Citations

Hydrogen sulfide (H2S) is produced endogenously by l-cysteine metabolism. H2S modulates several ion channels with an unclear mechanism of action. A possible mechanism is through reduction-oxidation reactions attributable to the redox potential of the sulfur moiety. The aims of this study were to determine the effects of the H2S donor NaHS on NaV1.5, a voltage-dependent sodium channel expressed in the gastrointestinal tract in human jejunum smooth muscle cells and interstitial cells of Cajal, and to elucidate whether H2S acts on NaV1.5 by redox reactions. Whole cell Na+ currents were recorded in freshly dissociated human jejunum circular myocytes and NaV1.5-transfected human embryonic kidney-293 cells. RT-PCR amplified mRNA for H2S enzymes cystathionine β-synthase and cystathionine γ-lyase from the human jejunum. NaHS increased native Na+ peak currents and shifted the half-point ( V1/2) of steady-state activation and inactivation by +21 ± 2 mV and +15 ± 3 mV, respectively. Similar effects were seen on the heterologously expressed NaV1.5 α subunit with EC50s in the 10−4 to 10−3 M range. The reducing agent dithiothreitol (DTT) mimicked in part the effects of NaHS by increasing peak current and positively shifting steady-state activation. DTT together with NaHS had an additive effect on steady-state activation but not on peak current, suggesting that the latter may be altered via reduction. Pretreatment with the Hg2+-conjugated oxidizer thimerosal or the alkylating agent N-ethylmaleimide inhibited or decreased NaHS induction of NaV1.5 peak current. These studies show that H2S activates the gastrointestinal Na+ channel, and the mechanism of action of H2S is partially redox independent.

AbstractCCN1, also known as CYR61, is a survival and proangiogenic factor overexpressed in about 30% of invasive breast carcinomas, and particularly in triple-negative breast carcinomas (TNBC). CCN1 expression in breast cancer promotes tumorigenicity, metastasis, antihormone, and chemoresistance. TNBCs often develop bone metastasis, thus the vast majority of patients receive bisphosphonate treatment as a companion to chemotherapy. Zoledronic acid (ZOL), a bisphosphonate currently in use, inhibits bone resorption, prevents development of new osteolytic lesions induced by tumor metastasis, and has a direct antitumor activity in breast cancer cells and tumors. We have shown that ZOL inhibits anchorage independent growth as well as branching and morphogenesis in CCN1 overexpressing cells. However, the mechanism is not yet well understood. In this study, we investigate the effect of ZOL in breast cancer cells with high and undetectable CCN1 expression levels. We show that CCN1-expressing cells are more sensitive to ZOL, that ZOL induces downregulation of the CCN1 promoter activity and CCN1 protein expression in a dose-dependent manner, and that ZOL is associated with a decrease in phosphorylated Akt and translocation of FOXO3a, a negative regulator of CCN1 expression, to the nucleus. Deletion of the FOXO3a binding site in the CCN1 promoter prevents ZOL inhibition of the CCN1 promoter activity showing that FOXO3a transcriptional activation is necessary for ZOL to induce CCN1 inhibition. This study provides evidence that ZOL targets the proangiogenic factor (CCN1) through FOXO3a and reveals a new mechanism of ZOL action in breast cancer cells. Mol Cancer Ther; 10(5); 732–41. ©2011 AACR.

AbstractIFNα has been used to treat malignant and viral disorders for more than 25 years. Its efficacy is likely the consequence of its broad range of biologic activities, including direct effects on malignant cells, enhancement of anti-tumor immune responses, induction of proapoptotic genes, inhibition of angiogenesis, and promotion of the cycling of dormant malignant stem cells. Because of the recent development of “targeted” therapies, the use of IFN has been dramatically reduced over the last decade. The increasing awareness of the multistep pathogenesis of many malignancies has suggested, however, that such an approach using target-specific agents is not universally effective. These observations have resulted in a number of recent clinical trials utilizing IFNα in patients with chronic myeloid leukemia (CML), systemic mast cell disease, hypereosinophilic syndrome and the Philadelphia chromosome-negative myeloproliferative neoplasms (MPN) with promising outcomes. These reports provide evidence that IFNα, alone or in combination with other agents, can induce surprisingly robust molecular response rates and possibly improve survival. Although IFNα at present remains an experimental form of therapy for patients with myeloid malignancies, these promising results suggest that it may become again an important component of the therapeutic arsenal for this group of hematologic malignancies.

Abstract Purpose: Dendritic cells (DC) may be the most effective way of delivering oncolytic viruses to patients. Reovirus, a naturally occurring oncolytic virus, is currently undergoing early clinical trials; however, intravenous delivery of the virus is hampered by pre-existing antiviral immunity. Systemic delivery via cell carriage is a novel approach currently under investigation and initial studies have indicated its feasibility by using a variety of cell types and viruses. This study addressed the efficacy of human DC to transport virus in the presence of human neutralizing serum. Experimental Design: Following reovirus-loading, DC or T cells were cocultured with melanoma cells with or without neutralizing serum; the melanoma cells were then analyzed for cell death. Following reovirus loading, cells were examined by electron microscopy to identify mechanisms of delivery. The phagocytic function of reovirus-loaded DC was investigated by using labeled tumor cells and the ability of reovirus-loaded DC to prime T cells was also investigated. Results: In the presence of human neutralizing serum DC, but not T cells, were able to deliver reovirus for melanoma cell killing in vitro. Electron microscopy suggested that DC protected the virus by internalization, whereas with T cells it remained bound to the surface and hence accessible to neutralizing antibodies. Furthermore, DC loaded with reovirus were fully functional with regard to phagocytosis and priming of specific antitumor immune responses. Conclusions: The delivery of reovirus via DC could be a promising new approach offering the possibility of combining systemic viral therapy for metastatic disease with induction of an antitumor immune response. Clin Cancer Res; 17(9); 2767–76. ©2011 AACR.

Extraosseous Ewing's sarcoma (EES) involving the central nervous system is rare, but can be diagnosed and distinguished from other primitive neuroectodermal tumors (PNET) by identification of the chromosomal translocation (11;22)(q24;q12). We report EES arising from the spinal intradural extramedullary space, based on imaging, histopathological, and molecular data in two men, ages 50 and 60 years old and a review of the literature using PubMed (1970–2009). Reverse transcriptase polymerase chain reaction (RT-PCR) identified the fusion product FL1-EWS. Multimodal therapy, including radiation and alternating chemotherapy including vincristine, cyclophosphamide, doxorubicin and ifosfamide and etoposide led to local tumor control and an initial, favorable therapeutic response. No systemic involvement was seen from the time of diagnosis to the time of last follow-up (26 months) or death (4 years). This report confirms that EES is not confined to the earliest decades of life, and like its rare occurrence as an extra-axial meningeal based mass intracranially, can occasionally present as an intradural mass in the spinal canal without evidence of systemic tumor. Gross total resection followed by multimodal therapy may provide for extended progression free and overall survival.

Background— Bystander cardiopulmonary resuscitation (CPR) improves survival from out-of-hospital cardiac arrest (OHCA) but often is not performed. We hypothesized that subjects viewing very short Hands-Only CPR videos will (1) be more likely to attempt CPR in a simulated OHCA scenario and (2) demonstrate better CPR skills than untrained individuals. Methods and Results— This study is a prospective trial of 336 adults without recent CPR training randomized into 4 groups: (1) control (no training) (n=51); (2) 60-second video training (n=95); (3) 5-minute video training (n=99); and (4) 8-minute video training, including manikin practice (n=91). All subjects were tested for their ability to perform CPR during an adult OHCA scenario using a CPR-sensing manikin and Laerdal PC SkillReporting software. One half of the trained subjects were randomly assigned to testing immediately and the other half after a 2-month delay. Twelve (23.5%) controls did not even attempt CPR, which was true of only 2 subjects (0.7%; P =0.01) from any of the experimental groups. All experimental groups had significantly higher average compression rates (closer to the recommended 100/min) than the control group ( P <0.001), and all experimental groups had significantly greater average compression depth (>38 mm) than the control group ( P <0.0001). Conclusions— Laypersons exposed to very short Hands-Only CPR videos are more likely to attempt CPR and show superior CPR skills than untrained laypersons. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT01191736.

Lipids are important substrates for oxidation at rest and during exercise. Aerobic exercise mediates a delayed onset decrease in total and VLDL-triglyceride (TG) plasma concentration. However, the acute effects of exercise on VLDL-TG oxidation and turnover remain unclear. Here, we studied the acute effects of 90 min of moderate-intensity exercise in healthy women and men. VLDL-TG kinetics were assessed using a primed constant infusion of ex vivo labeled [1-14C]triolein VLDL-TG. Fractional VLDL-TG-derived fatty acid oxidation was measured from14CO2specific activity in expired air. VLDL-TG concentration was unaltered during exercise and early recovery, whereas non-VLDL-TG concentration decreased significantly.VLDL-TG secretion rate decreased significantly during exercise and remained suppressed during recovery. Total VLDL-TG oxidation rate was unaffected by exercise. However, the contribution of VLDL-TG oxidation to total energy expenditure fell from 14 ± 9% at rest to 3 ± 4% during exercise. We conclude that VLDL-TG fatty acids are quantitatively important oxidative substrates under basal postabsorptive conditions but remain unaffected during 90-min moderate-intensity exercise and, thus, become relatively less important during exercise. Lower VLDL secretion rate during exercise may contribute to the decrease in TG concentrations during and after exercise.

Abstract POEMS is an uncommon syndromic disorder characterized by polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes. There are few descriptions of the bone marrow pathology of POEMS; therefore, peripheral blood smears and bone marrow aspirates and biopsies from 87 patients (143 total, 67 pretreatment, 76 posttreatment cases) with POEMS were studied. Plasma cell clonality was analyzed by flow cytometry, immunohistochemistry, and/or in situ hybridization. Monotypic plasma cells were detected in 44 pretreatment cases (66%); the majority of plasma cells expressed λ light chain (91%). The monotypic plasma cells typically were present in a background of increased polytypic plasma cells. Lymphoid aggregates were found in 33 (49%) pretreatment cases and in most cases were rimmed by plasma cells (97%). Megakaryocyte hyperplasia (36 cases) and clusters (62 cases) were frequent; however, none of the 43 cases tested had the JAK2V617F mutation. In summary, we have identified a novel constellation of features that should strongly suggest POEMS syndrome as part of the differential diagnosis. The constellation of λ-restricted monoclonal gammopathy, plasma cell rimming around lymphoid aggregates, and megakaryocytic hyperplasia in a bone marrow is highly suggestive of this diagnosis, especially in the context of a peripheral neuropathy.

OBJECTIVE The metabolic syndrome (MetS) is defined as concomitant disorders of lipid and glucose metabolism, central obesity, and high blood pressure, with an increased risk of type 2 diabetes and cardiovascular disease. This study tests whether common genetic variants with pleiotropic effects account for some of the correlated architecture among five metabolic phenotypes that define MetS. RESEARCH DESIGN AND METHODS Seven studies of the STAMPEED consortium, comprising 22,161 participants of European ancestry, underwent genome-wide association analyses of metabolic traits using a panel of ∼2.5 million imputed single nucleotide polymorphisms (SNPs). Phenotypes were defined by the National Cholesterol Education Program (NCEP) criteria for MetS in pairwise combinations. Individuals exceeding the NCEP thresholds for both traits of a pair were considered affected. RESULTS Twenty-nine common variants were associated with MetS or a pair of traits. Variants in the genes LPL, CETP, APOA5 (and its cluster), GCKR (and its cluster), LIPC, TRIB1, LOC100128354/MTNR1B, ABCB11, and LOC100129150 were further tested for their association with individual qualitative and quantitative traits. None of the 16 top SNPs (one per gene) associated simultaneously with more than two individual traits. Of them 11 variants showed nominal associations with MetS per se. The effects of 16 top SNPs on the quantitative traits were relatively small, together explaining from ∼9% of the variance in triglycerides, 5.8% of high-density lipoprotein cholesterol, 3.6% of fasting glucose, and 1.4% of systolic blood pressure. CONCLUSIONS Qualitative and quantitative pleiotropic tests on pairs of traits indicate that a small portion of the covariation in these traits can be explained by the reported common genetic variants.