MYC sensitises cells to apoptosis by driving energetic demand.

The MYC oncogene is a potent driver of growth and proliferation but also sensitises cells to apoptosis, which limits its oncogenic potential. MYC induces several biosynthetic programmes and primary cells overexpressing MYC are highly sensitive to glutamine withdrawal suggesting that MYC-induced sensitisation to apoptosis may be due to imbalance of metabolic/energetic supply and demand. Here we show that MYC elevates global transcription and translation, even in the absence of glutamine, revealing metabolic demand without corresponding supply. Glutamine withdrawal from MRC-5 fibroblasts depletes key tricarboxylic acid (TCA) cycle metabolites and, in combination with MYC activation, leads to AMP accumulation and nucleotide catabolism indicative of energetic stress. Further analyses reveal that glutamine supports viability through TCA cycle energetics rather than asparagine biosynthesis and that TCA cycle inhibition confers tumour suppression on MYC-driven lymphoma in vivo. In summary, glutamine supports the viability of MYC-overexpressing cells through an energetic rather than a biosynthetic mechanism.

Intrinsic function of the peptidylarginine deiminase PADI4 is dispensable for normal haematopoiesis.

Peptidylarginine deiminases (PADIs) are strongly associated with the development of autoimmunity, neurodegeneration and cancer but their physiological roles are ill-defined. The nuclear deiminase PADI4 regulates pluripotency in the mammalian pre-implantation embryo but its function in tissue development is unknown. PADI4 is primarily expressed in the bone marrow, as part of a self-renewal-associated gene signature. It has been shown to regulate the proliferation of multipotent haematopoietic progenitors and proposed to impact on the differentiation of haematopoietic stem cells (HSCs), suggesting that it controls haematopoietic development or regeneration. Using conditional in vivo models of steady state and acute Padi4 ablation, we examined the role of PADI4 in the development and function of the haematopoietic system. We found that PADI4 loss does not significantly affect HSC self-renewal or differentiation potential upon injury or serial transplantation, nor does it lead to HSC exhaustion or premature ageing. Thus PADI4 is dispensable for cell-autonomous HSC maintenance, differentiation and haematopoietic regeneration. This work represents the first study of PADI4 in tissue development and indicates that pharmacological PADI4 inhibition may be tolerated without adverse effects.

Pure White Cell Aplasia and Immune Thrombocytopenia after Thymoma Resection: A Case Report and Review of the Literature.

We report a case of pure white cell aplasia (PWCA) postthymoma resection in a 74-year-old male presenting with a 2-week history of fevers, night sweats, and severe febrile neutropenia. His pure white cell aplasia was treated with intravenous immunoglobulin (IVIg), granulocyte colony-stimulating factor (G-CSF), prednisone, and cyclosporine with a mixed response. He also developed immune thrombocytopenia, which responded well to a short course of eltrombopag. With continued cyclosporine treatment, his platelet counts were stable after stopping eltrombopag. The patient's cyclosporine treatment was complicated by renal failure, resulting in cessation of cyclosporine. His PWCA and immune thrombocytopenia significantly worsened after stopping cyclosporine, and unfortunately, he died from multiorgan failure and sepsis.

A Randomized Clinical Trial of Perfusion Modalities in Pediatric Congenital Heart Surgery Patients.

BACKGROUND: The objective of this randomized clinical trial was to investigate the effects of perfusion modalities on cerebral hemodynamics, vital organ injury, quantified by the Pediatric Logistic Organ Dysfunction-2 (PELOD-2) Score, and clinical outcomes in risk-stratified congenital cardiac surgery patients. METHODS: This randomized clinical trial included 159 consecutive congenital cardiac surgery patients in whom pulsatile (n = 83) or nonpulsatile (n = 76) perfusion was used. Cerebral hemodynamics were assessed using transcranial Doppler ultrasound. Multiple organ injury was quantified using the PELOD-2 score at 24, 48, and 72 hours. Clinical outcomes, including intubation time, intensive care unit length of stay (LOS), hospital LOS, and mortality, were also evaluated. RESULTS: The Pulsatility Index at the middle cerebral artery and in the arterial line during aortic cross-clamping was consistently better maintained in the pulsatile group. Demographics and cardiopulmonary bypass characteristics were similar between the 2 groups. While risk stratification with The Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery (STAT) Mortality Categories was similar between the groups, Mortality Categories 1 to 3 demonstrated more patients than Mortality Categories 4 and 5. There were no differences in clinical outcomes between the groups. The PELOD-2 scores showed a progressive improvement from 24 hours to 72 hours, but the results were not statistically different between the groups. CONCLUSIONS: The Pulsatillity Index for the pulsatile group demonstrated a more physiologic pattern compared with the nonpulsatile group. While pulsatile perfusion did not increase plasma-free hemoglobin levels or microemboli delivery, it also did not demonstrate any improvements in clinical outcomes or PELOD-2 scores, suggesting that while pulsatile perfusion is a safe method, it not a "magic bullet" for congenital cardiac operations.

The histone deacetylase inhibitor Romidepsin induces as a cascade of differential gene expression and altered histone H3K9 marks in myeloid leukaemia cells.

Myelodysplastic syndromes (MDS) are a heterogeneous, clonal haematopoietic disorder, with ~1/3 of patients progressing to acute myeloid leukaemia (AML). Many elderly MDS patients do not tolerate intensive therapeutic regimens, and therefore have an unmet need for better tolerated therapies. Epigenetics is important in the pathogenesis of MDS/AML with DNA methylation, and histone acetylation the most widely studied modifications. Epigenetic therapeutic agents have targeted the reversible nature of these modifications with some clinical success. The aim of this study was to characterise the molecular consequences of treatment of MDS and AML cells with the histone deacetylase inhibitor (HDACi) Romidepsin. Romidepsin as a single agent induced cell death with an increasing dose and time profile associated with increased acetylation of histone H3 lysine 9 (H3K9) and decreased HDAC activity. Gene expression profiling, qPCR, network and pathway analysis recognised that oxidation-reduction was involved in response to Romidepsin. ROS was implicated as being involved post-treatment with the involvement of TSPO and MPO. Genomic analysis uncoupled the differences in protein-DNA interactions and gene regulation. The spatial and temporal transcriptional differences associated with acetylated, mono- and tri-methylated H3K9, representative of two activation and a repression mark respectively, were identified. Bioinformatic analysis uncovered positional enrichment and transcriptional differences between these marks; a degree of overlap with increased/decreased gene expression that correlates to increased/decreased histone modification. Overall, this study has unveiled a number of underlying mechanisms of the HDACi Romidepsin that could identify potential drug combinations for use in the clinic.

Hollow Microspherical and Microtubular [3 + 3] Carbazole-Based Covalent Organic Frameworks and Their Gas and Energy Storage Applications.

Covalent organic frameworks (COFs) are a family of crystalline porous networks having applications in various fields, including gas and energy storage. Despite respectable progress in the synthesis of such crystalline materials, examples of the use of template-free methods to construct COFs having hollow nano- and microstructures are rare. Furthermore, all reported methods for synthesizing these hollow structural COFs have involved [4 + 2] and [3 + 2] condensations. Herein, we report the synthesis of hollow microspherical and microtubular carbazole-based COFs through template-free, one-pot, [3 + 3] condensations of the novel triamine 9-(4-aminophenyl)-carbazole-3,6-diamine (Car-3NH2) and triformyl linkers with various degrees of planarity. Depending upon the monomer's planarity, a unique morphological variety was observed. A time-dependent study revealed that each COF formed through an individual mechanism depended on the degree of planarity of the triformyl linker; it also confirmed that the hollow structures of these COFs formed through inside-out Ostwald ripening. Our COFs exhibited high Brunauer-Emmett-Teller surface areas (up to ca. 1400 m2 g-1), excellent crystallinity, and high thermal stability. Moreover, the CO2 uptake capacities of these COFs were excellent: up to 61 and 123 mg g-1 at 298 and 273 K, respectively. The high surface areas facilitated greater numbers of strong interactions with CO2 molecules, leading to high CO2 uptake capacities. Moreover, the prepared COFs exhibited redox activity because of their redox-active triphenylamine and pyridine groups, which can be utilized in electrochemical energy storages. Accordingly, such hollow COFs having high surface areas appear to be useful materials for industrial and biological applications.

Decitabine-Vorinostat combination treatment in acute myeloid leukemia activates pathways with potential for novel triple therapy.

Despite advancements in cancer therapeutics, acute myeloid leukemia patients over 60 years old have a 5-year survival rate of less than 8%. In an attempt to improve this, epigenetic modifying agents have been combined as therapies in clinical studies. In particular combinations with Decitabine and Vorinostat have had varying degrees of efficacy. This study therefore aimed to understand the underlying molecular mechanisms of these agents to identify potential rational epi-sensitized combinations. Combined Decitabine-Vorinostat treatment synergistically decreased cell proliferation, induced apoptosis, enhanced acetylation of histones and further decreased DNMT1 protein with HL-60 cells showing a greater sensitivity to the combined treatment than OCI-AML3. Combination therapy led to reprogramming of unique target genes including AXL, a receptor tyrosine kinase associated with cell survival and a poor prognosis in AML, which was significantly upregulated following treatment. Therefore targeting AXL following epi-sensitization with Decitabine and Vorinostat may be a suitable triple combination. To test this, cells were treated with a novel triple combination therapy including BGB324, an AXL specific inhibitor. Triple combination increased the sensitivity of OCI-AML3 cells to Decitabine and Vorinostat as shown through viability assays and significantly extended the survival of mice transplanted with pretreated OCI-AML3 cells, while bioluminescence imaging showed the decrease in disease burden following triple combination treatment. Further investigation is required to optimize this triple combination, however, these results suggest that AXL is a potential marker of response to Decitabine-Vorinostat combination treatment and offers a new avenue of epigenetic combination therapies for acute myeloid leukemia.

Cytoreductive surgery and hyperthermic intraperitoneal chemoperfusion: The University of Arizona early experience.

AIM: To evaluate the safety and effectiveness of our new cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemoperfusion (HIPEC) program. METHODS: Retrospective review of patients with gastrointestinal malignancies who were suitable candidates for CRS and HIPEC between 12/1/2009 and 10/1/2010. All clinicopathologic data were reviewed with a special focus on the surgical outcome and the postoperative morbidity and mortality. RESULTS: Fourteen patients were identified. Median age was 64 years; seven were female. The primary tumors were: colonic (29%), appendiceal (36%), peritoneal mesothelioma (14%), gastric (7%), adenocarcinoma of unknown primary (7%), and gastrointestinal stromal tumor (7%). Eleven patients (79%) received CRS/HIPEC, three for palliation. Three patients that did not undergo CRS/HIPEC had an average peritoneal cancer index (PCI) of 25. The eight patients that underwent curative CRS/HIPEC had an average PCI of 10 and a completeness of cytoreduction score of 0 (87.5%) or 1 (12.5%). Postoperative morbidity was 36%; the worst adverse event was Grade 3 ileus. Mortality rate was 0%. CONCLUSION: CRS with HIPEC is safe and feasible at tertiary institutions with fledgling programs. PCI is an accurate predictor of surgical outcomes.

Plasma lipid metabolites are associated with gestational age but not bronchopulmonary dysplasia.

AIM: To test the hypothesis that plasma lipid metabolite levels in premature infants are associated with the development of bronchopulmonary dysplasia (BPD). The studies also tested a secondary hypothesis that plasma lipid metabolite levels were correlated with gestational age. METHODS: Infants born <32 weeks' gestation were enrolled during the first 72 h of life. Plasma samples were obtained and lipid levels were measured by LC-MS/MS. Clinical data were collected to determine infant outcomes and BPD diagnosis. RESULTS: Following adjustment for confounders, lipid levels were not associated with BPD; however, levels of specific lipid metabolites were correlated with gestational age. CONCLUSION: Immature lipid metabolism pathways in premature infants may contribute to the pathogenesis of BPD and other diseases.

Computer-enhanced visual learning method: a paradigm to teach and document surgical skills.

INNOVATION: Changes in health care are stimulating residency training programs to develop new methods for teaching surgical skills. We developed Computer-Enhanced Visual Learning (CEVL) as an innovative Internet-based learning and assessment tool. The CEVL method uses the educational procedures of deliberate practice and performance to teach and learn surgery in a stylized manner. AIM OF INNOVATION: CEVL is a learning and assessment tool that can provide students and educators with quantitative feedback on learning a specific surgical procedure. Methods involved examine quantitative data of improvement in surgical skills. Herein, we qualitatively describe the method and show how program directors (PDs) may implement this technique in their residencies. RESULTS: CEVL allows an operation to be broken down into teachable components. The process relies on feedback and remediation to improve performance, with a focus on learning that is applicable to the next case being performed. CEVL has been shown to be effective for teaching pediatric orchiopexy and is being adapted to additional adult and pediatric procedures and to office examination skills. The CEVL method is available to other residency training programs.

Herpes simplex virus-thymidine kinase-based suicide gene therapy as a "molecular switch off" for nerve growth factor production in vitro.

Tissue-engineered constructs offer a new hope to patients suffering from functional impairment after nerve injury. An effort has been made to focus on delivery, regulation, and "molecular shutoff" of nerve growth factor (NGF) in tissue-engineered constructs. We have previously demonstrated that human embryonic kidney (HEK-293) cells can be genetically modified to secrete NGF at varying time points upon up regulation with Ponasterone A (PonA) both in vitro and in vivo. In the present study, HEK-293 cells that stably and inducibly produce NGF were further stably transfected with herpes simplex virus-thymidine kinase gene as a suicide gene (hNGF-EcR-293-TK) in order to shut off the NGF secretion and kill the cells upon treatment with ganciclovir (GCV). These cells following induction with PonA secreted NGF levels of 6659.2 +/- 489.4 pg/mL at day 10 postbooster dose at day 5, which was significantly higher than the control noninduced cells. The NGF secreted by these cells was bioactive as determined by a rat adrenal pheochromocytoma (PC-12) cell bioassay. Treatment of these cells with GCV significantly reduced the NGF levels to 645.3 +/- 16.2 pg/mL at day 10 and live cell numbers dropped to 7.95 x 10(3) +/- 278 compared to 2.73 x 10(5) +/- 6.1 x 10(4). GCV-treated cell media when transferred to the PC-12 cell bioassay demonstrated less than 10% cells differentiating into neurite-like extensions. We conclude that hNGF-EcR-293-TK cells can inducibly secrete bioactive NGF when treated with the inducing agent and can also be killed upon treatment with GCV. This double-gene transfection for gene expression and molecular shutoff mechanism will be a useful tool in tissue-engineered nerve constructs.

The specificity of amylin for the diagnosis of pancreatic adenocarcinoma.

BACKGROUND: Diabetes mellitus or impaired glucose tolerance occurs in up to 80% of patients with pancreatic cancer at the time of cancer diagnosis. It has been reported that plasma amylin (islet amyloid polypeptide [IAPP]) levels are elevated in all patients with pancreatic cancer who are diabetic, and even moderately elevated in pancreatic cancer patients with normal glucose tolerance. AIM: To determine the specificity of elevated amylin levels for pancreatic cancer. METHODS: Plasma amylin levels were determined in 168 patients with one or more of the following medical conditions: benign and malignant biliary obstruction, pancreatic cancer, chronic pancreatitis, acute pancreatitis, other gastrointestinal (GI) malignancies, and newly diagnosed type II diabetes. RESULTS: Elevated levels of plasma amylin were detected in several disorders other than pancreatic cancer--particularly chronic pancreatitis, other GI malignancies, and biliary obstruction from benign causes. No statistical differences in amylin levels were detected for any of the tested medical conditions when compared to pancreatic adenocarcinoma. CONCLUSION: These results suggest that elevated plasma amylin is not specific for pancreatic cancer, thereby limiting its role as a tumor marker. Further studies are needed to determine whether amylin, if used in conjunction with other biological markers, could be useful for the diagnosis of pancreatic cancer.