which we selected for further analysis. Silencing of LRR1 in the XA21 genetic background (XA21-LRR1Ri) compromises resistance to Xoo compared with control XA21 plants. XA21-LRR1Ri plants have reduced Xa21 transcript levels and reduced expression of genes that serve as markers of XA21-mediated activation. Overexpression of LRR1 is insufficient to alter resistance to Xoo in rice lines lacking XA21. Taken together, our results indicate that LRR1 is required for wild-type Xa21 transcript expression and XA21-mediated immunity.

CipA of Acinetobacter baumannii Is a Novel Plasminogen Binding and Complement Inhibitory Protein.

Science.gov (United States)

Koenigs, Arno; Stahl, Julia; Averhoff, Beate; Göttig, Stephan; Wichelhaus, Thomas A; Wallich, Reinhard; Zipfel, Peter F; Kraiczy, Peter

2016-05-01

Acinetobacter baumannii is an emerging opportunistic pathogen, responsible for up to 10% of gram-negative, nosocomial infections. The global increase of multidrug-resistant and pan-resistant Acinetobacter isolates presents clinicians with formidable challenges. To establish a persistent infection,A. baumannii must overcome the detrimental effects of complement as the first line of defense against invading microorganisms. However, the immune evasion principles underlying serum resistance inA. baumannii remain elusive. Here, we identified a novel plasminogen-binding protein, termed CipA. Bound plasminogen, upon conversion to active plasmin, degraded fibrinogen and complement C3b and contributed to serum resistance. Furthermore, CipA directly inhibited the alternative pathway of complement in vitro, irrespective of its ability to bind plasminogen. A CipA-deficient mutant was efficiently killed by human serum and showed a defect in the penetration of endothelial monolayers, demonstrating that CipA is a novel multifunctional protein that contributes to the pathogenesis ofA. baumannii. © The Author 2015. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

KLF10, transforming growth factor-{beta}-inducible early gene 1, acts as a tumor suppressor

Energy Technology Data Exchange (ETDEWEB)

Song, Ki-Duk [Center for Agricultural Biomaterials, Seoul National University, Seoul 151-921 (Korea, Republic of); Laboratory of Protein Engineering and Comparative Immunology, School of Agricultural Biotechnology, Seoul National University, Seoul 151-921 (Korea, Republic of); Kim, Duk-Jung [The Institute of Hankook Life Science, 7-9 Myungryun-dong, Jongno-gu, Seoul 110-521 (Korea, Republic of); Lee, Jong Eun [Department of Anatomy, College of Medicine, Yonsei University, Seoul 120-752 (Korea, Republic of); Yun, Cheol-Heui [Center for Agricultural Biomaterials, Seoul National University, Seoul 151-921 (Korea, Republic of); Laboratory of Protein Engineering and Comparative Immunology, School of Agricultural Biotechnology, Seoul National University, Seoul 151-921 (Korea, Republic of); Lee, Woon Kyu, E-mail: wklee@inha.ac.kr [Laboratory of Developmental Genetics, School of Medicine, Inha University, Incheon 400-712 (Korea, Republic of); Brain Korea 21 Center for Advanced Medical Education, School of Medicine, Inha University, Incheon 400-712 (Korea, Republic of)

2012-03-09

Highlights: Black-Right-Pointing-Pointer KLF10{sup -/-} mice exhibited accelerated papilloma development after DMBA/TPA treatment. Black-Right-Pointing-Pointer KLF10{sup -/-} keratinocytes showed increased proliferation and apoptosis. Black-Right-Pointing-Pointer KLF10{sup -/-} MEFs yielded more colonies than wild-type one with H-Ras transfection. Black-Right-Pointing-Pointer KLF10 dose-dependently activated p21{sup WAF1/CIP1} transcription. Black-Right-Pointing-Pointer KLF10 is a tumor suppressor and that it targets p21{sup WAF1/CIP1} transcription. -- Abstract: Krueppel-like factor 10 (KLF10) has been suggested to be a putative tumor suppressor. In the present study, we generated KLF10 deficient mice to explore this hypothesis in vivo. KLF10 deficient mice exhibited increased predisposition to skin tumorigenesis and markedly accelerated papilloma development after DMBA/TPA treatment. On the other hand, KLF10 deficient keratinocytes showed increased proliferation and apoptosis. In colony formation assays after oncogenic H-Ras transfection, KLF10 deficient mouse embryonic fibroblasts (MEFs) yielded more colonies than wild-type MEFs. Furthermore, KLF10 dose-dependently activated p21{sup WAF1/CIP1} transcription, which was independent of p53 and Sp1 binding sites in p21{sup WAF1/CIP1} promoter. This study demonstrates that KLF10 is a tumor suppressor and that it targets p21{sup WAF1/CIP1} transcription.

ETS1 mediates MEK1/2-dependent overexpression of cancerous inhibitor of protein phosphatase 2A (CIP2A in human cancer cells.

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Anchit Khanna

2011-03-01

Full Text Available EGFR-MEK-ERK signaling pathway has an established role in promoting malignant growth and disease progression in human cancers. Therefore identification of transcriptional targets mediating the oncogenic effects of the EGFR-MEK-ERK pathway would be highly relevant. Cancerous inhibitor of protein phosphatase 2A (CIP2A is a recently characterized human oncoprotein. CIP2A promotes malignant cell growth and is over expressed at high frequency (40-80% in most of the human cancer types. However, the mechanisms inducing its expression in cancer still remain largely unexplored. Here we present systematic analysis of contribution of potential gene regulatory mechanisms for high CIP2A expression in cancer. Our data shows that evolutionary conserved CpG islands at the proximal CIP2A promoter are not methylated both in normal and cancer cells. Furthermore, sequencing of the active CIP2A promoter region from altogether seven normal and malignant cell types did not reveal any sequence alterations that would increase CIP2A expression specifically in cancer cells. However, treatment of cancer cells with various signaling pathway inhibitors revealed that CIP2A mRNA expression was sensitive to inhibition of EGFR activity as well as inhibition or activation of MEK-ERK pathway. Moreover, MEK1/2-specific siRNAs decreased CIP2A protein expression. Series of CIP2A promoter-luciferase constructs were created to identify proximal -27 to -107 promoter region responsible for MEK-dependent stimulation of CIP2A expression. Additional mutagenesis and chromatin immunoprecipitation experiments revealed ETS1 as the transcription factor mediating stimulation of CIP2A expression through EGFR-MEK pathway. Thus, ETS1 is probably mediating high CIP2A expression in human cancers with increased EGFR-MEK1/2-ERK pathway activity. These results also suggest that in addition to its established role in invasion and angiogenesis, ETS1 may support malignant cellular growth via regulation of

A synthetic peptide derived from alpha-fetoprotein inhibits the estradiol-induced proliferation of mammary tumor cells in culture through the modulation of p21.

Science.gov (United States)

Sierralta, Walter D; Epuñan, María J; Reyes, José M; Valladares, Luis E; Pino, Ana M

2008-01-01

A stable cyclized 9-mer peptide (cP) containing the active site of alpha-alpha fetoprotein (alphaFP) has been shown to be effective for prevention of estrogen-stimulated tumor cell proliferation in culture or of xenographt growth in immunodeficient mice. cP does not block 17beta-estradiol (E2) binding to its receptors, but rather appears to interfere with intracellular processing of the signal that supports growth. To obtain insight on that mechanism we studied the effect of cP on the proliferation of MCF-7 cells in culture. Proliferation in the presence of 2 microM E2 is decreased up to 40% upon addition of 2 microg ml(-1) cP to the medium; the presence of cP did not increase cell death, cP reduced also the proliferation of estrogen-dependent ZR75-1 cells but had no effect on autonomous MDA-MB-231 cells, cP did not modify the number of binding sites for labeled E2 or affected cell death. We detected increased nuclear p21Cip1 immunoreactivity after cP treatment. Our results suggest that cP acts via p21Cip1 to slow the process of MCF-7 cells through the cycle.

Caffeic acid phenethyl ester induced cell cycle arrest and growth inhibition in androgen-independent prostate cancer cells via regulation of Skp2, p53, p21Cip1 and p27Kip1

OpenAIRE

Lin, Hui-Ping; Lin, Ching-Yu; Huo, Chieh; Hsiao, Ping-Hsuan; Su, Liang-Cheng; Jiang, Shih Sheng; Chan, Tzu-Min; Chang, Chung-Ho; Chen, Li-Tzong; Kung, Hsing-Jien; Wang, Horng-Dar; Chuu, Chih-Pin

2015-01-01

Prostate cancer (PCa) patients receiving the androgen ablation therapy ultimately develop recurrent castration-resistant prostate cancer (CRPC) within 1?3 years. Treatment with caffeic acid phenethyl ester (CAPE) suppressed cell survival and proliferation via induction of G1 or G2/M cell cycle arrest in LNCaP 104-R1, DU-145, 22Rv1, and C4?2 CRPC cells. CAPE treatment also inhibited soft agar colony formation and retarded nude mice xenograft growth of LNCaP 104-R1 cells. We identified that CAP...

Novel deletion alleles carrying CYP21A1P/A2 chimeric genes in Brazilian patients with 21-hydroxylase deficiency

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Guerra-Júnior Gil

2010-06-01

Full Text Available Abstract Background Congenital adrenal hyperplasia due to 21-hydroxylase deficiency is caused by deletions, large gene conversions or mutations in CYP21A2 gene. The human gene is located at 6p21.3 within a locus containing the genes for putative serine/threonine Kinase RP, complement C4, steroid 21-hydroxylase CYP21 tenascin TNX, normally, in a duplicated cluster known as RCCX module. The CYP21 extra copy is a pseudogene (CYP21A1P. In Brazil, 30-kb deletion forming monomodular alleles that carry chimeric CYP21A1P/A2 genes corresponds to ~9% of disease-causing alleles. Such alleles are considered to result from unequal crossovers within the bimodular C4/CYP21 locus. Depending on the localization of recombination breakpoint, different alleles can be generated conferring the locus high degree of allelic variability. The purpose of the study was to investigate the variability of deleted alleles in patients with 21-hydroxylase deficiency. Methods We used different techniques to investigate the variability of 30-kb deletion alleles in patients with 21-hydroxylase deficiency. Alleles were first selected after Southern blotting. The composition of CYP21A1P/A2 chimeric genes was investigated by ASO-PCR and MLPA analyses followed by sequencing to refine the location of recombination breakpoints. Twenty patients carrying at least one allele with C4/CYP21 30-kb deletion were included in the study. Results An allele carrying a CYP21A1P/A2 chimeric gene was found unusually associated to a C4B/C4A Taq I 6.4-kb fragment, generally associated to C4B and CYP21A1P deletions. A novel haplotype bearing both p.P34L and p.H62L, novel and rare mutations, respectively, was identified in exon 1, however p.P30L, the most frequent pseudogene-derived mutation in this exon, was absent. Four unrelated patients showed this haplotype. Absence of p.P34L in CYP21A1P of normal controls indicated that it is not derived from pseudogene. In addition, the combination of different

CIPS Validation Data Plan

International Nuclear Information System (INIS)

Dinh, Nam

2012-01-01

This report documents analysis, findings and recommendations resulted from a task 'CIPS Validation Data Plan (VDP)' formulated as an POR4 activity in the CASL VUQ Focus Area (FA), to develop a Validation Data Plan (VDP) for Crud-Induced Power Shift (CIPS) challenge problem, and provide guidance for the CIPS VDP implementation. The main reason and motivation for this task to be carried at this time in the VUQ FA is to bring together (i) knowledge of modern view and capability in VUQ, (ii) knowledge of physical processes that govern the CIPS, and (iii) knowledge of codes, models, and data available, used, potentially accessible, and/or being developed in CASL for CIPS prediction, to devise a practical VDP that effectively supports the CASL's mission in CIPS applications.

CIPS Validation Data Plan

Energy Technology Data Exchange (ETDEWEB)

Nam Dinh

2012-03-01

This report documents analysis, findings and recommendations resulted from a task 'CIPS Validation Data Plan (VDP)' formulated as an POR4 activity in the CASL VUQ Focus Area (FA), to develop a Validation Data Plan (VDP) for Crud-Induced Power Shift (CIPS) challenge problem, and provide guidance for the CIPS VDP implementation. The main reason and motivation for this task to be carried at this time in the VUQ FA is to bring together (i) knowledge of modern view and capability in VUQ, (ii) knowledge of physical processes that govern the CIPS, and (iii) knowledge of codes, models, and data available, used, potentially accessible, and/or being developed in CASL for CIPS prediction, to devise a practical VDP that effectively supports the CASL's mission in CIPS applications.

pH induced polychromatic UV treatment for the removal of a mixture of SMX, OTC and CIP from water

International Nuclear Information System (INIS)

Avisar, D.; Lester, Y.; Mamane, H.

2010-01-01

Water and wastewater effluents contain a vast range of chemicals in mixtures that have different chemical structures and characteristics. This study presents a treatment technology for the removal of mixtures of antibiotic residues (sulfamethoxazole (SMX), oxtetracycline (OTC) and ciprofloxacin (CIP)) from contaminated water. The treatment combines pH modification of the water to an optimal value, followed by a photolytic treatment using direct polychromatic ultraviolet (UV) irradiation by medium pressure UV lamp. The pH adjustment of the treated water leads to structural modifications of the pollutant's molecule thus may enhance direct photolysis by UV light. Results showed that an increase of water pH from 5 to 7 leads to a decrease in degradation rate of SMX and an increase in degradation rate of OTC and CIP, when studied separately and not in a mixture. Thus, the optimal pH values for UV photodegradation in a mixture, involve initial photolysis at pH 5 and then gradually changing the pH from 5 to 7 during the UV exposure. For example, this resulted in 99% degradation of SMX at pH 5 and enhanced degradation of OTC and CIP from 54% and 26% to 91% and 96% respectively when pH was increased from 5 to 7. Thus the pH induced photolytic treatment has a potential in improving treatment of antibiotics in mixtures.

pH induced polychromatic UV treatment for the removal of a mixture of SMX, OTC and CIP from water

Energy Technology Data Exchange (ETDEWEB)

Avisar, D., E-mail: droravi@post.tau.ac.il [Hydro-chemistry Laboratory, Geography and the Environment, Tel Aviv University, Tel Aviv 69978 (Israel); Lester, Y. [Hydro-chemistry Laboratory, Geography and the Environment, Tel Aviv University, Tel Aviv 69978 (Israel); School of Mechanical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 69978 (Israel); Mamane, H. [School of Mechanical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 69978 (Israel)

2010-03-15

Water and wastewater effluents contain a vast range of chemicals in mixtures that have different chemical structures and characteristics. This study presents a treatment technology for the removal of mixtures of antibiotic residues (sulfamethoxazole (SMX), oxtetracycline (OTC) and ciprofloxacin (CIP)) from contaminated water. The treatment combines pH modification of the water to an optimal value, followed by a photolytic treatment using direct polychromatic ultraviolet (UV) irradiation by medium pressure UV lamp. The pH adjustment of the treated water leads to structural modifications of the pollutant's molecule thus may enhance direct photolysis by UV light. Results showed that an increase of water pH from 5 to 7 leads to a decrease in degradation rate of SMX and an increase in degradation rate of OTC and CIP, when studied separately and not in a mixture. Thus, the optimal pH values for UV photodegradation in a mixture, involve initial photolysis at pH 5 and then gradually changing the pH from 5 to 7 during the UV exposure. For example, this resulted in 99% degradation of SMX at pH 5 and enhanced degradation of OTC and CIP from 54% and 26% to 91% and 96% respectively when pH was increased from 5 to 7. Thus the pH induced photolytic treatment has a potential in improving treatment of antibiotics in mixtures.

Up-Regulation of P21 Inhibits TRAIL-Mediated Extrinsic Apoptosis, Contributing Resistance to SAHA in Acute Myeloid Leukemia Cells

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Xing Wu

2014-08-01

Full Text Available Background/Aim: P21, a multifunctional cell cycle-regulatory molecule, regulates apoptotic cell death. In this study we examined the effect of altered p21 expression on the sensitivity of acute myeloid leukemia cells in response to HDAC inhibitor SAHA treatment and investigated the underlying mechanism. Methods: Stably transfected HL60 cell lines were established in RPMI-1640 with supplementation of G-418. Cell viability was measured by MTT assay. Western blot was applied to assess the protein expression levels of target genes. Cell apoptosis was monitored by AnnexinV-PE/7AAD assay. Results: We showed HL60 cells that that didn't up-regulate p21 expression were more sensitive to SAHA-mediated apoptosis than NB4 and U937 cells that had increased p21 level. Enforced expression of p21 in HL60 cells reduced sensitivity to SAHA and blocked TRAIL-mediated apoptosis. Conversely, p21 silencing in NB4 cells enhanced SAHA-mediated apoptosis and lethality. Finally, we found that combined treatment with SAHA and rapamycin down-regulated p21 and enhanced apoptosis in AML cells. Conclusion: We conclude that up-regulated p21 expression mediates resistance to SAHA via inhibition of TRAIL apoptotic pathway. P21 may serve as a candidate biomarker to predict responsiveness or resistance to SAHA-based therapy in AML patients. In addition, rapamycin may be an effective agent to override p21-mediated resistance to SAHA in AML patients.

An independent occurrence of the chimeric P450 enzyme CYP337B3 of Helicoverpa armigera confers cypermethrin resistance in Pakistan.

Science.gov (United States)

Rasool, Akhtar; Joußen, Nicole; Lorenz, Sybille; Ellinger, Renate; Schneider, Bernd; Khan, Sher Afzal; Ashfaq, Muhammad; Heckel, David G

2014-10-01

The increasing resistance level of insect pest species is a major concern to agriculture worldwide. The cotton bollworm, Helicoverpa armigera, is one of the most important pest species due to being highly polyphagous, geographically widespread, and resistant towards many chemical classes of insecticides. We previously described the mechanism of fenvalerate resistance in Australian populations conferred by the chimeric cytochrome P450 monooxygenase CYP337B3, which arose by unequal crossing-over between CYP337B1 and CYP337B2. Here, we show that this mechanism is also present in the cypermethrin-resistant FSD strain from Pakistan. The Pakistani and the Australian CYP337B3 alleles differ by 18 synonymous and three nonsynonymous SNPs and additionally in the length and sequence of the intron. Nevertheless, the activity of both CYP337B3 proteins is comparable. We demonstrate that CYP337B3 is capable of metabolizing cypermethrin (trans- and especially cis-isomers) to the main metabolite 4'-hydroxycypermethrin, which exhibits no intrinsic toxicity towards susceptible larvae. In a bioassay, CYP337B3 confers a 7-fold resistance towards cypermethrin in FSD larvae compared to susceptible larvae from the Australian TWB strain lacking CYP337B3. Linkage analysis shows that presence of CYP337B3 accounts for most of the cypermethrin resistance in the FSD strain; up-regulation of other P450s in FSD plays no detectable role in resistance. The presence or absence of CYP337B3 can be easily detected by a simple PCR screen, providing a powerful tool to rapidly distinguish resistant from susceptible individuals in the field and to determine the geographical distribution of this resistance gene. Our results suggest that CYP337B3 evolved twice independently by unequal crossing-over between CYP337B2 and two different CYP337B1 alleles. Copyright © 2014 Elsevier Ltd. All rights reserved.

The matricellular protein TSP1 promotes human and mouse endothelial cell senescence through CD47 and Nox1.

Science.gov (United States)

Meijles, Daniel N; Sahoo, Sanghamitra; Al Ghouleh, Imad; Amaral, Jefferson H; Bienes-Martinez, Raquel; Knupp, Heather E; Attaran, Shireen; Sembrat, John C; Nouraie, Seyed M; Rojas, Mauricio M; Novelli, Enrico M; Gladwin, Mark T; Isenberg, Jeffrey S; Cifuentes-Pagano, Eugenia; Pagano, Patrick J

2017-10-17

Senescent cells withdraw from the cell cycle and do not proliferate. The prevalence of senescent compared to normally functioning parenchymal cells increases with age, impairing tissue and organ homeostasis. A contentious principle governing this process has been the redox theory of aging. We linked matricellular protein thrombospondin 1 (TSP1) and its receptor CD47 to the activation of NADPH oxidase 1 (Nox1), but not of the other closely related Nox isoforms, and associated oxidative stress, and to senescence in human cells and aged tissue. In human endothelial cells, TSP1 promoted senescence and attenuated cell cycle progression and proliferation. At the molecular level, TSP1 increased Nox1-dependent generation of reactive oxygen species (ROS), leading to the increased abundance of the transcription factor p53. p53 mediated a DNA damage response that led to senescence through Rb and p21 cip , both of which inhibit cell cycle progression. Nox1 inhibition blocked the ability of TSP1 to increase p53 nuclear localization and p21 cip abundance and its ability to promote senescence. Mice lacking TSP1 showed decreases in ROS production, p21 cip expression, p53 activity, and aging-induced senescence. Conversely, lung tissue from aging humans displayed increases in the abundance of vascular TSP1, Nox1, p53, and p21 cip Finally, genetic ablation or pharmacological blockade of Nox1 in human endothelial cells attenuated TSP1-mediated ROS generation, restored cell cycle progression, and protected against senescence. Together, our results provide insights into the functional interplay between TSP1 and Nox1 in the regulation of endothelial senescence and suggest potential targets for controlling the aging process at the molecular level. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Alcohol dehydrogenase 1 (ADH1) confers both abiotic and biotic stress resistance in Arabidopsis.

Science.gov (United States)

Shi, Haitao; Liu, Wen; Yao, Yue; Wei, Yunxie; Chan, Zhulong

2017-09-01

Although the transcriptional regulation and upstream transcription factors of AtADH1 in response to abiotic stress are widely revealed, the in vivo roles of AtADH1 remain unknown. In this study, we found that the expression of AtADH1 was largely induced after salt, drought, cold and pathogen infection. Further studies found that AtADH1 overexpressing plants were more sensitive to abscisic acid (ABA) in comparison to wide type (WT), while AtADH1 knockout mutants showed no significant difference compared with WT in ABA sensitivity. Consistently, AtADH1 overexpressing plants showed improved stress resistance to salt, drought, cold and pathogen infection than WT, but the AtADH1 knockout mutants had no significant difference in abiotic and biotic stress resistance. Moreover, overexpression of AtADH1 expression increased the transcript levels of multiple stress-related genes, accumulation of soluble sugars and callose depositions. All these results indicate that AtADH1 confers enhanced resistance to both abiotic and biotic stresses. Copyright © 2017 Elsevier B.V. All rights reserved.

AMP-18 Targets p21 to Maintain Epithelial Homeostasis.

Science.gov (United States)

Chen, Peili; Li, Yan Chun; Toback, F Gary

2015-01-01

Dysregulated homeostasis of epithelial cells resulting in disruption of mucosal barrier function is an important pathogenic mechanism in inflammatory bowel diseases (IBD). We have characterized a novel gastric protein, Antrum Mucosal Protein (AMP)-18, that has pleiotropic properties; it is mitogenic, anti-apoptotic and can stimulate formation of tight junctions. A 21-mer synthetic peptide derived from AMP-18 exhibits the same biological functions as the full-length protein and is an effective therapeutic agent in mouse models of IBD. In this study we set out to characterize therapeutic mechanisms and identify molecular targets by which AMP-18 maintains and restores disrupted epithelial homeostasis in cultured intestinal epithelial cells and a mouse model of IBD. Tumor necrosis factor (TNF)-α, a pro-inflammatory cytokine known to mediate gastrointestinal (GI) mucosal injury in IBD, was used to induce intestinal epithelial cell injury, and study the effects of AMP-18 on apoptosis and the cell cycle. An apoptosis array used to search for targets of AMP-18 in cells exposed to TNF-α identified the cyclin-dependent kinase inhibitor p21 WAF1/CIP1. Treatment with AMP-18 blunted increases in p21 expression and apoptosis, while reversing disturbed cell cycle kinetics induced by TNF-α. AMP-18 appears to act through PI3K/AKT pathways to increase p21 phosphorylation, thereby reducing its nuclear accumulation to overcome the antiproliferative effects of TNF-α. In vitamin D receptor-deficient mice with TNBS-induced IBD, the observed increase in p21 expression in colonic epithelial cells was suppressed by treatment with AMP peptide. The results indicate that AMP-18 can maintain and/or restore the homeostatic balance between proliferation and apoptosis in intestinal epithelial cells to protect and repair mucosal barrier homeostasis and function, suggesting a therapeutic role in IBD.

AMP-18 Targets p21 to Maintain Epithelial Homeostasis.

Directory of Open Access Journals (Sweden)

Peili Chen

Full Text Available Dysregulated homeostasis of epithelial cells resulting in disruption of mucosal barrier function is an important pathogenic mechanism in inflammatory bowel diseases (IBD. We have characterized a novel gastric protein, Antrum Mucosal Protein (AMP-18, that has pleiotropic properties; it is mitogenic, anti-apoptotic and can stimulate formation of tight junctions. A 21-mer synthetic peptide derived from AMP-18 exhibits the same biological functions as the full-length protein and is an effective therapeutic agent in mouse models of IBD. In this study we set out to characterize therapeutic mechanisms and identify molecular targets by which AMP-18 maintains and restores disrupted epithelial homeostasis in cultured intestinal epithelial cells and a mouse model of IBD. Tumor necrosis factor (TNF-α, a pro-inflammatory cytokine known to mediate gastrointestinal (GI mucosal injury in IBD, was used to induce intestinal epithelial cell injury, and study the effects of AMP-18 on apoptosis and the cell cycle. An apoptosis array used to search for targets of AMP-18 in cells exposed to TNF-α identified the cyclin-dependent kinase inhibitor p21 WAF1/CIP1. Treatment with AMP-18 blunted increases in p21 expression and apoptosis, while reversing disturbed cell cycle kinetics induced by TNF-α. AMP-18 appears to act through PI3K/AKT pathways to increase p21 phosphorylation, thereby reducing its nuclear accumulation to overcome the antiproliferative effects of TNF-α. In vitamin D receptor-deficient mice with TNBS-induced IBD, the observed increase in p21 expression in colonic epithelial cells was suppressed by treatment with AMP peptide. The results indicate that AMP-18 can maintain and/or restore the homeostatic balance between proliferation and apoptosis in intestinal epithelial cells to protect and repair mucosal barrier homeostasis and function, suggesting a therapeutic role in IBD.

qnrA6 genetic environment and quinolone resistance conferred on Proteus mirabilis.

Science.gov (United States)

Jayol, Aurélie; Janvier, Frédéric; Guillard, Thomas; Chau, Françoise; Mérens, Audrey; Robert, Jérôme; Fantin, Bruno; Berçot, Béatrice; Cambau, Emmanuelle

2016-04-01

To determine the genetic location and environment of the qnrA6 gene in Proteus mirabilis PS16 where it was first described and to characterize the quinolone resistance qnrA6 confers. Transformation experiments and Southern blotting were performed for plasmid and genomic DNA of P. mirabilis PS16 to determine the qnrA6 location. Combinatorial PCRs with primers in qnrA6 and genes usually surrounding qnrA genes were used to determine the genetic environment. The qnrA6 coding region, including or not the promoter region, was cloned into vectors pTOPO and pBR322 and the MICs of six quinolones were measured for transformants of Escherichia coli TOP10 and P. mirabilis ATCC 29906 Rif(R). qnrA6 was shown to be chromosomally encoded in P. mirabilis PS16 and its genetic environment was 81%-87% similar to that of qnrA2 in the Shewanella algae chromosome. The 5138 bp region up- and downstream of qnrA6 contained an IS10 sequence surrounded by two ISCR1. This resulted in qnrA6 being displaced 1.9 kb from its native promoter but supplied a promoter present in ISCR1. qnrA6 cloned into pTOPO and pBR322 conferred a 4-32-fold increase in fluoroquinolone MICs when expressed in E. coli but only 2-3-fold in P. mirabilis. When including the promoter region, a further increase in resistance was observed in both species, reaching MIC values above clinical breakpoints for only P. mirabilis. qnrA6 is the first chromosomally located qnrA gene described in Enterobacteriaceae. The quinolone resistance conferred by qnrA6 depends on the proximity of an efficient promoter and the host strain where it is expressed. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Cdk5 inhibitory peptide (CIP inhibits Cdk5/p25 activity induced by high glucose in pancreatic beta cells and recovers insulin secretion from p25 damage.

Directory of Open Access Journals (Sweden)

Ya-Li Zheng

Full Text Available Cdk5/p25 hyperactivity has been demonstrated to lead to neuron apoptosis and degenerations. Chronic exposure to high glucose (HG results in hyperactivity of Cdk5 and reduced insulin secretion. Here, we set out to determine whether abnormal upregulation of Cdk5/p25 activity may be induced in a pancreatic beta cell line, Min6 cells. We first confirmed that p25 were induced in overexpressed p35 cells treated with HG and increased time course dependence. Next, we showed that no p25 was detected under short time HG stimulation (4-12 hrs, however was detectable in the long exposure in HG cells (24 hrs and 48 hrs. Cdk5 activity in the above cells was much higher than low glucose treated cells and resulted in more than 50% inhibition of insulin secretion. We confirmed these results by overexpression of p25 in Min6 cells. As in cortical neurons, CIP, a small peptide, inhibited Cdk5/p25 activity and restored insulin secretion. The same results were detected in co-infection of dominant negative Cdk5 (DNCdk5 with p25. CIP also reduced beta cells apoptosis induced by Cdk5/p25. These studies indicate that Cdk5/p25 hyperactivation deregulates insulin secretion and induces cell death in pancreatic beta cells and suggests that CIP may serve as a therapeutic agent for type 2 diabetes.

Second generation tyrosine kinase inhibitors prevent disease progression in high-risk (high CIP2A) chronic myeloid leukaemia patients.

Science.gov (United States)

Lucas, C M; Harris, R J; Holcroft, A K; Scott, L J; Carmell, N; McDonald, E; Polydoros, F; Clark, R E

2015-07-01

High cancerous inhibitor of PP2A (CIP2A) protein levels at diagnosis of chronic myeloid leukaemia (CML) are predictive of disease progression in imatinib-treated patients. It is not known whether this is true in patients treated with second generation tyrosine kinase inhibitors (2G TKI) from diagnosis, and whether 2G TKIs modulate the CIP2A pathway. Here, we show that patients with high diagnostic CIP2A levels who receive a 2G TKI do not progress, unlike those treated with imatinib (P=<0.0001). 2G TKIs induce more potent suppression of CIP2A and c-Myc than imatinib. The transcription factor E2F1 is elevated in high CIP2A patients and following 1 month of in vivo treatment 2G TKIs suppress E2F1 and reduce CIP2A; these effects are not seen with imatinib. Silencing of CIP2A, c-Myc or E2F1 in K562 cells or CML CD34+ cells reactivates PP2A leading to BCR-ABL suppression. CIP2A increases proliferation and this is only reduced by 2G TKIs. Patients with high CIP2A levels should be offered 2G TKI treatment in preference to imatinib. 2G TKIs disrupt the CIP2A/c-Myc/E2F1 positive feedback loop, leading to lower disease progression risk. The data supports the view that CIP2A inhibits PP2Ac, stabilising E2F1, creating a CIP2A/c-Myc/E2F1 positive feedback loop, which imatinib cannot overcome.

Loss of the RNA polymerase III repressor MAF1 confers obesity resistance.

OpenAIRE

Bonhoure, N.; Byrnes, A.; Moir, R.D.; Hodroj, W.; Preitner, F.; Praz, V.; Marcelin, G.; Chua, S.C.; Martinez-Lopez, N.; Singh, R.; Moullan, N.; Auwerx, J.; Willemin, G.; Shah, H.; Hartil, K.

2015-01-01

MAF1 is a global repressor of RNA polymerase III transcription that regulates the expression of highly abundant noncoding RNAs in response to nutrient availability and cellular stress. Thus, MAF1 function is thought to be important for metabolic economy. Here we show that a whole-body knockout of Maf1 in mice confers resistance to diet-induced obesity and nonalcoholic fatty liver disease by reducing food intake and increasing metabolic inefficiency. Energy expenditure in Maf1(-/-) mice is inc...

Neuroendocrine prostate cancer (NEPCa) increased the neighboring PCa chemo-resistance via altering the PTHrP/p38/Hsp27/androgen receptor (AR)/p21 signals

Science.gov (United States)

Cui, Yun; Sun, Yin; Hu, Shuai; Luo, Jie; Li, Lei; Li, Xin; Yeh, Shuyuan; Jin, Jie; Chang, Chawnshang

2016-01-01

Prostatic neuroendocrine cells (NE) are an integral part of prostate cancer (PCa) that are associated with PCa progression. As the current androgen-deprivation therapy (ADT) with anti-androgens may promote the neuroendocrine PCa (NEPCa) development, and few therapies can effectively suppress NEPCa, understanding the impact of NEPCa on PCa progression may help us to develop better therapies to battle PCa. Here we found NEPCa cells could increase the docetaxel-resistance of their neighboring PCa cells. Mechanism dissection revealed that through secretion of PTHrP, NEPCa cells could alter the p38/MAPK/Hsp27 signals in their neighboring PCa cells that resulted in increased androgen receptor (AR) activity via promoting AR nuclear translocation. The consequences of increased AR function might then increase docetaxel-resistance via increasing p21 expression. In vivo xenograft mice experiments also confirmed NEPCa could increase the docetaxel-resistance of neighboring PCa, and targeting this newly identified PTHrP/p38/Hsp27/AR/p21 signaling pathway with either p38 inhibitor (SB203580) or sh-PTHrP may result in improving/restoring the docetaxel sensitivity to better suppress PCa. PMID:27375022

Effect of material selection and background impurity on interface property and resulted CIP-GMR performance

International Nuclear Information System (INIS)

Peng Xilin; Morrone, Augusto; Nikolaev, Konstantin; Kief, Mark; Ostrowski, Mark

2009-01-01

In this paper, we investigated the effect of background base pressure, wafer-transferring time between process modules, and stack layer material selection on the current-in-plane giant magneto-resistive (CIP-GMR) interface properties and the resulted CIP-GMR performance. Experimental results showed that seed layer/AFM interface, AFM/pinned layer (PL) interface, pinned layer/Ru interface, and reference layer (RL)/Cu spacer interface are among the most critical ones for a CIP-GMR device. By reducing the background impurity level (water moisture and oxygen), optimizing the wafer process flow sequence, and careful stack-layer material selection, such critical interfaces in a CIP-GMR device can be preserved. Consequently, a much robust GMR performance control can be achieved.

HIVR4P 2016, Partnering for Prevention: Conference Summary and Highlights.

Science.gov (United States)

Shacklett, Barbara L; Derdeyn, Cynthia A; Folayan, Morenike Oluwatoyin; Landovitz, Raphael J; Anthony, Colin; Behrens, Anna-Janina; Hope, Thomas J; Landais, Elise; Leal, Lorna; Marrazzo, Jeanne M; Morris, Lynn; Mugo, Nelly; Ngure, Kenneth; Noseda, Veronica; Ranasinghe, Srinika; Tully, Damien C; Voronin, Yegor; Warren, Mitchell; Wibmer, Constantinos Kurt; Xie, Irene Y; Scarlatti, Gabriella; Thyagarajan, Bargavi

2017-08-01

HIV Research for Prevention: AIDS Vaccine, Microbicide, and ARV-based Prevention Science (HIVR4P) was built on a growing consensus that effective HIV prevention requires a combination of approaches and that understanding, analyzing, and debating the cross-cutting issues that impact prevention research are all essential to combat the global HIV/AIDS epidemic. To that end, the biennial HIVR4P conference is dedicated to all biomedical HIV prevention research approaches, including HIV vaccines, microbicides, pre-exposure prophylaxis, and treatment as prevention. The HIVR4P 2016 conference was held in Chicago, Illinois (USA), on October 17-21, and included more than 700 scientific presentations and 21 satellite sessions covering the latest and most promising advances across the HIV prevention research field. The theme "Partnering for Prevention" represented the conference's commitment to breaking down silos between research disciplines as well as between researchers, program developers, care providers, advocates, communities, and funders. Delegates spanning 42 countries attended the conference. One-third of those in attendance were early career investigators, which reflects a firm commitment to emerging researchers and ultimately to the goal of developing a sustainable scientific enterprise well into the future. This article presents a concise summary of highlights from the conference. For a more detailed account, one may find full abstracts, daily summaries, and webcasts on the conference website at hivr4p.org.

Crystallization and preliminary diffraction studies of SFC-1, a carbapenemase conferring antibiotic resistance

International Nuclear Information System (INIS)

Hong, Myoung-Ki; Lee, Jae Jin; Wu, Xing; Kim, Jin-Kwang; Jeong, Byeong Chul; Pham, Tan-Viet; Kim, Seung-Hwan; Lee, Sang Hee; Kang, Lin-Woo

2012-01-01

The SFC-1 gene from S. fonticola was cloned and SFC-1 was expressed, purified and crystallized. X-ray diffraction data were collected from an SFC-1 crystal to 1.6 Å resolution. SFC-1, a class A carbapenemase that confers antibiotic resistance, hydrolyzes the β-lactam rings of β-lactam antibiotics (carbapenems, cephalosporins, penicillins and aztreonam). SFC-1 presents an enormous challenge to infection control, particularly in the eradication of Gram-negative pathogens. As SFC-1 exhibits a remarkably broad substrate range, including β-lactams of all classes, the enzyme is a potential target for the development of antimicrobial agents against pathogens producing carbapenemases. In this study, SFC-1 was cloned, overexpressed, purified and crystallized. The SFC-1 crystal diffracted to 1.6 Å resolution and belonged to the orthorhombic space group P2 1 2 1 2 1 , with unit-cell parameters a = 65.8, b = 68.3, c = 88.8 Å. Two molecules are present in the asymmetric unit, with a corresponding V M of 1.99 Å 3 Da −1 and a solvent content of 38.1%

Simultaneous human papilloma virus type 16 E7 and cdk inhibitor p21 expression induces apoptosis and cathepsin B activation

International Nuclear Information System (INIS)

Kaznelson, Dorte Wissing; Bruun, Silas; Monrad, Astrid; Gjerloev, Simon; Birk, Jesper; Roepke, Carsten; Norrild, Bodil

2004-01-01

Human papillomavirus type 16 (HPV-16) is the major risk factor for development of cervical cancer. The major oncoprotein E7 enhances cell growth control. However, E7 has in some reports been shown to induce apoptosis suggesting that there is a delicate balance between cell proliferation and induction of cell death. We have used the osteosarcoma cell line U2OS cells provided with E7 and the cdk2 inhibitor p21 (cip1/waf1) under inducible control, as a model system for the analysis of E7-mediated apoptosis. Our data shows that simultaneous expression of E7 and p21 proteins induces cell death, possibly because of conflicting growth control. Interestingly, E7/p21-induced cell death is associated with the activation of a newly identified mediator of apoptosis, namely cathepsin B. Activation of the cellular caspases is undetectable in cells undergoing E7/p21-induced apoptosis. To our knowledge, this is the first time a role for cathepsin B is reported in HPV-induced apoptotic signalling

Overexpression of 15-lipoxygenase-1 induces growth arrest through phosphorylation of p53 in human colorectal cancer cells.

Science.gov (United States)

Kim, Jong-Sik; Baek, Seung Joon; Bottone, Frank G; Sali, Tina; Eling, Thomas E

2005-09-01

To investigate the function of 15-lipoxygenase-1 (15-LOX-1) in human colorectal cancer, we overexpressed 15-LOX-1 in HCT-116 human colorectal cancer cells. Clones expressing the highest levels of 15-LOX-1 displayed reduced viability compared with the HCT-116-Vector control cells. Further, by cell cycle gene array analyses, the cyclin-dependent kinase inhibitor p21WAF1/CIP1 and MDM2 genes were up-regulated in 15-LOX-1-overexpressing cells. The induction of p21(WAF1/CIP1) and MDM2 were linked to activation of p53 by 15-LOX-1, as there was a dramatic induction of phosphorylated p53 (Ser15) in 15-LOX-1-overesxpressing cells. However, the 15-LOX-1 metabolites 13(S)-hydroxyoctadecadienoic acid and 15(S)-hydroxyeicosatetraenoic acid failed to induce phosphorylation of p53 at Ser15, and the 15-LOX-1 inhibitor PD146176 did not inhibit the phosphorylation of p53 at Ser15 in 15-LOX-1-overexpressing cells. Nonetheless, the growth-inhibitory effects of 15-LOX-1 were p53 dependent, as 15-LOX-1 overexpression had no effect on cell growth in p53 (-/-) HCT-116 cells. Finally, treatment of HCT-116-15-LOX-1 cells with different kinase inhibitors suggested that the effects of 15-LOX-1 on p53 phosphorylation and activation were due to effects on DNA-dependent protein kinase. Collectively, these findings suggest a new mechanism to explain the biological activity of 15-LOX-1, where 15-LOX plays a stoichiometric role in activating a DNA-dependent protein kinase-dependent pathway that leads to p53-dependent growth arrest.

P-glycoprotein confers acquired resistance to 17-DMAG in lung cancers with an ALK rearrangement

International Nuclear Information System (INIS)

Kim, Hee Joung; Lee, Kye Young; Kim, Young Whan; Choi, Yun Jung; Lee, Jung-Eun; Choi, Chang Min; Baek, In-Jeoung; Rho, Jin Kyung; Lee, Jae Cheol

2015-01-01

Because anaplastic lymphoma kinase (ALK) is dependent on Hsp90 for protein stability, Hsp90 inhibitors are effective in controlling growth of lung cancer cells with ALK rearrangement. We investigated the mechanism of acquired resistance to 17-(Dimethylaminoethylamino)-17-demethoxygeldanamycin (17-DMAG), a geldanamycin analogue Hsp90 inhibitor, in H3122 and H2228 non-small cell lung cancer cell lines with ALK rearrangement. Resistant cell lines (H3122/DR-1, H3122/DR-2 and H2228/DR) were established by repeated exposure to increasing concentrations of 17-DMAG. Mechanisms for resistance by either NAD(P)H/quinone oxidoreductase 1 (NQO1), previously known as a factor related to 17-DMAG resistance, or P-glycoprotein (P-gp; ABCB1/MDR1) were queried using RT-PCR, western blot analysis, chemical inhibitors, the MTT cell proliferation/survival assay, and cellular efflux of rhodamine 123. The resistant cells showed no cross-resistance to AUY922 or ALK inhibitors, suggesting that ALK dependency persists in cells with acquired resistance to 17-DMAG. Although expression of NQO1 was decreased in H3122/DR-1 and H3122/DR-2, NQO1 inhibition by dicumarol did not affect the response of parental cells (H2228 and H3122) to 17-DMAG. Interestingly, all resistant cells showed the induction of P-gp at the protein and RNA levels, which was associated with an increased efflux of the P-gp substrate rhodamine 123 (Rho123). Transfection with siRNA directed against P-gp or treatment with verapamil, an inhibitor of P-gp, restored the sensitivity to the drug in all cells with acquired resistance to 17-DMAG. Furthermore, we also observed that the growth-inhibitory effect of 17-DMAG was decreased in A549/PR and H460/PR cells generated to over-express P-gp by long-term exposure to paclitaxel, and these cells recovered their sensitivity to 17-DMAG through the inhibition of P-gp. P-gp over-expression is a possible mechanism of acquired resistance to 17-DMAG in cells with ALK rearrangement. The online

21 CFR 514.5 - Presubmission conferences.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Presubmission conferences. 514.5 Section 514.5... presubmission conference must be submitted to FDA in a signed letter. The letter must include a proposed agenda... calendar days before a scheduled presubmission conference, a detailed agenda, a copy of any materials to be...

Durable broad-spectrum powdery mildew resistance in pea er1 plants is conferred by natural loss-of-function mutations in PsMLO1

NARCIS (Netherlands)

Humphry, M.; Reinstädler, A.; Ivanov, S.; Bisseling, T.; Panstruga, R.

2011-01-01

Loss-of-function alleles of plant-specific MLO (Mildew Resistance Locus O) genes confer broad-spectrum powdery mildew resistance in monocot (barley) and dicot (Arabidopsis thaliana, tomato) plants. Recessively inherited powdery mildew resistance in pea (Pisum sativum) er1 plants is, in many aspects,

An AFLP marker linked to the Pm-1 gene that confers resistance to Podosphaera xanthii race 1 in Cucumis melo

Directory of Open Access Journals (Sweden)

Ana Paula Matoso Teixeira

2008-01-01

Full Text Available Brazil produced 330,000 metric tons of melons in 2005, principally in the Northeast region where one of the most important melon pathogens is the powdery mildew fungus Podosphaera xanthii. The disease is controlled mainly by incorporating single dominant resistance genes into commercial hybrids. We report on linkage analysis of the Pm-1 resistance gene, introgressed from the AF125Pm-1 Cantalupensis Charentais-type breeding line into the yellow-fleshed melon (Group Inodorus breeding line AF426-S by backcrossing to produce the resistant line AF426-R, and the amplified fragment length polymorphism (AFLP marker M75/H35_155 reported to be polymorphic between AF426-S and AF426-R. Segregation analysis of M75/H35_155 using a backcross population of 143 plants derived from [AF426-R x AF426-S] x AF426-S and screened for resistance to P. xanthii race 1 produced a recombination frequency of 4.9%, indicating close linkage between M75/H35_155 and Pm-1. Using the same segregating population, the M75/H35_155 marker had previously been reported to be distantly linked to Prv¹, a gene conferring resistance to papaya ringspot virus-type W. Since M75/H35_155 is linked to Prv¹ at a distance of 40.9 cM it is possible that Pm-1 and Prv¹ are also linked.

Expression of the grape VqSTS21 gene in Arabidopsis confers resistance to osmotic stress and biotrophic pathogens but not Botrytis cinerea

Directory of Open Access Journals (Sweden)

Li Huang

2016-09-01

Full Text Available Stilbene synthase (STS is a key gene in the biosynthesis of various stilbenoids, including resveratrol and its derivative glucosides (such as piceid, that has been shown to contribute to disease resistance in plants. However, the mechanism behind such a role has yet to be elucidated. Furthermore, the function of STS genes in osmotic stress tolerance remains unclear. As such, we sought to elucidate the role of STS genes in the defense against biotic and abiotic stress in the model plant Arabidopsis thaliana. Expression profiling of 31 VqSTS genes from Vitis quinquangularis revealed that VqSTS21 was up-regulated in response to powdery mildew (PM infection. To provide a deeper understanding of the function of this gene, we cloned the full-length coding sequence of VqSTS21 and overexpressed it in Arabidopsis thaliana via Agrobacterium-mediated transformation. The resulting VqSTS21 Arabidopsis lines produced trans-piceid rather than resveratrol as their main stilbenoid product and exhibited improved disease resistance to PM and Pseudomonas syringae pv. tomato DC3000, but displayed increased susceptibility to Botrytis cinerea. In addition, transgenic Arabidopsis lines were found to confer tolerance to salt and drought stress from seed germination through plant maturity. Intriguingly, qPCR assays of defense-related genes involved in salicylic acid, jasmonic acid, and abscisic acid-induced signaling pathways in these transgenic lines suggested that VqSTS21 plays a role in various phytohormone-related pathways, providing insight into the mechanism behind VqSTS21-mediated resistance to biotic and abiotic stress.

3,3'-Diindolylmethane is a novel mitochondrial H(+)-ATP synthase inhibitor that can induce p21(Cip1/Waf1) expression by induction of oxidative stress in human breast cancer cells.

Science.gov (United States)

Gong, Yixuan; Sohn, Heesook; Xue, Ling; Firestone, Gary L; Bjeldanes, Leonard F

2006-05-01

Epidemiologic evidence suggests that high dietary intake of Brassica vegetables, such as broccoli, cabbage, and Brussels sprouts, protects against tumorigenesis in multiple organs. 3,3'-Diindolylmethane, one of the active products derived from Brassica vegetables, is a promising antitumor agent. Previous studies in our laboratory showed that 3,3'-diindolylmethane induced a G(1) cell cycle arrest in human breast cancer MCF-7 cells by a mechanism that included increased expression of p21. In the present study, the upstream events leading to p21 overexpression were further investigated. We show for the first time that 3,3'-diindolylmethane is a strong mitochondrial H(+)-ATPase inhibitor (IC(50) approximately 20 micromol/L). 3,3'-Diindolylmethane treatment induced hyperpolarization of mitochondrial inner membrane, decreased cellular ATP level, and significantly stimulated mitochondrial reactive oxygen species (ROS) production. ROS production, in turn, led to the activation of stress-activated pathways involving p38 and c-Jun NH(2)-terminal kinase. Using specific kinase inhibitors (SB203580 and SP600125), we showed the central role of p38 and c-Jun NH(2)-terminal kinase (JNK) pathways in 3,3'-diindolylmethane-induced p21 mRNA transcription. In addition, antioxidants significantly attenuated 3,3'-diindolylmethane-induced activation of p38 and JNK and induction of p21, indicating that oxidative stress is the major trigger of these events. To further support the role of ROS in 3,3'-diindolylmethane-induced p21 overexpression, we showed that 3,3'-diindolylmethane failed to induce p21 overexpression in mitochondrial respiratory chain deficient rho(0) MCF-7 cells, in which 3,3'-diindolylmethane did not stimulate ROS production. Thus, we have established the critical role of enhanced mitochondrial ROS release in 3,3'-diindolylmethane-induced p21 up-regulation in human breast cancer cells.

The Heparanase Inhibitor PG545 Attenuates Colon Cancer Initiation and Growth, Associating with Increased p21 Expression

Directory of Open Access Journals (Sweden)

Preeti Singh

2017-03-01

Full Text Available Heparanase activity is highly implicated in cellular invasion and tumor metastasis, a consequence of cleavage of heparan sulfate and remodeling of the extracellular matrix underlying epithelial and endothelial cells. Heparanase expression is rare in normal epithelia, but is often induced in tumors, associated with increased tumor metastasis and poor prognosis. In addition, heparanase induction promotes tumor growth, but the molecular mechanism that underlines tumor expansion by heparanase is still incompletely understood. Here, we provide evidence that heparanase down regulates the expression of p21 (WAF1/CIP1, a cyclin-dependent kinase inhibitor that attenuates the cell cycle. Notably, a reciprocal effect was noted for PG545, a potent heparanase inhibitor. This compound efficiently reduced cell proliferation, colony formation, and tumor xenograft growth, associating with a marked increase in p21 expression. Utilizing the APC Min+/− mouse model, we show that heparanase expression and activity are increased in small bowel polyps, whereas polyp initiation and growth were significantly inhibited by PG545, again accompanied by a prominent induction of p21 levels. Down-regulation of p21 expression adds a novel feature for the emerging pro-tumorigenic properties of heparanase, while the potent p21 induction and anti-tumor effect of PG545 lends optimism that it would prove an efficacious therapeutic in colon carcinoma patients.

A novel radiation-induced p53 mutation is not implicated in radiation resistance via a dominant-negative effect.

Directory of Open Access Journals (Sweden)

Yunguang Sun

Full Text Available Understanding the mutations that confer radiation resistance is crucial to developing mechanisms to subvert this resistance. Here we describe the creation of a radiation resistant cell line and characterization of a novel p53 mutation. Treatment with 20 Gy radiation was used to induce mutations in the H460 lung cancer cell line; radiation resistance was confirmed by clonogenic assay. Limited sequencing was performed on the resistant cells created and compared to the parent cell line, leading to the identification of a novel mutation (del at the end of the DNA binding domain of p53. Levels of p53, phospho-p53, p21, total caspase 3 and cleaved caspase 3 in radiation resistant cells and the radiation susceptible (parent line were compared, all of which were found to be similar. These patterns held true after analysis of p53 overexpression in H460 cells; however, H1299 cells transfected with mutant p53 did not express p21, whereas those given WT p53 produced a significant amount, as expected. A luciferase assay demonstrated the inability of mutant p53 to bind its consensus elements. An MTS assay using H460 and H1299 cells transfected with WT or mutant p53 showed that the novel mutation did not improve cell survival. In summary, functional characterization of a radiation-induced p53 mutation in the H460 lung cancer cell line does not implicate it in the development of radiation resistance.

The P450 CYP6Z1 confers carbamate/pyrethroid cross-resistance in a major African malaria vector beside a novel carbamate-insensitive N485I acetylcholinesterase-1 mutation.

Science.gov (United States)

Ibrahim, Sulaiman S; Ndula, Miranda; Riveron, Jacob M; Irving, Helen; Wondji, Charles S

2016-07-01

Carbamates are increasingly used for vector control notably in areas with pyrethroid resistance. However, a cross-resistance between these insecticides in major malaria vectors such as Anopheles funestus could severely limit available resistance management options. Unfortunately, the molecular basis of such cross-resistance remains uncharacterized in An. funestus, preventing effective resistance management. Here, using a genomewide transcription profiling, we revealed that metabolic resistance through upregulation of cytochrome P450 genes is driving carbamate resistance. The P450s CYP6P9a, CYP6P9b and CYP6Z1 were the most upregulated detoxification genes in the multiple resistant mosquitoes. However, in silico docking simulations predicted CYP6Z1 to metabolize both pyrethroids and carbamates, whereas CYP6P9a and CYP6P9b were predicted to metabolize only the pyrethroids. Using recombinant enzyme metabolism and inhibition assays, we demonstrated that CYP6Z1 metabolizes bendiocarb and pyrethroids, whereas CYP6P9a and CYP6P9b metabolize only the pyrethroids. Other upregulated gene families in resistant mosquitoes included several cuticular protein genes suggesting a possible reduced penetration resistance mechanism. Investigation of the target-site resistance in acetylcholinesterase 1 (ace-1) gene detected and established the association between the new N485I mutation and bendiocarb resistance (odds ratio 7.3; P resistance and improve the design of effective resistance management strategies to control this malaria vector. © 2016 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

Effect of the bio-absorbent on the microwave absorption property of the flaky CIPs/rubber absorbers

Energy Technology Data Exchange (ETDEWEB)

Cheng, Yang; Xu, Yonggang, E-mail: xuyonggang221@163.com; Cai, Jun; Yuan, Liming; Zhang, Deyuan

2015-09-01

Microwave absorbing composites filled with flaky carbonyl iron particles (CIPs) and the bio-absorbent were prepared by using a two-roll mixer and a vulcanizing machine. The electromagnetic (EM) parameters were measured by a vector network analyzer and the reflection loss (RL) was measured by the arch method in the frequency range of 1–4 GHz. The uniform dispersion of the absorbents was verified by comparing the calculated RL with the measured one. The results confirm that as the bio-absorbent was added, the permittivity was increased due to the volume content of absorbents, and the permeability was enlarged owing to the volume content of CIPs and interactions between the two absorbents. The composite filled with bio-absorbents achieved an excellent absorption property at a thickness of 1 mm (minimum RL reaches −7.8 dB), and as the RL was less than −10 dB the absorption band was widest (2.1–3.8 GHz) at a thickness of 2 mm. Therefore, the bio-absorbent is a promising additive candidate on fabricating microwave absorbing composites with a thinner thickness and wider absorption band. - Graphical abstract: Morphology of composites filled with flaky CIPs and the bio-absorbent. The enhancement of bio-absorbent on the electromagnetic absorption property of composites filled with flaky carbonyl iron particles (CIPs) is attributed to the interaction of the two absorbents. The volume content of the FCMPs with the larger shape CIPs play an important role in this effects, the composites filled with irons and bio-absorbents can achieve wider-band and thinner-thickness absorbing materials. - Highlights: • Absorbers filled with bio-absorbents and CIPs was fabricated. • Bio-absorbents enhanced the permittivity and permeability of the composites. • The absorbent interactions play a key role in the enhancement mechanism. • Bio-absorbents enhanced the composite RL in 1–4 GHz.

pOsNAR2.1:OsNAR2.1 expression enhances nitrogen uptake efficiency and grain yield in transgenic rice plants.

Science.gov (United States)

Chen, Jingguang; Fan, Xiaoru; Qian, Kaiyun; Zhang, Yong; Song, Miaoquan; Liu, Yu; Xu, Guohua; Fan, Xiaorong

2017-10-01

The nitrate (NO3-) transporter has been selected as an important gene maker in the process of environmental adoption in rice cultivars. In this work, we transferred another native OsNAR2.1 promoter with driving OsNAR2.1 gene into rice plants. The transgenic lines with exogenous pOsNAR2.1:OsNAR2.1 constructs showed enhanced OsNAR2.1 expression level, compared with wild type (WT), and 15 N influx in roots increased 21%-32% in response to 0.2 mm and 2.5 mm 15NO3- and 1.25 mm 15 NH 4 15 NO 3 . Under these three N conditions, the biomass of the pOsNAR2.1:OsNAR2.1 transgenic lines increased 143%, 129% and 51%, and total N content increased 161%, 242% and 69%, respectively, compared to WT. Furthermore in field experiments we found the grain yield, agricultural nitrogen use efficiency (ANUE), and dry matter transfer of pOsNAR2.1:OsNAR2.1 plants increased by about 21%, 22% and 21%, compared to WT. We also compared the phenotypes of pOsNAR2.1:OsNAR2.1 and pOsNAR2.1:OsNRT2.1 transgenic lines in the field, found that postanthesis N uptake differed significantly between them, and in comparison with the WT. Postanthesis N uptake (PANU) increased approximately 39% and 85%, in the pOsNAR2.1:OsNAR2.1 and pOsNAR2.1:OsNRT2.1 transgenic lines, respectively, possibly because OsNRT2.1 expression was less in the pOsNAR2.1:OsNAR2.1 lines than in the pOsNAR2.1:OsNRT2.1 lines during the late growth stage. These results show that rice NO 3 - uptake, yield and NUE were improved by increased OsNAR2.1 expression via its native promoter. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

Analysis of acetohydroxyacid synthase1 gene in chickpea conferring resistance to imazamox herbicide.

Science.gov (United States)

Jain, Parul; Tar'an, Bunyamin

2014-11-01

Chickpea (Cicer arietinum L.) production in the Canadian prairies is challenging due to a lack of effective weed management mainly because of poor competition ability of the crop and limited registered herbicide options. Chickpea genotype with resistance to imidazolinone (IMI) herbicides has been identified. A point mutation in the acetohydroxyacid synthase1 (AHAS1) gene at C581 to T581, resulting in an amino acid substitution from Ala194 to Val194 (position 205, standardized to arabidopsis), confers the resistance to imazamox in chickpea. However, the molecular mechanism leading to the resistance is not fully understood. In many plant species, contrasting transcription levels of AHAS gene has been implicated in the resistant and susceptible genotypes in response to IMI. The objectives of this research were to compare the AHAS gene expression and AHAS enzyme activity in resistant and susceptible chickpea cultivars in response to imazamox herbicide treatment. Results from RT-qPCR indicated that there is no significant change in the transcript levels of AHAS1 between the susceptible and the resistant genotypes in response to imazamox treatment. Protein hydrophobic cluster analysis, protein-ligand docking analysis, and AHAS enzyme activity assay all indicated that the resistance to imazamox in chickpea is due to the alteration of interaction of the AHAS1 enzyme with the imazamox herbicide.

Marker-Assisted Selection of Xa21 Conferring Resistance to Bacterial Leaf Blight in indica Rice Cultivar LT2

Institute of Scientific and Technical Information of China (English)

Hue Thi NGUYEN; Trung Nguyen DINH; Nakano TOSHITSUGU; Liet Van VU; Quang Hong VU; Tan Van MAI; Thu Thi NGUYEN; Lam Duc VU; Tung Thanh NGUYEN; Long Viet NGUYEN; Hien Thu Thi VU; Hue Thi NONG

2018-01-01

Bacterial leaf blight of rice (BLB), caused by Xanthomonas oryzae pv. oryzae, is one of the most destructive diseases in Asian rice fields. A high-quality rice variety, LT2, was used as the recipient parent. IRBB21, which carries the Xa21 gene, was used as the donor parent. The resistance gene Xa21 was introduced into LT2 by marker-assisted backcrossing. Three Xoo races were used to inoculate the improved lines following the clipping method. Eleven BC3F3lines carrying Xa21 were obtained based on molecular markers and agronomic performance. The 11 lines were then inoculated with the three Xoo races. All the 11 improved lines showed better resistance to BLB than the recipient parent LT2. Based on the level of resistance to BLB and their agronomic performance, five lines (BC3F35.1.5.1, BC3F35.1.5.12, BC3F38.5.6.44, BC3F3 9.5.4.1 and BC3F39.5.4.23) were selected as the most promising for commercial release. These improved lines could contribute to rice production in terms of food security.

Heat-resistant materials 2. Conference proceedings of the 2. international conference on heat-resistant materials

International Nuclear Information System (INIS)

Natesan, K.; Ganesan, P.; Lai, G.Y.

1995-01-01

The Second International Conference on Heat-Resistant Materials was held in Gatlinburg, Tennessee, September 11--14, 1995 and focused on materials performance in cross-cutting technologies where heat resistant materials play a large and sometimes life-and performance-limiting roles in process schemes. The scope of materials for heat-resistant applications included structural iron- and nickel-base alloys, intermetallics, and ceramics. The conference focused on materials development, performance of materials in simulated laboratory and actual service environments on mechanical and structural integrity of components, and state-of-the-art techniques for processing and evaluating materials performance. The three keynote talks described the history of heat-resistant materials, relationship between microstructure and mechanical behavior, and applications of these materials in process schemes. The technical sessions included alloy metallurgy and properties, environmental effects and properties, deformation behavior and properties, relation between corrosion and mechanical properties, coatings, intermetallics, ceramics, and materials for waste incineration. Seventy one papers have been processed separately for inclusion on the data base

Induction of Apoptosis and expression of Apoptosis-related gene products in response to radiation in murine tumors

International Nuclear Information System (INIS)

Seong, J. S.

1997-01-01

To analyze the involvement of apoptosis regulatory genes p53, p21 waf1/cip1 , bax and bcl-2 in induction of apoptosis by radiation in murine tumors. The radiation-sensitive ovarian carcinoma OCa-I and the radiation-resistant hepatocarcinoma HCa-I were used. Tumors, 8mm in diameter, were irradiated with 25Gy and at various times after irradiation, ranging from 1 to 48 h, were analyzed histologically for apoptosis and by western blot for alterations in the expression of these genes. The p53 status of the tumors were determined by the polymerase chain reaction-single strand conformation polymorphism assay. Both tumors were positive for wild-type p53. Radiation induced apoptosis in OCa-I but not in HCa-I. Apoptosis developed rapidly, peaked at 2 h after irradiation and returned to almost the background level at 48 h. In OCa-I radiation upregulated the expression of p53, p21 waf1/cip1 , and the bcl-2/bax ratio was decreased. In HCa-I radiation increased the expression of both p53 and p21 waf1/cip1 , although the increase of the latter was small. The bcl-2/bax ratio was greatly increased. In general the observed changes occurred within a few hours after irradiation, and either preceded or coincided with development of apoptosis. The development of apoptosis required upregulation of both p53 and p21 waf1/cip1 as well as a decrease in bcl-2/bax ratio. In contrast, an increase in bcl-2/bax ratio prevented apoptosis in the presence of upregulated p53 and p21 waf1/cip1 . These findings identified the involvement of multiple oncogenes in apoptosis regulation in vivo and demonstrate the complexity that may be associated with the use of a single oncogene assessment for predicting the outcome of cancer therapy with cytotoxic agents. (author)

Induction of Apoptosis and expression of Apoptosis-related gene products in response to radiation in murine tumors

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Seong, J S [Yonsei Univ., Seoul (Korea, Republic of). Coll. of Medicine; Hunter, N R; Milas, L [Texas Univ., Houston, TX (United States)

1997-09-01

To analyze the involvement of apoptosis regulatory genes p53, p21{sup waf1/cip1}, bax and bcl-2 in induction of apoptosis by radiation in murine tumors. The radiation-sensitive ovarian carcinoma OCa-I and the radiation-resistant hepatocarcinoma HCa-I were used. Tumors, 8mm in diameter, were irradiated with 25Gy and at various times after irradiation, ranging from 1 to 48 h, were analyzed histologically for apoptosis and by western blot for alterations in the expression of these genes. The p53 status of the tumors were determined by the polymerase chain reaction-single strand conformation polymorphism assay. Both tumors were positive for wild-type p53. Radiation induced apoptosis in OCa-I but not in HCa-I. Apoptosis developed rapidly, peaked at 2 h after irradiation and returned to almost the background level at 48 h. In OCa-I radiation upregulated the expression of p53, p21{sup waf1/cip1}, and the bcl-2/bax ratio was decreased. In HCa-I radiation increased the expression of both p53 and p21{sup waf1/cip1}, although the increase of the latter was small. The bcl-2/bax ratio was greatly increased. In general the observed changes occurred within a few hours after irradiation, and either preceded or coincided with development of apoptosis. The development of apoptosis required upregulation of both p53 and p21{sup waf1/cip1} as well as a decrease in bcl-2/bax ratio. In contrast, an increase in bcl-2/bax ratio prevented apoptosis in the presence of upregulated p53 and p21{sup waf1/cip1}. These findings identified the involvement of multiple oncogenes in apoptosis regulation in vivo and demonstrate the complexity that may be associated with the use of a single oncogene assessment for predicting the outcome of cancer therapy with cytotoxic agents. (author).

Prevalence of quinolone resistance genes, copper resistance genes, and the bacterial communities in a soil-ryegrass system co-polluted with copper and ciprofloxacin.

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Tuo, Xiaxia; Gu, Jie; Wang, Xiaojuan; Sun, YiXin; Duan, Manli; Sun, Wei; Yin, Yanan; Guo, Aiyun; Zhang, Li

2018-04-01

The presence of high concentrations of residual antibiotics and antibiotic resistance genes (ARGs) in soil may pose potential health and environmental risks. This study investigated the prevalence of plasmid-mediated quinolone resistance (PMQR) genes, copper resistance genes (CRGs), and the bacterial communities in a soil-ryegrass pot system co-polluted with copper and ciprofloxacin (CIP; 0, 20, or 80 mg kg -1 dry soil). Compared with the samples on day 0, the total relative abundances of the PMQR genes and mobile genetic elements (MGEs) were reduced significantly by 80-89% in the ryegrass and soil by the cutting stage (after 75 days). The abundances of PMQR genes and MGEs were reduced by 63-81% in soil treated with 20 mg kg -1 CIP compared with the other treatments, but the abundances of CRGs increased by 18-42%. The presence of 80 mg kg -1 CIP affected the microbial community structure in the soil by increasing the abundances of Acidobacteria and Thaumarchaeota, but decreasing those of Firmicutes. Redundancy analysis indicated that the pH and microbial composition were the main factors that affected the variations in PMQR genes, MGEs, and CRGs, where they could explain 42.2% and 33.3% of the variation, respectively. Furthermore, intI2 may play an important role in the transfer of ARGs. We found that 80 mg kg -1 CIP could increase the abundances of ARGs and CRGs in a soil-ryegrass pot system. Copyright © 2018 Elsevier Ltd. All rights reserved.

A horizontally gene transferred copper resistance locus confers hyper‐resistance to antibacterial copper toxicity and enables survival of community acquired methicillin resistant Staphylococcus aureus USA300 in macrophages

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Purves, Joanne; Thomas, Jamie; Riboldi, Gustavo P.; Zapotoczna, Marta; Tarrant, Emma; Andrew, Peter W.; Londoño, Alejandra; Planet, Paul J.; Geoghegan, Joan A.; Waldron, Kevin J.

2018-01-01

Summary Excess copper is highly toxic and forms part of the host innate immune system's antibacterial arsenal, accumulating at sites of infection and acting within macrophages to kill engulfed pathogens. We show for the first time that a novel, horizontally gene transferred copper resistance locus (copXL), uniquely associated with the SCCmec elements of the highly virulent, epidemic, community acquired methicillin resistant Staphylococcus aureus (CA‐MRSA) USA300, confers copper hyper‐resistance. These genes are additional to existing core genome copper resistance mechanisms, and are not found in typical S. aureus lineages, but are increasingly identified in emerging pathogenic isolates. Our data show that CopX, a putative P1B‐3‐ATPase efflux transporter, and CopL, a novel lipoprotein, confer copper hyper‐resistance compared to typical S. aureus strains. The copXL genes form an operon that is tightly repressed in low copper environments by the copper regulator CsoR. Significantly, CopX and CopL are important for S. aureus USA300 intracellular survival within macrophages. Therefore, the emergence of new S. aureus clones with the copXL locus has significant implications for public health because these genes confer increased resistance to antibacterial copper toxicity, enhancing bacterial fitness by altering S. aureus interaction with innate immunity. PMID:29521441

Loss of p53 induces cell proliferation via Ras-independent activation of the Raf/Mek/Erk signaling pathway

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Drosten, Matthias; Sum, Eleanor Y. M.; Lechuga, Carmen G.; Simón-Carrasco, Lucía; Jacob, Harrys K. C.; García-Medina, Raquel; Huang, Sidong; Beijersbergen, Roderick L.; Bernards, Rene; Barbacid, Mariano

2014-01-01

The Ras family of small GTPases constitutes a central node in the transmission of mitogenic stimuli to the cell cycle machinery. The ultimate receptor of these mitogenic signals is the retinoblastoma (Rb) family of pocket proteins, whose inactivation is a required step to license cell proliferation. However, little is known regarding the molecular events that connect Ras signaling with the cell cycle. Here, we provide genetic evidence to illustrate that the p53/p21 Cdk-interacting protein 1 (Cip1)/Rb axis is an essential component of the Ras signaling pathway. Indeed, knockdown of p53, p21Cip1, or Rb restores proliferative properties in cells arrested by ablation of the three Ras loci, H-, N- and K-Ras. Ras signaling selectively inactivates p53-mediated induction of p21Cip1 expression by inhibiting acetylation of specific lysine residues in the p53 DNA binding domain. Proliferation of cells lacking both Ras proteins and p53 can be prevented by reexpression of the human p53 ortholog, provided that it retains an active DNA binding domain and an intact lysine residue at position 164. These results unveil a previously unidentified role for p53 in preventing cell proliferation under unfavorable mitogenic conditions. Moreover, we provide evidence that cells lacking Ras and p53 proteins owe their proliferative properties to the unexpected retroactivation of the Raf/Mek/Erk cascade by a Ras-independent mechanism. PMID:25288756

Marker-Assisted Selection of Xa21 Conferring Resistance to Bacterial Leaf Blight in indica Rice Cultivar LT2

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Hue Thi Nguyen

2018-01-01

Full Text Available Bacterial leaf blight of rice (BLB, caused by Xanthomonas oryzae pv. oryzae, is one of the most destructive diseases in Asian rice fields. A high-quality rice variety, LT2, was used as the recipient parent. IRBB21, which carries the Xa21 gene, was used as the donor parent. The resistance gene Xa21 was introduced into LT2 by marker-assisted backcrossing. Three Xoo races were used to inoculate the improved lines following the clipping method. Eleven BC3F3 lines carrying Xa21 were obtained based on molecular markers and agronomic performance. The 11 lines were then inoculated with the three Xoo races. All the 11 improved lines showed better resistance to BLB than the recipient parent LT2. Based on the level of resistance to BLB and their agronomic performance, five lines (BC3F3 5.1.5.1, BC3F3 5.1.5.12, BC3F3 8.5.6.44, BC3F3 9.5.4.1 and BC3F3 9.5.4.23 were selected as the most promising for commercial release. These improved lines could contribute to rice production in terms of food security.

An unusual methylene aziridine refined in P2(1)/c and the nonstandard setting P2(1)/n.

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Feast, George C; Haestier, James; Page, Lee W; Robertson, Jeremy; Thompson, Amber L; Watkin, David J

2009-12-01

The unusual methylene aziridine 6-tert-butyl-3-oxa-2-thia-1-azabicyclo[5.1.0]oct-6-ene 2,2-dioxide, C(9)H(15)NO(3)S, was found to crystallize with two molecules in the asymmetric unit. The structure was solved in both the approximately orthogonal and the oblique settings of space group No. 14, viz. P2(1)/n and P2(1)/c, respectively. A comparison of these results clearly displayed an increase in the correlation between coordinates in the ac plane for the oblique cell. The increase in the corresponding covariances makes a significant contribution to the standard uncertainties of derived parameters, e.g. bond lengths. Since there is yet no CIF definition for the full variance-covariance matrix, there are clear advantages to reporting the structure in the nonstandard space-group setting.

PKC-alpha modulation by miR-483-3p in platinum-resistant ovarian carcinoma cells

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Arrighetti, Noemi, E-mail: Noemi.Arrighetti@istitutotumori.mi.it [Molecular Pharmacology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, via Amadeo 42, Milan 20133 (Italy); Cossa, Giacomo, E-mail: Gia.Cossa@gmail.com [Molecular Pharmacology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, via Amadeo 42, Milan 20133 (Italy); De Cecco, Loris, E-mail: Loris.Dececco@istitutotumori.mi.it [Functional Genomics and Bioinformatics, Fondazione IRCCS Istituto Nazionale dei Tumori, via Amadeo 42, Milan 20133 (Italy); Stucchi, Simone, E-mail: Simone.Stucchi@istitutotumori.mi.it [Molecular Pharmacology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, via Amadeo 42, Milan 20133 (Italy); Carenini, Nives, E-mail: Nives.Carenini@istitutotumori.mi.it [Molecular Pharmacology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, via Amadeo 42, Milan 20133 (Italy); Corna, Elisabetta, E-mail: Elisabetta.Corna@istitutotumori.mi.it [Molecular Pharmacology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, via Amadeo 42, Milan 20133 (Italy); Gandellini, Paolo, E-mail: Paolo.Gandellini@istitutotumori.mi.it [Molecular Pharmacology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, via Amadeo 42, Milan 20133 (Italy); Zaffaroni, Nadia, E-mail: Nadia.Zaffaroni@istitutotumori.mi.it [Molecular Pharmacology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, via Amadeo 42, Milan 20133 (Italy); Perego, Paola, E-mail: paola.perego@istitutotumori.mi.it [Molecular Pharmacology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, via Amadeo 42, Milan 20133 (Italy); Gatti, Laura, E-mail: Laura.Gatti@istitutotumori.mi.it [Molecular Pharmacology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, via Amadeo 42, Milan 20133 (Italy)

2016-11-01

The occurrence of drug resistance limits the efficacy of platinum compounds in the cure of ovarian carcinoma. Since microRNAs (miRNAs) may contribute to this phenomenon by regulating different aspects of tumor cell response, the aim of this study was to exploit the analysis of expression of miRNAs in platinum sensitive/resistant cells in an attempt to identify potential regulators of drug response. MiR-483-3p, which may participate in apoptosis and cell proliferation regulation, was found up-regulated in 4 platinum resistant variants, particularly in the IGROV-1/Pt1 subline, versus parental cells. Transfection of a synthetic precursor of miR-483-3p in IGROV-1 parental cells elicited a marked up-regulation of the miRNA levels. Growth-inhibition and colony-forming assays indicated that miR-483-3p over-expression reduced cell growth and conferred mild levels of cisplatin resistance in IGROV-1 cells, by interference with their proliferative potential. Predicted targets of miR-483-3p included PRKCA (encoding PKC-alpha), previously reported to be associated to platinum-resistance in ovarian carcinoma. We found that miR-483-3p directly targeted PRKCA in IGROV-1 cells. In keeping with this finding, cisplatin sensitivity of IGROV-1 cells decreased upon molecular/pharmacological inhibition of PKC-alpha. Overall, our results suggest that overexpression of miR-483-3p by ovarian carcinoma platinum-resistant cells may interfere with their proliferation, thus protecting them from DNA damage induced by platinum compounds and ultimately representing a drug-resistance mechanism. The impairment of cell growth may account for low levels of drug resistance that could be relevant in the clinical setting. - Highlights: • miR-483-3p is up-regulated in ovarian carcinoma cells resistant to platinum drugs. • Ectopic expression of miR-483-3p in IGROV-1 confers mild levels of Pt-resistance. • Overexpression of miR-483-3p down-regulates PRKCA levels in ovarian carcinoma cells. • miR 483

Expression of artificial microRNAs in transgenic Arabidopsis thaliana confers virus resistance.

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Niu, Qi-Wen; Lin, Shih-Shun; Reyes, Jose Luis; Chen, Kuan-Chun; Wu, Hui-Wen; Yeh, Shyi-Dong; Chua, Nam-Hai

2006-11-01

Plant microRNAs (miRNAs) regulate the abundance of target mRNAs by guiding their cleavage at the sequence complementary region. We have modified an Arabidopsis thaliana miR159 precursor to express artificial miRNAs (amiRNAs) targeting viral mRNA sequences encoding two gene silencing suppressors, P69 of turnip yellow mosaic virus (TYMV) and HC-Pro of turnip mosaic virus (TuMV). Production of these amiRNAs requires A. thaliana DICER-like protein 1. Transgenic A. thaliana plants expressing amiR-P69(159) and amiR-HC-Pro(159) are specifically resistant to TYMV and TuMV, respectively. Expression of amiR-TuCP(159) targeting TuMV coat protein sequences also confers specific TuMV resistance. However, transgenic plants that express both amiR-P69(159) and amiR-HC-Pro(159) from a dimeric pre-amiR-P69(159)/amiR-HC-Pro(159) transgene are resistant to both viruses. The virus resistance trait is displayed at the cell level and is hereditable. More important, the resistance trait is maintained at 15 degrees C, a temperature that compromises small interfering RNA-mediated gene silencing. The amiRNA-mediated approach should have broad applicability for engineering multiple virus resistance in crop plants.

Associations between resistance phenotype and gene expression in response to serial exposure to oxacillin and ciprofloxacin in Staphylococcus aureus.

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Uddin, M J; Ahn, J

2017-12-01

This study was designed to delineate the relationship between resistance phenotypes and gene expression in wild-type (SA WT ), oxacillin-induced (SA OXA ), ciprofloxacin-induced (SA CIP ) and clinically acquired antibiotic-resistant Staphylococcus aureus (SA CA ) exposed to oxacillin (β-lactam) and ciprofloxacin (fluoroquinolone). The phenotypic response and gene expression were varied with the antibiotic exposure. SA WT was highly resistant to oxacillin (MIC = 8 μg ml -1 ) after serial exposure to oxacillin, while the oxacillin susceptibility was not changed in SA WT when exposed to ciprofloxacin (MIC = 0·25 μg ml -1 ). The clinical isolate, SA CA , was highly resistant to all classes of antibiotics used in this study. The increased resistance of SA OXA and SA CIP to penicillinase-labile penicillins was attributed to the production of β-lactamase, which is in good agreement with the overexpression of blaZ (>2-fold). The overexpression of efflux pump-related genes (norA, norB, norC, mdeA, mepR, mgrA and lmrS) was associated with the increased resistance of SA CIP and SA CA to aminoglycosides and quinolones. This study confirmed that the linkage between resistance phenotypes and molecular genotypes highly varied depending on intrinsic resistance profile, response to antibiotic exposure and genes conferring resistance. This study provides useful information for understanding the mechanisms of methicillin resistance in S. aureus in association with phenotypic and genotypic resistance determinants. The improvement in current standards is essential to accurately detect methicillin-resistant Staphylococcus aureus in consideration of various resistance phenotypes and genotypes. The varied and distinctive expression patterns of antibiotic resistance-related genes were observed in S. aureus exposed to oxacillin and ciprofloxacin. It is worth noting the relationship between resistance phenotype and resistance genotype in terms of MIC values and expression of

Reduction of MLH1 and PMS2 confers temozolomide resistance and is associated with recurrence of glioblastoma.

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Shinsato, Yoshinari; Furukawa, Tatsuhiko; Yunoue, Shunji; Yonezawa, Hajime; Minami, Kentarou; Nishizawa, Yukihiko; Ikeda, Ryuji; Kawahara, Kohichi; Yamamoto, Masatatsu; Hirano, Hirofumi; Tokimura, Hiroshi; Arita, Kazunori

2013-12-01

Although there is a relationship between DNA repair deficiency and temozolomide (TMZ) resistance in glioblastoma (GBM), it remains unclear which molecule is associated with GBM recurrence. We isolated three TMZ-resistant human GBM cell lines and examined the expression of O6-methylguanine-DNA methyltransferase (MGMT) and mismatch repair (MMR) components. We used immunohistochemical analysis to compare MutL homolog 1 (MLH1), postmeiotic segregation increased 2 (PMS2) and MGMT expression in primary and recurrent GBM specimens obtained from GBM patients during TMZ treatment. We found a reduction in MLH1 expression and a subsequent reduction in PMS2 protein levels in TMZ-resistant cells. Furthermore, MLH1 or PMS2 knockdown confered TMZ resistance. In recurrent GBM tumours, the expression of MLH1 and PMS2 was reduced when compared to primary tumours.

N348I in the connection domain of HIV-1 reverse transcriptase confers zidovudine and nevirapine resistance.

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Soo-Huey Yap

2007-12-01

Full Text Available The catalytically active 66-kDa subunit of the human immunodeficiency virus type 1 (HIV-1 reverse transcriptase (RT consists of DNA polymerase, connection, and ribonuclease H (RNase H domains. Almost all known RT inhibitor resistance mutations identified to date map to the polymerase domain of the enzyme. However, the connection and RNase H domains are not routinely analysed in clinical samples and none of the genotyping assays available for patient management sequence the entire RT coding region. The British Columbia Centre for Excellence in HIV/AIDS (the Centre genotypes clinical isolates up to codon 400 in RT, and our retrospective statistical analyses of the Centre's database have identified an N348I mutation in the RT connection domain in treatment-experienced individuals. The objective of this multidisciplinary study was to establish the in vivo relevance of this mutation and its role in drug resistance.The prevalence of N348I in clinical isolates, the time taken for it to emerge under selective drug pressure, and its association with changes in viral load, specific drug treatment, and known drug resistance mutations was analysed from genotypes, viral loads, and treatment histories from the Centre's database. N348I increased in prevalence from below 1% in 368 treatment-naïve individuals to 12.1% in 1,009 treatment-experienced patients (p = 7.7 x 10(-12. N348I appeared early in therapy and was highly associated with thymidine analogue mutations (TAMs M41L and T215Y/F (p < 0.001, the lamivudine resistance mutations M184V/I (p < 0.001, and non-nucleoside RTI (NNRTI resistance mutations K103N and Y181C/I (p < 0.001. The association with TAMs and NNRTI resistance mutations was consistent with the selection of N348I in patients treated with regimens that included both zidovudine and nevirapine (odds ratio 2.62, 95% confidence interval 1.43-4.81. The appearance of N348I was associated with a significant increase in viral load (p < 0.001, which

The cold-induced defensin TAD1 confers resistance against snow mold and Fusarium head blight in transgenic wheat.

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Sasaki, Kentaro; Kuwabara, Chikako; Umeki, Natsuki; Fujioka, Mari; Saburi, Wataru; Matsui, Hirokazu; Abe, Fumitaka; Imai, Ryozo

2016-06-20

TAD1 (Triticum aestivum defensin 1) is induced during cold acclimation in winter wheat and encodes a plant defensin with antimicrobial activity. In this study, we demonstrated that recombinant TAD1 protein inhibits hyphal growth of the snow mold fungus, Typhula ishikariensis in vitro. Transgenic wheat plants overexpressing TAD1 were created and tested for resistance against T. ishikariensis. Leaf inoculation assays revealed that overexpression of TAD1 confers resistance against the snow mold. In addition, the TAD1-overexpressors showed resistance against Fusarium graminearum, which causes Fusarium head blight, a devastating disease in wheat and barley. These results indicate that TAD1 is a candidate gene to improve resistance against multiple fungal diseases in cereal crops. Copyright © 2016 Elsevier B.V. All rights reserved.

ERK mutations confer resistance to mitogen-activated protein kinase pathway inhibitors.

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Goetz, Eva M; Ghandi, Mahmoud; Treacy, Daniel J; Wagle, Nikhil; Garraway, Levi A

2014-12-01

The use of targeted therapeutics directed against BRAF(V600)-mutant metastatic melanoma improves progression-free survival in many patients; however, acquired drug resistance remains a major medical challenge. By far, the most common clinical resistance mechanism involves reactivation of the MAPK (RAF/MEK/ERK) pathway by a variety of mechanisms. Thus, targeting ERK itself has emerged as an attractive therapeutic concept, and several ERK inhibitors have entered clinical trials. We sought to preemptively determine mutations in ERK1/2 that confer resistance to either ERK inhibitors or combined RAF/MEK inhibition in BRAF(V600)-mutant melanoma. Using a random mutagenesis screen, we identified multiple point mutations in ERK1 (MAPK3) and ERK2 (MAPK1) that could confer resistance to ERK or RAF/MEK inhibitors. ERK inhibitor-resistant alleles were sensitive to RAF/MEK inhibitors and vice versa, suggesting that the future development of alternating RAF/MEK and ERK inhibitor regimens might help circumvent resistance to these agents. ©2014 American Association for Cancer Research.

Development of a Fish Cell Biosensor System for Genotoxicity Detection Based on DNA Damage-Induced Trans-Activation of p21 Gene Expression

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Huarong Guo

2012-09-01

Full Text Available p21CIP1/WAF1 is a p53-target gene in response to cellular DNA damage. Here we report the development of a fish cell biosensor system for high throughput genotoxicity detection of new drugs, by stably integrating two reporter plasmids of pGL3-p21-luc (human p21 promoter linked to firefly luciferase and pRL-CMV-luc (CMV promoter linked to Renilla luciferase into marine flatfish flounder gill (FG cells, referred to as p21FGLuc. Initial validation of this genotoxicity biosensor system showed that p21FGLuc cells had a wild-type p53 signaling pathway and responded positively to the challenge of both directly acting genotoxic agents (bleomycin and mitomycin C and indirectly acting genotoxic agents (cyclophosphamide with metabolic activation, but negatively to cyclophosphamide without metabolic activation and the non-genotoxic agents ethanol and D-mannitol, thus confirming a high specificity and sensitivity, fast and stable response to genotoxic agents for this easily maintained fish cell biosensor system. This system was especially useful in the genotoxicity detection of Di(2-ethylhexyl phthalate (DEHP, a rodent carcinogen, but negatively reported in most non-mammalian in vitro mutation assays, by providing a strong indication of genotoxicity for DEHP. A limitation for this biosensor system was that it might give false positive results in response to sodium butyrate and any other agents, which can trans-activate the p21 gene in a p53-independent manner.

cipC is important for Aspergillus fumigatus virulence.

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Canela, Heliara Maria Spina; Takami, Luciano Akira; da Silva Ferreira, Márcia Eliana

2017-02-01

Aspergillus fumigatus is the main causative agent of invasive aspergillosis, a disease that affects immunocompromised patients and has a high mortality rate. We previously observed that the transcription of a cipC-like gene was increased when A. fumigatus encountered an increased CO 2 concentration, as occurs during the infection process. CipC is a protein of unknown function that might be associated with fungal pathogenicity. In this study, the cipC gene was disrupted in A. fumigatus to evaluate its importance for fungal pathogenicity. The gene was replaced, and the germination, growth phenotype, stress responses, and virulence of the resultant mutant were assessed. Although cipC was not essential, its deletion attenuated A. fumigatus virulence in a low-dose murine infection model, suggesting the involvement of the cipC gene in the virulence of this fungus. This study is the first to disrupt the cipC gene in A. fumigatus. © 2017 APMIS. Published by John Wiley & Sons Ltd.

Identification of a rice gene (Bph 1) conferring resistance to brown planthopper (Nilaparvata lugens Stal) using STS markers.

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Kim, Suk-Man; Sohn, Jae-Keun

2005-08-31

This study was carried out to identify a high-resolution marker for a gene conferring resistance to brown planthopper (BPH) biotype 1, using japonica type resistant lines. Bulked segregant analyses were conducted using 520 RAPD primers to identify RAPD fragments linked to the BPH resistance gene. Eleven RAPDs were shown to be polymorphic amplicons between resistant and susceptible progeny. One of these primers, OPE 18, which amplified a 923 bp band tightly linked to resistance, was converted into a sequence-tagged-site (STS) marker. The STS marker, BpE18-3, was easily detectable as a dominant band with tight linkage (3.9cM) to Bph1. It promises to be useful as a marker for assisted selection of resistant progeny in backcross breeding programs to introgress the resistance gene into elite japonica cultivars.

Multiple origins of resistance-conferring mutations in Plasmodium vivax dihydrofolate reductase

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O'Neil Michael T

2008-04-01

Full Text Available Abstract Background In order to maximize the useful therapeutic life of antimalarial drugs, it is crucial to understand the mechanisms by which parasites resistant to antimalarial drugs are selected and spread in natural populations. Recent work has demonstrated that pyrimethamine-resistance conferring mutations in Plasmodium falciparum dihydrofolate reductase (dhfr have arisen rarely de novo, but spread widely in Asia and Africa. The origin and spread of mutations in Plasmodium vivax dhfr were assessed by constructing haplotypes based on sequencing dhfr and its flanking regions. Methods The P. vivax dhfr coding region, 792 bp upstream and 683 bp downstream were amplified and sequenced from 137 contemporary patient isolates from Colombia, India, Indonesia, Papua New Guinea, Sri Lanka, Thailand, and Vanuatu. A repeat motif located 2.6 kb upstream of dhfr was also sequenced from 75 of 137 patient isolates, and mutational relationships among the haplotypes were visualized using the programme Network. Results Synonymous and non-synonymous single nucleotide polymorphisms (SNPs within the dhfr coding region were identified, as was the well-documented in-frame insertion/deletion (indel. SNPs were also identified upstream and downstream of dhfr, with an indel and a highly polymorphic repeat region identified upstream of dhfr. The regions flanking dhfr were highly variable. The double mutant (58R/117N dhfr allele has evolved from several origins, because the 58R is encoded by at least 3 different codons. The triple (58R/61M/117T and quadruple (57L/61M/117T/173F, 57I/58R/61M/117T and 57L/58R/61M/117T mutant alleles had at least three independent origins in Thailand, Indonesia, and Papua New Guinea/Vanuatu. Conclusion It was found that the P. vivax dhfr coding region and its flanking intergenic regions are highly polymorphic and that mutations in P. vivax dhfr that confer antifolate resistance have arisen several times in the Asian region. This contrasts

Prevalence of p21 immunohistochemical expression in esophageal adenocarcinoma Prevalência da expressão imunoistoquímica da proteína p21 em adenocarcinoma do esôfago

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Maitê de Mello Villwock

2006-09-01

Full Text Available BACKGROUND: In western societies, the prevalence of adenocarcinoma of the gastroesophageal junction has increased in recent years. It is commonly accepted today that esophageal adenocarcinoma develops from a premalignant lesion: Barrett's esophagus. This type of carcinoma is hardly diagnosed at early stages, which results in significant mortality. Molecular biology studies have shown that most malignant tumors originate from the interaction between inherited characteristics and external factors, which may cause genetic changes that interfere with the control over the differentiation and growth of cells in susceptible individuals. p21 (WAF1/CIP1 has a key role in the regulation of the cell cycle, and its immunohistochemical expression has been investigated in several tumors, showing that it influences the prognosis of various neoplasms. AIM: To check the prevalence of p21 protein expression in patients with esophageal adenocarcinoma diagnosed in the last 5 years by the Group for Surgeries of the Esophagus and Stomach of "Hospital de Clínicas de Porto Alegre", RS, Brazil. METHODS: The study population consisted of 42 patients with esophageal adenocarcinoma diagnosed by the Group for Surgeries of the Esophagus and Stomach between January 1998 and December 2002. The expression of p21 protein was determined by immunohistochemistry using primary antibody, p21, clone SX118, code M7202 (Dako, and assessed according to the immunoreactive scoring system. RESULTS: Of 42 analyzed patients, 83.3% were male and older than 40 years. Among these, 56.2% were submitted to curative resection: total gastrectomy and transhiatal esophagogastrectomy. The remaining patients were submitted to palliative surgery or did not undergo any surgical treatment. Only five patients received adjuvant chemotherapy and radiation therapy, either alone or combined. Advanced disease (stages III and IV was detected in 78.6% of the patients. Only nine patients were positive for p21

Role of Pex21p for Piggyback Import of Gpd1p and Pnc1p into Peroxisomes of Saccharomyces cerevisiae*

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Effelsberg, Daniel; Cruz-Zaragoza, Luis Daniel; Tonillo, Jason; Schliebs, Wolfgang; Erdmann, Ralf

2015-01-01

Proteins designated for peroxisomal protein import harbor one of two common peroxisomal targeting signals (PTS). In the yeast Saccharomyces cerevisiae, the oleate-induced PTS2-dependent import of the thiolase Fox3p into peroxisomes is conducted by the soluble import receptor Pex7p in cooperation with the auxiliary Pex18p, one of two supposedly redundant PTS2 co-receptors. Here, we report on a novel function for the co-receptor Pex21p, which cannot be fulfilled by Pex18p. The data establish Pex21p as a general co-receptor in PTS2-dependent protein import, whereas Pex18p is especially important for oleate-induced import of PTS2 proteins. The glycerol-producing PTS2 protein glycerol-3-phosphate dehydrogenase Gpd1p shows a tripartite localization in peroxisomes, in the cytosol, and in the nucleus under osmotic stress conditions. We show the following: (i) Pex21p is required for peroxisomal import of Gpd1p as well as a key enzyme of the NAD+ salvage pathway, Pnc1p; (ii) Pnc1p, a nicotinamidase without functional PTS2, is co-imported into peroxisomes by piggyback transport via Gpd1p. Moreover, the specific transport of these two enzymes into peroxisomes suggests a novel regulatory role for peroxisomes under various stress conditions. PMID:26276932

Study of thermal-hydraulic analyses with CIP method

International Nuclear Information System (INIS)

Doi, Yoshihiro

1996-09-01

New type of numerical scheme CIP has been proposed for solving hyperbolic type equations and the CIP is focused on as a less numerical diffusive scheme. C-CUP method with the CIP scheme is adopted to numerical simulations that treat compressible and incompressible fluids, phase change phenomena and Mixture fluids. To evaluate applicabilities of the CIP scheme and C-CUP method for thermal hydraulic analyses related to Fast Breeder Reactors (FBRs), the scheme and the method were reviewed. Feature of the CIP scheme and procedure of the C-CUP method were presented. The CIP scheme is used to solve linear hyperbolic type equations for advection term in basic equations of fluids. Key issues of the scheme is that profile between grid points is described to solve the equation by cubic polynomial and spatial derivatives of the polynomial. The scheme can capture steep change of solution and suppress numerical error. In the C-CUP method, the basic equations of fluids are divided into advection terms and the other terms. The advection terms is solved with CIP scheme and the other terms is solved with difference method. The C-CUP method is robust for numerical instability, but mass of fluid will be in unfair preservation with nonconservative equations for fluids. Numerical analyses with the CIP scheme and the C-CUP method has been performed for phase change, mixture and moving object. These analyses are depend on characteristics of that the scheme and the method are robust for steep change of density and useful for interface tracking. (author)

Role of Pex21p for Piggyback Import of Gpd1p and Pnc1p into Peroxisomes of Saccharomyces cerevisiae.

Science.gov (United States)

Effelsberg, Daniel; Cruz-Zaragoza, Luis Daniel; Tonillo, Jason; Schliebs, Wolfgang; Erdmann, Ralf

2015-10-16

Proteins designated for peroxisomal protein import harbor one of two common peroxisomal targeting signals (PTS). In the yeast Saccharomyces cerevisiae, the oleate-induced PTS2-dependent import of the thiolase Fox3p into peroxisomes is conducted by the soluble import receptor Pex7p in cooperation with the auxiliary Pex18p, one of two supposedly redundant PTS2 co-receptors. Here, we report on a novel function for the co-receptor Pex21p, which cannot be fulfilled by Pex18p. The data establish Pex21p as a general co-receptor in PTS2-dependent protein import, whereas Pex18p is especially important for oleate-induced import of PTS2 proteins. The glycerol-producing PTS2 protein glycerol-3-phosphate dehydrogenase Gpd1p shows a tripartite localization in peroxisomes, in the cytosol, and in the nucleus under osmotic stress conditions. We show the following: (i) Pex21p is required for peroxisomal import of Gpd1p as well as a key enzyme of the NAD(+) salvage pathway, Pnc1p; (ii) Pnc1p, a nicotinamidase without functional PTS2, is co-imported into peroxisomes by piggyback transport via Gpd1p. Moreover, the specific transport of these two enzymes into peroxisomes suggests a novel regulatory role for peroxisomes under various stress conditions. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Modifications in cell cycle kinetics and in expression of G1 phase-regulating proteins in human amniotic cells after exposure to electromagnetic fields and ionizing radiation.

Science.gov (United States)

Lange, S; Viergutz, T; Simkó, M

2004-10-01

Low-frequency electromagnetic fields are suspected of being involved in carcinogenesis, particularly in processes that could be related to cancer promotion. Because development of cancer is associated with deregulated cell growth and we previously observed a magnetic field-induced decrease in DNA synthesis [Lange et al. (2002) Alterations in the cell cycle and in the protein level of cyclin D1p, 21CIP1, and p16INK4a after exposure to 50 HZ. MF in human cells. Radiat. Environ. Biophys.41, 131], this study aims to document the influence of 50 Hz, 1 mT magnetic fields (MF), with or without initial gamma-ionizing radiation (IR), on the following cell proliferation-relevant parameters in human amniotic fluid cells (AFC): cell cycle distribution, expression of the G1 phase-regulating proteins Cdk4, cyclin D1, p21CIP1 and p16INK4a, and Cdk4 activity. While IR induced a G1 delay and a dose-dependent G2 arrest, no discernible changes in cell cycle kinetics were observed due to MF exposure. However, a significant decrease in the protein expression of cyclin D1 and an increase in p21CIP1- and p16INK4a-expression could be detected after exposure to MF alone. IR-exposure caused an augmentation of p21CIP1- and p16INK4a- levels as well, but did not alter cyclin D1 expression. A slight diminution of Cdk4 activity was noticed after MF exposure only, indicating that Cdk4 appears not to act as a mediator of MF- or IR-induced changes in the cell cycle of AFC cells. Co-exposure to MF/IR affected neither cell cycle distribution nor protein expression or kinase activity additionally or synergistically, and therefore MF seems not to modify the mutagenic potency of IR.

Reaching consensus on drug resistance conferring mutations (Part 1

Directory of Open Access Journals (Sweden)

Daniela M Cirillo

2016-01-01

A user-friendly interface designed for nonexpert or expert operability.A standardized and validated analysis pipeline for variant analyses of M. tuberculosis next-generation sequencing (NGS data.Access to data beyond the published literature with dynamic and iterative updates of new data generated by global surveillance and clinical trials.A well-developed legal structure to ensure intellectual property rights and data ownership remain with contributors.A structured data-sharing architecture to restrict access to sensitive or unpublished data sets.Metadata standardization using CDISC: supports global, platform-independent data standards that enable information system interoperability.An emphasis on data quality and rigorous, expert curation with multiple quality control checks for whole-genome sequencing and other metadata.Validation of NGS analysis output by an expert committee with grading of resistance conferring mutations based on rigorous statistical standards.Regulatory-compliant analysis pipeline and database architecture. Successful execution of such an extensive database platform requires substantial collaboration from scientists investigating the genetic basis for drug resistance worldwide, and from developers with expertise in database design and implementation.

Food supply confers calcifiers resistance to ocean acidification

KAUST Repository

Ramajo, Laura; Pé rez-Leó n, Elia; Hendriks, Iris E.; Marbà , Nú ria; Krause-Jensen, Dorte; Sejr, Mikael K.; Blicher, Martin E.; Lagos, Nelson A.; Olsen, Ylva S.; Duarte, Carlos M.

2016-01-01

Invasion of ocean surface waters by anthropogenic CO2 emitted to the atmosphere is expected to reduce surface seawater pH to 7.8 by the end of this century compromising marine calcifiers. A broad range of biological and mineralogical mechanisms allow marine calcifiers to cope with ocean acidification, however these mechanisms are energetically demanding which affect other biological processes (trade-offs) with important implications for the resilience of the organisms against stressful conditions. Hence, food availability may play a critical role in determining the resistance of calcifiers to OA. Here we show, based on a meta-analysis of existing experimental results assessing the role of food supply in the response of organisms to OA, that food supply consistently confers calcifiers resistance to ocean acidification.

Food supply confers calcifiers resistance to ocean acidification

KAUST Repository

Ramajo, Laura

2016-01-18

Invasion of ocean surface waters by anthropogenic CO2 emitted to the atmosphere is expected to reduce surface seawater pH to 7.8 by the end of this century compromising marine calcifiers. A broad range of biological and mineralogical mechanisms allow marine calcifiers to cope with ocean acidification, however these mechanisms are energetically demanding which affect other biological processes (trade-offs) with important implications for the resilience of the organisms against stressful conditions. Hence, food availability may play a critical role in determining the resistance of calcifiers to OA. Here we show, based on a meta-analysis of existing experimental results assessing the role of food supply in the response of organisms to OA, that food supply consistently confers calcifiers resistance to ocean acidification.

Functional analysis of CYP6ER1, a P450 gene associated with imidacloprid resistance in Nilaparvata lugens.

Science.gov (United States)

Pang, Rui; Chen, Meng; Liang, Zhikun; Yue, Xiangzhao; Ge, Hu; Zhang, Wenqing

2016-10-10

The cytochrome P450 CYP6ER1 has been reported to play an important role in imidacloprid resistance of the brown planthopper (BPH), Nilaparvata lugens, and is overexpressed in most resistant populations. In the present study, we confirmed that CYP6ER1 expression can be induced by certain levels of imidacloprid. Developmental expression analysis revealed that CYP6ER1 was expressed highly in the adult stage, and tissue distribution analysis showed that CYP6ER1 was expressed mainly in the fat body and midgut. RNA interference (RNAi) of CYP6ER1 and transgenic expression of CYP6ER1 in Drosophila melanogaster both suggested that the expression of CYP6ER1 is sufficient to confer imidacloprid resistance. Furthermore, we analyzed the interaction of imidacloprid and CYP6ER1 monooxygenase by using dynamic simulations and molecular docking. We found that Nitrogen atoms in the heterocycle of the imidacloprid molecule may bind to iron atoms in the center of the homology model of CYP6ER1 via 4,5-dihedro-1H-imidazole. This finding contributes to a better understanding of how CYP6ER1 takes part in the insecticide metabolism.

Nuclear translocation of IGF1R by intracellular amphiregulin contributes to the resistance of lung tumour cells to EGFR-TKI.

Science.gov (United States)

Guerard, Marie; Robin, Thomas; Perron, Pascal; Hatat, Anne-Sophie; David-Boudet, Laurence; Vanwonterghem, Laetitia; Busser, Benoit; Coll, Jean-Luc; Lantuejoul, Sylvie; Eymin, Beatrice; Hurbin, Amandine; Gazzeri, Sylvie

2018-04-28

Many Receptor Tyrosine Kinases translocate from the cell surface to the nucleus in normal and pathological conditions, including cancer. Here we report the nuclear expression of insulin-like growth factor-1 receptor (IGF1R) in primary human lung tumours. Using lung cancer cell lines and lung tumour xenografts, we demonstrate that the epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) gefitinib induces the nuclear accumulation of IGF1R in mucinous lung adenocarcinoma by a mechanism involving the intracellular re-localization of the growth factor amphiregulin. Amphiregulin allows the binding of IGF1R to importin-β1 and promotes its nuclear transport. The nuclear accumulation of IGF1R by amphiregulin induces cell cycle arrest through p21 WAF1/CIP1 upregulation, and prevents the induction of apoptosis in response to gefitinib. These results identify amphiregulin as the first nuclear localization signal-containing protein that interacts with IGF1R and allows its nuclear translocation. Furthermore they indicate that nuclear expression of IGF1R contributes to EGFR-TKI resistance in lung cancer. Copyright © 2018 Elsevier B.V. All rights reserved.

Inhibition of the multidrug resistance P-glycoprotein: time for a change of strategy?

Science.gov (United States)

Callaghan, Richard; Luk, Frederick; Bebawy, Mary

2014-04-01

P-glycoprotein (P-gp) is a key player in the multidrug-resistant phenotype in cancer. The protein confers resistance by mediating the ATP-dependent efflux of an astonishing array of anticancer drugs. Its broad specificity has been the subject of numerous attempts to inhibit the protein and restore the efficacy of anticancer drugs. The general strategy has been to develop compounds that either compete with anticancer drugs for transport or act as direct inhibitors of P-gp. Despite considerable in vitro success, there are no compounds currently available to "block" P-gp-mediated resistance in the clinic. The failure may be attributed to toxicity, adverse drug interaction, and numerous pharmacokinetic issues. This review provides a description of several alternative approaches to overcome the activity of P-gp in drug-resistant cells. These include 1) drugs that specifically target resistant cells, 2) novel nanotechnologies to provide high-dose, targeted delivery of anticancer drugs, 3) compounds that interfere with nongenomic transfer of resistance, and 4) approaches to reduce the expression of P-gp within tumors. Such approaches have been developed through the pursuit of greater understanding of resistance mediators such as P-gp, and they show considerable potential for further application.

Loss of the RNA polymerase III repressor MAF1 confers obesity resistance.

Science.gov (United States)

Bonhoure, Nicolas; Byrnes, Ashlee; Moir, Robyn D; Hodroj, Wassim; Preitner, Frédéric; Praz, Viviane; Marcelin, Genevieve; Chua, Streamson C; Martinez-Lopez, Nuria; Singh, Rajat; Moullan, Norman; Auwerx, Johan; Willemin, Gilles; Shah, Hardik; Hartil, Kirsten; Vaitheesvaran, Bhavapriya; Kurland, Irwin; Hernandez, Nouria; Willis, Ian M

2015-05-01

MAF1 is a global repressor of RNA polymerase III transcription that regulates the expression of highly abundant noncoding RNAs in response to nutrient availability and cellular stress. Thus, MAF1 function is thought to be important for metabolic economy. Here we show that a whole-body knockout of Maf1 in mice confers resistance to diet-induced obesity and nonalcoholic fatty liver disease by reducing food intake and increasing metabolic inefficiency. Energy expenditure in Maf1(-/-) mice is increased by several mechanisms. Precursor tRNA synthesis was increased in multiple tissues without significant effects on mature tRNA levels, implying increased turnover in a futile tRNA cycle. Elevated futile cycling of hepatic lipids was also observed. Metabolite profiling of the liver and skeletal muscle revealed elevated levels of many amino acids and spermidine, which links the induction of autophagy in Maf1(-/-) mice with their extended life span. The increase in spermidine was accompanied by reduced levels of nicotinamide N-methyltransferase, which promotes polyamine synthesis, enables nicotinamide salvage to regenerate NAD(+), and is associated with obesity resistance. Consistent with this, NAD(+) levels were increased in muscle. The importance of MAF1 for metabolic economy reveals the potential for MAF1 modulators to protect against obesity and its harmful consequences. © 2015 Bonhoure et al.; Published by Cold Spring Harbor Laboratory Press.

Extremely High Prevalence of Metronidazole-Resistant Helicobacter pylori Strains in Mountain People (Karen and Hmong) in Thailand.

Science.gov (United States)

Vilaichone, Ratha-korn; Ratanachu-Ek, Thawee; Gamnarai, Pornpen; Chaithongrat, Supakarn; Uchida, Tomahisa; Yamaoka, Yoshio; Mahachai, Varocha

2016-04-01

This study aimed to survey the prevalence, patterns of antibiotic resistance, and clinical factors associated with antibiotic resistance in Helicobacter pylori among the Karen and Hmong mountain people of Thailand. We recruited dyspeptic patients in the Maesod district, Tak Province, Thailand. All subjects underwent upper gastrointestinal endoscopy, and three antral gastric biopsies were obtained for rapid urease tests and culture. An epsilometer was used to determine the minimum inhibitory concentrations of amoxicillin (AMX), clarithromycin (CLR), metronidazole (MNZ), levofloxacin (LVX), ciprofloxacin (CIP), and tetracycline (TET). A total of 291 subjects were enrolled; 149 (51.2%) were infected with H. pylori. Helicobacter pylori infection was present in 47.1% of Thai, 51.7% of Karen, and 58.7% of Hmong subjects. Antibiotic resistance was present in 75.8% including AMX (0.8%), TET (0%), CLR (5.6%), MNZ (71.8%), CIP (19.4%), LVX (19.4%), and multidrug resistance in 21.8%. Karen subjects had the highest prevalence of MNZ resistance (84.6%), and Hmong subjects had the highest prevalence of fluoroquinolone (27.3%) and multidrug (34.1%) resistance. MNZ plus fluoroquinolone (14.5%) was the most common multidrug resistance. There was no association between clinical factors and antibiotic resistance. MNZ resistance was prevalent, whereas fluoroquinolone- and multidrug-resistant H. pylori infections are important problems in mountain people of Thailand. © The American Society of Tropical Medicine and Hygiene.

Interactions of ciprofloxacin (CIP), titanium dioxide (TiO{sub 2}) nanoparticles and natural organic matter (NOM) in aqueous suspensions

Energy Technology Data Exchange (ETDEWEB)

Fries, Elke, E-mail: elke.fries@bgr.de [Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Hannover (Germany); Bureau de Recherches Géologiques et Minières (BRGM), Orléans (France); Crouzet, Catherine; Michel, Caroline; Togola, Anne [Bureau de Recherches Géologiques et Minières (BRGM), Orléans (France)

2016-09-01

The aim of the present study was to investigate interactions of the antibiotic ciprofloxacin (CIP), titanium dioxide nanoparticles (TiO{sub 2} NP) and natural organic matter (NOM) in aqueous suspensions. The mean hydrodynamic diameter of particles of TiO{sub 2} NP and NOM in the suspensions ranged from 113 to 255 nm. During batch experiments the radioactivity resulting from {sup 14}CIP was determined in the filtrate (filter pore size 100 nm) by scintillation measurements. Up to 72 h, no significant sorption of NOM to TiO{sub 2} NP was observed at a TiO{sub 2} NP concentration of 5 mg/L. When the concentration of TiO{sub 2} NP was increased to 500 mg/L, a small amount of NOM of 9.5% ± 0.6% was sorbed at 72 h. The low sorption affinity of NOM on TiO{sub 2} NP surfaces could be explained by the negative charge of both components in alkaline media or by the low hydrophobicity of the NOM contents. At a TiO{sub 2} NP concentration of 5 mg L{sup −1}, the sorption of CIP on TiO{sub 2} NP was insignificant (TiO{sub 2} NP/CIP ratio: 10). When the TiO{sub 2} NP/CIP ratio was increased to 1000, a significant amount of 53.6% ± 7.2% of CIP was sorbed on TiO{sub 2} NP under equilibrium conditions at 64 h. In alkaline media, CIP is present mainly as zwitterions which have an affinity to sorb on negatively charged TiO{sub 2} NP surfaces. The sorption of CIP on TiO{sub 2} NP in the range of TiO{sub 2} NP concentrations currently estimated for municipal wastewater treatment plants is estimated to be rather low. The Freundlich sorption coefficients (K{sub F}) in the presence of NOM of 2167 L{sup n} mg mg{sup −n} kg{sup −1} was about 10 times lower than in the absence of NOM. This is an indication that the particle fraction of NOM < 100 nm could play a role as a carrier for ionic organic micro-pollutants as CIP. - Highlights: • Ciprofloxacine (CIP) and titanium dioxide nanoparticles (TiO{sub 2} NP) interact. • Organic carbon (OC) could influence such interactions. • Batch

Platelet-derived growth factor (PDGF)-signaling mediates radiation-induced apoptosis in human prostate cancer cells with loss of p53 function

International Nuclear Information System (INIS)

Kim, Harold E.; Han, Sue J.; Kasza, Thomas; Han, Richard; Choi, Hyeong-Seon; Palmer, Kenneth C.; Kim, Hyeong-Reh C.

1997-01-01

Platelet-derived growth factor (PDGF) signals a diversity of cellular responses in vitro, including cell proliferation, survival, transformation, and chemotaxis. PDGF functions as a 'competence factor' to induce a set of early response genes expressed in G 1 including p21 WAF1/CIP1 , a functional mediator of the tumor suppressor gene p53 in G 1 /S checkpoint. For PDGF-stimulated cells to progress beyond G 1 and transit the cell cycle completely, progression factors in serum such as insulin and IGF-1 are required. We have recently shown a novel role of PDGF in inducing apoptosis in growth-arrested murine fibroblasts. The PDGF-induced apoptosis is rescued by insulin, suggesting that G 1 /S checkpoint is a critical determinant for PDGF-induced apoptosis. Because recent studies suggest that radiation-induced signal transduction pathways interact with growth factor-mediated signaling pathways, we have investigated whether activation of the PDGF-signaling facilitates the radiation-induced apoptosis in the absence of functional p53. For this study we have used the 125-IL cell line, a mutant p53-containing, highly metastatic, and hormone-unresponsive human prostate carcinoma cell line. PDGF signaling is constitutively activated by transfection with a p28 v-sis expression vector, which was previously shown to activate PDGF α- and β- receptors. Although the basal level of p21 WAF1/CIP1 expression and radiation-induced apoptosis were not detectable in control 125-IL cells as would be predicted in mutant p53-containing cells, activation of PDGF-signaling induced expression of p21 WAF1/CIP1 and radiation-induced apoptosis. Our study suggests that the level of 'competence' growth factors including PDGF may be one of the critical determinants for radiation-induced apoptosis, especially in cells with loss of p53 function at the site of radiotherapy in vivo

The 21. CLI national conference

International Nuclear Information System (INIS)

Gouze, Jean-Remi; Lachaume, Jean-Luc; Revol, Henri; Vicaud, Alain; Rigal, Chantal; Laffitte, Olivier; Sabatier, Marie-Anne

2009-12-01

This document gathers contributions presented during a conference held in December 2009. This conference comprised three round tables. The first one addressed the problematic and role of the CLIs in front of third decennial visits and of a continued exploitation of reactors. The second one addressed the monitoring of the environment with contributions on the specific case of tritium (tritium releases by nuclear power plants, the discrete and general presence of tritium, and action of reflection groups organised by the ASN on the tritium issue). The third round table addressed public information on the impact of INBs and 'article 21' reports regarding several installations

Molecular characterization of Als1, an acetohydroxyacid synthase mutation conferring resistance to sulfonylurea herbicides in soybean.

Science.gov (United States)

Ghio, Cecilia; Ramos, María Laura; Altieri, Emiliano; Bulos, Mariano; Sala, Carlos A

2013-12-01

The AHAS gene family in soybean was characterized. The locus Als1 for sulfonylurea resistance was mapped and the resistant allele was characterized at the molecular level. Sulfonylurea (SU) resistance in soybean is controlled by Als1, a semi-dominant allele obtained by EMS mutagenesis over the cultivar Williams 82. The overall objective of this research was to map Als1 in the soybean genome and to determine the nucleotidic changes conferring resistance to SU. Four nucleotide sequences (GmAhas1-4) showing high homology with the Arabidopsis thaliana acetohydroxyacid synthase (AHAS, EC 4.1.3.18) gene sequence were identified by in silico analysis, PCR-amplified from the SU-resistant line BTK323STS and sequenced. Expression analysis showed that GmAhas1, located on chromosome 4 by in silico analysis, is the most expressed sequence in true leaves. F2:3 families derived from the cross between susceptible and resistant lines were evaluated for SU resistance. Mapping results indicate that the locus als1 is located on chromosome 4. Sequence comparison of GmAhas1 between BTK323STS and Williams 82 showed a single nucleotide change from cytosine to thymine at position 532. This transversion generates an amino acid change from proline to serine at position 197 (A. thaliana nomenclature) of the AHAS catalytic subunit. An allele-specific marker developed for the GmAhas1 mutant sequence cosegregated with SU resistance in the F2 population. Taking together, the mapping, expression and sequencing results indicate that the GmAhas1 sequence corresponds to the Als1 gene sequence controlling SU resistance in soybean. The molecular breeding tools described herein create the basis to speed up the identification of new mutations in soybean AHAS leading to enhanced levels of resistance to SU or to other families of AHAS inhibitor herbicides.

The 3p21.1-p21.3 hereditary vascular retinopathy locus increases the risk for Raynaud's phenomenon and migraine

NARCIS (Netherlands)

Hottenga, J. J.; Vanmolkot, K. R. J.; Kors, E. E.; Kheradmand Kia, S.; de Jong, P. T. V. M.; Haan, J.; Terwindt, G. M.; Frants, R. R.; Ferrari, M. D.; van den Maagdenberg, A. M. J. M.

2005-01-01

Previously, we described a large Dutch family with hereditary vascular retinopathy (HVR), Raynaud's phenomenon and migraine. A locus for HVR was mapped on chromosome 3p21.1-p21.3, but the gene has not yet been identified. The fact that all three disorders share a vascular aetiology prompted us to

Arecoline-induced growth arrest and p21WAF1 expression are dependent on p53 in rat hepatocytes

International Nuclear Information System (INIS)

Chou, W.-W.; Guh, J.-Y.; Tsai, J.-F.; Hwang, C.-C.; Chen, H.-C.; Huang, J.-S.; Yang, Y.-L.; Hung, W.-C.; Chuang, L.-Y.

2008-01-01

Betel-quid use is associated with the risk of liver cirrhosis and hepatocellular carcinoma and arecoline, the major alkaloid of betel-quid, is hepatotoxic in mice. Therefore, we studied the cytotoxic and genotoxic effects of arecoline in normal rat hepatocytes (Clone-9 cells). Arecoline dose-dependently (0.1-1 mM) decreased cell cycle-dependent proliferation while inducing DNA damage at 24 h. Moreover, arecoline (1 mM)-induced apoptosis and necrosis at 24 h. Arecoline dose-dependently (0.1-0.5 mM) increased transforming growth factor-β (TGF-β) mRNA, gene transcription and bioactivity and neutralizing TGF-β antibody attenuated arecoline (0.5 mM)-inhibited cell proliferation at 24 h. Arecoline (0.5 mM) also increased p21 WAF1 protein expression and p21 WAF1 gene transcription. Moreover, arecoline (0.5 mM) time-dependently (8-24 h) increased p53 serine 15 phosphorylation. Pifithrin-α (p53 inhibitor) and the loss of the two p53-binding elements in the p21 WAF1 gene promoter attenuated arecoline-induced p21 WAF1 gene transcription at 24 h. Pifithrin-α also attenuated arecoline (0.5 mM)-inhibited cell proliferation at 24 h. We concluded that arecoline induces cytotoxicity, DNA damage, G 0 /G 1 cell cycle arrest, TGF-β1, p21 WAF1 and activates p53 in Clone-9 cells. Moreover, arecoline-induced p21 WAF1 is dependent on p53 while arecoline-inhibited growth is dependent on both TGF-β and p53

CYP6 P450 enzymes and ACE-1 duplication produce extreme and multiple insecticide resistance in the malaria mosquito Anopheles gambiae.

Science.gov (United States)

Edi, Constant V; Djogbénou, Luc; Jenkins, Adam M; Regna, Kimberly; Muskavitch, Marc A T; Poupardin, Rodolphe; Jones, Christopher M; Essandoh, John; Kétoh, Guillaume K; Paine, Mark J I; Koudou, Benjamin G; Donnelly, Martin J; Ranson, Hilary; Weetman, David

2014-03-01

Malaria control relies heavily on pyrethroid insecticides, to which susceptibility is declining in Anopheles mosquitoes. To combat pyrethroid resistance, application of alternative insecticides is advocated for indoor residual spraying (IRS), and carbamates are increasingly important. Emergence of a very strong carbamate resistance phenotype in Anopheles gambiae from Tiassalé, Côte d'Ivoire, West Africa, is therefore a potentially major operational challenge, particularly because these malaria vectors now exhibit resistance to multiple insecticide classes. We investigated the genetic basis of resistance to the most commonly-applied carbamate, bendiocarb, in An. gambiae from Tiassalé. Geographically-replicated whole genome microarray experiments identified elevated P450 enzyme expression as associated with bendiocarb resistance, most notably genes from the CYP6 subfamily. P450s were further implicated in resistance phenotypes by induction of significantly elevated mortality to bendiocarb by the synergist piperonyl butoxide (PBO), which also enhanced the action of pyrethroids and an organophosphate. CYP6P3 and especially CYP6M2 produced bendiocarb resistance via transgenic expression in Drosophila in addition to pyrethroid resistance for both genes, and DDT resistance for CYP6M2 expression. CYP6M2 can thus cause resistance to three distinct classes of insecticide although the biochemical mechanism for carbamates is unclear because, in contrast to CYP6P3, recombinant CYP6M2 did not metabolise bendiocarb in vitro. Strongly bendiocarb resistant mosquitoes also displayed elevated expression of the acetylcholinesterase ACE-1 gene, arising at least in part from gene duplication, which confers a survival advantage to carriers of additional copies of resistant ACE-1 G119S alleles. Our results are alarming for vector-based malaria control. Extreme carbamate resistance in Tiassalé An. gambiae results from coupling of over-expressed target site allelic variants with

[Antimicrobial resistance of Bartonella bacilliformis strains from regions endemic to bartonellosis in Peru].

Science.gov (United States)

Mendoza-Mujica, Giovanna; Flores-León, Diana

2015-10-01

To evaluate in vitro antimicrobial susceptibility to chloramphenicol (CHL) and ciprofloxacin (CIP) in strains of Bartonella bacilliformis from areas that are endemic to Bartonellosis in Peru, through three laboratory methods. Antimicrobial susceptibility to CHL and CIP from 100 strains of Bartonella bacilliformis isolated in patients from the regions of Ancash, Cusco, Cajamarca, Lima and La Libertad were evaluated. Strains were evaluated by: disk diffusion, E-test and agar dilution. 26% of the strains of Bartonella bacilliformis evaluated were resistant to CIP and 1% to CHL. Similar patterns of antimicrobial sensitivity / resistance were obtained in all three methods. Bartonella bacilliformis strains circulating in Peru have high levels of in vitro resistance to CIP, so it is advisable to expand research on the use of drug treatment regimens of the Bartonellosis. The methods of E-test and disk diffusion were the most suitable for assessment in vitro of antimicrobial susceptibility of the microorganism.

Error-prone PCR mutation of Ls-EPSPS gene from Liriope spicata conferring to its enhanced glyphosate-resistance.

Science.gov (United States)

Mao, Chanjuan; Xie, Hongjie; Chen, Shiguo; Valverde, Bernal E; Qiang, Sheng

2017-09-01

Liriope spicata (Thunb.) Lour has a unique LsEPSPS structure contributing to the highest-ever-recognized natural glyphosate tolerance. The transformed LsEPSPS confers increased glyphosate resistance to E. coli and A. thaliana. However, the increased glyphosate-resistance level is not high enough to be of commercial value. Therefore, LsEPSPS was subjected to error-prone PCR to screen mutant EPSPS genes capable of endowing higher resistance levels. A mutant designated as ELs-EPSPS having five mutated amino acids (37Val, 67Asn, 277Ser, 351Gly and 422Gly) was selected for its ability to confer improved resistance to glyphosate. Expression of ELs-EPSPS in recombinant E. coli BL21 (DE3) strains enhanced resistance to glyphosate in comparison to both the LsEPSPS-transformed and -untransformed controls. Furthermore, transgenic ELs-EPSPS A. thaliana was about 5.4 fold and 2-fold resistance to glyphosate compared with the wild-type and the Ls-EPSPS-transgenic plants, respectively. Therefore, the mutated ELs-EPSPS gene has potential value for has potential for the development of glyphosate-resistant crops. Copyright © 2016 Elsevier Inc. All rights reserved.

Cisplatin-resistant lung cancer cell–derived exosomes increase cisplatin resistance of recipient cells in exosomal miR-100–5p-dependent manner

Directory of Open Access Journals (Sweden)

Qin X

2017-05-01

Full Text Available Xiaobing Qin,1,2,* Shaorong Yu,1,3,* Leilei Zhou,1,4 Meiqi Shi,3 Yong Hu,1 Xiaoyue Xu,1 Bo Shen,1 Siwen Liu,1 Dali Yan,1 Jifeng Feng1,3 1Research Center for Clinical Oncology, Affiliated Cancer Hospital of Nanjing Medical University, Jiangsu Cancer Hospital and Jiangsu Institute of Cancer Research, Nanjing, 2Department of Oncology, Xuzhou First People’s Hospital, Xuzhou, 3Department of Oncology, Affiliated Cancer Hospital of Nanjing Medical University, Jiangsu Cancer Hospital and Jiangsu Institute of Cancer Research, Nanjing, 4Department of Oncology, Affiliated Huai’an Hospital of Nanjing Medical University, Huai’an, Jiangsu, China *These authors have contributed equally to this work Abstract: Exosomes derived from lung cancer cells confer cisplatin (DDP resistance to other cancer cells. However, the underlying mechanism is still unknown. A549 resistance to DDP (A549/DDP was established. Microarray was used to analyze microRNA (miRNA expression profiles of A549 cells, A549/DDP cells, A549 exosomes, and A549/DDP exosomes. There was a strong correlation of miRNA profiles between exosomes and their maternal cells. A total of 11 miRNAs were significantly upregulated both in A549/DDP cells compared with A549 cells and in exosomes derived from A549/DDP cells in contrast to exosomes from A549 cells. A total of 31 downregulated miRNAs were also observed. miR-100–5p was the most prominent decreased miRNA in DDP-resistant exosomes compared with the corresponding sensitive ones. Downregulated miR-100–5p was proved to be involved in DDP resistance in A549 cells, and mammalian target of rapamycin (mTOR expression was reverse regulated by miR-100–5p. Exosomes confer recipient cells’ resistance to DDP in an exosomal miR-100–5p-dependent manner with mTOR as its potential target both in vitro and in vivo. Exosomes from DDP-resistant lung cancer cells A549 can alter other lung cancer cells’ sensitivity to DDP in exosomal miR-100–5p

Naturally selected hepatitis C virus polymorphisms confer broad neutralizing antibody resistance.

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Bailey, Justin R; Wasilewski, Lisa N; Snider, Anna E; El-Diwany, Ramy; Osburn, William O; Keck, Zhenyong; Foung, Steven K H; Ray, Stuart C

2015-01-01

For hepatitis C virus (HCV) and other highly variable viruses, broadly neutralizing mAbs are an important guide for vaccine development. The development of resistance to anti-HCV mAbs is poorly understood, in part due to a lack of neutralization testing against diverse, representative panels of HCV variants. Here, we developed a neutralization panel expressing diverse, naturally occurring HCV envelopes (E1E2s) and used this panel to characterize neutralizing breadth and resistance mechanisms of 18 previously described broadly neutralizing anti-HCV human mAbs. The observed mAb resistance could not be attributed to polymorphisms in E1E2 at known mAb-binding residues. Additionally, hierarchical clustering analysis of neutralization resistance patterns revealed relationships between mAbs that were not predicted by prior epitope mapping, identifying 3 distinct neutralization clusters. Using this clustering analysis and envelope sequence data, we identified polymorphisms in E2 that confer resistance to multiple broadly neutralizing mAbs. These polymorphisms, which are not at mAb contact residues, also conferred resistance to neutralization by plasma from HCV-infected subjects. Together, our method of neutralization clustering with sequence analysis reveals that polymorphisms at noncontact residues may be a major immune evasion mechanism for HCV, facilitating viral persistence and presenting a challenge for HCV vaccine development.

Expression of multidrug resistance gene and P-glycoprotein in nasopharyngealcarcinoma cells after irradiation

International Nuclear Information System (INIS)

Wang Ruoyu; Wang Hui; Fan Kai; Lv Shen

2007-01-01

Objective: To mimick a clinical fractionated protocol of exposure to X-radiation in vitro in order to investigate the changes in the function of MDR1 and P-gp in nasopharyngeal carcinoma (NPC) CNE cell before and after irradiation to determine the sequential order of radiotherapy and chemotherapy or the time of chemotherapy after radiotherapy in the treatment of NPC. Methods: Exponentially growing CNE cells were treated with fractionated X-radiation with total dose of 10 Gy (2 Gy per day for 5 days consecutively) in vitro. The expression of MDR1 gene was examined in CNE cells before irradiation and on days 4,8,13,17 and 21 after irradiation by RT-PCR, and its protein P-gp were detected by immunocytochemistry. The function of multidrug resistance protein P-gp was examined by MTT method. Results: Expression of MDR1 gene was below the level of detection before irradiation. Irradiation induced an overexpression of MDR1 gene on day 4, expression of MDR1 was decreased from day 8 to day 21. The overall expression of MDR1 was significantly more than that before irradiation (P<0.05) Expression of P-gp was below the level of detection before irradiation, which demonstrated that irradiation induced an overexpression of P-gp. This overexpression was increased from day 8 to day 21. The overpression of MDR1 gene was maintained dining a short period, however, the emergence of overpression of protein P-gp was later than that of MDR1 gene. Resistance index was 1 for both pre-irradiation and on day 8, and up to 8,10,11.2 on days 13, 17 and 21, respectively. The change of resistance index was accordant with the condition of overexpression of P-gp . Conclusions: Expression of P-gp in nasopharyngeal carcinoma (NPC) CNE cell was below the level of detection before irradiation. Irradiation can induce an overexpression of MDR1 gene and its protein P-gp in CNE cells. The overexpression of MDR1 gene and its protein P-gp lasted a long term. (authors)

Mapping a Quantitative Trait Locus (QTL conferring pyrethroid resistance in the African malaria vector Anopheles funestus

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Hunt Richard H

2007-01-01

Full Text Available Abstract Background Pyrethroid resistance in Anopheles funestus populations has led to an increase in malaria transmission in southern Africa. Resistance has been attributed to elevated activities of cytochrome P450s but the molecular basis underlying this metabolic resistance is unknown. Microsatellite and SNP markers were used to construct a linkage map and to detect a quantitative trait locus (QTL associated with pyrethroid resistance in the FUMOZ-R strain of An. funestus from Mozambique. Results By genotyping 349 F2 individuals from 11 independent families, a single major QTL, rp1, at the telomeric end of chromosome 2R was identified. The rp1 QTL appears to present a major effect since it accounts for more than 60% of the variance in susceptibility to permethrin. This QTL has a strong additive genetic effect with respect to susceptibility. Candidate genes associated with pyrethroid resistance in other species were physically mapped to An. funestus polytene chromosomes. This showed that rp1 is genetically linked to a cluster of CYP6 cytochrome P450 genes located on division 9 of chromosome 2R and confirmed earlier reports that pyrethroid resistance in this strain is not associated with target site mutations (knockdown resistance. Conclusion We hypothesize that one or more of these CYP6 P450s clustered on chromosome 2R confers pyrethroid resistance in the FUMOZ-R strain of An. funestus.

Expression of P-glycoprotein, multidrug resistance-associated protein, glutathione-S-transferase pi and p53 in canine transmissible venereal tumor

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Daniel G. Gerardi

2014-01-01

Full Text Available The overexpression of proteins P-glycoprotein (P-gp, multidrug resistance-associated protein (MRP1, mutant p53, and the enzyme glutathione-S-transferase (GSTpi are related to resistance to chemotherapy in neoplasms. This study evaluated the expression of these markers by immunohistochemistry in two groups of canine TVT, without history of prior chemotherapy (TVT1, n=9 and in TVTs presented unsatisfactory clinical response to vincristine sulfate (TVT2, n=5. The percentage of specimens positively stained for P-gp, MRP1, GSTpi and p53 were, respectively 88.8%, 0%, 44.5% and 22.2% in TVT1 and 80%, 0%, 80% and 0% in TVT2. In TVT1, one specimen presented positive expression for three markers and four specimens for two markers. In TVT2, three specimens expressed P-gp and GSTpi. In conclusion, the canine TVTs studied expressed the four markers evaluated, but just P-gp and GSTpi were significantly expressed, mainly at cytoplasm and cytoplasm and nuclei, respectively, either before chemotherapy as after vincristine sulfate exposure. Future studies are needed to demonstrate the function of these two markers in conferring multidrug resistance (MDR or predict the response to chemotherapy in canine TVT.

ZEB1 Mediates Drug Resistance and EMT in p300-Deficient CRC.

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Lazarova, Darina; Bordonaro, Michael

2017-01-01

We discuss the hypothesis that ZEB1-Wnt-p300 signaling integrates epithelial to mesenchymal transition (EMT) and resistance to histone deacetylase inhibitors (HDACis) in colorectal cancer (CRC) cells. The HDACi butyrate, derived from dietary fiber, has been linked to CRC prevention, and other HDACis have been proposed as therapeutic agents against CRC. We have previously discussed that resistance to butyrate likely contributes to colonic carcinogenesis, and we have demonstrated that butyrate resistance leads to cross-resistance to cancer therapeutic HDACis. Deregulated Wnt signaling is the major initiating event in most CRC cases. One mechanism whereby butyrate and other HDACis exert their anti-CRC effects is via Wnt signaling hyperactivation, which promotes CRC cell apoptosis. The histone acetylases (HATs) CBP and p300 are mediators of Wnt transcriptional activity, and play divergent roles in the downstream consequences of Wnt signaling. CBP-mediated Wnt signaling is associated with cell proliferation and stem cell maintenance; whereas, p300-mediated Wnt activity is associated with differentiation. We have found that CBP and p300 differentially affect the ability of butyrate to influence Wnt signaling, apoptosis, and proliferation. ZEB 1 is a Wnt signaling-targeted gene, whose product is a transcription factor expressed at the invasive front of carcinomas where it promotes malignant progression and EMT. ZEB1 is typically a transcriptional repressor; however, when associated with p300, ZEB1 enhances transcription. These changes in ZEB1 activity likely affect the cancer cell phenotype. ZEB1 has been shown to promote resistance to chemotherapeutic agents, and expression of ZEB1 is upregulated in butyrate-resistant CRC cells that lack p300 expression. Since the expression of ZEB1 correlates with poor outcomes in cancer, ZEB represents a relevant therapeutic target. Here we propose that targeting the signaling network established by ZEB1, Wnt signaling, and p300

Rme1 is necessary for Mi-1-mediated resistance and acts early in the resistance pathway.

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Martinez de Ilarduya, Oscar; Nombela, Gloria; Hwang, Chin-Feng; Williamson, Valerie M; Muñiz, Mariano; Kaloshian, Isgouhi

2004-01-01

The tomato gene Mi-1 confers resistance to root-knot nematodes (Meloidogyne spp.), potato aphid, and whitefly. Using genetic screens, we have isolated a mutant, rme1 (resistance to Meloidogyne spp.), compromised in resistance to M. javanica and potato aphid. Here, we show that the rme1 mutant is also compromised in resistance to M. incognita, M. arenaria, and whitefly. In addition, using an Agrobacterium-mediated transient assay in leaves to express constitutive gain-of-function mutant Pto(L205D), we demonstrated that the rme1 mutation is not compromised in Pto-mediated hypersensitive response. Moreover, the mutation in rme1 does not result in increased virulence of pathogenic Pseudomonas syringae or Mi-1-virulent M. incognita. Using a chimeric Mi-1 construct, Mi-DS4, which confers constitutive cell death phenotype and A. rhizogenes root transformation, we showed that the Mi-1-mediated cell death pathway is intact in this mutant. Our results indicate that Rme1 is required for Mi-1-mediated resistance and acts either at the same step in the signal transduction pathway as Mi-1 or upstream of Mi-1.

TaPP2C1, a Group F2 Protein Phosphatase 2C Gene, Confers Resistance to Salt Stress in Transgenic Tobacco.

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Wei Hu

Full Text Available Group A protein phosphatases 2Cs (PP2Cs are essential components of abscisic acid (ABA signaling in Arabidopsis; however, the function of group F2 subfamily PP2Cs is currently less known. In this study, TaPP2C1 which belongs to group F2 was isolated and characterized from wheat. Expression of the TaPP2C1-GFP fusion protein suggested its ubiquitous localization within a cell. TaPP2C1 expression was downregulated by abscisic acid (ABA and NaCl treatments, but upregulated by H2O2 treatment. Overexpression of TaPP2C1 in tobacco resulted in reduced ABA sensitivity and increased salt resistance of transgenic seedlings. Additionally, physiological analyses showed that improved resistance to salt stress conferred by TaPP2C1 is due to the reduced reactive oxygen species (ROS accumulation, the improved antioxidant system, and the increased transcription of genes in the ABA-independent pathway. Finally, transgenic tobacco showed increased resistance to oxidative stress by maintaining a more effective antioxidant system. Taken together, these results demonstrated that TaPP2C1 negatively regulates ABA signaling, but positively regulates salt resistance. TaPP2C1 confers salt resistance through activating the antioxidant system and ABA-independent gene transcription process.

USH1K, a novel locus for type I Usher syndrome, maps to chromosome 10p11.21-q21.1.

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Jaworek, Thomas J; Bhatti, Rashid; Latief, Noreen; Khan, Shaheen N; Riazuddin, Saima; Ahmed, Zubair M

2012-10-01

We ascertained two large Pakistani consanguineous families (PKDF231 and PKDF608) segregating profound hearing loss, vestibular dysfunction, and retinitis pigmentosa; the defining features of Usher syndrome type 1 (USH1). To date, seven USH1 loci have been reported. Here, we map a novel locus, USH1K, on chromosome 10p11.21-q21.1. In family PKDF231, we performed a genome-wide linkage screen and found a region of homozygosity shared among the affected individuals at chromosome 10p11.21-q21.1. Meiotic recombination events in family PKDF231 define a critical interval of 11.74 cM (20.20 Mb) bounded by markers D10S1780 (63.83 cM) and D10S546 (75.57 cM). Affected individuals of family PKDF608 were also homozygous for chromosome 10p11.21-q21.1-linked STR markers. Of the 85 genes within the linkage interval, PCDH15, GJD4, FZD4, RET and LRRC18 were sequenced in both families, but no potential pathogenic mutation was identified. The USH1K locus overlaps the non-syndromic deafness locus DFNB33 raising the possibility that the two disorders may be caused by allelic mutations.

EHD1 confers resistance to cisplatin in non-small cell lung cancer by regulating intracellular cisplatin concentrations

International Nuclear Information System (INIS)

Gao, Jing; Meng, Qingwei; Zhao, Yanbin; Chen, Xuesong; Cai, Li

2016-01-01

Non-small cell lung cancer (NSCLC) is one of the most aggressive types of cancer. However, resistance to cisplatin (CDDP) remains a major challenge in NSCLC treatment. The purpose of this study was to investigate the ability of EHD1 [Eps15 homology (EH) domain - containing protein 1] to confer CDDP resistance in NSCLC cells and to investigate mechanisms of this resistance. The associations between EHD1 expression in NSCLC specimens and clinicopathological features, including prognosis, were assessed by immunohistochemistry (IHC). Using DNA microarrays, we performed a genome-wide analysis of cisplatin-resistant NSCLC cells to identify the involvement of the EHD1 gene in this resistance. We overexpressed and knocked down EHD1 in cell lines to investigate the effect of this gene on proliferation and apoptosis. A quantitative analytical method for assessing CDDP in cells was developed. High-performance liquid chromatography was used to measure the concentration of cisplatin in cells. The immunohistochemistry assay showed that adjuvant chemotherapy-treated NSCLC patients expressing EHD1 exhibited reduced OS compared with patients who did not express EHD1 (P = 0.01). Moreover, DNA microarrays indicated that the EHD1 gene was upregulated in CDDP- resistant NSCLC cells. The IC50 value of CDDP in cells that overexpressed EHD1 was 3.3-fold greater than that in the A549-control line, and the IC50 value of EHD1 knockdown cells was at least 5.2-fold lower than that of the control cells, as evidenced by a CCK-8 assay. We found that the percentage of early apoptotic cells was significantly decreased in A549-EHD1 cells, but the rates of early apoptosis were higher in the EHD1 knockdown cell line than in the A549/DDP control line, as indicated by a flow cytometry analysis. High-performance liquid chromatography (HPLC) showed that the total platinum level was lower in A549-EHD1 cells than in control cells, and the concentration of CDDP was higher in the EHD1 knockdown cells than in

Homology modelling of Drosophila cytochrome P450 enzymes associated with insecticide resistance.

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Jones, Robert T; Bakker, Saskia E; Stone, Deborah; Shuttleworth, Sally N; Boundy, Sam; McCart, Caroline; Daborn, Phillip J; ffrench-Constant, Richard H; van den Elsen, Jean M H

2010-10-01

Overexpression of the cytochrome P450 gene Cyp6g1 confers resistance against DDT and a broad range of other insecticides in Drosophila melanogaster Meig. In the absence of crystal structures of CYP6G1 or complexes with its substrates, structural studies rely on homology modelling and ligand docking to understand P450-substrate interactions. Homology models are presented for CYP6G1, a P450 associated with resistance to DDT and neonicotinoids, and two other enzymes associated with insecticide resistance in D. melanogaster, CYP12D1 and CYP6A2. The models are based on a template of the X-ray structure of the phylogenetically related human CYP3A4, which is known for its broad substrate specificity. The model of CYP6G1 has a much smaller active site cavity than the template. The cavity is also 'V'-shaped and is lined with hydrophobic residues, showing high shape and chemical complementarity with the molecular characteristics of DDT. Comparison of the DDT-CYP6G1 complex and a non-resistant CYP6A2 homology model implies that tight-fit recognition of this insecticide is important in CYP6G1. The active site can accommodate differently shaped substrates ranging from imidacloprid to malathion but not the pyrethroids permethrin and cyfluthrin. The CYP6G1, CYP12D1 and CYP6A2 homology models can provide a structural insight into insecticide resistance in flies overexpressing P450 enzymes with broad substrate specificities.

Inheritance of resistance to watermelon mosaic virus in the cucumber line TMG-1: tissue-specific expression and relationship to zucchini yellow mosaic virus resistance.

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Wai, T; Grumet, R

1995-09-01

The inbred cucumber (Cucumis sativus L.) line TMG-1 is resistant to three potyviruses:zucchini yellow mosaic virus (ZYMV), watermelon mosaic virus (WMV), and the watermelon strain of papaya ringspot virus (PRSV-W). The genetics of resistance to WMV and the relationship of WMV resistance to ZYMV resistance were examined. TMG-1 was crossed with WI-2757, a susceptible inbred line. F1, F2 and backcross progeny populations were screened for resistance to WMV and/or ZYMV. Two independently assorting factors conferred resistance to WMV. One resistance was conferred by a single recessive gene from TMG-1 (wmv-2). The second resistance was conferred by an epistatic interaction between a second recessive gene from TMG-1 (wmv-3) and either a dominant gene from WI-2757 (Wmv-4) or a third recessive gene from TMG-1 (wmv-4) located 20-30 cM from wmv-3. The two resistances exhibited tissue-specific expression. Resistance conferred by wmv-2 was expressed in the cotyledons and throughout the plant. Resistance conferred by wmv-3 + Wmv-4 (or wmv-4) was expressed only in true leaves. The gene conferring resistance to ZYMV appeared to be the same as, or tightly linked to one of the WMV resistance genes, wmv-3.

A rapid seedling resistance assay identifies wild tomato lines that are resistant to Psuedomonas syringe pv. tomato race 1

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Bacterial speck caused by Pseudomonas syringae has historically been controlled by the Pto/Prf gene cluster. Emerging strains like P. syringae pv. tomato race 1 overcome resistance conferred by Pto/Prf, and can cause serious crop loss under appropriate environmental conditions. We developed a rapid ...

A third component of the human cytomegalovirus terminase complex is involved in letermovir resistance.

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Chou, Sunwen

2017-12-01

Letermovir is a human cytomegalovirus (CMV) terminase inhibitor that was clinically effective in a Phase III prevention trial. In vitro studies have shown that viral mutations conferring letermovir resistance map primarily to the UL56 component of the terminase complex and uncommonly to UL89. After serial culture of a baseline CMV laboratory strain under letermovir, mutation was observed in a third terminase component in 2 experiments, both resulting in amino acid substitution P91S in gene UL51 and adding to a pre-existing UL56 mutation. Recombinant phenotyping indicated that P91S alone conferred 2.1-fold increased letermovir resistance (EC50) over baseline, and when combined with UL56 mutation S229F or R369M, multiplied the level of resistance conferred by those mutations by 3.5-7.7-fold. Similarly a combination of UL56 mutations S229F, L254F and L257I selected in the same experiment conferred 54-fold increased letermovir EC50 over baseline, but 290-fold when combined with UL51 P91S. The P91S mutant was not perceptibly growth impaired. Although pUL51 is essential for normal function of the terminase complex, its biological significance is not well understood. Letermovir resistance mutations mapping to 3 separate genes, and their multiplier effect on the level of resistance, suggest that the terminase components interactively contribute to the structure of a letermovir antiviral target. The diagnostic importance of the UL51 P91S mutation arises from its potential to augment the letermovir resistance of some UL56 mutations at low fitness cost. Copyright © 2017 Elsevier B.V. All rights reserved.

Vive la résistance: reviving resistance for 21st century conservation.

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Nimmo, D G; Mac Nally, R; Cunningham, S C; Haslem, A; Bennett, A F

2015-09-01

Confronted with increasing anthropogenic change, conservation in the 21st century requires a sound understanding of how ecological systems change during disturbance. We highlight the benefits of recognizing two distinct components of change in an ecological unit (i.e., ecosystem, community, population): 'resistance', the ability to withstand disturbance; and 'resilience', the capacity to recover following disturbance. By adopting a 'resistance-resilience' framework, important insights for conservation can be gained into: (i) the key role of resistance in response to persistent disturbance, (ii) the intrinsic attributes of an ecological unit associated with resistance and resilience, (iii) the extrinsic environmental factors that influence resistance and resilience, (iv) mechanisms that confer resistance and resilience, (v) the post-disturbance status of an ecological unit, (vi) the nature of long-term ecological changes, and (vii) policy-relevant ways of communicating the ecological impacts of disturbance processes. Copyright © 2015 Elsevier Ltd. All rights reserved.

GRL-09510, a Unique P2-Crown-Tetrahydrofuranylurethane -Containing HIV-1 Protease Inhibitor, Maintains Its Favorable Antiviral Activity against Highly-Drug-Resistant HIV-1 Variants in vitro

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Amano, Masayuki; Miguel Salcedo-Gómez, Pedro; Yedidi, Ravikiran S.; Delino, Nicole S.; Nakata, Hirotomo; Venkateswara Rao, Kalapala; Ghosh, Arun K.; Mitsuya, Hiroaki

2017-09-25

We report that GRL-09510, a novel HIV-1 protease inhibitor (PI) containing a newly-generated P2-crown-tetrahydrofuranylurethane (Crwn-THF), a P2'-methoxybenzene, and a sulfonamide isostere, is highly active against laboratory and primary clinical HIV-1 isolates (EC50: 0.0014–0.0028 μM) with minimal cytotoxicity (CC50: 39.0 μM). Similarly, GRL-09510 efficiently blocked the replication of HIV-1NL4-3 variants, which were capable of propagating at high-concentrations of atazanavir, lopinavir, and amprenavir (APV). GRL-09510 was also potent against multi-drug-resistant clinical HIV-1 variants and HIV-2ROD. Under the selection condition, where HIV-1NL4-3 rapidly acquired significant resistance to APV, an integrase inhibitor raltegravir, and a GRL-09510 congener (GRL-09610), no variants highly resistant against GRL-09510 emerged over long-term in vitro passage of the virus. Crystallographic analysis demonstrated that the Crwn-THF moiety of GRL-09510 forms strong hydrogen-bond-interactions with HIV-1 protease (PR) active-site amino acids and is bulkier with a larger contact surface, making greater van der Waals contacts with PR than the bis-THF moiety of darunavir. The present data demonstrate that GRL-09510 has favorable features for treating patients infected with wild-type and/or multi-drug-resistant HIV-1 variants, that the newly generated P2-Crwn-THF moiety confers highly desirable anti-HIV-1 potency. The use of the novel Crwn-THF moiety sheds lights in the design of novel PIs.

ClbS Is a Cyclopropane Hydrolase That Confers Colibactin Resistance.

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Tripathi, Prabhanshu; Shine, Emilee E; Healy, Alan R; Kim, Chung Sub; Herzon, Seth B; Bruner, Steven D; Crawford, Jason M

2017-12-13

Certain commensal Escherichia coli contain the clb biosynthetic gene cluster that codes for small molecule prodrugs known as precolibactins. Precolibactins are converted to colibactins by N-deacylation; the latter are postulated to be genotoxic and to contribute to colorectal cancer formation. Though advances toward elucidating (pre)colibactin biosynthesis have been made, the functions and mechanisms of several clb gene products remain poorly understood. Here we report the 2.1 Å X-ray structure and molecular function of ClbS, a gene product that confers resistance to colibactin toxicity in host bacteria and which has been shown to be important for bacterial viability. The structure harbors a potential colibactin binding site and shares similarity to known hydrolases. In vitro studies using a synthetic colibactin analog and ClbS or an active site residue mutant reveal cyclopropane hydrolase activity that converts the electrophilic cyclopropane of the colibactins into an innocuous hydrolysis product. As the cyclopropane has been shown to be essential for genotoxic effects in vitro, this ClbS-catalyzed ring-opening provides a means for the bacteria to circumvent self-induced genotoxicity. Our study provides a molecular-level view of the first reported cyclopropane hydrolase and support for a specific mechanistic role of this enzyme in colibactin resistance.

RE@21 spotlight: most influential papers from the requirements engineering conference

NARCIS (Netherlands)

Glinz, Martin; Wieringa, Roelf J.

Since 2003, an award has been presented annually at the IEEE International Requirements Engineering Conference for the Most Influential Paper presented at the conference 10 years previously. In 2013, we celebrate 21 years of the Requirements Engineering Conference, and we use this as an opportunity

Ghana Science Association. 21st biennial conference. Program and abstracts book

International Nuclear Information System (INIS)

1999-08-01

The publication covers the program and abstracts of papers presented during the 21st biennial conference of the Ghana Science Association. The conference was held at the University of Ghana, Legon from 8th to 13th August 1999. The theme of the conference was S ustainable food Industry in Ghana in the 21st Century . The first part of the publication covers membership of various committees, list of sponsors and conference program among others. The second part is devoted to abstracts of papers presented during various scientific sessions. Papers have been grouped under the following subject areas: Biological and Medical Science, Physical Sciences, Food and Agriculture, Social Science Education and Policy Research and Poster Presentations. (E.A.)

PPARγ1 phosphorylation enhances proliferation and drug resistance in human fibrosarcoma cells

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Pang, Xiaojuan; Shu, Yuxin; Niu, Zhiyuan; Zheng, Wei; Wu, Haochen [State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing (China); Lu, Yan, E-mail: luyan@nju.edu.cn [State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing (China); Shen, Pingping, E-mail: ppshen@nju.edu.cn [State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing (China); Model Animal Research Center (MARC), Nanjing University, Nanjing (China)

2014-03-10

Post-translational regulation plays a critical role in the control of cell growth and proliferation. The phosphorylation of peroxisome proliferator-activated receptor γ (PPARγ) is the most important post-translational modification. The function of PPARγ phosphorylation has been studied extensively in the past. However, the relationship between phosphorylated PPARγ1 and tumors remains unclear. Here we investigated the role of PPARγ1 phosphorylation in human fibrosarcoma HT1080 cell line. Using the nonphosphorylation (Ser84 to alanine, S84A) and phosphorylation (Ser84 to aspartic acid, S84D) mutant of PPARγ1, the results suggested that phosphorylation attenuated PPARγ1 transcriptional activity. Meanwhile, we demonstrated that phosphorylated PPARγ1 promoted HT1080 cell proliferation and this effect was dependent on the regulation of cell cycle arrest. The mRNA levels of cyclin-dependent kinase inhibitor (CKI) p21{sup Waf1/Cip1} and p27{sup Kip1} descended in PPARγ1{sup S84D} stable HT1080 cell, whereas the expression of p18{sup INK4C} was not changed. Moreover, compared to the PPARγ1{sup S84A}, PPARγ1{sup S84D} up-regulated the expression levels of cyclin D1 and cyclin A. Finally, PPARγ1 phosphorylation reduced sensitivity to agonist rosiglitazone and increased resistance to anticancer drug 5-fluorouracil (5-FU) in HT1080 cell. Our findings establish PPARγ1 phosphorylation as a critical event in human fibrosarcoma growth. These findings raise the possibility that chemical compounds that prevent the phosphorylation of PPARγ1 could act as anticancer drugs. - Highlights: • Phosphorylation attenuates PPARγ1 transcriptional activity. • Phosphorylated PPARγ1 promotes HT1080 cells proliferation. • PPARγ1 phosphorylation regulates cell cycle by mediating expression of cell cycle regulators. • PPARγ1 phosphorylation reduces sensitivity to agonist and anticancer drug. • Our findings establish PPARγ1 phosphorylation as a critical event in HT1080

p21/Cyclin E pathway modulates anticlastogenic function of Bmi-1 in cancer cells

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Deng, Wen; Zhou, Yuan; Tiwari, Agnes FY; Su, Hang; Yang, Jie; Zhu, Dandan; Lau, Victoria Ming Yi; Hau, Pok Man; Yip, Yim Ling; Cheung, Annie LM; Guan, Xin-Yuan; Tsao, Sai Wah

2015-01-01

Apart from regulating stem cell self-renewal, embryonic development and proliferation, Bmi-1 has been recently reported to be critical in the maintenance of genome integrity. In searching for novel mechanisms underlying the anticlastogenic function of Bmi-1, we observed, for the first time, that Bmi-1 positively regulates p21 expression. We extended the finding that Bmi-1 deficiency induced chromosome breaks in multiple cancer cell models. Interestingly, we further demonstrated that knockdown of cyclin E or ectopic overexpression of p21 rescued Bmi-1 deficiency-induced chromosome breaks. We therefore conclude that p21/cyclin E pathway is crucial in modulating the anticlastogenic function of Bmi-1. As it is well established that the overexpression of cyclin E potently induces genome instability and p21 suppresses the function of cyclin E, the novel and important implication from our findings is that Bmi-1 plays an important role in limiting genomic instability in cylin E-overexpressing cancer cells by positive regulation of p21. PMID:25131797

Cellular expression of gH confers resistance to herpes simplex virus type-1 entry

International Nuclear Information System (INIS)

Scanlan, Perry M.; Tiwari, Vaibhav; Bommireddy, Susmita; Shukla, Deepak

2003-01-01

Entry of herpes simplex virus-1 (HSV-1) into cells requires a concerted action of four viral glycoproteins gB, gD, and gH-gL. Previously, cell surface expression of gD had been shown to confer resistance to HSV-1 entry. To investigate any similar effects caused by other entry glycoproteins, gB and gH-gL were coexpressed with Nectin-1 in Chinese hamster ovary (CHO) cells. Interestingly, cellular expression of gB had no effect on HSV-1(KOS) entry. In contrast, entry was significantly reduced in cells expressing gH-gL. This effect was further analyzed by expressing gH and gL separately. Cells expressing gL were normally susceptible, whereas gH-expressing cells were significantly resistant. Further experiments suggested that the gH-mediated interference phenomenon was not specific to any particular gD receptor and was also observed in gH-expressing HeLa cells. Moreover, contrary to a previous report, gL-independent cell surface expression of gH was detected in stably transfected CHO cells, possibly implicating cell surface gH in the interference phenomenon. Thus, taken together these findings indicate that cellular expression of gH interferes with HSV-1 entry

Y-box-binding protein-1 (YB-1) promotes cell proliferation, adhesion and drug resistance in diffuse large B-cell lymphoma

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Miao, Xiaobing; Wu, Yaxun [Department of Pathology, Affiliated Cancer Hospital of Nantong University, Nantong 226361, Jiangsu (China); Wang, Yuchan [Department of Pathogen, Medical College, Nantong University, Nantong 226001, Jiangsu (China); Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Nantong University, Nantong 226001, Jiangsu (China); Zhu, Xinghua; Yin, Haibing [Department of Pathology, Affiliated Cancer Hospital of Nantong University, Nantong 226361, Jiangsu (China); He, Yunhua [Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Nantong University, Nantong 226001, Jiangsu (China); Li, Chunsun; Liu, Yushan; Lu, Xiaoyun; Chen, Yali; Shen, Rong [Department of Pathology, Affiliated Cancer Hospital of Nantong University, Nantong 226361, Jiangsu (China); Xu, Xiaohong, E-mail: xuxiaohongnantong@126.com [Department of Oncology, Affiliated Cancer Hospital of Nantong University, Nantong 226361, Jiangsu (China); He, Song, E-mail: hesongnt@126.com [Department of Pathology, Affiliated Cancer Hospital of Nantong University, Nantong 226361, Jiangsu (China)

2016-08-15

YB-1 is a multifunctional protein, which has been shown to correlate with resistance to treatment of various tumor types. This study investigated the expression and biologic function of YB-1 in diffuse large B-cell lymphoma (DLBCL). Immunohistochemical analysis showed that the expression statuses of YB-1 and pYB-1{sup S102} were reversely correlated with the clinical outcomes of DLBCL patients. In addition, we found that YB-1 could promote the proliferation of DLBCL cells by accelerating the G1/S transition. Ectopic expression of YB-1 could markedly increase the expression of cell cycle regulators cyclin D1 and cyclin E. Furthermore, we found that adhesion of DLBCL cells to fibronectin (FN) could increase YB-1 phosphorylation at Ser102 and pYB-1{sup S102} nuclear translocation. In addition, overexpression of YB-1 could increase the adhesion of DLBCL cells to FN. Intriguingly, we found that YB-1 overexpression could confer drug resistance through cell-adhesion dependent and independent mechanisms in DLBCL. Silencing of YB-1 could sensitize DLBCL cells to mitoxantrone and overcome cell adhesion-mediated drug resistance (CAM-DR) phenotype in an AKT-dependent manner. - Highlights: • The expression statuses of YB-1 and pYB-1{sup S102} are reversely correlated with outcomes of DLBCL patients. • YB-1 promotes cell proliferation by accelerating G1/S transition in DLBCL. • YB-1 confers drug resistance to mitoxantrone in DLBCL.

Transport characteristic in current-in-plane (CIP) geometry of La0.8Sr0.2MnO3/Co heterostructure

International Nuclear Information System (INIS)

Jin, K.X.; Zhao, S.G.; Chen, C.L.

2009-01-01

The thousand-fold change in the resistance with increase in temperature has been observed in the current-in-plane (CIP) geometry of the La 0.8 Sr 0.2 MnO 3 /Co heterostructure prepared using a sol-gel method. The CIP geometry below 300 K exhibits the variable-range hopping (VRH) mechanism. The current-voltage characteristic is nonlinear and the fitting shows that the exponent n decreases with increasing the temperature, which is attributed to the lattice mismatch between the LSMO film and the Co substrate.

Transgenic expression of BRCA1 disturbs hematopoietic stem and progenitor cells quiescence and function

International Nuclear Information System (INIS)

Bai, Lin; Shi, Guiying; Zhang, Xu; Dong, Wei; Zhang, Lianfeng

2013-01-01

The balance between quiescence and proliferation of HSCs is an important regulator of hematopoiesis. Loss of quiescence frequently results in HSCs exhaustion, which underscores the importance of tight regulation of proliferation in these cells. Studies have indicated that cyclin-dependent kinases are involved in the regulation of quiescence in HSCs. BRCA1 plays an important role in the repair of DNA double-stranded breaks, cell cycle, apoptosis and transcription. BRCA1 is expressed in the bone marrow. However, the function of BRCA1 in HSCs is unknown. In our study, we generated BRCA1 transgenic mice to investigate the effects of BRCA1 on the mechanisms of quiescence and differentiation in HSCs. The results demonstrate that over-expression of BRCA1 in the bone marrow impairs the development of B lymphocytes. Furthermore, BRCA1 induced an increase in the number of LSKs, LT-HSCs, ST-HSCs and MPPs. A competitive transplantation assay found that BRCA1 transgenic mice failed to reconstitute hematopoiesis. Moreover, BRCA1 regulates the expression of p21 waf1 /cip1 and p57 kip2 , which results in a loss of quiescence in LSKs. Together, over-expression of BRCA1 in bone marrow disrupted the quiescent of LSKs, induced excessive accumulation of LSKs, and disrupted differentiation of the HSCs, which acts through the down-regulated of p21 waf1 /cip1 and p57 kip2 . - Highlights: • Over-expression of BRCA1 results in impaired B lymphocyte development. • BRCA1 transgenic mice disrupted the quiescent of LSKs, induced excessive accumulation of LSKs. • BRCA1 impairs the function of HSCs through the down-regulated of p21 waf1/cip1 and p57 kip2

Transgenic expression of BRCA1 disturbs hematopoietic stem and progenitor cells quiescence and function

Energy Technology Data Exchange (ETDEWEB)

Bai, Lin; Shi, Guiying; Zhang, Xu; Dong, Wei; Zhang, Lianfeng, E-mail: zhanglf@cnilas.org

2013-10-15

The balance between quiescence and proliferation of HSCs is an important regulator of hematopoiesis. Loss of quiescence frequently results in HSCs exhaustion, which underscores the importance of tight regulation of proliferation in these cells. Studies have indicated that cyclin-dependent kinases are involved in the regulation of quiescence in HSCs. BRCA1 plays an important role in the repair of DNA double-stranded breaks, cell cycle, apoptosis and transcription. BRCA1 is expressed in the bone marrow. However, the function of BRCA1 in HSCs is unknown. In our study, we generated BRCA1 transgenic mice to investigate the effects of BRCA1 on the mechanisms of quiescence and differentiation in HSCs. The results demonstrate that over-expression of BRCA1 in the bone marrow impairs the development of B lymphocytes. Furthermore, BRCA1 induced an increase in the number of LSKs, LT-HSCs, ST-HSCs and MPPs. A competitive transplantation assay found that BRCA1 transgenic mice failed to reconstitute hematopoiesis. Moreover, BRCA1 regulates the expression of p21{sup waf1}/cip1 and p57{sup kip2}, which results in a loss of quiescence in LSKs. Together, over-expression of BRCA1 in bone marrow disrupted the quiescent of LSKs, induced excessive accumulation of LSKs, and disrupted differentiation of the HSCs, which acts through the down-regulated of p21{sup waf1}/cip1 and p57{sup kip2}. - Highlights: • Over-expression of BRCA1 results in impaired B lymphocyte development. • BRCA1 transgenic mice disrupted the quiescent of LSKs, induced excessive accumulation of LSKs. • BRCA1 impairs the function of HSCs through the down-regulated of p21{sup waf1/cip1} and p57{sup kip2}.

CDK2 phosphorylation of Smad2 disrupts TGF-beta transcriptional regulation in resistant primary bone marrow myeloma cells.

Science.gov (United States)

Baughn, Linda B; Di Liberto, Maurizio; Niesvizky, Ruben; Cho, Hearn J; Jayabalan, David; Lane, Joseph; Liu, Fang; Chen-Kiang, Selina

2009-02-15

Resistance to growth suppression by TGF-beta1 is common in cancer; however, mutations in this pathway are rare in hematopoietic malignancies. In multiple myeloma, a fatal cancer of plasma cells, malignant cells accumulate in the TGF-beta-rich bone marrow due to loss of both cell cycle and apoptotic controls. Herein we show that TGF-beta activates Smad2 but fails to induce cell cycle arrest or apoptosis in primary bone marrow myeloma and human myeloma cell lines due to its inability to activate G(1) cyclin-dependent kinase (CDK) inhibitors (p15(INK4b), p21(CIP1/WAF1), p27(KIP1), p57(KIP2)) or to repress c-myc and Bcl-2 transcription. Correlating with aberrant activation of CDKs, CDK-dependent phosphorylation of Smad2 on Thr(8) (pT8), a modification linked to impaired Smad activity, is elevated in primary bone marrow myeloma cells, even in asymptomatic monoclonal gammopathy of undetermined significance. Moreover, CDK2 is the predominant CDK that phosphorylates Smad2 on T8 in myeloma cells, leading to inhibition of Smad2-Smad4 association that precludes transcriptional regulation by Smad2. Our findings provide the first direct evidence that pT8 Smad2 couples dysregulation of CDK2 to TGF-beta resistance in primary cancer cells, and they suggest that disruption of Smad2 function by CDK2 phosphorylation acts as a mechanism for TGF-beta resistance in multiple myeloma.

Pancreatic adenocarcinoma upregulated factor (PAUF) confers resistance to pancreatic cancer cells against oncolytic parvovirus H-1 infection through IFNA receptor-mediated signaling

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Kaowinn, Sirichat; Cho, Il-Rae; Moon, Jeong; Jun, Seung Won; Kim, Chang Seok [BK21+, Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-736 (Korea, Republic of); Kang, Ho Young [Department of Microbiology, Pusan National University, Busan 609-736 (Korea, Republic of); Kim, Manbok [Department of Medical Science, Dankook University College of Medicine, Cheonan 330-714 (Korea, Republic of); Koh, Sang Seok [Department of Biological Sciences, Dong-A University, Busan 604-714 (Korea, Republic of); Chung, Young-Hwa, E-mail: younghc@pusan.ac.kr [BK21+, Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-736 (Korea, Republic of)

2015-04-03

Pancreatic adenocarcinoma upregulated factor (PAUF), a novel oncogene, plays a crucial role in the development of pancreatic cancer, including its metastasis and proliferation. Therefore, PAUF-expressing pancreatic cancer cells could be important targets for oncolytic virus-mediated treatment. Panc-1 cells expressing PAUF (Panc-PAUF) showed relative resistance to parvovirus H-1 infection compared with Panc-1 cells expressing an empty vector (Panc-Vec). Of interest, expression of type I IFN-α receptor (IFNAR) was higher in Panc-PAUF cells than in Panc-Vec cells. Increased expression of IFNAR in turn increased the activation of Stat1 and Tyk2 in Panc-PAUF cells compared with that in Panc-Vec cells. Suppression of Tyk2 and Stat1, which are important downstream molecules for IFN-α signaling, sensitized pancreatic cancer cells to parvovirus H-1-mediated apoptosis. Further, constitutive suppression of PAUF sensitized Bxpc3 pancreatic cancer cells to parvovirus H-1 infection. Taken together, these results suggested that PAUF conferred resistance to pancreatic cancer cells against oncolytic parvovirus H-1 infection through IFNAR-mediated signaling. - Highlights: • PAUF confers resistance against oncolytic parvovirus H-1 infection. • PAUF enhances the expression of IFNAR in Panc-1 cells. • Increased activation of Tyk2 or Stat1 by PAUF provides resistance to parvovirus H-1-mediated apoptosis. • Constitutive inhibition of PAUF enhances parvovirus H-1-mediated oncolysis of Bxpc3 pancreatic cancer cells.

Pancreatic adenocarcinoma upregulated factor (PAUF) confers resistance to pancreatic cancer cells against oncolytic parvovirus H-1 infection through IFNA receptor-mediated signaling

International Nuclear Information System (INIS)

Kaowinn, Sirichat; Cho, Il-Rae; Moon, Jeong; Jun, Seung Won; Kim, Chang Seok; Kang, Ho Young; Kim, Manbok; Koh, Sang Seok; Chung, Young-Hwa

2015-01-01

Pancreatic adenocarcinoma upregulated factor (PAUF), a novel oncogene, plays a crucial role in the development of pancreatic cancer, including its metastasis and proliferation. Therefore, PAUF-expressing pancreatic cancer cells could be important targets for oncolytic virus-mediated treatment. Panc-1 cells expressing PAUF (Panc-PAUF) showed relative resistance to parvovirus H-1 infection compared with Panc-1 cells expressing an empty vector (Panc-Vec). Of interest, expression of type I IFN-α receptor (IFNAR) was higher in Panc-PAUF cells than in Panc-Vec cells. Increased expression of IFNAR in turn increased the activation of Stat1 and Tyk2 in Panc-PAUF cells compared with that in Panc-Vec cells. Suppression of Tyk2 and Stat1, which are important downstream molecules for IFN-α signaling, sensitized pancreatic cancer cells to parvovirus H-1-mediated apoptosis. Further, constitutive suppression of PAUF sensitized Bxpc3 pancreatic cancer cells to parvovirus H-1 infection. Taken together, these results suggested that PAUF conferred resistance to pancreatic cancer cells against oncolytic parvovirus H-1 infection through IFNAR-mediated signaling. - Highlights: • PAUF confers resistance against oncolytic parvovirus H-1 infection. • PAUF enhances the expression of IFNAR in Panc-1 cells. • Increased activation of Tyk2 or Stat1 by PAUF provides resistance to parvovirus H-1-mediated apoptosis. • Constitutive inhibition of PAUF enhances parvovirus H-1-mediated oncolysis of Bxpc3 pancreatic cancer cells

Dux4 induces cell cycle arrest at G1 phase through upregulation of p21 expression

International Nuclear Information System (INIS)

Xu, Hongliang; Wang, Zhaoxia; Jin, Suqin; Hao, Hongjun; Zheng, Lemin; Zhou, Boda; Zhang, Wei; Lv, He; Yuan, Yun

2014-01-01

Highlights: • Dux4 induced TE671 cell proliferation defect and G1 phase arrest. • Dux4 upregulated p21 expression without activating p53. • Silencing p21 rescued Dux4 mediated proliferation defect and cell cycle arrest. • Sp1 binding site was required for Dux4-induced p21 promoter activation. - Abstract: It has been implicated that Dux4 plays crucial roles in development of facioscapulohumeral dystrophy. But the underlying myopathic mechanisms and related down-stream events of this retrogene were far from clear. Here, we reported that overexpression of Dux4 in a cell model TE671 reduced cell proliferation rate, and increased G1 phase accumulation. We also determined the impact of Dux4 on p53/p21 signal pathway, which controls the checkpoint in cell cycle progression. Overexpression of Dux4 increased p21 mRNA and protein level, while expression of p53, phospho-p53 remained unchanged. Silencing p21 rescued Dux4 mediated proliferation defect and cell cycle arrest. Furthermore, we demonstrated that enhanced Dux4 expression increased p21 promoter activity and elevated expression of Sp1 transcription factor. Mutation of Sp1 binding site decreased dux4 induced p21 promoter activation. Chromatin immunoprecipitation (ChIP) assays confirmed the Dux4-induced binding of Sp1 to p21 promoter in vivo. These results suggest that Dux4 might induce proliferation inhibition and G1 phase arrest through upregulation of p21

Dux4 induces cell cycle arrest at G1 phase through upregulation of p21 expression

Energy Technology Data Exchange (ETDEWEB)

Xu, Hongliang; Wang, Zhaoxia; Jin, Suqin; Hao, Hongjun [Department of Neurology, Peking University First Hospital, Beijing 100034 (China); Zheng, Lemin [The Institute of Cardiovascular Sciences, Peking University Health Science Center, Key Laboratory of Molecular Cardiovascular Sciences of Education Ministry, Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides of Health Ministry, Beijing 100191 (China); Zhou, Boda [The Department of Cardiology, Peking University Third Hospital, Beijing 100191 (China); Zhang, Wei; Lv, He [Department of Neurology, Peking University First Hospital, Beijing 100034 (China); Yuan, Yun, E-mail: yuanyun2002@sohu.com [Department of Neurology, Peking University First Hospital, Beijing 100034 (China)

2014-03-28

Highlights: • Dux4 induced TE671 cell proliferation defect and G1 phase arrest. • Dux4 upregulated p21 expression without activating p53. • Silencing p21 rescued Dux4 mediated proliferation defect and cell cycle arrest. • Sp1 binding site was required for Dux4-induced p21 promoter activation. - Abstract: It has been implicated that Dux4 plays crucial roles in development of facioscapulohumeral dystrophy. But the underlying myopathic mechanisms and related down-stream events of this retrogene were far from clear. Here, we reported that overexpression of Dux4 in a cell model TE671 reduced cell proliferation rate, and increased G1 phase accumulation. We also determined the impact of Dux4 on p53/p21 signal pathway, which controls the checkpoint in cell cycle progression. Overexpression of Dux4 increased p21 mRNA and protein level, while expression of p53, phospho-p53 remained unchanged. Silencing p21 rescued Dux4 mediated proliferation defect and cell cycle arrest. Furthermore, we demonstrated that enhanced Dux4 expression increased p21 promoter activity and elevated expression of Sp1 transcription factor. Mutation of Sp1 binding site decreased dux4 induced p21 promoter activation. Chromatin immunoprecipitation (ChIP) assays confirmed the Dux4-induced binding of Sp1 to p21 promoter in vivo. These results suggest that Dux4 might induce proliferation inhibition and G1 phase arrest through upregulation of p21.

Transcriptome analysis highlights defense and signaling pathways mediated by rice pi21 gene with partial resistance to Magnaporthe oryzae

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Yu Zhang

2016-12-01

Full Text Available Rice blast disease is one of the most destructive rice diseases worldwide. The pi21 gene confers partial and durable resistance to Magnaporthe oryzae. However, little is known regarding the molecular mechanisms of resistance mediated by the loss-of-function of Pi21. In this study, comparative transcriptome profiling of the Pi21-RNAi transgenic rice line and Nipponbare with M. oryzae infection at different time points (0, 12, 24, 48, and 72 hpi were investigated using RNA sequencing. The results generated 43,222 unique genes mapped to the rice genome. In total, 1,109 differentially expressed genes (DEGs were identified between the Pi21-RNAi line and Nipponbare with M. oryzae infection, with 103, 281, 209, 69, and 678 DEGs at 0, 12, 24, 48, and 72 hpi, respectively. Functional analysis showed that most of the DEGs were involved in metabolism, transport, signaling, and defense. Among the genes assigned to plant–pathogen interaction, we identified 43 receptor kinase genes associated with pathogen-associated molecular pattern recognition and calcium ion influx. The expression levels of brassinolide-insensitive 1, flagellin sensitive 2 and elongation factor Tu receptor, ethylene (ET biosynthesis and signaling genes, were higher in the Pi21-RNAi line than Nipponbare. This suggested that there was a more robust PTI response in Pi21-RNAi plants and that ET signaling was important to rice blast resistance. We also identified 53 transcription factor genes, including WRKY, NAC, DOF, and ERF families that show differential expression between the two genotypes. This study highlights possible candidate genes that may serve a function in the partial rice blast resistance mediated by the loss-of-function of Pi21 and increase our understanding of the molecular mechanisms involved in partial resistance against M. oryzae.

Connective tissue growth factor confers drug resistance in breast cancer through concomitant up-regulation of Bcl-xL and cIAP1.

Science.gov (United States)

Wang, Ming-Yang; Chen, Pai-Sheng; Prakash, Ekambaranellore; Hsu, Hsing-Chih; Huang, Hsin-Yi; Lin, Ming-Tsan; Chang, King-Jen; Kuo, Min-Liang

2009-04-15

Connective tissue growth factor (CTGF) expression is elevated in advanced breast cancer and promotes metastasis. Chemotherapy response is only transient in most metastatic diseases. In the present study, we examined whether CTGF expression could confer drug resistance in human breast cancer. In breast cancer patients who received neoadjuvant chemotherapy, CTGF expression was inversely associated with chemotherapy response. Overexpression of CTGF in MCF7 cells (MCF7/CTGF) enhanced clonogenic ability, cell viability, and resistance to apoptosis on exposure to doxorubicin and paclitaxel. Reducing the CTGF level in MDA-MB-231 (MDA231) cells by antisense CTGF cDNA (MDA231/AS cells) mitigated this drug resistance capacity. CTGF overexpression resulted in resistance to doxorubicin- and paclitaxel-induced apoptosis by up-regulation of Bcl-xL and cellular inhibitor of apoptosis protein 1 (cIAP1). Knockdown of Bcl-xL or cIAP1 with specific small interfering RNAs abolished the CTGF-mediated resistance to apoptosis induced by the chemotherapeutic agents in MCF7/CTGF cells. Inhibition of extracellular signal-regulated kinase (ERK)-1/2 effectively reversed the resistance to apoptosis as well as the up-regulation of Bcl-xL and cIAP1 in MCF7/CTGF cells. A neutralizing antibody against integrin alpha(v)beta(3) significantly attenuated CTGF-mediated ERK1/2 activation and up-regulation of Bcl-xL and cIAP1, indicating that the integrin alpha(v)beta(3)/ERK1/2 signaling pathway is essential for CTGF functions. The Bcl-xL level also correlated with the CTGF level in breast cancer patients. We also found that a COOH-terminal domain peptide from CTGF could exert activities similar to full-length CTGF, in activation of ERK1/2, up-regulation of Bcl-xL/cIAP1, and resistance to apoptosis. We conclude that CTGF expression could confer resistance to chemotherapeutic agents through augmenting a survival pathway through ERK1/2-dependent Bcl-xL/cIAP1 up-regulation.

OPA1 deficiency promotes secretion of FGF21 from muscle that prevents obesity and insulin resistance.

Science.gov (United States)

Pereira, Renata Oliveira; Tadinada, Satya M; Zasadny, Frederick M; Oliveira, Karen Jesus; Pires, Karla Maria Pereira; Olvera, Angela; Jeffers, Jennifer; Souvenir, Rhonda; Mcglauflin, Rose; Seei, Alec; Funari, Trevor; Sesaki, Hiromi; Potthoff, Matthew J; Adams, Christopher M; Anderson, Ethan J; Abel, E Dale

2017-07-14

Mitochondrial dynamics is a conserved process by which mitochondria undergo repeated cycles of fusion and fission, leading to exchange of mitochondrial genetic content, ions, metabolites, and proteins. Here, we examine the role of the mitochondrial fusion protein optic atrophy 1 (OPA1) in differentiated skeletal muscle by reducing OPA1 gene expression in an inducible manner. OPA1 deficiency in young mice results in non-lethal progressive mitochondrial dysfunction and loss of muscle mass. Mutant mice are resistant to age- and diet-induced weight gain and insulin resistance, by mechanisms that involve activation of ER stress and secretion of fibroblast growth factor 21 (FGF21) from skeletal muscle, resulting in increased metabolic rates and improved whole-body insulin sensitivity. OPA1-elicited mitochondrial dysfunction activates an integrated stress response that locally induces muscle atrophy, but via secretion of FGF21 acts distally to modulate whole-body metabolism. © 2017 The Authors.

Normal viability and altered pharmacokinetics in mice lacking mdr1-type (drug-transporting) P-glycoproteins

NARCIS (Netherlands)

Schinkel, A. H.; Mayer, U.; Wagenaar, E.; Mol, C. A.; van Deemter, L.; Smit, J. J.; van der Valk, M. A.; Voordouw, A. C.; Spits, H.; van Tellingen, O.; Zijlmans, J. M.; Fibbe, W. E.; Borst, P.

1997-01-01

The mdr1-type P-glycoproteins (P-gps) confer multidrug resistance to cancer cells by active extrusion of a wide range of drugs from the cell. To study their physiological roles, we have generated mice genetically deficient in the mdr1b gene [mdr1b (-/-) mice] and in both the mdr1a and mdr1b genes

Role of the CipA Scaffoldin Protein in Cellulose Solubilization, as Determined by Targeted Gene Deletion and Complementation in Clostridium thermocellum

Science.gov (United States)

Olson, Daniel G.; Giannone, Richard J.; Hettich, Robert L.

2013-01-01

The CipA scaffoldin protein plays a key role in the Clostridium thermocellum cellulosome. Previous studies have revealed that mutants deficient in binding or solubilizing cellulose also exhibit reduced expression of CipA. To confirm that CipA is, in fact, necessary for rapid solubilization of crystalline cellulose, the gene was deleted from the chromosome using targeted gene deletion technologies. The CipA deletion mutant exhibited a 100-fold reduction in cellulose solubilization rate, although it was eventually able to solubilize 80% of the 5 g/liter cellulose initially present. The deletion mutant was complemented by a copy of cipA expressed from a replicating plasmid. In this strain, Avicelase activity was restored, although the rate was 2-fold lower than that in the wild type and the duration of the lag phase was increased. The cipA coding sequence is located at the beginning of a gene cluster containing several other genes thought to be responsible for the structural organization of the cellulosome, including olpB, orf2p, and olpA. Tandem mass spectrometry revealed a 10-fold reduction in the expression of olpB, which may explain the lower growth rate. This deletion experiment adds further evidence that CipA plays a key role in cellulose solubilization by C. thermocellum, and it raises interesting questions about the differential roles of the anchor scaffoldin proteins OlpB, Orf2p, and SdbA. PMID:23204466

Neofunctionalization of Duplicated P450 Genes Drives the Evolution of Insecticide Resistance in the Brown Planthopper.

Science.gov (United States)

Zimmer, Christoph T; Garrood, William T; Singh, Kumar Saurabh; Randall, Emma; Lueke, Bettina; Gutbrod, Oliver; Matthiesen, Svend; Kohler, Maxie; Nauen, Ralf; Davies, T G Emyr; Bass, Chris

2018-01-22

Gene duplication is a major source of genetic variation that has been shown to underpin the evolution of a wide range of adaptive traits [1, 2]. For example, duplication or amplification of genes encoding detoxification enzymes has been shown to play an important role in the evolution of insecticide resistance [3-5]. In this context, gene duplication performs an adaptive function as a result of its effects on gene dosage and not as a source of functional novelty [3, 6-8]. Here, we show that duplication and neofunctionalization of a cytochrome P450, CYP6ER1, led to the evolution of insecticide resistance in the brown planthopper. Considerable genetic variation was observed in the coding sequence of CYP6ER1 in populations of brown planthopper collected from across Asia, but just two sequence variants are highly overexpressed in resistant strains and metabolize imidacloprid. Both variants are characterized by profound amino-acid alterations in substrate recognition sites, and the introduction of these mutations into a susceptible P450 sequence is sufficient to confer resistance. CYP6ER1 is duplicated in resistant strains with individuals carrying paralogs with and without the gain-of-function mutations. Despite numerical parity in the genome, the susceptible and mutant copies exhibit marked asymmetry in their expression with the resistant paralogs overexpressed. In the primary resistance-conferring CYP6ER1 variant, this results from an extended region of novel sequence upstream of the gene that provides enhanced expression. Our findings illustrate the versatility of gene duplication in providing opportunities for functional and regulatory innovation during the evolution of an adaptive trait. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Correlation between expression of p53, p21/WAF1, and MDM2 proteins and their prognostic significance in primary hepatocellular carcinoma

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Fu Jia

2009-12-01

Full Text Available Abstract Background Tumor Protein p53 (p53, cyclin-dependent kinase inhibitor 1A (p21/WAF1, and murine double minute 2 (MDM2 participate in the regulation of cell growth. Altered expression of these gene products has been found in malignant tumors and has been associated with poor prognosis. Our aim was to investigate the expression of the 3 proteins in hepatocellular carcinoma (HCC and their prognostic significance. Methods We examined p53, p21/WAF1, and MDM2 expression in 181 pairs of HCC tissues and the adjacent hepatic tissues by performing immunohistochemistry and examined the expression of the 3 proteins in 7 pairs of HCC tissues and the adjacent hepatic tissues by using western blot analysis. Results The expression of p53, p21/WAF1, and MDM2 in the HCC tissues was significantly higher than those in the adjacent hepatic tissues (P P = 0.008. A statistical correlation was observed between expression of p53 and p21/WAF1 (R = 0.380, P = 0.000, p53 and MDM2 (R = 0.299, P = 0.000, p21/WAF1 and MDM2 (R = 0.285, P = 0.000 in 181 liver tissues adjacent to the tumor. Patients with a low pathologic grade HCC (I+II had a higher tendency to express p53 on tumor cells than the patients with high pathologic grade HCC (III+IV (P = 0.007. Survival analysis showed that positive p21/WAF1 expression or/and negative MDM2 expression in HCC was a predictor of better survival of patients after tumor resection (P Conclusions The proteins p53, p21/WAF1, and MDM2 were overexpressed in all the HCC cases in this study, and p53 and p21/WAF1 overexpression were positively correlated. The expression of p21/WAF1 and MDM2 can be considered as 2 useful indicators for predicting the prognosis of HCC.

Bmi1 confers resistance to oxidative stress on hematopoietic stem cells.

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Shunsuke Nakamura

Full Text Available The polycomb-group (PcG proteins function as general regulators of stem cells. We previously reported that retrovirus-mediated overexpression of Bmi1, a gene encoding a core component of polycomb repressive complex (PRC 1, maintained self-renewing hematopoietic stem cells (HSCs during long-term culture. However, the effects of overexpression of Bmi1 on HSCs in vivo remained to be precisely addressed.In this study, we generated a mouse line where Bmi1 can be conditionally overexpressed under the control of the endogenous Rosa26 promoter in a hematopoietic cell-specific fashion (Tie2-Cre;R26Stop(FLBmi1. Although overexpression of Bmi1 did not significantly affect steady state hematopoiesis, it promoted expansion of functional HSCs during ex vivo culture and efficiently protected HSCs against loss of self-renewal capacity during serial transplantation. Overexpression of Bmi1 had no effect on DNA damage response triggered by ionizing radiation. In contrast, Tie2-Cre;R26Stop(FLBmi1 HSCs under oxidative stress maintained a multipotent state and generally tolerated oxidative stress better than the control. Unexpectedly, overexpression of Bmi1 had no impact on the level of intracellular reactive oxygen species (ROS.Our findings demonstrate that overexpression of Bmi1 confers resistance to stresses, particularly oxidative stress, onto HSCs. This thereby enhances their regenerative capacity and suggests that Bmi1 is located downstream of ROS signaling and negatively regulated by it.

Transgenic strategies to confer resistance against viruses in rice plants

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Takahide eSasaya

2014-01-01

Full Text Available Rice (Oryza sativa L. is cultivated in more than 100 countries and supports nearly half of the world’s population. Developing efficient methods to control rice viruses is thus an urgent necessity because viruses cause serious losses in rice yield. Most rice viruses are transmitted by insect vectors, notably planthoppers and leafhoppers. Viruliferous insect vectors can disperse their viruses over relatively long distances, and eradication of the viruses is very difficult once they become widespread. Exploitation of natural genetic sources of resistance is one of the most effective approaches to protect crops from virus infection; however, only a few naturally occurring rice genes confer resistance against rice viruses. In an effort to improve control, many investigators are using genetic engineering of rice plants as a potential strategy to control viral diseases. Using viral genes to confer pathogen-derived resistance against crops is a well-established procedure, and the expression of various viral gene products has proved to be effective in preventing or reducing infection by various plant viruses since the 1990s. RNA-interference (RNAi, also known as RNA silencing, is one of the most efficient methods to confer resistance against plant viruses on their respective crops. In this article, we review the recent progress, mainly conducted by our research group, in transgenic strategies to confer resistance against tenuiviruses and reoviruses in rice plants. Our findings also illustrate that not all RNAi constructs against viral RNAs are equally effective in preventing virus infection and that it is important to identify the viral Achilles’ heel gene to target for RNAi attack when engineering plants.

Stable gene transfer of CCR5 and CXCR4 siRNAs by sleeping beauty transposon system to confer HIV-1 resistance

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Akkina Ramesh

2008-07-01

Full Text Available Abstract Background Thus far gene therapy strategies for HIV/AIDS have used either conventional retroviral vectors or lentiviral vectors for gene transfer. Although highly efficient, their use poses a certain degree of risk in terms of viral mediated oncogenesis. Sleeping Beauty (SB transposon system offers a non-viral method of gene transfer to avoid this possible risk. With respect to conferring HIV resistance, stable knock down of HIV-1 coreceptors CCR5 and CXCR4 by the use of lentiviral vector delivered siRNAs has proved to be a promising strategy to protect cells from HIV-1 infection. In the current studies our aim is to evaluate the utility of SB system for stable gene transfer of CCR5 and CXCR4 siRNA genes to derive HIV resistant cells as a first step towards using this system for gene therapy. Results Two well characterized siRNAs against the HIV-1 coreceptors CCR5 and CXCR4 were chosen based on their previous efficacy for the SB transposon gene delivery. The siRNA transgenes were incorporated individually into a modified SB transfer plasmid containing a FACS sortable red fluorescence protein (RFP reporter and a drug selectable neomycin resistance gene. Gene transfer was achieved by co-delivery with a construct expressing a hyperactive transposase (HSB5 into the GHOST-R3/X4/R5 cell line, which expresses the major HIV receptor CD4 and and the co-receptors CCR5 and CXCR4. SB constructs expressing CCR5 or CXCR4 siRNAs were also transfected into MAGI-CCR5 or MAGI-CXCR4 cell lines, respectively. Near complete downregulation of CCR5 and CXCR4 surface expression was observed in transfected cells. During viral challenge with X4-tropic (NL4.3 or R5-tropic (BaL HIV-1 strains, the respective transposed cells showed marked viral resistance. Conclusion SB transposon system can be used to deliver siRNA genes for stable gene transfer. The siRNA genes against HIV-1 coreceptors CCR5 and CXCR4 are able to downregulate the respective cell surface proteins

Cisplatin-resistant lung cancer cell-derived exosomes increase cisplatin resistance of recipient cells in exosomal miR-100-5p-dependent manner.

Science.gov (United States)

Qin, Xiaobing; Yu, Shaorong; Zhou, Leilei; Shi, Meiqi; Hu, Yong; Xu, Xiaoyue; Shen, Bo; Liu, Siwen; Yan, Dali; Feng, Jifeng

2017-01-01

Exosomes derived from lung cancer cells confer cisplatin (DDP) resistance to other cancer cells. However, the underlying mechanism is still unknown. A549 resistance to DDP (A549/DDP) was established. Microarray was used to analyze microRNA (miRNA) expression profiles of A549 cells, A549/DDP cells, A549 exosomes, and A549/DDP exosomes. There was a strong correlation of miRNA profiles between exosomes and their maternal cells. A total of 11 miRNAs were significantly upregulated both in A549/DDP cells compared with A549 cells and in exosomes derived from A549/DDP cells in contrast to exosomes from A549 cells. A total of 31 downregulated miRNAs were also observed. miR-100-5p was the most prominent decreased miRNA in DDP-resistant exosomes compared with the corresponding sensitive ones. Downregulated miR-100-5p was proved to be involved in DDP resistance in A549 cells, and mammalian target of rapamycin (mTOR) expression was reverse regulated by miR-100-5p. Exosomes confer recipient cells' resistance to DDP in an exosomal miR-100-5p-dependent manner with mTOR as its potential target both in vitro and in vivo. Exosomes from DDP-resistant lung cancer cells A549 can alter other lung cancer cells' sensitivity to DDP in exosomal miR-100-5p-dependent manner. Our study provides new insights into the molecular mechanism of DDP resistance in lung cancer.

Aves do Parque Nacional da Serra do Cipó: o Vale do Rio Cipó, Minas Gerais, Brasil The birds of "Parque Nacional da Serra do Cipó": the Rio Cipó valley, Minas Gerais, Brazil

Directory of Open Access Journals (Sweden)

Marcos Rodrigues

2005-06-01

Full Text Available Foi conduzido um levantamento de espécies de aves do Vale do alto Rio Cipó durante o período de maio de 1998 a novembro de 2002. A região está totalmente inserida em uma das unidades de conservação mais importantes do sudeste do Brasil, o Parque Nacional da Serra do Cipó, em Minas Gerais. O método utilizado foi o de observação direta ao longo de 'transectos', captura com redes e identificação a partir do uso de vocalizações. A riqueza de espécies foi estimada usando-se o método de 'jackknife'. Foram registradas 226 espécies de aves pertencentes a 43 famílias. Isso corresponde cerca de 27% das 837 espécies já registradas para o bioma do Cerrado. Foram capturados 2.249 indivíduos num total de 4.486,82 horas-rede, onde foram amostradas 119 espécies pertencentes a 23 famílias. A riqueza foi estimada em 239 ± 5 espécies. Constam nesta lista seis espécies endêmicas do Cerrado: Augastes scutatus (Temminck, 1824 (Trochilidae, Hylocryptus rectirostris (Wied-NeuWied, 1821 (Furnariidae, Antilophia galeata (Lichtenstein, 1832 (Pipridae, Cyanocorax cristatellus (Temminck, 1823 (Corvidae, Charitospiza eucosma (Oberholser, 1905, Saltator atricollis (Vieillot, 1817, e Porphyrospiza caerulescens (Wied-Neuwied, 1830 (Emberizidae. Ocorrem também três espécies quase-ameaçadas de extinção: Sarcoramphus papa (Linnaeus, 1758 (Cathartidae, Cypsnagra hirundinacea (Lesson, 1831 e Charitospiza eucosma (Emberizidae. O Vale do Rio Cipó abriga uma porção significativa da avifauna do Cerrado. Alguns dos habitat encontrados no Vale estão se tornando cada vez mais raros na região do Cerrado de todo o Brasil, como as matas ciliares e o sistema de lagoas temporárias ao longo dos rios. Mesmo as cachoeiras, habitat importante para várias espécies, vêm desaparecendo em outras regiões do Brasil. Nesse sentido, a região do Vale do Rio Cipó dentro Parque consolida um dos seus objetivos que é a conservação da biodiversidade.It is

Therapeutically targeting cyclin D1 in primary tumors arising from loss of Ini1

Science.gov (United States)

Smith, Melissa E.; Cimica, Velasco; Chinni, Srinivasa; Jana, Suman; Koba, Wade; Yang, Zhixia; Fine, Eugene; Zagzag, David; Montagna, Cristina; Kalpana, Ganjam V.

2011-01-01

Rhabdoid tumors (RTs) are rare, highly aggressive pediatric malignancies with poor prognosis and with no standard or effective treatment strategies. RTs are characterized by biallelic inactivation of the INI1 tumor suppressor gene. INI1 directly represses CCND1 and activates cyclin-dependent kinase (cdk) inhibitors p16Ink4a and p21CIP. RTs are exquisitely dependent on cyclin D1 for genesis and survival. To facilitate translation of unique therapeutic strategies, we have used genetically engineered, Ini1+/− mice for therapeutic testing. We found that PET can be used to noninvasively and accurately detect primary tumors in Ini1+/− mice. In a PET-guided longitudinal study, we found that treating Ini1+/− mice bearing primary tumors with the pan-cdk inhibitor flavopiridol resulted in complete and stable regression of some tumors. Other tumors showed resistance to flavopiridol, and one of the resistant tumors overexpressed cyclin D1, more than flavopiridol-sensitive cells. The concentration of flavopiridol used was not sufficient to down-modulate the high level of cyclin D1 and failed to induce cell death in the resistant cells. Furthermore, FISH and PCR analyses indicated that there is aneuploidy and increased CCND1 copy number in resistant cells. These studies indicate that resistance to flavopiridol may be correlated to elevated cyclin D1 levels. Our studies also indicate that Ini1+/− mice are valuable tools for testing unique therapeutic strategies and for understanding mechanisms of drug resistance in tumors that arise owing to loss of Ini1, which is essential for developing effective treatment strategies against these aggressive tumors. PMID:21173237

Overexpression and small molecule-triggered downregulation of CIP2A in lung cancer.

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Liang Ma

Full Text Available Lung cancer is the leading cause of cancer deaths worldwide, with a five-year overall survival rate of only 15%. Cancerous inhibitor of PP2A (CIP2A is a human oncoprotein inhibiting PP2A in many human malignancies. However, whether CIP2A can be a new drug target for lung cancer is largely unclear.Normal and malignant lung tissues were derived from 60 lung cancer patients from southern China. RT-PCR, Western blotting and immunohistochemistry were used to evaluate the expression of CIP2A. We found that among the 60 patients, CIP2A was undetectable or very low in paratumor normal tissues, but was dramatically elevated in tumor samples in 38 (63.3% patients. CIP2A overexpression was associated with cigarette smoking. Silencing CIP2A by siRNA inhibited the proliferation and clonogenic activity of lung cancer cells. Intriguingly, we found a natural compound, rabdocoetsin B which is extracted from a Traditional Chinese Medicinal herb Rabdosia coetsa, could induce down-regulation of CIP2A and inactivation of Akt pathway, and inhibit proliferation and induce apoptosis in a variety of lung cancer cells.Our findings strongly indicate that CIP2A could be an effective target for lung cancer drug development, and the therapeutic potentials of CIP2A-targeting agents warrant further investigation.

Clinical and pathological associations with p53 tumour-suppressor gene mutations and expression of p21WAF1/Cip1 in colorectal carcinoma

NARCIS (Netherlands)

Slebos, R. J.; Baas, I. O.; Clement, M.; Polak, M.; Mulder, J. W.; van den Berg, F. M.; Hamilton, S. R.; Offerhaus, G. J.

1996-01-01

Inactivation of the p53 tumour-suppressor gene is common in a wide variety of human neoplasms. In the majority of cases, single point mutations in the protein-encoding sequence of p53 lead to positive immunohistochemistry (IHC) for the p53 protein, and are accompanied by loss of the wild-type

Neutronic design of the RSG-GAS compact core without CIP

International Nuclear Information System (INIS)

Jati-Susilo; Iman-Kuntoro

2003-01-01

Improvement of the efficiency of reactor operation can be achieved by some ways, such as, the uranium density of the fuel, loading pattern and configuration of core elements. The paper deals with determination of optimal configuration of the compact core with out CIP. Calculations were carried out by means of SRAC-PIJ module for cross section generation and SRAC-ASMBURN for core calculations. The optimal compact core obtained, showed that no-CIP compact core increase highest reactivity value about 1.06 % Δk/k and longest time operation about 1.19 time in the safety criteria that is power peaking factor less then 1.4 and margin control element worth less then value in the first design that -2.2% Δk/k

The role of hypoxia inducible factor-1 alpha in bypassing oncogene-induced senescence.

Directory of Open Access Journals (Sweden)

Mehtap Kilic Eren

Full Text Available Oncogene induced senescence (OIS is a sustained anti-proliferative response acutely induced in primary cells via activation of mitogenic oncogenes such as Ras/BRAF. This mechanism acts as an initial barrier preventing normal cells transformation into malignant cell. Besides oncogenic activation and DNA damage response (DDR, senescence is modulated by a plethora of other factors, and one of the most important one is oxygen tension of the tissue. The aim of this study was to determine the impact of hypoxia on RasV12-induced senescence in human diploid fibroblasts (HDFs. We showed here that hypoxia prevents execution of oncogene induced senescence (OIS, through a strong down-regulation of senescence hallmarks, such as SA- β-galactosidase, H3K9me3, HP1γ, p53, p21CIP1 and p16INK4a in association with induction of hypoxia inducible factor-1α (HIF-1α. In addition, hypoxia also decreased marks of H-RasV12-induced DDR in both cell lines through down-regulation of ATM/ATR, Chk1 and Chk2 phosphorylation as well as decreased γ-H2AX positivity. Utilizing shRNA system targeting HIF-1α we show that HIF-1α is directly involved in down regulation of p53 and its target p21CIP1 but not p16INK4a. In line with this finding we found that knock down of HIF-1α leads to a strong induction of apoptotic response, but not restoration of senescence in Ras expressing HDFs in hypoxia. This indicates that HIF-1α is an important player in early steps of tumorigenesis, leading to suppression of senescence through its negative regulation of p53 and p21CIP1. In our work we describe a mechanism through which hypoxia and specifically HIF-1α preclude cells from maintaining senescence-driven anti proliferative response. These findings indicate the possible mechanism through which hypoxic environment helps premalignant cells to evade impingement of cellular failsafe pathways.

Emergence of Ciprofloxacin-Resistant Salmonella enterica Serovar Typhi in Italy.

Directory of Open Access Journals (Sweden)

Aurora García-Fernández

Full Text Available In developed countries, typhoid fever is often associated with persons who travel to endemic areas or immigrate from them. Typhoid fever is a systemic infection caused by Salmonella enterica serovar Typhi. Because of the emergence of antimicrobial resistance to standard first-line drugs, fluoroquinolones are the drugs of choice. Resistance to ciprofloxacin by this Salmonella serovar represents an emerging public health issue. Two S. enterica ser. Typhi strains resistant to ciprofloxacin (CIP were reported to the Italian surveillance system for foodborne and waterborne diseases (EnterNet-Italia in 2013. The strains were isolated from two Italian tourists upon their arrival from India. A retrospective analysis of 17 other S. enterica ser. Typhi strains isolated in Italy during 2011-2013 was performed to determine their resistance to CIP. For this purpose, we assayed for susceptibility to antimicrobial agents and conducted PCR and nucleotide sequence analyses. Moreover, all strains were typed using pulsed-field gel electrophoresis to evaluate possible clonal relationships. Sixty-eight percent of the S. enterica ser. Typhi strains were resistant to CIP (MICs, 0.125-16 mg/L, and all isolates were negative for determinants of plasmid-mediated quinolone resistance. Analysis of sequences encoding DNA gyrase and topoisomerase IV subunits revealed mutations in gyrA, gyrB, and parC. Thirteen different clonal groups were detected, and the two CIP-resistant strains isolated from the individuals who visited India exhibited the same PFGE pattern. Because of these findings, the emergence of CIP-resistant S. enterica ser. Typhi isolates in Italy deserves attention, and monitoring antibiotic susceptibility is important for efficiently managing cases of typhoid fever.

The electrical resistivity and percolation threshold of MWCNTs/polymer composites filled with a few aligned carbonyl iron particles

Science.gov (United States)

Dong, Shuai; Wang, Xiaojie

2018-03-01

Conductive polymer composites (CPCs) consist of multi-walled carbon nanotubes (MWCNTs), a few carbonyl iron particles (CIPs) and polydimethylsiloxane (PDMS) are fabricated under a moderate magnetic field. The alignment of CIPs will change the structure of MWCNT network, and consequently the electrical properties of CPCs. The volume fraction of CIPs is fixed at 0.08 vol% at which CIPs will not directly participate in electric conduction. The electrical resistivity of CPCs and the changes of resistance versus strain are evaluated at various MWCNT volume fractions. The testing results show that a percolation threshold as low as 0.19 vol% is obtained due to the effect of aligned CIPs, comparing with 0.39 vol% of isotropic MWCNT/CIP/PDMS (prepared without magnetic field). Meanwhile, the anisotropic structure reduces the electrical resistivity by more than 80% when the MWCNT volume fractions is over the percolation threshold.

21st Annual Conference of Ramanujan Mathematical Society

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 11; Issue 4. 21st Annual Conference of Ramanujan Mathematical Society. Information and Announcements Volume 11 Issue 4 April 2006 pp 108-108. Fulltext. Click here to view fulltext PDF. Permanent link:

Anti-S1P Antibody as a Novel Therapeutic Strategy for VEGFR TKI-Resistant Renal Cancer.

Science.gov (United States)

Zhang, Liang; Wang, Xiaoen; Bullock, Andrea J; Callea, Marcella; Shah, Harleen; Song, Jiaxi; Moreno, Kelli; Visentin, Barbara; Deutschman, Douglas; Alsop, David C; Atkins, Michael B; Mier, James W; Signoretti, Sabina; Bhasin, Manoj; Sabbadini, Roger A; Bhatt, Rupal S

2015-04-15

VEGFR2 tyrosine kinase inhibition (TKI) is a valuable treatment approach for patients with metastatic renal cell carcinoma (RCC). However, resistance to treatment is inevitable. Identification of novel targets could lead to better treatment for patients with TKI-naïve or -resistant RCC. In this study, we performed transcriptome analysis of VEGFR TKI-resistant tumors in a murine model and discovered that the SPHK-S1P pathway is upregulated at the time of resistance. We tested sphingosine-1-phosphate (S1P) pathway inhibition using an anti-S1P mAb (sphingomab), in two mouse xenograft models of RCC, and assessed tumor SPHK expression and S1P plasma levels in patients with metastatic RCC. Resistant tumors expressed several hypoxia-regulated genes. The SPHK1 pathway was among the most highly upregulated pathways that accompanied resistance to VEGFR TKI therapy. SPHK1 was expressed in human RCC, and the product of SPHK1 activity, S1P, was elevated in patients with metastatic RCC, suggesting that human RCC behavior could, in part, be due to overproduction of S1P. Sphingomab neutralization of extracellular S1P slowed tumor growth in both mouse models. Mice bearing tumors that had developed resistance to sunitinib treatment also exhibited tumor growth suppression with sphingomab. Sphingomab treatment led to a reduction in tumor blood flow as measured by MRI. Our findings suggest that S1P inhibition may be a novel therapeutic strategy in patients with treatment-naïve RCC and also in the setting of resistance to VEGFR TKI therapy. ©2015 American Association for Cancer Research.

Resistance to Downy Mildew in Lettuce 'La Brillante' is Conferred by Dm50 Gene and Multiple QTL.

Science.gov (United States)

Simko, Ivan; Ochoa, Oswaldo E; Pel, Mathieu A; Tsuchida, Cayla; Font I Forcada, Carolina; Hayes, Ryan J; Truco, Maria-Jose; Antonise, Rudie; Galeano, Carlos H; Michelmore, Richard W

2015-09-01

Many cultivars of lettuce (Lactuca sativa L.) are susceptible to downy mildew, a nearly globally ubiquitous disease caused by Bremia lactucae. We previously determined that Batavia type cultivar 'La Brillante' has a high level of field resistance to the disease in California. Testing of a mapping population developed from a cross between 'Salinas 88' and La Brillante in multiple field and laboratory experiments revealed that at least five loci conferred resistance in La Brillante. The presence of a new dominant resistance gene (designated Dm50) that confers complete resistance to specific isolates was detected in laboratory tests of seedlings inoculated with multiple diverse isolates. Dm50 is located in the major resistance cluster on linkage group 2 that contains at least eight major, dominant Dm genes conferring resistance to downy mildew. However, this Dm gene is ineffective against the isolates of B. lactucae prevalent in the field in California and the Netherlands. A quantitative trait locus (QTL) located at the Dm50 chromosomal region (qDM2.2) was detected, though, when the amount of disease was evaluated a month before plants reached harvest maturity. Four additional QTL for resistance to B. lactucae were identified on linkage groups 4 (qDM4.1 and qDM4.2), 7 (qDM7.1), and 9 (qDM9.2). The largest effect was associated with qDM7.1 (up to 32.9% of the total phenotypic variance) that determined resistance in multiple field experiments. Markers identified in the present study will facilitate introduction of these resistance loci into commercial cultivars of lettuce.

The wheat Lr34 multipathogen resistance gene confers resistance to anthracnose and rust in sorghum.

Science.gov (United States)

Schnippenkoetter, Wendelin; Lo, Clive; Liu, Guoquan; Dibley, Katherine; Chan, Wai Lung; White, Jodie; Milne, Ricky; Zwart, Alexander; Kwong, Eunjung; Keller, Beat; Godwin, Ian; Krattinger, Simon G; Lagudah, Evans

2017-11-01

The ability of the wheat Lr34 multipathogen resistance gene (Lr34res) to function across a wide taxonomic boundary was investigated in transgenic Sorghum bicolor. Increased resistance to sorghum rust and anthracnose disease symptoms following infection with the biotrophic pathogen Puccinia purpurea and the hemibiotroph Colletotrichum sublineolum, respectively, occurred in transgenic plants expressing the Lr34res ABC transporter. Transgenic sorghum lines that highly expressed the wheat Lr34res gene exhibited immunity to sorghum rust compared to the low-expressing single copy Lr34res genotype that conferred partial resistance. Pathogen-induced pigmentation mediated by flavonoid phytoalexins was evident on transgenic sorghum leaves following P. purpurea infection within 24-72 h, which paralleled Lr34res gene expression. Elevated expression of flavone synthase II, flavanone 4-reductase and dihydroflavonol reductase genes which control the biosynthesis of flavonoid phytoalexins characterized the highly expressing Lr34res transgenic lines 24-h post-inoculation with P. purpurea. Metabolite analysis of mesocotyls infected with C. sublineolum showed increased levels of 3-deoxyanthocyanidin metabolites were associated with Lr34res expression, concomitant with reduced symptoms of anthracnose. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

Three new pancreatic cancer susceptibility signals identified on chromosomes 1q32.1, 5p15.33 and 8q24.21

Science.gov (United States)

Zhang, Mingfeng; Wang, Zhaoming; Obazee, Ofure; Jia, Jinping; Childs, Erica J.; Hoskins, Jason; Figlioli, Gisella; Mocci, Evelina; Collins, Irene; Chung, Charles C.; Hautman, Christopher; Arslan, Alan A.; Beane-Freeman, Laura; Bracci, Paige M.; Buring, Julie; Duell, Eric J.; Gallinger, Steven; Giles, Graham G.; Goodman, Gary E.; Goodman, Phyllis J.; Kamineni, Aruna; Kolonel, Laurence N.; Kulke, Matthew H.; Malats, Núria; Olson, Sara H.; Sesso, Howard D.; Visvanathan, Kala; White, Emily; Zheng, Wei; Abnet, Christian C.; Albanes, Demetrius; Andreotti, Gabriella; Brais, Lauren; Bueno-de-Mesquita, H. Bas; Basso, Daniela; Berndt, Sonja I.; Boutron-Ruault, Marie-Christine; Bijlsma, Maarten F.; Brenner, Hermann; Burdette, Laurie; Campa, Daniele; Caporaso, Neil E.; Capurso, Gabriele; Cavestro, Giulia Martina; Cotterchio, Michelle; Costello, Eithne; Elena, Joanne; Boggi, Ugo; Gaziano, J. Michael; Gazouli, Maria; Giovannucci, Edward L.; Goggins, Michael; Gross, Myron; Haiman, Christopher A.; Hassan, Manal; Helzlsouer, Kathy J.; Hu, Nan; Hunter, David J.; Iskierka-Jazdzewska, Elzbieta; Jenab, Mazda; Kaaks, Rudolf; Key, Timothy J.; Khaw, Kay-Tee; Klein, Eric A.; Kogevinas, Manolis; Krogh, Vittorio; Kupcinskas, Juozas; Kurtz, Robert C.; Landi, Maria T.; Landi, Stefano; Marchand, Le Loic; Mambrini, Andrea; Mannisto, Satu; Milne, Roger L.; Neale, Rachel E.; Oberg, Ann L.; Panico, Salvatore; Patel, Alpa V.; Peeters, Petra H. M.; Peters, Ulrike; Pezzilli, Raffaele; Porta, Miquel; Purdue, Mark; Quiros, J. Ramón; Riboli, Elio; Rothman, Nathaniel; Scarpa, Aldo; Scelo, Ghislaine; Shu, Xiao-Ou; Silverman, Debra T.; Soucek, Pavel; Strobel, Oliver; Sund, Malin; Małecka-Panas, Ewa; Taylor, Philip R.; Tavano, Francesca; Travis, Ruth C.; Thornquist, Mark; Tjønneland, Anne; Tobias, Geoffrey S.; Trichopoulos, Dimitrios; Vashist, Yogesh; Vodicka, Pavel; Wactawski-Wende, Jean; Wentzensen, Nicolas; Yu, Herbert; Yu, Kai; Zeleniuch-Jacquotte, Anne; Kooperberg, Charles; Risch, Harvey A.; Jacobs, Eric J.; Li, Donghui; Fuchs, Charles; Hoover, Robert; Hartge, Patricia; Chanock, Stephen J.; Petersen, Gloria M.; Stolzenberg-Solomon, Rachael S.; Wolpin, Brian M.; Kraft, Peter; Klein, Alison P.; Canzian, Federico; Amundadottir, Laufey T.

2016-01-01

Genome-wide association studies (GWAS) have identified common pancreatic cancer susceptibility variants at 13 chromosomal loci in individuals of European descent. To identify new susceptibility variants, we performed imputation based on 1000 Genomes (1000G) Project data and association analysis using 5,107 case and 8,845 control subjects from 27 cohort and case-control studies that participated in the PanScan I-III GWAS. This analysis, in combination with a two-staged replication in an additional 6,076 case and 7,555 control subjects from the PANcreatic Disease ReseArch (PANDoRA) and Pancreatic Cancer Case-Control (PanC4) Consortia uncovered 3 new pancreatic cancer risk signals marked by single nucleotide polymorphisms (SNPs) rs2816938 at chromosome 1q32.1 (per allele odds ratio (OR) = 1.20, P = 4.88×10−15), rs10094872 at 8q24.21 (OR = 1.15, P = 3.22×10−9) and rs35226131 at 5p15.33 (OR = 0.71, P = 1.70×10−8). These SNPs represent independent risk variants at previously identified pancreatic cancer risk loci on chr1q32.1 (NR5A2), chr8q24.21 (MYC) and chr5p15.33 (CLPTM1L-TERT) as per analyses conditioned on previously reported susceptibility variants. We assessed expression of candidate genes at the three risk loci in histologically normal (n = 10) and tumor (n = 8) derived pancreatic tissue samples and observed a marked reduction of NR5A2 expression (chr1q32.1) in the tumors (fold change -7.6, P = 5.7×10−8). This finding was validated in a second set of paired (n = 20) histologically normal and tumor derived pancreatic tissue samples (average fold change for three NR5A2 isoforms -31.3 to -95.7, P = 7.5×10−4-2.0×10−3). Our study has identified new susceptibility variants independently conferring pancreatic cancer risk that merit functional follow-up to identify target genes and explain the underlying biology. PMID:27579533

Targeted sequencing identifies genetic alterations that confer primary resistance to EGFR tyrosine kinase inhibitor (Korean Lung Cancer Consortium).

Science.gov (United States)

Lim, Sun Min; Kim, Hye Ryun; Cho, Eun Kyung; Min, Young Joo; Ahn, Jin Seok; Ahn, Myung-Ju; Park, Keunchil; Cho, Byoung Chul; Lee, Ji-Hyun; Jeong, Hye Cheol; Kim, Eun Kyung; Kim, Joo-Hang

2016-06-14

Non-small-cell lung cancer (NSCLC) patients with activating epidermal growth factor receptor (EGFR) mutations may exhibit primary resistance to EGFR tyrosine kinase inhibitor (TKI). We aimed to examine genomic alterations associated with de novo resistance to gefitinib in a prospective study of NSCLC patients. One-hundred and fifty two patients with activating EGFR mutations were included in this study and 136 patients' tumor sample were available for targeted sequencing of genomic alterations in 22 genes using the Colon and Lung Cancer panel (Ampliseq, Life Technologies). All 132 patients with EGFR mutation were treated with gefitinib for their treatment of advanced NSCLC. Twenty patients showed primary resistance to EGFR TKI, and were classified as non-responders. A total of 543 somatic single-nucleotide variants (498 missense, 13 nonsense) and 32 frameshift insertions/deletions, with a median of 3 mutations per sample. TP53 was most commonly mutated (47%) and mutations in SMAD4 was also common (19%), as well as DDR2 (16%), PIK3CA (15%), STK11 (14%), and BRAF (7%). Genomic mutations in the PI3K/Akt/mTOR pathway were commonly found in non-responders (45%) compared to responders (27%), and they had significantly shorter progression-free survival and overall survival compared to patients without mutations (2.1 vs. 12.8 months, P=0.04, 15.7 vs. not reached, PAkt/mTOR pathway were commonly identified in non-responders and may confer resistance to EGFR TKI. Screening lung adenocarcinoma patients with clinical cancer gene test may aid in selecting out those who show primary resistance to EGFR TKI (NCT01697163).

Occurrence of integrons and resistance genes among sulphonamide-resistant Shigella spp. from Brazil

DEFF Research Database (Denmark)

Peirano, G.; Agersø, Yvonne; Aarestrup, Frank Møller

2005-01-01

Objectives: To determine the occurrence of class 1 and 2 integrons and antimicrobial resistance genes among sulphonamide-resistant Shigella strains isolated in Brazil during 1999-2003. Methods: Sixty-two Shigella (Shigella flexneri, n = 47 and Shigella sonnei, n = 15) were tested against 21...... antimicrobial agents. The presence of integrons classes 1 and 2 and antimicrobial resistance genes was investigated by PCR using specific primers. Results: A total of eight antimicrobial resistance profiles were identified, with the profile of resistance to sulfamethoxazole, trimethoprim, spectinomycin...... of 2214 bp harbouring a gene cassette array conferring resistance to trimethoprim, streptothricin and spectinomycin/streptomycin. The genes coding for resistance to chloramphenicol (catA1), tetracycline [tet(A) and tet(B)] and ampicillin (bla(OXA) and bla(TEM)), were detected in resistant strains...

Neutronic design of the RSG-GAS compact core without CIP

International Nuclear Information System (INIS)

Susilo, Jati; Kuntoro, Iman

2002-01-01

Improvement of the efficiency of reactor operation can be chivvied by some ways, such as, the uranium density of the fuel, loading pattern and configuration of core elements. The paper deals with determination of optimal configuration of the compact core with out CIP. Calculations were carried out by means of SRAC-PIJ module for cross section generation and SRAC-ASMBURN for core calculations. The optimal compact core obtained, showed that no-CIP compact core increase highest reactivity value about 0,84 % Δk/k and longest time operation about 1,19 time in the safety criteria that is power peaking factor less then 1,4 and margin control element worth less then volume in the first design that -2,2% Δk/k

Cytochrome P450s--Their expression, regulation, and role in insecticide resistance.

Science.gov (United States)

Liu, Nannan; Li, Ming; Gong, Youhui; Liu, Feng; Li, Ting

2015-05-01

P450s are known to be critical for the detoxification and/or activation of xenobiotics such as drugs and pesticides and overexpression of P450 genes can significantly affect the disposition of xenobiotics in the tissues of organisms, altering their pharmacological/toxicological effects. In insects, P450s play an important role in detoxifying exogenous compounds such as insecticides and plant toxins and their overexpression can result in increased levels of P450 proteins and P450 activities. This has been associated with enhanced metabolic detoxification of insecticides and has been implicated in the development of insecticide resistance in insects. Multiple P450 genes have been found to be co-overexpressed in individual insect species via several constitutive overexpression and induction mechanisms, which in turn are co-responsible for high levels of insecticide resistance. Many studies have also demonstrated that the transcriptional overexpression of P450 genes in resistant insects is regulated by trans and/or cis regulatory genes/factors. Taken together, these earlier findings suggest not only that insecticide resistance is conferred via multi-resistance P450 genes, but also that it is mediated through the interaction of regulatory genes/factors and resistance genes. This chapter reviews our current understanding of how the molecular mechanisms of P450 interaction/gene regulation govern the development of insecticide resistance in insects and our progress along the road to a comprehensive characterization of P450 detoxification-mediated insecticide resistance. Copyright © 2015 Elsevier Inc. All rights reserved.

Regulation of p21ras activity

DEFF Research Database (Denmark)

Lowy, D R; Zhang, K; DeClue, J E

1992-01-01

The ras genes encode GTP/GDP-binding proteins that participate in mediating mitogenic signals from membrane tyrosine kinases to downstream targets. The activity of p21ras is determined by the concentration of GTP-p21ras, which is tightly regulated by a complex array of positive and negative control...... mechanisms. GAP and NF1 can negatively regulate p21ras activity by stimulating hydrolysis of GTP bound to p21ras. Other cellular factors can positively regulate p21ras by stimulating GDP/GTP exchange....

Geographical gradient of the eIF4E alleles conferring resistance to potyviruses in pea (Pisum) germplasm.

Science.gov (United States)

Konečná, Eva; Šafářová, Dana; Navrátil, Milan; Hanáček, Pavel; Coyne, Clarice; Flavell, Andrew; Vishnyakova, Margarita; Ambrose, Mike; Redden, Robert; Smýkal, Petr

2014-01-01

The eukaryotic translation initiation factor 4E was shown to be involved in resistance against several potyviruses in plants, including pea. We combined our knowledge of pea germplasm diversity with that of the eIF4E gene to identify novel genetic diversity. Germplasm of 2803 pea accessions was screened for eIF4E intron 3 length polymorphism, resulting in the detection of four eIF4E(A-B-C-S) variants, whose distribution was geographically structured. The eIF4E(A) variant conferring resistance to the P1 PSbMV pathotype was found in 53 accessions (1.9%), of which 15 were landraces from India, Afghanistan, Nepal, and 7 were from Ethiopia. A newly discovered variant, eIF4E(B), was present in 328 accessions (11.7%) from Ethiopia (29%), Afghanistan (23%), India (20%), Israel (25%) and China (39%). The eIF4E(C) variant was detected in 91 accessions (3.2% of total) from India (20%), Afghanistan (33%), the Iberian Peninsula (22%) and the Balkans (9.3%). The eIF4E(S) variant for susceptibility predominated as the wild type. Sequencing of 73 samples, identified 34 alleles at the whole gene, 26 at cDNA and 19 protein variants, respectively. Fifteen alleles were virologically tested and 9 alleles (eIF4E(A-1-2-3-4-5-6-7), eIF4E(B-1), eIF4E(C-2)) conferred resistance to the P1 PSbMV pathotype. This work identified novel eIF4E alleles within geographically structured pea germplasm and indicated their independent evolution from the susceptible eIF4E(S1) allele. Despite high variation present in wild Pisum accessions, none of them possessed resistance alleles, supporting a hypothesis of distinct mode of evolution of resistance in wild as opposed to crop species. The Highlands of Central Asia, the northern regions of the Indian subcontinent, Eastern Africa and China were identified as important centers of pea diversity that correspond with the diversity of the pathogen. The series of alleles identified in this study provides the basis to study the co-evolution of potyviruses and the

Physical Localization of a Locus from Agropyron cristatum Conferring Resistance to Stripe Rust in Common Wheat.

Science.gov (United States)

Zhang, Zhi; Song, Liqiang; Han, Haiming; Zhou, Shenghui; Zhang, Jinpeng; Yang, Xinming; Li, Xiuquan; Liu, Weihua; Li, Lihui

2017-11-13

Stripe rust, caused by Puccinia striiformis f. sp. tritici ( Pst ), is one of the most destructive diseases of wheat ( Triticum aestivum L.) worldwide. Agropyron cristatum (L.) Gaertn. (2 n = 28, PPPP), one of the wild relatives of wheat, exhibits resistance to stripe rust. In this study, wheat- A . cristatum 6P disomic addition line 4844-12 also exhibited resistance to stripe rust. To identify the stripe rust resistance locus from A . cristatum 6P, ten translocation lines, five deletion lines and the BC₂F₂ and BC₃F₂ populations of two wheat- A . cristatum 6P whole-arm translocation lines were tested with a mixture of two races of Pst in two sites during 2015-2016 and 2016-2017, being genotyped with genomic in situ hybridization (GISH) and molecular markers. The result indicated that the locus conferring stripe rust resistance was located on the terminal 20% of 6P short arm's length. Twenty-nine 6P-specific sequence-tagged-site (STS) markers mapped on the resistance locus have been acquired, which will be helpful for the fine mapping of the stripe rust resistance locus. The stripe rust-resistant translocation lines were found to carry some favorable agronomic traits, which could facilitate their use in wheat improvement. Collectively, the stripe rust resistance locus from A . cristatum 6P could be a novel resistance source and the screened stripe rust-resistant materials will be valuable for wheat disease breeding.

On fully three-dimensional resistive wall mode and feedback stabilization computations

International Nuclear Information System (INIS)

Strumberger, E.; Merkel, P.; Sempf, M.; Guenter, S.

2008-01-01

Resistive walls, located close to the plasma boundary, reduce the growth rates of external kink modes to resistive time scales. For such slowly growing resistive wall modes, the stabilization by an active feedback system becomes feasible. The fully three-dimensional stability code STARWALL, and the feedback optimization code OPTIM have been developed [P. Merkel and M. Sempf, 21st IAEA Fusion Energy Conference 2006, Chengdu, China (International Atomic Energy Agency, Vienna, 2006, paper TH/P3-8] to compute the growth rates of resistive wall modes in the presence of nonaxisymmetric, multiply connected wall structures and to model the active feedback stabilization of these modes. In order to demonstrate the capabilities of the codes and to study the effect of the toroidal mode coupling caused by multiply connected wall structures, the codes are applied to test equilibria using the resistive wall structures currently under debate for ITER [M. Shimada et al., Nucl. Fusion 47, S1 (2007)] and ASDEX Upgrade [W. Koeppendoerfer et al., Proceedings of the 16th Symposium on Fusion Technology, London, 1990 (Elsevier, Amsterdam, 1991), Vol. 1, p. 208

Mutation of environmental mycobacteria to resist silver nanoparticles also confers resistance to a common antibiotic.

Science.gov (United States)

Larimer, Curtis; Islam, Mohammad Shyful; Ojha, Anil; Nettleship, Ian

2014-08-01

Non-tuberculous mycobacteria are a threat to human health, gaining entry to the body through contaminated water systems, where they form persistent biofilms despite extensive attempts at disinfection. Silver is a natural antibacterial agent and in nanoparticle form activity is increased by a high surface area. Silver nanoparticles (AgNPs) have been used as alternative disinfectants in circulating water systems, washing machines and even clothing. However, nanoparticles, like any other antibiotic that has a pervasive durable presence, carry the risk of creating a resistant population. In this study Mycobacterium smegmatis strain mc(2)155 was cultured in AgNP enriched agar such that only a small population survived. Surviving cultures were isolated and re-exposed to AgNPs and AgNO3 and resistance to silver was compared to a negative control. After only a single exposure, mutant M. smegmatis populations were resistant to AgNPs and AgNO3. Further, the silver resistant mutants were exposed to antibiotics to determine if general resistance had been conferred. The minimum inhibitory concentration of isoniazid was four times higher for silver resistant mutants than for strain mc(2)155. However, core resistance was not conferred to other toxic metal ions. The mutants had lower resistance to CuSO4 and ZnSO4 than the mc(2)155 strain.

HIF-1α inhibition reverses multidrug resistance in colon cancer cells via downregulation of MDR1/P-glycoprotein.

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Jianfang Chen

Full Text Available Multidrug resistance (MDR is one of the major reasons chemotherapy-based treatments fail. Hypoxia is generally associated with tumor chemoresistance. However, the correlation between the heterodimeric hypoxia-inducible factor-1 (HIF-1 and the multidrug resistance (MDR1 gene/transporter P-glycoprotein (P-gp remains unclear. This study aims to explore the molecular mechanisms of reversing colon cancer MDR by focusing on the target gene HIF-1α.A chemotherapeutic sensitivity assay was used to observe the efficiency of MDR reversal in LoVo multicellular spheroids (MCS. The apoptotic level induced by different drugs was examined by flow cytometry (FCM. Binding of HIF-1α to the MDR1 gene promoter was evaluated by Chromatin immunoprecipitation (ChIP. The relationship between HIF-1α/P-gp expression and sensitivity to chemotherapy was analyzed.The sensitivity of LoVo MCS to all four chemotherapy drugs was decreased to varying degrees under hypoxic conditions. After silencing the HIF-1α gene, the sensitivities of LoVo MCS to all four chemotherapy drugs were restored. The apoptotic levels that all the drugs induced were all decreased to various extents in the hypoxic group. After silencing HIF-1α, the apoptosis level induced by all four chemotherapy drugs increased. The expression of HIF-1α and P-gp was significantly enhanced in LoVo MCS after treatment with hypoxia. Inhibiting HIF-1α significantly decreased the expression of MDR1/P-gp mRNA or protein in both the LoVo monolayers and LoVo MCS. The ChIP assay showed that HIF-1α was bound to the MDR1 gene promoter. Advanced colon carcinoma patients with expression of both HIF-1α and P-gp were more resistant to chemotherapy than that with non expression.HIF-1α inhibition reverses multidrug resistance in colon cancer cells via downregulation of MDR1/P-gp. The expression of HIF-1α and MDR1/P-gp can be used as a predictive marker for chemotherapy resistance in colon cancer.

Asclepiasterol, a novel C21 steroidal glycoside derived from Asclepias curassavica, reverses tumor multidrug resistance by down-regulating P-glycoprotein expression.

Science.gov (United States)

Yuan, Wei-Qi; Zhang, Rong-Rong; Wang, Jun; Ma, Yan; Li, Wen-Xue; Jiang, Ren-Wang; Cai, Shao-Hui

2016-05-24

Multidrug resistance (MDR) mediated by P-glycoprotein (P-gp) is a major cause of cancer therapy failure. In this study, we identified a novel C21 steroidal glycoside, asclepiasterol, capable of reversing P-gp-mediated MDR. Asclepiasterol (2.5 and 5.0μM) enhanced the cytotoxity of P-gp substrate anticancer drugs in MCF-7/ADR and HepG-2/ADM cells. MDR cells were more responsive to paclitaxel in the presence of asclepiasterol, and colony formation of MDR cells was only reduced upon treatment with a combination of asclepiasterol and doxorubicin. Consistent with these findings, asclepiasterol treatment increased the intracellular accumulation of doxorubicin and rhodamine 123 (Rh123) in MDR cells. Asclepiasterol decreased expression of P-gp protein without stimulating or suppressing MDR1 mRNA levels. Asclepiasterol-mediated P-gp suppression caused inhibition of ERK1/2 phosphorylation in two MDR cell types, and EGF, an activator of the MAPK/ERK pathway, reversed the P-gp down-regulation, implicating the MAPK/ERK pathway in asclepiasterol-mediated P-gp down-regulation. These results suggest that asclepiasterol could be developed as a modulator for reversing P-gp-mediated MDR in P-gp-overexpressing cancer variants.

Identification of Orch3, a locus controlling dominant resistance to autoimmune orchitis, as kinesin family member 1C.

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Roxana del Rio

Full Text Available Experimental autoimmune orchitis (EAO, the principal model of non-infectious testicular inflammatory disease, can be induced in susceptible mouse strains by immunization with autologous testicular homogenate and appropriate adjuvants. As previously established, the genome of DBA/2J mice encodes genes that are capable of conferring dominant resistance to EAO, while the genome of BALB/cByJ mice does not and they are therefore susceptible to EAO. In a genome scan, we previously identified Orch3 as the major quantitative trait locus controlling dominant resistance to EAO and mapped it to chromosome 11. Here, by utilizing a forward genetic approach, we identified kinesin family member 1C (Kif1c as a positional candidate for Orch3 and, using a transgenic approach, demonstrated that Kif1c is Orch3. Mechanistically, we showed that the resistant Kif1c(D2 allele leads to a reduced antigen-specific T cell proliferative response as a consequence of decreased MHC class II expression by antigen presenting cells, and that the L(578 → P(578 and S(1027 → P(1027 polymorphisms distinguishing the BALB/cByJ and DBA/2J alleles, respectively, can play a role in transcriptional regulation. These findings may provide mechanistic insight into how polymorphism in other kinesins such as KIF21B and KIF5A influence susceptibility and resistance to human autoimmune diseases.

21st International Conference on Few-Body Problems in Physics

CERN Document Server

2015-01-01

The 21st International Conference on Few-Body Problems in Physics (FB21) will take place at the Crowne Plaza Chicago Metro Downtown Hotel in the West Loop area of Chicago, Illinois, USA, from May 18th to 22nd, 2015. The first conference of this series took place in London in 1959 and subsequent meetings were held in Brela (1967), Birmingham (1969), Budapest (1971), Los Angeles (1972), Laval (1974), Delhi (1976), Graz (1978), Eugene (1980), Karlsruhe (1983), Sendai (1986), Vancouver (1989), Adelaide (1992), Williamsburg (1994), Groningen (1997), Taipei (2000), Durham (2003),Santos (2006),Bonn (2009),and Fukuoka (2012) see also "History". FB21 will be conducted with the principles passed by the General Assembly in 2008. In particular, no bona fide scientist will be excluded from participation on the grounds of national origin, nationality, or political considerations unrelated to science.

Nitric oxide induces thioredoxin-1 nuclear translocation: Possible association with the p21Ras survival pathway

International Nuclear Information System (INIS)

Arai, Roberto J.; Masutani, H.; Yodoi, J.; Debbas, V.; Laurindo, Francisco R.; Stern, A.; Monteiro, Hugo P.

2006-01-01

One of the major redox-regulating molecules with thiol reducing activity is thioredoxin-1 (TRX-1). TRX-1 is a multifunctional protein that exists in the extracellular millieu, cytoplasm, and nucleus, and has a distinct role in each environment. It is well known that TRX-1 promptly migrates to the nuclear compartment in cells exposed to oxidants. However, the intracellular location of TRX-1 in cells exposed to nitrosothiols has not been investigated. Here, we demonstrated that the exposure of HeLa cells to increasing concentrations of the nitrosothiol S-nitroso-N-acetylpenicillamine (SNAP) promoted TRX-1 nuclear accumulation. The SNAP-induced TRX-1 translocation to the nucleus was inhibited by FPTIII, a selective inhibitor of p21Ras. Furthermore, TRX-1 migration was attenuated in cells stably transfected with NO insensitive p21Ras (p21 RasC118S ). Downstream to p21Ras, the MAP Kinases ERK1/2 were activated by SNAP under conditions that promote TRX-1 nuclear translocation. Inhibition of MEK prevented SNAP-stimulated ERK1/2 activation and TRX-1 nuclear migration. In addition, cells treated with p21Ras or MEK inhibitor showed increased susceptibility to cell death induced by SNAP. In conclusion, our observations suggest that the nuclear translocation of TRX-1 is induced by SNAP involving p21Ras survival pathway

p21 promotes oncolytic adenoviral activity in ovarian cancer and is a potential biomarker

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Lockley Michelle

2010-07-01

Full Text Available Abstract The oncolytic adenovirus dl922-947 replicates selectively within and lyses cells with a dysregulated Rb pathway, a finding seen in > 90% human cancers. dl922-947 is more potent than wild type adenovirus and the E1B-deletion mutant dl1520 (Onyx-015. We wished to determine which host cell factors influence cytotoxicity. SV40 large T-transformed MRC5-VA cells are 3-logs more sensitive to dl922-947 than isogenic parental MRC5 cells, confirming that an abnormal G1/S checkpoint increases viral efficacy. The sensitivity of ovarian cancer cells to dl922-947 varied widely: IC50 values ranged from 51 (SKOV3ip1 to 0.03 pfu/cell (TOV21G. Cells sensitive to dl922-947 had higher S phase populations and supported earlier E1A expression. Cytotoxicity correlated poorly with both infectivity and replication, but well with expression of p21 by microarray and western blot analyses. Matched p21+/+ and -/- Hct116 cells confirmed that p21 influences dl922-947 activity in vitro and in vivo. siRNA-mediated p21 knockdown in sensitive TOV21G cells decreases E1A expression and viral cytotoxicity, whilst expression of p21 in resistant A2780CP cells increases virus activity in vitro and in intraperitoneal xenografts. These results highlight that host cell factors beyond simple infectivity can influence the efficacy of oncolytic adenoviruses. p21 expression may be an important biomarker of response in clinical trials.

Resistance to nitrofurantoin and UV-irradiation in recA; uvrA; and uvrA, lexA, Escherichia coli mutants conferred by an R-plasmid from an Escherichia coli clinical isolate

Energy Technology Data Exchange (ETDEWEB)

Obaseiki-Ebor, E.E. (Univ. of Benin, Benin City (Nigeria). Faculty of Pharmacy, Dept. of Pharmaceutical Microbiology)

1984-01-01

There have been some reports of R-plasmids conferring nitrofuran resistance by decreasing the reduction of nitrofurantoin. The mechanism by which these R-plasmids mediate nitrofurantoin resistance is still not properly understood. Since DNA repair mutants are very sensitive to nitrofurantoin, it was therefore of interest to see whether R-plasmids conferring nitrofurantoin resistance affected the nitrofurantoin sensitivity of recA; uvrA and uvrA, lexA strains of E. coli K-12. Protection against UV-irradiation was also estimated. The experiments showed that the nitrofurantoin resistance conferred by R-plasmid pBN105 was not due to defective nitrofurantoin reduction or altered permeability of the cell. Because it is known that repair-deficient bacteria have increased susceptibility to nitrofurantoin, it may be suggested that the mechanisms of UV and nitrofurantoin protection conferred by pBN105 to the DNA repair mutant strains are related.

Resistance to nitrofurantoin and UV-irradiation in recA; uvrA; and uvrA, lexA, Escherichia coli mutants conferred by an R-plasmid from an Escherichia coli clinical isolate

International Nuclear Information System (INIS)

Obaseiki-Ebor, E.E.

1984-01-01

There have been some reports of R-plasmids conferring nitrofuran resistance by decreasing the reduction of nitrofurantoin. The mechanism by which these R-plasmids mediate nitrofurantoin resistance is still not properly understood. Since DNA repair mutants are very sensitive to nitrofurantoin, it was therefore of interest to see whether R-plasmids conferring nitrofurantoin resistance affected the nitrofurantoin sensitivity of recA; uvrA and uvrA, lexA strains of E. coli K-12. Protection against UV-irradiation was also estimated. The experiments showed that the nitrofurantoin resistance conferred by R-plasmid pBN105 was not due to defective nitrofurantoin reduction or altered permeability of the cell. Because it is known that repair-deficient bacteria have increased susceptibility to nitrofurantoin, it may be suggested that the mechanisms of UV and nitrofurantoin protection conferred by pBN105 to the DNA repair mutant strains are related. (Auth.)

SH1 leaf rust and bacterial halo blight coffee resistances are genetically independent

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Lucas Mateus Rivero Rodrigues

Full Text Available ABSTRACT Coffee resistance to Pseudomonas syringae pv. garcae has been associated to pleiotropic effect of SH1 allele, present in coffee plants resistant to certain races of Hemileia vastatrix, the causal agent of leaf rust, or genetic linkage between resistance alleles to both pathogens. To validate this hypothesis, 63 coffee plants in F2 generation were evaluated for resistance to 2 isolates of H. vastatrix carriers of alleles, respectively, v2, v5 (isolate I/2015 and v1; v2; v5 (isolate II/2015 with the objective to confirm presence of SH1 allele in resistant plants to isolate I/2015. The same coffee plants were evaluated for resistance to a mixture of P. syringae pv. garcae strains highly pathogenic to coffee. Results showed that, among F2 coffee allele SH1 carriers, resistant to isolate I/2015, resistant and susceptible plants to bacterial halo blight were found; the same segregation occurs between F2 homozygous for SH1 allele, susceptible to the same isolate (I/2015 of H. vastatrix. Results also indicate that there is no pleiotropic effect of gene or allele SH1 connection between genes conferring resistance to leaf rust caused by H. vastatrix and bacterial halo blight caused by P. syringae pv. garcae.

Arecoline-induced phosphorylated p53 and p21(WAF1) protein expression is dependent on ATM/ATR and phosphatidylinositol-3-kinase in clone-9 cells.

Science.gov (United States)

Chou, Wen-Wen; Guh, Jinn-Yuh; Tsai, Jung-Fa; Hwang, Chi-Ching; Chiou, Shean-Jaw; Chuang, Lea-Yea

2009-06-01

Betel-quid use is associated with liver cancer whereas its constituent arecoline is cytotoxic, genotoxic, and induces p53-dependent p21(WAF1) protein expression in Clone-9 cells (rat hepatocytes). The ataxia telangiectasia mutated (ATM)/rad3-related (ATR)-p53-p21(WAF1) and the phosphatidylinositol-3-kinase (PI3K)-mammalian target of rapamycin (mTOR) pathways are involved in the DNA damage response and the pathogenesis of cancers. Thus, we studied the role of ATM/ATR and PI3K in arecoline-induced p53 and p21(WAF1) protein expression in Clone-9 cells. We found that arecoline (0.5 mM) activated the ATM/ATR kinase at 30 min. The arecoline-activated ATM/ATR substrate contained p-p53Ser15. Moreover, arecoline only increased the levels of the p-p53Ser6, p-p53Ser15, and p-p53Ser392 phosphorylated p53 isoforms among the known isoforms. ATM shRNA attenuated arecoline-induced p-p53Ser15 and p21(WAF1) at 24 h. Arecoline (0.5 mM) increased phosphorylation levels of p-AktSer473 and p-mTORSer2448 at 30-60 min. Dominant-negative PI3K plasmids attenuated arecoline-induced p21(WAF1), but not p-p53Ser15, at 24 h. Rapamycin attenuated arecoline-induced phosphrylated p-p53Ser15, but not p21(WAF1), at 24 h. ATM shRNA, but not dominant-negative PI3K plasmids, attenuated arecoline-induced p21(WAF1) gene transcription. We conclude that arecoline activates the ATM/ATR-p53-p21(WAF1) and the PI3K/Akt-mTOR-p53 pathways in Clone-9 cells. Arecoline-induced phosphorylated p-p53Ser15 expression is dependent on ATM whereas arecoline-induced p21(WAF1) protein expression is dependent on ATM and PI3K. Moreover, p21(WAF1) gene is transcriptionally induced by arecoline-activated ATM. (c) 2009 Wiley-Liss, Inc.

The 1p-encoded protein stathmin and resistance of malignant gliomas to nitrosoureas.

Science.gov (United States)

Ngo, Teri-T B; Peng, Tien; Liang, Xing-Jie; Akeju, Oluwaseun; Pastorino, Sandra; Zhang, Wei; Kotliarov, Yuri; Zenklusen, Jean C; Fine, Howard A; Maric, Dragan; Wen, Patrick Y; De Girolami, Umberto; Black, Peter McL; Wu, Wells W; Shen, Rong-Fong; Jeffries, Neal O; Kang, Dong-Won; Park, John K

2007-04-18

Malignant gliomas are generally resistant to all conventional therapies. Notable exceptions are anaplastic oligodendrogliomas with loss of heterozygosity on chromosome 1p (1p+/-). Patients with 1p+/- anaplastic oligodendroglioma frequently respond to procarbazine, 1-(2-chloroethyl)-3-cyclohexyl-l-nitrosourea, and vincristine. Because the underlying biologic basis for this clinical finding is unclear, we evaluated differentially expressed 1p-encoded proteins in 1p+/- and 1p+/+ malignant glioma cell lines and then examined whether their expression was associated with outcome of patients with anaplastic oligodendroglioma. We used a comparative proteomic screen of A172 (1p+/-) and U251 (1p+/+) malignant glioma cell lines to identify differentially expressed 1p-encoded proteins, including stathmin, a microtubule-associated protein. 1p+/- and 1p+/+ anaplastic oligodendroglioma specimens from 24 patients were assessed for stathmin expression by immunohistochemistry. The relationship between stathmin expression and clinical outcome was assessed with Kaplan-Meier analyses. RNA inhibition and cDNA transfection experiments tested effects of stathmin under- and overexpression, respectively, on the in vitro and in vivo resistance of malignant glioma cells to treatment with nitrosourea. For in vivo resistance studies, 36 mice with intracranial and 16 mice with subcutaneous xenograft tumor implants were used (one tumor per mouse). Flow cytometry was used for cell cycle analysis. Immunoblotting was used to assess protein expression. All statistical tests were two-sided. Decreased stathmin expression in tumors was statistically significantly associated with loss of heterozygosity in 1p (Pnitrosourea-treated mice carrying xenograft tumors. Median survival of mice with stathmin+/- tumors was 95 days (95% CI = 68.7 to 121.3 days) and that of mice with stathmin+/+ tumors was 64 days (95% CI = 58.2 to 69.8 days) (difference = 31 days, 95% CI = 4.1 to 57.9 days; PNitrosoureas induced

Proceedings 21. International Conference on Applied Physics of Condensed Matter and of the Scientific Conference Advanced Fast Reactors

International Nuclear Information System (INIS)

Vajda, J.; Jamnicky, I.

2015-01-01

The 21. International Conference on Applied Physics of Condensed Matter was held on 24-26 June, 2015 on Strbske Pleso, Strba, Slovakia. The Scientific Conference the Advanced Fast Reactors was part of the 21 st International Conference on APCOM 2015. The specialists discussed various aspects of modern problems in: Physical properties and structural aspects of solid materials and their influencing; Advanced fast reactors; Physical properties and structural aspects of solid materials and their influencing; Nuclear science and technology, influence of irradiation on physical properties of materials, radiation detection; Computational physics and theory of physical properties of matter; interdisciplinary physics of condensed matter; Nuclear science and technology, influence of irradiation on physical properties of materials, radiation detection; Optical phenomena in materials, photovoltaics and photonics, new principles in sensors and detection methods. Fifty seven contributions relevant of INIS interest has been inputted to INIS.

Physical structure and genetic expression of the sulfonamide-resistance plasmid pLS80 and its derivatives in Streptococcus pneumoniae and Bacillus subtilis

Energy Technology Data Exchange (ETDEWEB)

Lopez, P.; Espinosa, M.; Lacks, S.A.

1984-01-01

The 10-kb chromosomal fragment of Streptococcus pneumoniae cloned in pLS80 contains the sul-d allele of the pneumococcal gene for dihydropteroate synthase. As a single copy in the chromosome this allele confers resistance to sulfanilamide at 0.2 mg/ml; in the multicopy plasmid it confers resistance to 2.0 mg/ml. The sul-d mutation was mapped by restriction analysis to a 0.4-kb region. A spontaneous deletion beginning approx. 1.5 kb to the right of the sul-d mutation prevented gene function, possibly by removing a promoter. This region could be restored by chromosomal facilitation and be demonstrated in the plasmid by selection for sulfonamide resistance. Under selection for a vector marker, tetracycline resistance, only the deleted plasmid was detectable, apparently as a result of plasmid segregation and the advantageous growth rates of cells with smaller plasmids. When such cells were selected for sulfonamide resistance, the deleted region returned to the plasmid, presumably by equilibration between the chromosome and the plasmid pool, to give a low frequency (approx. 10/sup -3/) of cells resistant to sulfanilamide at 2.0 mg/ml. Models for the mechanisms of chromosomal facilitation and equilibration are proposed. Several derivatives of pLS80 could be transferred to Bacillus subtilis, where they conferred resistance to sulfanilamide at 2 mg/ml, thereby demonstrating cross-species expression of the pneumococcal gene. Transfer of the plasmids to B. subtilis gave rise to large deletions to the left of the sul-d marker, but these deletions did not interfere with the sul-d gene function. Restriction maps of pLS80 and its variously deleted derivatives are presented.

Mapping of novel powdery mildew resistance gene(s) from Agropyron cristatum chromosome 2P.

Science.gov (United States)

Li, Huanhuan; Jiang, Bo; Wang, Jingchang; Lu, Yuqing; Zhang, Jinpeng; Pan, Cuili; Yang, Xinming; Li, Xiuquan; Liu, Weihua; Li, Lihui

2017-01-01

A physical map of Agropyron cristatum 2P chromosome was constructed for the first time and the novel powdery mildew resistance gene(s) from chromosome 2P was(were) also mapped. Agropyron cristatum (L.) Gaertn. (2n = 28, PPPP), a wild relative of common wheat, is highly resistant to powdery mildew. Previous studies showed that wheat-A. cristatum 2P disomic addition line II-9-3 displayed high resistance to powdery mildew, and the resistance was attributable to A. cristatum chromosome 2P. To utilize and physically map the powdery mildew resistance gene(s), 15 wheat-A. cristatum 2P translocation lines and three A. cristatum 2P deletion lines with different chromosomal segment sizes, obtained from II-9-3 using 60 Co-γ ray irradiation, were characterized using cytogenetic and molecular marker analysis. A. cristatum 2P chromosomal segments in the translocations were translocated to different wheat chromosomes, including 1A, 4A, 5A, 6A, 7A, 1B, 2B, 3B, 7B, 3D, 4D, and 6D. A physical map of the 2P chromosome was constructed with 82 STS markers, consisting of nine bins with 34 markers on 2PS and eight bins with 48 markers on 2PL. The BC 1 F 2 populations of seven wheat-A. cristatum 2P translocation lines (2PT-3, 2PT-4, 2PT-5, 2PT-6, 2PT-8, 2PT-9, and 2PT-10) were developed by self-pollination, tested with powdery mildew and genotyped with 2P-specific STS markers. From these results, the gene(s) conferring powdery mildew resistance was(were) located on 2PL bin FL 0.66-0.86 and 19 2P-specific markers were identified in this bin. Moreover, two new powdery mildew-resistant translocation lines (2PT-4 and 2PT-5) with small 2PL chromosome segments were obtained. The newly developed wheat lines with powdery mildew resistance and the closely linked molecular markers will be valuable for wheat disease breeding in the future.

Protective Effect of Ginsenoside Rg1 on Hematopoietic Stem/Progenitor Cells through Attenuating Oxidative Stress and the Wnt/β-Catenin Signaling Pathway in a Mouse Model of d-Galactose-induced Aging.

Science.gov (United States)

Li, Jing; Cai, Dachuan; Yao, Xin; Zhang, Yanyan; Chen, Linbo; Jing, Pengwei; Wang, Lu; Wang, Yaping

2016-06-09

Stem cell senescence is an important and current hypothesis accounting for organismal aging, especially the hematopoietic stem cell (HSC). Ginsenoside Rg1 is the main active pharmaceutical ingredient of ginseng, which is a traditional Chinese medicine. This study explored the protective effect of ginsenoside Rg1 on Sca-1⁺ hematopoietic stem/progenitor cells (HSC/HPCs) in a mouse model of d-galactose-induced aging. The mimetic aging mouse model was induced by continuous injection of d-gal for 42 days, and the C57BL/6 mice were respectively treated with ginsenoside Rg1, Vitamin E or normal saline after 7 days of d-gal injection. Compared with those in the d-gal administration alone group, ginsenoside Rg1 protected Sca-1⁺ HSC/HPCs by decreasing SA-β-Gal and enhancing the colony forming unit-mixture (CFU-Mix), and adjusting oxidative stress indices like reactive oxygen species (ROS), total anti-oxidant (T-AOC), superoxide dismutase (SOD), glutathione peroxidase (GSH-px) and malondialdehyde (MDA). In addition, ginsenoside Rg1 decreased β-catenin and c-Myc mRNA expression and enhanced the phosphorylation of GSK-3β. Moreover, ginsenoside Rg1 down-regulated advanced glycation end products (AGEs), 4-hydroxynonenal (4-HNE), phospho-histone H2A.X (r-H2A.X), 8-OHdG, p16(Ink4a), Rb, p21(Cip1/Waf1) and p53 in senescent Sca-1⁺ HSC/HPCs. Our findings indicated that ginsenoside Rg1 can improve the resistance of Sca-1⁺ HSC/HPCs in a mouse model of d-galactose-induced aging through the suppression of oxidative stress and excessive activation of the Wnt/β-catenin signaling pathway, and reduction of DNA damage response, p16(Ink4a)-Rb and p53-p21(Cip1/Waf1) signaling.

75 FR 66752 - Transmission Vegetation Management Practices; Supplemental Notice of Technical Conference

Science.gov (United States)

2010-10-29

... Vegetation Management Practices; Supplemental Notice of Technical Conference October 21, 2010. On October 5... Vegetation Management Practices would be held on Tuesday, October 26, from 1 p.m. to 5 p.m. This staff-led... . Kimberly D. Bose, Secretary. Technical Conference on Transmission Vegetation Management Practices Docket No...

BRCA1 Expression is an Important Biomarker for Chemosensitivity: Suppression of BRCA1 Increases the Apoptosis via Up-regulation of p53 and p21 During Cisplatin Treatment in Ovarian Cancer Cells

Directory of Open Access Journals (Sweden)

Ikuo Konishi

2006-01-01

Full Text Available BRCA1 is a tumor suppressor which plays a crucial role in the repair of DNA double-strand breaks, and its abnormality is responsible for hereditary ovarian cancer syndrome. It has recently been reported that reduced expression of BRCA1 is also common in sporadic ovarian carcinoma via its promoter hypermethylation, and that ovarian carcinoma patients negative for BRCA1 expression showed favorable prognosis. To address if BRCA1 expression plays a role in the chemotherapeutic response, we analyzed the effect of BRCA1 suppression on the sensitivity to cisplatin and paclitaxel in ovarian cancer cells. Specific siRNA for BRCA1 gene was transfected into 3 ovarian cancer cell lines with various p53 status. Reduced expression of BRCA1 by transfection of BRCA1-siRNA resulted in a 5.3-fold increase in sensitivity to cisplatin in p53-wild A2780 cells, but not in p53-mutated A2780/CDDP and p53-deleted SKOV3 cells. Regarding the sensitivity to paclitaxel, BRCA1 suppression caused no significant changes in all the 3 cell lines. For ionizing radiation sensitivity, BRCA1 suppression also showed a significant higher sensitivity in A2780 cells. Growth curve and cell cycle analyses showed no signifi cant differences between BRCA1-siRNA-transfected A2780 cells and control cells. However, cisplatin treatment under suppression of BRCA1 showed a significantly increased apoptosis along with up-regulation of p53 and p21 in A2780 cells. Accordingly, reduced expression of BRCA1 enhances the cisplatin sensitivity and apoptosis via up-regulation of p53 and p21, but does not affect the paclitaxel sensitivity. Expression of BRCA1 might be an important biomarker for cisplatin resistance in ovarian carcinoma.

Evodiamine selectively targets cancer stem-like cells through the p53-p21-Rb pathway

International Nuclear Information System (INIS)

Han, Seula; Woo, Jong Kyu; Jung, Yuchae; Jeong, Dawoon; Kang, Minsook; Yoo, Young-Ji; Lee, Hani; Oh, Seung Hyun; Ryu, Jae-Ha; Kim, Woo-Young

2016-01-01

In spite of the recent improvements, the resistance to chemotherapy/radiotherapy followed by relapse is the main hurdle for the successful treatment of breast cancer, a leading cause of death in women. A small population of breast cancer cells that have stem-like characteristics (cancer stem-like cells; CSLC) may contribute to this resistance and relapse. Here, we report on a component of a traditional Chinese medicine, evodiamine, which selectively targets CSLC of breast cancer cell lines MCF7 and MDAMB 231 at a concentration that does show a little or no cytotoxic effect on bulk cancer cells. While evodiamine caused the accumulation of bulk cancer cells at the G2/M phase, it did not hold CSLC in a specific cell cycle phase but instead, selectively killed CSLC. This was not due to the culture of CSLC in suspension or without FBS. A proteomic analysis and western blotting revealed that evodiamine changed the expression of cell cycle regulating molecules more efficiently in CSLC cells than in bulk cancer cells. Surprisingly, evodiamine selectively activated p53 and p21 and decreased inactive Rb, the master molecules in G1/S checkpoint. These data collectively suggest a novel mechanism involving CSLC-specific targeting by evodiamine and its possible use to the therapy of breast cancer. - Highlights: • Evodiamine selectively kills breast cancer stem like cells at G1 phase. • Evodiamine utilizes different mechanism of cell cycle modulation in CSLC and in bulk cancer cells. • Evodiamine activate the p53, p21 and Rb pathway.

Evodiamine selectively targets cancer stem-like cells through the p53-p21-Rb pathway

Energy Technology Data Exchange (ETDEWEB)

Han, Seula [The Research Center for Cell Fate Control, College of Pharmacy, Sookmyung Women' s University, Seoul (Korea, Republic of); Woo, Jong Kyu [College of Pharmacy, Gachon University, Incheon (Korea, Republic of); Jung, Yuchae; Jeong, Dawoon; Kang, Minsook; Yoo, Young-Ji; Lee, Hani [The Research Center for Cell Fate Control, College of Pharmacy, Sookmyung Women' s University, Seoul (Korea, Republic of); Oh, Seung Hyun [College of Pharmacy, Gachon University, Incheon (Korea, Republic of); Ryu, Jae-Ha [The Research Center for Cell Fate Control, College of Pharmacy, Sookmyung Women' s University, Seoul (Korea, Republic of); Kim, Woo-Young, E-mail: wykim@sookmyung.ac.kr [The Research Center for Cell Fate Control, College of Pharmacy, Sookmyung Women' s University, Seoul (Korea, Republic of)

2016-01-22

In spite of the recent improvements, the resistance to chemotherapy/radiotherapy followed by relapse is the main hurdle for the successful treatment of breast cancer, a leading cause of death in women. A small population of breast cancer cells that have stem-like characteristics (cancer stem-like cells; CSLC) may contribute to this resistance and relapse. Here, we report on a component of a traditional Chinese medicine, evodiamine, which selectively targets CSLC of breast cancer cell lines MCF7 and MDAMB 231 at a concentration that does show a little or no cytotoxic effect on bulk cancer cells. While evodiamine caused the accumulation of bulk cancer cells at the G2/M phase, it did not hold CSLC in a specific cell cycle phase but instead, selectively killed CSLC. This was not due to the culture of CSLC in suspension or without FBS. A proteomic analysis and western blotting revealed that evodiamine changed the expression of cell cycle regulating molecules more efficiently in CSLC cells than in bulk cancer cells. Surprisingly, evodiamine selectively activated p53 and p21 and decreased inactive Rb, the master molecules in G1/S checkpoint. These data collectively suggest a novel mechanism involving CSLC-specific targeting by evodiamine and its possible use to the therapy of breast cancer. - Highlights: • Evodiamine selectively kills breast cancer stem like cells at G1 phase. • Evodiamine utilizes different mechanism of cell cycle modulation in CSLC and in bulk cancer cells. • Evodiamine activate the p53, p21 and Rb pathway.

Broad-Host-Range IncP-1 plasmids and their resistance potential

Directory of Open Access Journals (Sweden)

Magdalena ePopowska

2013-03-01

Full Text Available The plasmids of the incompatibility group IncP-1, also called IncP, as extrachromosomal genetic elements can transfer and replicate virtually in all Gram-negative bacteria. They are composed of backbone genes that encode a variety of essential functions and accessory genes that have implications for human health and environmental bioremediation. Broad-host-range IncP plasmids are known to spread genes between distinct phylogenetic groups of bacteria. These genes often code for resistances to a broad spectrum of antibiotics, heavy metals and quaternary ammonium compounds used as disinfectants. The backbone of these plasmids carries modules that enable them to effectively replicate, move to a new host via conjugative transfer and to be stably maintained in bacterial cells. The adaptive, resistance and virulence genes are mainly located on mobile genetic elements integrated between the functional plasmid backbone modules. Environmental studies have demonstrated the wide distribution of IncP-like replicons in manure, soils and wastewater treatment plants. They also are present in strains of pathogenic or opportunistic bacteria, which can be a cause for concern, because they may encode multiresistance. Their broad distribution suggests that IncP plasmids play a crucial role in bacterial adaptation by utilizing horizontal gene transfer. This review summarizes the variety of genetic information and physiological functions carried by IncP plasmids, which can contribute to the spread of antibiotic and heavy metal resistance while also mediating the process of bioremediation of pollutants. Due to the location of the resistance genes on plasmids with a broad host range and the presence of transposons carrying these genes it seems that the spread of these genes would be possible and quite hazardous in infection control. Future studies are required to determine the level of risk of the spread of resistance genes located on these plasmids.

Molecular and functional characterization of CYP6BQ23, a cytochrome P450 conferring resistance to pyrethroids in European populations of pollen beetle, Meligethes aeneus.

Science.gov (United States)

Zimmer, Christoph T; Bass, Chris; Williamson, Martin S; Kaussmann, Martin; Wölfel, Katharina; Gutbrod, Oliver; Nauen, Ralf

2014-02-01

The pollen beetle (Meligethes aeneus F.) is widespread throughout much of Europe where it is a major coleopteran pest of oilseed rape (Brassica napus). The reliance on synthetic insecticides for control, particularly the pyrethroid class, has led to the development of populations with high levels of resistance. Resistance to pyrethroids is now widespread throughout Europe and is thought to be mediated by enhanced detoxification by cytochrome P450ś and/or mutation of the pyrethroid target-site, the voltage-gated sodium channel. However, in the case of cytochrome P450 mediated detoxification, the specific enzyme(s) involved has (have) not yet been identified. In this study a degenerate PCR approach was used to identify ten partial P450 gene sequences from pollen beetle. Quantitative PCR was then used to examine the level of expression of these genes in a range of pollen beetle populations that showed differing levels of resistance to pyrethroids in bioassays. The study revealed a single P450 gene, CYP6BQ23, which is significantly and highly overexpressed (up to ∼900-fold) in adults and larvae of pyrethroid resistant strains compared to susceptible strains. CYP6BQ23 overexpression is significantly correlated with both the level of resistance and with the rate of deltamethrin metabolism in microsomal preparations of these populations. Functional recombinant expression of full length CYP6BQ23 along with cytochrome P450 reductase in an insect (Sf9) cell line showed that it is able to efficiently metabolise deltamethrin to 4-hydroxy deltamethrin. Furthermore we demonstrated by detection of 4-hydroxy tau-fluvalinate using ESI-TOF MS/MS that functionally expressed CYP6BQ23 also metabolizes tau-fluvalinate. A protein model was generated and subsequent docking simulations revealed the predicted substrate-binding mode of both deltamethrin and tau-fluvalinate to CYP6BQ23. Taken together these results strongly suggest that the overexpression of CYP6BQ23 is the primary

Multiyear evaluation of the durability of the resistance conferred by Ma and RMia genes to Meloidogyne incognita in Prunus under controlled conditions.

Science.gov (United States)

Khallouk, Samira; Voisin, Roger; Portier, Ulysse; Polidori, Joël; Van Ghelder, Cyril; Esmenjaud, Daniel

2013-08-01

Root-knot nematodes (RKNs) (Meloidogyne spp.) are highly polyphagous pests that parasitize Prunus crops in Mediterranean climates. Breeding for RKN-resistant Prunus cultivars, as an alternative to the now-banned use of nematicides, is a real challenge, because the perennial nature of these trees increases the risk of resistance breakdown. The Ma plum resistance (R) gene, with a complete spectrum, and the RMia peach R gene, with a more restricted spectrum, both provide total control of Meloidogyne incognita, the model parthenogenetic species of the genus and the most important RKN in terms of economic losses. We investigated the durability of the resistance to this nematode conferred by these genes, comparing the results obtained with those for the tomato Mi-1 reference gene. In multiyear experiments, we applied a high and continuous nematode inoculum pressure by cultivating nematode-infested susceptible tomato plants with either Prunus accessions carrying Ma or RMia R genes, or with resistant tomato plants carrying the Mi-1 gene. Suitable conditions for Prunus development were achieved by carrying out the studies in a glasshouse, in controlled conditions allowing a short winter leaf fall and dormancy. We first assessed the plum accession 'P.2175', which is heterozygous for the Ma gene, in two successive 2-year evaluations, for resistance to two M. incognita isolates. Whatever the isolate used, no nematodes reproducing on P.2175 were detected, whereas galls and nematodes reproducing on tomato plants carrying Mi-1 were observed. In a second experiment with the most aggressive isolate, interspecific full-sib material (P.2175 × ['Garfi' almond × 'Nemared' peach]), carrying either Ma or RMia (from Nemared) or both (in the heterozygous state) or neither of these genes, was evaluated for 4 years. No virulent nematodes developed on Prunus spp. carrying R genes, whereas galling and virulent individuals were observed on Mi-1-resistant tomato plants. Thus, the resistance to

Wig1 prevents cellular senescence by regulating p21 mRNA decay through control of RISC recruitment.

Science.gov (United States)

Kim, Bong Cho; Lee, Hyung Chul; Lee, Je-Jung; Choi, Chang-Min; Kim, Dong-Kwan; Lee, Jae Cheol; Ko, Young-Gyu; Lee, Jae-Seon

2012-11-14

Premature senescence, a key strategy used to suppress carcinogenesis, can be driven by p53/p21 proteins in response to various stresses. Here, we demonstrate that Wig1 plays a critical role in this process through regulation of p21 mRNA stability. Wig1 controls the association of Argonaute2 (Ago2), a central component of the RNA-induced silencing complex (RISC), with target p21 mRNA via binding of the stem-loop structure near the microRNA (miRNA) target site. Depletion of Wig1 prohibited miRNA-mediated p21 mRNA decay and resulted in premature senescence. Wig1 plays an essential role in cell proliferation, as demonstrated in tumour xenografts in mice, and Wig1 and p21 mRNA levels are inversely correlated in human normal and cancer tissues. Together, our data indicate a novel role of Wig1 in RISC target accessibility, which is a key step in RNA-mediated gene silencing. In addition, these findings indicate that fine-tuning of p21 levels by Wig1 is essential for the prevention of cellular senescence.

21st Annual Conference of Ramanujan Mathematical Society

Indian Academy of Sciences (India)

Paper Presentation: Those who want to present papers should send an abstract of the paper along with a hard copy of the paper so as to reach the Local Secretary, 21st Annual. Conference of Ramanujan Mathematical Society, Department of Mathematics and Statis- tics, University of Hyderabad, Hyderabad 500046 on or ...

Potential impacts of NOx and SO2 constraints on CIPS operations

International Nuclear Information System (INIS)

Almasque, J.; Montgomery, D.; Le, K.; Boyle, R.; Nguyen, M.; Orndoff, D.

1994-01-01

To meet the Clean Air Act requirements, CIPS will need to spend around $30 million to curtail its SO 2 and NO x emissions by 40 percent. A key challenge facing CIPS management is to determine an emission compliance strategy that minimizes the total system production costs while maintaining a reasonable safety margin and back-up plan. CIPS is currently testing tools to perform emission-constrained unit commitment and economic dispatch. This ''soft'' option provides a back-up measure, should unforeseen occurrences take place or newly installed NO x reduction equipment fail to perform as expected. Algorithm development, software modification, procedural changes, and data collection required to implement emission-constrained dispatch will need to be in place by January, 1995. By taking advantage of ''soft'' methods, such as emission-constrained dispatch, emission trading, and operator training, CIPS hopes to reduce its emission-related capital expenditures by 5--20 percent

Astrophysical s-factor measurements for {sup 1}20Te(p,{gamma}){sup 1}21I and {sup 1}20Te(p,n){sup 1}20I reactions; {sup 1}20Te(p,{gamma}){sup 1}21I ve {sup 1}20Te(p,n){sup 1}20I reaksiyonlarinin astrofiziksel s-factor oelcuemleri

Energy Technology Data Exchange (ETDEWEB)

Gueray, R T; Oezkan, N; Yalcin, C [Kocaeli University, Kocaeli (Turkey); Goerres, J; DeBoer, R; Palumbo, A; Tan, W P; Wiescher, M [University of Notre Dame, (United States); Fueloep, Zs; Somorjai, E [Institute of Nuclear Research ATOMKI (Hungary); Lee, H Y [Argonne National Laboratory (United States)

2009-07-01

Astrophysical S-factors for the {sup 1}20Te(p,{gamma}){sup 1}21I and {sup 1}20Te(p,n){sup 1}20I reactions have been measured in the effective center-of-mass energies between 2.47 MeV and 7.93 MeV. Experimental data have been compared with the Hauser-Fesbach statistical model calculations obtained with the model codes NON-SMOKER and TALYS. The discrepancies between the experimental results and calculations can mainly be attributed to the optical model potentials used in the codes.

Reassortment and mutations associated with emergence and spread of oseltamivir-resistant seasonal influenza A/H1N1 viruses in 2005-2009.

Directory of Open Access Journals (Sweden)

Ji-Rong Yang

Full Text Available A dramatic increase in the frequency of the H275Y mutation in the neuraminidase (NA, conferring resistance to oseltamivir, has been detected in human seasonal influenza A/H1N1 viruses since the influenza season of 2007-2008. The resistant viruses emerged in the ratio of 14.3% and quickly reached 100% in Taiwan from September to December 2008. To explore the mechanisms responsible for emergence and spread of the resistant viruses, we analyzed the complete genome sequences of 25 viruses collected during 2005-2009 in Taiwan, which were chosen from various clade viruses, 1, 2A, 2B-1, 2B-2, 2C-1 and 2C-2 by the classification of hemagglutinin (HA sequences. Our data revealed that the dominant variant, clade 2B-1, in the 2007-2008 influenza emerged through an intra-subtype 4+4 reassortment between clade 1 and 2 viruses. The dominant variant acquired additional substitutions, including A206T in HA, H275Y and D354G in NA, L30R and H41P in PB1-F2, and V411I and P453S in basic polymerase 2 (PB2 proteins and subsequently caused the 2008-2009 influenza epidemic in Taiwan, accompanying the widespread oseltamivir-resistant viruses. We also characterized another 3+5 reassortant virus which became double resistant to oseltamivir and amantadine. Comparison of oseltamivir-resistant influenza A/H1N1 viruses belonging to various clades in our study highlighted that both reassortment and mutations were associated with emergence and spread of these viruses and the specific mutation, H275Y, conferring to antiviral resistance, was acquired in a hitch-hiking mechanism during the viral evolutionary processes.

Hepatocyte-specific deletion of the keap1 gene activates Nrf2 and confers potent resistance against acute drug toxicity

International Nuclear Information System (INIS)

Okawa, Hiromi; Motohashi, Hozumi; Kobayashi, Akira; Aburatani, Hiroyuki; Kensler, Thomas W.; Yamamoto, Masayuki

2006-01-01

Nrf2 is a key regulator of many detoxifying enzyme genes, and cytoplasmic protein Keap1 represses the Nrf2 activity under quiescent conditions. Germ line deletion of the keap1 gene results in constitutive activation of Nrf2, but the pups unexpectedly died before weaning. To investigate how constitutive activation of Nrf2 influences the detoxification system in adult mice, we generated mice bearing a hepatocyte-specific disruption of the keap1 gene. Homozygous mice were viable and their livers displayed no apparent abnormalities, but nuclear accumulation of Nrf2 is elevated. Microarray analysis revealed that, while many detoxifying enzyme genes are highly expressed, some of the typical Nrf2-dependent genes are only marginally increased in the Keap1-deficient liver. The mutant mice were significantly more resistant to toxic doses of acetaminophen than control animals. These results demonstrate that chronic activation of Nrf2 confers animals with resistance to xenobiotics without affecting the morphological and physiological integrity of hepatocytes

Metformin and Resveratrol Inhibited High Glucose-Induced Metabolic Memory of Endothelial Senescence through SIRT1/p300/p53/p21 Pathway.

Science.gov (United States)

Zhang, Erli; Guo, Qianyun; Gao, Haiyang; Xu, Ruixia; Teng, Siyong; Wu, Yongjian

2015-01-01

Endothelial senescence plays crucial roles in diabetic vascular complication. Recent evidence indicated that transient hyperglycaemia could potentiate persistent diabetic vascular complications, a phenomenon known as "metabolic memory." Although SIRT1 has been demonstrated to mediate high glucose-induced endothelial senescence, whether and how "metabolic memory" would affect endothelial senescence through SIRT1 signaling remains largely unknown. In this study, we investigated the involvement of SIRT1 axis as well as the protective effects of resveratrol (RSV) and metformin (MET), two potent SIRT1 activators, during the occurrence of "metabolic memory" of cellular senescence (senescent "memory"). Human umbilical vascular endothelial cells (HUVECs) were cultured in either normal glucose (NG)/high glucose (HG) media for 6 days, or 3 days of HG followed by 3 days of NG (HN), with or without RSV or MET treatment. It was shown that HN incubation triggered persistent downregulation of deacetylase SIRT1 and upregulation of acetyltransferase p300, leading to sustained hyperacetylation (at K382) and activation of p53, and subsequent p53/p21-mediated senescent "memory." In contrast, senescent "memory" was abrogated by overexpression of SIRT1 or knockdown of p300. Interestingly, we found that SIRT1 and p300 could regulate each other in response to HN stimulation, suggesting that a delicate balance between acetyltransferases and deacetylases may be particularly important for sustained acetylation and activation of non-histone proteins (such as p53), and eventually the occurrence of "metabolic memory." Furthermore, we found that RSV or MET treatment prevented senescent "memory" by modulating SIRT1/p300/p53/p21 pathway. Notably, early and continuous treatment of MET, but not RSV, was particularly important for preventing senescent "memory." In conclusion, short-term high glucose stimulation could induce sustained endothelial senescence via SIRT1/p300/p53/p21 pathway. RVS or MET

Comparative mapping of powdery mildew resistance gene Pm21 and functional characterization of resistance-related genes in wheat.

Science.gov (United States)

He, Huagang; Zhu, Shanying; Jiang, Zhengning; Ji, Yaoyong; Wang, Feng; Zhao, Renhui; Bie, Tongde

2016-04-01

The powdery mildew resistance gene Pm21 was physically and comparatively mapped by newly developed markers. Seven candidate genes were verified to be required for Pm21 -mediated resistance to wheat powdery mildew. Pm21, a gene derived from wheat wild relative Dasypyrum villosum, has been transferred into common wheat and widely utilized in wheat resistance breeding for powdery mildew. Previously, Pm21 has been located to the bin FL0.45-0.58 of 6VS by using deletion stocks. However, its fine mapping is still a hard work. In the present study, 30 gene-derived 6VS-specific markers were obtained based on the collinearity among genomes of Brachypodium distachyon, Oryza and Triticeae, and then physically and comparatively mapped in the bin FL0.45-0.58 and its nearby chromosome region. According to the maps, the bin FL0.45-0.58 carrying Pm21 was closely flanked by the markers 6VS-03 and 6VS-23, which further narrowed the orthologous regions to 1.06 Mb in Brachypodium and 1.38 Mb in rice, respectively. Among the conserved genes shared by Brachypodium and rice, four serine/threonine protein kinase genes (DvMPK1, DvMLPK, DvUPK and DvPSYR1), one protein phosphatase gene (DvPP2C) and two transcription factor genes (DvGATA and DvWHY) were confirmed to be required for Pm21-mediated resistance to wheat powdery mildew by barley stripe mosaic virus-induced gene silencing (BSMV-VIGS) and transcriptional pattern analyses. In summary, this study gives new insights into the genetic basis of the Pm21 locus and the disease resistance pathways mediated by Pm21.

Recessive resistance to Bean common mosaic virus conferred by the bc-1 and bc-2 genes in common bean (Phaseolus vulgaris L.) affects long distance movement of the virus.

Science.gov (United States)

Feng, Xue; Orellana, Gardenia; Myers, James; Karasev, Alexander V

2018-04-12

Recessive resistance to Bean common mosaic virus (BCMV) in common bean (Phaseolus vulgaris L.) is governed by four genes that include one strain-nonspecific helper gene bc-u, and three strain-specific genes bc-1, bc-2, and bc-3. The bc-3 gene was identified as an eIF4E translation initiation factor gene mediating resistance through disruption of the interaction between this protein and the VPg protein of the virus. The mode of action of bc-1 and bc-2 in expression of BCMV resistance is unknown, although bc-1 gene was found to affect systemic spread of a related potyvirus, Bean common mosaic necrosis virus. To investigate the possible role of both bc-1 and bc-2 genes in replication, cell-to-cell, and long distance movement of BCMV in P. vulgaris, we tested virus spread of eight BCMV isolates representing pathogroups I, IV, VI, VII, and VIII, in a set of bean differentials expressing different combinations of six resistance alleles including bc-u, bc-1, bc-1 2 , bc-2, bc-2 2 , and bc-3. All studied BCMV isolates were able to replicate and spread in inoculated leaves of bean cultivars harboring bc-u, bc-1, bc-1 2 , bc-2, and bc-2 2 alleles and their combinations, while no BCMV replication was found in inoculated leaves of 'IVT7214' carrying the bc-u, bc-2 and bc-3 genes, except for isolate 1755a capable of overcoming the resistance conferred by bc-2 and bc-3. In contrast, the systemic spread of all BCMV isolates from pathogroups I, IV,VI, VII, and VIII was impaired in common bean cultivars carrying bc-1, bc-1 2 , bc-2, and bc-2 2 alleles. The data suggest that bc-1 and bc-2 recessive resistance genes have no effect on the replication and cell-to-cell movement of BCMV, but affect systemic spread of BCMV in common bean. The BCMV resistance conferred by bc-1 and bc-2 and affecting systemic spread was found only partially effective when these two genes were expressed singly. The efficiency of the restriction of the systemic spread of the virus was greatly enhanced when