259 research outputs found

    PTTG1 Levels Are Predictive of Saracatinib Sensitivity in Ovarian Cancer Cell Lines

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    Src kinase is recognized as a key target for molecular cancer therapy. However, methods to efficiently select patients responsive to Src inhibitors are lacking. We explored the sensitivity of ovarian cancer cell lines to the Src kinase inhibitor saracatinib to identify predictive markers of drug sensitivity using gene microarrays. Pituitary tumor transforming gene 1 (PTTG1) was selected as a potential biomarker as mRNA levels were correlated with saracatinib resistance, as well as higher PTTG1 protein expression. PTTG1 expression was correlated with proliferation, cell division, and mitosis in ovarian cancer tissues data sets. In sensitive cell lines, saracatinib treatment decreased PTTG1 and fibroblast growth factor 2 (FGF2) protein levels. Downregulating PTTG1 by siRNAs increased saracatinib sensitivity in two resistant cell lines. Our results indicate PTTG1 may be a valuable biomarker in ovarian cancer to predict sensitivity to saracatinib, and could form the basis of a targeted prospective saracatinib trial for ovarian cancer

    ProRepeat: an integrated repository for studying amino acid tandem repeats in proteins

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    ProRepeat (http://prorepeat.bioinformatics.nl/) is an integrated curated repository and analysis platform for in-depth research on the biological characteristics of amino acid tandem repeats. ProRepeat collects repeats from all proteins included in the UniProt knowledgebase, together with 85 completely sequenced eukaryotic proteomes contained within the RefSeq collection. It contains non-redundant perfect tandem repeats, approximate tandem repeats and simple, low-complexity sequences, covering the majority of the amino acid tandem repeat patterns found in proteins. The ProRepeat web interface allows querying the repeat database using repeat characteristics like repeat unit and length, number of repetitions of the repeat unit and position of the repeat in the protein. Users can also search for repeats by the characteristics of repeat containing proteins, such as entry ID, protein description, sequence length, gene name and taxon. ProRepeat offers powerful analysis tools for finding biological interesting properties of repeats, such as the strong position bias of leucine repeats in the N-terminus of eukaryotic protein sequences, the differences of repeat abundance among proteomes, the functional classification of repeat containing proteins and GC content constrains of repeats’ corresponding codons

    Human Galectins Induce Conversion of Dermal Fibroblasts into Myofibroblasts and Production of Extracellular Matrix: Potential Application in Tissue Engineering and Wound Repair

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    Members of the galectin family of endogenous lectins are potent adhesion/growth-regulatory effectors. Their multi-functionality opens possibilities for their use in bioapplications. We studied whether human galectins induce the conversion of human dermal fibroblasts into myofibroblasts (MFBs) and the production of a bioactive extracellular matrix scaffold is suitable for cell culture. Testing a panel of galectins of all three subgroups, including natural and engineered variants, we detected activity for the proto-type galectin-1 and galectin-7, the chimera-type galectin-3 and the tandem-repeat-type galectin-4. The activity of galectin-1 required the integrity of the carbohydrate recognition domain. It was independent of the presence of TGF-beta 1, but it yielded an additive effect. The resulting MFBs, relevant, for example, for tumor progression, generated a matrix scaffold rich in fibronectin and galectin-1 that supported keratinocyte culture without feeder cells. Of note, keratinocytes cultured on this substratum presented a stem-like cell phenotype with small size and keratin-19 expression. In vivo in rats, galectin-1 had a positive effect on skin wound closure 21 days after surgery. In conclusion, we describe the differential potential of certain human galectins to induce the conversion of dermal fibroblasts into MFBs and the generation of a bioactive cell culture substratum. Copyright (C) 2011 S. Karger AG, Base

    2-Aminophenoxazine-3-one and 2-amino-4,4α-dihydro-4α,7-dimethyl-3H-phenoxazine-3-one cause cellular apoptosis by reducing higher intracellular pH in cancer cells

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    We examined intracellular pH (pHi) of ten cancer cell lines derived from different organs and two normal cell lines including human embryonic lung fibroblast cells (HEL) and human umbilical vein endothelial cells (HUVEC) in vitro, and found that pHi of most of these cancer cells was evidently higher (pH 7.5 to 7.7) than that of normal cells (7.32 and 7.44 for HEL and HUVEC, respectively) and that of primary leukemic cells and erythrocytes hitherto reported (≤7.2). Higher pHi in these cancer cells could be related to the Warburg effect in cancer cells with enhanced glycolytic metabolism. Since reversal of the Warburg effect may perturb intracellular homeostasis in cancer cells, we looked for compounds that cause extensive reduction of pHi, a major regulator of the glycolytic pathway and its associated metabolic pathway. We found that phenoxazine compounds, 2-aminophenoxazine-3-one (Phx-3) and 2-amino-4,4α-dihydro-4α,7-dimethyl-3H-phenoxazine-3-one (Phx-1) caused a rapid and drastic dose-dependent decrease of pHi in ten different cancer cells within 30 min, though the extent of the decrease of pHi was significantly larger for Phx-3 (ΔpHi = 0.6 pH units or more for 100 µM Phx-3) than for Phx-1 (ΔpHi = 0.1 pH units or more for 100 µM Phx-1). This rapid and drastic decrease of pHi in a variety of cancer cells caused by Phx-3 and Phx-1 possibly perturbed their intracellular homeostasis, and extensively affected the subsequent cell death, because these phenoxazines exerted dose-dependent proapoptotic and cytotoxic effects on these cells during 72 h incubation, confirming a causal relationship between ΔpHi and cytotoxic effects due to Phx-3 and Phx-1. Phx-3 and Phx-1 also reduced pHi of normal cells including HEL and HUVEC, although they exerted less proapoptotic and cytotoxic effects on these cells than on cancer cells. Drugs such as Phx-3 and Phx-1 that reduce pHi and thereby induce cellular apoptosis might serve as benevolent anticancer drugs

    Protestant women in the late Soviet era: gender, authority, and dissent

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    At the peak of the anti-religious campaigns under Nikita Khrushchev, communist propaganda depicted women believers as either naïve dupes, tricked by the clergy, or as depraved fanatics; the Protestant “sektantka” (female sectarian) was a particularly prominent folk-devil. In fact, as this article shows, women’s position within Protestant communities was far more complex than either of these mythical figures would have one believe. The authors explore four important, but contested, female roles: women as leaders of worship, particularly in remote congregations where female believers vastly outnumbered their male counterparts; women as unofficial prophetesses, primarily within Pentecostal groups; women as mothers, replenishing congregations through high birth rates and commitment to their children’s religious upbringing; and women as political actors in the defence of religious rights. Using a wide range of sources, which include reports written by state officials, articles in the church journal, letters from church members to their ecclesiastical leaders in Moscow, samizdat texts, and oral history accounts, the authors probe women’s relationship with authority, in terms of both the authority of the (male) ministry within the church, and the authority of the Soviet state
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