Deregulation of HIF-Responsive Demethylases Causes Synthetic Lethality Between the VHL Tumor Suppressor Gene and the EZH1 Histone Methyltransferase
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE70767 | GEO | 2015/10/10
SECONDARY ACCESSION(S): PRJNA289629
REPOSITORIES: GEO
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Project description:Inactivation of the von Hippel-Lindau tumor suppressor protein (pVHL) is the signature lesion in the most common form of kidney cancer, clear cell renal cell carcinoma (ccRCC). pVHL loss causes the transcriptional activation of hypoxia-inducible factor (HIF) target genes, including many genes that encode histone lysine demethylases. Moreover, chromatin regulators are frequently mutated in this disease. We found that ccRCC displays increased H3K27 acetylation and a shift toward mono- or unmethylated H3K27 caused by an HIF-dependent increase in H3K27 demethylase activity. Using a focused short hairpin RNA library, as well as CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 (CRISPR-associated protein 9) and a pharmacological inhibitor, we discovered that pVHL-defective ccRCC cells are hyperdependent on the H3K27 methyltransferase EZH1 for survival. Therefore, targeting EZH1 could be therapeutically useful in ccRCC.
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Project description:HIF-2alpha is essential for (VHL-/-) ccRCC subcutaneous tumor growth in mice, and in tumor cell lines, its inhibition results in increased ROS accumulation, tumor cell death and responsiveness to radiation treatment. We have utilized transcriptional profiling to screen for putative HIF-2alpha targets genes that serve an anti-oxidant and, thus, cell survival function. A498 ccRCC cell line was treated with control siRNA or mixture of two HIF-2alpha specific siRNA for 48 hours, and RNA was harvested. 4 independent experiments were performed, and expression was compared between control and HIF-2alpha knockdown groups. 8 total samples were applied to Affymetrix Human Gene 1.0 ST Arrays. We performed two-class paired analysis using Significance Analysis of Microarrays (SAM) software to compare expression in the CT (control siRNA) and H2 (Hif2-alpha siRNA) groups.
2009-08-27 | E-GEOD-16622 | biostudies-arrayexpress
Project description:HIF-2alpha is essential for (VHL-/-) ccRCC subcutaneous tumor growth in mice, and in tumor cell lines, its inhibition results in increased ROS accumulation, tumor cell death and responsiveness to radiation treatment. We have utilized transcriptional profiling to screen for putative HIF-2alpha targets genes that serve an anti-oxidant and, thus, cell survival function. A498 ccRCC cell line was treated with control siRNA or mixture of two HIF-2alpha specific siRNA for 48 hours, and RNA was harvested. 4 independent experiments were performed, and expression was compared between control and HIF-2alpha knockdown groups.
2009-08-27 | GSE16622 | GEO
Project description:Inactivation of the von Hippel-Lindau tumor suppressor gene, VHL, is an archetypical tumor-initiating event in clear cell renal carcinoma (ccRCC) that leads to the activation of hypoxia-inducible transcription factors (HIFs). However, VHL mutation status in ccRCC is not correlated with clinical outcome. Here we show that during ccRCC progression, cancer cells exploit diverse epigenetic alterations to empower a branch of the VHL-HIF pathway for metastasis, and the strength of this activation is associated with poor clinical outcome. By analyzing metastatic subpopulations of VHL-deficient ccRCC cells, we discovered an epigenetically altered VHL-HIF response that is specific to metastatic ccRCC. Focusing on the two most prominent pro-metastatic VHL-HIF target genes, we show that loss of polycomb repressive complex 2 (PRC2)-dependent histone H3 Lys27 trimethylation (H3K27me3) activates HIF-driven chemokine (C-X-C motif) receptor 4 (CXCR4) expression in support of chemotactic cell invasion, whereas loss of DNA methylation enables HIF-driven cytohesin 1 interacting protein (CYTIP) expression to protect cancer cells from death cytokine signals. Thus, metastasis in ccRCC is based on an epigenetically expanded output of the tumor-initiating pathway. This SuperSeries is composed of the SubSeries listed below. Refer to individual Series.
2012-12-05 | E-GEOD-32299 | biostudies-arrayexpress
Project description:Inactivation of the von Hippel-Lindau tumor suppressor gene, VHL, is an archetypical tumor-initiating event in clear cell renal carcinoma (ccRCC) that leads to the activation of hypoxia-inducible transcription factors (HIFs). However, VHL mutation status in ccRCC is not correlated with clinical outcome. Here we show that during ccRCC progression, cancer cells exploit diverse epigenetic alterations to empower a branch of the VHL-HIF pathway for metastasis, and the strength of this activation is associated with poor clinical outcome. By analyzing metastatic subpopulations of VHL-deficient ccRCC cells, we discovered an epigenetically altered VHL-HIF response that is specific to metastatic ccRCC. Focusing on the two most prominent pro-metastatic VHL-HIF target genes, we show that loss of polycomb repressive complex 2 (PRC2)-dependent histone H3 Lys27 trimethylation (H3K27me3) activates HIF-driven chemokine (C-X-C motif) receptor 4 (CXCR4) expression in support of chemotactic cell invasion, whereas loss of DNA methylation enables HIF-driven cytohesin 1 interacting protein (CYTIP) expression to protect cancer cells from death cytokine signals. Thus, metastasis in ccRCC is based on an epigenetically expanded output of the tumor-initiating pathway. This SuperSeries is composed of the SubSeries listed below.
2012-12-05 | GSE32299 | GEO
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:Inactivation of the VHL tumor suppressor gene is the signature initiating event in clear cell renal cell carcinoma (ccRCC), the most common form of kidney cancer, and causes the accumulation of hypoxia-inducible factor 2α (HIF-2α). HIF-2α inhibitors are effective in some ccRCC cases, but both de novo and acquired resistance have been observed in the laboratory and in the clinic. Here, we identified synthetic lethality between decreased activity of cyclin-dependent kinases 4 and 6 (CDK4/6) and VHL inactivation in two species (human and Drosophila) and across diverse human ccRCC cell lines in culture and xenografts. Although HIF-2α transcriptionally induced the CDK4/6 partner cyclin D1, HIF-2α was not required for the increased CDK4/6 requirement of VHL-/- ccRCC cells. Accordingly, the antiproliferative effects of CDK4/6 inhibition were synergistic with HIF-2α inhibition in HIF-2α-dependent VHL-/- ccRCC cells and not antagonistic with HIF-2α inhibition in HIF-2α-independent cells. These findings support testing CDK4/6 inhibitors as treatments for ccRCC, alone and in combination with HIF-2α inhibitors.
| S-EPMC6913182 | biostudies-literature
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
Project description:Inactivation of the von Hippel-Lindau tumor suppressor gene, VHL, is an archetypical tumor-initiating event in clear cell renal carcinoma (ccRCC) that leads to the activation of hypoxia-inducible transcription factors (HIFs). However, VHL mutation status in ccRCC is not correlated with clinical outcome. Here we show that during ccRCC progression, cancer cells exploit diverse epigenetic alterations to empower a branch of the VHL-HIF pathway for metastasis, and the strength of this activation is associated with poor clinical outcome. By analyzing metastatic subpopulations of VHL-deficient ccRCC cells, we discovered an epigenetically altered VHL-HIF response that is specific to metastatic ccRCC. Focusing on the two most prominent pro-metastatic VHL-HIF target genes, we show that loss of polycomb repressive complex 2 (PRC2)-dependent histone H3 Lys27 trimethylation (H3K27me3) activates HIF-driven chemokine (C-X-C motif) receptor 4 (CXCR4) expression in support of chemotactic cell invasion, whereas loss of DNA methylation enables HIF-driven cytohesin 1 interacting protein (CYTIP) expression to protect cancer cells from death cytokine signals. Thus, metastasis in ccRCC is based on an epigenetically expanded output of the tumor-initiating pathway. Gene expression data from metastatic 786-M1A cells with and without reintroduced HA-VHL. The empty vector, pBabe-puro, was used as control.
2012-12-05 | E-GEOD-32297 | biostudies-arrayexpress
Project description:Inactivation of the von Hippel-Lindau tumor suppressor gene, VHL, is an archetypical tumor-initiating event in clear cell renal carcinoma (ccRCC) that leads to the activation of hypoxia-inducible transcription factors (HIFs). However, VHL mutation status in ccRCC is not correlated with clinical outcome. Here we show that during ccRCC progression, cancer cells exploit diverse epigenetic alterations to empower a branch of the VHL-HIF pathway for metastasis, and the strength of this activation is associated with poor clinical outcome. By analyzing metastatic subpopulations of VHL-deficient ccRCC cells, we discovered an epigenetically altered VHL-HIF response that is specific to metastatic ccRCC. Focusing on the two most prominent pro-metastatic VHL-HIF target genes, we show that loss of polycomb repressive complex 2 (PRC2)-dependent histone H3 Lys27 trimethylation (H3K27me3) activates HIF-driven chemokine (C-X-C motif) receptor 4 (CXCR4) expression in support of chemotactic cell invasion, whereas loss of DNA methylation enables HIF-driven cytohesin 1 interacting protein (CYTIP) expression to protect cancer cells from death cytokine signals. Thus, metastasis in ccRCC is based on an epigenetically expanded output of the tumor-initiating pathway.
2012-12-05 | GSE32297 | GEO