scholarly journals Gene Suppression of Transketolase-Like Protein 1 (TKTL1) Sensitizes Glioma Cells to Hypoxia and Ionizing Radiation

2018 ◽  
Vol 19 (8) ◽  
pp. 2168 ◽  
Author(s):  
Sonja Heller ◽  
Gabriele Maurer ◽  
Christina Wanka ◽  
Ute Hofmann ◽  
Anna-Luisa Luger ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Hypoxia Inducible Factor ◽  
Glioma Cells ◽  
In Vitro Study ◽  
Clonogenic Survival ◽  
Pentose Phosphate ◽  
Gene Suppression ◽  
The Impact

In several tumor entities, transketolase-like protein 1 (TKTL1) has been suggested to promote the nonoxidative part of the pentose phosphate pathway (PPP) and thereby to contribute to a malignant phenotype. However, its role in glioma biology has only been sparsely documented. In the present in vitro study using LNT-229 glioma cells, we analyzed the impact of TKTL1 gene suppression on basic metabolic parameters and on survival following oxygen restriction and ionizing radiation. TKTL1 was induced by hypoxia and by hypoxia-inducible factor-1α (HIF-1α). Knockdown of TKTL1 via shRNA increased the cells’ demand for glucose, decreased flux through the PPP and promoted cell death under hypoxic conditions. Following irradiation, suppression of TKTL1 expression resulted in elevated levels of reactive oxygen species (ROS) and reduced clonogenic survival. In summary, our results indicate a role of TKTL1 in the adaptation of tumor cells to oxygen deprivation and in the acquisition of radioresistance. Further studies are necessary to examine whether strategies that antagonize TKTL1 function will be able to restore the sensitivity of glioma cells towards irradiation and antiangiogenic therapies in the more complex in vivo environment.

scholarly journals SorCS3 Promotes the Internalization of p75NTR to Inhibit Glioma Progression

2021 ◽  
Author(s):  
Yanqiu Zhang ◽  
Yue Li ◽  
Yuhua Fan ◽  
Baoshan Zhao ◽  
Huan Liang ◽  
...  
Keyword(s):  
Glioma Cells ◽  
Tissue Microarrays ◽  
Cell Receptor ◽  
Receptor Internalization ◽  
Cellular Signal ◽  
Proliferation And Metastasis ◽  
The Impact ◽  
Glioma Progression

Abstract Background: Glioma is a fatal malignancy caused by dysregulation of cellular signal transduction. Internalization plays a key role in maintaining signalling balance. SorCS3 is involved in nerve cell receptor internalization. However, the impact of SorCS3 on the biological processes involved in glioma has not yet been reported. Here, we highlight the potential of SorCS3-mediated regulation of signalling receptor internalization as a rational target for therapeutic intervention in glioma.Methods: SorCS3 expression was analysed in the TCGA and CGGA databases and in tissue microarrays. The effects of SorCS3 on the proliferation and metastasis of glioma cells were examined in vitro and in vivo with Transwell, wound healing, EdU incorporation and nude mouse tumorigenicity assays. Fluorescent 5-FAM, SE-labelled proteins were used to detect the internalization of SorCS3 in glioma cells. Immunofluorescence and Co-IP assays were conducted to investigate the downstream effector of SorCS3. Moreover, Dynasore and Ro 08-2750, inhibitors of internalization and NGF binding to p75NTR, respectively, were used to validate the biological functions of SorCS3 in glioma.Results: Our data demonstrated that SorCS3 was downregulated in glioma tissues and closely related to favourable prognosis. Overexpression of SorCS3 inhibited the proliferation and metastasis of glioma cells in vitro and in vivo, while silencing of SorCS3 exerted the opposite effects. Mechanistic investigations showed that SorCS3 bound to p75NTR, which subsequently increased the internalization of p75NTR, and then transported p75NTR to the lysosome for degradation, ultimately contributing to inhibition of glioma progression.Conclusions: Our work suggests that SorSC3 is a marker of promising prognosis in glioma patients and suggests that SorCS3 regulates internalization, which plays an important role in inhibiting glioma progression.

scholarly journals Can Hypoxic Conditioning Improve Bone Metabolism? A Systematic Review

2019 ◽  
Vol 16 (10) ◽  
pp. 1799 ◽  
Author(s):  
Marta Camacho-Cardenosa ◽  
Alba Camacho-Cardenosa ◽  
Rafael Timón ◽  
Guillermo Olcina ◽  
Pablo Tomas-Carus ◽  
...  
Keyword(s):  
Bone Metabolism ◽  
Critical Role ◽  
Hypoxia Inducible Factor ◽  
Experimental Studies ◽  
Hormonal Responses ◽  
Hypoxia Exposure ◽  
Ambient Oxygen ◽  
The Impact

Among other functions, hypoxia-inducible factor plays a critical role in bone–vascular coupling and bone formation. Studies have suggested that hypoxic conditioning could be a potential nonpharmacological strategy for treating skeletal diseases. However, there is no clear consensus regarding the bone metabolism response to hypoxia. Therefore, this review aims to examine the impact of different modes of hypoxia conditioning on bone metabolism. The PubMed and Web of Science databases were searched for experimental studies written in English that investigated the effects of modification of ambient oxygen on bone remodelling parameters of healthy organisms. Thirty-nine studies analysed the effect of sustained or cyclic hypoxia exposure on genetic and protein expression and mineralisation capacity of different cell models; three studies carried out in animal models implemented sustained or cyclic hypoxia; ten studies examined the effect of sustained, intermittent or cyclic hypoxia on bone health and hormonal responses in humans. Different modes of hypoxic conditioning may have different impacts on bone metabolism both in vivo and in vitro. Additional research is necessary to establish the optimal cyclical dose of oxygen concentration and exposure time.

Temozolomide, irradiation and hypoxia promote homing of hematopoietic progenitor cells towards gliomas

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 20044-20044
Author(s):  
W. Wick ◽  
G. Tabatabai ◽  
B. Frank ◽  
M. Weller
Keyword(s):  
Progenitor Cells ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Tumor Hypoxia ◽  
Glioma Cells ◽  
Signaling Cascade ◽  
Hematopoietic Stem ◽  
The Impact

20044 Background: Temozolomide and irradiation are essential parts of the standard therapy and hypoxia is a critical aspect of the microenvironment of gliomas. IN the present study, we aimed at investigating the impact of these stimuli on the previously defined transforming growth factor beta (TGF-β)- and stromal cell-derived factor-1/CXC chemokine ligand 12 (SDF-1α/CXCL12)-dependent migration of adult hematopoietic stem and progenitor cells (HPC) towards glioma cells in vitro and the homing to experimental gliomas in vivo. Hyperthermia served as control. Methods and Results: Cerebral irradiation of nude mice at 21 days after intracerebral implantation of LNT-229 glioma induces tumor satellite formation and enhances the glioma tropism of HPC in vivo. Supernatants of temozolomide-treated, irradiated or hypoxic LNT-229 glioma cells promote HPC migration in vitro. Reporter assays reveal that the CXCL12 promoter activity is enhanced in LNT-229 glioma cells at 24 h after irradiation at 8 Gy or after exposure to 1% oxygen for 12 h. The irradiation- and hypoxia-induced release of CXCL12 depends on hypoxia inducible factor-1 alpha (HIF-1α), but not on p53. Induction of transcriptional activity of HIF-1α by hypoxia and irradiation requires an intact signaling cascade of TGF-β. Conclusions: Thus, we delineate a novel stress signaling cascade in glioma cells involving TGF-β, HIF-1α and CXCL12. Stress stimuli can be temozolomide, irradiation and hypoxia but not hyperthermia. These data suggest that the use of HPC as cellular vectors in the treatment of glioblastoma may well be combined with anti-angiogenic therapies which induce tumor hypoxia. [Table: see text]

Combined temozolomide and ionizing radiation induces galectin-1 and galectin-3 expression in a model of human glioma

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Lauren A. Bailey ◽  
Azemat Jamshidi-Parsian ◽  
Tulsi Patel ◽  
Nathan A. Koonce ◽  
Alan B. Diekman ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Ionizing Radiation ◽  
Protein Expression ◽  
Glioma Cell ◽  
Glioma Cells ◽  
Human Glioma ◽  
Glioma Recurrence ◽  
Galectin 3

AbstractBackground Despite aggressive treatment for glioblastoma multiforme (GBM), including surgical resection, radiotherapy and temozolomide (TMZ) chemotherapy, over 90% of patients experience tumor recurrence. Galectins are carbohydrate-binding proteins that are overexpressed in the stroma of GBM tumors, and are potent modulators of GBM cell migration and angiogenesis. The objective of this study was to analyze glioma and endothelial cell galectin expression in response to combined chemoradiation. Methodology The effects of TMZ, ionizing radiation, or combined chemoradiation on galectin protein secretion and expression were assessed in U87 orthotopically grown GBM tumors in mice, as well as in vitro in U87 human glioma cells and human umbilical vein endothelial cells (HUVECs). Results We found that combination chemoradiation increased galectin-1 and galectin-3 protein expression in U87 glioma cells. In response to radiation alone, U87 cells secreted significant levels of galectin-1 and galectin-3 into the microenvironment. HUVEC co-culture increased U87 galectin-1 and galectin-3 protein expression 14 - 20% following chemoradiation, and conferred a radioprotective benefit to U87 glioma cells. In vivo, radiation alone and combination chemoradiation significantly increased tumor galectin-1 expression in an orthotopic murine model of GBM. Conclusions Glioma cell galectin expression increased following combined chemoradiation, both in vitro and in vivo. The presence of endothelial cells further increased glioma cell galectin expression and survival, suggesting that crosstalk between tumor and endothelial cells in response to standard chemoradiation may be an important factor in mediating glioma recurrence, potentially via galectin upregulation.

The effects in vitro of TNF-α and its antagonist ‘etanercept’ on ejaculated human sperm

2017 ◽  
Vol 29 (6) ◽  
pp. 1169 ◽  
Author(s):  
Nicola A. Pascarelli ◽  
Antonella Fioravanti ◽  
Elena Moretti ◽  
Giacomo M. Guidelli ◽  
Lucia Mazzi ◽  
...  
Keyword(s):  
Mitochondrial Function ◽  
In Vitro Study ◽  
Human Sperm ◽  
Dna Integrity ◽  
Sperm Function ◽  
Sperm Viability ◽  
Tnf Α ◽  
The Impact

Tumour necrosis factor (TNF)-α is primarily involved in the regulation of cell proliferation and apoptosis; in addition it possesses pro-inflammatory properties. Anti-TNF-α strategies involve either administration of anti-TNF-α antibody or soluble TNF receptor to mop up circulating TNF-α. Etanercept, a recombinant human TNF-α receptor, was found to be effective in the treatment of rheumatoid arthritis. The impact of TNF-α inhibitors on human fertility is of notable interest. This in vitro study investigated the effect of different concentrations of TNF-α and etanercept used alone or in combination on sperm viability, motility, mitochondrial function, percentage of apoptosis and chromatin integrity in swim-up selected human spermatozoa. A negative effect of TNF-α (300 and 500 ng mL–1) and etanercept (from 800 µg mL–1 to 2000 µg mL–1) individually on sperm viability, motility, mitochondrial function, percentage of apoptotic spermatozoa and sperm DNA integrity was demonstrated. However, at concentrations of 100 and 200 µg mL–1, etanercept can block, in a significant way, the toxic effects of TNF-α (500 ng mL–1) on studied sperm characteristics. Our results confirm that TNF-α has a detrimental effect on sperm function and suggest, for the first time, that etanercept may counteract the in vitro toxic action of TNF-α. This data appears to be quite promising, although further studies, both in vivo and in vitro, are needed to understand the exact mechanism of action of TNF-α and TNF-α antagonists on sperm function.

scholarly journals Dexmedetomidine extraction by the extracorporeal membrane oxygenation circuit: results from an in vitro study

Perfusion ◽  
2019 ◽  
Vol 35 (3) ◽  
pp. 209-216 ◽  
Author(s):  
Samantha H Dallefeld ◽  
Jennifer Sherwin ◽  
Kanecia O Zimmerman ◽  
Kevin M Watt
Keyword(s):  
Extracorporeal Membrane Oxygenation ◽  
Drug Exposure ◽  
In Vitro Study ◽  
Drug Degradation ◽  
Membrane Oxygenation ◽  
Life Threatening ◽  
Patient At Risk ◽  
The Impact

Background: Dexmedetomidine is a sedative administered to minimize distress and decrease the risk of life threatening complications in children supported with extracorporeal membrane oxygenation. The extracorporeal membrane oxygenation circuit can extract drug and decrease drug exposure, placing the patient at risk of therapeutic failure. Objective: To determine the extraction of dexmedetomidine by the extracorporeal membrane oxygenation circuit. Materials and methods: Dexmedetomidine was studied in three closed-loop circuit configurations to isolate the impact of the oxygenator, hemofilter, and tubing on circuit extraction. Each circuit was primed with human blood according to standard practice for Duke Children’s Hospital, and flow was set to 1 L/min. Dexmedetomidine was dosed to achieve a therapeutic concentration of ~600 pg/mL. Dexmedetomidine was added to a separate tube of blood to serve as a control and evaluate for natural drug degradation. Serial blood samples were collected over 24 hours and concentrations were quantified with a validated assay. Drug recovery was calculated at each time point. Results: Dexmedetomidine was highly extracted by the oxygenator evidenced by a mean recovery of 62-67% at 4 hours and 23-34% at 24 hours in circuits with an oxygenator in-line. In contrast, mean recovery with the oxygenator removed was 96% at 4 hours and 93% at 24 hours. Dexmedetomidine was stable over time with a mean recovery in the control samples of 102% at 24 hours. Conclusion: These results suggest dexmedetomidine is extracted by the oxygenator in the extracorporeal membrane oxygenation circuit which may result in decreased drug exposure in vivo.

scholarly journals Leakage of Microbial Endotoxin through the Implant-Abutment Interface in Oral Implants: An In Vitro Study

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Rhoodie Garrana ◽  
Govindrau Mohangi ◽  
Paulo Malo ◽  
Miguel Nobre
Keyword(s):  
In Vitro Study ◽  
Endotoxin Level ◽  
Oral Implants ◽  
E Coli ◽  
Implant Abutment ◽  
The Mean ◽  
The Impact ◽  
External Connections

Background. Endotoxin initiates osteoclastic activity resulting in bone loss. Endotoxin leakage through implant abutment connections negatively influences peri-implant bone levels.Objectives. (i) To determine if endotoxin can traverse different implant-abutment connection (IAC) designs; (ii) to quantify the amount of endotoxins traversing the IAC; (iii) to compare the in vitro comportments of different IACs.Materials and Methods. Twenty-seven IACs were inoculated withE. coliendotoxin. Six of the twenty-seven IACs were external connections from one system (Southern Implants) and the remaining twenty-one IACs were made up of seven internal IAC types from four different implant companies (Straumann, Ankylos, and Neodent, Southern Implants).Results. Of the 27 IACs tested, all 6 external IACs leaked measurable amounts of endotoxin. Of the remaining 21 internal IACs, 9 IACs did not show measurable leakage whilst the remaining 12 IACs leaked varying amounts. The mean log endotoxin level was significantly higher for the external compared to internal types (p=0.015).Conclusion. Within the parameters of this study, we can conclude that endotoxin leakage is dependent on the design of the IAC. Straumann Synocta, Straumann Cross-fit, and Ankylos displayed the best performances of all IACs tested with undetectable leakage after 7 days. Each of these IACs incorporated a morse-like component in their design. Speculation still exists over the impact of IAC endotoxin leakage on peri-implant tissues in vivo; hence, further investigations are required to further explore this.

scholarly journals Constitutive or Induced HIF-2 Addiction is Involved in Resistance to Anti-EGFR Treatment and Radiation Therapy in HNSCC

Cancers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1607 ◽  
Author(s):  
Coliat ◽  
Ramolu ◽  
Jégu ◽  
Gaiddon ◽  
Jung ◽  
...  
Keyword(s):  
Treatment Failure ◽  
Tumor Progression ◽  
Mammalian Target Of Rapamycin ◽  
Hypoxia Inducible Factor ◽  
Growth Factor Receptor ◽  
Clonogenic Survival ◽  
Primary Resistance ◽  
Egfr Inhibition

Background: management of head and neck squamous cell carcinomas (HNSCC) include anti-Epidermal Growth Factor Receptor (EGFR) antibodies and radiotherapy, but resistance emerges in most patients. RAS mutations lead to primary resistance to EGFR blockade in metastatic colorectal cancer but are infrequent in HNSCC, suggesting that other mechanisms are implicated. Since hypoxia and Hypoxia Inducible Factor-1 (HIF-1) have been associated with treatment failure and tumor progression, we hypothesized that EGFR/mammalian Target Of Rapamycin (mTOR)/HIF-1 axis inhibition could radiosensitize HNSCC. Methods: We treated the radiosensitive Cal27 used as control, and radioresistant SQ20B and UD-SCC1 cells, in vivo and in vitro, with rapamycin and cetuximab before irradiation and evaluated tumor progression and clonogenic survival. Results: Rapamycin and cetuximab inhibited the mTOR/HIF-1α axis, and sensitized the SQ20B cell line to EGFR-inhibition. However, concomitant delivery of radiation to SQ20B xenografts increased tumor relapse frequency, despite effective HIF-1 inhibition. Treatment failure was associated with the induction of HIF-2α expression by cetuximab and radiotherapy. Strikingly, SQ20B and UD-SCC1 cells clonogenic survival dropped <30% after HIF-2α silencing, suggesting a HIF-2-dependent mechanism of oncogenic addiction. Conclusions: altogether, our data suggest that resistance to EGFR inhibition combined with radiotherapy in HNSCC may depend on tumor HIF-2 expression and underline the urgent need to develop novel HIF-2 targeted treatments.

scholarly journals GliPR1 knockdown by RNA interference exerts anti‐glioma effects in vitro and in vivo

2021 ◽  
Author(s):  
Urban J. Scheuring ◽  
Steffi Ritter ◽  
Daniel Martin ◽  
Gabriele Schackert ◽  
Achim Temme ◽  
...  
Keyword(s):  
Rna Interference ◽  
Nude Mice ◽  
Cellular Proliferation ◽  
Glioma Cells ◽  
Clonogenic Survival ◽  
Tumor Bearing ◽  
Shrna Vector ◽  
Induced Apoptosis

Abstract Introduction In human glioblastomas, glioma pathogenesis-related protein1 (GliPR1) is overexpressed and appears to be an oncoprotein. We investigated whether GliPR1 knockdown in glioma cells by RNA interference exerts anti-glioma effects. Methods Experiments used human glioblastoma cell lines transduced with GliPR1 shRNA (sh#301, sh#258). Transduction produced stringent doxycycline-dependent GliPR1 knockdown in clones (via lentiviral “all-in-one” TetOn-shRNA vector) or stable GliPR1 knockdown in polyclonal cells (via constitutive retroviral-shRNA vector). In vitro assessments included cellular proliferation and clonogenic survival. In vivo assessments in tumor-bearing nude mice included tumor growth and survival. Results Using doxycycline-dependent GliPR1 knockdown, shGliPR1-transduced U87-MG clones demonstrated reductions in cellular proliferation in the presence versus absence of doxycycline. Using stable GliPR1 knockdown, polyclonal shGliPR1-transduced U87-MG, A172, and U343-MG cells consistently showed decreased clonogenic survival and induced apoptosis (higher proportion of early apoptotic cells) compared to control shLuc-transduced cells. In tumor-bearing nude mice, using doxycycline-dependent GliPR1 knockdown, subcutaneous and cranial transplantation of the U87-MG clone 980-5 (transduced with GliPR1 sh#301) resulted in reduced subcutaneous tumor volume and cerebral tumor area in doxycycline-treated mice versus those left untreated. Using stable GliPR1 knockdown, nude mice cranially transplanted with polyclonal U87-MG cells transduced with GliPR1 sh#258 had significantly prolonged survival compared to mice cranially transplanted with control shLuc-transduced cells (41 versus 26 days; P < 0.001). Conclusion GliPR1 knockdown in glioma cells decreased cellular proliferation, decreased clonogenic survival, and induced apoptosis in vitro, and reduced glioblastoma tumor growth and prolonged survival in vivo. These findings support that GliPR1 may have potential value as a therapeutic target.

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