20 research outputs found

    Resultative Compound Verb in Modern Chinese : A Comment on Imai(1985) and Lu(1986)

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    <p>A. API and DMO suppresses NF-κB DNA binding ability in HCT116 cells. HCT116 cells were treated with DMO and API at indicated doses, nuclear extracts were prepared, and 20 μg of the nuclear extract protein was used for the ELISA-based DNA-binding assay *p<0.05; **p<0.005). B & C. NF-κB responsive elements linked to a luciferase reporter gene were transfected with wild-type or dominant-negative IκB and transfected cancer cells were treated at indicated doses for 6 h and luciferase activity was measured as described in Materials and Methods section. All luciferase experiments were done in triplicate and repeated twice (*p<0.05; **p<0.005). D. API abrogates constitutive IκBα phosphorylation in dose-dependent manner in HCT116 cells. HCT116 cells were treated with different concentrations of API (0, 5, 10 and 20 μM) for 6 h and cytoplasmic extract was prepared. Lysates were resolved on SDS gel and electrotransferred to a nitrocellulose membrane and probed with anti-phospho-IκBα/IκBα. The blot was washed, exposed to HRP-conjugated secondary antibodies for 1 h, and finally examined by chemiluminescence. GAPDH was used as loading control.</p

    A novel benzimidazole derivative binds to the DNA minor groove and induces apoptosis in leukemic cells

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    DNA minor groove binders are an important class of chemotherapeutic agents. These small molecule inhibitors interfere with various cellular processes like DNA replication and transcription. Several benzimidazole derivatives showed affinity towards the DNA minor groove. In this study we show the synthesis and biological studies of a novel benzimidazole derivative (MH1), that inhibits topoisomerase II activity and in vitro transcription. UV-visible and fluorescence spectroscopic methods in conjunction with Hoechst displacement assay demonstrate that MH1 binds to DNA at the minor groove. Cytotoxic studies showed that leukemic cells are more sensitive to MH1 compared to cancer cells of epithelial origin. Further, we find that MH1 treatment leads to cell cycle arrest at G2/M, at early time points in Molt4 cells. Finally multiple cellular assays demonstrate that MH1 treatment leads to reduction in MMP, induction of apoptosis by activating CASPASE 9 and CASPASE 3. Thus our study shows MH1, a novel DNA minor groove binder, induces cytotoxicity efficiently in leukemic cells by activating the intrinsic pathway of apoptosis

    SYNTHESIS AND ACETYLCHOLINESTERASE/BUTYRYLCHOLINESTERASE INHIBITION ACTIVITY OF ARECOLINE-, 4-THIAZOLIDINONE- AND PIPERIDINE- BASED CONJUGATES

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    Objective: The aim of the study is to design, synthesize and identification of novel acetylcholinesterase/butyrylcholinesterase (AChE/BuChE)inhibitors.Methods: The AChE and BuChE inhibition activity of a library of piperidine and 4-thiazolidinone substituted arecoline derivatives are described. Thechemical structures of newly synthesized compounds were confirmed by IR, 1H NMR, 13C NMR and mass spectral analysis.Results: The cholinesterase inhibition assays indicated that few of the synthesized compounds exhibited considerable activity at micromolar rangefor AChE over BuChE. Compound 7c exhibited the most potent AChE inhibitory activity with an IC50 value of 6.62 μM for AChE and 13.78 μM for BuChE,which is comparable to the standard Neostigmine with an IC50 2.05 μM for AChE and 3.64 μM for BuChE respectively.Conclusion: Our results clearly demonstrate that arecoline-4-thiazolidinone derivatives open up a new avenue in the field of Alzheimer's disease.Keywords: Arecoline analogs, Propylphosphonic anhydride (T3P®), Acetylcholinesterase/butyrylcholinesterase inhibitor, 4-thiazolidinones

    Regioselective synthesis and biological studies of novel 1-aryl-3, 5-bis (het) aryl pyrazole derivatives as potential antiproliferative agents

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    Pyrazole moiety represents an important category of heterocyclic compound in pharmaceutical and medicinal chemistry. The novel 1-aryl-3, 5-bis (het) aryl pyrazole derivatives were synthesized with complementary regioselectivity. The chemical structures were confirmed by IR, 1H NMR, 13C NMR, and mass spectral analysis. The chemical entities were screened in various cancer cell lines to assess their cell viability activity. Results showed that the compound 3-(1-(4-bromophenyl)-5-phenyl-1H-pyrazol-3-yl) pyridine (5d) possessed maximum cytotoxic effect against breast cancer and leukemic cells. The cytotoxicity was confirmed by live--dead cell assay and cell cycle analysis. Mitochondrial membrane potential, Annexin V-FITC staining, DNA fragmentation, Hoechst staining, and western blot assays revealed the ability of compound 5d to induce cell death by activating apoptosis in cancer cells. Thus, the present study demonstrates that compound 5d could be an attractive chemical entity for the development of small molecule inhibitors for treatment of leukemia and breast cancer

    Captive and free living European starlings use differently their song repertoire

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    National audienceL'utilisation de différents types de chant en fonction du contexte semble un fait commun chez les oiseaux chanteurs. Cependant, nous possédons peu d'informations concernant l'effet de la captivité sur l'utilisation du répertoire. Nous avons observé et comparé le comportement vocal de quatre Étourneaux sansonnets américains sauvages et de quatre Étourneaux sansonnets américains captifs pendant la même période de 1' année. Les résultats montrent que la qualité et la quantité de chant produit diffèrent dans les deux situations. L'environnement social joue un rôle déterminant dans l'utilisation du chant chez l'étourneau. Nos résultats montrent également que les oiseaux ne produisent pas nécessairement la totalité de leur "répertoire" de chant dans différents contextes sociaux

    Synthesis and Biological Evaluation of Novel Thiazol-2yl-amine Derivatives as Potential Anticancer Agents

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    Background: Chronic myelogenous leukemia (CML) is a myeloproliferative neoplasm that can occur in any age group but often seen in adults and contributing for about 20% of adult leukemias and it may contribute up to 15% of all types of leukemias threatening the globe. Therefore, treatment of CML remains as a major challenge in cancer therapeutics. Methods: We synthesized a library of novel 2-amino-4-(4-substituted phenyl) thiazole derivatives and evaluated their anti-leukemic activity by trypan blue and MTT assay. 4-(4'-phenoxybiphenyl-4-yl) thiazol-2-amine (compound 3m) was identified as a lead anticancer agent and further, the effect of 3m on CML cells (K562) was investigated by flow cytometry, annexin V-FITC-propidium iodide staining, measuring the mitochondrial membrane potential (JC-1 staining) and DNA fragmentation assay. Results: MTT and trypan blue dye exclusion assay results presented 3m as the lead anticancer agent. Flow cytometric analysis revealed the accumulation of K562 cells in subG1phase in a time-and dose-dependent manner. Annexin-V-FITC-PI staining demonstrated the increase in percentage of apoptotic cells on treatment with 3m. Furthermore, 3m also induced DNA fragmentation and disrupted mitochondrial membrane potential in K562 cells in dose-dependent manner. In addition, apoptosis inducing effect of 3m was reconfirmed by live-dead assay and confocal microscopic studies. Conclusion: The present study suggests that compound 3m has the potential to be a promising candidate for the treatment of CML

    Novel Synthetic Oxazines Target NF-κB in Colon Cancer In Vitro and Inflammatory Bowel Disease In Vivo.

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    Aberrant activation of nuclear factor kappa B (NF-κB) has been linked with the pathogenesis of several proinflammatory diseases including number of cancers and inflammatory bowel diseases. In the present work, we evaluated the anticancer activity of 1,2-oxazines derivatives against colorectal cancer cell lines and identified 2-((2-acetyl-6,6-dimethyl-4-phenyl-5,6-dihydro-2H-1,2-oxazin-3-yl)methyl)isoindoline-1,3-dione (API) as the lead anticancer agent among the tested compounds. The apoptosis inducing effect of API was demonstrated using flow cytometry analysis and measuring the caspase 3/7 activity in API treated cells. Based on the literature on inhibition of NF-κB by oxazines, we evaluated the effect of 1,2-oxazines against the ability of NF-κB binding to DNA, NF-κB-dependent luciferase expression and IκBα phosphorylation. We found that, API abrogate constitutive activation of NF-κB and inhibits IκBα phosphorylation in HCT116 cells. Our in silico analysis revealed the binding of oxazines to the hydrophobic cavity that present between the interface of p65 and IκBα. Given the relevance with aberrant activation of NF-κB in inflammation bowel disease (IBD), we evaluated the effect of API on dextran sulphate sodium-induced IBD mice model. The treatment of IBD induced mice with API decreased the myeloperoxidase activity in colonic extract, modulated the colon length and serum levels of pro- and anti-inflammatory cytokines such as TNF-α, IFN-γ, IL-6, IL-1β and IL-10. Furthermore, the histological analysis revealed the restoration of the distorted cryptic epithelial structure of colon in the API treated animals. In conclusion, we comprehensively validated the NF-κB inhibitory efficacy of API that targets NF-κB in in vitro colon cancer and an in vivo inflammatory bowel disease model

    Autocyclized and oxidized forms of SCR7 induce cancer cell death by inhibiting nonhomologous DNA end joining in a Ligase IV dependent manner

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    International audienceNonhomologous DNA end joining (NHEJ) is the major DNA double-strand break (DSB) repair pathway in mammals. Previously, we have described a small molecule inhibitor, SCR7, which can inhibit NHEJ in a Ligase IV-dependent manner. Administration of SCR7 within the cells resulted in the accumulation of DNA breaks, cell death, and inhibition of tumor growth in mice. In the present study, we report that parental SCR7, which is unstable, can be autocyclized into a stable form. Both parental SCR7 and cyclized SCR7 possess the same molecular weight (334.09) and molecular formula (C18H14N4OS), whereas its oxidized form, SCR7-pyrazine, possesses a different molecular formula (C18H12N4OS), molecular weight (332.07), and structure. While cyclized form of SCR7 showed robust inhibition of NHEJ in vitro, both forms exhibited efficient cytotoxicity. Cyclized and oxidized forms of SCR7 inhibited DNA end joining catalyzed by Ligase IV, whereas their impact was minimal on Ligase III, Ligase I, and T4 DNA Ligase-mediated joining. Importantly, both forms inhibited V(D)J recombination, although the effect was more pronounced for SCR7-cyclized. Both forms blocked NHEJ in a Ligase IV-dependent manner leading to the accumulation of DSBs within the cells. Although cytotoxicity due to SCR7-cyclized was Ligase IV specific, the pyrazine form exhibited nonspecific cytotoxicity at higher concentrations in Ligase IV-null cells. Finally, we demonstrate that both forms can potentiate the effect of radiation. Thus, we report that cyclized and oxidized forms of SCR7 can inhibit NHEJ in a Ligase IV-dependent manner, although SCR7-pyrazine is less specific to Ligase IV inside the cell
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