Estrogen receptor β exhibited anti-tumor effects on osteosarcoma cells by regulating integrin, IAP, NF-kB/BCL-2 and PI3K/Akt signal pathway

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Minfei Yang

2017-11-01

Full Text Available This study aimed to investigate the effects of Estrogen receptor β (ERβ on osteosarcoma cells, and explore the regulatory mechanisms involved in this process. Osteosarcoma U2-OS cells consisted four groups, and treated by E2, E2 + LY294002 (ERβ agonists, E2 + ERβ siRNA, E2 + ERβ siRNA + LY294002, respectively. Cell counting kit 8 (CCK-8 assay was performed to detect the cell viability of U2-OS cells in each group. The effects of ERβ on the migration and invasion ability of U2-OS cells were examined by wound healing assay and transwell cell culture chamber, respectively. The expression of Inhibitor of apoptosis protein (IAP and integrin α5 in U2-OS cells of each group was detected by quantitative RT-PCR, and the expression of phosphorylated p65 (p-p65, p-AKT and Bcl-2 was detected by western blotting. The cell viability, migration and invasion ability of U2-OS cells were significantly increased by ERβ siRNA, but inhibited by ERβ agonists LY294002 (p < 0.05. ERβ siRNA significantly downregulated Integrin α5 and unregulated IAP in U2-OS cells (p < 0.05. The expression of p-p65, p-AKT and Bcl-2 was significantly reduced by LY294002, but increased by ERβ siRNA (p < 0.05. In conclusion, ERβ exhibited obvious anti-tumor effects on osteosarcoma cells by regulating integrin, IAP, NF-kBBCL-2 and PI3K/Akt signal pathway. Keywords: Estrogen receptor β, Osteosarcoma, Anti-tumor, Regulatory mechanism

Engineering a morphogenetically active hydrogel for bioprinting of bioartificial tissue derived from human osteoblast-like SaOS-2 cells.

Science.gov (United States)

Neufurth, Meik; Wang, Xiaohong; Schröder, Heinz C; Feng, Qingling; Diehl-Seifert, Bärbel; Ziebart, Thomas; Steffen, Renate; Wang, Shunfeng; Müller, Werner E G

2014-10-01

Sodium alginate hydrogel, stabilized with gelatin, is a suitable, biologically inert matrix that can be used for encapsulating and 3D bioprinting of bone-related SaOS-2 cells. However, the cells, embedded in this matrix, remain in a non-proliferating state. Here we show that addition of an overlay onto the bioprinted alginate/gelatine/SaOS-2 cell scaffold, consisting of agarose and the calcium salt of polyphosphate [polyP·Ca(2+)-complex], resulted in a marked increase in cell proliferation. In the presence of 100 μm polyP·Ca(2+)-complex, the cells proliferate with a generation time of approximately 47-55 h. In addition, the hardness of the alginate/gelatin hydrogel substantially increases in the presence of the polymer. The reduced Young's modulus for the alginate/gelatin hydrogel is approximately 13-14 kPa, and this value drops to approximately 0.5 kPa after incubation of the cell containing scaffolds for 5 d. In the presence of 100 μm polyP·Ca(2+)-complex, the reduced Young's modulus increases to about 22 kPa. The hardness of the polyP·Ca(2+)-complex containing hydrogel remains essentially constant if cells are absent in the matrix, but it drops to 3.2 kPa after a 5 d incubation period in the presence of SaOS-2 cells, indicating that polyP·Ca(2+)-complex becomes metabolized, degraded, by the cells. The alginate/gelatine-agarose system with polyP·Ca(2+)-complex cause a significant increase in the mineralization of the cells. SEM analyses revealed that the morphology of the mineral nodules formed on the surface of the cells embedded in the alginate/gelatin hydrogel do not significantly differ from the nodules on cells growing in monolayer cultures. The newly developed technique, using cells encapsulated into an alginate/gelatin hydrogel and a secondary layer containing the morphogenetically active, growth promoting polymer polyP·Ca(2+)-complex opens new possibilities for the application of 3D bioprinting in bone tissue engineering. Copyright �

Synthesis and X-ray crystal structure of (OsO(3)F(2))(2)2XeOF(4) and the Raman spectra of (OsO(3)F(2))(infinity), (OsO(3)F(2))(2), and (OsO(3)F(2))(2)2XeOF(4).

Science.gov (United States)

Hughes, Michael J; Mercier, Hélène P A; Schrobilgen, Gary J

2009-05-18

The adduct, (OsO(3)F(2))(2)2XeOF(4), was synthesized by dissolution of the infinite chain polymer, (OsO(3)F(2))(infinity), in XeOF(4) solvent at room temperature followed by removal of excess XeOF(4) under dynamic vacuum at 0 degrees C. Continued pumping at 0 degrees C resulted in removal of associated XeOF(4), yielding (OsO(3)F(2))(2), a new low-temperature phase of OsO(3)F(2). Upon standing at 25 degrees C for 1(1)/(2) h, (OsO(3)F(2))(2) underwent a phase transition to the known monoclinic phase, (OsO(3)F(2))(infinity). The title compounds, (OsO(3)F(2))(infinity), (OsO(3)F(2))(2), and (OsO(3)F(2))(2)2XeOF(4) have been characterized by low-temperature (-150 degrees C) Raman spectroscopy. Crystallization of (OsO(3)F(2))(2)2XeOF(4) from XeOF(4) solution at 0 degrees C yielded crystals suitable for X-ray structure determination. The structural unit contains the (OsO(3)F(2))(2) dimer in which the OsO(3)F(3) units are joined by two Os---F---Os bridges having fluorine bridge atoms that are equidistant from the osmium centers (2.117(5) and 2.107(4) A). The dimer coordinates to two XeOF(4) molecules through Os-F...Xe bridges in which the Xe...F distances (2.757(5) A) are significantly less than the sum of the Xe and F van der Waals radii (3.63 A). The (OsO(3)F(2))(2) dimer has C(i) symmetry in which each pseudo-octahedral OsO(3)F(3) unit has a facial arrangement of oxygen ligands with XeOF(4) molecules that are only slightly distorted from their gas-phase C(4v) symmetry. Quantum-chemical calculations using SVWN and B3LYP methods were employed to calculate the gas-phase geometries, natural bond orbital analyses, and vibrational frequencies of (OsO(3)F(2))(2), (OsO(3)F(2))(2)2XeOF(4), XeOF(4), OsO(2)F(4), and (mu-FOsO(3)F(2))(2)OsO(3)F(-) to aid in the assignment of the experimental vibrational frequencies of (OsO(3)F(2))(2), (OsO(3)F(2))(2)2XeOF(4), and (OsO(3)F(2))(infinity). The vibrational modes of the low-temperature polymeric phase, (OsO(3)F(2))(infinity), have been

Effects of polydeoxyribonucleotides (PDRN) on wound healing: Electric cell-substrate impedance sensing (ECIS)

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Koo, Youngmi; Yun, Yeoheung, E-mail: yyun@ncat.edu

2016-12-01

Polydeoxyribonucleotides (PDRN) have been explored as an effective treatment for tissue repair in peripheral artery occlusive disease, diabetic foot ulcers, and eye lotion. We report on the effect of polydeoxyribonucleotides (PDRN) on wound healing by using the electric cell-substrate impedance sensing (ECIS) system and viability testing. Human osteoblasts (U2OS) and primary human dermal fibroblasts (HDF) were used to study the effect of PDRN on migration and proliferation. ECIS allowed the creation of a wound by applying high current, and then monitoring the healing process by measuring impedance in real time. The traditional culture-insert gap-closure migration assay was performed and compared with the ECIS wound assay. PDRN-treated U2OS and HDF cells affected cell motilities to wounding site. Viability test results show that HDF and U2OS proliferation depended on PDRN concentration. Based on the results, a PDRN compound can be useful in wound healing associated with bone and skin. - Highlights: • Wound-healing study by the electric cell-substrate impedance sensing (ECIS). • Effect of polydeoxyribonucleotides (PDRN) on migration and proliferation of U2OS and HDF. • Effect of PDRN concentration on viability of U2OS and HDF.

Effects of polydeoxyribonucleotides (PDRN) on wound healing: Electric cell-substrate impedance sensing (ECIS)

International Nuclear Information System (INIS)

Koo, Youngmi; Yun, Yeoheung

2016-01-01

Polydeoxyribonucleotides (PDRN) have been explored as an effective treatment for tissue repair in peripheral artery occlusive disease, diabetic foot ulcers, and eye lotion. We report on the effect of polydeoxyribonucleotides (PDRN) on wound healing by using the electric cell-substrate impedance sensing (ECIS) system and viability testing. Human osteoblasts (U2OS) and primary human dermal fibroblasts (HDF) were used to study the effect of PDRN on migration and proliferation. ECIS allowed the creation of a wound by applying high current, and then monitoring the healing process by measuring impedance in real time. The traditional culture-insert gap-closure migration assay was performed and compared with the ECIS wound assay. PDRN-treated U2OS and HDF cells affected cell motilities to wounding site. Viability test results show that HDF and U2OS proliferation depended on PDRN concentration. Based on the results, a PDRN compound can be useful in wound healing associated with bone and skin. - Highlights: • Wound-healing study by the electric cell-substrate impedance sensing (ECIS). • Effect of polydeoxyribonucleotides (PDRN) on migration and proliferation of U2OS and HDF. • Effect of PDRN concentration on viability of U2OS and HDF.

Sublethal dose of irradiation enhances invasion of malignant glioma cells through p53-MMP 2 pathway in U87MG mouse brain tumor model

International Nuclear Information System (INIS)

Pei, Jian; Park, In-Ho; Ryu, Hyang-Hwa; Li, Song-Yuan; Li, Chun-Hao; Lim, Sa-Hoe; Wen, Min; Jang, Woo-Youl; Jung, Shin

2015-01-01

Glioblastoma is a highly lethal neoplasm that frequently recurs locally after radiotherapy, and most of these recurrences originate from near the irradiated target field. In the present study, we identified the effects of radiation on glioma invasion and p53, TIMP-2, and MMP-2 expression through in vitro and in vivo experiments. The U87MG (wt p53) and U251 (mt p53) human malignant glioma cell lines were prepared, and the U2OS (wt 53) and Saos2 (del p53) osteosarcoma cell lines were used as p53 positive and negative controls. The four cell lines and p53 knock-downed U87MG cells received radiation (2–6 Gy) and were analyzed for expression of p53 and TIMP-2 by Western blot, and MMP-2 activity was detected by zymography. In addition, the effects of irradiation on directional invasion of malignant glioma were evaluated by implanting nude mice with bioluminescent u87-Fluc in vivo followed by MMP-2, p53, and TIMP-2 immunohisto-chemistry and in situ zymography. MMP-2 activity and p53 expression increased in proportional to the radiation dose in cell lines with wt p53, but not in the cell lines with del or mt p53. TIMP-2 expression did not increase in U87MG cells. MMP-2 activity decreased in p53 knock-downed U87MG cells but increased in the control group. Furthermore, radiation enhanced MMP-2 activity and increased tumor margin invasiveness in vivo. Tumor cells invaded by radiation overexpressed MMP-2 and p53 and revealed high gelatinolytic activity compared with those of non-radiated tumor cells. Radiation-induced upregulation of p53 modulated MMP-2 activity, and the imbalance between MMP-2 and TIMP-2 may have an important role in glioblastoma invasion by degrading the extracellular matrix. Bioluminescent “U87-Fluc”was useful for observing tumor formation without sacrifice after implanting tumor cells in the mouse brain. These findings suggest that the radiotherapy involved field for malignant glioma needs to be reconsidered, and that future trials should investigate

Mutation in Rice Abscisic Acid2 Results in Cell Death, Enhanced Disease-Resistance, Altered Seed Dormancy and Development

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Yongxiang Liao

2018-03-01

Full Text Available Lesion mimic mutants display spontaneous cell death, and thus are valuable for understanding the molecular mechanism of cell death and disease resistance. Although a lot of such mutants have been characterized in rice, the relationship between lesion formation and abscisic acid (ABA synthesis pathway is not reported. In the present study, we identified a rice mutant, lesion mimic mutant 9150 (lmm9150, exhibiting spontaneous cell death, pre-harvest sprouting, enhanced growth, and resistance to rice bacterial and blast diseases. Cell death in the mutant was accompanied with excessive accumulation of H2O2. Enhanced disease resistance was associated with cell death and upregulation of defense-related genes. Map-based cloning identified a G-to-A point mutation resulting in a D-to-N substitution at the amino acid position 110 of OsABA2 (LOC_Os03g59610 in lmm9150. Knock-out of OsABA2 through CRISPR/Cas9 led to phenotypes similar to those of lmm9150. Consistent with the function of OsABA2 in ABA biosynthesis, ABA level in the lmm9150 mutant was significantly reduced. Moreover, exogenous application of ABA could rescue all the mutant phenotypes of lmm9150. Taken together, our data linked ABA deficiency to cell death and provided insight into the role of ABA in rice disease resistance.

Mutation in Rice Abscisic Acid2 Results in Cell Death, Enhanced Disease-Resistance, Altered Seed Dormancy and Development.

Science.gov (United States)

Liao, Yongxiang; Bai, Que; Xu, Peizhou; Wu, Tingkai; Guo, Daiming; Peng, Yongbin; Zhang, Hongyu; Deng, Xiaoshu; Chen, Xiaoqiong; Luo, Ming; Ali, Asif; Wang, Wenming; Wu, Xianjun

2018-01-01

Lesion mimic mutants display spontaneous cell death, and thus are valuable for understanding the molecular mechanism of cell death and disease resistance. Although a lot of such mutants have been characterized in rice, the relationship between lesion formation and abscisic acid (ABA) synthesis pathway is not reported. In the present study, we identified a rice mutant, lesion mimic mutant 9150 ( lmm9150 ), exhibiting spontaneous cell death, pre-harvest sprouting, enhanced growth, and resistance to rice bacterial and blast diseases. Cell death in the mutant was accompanied with excessive accumulation of H 2 O 2 . Enhanced disease resistance was associated with cell death and upregulation of defense-related genes. Map-based cloning identified a G-to-A point mutation resulting in a D-to-N substitution at the amino acid position 110 of OsABA2 (LOC_Os03g59610) in lmm9150 . Knock-out of OsABA2 through CRISPR/Cas9 led to phenotypes similar to those of lmm9150 . Consistent with the function of OsABA2 in ABA biosynthesis, ABA level in the lmm9150 mutant was significantly reduced. Moreover, exogenous application of ABA could rescue all the mutant phenotypes of lmm9150 . Taken together, our data linked ABA deficiency to cell death and provided insight into the role of ABA in rice disease resistance.

Stem cell survival is severely compromised by the thymidineanalog EdU (5-ethynyl-2'-deoxyuridine), an alternative to BrdU for proliferation assays and stem cell tracing

DEFF Research Database (Denmark)

Andersen, Ditte C; Skovrind, Ida; Christensen, Marlene Louise

2013-01-01

Stem cell therapy has opened up the possibility of treating numerous degenerating diseases. However, we are still merely at the stage of identifying appropriate sources of stem cells and exploring their full differentiation potential. Thus, tracking the stem cells upon in vivo engraftment...... and during in vitro co-culture is very important and is an area of research embracing many pitfalls. 5-Ethynyl-2'-deoxyuridine (EdU), a rather new thymidine analog incorporated into DNA, has recently been suggested to be a novel highly valid alternative to other dyes for labeling of stem cells and subsequent...... tracing of their proliferation and differentiation ability. However, our results herein do not at any stage support this recommendation, since EdU severely reduces the viability of stem cells. Accordingly, we found that transplanted EdU-labeled stem cells hardly survive upon in vivo transplantation...

Ginsenoside Rg3 induces DNA damage in human osteosarcoma cells and reduces MNNG-induced DNA damage and apoptosis in normal human cells.

Science.gov (United States)

Zhang, Yue-Hui; Li, Hai-Dong; Li, Bo; Jiang, Sheng-Dan; Jiang, Lei-Sheng

2014-02-01

Panax ginseng is a Chinese medicinal herb. Ginsenosides are the main bioactive components of P. ginseng, and ginsenoside Rg3 is the primary ginsenoside. Ginsenosides can potently kill various types of cancer cells. The present study was designed to evaluate the potential genotoxicity of ginsenoside Rg3 in human osteosarcoma cells and the protective effect of ginsenoside Rg3 with respect to N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced DNA damage and apoptosis in a normal human cell line (human fibroblasts). Four human osteosarcoma cell lines (MG-63, OS732, U-2OS and HOS cells) and a normal human cell line (human fibroblasts) were employed to investigate the cytotoxicity of ginsenosides Rg3 by MTT assay. Alkaline comet assay and γH2AX focus staining were used to detect the DNA damage in MG-63 and U-2OS cells. The extent of cell apoptosis was determined by flow cytometry and a DNA ladder assay. Our results demonstrated that the cytotoxicity of ginsenoside Rg3 was dose-dependent in the human osteosarcoma cell lines, and MG-63 and U-2OS cells were the most sensitive to ginsenoside Rg3. As expected, compared to the negative control, ginsenoside Rg3 significantly increased DNA damage in a concentration-dependent manner. In agreement with the comet assay data, the percentage of γH2AX-positive MG-63 and U-2OS cells indicated that ginsenoside Rg3 induced DNA double-strand breaks in a concentration-dependent manner. The results also suggest that ginsenoside Rg3 reduces the extent of MNNG-induced DNA damage and apoptosis in human fibroblasts.

Electro-oxidation of borohydride on colloidal Os and Os-alloys (Os-Sn, Os-Mo and Os-V)

Energy Technology Data Exchange (ETDEWEB)

Atwan, M.H.; Northwood, D.O. [Windsor Univ., ON (Canada). Dept. of Mechanical, Automotive and Materials Engineering; Gyenge, E.L. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Chemical and Biological Engineering

2005-10-15

Preliminary experimental studies have demonstrated the possibility of using sodium borohydride (NaBH{sub 4}) oxidation catalysis by osmium (Os) in 2 M sodium hydroxide (NaOH) in the presence of thiourea as an inhibitor to hydrogen (H{sub 2}) evolution. The usefulness of this information for low-temperature direct fuel cells involving the anodic oxidation of fuels such as methanol, ethanol and sodium borohydride was discussed with reference to the challenge of high anode surface overpotential affecting the power output of direct fuel cells. This study examined the cyclic voltammetry features of supported colloidal Os and Os alloys with molybdenum, vanadium and tin, in the presence of NaBH{sub 4}. It also examined the potential for electrocatalysis in direct borohydride fuel cells (DBFC). Colloidal Os and Os alloys were tested for their use as electrocatalysts for oxidation of borohydride. The features of an Os cyclic voltammogram in alkaline media with and without BH{sub 4} were discussed along with the redox mediated oxidation of BH{sub 4}. Cyclic voltammetry and chronopotentiometry tests showed that colloidal Os 20 per cent weight supported on Vulcan XC-72R possessed electrocatalytic activity toward borohydride oxidation while the investigated Os-alloys were catalytically inactive. Chronopotentiometry experiments also showed that the 20 per cent weight Os gave the lowest anodic potential, and is therefore recommended as the anode electrocatalyst in direct borohydride fuel cells. 29 refs., 1 tab., 7 figs.

Long Noncoding RNA PANDA Positively Regulates Proliferation of Osteosarcoma Cells.

Science.gov (United States)

Kotake, Yojiro; Goto, Taiki; Naemura, Madoka; Inoue, Yasutoshi; Okamoto, Haruna; Tahara, Keiichiro

2017-01-01

A long noncoding RNA, p21-associated ncRNA DNA damage-activated (PANDA), associates with nuclear transcription factor Y subunit alpha (NF-YA) and inhibits its binding to promoters of apoptosis-related genes, thereby repressing apoptosis in normal human fibroblasts. Here, we show that PANDA is involved in regulating proliferation in the U2OS human osteosarcoma cell line. U2OS cells were transfected with siRNAs against PANDA 72 h later and they were subjected to reverse transcription-polymerase chain reaction (RT-PCR), quantitative RT-PCR and cell-cycle analysis. PANDA was highly expressed in U2OS cells, and its expression was induced by DNA damage. Silencing PANDA caused arrest at the G 1 phase of the cell cycle, leading to inhibition of cell proliferation. Quantitative RT-PCR showed that silencing PANDA increased mRNA levels of the cyclin-dependent kinase inhibitor p18, which caused G 1 phase arrest. These results suggest that PANDA promotes G 1 -S transition by repressing p18 transcription, and thus promotes U2OS cell proliferation. Copyright© 2017 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

VPA and MEL induce apoptosis by inhibiting the Nrf2-ARE signaling pathway in TMZ-resistant U251 cells.

Science.gov (United States)

Pan, Hao; Wang, Handong; Jia, Yue; Wang, Qiang; Li, Liwen; Wu, Qi; Chen, Longbang

2017-07-01

Chemoresistance is the primary obstacle to effective treatment of glioblastoma, the most lethal brain tumor. Our previous study demonstrated that Nf-E2 related factor 2 (Nrf2), a traditional cytoprotective transcription factor, was overexpressed in gliomas and promoted malignancy. The present study aimed to investigate the expression levels of Nrf2‑antioxidant response element (ARE) signaling pathway genes in temozolomide (TMZ)‑resistant U251 human glioblastoma cells (U251‑TMZ). Additionally, the effect of valproic acid (VPA) and melatonin (MEL) on Nrf2 expression in U251‑TMZ cells and their association with chemoresistance was investigated. The results of the present study indicated that the expression levels of components of the Nrf2‑ARE signaling pathway were increased in U251‑TMZ cells compared with U251 parent cells. Silencing of Nrf2 by transfection with small interfering RNA restored the chemosensitivity of U251‑TMZ cells. The Nrf2 inhibitors VPA and MEL successfully reduced Nrf2 expression and survival in U251‑TMZ cells treated with TMZ, accompanied by increased reactive oxygen species levels and apoptosis. Therefore, VPA and MEL may be potential chemotherapeutic sensitizers for the treatment of chemoresistant glioblastoma.

Molybdenum mineralization at Alpeiner Scharte, Tyrol (Austria): results of in-situ U-Pb zircon and Re-Os molybdenite dating

International Nuclear Information System (INIS)

Langthaler, K.J.; Raith, J.G.; Cornell, D.H.; Stein, H.J.; Melcher, F.

2004-01-01

Vein-type Mo mineralization at Alpeiner Scharte occurs in the Penninic units of the western Tauern Window in the Eastern Alps. Three types of previously undated metagranitoids (central gneisses) are distinguished and preserve intrusive contacts with pre-Alpine metamorphosed supracrustal rocks. The granitic protoliths represent fractionated late to post-orogenic, calc-alkaline, I-type magmas with minor S-type components. The Mo veins are restricted to a biotite and alkali feldspar-rich gneiss variety and occur in E-W trending normally sub-vertical quartz veins with adjacent thin discontinuous garnet- and biotite-rich zones; the latter are interpreted as metamorphosed vein selvages. Prior to this work the age of the intrusive host rocks as well as the age of Mo mineralization were unknown. The pre-Alpine Mo deposit and its host rocks were affected by four Alpine deformation events (D 1 -D 4 ) and Young-Alpine regional metamorphism. The P-T conditions of this metamorphic event were ∼ 550 o C and ∼ 8 kbar and are in agreement with results of previous regional studies. Zircon grains from two orthogneiss samples were dated with the U-Pb method using ion probe techniques. Zircons from the metagranitic host rock of the Mo-veins yielded an emplacement age of 306.8 ± 3.8 Ma (2σ). A second sample from a more leucocratic gneiss lacking Mo-veins gave 305.0 ± 6.6 Ma (2 σ). Re-Os dating of molybdenite from the veins yielded an age of 306.8 ± 3.1 Ma in good agreement with the U-Pb zircon ages. This study confirms one of two alternative hypotheses discussed in the literature. lt supports the idea that vein-type Mo-mineralization in the western Tauern Window is genetically related to Late Carboniferous (Westphalian) granitoids that were emplaced during the late to post-orogenic stage of the Variscan orogeny. They do not constitute an Alpine metamorphic-hydrothermal deposit. This study further confirms the strength of the Re-Os molybdenite chronometer, in that it was

The crosstalk between α-irradiated Beas-2B cells and its bystander U937 cells through MAPK and NF-κB signaling pathways

Energy Technology Data Exchange (ETDEWEB)

Fu, Jiamei; Yuan, Dexiao; Xiao, Linlin; Tu, Wenzhi; Dong, Chen; Liu, Weili; Shao, Chunlin, E-mail: clshao@shmu.edu.cn

2016-01-15

Highlights: • α-irradiated Beas-2B cells induced bystander effects in macrophage U937 cells. • The neighboring macrophages enhanced the damage of α-irradiated Beas-2B cells. • MAPK and NF-κB pathways were activated in U937 cells after cell co-culture. • NF-κB and MAPK pathways participated in the bilateral bystander responses. - Abstract: Although accumulated evidence suggests that α-particle irradiation induced bystander effect may relevant to lung injury and cancer risk assessment, the exact mechanisms are not yet elucidated. In the present study, a cell co-culture system was used to investigate the interaction between α-particle irradiated human bronchial epithelial cells (Beas-2B) and its bystander macrophage U937 cells. It was found that the cell co-culture amplified the detrimental effects of α-irradiation including cell viability decrease and apoptosis promotion on both irradiated cells and bystander cells in a feedback loop which was closely relevant to the activation of MAPK and NF-κB pathways in the bystander U937 cells. When these two pathways in U937 cells were disturbed by special pharmacological inhibitors before cell co-culture, it was found that a NF-κB inhibitor of BAY 11-7082 further enhanced the proliferation inhibition and apoptosis induction in bystander U937 cells, but MAPK inhibitors of SP600125 and SB203580 protected cells from viability loss and apoptosis and U0126 presented more beneficial effect on cell protection. For α-irradiated epithelial cells, the activation of NF-κB and MAPK pathways in U937 cells participated in detrimental cellular responses since the above inhibitors could largely attenuate cell viability loss and apoptosis of irradiated cells. Our results demonstrated that there are bilateral bystander responses between irradiated lung epithelial cells and macrophages through MAPK and NF-κB signaling pathways, which accounts for the enhancement of α-irradiation induced damage.

The crosstalk between α-irradiated Beas-2B cells and its bystander U937 cells through MAPK and NF-κB signaling pathways

International Nuclear Information System (INIS)

Fu, Jiamei; Yuan, Dexiao; Xiao, Linlin; Tu, Wenzhi; Dong, Chen; Liu, Weili; Shao, Chunlin

2016-01-01

Highlights: • α-irradiated Beas-2B cells induced bystander effects in macrophage U937 cells. • The neighboring macrophages enhanced the damage of α-irradiated Beas-2B cells. • MAPK and NF-κB pathways were activated in U937 cells after cell co-culture. • NF-κB and MAPK pathways participated in the bilateral bystander responses. - Abstract: Although accumulated evidence suggests that α-particle irradiation induced bystander effect may relevant to lung injury and cancer risk assessment, the exact mechanisms are not yet elucidated. In the present study, a cell co-culture system was used to investigate the interaction between α-particle irradiated human bronchial epithelial cells (Beas-2B) and its bystander macrophage U937 cells. It was found that the cell co-culture amplified the detrimental effects of α-irradiation including cell viability decrease and apoptosis promotion on both irradiated cells and bystander cells in a feedback loop which was closely relevant to the activation of MAPK and NF-κB pathways in the bystander U937 cells. When these two pathways in U937 cells were disturbed by special pharmacological inhibitors before cell co-culture, it was found that a NF-κB inhibitor of BAY 11-7082 further enhanced the proliferation inhibition and apoptosis induction in bystander U937 cells, but MAPK inhibitors of SP600125 and SB203580 protected cells from viability loss and apoptosis and U0126 presented more beneficial effect on cell protection. For α-irradiated epithelial cells, the activation of NF-κB and MAPK pathways in U937 cells participated in detrimental cellular responses since the above inhibitors could largely attenuate cell viability loss and apoptosis of irradiated cells. Our results demonstrated that there are bilateral bystander responses between irradiated lung epithelial cells and macrophages through MAPK and NF-κB signaling pathways, which accounts for the enhancement of α-irradiation induced damage.

Sulforaphane inhibits invasion via activating ERK1/2 signaling in human glioblastoma U87MG and U373MG cells.

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Chunliu Li

Full Text Available Glioblastoma has highly invasive potential, which might result in poor prognosis and therapeutic failure. Hence, the key we study is to find effective therapies to repress migration and invasion. Sulforaphane (SFN was demonstrated to inhibit cell growth in a variety of tumors. Here, we will further investigate whether SFN inhibits migration and invasion and find the possible mechanisms in human glioblastoma U87MG and U373MG cells.First, the optimal time and dose of SFN for migration and invasion study were determined via cell viability and cell morphological assay. Further, scratch assay and transwell invasion assay were employed to investigate the effect of SFN on migration and invasion. Meanwhile, Western blots were used to detect the molecular linkage among invasion related proteins phosphorylated ERK1/2, matrix metalloproteinase-2 (MMP-2 and CD44v6. Furthermore, Gelatin zymography was performed to detect the inhibition of MMP-2 activation. In addition, ERK1/2 blocker PD98059 (25 µM was integrated to find the link between activated ERK1/2 and invasion, MMP-2 and CD44v6.The results showed that SFN (20 µM remarkably reduced the formation of cell pseudopodia, indicating that SFN might inhibit cell motility. As expected, scratch assay and transwell invasion assay showed that SFN inhibited glioblastoma cell migration and invasion. Western blot and Gelatin zymography showed that SFN phosphorylated ERK1/2 in a sustained way, which contributed to the downregulated MMP-2 expression and activity, and the upregulated CD44v6 expression. These molecular interactions resulted in the inhibition of cell invasion.SFN inhibited migration and invasion processes. Furthermore, SFN inhibited invasion via activating ERK1/2 in a sustained way. The accumulated ERK1/2 activation downregulated MMP-2 expression and decreased its activity and upregulated CD44v6. SFN might be a potential therapeutic agent by activating ERK1/2 signaling against human glioblastoma.

U^{28+}-intensity record applying a H_{2}-gas stripper cell

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Winfried Barth

2015-04-01

Full Text Available To meet the Facility for Antiproton and Ion Research science requirements higher beam intensity has to be achieved in the present GSI-accelerator complex. For this an advanced upgrade program for the UNILAC is ongoing. Stripping is a key technology for all heavy ion accelerators. For this an extensive research and development program was carried out to optimize for high brilliance heavy ion operation. After upgrade of the supersonic N_{2}-gas jet (2007, implementation of high current foil stripping (2011 and preliminary investigation of H_{2}-gas jet operation (2012, recently (2014 a new H_{2}-gas cell using a pulsed gas regime synchronized with arrival of the beam pulse has been developed. An obviously enhanced stripper gas density as well as a simultaneously reduced gas load for the pumping system result in an increased stripping efficiency, while the beam emittance remains the same. A new record intensity (7.8 emA for ^{238}U^{28+} beams at 1.4  MeV/u has been achieved applying the pulsed high density H_{2} stripper target to a high intensity ^{238}U^{4+} beam from the VARIS ion source with a newly developed extraction system. The experimental results are presented in detail.

Thermal stability of hexagonal OsB2

Science.gov (United States)

Xie, Zhilin; Blair, Richard G.; Orlovskaya, Nina; Cullen, David A.; Andrew Payzant, E.

2014-11-01

The synthesis of novel hexagonal ReB2-type OsB2 ceramic powder was performed by high energy ball milling of elemental Os and B powders. Two different sources of B powder have been used for this mechanochemical synthesis. One B powder consisted of a mixture of amorphous and crystalline phases and a mixture of 10B and 11B isotopes with a fine particle size, while another B powder was a purely crystalline (rhombohedral) material consisting of enriched 11B isotope with coarse particle size. The same Os powder was used for the synthesis in both cases. It was established that, in the first case, the hexagonal OsB2 phase was the main product of synthesis with a small quantity of Os2B3 phase present after synthesis as an intermediate product. In the second case, where coarse crystalline 11B powder was used as a raw material, only Os2B3 boride was synthesized mechanochemically. The thermal stability of hexagonal OsB2 powder was studied by heating under argon up to 876 °C and cooling in vacuo down to -225 °C. During the heating, the sacrificial reaction 2OsB2+3O2→2Os+2B2O3 took place due to presence of O2/water vapor molecules in the heating chamber, resulting in the oxidation of B atoms and formation of B2O3 and precipitation of Os metal out of the OsB2 lattice. As a result of such phase changes during heating, the lattice parameters of hexagonal OsB2 changed significantly. The shrinkage of the a lattice parameter was recorded in 276-426 °C temperature range upon heating, which was attributed to the removal of B atoms from the OsB2 lattice due to oxidation followed by the precipitation of Os atoms and formation of Os metal. While significant structural changes occurred upon heating due to presence of O2, the hexagonal OsB2 ceramic demonstrated good phase stability upon cooling in vacuo with linear shrinkage of the lattice parameters and no phase changes detected during cooling.

Signaling factors and pathways of α-particle irradiation induced bilateral bystander responses between Beas-2B and U937 cells

International Nuclear Information System (INIS)

Fu, Jiamei; Wang, Juan; Wang, Xiangdong; Wang, Ping; Xu, Jinping; Zhou, Cuiping; Bai, Yang; Shao, Chunlin

2016-01-01

Highlights: • Radiation damage of Beas-2B cells was enhanced by macrophage-mediated bilateral bystander responses. • Expressions of TNF-α and IL-8 in the α-irradiated Beas-2B cells were dependent on ERK and p38 pathways. • The neighboring U937 cells further increased the generation of TNF-α and IL-8 in the α-irradiated Beas-2B cells. • NF-κB dependent upregulation of TNF-α and IL-8 was induced in the bystander U937 cells. - Abstract: Although radiation induced bystander effects (RIBE) have been investigated for decades for their potential health risk, the underlying gene regulation is still largely unclear, especially the roles of immune system and inflammatory response in RIBE. In the present study, macrophage U937 cells and epithelial Beas-2B cells were co-cultured to disclose the cascades of bystander signaling factors and intercellular communications. After α-particle irradiation, both ERK and p38 pathways were activated in Beas-2B cells and were associated with the autocrine and paracrine signaling of TNF-α and IL-8, resulting in direct damage to the irradiated cells. Similar upregulation of TNF-α and IL-8 was induced in the bystander U937 cells after co-culture with α-irradiated Beas-2B cells. This upregulation was dependent on the activation of NF-κB pathway and was responsible for the enhanced damage of α-irradiated Beas-2B cells. Interestingly, the increased expressions of TNF-α and IL-8 mRNAs in the bystander U937 cells were clearly relayed on the activated ERK and p38 pathways in the irradiated Beas-2B cells, and the upregulation of TNF-α and IL-8 mRNAs in co-cultured Beas-2B cells was also partly due to the activated NF-κB pathway in the bystander U937 cells. With the pretreatment of U0126 (MEK1/2 inhibitor), SB203580 (p38 inhibitor) or BAY 11-7082 (NF-κB inhibitor), the aggravated damage in the α-irradiated Beas-2B cells could be largely alleviated. Our results disclosed novel signaling cascades of macrophage-mediated bilateral

Signaling factors and pathways of α-particle irradiation induced bilateral bystander responses between Beas-2B and U937 cells

Energy Technology Data Exchange (ETDEWEB)

Fu, Jiamei; Wang, Juan; Wang, Xiangdong; Wang, Ping; Xu, Jinping; Zhou, Cuiping; Bai, Yang; Shao, Chunlin, E-mail: clshao@shmu.edu.cn

2016-07-15

Highlights: • Radiation damage of Beas-2B cells was enhanced by macrophage-mediated bilateral bystander responses. • Expressions of TNF-α and IL-8 in the α-irradiated Beas-2B cells were dependent on ERK and p38 pathways. • The neighboring U937 cells further increased the generation of TNF-α and IL-8 in the α-irradiated Beas-2B cells. • NF-κB dependent upregulation of TNF-α and IL-8 was induced in the bystander U937 cells. - Abstract: Although radiation induced bystander effects (RIBE) have been investigated for decades for their potential health risk, the underlying gene regulation is still largely unclear, especially the roles of immune system and inflammatory response in RIBE. In the present study, macrophage U937 cells and epithelial Beas-2B cells were co-cultured to disclose the cascades of bystander signaling factors and intercellular communications. After α-particle irradiation, both ERK and p38 pathways were activated in Beas-2B cells and were associated with the autocrine and paracrine signaling of TNF-α and IL-8, resulting in direct damage to the irradiated cells. Similar upregulation of TNF-α and IL-8 was induced in the bystander U937 cells after co-culture with α-irradiated Beas-2B cells. This upregulation was dependent on the activation of NF-κB pathway and was responsible for the enhanced damage of α-irradiated Beas-2B cells. Interestingly, the increased expressions of TNF-α and IL-8 mRNAs in the bystander U937 cells were clearly relayed on the activated ERK and p38 pathways in the irradiated Beas-2B cells, and the upregulation of TNF-α and IL-8 mRNAs in co-cultured Beas-2B cells was also partly due to the activated NF-κB pathway in the bystander U937 cells. With the pretreatment of U0126 (MEK1/2 inhibitor), SB203580 (p38 inhibitor) or BAY 11-7082 (NF-κB inhibitor), the aggravated damage in the α-irradiated Beas-2B cells could be largely alleviated. Our results disclosed novel signaling cascades of macrophage-mediated bilateral

Effect and Mechanism of EGFL7 Downregulation in Human Osteosarcoma Cells on the Biological Function of Co-cultured HUVEC

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Xia Li

2018-03-01

Full Text Available Background: Even though epidermal growth factor-like domain 7 is known to be overexpressed in osteosarcoma and is associated with poor clinical outcome, few reports are available regarding its mechanism. Aims: The objective of this study was to explore the effect and mechanism of downregulating epidermal growth factor-like domain 7 expression in a human osteosarcoma cell line on the biological function of co-cultured human umbilical vein endothelial cells. Study Design: Cell study. Methods: In the present study, human osteosarcoma cell lines U2OS, Saos-2, HOS, and MG63, and normal human osteoblasts were cultured in Dulbecco’s Modified Eagle Medium containing 10% fetal bovine serum and 1x antibiotics at 37 °C and 5% CO2 in an incubator. Of the four osteosarcoma cell lines, U2OS expresses the highest level of epidermal growth factor-like domain 7 mRNA as determined using quantitative reverse transcription polymerase chain reaction. With the knockdown of epidermal growth factor-like domain 7 in U2OS and human umbilical vein endothelial cells by lentivirus, the proliferation and apoptosis of U2OS and human umbilical vein endothelial cells were investigated using MTT and flow cytometry assays. After the co-culture of human umbilical vein endothelial cells and epidermal growth factor-like domain 7-knockdown U2OS, the in vitro effects on cell proliferation, apoptosis, adhesion, migration, and the angiogenic ability of human umbilical vein endothelial cells were detected using MTT, flow cytometry, Transwell, and tube formation assays, respectively. The expressions of phosphoinositide 3-kinase, phospho-Akt, total Akt, and vascular endothelial growth factor in human umbilical vein endothelial cells were detected using western blot assay. Results: Lentivirus with epidermal growth factor-like domain 7 shRNA could not significantly affect the proliferation and apoptosis of both U2OS and human umbilical vein endothelial cells, whereas the knockdown of

Thermal stability of hexagonal OsB2

International Nuclear Information System (INIS)

Xie, Zhilin; Blair, Richard G.; Orlovskaya, Nina; Cullen, David A.; Andrew Payzant, E.

2014-01-01

The synthesis of novel hexagonal ReB 2 -type OsB 2 ceramic powder was performed by high energy ball milling of elemental Os and B powders. Two different sources of B powder have been used for this mechanochemical synthesis. One B powder consisted of a mixture of amorphous and crystalline phases and a mixture of 10 B and 11 B isotopes with a fine particle size, while another B powder was a purely crystalline (rhombohedral) material consisting of enriched 11 B isotope with coarse particle size. The same Os powder was used for the synthesis in both cases. It was established that, in the first case, the hexagonal OsB 2 phase was the main product of synthesis with a small quantity of Os 2 B 3 phase present after synthesis as an intermediate product. In the second case, where coarse crystalline 11 B powder was used as a raw material, only Os 2 B 3 boride was synthesized mechanochemically. The thermal stability of hexagonal OsB 2 powder was studied by heating under argon up to 876 °C and cooling in vacuo down to −225 °C. During the heating, the sacrificial reaction 2OsB 2 +3O 2 →2Os+2B 2 O 3 took place due to presence of O 2 /water vapor molecules in the heating chamber, resulting in the oxidation of B atoms and formation of B 2 O 3 and precipitation of Os metal out of the OsB 2 lattice. As a result of such phase changes during heating, the lattice parameters of hexagonal OsB 2 changed significantly. The shrinkage of the a lattice parameter was recorded in 276–426 °C temperature range upon heating, which was attributed to the removal of B atoms from the OsB 2 lattice due to oxidation followed by the precipitation of Os atoms and formation of Os metal. While significant structural changes occurred upon heating due to presence of O 2 , the hexagonal OsB 2 ceramic demonstrated good phase stability upon cooling in vacuo with linear shrinkage of the lattice parameters and no phase changes detected during cooling. - Graphical abstract: The in situ high temperature XRD

Lung cells support osteosarcoma cell migration and survival.

Science.gov (United States)

Yu, Shibing; Fourman, Mitchell Stephen; Mahjoub, Adel; Mandell, Jonathan Brendan; Crasto, Jared Anthony; Greco, Nicholas Giuseppe; Weiss, Kurt Richard

2017-01-25

Osteosarcoma (OS) is the most common primary bone tumor, with a propensity to metastasize to the lungs. Five-year survival for metastatic OS is below 30%, and has not improved for several decades despite the introduction of multi-agent chemotherapy. Understanding OS cell migration to the lungs requires an evaluation of the lung microenvironment. Here we utilized an in vitro lung cell and OS cell co-culture model to explore the interactions between OS and lung cells, hypothesizing that lung cells would promote OS cell migration and survival. The impact of a novel anti-OS chemotherapy on OS migration and survival in the lung microenvironment was also examined. Three human OS cell lines (SJSA-1, Saos-2, U-2) and two human lung cell lines (HULEC-5a, MRC-5) were cultured according to American Type Culture Collection recommendations. Human lung cell lines were cultured in growth medium for 72 h to create conditioned media. OS proliferation was evaluated in lung co-culture and conditioned media microenvironment, with a murine fibroblast cell line (NIH-3 T3) in fresh growth medium as controls. Migration and invasion were measured using a real-time cell analysis system. Real-time PCR was utilized to probe for Aldehyde Dehydrogenase (ALDH1) expression. Osteosarcoma cells were also transduced with a lentivirus encoding for GFP to permit morphologic analysis with fluorescence microscopy. The anti-OS efficacy of Disulfiram, an ALDH-inhibitor previously shown to inhibit OS cell proliferation and metastasis in vitro, was evaluated in each microenvironment. Lung-cell conditioned medium promoted osteosarcoma cell migration, with a significantly higher attractive effect on all three osteosarcoma cell lines compared to basic growth medium, 10% serum containing medium, and NIH-3 T3 conditioned medium (p cell conditioned medium induced cell morphologic changes, as demonstrated with GFP-labeled cells. OS cells cultured in lung cell conditioned medium had increased alkaline

Pressure induced structural phase transition of OsB 2: First-principles calculations

Science.gov (United States)

Ren, Fengzhu; Wang, Yuanxu; Lo, V. C.

2010-04-01

Orthorhombic OsB 2 was synthesized at 1000 °C and its compressibility was measured by using the high-pressure X-ray diffraction in a Diacell diamond anvil cell from ambient pressure to 32 GPa [R.W. Cumberland, et al. (2005)]. First-principles calculations were performed to study the possibility of the phase transition of OsB 2. An analysis of the calculated enthalpy shows that orthorhombic OsB 2 can transfer to the hexagonal phase at 10.8 GPa. The calculated results with the quasi-harmonic approximation indicate that this phase transition pressure is little affected by the thermal effect. The calculated phonon band structure shows that the hexagonal P 6 3/ mmc structure (high-pressure phase) is stable for OsB 2. We expect the phase transition can be further confirmed by the experimental work.

Chimaphilin inhibits human osteosarcoma cell invasion and metastasis through suppressing the TGF-β1-induced epithelial-to-mesenchymal transition markers via PI-3K/Akt, ERK1/2, and Smad signaling pathways.

Science.gov (United States)

Dong, Feng; Liu, Tingting; Jin, Hao; Wang, Wenbo

2018-01-01

Epithelial-to-mesenchymal transition is a cellular process associated with cancer invasion and metastasis. However, the antimetastatic effects of chimaphilin remain elusive. In this study, we attempted to investigate the potential use of chimaphilin as an inhibitor of TGF-β1-induced epithelial-to-mesenchymal transition in U2OS cells. We found that TGF-β1 induced epithelial-to-mesenchymal transition to promote U2OS cell invasion and metastasis. Western blotting demonstrated that chimaphilin inhibited U2OS cell invasion and migration, increased the expression of the epithelial phenotype marker E-cadherin, repressed the expression of the mesenchymal phenotype marker vimentin, as well as decreased the level of epithelial-to-mesenchymal-inducing transcription factors Snail1 and Slug during the initiation of TGF-β1-induced epithelial-to-mesenchymal transition. In this study, we revealed that chimaphilin up-regulated the E-cadherin expression level and inhibited the production of vimentin, Snail1, and Slug in TGF-β1-induced U2OS cells by blocking PI-3K/Akt and ERK 1/2 signaling pathway. Additionally, the TGF-β1-mediated phosphorylated levels of Smad2/3 were inhibited by chimaphilin pretreatment. Above all, we conclude that chimaphilin represents an effective inhibitor of the metastatic potential of U2OS cells through suppression of TGF-β1-induced epithelial-to-mesenchymal transition.

A rice tonoplastic calcium exchanger, OsCCX2 mediates Ca2+/cation transport in yeast

Science.gov (United States)

Yadav, Akhilesh K.; Shankar, Alka; Jha, Saroj K.; Kanwar, Poonam; Pandey, Amita; Pandey, Girdhar K.

2015-01-01

In plant cell, cations gradient in cellular compartments is maintained by synergistic action of various exchangers, pumps and channels. The Arabidopsis exchanger family members (AtCCX3 and AtCCX5) were previously studied and belong to CaCA (calcium cation exchangers) superfamily while none of the rice CCXs has been functionally characterized for their cation transport activities till date. Rice genome encode four CCXs and only OsCCX2 transcript showed differential expression under abiotic stresses and Ca2+ starvation conditions. The OsCCX2 localized to tonoplast and suppresses the Ca2+ sensitivity of K667 (low affinity Ca2+ uptake deficient) yeast mutant under excess CaCl2 conditions. In contrast to AtCCXs, OsCCX2 expressing K667 yeast cells show tolerance towards excess Na+, Li+, Fe2+, Zn2+ and Co2+ and suggest its ability to transport both mono as well as divalent cations in yeast. Additionally, in contrast to previously characterized AtCCXs, OsCCX2 is unable to complement yeast trk1trk2 double mutant suggesting inability to transport K+ in yeast system. These finding suggest that OsCCX2 having distinct metal transport properties than previously characterized plant CCXs. OsCCX2 can be used as potential candidate for enhancing the abiotic stress tolerance in plants as well as for phytoremediation of heavy metal polluted soil. PMID:26607171

Hyperpolarized [U-(2) H, U-(13) C]Glucose reports on glycolytic and pentose phosphate pathway activity in EL4 tumors and glycolytic activity in yeast cells.

Science.gov (United States)

Timm, Kerstin N; Hartl, Johannes; Keller, Markus A; Hu, De-En; Kettunen, Mikko I; Rodrigues, Tiago B; Ralser, Markus; Brindle, Kevin M

2015-12-01

A resonance at ∼181 ppm in the (13) C spectra of tumors injected with hyperpolarized [U-(2) H, U-(13) C]glucose was assigned to 6-phosphogluconate (6PG), as in previous studies in yeast, whereas in breast cancer cells in vitro this resonance was assigned to 3-phosphoglycerate (3PG). These peak assignments were investigated here using measurements of 6PG and 3PG (13) C-labeling using liquid chromatography tandem mass spectrometry (LC-MS/MS) METHODS: Tumor-bearing mice were injected with (13) C6 glucose and the (13) C-labeled and total 6PG and 3PG concentrations measured. (13) C MR spectra of glucose-6-phosphate dehydrogenase deficient (zwf1Δ) and wild-type yeast were acquired following addition of hyperpolarized [U-(2) H, U-(13) C]glucose and again (13) C-labeled and total 6PG and 3PG were measured by LC-MS/MS RESULTS: Tumor (13) C-6PG was more abundant than (13) C-2PG/3PG and the resonance at ∼181 ppm matched more closely that of 6PG. (13) C MR spectra of wild-type and zwf1Δ yeast cells showed a resonance at ∼181 ppm after labeling with hyperpolarized [U-(2) H, U-(13) C]glucose, however, there was no 6PG in zwf1Δ cells. In the wild-type cells 3PG was approximately four-fold more abundant than 6PG CONCLUSION: The resonance at ∼181 ppm in (13) C MR spectra following injection of hyperpolarized [U-(2) H, U-(13) C]glucose originates predominantly from 6PG in EL4 tumors and 3PG in yeast cells. © 2014 Wiley Periodicals, Inc.

Polycomb Protein OsFIE2 Affects Plant Height and Grain Yield in Rice.

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Xianbo Liu

Full Text Available Polycomb group (PcG proteins have been shown to affect growth and development in plants. To further elucidate their role in these processes in rice, we isolated and characterized a rice mutant which exhibits dwarfism, reduced seed setting rate, defective floral organ, and small grains. Map-based cloning revealed that abnormal phenotypes were attributed to a mutation of the Fertilization Independent Endosperm 2 (OsFIE2 protein, which belongs to the PcG protein family. So we named the mutant as osfie2-1. Histological analysis revealed that the number of longitudinal cells in the internodes decreased in osfie2-1, and that lateral cell layer of the internodes was markedly thinner than wild-type. In addition, compared to wild-type, the number of large and small vascular bundles decreased in osfie2-1, as well as cell number and cell size in spikelet hulls. OsFIE2 is expressed in most tissues and the coded protein localizes in both nucleus and cytoplasm. Yeast two-hybrid and bimolecular fluorescence complementation assays demonstrated that OsFIE2 interacts with OsiEZ1 which encodes an enhancer of zeste protein previously identified as a histone methylation enzyme. RNA sequencing-based transcriptome profiling and qRT-PCR analysis revealed that some homeotic genes and genes involved in endosperm starch synthesis, cell division/expansion and hormone synthesis and signaling are differentially expressed between osfie2-1 and wild-type. In addition, the contents of IAA, GA3, ABA, JA and SA in osfie2-1 are significantly different from those in wild-type. Taken together, these results indicate that OsFIE2 plays an important role in the regulation of plant height and grain yield in rice.

Izrada 2D video igre za iOS platformu

OpenAIRE

Kampuš, Dominik

2016-01-01

Tema ovog završnog rada temelji se na izradi 2D video igre za iOS mobilni uređaj te njezinoj demonstraciji na istom. Kroz rad su opisane sve bitne funkcije GameSalad Creator-a koje su potrebne kod izrade igre bazirane na 2 dimenzije. Također se prolazi kroz iOS operativni sustav, što je on i kako se razvijao. Spominje se i tema koja govori općenito o igrama na mobilnim uređajima. U završnom dijelu rada prikazan je postupak izrade, koje funkcije programa se točno koriste i kako se igra može te...

Pressure induced structural phase transition of OsB2: First-principles calculations

International Nuclear Information System (INIS)

Ren Fengzhu; Wang Yuanxu; Lo, V.C.

2010-01-01

Orthorhombic OsB 2 was synthesized at 1000 deg. C and its compressibility was measured by using the high-pressure X-ray diffraction in a Diacell diamond anvil cell from ambient pressure to 32 GPa [R.W. Cumberland, et al. (2005)]. First-principles calculations were performed to study the possibility of the phase transition of OsB 2 . An analysis of the calculated enthalpy shows that orthorhombic OsB 2 can transfer to the hexagonal phase at 10.8 GPa. The calculated results with the quasi-harmonic approximation indicate that this phase transition pressure is little affected by the thermal effect. The calculated phonon band structure shows that the hexagonal P 6 3 /mmc structure (high-pressure phase) is stable for OsB 2 . We expect the phase transition can be further confirmed by the experimental work. - Abstract: Graphical Abstract Legend (TOC Figure): Table of Contents Figure Pressure induced structural phase transition from the orthorhombic structure to the hexagonal one for OsB 2 takes place under 10.8 GPa (0 K), 10.35 GPa (300, 1000 K) by the first-principles predictions.

MicroRNA-29b-1 impairs in vitro cell proliferation, self‑renewal and chemoresistance of human osteosarcoma 3AB-OS cancer stem cells.

Science.gov (United States)

Di Fiore, Riccardo; Drago-Ferrante, Rosa; Pentimalli, Francesca; Di Marzo, Domenico; Forte, Iris Maria; D'Anneo, Antonella; Carlisi, Daniela; De Blasio, Anna; Giuliano, Michela; Tesoriere, Giovanni; Giordano, Antonio; Vento, Renza

2014-11-01

Osteosarcoma (OS) is the most common type of bone cancer, with a peak incidence in the early childhood. Emerging evidence suggests that treatments targeting cancer stem cells (CSCs) within a tumor can halt cancer and improve patient survival. MicroRNAs (miRNAs) have been implicated in the maintenance of the CSC phenotype, thus, identification of CSC-related miRNAs would provide information for a better understanding of CSCs. Downregulation of miRNA-29 family members (miR-29a/b/c; miR‑29s) was observed in human OS, however, little is known about the functions of miR-29s in human OS CSCs. Previously, during the characterization of 3AB-OS cells, a CSC line selected from human OS MG63 cells, we showed a potent downregulation of miR-29b. In this study, after stable transfection of 3AB-OS cells with miR-29b-1, we investigated the role of miR-29b-1 in regulating cell proliferation, sarcosphere-forming ability, clonogenic growth, chemosensitivity, migration and invasive ability of 3AB-OS cells, in vitro. We found that, miR-29b-1 overexpression consistently reduced both, 3AB-OS CSCs growth in two- and three-dimensional culture systems and their sarcosphere- and colony-forming ability. In addition, while miR-29b-1 overexpression sensitized 3AB-OS cells to chemotherapeutic drug-induced apoptosis, it did not influence their migratory and invasive capacities, thus suggesting a context-depending role of miR-29b-1. Using publicly available databases, we proceeded to identify potential miR-29b target genes, known to play a role in the above reported functions. Among these targets we analyzed CD133, N-Myc, CCND2, E2F1 and E2F2, Bcl-2 and IAP-2. We also analyzed the most important stemness markers as Oct3/4, Sox2 and Nanog. Real-time RT-PCR and western-blot analyses showed that miR-29b-1 negatively regulated the expression of these markers. Overall, the results show that miR-29b-1 suppresses stemness properties of 3AB-OS CSCs and suggest that developing miR-29b-1 as a novel

The crosstalk between α-irradiated Beas-2B cells and its bystander U937 cells through MAPK and NF-κB signaling pathways.

Science.gov (United States)

Fu, Jiamei; Yuan, Dexiao; Xiao, Linlin; Tu, Wenzhi; Dong, Chen; Liu, Weili; Shao, Chunlin

2016-01-01

Although accumulated evidence suggests that α-particle irradiation induced bystander effect may relevant to lung injury and cancer risk assessment, the exact mechanisms are not yet elucidated. In the present study, a cell co-culture system was used to investigate the interaction between α-particle irradiated human bronchial epithelial cells (Beas-2B) and its bystander macrophage U937 cells. It was found that the cell co-culture amplified the detrimental effects of α-irradiation including cell viability decrease and apoptosis promotion on both irradiated cells and bystander cells in a feedback loop which was closely relevant to the activation of MAPK and NF-κB pathways in the bystander U937 cells. When these two pathways in U937 cells were disturbed by special pharmacological inhibitors before cell co-culture, it was found that a NF-κB inhibitor of BAY 11-7082 further enhanced the proliferation inhibition and apoptosis induction in bystander U937 cells, but MAPK inhibitors of SP600125 and SB203580 protected cells from viability loss and apoptosis and U0126 presented more beneficial effect on cell protection. For α-irradiated epithelial cells, the activation of NF-κB and MAPK pathways in U937 cells participated in detrimental cellular responses since the above inhibitors could largely attenuate cell viability loss and apoptosis of irradiated cells. Our results demonstrated that there are bilateral bystander responses between irradiated lung epithelial cells and macrophages through MAPK and NF-κB signaling pathways, which accounts for the enhancement of α-irradiation induced damage. Copyright © 2015 Elsevier B.V. All rights reserved.

Combination of etoposide and fisetin results in anti-cancer efficiency against osteosarcoma cell models.

Science.gov (United States)

Ferreira de Oliveira, José Miguel P; Pacheco, Ana Rita; Coutinho, Laura; Oliveira, Helena; Pinho, Sónia; Almeida, Luis; Fernandes, Eduarda; Santos, Conceição

2018-03-01

Osteosarcoma chemotherapy is often limited by chemoresistance, resulting in poor prognosis. Combined chemotherapy could, therefore, be used to prevent resistance to chemotherapeutics. Here, the effects of fisetin on osteosarcoma cells were investigated, as well as cytostatic potential in combination with the anti-cancer drug etoposide. For this, different osteosarcoma cell lines were treated with fisetin, with etoposide and with respective combinations. Fisetin was associated with decrease in colony formation in Saos-2 and in U2OS cells but not in MG-63 cells. Notwithstanding, upon evaluation of cellular growth by crystal violet assay, MG-63 and Saos-2 cells showed decreased cell proliferation at 40 and 20 µM fisetin, respectively. Depending on the relative concentrations, fisetin:etoposide combinations showed negative-to-positive interactions on the inhibition of cell proliferation. In addition, fisetin treatment up to 50 µM for 48 h resulted in G2-phase cell cycle arrest. Regardless of the combination, fisetin:etoposide increased % cells in G2-phase and decreased % cells in G1-phase. In addition, mixtures with more positive combined effects induced increased % cells in S-phase. Compared to etoposide treatment, these combinations resulted in decreased levels of cyclins B1 and E1, pointing to the role of these regulators in fisetin-induced cell cycle arrest. In conclusion, these results show that the combination of fisetin with etoposide has higher anti-proliferative effects in osteosarcoma associated with cell cycle arrest, allowing the use of lower doses of the chemotherapeutic agent, which has important implications for osteosarcoma treatment.

pOsNAR2.1:OsNAR2.1 expression enhances nitrogen uptake efficiency and grain yield in transgenic rice plants.

Science.gov (United States)

Chen, Jingguang; Fan, Xiaoru; Qian, Kaiyun; Zhang, Yong; Song, Miaoquan; Liu, Yu; Xu, Guohua; Fan, Xiaorong

2017-10-01

The nitrate (NO3-) transporter has been selected as an important gene maker in the process of environmental adoption in rice cultivars. In this work, we transferred another native OsNAR2.1 promoter with driving OsNAR2.1 gene into rice plants. The transgenic lines with exogenous pOsNAR2.1:OsNAR2.1 constructs showed enhanced OsNAR2.1 expression level, compared with wild type (WT), and 15 N influx in roots increased 21%-32% in response to 0.2 mm and 2.5 mm 15NO3- and 1.25 mm 15 NH 4 15 NO 3 . Under these three N conditions, the biomass of the pOsNAR2.1:OsNAR2.1 transgenic lines increased 143%, 129% and 51%, and total N content increased 161%, 242% and 69%, respectively, compared to WT. Furthermore in field experiments we found the grain yield, agricultural nitrogen use efficiency (ANUE), and dry matter transfer of pOsNAR2.1:OsNAR2.1 plants increased by about 21%, 22% and 21%, compared to WT. We also compared the phenotypes of pOsNAR2.1:OsNAR2.1 and pOsNAR2.1:OsNRT2.1 transgenic lines in the field, found that postanthesis N uptake differed significantly between them, and in comparison with the WT. Postanthesis N uptake (PANU) increased approximately 39% and 85%, in the pOsNAR2.1:OsNAR2.1 and pOsNAR2.1:OsNRT2.1 transgenic lines, respectively, possibly because OsNRT2.1 expression was less in the pOsNAR2.1:OsNAR2.1 lines than in the pOsNAR2.1:OsNRT2.1 lines during the late growth stage. These results show that rice NO 3 - uptake, yield and NUE were improved by increased OsNAR2.1 expression via its native promoter. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

NRF2 Signaling Negatively Regulates Phorbol-12-Myristate-13-Acetate (PMA-Induced Differentiation of Human Monocytic U937 Cells into Pro-Inflammatory Macrophages.

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Min-Gu Song

Full Text Available Blood monocytes are recruited to injured tissue sites and differentiate into macrophages, which protect against pathogens and repair damaged tissues. Reactive oxygen species (ROS are known to be an important contributor to monocytes' differentiation and macrophages' function. NF-E2-related factor 2 (NRF2, a transcription factor regulating cellular redox homeostasis, is known to be a critical modulator of inflammatory responses. We herein investigated the role of NRF2 in macrophage differentiation using the human monocytic U937 cell line and phorbol-12-myristate-13-acetate (PMA. In U937 cells with NRF2 silencing, PMA-stimulated cell adherence was significantly facilitated when compared to control U937 cells. Both transcript and protein levels for pro-inflammatory cytokines, including interleukine-1β (IL-1β, IL-6, and tumor necrosis factor-α (TNFα were highly elevated in PMA-stimulated NRF2-silenced U937 compared to the control. In addition, PMA-inducible secretion of monocyte chemotactic protein 1 (MCP-1 was significantly high in NRF2-silenced U937. As an underlying mechanism, we showed that NRF2-knockdown U937 retained high levels of cellular ROS and endoplasmic reticulum (ER stress markers expression; and subsequently, PMA-stimulated levels of Ca2+ and PKCα were greater in NRF2-knockdown U937 cells, which caused enhanced nuclear accumulation of nuclear factor-ҡB (NFҡB p50 and extracellular signal-regulated kinase (ERK-1/2 phosphorylation. Whereas the treatment of NRF2-silenced U937 cells with pharmacological inhibitors of NFҡB or ERK1/2 largely blocked PMA-induced IL-1β and IL-6 expression, indicating that these pathways are associated with cell differentiation. Taken together, our results suggest that the NRF2 system functions to suppress PMA-stimulated U937 cell differentiation into pro-inflammatory macrophages and provide evidence that the ROS-PKCα-ERK-NFҡB axis is involved in PMA-facilitated differentiation of NRF2-silenced U937

p53-dependent and p53-independent anticancer activity of a new indole derivative in human osteosarcoma cells

Energy Technology Data Exchange (ETDEWEB)

Cappadone, C., E-mail: concettina.cappadone@unibo.it [Department of Pharmacy and Biotechnology, University of Bologna, Bologna (Italy); Stefanelli, C. [Department for Life Quality Studies, University of Bologna, Rimini Campus, Rimini (Italy); Malucelli, E. [Department of Pharmacy and Biotechnology, University of Bologna, Bologna (Italy); Zini, M. [Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna (Italy); Onofrillo, C. [Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna (Italy); Locatelli, A.; Rambaldi, M.; Sargenti, A. [Department of Pharmacy and Biotechnology, University of Bologna, Bologna (Italy); Merolle, L. [ELETTRA–Sincrotrone Trieste S.C.p.A., Trieste (Italy); Farruggia, G. [Department of Pharmacy and Biotechnology, University of Bologna, Bologna (Italy); National Institute of Biostructures and Biosystems, Roma (Italy); Graziadio, A. [Department of Pharmacy and Biotechnology, University of Bologna, Bologna (Italy); Montanaro, L. [Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna (Italy); Iotti, S. [Department of Pharmacy and Biotechnology, University of Bologna, Bologna (Italy); National Institute of Biostructures and Biosystems, Roma (Italy)

2015-11-13

Osteosarcoma (OS) is the most common primary malignant tumor of bone, occurring most frequently in children and adolescents. The mechanism of formation and development of OS have been studied for a long time. Tumor suppressor pathway governed by p53 gene are known to be involved in the pathogenesis of osteosarcoma. Moreover, loss of wild-type p53 activity is thought to be a major predictor of failure to respond to chemotherapy in various human cancers. In previous studies, we described the activity of a new indole derivative, NSC743420, belonging to the tubulin inhibitors family, capable to induce apoptosis and arrest of the cell cycle in the G2/M phase of various cancer cell lines. However, this molecule has never been tested on OS cell line. Here we address the activity of NSC743420 by examine whether differences in the p53 status could influence its effects on cell proliferation and death of OS cells. In particular, we compared the effect of the tested molecule on p53-wild type and p53-silenced U2OS cells, and on SaOS2 cell line, which is null for p53. Our results demonstrated that NSC743420 reduces OS cell proliferation by p53-dependent and p53-independent mechanisms. In particular, the molecule induces proliferative arrest that culminate to apoptosis in SaOS2 p53-null cells, while it brings a cytostatic and differentiating effect in U2OS cells, characterized by the cell cycle arrest in G0/G1 phase and increased alkaline phosphatase activity. - Highlights: • The indole derivative NSC743420 induces antitumor effects on osteosarcoma cells. • p53 status could drive the activity of antitumor agents on osteosarcoma cells. • NSC743420 induces cytostatic and differentiating effects on U2OS cells. • NSC743420 causes apoptosis on p53-null SaOS2 cells.

p53-dependent and p53-independent anticancer activity of a new indole derivative in human osteosarcoma cells

International Nuclear Information System (INIS)

Cappadone, C.; Stefanelli, C.; Malucelli, E.; Zini, M.; Onofrillo, C.; Locatelli, A.; Rambaldi, M.; Sargenti, A.; Merolle, L.; Farruggia, G.; Graziadio, A.; Montanaro, L.; Iotti, S.

2015-01-01

Osteosarcoma (OS) is the most common primary malignant tumor of bone, occurring most frequently in children and adolescents. The mechanism of formation and development of OS have been studied for a long time. Tumor suppressor pathway governed by p53 gene are known to be involved in the pathogenesis of osteosarcoma. Moreover, loss of wild-type p53 activity is thought to be a major predictor of failure to respond to chemotherapy in various human cancers. In previous studies, we described the activity of a new indole derivative, NSC743420, belonging to the tubulin inhibitors family, capable to induce apoptosis and arrest of the cell cycle in the G2/M phase of various cancer cell lines. However, this molecule has never been tested on OS cell line. Here we address the activity of NSC743420 by examine whether differences in the p53 status could influence its effects on cell proliferation and death of OS cells. In particular, we compared the effect of the tested molecule on p53-wild type and p53-silenced U2OS cells, and on SaOS2 cell line, which is null for p53. Our results demonstrated that NSC743420 reduces OS cell proliferation by p53-dependent and p53-independent mechanisms. In particular, the molecule induces proliferative arrest that culminate to apoptosis in SaOS2 p53-null cells, while it brings a cytostatic and differentiating effect in U2OS cells, characterized by the cell cycle arrest in G0/G1 phase and increased alkaline phosphatase activity. - Highlights: • The indole derivative NSC743420 induces antitumor effects on osteosarcoma cells. • p53 status could drive the activity of antitumor agents on osteosarcoma cells. • NSC743420 induces cytostatic and differentiating effects on U2OS cells. • NSC743420 causes apoptosis on p53-null SaOS2 cells.

Thermal stability of hexagonal OsB{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Xie, Zhilin [Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, FL 32816 (United States); Blair, Richard G. [Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, FL 32816 (United States); Department of Physics, University of Central Florida, Orlando, FL 32816 (United States); Orlovskaya, Nina, E-mail: Nina.Orlovskaya@ucf.edu [Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, FL 32816 (United States); Cullen, David A. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Andrew Payzant, E. [Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

2014-11-15

The synthesis of novel hexagonal ReB{sub 2}-type OsB{sub 2} ceramic powder was performed by high energy ball milling of elemental Os and B powders. Two different sources of B powder have been used for this mechanochemical synthesis. One B powder consisted of a mixture of amorphous and crystalline phases and a mixture of {sup 10}B and {sup 11}B isotopes with a fine particle size, while another B powder was a purely crystalline (rhombohedral) material consisting of enriched {sup 11}B isotope with coarse particle size. The same Os powder was used for the synthesis in both cases. It was established that, in the first case, the hexagonal OsB{sub 2} phase was the main product of synthesis with a small quantity of Os{sub 2}B{sub 3} phase present after synthesis as an intermediate product. In the second case, where coarse crystalline {sup 11}B powder was used as a raw material, only Os{sub 2}B{sub 3} boride was synthesized mechanochemically. The thermal stability of hexagonal OsB{sub 2} powder was studied by heating under argon up to 876 °C and cooling in vacuo down to −225 °C. During the heating, the sacrificial reaction 2OsB{sub 2}+3O{sub 2}→2Os+2B{sub 2}O{sub 3} took place due to presence of O{sub 2}/water vapor molecules in the heating chamber, resulting in the oxidation of B atoms and formation of B{sub 2}O{sub 3} and precipitation of Os metal out of the OsB{sub 2} lattice. As a result of such phase changes during heating, the lattice parameters of hexagonal OsB{sub 2} changed significantly. The shrinkage of the a lattice parameter was recorded in 276–426 °C temperature range upon heating, which was attributed to the removal of B atoms from the OsB{sub 2} lattice due to oxidation followed by the precipitation of Os atoms and formation of Os metal. While significant structural changes occurred upon heating due to presence of O{sub 2}, the hexagonal OsB{sub 2} ceramic demonstrated good phase stability upon cooling in vacuo with linear shrinkage of the lattice

Disruption of the rice nitrate transporter OsNPF2.2 hinders root-to-shoot nitrate transport and vascular development

Science.gov (United States)

Li, Yuge; Ouyang, Jie; Wang, Ya-Yun; Hu, Rui; Xia, Kuaifei; Duan, Jun; Wang, Yaqin; Tsay, Yi-Fang; Zhang, Mingyong

2015-01-01

Plants have evolved to express some members of the nitrate transporter 1/peptide transporter family (NPF) to uptake and transport nitrate. However, little is known of the physiological and functional roles of this family in rice (Oryza sativa L.). Here, we characterized the vascular specific transporter OsNPF2.2. Functional analysis using cDNA-injected Xenopus laevis oocytes revealed that OsNPF2.2 is a low-affinity, pH-dependent nitrate transporter. Use of a green fluorescent protein tagged OsNPF2.2 showed that the transporter is located in the plasma membrane in the rice protoplast. Expression analysis showed that OsNPF2.2 is nitrate inducible and is mainly expressed in parenchyma cells around the xylem. Disruption of OsNPF2.2 increased nitrate concentration in the shoot xylem exudate when nitrate was supplied after a deprivation period; this result suggests that OsNPF2.2 may participate in unloading nitrate from the xylem. Under steady-state nitrate supply, the osnpf2.2 mutants maintained high levels of nitrate in the roots and low shoot:root nitrate ratios; this observation suggests that OsNPF2.2 is involved in root-to-shoot nitrate transport. Mutation of OsNPF2.2 also caused abnormal vasculature and retarded plant growth and development. Our findings demonstrate that OsNPF2.2 can unload nitrate from the xylem to affect the root-to-shoot nitrate transport and plant development. PMID:25923512

Glutathione transferase-M2-2 secreted from glioblastoma cell protects SH-SY5Y cells from aminochrome neurotoxicity.

Science.gov (United States)

Cuevas, Carlos; Huenchuguala, Sandro; Muñoz, Patricia; Villa, Monica; Paris, Irmgard; Mannervik, Bengt; Segura-Aguilar, Juan

2015-04-01

U373MG cells are able to take up aminochrome that induces glutathione transferase M2-2 (GSTM2) expression in a concentration-dependent manner where 100 µM aminochrome increases GSTM2 expression by 2.1-fold (P protects SH-SY5Y cells incubated with 10 µM aminochrome. The significant protection provided by U373MG-conditioned medium in SH-SY5Y cells incubated with aminochrome was dependent on GSTM2 internalization into SH-SY5Y cells as evidenced by (i) uptake of (14)C-GSTM2 released from U373MG cells into SH-SY5Y cells, a process inhibited by anti-GSTM2 antiserum; (ii) lack of protection of U373MG-conditioned medium in the presence of anti-GSTM2 antiserum on SH-SY5Y cells treated with aminochrome; and (iii) lack of protection of conditioned medium from U373MGsiGST6 that expresses an siRNA directed against GSTM2 on SH-SY5Y cells treated with aminochrome. In conclusion, our results demonstrated that U373MG cells protect SH-SY5Y cells against aminochrome neurotoxicity by releasing GSTM2 into the conditioned medium and subsequent internalization of GSTM2 into SH-SY5Y cells. These results suggest a new mechanism of protection of dopaminergic neurons mediated by astrocytes by releasing GSTM2 into the intersynaptic space and subsequent internalization into dopaminergic neuron in order to protect these cells against aminochrome neurotoxicity.

The upregulation of receptor activator NF-kappaB ligand expression by interleukin-1alpha and Porphyromonas endodontalis in human osteoblastic cells.

Science.gov (United States)

Chen, S-C; Huang, F-M; Lee, S-S; Li, M-Z; Chang, Y-C

2009-04-01

To investigate the receptor activator of nuclear factor-kappa B (NF-kappaB) ligand (RANKL) in osteoblastic cells stimulated with inflammatory mediators. The expression of RANKL in human osteoblastic cell line U2OS stimulated by pro-inflammatory cytokine interleukin (IL)-1alpha and black-pigmented bacteria Porphyromonas endodontalis was investigated by Western blot and enzyme-linked immunosorbent assay (ELISA). The significance of the results obtained from control and treated groups was statistically analysed by the paired Student's t-test. IL-1alpha was found to upregulate RANKL production in U2OS cells (P endodontalis also increased RANKL expression in U2OS cells after 4-h incubation period demonstrated by Western blot and ELISA (P endodontalis may be involved in developing apical periodontitis through the stimulation of RANKL production.

uPA/uPAR system activation drives a glycolytic phenotype in melanoma cells.

Science.gov (United States)

Laurenzana, Anna; Chillà, Anastasia; Luciani, Cristina; Peppicelli, Silvia; Biagioni, Alessio; Bianchini, Francesca; Tenedini, Elena; Torre, Eugenio; Mocali, Alessandra; Calorini, Lido; Margheri, Francesca; Fibbi, Gabriella; Del Rosso, Mario

2017-09-15

In this manuscript, we show the involvement of the uPA/uPAR system in the regulation of aerobic glycolysis of melanoma cells. uPAR over-expression in human melanoma cells controls an invasive and glycolytic phenotype in normoxic conditions. uPAR down-regulation by siRNA or its uncoupling from integrins, and hence from integrin-linked tyrosine kinase receptors (IL-TKRs), by an antagonist peptide induced a striking inhibition of the PI3K/AKT/mTOR/HIF1α pathway, resulting into impairment of glucose uptake, decrease of several glycolytic enzymes and of PKM2, a checkpoint that controls metabolism of cancer cells. Further, binding of uPA to uPAR regulates expression of molecules that govern cell invasion, including extracellular matrix metallo-proteinases inducer (EMPPRIN) and enolase, a glycolytyc enzyme that also serves as a plasminogen receptor, thus providing a common denominator between tumor metabolism and phenotypic invasive features. Such effects depend on the α5β1-integrin-mediated uPAR connection with EGFR in melanoma cells with engagement of the PI3K-mTOR-HIFα pathway. HIF-1α trans-activates genes whose products mediate tumor invasion and glycolysis, thus providing the common denominator between melanoma metabolism and its invasive features. These findings unveil a unrecognized interaction between the invasion-related uPAR and IL-TKRs in the control of glycolysis and disclose a new pharmacological target (i.e., uPAR/IL-TKRs axis) for the therapy of melanoma. © 2017 UICC.

Metallographic analysis of irradiated U3Si2/Al fuel element plate of 2.96 gU/cm3 density

International Nuclear Information System (INIS)

Maman Kartaman Ajiriyanto; Aslina Br Ginting; Junaedi

2018-01-01

Metallographic analysis of U 3 Si 2 /Al fuel element plate has been performed in hot cell. The purpose of metallographic analysis is to study changes in PEB U 3 Si 2 /Al microstructure and AlMg 2 cladding thickness after irradiation in reactor until burn up of 56 %. The fuel element plate of irradiated U 3 Si 2 /Al was cut in top, middle and bottom positions with each size around 5 x 5 x 1.37 mm. Metallographic preparation starts from sample cutting using cutting machine with low speed and sample mounting, grinding and polishing in hot cell 104–105. Sample mounting was done by using resin for more than 10 hours followed by grinding with sand papers up to grit size of 2400 and polishing with diamond paste of size 3 to 1 micron at a rotational speed of 150 rpm for 5 minutes. Microstructure observation was performed with optical microscope in hot cell 107 at 200 times magnification. Microstructure examination reveals U 3 Si 2 particles with inverse forms and sizes, Al matrix and AlMg 2 cladding were spread along the U 3 Si 2 /Al side. Microstructure observation of irradiated U 3 Si 2 /Al has not shown good result because only topography observation of U 3 Si 2 /Al meat, Al matrix and AlMg 2 cladding can be done due to limited capability of the optical microscope in hot cell, where maximum magnification can be attained only at 200 times so that the phenomenon of interaction layer and small gas bubble can not be observed. However, U 3 Si 2 /Al microstructure of 56 % burnup, if compared to the microstructure of U 3 Si 2 /Al fuel element plate of 60 % burnup from previous researcher, shows interaction between U 3 Si 2 meat with Al matrix and the existence of layers with a thickness about 5 up to 20 microns. Meanwhile, the observed thickness of AlMg 2 cladding is greater than 0.25 mm, which indicates that irradiation does not significantly change the thickness of AlMg 2 cladding so that the overall irradiated U 3 Si 2 -Al still has good integrity and stability. (author)

Apoptotic Effect of Nigella sativa on Human Lymphoma U937 Cells.

Science.gov (United States)

Arslan, Belkis Atasever; Isik, Fatma Busra; Gur, Hazal; Ozen, Fatih; Catal, Tunc

2017-10-01

Nigella sativa is from botanical Ranunculaceae family and commonly known as black seed. Apoptotic effect of N. sativa and its apoptotic signaling pathways on U937 lymphoma cells are unknown. In this study, we investigated selective cytotoxic and apoptotic effects of N. sativa extract and its apoptotic mechanisms on U937 cells. In addition, we also studied selective cytotoxic activity of thymoquinone that is the most active essential oil of N. sativa . Our results showed that N. sativa extract has selective cytotoxicity and apoptotic effects on U937 cells but not ECV304 control cells. However, thymoquinone had no significant cytotoxicity against on both cells. N. sativa extract increased significantly caspase-3, BAD, and p53 gene expressions in U937 cells. N. sativa may have anticancer drug potential and trigger p53-induced apoptosis in U937 lymphoma cells. This is the first study showing the apoptotic effect of Nigella sativa extract on U937 cells. Abbreviations used: CI: Cytotoxicity index, DMEM: Dulbecco's Modified Eagle Medium, HL: Hodgkin's lymphoma, MTT: 3-(4,5-dimethy lthiazol-2yl)-2,5-diphenyl tetrazolium bromide, RPMI: Roswell Park Memorial Institute medium.

TMX-U experimental results

International Nuclear Information System (INIS)

Simonen, T.C.; Allen, S.L.; Casper, T.A.

1983-01-01

This paper describes results from the Tandem Mirror Experiment-Upgrade (TMX-U). Mirror-confined electrons with 30 to 70 keV mean energy densities of 0.5 to 2.0 x 10 12 cm -3 and average betas of 3 to 5% are produced using electron-cyclotron resonant heating (ECRH). These results are consistent with an electron Fokker-Planck code. Improved ion-cyclotron microstability is observed using neutral beam injection at 47 0 to the magnetic axis, rather than at 90 0 as in the previous experiment, TMX. Strong end plugging has been produced using a combination of ECRH gyrotrons with sloshing-ion beam injection. In these low-density central cell experiments (3 x 10 11 cm -3 ) the axial losses (tau/sub parallel/ = 20 to 80 ms) are smaller than the nonambipolar radial losses (tau/sub perpendicular/ = 4 to 8 ms). Plugging has been achieved with a central cell density double that of the end plugs. Although no direct measurements are yet available to determine if a thermal barrier potential dip is generated, these experiments support many theoretical features of the thermal barrier concept

Role of Nrf2 in preventing oxidative stress induced chloride current alteration in human lung cells.

Science.gov (United States)

Canella, Rita; Benedusi, Mascia; Martini, Marta; Cervellati, Franco; Cavicchio, Carlotta; Valacchi, Giuseppe

2018-08-01

The lung tissue is one of the main targets of oxidative stress due to external sources and respiratory activity. In our previous work, we have demonstrated in that O 3 exposure alters the Cl - current-voltage relationship, with the appearance of a large outward rectifier component mainly sustained by outward rectifier chloride channels (ORCCs) in human lung epithelial cells (A549 line). In the present study, we have performed patch clamp experiments, in order to identify which one of the O 3 byproducts (4hydroxynonenal (HNE) and/or H 2 O 2 ) was responsible for chloride current change. While 4HNE exposition (up to 25 μM for 30' before electrophysiological analysis) did not reproduce O 3 effect, H 2 O 2 produced by glucose oxidase 10 mU for 24 hr before electrophysiological analysis mimicked O 3 response. This result was confirmed treating the cell with catalase (CAT) before O 3 exposure (1,000 U/ml for 2 hr): CAT was able to rescue Cl - current alteration. Since CAT is regulated by Nrf2 transcription factor, we pre-treated the cells with the Nrf2 activators, resveratrol and tBHQ. Immunochemical and immunocytochemical results showed Nrf2 activation with both substances that lead to prevent OS effect on Cl - current. These data bring new insights into the mechanisms involved in OS-induced lung tissue damage, pointing out the role of H 2 O 2 in chloride current alteration and the ability of Nfr2 activation in preventing this effect. © 2017 Wiley Periodicals, Inc.

U6 snRNA expression prevents toxicity in TDP-43-knockdown cells.

Directory of Open Access Journals (Sweden)

Masao Yahara

Full Text Available Depletion of amyotrophic lateral sclerosis (ALS-associated transactivation response (TAR RNA/DNA-binding protein 43 kDa (TDP-43 alters splicing efficiency of multiple transcripts and results in neuronal cell death. TDP-43 depletion can also disturb expression levels of small nuclear RNAs (snRNAs as spliceosomal components. Despite this knowledge, the relationship between cell death and alteration of snRNA expression during TDP-43 depletion remains unclear. Here, we knocked down TDP-43 in murine neuroblastoma Neuro2A cells and found a time lag between efficient TDP-43 depletion and appearance of cell death, suggesting that several mechanisms mediate between these two events. The amount of U6 snRNA was significantly decreased during TDP-43 depletion prior to increase of cell death, whereas that of U1, U2, and U4 snRNAs was not. Downregulation of U6 snRNA led to cell death, whereas transient exogenous expression of U6 snRNA counteracted the effect of TDP-43 knockdown on cell death, and slightly decreased the mis-splicing rate of Dnajc5 and Sortilin 1 transcripts, which are assisted by TDP-43. These results suggest that regulation of the U6 snRNA expression level by TDP-43 is a key factor in the increase in cell death upon TDP-43 loss-of-function.

Repair of U/G and U/A in DNA by UNG2-associated repair complexes takes place predominantly by short-patch repair both in proliferating and growth-arrested cells

DEFF Research Database (Denmark)

Akbari, Mansour; Otterlei, Marit; Pena Diaz, Javier

2004-01-01

Nuclear uracil-DNA glycosylase UNG2 has an established role in repair of U/A pairs resulting from misincorporation of dUMP during replication. In antigen-stimulated B-lymphocytes UNG2 removes uracil from U/G mispairs as part of somatic hypermutation and class switch recombination processes. Using......, PCNA and DNA ligase, the latter detected as activity. Short-patch repair was the predominant mechanism both in extracts and UNG2-ARC from proliferating and less BER-proficient growth-arrested cells. Repair of U/G mispairs and U/A pairs was completely inhibited by neutralizing UNG...

CrxOS maintains the self-renewal capacity of murine embryonic stem cells

International Nuclear Information System (INIS)

Saito, Ryota; Yamasaki, Tokiwa; Nagai, Yoko; Wu, Jinzhan; Kajiho, Hiroaki; Yokoi, Tadashi; Noda, Eiichiro; Nishina, Sachiko; Niwa, Hitoshi; Azuma, Noriyuki; Katada, Toshiaki; Nishina, Hiroshi

2009-01-01

Embryonic stem (ES) cells maintain pluripotency by self-renewal. Several homeoproteins, including Oct3/4 and Nanog, are known to be key factors in maintaining the self-renewal capacity of ES cells. However, other genes required for the mechanisms underlying this process are still unclear. Here we report the identification by in silico analysis of a homeobox-containing gene, CrxOS, that is specifically expressed in murine ES cells and is essential for their self-renewal. ES cells mainly express the short isoform of endogenous CrxOS. Using a polyoma-based episomal expression system, we demonstrate that overexpression of the CrxOS short isoform is sufficient for maintaining the undifferentiated morphology of ES cells and stimulating their proliferation. Finally, using RNA interference, we show that CrxOS is essential for the self-renewal of ES cells, and provisionally identify foxD3 as a downstream target gene of CrxOS. To our knowledge, ours is the first delineation of the physiological role of CrxOS in ES cells.

In vitro incorporation studies of 99mTc-alendronate sodium at different bone cell lines

International Nuclear Information System (INIS)

Evren Gundogdu; Derya Ilem-Ozdemir; Makbule Asikoglu

2014-01-01

Bisphosphonates can be labeled with Technetium-99m ( 99m Tc) and are used for bone imaging because of their good localization in the skeleton and rapid clearance from soft tissues. Over the last decades bone scintigraphy has been used extensively in the evaluation of oncological patients to provide information about the sites of bone lesions, their prognosis and the effectiveness of therapy by showing the sequential changes in tracer uptake. Since the lesion visualization and lesion/bone ratio are important utilities for a bone scanning radiopharmaceutic; in this study incorporation of 99m Tc labeled alendronate sodium ( 99m Tc-ALD) was evaluated in U 2 OS (human bone osteosarcoma) and NCI-H209 (human bone carcinoma) cell lines. ALD was directly labeled by 99m Tc, radiochemical purity and stability of the complex were analyzed by radioactive thin layer chromatography and radioactive high performance liquid chromatography studies. For cell incorporation study, NCI-H209 and U 2 OS cell lines were used with standard cell culture methods. The six well plates were used for all experiments and the integrity of each cell monolayer was checked by measuring its transepithelial electrical resistance (TEER) with an epithelial voltammeter. Results confirmed that ALD was successfully radiolabeled with 99m Tc. 99m Tc-ALD incorporated with NCI-H209 and U 2 OS cells. The uptake percentages of 99m Tc-ALD in NCI-H209 and U 2 OS cell lines were found significantly different. Since 99m Tc-ALD highly uptake in cancer cell line, the results demonstrated that radiolabeled ALD may be a promising agent for bone cancer diagnosis. (author)

Less initial rejoining of X-ray-induced DNA double-strand breaks in cells of a small cell (U-1285) compared to a large cell (U-1810) lung carcinoma cell line

International Nuclear Information System (INIS)

Cedervall, B.; Sirzea, F.; Brodin, O.; Lewensohn, R.

1994-01-01

Cells of a small cell lung carcinoma cell line, U-1285, and an undifferentiated large cell lung carcinoma cell line, U-1810, differ in radiosensitivity in parallel to the clinical radiosensitivity of the kind of tumors from which they are derived. The surviving fraction at 2 Gy (SF2) was 0.25 that of U-1285 cells and 0.88 that of U-1810 cells. We investigated the induction of DNA double-strand breaks (DSBs) by X rays and DSB rejoining in these cell lines. To estimate the number of DSBs we used a model adapted for pulsed-field gel electrophoresis (PFGE). The induction levels were of the same magnitude. These levels of induction do not correlate with radiosensitivity as measured by cell survival assays. Rejoining of DSBs after doses in the range of 0.50 Gy was followed for 0,15,30,60 and 120 min. We found a difference in the velocity of repair during the first hour after irradiation which is parallel to the differences in radiosensitivity. Thus U-1810 cells exhibit a fast component of repair, with about half of the DSBs being rejoined during the first 15 min, whereas U-1285 cells lack such a fast component, with only about 5% of the DSBs being rejoined after the same time. In addition there was a numerical albeit not statistical difference at 120 min, with more residual DSBs in the U-1285 cells compared to the U-1810 cells. 36 refs., 5 figs

Five Year Results of US Intergroup/RTOG 9704 With Postoperative CA 19-9 {<=}90 U/mL and Comparison to the CONKO-001 Trial

Energy Technology Data Exchange (ETDEWEB)

Berger, Adam C., E-mail: adam.berger@jefferson.edu [Thomas Jefferson University Hospital, Philadelphia, Pennsylvania (United States); Winter, Kathryn [RTOG Statistical Center, Philadelphia, Pennsylvania (United States); Hoffman, John P. [Fox Chase Cancer Center, Philadelphia, Pennsylvania (United States); Regine, William F. [University of Maryland Medical Systems, Baltimore, Maryland (United States); Abrams, Ross A. [Rush University Medical Center, Chicago, Illinois (United States); Safran, Howard [Division of Hematology/Oncology, The Miriam Hospital, Providence, Rhode Island (United States); Freedman, Gary M. [Fox Chase Cancer Center, Philadelphia, Pennsylvania (United States); Benson, Alan B. [Northwestern Memorial Hospital, Chicago, Illinois (United States); MacDonald, John [St. Vincent' s Comprehensive Cancer Center, New York, New York (United States); Willett, Christopher G. [Duke University Medical Center, Durham, North Carolina (United States)

2012-11-01

Purpose: Radiation Therapy Oncology Group (RTOG) trial 9704 was the largest randomized trial to use adjuvant chemoradiation therapy for patients with pancreatic cancer. This report analyzes 5-year survival by serum level of tumor marker CA 19-9 of {<=}90 vs >90 U/mL and compares results to the those of the CONKO-001 trial. Methods and Materials: CA 19-9 expression was analyzed as a dichotomized variable ({<=}90 vs >90 U/mL). Cox proportional hazard models were used to identify the impact of the CA 19-9 value on overall survival (OS). Actuarial estimates of OS were calculated using the Kaplan-Meier method. Results: Both univariate (hazard ratio [HR] = 3.2; 95% confidence interval [CI], 2.3-4.3, P<.0001) and multivariate (HR = 3.1; 95% CI, 2.2-4.2, P<.0001) analyses demonstrated a statistically significant decrease in OS for CA 19-9 serum level of {>=}90 U/mL. For patients in the gemcitabine (Gem) treatment arm with CA 19-9 <90 U/mL, median survival was 21 months. For patients with CA 19-9 {>=}90 U/mL, this number dropped to 10 months. In patients with pancreatic head tumors in the Gem treatment arm with RT quality assurance per protocol and CA 19-9 of <90 U/mL, median survival and 5-year rate were 24 months and 34%. In comparison, the median survival and 5-year OS rate for patients in the Gem arm of the CONKO trial were 22 months and 21%. Conclusions: This analysis demonstrates that patients with postresection CA 19-9 values {>=}90 U/mL had a significantly worse survival. Patients with pancreatic head tumors treated with Gem with CA 19-9 serum level of <90 U/mL and per protocol RT had favorable survival compared to that seen in the CONKO trial. CA 19-9 is a stratification factor for the current RTOG adjuvant pancreas trial (0848).

Che-1 gene silencing induces osteosarcoma cell apoptosis by inhibiting mutant p53 expression

Energy Technology Data Exchange (ETDEWEB)

Liu, Ming; Wang, Dan, E-mail: danwangwdd@163.com; Li, Ning

2016-04-22

The transcriptional cofactor Che-1 is an RNA polymerase II (Pol II) which is involved in tumorigenesis, such as breast cancer and multiple myeloma. Che-1 can also regulate mutant p53 expression, which plays roles in many types of cancer. In this study, we aimed to investigate the effects and specific mechanism of Che-1 in the regulation of osteosarcoma (OS) cell growth. We found that Che-1 is highly expressed in several kinds of OS cells compared with osteoblast hFOB1.19 cells. MTT and flow cytometry assays showed that Che-1 depletion by siRNA markedly suppressed MG-63 and U2OS cell proliferation and promoted apoptosis. The chromatin immunoprecipitation (ChIP) assay verified the presence of Che-1 on the p53 promoter in MG-63 and U2OS cells carrying mutant p53. Further studies showed that Che-1 depletion inhibited mutant p53 expression. Notably, our study showed that the loss of Che-1 inhibits proliferation and promotes apoptosis in MG-63 cells by decreasing the level of mutant p53. Therefore, these findings open the possibility that silencing of Che-1 will have therapeutic benefit in OS. - Highlights: • Che-1 is highly expressed in several kinds of OS cells. • Che-1 depletion suppressed MG-63 and U2OS cell growth. • Che-1 is existed in the p53 promoter in MG-63 and U2OS cells. • Che-1 depletion inhibited mutant p53 expression. • Che-1 depletion inhibits cell growth by decreasing the level of mutant p53.

The neuropeptide neuromedin U stimulates innate lymphoid cells and type 2 inflammation

DEFF Research Database (Denmark)

Klose, Christoph S N; Mahlakõiv, Tanel; Moeller, Jesper B

2017-01-01

The type 2 cytokines interleukin (IL)-4, IL-5, IL-9 and IL-13 have important roles in stimulating innate and adaptive immune responses that are required for resistance to helminth infection, promotion of allergic inflammation, metabolic homeostasis and tissue repair. Group 2 innate lymphoid cells......-localize with cholinergic neurons that express the neuropeptide neuromedin U (NMU). In contrast to other haematopoietic cells, ILC2s selectively express the NMU receptor 1 (NMUR1). In vitro stimulation of ILC2s with NMU induced rapid cell activation, proliferation, and secretion of the type 2 cytokines IL-5, IL-9 and IL-13...... that was dependent on cell-intrinsic expression of NMUR1 and Gαq protein. In vivo administration of NMU triggered potent type 2 cytokine responses characterized by ILC2 activation, proliferation and eosinophil recruitment that was associated with accelerated expulsion of the gastrointestinal nematode Nippostrongylus...

Electronic, structural and magnetic studies of niobium borides of group 8 transition metals, Nb2MB2 (M=Fe, Ru, Os) from first principles calculations

International Nuclear Information System (INIS)

Touzani, Rachid St.; Fokwa, Boniface P.T.

2014-01-01

The Nb 2 FeB 2 phase (U 3 Si 2 -type, space group P4/mbm, no. 127) is known for almost 50 years, but until now its magnetic properties have not been investigated. While the synthesis of Nb 2 OsB 2 (space group P4/mnc, no. 128, a twofold superstructure of U 3 Si 2 -type) with distorted Nb-layers and Os 2 -dumbbells was recently achieved, “Nb 2 RuB 2 ” is still not synthesized and its crystal structure is yet to be revealed. Our first principles density functional theory (DFT) calculations have confirmed not only the experimental structures of Nb 2 FeB 2 and Nb 2 OsB 2 , but also predict “Nb 2 RuB 2 ” to crystalize with the Nb 2 OsB 2 structure type. According to chemical bonding analysis, the homoatomic B–B interactions are optimized and very strong, but relatively strong heteroatomic M–B, B–Nb and M–Nb bonds (M=Fe, Ru, Os) are also found. These interactions, which together build a three-dimensional network, are mainly responsible for the structural stability of these ternary borides. The density-of-states at the Fermi level predicts metallic behavior, as expected, from metal-rich borides. Analysis of possible magnetic structures concluded preferred antiferromagnetic ordering for Nb 2 FeB 2 , originating from ferromagnetic interactions within iron chains and antiferromagnetic exchange interactions between them. -- Graphical abstract: Nb 2 FeB 2 (U 3 Si 2 structure type, space group P4/mbm, no. 127) is predicted to order antiferromagnetically, due to the presence of iron chains which show ferromagnetic interactions in the chains and antiferromagnetic interactions between them. “Nb 2 RuB 2 ” is predicted to crystallize with the recently discovered Nb 2 OsB 2 twofold superstructure (space group P4/mnc, no. 128) of U 3 Si 2 structure type. The building of ruthenium dumbbells instead of chains along [001] is found to be responsible for the stabilization of this superstructure. Highlights: • Nb 2 FeB 2 is predicted to order antiferromagnetically. �

Mixed oxides forming in CdO-OsO2 and PbO-OsO2 systems

International Nuclear Information System (INIS)

Shaplygin, I.S.; Lazarev, V.B.

1978-01-01

The formation of mixed oxides in systems CdO-OsO 2 and PbO-OsO 2 was studied by derivatography, X-ray phase analysis, and IR spectroscopy. It was established that in the system CdO-OsO 2 cubic phases of Cdsub(2)Ossub(2)Osub(6.7) and Cdsub(2)Ossub(2)Osub(7.2) with a pyrochlor-type structure, as well as new compounds with the structure of rhombic perovskite CdOsO 3 and Cd(Cdsub(0.5)Ossub(0.5))Osub(3) containing osmium in the formal degree of oxidation +4 and +6, respectively, are formed. The thermal stability of the compounds obtained was studied and their electrical properties determined

Mobilo lietotņu datu drošība iOS vidē

OpenAIRE

Mõisja, Maksim

2015-01-01

Maģistra darba pamatā ir autora novērota problēma, ka daudzi viedtālruņu lietotāji glabā dažādus sensitīvus datus savos telefonos, nedomājot, ka tas nav droši. Autors ir izpētījis, kā iOS sistēma nodrošina lietotāja datu drošību, aprakstījis ievainojamības, kuras var ietekmēt gan izstrā-dātājus, gan lietotājus, ir apskatījis veidus, kā lietotājs un lietotnes izstrādātājs var realizēt datu drošību. Darba autors ir veicis iOS lietotņu analīzi, kuras rezultātā tika atrastas vairākas, kas, pēc au...

The Osmium(VIII) Oxofluoro Cations OsO(2)F(3)(+) and F(cis-OsO(2)F(3))(2)(+): Syntheses, Characterization by (19)F NMR Spectroscopy and Raman Spectroscopy, X-ray Crystal Structure of F(cis-OsO(2)F(3))(2)(+)Sb(2)F(11)(-), and Density Functional Theory Calculations of OsO(2)F(3)(+), ReO(2)F(3), and F(cis-OsO(2)F(3))(2)(+).

Science.gov (United States)

Casteel, William J.; Dixon, David A.; Mercier, Hélène P. A.; Schrobilgen, Gary J.

1996-07-17

Osmium dioxide tetrafluoride, cis-OsO(2)F(4), reacts with the strong fluoride ion acceptors AsF(5) and SbF(5) in anhydrous HF and SbF(5) solutions to form orange salts. Raman spectra are consistent with the formation of the fluorine-bridged diosmium cation F(cis-OsO(2)F(3))(2)(+), as the AsF(6)(-) and Sb(2)F(11)(-) salts, respectively. The (19)F NMR spectra of the salts in HF solution are exchange-averaged singlets occurring at higher frequency than those of the fluorine environments of cis-OsO(2)F(4). The F(cis-OsO(2)F(3))(2)(+)Sb(2)F(11)(-) salt crystallizes in the orthorhombic space group Imma. At -107 degrees C, a = 12.838(3) Å, b = 10.667(2) Å, c = 11.323(2) Å, V = 1550.7(8) Å(3), and Z = 4. Refinement converged with R = 0.0469 [R(w) = 0.0500]. The crystal structure consists of discrete fluorine-bridged F(cis-OsO(2)F(3))(2)(+) and Sb(2)F(11)(-) ions in which the fluorine bridge of the F(cis-OsO(2)F(3))(2)(+) cation is trans to an oxygen atom (Os-O 1.676 Å) of each OsO(2)F(3) group. The angle at the bridge is 155.2(8) degrees with a bridging Os---F(b) distance of 2.086(3) Å. Two terminal fluorine atoms (Os-F 1.821 Å) are cis to the two oxygen atoms (Os-O 1.750 Å), and two terminal fluorine atoms of the OsO(2)F(3) group are trans to one another (1.813 Å). The OsO(2)F(3)(+) cation was characterized by (19)F NMR and by Raman spectroscopy in neat SbF(5) solution but was not isolable in the solid state. The NMR and Raman spectroscopic findings are consistent with a trigonal bipyramidal cation in which the oxygen atoms and a fluorine atom occupy the equatorial plane and two fluorine atoms are in axial positions. Density functional theory calculations show that the crystallographic structure of F(cis-OsO(2)F(3))(2)(+) is the energy-minimized structure and the energy-minimized structures of the OsO(2)F(3)(+) cation and ReO(2)F(3) are trigonal bipyramidal having C(2)(v)() point symmetry. Attempts to prepare the OsOF(5)(+) cation by oxidative fluorination of cis-Os

New small molecules targeting apoptosis and cell viability in osteosarcoma.

Directory of Open Access Journals (Sweden)

Doris Maugg

Full Text Available Despite the option of multimodal therapy in the treatment strategies of osteosarcoma (OS, the most common primary malignant bone tumor, the standard therapy has not changed over the last decades and still involves multidrug chemotherapy and radical surgery. Although successfully applied in many patients a large number of patients eventually develop recurrent or metastatic disease in which current therapeutic regimens often lack efficacy. Thus, new therapeutic strategies are urgently needed. In this study, we performed a phenotypic high-throughput screening campaign using a 25,000 small-molecule diversity library to identify new small molecules selectively targeting osteosarcoma cells. We could identify two new small molecules that specifically reduced cell viability in OS cell lines U2OS and HOS, but affected neither hepatocellular carcinoma cell line (HepG2 nor primary human osteoblasts (hOB. In addition, the two compounds induced caspase 3 and 7 activity in the U2OS cell line. Compared to conventional drugs generally used in OS treatment such as doxorubicin, we indeed observed a greater sensitivity of OS cell viability to the newly identified compounds compared to doxorubicin and staurosporine. The p53-negative OS cell line Saos-2 almost completely lacked sensitivity to compound treatment that could indicate a role of p53 in the drug response. Taken together, our data show potential implications for designing more efficient therapies in OS.

mTORC2 activation is regulated by the urokinase receptor (uPAR) in bladder cancer.

Science.gov (United States)

Hau, Andrew M; Leivo, Mariah Z; Gilder, Andrew S; Hu, Jing-Jing; Gonias, Steven L; Hansel, Donna E

2017-01-01

Mammalian target of rapamycin complex 2 (mTORC2) has been identified as a major regulator of bladder cancer cell migration and invasion. Upstream pathways that mediate mTORC2 activation remain poorly defined. Urokinase-type plasminogen activator receptor (uPAR) is a GPI-anchored membrane protein and known activator of cell-signaling. We identified increased uPAR expression in 94% of invasive human bladder cancers and in 54-71% of non-invasive bladder cancers, depending on grade. Normal urothelium was uPAR-immunonegative. Analysis of publicly available datasets identified uPAR gene amplification or mRNA upregulation in a subset of bladder cancer patients with reduced overall survival. Using biochemical approaches, we showed that uPAR activates mTORC2 in bladder cancer cells. Highly invasive bladder cancer cell lines, including T24, J82 and UM-UC-3 cells, showed increased uPAR mRNA expression and protein levels compared with the less aggressive cell lines, UROtsa and RT4. uPAR gene-silencing significantly reduced phosphorylation of Serine-473 in Akt, an mTORC2 target. uPAR gene-silencing also reduced bladder cancer cell migration and Matrigel invasion. S473 phosphorylation was observed by immunohistochemistry in human bladder cancers only when the tumors expressed high levels of uPAR. S473 phosphorylation was not controlled by uPAR in bladder cancer cell lines that are PTEN-negative; however, this result probably did not reflect altered mTORC2 regulation. Instead, PTEN deficiency de-repressed alternative kinases that phosphorylate S473. Our results suggest that uPAR and mTORC2 are components of a single cell-signaling pathway. Targeting uPAR or mTORC2 may be beneficial in patients with bladder cancer. Copyright © 2016. Published by Elsevier Inc.

Changes in nuclear protein acetylation in u. v. -damaged human cells

Energy Technology Data Exchange (ETDEWEB)

Ramanathan, B.; Smerdon, M.J.

1986-07-01

We have investigated the levels of nuclear protein acetylation in u.v.-irradiated human fibroblasts. We measured the levels of acetylation in total acid-soluble nuclear proteins and observed two distinct differences between the irradiated and unirradiated (control) cells. Immediately after irradiation, there is a wave of protein hyperacetylation (i.e. a total acetylation level greater than that of unirradiated cells) that lasts for 2-6 h depending on the experimental conditions. This hyperacetylation phase is then followed by a hypoacetylation phase, lasting for many hours, and the total level of acetylation does not return to that of control cells until 24-72 h after u.v. damage. Both the magnitude and duration of each phase is dependent on the dose of u.v. light used. The wave of hyperacetylation is more pronounced at low u.v. doses (i.e. less than 5 J/m2), while the wave of hypoacetylation is more pronounced at higher u.v. doses (greater than or equal to 8 J/m2). Furthermore, the duration of each phase is prolonged when cells are exposed to 2 mM hydroxyurea. Examination of the acetylation levels of the individual nuclear proteins indicated that acetylation of the core histones follows the same pattern observed for the total acid-soluble protein fractions. Furthermore, these were the only major proteins in the total acid-soluble fraction observed to undergo the early, rapid hyperacetylation immediately following u.v. damage. Acetylation of histone H1 was negligible in both damaged and control cells, while three prominent non-histone proteins were acetylated only after long labeling times (greater than 4 h) in each case, gradually becoming hyperacetylated in the u.v.-damaged cells. These results raise the possibility that a causal relationship exists between nuclear protein acetylation and nucleotide excision repair of DNA in human cells.

Two rice plasma membrane intrinsic proteins, OsPIP2;4 and OsPIP2;7, are involved in transport and providing tolerance to boron toxicity.

Science.gov (United States)

Kumar, Kundan; Mosa, Kareem A; Chhikara, Sudesh; Musante, Craig; White, Jason C; Dhankher, Om Parkash

2014-01-01

Boron (B) toxicity is responsible for low cereal crop production in a number of regions worldwide. In this report, we characterized two rice genes, OsPIP2;4 and OsPIP2;7, for their involvement in B permeability and tolerance. Transcript analysis demonstrated that the expression of OsPIP2;4 and OsPIP2;7 were downregulated in shoots and strongly upregulated in rice roots by high B treatment. Expression of both OsPIP2;4 and OsPIP2;7 in yeast HD9 strain lacking Fps1, ACR3, and Ycf1 resulted in an increased B sensitivity. Furthermore, yeast HD9 strain expressing OsPIP2;4 and OsPIP2;7 accumulated significantly higher B as compared to empty vector control, which suggests their involvement in B transport. Overexpression of OsPIP2;4 and OsPIP2;7 in Arabidopsis imparted higher tolerance under B toxicity. Arabidopsis lines overexpressing OsPIP2;4 and OsPIP2;7 showed significantly higher biomass production and greater root length, however there was no difference in B accumulation in long term uptake assay. Short-term uptake assay using tracer B (¹⁰B) in shoots and roots demonstrated increased ¹⁰B accumulation in Arabidopsis lines expressing OsPIP2;4 and OsPIP2;7, compare to wild type control plants. Efflux assay of B in the roots showed that ¹⁰B was effluxed from the Arabidopsis transgenic plants overexpressing OsPIP2;4 or OsPIP2;7 during the initial 1-h of assay. These data indicate that OsPIP2;4 and OsPIP2;7 are involved in mediating B transport in rice and provide tolerance via efflux of excess B from roots and shoot tissues. These genes will be highly useful in developing B tolerant crops for enhanced yield in the areas affected by high B toxicity.

Comparative Study of Electronic Structure and Magnetic Properties of Osmate Double Perovskites: Ca2FeOsO6 versus Ca2Co(Ni)OsO6

Science.gov (United States)

Samanta, Kartik; Saha-Dasgupta, Tanusri

2018-04-01

Employing density functional theory, we study the trend in the electronic and magnetic properties of 3d-5d double perovskites, upon varying the 3d element for a fixed choice of 5d element, namely Ca2BOsO6 (B = Fe/Co/Ni). While all three compounds are reported to be ferrimagnets, the magnetic transition temperature of Ca2FeOsO6 is reported to be 2-2.4 times larger than that of Ca2CoOsO6 or Ca2NiOsO6. Our first-principles study provides microscopic insight into this trend. This trend is found to be caused by the downward shift in the position of d level energies of the B site element with respect to that of the Os t2g level upon moving across the 3d series from Fe to Co and Ni. This in turn changes the nominal valence of the Os ion from 5+ in Ca2FeOsO6 to 6+ in Ca2CoOsO6 and Ca2NiOsO6, resulting in differing superexchange paths between Ca2FeOsO6 and Ca2Co(Ni)OsO6, and additionally enabling the hybridization-mechanism-driven magnetism in Ca2FeOsO6. These together significantly enhance the magnetic transition temperature in Ca2FeOsO6 compared with that in Ca2Co(Ni)OsO6.

Targeted Lymphoma Cell Death by Novel Signal Transduction Modifications

Science.gov (United States)

2011-07-01

60 80 100 120 Jurkat R am os R aji M C 116 D O H H 2 W S U -W M W S U -C LL K arpas 519 C ell Lines A s C o n tr o l ( % ) Figure 6...Lym phom a cell Lines 0 20 40 60 80 100 120 Jurkat R am os R aji M C 116 D O H H 2 W S U -W M W S U -C LL K arpas 519 C ell Lines A s C o n tr o l...plemented with 10% FCS and incubated with AET- activated sheep red blood cells (SRBC) for 1 h. B-cells were collected at the interface after centrifugation

Chemical and Electrochemical Asymmetric Dihydroxylation of Olefins in I(2)-K(2)CO(3)-K(2)OsO(2)(OH)(4) and I(2)-K(3)PO(4)/K(2)HPO(4)-K(2)OsO(2)(OH)(4) Systems with Sharpless' Ligand.

Science.gov (United States)

Torii, Sigeru; Liu, Ping; Bhuvaneswari, Narayanaswamy; Amatore, Christian; Jutand, Anny

1996-05-03

Iodine-assisted chemical and electrochemical asymmetric dihydroxylation of various olefins in I(2)-K(2)CO(3)-K(2)OsO(2)(OH)(4) and I(2)-K(3)PO(4)/K(2)HPO(4)-K(2)OsO(2)(OH)(4) systems with Sharpless' ligand provided the optically active glycols in excellent isolated yields and high enantiomeric excesses. Iodine (I(2)) was used stoichiometrically for the chemical dihydroxylation, and good results were obtained with nonconjugated olefins in contrast to the case of potassium ferricyanide as a co-oxidant. The potentiality of I(2) as a co-oxidant under stoichiometric conditions has been proven to be effective as an oxidizing mediator in electrolysis systems. Iodine-assisted asymmetric electro-dihydroxylation of olefins in either a t-BuOH/H(2)O(1/1)-K(2)CO(3)/(DHQD)(2)PHAL-(Pt) or t-BuOH/H(2)O(1/1)-K(3)PO(4)/K(2)HPO(4)/(DHQD)(2)PHAL-(Pt) system in the presence of potassium osmate in an undivided cell was investigated in detail. Irrespective of the substitution pattern, all the olefins afforded the diols in high yields and excellent enantiomeric excesses. A plausible mechanism is discussed on the basis of cyclic voltammograms as well as experimental observations.

OsDOG, a gibberellin-induced A20/AN1 zinc-finger protein, negatively regulates gibberellin-mediated cell elongation in rice.

Science.gov (United States)

Liu, Yaju; Xu, Yunyuan; Xiao, Jun; Ma, Qibin; Li, Dan; Xue, Zhen; Chong, Kang

2011-07-01

The A20/AN1 zinc-finger proteins (ZFPs) play pivotal roles in animal immune responses and plant stress responses. From previous gibberellin (GA) microarray data and A20/AN1 ZFP family member association, we chose Oryza sativa dwarf rice with overexpression of gibberellin-induced gene (OsDOG) to examine its function in the GA pathway. OsDOG was induced by gibberellic acid (GA(3)) and repressed by the GA-synthesis inhibitor paclobutrazol. Different transgenic lines with constitutive expression of OsDOG showed dwarf phenotypes due to deficiency of cell elongation. Additional GA(1) and real-time PCR quantitative assay analyses confirmed that the decrease of GA(1) in the overexpression lines resulted from reduced expression of GA3ox2 and enhanced expression of GA2ox1 and GA2ox3. Adding exogenous GA rescued the constitutive expression phenotypes of the transgenic lines. OsDOG has a novel function in regulating GA homeostasis and in negative maintenance of plant cell elongation in rice. Copyright © 2011 Elsevier GmbH. All rights reserved.

Impact of uranium (U) on the cellular glutathione pool and resultant consequences for the redox status of U.

Science.gov (United States)

Viehweger, Katrin; Geipel, Gerhard; Bernhard, Gert

2011-12-01

Uranium (U) as a redox-active heavy metal can cause various redox imbalances in plant cells. Measurements of the cellular glutathione/glutathione disulfide (GSH/GSSG) by HPLC after cellular U contact revealed an interference with this essential redox couple. The GSH content remained unaffected by 10 μM U whereas the GSSG level immediately increased. In contrast, higher U concentrations (50 μM) drastically raised both forms. Using the Nernst equation, it was possible to calculate the half-cell reduction potential of 2GSH/GSSG. In case of lower U contents the cellular redox environment shifted towards more oxidizing conditions whereas the opposite effect was obtained by higher U contents. This indicates that U contact causes a consumption of reduced redox equivalents. Artificial depletion of GSH by chlorodinitrobenzene and measuring the cellular reducing capacity by tetrazolium salt reduction underlined the strong requirement of reduced redox equivalents. An additional element of cellular U detoxification mechanisms is the complex formation between the heavy metal and carboxylic functionalities of GSH. Because two GSH molecules catalyze electron transfers each with one electron forming a dimer (GSSG) two UO(2) (2+) are reduced to each UO(2) (+) by unbound redox sensitive sulfhydryl moieties. UO(2) (+) subsequently disproportionates to UO(2) (2+) and U(4+). This explains that in vitro experiments revealed a reduction to U(IV) of only around 33% of initial U(VI). Cellular U(IV) was transiently detected with the highest level after 2 h of U contact. Hence, it can be proposed that these reducing processes are an important element of defense reactions induced by this heavy metal.

PTEN-induction in U251 glioma cells decreases the expression of insulin-like growth factor binding protein-2

International Nuclear Information System (INIS)

Levitt, Randy J.; Georgescu, Maria-Magdalena; Pollak, Michael

2005-01-01

PTEN is a tumor suppressor gene whose loss of function is observed in ∼40-50% of human cancers. Although insulin-like growth factor binding protein-2 (IGFBP-2) was classically described as a growth inhibitor, multiple recent reports have shown an association of overexpression and/or high serum levels of IGFBP-2 with poor prognosis of several malignancies, including gliomas. Using an inducible PTEN expression system in the PTEN-null glioma cell line U251, we demonstrate that PTEN-induction is associated with reduced proliferation, increased apoptosis, and a substantial reduction of the high levels of IGFBP-2 expression. The PTEN-induced decrease in IGFBP-2 expression could be mimicked with the PI3-kinase inhibitor LY294002, indicating that the lipid phosphatase activity of PTEN is responsible for the observed effect. However, the rapamycin analog CCI-779 did not affect IGFBP-2 expression, suggesting that the PTEN-induced decrease in IGFBP-2 expression is not attributable to decreased mTOR signalling. Recombinant human IGFBP-2 was unable to rescue U251-PTEN cells from the antiproliferative effects of PTEN, and IGFBP-2 siRNA did not affect the IGF-dependent or -independent growth of this cell line. These results suggest that the clinical data linking IGFBP-2 expression to poor prognosis may arise, at least in part, because high levels of IGFBP-2 expression correlate with loss of function of PTEN, which is well known to lead to aggressive behavior of gliomas. Our results motivate translational research regarding the relationship between IGFBP-2 expression and loss of function of PTEN

Electronic, structural and magnetic studies of niobium borides of group 8 transition metals, Nb{sub 2}MB{sub 2} (M=Fe, Ru, Os) from first principles calculations

Energy Technology Data Exchange (ETDEWEB)

Touzani, Rachid St.; Fokwa, Boniface P.T., E-mail: Boniface.Fokwa@ac.rwth-aachen.de

2014-03-15

The Nb{sub 2}FeB{sub 2} phase (U{sub 3}Si{sub 2}-type, space group P4/mbm, no. 127) is known for almost 50 years, but until now its magnetic properties have not been investigated. While the synthesis of Nb{sub 2}OsB{sub 2} (space group P4/mnc, no. 128, a twofold superstructure of U{sub 3}Si{sub 2}-type) with distorted Nb-layers and Os{sub 2}-dumbbells was recently achieved, “Nb{sub 2}RuB{sub 2}” is still not synthesized and its crystal structure is yet to be revealed. Our first principles density functional theory (DFT) calculations have confirmed not only the experimental structures of Nb{sub 2}FeB{sub 2} and Nb{sub 2}OsB{sub 2}, but also predict “Nb{sub 2}RuB{sub 2}” to crystalize with the Nb{sub 2}OsB{sub 2} structure type. According to chemical bonding analysis, the homoatomic B–B interactions are optimized and very strong, but relatively strong heteroatomic M–B, B–Nb and M–Nb bonds (M=Fe, Ru, Os) are also found. These interactions, which together build a three-dimensional network, are mainly responsible for the structural stability of these ternary borides. The density-of-states at the Fermi level predicts metallic behavior, as expected, from metal-rich borides. Analysis of possible magnetic structures concluded preferred antiferromagnetic ordering for Nb{sub 2}FeB{sub 2}, originating from ferromagnetic interactions within iron chains and antiferromagnetic exchange interactions between them. -- Graphical abstract: Nb{sub 2}FeB{sub 2} (U{sub 3}Si{sub 2} structure type, space group P4/mbm, no. 127) is predicted to order antiferromagnetically, due to the presence of iron chains which show ferromagnetic interactions in the chains and antiferromagnetic interactions between them. “Nb{sub 2}RuB{sub 2}” is predicted to crystallize with the recently discovered Nb{sub 2}OsB{sub 2} twofold superstructure (space group P4/mnc, no. 128) of U{sub 3}Si{sub 2} structure type. The building of ruthenium dumbbells instead of chains along [001] is found to be

The Transient Receptor Potential Melastatin 7 Channel Regulates Pancreatic Cancer Cell Invasion through the Hsp90α/uPA/MMP2 pathway

Directory of Open Access Journals (Sweden)

Pierre Rybarczyk

2017-04-01

Full Text Available Pancreatic ductal adenocarcinoma (PDAC is an aggressive malignancy with a very poor prognosis. There is an urgent need to better understand the molecular mechanisms that regulate PDAC cell aggressiveness. The transient receptor potential melastatin 7 (TRPM7 is a nonselective cationic channel that mainly conducts Ca2+ and Mg2+. TRPM7 is overexpressed in numerous malignancies including PDAC. In the present study, we used the PANC-1 and MIA PaCa-2 cell lines to specifically assess the role of TRPM7 in cell invasion and matrix metalloproteinase secretion. We show that TRPM7 regulates Mg2+ homeostasis and constitutive cation entry in both PDAC cell lines. Moreover, cell invasion is strongly reduced by TRPM7 silencing without affecting the cell viability. Conditioned media were further studied, by gel zymography, to detect matrix metalloproteinase (MMP secretion in PDAC cells. Our results show that MMP-2, urokinase plasminogen activator (uPA, and heat-shock protein 90α (Hsp90α secretions are significantly decreased in TRPM7-deficient PDAC cells. Moreover, TRPM7 expression in human PDAC lymph node metastasis is correlated to the channel expression in primary tumor. Taken together, our results show that TRPM7 is involved in PDAC cell invasion through regulation of Hsp90α/uPA/MMP-2 proteolytic axis, confirming that this channel could be a promising biomarker and possibly a target for PDAC metastasis therapy.

[Ag(NH3)2]Ag(OsO3N)2: a new nitridoosmate(VIII)

International Nuclear Information System (INIS)

Wickleder, M.S.; Pley, Martin

2004-01-01

Dark brown single crystals of [Ag(NH 3 ) 2 ]Ag(OsO 3 N) 2 were obtained from the reaction of Ag 2 CO 3 , OsO 4 , and NH 3 in aqueous solution. The crystal structure was solved in the monoclinic space group C2/m, with the following unit-cell dimensions: a=1962.5(3), b=633.1(1), c=812.6(1) pm, β=96.71(1) deg. The final reliability factor was R=0.0256 for 1034 reflections with I>2σ(I). Linear [Ag(NH 3 ) 2 ] + ions are present oriented perpendicular to the [010] direction, leading to short Ag + -Ag + distances of 316 pm. A second type of Ag + ions in the crystal structure present coordination number '6+1' and are surrounded by oxygen and nitrogen atoms of the nitridoosmate groups. Within the first of the two crystallographically distinguishable anions one can clearly differentiate between oxygen and nitrogen atoms while the second one exhibits a N/O disorder over two positions. The infrared spectrum of [Ag(NH 3 ) 2 ]Ag(OsO 3 N) 2 shows the typical absorptions which can be attributed to the complex anions and the NH 3 ligands

OsRAMOSA2 Shapes Panicle Architecture through Regulating Pedicel Length

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Huan Lu

2017-09-01

Full Text Available The panicle architecture of rice is an important characteristic that influences reproductive success and yield. It is largely determined by the number and length of the primary and secondary branches. The number of panicle branches is defined by the inflorescence meristem state between determinacy and indeterminacy; for example, the maize ramosa2 (ra2 mutant has more branches in its tassel through loss of spikelet determinacy. Some genes and factors influencing the number of primary and secondary branches have been studied, but little is known about the molecular mechanism underlying pedicel development, which also influences panicle architecture. We report here that rice OsRAMOSA2 (OsRA2 gene modifies panicle architecture through regulating pedicel length. Ectopic expression of OsRA2 resulted in a shortened pedicel while inhibition of OsRA2 through RNA interference produced elongated pedicel. In addition, OsRA2 influenced seed morphology. The OsRA2 protein localized to the nucleus and showed transcriptional activation in yeast; in accordance with its function in pedicel development, OsRA2 mRNA was enriched in the anlagen of axillary meristems, such as primary and secondary branch meristems and the spikelet meristems of young panicles. This indicates a conserved role of OsRA2 for shaping the initial steps of inflorescence architecture. Genetic analysis revealed that OsRA2 may control panicle architecture using the same pathway as that of the axillary meristem gene LAX1 (LAX PANICLE1. Moreover, OsRA2 acted downstream of RCN2 in regulating pedicel and branch lengths, but upstream of RCN2 for control of the number of secondary branches, indicating that branch number and length development in the panicle were respectively regulated using parallel pathway. Functional conservation between OsRA2 and AtLOB, and the conservation and diversification of RA2 in maize and rice are also discussed.

LncRNA TUG1 is upregulated and promotes cell proliferation in osteosarcoma

Directory of Open Access Journals (Sweden)

Yun-Bo Feng

2016-01-01

Full Text Available Objective: To examine the expression and function of long non-coding RNA taurine up-regulated 1 (TUG1 in human osteosarcoma cells. Methods: Real-time quantitive PCR was used to detect the transcription level of TUG1 in a series of osteosarcoma cell lines. Knockdown of TUG1 in U2OS cells was carried out by transient transfection of siRNAs. MTT assay was performed to access the cell growth rates. Afterwards, RNA and protein of these cells were extracted to analyze the transfection efficient as well as the expression of other molecules. Results: Compared to the normal cell line, TUG1 exhibited a significant upregulation in osteosarcoma cells. Phenotyping analysis showed the growth-promotion activity of TUG1, since knockdown of TUG1 resulted in declined proliferation. We also found that AKT phosphorylation was impaired after TUG1 was inhibited, suggesting that the AKT pathway was involved in the regulation of TUG1 in U2OS cells. Conclusion: Our data provided evidence that TUG1 was upregulated and acted as a possible oncogene via positively regulating cell proliferation in osteosarcoma cells.

Changes in nuclear protein acetylation in u.v.-damaged human cells

International Nuclear Information System (INIS)

Ramanathan, B.; Smerdon, M.J.

1986-01-01

The levels of nuclear protein acetylation in u.v.-irradiated human fibroblasts have been investigated. Initially, we measured the levels of acetylation in total acid-soluble nuclear proteins and observed two distinct differences between the irradiated and unirradiated (control) cells. Immediately after irradiation, there is a 'wave' of protein hyperacetylation that lasts for 2-6 h, followed by a hypoacetylation phase, lasting for many hours, and the total level of acetylation does not return to that of control cells until 24-72 h after u.v. damage. Both the magnitude and duration of each phase is dependent on the dose of u.v. light used. The wave of hyperacetylation is more pronounced at low u.v. doses, while the wave of hypoacetylation is more pronounced at higher u.v. doses. Furthermore, the duration of each phase is prolonged when cells are exposed to 2 mM hydroxyurea, an agent which retards the rate of excision repair at u.v.-damaged sites. Examinations of the acetylation levels of the individual nuclear proteins indicated that acetylation of the core histones follows the same pattern observed for the total acid-soluble protein fractions. Furthermore, these were the only major proteins in the total acid-soluble fraction observed to undergo the early, rapid hyperacetylation immediately following u.v. damage. These results raise the possibility that a causal relationship exists between nuclear protein acetylation and nucleotide excision repair of DNA in human cells. (author)

MMP-9, uPA and uPAR proteins expression and its prognostic significance in esophageal squamous cell carcinoma treated by radiotherapy

International Nuclear Information System (INIS)

Zhu Shuchai; Wang Yafei; Su Jingwei; Wang Yuxiang; Shen Wenbin; Li Juan

2008-01-01

Objective: To explore the the prognostic significance of MMP-9, uPA and uPAR protein expression and its relationship with clinical-pathologic factors in esophageal squamous cell carcinoma treated by radiotherapy. Methods: MMP-9, uPA and uPAR protein expression was measured in 59 esophageal carcinomas and 41 peri-carcinoma tissues with immunohistochemistry. The relationship between the protein expression and the clinical-pathological parameters was analyzed, and the prognostic factors in esophageal squamous cell carcinoma treated by radiotherapy alone was evaluated. Results: The rates of positive expression of MMP-9, uPA and uPAR were 85%, 76% and 78% in esophageal carcinoma and 39%, 49% and 44% in peri-carcinoma tissues (χ 2 =22.54, 8.04 and 12.18; P=0.000,0.005 and 0.000). The rates of positive expression of MMP-9 was 79% and 100% when the depth of tumor invasion was ≤2 cm and >2 cm(P= 0.048), respectively. The expression of uPA was significantly correlated with the status of fat interspace between the esophageal lesion and the vertebra in CT scanning image. When the fat interspace existed and disappeared, the rates of strong positive expression was 44% and 70%, respectively (χ 2 =4.21, P=0.040). The positive expression rate of uPA was significantly correlated with distant metastasis, which was 100% in patients with distant metastasis and 68.89% in those without distant metastasis(χ 2 =4.12, P=0.042). The positive expression rate of MMP-9, uPA and uPAR did not affect the prognosis and the short-term result of esophageal carcinoma treated by radiotherapy alone. Conclusions: The protein expression of MMP-9, uPA and uPAR may correlate with local infiltration and distant metastasis in esophageal squamous cell carcinoma. Protein expression may not influence the prognosis of esophageal carcinoma treated by radio therapy, though long time followed-up is still needed. (authors)

Urokinase-type plasminogen activator (uPA) stimulates triglyceride synthesis in Huh7 hepatoma cells via p38-dependent upregulation of DGAT2.

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Paland, Nicole; Gamliel-Lazarovich, Aviva; Coleman, Raymond; Fuhrman, Bianca

2014-11-01

The liver is the central organ of fatty acid and triglyceride metabolism. Oxidation and synthesis of fatty acids and triglycerides is under the control of peroxisome-proliferator-activated receptors (PPAR) α. Impairment of these receptors' function contributes to the accumulation of triglycerides in the liver resulting in non-alcoholic fatty liver disease. Urokinase-type plasminogen activator (uPA) was shown to regulate gene expression in the liver involving PPARγ transcriptional activity. In this study we questioned whether uPA modulates triglyceride metabolism in the liver, and investigated the mechanisms involved in the observed processes. Huh7 hepatoma cells were incubated with increasing concentrations of uPA for 24 h uPA dose-dependently increased the cellular triglyceride mass, and this effect resulted from increased de novo triglyceride synthesis mediated by the enzyme diglyceride acyltransferase 2 (DGAT2). Also, the amount of free fatty acids was highly up regulated by uPA through activation of the transcription factor SREBP-1. Chemical activation of PPARα further increased uPA-stimulated triglyceride synthesis, whereas inhibition of p38, an upstream activator of PPARα, completely abolished the stimulatory effect of uPA on both triglyceride synthesis and DGAT2 upregulation. The effect of uPA on triglyceride synthesis in Huh7 cells was mediated via binding to its receptor, the uPAR. In vivo studies in uPAR(-/-) mice demonstrated that no lipid droplets were observed in their livers compared to C57BL/6 mice and the triglyceride levels were significantly lower. This study presents a new biological function of the uPA/uPAR system in the metabolism of triglycerides and might present a new target for an early therapeutic intervention for NAFLD. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

LncRNA TUG1 is upregulated and promotes cell proliferation in osteosarcoma.

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Yun-Bo, Feng; Xiao-Po, Liu; Xiao-Li, Li; Guo-Long, Cao; Pei, Zhang; Fa-Ming, Tian

2016-01-01

To examine the expression and function of long non-coding RNA taurine up-regulated 1 ( TUG1 ) in human osteosarcoma cells. Real-time quantitive PCR was used to detect the transcription level of TUG1 in a series of osteosarcoma cell lines. Knockdown of TUG1 in U2OS cells was carried out by transient transfection of siRNAs. MTT assay was performed to access the cell growth rates. Afterwards, RNA and protein of these cells were extracted to analyze the transfection efficient as well as the expression of other molecules. Compared to the normal cell line, TUG1 exhibited a significant upregulation in osteosarcoma cells. Phenotyping analysis showed the growth-promotion activity of TUG1 , since knockdown of TUG1 resulted in declined proliferation. We also found that AKT phosphorylation was impaired after TUG1 was inhibited, suggesting that the AKT pathway was involved in the regulation of TUG1 in U2OS cells. Our data provided evidence that TUG1 was upregulated and acted as a possible oncogene via positively regulating cell proliferation in osteosarcoma cells.

Saponin 6 derived from Anemone taipaiensis induces U87 human malignant glioblastoma cell apoptosis via regulation of Fas and Bcl‑2 family proteins.

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Ji, Chen-Chen; Tang, Hai-Feng; Hu, Yi-Yang; Zhang, Yun; Zheng, Min-Hua; Qin, Hong-Yan; Li, San-Zhong; Wang, Xiao-Yang; Fei, Zhou; Cheng, Guang

2016-07-01

Glioblastoma multiforme (GBM) is the most common and aggressive type of brain tumor, and is associated with a poor prognosis. Saponin 6, derived from Anemone taipaiensis, exerts potent cytotoxic effects against the human hepatocellular carcinoma HepG2 cell line and the human promyelocytic leukemia HL‑60 cell line; however, the effects of saponin 6 on glioblastoma remain unknown. The present study aimed to evaluate the effects of saponin 6 on human U87 malignant glioblastoma (U87 MG) cells. The current study revealed that saponin 6 induced U87 MG cell death in a dose‑ and time‑dependent manner, with a half maximal inhibitory concentration (IC50) value of 2.83 µM after treatment for 48 h. However, saponin 6 was needed to be used at a lesser potency in HT‑22 cells, with an IC50 value of 6.24 µM. Cell apoptosis was assessed by flow cytometry using Annexin V‑fluorescein isothiocyanate/propidium iodide double staining. DNA fragmentation and alterations in nuclear morphology were examined by terminal deoxynucleotidyl transferase‑mediated dUTP nick end labeling and transmission electron microscopy, respectively. The present study demonstrated that treatment with saponin 6 induced cell apoptosis in U87 MG cells, and resulted in DNA fragmentation and nuclear morphological alterations typical of apoptosis. In addition, flow cytometric analysis revealed that saponin 6 was able to induce cell cycle arrest. The present study also demonstrated that saponin 6‑induced apoptosis of U87 MG cells was attributed to increases in the protein expression levels of Fas, Fas ligand, and cleaved caspase‑3, ‑8 and ‑9, and decreases in the levels of B‑cell lymphoma 2. The current study indicated that saponin 6 may exhibit selective cytotoxicity toward U87 MG cells by activating apoptosis via the extrinsic and intrinsic pathways. Therefore, saponin 6 derived from A. taipaiensis may possess therapeutic potential for the treatment of GBM.

Targeting Werner syndrome protein sensitizes U-2 OS osteosarcoma cells to selenium-induced DNA damage response and necrotic death

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Cheng, Wen-Hsing; Wu, Ryan T Y; Wu, Min

2012-01-01

to MSeA-induced necrotic death. Co-treatment with the ataxia-telangiectasia mutated (ATM) kinase inhibitor KU55933 desensitized the control shRNA cells, but not WRN shRNA cells, to MSeA treatment. WRN did not affect MSeA-induced ATM phosphorylation on Ser-1981 or H2A.X phosphorylation on Ser-139...

miR-367 regulation of DOC-2/DAB2 interactive protein promotes proliferation, migration and invasion of osteosarcoma cells.

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Cai, Wei; Jiang, Haitao; Yu, Yifan; Xu, Yong; Zuo, Wenshan; Wang, Shouguo; Su, Zhen

2017-11-01

Recently, miR-367 is reported to exert either oncogenic or tumor suppressive effects in human malignancies. Recent study reports that miR-367 is up-regulated in OS tissues and cell lines, and abrogates adriamycin-induced apoptosis. The clinical significance of miR-367 and its function in OS need further investigation. In our study, miR-367 expression in OS was markedly elevated compared with corresponding non-tumor tissues. High miR-367 expression was associated with malignant clinical features and poor prognosis of OS patients. In accordance, the levels of miR-367 were dramatically up-regulated in OS cells. Loss of miR-367 expression in Saos-2 cells obviously inhibited the proliferation, migration and invasion of cancer cells in vitro. Meanwhile, miR-367 restoration promoted these malignant behaviors of MG-63 cells. Mechanistically, miR-367 negatively regulated DOC-2/DAB2 interactive protein (DAB2IP) abundance in OS cells. Hereby, DAB2IP was recognized as a direct target gene of miR-367 in OS. DAB2IP mRNA level was down-regulated and inversely correlated with miR-367 expression in OS specimens. DAB2IP overexpression prohibited proliferation, migration and invasion in Saos-2 cells, while DAB2IP knockdown showed promoting effects on proliferation, migration and invasion of MG-63 cells. Furthermore, the role of miR-367 might be mediated by DAB2IP-regulated phosphorylation of ERK and AKT in OS cells. To conclude, miR-367 may function as a biomarker for prediction of prognosis and a target for OS therapy. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Rice Stomatal Closure Requires Guard Cell Plasma Membrane ATP-Binding Cassette Transporter RCN1/OsABCG5.

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Matsuda, Shuichi; Takano, Sho; Sato, Moeko; Furukawa, Kaoru; Nagasawa, Hidetaka; Yoshikawa, Shoko; Kasuga, Jun; Tokuji, Yoshihiko; Yazaki, Kazufumi; Nakazono, Mikio; Takamure, Itsuro; Kato, Kiyoaki

2016-03-07

Water stress is one of the major environmental stresses that affect agricultural production worldwide. Water loss from plants occurs primarily through stomatal pores. Here, we report that an Oryza sativa half-size ATP-binding cassette (ABC) subfamily G protein, RCN1/OsABCG5, is involved in stomatal closure mediated by phytohormone abscisic acid (ABA) accumulation in guard cells. We found that the GFP-RCN1/OsABCG5-fusion protein was localized at the plasma membrane in guard cells. The percentage of guard cell pairs containing both ABA and GFP-RCN1/OsABCG5 increased after exogenous ABA treatment, whereas they were co-localized in guard cell pairs regardless of whether exogenous ABA was applied. ABA application resulted in a smaller increase in the percentage of guard cell pairs containing ABA in rcn1 mutant (A684P) and RCN1-RNAi than in wild-type plants. Furthermore, polyethylene glycol (drought stress)-inducible ABA accumulation in guard cells did not occur in rcn1 mutants. Stomata closure mediated by exogenous ABA application was strongly reduced in rcn1 mutants. Finally, rcn1 mutant plants had more rapid water loss from detached leaves than the wild-type plants. These results indicate that in response to drought stress, RCN1/OsABCG5 is involved in accumulation of ABA in guard cells, which is indispensable for stomatal closure. Copyright © 2016 The Author. Published by Elsevier Inc. All rights reserved.

Genetic transformation and analysis of rice OsAPx2 gene in Medicago sativa.

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Qingjie Guan

Full Text Available The OsAPx2 gene from rice was cloned to produce PBI121::OsAPx2 dual-expression plants, of which expression level would be increasing under stressful conditions. The enzyme ascorbate peroxidase (APX in the leaves and roots of the plants increased with increasing exposure time to different sodium chloride (NaCl and hydrogen peroxide (H(2O(2concentrations, as indicated by protein gel blot analysis. The increased enzyme yield improved the ability of the plants to resist the stress treatments. The OsAPx2 gene was localized in the cytoplasm of epidermal onion cells as indicated by the instantaneous expression of green fluorescence. An 80% regeneration rate was observed in Medicago sativa L. plants transformed with the OsAPx2 gene using Agrobacterium tumefaciens, as indicated by specific primer PCR. The OsAPx2 gene was expressed at the mRNA level and the individual M. sativa (T#1,T#2,T#5 were obtained through assaying the generation of positive T2 using RNA gel blot analysis. When the seeds of the wild type (WT and the T2 (T#1,T#5 were incubated in culture containing MS with NaCl for 7 days, the results as shown of following: the root length of transgenic plant was longer than WT plants, the H(2O(2 content in roots of WT was more than of transgenic plants, the APX activity under stresses increased by 2.89 times compared with the WT, the malondialdehyde (MDA content of the WT was higher than the transgenic plants, the leaves of the WT turned yellow, but those of the transgenic plants remained green and remained healthy. The chlorophyll content in the WT leaves was less than in the transgenic plants, after soaking in solutions of H(2O(2, sodium sulfite (Na(2SO(3, and sodium bicarbonate (NaHCO(3. Therefore, the OsAPx2 gene overexpression in transgenic M. sativa improves the removal of H(2O(2 and the salt-resistance compared with WT plants. A novel strain of M. sativa carrying a salt-resistance gene was obtained.

187Os/188Os of boninites from the Izu-Bonin-Mariana forearc, IODP Exp 352

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Niles, D. E.; Nelson, W. R.; Reagan, M. K.; Pearce, J. A.; Godard, M.; Shervais, J. W.

2016-12-01

The Izu-Bonin-Mariana (IBM) subduction zone is an ideal laboratory in which to study the evolution of a subduction zone from its initiation to the development of modern-day arc volcanism. Boninite lavas were produced in the IBM forearc region during the early stages of subduction and are thought to have been generated by flux melting the previously depleted mantle wedge. Mariana forearc mantle peridotites record unradiogenic 187Os/188Os signatures (0.1193-0.1273) supporting the existence of variably depleted mantle in this region (Parkinson et al., 1998). In order to understand the connection between the regional mantle, slab-derived fluids, and the generation of boninites, Re-Os isotopic data were measured on subset of boninite-series lavas obtained during IODP Expedition 352. Preliminary age-corrected (48 Ma) 187Os/188Os isotopic data for boninite-series lavas (sites U1439C and U1442A) are unradiogenic to modestly radiogenic (0.1254-0.1390) compared to primitive mantle (0.1296), consistent with Os isotopic data from boninite sands from the Bonin Islands (0.1279-0.1382; Suzuki et al., 2011). The least radiogenic boninites have 187Os/188Os (< 0.1296) values consistent with average MORB mantle recorded globally by abyssal peridotites (0.1238 ± 0.0042; Rudnick & Walker, 2009). However, boninite lavas were not derived from the most refractory ancient mantle recorded by Mariana peridotites. Unradiogenic boninites generally have higher Os abundances (0.043-0.567 ppb), whereas more radiogenic boninites have low Os abundances (0.015-0.036). Due to their low Os abundances, the moderately radiogenic isotopic signatures may be the result of interaction with highly radiogenic seawater or incorporation of radiogenic sediment (e.g. Suzuki et al. 2011). However, the radiogenic values could also be the result of fluid flux from the subducting Pacific plate.

ALG-2 knockdown in HeLa cells results in G2/M cell cycle phase accumulation and cell death

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Høj, Berit Rahbek; la Cour, Peter Jonas Marstrand; Mollerup, Jens

2009-01-01

downregulation induces accumulation of HeLa cells in the G2/M cell cycle phase and increases the amount of early apoptotic and dead cells. Caspase inhibition by the pan-caspase inhibitor zVAD-fmk attenuated the increase in the amount of dead cells following ALG-2 downregulation. Thus, our results indicate...... that ALG-2 has an anti-apoptotic function in HeLa cells by facilitating the passage through checkpoints in the G2/M cell cycle phase.......ALG-2 (apoptosis-linked gene-2 encoded protein) has been shown to be upregulated in a variety of human tumors questioning its previously assumed pro-apoptotic function. The aim of the present study was to obtain insights into the role of ALG-2 in human cancer cells. We show that ALG-2...

Activation of PERK signaling through fluoride-mediated endoplasmic reticulum stress in OS732 cells

International Nuclear Information System (INIS)

Xu, Hui; Zhou, Yu-lai; Zhang, Xiu-yun; Lu, Peng; Li, Guang-sheng

2010-01-01

Our proteomical analysis of osteoblasts exposed to fluoride revealed a distinctive upregulation of proteins in osteoblast. These upregulated proteins play key roles in the protein folding. The PRK-like ER kinase (PERK) signaling, one branch of unfolded protein response (UPR) to combat ER stress, is a transcription factor needed for osteoblast proliferation and differentiation. The mechanism of skeletal fluorosis by which fluoride regulates osteoblast is not fully defined. Here we studied the effect of fluoride on PERK signaling genes and x-box binding protein 1 (xbp-1) in OS7232 cells (human osteoblast-like cell line). Meantime, genes associated with bone turnover were examined in this study. We found that early and continuous fluoride exposure increased the binding immunoglobulin protein (BiP) expression and activated the PERK signaling pathway, resulting in activation of transcription factor 4 (ATF4) and nuclear factor erythroid 2-related factor 2 (Nrf2). The altered expression of cbfa1, osteoprotegerin (OPG)/nuclear factor kappa B ligand (RANKL) were viewed in this study. These results showed fluoride impelled a distinctive ER stress response in OS732 cells, primarily by activating PERK and PERK-dependent signaling. Little effects were viewed for activating xbp-1, a common target of the other two canonical sensors of ER stress, ATF6 and IRE1. In this study the altered expression of bone turnover genes were consistent with activation of ER stress and PERK signaling. This study proved that PERK signaling play major roles in action of fluoride on osteoblast, and suggested that bone response in skeletal fluorosis may be due in part to PERK signaling pathway.

A Potential Bone-Targeting Hypotoxic Platinum(II) Complex with an Unusual Cytostatic Mechanism toward Osteosarcoma Cells.

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Zhang, Zhenqin; Zhu, Zhenzhu; Luo, Cheng; Zhu, Chengcheng; Zhang, Changli; Guo, Zijian; Wang, Xiaoyong

2018-03-19

Osteosarcoma (OS) is the most common primary pediatric bone tumor lethal to children and adolescents. Chemotherapeutic agents such as cisplatin are not effective for OS because of their poor accessibility to this cancer and severe systemic toxicity. In this study, a lipophilic platinum(II) complex bearing a bisphosphonate bone-targeting moiety, cis-[PtL(NH 3 ) 2 Cl]NO 3 {BPP; L = tetraethyl [2-(pyridin-2-yl)ethane-1,1-diyl]bisphosphonate}, was prepared and characterized by NMR, electrospray ionization mass spectrometry, and single-crystal X-ray crystallography. The cytotoxicity of BPP toward OS cell lines U2OS and MG-63 was tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. BPP exhibits moderate inhibition against U2OS cells through a mechanism involving both DNA binding and a mevalonate pathway. The acute toxicity of BPP to mice is 7-fold lower than that of cisplatin. The relative low systemic toxicity may result from the steric hindrance of the ligand, which blocks BPP approaching the bases of DNA. The results suggest that incorporating bisphosphonates into a platinum complex not only enhances its bone-targeting property but also minimizes its reactivity toward DNA and thereby lowers the systematic toxicity of the complex. The diminished cytotoxicity of BPP could be compensated for by increasing the therapeutic dose with marginal harm. This strategy provides a new possibility for overcoming the ineffectiveness and systemic toxicity of platinum drugs in the treatment of OS.

A Sclerostin super-producer cell line derived from the human cell line SaOS-2: a new tool for the study of the molecular mechanisms driving Sclerostin expression.

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Pérez-Campo, Flor M; Sañudo, Carolina; Delgado-Calle, Jesús; Arozamena, Jana; Zarrabeitia, María T; Riancho, José A

2014-08-01

Sclerostin, the product of the SOST gene, is a key regulator of bone homeostasis. Sclerostin interferes with the Wnt signalling pathway and, therefore, has a negative effect on bone formation. Although the importance of sclerostin in bone homeostasis is well established, many aspects of its biology are still unknown. Due to its restricted pattern of expression, in vitro studies of SOST gene regulation are technically challenging. Furthermore, a more profound investigation of the molecular mechanism controlling sclerostin expression has been hampered by the lack of a good human in vitro model. Here, we describe two cell lines derived from the human osteosarcoma cell line SaOS-2 that produce elevated levels of sclerostin. Analysis of the super-producer cell lines showed that sclerostin levels were still reduced in response to parathyroid hormone treatment or in response to mechanical loading, indicating that these regulatory mechanisms were not affected in the presented cell lines. In addition, we did not find differences between the promoter or ECR5 sequences of our clones and the SaOS-2 parental line. However, the methylation of the proximal CpG island located at the SOST promoter was lower in the super-producer clones, in agreement with a higher level of SOST transcription. Although the underlying biological causes of the elevated levels of sclerostin production in this cell line are not yet clear, we believe that it could be an extremely useful tool to study the molecular mechanisms driving sclerostin expression in humans.

Recent results from TMX-U thermal barrier experiments

International Nuclear Information System (INIS)

Molvik, A.W.; Allen, S.; Barter, J.

1984-01-01

The Tandem Mirror Experiment-Upgrade (TMX-U) device was designed to study plasma confinement in a tandem mirror with thermal barriers. Previously the author reported improved axial confinement with high end-plug potentials, consistent with thermal barrier operation. Now, the existence of thermal barriers in TMX-U confirmed by measuring the axial potential profile. Specifically, measured the change in energy of a 5-keV deuterium neutral beam that is injected nearly parallel to the axis and is ionized between the barrier and the central cell. The authors found that the barrier potential is lower than the central cell potential, as required for a thermal barrier. The peak potential is at least 2.4 keV, as determined from the minimum energy of end loss ions. In addition, radial transport is reduced by the use of floating and electrodes that map to concentric cylinders in the central cell. Sloshing ions continue to be microstable

Comparison of the reaction of bone-derived cells to enhanced MgCl2-salt concentrations.

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Burmester, Anna; Luthringer, Bérengère; Willumeit, Regine; Feyerabend, Frank

2014-01-01

Magnesium-based implants exhibit various advantages such as biodegradability and potential for enhanced in vivo bone formation. However, the cellular mechanisms behind this possible osteoconductivity remain unclear. To determine whether high local magnesium concentrations can be osteoconductive and exclude other environmental factors that occur during the degradation of magnesium implants, magnesium salt (MgCl2) was used as a model system. Because cell lines are preferred targets in studies of non-degradable implant materials, we performed a comparative study of 3 osteosarcoma-derived cell lines (MG63, SaoS2 and U2OS) with primary human osteoblasts. The correlation among cell count, viability, cell size and several MgCl2 concentrations was used to examine the influence of magnesium on proliferation in vitro. Moreover, bone metabolism alterations during proliferation were investigated by analyzing the expression of genes involved in osteogenesis. It was observed that for all cell types, the cell count decreases at concentrations above 10 mM MgCl2. However, detailed analysis showed that MgCl2 has a relevant but very diverse influence on proliferation and bone metabolism, depending on the cell type. Only for primary cells was a clear stimulating effect observed. Therefore, reliable results demonstrating the osteoconductivity of magnesium implants can only be achieved with primary osteoblasts.

Inhibiting DNA-PKCS radiosensitizes human osteosarcoma cells

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Mamo, Tewodros; Mladek, Ann C.; Shogren, Kris L.; Gustafson, Carl; Gupta, Shiv K.; Riester, Scott M.; Maran, Avudaiappan; Galindo, Mario; Wijnen, Andre J. van; Sarkaria, Jann N.; Yaszemski, Michael J.

2017-01-01

Osteosarcoma survival rate has not improved over the past three decades, and the debilitating side effects of the surgical treatment suggest the need for alternative local control approaches. Radiotherapy is largely ineffective in osteosarcoma, indicating a potential role for radiosensitizers. Blocking DNA repair, particularly by inhibiting the catalytic subunit of DNA-dependent protein kinase (DNA-PK CS ), is an attractive option for the radiosensitization of osteosarcoma. In this study, the expression of DNA-PK CS in osteosarcoma tissue specimens and cell lines was examined. Moreover, the small molecule DNA-PK CS inhibitor, KU60648, was investigated as a radiosensitizing strategy for osteosarcoma cells in vitro. DNA-PK CS was consistently expressed in the osteosarcoma tissue specimens and cell lines studied. Additionally, KU60648 effectively sensitized two of those osteosarcoma cell lines (143B cells by 1.5-fold and U2OS cells by 2.5-fold). KU60648 co-treatment also altered cell cycle distribution and enhanced DNA damage. Cell accumulation at the G2/M transition point increased by 55% and 45%, while the percentage of cells with >20 γH2AX foci were enhanced by 59% and 107% for 143B and U2OS cells, respectively. These results indicate that the DNA-PK CS inhibitor, KU60648, is a promising radiosensitizing agent for osteosarcoma. - Highlights: • DNA-PKcs is consistently expressed in human osteosarcoma tissue and cell lines. • The DNA-PKcs inhibitor, KU60648, effectively radiosensitizes osteosarcoma cells. • Combining KU60648 with radiation increases G2/M accumulation and DNA damage.

PPADS and suramin as antagonists at cloned P2Y- and P2U-purinoceptors.

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Charlton, S J; Brown, C A; Weisman, G A; Turner, J T; Erb, L; Boarder, M R

1996-06-01

1. The effect of suramin and pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS) on the stimulation of phospholipase C in 1321N1 cells transfected with the human P2U-purinoceptor (h-P2U-1321N1 cells) or with the turkey P2Y-purinoceptor (t-P2Y-1321N1 cells) was investigated. 2-Methylthioadenosine triphosphate (2MeSATP) was used as the agonist at t-P2Y-1321N1 cells and uridine triphosphate (UTP) at h-P2U-1321N1 cells. 2. Suramin caused a parallel shift to the right of the concentration-response curves for 2MeSATP in the t-P2Y-1321N1 cells, yielding a Schild plot with a slope of 1.16 +/- 0.08 and a pA2 value of 5.77 +/- 0.11. 3. Suramin also caused a shift to the right of concentration-response curves for UTP in the h-P2U-1321N1 cells, and on Schild plots gave a slope different from unity (1.57 +/- 0.19) and an apparent pA2 value of 4.32 +/- 0.13. Suramin was therefore a less potent antagonist at the P2U-purinoceptor than the P2Y-purinoceptor. 4. In the presence of the ectonucleotidase inhibitor, ARL 67156 (6-N,N-diethyl-beta,gamma-dibromomethylene-D-ATP) there was no significant difference in the EC50 or shapes of curves with either cell type, and no difference in pA2 values for suramin. 5. PPADS caused an increase in the EC50 for 2MeSATP in the t-P2Y-1321N1 cells. The Schild plot had a slope different from unity (0.55 +/- 0.15) and an X-intercept corresponding to an apparent pA2 of 5.98 +/- 0.65. 6. PPADS up to 30 microM had no effect on the concentration-response curve for UTP with the h-P2U-1321N1 cells. 7. In conclusion, suramin and PPADS show clear differences in their action at the 2 receptor types, in each case being substantially more effective as an antagonist at the P2Y-purinoceptor than at the P2U-purinoceptor. Ectonucleotidase breakdown had little influence on the nature of the responses at the two receptor types, or in their differential sensitivity to suramin.

The amount of DNA damage needed to activate the radiation-induced G2 checkpoint varies between single cells

International Nuclear Information System (INIS)

Tkacz-Stachowska, Kinga; Lund-Andersen, Christin; Velissarou, Angeliki; Myklebust, June H.; Stokke, Trond; Syljuåsen, Randi G.

2011-01-01

Background and purpose: The radiation-induced G2 checkpoint helps facilitate DNA repair before cell division. However, recent work has revealed that human cells often escape the G2 checkpoint with unrepaired DNA breaks. The purpose was to explore whether G2 checkpoint activation occurs according to a threshold level of DNA damage. Materials and methods: G2 checkpoint activation was assayed at 75–90 min and 24–48 h after X-ray irradiation of BJ diploid fibroblasts and U2OS osteosarcoma cells. Multiparameter flow cytometry with pacific blue barcoding, and flow cytometry-based sorting of phospho-H3 positive cells to microscope slides, were used to examine the DNA damage marker γ-H2AX in individual mitotic cells that had escaped the G2 checkpoint. Results: For all radiation doses and times tested, the number of γ-H2AX foci varied between individual mitotic cells. At 75 min the median levels of γ-H2AX in mitotic cells increased with higher radiation doses. At 24–48 h, following a prolonged G2 checkpoint, cells were more resistant to checkpoint re-activation by a second dose of radiation. Conclusion: Our results suggest that different amounts of DNA damage are needed to activate the G2 checkpoint in individual cells. Such single cell variation in checkpoint activation may potentially contribute to radiation-induced genomic instability.

PKC 412 sensitizes U1810 non-small cell lung cancer cells to DNA damage

International Nuclear Information System (INIS)

Hemstroem, Therese H.; Joseph, Bertrand; Schulte, Gunnar; Lewensohn, Rolf; Zhivotovsky, Boris

2005-01-01

Non-small cell lung carcinoma (NSCLC) is characterized by resistance to drug-induced apoptosis, which might explain the survival of lung cancer cells following treatment. Recently we have shown that the broad-range kinase inhibitor staurosporine (STS) reactivates the apoptotic machinery in U1810 NSCLC cells [Joseph et al., Oncogene 21 (2002) 65]. Lately, several STS analogs that are more specific in kinase inhibition have been suggested for tumor treatment. In this study the apoptosis-inducing ability of the STS analogs PKC 412 and Ro 31-8220 used alone or in combination with DNA-damaging agents in U1810 cells was investigated. In these cells Ro 31-8220 neither induced apoptosis when used alone, nor sensitized cells to etoposide treatment. PKC 412 as a single agent induced death of a small number of U1810 cells, whereas it efficiently triggered a dose- and time-dependent apoptosis in U1285 small cell lung carcinoma cells. In both cell types PKC 412 triggered release of mitochondrial proteins followed by caspase activation. However, concomitant activation of a caspase-independent pathway was essential to kill NSCLC cells. Importantly, PKC 412 was able to sensitize etoposide- and radiation-induced death of U1810 cells. The best sensitization was achieved when PKC 412 was administered 24 h after treatments. In U1810 cells, Ro 31-8220 decreased PMA-induced ERK phosphorylation as efficiently as PKC 412, indicating that the failure of Ro 31-8220 to induce apoptosis was not due to weaker inhibition of conventional and novel PKC isoforms. However, Ro 31-8220 increased the basal level of ERK and Akt phosphorylation in both cell lines, whereas Akt phosphorylation was suppressed in the U1810 cells, which might influence apoptosis. These results suggest that PKC 412 could be a useful tool in increasing the efficiency of therapy of NSCLC

Fluoride ion donor properties of cis-OsO(2)F(4): synthesis, raman spectroscopic study, and X-ray crystal structure of [OsO(2)F(3)][Sb(2)F(11)].

Science.gov (United States)

Hughes, Michael J; Mercier, Hélène P A; Schrobilgen, Gary J

2010-01-04

The salt, [OsO(2)F(3)][Sb(2)F(11)], has been synthesized by dissolution of cis-OsO(2)F(4) in liquid SbF(5), followed by removal of excess SbF(5) at 0 degrees C to yield orange, crystalline [OsO(2)F(3)][Sb(2)F(11)]. The X-ray crystal structure (-173 degrees C) consists of an OsO(2)F(3)(+) cation fluorine bridged to an Sb(2)F(11)(-) anion. The light atoms of OsO(2)F(3)(+) and the bridging fluorine atom form a distorted octahedron around osmium in which the osmium atom is displaced from its center toward an oxygen atom and away from the trans-fluorine bridge atom. As in other transition metal dioxofluorides, the oxygen ligands are cis to one another and the fluorine bridge atom is trans to an oxygen ligand and cis to the remaining oxygen ligand. The Raman spectrum (-150 degrees C) of solid [OsO(2)F(3)][Sb(2)F(11)] was assigned on the basis of the ion pair observed in the low-temperature crystal structure. Under dynamic vacuum, [OsO(2)F(3)][Sb(2)F(11)] loses SbF(5), yielding the known [mu-F(OsO(2)F(3))(2)][Sb(2)F(11)] salt with no evidence for [OsO(2)F(3)][SbF(6)] formation. Attempts to synthesize [OsO(2)F(3)][SbF(6)] by the reaction of [OsO(2)F(3)][Sb(2)F(11)] with an equimolar amount of cis-OsO(2)F(4) or by a 1:1 stoichiometric reaction of cis-OsO(2)F(4) with SbF(5) in anhydrous HF yielded only [mu-F(OsO(2)F(3))(2)][Sb(2)F(11)]. Quantum-chemical calculations at the SVWN and B3LYP levels of theory and natural bond orbital analyses were used to calculate the gas-phase geometries, vibrational frequencies, natural population analysis charges, bond orders, and valencies of OsO(2)F(3)(+), [OsO(2)F(3)][Sb(2)F(11)], [OsO(2)F(3)][SbF(6)], and Sb(2)F(11)(-). The relative thermochemical stabilities of [OsO(2)F(3)][SbF(6)], [OsO(2)F(3)][Sb(2)F(11)], [OsO(2)F(3)][AsF(6)], [mu-F(OsO(2)F(3))(2)][SbF(6)], [mu-F(OsO(2)F(3))(2)][Sb(2)F(11)], and [mu-F(OsO(2)F(3))(2)][AsF(6)] were assessed using the appropriate Born-Haber cycles to account for the preference for [mu-F(OsO(2)F(3))(2

Crystal Growth, Structures, and Properties of the Complex Borides, LaOs ₂ Al ₂ B and La ₂ Os ₂ AlB ₂

Energy Technology Data Exchange (ETDEWEB)

Bugaris, Daniel E.; Han, Fei; Im, Jino; Chung, Duck Young; Freeman, Arthur J.; Kanatzidis, Mercouri G.

2015-08-17

Single crystals of two novel quaternary metal borides, LaOs2Al2B and La2Os2AlB2, have been grown from La/Ni eutectic fluxes. LaOs2Al2B crystallizes in tetragonal space group P4/mmm with the CeCr2Si2C-type structure, and lattice parameters a = 4.2075(6) angstrom and c = 5.634(1) angstrom. La2Os2AlB2 exhibits a new crystal structure in monoclinic space group C2/c with lattice parameters a = 16.629(3) angstrom, b = 6.048(1) angstrom, c = 10.393(2) angstrom, and beta = 113.96(3)degrees. Both structures are three-dimensional frameworks with unusual coordination (for solid-state compounds) of the boron atoms by transition metal atoms. The boron atom is square planar in LaOs2Al2B, whereas it exhibits linear and T-shaped geometries in La2Os2AlB2. Electrical resistivity measurements reveal poor metal behavior (rho(30)0 (K) similar to 900 mu Omega cm) for La2Os2AlB2, consistent with the electronic band structure calculations, which also predict a metallic character for LaOs2Al2B.

Ascorbate enhances u.v.-mutagenesis in E. coli but inhibits it in Chinese hamster cells

International Nuclear Information System (INIS)

Rossman, T.G.; Klein, C.B.; Naslund, M.

1986-01-01

Ascorbic acid (vitamin C) causes an increase in the mutation frequency of u.v.-irradiated Escherichia coli WP2. The enhancement occurs at all u.v. fluences, and is dependent upon the ascorbate concentration in the medium. A maximum effect (approx. 8- to 13-fold) is seen at 100-150 μg/ml, although some enhancement can be seen even at 10 μg/ml. The comutagenic effect of ascorbate with u.v. in E. coli is dependent upon peptone, a constituent of nutrient broth. The enhancement of u.v.-mutagenesis by ascorbate is absent in strains WP2sub(s) (uvrA) amd WP6 (polA), suggesting that ascorbate affects the repair of pyrimidine dimers. The opposite results are observed for u.v.-mutagenesis in Chinese hamster V79 cells. The presence of ascorbate (50 μg/ml) during u.v. irradiation does not enhance the u.v. effect, but rather decreases it approx. 30%. These results are discussed with regard to differences in the mechanism of u.v.-mutagenesis and DNA repair in bacterial and mammalian cells. (author)

Synergism between arsenite and proteasome inhibitor MG132 over cell death in myeloid leukaemic cells U937 and the induction of low levels of intracellular superoxide anion

International Nuclear Information System (INIS)

Lombardo, Tomás; Cavaliere, Victoria; Costantino, Susana N.; Kornblihtt, Laura; Alvarez, Elida M.; Blanco, Guillermo A.

2012-01-01

Increased oxygen species production has often been cited as a mechanism determining synergism on cell death and growth inhibition effects of arsenic-combined drugs. However the net effect of drug combination may not be easily anticipated solely from available knowledge of drug-induced death mechanisms. We evaluated the combined effect of sodium arsenite with the proteasome inhibitor MG132, and the anti-leukaemic agent CAPE, on growth-inhibition and cell death effect in acute myeloid leukaemic cells U937 and Burkitt's lymphoma-derived Raji cells, by the Chou–Talalay method. In addition we explored the association of cytotoxic effect of drugs with changes in intracellular superoxide anion (O 2 − ) levels. Our results showed that combined arsenite + MG132 produced low levels of O 2 − at 6 h and 24 h after exposure and were synergic on cell death induction in U937 cells over the whole dose range, although the combination was antagonistic on growth inhibition effect. Exposure to a constant non-cytotoxic dose of 80 μM hydrogen peroxide together with arsenite + MG132 changed synergism on cell death to antagonism at all effect levels while increasing O 2 − levels. Arsenite + hydrogen peroxide also resulted in antagonism with increased O 2 − levels in U937 cells. In Raji cells, arsenite + MG132 also produced low levels of O 2 − at 6 h and 24 h but resulted in antagonism on cell death and growth inhibition. By contrast, the combination arsenite + CAPE showed high levels of O 2 − production at 6 h and 24 h post exposure but resulted in antagonism over cell death and growth inhibition effects in U937 and Raji cells. We conclude that synergism between arsenite and MG132 in U937 cells is negatively associated to O 2 − levels at early time points after exposure. -- Highlights: ► Arsenic combined cytotoxic and anti-proliferative effects by Chou–Talalay method. ► Cytotoxic effect associated with superoxide levels as assessed by flow cytometry. ► Synergism

Metabolic impact of anti-angiogenic agents on U87 glioma cells.

Directory of Open Access Journals (Sweden)

Tanja Mesti

Full Text Available BACKGROUND: Glioma cells not only secrete high levels of vascular endothelial growth factor (VEGF but also express VEGF receptors (VEGFR, supporting the existence of an autocrine loop. The direct impact on glioma cells metabolism of drugs targeting the VEGF pathway, such as Bevacizumab (Bev or VEGFR Tyrosine Kinase Inhibitor (TKI, is poorly known. MATERIAL AND METHODS: U87 cells were treated with Bev or SU1498, a selective VEGFR2 TKI. VEGFR expression was checked with FACS flow cytometry and Quantitative Real-Time PCR. VEGF secretion into the medium was assessed with an ELISA kit. Metabolomic studies on cells were performed using High Resolution Magic Angle Spinning Spectroscopy (HR-MAS. RESULTS: U87 cells secreted VEGF and expressed low level of VEGFR2, but no detectable VEGFR1. Exposure to SU1498, but not Bev, significantly impacted cell proliferation and apoptosis. Metabolomic studies with HR MAS showed that Bev had no significant effect on cell metabolism, while SU1498 induced a marked increase in lipids and a decrease in glycerophosphocholine. Accordingly, accumulation of lipid droplets was seen in the cytoplasm of SU1498-treated U87 cells. CONCLUSION: Although both drugs target the VEGF pathway, only SU1498 showed a clear impact on cell proliferation, cell morphology and metabolism. Bevacizumab is thus less likely to modify glioma cells phenotype due to a direct therapeutic pressure on the VEGF autocrine loop. In patients treated with VEGFR TKI, monitoring lipids with magnetic resonance spectroscopic (MRS might be a valuable marker to assess drug cytotoxicity.

Systems of OsO4-RuO4 and Re2O7-OsO4

International Nuclear Information System (INIS)

Nisel'son, L.A.; Sokolova, T.D.; Orlov, A.M.; Shorikov, Yu.S.

1981-01-01

The meltability diagrams of the systems OsO 4 -RuO 4 and Re 2 O 7 -OsO 4 are studied using the visual-polythermal method. The OsO 4 -RuO 4 system forms a continuous series of solid solutions with practically rectilinear line of the liquidus. The Re 2 O 7 -OsO 4 system of the eutectic type has the eutectics degenerated from the side of OsO 4 . For the system OsO 4 (basis)-RuO 4 (admixture) the equilibrium coefficient of distribution is determined using the method of directed crystallization [ru

Methyl isobutyl ketone exposure-related increases in specific measures of α2u-globulin (α2u) nephropathy in male rats along with in vitro evidence of reversible protein binding

International Nuclear Information System (INIS)

Borghoff, S.J.; Poet, T.S.; Green, S.; Davis, J.; Hughes, B.; Mensing, T.; Sarang, S.S.; Lynch, A.M.; Hard, G.C.

2015-01-01

Chronic exposure to methyl isobutyl ketone (MIBK) resulted in an increase in the incidence of renal tubule adenomas and occurrence of renal tubule carcinomas in male, but not female Fischer 344 rats. Since a number of chemicals have been shown to cause male rat renal tumors through the α2u nephropathy-mediated mode of action, the objective of this study is to evaluate the ability of MIBK to induce measures of α2u nephropathy including renal cell proliferation in male and female F344 rats following exposure to the same inhalation concentrations used in the National Toxicology Program (NTP) cancer bioassay (0, 450, 900, or 1800 ppm). Rats were exposed 6 h/day for 1 or 4 weeks and kidneys excised approximately 18 h post exposure to evaluate hyaline droplet accumulation (HDA), α2u staining of hyaline droplets, renal cell proliferation, and to quantitate renal α2u concentration. There was an exposure-related increase in all measures of α2u nephropathy in male, but not female rat kidneys. The hyaline droplets present in male rat kidney stained positively for α2u. The changes in HDA and α2u concentration were comparable to D-limonene, an acknowledged inducer of α2u nephropathy. In a separate in vitro study using a two-compartment vial equilibration model to assess the interaction between MIBK and α2u, the dissociation constant (K d ) was estimated to be 1.27 × 10 −5 M. This K d is within the range of other chemicals known to bind to α2u and cause nephropathy. Together, the exposure-related increase in measures of α2u nephropathy, sustained increase in renal cell proliferation along with an indication of reversible binding of MIBK to α2u, support the inclusion of MIBK in the category of chemicals exerting renal effects through a protein droplet α2u nephropathy-mediated mode of action (MoA)

In vitro cytotoxicity of SiO2 or ZnO nanoparticles with different sizes and surface charges on U373MG human glioblastoma cells

Directory of Open Access Journals (Sweden)

Kim JE

2014-12-01

Full Text Available Jung-Eun Kim,1,* Hyejin Kim,1,* Seong Soo A An,2 Eun Ho Maeng,3 Meyoung-Kon Kim,4 Yoon-Jae Song1 1Department of Life Science, 2Department of Bionano Technology, Gachon University, Seongnam-Si, South Korea; 3Korea Testing and Research Institute, Seoul, South Korea; 4Department of Biochemistry and Molecular Biology, Korea University Medical School and College, Seoul, South Korea *These authors contributed equally to this work Abstract: Silicon dioxide (SiO2 and zinc oxide (ZnO nanoparticles are widely used in various applications, raising issues regarding the possible adverse effects of these metal oxide nanoparticles on human cells. In this study, we determined the cytotoxic effects of differently charged SiO2 and ZnO nanoparticles, with mean sizes of either 100 or 20 nm, on the U373MG human glioblastoma cell line. The overall cytotoxicity of ZnO nanoparticles against U373MG cells was significantly higher than that of SiO2 nanoparticles. Neither the size nor the surface charge of the ZnO nanoparticles affected their cytotoxicity against U373MG cells. The 20 nm SiO2 nanoparticles were more toxic than the 100 nm nanoparticles against U373MG cells, but the surface charge had little or no effect on their cytotoxicity. Both SiO2 and ZnO nanoparticles activated caspase-3 and induced DNA fragmentation in U373MG cells, suggesting the induction of apoptosis. Thus, SiO2 and ZnO nanoparticles appear to exert cytotoxic effects against U373MG cells, possibly via apoptosis. Keyword: apoptosis

OsNF-YC2 and OsNF-YC4 proteins inhibit flowering under long-day conditions in rice

KAUST Repository

Kim, SoonKap

2015-11-05

OsNF-YC2 and OsNF-YC4 proteins regulate the photoperiodic flowering response through the modulation of three flowering-time genes ( Ehd1, Hd3a , and RFT1 ) in rice. Plant NUCLEAR FACTOR Y (NF-Y) transcription factors control numerous developmental processes by forming heterotrimeric complexes, but little is known about their roles in flowering in rice. In this study, it is shown that some subunits of OsNF-YB and OsNF-YC interact with each other, and among them, OsNF-YC2 and OsNF-YC4 proteins regulate the photoperiodic flowering response of rice. Protein interaction studies showed that the physical interactions occurred between the three OsNF-YC proteins (OsNF-YC2, OsNF-YC4 and OsNF-YC6) and three OsNF-YB proteins (OsNF-YB8, OsNF-YB10 and OsNF-YB11). Repression and overexpression of the OsNF-YC2 and OsNF-YC4 genes revealed that they act as inhibitors of flowering only under long-day (LD) conditions. Overexpression of OsNF-YC6, however, promoted flowering only under LD conditions, suggesting it could function as a flowering promoter. These phenotypes correlated with the changes in the expression of three rice flowering-time genes [Early heading date 1 (Ehd1), Heading date 3a (Hd3a) and RICE FLOWERING LOCUS T1 (RFT1)]. The diurnal and tissue-specific expression patterns of the subsets of OsNF-YB and OsNF-YC genes were similar to those of CCT domain encoding genes such as OsCO3, Heading date 1 (Hd1) and Ghd7. We propose that OsNF-YC2 and OsNF-YC4 proteins regulate the photoperiodic flowering response by interacting directly with OsNF-YB8, OsNF-YB10 or OsNF-YB11 proteins in rice.

Structure and bonding of transition metal-boryl compounds. Theoretical study of [(PH3)2(CO)ClOs-BR2] and [(PH3)2(CO)2ClOs-BR2] (BR2 = BH2, BF2, B(OH)2, B(OCH=CHO), Bcat).

Science.gov (United States)

Giju, K T; Bickelhaupt, F M; Frenking, G

2000-10-16

Quantum chemical DFT calculations using the B3LYP functionals have been carried out for the electronically unsaturated 16 VE five-coordinate osmium boryl-complexes [(PH3)2(CO)ClOs-BR2] and the 18 VE six-coordinate complexes [(PH3)2(CO)2ClOs-BR2] with BR2 = BH2, BF2, B(OH)2, B(OHC=CHO), and Bcat (cat = catecholate O2C6H4). The bonding situation of the Os-BR2 bond was analyzed with the help of the NBO partitioning scheme. The Os-B bond dissociation energies of the 16 VE complexes are very high, and they do not change very much for the different boryl ligands. The 18 VE complexes have only slightly lower bond energies than the 16 VE species. The Os-B bond in both classes of compounds is provided by a covalent sigma-bond which is polarized toward osmium and by strong charge attraction. Os-->B pi-donation is not important for the Os-B binding interactions, except for the Os-BH2 complexes. The stability of the boryl complexes [Os]-BR2 comes mainly from BB pi-donation. The intraligand charge distribution of the BR2 group changes little when the Os-B bond is formed, except for BH2. The CO ligand in [(PH3)2(CO)2ClOs-BR2] which is trans to BR2 has a relatively weak bond to the osmium atom.

Analysis of cell kinetics after gamma ray irradiation using anti-BrdU monoclonal antibody

International Nuclear Information System (INIS)

Akagi, Kiyoshi; Tanaka, Yoshimasa

1989-01-01

The cell cycle was analyzed using anti-BrdU monoclonal antibody, and changes in cell kinetics after gamma ray irradiation as evaluated by this BrdU-PI double staining were compared with those evaluated by the DNA histogram method based on PI staining. The effect of irradiation on the cell kinetics has been studied according primarily to the number of G2 blocked cells. By the present BrdU method, rapid transition of the G1-S phase was observed within 2 hours of irradiation, and then G1 block was observed. Cells in the S phase progressed to the G2 + M cells returned to the G1 phase after 18 or more hours. These initial G1 blocked cells induced by irradiation were confirmed for the fist time by the present BrdU-PI double staining. By the conventional method based on the DNA histogram, accurate determination of S cell fraction was difficult due to overlapping of the DNA contents of G1 cells and early S cells and those of late S cells and G2 cells. On the other hand, BrdU-PI double staining allowed direct differentiation of G1, S, and G2 + M cells, especially between G1-S and S-G2 + M cells. The analysis of cell kinetics using BrdU is advantageous over the conventional autoradiographic methods in that it allowed more rapid assay with very high sensitivity. In addition, BrdU is alrady used clinically as an enhancement agent in radiation therapy for cancer. The present method is considered to be indispensable for evaluation of the percentage of S cells in the tumor tissue and analysis of cell kinetics after irradiation and chemotherapy against cancer. (author)

Protein kinase D2 regulates migration and invasion of U87MG glioblastoma cells in vitro

Energy Technology Data Exchange (ETDEWEB)

Bernhart, Eva; Damm, Sabine; Wintersperger, Andrea [Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz (Austria); DeVaney, Trevor [Institute of Biophysics, Medical University of Graz (Austria); Zimmer, Andreas [Institute of Pharmaceutical Sciences, Department of Pharmaceutical Technology, Karl-Franzens University, Graz (Austria); Raynham, Tony; Ireson, Christopher [Cancer Research Technology Ltd, London (United Kingdom); Sattler, Wolfgang, E-mail: wolfgang.sattler@medunigraz.at [Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz (Austria)

2013-08-01

Glioblastoma multiforme (GBM) is the most common malignant brain tumor, which, despite combined modality treatment, reoccurs and is invariably fatal for affected patients. Recently, a member of the serine/threonine protein kinase D (PRKD) family, PRKD2, was shown to be a potent mediator of glioblastoma growth. Here we studied the role of PRKD2 in U87MG glioblastoma cell migration and invasion in response to sphingosine-1-phosphate (S1P), an activator of PRKD2 and a GBM mitogen. Time-lapse microscopy demonstrated that random cell migration was significantly diminished in response to PRKD2 silencing. The pharmacological PRKD family inhibitor CRT0066101 decreased chemotactic migration and invasion across uncoated or matrigel-coated Transwell inserts. Silencing of PRKD2 attenuated migration and invasion of U87MG cells even more effectively. In terms of downstream signaling, CRT0066101 prevented PRKD2 autophosphorylation and inhibited p44/42 MAPK and to a smaller extent p54/46 JNK and p38 MAPK activation. PRKD2 silencing impaired activation of p44/42 MAPK and p54/46 JNK, downregulated nuclear c-Jun protein levels and decreased c-Jun{sup S73} phosphorylation without affecting the NFκB pathway. Finally, qPCR array analyses revealed that silencing of PRKD2 downregulates mRNA levels of integrin alpha-2 and -4 (ITGA2 and -4), plasminogen activator urokinase (PLAU), plasminogen activator urokinase receptor (PLAUR), and matrix metallopeptidase 1 (MMP1). Findings of the present study identify PRKD2 as a potential target to interfere with glioblastoma cell migration and invasion, two major determinants contributing to recurrence of glioblastoma after multimodality treatment. Highlights: • Sphingosine-1-phosphate induces glioma cell migration and invasion. • Part of the effects is mediated by protein kinase D2 (PRKD2) activation. • Inactivation of PRKD2 attenuates glioblastoma cell migration and invasion. • Both, RNAi and pharmacological inhibition of PRKD2 inhibits MAPK

Protein kinase D2 regulates migration and invasion of U87MG glioblastoma cells in vitro

International Nuclear Information System (INIS)

Bernhart, Eva; Damm, Sabine; Wintersperger, Andrea; DeVaney, Trevor; Zimmer, Andreas; Raynham, Tony; Ireson, Christopher; Sattler, Wolfgang

2013-01-01

Glioblastoma multiforme (GBM) is the most common malignant brain tumor, which, despite combined modality treatment, reoccurs and is invariably fatal for affected patients. Recently, a member of the serine/threonine protein kinase D (PRKD) family, PRKD2, was shown to be a potent mediator of glioblastoma growth. Here we studied the role of PRKD2 in U87MG glioblastoma cell migration and invasion in response to sphingosine-1-phosphate (S1P), an activator of PRKD2 and a GBM mitogen. Time-lapse microscopy demonstrated that random cell migration was significantly diminished in response to PRKD2 silencing. The pharmacological PRKD family inhibitor CRT0066101 decreased chemotactic migration and invasion across uncoated or matrigel-coated Transwell inserts. Silencing of PRKD2 attenuated migration and invasion of U87MG cells even more effectively. In terms of downstream signaling, CRT0066101 prevented PRKD2 autophosphorylation and inhibited p44/42 MAPK and to a smaller extent p54/46 JNK and p38 MAPK activation. PRKD2 silencing impaired activation of p44/42 MAPK and p54/46 JNK, downregulated nuclear c-Jun protein levels and decreased c-Jun S73 phosphorylation without affecting the NFκB pathway. Finally, qPCR array analyses revealed that silencing of PRKD2 downregulates mRNA levels of integrin alpha-2 and -4 (ITGA2 and -4), plasminogen activator urokinase (PLAU), plasminogen activator urokinase receptor (PLAUR), and matrix metallopeptidase 1 (MMP1). Findings of the present study identify PRKD2 as a potential target to interfere with glioblastoma cell migration and invasion, two major determinants contributing to recurrence of glioblastoma after multimodality treatment. Highlights: • Sphingosine-1-phosphate induces glioma cell migration and invasion. • Part of the effects is mediated by protein kinase D2 (PRKD2) activation. • Inactivation of PRKD2 attenuates glioblastoma cell migration and invasion. • Both, RNAi and pharmacological inhibition of PRKD2 inhibits MAPK

First-principles calculations for elastic properties of OsB2 under pressure

International Nuclear Information System (INIS)

Yang Junwei; Chen Xiangrong; Luo Fen; Ji Guangfu

2009-01-01

The structure, elastic properties and elastic anisotropy of orthorhombic OsB 2 are investigated by density functional theory method with the ultrasoft pseudopotential scheme in the frame of the generalized gradient approximation (GGA) as well as local density approximation (LDA). The obtained structural parameters, elastic constants, elastic anisotropy and Debye temperature for OsB 2 under pressure are consistent with the available experimental data and other theoretical results. It is found that the elastic constants, bulk modulus and Debye temperature of OsB 2 tend to increase with increasing pressure. It is predicted that OsB 2 is not a superhard material from our calculations.

First-principles calculations for elastic properties of OsB 2 under pressure

Science.gov (United States)

Yang, Jun-Wei; Chen, Xiang-Rong; Luo, Fen; Ji, Guang-Fu

2009-11-01

The structure, elastic properties and elastic anisotropy of orthorhombic OsB 2 are investigated by density functional theory method with the ultrasoft pseudopotential scheme in the frame of the generalized gradient approximation (GGA) as well as local density approximation (LDA). The obtained structural parameters, elastic constants, elastic anisotropy and Debye temperature for OsB 2 under pressure are consistent with the available experimental data and other theoretical results. It is found that the elastic constants, bulk modulus and Debye temperature of OsB 2 tend to increase with increasing pressure. It is predicted that OsB 2 is not a superhard material from our calculations.

Spontaneous complement activation on human B cells results in localized membrane depolarization and the clustering of complement receptor type 2 and C3 fragments

DEFF Research Database (Denmark)

Løbner, Morten; Leslie, Robert G Q; Prodinger, Wolfgang M

2009-01-01

While our previous studies have demonstrated that complement activation induced by complement receptors type 2 (CR2/CD21) and 1 (CR1/CD35) results in C3-fragment deposition and membrane attack complex (MAC) formation in human B cells, the consequences of these events for B-cell functions remain u...

Vapor space characterization of waste Tank 241-U-103: Results from samples collected on 2/15/95

International Nuclear Information System (INIS)

Ligotke, M.W.; Pool, K.H.; Clauss, T.W.; McVeety, B.D.; Klinger, G.S.; Olsen, K.B.; Bredt, O.P.; Fruchter, J.S.; Goheen, S.C.

1995-11-01

This report describes inorganic and organic analyses results from samples obtained from the headspace of the Hanford waste storage Tank 241-U-103 (referred to as Tank U-103). The results described her were obtained to support safety and toxicological evaluations. A summary of the results for inorganic and organic analytes is listed in Table 1. Detailed descriptions of the results appear in the text. Quantitative results were obtained for the inorganic compounds ammonia (NH 3 ), nitrogen dioxide (NO 2 ), nitric oxide (NO), and water vapor (H 2 O). Sampling for hydrogen cyanide (HCN) and sulfur oxides (SO x ) was not requested. In addition, quantitative results were obtained for the 39 TO-14 compounds plus an additional 14 analytes. Of these, 11 were observed above the 5-ppbv reporting cutoff. Eleven tentatively identified compounds (TICs) were observed above the reporting cutoff of (ca.) 10 ppbv and are reported with concentrations that are semiquantitative estimates based on internal-standard response factors. The 10 organic analytes with the highest estimated concentrations are listed in Table 1 and account for approximately 90% of the total organic components in Tank U-103. Two permanent gases, hydrogen (H 2 ) and nitrous oxide (N 2 O), were also detected. Tank U-103 is on the Hydrogen Watch List

Novel high pressure hexagonal OsB2 by mechanochemistry

International Nuclear Information System (INIS)

Xie, Zhilin; Graule, Moritz; Orlovskaya, Nina; Andrew Payzant, E.; Cullen, David A.; Blair, Richard G.

2014-01-01

Hexagonal OsB 2 , a theoretically predicted high-pressure phase, has been synthesized for the first time by a mechanochemical method, i.e., high energy ball milling. X-ray diffraction indicated that formation of hexagonal OsB 2 begins after 2.5 h of milling, and the reaction reaches equilibrium after 18 h of milling. Rietveld refinement of the powder data indicated that hexagonal OsB 2 crystallizes in the P63/mmc space group (No. 194) with lattice parameters of a=2.916 Å and c=7.376 Å. Transmission electron microscopy confirmed the appearance of the hexagonal OsB 2 phase after high energy ball milling. in situ X-ray diffraction experiments showed that the phase is stable from −225 °C to 1050 °C. The hexagonal OsB 2 powder was annealed at 1050 °C for 6 days in vacuo to improve crystallinity and remove strain induced during the mechanochemical synthesis. The structure partially converted to the orthorhombic phase (20 wt%) after fast current assisted sintering of hexagonal OsB 2 at 1500 °C for 5 min. Mechanochemical approaches to the synthesis of hard boride materials allow new phases to be produced that cannot be prepared using conventional methods. - Graphical abstract: High resolution transmission electron micrograph of hexagonal OsB 2 nanocrystallite with corresponding fast Fourier transform and simulated diffraction pattern. - Highlights: • Hexagonal OsB 2 has been synthesized for the first time by mechanochemical method. • Hexagonal OsB 2 crystallizes in P63/mmc space group (No. 194), a=2.916 Å and c=7.376 Å. • The hexagonal structure was confirmed by a transmission electron microscope. • No phase transformation was observed after being annealed at 1050 °C for 6 days. • 20 wt% of h-OsB 2 was transformed to o-OsB 2 after being sintered at 1500 °C for 5 min

Down-regulation of long non-coding RNA TUG1 inhibits osteosarcoma cell proliferation and promotes apoptosis.

Science.gov (United States)

Zhang, Qiang; Geng, Pei-Liang; Yin, Pei; Wang, Xiao-Lin; Jia, Jin-Peng; Yao, Jie

2013-01-01

To investigate the expression level of TUG1 and one of its transcript variants (n377360) in osteosarcoma cells and assess the role of TUG1 in proliferation and apoptosis in the U2OS cell line. TUG1 and n377360 expression levels in patients with osteosarcomas and the U2OS human osteosarcoma cell line were evaluated using real-time quantitative PCR. U2OS cells were transected with TUG1 and n377360 siRNA or non-targeting siRNA. MTS was performed to assess the cell proliferation and flow cytometry was applied to analyze apoptosis. We found significantly higher TUG1 and n377360 expression levels in osteosarcoma tissues compared with matched non-tumorous tissues. In line with this, suppression of TUG1 and n377360 expression by siRNA significantly impaired the cell proliferation potential of osteosarcoma cells. Furthermore, inhibition of TUG1 expression significantly promoted osteosarcoma cell apoptosis. The overexpression of TUG1 and n377360 in osteosarcoma specimens and the functional role of TUG1 and n377360 regarding cell proliferation and apoptosis in an osteosarcoma cell line provided evidence that the use of TUG1 or n377360 may be a viable but an as yet unexplored therapeutic strategy in tumors that over express these factors.

Suppression of multiple bioactivities of interleukin-1 and interleukin-2 production by U937 conditioned medium

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Wiblin, R.T.; Edmonds, K.; Ellner, J.J.

1986-01-01

The human macrophage-like cell line U937 spontaneously produces a factor which blocks interleukin-1 (IL-1) activity for mouse thymocytes but not mitosis of T-lymphoblastoid cells. The authors examined the effects of U937 conditioned medium (CM) on other IL-1 activities and on interleukin-2 (IL-2) production. U937 was cultured at 5 x 10 6 /ml in RPMI-1640 at 37 0 C for 5 days. The resulting CM inhibited the mitogenic response of C3H/HeJ mouse thymocytes to an IL-1 standard, with an inhibitory of activity of 6.64 U/ml (1 U = reciprocal dilution producing 50% inhibition of maximal response). Similarly, CM inhibited (10.12 U/ml) the fibroblast stimulation promoter activity of IL-1. The effect of CM on IL-2 production was assessed in a direct assay in which IL-2 production by γ-irradiated (12,000 rads) MLA-144 lymphosarcoma cells was assayed as 3 H-thymidine incorporation in CTLL-20 cells. The suppressive activity of CM was 4.95 U/ml; CM did not interfere with the response of CTLL-20 to IL-2. These studies establish that U937 produces factors with multiple, related biological activities; U937 CM blocks IL-2 dependent (thymocyte mitogenesis) and IL-2 independent (fibroblast proliferation) IL-1 activities and interferes with production of, but not response to, IL-2. U937 is an excellent model to study growth inhibitory properties of mononuclear phagocytes

Andrographolide Induces Autophagic Cell Death and Inhibits Invasion and Metastasis of Human Osteosarcoma Cells in An Autophagy-Dependent Manner

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Ying Liu

2017-11-01

Full Text Available Background/Aims: Osteosarcoma (OS is the most common primary malignant tumor of bone tissue. Although treatment effectiveness has improved, the OS survival rate has fluctuated in recent years. Andrographolide (AG has been reported to have antitumor activity against a variety of tumors. Our aim was to investigate the effects and potential mechanisms of AG in human osteosarcoma. Methods: Cell viability and morphological changes were assessed by MTT and live/dead assays. Apoptosis was detected using Annexin V-FITC/PI double staining, DAPI, and caspase-3 assays. Autophagy was detected with mRFP-GFP-LC3 adenovirus transfection and western blot. Cell migration and invasion were detected by wound healing assay and Transwell® experiments. Results: AG dose-dependently reduced the viability of osteosarcoma cells. No increase in apoptosis was detected in AG-treated human OS MG-63 and U-2OS cells, and the pan-caspase inhibitor z-VAD did not attenuate AG-induced cell death. However, AG induced autophagy by suppressing PI3K/Akt/mTOR and enhancing JNK signaling pathways. 3-MA and Beclin-1 siRNA could reverse the cytotoxic effects of AG. In addition, AG inhibited the invasion and metastasis of OS, and this effect could be reversed with Beclin-1 siRNA. Conclusion: AG inhibits viability and induces autophagic death in OS cells. AG-induced autophagy inhibits the invasion and metastasis of OS.

Protein kinase C isoforms in bovine aortic endothelial cells: role in regulation of P2Y- and P2U-purinoceptor-stimulated prostacyclin release.

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Patel, V; Brown, C; Boarder, M R

1996-05-01

1. Enhanced synthesis of prostacyclin (PGI2) and inositol polyphosphates in bovine aortic endothelial cells in response to ATP and ADP is mediated by co-existing P2Y- and P2U-purinoceptors. Here we examine the regulation of these responses by isoforms of protein kinase C (PKC). 2. Immunoblots with antisera specific for 8 different PKC isoforms revealed the presence of alpha, epsilon and zeta, while no immunoreactivity was found for beta, gamma, delta, eta and theta isoforms. PKC-alpha was largely cytosolic in unstimulated cells and almost all translocated to the membrane (Triton X-100 soluble) after a 1 min treatment with the PKC activating phorbol myristate acetate (PMA); PKC-epsilon was always in a Triton X-100 insoluble membrane fraction, while PKC-zeta was found in both soluble and membrane bound (Triton X-100 soluble) forms in the unstimulated cells and was unaffected by PMA. 3. Treatment with PMA for 6 h led to a 90% downregulation of PKC-alpha, while the immunoreactivity to the epsilon and zeta isoforms remained largely unchanged. 4. After either 10 min or 6 h exposure to PMA the PGI2 response to activation of both receptors was enhanced, while the inositol 1,4,5-trisphosphate response to P2Y-purinoceptor activation was substantially attenuated and the P2U-purinoceptor response was unchanged. Thus the PGI2 response to PMA under conditions when 90% of the PKC-alpha was lost resembles that seen on acute stimulation of PKC by PMA, and the PGI2 response does not correlate with phospholipase C response. 5. Inhibition of PKC with the isoform non-selective inhibitors, Ro 31-8220 and Go 6850 abolished the PGI2 response to both P2U- and P2Y-purinoceptor stimulation. However, Go 6976, which preferentially inhibits Ca2+ sensitive isoforms (such as PKC-alpha) and not Ca2+ insensitive isoforms (such as PKC-epsilon), had no effect on the PGI2 response. 6. The results show that there is a requirement for PKC in the stimulation of PGI2 production by endothelial P2Y- and P2U

Superconducting and Normal State Properties of OsB2*

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Singh, Yogesh; Niazi, A.; Zong, X.; Suh, B. J.; Vannette, M. W.; Prozorov, R.; Johnston, D. C.

2007-03-01

OsB2 is a layered superhard metallic material that was found to superconduct below Tc= 2.1 K.^1 We report the first detailed measurements of the static and dynamic magnetic susceptibilities χ, electrical resistivity, heat capacity Cp, penetration depth, and ^11B NMR on OsB2 to characterize its superconducting and normal state properties. The results confirm that OsB2 is a bulk superconductor below Tc= 2.1 K@. Its properties can be described by a close to weak-coupling s-wave BCS model with an electron-phonon coupling constant λ= 0.4--0.5, δ(0)/(kBTc) 1.9, a small Ginzburg-Landau parameter κ of order 5 or less, and a small zero-temperature critical magnetic field of roughly 500 Oe. The ^11B NMR measurements in the normal state show a nuclear spin-lattice relaxation time T1= 2.1 s at room temperature and a Korringa law with T1T = 610 s.K at lower T, and a correspondingly small T-independent Knight shift. These results indicate a small s character of the conduction electron wave function at the B site at the Fermi level. Our results will be compared to corresponding data for MgB2.1. J. K. Vandenberg et al., Mater. Res. Bull. 10, 889 (1975).^*Supported by the USDOE under Contract No. W-7405-Eng-82. Permanent address: Dept. Phys., The Catholic Univ. Korea.

Discriminating assimilants and decoupling deep- vs. shallow-level crystal records at Mount Adams using 238U-230Th disequilibria and Os isotopes

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Jicha, B.R.; Johnson, C.M.; Hildreth, Wes; Beard, B.L.; Hart, G.L.; Shirey, S.B.; Singer, B.S.

2009-01-01

A suite of 23 basaltic to dacitic lavas erupted over the last 350??kyr from the Mount Adams volcanic field has been analyzed for U-Th isotope compositions to evaluate the roles of mantle versus crustal components during magma genesis. All of the lavas have (230Th/238U) > 1 and span a large range in (230Th/232Th) ratios, and most basalts have higher (230Th/232Th) ratios than andesites and dacites. Several of the lavas contain antecrysts (crystals of pre-existing material), yet internal U-Th mineral isochrons from six of seven lavas are indistinguishable from their eruption ages. This indicates a relatively brief period of time between crystal growth and eruption for most of the phenocrysts (olivine, clinopyroxene, plagioclase, magnetite) prior to eruption. One isochron gave a crystallization age that is ~ 20-25??ka older than its corresponding eruptive age, and is interpreted to reflect mixing of older and juvenile crystals or a protracted period of magma storage in the crust. Much of the eruptive volume since 350??ka consists of lavas that have small to moderate 230Th excesses (2-16%), which are likely inherited from melting of a garnet-bearing intraplate ("OIB-like") mantle source. Following melt generation and subsequent migration through the upper mantle, most Mt. Adams magmas interacted with young, mafic lower crust, as indicated by 187Os/188Os ratios that are substantially more radiogenic than the mantle or those expected via mixing of subducted material and the mantle wedge. Moreover, Os-Th isotope variations suggest that unusually large 230Th excesses (25-48%) and high 187Os/188Os ratios in some peripheral lavas reflect assimilation of small degree partial melts of pre-Quaternary basement that had residual garnet or Al-rich clinopyroxene. Despite the isotopic evidence for lower crustal assimilation, these processes are not generally recorded in the erupted phenocrysts, indicating that the crystal record of the deep-level 'cryptic' processes has been

Synergism between arsenite and proteasome inhibitor MG132 over cell death in myeloid leukaemic cells U937 and the induction of low levels of intracellular superoxide anion

Energy Technology Data Exchange (ETDEWEB)

Lombardo, Tomás [Laboratorio de Immunotoxicologia (LaITO), IDEHU-CONICET, Hospital de Clínicas, José de San Martín, Universidad de Buenos Aires (UBA), Buenos Aires (Argentina); Cavaliere, Victoria; Costantino, Susana N. [Laboratorio de Inmunología Tumoral (LIT), IDEHU-CONICET, Facultad de Farmacia y Bioquímica, UBA, Buenos Aires (Argentina); Kornblihtt, Laura [Servicio de Hematología, Hospital de Clínicas, José de San Martín (UBA), Buenos Aires (Argentina); Alvarez, Elida M. [Laboratorio de Inmunología Tumoral (LIT), IDEHU-CONICET, Facultad de Farmacia y Bioquímica, UBA, Buenos Aires (Argentina); Blanco, Guillermo A., E-mail: gblanco@ffyb.uba.ar [Laboratorio de Immunotoxicologia (LaITO), IDEHU-CONICET, Hospital de Clínicas, José de San Martín, Universidad de Buenos Aires (UBA), Buenos Aires (Argentina)

2012-02-01

Increased oxygen species production has often been cited as a mechanism determining synergism on cell death and growth inhibition effects of arsenic-combined drugs. However the net effect of drug combination may not be easily anticipated solely from available knowledge of drug-induced death mechanisms. We evaluated the combined effect of sodium arsenite with the proteasome inhibitor MG132, and the anti-leukaemic agent CAPE, on growth-inhibition and cell death effect in acute myeloid leukaemic cells U937 and Burkitt's lymphoma-derived Raji cells, by the Chou–Talalay method. In addition we explored the association of cytotoxic effect of drugs with changes in intracellular superoxide anion (O{sub 2}{sup −}) levels. Our results showed that combined arsenite + MG132 produced low levels of O{sub 2}{sup −} at 6 h and 24 h after exposure and were synergic on cell death induction in U937 cells over the whole dose range, although the combination was antagonistic on growth inhibition effect. Exposure to a constant non-cytotoxic dose of 80 μM hydrogen peroxide together with arsenite + MG132 changed synergism on cell death to antagonism at all effect levels while increasing O{sub 2}{sup −} levels. Arsenite + hydrogen peroxide also resulted in antagonism with increased O{sub 2}{sup −} levels in U937 cells. In Raji cells, arsenite + MG132 also produced low levels of O{sub 2}{sup −} at 6 h and 24 h but resulted in antagonism on cell death and growth inhibition. By contrast, the combination arsenite + CAPE showed high levels of O{sub 2}{sup −} production at 6 h and 24 h post exposure but resulted in antagonism over cell death and growth inhibition effects in U937 and Raji cells. We conclude that synergism between arsenite and MG132 in U937 cells is negatively associated to O{sub 2}{sup −} levels at early time points after exposure. -- Highlights: ► Arsenic combined cytotoxic and anti-proliferative effects by Chou–Talalay method. ► Cytotoxic effect

Human U87 astrocytoma cell invasion induced by interaction of βig-h3 with integrin α5β1 involves calpain-2.

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Jie Ma

Full Text Available It is known that βig-h3 is involved in the invasive process of many types of tumors, but its mechanism in glioma cells has not been fully clarified. Using immunofluorescent double-staining and confocal imaging analysis, and co-immunoprecipitation assays, we found that βig-h3 co-localized with integrin α5β1 in U87 cells. We sought to elucidate the function of this interaction by performing cell invasion assays and gelatin zymography experiments. We found that siRNA knockdowns of βig-h3 and calpain-2 impaired cell invasion and MMP secretion. Moreover, βig-h3, integrins and calpain-2 are known to be regulated by Ca(2+, and they are also involved in tumor cell invasion. Therefore, we further investigated if calpain-2 was relevant to βig-h3-integrin α5β1 interaction to affect U87 cell invasion. Our data showed that βig-h3 co-localized with integrin α5β1 to enhance the invasion of U87 cells, and that calpain-2, is involved in this process, acting as a downstream molecule.

Vapor space characterization of Waste Tank 241-U-105: Results from samples collected on 2/24/95

International Nuclear Information System (INIS)

Pool, K.H.; Clauss, T.W.; Ligotke, M.W.

1995-10-01

This report describes inorganic and organic analyses results from samples obtained from the headspace of the Hanford waste storage Tank 241-U-105 (referred to as Tank U-105). The results described here were obtained to support safety and toxicological evaluations. A summary of the results for inorganic and organic analytes is listed in Table 1. Detailed descriptions of the results appear in the text. Quantitative results were obtained for the inorganic compounds ammonia (NH 3 ), nitrogen dioxide (NO 2 ), nitric oxide (NO), and water (H 2 O). Sampling for hydrogen cyanide (HCN) and sulfur oxides (SO x ) was not requested. In addition, quantitative results were obtained for the 39 TO-14 compounds plus an additional 14 analytes. Of these, six were observed above the 5-ppbv reporting cutoff. Three tentatively identified compounds (TICs) were observed above the reporting cutoff of (ca.) 10 ppbv and are reported with concentrations that are semiquantitative estimates based on internal-standard response factors. All nine of the organic analytes identified are listed in Table 1 and account for 100% of the total organic components in Tank U-105. Nitrous oxide (N 2 O) was the only permanent gas detected in the tank-headspace sample. Tank U-105 is on the Hydrogen Watch List

Anaerobic U(IV) Bio-oxidation and the Resultant Remobilization of Uranium in Contaminated Sediments

International Nuclear Information System (INIS)

Coates, John D.

2005-01-01

A proposed strategy for the remediation of uranium (U) contaminated sites is based on immobilizing U by reducing the oxidized soluble U, U(VI), to form a reduced insoluble end product, U(IV). Due to the use of nitric acid in the processing of nuclear fuels, nitrate is often a co-contaminant found in many of the environments contaminated with uranium. Recent studies indicate that nitrate inhibits U(VI) reduction in sediment slurries. However, the mechanism responsible for the apparent inhibition of U(VI) reduction is unknown, i.e. preferential utilization of nitrate as an electron acceptor, direct biological oxidation of U(IV) coupled to nitrate reduction, and/or abiotic oxidation by intermediates of nitrate reduction. Recent studies indicates that direct biological oxidation of U(IV) coupled to nitrate reduction may exist in situ, however, to date no organisms have been identified that can grow by this metabolism. In an effort to evaluate the potential for nitrate-dependent bio-oxidation of U(IV) in anaerobic sedimentary environments, we have initiated the enumeration of nitrate-dependent U(IV) oxidizing bacteria. Sediments, soils, and groundwater from uranium (U) contaminated sites, including subsurface sediments from the NABIR Field Research Center (FRC), as well as uncontaminated sites, including subsurface sediments from the NABIR FRC and Longhorn Army Ammunition Plant, Texas, lake sediments, and agricultural field soil, sites served as the inoculum source. Enumeration of the nitrate-dependent U(IV) oxidizing microbial population in sedimentary environments by most probable number technique have revealed sedimentary microbial populations ranging from 9.3 x 101 - 2.4 x 103 cells (g sediment)-1 in both contaminated and uncontaminated sites. Interestingly uncontaminated subsurface sediments (NABIR FRC Background core FB618 and Longhorn Texas Core BH2-18) both harbored the most numerous nitrate-dependent U(IV) oxidizing population 2.4 x 103 cells (g sediment)-1

Molybdenite Re-Os, zircon U-Pb dating and Lu-Hf isotopic analysis of the Xiaerchulu Au deposit, Inner Mongolia Province, China

Science.gov (United States)

Wang, Jia-xin; Nie, Feng-Jun; Zhang, Xue-ni; Jiang, Si-hong

2016-09-01

The Xiaerchulu Au deposit, located in the Southern Orogenic Belt (SOB) of Western Inner Mongolia (WIM), is hosted in an Early Permian (271-261 Ma) volcanic-plutonic sequence. Mineralization took place in silicified biotite granites or along the contact zone between the Neoproterozoic Baiyinbaolage Group and the biotite granite. In order to constrain the timing of the Xiaerchulu mineralization and discuss the petrogenesis of the hosting granites, molybdenite Re-Os, and zircon U-Pb and, Lu-Hf, and REE, geochemical, and Sr-Nd isotopic studies were completed in this study. We measured Re-Os isotopes of six molybdenite samples from the main ore body, which yielded a weighted average model age of 261.7 ± 1.5 Ma with a MSWD of 0.55, indicating that the time of mineralization was at ca. 262 Ma. High precision U-Pb dating for the studied granites yields Permian 206Pb/238U ages ranging from 271 to 269 Ma. These age data confirm that both the intrusion and related mineralization were initiated in Early Permian period. These granites are strongly peraluminous with A/CNK = 1.11-1.12, high SiO2-K2O contents, as well as containing biotite and muscovite, indicating a petrogenesis of typical S-type granites, the above consideration is also consistent with the result of discrimination diagrams. The Re contents of molybdenite, εNd(t), and zircon εHf(t), as well as the 176Hf/177Hf values of the granites, fall into the ranges from 1.153 to 2.740 μg/g, - 11.1 to - 9.3, - 8.8 to - 0.9, and 0.282358 to 0.282688, respectively. All of this evidence suggests that the metals were derived from a predominantly crustal source, the granites originated from crust in an extensional setting, and the rejuvenation of the continent may have play an important role during the ore-forming processes of the Early Permian epoch.

Acute dyskerin depletion triggers cellular senescence and renders osteosarcoma cells resistant to genotoxic stress-induced apoptosis

International Nuclear Information System (INIS)

Lin, Ping; Mobasher, Maral E.; Alawi, Faizan

2014-01-01

Highlights: • Dyskerin depletion triggers cellular senescence in U2OS osteosarcoma cells. • Dyskerin-depleted cells are resistant to apoptosis induced by genotoxic stress. • Chromatin relaxation sensitizes dyskerin-depleted cells to apoptosis. - Abstract: Dyskerin is a conserved, nucleolar RNA-binding protein implicated in an increasing array of fundamental cellular processes. Germline mutation in the dyskerin gene (DKC1) is the cause of X-linked dyskeratosis congenita (DC). Conversely, wild-type dyskerin is overexpressed in sporadic cancers, and high-levels may be associated with poor prognosis. It was previously reported that acute loss of dyskerin function via siRNA-mediated depletion slowed the proliferation of transformed cell lines. However, the mechanisms remained unclear. Using human U2OS osteosarcoma cells, we show that siRNA-mediated dyskerin depletion induced cellular senescence as evidenced by proliferative arrest, senescence-associated heterochromatinization and a senescence-associated molecular profile. Senescence can render cells resistant to apoptosis. Conversely, chromatin relaxation can reverse the repressive effects of senescence-associated heterochromatinization on apoptosis. To this end, genotoxic stress-induced apoptosis was suppressed in dyskerin-depleted cells. In contrast, agents that induce chromatin relaxation, including histone deacetylase inhibitors and the DNA intercalator chloroquine, sensitized dyskerin-depleted cells to apoptosis. Dyskerin is a core component of the telomerase complex and plays an important role in telomere homeostasis. Defective telomere maintenance resulting in premature senescence is thought to primarily underlie the pathogenesis of X-linked DC. Since U2OS cells are telomerase-negative, this leads us to conclude that loss of dyskerin function can also induce cellular senescence via mechanisms independent of telomere shortening

A new superhard material: Osmium diboride OsB 2

Science.gov (United States)

Hebbache, M.; Stuparević, L.; Živković, D.

2006-08-01

Superhard materials have many industrial applications, wherever resistance to abrasion and wear are important. The synthesis of new superhard materials is one of the great challenges to scientists. We re-examined the phase diagram of the binary osmium-boron system and confirmed the existence of two hexagonal phases, OsB 1.1, Os 2B 3, and an orthorhombic phase, OsB 2. Almost nothing is known about the physical properties of osmium borides. Microhardness measurements show that OsB 2 is extremely hard. Ab initio calculations show that this is due to formation of covalent bonds between boron atoms. OsB 2 is also a low compressibility material. It can be used as hard coating.

miR-130b targets NKD2 and regulates the Wnt signaling to promote proliferation and inhibit apoptosis in osteosarcoma cells

Energy Technology Data Exchange (ETDEWEB)

Li, Zhi [Department of Human Anatomy and Histoembryology, College of Basic Medical Sciences, Jilin University (China); Li, Youjun, E-mail: liyoujunn@126.com [Department of Human Anatomy and Histoembryology, College of Basic Medical Sciences, Jilin University (China); Wang, Nan; Yang, Lifeng; Zhao, Wei; Zeng, Xiandong [Central Hospital Affiliated to Shenyang Medical College (China)

2016-03-18

miR-130b was significantly up-regulated in osteosarcoma (OS) cells. Naked cuticle homolog 2 (NKD2) inhibited tumor growth and metastasis in OS by suppressing Wnt signaling. We used three miRNA target analysis tools to identify potential targets of miR-130b, and found that NKD2 is a potential target of miR-130b. Based on these findings, we hypothesize that miR-130b might target NKD2 and regulate the Wnt signaling to promote OS growth. We detected the expression of miR-130b and NKD2 mRNA and protein by quantitative Real-Time PCR (qRT-PCR) and western blot assays, respectively, and found up-regulation of miR-130b and down-regulation of NKD2 mRNA and protein exist in OS cell lines. MTT and flow cytometry assays showed that miR-130b inhibitors inhibit proliferation and promote apoptosis in OS cells. Furthermore, we showed that NKD2 is a direct target of miR-130b, and miR-130b regulated proliferation and apoptosis of OS cells by targeting NKD2. We further investigated whether miR-130b and NKD2 regulate OS cell proliferation and apoptosis by inhibiting Wnt signaling, and the results confirmed our speculation that miR-130b targets NKD2 and regulates the Wnt signaling to promote proliferation and inhibit apoptosis of OS cells. These findings will offer new clues for OS development and progression, and novel potential therapeutic targets for OS. - Highlights: • miR-130b is up-regulated and NKD2 is down-regulated in osteosarcoma cell lines. • Down-regulation of miR-130b inhibits proliferation of osteosarcoma cells. • Down-regulation of miR-130b promotes apoptosis of osteosarcoma cells. • miR-130b directly targets NKD2. • NKD2 regulates OS cell proliferation and apoptosis by inhibiting the Wnt signaling.

miR-130b targets NKD2 and regulates the Wnt signaling to promote proliferation and inhibit apoptosis in osteosarcoma cells

International Nuclear Information System (INIS)

Li, Zhi; Li, Youjun; Wang, Nan; Yang, Lifeng; Zhao, Wei; Zeng, Xiandong

2016-01-01

miR-130b was significantly up-regulated in osteosarcoma (OS) cells. Naked cuticle homolog 2 (NKD2) inhibited tumor growth and metastasis in OS by suppressing Wnt signaling. We used three miRNA target analysis tools to identify potential targets of miR-130b, and found that NKD2 is a potential target of miR-130b. Based on these findings, we hypothesize that miR-130b might target NKD2 and regulate the Wnt signaling to promote OS growth. We detected the expression of miR-130b and NKD2 mRNA and protein by quantitative Real-Time PCR (qRT-PCR) and western blot assays, respectively, and found up-regulation of miR-130b and down-regulation of NKD2 mRNA and protein exist in OS cell lines. MTT and flow cytometry assays showed that miR-130b inhibitors inhibit proliferation and promote apoptosis in OS cells. Furthermore, we showed that NKD2 is a direct target of miR-130b, and miR-130b regulated proliferation and apoptosis of OS cells by targeting NKD2. We further investigated whether miR-130b and NKD2 regulate OS cell proliferation and apoptosis by inhibiting Wnt signaling, and the results confirmed our speculation that miR-130b targets NKD2 and regulates the Wnt signaling to promote proliferation and inhibit apoptosis of OS cells. These findings will offer new clues for OS development and progression, and novel potential therapeutic targets for OS. - Highlights: • miR-130b is up-regulated and NKD2 is down-regulated in osteosarcoma cell lines. • Down-regulation of miR-130b inhibits proliferation of osteosarcoma cells. • Down-regulation of miR-130b promotes apoptosis of osteosarcoma cells. • miR-130b directly targets NKD2. • NKD2 regulates OS cell proliferation and apoptosis by inhibiting the Wnt signaling.

Recent TMX-U central cell heating and fueling experiments

International Nuclear Information System (INIS)

Hooper, E.B. Jr.; Barter, J.; Dimonte, G.; Falabella, S.; Molvik, A.W.; Pincosy, P.; Turner, W.C.

1986-01-01

Recent experiments have begun to test new methods of heating and fueling of the TMX-U central cell plasma. Heating is with ICRH and 2kV neutral beams. Fueling is by the 2kV beams and by gas puffing. The ICRH system used for fundamental-frequency slow-wave heating consists of two double half-turn antennas, with one on each side of the central cell midplane at mirror ratios of 1:3 and 1:5. Gas fueling is between these two antennas to ensure that recently ionized particles pass through an ICRH resonance before entering the thermal barrier and cells. In recent gas-fed experiments with 100 to 200kW power on each antenna, the end loss temperature was measured to increase from 30eV to above 150eV with perpendicular (cc) temperatures of >500eV. The TMX-U central cell has been equipped with 10 low energy neutral-beam injectors (LENI). These beams are designed to operate at 2kV (net) accel-voltage and deliver 17 atom amperes each to the TMX-U plasma. This low energy was selected to improve trapping (relative to higher energy) on the initial ICRH heated plasma (2X10/sup 12/ cm/sup -3/). At 2keV the beams are predicted to be capable of building up and fueling to 10/sup 13/ cm/sup -3/ density, with ion-ion scattering providing a warm, isotropic ion component in the central cell

Rice MEL2, the RNA recognition motif (RRM) protein, binds in vitro to meiosis-expressed genes containing U-rich RNA consensus sequences in the 3'-UTR.

Science.gov (United States)

Miyazaki, Saori; Sato, Yutaka; Asano, Tomoya; Nagamura, Yoshiaki; Nonomura, Ken-Ichi

2015-10-01

Post-transcriptional gene regulation by RNA recognition motif (RRM) proteins through binding to cis-elements in the 3'-untranslated region (3'-UTR) is widely used in eukaryotes to complete various biological processes. Rice MEIOSIS ARRESTED AT LEPTOTENE2 (MEL2) is the RRM protein that functions in the transition to meiosis in proper timing. The MEL2 RRM preferentially associated with the U-rich RNA consensus, UUAGUU[U/A][U/G][A/U/G]U, dependently on sequences and proportionally to MEL2 protein amounts in vitro. The consensus sequences were located in the putative looped structures of the RNA ligand. A genome-wide survey revealed a tendency of MEL2-binding consensus appearing in 3'-UTR of rice genes. Of 249 genes that conserved the consensus in their 3'-UTR, 13 genes spatiotemporally co-expressed with MEL2 in meiotic flowers, and included several genes whose function was supposed in meiosis; such as Replication protein A and OsMADS3. The proteome analysis revealed that the amounts of small ubiquitin-related modifier-like protein and eukaryotic translation initiation factor3-like protein were dramatically altered in mel2 mutant anthers. Taken together with transcriptome and gene ontology results, we propose that the rice MEL2 is involved in the translational regulation of key meiotic genes on 3'-UTRs to achieve the faithful transition of germ cells to meiosis.

Rice pectin methylesterase inhibitor28 (OsPMEI28) encodes a functional PMEI and its overexpression results in a dwarf phenotype through increased pectin methylesterification levels.

Science.gov (United States)

Nguyen, Hong Phuong; Jeong, Ho Young; Jeon, Seung Ho; Kim, Donghyuk; Lee, Chanhui

2017-01-01

Pectin methylesterases (PMEs, EC 3.1.1.11) belonging to carbohydrate esterase family 8 cleave the ester bond between a galacturonic acid and an methyl group and the resulting change in methylesterification level plays an important role during the growth and development of plants. Optimal pectin methylesterification status in each cell type is determined by the balance between PME activity and post-translational PME inhibition by PME inhibitors (PMEIs). Rice contains 49 PMEIs and none of them are functionally characterized. Genomic sequence analysis led to the identification of rice PMEI28 (OsPMEI28). Recombinant OsPMEI28 exhibited inhibitory activity against commercial PME protein with the highest activities detected at pH 8.5. Overexpression of OsPMEI28 in rice resulted in an increased level of cell wall bound methylester groups and differential changes in the composition of cell wall neutral monosaccharides and lignin content in culm tissues. Consequently, transgenic plants overexpressing OsPMEI28 exhibited dwarf phenotypes and reduced culm diameter. Our data indicate that OsPMEI28 functions as a critical structural modulator by regulating the degree of pectin methylesterification and that an impaired status of pectin methylesterification affects physiochemical properties of the cell wall components and causes abnormal cell extensibility in rice culm tissues. Copyright © 2016 Elsevier GmbH. All rights reserved.

Molecular mechanisms of the 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced inverted U-shaped dose responsiveness in anchorage independent growth and cell proliferation of human breast epithelial cells with stem cell characteristics

International Nuclear Information System (INIS)

Ahn, Nam-Shik; Hu, Hongbo; Park, Jin-Sung; Park, Joon-Suk; Kim, Jong-Sik; An, Sungwhan; Kong, Gu; Aruoma, Okezie I.; Lee, Yong-Soon; Kang, Kyung-Sun

2005-01-01

Although 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has a variety of carcinogenic and noncarcinogenic effects in experimental animals, its role in human carcinogenicity remain controversial. A simian virus 40-immortalized cell line from normal human breast epithelial cells with stem cells and luminal characteristics (M13SV1) was used to study whether TCDD can induce AIG positive colony formation and cause increased cell numbers in a inverted U-shaped dose-response manner. TCDD activated Akt, ERK2, and increased the expression of CYP1A1, PAI-2, IL-lb mRNA, and ERK2 protein levels. TCDD was able to increased phosphorylation and expression of ERK2 in same dose-response manner as AIG positive colony formation. Thus, TCDD induced tumorigenicity in M13SV1, possibly through the phosphorylation of ERK2 and/or Akt. Further, cDNA microarray with 7448 sequence-verified clones was used to profile various gene expression patterns after treatment of TCDD. Three clear patterns could be delineated: genes that were dose-dependently up-regulated, genes expressed in either U-shape and/or inverted U-shape. The fact that these genes are intrinsically related to breast epithelial cell proliferation and survival clearly suggests that they may be involved in the TCDD-induced breast tumorigenesis

Functional characterization of the SIZ/PIAS-type SUMO E3 ligases, OsSIZ1 and OsSIZ2 in rice

KAUST Repository

Park, Hyeongcheol; Kim, Hun; Koo, Sungcheol; Park, Heejin; Cheong, Misun; Hong, Hyewon; Baek, Dongwon; Chung, Woosik; Kim, Dohhoon; Bressan, Ray Anthony; Lee, Sangyeol; Bohnert, Hans Jü rgen; Yun, Daejin

2010-01-01

Sumoylation is a post-translational regulatory process in diverse cellular processes in eukaryotes, involving conjugation/deconjugation of small ubiquitin-like modifier (SUMO) proteins to other proteins thus modifying their function. The PIAS [protein inhibitor of activated signal transducers and activators of transcription (STAT)] and SAP (scaffold attachment factor A/B/acinus/PIAS)/MIZ (SIZ) proteins exhibit SUMO E3-ligase activity that facilitates the conjugation of SUMO proteins to target substrates. Here, we report the isolation and molecular characterization of Oryza sativa SIZ1 (OsSIZ1) and SIZ2 (OsSIZ2), rice homologs of Arabidopsis SIZ1. The rice SIZ proteins are localized to the nucleus and showed sumoylation activities in a tobacco system. Our analysis showed increased amounts of SUMO conjugates associated with environmental stresses such as high and low temperature, NaCl and abscisic acid (ABA) in rice plants. The expression of OsSIZ1 and OsSIZ2 in siz1-2 Arabidopsis plants partially complemented the morphological mutant phenotype and enhanced levels of SUMO conjugates under heat shock conditions. In addition, ABA-hypersensitivity of siz1-2 seed germination was partially suppressed by OsSIZ1 and OsSIZ2. The results suggest that rice SIZ1 and SIZ2 are able to functionally complement Arabidopsis SIZ1 in the SUMO conjugation pathway. Their effects on the Arabidopsis mutant suggest a function for these genes related to stress responses and stress adaptation. © 2010 Blackwell Publishing Ltd.

Functional characterization of the SIZ/PIAS-type SUMO E3 ligases, OsSIZ1 and OsSIZ2 in rice

KAUST Repository

Park, Hyeongcheol

2010-06-18

Sumoylation is a post-translational regulatory process in diverse cellular processes in eukaryotes, involving conjugation/deconjugation of small ubiquitin-like modifier (SUMO) proteins to other proteins thus modifying their function. The PIAS [protein inhibitor of activated signal transducers and activators of transcription (STAT)] and SAP (scaffold attachment factor A/B/acinus/PIAS)/MIZ (SIZ) proteins exhibit SUMO E3-ligase activity that facilitates the conjugation of SUMO proteins to target substrates. Here, we report the isolation and molecular characterization of Oryza sativa SIZ1 (OsSIZ1) and SIZ2 (OsSIZ2), rice homologs of Arabidopsis SIZ1. The rice SIZ proteins are localized to the nucleus and showed sumoylation activities in a tobacco system. Our analysis showed increased amounts of SUMO conjugates associated with environmental stresses such as high and low temperature, NaCl and abscisic acid (ABA) in rice plants. The expression of OsSIZ1 and OsSIZ2 in siz1-2 Arabidopsis plants partially complemented the morphological mutant phenotype and enhanced levels of SUMO conjugates under heat shock conditions. In addition, ABA-hypersensitivity of siz1-2 seed germination was partially suppressed by OsSIZ1 and OsSIZ2. The results suggest that rice SIZ1 and SIZ2 are able to functionally complement Arabidopsis SIZ1 in the SUMO conjugation pathway. Their effects on the Arabidopsis mutant suggest a function for these genes related to stress responses and stress adaptation. © 2010 Blackwell Publishing Ltd.

The OsO(3)F(+) and mu-F(OsO(3)F)(2)(+) cations: their syntheses and study by Raman and (19)F NMR spectroscopy and electron structure calculations and X-ray crystal structures of [OsO(3)F][PnF(6)] (Pn = As, Sb), [OsO(3)F][HF](2)[AsF(6)], [OsO(3)F][HF][SbF(6)], and [OsO(3)F][Sb(3)F(16)].

Science.gov (United States)

Gerken, Michael; Dixon, David A; Schrobilgen, Gary J

2002-01-28

The fluoride ion donor properties of OsO(3)F(2) have been investigated. The salts [OsO(3)F][AsF(6)], [OsO(3)F][HF](2)[AsF(6)], mu-F(OsO(3)F)(2)[AsF(6)], [OsO(3)F][HF](2)[SbF(6)], and [OsO(3)F][HF][SbF(6)] have been prepared by reaction of OsO(3)F(2) with AsF(5) and SbF(5) in HF solvent and have been characterized in the solid state by Raman spectroscopy. The single-crystal X-ray diffraction studies of [OsO(3)F][AsF(6)] (P2(1)/n, a = 7.0001(11) A, c = 8.8629(13) A, beta = 92.270(7) degrees, Z = 4, and R(1) = 0.0401 at -126 degrees C), [OsO(3)F][SbF(6)] (P2(1)/c, a = 5.4772(14) A, b = 10.115(3) A, c = 12.234(3) A, beta = 99.321(5) degrees, Z = 4, and R(1) = 0.0325 at -173 degrees C), [OsO(3)F][HF](2)[AsF(6)] (P2(1)/n, a = 5.1491(9) A, b = 8.129(2) A, c = 19.636(7) A, beta = 95.099(7) degrees, Z = 4, and R(1) = 0.0348 at -117 degrees C), and [OsO(3)F][HF][SbF(6)] (Pc, a = 5.244(4) A, b = 9.646(6) A, c = 15.269(10) A, beta = 97.154(13) degrees, Z = 4, and R(1) = 0.0558 at -133 degrees C) have shown that the OsO(3)F(+) cations exhibit strong contacts to the anions and HF solvent molecules giving rise to cyclic, dimeric structures in which the osmium atoms have coordination numbers of 6. The reaction of OsO(3)F(2) with neat SbF(5) yielded [OsO(3)F][Sb(3)F(16)], which has been characterized by (19)F NMR spectroscopy in SbF(5) and SO(2)ClF solvents and by Raman spectroscopy and single-crystal X-ray diffraction in the solid state (P4(1)m, a = 10.076(6) A, c = 7.585(8) A, Z = 2, and R(1) = 0.0858 at -113 degrees C). The weak fluoride ion basicity of the Sb(3)F(16)(-) anion resulted in an OsO(3)F(+) cation (C(3)(v) point symmetry) that is well isolated from the anion and in which the osmium is four-coordinate. The geometrical parameters and vibrational frequencies of OsO(3)F(+), ReO(3)F, mu-F(OsO(3)F)(2)(+), (FO(3)Os--FPnF(5))(2), and (FO(3)Os--(HF)(2)--FPnF(5))(2) (Pn = As, Sb) have been calculated using density functional theory methods.

Oxalomalate, a competitive inhibitor of NADP+ -dependent isocitrate dehydrogenase, regulates lipid peroxidation-mediated apoptosis in U937 cells.

Science.gov (United States)

Yang, Eun Sun; Yang, Joon-Hyuck; Park, Ji Eun; Park, Jeen-Woo

2005-01-01

Membrane lipid peroxidation processes yield products that may react with DNA and proteins to cause oxidative modifications. Recently, we demonstrated that the control of cytosolic redox balance and the cellular defense against oxidative damage is one of the primary functions of cytosolic NADP+ -dependent isocitrate dehydrogenase (IDPc) through to supply NADPH for antioxidant systems. The protective role of IDPc against lipid peroxidation-mediated apoptosis in U937 cells was investigated in control and cells pre-treated with oxlalomalate, a competitive inhibitor of IDPc. Upon exposure to 2,2'-azobis (2-amidinopropane) hydrochloride (AAPH) to U937 cells, which induces lipid peroxidation in membranes, the susceptibility to apoptosis was higher in oxalomalate-treated cells as compared to control cells. The results suggest that IDPc plays an important protective role in apoptosis of U937 cells induced by lipid peroxidation-mediated oxidative stress.

Syntheses, Raman spectra, and X-ray crystal structures of [XeF(5)][mu-F(OsO(3)F(2))(2)] and [M][OsO(3)F(3)] (M = XeF(5)(+), Xe(2)F(11)(+)).

Science.gov (United States)

Hughes, Michael J; Mercier, Hélène P A; Schrobilgen, Gary J

2010-04-05

Stoichiometric amounts of XeF(6) and (OsO(3)F(2))(infinity) react at 25-50 degrees C to form salts of the known XeF(5)(+) and Xe(2)F(11)(+) cations, namely, [XeF(5)][mu-F(OsO(3)F(2))(2)], [XeF(5)][OsO(3)F(3)], and [Xe(2)F(11)][OsO(3)F(3)]. Although XeF(6) is oxophilic toward a number of transition metal and main-group oxides and oxide fluorides, fluoride/oxide metathesis was not observed. The series provides the first examples of noble-gas cations that are stabilized by metal oxide fluoride anions and the first example of a mu-F(OsO(3)F(2))(2)(-) salt. Both [XeF(5)][mu-F(OsO(3)F(2))(2)] and [Xe(2)F(11)][OsO(3)F(3)] are orange solids at room temperature. The [XeF(5)][OsO(3)F(3)] salt is an orange liquid at room temperature that solidifies at 5-0 degrees C. When the salts are heated at 50 degrees C under 1 atm of N(2) for more than 2 h, significant XeF(6) loss occurs. The X-ray crystal structures (-173 degrees C) show that the salts exist as discrete ion pairs and that the osmium coordination spheres in OsO(3)F(3)(-) and mu-F(OsO(3)F(2))(2)(-) are pseudo-octahedral OsO(3)F(3)-units having facial arrangements of oxygen and fluorine atoms. The mu-F(OsO(3)F(2))(2)(-) anion is comprised of two symmetry-related OsO(3)F(2)-groups that are fluorine-bridged to one another. Ion pairing results from secondary bonding interactions between the fluorine/oxygen atoms of the anions and the xenon atom of the cation, with the Xe...F/O contacts occurring opposite the axial fluorine and from beneath the equatorial XeF(4)-planes of the XeF(5)(+) and Xe(2)F(11)(+) cations so as to avoid the free valence electron lone pairs of the xenon atoms. The xenon atoms of [XeF(5)][mu-F(OsO(3)F(2))(2)] and [Xe(2)F(11)][OsO(3)F(3)] are nine-coordinate and the xenon atom of [XeF(5)][OsO(3)F(3)] is eight-coordinate. Quantum-chemical calculations at SVWN and B3LYP levels of theory were used to obtain the gas-phase geometries, vibrational frequencies, and NBO bond orders, valencies, and NPA charges of

First-principles calculations for elastic properties of OsB{sub 2} under pressure

Energy Technology Data Exchange (ETDEWEB)

Yang Junwei [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China); Chen Xiangrong, E-mail: x.r.chen@tom.co [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China); International Centre for Materials Physics, Chinese Academy of Sciences, Shenyang 110016 (China); Luo Fen [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China); Ji Guangfu [Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, Chinese Academy of Engineering Physics, Mianyang 621900 (China)

2009-11-01

The structure, elastic properties and elastic anisotropy of orthorhombic OsB{sub 2} are investigated by density functional theory method with the ultrasoft pseudopotential scheme in the frame of the generalized gradient approximation (GGA) as well as local density approximation (LDA). The obtained structural parameters, elastic constants, elastic anisotropy and Debye temperature for OsB{sub 2} under pressure are consistent with the available experimental data and other theoretical results. It is found that the elastic constants, bulk modulus and Debye temperature of OsB{sub 2} tend to increase with increasing pressure. It is predicted that OsB{sub 2} is not a superhard material from our calculations.

Vapor space characterization of Waste Tank 241-U-107: Results from samples collected on 2/17/95

International Nuclear Information System (INIS)

McVeety, B.D.; Clauss, T.W.; Ligotke, M.W.

1995-10-01

This report describes inorganic and organic analyses results from samples obtained from the headspace of the Hanford waste storage Tank 241-U-107 (referred to as Tank U-107). The results described here were obtained to support safety and toxicological evaluations. A summary of the results for inorganic and organic analytes is listed in Table 1. Detailed descriptions of the results appear in the text. Quantitative results were obtained for the inorganic compounds ammonia (NH 3 ), nitrogen dioxide (NO 2 ), nitric oxide (NO), and water (H 2 O). Sampling for hydrogen cyanide (HCN) and sulfur oxides (SO x ) was not requested. In addition, quantitative results were obtained for the 39 TO-14 compounds plus an additional 14 analytes. Of these, 10 were observed above the 5-ppbv reporting cutoff. Sixteen organic tentatively identified compounds (TICs) were observed above the reporting cutoff of (ca.) 10 ppbv, and are reported with concentrations that are semiquantitative estimates based on internal-standard response factors. The 10 organic analytes with the highest estimated concentrations are listed in Table 1 and account for approximately 88% of the total organic components in Tank U-107. Nitrous oxide (N 2 O) was the only permanent gas detected in the tank-headspace samples. Tank U-107 is on the Organic and the Hydrogen Watch Lists

Preparation and characterisation of Os doped MgB{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Grivel, J.-C., E-mail: jean@dtu.dk; Namazkar, S.; Alexiou, A.; Holte, O.J.

2014-12-15

Highlights: • Polycrystalline osmium doped MgB{sub 2} samples were prepared by solid state route. • Up to 1 at.% Mg can be replaced by Os in the MgB{sub 2} lattice. • T{sub c} decreases at a rate of 2.1 K/at.% Os upon doping. - Abstract: Polycrystalline samples with Mg{sub 1−x}Os{sub x}B{sub 2.04} nominal stoichiometry were made by reacting elemental powders at 800 °C under argon atmosphere. Based on XRD diffraction patterns, EDS analysis and magnetisation measurements, it is found that Os can replace up to about 1 at.% Mg in the MgB{sub 2} lattice. Beyond this doping level, unreacted Os and Mg-rich Mg–Os impurity phases are formed. The a-axis parameter contracts upon doping while the superconducting transition temperature decreases at a rate of 2.1 K/at.% Os substitution. At 10 K, Os doping induces an improvement of the normalised critical current density under applied magnetic fields in excess of 0.5 T, indicating a modest enhancement of flux pinning in this range.

OsGA2ox5, a Gibberellin Metabolism Enzyme, Is Involved in Plant Growth, the Root Gravity Response and Salt Stress

Science.gov (United States)

Cai, Weiming; Shan, Chi

Gibberellin (GA) 2-oxidases play an important role in the GA catabolic pathway through 2b-hydroxylation. There are two classes of GA2oxs, i.e., a larger class of C19-GA2oxs and a smaller class of C20-GA2oxs. In this study, the gene encoding a GA 2-oxidase of rice, Oryza sativa GA 2-oxidase 5 (OsGA2ox5), was cloned and characterized. BLASTP analysis showed that OsGA2ox5 belongs to the C20-GA2oxs subfamily, a subfamily of GA2oxs acting on C20-GAs (GA12, GA53). Subcellular localization of OsGA2ox5-YFP in transiently transformed onion epidermal cells revealed the presence of this protein in both of the nucleus and cytoplasm. Real-time PCR analysis, along with GUS staining, revealed that OsGA2ox5 is expressed in the roots, culms, leaves, sheaths and panicles of rice. Rice plants overexpressing OsGA2ox5 exhibited dominant dwarf and GAdeficient phenotypes, with shorter stems and later development of reproductive organs than the wild type. The dwarfism phenotype was partially rescued by the application of exogenous GA3 at a concentration of 10 mM. Ectopic expression of OsGA2ox5 cDNA in Arabidopsis resulted in a similar phenotype. Real-time PCR assays revealed that both GA synthesis-related genes and GA signaling genes were expressed at higher levels in transgenic rice plants than in wild-type rice; OsGA3ox1, which encodes a key enzyme in the last step of the bioactive GAs synthesis pathway, was highly expressed in transgenic rice. The roots of OsGA2ox5-ox plants exhibited increased starch granule accumulation and gravity responses, revealing a role for GA in root starch granule development and gravity responses. Furthermore, rice and Arabidopsis plants overexpressing OsGA2ox5 were more resistant to high-salinity stress than wild-type plants. These results suggest that OsGA2ox5 plays important roles in GAs homeostasis, development, gravity responses and stress tolerance in rice.

OsGA2ox5, a gibberellin metabolism enzyme, is involved in plant growth, the root gravity response and salt stress.

Directory of Open Access Journals (Sweden)

Chi Shan

Full Text Available Gibberellin (GA 2-oxidases play an important role in the GA catabolic pathway through 2β-hydroxylation. There are two classes of GA2oxs, i.e., a larger class of C₁₉-GA2oxs and a smaller class of C₂₀-GA2oxs. In this study, the gene encoding a GA 2-oxidase of rice, Oryza sativa GA 2-oxidase 5 (OsGA2ox5, was cloned and characterized. BLASTP analysis showed that OsGA2ox5 belongs to the C₂₀-GA2oxs subfamily, a subfamily of GA2oxs acting on C₂₀-GAs (GA₁₂, GA₅₃. Subcellular localization of OsGA2ox5-YFP in transiently transformed onion epidermal cells revealed the presence of this protein in both of the nucleus and cytoplasm. Real-time PCR analysis, along with GUS staining, revealed that OsGA2ox5 is expressed in the roots, culms, leaves, sheaths and panicles of rice. Rice plants overexpressing OsGA2ox5 exhibited dominant dwarf and GA-deficient phenotypes, with shorter stems and later development of reproductive organs than the wild type. The dwarfism phenotype was partially rescued by the application of exogenous GA3 at a concentration of 10 µM. Ectopic expression of OsGA2ox5 cDNA in Arabidopsis resulted in a similar phenotype. Real-time PCR assays revealed that both GA synthesis-related genes and GA signaling genes were expressed at higher levels in transgenic rice plants than in wild-type rice; OsGA3ox1, which encodes a key enzyme in the last step of the bioactive GAs synthesis pathway, was highly expressed in transgenic rice. The roots of OsGA2ox5-ox plants exhibited increased starch granule accumulation and gravity responses, revealing a role for GA in root starch granule development and gravity responses. Furthermore, rice and Arabidopsis plants overexpressing OsGA2ox5 were more resistant to high-salinity stress than wild-type plants. These results suggest that OsGA2ox5 plays important roles in GAs homeostasis, development, gravity responses and stress tolerance in rice.

Hexagonal OsB2: Sintering, microstructure and mechanical properties

International Nuclear Information System (INIS)

Xie, Zhilin; Lugovy, Mykola; Orlovskaya, Nina; Graule, Thomas; Kuebler, Jakob; Mueller, Martin; Gao, Huili; Radovic, Miladin; Cullen, David A.

2015-01-01

Highlights: • ReB 2 -type hexagonal OsB 2 powder has been densified by spark plasma sintering. • The sintered OsB 2 contains ∼80 wt.% hexagonal and ∼20 wt.% orthorhombic phases. • The average grain size of the sintered OsB 2 sample was 0.56 ± 0.26 μm. • H = 31 ± 9 GPa and E = 574 ± 112 GPa measured by nanoindentation. - Abstract: The metastable high pressure ReB 2 -type hexagonal OsB 2 bulk ceramics was produced by spark plasma sintering. The phase composition, microstructure, and mechanical behavior of the sintered OsB 2 were studied by X-ray diffraction, optical microscopy, TEM, SEM, EDS, and nanoindentation. The produced ceramics was rather porous and contained a mixture of hexagonal (∼80 wt.%) and orthorhombic (∼20 wt.%) phases as identified by X-ray diffraction and EBSD analysis. Two boron-rich phases, which do not contain Os, were also identified by TEM and SEM/EDS analysis. Nanoindentation measurements yielded a hardness of 31 ± 9 GPa and Young’s modulus of 574 ± 112 GPa, indicating that the material is rather hard and very stiff; however, it is very prone to crack formation and propagation, which is indicative of a very brittle nature of this material. Improvements in the sintering regime are required in order to produce dense, homogeneous and single phase hexagonal OsB 2 bulk ceramics

N-terminal nesprin-2 variants regulate β-catenin signalling

Energy Technology Data Exchange (ETDEWEB)

Zhang, Qiuping; Minaisah, Rose-Marie; Ferraro, Elisa; Li, Chen; Porter, Lauren J.; Zhou, Can; Gao, Fang; Zhang, Junyi; Rajgor, Dipen; Autore, Flavia; Shanahan, Catherine M.; Warren, Derek T., E-mail: derek.warren@kcl.ac.uk

2016-07-15

The spatial compartmentalisation of biochemical signalling pathways is essential for cell function. Nesprins are a multi-isomeric family of proteins that have emerged as signalling scaffolds, herein, we investigate the localisation and function of novel nesprin-2 N-terminal variants. We show that these nesprin-2 variants display cell specific distribution and reside in both the cytoplasm and nucleus. Immunofluorescence microscopy revealed that nesprin-2 N-terminal variants colocalised with β-catenin at cell-cell junctions in U2OS cells. Calcium switch assays demonstrated that nesprin-2 and β-catenin are lost from cell-cell junctions in low calcium conditions whereas emerin localisation at the NE remained unaltered, furthermore, an N-terminal fragment of nesprin-2 was sufficient for cell-cell junction localisation and interacted with β-catenin. Disruption of these N-terminal nesprin-2 variants, using siRNA depletion resulted in loss of β-catenin from cell-cell junctions, nuclear accumulation of active β-catenin and augmented β-catenin transcriptional activity. Importantly, we show that U2OS cells lack nesprin-2 giant, suggesting that the N-terminal nesprin-2 variants regulate β-catenin signalling independently of the NE. Together, these data identify N-terminal nesprin-2 variants as novel regulators of β-catenin signalling that tether β-catenin to cell-cell contacts to inhibit β-catenin transcriptional activity. - Highlights: • N-terminal nesprin-2 variants display cell specific expression patterns. • N-terminal spectrin repeats of nesprin-2 interact with β-catenin. • N-terminal nesprin-2 variants scaffold β-catenin at cell-cell junctions.. • Nesprin-2 variants play multiple roles in β-catenin signalling.

Novel high pressure hexagonal OsB2 by mechanochemistry

Science.gov (United States)

Xie, Zhilin; Graule, Moritz; Orlovskaya, Nina; Andrew Payzant, E.; Cullen, David A.; Blair, Richard G.

2014-07-01

Hexagonal OsB2, a theoretically predicted high-pressure phase, has been synthesized for the first time by a mechanochemical method, i.e., high energy ball milling. X-ray diffraction indicated that formation of hexagonal OsB2 begins after 2.5 h of milling, and the reaction reaches equilibrium after 18 h of milling. Rietveld refinement of the powder data indicated that hexagonal OsB2 crystallizes in the P63/mmc space group (No. 194) with lattice parameters of a=2.916 Å and c=7.376 Å. Transmission electron microscopy confirmed the appearance of the hexagonal OsB2 phase after high energy ball milling. in situ X-ray diffraction experiments showed that the phase is stable from -225 °C to 1050 °C. The hexagonal OsB2 powder was annealed at 1050 °C for 6 days in vacuo to improve crystallinity and remove strain induced during the mechanochemical synthesis. The structure partially converted to the orthorhombic phase (20 wt%) after fast current assisted sintering of hexagonal OsB2 at 1500 °C for 5 min. Mechanochemical approaches to the synthesis of hard boride materials allow new phases to be produced that cannot be prepared using conventional methods.

Novel high pressure hexagonal OsB{sub 2} by mechanochemistry

Energy Technology Data Exchange (ETDEWEB)

Xie, Zhilin; Graule, Moritz [Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, FL 32816 (United States); Orlovskaya, Nina, E-mail: Nina.Orlovskaya@ucf.edu [Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, FL 32816 (United States); Andrew Payzant, E. [Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831 (United States); Cullen, David A. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Blair, Richard G. [Department of Chemistry, University of Central Florida, Orlando, FL 32816 (United States)

2014-07-01

Hexagonal OsB{sub 2}, a theoretically predicted high-pressure phase, has been synthesized for the first time by a mechanochemical method, i.e., high energy ball milling. X-ray diffraction indicated that formation of hexagonal OsB{sub 2} begins after 2.5 h of milling, and the reaction reaches equilibrium after 18 h of milling. Rietveld refinement of the powder data indicated that hexagonal OsB{sub 2} crystallizes in the P63/mmc space group (No. 194) with lattice parameters of a=2.916 Å and c=7.376 Å. Transmission electron microscopy confirmed the appearance of the hexagonal OsB{sub 2} phase after high energy ball milling. in situ X-ray diffraction experiments showed that the phase is stable from −225 °C to 1050 °C. The hexagonal OsB{sub 2} powder was annealed at 1050 °C for 6 days in vacuo to improve crystallinity and remove strain induced during the mechanochemical synthesis. The structure partially converted to the orthorhombic phase (20 wt%) after fast current assisted sintering of hexagonal OsB{sub 2} at 1500 °C for 5 min. Mechanochemical approaches to the synthesis of hard boride materials allow new phases to be produced that cannot be prepared using conventional methods. - Graphical abstract: High resolution transmission electron micrograph of hexagonal OsB{sub 2} nanocrystallite with corresponding fast Fourier transform and simulated diffraction pattern. - Highlights: • Hexagonal OsB{sub 2} has been synthesized for the first time by mechanochemical method. • Hexagonal OsB{sub 2} crystallizes in P63/mmc space group (No. 194), a=2.916 Å and c=7.376 Å. • The hexagonal structure was confirmed by a transmission electron microscope. • No phase transformation was observed after being annealed at 1050 °C for 6 days. • 20 wt% of h-OsB{sub 2} was transformed to o-OsB{sub 2} after being sintered at 1500 °C for 5 min.

Stimulation by parathyroid hormone of sup 45 Ca sup 2+ uptake in osteoblast-like cells: Possible involvement of alkaline phosphatase

Energy Technology Data Exchange (ETDEWEB)

Fukayama, S.; Tashjian, A.H. Jr. (Harvard School of Public Health, Boston, MA (USA))

1990-04-01

We have investigated the actions of human PTH (hPTH-(1-34)) on the association of 45Ca2+ with two human (SaOS-2 and MG-63) and two rat (ROS 17/2.8 and UMR-106) osteoblast-like cell types. In SaOS-2 cells, hPTH-(1-34) binds to specific membrane receptors to activate adenylate cyclase. Treatment of SaOS-2 cells with hPTH-(1-34) resulted in an increase in 45Ca2+ uptake, in a dose-dependent fashion, up to 2- to 4-fold above control values. The increase was first evident at 10 min and persisted for at least 30 min. Treatment with nimodipine, a calcium channel antagonist, was without effect on the stimulatory action of PTH. A similar enhancement of cell-associated 45Ca2+ was observed when the cells were incubated with vasoactive intestinal peptide, which acts via different receptors to activate adenylate cyclase in SaOS-2 cells. Treatment with (Bu)2cAMP also induced an increase in cell-associated 45Ca2+. Pretreatment of SaOS-2 cells with hPTH-(1-34) for 4 h, which induced homologous desensitization to a second challenge with the same peptide for stimulation of cAMP production, did not attenuate the further enhancement of cell-associated 45Ca2+ by a second treatment with hPTH-(1-34). We then examined a possible relationship between alkaline phosphatase (ALPase) and 45Ca2+ uptake. SaOS-2 cells contained high levels of alkaline phosphatase activity and continuously released the enzyme into the medium. Release was enhanced by treatment with hPTH-(1-34) for 10 min. Incubation of cells with levamisole (an inhibitor of the liver/bone/kidney type of ALPase) resulted in a rapid decrease in basal and PTH-stimulated 45Ca2+ uptake, while treatment with L-Phe-Gly-Gly was without effect. Treatment of the cells with ALPase (bovine kidney) enhanced 45Ca2+ uptake. In MG-63 cells, a stimulatory effect of hPTH-(1-34) on cell-associated 45Ca2+ was also observed; however, hPTH-(1-34) did not stimulate cAMP production in MG-63 cells.

Determination of (187)Os in molybdenite by ICP-MS with neutron-induced (186)Os and (188)Os spikes.

Science.gov (United States)

Qu, W; Du, A; Zhao, D

2001-10-31

The article describes a method for the determination of (187)Os in molybdenite by isotope dilution inductively coupled plasma-mass spectrometry (ID-ICP-MS) with neutron-induced (186)Os and (188)Os spike. The spike used in the present work was prepared in line with the principle by which artificial nuclides are produced in a nuclear reaction. The concentration and isotopic composition of osmium in the prepared spike were evaluated accurately with the isotope dilution method, using negative thermal ion mass spectrometry (N-TIMS). The advantage of this method is that using (186)Os and (188)Os double spikes can effectively compensate for the mass discrimination effects of ICP-MS. Thus, the common correction practice for mass bias in the isotope dilution method with a single spike is unnecessary. In addition, the method enables one to reduce the determined error arising from instrumental instability. The precision for the (187)Os/((186)Os+(188)Os) ratio was approximately 2% (2sigma, RSD), but in the case of (187)Os/(186)Os, (187)Os/(188)Os and (186)Os/(188)Os, precision ranged from 2.0 to 8% (2sigma, RSD). The results for (187)Os concentration in a molybdenite sample determined with this method showed good agreement with reference values.

Real-time monitoring of cisplatin cytotoxicity on three-dimensional spheroid tumor cells

Directory of Open Access Journals (Sweden)

Baek NH

2016-07-01

Full Text Available NamHuk Baek,1,* Ok Won Seo,1,* Jaehwa Lee,1 John Hulme,2 Seong Soo A An2 1Department of Research and Development, NanoEntek Inc., Seoul, 2Department of BioNano Technology, Gachon University, Gyeonggi-do, Korea *These authors contributed equally to this work Abstract: Three-dimensional (3D cell cultivation is a powerful technique for monitoring and understanding diverse cellular mechanisms in developmental cancer and neuronal biology, tissue engineering, and drug development. 3D systems could relate better to in vivo models than two-dimensional (2D cultures. Several factors, such as cell type, survival rate, proliferation rate, and gene and protein expression patterns, determine whether a particular cell line can be adapted to a 3D system. The 3D system may overcome some of the limitations of 2D cultures in terms of cell–cell communication and cell networks, which are essential for understanding differentiation, structural organization, shape, and extended connections with other cells or organs. Here, the effect of the anticancer drug cisplatin, also known as cis-diamminedichloroplatinum (II or CDDP, on adenosine triphosphate (ATP generation was investigated using 3D spheroid-forming cells and real-time monitoring for 7 days. First, 12 cell lines were screened for their ability to form 3D spheroids: prostate (DU145, testis (F9, embryonic fibroblast (NIH-3T3, muscle (C2C12, embryonic kidney (293T, neuroblastoma (SH-SY5Y, adenocarcinomic alveolar basal epithelial cell (A549, cervical cancer (HeLa, HeLa contaminant (HEp2, pituitary epithelial-like cell (GH3, embryonic cell (PA317, and osteosarcoma (U-2OS cells. Of these, eight cell lines were selected: NIH-3T3, C2C12, 293T, SH-SY5Y, A549, HeLa, PA317, and U-2OS; and five underwent real-time monitoring of CDDP cytotoxicity: HeLa, A549, 293T, SH-SY5Y, and U-2OS. ATP generation was blocked 1 day after addition of 50 µM CDDP, but cytotoxicity in HeLa, A549, SH-SY5Y, and U-2OS cells could be

Role of Spm-Cer-S1P signalling pathway in MMP-2 mediated U46619-induced proliferation of pulmonary artery smooth muscle cells: protective role of epigallocatechin-3-gallate.

Science.gov (United States)

Chowdhury, Animesh; Sarkar, Jaganmay; Chakraborti, Tapati; Chakraborti, Sajal

2015-10-01

During remodelling of pulmonary artery, marked proliferation of pulmonary artery smooth muscle cells (PASMCs) occurs, which contributes to pulmonary hypertension. Thromboxane A2 (TxA2) has been shown to produce pulmonary hypertension. The present study investigates the inhibitory effect of epigallocatechin-3-gallate (EGCG) on the TxA2 mimetic, U46619-induced proliferation of PASMCs. U46619 at a concentration of 10 nM induces maximum proliferation of bovine PASMCs. Both pharmacological and genetic inhibitors of p(38)MAPK, NF-κB and MMP-2 significantly inhibit U46619-induced cell proliferation. EGCG markedly abrogate U46619-induced p(38)MAPK phosphorylation, NF-κB activation, proMMP-2 expression and activation, and also the cell proliferation. U46619 causes an increase in the activation of sphingomyelinase (SMase) and sphingosine kinase (SPHK) and also increase sphingosine 1 phosphate (S1P) level. U46619 also induces phosphorylation of ERK1/2, which phosphorylates SPHK leading to an increase in S1P level. Both pharmacological and genetic inhibitors of SMase and SPHK markedly inhibit U46619-induced cell proliferation. Additionally, pharmacological and genetic inhibitors of MMP-2 markedly abrogate U46619-induced SMase activity and S1P level. EGCG markedly inhibit U46619-induced SMase activity, ERK1/2 and SPHK phosphorylation and S1P level in the cells. Overall, Sphingomyeline-Ceramide-Sphingosine-1-phosphate (Spm-Cer-S1P) signalling axis plays an important role in MMP-2 mediated U46619-induced proliferation of PASMCs. Importantly, EGCG inhibits U46619 induced increase in MMP-2 activation by modulating p(38)MAPK-NFκB pathway and subsequently prevents the cell proliferation. Copyright © 2015 John Wiley & Sons, Ltd.

Bacterial biofilm formation versus mammalian cell growth on titanium-based mono- and bi-functional coating

Directory of Open Access Journals (Sweden)

G Subbiahdoss

2010-05-01

Full Text Available Biomaterials-associated-infections (BAI are serious complications in modern medicine. Although non-adhesive coatings, like polymer-brush coatings, have been shown to prevent bacterial adhesion, they do not support cell growth. Bi-functional coatings are supposed to prevent biofilm formation while supporting tissue integration. Here, bacterial and cellular responses to poly(ethylene glycol (PEG brush-coatings on titanium oxide presenting the integrin-active peptide RGD (arginine-glycine-aspartic acid (bioactive “PEG-RGD” were compared to mono-functional PEG brush-coatings (biopassive “PEG” and bare titanium oxide (TiO2 surfaces under flow. Staphylococcus epidermidis ATCC 35983 was deposited on the surfaces under a shear rate of 11 s-1 for 2 h followed by seeding of U2OS osteoblasts. Subsequently, both S. epidermidis and U2OS cells were grown simultaneously on the surfaces for 48 h under low shear (0.14 s-1. After 2 h, staphylococcal adhesion was reduced to 3.6±1.8 × 103 and 6.0±3.9 × 103 cm-2 on PEG and PEG-RGD coatings respectively, compared to 1.3±0.4 × 105 cm-2 for the TiO2 surface. When allowed to grow for 48 h, biofilms formed on all surfaces. However, biofilms detached from the PEG and PEG-RGD coatings when exposed to an elevated shear (5.6 s-1 U2OS cells neither adhered nor spread on PEG brush-coatings, regardless of the presence of biofilm. In contrast, in the presence of biofilm, U2OS cells adhered and spread on PEG-RGD coatings with a significantly higher surface coverage than on bare TiO2. The detachment of biofilm and the high cell surface coverage revealed the potential significance of PEG-RGD coatings in the context of the “race for the surface” between bacteria and mammalian cells.

Yeast endoribonuclease stimulated by Novikoff Hepatoma small nuclear RNAS U1 and U2

International Nuclear Information System (INIS)

Stevens, A.

1982-01-01

Using [ 3 H]m 7 Gppp[ 14 C]RNA-poly(A) from yeast as a substrate, an endoribonuclease has been detected in enzyme fractions derived from a high salt wash of ribonucleoprotein particles of Saccharomyces cerevisiae. The [ 3 H]m 7 Gppp[ 14 C]RNA-poly(A) seems to be a preferred substrate since other polyribonucleotides are hydrolyzed more slowly, if at all. The enzyme is inhibited by ethidium bromide, but fully double-stranded polyribonucleotides are not hydrolyzed. The hydrolysis of [ 3 H]m 7 Gppp[ 14 C]RNA-poly(A) is stimulated about 2.5-fold by the addition of small nuclear RNAs U1 and U2 of Novikoff hepatoma cells. Results show that the stimulation involves an interaction of the labeled RNA with the small nuclear RNA

OsLOL1, a C2C2-type zinc finger protein, interacts with OsbZIP58 to promote seed germination through the modulation of gibberellin biosynthesis in Oryza sativa.

Science.gov (United States)

Wu, Jiahe; Zhu, Chuanfeng; Pang, Jinhuan; Zhang, Xiangrong; Yang, Chunlin; Xia, Guixian; Tian, Yingchuan; He, Chaozu

2014-12-01

Seed germination is a key developmental process in the plant life cycle that is influenced by various environmental cues and phytohormones through gene expression and a series of metabolism pathways. In the present study, we investigated a C2C2-type finger protein, OsLOL1, which promotes gibberellin (GA) biosynthesis and affects seed germination in Oryza sativa (rice). We used OsLOL1 antisense and sense transgenic lines to explore OsLOL1 functions. Seed germination timing in antisense plants was restored to wild type when exogenous GA3 was applied. The reduced expression of the GA biosynthesis gene OsKO2 and the accumulation of ent-kaurene were observed during germination in antisense plants. Based on yeast two-hybrid and firefly luciferase complementation analyses, OsLOL1 interacted with the basic leucine zipper protein OsbZIP58. The results from electrophoretic mobility shift and dual-luciferase reporter assays showed that OsbZIP58 binds the G-box cis-element of the OsKO2 promoter and activates LUC reporter gene expression, and that interaction between OsLOL1 and OsbZIP58 activates OsKO2 gene expression. In addition, OsLOL1 decreased SOD1 gene expression and accelerated programmed cell death (PCD) in the aleurone layer of rice grains. These findings demonstrate that the interaction between OsLOL1 and OsbZIP58 influences GA biosynthesis through the activation of OsKO2 via OsbZIP58, thereby stimulating aleurone PCD and seed germination. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

Evolution of metastable state molecules N2(A3Σu+) in a nanosecond pulsed discharge: A particle-in-cell/Monte Carlo collisions simulation

International Nuclear Information System (INIS)

Gao Liang; Sun Jizhong; Feng Chunlei; Bai Jing; Ding Hongbin

2012-01-01

A particle-in-cell plus Monte Carlo collisions method has been employed to investigate the nitrogen discharge driven by a nanosecond pulse power source. To assess whether the production of the metastable state N 2 (A 3 Σ u + ) can be efficiently enhanced in a nanosecond pulsed discharge, the evolutions of metastable state N 2 (A 3 Σ u + ) density and electron energy distribution function have been examined in detail. The simulation results indicate that the ultra short pulse can modulate the electron energy effectively: during the early pulse-on time, high energy electrons give rise to quick electron avalanche and rapid growth of the metastable state N 2 (A 3 Σ u + ) density. It is estimated that for a single pulse with amplitude of -9 kV and pulse width 30 ns, the metastable state N 2 (A 3 Σ u + ) density can achieve a value in the order of 10 9 cm -3 . The N 2 (A 3 Σ u + ) density at such a value could be easily detected by laser-based experimental methods.

Evolution of metastable state molecules N2(A3 Σu+) in a nanosecond pulsed discharge: A particle-in-cell/Monte Carlo collisions simulation

Science.gov (United States)

Gao, Liang; Sun, Jizhong; Feng, Chunlei; Bai, Jing; Ding, Hongbin

2012-01-01

A particle-in-cell plus Monte Carlo collisions method has been employed to investigate the nitrogen discharge driven by a nanosecond pulse power source. To assess whether the production of the metastable state N2(A3 Σu+) can be efficiently enhanced in a nanosecond pulsed discharge, the evolutions of metastable state N2(A3 Σu+) density and electron energy distribution function have been examined in detail. The simulation results indicate that the ultra short pulse can modulate the electron energy effectively: during the early pulse-on time, high energy electrons give rise to quick electron avalanche and rapid growth of the metastable state N2(A3 Σu+) density. It is estimated that for a single pulse with amplitude of -9 kV and pulse width 30 ns, the metastable state N2(A3 Σu+) density can achieve a value in the order of 109 cm-3. The N2(A3 Σu+) density at such a value could be easily detected by laser-based experimental methods.

Electronic structures of three semiconducting intermetallics: RuAl sub 2 , RuGa sub 2 and OsAl sub 2

CERN Document Server

Springborg, M

1998-01-01

Results of first-principles, density-functional, LMTO-ASA calculations on the closely related C11, C40, and C54 structures of the three title compounds are reported. Only for OsAl sub 2 in the C11 structure were the structural degrees of freedom optimized; this gave results in good agreement with experimental values. On the other hand, the calculations were not capable of reproducing the correct relative stability of the different structures; this was ascribed to the atomic-sphere approximation. All of the compounds were found to be small-gap semiconductors with, however, a slightly larger gap for OsAl sub 2. The occurrence of a gap at the Fermi level is mainly due to hybridization between d functions of Os or Ru and p functions of Al or Ga, but, in particular for OsAl sub 2 , charge-transfer effects can also be considered to be responsible for the occurrence of a gap. Several flat bands just above the Fermi level lead to a corresponding high density of states there, but also to low carrier velocities. As a b...

A new synthesis route for Os-complex modified redox polymers for potential biofuel cell applications.

Science.gov (United States)

Pöller, Sascha; Beyl, Yvonne; Vivekananthan, Jeevanthi; Guschin, Dmitrii A; Schuhmann, Wolfgang

2012-10-01

A new synthesis route for Os-complex modified redox polymers was developed. Instead of ligand exchange reactions for coordinative binding of suitable precursor Os-complexes at the polymer, Os-complexes already exhibiting the final ligand shell containing a suitable functional group were bound to the polymer via an epoxide opening reaction. By separation of the polymer synthesis from the ligand exchange reaction at the Os-complex, the modification of the same polymer backbone with different Os-complexes or the binding of the same Os-complex to a number of different polymer backbones becomes feasible. In addition, the Os-complex can be purified and characterized prior to its binding to the polymer. In order to further understand and optimize suitable enzyme/redox polymer systems concerning their potential application in biosensors or biofuel cells, a series of redox polymers was synthesized and used as immobilization matrix for Trametes hirsuta laccase. The properties of the obtained biofuel cell cathodes were compared with similar biocatalytic interfaces derived from redox polymers obtained via ligand exchange reaction of the parent Os-complex with a ligand integrated into the polymer backbone during the polymer synthesis. Copyright © 2011 Elsevier B.V. All rights reserved.

Superconducting and normal-state properties of the layered boride OsB2

Science.gov (United States)

Singh, Yogesh; Niazi, A.; Vannette, M. D.; Prozorov, R.; Johnston, D. C.

2007-12-01

OsB2 crystallizes in an orthorhombic structure (Pmmn) which contains alternate boron and osmium layers stacked along the c axis. The boron layers consist of puckered hexagons as opposed to the flat graphite-like boron layers in MgB2 . OsB2 is reported to become superconducting below 2.1K . We report results of the dynamic and static magnetic susceptibilities, electrical resistivity, Hall effect, heat capacity, and penetration depth measurements on arc-melted polycrystalline samples of OsB2 to characterize its superconducting and normal-state properties. These measurements confirmed that OsB2 becomes a bulk superconductor below Tc=2.1K . Our results indicate that OsB2 is a moderate-coupling type-II superconductor with an electron-phonon coupling constant λep≈0.4-0.5 , a small Ginzburg-Landau parameter κ˜1-2 , and an upper critical magnetic field Hc2(0.5K)˜420Oe for an unannealed sample and Hc2(1K)˜330Oe for an annealed sample. The temperature dependence of the superfluid density ns(T) for the unannealed sample is consistent with an s -wave superconductor with a slightly enhanced zero temperature gap Δ(0)=1.9kBTc and a zero temperature London penetration depth λ(0)=0.38(2)μm . The ns(T) data for the annealed sample show deviations from the predictions of the single-band s -wave BCS model. The magnetic, transport, and thermal properties in the normal state of isostructural and isoelectronic RuB2 , which is reported to become superconducting below 1.6K , are also reported.

[RITA combined with temozolomide inhibits the proliferation of human glioblastoma U87 cells].

Science.gov (United States)

He, Xiao-Yan; Feng, Xiao-Li; Song, Xin-Pei; Zeng, Huan-Chao; Cao, Zhong-Xu; Xiao, Wei-Wei; Zhang, Bao; Wu, Qing-Hua

2016-10-20

To observe the effect of RITA, a small molecule that targets p53, combined with temozolomide (TMZ) on proliferation, colony formation and apoptosis of human glioblastoma U87 cells and explore the underlying mechanism. Cultured U87 cells were treated with RITA (1, 5, 10, 20 µmol/L), TMZ, or RITA+TMZ (half dose) for 24, 48 or 72 h. MTS assay were used to detect the cell proliferation, and the cell proliferation rate and inhibitory rate were calculated. The effect of combined treatments was evaluated by the q value. The expressions of p53, p21 and other apoptosis-associated genes were detected by qRT-PCR and Western blotting; cell apoptosis was assayed using flow cytometry with Annexin V/PI double staining; colony formation of the cells was detected with crystal violet staining. MTS assay showed that RITA at the 4 doses more potently inhibited U87 cell viability than TMZ at 72 h (P=0.000) with inhibitory rates of 25.94%-41.38% and 3.84%-8.20%, respectively. RITA combined with TMZ caused a more significant inhibition of U87 cells (29.21%-52.11%) than RITA (PRITA+TMZ for 48 h resulted in q values exceeding 1.2 and showed an obvious synergistic effect of the drugs. Both RITA and TMZ, especially the latter, significantly increased the expressions of p53, p21, puma, and other apoptosis-associated genes to accelerate apoptosis and inhibit the growth and colony formation of U87 cells, and the effect was more obvious with a combined treatment. RITA inhibits the growth of human glioblastoma cells and enhance their sensitivity to TMZ by up-regulating p53 expression, and when combined, RITA and TMZ show a synergistic effect to cause a stronger cell inhibition.

PPADS: an antagonist at endothelial P2Y-purinoceptors but not P2U-purinoceptors.

Science.gov (United States)

Brown, C; Tanna, B; Boarder, M R

1995-11-01

1. Bovine aortic endothelial (BAE) cells contain two co-existing receptors for extracellular ATP, the P2Y and P2U-purinoceptors. Here we have determined whether the proposed P2X-purinoceptor antagonist, pyridoxalphosphate-6-azophenyl-2', 4'-disulphonic acid (PPADS) could distinguish between these two receptor subtypes. 2. Cells labelled with myo-[2-3H]-inositol were stimulated with increasing concentrations of either the P2Y-agonist, 2MeSATP, or the P2U-agonist, UTP in the absence or presence of 30 microM PPADS. The accumulation of total [3H]-inositol (poly)phosphates mediated by 2MeSATP was markedly attenuated by PPADS, whereas the response to UTP was not significantly affected. 3. Stimulation of BAE cells with increasing concentrations of ATP showed a reduced response in the presence of 10 microM PPADS, but this effect of the antagonist was not significant. By contrast, inhibition of the response to ADP was profound and highly significant. 4. These observations show that PPADS is not a selective P2X-purinoceptor antagonist, but is able to distinguish between P2Y- and P2YU-purinoceptors in BAE cells, and indicate that this compound may provide a useful tool in the study of multiple subtypes of P2-purinoceptors. Furthermore the results are consistent with the hypothesis that ATP interacts with both receptor subtypes, but that the action of ADP is primarily at the P2Y-purinoceptor in these endothelial cells.

Regulation of SUMO2 Target Proteins by the Proteasome in Human Cells Exposed to Replication Stress

DEFF Research Database (Denmark)

Bursomanno, Sara; McGouran, Joanna F; Kessler, Benedikt M

2015-01-01

In human cells, SUMO2 is predominantly conjugated to target proteins in response to cellular stress. Previous studies suggested that proteins conjugated to SUMO2, but not to SUMO1, could be regulated by the ubiquitin-mediated proteasome system. Hence, we set out to understand the role...... of the proteasome in determining the fate of proteins conjugated to SUMO2 when cells are treated with DNA replication stress conditions. We conducted a quantitative proteomic analysis in a U2OS cell line stably expressing SUMO2(Q87R) tagged with StrepHA in the presence or absence of epoxomicin (EPOX), a proteasome...... inhibitor. We identified subgroups of putative SUMO2 targets that were either degraded or stabilized by EPOX upon SUMO2 conjugation in response to replication stress. Interestingly, the subgroup of proteins degraded upon SUMO2 conjugation was enriched in proteins playing roles in DNA damage repair...

Cervical Cancer Cell Supernatants Induce a Phenotypic Switch from U937-Derived Macrophage-Activated M1 State into M2-Like Suppressor Phenotype with Change in Toll-Like Receptor Profile

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Karina Sánchez-Reyes

2014-01-01

Full Text Available Cervical cancer (CC is the second most common cancer among women worldwide. Infection with human papillomavirus (HPV is the main risk factor for developing CC. Macrophages are important immune effector cells; they can be differentiated into two phenotypes, identified as M1 (classically activated and M2 (alternatively activated. Macrophage polarization exerts profound effects on the Toll-like receptor (TLR profile. In this study, we evaluated whether the supernatant of human CC cells HeLa, SiHa, and C-33A induces a shift of M1 macrophage toward M2 macrophage in U937-derived macrophages. Results. The results showed that soluble factors secreted by CC cells induce a change in the immunophenotype of macrophages from macrophage M1 into macrophage M2. U937-derived macrophages M1 released proinflammatory cytokines and nitric oxide; however, when these cells were treated with the supernatant of CC cell lines, we observed a turnover of M1 toward M2. These cells increased CD163 and IL-10 expression. The expression of TLR-3, -7, and -9 is increased when the macrophages were treated with the supernatant of CC cells. Conclusions. Our result strongly suggests that CC cells may, through the secretion of soluble factors, induce a change of immunophenotype M1 into M2 macrophages.

Estradiol attenuates EGF-induced rapid uPAR mobilization and cell migration via the G-protein-coupled receptor 30 in ovarian cancer cells

DEFF Research Database (Denmark)

Henic, Emir; Noskova, Vera; Høyer-Hansen, Gunilla

2009-01-01

: rapid mobilization of uPAR from detergent-resistant domains, increased mRNA, and decreased degradation. G-protein-coupled receptor 30 (GPR30) is a newly identified membrane estrogen receptor (ER).The objective of this study was to explore the effects of 17beta-estradiol (E(2)) on uPAR expression...... for ERalpha, and quantitative polymerase chain reaction. Estradiol attenuates the stimulatory effect of EGF on cell migration and uPAR expression. Specifically, E(2) reduces the very rapid increase of detergent extractable uPAR, which occurs within minutes of EGF stimulation and probably represents...... agonist G1, mimicked the effect of E(2) on uPAR expression and cell migration. OVCAR-3 cells express mRNA for GPR30.Estradiol attenuates EGF-induced mobilization of ligated uPAR from detergent-resistant domains and subsequent migration in ovarian cancer cells. The response to various ER ligands indicates...

Crystal structure of strontium osmate (8) Sr[OsO5(H2O)]x3H2O

International Nuclear Information System (INIS)

Nevskij, N.N; Ivanov-Ehmin, B.N.; Nevskaya, N.A.; Belov, N.V.; AN SSSR, Moscow. Inst. Kristallografii)

1982-01-01

Crystal structure of the Sr[OsO 5 (H 2 O)]x3H 2 O complex is studied. Rhombic P-cell has the parameters: a=6.426(1), b=7.888(1), c=14.377(5) A, Vsub(c)=729 A 3 . The R-factor equals 0.034. The coordinates of the basis atoms and isotropic temperature corrections, as well as basic interatomic distances, are determined

Small Molecule Protection of Bone Marrow Hematopoietic Stem Cells

Science.gov (United States)

2016-10-01

human CD34+ cells Determine formaldehyde dose-dependent survival on FANCG-deficient/control CD34+ cells in culture 9 - 15 Dr. Monnat – 4...molecule provides aldehyde dose-dependent protection in human cells in culture . Next steps: In the next award period we will: - extend above...U2-OS human osteosarcoma cells (Expt. 2) that were either untransduced (untx), transduced with and expressing a scrambled shRNA (shCTR), or

Preclinical Testing of an Oncolytic Parvovirus: Standard Protoparvovirus H-1PV Efficiently Induces Osteosarcoma Cell Lysis In Vitro

OpenAIRE

Carsten Geiss; Zoltán Kis; Barbara Leuchs; Monika Frank-Stöhr; Jörg R. Schlehofer; Jean Rommelaere; Christiane Dinsart; Jeannine Lacroix

2017-01-01

Osteosarcoma is the most frequent malignant disease of the bone. On the basis of early clinical experience in the 1960s with H-1 protoparvovirus (H-1PV) in osteosarcoma patients, this effective oncolytic virus was selected for systematic preclinical testing on various osteosarcoma cell cultures. A panel of five human osteosarcoma cell lines (CAL 72, H-OS, MG-63, SaOS-2, U-2OS) was tested. Virus oncoselectivity was confirmed by infecting non-malignant human neonatal fibroblasts and osteoblasts...

Synthesis and structure of [(NH2)2CSSC(NH2)2]2[OsBr6]Br2 . 3H2O

International Nuclear Information System (INIS)

Rudnitskaya, O. V.; Kultyshkina, E. K.; Stash, A. I.; Glukhova, A. A.; Venskovskii, N. U.

2008-01-01

The complex [(NH 2 ) 2 CSSC(NH 2 ) 2 ] 2 [OsBr 6 ]Br 2 . 3H 2 O is synthesized by the reaction of K 2 OsBr 6 with thiocarbamide in concentrated HBr and characterized using electronic absorption and IR absorption spectroscopy. Its crystal structure is determined by X-ray diffraction. The crystals are orthorhombic, a = 11.730(2) A, b = 14.052(3) A, c = 16.994(3) A, space group Cmcm, and Z = 4. The [OsBr 6 ] 2- anionic complex has an octahedral structure. The Os-Br distances fall in the range 2.483-2.490 A. The α,α'-dithiobisformamidinium cation is a product of the oxidation of thiocarbamide. The S-S and C-S distances are 2.016 and 1.784 A, respectively. The H 2 O molecules, Br - ions, and NH 2 groups of the cation are linked by hydrogen bonds.

Radiosensitization and relative mechanisms of vanillin derivative BVAN08 on human glioma U-251 cells

International Nuclear Information System (INIS)

Wang Shubin; Zhang Bo; Sun Weijian; Wang Yu; Liu Xiaodan; Xu Qinzhi; Zhou Pingkun

2010-01-01

Objective: To provide more convincing evidences and experimental data for exploring vanillin derivative BVAN08, 6-bromine-5-hydroxy-4-methoxy-benzaldehyde, as a new anticancer drug, and to investigate the effect on the growth, radiosensitization of human glioma cell line U-251 and the relative mechanism. Methods: The effect of BVAN08 on cell proliferation of U-251 and radiosensitivity to 60 Co γ-rays (irradiation dose rate 2.3 Gy/min) were analyzed with MTT and colony-forming ability assay. Change in cellular morphology was observed by using light microscope. Change in cell cycle and apoptosis was detected with flow cytometry. The autophagy was observed by using TEM (irradiation dose rate is transmission electron microscope). DNA-PKcs protein level was detected through Western blot analysis. Results: BVAN08 exhibited a dose- and time-dependent inhibition on the proliferation of U-251 cells during the concentration range of 10-100 mol/L (t=1.83-3.07, P 50 at 48 h and 72 h after administration with BVAN08 were 55.3 and 52.7 mol/L, respectively. Obvious G 2 /M arrest was induced in U-251 cells after 4 h administration with BVAN08, and reached peck at 12 h. The G 2 /M population reached 63.3% in U-251 cells after 12 h administration of 60 μmol/L BVAN08 and kept increasing with the time, while both apoptosis and autophagic cell death were induced. The most effective radiosensitization time for BVAN08 treatment was 12 h before irradiation. The enhancement ratio of radiosensitivity was 3.14 for 20 μmol/L of BVAN08 12 h before 2 Gy irradiation. Conclusions: BVAN08 can induce apoptosis as radiosensitizing effect might be associated with the induction of G 2 /M arrest and inhibition of DNA-PKcs expression. BVAN08 seemed to be a promising radiosensitizing anticancer drug. (authors)

A yeast endoribonuclease stimulated by Novikoff hepatoma small nuclear RNAs U1 and U2

International Nuclear Information System (INIS)

Stevens, A.

1982-01-01

Using [ 3 H]m 7 Gppp[ 14 C]RNA-poly(A) from yeast as a substrate, an endoribonuclease has been detected in enzyme fractions derived from a high salt wash of ribonucleoprotein particles of Saccharomyces cerevisiae. The [ 3 H]m 7 Gppp[ 14 C]RNA-poly(A) seems to be a preferred substrate since other polyribonucleotides are hydrolyzed more slowly, if at all. The enzyme is inhibited by ethidium bromide, but fully double-stranded polyribonucleotides are not hydrolyzed. The hydrolysis of [ 3 H]m 7 Gppp[ 14 C]RNA-poly(A) is stimulated about 2.5-fold by the addition of small nuclear RNAs U1 and U2 of Novikoff hepatoma cells. Results show that the stimulation involves an interaction of the labeled RNA with the small nuclear RNA

Naja nigricollis CMS-9 enhances the mitochondria-mediated death pathway in adaphostin-treated human leukaemia U937 cells.

Science.gov (United States)

Chen, Ying-Jung; Wang, Jeh-Jeng; Chang, Long-Sen

2011-11-01

1. The aim of the present study was to explore the effect of the Naja nigricollis phospholipase A(2) CMS-9 on adaphostin-induced death of human leukaemia U937 cells. 2. Leukaemia U937 cells (Bcr/Abl-negative cells) were treated with adaphostin (0-10 μmol/L) and CMS-9 (0-1 μmol/L). The effects of CMS-9, adaphostin and their combination on cell viability, the generation reactive oxygen species (ROS), [Ca(2+) ](i) , p38 mitogen-activated protein kinase (MAPK) activation, Akt and extracellular signal-regulated kinase (ERK) inactivation, mitochondrial membrane potential (ΔΨ(m) ) and Bcl-2 family proteins were analysed. 3. Both adaphostin and CMS-9 induced U937 cell apoptosis, characterized by dissipation of ΔΨ(m) and ROS generation. Combined treatment further increased ΔΨ(m) loss and reduced the viability of adaphostin-treated cells. Unlike in CMS-9-treated cells, in adaphostin-treated cells ROS-induced increases in [Ca(2+) ](i) were observed. CMS-9-induced ROS generation resulted in p38 MAPK activation, whereas adaphostin treatment elicited ROS/Ca(2+) -mediated inactivation of Akt and ERK. Moreover, Akt was found to be involved in ERK phosphorylation. Suppression of p38 MAPK activation blocked CMS-9-induced ΔΨ(m) loss and Bcl-xL downregulation. Overexpression of constitutively active Akt and mitogen-activated protein kinase kinase (MEK) 1 rescued adaphostin-induced ΔΨ(m) loss and Bcl-2 downregulation. Similarly, CMS-9 augmented adaphostin toxicity in human leukaemia K562 cells via increased mitochondrial alterations. 4. The results suggest that two distinct pathways mediate adaphostin- and CMS-9-induced mitochondrial damage (i.e. the ROS-Ca(2+) -Akt-ERK and ROS-p38 MAPK pathways, respectively). These distinct pathway explain the augmentation by CMS-9 of ΔΨ(m) loss and apoptosis in adaphostin-treated U937 cells. © 2011 The Authors. Clinical and Experimental Pharmacology and Physiology © 2011 Blackwell Publishing Asia Pty Ltd.

Profilaktyka cukrzycy typu 2 w grupie osób starszych = Type 2 diabetes prevention among elderly people

Directory of Open Access Journals (Sweden)

Anna Mirczak

2016-12-01

Cukrzyca typu 2 jest poważną chorobą przewlekłą występującą powszechnie w grupie osób starszych. Późna diagnoza oraz niewłaściwe leczenie prowadzi do poważnych  powikłań takich jak choroby układu krążenia, neuropatia, zespół stopy cukrzycowej i amputacji, niewydolność nerek oraz ślepota, których leczenie jest bardzo kosztowne. Cukrzyca typu 2 jest uwarunkowana czynnikami genetycznymi oraz środowiskowymi (niewłaściwy styl życia. Coraz powszechniejsze wstępowanie cukrzycy w społeczeństwie wynika jednak głównie z nadwagi, otyłości brzusznej oraz niskiej aktywności fizycznej. Badania pokazują, że poprzez modyfikacje stylu życia (dieta, aktywność fizyczna można opóźniać i zapobiegać występowaniu cukrzycy w grypach ryzyka. W tym procesie niezwykle ważne są trzypoziomowe działania profilaktyczne. Profilaktyka pierwszej fazy oznacza zapobieganie cukrzycy poprzez zmianę stylu życia u osób zdrowych, profilaktyka drugiej fazy to zapobieganie występowaniu powikłaniom cukrzycy u osób z grupy ryzyka, natomiast profilaktyka trzeciorzędowa skierowana jest do osób chorych i polega na wczesnym wykrywaniu i odpowiednim leczeniu powikłań cukrzycy. Jednakże, pomimo iż cukrzyca jest chorobą często występującą wśród seniorów, wciąż brakuje badań klinicznych dotyczących specyfiki leczenia w tej grupie wiekowe, jak również doniesień na temat działań prewencyjnych. Celem pracy było przedstawienie zasad profilaktyki cukrzycy w grupie osób starszych na podstawie analizy dostępnej literatury. Dotychczasowe badania wskazują, że skuteczną metodą profilaktyki cukrzycy wśród seniorów jest optymalizacja poziomu glukozy we krwi poprzez zdrową dietę, aktywność fizyczną, kontrolę wartości trójglicerydów i ciśnienia tętniczego krwi, zmniejszenie masy ciała i unikanie używek.   Abstract Type 2 diabetes is one of the most common chronic diseases among the elderly and is also a very serious health

Kondo Effect of U Impurities in Dilute (YU)2Zn17

Science.gov (United States)

Takagi, Shigeru; Suzuki, Hiroyuki; Anzai, Kousuke

2001-10-01

Extending previous work on single-site properties of U ions in (LaU)2Zn17, we have investigated, from ρ(T), χ(T) and Cp(T) on single crystals, (Y1-xUx)2Zn17 with x=0.025 and 0.050, which has almost the same unit-cell volume as an antiferromagnetic heavy-electron compound U2Zn17. Remarkable features in the dilute-impurity limit have been clarified, which include Kondo behavior of ρ(T), large and almost isotropic χimp(T), and strongly enhanced Cimp(T)/T with gigantic γimp=2.02 2.05 J/K2·mole-U as T→0 due to a low characteristic energy-scale of the system. It is shown that gross features of the data are explained in terms of the conventional Kondo effect in the presence of the crystal field with the U3+ \\varGamma6 doublet ground state. It is also shown that the variation of γ with the unit-cell volume in related systems is not explained as a volume effect on TK and that even the behavior of fictitious “paramagnetic” U2Zn17 is not described as a collection of U impurities in dilute (YU)2Zn17.

Knockdown of NF-E2-related factor 2 inhibits the proliferation and growth of U251MG human glioma cells in a mouse xenograft model.

Science.gov (United States)

Ji, Xiang-Jun; Chen, Sui-Hua; Zhu, Lin; Pan, Hao; Zhou, Yuan; Li, Wei; You, Wan-Chun; Gao, Chao-Chao; Zhu, Jian-Hong; Jiang, Kuan; Wang, Han-Dong

2013-07-01

NF-E2-related factor 2 (Nrf2) is a pivotal transcription factor of cellular responses to oxidative stress and recent evidence suggests that Nrf2 plays an important role in cancer pathobiology. However, the underlying mechanism has yet to be elucidated, particularly in glioma. In the present study, we investigated the role of Nrf2 in the clinical prognosis, cell proliferation and tumor growth of human glioblastoma multiforme (GBM). We detected overexpression of Nrf2 protein levels in GBM compared to normal brain tissues. Notably, higher protein levels of Nrf2 were significantly associated with poorer overall survival and 1-year survival for GBM patients. Furthermore, we constructed the plasmid Si-Nrf2 and transduced it into U251MG cells to downregulate the expression of Nrf2 and established stable Nrf2 knockdown cells. The downregulation of Nrf2 suppressed cell proliferation in vitro and tumor growth in mouse xenograft models. We performed immunohistochemistry staining to detect the protein levels of Nrf2, Ki-67, caspase-3 and CD31 in the xenograft tumors and found that the expression levels of Nrf2 and Ki-67 were much lower in the Si-Nrf2 group compared to the Si-control group. In addition, the number of caspase-3-positive cells was significantly increased in the Si-Nrf2 group. By analysis of microvessel density (MVD) assessed by CD31, the MVD value in the Si-Nrf2 group decreased significantly compared to the Si-control group. These findings indicate that the knockdown of Nrf2 may suppress tumor growth by inhibiting cell proliferation, increasing cell apoptosis and inhibiting angiogenesis. These results highlight the potential of Nrf2 as a candidate molecular target to control GBM cell proliferation and tumor growth.

Structural and electronic properties of OsB2 : A hard metallic material

Science.gov (United States)

Chen, Z. Y.; Xiang, H. J.; Yang, Jinlong; Hou, J. G.; Zhu, Qingshi

2006-07-01

We calculate the structural and electronic properties of OsB2 using density functional theory with or without taking into account the spin-orbit (SO) interaction. Our results show that the bulk modulus with and without SO interactions are 364 and 365GPa , respectively, both are in good agreement with experiment (365-395GPa) . The evidence of covalent bonding of Os-B, which plays an important role to form a hard material, is indicated both in charge density, atoms in molecules analysis, and density of states analysis. The good metallicity and hardness of OsB2 might suggest its potential application as hard conductors.

Hexagonal OsB{sub 2}: Sintering, microstructure and mechanical properties

Energy Technology Data Exchange (ETDEWEB)

Xie, Zhilin [Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, FL 32816 (United States); Lugovy, Mykola [Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, FL 32816 (United States); Institute for Problems of Materials Science, 3 Krzhizhanivskii Str., Kyiv 03142 (Ukraine); Orlovskaya, Nina, E-mail: Nina.Orlovskaya@ucf.edu [Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, FL 32816 (United States); Graule, Thomas; Kuebler, Jakob [Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for High Performance Ceramics, CH-8600 Dubendorf (Switzerland); Mueller, Martin [Laboratory of Mechanical Metallurgy, EPFL, CH-1015 Lausanne (Switzerland); Gao, Huili [Department of Mechanical Engineering, Texas A& M University, College Station, TX 77843 (United States); Radovic, Miladin [Department of Materials Science and Engineering, Texas A& M University, College Station, TX 77843 (United States); Cullen, David A. [Materials Science & Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

2015-06-15

Highlights: • ReB{sub 2}-type hexagonal OsB{sub 2} powder has been densified by spark plasma sintering. • The sintered OsB{sub 2} contains ∼80 wt.% hexagonal and ∼20 wt.% orthorhombic phases. • The average grain size of the sintered OsB{sub 2} sample was 0.56 ± 0.26 μm. • H = 31 ± 9 GPa and E = 574 ± 112 GPa measured by nanoindentation. - Abstract: The metastable high pressure ReB{sub 2}-type hexagonal OsB{sub 2} bulk ceramics was produced by spark plasma sintering. The phase composition, microstructure, and mechanical behavior of the sintered OsB{sub 2} were studied by X-ray diffraction, optical microscopy, TEM, SEM, EDS, and nanoindentation. The produced ceramics was rather porous and contained a mixture of hexagonal (∼80 wt.%) and orthorhombic (∼20 wt.%) phases as identified by X-ray diffraction and EBSD analysis. Two boron-rich phases, which do not contain Os, were also identified by TEM and SEM/EDS analysis. Nanoindentation measurements yielded a hardness of 31 ± 9 GPa and Young’s modulus of 574 ± 112 GPa, indicating that the material is rather hard and very stiff; however, it is very prone to crack formation and propagation, which is indicative of a very brittle nature of this material. Improvements in the sintering regime are required in order to produce dense, homogeneous and single phase hexagonal OsB{sub 2} bulk ceramics.

Estrogen-Related Receptor Alpha Confers Methotrexate Resistance via Attenuation of Reactive Oxygen Species Production and P53 Mediated Apoptosis in Osteosarcoma Cells

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Peng Chen

2014-01-01

Full Text Available Osteosarcoma (OS is a malignant tumor mainly occurring in children and adolescents. Methotrexate (MTX, a chemotherapy agent, is widely used in treating OS. However, treatment failures are common due to acquired chemoresistance, for which the underlying molecular mechanisms are still unclear. In this study, we report that overexpression of estrogen-related receptor alpha (ERRα, an orphan nuclear receptor, promoted cell survival and blocked MTX-induced cell death in U2OS cells. We showed that MTX induced ROS production in MTX-sensitive U2OS cells while ERRα effectively blocked the ROS production and ROS associated cell apoptosis. Our further studies demonstrated that ERRα suppressed ROS induction of tumor suppressor P53 and its target genes NOXA and XAF1 which are mediators of P53-dependent apoptosis. In conclusion, this study demonstrated that ERRα plays an important role in the development of MTX resistance through blocking MTX-induced ROS production and attenuating the activation of p53 mediated apoptosis signaling pathway, and points to ERRα as a novel target for improving osteosarcoma therapy.

Syntheses, structures and redox properties of some complexes containing the Os(dppe)Cp* fragment, including [{Os(dppe)Cp*}2(mu-C triple bondCC triple bond C)].

Science.gov (United States)

Bruce, Michael I; Costuas, Karine; Davin, Thomas; Halet, Jean-François; Kramarczuk, Kathy A; Low, Paul J; Nicholson, Brian K; Perkins, Gary J; Roberts, Rachel L; Skelton, Brian W; Smith, Mark E; White, Allan H

2007-12-14

The sequential conversion of [OsBr(cod)Cp*] (9) to [OsBr(dppe)Cp*] (10), [Os([=C=CH2)(dppe)Cp*]PF6 ([11]PF6), [Os(C triple bond CH)(dppe)Cp*] (12), [{Os(dppe)Cp*}2{mu-(=C=CH-CH=C=)}][PF6]2 ([13](PF6)2) and finally [{Os(dppe)Cp*}(2)(mu-C triple bond CC triple bond C)] (14) has been used to make the third member of the triad [{M(dppe)Cp*}2(mu-C triple bond CC triple bond C)] (M = Fe, Ru, Os). The molecular structures of []PF6, 12 and 14, together with those of the related osmium complexes [Os(NCMe)(dppe)Cp*]PF6 ([15]PF6) and [Os(C triple bond CPh)(dppe)Cp*] (16), have been determined by single-crystal X-ray diffraction studies. Comparison of the redox properties of 14 with those of its iron and ruthenium congeners shows that the first oxidation potential E1 varies as: Fe approximately Os < Ru. Whereas the Fe complex has been shown to undergo three sequential 1-electron oxidation processes within conventional electrochemical solvent windows, the Ru and Os compounds undergo no fewer than four sequential oxidation events giving rise to a five-membered series of redox related complexes [{M(dppe)Cp*}2(mu-C4)]n+ (n = 0, 1, 2, 3 and 4), the osmium derivatives being obtained at considerably lower potentials than the ruthenium analogues. These results are complimented by DFT and DT DFT calculations.

Resveratrol represses YKL-40 expression in human glioma U87 cells

International Nuclear Information System (INIS)

Zhang, Wei; Tamiya, Takashi; Murao, Koji; Zhang, Xiang; Matsumoto, Kensuke; Diah, Suwarni; Okada, Masaki; Miyake, Keisuke; Kawai, Nobuyuki; Fei, Zhou

2010-01-01

Glioblastoma multiforme (GBM) is the most malignant intracranial tumour that develops in both adults and children. Microarray gene analyses have confirmed that the human YKL-40 gene is one of the most over-expressed genes in these tumours but not in normal brain tissue. Clinical studies have shown that serum YKL-40 levels are positively correlated with tumour burden in addition to being an independent prognostic factor of a short relapse-free interval as well as short overall survival in patients with various cancers. Our previous study revealed that YKL-40 was closely correlated with the pathological grades of human primary astrocytomas and played a crucial role in glioma cell proliferation. Hence, YKL-40 could be an attractive target in the design of anti-cancer therapies. Cell viability and invasion assays were performed to detect the cell proliferation and invasive ability of U87 cells induced by resveratrol (3, 5, 4'-trihydroxystilbene; Res) or YKL-40 small-interfering RNAs (siRNAs). In addition, the luciferase assay, real-time RT-PCR, western blotting, and ELISA were used to measure YKL-40 promoter activity, mRNA, and protein expression, respectively. The expressions of phosphor-ERK1/2 and ERK1/2 were determined by western blotting. Res inhibited U87 cell proliferation and invasion in vitro and repressed YKL-40 in U87 cells by decreasing the activity of its promoter and reducing mRNA transcription and protein expression in vitro. YKL-40 siRNA treatment also impaired the invasiveness of U87 cells. When U87 cells were cultured with 20 μM PD98059 (an ERK1/2 inhibitor) alone, with 20 μM PD98059 and 100 μM Res, or with 100 μM Res alone for 48 h, YKL-40 protein expression decreased most significantly in the Res-treated group. PD98059 partially reversed the decrease of YKL-40 protein expression induced by Res. Furthermore, phosphor-ERK1/2 expression was reduced by Res treatment in a time-dependent manner. We demonstrated for the first time that Res

Effects of MicroRNA-206 on Osteosarcoma Cell Proliferation, Apoptosis, Migration and Invasion by Targeting ANXA2 Through the AKT Signaling Pathway

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Bao-Long Pan

2018-02-01

Full Text Available Background/Aims: This study aimed to investigate the mechanism by which microRNA-206 (miR-206 affects the proliferation, apoptosis, migration and invasion of osteosarcoma (OS cells by targeting ANXA2 via the AKT signaling pathway. Methods: A total of 132 OS tissues and 120 osteochondroma tissues were examined in this study. The targeting relationship between miR-206 and ANXA2 was verified with a dual-luciferase reporter assay. The miR-206 expression and ANXA2, AKT, PARP, FASN, Survivin, Bax, Mcl-1 and Bcl-1 mRNA and protein expression in the above two groups were examined by qRT-PCR and western blotting. The cultured OS cells were divided into 6 groups: a blank group, negative control (NC group, miR-206 mimic group, miR-206 inhibitor group, si-ANXA2 group and miR-206 inhibitor + si-ANXA2 group. Cell cycle and apoptosis were assessed by flow cytometry, cell migration was examined with a wound-healing assay, and cell invasion was assessed with a Transwell assay. Pearson correlation analysis was used to determine the correlation between ANXA2 mRNA expression and miR-206 expression in OS. Results: OS tissues exhibited increased mRNA and protein expression of ANXA2, AKT, PARP, FASN, Survivin, Mcl-1 and Bcl-2; decreased miR-206 expression; and decreased Bax mRNA and protein expression. ANXA2 mRNA expression was strongly negatively correlated with miR-206 expression in OS. ANXA2 was found to be a miR-206 target gene. In the miR-206 mimic group and the si-ANXA2 group, the mRNA and protein expression of ANXA2, AKT, PARP, FASN, Survivin, Mcl-1 and Bcl-1 decreased markedly, cell proliferation was inhibited, apoptosis was promoted, higher cell growth in G1 phase and decreased growth in S phase was detected, and decreased cell migration and invasion were observed compared with those in the blank group. Conclusion: The current results demonstrate that miR-206 overexpression inhibits OS cell proliferation, migration and invasion and promotes apoptosis through

U-251 revisited: genetic drift and phenotypic consequences of long-term cultures of glioblastoma cells

International Nuclear Information System (INIS)

Torsvik, Anja; Stieber, Daniel; Enger, Per Øyvind; Golebiewska, Anna; Molven, Anders; Svendsen, Agnete; Westermark, Bengt; Niclou, Simone P; Olsen, Thale Kristin; Chekenya Enger, Martha; Bjerkvig, Rolf

2014-01-01

It is well known that in vitro subculture represents a selection pressure on cell lines, and over time this may result in a genetic drift in the cancer cells. In addition, long-term cultures harbor the risk of cross-contamination with other cell lines. The consequences may have major impact on experimental results obtained in various laboratories, where the cell lines no longer reflect the original tumors that they are supposed to represent. Much neglected in the scientific community is a close monitoring of cell cultures by regular phenotypic and genetic characterization. In this report, we present a thorough characterization of the commonly used glioblastoma (GBM) model U-251, which in numerous publications has been wrongly identified as U-373, due to an earlier cross-contamination. In this work, the original U-251 and three subclones of U-251, commonly referred to as U-251 or U-373, were analyzed with regard to their DNA profile, morphology, phenotypic expression, and growth pattern. By array comparative genomic hybridization (aCGH), we show that only the original low-passaged U-251 cells, established in the 1960s, maintain a DNA copy number resembling a typical GBM profile, whereas all long-term subclones lost the typical GBM profile. Also the long-term passaged subclones displayed variations in phenotypic marker expression and showed an increased growth rate in vitro and a more aggressive growth in vivo. Taken together, the variations in genotype and phenotype as well as differences in growth characteristics may explain different results reported in various laboratories related to the U-251 cell line

Intracellular fate of recombinant human interferon-gamma (rIFN) in U937 cells

International Nuclear Information System (INIS)

Finbloom, D.S.

1986-01-01

After IFN binds to specific receptors on macrophages, both modulation of surface molecules and induction of microbicidal and tumoricidal activity occurs 24-48 hr later. Since the intracellular events required to insure these responses are poorly defined, the fate of radiolabeled rIFN in U937 cells was examined. Endocytosis was determined by exposing cells to pH 2.5 to allow rIFN to dissociate leaving only intracellular ligand. Degradation was measured as trichloroacetic acid soluble radioactivity in the media. Of the 4-5000 molecules of rIFN that specifically and saturably (at 300 U/ml) bound at 4 0 C, 40% dissociated during 15-30 min after cells were warmed to 37 0 C. However, if cells were continuously exposed at 37 0 C to lower levels of rIFN (60-100 U/ml), 30-40% of those molecules capable of binding to the cell at that concentration were internalized. Furthermore, 60% of the molecules were degraded during 3-4 hr of additional culture. Since exposure of cells to chloroquine and monensin resulted in only partial inhibition of degradation (75% and 43%, respectively), there may also be degradation within endosomes or on the cell following binding to its receptor. Soon thereafter, degradation products are measurable. Since many biological responses require prolonged incubation with the molecule, intracellular processing of IFN may be important for expression of these effects

GLUT-1-independent infection of the glioblastoma/astroglioma U87 cells by the human T cell leukemia virus type 1

International Nuclear Information System (INIS)

Jin Qingwen; Agrawal, Lokesh; VanHorn-Ali, Zainab; Alkhatib, Ghalib

2006-01-01

The human glucose transporter protein 1 (GLUT-1) functions as a receptor for human T cell leukemia virus (HTLV). GLUT-1 is a twelve-transmembrane cell surface receptor with six extracellular (ECL) and seven intracellular domains. To analyze HTLV-1 cytotropism, we utilized polyclonal antibodies to a synthetic peptide corresponding to the large extracellular domain of GLUT-1. The antibodies caused significant blocking of envelope (Env)-mediated fusion and pseudotyped virus infection of HeLa cells but had no significant effect on infection of U87 cells. This differential effect correlated with the detection of high-level surface expression of GLUT-1 on HeLa cells and very weak staining of U87 cells. To investigate this in terms of viral cytotropism, we cloned GLUT-1 cDNA from U87 cells and isolated two different versions of cDNA clones: the wild-type sequence (encoding 492 residues) and a mutant cDNA with a 5-base pair deletion (GLUT-1Δ5) between nucleotides 1329 and 1333. The deletion, also detected in genomic DNA, resulted in a frame-shift and premature termination producing a truncated protein of 463 residues. Transfection of the wild-type GLUT-1 but not GLUT-1Δ5 cDNA into CHO cells resulted in efficient surface expression of the human GLUT-1. Co-expression of GLUT-1 with GLUT-1Δ5 produces a trans-inhibition by GLUT-1Δ5 of GLUT-1-mediated HTLV-1 envelope (Env)-mediated fusion. Co-immunoprecipitation experiments demonstrated physical interaction of the wild-type and mutant proteins. Northern blot and RT-PCR analyses demonstrated lower GLUT-1 RNA expression in U87 cells. We propose two mechanisms to account for the impaired cell surface expression of GLUT-1 on U87 cells: low GLUT-1 RNA expression and the formation of GLUT-1/GLUT-1Δ5 heterodimers that are retained intracellularly. Significant RNAi-mediated reduction of endogenous GLUT-1 expression impaired HTLV-1 Env-mediated fusion with HeLa cells but not with U87 cells. We propose a GLUT-1-independent mechanism

Nongenotoxic p53 activation protects cells against S-phase-specific chemotherapy

DEFF Research Database (Denmark)

Kranz, Dominique; Dobbelstein, Matthias

2006-01-01

Mutations in the tumor suppressor gene TP53 represent the most frequent genetic difference between tumor cells and normal cells. Here, we have attempted to turn this difference into an advantage for normal cells during therapy. Using the Mdm2 antagonist nutlin-3, we first activated p53 in U2OS an...... a killer to a protector of cells, with the potential to reduce unwanted side effects of chemotherapy....

Icariside II induces apoptosis in U937 acute myeloid leukemia cells: role of inactivation of STAT3-related signaling.

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Sang-Hun Kang

Full Text Available BACKGROUND: The aim of this study is to determine anti-cancer effect of Icariside II purified from the root of Epimedium koreanum Nakai on human acute myeloid leukemia (AML cell line U937. METHODOLOGY/PRINCIPAL FINDINGS: Icariside II blocked the growth U937 cells in a dose- and time-dependent manner. In this anti-proliferation process, this herb compound rendered the cells susceptible to apoptosis, manifested by enhanced accumulation of sub-G1 cell population and increased the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL-positive cells. Icariside II was able to activate caspase-3 and cleaved poly (ADP-ribose polymerase (PARP in a time-dependent manner. Concurrently, the anti-apoptotic proteins, such as bcl-x(L and survivin in U937 cells, were downregulated by Icariside II. In addition, Icariside II could inhibit STAT3 phosphorylation and function and subsequently suppress the activation of Janus activated kinase 2 (JAK2, the upstream activators of STAT3, in a dose- and time-dependent manner. Icariside II also enhanced the expression of protein tyrosine phosphatase (PTP SH2 domain-containing phosphatase (SHP-1, and the addition of sodium pervanadate (a PTP inhibitor prevented Icariside II-induced apoptosis as well as STAT3 inactivation in STAT3 positive U937 cells. Furthermore, silencing SHP-1 using its specific siRNA significantly blocked STAT3 inactivation and apoptosis induced by Icariside II in U937 cells. CONCLUSIONS/SIGNIFICANCE: Our results demonstrated that via targeting STAT3-related signaling, Icariside II sensitizes U937 cells to apoptosis and perhaps serves as a potent chemotherapeutic agent for AML.

A miR-21 inhibitor enhances apoptosis and reduces G2-M accumulation induced by ionizing radiation in human glioblastoma U251 cells

International Nuclear Information System (INIS)

Li, Yi; Li, Qiang; Asai, Akio; Kawamoto, Keiji; Zhao Shiguang; Zhen Yunbo; Teng Lei

2011-01-01

MicroRNAs (miRNAs) are small noncoding RNAs that take part in diverse biological processes by suppressing target gene expression. Elevated expression of miR-21 has been reported in many types of human cancers. Radiotherapy is a standard adjuvant treatment for patients with glioblastoma. However, the resistance of glioblastoma cells to radiation limits the success of this treatment. In this study, we found that miR-21 expression was upregulated in response to ionizing radiation (IR) in U251 cells, which suggested that miR-21 could be involved in the response of U251 cells to radiation. We showed that a miR-21 inhibitor enhanced IR-induced glioblastoma cell growth arrest and increased the level of apoptosis, which was probably caused by abrogation of the G 2 -M arrest induced by IR. Further research demonstrated that the miR-21 inhibitor induced the upregulation of Cdc25A. Taken together, these findings suggest that miR-21 inhibitor can increase IR-induced growth arrest and apoptosis in U251 glioblastoma cells, at least in part by abrogating G 2 -M arrest, and that Cdc25A is a potential target of miR-21. (author)

Fuel Cell Buses in U.S. Transit Fleets: Current Status 2016

Energy Technology Data Exchange (ETDEWEB)

Eudy, Leslie [National Renewable Energy Lab. (NREL), Golden, CO (United States); Post, Matthew [National Renewable Energy Lab. (NREL), Golden, CO (United States); Jeffers, Matthew [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-11-01

This report, published annually, summarizes the progress of fuel cell electric bus development in the United States and discusses the achievements and challenges of introducing fuel cell propulsion in transit. The report provides a summary of results from evaluations performed by the National Renewable Energy Laboratory. Funding for this effort is provided by the U.S. Department of Energy's Fuel Cell Technologies Office within the Office of Energy Efficiency and Renewable Energy and by the U.S. Department of Transportation's Federal Transit Administration. The 2016 summary results primarily focus on the most recent year for each demonstration, from August 2015 through July 2016. The results for these buses account for more than 550,000 miles traveled and 59,500 hours of fuel cell power system operation. The primary results presented in the report are from three demonstrations of two different fuel-cell-dominant bus designs: Zero Emission Bay Area Demonstration Group led by Alameda-Contra Costa Transit District (AC Transit) in California; American Fuel Cell Bus Project at SunLine Transit Agency in California; and American Fuel Cell Bus Project at the University of California at Irvine.

Delocalized Claudin-1 promotes metastasis of human osteosarcoma cells

Energy Technology Data Exchange (ETDEWEB)

Jian, Yuekui; Chen, Changqiong; Li, Bo; Tian, Xiaobin, E-mail: drtxb_guiyang@sina.com

2015-10-23

Tight junction proteins (TJPs) including Claudins, Occludin and tight junction associated protein Zonula occludens-1 (ZO-1), are the most apical component of junctional complex that mediates cell–cell adhesion in epithelial and endothelial cells. In human malignancies, TJPs are often deregulated and affect cellular behaviors of tumor cells. In this study, we investigated alternations of TJPs and related biological characteristics in human osteosarcoma (OS). Claudin1 was increased in the metastatic OS cells (KRIB and KHOS) compared with the normal osteoblast cells (hFOB1.19) or primary tumor cells (HOS and U2OS), whereas no significant difference was found in Occludin and ZO-1. Immunohistochemistry, immunofluorescence and Western blotting revealed that Claudin1 was initially localized at cell junctions of normal osteoblasts, but substantially delocalized to the nucleus of metastatic OS cells. Phenotypically, inhibition of the nucleus Claudin1 expression compromised the metastatic potential of KRIB and KHOS cells. Moreover, we found that protein kinase C (PKC) but not PKA phosphorylation influenced Claudin1 expression and cellular functions, as PKC inhibitor (Go 6983 and Staurosporine) or genetic silencing of PKC reduced Claudin1 expression and decreased the motility of KRIB and KHOS cells. Taken together, our study implied that delocalization of claudin-1 induced by PKC phosphorylation contributes to metastatic capacity of OS cells. - Highlights: • Claudin1 is increased during the malignant transformation of human OS. • Delocalization of Claudin1 in metastatic OS cells. • Silencing nuclear Claudin1 expression inhibits cell invasion of OS. • Deregulated Claudin1 is regulated by PKC.

Non-thermal atmospheric pressure plasma inhibits thyroid papillary cancer cell invasion via cytoskeletal modulation, altered MMP-2/-9/uPA activity.

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Jae Won Chang

Full Text Available Plasma, the fourth state of matter, is defined as a partially or completely ionized gas that includes a mixture of electrons and ions. Advances in plasma physics have made it possible to use non-thermal atmospheric pressure plasma (NTP in cancer research. However, previous studies have focused mainly on apoptotic cancer cell death mediated by NTP as a potential cancer therapy. In this study, we investigated the effect of NTP on invasion or metastasis, as well as the mechanism by which plasma induces anti-migration and anti-invasion properties in human thyroid papillary cancer cell lines (BHP10-3 and TPC1. Wound healing, pull-down, and Transwell assays demonstrated that NTP reduced cell migration and invasion. In addition, NTP induced morphological changes and cytoskeletal rearrangements, as detected by scanning electron microscopy and immunocytochemistry. We also examined matrix metalloproteinase (MMP-2/-9 and urokinase-type plasminogen activator (uPA activity using gelatin zymography, uPA assays and RT-PCR. FAK, Src, and paxillin expression was detected using Western blot analyses and immunocytochemistry. NTP decreased FAK, Src, and paxillin expression as well as MMP/uPA activity. In conclusion, NTP inhibited the invasion and metastasis of BHP10-3 and TPC1 cells by decreasing MMP-2/-9 and uPA activities and rearranging the cytoskeleton, which is regulated by the FAK/Src complex. These findings suggest novel actions for NTP and may aid in the development of new therapeutic strategies for locally invasive and metastatic cancers.

Rhythmic expression of DEC2 protein in vitro and in vivo.

Science.gov (United States)

Sato, Fuyuki; Muragaki, Yasuteru; Kawamoto, Takeshi; Fujimoto, Katsumi; Kato, Yukio; Zhang, Yanping

2016-06-01

Basic helix-loop-helix (bHLH) transcription factor DEC2 (bHLHE41/Sharp1) is one of the clock genes that show a circadian rhythm in various tissues. DEC2 regulates differentiation, sleep length, tumor cell invasion and apoptosis. Although studies have been conducted on the rhythmic expression of DEC2 mRNA in various tissues, the precise molecular mechanism of DEC2 expression is poorly understood. In the present study, we examined whether DEC2 protein had a rhythmic expression. Western blot analysis for DEC2 protein revealed a rhythmic expression in mouse liver, lung and muscle and in MCF-7 and U2OS cells. In addition, AMP-activated protein kinase (AMPK) activity (phosphorylation of AMPK) in mouse embryonic fibroblasts (MEFs) exhibited a rhythmic expression under the condition of medium change or glucose-depleted medium. However, the rhythmic expression of DEC2 in MEF gradually decreased in time under these conditions. The medium change affected the levels of DEC2 protein and phosphorylation of AMPK. In addition, the levels of DEC2 protein showed a rhythmic expression in vivo and in MCF-7 and U2OS cells. The results showed that the phosphorylation of AMPK immunoreactivity was strongly detected in the liver and lung of DEC2 knockout mice compared with that of wild-type mice. These results may provide new insights into rhythmic expression and the regulation between DEC2 protein and AMPK activity.

Enhancer of Zeste Homolog 2 Overexpression in Nasopharyngeal Carcinoma: An Independent Poor Prognosticator That Enhances Cell Growth

International Nuclear Information System (INIS)

Hwang, Chung-Feng; Huang, Hsuan-Ying; Chen, Chang-Han; Chien, Chih-Yen; Hsu, Yao-Chung; Li, Chien-Feng

2012-01-01

Purpose: As a key component of polycomb-repressive complex 2, enhancer of zeste homolog 2 (EZH2) represses target genes through histone methylation and is frequently overexpressed and associated with poor prognosis in common carcinomas. For the first time, we reported EZH2 expression and its biological and clinical significance in nasopharyngeal carcinoma (NPC). Methods and Materials: In NPC cell lines and specimens, endogenous expression of EZH2 mRNA and protein was determined by semiquantitative reverse transcription–polymerase chain reaction and immunoblotting, respectively. To analyze the effect on cell growth, stable silencing of EZH2 was established in EZH2-expressing TW02 NPC cells with RNA interference. EZH2 immunolabeling was assessable for 89 primary NPC biopsy samples and correlated with clinicopathological variables, disease-specific survival (DSS), and overall survival (OS). Results: Growth activity of TW02 cells was significantly suppressed (p < 0.001) with stable EZH2 silencing. Compared with normal nasopharyngeal tissue, expression levels of EZH2 transcript and protein were apparently upregulated in NPC specimens. As a continuous variable, higher EZH2 expression preferentially occurred in NPCs of T3 to T4 stages (p = 0.03) and significantly predicted inferior DSS (p = 0.0010) and OS (p = 0.004). The prognostic implications for DSS (p = 0.010) and OS (p = 0.006) still remained valid when using the median (≥60%) of EZH2 immunolabeling index to dichotomize the cohort. In the multivariate model, higher EZH2 expression was an independent adverse factor of both DSS (p = 0.012) and OS (p = 0.011), along with American Joint Committee on Cancer Stages III to IV (p = 0.024 for DSS, p = 0.017 for OS). Conclusion: At least partly through promoting cell growth, EZH2 implicates disease progression, confers tumor aggressiveness, and represents an independent adverse prognosticator in patients with NPC.

miR-99 inhibits cervical carcinoma cell proliferation by targeting TRIB2.

Science.gov (United States)

Xin, Jia-Xuan; Yue, Zhen; Zhang, Shuai; Jiang, Zhong-Hua; Wang, Ping-Yu; Li, You-Jie; Pang, Min; Xie, Shu-Yang

2013-10-01

MicroRNAs (miRNAs) have significant roles in cell processes, including proliferation, apoptosis and stress responses. To investigate the involvement of miR-99 in the inhibition of HeLa cell proliferation, an miR-99 gene expression vector (pU6.1/miR-99), which overexpressed miR-99 in HeLa cells after transient transfection, was constructed. The expression of miR-99 was detected by qPCR. Cell proliferation and apoptosis were analyzed by cell viability, proliferation and apoptosis assays, as well as by electron microscopy. The results showed that overexpression of miR-99 in HeLa cells increased the HeLa cell mortality rate. Moreover, miR-99 overexpression was able to markedly inhibit HeLa cell proliferation according to the 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The cell apoptosis rate was significantly higher in pU6.1/miR-99-treated cells compared with that in the control cultures. Increases in intracellular electron density, as well as the proportion of nuclear plasma, blebbing phenomena and apoptotic bodies were observed in pU6.1/miR-99-treated cells compared with control cultures according to electron microscopy analysis. The Tribbles 2 (TRIB2) 3'-untranslated region was also observed to be targeted by miR-99 and the results further demonstrated that miR-99 was able to negatively regulate TRIB2 expression in HeLa cells The results indicate that miR-99 acts as a tumor suppressor gene in HeLa cells, establishing a theoretical basis for its application in cancer therapeutics.

The nido-osmaboranes [2,2,2-(CO)(PPh(3))(2)-nido-2-OsB(5)H(9)] and [6,6,6-(CO)(PPh(3))(2)-nido-6-OsB(9)H(13)].

Science.gov (United States)

Bould, J; Kennedy, J D; Thomas, R L; Rath, N P; Barton, L

2001-11-01

The structural characterization of the osmahexaborane 2-carbonyl-2,2-bis(triphenylphosphine)-nido-2-osmahexaborane(9), [Os(B(5)H(9))(C(18)H(15)P)(2)(CO)], (I), a metallaborane analogue of B(6)H(10), confirms the structure proposed from NMR spectroscopy. The structure of the osmadecaborane 6-carbonyl-6,6-bis(triphenylphosphine)-nido-6-osmadecaborane(13), [Os(B(9)H(13))(C(18)H(15)P)(2)(CO)], (IV), is similarly confirmed. The short basal B-B distance of 1.652 (8) A in (I), not bridged by an H atom, mirrors that in the parent hexaborane(10) [1.626 (4) A].

An in vitro investigation of bacteria-osteoblast competition on oxygen plasma-modified PEEK.

Science.gov (United States)

Rochford, Edward T J; Subbiahdoss, Guruprakash; Moriarty, T Fintan; Poulsson, Alexandra H C; van der Mei, Henny C; Busscher, Henk J; Richards, R Geoff

2014-12-01

Polyetheretherketone (PEEK) films were oxygen plasma treated to increase surface free energy and characterized by X-ray photoelectron microscopy, atomic force microscopy, and water contact angles. A parallel plate flow chamber was used to measure Staphylococcus epidermidis, Staphylococcus aureus, and U-2 OS osteosarcomal cell-line adhesion to the PEEK films in separate monocultures. In addition, bacteria and U-2 OS cells were cocultured to model competition between osteoblasts and contaminating bacteria for the test surfaces. Plasma treatment of the surfaces increased surface oxygen content and decreased the hydrophobicity of the materials, but did not lead to a significant difference in bacterial or U-2 OS cell adhesion in the monocultures. In the S. epidermidis coculture experiments, the U-2 OS cells adhered in greater numbers on the treated surfaces compared to the untreated PEEK and spread to a similar extent. However, in the presence of S. aureus, cell death of the U-2 OS occurred within 10 h on all surfaces. The results of this study suggest that oxygen plasma treatment of PEEK may maintain the ability of osteoblast-like cells to adhere and spread, even in the presence of S. epidermidis contamination, without increasing the risk of preoperative bacterial adhesion. Therefore, oxygen plasma-treated PEEK remains a promising method to improve implant surface free energy for osseointegration. © 2014 Wiley Periodicals, Inc.

Low-temperature processed ultrathin TiO2 for efficient planar heterojunction perovskite solar cells

International Nuclear Information System (INIS)

Huang, Xiaokun; Hu, Ziyang; Xu, Jie; Wang, Peng; Zhang, Jing; Zhu, Yuejin

2017-01-01

Highlights: • An ultrathin and discrete TiO 2 (u-TiO 2 ) was fabricated at low temperature. • High-performance perovskite solar cells based u-TiO 2 was realized. • u-TiO 2 between perovskite and FTO functions as a bridge for electron transport. • u-TiO 2 accelerates electron transfer and alleviates charge recombination. - Abstract: A compact TiO 2 (c-TiO 2 ) layer fabricated by spin coating or spray pyrolysis following a high-temperature sintering is a routine in high-performance planar heterojunction perovskite solar cells. Here, we demonstrate an effective low-temperature approach to fabricate an ultrathin and discrete TiO 2 (u-TiO 2 ) for enhancing photovoltaic performance of perovskite solar cells. Via hydrolysis of low-concentration TiCl 4 solution at 70 °C, u-TiO 2 was grown on a fluorine doped tin oxide (FTO) substrate, forming the electron selective contact with the photoactive CH 3 NH 3 PbI 3 film. The perovskite solar cell using u-TiO 2 achieves an efficiency of 13.42%, which is compared to 13.56% of the device using c-TiO 2 prepared by high-temperature sintering. Cyclic voltammetry, steady-state photoluminescence spectroscopy and electrical impedance spectroscopy were conducted to study interface engineering and charge carrier dynamics. Our results suggest that u-TiO 2 functions as a bridge for electron transport between perovskite and FTO, which accelerates electron transfer and alleviates charge recombination.

Re-Os, Sm-Nd, U-Pb, and stepwise lead leaching isotope systematics in shear-zone hosted gold mineralization: genetic tracing and age constraints of crustal hydrothermal activity

Science.gov (United States)

Frei, R.; Nägler, Th. F.; Schönberg, R.; Kramers, J. D.

1998-06-01

A combined Re-Os, Sm-Nd, U-Pb, and stepwise Pb leaching (PbSL) isotope study of hydrothermal (Mo-W)-bearing minerals and base metal sulfides from two adjacent shear zone hosted gold deposits (RAN, Kimberley) in the Harare-Shamva greenstone belt (Zimbabwe) constrain the timing of the mineralizing events to two periods. During an initial Late Archean event (2.60 Ga) a first molybdenite-scheelite bearing paragenesis was deposited in both shear zone systems, followed by a local reactivation of the shear systems during an Early Proterozoic (1.96 Ga) tectono-thermal overprint, during which base metal sulfides and most of the gold was (re-)deposited. While PbSL has revealed an open-system behavior of the U-Pb systematics in molybdenite and wolframite from the RAN mine, initial Archean Re-Os ages are still preserved implying that this system in these minerals was more resistant to the overprint. A similar retentivity could be shown for the Sm-Nd system in scheelite and powellite associated with the above ore minerals. Re-Os isotopic data from the Proterozoic mineralization in the Kimberley mine point to a recent gain of Re, most pronouncedly affecting Fe-rich sulfides such as pyrrhotite. A significant Re-loss in powellitic scheelite (an alteration phase of molybdenite-bearing scheelite), coupled with a marked loss of U in W-Mo ore minerals, complements the observation of a major Re uptake in Fe-sulfides during oxidizing conditions in a weathering environment. Pyrrhotite under these conditions behaves as an efficient Re-sink. Lead isotope signatures from PbSL residues of molybdenite, powellite, and quartz indicate a continental crustal source and/or contamination for the mineralizing fluid by interaction of the fluids with older sedimentary material as represented by the direct host country rocks. Our investigation reveals the potential of the Re-Os isotopic system applied to crustal hydrothermal ore minerals for genetic tracing and dating purposes. The simplified chemical

Classical NF-κB Metabolically Reprograms Sarcoma Cells Through Regulation of Hexokinase 2

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Priya Londhe

2018-04-01

Full Text Available BackgroundMetabolic reprogramming has emerged as a cancer hallmark, and one of the well-known cancer-associated metabolic alterations is the increase in the rate of glycolysis. Recent reports have shown that both the classical and alternative signaling pathways of nuclear factor κB (NF-κB play important roles in controlling the metabolic profiles of normal cells and cancer cells. However, how these signaling pathways affect the metabolism of sarcomas, specifically rhabdomyosarcoma (RMS and osteosarcoma (OS, has not been characterized.MethodsClassical NF-κB activity was inhibited through overexpression of the IκBα super repressor of NF-κB in RMS and OS cells. Global gene expression analysis was performed using Affymetrix GeneChip Human Transcriptome Array 2.0, and data were interpreted using gene set enrichment analysis. Seahorse Bioscience XFe24 was used to analyze oxygen consumption rate as a measure of aerobic respiration.ResultsInhibition of classical NF-κB activity in sarcoma cell lines restored alternative signaling as well as an increased oxidative respiratory metabolic phenotype in vitro. In addition, microarray analysis indicated that inhibition of NF-κB in sarcoma cells reduced glycolysis. We showed that a glycolytic gene, hexokinase (HK 2, is a direct NF-κB transcriptional target. Knockdown of HK2 shifted the metabolic profile in sarcoma cells away from aerobic glycolysis, and re-expression of HK2 rescued the metabolic shift induced by inhibition of NF-κB activity in OS cells.ConclusionThese findings suggest that classical signaling of NF-κB plays a crucial role in the metabolic profile of pediatric sarcomas potentially through the regulation of HK2.

Crystal structures of Th(OH)PO4, U(OH)PO4 and Th2O(PO4)2. Condensation mechanism of M(IV)(OH)PO4 (M= Th, U) into M2O(PO4)2

International Nuclear Information System (INIS)

Dacheux, N.; Clavier, N.; Wallez, G.; Quarton, M.

2007-01-01

Three new crystal structures, isotypic with β-Zr 2 O(PO 4 ) 2 , have been resolved by the Rietveld method. All crystallize with an orthorhombic cell (S.G.: Cmca) with a = 7.1393(2) Angstroms, b = 9.2641(2) Angstroms, c 12.5262(4) Angstroms, V = 828.46(4) (Angstroms) 3 and Z = 8 for Th(OH)PO 4 ; a = 7.0100(2) Angstroms, b = 9.1200(2) Angstroms, c = 12.3665(3) Angstroms, V 790.60(4) (Angstroms) 3 and Z = 8 for U(OH)PO 4 ; a 7.1691(3) Angstroms, b 9.2388(4) Angstroms, c = 12.8204(7) Angstroms, V 849.15(7) (Angstroms) 3 and Z = 4 for Th 2 O(PO 4 ) 2 . By heating, the M(OH)PO 4 (M Th, U) compounds condense topotactically into M 2 O(PO 4 ) 2 , with a change of the environment of the tetravalent cation that lowers from 8 to 7 oxygen atoms. The lower stability of Th 2 O(PO 4 ) 2 compared to that of U 2 O(PO 4 ) 2 seems to result from this unusual environment for tetravalent thorium. (authors)

Molecular characterization and functional analysis of OsPHY2, a ...

African Journals Online (AJOL)

use

2011-09-19

Sep 19, 2011 ... The phytase activities were assayed according to .... determined at 1.50 A resolution, OsPHY2 exhibits a .... polyA promoter promoter. polyA. A. Poly A. Figure 8. The transcripts of OsPHY2 in the generated transgenic tobacco ...

B11 NMR in the layered diborides OsB2 and RuB2

Science.gov (United States)

Suh, B. J.; Zong, X.; Singh, Y.; Niazi, A.; Johnston, D. C.

2007-10-01

B11 nuclear magnetic resonance (NMR) measurements have been performed on B11 enriched OsB2 and RuB2 polycrystalline powder samples in an external field of 4.7T and in the temperature range, 4.2KOsB2 and RuB2 , respectively. The experimental results indicate that a p character dominates the conduction electron wave function at the B site with a negligibly small s character in both compounds.

Modeled microgravity suppressed invasion and migration of human glioblastoma U87 cells through downregulating store-operated calcium entry

Energy Technology Data Exchange (ETDEWEB)

Shi, Zi-xuan [Department of Traditional Chinese Medicine, Xijing Hospital, Fourth Military Medical University, Xi' an, 710032 (China); Rao, Wei [Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi' an, 710032 (China); Wang, Huan [Department of Dermatology, Tangdu Hospital, Fourth Military Medical University, Xi' an, 710032 (China); Wang, Nan-ding [Department of Cardiology, Xi' an Traditional Chinese Medicine Hospital, Xi' an, 710032 (China); Si, Jing-Wen; Zhao, Jiao; Li, Jun-chang [Department of Traditional Chinese Medicine, Xijing Hospital, Fourth Military Medical University, Xi' an, 710032 (China); Wang, Zong-ren, E-mail: zongren@fmmu.edu.cn [Department of Traditional Chinese Medicine, Xijing Hospital, Fourth Military Medical University, Xi' an, 710032 (China)

2015-02-13

Glioblastoma is the most common brain tumor and is characterized with robust invasion and migration potential resulting in poor prognosis. Previous investigations have demonstrated that modeled microgravity (MMG) could decline the cell proliferation and attenuate the metastasis potential in several cell lines. In this study, we studied the effects of MMG on the invasion and migration potentials of glioblastoma in human glioblastoma U87 cells. We found that MMG stimulation significantly attenuated the invasion and migration potentials, decreased thapsigargin (TG) induced store-operated calcium entry (SOCE) and downregulated the expression of Orai1 in U87 cells. Inhibition of SOCE by 2-APB or stromal interaction molecule 1 (STIM1) downregulation both mimicked the effects of MMG on the invasion and migration potentials in U87 cells. Furthermore, upregulation of Orai1 significantly weakened the effects of MMG on the invasion and migration potentials in U87 cells. Therefore, these findings indicated that MMG stimulation inhibited the invasion and migration potentials of U87 cells by downregulating the expression of Orai1 and sequentially decreasing the SOCE, suggesting that MMG might be a new potential therapeutic strategy in glioblastoma treatment in the future. - Highlights: • Modeled microgravity (MMG) suppressed migration and invasion in U87 cells. • MMG downregulated the SOCE and the expression of Orai1. • SOCE inhibition mimicked the effects of MMG on migration and invasion potentials. • Restoration of SOCE diminished the effects of MMG on migration and invasion.

Modeled microgravity suppressed invasion and migration of human glioblastoma U87 cells through downregulating store-operated calcium entry

International Nuclear Information System (INIS)

Shi, Zi-xuan; Rao, Wei; Wang, Huan; Wang, Nan-ding; Si, Jing-Wen; Zhao, Jiao; Li, Jun-chang; Wang, Zong-ren

2015-01-01

Glioblastoma is the most common brain tumor and is characterized with robust invasion and migration potential resulting in poor prognosis. Previous investigations have demonstrated that modeled microgravity (MMG) could decline the cell proliferation and attenuate the metastasis potential in several cell lines. In this study, we studied the effects of MMG on the invasion and migration potentials of glioblastoma in human glioblastoma U87 cells. We found that MMG stimulation significantly attenuated the invasion and migration potentials, decreased thapsigargin (TG) induced store-operated calcium entry (SOCE) and downregulated the expression of Orai1 in U87 cells. Inhibition of SOCE by 2-APB or stromal interaction molecule 1 (STIM1) downregulation both mimicked the effects of MMG on the invasion and migration potentials in U87 cells. Furthermore, upregulation of Orai1 significantly weakened the effects of MMG on the invasion and migration potentials in U87 cells. Therefore, these findings indicated that MMG stimulation inhibited the invasion and migration potentials of U87 cells by downregulating the expression of Orai1 and sequentially decreasing the SOCE, suggesting that MMG might be a new potential therapeutic strategy in glioblastoma treatment in the future. - Highlights: • Modeled microgravity (MMG) suppressed migration and invasion in U87 cells. • MMG downregulated the SOCE and the expression of Orai1. • SOCE inhibition mimicked the effects of MMG on migration and invasion potentials. • Restoration of SOCE diminished the effects of MMG on migration and invasion

The nitric oxide donor JS-K sensitizes U87 glioma cells to repetitive irradiation.

Science.gov (United States)

Heckler, Max; Osterberg, Nadja; Guenzle, Jessica; Thiede-Stan, Nina Kristin; Reichardt, Wilfried; Weidensteiner, Claudia; Saavedra, Joseph E; Weyerbrock, Astrid

2017-06-01

As a potent radiosensitizer nitric oxide (NO) may be a putative adjuvant in the treatment of malignant gliomas which are known for their radio- and chemoresistance. The NO donor prodrug JS-K (O2-(2.4-dinitrophenyl) 1-[(4-ethoxycarbonyl) piperazin-1-yl] diazen-1-ium-1,2-diolate) allows cell-type specific intracellular NO release via enzymatic activation by glutathione-S-transferases overexpressed in glioblastoma multiforme. The cytotoxic and radiosensitizing efficacy of JS-K was assessed in U87 glioma cells in vitro focusing on cell proliferation, induction of DNA damage, and cell death. In vivo efficacy of JS-K and repetitive irradiation were investigated in an orthotopic U87 xenograft model in mice. For the first time, we could show that JS-K acts as a potent cytotoxic and radiosensitizing agent in U87 cells in vitro. This dose- and time-dependent effect is due to an enhanced induction of DNA double-strand breaks leading to mitotic catastrophe as the dominant form of cell death. However, this potent cytotoxic and radiosensitizing effect could not be confirmed in an intracranial U87 xenograft model, possibly due to insufficient delivery into the brain. Although NO donor treatment was well tolerated, neither a retardation of tumor growth nor an extended survival could be observed after JS-K and/or radiotherapy.

The APETALA-2-like transcription factor OsAP2-39 controls key interactions between abscisic acid and gibberellin in rice.

Science.gov (United States)

Yaish, Mahmoud W; El-Kereamy, Ashraf; Zhu, Tong; Beatty, Perrin H; Good, Allen G; Bi, Yong-Mei; Rothstein, Steven J

2010-09-09

The interaction between phytohormones is an important mechanism which controls growth and developmental processes in plants. Deciphering these interactions is a crucial step in helping to develop crops with enhanced yield and resistance to environmental stresses. Controlling the expression level of OsAP2-39 which includes an APETALA 2 (AP2) domain leads to phenotypic changes in rice. Overexpression of OsAP2-39 leads to a reduction in yield by decreasing the biomass and the number of seeds in the transgenic rice lines. Global transcriptome analysis of the OsAP2-39 overexpression transgenic rice revealed the upregulation of a key abscisic acid (ABA) biosynthetic gene OsNCED-I which codes for 9-cis-epoxycarotenoid dioxygenase and leads to an increase in the endogenous ABA level. In addition to OsNCED-1, the gene expression analysis revealed the upregulation of a gene that codes for the Elongation of Upper most Internode (EUI) protein, an enzyme that catalyzes 16α, 17-epoxidation of non-13-hydroxylated GAs, which has been shown to deactivate gibberellins (GAs) in rice. The exogenous application of GA restores the wild-type phenotype in the transgenic line and ABA application induces the expression of EUI and suppresses the expression of OsAP2-39 in the wild-type line. These observations clarify the antagonistic relationship between ABA and GA and illustrate a mechanism that leads to homeostasis of these hormones. In vivo and in vitro analysis showed that the expression of both OsNCED-1 and EUI are directly controlled by OsAP2-39. Together, these results reveal a novel mechanism for the control of the ABA/GA balance in rice which is regulated by OsAP2-39 that in turn regulates plant growth and seed production.

The APETALA-2-like transcription factor OsAP2-39 controls key interactions between abscisic acid and gibberellin in rice.

Directory of Open Access Journals (Sweden)

Mahmoud W Yaish

2010-09-01

Full Text Available The interaction between phytohormones is an important mechanism which controls growth and developmental processes in plants. Deciphering these interactions is a crucial step in helping to develop crops with enhanced yield and resistance to environmental stresses. Controlling the expression level of OsAP2-39 which includes an APETALA 2 (AP2 domain leads to phenotypic changes in rice. Overexpression of OsAP2-39 leads to a reduction in yield by decreasing the biomass and the number of seeds in the transgenic rice lines. Global transcriptome analysis of the OsAP2-39 overexpression transgenic rice revealed the upregulation of a key abscisic acid (ABA biosynthetic gene OsNCED-I which codes for 9-cis-epoxycarotenoid dioxygenase and leads to an increase in the endogenous ABA level. In addition to OsNCED-1, the gene expression analysis revealed the upregulation of a gene that codes for the Elongation of Upper most Internode (EUI protein, an enzyme that catalyzes 16α, 17-epoxidation of non-13-hydroxylated GAs, which has been shown to deactivate gibberellins (GAs in rice. The exogenous application of GA restores the wild-type phenotype in the transgenic line and ABA application induces the expression of EUI and suppresses the expression of OsAP2-39 in the wild-type line. These observations clarify the antagonistic relationship between ABA and GA and illustrate a mechanism that leads to homeostasis of these hormones. In vivo and in vitro analysis showed that the expression of both OsNCED-1 and EUI are directly controlled by OsAP2-39. Together, these results reveal a novel mechanism for the control of the ABA/GA balance in rice which is regulated by OsAP2-39 that in turn regulates plant growth and seed production.

DNA replication and repair of Tilapia cells: Pt. 2

International Nuclear Information System (INIS)

Chen, J.D.; Yew, F.H.

1988-01-01

TO-2 is a fish cell line derived from the Tilapia ovary. It grows over a wide range of temperature (15-34 0 C). We report the effects of temperature on DNA replication and u.v. repair in TO-2 cells. When the cells were moved from 31 0 C to the sublethal high temperature of 37 0 C, the rate of DNA synthesis first decreased to 60%, then speedy recovery soon set in, and after 8h at 37 0 C the rate of DNA synthesis overshot the 31 0 C control level by 180%. When moved to low temperature (18 0 C) Tilapia cells also showed an initial suppression of DNA synthesis before settling at 30% of the control level. U.V. reduced but could not block DNA synthesis completely. The inhibition was overcome in 3h at 37, 31 and 25 0 C, but not at 18 0 C. Initiation of nascent DNA synthesis was blocked at 4Jm -2 in TO-2 cells compared with ≤ 1Jm -2 in mammalian cells. After 9Jm -2 u.v. irradiation, low molecular weight DNA replication intermediates started to accumulate. TO-2 cells showed low levels of u.v.-induced excision repair. (author)

HER2 induces cell proliferation and invasion of non-small-cell lung cancer by upregulating COX-2 expression via MEK/ERK signaling pathway

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Chi F

2016-05-01

Full Text Available Feng Chi, Rong Wu, Xueying Jin, Min Jiang, Xike Zhu Department of Medical Oncology, Shengjing Hospital of China Medical University, Shenyang, People’s Republic of China Abstract: HER2 positivity has been well studied in various cancers, but its importance in non-small-cell lung cancer (NSCLC is still being explored. In this study, quantitative reverse transcription polymerase chain reaction (qRT-PCR was performed to detect HER2 and COX-2 expression in NSCLC tissues. Then, pcDNA3.1-HER2 was used to overexpress HER2, while HER2 siRNA and COX-2 siRNA were used to silence HER2 and COX-2 expression. MTT assay and invasion assay were used to detect the effects of HER2 on cell proliferation and invasion. Our study revealed that HER2 and COX-2 expression were upregulated in NSCLC tissues and HER2 exhibited a significant positive correlation with the levels of COX-2 expression. Overexpression of HER2 evidently elevated COX-2 expression, while silencing of HER2 evidently decreased COX-2 expression. Furthermore, overexpressed HER2 induced the ERK phosphorylation, and this was abolished by the treatment with U0126, a pharmacological inhibitor of MEK, an upstream kinase of ERK. HER2-induced expression and promoter activity of COX-2 were also suppressed by U0126, suggesting that the MEK/ERK signaling pathway regulates COX-2 expression. In addition, HER2 induced activation of AKT signaling pathway, which was reversed by pretreatment with U0126 and COX-2 siRNA. MTT and invasion assays revealed that HER2 induced cell proliferation and invasion that were reversed by pretreatment with U0126 and COX-2 siRNA. In this study, our results demonstrated for the first time that HER2 elevated COX-2 expression through the activation of MEK/ERK pathway, which subsequently induced cell proliferation and invasion via AKT pathway in NSCLC tissues. Keywords: HER2, MEK/ERK, COX-2, AKT signaling pathway, non-small-cell lung cancer

Oleocanthal Modulates Estradiol-Induced Gene Expression Involving Estrogen Receptor α.

Science.gov (United States)

Keiler, Annekathrin Martina; Djiogue, Sefirin; Ehrhardt, Tino; Zierau, Oliver; Skaltsounis, Leandros; Halabalaki, Maria; Vollmer, Günter

2015-09-01

Oleocanthal is a bioactive compound from olive oil. It has attracted considerable attention as it is anti-inflammatory, antiproliferative, and has been shown to possess neuroprotective properties in vitro and in vivo. Delineated from its polyphenolic structure, the aim of this study was to characterize oleocanthal towards estrogenic properties. This might contribute to partly explain the beneficial effects described for the Mediterranean diet. Estrogenic properties of oleocanthal were assessed by different methods: a) stimulation of reporter gene activity in MVLN or RNDA cells either expressing estrogen receptor α or β, b) stimulation of luciferase reporter gene activity in U2OS osteosarcoma cells expressing estrogen receptor α or β, and c) elucidation of the impact on estradiol-induced gene expression in U2OS cells transduced with both estrogen receptors. Depending on the cell line origin, oleocanthal inhibited luciferase activity (MVLN, U2OS-estrogen receptor β) or weakly induced reporter gene activity at 10 µM in U2OS-estrogen receptor α cells. However, oleocanthal inhibited stimulation of luciferase activity by estradiol from both estrogen receptors. Oleocanthal, if given alone, did not stimulate gene expression in U2OS cells, but it significantly modulated the response of estradiol. Oleocanthal enhanced the effect of estradiol on the regulation of those genes, which are believed to be regulated through heterodimeric estrogen receptors. As the estrogenic response pattern of oleocanthal is rather unique, we compared the results obtained with oleacein. Oleocanthal binds to both estrogen receptors inducing estradiol-agonistic or antiagonistic effects depending on the cell line. Regarding regulation of gene expression in U2OS-estrogen receptor α/β cells, oleocanthal and oleacein enhanced estradiol-mediated regulation of heterodimer-regulated genes. Georg Thieme Verlag KG Stuttgart · New York.

Th1 and Th2 help for B cells

DEFF Research Database (Denmark)

Poudrier, J; Owens, T

1995-01-01

that IL-5 (125 U/ml) synergizes with Th1 cells to induce B cell responses to IL-2, that are maintained following T-cell removal, e.g. autonomous. Th1 help in the absence of IL-5 resulted in weak or undetectable responses following T cell removal. The mechanism of IL-5 synergy involved persistence of IL-2R...... anti-Ig did not circumvent the need for IL-5 for autonomous IL-2 responses. Consistent with the above, interaction with an IL-5-producing Th2 clone induced strong autonomous B cell responses to IL-2. Qualitative differences of Th2 help over that of Th1 may thus be attributable to their differential...

Elevated chemokine CC-motif receptor-like 2 (CCRL2) promotes cell migration and invasion in glioblastoma.

Science.gov (United States)

Yin, Fengqiong; Xu, Zhenhua; Wang, Zifeng; Yao, Hong; Shen, Zan; Yu, Fang; Tang, Yiping; Fu, Dengli; Lin, Sheng; Lu, Gang; Kung, Hsiang-Fu; Poon, Wai Sang; Huang, Yunchao; Lin, Marie Chia-Mi

2012-12-14

Chemokine CC-motif receptor-like 2 (CCRL2) is a 7-transmembrane G protein-coupled receptor which plays a key role in lung dendritic cell trafficking to peripheral lymph nodes. The function and expression of CCRL2 in cancer is not understood at present. Here we report that CCRL2 expression level is elevated in human glioma patient samples and cell lines. The magnitude of increase is positively associated with increasing tumor grade, with the highest level observed in grade IV glioblastoma. By gain-of-function and loss-of-function studies, we further showed that CCRL2 did not regulate the growth of human glioblatoma U87 and U373 cells. Importantly, we demonstrated that over-expression of CCRL2 significantly enhanced the migration rate and invasiveness of the glioblastoma cells. Taken together, these results suggest for the first time that elevated CCRL2 in glioma promotes cell migration and invasion. The potential roles of CCRL2 as a novel therapeutic target and biomarker warrant further investigations. Copyright © 2012 Elsevier Inc. All rights reserved.

Heterogeneity of osteosarcoma cell lines led to variable responses in reprogramming.

Science.gov (United States)

Choong, Pei Feng; Teh, Hui Xin; Teoh, Hoon Koon; Ong, Han Kiat; Choo, Kong Bung; Sugii, Shigeki; Cheong, Soon Keng; Kamarul, Tunku

2014-01-01

Four osteosarcoma cell lines, Saos-2, MG-63, G-292 and U-2 OS, were reprogrammed to pluripotent state using Yamanaka factors retroviral transduction method. Embryonic stem cell (ESC)-like clusters started to appear between 15 to 20 days post transduction. Morphology of the colonies resembled that of ESC colonies with defined border and tightly-packed cells. The reprogrammed sarcomas expressed alkaline phosphatase and pluripotency markers, OCT4, SSEA4, TRA-1-60 and TRA-1-81, as in ESC up to Passage 15. All reprogrammed sarcomas could form embryoid body-like spheres when cultured in suspension in a low attachment dish for up to 10 days. Further testing on the directed differentiation capacity of the reprogrammed sarcomas showed all four reprogrammed sarcoma lines could differentiate into adipocytes while reprogrammed Saos-2-REP, MG-63-REP and G-292-REP could differentiate into osteocytes. Among the 4 osteosarcoma cell lines, U-2 OS reported the highest transduction efficiency but recorded the lowest reprogramming stability under long term culture. Thus, there may be intrinsic differences governing the variable responses of osteosarcoma cell lines towards reprogramming and long term culture effect of the reprogrammed cells. This is a first report to associate intrinsic factors in different osteosarcoma cell lines with variable reprogramming responses and effects on the reprogrammed cells after prolonged culture.

Heterogeneity of Osteosarcoma Cell Lines Led to Variable Responses in Reprogramming

Science.gov (United States)

Choong, Pei Feng; Teh, Hui Xin; Teoh, Hoon Koon; Ong, Han Kiat; Choo, Kong Bung; Sugii, Shigeki; Cheong, Soon Keng; Kamarul, Tunku

2014-01-01

Four osteosarcoma cell lines, Saos-2, MG-63, G-292 and U-2 OS, were reprogrammed to pluripotent state using Yamanaka factors retroviral transduction method. Embryonic stem cell (ESC)-like clusters started to appear between 15 to 20 days post transduction. Morphology of the colonies resembled that of ESC colonies with defined border and tightly-packed cells. The reprogrammed sarcomas expressed alkaline phosphatase and pluripotency markers, OCT4, SSEA4, TRA-1-60 and TRA-1-81, as in ESC up to Passage 15. All reprogrammed sarcomas could form embryoid body-like spheres when cultured in suspension in a low attachment dish for up to 10 days. Further testing on the directed differentiation capacity of the reprogrammed sarcomas showed all four reprogrammed sarcoma lines could differentiate into adipocytes while reprogrammed Saos-2-REP, MG-63-REP and G-292-REP could differentiate into osteocytes. Among the 4 osteosarcoma cell lines, U-2 OS reported the highest transduction efficiency but recorded the lowest reprogramming stability under long term culture. Thus, there may be intrinsic differences governing the variable responses of osteosarcoma cell lines towards reprogramming and long term culture effect of the reprogrammed cells. This is a first report to associate intrinsic factors in different osteosarcoma cell lines with variable reprogramming responses and effects on the reprogrammed cells after prolonged culture. PMID:25170299

Third-line Targeted Therapy in Metastatic Renal Cell Carcinoma: Results from the International Metastatic Renal Cell Carcinoma Database Consortium.

Science.gov (United States)

Wells, J Connor; Stukalin, Igor; Norton, Craig; Srinivas, Sandy; Lee, Jae Lyun; Donskov, Frede; Bjarnason, Georg A; Yamamoto, Haru; Beuselinck, Benoit; Rini, Brian I; Knox, Jennifer J; Agarwal, Neeraj; Ernst, D Scott; Pal, Sumanta K; Wood, Lori A; Bamias, Aristotelis; Alva, Ajjai S; Kanesvaran, Ravindran; Choueiri, Toni K; Heng, Daniel Y C

2017-02-01

The use of third-line targeted therapy (TTT) in metastatic renal cell carcinoma (mRCC) is not well characterized and varies due to the lack of robust data to guide treatment decisions. This study examined the use of third-line therapy in a large international population. To evaluate the use and efficacy of targeted therapy in a third-line setting. Twenty-five international cancer centers provided consecutive data on 4824 mRCC patients who were treated with an approved targeted therapy. One thousand and twelve patients (21%) received TTT and were included in the analysis. Patients were analyzed for overall survival (OS) and progression-free survival using Kaplan-Meier curves, and were evaluated for overall response. Cox regression analyses were used to determine the statistical association between OS and the six factors included in the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) prognostic model. Subgroup analysis was performed on patients stratified by their IMDC prognostic risk status. Everolimus was the most prevalent third-line therapy (27.5%), but sunitinib, sorafenib, pazopanib, temsirolimus, and axitinib were all utilized in over ≥9% of patients. Patients receiving any TTT had an OS of 12.4 mo, a progression-free survival of 3.9 mo, and 61.1% of patients experienced an overall response of stable disease or better. Patients not receiving TTT had an OS of 2.1 mo. Patients with favorable- (7.2%) or intermediate-risk (65.3%) disease had the highest OS with TTT, 29.9 mo and 15.5 mo, respectively, while poor-risk (27.5%) patients survived 5.5 mo. Results are limited by the retrospective nature of the study. TTT remains highly heterogeneous. The IMDC prognostic criteria can be used to stratify third-line patients. TTT use in favorable- and intermediate-risk patients was associated with the greatest OS. Patients with favorable- and intermediate-prognostic criteria disease treated with third-line targeted therapy have an associated

Global gene expression analysis of canine osteosarcoma stem cells reveals a novel role for COX-2 in tumour initiation.

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Pang, Lisa Y; Gatenby, Emma L; Kamida, Ayako; Whitelaw, Bruce A; Hupp, Ted R; Argyle, David J

2014-01-01

Osteosarcoma is the most common primary bone tumour of both children and dogs. It is an aggressive tumour in both species with a rapid clinical course leading ultimately to metastasis. In dogs and children distant metastasis occurs in >80% of individuals treated by surgery alone. Both canine and human osteosarcoma has been shown to contain a sub-population of cancer stem cells (CSCs), which may drive tumour growth, recurrence and metastasis, suggesting that naturally occurring canine osteosarcoma could act as a preclinical model for the human disease. Here we report the successful isolation of CSCs from primary canine osteosarcoma, as well as established cell lines. We show that these cells can form tumourspheres, and demonstrate relative resistance to chemotherapy. We demonstrate similar results for the human osteosarcma cell lines, U2OS and SAOS2. Utilizing the Affymetrix canine microarray, we are able to definitively show that there are significant differences in global gene expression profiles of isolated osteosarcoma stem cells and the daughter adherent cells. We identified 13,221 significant differences (p = 0.05), and significantly, COX-2 was expressed 141-fold more in CSC spheres than daughter adherent cells. To study the role of COX-2 expression in CSCs we utilized the COX-2 inhibitors meloxicam and mavacoxib. We found that COX-2 inhibition had no effect on CSC growth, or resistance to chemotherapy. However inhibition of COX-2 in daughter cells prevented sphere formation, indicating a potential significant role for COX-2 in tumour initiation.

Global gene expression analysis of canine osteosarcoma stem cells reveals a novel role for COX-2 in tumour initiation.

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Lisa Y Pang

Full Text Available Osteosarcoma is the most common primary bone tumour of both children and dogs. It is an aggressive tumour in both species with a rapid clinical course leading ultimately to metastasis. In dogs and children distant metastasis occurs in >80% of individuals treated by surgery alone. Both canine and human osteosarcoma has been shown to contain a sub-population of cancer stem cells (CSCs, which may drive tumour growth, recurrence and metastasis, suggesting that naturally occurring canine osteosarcoma could act as a preclinical model for the human disease. Here we report the successful isolation of CSCs from primary canine osteosarcoma, as well as established cell lines. We show that these cells can form tumourspheres, and demonstrate relative resistance to chemotherapy. We demonstrate similar results for the human osteosarcma cell lines, U2OS and SAOS2. Utilizing the Affymetrix canine microarray, we are able to definitively show that there are significant differences in global gene expression profiles of isolated osteosarcoma stem cells and the daughter adherent cells. We identified 13,221 significant differences (p = 0.05, and significantly, COX-2 was expressed 141-fold more in CSC spheres than daughter adherent cells. To study the role of COX-2 expression in CSCs we utilized the COX-2 inhibitors meloxicam and mavacoxib. We found that COX-2 inhibition had no effect on CSC growth, or resistance to chemotherapy. However inhibition of COX-2 in daughter cells prevented sphere formation, indicating a potential significant role for COX-2 in tumour initiation.

K{sub 2}NaOsO{sub 5.5} and K{sub 3}NaOs{sub 2}O{sub 9}: The first osmium perovskites containing alkali cations at the 'A' site

Energy Technology Data Exchange (ETDEWEB)

Mogare, Kailash M.; Klein, Wilhelm [Stuttgart, Max-Planck-Institut fuer Festkoerperforschung, Heisenbergstrasse 1, 70569 Stuttgart (Germany); Jansen, Martin, E-mail: M.Jansen@fkf.mpg.de [Stuttgart, Max-Planck-Institut fuer Festkoerperforschung, Heisenbergstrasse 1, 70569 Stuttgart (Germany)

2012-07-15

K{sub 2}NaOsO{sub 5.5} and K{sub 3}NaOs{sub 2}O{sub 9} were obtained from solid-state reactions of potassium superoxide, sodium peroxide and osmium metal at elevated oxygen pressures. K{sub 2}NaOsO{sub 5.5} crystallizes as an oxygen-deficient cubic double perovskite in space group Fm3{sup Macron }m with a=8.4184(5) A and contains isolated OsO{sub 6} octahedra. K{sub 3}NaOs{sub 2}O{sub 9} crystallizes hexagonally in P6{sub 3}/mmc with a=5.9998(4) A and c=14.3053(14) A. K{sub 3}NaOs{sub 2}O{sub 9} consists of face sharing Os{sub 2}O{sub 9} pairs of octahedra. According to magnetic measurements K{sub 2}NaOsO{sub 5.5} is diamagnetic, whereas K{sub 3}NaOs{sub 2}O{sub 9} displays strong antiferromagnetic coupling (T{sub N}=140 K), indicating enhanced magnetic interactions within the octahedral pair. - Graphical abstract: High oxidation states of Os, obtained by high oxygen pressure synthesis, are accommodated in double and triple perovskite matrices. K{sub 3}NaOs{sub 2}O{sub 9} displays enhanced magnetic interactions. Highlights: Black-Right-Pointing-Pointer New osmates containing highly oxidized Os were obtained by high O{sub 2} pressure synthesis. Black-Right-Pointing-Pointer High oxidation states of Os are accommodated in double and triple perovskite matrices. Black-Right-Pointing-Pointer Both compounds represent the first Os perovskites with an alkali metal at the A site. Black-Right-Pointing-Pointer K{sub 3}NaOs{sub 2}O{sub 9} displays enhanced magnetic interactions within the octahedral pair.

Simultaneous measurement of passage through the restriction point and MCM loading in single cells

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Håland, T. W.; Boye, E.; Stokke, T.; Grallert, B.; Syljuåsen, R. G.

2015-01-01

Passage through the Retinoblastoma protein (RB1)-dependent restriction point and the loading of minichromosome maintenance proteins (MCMs) are two crucial events in G1-phase that help maintain genome integrity. Deregulation of these processes can cause uncontrolled proliferation and cancer development. Both events have been extensively characterized individually, but their relative timing and inter-dependence remain less clear. Here, we describe a novel method to simultaneously measure MCM loading and passage through the restriction point. We exploit that the RB1 protein is anchored in G1-phase but is released when hyper-phosphorylated at the restriction point. After extracting cells with salt and detergent before fixation we can simultaneously measure, by flow cytometry, the loading of MCMs onto chromatin and RB1 binding to determine the order of the two events in individual cells. We have used this method to examine the relative timing of the two events in human cells. Whereas in BJ fibroblasts released from G0-phase MCM loading started mainly after the restriction point, in a significant fraction of exponentially growing BJ and U2OS osteosarcoma cells MCMs were loaded in G1-phase with RB1 anchored, demonstrating that MCM loading can also start before the restriction point. These results were supported by measurements in synchronized U2OS cells. PMID:26250117

Results of allogeneic stem cell transplantation in the Spanish MDS registry: prognostic factors for low risk patients.

Science.gov (United States)

Díez Campelo, M; Sánchez-Barba, M; de Soria, V Gómez-García; Martino, R; Sanz, G; Insunza, A; Bernal, T; Duarte, R; Amigo, M L; Xicoy, B; Tormo, M; Iniesta, F; Bailén, A; Benlloch, L; Córdoba, I; López-Villar, O; Del Cañizo, M C

2014-10-01

Although new agents have been approved for the treatment of MDS, the only curative approach is allogeneic hematopoietic stem cell transplantation (HSCT) and thus, in particular circumstances this procedure has been proposed as a treatment option for low risk patients. We have retrospectively analyzed the results of HSCT in 291 patients from the Spanish MDS registry with special attention to low risk MDS (LR-MDS) in order to define the variables that could impact their clinical evolution after transplantation. At 2 years OS was 51% and EFS was 50% (95% CI 0.7-4.5 years for OS and 95% CI 0.1-3.9 years for EFS). Among 43 LR-MDS, transplant-related mortality was 28%. At 3 years, OS was 67% (95% CI 264.7-8927.2 days for OS) and EFS was 64% (95% CI 0-9697.2 days for EFS). In the multivariate analysis only cytogenetics retained statistical significant effect on both OS (p=.047) and EFS (p=.046). Conditioning regimen could improve outcome among this subset of patients (OS 86% and RFS 100% for patients receiving RIC regimen). The present study confirms that specific disease characteristic as well as transplant characteristics have a significant impact on transplant outcome. Regarding low risk patients a non-myeloablative conditioning would be preferable especially in cases without high-risk cytogenetics. Copyright © 2014 Elsevier Ltd. All rights reserved.

[Cell-ELA-based determination of binding affinity of DNA aptamer against U87-EGFRvIII cell].

Science.gov (United States)

Tan, Yan; Liang, Huiyu; Wu, Xidong; Gao, Yubo; Zhang, Xingmei

2013-05-01

A15, a DNA aptamer with binding specificity for U87 glioma cells stably overexpressing the epidermal growth factor receptor variant III (U87-EGFRvIII), was generated by cell systematic evolution of ligands by exponential enrichment (cell-SELEX) using a random nucleotide library. Subsequently, we established a cell enzyme-linked assay (cell-ELA) to detect the affinity of A15 compared to an EGFR antibody. We used A15 as a detection probe and cultured U87-EGFRvIII cells as targets. Our data indicate that the equilibrium dissociation constants (K(d)) for A15 were below 100 nmol/L and had similar affinity compared to an EGFR antibody for U87-EGFRvIII. We demonstrated that the cell-ELA was a useful method to determine the equilibrium dissociation constants (K(d)) of aptamers generated by cell-SELEX.