SHARP1 suppresses breast cancer metastasis by promoting degradation of hypoxia-inducible factors
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE33950 | GEO | 2012/07/19
SECONDARY ACCESSION(S): PRJNA150029
REPOSITORIES: GEO
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Project description:Triple Negative Breast cancer accounts for some of the most aggressive types of breast cancer. By interrogating clinical datasets, we found that the activities of p63 and Hypoxia-Inducible-Factors (HIFs), two master regulators of the invasive and metastatic cancer cell phenotype are linked in TNBC through the p63-target Sharp1. Mechanistically, Sharp1 promotes HIF-1α/HIF-2α proteasomal degradation by serving as HIFs presenting factor to the proteasome independently from oxygen levels and prior ubiquitination. To investigate unbiasedly if Sharp1 is a general inhibitor of HIF induced transcriptional program, we compared the transcriptomic profile of cells either overexpressing Sharp1 or depleted of HIF1a and HIF2a. We collected RNA from control MDA-MB-231 cells (shGFP) or MDA-MB-231 cells overexpressing Sharp1 or MDA-MB-231 cells depleted of HIF1a and HIF2a (shHIF). Cells were left untreated in normal culturing conditions before harvesting. Samples were then processed for total RNA extraction and hybridization on Affymetrix microarrays. Four biological replicas (A, B, C, D) were used for each of the 4 conditions (1: shGFP, control cells; 2: shHIF cells; 3: Sharp1-overexpressing cells) for a total of 12 samples.
2012-07-18 | E-GEOD-33950 | biostudies-arrayexpress
Project description:Mutational inactivation of VHL is the earliest genetic event in the majority of ccRCCs, leading to activation of the HIF-1α and HIF-2α transcription factors. While correlative studies of human ccRCCs and functional studies using human ccRCC cell lines have implicated HIF-1α as an inhibitor and HIF-2α as a promoter of aggressive tumour behaviours, their roles in tumour onset have not been functionally addressed. Using an autochthonous ccRCC model, we show genetically that Hif1a is necessary for tumour formation whereas Hif2a deletion has only minor effects on tumour initiation and growth. Both HIF-1α and HIF-2α are necessary for the clear cell phenotype. Transcriptomic and proteomic analyses revealed that HIF-1α regulates glycolysis while HIF-2α regulates genes associated with lipoprotein metabolism, ribosome biogenesis and E2F and MYC transcriptional activities. Deficiency of HIF-2α increased CD8+ T cell infiltration and activation. These studies reveal different functions of HIF-1α and HIF-2α in ccRCC. SIGNIFICANCE The roles of HIF-1α and HIF-2α in ccRCC pathogenesis remain unclear. Using a mouse genetic approach we show that HIF-1α but not HIF-2α is important for tumour formation, contrary to predictions from studies of human ccRCC. We show that HIF-1α and HIF-2α transcriptionally regulate different aspects of metabolism and identify HIF-2α as a suppressor of immune cell infiltration and activation.
2020-07-02 | PXD016630 | Pride
Project description:Inflammation is a significant risk factor for colon cancer. Recent work has demonstrated essential roles for several infiltrating immune populations in the metaplastic progression following inflammation. Hypoxia and stabilization of hypoxia-inducible factors (HIFs) are hallmark features of inflammation and solid tumors. Previously, we demonstrated an important role for tumor epithelial HIF-2α in colon tumors; however, the function of epithelial HIF-2α as a critical link in the progression of inflammation to cancer has not been elucidated. In colitis-associated colon cancer models, epithelial HIF-2α was essential in tumor growth. Concurrently, epithelial disruption of HIF-2α significantly decreased neutrophils in the colon tumor microenvironment. Intestinal epithelial HIF-2α-overexpressing mice demonstrated that neutrophil recruitment was a direct response to increased epithelial HIF-2α signaling. High-throughput RNA sequencing (RNA-seq) analysis of HIF-2α-overexpressing mice in conjunction with data mining from the Cancer Genome Atlas showed that the neutrophil chemokine CXCL1 gene was highly upregulated in colon tumor epithelium in a HIF-2α-dependent manner. Using selective peptide inhibitors of the CXCL1-CXCR2 signaling axis identified HIF-2α-dependent neutrophil recruitment as an essential mechanism to increase colon carcinogenesis. These studies demonstrate that HIF-2α is a novel regulator of neutrophil recruitment to colon tumors and that it is essential in shaping the protumorigenic inflammatory microenvironment in colon cancer.
2021-04-27 | GSE173363 | GEO
Project description:Growing number of cancer (stem) cells and stem cells were described to accommodate constituent active HIF-2α under normoxia. Previous study of hypoxia effect may have obscured some of normoxic HIF-2α functions as hypoxia inducible features. Our interest in study of protective potential of HIFs in lung cells led us to discover pseudohypoxia functions of HIF-2α under normoxia in human bronchial epithelial cells which exhibit pluripotency related markers and features. Our study provided perspective to pseudohypoxia functions of HIF-2α via enrichment of de novo motifs. In addition to the C-TAD, the N-TAD of HIF-2α was found to contribute to targeting on these non-canonical loci. Further elucidation of pseudohypoxia mechanism could resolve its implication of malignancy or pluripotency.
2016-07-06 | GSE81635 | GEO
Project description:Transcriptomic analysis of nucleus pulposus (NP) tissues from intervertebral discs of 14- and 24-month-old mice with the conditional postnatal overexpression of HIF-2α. Hypoxia-inducible factors (HIFs) are essential for the homeostasis of the hypoxic tissues, and therefore, increased activity of the transcription factor HIF-2α is shown to contribute to the pathogenesis of mild disc degeneration in the spine. We examined the transcriptomic profiles of nucleus pulposus cells in control and K19-HIF-2α-dPA overexpression mice using microarrays.
2024-03-27 | GSE249908 | GEO
Project description:Forkhead box A1 (FOXA1) is a pioneer factor that facilitates chromatin binding and function of lineage-specific and oncogenic transcription factors. Here, we have demonstrated that FOXA1 overexpression in estrogen receptor-positive breast cancer cells drives genome-wide enhancer reprogramming to activate pro-metastatic transcriptional programs. We have identified the hypoxia-inducible transcription factor HIF-2α as the top FOXA1-engaged super-enhancer target induced by FOXA1 overexpression, activating pro-metastatic gene signatures associated with poor breast cancer outcome. Using two different siRNA sequences, we identified 917 and 1,107 genes commonly down- and up-regulated (FDR < 0.05), respectively, upon HIF-2α knockdown in tamoxifen-resistant MCF7L cells. The enriched GO terms of the down-regulated genes were predominantly linked to tumor metastatic traits. GSEA showed that this HIF-2α-dependent gene set was significantly enriched in the transcriptomes of the TCGA ER+ breast tumors expressing high HIF-2α, but not high HIF-1α. We show the selective efficacy of a HIF-2α antagonist (PT2385), currently in clinical trial for renal cell carcinoma, in repressing migration and clonogenicity of endocrine-resistant breast cancer cells expressing high FOXA1. Our study suggests that targeting HIF-2α is a new approach blocking the aberrant transcriptional programs under high FOXA1-induced enhancer reprogramming in treating endocrine-resistant and metastatic breast cancer.
2019-12-18 | GSE124655 | GEO
Project description:Hyperactivation of Notch signaling and the cellular hypoxic response are frequently observed in cancers, with increasing reports of connections to tumor initiation and progression. The two signaling mechanisms are known to intersect, but while it is well established that hypoxia regulates Notch signaling, less is known about whether Notch can regulate the cellular hypoxic response. We now report that Notch signaling specifically controls expression of HIF2a, a key mediator of the cellular hypoxic response. Transcriptional upregulation of HIF2a by Notch under normoxic conditions leads to elevated HIF2a protein levels in primary breast cancer cells as well as in human breast cancer, medulloblastoma and renal cell carcinoma cell lines. The elevated level of HIF2a protein was in certain tumor cell types accompanied by down-regulation of HIF1a protein levels, indicating that high Notch signaling may drive a HIF1a-to-HIF2a switch. At the transcriptome level, the presence of HIF2a was required for approximately 21% of all Notch-induced genes: among the 1062 genes that were upregulated by Notch in medulloblastoma cells during normoxia, upregulation was abrogated in 227 genes when HIF2a expression was knocked down by HIF2a siRNA. In conclusion, our data show that Notch signaling affects the hypoxic response via regulation of HIF2a, which may be important for future cancer therapies.
2018-04-19 | GSE113353 | GEO
Project description:Hyperactivation of Notch signaling and the cellular hypoxic response are frequently observed in cancers, with increasing reports of connections to tumor initiation and progression. The two signaling mechanisms are known to intersect, but while it is well established that hypoxia regulates Notch signaling, less is known about whether Notch can regulate the cellular hypoxic response. We now report that Notch signaling specifically controls expression of HIF2a, a key mediator of the cellular hypoxic response. Transcriptional upregulation of HIF2a by Notch under normoxic conditions leads to elevated HIF2a protein levels in primary breast cancer cells as well as in human breast cancer, medulloblastoma and renal cell carcinoma cell lines. The elevated level of HIF2 protein was in certain tumor cell types accompanied by down-regulation of HIF1a protein levels, indicating that high Notch signaling may drive a HIF1a-to-HIF2a switch. At the transcriptome level, the presence of HIF2a was required for approximately 21% of all Notch-induced genes: among the 1062 genes that were upregulated by Notch in medulloblastoma cells during normoxia, upregulation was abrogated in 227 genes when HIF2a expression was knocked down by HIF2a siRNA. In conclusion, our data show that Notch signaling affects the hypoxic response via regulation of HIF2a, which may be important for future cancer therapies.
2018-04-28 | GSE113753 | GEO
Project description:To investigate the detailed molecular mechanisms for the regulatory role of HIF-2α in experimental colitis, microarray gene expression analysis was performed on colon RNA isolated from 6- to 8-week-old Hif-2αF/F, Hif-2αlΔIE mice treated with 3%DSS for 3 days. Background & Aims: Hypoxic inflammation is characterized by decreased oxygen tension in inflammatory foci, and is a notable feature in inflammatory bowel disease (IBD). Hypoxic response is mediated by transcription factors hypoxia-inducible factor (HIF)-1α and HIF-2α, both of which are highly induced in IBD. HIF-1α is a protective factor that limits intestinal barrier dysfunction during inflammation. However, the role of HIF-2α has not been assessed in hypoxic inflammation and IBD. Methods: A hypoxia reporter mouse model was used to test the presence of hypoxia and HIF-2α in dextran sulfate sodium (DSS) and Citrobacter rodentium (C.rod)-induced colitis. The role of HIF-2α in these mouse models of colitis was further assessed in mice with an intestinal epithelium-specific gain- and loss-of-function of HIF-2α. Results: Induction of hypoxia and HIF-2α was confirmed in both murine experimental colitis models and human IBD samples. Disruption of HIF-2α attenuated colonic inflammation whereas stabilization of HIF-2α potentiated inflammation in mouse models of colitis. Interestingly, intestine specific overexpression of HIF-2α but not HIF-1α leads to spontaneous colitis and premature death in mice. Further mechanistic analysis showed that HIF-2α is a driver for pro-inflammatory response and is critical regulator of intestinal epithelial-derived tumor necrosis factor (TNF)-α. Blocking TNF-α completely ameliorated HIF-2α potentiated intestinal inflammation. Conclusions: These data demonstrate that HIF-2α is a critical transcription factor essential in intestinal epithelium elicited inflammatory response. Global gene expression profiling in colon RNAs isolated from 7-week-old Hif-2αF/F (n=6, Shah 007) and Hif-2αΔIE (n=5, Shah 008).
2013-02-28 | E-GEOD-43416 | biostudies-arrayexpress
Project description:Mutational inactivation of VHL is the earliest genetic event in the majority of clear cell renal cell carcinomas (ccRCC), leading to accumulation of the HIF-1alpha and HIF-2a transcription factors. While correlative studies of human ccRCC and functional studies using human ccRCC cell lines have implicated HIF-1a as an inhibitor and HIF-2a as a promoter of aggressive tumour behaviours, their roles in tumour onset have not been functionally addressed. Using an autochthonous ccRCC model, we show genetically that Hif1a is essential for tumour formation whereas Hif2a deletion has only minor effects on tumour initiation and growth. Both HIF-1a and HIF-2a are required for the clear cell phenotype. Transcriptomic and proteomic analyses revealed that HIF-1alpha regulates glycolysis while HIF-2a regulates genes associated with lipoprotein metabolism, ribosome biogenesis and E2F and MYC transcriptional activities. HIF-2a-deficient tumours were characterised by increased antigen presentation, interferon signalling and CD8+ T cell infiltration and activation. Single copy loss of HIF1A or high levels of HIF2A mRNA expression correlated with altered immune microenvironment in human ccRCC. These studies reveal an oncogenic role of HIF-1alpha in ccRCC initiation and suggest that alterations in the balance of HIF-1alpha and HIF-2a activities can affect different aspects of ccRCC biology and disease aggressiveness.
2020-05-22 | GSE150983 | GEO