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1.
Epithelial ovarian carcinoma (EOC), the major cause of gynaecological cancer death, is a heterogeneous disease classified into five subtypes. Each subtype has distinct clinical characteristics and is associated with different genetic risk factors and molecular events, but all are treated with surgery and platinum/taxane regimes. Tumour progression and chemoresistance is generally associated with major metabolic alterations, notably altered mitochondrial function(s). Here, we report for the first time that the expression of the mitochondrial regulators PGC1α and TFAM varies between EOC subtypes; furthermore, we have identified a profile in clear-cell carcinoma consisting of undetectability of PGC1α/TFAM, and low ERα/Ki-67. By contrast, high-grade serous carcinomas were characterised by a converse state of PGC1α/TFAM, ERα positivity and a high Ki-67 index. Interestingly, loss of PGC1α/TFAM and ERα was found also in a non-clear cell EOC cell line made highly resistant to platinum in vitro. Similar to clear-cell carcinomas, these resistant cells also showed accumulation of glycogen. Altogether, our data provide mechanistic insights into the chemoresistant nature of ovarian clear-cell carcinomas. Furthermore, these findings corroborate the need to take into account the diversity of EOC and to develop subtype specific treatment strategies. 相似文献
2.
The influence of hypomagnesemia on erythrocyte antioxidant enzyme defence system in mice 总被引:2,自引:1,他引:1
Andrzej Kuzniar Przemyslaw Mitura Piotr Kurys Stanislawa Szymonik-Lesiuk Boleslaw Florianczyk Marta Stryjecka-Zimmer 《Biometals》2003,16(2):349-357
The effect of magnesium deficiency on antioxidant defence system was studied in RBC of mice suffering from hypomagnesemia. The animals were kept for 8, 15 and 22 days on magnesium-deficient diet with consequent reduction of magnesium level in plasma by 38% at the first 8 days and by 64% after 22 days of experiment. The activities of the most important antioxidant enzymes, catalase, glutathione peroxidase, superoxide dismutase, glutathione reductase, glutahione S-transferase were assayed in hemolysates. The level of reduced glutathione in erythrocytes was measured as well. Apart from catalase, the activities of antioxidant enzymes were decreasing. The activity of superoxide dismutase decreased gradually during the experiment and on the 15th and 22nd day of experiment was significantly (P<0,05) lowered by 30 and 32% respectively. The catalase activity was increased on each point of the experiment with the peak value up to 149% on 15th day, and by 32% on 22nd day. Glutathione peroxidase activity was insignificantly reduced. The reduction of Glutatione reductase and Glutathione S-transferase activities by 24 and 21%, respectively, were observed after 8 days of the experiment with a further downward tendency. The reduced glutathione was significantly depleted after 8 days by 33% and was kept on that level in the course of the study. These findings support previous reports on the hypomagnesemia – induced alteration in endogenous enzyme antioxidant defences and glutathione redox cycle of mice. 相似文献
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Andrzej Pḱlonka Diana Metodiewa Alojzy Zgirski Maria Hilewicz Wanda Leyko 《Biochemical and biophysical research communications》1980,95(3):978-984
The formation of the paramagnetic complex between human ceruloplasmin and radiation produced superoxide radicals was observed by the ESR method at low temperatures. The disappearance of the complex without changes in the oxidation state of copper give the direct evidence that ceruloplasmin, the major antioxidant in serum, is able to dismutate superoxide radicals. 相似文献
5.
Piotr Politański Elźbieta Rajkowska Marcin Brodecki Andrzej Bednarek Marek Zmyślony 《Bioelectromagnetics》2013,34(4):333-336
The aim of this study was to investigate the effect of static magnetic fields (SMF) on reactive oxygen species induced by X‐ray radiation. The experiments were performed on lymphocytes from male albino Wistar rats. After exposure to 3 Gy X‐ray radiation (with a dose rate of 560 mGy/min) the measurement of intracellular reactive oxygen species in lymphocytes, using a fluorescent probe, was done before exposure to the SMF, and after 15 min, 1 and 2 h of exposure to the SMF or a corresponding incubation time. For SMF exposure, 0 mT (50 µT magnetic field induction opposite to the geomagnetic field) and 5 mT fields were chosen. The trend of SMF effects for 0 mT was always opposite that of 5 mT. The first one decreased the rate of fluorescence change, while the latter one increased it. Bioelectromagnetics 34:333–336, 2013. © 2012 Wiley Periodicals, Inc. 相似文献
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Anna Nowakowska-Waszczuk Andrzej Sokoŀowski 《Applied microbiology and biotechnology》1987,26(4):363-364
Summary In an air-lift fermenter, the following production was obtained from 125 g sucrose in mineral medium at pH 2.5 : 15.76 g mycelium dry wt, 107.2 g citric acid anhydrous and 0.594 mol CO2 within 138 h (run I) and 13.72 g mycelium dry wt, 114.28 g citric acid and 0.516 mol CO2 within 144 h (run II). Initially, the carbon content of consumed sugar and products did not balance. At the end of fermentation, the carbon content of the products was 0.9%–5.5% higher than that of the consumed sugar. For the purpose of the calculations the carbon content in mycelium was accepted as 0.462.The work was a part of Project No 04.11 CPBP, topic No 2.24 相似文献
9.
When cells are briefly exposed to cis-diamminedichloroplatinum (II) before lysis in high sodium dodecyl sulfate-urea solutions, the high molecular-weight nucleic acids pelleted by ultracentrifugation contain an increased level of bound proteins when compared to a similar fraction from untreated cells. Subsequent shearing of the pelleted DNA followed by treatment with DNase permits electrophoretic and immunoblot analysis of the crosslinked proteins. In the present study such experiments were carried out with reference to nuclear envelope pore complex proteins in the differentiating L8 rat skeletal muscle cells. The results show that (i) whereas the major lamin proteins crosslinked to DNA in both myoblast and myotubes, lamin B is crosslinked to a greater extent to DNA in myotubes; (ii) a 62-kDa lectin-binding glycoprotein is apparently situated differently with respect to DNA in myotube nuclei; and (iii) the crosslinking pattern of the nuclear matrix proteins to DNA is qualitatively similar in myoblast and myotubes. In addition, lamin C′, a modified form of lamin C, not observed in intact nonmuscle cells previously [[31.] J. Biol. Chem. 260, 1895–1900], exists as a native component of the nuclear lamina in rat skeletal myotubes but not in myoblasts. These results point to significant structural alterations in the proteins of the nuclear lamina-pore complex during myogenesis. 相似文献
10.
Improvement in stability of an immobilized fungal laccase 总被引:4,自引:0,他引:4
Andrzej Leonowicz Jawed M. Sarkar Jean-Marc Bollag 《Applied microbiology and biotechnology》1988,29(2-3):129-135
Summary A laccase of the basidiomyceteTrametes versicolor was immobilized on porous glass beads that were activated with 3-aminopropyltriethoxysilane and glutaraldehyde. The support immobilized 100% of the enzyme, whereupon 90% of the original activity was retained. After immobilization, the enzyme was active in a wider pH and temperature range, and its heat stability and reuse were greatly improved compared to those of the free laccase. The immobilized enzyme was found reusable in treating different substrates, either recycled alone or in a sequential order. 相似文献