16 research outputs found

    Annexin A2 is a novel Cellular Redox Regulatory Protein involved in Tumorigenesis

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    Annexins are a structurally related family of calcium and phospholipid-binding proteins that are involved in the regulation of a wide range of molecular and cellular processes. Annexin A2 is unique among the annexins in that it possesses redox sensitive cysteine(s). The ubiquitous and abundant expression of ANXA2 in cells and its reactivity with hydrogen peroxide led us to hypothesize that this protein could play a role in cellular redox regulation. Here we show that ANXA2 protein levels are induced by hydrogen peroxide. Furthermore, depletion of ANXA2 resulted in the elevation of cellular reactive oxygen species (ROS) upon oxidative stress, increased activation of the ROS-induced pro-apoptotic kinases, JNK, p38 and Akt and elevated sensitivity to ROS-mediated cellular damage/death. ANXA2-null mice showed significantly elevated protein oxidation in the liver and lung tissues compared to WT mice. ANXA2 depleted cancer cells showed enhanced cellular protein oxidationconcomitant with decreased tumor growth compared to control cancer cells andboth the oxidation of cellular proteins and tumor growth deficit werereversed by the antioxidant N-acetyl cysteine, indicating that ANXA2 plays akey role in the regulation of cellular redox during tumorigenesis. Ex-vivo human cancer studies showed that up-regulation of the reduced form of ANXA2 is associated with protection of the tumor proteins from oxidation. In summary, our results indicate that ANXA2 plays an important role incellular redox regulation by protecting cells from oxidative stress, aneffect that is particularly important during tumorigenesis

    MicroRNA profiling study reveals MIR-150 in association with metastasis in nasopharyngeal carcinoma

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    © 2017 The Author(s). MicroRNAs (miRNAs) are small non-coding RNAs that play a crucial role in pathogenesis of human cancers. Several miRNAs have been shown to involve in nasopharyngeal carcinoma (NPC) pathogenesis through alteration of gene networks. A global view of the miRNA expression profile of clinical specimens would be the best way to screen out the possible miRNA candidates that may be involved in disease pathogenesis. In this study, we investigated the expression profiles of miRNA in formalin-fixed paraffin-embedded tissues from patients with undifferentiated NPC versus non-NPC controls using a miRNA real-time PCR platform, which covered a total of 95 cancer-related miRNAs. Hierarchical cluster analysis revealed that NPC and non-NPC controls were clearly segregated. Promisingly, 10 miRNA candidates were differentially expressed. Among them, 9 miRNAs were significantly up-regulated of which miR-205 and miR-196a showed the most up-regulated in NPC with the highest incidence percentage of 94.1% and 88.2%, respectively, while the unique down-regulated miR-150 was further validated in patient sera. Finally, the in vitro gain-of-function and loss-of-function assays revealed that miR-150 can modulate the epithelial-mesenchymal-transition property in NPC/HK-1 cells and led to the cell motility and invasion. miR-150 may be a potential biomarker for NPC and plays a critical role in NPC tumourigenesis.Link_to_subscribed_fulltex

    Clinical and manometric evaluations of anorectal function in patients after transanal endorectal pull-through operation for Hirschsprung's disease: A multicentre study

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    © 2015 College of Surgeons of Hong Kong. Aim: Transanal endorectal pull-through (TEPT) operation is one the most popular operations for Hirschsprung's disease. This aim of the present study was to evaluate its outcome by clinical and manometric assessments. Patients and Methods: This study was a multicentred study involving all three paediatric surgical centres under the Hospital Authority in Hong Kong. All patients, over the age of 3years, who had undergone primary TEPT operation for more than 1year, were included in the present study. Clinical evaluation with bowel function score (BFS) and anorectomanometry were carried out. A BFS >18 and sphincter resting pressure between 30mmHg and 60mmHg were considered normal. Those with concomitant anorectal/neurological anomaly or who could not cooperate were excluded. Results: A total of 37 patients were enrolled in this study. The median age was 60months (range: 36-144months), and the median age at the time of operation was 3months (range: 0.5-60months). With respect to functional outcomes, six patients (16.2 per cent) suffered from constipation, but more than two-thirds of patients had satisfactory stool consistency, as well as frequency. Sixteen patients (43.2 per cent) had no report of any soiling. For the BFS, 26 patients had a BFS above 18, with the median value being 16 (range: 7-20). Manometric assessment revealed that 27 patients (72.9 per cent) had sphincteric resting pressure within the normal value, and the median value was 45mmHg (range: 14-79mmHg). Rectoanal inhibitory reflex was present in six patients (16.2 per cent), and the median value for the volume of air to elicit the first anal sensation was 41mL (range: 18-126mL). Using univariate analysis, long segment disease was identified as a risk factor for developing soiling of more than two times per week [relative risk (RR): 1.87, 95 per cent confidence interval (CI):1.03-2.22, P=0.05], whereas the creation of stoma (RR: 1.69, 95 per cent CI: 1.41-2.14, P=0.04) and occurrence of postoperative enterocolitis (RR: 1.58, 95 per cent CI: 1.36-1.0, P=0.04) were risk factors for abnormal bowel function score. There was no significant risk factor identified for abnormal manometric results. Lastly, patients with abnormal sphincter resting pressure detected in the anorectomanometry study were also more likely to have an abnormal BFS. Conclusion: Most patients have satisfactory clinical and manometric outcomes after primary TEPT operation. Anorectomanometry findings can predict clinical outcomes. Patients with long segment disease, development of enterocolitis and stoma creation before operation will need more attention, as they are prone to develop abnormal bowel function. Early interventions, such as manometric assessment and proper bowel management, are recommended in order to correct bowel dysfunction, as well enabling patients to have a better quality of life.Link_to_subscribed_fulltex

    Molecular-level analysis of the serum antibody repertoire in young adults before and after seasonal influenza vaccination

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    Molecular understanding of serological immunity to influenza has been confounded by the complexity of the polyclonal antibody response in humans. Here we used high-resolution proteomics analysis of immunoglobulin (referred to as Ig-seq) coupled with high-throughput sequencing of transcripts encoding B cell receptors (BCR-seq) to quantitatively determine the antibody repertoire at the individual clonotype level in the sera of young adults before and after vaccination with trivalent seasonal influenza vaccine. The serum repertoire comprised between 40 and 147 clonotypes that were specific to each of the three monovalent components of the trivalent influenza vaccine, with boosted pre-existing clonotypes accounting for ~60% of the response. An unexpectedly high fraction of serum antibodies recognized both the H1 and H3 monovalent vaccines. Recombinant versions of these H1 + H3 cross-reactive antibodies showed broad binding to hemagglutinins (HAs) from previously circulating virus strains; several of these antibodies, which were prevalent in the serum of multiple donors, recognized the same conserved epitope in the HA head domain. Although the HA-head-specific H1 + H3 antibodies did not show neutralization activity in vitro, they protected mice against infection with the H1N1 and H3N2 virus strains when administered before or after challenge. Collectively, our data reveal unanticipated insights regarding the serological response to influenza vaccination and raise questions about the added benefits of using a quadrivalent vaccine instead of a trivalent vaccine

    Risk stratification and screening for coronary artery disease in asymptomatic patients with diabetes mellitus

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    International collaboration to assess the risk of Guillain Barre Syndrome following Influenza A (H1N1) 2009 monovalent vaccines

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    <p>Background: The global spread of the 2009 novel pandemic influenza A (H1N1) virus led to the accelerated production and distribution of monovalent 2009 Influenza A (H1N1) vaccines (pH1N1). This pandemic provided the opportunity to evaluate the risk of Guillain-Barre syndrome (GBS), which has been an influenza vaccine safety concern since the swine flu pandemic of 1976, using a common protocol among high and middle-income countries. The primary objective of this project was to demonstrate the feasibility and utility of global collaboration in the assessment of vaccine safety, including countries both with and without an established infrastructure for vaccine active safety surveillance. A second objective, included a priori, was to assess the risk of GBS following pH1N1 vaccination.</p><p>Methods: The primary analysis used the self-controlled case series (SCCS) design to estimate the relative incidence (RI) of GBS in the 42 days following vaccination with pH1N1 vaccine in a pooled analysis across databases and in analysis using a meta-analytic approach.</p><p>Results: We found a relative incidence of GBS of 2.42(95% CI 1.58-3.72) in the 42 days following exposure to pH1N1 vaccine in analysis of pooled data and 2.09(95% CI 1.28-3.42) using the meta-analytic approach.</p><p>Conclusions: This study demonstrates that international collaboration to evaluate serious outcomes using a common protocol is feasible. The significance and consistency of our findings support a conclusion of an association between 2009 H1N1 vaccination and GBS. Given the rarity of the event the relative incidence found does not provide evidence in contradiction to international recommendations for the continued use of influenza vaccines. (C) 2013 Elsevier Ltd. All rights reserved.</p>

    Association analysis identifies 65 new breast cancer risk loci

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