Project description:Although it has been shown that HIF1 and 2 fulfill essential roles within the hematopoietic system and in the regulation of HSC fate, little is currently known about the specific mechanisms that are involved. We identified transcriptome changes induced by hypoxia, constitutively active HIF1(P402/564) and HIF2(P405/531) in human cord blood CD34+ cells. Thus, we were able to identify common hypoxia-HIF1-HIF2 gene signatures, but we also identified specific target genes that were exclusively regulated by HIF1, HIF2 or hypoxia.
Project description:Although it has been shown that HIF1 and 2 fulfill essential roles within the hematopoietic system and in the regulation of HSC fate, little is currently known about the specific mechanisms that are involved. We identified transcriptome changes induced by hypoxia, constitutively active HIF1(P402/564) and HIF2(P405/531) in human cord blood CD34+ cells. Thus, we were able to identify common hypoxia-HIF1-HIF2 gene signatures, but we also identified specific target genes that were exclusively regulated by HIF1, HIF2 or hypoxia. CB CD34+ cells were isolated by Miltenyi miniMACS column. Cells were prestimulated in HPGM with 100 ng/ml KITL, FLT3L and TPO for 48 hrs. Cells were transduced with control pRRL-IRS2-EGFP lentiviral vectors or vectors expressing HIF1α(P402A,P564A) or HIF2α(P405A,P531A) in one or two rounds of 12 hrs each. 24 hrs later transduced cells were sorted after which RNA was isolated. 5 independent CB CD34+ batches were isolated, transduced and sorted, and isolated RNA was combined and used for Illumina beadhchip arrays HT12 v4
Project description:Although it has been shown that HIF1 and 2 fulfill essential roles within the hematopoietic system and in the regulation of HSC fate, little is currently known about the specific mechanisms that are involved. We identified transcriptome changes induced by hypoxia, constitutively active HIF1(P402/564) and HIF2(P405/531) in human cord blood CD34+ cells. Thus, we were able to identify common hypoxia-HIF1-HIF2 gene signatures, but we also identified specific target genes that were exclusively regulated by HIF1, HIF2 or hypoxia.
Project description:Although it has been shown that HIF1 and 2 fulfill essential roles within the hematopoietic system and in the regulation of HSC fate, little is currently known about the specific mechanisms that are involved. We identified transcriptome changes induced by hypoxia, constitutively active HIF1(P402/564) and HIF2(P405/531) in human cord blood CD34+ cells. Thus, we were able to identify common hypoxia-HIF1-HIF2 gene signatures, but we also identified specific target genes that were exclusively regulated by HIF1, HIF2 or hypoxia. CB CD34+ cells were isolated by Miltenyi miniMACS column. Cells were prestimulated in HPGM with 100 ng/ml KITL, FLT3L and TPO for 3 days after which cells were placed either at normoxia or hypoxia (1% O2 for an additional 24 hrs). 5 independent CB CD34+ batches were used and isolated RNA was combined and used for Illumina beadhchip arrays HT12 v4
Project description:While the functions of hypoxia-inducible factor 1? (HIF1?)/aryl hydrocarbon receptor nuclear translocator (ARNT) and HIF2?/ARNT (HIF2) proteins in activating hypoxia-inducible genes are well established, the role of other transcription factors in the hypoxic transcriptional response is less clear. We report here for the first time that the basic helix-loop-helix-leucine-zip transcription factor upstream stimulatory factor 2 (USF2) is required for the hypoxic transcriptional response, specifically, for hypoxic activation of HIF2 target genes. We show that inhibiting USF2 activity greatly reduces hypoxic induction of HIF2 target genes in cell lines that have USF2 activity, while inducing USF2 activity in cells lacking USF2 activity restores hypoxic induction of HIF2 target genes. Mechanistically, USF2 activates HIF2 target genes by binding to HIF2 target gene promoters, interacting with HIF2? protein, and recruiting coactivators CBP and p300 to form enhanceosome complexes that contain HIF2?, USF2, CBP, p300, and RNA polymerase II on HIF2 target gene promoters. Functionally, the effect of USF2 knockdown on proliferation, motility, and clonogenic survival of HIF2-dependent tumor cells in vitro is phenocopied by HIF2? knockdown, indicating that USF2 works with HIF2 to activate HIF2 target genes and to drive HIF2-depedent tumorigenesis.
Project description:Malignant melanoma is characterized by a propensity for early lymphatic and hematogenous spread. The hypoxia-inducible factor (HIF) family of transcription factors is upregulated in melanoma by key oncogenic drivers. HIFs promote the activation of genes involved in cancer initiation, progression, and metastases. Hypoxia has been shown to enhance the invasiveness and metastatic potential of tumor cells by regulating the genes involved in the breakdown of the ECM as well as genes that control motility and adhesion of tumor cells. Using a Pten-deficient, Braf-mutant genetically engineered mouse model of melanoma, we demonstrated that inactivation of HIF1? or HIF2? abrogates metastasis without affecting primary tumor formation. HIF1? and HIF2? drive melanoma invasion and invadopodia formation through PDGFR? and focal adhesion kinase-mediated (FAK-mediated) activation of SRC and by coordinating ECM degradation via MT1-MMP and MMP2 expression. These results establish the importance of HIFs in melanoma progression and demonstrate that HIF1? and HIF2? activate independent transcriptional programs that promote metastasis by coordinately regulating cell invasion and ECM remodeling.
Project description:CB CD34+ cells were were transduced with control (tNGFR) or CITED2 overexpression lentivectors, or control (shSCR) or shRNA CITED2 lentivectors and mRNA was isolated in order to investigate global gene expression changes upon perturbation of CITED2.
Project description:CB CD34+ cells were were transduced with control (tNGFR) or CITED2 overexpression lentivectors, or control (shSCR) or shRNA CITED2 lentivectors and mRNA was isolated in order to investigate global gene expression changes upon perturbation of CITED2. CB CD34+ cells were isolated by Miltenyi miniMACS column. Cells were prestimulated in HPGM with 100 ng/ml KITL, FLT3L and TPO for 12 hrs. Cells were transduced with control (tNGFR) or CITED2 overexpression lentivectors, or control (shSCR) shRNA CITED2 lentivectors, in three rounds over 48 hrs. Transduced cells were sorted after which RNA was isolated for Illumina beadhchip arrays HT12 v4.