85 research outputs found

    AST1306, A Novel Irreversible Inhibitor of the Epidermal Growth Factor Receptor 1 and 2, Exhibits Antitumor Activity Both In Vitro and In Vivo

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    Despite the initial response to the reversible, ATP-competitive quinazoline inhibitors that target ErbB-family, such a subset of cancer patients almost invariably develop resistance. Recent studies have provided compelling evidence that irreversible ErbB inhibitors have the potential to override this resistance. Here, we found that AST1306, a novel anilino-quinazoline compound, inhibited the enzymatic activities of wild-type epidermal growth factor receptor (EGFR) and ErbB2 as well as EGFR resistant mutant in both cell-free and cell-based systems. Importantly, AST1306 functions as an irreversible inhibitor, most likely through covalent interaction with Cys797 and Cys805 in the catalytic domains of EGFR and ErbB2, respectively. Further studies showed that AST1306 inactivated pathways downstream of these receptors and thereby inhibited the proliferation of a panel of cancer cell lines. Although the activities of EGFR and ErbB2 were similarly sensitive to AST1306, ErbB2-overexpressing cell lines consistently exhibited more sensitivity to AST1306 antiproliferative effects. Consistent with this, knockdown of ErbB2, but not EGFR, decreased the sensitivity of SK-OV-3 cells to AST1306. In vivo, AST1306 potently suppressed tumor growth in ErbB2-overexpressing adenocarcinoma xenograft and FVB-2/Nneu transgenic breast cancer mouse models, but weakly inhibited the growth of EGFR-overexpressing tumor xenografts. Tumor growth inhibition induced by a single dose of AST1306 in the SK-OV-3 xenograft model was accompanied by a rapid (within 2 h) and sustained (≥24 h) inhibition of both EGFR and ErbB2, consistent with an irreversible inhibition mechanism. Taken together, these results establish AST1306 as a selective, irreversible ErbB2 and EGFR inhibitor whose growth-inhibitory effects are more potent in ErbB2-overexpressing cells

    Oral abstracts of the 21st International AIDS Conference 18-22 July 2016, Durban, South Africa

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    The rate at which HIV-1 infected individuals progress to AIDS is highly variable and impacted by T cell immunity. CD8 T cell inhibitory molecules are up-regulated in HIV-1 infection and associate with immune dysfunction. We evaluated participants (n=122) recruited to the SPARTAC randomised clinical trial to determine whether CD8 T cell exhaustion markers PD-1, Lag-3 and Tim-3 were associated with immune activation and disease progression.Expression of PD-1, Tim-3, Lag-3 and CD38 on CD8 T cells from the closest pre-therapy time-point to seroconversion was measured by flow cytometry, and correlated with surrogate markers of HIV-1 disease (HIV-1 plasma viral load (pVL) and CD4 T cell count) and the trial endpoint (time to CD4 count <350 cells/μl or initiation of antiretroviral therapy). To explore the functional significance of these markers, co-expression of Eomes, T-bet and CD39 was assessed.Expression of PD-1 on CD8 and CD38 CD8 T cells correlated with pVL and CD4 count at baseline, and predicted time to the trial endpoint. Lag-3 expression was associated with pVL but not CD4 count. For all exhaustion markers, expression of CD38 on CD8 T cells increased the strength of associations. In Cox models, progression to the trial endpoint was most marked for PD-1/CD38 co-expressing cells, with evidence for a stronger effect within 12 weeks from confirmed diagnosis of PHI. The effect of PD-1 and Lag-3 expression on CD8 T cells retained statistical significance in Cox proportional hazards models including antiretroviral therapy and CD4 count, but not pVL as co-variants.Expression of ‘exhaustion’ or ‘immune checkpoint’ markers in early HIV-1 infection is associated with clinical progression and is impacted by immune activation and the duration of infection. New markers to identify exhausted T cells and novel interventions to reverse exhaustion may inform the development of novel immunotherapeutic approaches

    Transcriptomic analysis of the late stages of grapevine (Vitis vinifera cv. Cabernet Sauvignon) berry ripening reveals significant induction of ethylene signaling and flavor pathways in the skin

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    Background: Grapevine berry, a nonclimacteric fruit, has three developmental stages; the last one is when berrycolor and sugar increase. Flavors derived from terpenoid and fatty acid metabolism develop at the very end of thisripening stage. The transcriptomic response of pulp and skin of Cabernet Sauvignon berries in the late stages ofripening between 22 and 37 \ub0Brix was assessed using whole-genome micorarrays.Results: The transcript abundance of approximately 18,000 genes changed with \ub0Brix and tissue type. There were alarge number of changes in many gene ontology (GO) categories involving metabolism, signaling and abioticstress. GO categories reflecting tissue differences were overrepresented in photosynthesis, isoprenoid metabolismand pigment biosynthesis. Detailed analysis of the interaction of the skin and pulp with \ub0Brix revealed that therewere statistically significantly higher abundances of transcripts changing with \ub0Brix in the skin that were involved inethylene signaling, isoprenoid and fatty acid metabolism. Many transcripts were peaking around known optimalfruit stages for flavor production. The transcript abundance of approximately two-thirds of the AP2/ERF superfamilyof transcription factors changed during these developmental stages. The transcript abundance of a unique clade ofERF6-type transcription factors had the largest changes in the skin and clustered with genes involved in ethylene,senescence, and fruit flavor production including ACC oxidase, terpene synthases, and lipoxygenases. The transcriptabundance of important transcription factors involved in fruit ripening was also higher in the skin.Conclusions: A detailed analysis of the transcriptome dynamics during late stages of ripening of grapevine berriesrevealed that these berries went through massive transcriptional changes in gene ontology categories involvingchemical signaling and metabolism in both the pulp and skin, particularly in the skin. Changes in the transcriptabundance of genes involved in the ethylene signaling pathway of this nonclimacteric fruit were statisticallysignificant in the late stages of ripening when the production of transcripts for important flavor and aroma compoundswere at their highest. Ethylene transcription factors known to play a role in leaf senescence also appear to play a role infruit senescence. Ethylene may play a bigger role than previously thought in this non-climacteric fruit

    Antimicrobial host defense peptides in an arteriviral infection: differential peptide expression and virus inactivation

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    Antimicrobial host defense peptides (AHDPs) are effective against a wide range of microbes, including viruses. The arteriviral infection caused by porcine reproductive and respiratory syndrome virus (PRRSV) is a devastating pandemic that causes the most economically significant disease of swine. We sought to determine if the expression of AHDPs was influenced by infection with PRRSV, and if porcine AHDPs have direct antiviral activity against PRRSV. Because pulmonary alveolar macrophages (PAMs) are primary targets of PRRSV infection, gene expression of porcine AHDPs was evaluated in lungs from fetal and 2-wk-old congenitally infected pigs. In PRRSV-positive lungs and PAMs, gene expression of most porcine AHDPs showed little upregulation. However, gene expression of porcine β-defensin-1 (pBD-1), pBD-4, pBD-104, pBD-123, and pBD-125 were downregulated more than threefold in 2-wk-old congenitally infected pig lungs. Incubation of PRRSV with pBD-3 or PG-4 significantly inhibited viral infectivity in MARC-145 cells. Using nine protegrin or protegrin-derived peptides, we determined that a cyclic analog of PG-4 increased anti-PRRSV activity, and that substitution of phenylalanine with valine eliminated most PG-4 antiviral activity. In PAMs, pBD-3 and PG-4 at 5–40 μg/mL consistently suppressed PRRSV titers. Collectively, these findings suggest a potential role for some porcine AHDPs as innate antiviral effectors in PRRSV infection. Moreover, modulation of porcine innate immune mechanisms with AHDPs may be one means of limiting the impact of this costly pandemic viral disease

    Análise conceitual de autogestão do indivíduo hipertenso

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    Objetivou analisar conceito de autogestão do indivíduo hipertenso. Estudo teórico pautado na análise conceitual Walker e Avant mediante as bases de dados Scientific Electronic Library Brazil e Medical Literature Analysis and Retrievel System Online. Foram selecionados e analisados 14 artigos e 1 tese, em português e inglês, no recorte temporal de janeiro/2007 a setembro/2012. Antecedentes: ausência à consulta médica, falta de adesão ao tratamento do controle da pressão arterial, recomendações do padrão dietético adequado e estresse. Atributos: controle da pressão arterial e gestão da doença. Consequências: monitorização da pressão arterial domiciliar com melhora do controle, realização de gestão da doença, aceitação e compartilhamento no processo criação de metas de autogestão e atividades de cuidados pela equipe interdisciplinar mediante ações individualizadas. Concluiu-se que o conceito de autogestãoé um processo dinâmico e ativo, requerendo conhecimento, atitude, disciplina, determinação, comprometimento, autorregulação, empoderamento e autoeficácia, a fim de gerir a doença para o alcance de um viver saudável
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