Bortezomib combines with suberoylanilide hydroxamic acid (SAHA) to synergistically induce caspase-dependent apoptosis and blocks SAHA's activation of EBV lytic cycle in nasopharyngeal carcinoma

Poster Session 1 - Vaccines and Anti-Viral Therapeutics: no. 3.13Histone deacetylase inhibitor, suberoylanilide hydroxamic acid (SAHA), could induce Epstein-Barr virus (EBV) lytic cycle and apoptosis in EBV-positive nasopharyngeal carcinoma (NPC) cells. In this study, we investigated the effects of combining a proteasome inhibitor, bortezomib, with SAHA in the treatment of NPC cells. Synergistic killing of a panel of EBV-positive NPC cells upon treatment with various combinations of bortezomib (0, 7.5, 15, 30, 60 and 120 nM) and SAHA (0, 0.625, 1.25, 2.5, 5 and 10 uM) was demonstrated by MTT assay and isobologram analysis. The synergistic killing was due to apoptosis as demonstrated by markedly increased sub-G1, annexin V-positive and TUNEL-positive cell populations. Strong proteolytic cleavage of PARP, caspase-3, -7 and -9 and increased reactive oxygen species …postprin

Identification of Novel Small Organic Compounds with Diverse Structures for the Induction of Epstein-Barr Virus (EBV) Lytic Cycle in EBV-Positive Epithelial Malignancies

Phorbol esters, which are protein kinase C (PKC) activators, and histone deacetylase (HDAC) inhibitors, which cause enhanced acetylation of cellular proteins, are the main classes of chemical inducers of Epstein-Barr virus (EBV) lytic cycle in latently EBV-infected cells acting through the PKC pathway. Chemical inducers which induce EBV lytic cycle through alternative cellular pathways may aid in defining the mechanisms leading to lytic cycle reactivation and improve cells’ responsiveness towards lytic induction. We performed a phenotypic screening on a chemical library of 50,240 novel small organic compounds to identify novel class(es) of strong inducer(s) of EBV lytic cycle in gastric carcinoma (GC) and nasopharyngeal carcinoma (NPC) cells. Five hit compounds were selected after three successive rounds of increasingly stringent screening. All five compounds are structurally diverse from each other and distinct from phorbol esters or HDAC inhibitors. They neither cause hyperacetylation of histone proteins nor significant PKC activation at their working concentrations, suggesting that their biological mode of action are distinct from that of the known chemical inducers. Two of the five compounds with rapid lytic-inducing action were further studied for their mechanisms of induction of EBV lytic cycle. Unlike HDAC inhibitors, lytic induction by both compounds was not inhibited by rottlerin, a specific inhibitor of PKCδ. Interestingly, both compounds could cooperate with HDAC inhibitors to enhance EBV lytic cycle induction in EBV-positive epithelial cancer cells, paving way for the development of strategies to increase cells’ responsiveness towards lytic reactivation. One of the two compounds bears structural resemblance to iron chelators and the other strongly activates the MAPK pathways. These structurally diverse novel organic compounds may represent potential new classes of chemicals that can be used to investigate any alternative mechanism(s) leading to EBV lytic cycle reactivation from latency.published_or_final_versio

Chronic benign neutropenia among Chinese children

Objective. To delineate the clinical behaviour of chronic benign neutropenia in Chinese children in Hong Kong. Design. Retrospective study. Setting. University teaching hospital, Hong Kong. Patients. All infants and children with absolute neutrophil count of 1.5 × 109 /L or lower for more than 3 months. Main outcome measures. Development of significant infection, and achievement of remission. Results. Twenty-four children with chronic benign neutropenia were identified between 1992 and 2001. Their median age of diagnosis was 9 months. The mean (standard deviation) initial absolute neutrophil count was 0.28 × 109 /L (0.24 × 109 /L). Twenty-three patients presented with infection. Of the 19 patients tested, four (21%) were positive for anti-neutrophil antibodies. Bone marrow examination was performed in 17 patients: nine had normal results, but six showed evidence of peripheral consumption, one showed late maturation arrest at band stage, and one showed phagocytosis of myeloid cells by histiocytes. The overall hospitalised infection rate was 51.6 episodes per 1000 patient-months. Ten percent of cases were considered 'significant' infections and required hospital admission with either surgical intervention or intravenous therapy (antibiotics or fluid replacement). In the first year of diagnosis, more than 80% of patients had their lowest absolute neutrophil count (mean, 0.16 × 109 /L; standard deviation, 0.11 × 109 /L). Granulocyte-colony stimulating factor was used to treat three patients and induced transient elevation of absolute neutrophil count in all three. The projected remission rate was 55.4% at 3 years. Even for those with persistent disease, there was significant recovery in absolute neutrophil count to a mean of 0.5 × 109 /L (P<0.01). Conclusions. Patients with chronic benign neutropenia experienced a relatively benign clinical course regardless of their remission status. Only a small proportion of patients developed significant infections. A multi-centre prospective study may help identify predictive factors of remission.published_or_final_versio

HLA alleles associated with asparaginase hypersensitivity in Chinese children

Asparaginase is an important drug to treat childhood haematological malignancies. Data on the association between human leukocyte antigens (HLA) and asparaginase hypersensitivity among Chinese are lacking. We conducted a retrospective study to identify HLA alleles associated with asparaginase hypersensitivity among Chinese children with acute lymphoblastic leukaemia (ALL), mixed phenotype leukaemia and non-Hodgkin lymphoma (NHL), who received asparaginases with HLA typing performed between 2009 and 2019. 107 Chinese patients were analysed. 66.3% (71/107) developed hypersensitivity to at least one of the asparaginases. HLA-B*46:01 (OR 3.8, 95% CI 1.4-10.1, p < 0.01) and DRB1*09:01 (OR 4.3, 95% CI 1.6-11.4, p < 0.01) were significantly associated with L-asparaginase hypersensitivities, which remained significant after adjustment for age, gender and B cell ALL [HLA-B*46:01 (adjusted OR 3.5, 95% 1.3-10.5, p = 0.02) and DRB1*09:01 (OR 4.4, 95% CI 1.6-13.3, p < 0.01)]

Aesthetics by Numbers: Links between Perceived Texture Qualities and Computed Visual Texture Properties.

Our world is filled with texture. For the human visual system, this is an important source of information for assessing environmental and material properties. Indeed-and presumably for this reason-the human visual system has regions dedicated to processing textures. Despite their abundance and apparent relevance, only recently the relationships between texture features and high-level judgments have captured the interest of mainstream science, despite long-standing indications for such relationships. In this study, we explore such relationships, as these might be used to predict perceived texture qualities. This is relevant, not only from a psychological/neuroscience perspective, but also for more applied fields such as design, architecture, and the visual arts. In two separate experiments, observers judged various qualities of visual textures such as beauty, roughness, naturalness, elegance, and complexity. Based on factor analysis, we find that in both experiments, ~75% of the variability in the judgments could be explained by a two-dimensional space, with axes that are closely aligned to the beauty and roughness judgments. That a two-dimensional judgment space suffices to capture most of the variability in the perceived texture qualities suggests that observers use a relatively limited set of internal scales on which to base various judgments, including aesthetic ones. Finally, for both of these judgments, we determined the relationship with a large number of texture features computed for each of the texture stimuli. We find that the presence of lower spatial frequencies, oblique orientations, higher intensity variation, higher saturation, and redness correlates with higher beauty ratings. Features that captured image intensity and uniformity correlated with roughness ratings. Therefore, a number of computational texture features are predictive of these judgments. This suggests that perceived texture qualities-including the aesthetic appreciation-are sufficiently universal to be predicted-with reasonable accuracy-based on the computed feature content of the textures

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

Five insights from the Global Burden of Disease Study 2019

The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 provides a rules-based synthesis of the available evidence on levels and trends in health outcomes, a diverse set of risk factors, and health system responses. GBD 2019 covered 204 countries and territories, as well as first administrative level disaggregations for 22 countries, from 1990 to 2019. Because GBD is highly standardised and comprehensive, spanning both fatal and non-fatal outcomes, and uses a mutually exclusive and collectively exhaustive list of hierarchical disease and injury causes, the study provides a powerful basis for detailed and broad insights on global health trends and emerging challenges. GBD 2019 incorporates data from 281 586 sources and provides more than 3.5 billion estimates of health outcome and health system measures of interest for global, national, and subnational policy dialogue. All GBD estimates are publicly available and adhere to the Guidelines on Accurate and Transparent Health Estimate Reporting. From this vast amount of information, five key insights that are important for health, social, and economic development strategies have been distilled. These insights are subject to the many limitations outlined in each of the component GBD capstone papers.Peer reviewe

Kinetics Of Epstein-Barr Virus (EBV) Latent And Lytic Protein Expression In EBV-Positive Burkitt, Epithelial And Lymphoblastoid Cells Upon Induction Of Lytic Cycle

Poster session: Virus ReplicationEpstein Barr virus (EBV) has latent and lytic infection cycles. We hypothesize that a subset of EBV latent proteins may be expressed and have functional roles in lytic cycle. We examined by Western blotting the expression of three latent proteins (EBNA1, EBNA2 and LMP1) and three lytic proteins (Zta, VCA-p18 and gp350/220) in Akata (Burkitt), AGS-BX1 (gastric carcinoma) and B95-8 (lymphoblastoid) cells at defined intervals between zero and 72 hours after lytic cycle activation with anti-IgG, suberoylanilide hydroxamic acid and TPA/sodium butyrate, respectively. EBNA1 was stably expressed in lytic cycle at the same level as that of latent cycle in all cell lines. EBNA2 was neither expressed in latent nor lytic phases of AGS-BX1 whilst it was expressed in Akata from 24 hours but downregulated in B95-8 from 48 hours post-induction. LMP1 was expressed in Akata from 16 hours and upregulated in B95-8 also from 16 hours but was never expressed in AGS-BX1. Zta was induced in Akata at 2 hours reaching maximal level at 24 hours whilst it was upregulated or induced in AGS-BX1 and B95-8 at 8 hours reaching maximal level at 48-72 hours postinduction. VCA-p18 and gp350/220 were induced at 8 hours in both Akata and AGS-BX1 rising to maximal level at 72 hours post-induction. These data suggest that EBNA2 and LMP1 may have function in lytic cycle of B but not epithelial cells. Simultaneous activation of Zta, VCA-p18 and gp350/220 in AGS-BX1 cells indicates different regulation of lytic cycle between epithelial and B cells