Search results for "hypoxia-inducible factor"
showing 10 items of 83 documents
Cholesterol Starvation and Hypoxia Activate the FVII Gene via the SREBP1-GILZ Pathway in Ovarian Cancer Cells to Produce Procoagulant Microvesicles
2019
AbstractInteraction between the transcription factors, hypoxia-inducible factor (HIF1α and HIF2α) and Sp1, mediates hypoxia-driven expression of FVII gene encoding coagulation factor VII (fVII) in ovarian clear cell carcinoma (CCC) cells. This mechanism is synergistically enhanced in response to serum starvation, a condition possibly associated with tumor hypoxia. This transcriptional response potentially results in venous thromboembolism, a common complication in cancer patients by producing procoagulant extracellular vesicles (EVs). However, which deficient serum factors are responsible for this characteristic transcriptional mechanism is unknown. Here, we report that cholesterol deficien…
Long Non Coding RNA H19: A New Player in Hypoxia-Induced Multiple Myeloma Cell Dissemination
2019
The long non-coding RNA H19 (lncH19) is broadly transcribed in the first stage of development and silenced in most cells of an adult organism
Recruitment of HIF-1α and HIF-2α to common target genes is differentially regulated in neuroblastoma: HIF-2α promotes an aggressive phenotype
2006
In neuroblastoma specimens, HIF-2alpha but not HIF-1alpha is strongly expressed in well-vascularized areas. In vitro, HIF-2alpha protein was stabilized at 5% O2 (resembling end capillary oxygen conditions) and, in contrast to the low HIF-1alpha activity at this oxygen level, actively transcribed genes like VEGF. Under hypoxia (1% O2), HIF-1alpha was transiently stabilized and primarily mediated acute responses, whereas HIF-2alpha protein gradually accumulated and governed prolonged hypoxic gene activation. Knockdown of HIF-2alpha reduced growth of neuroblastoma tumors in athymic mice. Furthermore, high HIF-2alpha protein levels were correlated with advanced clinical stage and high VEGF expr…
Mechanism of leptin expression in breast cancer cells: role of hypoxia-inducible factor-1α
2007
We reported previously that the obesity hormone leptin is overexpressed in breast cancer biopsies. Here, we investigated molecular mechanisms involved in this process, focusing on conditions that are associated with obesity, that is, hyperinsulinemia and induction of hypoxia. By using quantitative real-time PCR, immunofluorescent detection of proteins and enzyme-linked immunosorbent assays, we found that treatment of MCF-7 breast cancer cells with high doses of insulin or the hypoxia-mimetic agent CoCl2, or culturing the cells under hypoxic conditions significantly increased the expression of leptin mRNA and protein. Notably, the greatest leptin mRNA and protein expression were observed und…
Role of reactive oxygen species in the regulation of HIF-1 by prolyl hydroxylase 2 under mild hypoxia
2012
The function and survival of eukaryotic cells depends on a constant and sufficient oxygen supply. Cells recognize and respond to hypoxia by accumulation of the transcription factor hypoxia-inducible factor 1 (HIF-1), composed of an oxygen-sensitive HIF-1α and a constitutive HIF-1β subunit. Besides physiology, HIF-1 induction is involved in major pathological processes such as cardiovascular disease, inflammation and cancer, which are associated with the formation of reactive oxygen species (ROS). ROS have been reported to affect HIF-1 activity but the role for ROS in regulating HIF-1 has not been definitely settled. In order to shed light on the redox-regulation of HIF-1 by ROS, we studied …
Hypoxia-inducible factor 1Α may regulate the commitment of mesenchymal stromal cells toward angio-osteogenesis by mirna-675-5P
2017
Abstract Background aims During bone formation, angiogenesis and osteogenesis are regulated by hypoxia, which is able to induce blood vessel formation, as well as recruit and differentiate human mesenchymal stromal cells (hMSCs). The molecular mechanisms involved in HIF-1α response and hMSC differentiation during bone formation are still unclear. This study aimed to investigate the synergistic role of hypoxia and hypoxia-mimetic microRNA miR-675-5p in angiogenesis response and osteo-chondroblast commitment of hMSCs. Methods By using a suitable in vitro cell model of hMSCs (maintained in hypoxia or normoxia), the role of HIF-1α and miR-675-5p in angiogenesis and osteogenesis coupling was inv…
In Vivo Modulation of Angiogenesis and Immune Response on a Collagen Matrix via Extracorporeal Shockwaves
2020
The effective management of tissue integration and immunological responses to transplants decisively co-determines the success of soft and hard tissue reconstruction. The aim of this in vivo study was to evaluate the eligibility of extracorporeal shock wave therapy (ESWT) with respect to its ability to modulate angiogenesis and immune response to a collagen matrix (CM) for tissue engineering in the chorioallantoic membrane (CAM) assay, which is performed with fertilized chicken eggs. CM were placed on the CAM on embryonic development day (EDD) 7
The hypoxia-inducible factor-responsive proteins semaphorin 4D and vascular endothelial growth factor promote tumor growth and angiogenesis in oral s…
2012
Growth and metastasis of solid tumors requires induction of angiogenesis to ensure the delivery of oxygen, nutrients and growth factors to rapidly dividing transformed cells. Through either mutations, hypoxia generated by cytoreductive therapies, or when a malignancy outgrows its blood supply, tumor cells undergo a change from an avascular to a neovascular phenotype, a transition mediated by the hypoxia-inducible factor (HIF) family of transcriptional regulators. Vascular endothelial growth factor (VEGF) is one example of a gene whose transcription is stimulated by HIF. VEGF plays a crucial role in promoting tumor growth and survival by stimulating new blood vessel growth in response to suc…
Hypoxia Positively Regulates the Expression of pH-Sensing G-Protein–Coupled Receptor OGR1 (GPR68)
2016
Background & Aims: A novel family of proton-sensing G-proteinâcoupled receptors, including ovarian cancer G-proteinâcoupled receptor 1 (OGR1) (GPR68) has been identified to play a role in pH homeostasis. Hypoxia is known to change tissue pH as a result of anaerobic glucose metabolism through the stabilization of hypoxia-inducible factor-1α. We investigated how hypoxia regulates the expression of OGR1 in the intestinal mucosa and associated cells. Methods: OGR1 expression in murine tumors, human colonic tissue, and myeloid cells was determined by quantitative reverse-transcription polymerase chain reaction. The influence of hypoxia on OGR1 expression was studied in monocytes/macrophages and…
miR-31-5p Is a LIPUS-Mechanosensitive MicroRNA that Targets HIF-1α Signaling and Cytoskeletal Proteins
2019
The roles of low-intensity pulsed ultrasound (LIPUS) and microRNAs (miRNAs) on hMSCs commitments have already been investigated