1,438 research outputs found

    Generalized quaternion groups with the mm-DCI property

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    A Cayley digraph Cay(G,S) of a finite group GG with respect to a subset SS of GG is said to be a CI-digraph if for every Cayley digraph Cay(G,T) isomorphic to Cay(G,S), there exists an automorphism σ\sigma of GG such that Sσ=TS^\sigma=T. A finite group GG is said to have the mm-DCI property for some positive integer mm if all mm-valent Cayley digraphs of GG are CI-digraphs, and is said to be a DCI-group if GG has the mm-DCI property for all 1≤m≤∣G∣1\leq m\leq |G|. Let Q4n\mathrm{Q}_{4n} be a generalized quaternion group of order 4n4n with an integer n≥3n\geq 3, and let Q4n\mathrm{Q}_{4n} have the mm-DCI property for some 1≤m≤2n−11 \leq m\leq 2n-1. It is shown in this paper that nn is odd, and nn is not divisible by p2p^2 for any prime p≤m−1p\leq m-1. Furthermore, if n≥3n\geq 3 is a power of a prime pp, then Q4n\mathrm{Q}_{4n} has the mm-DCI property if and only if pp is odd, and either n=pn=p or 1≤m≤p1\leq m\leq p.Comment: 1

    [μ-11,23-Dibromo-3,7,15,19-tetra­aza­tri­cyclo­[19.3.1.19,13]hexa­cosa-1(25),2,7,9,11,13(26),14,19,21,23-deca­ene-25,26-diolato-κ4 N 3,N 7,O,O′:κ4 O,O′,N 15,N 19]bis[perchloratocopper(II)]

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    The title complex, [Cu2(C22H20Br2N4O2)(ClO4)2], was prepared by the condensation of 2,6-diformyl-4-bromo­phenol with 1,3-diamino­propane in the presence of copper(II) ions. The macrocyclic ligand shows an approximately planar structure except for the two propene groups in the macrocycle. The coordination polyhedron of each Cu atom can be described as distorted square pyramidal. The two Cu atoms are bridged by two phenolate O atoms of the macrocycle, with a Cu⋯Cu distance of 3.109 (2) Å

    Knockdown of c-Myc expression by RNAi inhibits MCF-7 breast tumor cells growth in vitro and in vivo

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    INTRODUCTION: Breast cancer is the leading cause of cancer death in women worldwide. Elevated expression of c-Myc is a frequent genetic abnormality seen in this malignancy. For a better understanding of its role in maintaining the malignant phenotype, we used RNA interference (RNAi) directed against c-Myc in our study. RNAi provides a new, reliable method to investigate gene function and has the potential for gene therapy. The aim of the study was to examine the anti-tumor effects elicited by a decrease in the protein level of c-Myc by RNAi and its possible mechanism of effects in MCF-7 cells. METHOD: A plasmid-based polymerase III promoter system was used to deliver and express short interfering RNA (siRNA) targeting c-myc to reduce its expression in MCF-7 cells. Western blot analysis was used to measure the protein level of c-Myc. We assessed the effects of c-Myc silencing on tumor growth by a growth curve, by soft agar assay and by nude mice experiments in vivo. Standard fluorescence-activated cell sorter analysis and TdT-mediated dUTP nick end labelling assay were used to determine apoptosis of the cells. RESULTS: Our data showed that plasmids expressing siRNA against c-myc markedly and durably reduced its expression in MCF-7 cells by up to 80%, decreased the growth rate of MCF-7 cells, inhibited colony formation in soft agar and significantly reduced tumor growth in nude mice. We also found that depletion of c-Myc in this manner promoted apoptosis of MCF-7 cells upon serum withdrawal. CONCLUSION: c-Myc has a pivotal function in the development of breast cancer. Our data show that decreasing the c-Myc protein level in MCF-7 cells by RNAi could significantly inhibit tumor growth both in vitro and in vivo, and imply the therapeutic potential of RNAi on the treatment of breast cancer by targeting overexpression oncogenes such as c-myc, and c-myc might be a potential therapeutic target for human breast cancer

    Large-scale rewiring of innate immunity circuitry and microRNA regulation during initial rice blast infection

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    Rice blast is a recurrent fungal disease, and resistance to fungal infection is a complex trait. Therefore, a comprehensive examination of rice transcriptome and its variation during fungal infection is necessary to understand the complex gene regulatory networks. In this study, adopting Next-Generation Sequencing we profiled the transcriptomes and microRNAomes of rice varieties, one susceptible and the other resistant to M. oryzae, at multiple time points during the fungal infection. Our results revealed a substantial variation in the plant transcriptome and microRNAome as well as change to rice innate immunity during fungal infection. A number of putative R gene candidates were identified from a perturbed rice transcriptome analysis. The expression of genes and non-coding RNA molecules changed in both fungal resistant and susceptible plants during M. oryzae invasion discovered distinct pathways triggered in the susceptible and resistant plants. In addition, a number of fungus genes in the susceptible and resistant plants were constantly expressed at different time points, suggesting that they were likely to be the potential AVR genes. Our results revealed large-scale rewiring of innate immunity circuitry and microRNA regulation during initial rice blast infection, which would help to develop more robust blast-resistant rice plants

    Paleocene (c. 62 Ma) leucogranites in southern Lhasa, Tibet: products of syn-collisional crustal anatexis during slab roll-back?

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    Voluminous peraluminous leucogranites are common in large-scale orogenic belts and are crucial in gaining a fuller understanding of the related geodynamic process. However, the origin of such syn-collisional leucogranites remains highly controversial. In this contribution, we report petrological and geochemical data for Paleocene (c. 63 Ma) garnet-bearing, two-mica granites and associated biotite granites from the Gangdese batholith in southern Tibet. The Zhengga biotite granites have high SiO2 (70–73 wt %) and low MgO (0·4–0·7 wt %) contents with initial 87Sr/86Sr ratios of 0·7049–0·7050, εNd(t) values of +0·5 to +1·2 and zircon δ18O values of 5·6–6·9‰, similar to most early Paleocene granitoids in southern Lhasa. These geochemical characteristics suggest that the Zhengga biotite granites were derived from a crustal source that mixed with variable amounts of Gangdese juvenile lower crust and minor ancient crust-derived melts. The Zhengga peraluminous, garnet-bearing, two-mica granites have similar Sr–Nd–O isotope compositions to the biotite granites (0·7037–0·7050, +0·4 to +0·8, 5·5–7·3‰, respectively) as well as higher SiO2 (73–76 wt %) and lower TiO2 (<0·06 wt %), MgO (<0·3 wt %), Fe2 OT3 (<2 wt %) and CaO (<0·7 wt %) contents. These most probably represent highly evolved biotite granite magmas that differentiated in the mid-crust. The first contact of India with Asia appears to have occurred in central Lhasa during the early Paleocene (65–63 Ma) and led to crustal thickening and cessation of magmatism. Early Paleocene slab roll-back would have significantly enhanced asthenospheric corner flow and supplied a long-lived heat source for coeval crustal anatexis and metamorphism in southern Lhasa during the early phase of continental collision. Similar interaction between continental collision and oceanic subduction may also occur in other large-scale convergence zones in which the lithosphere and crust are anomalously hot

    Research Progress on PARP14 as a Drug Target

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    Poly-adenosine diphosphate-ribose polymerase (PARP) implements posttranslational mono- or poly-ADP-ribosylation modification of target proteins. Among the known 18 members in the enormous family of PARP enzymes, several investigations about PARP1, PARP2, and PARP5a/5b have been launched in the past few decades; more specifically, PARP14 is gradually emerging as a promising drug target. An intact PARP14 (also named ARTD8 or BAL2) is constructed by macro1, macro2, macro3, WWE, and the catalytic domain. PARP14 takes advantage of nicotinamide adenine dinucleotide (NAD+) as a metabolic substrate to conduct mono-ADP-ribosylation modification on target proteins, taking part in cellular responses and signaling pathways in the immune system. Therefore, PARP14 has been considered a fascinating target for treatment of tumors and allergic inflammation. More importantly, PARP14 could be a potential target for a chemosensitizer based on the theory of synthetic lethality and its unique role in homologous recombination DNA repair. This review first gives a brief introduction on several representative PARP members. Subsequently, current literatures are presented to reveal the molecular mechanisms of PARP14 as a novel drug target for cancers (e.g., diffuse large B-cell lymphoma, multiple myeloma, prostate cancer, and hepatocellular carcinoma) and allergic inflammatory. Finally, potential PARP inhibitor-associated adverse effects are discussed. The review could be a meaningful reference for innovative drug or chemosensitizer discovery targeting to PARP14

    MiR-221 and miR-222 target PUMA to induce cell survival in glioblastoma

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    <p>Abstract</p> <p>Background</p> <p>MiR-221 and miR-222 (miR-221/222) are frequently up-regulated in various types of human malignancy including glioblastoma. Recent studies have reported that miR-221/222 regulate cell growth and cell cycle progression by targeting p27 and p57. However the underlying mechanism involved in cell survival modulation of miR-221/222 remains elusive.</p> <p>Results</p> <p>Here we showed that miR-221/222 inhibited cell apoptosis by targeting pro-apoptotic gene PUMA in human glioma cells. Enforced expression of miR-22/222 induced cell survival whereas knockdown of miR-221/222 rendered cells to apoptosis. Further, miR-221/222 reduced PUMA protein levels by targeting PUMA-3'UTR. Introducing PUMA cDNA without 3'UTR abrogated miR-221/222-induced cell survival. Notably, knockdown of miR-221/222 induces PUMA expression and cell apoptosis and considerably decreases tumor growth in xenograft model. Finally, there was an inverse relationship between PUMA and miR-221/222 expression in glioma tissues.</p> <p>Conclusion</p> <p>To our knowledge, these data indicate for the first time that miR-221/222 directly regulate apoptosis by targeting PUMA in glioblastoma and that miR-221/222 could be potential therapeutic targets for glioblastoma intervention.</p
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