Transcriptional differences in breast cancer cells exposed to acute versus chronic hypoxia.
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE240211 | GEO | 2023/09/01
REPOSITORIES: GEO
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Project description:To determine hypoxia mediated changes in whole blood, normal C57Bl/10 mice were gradually exposed to a chronic hypoxic environment, equivalent to an altitude of 6500m, for 2 weeks in vivo. Control, age-matched mice were maintained under normoxic, normobaric conditions by exposing them to ambient air in Philadelphia (c. 50 mts above sea level). Purpose: To determine the expression profile of genes differentially expressed in mouse whole blood upon exposure to normobaric hypoxia in vivo. Methods: The hypoxic group consisting of 6 C57/BL10 mice was exposed to normobaric hypoxia, in a specially designed and hermetically closed hypoxic chamber, using a gas mixing system Pegas 4000 MF (Columbus Instruments, Ohio, USA). The oxygen level was decreased from 21% to 8% over a period of 14 days. 6 control mice were kept at normal oxygen and pressure levels by exposing them to ambient air in Philadelphia (c. 50 mts above sea level). RNA from whole blood was isolated, processed and used for microarray-based expression profiling. Profiles were generated for genes differentially expressed at control versus normobaric hypoxia in whole blood using a false discovery rate (FDR) of 0%. The Profile was validated by real-time quantitative reverse transcription-polymerase chain reaction (qPCR) on 2 biologically independent samples, not used for generating the profile. Results: The transcriptomes associated with normobaric hypoxia in whole blood were identified. We found 4723 genes that were differentially expressed in normobaric hypoxic whole blood compared to control with a 0% FDR and a 2 fold cutoff. Conclusion: Transcriptome level differences exist in the whole blood of animals subjected to normobaric hypoxia. Our definition of the normobaric hypoxia blood transcriptome provides insight into the functioning and response to hypoxia in whole blood.
2010-05-07 | E-GEOD-15894 | biostudies-arrayexpress
Project description:Intratumoral hypoxia causes the formation of dysfunctional blood vessels which contribute to tumor metastasis. Blood vessels are embedded in the tumor stroma where cancer-associated fibroblasts (CAFs) constitute the most prominent cellular component. We found that hypoxic human mammary CAFs promote blood vessel growth in CAF-endothelial cell co-cultures in vitro. Mass spectrometry-based proteomic analysis of CAF secretome unravels how hypoxic CAFs contribute to blood vessel abnormalities by altering the secretion of a multitude of pro- and anti-angiogenic factors. Hypoxia induces pronounced remodeling of the CAF proteome, including proteins that have not been previously related to this process. Our study provides a map of unprecedented depth of hypoxia-induced molecular alterations in mammary CAFs that can be exploited to identify novel mechanisms that control hypoxic CAF functions.
2019-02-15 | PXD006535 | Pride
Project description:Intratumoral hypoxia causes the formation of dysfunctional blood vessels which contribute to tumor metastasis. Blood vessels are embedded in the tumor stroma where cancer-associated fibroblasts (CAFs) constitute the most prominent cellular component. We found that hypoxic human mammary CAFs promote blood vessel growth in CAF-endothelial cell co-cultures in vitro. Mass spectrometry-based proteomic analysis of CAF secretome unravels how hypoxic CAFs contribute to blood vessel abnormalities by altering the secretion of a multitude of pro- and anti-angiogenic factors. Hypoxia induces pronounced remodeling of the CAF proteome, including proteins that have not been previously related to this process. Amongst those, the uncharacterized antisense gene protein NCBP2-AS2 is one of the most transcriptionally upregulated proteins in the proteome and secretome of hypoxic CAFs. Silencing of NCBP2-AS2 abrogates the pro-angiogenic function acquired by hypoxic CAFs through decreasing VEGF expression levels to the levels found in normoxic CAFs.
2019-02-15 | PXD006539 | Pride
Project description:Hypoxia is a condition in which tissues of the body do not receive sufficient amounts of oxygen supply. The current study aimed to clarify the impact of a forced low-oxygen environment on the early pregnancy by exposing mice to low-oxygen conditions for 72 hours after fertilization. The treatment resulted in a complete failure of blastocyst implantation accompanied by vascular hypermeability in the uterus. The transcriptome analysis of uterus and ovary revealed remarkable alterations in gene expression between the control normoxic and hypoxic treatment groups. These alterations were encompassed a number of genes categorized to the immune responses and oxidative demethylation process.
2023-11-19 | GSE244610 | GEO
Project description:Hypoxia is an important driver of cancer progression, and rapidly growing tumors often result in intratumoral hypoxic regions. Hypoxia is associated with metabolic reprogramming and angiogenesis, resulting in enhanced tumor progression. Here, we aimed to study breast cancer hypoxia responses at the proteomic level, and we wanted to identify differences in protein secretion from luminal-like and basal-like cell lines before and after hypoxia.
2023-06-23 | PXD027136 | Pride
Project description:Gene expression analysis in human bronchial epithelial cells expressing wild type EGFR or activating mutations, L858R or E7646-E750 EGFR in a normoxic environment (21% oxygen) or at 24 hours of exposure to a hypoxic environment (0.1% oxygen). The effect of EGFR mutations on base-line and hypoxia-induced gene expression was determined.
2017-03-02 | GSE95564 | GEO
Project description:How cancer cells adapt to hypoxia during tumor development remains an important question. The hypothesis tested in the present study was that tumor cell-derived exosome vesicles (also known as microvesicles or extracellular vesicles) are mediators of hypoxia-dependent intercellular signaling in glioblastoma (GBM), i.e. highly aggressive brain tumors characterized by hypoxia and a vascular density that is among the highest of all human malignancies. In vitro hypoxia experiments and studies with patient materials reveal the enrichment in exosomes of hypoxia-regulated mRNAs and proteins, several of which were associated with poor patient prognosis. We show that cancer cell exosomes mediate hypoxia-dependent, phenotypic modulation of stromal cells in vitro and ex vivo, resulting in accelerated GBM tumor angiogenesis and growth in mice. These data suggest that exosomes constitute potent mediators of hypoxia-driven tumor development, and circulating multiparameter biomarkers of tumor hypoxia. U87 MG glioblastoma cells were grown at normoxic (21% oxygen) or hypoxic (1% oxygen) conditions for 48 hours. Conditioned media from normoxic and hypoxic cells were then used to isolate exosomes by differential centrifugation. Both cells and exosomes were lysed in Trizol reagent, and RNA was isolated.Total RNA from all samples (four types of samples in three biological repilicates) was subjected to genome-wide transcriptional analysis with Illumina HumanHT-12 V3.0 expression beadchip. Gene expression profile obtained from hypoxic U87 MG glioblastoma cells was compared to the profile of normoxic control cells. Analogically, gene expression profile obtained from hypoxic U87 MG cells was compared to the profile of exosomes secreted by normoxic U87 MG cells.
2013-03-20 | E-GEOD-45301 | biostudies-arrayexpress
Project description:Hypoxia is an important condition in the tumor cell microenvironment and approximately 1-1.5% of the genome is transcriptionally responsive to hypoxia with hypoxia-inducible factor-1 (HIF-1) as a major mediator of transcriptional activation. Tumor hypoxia is associated with a more aggressive phenotype of many cancers in adults, but data on pediatric tumors are scarce. By immunohistochemical analysis, HIF-1α expression was readily detectable in 18/28 primary Ewing´s sarcoma family tumors (ESFT), a group of highly malignant bone-associated tumors in children and young adults, which encouraged us to study the effect of hypoxia on ESFT cell lines in vitro. Many tumors are profoundly hypoxic and multiple studies have demonstrated that hypoxic tumors have a poorer prognosis than non-hypoxic tumors. The cellular adaptations of cancer cells to hypoxia have been shown to profoundly influence transcriptional regulation. Intriguingly, we found that EWS-FLI1 protein expression, which characterizes ESFT, is up-regulated by hypoxia in a HIF-1α-dependent manner. Hypoxia modulated the EWS-FLI1 transcriptional signature relative to normoxic conditions. Both synergistic as well as antagonistic transcriptional effects of EWS-FLI1 and of hypoxia were observed. Consistent with alterations in the expression of metastasis related genes, hypoxia stimulated the invasiveness and soft-agar colony formation of ESFT cells in vitro. Our data represents the first transcriptome analysis of hypoxic ESFT cells and identifies hypoxia as an important microenvironmental factor modulating EWS-FLI1 expression and target gene activity with far-reaching consequences for the malignant properties of ESFT. Keywords: Consequences on gene expression of hypoxic condition created by exposure of cells to 1% oxygen in a hypoxia chamber.
2010-05-26 | GSE19197 | GEO
Project description:We used HeLa cells that overexpress GFP-tagged SRSF6 (4-fold) were grown in normal conditions (Normoxia, 21% oxygen) or hypoxic conditions (Hypoxia, 0.2% oxygen). compared the binding pattern of SRSF6 between normoxia, 4h hypoxia and 24h hypoxia.
2023-01-03 | GSE198308 | GEO
Project description:Hypermethylation of tumor suppressor gene (TSG) promoters confers growth advantages to cancer cells, but how these changes arise is poorly understood. Here, we report that tumor hypoxia reduces the activity of oxygen-dependent TET enzymes, which catalyze DNA de-methylation through 5-methylcytosine oxidation. This occurs independently of hypoxia-associated alterations in TET gene expression, basal metabolism, HIF activity or nuclear reactive oxygen species, but directly depends on oxygen shortage. Hypoxia-induced loss of TET activity increases hypermethylation at gene promoters in vitro, while also in patients, gene promoters are markedly more methylated in hypoxic than normoxic tumors. Affected genes are frequently involved in DNA repair, cell cycle regulation, angiogenesis and metastasis, indicating cellular selection of hypermethylation events. Overall, up to 50% of the tumor-associated hypermethylation is ascribable to hypoxia across various cancer types. Accordingly, spontaneous murine breast tumors become hypermethylated when rendered hypoxic through vessel pruning, whereas vessel normalisation rescues this effect. Tumor hypoxia thus acts as a novel regulator underlying DNA methylation.
2016-09-01 | GSE71402 | GEO