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11 result(s) for "Dobias, Heidemarie"
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The efficacy of ferroptosis-inducing compounds IKE and RSL3 correlates with the expression of ferroptotic pathway regulators CD71 and SLC7A11 in biliary tract cancer cells
Biliary tract cancer (BTC) is a lethal disease with a bad overall survivability, partly arising from inadequate therapeutic alternatives, detection at a belated stage, and a resistance to common therapeutic approaches. Ferroptosis is a form of programmed cell death that depends on reactive oxygen species (ROS) and iron, causing excessive peroxidation of polyunsaturated fatty acids (PUFAs). Therefore, the objective of this investigation is, whether ferroptosis can be induced in BTC in vitro and whether this induction is dependent on specific molecular markers. The study conducted resazurin assay and IC25/50 calculation to explore the possible cytotoxic outcomes of different classes of ferroptosis-inducing substances (FINs) on a comprehensive in vitro model of 11 BTC cell lines. Combinatory treatments with different cell death inhibitors were performed to evaluate the magnitude of ferroptosis induction. To ascertain whether ferroptotic cell death occurred, liperfluo and iron assay kits were employed to evaluate lipid ROS and intracellular iron abundance. Potential biomarkers of ferroptosis sensitivity were then assessed via western blot analysis, a rtPCR panel and functional assay kits. The study found that different FINs reduced cell viability in a cell line-dependent manner. In addition, we measured increased lipid ROS and intracellular Fe2+ levels upon exposure to FINs in BTC cells. Combining FINs with inhibitors of ferroptosis, necroptosis or apoptosis suggests the occurrence of ferroptotic events in BTC cell lines CCC-5, HuH-28 and KKU-055. Furthermore, we found that BTC cells display a heterogeneous profile regarding different molecular genes/markers of ferroptosis. Subsequent analysis revealed that sensitivity of BTC cells towards IKE and RSL3 positively correlated with CD71 and SLC7A11 protein expression. Our results demonstrate that induction of ferroptosis is a promising approach to inhibit BTC cell growth and that the sensitivity of BTC cells towards ferroptosis induction might be dependent on molecular markers such as CD71 and SLC7A11.
Ouabain at nanomolar concentrations is cytotoxic for biliary tract cancer cells
Biliary tract cancer is a deadly disease with limited therapeutic options. Ouabain is a well-known inhibitor of the pumping function of Na + /K + -ATPase, though there is evidence that low concentrations of ouabain lead to a reduction of cell viability of cancer cells independent of its inhibition of the pumping function of the Na + /K + -ATPase. Regarding the impact of ouabain on biliary tract cancer, no data is currently available. Therefore, we aimed for a first-time investigation of ouabain as a potential anti-neoplastic biliary tract cancer agent using comprehensive human biliary tract cancer in vitro models. We found that ouabain has a strong cell line-dependent cytotoxic effect with IC 50 levels in the (low) nanomolar-range and that this effect was not associated with the mRNA expression levels of the Na + /K + -ATPase α , β and fxyd -subunits. Regarding the mode of cytotoxicity, we observed induction of apoptosis in biliary tract cancer cells upon treatment with ouabain. Interestingly, cytotoxic effects of ouabain at sub-saturating (< μM) levels were independent of cellular membrane depolarization and changes in intracellular sodium levels. Furthermore, using a 3D cell culture model, we found that ouabain disturbs spheroid growth and reduces the viability of biliary tract cancer cells within the tumor spheroids. In summary, our data suggest that ouabain possesses anti-biliary tract cancer potential at low μM-concentration in 2D and 3D in vitro biliary tract cancer models and encourage further detailed investigation.
Sustained improvements in EQ-5D utility scores and self-rated health status in patients with ankylosing spondylitis after spa treatment including low-dose radon – an analysis of prospective radon indication registry data
Background Patients with ankylosing spondylitis (AS) have significantly lower quality of life (QoL) than the general population. Holistic interventions addressing QoL comprise spa- or balneotherapy including radon. These interventions have shown to be beneficial in reducing pain and improving QoL in AS-patients. We explored the association of spa-therapy including low-dose radon with QoL in AS-patients over an extended time period. Methods Registry data collected for the “ Radon indication registry ” in the Austrian Gastein valley comprising data on QoL (EuroQol EQ-5D) directly before the treatment (baseline), directly(t1), 3 (t2); 6(t3) and 9(t4) months after the treatment, age, sex and body mass index (BMI) were analysed. Linear regression models explored the association of measurement time with 1) EQ-5D-5L utilities and 2) EuroQol visual analogue scale (VAS) score. Alterations of 0.05 (utilities) and 5.00 (VAS) were considered clinically relevant. Results Two-hundred-ninety-one AS-patients were included in the analyses. Forty-four percent ( n  = 128) were women, the mean age was 52 (SD 10) and the average BMI was 26 (SD 4). Utilities (t1: 0.09 [0.07;0.11]; t2: 0.08 [0.06; 0.10]; t3: 0.06 [0.05;0.09]; t4: 0.04 [0.02;0.06]) and VAS (t1: 11.68 [9.38; 13.97]; t2: 12.20 [9.78; 14.61]; t3: 9.70 [7.24; 12.17]; t4: 6.11 [3.57; 8.65]) were significantly higher at all timepoints compared to baseline. Improvements were clinically relevant at all timepoints in case of the VAS and until 6 months after treatment for the utilities. Conclusion AS-patients who received spa therapy including radon show significantly and clinically relevant improvements in Qol until 6–9 months after treatment.
Glycine Induces Migration of Microglial BV-2 Cells via SNAT-Mediated Cell Swelling
Background/Aims: The neutral, non-essential amino acid glycine has manifold functions and effects under physiological and pathophysiological conditions. Besides its function as a neurotransmitter in the central nervous system, glycine also exerts immunomodulatory effects and as an osmolyte it participates in cell volume regulation. During phagocytosis, glycine contributes to (local) cell volume-dependent processes like lamellipodium formation. Similar to the expansion of the lamellipodium we assume that glycine also affects the migration of microglial cells in a cell volume-dependent manner. Methods: Mean cell volume (MCV) and cell migration were determined using flow cytometry and trans-well migration assays, respectively. Electrophysiological recordings of the cell membrane potential (V mem ) and swelling-dependent chloride (Cl - ) currents (ICl swell , VSOR, VRAC) were performed using the whole-cell patch clamp technique. Results: In the murine microglial cell line BV-2, flow cytometry analysis revealed that glycine (5 mM) increases the MCV by ∼9%. The glycine-dependent increase in MCV was suppressed by the partial sodium-dependent neutral amino acid transporter (SNAT) antagonist MeAIB and augmented by the Cl - current blocker DCPIB. Electrophysiological recordings showed that addition of glycine activates a Cl - current under isotonic conditions resembling features of the swelling-activated Cl - current (ICl swell ). The cell membrane potential (V mem ) displayed a distinctive time course after glycine application; initially, glycine evoked a rapid depolarization mediated by Na + -coupled glycine uptake via SNAT, followed by a further gradual depolarization, which was fully suppressed by DCPIB. Interestingly, glycine significantly increased migration of BV-2 cells, which was suppressed by MeAIB, suggesting that SNAT is involved in the migration process of microglial cells. Conclusion: We conclude that glycine acts as a chemoattractant for microglial cells presumably by a cell volume-dependent mechanism involving SNAT-mediated cell swelling.
Evaluation of Tazemetostat as a Therapeutically Relevant Substance in Biliary Tract Cancer
Biliary tract cancer (BTC) is a gastrointestinal malignancy associated with a poor survival rate. Current therapies encompass palliative and chemotherapeutic treatment as well as radiation therapy, which results in a median survival of only one year due to standard therapeutic ineffectiveness or resistance. Tazemetostat is an FDA-approved inhibitor of enhancer of Zeste homolog 2 (EZH2), a methyltransferase involved in BTC tumorigenesis via trimethylation of histone 3 at lysine 27 (H3K27me3), an epigenetic mark associated with silencing of tumor suppressor genes. Up to now, there are no data available regarding tazemetostat as a possible treatment option against BTC. Therefore, the aim of our study is a first-time investigation of tazemetostat as a potential anti-BTC substance in vitro. In this study, we demonstrate that tazemetostat affects cell viability and the clonogenic growth of BTC cells in a cell line-dependent manner. Furthermore, we found a strong epigenetic effect at low concentrations of tazemetostat, which was independent of the cytotoxic effect. We also observed in one BTC cell line that tazemetostat increases the mRNA levels and protein expression of the tumor suppressor gene Fructose-1,6-bisphosphatase 1 (FBP1). Interestingly, the observed cytotoxic and epigenetic effects were independent of the mutation status of EZH2. To conclude, our study shows that tazemetostat is a potential anti-tumorigenic substance in BTC with a strong epigenetic effect.
HDAC Screening Identifies the HDAC Class I Inhibitor Romidepsin as a Promising Epigenetic Drug for Biliary Tract Cancer
Inhibition of histone deacetylases (HDACs) is a promising anti-cancer approach. For biliary tract cancer (BTC), only limited therapeutic options are currently available. Therefore, we performed a comprehensive investigation of HDAC expression and pharmacological HDAC inhibition into a panel of eight established BTC cell lines. The screening results indicate a heterogeneous expression of HDACs across the studied cell lines. We next tested the effect of six established HDAC inhibitors (HDACi) covering pan- and class-specific HDACis on cell viability of BTC cells and found that the effect (i) is dose- and cell-line-dependent, (ii) does not correlate with HDAC isoform expression, and (iii) is most pronounced for romidepsin (a class I HDACi), showing the highest reduction in cell viability with IC50 values in the low-nM range. Further analyses demonstrated that romidepsin induces apoptosis in BTC cells, reduces HDAC activity, and increases acetylation of histone 3 lysine 9 (H3K9Ac). Similar to BTC cell lines, HDAC 1/2 proteins were heterogeneously expressed in a cohort of resected BTC specimens (n = 78), and their expression increased with tumor grading. The survival of BTC patients with high HDAC-2-expressing tumors was significantly shorter. In conclusion, HDAC class I inhibition in BTC cells by romidepsin is highly effective in vitro and encourages further in vivo evaluation in BTC. In situ assessment of HDAC 2 expression in BTC specimens indicates its importance for oncogenesis and/or progression of BTC as well as for the prognosis of BTC patients.
Miniaturization of the Clonogenic Assay Using Confluence Measurement
The clonogenic assay is a widely used method to study the ability of cells to ‘infinitely’ produce progeny and is, therefore, used as a tool in tumor biology to measure tumor-initiating capacity and stem cell status. However, the standard protocol of using 6-well plates has several disadvantages. By miniaturizing the assay to a 96-well microplate format, as well as by utilizing the confluence detection function of a multimode reader, we here describe a new and modified protocol that allows comprehensive experimental setups and a non-endpoint, label-free semi-automatic analysis. Comparison of bright field images with confluence images demonstrated robust and reproducible detection of clones by the confluence detection function. Moreover, time-resolved non-endpoint confluence measurement of the same well showed that semi-automatic analysis was suitable for determining the mean size and colony number. By treating cells with an inhibitor of clonogenic growth (PTC-209), we show that our modified protocol is suitable for comprehensive (broad concentration range, addition of technical replicates) concentration- and time-resolved analysis of the effect of substances or treatments on clonogenic growth. In summary, this protocol represents a time- and cost-effective alternative to the commonly used 6-well protocol (with endpoint staining) and also provides additional information about the kinetics of clonogenic growth.
Acute Exposure to Environmental Tobacco Smoke: A Controlled Study in Adults with Asthma
Background: Short-term, indoor exposure to environmental tobacco smoke (ETS) is still highly prevalent; however, little is known about the acute lung response in adult asthma. Objectives: We investigated whether acute, experimental ETS exposure influences symptoms, lung function, and inflammatory parameters. Methods: Human subjects with asthma (n = 23) were exposed for 180 min to either room air or ETS at 250, 450, or 850 µg/m 3 . Respiratory symptoms, lung function, and exhaled nitric oxide (FeNO) were measured. Additionally, blood samples were analyzed for pro- and anti-inflammatory cytokines. Results: Humans with asthma demonstrate an increase in respiratory symptoms at all levels of ETS exposure, while the forced expiratory volume in 1 s (FEV 1 ) and FeNO decrease with increasing ETS. The anti-inflammatory cytokine interleukin (IL)-10 increases at intermediate ETS concentrations, whereas tumor necrosis factor (TNF)-α and IL-8 increase only at the highest ETS concentration. Conclusion: Following 180 min of acute, experimental ETS exposure, we observed a significant increase in respiratory symptoms, a decrease in lung function, and an increase in inflammatory cytokines, indicating an acute lung response in asthma.
Ouabain at nanomolar concentrations is cytotoxic for biliary tract cancer cells
Biliary tract cancer is a deadly disease with limited therapeutic options. Ouabain is a well-known inhibitor of the pumping function of Na+/K+-ATPase, though there is evidence that low concentrations of ouabain lead to a reduction of cell viability of cancer cells independent of its inhibition of the pumping function of the Na+/K+-ATPase. Regarding the impact of ouabain on biliary tract cancer, no data is currently available. Therefore, we aimed for a first-time investigation of ouabain as a potential anti-neoplastic biliary tract cancer agent using comprehensive human biliary tract cancer in vitro models. We found that ouabain has a strong cell line-dependent cytotoxic effect with IC50 levels in the (low) nanomolar-range and that this effect was not associated with the mRNA expression levels of the Na+/K+-ATPase α, β and fxyd-subunits. Regarding the mode of cytotoxicity, we observed induction of apoptosis in biliary tract cancer cells upon treatment with ouabain. Interestingly, cytotoxic effects of ouabain at sub-saturating (< μM) levels were independent of cellular membrane depolarization and changes in intracellular sodium levels. Furthermore, using a 3D cell culture model, we found that ouabain disturbs spheroid growth and reduces the viability of biliary tract cancer cells within the tumor spheroids. In summary, our data suggest that ouabain possesses anti-biliary tract cancer potential at low μM-concentration in 2D and 3D in vitro biliary tract cancer models and encourage further detailed investigation.
Radon therapy ameliorates disease progression and prolongs survival in TNF alpha tg mice
Backgroundand objectives Radon therapy as alternative therapy for rheumatic diseases in curative tunnels such as the Heilstollen Bad Gastein in Austria has been reported to reduce pain and amount of drug usage. Inhaled radon remains in the body as decaying radioactive radon progeny, and exhibits analgesic, anti-inflammatory and immune stimulating effects. In the Heilstollen the patients usually receive mean radon doses of 44 000 Bq/m3 air (dependent on the weather conditions). Placebo effects (caused by excitement, caring by the physicians, relaxations during treatment) are discussed to contribute to clinical improvement of rheumatic diseases. To exclude placebo effects the authors analysed benefits of the radon therapy in an animal experiment performed under controlled conditions. Mice over-expressing human tumour necrosis factor α (TNFα) that develop polyarthritis served as animal model for rheumatoid arthritis. Materials and methods Gaseous radon from water of radon galleries of Bad Gastein, Austria, was prepared using an evaporation system. In addition to the breathing air the drinking water of the animals contained radon. The dosimetry was performed by liquid scintillation with radon enrichment on an activated carbon matrix. TNF tg (n=10) and wild type (n=7) mice were 12 x exposed to radon in 3 weeks for 3 h per day. Mock treated TNF tg (n=11) and wild type mice (n=7) served as controls. The course of the disease was monitored by measurements of body weight, grip strength and mortality. All analyses were performed by two researchers blinded to the treatment conditions the mice had received. Results The mean daily radon doses applied to the mice were 119213±39113 Bq/m3 by inhalation. The drinking water contained 800-900 Bq/l. TNF tg mice showed severe illness marked by reduced body weight and decreasing grip strength compared to wild type controls. After treatment with radon TNF tg mice showed an improved body constitution and movement activity, measured by body weight and grip strength. Improvements continued until death of the mice. Interestingly, the TNF tg mice treated with radon showed an increased survival compared to mock treated TNF tg control mice. Conclusions Radon therapy ameliorates the inflammatory processes responsible for the arthritogenic activity of human TNF in mice. The overall radon dose applied to the mice is in the same range as during the treatment of patients in the Heilstollen Bad Gastein/Austria.