Histone modification enhances the effectiveness of IL-13 receptor targeted immunotoxin in murine models of human pancreatic cancer

<p>Abstract</p> <p>Background</p> <p>Interleukin-13 Receptor α2 (IL-13Rα2) is a tumor-associated antigen and target for cancer therapy. Since IL-13Rα2 is heterogeneously overexpressed in a variety of human cancers, it would be highly desirable to uniformly upregulate IL-13Rα2 expression in tumors for optimal targeting.</p> <p>Methods</p> <p>We examined epigenetic regulation of <it>IL-13Rα2 </it>in a murine model of human pancreatic cancer by Bisulfite-PCR, sequencing for DNA methylation and chromatin immunoprecipitation for histone modification. Reverse transcription-PCR was performed for examining changes in IL-13Rα2 mRNA expression after treatment with histone deacetylase (HDAC) and c-jun inhibitors. <it>In vitro </it>cytotoxicity assays and <it>in vivo </it>testing in animal tumor models were performed to determine whether HDAC inhibitors could enhance anti-tumor effects of IL-13-PE in pancreatic cancer. Mice harboring subcutaneous tumors were treated with HDAC inhibitors systemically and IL-13-PE intratumorally.</p> <p>Results</p> <p>We found that CpG sites in <it>IL-13Rα2 </it>promoter region were not methylated in all pancreatic cancer cell lines studied including IL-13Rα2-positive and IL-13Rα2-negative cell lines and normal cells. On the other hand, histones at IL-13Rα2 promoter region were highly-acetylated in IL-13Rα2-positive but much less in receptor-negative pancreatic cancer cell lines. When cells were treated with HDAC inhibitors, not only histone acetylation but also IL-13Rα2 expression was dramatically enhanced in receptor-negative pancreatic cancer cells. In contrast, HDAC inhibition did not increase IL-13Rα2 in normal cell lines. In addition, c-jun in IL-13Rα2-positive cells was expressed at higher level than in negative cells. Two types of c-jun inhibitors prevented increase of IL-13Rα2 by HDAC inhibitors. HDAC inhibitors dramatically sensitized cancer cells to immunotoxin in the cytotoxicity assay <it>in vitro </it>and increased IL-13Rα2 in the tumors subcutaneously implanted in the immunodeficient animals but not in normal mice tissues. Combination therapy with HDAC inhibitors and immunotoxin synergistically inhibited growth of not only IL-13Rα2-positive but also IL-13Rα2-negative tumors.</p> <p>Conclusions</p> <p>We have identified a novel function of histone modification in the regulation of IL-13Rα2 in pancreatic cancer cell lines <it>in vitro </it>and <it>in vivo</it>. HDAC inhibition provides a novel opportunity in designing combinatorial therapeutic approaches not only in combination with IL-13-PE but with other immunotoxins for therapy of pancreatic cancer and other cancers.</p

Profile of paediatric low vision population: a retrospective study from Nepal.

BACKGROUND: Childhood blindness and low vision have become major public health problems in developing countries. The purpose of this study was to categorise the causes of visual impairment according to aetiology and provide detailed local information on visually impaired children seeking low-vision services in a tertiary eye centre in Nepal. METHODS: A retrospective study was conducted of all visually impaired children (visual acuity of less than 6/18 in the better eye), aged less than 17 years seen in the low-vision clinic at the Sagarmatha Chaudhary Eye Hospital in Lahan between January 1, 2012 and December 31, 2013. RESULTS: Of the 558 visually impaired children, the majority were males, 356 (63.7 per cent). More than half (56.5 per cent) of the children were in the 11 to 16 years age group. Many of the low-vision children (52.9 per cent) were identified as having moderate visual impairment (visual acuity less than 6/18 to 6/60). Most children were diagnosed with childhood (36.2 per cent) or genetic (35.5 per cent) aetiology, followed by prenatal (22.2 per cent) and perinatal (6.1 per cent) aetiologies. Refractive error and amblyopia (20.1 per cent), retinitis pigmentosa (14.9 per cent) and macular dystrophy (13.4 per cent) were the most common causes of paediatric visual impairment. Nystagmus (50.0 per cent) was the most common cause of low vision in the one to five years age group, whereas refractive error and amblyopia were the major causes in the six to 10 and 11 to 16 years age group (17.6 and 22.9 per cent, respectively). Many of the children (86.0 per cent) were prescribed low-vision aids and 72.0 per cent of the low-vision aid users showed an improvement in visual acuity either at distance or near. CONCLUSION: Paediatric low vision has a negative impact on the quality of life in children. Data from this study indicate that knowledge about the local characteristics and aetiological categorisation of the causes of low vision are essential in tackling paediatric visual impairment. The findings also signify the importance of early intervention to ensure a better quality of life

Knockdown of TFIIS by RNA silencing inhibits cancer cell proliferation and induces apoptosis

<p>Abstract</p> <p>Background</p> <p>A common element among cancer cells is the presence of improperly controlled transcription. In these cells, the degree of specific activation of some genes is abnormal, and altering the aberrant transcription may therefore directly target cancer. TFIIS is a transcription elongation factor, which directly binds the transcription motor, RNA Polymerase II and allows it to read through various transcription arrest sites. We report on RNA interference of TFIIS, a transcription elongation factor, and its affect on proliferation of cancer cells in culture.</p> <p>Methods</p> <p>RNA interference was performed by transfecting siRNA to specifically knock down TFIIS expression in MCF7, MCF10A, PL45 and A549 cells. Levels of TFIIS expression were determined by the Quantigene method, and relative protein levels of TFIIS, c-myc and p53 were determined by C-ELISA. Induction of apoptosis was determined by an enzymatic Caspase 3/7 assay, as well as a non-enzymatic assay detecting cytoplasmic mono- and oligonucleosomes. A gene array analysis was conducted for effects of TFIIS siRNA on MCF7 and MCF10A cell lines.</p> <p>Results</p> <p>Knockdown of TFIIS reduced cancer cell proliferation in breast, lung and pancreatic cancer cell lines. More specifically, TFIIS knockdown in the MCF7 breast cancer cell line induced cancer cell death and increased c-myc and p53 expression whereas TFIIS knockdown in the non-cancerous breast cell line MCF10A was less affected. Differential effects of TFIIS knockdown in MCF7 and MCF10A cells included the estrogenic, c-myc and p53 pathways, as observed by C-ELISA and gene array, and were likely involved in MCF7 cell-death.</p> <p>Conclusion</p> <p>Although transcription is a fundamental process, targeting select core transcription factors may provide for a new and potent avenue for cancer therapeutics. In the present study, knockdown of TFIIS inhibited cancer cell proliferation, suggesting that TFIIS could be studied as a potential cancer target within the transcription machinery.</p

Effect of Phosphate Group Addition on the Properties of Denture Base Resins

Statement of problem Acrylic resins are prone to microbial adherence, especially by Candida albicans. Surface-charged resins alter the ionic interaction between the denture resin and Candida hyphae, and these resins are being developed as a means to reduce microbial colonization on the denture surface. Purpose The purpose of this study was to investigate the physical and mechanical properties of phosphate-containing polymethyl methacrylate resins for their suitability as a denture material. Material and methods Using PMMA with cross-linker (Lucitone 199) as a control, 4 experimental groups containing various levels of phosphate with and without cross-linker were generated. The properties examined were impact strength, fracture toughness, wettability (contact angle), and resin bonding ability to denture teeth. Impact strength was tested in the Izod configuration (n=16), and fracture toughness (n=13) was measured using the single-edge notched bend test. Wettability was determined by calculating the contact angle of water on the material surface (n=12), while ISO 1567 was used for bonding ability (n=12). The data were analyzed by 1- and 2-way ANOVA (α=.05). Results A trend of increased hydrophilicity, as indicated by lower contact angle, was observed with increased concentrations of phosphate. With regard to the other properties, no significant differences were found when compared with the control acrylic resin. Conclusions No adverse physical effect due to the addition of a phosphate-containing monomer was found in the acrylic denture resins. Additional mechanical and physical properties, biocompatibility, and clinical efficacy studies are needed to confirm the in vivo anti-Candida activity of these novel resins

Venezuelan equine encephalitis virus infection causes modulation of inflammatory and immune response genes in mouse brain

<p>Abstract</p> <p>Background</p> <p>Neurovirulent Venezuelan equine encephalitis virus (VEEV) causes lethal encephalitis in equines and is transmitted to humans by mosquitoes. VEEV is highly infectious when transmitted by aerosol and has been developed as a bio-warfare agent, making it an important pathogen to study from a military and civilian standpoint. Molecular mechanisms of VEE pathogenesis are poorly understood. To study these, the gene expression profile of VEEV infected mouse brains was investigated. Changes in gene expression were correlated with histological changes in the brain. In addition, a molecular framework of changes in gene expression associated with progression of the disease was studied.</p> <p>Results</p> <p>Our results demonstrate that genes related to important immune pathways such as antigen presentation, inflammation, apoptosis and response to virus (<it>Cxcl10</it>, <it>CxCl11</it>, <it>Ccl5</it>, <it>Ifr7</it>, <it>Ifi27 Oas1b</it>, <it>Fcerg1</it>,<it>Mif</it>, <it>Clusterin and MHC class II) </it>were upregulated as a result of virus infection. The number of over-expressed genes (>1.5-fold level) increased as the disease progressed (from 197, 296, 400, to 1086 at 24, 48, 72 and 96 hours post infection, respectively).</p> <p>Conclusion</p> <p>Identification of differentially expressed genes in brain will help in the understanding of VEEV-induced pathogenesis and selection of biomarkers for diagnosis and targeted therapy of VEEV-induced neurodegeneration.</p

Towards ultralow detection limits of aromatic toxicants in water using pluronic nanoemulsions and single-entity electrochemistry

We demonstrate a new electroanalytical technique using nanoemulsions (NEs) as a nanoextractor combined with single entity electrochemistry (SEE) to separate, preconcentrate analytes from bulk media, and even detect them in situ, enabling ultratrace level analysis. This approach is based on our hypothesis that the custom-designed NEs would enable to effectively scavenge compounds from bulk media. Herein, we use Pluronic F-127 functionalized NEs to extract, preconcentrate target analytes e.g., ferrocene derivatives as a model aromatic toxicant dissolved in the water, and employ SEE to in situ detect and quantitatively estimate analytes extracted in individual NEs. Extraction was markedly efficient to reach ∼8 orders of magnitude of preconcentration factor under the true equilibrium, thereby enabling ultratrace level analysis with a detection limit of ∼0.2 ppb. The key step to attain high sensitivity in our measurements was to modulate the total amount of added NEs respect to the total volume of bulk solution, thereby controlling the extracted amount of analytes in each NE. Our approach is readily applicable to investigate other aromatic toxicants dissolved in the water, thus detecting hazardous carcinogen, 2-aminobiphenyl in the water up to ∼0.1 ppb level. Given the excellent detection performance as well as the broad applicability for ubiquitous aromatic contaminants, the combination of NEs with SEE offers great prospects as a sensor for environmental applications

Surgical Stabilization of Femur Fractures in Post-Traumatic Hypoxemic Patients: When and Why?

Background: Post-traumatic hypoxemia can deteriorate during operative manipulations. Objectives: In the present study, criteria-based approach was applied to determine optimum conditions for femur surgery. The aim of this study was to optimize perioperative management of post-traumatic hypoxemia. Patients and Methods: In this prospective observational study, post-traumatic adults with PaO2 200 mmHg (FiO2 < 0.5, PEEP < 8 cm H2O). Results: A total of 31 adults (26 males and 5 females) with LIS of 0.1 to 2.5 (26 patients) and > 2.5 (five patients) at admission were recruited. Sixteen patients were admitted within 24 hours and 15 between 24 and 90 hours after injury. Thirteen patients were operated within 24 hours. Post-operative LIS was improved. No adverse sequels or mortality were seen. Conclusions: Appropriate surgical stabilization can be safely performed during established post-traumatic hypoxemia using a multidisciplinary approach, continuous monitoring, and serial investigations to diagnose fulminant pathology and associated injuries

Recurrent Nerve Palsy due to a Giant Vertebral Artery Aneurysm

Vertebral artery aneurysms are rare and challenging as they are usually asymptomatic and, therefore, often overlooked. We report the case of a 73-year-old man with a history of progressive dysphagia for 1 year. Computed tomography (CT) and computed tomography with angiography (CTA) of the cerebrum revealed a giant vertebral artery aneurysm compressing the medulla. Fiberoptic endoscopic evaluation of swallowing (FEES) revealed recurrent nerve paralysis. The patient was managed conservatively since the aneurysm was completely thrombosed