62 research outputs found

    Benzyl Isothiocyanate potentiates p53 signaling and antitumor effects against breast cancer through activation of p53-LKB1 and p73-LKB1 axes.

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    Functional reactivation of p53 pathway, although arduous, can potentially provide a broad-based strategy for cancer therapy owing to frequent p53 inactivation in human cancer. Using a phosphoprotein-screening array, we found that Benzyl Isothiocynate, (BITC) increases p53 phosphorylation in breast cancer cells and reveal an important role of ERK and PRAS40/MDM2 in BITC-mediated p53 activation. We show that BITC rescues and activates p53-signaling network and inhibits growth of p53-mutant cells. Mechanistically, BITC induces p73 expression in p53-mutant cells, disrupts the interaction of p73 and mutant-p53, thereby releasing p73 from sequestration and allowing it to be transcriptionally active. Furthermore, BITC-induced p53 and p73 axes converge on tumor-suppressor LKB1 which is transcriptionally upregulated by p53 and p73 in p53-wild-type and p53-mutant cells respectively; and in a feed-forward mechanism, LKB1 tethers with p53 and p73 to get recruited to p53-responsive promoters. Analyses of BITC-treated xenografts using LKB1-null cells corroborate in vitro mechanistic findings and establish LKB1 as the key node whereby BITC potentiates as well as rescues p53-pathway in p53-wild-type as well as p53-mutant cells. These data provide first in vitro and in vivo evidence of the integral role of previously unrecognized crosstalk between BITC, p53/LKB1 and p73/LKB1 axes in breast tumor growth-inhibition

    Impact Analysis of False Data Injection Attack on Smart Grid State Estimation Under Random Packet Losses

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    Supervisory control and data acquisition (SCADA) system has been widely used in traditional power systems for operation and control. As increasingly more ICT technologies are deployed to improve the smartness of the power grid, cyber security is becoming an important issue in the development of smart grids, for example, false data injection attack (FDIA) poses a serious threat. The paper analyzes the impact of false data injection attack on smart grid state estimation under random packet losses. First, a measurement model of power grids under random packet loss is established, and an attack vector range that can fool the attack detector is acquired. Then, a mean square error matrix of weighted least squares estimation is proposed, taking into account potential false data injection attacks. A IEEE-14 nodes system is used to evaluate the performance of the weighted least squares state estimation under three different scenarios, namely false data injection attack only, random packet loss only, and under both random packet loss and false data injection attack

    Activation of tumor suppressor LKB1 by honokiol abrogates cancer stem-like phenotype in breast cancer via inhibition of oncogenic Stat3

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    Tumor suppressor and upstream master kinase Liver kinase B1 (LKB1) plays a significant role in suppressing cancer growth and metastatic progression. We show that low-LKB1 expression significantly correlates with poor survival outcome in breast cancer. In line with this observation, loss-of-LKB1 rendered breast cancer cells highly migratory and invasive, attaining cancer stem cell-like phenotype. Accordingly, LKB1-null breast cancer cells exhibited an increased ability to form mammospheres and elevated expression of pluripotency-factors (Oct4, Nanog and Sox2), properties also observed in spontaneous tumors in Lkb1-/- mice. Conversely, LKB1-overexpression in LKB1-null cells abrogated invasion, migration and mammosphere-formation. Honokiol (HNK), a bioactive molecule from Magnolia grandiflora increased LKB1 expression, inhibited individual cell-motility and abrogated the stem-like phenotype of breast cancer cells by reducing the formation of mammosphere, expression of pluripotency-factors and aldehyde dehydrogenase activity. LKB1, and its substrate, AMP-dependent protein kinase (AMPK) are important for HNK-mediated inhibition of pluripotency factors since LKB1-silencing and AMPK-inhibition abrogated, while LKB1-overexpression and AMPK-activation potentiated HNK's effects. Mechanistic studies showed that HNK inhibited Stat3-phosphorylation/activation in an LKB1-dependent manner, preventing its recruitment to canonical binding-sites in the promoters of Nanog, Oct4 and Sox2. Thus, inhibition of the coactivation-function of Stat3 resulted in suppression of expression of pluripotency factors. Further, we showed that HNK inhibited breast tumorigenesis in mice in an LKB1-dependent manner. Molecular analyses of HNK-treated xenografts corroborated our in vitro mechanistic findings. Collectively, these results present the first in vitro and in vivo evidence to support crosstalk between LKB1, Stat3 and pluripotency factors in breast cancer and effective anticancer modulation of this axis with HNK treatment

    Chronic pancreatitis: Pediatric and adult cohorts show similarities in disease progress despite different risk factors

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    Objectives: To investigate the natural history of chronic pancreatitis (CP), patients in the North American Pancreatitis Study2 (NAPS2, adults) and INternational Study group of Pediatric Pancreatitis: In search for a cuRE (INSPPIRE, pediatric) were compared. Methods: Demographics, risk factors, disease duration, management and outcomes of 224 children and 1,063 adults were compared using appropriate statistical tests for categorical and continuous variables. Results: Alcohol was a risk in 53% of adults and 1% of children (p<0.0001); tobacco in 50% of adults and 7% of children (p<0.0001). Obstructive factors were more common in children (29% vs 19% in adults, p=0.001). Genetic risk factors were found more often in children. Exocrine pancreatic insufficiency was similar (children 26% vs adult 33%, p=0.107). Diabetes was more common in adults than children (36% vs 4% respectively, p<0.0001). Median emergency room visits, hospitalizations, and missed days of work/school were similar across the cohorts. As a secondary analysis, NAPS2 subjects with childhood onset (NAPS2-CO) were compared to INSPPIRE subjects. These two cohorts were more similar than the total INSPPIRE and NAPS2 cohorts, including for genetic risk factors. The only risk factor significantly more common in the NAPS2-CO cohort compared with the INSPPIRE cohort was alcohol (9% NAPS2-CO vs 1% INSPPIRE cohorts, p=0.011). Conclusions: Despite disparity in age of onset, children and adults with CP exhibit similarity in demographics, CP treatment, and pain. Differences between groups in radiographic findings and diabetes prevalence may be related to differences in risk factors associated with disease and length of time of CP

    Interrogation of the perturbed gut microbiota in gouty arthritis patients through in silico metabolic modeling

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    Recent studies have shown perturbed gut microbiota associated with gouty arthritis, a metabolic disease characterized by an imbalance between uric acid production and excretion. To mechanistically investigate altered microbiota metabolism associated with gout disease, 16S rRNA gene amplicon sequence data from stool samples of gout patients and healthy controls were computationally analyzed through bacterial community metabolic models. Patient-specific community models constructed with the metagenomics modeling pipeline, mgPipe, were used to perform k-means clustering of samples according to their metabolic capabilities. The clustering analysis generated statistically significant partitioning of samples into a Bacteroides-dominated, high gout cluster and a Faecalibacterium-elevated, low gout cluster. The high gout cluster was predicted to allow elevated synthesis of the amino acids D-alanine and L-alanine and byproducts of branched-chain amino acid catabolism, while the low gout cluster allowed higher production of butyrate, the sulfur-containing amino acids L-cysteine and L-methionine, and the L-cysteine catabolic product H2S. By expanding the capabilities of mgPipe to provide taxa-level resolution of metabolite exchange rates, acetate, D-lactate and succinate exchanged from Bacteroides to Faecalibacterium were predicted to enhance butyrate production in the low gout cluster. Model predictions suggested that sulfur-containing amino acid metabolism generally and H2S more specifically could be novel gout disease markers

    Chemical Derivatization Processes Applied to Amine Determination in Samples of Different Matrix Composition

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    Differences in Age at Onset of Symptoms, and Effects of Genetic Variants, in Patients With Early- vs Late-Onset Idiopathic Chronic Pancreatitis in a North American Cohort

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    Background & Aims Idiopathic chronic pancreatitis (ICP) is the second most common subtype of CP. In 1994, researchers reported the bimodal age at onset of ICP symptoms: early-onset ICP (EO-ICP; median age, 19.2 years) and late-onset ICP (LO-ICP; median age, 56.2 years). Ages of onset and clinical features of ICP differed from those of alcohol-related CP (ACP). However, variants in PRSS1 had not yet been associated with ICP. We reexamined ages of onset of ICP in a large, North American cohort of patients, and investigated the effects of genetic factors and alcohol use in patients with EO-ICP, LO-ICP, or ACP. Methods We performed a cross-sectional analysis of patients with CP of European ancestry enrolled in the North American Pancreatitis Study 2 studies, a prospective study of 1195 patients with CP from 26 centers in the United States from August 2000 through December 2014. We compared age at onset of symptoms for 130 patients with CP who were lifetime abstainers from alcohol (61 patients with early onset and 69 patients with late onset), 308 light to moderate alcohol drinkers with CP, and 225 patients with ACP and heavy to very heavy alcohol use. DNA from available patients was analyzed for variants associated with CP in SPINK1, CFTR, and CTRC. The Kruskal-Wallis test was used to compare continuous variables across groups and based on genetic variants. Results Median ages at onset of symptoms were 20 years for patients with EO-ICP and no alcohol use, 58 years for patients with LO-ICP and no alcohol use, 47 years for light to moderate alcohol drinkers with CP, and 44 years for patients with ACP. A higher proportion of patients with EO-ICP had constant pain (65%) than patients with LO-ICP (31%) (P=.04). A higher proportion of patients with ACP had pseudocysts (43%) than patients with EO-ICP (11%) (P=.001). A higher proportion of patients with EO-ICP had pathogenic variants in SPINK1, CFTR, or CTRC (49%) than patients with LO-ICP (23%), light to moderate alcohol drinking with CP (26%), or ACP (23%) (P=.001). Among patients with variants in SPINK1, those with EO-ICP had onset of symptoms at a median age of 12 years, and light to moderate alcohol drinkers with CP had an age at onset of 24 years. Among patients with variants in CFTR, light to moderate alcohol drinkers had an age at onset of symptoms of 41 years, but this variant did not affect age at onset of EO-ICP or ACP. Conclusions We confirmed previously reported ages at onset of symptoms for EO-ICP and LO-ICP in a North American cohort. We found differences in clinical features among patients with EO-ICP, LO-ICP, and ACP. Almost half of patients with EO-ICP have genetic variants associated with CP, compared to about one-quarter of patients with LO-CP or ACP. Genetic variants affect ages at onset of symptoms in some groups
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