64 research outputs found

    Rice blast fungus sequenced

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    In vitro and in vivo anticancer studies of 2'-hydroxy chalcone derivatives exhibit apoptosis in colon cancer cells by HDAC inhibition and cell cycle arrest

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    Considering the therapeutic values of bioflavonoids in colon cancer treatment, six 2′-hydroxy chalcones (C1-C6) were synthesized, characterized and screened for in vitro cytotoxicity on human colon carcinoma (HCT116) and African green monkey kidney epithelial cells (Vero). Only C5 showed selective cytotoxicity against HCT116 cells. Other potent cytotoxic compounds were C1, C2 and C3. Further screening included enzyme inhibition studies on histone deacetylase (HDAC) enzyme where C1 showed lowest IC50 value (105.03 µM). Based on cytotoxicity data C1, C2 and C3 were selected for further in vitro mechanistic studies, namely apoptotic studies (Acridine or- ange/Ethidium bromide (AO/EB) and Annexin V), cell cycle analysis using propidium iodide (PI) stain and in vivo anticancer efficacy in 1,2-dimethyl hydrazine (DMH) induced colorectal carcinoma in Wistar rats. The com- pounds induced apoptosis in more than 30 % cells in AO/EB and Annexin V staining. They also showed cell cycle arrest in G2/M phase with PI staining. They showed a significant reduction in aberrant crypt foci formation and adenocarcinoma count along with a significant (p<0.05) reduction in TNF-α levels as compared to DMH control at 100 mg/kg dose. Thus, it can be concluded that the synthesized 2′-hydroxychalcones were effective against colon adenocarcinoma in in vitro and in vivo studies

    Monoclonal Antibodies Recognizing the Non-Tandem Repeat Regions of the Human Mucin MUC4 in Pancreatic Cancer

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    The MUC4 mucin is a high molecular weight, membrane-bound, and highly glycosylated protein. It is a multi-domain protein that is putatively cleaved into a large mucin-like subunit (MUC4α) and a C-terminal growth-factor like subunit (MUC4β). MUC4 plays critical roles in physiological and pathological conditions and is aberrantly overexpressed in several cancers, including those of the pancreas, cervix, breast and lung. It is also a potential biomarker for the diagnosis, prognosis and progression of several malignancies. Further, MUC4 plays diverse functional roles in cancer initiation and progression as evident from its involvement in oncogenic transformation, proliferation, inhibition of apoptosis, motility and invasion, and resistance to chemotherapy in human cancer cells. We have previously generated a monoclonal antibody 8G7, which is directed against the TR region of MUC4, and has been extensively used to study the expression of MUC4 in several malignancies. Here, we describe the generation of anti-MUC4 antibodies directed against the non-TR regions of MUC4. Recombinant glutathione-S-transferase (GST)-fused MUC4α fragments, both upstream (MUC4α-N-Ter) and downstream (MUC4α-C-Ter) of the TR domain, were used as immunogens to immunize BALB/c mice. Following cell fusion, hybridomas were screened using the aforementioned recombinant proteins ad lysates from human pancreatic cell lines. Three anti MUC4α-N-Ter and one anti-MUC4α-C-Ter antibodies were characterized by several inmmunoassays including enzyme-linked immunosorbent assay (ELISA), immunoblotting, immunofluorescene, flow cytometry and immunoprecipitation using MUC4 expressing human pancreatic cancer cell lines. The antibodies also reacted with the MUC4 in human pancreatic tumor sections in immunohistochemical analysis. The new domain-specific anti-MUC4 antibodies will serve as important reagents to study the structure-function relationship of MUC4 domains and for the development of MUC4-based diagnostics and therapeutics

    Molecular association of glucose-6- phosphate isomerase and pyruvate kinase M2 with glyceraldehyde-3-phosphate dehydrogenase in cancer cells

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    Background: For a long time cancer cells are known for increased uptake of glucose and its metabolization through glycolysis. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a key regulatory enzyme of this pathway and can produce ATP through oxidative level of phosphorylation. Previously, we reported that GAPDH purified from a variety of malignant tissues, but not from normal tissues, was strongly inactivated by a normal metabolite, methylglyoxal (MG).Molecular mechanism behind MG mediated GAPDH inhibition in cancer cells is not well understood. Methods: GAPDH was purified from Ehrlich ascites carcinoma (EAC) cells based on its enzymatic activity. GAPDH associated proteins in EAC cells and 3-methylcholanthrene (3MC) induced mouse tumor tissue were detected by mass spectrometry analysis and immunoprecipitation (IP) experiment, respectively. Interacting domains of GAPDH and its associated proteins were assessed by in silico molecular docking analysis. Mechanism of MG mediated GAPDH inactivation in cancer cells was evaluated by measuring enzyme activity, Circular dichroism (CD) spectroscopy, IP and mass spectrometry analyses. Result: Here, we report that GAPDH is associated with glucose-6-phosphate isomerase (GPI) and pyruvate kinase M2 (PKM2) in Ehrlich ascites carcinoma (EAC) cells and also in 3-methylcholanthrene (3MC) induced mouse tumor tissue. Molecular docking analyses suggest C-terminal domain preference for the interaction between GAPDH and GPI. However, both C and N termini of PKM2 might be interacting with the C terminal domain of GAPDH. Expression of both PKM2 and GPI is increased in 3MC induced tumor compared with the normal tissue. In presence of 1 mM MG,association of GAPDH with PKM2 or GPI is not perturbed, but the enzymatic activity of GAPDH is reduced to 26.8 ± 5 % in 3MC induced tumor and 57.8 ± 2.3 % in EAC cells. Treatment of MG to purified GAPDH complex leads to glycation at R399 residue of PKM2 only, and changes the secondary structure of the protein complex. Conclusion: PKM2 may regulate the enzymatic activity of GAPDH. Increased enzymatic activity of GAPDH in tumor cells may be attributed to its association with PKM2 and GPI. Association of GAPDH with PKM2 and GPI could be a signature for cancer cells. Glycation at R399 of PKM2 and changes in the secondary structure of GAPDH complex could be one of the mechanisms by which GAPDH activity is inhibited in tumor cells by MG

    Tumor Necrosis Factor α Inhibits Expression of the Iron Regulating Hormone Hepcidin in Murine Models of Innate Colitis

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    Background: Abnormal expression of the liver peptide hormone hepcidin, a key regulator of iron homeostasis, contributes to the pathogenesis of anemia in conditions such as inflammatory bowel disease (IBD). Since little is known about the mechanisms that control hepcidin expression during states of intestinal inflammation, we sought to shed light on this issue using mouse models. Methodology/Principal Findings: Hepcidin expression was evaluated in two types of intestinal inflammation caused by innate immune activation—dextran sulfate sodium (DSS)-induced colitis in wild-type mice and the spontaneous colitis occurring in T-bet/Rag2-deficient (TRUC) mice. The role of tumor necrosis factor (TNF) α\alpha was investigated by in vivo neutralization, and by treatment of a hepatocyte cell line, as well as mice, with the recombinant cytokine. Expression and activation of Smad1, a positive regulator of hepcidin transcription, were assessed during colitis and following administration or neutralization of TNFα\alpha. Hepcidin expression progressively decreased with time during DSS colitis, correlating with changes in systemic iron distribution. TNFα\alpha inhibited hepcidin expression in cultured hepatocytes and non-colitic mice, while TNFα\alpha neutralization during DSS colitis increased it. Similar results were obtained in TRUC mice. These effects involved a TNFα\alpha-dependent decrease in Smad1 protein but not mRNA. Conclusions/Significance: TNFα\alpha inhibits hepcidin expression in two distinct types of innate colitis, with down-regulation of Smad1 protein playing an important role in this process. This inhibitory effect of TNFα\alpha may be superseded by other factors in the context of T cell-mediated colitis given that in the latter form of intestinal inflammation hepcidin is usually up-regulated

    Interferon-driven alterations of the host’s amino acid metabolism in the pathogenesis of typhoid fever

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    Enteric fever, caused by Salmonella enterica serovar Typhi, is an important public health problem in resource-limited settings and, despite decades of research, human responses to the infection are poorly understood. In 41 healthy adults experimentally infected with wild-type S. Typhi, we detected significant cytokine responses within 12 h of bacterial ingestion. These early responses did not correlate with subsequent clinical disease outcomes and likely indicate initial host–pathogen interactions in the gut mucosa. In participants developing enteric fever after oral infection, marked transcriptional and cytokine responses during acute disease reflected dominant type I/II interferon signatures, which were significantly associated with bacteremia. Using a murine and macrophage infection model, we validated the pivotal role of this response in the expression of proteins of the host tryptophan metabolism during Salmonella infection. Corresponding alterations in tryptophan catabolites with immunomodulatory properties in serum of participants with typhoid fever confirmed the activity of this pathway, and implicate a central role of host tryptophan metabolism in the pathogenesis of typhoid fever

    Removal of the endocrine disrupter butyl benzyl phthalate from the environment

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    Butyl benzyl phthalate (BBP), an aryl alkyl ester of 1,2-benzene dicarboxylic acid, is extensively used in vinyl tiles and as a plasticizer in PVC in many commonly used products. BBP, which readily leaches from these products, is one of the most important environmental contaminants, and the increased awareness of its adverse effects on human health has led to a dramatic increase in research aimed at removing BBP from the environment via bioremediation. This review highlights recent progress in the degradation of BBP by pure and mixed bacterial cultures, fungi, and in sludge, sediment, and wastewater. Sonochemical degradation, a unique abiotic remediation technique, and photocatalytic degradation are also discussed. The degradation pathways for BBP are described, and future research directions are considered

    Electro-conductive Palmyra Fibers By In Situ Polymerization of Pyrrole

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    Palmyra (Borassus flabellifer L.) is one of the natural fruit fibers that are available in plenty. This fiber has many advantages, such as biodegradability, renewability, low density, and low cost, which offer greater opportunities to develop new applications. Imparting electrical conductivity to this fiber may open up avenues for various novel applications. In the present study, Palmyra fibers are made electro-conductive by in situ chemical polymerization of pyrrole with FeCl3 oxidant and PTSA dopant. Prepared electro-conductive fibers show average electrical resistivity 2.96 kΩ cm−1. A positive correlation is found between fiber-length and electrical resistance, whereas a negative correlation is found in between fiber-diameter and electrical resistance. FTIR study is conducted to understand the chemical interaction between lingo-cellulose and polypyrrole. Tensile properties and thermal degradation behavior of the prepared electro-conductive fibers are evaluated, and significant deterioration of both tensile properties and thermal stability is observed. Due to this reason, these electro-conductive fibers are unsuitable for mechanical processing and high-tech applications. But the response of these fibers in different pH solution is investigated, and their possible application as a pH sensor has been explored

    Corrigendum to “In situ 1,3-dipolar azide cycloaddition reaction: synthesis of functionalized D-glucose based chiral piperidine and oxazepine analogues”

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    In the 1H NMR spectrum, the coupling constants J2,3 are found to be somewhat different for 10 (8.5 Hz) and 11 (6.1 Hz). This may be due to difference in dihedral angle of the H–C2–C3–H unit (188 in 10 and 408 in 11) in the energy-minimized structures obtained using Chem. Office 6.0.
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