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Sample records for inhibition tumour hypoxia

  1. Alterations of monocarboxylate transporter densities during hypoxia in brain and breast tumour cells

    Cheng, Chang; Edin, Nina F Jeppesen; Lauritzen, Knut H

    2012-01-01

    Tumour cells are characterized by aerobic glycolysis, which provides biomass for tumour proliferation and leads to extracellular acidification through efflux of lactate via monocarboxylate transporters (MCTs). Deficient and spasm-prone tumour vasculature causes variable hypoxia, which favours...

  2. Prodrugs designed to discriminate pathological (tumour) and physiological (normal tissue) hypoxia

    Wilson, W.R.; Patterson, A.V.

    2003-01-01

    There is now abundant evidence that hypoxic contributes to treatment failure in radiation therapy. As a target for therapeutic intervention, hypoxia is especially attractive because it is a common feature of most human tumours and therefore a potential 'pan target' across many tumour types. However, attempts to exploit hypoxia face the problem that oxygen concentrations in some normal tissues are also heterogeneous and that O 2 distributions in tumours and normal tissues overlap. Simply adjusting the K value (O 2 concentration for 50% inhibition of activation) does not provide a satisfactory solution. Bioreductive drugs like tirapazamine with high K values are activated significantly in several normal tissues, while nitro compounds and quinones with low K values spare the hypoxic tumour cells at 'intermediate' O 2 tensions (1-10 mM O 2 ) which are considered to be major contributors to tumour radioresistance. A potential strategy for overcoming this dilemma is to design prodrugs that are activated only at very low K values, but give relatively stable cytotoxic metabolites capable of diffusing to cells at higher O 2 concentrations. This approach redefines the therapeutic target as cells adjacent to zones of pathological hypoxia ( 2 ), providing discrimination from physiological hypoxia in normal tissues. Detecting bioreductive prodrugs capable of providing bystander killing of this kind is not straightforward. We have adapted a multicellular layer (MCL) co-culture model for quantifying bystander effects in GDEPT (Wilson et al., Cancer Res., 62: 1425-1432, 2002), and have used this to measure bystander effects of hypoxia-activated prodrugs. This model uses differences in metabolic activation of bioreductive drugs between A459 cell lines with low and high cytochrome P450 reductase activity, rather than O 2 gradients, to effect localised prodrug activation. It shows that TPZ and the nitroimidazole RSU-1069 have little or no bystander effect, but that dinitrobenzamide

  3. Significance of manipulating tumour hypoxia and radiation dose rate in terms of local tumour response and lung metastatic potential, referring to the response of quiescent cell populations

    Masunaga, S; Matsumoto, Y; Kashino, G; Hirayama, R; Liu, Y; Tanaka, H; Sakurai, Y; Suzuki, M; Kinashi, Y; Maruhashi, A; Ono, K

    2010-01-01

    The purpose of this study was to evaluate the influence of manipulating intratumour oxygenation status and radiation dose rate on local tumour response and lung metastases following radiotherapy, referring to the response of quiescent cell populations within irradiated tumours. B16-BL6 melanoma tumour-bearing C57BL/6 mice were continuously given 5-bromo-2′-deoxyuridine (BrdU) to label all proliferating (P) cells. They received γ-ray irradiation at high dose rate (HDR) or reduced dose rate (RDR) following treatment with the acute hypoxia-releasing agent nicotinamide or local hyperthermia at mild temperatures (MTH). Immediately after the irradiation, cells from some tumours were isolated and incubated with a cytokinesis blocker. The responses of the quiescent (Q) and total (proliferating + Q) cell populations were assessed based on the frequency of micronuclei using immunofluorescence staining for BrdU. In other tumour-bearing mice, 17 days after irradiation, macroscopic lung metastases were enumerated. Following HDR irradiation, nicotinamide and MTH enhanced the sensitivity of the total and Q-cell populations, respectively. The decrease in sensitivity at RDR irradiation compared with HDR irradiation was slightly inhibited by MTH, especially in Q cells. Without γ-ray irradiation, nicotinamide treatment tended to reduce the number of lung metastases. With γ-rays, in combination with nicotinamide or MTH, especially the former, HDR irradiation decreased the number of metastases more remarkably than RDR irradiation. Manipulating both tumour hypoxia and irradiation dose rate have the potential to influence lung metastasis. The combination with the acute hypoxia-releasing agent nicotinamide may be more promising in HDR than RDR irradiation in terms of reducing the number of lung metastases. PMID:20739345

  4. Hypoxia Enhances Immunosuppression by Inhibiting CD4+ Effector T Cell Function and Promoting Treg Activity

    Astrid M. Westendorf

    2017-03-01

    Full Text Available Background/Aims: Hypoxia occurs in many pathological conditions, including inflammation and cancer. Within this context, hypoxia was shown to inhibit but also to promote T cell responses. Due to this controversial function, we aimed to explore whether an insufficient anti-tumour response during colitis-associated colon cancer could be ascribed to a hypoxic microenvironment. Methods: Colitis-associated colon cancer was induced in wildtype mice, and hypoxia as well as T cell immunity were analysed in the colonic tumour tissues. In addition, CD4+ effector T cells and regulatory T cells were cultured under normoxic and hypoxic conditions and examined regarding their phenotype and function. Results: We observed severe hypoxia in the colon of mice suffering from colitis-associated colon cancer that was accompanied by a reduced differentiation of CD4+ effector T cells and an enhanced number and suppressive activity of regulatory T cells. Complementary ex vivo and in vitro studies revealed that T cell stimulation under hypoxic conditions inhibited the differentiation, proliferation and IFN-γ production of TH1 cells and enhanced the suppressive capacity of regulatory T cells. Moreover, we identified an active role for HIF-1α in the modulation of CD4+ T cell functions under hypoxic conditions. Conclusion: Our data indicate that oxygen availability can function as a local modulator of CD4+ T cell responses and thus influences tumour immune surveillance in inflammation-associated colon cancer.

  5. The relationship between temporal variation of hypoxia, polarographic measurements and predictions of tumour response to radiation

    Toma-Dasu, Iuliana; Dasu, Alexandru; Karlsson, Mikael

    2004-10-01

    The polarographic oxygen sensor is one of the most used devices for in vivo measurements of oxygen and many other measurement techniques for measuring tumour hypoxia are correlated with electrode measurements. Little is known however about the relationship between electrode measurements and the real tissue oxygenation. This paper investigates the influence of the temporal change of the hypoxic pattern on the electrode measurements and the tumour response. Electrode measurements and tumour response were simulated using a computer program that allows both the calculation of the tissue oxygenation with respect to the two types of hypoxia that might arise in tumours and the virtual insertion of the electrode into the tissue. It was therefore possible to control the amount of each type of hypoxia in order to investigate their influence on the measurement results. Tissues with several vascular architectures ranging from well oxygenated to poorly oxygenated were taken into consideration as might be seen in practice. The influence of the electrode measurements on the treatment outcome was estimated by calculating the tumour control probability for the tumours characterized either by the real or by the measured tumour oxygenation. We have simulated electrode oxygen measurements in different types of tissues, covering a wide range of tumour oxygenations. The results of the simulations showed that the measured distribution depends on the details of the vascular network and not on the type of hypoxia. We have also simulated the effects of the temporal change of the acute hypoxic pattern due to the opening and the closure of different blood vessels during a full fractionated treatment. The results of this simulation suggested that the temporal variation of the hypoxic pattern does not lead to significantly different results for the electrode measurements or the predicted tumour control probabilities. In conclusion, it was found that the averaging effect of the electrode leads

  6. Enhanced response to radiotherapy in tumours deficient in the function of hypoxia-inducible factor-1

    Williams, Kaye J.; Telfer, Brian A.; Xenaki, Dia; Sheridan, Mary R.; Desbaillets, Isabelle; Peters, Hans J.W.; Honess, Davina; Harris, Adrian L.; Dachs, Gabi U.; Kogel, Albert van der; Stratford, Ian J.

    2005-01-01

    Background and purpose: To test the hypothesis that deficiency in expression of the transcription factor, HIF-1, renders tumours more radioresponsive than HIF-1 proficient tumours. Patients and methods: Tumours comprising mouse hepatoma cells lacking HIF-1β (and thereby HIF-1 function) were grown in nude mice and radiation-induced growth delay compared with that seen for wild-type tumours and tumours derived from HIF-1β negative cells where HIF-1 function had been restored. Results: The xenografts that lack HIF-1 activity take longer to establish their growth and are more radioresponsive than both parental xenografts and those with restored HIF-1 function. Pre-treatment of the HIF-1 deficient xenografts with the hypoxic radiosensitizer misonidazole, had little effect on radioresponse. In contrast this treatment radiosensitized the parental xenografts. In spite of this, no difference in oxygenation status was found between the tumour types as measured by Eppendorf O 2 -electrodes and by binding of the hypoxic cell marker NITP. Admixing wild type and HIF-1 deficient cells in the same tumour at ratios of 1 in 10 and 1 in 100 restores the growth of the mixed tumours to that of a 100% HIF-1 proficient cell population. However, when comparing the effects of radiation on the mixed tumours, radioresponsiveness is maintained in those tumours containing the high proportion of HIF-1 deficient cells. Conclusions: The differences in radioresponse do not correlate with tumour oxygenation, suggesting that the hypoxic cells within the HIF-1 deficient tumours do not contribute to the outcome of radiotherapy. Thus, hypoxia impacts on tumour radioresponsiveness not simply because of the physio-chemical mechanism of oxygen with radiation-induced radicals causing damage 'fixation', but also because hypoxia/HIF-1 promotes expression of genes that allow tumour cells to survive under these adverse conditions. Further, the results from the cell mixing experiments uncouple the growth

  7. Multiparametric imaging of patient and tumour heterogeneity in non-small-cell lung cancer: quantification of tumour hypoxia, metabolism and perfusion

    Elmpt, Wouter van; Zegers, Catharina M.L.; Reymen, Bart; Even, Aniek J.G.; Oellers, Michel; Troost, Esther G.C.; Lambin, Philippe [Maastricht University Medical Centre, Department of Radiation Oncology (MAASTRO), GROW - School for Oncology and Developmental Biology, Maastricht (Netherlands); Dingemans, Anne-Marie C. [Maastricht University Medical Centre, Department of Pulmonology, GROW - School for Oncology and Developmental Biology, Maastricht (Netherlands); Wildberger, Joachim E.; Das, Marco [Maastricht University Medical Centre, Department of Radiology, GROW - School for Oncology and Developmental Biology, Maastricht (Netherlands); Mottaghy, Felix M. [Maastricht University Medical Centre, Department of Nuclear Medicine, GROW - School for Oncology and Developmental Biology, Maastricht (Netherlands); University Hospital RWTH Aachen University, Department of Nuclear Medicine, Aachen (Germany)

    2016-02-15

    Multiple imaging techniques are nowadays available for clinical in-vivo visualization of tumour biology. FDG PET/CT identifies increased tumour metabolism, hypoxia PET visualizes tumour oxygenation and dynamic contrast-enhanced (DCE) CT characterizes vasculature and morphology. We explored the relationships among these biological features in patients with non-small-cell lung cancer (NSCLC) at both the patient level and the tumour subvolume level. A group of 14 NSCLC patients from two ongoing clinical trials (NCT01024829 and NCT01210378) were scanned using FDG PET/CT, HX4 PET/CT and DCE CT prior to chemoradiotherapy. Standardized uptake values (SUV) in the primary tumour were calculated for the FDG and hypoxia HX4 PET/CT scans. For hypoxia imaging, the hypoxic volume, fraction and tumour-to-blood ratio (TBR) were also defined. Blood flow and blood volume were obtained from DCE CT imaging. A tumour subvolume analysis was used to quantify the spatial overlap between subvolumes. At the patient level, negative correlations were observed between blood flow and the hypoxia parameters (TBR >1.2): hypoxic volume (-0.65, p = 0.014), hypoxic fraction (-0.60, p = 0.025) and TBR (-0.56, p = 0.042). At the tumour subvolume level, hypoxic and metabolically active subvolumes showed an overlap of 53 ± 36 %. Overlap between hypoxic sub-volumes and those with high blood flow and blood volume was smaller: 15 ± 17 % and 28 ± 28 %, respectively. Half of the patients showed a spatial mismatch (overlap <5 %) between increased blood flow and hypoxia. The biological imaging features defined in NSCLC tumours showed large interpatient and intratumour variability. There was overlap between hypoxic and metabolically active subvolumes in the majority of tumours, there was spatial mismatch between regions with high blood flow and those with increased hypoxia. (orig.)

  8. Hypoxia-activated chemotherapeutic TH-302 enhances the effects of VEGF-A inhibition and radiation on sarcomas.

    Yoon, C; Lee, H-J; Park, D J; Lee, Y-J; Tap, W D; Eisinger-Mathason, T S K; Hart, C P; Choy, E; Simon, M C; Yoon, S S

    2015-06-30

    Human sarcomas with a poor response to vascular endothelial growth factor-A (VEGF-A) inhibition and radiation therapy (RT) have upregulation of hypoxia-inducible factor 1α (HIF-1α) and HIF-1α target genes. This study examines the addition of the hypoxia-activated chemotherapy TH-302 to VEGF-A inhibition and RT (a.k.a. trimodality therapy). Trimodality therapy was examined in two xenograft models and in vitro in tumour endothelial cells and sarcoma cell lines. In both mouse models, VEGF-A inhibition and radiation showed greater efficacy than either therapy alone in slowing sarcoma growth. When TH-302 was added, this trimodality therapy completely blocked tumour growth with tumours remaining dormant for over 3 months after cessation of therapy. Trimodality therapy caused 2.6- to 6.2-fold more endothelial cell-specific apoptosis than bimodality therapies, and microvessel density and HIF-1α activity were reduced to 11-13% and 13-20% of control, respectively. When trimodality therapy was examined in vitro, increases in DNA damage and apoptosis were much more pronounced in tumour endothelial cells compared with that in sarcoma cells, especially under hypoxia. The combination of TH-302, VEGF-A inhibition, and RT is highly effective in preclinical models of sarcoma and is associated with increased DNA damage and apoptosis in endothelial cells and decreased HIF-1α activity.

  9. Physiological noise in murine solid tumours using T2*-weighted gradient-echo imaging: a marker of tumour acute hypoxia?

    Baudelet, Christine; Ansiaux, Reginald; Jordan, Benedicte F; Havaux, Xavier; Macq, Benoit; Gallez, Bernard

    2004-01-01

    T2*-weighted gradient-echo magnetic resonance imaging (T2*-weighted GRE MRI) was used to investigate spontaneous fluctuations in tumour vasculature non-invasively. FSa fibrosarcomas, implanted intramuscularly (i.m.) in the legs of mice, were imaged at 4.7 T, over a 30 min or 1 h sampling period. On a voxel-by-voxel basis, time courses of signal intensity were analysed using a power spectrum density (PSD) analysis to isolate voxels for which signal changes did not originate from Gaussian white noise or linear drift. Under baseline conditions, the tumours exhibited spontaneous signal fluctuations showing spatial and temporal heterogeneity over the tumour. Statistically significant fluctuations occurred at frequencies ranging from 1 cycle/3 min to 1 cycle/h. The fluctuations were independent of the scanner instabilities. Two categories of signal fluctuations were reported: (i) true fluctuations (TFV), i.e., sequential signal increase and decrease, and (ii) profound drop in signal intensity with no apparent signal recovery (SDV). No temporal correlation between tumour and contralateral muscle fluctuations was observed. Furthermore, treatments aimed at decreasing perfusion-limited hypoxia, such as carbogen combined with nicotinamide and flunarizine, decreased the incidence of tumour T2*-weighted GRE fluctuations. We also tracked dynamic changes in T2* using multiple GRE imaging. Fluctuations of T2* were observed; however, fluctuation maps using PSD analysis could not be generated reliably. An echo-time dependency of the signal fluctuations was observed, which is typical to physiological noise. Finally, at the end of T2*-weighted GRE MRI acquisition, a dynamic contrast-enhanced MRI was performed to characterize the microenvironment in which tumour signal fluctuations occurred in terms of vessel functionality, vascularity and microvascular permeability. Our data showed that TFV were predominantly located in regions with functional vessels, whereas SDV occurred in regions

  10. Hypoxia inhibits colonic ion transport via activation of AMP kinase.

    Collins, Danielle

    2012-02-01

    BACKGROUND AND AIMS: Mucosal hypoxia is a common endpoint for many pathological processes including ischemic colitis, colonic obstruction and anastomotic failure. Previous studies suggest that hypoxia modulates colonic mucosal function through inhibition of chloride secretion. However, the molecular mechanisms underlying this observation are poorly understood. AMP-activated protein kinase (AMPK) is a metabolic energy regulator found in a wide variety of cells and has been linked to cystic fibrosis transmembrane conductance regulator (CFTR) mediated chloride secretion in several different tissues. We hypothesized that AMPK mediates many of the acute effects of hypoxia on human and rat colonic electrolyte transport. METHODS: The fluorescent chloride indicator dye N-(ethoxycarbonylmethyl)-6-methoxyquinolinium bromide was used to measure changes in intracellular chloride concentrations in isolated single rat colonic crypts. Ussing chamber experiments in human colonic mucosa were conducted to evaluate net epithelial ion transport. RESULTS: This study demonstrates that acute hypoxia inhibits electrogenic chloride secretion via AMPK mediated inhibition of CFTR. Pre-treatment of tissues with the AMPK inhibitor 6-[4-(2-piperidin-1-yl-ethoxy)-phenyl)]-3-pyridin-4-yl-pyyrazolo [1,5-a] pyrimidine (compound C) in part reversed the effects of acute hypoxia on chloride secretion. CONCLUSION: We therefore suggest that AMPK is a key component of the adaptive cellular response to mucosal hypoxia in the colon. Furthermore, AMPK may represent a potential therapeutic target in diseased states or in prevention of ischemic intestinal injury.

  11. Hypoxia Inducible Factor-1α (HIF-1 α and its Role in Tumour Progression to Malignancy

    Gaurav Mrinal Sharma

    2008-07-01

    Full Text Available Hypoxia is a condition in which an area of the body or a tissue is deprived of sufficient supply of oxygen. The lack of nutrients in a hypoxic tissue generally causes apoptosis but some cells are able to adapt to this hypoxic environment and resist apoptosis. This adaptation occurs as a result of gene activation. Hypoxia is a characteristic feature of many cancers and is the stimulus for overexpression of HIF-1α - a basic loop-helix PAS protein family subunit of HIF, which allows the cell to adapt and survive in hostile environment. The presence of hypoxia and HIF-1α is correlated with an increased risk of metastasis and techniques that can inhibit hypoxia inducible factor may be instrumental in finding a cure for cancer.

  12. Inhibition of calcium uptake during hypoxia in developing zebrafish is mediated by hypoxia-inducible factor.

    Kwong, Raymond W M; Kumai, Yusuke; Tzaneva, Velislava; Azzi, Estelle; Hochhold, Nina; Robertson, Cayleih; Pelster, Bernd; Perry, Steve F

    2016-12-15

    The present study investigated the potential role of hypoxia-inducible factor (HIF) in calcium homeostasis in developing zebrafish (Danio rerio). It was demonstrated that zebrafish raised in hypoxic water (30 mmHg; control, 155 mmHg P O 2 ) until 4 days post-fertilization exhibited a substantial reduction in whole-body Ca 2+ levels and Ca 2+ uptake. Ca 2+ uptake in hypoxia-treated fish did not return to pre-hypoxia (control) levels within 2 h of transfer back to normoxic water. Results from real-time PCR showed that hypoxia decreased the whole-body mRNA expression levels of the epithelial Ca 2+ channel (ecac), but not plasma membrane Ca 2+ -ATPase (pmca2) or Na + /Ca 2+ -exchanger (ncx1b). Whole-mount in situ hybridization revealed that the number of ecac-expressing ionocytes was reduced in fish raised in hypoxic water. These findings suggested that hypoxic treatment suppressed the expression of ecac, thereby reducing Ca 2+ influx. To further evaluate the potential mechanisms for the effects of hypoxia on Ca 2+ regulation, a functional gene knockdown approach was employed to prevent the expression of HIF-1αb during hypoxic treatment. Consistent with a role for HIF-1αb in regulating Ca 2+ balance during hypoxia, the results demonstrated that the reduction of Ca 2+ uptake associated with hypoxic exposure was not observed in fish experiencing HIF-1αb knockdown. Additionally, the effects of hypoxia on reducing the number of ecac-expressing ionocytes was less pronounced in HIF-1αb-deficient fish. Overall, the current study revealed that hypoxic exposure inhibited Ca 2+ uptake in developing zebrafish, probably owing to HIF-1αb-mediated suppression of ecac expression. © 2016. Published by The Company of Biologists Ltd.

  13. Hypoxia inhibits hypertrophic differentiation and endochondral ossification in explanted tibiae.

    Jeroen C H Leijten

    Full Text Available Hypertrophic differentiation of growth plate chondrocytes induces angiogenesis which alleviates hypoxia normally present in cartilage. In the current study, we aim to determine whether alleviation of hypoxia is merely a downstream effect of hypertrophic differentiation as previously described or whether alleviation of hypoxia and consequent changes in oxygen tension mediated signaling events also plays an active role in regulating the hypertrophic differentiation process itself.Fetal mouse tibiae (E17.5 explants were cultured up to 21 days under normoxic or hypoxic conditions (21% and 2.5% oxygen respectively. Tibiae were analyzed on growth kinetics, histology, gene expression and protein secretion.The oxygen level had a strong influence on the development of explanted fetal tibiae. Compared to hypoxia, normoxia increased the length of the tibiae, length of the hypertrophic zone, calcification of the cartilage and mRNA levels of hypertrophic differentiation-related genes e.g. MMP9, MMP13, RUNX2, COL10A1 and ALPL. Compared to normoxia, hypoxia increased the size of the cartilaginous epiphysis, length of the resting zone, calcification of the bone and mRNA levels of hyaline cartilage-related genes e.g. ACAN, COL2A1 and SOX9. Additionally, hypoxia enhanced the mRNA and protein expression of the secreted articular cartilage markers GREM1, FRZB and DKK1, which are able to inhibit hypertrophic differentiation.Collectively our data suggests that oxygen levels play an active role in the regulation of hypertrophic differentiation of hyaline chondrocytes. Normoxia stimulates hypertrophic differentiation evidenced by the expression of hypertrophic differentiation related genes. In contrast, hypoxia suppresses hypertrophic differentiation of chondrocytes, which might be at least partially explained by the induction of GREM1, FRZB and DKK1 expression.

  14. Oxygen tension in human tumours measured with polarographic needle electrodes and its relationship to vascular density, necrosis and hypoxia

    Lyng, Heidi; Sundfoer, Kolbein; Rofstad, Einar K.

    1997-01-01

    Background and purpose: The use of polarographic needle electrodes for measurement of oxygen tension (pO 2 ) in tumours requires documentation of the validity of the method. In the present work the pO 2 values measured polarographically with the Eppendorf pO 2 histograph in human tumours were compared with the histological appearance of the tumour tissue, i.e. vascular density, fraction of necrosis and fraction of hypoxic tissue, to investigate whether the measurements reflected the expected pO 2 . Materials and methods: The pO 2 was measured in cervix tumours in patients and in human melanoma xenografted tumours in athymic mice. Vascular density was determined in the cervix tumours by histological analysis of biopsies from the pO 2 measurement tracks. Fraction of necrosis and fraction of hypoxic tissue, i.e. tissue binding the hypoxia marker pimonidazole, were determined in the melanomas by analysis of histological sections from the tumour planes in which the pO 2 measurements were performed. Results: The pO 2 distributions showed large intratumour heterogeneity. In cervix tumours, tumour regions with vascular density (vascular length per unit tissue volume) in the range of 47-77 mm/mm 3 showed higher pO 2 than tumour regions with vascular density in the range of 20-47 mm/mm 3 , which in turn showed higher pO 2 than tumour regions with vascular density in the range of 0-20 mm/mm 3 . In melanomas, tumour regions in which necrosis and hypoxia constituted more than 50% of the tissue showed lower pO 2 than other tumour regions. Conclusions: The pO 2 measured in the tumours was consistent with the histological appearance of the tissue in which the measurements were performed, suggesting that reliable pO 2 distributions of tumours can be obtained with polarographic needle electrodes

  15. Modelling the interplay between hypoxia and proliferation in radiotherapy tumour response

    Jeong, J; Deasy, J O; Shoghi, K I

    2013-01-01

    A tumour control probability computational model for fractionated radiotherapy was developed, with the goal of incorporating the fundamental interplay between hypoxia and proliferation, including reoxygenation over a course of radiotherapy. The fundamental idea is that the local delivery of oxygen and glucose limits the amount of proliferation and metabolically-supported cell survival a tumour sub-volume can support. The model has three compartments: a proliferating compartment of cells receiving oxygen and glucose; an intermediate, metabolically-active compartment receiving glucose; and a highly hypoxic compartment of starving cells. Following the post-mitotic cell death of proliferating cells, intermediate cells move into the proliferative compartment and hypoxic cells move into the intermediate compartment. A key advantage of the proposed model is that the initial compartmental cell distribution is uniquely determined from the assumed local growth fraction (GF) and volume doubling time (T D ) values. Varying initial cell state distributions, based on the local (voxel) GF and T D , were simulated. Tumour response was simulated for head and neck squamous cell carcinoma using relevant parameter values based on published sources. The tumour dose required to achieve a 50% local control rate (TCD 50 ) was found for various GFs and T D ’s, and the effect of fraction size on TCD 50 was also evaluated. Due to the advantage of reoxygenation over a course of radiotherapy, conventional fraction sizes (2–2.4 Gy fx −1 ) were predicted to result in smaller TCD 50 's than larger fraction sizes (4–5 Gy fx –1 ) for a 10 cc tumour with GFs of around 0.15. The time to eliminate hypoxic cells (the reoxygenation time) was estimated for a given GF and decreased as GF increased. The extra dose required to overcome accelerated stem cell accumulation in longer treatment schedules was estimated to be 0.68 Gy/day (in EQD2 6.6 ), similar to published values derived from clinical

  16. Proline-hydroxylated hypoxia-inducible factor 1α (HIF-1α upregulation in human tumours.

    Cameron E Snell

    Full Text Available The stabilisation of HIF-α is central to the transcriptional response of animals to hypoxia, regulating the expression of hundreds of genes including those involved in angiogenesis, metabolism and metastasis. HIF-α is degraded under normoxic conditions by proline hydroxylation, which allows for recognition and ubiquitination by the von-Hippel-Lindau (VHL E3 ligase complex. The aim of our study was to investigate the posttranslational modification of HIF-1α in tumours, to assess whether there are additional mechanisms besides reduced hydroxylation leading to stability. To this end we optimised antibodies against the proline-hydroxylated forms of HIF-1α for use in formalin fixed paraffin embedded (FFPE immunohistochemistry to assess effects in tumour cells in vivo. We found that HIF-1α proline-hydroxylated at both VHL binding sites (Pro402 and Pro564, was present in hypoxic regions of a wide range of tumours, tumour xenografts and in moderately hypoxic cells in vitro. Staining for hydroxylated HIF-1α can identify a subset of breast cancer patients with poorer prognosis and may be a better marker than total HIF-1α levels. The expression of unhydroxylated HIF-1α positively correlates with VHL in breast cancer suggesting that VHL may be rate-limiting for HIF degradation. Our conclusions are that the degradation of proline-hydroxylated HIF-1α may be rate-limited in tumours and therefore provides new insights into mechanisms of HIF upregulation. Persistence of proline-hydroxylated HIF-1α in perinecrotic areas suggests there is adequate oxygen to support prolyl hydroxylase domain (PHD activity and proline-hydroxylated HIF-1α may be the predominant form associated with the poorer prognosis that higher levels of HIF-1α confer.

  17. Targeted BCL2 inhibition effectively inhibits neuroblastoma tumour growth

    Lamers, Fieke; Schild, Linda; den Hartog, Ilona J. M.; Ebus, Marli E.; Westerhout, Ellen M.; Ora, Ingrid; Koster, Jan; Versteeg, Rogier; Caron, Huib N.; Molenaar, Jan J.

    2012-01-01

    Genomic aberrations of key regulators of the apoptotic pathway have hardly been identified in neuroblastoma. We detected high BCL2 mRNA and protein levels in the majority of neuroblastoma tumours by Affymetrix expression profiling and Tissue Micro Array analysis. This BCL2 mRNA expression is

  18. Quercetin suppresses hypoxia-induced accumulation of hypoxia-inducible factor-1alpha (HIF-1alpha) through inhibiting protein synthesis.

    Lee, Dae-Hee; Lee, Yong J

    2008-10-01

    Quercetin, a ubiquitous bioactive plant flavonoid, has been shown to inhibit the proliferation of cancer cells and induce the accumulation of hypoxia-inducible factor-1alpha (HIF-1alpha) in normoxia. In this study, under hypoxic conditions (1% O(2)), we examined the effect of quercetin on the intracellular level of HIF-1alpha and extracellular level of vascular endothelial growth factor (VEGF) in a variety of human cancer cell lines. Surprisingly, we observed that quercetin suppressed the HIF-1alpha accumulation during hypoxia in human prostate cancer LNCaP, colon cancer CX-1, and breast cancer SkBr3 cells. Quercetin treatment also significantly reduced hypoxia-induced secretion of VEGF. Suppression of HIF-1alpha accumulation during treatment with quercetin in hypoxia was not prevented by treatment with 26S proteasome inhibitor MG132 or PI3K inhibitor LY294002. Interestingly, hypoxia (1% O(2)) in the presence of 100 microM quercetin inhibited protein synthesis by 94% during incubation for 8 h. Significant quercetin concentration-dependent inhibition of protein synthesis and suppression of HIF-1alpha accumulation were observed under hypoxic conditions. Treatment with 100 microM cycloheximide, a protein synthesis inhibitor, replicated the effect of quercetin by inhibiting HIF-1alpha accumulation during hypoxia. These results suggest that suppression of HIF-1alpha accumulation during treatment with quercetin under hypoxic conditions is due to inhibition of protein synthesis. (c) 2008 Wiley-Liss, Inc.

  19. Treatment fractionation for stereotactic radiotherapy of lung tumours: a modelling study of the influence of chronic and acute hypoxia on tumour control probability

    Lindblom, Emely; Antonovic, Laura; Dasu, Alexandru; Lax, Ingmar; Wersäll, Peter; Toma-Dasu, Iuliana

    2014-01-01

    Stereotactic body radiotherapy (SBRT) for non-small-cell lung cancer (NSCLC) has led to promising local control and overall survival for fractionation schemes with increasingly high fractional doses. A point has however been reached where the number of fractions used might be too low to allow efficient local inter-fraction reoxygenation of the hypoxic cells residing in the tumour. It was therefore the purpose of this study to investigate the impact of hypoxia and extreme hypofractionation on the tumour control probability (TCP) from SBRT. A three-dimensional model of tumour oxygenation able to simulate oxygenation changes on the microscale was used. The TCP was determined for clinically relevant SBRT fractionation schedules of 1, 3 and 5 fractions assuming either static tumour oxygenation or that the oxygenation changes locally between fractions due to fast reoxygenation of acute hypoxia without an overall reduction in chronic hypoxia. For the schedules applying three or five fractions the doses required to achieve satisfying levels of TCP were considerably lower when local oxygenation changes were assumed compared to the case of static oxygenation; a decrease in D 50 of 17.7 Gy was observed for a five-fractions schedule applied to a 20% hypoxic tumour when fast reoxygenation was modelled. Assuming local oxygenation changes, the total doses required for a tumor control probability of 50% were of similar size for one, three and five fractions. Although attractive from a practical point of view, extreme hypofractionation using just one single fraction may result in impaired local control of hypoxic tumours, as it eliminates the possibility for any kind of reoxygenation

  20. PTP1B controls non-mitochondrial oxygen consumption by regulating RNF213 to promote tumour survival during hypoxia.

    Banh, Robert S; Iorio, Caterina; Marcotte, Richard; Xu, Yang; Cojocari, Dan; Rahman, Anas Abdel; Pawling, Judy; Zhang, Wei; Sinha, Ankit; Rose, Christopher M; Isasa, Marta; Zhang, Shuang; Wu, Ronald; Virtanen, Carl; Hitomi, Toshiaki; Habu, Toshiyuki; Sidhu, Sachdev S; Koizumi, Akio; Wilkins, Sarah E; Kislinger, Thomas; Gygi, Steven P; Schofield, Christopher J; Dennis, James W; Wouters, Bradly G; Neel, Benjamin G

    2016-07-01

    Tumours exist in a hypoxic microenvironment and must limit excessive oxygen consumption. Hypoxia-inducible factor (HIF) controls mitochondrial oxygen consumption, but how/if tumours regulate non-mitochondrial oxygen consumption (NMOC) is unknown. Protein-tyrosine phosphatase-1B (PTP1B) is required for Her2/Neu-driven breast cancer (BC) in mice, although the underlying mechanism and human relevance remain unclear. We found that PTP1B-deficient HER2(+) xenografts have increased hypoxia, necrosis and impaired growth. In vitro, PTP1B deficiency sensitizes HER2(+) BC lines to hypoxia by increasing NMOC by α-KG-dependent dioxygenases (α-KGDDs). The moyamoya disease gene product RNF213, an E3 ligase, is negatively regulated by PTP1B in HER2(+) BC cells. RNF213 knockdown reverses the effects of PTP1B deficiency on α-KGDDs, NMOC and hypoxia-induced death of HER2(+) BC cells, and partially restores tumorigenicity. We conclude that PTP1B acts via RNF213 to suppress α-KGDD activity and NMOC. This PTP1B/RNF213/α-KGDD pathway is critical for survival of HER2(+) BC, and possibly other malignancies, in the hypoxic tumour microenvironment.

  1. Hypoxia increases exercise heart rate despite combined inhibition of β-adrenergic and muscarinic receptors

    Siebenmann, Christoph; Rasmussen, Peter; Sørensen, Henrik

    2015-01-01

    Hypoxia increases the heart rate (HR) response to exercise but the mechanism(s) remain unclear. We tested the hypothesis that the tachycardic effect of hypoxia persists during separate but not combined inhibition of β-adrenergic and muscarinic receptors. Nine subjects performed incremental exercise...... combined β-adrenergic and muscarinic receptor inhibition....

  2. Vitamin E supplementation inhibits muscle damage and inflammation after moderate exercise in hypoxia.

    Santos, S A; Silva, E T; Caris, A V; Lira, F S; Tufik, S; Dos Santos, R V T

    2016-08-01

    Exercise under hypoxic conditions represents an additional stress in relation to exercise in normoxia. Hypoxia induces oxidative stress and inflammation as mediated through tumour necrosis factor (TNF)-α release that might be exacerbated through exercise. In addition, vitamin E supplementation might attenuate oxidative stress and inflammation resulting from hypoxia during exercise. The present study aimed to evaluate the effects of vitamin E supplementation (250 mg) on inflammatory parameters and cellular damage after exercise under hypoxia simulating an altitude of 4200 m. Nine volunteers performed three sessions of 60 min of exercise (70% maximal oxygen uptake) interspersed for 1 week under normoxia, hypoxia and hypoxia after vitamin E supplementation 1 h before exercise. Blood was collected before, immediately after and at 1 h after exercise to measure inflammatory parameters and cell damage. Percentage oxygen saturation of haemoglobin decreased after exercise and recovered 1 h later in the hypoxia + vitamin condition (P exercise (P exercise in hypoxia increased interleukin (IL)-6, TNF-α, IL-1ra and IL-10 immediately after exercise (P exercise in hypoxia without supplementation (P exercise reduces cell damage markers after exercise in hypoxia and changes the concentration of cytokines, suggesting a possible protective effect against inflammation induced by hypoxia during exercise. © 2016 The British Dietetic Association Ltd.

  3. Reducing intratumour acute hypoxia through bevacizumab treatment, referring to the response of quiescent tumour cells and metastatic potential

    Masunaga, S; Liu, Y; Tanaka, H; Sakurai, Y; Suzuki, M; Kondo, N; Maruhashi, A; Ono, K

    2011-01-01

    Objectives The aim was to evaluate the influence of bevacizumab on intratumour oxygenation status and lung metastasis following radiotherapy, with specific reference to the response of quiescent (Q) cell populations within irradiated tumours. Methods B16-BL6 melanoma tumour-bearing C57BL/6 mice were continuously given 5-bromo-2-deoxyuridine (BrdU) to label all proliferating (P) cells. They received γ-ray irradiation following treatment with the acute hypoxia-releasing agent nicotinamide or local mild temperature hyperthermia (MTH) with or without the administration of bevacizumab under aerobic conditions or totally hypoxic conditions, achieved by clamping the proximal end of the tumours. Immediately after the irradiation, cells from some tumours were isolated and incubated with a cytokinesis blocker. The responses of the Q and total (P + Q) cell populations were assessed based on the frequency of micronuclei using immunofluorescence staining for BrdU. In the other tumour-bearing mice, macroscopic lung metastases were enumerated 17 days after irradiation. Results 3 days after bevacizumab administration, acute hypoxia-rich total cell population in the tumour showed a remarkably enhanced radiosensitivity to γ-rays, and the hypoxic fraction (HF) was reduced, even after MTH treatment. However, the hypoxic fraction was not reduced after nicotinamide treatment. With or without γ-ray irradiation, bevacizumab administration showed some potential to reduce the number of lung metastases as well as nicotinamide treatment. Conclusion Bevacizumab has the potential to reduce perfusion-limited acute hypoxia and some potential to cause a decrease in the number of lung metastases as well as nicotinamide. PMID:21586505

  4. Rapid dual-tracer PTSM+ATSM PET imaging of tumour blood flow and hypoxia: a simulation study

    Rust, T C; Kadrmas, D J

    2006-01-01

    Blood flow and hypoxia are interrelated aspects of physiology that affect cancer treatment and response. Cu-PTSM and Cu-ATSM are related PET tracers for blood flow and hypoxia, and the ability to rapidly image both tracers in a single scan would bring several advantages over conventional single-tracer techniques. Using dynamic imaging with staggered injections, overlapping signals for multiple PET tracers may be recovered utilizing information from kinetics and radioactive decay. In this work, rapid dual-tracer PTSM+ATSM PET was simulated and tested as a function of injection delay, order and relative dose for several copper isotopes, and the results were compared relative to separate single-tracer data. Time-activity curves representing a broad range of tumour blood flow and hypoxia levels were simulated, and parallel dual-tracer compartment modelling was used to recover the signals for each tracer. The main results were tested further using a torso phantom simulation of PET tumour imaging. Using scans as short as 30 minutes, the dual-tracer method provided measures of blood flow and hypoxia similar to single-tracer imaging. The best performance was obtained by injecting PTSM first and using a somewhat higher dose for ATSM. Comparable results for different copper isotopes suggest that tracer kinetics with staggered injections play a more important role than radioactive decay in the signal separation process. Rapid PTSM+ATSM PET has excellent potential for characterizing both tumour blood flow and hypoxia in a single, fast scan, provided that technological hurdles related to algorithm development and routine use can be overcome

  5. HYPOXIA-ACTIVATED PRO-DRUG TH-302 EXHIBITS POTENT TUMOUR SUPPRESSIVE ACTIVITY AND COOPERATES WITH CHEMOTHERAPY AGAINST OSTEOSARCOMA

    Liapis, Vasilios; Labrinidis, Agatha; Zinonos, Irene; Hay, Shelley; Ponomarev, Vladimir; Panagopoulos, Vasilios; DeNichilo, Mark; Ingman, Wendy; Atkins, Gerald J.; Findlay, David M.; Zannettino, Andrew CW.; Evdokiou, Andreas

    2015-01-01

    Tumour hypoxia is a major cause of treatment failure for a variety of malignancies. However, tumour hypoxia also offers treatment opportunities, exemplified by the development compounds that target hypoxic regions within tumours. TH-302 is a pro-drug created by the conjugation of 2-nitroimidazole to bromo-isophosphoramide (Br-IPM). When TH-302 is delivered to regions of hypoxia, Br-IPM, the DNA cross linking toxin, is released. In this study we assessed the cytotoxic activity of TH-302 against osteosarcoma cells in vitro and evaluated its anticancer efficacy as a single agent, and in combination with doxorubicin, in an orthotopic mouse model of human osteosarcoma (OS). In vitro, TH-302 was potently cytotoxic to osteosarcoma cells selectively under hypoxic conditions, whereas primary normal human osteoblasts were protected. Animals transplanted with OS cells directly into their tibiae and left untreated developed mixed osteolytic/osteosclerotic bone lesions and subsequently developed lung metastases. TH-302 reduced tumor burden in bone and cooperated with doxorubicin to protect bone from osteosarcoma induced bone destruction, while it also reduced lung metastases. TH-302 may therefore be an attractive therapeutic agent with strong activity as a single agent and in combination with chemotherapy against OS. PMID:25444931

  6. Chlorpromazine inhibits tumour necrosis factor synthesis and cytotoxicity in vitro.

    Zinetti, M; Galli, G; Demitri, M T; Fantuzzi, G; Minto, M; Ghezzi, P; Alzani, R; Cozzi, E; Fratelli, M

    1995-11-01

    Chlorpromazine (CPZ) has been previously shown to protect against endotoxin [lipopolysaccharide (LPS)] lethality and inhibit the release of tumour necrosis factor in vivo. We investigated at the cellular level whether this was due to direct inhibition of tumour necrosis factor-alpha (TNF-alpha) synthesis, using LPS-stimulated THP-1 human monocytic leukemia cells. We also studied the effect of CPZ on human TNF-alpha action by assessing TNF-alpha cytotoxicity on mouse fibrosarcoma L929 cells. CPZ (1-100 microM) inhibited TNF-alpha production in THP-1 cells in a dose dependent manner by a maximum of 80%. This effect was comparable to that of two well-known inhibitory drugs, dexamethasone and cyclicAMP. Inhibition was also evident at the mRNA level. On the other hand CPZ (10-25 microM) also inhibited TNF-alpha activity: in fact it reduced the cytotoxicity of TNF-alpha on L929 cells (EC50 was increased four times) and could provide protection even as a post-treatment. CPZ inhibited TNF-induced apoptosis in L929 cells, as detected by analysis of nuclear morphology. However, since we showed that apoptosis was very limited, and was not the main mode of cell death in our conditions, this could not explain the overall protection. Since CPZ did not interfere with either the oligomerization state of TNF-alpha or its receptor binding, our data suggest that it reduced cytotoxicity by inhibiting some steps in the TNF-alpha signalling pathways.

  7. Rapid detection of hypoxia-inducible factor-1-active tumours: pretargeted imaging with a protein degrading in a mechanism similar to hypoxia-inducible factor-1{alpha}

    Ueda, Masashi [Kyoto University, Radioisotopes Research Laboratory, Kyoto University Hospital, Faculty of Medicine, Kyoto (Japan); Kyoto University, Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto (Japan); Kudo, Takashi; Konishi, Hiroaki; Miyano, Azusa; Ono, Masahiro; Saji, Hideo [Kyoto University, Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto (Japan); Kuge, Yuji [Kyoto University, Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto (Japan); Hokkaido University, Central Institute of Isotope Science, Sapporo (Japan); Mukai, Takahiro [Kyushu University, Department of Biomolecular Recognition Chemistry, Graduate School of Pharmaceutical Sciences, Fukuoka (Japan); Tanaka, Shotaro; Kizaka-Kondoh, Shinae; Hiraoka, Masahiro [Kyoto University, Department of Radiation Oncology and Image-applied Therapy, Graduate School of Medicine, Kyoto (Japan)

    2010-08-15

    Hypoxia-inducible factor-1 (HIF-1) plays an important role in malignant tumour progression. For the imaging of HIF-1-active tumours, we previously developed a protein, POS, which is effectively delivered to and selectively stabilized in HIF-1-active cells, and a radioiodinated biotin derivative, (3-{sup 123}I-iodobenzoyl)norbiotinamide ({sup 123}I-IBB), which can bind to the streptavidin moiety of POS. In this study, we aimed to investigate the feasibility of the pretargeting method using POS and {sup 123}I-IBB for rapid imaging of HIF-1-active tumours. Tumour-implanted mice were pretargeted with POS. After 24 h, {sup 125}I-IBB was administered and subsequently, the biodistribution of radioactivity was investigated at several time points. In vivo planar imaging, comparison between {sup 125}I-IBB accumulation and HIF-1 transcriptional activity, and autoradiography were performed at 6 h after the administration of {sup 125}I-IBB. The same sections that were used in autoradiographic analysis were subjected to HIF-1{alpha} immunohistochemistry. {sup 125}I-IBB accumulation was observed in tumours of mice pretargeted with POS (1.6%ID/g at 6 h). This result is comparable to the data derived from {sup 125}I-IBB-conjugated POS-treated mice (1.4%ID/g at 24 h). In vivo planar imaging provided clear tumour images. The tumoral accumulation of {sup 125}I-IBB significantly correlated with HIF-1-dependent luciferase bioluminescence (R=0.84, p<0.01). The intratumoral distribution of {sup 125}I-IBB was heterogeneous and was significantly correlated with HIF-1{alpha}-positive regions (R=0.58, p<0.0001). POS pretargeting with {sup 123}I-IBB is a useful technique in the rapid imaging and detection of HIF-1-active regions in tumours. (orig.)

  8. Androgen deprivation results in time-dependent hypoxia in LNCaP prostate tumours: informed scheduling of the bioreductive drug AQ4N improves treatment response.

    Ming, Louise; Byrne, Niall M; Camac, Sarah Nicole; Mitchell, Christopher A; Ward, Claire; Waugh, David J; McKeown, Stephanie R; Worthington, Jenny

    2013-03-15

    Androgen withdrawal induces hypoxia in androgen-sensitive tissue; this is important as in the tumour microenvironment, hypoxia is known to drive malignant progression. Our study examined the time-dependent effect of androgen deprivation therapy (ADT) on tumour oxygenation and investigated the role of ADT-induced hypoxia on malignant progression in prostate tumours. LNCaP xenografted tumours were treated with anti-androgens and tumour oxygenation measured. Dorsal skin fold (DSF) chambers were used to image tumour vasculature in vivo. Quantitative PCR (QPCR) identified differential gene expression following treatment with bicalutamide. Bicalutamide-treated and vehicle-only-treated tumours were re-established in vitro, and invasion and sensitivity to docetaxel were measured. Tumour growth delay was calculated following treatment with bicalutamide combined with the bioreductive drug AQ4N. Tumour oxygenation measurements showed a precipitate decrease following initiation of ADT. A clinically relevant dose of bicalutamide (2 mg/kg/day) decreased tumour oxygenation by 45% within 24 hr, reaching a nadir of 0.09% oxygen (0.67 ± 0.06 mmHg) by Day 7; this persisted until Day 14 when it increased up to Day 28. Using DSF chambers, LNCaP tumours treated with bicalutamide showed loss of small vessels at Days 7 and 14 with revascularisation occurring by Day 21. QPCR showed changes in gene expression consistent with the vascular changes and malignant progression. Cells from bicalutamide-treated tumours were more malignant than vehicle-treated controls. Combining bicalutamide with AQ4N (50 mg/kg, single dose) caused greater tumour growth delay than bicalutamide alone. Our study shows that bicalutamide-induced hypoxia selects for cells that show malignant progression; targeting hypoxic cells may provide greater clinical benefit. Copyright © 2012 UICC.

  9. Simultaneous PLK1 inhibition improves local tumour control after fractionated irradiation

    Krause, Mechthild; Kummer, Berit; Deparade, Andre; Eicheler, Wolfgang; Pfitzmann, Dorothee; Yaromina, Ala; Kunz-Schughart, Leoni A.

    2013-01-01

    Purpose: Polo-like kinase 1 (PLK1) plays an important role in mitotic progression, is frequently overexpressed and associated with a poor prognosis of cancer patients, thus providing a promising target in anticancer treatment. Aim of the current project was to evaluate the effect of the novel PLK1 inhibitor BI 6727 in combination with irradiation. Material and methods: In vitro proliferation and radiation cell survival assays as well as in vivo local tumour control assays after single treatment and combined radiation and drug application were carried out using the squamous cell carcinoma models A431 and FaDu. In addition, cell cycle phases were monitored in vitro and in vivo. Results: BI 6727 showed a dose-dependent antiproliferative effect and an increase in the mitotic fraction. BI 6727 alone reduced clonogenic cell survival, while radiosensitivity in vitro (SF2) and in vivo (single-dose TCD 50 under clamped hypoxia) was not affected. In contrast, local tumour control was significantly improved after application of BI 6727 simultaneously to fractionated irradiation (A431: TCD 50 = 60.5 Gy [95% C.I. 57; 63] after IR alone and <30 Gy after combined treatment; FaDu: 49.5 Gy [43; 56 Gy] versus 32.9 Gy [26; 40]). Conclusions: Despite the lack of direct cellular radiosensitisation, PLK1 inhibition with BI 6727 during fractionated irradiation significantly improves local tumour control when compared to irradiation alone. This result is likely explained by a considerable effect on cell cycle and an independent cytotoxic potential of BI 6727

  10. Fast growth associated with aberrant vasculature and hypoxia in fibroblast growth factor 8b (FGF8b) over-expressing PC-3 prostate tumour xenografts

    Tuomela, Johanna; Solin, Olof; Minn, Heikki; Härkönen, Pirkko L; Grönroos, Tove J; Valta, Maija P; Sandholm, Jouko; Schrey, Aleksi; Seppänen, Jani; Marjamäki, Päivi; Forsback, Sarita; Kinnunen, Ilpo

    2010-01-01

    Prostate tumours are commonly poorly oxygenated which is associated with tumour progression and development of resistance to chemotherapeutic drugs and radiotherapy. Fibroblast growth factor 8b (FGF8b) is a mitogenic and angiogenic factor, which is expressed at an increased level in human prostate tumours and is associated with a poor prognosis. We studied the effect of FGF8b on tumour oxygenation and growth parameters in xenografts in comparison with vascular endothelial growth factor (VEGF)-expressing xenografts, representing another fast growing and angiogenic tumour model. Subcutaneous tumours of PC-3 cells transfected with FGF8b, VEGF or empty (mock) vectors were produced and studied for vascularity, cell proliferation, glucose metabolism and oxygenation. Tumours were evaluated by immunohistochemistry (IHC), flow cytometry, use of radiolabelled markers of energy metabolism ([ 18 F]FDG) and hypoxia ([ 18 F]EF5), and intratumoral polarographic measurements of pO 2 . Both FGF8b and VEGF tumours grew rapidly in nude mice and showed highly vascularised morphology. Perfusion studies, pO 2 measurements, [ 18 F]EF5 and [ 18 F]FDG uptake as well as IHC staining for glucose transport protein (GLUT1) and hypoxia inducible factor (HIF) 1 showed that VEGF xenografts were well-perfused and oxygenised, as expected, whereas FGF8b tumours were as hypoxic as mock tumours. These results suggest that FGF8b-induced tumour capillaries are defective. Nevertheless, the growth rate of hypoxic FGF8b tumours was highly increased, as that of well-oxygenised VEGF tumours, when compared with hypoxic mock tumour controls. FGF8b is able to induce fast growth in strongly hypoxic tumour microenvironment whereas VEGF-stimulated growth advantage is associated with improved perfusion and oxygenation of prostate tumour xenografts

  11. Beyond anaemia management: evolving role of erythropoietin therapy in neurological disorders, multiple myeloma and tumour hypoxia models.

    Boogaerts, Marc; Mittelman, Moshe; Vaupel, Peter

    2005-01-01

    Recombinant human erythropoietin (epoetin) has become the standard of care in the treatment of anaemia resulting from cancer and its treatment, and chronic kidney disease. The discovery that erythropoietin and its receptor are located in regions outside the erythropoietic system has led to interest in the potential role of epoetin in other tissues, such as the central nervous system. Animal studies have shown that systemically applied epoetin can cross the blood-brain barrier, where it reduces tissue injury associated with stroke, blunt trauma and experimental autoimmune encephalomyelitis. Pilot studies in humans have shown that epoetin treatment given within 8 h of stroke reduces infarct size and results in a significantly better outcome when compared with placebo treatment. Studies also suggest that epoetin has the potential to improve cognitive impairment associated with adjuvant chemotherapy in patients with cancer. Anaemia is a major factor causing tumour hypoxia, a condition that can promote changes within neoplastic cells that further tumour survival and malignant progression and also reduces the effectiveness of several anticancer therapies including radiotherapy and oxygen-dependent cytotoxic agents. Use of epoetin to prevent or correct anaemia has the potential to reduce tumour hypoxia and improve treatment outcome. Several therapeutic studies in anaemic animals with experimental tumours have shown a beneficial effect of epoetin on delaying tumour growth. Furthermore, clinical observations in patients with multiple myeloma and animal studies have suggested that epoetin has an antimyeloma effect, mediated via the immune system through activation of CD8+ T cells. Therefore, the role of epoetin may go well beyond that of increasing haemoglobin levels in anaemic patients, although additional studies are required to confirm these promising results. Copyright 2005 S. Karger AG, Basel.

  12. cGMP-Phosphodiesterase Inhibition Prevents Hypoxia-Induced Cell Death Activation in Porcine Retinal Explants.

    Lorena Olivares-González

    Full Text Available Retinal hypoxia and oxidative stress are involved in several retinal degenerations including diabetic retinopathy, glaucoma, central retinal artery occlusion, or retinopathy of prematurity. The second messenger cyclic guanosine monophosphate (cGMP has been reported to be protective for neuronal cells under several pathological conditions including ischemia/hypoxia. The purpose of this study was to evaluate whether the accumulation of cGMP through the pharmacological inhibition of phosphodiesterase (PDE with Zaprinast prevented retinal degeneration induced by mild hypoxia in cultures of porcine retina. Exposure to mild hypoxia (5% O2 for 24h reduced cGMP content and induced retinal degeneration by caspase dependent and independent (PARP activation mechanisms. Hypoxia also produced a redox imbalance reducing antioxidant response (superoxide dismutase and catalase activities and increasing superoxide free radical release. Zaprinast reduced mild hypoxia-induced cell death through inhibition of caspase-3 or PARP activation depending on the cell layer. PDE inhibition also ameliorated the effects of mild hypoxia on antioxidant response and the release of superoxide radical in the photoreceptor layer. The use of a PKG inhibitor, KT5823, suggested that cGMP-PKG pathway is involved in cell survival and antioxidant response. The inhibition of PDE, therefore, could be useful for reducing retinal degeneration under hypoxic/ischemic conditions.

  13. Fatty Acid Biosynthesis Inhibition Increases Reduction Potential in Neuronal Cells under Hypoxia

    Stephen A Brose

    2016-11-01

    Full Text Available Recently, we have reported a novel neuronal specific pathway for adaptation to hypoxia through increased fatty acid (FA biosynthesis (FAS followed by esterification into lipids. However, the biological role of this pathway under hypoxia remains to be elucidated. In the presented study, we have tested our hypothesis that activation of FAS maintains reduction potential and reduces lactoacidosis in neuronal cells under hypoxia. To address this hypothesis, we measured the effect of FAS inhibition on NADH2+/NAD+ and NADPH2+/NADP+ ratios, and lactic acid levels in neuronal SH-SY5Y cells exposed to normoxic and hypoxic conditions. FAS inhibitors, TOFA (inhibits Acetyl-CoA carboxylase and cerulenin (inhibits FA synthase, increased NADH2+/NAD+ and NADPH2+/NADP+ ratios under hypoxia. Further, FAS inhibition increased lactic acid under both normoxic and hypoxic conditions, and caused cytotoxicity under hypoxia but not normoxia. These results indicate that FA may serve as hydrogen acceptors under hypoxia, thus supporting oxidation reactions including anaerobic glycolysis. These findings may help to identify a radically different approach to attenuate hypoxia related pathophysiology in the nervous system including stroke.

  14. Fatty Acid Biosynthesis Inhibition Increases Reduction Potential in Neuronal Cells under Hypoxia.

    Brose, Stephen A; Golovko, Svetlana A; Golovko, Mikhail Y

    2016-01-01

    Recently, we have reported a novel neuronal specific pathway for adaptation to hypoxia through increased fatty acid (FA) biosynthesis followed by esterification into lipids. However, the biological role of this pathway under hypoxia remains to be elucidated. In the presented study, we have tested our hypothesis that activation of FA synthesis maintains reduction potential and reduces lactoacidosis in neuronal cells under hypoxia. To address this hypothesis, we measured the effect of FA synthesis inhibition on [Formula: see text]/NAD + and [Formula: see text]/NADP + ratios, and lactic acid levels in neuronal SH-SY5Y cells exposed to normoxic and hypoxic conditions. FA synthesis inhibitors, TOFA (inhibits Acetyl-CoA carboxylase) and cerulenin (inhibits FA synthase), increased [Formula: see text]/NAD + and [Formula: see text]/NADP + ratios under hypoxia. Further, FA synthesis inhibition increased lactic acid under both normoxic and hypoxic conditions, and caused cytotoxicity under hypoxia but not normoxia. These results indicate that FA may serve as hydrogen acceptors under hypoxia, thus supporting oxidation reactions including anaerobic glycolysis. These findings may help to identify a radically different approach to attenuate hypoxia related pathophysiology in the nervous system including stroke.

  15. Repeatability of tumour hypoxia imaging using [{sup 18}F]EF5 PET/CT in head and neck cancer

    Silvoniemi, Antti [University of Turku, Turku PET Centre (Finland); Turku University Hospital, Department of Otorhinolaryngology - Head and Neck Surgery (Finland); Suilamo, Sami [Turku University Hospital, Department of Oncology and Radiotherapy (Finland); Turku University Hospital, Department of Medical Physics (Finland); Laitinen, Timo; Forsback, Sarita; Solin, Olof [University of Turku, Turku PET Centre (Finland); Loeyttyniemi, Eliisa [University of Turku, Department of Biostatistics, Turku (Finland); Vaittinen, Samuli [Turku University Hospital, Department of Pathology (Finland); Saunavaara, Virva [University of Turku, Turku PET Centre (Finland); Turku University Hospital, Department of Medical Physics (Finland); Groenroos, Tove J.; Minn, Heikki [University of Turku, Turku PET Centre (Finland); Turku University Hospital, Department of Oncology and Radiotherapy (Finland)

    2018-02-15

    Hypoxia contributes to radiotherapy resistance and more aggressive behaviour of several types of cancer. This study was designed to evaluate the repeatability of intratumour uptake of the hypoxia tracer [{sup 18}F]EF5 in paired PET/CT scans. Ten patients with newly diagnosed head and neck cancer (HNC) received three static PET/CT scans before chemoradiotherapy: two with [{sup 18}F]EF5 a median of 7 days apart and one with [{sup 18}F]FDG. Metabolically active primary tumour volumes were defined in [{sup 18}F]FDG images and transferred to co-registered [{sup 18}F]EF5 images for repeatability analysis. A tumour-to-muscle uptake ratio (TMR) of 1.5 at 3 h from injection of [{sup 18}F]EF5 was used as a threshold representing hypoxic tissue. In 10 paired [{sup 18}F]EF5 PET/CT image sets, SUVmean, SUVmax, and TMR showed a good correlation with the intraclass correlation coefficients of 0.81, 0.85, and 0.87, respectively. The relative coefficients of repeatability for these parameters were 15%, 17%, and 10%, respectively. Fractional hypoxic volumes of the tumours in the repeated scans had a high correlation using the Spearman rank correlation test (r = 0.94). In a voxel-by-voxel TMR analysis between the repeated scans, the mean of Pearson correlation coefficients of individual patients was 0.65. The mean (± SD) difference of TMR in the pooled data set was 0.03 ± 0.20. Pretreatment [{sup 18}F]EF5 PET/CT within one week shows high repeatability and is feasible for the guiding of hypoxia-targeted treatment interventions in HNC. (orig.)

  16. Analysis of the effects of exposure to acute hypoxia on oxidative lesions and tumour progression in a transgenic mouse breast cancer model

    Lunt Sarah

    2008-05-01

    Full Text Available Abstract Background Tumour hypoxia is known to be a poor prognostic indicator, predictive of increased risk of metastatic disease and reduced survival. Genomic instability has been proposed as one of the potential mechanisms for hypoxic tumour progression. Both of these features are commonly found in many cancer types, but their relationship and association with tumour progression has not been examined in the same model. Methods To address this issue, we determined the effects of 6 week in vivo acute hypoxic exposure on the levels of mutagenic lipid peroxidation product, malondialdehyde, and 8-oxo-7,8-dihydro-2'-deoxyguanosine DNA (8-oxo-dG lesions in the transgenic polyomavirus middle T (PyMT breast cancer mouse model. Results We observed significantly increased plasma lipid peroxidation and 8-oxo-dG lesion levels in the hypoxia-exposed mice. Consumption of malondialdehyde also induced a significant increase in the PyMT tumour DNA lesion levels, however, these increases did not translate into enhanced tumour progression. We further showed that the in vivo exposure to acute hypoxia induced accumulation of F4/80 positive tumour-associated macrophages (TAMs, demonstrating a relationship between hypoxia and macrophages in an experimental model. Conclusion These data suggest that although exposure to acute hypoxia causes an increase in 8-oxo-dG lesions and TAMs in the PyMT tumours, these increases do not translate into significant changes in tumour progression at the primary or metastatic levels in this strong viral oncogene-driven breast cancer model.

  17. Enhanced response to radiotherapy in tumours deficient in the function of hypoxia-inducible factor-1.

    Williams, K.J.; Telfer, B.A.; Xenaki, D.; Sheridan, M.R.; Desbaillets, I.; Peters, H.J.; Honess, D.; Harris, A.L.; Dachs, G.U.; Kogel, A.J. van der; Stratford, I.J.

    2005-01-01

    BACKGROUND AND PURPOSE: To test the hypothesis that deficiency in expression of the transcription factor, HIF-1, renders tumours more radioresponsive than HIF-1 proficient tumours. PATIENTS AND METHODS: Tumours comprising mouse hepatoma cells lacking HIF-1beta (and thereby HIF-1 function) were grown

  18. Low Molecular Weight Fucoidan Inhibits Tumor Angiogenesis through Downregulation of HIF-1/VEGF Signaling under Hypoxia

    Meng-Chuan Chen

    2015-07-01

    Full Text Available Activation of hypoxia-induced hypoxia-inducible factors-1 (HIF-1 plays a critical role in promoting tumor angiogenesis, growth and metastasis. Low molecular weight fucoidan (LMWF is prepared from brown algae, and exhibits anticancer activity. However, whether LMWF attenuates hypoxia-induced angiogenesis in bladder cancer cells and the molecular mechanisms involved remain unclear. This is the first study to demonstrate that LMWF can inhibit hypoxia-stimulated H2O2 formation, HIF-1 accumulation and transcriptional activity vascular endothelial growth factor (VEGF secretion, and the migration and invasion in hypoxic human bladder cancer cells (T24 cells. LMWF also downregulated hypoxia-activated phosphorylation of PI3K/AKT/mTOR/p70S6K/4EBP-1 signaling in T24 cells. Blocking PI3K/AKT or mTOR activity strongly diminished hypoxia-induced HIF-1α expression and VEGF secretion in T24 cells, supporting the involvement of PI3K/AKT/mTOR in the induction of HIF-1α and VEGF. Additionally, LMWF significantly attenuated angiogenesis in vitro and in vivo evidenced by reduction of tube formation of hypoxic human umbilical vascular endothelial cells and blood capillary generation in the tumor. Similarly, administration of LMWF also inhibited the HIF-1α and VEGF expression in vivo, accompanied by a reduction of tumor growth. In summary, under hypoxia conditions, the antiangiogenic activity of LMWF in bladder cancer may be associated with suppressing HIF-1/VEGF-regulated signaling pathway.

  19. Cobaltous chloride and hypoxia inhibit aryl hydrocarbon receptor-mediated responses in breast cancer cells

    Khan, Shaheen; Liu Shengxi; Stoner, Matthew; Safe, Stephen

    2007-01-01

    The aryl hydrocarbon receptor (AhR) is expressed in estrogen receptor (ER)-positive ZR-75 breast cancer cells. Treatment with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induces CYP1A1 protein and mRNA levels and also activates inhibitory AhR-ERα crosstalk associated with hormone-induced reporter gene expression. In ZR-75 cells grown under hypoxia, induction of these AhR-mediated responses by TCDD was significantly inhibited. This was not accompanied by decreased nuclear AhR levels or decreased interaction of the AhR complex with the CYP1A1 gene promoter as determined in a chromatin immunoprecipitation assay. Hypoxia-induced loss of Ah-responsiveness was not associated with induction of hypoxia-inducible factor-1α or other factors that sequester the AhR nuclear translocation (Arnt) protein, and overexpression of Arnt under hypoxia did not restore Ah-responsiveness. The p65 subunit of NFκB which inhibits AhR-mediated transactivation was not induced by hypoxia and was primarily cytosolic in ZR-75 cells grown under hypoxic and normoxic conditions. In ZR-75 cells maintained under hypoxic conditions for 24 h, BRCA1 (an enhancer of AhR-mediated transactivation in breast cancer cells) was significantly decreased and this contributed to loss of Ah-responsiveness. In cells grown under hypoxia for 6 h, BRCA1 was not decreased, but induction of CYP1A1 by TCDD was significantly decreased. Cotreatment of ZR-75 cells with TCDD plus the protein synthesis inhibitor cycloheximide for 6 h enhanced CYP1A1 expression in cells grown under hypoxia and normoxia. These results suggest that hypoxia rapidly induces protein(s) that inhibit Ah-responsiveness and these may be similar to constitutively expressed inhibitors of Ah-responsiveness (under normoxia) that are also inhibited by cycloheximide

  20. Long-term exposure to hypoxia inhibits tumor progression of lung cancer in rats and mice

    Yu, Lunyin; Hales, Charles A

    2011-01-01

    Hypoxia has been identified as a major negative factor for tumor progression in clinical observations and in animal studies. However, the precise role of hypoxia in tumor progression has not been fully explained. In this study, we extensively investigated the effect of long-term exposure to hypoxia on tumor progression in vivo. Rats bearing transplanted tumors consisting of A549 human lung cancer cells (lung cancer tumor) were exposed to hypoxia for different durations and different levels of oxygen. The tumor growth and metastasis were evaluated. We also treated A549 lung cancer cells (A549 cells) with chronic hypoxia and then implanted the hypoxia-pretreated cancer cells into mice. The effect of exposure to hypoxia on metastasis of Lewis lung carcinoma in mice was also investigated. We found that long-term exposure to hypoxia a) significantly inhibited lung cancer tumor growth in xenograft and orthotopic models in rats, b) significantly reduced lymphatic metastasis of the lung cancer in rats and decreased lung metastasis of Lewis lung carcinoma in mice, c) reduced lung cancer cell proliferation and cell cycle progression in vitro, d) decreased growth of the tumors from hypoxia-pretreated A549 cells, e) decreased Na + -K + ATPase α1 expression in hypoxic lung cancer tumors, and f) increased expression of hypoxia inducible factors (HIF1α and HIF2α) but decreased microvessel density in the lung cancer tumors. In contrast to lung cancer, the growth of tumor from HCT116 human colon cancer cells (colon cancer tumor) was a) significantly enhanced in the same hypoxia conditions, accompanied by b) no significant change in expression of Na + -K + ATPase α1, c) increased HIF1α expression (no HIF2α was detected) and d) increased microvessel density in the tumor tissues. This study demonstrated that long-term exposure to hypoxia repressed tumor progression of the lung cancer from A549 cells and that decreased expression of Na + -K + ATPase was involved in hypoxic

  1. Determination of tumour hypoxia with the PET tracer [18F]EF3: improvement of the tumour-to-background ratio in a mouse tumour model

    Christian, Nicolas; Bol, Anne; Bast, Marc de; Labar, Daniel; Lee, John; Mahy, Pierre; Gregoire, Vincent

    2007-01-01

    The 2-(2-nitroimidazol-1-yl)-N-(3,3,3-trifluoropropyl)acetamide (EF3) is a 2-nitroimidazole derivative which undergoes bioreductive activation under hypoxic conditions. Using the PET tracer [ 18 F]EF3 in mice, tumour-to-muscle ratios ranging from 1.3 to 3.5 were observed. This study investigated the impact of various interventions aimed at increasing [ 18 F]EF3 elimination, thus potentially increasing the tumour-to-noise ratio in mice, by increasing the renal filtration rate (spironolactone, furosemide), decreasing tubular re-absorption (metronidazole, ornidazole, amino acid solution) or stimulating gastro-intestinal elimination (phenobarbital). C3H mice were injected i.v. with an average of 12.95 MBq of [ 18 F]EF3. Drugs were injected i.v. 15 min before the tracer or daily 4 days prior to the experiment (phenobarbital). Anaesthetised mice were imaged from 30 to 300 min with a dedicated animal PET (Mosaic, Philips). Regions of interest were delineated around the tumour, bladder, heart, liver and leg muscle. Radioactivity was expressed as a percentage of injected activity per gram of tissue. Ornidazole decreased the urinary excretion and increased the liver uptake of [ 18 F]EF3, but without causing any changes in the other organs. Phenobarbital significantly increased the liver concentration and decreased radioactivity in blood and muscle without affecting the tracer uptake in tumour. Consequently, a small but non-significant increase in tumour-to-noise ratio was observed. Although some effects were observed with other drugs, they did not modify the tumour-to-noise ratio. Only phenobarbital induced a trend toward an increased tumour-to-noise ratio that could possibly be tested in the clinical situation. (orig.)

  2. Determination of tumour hypoxia with the PET tracer [{sup 18}F]EF3: improvement of the tumour-to-background ratio in a mouse tumour model

    Christian, Nicolas; Bol, Anne; Bast, Marc de; Labar, Daniel; Lee, John; Mahy, Pierre; Gregoire, Vincent [Universite Catholique de Louvain, Center for Molecular Imaging and Experimental Radiotherapy, Brussels (Belgium)

    2007-09-15

    The 2-(2-nitroimidazol-1-yl)-N-(3,3,3-trifluoropropyl)acetamide (EF3) is a 2-nitroimidazole derivative which undergoes bioreductive activation under hypoxic conditions. Using the PET tracer [{sup 18}F]EF3 in mice, tumour-to-muscle ratios ranging from 1.3 to 3.5 were observed. This study investigated the impact of various interventions aimed at increasing [{sup 18}F]EF3 elimination, thus potentially increasing the tumour-to-noise ratio in mice, by increasing the renal filtration rate (spironolactone, furosemide), decreasing tubular re-absorption (metronidazole, ornidazole, amino acid solution) or stimulating gastro-intestinal elimination (phenobarbital). C3H mice were injected i.v. with an average of 12.95 MBq of [{sup 18}F]EF3. Drugs were injected i.v. 15 min before the tracer or daily 4 days prior to the experiment (phenobarbital). Anaesthetised mice were imaged from 30 to 300 min with a dedicated animal PET (Mosaic, Philips). Regions of interest were delineated around the tumour, bladder, heart, liver and leg muscle. Radioactivity was expressed as a percentage of injected activity per gram of tissue. Ornidazole decreased the urinary excretion and increased the liver uptake of [{sup 18}F]EF3, but without causing any changes in the other organs. Phenobarbital significantly increased the liver concentration and decreased radioactivity in blood and muscle without affecting the tracer uptake in tumour. Consequently, a small but non-significant increase in tumour-to-noise ratio was observed. Although some effects were observed with other drugs, they did not modify the tumour-to-noise ratio. Only phenobarbital induced a trend toward an increased tumour-to-noise ratio that could possibly be tested in the clinical situation. (orig.)

  3. Cytochrome P450-mediated metabolism of tumour promoters modifies the inhibition of intercellular communication: a modified assay for tumour promotion

    Vang, Ole; Wallin, H.; Doehmer, J.

    1993-01-01

    The role of metabolism of tumour promoters on the inhibition of intercellular communication was investigated in a modified V79 metabolic cooperation system. V79 cells, which stably express different rat cytochrome P450 enzymes (CYP1A1, CYP1A2 or CYP2B1), were used in the metabolic cooperation assay...... B1 and 4-nitrobiphenyl, did not inhibit metabolic cooperation in either V79 cells expressing or cells not expressing cytochrome P450. We conclude that cytochrome P450-associated metabolism plays an important role in the inhibition of gap junctional intercellular communication of some tumour...... promoters. The modified metabolic cooperation assay presented here is valuable for detecting some inhibitory chemicals which have been 'false negative' in previous assays for gap junctional intercellular communication. The assay also discloses that cytochrome P450 metabolism alters intercellular...

  4. Adenoviral gene transfer of angiostatic ATF-BPTI inhibits tumour growth

    Lefesvre, Pierre; Attema, Joline; Bekkum, Dirk van

    2002-01-01

    The outgrowth of new vessels – angiogenesis – in the tumour mass is considered to be a limiting factor of tumour growth. To inhibit the matrix lysis that is part of the tumour angiogenesis, we employed the chimeric protein mhATF-BPTI, composed of the receptor binding part of the urokinase (ATF) linked to an inhibitor of plasmin (BPTI). For delivery, recombinant adenovirus encoding the transgene of interest was injected intravenously or locally into the tumour. The anti tumour effect of this compound was compared to that of human endostatin and of mhATF alone in two different rat bronchial carcinomas growing either as subcutaneous implants or as metastases. Significant inhibition of the tumour growth and decrease of the number of lung metastasis was achieved when the concentration of mhATF-BPTI at the tumour site was above 400 of ng / g tissue. This concentration could be achieved via production by the liver, only if permissive to the recombinant adenovirus. When the tumour cells could be transduced, local delivery of the vector was enough to obtain a response. In the case of metastasis, the capacity of the lung tissue to concentrate the encoded protein was essential to reach the required therapeutic levels. Further, endostatin or mhATF could not reproduce the effects of mhATF-BPTI, at similar concentrations (mhATF) and even at 10-fold higher concentration (endostatin). The ATF-BPTI was shown to inhibit tumour growth of different rat lung tumours when critical concentration was reached. In these tumour models, endostatin or ATF induce almost no tumour response

  5. Quercetin enhances hypoxia-mediated apoptosis via direct inhibition of AMPK activity in HCT116 colon cancer.

    Kim, Hak-Su; Wannatung, Tirawat; Lee, Sooho; Yang, Woo Kyeom; Chung, Sung Hyun; Lim, Jong-Seok; Choe, Wonchae; Kang, Insug; Kim, Sung-Soo; Ha, Joohun

    2012-09-01

    Tumor hypoxia is considered the best validated target in clinical oncology because of its significant contribution to chemotherapy failure and drug resistance. As an approach to target hypoxia, we assessed the potential of quercetin, a flavonoid widely distributed in plants, as a anticancer agent under hypoxic conditions and examined its pharmacological mechanisms by primarily focusing on the role of AMP-activated protein kinase (AMPK). Quercetin significantly attenuated tumor growth in an HCT116 cancer xenograft in vivo model with a substantial reduction of AMPK activity. In a cell culture system, quercetin more dramatically induced apoptosis of HCT116 cancer cells under hypoxic conditions than normoxic conditions, and this was tightly associated with inhibition of hypoxia-induced AMPK activity. An in vitro kinase assay demonstrated that quercetin directly inhibits AMPK activity. Inhibition of AMPK by expressing a dominant-negative form resulted in an increase of apoptosis under hypoxia, and a constitutively active form of AMPK effectively blocked quercetin-induced apoptosis under hypoxia. Collectively, our data suggest that quercetin directly inhibits hypoxia-induced AMPK, which plays a protective role against hypoxia. Quercetin also reduced the activity of hypoxia-inducible factor-1 (HIF-1), a major transcription factor for adaptive cellular response to hypoxia. Moreover, quercetin sensitized HCT116 cancer cells to the anticancer drugs cisplatin and etoposide under hypoxic conditions. Our findings suggest that AMPK may serve as a novel target for overcoming tumor hypoxia-associated negative aspects.

  6. Proton pump inhibitor-induced tumour cell death by inhibition of a detoxification mechanism.

    Fais, S

    2010-05-01

    This review presents a possible new approach against cancer, as represented by inhibition of proton pumps, a mechanism used by tumour cells to avoid intracellular accumulation of toxic substances. Proton pump inhibitors (PPIs) belong to a family of pro-drugs that are currently used in the treatment of peptic diseases needing acidity to be activated. PPIs target the acidic tumour mass, where they are metabolized, thus blocking proton traffic. Proton pump inhibition triggers a rapid cell death as a result of intracellular acidification, caspase activation and early accumulation of reactive oxygen species into tumour cells. As a whole, the devastating effect of PPIs on tumour cells suggest the triggering of a fatal cell toxification. Many human tumours, including melanoma, osteosarcoma, lymphomas and various adenocarcinomas are responsive to PPIs. This appears highly conceivable, in as much as almost all human tumours are acidic and express high levels of proton pumps. Paradoxically, metastatic tumours appear to be more responsive to PPIs being more acidic than the majority of primary tumours. However, two clinical trials test the effectiveness of PPIs in chemosensitizing melanoma and osteosarcoma patients. Indeed, tumour acidity represents a very potent mechanism of chemoresistance. A majority of cytotoxic agents, being weak bases, are quickly protonated outside and do not enter the cells, thus preventing drugs to reach specific cellular targets. Clinical data will provide the proof of concept on the use of PPIs as a new class of antitumour agent with a very low level of systemic toxicity as compared with standard chemotherapeutic agents.

  7. Inhibition of platelet-tumour cell interaction with ibrutinib reduces ...

    BTK) inhibitor, ibrutinib, in tumour cell-platelet crosstalk in lung cancer. Methods: Human lung cancer cells A549 were treated with ibrutinib or DMSO. mRNA expression was assessed using reverse transcription-quantitative polymerase chain ...

  8. Inducible repair and the two forms of tumour hypoxia - time for a paradigm shift

    Denekamp, J.; Dasu, A.

    1999-01-01

    Clinical experience shows that there is a therapeutic window between 60 and 70 Gy where many tumours are eradicated, but the function of the adjacent normal tissues is preserved. This implies much more cell kill in the tumour than is acceptable in the normal tissue. An SF 2 of 0.5 or lower is needed to account for the eradication of all tumour cells, while an SF 2 of 0.8 or higher is needed to explain why these doses are tolerated by normal tissues. No such systematic difference is known between the intrinsic sensitivity of well-oxygenated normal and tumour cells. The presence of radioresistant hypoxic cells in tumours makes it even more difficult to understand the clinical success. However, there is experimental evidence that starved cells lose their repair competence as a result of the depletion of cellular energy charge. MRS studies have shown that low ATP levels are a characteristic feature of solid tumours in rodents and man. In this paper we incorporate the concept of repair incompetence in starving, chronically hypoxic cells. The increased sensitivity of such cells has been derived from an analysis of mammalian cell lines showing inducible repair. It is proportional to the SF 2 and highest in resistant cells. The distinction between acutely hypoxic radioresistant cells and chronically hypoxic radiosensitive cells provides the key to the realistic modelling of successful radiotherapy. It also opens new conceptual approaches to radiotherapy. We conclude that it is essential to distinguish between these two kinds of hypoxic cells in predictive assays and models. (orig.)

  9. Tumour tissue microenvironment can inhibit dendritic cell maturation in colorectal cancer.

    Michielsen, Adriana J

    2011-01-01

    Inflammatory mediators in the tumour microenvironment promote tumour growth, vascular development and enable evasion of anti-tumour immune responses, by disabling infiltrating dendritic cells. However, the constituents of the tumour microenvironment that directly influence dendritic cell maturation and function are not well characterised. Our aim was to identify tumour-associated inflammatory mediators which influence the function of dendritic cells. Tumour conditioned media obtained from cultured colorectal tumour explant tissue contained high levels of the chemokines CCL2, CXCL1, CXCL5 in addition to VEGF. Pre-treatment of monocyte derived dendritic cells with this tumour conditioned media inhibited the up-regulation of CD86, CD83, CD54 and HLA-DR in response to LPS, enhancing IL-10 while reducing IL-12p70 secretion. We examined if specific individual components of the tumour conditioned media (CCL2, CXCL1, CXCL5) could modulate dendritic cell maturation or cytokine secretion in response to LPS. VEGF was also assessed as it has a suppressive effect on dendritic cell maturation. Pre-treatment of immature dendritic cells with VEGF inhibited LPS induced upregulation of CD80 and CD54, while CXCL1 inhibited HLA-DR. Interestingly, treatment of dendritic cells with CCL2, CXCL1, CXCL5 or VEGF significantly suppressed their ability to secrete IL-12p70 in response to LPS. In addition, dendritic cells treated with a combination of CXCL1 and VEGF secreted less IL-12p70 in response to LPS compared to pre-treatment with either cytokine alone. In conclusion, tumour conditioned media strongly influences dendritic cell maturation and function.

  10. Cinnamic aldehyde suppresses hypoxia-induced angiogenesis via inhibition of hypoxia-inducible factor-1α expression during tumor progression.

    Bae, Woom-Yee; Choi, Jae-Sun; Kim, Ja-Eun; Jeong, Joo-Won

    2015-11-01

    During tumor progression, hypoxia-inducible factor 1 (HIF-1) plays a critical role in tumor angiogenesis and tumor growth by regulating the transcription of several genes in response to a hypoxic environment and changes in growth factors. This study was designed to investigate the effects of cinnamic aldehyde (CA) on tumor growth and angiogenesis and the mechanisms underlying CA's anti-angiogenic activities. We found that CA administration inhibits tumor growth and blocks tumor angiogenesis in BALB/c mice. In addition, CA treatment decreased HIF-1α protein expression and vascular endothelial growth factor (VEGF) expression in mouse tumors and Renca cells exposed to hypoxia in vitro. Interestingly, CA treatment did not affect the stability of von Hippel-Lindau protein (pVHL)-associated HIF-1α and CA attenuated the activation of mammalian target of rapamycin (mTOR) pathway. Collectively, these findings strongly indicate that the anti-angiogenic activity of CA is, at least in part, regulated by the mTOR pathway-mediated suppression of HIF-1α protein expression and these findings suggest that CA may be a potential drug for human cancer therapy. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Hypoxia inhibits the growth, differentiation and bone-forming capacity of rat osteoblasts

    Utting, J.C.; Robins, S.P.; Brandao-Burch, A.; Orriss, I.R.; Behar, J.; Arnett, T.R.

    2006-01-01

    We investigated the effect of hypoxia on rat osteoblast function in long-term primary cultures. Reduction of pO 2 from 20% to 5% and 2% decreased formation of mineralized bone nodules 1.7-fold and 11-fold, respectively. When pO 2 was reduced further to 0.2%, bone nodule formation was almost abolished. The inhibitory effect of hypoxia on bone formation was partly due to decreased osteoblast proliferation, as measured by 3 H-thymidine incorporation. Hypoxia also sharply reduced osteoblast alkaline phosphatase (ALP) activity and expression of mRNAs for ALP and osteocalcin, suggesting inhibition of differentiation to the osteogenic phenotype. Hypoxia did not increase the apoptosis of osteoblasts but induced a reversible state of quiescence. Transmission electron microscopy revealed that collagen fibrils deposited by osteoblasts cultured in 2% O 2 were less organized and much less abundant than in 20% O 2 cultures. Furthermore, collagen produced by hypoxic osteoblasts contained a lower percentage of hydroxylysine residues and exhibited an increased sensitivity to pepsin degradation. These data demonstrate the absolute oxygen requirement of osteoblasts for successful bone formation and emphasize the importance of the vasculature in maintaining bone health. We recently showed that hypoxia also acts in a reciprocal manner as a powerful stimulator of osteoclast formation. Considered together, our results help to explain the bone loss that occurs at the sites of fracture, tumors, inflammation and infection, and in individuals with vascular disease or anemia

  12. Evaluation of tumour hypoxia during radiotherapy using [{sup 18}F]HX4 PET imaging and blood biomarkers in patients with head and neck cancer

    Zegers, Catharina M.L.; Hoebers, Frank J.P.; Elmpt, Wouter van; Oellers, Michel C.; Eekers, Danielle; Balmaekers, Leo; Arts-Pechtold, Marlies; Lambin, Philippe [Maastricht University Medical Centre, Department of Radiation Oncology (MAASTRO), GROW - School for Oncology and Developmental Biology, Maastricht (Netherlands); Bons, Judith A. [Maastricht University Medical Centre, Central Diagnostic Laboratory, Maastricht (Netherlands); Troost, Esther G.C. [Maastricht University Medical Centre, Department of Radiation Oncology (MAASTRO), GROW - School for Oncology and Developmental Biology, Maastricht (Netherlands); Helmholtz Zentrum Dresden-Rossendorf, Dresden (Germany); Technische Universitaet Dresden, OncoRay, Department of Radiation Oncology, Medical Faculty and University Hospital Carl Gustav Carus, Dresden (Germany); Mottaghy, Felix M. [Maastricht University Medical Centre, Department of Nuclear Medicine, Maastricht (Netherlands); RWTH Aachen University, University Hospital, Department of Nuclear Medicine, Aachen (Germany)

    2016-11-15

    Increased tumour hypoxia is associated with a worse overall survival in patients with head and neck squamous cell carcinoma (HNSCC). The aims of this study were to evaluate treatment-associated changes in [{sup 18}F]HX4-PET, hypoxia-related blood biomarkers, and their interdependence. [{sup 18}F]HX4-PET/CT scans of 20 patients with HNSCC were acquired at baseline and after ±20 Gy of radiotherapy. Within the gross-tumour-volumes (GTV; primary and lymph nodes), mean and maximum standardized uptake values, the hypoxic fraction (HF) and volume (HV) were calculated. Also, the changes in spatial uptake pattern were evaluated using [{sup 18}F]HX4-PET/CT imaging. For all patients, the plasma concentration of CAIX, osteopontin and VEGF was assessed. At baseline, tumour hypoxia was detected in 69 % (22/32) of the GTVs. During therapy, we observed a significant decrease in all image parameters. The HF decreased from 21.7 ± 19.8 % (baseline) to 3.6 ± 10.0 % (during treatment; P < 0.001). Only two patients had a HV > 1 cm{sup 3} during treatment, which was located for >98 % within the baseline HV. During treatment, no significant changes in plasma CAIX or VEGF were observed, while osteopontin was increased. [{sup 18}F]HX4-PET/CT imaging allows monitoring changes in hypoxia during (chemo)radiotherapy whereas the blood biomarkers were not able to detect a treatment-associated decrease in hypoxia. (orig.)

  13. Effects of employing a 10B-carrier and manipulating intratumour hypoxia on local tumour response and lung metastatic potential in boron neutron capture therapy

    Masunaga, S; Sakurai, Y; Tanaka, H; Suzuki, M; Liu, Y; Kondo, N; Maruhashi, A; Kinashi, Y; Ono, K

    2012-01-01

    Objectives To evaluate the effects of employing a 10B-carrier and manipulating intratumour hypoxia on local tumour response and lung metastatic potential in boron neutron capture therapy (BNCT) by measuring the response of intratumour quiescent (Q) cells. Methods B16-BL6 melanoma tumour-bearing C57BL/6 mice were continuously given 5-bromo-2′-deoxyuridine (BrdU) to label all proliferating (P) cells. The tumours received reactor thermal neutron beam irradiation following the administration of a 10B-carrier [L-para-boronophenylalanine-10B (BPA) or sodium mercaptoundecahydrododecaborate-10B (BSH)] in combination with an acute hypoxia-releasing agent (nicotinamide) or mild temperature hyperthermia (MTH). Immediately after the irradiation, cells from some tumours were isolated and incubated with a cytokinesis blocker. The responses of the Q and total (P+Q) cell populations were assessed based on the frequency of micronuclei using immunofluorescence staining for BrdU. In other tumour-bearing mice, macroscopic lung metastases were enumerated 17 days after irradiation. Results BPA-BNCT increased the sensitivity of the total tumour cell population more than BSH-BNCT. However, the sensitivity of Q cells treated with BPA was lower than that of BSH-treated Q cells. With or without a 10B–carrier, MTH enhanced the sensitivity of the Q cell population. Without irradiation, nicotinamide treatment decreased the number of lung metastases. With irradiation, BPA-BNCT, especially in combination with nicotinamide treatment, showed the potential to reduce the number of metastases more than BSH-BNCT. Conclusion BSH-BNCT in combination with MTH improves local tumour control, while BPA-BNCT in combination with nicotinamide may reduce the number of lung metastases. PMID:22391496

  14. Potent inhibition of tumoral hypoxia-inducible factor 1α by albendazole

    Pourgholami, Mohammad H; Cai, Zhao Y; Badar, Samina; Wangoo, Kiran; Poruchynsky, Marianne S; Morris, David L

    2010-01-01

    Emerging reports suggest resistance, increased tumor invasiveness and metastasis arising from treatment with drugs targeting vascular endothelial growth factor (VEGF). It is believed that increased tumoral hypoxia plays a prominent role in the development of these phenomena. Inhibition of tumoral hypoxia inducible factor (HIF-1α) is thus becoming an increasingly attractive therapeutic target in the treatment of cancer. We hypothesized that the anti-VEGF effect of albendazole (ABZ) could be mediated through inhibition of tumoral HIF-1α. In vitro, the effects of ABZ on HIF-1α levels in human ovarian cancer cells (OVCAR-3) were investigated using hypoxic chamber or desferrioxamine (DFO) induced-hypoxia. In vivo, the effects of ABZ (150 mg/kg, i.p., single dose) on the tumor levels of HIF-1α and VEGF protein and mRNA were investigated by western blotting, RT-PCR and real time-PCR. In vitro, ABZ inhibited cellular HIF-1α protein accumulation resulting from placement of cells under hypoxic chamber or exposure to DFO. In vivo, tumors excised from vehicle treated mice showed high levels of both HIF-1α and VEGF. Whereas, tumoral HIF-1α and VEGF protein levels were highly suppressed in ABZ treated mice. Tumoral VEGFmRNA (but not HIF-1αmRNA) was also found to be highly suppressed by ABZ. These results demonstrate for the first time the effects of an acute dose of ABZ in profoundly suppressing both HIF-1α and VEGF within the tumor. This dual inhibition may provide additional value in inhibiting angiogenesis and be at least partially effective in inhibiting tumoral HIF-1α surge, tumor invasiveness and metastasis

  15. [Inhibition of gap junctional intercellular communication protects astrocytes from hypoxia/reoxygenation injury].

    Tong, Xu-Hui; Gu, Yu-Chen; Jiao, Hao; Yu, Li; Dong, Shu-Ying

    2015-01-01

    To investigate the effects of inhibiting gap junctional intercellular communication on hypoxia/reoxygenation injury in astrocytes. Primary cultured cerebral cortical astrocytes of neonate rats were divided into normal control group, hypoxia reoxygenation injury group and 18-α-glycyrrhetinic acid and oleamide (gap junctional intercellular channel inhibitors) group. The gap junction intercellular communication was determined by Parachute assay. The viability of astrocyes was detected by MTT assay. The apoptosis of astrocytes were detected with annexin V/PI and Hoechst 33258 staining. Compared with the normal control group, the gap junctional function of astrocytes was increased significantly in ischemia/reperfusion group (Pastrocytes decreased significantly (Pastrocytes in18-α-glycyrrhetinic acid and oleamide group decreased significantly (Pastrocytes increased significantly (Pastrocytes.

  16. Regulation of mRNA translation influences hypoxia tolerance

    Koritzinsky, M.; Wouters, B.G.; Koumenis, C.

    2003-01-01

    Hypoxia is a heterogenous but common characteristic of human tumours and poor oxygenation is associated with poor prognosis. We believe that the presence of viable hypoxic tumor cells reflects in part an adaptation and tolerance of these cells to oxygen deficiency. Since oxidative phosphorylation is compromized during hypoxia, adaptation may involve both the upregulation of glycolysis as well as downregulation of energy consumption. mRNA translation is one of the most energy costly cellular processes, and we and others have shown that global mRNA translation is rapidly inhibited during hypoxia. However, some mRNAs, including those coding for HIF-1 α and VEGF, remain efficiently translated during hypoxia. Clearly, the mechanisms responsible for the overall inhibition of translation during hypoxia does not compromize the translation of certain hypoxia-induced mRNA species. We therefore hypothesize that the inhibition of mRNA translation serves to promote hypoxia tolerance in two ways: i) through conservation of energy and ii) through differential gene expression involved in hypoxia adaptation. We have recently identified two pathways that are responsible for the global inhibition of translation during hypoxia. The phosphorylation of the eukaryotic initiation factor eIF2 α by the ER resident kinase PERK results in down-regulation of protein synthesis shortly after the onset of hypoxia. In addition, the initiation complex eIF4F is disrupted during long lasting hypoxic conditions. The identification of the molecular pathways responsible for the inhibition of overall translation during hypoxia has rendered it possible to investigate their importance for hypoxia tolerance. We have found that mouse embryo fibroblasts that are knockout for PERK and therefore not able to inhibit protein synthesis efficiently during oxygen deficiency are significantly less tolerant to hypoxia than their wildtype counterparts. We are currently also investigating the functional significance

  17. Overexpression of ERβ is sufficient to inhibit hypoxia-inducible factor-1 transactivation

    Park, Choa; Lee, YoungJoo

    2014-01-01

    Highlights: • We examined the effect of ERβ specific ligand on HIF-1 inhibition. • DPN down-regulates the ARNT protein levels in PC3 cells. • DPN did not show additional effect in ERβ transfected MCF-7 cells. • Our study shows that unliganded ERβ is sufficient to inhibit HIF-1 in systems of overexpression. - Abstract: Estrogen receptor (ER) β is predicted to play an important role in the prevention of breast cancer development and progression. We have previously shown that ERβ suppresses hypoxia inducible factor (HIF)-1-mediated transcription through aryl hydrocarbon receptor nuclear translocator (ARNT) degradation via ubiquitination processes. In this study, we attempted to examine the effect of ERβ specific ligand on HIF-1 inhibition in ERβ positive PC3 cells and ERβ transfected MCF-7 cells. ERβ specific agonist diarylpropionitrile (DPN) stimulated estrogen response element (ERE)-luciferase activity in a similar fashion to estradiol in PC3 cells. We observed that DPN down-regulates the ARNT protein levels leading to an attenuation of hypoxia-induced hypoxia response element (HRE)-driven luciferase reporter gene activation in PC3 cells. Treatment of DPN reduced vascular endothelial growth factor (VEGF) expression and co-treatment with ERβ specific antagonist PHTPP abrogated the effect in PC3 cells. We then examined the effect of DPN in ERβ transfected MCF-7 cells. HIF-1 transcriptional activity repression by ERβ was not further reduced by DPN, as examined by HRE-driven luciferase assays. Expression of ERβ significantly decreased VEGF secretion and ARNT expression under hypoxic conditions. However, DPN did not additionally affect this suppression in MCF-7 cells transfected with ERβ. This result shows that unliganded ERβ is sufficient to inhibit HIF-1 in systems of overexpression

  18. Overexpression of ERβ is sufficient to inhibit hypoxia-inducible factor-1 transactivation

    Park, Choa; Lee, YoungJoo, E-mail: yjlee@sejong.ac.kr

    2014-07-18

    Highlights: • We examined the effect of ERβ specific ligand on HIF-1 inhibition. • DPN down-regulates the ARNT protein levels in PC3 cells. • DPN did not show additional effect in ERβ transfected MCF-7 cells. • Our study shows that unliganded ERβ is sufficient to inhibit HIF-1 in systems of overexpression. - Abstract: Estrogen receptor (ER) β is predicted to play an important role in the prevention of breast cancer development and progression. We have previously shown that ERβ suppresses hypoxia inducible factor (HIF)-1-mediated transcription through aryl hydrocarbon receptor nuclear translocator (ARNT) degradation via ubiquitination processes. In this study, we attempted to examine the effect of ERβ specific ligand on HIF-1 inhibition in ERβ positive PC3 cells and ERβ transfected MCF-7 cells. ERβ specific agonist diarylpropionitrile (DPN) stimulated estrogen response element (ERE)-luciferase activity in a similar fashion to estradiol in PC3 cells. We observed that DPN down-regulates the ARNT protein levels leading to an attenuation of hypoxia-induced hypoxia response element (HRE)-driven luciferase reporter gene activation in PC3 cells. Treatment of DPN reduced vascular endothelial growth factor (VEGF) expression and co-treatment with ERβ specific antagonist PHTPP abrogated the effect in PC3 cells. We then examined the effect of DPN in ERβ transfected MCF-7 cells. HIF-1 transcriptional activity repression by ERβ was not further reduced by DPN, as examined by HRE-driven luciferase assays. Expression of ERβ significantly decreased VEGF secretion and ARNT expression under hypoxic conditions. However, DPN did not additionally affect this suppression in MCF-7 cells transfected with ERβ. This result shows that unliganded ERβ is sufficient to inhibit HIF-1 in systems of overexpression.

  19. Inhibition of the H3K9 methyltransferase G9A attenuates oncogenicity and activates the hypoxia signaling pathway

    Ho, Jolene Caifeng; Abdullah, Lissa Nurrul; Pang, Qing You; Jha, Sudhakar; Chow, Edward Kai-Hua; Yang, Henry; Kato, Hiroyuki; Ueda, Jun

    2017-01-01

    Epigenetic mechanisms play important roles in the regulation of tumorigenesis, and hypoxia-induced epigenetic changes may be critical for the adaptation of cancer cells to the hypoxic microenvironment of solid tumors. Previously, we showed that loss-of-function of the hypoxia-regulated H3K9 methyltransferase G9A attenuates tumor growth. However, the mechanisms by which blockade of G9A leads to a tumor suppressive effect remain poorly understood. We show that G9A is highly expressed in breast cancer and is associated with poor patient prognosis, where it may function as a potent oncogenic driver. In agreement with this, G9A inhibition by the small molecule inhibitor, BIX-01294, leads to increased cell death and impaired cell migration, cell cycle and anchorage-independent growth. Interestingly, whole transcriptome analysis revealed that genes involved in diverse cancer cell functions become hypoxia-responsive upon G9A inhibition. This was accompanied by the upregulation of the hypoxia inducible factors HIF1α and HIF2α during BIX-01294 treatment even in normoxia that may facilitate the tumor suppressive effects of BIX-01294. HIF inhibition was able to reverse some of the transcriptional changes induced by BIX-01294 in hypoxia, indicating that the HIFs may be important drivers of these derepressed target genes. Therefore, we show that G9A is a key mediator of oncogenic processes in breast cancer cells and G9A inhibition by BIX-01294 can successfully attenuate oncogenicity even in hypoxia. PMID:29145444

  20. Furan- and Thiophene-2-Carbonyl Amino Acid Derivatives Activate Hypoxia-Inducible Factor via Inhibition of Factor Inhibiting Hypoxia-Inducible Factor-1

    Shin-ichi Kawaguchi

    2018-04-01

    Full Text Available Induction of a series of anti-hypoxic proteins protects cells during exposure to hypoxic conditions. Hypoxia-inducible factor-α (HIF-α is a major transcription factor that orchestrates this protective effect. To activate HIF exogenously, without exposing cells to hypoxic conditions, many small-molecule inhibitors targeting prolyl hydroxylase domain-containing protein have been developed. In addition, suppression of factor inhibiting HIF-1 (FIH-1 has also been shown to have the potential to activate HIF-α. However, few small-molecule inhibitors of FIH-1 have been developed. In this study, we synthesized a series of furan- and thiophene-2-carbonyl amino acid derivatives having the potential to inhibit FIH-1. The inhibitory activities of these compounds were evaluated in SK-N-BE(2c cells by measuring HIF response element (HRE promoter activity. Several furan- and thiophene-2-carbonyl amino acid derivatives inhibited FIH-1 based on correlations among the docking score of the FIH-1 active site, the chemical structure of the compounds, and biological HIF-α/HRE transcriptional activity.

  1. Deregulation of cap-dependent mRNA translation increases tumour radiosensitivity through reduction of the hypoxic fraction

    Rouschop, Kasper M.A.; Dubois, Ludwig; Schaaf, Marco B.E.; Beucken, Twan van den; Lieuwes, Natasja; Keulers, Tom G.H.; Savelkouls, Kim G.M.; Bussink, Johan; Kogel, Albert J. van der; Koritzinsky, Marianne; Wouters, Bradly G.

    2011-01-01

    Background and purpose: Tumour hypoxia is an important limiting factor in the successful treatment of cancer. Adaptation to hypoxia includes inhibition of mTOR, causing scavenging of eukaryotic initiation factor 4E (eIF4E), the rate-limiting factor for cap-dependent translation. The aim of this study was to determine the effect of preventing mTOR-dependent translation inhibition on hypoxic cell survival and tumour sensitivity towards irradiation. Material and methods: The effect of eIF4E-overexpression on cell proliferation, hypoxia-tolerance, and radiation sensitivity was assessed using isogenic, inducible U373 and HCT116 cells. Results: We found that eIF4E-overexpression significantly enhanced proliferation of cells under normal conditions, but not during hypoxia, caused by increased cell death during hypoxia. Furthermore, eIF4E-overexpression stimulated overall rates of tumour growth, but resulted in selective loss of hypoxic cells in established tumours and increased levels of necrosis. This markedly increased overall tumour sensitivity to irradiation. Conclusions: Our results demonstrate that hypoxia induced inhibition of translational control through regulation of eIF4E is an important mediator of hypoxia tolerance and radioresistance of tumours. These data also demonstrate that deregulation of metabolic pathways such as mTOR can influence the proliferation and survival of tumour cells experiencing metabolic stress in opposite ways of nutrient replete cells.

  2. Zeaxanthin Inhibits Hypoxia-Induced VEGF Secretion by RPE Cells through Decreased Protein Levels of Hypoxia-Inducible Factors-1α

    Richard Rosen

    2015-01-01

    Full Text Available Hypoxia is the most important stimulus leading to upregulation of VEGF in the retina and this is caused by accumulation of hypoxia-inducible factors-1α (HIF-1α protein. The effects of zeaxanthin, a natural phytochemical, on the VEGF and HIF-1α expression in the primary culture of human retinal pigment epithelial (RPE cells were studied. An in vitro RPE cell hypoxia model was established by placing cells under 1% oxygen pressure or by adding cobalt chloride (CoCl2 to the culture medium. RPE cells and conditioned media were collected from cultures treated with and without zeaxanthin under normoxic and hypoxic conditions. VEGF and HIF-1α protein and RNA levels were measured by ELISA kits and RT-PCR, respectively. Hypoxia caused a significant increase of VEGF expression and accumulation of HIF-1α in RPE cells. Zeaxanthin at 50–150 μM significantly inhibited the expression of VEGF and accumulation of HIF-1α protein caused by hypoxia but did not affect expression of VEGF and HIF-1α under normoxic conditions. This is the first report on the effect of zeaxanthin on VEGF and HIF-1α levels in cultured RPE cells and suggests that zeaxanthin may have potential value in the prevention and treatment of various retinal diseases associated with vascular leakage and neovascularization.

  3. Recombinant adeno-associated virus-delivered hypoxia-inducible stanniocalcin-1 expression effectively inhibits hypoxia-induced cell apoptosis in cardiomyocytes.

    Shi, Xin; Wang, Jianzhong; Qin, Yan

    2014-12-01

    Ischemia/hypoxia-induced oxidative stress is detrimental for the survival of cardiomyocytes and cardiac function. Stanniocalcin-1 (STC-1), a glycoprotein, has been found to play an inhibitory role in the production of reactive oxygen species (ROS). Here, we speculated that the overexpression of STC-1 might alleviate oxidative damage in cardiomyocytes under conditions of hypoxia. To control the expression of STC-1 in hypoxia, we constructed a recombinant adeno-associated virus (AAV) carrying the hypoxia-responsive element (HRE) to mediate hypoxia induction. Cardiomyocytes were infected with AAV-HRE-STC-1 and cultured in normoxic or hypoxic conditions, and STC-1 overexpression was only detected in hypoxic cultured cardiomyocytes by using quantitative real-time polymerase chain reaction and Western blot analysis. Using the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, AAV-HRE-STC-1 infection was shown to significantly enhance cell survival under hypoxia. Hypoxia-induced cell apoptosis was inhibited by AAV-HRE-STC-1 infection by using the Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide apoptosis assay. Moreover, the proapoptotic protein Caspase-3 and anti-apoptotic protein Bcl-2, which were dysregulated by hypoxia, were reversed by AAV-HRE-STC-1 infection. AAV-HRE-STC-1-mediated STC-1 overexpression markedly inhibited ROS production in cardiomyocytes cultured under hypoxic conditions. AAV-HRE-STC-1 infection significantly upregulated uncoupled protein 3 (UCP3), whereas silencing of UCP3 blocked the inhibitory effect of AAV-HRE-STC-1 on ROS production. In contrast, AAV-HRE-STC-1 infection had no effect on UCP2, and knockdown of UCP2 did not block the inhibitory effect of AAV-HRE-STC-1 on ROS production in the cardiomyocytes cultured under hypoxic conditions. Taken together, STC1 activates antioxidant pathway in cardiomyocytes through the induction of UCP3, implying that AAV-HRE-STC-1 has potential in the treatment of ischemic

  4. The histone deacetylase inhibitor, Vorinostat, represses hypoxia inducible factor 1 alpha expression through translational inhibition.

    Darren M Hutt

    Full Text Available Hypoxia inducible factor 1α (HIF-1α is a master regulator of tumor angiogenesis being one of the major targets for cancer therapy. Previous studies have shown that Histone Deacetylase Inhibitors (HDACi block tumor angiogenesis through the inhibition of HIF-1α expression. As such, Vorinostat (Suberoylanilide Hydroxamic Acid/SAHA and Romidepsin, two HDACis, were recently approved by the Food and Drug Administration (FDA for the treatment of cutaneous T cell lymphoma. Although HDACis have been shown to affect HIF-1α expression by modulating its interactions with the Hsp70/Hsp90 chaperone axis or its acetylation status, the molecular mechanisms by which HDACis inhibit HIF-1α expression need to be further characterized. Here, we report that the FDA-approved HDACi Vorinostat/SAHA inhibits HIF-1α expression in liver cancer-derived cell lines, by a new mechanism independent of p53, prolyl-hydroxylases, autophagy and proteasome degradation. We found that SAHA or silencing of HDAC9 mechanism of action is due to inhibition of HIF-1α translation, which in turn, is mediated by the eukaryotic translation initiation factor--eIF3G. We also highlighted that HIF-1α translation is dramatically inhibited when SAHA is combined with eIF3H silencing. Taken together, we show that HDAC activity regulates HIF-1α translation, with HDACis such as SAHA representing a potential novel approach for the treatment of hepatocellular carcinoma.

  5. Phosphorylation of eIF2α is required for mRNA translation inhibition and survival during moderate hypoxia

    Koritzinsky, Marianne; Rouschop, Kasper M.A.; Beucken, Twan van den; Magagnin, Michael G.; Savelkouls, Kim; Lambin, Philippe; Wouters, Bradly G.

    2007-01-01

    Abstracts: Background and purpose: Human tumors are characterized by temporal fluctuations in oxygen tension. The biological pathways that respond to the dynamic tumor microenvironment represent potential molecular targets for cancer therapy. Anoxic conditions result in eIF2α dependent inhibition of overall mRNA translation, differential gene expression, hypoxia tolerance and tumor growth. The signaling pathway which governs eIF2α phosphorylation has therefore emerged as a potential molecular target. In this study, we investigated the role of eIF2α in regulating mRNA translation and hypoxia tolerance during moderate hypoxia. Since other molecular pathways that regulate protein synthesis are frequently mutated in cancer, we also assessed mRNA translation in a panel of cell lines from different origins. Materials and methods: Immortalized human fibroblast, transformed mouse embryo fibroblasts (MEFs) and cells from six cancer cell lines were exposed to 0.2% or 0.0% oxygen. We assayed global mRNA translation efficiency by polysome analysis, as well as proliferation and clonogenic survival. The role of eIF2α was assessed in MEFs harboring a homozygous inactivating mutation (S51A) as well as in U373-MG cells overexpressing GADD34 (C-term) under a tetracycline-dependent promoter. The involvement of eIF4E regulation was investigated in HeLa cells stably expressing a short hairpin RNA (shRNA) targeting 4E-BP1. Results: All cells investigated inhibited mRNA translation severely in response to anoxia and modestly in response to hypoxia. Two independent genetic cell models demonstrated that inhibition of mRNA translation in response to moderate hypoxia was dependent on eIF2α phosphorylation. Disruption of eIF2α phosphorylation caused sensitivity to hypoxia and anoxia. Conclusions: Disruption of eIF2α phosphorylation is a potential target for hypoxia-directed molecular cancer therapy

  6. Enhancement of hypoxia-activated prodrug TH-302 anti-tumor activity by Chk1 inhibition.

    Meng, Fanying; Bhupathi, Deepthi; Sun, Jessica D; Liu, Qian; Ahluwalia, Dharmendra; Wang, Yan; Matteucci, Mark D; Hart, Charles P

    2015-05-21

    The hypoxia-activated prodrug TH-302 is reduced at its nitroimidazole group and selectively under hypoxic conditions releases the DNA cross-linker bromo-isophosphoramide mustard (Br-IPM). Here, we have explored the effect of Chk1 inhibition on TH-302-mediated pharmacological activities. We employed in vitro cell viability, DNA damage, cellular signaling assays and the in vivo HT29 human tumor xenograft model to study the effect of Chk1inhibition on TH-302 antitumor activities. TH-302 cytotoxicity is greatly enhanced by Chk1 inhibition in p53-deficient but not in p53-proficient human cancer cell lines. Chk1 inhibitors reduced TH-302-induced cell cycle arrest via blocking TH-302-induced decrease of phosphorylation of histone H3 and increasing Cdc2-Y15 phosphorylation. Employing the single-cell gel electrophoresis (comet) assay, we observed a potentiation of the TH-302 dependent tail moment. TH-302 induced γH2AX and apoptosis were also increased upon the addition of Chk1 inhibitor. Potentiation of TH-302 cytotoxicity by Chk1 inhibitor was only observed in cell lines proficient in, but not deficient in homology-directed DNA repair. We also show that combination treatment led to lowering of Rad51 expression levels as compared to either agent alone. In vivo data demonstrate that Chk1 inhibitor enhances TH-302 anti-tumor activity in p53 mutant HT-29 human tumor xenografts, supporting the hypothesis that these in vitro results can translate to enhanced in vivo efficacy of the combination. TH-302-mediated in vitro and in vivo anti-tumor activities were greatly enhanced by the addition of Chk1 inhibitors. The preclinical data presented in this study support a new approach for the treatment of p53-deficient hypoxic cancers by combining Chk1 inhibitors with the hypoxia-activated prodrug TH-302.

  7. Identifying novel hypoxia-associated markers of chemoresistance in ovarian cancer.

    McEvoy, Lynda M

    2015-01-01

    Ovarian cancer is associated with poor long-term survival due to late diagnosis and development of chemoresistance. Tumour hypoxia is associated with many features of tumour aggressiveness including increased cellular proliferation, inhibition of apoptosis, increased invasion and metastasis, and chemoresistance, mostly mediated through hypoxia-inducible factor (HIF)-1α. While HIF-1α has been associated with platinum resistance in a variety of cancers, including ovarian, relatively little is known about the importance of the duration of hypoxia. Similarly, the gene pathways activated in ovarian cancer which cause chemoresistance as a result of hypoxia are poorly understood. This study aimed to firstly investigate the effect of hypoxia duration on resistance to cisplatin in an ovarian cancer chemoresistance cell line model and to identify genes whose expression was associated with hypoxia-induced chemoresistance.

  8. Deregulation of cap-dependent mRNA translation increases tumour radiosensitivity through reduction of the hypoxic fraction

    Rouschop, K.M.; Dubois, L.; Schaaf, M.B.; Beucken, T. van den; Lieuwes, N.; Keulers, T.G.; Savelkouls, K.G.; Bussink, J.; Kogel, A.J. van der; Koritzinsky, M.; Wouters, B.G.

    2011-01-01

    BACKGROUND AND PURPOSE: Tumour hypoxia is an important limiting factor in the successful treatment of cancer. Adaptation to hypoxia includes inhibition of mTOR, causing scavenging of eukaryotic initiation factor 4E (eIF4E), the rate-limiting factor for cap-dependent translation. The aim of this

  9. The Factor Inhibiting HIF Asparaginyl Hydroxylase Regulates Oxidative Metabolism and Accelerates Metabolic Adaptation to Hypoxia.

    Sim, Jingwei; Cowburn, Andrew S; Palazon, Asis; Madhu, Basetti; Tyrakis, Petros A; Macías, David; Bargiela, David M; Pietsch, Sandra; Gralla, Michael; Evans, Colin E; Kittipassorn, Thaksaon; Chey, Yu C J; Branco, Cristina M; Rundqvist, Helene; Peet, Daniel J; Johnson, Randall S

    2018-04-03

    Animals require an immediate response to oxygen availability to allow rapid shifts between oxidative and glycolytic metabolism. These metabolic shifts are highly regulated by the HIF transcription factor. The factor inhibiting HIF (FIH) is an asparaginyl hydroxylase that controls HIF transcriptional activity in an oxygen-dependent manner. We show here that FIH loss increases oxidative metabolism, while also increasing glycolytic capacity, and that this gives rise to an increase in oxygen consumption. We further show that the loss of FIH acts to accelerate the cellular metabolic response to hypoxia. Skeletal muscle expresses 50-fold higher levels of FIH than other tissues: we analyzed skeletal muscle FIH mutants and found a decreased metabolic efficiency, correlated with an increased oxidative rate and an increased rate of hypoxic response. We find that FIH, through its regulation of oxidation, acts in concert with the PHD/vHL pathway to accelerate HIF-mediated metabolic responses to hypoxia. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  10. Inhibition of the H3K9 methyltransferase G9A attenuates oncogenicity and activates the hypoxia signaling pathway.

    Jolene Caifeng Ho

    Full Text Available Epigenetic mechanisms play important roles in the regulation of tumorigenesis, and hypoxia-induced epigenetic changes may be critical for the adaptation of cancer cells to the hypoxic microenvironment of solid tumors. Previously, we showed that loss-of-function of the hypoxia-regulated H3K9 methyltransferase G9A attenuates tumor growth. However, the mechanisms by which blockade of G9A leads to a tumor suppressive effect remain poorly understood. We show that G9A is highly expressed in breast cancer and is associated with poor patient prognosis, where it may function as a potent oncogenic driver. In agreement with this, G9A inhibition by the small molecule inhibitor, BIX-01294, leads to increased cell death and impaired cell migration, cell cycle and anchorage-independent growth. Interestingly, whole transcriptome analysis revealed that genes involved in diverse cancer cell functions become hypoxia-responsive upon G9A inhibition. This was accompanied by the upregulation of the hypoxia inducible factors HIF1α and HIF2α during BIX-01294 treatment even in normoxia that may facilitate the tumor suppressive effects of BIX-01294. HIF inhibition was able to reverse some of the transcriptional changes induced by BIX-01294 in hypoxia, indicating that the HIFs may be important drivers of these derepressed target genes. Therefore, we show that G9A is a key mediator of oncogenic processes in breast cancer cells and G9A inhibition by BIX-01294 can successfully attenuate oncogenicity even in hypoxia.

  11. Neutralizing S1P inhibits intratumoral hypoxia, induces vascular remodelling and sensitizes to chemotherapy in prostate cancer

    Ader, Isabelle; Golzio, Muriel; Andrieu, Guillaume; Zalvidea, Santiago; Richard, Sylvain; Sabbadini, Roger A.; Malavaud, Bernard; Cuvillier, Olivier

    2015-01-01

    Hypoxia promotes neovascularization, increased tumor growth, and therapeutic resistance. The transcription factor, hypoxia-inducible factor 1α (HIF-1α), has been reported as the master driver of adaptation to hypoxia. We previously identified the sphingosine kinase 1/sphingosine 1-phosphate (SphK1/S1P) pathway as a new modulator of HIF-1α under hypoxia. Taking advantage of a monoclonal antibody neutralizing extracellular S1P (sphingomab), we report that inhibition of S1P extracellular signaling blocks HIF-1α accumulation and activity in several cancer cell models exposed to hypoxia. In an orthotopic xenograft model of prostate cancer, we show that sphingomab reduces hypoxia and modifies vessel architecture within 5 days of treatment, leading to increased intratumoral blood perfusion. Supporting the notion that a transient vascular normalization of tumor vessels is the mechanism by which sphingomab exerts its effects, we demonstrate that administration of the antibody for 5 days before chemotherapy is more effective at local tumor control and metastatic dissemination than any other treatment scheduling. These findings validate sphingomab as a potential new normalization agent that could contribute to successful sensitization of hypoxic tumors to chemotherapy. PMID:25915662

  12. Isthmin is a novel secreted angiogenesis inhibitor that inhibits tumour growth in mice

    Xiang, Wei; Ke, Zhiyuan; Zhang, Yong; Ho-Yuet Cheng, Grace; Irwan, Ishak Darryl; Sulochana, K N; Potturi, Padma; Wang, Zhengyuan; Yang, He; Wang, Jingyu; Zhuo, Lang; Kini, R Manjunatha; Ge, Ruowen

    2011-01-01

    Abstract Anti-angiogenesis represents a promising therapeutic strategy for the treatment of various malignancies. Isthmin (ISM) is a gene highly expressed in the isthmus of the midbrain–hindbrain organizer in Xenopus with no known functions. It encodes a secreted 60 kD protein containing a thrombospondin type 1 repeat domain in the central region and an adhesion-associated domain in MUC4 and other proteins (AMOP) domain at the C-terminal. In this work, we demonstrate that ISM is a novel angiogenesis inhibitor. Recombinant mouse ISM inhibited endothelial cell (EC) capillary network formation on Matrigel through its C-terminal AMOP domain. It also suppressed vascular endothelial growth factor (VEGF)-basic fibroblast growth factor (bFGF) induced in vivo angiogenesis in mouse. It mitigated VEGF-stimulated EC proliferation without affecting EC migration. Furthermore, ISM induced EC apoptosis in the presence of VEGF through a caspase-dependent pathway. ISM binds to αvβ5 integrin on EC surface and supports EC adhesion. Overexpression of ISM significantly suppressed mouse B16 melanoma tumour growth through inhibition of tumour angiogenesis without affecting tumour cell proliferation. Knockdown of isthmin in zebrafish embryos using morpholino antisense oligonucleotides led to disorganized intersegmen-tal vessels in the trunk. Our results demonstrate that ISM is a novel endogenous angiogenesis inhibitor with functions likely in physiological as well as pathological angiogenesis. PMID:19874420

  13. Isthmin is a novel secreted angiogenesis inhibitor that inhibits tumour growth in mice.

    Xiang, Wei; Ke, Zhiyuan; Zhang, Yong; Cheng, Grace Ho-Yuet; Irwan, Ishak Darryl; Sulochana, K N; Potturi, Padma; Wang, Zhengyuan; Yang, He; Wang, Jingyu; Zhuo, Lang; Kini, R Manjunatha; Ge, Ruowen

    2011-02-01

    Anti-angiogenesis represents a promising therapeutic strategy for the treatment of various malignancies. Isthmin (ISM) is a gene highly expressed in the isthmus of the midbrain-hindbrain organizer in Xenopus with no known functions. It encodes a secreted 60 kD protein containing a thrombospondin type 1 repeat domain in the central region and an adhesion-associated domain in MUC4 and other proteins (AMOP) domain at the C-terminal. In this work, we demonstrate that ISM is a novel angiogenesis inhibitor. Recombinant mouse ISM inhibited endothelial cell (EC) capillary network formation on Matrigel through its C-terminal AMOP domain. It also suppressed vascular endothelial growth factor (VEGF)-basic fibroblast growth factor (bFGF) induced in vivo angiogenesis in mouse. It mitigated VEGF-stimulated EC proliferation without affecting EC migration. Furthermore, ISM induced EC apoptosis in the presence of VEGF through a caspase-dependent pathway. ISM binds to αvβ(5) integrin on EC surface and supports EC adhesion. Overexpression of ISM significantly suppressed mouse B16 melanoma tumour growth through inhibition of tumour angiogenesis without affecting tumour cell proliferation. Knockdown of isthmin in zebrafish embryos using morpholino antisense oligonucleotides led to disorganized intersegmental vessels in the trunk. Our results demonstrate that ISM is a novel endogenous angiogenesis inhibitor with functions likely in physiological as well as pathological angiogenesis. © 2011 The Authors Journal of Cellular and Molecular Medicine © 2011 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.

  14. Inhibition of hypoxia inducible factor 1 and topoisomerase with acriflavine sensitizes perihilar cholangiocarcinomas to photodynamic therapy.

    Weijer, Ruud; Broekgaarden, Mans; Krekorian, Massis; Alles, Lindy K; van Wijk, Albert C; Mackaaij, Claire; Verheij, Joanne; van der Wal, Allard C; van Gulik, Thomas M; Storm, Gert; Heger, Michal

    2016-01-19

    Photodynamic therapy (PDT) induces tumor cell death by oxidative stress and hypoxia but also survival signaling through activation of hypoxia-inducible factor 1 (HIF-1). Since perihilar cholangiocarcinomas are relatively recalcitrant to PDT, the aims were to (1) determine the expression levels of HIF-1-associated proteins in human perihilar cholangiocarcinomas, (2) investigate the role of HIF-1 in PDT-treated human perihilar cholangiocarcinoma cells, and (3) determine whether HIF-1 inhibition reduces survival signaling and enhances PDT efficacy. Increased expression of VEGF, CD105, CD31/Ki-67, and GLUT-1 was confirmed in human perihilar cholangiocarcinomas. PDT with liposome-delivered zinc phthalocyanine caused HIF-1α stabilization in SK-ChA-1 cells and increased transcription of HIF-1α downstream genes. Acriflavine was taken up by SK-ChA-1 cells and translocated to the nucleus under hypoxic conditions. Importantly, pretreatment of SK-ChA-1 cells with acriflavine enhanced PDT efficacy via inhibition of HIF-1 and topoisomerases I and II. The expression of VEGF, CD105, CD31/Ki-67, and GLUT-1 was determined by immunohistochemistry in human perihilar cholangiocarcinomas. In addition, the response of human perihilar cholangiocarcinoma (SK-ChA-1) cells to PDT with liposome-delivered zinc phthalocyanine was investigated under both normoxic and hypoxic conditions. Acriflavine, a HIF-1α/HIF-1β dimerization inhibitor and a potential dual topoisomerase I/II inhibitor, was evaluated for its adjuvant effect on PDT efficacy. HIF-1, which is activated in human hilar cholangiocarcinomas, contributes to tumor cell survival following PDT in vitro. Combining PDT with acriflavine pretreatment improves PDT efficacy in cultured cells and therefore warrants further preclinical validation for therapy-recalcitrant perihilar cholangiocarcinomas.

  15. Hypoxia-Inducible Factor Pathway Inhibition Resolves Tumor Hypoxia and Improves Local Tumor Control After Single-Dose Irradiation

    Helbig, Linda; Koi, Lydia; Brüchner, Kerstin; Gurtner, Kristin; Hess-Stumpp, Holger; Unterschemmann, Kerstin; Pruschy, Martin

    2014-01-01

    Purpose: To study the effects of BAY-84-7296, a novel orally bioavailable inhibitor of mitochondrial complex I and hypoxia-inducible factor 1 (HIF-1) activity, on hypoxia, microenvironment, and radiation response of tumors. Methods and Materials: UT-SCC-5 and UT-SCC-14 human squamous cell carcinomas were transplanted subcutaneously in nude mice. When tumors reached 4 mm in diameter BAY-84-7296 (Bayer Pharma AG) or carrier was daily administered to the animals. At 7 mm tumors were either excised for Western blot and immunohistologic investigations or were irradiated with single doses. After irradiation animals were randomized to receive BAY-84-7296 maintenance or carrier. Local tumor control was evaluated 150 days after irradiation, and the dose to control 50% of tumors (TCD 50 ) was calculated. Results: BAY-84-7296 decreased nuclear HIF-1α expression. Daily administration of inhibitor for approximately 2 weeks resulted in a marked decrease of pimonidazole hypoxic fraction in UT-SCC-5 (0.5% vs 21%, P 50 , with an enhancement ratio of 1.37 (95% confidence interval [CI] 1.13-1.72) in UT-SCC-5 and of 1.55 (95% CI 1.26-1.94) in UT-SCC-14. BAY-84-7296 maintenance after irradiation did not further decrease TCD 50 . Conclusions: BAY-84-7296 resulted in a marked decrease in tumor hypoxia and substantially reduced radioresistance of tumor cells with the capacity to cause a local recurrence after irradiation. The data suggest that reduction of cellular hypoxia tolerance by BAY-84-7296 may represent the primary biological mechanism underlying the observed enhancement of radiation response. Whether this mechanism contributes to the improved outcome of fractionated chemoradiation therapy warrants further investigation

  16. HPV status, cancer stem cell marker expression, hypoxia gene signatures and tumour volume identify good prognosis subgroups in patients with HNSCC after primary radiochemotherapy: A multicentre retrospective study of the German Cancer Consortium Radiation Oncology Group (DKTK-ROG)

    Linge, Annett; Lohaus, Fabian; Löck, Steffen

    2016-01-01

    OBJECTIVE: To investigate the impact of the tumour volume, HPV status, cancer stem cell (CSC) marker expression and hypoxia gene signatures, as potential markers of radiobiological mechanisms of radioresistance, in a contemporary cohort of patients with locally advanced head and neck squamous cell...

  17. 3-Bromopyruvate reverses hypoxia-induced pulmonary arterial hypertension through inhibiting glycolysis: In vitro and in vivo studies.

    Chen, Fangzheng; Wang, Heng; Lai, Jiadan; Cai, Shujing; Yuan, Linbo

    2018-05-04

    Pulmonary arterial smooth muscle cell (PASMC) proliferation is vital to pulmonary vascular remodeling in pulmonary arterial hypertension (PAH) pathogenesis, and inhibiting PASMC metabolism could serve as a new possible therapy to reverse the process. 3-Bromopyruvate (3-BrPA) is an effective glycolysis inhibitor with its effect in PAH remains unclear. Our study aims to assess the therapeutic effect of 3-BrPA in PAH rats and investigate the possible mechanism of 3-BrPA in PASMC proliferation and apoptosis. 27 healthy SD rats were grouped and treated with hypoxia/normoxia and administration of 3-BrPA/physiological saline. Mean pulmonary artery pressure (mPAP) and cardiac output (CO) were measured and pulmonary vascular resistance (PVR) was calculated. Right ventricular hypertrophy index (RVHI) was calculated to evaluate the right ventricular hypertrophy degree. The percentage of medial wall area (WA%) and medial wall thickness (WT%) were measured by image analysis. PASMCs groups received hypoxia/normoxia treatments and 3-BrPA/physiological saline. PASMC proliferation and migration were respectively detected by CCK-8 and cell wound scratch assay. Hexokinase II (HK-2) expression and lactate level were respectively measured by Western Blotting and lactate test kit to detect glycolysis. mPAP, PVR, PVHI, WA% and WT% in rats increased after the hypoxia treatment, but were lower compared to rats received 3-BrPA in hypoxia environment. HK-2 expression, lactate concentration, OD value and scratch areas in PASMCs increased after the hypoxia treatment, but were decreased after the administration of 3-BrPA. 3-BrPA can inhibit PASMC proliferation and migration by inhibiting glycolysis, and is effective in reversing the vascular remodeling in hypoxia-induced PAH rats. Copyright © 2017. Published by Elsevier B.V.

  18. The stabilization of hypoxia inducible factor modulates differentiation status and inhibits the proliferation of mouse embryonic stem cells.

    Binó, Lucia; Kučera, Jan; Štefková, Kateřina; Švihálková Šindlerová, Lenka; Lánová, Martina; Kudová, Jana; Kubala, Lukáš; Pacherník, Jiří

    2016-01-25

    Hypoxic conditions are suggested to affect the differentiation status of stem cells (SC), including embryonic stem cells (ESC). Hypoxia inducible factor (HIF) is one of the main intracellular molecules responsible for the cellular response to hypoxia. Hypoxia stabilizes HIF by inhibiting the activity of HIF prolyl-hydroxylases (PHD), which are responsible for targeting HIF-alpha subunits for proteosomal degradation. To address the impact of HIF stabilization on the maintenance of the stemness signature of mouse ESC (mESC), we tested the influence of the inhibition of PHDs and hypoxia (1% O2 and 5% O2) on spontaneous ESC differentiation triggered by leukemia inhibitory factor withdrawal for 24 and 48 h. The widely used panhydroxylase inhibitor dimethyloxaloylglycine (DMOG) and PHD inhibitor JNJ-42041935 (JNJ) with suggested higher specificity towards PHDs were employed. Both inhibitors and both levels of hypoxia significantly increased HIF-1alpha and HIF-2alpha protein levels and HIF transcriptional activity in spontaneously differentiating mESC. This was accompanied by significant downregulation of cell proliferation manifested by the complete inhibition of DNA synthesis and partial arrest in the S phase after 48 h. Further, HIF stabilization enhanced downregulation of the expressions of some pluripotency markers (OCT-4, NANOG, ZFP-42, TNAP) in spontaneously differentiating mESC. However, at the same time, there was also a significant decrease in the expression of some genes selected as markers of cell differentiation (e.g. SOX1, BRACH T, ELF5). In conclusion, the short term stabilization of HIF mediated by the PHD inhibitors JNJ and DMOG and hypoxia did not prevent the spontaneous loss of pluripotency markers in mESC. However, it significantly downregulated the proliferation of these cells. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  19. N-n-butyl haloperidol iodide protects cardiomyocytes against hypoxia/reoxygenation injury by inhibiting autophagy.

    Wang, Bin; Zhong, Shuping; Zheng, Fuchun; Zhang, Yanmei; Gao, Fenfei; Chen, Yicun; Lu, Binger; Xu, Han; Shi, Ganggang

    2015-09-22

    N-n-butyl haloperidol iodide (F2), a novel compound derived from haloperidol, protects against the damaging effects of ischemia/reperfusion (I/R) injury in vitro and in vivo. In this study, we hypothesized the myocardial protection of F2 on cardiomyocyte hypoxia/reoxygenation (H/R) injury is mediated by inhibiting autophagy in H9c2 cells. The degree of autophagy by treatment with F2 exposed to H/R in H9c2 cell was characterized by monodansylcadaverine, transmission electron microscopy, and expression of autophagy marker protein LC3. Our results indicated that treatment with F2 inhibited autophagy in H9c2 cells exposed to H/R. 3-methyladenine, an inhibitor of autophagy, suppressed H/R-induced autophagy, and decreased apoptosis, whereas rapamycin, a classical autophagy sensitizer, increased autophagy and apoptosis. Mechanistically, macrophage migration inhibitory factor (MIF) was inhibited by F2 treatment after H/R. Accordingly, small interfering RNA (siRNA)-mediated MIF knockdown decreased H/R-induced autophagy. In summary, F2 protects cardiomyocytes during H/R injury through suppressing autophagy activation. Our results provide a new mechanistic insight into a functional role of F2 against H/R-induced cardiomyocyte injury and death.

  20. Angiogenesis and expression of vascular endothelial growth factor, tumour necrosis factor-α and hypoxia inducible factor-1α in canine renal cell carcinoma.

    Yhee, J Y; Yu, C H; Kim, J H; Im, K S; Kim, N H; Brodersen, B W; Doster, A R; Sur, J-H

    2012-01-01

    The aim of the present study was to determine the distribution and characteristics of microvessels in various histological types of canine renal cell carcinoma (RCC). The study compared microvessel density (MVD) and distribution of blood vessels according to histological type and evaluated the presence of angiogenesis-related proteins. Nine archival samples of canine RCC were studied. MVD was calculated as the mean number of blood vessels per mm(2). The diameter of blood vessels was calculated by determining either the length of the long axis of blood vessels (diameter(max)) or the mean distance from the centre of each blood vessel to the tunica adventia (diameter(mean)). A significant difference in MVD was evident between RCCs and normal kidneys (46.6 ± 28.0 versus 8.4 ± 2.2 microvessels/mm(2)). Diameter(max) in canine RCCs (34.1 ± 14.7 μm) was also significantly different from normal canine kidney (23.2 ± 3.4 μm). Vascular endothelial growth factor (VEGF) was expressed by tumour cells and vascular endothelial cells and tumour necrosis factor (TNF)-α expression was observed in vascular endothelial cells in both neoplastic and normal kidney. Although VEGF is involved in angiogenesis and correlates with tumour stage of development, no correlation was found between VEGF expression and MVD. Tumour-associated macrophages expressing TNF-α and hypoxia inducible factor 1α were identified in peritumoural tissue and may play an important role in angiogenesis. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Hypoxia and loss of PHD2 inactivate stromal fibroblasts to decrease tumour stiffness and metastasis

    Madsen, Chris D; Pedersen, Jesper Thorhauge; Venning, Freja A

    2015-01-01

    , which can be prevented by simultaneous depletion of HIF-1α. Treatment with the PHD inhibitor DMOG in an orthotopic breast cancer model significantly decreases spontaneous metastases to the lungs and liver, associated with decreased tumour stiffness and fibroblast activation. PHD2 depletion in CAFs co......-injected with tumour cells similarly prevents CAF-induced metastasis to lungs and liver. Our data argue that reversion of CAFs towards a less active state is possible and could have important clinical implications....

  2. Andrographolide inhibits hypoxia-induced hypoxia-inducible factor 1α and endothelin 1 expression through the heme oxygenase 1/CO/cGMP/MKP-5 pathways in EA.hy926 cells.

    Lin, Hung-Chih; Su, Shih-Li; Lin, Wan-Chun; Lin, Ai-Hsuan; Yang, Ya-Chen; Lii, Chong-Kuei; Chen, Haw-Wen

    2018-03-01

    Andrographolide is a potent anti-inflammatory agent found in Andrographis paniculata. Endothelin 1 (ET-1) is an endothelium-derived vasoconstrictor with pro-inflammatory properties secreted in response to hypoxia. Mitogen-activated protein kinase phosphatase 5 (MKP-5) is a dual-specificity phosphatase that dephosphorylates threonine and tyrosine residues of MAPKs. We showed previously that hypoxia-induced HIF-1α expression and ET-1 secretion are dependent on p38 MAPK in EA.hy926 cells. Here, we investigate what role MKP-5 plays in andrographolide's inhibition of hypoxia-induced expression of HIF-1α and ET-1. Hypoxic conditions were created using the hypoxia-mimetic agent CoCl 2 . Andrographolide enhanced HO-1 and MKP-5 expression and cellular cGMP content in addition to inhibiting hypoxia-induced ROS generation. Concomitantly, the HO-1 byproduct CO and the cGMP analogue 8-bromoguanosine 3',5'-cyclic monophosphate (8-Br-cGMP) increased MKP-5 expression, and pretreatment with CO and 8-Br-cGMP inhibited hypoxia-induced HIF-1α and ET-1 expression. Transfection of HO-1 siRNA or pretreatment with the HO-1 inhibitor ZnPP-9 or 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, a specific inhibitor of soluble guanylate cyclase, reduced andrographolide-induced MKP-5 expression. Moreover, silencing MKP-5 or treatment with the phosphatase inhibitor vanadate abrogated andrographolide's suppressing hypoxia-induced p38 MAPK activation and HIF-1α expression. The inhibition of hypoxia-induced HIF-1α and ET-1 expression by andrographolide is likely associated with HO-1/CO/cGMP/MKP-5 pathways, which is involved in inhibiting hypoxia-induced p38 MAPK activation. © 2017 Wiley Periodicals, Inc.

  3. Andrographolide inhibits hypoxia-inducible factor-1 through phosphatidylinositol 3-kinase/AKT pathway and suppresses breast cancer growth

    Li J

    2015-02-01

    Full Text Available Jie Li,1 Chao Zhang,1 Hongchuan Jiang,1 Jiao Cheng21Department of General Surgery, 2Department of Gynaecology and Obstetrics, Beijing Chao-Yang Hospital, Beijing, People’s Republic of ChinaAbstract: Hypoxia-inducible factor-1 (HIF-1 is a master regulator of the transcriptional response to hypoxia. HIF-1α is one of the most compelling anticancer targets. Andrographolide (Andro was newly identified to inhibit HIF-1 in T47D cells (a half maximal effective concentration [EC50] of 1.03×10-7 mol/L, by a dual-luciferase reporter assay. It suppressed HIF-1α protein and gene accumulation, which was dependent on the inhibition of upstream phosphatidylinositol 3-kinase (PI3K/AKT pathway. It also abrogated the expression of HIF-1 target vascular endothelial growth factor (VEGF gene and protein. Further, Andro inhibited T47D and MDA-MB-231 cell proliferation and colony formation. In addition, it exhibited significant in vivo efficacy and antitumor potential against the MDA-MB-231 xenograft in nude mice. In conclusion, these results highlighted the potential effects of Andro, which inhibits HIF-1, and hence may be developed as an antitumor agent for breast cancer therapy in future.Keywords: Andrographolide (Andro, HIF-1α, inhibit, breast cancer, hypoxia, PI3k/AKT/mTOR pathway

  4. Tumour control in ion beam radiotherapy with different ions in the presence of hypoxia: an oxygen enhancement ratio model based on the microdosimetric kinetic model

    Strigari, L.; Torriani, F.; Manganaro, L.; Inaniwa, T.; Dalmasso, F.; Cirio, R.; Attili, A.

    2018-03-01

    Few attempts have been made to include the oxygen enhancement ratio (OER) in treatment planning for ion beam therapy, and systematic studies to evaluate the impact of hypoxia in treatment with the beam of different ion species are sorely needed. The radiobiological models used to quantify the OER in such studies are mainly based on the dose-averaged LET estimates, and do not explicitly distinguish between the ion species and fractionation schemes. In this study, a new type of OER modelling, based on the microdosimetric kinetic model, taking into account the specificity of the different ions, LET spectra, tissues and fractionation schemes, has been developed. The model has been benchmarked with published in vitro data, HSG, V79 and CHO cells in aerobic and hypoxic conditions, for different ion irradiation. The model has been included in the simulation of treatments for a clinical case (brain tumour) using proton, lithium, helium, carbon and oxygen ion beams. A study of the tumour control probability (TCP) as a function of oxygen partial pressure, dose per fraction and primary ion type has been performed. The modelled OER depends on both the LET and ion type, also showing a decrease for an increased dose per fraction with a slope that depends on the LET and ion type, in good agreement with the experimental data. In the investigated clinical case, a significant increase in TCP has been found upon increasing the ion charge. Higher OER variations as a function of dose per fraction have also been found for low-LET ions (up to 15% varying from 2 to 8 Gy(RBE) for protons). This model could be exploited in the identification of treatment condition optimality in the presence of hypoxia, including fractionation and primary particle selection.

  5. Hypoxia-Inducible Factor Pathway Inhibition Resolves Tumor Hypoxia and Improves Local Tumor Control After Single-Dose Irradiation

    Helbig, Linda [OncoRay–National Center for Radiation Research in Oncology, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Dresden (Germany); Department of Radiation Oncology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden (Germany); Koi, Lydia [OncoRay–National Center for Radiation Research in Oncology, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Dresden (Germany); Department of Radiation Oncology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden (Germany); Deutsches Konsortium für Translationale Krebsforschung, Site Dresden, Dresden (Germany); Brüchner, Kerstin [Department of Radiation Oncology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden (Germany); Institute of Radiooncology Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Gurtner, Kristin [Department of Radiation Oncology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden (Germany); Hess-Stumpp, Holger; Unterschemmann, Kerstin [Global Drug Discovery, Bayer Pharma, Berlin (Germany); Pruschy, Martin [Radiation Oncology, University of Zurich, Zurich (Switzerland); and others

    2014-01-01

    Purpose: To study the effects of BAY-84-7296, a novel orally bioavailable inhibitor of mitochondrial complex I and hypoxia-inducible factor 1 (HIF-1) activity, on hypoxia, microenvironment, and radiation response of tumors. Methods and Materials: UT-SCC-5 and UT-SCC-14 human squamous cell carcinomas were transplanted subcutaneously in nude mice. When tumors reached 4 mm in diameter BAY-84-7296 (Bayer Pharma AG) or carrier was daily administered to the animals. At 7 mm tumors were either excised for Western blot and immunohistologic investigations or were irradiated with single doses. After irradiation animals were randomized to receive BAY-84-7296 maintenance or carrier. Local tumor control was evaluated 150 days after irradiation, and the dose to control 50% of tumors (TCD{sub 50}) was calculated. Results: BAY-84-7296 decreased nuclear HIF-1α expression. Daily administration of inhibitor for approximately 2 weeks resulted in a marked decrease of pimonidazole hypoxic fraction in UT-SCC-5 (0.5% vs 21%, P<.0001) and in UT-SCC-14 (0.3% vs 19%, P<.0001). This decrease was accompanied by a significant increase in fraction of perfused vessels in UT-SCC-14 but not in UT-SCC-5. Bromodeoxyuridine and Ki67 labeling indices were significantly reduced only in UT-SCC-5. No significant changes were observed in vascular area or necrosis. BAY-84-7296 before single-dose irradiation significantly decreased TCD{sub 50}, with an enhancement ratio of 1.37 (95% confidence interval [CI] 1.13-1.72) in UT-SCC-5 and of 1.55 (95% CI 1.26-1.94) in UT-SCC-14. BAY-84-7296 maintenance after irradiation did not further decrease TCD{sub 50}. Conclusions: BAY-84-7296 resulted in a marked decrease in tumor hypoxia and substantially reduced radioresistance of tumor cells with the capacity to cause a local recurrence after irradiation. The data suggest that reduction of cellular hypoxia tolerance by BAY-84-7296 may represent the primary biological mechanism underlying the observed enhancement of

  6. Anthrax lethal toxin inhibits translation of hypoxia-inducible factor 1α and causes decreased tolerance to hypoxic stress.

    Ouyang, Weiming; Torigoe, Chikako; Fang, Hui; Xie, Tao; Frucht, David M

    2014-02-14

    Hypoxia is considered to be a contributor to the pathology associated with administration of anthrax lethal toxin (LT). However, we report here that serum lactate levels in LT-treated mice are reduced, a finding inconsistent with the anaerobic metabolism expected to occur during hypoxia. Reduced lactate levels are also observed in the culture supernatants of LT-treated cells. LT inhibits the accumulation of hypoxia-inducible factor (HIF)-1α, a subunit of HIF-1, the master regulator directing cellular responses to hypoxia. The toxin has no effect on the transcription or protein turnover of HIF-1α, but instead it acts to inhibit HIF-1α translation. LT treatment diminishes phosphorylation of eIF4B, eIF4E, and rpS6, critical components of the intracellular machinery required for HIF-1α translation. Moreover, blockade of MKK1/2-ERK1/2, but not p38 or JNK signaling, lowers HIF-1α protein levels in both normoxic and hypoxic conditions, consistent with a role for MKK1 and MKK2 as the major targets of LT responsible for the inhibition of HIF-1α translation. The physiological importance of the LT-induced translation blockade is demonstrated by the finding that LT treatment decreases the survival of hepatocyte cell lines grown in hypoxic conditions, an effect that is overcome by preinduction of HIF-1α. Taken together, these data support a role for LT in dysregulating HIF-1α and thereby disrupting homeostatic responses to hypoxia, an environmental characteristic of certain tissues at baseline and/or during disseminated infection with Bacillus anthracis.

  7. On the surviving fraction in irradiated multicellular tumour spheroids: calculation of overall radiosensitivity parameters, influence of hypoxia and volume effects

    Horas, Jorge A; Olguin, Osvaldo R; Rizzotto, Marcos G

    2005-01-01

    We model the heterogeneous response to radiation of multicellular tumour spheroids assuming position- and volume-dependent radiosensitivity. We propose a method to calculate the overall radiosensitivity parameters to obtain the surviving fraction of tumours. A mathematical model of a spherical tumour with a hypoxic core and a viable rim which is a caricature of a real tumour is constructed. The model is embedded in a two-compartment linear-quadratic (LQ) model, assuming a mixed bivariated Gaussian distribution to attain the radiosensitivity parameters. Ergodicity, i.e., the equivalence between ensemble and volumetric averages is used to obtain the overall radiosensitivities for the two compartments. We obtain expressions for the overall radiosensitivity parameters resulting from the use of both a linear and a nonlinear dependence of the local radiosensitivity with position. The model's results are compared with experimental data of surviving fraction (SF) for multicellular spheroids of different sizes. We make one fit using only the smallest spheroid data and we are able to predict the SF for the larger spheroids. These predictions are acceptable particularly using bounded sensitivities. We conclude with the importance of taking into account the contribution of clonogenic hypoxic cells to radiosensitivity and with the convenience of using bounded local sensitivities to predict overall radiosensitivity parameters

  8. A bi-paratopic anti-EGFR nanobody efficiently inhibits solid tumour growth

    Roovers, Rob C.; Vosjan, Maria J.W.D.; Laeremans, Toon; el Khoulati, Rachid; de Bruin, Renée C.G.; Ferguson, Kathryn M.; Verkleij, Arie J.; van Dongen, Guus A.M.S.; van Bergen en Henegouwen, Paul M. P.

    2014-01-01

    The epidermal growth factor receptor (EGFR) has been shown to be a valid cancer target for antibody-based therapy. At present, several anti-EGFR monoclonal antibodies (mAbs) have been successfully used, among which cetuximab and matuzumab. X-ray crystallography data show that these antibodies bind to different epitopes on the ecto-domain of EGFR, providing a rationale for the combined use of these two antibody specificities. We have previously reported on the successful isolation of antagonistic anti-EGFR nanobodies. In the present study, we aimed to improve on these molecules by combining nanobodies with specificities similar to both cetuximab and matuzumab into a single bi-paratopic molecule. Carefully designed phage nanobody selections resulted in two sets of nanobodies that specifically blocked the binding of either matuzumab or of cetuximab to EGFR and that did not compete for each others binding. A combination of nanobodies from both epitope groups into the bi-paratopic nanobody CONAN-1 was shown to block EGFR activation more efficiently than monovalent or bivalent (monospecific) nanobodies. In addition, this bi-paratopic nanobody potently inhibited EGF-dependent cell proliferation. Importantly, in an in vivo model of athymic mice bearing A431 xenografts, CONAN-1 inhibited tumour outgrowth with an almost similar potency as the whole mAb cetuximab, despite the fact that CONAN-1 is devoid of an Fc portion that could mediate immune effector functions. Compared to therapy using bivalent, mono-specific nanobodies, CONAN-1 was clearly more potent in tumour growth inhibition. These results show that the rational design of bi-paratopic nanobody-based anti-cancer therapeutics may yield potent lead molecules for further development. PMID:21520037

  9. Gene expression profiling in equine polysaccharide storage myopathy revealed inflammation, glycogenesis inhibition, hypoxia and mitochondrial dysfunctions

    Benech Philippe

    2009-08-01

    Full Text Available Abstract Background Several cases of myopathies have been observed in the horse Norman Cob breed. Muscle histology examinations revealed that some families suffer from a polysaccharide storage myopathy (PSSM. It is assumed that a gene expression signature related to PSSM should be observed at the transcriptional level because the glycogen storage disease could also be linked to other dysfunctions in gene regulation. Thus, the functional genomic approach could be conducted in order to provide new knowledge about the metabolic disorders related to PSSM. We propose exploring the PSSM muscle fiber metabolic disorders by measuring gene expression in relationship with the histological phenotype. Results Genotypying analysis of GYS1 mutation revealed 2 homozygous (AA and 5 heterozygous (GA PSSM horses. In the PSSM muscles, histological data revealed PAS positive amylase resistant abnormal polysaccharides, inflammation, necrosis, and lipomatosis and active regeneration of fibers. Ultrastructural evaluation revealed a decrease of mitochondrial number and structural disorders. Extensive accumulation of an abnormal polysaccharide displaced and partially replaced mitochondria and myofibrils. The severity of the disease was higher in the two homozygous PSSM horses. Gene expression analysis revealed 129 genes significantly modulated (p Conclusion The main disorders observed in PSSM muscles could be related to mitochondrial dysfunctions, glycogenesis inhibition and the chronic hypoxia of the PSSM muscles.

  10. A RNA antagonist of hypoxia-inducible factor-1alpha, EZN-2968, inhibits tumor cell growth

    Greenberger, Lee M; Horak, Ivan D; Filpula, David

    2008-01-01

    Hypoxia-inducible factor-1 (HIF-1) is a transcription factor that plays a critical role in angiogenesis, survival, metastasis, drug resistance, and glucose metabolism. Elevated expression of the alpha-subunit of HIF-1 (HIF-1alpha), which occurs in response to hypoxia or activation of growth facto...

  11. Inhibition of hypoxia inducible factor 1 and topoisomerase with acriflavine sensitizes perihilar cholangiocarcinomas to photodynamic therapy

    Weijer, Ruud; Broekgaarden, Mans; Krekorian, Massis; Alles, Lindy K.; van Wijk, Albert C.; Mackaaij, Claire; Verheij, Joanne; van der Wal, Allard C.; van Gulik, Thomas M.; Storm, Gert; Heger, Michal

    2016-01-01

    Photodynamic therapy (PDT) induces tumor cell death by oxidative stress and hypoxia but also survival signaling through activation of hypoxia-inducible factor 1 (HIF-1). Since perihilar cholangiocarcinomas are relatively recalcitrant to PDT, the aims were to (1) determine the expression levels of

  12. Inhibition of hypoxia inducible factor 1 and topoisomerase with acriflavine sensitizes perihilar cholangiocarcinomas to photodynamic therapy

    Weijer, R.; Broekgaarden, M.; Krekorian, M.; Alles, L.K.; van Wijk, A.C; Mackaaij, C.; Verheij, J.; van der Wal, A.C.; van Gullik, T.M.; Storm, Gerrit; Heger, M.

    2016-01-01

    Background: Photodynamic therapy (PDT) induces tumor cell death by oxidative stress and hypoxia but also survival signaling through activation of hypoxia-inducible factor 1 (HIF-1). Since perihilar cholangiocarcinomas are relatively recalcitrant to PDT, the aims were to (1) determine the expression

  13. Inhibition of Siah2 ubiquitin ligase by vitamin K3 (menadione) attenuates hypoxia and MAPK signaling and blocks melanoma tumorigenesis.

    Shah, Meera; Stebbins, John L; Dewing, Antimone; Qi, Jianfei; Pellecchia, Maurizio; Ronai, Ze'ev A

    2009-12-01

    The E3 ubiquitin ligase Siah2 has been implicated in the regulation of the hypoxia response, as well as in the control of Ras, JNK/p38/NF-kappaB signaling pathways. Both Ras/mitogen-activated protein kinase (MAPK) and hypoxia pathways are important for melanoma development and progression, pointing to the possible use of Siah2 as target for treatment of this tumor type. In the present study, we have established a high-throughput electro-chemiluninescent-based assay in order to screen and identify inhibitors of Siah2 ubiquitin ligase activity. Of 1840 compounds screened, we identified and characterized menadione (MEN) as a specific inhibitor of Siah2 ligase activity. MEN attenuated Siah2 self-ubiquitination, and increased expression of its substrates PHD3 and Sprouty2, with concomitant decrease in levels of HIF-1alpha and pERK, the respective downstream effectors. MEN treatment no longer affected PHD3 or Sprouty2 in Siah-KO cells, pointing to its Siah-dependent effects. Further, MEN inhibition of Siah2 was not attenuated by free radical scavenger, suggesting it is ROS-independent. Significantly, growth of xenograft melanoma tumors was inhibited following the administration of MEN or its derivative. These findings reveal an efficient platform for the identification of Siah inhibitors while identifying and characterizing MEN as Siah inhibitor that attenuates hypoxia and MAPK signaling, and inhibits melanoma tumorigenesis.

  14. Inhibition of Siah2 ubiquitin ligase by vitamin K3 (menadione) attenuates hypoxia and MAPK signaling and blocks melanoma tumorigenesis

    Shah, Meera; Stebbins, John L.; Dewing, Antimone; Qi, Jianfei; Pellecchia, Maurizio; Ronai, Ze’ev A.

    2010-01-01

    Summary The E3 ubiquitin ligase Siah2 has been implicated in the regulation of the hypoxia response, as well as in the control of Ras, JNK/p38/NF-κB signaling pathways. Both Ras/mitogen-activated protein kinase (MAPK) and hypoxia pathways are important for melanoma development and progression, pointing to the possible use of Siah2 as target for treatment of this tumor type. In the present study, we have established a high-throughput electro-chemiluninescent-based assay in order to screen and identify inhibitors of Siah2 ubiquitin ligase activity. Of 1840 compounds screened, we identified and characterized menadione (MEN) as a specific inhibitor of Siah2 ligase activity. MEN attenuated Siah2 self-ubiquitination, and increased expression of its substrates PHD3 and Sprouty2, with concomitant decrease in levels of HIF-1α and pERK, the respective downstream effectors. MEN treatment no longer affected PHD3 or Sprouty2 in Siah-KO cells, pointing to its Siah-dependent effects. Further, MEN inhibition of Siah2 was not attenuated by free radical scavenger, suggesting it is ROS-independent. Significantly, growth of xenograft melanoma tumors was inhibited following the administration of MEN or its derivative. These findings reveal an efficient platform for the identification of Siah inhibitors while identifying and characterizing MEN as Siah inhibitor that attenuates hypoxia and MAPK signaling, and inhibits melanoma tumorigenesis. PMID:19712206

  15. Silver nanoparticles inhibit the function of hypoxia-inducible factor-1 and target genes: insight into the cytotoxicity and antiangiogenesis.

    Yang, Tieshan; Yao, Qian; Cao, Fei; Liu, Qianqian; Liu, Binlei; Wang, Xiu-Hong

    Hypoxia-inducible factor-1 (HIF-1) is a transcription factor that is activated upon exposure to hypoxic stress. It modulates a number of cellular responses including proliferation, apoptosis, angiogenesis, and metabolism by activating a panel of target genes in response to hypoxia. The HIF-1 level is often upregulated in the hypoxic microenvironment of solid tumors, which contributes to cancer treatment failure. Here we report that silver nanoparticles (AgNPs), which are widely used as an antimicrobial agent, are an effective inhibitor of HIF-1. AgNPs inhibited the activation of a HIF-dependent reporter construct after the cells were exposed to hypoxic conditions or treated with cobalt chloride, a hypoxia mimetic agent. The AgNPs also interfered with the accumulation of HIF-1α protein and the induction of the endogenous HIF target genes, VEGF-A and GLUT1. Since both HIF-1 and vascular endothelial growth factor-A play an important role in angiogenesis, AgNPs also inhibited angiogenesis in vitro. Our data reveal a new mechanism of how AgNPs act on cellular function, that is, they disrupt HIF signaling pathway. This finding provides a novel insight into how AgNPs can inhibit cancer cell growth and angiogenesis.

  16. Silver nanoparticles inhibit the function of hypoxia-inducible factor-1 and target genes: insight into the cytotoxicity and antiangiogenesis

    Yang T

    2016-12-01

    Full Text Available Tieshan Yang,1 Qian Yao,1 Fei Cao,1 Qianqian Liu,1 Binlei Liu,2 Xiu-Hong Wang1 1Laboratory for Biomedical Photonics, Institute of Laser Engineering, Beijing University of Technology, 2Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People’s Republic of China Abstract: Hypoxia-inducible factor-1 (HIF-1 is a transcription factor that is activated upon exposure to hypoxic stress. It modulates a number of cellular responses including proliferation, apoptosis, angiogenesis, and metabolism by activating a panel of target genes in response to hypoxia. The HIF-1 level is often upregulated in the hypoxic microenvironment of solid tumors, which contributes to cancer treatment failure. Here we report that silver nanoparticles (AgNPs, which are widely used as an antimicrobial agent, are an effective inhibitor of HIF-1. AgNPs inhibited the activation of a HIF-dependent reporter construct after the cells were exposed to hypoxic conditions or treated with cobalt chloride, a hypoxia mimetic agent. The AgNPs also interfered with the accumulation of HIF-1α protein and the induction of the endogenous HIF target genes, VEGF-A and GLUT1. Since both HIF-1 and vascular endothelial growth factor-A play an important role in angiogenesis, AgNPs also inhibited angiogenesis in vitro. Our data reveal a new mechanism of how AgNPs act on cellular function, that is, they disrupt HIF signaling pathway. This finding provides a novel insight into how AgNPs can inhibit cancer cell growth and angiogenesis. Keywords: silver nanoparticles (AgNPs, hypoxia-inducible factor, transcriptional activity, vascular endothelial growth factor-A, angiogenesis

  17. Diverse effects of combined radiotherapy and EGFR inhibition with antibodies or TK inhibitors on local tumour control and correlation with EGFR gene expression

    Gurtner, Kristin; Deuse, Yvonne; Buetof, Rebecca; Schaal, Katja; Eicheler, Wolfgang; Oertel, Reinhard; Grenman, Reidar; Thames, Howard; Yaromina, Ala; Baumann, Michael; Krause, Mechthild

    2011-01-01

    Purpose: To compare functional effects of combined irradiation and EGFR inhibition in different HNSCC tumour models in vivo with the results of molecular evaluations, aiming to set a basis for the development of potential biomarkers for local tumour control. Material and methods: In five HNSCC tumour models, all wild-type for EGFR and KRAS, the effect of radiotherapy alone (30 fractions/6 weeks) and with simultaneous cetuximab or erlotinib treatment on local tumour control were evaluated and compared with molecular data on western blot, immunohistochemistry and fluorescence-in situ-hybridisation (FISH). Results: Erlotinib and cetuximab alone significantly prolonged tumour growth time in 4/5 tumour models. Combined irradiation and cetuximab treatment significantly improved local tumour control in 3/5 tumour models, whereas erlotinib did not alter local tumour control in any of the tumour models. The amount of the cetuximab-effect on local tumour control significantly correlated with the EGFR/CEP-7 ratios obtained by FISH. Conclusion: Both drugs prolonged growth time in most tumour models, but only application of cetuximab during irradiation significantly improved local tumour control in 3/5 tumour models. The significant correlation of this curative effect with the genetic EGFR expression measured by FISH will be further validated in preclinical and clinical studies.

  18. Egg Yolk Phospholipids Enriched with 1-O-Octadecyl-2-Oleoyl-sn-Glycero-3-Phospho-(N-Palmitoyl) Ethanolamine Inhibit Development of Experimentally Induced Tumours

    Karafiát, Vít; Veselý, Pavel; Dvořák, Michal

    2014-01-01

    Roč. 60, č. 5 (2014), s. 220-227 ISSN 0015-5500 Institutional support: RVO:68378050 Keywords : hen egg phospholipids * phospholipid derivative NAEPE * inhibition of tumour cells * inhibition of liver * lung * kidney tumours * chicken model Subject RIV: CE - Biochemistry Impact factor: 1.000, year: 2014

  19. Hypoxia-mimetic agents inhibit proliferation and alter the morphology of human umbilical cord-derived mesenchymal stem cells

    Zeng Hui-Lan

    2011-08-01

    Full Text Available Abstract Background The therapeutic efficacy of human mesenchymal stem cells (hMSCs for the treatment of hypoxic-ischemic diseases is closely related to level of hypoxia in the damaged tissues. To elucidate the potential therapeutic applications and limitations of hMSCs derived from human umbilical cords, the effects of hypoxia on the morphology and proliferation of hMSCs were analyzed. Results After treatment with DFO and CoCl2, hMSCs were elongated, and adjacent cells were no longer in close contact. In addition, vacuole-like structures were observed within the cytoplasm; the rough endoplasmic reticulum expanded, and expanded ridges were observed in mitochondria. In addition, DFO and CoCl2 treatments for 48 h significantly inhibited hMSCs proliferation in a concentration-dependent manner (P Conclusions The hypoxia-mimetic agents, DFO and CoCl2, alter umbilical cord-derived hMSCs morphology and inhibit their proliferation through influencing the cell cycle.

  20. Kinetic Investigations of the Role of Factor Inhibiting Hypoxia-inducible Factor (FIH) as an Oxygen Sensor.

    Tarhonskaya, Hanna; Hardy, Adam P; Howe, Emily A; Loik, Nikita D; Kramer, Holger B; McCullagh, James S O; Schofield, Christopher J; Flashman, Emily

    2015-08-07

    The hypoxia-inducible factor (HIF) hydroxylases regulate hypoxia sensing in animals. In humans, they comprise three prolyl hydroxylases (PHD1-3 or EGLN1-3) and factor inhibiting HIF (FIH). FIH is an asparaginyl hydroxylase catalyzing post-translational modification of HIF-α, resulting in reduction of HIF-mediated transcription. Like the PHDs, FIH is proposed to have a hypoxia-sensing role in cells, enabling responses to changes in cellular O2 availability. PHD2, the most important human PHD isoform, is proposed to be biochemically/kinetically suited as a hypoxia sensor due to its relatively high sensitivity to changes in O2 concentration and slow reaction with O2. To ascertain whether these parameters are conserved among the HIF hydroxylases, we compared the reactions of FIH and PHD2 with O2. Consistent with previous reports, we found lower Km(app)(O2) values for FIH than for PHD2 with all HIF-derived substrates. Under pre-steady-state conditions, the O2-initiated FIH reaction is significantly faster than that of PHD2. We then investigated the kinetics with respect to O2 of the FIH reaction with ankyrin repeat domain (ARD) substrates. FIH has lower Km(app)(O2) values for the tested ARDs than HIF-α substrates, and pre-steady-state O2-initiated reactions were faster with ARDs than with HIF-α substrates. The results correlate with cellular studies showing that FIH is active at lower O2 concentrations than the PHDs and suggest that competition between HIF-α and ARDs for FIH is likely to be biologically relevant, particularly in hypoxic conditions. The overall results are consistent with the proposal that the kinetic properties of individual oxygenases reflect their biological capacity to act as hypoxia sensors. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  1. Automatic Quantification of Tumour Hypoxia From Multi-Modal Microscopy Images Using Weakly-Supervised Learning Methods.

    Carneiro, Gustavo; Peng, Tingying; Bayer, Christine; Navab, Nassir

    2017-07-01

    In recently published clinical trial results, hypoxia-modified therapies have shown to provide more positive outcomes to cancer patients, compared with standard cancer treatments. The development and validation of these hypoxia-modified therapies depend on an effective way of measuring tumor hypoxia, but a standardized measurement is currently unavailable in clinical practice. Different types of manual measurements have been proposed in clinical research, but in this paper we focus on a recently published approach that quantifies the number and proportion of hypoxic regions using high resolution (immuno-)fluorescence (IF) and hematoxylin and eosin (HE) stained images of a histological specimen of a tumor. We introduce new machine learning-based methodologies to automate this measurement, where the main challenge is the fact that the clinical annotations available for training the proposed methodologies consist of the total number of normoxic, chronically hypoxic, and acutely hypoxic regions without any indication of their location in the image. Therefore, this represents a weakly-supervised structured output classification problem, where training is based on a high-order loss function formed by the norm of the difference between the manual and estimated annotations mentioned above. We propose four methodologies to solve this problem: 1) a naive method that uses a majority classifier applied on the nodes of a fixed grid placed over the input images; 2) a baseline method based on a structured output learning formulation that relies on a fixed grid placed over the input images; 3) an extension to this baseline based on a latent structured output learning formulation that uses a graph that is flexible in terms of the amount and positions of nodes; and 4) a pixel-wise labeling based on a fully-convolutional neural network. Using a data set of 89 weakly annotated pairs of IF and HE images from eight tumors, we show that the quantitative results of methods (3) and (4

  2. Effects of Src Kinase Inhibition on Expression of Protein Tyrosine Phosphatase 1B after Brain Hypoxia in a Piglet Animal Model

    Dimitrios Angelis

    2017-01-01

    Full Text Available Background. Protein tyrosine phosphatases (PTPs in conjunction with protein tyrosine kinases (PTKs regulate cellular processes by posttranslational modifications of signal transduction proteins. PTP nonreceptor type 1B (PTP-1B is an enzyme of the PTP family. We have previously shown that hypoxia induces an increase in activation of a class of nonreceptor PTK, the Src kinases. In the present study, we investigated the changes that occur in the expression of PTP-1B in the cytosolic component of the brain of newborn piglets acutely after hypoxia as well as long term for up to 2 weeks. Methods. Newborn piglets were divided into groups: normoxia, hypoxia, hypoxia followed by 1 day and 15 days in FiO2 0.21, and hypoxia pretreated with Src kinase inhibitor PP2, prior to hypoxia followed by 1 day and 15 days. Hypoxia was achieved by providing 7% FiO2 for 1 hour and PTP-1B expression was measured via immunoblotting. Results. PTP-1B increased posthypoxia by about 30% and persisted for 2 weeks while Src kinase inhibition attenuated the expected PTP-1B-increased expression. Conclusions. Our study suggests that Src kinase mediates a hypoxia-induced increased PTP-1B expression.

  3. Specific inhibition of hypoxia-inducible factor (HIF)-1 alpha activation and of vascular endothelial growth factor (VEGF) production by flavonoids.

    Hasebe, Yuki; Egawa, Kiyoshi; Yamazaki, Yoko; Kunimoto, Setsuko; Hirai, Yasuaki; Ida, Yoshiteru; Nose, Kiyoshi

    2003-10-01

    Screening using a reporter under the control of the hypoxia-response element (HRE) identified several flavonoids and homoisoflavonoids that inhibit the activation of HRE under hypoxic conditions. Among various compounds, isorhamnetin, luteolin, quercetin, and methyl ophiopogonanone B (MOB) were effective at 3 to 9 microg/ml in inhibiting the reporter activity. The expression of vascular endothelial growth factor (VEGF) mRNA during hypoxia was also inhibited by MOB in HepG2 cells, but the effective doses were 10 to 20 microg/ml. MOB caused destabilization of hypoxia-inducible factor (HIF)-1alpha, as revealed by Western blotting, that was dependent on proteasome activity and the tumor suppressor, p53. The tubular formation and migration of human umbilical vein endothelial cells was also inhibited by MOB. MOB is expected to act as an inhibitor of angiogenesis.

  4. Erythropoietin inhibits HIF-1α expression via upregulation of PHD-2 transcription and translation in an in-vitro model of hypoxia ischemia

    Souvenir, Rhonda; Flores, Jerry J.; Ostrowski, Robert P.; Manaenko, Anatol; Duris, Kamil; Tang, Jiping

    2014-01-01

    Hypoxia inducible factor (HIF)-1α is the central transcriptional factor for the regulation of oxygen-associated genes in response to hypoxia. Erythropoietin (EPO), a hematopoietic growth factor, increases oxygen availability during hypoxia/ischemia and is associated with neuroprotection following hypoxia ischemia in laboratory models of stroke. However, EPO has failed to translate in a clinical setting. Thus it is critical to elucidate the key players in EPO-induced neuroprotection. Our preliminary studies have shown that EPO, as a downstream gene of hypoxia inducible factor (HIF), inhibits HIF-1α in a dose-dependent manner in an in-vitro model of hypoxia ischemia. This study is designed to elucidate the primary mediator of EPO-induced HIF-1α inhibition and subsequent cell survival/neuroprotection. Oxygen and glucose deprivation (OGD) of nerve growth factor (NGF) differentiated rat pheochromocytoma (PC-12) cells were used to model hypoxia ischemia in an in vitro environment. The profile of HIF-1α, HIF-2α and PHD-2 expression, HIF-1α and prolyl hydroxylase (PHD-2) mRNA levels, MMP-9 and cell death was evaluated in the presence and absence of either EPO or PHD-2 inhibitor during OGD. Our findings showed that EPO treatment resulted in an increase in PHD-2 transcription and translation, inhibition of HIF-1α expression, reactive oxygen species (ROS) formation and matrix metalloproteinase (MMP)-9 activity, resulting in increased cell survival after OGD. We also observed that EPO-induced cell survival/neuroprotection was reversed by siRNA silencing of PHD-2. This led to the conclusion that PHD-2 is a key mediator of EPO-induced HIF-1α inhibition and subsequent neuroprotection in an in vitro model of hypoxia ischemia. PMID:24323731

  5. Effects of HIF-1 inhibition by chetomin on hypoxia-related transcription and radiosensitivity in HT 1080 human fibrosarcoma cells

    Staab, Adrian; Einsele, Hermann; Flentje, Michael; Vordermark, Dirk; Loeffler, Jürgen; Said, Harun M; Diehlmann, Désirée; Katzer, Astrid; Beyer, Melanie; Fleischer, Markus; Schwab, Franz; Baier, Kurt

    2007-01-01

    Hypoxia-inducible factor-1 (HIF-1) overexpression has been linked to tumor progression and poor prognosis. We investigated whether targeting of HIF-1 using chetomin, a disrupter of the interaction of HIF-1 with the transcriptional coactivator p300, influences the radiosensitivity of hypoxic HT 1080 human fibrosarcoma cells. Optimal dose of chetomin was determined by EGFP-HRE gene reporter assay in stably transfected HT 1080 cells. Cells were assayed for expression of the hypoxia-inducible genes carbonic anhydrase 9 (CA9) and vascular endothelial growth factor (VEGF) by RT-PCR and for clonogenic survival after irradiation with 2, 5 or 10 Gy, under normoxic or hypoxic (0.1% O 2 , 12 h) conditions in the presence or absence of chetomin (150 nM, 12 h, pre-treatment of 4 h). Chetomin treatment significantly reduced CA9 and VEGF mRNA expression in hypoxic cells to 44.4 ± 7.2% and 39.6 ± 16.0%, respectively, of untreated hypoxic controls. Chetomin clearly reduced the modified oxygen enhancement ratio (OER') compared to untreated cells, from 2.02 to 1.27, from 1.86 to 1.22 and from 1.49 to 1.06 at the 50%, 37% and 10% clonogenic survival levels, respectively. HIF-1 inhibition by chetomin effectively reduces hypoxia-dependent transcription and radiosensitizes hypoxic HT 1080 human fibrosarcoma cells in vitro

  6. PACAP and VIP inhibit the invasiveness of glioblastoma cells exposed to hypoxia through the regulation of HIFs and EGFR expression

    Grazia eMaugeri

    2016-05-01

    Full Text Available Pituitary adenylate cyclase-activating polypeptide (PACAP and vasoactive intestinal peptide (VIP through the binding of vasoactive intestinal peptide receptors (VIPRs, perform a wide variety of effects in human cancers, including glioblastoma multiforme (GBM. This tumor is characterized by extensive areas of hypoxia, which triggers the expression of hypoxia-inducible factors (HIFs. HIFs not only mediate angiogenesis but also tumor cell migration and invasion. Furthermore, HIFs activation is linked to epidermal growth factor receptor (EGFR overexpression. Previous studies have shown that VIP interferes with the invasive nature of gliomas by regulating cell migration. However, the role of VIP family members in GBM infiltration under low oxygen tension has not been clarified yet. Therefore, in the present study we have investigated, for the first time, the molecular mechanisms involved in the anti-invasive effect of PACAP or VIP in U87MG glioblastoma cells exposed to hypoxia induced by treatment with desferrioxamine (DFX. The results suggest that either PACAP or VIP exert an anti-infiltrative effect under low oxygen tension by modulating HIFs and EGFR expression, key elements involved in cell migration and angiogenesis. These peptides act through the inhibition of PI3K/Akt and MAPK/ERK signaling pathways, which are known to have a crucial role in HIFs regulation. In conclusion, the modulation of hypoxic event and the anti-invasive effect exerted by some VIP family members might open new insights in the therapeutic approach to GBM.

  7. Baicalin inhibits hypoxia-induced pulmonary artery smooth muscle cell proliferation via the AKT/HIF-1α/p27-associated pathway.

    Zhang, Lin; Pu, Zhichen; Wang, Junsong; Zhang, Zhifeng; Hu, Dongmei; Wang, Junjie

    2014-05-09

    Baicalin, a flavonoid compound purified from the dry roots of Scutellaria baicalensis Georgi, has been shown to possess various pharmacological actions. Previous studies have revealed that baicalin inhibits the growth of cancer cells through the induction of apoptosis. Pulmonary arterial hypertension (PAH) is a devastating disease characterized by enhanced pulmonary artery smooth muscle cell (PASMCs) proliferation and suppressed apoptosis. However, the potential mechanism of baicalin in the regulation of PASMC proliferation and the prevention of cardiovascular diseases remains unexplored. To test the effects of baicalin on hypoxia, we used rats treated with or without baicalin (100 mg·kg⁻¹ each rat) at the beginning of the third week after hypoxia. Hemodynamic and pulmonary pathomorphology data showed that right ventricular systolic pressures (RVSP), the weight of the right ventricle/left ventricle plus septum (RV/LV + S) ratio and the medial width of pulmonary arterioles were much higher in chronic hypoxia. However, baicalin treatment repressed the elevation of RVSP, RV/LV + S and attenuated the pulmonary vascular structure remodeling (PVSR) of pulmonary arterioles induced by chronic hypoxia. Additionally, baicalin (10 and 20 μmol·L⁻¹) treatment suppressed the proliferation of PASMCs and attenuated the expression of hypoxia-inducible factor-α (HIF-α) under hypoxia exposure. Meanwhile, baicalin reversed the hypoxia-induced reduction of p27 and increased AKT/protein kinase B phosphorylation p-AKT both in vivo and in vitro. These results suggested that baicalin could effectively attenuate PVSR and hypoxic pulmonary hypertension.

  8. Propofol inhibits hypoxia/reoxygenation-induced human gastric epithelial cell injury by suppressing the Toll-like receptor 4 pathway

    Jiao-Li Zhang

    2013-06-01

    Full Text Available This study aimed to investigate the role of the Toll-like receptor 4 (TLR4 pathway in normal human gastric epithelial (GES-1 cells under hypoxia/reoxygenation (H/R in vitro, and the effect of propofol on injured GES-1 cells as well as its possible mechanism. Before H/R induction, GES-1 cells were preconditioned with fat emulsion, propofol, or epigallocatechin gallate. Then cell viability, cell apoptosis, and related molecules in the cells were analyzed under experimental conditions. We found that propofol 50 μmol/L markedly inhibited the H/R injury under hypoxia 1.5 h/reoxygenation 2 hours by promoting GES-1 cell viability and decreasing cell apoptosis. The TLR4 signal may be involved in the protective effect of propofol against H/R injury. The malondialdehyde contents and superoxide dismutase activities were recovered under propofol preconditioning. In summary, propofol preconditioning may exert a protective effect on H/R injury in GES-1 cells and the mechanism may be via inhibition of the activated TLR4 signal under H/R conditions.

  9. Erythropoietin inhibits HIF-1α expression via upregulation of PHD-2 transcription and translation in an in vitro model of hypoxia-ischemia.

    Souvenir, Rhonda; Flores, Jerry J; Ostrowski, Robert P; Manaenko, Anatol; Duris, Kamil; Tang, Jiping

    2014-02-01

    Hypoxia inducible factor (HIF)-1α is the central transcriptional factor for the regulation of oxygen-associated genes in response to hypoxia. Erythropoietin (EPO), a hematopoietic growth factor, increases oxygen availability during hypoxia/ischemia and is associated with neuroprotection following hypoxia-ischemia in laboratory models of stroke. However, EPO has failed to translate in a clinical setting. Thus, it is critical to elucidate the key players in EPO-induced neuroprotection. Our preliminary studies have shown that EPO, as a downstream gene of HIF, inhibits HIF-1α in a dose-dependent manner in an in vitro model of hypoxia-ischemia. This study is designed to elucidate the primary mediator of EPO-induced HIF-1α inhibition and subsequent cell survival/neuroprotection. Oxygen and glucose deprivation (OGD) of nerve growth factor-differentiated rat pheochromocytoma (PC-12) cells were used to model hypoxia-ischemia in an in vitro environment. The profile of HIF-1α, HIF-2α and prolyl hydroxylase domain 2 (PHD-2) expression; HIF-1α and prolyl hydroxylase (PHD-2) mRNA levels; matrix metalloproteinase (MMP)-9; and cell death was evaluated in the presence and absence of either EPO or PHD-2 inhibitor during OGD. Our findings showed that EPO treatment resulted in an increase in PHD-2 transcription and translation, inhibition of HIF-1α expression, reactive oxygen species formation, and MMP-9 activity, resulting in increased cell survival after OGD. We also observed that EPO-induced cell survival/neuroprotection was reversed by siRNA silencing of PHD-2. This led to the conclusion that PHD-2 is a key mediator of EPO-induced HIF-1α inhibition and subsequent neuroprotection in an in vitro model of hypoxia-ischemia.

  10. Hypoxia-induced autophagy is inhibited by PADI4 knockdown, which promotes apoptosis of fibroblast-like synoviocytes in rheumatoid arthritis

    Fan, Tingting; Zhang, Changsong; Zong, Ming; Fan, Lieying

    2018-01-01

    Impaired apoptosis of rheumatoid arthritis (RA)-fibroblast-like synoviocytes (FLS) is pivotal in the process of RA. Peptidyl arginine deiminase type IV (PADI4) is associated with autoantibody regulation via histone citrullination in RA. The present study aimed to investigate the role of PADI4 in the apoptosis of RA-FLS. FLS were isolated from patients with RA and a rat model. The effects of PADI4 on RA-FLS were investigated in vitro and in vivo. Hypoxia-induced autophagy was induced by 1% O2 and was detected by immunohistochemical and immunofluorescence analysis; in addition, apoptosis was detected by flow cytometry. RA-FLS obtained from RA rat model exhibited significant proliferation under severe hypoxia conditions. Hypoxia also significantly induced autophagy and elevated the expression of PADI4. Subsequently, short hairpin RNA-mediated PADI4 knockdown was demonstrated to significantly inhibit hypoxia-induced autophagy and promote apoptosis in RA-FLS. The results of these in vitro and in vivo studies suggested that PADI4 may be closely associated with hypoxia-induced autophagy, and the inhibition of hypoxia-induced autophagy by PADI4 knockdown may contribute to an increase in the apoptosis of RA-FLS. PMID:29393388

  11. Successful tumour necrosis factor (TNF) blocking therapy suppresses oxidative stress and hypoxia-induced mitochondrial mutagenesis in inflammatory arthritis

    Biniecka, Monika

    2011-07-25

    Abstract Introduction To examine the effects of tumour necrosis factor (TNF) blocking therapy on the levels of early mitochondrial genome alterations and oxidative stress. Methods Eighteen inflammatory arthritis patients underwent synovial tissue oxygen (tpO2) measurements and clinical assessment of disease activity (DAS28-CRP) at baseline (T0) and three months (T3) after starting biologic therapy. Synovial tissue lipid peroxidation (4-HNE), T and B cell specific markers and synovial vascular endothelial growth factor (VEGF) were quantified by immunohistochemistry. Synovial levels of random mitochondrial DNA (mtDNA) mutations were assessed using Random Mutation Capture (RMC) assay. Results 4-HNE levels pre\\/post anti TNF-α therapy were inversely correlated with in vivo tpO2 (P < 0.008; r = -0.60). Biologic therapy responders showed a significantly reduced 4-HNE expression (P < 0.05). High 4-HNE expression correlated with high DAS28-CRP (P = 0.02; r = 0.53), tender joint count for 28 joints (TJC-28) (P = 0.03; r = 0.49), swollen joint count for 28 joints (SJC-28) (P = 0.03; r = 0.50) and visual analogue scale (VAS) (P = 0.04; r = 0.48). Strong positive association was found between the number of 4-HNE positive cells and CD4+ cells (P = 0.04; r = 0.60), CD8+ cells (P = 0.001; r = 0.70), CD20+ cells (P = 0.04; r = 0.68), CD68+ cells (P = 0.04; r = 0.47) and synovial VEGF expression (P = 0.01; r = 063). In patients whose in vivo tpO2 levels improved post treatment, significant reduction in mtDNA mutations and DAS28-CRP was observed (P < 0.05). In contrast in those patients whose tpO2 levels remained the same or reduced at T3, no significant changes for mtDNA mutations and DAS28-CRP were found. Conclusions High levels of synovial oxidative stress and mitochondrial mutation burden are strongly associated with low in vivo oxygen tension and synovial inflammation. Furthermore these significant mitochondrial genome alterations are rescued following successful anti TNF

  12. Imaging oxygenation of human tumours

    Padhani, Anwar R.; Krohn, Kenneth A.; Lewis, Jason S.; Alber, Markus

    2007-01-01

    Tumour hypoxia represents a significant challenge to the curability of human tumours leading to treatment resistance and enhanced tumour progression. Tumour hypoxia can be detected by non-invasive and invasive techniques but the inter-relationships between these remains largely undefined. 18 F-MISO and Cu-ATSM-PET, and BOLD-MRI are the lead contenders for human application based on their non-invasive nature, ease of use and robustness, measurement of hypoxia status, validity, ability to demonstrate heterogeneity and general availability, these techniques are the primary focus of this review. We discuss where developments are required for hypoxia imaging to become clinically useful and explore potential new uses for hypoxia imaging techniques including biological conformal radiotherapy. (orig.)

  13. Inhibiting effect of plasma from normal and tumour bearing mice on the mitotic rate of regenerating liver.

    Echave Llanos, J M; Moreno, F R; Badrán, A F

    1986-01-01

    Plasma from normal mice and from mice bearing the ES2 transplantable malignant tumour was injected intraperitoneally at a dose of 0.01 ml/g body weight in partially hepatectomized mice. Control animals were injected with a solution of sodium citrate in saline. The recipients were killed at the first (14:00 hours/48 h). These times are the time of day and the number of h after partial hepatectomy and second (14:00 hours/72 h) peak times after partial hepatectomy. The number of colchicine metaphases per 1000 nuclei was determined for hepatocytes and litoral cells. A different effect was obtained with plasma from tumour-bearing compared with normal mice. Plasma from both sources when injected 26 h after partial hepatectomy (16:00 hours/26 h) inhibited the mitotic activity of hepatocytes at the next peak of regenerative activity (14:00 hours/48 h). The plasma from tumour-bearing mice also inhibited the peak on the following day (14:00 hours/72 h), whereas plasma from normal mice had no inhibitory effect and, indeed, a compensatory wave was observed at this time. Furthermore, plasma from tumour-bearing mice also showed an inhibitory effect at the first peak (14:00 hours/48 h) when injected at the time of partial hepatectomy (14:00 hours/00 h) or at 22 h before partial hepatectomy (16:00 hours/-22 h) whereas the injection of plasma from normal mice at these times had no inhibitory effect. In the litoral cells the injection of plasma from tumour-bearing mice made 22 h before hepatectomy (16:00 hours/-22 h) led to a stimulation of mitotic activity which was controlled at 14:00 hours/48 h.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. Silibinin inhibits hypoxia-induced HIF-1α-mediated signaling, angiogenesis and lipogenesis in prostate cancer cells: In vitro evidence and in vivo functional imaging and metabolomics.

    Deep, Gagan; Kumar, Rahul; Nambiar, Dhanya K; Jain, Anil K; Ramteke, Anand M; Serkova, Natalie J; Agarwal, Chapla; Agarwal, Rajesh

    2017-03-01

    Hypoxia is associated with aggressive phenotype and poor prognosis in prostate cancer (PCa) patients suggesting that PCa growth and progression could be controlled via targeting hypoxia-induced signaling and biological effects. Here, we analyzed silibinin (a natural flavonoid) efficacy to target cell growth, angiogenesis, and metabolic changes in human PCa, LNCaP, and 22Rv1 cells under hypoxic condition. Silibinin treatment inhibited the proliferation, clonogenicity, and endothelial cells tube formation by hypoxic (1% O 2 ) PCa cells. Interestingly, hypoxia promoted a lipogenic phenotype in PCa cells via activating acetyl-Co A carboxylase (ACC) and fatty acid synthase (FASN) that was inhibited by silibinin treatment. Importantly, silibinin treatment strongly decreased hypoxia-induced HIF-1α expression in PCa cells together with a strong reduction in hypoxia-induced NADPH oxidase (NOX) activity. HIF-1α overexpression in LNCaP cells significantly increased the lipid accumulation and NOX activity; however, silibinin treatment reduced HIF-1α expression, lipid levels, clonogenicity, and NOX activity even in HIF-1α overexpressing LNCaP cells. In vivo, silibinin feeding (200 mg/kg body weight) to male nude mice with 22Rv1 tumors, specifically inhibited tumor vascularity (measured by dynamic contrast-enhanced MRI) resulting in tumor growth inhibition without directly inducing necrosis (as revealed by diffusion-weighted MRI). Silibinin feeding did not significantly affect tumor glucose uptake measured by FDG-PET; however, reduced the lipid synthesis measured by quantitative 1 H-NMR metabolomics. IHC analyses of tumor tissues confirmed that silibinin feeding decreased proliferation and angiogenesis as well as reduced HIF-1α, FASN, and ACC levels. Together, these findings further support silibinin usefulness against PCa through inhibiting hypoxia-induced signaling. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  15. Development of a Tumour Growth Inhibition Model to Elucidate the Effects of Ritonavir on Intratumoural Metabolism and Anti-tumour Effect of Docetaxel in a Mouse Model for Hereditary Breast Cancer.

    Yu, Huixin; Hendrikx, Jeroen J M A; Rottenberg, Sven; Schellens, Jan H M; Beijnen, Jos H; Huitema, Alwin D R

    2016-03-01

    In a mouse tumour model for hereditary breast cancer, we previously explored the anti-cancer effects of docetaxel, ritonavir and the combination of both and studied the effect of ritonavir on the intratumoural concentration of docetaxel. The objective of the current study was to apply pharmacokinetic (PK)-pharmacodynamic (PD) modelling on this previous study to further elucidate and quantify the effects of docetaxel when co-administered with ritonavir. PK models of docetaxel and ritonavir in plasma and in tumour were developed. The effect of ritonavir on docetaxel concentration in the systemic circulation of Cyp3a knock-out mice and in the implanted tumour (with inherent Cyp3a expression) was studied, respectively. Subsequently, we designed a tumour growth inhibition model that included the inhibitory effects of both docetaxel and ritonavir. Ritonavir decreased docetaxel systemic clearance with 8% (relative standard error 0.4%) in the co-treated group compared to that in the docetaxel only-treated group. The docetaxel concentration in tumour tissues was significantly increased by ritonavir with mean area under the concentration-time curve 2.5-fold higher when combined with ritonavir. Observed tumour volume profiles in mice could be properly described by the PK/PD model. In the co-treated group, the enhanced anti-tumour effect was mainly due to increased docetaxel tumour concentration; however, we demonstrated a small but significant anti-tumour effect of ritonavir addition (p value effect observed when docetaxel is combined with ritonavir is mainly caused by enhanced docetaxel tumour concentration and to a minor extent by a direct anti-tumour effect of ritonavir.

  16. The role of mRNA translation in the adaptation to hypoxia

    Koritzinsky, M.; Wouters, B.G.; Koumenis, C.

    2003-01-01

    Hypoxia commonly occurs in human tumours and is associated with a poor prognosis. We and others have shown that global mRNA translation is rapidly inhibited during hypoxia. However, some mRNAs, such as those coding for HIF-1 α and VEGF, remain efficiently translated. We therefore hypothesize that the inhibition of mRNA translation serves to promote hypoxia tolerance in two ways: i) through conservation of energy and ii) through differential gene expression involved in hypoxia adaptation. We are investigating the mechanisms responsible for the down regulation of protein synthesis during hypoxia, and how specific mRNAs maintain their ability to be translated under such conditions. Our goal is to understand the significance of these regulatory mechanisms for hypoxia tolerance in vitro and tumor growth in vivo. We have previously shown that one mechanism responsible for inhibiting protein synthesis during hypoxia is the activation of PERK, which inhibits the essential translation factor eIF2 α . Here we show that PERK-/- MEFs are not able to inhibit protein synthesis efficiently during hypoxia and are significantly less tolerant to hypoxia than wt cells. We also show that other mechanisms are important for sustained low protein synthesis during chronic hypoxia. We demonstrate that the eIF4F complex is disrupted during prolonged hypoxia, and that this is mediated by 4E-BP1 and 4E-T. eIF4F is essential for translation which is dependent upon the 5'mRNA cap-structure. These studies therefore indicate a switch from the inhibition of all translation through eIF2 α during acute hypoxia, to the inhibition of only cap-dependent translation during chronic hypoxia. This model predicts the differential induction of genes that can be translated cap-independently during chronic hypoxia, which is consistent with the observed differential translation of HIF-1 α and VEGF. The functional significance of the disruption of the eIF4F complex during hypoxia is currently being addressed

  17. EGFR-TK inhibition before radiotherapy reduces tumour volume but does not improve local control: Differential response of cancer stem cells and nontumourigenic cells?

    Krause, Mechthild; Prager, Jenny; Zhou Xuanjing; Yaromina, Ala; Doerfler, Annegret; Eicheler, Wolfgang; Baumann, Michael

    2007-01-01

    Background and purpose: Waiting times before radiotherapy may reduce tumour control probability due to proliferation of tumour cells. The aim of the experiment was to test whether the growth inhibiting effect of epidermal growth factor receptor (EGFR)-inhibitors after surgery or tumour transplantation results in a lower tumour mass at time of irradiation and can thereby improve local tumour control. Materials and methods: The EGFR-tyrosine kinase inhibitor BIBX1382BS was applied over 14 days starting from microscopically non-in-sano-resection of FaDu tumours or from tumour transplantation, followed by irradiation (5f/5d). Endpoint was local tumour control. In addition, vital tumour areas, pimonidazole hypoxic fraction, BrdU labelling index, and colony forming ability in vitro were tested in control tumours and after BIBX1382BS treatment (starting from transplantation). Results: The tumour volume at start of irradiation was significantly lower in the BIBX1382BS treated tumours as compared to the control groups by factors of 11 (post-surgery setting) and 2.7 (transplantation setting). However, the reduced volume did not translate into improved local control after irradiation. The TCD 50 values after surgery were 25.4 Gy [95% CI 18; 33 Gy] in the control group and 30.5 Gy [24; 37] in the BIBX1382BS group (p = 0.25). Treatment after transplantation resulted in TCD 50 values of 41.1 Gy [35; 47] in the control group and 41.1 Gy [33; 49] in the BIBX1382BS group (p = 1). While the proportion of S-phase cells decreased after BIBX1382BS treatment, no differences were observed between the pimonidazole hypoxic fractions and in vitro colony forming ability. Conclusions: EGFR-TK inhibition with BIBX1382BS over 14 days between macroscopically complete tumour resection or tumour transplantation and start of radiotherapy significantly reduced tumour volume but did not improve local tumour control. One possible explanation is that the EGFR-TK inhibitor has a higher activity in

  18. Targeting multiple cannabinoid anti-tumour pathways with a resorcinol derivative leads to inhibition of advanced stages of breast cancer.

    Murase, Ryuichi; Kawamura, Rumi; Singer, Eric; Pakdel, Arash; Sarma, Pranamee; Judkins, Jonathon; Elwakeel, Eiman; Dayal, Sonali; Martinez-Martinez, Esther; Amere, Mukkanti; Gujjar, Ramesh; Mahadevan, Anu; Desprez, Pierre-Yves; McAllister, Sean D

    2014-10-01

    The psychoactive cannabinoid Δ(9) -tetrahydrocannabinol (THC) and the non-psychoactive cannabinoid cannabidiol (CBD) can both reduce cancer progression, each through distinct anti-tumour pathways. Our goal was to discover a compound that could efficiently target both cannabinoid anti-tumour pathways. To measure breast cancer cell proliferation/viability and invasion, MTT and Boyden chamber assays were used. Modulation of reactive oxygen species (ROS) and apoptosis was measured using dichlorodihydrofluorescein and annexin/propidium iodide, respectively, in combination with cell flow cytometry. Changes in protein levels were evaluated using Western analysis. Orthotopic and i.v. mouse models of breast cancer metastasis were used to test the activity of cannabinoids in vivo. CBD reduced breast cancer metastasis in advanced stages of the disease as the direct result of down-regulating the transcriptional regulator Id1. However, this was associated with moderate increases in survival. We therefore screened for analogues that could co-target cannabinoid anti-tumour pathways (CBD- and THC-associated) and discovered the compound O-1663. This analogue inhibited Id1, produced a marked stimulation of ROS, up-regulated autophagy and induced apoptosis. Of all the compounds tested, it was the most potent at inhibiting breast cancer cell proliferation and invasion in culture and metastasis in vivo. O-1663 prolonged survival in advanced stages of breast cancer metastasis. Developing compounds that can simultaneously target multiple cannabinoid anti-tumour pathways efficiently may provide a novel approach for the treatment of patients with metastatic breast cancer. © 2014 The British Pharmacological Society.

  19. MicroRNA-210 Modulates Endothelial Cell Response to Hypoxia and Inhibits the Receptor Tyrosine Kinase Ligand Ephrin-A3*S⃞

    Fasanaro, Pasquale; D'Alessandra, Yuri; Di Stefano, Valeria; Melchionna, Roberta; Romani, Sveva; Pompilio, Giulio; Capogrossi, Maurizio C.; Martelli, Fabio

    2008-01-01

    MicroRNAs (miRNAs) are small non-protein-coding RNAs that function as negative gene expression regulators. In the present study, we investigated miRNAs role in endothelial cell response to hypoxia. We found that the expression of miR-210 progressively increased upon exposure to hypoxia. miR-210 overexpression in normoxic endothelial cells stimulated the formation of capillary-like structures on Matrigel and vascular endothelial growth factor-driven cell migration. Conversely, miR-210 blockade via anti-miRNA transfection inhibited the formation of capillary-like structures stimulated by hypoxia and decreased cell migration in response to vascular endothelial growth factor. miR-210 overexpression did not affect endothelial cell growth in both normoxia and hypoxia. However, anti-miR-210 transfection inhibited cell growth and induced apoptosis, in both normoxia and hypoxia. We determined that one relevant target of miR-210 in hypoxia was Ephrin-A3 since miR-210 was necessary and sufficient to down-modulate its expression. Moreover, luciferase reporter assays showed that Ephrin-A3 was a direct target of miR-210. Ephrin-A3 modulation by miR-210 had significant functional consequences; indeed, the expression of an Ephrin-A3 allele that is not targeted by miR-210 prevented miR-210-mediated stimulation of both tubulogenesis and chemotaxis. We conclude that miR-210 up-regulation is a crucial element of endothelial cell response to hypoxia, affecting cell survival, migration, and differentiation. PMID:18417479

  20. Intermittent Hypoxia Inhibits Na+-H+ Exchange-Mediated Acid Extrusion Via Intracellular Na+ Accumulation in Cardiomyocytes

    Huai-Ren Chang

    2018-04-01

    Full Text Available Background/Aims: Intermittent hypoxia (IH has been shown to exert preconditioning-like cardioprotective effects. It also has been reported that IH preserves intracellular pH (pHi during ischemia and protects cardiomyocytes against ischemic reperfusion injury. However, the exact mechanism is still unclear. Methods: In this study, we used proton indicator BCECF-AM to analyze the rate of pHi recovery from acidosis in the IH model of rat neonatal cardiomyocytes. Neonatal cardiomyocytes were first treated with repetitive hypoxia-normoxia cycles for 1-4 days. Cells were then acid loaded with NH4Cl, and the rate of pHi recovery from acidosis was measured. Results: We found that the pHi recovery rate from acidosis was much slower in the IH group than in the room air (RA group. When we treated cardiomyocytes with Na+-H+ exchange (NHE inhibitors (Amiloride and HOE642 or Na+-free Tyrode solution during the recovery, there was no difference between RA and IH groups. We also found intracellular Na+ concentration ([Na+]i significantly increased after IH exposure for 4 days. However, the phenomenon could be abolished by pretreatment with ROS inhibitors (SOD and phenanathroline, intracellular calcium chelator or Na+-Ca2+ exchange (NCX inhibitor. Furthermore, the pHi recovery rate from acidosis became faster in the IH group than in the RA group when inhibition of NCX activity. Conclusions: These results suggest that IH would induce the elevation of ROS production. ROS then activates Ca2+-efflux mode of NCX and results in intracellular Na+ accumulation. The rise of [Na+]i further inhibits the activity of NHE-mediated acid extrusion and retards the rate of pHi recovery from acidosis during IH.

  1. BAY 87-2243, a highly potent and selective inhibitor of hypoxia-induced gene activation has antitumor activities by inhibition of mitochondrial complex I

    Ellinghaus, Peter; Heisler, Iring; Unterschemmann, Kerstin; Haerter, Michael; Beck, Hartmut; Greschat, Susanne; Ehrmann, Alexander; Summer, Holger; Flamme, Ingo; Oehme, Felix; Thierauch, Karlheinz; Michels, Martin; Hess-Stumpp, Holger; Ziegelbauer, Karl

    2013-01-01

    The activation of the transcription factor hypoxia-inducible factor-1 (HIF-1) plays an essential role in tumor development, tumor progression, and resistance to chemo- and radiotherapy. In order to identify compounds targeting the HIF pathway, a small molecule library was screened using a luciferase-driven HIF-1 reporter cell line under hypoxia. The high-throughput screening led to the identification of a class of aminoalkyl-substituted compounds that inhibited hypoxia-induced HIF-1 target gene expression in human lung cancer cell lines at low nanomolar concentrations. Lead structure BAY 87-2243 was found to inhibit HIF-1α and HIF-2α protein accumulation under hypoxic conditions in non-small cell lung cancer (NSCLC) cell line H460 but had no effect on HIF-1α protein levels induced by the hypoxia mimetics desferrioxamine or cobalt chloride. BAY 87-2243 had no effect on HIF target gene expression levels in RCC4 cells lacking Von Hippel–Lindau (VHL) activity nor did the compound affect the activity of HIF prolyl hydroxylase-2. Antitumor activity of BAY 87-2243, suppression of HIF-1α protein levels, and reduction of HIF-1 target gene expression in vivo were demonstrated in a H460 xenograft model. BAY 87-2243 did not inhibit cell proliferation under standard conditions. However under glucose depletion, a condition favoring mitochondrial ATP generation as energy source, BAY 87-2243 inhibited cell proliferation in the nanomolar range. Further experiments revealed that BAY 87-2243 inhibits mitochondrial complex I activity but has no effect on complex III activity. Interference with mitochondrial function to reduce hypoxia-induced HIF-1 activity in tumors might be an interesting therapeutic approach to overcome chemo- and radiotherapy-resistance of hypoxic tumors

  2. Schedule-dependent inhibition of hypoxia-inducible factor-1alpha protein accumulation, angiogenesis, and tumor growth by topotecan in U251-HRE glioblastoma xenografts.

    Rapisarda, Annamaria; Zalek, Jessica; Hollingshead, Melinda; Braunschweig, Till; Uranchimeg, Badarch; Bonomi, Carrie A; Borgel, Suzanne D; Carter, John P; Hewitt, Stephen M; Shoemaker, Robert H; Melillo, Giovanni

    2004-10-01

    We have previously shown that topotecan, a topoisomerase I poison, inhibits hypoxia-inducible factor (HIF)-1alpha protein accumulation by a DNA damage-independent mechanism. Here, we report that daily administration of topotecan inhibits HIF-1alpha protein expression in U251-HRE glioblastoma xenografts. Concomitant with HIF-1alpha inhibition, topotecan caused a significant tumor growth inhibition associated with a marked decrease of angiogenesis and expression of HIF-1 target genes in tumor tissue. These results provide a compelling rationale for testing topotecan in clinical trials to target HIF-1 in cancer patients.

  3. Imatinib mesylate exerts anti-proliferative effects on osteosarcoma cells and inhibits the tumour growth in immunocompetent murine models.

    Bérengère Gobin

    Full Text Available Osteosarcoma is the most common primary malignant bone tumour characterized by osteoid production and/or osteolytic lesions of bone. A lack of response to chemotherapeutic treatments shows the importance of exploring new therapeutic methods. Imatinib mesylate (Gleevec, Novartis Pharma, a tyrosine kinase inhibitor, was originally developed for the treatment of chronic myeloid leukemia. Several studies revealed that imatinib mesylate inhibits osteoclast differentiation through the M-CSFR pathway and activates osteoblast differentiation through PDGFR pathway, two key cells involved in the vicious cycle controlling the tumour development. The present study investigated the in vitro effects of imatinib mesylate on the proliferation, apoptosis, cell cycle, and migration ability of five osteosarcoma cell lines (human: MG-63, HOS; rat: OSRGA; mice: MOS-J, POS-1. Imatinib mesylate was also assessed as a curative and preventive treatment in two syngenic osteosarcoma models: MOS-J (mixed osteoblastic/osteolytic osteosarcoma and POS-1 (undifferentiated osteosarcoma. Imatinib mesylate exhibited a dose-dependent anti-proliferative effect in all cell lines studied. The drug induced a G0/G1 cell cycle arrest in most cell lines, except for POS-1 and HOS cells that were blocked in the S phase. In addition, imatinib mesylate induced cell death and strongly inhibited osteosarcoma cell migration. In the MOS-J osteosarcoma model, oral administration of imatinib mesylate significantly inhibited the tumour development in both preventive and curative approaches. A phospho-receptor tyrosine kinase array kit revealed that PDGFRα, among 7 other receptors (PDFGFRβ, Axl, RYK, EGFR, EphA2 and 10, IGF1R, appears as one of the main molecular targets for imatinib mesylate. In the light of the present study and the literature, it would be particularly interesting to revisit therapeutic evaluation of imatinib mesylate in osteosarcoma according to the tyrosine-kinase receptor

  4. Hypoxia-induced cytotoxic drug resistance in osteosarcoma is independent of HIF-1Alpha.

    Jennifer Adamski

    Full Text Available Survival rates from childhood cancer have improved dramatically in the last 40 years, such that over 80% of children are now cured. However in certain subgroups, including metastatic osteosarcoma, survival has remained stubbornly poor, despite dose intensive multi-agent chemotherapy regimens, and new therapeutic approaches are needed. Hypoxia is common in adult solid tumours and is associated with treatment resistance and poorer outcome. Hypoxia induces chemotherapy resistance in paediatric tumours including neuroblastoma, rhabdomyosarcoma and Ewing's sarcoma, in vitro, and this drug resistance is dependent on the oxygen-regulated transcription factor hypoxia inducible factor-1 (HIF-1. In this study the effects of hypoxia on the response of the osteosarcoma cell lines 791T, HOS and U2OS to the clinically relevant cytotoxics cisplatin, doxorubicin and etoposide were evaluated. Significant hypoxia-induced resistance to all three agents was seen in all three cell lines and hypoxia significantly reduced drug-induced apoptosis. Hypoxia also attenuated drug-induced activation of p53 in the p53 wild-type U2OS osteosarcoma cells. Drug resistance was not induced by HIF-1α stabilisation in normoxia by cobalt chloride nor reversed by the suppression of HIF-1α in hypoxia by shRNAi, siRNA, dominant negative HIF or inhibition with the small molecule NSC-134754, strongly suggesting that hypoxia-induced drug resistance in osteosarcoma cells is independent of HIF-1α. Inhibition of the phosphoinositide 3-kinase (PI3K pathway using the inhibitor PI-103 did not reverse hypoxia-induced drug resistance, suggesting the hypoxic activation of Akt in osteosarcoma cells does not play a significant role in hypoxia-induced drug resistance. Targeting hypoxia is an exciting prospect to improve current anti-cancer therapy and combat drug resistance. Significant hypoxia-induced drug resistance in osteosarcoma cells highlights the potential importance of hypoxia as a target

  5. Inhibition of phospholipaseD2 increases hypoxia-induced human colon cancer cell apoptosis through inactivating of the PI3K/AKT signaling pathway.

    Liu, Maoxi; Fu, Zhongxue; Wu, Xingye; Du, Kunli; Zhang, Shouru; Zeng, Li

    2016-05-01

    Hypoxia is a common feature of solid tumor, and is a direct stress that triggers apoptosis in many human cell types. As one of solid cancer, hypoxia exists in the whole course of colon cancer occurrence and progression. Our previous studies shown that hypoxia induce high expression of phospholipase D2 (PLD2) and survivin in colon cancer cells. However, the correlation between PLD2 and survivin in hypoxic colon cancer cells remains unknown. In this study, we observed significantly elevated PLD2 and survivin expression levels in colon cancer tissues and cells. This is a positive correlation between of them, and co-expression of PLD2 and survivin has a positive correlation with the clinicpatholic features including tumor size, TNM stage, and lymph node metastasis. We also found that hypoxia induced the activity of PLD increased significant mainly caused by PLD2 in colon cancer cells. However, inhibition the activity of PLD2 induced by hypoxia promotes the apoptosis of human colon cancer cells, as well as decreased the expression of apoptosis markers including survivin and bcl2. Moreover, the pharmacological inhibition of PI3K/AKT supported the hypothesis that promotes the apoptosis of hypoxic colon cancer cells by PLD2 activity inhibition may through inactivation of the PI3K/AKT signaling pathway. Furthermore, interference the PLD2 gene expression leaded to the apoptosis of hypoxic colon cancer cells increased and also decreased the expression level of survivin and bcl2 may through inactivation of PI3K/AKT signaling pathway. These results indicated that PLD2 play antiapoptotic role in colon cancer under hypoxic conditions, inhibition of the activity, or interference of PLD2 gene expression will benefit for the treatment of colon cancer patients.

  6. Overexpression of FABP3 inhibits human bone marrow derived mesenchymal stem cell proliferation but enhances their survival in hypoxia

    Wang, Suna; Zhou, Yifu; Andreyev, Oleg; Hoyt, Robert F.; Singh, Avneesh; Hunt, Timothy; Horvath, Keith A.

    2014-01-01

    Studying the proliferative ability of human bone marrow derived mesenchymal stem cells in hypoxic conditions can help us achieve the effective regeneration of ischemic injured myocardium. Cardiac-type fatty acid binding protein (FABP3) is a specific biomarker of muscle and heart tissue injury. This protein is purported to be involved in early myocardial development, adult myocardial tissue repair and responsible for the modulation of cell growth and proliferation. We have investigated the role of FABP3 in human bone marrow derived mesenchymal stem cells under ischemic conditions. MSCs from 12 donors were cultured either in standard normoxic or modified hypoxic conditions, and the differential expression of FABP3 was tested by quantitative RT PCR and western blot. We also established stable FABP3 expression in MSCs and searched for variation in cellular proliferation and differentiation bioprocesses affected by hypoxic conditions. We identified: (1) the FABP3 differential expression pattern in the MSCs under hypoxic conditions; (2) over-expression of FABP3 inhibited the growth and proliferation of the MSCs; however, improved their survival in low oxygen environments; (3) the cell growth factors and positive cell cycle regulation genes, such as PCNA, APC, CCNB1, CCNB2 and CDC6 were all down-regulated; while the key negative cell cycle regulation genes TP53, BRCA1, CASP3 and CDKN1A were significantly up-regulated in the cells with FABP3 overexpression. Our data suggested that FABP3 was up-regulated under hypoxia; also negatively regulated the cell metabolic process and the mitotic cell cycle. Overexpression of FABP3 inhibited cell growth and proliferation via negative regulation of the cell cycle and down-regulation of cell growth factors, but enhances cell survival in hypoxic or ischemic conditions. - Highlights: • FABP3 expression pattern was studied in 12 human hypoxic-MSCs. • FABP3 mRNA and proteins are upregulated in the MSCs under hypoxic conditions.

  7. Endogenous α-crystallin inhibits expression of caspase-3 induced by hypoxia in retinal neurons.

    Ying, Xi; Peng, Yanli; Zhang, Jiaping; Wang, Xingli; Wu, Nan; Zeng, Yuxiao; Wang, Yi

    2014-08-28

    To investigate the expression of endogenous, hypoxic stress-induced α-crystallin and caspase-3 in rat retinal neurons in vitro. Retinal neurons were cultured from Long-Evans rats. The expression of endogenous α-crystallin was analyzed by immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR). Furthermore, hypoxic exposure was performed in cultured cells, and the expression of endogenous α-crystallin and caspase-3 was assayed by Western blotting. Positive α-crystallin staining was observed in cultured retinal neurons, and expression of endogenous α-crystallin mRNA peaked 3-5d after inoculation (Pendogenous, hypoxic stress-induced α-crystallin expression increased gradually, peaking 6h after hypoxia. The expression was more abundant compared to the control (Pendogenous α-crystallin in retinal neurons, especially over-expression induced by hypoxic stress, results in the down regulation of caspase-3. The data suggest that endogenous α-crystallin may act as an endogenous neuroprotective factor in retinal neurons. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Antioxidants inhibit the inflammatory and apoptotic processes in an intermittent hypoxia model of sleep apnea.

    da Rosa, Darlan Pase; Forgiarini, Luiz Felipe; e Silva, Mariel Barbachan; Fiori, Cíntia Zappe; Andrade, Cristiano Feijó; Martinez, Dênis; Marroni, Norma Possa

    2015-01-01

    Sleep apnea causes intermittent hypoxia (IH). We aimed to investigate the proteins related to oxidative stress, inflammation and apoptosis in liver tissue subjected to IH as a simulation of sleep apnea in conjunction with the administration of either melatonin (MEL, 200 μL/kg) or N-acetylcysteine (NAC, 10 mg/kg). Seventy-two adult male Balb-C mice were divided: simulation of IH (SIH), SIH + MEL, SIH + NAC, IH, IH + MEL and IH + NAC. The animals were subjected to simulations of sleep apnea for 8 h a day for 35 days. The data were analyzed with ANOVA and Tukey tests with the significance set at p < 0.05. In IH, there was a significant increase in oxidative stress and expression of HIF-1a. In addition, we observed increase in the activation levels of NF-kB. This increase may be responsible for the increased expression of TNF-alpha and iNOS as well as the significant increase of VEGF signaling and expression of caspase-3 and caspase-6, which suggests an increase in apoptosis. In the groups treated with antioxidants, the analysis showed that the enzyme activity and protein levels were similar to those of the non-simulated group. Thus, we show that IH causes liver inflammation and apoptosis, which may be protected with either MEL or NAC.

  9. Depletion of Treg cells inhibits minimal residual disease after surgery of HPV16-associated tumours

    Šímová, Jana; Bubeník, Jan; Bieblová, Jana; Rosalia, Rodney Alexander; Frič, Jan; Reiniš, Milan

    2006-01-01

    Roč. 29, č. 6 (2006), s. 1567-1571 ISSN 1019-6439 R&D Projects: GA ČR(CZ) GA301/04/0492 EU Projects: European Commission(XE) 18933 - CLINIGENE Grant - others:Liga proti rakovině(CZ) XX Institutional research plan: CEZ:AV0Z50520514 Keywords : HPV 16 * residual tumour disease * Treg cells Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.556, year: 2006

  10. Minocycline and doxycycline, but not other tetracycline-derived compounds, protect liver cells from chemical hypoxia and ischemia/reperfusion injury by inhibition of the mitochondrial calcium uniporter

    Schwartz, Justin; Holmuhamedov, Ekhson; Zhang, Xun; Lovelace, Gregory L.; Smith, Charles D.; Lemasters, John J.

    2013-01-01

    Minocycline, a tetracycline-derived compound, mitigates damage caused by ischemia/reperfusion (I/R) injury. Here, 19 tetracycline-derived compounds were screened in comparison to minocycline for their ability to protect hepatocytes against damage from chemical hypoxia and I/R injury. Cultured rat hepatocytes were incubated with 50 μM of each tetracycline-derived compound 20 min prior to exposure to 500 μM iodoacetic acid plus 1 mM KCN (chemical hypoxia). In other experiments, hepatocytes were incubated in anoxic Krebs–Ringer–HEPES buffer at pH 6.2 for 4 h prior to reoxygenation at pH 7.4 (simulated I/R). Tetracycline-derived compounds were added 20 min prior to reperfusion. Ca 2+ uptake was measured in isolated rat liver mitochondria incubated with Fluo-5N. Cell killing after 120 min of chemical hypoxia measured by propidium iodide (PI) fluorometry was 87%, which decreased to 28% and 42% with minocycline and doxycycline, respectively. After I/R, cell killing at 120 min decreased from 79% with vehicle to 43% and 49% with minocycline and doxycycline. No other tested compound decreased killing. Minocycline and doxycycline also inhibited mitochondrial Ca 2+ uptake and suppressed the Ca 2+ -induced mitochondrial permeability transition (MPT), the penultimate cause of cell death in reperfusion injury. Ru360, a specific inhibitor of the mitochondrial calcium uniporter (MCU), also decreased cell killing after hypoxia and I/R and blocked mitochondrial Ca 2+ uptake and the MPT. Other proposed mechanisms, including mitochondrial depolarization and matrix metalloprotease inhibition, could not account for cytoprotection. Taken together, these results indicate that minocycline and doxycycline are cytoprotective by way of inhibition of MCU. - Highlights: • Minocycline and doxycycline are the only cytoprotective tetracyclines of those tested • Cytoprotective tetracyclines inhibit the MPT and mitochondrial calcium and iron uptake. • Cytoprotective tetracyclines protect

  11. Minocycline and doxycycline, but not other tetracycline-derived compounds, protect liver cells from chemical hypoxia and ischemia/reperfusion injury by inhibition of the mitochondrial calcium uniporter

    Schwartz, Justin; Holmuhamedov, Ekhson; Zhang, Xun; Lovelace, Gregory L.; Smith, Charles D. [Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC (United States); Lemasters, John J., E-mail: JJLemasters@musc.edu [Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC (United States); Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC (United States)

    2013-11-15

    Minocycline, a tetracycline-derived compound, mitigates damage caused by ischemia/reperfusion (I/R) injury. Here, 19 tetracycline-derived compounds were screened in comparison to minocycline for their ability to protect hepatocytes against damage from chemical hypoxia and I/R injury. Cultured rat hepatocytes were incubated with 50 μM of each tetracycline-derived compound 20 min prior to exposure to 500 μM iodoacetic acid plus 1 mM KCN (chemical hypoxia). In other experiments, hepatocytes were incubated in anoxic Krebs–Ringer–HEPES buffer at pH 6.2 for 4 h prior to reoxygenation at pH 7.4 (simulated I/R). Tetracycline-derived compounds were added 20 min prior to reperfusion. Ca{sup 2+} uptake was measured in isolated rat liver mitochondria incubated with Fluo-5N. Cell killing after 120 min of chemical hypoxia measured by propidium iodide (PI) fluorometry was 87%, which decreased to 28% and 42% with minocycline and doxycycline, respectively. After I/R, cell killing at 120 min decreased from 79% with vehicle to 43% and 49% with minocycline and doxycycline. No other tested compound decreased killing. Minocycline and doxycycline also inhibited mitochondrial Ca{sup 2+} uptake and suppressed the Ca{sup 2+}-induced mitochondrial permeability transition (MPT), the penultimate cause of cell death in reperfusion injury. Ru360, a specific inhibitor of the mitochondrial calcium uniporter (MCU), also decreased cell killing after hypoxia and I/R and blocked mitochondrial Ca{sup 2+} uptake and the MPT. Other proposed mechanisms, including mitochondrial depolarization and matrix metalloprotease inhibition, could not account for cytoprotection. Taken together, these results indicate that minocycline and doxycycline are cytoprotective by way of inhibition of MCU. - Highlights: • Minocycline and doxycycline are the only cytoprotective tetracyclines of those tested • Cytoprotective tetracyclines inhibit the MPT and mitochondrial calcium and iron uptake. • Cytoprotective

  12. Tetraspanin 7 (TSPAN7) expression is upregulated in multiple myeloma patients and inhibits myeloma tumour development in vivo

    Cheong, Chee Man [Myeloma Research Laboratory, School of Medical Sciences, University of Adelaide, and South Australian Health and Medical Research Institute (SAHMRI), Adelaide 5000, SA (Australia); Chow, Annie W.S. [Myeloma Research Laboratory, School of Medical Sciences, University of Adelaide, and South Australian Health and Medical Research Institute (SAHMRI), Adelaide 5000, SA (Australia); Department of Haematology, SA Pathology, Adelaide 5000, SA (Australia); Fitter, Stephen [Myeloma Research Laboratory, School of Medical Sciences, University of Adelaide, and South Australian Health and Medical Research Institute (SAHMRI), Adelaide 5000, SA (Australia); Hewett, Duncan R. [Myeloma Research Laboratory, School of Medical Sciences, University of Adelaide, and South Australian Health and Medical Research Institute (SAHMRI), Adelaide 5000, SA (Australia); School of Medicine, University of Adelaide, Adelaide 5005, SA (Australia); Martin, Sally K. [Myeloma Research Laboratory, School of Medical Sciences, University of Adelaide, and South Australian Health and Medical Research Institute (SAHMRI), Adelaide 5000, SA (Australia); Department of Haematology, SA Pathology, Adelaide 5000, SA (Australia); School of Medicine, University of Adelaide, Adelaide 5005, SA (Australia); Williams, Sharon A. [Myeloma Research Laboratory, School of Medical Sciences, University of Adelaide, and South Australian Health and Medical Research Institute (SAHMRI), Adelaide 5000, SA (Australia); To, L. Bik [Department of Haematology, SA Pathology, Adelaide 5000, SA (Australia); and others

    2015-03-01

    Background: Increased expression of the tetraspanin TSPAN7 has been observed in a number of cancers; however, it is unclear how TSPAN7 plays a role in cancer progression. Methods: We investigated the expression of TSPAN7 in the haematological malignancy multiple myleoma (MM) and assessed the consequences of TSPAN7 expression in the adhesion, migration and growth of MM plasma cells (PC) in vitro and in bone marrow (BM) homing and tumour growth in vivo. Finally, we characterised the association of TSPAN7 with cell surface partner molecules in vitro. Results: TSPAN7 was found to be highly expressed at the RNA and protein level in CD138{sup +} MM PC from approximately 50% of MM patients. TSPAN7 overexpression in the murine myeloma cell line 5TGM1 significantly reduced tumour burden in 5TGM1/KaLwRij mice 4 weeks after intravenous adminstration of 5TGM1 cells. While TSPAN7 overexpression did not affect cell proliferation in vitro, TSPAN7 increased 5TGM1 cell adhesion to BM stromal cells and transendothelial migration. In addition, TSPAN7 was found to associate with the molecular chaperone calnexin on the cell surface. Conclusion: These results suggest that elevated TSPAN7 may be associated with better outcomes for up to 50% of MM patients. - Highlights: • TSPAN7 expression is upregulated in newly-diagnosed patients with active multiple myeloma. • Overexpression of TSPAN7 inhibits myeloma tumour development in vivo. • TSPAN7 interacts with calnexin at the plasma membrane in a myeloma cell line.

  13. Inhibition of Vascular Endothelial Growth Factor A and Hypoxia-Inducible Factor 1α Maximizes the Effects of Radiation in Sarcoma Mouse Models Through Destruction of Tumor Vasculature

    Lee, Hae-June; Yoon, Changhwan; Park, Do Joong; Kim, Yeo-Jung; Schmidt, Benjamin; Lee, Yoon-Jin; Tap, William D.; Eisinger-Mathason, T.S. Karin; Choy, Edwin; Kirsch, David G.; Simon, M. Celeste

    2015-01-01

    Purpose: To examine the addition of genetic or pharmacologic inhibition of hypoxia-inducible factor 1α (HIF-1α) to radiation therapy (RT) and vascular endothelial growth factor A (VEGF-A) inhibition (ie trimodality therapy) for soft-tissue sarcoma. Methods and Materials: Hypoxia-inducible factor 1α was inhibited using short hairpin RNA or low metronomic doses of doxorubicin, which blocks HIF-1α binding to DNA. Trimodality therapy was examined in a mouse xenograft model and a genetically engineered mouse model of sarcoma, as well as in vitro in tumor endothelial cells (ECs) and 4 sarcoma cell lines. Results: In both mouse models, any monotherapy or bimodality therapy resulted in tumor growth beyond 250 mm 3 within the 12-day treatment period, but trimodality therapy with RT, VEGF-A inhibition, and HIF-1α inhibition kept tumors at <250 mm 3 for up to 30 days. Trimodality therapy on tumors reduced HIF-1α activity as measured by expression of nuclear HIF-1α by 87% to 95% compared with RT alone, and cytoplasmic carbonic anhydrase 9 by 79% to 82%. Trimodality therapy also increased EC-specific apoptosis 2- to 4-fold more than RT alone and reduced microvessel density by 75% to 82%. When tumor ECs were treated in vitro with trimodality therapy under hypoxia, there were significant decreases in proliferation and colony formation and increases in DNA damage (as measured by Comet assay and γH2AX expression) and apoptosis (as measured by cleaved caspase 3 expression). Trimodality therapy had much less pronounced effects when 4 sarcoma cell lines were examined in these same assays. Conclusions: Inhibition of HIF-1α is highly effective when combined with RT and VEGF-A inhibition in blocking sarcoma growth by maximizing DNA damage and apoptosis in tumor ECs, leading to loss of tumor vasculature

  14. Inhibition of Vascular Endothelial Growth Factor A and Hypoxia-Inducible Factor 1α Maximizes the Effects of Radiation in Sarcoma Mouse Models Through Destruction of Tumor Vasculature

    Lee, Hae-June [Department of Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); Division of Radiation Effects, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Yoon, Changhwan [Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Park, Do Joong [Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Department of Surgery, Seoul National University Bundang Hospital, Sungnam (Korea, Republic of); Kim, Yeo-Jung [Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania (United States); Schmidt, Benjamin [Department of Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); Lee, Yoon-Jin [Department of Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); Division of Radiation Effects, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Tap, William D. [Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Eisinger-Mathason, T.S. Karin [Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania (United States); Choy, Edwin [Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); Kirsch, David G. [Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Simon, M. Celeste [Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania (United States); Howard Hughes Medical Institute (United States); and others

    2015-03-01

    Purpose: To examine the addition of genetic or pharmacologic inhibition of hypoxia-inducible factor 1α (HIF-1α) to radiation therapy (RT) and vascular endothelial growth factor A (VEGF-A) inhibition (ie trimodality therapy) for soft-tissue sarcoma. Methods and Materials: Hypoxia-inducible factor 1α was inhibited using short hairpin RNA or low metronomic doses of doxorubicin, which blocks HIF-1α binding to DNA. Trimodality therapy was examined in a mouse xenograft model and a genetically engineered mouse model of sarcoma, as well as in vitro in tumor endothelial cells (ECs) and 4 sarcoma cell lines. Results: In both mouse models, any monotherapy or bimodality therapy resulted in tumor growth beyond 250 mm{sup 3} within the 12-day treatment period, but trimodality therapy with RT, VEGF-A inhibition, and HIF-1α inhibition kept tumors at <250 mm{sup 3} for up to 30 days. Trimodality therapy on tumors reduced HIF-1α activity as measured by expression of nuclear HIF-1α by 87% to 95% compared with RT alone, and cytoplasmic carbonic anhydrase 9 by 79% to 82%. Trimodality therapy also increased EC-specific apoptosis 2- to 4-fold more than RT alone and reduced microvessel density by 75% to 82%. When tumor ECs were treated in vitro with trimodality therapy under hypoxia, there were significant decreases in proliferation and colony formation and increases in DNA damage (as measured by Comet assay and γH2AX expression) and apoptosis (as measured by cleaved caspase 3 expression). Trimodality therapy had much less pronounced effects when 4 sarcoma cell lines were examined in these same assays. Conclusions: Inhibition of HIF-1α is highly effective when combined with RT and VEGF-A inhibition in blocking sarcoma growth by maximizing DNA damage and apoptosis in tumor ECs, leading to loss of tumor vasculature.

  15. IGF-1 attenuates hypoxia-induced atrophy but inhibits myoglobin expression in C2C12 skeletal muscle myotubes

    Peters, Eva L.; van der Linde, Sandra M.; Vogel, Ilse S.P.; Haroon, Mohammad; Offringa, Carla; de Wit, Gerard M.J.; Koolwijk, Pieter; van der Laarse, Willem J.; Jaspers, Richard T.

    2017-01-01

    Chronic hypoxia is associated with muscle wasting and decreased oxidative capacity. By contrast, training under hypoxia may enhance hypertrophy and increase oxidative capacity as well as oxygen transport to the mitochondria, by increasing myoglobin (Mb) expression. The latter may be a feasible

  16. The novel hypoxic cytotoxin, TX-2098 has antitumor effect in pancreatic cancer; possible mechanism through inhibiting VEGF and hypoxia inducible factor-1α targeted gene expression.

    Miyake, Kotaro; Nishioka, Masanori; Imura, Satoru; Batmunkh, Erdenebulgan; Uto, Yoshihiro; Nagasawa, Hideko; Hori, Hitoshi; Shimada, Mitsuo

    2012-08-01

    Tumor hypoxia has been considered to be a potential therapeutic target, because hypoxia is a common feature of solid tumors and is associated with their malignant phenotype. In the present study, we investigated the antitumor effect of a novel hypoxic cytotoxin, 3-[2-hydroxyethyl(methyl)amino]-2-quinoxalinecarbonitrile 1,4-dioxide (TX-2098) in inhibiting the expression of hypoxia inducible factor-1α (HIF-1α), and consequently vascular endothelial cell growth factor (VEGF) expression in pancreatic cancer. The antitumor effects of TX-2098 under hypoxia were tested against various human pancreatic cancer cell lines using WST-8 assay. VEGF protein induced pancreatic cancer was determined on cell-free supernatant by ELISA. Moreover, nude mice bearing subcutaneously (s.c.) or orthotopically implanted human SUIT-2 were treated with TX-2098. Tumor volume, survival and expression of HIF-1 and associated molecules were evaluated in treatment versus control groups. In vitro, TX-2098 inhibited the proliferation of various pancreatic cancer cell lines. In s.c model, tumors from nude mice injected with pancreatic cancer cells and treated with TX-2098 showed significant reductions in volume (P<0.01 versus control). Quantitative real-time reverse transcription-PCR analysis revealed that TX-2098 significantly inhibited mRNA expression of the HIF-1 associated molecules, VEGF, glucose transporter 1 and Aldolase A (P<0.01 versus control). These treatments also prolong the survival in orthotopic models. These results suggest that the effect of TX-2098 in pancreatic cancer might be correlated with the expression of VEGF and HIF-1 targeted molecules. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Delivery of small interfering RNA for inhibition of endothelial cell apoptosis by hypoxia and serum deprivation

    Cho, Seung-Woo; Hartle, Lauren; Son, Sun Mi; Yang, Fan; Goldberg, Michael; Xu, Qiaobing; Langer, Robert; Anderson, Daniel G.

    2008-01-01

    RNA interference (RNAi) for anti-angiogenic or pro-apoptotic factors in endothelial cells (ECs) has great potential for the treatment of ischemic diseases by promoting angiogenesis or inhibiting apoptosis. Here, we report the utility of small interfering RNA (siRNA) in inhibiting EC apoptosis induced by tumor necrosis factor-α (TNF-α). siRNA was designed and synthesized targeting tumor necrosis factor-α receptor-1 (TNFR-1) and Src homology 2 domain-containing protein tyrosine phosphatase-1 (SHP-1). Human umbilical vein endothelial cells (HUVECs) were cultured under in vitro hypoxic and serum-deprived conditions to simulate in vivo ischemic conditions. Two days after liposomal delivery of siRNA targeting TNFR-1 and SHP-1, significant silencing of each target (TNFR-1; 76.5% and SHP-1; 97.2%) was detected. Under serum-deprived hypoxic (1% oxygen) conditions, TNF-α expression in HUVECs increased relative to normoxic (20% oxygen) and serum-containing conditions. Despite enhanced TNF-α expression, suppression of TNFR-1 or SHP-1 by siRNA delivery not only enhanced expression of angiogenic factors (KDR/Flk-1 and eNOS) and anti-apoptotic factor (Bcl-xL) but also reduced expression of a pro-apoptotic factor (Bax). Transfection of TNFR-1 or SHP-1 siRNA significantly decreased the HUVEC apoptosis while significantly enhancing HUVEC proliferation and capillary formation. The present study demonstrates that TNFR-1 and SHP-1 may be useful targets for the treatment of myocardial or hindlimb ischemia

  18. Hypoxic stress simultaneously stimulates vascular endothelial growth factor via hypoxia-inducible factor-1α and inhibits stromal cell-derived factor-1 in human endometrial stromal cells.

    Tsuzuki, Tomoko; Okada, Hidetaka; Cho, Hisayuu; Tsuji, Shoko; Nishigaki, Akemi; Yasuda, Katsuhiko; Kanzaki, Hideharu

    2012-02-01

    Hypoxia of the human endometrium is a physiologic event occurring during the perimenstrual period and the local stimulus for angiogenesis. The aim of this study was to investigate the effects of hypoxic stress on the regulation of vascular endothelial growth factor (VEGF) and stromal cell-derived factor-1 (SDF-1/CXCL12), and the potential role of hypoxia-inducible factor-1α (HIF-1α) in the endometrium. Human endometrial stromal cells (ESCs, n= 22 samples) were studied in vitro. ESCs were cultured under hypoxic and normoxic conditions and treated with cobalt chloride (CoCl₂; a hypoxia-mimicking agent) and/or echinomycin, a small-molecule inhibitor of HIF-1α activity. The mRNA levels and production of VEGF and SDF-1 were assessed by real-time PCR and ELISA, respectively. The HIF-1α protein levels were measured using western blot analysis. Hypoxia simultaneously induced the expression of mRNA and production of VEGF and attenuated the expression and production of SDF-1 from ESCs in a time-dependent manner. Similar changes were observed in the ESCs after stimulation with CoCl₂ in a dose-dependent manner. CoCl₂ significantly induced the expression of HIF-1α protein, and its highest expression was observed at 6 h. Echinomycin inhibited hypoxia-induced VEGF production without affecting the HIF-1α protein level and cell toxicity and had no effect on SDF-1 secretion (P hypoxic conditions that could influence angiogenesis in the human endometrium.

  19. Stimulating retinal blood vessel protection with hypoxia-inducible factor stabilization: identification of novel small-molecule hydrazones to inhibit hypoxia-inducible factor prolyl hydroxylase (an American Ophthalmological Society thesis).

    Sears, Jonathan E; Hoppe, George

    2013-09-01

    To discover novel small molecules that inhibit hypoxia-inducible factor (HIF) prolyl hydroxylase (PHD), a key enzyme that regulates the posttranslational stability and hence activity of HIF. NIH3T3 cell line stably transfected with firefly luciferase under a HIF-1-inducible promoter was used to screen a Chembridge library of 34,000 small molecules of molecular weight 250 to 550 Da. Positive hits were considered at 4.5-fold higher luminescence than control. Selected compounds were validated in vitro. The most effective dose was then used to treat mice expressing firefly luciferase fused to the oxygen-dependent degradation domain (lucODD) in order to determine the location of the receptor for systemic treatment with small-molecule HIF PHD inhibitors. Twenty-three novel small molecules were discovered, the majority of which were hydrazones and hydrazines. Of the 23 compounds, each had different selectivity for expression of erythropoietin or vascular endothelial growth factor, two angiogenic, HIF-regulated gene products. In addition, each showed different selectivity for hepatocytes or kidney, or both or neither, when injected intraperitoneally in an in vivo reporter gene assay. The discovery of multiple small molecules that inhibit HIF PHD identifies new reagents to develop strategies to prevent the degradation of HIF by its selective PHD. These molecules are novel hypoxia mimetics that may provide new strategies to protect retinovasculature from hyperoxia.

  20. Angiotensin-(1–7 inhibits inflammation and oxidative stress to relieve lung injury induced by chronic intermittent hypoxia in rats

    W. Lu

    2016-01-01

    Full Text Available Obstructive sleep apnea is associated with inflammation and oxidative stress in lung tissues and can lead to metabolic abnormalities. We investigated the effects of angiotensin1–7 [Ang-(1–7] on lung injury in rats induced by chronic intermittent hypoxia (CIH. We randomly assigned 32 male Sprague-Dawley rats (180–200 g to normoxia control (NC, CIH-untreated (uCIH, Ang-(1–7-treated normoxia control (N-A, and Ang-(1–7-treated CIH (CIH-A groups. Oxidative stress biomarkers were measured in lung tissues, and expression of NADPH oxidase 4 (Nox4 and Nox subunits (p22phox, and p47phox was determined by Western blot and reverse transcription-polymerase chain reaction. Pulmonary pathological changes were more evident in the uCIH group than in the other groups. Enzyme-linked immunosorbent assays and immunohistochemical staining showed that inflammatory factor concentrations in serum and lung tissues in the uCIH group were significantly higher than those in the NC and N-A groups. Expression of inflammatory factors was significantly higher in the CIH-A group than in the NC and N-A groups, but was lower than in the uCIH group (P<0.01. Oxidative stress was markedly higher in the uCIH group than in the NC and N-A groups. Expression of Nox4 and its subunits was also increased in the uCIH group. These changes were attenuated upon Ang-(1–7 treatment. In summary, treatment with Ang-(1-7 reversed signs of CIH-induced lung injury via inhibition of inflammation and oxidative stress.

  1. PACAP and VIP inhibit the invasiveness of glioblastoma cells exposed to hypoxia through the regulation of HIFs and EGFR expression

    Grazia eMaugeri; Agata Grazia eD'Amico; Agata Grazia eD'Amico; Rita eReitano; Gaetano eMagro; Sebastiano eCavallaro; Salvatore eSalomone; Velia eD'Agata

    2016-01-01

    Pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal peptide (VIP) through the binding of vasoactive intestinal peptide receptors (VIPRs), perform a wide variety of effects in human cancers, including glioblastoma multiforme (GBM). This tumor is characterized by extensive areas of hypoxia, which triggers the expression of hypoxia-inducible factors (HIFs). HIFs not only mediate angiogenesis but also tumor cell migration and invasion. Furthermore, HIFs activation...

  2. Hydrogen sulfide protects against chemical hypoxia-induced injury by inhibiting ROS-activated ERK1/2 and p38MAPK signaling pathways in PC12 cells.

    Aiping Lan

    Full Text Available Hydrogen sulfide (H(2S has been proposed as a novel neuromodulator and neuroprotective agent. Cobalt chloride (CoCl(2 is a well-known hypoxia mimetic agent. We have demonstrated that H(2S protects against CoCl(2-induced injuries in PC12 cells. However, whether the members of mitogen-activated protein kinases (MAPK, in particular, extracellular signal-regulated kinase1/2(ERK1/2 and p38MAPK are involved in the neuroprotection of H(2S against chemical hypoxia-induced injuries of PC12 cells is not understood. We observed that CoCl(2 induced expression of transcriptional factor hypoxia-inducible factor-1 alpha (HIF-1α, decreased cystathionine-β synthase (CBS, a synthase of H(2S expression, and increased generation of reactive oxygen species (ROS, leading to injuries of the cells, evidenced by decrease in cell viability, dissipation of mitochondrial membrane potential (MMP , caspase-3 activation and apoptosis, which were attenuated by pretreatment with NaHS (a donor of H(2S or N-acetyl-L cystein (NAC, a ROS scavenger. CoCl(2 rapidly activated ERK1/2, p38MAPK and C-Jun N-terminal kinase (JNK. Inhibition of ERK1/2 or p38MAPK or JNK with kinase inhibitors (U0126 or SB203580 or SP600125, respectively or genetic silencing of ERK1/2 or p38MAPK by RNAi (Si-ERK1/2 or Si-p38MAPK significantly prevented CoCl(2-induced injuries. Pretreatment with NaHS or NAC inhibited not only CoCl(2-induced ROS production, but also phosphorylation of ERK1/2 and p38MAPK. Thus, we demonstrated that a concurrent activation of ERK1/2, p38MAPK and JNK participates in CoCl(2-induced injuries and that H(2S protects PC12 cells against chemical hypoxia-induced injuries by inhibition of ROS-activated ERK1/2 and p38MAPK pathways. Our results suggest that inhibitors of ERK1/2, p38MAPK and JNK or antioxidants may be useful for preventing and treating hypoxia-induced neuronal injury.

  3. Nicotinamide and other benzamide analogs as agents for overcoming hypoxic cell radiation resistance in tumours

    Horsman, M.

    1996-01-01

    Oxygen deficient hypoxic cells, which are resistant to sparsely ionising radiation, have now been identified in most animal and some human solid tumours and will influence the response of those tumours to radiation treatment. This hypoxia can be either chronic, arising from an oxygen diffusion limitation, or acute, resulting from transient stoppages in microregional blood flow. Extensive experimental studies, especially in the last decade, have shown that nicotinamide and structurally related analogs can effectively sensitize murine tumours to both single and fractionated radiation treatments and that they do so in preference to the effects seen in mouse normal tissues. The earliest studies suggested that this enhancement of radiation damage was the result of an inhibition of the repair mechanisms. However, recent studies in mouse tumours have shown that these drugs prevent transient cessations in blood flow, thus inhibiting the development of acute hypoxia. This novel discovery led to the suggestion that the potential role of these agents as radiosensitizers would be when combined with treatments that overcame chronic hypoxia. The combined nicotinamide with hyperthermia proved that the enhancement of radiation damage by both agents together was greater than that seen with each agent alone. Similar results were later seen for nicotinamide combined with a perfluorochemical emulsion, carbogen breathing, and pentoxifylline, and in all these studies the effects in tumours were always greater than those seen in appropriate normal tissues. Of all the analogs, it is nicotinamide itself which has been the most extensively studied as a radiosensitizer in vivo and the one that shows the greatest effect in animal tumours. It is also an agent that has been well established clinically, with daily doses of up to 6 g, associated with a low incidence of side effects. This human dose is equivalent to 100-200 mg/kg in mice and such doses will maximally sensitize murine tumours to

  4. The novel hypoxic cytotoxin, TX-2098 has antitumor effect in pancreatic cancer; possible mechanism through inhibiting VEGF and hypoxia inducible factor-1{alpha} targeted gene expression

    Miyake, Kotaro, E-mail: hif.panc@gmail.com [Department of Surgery, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770-8503 (Japan); Nishioka, Masanori; Imura, Satoru; Batmunkh, Erdenebulgan [Department of Surgery, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770-8503 (Japan); Uto, Yoshihiro [Department of Biological Science and Technology, Institute of Socio Technosciences, The University of Tokushima Graduate School, Tokushima 770-8503 (Japan); Nagasawa, Hideko [Laboratory of Pharmaceutical and Medicinal Chemistry, Gifu Pharmaceutical University, Gifu 501-1196 (Japan); Hori, Hitoshi [Department of Biological Science and Technology, Institute of Socio Technosciences, The University of Tokushima Graduate School, Tokushima 770-8503 (Japan); Shimada, Mitsuo [Department of Surgery, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770-8503 (Japan)

    2012-08-01

    Tumor hypoxia has been considered to be a potential therapeutic target, because hypoxia is a common feature of solid tumors and is associated with their malignant phenotype. In the present study, we investigated the antitumor effect of a novel hypoxic cytotoxin, 3-[2-hydroxyethyl(methyl)amino]-2-quinoxalinecarbonitrile 1,4-dioxide (TX-2098) in inhibiting the expression of hypoxia inducible factor-1{alpha} (HIF-1{alpha}), and consequently vascular endothelial cell growth factor (VEGF) expression in pancreatic cancer. The antitumor effects of TX-2098 under hypoxia were tested against various human pancreatic cancer cell lines using WST-8 assay. VEGF protein induced pancreatic cancer was determined on cell-free supernatant by ELISA. Moreover, nude mice bearing subcutaneously (s.c.) or orthotopically implanted human SUIT-2 were treated with TX-2098. Tumor volume, survival and expression of HIF-1 and associated molecules were evaluated in treatment versus control groups. In vitro, TX-2098 inhibited the proliferation of various pancreatic cancer cell lines. In s.c model, tumors from nude mice injected with pancreatic cancer cells and treated with TX-2098 showed significant reductions in volume (P < 0.01 versus control). Quantitative real-time reverse transcription-PCR analysis revealed that TX-2098 significantly inhibited mRNA expression of the HIF-1 associated molecules, VEGF, glucose transporter 1 and Aldolase A (P < 0.01 versus control). These treatments also prolong the survival in orthotopic models. These results suggest that the effect of TX-2098 in pancreatic cancer might be correlated with the expression of VEGF and HIF-1 targeted molecules. -- Highlights: Black-Right-Pointing-Pointer We designed and synthesized novel hypoxic cytoxin, TX-2098. Black-Right-Pointing-Pointer TX-2098 inhibited the proliferation of human pancreatic cancer cells than TPZ. Black-Right-Pointing-Pointer TX-2098 reduced VEGF protein level than TPZ. Black-Right-Pointing-Pointer TX-2098

  5. The novel hypoxic cytotoxin, TX-2098 has antitumor effect in pancreatic cancer; possible mechanism through inhibiting VEGF and hypoxia inducible factor-1α targeted gene expression

    Miyake, Kotaro; Nishioka, Masanori; Imura, Satoru; Batmunkh, Erdenebulgan; Uto, Yoshihiro; Nagasawa, Hideko; Hori, Hitoshi; Shimada, Mitsuo

    2012-01-01

    Tumor hypoxia has been considered to be a potential therapeutic target, because hypoxia is a common feature of solid tumors and is associated with their malignant phenotype. In the present study, we investigated the antitumor effect of a novel hypoxic cytotoxin, 3-[2-hydroxyethyl(methyl)amino]-2-quinoxalinecarbonitrile 1,4-dioxide (TX-2098) in inhibiting the expression of hypoxia inducible factor-1α (HIF-1α), and consequently vascular endothelial cell growth factor (VEGF) expression in pancreatic cancer. The antitumor effects of TX-2098 under hypoxia were tested against various human pancreatic cancer cell lines using WST-8 assay. VEGF protein induced pancreatic cancer was determined on cell-free supernatant by ELISA. Moreover, nude mice bearing subcutaneously (s.c.) or orthotopically implanted human SUIT-2 were treated with TX-2098. Tumor volume, survival and expression of HIF-1 and associated molecules were evaluated in treatment versus control groups. In vitro, TX-2098 inhibited the proliferation of various pancreatic cancer cell lines. In s.c model, tumors from nude mice injected with pancreatic cancer cells and treated with TX-2098 showed significant reductions in volume (P < 0.01 versus control). Quantitative real-time reverse transcription-PCR analysis revealed that TX-2098 significantly inhibited mRNA expression of the HIF-1 associated molecules, VEGF, glucose transporter 1 and Aldolase A (P < 0.01 versus control). These treatments also prolong the survival in orthotopic models. These results suggest that the effect of TX-2098 in pancreatic cancer might be correlated with the expression of VEGF and HIF-1 targeted molecules. -- Highlights: ► We designed and synthesized novel hypoxic cytoxin, TX-2098. ► TX-2098 inhibited the proliferation of human pancreatic cancer cells than TPZ. ► TX-2098 reduced VEGF protein level than TPZ. ► TX-2098 inhibited mRNA expression of VEGF, GLUT1 and Aldolase A, not HIF-1α. ► TX-2098 improved the survival in

  6. Lobatin B inhibits NPM/ALK and NF-κB attenuating anaplastic-large-cell-lymphomagenesis and lymphendothelial tumour intravasation.

    Kiss, Izabella; Unger, Christine; Huu, Chi Nguyen; Atanasov, Atanas Georgiev; Kramer, Nina; Chatruphonprasert, Waranya; Brenner, Stefan; McKinnon, Ruxandra; Peschel, Andrea; Vasas, Andrea; Lajter, Ildiko; Kain, Renate; Saiko, Philipp; Szekeres, Thomas; Kenner, Lukas; Hassler, Melanie R; Diaz, Rene; Frisch, Richard; Dirsch, Verena M; Jäger, Walter; de Martin, Rainer; Bochkov, Valery N; Passreiter, Claus M; Peter-Vörösmarty, Barbara; Mader, Robert M; Grusch, Michael; Dolznig, Helmut; Kopp, Brigitte; Zupko, Istvan; Hohmann, Judit; Krupitza, Georg

    2015-01-28

    An apolar extract of the traditional medicinal plant Neurolaena lobata inhibited the expression of the NPM/ALK chimera, which is causal for the majority of anaplastic large cell lymphomas (ALCLs). Therefore, an active principle of the extract, the furanoheliangolide sesquiterpene lactone lobatin B, was isolated and tested regarding the inhibition of ALCL expansion and tumour cell intravasation through the lymphendothelium. ALCL cell lines, HL-60 cells and PBMCs were treated with plant compounds and the ALK inhibitor TAE-684 to measure mitochondrial activity, proliferation and cell cycle progression and to correlate the results with protein- and mRNA-expression of selected gene products. Several endpoints indicative for cell death were analysed after lobatin B treatment. Tumour cell intravasation through lymphendothelial monolayers was measured and potential causal mechanisms were investigated analysing NF-κB- and cytochrome P450 activity, and 12(S)-HETE production. Lobatin B inhibited the expression of NPM/ALK, JunB and PDGF-Rβ, and attenuated proliferation of ALCL cells by arresting them in late M phase. Mitochondrial activity remained largely unaffected upon lobatin B treatment. Nevertheless, caspase 3 became activated in ALCL cells. Also HL-60 cell proliferation was attenuated whereas PBMCs of healthy donors were not affected by lobatin B. Additionally, tumour cell intravasation, which partly depends on NF-κB, was significantly suppressed by lobatin B most likely due to its NF-κB-inhibitory property. Lobatin B, which was isolated from a plant used in ethnomedicine, targets malignant cells by at least two properties: I) inhibition of NPM/ALK, thereby providing high specificity in combating this most prevalent fusion protein occurring in ALCL; II) inhibition of NF-κB, thereby not affecting normal cells with low constitutive NF-κB activity. This property also inhibits tumour cell intravasation into the lymphatic system and may provide an option to manage this

  7. Chemical Activation of the Hypoxia-Inducible Factor Reversibly Reduces Tendon Stem Cell Proliferation, Inhibits Their Differentiation, and Maintains Cell Undifferentiation.

    Menon, Alessandra; Creo, Pasquale; Piccoli, Marco; Bergante, Sonia; Conforti, Erika; Banfi, Giuseppe; Randelli, Pietro; Anastasia, Luigi

    2018-01-01

    Adult stem cell-based therapeutic approaches for tissue regeneration have been proposed for several years. However, adult stem cells are usually limited in number and difficult to be expanded in vitro, and they usually tend to quickly lose their potency with passages, as they differentiate and become senescent. Culturing stem cells under reduced oxygen tensions (below 21%) has been proposed as a tool to increase cell proliferation, but many studies reported opposite effects. In particular, cell response to hypoxia seems to be very stem cell type specific. Nonetheless, it is clear that a major role in this process is played by the hypoxia inducible factor (HIF), the master regulator of cell response to oxygen deprivation, which affects cell metabolism and differentiation. Herein, we report that a chemical activation of HIF in human tendon stem cells reduces their proliferation and inhibits their differentiation in a reversible and dose-dependent manner. These results support the notion that hypoxia, by activating HIF, plays a crucial role in preserving stem cells in an undifferentiated state in the "hypoxic niches" present in the tissue in which they reside before migrating in more oxygenated areas to heal a damaged tissue.

  8. Chemical Activation of the Hypoxia-Inducible Factor Reversibly Reduces Tendon Stem Cell Proliferation, Inhibits Their Differentiation, and Maintains Cell Undifferentiation

    Alessandra Menon

    2018-01-01

    Full Text Available Adult stem cell-based therapeutic approaches for tissue regeneration have been proposed for several years. However, adult stem cells are usually limited in number and difficult to be expanded in vitro, and they usually tend to quickly lose their potency with passages, as they differentiate and become senescent. Culturing stem cells under reduced oxygen tensions (below 21% has been proposed as a tool to increase cell proliferation, but many studies reported opposite effects. In particular, cell response to hypoxia seems to be very stem cell type specific. Nonetheless, it is clear that a major role in this process is played by the hypoxia inducible factor (HIF, the master regulator of cell response to oxygen deprivation, which affects cell metabolism and differentiation. Herein, we report that a chemical activation of HIF in human tendon stem cells reduces their proliferation and inhibits their differentiation in a reversible and dose-dependent manner. These results support the notion that hypoxia, by activating HIF, plays a crucial role in preserving stem cells in an undifferentiated state in the “hypoxic niches” present in the tissue in which they reside before migrating in more oxygenated areas to heal a damaged tissue.

  9. Immunization with MHC class I-negative but not -positive HPV16-associated tumour cells inhibits growth of MHC class I-negative tumours

    Reiniš, Milan; Šímová, Jana; Indrová, Marie; Bieblová, Jana; Přibylová, Hana; Moravcová, Simona; Jandlová, Táňa; Bubeník, Jan

    2007-01-01

    Roč. 30, č. 4 (2007), s. 1011-1017 ISSN 1019-6439 R&D Projects: GA MZd NR7807 EU Projects: European Commission(XE) 18933 - CLINIGENE Grant - others:Liga proti rakovině, Praha(CZ) XX Institutional research plan: CEZ:AV0Z50520514 Keywords : HPV16 * MHC class I-deficient tumours * immunologic crossreaction Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.295, year: 2007

  10. Promising effects of xanthine oxidase inhibition by allopurinol on autonomic heart regulation estimated by heart rate variability (HRV analysis in rats exposed to hypoxia and hyperoxia.

    Stanisław Zajączkowski

    Full Text Available It has long been suggested that reactive oxygen species (ROS play a role in oxygen sensing via peripheral chemoreceptors, which would imply their involvement in chemoreflex activation and autonomic regulation of heart rate. We hypothesize that antioxidant affect neurogenic cardiovascular regulation through activation of chemoreflex which results in increased control of sympathetic mechanism regulating heart rhythm. Activity of xanthine oxidase (XO, which is among the major endogenous sources of ROS in the rat has been shown to increase during hypoxia promote oxidative stress. However, the mechanism of how XO inhibition affects neurogenic regulation of heart rhythm is still unclear.The study aimed to evaluate effects of allopurinol-driven inhibition of XO on autonomic heart regulation in rats exposed to hypoxia followed by hyperoxia, using heart rate variability (HRV analysis.16 conscious male Wistar rats (350 g: control-untreated (N = 8 and pretreated with Allopurinol-XO inhibitor (5 mg/kg, followed by 50 mg/kg, administered intraperitoneally (N = 8, were exposed to controlled hypobaric hypoxia (1h in order to activate chemoreflex. The treatment was followed by 1h hyperoxia (chemoreflex suppression. Time-series of 1024 RR-intervals were extracted from 4kHz ECG recording for heart rate variability (HRV analysis in order to calculate the following time-domain parameters: mean RR interval (RRi, SDNN (standard deviation of all normal NN intervals, rMSSD (square root of the mean of the squares of differences between adjacent NN intervals, frequency-domain parameters (FFT method: TSP (total spectral power as well as low and high frequency band powers (LF and HF. At the end of experiment we used rat plasma to evaluate enzymatic activity of XO and markers of oxidative stress: protein carbonyl group and 8-isoprostane concentrations. Enzymatic activity of superoxide dismutase (SOD, catalase (CAT and glutathione peroxidase (GPx were measures in erythrocyte

  11. Promising effects of xanthine oxidase inhibition by allopurinol on autonomic heart regulation estimated by heart rate variability (HRV) analysis in rats exposed to hypoxia and hyperoxia

    Ziółkowski, Wiesław; Badtke, Piotr; Zajączkowski, Miłosz A.; Flis, Damian J.; Figarski, Adam; Smolińska-Bylańska, Maria; Wierzba, Tomasz H.

    2018-01-01

    Background It has long been suggested that reactive oxygen species (ROS) play a role in oxygen sensing via peripheral chemoreceptors, which would imply their involvement in chemoreflex activation and autonomic regulation of heart rate. We hypothesize that antioxidant affect neurogenic cardiovascular regulation through activation of chemoreflex which results in increased control of sympathetic mechanism regulating heart rhythm. Activity of xanthine oxidase (XO), which is among the major endogenous sources of ROS in the rat has been shown to increase during hypoxia promote oxidative stress. However, the mechanism of how XO inhibition affects neurogenic regulation of heart rhythm is still unclear. Aim The study aimed to evaluate effects of allopurinol-driven inhibition of XO on autonomic heart regulation in rats exposed to hypoxia followed by hyperoxia, using heart rate variability (HRV) analysis. Material and methods 16 conscious male Wistar rats (350 g): control-untreated (N = 8) and pretreated with Allopurinol-XO inhibitor (5 mg/kg, followed by 50 mg/kg), administered intraperitoneally (N = 8), were exposed to controlled hypobaric hypoxia (1h) in order to activate chemoreflex. The treatment was followed by 1h hyperoxia (chemoreflex suppression). Time-series of 1024 RR-intervals were extracted from 4kHz ECG recording for heart rate variability (HRV) analysis in order to calculate the following time-domain parameters: mean RR interval (RRi), SDNN (standard deviation of all normal NN intervals), rMSSD (square root of the mean of the squares of differences between adjacent NN intervals), frequency-domain parameters (FFT method): TSP (total spectral power) as well as low and high frequency band powers (LF and HF). At the end of experiment we used rat plasma to evaluate enzymatic activity of XO and markers of oxidative stress: protein carbonyl group and 8-isoprostane concentrations. Enzymatic activity of superoxide dismutase (SOD), catalase (CAT) and glutathione

  12. FoxO3A promotes metabolic adaptation to hypoxia by antagonizing Myc function

    Jensen, Kim Steen; Binderup, Tina; Jensen, Klaus Thorleif

    2011-01-01

    Exposure of metazoan organisms to hypoxia engages a metabolic switch orchestrated by the hypoxia-inducible factor 1 (HIF-1). HIF-1 mediates induction of glycolysis and active repression of mitochondrial respiration that reduces oxygen consumption and inhibits the production of potentially harmful...... tumour tissue in vivo and that FoxO3A short-hairpin RNA (shRNA)-expressing xenograft tumours are decreased in size and metabolically changed. Our findings define a novel mechanism by which FoxO3A promotes metabolic adaptation and stress resistance in hypoxia....... reactive oxygen species (ROS). Here, we show that FoxO3A is activated in hypoxia downstream of HIF-1 and mediates the hypoxic repression of a set of nuclear-encoded mitochondrial genes. FoxO3A is required for hypoxic suppression of mitochondrial mass, oxygen consumption, and ROS production and promotes...... cell survival in hypoxia. FoxO3A is recruited to the promoters of nuclear-encoded mitochondrial genes where it directly antagonizes c-Myc function via a mechanism that does not require binding to the consensus FoxO recognition element. Furthermore, we show that FoxO3A is activated in human hypoxic...

  13. Adiponectin protects rat myocardium against chronic intermittent hypoxia-induced injury via inhibition of endoplasmic reticulum stress.

    Wenxiao Ding

    Full Text Available Obstructive sleep apnea syndrome (OSAS is associated with many cardiovascular disorders such as heart failure, hypertension, atherosclerosis, and arrhythmia and so on. Of the many associated factors, chronic intermittent hypoxia (CIH in particular is the primary player in OSAS. To assess the effects of CIH on cardiac function secondary to OSAS, we established a model to study the effects of CIH on Wistar rats. Specifically, we examined the possible underlying cellular mechanisms of hypoxic tissue damage and the possible protective role of adiponectin against hypoxic insults. In the first treatment group, rats were exposed to CIH conditions (nadir O2, 5-6% for 8 hours/day, for 5 weeks. Subsequent CIH-induced cardiac dysfunction was measured by echocardiograph. Compared with the normal control (NC group, rats in the CIH-exposed group experienced elevated levels of left ventricular end-systolic dimension and left ventricular end-systolic volume and depressed levels of left ventricular ejection fraction and left ventricular fractional shortening (p<0.05. However, when adiponectin (Ad was added in CIH + Ad group, we saw a rescue in the elevations of the aforementioned left ventricular function (p<0.05. To assess critical cardiac injury, we detected myocardial apoptosis by Terminal deoxynucleotidyl transfer-mediated dUTP nick end-labeling (TUNEL analysis. It was showed that the apoptosis percentage in CIH group (2.948% was significantly higher than that in NC group (0.4167% and CIH + Ad group (1.219% (p<0.05. Protein expressions of cleaved caspase-3, cleaved caspase-9, and cleaved-caspase-12 validated our TUNEL results (p<0.05. Mechanistically, our results demonstrated that the proteins expressed with endoplasmic reticulum stress and the expression of reactive oxygen species (ROS were significantly elevated under CIH conditions, whereas Ad supplementation partially decreased them. Overall, our results suggested that Ad augmentation could improve CIH

  14. Tocopherol in irradiation of temporary hypoxic tumours

    Kaagerud, A.; Lund, N.; Peterson, H.I.

    1981-01-01

    The influence of tocopherol on the effect of local irradiation under induced ischaemia by temporary tourniquet of two rat tumours transplanted intramuscularly into one hindleg was evaluated. An impaired retardation of growth rate occurred in tumours irradiated under ischaemia. This effect was eliminated by pretreatment of animals with tocopherol. In separate experiments the method of inducing ischaemia was investigated by MDO-electrode measurements of tumour tissue oxygen pressure. A significant tumour hypoxia was found under tourniquet of the tumour-bearing leg of the animals. Pretreatment with tocopherol did not influence the tumour pO 2 . (Auth.)

  15. Hypoxia Room

    Federal Laboratory Consortium — The Hypoxia Room is a 8x8x8 ft. clear vinyl plastic and aluminum frame construction enclosure located within USAREIM laboratory 028. The Hypoxia Room (manufactured...

  16. The stabilization of hypoxia inducible factor modulates differentiation status and inhibits the proliferation of mouse embryonic stem cells

    Binó, Lucia; Kučera, J.; Štefková, K.; Šindlerová, Lenka; Lanová, M.; Kudová, J.; Kubala, Lukáš; Pachernik, J.

    2016-01-01

    Roč. 244, JAN2016 (2016), s. 204-214 ISSN 0009-2797 R&D Projects: GA MŠk(CZ) EE2.3.30.0030 Institutional support: RVO:68081707 Keywords : Hypoxia * HIF-1 * Prolyl hydroxylase Subject RIV: BO - Biophysics Impact factor: 3.143, year: 2016

  17. Inhibition of hypoxia-associated response and kynurenine production in response to hyperbaric oxygen as mechanisms involved in protection against experimental cerebral malaria.

    Bastos, Marcele F; Kayano, Ana Carolina A V; Silva-Filho, João Luiz; Dos-Santos, João Conrado K; Judice, Carla; Blanco, Yara C; Shryock, Nathaniel; Sercundes, Michelle K; Ortolan, Luana S; Francelin, Carolina; Leite, Juliana A; Oliveira, Rafaella; Elias, Rosa M; Câmara, Niels O S; Lopes, Stefanie C P; Albrecht, Letusa; Farias, Alessandro S; Vicente, Cristina P; Werneck, Claudio C; Giorgio, Selma; Verinaud, Liana; Epiphanio, Sabrina; Marinho, Claudio R F; Lalwani, Pritesh; Amino, Rogerio; Aliberti, Julio; Costa, Fabio T M

    2018-03-20

    Cerebral malaria (CM) is a multifactorial syndrome involving an exacerbated proinflammatory status, endothelial cell activation, coagulopathy, hypoxia, and accumulation of leukocytes and parasites in the brain microvasculature. Despite significant improvements in malaria control, 15% of mortality is still observed in CM cases, and 25% of survivors develop neurologic sequelae for life-even after appropriate antimalarial therapy. A treatment that ameliorates CM clinical signs, resulting in complete healing, is urgently needed. Previously, we showed a hyperbaric oxygen (HBO)-protective effect against experimental CM. Here, we provide molecular evidence that HBO targets brain endothelial cells by decreasing their activation and inhibits parasite and leukocyte accumulation, thus improving cerebral microcirculatory blood flow. HBO treatment increased the expression of aryl hydrocarbon receptor over hypoxia-inducible factor 1-α (HIF-1α), an oxygen-sensitive cytosolic receptor, along with decreased indoleamine 2,3-dioxygenase 1 expression and kynurenine levels. Moreover, ablation of HIF-1α expression in endothelial cells in mice conferred protection against CM and improved survival. We propose that HBO should be pursued as an adjunctive therapy in CM patients to prolong survival and diminish deleterious proinflammatory reaction. Furthermore, our data support the use of HBO in therapeutic strategies to improve outcomes of non-CM disorders affecting the brain.-Bastos, M. F., Kayano, A. C. A. V., Silva-Filho, J. L., Dos-Santos, J. C. K., Judice, C., Blanco, Y. C., Shryock, N., Sercundes, M. K., Ortolan, L. S., Francelin, C., Leite, J. A., Oliveira, R., Elias, R. M., Câmara, N. O. S., Lopes, S. C. P., Albrecht, L., Farias, A. S., Vicente, C. P., Werneck, C. C., Giorgio, S., Verinaud, L., Epiphanio, S., Marinho, C. R. F., Lalwani, P., Amino, R., Aliberti, J., Costa, F. T. M. Inhibition of hypoxia-associated response and kynurenine production in response to hyperbaric oxygen

  18. Radiosensitization of normoxic and hypoxic h1339 lung tumor cells by heat shock protein 90 inhibition is independent of hypoxia inducible factor-1α.

    Schilling, Daniela; Bayer, Christine; Li, Wei; Molls, Michael; Vaupel, Peter; Multhoff, Gabriele

    2012-01-01

    Ionizing irradiation is a commonly accepted treatment modality for lung cancer patients. However, the clinical outcome is hampered by normal tissue toxicity and tumor hypoxia. Since tumors often have higher levels of active heat shock protein 90 (Hsp90) than normal tissues, targeting of Hsp90 might provide a promising strategy to sensitize tumors towards irradiation. Hsp90 client proteins include oncogenic signaling proteins, cell cycle activators, growth factor receptors and hypoxia inducible factor-1α (HIF-1α). Overexpression of HIF-1α is assumed to promote malignant transformation and tumor progression and thus might reduce the accessibility to radiotherapy. Herein, we describe the effects of the novel Hsp90 inhibitor NVP-AUY922 and 17-allylamino-17-demethoxygeldanamycin (17-AAG), as a control, on HIF-1α levels and radiosensitivity of lung carcinoma cells under normoxic and hypoxic conditions. NVP-AUY922 exhibited a similar biological activity to that of 17-AAG, but at only 1/10 of the dose. As expected, both inhibitors reduced basal and hypoxia-induced HIF-1α levels in EPLC-272H lung carcinoma cells. However, despite a down-regulation of HIF-1α upon Hsp90 inhibition, sensitivity towards irradiation remained unaltered in EPLC-272H cells under normoxic and hypoxic conditions. In contrast, treatment of H1339 lung carcinoma cells with NVP-AUY922 and 17-AAG resulted in a significant up-regulation of their initially high HIF-1α levels and a concomitant increase in radiosensitivity. In summary, our data show a HIF-1α-independent radiosensitization of normoxic and hypoxic H1339 lung cancer cells by Hsp90 inhibition.

  19. Inhibition of Hypoxia Inducible Factor Alpha and Astrocyte-Elevated Gene-1 Mediates Cryptotanshinone Exerted Antitumor Activity in Hypoxic PC-3 Cells

    Hyo-Jeong Lee

    2012-01-01

    Full Text Available Although cryptotanshinone (CT was known to exert antitumor activity in several cancers, its molecular mechanism under hypoxia still remains unclear. Here, the roles of AEG-1 and HIF-1α in CT-induced antitumor activity were investigated in hypoxic PC-3 cells. CT exerted cytotoxicity against prostate cancer cells and suppressed HIF-1α accumulation and AEG-1 expression in hypoxic PC-3 cells. Also, AEG-1 was overexpressed in prostate cancer cells. Interestingly, HIF-1α siRNA transfection enhanced the cleavages of caspase-9,3, and PAPR and decreased expression of Bcl-2 and AEG1 induced by CT in hypoxic PC-3 cells. Of note, DMOG enhanced the stability of AEG-1 and HIF-1α during hypoxia. Additionally, CT significantly reduced cellular level of VEGF in PC-3 cells and disturbed tube formation of HUVECs. Consistently, ChIP assay revealed that CT inhibited the binding of HIF-1α to VEGF promoter. Furthermore, CT at 10 mg/kg suppressed the growth of PC-3 cells in BALB/c athymic nude mice by 46.4% compared to untreated control. Consistently, immunohistochemistry revealed decreased expression of Ki-67, CD34, VEGF, carbonic anhydrase IX, and AEG-1 indices in CT-treated group compared to untreated control. Overall, our findings suggest that CT exerts antitumor activity via inhibition of HIF-1α, AEG1, and VEGF as a potent chemotherapeutic agent.

  20. Epidermal growth factor receptor inhibition reduces angiogenesis via hypoxia-inducible factor-1α and Notch1 in head neck squamous cell carcinoma.

    Wei-Ming Wang

    Full Text Available Angiogenesis, a marker of cancer development, affects response to radiotherapy sensibility. This preclinical study aims to understand the receptor tyrosine kinase-mediated angiogenesis in head neck squamous cell carcinoma (HNSCC. The receptor tyrosine kinase activity in a transgenic mouse model of HNSCC was assessed. The anti-tumorigenetic and anti-angiogenetic effects of cetuximab-induced epidermal growth factor receptor (EGFR inhibition were investigated in xenograft and transgenic mouse models of HNSCC. The signaling transduction of Notch1 and hypoxia-inducible factor-1α (HIF-1α was also analyzed. EGFR was overexpressed and activated in the Tgfbr1/Pten deletion (2cKO mouse model of HNSCC. Cetuximab significantly delayed tumor onset by reducing tumor angiogenesis. This drug exerted similar effects on heterotopic xenograft tumors. In the human HNSCC tissue array, increased EGFR expression correlated with increased HIF-1α and micro vessel density. Cetuximab inhibited tumor-induced angiogenesis in vitro and in vivo by significantly downregulating HIF-1α and Notch1. EGFR is involved in the tumor angiogenesis of HNSCC via the HIF-1α and Notch1 pathways. Therefore, targeting EGFR by suppressing hypoxia- and Notch-induced angiogenesis may benefit HNSCC therapy.

  1. Rhodiola crenulata and Its Bioactive Components, Salidroside and Tyrosol, Reverse the Hypoxia-Induced Reduction of Plasma-Membrane-Associated Na,K-ATPase Expression via Inhibition of ROS-AMPK-PKCξ Pathway

    Shih-Yu Lee

    2013-01-01

    Full Text Available Exposure to hypoxia leads to impaired pulmonary sodium transport, which is associated with Na,K-ATPase dysfunction in the alveolar epithelium. The present study is designed to examine the effect and mechanism of Rhodiola crenulata extract (RCE and its bioactive components on hypoxia-mediated Na,K-ATPase endocytosis. A549 cells were exposed to hypoxia in the presence or absence of RCE, salidroside, or tyrosol. The generation of intracellular ROS was measured by using the fluorescent probe DCFH-DA, and the endocytosis was determined by measuring the expression level of Na,K-ATPase in the PM fraction. Rats exposed to a hypobaric hypoxia chamber were used to investigate the efficacy and underlying mechanism of RCE in vivo. Our results showed that RCE and its bioactive compounds significantly prevented the hypoxia-mediated endocytosis of Na,K-ATPase via the inhibition of the ROS-AMPK-PKCζ pathway in A549 cells. Furthermore, RCE also showed a comparable preventive effect on the reduction of Na,K-ATPase endocytosis and inhibition of AMPK-PKCξ pathway in the rodent model. Our study is the first to offer substantial evidence to support the efficacy of Rhodiola products against hypoxia-associated Na,K-ATPase endocytosis and clarify the ethnopharmacological relevance of Rhodiola crenulata as a popular folk medicine for high-altitude illness.

  2. Yessotoxin, a Marine Toxin, Exhibits Anti-Allergic and Anti-Tumoural Activities Inhibiting Melanoma Tumour Growth in a Preclinical Model.

    Araceli Tobío

    Full Text Available Yessotoxins (YTXs are a group of marine toxins produced by the dinoflagellates Protoceratium reticulatum, Lingulodinium polyedrum and Gonyaulax spinifera. They may have medical interest due to their potential role as anti-allergic but also anti-cancer compounds. However, their biological activities remain poorly characterized. Here, we show that the small molecular compound YTX causes a slight but significant reduction of the ability of mast cells to degranulate. Strikingly, further examination revealed that YTX had a marked and selective cytotoxicity for the RBL-2H3 mast cell line inducing apoptosis, while primary bone marrow derived mast cells were highly resistant. In addition, YTX exhibited strong cytotoxicity against the human B-chronic lymphocytic leukaemia cell line MEC1 and the murine melanoma cell line B16F10. To analyse the potential role of YTX as an anti-cancer drug in vivo we used the well-established B16F10 melanoma preclinical mouse model. Our results demonstrate that a few local application of YTX around established tumours dramatically diminished tumour growth in the absence of any significant toxicity as determined by the absence of weight loss and haematological alterations. Our data support that YTX may have a minor role as an anti-allergic drug, but reveals an important potential for its use as an anti-cancer drug.

  3. Hypoxia-inducible factors - regulation, role and comparative aspects in tumourigenesis

    Hansen, A E; Kristensen, A T; Law, I

    2011-01-01

    important prognostic information and may help identify potential hypoxia circumventing and targeting strategies. This review summarizes current knowledge on HIF regulation and function in tumour cells and discusses the aspects of using companion animals as comparative spontaneous cancer models. Spontaneous...... tumours in companion animals hold a great research potential for the evaluation and understanding of tumour hypoxia and in the development of hypoxia-targeting therapeutics....

  4. Severe hypoxia induces chemo-resistance in clinical cervical tumors through MVP over-expression.

    Lara, Pedro C; Lloret, Marta; Clavo, Bernardino; Apolinario, Rosa M; Henríquez-Hernández, Luis Alberto; Bordón, Elisa; Fontes, Fausto; Rey, Agustín

    2009-08-06

    Oxygen molecule modulates tumour response to radiotherapy. Higher radiation doses are required under hypoxic conditions to induce cell death. Hypoxia may inhibit the non-homologous end-joining DNA repair through down regulating Ku70/80 expression. Hypoxia induces drug resistance in clinical tumours, although the mechanism is not clearly elucidated. Vaults are ribonucleoprotein particles with a hollow barrel-like structure composed of three proteins: major vault protein (MVP), vault poly(ADP-ribose) polymerase, and telomerase associated protein-1 and small untranslated RNA. Over-expression of MVP has been associated with chemotherapy resistance. Also, it has been related to poor outcome in patients treated with radiotherapy alone. The aim of the present study was to assess the relation of Major Vault Protein expression and tumor hypoxia in clinical cervical tumors. MVP, p53 and angiogenesis, together with tumor oxygenation, were determined in forty-three consecutive patients suffering from localized cervix carcinoma. High MVP expression was related to severe hypoxia compared to low MVP expressing tumors (p = 0.022). Tumors over-expressing MVP also showed increased angiogenesis (p = 0.003). Besides it, in this study we show for the first time that severe tumor hypoxia is associated with high MVP expression in clinical cervical tumors. Up-regulation of MVP by hypoxia is of critical relevance as chemotherapy is currently a standard treatment for those patients. From our results it could be suggested that hypoxia not only induces increased genetic instability, oncogenic properties and metastatization, but through the correlation observed with MVP expression, another pathway of chemo and radiation resistance could be developed.

  5. Severe hypoxia induces chemo-resistance in clinical cervical tumors through MVP over-expression

    Lara, Pedro C; Lloret, Marta; Clavo, Bernardino; Apolinario, Rosa M; Henríquez-Hernández, Luis Alberto; Bordón, Elisa; Fontes, Fausto; Rey, Agustín

    2009-01-01

    Oxygen molecule modulates tumour response to radiotherapy. Higher radiation doses are required under hypoxic conditions to induce cell death. Hypoxia may inhibit the non-homologous end-joining DNA repair through down regulating Ku70/80 expression. Hypoxia induces drug resistance in clinical tumours, although the mechanism is not clearly elucidated. Vaults are ribonucleoprotein particles with a hollow barrel-like structure composed of three proteins: major vault protein (MVP), vault poly(ADP-ribose) polymerase, and telomerase associated protein-1 and small untranslated RNA. Over-expression of MVP has been associated with chemotherapy resistance. Also, it has been related to poor outcome in patients treated with radiotherapy alone. The aim of the present study was to assess the relation of Major Vault Protein expression and tumor hypoxia in clinical cervical tumors. MVP, p53 and angiogenesis, together with tumor oxygenation, were determined in forty-three consecutive patients suffering from localized cervix carcinoma. High MVP expression was related to severe hypoxia compared to low MVP expressing tumors (p = 0.022). Tumors over-expressing MVP also showed increased angiogenesis (p = 0.003). Besides it, in this study we show for the first time that severe tumor hypoxia is associated with high MVP expression in clinical cervical tumors. Up-regulation of MVP by hypoxia is of critical relevance as chemotherapy is currently a standard treatment for those patients. From our results it could be suggested that hypoxia not only induces increased genetic instability, oncogenic properties and metastatization, but through the correlation observed with MVP expression, another pathway of chemo and radiation resistance could be developed

  6. Edaravone inhibits hypoxia-induced trophoblast-soluble Fms-like tyrosine kinase 1 expression: a possible therapeutic approach to preeclampsia.

    Zhao, Y; Zheng, Y F; Luo, Q Q; Yan, T; Liu, X X; Han, L; Zou, L

    2014-07-01

    To investigate the effects of edaravone, a potent free radical scavenger used clinically, on hypoxia-induced trophoblast-soluble Fms-like tyrosine kinase 1 (sFlt-1) expression. A trophoblast cell line (HRT-8/SVneo) impaired by cobalt chloride (CoCl2) was used as the cell model under hypoxic conditions. 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide (MTT) was used to measure the viability of cells exposed to CoCl2 and edaravone. The levels of intracellular reactive oxygen species (ROS) were analyzed by flow cytometry. mRNA expression of sFlt-1, vascular endothelial growth factor (VEGF), and placental growth factor (PlGF) in trophoblasts was measured by real-time polymerase chain reaction, and the secretion of sFlt-1, VEGF, and PlGF proteins was analyzed by enzyme-linked immunosorbent assays (ELISAs). A human umbilical vein endothelial cell (HUVEC) tube-formation assay was performed to identify the effects of CoCl2 and edaravone on vascular development. CoCl2 treatment caused the loss of trophoblast viability, the formation of ROS, and sFlt-1 mRNA and protein expression in a dose-dependent manner. Pretreatment with edaravone significantly inhibited hypoxia-induced oxidative stress formation and sFlt-1 expression in trophoblasts. Neither PlGF nor VEGF mRNA or protein expression was increased by CoCl2. In the in vitro tube formation assay, edaravone showed a protective role in vascular development under hypoxic conditions. This study demonstrated that hypoxia leading to increased sFlt-1 release in trophoblasts may contribute to the placental vascular formation abnormalities observed in preeclampsia and suggested that the free radical scavenger edaravone could be a candidate for the effective treatment of preeclampsia. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Increased tumour ascorbate is associated with extended disease-free survival and decreased hypoxia-inducible factor-1 activation in human colorectal cancer

    Caroline eKuiper

    2014-02-01

    Full Text Available Ascorbate is a co-factor for the hydroxylases that regulate the transcription factor hypoxia-inducible factor (HIF-1, which provides cancer cells with a metabolic and survival advantage in the hypoxic environment of solid tumors. However, whether ascorbate affects tumor development is a highly debated issue. We aimed to determine whether tumor ascorbate was associated with HIF-1 activation and patient disease-free survival. In this study we undertook a retrospective observational analysis of tissue-banked tumor and paired normal tissue from 49 colorectal cancer patients, measuring ascorbate levels, HIF-1α and its downstream gene products BNIP3 and VEGF. Patient survival was monitored for the first six years after surgery. We found that ascorbate levels were lower in tumor tissue compared to normal tissue (p< 0.001 but overall levels varied considerably. HIF-1α, VEGF and BNIP3 were elevated in tumor samples (p< 0.01. There was an inverse relationship between tumor ascorbate content and HIF-1 pathway activation (p=0.002 and tumor size (p=0.018. Higher tumor ascorbate content was associated with significantly improved disease-free survival in the first 6 years after surgery (p=0.006, with 141 - 1,094 additional disease free days. This was independent of tumor grade and stage. Survival advantage was associated with the amount of ascorbate in the tumor, but not with the amount in adjacent normal tissue. Our results demonstrate that higher tumor ascorbate content is associated decreased HIF-1 activation, most likely due to the co-factor activity of ascorbate for the regulatory HIF hydroxylases. Our findings support the need for future studies to determine whether raising tumor ascorbate is possible with clinical intervention and whether this results in modification of hydroxylase-dependent pathways in the tumor.

  8. Hypoxia targeting copper complexes

    Dearling, J.L.

    1998-11-01

    The importance and incidence of tumour hypoxia, its measurement and current treatments available, including pharmacological and radiopharmacological methods of targeting hypoxia, are discussed. A variety of in vitro and in vivo methods for imposing hypoxia have been developed and are reviewed. Copper, its chemistry, biochemistry and radiochemistry, the potential for use of copper radionuclides and its use to date in this field is considered with particular reference to the thiosemicarbazones. Their biological activity, metal chelation, in vitro and in vivo studies of their radiocopper complexes and the potential for their use as hypoxia targeting radiopharmaceuticals is described. The reduction of the copper(II) complex to copper(l), its pivotal importance in their biological behaviour, and the potential for manipulation of this to effect hypoxia selectivity are described. An in vitro method for assessing the hypoxia selectivity of radiopharmaceuticals is reported. The rapid deoxygenation and high viability of a mammalian cell culture in this system is discussed and factors which may affect the cellular uptake of a radiopharmaceutical are described. The design, synthesis and complexation with copper and radiocopper of a range of bis(thiosemicarbazones) is reported. Synthesis of these compounds is simple giving high yields of pure products. The characteristics of the radiocopper complexes ( 64 Cu) including lipophilicity and redox activity are reported (reduction potentials in the range -0.314 - -0.590 V). High cellular uptakes of the radiocopper complexes of the ligands, in hypoxic and normoxic EMT6 and CHO320 cells, were observed. Extremes of selectivity are shown ranging from the hypoxia selective 64 Cu(II)ATSM to normoxic cell selective 64 Cu(II)GTS. The selectivities observed are compared with the physico chemical characteristics of the complexes. A good correlation exists between selectivity of the complex and its Cu(II)/Cu(I) reduction potential, with hypoxia

  9. Prodigiosin inhibits gp91{sup phox} and iNOS expression to protect mice against the oxidative/nitrosative brain injury induced by hypoxia-ischemia

    Chang, Chia-Che [Institute of Biomedical Sciences, National Chung-Hsing University, Taichung, Taiwan (China); Graduate Institute of Basic Medical Science, China Medical University, Taichung, Taiwan (China); Agricultural Biotechnology Center, National Chung-Hsing University, Taichung, Taiwan (China); Center of Infectious Disease and Signaling Research, National Cheng Kung University, Tainan, Taiwan (China); Wang, Yea-Hwey [Department of Nursing, College of Medicine and Nursing, Hungkuang University, Taichung, Taiwan (China); Chern, Chang-Ming [Division of Neurovascular Disease, Neurological Institute, Taipei Veterans General Hospital and School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Liou, Kuo-Tong [Department of Chinese Martial Arts, Chinese Culture University, Taipei, Taiwan (China); Hou, Yu-Chang [Department of Chinese Medicine, Taoyuan General Hospital, Department of Health, Taiwan (China); Department of Nursing, Yuanpei University, Hsinchu, Taiwan (China); Department of Bioscience Technology, Chuan-Yuan Christian University, Taoyuan, Taiwan (China); Peng, Yu-Ta [Institute of Biomedical Sciences, National Chung-Hsing University, Taichung, Taiwan (China); Shen, Yuh-Chiang, E-mail: yuhcs@nricm.edu.tw [National Research Institute of Chinese Medicine, Taipei, Taiwan (China); Institute of Biomedical Sciences, National Chung-Hsing University, Taichung, Taiwan (China)

    2011-11-15

    This study aimed to explore the mechanisms by which prodigiosin protects against hypoxia-induced oxidative/nitrosative brain injury induced by middle cerebral artery occlusion/reperfusion (MCAo/r) injury in mice. Hypoxia in vitro was modeled using oxygen-glucose deprivation (OGD) followed by reoxygenation of BV-2 microglial cells. Our results showed that treatment of mice that have undergone MCAo/r injury with prodigiosin (10 and 100 {mu}g/kg, i.v.) at 1 h after hypoxia ameliorated MCAo/r-induced oxidative/nitrosative stress, brain infarction, and neurological deficits in the mice, and enhanced their survival rate. MCAo/r induced a remarkable production in the mouse brains of reactive oxygen species (ROS) and a significant increase in protein nitrosylation; this primarily resulted from enhanced expression of NADPH oxidase 2 (gp91{sup phox}), inducible nitric oxide synthase (iNOS), and the infiltration of CD11b leukocytes due to breakdown of blood-brain barrier (BBB) by activation of nuclear factor-kappa B (NF-{kappa}B). All these changes were significantly diminished by prodigiosin. In BV-2 cells, OGD induced ROS and nitric oxide production by up-regulating gp91{sup phox} and iNOS via activation of the NF-{kappa}B pathway, and these changes were suppressed by prodigiosin. In conclusion, our results indicate that prodigiosin reduces gp91{sup phox} and iNOS expression possibly by impairing NF-{kappa}B activation. This compromises the activation of microglial and/or inflammatory cells, which then, in turn, mediates prodigiosin's protective effect in the MCAo/r mice. -- Highlights: Black-Right-Pointing-Pointer Prodigiosin ameliorated brain infarction and deficits. Black-Right-Pointing-Pointer Prodigiosin protected against hypoxia/reperfusion-induced brain injury. Black-Right-Pointing-Pointer Prodigiosin diminished oxidative/nitrosativestress and leukocytes infiltration. Black-Right-Pointing-Pointer Prodigiosin reduced BBB breakdown. Black

  10. Brief Daily Episode of Normoxia Inhibits Cardioprotection Conferred by Chronic Continuous Hypoxia. Role of Oxidative Stress and BKCa Channels

    Neckář, Jan; Borchert, Gudrun H.; Hloušková, P.; Míčová, P.; Nováková, O.; Novák, F.; Hroch, M.; Papoušek, František; Ošťádal, Bohuslav; Kolář, František

    2013-01-01

    Roč. 19, č. 39 (2013), s. 6880-6889 ISSN 1381-6128 R&D Projects: GA AV ČR(CZ) IAAX01110901; GA ČR(CZ) GA305/07/0875; GA ČR(CZ) GAP303/12/1162 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : chronic continuous hypoxia * reoxygenation * ischemia/reperfusion * myocardial infarction * potassium channels * oxidative stress Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 3.288, year: 2013

  11. Angiotensin-(1?7) inhibits inflammation and oxidative stress to relieve lung injury induced by chronic intermittent hypoxia in rats

    Lu, W.; Kang, J.; Hu, K.; Tang, S.; Zhou, X.; Yu, S.; Li, Y.; Xu, L.

    2016-01-01

    Obstructive sleep apnea is associated with inflammation and oxidative stress in lung tissues and can lead to metabolic abnormalities. We investigated the effects of angiotensin1–7 [Ang-(1–7)] on lung injury in rats induced by chronic intermittent hypoxia (CIH). We randomly assigned 32 male Sprague-Dawley rats (180–200 g) to normoxia control (NC), CIH-untreated (uCIH), Ang-(1–7)-treated normoxia control (N-A), and Ang-(1–7)-treated CIH (CIH-A) groups. Oxidative stress biomarkers were measured ...

  12. Caffeic acid phenethyl ester inhibits 3-MC-induced CYP1A1 expression through induction of hypoxia-inducible factor-1α

    Kim, Hyung Gyun [Department of Toxicology, College of Pharmacy, Chungnam National University, Daejeon (Korea, Republic of); Han, Eun Hee [Division of Life Science, Korea Basic Science Institute, Daejeon (Korea, Republic of); Im, Ji Hye; Lee, Eun Ji; Jin, Sun Woo [Department of Toxicology, College of Pharmacy, Chungnam National University, Daejeon (Korea, Republic of); Jeong, Hye Gwang, E-mail: hgjeong@cnu.ac.kr [Department of Toxicology, College of Pharmacy, Chungnam National University, Daejeon (Korea, Republic of)

    2015-09-25

    Caffeic acid phenethyl ester (CAPE), a natural component of propolis, is reported to have anticarcinogenic properties, although its precise chemopreventive mechanism remains unclear. In this study, we examined the effects of CAPE on 3-methylcholanthrene (3-MC)-induced CYP1A1 expression and activities. CAPE reduced the formation of the benzo[a]pyrene-DNA adduct. Moreover, CAPE inhibited 3-MC-induced CYP1A1 activity, mRNA expression, protein level, and promoter activity. CAPE treatment also decreased 3-MC-inducible xenobiotic-response element (XRE)-linked luciferase, aryl hydrocarbons receptor (AhR) transactivation and nuclear localization. CAPE induced hypoxia inducible factor-1α (HIF-1α) protein level and HIF-1α responsible element (HRE) transcriptional activity. CAPE-mediated HIF-1α reduced 3-MC-inducible CYP1A1 protein expression. Taken together, CAPE decreases 3-MC-mediated CYP1A1 expression, and this inhibitory response is associated with inhibition of AhR and HIF-1α induction. - Highlights: • CAPE reduced the formation of the benzo[a]pyrene-DNA adduct. • CAPE inhibited 3-MC-induced CYP1A1 expression. • CAPE induced HIF-1α induction. • CAPE-mediated HIF-1α reduced 3-MC-inducible CYP1A1 expression.

  13. JS-K has potent anti-angiogenic activity in vitro and inhibits tumour angiogenesis in a multiple myeloma model in vivo.

    Kiziltepe, Tanyel; Anderson, Kenneth C; Kutok, Jeffery L; Jia, Lee; Boucher, Kenneth M; Saavedra, Joseph E; Keefer, Larry K; Shami, Paul J

    2010-01-01

    Glutathione S-transferases (GSTs) play an important role in multidrug resistance and are upregulated in multiple cancers. We have designed a prodrug class that releases nitric oxide on metabolism by GST. O(2)-(2,4-Dinitrophenyl) 1-[(4-ethoxycarbonyl)piperazin-1-yl]diazen-1-ium-1,2-diolate (JS-K, a member of this class) has potent antineoplastic activity. We studied the effect of JS-K on angiogenesis in human umbilical vein endothelial cells (HUVECs), OPM1 multiple myeloma cells, chick aortic rings and in mice. JS-K inhibited the proliferation of HUVECs with a 50% inhibitory concentration (IC50) of 0.432, 0.466 and 0.505 microm at 24, 48 and 72 h, respectively. In the cord formation assay, JS-K led to a decrease in the number of cord junctions and cord length with an IC50 of 0.637 and 0.696 microm, respectively. JS-K inhibited cell migration at 5 h using VEGF as a chemoattractant. Migration inhibition occurred with an IC50 of 0.493 microm. In the chick aortic ring assay using VEGF or FGF-2 for vessel growth stimulation, 0.5 microm JS-K completely inhibited vessel growth. JS-K inhibited tumour angiogenesis in vivo in NIH III mice implanted subcutaneously with OPM1 multiple myeloma cells. JS-K is a potent inhibitor of angiogenesis in vitro and tumour vessel growth in vivo. As such, it establishes a new class of antineoplastic agent that targets the malignant cells directly as well as their microenvironment.

  14. VEGF(121)b, a new member of the VEGF(xxx)b family of VEGF-A splice isoforms, inhibits neovascularisation and tumour growth in vivo.

    Rennel, E S; Varey, A H R; Churchill, A J; Wheatley, E R; Stewart, L; Mather, S; Bates, D O; Harper, S J

    2009-10-06

    The key mediator of new vessel formation in cancer and other diseases is VEGF-A. VEGF-A exists as alternatively spliced isoforms - the pro-angiogenic VEGF(xxx) family generated by exon 8 proximal splicing, and a sister family, termed VEGF(xxx)b, exemplified by VEGF(165)b, generated by distal splicing of exon 8. However, it is unknown whether this anti-angiogenic property of VEGF(165)b is a general property of the VEGF(xxx)b family of isoforms. The mRNA and protein expression of VEGF(121)b was studied in human tissue. The effect of VEGF(121)b was analysed by saturation binding to VEGF receptors, endothelial migration, apoptosis, xenograft tumour growth, pre-retinal neovascularisation and imaging of biodistribution in tumour-bearing mice with radioactive VEGF(121)b. The existence of VEGF(121)b was confirmed in normal human tissues. VEGF(121)b binds both VEGF receptors with similar affinity as other VEGF isoforms, but inhibits endothelial cell migration and is cytoprotective to endothelial cells through VEGFR-2 activation. Administration of VEGF(121)b normalised retinal vasculature by reducing both angiogenesis and ischaemia. VEGF(121)b reduced the growth of xenografted human colon tumours in association with reduced microvascular density, and an intravenous bolus of VEGF(121)b is taken up into colon tumour xenografts. Here we identify a second member of the family, VEGF(121)b, with similar properties to those of VEGF(165)b, and underline the importance of the six amino acids of exon 8b in the anti-angiogenic activity of the VEGF(xxx)b isoforms.

  15. Andrographolide inhibits hypoxia-induced HIF-1α-driven endothelin 1 secretion by activating Nrf2/HO-1 and promoting the expression of prolyl hydroxylases 2/3 in human endothelial cells.

    Lin, Hung-Chih; Su, Shih-Li; Lu, Chia-Yang; Lin, Ai-Hsuan; Lin, Wan-Chun; Liu, Chin-San; Yang, Ya-Chen; Wang, Hsiu-Miao; Lii, Chong-Kuei; Chen, Haw-Wen

    2017-03-01

    Andrographolide, the main bioactive component of the medicinal plant Andrographis paniculata, has been shown to possess potent anti-inflammatory activity. Endothelin 1 (ET-1), a potent vasoconstrictor peptide produced by vascular endothelial cells, displays proinflammatory property. Hypoxia-inducible factor 1α (HIF-1α), the regulatory member of the transcription factor heterodimer HIF-1α/β, is one of the most important molecules that responds to hypoxia. Changes in cellular HIF-1α protein level are the result of altered gene transcription and protein stability, with the latter being dependent on prolyl hydroxylases (PHDs). In this study, inhibition of pro-inflammatory ET-1 expression and changes of HIF-1α gene transcription and protein stability under hypoxia by andrographolide in EA.hy926 endothelial-like cells were investigated. Hypoxic conditions were created using the hypoxia-mimetic agent CoCl 2. We found that hypoxia stimulated the production of reactive oxygen species (ROS), the expression of HIF-1α mRNA and protein, and the expression and secretion of ET-1. These effects, however, were attenuated by co-exposure to andrographolide, bilirubin, and RuCO. Silencing Nrf2 and heme oxygenase 1 (HO-1) reversed the inhibitory effects of andrographolide on hypxoia-induced HIF-1α mRNA and protein expression. Moreover, andrographolide increased the expression of prolyl hydroxylases (PHD) 2/3, which hydroxylate HIF-1α and promotes HIF-1α proteasome degradation, with an increase in HIF-1α hydroxylation was noted under hypoxia. Inhibition of p38 MAPK abrogated the hypoxia-induced increases in HIF-1α mRNA and protein expression as well as ET-1 mRNA expression and secretion. Taken together, these results suggest that andrographolide suppresses hypoxia-induced pro-inflammatory ET-1 expression by activating Nrf2/HO-1, inhibiting p38 MAPK signaling, and promoting PHD2/3 expression. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 918-930, 2017. © 2016 Wiley

  16. Sestrin2 induced by hypoxia inducible factor1 alpha protects the blood-brain barrier via inhibiting VEGF after severe hypoxic-ischemic injury in neonatal rats.

    Shi, Xudan; Doycheva, Desislava Met; Xu, Liang; Tang, Jiping; Yan, Min; Zhang, John H

    2016-11-01

    Hypoxic ischemic (HI) encephalopathy remains the leading cause of perinatal brain injury resulting in long term disabilities. Stabilization of blood brain barrier (BBB) after HI is an important target, therefore, in this study we aim to determine the role of sestrin2, a stress inducible protein which is elevated after various insults, on BBB stabilization after moderate and severe HI injuries. Rat pups underwent common carotid artery ligation followed by either 150min (severe model) or 100min (moderate model) of hypoxia. 1h post HI, rats were intranasally administered with recombinant human sestrin2 (rh-sestrin2) and sacrificed for infarct area, brain water content, righting reflex and geotaxis reflex. Sestrin2 was silenced using siRNA and an activator/inhibitor of hypoxia inducible factor1α (HIF1α) was used to examine their roles on BBB permeability. Rats subjected to severe HI exhibited larger infarct area and higher sestrin2 expression compared to rats in the moderate HI group. rh-sestrin2 attenuated brain infarct and edema, while silencing sestrin2 reversed these protective effects after severe HI. HIF1α induced sestrin2 activation in severe HI but not in moderate HI groups. A HIF1a agonist was shown to increase permeability of the BBB via vascular endothelial growth factor (VEGF) after moderate HI. However, after severe HI, HIF1α activated both VEGF and sestrin2. But HIF1α dependent sestrin2 activation was the predominant pathway after severe HI which inhibited VEGF and attenuated BBB permeability. rh-sestrin2 attenuated BBB permeability via upregulation of endogenous sestrin2 which was induced by HIF1α after severe HI. However, HIF1α's effects as a prodeath or prosurvival signal were influenced by the severity of HI injury. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Ginsenoside Rb1 Protects Neonatal Rat Cardiomyocytes from Hypoxia/Ischemia Induced Apoptosis and Inhibits Activation of the Mitochondrial Apoptotic Pathway

    Xu Yan

    2014-01-01

    Full Text Available Aim. To investigate the effect of Ginsenoside Rb1 (GS-Rb1 on hypoxia/ischemia (H/I injury in cardiomyocytes in vitro and the mitochondrial apoptotic pathway mediated mechanism. Methods. Neonatal rat cardiomyocytes (NRCMs for the H/I groups were kept in DMEM without glucose and serum, and were placed into a hypoxic jar for 24 h. GS-Rb1 at concentrations from 2.5 to 40 µM was given during hypoxic period for 24 h. NRCMs injury was determined by MTT and lactate dehydrogenase (LDH leakage assay. Cell apoptosis, ROS accumulation, and mitochondrial membrane potential (MMP were assessed by flow cytometry. Cytosolic translocation of mitochondrial cytochrome c and Bcl-2 family proteins were determined by Western blot. Caspase-3 and caspase-9 activities were determined by the assay kit. Results. GS-Rb1 significantly reduced cell death and LDH leakage induced by H/I. It also reduced H/I induced NRCMs apoptosis induced by H/I, in accordance with a minimal reactive oxygen species (ROS burst. Moreover, GS-Rb1 markedly decreased the translocation of cytochrome c from the mitochondria to the cytosol, increased the Bcl-2/ Bax ratio, and preserved mitochondrial transmembrane potential (ΔΨm. Its administration also inhibited activities of caspase-9 and caspase-3. Conclusion. Administration of GS-Rb1 during H/I in vitro is involved in cardioprotection by inhibiting apoptosis, which may be due to inhibition of the mitochondrial apoptotic pathway.

  18. Inhibition of hypoxia inducible factor-1α downregulates the expression of epithelial to mesenchymal transition early marker proteins without undermining cell survival in hypoxic lens epithelial cells.

    Cammarata, Patrick R; Neelam, Sudha; Brooks, Morgan M

    2015-01-01

    The purpose of this study was to identify potential therapeutic strategies to slow down or prevent the expression of early-onset epithelial to mesenchymal transition (EMT) marker proteins (fibronectin and alpha smooth muscle actin, α-SMA) without sacrificing the synthesis and accumulation of the prosurvival protein vascular endothelial growth factor (VEGF) in cultured virally transformed human lens epithelial (HLE) cells. HLE-B3 cells, maintained in a continuous hypoxic environment (1% oxygen), were treated with SB216763, a specific inhibitor of glycogen synthase kinase-3β (GSK-3β) catalytic activity. Western blot analysis was employed to detect the cytoplasmic and nuclear levels of β-catenin, as well as the total lysate content of fibronectin and α-SMA. Enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of VEGF in cell culture medium. A hypoxia-inducible factor-1α (HIF-1α) translation inhibitor and an HIF-2α translation inhibitor were independently employed to evaluate the effect of hypoxia inducible factor inhibition on EMT marker protein and VEGF expression. XAV932 was used to assess the suppression of nuclear β-catenin and its downstream effect on EMT marker proteins and VEGF expression. SB216763-treated HLE-B3 cells caused marked inhibition of GSK-3β activity prompting a significant increase in the translocation of cytoplasmic β-catenin to the nucleus. The enhancement of nuclear β-catenin looked as if it positively correlated with a significant increase in the basal expression of VEGF as well as increased expression of fibronectin and α-SMA. In conjunction with SB216763, coadministration of an HIF-1α translation inhibitor, but not an HIF-2α translation inhibitor, markedly suppressed the expression of fibronectin and α-SMA without affecting VEGF levels. Treatment with XAV932 significantly reduced the level of nuclear β-catenin, but the levels of neither the EMT marker proteins nor VEGF were changed. Recently, we reported

  19. TUMOUR VACCINE

    Wagner, Ernst; Kircheis, Ralf; Crommelin, D.; Van Slooten, Maaike; Storm, Gert

    1999-01-01

    The invention relates to a tumour vaccine with a tumour antigen base. In addition to a source of tumour antigens, the vaccine contains a release system for the delayed release of the active agent IFN- gamma , the active dose of IFN- gamma being 50 ng to 5 mu g. The IFN- gamma is released over a

  20. Complex molecular mechanisms cooperate to mediate histone deacetylase inhibitors anti-tumour activity in neuroblastoma cells

    Nardou Katya

    2008-06-01

    Full Text Available Abstract Background Histone deacetylase inhibitors (HDACi are a new class of promising anti-tumour agent inhibiting cell proliferation and survival in tumour cells with very low toxicity toward normal cells. Neuroblastoma (NB is the second most common solid tumour in children still associated with poor outcome in higher stages and, thus NB strongly requires novel treatment modalities. Results We show here that the HDACi Sodium Butyrate (NaB, suberoylanilide hydroxamic acid (SAHA and Trichostatin A (TSA strongly reduce NB cells viability. The anti-tumour activity of these HDACi involved the induction of cell cycle arrest in the G2/M phase, followed by the activation of the intrinsic apoptotic pathway, via the activation of the caspases cascade. Moreover, HDACi mediated the activation of the pro-apoptotic proteins Bid and BimEL and the inactivation of the anti-apoptotic proteins XIAP, Bcl-xL, RIP and survivin, that further enhanced the apoptotic signal. Interestingly, the activity of these apoptosis regulators was modulated by several different mechanisms, either by caspases dependent proteolytic cleavage or by degradation via the proteasome pathway. In addition, HDACi strongly impaired the hypoxia-induced secretion of VEGF by NB cells. Conclusion HDACi are therefore interesting new anti-tumour agents for targeting highly malignant tumours such as NB, as these agents display a strong toxicity toward aggressive NB cells and they may possibly reduce angiogenesis by decreasing VEGF production by NB cells.

  1. Manganese (II) induces chemical hypoxia by inhibiting HIF-prolyl hydroxylase: Implication in manganese-induced pulmonary inflammation

    Han, Jeongoh; Lee, Jong-Suk; Choi, Daekyu; Lee, Youna; Hong, Sungchae; Choi, Jungyun; Han, Songyi; Ko, Yujin; Kim, Jung-Ae; Mi Kim, Young; Jung, Yunjin

    2009-01-01

    Manganese (II), a transition metal, causes pulmonary inflammation upon environmental or occupational inhalation in excess. We investigated a potential molecular mechanism underlying manganese-induced pulmonary inflammation. Manganese (II) delayed HIF-1α protein disappearance, which occurred by inhibiting HIF-prolyl hydroxylase (HPH), the key enzyme for HIF-1α hydroxylation and subsequent von Hippel-Lindau(VHL)-dependent HIF-1α degradation. HPH inhibition by manganese (II) was neutralized significantly by elevated dose of iron. Consistent with this, the induction of cellular HIF-1α protein by manganese (II) was abolished by pretreatment with iron. Manganese (II) induced the HIF-1 target gene involved in pulmonary inflammation, vascular endothelial growth factor (VEGF), in lung carcinoma cell lines. The induction of VEGF was dependent on HIF-1. Manganese-induced VEGF promoted tube formation of HUVEC. Taken together, these data suggest that HIF-1 may be a potential mediator of manganese-induced pulmonary inflammation

  2. Coumestrol suppresses hypoxia inducible factor 1α by inhibiting ROS mediated sphingosine kinase 1 in hypoxic PC-3 prostate cancer cells.

    Cho, Sung-Yun; Cho, Sunmi; Park, Eunkyung; Kim, Bonglee; Sohn, Eun Jung; Oh, Bumsuk; Lee, Eun-Ok; Lee, Hyo-Jeong; Kim, Sung-Hoon

    2014-06-01

    Among many signals to regulate hypoxia inducible factor 1α (HIF-1α), sphingosine kinase 1 (SPHK1) is also involved in various biological activities such as cell growth, survival, invasion, angiogenesis, and carcinogenesis. Thus, in the present study, molecular mechanisms of coumestrol were investigated on the SPHK1 and HIF-1α signaling pathway in hypoxic PC-3 prostate cancer cells. Coumestrol significantly suppressed SPHK1 activity and accumulation of HIF-1α in a time- and concentration-dependent manner in hypoxic PC-3 cells. In addition, coumestrol inhibited the phosphorylation status of AKT and glycogen synthase kinase-3β (GSK 3β) signaling involved in cancer metabolism. Furthermore, SPHK1 siRNA transfection, sphigosine kinase inhibitor (SKI), reactive oxygen species (ROS) enhanced the inhibitory effect of coumestrol on the accumulation of HIF-1α and the expression of pAKT and pGSK 3β in hypoxic PC-3 cells by combination index. Overall, our findings suggest that coumestrol suppresses the accumulation of HIF-1α via suppression of SPHK1 pathway in hypoxic PC-3 cells. Copyright © 2014. Published by Elsevier Ltd.

  3. Extracts of Crinum latifolium inhibit the cell viability of mouse lymphoma cell line EL4 and induce activation of anti-tumour activity of macrophages in vitro.

    Nguyen, Hoang-Yen T; Vo, Bach-Hue T; Nguyen, Lac-Thuy H; Bernad, Jose; Alaeddine, Mohamad; Coste, Agnes; Reybier, Karine; Pipy, Bernard; Nepveu, Françoise

    2013-08-26

    Crinum latifolium L. (CL) leaf extracts have been traditionally used in Vietnam and are now used all over the world for the treatment of prostate cancer. However, the precise cellular mechanisms of the action of CL extracts remain unclear. To examine the effects of CL samples on the anti-tumour activity of peritoneal murine macrophages. The properties of three extracts (aqueous, flavonoid, alkaloid), one fraction (alkaloid), and one pure compound (6-hydroxycrinamidine) obtained from CL, were studied (i) for redox capacities (DPPH and bleaching beta-carotene assays), (ii) on murine peritoneal macrophages (MTT assay) and on lymphoma EL4-luc2 cells (luciferine assay) for cytotoxicity, (iii) on macrophage polarization (production of ROS and gene expression by PCR), and (iv) on the tumoricidal functions of murine peritoneal macrophages (lymphoma cytotoxicity by co-culture with syngeneic macrophages). The total flavonoid extract with a high antioxidant activity (IC50=107.36 mg/L, DPPH assay) showed an inhibitory action on cancer cells. Alkaloid extracts inhibited the proliferation of lymphoma cells either by directly acting on tumour cells or by activating of the tumoricidal functions of syngeneic macrophages. The aqueous extract induced mRNA expression of tumour necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin 6 (IL-6) indicating differentiation of macrophages into pro-inflammatory M1 polarized macrophages. The total flavonoid, alkaloid extracts and an alkaloid fraction induced the expression of the formyl peptide receptor (FPR) on the surface of the polarized macrophages that could lead to the activation of macrophages towards the M1 phenotype. Aqueous and flavonoid extracts enhanced NADPH quinine oxido-reductase 1 (NQO1) mRNA expression in polarized macrophages which could play an important role in cancer chemoprevention. All the samples studied were non-toxic to normal living cells and the pure alkaloid tested, 6-hydroxycrinamidine, was not

  4. Effect of combined irradiation and EGFR/Erb-B inhibition with BIBW 2992 on proliferation and tumour cure in cell lines and xenografts

    Gurtner, Kristin; Ebert, Nadja; Pfitzmann, Dorothee; Eicheler, Wolfgang; Zips, Daniel; Baumann, Michael; Krause, Mechthild

    2014-01-01

    In previous experiments an enhanced anti-proliterative effect of the EGFR/ErbB tyrosine kinase inhibitor (TKI) BIBW 2992 with single dose irradiation was observed in FaDu tumour xenografts. Aim of the present experiment was to determine if this effect can also be seen in combination with a fractionated radiotherapy. Secondly we investigate the efficacy of BIBW 2992 on local tumour control for UT-SCC-15. Tumour pieces of FaDu, UT-SCC-14, A431, UT-SCC-15 (squamous cell carcinomas) and A7 (glioma) tumour models were transplanted onto the right hind leg of NMRI (nu/nu) nude mice. For evaluation of tumour growth mice were either treated daily orally with BIBW 2992 (30 mg/kg body weight), or carrier up to a final tumour size of 15 mm or with a fractionated radiotherapy (15f/15d, 30 Gy) with simultaneous application of BIBW 2992 or carrier. For local tumour control UT-SCC-15 tumours were treated with a fractionated radiotherapy (30f/6weeks) or received 30f/6 weeks in combination with daily orally BIBW 2992 (22.5 mg/kg b.w.) during RT. A significant effect on tumour growth time was observed in all tumour models for BIBW 2992 application alone. However, substantial intertumoural heterogeneity could be seen. In the UT-SCC-14, UT-SCC-15 and A431 tumour models a total regression of the tumours and no recurrence during treatment time (73 days) were determined where as for the A7 tumour only a slight effect was noticeable. For the combined treatment of fractionated radiotherapy (15f/15d) and BIBW 2992 administration a significant effect on tumour growth time was seen compared to irradiation alone for A7, UT-SCC-15 and A431 (ER 1.2 – 3.7), this advantage could not be demonstrated for FaDu and UT-SCC-14. However, the local tumour control was not altered for the UT-SCC-15 tumour model when adding BIBW 2992 to fractionated irradiation (30f/6weeks). A heterogeneous effect on tumour growth time of BIBW 2992 alone as well as in combination with fractionated irradiation could be

  5. Extract of corn silk (stigma of Zea mays) inhibits the tumour necrosis factor-alpha- and bacterial lipopolysaccharide-induced cell adhesion and ICAM-1 expression.

    Habtemariam, S

    1998-05-01

    Treatment of human endothelial cells with cytokines such as tumour necrosis factor-alpha (TNF) or E. coli lipopolysaccharide (LPS) induces the expression of several adhesion molecules and enhances leukocyte adhesion to endothelial cell surface. Interfering with this leukocyte adhesion or adhesion molecules upregulation is an important therapeutic target for the treatment of bacterial sepsis and various inflammatory diseases. In the course of screening marketed European anti-inflammatory herbal drugs for TNF antagonistic activity, a crude ethanolic extract of corn silk (stigma of Zea mays) exhibited significant activity. The extract at concentrations of 9-250 micrograms/ml effectively inhibited the TNF- and LPS-induced adhesiveness of EAhy 926 endothelial cells to monocytic U937 cells. Similar concentration ranges of corn silk extract did also block the TNF and LPS but not the phorbol 12-myristate 13-acetate-induced ICAM-1 expression on EAhy 926 endothelial cell surface. The extract did not alter the production of TNF by LPS-activated macrophages and failed to inhibit the cytotoxic activity of TNF. It is concluded that corn silk possesses important therapeutic potential for TNF- and LPS-mediated leukocyte adhesion and trafficking.

  6. Hypoxia induces copper stable isotope fractionation in hepatocellular carcinoma, in a HIF-independent manner.

    Bondanese, Victor P; Lamboux, Aline; Simon, Melanie; Lafont, Jérôme E; Albalat, Emmanuelle; Pichat, Sylvain; Vanacker, Jean-Marc; Telouk, Philippe; Balter, Vincent; Oger, Philippe; Albarède, Francis

    2016-11-09

    Hepatocellular carcinoma (HCC) is the most frequent type of primary liver cancer, with increasing incidence worldwide. The unrestrained proliferation of tumour cells leads to tumour hypoxia which in turn promotes cancer aggressiveness. While changes in the concentration of copper (Cu) have long been observed upon cancerization, we have recently reported that the isotopic composition of copper is also altered in several types of cancer. In particular, we showed that in hepatocellular carcinoma, tumour tissue contains heavier copper compared to the surrounding parenchyma. However, the reasons behind such isotopic signature remained elusive. Here we show that hypoxia causes heavy copper enrichment in several human cell lines. We also demonstrate that this effect of hypoxia is pH, HIF-1 and -2 independent. Our data identify a previously unrecognized cellular process associated with hypoxia, and suggests that in vivo tumour hypoxia determines copper isotope fractionation in HCC and other solid cancers.

  7. Globular Adiponectin Inhibits the Apoptosis of Mesenchymal Stem Cells Induced by Hypoxia and Serum Deprivation via the AdipoR1-Mediated Pathway

    Xia-Qiu Tian

    2016-02-01

    Full Text Available Background/Aims: Poor viability of transplanted mesenchymal stem cells (MSCs within the ischemic heart limits their therapeutic potential for cardiac repair. Globular adiponectin (gAPN exerts anti-apoptotic effects on several types of stem cells. Herein, we investigated the effect of gAPN on the MSCs against apoptosis induced by hypoxia and serum deprivation (H/SD. Methods: MSCs exposed to H/SD conditions were treated with different concentrations of gAPN. To identify the main type of receptor, MSCs were transfected with siRNA targeting adiponectin receptor 1 or 2 (AdipoR1 or AdipoR2. To elucidate the downstream pathway, MSCs were pre-incubated with AMPK inhibitor Compound C. Apoptosis, caspase-3 activity and mitochondrial membrane potential were evaluated. Results: H/SD-induced MSCs apoptosis and caspase-3 activation were attenuated by gAPN in a concentration-dependent manner. gAPN increased Bcl-2 and decreased Bax expressions. The loss of mitochondrial membrane potential induced by H/SD was also abolished by gAPN. The protective effect of gAPN was significantly attenuated after the knockdown of AdipoR1 rather than AdipoR2. Moreover, Compound C partly suppressed the anti-apoptotic effect of gAPN. Conclusions: gAPN inhibits H/SD-induced apoptosis in MSCs via AdipoR1-mediated pathway, possibly linked to the activation of AMPK. gAPN may be a novel survival factor for MSCs in the ischemic engraftment environment.

  8. Globular Adiponectin Inhibits the Apoptosis of Mesenchymal Stem Cells Induced by Hypoxia and Serum Deprivation via the AdipoR1-Mediated Pathway.

    Tian, Xia-Qiu; Yang, Yue-Jin; Li, Qing; Huang, Pei-Sen; Li, Xiang-Dong; Jin, Chen; Qi, Kang; Jiang, Lei-Pei; Chen, Gui-Hao

    2016-01-01

    Poor viability of transplanted mesenchymal stem cells (MSCs) within the ischemic heart limits their therapeutic potential for cardiac repair. Globular adiponectin (gAPN) exerts anti-apoptotic effects on several types of stem cells. Herein, we investigated the effect of gAPN on the MSCs against apoptosis induced by hypoxia and serum deprivation (H/SD). MSCs exposed to H/SD conditions were treated with different concentrations of gAPN. To identify the main type of receptor, MSCs were transfected with siRNA targeting adiponectin receptor 1 or 2 (AdipoR1 or AdipoR2). To elucidate the downstream pathway, MSCs were pre-incubated with AMPK inhibitor Compound C. Apoptosis, caspase-3 activity and mitochondrial membrane potential were evaluated. H/SD-induced MSCs apoptosis and caspase-3 activation were attenuated by gAPN in a concentration-dependent manner. gAPN increased Bcl-2 and decreased Bax expressions. The loss of mitochondrial membrane potential induced by H/SD was also abolished by gAPN. The protective effect of gAPN was significantly attenuated after the knockdown of AdipoR1 rather than AdipoR2. Moreover, Compound C partly suppressed the anti-apoptotic effect of gAPN. gAPN inhibits H/SD-induced apoptosis in MSCs via AdipoR1-mediated pathway, possibly linked to the activation of AMPK. gAPN may be a novel survival factor for MSCs in the ischemic engraftment environment. © 2016 The Author(s) Published by S. Karger AG, Basel.

  9. The PP4R1 sub-unit of protein phosphatase PP4 is essential for inhibition of NF-κB by merkel polyomavirus small tumour antigen.

    Abdul-Sada, Hussein; Müller, Marietta; Mehta, Rajni; Toth, Rachel; Arthur, J Simon C; Whitehouse, Adrian; Macdonald, Andrew

    2017-04-11

    Merkel cell carcinoma (MCC) is a highly aggressive skin cancer with a high metastatic potential. The majority of MCC cases are caused by the Merkel cell polyomavirus (MCPyV), through expression of the virus-encoded tumour antigens. Whilst mechanisms attributing tumour antigen expression to transformation are being uncovered, little is known of the mechanisms by which MCPyV persists in the host. We previously identified the MCPyV small T antigen (tAg) as a novel inhibitor of nuclear factor kappa B (NF-kB) signalling and a modulator of the host anti-viral response. Here we demonstrate that regulation of NF-kB activation involves a previously undocumented interaction between tAg and regulatory sub-unit 1 of protein phosphatase 4 (PP4R1). Formation of a complex with PP4R1 and PP4c is required to bridge MCPyV tAg to the NEMO adaptor protein, allowing deactivation of the NF-kB pathway. Mutations in MCPyV tAg that fail to interact with components of this complex, or siRNA depletion of PP4R1, prevents tAg-mediated inhibition of NF-kB and pro-inflammatory cytokine production. Comparison of tAg binding partners from other human polyomavirus demonstrates that interactions with NEMO and PP4R1 are unique to MCPyV. Collectively, these data identify PP4R1 as a novel target for virus subversion of the host anti-viral response.

  10. Adapting radiotherapy to hypoxic tumours

    Malinen, Eirik; Søvik, Åste; Hristov, Dimitre; Bruland, Øyvind S.; Rune Olsen, Dag

    2006-10-01

    and step-and-shoot intensity levels). Simulated random and systematic errors in the pO2-related images reduced the TCP for the non-uniform dose prescription. In conclusion, improved tumour control of hypoxic tumours by dose redistribution may be expected following hypoxia imaging, tumour control predictions, inverse treatment planning and IMRT.

  11. Adapting radiotherapy to hypoxic tumours

    Malinen, Eirik; Soevik, Aste; Hristov, Dimitre; Bruland, Oeyvind S; Olsen, Dag Rune

    2006-01-01

    (fields and step-and-shoot intensity levels). Simulated random and systematic errors in the pO 2 -related images reduced the TCP for the non-uniform dose prescription. In conclusion, improved tumour control of hypoxic tumours by dose redistribution may be expected following hypoxia imaging, tumour control predictions, inverse treatment planning and IMRT

  12. Inhibition of proliferative activity in tissue culture in vivo of esophagus and stomach tumour cells under preoperative irradiation

    Zinchenko, V.A.; Okulov, L.V.; Gol'dshmid, B.Ya.

    1988-01-01

    Inhibition of proliferative activity of tumor cells as a result of radiation effect. Tumor tissue taken from patiets with preoperative tumor irradiation by 30 Gy cumulative dose (5 Gy per a session) and from patients whose tumors were not subjected to irradiation (control) was used. The tumor tissue was cultivated in the diffusion chamber and then implanted to the abdominal cavity of the non-inbred male rats. On preparations in the growth area pathomorphological changes were evaluated, the share of mitotically dividing and DNA-synthesizing cells was determined. The absence of growth area around the explant, obvious reduction of mitotic activity and DNA-synthesizing function of cells in preparations of irradiated tumors in 88 % of cases testify to the inhibition of the stomach cardial section and esophagus tumor tissue repopulation after radiation effect. The investigation results confirm the advisability of preoperative irradiation of patients with tumors of the given localization

  13. Menadione and ethacrynic acid inhibit the hypoxia-inducible factor (HIF) pathway by disrupting HIF-1α interaction with p300.

    Na, Yu-Ran; Han, Ki-Cheol; Park, Hyunsung; Yang, Eun Gyeong

    2013-05-17

    Hypoxia is a general characteristic of most solid malignancies and intimately related to neoplastic diseases and cancer progression. Homeostatic response to hypoxia is primarily mediated by hypoxia inducible factor (HIF)-1α that elicits transcriptional activity through recruitment of the CREB binding protein (CBP)/p300 coactivator. Targeted blockade of HIF-1α binding to CBP/p300 would thus constitute a novel approach for cancer treatment by suppressing tumor angiogenesis and metastasis. Here, we identified inhibitors against the interaction between HIF-1α and p300 by a fluorescence polarization-based assay employing a fluorescently-labeled peptide containing the C-terminal activation domain of HIF-1α. Two small molecule inhibitors, menadione (MD) and ethacrynic acid (EA), were found to decrease expression of luciferase under the control of hypoxia-responsive elements in hypoxic cells as well as to efficiently block the interaction between the full-length HIF-1α and p300. While these compounds did not alter the expression level of HIF-1α, they down-regulated expression of a HIF-1α target vascular endothelial growth factor (VEGF) gene. Considering hypoxia-induced VEGF expression leading to highly aggressive tumor growth, MD and EA may provide new scaffolds for development of tumor therapeutic reagents as well as tools for a better understanding of HIF-1α-mediated hypoxic regulation. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. In vitro ischemia suppresses hypoxic induction of hypoxia-inducible factor-1α by inhibition of synthesis and not enhanced degradation.

    Karuppagounder, Saravanan S; Basso, Manuela; Sleiman, Sama F; Ma, Thong C; Speer, Rachel E; Smirnova, Natalya A; Gazaryan, Irina G; Ratan, Rajiv R

    2013-08-01

    Hypoxia-inducible factor (HIF) mediates a broad, conserved adaptive response to hypoxia, and the HIF pathway is a potential therapeutic target in cerebral ischemia. This study investigated the mechanism by which in vitro ischemia (oxygen-glucose deprivation; OGD) affects canonical hypoxic HIF-1α stabilization. We validated the use of a reporter containing the oxygen-dependent degradation domain of HIF-1α fused to firefly luciferase (ODD-luc) to monitor quantitatively distinct biochemical events leading to hypoxic HIF-1α expression or stabilization in a human neuroblastoma cell line (SH-SY5Y). When OGD was imposed following a 2-hr hypoxic stabilization of ODD-luc, the levels of the reporter were reduced, consistent with prior models proposing that OGD enhances HIF prolylhydroxylase (PHD) activity. Surprisingly, PHD inhibitors and proteasome inhibitors do not stabilize ODD-luc in OGD. Furthermore, OGD does not affect the half-life of ODD-luc protein following hypoxia, suggesting that OGD abrogates hypoxic HIF-1α induction by reducing HIF-1α synthesis rather than by enhancing its degradation. We observed ATP depletion under OGD vs. hypoxia and propose that ATP depletion enhances translational suppression, overcoming the selective synthesis of HIF concurrent with global decreases in protein synthesis in hypoxia. Taken together, these findings biochemically characterize a practical reporter for monitoring HIF-1α levels and support a novel model for HIF regulation in an in vitro model of human ischemia. Copyright © 2013 Wiley Periodicals, Inc.

  15. Oxidative stress by ascorbate/menadione association kills K562 human chronic myelogenous leukaemia cells and inhibits its tumour growth in nude mice.

    Verrax, Julien; Stockis, Julie; Tison, Aurélie; Taper, Henryk S; Calderon, Pedro Buc

    2006-09-14

    The effect of oxidative stress induced by the ascorbate/menadione-redox association was examined in K562 cells, a human erythromyeloid leukaemia cell line. Our results show that ascorbate enhances menadione redox cycling, leading to the formation of intracellular reactive oxygen species (as shown by dihydrorhodamine 123 oxidation). The incubation of cells in the presence of both ascorbate/menadione and aminotriazole, a catalase inhibitor, resulted in a strong decrease of cell survival, reinforcing the role of H(2)O(2) as the main oxidizing agent killing K562 cells. This cell death was not caspase-3-dependent. Indeed, neither procaspase-3 and PARP were processed and only a weak cytochrome c release was observed. Moreover, we observed only 23% of cells with depolarized mitochondria. In ascorbate/menadione-treated cells, DNA fragmentation was observed without any sign of chromatin condensation (DAPI and TUNEL tests). The cell demise by ascorbate/menadione is consistent with a necrosis-like cell death confirmed by both cytometric profile of annexin-V/propidium iodide labeled cells and by light microscopy examination. Finally, we showed that a single i.p. administration of the association of ascorbate and menadione is able to inhibit the growth of K562 cells by about 60% (in both tumour size and volume) in an immune-deficient mice model. Taken together, these results reinforced our previous claims about a potential application of the ascorbate/menadione association in cancer therapy.

  16. Folate-targeted amphiphilic cyclodextrin nanoparticles incorporating a fusogenic peptide deliver therapeutic siRNA and inhibit the invasive capacity of 3D prostate cancer tumours.

    Evans, James C; Malhotra, Meenakshi; Sweeney, Katrina; Darcy, Raphael; Nelson, Colleen C; Hollier, Brett G; O'Driscoll, Caitriona M

    2017-10-30

    The main barrier to the development of an effective RNA interference (RNAi) therapy is the lack of a suitable delivery vector. Modified cyclodextrins have emerged in recent years for the delivery of siRNA. In the present study, a folate-targeted amphiphilic cyclodextrin was formulated using DSPE-PEG 5000 -folate to target prostate cancer cells. The fusogenic peptide GALA was included in the formulation to aid in the endosomal release of siRNA. Targeted nanoparticles were less than 200nm in size with a neutral surface charge. The complexes were able to bind siRNA and protect it from serum nucleases. Incubation with excess free folate resulted in a significant decrease in the uptake of targeted nanoparticles in LNCaP and PC3 cells, both of which have been reported to have differing pathways of folate uptake. There was a significant reduction in the therapeutic targets, ZEB1 and NRP1 at mRNA and protein level following treatment with targeted complexes. In preliminary functional assays using 3D spheroids, treatment of PC3 tumours with targeted complexes with ZEB1 and NRP1 siRNA resulted in more compact colonies relative to the untargeted controls and inhibited infiltration into the Matrigel™ layer. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Established Models and New Paradigms for Hypoxia-Driven Cancer-Associated Bone Disease

    Cox, Thomas R.; Erler, Janine T.; Rumney, Robin M.H.

    2018-01-01

    -driven effects in the primary tumour are wide ranging including changes in gene expression, dysregulation of signalling pathways, resistance to chemotherapy, neovascularisation, increased tumour cell proliferation and migration. Paget’s seed and soil theory states that for a metastasising tumour cell ‘the seed...... metastases. This review describes the roles of hypoxia in primary tumour progression to metastasis, with a focus on key signalling pathways and treatment options to reduce patient morbidity and increase survival....

  18. Inhibition of hypoxia-inducible factor 1 with acriflavine sensitizes hypoxic tumor cells to photodynamic therapy with zinc phthalocyanine-encapsulating cationic liposomes

    Broekgaarden, Mans; Weijer, Ruud; Krekorian, Massis; van den IJssel, Bas; Kos, Milan; Alles, Lindy K.; van Wijk, Albert C.; Bikadi, Zsolt; Hazai, Eszter; van Gulik, Thomas M.; Heger, Michal

    2016-01-01

    Photodynamic therapy (PDT) is a tumor treatment modality in which a tumorlocalized photosensitizer is excited with light, which results in local production of reactive oxygen species, destruction of tumor vasculature, tumor hypoxia, tumor cell death, and induction of an anti-tumor immune response.

  19. Hypoxia: From Placental Development to Fetal Programming.

    Fajersztajn, Lais; Veras, Mariana Matera

    2017-10-16

    Hypoxia may influence normal and different pathological processes. Low oxygenation activates a variety of responses, many of them regulated by hypoxia-inducible factor 1 complex, which is mostly involved in cellular control of O 2 consumption and delivery, inhibition of growth and development, and promotion of anaerobic metabolism. Hypoxia plays a significant physiological role in fetal development; it is involved in different embryonic processes, for example, placentation, angiogenesis, and hematopoiesis. More recently, fetal hypoxia has been associated directly or indirectly with fetal programming of heart, brain, and kidney function and metabolism in adulthood. In this review, the role of hypoxia in fetal development, placentation, and fetal programming is summarized. Hypoxia is a basic mechanism involved in different pregnancy disorders and fetal health developmental complications. Although there are scientific data showing that hypoxia mediates changes in the growth trajectory of the fetus, modulates gene expression by epigenetic mechanisms, and determines the health status later in adulthood, more mechanistic studies are needed. Furthermore, if we consider that intrauterine hypoxia is not a rare event, and can be a consequence of unavoidable exposures to air pollution, nutritional deficiencies, obesity, and other very common conditions (drug addiction and stress), the health of future generations may be damaged and the incidence of some diseases will markedly increase as a consequence of disturbed fetal programming. Birth Defects Research 109:1377-1385, 2017.© 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  20. Polysaccharide Agaricus blazei Murill stimulates myeloid derived suppressor cell differentiation from M2 to M1 type, which mediates inhibition of tumour immune-evasion via the Toll-like receptor 2 pathway.

    Liu, Yi; Zhang, Lingyun; Zhu, Xiangxiang; Wang, Yuehua; Liu, WenWei; Gong, Wei

    2015-11-01

    Gr-1(+) CD11b(+) myeloid-derived suppressor cells (MDSCs) accumulate in tumor-bearing animals and play a critical negative role during tumor immunotherapy. Strategies for inhibition of MDSCs are expected to improve cancer immunotherapy. Polysaccharide Agaricus blazei Murill (pAbM) has been found to have anti-cancer activity, but the underlying mechanism of this is poorly understood. Here, pAbM directly activated the purified MDSCs through inducing the expression of interleukin-6 (IL-6), IL-12, tumour necrosis factor and inducible nitric oxide synthase (iNOS), CD86, MHC II, and pSTAT1 of it, and only affected natural killer and T cells in the presence of Gr-1(+) CD11b(+) monocytic MDSCs. On further analysis, we demonstrated that pAbM could selectively block the Toll-like receptor 2 (TLR2) signal of Gr-1(+) CD11b(+) MDSCs and increased their M1-type macrophage characteristics, such as producing IL-12, lowering expression of Arginase 1 and increasing expression of iNOS. Extensive study showed that Gr-1(+) CD11b(+) MDSCs by pAbM treatment had less ability to convert the CD4(+) CD25(-) cells into CD4(+) CD25(+) phenotype. Moreover, result from selective depletion of specific cell populations in xenograft mice model suggested that the anti-tumour effect of pAbM was dependent on Gr-1(+ ) CD11b(+) monocytes, nether CD8(+) T cells nor CD4(+) T cells. In addition to, pAbM did not inhibit tumour growth in TLR2(-/-) mice. All together, these results suggested that pAbM, a natural product commonly used for cancer treatment, was a specific TLR2 agonist and had potent anti-tumour effects through the opposite of the suppressive function of Gr-1(+) CD11b(+) MDSCs. © 2015 John Wiley & Sons Ltd.

  1. Hypoxia induces adipogenic differentitation of myoblastic cell lines

    Itoigawa, Yoshiaki [Tohoku University School of Medicine, Sendai (Japan); Juntendo University School of Medicine, Tokyo (Japan); Kishimoto, Koshi N., E-mail: kishimoto@med.tohoku.ac.jp [Tohoku University School of Medicine, Sendai (Japan); Okuno, Hiroshi; Sano, Hirotaka [Tohoku University School of Medicine, Sendai (Japan); Kaneko, Kazuo [Juntendo University School of Medicine, Tokyo (Japan); Itoi, Eiji [Tohoku University School of Medicine, Sendai (Japan)

    2010-09-03

    Research highlights: {yields} C2C12 and G8 myogenic cell lines treated by hypoxia differentiate into adipocytes. {yields} The expression of C/EBP{beta}, {alpha} and PPAR{gamma} were increased under hypoxia. {yields} Myogenic differentiation of C2C12 was inhibited under hypoxia. -- Abstract: Muscle atrophy usually accompanies fat accumulation in the muscle. In such atrophic conditions as back muscles of kyphotic spine and the rotator cuff muscles with torn tendons, blood flow might be diminished. It is known that hypoxia causes trans-differentiation of mesenchymal stem cells derived from bone marrow into adipocytes. However, it has not been elucidated yet if hypoxia turned myoblasts into adipocytes. We investigated adipogenesis in C2C12 and G8 murine myogenic cell line treated by hypoxia. Cells were also treated with the cocktail of insulin, dexamethasone and IBMX (MDI), which has been known to inhibit Wnt signaling and promote adipogenesis. Adipogenic differentiation was seen in both hypoxia and MDI. Adipogenic marker gene expression was assessed in C2C12. CCAAT/enhancer-binding protein (C/EBP) {beta}, {alpha} and peroxisome proliferator activating receptor (PPAR) {gamma} were increased by both hypoxia and MDI. The expression profile of Wnt10b was different between hypoxia and MDI. The mechanism for adipogenesis of myoblasts in hypoxia might be regulated by different mechanism than the modification of Wnt signaling.

  2. Globular Adiponectin Inhibits the Apoptosis of Mesenchymal Stem Cells Induced by Hypoxia and Serum Deprivation via the AdipoR1-Mediated Pathway

    Xia-Qiu Tian; Yue-Jin Yang; Qing Li; Pei-Sen Huang; Xiang-Dong Li; Chen Jin; Kang Qi; Lei-Pei Jiang; Gui-Hao Chen

    2016-01-01

    Background/Aims: Poor viability of transplanted mesenchymal stem cells (MSCs) within the ischemic heart limits their therapeutic potential for cardiac repair. Globular adiponectin (gAPN) exerts anti-apoptotic effects on several types of stem cells. Herein, we investigated the effect of gAPN on the MSCs against apoptosis induced by hypoxia and serum deprivation (H/SD). Methods: MSCs exposed to H/SD conditions were treated with different concentrations of gAPN. To identify the main type of rece...

  3. The germacranolide sesquiterpene lactone neurolenin B of the medicinal plant Neurolaena lobata (L.) R.Br. ex Cass inhibits NPM/ALK-driven cell expansion and NF-κB-driven tumour intravasation.

    Unger, Christine; Kiss, Izabella; Vasas, Andrea; Lajter, Ildikó; Kramer, Nina; Atanasov, Atanas Georgiev; Nguyen, Chi Huu; Chatuphonprasert, Waranya; Brenner, Stefan; Krieger, Sigurd; McKinnon, Ruxandra; Peschel, Andrea; Kain, Renate; Saiko, Philipp; Szekeres, Thomas; Kenner, Lukas; Hassler, Melanie R; Diaz, Rene; Frisch, Richard; Dirsch, Verena M; Jäger, Walter; de Martin, Rainer; Bochkov, Valery N; Passreiter, Claus M; Peter-Vörösmarty, Barbara; Mader, Robert M; Grusch, Michael; Dolznig, Helmut; Kopp, Brigitte; Zupko, Istvan; Hohmann, Judit; Krupitza, Georg

    2015-08-15

    The t(2;5)(p23;q35) chromosomal translocation results in the expression of the fusion protein NPM/ALK that when expressed in T-lymphocytes gives rise to anaplastic large cell lymphomas (ALCL). In search of new therapy options the dichloromethane extract of the ethnomedicinal plant Neurolaena lobata (L.) R.Br. ex Cass was shown to inhibit NPM/ALK expression. Therefore, we analysed whether the active principles that were recently isolated and found to inhibit inflammatory responses specifically inhibit growth of NPM/ALK+ ALCL, leukaemia and breast cancer cells, but not of normal cells, and the intravasation through the lymphendothelial barrier. ALCL, leukaemia and breast cancer cells, and normal peripheral blood mononuclear cells (PBMCs) were treated with isolated sesquiterpene lactones and analysed for cell cycle progression, proliferation, mitochondrial activity, apoptosis, protein and mRNA expression, NF-κB and cytochrome P450 activity, 12(S)-HETE production and lymphendothelial intravasation. In vitro treatment of ALCL by neurolenin B suppressed NPM/ALK, JunB and PDGF-Rβ expression, inhibited the growth of ALCL cells late in M phase, and induced apoptosis via caspase 3 without compromising mitochondrial activity (as a measure of general exogenic toxicity). Moreover, neurolenin B attenuated tumour spheroid intravasation probably through inhibition of NF-κB and CYP1A1. Neurolenin B specifically decreased pro-carcinogenic NPM/ALK expression in ALK+ ALCL cells and, via the inhibition of NF-kB signalling, attenuated tumour intra/extravasation into the lymphatics. Hence, neurolenin B may open new options to treat ALCL and to manage early metastatic processes to which no other therapies exist. Copyright © 2015 Elsevier GmbH. All rights reserved.

  4. Molecular imaging of hypoxia in non-small-cell lung cancer

    Yip, Connie; Blower, Philip J.; Goh, Vicky; Landau, David B.; Cook, Gary J.R.

    2015-01-01

    Non-small-cell lung cancer (NSCLC) is the commonest cancer worldwide but survival remains poor with a high risk of relapse, particularly after nonsurgical treatment. Hypoxia is present in a variety of solid tumours, including NSCLC. It is associated with treatment resistance and a poor prognosis, although when recognised may be amenable to different treatment strategies. Thus, noninvasive assessment of intratumoral hypoxia could be used to stratify patients for modification of subsequent treatment to improve tumour control. Molecular imaging approaches targeting hypoxic cells have shown some early success in the clinical setting. This review evaluates the evidence for hypoxia imaging using PET in NSCLC and explores its potential clinical utility. (orig.)

  5. Molecular imaging of hypoxia in non-small-cell lung cancer

    Yip, Connie [King' s College London, St Thomas' Hospital, Department of Cancer Imaging, Division of Imaging Sciences and Biomedical Engineering, London (United Kingdom); National Cancer Centre, Department of Radiation Oncology, Singapore (Singapore); St Thomas' Hospital, Imaging 2, London (United Kingdom); Blower, Philip J. [King' s College London, St Thomas' Hospital, Department of Imaging Chemistry and Biology, Division of Imaging Sciences and Biomedical Engineering, London (United Kingdom); Goh, Vicky [King' s College London, St Thomas' Hospital, Department of Cancer Imaging, Division of Imaging Sciences and Biomedical Engineering, London (United Kingdom); St Thomas' Hospital, Department of Radiology, Guy' s and St Thomas' NHS Foundation Trust, London (United Kingdom); Landau, David B. [King' s College London, St Thomas' Hospital, Department of Cancer Imaging, Division of Imaging Sciences and Biomedical Engineering, London (United Kingdom); St Thomas' Hospital, Department of Clinical Oncology, Guy' s and St Thomas' NHS Foundation Trust, London (United Kingdom); Cook, Gary J.R. [King' s College London, St Thomas' Hospital, Department of Cancer Imaging, Division of Imaging Sciences and Biomedical Engineering, London (United Kingdom); St Thomas' Hospital, Clinical PET Imaging Centre, Guy' s and St Thomas' NHS Foundation Trust, London (United Kingdom)

    2015-05-01

    Non-small-cell lung cancer (NSCLC) is the commonest cancer worldwide but survival remains poor with a high risk of relapse, particularly after nonsurgical treatment. Hypoxia is present in a variety of solid tumours, including NSCLC. It is associated with treatment resistance and a poor prognosis, although when recognised may be amenable to different treatment strategies. Thus, noninvasive assessment of intratumoral hypoxia could be used to stratify patients for modification of subsequent treatment to improve tumour control. Molecular imaging approaches targeting hypoxic cells have shown some early success in the clinical setting. This review evaluates the evidence for hypoxia imaging using PET in NSCLC and explores its potential clinical utility. (orig.)

  6. Sorafenib blocks tumour growth, angiogenesis and metastatic potential in preclinical models of osteosarcoma through a mechanism potentially involving the inhibition of ERK1/2, MCL-1 and ezrin pathways

    Ferrari Stefano

    2009-12-01

    Full Text Available Abstract Background Osteosarcoma (OS is the most common primary bone tumour in children and young adults. Despite improved prognosis, metastatic or relapsed OS remains largely incurable and no significant improvement has been observed in the last 20 years. Therefore, the search for alternative agents in OS is mandatory. Results We investigated phospho-ERK 1/2, MCL-1, and phospho-Ezrin/Radixin/Moesin (P-ERM as potential therapeutic targets in OS. Activation of these pathways was shown by immunohistochemistry in about 70% of cases and in all OS cell lines analyzed. Mutational analysis revealed no activating mutations in KRAS whereas BRAF gene was found to be mutated in 4/30 OS samples from patients. Based on these results we tested the multi-kinase inhibitor sorafenib (BAY 43-9006 in preclinical models of OS. Sorafenib inhibited OS cell line proliferation, induced apoptosis and downregulated P-ERK1/2, MCL-1, and P-ERM in a dose-dependent manner. The dephosphorylation of ERM was not due to ERK inhibition. The downregulation of MCL-1 led to an increase in apoptosis in OS cell lines. In chick embryo chorioallantoic membranes, OS supernatants induced angiogenesis, which was blocked by sorafenib and it was also shown that sorafenib reduced VEGF and MMP2 production. In addition, sorafenib treatment dramatically reduced tumour volume of OS xenografts and lung metastasis in SCID mice. Conclusion In conclusion, ERK1/2, MCL-1 and ERM pathways are shown to be active in OS. Sorafenib is able to inhibit their signal transduction, both in vitro and in vivo, displaying anti-tumoural activity, anti-angiogenic effects, and reducing metastatic colony formation in lungs. These data support the testing of sorafenib as a potential therapeutic option in metastatic or relapsed OS patients unresponsive to standard treatments.

  7. Hypoxia stimulates invasion and migration of human cervical cancer ...

    Here we show that hypoxiaincreases tumour cell invasion and migration by the modulation of Rab11, an important molecule for vesicular trafficking.In our study, we found that Rab11, together with the activation of Rac1, could stimulate invasion and migration of cervicalcancer cell lines HeLa/SiHa in hypoxia. Activation of ...

  8. VEGF-A promotes lymphoma tumour growth by activation of STAT proteins and inhibition of p27(KIP1) via paracrine mechanisms

    Roorda, Berber D.; ter Elst, Arja; Scherpen, Frank J. G.; Meemusen-de Boer, Tiny G. J.; Kamps, Willem A.; de Bont, Eveline S. J. M.

    Increased levels of circulating VEGF-A have been demonstrated in patients with non-Hodgkin lymphoma (NHL) and are associated with progressive disease and poor clinical outcome. We investigated the role of VEGF-A in lymphoma tumour growth on a molecular level in order to identify the mechanism of

  9. Gastric Calcifying Fibrous Tumour

    Tan Attila

    2006-01-01

    Full Text Available Intramucosal gastric tumours are most commonly found to be gastrointestinal stromal tumours or leiomyomas (smooth muscle tumours; however, a variety of other uncommon mesenchymal tumours can occur in the stomach wall. A rare benign calcifying fibrous tumour is reported and the endoscopic appearance, ultrasound findings and morphology are documented. A review of the literature found only two similar cases.

  10. Inhibition of mitochondrial respiration by the anticancer agent 2-methoxyestradiol

    Hagen, Thilo; D'Amico, Gabriela; Quintero, Marisol; Palacios-Callender, Miriam; Hollis, Veronica; Lam, Francis; Moncada, Salvador

    2004-01-01

    2-Methoxyestradiol (2ME2), a naturally occurring metabolite of estradiol, is known to have antiproliferative, antiangiogenic, and proapoptotic activity. Mechanistically, 2ME2 has been shown to downregulate hypoxia-inducible factor 1α (HIF1α) and to induce apoptosis in tumour cells by generating reactive oxygen species (ROS). In this study we report that 2ME2 inhibits mitochondrial respiration in both intact cells and submitochondrial particles, and that this effect is due to inhibition of complex I of the mitochondrial electron transport chain (ETC). The prevention by 2ME2 of hypoxia-induced stabilisation of HIF1α in HEK293 cells was found not to be due to an effect on HIF1α synthesis but rather to an effect on protein degradation. This is in agreement with our recent observation using other inhibitors of mitochondrial respiration which bring about rapid degradation of HIF1α in hypoxia due to increased availability of oxygen and reactivation of prolyl hydroxylases. The concentrations of 2ME2 that inhibited complex I also induced the generation of ROS. 2ME2 did not, however, cause generation of ROS in 143B rho - cells, which lack a functional mitochondrial ETC. We conclude that inhibition of mitochondrial respiration explains, at least in part, the effect of 2ME2 on hypoxia-dependent HIF1α stabilisation and cellular ROS production. Since these actions of 2ME2 occur at higher concentrations than those known to inhibit cell proliferation, it remains to be established whether they contribute to its therapeutic effect

  11. Hypoxia- and radiation-inducible, breast cell-specific targeting of retroviral vectors

    Lipnik, Karoline; Greco, Olga; Scott, Simon; Knapp, Elzbieta; Mayrhofer, Elisabeth; Rosenfellner, Doris; Guenzburg, Walter H.; Salmons, Brian; Hohenadl, Christine

    2006-01-01

    To facilitate a more efficient radiation and chemotherapy of mammary tumours, synthetic enhancer elements responsive to hypoxia and ionizing radiation were coupled to the mammary-specific minimal promoter of the murine whey acidic protein (WAP) encoding gene. The modified WAP promoter was introduced into a retroviral promoter conversion (ProCon) vector. Expression of a transduced reporter gene in response to hypoxia and radiation was analysed in stably infected mammary cancer cell lines and an up to 9-fold increase in gene expression demonstrated in comparison to the respective basic vector. Expression analyses in vitro, moreover, demonstrated a widely preserved mammary cell-specific promoter activity. For in vivo analyses, xenograft tumours consisting of infected human mammary adenocarcinoma cells were established in SCID/beige mice. Immunohistochemical analyses demonstrated a hypoxia-specific, markedly increased WAP promoter-driven expression in these tumours. Thus, this retroviral vector will facilitate a targeted gene therapeutic approach exploiting the unique environmental condition in solid tumours

  12. Modelling and simulation of the influence of acute and chronic hypoxia on [18F]fluoromisonidazole PET imaging.

    Monnich, D.; Troost, E.G.C.; Kaanders, J.H.A.M.; Oyen, W.J.G.; Alber, M.; Thorwarth, D.

    2012-01-01

    Tumour hypoxia can be assessed by positron emission tomography (PET) using radiotracers like [(18)F]fluoromisonidazole (Fmiso). The purpose of this work was to independently investigate the influence of chronic and acute hypoxia on the retention of Fmiso on the microscale. This was approached by

  13. RBC-coupled tPA prevents cerebrovasodilatory impairment and tissue injury in pediatric cerebral hypoxia/ischemia through inhibition of ERK MAPK unregulation

    Ganguly, Kumkum [Los Alamos National Laboratory; Armstead, William M [U PENNSYLVANIA; Kiessling, J W [U PENNSYLVANIA; Chen, Xiao - Han [U PENNSYLVANIA; Smith, Douglas H [U PENNSYLVANA; Higazi, Abd Ar [U PENNSYLVANIA; Cines, Douglas B [U PENNSYLVANIA; Bdeir, Khalil [U PENNSYLVANIA; Zaitsev, Sergei [U PENNSYLVANIA; Muzykantov, Vladimir R [U PENNSYLVANIA

    2008-01-01

    Babies experience hypoxia (H) and ischemia (I) from stroke. The only approved treatment for stroke is fibrinolytic therapy with tissue-type plasminogen activator (tPA). However, tPA potentiates H/I-induced impairment of responses to cerebrovasodilators such as hypercapnia and hypotension, and blockade of tPA-mediated vasoactivity prevents this deleterious effect. Coupling tPA to RBCs reduces its CNS toxicity through spatially confining the drug to the vasculature. Mitogen activated protein kinase (MAPK), a family of at least 3 kinases, is upregulated after H/I. In this study we determined if RBC-tPA given before or after cerebral H/I would preserve responses to cerebrovasodilators and prevent neuronal injury mediated through the ERK MAPK pathway. Animals given RBC-tPA maintained responses to cerebrovasodilators at levels equivalent to pre-H/I values. CSF and brain parenchymal ERK MAPK was elevated by H/I and this upregulation was potentiated by tPA, but blunted by RBC-tPA. U 0126, an ERK MAPK antagonist, also maintained cerebrovasodilation post H/I. Neuronal degeneration in CA1 hippocampus and parietal cortex after H/I was exacerbated by tPA, but ameliorated by RBC-tPA and U 0126. These data suggest that coupling tPA to RBCs may offer a novel approach towards increasing the benefit/risk ratio of thrombolytic therapy for CNS disorders associated with H/I.

  14. Hypoxia and hypoglycaemia in Ewing's sarcoma and osteosarcoma: regulation and phenotypic effects of Hypoxia-Inducible Factor

    Knowles, Helen J; Schaefer, Karl-Ludwig; Dirksen, Uta; Athanasou, Nicholas A

    2010-01-01

    Hypoxia regulates gene expression via the transcription factor HIF (Hypoxia-Inducible Factor). Little is known regarding HIF expression and function in primary bone sarcomas. We describe HIF expression and phenotypic effects of hypoxia, hypoglycaemia and HIF in Ewing's sarcoma and osteosarcoma. HIF-1α and HIF-2α immunohistochemistry was performed on a Ewing's tumour tissue array. Ewing's sarcoma and osteosarcoma cell lines were assessed for HIF pathway induction by Western blot, luciferase assay and ELISA. Effects of hypoxia, hypoglycaemia and isoform-specific HIF siRNA were assessed on proliferation, apoptosis and migration. 17/56 Ewing's tumours were HIF-1α-positive, 15 HIF-2α-positive and 10 positive for HIF-1α and HIF-2α. Expression of HIF-1α and cleaved caspase 3 localised to necrotic areas. Hypoxia induced HIF-1α and HIF-2α in Ewing's and osteosarcoma cell lines while hypoglycaemia specifically induced HIF-2α in Ewing's. Downstream transcription was HIF-1α-dependent in Ewing's sarcoma, but regulated by both isoforms in osteosarcoma. In both cell types hypoglycaemia reduced cellular proliferation by ≥ 45%, hypoxia increased apoptosis and HIF siRNA modulated hypoxic proliferation and migration. Co-localisation of HIF-1α and necrosis in Ewing's sarcoma suggests a role for hypoxia and/or hypoglycaemia in in vivo induction of HIF. In vitro data implicates hypoxia as the primary HIF stimulus in both Ewing's and osteosarcoma, driving effects on proliferation and apoptosis. These results provide a foundation from which to advance understanding of HIF function in the pathobiology of primary bone sarcomas

  15. Hypoxia and hypoglycaemia in Ewing's sarcoma and osteosarcoma: regulation and phenotypic effects of Hypoxia-Inducible Factor

    Dirksen Uta

    2010-07-01

    Full Text Available Abstract Background Hypoxia regulates gene expression via the transcription factor HIF (Hypoxia-Inducible Factor. Little is known regarding HIF expression and function in primary bone sarcomas. We describe HIF expression and phenotypic effects of hypoxia, hypoglycaemia and HIF in Ewing's sarcoma and osteosarcoma. Methods HIF-1α and HIF-2α immunohistochemistry was performed on a Ewing's tumour tissue array. Ewing's sarcoma and osteosarcoma cell lines were assessed for HIF pathway induction by Western blot, luciferase assay and ELISA. Effects of hypoxia, hypoglycaemia and isoform-specific HIF siRNA were assessed on proliferation, apoptosis and migration. Results 17/56 Ewing's tumours were HIF-1α-positive, 15 HIF-2α-positive and 10 positive for HIF-1α and HIF-2α. Expression of HIF-1α and cleaved caspase 3 localised to necrotic areas. Hypoxia induced HIF-1α and HIF-2α in Ewing's and osteosarcoma cell lines while hypoglycaemia specifically induced HIF-2α in Ewing's. Downstream transcription was HIF-1α-dependent in Ewing's sarcoma, but regulated by both isoforms in osteosarcoma. In both cell types hypoglycaemia reduced cellular proliferation by ≥ 45%, hypoxia increased apoptosis and HIF siRNA modulated hypoxic proliferation and migration. Conclusions Co-localisation of HIF-1α and necrosis in Ewing's sarcoma suggests a role for hypoxia and/or hypoglycaemia in in vivo induction of HIF. In vitro data implicates hypoxia as the primary HIF stimulus in both Ewing's and osteosarcoma, driving effects on proliferation and apoptosis. These results provide a foundation from which to advance understanding of HIF function in the pathobiology of primary bone sarcomas.

  16. Hypoxia and hypoglycaemia in Ewing's sarcoma and osteosarcoma: regulation and phenotypic effects of Hypoxia-Inducible Factor.

    Knowles, Helen J; Schaefer, Karl-Ludwig; Dirksen, Uta; Athanasou, Nicholas A

    2010-07-16

    Hypoxia regulates gene expression via the transcription factor HIF (Hypoxia-Inducible Factor). Little is known regarding HIF expression and function in primary bone sarcomas. We describe HIF expression and phenotypic effects of hypoxia, hypoglycaemia and HIF in Ewing's sarcoma and osteosarcoma. HIF-1alpha and HIF-2alpha immunohistochemistry was performed on a Ewing's tumour tissue array. Ewing's sarcoma and osteosarcoma cell lines were assessed for HIF pathway induction by Western blot, luciferase assay and ELISA. Effects of hypoxia, hypoglycaemia and isoform-specific HIF siRNA were assessed on proliferation, apoptosis and migration. 17/56 Ewing's tumours were HIF-1alpha-positive, 15 HIF-2alpha-positive and 10 positive for HIF-1alpha and HIF-2alpha. Expression of HIF-1alpha and cleaved caspase 3 localised to necrotic areas. Hypoxia induced HIF-1alpha and HIF-2alpha in Ewing's and osteosarcoma cell lines while hypoglycaemia specifically induced HIF-2alpha in Ewing's. Downstream transcription was HIF-1alpha-dependent in Ewing's sarcoma, but regulated by both isoforms in osteosarcoma. In both cell types hypoglycaemia reduced cellular proliferation by >or= 45%, hypoxia increased apoptosis and HIF siRNA modulated hypoxic proliferation and migration. Co-localisation of HIF-1alpha and necrosis in Ewing's sarcoma suggests a role for hypoxia and/or hypoglycaemia in in vivo induction of HIF. In vitro data implicates hypoxia as the primary HIF stimulus in both Ewing's and osteosarcoma, driving effects on proliferation and apoptosis. These results provide a foundation from which to advance understanding of HIF function in the pathobiology of primary bone sarcomas.

  17. Migraine induced by hypoxia

    Arngrim, Nanna; Schytz, Henrik Winther; Britze, Josefine

    2016-01-01

    in the visual cortex were measured by proton magnetic resonance spectroscopy. The circumference of cranial arteries was measured by 3 T high-resolution magnetic resonance angiography. Hypoxia induced migraine-like attacks in eight patients compared to one patient after sham (P = 0.039), aura in three...... and possible aura in 4 of 15 patients. Hypoxia did not change glutamate concentration in the visual cortex compared to sham, but increased lactate concentration (P = 0.028) and circumference of the cranial arteries (P ... suggests that hypoxia may provoke migraine headache and aura symptoms in some patients. The mechanisms behind the migraine-inducing effect of hypoxia should be further investigated....

  18. Inhibition of hypoxia inducible factor-1alpha by dihydroxyphenylethanol, a product from olive oil, blocks microsomal prostaglandin-E synthase-1/vascular endothelial growth factor expression and reduces tumor angiogenesis.

    Terzuoli, Erika; Donnini, Sandra; Giachetti, Antonio; Iñiguez, Miguel A; Fresno, Manuel; Melillo, Giovanni; Ziche, Marina

    2010-08-15

    2-(3,4-dihydroxyphenil)-ethanol (DPE), a polyphenol present in olive oil, has been found to attenuate the growth of colon cancer cells, an effect presumably related to its anti-inflammatory activity. To further explore the effects of DPE on angiogenesis and tumor growth we investigated the in vivo efficacy of DPE in a HT-29 xenograft model and in vitro activities in colon cancer cells exposed to interleukin-1beta (IL-1beta) and prostaglandin E-2 (PGE-2). DPE (10 mg/kg/day for 14 days) inhibited tumor growth, reducing vessel lumina and blood perfusion to tumor, and diminished expression of hypoxia inducible factor-1alpha (HIF-1alpha), vascular endothelial growth factor (VEGF), and microsomal prostaglandin-E synthase-1 (mPGEs-1). In vitro, DPE (100 mumol/L) neither affected cell proliferation nor induced apoptosis in HT-29 and WiDr cells. DPE prevented the IL-1beta-mediated increase of mPGEs-1 expression and PGE-2 generation, as it did the silencing of HIF-1alpha. Moreover, DPE blocked mPGEs-1-dependent expression of VEGF and inhibited endothelial sprouting induced by tumor cells in a coculture system. PGE-2 triggers a feed-forward loop involving HIF-1alpha, which impinges on mPGEs-1 and VEGF expression, events prevented by DPE via extracellular signal-related kinase 1/2. The reduction of PGE-2 and VEGF levels, caused by DPE, was invariably associated with a marked decrease in HIF-1alpha expression and activity, independent of proteasome activity, indicating that the DPE effects on tumor growth and angiogenesis are dependent on the inhibition of HIF-1alpha translation. We show that the in vivo DPE antitumor effect is associated with anti-inflammatory and antiangiogenic activities resulting from the downregulation of the HIF-1alpha/mPGEs-1/VEGF axis.

  19. Therapy for minimal residual tumour disease: beta-galactosylceramide inhibits growth of recurrent HPV16-associated neoplasms after surgery and chemotherapy

    Šímová, Jana; Indrová, Marie; Bieblová, Jana; Mikyšková, Romana; Bubeník, Jan; Reiniš, Milan

    2010-01-01

    Roč. 126, č. 12 (2010), s. 2997-3004 ISSN 0020-7136 R&D Projects: GA ČR GA301/06/0774; GA AV ČR IAA500520807; GA ČR GA301/07/1410; GA ČR GA301/09/1024 EU Projects: European Commission(XE) 18933 - CLINIGENE Institutional research plan: CEZ:AV0Z50520514 Keywords : beta-galactosylceramide * tumour immunotherapy * NKT cells Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.926, year: 2010

  20. Selective vulnerability in brain hypoxia

    Cervos-Navarro, J.; Diemer, Nils Henrik

    1991-01-01

    Neuropathology, selective vulnerability, brain hypoxia, vascular factors, excitotoxicity, ion homeostasis......Neuropathology, selective vulnerability, brain hypoxia, vascular factors, excitotoxicity, ion homeostasis...

  1. Tumour sleuths

    Beyers, M.; Springolo, E.; Conradie, J.D.

    1986-01-01

    Hepatocellular carcinoma is a common disease in South Africa and its identification difficult. Methods for the diagnosis of this disease includes the production of hybridoma cell lines by inoculating laboratory mice with a purified human tumour-associated antigen or the antigen-containing surface membranes or the intact cells. In the diagnosis of hepatocellular carcinoma, high concentrations of serum alpha fetoprotein (AFP) can be measured by means of radioimmunoassay techniques. The need for specific methods of diagnosis and treatment of hepatocellular carcinoma led to the investigation by the Isotope Production Centre at Pelindaba into the possibility of using radiolabelled monoclonal anti-AFP for diagnosis, and later, therapy of hepatocellular carcinoma. The monoclonal antibodies can also be labelled with 131 I. Recently the Department of Nuclear Medicine of the University of the Witwatersrand is conducting diagnostic trials on patients who have given their informed consent, to assess the specificity of 131 I radiolabelled anti-AFP monoclonal antibodies to hepatocellular carcinoma cells in humans. Although the investigation is still in its infancy, monoclonal antibodies may prove to be successful non-invasive agents for detecting tumors in early stages

  2. Adnexal Tumours Of Skin

    Parate Sanjay N

    1998-01-01

    Full Text Available A total 120 cases of epidermal appendage tumours of skin were analysed and classified according to the classification provided by WHO’. Epidermal appendage tumours accounted for 12.87% of all skin tumours, of which 29.17% were benign and 70.83% were malignant. Most of the tumours (75.83% were in the head and face region. The most common tumour was basal cell epithelioma (55%.

  3. Neuronal nitric oxide synthase inhibition prevents cerebral palsy following hypoxia-ischemia in fetal rabbits: comparison between JI-8 and 7-nitroindazole.

    Yu, Lei; Derrick, Matthew; Ji, Haitao; Silverman, Richard B; Whitsett, Jennifer; Vásquez-Vivar, Jeannette; Tan, Sidhartha

    2011-01-01

    Cerebral palsy and death are serious consequences of perinatal hypoxia-ischemia (HI). Important concepts can now be tested using an animal model of cerebral palsy. We have previously shown that reactive oxygen and nitrogen species are produced in antenatal HI. A novel class of neuronal nitric oxide synthase (nNOS) inhibitors have been designed, and they ameliorate postnatal motor deficits when administered prior to the hypoxic-ischemic insult. This study asks how the new class of inhibitors, using JI-8 (K(i) for nNOS: 0.014 μM) as a representative, compare with the frequently used nNOS inhibitor 7-nitroindazole (7-NI; K(i): 0.09 ± 0.024 μM). A theoretical dose equivalent to 75 K(i) of JI-8 or equimolar 7-NI was administered to pregnant rabbit dams 30 min prior to and immediately after 40 min of uterine ischemia at 22 days gestation (70% term). JI-8 treatment resulted in a significant decrease in NOS activity (39%) in fetal brain homogenates acutely after HI, without affecting maternal blood pressure and heart rate. JI-8 treatment resulted in 33 normal kits, 2 moderately and 13 severely affected kits and 5 stillbirths, compared with 8 normal, 3 moderately affected and 5 severely affected kits and 10 stillbirths in the 7-NI group. In terms of neurobehavioral outcome, 7-NI was not different from saline treatment, while JI-8 was superior to saline and 7-NI in its protective effect (p JI-8 significantly improved the locomotion score over both saline and 7-NI scores. JI-8 was also significantly superior to saline in preserving smell, muscle tone and righting reflex function, but 7-NI did not show significant improvement. Furthermore, a 100-fold increase in the dose (15.75 μmol/kg) of 7-NI significantly decreased systolic blood pressure in the dam, while JI-8 did not. The new class of inhibitors such as JI-8 shows promise in the prevention of cerebral palsy and is superior to the previously more commonly used nNOS inhibitor. Copyright © 2011 S. Karger AG, Basel.

  4. P2X7 Receptor Antagonism Attenuates the Intermittent Hypoxia-induced Spatial Deficits in a Murine Model of Sleep Apnea Via Inhibiting Neuroinflammation and Oxidative Stress.

    Deng, Yan; Guo, Xue-Ling; Yuan, Xiao; Shang, Jin; Zhu, Die; Liu, Hui-Guo

    2015-08-20

    The mechanism of the neural injury caused by chronic intermittent hypoxia (CIH) that characterizes obstructive sleep apnea syndrome (OSAS) is not clearly known. The purpose of this study was to investigate whether P2X7 receptor (P2X7R) is responsible for the CIH-induced neural injury and the possible pathway it involves. Eight-week-old male C57BL/6 mice were used. For each exposure time point, eight mice divided in room air (RA) and IH group were assigned to the study of P2X7R expression. Whereas in the 21 days-Brilliant Blue G (BBG, a selective P2X7R antagonist) study, 48 mice were randomly divided into CIH group, BBG-treated CIH group, RA group and BBG-treated RA group. The hippocampus P2X7R expression was determined by Western blotting and real-time polymerase chain reaction (PCR). The spatial learning was analyzed by Morris water maze. The nuclear factor kappa B (NFκB) and NADPH oxidase 2 (NOX2) expressions were analyzed by Western blotting. The expressions of tumor necrosis factor α, interleukin 1β (IL-β), IL-18, and IL-6 were measured by real-time PCR. The malondialdehyde and superoxide dismutase levels were detected by colorimetric method. Cell damage was evaluated by Hematoxylin and Eosin staining and Terminal Transferase dUTP Nick-end Labeling method. The P2X7R mRNA was elevated and sustained after 3-day IH exposure and the P2X7R protein was elevated and sustained after 7-day IH exposure. In the BBG study, the CIH mice showed severer neuronal cell damage and poorer performance in the behavior test. The increased NFκB and NOX2 expressions along with the inflammation injury and oxidative stress were also observed in the CIH group. BBG alleviated CIH-induced neural injury and consequent functional deficits. The P2X7R antagonism attenuates the CIH-induced neuroinflammation, oxidative stress, and spatial deficits, demonstrating that the P2X7R is an important therapeutic target in the cognition deficits accompanied OSAS.

  5. Hypoxia-Inducible Factor 3 Is an Oxygen-Dependent Transcription Activator and Regulates a Distinct Transcriptional Response to Hypoxia

    Peng Zhang

    2014-03-01

    Full Text Available Hypoxia-inducible factors (HIFs play key roles in the cellular response to hypoxia. It is widely accepted that whereas HIF-1 and HIF-2 function as transcriptional activators, HIF-3 inhibits HIF-1/2α action. Contrary to this idea, we show that zebrafish Hif-3α has strong transactivation activity. Hif-3α is degraded under normoxia. Mutation of P393, P493, and L503 inhibits this oxygen-dependent degradation. Transcriptomics and chromatin immunoprecipitation analyses identify genes that are regulated by Hif-3α, Hif-1α, or both. Under hypoxia or when overexpressed, Hif-3α binds to its target gene promoters and upregulates their expression. Dominant-negative inhibition and knockdown of Hif-3α abolish hypoxia-induced Hif-3α-promoter binding and gene expression. Hif-3α not only mediates hypoxia-induced growth and developmental retardation but also possesses hypoxia-independent activities. Importantly, transactivation activity is conserved and human HIF-3α upregulates similar genes in human cells. These findings suggest that Hif-3 is an oxygen-dependent transcription factor and activates a distinct transcriptional response to hypoxia.

  6. Understanding and exploiting the genomic response to hypoxia

    Giaccia, A.J.

    2003-01-01

    The tumor microenvironment influences both therapeutic outcome and malignant progression. Of the many factors that may be altered in the tumor microenvironment, changes in tumor oxygenation have been strongly associated with a lower probability of local tumor control and survival. In vitro studies indicate that cells exposed to a low oxygen environment exhibit multiple phenotypes, including cell-cycle arrest, increased expression of pro-angiogenic genes, increased invasive capacity, increased apoptosis, increased anaerobic metabolism and altered differentiation programs. While the mechanistic basis of hypoxia as an impediment to radiotherapy and chemotherapy is well understood, it is unclear what changes in the cellular phenotype are important in understanding how hypoxia modifies malignant progression. One insight into how hypoxia modulates malignant progression comes from understanding the critical transcriptional regulators of gene expression under hypoxic conditions such as hypoxia inducible factor 1 (HIF-1) as well as changes in gene expression in untransformed and transformed cells. Overall, about 1.5% of the genome is found to be transcriptionally responsive to changes in oxygenation. Most importantly, the coordinated changes in gene expression under hypoxic conditions underscore the physiologic basis for altering gene expression in response to a low oxygen environment. In addition, some hypoxia-induced genes exhibit increased expression after reoxygenation, suggesting that they are regulated both by hypoxia and oxidative stress. Analysis of the genomic response to hypoxia has several therapeutic uses. First, it allows one to ask the question of what the cellular consequences are to inhibition of the transcriptional response to hypoxia such as by targeting the HIF-1 transcription factor. While the effect of loss of HIF-1 in tumors leads to inhibition of tumor growth, it does not eliminate tumors. In fact, studies indicate that inhibition of HIF-1 leads to a

  7. Spironolactone inhibits production of proinflammatory cytokines, including tumour necrosis factor-alpha and interferon-gamma, and has potential in the treatment of arthritis

    Bendtzen, K; Hansen, P R; Rieneck, K

    2003-01-01

    and interleukin 6 (70-90% inhibition). Release of these cytokines was also suppressed when testing whole blood from RA patients receiving 50 mg spironolactone twice daily, indicating that pharmaceutical use of the drug may suppress the release of inflammatory cytokines. Spironolactone therapy was generally well...

  8. of brain tumours

    outline of the important clinical issues related to brain tumours and psychiatry. ... Left-sided, frontal tumours also seem to be associated with higher rates of depression, while those in the frontal lobe of the right .... Oxford: Blackwell Science,.

  9. Immunity to tumour antigens.

    Li, Geng; Ali, Selman A; McArdle, Stephanie E B; Mian, Shahid; Ahmad, Murrium; Miles, Amanda; Rees, Robert C

    2005-01-01

    During the last decade, a large number of human tumour antigens have been identified. These antigens are classified as tumour-specific shared antigens, tissue-specific differentiation antigens, overexpressed antigens, tumour antigens resulting from mutations, viral antigens and fusion proteins. Antigens recognised by effectors of immune system are potential targets for antigen-specific cancer immunotherapy. However, most tumour antigens are self-proteins and are generally of low immunogenicity and the immune response elicited towards these tumour antigens is not always effective. Strategies to induce and enhance the tumour antigen-specific response are needed. This review will summarise the approaches to discovery of tumour antigens, the current status of tumour antigens, and their potential application to cancer treatment.

  10. A prognostic profile of hypoxia-induced genes for localised high-grade soft tissue sarcoma

    Aggerholm-Pedersen, Ninna; Sørensen, Brita Singers; Overgaard, Jens

    2016-01-01

    sarcoma (STS). METHODS: The hypoxia-induced gene quantification was performed by real-time quantitative PCR (RT-qPCR) of formalin-fixed, paraffin-embedded tissue samples. The gene expression cut-points were determined in a test cohort of 55 STS patients and used to allocate each patient into a more......BACKGROUND: For decades, tumour hypoxia has been pursued as a cancer treatment target. However, prognostic and predictive biomarkers are essential for the use of this target in the clinic. This study investigates the prognostic value of a hypoxia-induced gene profile in localised soft tissue...

  11. The prognostic value of pimonidazole and tumour pO2 in human cervix carcinomas after radiation therapy: a prospective international multi-center study

    Nordsmark, Marianne; Loncaster, Julie; Aquino-Parsons, Christina

    2006-01-01

    BACKGROUND AND PURPOSE: Hypoxia adversely affects treatment outcome in human uterine cervical cancer. Here, we present the results of a prospective international multi-centre study evaluating the prognostic value of pre-treatment tumour oxygen partial pressure (pO(2)) and the hypoxia marker pimon...... pimonidazole (pimo). MATERIALS AND METHODS: One hundred and twenty-seven patients with primary cervix cancer were entered. Pre-treatment tumour pO(2) measurements were obtained, and reported by the median tumour pO(2), the fraction of pO(2) values......BACKGROUND AND PURPOSE: Hypoxia adversely affects treatment outcome in human uterine cervical cancer. Here, we present the results of a prospective international multi-centre study evaluating the prognostic value of pre-treatment tumour oxygen partial pressure (pO(2)) and the hypoxia marker...

  12. Comparison of the distribution of fluorine-18 fluoromisonidazole, deoxyglucose and methionine in tumour tissue

    Kubota, Kazuo; Tada, Masao; Yamada, Susumu; Hori, Katsuyoshi; Saito, Sachiko; Sato, Kazunori; Fukuda, Hiroshi; Iwata, Ren; Ido, Tatsuo

    1999-01-01

    To evaluate the tumour imaging potential of fluorine-18 fluoromisonidazole (FMISO), we studied FMISO uptake in an experimental tumour model and examined the correlation between intratumoral distributions of FMISO, 14 C-2-deoxyglucose (2DG) and 14 C-methionine (Met). The study was performed using control rats with the AH109A tumour and rats with the same tumour under local hypoxia. Tumour uptake of FMISO was constant between 30 min and 2 h after injection, and the tumour to muscle ratio was 2 from 2 to 4 h. A tumour study with FMISO was scheduled at 2 h. Double-tracer autoradiography of the tumour demonstrated that in the areas of high FMISO uptake, there was low uptake of Met, while areas of low FMISO uptake showed high Met uptake. FMISO showed high grain density in the rim of the tumour surrounding the necrotic area. 2DG showed a more uniform distribution over the entire section of viable cells. The mean uptake of FMISO by hypoxic, radioresistant tumours was significantly higher than that by the control tumours (P<0.05), while both 2DG and Met uptake by the control tumours was higher than uptake by hypoxic tumours. When individual tumours were examined, the uptake of FMISO was inversely correlated with that of Met (r = -0.507, P<0.02), while 2DG showed almost uniform uptake with no significant correlation to FMISO. In conclusion, hypoxic and radioresistant tumours could be identified by increased FMISO uptake in our model, consistent with findings reported by others. We found a large overlap in the distribution of FMISO and 2DG within the tumour, but only a small overlap in the distribution of FMISO and Met. A combination of FMISO and other tracers in positron emission tomography or single-photon emission tomography studies might be more helpful than single-tracer studies in predicting the response of tumour tissues to radiotherapy. (orig.)

  13. STX140, but not paclitaxel, inhibits mammary tumour initiation and progression in C3(1/SV40 T/t-antigen transgenic mice.

    Florence Meyer-Losic

    Full Text Available Despite paclitxael's clinical success, treating hormone-refractory breast cancer remains challenging. Paclitaxel has a poor pharmacological profile, characterized by a low therapeutic index (TIX caused by severe dose limiting toxicities, such as neutropenia and peripheral neuropathy. Consequently, new drugs are urgently required. STX140, a compound previously shown to have excellent efficacy against many tumors, is here compared to paclitaxel in three translational in vivo breast cancer models, a rat model of peripheral neuropathy, and through pharmacological testing. Three different in vivo mouse models of breast cancer were used; the metastatic 4T1 orthotopic model, the C3(1/SV40 T-Ag model, and the MDA-MB-231 xenograft model. To determine TIX and pharmacological profile of STX140, a comprehensive dosing regime was performed in mice bearing MDA-MD-231 xenografts. Finally, peripheral neuropathy was examined using a rat plantar thermal hyperalgesia model. In the 4T1 metastatic model, STX140 and paclitaxel significantly inhibited primary tumor growth and lung metastases. All C3(1/SV40 T-Ag mice in the control and paclitaxel treated groups developed palpable mammary cancer. STX140 blocked 47% of tumors developing and significantly inhibited growth of tumors that did develop. STX140 treatment caused a significant (P<0.001 survival advantage for animals in early and late intervention groups. Conversely, in C3(1/SV40 T-Ag mice, paclitaxel failed to inhibit tumor growth and did not increase survival time. Furthermore, paclitaxel, but not STX140, induced significant peripheral neuropathy and neutropenia. These results show that STX140 has a greater anti-cancer efficacy, TIX, and reduced neurotoxicity compared to paclitaxel in C3(1/SV40 T-Ag mice and therefore may be of significant benefit to patients with breast cancer.

  14. Interstitial fluid pressure, vascularity and metastasis in ectopic, orthotopic and spontaneous tumours

    Lunt, Sarah Jane; Kalliomaki, Tuula MK; Brown, Allison; Yang, Victor X; Milosevic, Michael; Hill, Richard P

    2008-01-01

    High tumour interstitial fluid pressure (IFP) has been adversely linked to poor drug uptake in patients, and to treatment response following radiotherapy in cervix cancer patients. In this study we measured IFP values in a selection of murine and xenograft models, spontaneously arising or transplanted either intramuscularly (i/m) or orthotopically and analysed their relationship to tumour vascularity and metastatic spread. KHT-C murine fibrosarcoma, ME180 and SiHa human cervix carcinoma were grown either intramuscularly (i/m), sub-cutaneously (s/c) or orthotopically. Polyoma middle-T (MMTV-PyMT) transgenic spontaneous mammary tumours were studied either as spontaneous tumours or following orthotopic or i/m transplantation. IFP was measured in all tumours using the wick-in-needle method. Spontaneous metastasis formation in the lungs or lymph nodes was assessed in all models. An immunohistochemical analysis of tumour hypoxia, vascular density, lymphatic vascular density and proliferation was carried out in ME180 tumours grown both i/m and orthotopically. Blood flow was also assessed in the ME180 model using high-frequency micro-ultrasound functional imaging. Tumour IFP was heterogeneous in all the models irrespective of growth site: KHT-C i/m: 2–42 mmHg, s/c: 1–14 mmHg, ME180: i/m 5–68 mmHg, cervix 4–21 mmHg, SiHa: i/m 20–56 mmHg, cervix 2–26 mmHg, MMTV-PyMT: i/m: 13–45 mmHg, spontaneous 2–20 mmHg and transplanted 2–22 mmHg. Additionally, there was significant variation between individual tumours growing in the same mouse, and there was no correlation between donor and recipient tumour IFP values. Metastatic dissemination to the lungs or lymph nodes demonstrated no correlation with tumour IFP. Tumour hypoxia, proliferation, and lymphatic or blood vessel density also showed no relationship with tumour IFP. Speckle variance analysis of ultrasound images showed no differences in vascular perfusion between ME180 tumours grown i/m versus orthotopically

  15. The impact of hypoxia on oncolytic virotherapy

    Guo ZS

    2011-11-01

    Full Text Available Z Sheng GuoUniversity of Pittsburgh Cancer Institute and Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USAAbstract: The hypoxic tumor microenvironment plays significant roles in tumor cell metabolism and survival, tumor growth, and progression. Hypoxia modulates target genes in target cells mainly through an oxygen-sensing signaling pathway mediated by hypoxia-inducible factor of transcription factors. As a result, hypoxic tumor cells are resistant to conventional therapeutics such as radiation and chemotherapy. Oncolytic virotherapy may be a promising novel therapeutic for hypoxic cancer. Some oncolytic viruses are better adapted than others to the hypoxic tumor environment. Replication of adenoviruses from both groups B and C is inhibited, yet replication of herpes simplex virus is enhanced. Hypoxia seems to exert little or no effect on the replication of other oncolytic viruses. Vaccinia virus displayed increased cytotoxicity in some hypoxic cancer cells even though viral protein synthesis and transgene expression were not affected. Vesicular stomatitis virus replicated to similar levels in both hypoxic and normoxic conditions, and is effective for killing hypoxic cancer cells. However, vesicular stomatitis virus and reovirus, but not encephalomyocarditis virus, are sensitive to elevated levels of hypoxia-inducible factor-1α in renal cancer cells with the loss of von Hippel–Lindau tumor suppressor protein, because elevated hypoxia-inducible factor activity confers dramatically enhanced resistance to cytotoxicity mediated by vesicular stomatitis virus or reovirus. A variety of hypoxia-selective and tumor-type-specific oncolytic adenoviruses, generated by incorporating hypoxia-responsive elements into synthetic promoters to control essential genes for viral replication or therapeutic genes, have been shown to be safe and efficacious. Hypoxic tumor-homing macrophages can function effectively as carrier

  16. The prognostic value of temporal in vitro and in vivo derived hypoxia gene-expression signatures in breast cancer

    Starmans, Maud H.W.; Chu, Kenneth C.; Haider, Syed; Nguyen, Francis; Seigneuric, Renaud; Magagnin, Michael G.; Koritzinsky, Marianne; Kasprzyk, Arek; Boutros, Paul C.; Wouters, Bradly G.

    2012-01-01

    Background and purpose: Recent data suggest that in vitro and in vivo derived hypoxia gene-expression signatures have prognostic power in breast and possibly other cancers. However, both tumour hypoxia and the biological adaptation to this stress are highly dynamic. Assessment of time-dependent gene-expression changes in response to hypoxia may thus provide additional biological insights and assist in predicting the impact of hypoxia on patient prognosis. Materials and methods: Transcriptome profiling was performed for three cell lines derived from diverse tumour-types after hypoxic exposure at eight time-points, which include a normoxic time-point. Time-dependent sets of co-regulated genes were identified from these data. Subsequently, gene ontology (GO) and pathway analyses were performed. The prognostic power of these novel signatures was assessed in parallel with previous in vitro and in vivo derived hypoxia signatures in a large breast cancer microarray meta-dataset (n = 2312). Results: We identified seven recurrent temporal and two general hypoxia signatures. GO and pathway analyses revealed regulation of both common and unique underlying biological processes within these signatures. None of the new or previously published in vitro signatures consisting of hypoxia-induced genes were prognostic in the large breast cancer dataset. In contrast, signatures of repressed genes, as well as the in vivo derived signatures of hypoxia-induced genes showed clear prognostic power. Conclusions: Only a subset of hypoxia-induced genes in vitro demonstrates prognostic value when evaluated in a large clinical dataset. Despite clear evidence of temporal patterns of gene-expression in vitro, the subset of prognostic hypoxia regulated genes cannot be identified based on temporal pattern alone. In vivo derived signatures appear to identify the prognostic hypoxia induced genes. The prognostic value of hypoxia-repressed genes is likely a surrogate for the known importance of

  17. Tumour-associated microglia/macrophages predict poor prognosis in high-grade gliomas and correlate with an aggressive tumour subtype

    Sørensen, M D; Dahlrot, R H; Boldt, H B

    2018-01-01

    (+) TAMs co-expressed proteins related to tumour aggressiveness including matrix metallopeptidase-14 and hypoxia-inducible factor-1α. CONCLUSIONS: This is the first study to use automated quantitative immunofluorescence to determine the prognostic impact of TAMs. Our results suggest that M2-like TAMs hold......AIMS: Glioblastomas are highly aggressive and treatment resistant. Increasing evidence suggests that tumour-associated macrophages/microglia (TAMs) facilitate tumour progression by acquiring a M2-like phenotype. Our objective was to investigate the prognostic value of TAMs in gliomas using...

  18. Relationship between radiobiological hypoxia in a C3H mouse mammary carcinoma and osteopontin levels in mouse serum

    Lukácová, Slávka; Khalil, Azza Ahmed; Overgaard, Jens

    2005-01-01

    To investigate the possible relationship between radiobiological hypoxia in a C3H mouse mammary carcinoma and osteopontin (OPN) levels measured in mouse serum. MATERIAL AND METHODS: Experiments were performed in CDF1 mice that were either non-tumour bearing or with different sized tumours implanted...... in the right rear foot. Osteopontin levels in extracted mouse blood serum and tissue from the transplanted tumours were measured using an ELISA assay. The tumour oxygenation status was estimated using the Eppendorf Histograph and the fraction of oxygen partial pressure (pO2) values =5 mm Hg (HF5...

  19. Mesenchymal Stem Cells Respond to Hypoxia by Increasing Diacylglycerols.

    Lakatos, Kinga; Kalomoiris, Stefanos; Merkely, Béla; Nolta, Jan A; Fierro, Fernando A

    2016-02-01

    Mesenchymal stem cells (MSC) are currently being tested clinically for a plethora of conditions, with most approaches relying on the secretion of paracrine signals by MSC to modulate the immune system, promote wound healing, and induce angiogenesis. Hypoxia has been shown to affect MSC proliferation, differentiation, survival and secretory profile. Here, we investigate changes in the lipid composition of human bone marrow-derived MSC after exposure to hypoxia. Using mass spectrometry, we compared the lipid profiles of MSC derived from five different donors, cultured for two days in either normoxia (control) or hypoxia (1% oxygen). Hypoxia induced a significant increase of total triglycerides, fatty acids and diacylglycerols (DG). Remarkably, reduction of DG levels using the phosphatidylcholine-specific phospholipase C inhibitor D609 inhibited the secretion of VEGF and Angiopoietin-2, but increased the secretion of interleukin-8, without affecting significantly their respective mRNA levels. Functionally, incubation of MSC in hypoxia with D609 inhibited the potential of the cells to promote migration of human endothelial cells in a wound/scratch assay. Hence, we show that hypoxia induces in MSC an increase of DG that may affect the angiogenic potential of these cells. © 2015 Wiley Periodicals, Inc.

  20. Radioiodinated 2-nitrobenzyl carbamates as bioreductive alkylating agents for tissue hypoxia

    Culbert, P.A.; Hunter, D.H.; Wearring, A.V.; Chamberlain, M.J.

    1993-01-01

    Three N-methylcarbamates of iodonitrobenzyl alcohols (4-iodo-2-nitrobenzyl alcohol 2, 5-iodo-2-nitrobenzyl alcohol 3 and 4-iodo-2,6-dinitrobenzyl alcohol 4) bearing [ 125 I] have been prepared and characterized for their lipophilicity, their reduction potentials and the in vivo lability of the radioiodine in healthy mice. Based upon these results, 2 and 4 were tested in tumour-bearing mice showing limited uptake of radioactivity in tumours and a tumour-to-blood ratio of less than 1. Consequently these particular carbamates are not satisfactory as hypoxia imaging agents. (Author)

  1. Imaging of sacral tumours

    Gerber, S.; Ollivier, L.; Brisse, H.; Neuenschwander, S.; Leclere, J.; Vanel, D.; Missenard, G.; Pinieux, G. de

    2008-01-01

    All components of the sacrum (bone, cartilage, bone marrow, meninges, nerves, notochord remnants, etc.) can give rise to benign or malignant tumours. Bone metastases and intraosseous sites of haematological malignancies, lymphoma and multiple myeloma are the most frequent aetiologies, while primary bone tumours and meningeal or nerve tumours are less common. Some histological types have a predilection for the sacrum, especially chordoma and giant cell tumour. Clinical signs are usually minor, and sacral tumours are often discovered in the context of nerve root or pelvic organ compression. The roles of conventional radiology, CT and MRI are described and compared with the histological features of the main tumours. The impact of imaging on treatment decisions and follow-up is also reviewed. (orig.)

  2. Imaging of sacral tumours

    Gerber, S.; Ollivier, L.; Brisse, H.; Neuenschwander, S. [Institut Curie, Department of Radiology, Paris (France); Leclere, J. [Institut Gustave Roussy, Department of Radiology, Villejuif (France); Vanel, D. [The Rizzoli Institute, Department of Radiology, Bologna (Italy); Missenard, G. [Institut Gustave Roussy, Comite de pathologie tumorale de l' appareil locomoteur, Villejuif (France); Pinieux, G. de [CHRU de Tours, Department of Pathology, Hopital Trousseau, Tours (France)

    2008-04-15

    All components of the sacrum (bone, cartilage, bone marrow, meninges, nerves, notochord remnants, etc.) can give rise to benign or malignant tumours. Bone metastases and intraosseous sites of haematological malignancies, lymphoma and multiple myeloma are the most frequent aetiologies, while primary bone tumours and meningeal or nerve tumours are less common. Some histological types have a predilection for the sacrum, especially chordoma and giant cell tumour. Clinical signs are usually minor, and sacral tumours are often discovered in the context of nerve root or pelvic organ compression. The roles of conventional radiology, CT and MRI are described and compared with the histological features of the main tumours. The impact of imaging on treatment decisions and follow-up is also reviewed. (orig.)

  3. Nuclear medicine in childhood tumours

    Hoefnagel, C.A.

    2004-01-01

    Full text: In recent years the contribution of nuclear medicine has been of increasing interest to paediatric oncology, in particular in imaging for diagnosis, staging and follow-up, in quantitative function analysis of organs at risk during oncological therapy, as well as in radionuclide therapy. For tumour imaging a great number of tumour-seeking radiopharmaceuticals are available, exploiting various metabolic and biological properties of individual tumours; several of these agents can also be applied for radionuclide therapy. More recent tracers allow the characterization of tumours, highlighting features like hormone receptors, hypoxia, MDR and apoptosis. New techniques in paediatric oncology include PET and probe-guided surgery. As a functional modality, nuclear medicine is well suited to monitor the function of organs at risk during treatment in paediatric oncology, in particular cardiac, pulmonary, renal and salivary gland function. A summary of applications and major Indications will be presented. Osteosarcoma: In differentiated osteosarcoma bone scintigraphy/SPECT using 99m Tc-diphosphonate may, as a result of Its targeting the tumour-produced osteoid, visualize not only the primary bone tumour and skeletal metastases, but also the extraosseous metastases. For preoperative therapy nd palliation of metastases beta-emitting bone-seeking agents, such as 89 Sr-chloride, 186 Re-HEDP and 153 Sm-EDTMP, are available. Lymphoma: 67 Ga-citrate has been used for decades in the detection, staging and follow up of lymphoma, as well as for early recognition of response to therapy. 201 TI-chloride scintigraphy/SPECT and PET using 18 F-deoxyglucose can also be used for this purpose. 99m Tc- sestamibi and 99m Tc-tetrofosmin are associated with p-glycoprotein, playing a role in multidrug resistance. In adults with recurrent non Hodgkin lymphoma treatment with 131 l- or 90 Y labelled anti-CD20 antibodies is highly effective. Thyroid carcinoma. 201 TI-chloride scintigraphy

  4. Elevation of hypoxia resistance with the use of gutimine

    Vinogradov, V.M.; Pastushenkov, L.V.; Sumina, E.N.

    Experimental data demonstrating the protection from the adverse effects of hypoxia offered by the antioxidant gutimine and its analogs are presented. The experiments included preliminary studies of hypoxia resistance and recovery under simulated altitude, studies of circulatory hypoxia in the brain and in intrauterine fetuses, studies of myocardial ischemia during acute and chronic experiments and studies where cardiac, kidney and limb circulation is cut off. The compound was also found to be effective in cases of hemorrhagic hypotension, complex hypoxia in peritonitis, meningococcal meningitis, and the weakening of uterine muscle contractility during prolonged deliveries, and in cranial-cerebral trauma. Mechanisms of the antihypoxic action of gutimine and its analogs have been found to include the reduction of oxygen utilization, the activation of aerobic and anaerobic metabolism, the acceleration of lactate utilization, the inhibition of lipolysis in fat tissue, and stabilization of cell membranes. Clinical observations also support the experimental data.

  5. The radiation response of cells recovering after chronic hypoxia

    Kwok, T.T.; Sutherland, R.M.

    1989-01-01

    Experiments were performed to study the influence of hypoxic pretreatment on the radiation response of A431 human squamous carcinoma cells. Reaeration for 10 min after chronic hypoxia (greater than 2 h) was found to enhance the radiosensitivity of A431 cells, and the maximal effect was seen for those cells reaerated after 12 h of hypoxia. The radiosensitivity enhancement for reaerated cells after 12 h of hypoxia was maximized by 5 min after the return to aerobic conditions and reached the control level by 12 h of reaeration. This enhanced radiosensitive state was characterized by a reduced shoulder region and increased slope of the radiation dose-response curve for cells in both the exponential and plateau phases of growth. There was a slight increase in the number of G1 and decrease in the number of S and G2 + M cells for both exponential- and plateau-phase cultures following 12 h hypoxic treatment. Although growth inhibition induced by 12 h of hypoxia was seen for cells in the exponential phase, there was no cell number change in the plateau-phase culture after hypoxia. Plating efficiency (PE) of cells in both growth phases was reduced by 30% after hypoxia. Furthermore, in the exponential-phase culture, the extent of reduction in PE after hypoxia was similar among cells in different phases of the cell cycle. Although S-phase cells in exponentially growing cultures were relatively more resistant to radiation than G1 and G2 + M cells, the cell age-response pattern was the same whether the cells had been aerobic or hypoxic before reaeration and irradiation. Furthermore, the enhancement ratio associated with reaeration after 12 h of hypoxia for these three subpopulations of cells was 1.3. Our results indicate that the increase in radiosensitivity due to reaeration after chronic hypoxia is unlikely to be related to the changes of cell cycle stage and growth phase during hypoxic treatment

  6. Delivery of chemotherapeutic drugs in tumour cell-derived microparticles.

    Tang, Ke; Zhang, Yi; Zhang, Huafeng; Xu, Pingwei; Liu, Jing; Ma, Jingwei; Lv, Meng; Li, Dapeng; Katirai, Foad; Shen, Guan-Xin; Zhang, Guimei; Feng, Zuo-Hua; Ye, Duyun; Huang, Bo

    2012-01-01

    Cellular microparticles are vesicular plasma membrane fragments with a diameter of 100-1,000 nanometres that are shed by cells in response to various physiological and artificial stimuli. Here we demonstrate that tumour cell-derived microparticles can be used as vectors to deliver chemotherapeutic drugs. We show that tumour cells incubated with chemotherapeutic drugs package these drugs into microparticles, which can be collected and used to effectively kill tumour cells in murine tumour models without typical side effects. We describe several mechanisms involved in this process, including uptake of drug-containing microparticles by tumour cells, synthesis of additional drug-packaging microparticles by these cells that contribute to the cytotoxic effect and the inhibition of drug efflux from tumour cells. This study highlights a novel drug delivery strategy with potential clinical application.

  7. Vasculogenic Mimicry of HT1080 Tumour Cells In Vivo: Critical Role of HIF-1α-Neuropilin-1 Axis

    Misra, Roli M.; Bajaj, Manmohan S.; Kale, Vaijayanti P.

    2012-01-01

    HT1080 - a human fibrosarcoma-derived cell line – forms aggressive angiogenic tumours in immuno-compromised mice. In spite of its extensive use as a model of tumour angiogenesis, the molecular event(s) initiating the angiogenic program in these cells are not known. Since hypoxia stimulates tumour angiogenesis, we examined the hypoxia-induced events evoked in these cells. In contrast to cells grown under normoxic conditions, hypoxia-primed (1% O2) HT1080 cells formed robust tubules on growth factor-reduced matrigel and formed significantly larger tumours in xenograft models in a chetomin-sensitive manner, indicating the role of HIF-1α-mediated transcription in these processes. Immuno-histochemical analyses of tumours formed by GFP-expressing HT1080 cells clearly showed that the tumour cells themselves expressed various angiogenic markers including Neuropilin-1 (NRP-1) and formed functional vessels containing red blood cells, thereby unambiguously demonstrating the vasculogenic mimicry of HT1080 cells in vivo. Experiments performed with the HT1080 cells stably transfected with plasmid constructs expressing shNRP-1 or full-length NRP-1 clearly established that the HIF1α-mediated up-regulation of NRP-1 played a deterministic role in the process. Hypoxia-exposure resulted in an up-regulation of c-Myc and OCT3/4 and a down-regulation of KLF4 mRNAs, suggesting their involvement in the tumour formation and angiogenesis. However, silencing of NRP-1 alone, though not affecting proliferation in culture, was sufficient to abrogate the tumour formation completely; clearly establishing that the hypoxia-mediated HIF-1α-dependent up-regulation of NRP-1 is a critical molecular event involved in the vasculogenic mimicry and tumor formation by HT1080 cells in vivo. PMID:23185562

  8. Tirapazamine causes vascular dysfunction in HCT-116 tumour xenografts

    Huxham, Lynsey A.; Kyle, Alastair H.; Baker, Jennifer H.E.; McNicol, Krista L.; Minchinton, Andrew I.

    2006-01-01

    Background and purpose: Tirapazamine is a hypoxic cytotoxin currently undergoing Phase II/III clinical evaluation in combination with radiation and chemotherapeutics for the treatment of non-hematological cancers. Tissue penetration studies using multicellular models have suggested that tirapazamine exposure may be limited to cells close to blood vessels. However, animal studies show tirapazamine enhances the anti-tumour activity of radiation and chemotherapy and clinical studies with tirapazamine, so far, are promising. To investigate this apparent paradox we examined the microregional effects of tirapazamine in vivo by mapping drug effects with respect to the position of blood vessels in tumour cryosections. Patients and methods: Tirapazamine was administered i.p. to mice bearing HCT-116 tumours, which were excised at various times after treatment. Images of multiple-stained cryosections were overlaid to provide microregional information on the relative position of proliferating cells, hypoxia, perfusion and vasculature. Results: We observed extensive and permanent vascular dysfunction in a large proportion of tumours from mice treated with tirapazamine. In the affected tumours, blood flow ceased in the centrally located tumour vessels, leaving a rim of functional vessels around the periphery of the tumour. This vascular dysfunction commenced within 24 h after tirapazamine administration and the areas affected appeared to be replaced by necrosis over the following 24-48 h. Conclusions: Because the majority of hypoxic cells are located in the center of tumours we propose that the activity of tirapazamine in vivo may be related to its effects on tumour vasculature and that its activity against hypoxic cells located distal to functional blood vessels may not be as important as previously believed

  9. Wilms' tumour (nephroblastoma)

    Wilms' tumour or nephroblastoma is a cancer of the kidney that ... It may be noticed by parents or it may be an incidental finding ... patients. It may lead to iron deficiency anaemia. Rarely Wilms' tumour may present with acquired von Willebrand's ... the best treatment approach. ... with multimodality therapy in paediatric.

  10. Hypoxia downregulates Ku70/80 expression in cervical carcinoma tumors

    Lara, Pedro Carlos; Lloret, Marta; Clavo, Bernardino; Apolinario, Rosa Maria; Bordon, Elisa; Rey, Agustin; Falcon, Orlando; Alonso, Ana Ruiz; Belka, Claus

    2008-01-01

    Hypoxia may inhibits the NHEJ DNA repair through downregulating Ku70/80 expression and combined with an increased angiogenesis and altered p53 expression would be responsible for tumor progression in cervical carcinoma

  11. Hypoxia-inducible factor signalling mechanisms in the central nervous system.

    Corcoran, A; O'Connor, J J

    2013-08-01

    In the CNS, neurones are highly sensitive to the availability of oxygen. In conditions where oxygen availability is decreased, neuronal function can be altered, leading to injury and cell death. Hypoxia has been implicated in a number of central nervous system pathologies including stroke, head trauma and neurodegenerative diseases. Cellular responses to oxygen deprivation are complex and result in activation of short- and long-term mechanisms to conserve energy and protect cells. Failure of synaptic transmission can be observed within minutes following this hypoxia. The acute effects of hypoxia on synaptic transmission are primarily mediated by altering ion fluxes across membranes, pre-synaptic effects of adenosine and other actions at glutamatergic receptors. A more long-term feature of the response of neurones to hypoxia is the activation of transcription factors such as hypoxia-inducible factor. The activation of hypoxia-inducible factor is governed by a family of dioxygenases called hypoxia-inducible factor prolyl 4 hydroxylases (PHDs). Under hypoxic conditions, PHD activity is inhibited, thereby allowing hypoxia-inducible factor to accumulate and translocate to the nucleus, where it binds to the hypoxia-responsive element sequences of target gene promoters. Inhibition of PHD activity stabilizes hypoxia-inducible factor and other proteins thus acting as a neuroprotective agent. This review will focus on the response of neuronal cells to hypoxia-inducible factor and its targets, including the prolyl hydroxylases. We also present evidence for acute effects of PHD inhibition on synaptic transmission and plasticity in the hippocampus. © 2013 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  12. Electrochemotherapy of tumours

    Sersa, G.; Cemazar, M.; Rudolf, Z.; Miklavcic, D.

    2006-01-01

    Electrochemotherapy consists of chemotherapy followed by local application of electric pulses to the tumour to increase drug delivery into cells. Drug uptake can be increased by electroporation for only those drugs whose transport through the plasma membrane is impeded. Among many drugs that have been tested so far, only bleomycin and cisplatin found their way from preclinical testing to clinical trials. In vitro studies demonstrated several fold increase of their cytotoxicity after electroporation of cells. In vivo, electroporation of tumours after local or systemic administration of either of the drugs, i.e. electrochemotherapy, proved to be an effective antitumour treatment. In preclinical studies on several tumour models, electrochemotherapy either with bleomycin or cisplatin was elaborated and parameters for effective local tumour control were determined. In veterinary medicine, electrochemotherapy also proved to be effective in the treatment of primary tumours in cats, dogs and horses. In human clinical studies, electrochemotherapy was performed on the patients with progressive disease and accessible tumour nodules of different malignancies. All clinical studies demonstrated that electrochemotherapy is an effective treatment for local tumour control in cancer patients. (author)

  13. Tumour-induced osteomalacia.

    Minisola, Salvatore; Peacock, Munro; Fukumoto, Seijii; Cipriani, Cristiana; Pepe, Jessica; Tella, Sri Harsha; Collins, Michael T

    2017-07-13

    Tumour-induced osteomalacia (TIO), also known as oncogenic osteomalacia, is a rare paraneoplastic disorder caused by tumours that secrete fibroblast growth factor 23 (FGF23). Owing to the role of FGF23 in renal phosphate handling and vitamin D synthesis, TIO is characterized by decreased renal tubular reabsorption of phosphate, by hypophosphataemia and by low levels of active vitamin D. Chronic hypophosphataemia ultimately results in osteomalacia (that is, inadequate bone mineralization). The diagnosis of TIO is usually suspected when serum phosphate levels are chronically low in the setting of bone pain, fragility fractures and muscle weakness. Locating the offending tumour can be very difficult, as the tumour is often very small and can be anywhere in the body. Surgical removal of the tumour is the only definitive treatment. When the tumour cannot be located or when complete resection is not possible, medical treatment with phosphate salts or active vitamin D is necessary. One of the most promising emerging treatments for unresectable tumours that cause TIO is the anti-FGF23 monoclonal antibody KRN23. The recent identification of a fusion of fibronectin and fibroblast growth factor receptor 1 (FGFR1) as a molecular driver in some tumours not only sheds light on the pathophysiology of TIO but also opens the door to a better understanding of the transcription, translocation, post-translational modification and secretion of FGF23, as well as suggesting approaches to targeted therapy. Further study will reveal if the FGFR1 pathway is also involved in tumours that do not harbour the translocation.

  14. Malignant thyroid tumours

    Boerner, W.; Reiners, C.

    1987-01-01

    The subjects dealt with at the symposium cover all topical aspects of pathology, epidemiology, diagnosis, therapy, and aftercare of the malignant thyroid tumours. A survey of the histological classification of the thyroid tumours and a review of the latest findings concerning the radiocarcinogenesis are followed by a detailed discussion of the most significant tumours. There are also papers dealing with controversial aspects of the histological classification, the value of diagnostic methods, radicality of the therapy, or after care. For five conference papers, separate records are available in the database. (orig./ECB) With 59 figs.; 57 tabs [de

  15. Acetyltransferases and tumour suppression

    Phillips, A C; Vousden, Karen H

    2000-01-01

    The acetyltransferase p300 was first identified associated with the adenoviral transforming protein E1A, suggesting a potential role for p300 in the regulation of cell proliferation. Direct evidence demonstrating a role for p300 in human tumours was lacking until the recentl publication by Gayther et al, which strongly supports a role for p300 as a tumour suppressor. The authors identify truncating mutations associated with the loss or mutation of the second allele in both tumour samples and cell lines, suggesting that loss of p300 may play a role in the development of a subset of human cancers

  16. Hypoxia upregulates neutrophil degranulation and potential for tissue injury

    Hoenderdos, Kim; Lodge, Katharine M; Hirst, Robert A; Chen, Cheng; Palazzo, Stefano G C; Emerenciana, Annette; Summers, Charlotte; Angyal, Adri; Porter, Linsey; Juss, Jatinder K; O'Callaghan, Christopher; Chilvers, Edwin R

    2016-01-01

    Background The inflamed bronchial mucosal surface is a profoundly hypoxic environment. Neutrophilic airway inflammation and neutrophil-derived proteases have been linked to disease progression in conditions such as COPD and cystic fibrosis, but the effects of hypoxia on potentially harmful neutrophil functional responses such as degranulation are unknown. Methods and results Following exposure to hypoxia (0.8% oxygen, 3 kPa for 4 h), neutrophils stimulated with inflammatory agonists (granulocyte-macrophage colony stimulating factor or platelet-activating factor and formylated peptide) displayed a markedly augmented (twofold to sixfold) release of azurophilic (neutrophil elastase, myeloperoxidase), specific (lactoferrin) and gelatinase (matrix metalloproteinase-9) granule contents. Neutrophil supernatants derived under hypoxic but not normoxic conditions induced extensive airway epithelial cell detachment and death, which was prevented by coincubation with the antiprotease α-1 antitrypsin; both normoxic and hypoxic supernatants impaired ciliary function. Surprisingly, the hypoxic upregulation of neutrophil degranulation was not dependent on hypoxia-inducible factor (HIF), nor was it fully reversed by inhibition of phospholipase C signalling. Hypoxia augmented the resting and cytokine-stimulated phosphorylation of AKT, and inhibition of phosphoinositide 3-kinase (PI3K)γ (but not other PI3K isoforms) prevented the hypoxic upregulation of neutrophil elastase release. Conclusion Hypoxia augments neutrophil degranulation and confers enhanced potential for damage to respiratory airway epithelial cells in a HIF-independent but PI3Kγ-dependent fashion. PMID:27581620

  17. No evidence for promoter region methylation of the succinate dehydrogenase and fumarate hydratase tumour suppressor genes in breast cancer

    Dobrovic Alexander

    2009-09-01

    Full Text Available Abstract Background Succinate dehydrogenase (SDH and fumarate hydratase (FH are tricarboxylic acid (TCA cycle enzymes that are also known to act as tumour suppressor genes. Increased succinate or fumarate levels as a consequence of SDH and FH deficiency inhibit hypoxia inducible factor-1α (HIF-1α prolyl hydroxylases leading to sustained HIF-1α expression in tumours. Since HIF-1α is frequently expressed in breast carcinomas, DNA methylation at the promoter regions of the SDHA, SDHB, SDHC and SDHD and FH genes was evaluated as a possible mechanism in silencing of SDH and FH expression in breast carcinomas. Findings No DNA methylation was identified in the promoter regions of the SDHA, SDHB, SDHC, SDHD and FH genes in 72 breast carcinomas and 10 breast cancer cell lines using methylation-sensitive high resolution melting which detects both homogeneous and heterogeneous methylation. Conclusion These results show that inactivation via DNA methylation of the promoter CpG islands of SDH and FH is unlikely to play a major role in sporadic breast carcinomas.

  18. Anti-tumour immune effect of oral administration of Lactobacillus plantarum to CT26 tumour-bearing mice.

    Hu, Jingtao; Wang, Chunfeng; Ye, Liping; Yang, Wentao; Huang, Haibin; Meng, Fei; Shi, Shaohua; Ding, Zhuang

    2015-06-01

    Colorectal cancer (CRC) is one of the most prevalent forms of cancer that shows a high mortality and increasing incidence. There are numerous successful treatment options for CRC, including surgery, chemotherapy, radiotherapy and immunotherapy; however, their side effects and limitations are considerable. Probiotics may be an effective strategy for preventing and inhibiting tumour growth through stimulation of host innate and adaptive immunity. We investigated and compared potential anti-tumour immune responses induced by two isolated Lactobacillus strains, Lactobacillus plantarum A and Lactobacillus rhamnosus b, by pre-inoculating mice with lactobacilli for 14 days. Subsequently, subcutaneous and orthotopic intestinal tumours were generated in the pre-inoculated mice using CT26 murine adenocarcinoma cells and were assessed for response against the tumour. Our results indicated that oral administration with L. plantarum inhibited CT26 cell growth in BALB/c mice and prolonged the survival time of tumour-bearing mice compared with mice administered L. rhamnosus. L. plantarum produced protective immunity against the challenge with CT26 cells by increasing the effector functions of CD8+ and natural killer (NK) cell infiltration into tumour tissue, up-regulation of IFN-gamma (but not IL-4 or IL-17) production, and promotion of Th1-type CD4+ T differentiation. Consequently, our results suggest that L. plantarum can enhance the anti-tumour immune response and delay tumour formation.

  19. Targeting radiation to tumours

    Wheldon, T.E.; Greater Glasgow Health Board, Glasgow

    1994-01-01

    Biologically targeted radiotherapy entails the preferential delivery of radiation to solid tumours or individual tumour cells by means of tumour-seeking delivery vehicles to which radionuclides can be conjugated. Monoclonal antibodies have attracted attention for some years as potentially selective targeting agents, but advances in tumour and molecular biology are now providing a much wider choice of molecular species. General radiobiological principles may be derived which are applicable to most forms of targeted radiotherapy. These principles provide guidelines for the appropriate choice of radionuclide in specific treatment situations and its optimal combination with other treatment modalities. In future, the availability of gene targeting agents will focus attention on the use of Auger electron emitters whose high potency and short range selectivity makes them attractive choices for specific killing of cancer cells whose genetic peculiarities are known. (author)

  20. [Gastric mesenchymal tumours (GIST)].

    Spivach, Arrigo; Fezzi, Margherita; Sartori, Alberto; Belgrano, Manuel; Rimondini, Alessandra; Cuttin-Zernich, Roberto; Covab, Maria Assunta; Bonifacio, Daniela; Buri, Luigi; Pagani, Carlo; Zanconati, Fabrizio

    2008-01-01

    The incidence of gastrointestinal stromal tumours (GIST) has increased in recent years. A number of authors have attempted to define the actual nature of these tumours. Immunohistochemistry highlighting the positivity of tyrosine-kinase (CD117/c-Kit) has revealed the difference between gastrointestinal stromal tumours and other mesenchymal tumours and, therefore, the possibility of medical rather than surgical therapy. We retrospectively reviewed 19 patients affected by primary gastric GIST, who underwent surgery in recent years with subsequent follow-up. Gastroscopy and gastrointestinal tract radiography were used not only to obtain the diagnosis but also to establish the size, density, contours, ulceration, regional lymphadenopathy, mesenteric infiltration and the presence of metastases. The aim of this study was to evaluate the roles of endoscopy and radiology in this pathology and the advantages and limitations of each individual technique.

  1. Hypoxia activates muscle-restricted coiled-coil protein (MURC) expression via transforming growth factor-β in cardiac myocytes.

    Shyu, Kou-Gi; Cheng, Wen-Pin; Wang, Bao-Wei; Chang, Hang

    2014-03-01

    The expression of MURC (muscle-restricted coiled-coil protein), a hypertrophy-regulated gene, increases during pressure overload. Hypoxia can cause myocardial hypertrophy; however, how hypoxia affects the regulation of MURC in cardiomyocytes undergoing hypertrophy is still unknown. The aim of the present study was to test the hypothesis that hypoxia induces MURC expression in cardiomyocytes during hypertrophy. The expression of MURC was evaluated in cultured rat neonatal cardiomyocytes subjected to hypoxia and in an in vivo model of AMI (acute myocardial infarction) to induce myocardial hypoxia in adult rats. MURC protein and mRNA expression were significantly enhanced by hypoxia. MURC proteins induced by hypoxia were significantly blocked after the addition of PD98059 or ERK (extracellular-signal-regulated kinase) siRNA 30 min before hypoxia. Gel-shift assay showed increased DNA-binding activity of SRF (serum response factor) after hypoxia. PD98059, ERK siRNA and an anti-TGF-β (transforming growth factor-β) antibody abolished the SRF-binding activity enhanced by hypoxia or exogenous administration of TGF-β. A luciferase promoter assay demonstrated increased transcriptional activity of SRF in cardiomyocytes by hypoxia. Increased βMHC (β-myosin heavy chain) and BNP (B-type natriuretic peptide) protein expression and increased protein synthesis was identified after hypoxia with the presence of MURC in hypertrophic cardiomyocytes. MURC siRNA inhibited the hypertrophic marker protein expression and protein synthesis induced by hypoxia. AMI in adult rats also demonstrated increased MURC protein expression in the left ventricular myocardium. In conclusion, hypoxia in cultured rat neonatal cardiomyocytes increased MURC expression via the induction of TGF-β, SRF and the ERK pathway. These findings suggest that MURC plays a role in hypoxia-induced hypertrophy in cardiomyocytes.

  2. Anti-vascular agent Combretastatin A-4-P modulates Hypoxia Inducible Factor-1 and gene expression

    Currie Margaret J

    2006-12-01

    Full Text Available Abstract Background A functional vascular network is essential for the survival, growth and spread of solid tumours, making blood vessels a key target for therapeutic strategies. Combretastatin A-4 phosphate (CA-4-P is a tubulin-depolymerising agent in Phase II clinical trials as a vascular disrupting agent. Not much is known of the molecular effect of CA-4-P under tumour conditions. The tumour microenvironment differs markedly from that in normal tissue, specifically with respect to oxygenation (hypoxia. Gene regulation under tumour conditions is governed by hypoxia inducible factor 1 (HIF-1, controlling angiogenic and metastatic pathways. Methods We investigated the effect of CA-4-P on factors of the upstream and downstream signalling pathway of HIF-1 in vitro. Results CA-4-P treatment under hypoxia tended to reduce HIF-1 accumulation in a concentration-dependent manner, an effect which was more prominent in endothelial cells than in cancer cell lines. Conversely, CA-4-P increased HIF-1 accumulation under aerobic conditions in vitro. At these concentrations of CA-4-P under aerobic conditions, nuclear factor κB was activated via the small GTPase RhoA, and expression of the HIF-1 downstream angiogenic effector gene, vascular endothelial growth factor (VEGF-A, was increased. Conclusion Our findings advance the understanding of signal transduction pathways involved in the actions of the anti-vascular agent CA-4-P.

  3. [Effects of exogenous spermidine on Cucumis sativus L. seedlings photosynthesis under root zone hypoxia stress].

    Wang, Tian; Wang, Suping; Guo, Shirong; Sun, Yanjun

    2006-09-01

    With water culture, this paper studied the effects of exogenous spermidine (Spd) on the net photosynthetic rate (Pn), intercellular CO2 concentrations (Ci), stomatal conductance (Gs), transpiration rate (Tr), apparent quantum yield (phi c), and carboxylation efficiency (CE) of cucumber seedlings tinder hypoxia stress. The results showed that the Pn decreased gradually under hypoxia stress, and reached the minimum 10 days after by 63. 33% of the control. Compared with that of hypoxia-stressed plants, the Pn after 10 days application of exogenous Spd increased 1.25 times. A negative correlation (R2 = 0.4730 - 0.7118) was found between Pn and Ci. Gs and Tr changed in wider ranges, which decreased under hypoxia-stress, but increased under hypoxia-stress plus exogenous Spd application. There was a significant positive correlation between Gs and Tr (R2 = 0.7821 - 0.9458), but these two parameters had no significant correlation with Pn; Hypoxia stress induced a decrease of phi c and CE by 63.01% and 72.33%, respectively, while hypoxia stress plus exogenous Spd application made phi c and CE increase by 23% and 14%, respectively. The photo-inhibition of cucumber seedlings under hypoxia stress was mainly caused by non-stomatal limitation, while exogenous Spd alleviated the hypoxia stress by repairing photosynthesis system.

  4. The expanding universe of hypoxia.

    Zhang, Huafeng; Semenza, Gregg L

    2008-07-01

    Reduced oxygen availability (hypoxia) is sensed and transduced into changes in the activity or expression of cellular macromolecules. These responses impact on virtually all areas of biology and medicine. In this meeting report, we summarize major developments in the field that were presented at the 2008 Keystone Symposium on Cellular, Physiological, and Pathogenic Responses to Hypoxia.

  5. The cholesterol transporter ABCG1 links cholesterol homeostasis and tumour immunity.

    Sag, Duygu; Cekic, Caglar; Wu, Runpei; Linden, Joel; Hedrick, Catherine C

    2015-02-27

    ATP-binding cassette transporter G1 (ABCG1) promotes cholesterol efflux from cells and regulates intracellular cholesterol homeostasis. Here we demonstrate a role of ABCG1 as a mediator of tumour immunity. Abcg1(-/-) mice have dramatically suppressed subcutaneous MB49-bladder carcinoma and B16-melanoma growth and prolonged survival. We show that reduced tumour growth in Abcg1(-/-) mice is myeloid cell intrinsic and is associated with a phenotypic shift of the macrophages from a tumour-promoting M2 to a tumour-fighting M1 within the tumour. Abcg1(-/-) macrophages exhibit an intrinsic bias towards M1 polarization with increased NF-κB activation and direct cytotoxicity for tumour cells in vitro. Overall, our study demonstrates that the absence of ABCG1 inhibits tumour growth through modulation of macrophage function within the tumour, and illustrates a link between cholesterol homeostasis and cancer.

  6. Differential risk assessments from five hypoxia specific assays: The basis for biologically adapted individualized radiotherapy in advanced head and neck cancer patients

    Nordsmark, Marianne; Eriksen, Jesper Grau; Gebski, Val

    2007-01-01

    osteopontin measured by ELISA, tumour oxygenation status using pO(2) needle electrodes and tumour osteopontin, hypoxia inducible factor 1alpha (HIF-1alpha) and carboxyanhydrase 9 (CA9) by immunohistochemistry. The primary treatment was radiotherapy and the hypoxic radiosensitizer nimorazole. Loco......-regional tumour control was evaluated at 5 years. RESULTS: All five markers showed inter-tumour variability. Inter-marker correlations were inconsistent. Only plasma osteopontin inversely correlated with median tumour pO(2), (p=0.02, r=0.28) and CA9 correlated with HIF-1alpha (p...-Meier analysis high plasma osteopontin, high HIF-1alpha and high proportion of tumour pO(2)2.5mmHg (HP(2.5)) related significantly with poorer loco-regional control, whereas CA9 and tumour osteopontin failed to predict loco-regional control in this set dataset. When analyzing Hb, stage, and the five markers...

  7. Hypoxia-inducible factor 1α predicts recurrence in high-grade soft tissue sarcoma of extremities and trunk wall

    Nyström, H; Jönsson, M; Werner-Hartman, L

    2017-01-01

    BACKGROUND AND AIM: Sarcomas are of mesenchymal origin and typically show abundant tumour stroma and presence of necrosis. In search for novel biomarkers for personalised therapy, we determined the prognostic impact of stromal markers, hypoxia and neovascularity in high-grade soft tissue leiomyos...

  8. Hypoxia-controlled EphA3 marks a human endometrium-derived multipotent mesenchymal stromal cell that supports vascular growth.

    Catherine To

    Full Text Available Eph and ephrin proteins are essential cell guidance cues that orchestrate cell navigation and control cell-cell interactions during developmental tissue patterning, organogenesis and vasculogenesis. They have been extensively studied in animal models of embryogenesis and adult tissue regeneration, but less is known about their expression and function during human tissue and organ regeneration. We discovered the hypoxia inducible factor (HIF-1α-controlled expression of EphA3, an Eph family member with critical functions during human tumour progression, in the vascularised tissue of regenerating human endometrium and on isolated human endometrial multipotent mesenchymal stromal cells (eMSCs, but not in other highly vascularised human organs. EphA3 affinity-isolation from human biopsy tissue yielded multipotent CD29+/CD73+/CD90+/CD146+ eMSCs that can be clonally propagated and respond to EphA3 agonists with EphA3 phosphorylation, cell contraction, cell-cell segregation and directed cell migration. EphA3 silencing significantly inhibited the ability of transplanted eMSCs to support neovascularisation in immunocompromised mice. In accord with established roles of Eph receptors in mediating interactions between endothelial and perivascular stromal cells during mouse development, our findings suggest that HIF-1α-controlled expression of EphA3 on human MSCs functions during the hypoxia-initiated early stages of adult blood vessel formation.

  9. Characterization of tumour virus proteins, 2

    Higuchi, T.

    1977-01-01

    The structural protein in murine tumour virus P30 has been measured by radioiummunoassay. The titer of each serum was determined by using as antigen the purified Rauscher viral protein labeled with 125 iodine. Standard competition curve was constructed in order to determine the equivalent of protein to inhibit the precipitation reaction under limited antibody concentration. Competition by purified Kirsten virus suspension normal rat kidney cells, transformed-productive and transformed non-productive cells were measured in homologous and heterologous systems [pt

  10. Experimental tumour treatment

    1985-08-01

    This report of 1984 is the seventh in a series and presents that year's results of continuous studies in the domain of experimental tumour radiotherapy. In the year under review, more personnel has been available for the studies, and the scientific programmes for the assessment of acute and chronic side effects of radiotherapies have been extended. New models have been developed, among them a first system based on animal experiments, for quantifying the mucositis of the oral and pharyngeal mucosa, a limiting condition in the radiotherapy of head and throat tumours. Another significant advancement is a model for quantification of chronical damage to the ureter, which still is a serious problem in the radiotherapy of gynaecological tumours. The 1984 experimental tumour studies have been mainly devoted to the repopulation and split-dose recovery in various tumours, concentrating on dose fractionation as one of the major problems studies. Particular interest has been attached to the processes involved in treatments over several weeks with a daily effective dose of 2 Gy. (orig./MG) [de

  11. RNAi Knockdown of Hypoxia-Inducible Factor-1α Decreased the Proliferation, Migration, and Invasion of Hypoxic Hepatocellular Carcinoma Cells.

    Chen, ChengShi; Liu, Rong; Wang, JianHua; Yan, ZhiPing; Qian, Sheng; Zhang, Wei

    2015-04-01

    The obstruction of hepatic arterial blood flow results in tumor tissue hypoxia and elevated expression of hypoxia-inducible factor-1alpha (HIF-1α). Our study evaluated whether lentivirus-mediated short interference RNA against HIF-1α inhibits proliferation, invasion, and migration of hepatocellular carcinoma (HCC) cells under hypoxia. RNA interference knockdown of HIF-1α was achieved by HIF-1α-directed lentiviral shRNA, in a rat HCC cell line cultured under hypoxia condition for varying length of times. The expression levels of HIF-1α and vascular endothelial growth factor were examined using reverse transcription polymerase chain reaction and western blot analyses. Cell proliferation, migration, and invasion were measured by cell viability, transwell migration, and invasion assays, respectively. Inhibition of HIF-1α expression by shRNA suppressed vascular endothelial growth factor mRNA and protein levels under both normoxia and hypoxia. It also suppressed cell migration and invasion, which were enhanced under hypoxic conditions. RNAi knockdown of HIF-1α further suppressed hypoxia-mediated inhibition of the cell proliferation. These data suggest that shRNA of HIF-1α could antagonize the hypoxia-mediated increase in hepatic cancer cell migration and invasion, and synergize with hypoxia to inhibit the cell proliferation in HCC cells.

  12. Hypoxia silences retrotrapezoid nucleus respiratory chemoreceptors via alkalosis.

    Basting, Tyler M; Burke, Peter G R; Kanbar, Roy; Viar, Kenneth E; Stornetta, Daniel S; Stornetta, Ruth L; Guyenet, Patrice G

    2015-01-14

    In conscious mammals, hypoxia or hypercapnia stimulates breathing while theoretically exerting opposite effects on central respiratory chemoreceptors (CRCs). We tested this theory by examining how hypoxia and hypercapnia change the activity of the retrotrapezoid nucleus (RTN), a putative CRC and chemoreflex integrator. Archaerhodopsin-(Arch)-transduced RTN neurons were reversibly silenced by light in anesthetized rats. We bilaterally transduced RTN and nearby C1 neurons with Arch (PRSx8-ArchT-EYFP-LVV) and measured the cardiorespiratory consequences of Arch activation (10 s) in conscious rats during normoxia, hypoxia, or hyperoxia. RTN photoinhibition reduced breathing equally during non-REM sleep and quiet wake. Compared with normoxia, the breathing frequency reduction (Δf(R)) was larger in hyperoxia (65% FiO2), smaller in 15% FiO2, and absent in 12% FiO2. Tidal volume changes (ΔV(T)) followed the same trend. The effect of hypoxia on Δf(R) was not arousal-dependent but was reversed by reacidifying the blood (acetazolamide; 3% FiCO2). Δf(R) was highly correlated with arterial pH up to arterial pH (pHa) 7.5 with no frequency inhibition occurring above pHa 7.53. Blood pressure was minimally reduced suggesting that C1 neurons were very modestly inhibited. In conclusion, RTN neurons regulate eupneic breathing about equally during both sleep and wake. RTN neurons are the first putative CRCs demonstrably silenced by hypocapnic hypoxia in conscious mammals. RTN neurons are silent above pHa 7.5 and increasingly active below this value. During hyperoxia, RTN activation maintains breathing despite the inactivity of the carotid bodies. Finally, during hypocapnic hypoxia, carotid body stimulation increases breathing frequency via pathways that bypass RTN. Copyright © 2015 the authors 0270-6474/15/350527-17$15.00/0.

  13. Hypoxia-driven angiogenesis: role of tip cells and extracellular matrix scaffolding.

    Germain, Stéphane; Monnot, Catherine; Muller, Laurent; Eichmann, Anne

    2010-05-01

    Angiogenesis is a highly coordinated tissue remodeling process leading to blood vessel formation. Hypoxia triggers angiogenesis via induction of expression of growth factors such as vascular endothelial growth factor (VEGF). VEGF instructs endothelial cells to form tip cells, which lead outgrowing capillary sprouts, whereas Notch signaling inhibits sprout formation. Basement membrane deposition and mechanical cues from the extracellular matrix (ECM) induced by hypoxia may participate to coordinated vessel sprouting in conjunction with the VEGF and Notch signaling pathways. Hypoxia regulates ECM composition, deposition, posttranslational modifications and rearrangement. In particular, hypoxia-driven vascular remodeling is dynamically regulated through modulation of ECM-modifying enzyme activities that eventually affect both matricellular proteins and growth factor availability. Better understanding of the complex interplay between endothelial cells and soluble growth factors and mechanical factors from the ECM will certainly have significant implications for understanding the regulation of developmental and pathological angiogenesis driven by hypoxia.

  14. Coastal hypoxia and sediment biogeochemistry

    J. J. Middelburg

    2009-07-01

    Full Text Available The intensity, duration and frequency of coastal hypoxia (oxygen concentration <63 μM are increasing due to human alteration of coastal ecosystems and changes in oceanographic conditions due to global warming. Here we provide a concise review of the consequences of coastal hypoxia for sediment biogeochemistry. Changes in bottom-water oxygen levels have consequences for early diagenetic pathways (more anaerobic at expense of aerobic pathways, the efficiency of re-oxidation of reduced metabolites and the nature, direction and magnitude of sediment-water exchange fluxes. Hypoxia may also lead to more organic matter accumulation and burial and the organic matter eventually buried is also of higher quality, i.e. less degraded. Bottom-water oxygen levels also affect the organisms involved in organic matter processing with the contribution of metazoans decreasing as oxygen levels drop. Hypoxia has a significant effect on benthic animals with the consequences that ecosystem functions related to macrofauna such as bio-irrigation and bioturbation are significantly affected by hypoxia as well. Since many microbes and microbial-mediated biogeochemical processes depend on animal-induced transport processes (e.g. re-oxidation of particulate reduced sulphur and denitrification, there are indirect hypoxia effects on biogeochemistry via the benthos. Severe long-lasting hypoxia and anoxia may result in the accumulation of reduced compounds in sediments and elimination of macrobenthic communities with the consequences that biogeochemical properties during trajectories of decreasing and increasing oxygen may be different (hysteresis with consequences for coastal ecosystem dynamics.

  15. The influence of the oestrous cycle on the radiation response of solid tumours

    Swann, Patricia R.

    degree of transient perfusion in the tumours was assessed. This used a fluorescent double-staining technique by intravenous injection of the fluorescent dyes Hoechst 33342 and diheptyloxacarbocyanine with a 20 minute interval between dye administrations. These dyes stain functional blood vessels and can be viewed under the fluorescent microscope. Regions of vasculature stained with both dyes indicate constant perfusion throughout the experiment, whereas only one dye indicates mismatch or transient perfusion. Tumour vasculature that experiences intermittent perfusion will result in areas of acute hypoxia that can impact on the radiation response of the tumour. The results shows that in oestrus, KHT and RIF-1 tumours showed the lowest proportion of transient perfusion, where as this oestrous stage produced the most mismatch perfusion in the SCCvii tumour. The metastatic spread of KHT tumour cells was influenced by the oestrous cycle. Fractionated irradiation of a primary tumour during metoestrus and dioestrus showed less tumour control by radiation when compared to tumours irradiated in oestrus. The intravenous injection of KHT tumour cells in oestrus and dioestrus also produced a less metastatic burden to the lungs than cells injected in pro-oestrus and metoestrus. The results of this project suggest that there are oestrous stage dependent effects that could alter the radiation response of tumours.

  16. Effect of low-frequency low-intensity ultrasound with microbubbles on prostate cancer hypoxia.

    Hou, Rui; Xu, Yanjun; Lu, Qijie; Zhang, Yang; Hu, Bing

    2017-10-01

    Angiogenesis plays an important role in tumor growth, invasiveness, and metastasis. It is well established that prostate cancer is exposed to fluctuating oxygen tensions and both acute and chronic hypoxia exist, and these conditions can upregulate angiogenesis-associated proteins such as hypoxia-inducible factor 1 alpha and vascular endothelial growth factor A. Low-frequency low-intensity ultrasound with microbubbles can induce obvious microvessel damage in tumors, cause cell necrosis or apoptosis. However, there is no information about whether the blocking blood effect of low-frequency low-intensity ultrasound with microbubbles has an influence on hypoxia environment of prostate cancer. Therefore, we investigated the impact of different low-frequency low-intensity ultrasound with microbubbles radiation times on prostate tumors, observed the change in the hypoxia-inducible factor 1 alpha and vascular endothelial growth factor A protein levels, as well as cell proliferation, apoptosis, and tumor volume. The results indicated that as the radiation was repeated four times on each treatment day, the effects of interruption were durable, the cell proliferation was inhibited, and apoptosis was promoted, and the hypoxia-inducible factor 1 alpha and vascular endothelial growth factor A expression levels were lower in the treatment group than in the control group. When the radiation was carried out once per treatment day, the hypoxia response was stimulated, the hypoxia-inducible factor 1 alpha and vascular endothelial growth factor A expression levels were higher compared with the control group, and cell proliferation was promoted. In addition, the tumor volume increased obviously in the hypoxia-stimulated group, whereas tumors grew slowly in the hypoxia-suppressed group. The results of this work demonstrated that under the same conditions, different radiation times of low-frequency low-intensity ultrasound with microbubbles affect the hypoxia response differently, and the

  17. Anti-tumour therapeutic efficacy of OX40L in murine tumour model.

    Ali, Selman A; Ahmad, Murrium; Lynam, June; McLean, Cornelia S; Entwisle, Claire; Loudon, Peter; Choolun, Esther; McArdle, Stephanie E B; Li, Geng; Mian, Shahid; Rees, Robert C

    2004-09-09

    OX40 ligand (OX40L), a member of TNF superfamily, is a co-stimulatory molecule involved in T cell activation. Systemic administration of mOX40L fusion protein significantly inhibited the growth of experimental lung metastasis and subcutaneous (s.c.) established colon (CT26) and breast (4T1) carcinomas. Vaccination with OX40L was significantly enhanced by combination treatment with intra-tumour injection of a disabled infectious single cycle-herpes simplex virus (DISC-HSV) vector encoding murine granulocyte macrophage-colony stimulating factor (mGM-CSF). Tumour rejection in response to OX40L therapy required functional CD4+ and CD8+ T cells and correlated with splenocyte cytotoxic T lymphocytes (CTLs) activity against the AH-1 gp70 peptide of the tumour associated antigen expressed by CT26 cells. These results demonstrate the potential role of the OX40L in cancer immunotherapy.

  18. Synovial tissue hypoxia and inflammation in vivo.

    Ng, C T

    2012-02-01

    INTRODUCTION: Hypoxia is a microenvironmental feature in the inflamed joint, which promotes survival advantage for cells. The aim of this study was to examine the relationship of partial oxygen pressure in the synovial tissue (tPO(2)) in patients with inflammatory arthritis with macroscopic\\/microscopic inflammation and local levels of proinflammatory mediators. METHODS: Patients with inflammatory arthritis underwent full clinical assessment and video arthroscopy to quantify macroscopic synovitis and measure synovial tPO(2) under direct visualisation. Cell specific markers (CD3 (T cells), CD68 (macrophages), Ki67 (cell proliferation) and terminal deoxynucleotidyl transferase dUTP nick end labelling (cell apoptosis)) were quantified by immunohistology. In vitro migration was assessed in primary and normal synoviocytes (synovial fibroblast cells (SFCs)) using a wound repair scratch assay. Levels of tumour necrosis factor alpha (TNFalpha), interleukin 1beta (IL1beta), interferon gamma (IFNgamma), IL6, macrophage inflammatory protein 3alpha (MIP3alpha) and IL8 were quantified, in matched serum and synovial fluid, by multiplex cytokine assay and ELISA. RESULTS: The tPO(2) was 22.5 (range 3.2-54.1) mm Hg and correlated inversely with macroscopic synovitis (r=-0.421, p=0.02), sublining CD3 cells (-0.611, p<0.01) and sublining CD68 cells (r=-0.615, p<0.001). No relationship with cell proliferation or apoptosis was found. Primary and normal SFCs exposed to 1% and 3% oxygen (reflecting the median tPO(2) in vivo) induced cell migration. This was coupled with significantly higher levels of synovial fluid tumour necrosis factor alpha (TNFalpha), IL1beta, IFNgamma and MIP3alpha in patients with tPO(2) <20 mm Hg (all p values <0.05). CONCLUSIONS: This is the first study to show a direct in vivo correlation between synovial tPO(2), inflammation and cell migration, thus it is proposed that hypoxia is a possible primary driver of inflammatory processes in the arthritic joint.

  19. Hypoxia promotes uveal melanoma invasion through enhanced Notch and MAPK activation.

    Laura Asnaghi

    Full Text Available The transcriptional response promoted by hypoxia-inducible factors has been associated with metastatic spread of uveal melanoma. We found expression of hypoxia-inducible factor 1α (HIF-1α protein in well-vascularized tumor regions as well as in four cell lines grown in normoxia, thus this pathway may be important even in well-oxygenated uveal melanoma cells. HIF-1α protein accumulation in normoxia was inhibited by rapamycin. As expected, hypoxia (1% pO2 further induced HIF-1α protein levels along with its target genes VEGF and LOX. Growth in hypoxia significantly increased cellular invasion of all 5 uveal melanoma lines tested, as did the introduction of an oxygen-insensitive HIF-1α mutant into Mel285 cells with low HIF-1α baseline levels. In contrast, HIF-1α knockdown using shRNA significantly decreased growth in hypoxia, and reduced by more than 50% tumor invasion in four lines with high HIF-1α baseline levels. Pharmacologic blockade of HIF-1α protein expression using digoxin dramatically suppressed cellular invasion both in normoxia and in hypoxia. We found that Notch pathway components, including Jag1-2 ligands, Hes1-Hey1 targets and the intracellular domain of Notch1, were increased in hypoxia, as well as the phosphorylation levels of Erk1-2 and Akt. Pharmacologic and genetic inhibition of Notch largely blocked the hypoxic induction of invasion as did the pharmacologic suppression of Erk1-2 activity. In addition, the increase in Erk1-2 and Akt phosphorylation by hypoxia was partially reduced by inhibiting Notch signaling. Our findings support the functional importance of HIF-1α signaling in promoting the invasive capacity of uveal melanoma cells in both hypoxia and normoxia, and suggest that pharmacologically targeting HIF-1α pathway directly or through blockade of Notch or Erk1-2 pathways can slow tumor spread.

  20. Hypoxia-induced p53 modulates both apoptosis and radiosensitivity via AKT

    Leszczynska, Katarzyna B.; Foskolou, Iosifina P.; Abraham, Aswin G.; Anbalagan, Selvakumar; Tellier, Céline; Haider, Syed; Span, Paul N.; O’Neill, Eric E.; Buffa, Francesca M.; Hammond, Ester M.

    2015-01-01

    Restoration of hypoxia-induced apoptosis in tumors harboring p53 mutations has been proposed as a potential therapeutic strategy; however, the transcriptional targets that mediate hypoxia-induced p53-dependent apoptosis remain elusive. Here, we demonstrated that hypoxia-induced p53-dependent apoptosis is reliant on the DNA-binding and transactivation domains of p53 but not on the acetylation sites K120 and K164, which, in contrast, are essential for DNA damage–induced, p53-dependent apoptosis. Evaluation of hypoxia-induced transcripts in multiple cell lines identified a group of genes that are hypoxia-inducible proapoptotic targets of p53, including inositol polyphosphate-5-phosphatase (INPP5D), pleckstrin domain–containing A3 (PHLDA3), sulfatase 2 (SULF2), B cell translocation gene 2 (BTG2), cytoplasmic FMR1-interacting protein 2 (CYFIP2), and KN motif and ankyrin repeat domains 3 (KANK3). These targets were also regulated by p53 in human cancers, including breast, brain, colorectal, kidney, bladder, and melanoma cancers. Downregulation of these hypoxia-inducible targets associated with poor prognosis, suggesting that hypoxia-induced apoptosis contributes to p53-mediated tumor suppression and treatment response. Induction of p53 targets, PHLDA3, and a specific INPP5D transcript mediated apoptosis in response to hypoxia through AKT inhibition. Moreover, pharmacological inhibition of AKT led to apoptosis in the hypoxic regions of p53-deficient tumors and consequently increased radiosensitivity. Together, these results identify mediators of hypoxia-induced p53-dependent apoptosis and suggest AKT inhibition may improve radiotherapy response in p53-deficient tumors. PMID:25961455

  1. Effect of acadesine on breast cancer cells under hypoxia

    A. M. Shcherbakov

    2017-01-01

    Full Text Available The riboside derivative acadesine (5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside is currently being tested in clinical trials as a promising anti-tumor drug. Intracellular target of acadesine is adenosine monophosphate-activated protein kinase (АМРК, an important regulatory molecule of energy metabolism. It is expected that acadesine would be active in tumors under hypoxia conditions. In normoxia (cells incubated in 21 % oxygen, acadesine inhibited proliferation and induced cell death of breast adenocarcinoma, including the triple negative breast cancer line. When oxygen partial pressure was decreased to 1 % (experimental hypoxia, acadesine inhibited activation of reporter construct responsive to HIF-1α (hypoxia inducible factor 1 alpha transcription factor. This effect was observed for acadesine in concentrations close to cytotoxic. Acadesine retained cytotoxicity under hypoxia and decreased the survival of the MDA-MB-231 cell line when used in combination with cisplatin. These results considerably widen acadesine’s field of application and allow to assume its efficacy in chemotherapy combination regimens for breast cancer, including the tumors with low oxygenation.

  2. Trichostatin A enhances estrogen receptor-alpha repression in MCF-7 breast cancer cells under hypoxia

    Noh, Hyunggyun; Park, Joonwoo; Shim, Myeongguk; Lee, YoungJoo

    2016-01-01

    Estrogen receptor (ER) is a crucial determinant of resistance to endocrine therapy, which may change during the progression of breast cancer. We previously showed that hypoxia induces ESR1 gene repression and ERα protein degradation via proteasome-mediated pathway in breast cancer cells. HDAC plays important roles in the regulation of histone and non-histone protein post-translational modification. HDAC inhibitors can induce epigenetic changes and have therapeutic potential for targeting various cancers. Trichostatin A exerts potent antitumor activities against breast cancer cells in vitro and in vivo. In this report, we show that TSA augments ESR1 gene repression at the transcriptional level and downregulates ERα protein expression under hypoxic conditions through a proteasome-mediated pathway. TSA-induced estrogen response element-driven reporter activity in the absence of estrogen was synergistically enhanced under hypoxia; however, TSA inhibited cell proliferation under both normoxia and hypoxia. Our data show that the hypoxia-induced repression of ESR1 and degradation of ERα are enhanced by concomitant treatment with TSA. These findings expand our understanding of hormone responsiveness in the tumor microenvironment; however, additional in-depth studies are required to elucidate the detailed mechanisms of TSA-induced ERα regulation under hypoxia. - Highlights: • TSA augments ESR1 gene repression at the transcriptional level under hypoxia. • TSA downregulates ERα protein expression under hypoxia. • TSA-induced ERα regulation under hypoxia is essential for understanding the behavior and progression of breast cancer.

  3. Trichostatin A enhances estrogen receptor-alpha repression in MCF-7 breast cancer cells under hypoxia

    Noh, Hyunggyun; Park, Joonwoo; Shim, Myeongguk; Lee, YoungJoo, E-mail: yjlee@sejong.ac.kr

    2016-02-12

    Estrogen receptor (ER) is a crucial determinant of resistance to endocrine therapy, which may change during the progression of breast cancer. We previously showed that hypoxia induces ESR1 gene repression and ERα protein degradation via proteasome-mediated pathway in breast cancer cells. HDAC plays important roles in the regulation of histone and non-histone protein post-translational modification. HDAC inhibitors can induce epigenetic changes and have therapeutic potential for targeting various cancers. Trichostatin A exerts potent antitumor activities against breast cancer cells in vitro and in vivo. In this report, we show that TSA augments ESR1 gene repression at the transcriptional level and downregulates ERα protein expression under hypoxic conditions through a proteasome-mediated pathway. TSA-induced estrogen response element-driven reporter activity in the absence of estrogen was synergistically enhanced under hypoxia; however, TSA inhibited cell proliferation under both normoxia and hypoxia. Our data show that the hypoxia-induced repression of ESR1 and degradation of ERα are enhanced by concomitant treatment with TSA. These findings expand our understanding of hormone responsiveness in the tumor microenvironment; however, additional in-depth studies are required to elucidate the detailed mechanisms of TSA-induced ERα regulation under hypoxia. - Highlights: • TSA augments ESR1 gene repression at the transcriptional level under hypoxia. • TSA downregulates ERα protein expression under hypoxia. • TSA-induced ERα regulation under hypoxia is essential for understanding the behavior and progression of breast cancer.

  4. Imaging of hypoxia with 18F-FAZA PET in patients with locally advanced non-small cell lung cancer treated with definitive chemoradiotherapy

    Trinkaus, Mateya E.; Rischin, Danny; Blum, Rob

    2013-01-01

    For many cancers, tumour hypoxia is an adverse prognostic factor, and increases chemoradiation resistance; its importance in non-small cell lung cancer (NSCLC) is unproven. This study evaluated tumoural hypoxia using fluoroazomycin arabinoside ( 18 F-FAZA) positron emission tomography (PET) scans among patients with locoregionally advanced NSCLC treated with definitive chemoradiation. Patients with stage IIIA-IIIB NSCLC underwent 18 F-FAZA PET scans and 18 F-2-deoxyglucose (FDG)-PET scans within 4 weeks of commencing and 8 weeks following conventionally-fractionated concurrent platinum-based chemoradiation (60Gy). Intra-lesional hypoxic volumes of the primary and nodal masses were compared with FDG-PET metabolic volumes. Baseline tumoural hypoxia was correlated with disease free survival (DFS). Seventeen patients underwent pre-treatment 18 F-FAZA PET and FDG-PET scans. Intra-lesional hypoxia was identified on 11 scans (65%). Baseline lesional hypoxic volumes were consistently smaller than FDG-PET volumes (P=0.012). There was no statistical difference between the mean FDG-PET volumes in patients with or without baseline hypoxia (P=0.38). Eight patients with baseline hypoxia had post treatment 18 F-FAZA scans and 6 of these (75%) had resolution of imageable hypoxia following chemoradiation. The DFS was not significantly different between the hypoxic or non-hypoxic groups (median 0.8 years and 1.3 years respectively, P=0.42). Intra-lesional hypoxia, as detected by 18 F-FAZA PET, was present in 65% of patients with locally-advanced NSCLC and resolved in the majority of patients following chemoradiation. Larger studies are required to evaluate the prognostic significance of the presence and resolution of hypoxia assessed by PET in NSCLC.

  5. Genetically modified tumour vaccines

    Bubeník, Jan

    2005-01-01

    Roč. 3, Suppl. 1 (2005), S7 ISSN 1214-021X. [Cells VI - Biological Days /18./. 24.10.2005-26.10.2005, České Budějovice] Institutional research plan: CEZ:AV0Z50520514 Keywords : tumour vaccines * HPV16 Subject RIV: EC - Immunology

  6. Putting tumours in context.

    Bissell, M J; Radisky, D

    2001-10-01

    The interactions between cancer cells and their micro- and macroenvironment create a context that promotes tumour growth and protects it from immune attack. The functional association of cancer cells with their surrounding tissues forms a new 'organ' that changes as malignancy progresses. Investigation of this process might provide new insights into the mechanisms of tumorigenesis and could also lead to new therapeutic targets.

  7. Biliverdin reductase/bilirubin mediates the anti-apoptotic effect of hypoxia in pulmonary arterial smooth muscle cells through ERK1/2 pathway

    Song, Shasha; Wang, Shuang; Ma, Jun; Yao, Lan; Xing, Hao; Zhang, Lei; Liao, Lin; Zhu, Daling

    2013-01-01

    Inhibition of pulmonary arterial smooth muscle cell (PASMC) apoptosis induced by hypoxia plays an important role in pulmonary arterial remodeling leading to aggravate hypoxic pulmonary arterial hypertension. However, the mechanisms of hypoxia acting on PASMC apoptosis remain exclusive. Biliverdin reductase (BVR) has many essential biologic roles in physiological and pathological processes. Nevertheless, it is unclear whether the hypoxia-induced inhibition on PASMC apoptosis is mediated by BVR. In the present work, we found BVR majorly localized in PASMCs and was up-regulated in levels of protein and mRNA by hypoxia. Then we studied the contribution of BVR to anti-apoptotic response of hypoxia in PASMCs. Our results showed that siBVR, blocking generation of bilirubin, reversed the effect of hypoxia on enhancing cell survival and apoptotic protein (Bcl-2, procasepase-9, procasepase-3) expression, preventing nuclear shrinkage, DNA fragmentation and mitochondrial depolarization in starved PASMCs, which were recovered by exogenous bilirubin. Moreover, the inhibitory effect of bilirubin on PASMC apoptosis under hypoxic condition was blocked by the inhibitor of ERK1/2 pathway. Taken together, our data indicate that BVR contributes to the inhibitory process of hypoxia on PASMC apoptosis, which is mediated by bilirubin through ERK1/2 pathway. Highlights: • BVR expresses in PASMC and is up-regulated by hypoxia in protein and mRNA levels. • BVR/bilirubin contribute to the inhibitive process of hypoxia on PASMC apoptosis. • Bilirubin protects PASMC from apoptosis under hypoxia via ERK1/2 pathway

  8. Biliverdin reductase/bilirubin mediates the anti-apoptotic effect of hypoxia in pulmonary arterial smooth muscle cells through ERK1/2 pathway

    Song, Shasha [Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical, University (Daqing), Daqing 163319 (China); Wang, Shuang [Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical, University (Daqing), Daqing 163319 (China); Biopharmaceutical Key Laboratory of Heilongjiang Province, Harbin 150081 (China); Ma, Jun; Yao, Lan; Xing, Hao; Zhang, Lei; Liao, Lin [Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical, University (Daqing), Daqing 163319 (China); Zhu, Daling, E-mail: dalingz@yahoo.com [Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical, University (Daqing), Daqing 163319 (China); Biopharmaceutical Key Laboratory of Heilongjiang Province, Harbin 150081 (China)

    2013-08-01

    Inhibition of pulmonary arterial smooth muscle cell (PASMC) apoptosis induced by hypoxia plays an important role in pulmonary arterial remodeling leading to aggravate hypoxic pulmonary arterial hypertension. However, the mechanisms of hypoxia acting on PASMC apoptosis remain exclusive. Biliverdin reductase (BVR) has many essential biologic roles in physiological and pathological processes. Nevertheless, it is unclear whether the hypoxia-induced inhibition on PASMC apoptosis is mediated by BVR. In the present work, we found BVR majorly localized in PASMCs and was up-regulated in levels of protein and mRNA by hypoxia. Then we studied the contribution of BVR to anti-apoptotic response of hypoxia in PASMCs. Our results showed that siBVR, blocking generation of bilirubin, reversed the effect of hypoxia on enhancing cell survival and apoptotic protein (Bcl-2, procasepase-9, procasepase-3) expression, preventing nuclear shrinkage, DNA fragmentation and mitochondrial depolarization in starved PASMCs, which were recovered by exogenous bilirubin. Moreover, the inhibitory effect of bilirubin on PASMC apoptosis under hypoxic condition was blocked by the inhibitor of ERK1/2 pathway. Taken together, our data indicate that BVR contributes to the inhibitory process of hypoxia on PASMC apoptosis, which is mediated by bilirubin through ERK1/2 pathway. Highlights: • BVR expresses in PASMC and is up-regulated by hypoxia in protein and mRNA levels. • BVR/bilirubin contribute to the inhibitive process of hypoxia on PASMC apoptosis. • Bilirubin protects PASMC from apoptosis under hypoxia via ERK1/2 pathway.

  9. Chronic Intermittent Hypoxia Induces Atherosclerosis

    Savransky, Vladimir; Nanayakkara, Ashika; Li, Jianguo; Bevans, Shannon; Smith, Philip L.; Rodriguez, Annabelle; Polotsky, Vsevolod Y.

    2007-01-01

    Rationale: Obstructive sleep apnea, a condition leading to chronic intermittent hypoxia (CIH), is associated with hyperlipidemia, atherosclerosis, and a high cardiovascular risk. A causal link between obstructive sleep apnea and atherosclerosis has not been established.

  10. Reflex bradycardia does not influence oxygen consumption during hypoxia in the European eel (Anguilla anguilla)

    Iversen, Nina Kerting; McKenzie, David; Malte, H.

    2010-01-01

    the bradycardia on oxygen consumption (MO2), standard metabolic rate (SMR) and the critical oxygen partial pressure for regulation of SMR in hypoxia (Pcrit) in European eels Anguilla anguilla (mean ± SEM mass 528 ± 36 g; n = 14). Eels were instrumented with a Transonic flow probe around the ventral aorta......Most teleost fish reduce heart rate when exposed to acute hypoxia. This hypoxic bradycardia has been characterised for many fish species, but it remains uncertain whether this reflex contributes to the maintenance of oxygen uptake in hypoxia. Here we describe the effects of inhibiting...

  11. Hypoxia attenuates inflammatory mediators production induced by Acanthamoeba via Toll-like receptor 4 signaling in human corneal epithelial cells

    Pan, Hong; Wu, Xinyi

    2012-01-01

    Highlights: ► Hypoxia attenuates Acanthamoeba-induced the production of IL-8 and IFN-β. ► Hypoxia inhibits TLR4 expression in a time-dependent manner in HCECs. ► Hypoxia inhibits Acanthamoeba-induced the activation of NF-κB and ERK1/2 in HCECs. ► Hypoxia decreases Acanthamoeba-induced inflammatory response via TLR4 signaling. ► LPS-induced the secretion of IL-6 and IL-8 is abated by hypoxia via TLR4 signaling. -- Abstract: Acanthamoeba keratitis (AK) is a vision-threatening corneal infection that is intimately associated with contact lens use which leads to hypoxic conditions on the corneal surface. However, the effect of hypoxia on the Acanthamoeba-induced host inflammatory response of corneal epithelial cells has not been studied. In the present study, we investigated the effect of hypoxia on the Acanthamoeba-induced production of inflammatory mediators interleukin-8 (IL-8) and interferon-β (IFN-β) in human corneal epithelial cells and then evaluated its effects on the Toll-like receptor 4 (TLR4) signaling, including TLR4 and myeloid differentiation primary response gene (88) (MyD88) expression as well as the activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and extracellular signal-regulated kinases 1/2 (ERK1/2). We then studied the effect of hypoxia on a TLR4-specific inflammatory response triggered by the TLR4 ligand lipopolysaccharide (LPS). Our data showed that hypoxia significantly decreased the production of IL-8 and IFN-β. Furthermore, hypoxia attenuated Acanthamoeba-triggered TLR4 expression as well as the activation of NF-κB and ERK1/2, indicating that hypoxia abated Acanthamoeba-induced inflammatory responses by affecting TLR4 signaling. Hypoxia also inhibited LPS-induced IL-6 and IL-8 secretion, myeloid differentiation primary response gene (88) MyD88 expression and NF-κB activation, confirming that hypoxia suppressed the LPS-induced inflammatory response by affecting TLR4 signaling. In conclusion

  12. Hypoxia, Oxidative Stress and Fat

    Nikolaus Netzer

    2015-06-01

    Full Text Available Metabolic disturbances in white adipose tissue in obese individuals contribute to the pathogenesis of insulin resistance and the development of type 2 diabetes mellitus. Impaired insulin action in adipocytes is associated with elevated lipolysis and increased free fatty acids leading to ectopic fat deposition in liver and skeletal muscle. Chronic adipose tissue hypoxia has been suggested to be part of pathomechanisms causing dysfunction of adipocytes. Hypoxia can provoke oxidative stress in human and animal adipocytes and reduce the production of beneficial adipokines, such as adiponectin. However, time-dose responses to hypoxia relativize the effects of hypoxic stress. Long-term exposure of fat cells to hypoxia can lead to the production of beneficial substances such as leptin. Knowledge of time-dose responses of hypoxia on white adipose tissue and the time course of generation of oxidative stress in adipocytes is still scarce. This paper reviews the potential links between adipose tissue hypoxia, oxidative stress, mitochondrial dysfunction, and low-grade inflammation caused by adipocyte hypertrophy, macrophage infiltration and production of inflammatory mediators.

  13. Targeting the erythropoietin receptor on glioma cells reduces tumour growth

    Peres, Elodie A.; Valable, Samuel; Guillamo, Jean-Sebastien; Marteau, Lena; Bernaudin, Jean-Francois; Roussel, Simon; Lechapt-Zalcman, Emmanuele; Bernaudin, Myriam; Petit, Edwige

    2011-01-01

    Hypoxia has been shown to be one of the major events involved in EPO expression. Accordingly, EPO might be expressed by cerebral neoplastic cells, especially in glioblastoma, known to be highly hypoxic tumours. The expression of EPOR has been described in glioma cells. However, data from the literature remain descriptive and controversial. On the basis of an endogenous source of EPO in the brain, we have focused on a potential role of EPOR in brain tumour growth. In the present study, with complementary approaches to target EPO/EPOR signalling, we demonstrate the presence of a functional EPO/EPOR system on glioma cells leading to the activation of the ERK pathway. This EPO/EPOR system is involved in glioma cell proliferation in vitro. In vivo, we show that the down-regulation of EPOR expression on glioma cells reduces tumour growth and enhances animal survival. Our results support the hypothesis that EPOR signalling in tumour cells is involved in the control of glioma growth.

  14. Transcriptome sequencing revealed differences in the response of renal cancer cells to hypoxia and CoCl2 treatment [version 1; referees: 2 approved

    Nadezhda Zhigalova

    2015-12-01

    Full Text Available Human cancer cells are subjected to hypoxic conditions in many tumours. Hypoxia causes alterations in the glycolytic pathway activation through stabilization of hypoxia-inducible factor 1. Currently, two approaches are commonly used to model hypoxia: an alternative to generating low-oxygen conditions in an incubator, cells can be treated with CoCl2. We performed RNA-seq experiments to study transcriptomes of human Caki-1 cells under real hypoxia and after CoCl2 treatment. Despite causing transcriptional changes of a much higher order of magnitude for the genes in the hypoxia regulation pathway, CoCl2 treatment fails to induce alterations in the glycolysis / gluconeogenesis pathway. Moreover, CoCl2 caused aberrant activation of other oxidoreductases in glycine, serine and threonine metabolism pathways.

  15. Aberrant methylation and associated transcriptional mobilization of Alu elements contributes to genomic instability in hypoxia.

    Pal, Arnab; Srivastava, Tapasya; Sharma, Manish K; Mehndiratta, Mohit; Das, Prerna; Sinha, Subrata; Chattopadhyay, Parthaprasad

    2010-11-01

    Hypoxia is an integral part of tumorigenesis and contributes extensively to the neoplastic phenotype including drug resistance and genomic instability. It has also been reported that hypoxia results in global demethylation. Because a majority of the cytosine-phosphate-guanine (CpG) islands are found within the repeat elements of DNA, and are usually methylated under normoxic conditions, we suggested that retrotransposable Alu or short interspersed nuclear elements (SINEs) which show altered methylation and associated changes of gene expression during hypoxia, could be associated with genomic instability. U87MG glioblastoma cells were cultured in 0.1% O₂ for 6 weeks and compared with cells cultured in 21% O₂ for the same duration. Real-time PCR analysis showed a significant increase in SINE and reverse transcriptase coding long interspersed nuclear element (LINE) transcripts during hypoxia. Sequencing of bisulphite treated DNA as well as the Combined Bisulfite Restriction Analysis (COBRA) assay showed that the SINE loci studied underwent significant hypomethylation though there was patchy hypermethylation at a few sites. The inter-alu PCR profile of DNA from cells cultured under 6-week hypoxia, its 4-week revert back to normoxia and 6-week normoxia showed several changes in the band pattern indicating increased alu mediated genomic alteration. Our results show that aberrant methylation leading to increased transcription of SINE and reverse transcriptase associated LINE elements could lead to increased genomic instability in hypoxia. This might be a cause of genetic heterogeneity in tumours especially in variegated hypoxic environment and lead to a development of foci of more aggressive tumour cells. © 2009 The Authors Journal compilation © 2010 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.

  16. The HYP-RT Hypoxic Tumour Radiotherapy Algorithm and Accelerated Repopulation Dose per Fraction Study

    W. M. Harriss-Phillips

    2012-01-01

    Full Text Available The HYP-RT model simulates hypoxic tumour growth for head and neck cancer as well as radiotherapy and the effects of accelerated repopulation and reoxygenation. This report outlines algorithm design, parameterisation and the impact of accelerated repopulation on the increase in dose/fraction needed to control the extra cell propagation during accelerated repopulation. Cell kill probabilities are based on Linear Quadratic theory, with oxygenation levels and proliferative capacity influencing cell death. Hypoxia is modelled through oxygen level allocation based on pO2 histograms. Accelerated repopulation is modelled by increasing the stem cell symmetrical division probability, while the process of reoxygenation utilises randomised pO2 increments to the cell population after each treatment fraction. Propagation of 108 tumour cells requires 5–30 minutes. Controlling the extra cell growth induced by accelerated repopulation requires a dose/fraction increase of 0.5–1.0 Gy, in agreement with published reports. The average reoxygenation pO2 increment of 3 mmHg per fraction results in full tumour reoxygenation after shrinkage to approximately 1 mm. HYP-RT is a computationally efficient model simulating tumour growth and radiotherapy, incorporating accelerated repopulation and reoxygenation. It may be used to explore cell kill outcomes during radiotherapy while varying key radiobiological and tumour specific parameters, such as the degree of hypoxia.

  17. Hypoxia and the initiation of erythropoietin production. [Rats

    Schooley, J.C.; Mahlmann, L.J.

    1975-01-01

    The initiation of erythropoietin production in rats by hypoxia is dependent upon the magnitude of the hypoxic exposure, the position of the oxygen dissociation curve at the time of the hypoxic exposure, and the animal's endocrine status. Normal male rats produce more erythropoietin and elevate their intraerythrocytic 2,3-DPG levels more than female rats exposed to the same degree of hypoxia. Hypophysectomized rats produce erythropoietin following severe hypoxic exposure, but do not elevate their 2,3-DPG levels above control values. Respiratory acidosis in rats produced by breathing 10 percent CO/sub 2/ or by the injection of acetazolamide inhibits the initiation of erythropoietin production by hypoxic environments, but this inhibition is minimal in animals with metabolic acidosis produced by ureterligation. Changes in serum erythropoietin levels and the in vitro P/sub 50/ appear to be two separate but interrelated physiological events which occur during the adaptation of animals to hypoxic environments.

  18. Suppression of the expression of hypoxia-inducible factor-1α by RNA interference alleviates hypoxia-induced pulmonary hypertension in adult rats.

    Li, Ying; Shi, Bo; Huang, Liping; Wang, Xin; Yu, Xiaona; Guo, Baosheng; Ren, Weidong

    2016-12-01

    Hypoxia-inducible factor-1α (HIF-1α) has been implicated in the pathogenesis of hypoxic pulmonary hypertension (PH). However, the potential clinical value of HIF-1α as a therapeutic target in the treatment of PH has not yet been evaluated. In this study, an animal model of hypoxia-induced PH was established by exposing adult rats to 10% O2 for 3 weeks, and the effects of the lentivirus-mediated delivery of HIF-1α short hairpin RNA (shRNA) by intratracheal instillation prior to exposure to hypoxia on the manifestations of hypoxia-induced PH were assessed. The successful delivery of HIF-1α shRNA into the pulmonary arteries effectively suppressed the hypoxia-induced upregulation of HIF-1α, accompanied by the prominent attenuation the symptoms associated with hypoxia-induced PH, including the elevation of pulmonary arterial pressure, hypertrophy and hyperplasia of pulmonary artery smooth muscle cells (PASMCs), as well as the muscularization of pulmonary arterioles. In addition, the knockdown of HIF-1α in cultured rat primary PASMCs significantly inhibited the hypoxia-induced acceleration of the cell cycle and the proliferation of the PASMCs, suggesting that HIF-1α may be a direct mediator of PASMC hyperplasia in hypoxia-induced PH. In conclusion, this study demonstrates the potent suppressive effects of HIF-1α shRNA on hypoxia-induced PH and PASMC hyperplasia, providing evidence for the potential application of HIF-1α shRNA in the treatment of hypoxic PH.

  19. Hypoxia promotes apoptosis of neuronal cells through hypoxia-inducible factor-1α-microRNA-204-B-cell lymphoma-2 pathway.

    Wang, Xiuwen; Li, Ji; Wu, Dongjin; Bu, Xiangpeng; Qiao, Yong

    2016-01-01

    Neuronal cells are highly sensitive to hypoxia and may be subjected to apoptosis when exposed to hypoxia. Several apoptosis-related genes and miRNAs involve in hypoxia-induced apoptosis. This study aimed to examine the role of HIF1α-miR-204-BCL-2 pathway in hypoxia-induced apoptosis in neuronal cells. Annexin V/propidium iodide assay was performed to analyze cell apoptosis in AGE1.HN and PC12 cells under hypoxic or normoxic conditions. The expression of BCL-2 and miR-204 were determined by Western blot and qRT-PCR. The effects of miR-204 overexpression or knockdown on the expression of BCL-2 were evaluated by luciferase assay and Western blot under hypoxic or normoxic conditions. HIF-1α inhibitor YC-1 and siHIF-1α were employed to determine the effect of HIF-1α on the up-regulation of miR-204 and down-regulation of BCL-2 induced by hypoxia. Apoptosis assay showed the presence of apoptosis induced by hypoxia in neuronal cells. Moreover, we found that hypoxia significantly down-regulated the expression of BCL-2, and increased the mRNA level of miR-204 in neuronal cells than that in control. Bioinformatic analysis and luciferase reporter assay demonstrated that miR-204 directly targeted and regulated the expression of BCL-2. Specifically, the expression of BCL-2 was inhibited by miR-204 mimic and enhanced by miR-204 inhibitor. Furthermore, we detected that hypoxia induced cell apoptosis via HIF-1α/miR-204/BCL-2 in neuronal cells. This study demonstrated that HIF-1α-miR-204-BCL-2 pathway contributed to apoptosis of neuronal cells induced by hypoxia, which could potentially be exploited to prevent spinal cord ischemia-reperfusion injury. © 2015 by the Society for Experimental Biology and Medicine.

  20. Radiation response of tumours

    Twentyman, P.R.

    1988-01-01

    In this chapter knowledge regarding cellular radiation response and the factors which modify it is related to the volume changes and probability of control of irradiated solid tumors. After a discussion of the different cell populations present within solid tumors the cell population kinetics of the neoplastic cells are considered in more detail. The influence of factors related to the three-dimensional geometry of the tumor, particularly hypoxia, are considered, and also the role of the tumor vasculature in radiation response. Repair of sublethal damage (SLD) and potentially lethal damage (PLD) is dealt with and finally the relationship between the various end-points of tumor radioresponsiveness is discussed

  1. Haemorrhagic pituitary tumours

    Lazaro, C.M.; Philippine General Hospital, Manila; Guo, W.Y.; Sami, M.; Hindmarsch, T.; Ericson, K.; Hulting, A.L.; Wersaell, J.

    1994-01-01

    In a group of 69 patients with pituitary tumours, 12 were found to have evidence of intratumoral haemorrhage on MRI, characterized by high signal intensity on short TR/TE sequences. This was verified in all but 1 patient. The majority of the bleedings occurred in macroadenomas. Five (42%) were prolactinomas and 4 (33%) were non-functioning adenomas. There were 2 GH- and 1 ACTH-secreting tumours. All 5 patients with prolactinomas were on bromocriptine medication. Two of the patients had a clinical picture of pituitary apoplexy. The haemorrhage was not large enough to prompt surgery in any of the patients. However, surgical verification of the diagnosis was obtained in 5 cases, while 6 patients were examined with follow-up MRI. (orig.)

  2. Tumours following retinoblastoma radiotherapy

    Mollot, J.-P.

    1978-01-01

    Radioinduced tumours in young patients irradiated in childhood for retinoblastoma take on a particularly deadly aspect. The onset of this true clinical entity characterized by a long post-irradiation latency period induced by a dose above 6000 rads is a real tragedy. The vast majority of patients then enter into a long martyrdom ending in death. The only cure is surgical, but seldom possible. Treatment is limited to palliative radiotherapy, effective for a while, and chemiotherapy as a last resort but often difficult to prescribe. Prevention alone is the answer. The quality and reliability of the radiotherapeutic treatment depend not only on the personal talent of the radiotherapist but above all on the standard of the equipment. A strong reduction in the doses employed as well as recent technological progress improving the material, its precision and reproducibility appear already to have lowered the frequency curve of these fatal radioinduced tumours [fr

  3. Skull base tumours

    Borges, Alexandra [Instituto Portugues de Oncologia Francisco Gentil, Servico de Radiologia, Rua Professor Lima Basto, 1093 Lisboa Codex (Portugal)], E-mail: borgesalexandra@clix.pt

    2008-06-15

    With the advances of cross-sectional imaging radiologists gained an increasing responsibility in the management of patients with skull base pathology. As this anatomic area is hidden to clinical exam, surgeons and radiation oncologists have to rely on imaging studies to plan the most adequate treatment. To fulfil these endeavour radiologists need to be knowledgeable about skull base anatomy, about the main treatment options available, their indications and contra-indications and needs to be aware of the wide gamut of pathologies seen in this anatomic region. This article will provide a radiologists' friendly approach to the central skull base and will review the most common central skull base tumours and tumours intrinsic to the bony skull base.

  4. Skull base tumours

    Borges, Alexandra

    2008-01-01

    With the advances of cross-sectional imaging radiologists gained an increasing responsibility in the management of patients with skull base pathology. As this anatomic area is hidden to clinical exam, surgeons and radiation oncologists have to rely on imaging studies to plan the most adequate treatment. To fulfil these endeavour radiologists need to be knowledgeable about skull base anatomy, about the main treatment options available, their indications and contra-indications and needs to be aware of the wide gamut of pathologies seen in this anatomic region. This article will provide a radiologists' friendly approach to the central skull base and will review the most common central skull base tumours and tumours intrinsic to the bony skull base

  5. Malignant salivary gland tumours

    Thompson, S.H.

    1982-01-01

    The most frequent malignant salivary gland tumours are the mucoepidermoid tumour, adenoid cystic carcinoma and adenocarcinoma. The major salivary glands and the minor glands of the mouth and upper respiratory tract may potentially develop any of these malignant lesions. Malignant lesions most frequently present as a palpable mass and tend to enlarge more rapidly than benign neoplasms. Pain, paresthesia, muscle paralysis and fixation to surrounding tissue are all ominous signs and symptoms. The only reliable means of differential diagnosis of these lesions is biopsy and histologic analysis. Therapy involves surgery or a combination of surgery and radiation therapy. The ultimate prognosis is governed by the intrinsic biologic behaviour of the neoplasms, the extent of disease and adequate clinical therapy

  6. Malignant salivary gland tumours

    Thompson, S.H. (University of the Witwatersrand, Johannesburg (South Africa). Dept. of Oral Pathology)

    1982-08-01

    The most frequent malignant salivary gland tumours are the mucoepidermoid tumour, adenoid cystic carcinoma and adenocarcinoma. The major salivary glands and the minor glands of the mouth and upper respiratory tract may potentially develop any of these malignant lesions. Malignant lesions most frequently present as a palpable mass and tend to enlarge more rapidly than benign neoplasms. Pain, paresthesia, muscle paralysis and fixation to surrounding tissue are all ominous signs and symptoms. The only reliable means of differential diagnosis of these lesions is biopsy and histologic analysis. Therapy involves surgery or a combination of surgery and radiation therapy. The ultimate prognosis is governed by the intrinsic biologic behaviour of the neoplasms, the extent of disease and adequate clinical therapy.

  7. Nitroimidazoles and imaging hypoxia

    Nunn, A.; Linder, K.; Strauss, H.W.

    1995-01-01

    A class of compounds known to undergo different intracellular metabolism depending on the availability of oxygen in tissue, the nitroimidazoles, have been advocated for imaging hypoxic tissue. In the presence of normal oxygen levels the molecule is immediately reoxidized. In hypoxic tissue the low oxygen concentration is not able to effectively compete to reoxidize the molecule and further reduction appears to take place. The association is not irreversible. Nitroimidazoles for in vivo imaging using radiohalogenated derivatives of misonidazole have recently been employed in patients. Two major problems with fluoromisonidazole are its relatively low concentration within the lesion and the need to wait several hours to permit clearance of the agent from the normoxic background tissue. Even with high-resolution positron emission tomographic imaging, this combination of circumstances makes successful evaluation of hypoxic lesions a challenge. Single-photon agents, with their longer half-lives and comparable biological properties, offer a greater opportunity for successful imaging. In 1992 technetium-99m labeled nitroimidazoles were described that seem to have at least comparable in vivo characteristics. Laboratory studies have demonstrated preferential binding of these agents to hypoxic tissue in the myocardium, in the brain, and in tumors. These investigations indicate that imaging can provide direct evidence of tissue with low oxygen levels that is viable. Even from this early vantage point the utility of measuring tissue oxygen levels with external imaging suggests that hypoxia imaging could play a major role in clinical decision making. (orig./MG)

  8. Chronic hypoxia promotes pulmonary artery endothelial cell proliferation through H2O2-induced 5-lipoxygenase.

    Kristi M Porter

    Full Text Available Pulmonary Hypertension (PH is a progressive disorder characterized by endothelial dysfunction and proliferation. Hypoxia induces PH by increasing vascular remodeling. A potential mediator in hypoxia-induced PH development is arachidonate 5-Lipoxygenase (ALOX5. While ALOX5 metabolites have been shown to promote pulmonary vasoconstriction and endothelial cell proliferation, the contribution of ALOX5 to hypoxia-induced proliferation remains unknown. We hypothesize that hypoxia exposure stimulates HPAEC proliferation by increasing ALOX5 expression and activity. To test this, human pulmonary artery endothelial cells (HPAEC were cultured under normoxic (21% O2 or hypoxic (1% O2 conditions for 24-, 48-, or 72 hours. In a subset of cells, the ALOX5 inhibitor, zileuton, or the 5-lipoxygenase activating protein inhibitor, MK-886, was administered during hypoxia exposure. ALOX5 expression was measured by qRT-PCR and western blot and HPAEC proliferation was assessed. Our results demonstrate that 24 and 48 hours of hypoxia exposure have no effect on HPAEC proliferation or ALOX5 expression. Seventy two hours of hypoxia significantly increases HPAEC ALOX5 expression, hydrogen peroxide (H2O2 release, and HPAEC proliferation. We also demonstrate that targeted ALOX5 gene silencing or inhibition of the ALOX5 pathway by pharmacological blockade attenuates hypoxia-induced HPAEC proliferation. Furthermore, our findings indicate that hypoxia-induced increases in cell proliferation and ALOX5 expression are dependent on H2O2 production, as administration of the antioxidant PEG-catalase blocks these effects and addition of H2O2 to HPAEC promotes proliferation. Overall, these studies indicate that hypoxia exposure induces HPAEC proliferation by activating the ALOX5 pathway via the generation of H2O2.

  9. Imaging brain tumour microstructure.

    Nilsson, Markus; Englund, Elisabet; Szczepankiewicz, Filip; van Westen, Danielle; Sundgren, Pia C

    2018-05-08

    Imaging is an indispensable tool for brain tumour diagnosis, surgical planning, and follow-up. Definite diagnosis, however, often demands histopathological analysis of microscopic features of tissue samples, which have to be obtained by invasive means. A non-invasive alternative may be to probe corresponding microscopic tissue characteristics by MRI, or so called 'microstructure imaging'. The promise of microstructure imaging is one of 'virtual biopsy' with the goal to offset the need for invasive procedures in favour of imaging that can guide pre-surgical planning and can be repeated longitudinally to monitor and predict treatment response. The exploration of such methods is motivated by the striking link between parameters from MRI and tumour histology, for example the correlation between the apparent diffusion coefficient and cellularity. Recent microstructure imaging techniques probe even more subtle and specific features, providing parameters associated to cell shape, size, permeability, and volume distributions. However, the range of scenarios in which these techniques provide reliable imaging biomarkers that can be used to test medical hypotheses or support clinical decisions is yet unknown. Accurate microstructure imaging may moreover require acquisitions that go beyond conventional data acquisition strategies. This review covers a wide range of candidate microstructure imaging methods based on diffusion MRI and relaxometry, and explores advantages, challenges, and potential pitfalls in brain tumour microstructure imaging. Copyright © 2018. Published by Elsevier Inc.

  10. [Adrenal tumours in childhood].

    Martos-Moreno, G A; Pozo-Román, J; Argente, J

    2013-09-01

    This special article aims to summarise the current knowledge regarding the two groups of tumours with their origin in the adrenal gland: 1) adrenocortical tumours, derived from the cortex of the adrenal gland and 2) phaeochromocytomas and paragangliomas, neuroendocrine tumours derived from nodes of neural crest derived cells symmetrically distributed at both sides of the entire spine (paragangliomas [PG]). These PGs can be functioning tumors that secrete catecholamines, which confers their typical dark colour after staining with chromium salts (chromaffin tumors). Among these, the term phaeochromocytoma (PC) is restricted to those PGs derived from the chromaffin cells in the adrenal medulla (intra-adrenal PGs), whereas the term PG is used for those sympathetic or parasympathetic ones in an extra-adrenal location. We analyse the state of the art of their pathogenic and genetic bases, as well as their clinical signs and symptoms, the tests currently available for performing their diagnosis (biochemical, hormonal, imaging and molecular studies) and management (surgery, pre- and post-surgical medical treatment), considering the current and developing strategies in chemo- and radiotherapy. Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

  11. Inhibitory effect of magnolol on tumour metastasis in mice.

    Ikeda, Koji; Sakai, Yoshimichi; Nagase, Hisamitsu

    2003-09-01

    It has previously been reported that magnolol, a phenolic compound isolated from Magnolia obovata, inhibited tumour cell invasion in vitro. The purpose of this study was to investigate the antimetastatic effect of magnolol on tumour metastasis in vivo with experimental and spontaneous metastasis models and to clarify the mechanism. The antimetastatic effects of magnolol were evaluated by an experimental liver and spleen metastasis model using L5178Y-ML25 lymphoma, or an experimental and spontaneous lung metastasis model using B16-BL6 melanoma. Intraperitoneal (i.p.) administration of 2 or 10 mg/kg of magnolol significantly suppressed liver and spleen metastasis or lung metastasis. As for the spontaneous lung metastasis model using B16-BL6 melanoma, multiple i.p. administrations of 10 mg/kg of magnolol after and before tumour inoculation significantly suppressed lung metastasis and primary tumour growth. In addition, magnolol significantly inhibited B16-BL6 cell invasion of the reconstituted basement membrane (Matrigel, MG) without affecting cell growth. These data from the in vivo experiments suggest that magnolol possesses strong antimetastatic ability and that it may be a lead compound for drug development. The antimetastatic action of magnolol is considered to be due to its ability to inhibit tumour cell invasion. Copyright 2003 John Wiley & Sons, Ltd.

  12. The potential role of cyclooxygenase-2 inhibitors in the treatment of experimentally-induced mammary tumour: does celecoxib enhance the anti-tumour activity of doxorubicin?

    Awara, Wageh M; El-Sisi, Alaa E; El-Sayad, Magda E; Goda, Ahmed E

    2004-11-01

    The potential anti-tumour activity of non-steroidal anti-inflammatory drugs (NSAIDS) has been previously discussed. This study was undertaken to assess the possible anti-tumour activity of the cyclooxygenase-2 (COX-2) inhibitor; celecoxib in an animal model of mammary carcinoma; the solid Ehrlich carcinoma (SEC). The possibility that celecoxib may modulate the anti-tumour activity of doxorubicin on the SEC was also studied. Some of the possible mechanisms underlying such modulation were investigated. The anti-tumour activity of celecoxib (25 mg kg(-1)), diclofenac (12.5 mg kg(-1)) and doxorubicin (2 mg kg(-1)) either alone or in combination were investigated on SEC in vivo through the assessment of tumour growth delay (TGD) and tumour volume (TV), changes in tumour DNA content and nitric oxide (NO) levels, immunohistochemical staining of the tumour suppressor gene product; p53 histopathological examination and determination of apoptotic index of SEC. In addition, the influence of these drugs on the DNA fragmentation pattern of Ehrlich carcinoma cells (ECC) was studied. It was found that both celecoxib and diclofenac lack the anti-tumour activity on SEC. In addition there was a significant increase in doxorubicin anti-tumour activity when administered in combination with celecoxib. Moreover, it was found that both celecoxib and diclofenac have the potential to inhibit the function of P-glycoprotein (P-gp) in ECC using rhodamine uptake and efflux assays. Therefore, the current study suggested the chemosensitizing potential of celecoxib in the SEC animal model of mammary tumour, which could be explained in part on the basis of inhibition of P-gp function, with possible enhancement of doxorubicin anti-tumour activity.

  13. Variations in tumour oxygen tension (pO2) during accelerated radiotherapy of head and neck carcinoma

    Guichard, M.; Eschwege, F.; Luboinski, B.; Wibault, P.; Weeger, P.; Lusinchi, A.; Lartigau, E.

    1998-01-01

    The study was performed to assess the effect of accelerated radiotherapy on oxygenation of primary tumours and metastatic nodes in patients with advanced head and neck tumours. In 14 patients with head and neck tumour, oxygen tension (pO 2 ) was evaluated in normal tissues and tumours (primary tumour or metastatic neck node) before (0 Gy) and after 2 weeks (32 Gy) of accelerated radiotherapy (70 Gy in 3.5 weeks, with three daily fractions). Radiotherapy was combined with carbogen breathing in 5 patients. pO 2 was measured using a polarographic technique. For pooled normal tissues, median pO 2 was 38 mmHg before treatment and 46 mmHg after 2 weeks. For tumours, very low values ( 2 12 mmHg before treatment versus 26 mmHg after 2 weeks, P 2 was 44 mmHg at 2 weeks, compared with 13.5 mmHg before treatment (P=0.05). Very low pO 2 values, corresponding to tumour hypoxia, were found in the tumours (primary and metastatic neck nodes) prior to accelerated treatment. During the first 2 weeks of accelerated treatment, an increase in median pO 2 was found in nine of the 14 tumours, together with a decrease in the frequency of very low values. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  14. Simulation study of pO2 distribution in induced tumour masses and normal tissues within a microcirculation environment.

    Li, Mao; Li, Yan; Wen, Peng Paul

    2014-01-01

    The biological microenvironment is interrupted when tumour masses are introduced because of the strong competition for oxygen. During the period of avascular growth of tumours, capillaries that existed play a crucial role in supplying oxygen to both tumourous and healthy cells. Due to limitations of oxygen supply from capillaries, healthy cells have to compete for oxygen with tumourous cells. In this study, an improved Krogh's cylinder model which is more realistic than the previously reported assumption that oxygen is homogeneously distributed in a microenvironment, is proposed to describe the process of the oxygen diffusion from a capillary to its surrounding environment. The capillary wall permeability is also taken into account. The simulation study is conducted and the results show that when tumour masses are implanted at the upstream part of a capillary and followed by normal tissues, the whole normal tissues suffer from hypoxia. In contrast, when normal tissues are ahead of tumour masses, their pO2 is sufficient. In both situations, the pO2 in the whole normal tissues drops significantly due to the axial diffusion at the interface of normal tissues and tumourous cells. As the existence of the axial oxygen diffusion cannot supply the whole tumour masses, only these tumourous cells that are near the interface can be partially supplied, and have a small chance to survive.

  15. Gelatinase B/MMP-9 in Tumour Pathogenesis and Progression

    Farina, Antonietta Rosella; Mackay, Andrew Reay, E-mail: andrewreay.mackay@univaq.it [Department of Applied Clinical and Biotechnological Sciences, University of L’Aquila, Via Vetoio, Coppito 2, L’Aquila 67100 (Italy)

    2014-01-27

    Since its original identification as a leukocyte gelatinase/type V collagenase and tumour type IV collagenase, gelatinase B/matrix metalloproteinase (MMP)-9 is now recognised as playing a central role in many aspects of tumour progression. In this review, we relate current concepts concerning the many ways in which gelatinase B/MMP-9 influences tumour biology. Following a brief outline of the gelatinase B/MMP-9 gene and protein, we analyse the role(s) of gelatinase B/MMP-9 in different phases of the tumorigenic process, and compare the importance of gelatinase B/MMP-9 source in the carcinogenic process. What becomes apparent is the importance of inflammatory cell-derived gelatinase B/MMP-9 in tumour promotion, early progression and triggering of the “angiogenic switch”, the integral relationship between inflammatory, stromal and tumour components with respect to gelatinase B/MMP-9 production and activation, and the fundamental role for gelatinase B/MMP-9 in the formation and maintenance of tumour stem cell and metastatic niches. It is also apparent that gelatinase B/MMP-9 plays important tumour suppressing functions, producing endogenous angiogenesis inhibitors, promoting inflammatory anti-tumour activity, and inducing apoptosis. The fundamental roles of gelatinase B/MMP-9 in cancer biology underpins the need for specific therapeutic inhibitors of gelatinase B/MMP-9 function, the use of which must take into account and substitute for tumour-suppressing gelatinase B/MMP-9 activity and also limit inhibition of physiological gelatinase B/MMP-9 function.

  16. Quantitative imaging of pO2 in orthotopic murine gliomas: hypoxia correlates with resistance to radiation.

    Yasui, Hironobu; Kawai, Tatsuya; Matsumoto, Shingo; Saito, Keita; Devasahayam, Nallathamby; Mitchell, James B; Camphausen, Kevin; Inanami, Osamu; Krishna, Murali C

    2017-10-01

    Hypoxia is considered one of the microenvironmental factors associated with the malignant nature of glioblastoma. Thus, evaluating intratumoural distribution of hypoxia would be useful for therapeutic planning as well as assessment of its effectiveness during the therapy. Electron paramagnetic resonance imaging (EPRI) is an imaging technique which can generate quantitative maps of oxygen in vivo using the exogenous paramagnetic compound, triarylmethyl and monitoring its line broadening caused by oxygen. In this study, the feasibility of EPRI for assessment of oxygen distribution in the glioblastoma using orthotopic U87 and U251 xenograft model is examined. Heterogeneous distribution of pO 2 between 0 and 50 mmHg was observed throughout the tumours except for the normal brain tissue. U251 glioblastoma was more likely to exhibit hypoxia than U87 for comparable tumour size (median pO 2 ; 29.7 and 18.2 mmHg, p = .028, in U87 and U251, respectively). The area with pO 2 under 10 mmHg on the EPR oximetry (HF10) showed a good correlation with pimonidazole staining among tumours with evaluated size. In subcutaneous xenograft model, irradiation was relatively less effective for U251 compared with U87. In conclusion, EPRI is a feasible method to evaluate oxygen distribution in the brain tumour.

  17. Physiological determinants of human acute hypoxia tolerance.

    2013-11-01

    AbstractIntroduction. We investigated possible physiological determinants of variability in hypoxia tolerance in subjects given a 5-minute normobaric exposure to 25,000 ft equivalent. Physiological tolerance to hypoxia was defined as the magnitude of...

  18. Imaging tissue hypoxia: clinical and pre-clinical experience with {sup 123}IAZA

    Wiebe, L.I. [University of Alberta, Edmonton (Canada). Noujaim Institute for Pharmaceutical Oncology Research, Faculty of Pharmacy and Pharmaceutical Sciences

    1997-10-01

    The molecular mechanisms that underline the selective binding of iodazomycin arabinoside, IAZA, and related nitromidazoles are reviewed as a basis for interpretation of preclinical and clinical data for hypoxic binding of radioiodinated IAZA. Clinical data are presented for {sup 123}IAZA uptake in a number of pathologies including metastatic tumours, peripheral vascular disease in diabetes, muscle stress and rheumatoid arthritis. The results of studies to determine the influence of tumour type on uptake of {sup 123} I-IAZA in patients with a variety of deep-seated solid tumours will be presented. Correlations of hypoxia-dependent binding with {sup 99m}Tc-HMPAO perfusion images will be reviewed and early correlations of uptake to treatment response in cancer will be presented. Unusual features of {sup 123}I-IAZA biodistribution will also be discussed together with detailed pharmacokinetic and radiation dosimetry data for `2{sup 123}I- IAZA in normal volunteers 27 refs., 1 fig.

  19. Imaging tissue hypoxia: clinical and pre-clinical experience with 123IAZA

    Wiebe, L.I.

    1997-01-01

    The molecular mechanisms that underline the selective binding of iodazomycin arabinoside, IAZA, and related nitromidazoles are reviewed as a basis for interpretation of preclinical and clinical data for hypoxic binding of radioiodinated IAZA. Clinical data are presented for 123 IAZA uptake in a number of pathologies including metastatic tumours, peripheral vascular disease in diabetes, muscle stress and rheumatoid arthritis. The results of studies to determine the influence of tumour type on uptake of 123 I-IAZA in patients with a variety of deep-seated solid tumours will be presented. Correlations of hypoxia-dependent binding with 99m Tc-HMPAO perfusion images will be reviewed and early correlations of uptake to treatment response in cancer will be presented. Unusual features of 123 I-IAZA biodistribution will also be discussed together with detailed pharmacokinetic and radiation dosimetry data for '2 123 I- IAZA in normal volunteers

  20. Diacetoxyscirpenol as a new anticancer agent to target hypoxia-inducible factor 1

    Choi, Yong-Joon; Shin, Hyun-Woo; Chun, Yang-Sook; Leutou, Alain Simplice; Son, Byeng Wha; Park, Jong-Wan

    2016-01-01

    Hypoxia activates hypoxia-inducible factor 1, which promotes the progression of malignancy by stimulating angiogenesis and by augmenting the ability of tumors to survive. Thus, HIF-1 is one of the most compelling targets for treating cancers. The aim of this study was to find a small molecule that inhibits HIF-1 under hypoxia in cancer cells. 7,280 compounds in a chemical library were tested in a cancer cell line expressing luciferase HIF-dependently. Through three rounds of screening, we finally picked up a compound that originates from a marine bacterium parasitizing red alga. The antibiotic potently inhibited HIF-1 expression and its transcriptional activity in cancer cells exposed to hypoxia. Through two-step fractionation, diacetoxyscirpenol was purified and identified as a HIF-inhibiting ingredient. Mechanistically, diacetoxyscirpenol inhibits the synthesis of HIF-1α protein and also interferes with the dimerization of HIF-1α and ARNT. It attenuates HIF-mediated gene expression in cancer cells exposed to hypoxia, and by doing so reduces tumorigenic and angiogenic potentials of cancer cells. More importantly, diacetoxyscirpenol retarded tumor growth in mice, and reduced HIF-1α expression and vascular formation in the tumors. Overall, diacetoxyscirpenol is considered a potential drug deregulating the HIF-1 signaling pathway, and it could be beneficially employed for treating malignant tumors with hypoxic microenvironment. PMID:27613833

  1. Vaginal haemangioendothelioma: an unusual tumour.

    Mohan, H

    2012-02-01

    Vaginal tumours are uncommon and this is a particularly rare case of a vaginal haemangioendothelioma in a 38-year-old woman. Initial presentation consisted of symptoms similar to uterovaginal prolapse with "something coming down". Examination under anaesthesia demonstrated a necrotic anterior vaginal wall tumour. Histology of the lesion revealed a haemangioendothelioma which had some features of haemangiopericytoma. While the natural history of vaginal haemangioendothelioma is uncertain, as a group, they have a propensity for local recurrence. To our knowledge this is the third reported case of a vaginal haemangioendothelioma. Management of this tumour is challenging given the paucity of literature on this tumour. There is a need to add rare tumours to our "knowledge bank" to guide management of these unusual tumours.

  2. Intermittent hypoxia in obese Zucker rats: cardiometabolic and inflammatory effects.

    Briançon-Marjollet, Anne; Monneret, Denis; Henri, Marion; Joyeux-Faure, Marie; Totoson, Perle; Cachot, Sandrine; Faure, Patrice; Godin-Ribuot, Diane

    2016-11-01

    What is the central question of this study? This study addresses the relative impact of obesity and intermittent hypoxia in the pathophysiological process of obstructive sleep apnoea by investigating the metabolic, inflammatory and cardiovascular consequences of intermittent hypoxia in lean and obese Zucker rats. What is the main finding and its importance? We found that obesity and intermittent hypoxia have mainly distinct consequences on the investigated inflammatory and cardiometabolic parameters in Zucker rats. This suggests that, for a given severity of sleep apnea, the association of obesity and obstructive sleep apnoea may not necessarily be deleterious. Obstructive sleep apnoea is associated with obesity with a high prevalence, and both co-morbidities are independent cardiovascular risk factors. Intermittent hypoxia (IH) is thought to be the main factor responsible for the obstructive sleep apnoea-related cardiometabolic alterations. The aim of this study was to assess the respective impact of obesity and IH on the inflammatory and cardiometabolic state in rats. Lean and obese Zucker rats were exposed to normoxia or chronic IH, and we assessed metabolic and inflammatory parameters, such as plasma lipids and glucose, serum leptin and adiponectin, liver cytokines, nuclear factor-κB activity and cardiac endothelin-1 levels. Myocardial infarct size was also evaluated following in vitro ischaemia-reperfusion. Circulating lipids, insulin, homeostasis model assessment of insulin resistance (HOMA-IR), leptin and adiponectin levels were higher in obese versus lean rats. Chronic IH did not have a significant impact on metabolic parameters in lean rats. In obese rats, IH increased glycaemia and HOMA-IR. Liver interleukin-6 and tumour necrosis factor-α levels were elevated in lean rats exposed to IH; obesity prevented the increase in interleukin-6 but not in tumour necrosis factor-α. Finally, IH exposure enhanced myocardial sensitivity to infarction in both lean and

  3. Teleosts in hypoxia : Aspects of anaerobic metabolism

    Van den Thillart, G.; van Waarde, Aren

    1985-01-01

    Moderate hypoxia can be tolerated by many fish species, while only some species survive severe hypoxia or anoxia. Hypoxia usually activates anaerobic glycolysis, which may be temporary when the animals are able to improve their oxygen extraction capacity. Switching over to aerobic metabolism allows

  4. Overexpression of BAG3 Attenuates Hypoxia-Induced Cardiomyocyte Apoptosis by Inducing Autophagy.

    Zhang, Jiankai; He, Zhangyou; Xiao, Wenjian; Na, Qingqing; Wu, Tianxiu; Su, Kaixin; Cui, Xiaojun

    2016-01-01

    Hypoxia is a well-known factor in the promotion of apoptosis, which contributes to the development of numerous cardiac diseases, such as heart failure and myocardial infarction. Inhibiting apoptosis is an important therapeutic strategy for the treatment of related heart diseases caused by ischemia/hypoxic injury. Previous studies have demonstrated that BAG3 plays an important role in cardiomyocyte apoptosis and survival. However, the role of BAG3 in hypoxia-induced cardiomyocyte apoptosis remains to be clarified. Here, we demonstrate that BAG3 is induced by hypoxia stimuli in cultured cardiomyocytes. BAG3 expression level was measured in H9c2 cells treated with hypoxia for 48 h. Cell proliferation and apoptosis were tested using MTT assay and Annexin V FITC-PI staining assay, respectively. The mRNA or protein expression level of BAG3, LC3-I, LC3-II, Atg5, NF-x03BA;B p65 and phosphorylated NF-x03BA;B p65 were assessed by qRT-PCR and western blot assay, respectively. Resluts: Overexpression of BAG3 inhibited cell apoptosis and promoted proliferation in hypoxia-injured H9c2 cells. Furthermore, autophagy and NF-x03BA;B were activated by BAG3 overexpression, and the NF-x03BA;B inhibitor PDTC could inhibit the activation of autophagy induced by BAG3 overexpression. In addition, the autophagy inhibitor 3-MA partly impeded the inhibitory effect of BAG3 on hypoxia-induced cardiomyocyte apoptosis. these results suggested that overexpression of BAG3 promoted cell proliferation and inhibited apoptosis by activating autophagy though the NF-x03BA;B signaling pathway in hypoxia-injured cardiomyocytes. © 2016 The Author(s) Published by S. Karger AG, Basel.

  5. Overexpression of BAG3 Attenuates Hypoxia-Induced Cardiomyocyte Apoptosis by Inducing Autophagy

    Jiankai Zhang

    2016-07-01

    Full Text Available Background: Hypoxia is a well-known factor in the promotion of apoptosis, which contributes to the development of numerous cardiac diseases, such as heart failure and myocardial infarction. Inhibiting apoptosis is an important therapeutic strategy for the treatment of related heart diseases caused by ischemia/hypoxic injury. Previous studies have demonstrated that BAG3 plays an important role in cardiomyocyte apoptosis and survival. However, the role of BAG3 in hypoxia-induced cardiomyocyte apoptosis remains to be clarified. Here, we demonstrate that BAG3 is induced by hypoxia stimuli in cultured cardiomyocytes. Methods: BAG3 expression level was measured in H9c2 cells treated with hypoxia for 48 h. Cell proliferation and apoptosis were tested using MTT assay and Annexin V FITC-PI staining assay, respectively. The mRNA or protein expression level of BAG3, LC3-I, LC3-II, Atg5, NF-κB p65 and phosphorylated NF-κB p65 were assessed by qRT-PCR and western blot assay, respectively. Resluts: Overexpression of BAG3 inhibited cell apoptosis and promoted proliferation in hypoxia-injured H9c2 cells. Furthermore, autophagy and NF-κB were activated by BAG3 overexpression, and the NF-κB inhibitor PDTC could inhibit the activation of autophagy induced by BAG3 overexpression. In addition, the autophagy inhibitor 3-MA partly impeded the inhibitory effect of BAG3 on hypoxia-induced cardiomyocyte apoptosis. Conclusion: these results suggested that overexpression of BAG3 promoted cell proliferation and inhibited apoptosis by activating autophagy though the NF-κB signaling pathway in hypoxia-injured cardiomyocytes.

  6. Primary bone tumours in infants

    Kozlowski, K.; Beluffi, G.; Cohen, D.H.; Padovani, J.; Tamaela, L.; Azouz, M.; Bale, P.; Martin, H.C.; Nayanar, V.V.; Arico, M.

    1985-09-01

    Ten cases of primary bone tumours in infants (1 osteosarcoma, 3 Ewing's sarcoma, 1 chondroblastoma and 5 angiomastosis) are reported. All cases of angiomatosis showed characteristic radiographic findings. In all the other tumours the X-ray appearances were different from those usually seen in older children and adolescents. In the auhtors' opinion the precise diagnosis of malignant bone tumours in infancy is very difficult as no characteristic X-ray features are present in this age period.

  7. Radiological diagnosis of liver tumours

    Lundstedt, C.

    1987-01-01

    Sixty patients treated with an intra-arterial cytostatic drug for metastases from colo-rectal carcinoma were evaluated with angiography to determine prognostic parameters. The extent of tumour in the liver and an unchanged or diminished tumour volume following treatment, as demonstrated with angiography, were associated with significant prolongation of survival. Patients who developed occlusion of the hepatic artery or of branches of the portal vein, also survived longer. 189 patients examined with angiography, 161 with computed tomography (CT), 95 with computed tomographic arteriography (CTA) and 71 with ultrasound (US) were subjected to liver evaluation at laparotomy consisting of inspection and palpation. The result of this surgical liver evaluation was for the purpose of the study regarded as completely accurate and was used to assess the accuracy of the different radiological methods. The location of tumour in the liver lobes or segments was analysed, with a separate evaluation of the right and left liver lobes. The rate of detection of individual tumour nodules was also determined. Angiography detected 55% of liver areas affected by tumour and 47% of individual tumour nodules. CT detected 83% of liver lobes or segments containing tumour, and 70% of the tumour nodules. US detected 69% of the portions of liver holding tumour, and also 69% of the tumour nodules. CTA detected 85% of tumours areas and 74% of separate tumour nodules. Some lesions detected with CT were not seen with CTA and vice versa. More false-positive results were recorded with CTA than with CT using intravenous contrast enhancement. (orig.)

  8. Hypoxia-induced oxidative base modifications in the VEGF hypoxia-response element are associated with transcriptionally active nucleosomes.

    Ruchko, Mykhaylo V; Gorodnya, Olena M; Pastukh, Viktor M; Swiger, Brad M; Middleton, Natavia S; Wilson, Glenn L; Gillespie, Mark N

    2009-02-01

    Reactive oxygen species (ROS) generated in hypoxic pulmonary artery endothelial cells cause transient oxidative base modifications in the hypoxia-response element (HRE) of the VEGF gene that bear a conspicuous relationship to induction of VEGF mRNA expression (K.A. Ziel et al., FASEB J. 19, 387-394, 2005). If such base modifications are indeed linked to transcriptional regulation, then they should be detected in HRE sequences associated with transcriptionally active nucleosomes. Southern blot analysis of the VEGF HRE associated with nucleosome fractions prepared by micrococcal nuclease digestion indicated that hypoxia redistributed some HRE sequences from multinucleosomes to transcriptionally active mono- and dinucleosome fractions. A simple PCR method revealed that VEGF HRE sequences harboring oxidative base modifications were found exclusively in mononucleosomes. Inhibition of hypoxia-induced ROS generation with myxathiozol prevented formation of oxidative base modifications but not the redistribution of HRE sequences into mono- and dinucleosome fractions. The histone deacetylase inhibitor trichostatin A caused retention of HRE sequences in compacted nucleosome fractions and prevented formation of oxidative base modifications. These findings suggest that the hypoxia-induced oxidant stress directed at the VEGF HRE requires the sequence to be repositioned into mononucleosomes and support the prospect that oxidative modifications in this sequence are an important step in transcriptional activation.

  9. Neurohypophysis granular cell tumours. Upon neurohypophysis rare tumours

    Barrande, G.; Kujas, M.; Gancel, A.; Turpin, G.; Bruckert, E.; Kuhn, J.M.; Luton, J.P.

    1995-01-01

    Granular cell tumours of neurohypophysis are rare. These tumours are more often encountered as incidental autopsy findings seen in up to 17 % of unselected adult autopsy cases. There are few reports of para-sellar granular cell tumours large enough to cause symptoms. We present three cases of neurohypophysis granular cell tumour and a review of the literature. In one patient, the asymptomatic granular cell tumour was incidentally discovered at surgical removal of a corticotrophic micro-adenoma. The remaining 2 patients had a symptomatic tumour which caused neurological symptoms such as visual disturbance and headaches and endocrine disorders such as hypopituitarism or hyper-prolactinaemia. In these 2 cases, computerized tomography showed a well-circumscribed, contrast-enhanced, intra-sellar and supra-sellar mass. Magnetic resonance imaging demonstrated an isointense gadolinium-enhanced mass in T1-weighted-images. Trans-sphenoidal partial resection was performed and histology was interpreted as a granular cell tumour. The immunohistochemical study was positive for glial fibrillary acidic protein (GEAP) and neuron specific enolase (NSE) in 1 of the 2 tumours and positive for S100 protein and vimentin in both tumours but negative for CD68. The histogenesis of neurohypophysis granular cell tumours is still controversial but ultrastructural and immunohistochemical studies support the theory that may arise from pituicytes, the glial cells of neurohypophysis. Management of these benign, slow growing, tumours is based mainly on neurosurgical resection. Data from the literature do not support a beneficial effect of post operative radiation therapy on postoperative recurrences. (authors). 23 refs., 4 figs., 1 tab

  10. Management of parapharyngeal space tumours

    Ahmad, F.; Waqar-Uddin; Khan, M.S.; Khawar, A.; Bangush, W.; Aslam, J.

    2006-01-01

    Objective: To determine the role of clinical features, fine needle aspiration cytology (FNAC) and computed tomography (CT) scan in diagnosing Para pharyngeal space (PPS) tumours and treatment options. Design: A descriptive study. Place and Duration of Study: From July 2000 to July 2002 at Pakistan Institute of Medical Sciences, Islamabad. Patients and Methods: Patients diagnosed as having PPS tumours were studied. The medical record of patients was reviewed for their age, gender, clinical features, investigations (FNAC and CT scan) and treatment. The mean age, percentage of different clinical features and the sensitivity and specificity of FNAC was determined. Results: The mean age of patients presenting with PPS tumours was 33.6 years. The most common clinical features were neck mass (93%) and bulge in lateral pharyngeal wall (80%). The CT scan showed exact location and extent of tumour in 11 out of 15 cases. The sensitivity and specificity of FNAC was 70% and 85% respectively. The most common tumours were neurogenic tumours and salivary gland tumours. Surgery was performed in all except 2 patients with lymphoma in whom radiation and chemotherapy was recommended. Conclusion: This study indicates that PPS tumours are usually benign neurosurgeon and salivary gland tumours presenting with neck mass and bulge in or oropharynx. FNAC and CT scan are important in diagnostic work up and treatment planning. Surgery has the best results in most cases. (author)

  11. Askin Tumour: Case Report

    Gomez, Carolina; Ramirez, Sandra Milena; Quesada, Diana Constanza; Unigarro Luz Adriana

    2011-01-01

    In this article we report a case of a 19 year-old woman with a final diagnosis of an extra skeletal Primitive Neuroectodermal Tumor/Ewing sarcoma of the chest, also known as Askin tumour. The histologic features and the immunohistochemical profile were consistent with this aggressive malignancy of the chest wall that affects young people. Because the low incidence of this entity, as well as the clear radiological findings, we considered it interesting to describe this documented case and undertake a review of the literature.

  12. [Protective effect of Uncaria rhynchophylla total alkaloids pretreatment on hippocampal neurons after acute hypoxia].

    Liu, Wei; Zhang, Zhao-qin; Zhao, Xiao-min; Gao, Yun-sheng

    2006-05-01

    To investigate the effect of Uncaria rhynchophylla total alkaloids (RTA) pretreatment on the voltage-gated sodium currents of the rat hippocampal neurons after acute hypoxia. Primary cultured hippocampal neurons were divided into RTA pre-treated and non-pretreated groups. Patch clamp whole-cell recording was used to compare the voltage-gated sodium current amplitude and threshold with those before hypoxia. After acute hypoxia, sodium current amplitude was significantly decreased and its threshold was upside. RTA pretreatment could inhibit the reduction of sodium current amplitude. RTA pretreatment alleviates the acute hypoxia-induced change of sodium currents, which may be one of the mechanisms for protective effect of RTA on cells.

  13. Initial results of hypoxia imaging using 1-{alpha}-d-(5-deoxy-5-[{sup 18}F]-fluoroarabinofuranosyl)-2-nitroimidazole ({sup 18}F-FAZA)

    Postema, Ernst J.; McEwan, Alexander J.B.; Riauka, Terence A.; Kumar, Piyush; Richmond, Dacia A.; Abrams, Douglas N. [University of Alberta, Department of Oncology, Edmonton, Alberta (Canada); Wiebe, Leonard I. [University of Alberta, Faculty of Pharmacy and Pharmaceutical Sciences, Edmonton, Alberta (Canada)

    2009-10-15

    Tumour hypoxia is thought to play a significant role in the outcome of solid tumour therapy. Positron emission tomography (PET) is the best-validated noninvasive technique able to demonstrate the presence of hypoxia in vivo. The locally developed PET tracer for imaging hypoxia, 1-{alpha}-d-(5-deoxy-5-[{sup 18}F]-fluoroarabinofuranosyl)-2-nitroimidazole ({sup 18}F-FAZA), has been shown to accumulate in experimental models of tumour hypoxia and to clear rapidly from the circulation and nonhypoxic tissues. The safety and general biodistribution patterns of this radiopharmaceutical in patients with squamous cell carcinoma of the head and neck (HNSCC), small-cell lung cancer (SCLC) or non-small-cell lung cancer (NSCLC), malignant lymphoma, and high-grade gliomas, were demonstrated in this study. Patients with known primary or suspected metastatic HNSCC, SCLC or NSCLC, malignant lymphoma or high-grade gliomas were dosed with 5.2 MBq/kg of {sup 18}F-FAZA, then scanned 2-3 h after injection using a PET or PET/CT scanner. Images were interpreted by three experienced nuclear medicine physicians. The location and relative uptake scores (graded 0 to 4) of normal and abnormal {sup 18}F-FAZA biodistribution patterns, the calculated tumour-to-background (T/B) ratio, and the maximum standardized uptake value were recorded. Included in the study were 50 patients (32 men, 18 women). All seven patients with high-grade gliomas showed very high uptake of {sup 18}F-FAZA in the primary tumour. In six out of nine patients with HNSCC, clear uptake of {sup 18}F-FAZA was observed in the primary tumour and/or the lymph nodes in the neck. Of the 21 lymphoma patients (15 with non-Hodgkin's lymphoma and 6 with Hodgkin's disease), 3 demonstrated moderate lymphoma-related uptake. Of the 13 lung cancer patients (12 NSCLC, 1 SCLC), 7 had increased {sup 18}F-FAZA uptake in the primary lung tumour. No side effects of the administration of {sup 18}F-FAZA were observed. This study suggests

  14. Initial results of hypoxia imaging using 1-α-d-(5-deoxy-5-[18F]-fluoroarabinofuranosyl)-2-nitroimidazole (18F-FAZA)

    Postema, Ernst J.; McEwan, Alexander J.B.; Riauka, Terence A.; Kumar, Piyush; Richmond, Dacia A.; Abrams, Douglas N.; Wiebe, Leonard I.

    2009-01-01

    Tumour hypoxia is thought to play a significant role in the outcome of solid tumour therapy. Positron emission tomography (PET) is the best-validated noninvasive technique able to demonstrate the presence of hypoxia in vivo. The locally developed PET tracer for imaging hypoxia, 1-α-d-(5-deoxy-5-[ 18 F]-fluoroarabinofuranosyl)-2-nitroimidazole ( 18 F-FAZA), has been shown to accumulate in experimental models of tumour hypoxia and to clear rapidly from the circulation and nonhypoxic tissues. The safety and general biodistribution patterns of this radiopharmaceutical in patients with squamous cell carcinoma of the head and neck (HNSCC), small-cell lung cancer (SCLC) or non-small-cell lung cancer (NSCLC), malignant lymphoma, and high-grade gliomas, were demonstrated in this study. Patients with known primary or suspected metastatic HNSCC, SCLC or NSCLC, malignant lymphoma or high-grade gliomas were dosed with 5.2 MBq/kg of 18 F-FAZA, then scanned 2-3 h after injection using a PET or PET/CT scanner. Images were interpreted by three experienced nuclear medicine physicians. The location and relative uptake scores (graded 0 to 4) of normal and abnormal 18 F-FAZA biodistribution patterns, the calculated tumour-to-background (T/B) ratio, and the maximum standardized uptake value were recorded. Included in the study were 50 patients (32 men, 18 women). All seven patients with high-grade gliomas showed very high uptake of 18 F-FAZA in the primary tumour. In six out of nine patients with HNSCC, clear uptake of 18 F-FAZA was observed in the primary tumour and/or the lymph nodes in the neck. Of the 21 lymphoma patients (15 with non-Hodgkin's lymphoma and 6 with Hodgkin's disease), 3 demonstrated moderate lymphoma-related uptake. Of the 13 lung cancer patients (12 NSCLC, 1 SCLC), 7 had increased 18 F-FAZA uptake in the primary lung tumour. No side effects of the administration of 18 F-FAZA were observed. This study suggests that 18 F-FAZA may be a very useful radiopharmaceutical

  15. Snail/beta-catenin signaling protects breast cancer cells from hypoxia attack

    Scherbakov, Alexander M., E-mail: alex.scherbakov@gmail.com [Laboratory of Clinical Biochemistry, Institute of Clinical Oncology, N.N. Blokhin Cancer Research Centre, Kashirskoye sh. 24, Moscow 115478 (Russian Federation); Stefanova, Lidia B.; Sorokin, Danila V.; Semina, Svetlana E. [Laboratory of Molecular Endocrinology, Institute of Carcinogenesis, N.N. Blokhin Cancer Research Centre, Kashirskoye sh. 24, Moscow 115478 (Russian Federation); Berstein, Lev M. [Laboratory of Oncoendocrinology, N.N. Petrov Research Institute of Oncology, St. Petersburg 197758 (Russian Federation); Krasil’nikov, Mikhail A. [Laboratory of Molecular Endocrinology, Institute of Carcinogenesis, N.N. Blokhin Cancer Research Centre, Kashirskoye sh. 24, Moscow 115478 (Russian Federation)

    2013-12-10

    The tolerance of cancer cells to hypoxia depends on the combination of different factors – from increase of glycolysis (Warburg Effect) to activation of intracellular growth/apoptotic pathways. Less is known about the influence of epithelial–mesenchymal transition (EMT) and EMT-associated pathways on the cell sensitivity to hypoxia. The aim of this study was to explore the role of Snail signaling, one of the key EMT pathways, in the mediating of hypoxia response and regulation of cell sensitivity to hypoxia, using as a model in vitro cultured breast cancer cells. Earlier we have shown that estrogen-independent HBL-100 breast cancer cells differ from estrogen-dependent MCF-7 cells with increased expression of Snail1, and demonstrated Snail1 involvement into formation of hormone-resistant phenotype. Because Snail1 belongs to hypoxia-activated proteins, here we studied the influence of Snail1 signaling on the cell tolerance to hypoxia. We found that Snail1-enriched HBL-100 cells were less sensitive to hypoxia-induced growth suppression if compared with MCF-7 line (31% MCF-7 vs. 71% HBL-100 cell viability after 1% O{sub 2} atmosphere for 3 days). Snail1 knock-down enhanced the hypoxia-induced inhibition of cell proliferation giving the direct evidence of Snail1 involvement into cell protection from hypoxia attack. The protective effect of Snail1 was shown to be mediated, at least in a part, via beta-catenin which positively regulated expression of HIF-1-dependent genes. Finally, we found that cell tolerance to hypoxia was accompanied with the failure in the phosphorylation of AMPK – the key energy sensor, and demonstrated an inverse relationship between AMPK and Snail/beta-catenin signaling. Totally, our data show that Snail1 and beta-catenin, besides association with loss of hormone dependence, protect cancer cells from hypoxia and may serve as an important target in the treatment of breast cancer. Moreover, we suggest that the level of these proteins as well

  16. The inhibitory effect of Binens bipinnata L . extract on U14 tumour in ...

    Its inhibition rate was 70.44% at a concentration of 80ìg/L. Solid tumour inhibition rates in the high- and low-dose groups and cisplatin group were 49.13%, 2.26% and 75.72% respectively; life prolongation rates in each ascites tumour group were 63.63%, 34.86% and 87.34% respectively. The Bidens bipinnata L. extract ...

  17. Increasing the radiosensitivity of tumours in an hypoxic environment using inhibitors of the pentose phosphate pathway

    Sahasrabudhe, M.B.; Bhonsle, S.R.; Krishnamurti, K.; Tilak, B.D.

    1977-01-01

    Rapidly growing tumours contain few blood vessels in the tumour mass. Cells in such tumours obtain nutrients and oxygen from the periphery by diffusion, resulting in a diminishing oxygen and nutrient gradient from the periphery to centre of the tumour mass. In normal tissues, oxygen is utilized via a tricarboxylic acid (TCA) cycle; in tumour cells oxygen is utilized via a hexose monophosphate (HMP) pathway and through the TCA cycle at a 30% reduced level. Interference with the HMP pathway selectively inhibits the utilization of oxygen by tumour cells, thus increasing the availability of oxygen to hypoxic cells situated deeper in the tumour mass. This effect has been exploited for increasing the radiosensitivity of tumour cells situated in an hypoxic environment. The influence of sixteen potential antimetabolites on the HMP pathway has been studied. Of these, six compounds, namely, (1) 2-carboxy 5-hydroxymethyl thiophene, (2) the sodium salt of 2:5 dicarbethoxy 3:4 dihydroxy thiophene, (3) the dihydrazide of 2:5 dicarboxy thiophene, (4) the dihydrazide of 3:4 dimethoxy 2:5 dicarboxy thiophene, (5) trithiocyanuric acid, and (6) cyanuric trithioglycollic acid showed an inhibiting effect on the HMP pathway without any influence on the TCA cycle. Influence of administration of compounds (1), (2) and (4) prior to radiation on the growth of transplanted fibrosarcomas in mice has been studied and is reported here. These three compounds showed marked potentiation of radiosensitivity of tumours. (author)

  18. The TrkAIII oncoprotein inhibits mitochondrial free radical ROS-induced death of SH-SY5Y neuroblastoma cells by augmenting SOD2 expression and activity at the mitochondria, within the context of a tumour stem cell-like phenotype.

    Pierdomenico Ruggeri

    Full Text Available The developmental and stress-regulated alternative TrkAIII splice variant of the NGF receptor TrkA is expressed by advanced stage human neuroblastomas (NBs, correlates with worse outcome in high TrkA expressing unfavourable tumours and exhibits oncogenic activity in NB models. In the present study, we report that constitutive TrkAIII expression in human SH-SY5Y NB cells inhibits Rotenone, Paraquat and LY83583-induced mitochondrial free radical reactive oxygen species (ROS-mediated death by stimulating SOD2 expression, increasing mitochondrial SOD2 activity and attenuating mitochondrial free radical ROS production, in association with increased mitochondrial capacity to produce H2O2, within the context of a more tumour stem cell-like phenotype. This effect can be reversed by the specific TrkA tyrosine kinase inhibitor GW441756, by the multi-kinase TrkA inhibitors K252a, CEP-701 and Gö6976, which inhibit SOD2 expression, and by siRNA knockdown of SOD2 expression, which restores the sensitivity of TrkAIII expressing SH-SY5Y cells to Rotenone, Paraquat and LY83583-induced mitochondrial free radical ROS production and ROS-mediated death. The data implicate the novel TrkAIII/SOD2 axis in promoting NB resistance to mitochondrial free radical-mediated death and staminality, and suggest that the combined use of TrkAIII and/or SOD2 inhibitors together with agents that induce mitochondrial free radical ROS-mediated death could provide a therapeutic advantage that may also target the stem cell niche in high TrkA expressing unfavourable NB.

  19. In vitro downregulated hypoxia transcriptome is associated with poor prognosis in breast cancer.

    Abu-Jamous, Basel; Buffa, Francesca M; Harris, Adrian L; Nandi, Asoke K

    2017-06-15

    Hypoxia is a characteristic of breast tumours indicating poor prognosis. Based on the assumption that those genes which are up-regulated under hypoxia in cell-lines are expected to be predictors of poor prognosis in clinical data, many signatures of poor prognosis were identified. However, it was observed that cell line data do not always concur with clinical data, and therefore conclusions from cell line analysis should be considered with caution. As many transcriptomic cell-line datasets from hypoxia related contexts are available, integrative approaches which investigate these datasets collectively, while not ignoring clinical data, are required. We analyse sixteen heterogeneous breast cancer cell-line transcriptomic datasets in hypoxia-related conditions collectively by employing the unique capabilities of the method, UNCLES, which integrates clustering results from multiple datasets and can address questions that cannot be answered by existing methods. This has been demonstrated by comparison with the state-of-the-art iCluster method. From this collection of genome-wide datasets include 15,588 genes, UNCLES identified a relatively high number of genes (>1000 overall) which are consistently co-regulated over all of the datasets, and some of which are still poorly understood and represent new potential HIF targets, such as RSBN1 and KIAA0195. Two main, anti-correlated, clusters were identified; the first is enriched with MYC targets participating in growth and proliferation, while the other is enriched with HIF targets directly participating in the hypoxia response. Surprisingly, in six clinical datasets, some sub-clusters of growth genes are found consistently positively correlated with hypoxia response genes, unlike the observation in cell lines. Moreover, the ability to predict bad prognosis by a combined signature of one sub-cluster of growth genes and one sub-cluster of hypoxia-induced genes appears to be comparable and perhaps greater than that of known

  20. Gastric neuroendocrine tumours.

    Crosby, David A; Donohoe, Claire L; Fitzgerald, Louise; Muldoon, Cian; Hayes, Brian; O'Toole, Dermot; Reynolds, John V

    2012-01-01

    Gastric neuroendocrine tumours (NETs) are increasingly recognised, and management decisions may be difficult due to an incomplete understanding of aetiology, natural history and optimum therapy. This article presents a current understanding based on recent advances in epidemiology, classification, molecular profiling, and treatment. Relevant medical literature was identified from searches of PubMed and references cited in appropriate articles identified. Selection of articles was based on peer review, journal and relevance. Gastric NETs may be divided into three clinical prognostic groups: type I is associated with autoimmune atrophic gastritis and hypergastrinaemia, type II is associated with Zollinger-Ellison syndrome, and type III lesions are gastrin-independent, have the greatest metastatic potential and poorest prognosis. There has been an increased frequency of gastric NETs reported. Management approaches have evolved in parallel with advances in endoscopic staging and surgery, as well as improved understanding of the biology and natural history of NETs. Gastric NETs present a spectrum of activity from indolent tumours to metastatic malignancy. Treatment decisions for patients must be individualised and are best managed by a multidisciplinary team approach. The current evidence base is limited to small series and efforts to treat patients within clinical networks of expertise are warranted. Copyright © 2012 S. Karger AG, Basel.

  1. Radiotherapy in ocular tumours

    Pinto, J.M.

    1982-01-01

    Ocular tumours at the Tata Memorial Hospital, Bombay, form about 0.14% of all the proved cancer cases. In case of unilateral retinoblastoma with the other eye being not non-seeing for any reason, enucleation is advised, as the diagnosis may sometimes be in doubt. If after enucleation, optic nerve and/or peribulbar tissues are found to be involved, post-operative irradiation is given to the whole orbit. In bilateral retinoblastoma the more affected eye is enucleated and an attempt is made to preserve vision in the other eye. A tumour dose of 3500 to 4000 rad in about 4 weeks is given with a cobalt beam using a direct anterior field. A cataract that may develop has to be taken care of. Lateral and/or medial fields are used with deep X-rays. In certain cases, an implant of cobalt-60 or gold-198 grain is done. For carcinoma of conjuctiva, small lesions or early lesions are excised and a beta radiation dose of 2000 rad weekly for about 4 to 5 weeks is given; larger lesions require enucleation or exenteration followed by irradiation with super-voltage radiation. Post-irradiation sarcomas may develop many years later. Irradiation is repeated for recurrences. (M.G.B.)

  2. Antioxidant responses of triangle sail mussel Hyriopsis cumingii exposed to harmful algae Microcystis aeruginosa and hypoxia.

    Hu, Menghong; Wu, Fangli; Yuan, Mingzhe; Li, Qiongzhen; Gu, Yedan; Wang, Youji; Liu, Qigen

    2015-11-01

    Bloom forming algae and hypoxia are considered to be two main co-occurred stressors associated with eutrophication. The aim of this study was to evaluate the interactive effects of harmful algae Microcystis aeruginosa and hypoxia on an ecologically important mussel species inhabiting lakes and reservoirs, the triangle sail mussel Hyriopsis cumingii, which is generally considered as a bio-management tool for eutrophication. A set of antioxidant enzymes involved in immune defence mechanisms and detoxification processes, i.e. glutathione-S-transferases (GST), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), lysozyme (LZM) in mussel haemolymph were analyzed during 14days exposure along with 7days depuration duration period. GST, GSH, SOD, GPX and LZM were elevated by toxic M. aeruginosa exposure, while CAT activities were inhibited by such exposure. Hypoxia influenced the immune mechanisms through the activation of GSH and GPX, and the inhibition of SOD, CAT, and LZM activities. Meanwhile, some interactive effects of M. aeruginosa, hypoxia and time were observed. Independently of the presence or absence of hypoxia, toxic algal exposure generally increased the five tested enzyme activities of haemolymph, except CAT. Although half of microcystin could be eliminated after 7days depuration, toxic M. aeruginosa or hypoxia exposure history showed some latent effects on most parameters. These results revealed that toxic algae play an important role on haemolymph parameters alterations and its toxic effects could be affected by hypoxia. Although the microcystin depuration rate of H. cumingii is quick, toxic M. aeruginosa and/or hypoxia exposure history influenced its immunological mechanism recovery. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Lack of bcr and abr promotes hypoxia-induced pulmonary hypertension in mice.

    Min Yu

    Full Text Available Bcr and Abr are GTPase activating proteins that specifically downregulate activity of the small GTPase Rac in restricted cell types in vivo. Rac1 is expressed in smooth muscle cells, a critical cell type involved in the pathogenesis of pulmonary hypertension. The molecular mechanisms that underlie hypoxia-associated pulmonary hypertension are not well-defined.Bcr and abr null mutant mice were compared to wild type controls for the development of pulmonary hypertension after exposure to hypoxia. Also, pulmonary arterial smooth muscle cells from those mice were cultured in hypoxia and examined for proliferation, p38 activation and IL-6 production. Mice lacking Bcr or Abr exposed to hypoxia developed increased right ventricular pressure, hypertrophy and pulmonary vascular remodeling. Perivascular leukocyte infiltration in the lungs was increased, and under hypoxia bcr-/- and abr-/- macrophages generated more reactive oxygen species. Consistent with a contribution of inflammation and oxidative stress in pulmonary hypertension-associated vascular damage, Bcr and Abr-deficient animals showed elevated endothelial leakage after hypoxia exposure. Hypoxia-treated pulmonary arterial smooth muscle cells from Bcr- or Abr-deficient mice also proliferated faster than those of wild type mice. Moreover, activated Rac1, phosphorylated p38 and interleukin 6 were increased in these cells in the absence of Bcr or Abr. Inhibition of Rac1 activation with Z62954982, a novel Rac inhibitor, decreased proliferation, p38 phosphorylation and IL-6 levels in pulmonary arterial smooth muscle cells exposed to hypoxia.Bcr and Abr play a critical role in down-regulating hypoxia-induced pulmonary hypertension by deactivating Rac1 and, through this, reducing both oxidative stress generated by leukocytes as well as p38 phosphorylation, IL-6 production and proliferation of pulmonary arterial smooth muscle cells.

  4. Hypoxia-inducible factor-1α induces multidrug resistance protein in colon cancer

    Lv Y

    2015-07-01

    Full Text Available Yingqian Lv, Shan Zhao, Jinzhu Han, Likang Zheng, Zixin Yang, Li Zhao Department of Oncology, The Second Hospital, Hebei Medical University, Shijiazhuang, Hebei Province, People’s Republic of China Abstract: Multidrug resistance is the major cause of chemotherapy failure in many solid tumors, including colon cancer. Hypoxic environment is a feature for all solid tumors and is important for the development of tumor resistance to chemotherapy. Hypoxia-inducible factor (HIF-1α is the key transcription factor that mediates cellular response to hypoxia. HIF-1α has been shown to play an important role in tumor resistance; however, the mechanism is still not fully understood. Here, we found that HIF-1α and the drug resistance-associated gene multidrug resistance associated protein 1 (MRP1 were induced by treatment of colon cancer cells with the hypoxia-mimetic agent cobalt chloride. Inhibition of HIF-1α by RNA interference and dominant-negative protein can significantly reduce the induction of MRP1 by hypoxia. Bioinformatics analysis showed that a hypoxia response element is located at -378 to -373 bp upstream of the transcription start site of MRP1 gene. Luciferase reporter assay combined with mutation analysis confirmed that this element is essential for hypoxia-mediated activation of MRP gene. Furthermore, RNA interference revealed that HIF-1α is necessary for this hypoxia-driven activation of MRP1 promoter. Importantly, chromatin immunoprecipitation analysis demonstrated that HIF-1α could directly bind to this HRE site in vivo. Together, these data suggest that MRP1 is a downstream target gene of HIF-1α, which provides a potential novel mechanism for HIF-1α-mediated drug resistance in colon cancer and maybe other solid tumors as well. Keywords: hypoxia, hypoxia-inducible factor-1α, multidrug resistance associated protein, transcriptional regulation, chemotherapy tolerance

  5. Hypoxia and metastasis in an orthotopic cervix cancer xenograft model

    Chaudary, Naz; Mujcic, Hilda; Wouters, Bradly G.; Hill, Richard P.

    2013-01-01

    Background: Hypoxia can promote tumor metastasis by mechanisms that are believed to result from changes in gene expression. The current study examined the role of putative metastatic genes regulated by cyclic hypoxia in relation to metastasis formation in orthotopic models of cervix cancer. Methods: Orthotopic tumors derived from ME180 human cervix cancer cells or from early generation human cervix cancer xenografts were exposed to cyclic hypoxic conditions during growth in vivo and tumor growth and lymphnode metastases were monitored. Expression of the chemokine receptor CXCR4 and various genes in the Hedgehog (Hh) pathway were inhibited using genetic (inducible shRNA vs CXCR4) small molecule (AMD3100) or antibody (5E1) treatment (CXCR4 and Hh genes, respectively) during tumor growth. Results: As reported previously, exposure of tumor bearing mice to cyclic hypoxia caused a reduction of tumor growth but a large increase in metastasis. Inhibition of CXCR4 or Hh gene activity during tumor growth further reduced primary tumor size and reduced lymphatic metastasis to levels below those seen in control mice exposed to normoxic conditions. Conclusion: Blocking CXCR4 or Hh gene expression are potential therapeutic pathways for improving cervix cancer treatment

  6. Multi-tracer small animal PET imaging of the tumour response to the novel pan-Erb-B inhibitor CI-1033

    Dorow, Donna S.; Cullinane, Carleen; Conus, Nelly; Roselt, Peter; Binns, David; McCarthy, Timothy J.; McArthur, Grant A.; Hicks, Rodney J.

    2006-01-01

    This study was designed as ''proof of concept'' for a drug development model utilising multi-tracer serial small animal PET imaging to characterise tumour responses to molecularly targeted therapy. Mice bearing subcutaneous A431 human squamous carcinoma xenografts (n=6-8) were treated with the pan-Erb-B inhibitor CI-1033 or vehicle and imaged serially (days 0, 3 and 6 or 7) with [ 18 F]fluorodeoxyglucose, [ 18 F]fluoro-L-thymidine, [ 18 F]fluoro-azoazomycinarabinoside or [ 18 F]fluoromisonidazole. Separate cohorts (n=3) were treated identically and tumours were assessed ex vivo for markers of glucose metabolism, proliferation and hypoxia. During the study period, mean uptake of all PET tracers generally increased for control tumours compared to baseline. In contrast, tracer uptake into CI-1033-treated tumours decreased by 20-60% during treatment. Expression of the glucose transporter Glut-1 and cell cycle markers was unchanged or increased in control tumours and generally decreased with CI-1033 treatment, compared to baseline. Thymidine kinase activity was reduced in all tumours compared to baseline at day 3 but was sevenfold higher in control versus CI-1033-treated tumours by day 6 of treatment. Uptake of the hypoxia marker pimonidazole was stable in control tumours but was severely reduced following 7 days of CI-1033 treatment. CI-1033 treatment significantly affects tumour metabolism, proliferation and hypoxia as determined by PET. The PET findings correlated well with ex vivo biomarkers for each of the cellular processes studied. These results confirm the utility of small animal PET for evaluation of the effectiveness of molecularly targeted therapies and simultaneously definition of specific cellular processes involved in the therapeutic response. (orig.)

  7. The prognostic value of pimonidazole and tumour pO2 in human cervix carcinomas after radiation therapy: A prospective international multi-center study

    Nordsmark, Marianne; Loncaster, Julie; Aquino-Parsons, Christina; Chou, S.-C.; Gebski, Val; West, Catharine; Lindegaard, Jacob C.; Havsteen, Hanne; Davidson, Susan E.; Hunter, Robin; Raleigh, James A.; Overgaard, Jens

    2006-01-01

    Background and purpose: Hypoxia adversely affects treatment outcome in human uterine cervical cancer. Here, we present the results of a prospective international multi-centre study evaluating the prognostic value of pre-treatment tumour oxygen partial pressure (pO 2 ) and the hypoxia marker pimonidazole (pimo). Materials and methods: One hundred and twenty-seven patients with primary cervix cancer were entered. Pre-treatment tumour pO 2 measurements were obtained, and reported by the median tumour pO 2 , the fraction of pO 2 values ≤10 mmHg (HP 1 ), ≤5 mmHg (HP 5 ) and ≤2.5 mmHg (HP 2.5 ). Following intravenous pimonidazole administration, biopsies were taken, stained for pimonidazole adducts, and scored for the area of labelled tumour cells on a scale from 0 to 4. Treatment modalities were surgery (11%), radiotherapy (98%), chemotherapy (33%) and carbogen (14%). Results: None of the hypoxia descriptors were statistically significant prognostic factors for loco-regional tumour control or overall survival when analyzed as continuous variables or divided by the sample median. By univariate analysis only tumour size and nodal status were significant prognostic factors for local control. Tumour size and FIGO stage were significant for overall survival. In a multivariate analysis stratified by centre, only tumour size above 5 cm and lower pre-treatment haemoglobin predicted poorer overall survival among FIGO stage, nodal involvement, tumour size, pre-treatment haemoglobin dichotomized at 12 g/dl and pimo 1, pimo 4 and HP 5 as continuous variables. Conclusion: Neither Eppendorf nor pimonidazole should be dismissed based on the current results. However, further investigations are needed to readdress the hypotheses of the current study having optimized statistical designs, and a population of sufficient size treated more homogenously following rigorous protocols

  8. Plasma volume in acute hypoxia

    Poulsen, T D; Klausen, T; Richalet, J P

    1998-01-01

    Exposure to acute hypoxia is associated with changes in body fluid homeostasis and plasma volume (PV). This study compared a dye dilution technique using Evans' blue (PV[Evans']) with a carbon monoxide (CO) rebreathing method (PV[CO]) for measurements of PV in ten normal subjects at sea level...

  9. Preeclampsia, Hypoxia, Thrombosis, and Inflammation

    Amir A. Shamshirsaz

    2012-01-01

    Full Text Available Reductions in uteroplacental flow initiate a cascade of molecular effects leading to hypoxia, thrombosis, inflammation, and endothelial cell dysfunction resulting in untoward pregnancy outcomes. In this review, we detail these effects and their relationship to preeclampsia (PE and intrauterine growth restriction (IUGR.

  10. Hepcidin: A Critical Regulator Of Iron Metabolism During Hypoxia

    2011-01-01

    inducible factor (HIF)/hypoxia response element ( HRE ) system, as well as recent evidence indicating that localized adipose hypoxia due to obesity may...mechanisms by which hypoxia affects hepcidin expression, to include a review of the hypoxia inducible factor (HIF)/hypoxia response element ( HRE ) system, as...a battery of genes are induced by the hypoxia inducible factor (HIF)/hypoxia response element ( HRE ) system. The HIF system senses O2 levels through

  11. Application of magnetic resonance techniques for imaging tumour physiology

    Stubbs, M.

    1999-01-01

    Magnetic resonance (MR) techniques have the unique ability to measure in vivo the biochemical content of living tissue in the body in a dynamic, non-invasive and non-destructive manner. MR also permits serial investigations of steady-state tumour physiology and biochemistry, as well as the response of a tumour to treatment. Magnetic resonance imaging (MRI), Magnetic resonance spectroscopy (MRS) and a mixture of the two techniques (spectroscopic imaging) allow some physiological parameters, for example pH, to be 'imaged'. Using these methods, information on tissue bioenergetics and phospolipid membrane turnover, pH, hypoxia, oxygenation, and various aspects of vascularity including blood flow, angiogenesis, permeability and vascular volume can be obtained. In addition, MRS methods can be used for monitoring anticancer drugs (e.g. 5FU, ifosfamide) and their metabolites at their sites of action. The role of these state-of-the-art MR methods in imaging tumour physiology and their potential role in the clinic are discussed. (orig.)

  12. Nanoparticle-triggered in situ catalytic chemical reactions for tumour-specific therapy.

    Lin, Han; Chen, Yu; Shi, Jianlin

    2018-03-21

    Tumour chemotherapy employs highly cytotoxic chemodrugs, which kill both cancer and normal cells by cellular apoptosis or necrosis non-selectively. Catalysing/triggering the specific chemical reactions only inside tumour tissues can generate abundant and special chemicals and products locally to initiate a series of unique biological and pathologic effects, which may enable tumour-specific theranostic effects to combat cancer without bringing about significant side effects on normal tissues. Nevertheless, chemical reaction-initiated selective tumour therapy strongly depends on the advances in chemistry, materials science, nanotechnology and biomedicine. This emerging cross-disciplinary research area is substantially different from conventional cancer-theranostic modalities in clinics. In response to the fast developments in cancer theranostics based on intratumoural catalytic chemical reactions, this tutorial review summarizes the very-recent research progress in the design and synthesis of representative nanoplatforms with intriguing nanostructures, compositions, physiochemical properties and biological behaviours for versatile catalytic chemical reaction-enabled cancer treatments, mainly by either endogenous tumour microenvironment (TME) triggering or exogenous physical irradiation. These unique intratumoural chemical reactions can be used in tumour-starving therapy, chemodynamic therapy, gas therapy, alleviation of tumour hypoxia, TME-responsive diagnostic imaging and stimuli-responsive drug release, and even externally triggered versatile therapeutics. In particular, the challenges and future developments of such a novel type of cancer-theranostic modality are discussed in detail to understand the future developments and prospects in this research area as far as possible. It is highly expected that this kind of unique tumour-specific therapeutics by triggering specific in situ catalytic chemical reactions inside tumours would provide a novel but efficient

  13. Carcinoid Tumour of the Ovary

    Abstract. A case of bilateral carcinoid tumour of the ovary, with benign cystic teratoma in one ovary, in a 38 year old woman is presented. She had total abdominal hysterectomy, bilateral salpingoophorectomy, infracolic omentectomy and appendectomy. There was no macroscopic tumour in the vermiform appendix and the ...

  14. Ganoderma lucidum total triterpenes attenuate DLA induced ascites and EAC induced solid tumours in Swiss albino mice.

    Smina, T P; Mathew, J; Janardhanan, K K

    2016-04-30

    G. lucidum total triterpenes were assessed for its apoptosis-inducing and anti-tumour activities. The ability of the total triterpenes to induce apoptosis was evaluated in Dalton's lymphoma ascites (DLA) and Ehrlich's ascites carcinoma (EAC) cell lines. Total triterpenes were found to be highly cytotoxic to DLA and EAC cell lines with IC50 values 5 ± 0.32 and 7.9 ± 0.2 µg/ml respectively. Total triterpenes induced apoptosis in both cell lines which is evident from the DNA fragmentation assay. Anti-tumour activity was accessed using DLA induced solid and EAC induced ascites tumour models in Swiss albino mice. Administration of 10, 50 and 100 mg/kg b. wt. total triterpenes showed 11.86, 27.27 and 40.57% increase in life span of animals in ascites tumour model. Treatment with 10, 50 and 100 mg/kg b. wt. total triterpenes exhibited 76.86, 85.01 and 91.03% inhibition in tumour volume and 67.96, 72.38 and 77.90% inhibition in tumour weight respectively in the solid tumour model. The study reveals the significant dose-dependent anti-tumour activity of total triterpenes in both models. Total triterpenes were more active against the solid tumour than the ascites tumour. The anti-oxidant potential and ability to induce cell-specific apoptosis could be contributing to its anti-tumour activities.

  15. Minocycline blocks glial cell activation and ventilatory acclimatization to hypoxia.

    Stokes, Jennifer A; Arbogast, Tara E; Moya, Esteban A; Fu, Zhenxing; Powell, Frank L

    2017-04-01

    Ventilatory acclimatization to hypoxia (VAH) is the time-dependent increase in ventilation, which persists upon return to normoxia and involves plasticity in both central nervous system respiratory centers and peripheral chemoreceptors. We investigated the role of glial cells in VAH in male Sprague-Dawley rats using minocycline, an antibiotic that inhibits microglia activation and has anti-inflammatory properties, and barometric pressure plethysmography to measure ventilation. Rats received either minocycline (45mg/kg ip daily) or saline beginning 1 day before and during 7 days of chronic hypoxia (CH, Pi O 2  = 70 Torr). Minocycline had no effect on normoxic control rats or the hypercapnic ventilatory response in CH rats, but minocycline significantly ( P minocycline administration during only the last 3 days of CH did not reverse VAH. Microglia and astrocyte activation in the nucleus tractus solitarius was quantified from 30 min to 7 days of CH. Microglia showed an active morphology (shorter and fewer branches) after 1 h of hypoxia and returned to the control state (longer filaments and extensive branching) after 4 h of CH. Astrocytes increased glial fibrillary acidic protein antibody immunofluorescent intensity, indicating activation, at both 4 and 24 h of CH. Minocycline had no effect on glia in normoxia but significantly decreased microglia activation at 1 h of CH and astrocyte activation at 24 h of CH. These results support a role for glial cells, providing an early signal for the induction but not maintenance of neural plasticity underlying ventilatory acclimatization to hypoxia. NEW & NOTEWORTHY The signals for neural plasticity in medullary respiratory centers underlying ventilatory acclimatization to chronic hypoxia are unknown. We show that chronic hypoxia activates microglia and subsequently astrocytes. Minocycline, an antibiotic that blocks microglial activation and has anti-inflammatory properties, also blocks astrocyte activation in respiratory

  16. [Neonatal tumours and congenital malformations].

    Berbel Tornero, O; Ortega García, J A; Ferrís i Tortajada, J; García Castell, J; Donat i Colomer, J; Soldin, O P; Fuster Soler, J L

    2008-06-01

    The association between pediatric cancer and congenital abnormalities is well known but, there is no exclusive data on the neonatal period and the underlying etiopathogenic mechanisms are unknown. First, to analyze the frequency of neonatal tumours associated with congenital abnormalities; and second, to comment on the likely etiopathogenic hypotheses of a relationship between neonatal tumours and congenital abnormalities. Historical series of neonatal tumours from La Fe University Children's Hospital in Valencia (Spain), from January 1990 to December 1999. Histological varieties of neonatal tumours and associated congenital abnormalities were described. A systematic review of the last 25 years was carried out using Medline, Cancerlit, Index Citation Science and Embase. The search profile used was the combination of "neonatal/congenital-tumors/cancer/neoplasms" and "congenital malformations/birth defects". 72 neonatal tumours were identified (2.8% of all pediatric cancers diagnosed in our hospital) and in 15 cases (20.8%) there was some associated malformation, disease or syndrome. The association between congenital abnormalities and neonatal tumours were: a) angiomas in three patients: two patients with congenital heart disease with a choanal stenosis, laryngomalacia; b) neuroblastomas in two patients: horseshoe kidney with vertebral anomalies and other with congenital heart disease; c) teratomas in two patients: one with cleft palate with vertebral anomalies and other with metatarsal varus; d) one tumour of the central nervous system with Bochdaleck hernia; e) heart tumours in four patients with tuberous sclerosis; f) acute leukaemia in one patient with Down syndrome and congenital heart disease; g) kidney tumour in one case with triventricular hydrocephaly, and h) adrenocortical tumour: hemihypertrophy. The publications included the tumours diagnosed in different pediatric periods and without unified criteria to classify the congenital abnormalities. Little data

  17. Improving tumour response

    Bentzen, S.

    2003-01-01

    Radiation oncology is in the middle of the most exciting developments in its 100-year history. Progress in treatment planning and delivery, in medical imaging and in basic cancer and normal tissue biology is likely to change the indication for radiotherapy as well as the way it is prescribed and delivered. Technological and conceptual advances, in particular the development of the multi-leaf collimator and the concept of inverse treatment planning, have led to the introduction of intensity modulated radiation therapy (IMRT) with its capability to plan and deliver non-uniform dose distributions in the clinic. This has forced us to re-think radiation oncology: refining the indication for radiotherapy, optimizing the prescription of dose distributions and considering how, based on clinical evidence, radiation can best be combined with other treatment modalities, surgery, cytotoxic chemotherapy and biologically targeted therapies. The attraction of radiation therapy as an element of multi-modality cancer therapy is that it induces DNA damage that can be modulated in space and time. Progress in basic cancer biology, genomics and proteomics, as well as biological imaging provides novel avenues for individualization of cancer therapy and for biological optimization of radiotherapy. In improving cancer care, it is the therapeutic ratio, rather than tumour control per se, that must be optimised. Interestingly, the two main avenues for improving the effectiveness of radiotherapy currently being actively pursued in the clinic generally aim at different sides of the therapeutic ratio: 3D conformal radiotherapy and IMRT predominantly aim to reduce normal-tissue side effects - and by doing this, open the way for dose escalation that may lead to increased tumour control rates - whereas combined radio-chemotherapy aims to improve tumour response - while keeping the fingers crossed that this will not increase normal-tissue complications to the same extent. In parallel with these

  18. Notch-1 mediates hypoxia-induced angiogenesis in rheumatoid arthritis.

    Gao, Wei; Sweeney, Catherine; Connolly, Mary; Kennedy, Aisling; Ng, Chin Teck; McCormick, Jennifer; Veale, Douglas J; Fearon, Ursula

    2012-07-01

    To examine the effect of hypoxia on Notch-1 signaling pathway components and angiogenesis in inflammatory arthritis. The expression and regulation of Notch-1, its ligand delta-like protein 4 (DLL-4) and downstream signaling components (hairy-related transcription factor 1 [HRT-1], HRT-2), and hypoxia-inducible factor 1α (HIF-1α) under normoxic and hypoxic conditions (1-3%) were assessed in synovial tissue specimens from patients with inflammatory arthritis and controls and in human dermal microvascular endothelial cells (HDMECs) by immunohistology, dual immunofluorescence staining (Notch-1/factor VIII), Western blotting, and real-time polymerase chain reaction. In vivo synovial tissue oxygen levels (tissue PO2) were measured under direct visualization at arthroscopy. HDMEC activation under hypoxic conditions in the presence of Notch-1 small interfering RNA (siRNA), the γ-secretase inhibitor DAPT, or dimethyloxalylglycine (DMOG) was assessed by Matrigel tube formation assay, migration assay, invasion assay, and matrix metalloproteinase 2 (MMP-2)/MMP-9 zymography. Expression of Notch-1, its ligand DLL-4, and HRT-1 was demonstrated in synovial tissue, with the strongest expression localized to perivascular/vascular regions. Localization of Notch-1 to synovial endothelium was confirmed by dual immunofluorescence staining. Notch-1 intracellular domain (NICD) expression was significantly higher in synovial tissue from patients with tissue PO2 of PO2 of >20 mm Hg (>3% O2). Exposure of HDMECs to 3% hypoxia induced HIF-1α and NICD protein expression and DLL-4, HRT-1, and HRT-2 messenger RNA expression. DMOG directly induced NICD expression, while Notch-1 siRNA inhibited hypoxia-induced HIF-1α expression, suggesting that Notch-1/HIF-1α signaling is bidirectional. Finally, 3% hypoxia-induced angiogenesis, endothelial cell migration, endothelial cell invasion, and proMMP-2 and proMMP-9 activities were inhibited by Notch-1 siRNA and/or the γ-secretase inhibitor DAPT. Our

  19. Effects of prenatal hypoxia on schizophrenia-related phenotypes in heterozygous reeler mice: a gene × environment interaction study.

    Howell, Kristy R; Pillai, Anilkumar

    2014-08-01

    Both genetic and environmental factors play important roles in the pathophysiology of schizophrenia. Although prenatal hypoxia is a potential environmental factor implicated in schizophrenia, very little is known about the consequences of combining models of genetic risk factor with prenatal hypoxia. Heterozygous reeler (haploinsufficient for reelin; HRM) and wild-type (WT) mice were exposed to prenatal hypoxia (9% oxygen for two hour) or normoxia at embryonic day 17 (E17). Behavioral (Prepulse inhibition, Y-maze and Open field) and functional (regional volume in frontal cortex and hippocampus as well as hippocampal blood flow) tests were performed at 3 months of age. The levels of hypoxia and stress-related molecules such as hypoxia-inducible factor-1 α (HIF-1α), vascular endothelial factor (VEGF), VEGF receptor-2 (VEGFR2/Flk1) and glucocorticoid receptor (GR) were examined in frontal cortex and hippocampus at E18, 1 month and 3 months of age. In addition, serum VEGF and corticosterone levels were also examined. Prenatal hypoxia induced anxiety-like behavior in both HRM and WT mice. A significant reduction in hippocampal blood flow, but no change in brain regional volume was observed following prenatal hypoxia. Significant age and region-dependent changes in HIF-1α, VEGF, Flk1 and GR were found following prenatal hypoxia. Serum VEGF and corticosterone levels were found decreased following prenatal hypoxia. None of the above prenatal hypoxia-induced changes were either diminished or exacerbated due to reelin deficiency. These results argue against any gene-environment interaction between hypoxia and reelin deficiency. Copyright © 2014 Elsevier B.V. and ECNP. All rights reserved.

  20. Inhibitory PAS domain protein is a negative regulator of hypoxia-inducible gene expression

    Makino, Yuichi; Cao, Renhai; Svensson, Kristian; Bertilsson, Göran; Asman, Mikael; Tanaka, Hirotoshi; Cao, Yihai; Berkenstam, Anders; Poellinger, Lorenz

    2001-11-01

    Alteration of gene expression is a crucial component of adaptive responses to hypoxia. These responses are mediated by hypoxia-inducible transcription factors (HIFs). Here we describe an inhibitory PAS (Per/Arnt/Sim) domain protein, IPAS, which is a basic helix-loop-helix (bHLH)/PAS protein structurally related to HIFs. IPAS contains no endogenous transactivation function but demonstrates dominant negative regulation of HIF-mediated control of gene expression. Ectopic expression of IPAS in hepatoma cells selectively impairs induction of genes involved in adaptation to a hypoxic environment, notably the vascular endothelial growth factor (VEGF) gene, and results in retarded tumour growth and tumour vascular density in vivo. In mice, IPAS was predominantly expressed in Purkinje cells of the cerebellum and in corneal epithelium of the eye. Expression of IPAS in the cornea correlates with low levels of expression of the VEGF gene under hypoxic conditions. Application of an IPAS antisense oligonucleotide to the mouse cornea induced angiogenesis under normal oxygen conditions, and demonstrated hypoxia-dependent induction of VEGF gene expression in hypoxic corneal cells. These results indicate a previously unknown mechanism for negative regulation of angiogenesis and maintenance of an avascular phenotype.

  1. Cancer and tumour markers

    Osifo, B.

    1999-02-01

    Cancer has been a major cause of death world wide and in Nigeria there are six commonest forms of manifestation of cancer known. Of these prostrate cancer is the highest with 16% occurrence of all known cancers according to a study by the Histopathology Department of the UCH. Many factors, amongst them dietary, environmental, lifestyle, age and sedentary work are possible causes. With the global rise in incidents, the IAEA initiated the Tumour Marker Project as a means of screening cancers in 15 African countries including Nigeria. In Nigeria, 4 groups of the commonest cancers have been chosen for screening. These are prostrate cancer, primary liver cancer, cancer of the GI tract and trophoblastic cancer

  2. Ageing and cardiorespiratory response to hypoxia.

    Lhuissier, François J; Canouï-Poitrine, Florence; Richalet, Jean-Paul

    2012-11-01

    The risk of severe altitude-induced diseases is related to ventilatory and cardiac responses to hypoxia and is dependent on sex, age and exercise training status. However, it remains unclear how ageing modifies these physiological adaptations to hypoxia. We assessed the physiological responses to hypoxia with ageing through a cross-sectional 20 year study including 4675 subjects (2789 men, 1886 women; 14-85 years old) and a longitudinal study including 30 subjects explored at a mean 10.4 year interval. The influence of sex, training status and menopause was evaluated. The hypoxia-induced desaturation and the ventilatory and cardiac responses to hypoxia at rest and exercise were measured. In men, ventilatory response to hypoxia increased (P ageing. Cardiac response to hypoxia was blunted with ageing in both sexes (P ageing. These adaptive responses were less pronounced or absent in post-menopausal women (P ageing in men while cardiac response is blunted with ageing in both sexes. Training aggravates desaturation at exercise in hypoxia, improves the ventilatory response and limits the ageing-induced blunting of cardiac response to hypoxia. Training limits the negative effects of menopause in cardiorespiratory adaptations to hypoxia.

  3. Exercise Improves Mood State in Normobaric Hypoxia.

    Seo, Yongsuk; Fennell, Curtis; Burns, Keith; Pollock, Brandon S; Gunstad, John; McDaniel, John; Glickman, Ellen

    2015-11-01

    The purpose of this study was to quantify the efficacy of using exercise to alleviate the impairments in mood state associated with hypoxic exposure. Nineteen young, healthy men completed Automated Neuropsychological Assessment Metrics-4(th) Edition (ANAM4) versions of the mood state test before hypoxia exposure, after 60 min of hypoxia exposure (12.5% O(2)), and during and after two intensities of cycling exercise (40% and 60% adjusted Vo(2max)) under the same hypoxic conditions. Peripheral oxygen saturation (Spo(2)) and regional cerebral oxygen saturation (rSo(2)) were continuously monitored. At rest in hypoxia, Total Mood Disturbance (TMD) was significantly increased compared to baseline in both the 40% and 60% groups. TMD was significantly decreased during exercise compared to rest in hypoxia. TMD was also significantly decreased during recovery compared to rest in hypoxia. Spo(2) significantly decreased at 60 min rest in hypoxia, during exercise, and recovery compared to baseline. Regional cerebral oxygen saturation was also reduced at 60 min rest in hypoxia, during exercise, and recovery compared to baseline. The current study demonstrated that exercise at 40% and 60% of adjusted Vo(2max) attenuated the adverse effects of hypoxia on mood. These findings may have significant applied value, as negative mood states are known to impair performance in hypoxia. Further studies are needed to replicate the current finding and to clarify the possible mechanisms associated with the potential benefits of exercise on mood state in normobaric hypoxia.

  4. Approximate Simulation of Acute Hypobaric Hypoxia with Normobaric Hypoxia

    Conkin, J.; Wessel, J. H., III

    2011-01-01

    INTRODUCTION. Some manufacturers of reduced oxygen (O2) breathing devices claim a comparable hypobaric hypoxia (HH) training experience by providing F(sub I) O2 pO2) of the target altitude. METHODS. Literature from investigators and manufacturers indicate that these devices may not properly account for the 47 mmHg of water vapor partial pressure that reduces the inspired partial pressure of O2 (P(sub I) O2). Nor do they account for the complex reality of alveolar gas composition as defined by the Alveolar Gas Equation. In essence, by providing iso-pO2 conditions for normobaric hypoxia (NH) as for HH exposures the devices ignore P(sub A)O2 and P(sub A)CO2 as more direct agents to induce signs and symptoms of hypoxia during acute training exposures. RESULTS. There is not a sufficient integrated physiological understanding of the determinants of P(sub A)O2 and P(sub A)CO2 under acute NH and HH given the same hypoxic pO2 to claim a device that provides isohypoxia. Isohypoxia is defined as the same distribution of hypoxia signs and symptoms under any circumstances of equivalent hypoxic dose, and hypoxic pO2 is an incomplete hypoxic dose. Some devices that claim an equivalent HH experience under NH conditions significantly overestimate the HH condition, especially when simulating altitudes above 10,000 feet (3,048 m). CONCLUSIONS. At best, the claim should be that the devices provide an approximate HH experience since they only duplicate the ambient pO2 at sea level as at altitude (iso-pO2 machines). An approach to reduce the overestimation is to at least provide machines that create the same P(sub I)O2 (iso-P(sub I)O2 machines) conditions at sea level as at the target altitude, a simple software upgrade.

  5. A novel concept for tumour targeting with radiation: Inverse dose-painting or targeting the "Low Drug Uptake Volume".

    Yaromina, Ala; Granzier, Marlies; Biemans, Rianne; Lieuwes, Natasja; van Elmpt, Wouter; Shakirin, Georgy; Dubois, Ludwig; Lambin, Philippe

    2017-09-01

    We tested a novel treatment approach combining (1) targeting radioresistant hypoxic tumour cells with the hypoxia-activated prodrug TH-302 and (2) inverse radiation dose-painting to boost selectively non-hypoxic tumour sub-volumes having no/low drug uptake. 18 F-HX4 hypoxia tracer uptake measured with a clinical PET/CT scanner was used as a surrogate of TH-302 activity in rhabdomyosarcomas growing in immunocompetent rats. Low or high drug uptake volume (LDUV/HDUV) was defined as 40% of the GTV with the lowest or highest 18 F-HX4 uptake, respectively. Two hours post TH-302/saline administration, animals received either single dose radiotherapy (RT) uniformly (15 or 18.5Gy) or a dose-painted non-uniform radiation (15Gy) with 50% higher dose to LDUV or HDUV (18.5Gy). Treatment plans were created using Eclipse treatment planning system and radiation was delivered using VMAT. Tumour response was quantified as time to reach 3 times starting tumour volume. Non-uniform RT boosting tumour sub-volume with low TH-302 uptake (LDUV) was superior to the same dose escalation to HDUV (pvolume with no/low activity of hypoxia-activated prodrugs. This strategy applies on average a lower radiation dose and is as effective as uniform dose escalation to the entire tumour. It could be applied to other type of drugs provided that their distribution can be imaged. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  6. VIP secreting tumours in infancy

    Davies, R.P.; Slavotinek, J.P.; Dorney, S.F.A.

    1990-01-01

    Vasoactive intestinal polypeptide (VIP) secreting neural crest tumours are an uncommon but important treatable cause of intractable childhood diarrhoea. The radiological appearances of two cases are presented with a review of radiological findings in childhood VIP secreting neural crest tumours. Twenty eight cases of childhood VIP secreting neural crest tumours were reviewed. Nineteen (68%) were ganglioneuroblastomas and nine (32%) were ganglioneuromas. The majority of tumours (66%) were in a paravertebral location in the abdomen indicating that a search for such a tumour should be initiated at this site. Eighteen of the twenty eight cases reviewed discussed relevant radiological investigations. Calcification was detected in 50% of abdominal radiographs. Gut dilatation was often a prominent feature. A mass was detected in 5 of 5 cases where ultrasound findings were reported, and seven of seven cases with CT findings reported. Prior to the availability of CT and ultrasound the most useful investigation was IVU which demonstrated evidence of a mass in 5 of 9 cases. The presence of paravertebral calcification and gut dilatation on the plain radiograph of a child with intractable diarrhoea suggests the presence of a VIP secreting neural crest tumour. If an abdominal tumour is not found in the appropriate clinical setting and VIP levels are elevated, a widespread search of the paravertebral region is indicated. (orig.)

  7. Hypoxia changes the expression of the epidermal growth factor (EGF) system in human hearts and cultured cardiomyocytes

    Munk, Mathias; Memon, Ashfaque Ahmed; Goetze, Jens Peter

    2012-01-01

    by treatment with trastuzumab (20 nM). This resulted in inhibition of cardiomyocyte proliferation, but interestingly only in hypoxic cells. Co-treatment of HL-1 cells with HB-EGF (10 nM) but not with NRG-1 (5 ng/ml) rescued the cardiomyocytes from HER2 inhibition. HL-1 cardiomyocytes exposed to hypoxia...... revealed nuclear translocation of activated MAPK and the activity of this downstream signaling molecule was decreased by HER2 inhibition (20 nM trastuzumab), and re-established by HB-EGF (10 nM). CONCLUSIONS/SIGNIFICANCE: Hypoxia in the human heart alters the expression of the EGF system. Mimicking the HER...

  8. Primary vertebral tumours in children

    Kozlowski, K.; Beluffi, G.; Masel, J.; Diard, F.; Ferrari-Ciboldi, F.; Le Dosseur, P.; Labatut, J.

    1984-03-01

    20 cases of primary benign and malignant bone tumours in children were reported. The most common tumours were Ewing's sarcoma, aneurismal bone cyst, benign osteoblastoma and osteoid osteoma. Some rare primary bone tumours in children (osteochondroma, chondroblastoma 6F, primary lymphoma of bone and neurofibromatosis with unusual cervical spinal changes) were also reported. The authors believe that radiographic findings together with clinical history and clinical examination may yield a high percentage of accurate diagnoses. Although microscopy is essential in the final diagnosis, the microscopic report should be also accepted with caution.

  9. Chronic hypoxia alters maternal uterine and fetal hemodynamics in the full-term pregnant guinea pig.

    Turan, Sifa; Aberdeen, Graham W; Thompson, Loren P

    2017-10-01

    Placental hypoxia is associated with maternal hypertension, placental insufficiency, and fetal growth restriction. In the pregnant guinea pig, prenatal hypoxia during early gestation inhibits cytotrophoblast invasion of spiral arteries, increases maternal blood pressure, and induces fetal growth restriction. In this study the impact of chronic maternal hypoxia on fetal heart structure was evaluated using four-dimensional echocardiography with spatiotemporal image correlation and tomographic ultrasound, and uterine and umbilical artery resistance/pulsatility indexes and fetal heart function were evaluated using pulsed-wave Doppler ultrasound. Pregnant guinea pigs were exposed to normoxia ( n = 7) or hypoxia (10.5% O 2 , n = 9) at 28-30 days gestation, which was maintained until full term (65 days). At full term, fetal heart structure and outflow tracts were evaluated in the four-chamber view. Fetal heart diastolic function was assessed by E wave-to-A wave diastolic filling ratios (E/A ratios) of both ventricles and systolic function by the myocardial performance index (or Tie) of left ventricles of normoxic ( n = 21) and hypoxic ( n = 17) fetuses. There were no structural abnormalities in fetal hearts. However, hypoxia induced asymmetric fetal growth restriction and increased the placental/fetal weight compared with normoxic controls. Hypoxia increased Doppler resistance and pulsatility indexes in the uterine, but not umbilical, arteries, had no effect on the Tie index, and increased the E/A ratio in left, but not right, ventricles. Thus, prolonged hypoxia, starting at midgestation, increases uterine artery resistance and generates fetal growth restriction at full term. Furthermore, the enhanced cardiac diastolic filling with no changes in systolic function or umbilical artery resistance suggests that the fetal guinea pig systemic circulation undergoes a compensated, adaptive response to prolonged hypoxia exposure. Copyright © 2017 the American Physiological

  10. VEGF secretion during hypoxia depends on free radicals-induced Fyn kinase activity in mast cells

    Garcia-Roman, Jonathan; Ibarra-Sanchez, Alfredo; Lamas, Monica; Gonzalez Espinosa, Claudia

    2010-01-01

    Research highlights: → Bone marrow-derived mast cells (BMMCs) secrete functional VEGF but do not degranulate after Cobalt chloride-induced hypoxia. → CoCl 2 -induced VEGF secretion in mast cells occurs by a Ca 2+ -insensitive but brefeldin A and Tetanus toxin-sensitive mechanism. → Trolox and N-acetylcysteine inhibit hypoxia-induced VEGF secretion but only Trolox inhibits FcεRI-dependent anaphylactic degranulation in mast cells. → Src family kinase Fyn activation after free radical production is necessary for hypoxia-induced VEGF secretion in mast cells. -- Abstract: Mast cells (MC) have an important role in pathologic conditions such as asthma and chronic obstructive pulmonary disease (COPD), where hypoxia conduce to deleterious inflammatory response. MC contribute to hypoxia-induced angiogenesis producing factors such as vascular endothelial growth factor (VEGF), but the mechanisms behind the control of hypoxia-induced VEGF secretion in this cell type is poorly understood. We used the hypoxia-mimicking agent cobalt chloride (CoCl 2 ) to analyze VEGF secretion in murine bone marrow-derived mast cells (BMMCs). We found that CoCl 2 promotes a sustained production of functional VEGF, able to induce proliferation of endothelial cells in vitro. CoCl 2 -induced VEGF secretion was independent of calcium rise but dependent on tetanus toxin-sensitive vesicle-associated membrane proteins (VAMPs). VEGF exocytosis required free radicals formation and the activation of Src family kinases. Interestingly, an important deficiency on CoCl 2 -induced VEGF secretion was observed in Fyn kinase-deficient BMMCs. Moreover, Fyn kinase was activated by CoCl 2 in WT cells and this activation was prevented by treatment with antioxidants such as Trolox and N-acetylcysteine. Our results show that BMMCs are able to release VEGF under hypoxic conditions through a tetanus toxin-sensitive mechanism, promoted by free radicals-dependent Fyn kinase activation.

  11. Activity of the hypoxia-activated prodrug, TH-302, in preclinical human acute myeloid leukemia models.

    Portwood, Scott; Lal, Deepika; Hsu, Yung-Chun; Vargas, Rodrigo; Johnson, Megan K; Wetzler, Meir; Hart, Charles P; Wang, Eunice S

    2013-12-01

    Acute myeloid leukemia (AML) is an aggressive hematologic neoplasm. Recent evidence has shown the bone marrow microenvironment in patients with AML to be intrinsically hypoxic. Adaptive cellular responses by leukemia cells to survive under low oxygenation also confer chemoresistance. We therefore asked whether therapeutic exploitation of marrow hypoxia via the hypoxia-activated nitrogen mustard prodrug, TH-302, could effectively inhibit AML growth. We assessed the effects of hypoxia and TH-302 on human AML cells, primary samples, and systemic xenograft models. We observed that human AML cells and primary AML colonies cultured under chronic hypoxia (1% O2, 72 hours) exhibited reduced sensitivity to cytarabine-induced apoptosis as compared with normoxic controls. TH-302 treatment resulted in dose- and hypoxia-dependent apoptosis and cell death in diverse AML cells. TH-302 preferentially decreased proliferation, reduced HIF-1α expression, induced cell-cycle arrest, and enhanced double-stranded DNA breaks in hypoxic AML cells. Hypoxia-induced reactive oxygen species by AML cells were also diminished. In systemic human AML xenografts (HEL, HL60), TH-302 [50 mg/kg intraperitoneally (i.p.) 5 times per week] inhibited disease progression and prolonged overall survival. TH-302 treatment reduced the number of hypoxic cells within leukemic bone marrows and was not associated with hematologic toxicities in nonleukemic or leukemic mice. Later initiation of TH-302 treatment in advanced AML disease was as effective as earlier TH-302 treatment in xenograft models. Our results establish the preclinical activity of TH-302 in AML and provide the rationale for further clinical studies of this and other hypoxia-activated agents for leukemia therapy. ©2013 AACR.

  12. VEGF secretion during hypoxia depends on free radicals-induced Fyn kinase activity in mast cells

    Garcia-Roman, Jonathan; Ibarra-Sanchez, Alfredo; Lamas, Monica [Departamento de Farmacobiologia, Centro de Investigacion y de Estudios Avanzados del IPN (Cinvestav, IPN) (Mexico); Gonzalez Espinosa, Claudia, E-mail: cgonzal@cinvestav.mx [Departamento de Farmacobiologia, Centro de Investigacion y de Estudios Avanzados del IPN (Cinvestav, IPN) (Mexico)

    2010-10-15

    Research highlights: {yields} Bone marrow-derived mast cells (BMMCs) secrete functional VEGF but do not degranulate after Cobalt chloride-induced hypoxia. {yields} CoCl{sub 2}-induced VEGF secretion in mast cells occurs by a Ca{sup 2+}-insensitive but brefeldin A and Tetanus toxin-sensitive mechanism. {yields} Trolox and N-acetylcysteine inhibit hypoxia-induced VEGF secretion but only Trolox inhibits Fc{epsilon}RI-dependent anaphylactic degranulation in mast cells. {yields} Src family kinase Fyn activation after free radical production is necessary for hypoxia-induced VEGF secretion in mast cells. -- Abstract: Mast cells (MC) have an important role in pathologic conditions such as asthma and chronic obstructive pulmonary disease (COPD), where hypoxia conduce to deleterious inflammatory response. MC contribute to hypoxia-induced angiogenesis producing factors such as vascular endothelial growth factor (VEGF), but the mechanisms behind the control of hypoxia-induced VEGF secretion in this cell type is poorly understood. We used the hypoxia-mimicking agent cobalt chloride (CoCl{sub 2}) to analyze VEGF secretion in murine bone marrow-derived mast cells (BMMCs). We found that CoCl{sub 2} promotes a sustained production of functional VEGF, able to induce proliferation of endothelial cells in vitro. CoCl{sub 2}-induced VEGF secretion was independent of calcium rise but dependent on tetanus toxin-sensitive vesicle-associated membrane proteins (VAMPs). VEGF exocytosis required free radicals formation and the activation of Src family kinases. Interestingly, an important deficiency on CoCl{sub 2}-induced VEGF secretion was observed in Fyn kinase-deficient BMMCs. Moreover, Fyn kinase was activated by CoCl{sub 2} in WT cells and this activation was prevented by treatment with antioxidants such as Trolox and N-acetylcysteine. Our results show that BMMCs are able to release VEGF under hypoxic conditions through a tetanus toxin-sensitive mechanism, promoted by free radicals

  13. The Janus face of death receptor signalling during tumour immunoediting.

    Eimear O' Reilly

    2016-10-01

    Full Text Available Cancer immune-surveillance is essential for the inhibition of carcinogenesis. Malignantly transformed cells can be recognised by both the innate and adaptive immune systems through different mechanisms. Immune effector cells induce extrinsic cell death in the identified tumour cells by expressing death ligand cytokines of the tumour necrosis factor ligand family. However, some tumour cells can escape immune elimination and progress. Acquisition of resistance to the death-ligand induced apoptotic pathway can be obtained through cleavage of effector-cell expressed death-ligands into a poorly active form, mutations or silencing of the death receptors or overexpression of decoy receptors and pro-survival proteins. Although the immune system is highly effective in the elimination of malignantly transformed cells, abnormal/ dysfunctional death-ligand signalling curbs its cytotoxicity. Moreover, death receptors can also transmit pro-survival and pro-migratory signals. Consequently, dysfunctional death receptor-mediated apoptosis/necroptosis signalling does not only give a passive resistance against cell death, but actively drives tumour cell motility, invasion and contributes to consequent metastasis. This dual contribution of the death ligand-death receptor signalling in both the early, elimination phase and then in the late, escape phase of the tumour immunoediting process is discussed in this review. Death receptor agonists still hold potential for cancer therapy since they can execute the tumour-eliminating immune-effector function even in the absence of activation of the immune system against the tumour. The opportunities and challenges of developing death receptor agonists into effective cancer therapeutics are also discussed.

  14. Hypoxia-targeted suicidal gene therapy system enhances antitumor effects of radiotherapy

    Liu Junye; Guo Yao; Guo Guozhen

    2006-01-01

    Objective: To explore the effects of hypoxia-targeted suicidal gene therapy system combined with radiotherapy on pancreatic cancer. Methods: The recombinant adenovirus Ad-5HRE/hCMVmp-BCD was constructed by DNA recombinant technique. Western blot was used to detect hypoxia-induced expression of bacterial cytosine deaminase (BCD). Cell growth inhibition assay was used to determine the sensitivity of human pancreatic cancer cells MIA-PACA2 to 5-fluorocytosine (5-FC). Tumor xenograft growth delay assays was used to evaluate the effects of Ad-5HRE/hCMVmp-BCD/5-FC combined with radiotherapy on pancreatic cancer. Results: Western blot analysis demonstrated that hypoxia-induced BCD protein expression was achieved in MIA-PACA2 cells infected with Ad-5HRE/hCMVmp-BCD. With hypoxia treatment, the sensitivity of MIA-PACA2 cells infected with Ad-5HRE/hCMVmp-BCD to 5-FC significantly increased. Administration of either Ad-5HRE/hCMVmp-BCD/5-FC or radiotherapy could inhibit the growth of MIA-PACA2 xenografts in nude mice. Moreover, combination of Ad-5HRE/hCMVmp-BCD/5-FC could significantly enhance suppressing effects of radiotherapy on MIA-PACA2 xenografts. Conclusion: Hypoxia-targeted suicidal gene therapy system Ad-5HRE/hCMVmp-BCD/5-FC could enhance antitumor effects of radiotherapy on pancreatic cancer and can be used as a powerful adjunct to conventional radiotherapy. (authors)

  15. Regulation of Cited2 expression provides a functional link between translational and transcriptional responses during hypoxia

    Beucken, Twan van den; Magagnin, Michael G.; Savelkouls, Kim; Lambin, Philippe; Koritzinsky, Marianne; Wouters, Bradly G.

    2007-01-01

    Background and purpose: Protein synthesis rates are greatly reduced under hypoxic conditions as a consequence of an overall inhibition of mRNA translation. Certain specific mRNA species have the ability to escape this general translational repression. At the cellular level this results in differential protein expression during hypoxic conditions. The objective of this study was to characterize the translational regulation of the postulated HIF-1α antagonist Cited2. Materials and methods: DU145 prostate carcinoma cells and mouse embryonic fibroblasts with a homozygous knock-in mutation for eIF2α (S51A) or wild-type eIF2α were exposed to severe hypoxia after which both total mRNA and efficiently translated mRNA were isolated. Quantitative RT-PCR was used to measure and compare changes in transcription (total mRNA) with changes in translation (efficiently translated mRNA fraction). Results: We show using HIF-1α null MEF cells that transcriptional induction of Cited2 during hypoxia is dependent on HIF-1α. Although global mRNA translation is inhibited during hypoxia Cited2 mRNA remains efficiently translated. An evolutionary conserved upstream open reading frame (uORF) in the 5'UTR of Cited2 did not stimulate translation in an eIF2α dependent manner during hypoxia. Conclusions: Selective translation Cited2 by an eIF2α independent mechanism establishes a link between translation and HIF-1 dependent transcription during hypoxia

  16. The zinc transporter ZIP12 regulates the pulmonary vascular response to chronic hypoxia.

    Zhao, Lan; Oliver, Eduardo; Maratou, Klio; Atanur, Santosh S; Dubois, Olivier D; Cotroneo, Emanuele; Chen, Chien-Nien; Wang, Lei; Arce, Cristina; Chabosseau, Pauline L; Ponsa-Cobas, Joan; Frid, Maria G; Moyon, Benjamin; Webster, Zoe; Aldashev, Almaz; Ferrer, Jorge; Rutter, Guy A; Stenmark, Kurt R; Aitman, Timothy J; Wilkins, Martin R

    2015-08-20

    The typical response of the adult mammalian pulmonary circulation to a low oxygen environment is vasoconstriction and structural remodelling of pulmonary arterioles, leading to chronic elevation of pulmonary artery pressure (pulmonary hypertension) and right ventricular hypertrophy. Some mammals, however, exhibit genetic resistance to hypoxia-induced pulmonary hypertension. We used a congenic breeding program and comparative genomics to exploit this variation in the rat and identified the gene Slc39a12 as a major regulator of hypoxia-induced pulmonary vascular remodelling. Slc39a12 encodes the zinc transporter ZIP12. Here we report that ZIP12 expression is increased in many cell types, including endothelial, smooth muscle and interstitial cells, in the remodelled pulmonary arterioles of rats, cows and humans susceptible to hypoxia-induced pulmonary hypertension. We show that ZIP12 expression in pulmonary vascular smooth muscle cells is hypoxia dependent and that targeted inhibition of ZIP12 inhibits the rise in intracellular labile zinc in hypoxia-exposed pulmonary vascular smooth muscle cells and their proliferation in culture. We demonstrate that genetic disruption of ZIP12 expression attenuates the development of pulmonary hypertension in rats housed in a hypoxic atmosphere. This new and unexpected insight into the fundamental role of a zinc transporter in mammalian pulmonary vascular homeostasis suggests a new drug target for the pharmacological management of pulmonary hypertension.

  17. Apelin Protects Primary Rat Retinal Pericytes from Chemical Hypoxia-Induced Apoptosis

    Li Chen

    2015-01-01

    Full Text Available Pericytes are a population of cells that participate in normal vessel architecture and regulate permeability. Apelin, as the endogenous ligand of G protein-coupled receptor APJ, participates in a number of physiological and pathological processes. To date, the effect of apelin on pericyte is not clear. Our study aimed to investigate the potential protection mechanisms of apelin, with regard to primary rat retinal pericytes under hypoxia. Immunofluorescence staining revealed that pericytes colocalized with APJ in the fibrovascular membranes dissected from proliferative diabetic retinopathy patients. In the in vitro studies, we first demonstrated that the expression of apelin/APJ was upregulated in pericytes under hypoxia, and apelin increased pericytes proliferation and migration. Moreover, knockdown of apelin in pericyte was achieved via lentivirus-mediated RNA interference. After the inhibition of apelin, pericytes proliferation was inhibited significantly in hypoxia culture condition. Furthermore, exogenous recombinant apelin effectively prevented hypoxia-induced apoptosis through downregulating active-caspase 3 expression and increasing the ratio of B cell lymphoma-2 (Bcl-2/Bcl-2 associated X protein (Bax in pericytes. These results suggest that apelin suppressed hypoxia-induced pericytes injury, which indicated that apelin could be a potential therapeutic target for retinal angiogenic diseases.

  18. The role of hypoxia inducible factor 1 (HIF-1) in hypoxia induced apoptosis

    Greijer, A.E.; Wall, E. van der

    2004-01-01

    Apoptosis can be induced in response to hypoxia. The severity of hypoxia determines whether cells become apoptotic or adapt to hypoxia and survive. A hypoxic environment devoid of nutrients prevents the cell undergoing energy dependent apoptosis and cells become necrotic. Apoptosis regulatory

  19. Cystic tumours of the pancreas

    Itai, Y. [Dept. of Radiology, Inst. of Clinical Medicine, Tsukuba Univ. (Japan); Ohtomo, K. [Univ. of Tokyo Hospital, Tokyo (Japan)

    1996-12-01

    In this pictorial essay we present the typical appearances of cystic pancreatic tumours, the wide spectrum of their features, and differential features among cystic pancreatic masses with an emphasis on CT. Pseudocysts are the most common cystic lesion in the pancreas and can be induced by pancreatitis, trauma or surgery. Pseudocysts appear as a round cystic mass with a definite wall. However, they can mimic cystic tumours associated with internal septation and/or necrotic mass of various shapes. Conversely, cystic tumours can appear as a simple cyst lacking any thickening of wall, septation or mural nodule. Pancreatic carcinoma not infrequently induces secondary cysts upstream of the obstructed pancreatic duct. The cysts are pseudocysts or retention cysts in nature. When cysts are formed in the pancreatic parenchyma or adjacent to pancreatic carcinoma they may mimic cystic tumour. (orig./VHE)

  20. Cystic tumours of the pancreas

    Itai, Y.; Ohtomo, K.

    1996-01-01

    In this pictorial essay we present the typical appearances of cystic pancreatic tumours, the wide spectrum of their features, and differential features among cystic pancreatic masses with an emphasis on CT. Pseudocysts are the most common cystic lesion in the pancreas and can be induced by pancreatitis, trauma or surgery. Pseudocysts appear as a round cystic mass with a definite wall. However, they can mimic cystic tumours associated with internal septation and/or necrotic mass of various shapes. Conversely, cystic tumours can appear as a simple cyst lacking any thickening of wall, septation or mural nodule. Pancreatic carcinoma not infrequently induces secondary cysts upstream of the obstructed pancreatic duct. The cysts are pseudocysts or retention cysts in nature. When cysts are formed in the pancreatic parenchyma or adjacent to pancreatic carcinoma they may mimic cystic tumour. (orig./VHE)

  1. Tumour markers in urology

    Schmid, L.; Fornara, P.; Fabricius, P.G.

    1988-01-01

    The same applies essentially also for the bladder carcinomas: There is no reliable marker for these cancers which would be useful for clinical purposes. TPA has proven to be too non-specific in malignoma-detection and therefore hardly facilitates clinical decision-making in individual cases. The CEA is not sensitive enough to be recommendable for routine application. However, in advanced stages a CEA examination may be useful if applied within the scope of therapeutic efforts made to evaluate efficacy. In cases of carcinomas of the prostate the sour prostate-specific phosphatase (SPP) and, more recently, especially the prostate-specific antigen (PSA) have proven in follow-up and therapy monitoring, whereby the PSA is superior to the SPP. Nevertheless, both these markers should be employed in therapy monitoring because differences in behaviour will be observed when the desired treatment effect is only achieved in one of the two markers producing tumour cell clonuses. Both markers, but especially the PSA, are quite reliably in agreement with the result of the introduced chemo-/hormone therapy, whereby an increase may be a sure indicator of relapse several months previous to clinical symptoms, imaging procedures, so-called routine laboratory results and subjective complaints. However, none of the 2 markers is appropriate for the purposes of screening or early diagnosis of carcinomas of the prostate. (orig.) [de

  2. Renal angiomyoadenomatous tumour: Imaging features

    Sahni, V. Anik; Hirsch, Michelle S.; Silverman, Stuart G.

    2012-01-01

    Renal angiomyoadenomatous tumour is a rare, recently described neoplasm with a distinctive histological appearance. Although reported in the pathology literature, to our knowledge, no prior reports have described its imaging appearance. We describe the computed tomography and magnetic resonance imaging features of an incidentally detected renal angiomyoadenomatous tumour that appeared as a well-marginated, solid T2-hypointense enhancing mass, in a 50-year-old woman. It is indistinguishable from a variety of benign and malignant renal neoplasms. PMID:23093565

  3. Paediatric laryngeal granular cell tumour

    Dauda Ayuba

    2009-01-01

    Full Text Available Granular cell tumour (GCT affecting the larynx is not common, especially in children. Most cases are apt to be confused with respiratory papilloma and may even be mistaken for a malignant neoplasia. We present a case of laryngeal GCT in a 12-year-old child to emphasize that the tumour should be regarded in the differential of growths affecting the larynx in children.

  4. Effects of copper, hypoxia and acute temperature shifts on mitochondrial oxidation in rainbow trout (Oncorhynchus mykiss) acclimated to warm temperature

    Sappal, Ravinder; Fast, Mark; Stevens, Don; Kibenge, Fred; Siah, Ahmed; Kamunde, Collins

    2015-01-01

    Highlights: • Warm acclimation reduced the electron transport system (ETS) efficiency. • Warm acclimation altered the effects of acute temperature shift, hypoxia and Cu on ETS. • Warm acclimation increased thermal sensitivity of state 3 and reduced that of state 4. • Cu stimulated while hypoxia inhibited ETS respiratory activity. • Interactions of Cu and hypoxia on the ETS and plasma metabolites were antagonistic. - Abstract: Temperature fluctuations, hypoxia and metals pollution frequently occur simultaneously or sequentially in aquatic systems and their interactions may confound interpretation of their biological impacts. With a focus on energy homeostasis, the present study examined how warm acclimation influences the responses and interactions of acute temperature shift, hypoxia and copper (Cu) exposure in fish. Rainbow trout (Oncorhynchus mykiss) were acclimated to cold (11 °C; control) and warm (20 °C) temperature for 3 weeks followed by exposure to environmentally realistic levels of Cu and hypoxia for 24 h. Subsequently, mitochondrial electron transport system (ETS) respiratory activity supported by complexes I–IV (CI–IV), plasma metabolites and condition indices were measured. Warm acclimation reduced fish condition, induced aerobic metabolism and altered the responses of fish to acute temperature shift, hypoxia and Cu. Whereas warm acclimation decelerated the ETS and increased the sensitivity of maximal oxidation rates of the proximal (CI and II) complexes to acute temperature shift, it reduced the thermal sensitivity of state 4 (proton leak). Effects of Cu with and without hypoxia were variable depending on the acclimation status and functional index. Notably, Cu stimulated respiratory activity in the proximal ETS segments, while hypoxia was mostly inhibitory and minimized the stimulatory effect of Cu. The effects of Cu and hypoxia were modified by temperature and showed reciprocal antagonistic interaction on the ETS and plasma

  5. Effects of copper, hypoxia and acute temperature shifts on mitochondrial oxidation in rainbow trout (Oncorhynchus mykiss) acclimated to warm temperature

    Sappal, Ravinder [Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island C1A 4P3 (Canada); Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island C1A 4P3 (Canada); Fast, Mark [Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island C1A 4P3 (Canada); Stevens, Don [Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island C1A 4P3 (Canada); Kibenge, Fred [Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island C1A 4P3 (Canada); Siah, Ahmed [British Columbia Centre for Aquatic Health Sciences, 871A Island Highway, Campbell River, British Columbia V9W 2C2 (Canada); Kamunde, Collins, E-mail: ckamunde@upei.ca [Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island C1A 4P3 (Canada)

    2015-12-15

    Highlights: • Warm acclimation reduced the electron transport system (ETS) efficiency. • Warm acclimation altered the effects of acute temperature shift, hypoxia and Cu on ETS. • Warm acclimation increased thermal sensitivity of state 3 and reduced that of state 4. • Cu stimulated while hypoxia inhibited ETS respiratory activity. • Interactions of Cu and hypoxia on the ETS and plasma metabolites were antagonistic. - Abstract: Temperature fluctuations, hypoxia and metals pollution frequently occur simultaneously or sequentially in aquatic systems and their interactions may confound interpretation of their biological impacts. With a focus on energy homeostasis, the present study examined how warm acclimation influences the responses and interactions of acute temperature shift, hypoxia and copper (Cu) exposure in fish. Rainbow trout (Oncorhynchus mykiss) were acclimated to cold (11 °C; control) and warm (20 °C) temperature for 3 weeks followed by exposure to environmentally realistic levels of Cu and hypoxia for 24 h. Subsequently, mitochondrial electron transport system (ETS) respiratory activity supported by complexes I–IV (CI–IV), plasma metabolites and condition indices were measured. Warm acclimation reduced fish condition, induced aerobic metabolism and altered the responses of fish to acute temperature shift, hypoxia and Cu. Whereas warm acclimation decelerated the ETS and increased the sensitivity of maximal oxidation rates of the proximal (CI and II) complexes to acute temperature shift, it reduced the thermal sensitivity of state 4 (proton leak). Effects of Cu with and without hypoxia were variable depending on the acclimation status and functional index. Notably, Cu stimulated respiratory activity in the proximal ETS segments, while hypoxia was mostly inhibitory and minimized the stimulatory effect of Cu. The effects of Cu and hypoxia were modified by temperature and showed reciprocal antagonistic interaction on the ETS and plasma

  6. Surgical approach to pineal tumours.

    Pluchino, F; Broggi, G; Fornari, M; Franzini, A; Solero, C L; Allegranza, A

    1989-01-01

    During a period of 10 years (1977-1986) 40 cases of tumour of the pineal region have been treated at the Istituto Neurologico "C. Besta"-of Milan. Out of these 40 cases, 27 (67.5%) were in the paediatric (10-15 years) or juvenile (15-20 years) age at the time of operation. Since 1983 a specific diagnostic and therapeutic protocol has been adopted and thereafter direct surgical removal of the tumour was performed only when the neuroradiological investigations were highly suggestive of a benign extrinsic lesion. Sixteen cases in this series underwent direct surgical removal; in the remaining 24 cases stereotactic biopsy of the tumour was performed in the first instance. On the basis of the histological diagnosis obtained by this procedure surgical excision of the tumour (9 cases) or radiotherapy (15 cases) was then performed. 25 cases underwent surgical removal of the lesion. In all the cases the infratentorial supracerebellar approach as introduced by Krause and then modified by Stein was adopted. On analysis of the data of this series it was observed that in 25% of the cases completely benign resectable tumours were found; in 25% of the cases astrocytoma (grade I-II) which could be treated at least by partial removal were present; in 30% of the cases radiosensitive lesions were encountered. In the remaining 20% of the cases highly malignant tumours were found which should be treated only by radiotherapy and/or chemotherapy.

  7. MRI characteristics of midbrain tumours

    Sun, B.; Wang, C.C.; Wang, J.

    1999-01-01

    We diagnosed 60 cases of midbrain tumours by MRI between 1993 to 1997. There were 39 males and 21 females, aged 2-64 years, mean 25.6 years. We found 38 patients with true intramedullary midbrain tumours, 11 predominantly in the tectum, 20 in the tegmentum and 7 with a downward extension to the pons; there were 7 within the cerebral aqueduct. There were 22 patients with infiltrating midbrain tumours extending from adjacent structures, 11 cases each from the thalamus and pineal region. All patients received surgical treatment. Gross total resection was achieved in 42 cases, subtotal (> 75 %) resection in 18. Pathological diagnoses included 16 low-grade and 15 high-grade astrocytomas; 5 oligodendroastrocytomas; 2 ependymomas; 11 glioblastomas; and 11 pineal parenchymal or germ-cell tumours. Midbrain tumours are a heterogeneous group of neoplasms, with wide variation in clinical and MRI features, related to the site and type of tumour. MRI not only allows precise analysis of their growth pattern, but also can lead to a correct preoperative diagnosis in the majority of cases. (orig.) (orig.)

  8. Expression of manganese superoxide dismutase in rat blood, heart and brain during induced systemic hypoxia

    Septelia I. Wanandi

    2011-02-01

    Full Text Available Background: Hypoxia results in an increased generation of ROS. Until now, little is known about the role of MnSOD - a major endogenous antioxidant enzyme - on the cell adaptation response against hypoxia. The aim of this study was to  determine the MnSOD mRNA expression and levels of specific activity in blood, heart and brain of rats during induced systemic hypoxia.Methods: Twenty-five male Sprague Dawley rats were subjected to systemic hypoxia in an hypoxic chamber (at 8-10% O2 for 0, 1, 7, 14 and 21 days, respectively. The mRNA relative expression of MnSOD was analyzed using Real Time RT-PCR. MnSOD specific activity was determined using xanthine oxidase inhibition assay.Results: The MnSOD mRNA relative expression in rat blood and heart was decreased during early induced systemic hypoxia (day 1 and increased as hypoxia continued, whereas the mRNA expression in brain was increased since day 1 and reached its maximum level at day 7. The result of MnSOD specific activity during early systemic hypoxia was similar to the mRNA expression. Under very late hypoxic condition (day 21, MnSOD specific activity in blood, heart and brain was significantly decreased. We demonstrate a positive correlation between MnSOD mRNA expression and specific activity in these 3 tissues during day 0-14 of induced systemic hypoxia. Furthermore, mRNA expression and specific activity levels in heart strongly correlate with those in blood.Conclusion: The MnSOD expression at early and late phases of induced systemic hypoxia is distinctly regulated. The MnSOD expression in brain differs from that in blood and heart revealing that brain tissue can  possibly survive better from induced systemic hypoxia than heart and blood. The determination of MnSOD expression in blood can be used to describe its expression in heart under systemic hypoxic condition. (Med J Indones 2011; 20:27-33Keywords: MnSOD, mRNA expression, ROS, specific activity, systemic hypoxia

  9. In vivo Identification and Specificity assessment of mRNA markers of hypoxia in human and mouse tumors

    Busk, Morten; Toustrup, Kasper; Sørensen, Brita S; Alsner, Jan; Horsman, Michael R; Jakobsen, Steen; Overgaard, Jens

    2011-01-01

    Tumor hypoxia is linked to poor prognosis, but identification and quantification of tissue hypoxia remains a challenge. The hypoxia-specificity of HIF-1α target genes in vivo has been questioned due to the confounding influence of other microenvironmental abnormalities known to affect gene expression (e.g., low pH). Here we describe a new technique that by exploiting intratumoral oxygenation heterogeneity allows us to identify and objectively rank the most robust mRNA hypoxia biomarkers. Mice carrying human (FaDu dd ) or murine (SCCVII) tumors were injected with the PET hypoxia tracer FAZA. Four hours post-injection tumors were removed, frozen, and crushed into milligram-sized fragments, which were transferred individually to pre-weighed tubes containing RNAlater and then weighed. For each fragment radioactivity per tissue mass and expression patterns of selected mRNA biomarkers were analyzed and compared. In both tumour models, fragmentation into pieces weighing 10 to 60 mg resulted in tissue fragments with highly variable relative content of hypoxic cells as evidenced by an up to 13-fold variation in FAZA radioactivity per mass of tissue. Linear regression analysis comparing FAZA retention with patterns of gene expression in individual tissue fragments revealed that CA9, GLUT1 and LOX mRNA levels were equally and strongly correlated to hypoxic extent in FaDu dd . The same link between hypoxia and gene expression profile was observed for CA9 and GLUT1, but not LOX, in SCCVII tumors. Apparent in vivo hypoxia-specificity for other putative molecular markers of tissue hypoxia was considerably weaker. The portrayed technique allows multiple pairwise measurements of mRNA transcript levels and extent of hypoxia in individual tumors at a smallest possible volumetric scale which (by limiting averaging effects inherent to whole-tumor analysis) strengthen the conclusiveness on true hypoxia-specificity of candidate genes while limiting the required number of tumors. Among

  10. In vivo Identification and Specificity assessment of mRNA markers of hypoxia in human and mouse tumors

    Horsman Michael R

    2011-02-01

    Full Text Available Abstract Background Tumor hypoxia is linked to poor prognosis, but identification and quantification of tissue hypoxia remains a challenge. The hypoxia-specificity of HIF-1α target genes in vivo has been questioned due to the confounding influence of other microenvironmental abnormalities known to affect gene expression (e.g., low pH. Here we describe a new technique that by exploiting intratumoral oxygenation heterogeneity allows us to identify and objectively rank the most robust mRNA hypoxia biomarkers. Methods Mice carrying human (FaDudd or murine (SCCVII tumors were injected with the PET hypoxia tracer FAZA. Four hours post-injection tumors were removed, frozen, and crushed into milligram-sized fragments, which were transferred individually to pre-weighed tubes containing RNAlater and then weighed. For each fragment radioactivity per tissue mass and expression patterns of selected mRNA biomarkers were analyzed and compared. Results In both tumour models, fragmentation into pieces weighing 10 to 60 mg resulted in tissue fragments with highly variable relative content of hypoxic cells as evidenced by an up to 13-fold variation in FAZA radioactivity per mass of tissue. Linear regression analysis comparing FAZA retention with patterns of gene expression in individual tissue fragments revealed that CA9, GLUT1 and LOX mRNA levels were equally and strongly correlated to hypoxic extent in FaDudd. The same link between hypoxia and gene expression profile was observed for CA9 and GLUT1, but not LOX, in SCCVII tumors. Apparent in vivo hypoxia-specificity for other putative molecular markers of tissue hypoxia was considerably weaker. Conclusions The portrayed technique allows multiple pairwise measurements of mRNA transcript levels and extent of hypoxia in individual tumors at a smallest possible volumetric scale which (by limiting averaging effects inherent to whole-tumor analysis strengthen the conclusiveness on true hypoxia-specificity of candidate

  11. Ursodeoxycholic acid protects cardiomyocytes against cobalt chloride induced hypoxia by regulating transcriptional mediator of cells stress hypoxia inducible factor 1α and p53 protein.

    Mohamed, Anis Syamimi; Hanafi, Noorul Izzati; Sheikh Abdul Kadir, Siti Hamimah; Md Noor, Julina; Abdul Hamid Hasani, Narimah; Ab Rahim, Sharaniza; Siran, Rosfaiizah

    2017-10-01

    In hepatocytes, ursodeoxycholic acid (UDCA) activates cell signalling pathways such as p53, intracellular calcium ([Ca 2+ ] i ), and sphingosine-1-phosphate (S1P)-receptor via Gα i -coupled-receptor. Recently, UDCA has been shown to protect the heart against hypoxia-reoxygenation injury. However, it is not clear whether UDCA cardioprotection against hypoxia acts through a transcriptional mediator of cells stress, HIF-1α and p53. Therefore, in here, we aimed to investigate whether UDCA could protect cardiomyocytes (CMs) against hypoxia by regulating expression of HIF-1α, p53, [Ca 2+ ] i , and S1P-Gα i -coupled-receptor. Cardiomyocytes were isolated from newborn rats (0-2 days), and hypoxia was induced by using cobalt chloride (CoCl 2 ). Cardiomyocytes were treated with UDCA and cotreated with either FTY720 (S1P-receptor agonist) or pertussis toxin (PTX; Gα i inhibitor). Cells were subjected for proliferation assay, beating frequency, QuantiGene Plex assay, western blot, immunofluorescence, and calcium imaging. Our findings showed that UDCA counteracted the effects of CoCl 2 on cell viability, beating frequency, HIF-1α, and p53 protein expression. We found that these cardioprotection effects of UDCA were similar to FTY720, S1P agonist. Furthermore, we observed that UDCA protects CMs against CoCl 2 -induced [Ca 2+ ] i dynamic alteration. Pharmacological inhibition of the Gα i -sensitive receptor did not abolish the cardioprotection of UDCA against CoCl 2 detrimental effects, except for cell viability and [Ca 2+ ] i . Pertussis toxin is partially effective in inhibiting UDCA protection against CoCl 2 effects on CM cell viability. Interestingly, PTX fully inhibits UDCA cardioprotection on CoCl 2 -induced [Ca 2+ ] i dynamic changes. We conclude that UDCA cardioprotection against CoCl 2 -induced hypoxia is similar to FTY720, and its actions are not fully mediated by the Gα i -coupled protein sensitive pathways. Ursodeoxycholic acid is the most hydrophilic bile

  12. Radioiodinated 2-nitrobenzyl carbamates as bioreductive alkylating agents for tissue hypoxia

    Cuthbert, P.A.; Wearring, A.V.; Chamberlain, M.J.; Hunter, D.H.

    1993-01-01

    Three N-methylcarbamates of iodonitrobenzyl alcohols (4-iodo-2-nitrobenzyl alcohol 2, 5-iodo-2-nitrobenzyl alcohol 3 and 4-iodo-2,6-dinitrobenzyl alcohol 4) bearing [ 125 I] have been prepared and characterized for their lipophilicity, their reduction potentials and the in vivo lability of the radioiodine in healthy mice. Based upon these results, 2 and 4 were tested in tumor-bearing mice showing limited uptake of radioactivity in tumours and a tumor-to-blood ratio of less than 1. Consequently these particular carbamates are not satisfactory as hypoxia imaging agents. (author)

  13. The Askin tumour. Neuroactodermic tumour of the thoracic wall

    Velazquez, P.; Nicolas, A. I.; Vivas, I.; Damaso Aquerreta, J.; Martinez-Cuesta, A.

    1999-01-01

    The Askin tumours is an extremely rare and malignant process in the thoracic pulmonary region during infancy and youth. The differential diagnosis has to be considered with other thoracic wall tumours that are more common in pediatrics like the undifferentiated neuroblastoma, the embionic rabdomiosarcoma, the Ewing sarcoma and the linfoma. A retrospective examination was carried out on 473 thoracic wall tumours from 1994 to 1997 at our centre, resulting in 4 patients with an anatomopathologically tested Askin tumour (ages from 13-21). All the cases were studied using simple radiography and CT. In two cases MRI was also used. The most common clinical manifestation was a palpable painful mass in the thoracic wall. In the simple radiograph the main finding was a large mass of extrapleural soft material, with costal destruction ( n=3) and a pleural effusion (n=2). In the CT study the mass was heterogeneous, with internal calcifications in one case. CT and MRI showed invasion in the mediastinum (n=1), medular channel (n=1) and phrenic and sulphrenic extension (n=1). The Askin tumour should be included in the differential diagnosis of thoracic wall masses in infant-youth ages. There are no specific morphological characteristics. Both CT and MRI are useful for the diagnosis, staging and follow up. (Author) 11 refs

  14. The tyrosine phosphatase SHP-1 regulates hypoxia inducible factor-1α (HIF-1α protein levels in endothelial cells under hypoxia.

    Stefan K Alig

    Full Text Available The tyrosine phosphatase SHP-1 negatively influences endothelial function, such as VEGF signaling and reactive oxygen species (ROS formation, and has been shown to influence angiogenesis during tissue ischemia. In ischemic tissues, hypoxia induced angiogenesis is crucial for restoring oxygen supply. However, the exact mechanism how SHP-1 affects endothelial function during ischemia or hypoxia remains unclear. We performed in vitro endothelial cell culture experiments to characterize the role of SHP-1 during hypoxia.SHP-1 knock-down by specific antisense oligodesoxynucleotides (AS-Odn increased cell growth as well as VEGF synthesis and secretion during 24 hours of hypoxia compared to control AS-Odn. This was prevented by HIF-1α inhibition (echinomycin and apigenin. SHP-1 knock-down as well as overexpression of a catalytically inactive SHP-1 (SHP-1 CS further enhanced HIF-1α protein levels, whereas overexpression of a constitutively active SHP-1 (SHP-1 E74A resulted in decreased HIF-1α levels during hypoxia, compared to wildtype SHP-1. Proteasome inhibition (MG132 returned HIF-1α levels to control or wildtype levels respectively in these cells. SHP-1 silencing did not alter HIF-1α mRNA levels. Finally, under hypoxic conditions SHP-1 knock-down enhanced intracellular endothelial reactive oxygen species (ROS formation, as measured by oxidation of H2-DCF and DHE fluorescence.SHP-1 decreases half-life of HIF-1α under hypoxic conditions resulting in decreased cell growth due to diminished VEGF synthesis and secretion. The regulatory effect of SHP-1 on HIF-1α stability may be mediated by inhibition of endothelial ROS formation stabilizing HIF-1α protein. These findings highlight the importance of SHP-1 in hypoxic signaling and its potential as therapeutic target in ischemic diseases.

  15. Nutrient-Deprived Retinal Progenitors Proliferate in Response to Hypoxia: Interaction of the HIF-1 and mTOR Pathway

    Helena Khaliullina

    2016-05-01

    Full Text Available At a cellular level, nutrients are sensed by the mechanistic Target of Rapamycin (mTOR. The response of cells to hypoxia is regulated via action of the oxygen sensor Hypoxia-Inducible Factor 1 (HIF-1. During development, injury and disease, tissues might face conditions of both low nutrient supply and low oxygen, yet it is not clear how cells adapt to both nutrient restriction and hypoxia, or how mTOR and HIF-1 interact in such conditions. Here we explore this question in vivo with respect to cell proliferation using the ciliary marginal zone (CMZ of Xenopus. We found that both nutrient-deprivation and hypoxia cause retinal progenitors to decrease their proliferation, yet when nutrient-deprived progenitors are exposed to hypoxia there is an unexpected rise in cell proliferation. This increase, mediated by HIF-1 signalling, is dependent on glutaminolysis and reactivation of the mTOR pathway. We discuss how these findings in non-transformed tissue may also shed light on the ability of cancer cells in poorly vascularised solid tumours to proliferate.

  16. Childhood Adrenocortical Tumours: a Review

    Marques-Pereira Rosana

    2006-05-01

    Full Text Available Abstract Childhood adrenocortical tumour (ACT is not a common disease, but in southern Brazil the prevalence is 15 times higher than in other parts of the world. One hundred and thirty-seven patients have been identified and followed by our group over the past four decades. Affected children are predominantly girls, with a female-to-male ratio of 3.5:1 in patients below 4 years of age. Virilization alone (51.6% or mixed with Cushing's syndrome (42.0% was the predominant clinical picture observed in these patients. Tumours are unilateral, affecting both glands equally. TP53 R337H germline mutations underlie most childhood ACTs in southern Brazil. Epidemiological data from our casuistic studies revealed that this mutation has ~10% penetrance for ACT. Surgery is the definitive treatment, and a complete resection should always be attempted. Although adjuvant chemotherapy has shown some encouraging results, its influence on overall outcome is small. The survival rate is directly correlated to tumour size; patients with small, completely excised tumours have survival rates close to 90%, whereas in those patients with inoperable tumours and/or metastatic disease it is less than 10%. In the group of patients with large, excisable tumours, half of them have an intermediate outcome. Recent molecular biology techniques and genomic approaches may help us to better understand the pathogenesis of ACT, the risk of developing a tumour when TP53 R337H is present, and to predict its outcome. An ongoing pilot study consisting of close monitoring of healthy carriers of the TP53 R337H mutation - siblings and first-degree relatives of known affected cases - aims at the early detection of ACTs and an improvement of the cure rate.

  17. Epigenetic control of hypoxia inducible factor-1α-dependent expression of placental growth factor in hypoxic conditions.

    Tudisco, Laura; Della Ragione, Floriana; Tarallo, Valeria; Apicella, Ivana; D'Esposito, Maurizio; Matarazzo, Maria Rosaria; De Falco, Sandro

    2014-04-01

    Hypoxia plays a crucial role in the angiogenic switch, modulating a large set of genes mainly through the activation of hypoxia-inducible factor (HIF) transcriptional complex. Endothelial cells play a central role in new vessels formation and express placental growth factor (PlGF), a member of vascular endothelial growth factor (VEGF) family, mainly involved in pathological angiogenesis. Despite several observations suggest a hypoxia-mediated positive modulation of PlGF, the molecular mechanism governing this regulation has not been fully elucidated. We decided to investigate if epigenetic modifications are involved in hypoxia-induced PlGF expression. We report that PlGF expression was induced in cultured human and mouse endothelial cells exposed to hypoxia (1% O 2), although DNA methylation at the Plgf CpG-island remains unchanged. Remarkably, robust hyperacetylation of histones H3 and H4 was observed in the second intron of Plgf, where hypoxia responsive elements (HREs), never described before, are located. HIF-1α, but not HIF-2α, binds to identified HREs. Noteworthy, only HIF-1α silencing fully inhibited PlGF upregulation. These results formally demonstrate a direct involvement of HIF-1α in the upregulation of PlGF expression in hypoxia through chromatin remodeling of HREs sites. Therefore, PlGF may be considered one of the putative targets of anti-HIF therapeutic applications.

  18. Saururus cernuus lignans-Potent small molecule inhibitors of hypoxia-inducible factor-1

    Hossain, Chowdhury Faiz; Kim, Yong-Pil; Baerson, Scott R.; Zhang Lei; Bruick, Richard K.; Mohammed, Kaleem A.; Agarwal, Ameeta K.; Nagle, Dale G.; Zhou Yudong

    2005-01-01

    Hypoxia-inducible factor-1 (HIF-1) represents an important tumor-selective therapeutic target for solid tumors. In search of novel small molecule HIF-1 inhibitors, 5400 natural product-rich extracts from plants, marine organisms, and microbes were examined for HIF-1 inhibitory activities using a cell-based reporter assay. Bioassay-guided fractionation and isolation, followed by structure elucidation, yielded three potent natural product-derived HIF-1 inhibitors and two structurally related inactive compounds. In a T47D cell-based reporter assay, manassantin B 1 , manassantin A, and 4-O-methylsaucerneol inhibited hypoxia-induced HIF-1 activation with IC 50 values of 3, 3, and 20 nM, respectively. All three compounds are relatively hypoxia-specific inhibitors of HIF-1 activation, in comparison to other stimuli. The hypoxic induction of HIF-1 target genes CDKN1A, VEGF, and GLUT-1 were also inhibited. These compounds inhibit HIF-1 by blocking hypoxia-induced nuclear HIF-1α protein accumulation without affecting HIF-1α mRNA levels. In addition, preliminary structure-activity studies suggest specific structural requirements for this class of HIF-1 inhibitors

  19. Cancer cell-associated cytoplasmic B7–H4 is induced by hypoxia through hypoxia-inducible factor-1α and promotes cancer cell proliferation

    Jeon, You-Kyoung [Department of Microbiology and Immunology, Inje University College of Medicine, Busan 614-735 (Korea, Republic of); Advanced Research Center for Multiple Myeloma, Inje University College of Medicine, Busan 614-735 (Korea, Republic of); Park, Sae-Gwang; Choi, Il-Whan [Department of Microbiology and Immunology, Inje University College of Medicine, Busan 614-735 (Korea, Republic of); Lee, Soo-Woong [Advanced Research Center for Multiple Myeloma, Inje University College of Medicine, Busan 614-735 (Korea, Republic of); Lee, Sang Min [Department of Internal Medicine, Division of Hematology/Oncology, Busan Paik Hospital, Inje University, Busan 614-735 (Korea, Republic of); Choi, Inhak, E-mail: miccih@inje.ac.kr [Department of Microbiology and Immunology, Inje University College of Medicine, Busan 614-735 (Korea, Republic of); Advanced Research Center for Multiple Myeloma, Inje University College of Medicine, Busan 614-735 (Korea, Republic of)

    2015-04-03

    Aberrant B7–H4 expression in cancer tissues serves as a novel prognostic biomarker for poor survival in patients with cancer. However, the factor(s) that induce cancer cell-associated B7–H4 remain to be fully elucidated. We herein demonstrate that hypoxia upregulates B7–H4 transcription in primary CD138{sup +} multiple myeloma cells and cancer cell lines. In support of this finding, analysis of the Multiple Myeloma Genomics Portal (MMGP) data set revealed a positive correlation between the mRNA expression levels of B7–H4 and the endogenous hypoxia marker carbonic anhydrogenase 9. Hypoxia-induced B7–H4 expression was detected in the cytoplasm, but not in cancer cell membranes. Chromatin immunoprecipitation analysis demonstrated binding of hypoxia-inducible factor-1α (HIF-1α) to proximal hypoxia-response element (HRE) sites within the B7–H4 promoter. Knockdown of HIF-1α and pharmacological inhibition of HIF-1α diminished B7–H4 expression. Furthermore, knockdown of cytoplasmic B7–H4 in MCF-7 decreased the S-phase cell population under hypoxia. Finally, MMGP analysis revealed a positive correlation between the transcript levels of B7–H4 and proliferation-related genes including MKI67, CCNA1, and Myc in several patients with multiple myeloma. Our results provide insight into the mechanisms underlying B7–H4 upregulation and its role in cancer cell proliferation in a hypoxic tumor microenvironment. - Highlights: • Hypoxia upregulates B7–H4 transcription and protein expression. • Hypoxia-induced B7–H4 is detected in the cytoplasm, but not on membrane. • ChIP assay reveals a binding of HIF-1α to B7–H4 promoter at HRE site. • Knockdown and pharmacological inhibition of HIF-1α reduce B7–H4 expression. • B7–H4 knockdown decrease the number of cells in S-phase of cell cycle.

  20. Imaging in unilateral Wilms tumour

    Brisse, Herve J.; Smets, Anne M.; Kaste, Sue C.; Owens, Catherine M.

    2008-01-01

    Wilms tumour is one of the most common malignancies in children, with an excellent prognosis after therapy. There is a very diverse approach to treatment according to geographical location. This variation in therapeutic attitude toward Wilms tumour, particularly between the United States and Europe, has consequences for the choice of imaging modality at diagnosis. In Europe, the International Society of Paediatric Oncology (SIOP) treatment protocol is based on chemotherapy followed by surgery. Imaging (US, CT and MRI), clinical history and examination will help predict whether the findings are consistent with Wilms tumour. Furthermore, in the UK preoperative image-guided biopsy is advised to help identify the small group of patients who, despite typical imaging features of Wilms tumour, have other types of neoplasia that require alternative management. In the United States, the National Wilms Tumor Study (NWTS) advises surgery prior to chemo- and radiotherapy. Hence imaging must provide detailed anatomical information for surgical planning. This article discusses the role of imaging at diagnosis and the relative strengths and weaknesses of the available radiological techniques. We also focus on imaging the lung for metastatic disease and the consequences (to the patient's ultimate outcome) of CT-diagnosed small pulmonary nodules and discuss the radiological diagnosis and consequences of tumour rupture present at diagnosis. (orig.)

  1. Prolactin, TNF alpha and nitric oxide expression in nitroso-N-methylurea-induced-mammary tumours

    Vegh Irene

    2007-11-01

    Full Text Available Abstract Background The N-Nitrosomethylurea breast cancer model induced in rats is used for the study of carcinogenesis in mammary cancer, prostate, pancreas, etc. This model is very similar to human neoplastic disease. Methods The present experimental study was designed to assess whether metoclopramide administration has any effect on development of MNU-induced tumours, and evaluate the treatment of goserelin acetate on PRL, TNF alpha and NO expression. NMU was administered to female Wistar rats on 2 occasions (5 mg/100 g body w/rat. PRL and TNF alpha were performed by immune-assay. Nitric Oxide by semi automated-assay and ploidy analyses by flow cytometry. Results The administration of metoclopramide made the induction time shorter and increased the incidence and average of tumours per rat. Tumours development was inhibited by a goserelin chronic administration. The ploidy of adenocarcinoma was polyploid-aneuploid type (average S = 60%. It was higher basal PRL plasma levels in rats with NMU induced tumours than in basal controls without tumour (p Conclusion The increase of blood PRL levels in NMU-induced rats may be an indicator of a poor prognosis of mammary cancer evolution. The metoclopramide administration accelerates tumour growth. However goserelin administration achieves regression in tumour development associated to inhibition PRL, TNF alpha and NO expression.

  2. Lack of prognostic and predictive value of CA IX in radiotherapy of squamous cell carcinoma of the head and neck with known modifiable hypoxia: An evaluation of the DAHANCA 5 study

    Eriksen, Jesper Grau; Overgaard, Jens

    2007-01-01

    BACKGROUND AND PURPOSE: CA IX is suggested to be an endogenous marker of hypoxia in tumours like squamous cell carcinomas of the head and neck (HNSCC). The aim of the present study was to investigate whether CA IX served as a prognostic factor for outcome in a large population of HNSCC and if CA IX...... was able to discriminate the tumours that did benefit from hypoxic modification with nimorazole. MATERIALS AND METHODS: Paraffin-embedded formalin-fixed pre-treatment tumour tissue was available from 320 of the 414 patients treated in the randomized DAHANCA 5 protocol with primary radiotherapy...

  3. Whole-genome landscape of pancreatic neuroendocrine tumours.

    Scarpa, Aldo; Chang, David K; Nones, Katia; Corbo, Vincenzo; Patch, Ann-Marie; Bailey, Peter; Lawlor, Rita T; Johns, Amber L; Miller, David K; Mafficini, Andrea; Rusev, Borislav; Scardoni, Maria; Antonello, Davide; Barbi, Stefano; Sikora, Katarzyna O; Cingarlini, Sara; Vicentini, Caterina; McKay, Skye; Quinn, Michael C J; Bruxner, Timothy J C; Christ, Angelika N; Harliwong, Ivon; Idrisoglu, Senel; McLean, Suzanne; Nourse, Craig; Nourbakhsh, Ehsan; Wilson, Peter J; Anderson, Matthew J; Fink, J Lynn; Newell, Felicity; Waddell, Nick; Holmes, Oliver; Kazakoff, Stephen H; Leonard, Conrad; Wood, Scott; Xu, Qinying; Nagaraj, Shivashankar Hiriyur; Amato, Eliana; Dalai, Irene; Bersani, Samantha; Cataldo, Ivana; Dei Tos, Angelo P; Capelli, Paola; Davì, Maria Vittoria; Landoni, Luca; Malpaga, Anna; Miotto, Marco; Whitehall, Vicki L J; Leggett, Barbara A; Harris, Janelle L; Harris, Jonathan; Jones, Marc D; Humphris, Jeremy; Chantrill, Lorraine A; Chin, Venessa; Nagrial, Adnan M; Pajic, Marina; Scarlett, Christopher J; Pinho, Andreia; Rooman, Ilse; Toon, Christopher; Wu, Jianmin; Pinese, Mark; Cowley, Mark; Barbour, Andrew; Mawson, Amanda; Humphrey, Emily S; Colvin, Emily K; Chou, Angela; Lovell, Jessica A; Jamieson, Nigel B; Duthie, Fraser; Gingras, Marie-Claude; Fisher, William E; Dagg, Rebecca A; Lau, Loretta M S; Lee, Michael; Pickett, Hilda A; Reddel, Roger R; Samra, Jaswinder S; Kench, James G; Merrett, Neil D; Epari, Krishna; Nguyen, Nam Q; Zeps, Nikolajs; Falconi, Massimo; Simbolo, Michele; Butturini, Giovanni; Van Buren, George; Partelli, Stefano; Fassan, Matteo; Khanna, Kum Kum; Gill, Anthony J; Wheeler, David A; Gibbs, Richard A; Musgrove, Elizabeth A; Bassi, Claudio; Tortora, Giampaolo; Pederzoli, Paolo; Pearson, John V; Waddell, Nicola; Biankin, Andrew V; Grimmond, Sean M

    2017-03-02

    The diagnosis of pancreatic neuroendocrine tumours (PanNETs) is increasing owing to more sensitive detection methods, and this increase is creating challenges for clinical management. We performed whole-genome sequencing of 102 primary PanNETs and defined the genomic events that characterize their pathogenesis. Here we describe the mutational signatures they harbour, including a deficiency in G:C > T:A base excision repair due to inactivation of MUTYH, which encodes a DNA glycosylase. Clinically sporadic PanNETs contain a larger-than-expected proportion of germline mutations, including previously unreported mutations in the DNA repair genes MUTYH, CHEK2 and BRCA2. Together with mutations in MEN1 and VHL, these mutations occur in 17% of patients. Somatic mutations, including point mutations and gene fusions, were commonly found in genes involved in four main pathways: chromatin remodelling, DNA damage repair, activation of mTOR signalling (including previously undescribed EWSR1 gene fusions), and telomere maintenance. In addition, our gene expression analyses identified a subgroup of tumours associated with hypoxia and HIF signalling.

  4. The anti-proliferative effect of L-carnosine correlates with a decreased expression of hypoxia inducible factor 1 alpha in human colon cancer cells.

    Barbara Iovine

    Full Text Available In recent years considerable attention has been given to the use of natural substances as anticancer drugs. The natural antioxidant dipeptide L-carnosine belongs to this class of molecules because it has been proved to have a significant anticancer activity both in vitro and in vivo. Previous studies have shown that L-carnosine inhibits the proliferation of human colorectal carcinoma cells by affecting the ATP and Reactive Oxygen Species (ROS production. In the present study we identified the Hypoxia-Inducible Factor 1α (HIF-1α as a possible target of L-carnosine in HCT-116 cell line. HIF-1α protein is over-expressed in multiple types of human cancer and is the major cause of resistance to drugs and radiation in solid tumours. Of particular interest are experimental data supporting the concept that generation of ROS provides a redox signal for HIF-1α induction, and it is known that some antioxidants are able to suppress tumorigenesis by inhibiting HIF-1α. In the current study we found that L-carnosine reduces the HIF-1α protein level affecting its stability and decreases the HIF-1 transcriptional activity. In addition, we demonstrated that L-carnosine is involved in ubiquitin-proteasome system promoting HIF-1α degradation. Finally, we compared the antioxidant activity of L-carnosine with that of two synthetic anti-oxidant bis-diaminotriazoles (namely 1 and 2, respectively. Despite these three compounds have the same ability in reducing intracellular ROS, 1 and 2 are more potent scavengers and have no effect on HIF-1α expression and cancer cell proliferation. These findings suggest that an analysis of L-carnosine antioxidant pathway will clarify the mechanism underlying the anti-proliferative effects of this dipeptide on colon cancer cells. However, although the molecular mechanism by which L-carnosine down regulates or inhibits the HIF-1α activity has not been yet elucidated, this ability may be promising in treating hypoxia

  5. Pitfalls in colour photography of choroidal tumours

    Schalenbourg, A; Zografos, L

    2013-01-01

    Colour imaging of fundus tumours has been transformed by the development of digital and confocal scanning laser photography. These advances provide numerous benefits, such as panoramic images, increased contrast, non-contact wide-angle imaging, non-mydriatic photography, and simultaneous angiography. False tumour colour representation can, however, cause serious diagnostic errors. Large choroidal tumours can be totally invisible on angiography. Pseudogrowth can occur because of artefacts caused by different methods of fundus illumination, movement of reference blood vessels, and flattening of Bruch's membrane and sclera when tumour regression occurs. Awareness of these pitfalls should prevent the clinician from misdiagnosing tumours and wrongfully concluding that a tumour has grown. PMID:23238442

  6. Pitfalls in colour photography of choroidal tumours.

    Schalenbourg, A; Zografos, L

    2013-02-01

    Colour imaging of fundus tumours has been transformed by the development of digital and confocal scanning laser photography. These advances provide numerous benefits, such as panoramic images, increased contrast, non-contact wide-angle imaging, non-mydriatic photography, and simultaneous angiography. False tumour colour representation can, however, cause serious diagnostic errors. Large choroidal tumours can be totally invisible on angiography. Pseudogrowth can occur because of artefacts caused by different methods of fundus illumination, movement of reference blood vessels, and flattening of Bruch's membrane and sclera when tumour regression occurs. Awareness of these pitfalls should prevent the clinician from misdiagnosing tumours and wrongfully concluding that a tumour has grown.

  7. Regulation of human skeletal muscle perfusion and its heterogeneity during exercise in moderate hypoxia

    Heinonen, Ilkka H; Kemppainen, Jukka; Kaskinoro, Kimmo

    2010-01-01

    , the results show that increased BF during one-leg exercise in moderate hypoxia is confined only to the contracting muscles, and the working muscle hyperemia appears not to be directly mediated by adenosine. Increased flow heterogeneity in noncontracting muscles likely reflects sympathetic nervous constraints...... healthy young men using positron emission tomography during one-leg dynamic knee extension exercise in normoxia and moderate physiological systemic hypoxia (14% O(2) corresponding to approximately 3,400 m of altitude) without and with local adenosine receptor inhibition with femoral artery infusion...... to curtail BF increments in areas other than working skeletal muscles, but this effect is not potentiated in moderate systemic hypoxia during small muscle mass exercise....

  8. Novel somatic and germline mutations in intracranial germ cell tumours.

    Wang, Linghua; Yamaguchi, Shigeru; Burstein, Matthew D; Terashima, Keita; Chang, Kyle; Ng, Ho-Keung; Nakamura, Hideo; He, Zongxiao; Doddapaneni, Harshavardhan; Lewis, Lora; Wang, Mark; Suzuki, Tomonari; Nishikawa, Ryo; Natsume, Atsushi; Terasaka, Shunsuke; Dauser, Robert; Whitehead, William; Adekunle, Adesina; Sun, Jiayi; Qiao, Yi; Marth, Gábor; Muzny, Donna M; Gibbs, Richard A; Leal, Suzanne M; Wheeler, David A; Lau, Ching C

    2014-07-10

    Intracranial germ cell tumours (IGCTs) are a group of rare heterogeneous brain tumours that are clinically and histologically similar to the more common gonadal GCTs. IGCTs show great variation in their geographical and gender distribution, histological composition and treatment outcomes. The incidence of IGCTs is historically five- to eightfold greater in Japan and other East Asian countries than in Western countries, with peak incidence near the time of puberty. About half of the tumours are located in the pineal region. The male-to-female incidence ratio is approximately 3-4:1 overall, but is even higher for tumours located in the pineal region. Owing to the scarcity of tumour specimens available for research, little is currently known about this rare disease. Here we report the analysis of 62 cases by next-generation sequencing, single nucleotide polymorphism array and expression array. We find the KIT/RAS signalling pathway frequently mutated in more than 50% of IGCTs, including novel recurrent somatic mutations in KIT, its downstream mediators KRAS and NRAS, and its negative regulator CBL. Novel somatic alterations in the AKT/mTOR pathway included copy number gains of the AKT1 locus at 14q32.33 in 19% of patients, with corresponding upregulation of AKT1 expression. We identified loss-of-function mutations in BCORL1, a transcriptional co-repressor and tumour suppressor. We report significant enrichment of novel and rare germline variants in JMJD1C, which codes for a histone demethylase and is a coactivator of the androgen receptor, among Japanese IGCT patients. This study establishes a molecular foundation for understanding the biology of IGCTs and suggests potentially promising therapeutic strategies focusing on the inhibition of KIT/RAS activation and the AKT1/mTOR pathway.

  9. The Clinical Importance of Assessing Tumor Hypoxia: Relationship of Tumor Hypoxia to Prognosis and Therapeutic Opportunities

    Walsh, Joseph C.; Lebedev, Artem; Aten, Edward; Madsen, Kathleen; Marciano, Liane

    2014-01-01

    I. Introduction II. The Clinical Importance of Tumor Hypoxia A. Pathophysiology of hypoxia B. Hypoxia's negative impact on the effectiveness of curative treatment 1. Hypoxic tumors accumulate and propagate cancer stem cells 2. Hypoxia reduces the effectiveness of radiotherapy 3. Hypoxia increases metastasis risk and reduces the effectiveness of surgery 4. Hypoxic tumors are resistant to the effects of chemotherapy and chemoradiation C. Hypoxia is prognostic for poor patient outcomes III. Diagnosis of Tumor Hypoxia A. Direct methods 1. Oxygen electrode—direct pO2 measurement most used in cancer research 2. Phosphorescence quenching—alternative direct pO2 measurement 3. Electron paramagnetic resonance 4. 19F-magnetic resonance spectroscopy 5. Overhauser-enhanced MRI B. Endogenous markers of hypoxia 1. Hypoxia-inducible factor-1α 2. Carbonic anhydrase IX 3. Glucose transporter 1 4. Osteopontin 5. A combined IHC panel of protein markers for hypoxia 6. Comet assay C. Physiologic methods 1. Near-infrared spectroscopy/tomography—widely used for pulse oximetry 2. Photoacoustic tomography 3. Contrast-enhanced color duplex sonography 4. MRI-based measurements 5. Blood oxygen level-dependent MRI 6. Pimonidazole 7. EF5 (pentafluorinated etanidazole) 8. Hypoxia PET imaging—physiologic hypoxia measurement providing tomographic information a. 18F-fluoromisonidazole b. 18F-fluoroazomycinarabinofuranoside c. 18F-EF5 (pentafluorinated etanidazole) d. 18F-flortanidazole e. Copper (II) (diacetyl-bis (N4-methylthiosemicarbazone)) f. 18F-FDG imaging of hypoxia IV. Modifying Hypoxia to Improve Therapeutic Outcomes A. Use of hypoxia information in radiation therapy planning B. Use of hypoxia assessment for selection of patients responsive to nimorazole C. Use of hypoxia assessment for selection of patients responsive to tirapazamine D. Use of hypoxia assessment for selection of patients

  10. NFAT5 is activated by hypoxia: role in ischemia and reperfusion in the rat kidney.

    Sandra Villanueva

    Full Text Available The current hypothesis postulates that NFAT5 activation in the kidney's inner medulla is due to hypertonicity, resulting in cell protection. Additionally, the renal medulla is hypoxic (10-18 mmHg; however there is no information about the effect of hypoxia on NFAT5. Using in vivo and in vitro models, we evaluated the effect of reducing the partial pressure of oxygen (PO(2 on NFAT5 activity. We found that 1 Anoxia increased NFAT5 expression and nuclear translocation in primary cultures of IMCD cells from rat kidney. 2 Anoxia increased transcriptional activity and nuclear translocation of NFAT5 in HEK293 cells. 3 The dose-response curve demonstrated that HIF-1α peaked at 2.5% and NFAT5 at 1% of O(2. 4 At 2.5% of O(2, the time-course curve of hypoxia demonstrated earlier induction of HIF-1α gene expression than NFAT5. 5 siRNA knockdown of NFAT5 increased the hypoxia-induced cell death. 6 siRNA knockdown of HIF-1α did not affect the NFAT5 induction by hypoxia. Additionally, HIF-1α was still induced by hypoxia even when NFAT5 was knocked down. 7 NFAT5 and HIF-1α expression were increased in kidney (cortex and medulla from rats subjected to an experimental model of ischemia and reperfusion (I/R. 7 Experimental I/R increased the NFAT5-target gene aldose reductase (AR. 8 NFAT5 activators (ATM and PI3K were induced in vitro (HEK293 cells and in vivo (I/R kidneys with the same timing of NFAT5. 8 Wortmannin, which inhibits ATM and PI3K, reduces hypoxia-induced NFAT5 transcriptional activation in HEK293 cells. These results demonstrate for the first time that NFAT5 is induced by hypoxia and could be a protective factor against ischemic damage.

  11. Andrographolide protects mouse astrocytes against hypoxia injury by promoting autophagy and S100B expression

    Juan Du

    2018-04-01

    Full Text Available Andrographolide (ANDRO has been studied for its immunomodulation, anti-inflammatory, and neuroprotection effects. Because brain hypoxia is the most common factor of secondary brain injury after traumatic brain injury, we studied the role and possible mechanism of ANDRO in this process using hypoxia-injured astrocytes. Mouse cortical astrocytes C8-D1A (astrocyte type I clone from C57/BL6 strains were subjected to 3 and 21% of O2 for various times (0–12 h to establish an astrocyte hypoxia injury model in vitro. After hypoxia and ANDRO administration, the changes in cell viability and apoptosis were assessed using CCK-8 and flow cytometry. Expression changes in apoptosis-related proteins, autophagy-related proteins, main factors of JNK pathway, ATG5, and S100B were determined by western blot. Hypoxia remarkably damaged C8-D1A cells evidenced by reduction of cell viability and induction of apoptosis. Hypoxia also induced autophagy and overproduction of S100B. ANDRO reduced cell apoptosis and promoted cell autophagy and S100B expression. After ANDRO administration, autophagy-related proteins, S-100B, JNK pathway proteins, and ATG5 were all upregulated, while autophagy-related proteins and s100b were downregulated when the jnk pathway was inhibited or ATG5 was knocked down. ANDRO conferred a survival advantage to hypoxia-injured astrocytes by reducing cell apoptosis and promoting autophagy and s100b expression. Furthermore, the promotion of autophagy and s100b expression by ANDRO was via activation of jnk pathway and regulation of ATG5.

  12. Transcriptome sequencing of the naked mole rat (Heterocephalus glaber and identification of hypoxia tolerance genes

    Bang Xiao

    2017-12-01

    Full Text Available The naked mole rat (NMR; Heterocephalus glaber is a small rodent species found in regions of Kenya, Ethiopia and Somalia. It has a high tolerance for hypoxia and is thus considered one of the most important natural models for studying hypoxia tolerance mechanisms. The various mechanisms underlying the NMR's hypoxia tolerance are beginning to be understood at different levels of organization, and next-generation sequencing methods promise to expand this understanding to the level of gene expression. In this study, we examined the sequence and transcript abundance data of the muscle transcriptome of NMRs exposed to hypoxia using the Illumina HiSeq 2500 system to clarify the possible genomic adaptive responses to the hypoxic underground surroundings. The RNA-seq raw FastQ data were mapped against the NMR genome. We identified 2337 differentially expressed genes (DEGs by comparison of the hypoxic and control groups. Functional annotation of the DEGs by gene ontology (GO analysis revealed enrichment of hypoxia stress-related GO categories, including ‘biological regulation’, ‘cellular process’, ‘ion transport’ and ‘cell-cell signaling’. Enrichment of DEGs in signaling pathways was analyzed against the Kyoto Encyclopedia of Genes and Genomes (KEGG database to identify possible interactions between DEGs. The results revealed significant enrichment of DEGs in focal adhesion, the mitogen-activated protein kinase (MAPK signaling pathway and the glycine, serine and threonine metabolism pathway. Furthermore, inhibition of DEGs (STMN1, MAPK8IP1 and MAPK10 expression induced apoptosis and arrested cell growth in NMR fibroblasts following hypoxia. Thus, this global transcriptome analysis of NMRs can provide an important genetic resource for the study of hypoxia tolerance in mammals. Furthermore, the identified DEGs may provide important molecular targets for biomedical research into therapeutic strategies for stroke and cardiovascular diseases.

  13. Ecosystem impacts of hypoxia: thresholds of hypoxia and pathways to recovery

    Steckbauer, A; Duarte, C M; Vaquer-Sunyer, R; Carstensen, J; Conley, D J

    2011-01-01

    Coastal hypoxia is increasing in the global coastal zone, where it is recognized as a major threat to biota. Managerial efforts to prevent hypoxia and achieve recovery of ecosystems already affected by hypoxia are largely based on nutrient reduction plans. However, these managerial efforts need to be informed by predictions on the thresholds of hypoxia (i.e. the oxygen levels required to conserve biodiversity) as well as the timescales for the recovery of ecosystems already affected by hypoxia. The thresholds for hypoxia in coastal ecosystems are higher than previously thought and are not static, but regulated by local and global processes, being particularly sensitive to warming. The examination of recovery processes in a number of coastal areas managed for reducing nutrient inputs and, thus, hypoxia (Northern Adriatic; Black Sea; Baltic Sea; Delaware Bay; and Danish Coastal Areas) reveals that recovery timescales following the return to normal oxygen conditions are much longer than those of loss following the onset of hypoxia, and typically involve decadal timescales. The extended lag time for ecosystem recovery from hypoxia results in non-linear pathways of recovery due to hysteresis and the shift in baselines, affecting the oxygen thresholds for hypoxia through time.

  14. Pyruvate induces transient tumor hypoxia by enhancing mitochondrial oxygen consumption and potentiates the anti-tumor effect of a hypoxia-activated prodrug TH-302.

    Yoichi Takakusagi

    Full Text Available BACKGROUND: TH-302 is a hypoxia-activated prodrug (HAP of bromo isophosphoramide mustard that is selectively activated within hypoxic regions in solid tumors. Our recent study showed that intravenously administered bolus pyruvate can transiently induce hypoxia in tumors. We investigated the mechanism underlying the induction of transient hypoxia and the combination use of pyruvate to potentiate the anti-tumor effect of TH-302. METHODOLOGY/RESULTS: The hypoxia-dependent cytotoxicity of TH-302 was evaluated by a viability assay in murine SCCVII and human HT29 cells. Modulation in cellular oxygen consumption and in vivo tumor oxygenation by the pyruvate treatment was monitored by extracellular flux analysis and electron paramagnetic resonance (EPR oxygen imaging, respectively. The enhancement of the anti-tumor effect of TH-302 by pyruvate treatment was evaluated by monitoring the growth suppression of the tumor xenografts inoculated subcutaneously in mice. TH-302 preferentially inhibited the growth of both SCCVII and HT29 cells under hypoxic conditions (0.1% O2, with minimal effect under aerobic conditions (21% O2. Basal oxygen consumption rates increased after the pyruvate treatment in SCCVII cells in a concentration-dependent manner, suggesting that pyruvate enhances the mitochondrial respiration to consume excess cellular oxygen. In vivo EPR oxygen imaging showed that the intravenous administration of pyruvate globally induced the transient hypoxia 30 min after the injection in SCCVII and HT29 tumors at the size of 500-1500 mm(3. Pretreatment of SCCVII tumor bearing mice with pyruvate 30 min prior to TH-302 administration, initiated with small tumors (∼ 550 mm(3, significantly delayed tumor growth. CONCLUSIONS/SIGNIFICANCE: Our in vitro and in vivo studies showed that pyruvate induces transient hypoxia by enhancing mitochondrial oxygen consumption in tumor cells. TH-302 therapy can be potentiated by pyruvate pretreatment if started at the

  15. Pyruvate induces transient tumor hypoxia by enhancing mitochondrial oxygen consumption and potentiates the anti-tumor effect of a hypoxia-activated prodrug TH-302.

    Takakusagi, Yoichi; Matsumoto, Shingo; Saito, Keita; Matsuo, Masayuki; Kishimoto, Shun; Wojtkowiak, Jonathan W; DeGraff, William; Kesarwala, Aparna H; Choudhuri, Rajani; Devasahayam, Nallathamby; Subramanian, Sankaran; Munasinghe, Jeeva P; Gillies, Robert J; Mitchell, James B; Hart, Charles P; Krishna, Murali C

    2014-01-01

    TH-302 is a hypoxia-activated prodrug (HAP) of bromo isophosphoramide mustard that is selectively activated within hypoxic regions in solid tumors. Our recent study showed that intravenously administered bolus pyruvate can transiently induce hypoxia in tumors. We investigated the mechanism underlying the induction of transient hypoxia and the combination use of pyruvate to potentiate the anti-tumor effect of TH-302. The hypoxia-dependent cytotoxicity of TH-302 was evaluated by a viability assay in murine SCCVII and human HT29 cells. Modulation in cellular oxygen consumption and in vivo tumor oxygenation by the pyruvate treatment was monitored by extracellular flux analysis and electron paramagnetic resonance (EPR) oxygen imaging, respectively. The enhancement of the anti-tumor effect of TH-302 by pyruvate treatment was evaluated by monitoring the growth suppression of the tumor xenografts inoculated subcutaneously in mice. TH-302 preferentially inhibited the growth of both SCCVII and HT29 cells under hypoxic conditions (0.1% O2), with minimal effect under aerobic conditions (21% O2). Basal oxygen consumption rates increased after the pyruvate treatment in SCCVII cells in a concentration-dependent manner, suggesting that pyruvate enhances the mitochondrial respiration to consume excess cellular oxygen. In vivo EPR oxygen imaging showed that the intravenous administration of pyruvate globally induced the transient hypoxia 30 min after the injection in SCCVII and HT29 tumors at the size of 500-1500 mm(3). Pretreatment of SCCVII tumor bearing mice with pyruvate 30 min prior to TH-302 administration, initiated with small tumors (∼ 550 mm(3)), significantly delayed tumor growth. Our in vitro and in vivo studies showed that pyruvate induces transient hypoxia by enhancing mitochondrial oxygen consumption in tumor cells. TH-302 therapy can be potentiated by pyruvate pretreatment if started at the appropriate tumor size and oxygen concentration.

  16. Chronic intermittent hypoxia induces atherosclerosis via activation of adipose angiopoietin-like 4.

    Drager, Luciano F; Yao, Qiaoling; Hernandez, Karen L; Shin, Mi-Kyung; Bevans-Fonti, Shannon; Gay, Jason; Sussan, Thomas E; Jun, Jonathan C; Myers, Allen C; Olivecrona, Gunilla; Schwartz, Alan R; Halberg, Nils; Scherer, Philipp E; Semenza, Gregg L; Powell, David R; Polotsky, Vsevolod Y

    2013-07-15

    Obstructive sleep apnea is a risk factor for dyslipidemia and atherosclerosis, which have been attributed to chronic intermittent hypoxia (CIH). Intermittent hypoxia inhibits a key enzyme of lipoprotein clearance, lipoprotein lipase, and up-regulates a lipoprotein lipase inhibitor, angiopoietin-like 4 (Angptl4), in adipose tissue. The effects and mechanisms of Angptl4 up-regulation in sleep apnea are unknown. To examine whether CIH induces dyslipidemia and atherosclerosis by increasing adipose Angptl4 via hypoxia-inducible factor-1 (HIF-1). ApoE(-/-) mice were exposed to intermittent hypoxia or air for 4 weeks while being treated with Angptl4-neutralizing antibody or vehicle. In vehicle-treated mice, hypoxia increased adipose Angptl4 levels, inhibited adipose lipoprotein lipase, increased fasting levels of plasma triglycerides and very low density lipoprotein cholesterol, and increased the size of atherosclerotic plaques. The effects of CIH were abolished by the antibody. Hypoxia-induced increases in plasma fasting triglycerides and adipose Angptl4 were not observed in mice with germline heterozygosity for a HIF-1α knockout allele. Transgenic overexpression of HIF-1α in adipose tissue led to dyslipidemia and increased levels of adipose Angptl4. In cultured adipocytes, constitutive expression of HIF-1α increased Angptl4 levels, which was abolished by siRNA. Finally, in obese patients undergoing bariatric surgery, the severity of nocturnal hypoxemia predicted Angptl4 levels in subcutaneous adipose tissue. HIF-1-mediated increase in adipose Angptl4 and the ensuing lipoprotein lipase inactivation may contribute to atherosclerosis in patients with sleep apnea.

  17. Paeoniflorin prevents hypoxia-induced epithelial–mesenchymal transition in human breast cancer cells

    Zhou Z

    2016-04-01

    Full Text Available Zhenyu Zhou,1,* Shunchang Wang,1,* Caijuan Song,2 Zhuang Hu11Department of Thyroid and Breast, Huaihe Hospital, Henan University, Kaifeng, 2Department of Immunization Program, Zhengzhou Center for Disease Control and Prevention, Zhengzhou, People’s Republic of China*These authors contributed equally to this workAbstract: Paeoniflorin (PF is a monoterpene glycoside extracted from the root of Paeonia lactiflora Pall. Previous studies have demonstrated that PF inhibits the growth, invasion, and metastasis of tumors in vivo and in vitro. However, the effect of PF on hypoxia-induced epithelial–mesenchymal transition (EMT in breast cancer cells remains unknown. Therefore, the objective of this study was to investigate the effect of PF on hypoxia-induced EMT in breast cancer cells, as well as characterize the underlying mechanism. The results presented in this study demonstrate that PF blocks the migration and invasion of breast cancer cells by repressing EMT under hypoxic conditions. PF also significantly attenuated the hypoxia-induced increase in HIF-1α level. Furthermore, PF prevented hypoxia-induced expression of phosphorylated PI3K and Akt in MDA-MB-231 cells. In conclusion, PF prevented hypoxia-induced EMT in breast cancer cells by inhibiting HIF-1α expression via modulation of PI3K/Akt signaling pathway. This finding provides evidence that PF can serve as a therapeutic agent for the treatment of breast cancer.Keywords: paeoniflorin, breast cancer, hypoxia, epithelial–mesenchymal transition, PI3K/Akt signaling pathway

  18. Antioxidant Mechanism of Rutin on Hypoxia-Induced Pulmonary Arterial Cell Proliferation

    Qian Li

    2014-11-01

    Full Text Available Reactive oxygen species (ROS are involved in the pathologic process of pulmonary arterial hypertension as either mediators or inducers. Rutin is a type of flavonoid which exhibits significant scavenging properties on oxygen radicals both in vitro and in vivo. In this study, we proposed that rutin attenuated hypoxia-induced pulmonary artery smooth muscle cell (PASMC proliferation by scavenging ROS. Immunofluorescence data showed that rutin decreased the production of ROS, which was mainly generated through mitochondria and NADPH oxidase 4 (Nox4 in pulmonary artery endothelial cells (PAECs. Western blot results provided further evidence on rutin increasing expression of Nox4 and hypoxia-inducible factor-1α (HIF-1α. Moreover, cell cycle analysis by flow cytometry indicated that proliferation of PASMCs triggered by hypoxia was also repressed by rutin. However, N-acetyl-L-cysteine (NAC, a scavenger of ROS, abolished or diminished the capability of rutin in repressing hypoxia-induced cell proliferation. These data suggest that rutin shows a potential benefit against the development of hypoxic pulmonary arterial hypertension by inhibiting ROS, subsequently preventing hypoxia-induced PASMC proliferation.

  19. Translational control is a major contributor to hypoxia induced gene expression

    Beucken, Twan van den; Magagnin, Michael G.; Jutten, Barry; Seigneuric, Renaud; Lambin, Philippe; Koritzinsky, Marianne; Wouters, Bradly G.

    2011-01-01

    Background and purpose: Hypoxia is a common feature of solid tumors that is associated with an aggressive phenotype, resistance to therapy and poor prognosis. Major contributors to these adverse effects are the transcriptional program activated by the HIF family of transcription factors as well as the translational response mediated by PERK-dependent phosphorylation of eIF2α and inhibition of mTORC1 activity. In this study we determined the relative contribution of both transcriptional and translational responses to changes in hypoxia induced gene expression. Material and methods: Total and efficiently translated (polysomal) mRNA was isolated from DU145 prostate carcinoma cells that were exposed for up to 24 h of hypoxia ( 2 ). Changes in transcription and translation were assessed using affymetrix microarray technology. Results: Our data reveal an unexpectedly large contribution of translation control on both induced and repressed gene expression at all hypoxic time points, particularly during acute hypoxia (2-4 h). Gene ontology analysis revealed that gene classes like transcription and signal transduction are stimulated by translational control whereas expression of genes involved in cell growth and protein metabolism are repressed during hypoxic conditions by translational control. Conclusions: Our data indicate that translation influences gene expression during hypoxia on a scale comparable to that of transcription.

  20. Antioxidant mechanism of Rutin on hypoxia-induced pulmonary arterial cell proliferation.

    Li, Qian; Qiu, Yanli; Mao, Min; Lv, Jinying; Zhang, Lixin; Li, Shuzhen; Li, Xia; Zheng, Xiaodong

    2014-11-18

    Reactive oxygen species (ROS) are involved in the pathologic process of pulmonary arterial hypertension as either mediators or inducers. Rutin is a type of flavonoid which exhibits significant scavenging properties on oxygen radicals both in vitro and in vivo. In this study, we proposed that rutin attenuated hypoxia-induced pulmonary artery smooth muscle cell (PASMC) proliferation by scavenging ROS. Immunofluorescence data showed that rutin decreased the production of ROS, which was mainly generated through mitochondria and NADPH oxidase 4 (Nox4) in pulmonary artery endothelial cells (PAECs). Western blot results provided further evidence on rutin increasing expression of Nox4 and hypoxia-inducible factor-1α (HIF-1α). Moreover, cell cycle analysis by flow cytometry indicated that proliferation of PASMCs triggered by hypoxia was also repressed by rutin. However, N-acetyl-L-cysteine (NAC), a scavenger of ROS, abolished or diminished the capability of rutin in repressing hypoxia-induced cell proliferation. These data suggest that rutin shows a potential benefit against the development of hypoxic pulmonary arterial hypertension by inhibiting ROS, subsequently preventing hypoxia-induced PASMC proliferation.

  1. Hypoxia perturbs aryl hydrocarbon receptor signaling and CYP1A1 expression induced by PCB 126 in human skin and liver-derived cell lines

    Vorrink, Sabine U. [Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, IA (United States); Department of Radiation Oncology, The University of Iowa, Iowa City, IA (United States); Severson, Paul L. [Department of Pharmacology and Toxicology, The University of Arizona, Tucson, AZ (United States); Kulak, Mikhail V. [Department of Surgery, The University of Iowa, Iowa City, IA (United States); Futscher, Bernard W. [Department of Pharmacology and Toxicology, The University of Arizona, Tucson, AZ (United States); Domann, Frederick E., E-mail: frederick-domann@uiowa.edu [Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, IA (United States); Department of Radiation Oncology, The University of Iowa, Iowa City, IA (United States); Department of Surgery, The University of Iowa, Iowa City, IA (United States)

    2014-02-01

    The aryl hydrocarbon receptor (AhR) is an important mediator of toxic responses after exposure to xenobiotics including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and dioxin-like polychlorinated biphenyls (PCBs). Activation of AhR responsive genes requires AhR dimerization with the aryl hydrocarbon receptor nuclear translocator (ARNT), a heterodimeric partner also shared by the hypoxia-inducible factor-1α (HIF-1α) protein. TCDD-stimulated AhR transcriptional activity can be influenced by hypoxia; however, it less well known whether hypoxia interferes with AhR transcriptional transactivation in the context of PCB-mediated AhR activation in human cells. Elucidation of this interaction is important in liver hepatocytes which extensively metabolize ingested PCBs and experience varying degrees of oxygen tension during normal physiologic function. This study was designed to assess the effect of hypoxia on AhR transcriptional responses after exposure to 3,3′,4,4′,5-pentachlorobiphenyl (PCB 126). Exposure to 1% O{sub 2} prior to PCB 126 treatment significantly inhibited CYP1A1 mRNA and protein expression in human HepG2 and HaCaT cells. CYP1A1 transcriptional activation was significantly decreased upon PCB 126 stimulation under conditions of hypoxia. Additionally, hypoxia pre-treatment reduced PCB 126 induced AhR binding to CYP1 target gene promoters. Importantly, ARNT overexpression rescued cells from the inhibitory effect of hypoxia on XRE-luciferase reporter activity. Therefore, the mechanism of interference of the signaling crosstalk between the AhR and hypoxia pathways appears to be at least in part dependent on ARNT availability. Our results show that AhR activation and CYP1A1 expression induced by PCB 126 were significantly inhibited by hypoxia and hypoxia might therefore play an important role in PCB metabolism and toxicity. - Highlights: • Significant crosstalk exists between AhR and HIF-1α signaling. • Hypoxia perturbs PCB 126 induced AhR function and

  2. Knock out of the BASIGIN/CD147 chaperone of lactate/H+ symporters disproves its pro-tumour action via extracellular matrix metalloproteases (MMPs) induction.

    Marchiq, Ibtissam; Albrengues, Jean; Granja, Sara; Gaggioli, Cédric; Pouysségur, Jacques; Simon, Marie-Pierre

    2015-09-22

    BASIGIN/CD147/EMMPRIN is a multifunctional transmembrane glycoprotein strongly expressed in tumours. BASIGIN controls tumour metabolism, particularly glycolysis by facilitating lactic acid export through the two monocarboxylate transporters MCT1 and hypoxia-inducible MCT4. However, before being recognized as a co-carrier of MCTs, BASIGIN was described as an inducer of extracellular matrix metalloproteases (MMPs). Early on, a model emerged in which, tumour cells use the extracellular domain of BASIGIN to recognize and stimulate neighbouring fibroblasts to produce MMPs. However, this model has remained hypothetical since a direct link between BASIGIN and MMPs production has not yet been clearly established. To validate the BASIGIN/MMP hypothesis, we developed BASIGIN knockouts in three human tumour cell lines derived from glioma, colon, and lung adenocarcinoma. By using co-culture experiments of either human or mouse fibroblasts and tumour cell lines we showed, contrary to what has been abundantly published, that the disruption of BASIGIN in tumour cells and in MEFs has no action on the production of MMPs. Our findings do not support the notion that the pro-tumoural action of BASIGIN is mediated via induction of MMPs. Therefore, we propose that to date, the strongest pro-tumoural action of BASIGIN is mediated through the control of fermentative glycolysis.

  3. The effect of BW12C on radiosensitivity and necrosis of murine tissues and tumours

    Stevens, G.; Hill, S.A.; Joiner, M.C.; Joiner, B.; Johns, H.; Williams, K.; Denekamp, J.

    1994-01-01

    BW12C is a drug that has the potential to induce normal tissue and tumour hypoxia by binding to haemoglobin, increasing its affinity for oxygen and thereby reducing oxygen availability to tissues. Initial results suggested that BW12C administration caused significant radioprotection of normal tissues and induced tumour necrosis, but variable results have been reported subsequently. This work was carried to extend the range of observations concerning the ability of BW12C to radioprotect normal tissues and tumours and to induce necrosis of tumours of the mouse. BW12C was administered as 70 mg/kg intravenous 15 min before irradiation of jejunum in CBA mice and of foot skin in WHT mice with single doses of 240 kVp X-rays while mice breathed gases of varying oxygen tensions. The radiosensitivities of these tissues were assessed by the crypt survival assay and the acute skin reaction, respectively. The radiosensitivity of CaNT tumours to single fraction irradiation was assessed by the regrowth delay assay following administration of single or multiple does of BW12C at varying times to air-breathing CBA mice. The radiation response was compared to the radiosensitivity of clamped tumours. The effect of BW12C alone on tumours was assessed by regrowth delay and histological examination for necrosis. Single or multiple doses of BW12C did not influence the radiosensitivity of CaNT tumours, although marked radioprotection could be induced by clamping the tumours during irradiation. Multiple doses of BW12C alone led to a slight increase in necrosis of the CaNT tumour but did not alter its growth rate. BW12C alone did not induce necrosis of the murine JT lymphoma. The results shown that BW12C did not have a significant effect as a radioprotective or necrotizing agent in these experimental systems. The reported differences in the radiomodifying effects of BW12C are probably tissue-specific and relate to complex biochemical and physiological interactions. 18 refs., 4 figs

  4. The acute in vitro and in vivo radiosensitivity of human lung tumour lines

    Duchesne, G.M.; Peacock, J.H.; Steel, G.G.

    1986-01-01

    Eleven human lung tumour lines have been established in xenograft or tissue culture, and the responses to acute irradiation of the 10 lines which cloned in soft agar were assayed. In vitro radiosensitivity was evaluated using the multitarget and linear quadratic models of cell survival and the surviving fraction at 2 Gy. Significant differences in the response of the different cell types were found, the large-cell phenotype exhibiting radioresistance, and small-cell carcinomas and adenocarcinomas being radiosensitive. No differences in the capacity of the different tumour types to repair radiation damage were demonstrated. In vivo and spheroid response was modified by the effects of hypoxia and cell-contact phenomena. The results suggested that hyperfractionation would be useful in the clinical management of adenocarcinoma and small-cell carcinoma. (Auth.)

  5. HIF1α and HIF2α: sibling rivalry in hypoxic tumour growth and progression.

    Keith, Brian; Johnson, Randall S; Simon, M Celeste

    2011-12-15

    Hypoxia-inducible factors (HIFs) are broadly expressed in human cancers, and HIF1α and HIF2α were previously suspected to promote tumour progression through largely overlapping functions. However, this relatively simple model has now been challenged in light of recent data from various approaches that reveal unique and sometimes opposing activities of these HIFα isoforms in both normal physiology and disease. These effects are mediated in part through the regulation of unique target genes, as well as through direct and indirect interactions with important oncoproteins and tumour suppressors, including MYC and p53. As HIF inhibitors are currently undergoing clinical evaluation as cancer therapeutics, a more thorough understanding of the unique roles performed by HIF1α and HIF2α in human neoplasia is warranted.

  6. HIF-2α Expression Regulates Sprout Formation into 3D Fibrin Matrices in Prolonged Hypoxia in Human Microvascular Endothelial Cells.

    Nauta, Tessa D; Duyndam, Monique C A; Weijers, Ester M; van Hinsbergh, Victor M W; Koolwijk, Pieter

    2016-01-01

    During short-term hypoxia, Hypoxia Inducible Factors (particular their subunits HIF-1α and HIF-2α) regulate the expression of many genes including the potent angiogenesis stimulator VEGF. However, in some pathological conditions chronic hypoxia occurs and is accompanied by reduced angiogenesis. We investigated the effect of prolonged hypoxia on the proliferation and sprouting ability of human microvascular endothelial cells and the involvement of the HIFs and Dll4/Notch signaling. Human microvascular endothelial cells (hMVECs), cultured at 20% oxygen for 14 days and seeded on top of 3D fibrin matrices, formed sprouts when stimulated with VEGF-A/TNFα. In contrast, hMVECs precultured at 1% oxygen for 14 days were viable and proliferative, but did not form sprouts into fibrin upon VEGF-A/TNFα stimulation at 1% oxygen. Silencing of HIF-2α with si-RNA partially restored the inhibition of endothelial sprouting, whereas HIF-1α or HIF-3α by si-RNA had no effect. No involvement of Dll4/Notch pathway in the inhibitory effect on endothelial sprouting by prolonged hypoxia was found. In addition, hypoxia decreased the production of urokinase-type plasminogen activator (uPA), needed for migration and invasion, without a significant effect on its inhibitor PAI-1. This was independent of HIF-2α, as si-HIF-2α did not counteract uPA reduction. Prolonged culturing of hMVECs at 1% oxygen inhibited endothelial sprouting into fibrin. Two independent mechanisms contribute. Silencing of HIF-2α with si-RNA partially restored the inhibition of endothelial sprouting pointing to a HIF-2α-dependent mechanism. In addition, reduction of uPA contributed to reduced endothelial tube formation in a fibrin matrix during prolonged hypoxia.

  7. Kinetic modeling in PET imaging of hypoxia

    Li, Fan; Jørgensen, Jesper Tranekjær; Hansen, Anders E

    2014-01-01

    be used for non-invasive mapping of tissue oxygenation in vivo and several hypoxia specific PET tracers have been developed. Evaluation of PET data in the clinic is commonly based on visual assessment together with semiquantitative measurements e.g. standard uptake value (SUV). However, dynamic PET......Tumor hypoxia is associated with increased therapeutic resistance leading to poor treatment outcome. Therefore the ability to detect and quantify intratumoral oxygenation could play an important role in future individual personalized treatment strategies. Positron Emission Tomography (PET) can...... analysis for PET imaging of hypoxia....

  8. Tumour markers in gynaecological practice

    Adewole, I.F.

    1999-02-01

    Gynaecological cancers are fairly common in developing countries and represent about 26 % f all cancers. Application of cervical cytology screening nationally has made cervical cancer one of the most preventable malignant diseases thus eliminating the challenges of advanced cancer management. Tumour markers has played a most crucial role in this respect

  9. Hypoxia-Induced Collagen Synthesis of Human Lung Fibroblasts by Activating the Angiotensin System

    Shan-Shan Liu

    2013-12-01

    Full Text Available The exact molecular mechanism that mediates hypoxia-induced pulmonary fibrosis needs to be further clarified. The aim of this study was to explore the effect and underlying mechanism of angiotensin II (Ang II on collagen synthesis in hypoxic human lung fibroblast (HLF cells. The HLF-1 cell line was used for in vitro studies. Angiotensinogen (AGT, angiotensin converting enzyme (ACE, angiotensin II type 1 receptor (AT1R and angiotensin II type 2 receptor (AT2R expression levels in human lung fibroblasts were analysed using real-time polymerase chain reaction (RT-PCR after hypoxic treatment. Additionally, the collagen type I (Col-I, AT1R and nuclear factor κappaB (NF-κB protein expression levels were detected using Western blot analysis, and NF-κB nuclear translocation was measured using immunofluorescence localization analysis. Ang II levels in HLF-1 cells were measured with an enzyme-linked immunosorbent assay (ELISA. We found that hypoxia increased Col-I mRNA and protein expression in HLF-1 cells, and this effect could be inhibited by an AT1R or AT2R inhibitor. The levels of NF-κB, RAS components and Ang II production in HLF-1 cells were significantly increased after the hypoxia exposure. Hypoxia or Ang II increased NF-κB-p50 protein expression in HLF-1 cells, and the special effect could be inhibited by telmisartan (TST, an AT1R inhibitor, and partially inhibited by PD123319, an AT2R inhibitor. Importantly, hypoxia-induced NF-κB nuclear translocation could be nearly completely inhibited by an AT1R or AT2R inhibitor. Furthermore pyrrolidine dithiocarbamate (PDTC, a NF-κB blocker, abolished the expression of hypoxia-induced AT1R and Col-I in HLF-1 cells. Our results indicate that Ang II-mediated NF-κB signalling via ATR is involved in hypoxia-induced collagen synthesis in human lung fibroblasts.

  10. Effect of oxygen on cardiac differentiation in mouse iPS cells: role of hypoxia inducible factor-1 and Wnt/beta-catenin signaling.

    Tanya L Medley

    Full Text Available BACKGROUND: Disturbances in oxygen levels have been found to impair cardiac organogenesis. It is known that stem cells and differentiating cells may respond variably to hypoxic conditions, whereby hypoxia may enhance stem cell pluripotency, while differentiation of multiple cell types can be restricted or enhanced under hypoxia. Here we examined whether HIF-1alpha modulated Wnt signaling affected differentiation of iPS cells into beating cardiomyocytes. OBJECTIVE: We investigated whether transient and sustained hypoxia affects differentiation of cardiomyocytes derived from murine induced pluripotent stem (iPS cells, assessed the involvement of HIF-1alpha (hypoxia-inducible factor-1alpha and the canonical Wnt pathway in this process. METHODS: Embryoid bodies (EBs derived from iPS cells were differentiated into cardiomyocytes and were exposed either to 24 h normoxia or transient hypoxia followed by a further 13 days of normoxic culture. RESULTS: At 14 days of differentiation, 59 ± 2% of normoxic EBs were beating, whilst transient hypoxia abolished beating at 14 days and EBs appeared immature. Hypoxia induced a significant increase in Brachyury and islet-1 mRNA expression, together with reduced troponin C expression. Collectively, these data suggest that transient and sustained hypoxia inhibits maturation of differentiating cardiomyocytes. Compared to normoxia, hypoxia increased HIF-1alpha, Wnt target and ligand genes in EBs, as well as accumulation of HIF-1alpha and beta-catenin in nuclear protein extracts, suggesting involvement of the Wnt/beta-catenin pathway. CONCLUSION: Hypoxia impairs cardiomyocyte differentiation and activates Wnt signaling in undifferentiated iPS cells. Taken together the study suggests that oxygenation levels play a critical role in cardiomyocyte differentiation and suggest that hypoxia may play a role in early cardiogenesis.

  11. Mohs micrographic surgery of rare cutaneous tumours

    Flohil, S.C.; Lee, C.B. van; Beisenherz, J.; Mureau, M.A.M.; Overbeek, L.I.H.; Nijsten, T.; Bos, R.R.

    2017-01-01

    BACKGROUND: Recurrence rates after Mohs micrographic surgery (MMS) for rare cutaneous tumours are poorly defined. OBJECTIVE: To investigate the recurrence rate after MMS for rare cutaneous tumours at a university centre. METHODS & MATERIALS: Retrospective review of all rare cutaneous tumours treated

  12. [Influence of exogenous gamma-aminobutyric acid (GABA) on GABA metabolism and amino acid contents in roots of melon seedling under hypoxia stress].

    Wang, Chun-Yan; Li, Jing-Rui; Xia, Qing-Ping; Wu, Xiao-Lei; Gao, Hong-Bo

    2014-07-01

    This paper investigated the influence of gamma-aminobutyric acid (GABA) on GABA metabolism and amino acid content under hypoxia stress by accurately controlling the level of dissolved oxygen in hydroponics, using the roots of melon 'Xiyu 1' seedlings as the test material. The results showed that compared with the control, the growth of roots was inhibited seriously under hypoxia stress. Meanwhile, the hypoxia-treated roots had significantly higher activities of glutamate decarboxylase (GAD), glutamate dehydrogenase (GDH), glutamate synthase (GOGAT), glutamine synthetase (GS), alanine aminotransferase (ALT), aspartate aminotransferase (AST) as well as the contents of GABA, pyruvic acid, alanine (Ala) and aspartic acid (Asp). But the contents of glutamic acid (Glu) and alpha-keto glutaric acid in roots under hypoxia stress was obviously lower than those of the control. Exogenous treatment with GABA alleviated the inhibition effect of hypoxia stress on root growth, which was accompanied by an increase in the contents of endogenous GABA, Glu, alpha-keto glutaric acid and Asp. Furthermore, under hypoxia stress, the activities of GAD, GDH, GOGAT, GS, ALT, AST as well as the contents of pyruvic acid and Ala significantly decreased in roots treated with GABA. However, adding GABA and viny-gamma-aminobutyric acid (VGB) reduced the alleviation effect of GABA on melon seedlings under hypoxia stress. The results suggested that absorption of GABA by roots could alleviate the injury of hypoxia stress to melon seedlings. This meant that GABA treatment allows the normal physiological metabolism under hypoxia by inhibiting the GAD activity through feedback and maintaining higher Glu content as well as the bal- ance of carbon and nitrogen.

  13. Radiosensitization by the histone deacetylase inhibitor vorinostat under hypoxia and with capecitabine in experimental colorectal carcinoma

    Saelen, Marie Grøn; Ree, Anne Hansen; Kristian, Alexandr; Fleten, Karianne Giller; Furre, Torbjørn; Hektoen, Helga Helseth; Flatmark, Kjersti

    2012-01-01

    The histone deacetylase inhibitor vorinostat is a candidate radiosensitizer in locally advanced rectal cancer (LARC). Radiosensitivity is critically influenced by hypoxia; hence, it is important to evaluate the efficacy of potential radiosensitizers under variable tissue oxygenation. Since fluoropyrimidine-based chemoradiotherapy (CRT) is the only clinically validated regimen in LARC, efficacy in combination with this established regimen should be assessed in preclinical models before a candidate drug enters clinical trials. Radiosensitization by vorinostat under hypoxia was studied in four colorectal carcinoma cell lines and in one colorectal carcinoma xenograft model by analysis of clonogenic survival and tumor growth delay, respectively. Radiosensitizing effects of vorinostat in combination with capecitabine were assessed by evaluation of tumor growth delay in two colorectal carcinoma xenografts models. Under hypoxia, radiosensitization by vorinostat was demonstrated in vitro in terms of decreased clonogenicity and in vivo as inhibition of tumor growth. Adding vorinostat to capecitabine-based CRT increased radiosensitivity of xenografts in terms of inhibited tumor growth. Vorinostat sensitized colorectal carcinoma cells to radiation under hypoxia in vitro and in vivo and improved therapeutic efficacy in combination with capecitabine-based CRT in vivo. The results encourage implementation of vorinostat into CRT in LARC trials

  14. The dual role of autophagy under hypoxia-involvement of interaction between autophagy and apoptosis.

    Li, Mengmeng; Tan, Jin; Miao, Yuyang; Lei, Ping; Zhang, Qiang

    2015-06-01

    Hypoxia is one of severe cellular stress and it is well known to be associated with a worse outcome since a lack of oxygen accelerates the induction of apoptosis. Autophagy, an important and evolutionarily conserved mechanism for maintaining cellular homeostasis, is closely related to the apoptosis caused by hypoxia. Generally autophagy blocks the induction of apoptosis and inhibits the activation of apoptosis-associated caspase which could reduce cellular injury. However, in special cases, autophagy or autophagy-relevant proteins may help to induce apoptosis, which could aggravate cell damage under hypoxia condition. In addition, the activation of apoptosis-related proteins-caspase can also degrade autophagy-related proteins, such as Atg3, Atg4, Beclin1 protein, inhibiting autophagy. Although the relationship between autophagy and apoptosis has been known for rather complex for more than a decade, the underlying regulatory mechanisms have not been clearly understood. This short review discusses and summarizes the dual role of autophagy and the interaction and molecular regulatory mechanisms between autophagy and apoptosis under hypoxia.

  15. Radiosensitization by the histone deacetylase inhibitor vorinostat under hypoxia and with capecitabine in experimental colorectal carcinoma.

    Saelen, Marie Grøn; Ree, Anne Hansen; Kristian, Alexandr; Fleten, Karianne Giller; Furre, Torbjørn; Hektoen, Helga Helseth; Flatmark, Kjersti

    2012-09-27

    The histone deacetylase inhibitor vorinostat is a candidate radiosensitizer in locally advanced rectal cancer (LARC). Radiosensitivity is critically influenced by hypoxia; hence, it is important to evaluate the efficacy of potential radiosensitizers under variable tissue oxygenation. Since fluoropyrimidine-based chemoradiotherapy (CRT) is the only clinically validated regimen in LARC, efficacy in combination with this established regimen should be assessed in preclinical models before a candidate drug enters clinical trials. Radiosensitization by vorinostat under hypoxia was studied in four colorectal carcinoma cell lines and in one colorectal carcinoma xenograft model by analysis of clonogenic survival and tumor growth delay, respectively. Radiosensitizing effects of vorinostat in combination with capecitabine were assessed by evaluation of tumor growth delay in two colorectal carcinoma xenografts models. Under hypoxia, radiosensitization by vorinostat was demonstrated in vitro in terms of decreased clonogenicity and in vivo as inhibition of tumor growth. Adding vorinostat to capecitabine-based CRT increased radiosensitivity of xenografts in terms of inhibited tumor growth. Vorinostat sensitized colorectal carcinoma cells to radiation under hypoxia in vitro and in vivo and improved therapeutic efficacy in combination with capecitabine-based CRT in vivo. The results encourage implementation of vorinostat into CRT in LARC trials.

  16. Radiosensitization by the histone deacetylase inhibitor vorinostat under hypoxia and with capecitabine in experimental colorectal carcinoma

    Saelen Marie

    2012-09-01

    Full Text Available Abstract Background The histone deacetylase inhibitor vorinostat is a candidate radiosensitizer in locally advanced rectal cancer (LARC. Radiosensitivity is critically influenced by hypoxia; hence, it is important to evaluate the efficacy of potential radiosensitizers under variable tissue oxygenation. Since fluoropyrimidine-based chemoradiotherapy (CRT is the only clinically validated regimen in LARC, efficacy in combination with this established regimen should be assessed in preclinical models before a candidate drug enters clinical trials. Methods Radiosensitization by vorinostat under hypoxia was studied in four colorectal carcinoma cell lines and in one colorectal carcinoma xenograft model by analysis of clonogenic survival and tumor growth delay, respectively. Radiosensitizing effects of vorinostat in combination with capecitabine were assessed by evaluation of tumor growth delay in two colorectal carcinoma xenografts models. Results Under hypoxia, radiosensitization by vorinostat was demonstrated in vitro in terms of decreased clonogenicity and in vivo as inhibition of tumor growth. Adding vorinostat to capecitabine-based CRT increased radiosensitivity of xenografts in terms of inhibited tumor growth. Conclusions Vorinostat sensitized colorectal carcinoma cells to radiation under hypoxia in vitro and in vivo and improved therapeutic efficacy in combination with capecitabine-based CRT in vivo. The results encourage implementation of vorinostat into CRT in LARC trials.

  17. Human erythropoietin response to hypocapnic hypoxia, normocapnic hypoxia, and hypocapnic normoxia

    Klausen, T; Christensen, H; Hansen, J M

    1996-01-01

    exposed to 2 h each of hypocapnic hypoxia, normocapnic hypoxia, hypocapnic normoxia, and normal breathing of room air (control experiment). During the control experiment, serum-EPO showed significant variations (ANOVA P = 0.047) with a 15% increase in mean values. The serum-EPO measured in the other...... (10% Co2 with 10% O2) to the hypoxic gas mixture. This elicited an increased ventilation, unaltered arterial pH and haemoglobin oxygen affinity, a lower degree of hypoxia than during hypocapnic hypoxia, and no significant changes in serum-EPO (ANOVA P > 0.05). Hypocapnic normoxia, produced...

  18. Tumor microenvironment conditions alter Akt and Na+/H+ exchanger NHE1 expression in endothelial cells more than hypoxia alone

    Pedersen, Anna-Kathrine; Mendes Lopes de Melo, Joana; Mørup, Nina

    2017-01-01

    Background Chronic angiogenesis is a hallmark of most tumors and takes place in a hostile tumor microenvironment (TME) characterized by hypoxia, low nutrient and glucose levels, elevated lactate and low pH. Despite this, most studies addressing angiogenic signaling use hypoxia as a proxy for tumor...... cells, Akt1 most abundantly. Akt1 protein expression was reduced by TME yet unaffected by hypoxia, while Akt phosphorylation was increased by TME. The Akt loss was partly reversed by MCF-7 human breast cancer cell conditioned medium, suggesting that in vivo, the cancer cell secretome may compensate....../inhibition. Conclusions NHE1 and Akt are downregulated by TME conditions, more potently than by hypoxia alone. This inhibits endothelial cell migration and growth in a manner likely modulated by the cancer cell secretome....

  19. BOLD contrast fMRI of whole rodent tumour during air or carbogen breathing using echo-planar imaging at 1.5 T

    Landuyt, W.; Bogaert, W. van den; Lambin, P.; Hermans, R.; Bosmans, H.; Sunaert, S.; Beatse, E.; Farina, D.; Meijerink, M.; Zhang, H.; Marchal, G.

    2001-01-01

    The aim of this study was to evaluate the feasibility of functional MR imaging (fMRI) at 1.5 T, exploiting blood oxygenation level-dependent (BOLD) contrast, for detecting changes in whole-tumour oxygenation induced by carbogen (5% CO 2 +95% O 2 ) inhalation of the host. Adult WAG/Rij rats with rhabdomyosarcomas growing subcutaneously in the lower flank were imaged when tumours reached sizes between 1 and 11 cm 3 (n=12). Air and carbogen were alternatively supplied at 2 l/min using a snout mask. Imaging was done on a 1.5-T MR scanner using a T2*-weighted gradient-echo, echo-planar imaging (GE-EPI) sequence. Analysis of the whole-tumour EPI images was based on statistical parametric maps. Voxels with and without signal intensity changes (SIC) were recorded. Significance thresholds were set at p<0.05, corrected for multiple comparisons. In continuous air breathing condition, 3 of 12 tumours showed significant negative SIC and 1 tumour had a clear-cut positive SIC. The remaining tumours showed very little or no change. When switching to carbogen breathing, the SIC were significantly positive in 10 of 12 tumours. Negative SIC were present in 4 tumours, of which three were simultaneously characterised by positive SIC. The overall analysis indicated that 6 of the 12 tumours could be considered as strong positive responders to carbogen. Our research demonstrates the applicability of fMRI GE-EPI at 1.5 T to study whole-tumour oxygenation non-invasively. The observed negative SIC during air condition may reflect the presence of transient hypoxia during these measurements. Selection of tumours on the basis of their individual response to carbogen is possible, indicating a role of such non-invasive measurements for using tailor-made treatments. (orig.)

  20. Hypoxia induced expression of endogenous markers in vitro is highly influenced by pH

    Sorensen, Brita Singers; Alsner, Jan; Overgaard, Jens; Horsman, Michael R.

    2007-01-01

    Background: Genes such as carbonic anhydrase IX (Ca9), glucose transporter 1 (Glut1), lactate dehydrogenase A (LDH-A), osteopontin (OPN) and lysyl oxidase (LOX) have been suggested as hypoxic markers, but inconsistent results suggest that factors other than oxygen influence their expression. The current study is a detailed investigation using a range of pH values from 6.3 to 7.5 in two human cell lines to establish the pH dependency of hypoxia induced gene expression. Methods: Human tumour cell lines (uterine cervix squamous cell carcinoma (SiHa) and pharyngeal squamous cell carcinoma [FaDu DD ]) were used. Hypoxia was induced by gassing cells in airtight chambers with various oxygen concentrations (21%, 1%, 0.1%, 0.01% and 0%) for up to 24 h. The media were titrated to a range of pH values (7.5, 7.0, 6.7, 6.5 and 6.3). Gene expression was determined by real-time PCR. Results: In both SiHa and FaDu DD cells Ca9 and LOX reached the highest level of expression at 1% oxygen. In FaDu DD cells, a pH of 6.5 had a medium suppression effect on the hypoxia induced expression of Ca9. pH 6.3 resulted in severe suppression of expression for Ca9 and LOX in both SiHa and FaDu DD . Glut1 and LDH-A had a similar expression pattern to each other, with a maximum expression at 0.01% oxygen, in both cell lines. For these genes pH 6.5 and 6.3 changed the expression pattern in SiHa cells. OPN was up regulated at low oxygen in SiHa cells, but was not induced by hypoxia in FaDu DD cells. Conclusion: As tumour hypoxia occurs in a deprived microenvironment, other environmental factors, for example low pH, might interact with the effect of low oxygen concentration on gene expression. This study shows that pH in two cell lines has a profound influence on the oxygen dependent induction of certain endogenous hypoxic markers

  1. Hypoxia and the heart of poikilotherms

    Ošťádal, Bohuslav

    2014-01-01

    Roč. 1, č. 1 (2014), s. 28-32 Institutional support: RVO:67985823 Keywords : blood supply heart * poikilotherms * tolerance to hypoxia Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery

  2. Redox signaling during hypoxia in mammalian cells

    Kimberly A. Smith

    2017-10-01

    Full Text Available Hypoxia triggers a wide range of protective responses in mammalian cells, which are mediated through transcriptional and post-translational mechanisms. Redox signaling in cells by reactive oxygen species (ROS such as hydrogen peroxide (H2O2 occurs through the reversible oxidation of cysteine thiol groups, resulting in structural modifications that can change protein function profoundly. Mitochondria are an important source of ROS generation, and studies reveal that superoxide generation by the electron transport chain increases during hypoxia. Other sources of ROS, such as the NAD(PH oxidases, may also generate oxidant signals in hypoxia. This review considers the growing body of work indicating that increased ROS signals during hypoxia are responsible for regulating the activation of protective mechanisms in diverse cell types.

  3. Hypoxia, HIF-1 Regulation and Cancer Therapy

    Groot, A.J.

    2008-01-01

    Oxygen insufficiency (hypoxia) is a common feature of human cancer and associated with tumor aggressiveness and poor clinical outcome. Furthermore, hypoxic tumors are more resistant to ionizing radiation and chemotherapy contributing to their unfavorable prognosis. The oxygen sensing pathway is

  4. 2007 Hypoxia Watch Bottom CTD Station Locations

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Hypoxia Watch project provides near-real-time, web-based maps of dissolved oxygen near the sea floor over the Texas-Louisiana continental shelf during a...

  5. 2004 Hypoxia Watch Bottom CTD Station Locations

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Hypoxia Watch project provides near-real-time, web-based maps of dissolved oxygen near the sea floor over the Texas-Louisiana continental shelf during a...

  6. 2005 Hypoxia Watch Bottom CTD Station Locations

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Hypoxia Watch project provides near-real-time, web-based maps of dissolved oxygen near the sea floor over the Texas-Louisiana continental shelf during a...

  7. 2002 Hypoxia Watch Bottom CTD Station Locations

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Hypoxia Watch project provides near-real-time, web-based maps of dissolved oxygen near the sea floor over the Texas-Louisiana continental shelf during a...

  8. 2003 Hypoxia Watch Bottom CTD Station Locations

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Hypoxia Watch project provides near-real-time, web-based maps of dissolved oxygen near the sea floor over the Texas-Louisiana continental shelf during a...

  9. 2001 Hypoxia Watch Bottom CTD Station Locations

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Hypoxia Watch project provides near-real-time, web-based maps of dissolved oxygen near the sea floor over the Texas-Louisiana continental shelf during a...

  10. Total {sup 18}F-dopa PET tumour uptake reflects metabolic endocrine tumour activity in patients with a carcinoid tumour

    Fiebrich, Helle-Brit; Walenkamp, Annemiek M.; Vries, Elisabeth G.E. de [University Medical Centre Groningen, Department of Medical Oncology, Groningen (Netherlands); Jong, Johan R. de; Koopmans, Klaas Pieter; Dierckx, Rudi A.J.O.; Brouwers, Adrienne H. [University Medical Centre Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); Kema, Ido P. [University Medical Centre Groningen, Department of Laboratory Medicine, Groningen (Netherlands); Sluiter, Wim; Links, Thera P. [University Medical Centre Groningen, Department of Endocrinology, Groningen (Netherlands)

    2011-10-15

    Positron emission tomography (PET) using 6-[{sup 18}F]fluoro-L-dihydroxyphenylalanine ({sup 18}F-dopa) has an excellent sensitivity to detect carcinoid tumour lesions. {sup 18}F-dopa tumour uptake and the levels of biochemical tumour markers are mediated by tumour endocrine metabolic activity. We evaluated whether total {sup 18}F-dopa tumour uptake on PET, defined as whole-body metabolic tumour burden (WBMTB), reflects tumour load per patient, as measured with tumour markers. Seventy-seven consecutive carcinoid patients who underwent an {sup 18}F-dopa PET scan in two previously published studies were analysed. For all tumour lesions mean standardised uptake values (SUVs) at 40% of the maximal SUV and tumour volume on {sup 18}F-dopa PET were determined and multiplied to calculate a metabolic burden per lesion. WBMTB was the sum of the metabolic burden of all individual lesions per patient. The 24-h urinary serotonin, urine and plasma 5-hydroxindoleacetic acid (5-HIAA), catecholamines (nor)epinephrine, dopamine and their metabolites, measured in urine and plasma, and serum chromogranin A served as tumour markers. All but 1 were evaluable for WBMTB; 74 patients had metastatic disease. {sup 18}F-dopa PET detected 979 lesions. SUV{sub max} on {sup 18}F-dopa PET varied up to 29-fold between individual lesions within the same patients. WBMTB correlated with urinary serotonin (r = 0.51) and urinary and plasma 5-HIAA (r = 0.78 and 0.66). WBMTB also correlated with urinary norepinephrine, epinephrine, dopamine and plasma dopamine, but not with serum chromogranin A. Tumour load per patient measured with {sup 18}F-dopa PET correlates with tumour markers of the serotonin and catecholamine pathway in urine and plasma in carcinoid patients, reflecting metabolic tumour activity. (orig.)

  11. Intermittent hypoxia induces hyperlipidemia in lean mice.

    Li, Jianguo; Thorne, Laura N; Punjabi, Naresh M; Sun, Cheuk-Kwan; Schwartz, Alan R; Smith, Philip L; Marino, Rafael L; Rodriguez, Annabelle; Hubbard, Walter C; O'Donnell, Christopher P; Polotsky, Vsevolod Y

    2005-09-30

    Obstructive sleep apnea, a syndrome leading to recurrent intermittent hypoxia (IH), has been associated previously with hypercholesterolemia, independent of underlying obesity. We examined the effects of experimentally induced IH on serum lipid levels and pathways of lipid metabolism in the absence and presence of obesity. Lean C57BL/6J mice and leptin-deficient obese C57BL/6J-Lep(ob) mice were exposed to IH for five days to determine changes in serum lipid profile, liver lipid content, and expression of key hepatic genes of lipid metabolism. In lean mice, exposure to IH increased fasting serum levels of total cholesterol, high-density lipoprotein (HDL) cholesterol, phospholipids (PLs), and triglycerides (TGs), as well as liver TG content. These changes were not observed in obese mice, which had hyperlipidemia and fatty liver at baseline. In lean mice, IH increased sterol regulatory element binding protein 1 (SREBP-1) levels in the liver, increased mRNA and protein levels of stearoyl-coenzyme A desaturase 1 (SCD-1), an important gene of TG and PL biosynthesis controlled by SREBP-1, and increased monounsaturated fatty acid content in serum, which indicated augmented SCD-1 activity. In addition, in lean mice, IH decreased protein levels of scavenger receptor B1, regulating uptake of cholesterol esters and HDL by the liver. We conclude that exposure to IH for five days increases serum cholesterol and PL levels, upregulates pathways of TG and PL biosynthesis, and inhibits pathways of cholesterol uptake in the liver in the lean state but does not exacerbate the pre-existing hyperlipidemia and metabolic disturbances in leptin-deficient obesity.

  12. Cognition Effects of Low-Grade Hypoxia

    2016-07-01

    human short-term memory . Br J Anaesth. 1971; 43(6):548–552. 3. Crow TJ, Kelman GR. Psychological effects of mild acute hypoxia. Br J Anaesth. 1973; 45...Journal Article 3. DATES COVERED (From – To) Jan 2003 – Sep 2005 4. TITLE AND SUBTITLE Cognition Effects of Low-Grade Hypoxia 5a. CONTRACT NUMBER... cognitive function are reported in this paper. The study compared cognitive function during short exposures at four different altitudes. Ninety-one

  13. Hypoxia independent drivers of melanoma angiogenesis

    Svenja eMeierjohann

    2015-05-01

    Full Text Available Tumor angiogenesis is a process which is traditionally regarded as the tumor`s response to low nutrient supply occurring under hypoxic conditions. However,