97 research outputs found

    Pyrrolidine-based cationic γ-peptide: a DNA-binding molecule works as a potent anti-gene agent

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    Pyrrolidine-based cationic peptides showing high stability to enzyme degradation and strong binding affinity towards DNA are widely investigated as tools to interfere in gene expression. Several studies have been focused on γ-peptide analogs with modifications on the peptide backbone in the attempt to overcome solubility, uptake, and aggregation issues. Pyrrolidine-based γ-peptide derivatives having two different modes of backbone conformation show interesting properties in terms of secondary structure and affinity of binding towards nucleic acids. In this paper, we illustrate our results obtained on two cationic 8-mer γ-peptides Gp1 and Gp2, and how they differ in side-chain spacing along the backbone was tested for DNA binding and DNA transfection activity. Both γ-peptides are stable toward protease digestion. Gp1 binds to DNA more tightly than GP2. This binding ability of Gp1 is attributed to its characteristic of single-chain PPII-like conformation. The Gp1 shows a reduction in its electrophoretic mobility when treated with plasmid DNA. The DNA transfection ability of γ-peptide Gp1 was compared with commercially available transfection reagent Effectene. In each case, Gp1 significantly enhanced the transfection efficiency (40%) of plasmid in Schneider cells compared to the commercial reagent (18%). The other γ-peptide GP2 is not active

    Nano-​cuprous oxide catalyzed one-​pot synthesis of a carbazole-​based STAT3 inhibitor: a facile approach via intramolecular C-​N bond formation reactions

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    In this study, we report the one-​pot synthesis of substituted carbazole derivs. using nano cuprous oxide as a catalyst via intramol. C-​N bond forming reactions. Among the synthesized carbazoles, 3'-​((3-​acetyl-​6-​chloro-​9H-​carbazol-​9-​yl)​methyl)​-​[1,​1'-​biphenyl]​-​2-​carbonitrile (ACB) was identified as a lead antiproliferative agent against lung cancer cell lines A549 and LLC with an IC50 of 13.6 and 16.4 μM resp. Furthermore, we found that the lead compd. suppresses the constitutive phosphorylation of STAT3 (Tyr-​705) in A549, HCC-​2279 and H1975 cells. We analyzed the levels of phospho-​STAT3 and LSD1 in the nuclear ext. of ACB treated HCC-​2279 cells to evaluate the transcriptional activity of STAT3. We found the downregulation of phospho-​STAT3 without any change in the expression of LSD1 indicating that ACB downregulates the transcriptional activity of STAT3. Mol. docking anal. revealed that ACB makes a favorable interaction with Arg-​609 and Ser-​613 in the pTyr site of the SH2 domain of STAT3

    Synthesis, biological evaluation and in silico and in vitro mode-of-action analysis of novel dihydropyrimidones targeting PPAR-gamma

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    Hepatocellular carcinoma, a fatal liver cancer, affects 600 000 people annually and ranks third in cancer-related lethality. In this work we report the synthesis and related biological activity of novel dihydropyrimidones. Among the tested compounds, 5-acetyl-4-(1H-indol- 3-yl)-6-methyl-3,4-dihydropyrimidin-2(1H)-one (4g) was found to be most active towards the HepG2 cell line (IC50 = 17.9 mu M), being at the same time 7.6-fold selective over normal (LO2) liver cells (IC50 = 136.9 mu M). Subsequently, we identified peroxisome proliferator-activated receptor gamma as a target of compound 4g using an in silico approach, and confirmed this mode-of-action experimentally

    Identification of Novel Class of Triazolo-Thiadiazoles as Potent Inhibitors of Human Heparanase and their Anticancer Activity.

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    BACKGROUND: Expression and activity of heparanase, an endoglycosidase that cleaves heparan sulfate (HS) side chains of proteoglycans, is associated with progression and poor prognosis of many cancers which makes it an attractive drug target in cancer therapeutics. METHODS: In the present work, we report the in vitro screening of a library of 150 small molecules with the scaffold bearing quinolones, oxazines, benzoxazines, isoxazoli(di)nes, pyrimidinones, quinolines, benzoxazines, and 4-thiazolidinones, thiadiazolo[3,2-a]pyrimidin-5-one, 1,2,4-triazolo-1,3,4-thiadiazoles, and azaspiranes against the enzymatic activity of human heparanase. The identified lead compounds were evaluated for their heparanase-inhibiting activity using sulfate [35S] labeled extracellular matrix (ECM) deposited by cultured endothelial cells. Further, anti-invasive efficacy of lead compound was evaluated against hepatocellular carcinoma (HepG2) and Lewis lung carcinoma (LLC) cells. RESULTS: Among the 150 compounds screened, we identified 1,2,4-triazolo-1,3,4-thiadiazoles bearing compounds to possess human heparanase inhibitory activity. Further analysis revealed 2,4-Diiodo-6-(3-phenyl-[1, 2, 4]triazolo[3,4-b][1, 3, 4]thiadiazol-6yl)phenol (DTP) as the most potent inhibitor of heparanase enzymatic activity among the tested compounds. The inhibitory efficacy was demonstrated by a colorimetric assay and further validated by measuring the release of radioactive heparan sulfate degradation fragments from [35S] labeled extracellular matrix. Additionally, lead compound significantly suppressed migration and invasion of LLC and HepG2 cells with IC50 value of ~5 μM. Furthermore, molecular docking analysis revealed a favourable interaction of triazolo-thiadiazole backbone with Asn-224 and Asp-62 of the enzyme. CONCLUSIONS: Overall, we identified biologically active heparanase inhibitor which could serve as a lead structure in developing compounds that target heparanase in cancer

    Trisubstituted-imidazoles induce apoptosis in human breast cancer cells by targeting the oncogenic PI3K/Akt/mTOR signaling pathway

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    Overactivation of PI3K/Akt/mTOR is linked with carcinogenesis and serves a potential molecular therapeutic target in treatment of various cancers. Herein, we report the synthesis of trisubstituted-imidazoles and identified 2-chloro-3-(4, 5-diphenyl-1H-imidazol-2-yl) pyridine (CIP) as lead cytotoxic agent. Naïve Base classifier model of in silico target prediction revealed that CIP targets RAC-beta serine/threonine-protein kinase which comprises the Akt. Furthermore, CIP downregulated the phosphorylation of Akt, PDK and mTOR proteins and decreased expression of cyclin D1, Bcl-2, survivin, VEGF, procaspase-3 and increased cleavage of PARP. In addition, CIP significantly downregulated the CXCL12 induced motility of breast cancer cells and molecular docking calculations revealed that all compounds bind to Akt2 kinase with high docking scores compared to the library of previously reported Akt2 inhibitors. In summary, we report the synthesis and biological evaluation of imidazoles that induce apoptosis in breast cancer cells by negatively regulating PI3K/Akt/mTOR signaling pathway

    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
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