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TXRF és ICP-MS mikroanalitikai módszerek fejlesztése esszenciális és nyomelemek meghatározására emberi biopsziás mintákban = Development of TXRF and ICP-MS microanalytical methods for determination of essential trace elements in human biopsy samples

TXRF és ICP-MS mikroanalitikai módszerek fejlesztése esszenciális és nyomelemek meghatározására emberi biopsziás mintákban: Az elemek eloszlásának összehasonlító vizsgálatát végeztük el emberi máj biopsziás mintákban totál reflexiós röntgenfluoreszcencia spektrometria (TXRF) és induktív csatolású plazma tömegspektrometria (ICP-MS) segítségével. Méréseink alapján feltételezhető az összefüggés a májbeli nikkel akkumuláció és a steatosis között. A vas koncentráció szignifikáns csökkenését szintén tapasztaltuk steatosis esetén. TXRF spektromertia alkalmazásával meghatároztuk DTPA coportot tartamazó nociceptin derivátumok In3+ kötőképességét. Extrakciós eljárásokat és TXRF spektrometriai módszert fejlesztettünk jód meghatározására biológiai mintákban. | Development of TXRF and ICP-MS microanalytical methods for determination of essential and trace elements in human biopsy samples: A comparative study on elemental distribution was performed on a series of percutaneous human liver biopsy samples using total reflection X-ray fluorescence (TXRF) and inductively coupled plasma mass spectrometry (ICP-MS). Our measurements revealed a probable correlation between hepatic nickel accumulation and steatosis. Decreased iron concentration was also observed in the group of patients with steatosis. TXRF spectrometry was applied to determine In3+ chelating properties of nociceptin derivatives containing DTPA group. Extraction procedure and analytical method based on TXRF spectrometry was developed for determination of iodine in biological matrices

A bioenergetikai profil vizsgálata 14C-glükóz és 14C-acetát oxidációjának összehasonlításával tumorsejtekben és tumoros szervezetben

A tumorsejtek anyagcseréjét a változó mikrokörnyezeti tényezõk mellett a tumornövekedést támogató genetikai mechanizmusok is befolyásolják. Napjainkban egyre nagyobb az igény a humán tumorok terápiás válaszreakcióinak vagy metabolikus profiljukra épülõ szubtípusainak vizsgálatára. A tumorsejtek és a tumort hordozó gazdaszervezet metabolikus/bioenergetikai jellegének tájékozódó igényû tanulmányozására alkalmas módszernek tartható a 14C-glükóz és 14C-acetát oxidációjának vizsgálata. Munkánkban radioaktívan jelölt bioenergetikai szubsztrátokból felszabaduló CO2 meghatározásával a tumorsejtek (in vitro sejtvonalak, illetve primer humán lymphocyták és leukaemiasejtek) és a tumoros szervezet (SCID, C57Bl/6) metabolikus aktivitását vizsgáltuk in vitro és in vivo. Megállapítottuk, hogy a szolid tumorból származó tumorsejtek többsége fokozottabban oxidálja a glükózt, mint az acetátot, míg a vérbõl izolált AML-, CML- és CLL-sejtek az acetátot oxidálták nagyobb mértékben, mint a glükózt in vitro. In vivo vizsgálatainkban azt tapasztaltuk, hogy a bioenergetikai szubsztrátok intravénás vagy per os adagolásakor kimutatható a tumorok hatása a gazdaszervezet glükóz-, illetve acetátoxidációjára. Elsõ adatot szolgáltattunk az emberi tumort hordozó gazdaszervezetek metabolikus profiljának változásáról xenograft modellen. Összefoglalva, eredményeink szerint több bioenergetikai szubsztrát oxidációjának összehasonlítása informatív módszer lehet a tumorsejtek in vitro, illetve a tumorok és a gazdaszervezet in vivo metabolikus profiljának vizsgálatában

An 8-hydroxyquinoline–proline hybrid with multidrug resistance reversal activity and the solution chemistry of its half-sandwich organometallic Ru and Rh complexes

Herein the design and synthesis of a new 8-hydroxyquinoline derivative, (S)-5-chloro-7-((proline-1-yl)methyl)8-hydroxyquinoline (HQCl-Pro), with good water solubility and multidrug resistance reversal activity are reported. In this work the proton dissociation processes of HQCl-Pro and its complex formation with [Rh(η5-C5Me5)(H2O)3]2+, [Ru(η6-p-cymene)(H2O)3]2+and [Ru(η6-toluene)(H2O)3]2+were investigated by the combined use of pH-potentiometry, UV-visible spectrometry and1H NMR spectroscopy. Our results revealed the prominent solution stability of the complexes in all cases. The lipophilicity of the complexes increased with the chloride ion concentration, and the complexes showed moderate log Dvalues (−0.8 to +0.4) at pH 7.4 at all tested Cl−concentrations. The formation of mixed hydroxido complexes from the aqua complexes was characterized by relatively high pKavalues (8.45-9.62 in chloride-free medium). Complexation processes are much slower with the Ru(η6-arene) triaqua cations than with [Rh(η5-C5Me5)(H2O)3]2+. Both the pKavalues and H2O/Cl−exchange constants of the Ru-complexes are lower by 0.5-1.0 orders of magnitude than those of the Rh analogue. Arene loss (p-cymene and toluene) and oxidation were found in the case of Ru-complexes when an excess of HQCl-Pro and aromatic (N,N) bidentate ligands was added. The cytotoxicity and antiproliferative effect of HQCl-Pro and its complexes were assayedin vitro. In contrast to the structurally familiar 8-hydroxyquinoline, HQCl-Pro and its Rh(η5-C5Me5) complex were somewhat more effective against drug resistant Colo 320 adenocarcinoma human cells compared to the drug sensitive Colo 205 cells. The Ru- and Rh-complexes showed a similar metal uptake level after 4 h, while a longer incubation time resulted in higher cellular Rh concentration

MEK1 is associated with carboplatin resistance and is a prognostic biomarker in epithelial ovarian cancer

BACKGROUND: Primary systemic treatment for ovarian cancer is surgery, followed by platinum based chemotherapy. Platinum resistant cancers progress/recur in approximately 25% of cases within six months. We aimed to identify clinically useful biomarkers of platinum resistance. METHODS: A database of ovarian cancer transcriptomic datasets including treatment and response information was set up by mining the GEO and TCGA repositories. Receiver operator characteristics (ROC) analysis was performed in R for each gene and these were then ranked using their achieved area under the curve (AUC) values. The most significant candidates were selected and in vitro functionally evaluated in four epithelial ovarian cancer cell lines (SKOV-3-, CAOV-3, ES-2 and OVCAR-3), using gene silencing combined with drug treatment in viability and apoptosis assays. We collected 94 tumor samples and the strongest candidate was validated by IHC and qRT-PCR in these. RESULTS: All together 1,452 eligible patients were identified. Based on the ROC analysis the eight most significant genes were JRK, CNOT8, RTF1, CCT3, NFAT2CIP, MEK1, FUBP1 and CSDE1. Silencing of MEK1, CSDE1, CNOT8 and RTF1, and pharmacological inhibition of MEK1 caused significant sensitization in the cell lines. Of the eight genes, JRK (p = 3.2E-05), MEK1 (p = 0.0078), FUBP1 (p = 0.014) and CNOT8 (p = 0.00022) also correlated to progression free survival. The correlation between the best biomarker candidate MEK1 and survival was validated in two independent cohorts by qRT-PCR (n = 34, HR = 5.8, p = 0.003) and IHC (n = 59, HR = 4.3, p = 0.033). CONCLUSION: We identified MEK1 as a promising prognostic biomarker candidate correlated to response to platinum based chemotherapy in ovarian cancer

Rapamycin (mTORC1 inhibitor) reduces the production of lactate and 2-hydroxyglutarate oncometabolites in IDH1 mutant fibrosarcoma cells

Background Multiple studies concluded that oncometabolites (e.g. D-2-hydroxyglutarate (2-HG) related to mutant isocitrate dehydrogenase 1/2 (IDH1/2) and lactate) have tumour promoting potential. Regulatory mechanisms implicated in the maintenance of oncometabolite production have great interest. mTOR (mammalian target of rapamycin) orchestrates different pathways, influences cellular growth and metabolism. Considering hyperactivation of mTOR in several malignancies, the question has been addressed whether mTOR operates through controlling of oncometabolite accumulation in metabolic reprogramming. Methods HT-1080 cells – carrying originally endogenous IDH1 mutation – were used in vitro and in vivo. Anti-tumour effects of rapamycin were studied using different assays. The main sources and productions of the oncometabolites (2-HG and lactate) were analysed by 13C-labeled substrates. Alterations at protein and metabolite levels were followed by Western blot, flow cytometry, immunohistochemistry and liquid chromatography mass spectrometry using rapamycin, PP242 and different glutaminase inhibitors, as well. Results Rapamycin (mTORC1 inhibitor) inhibited proliferation, migration and altered the metabolic activity of IDH1 mutant HT-1080 cells. Rapamycin reduced the level of 2-HG sourced mainly from glutamine and glucose derived lactate which correlated to the decreased incorporation of 13C atoms from 13C-substrates. Additionally, decreased expressions of lactate dehydrogenase A and glutaminase were also observed both in vitro and in vivo. Conclusions Considering the role of lactate and 2-HG in regulatory network and in metabolic symbiosis it could be assumed that mTOR inhibitors have additional effects besides their anti-proliferative effects in tumours with glycolytic phenotype, especially in case of IDH1 mutation (e.g. acute myeloid leukemias, gliomas, chondrosarcomas). Based on our new results, we suggest targeting mTOR activity depending on the metabolic and besides molecular genetic phenotype of tumours to increase the success of therapies

GABA, glutamine, glutamate oxidation and succinic semialdehyde dehydrogenase expression in human gliomas

Bioenergetic characterisation of malignant tissues revealed that different tumour cells can catabolise multiple substrates as salvage pathways, in response to metabolic stress. Altered metabolism in gliomas has received a lot of attention, especially in relation to IDH mutations, and the associated oncometabolite D-2-hydroxyglutarate (2-HG) that impact on metabolism, epigenetics and redox status. Astrocytomas and oligodendrogliomas, collectively called diffuse gliomas, are derived from astrocytes and oligodendrocytes that are in metabolic symbiosis with neurons; astrocytes can catabolise neuron-derived glutamate and gamma-aminobutyric acid (GABA) for supporting and regulating neuronal functions.Metabolic characteristics of human glioma cell models - including mitochondrial function, glycolytic pathway and energy substrate oxidation - in relation to IDH mutation status and after 2-HG incubation were studied to understand the Janus-faced role of IDH1 mutations in the progression of gliomas/astrocytomas. The metabolic and bioenergetic features were identified in glioma cells using wild-type and genetically engineered IDH1-mutant glioblastoma cell lines by metabolic analyses with Seahorse, protein expression studies and liquid chromatography-mass spectrometry.U251 glioma cells were characterised by high levels of glutamine, glutamate and GABA oxidation. Succinic semialdehyde dehydrogenase (SSADH) expression was correlated to GABA oxidation. GABA addition to glioma cells increased proliferation rates. Expression of mutated IDH1 and treatment with 2-HG reduced glutamine and GABA oxidation, diminished the pro-proliferative effect of GABA in SSADH expressing cells. SSADH protein overexpression was found in almost all studied human cases with no significant association between SSADH expression and clinicopathological parameters (e.g. IDH mutation).Our findings demonstrate that SSADH expression may participate in the oxidation and/or consumption of GABA in gliomas, furthermore, GABA oxidation capacity may contribute to proliferation and worse prognosis of gliomas. Moreover, IDH mutation and 2-HG production inhibit GABA oxidation in glioma cells. Based on these data, GABA oxidation and SSADH activity could be additional therapeutic targets in gliomas/glioblastomas

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