The Hira complex regulates Gli3R-dependent transcription in Hedgehog signaling and medulloblastoma cell growth and migration
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE291945 | GEO | 2025/03/18
REPOSITORIES: GEO
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Project description:Regulation of the Hedgehog pathway activity may be supported by coactivators and corepresors of its main effectors- Gli transcription factors. While activation processes are well studied, repression mechanisms remain elusive. We identified chromatin remodelling complex Hira to interact with Gli3R protein, showed that its loss-of-function changes Hh pathway activity, and examined possible mechanism behind the observed effect. We also established that Hira influences the viability and migratory abilities of Hh-dependent medulloblastoma Daoy cells. Our study paves the way for a better understanding of processes involved in Hh pathway regulation and Hh-dependent carcinogenesis.
2025-03-18 | GSE291915 | GEO
Project description:Aberrant activation of Hedgehog (HH) signaling has been identified as a key etiologic factor of many human malignancies. Signal strength, target gene specificity, and oncogenic activity of HH signaling profoundly depend on interactions with other pathways such as epidermal growth factor receptor-mediated signaling which has been shown to cooperate with HH/GLI in basal cell carcinoma and pancreatic cancer. We demonstrate that the human medulloblastoma cell line Daoy possesses a fully inducible endogenous HH pathway. Treatment of Daoy cells with Sonic Hedgehog or Smoothened agonist induced expression of GLI1 protein and prevented processing of GLI3 to its repressor form. To study interactions between HH- and EGF-induced signaling in greater detail, time-resolved measurements were carried out and analyzed on the transcriptomic as well as proteomic level. Daoy cells responded to the co-treatment by downregulating GLI1, PTCH, and HHIP on the transcript level which was also seen when Amphiregulin (AREG) was used instead of EGF. The finding that EGFR signaling silences proteins acting as negative regulators of HH signaling is firstly described here as a novel crosstalk mechanism. Furthermore, combined EGFR/HH signaling maintains high GLI1 protein levels contrasting its downregulation on the transcript level. On the other hand, high level synergism was observed with respect to a strong and significant upregulation of numerous canonical EGF-targets with putative tumor-promoting properties such as MMP7, VEGFA, and IL-8. In conclusion, synergistic effects between EGFR and HH signaling can selectively induce a switch from a canonical HH/GLI profile to a modulated specific target gene profile pointing to more wide-spread, yet context-dependent, interactions between HH/GLI and growth factor receptor signaling in human malignancies. To study interactions between HH- and EGF-induced signaling, time-resolved measurements were carried out over a period of 24 h at 14 different time points after stimulation by EGF with and without additional stimulation by SHH. Furthermore, as a control, cells without any stimulation by EGF and SHH (control) and cells in the presents of SHH were analyzed. Overall, three biological replicates of 60 different treatment/timepoints were analyzed yielding 180 different samples.
2014-07-31 | E-GEOD-46045 | biostudies-arrayexpress
Project description:Aberrant activation of Hedgehog (HH) signaling has been identified as a key etiologic factor of many human malignancies. Signal strength, target gene specificity, and oncogenic activity of HH signaling profoundly depend on interactions with other pathways such as epidermal growth factor receptor-mediated signaling which has been shown to cooperate with HH/GLI in basal cell carcinoma and pancreatic cancer. We demonstrate that the human medulloblastoma cell line Daoy possesses a fully inducible endogenous HH pathway. Treatment of Daoy cells with Sonic Hedgehog or Smoothened agonist induced expression of GLI1 protein and prevented processing of GLI3 to its repressor form. To study interactions between HH- and EGF-induced signaling in greater detail, time-resolved measurements were carried out and analyzed on the transcriptomic as well as proteomic level. Daoy cells responded to the co-treatment by downregulating GLI1, PTCH, and HHIP on the transcript level which was also seen when Amphiregulin (AREG) was used instead of EGF. The finding that EGFR signaling silences proteins acting as negative regulators of HH signaling is firstly described here as a novel crosstalk mechanism. Furthermore, combined EGFR/HH signaling maintains high GLI1 protein levels contrasting its downregulation on the transcript level. On the other hand, high level synergism was observed with respect to a strong and significant upregulation of numerous canonical EGF-targets with putative tumor-promoting properties such as MMP7, VEGFA, and IL-8. In conclusion, synergistic effects between EGFR and HH signaling can selectively induce a switch from a canonical HH/GLI profile to a modulated specific target gene profile pointing to more wide-spread, yet context-dependent, interactions between HH/GLI and growth factor receptor signaling in human malignancies.
2014-07-31 | GSE46045 | GEO
Project description:The Hedgehog (Hh) pathway is essential for tissue homeostasis, and misregulation of this cascade drives several cancers. To control expression of pathway target genes, the G protein-coupled receptor (GPCR) Smoothened (SMO) activates glioma-associated (GLI) transcription factors via an unknown mechanism. Here we show that, rather than conforming to traditional GPCR signaling paradigms, SMO activates GLI by binding and sequestering protein kinase A (PKA) catalytic subunits at the membrane. This sequestration, triggered by GPCR kinase 2 (GRK2)-mediated phosphorylation of SMO intracellular domains, prevents PKA from phosphorylating soluble substrates, releasing GLI from PKA-mediated inhibition. Our work provides a mechanism directly linking vertebrate Hh signal transduction at the membrane to transcription factor activation in the nucleus. In contrast to existing models, our work shows that this aspect of Hh signaling is fundamentally similar between species. The mechanism described here may apply broadly to other GPCR- and PKA-containing cascades.
2021-04-25 | PXD019346 | Pride
Project description:ZNF521 is a transcription co-factor with recognized regulatory functions in haematopoietic, osteo-adipogenic and neural progenitor cells. Among its diverse activities, ZNF521 has been implicated in the regulation of medulloblastoma (MB) cells, where the Hedgehog (HH) pathway, has a key role in the development of normal cerebellum and of a substantial fraction of MBs. Here a functional cross-talk is shown for ZNF521 with the HH pathway, where it interacts with GLI1 and GLI2, the major HH transcriptional effectors and enhances the activity of HH signalling. In particular, ZNF521 cooperates with GLI1 and GLI2 in the transcriptional activation of GLI (glioma-associated transcription factor)-responsive promoters. This synergism is dependent on the presence of the N-terminal, NuRD-binding motif in ZNF521, and is sensitive to HDAC (histone deacetylase) and GLI inhibitors. Taken together, these results highlight the role of ZNF521, and its interaction with the NuRD complex, in determining the HH response at the level of transcription. This may be of particular relevance in HH-driven diseases, especially regarding the MBs belonging to the SHH (sonic HH) subgroup where a high expression of ZNF521 is correlated with that of HH pathway components.
2020-10-03 | GSE158925 | GEO
Project description:The Hedgehog signaling pathway is essential for the maintenance and response of several types of stem cells. To study the transcriptional response of stem cells to HH signaling, we searched for proteins binding to GLI proteins, the transcriptional effectors of the HH pathway in mouse embryonic stem (ES) cells. We purified GLI protein complex from an ES cell line that contained a tamoxifen-inducible 3XFLAG-tagged GLI3 repressor allele by anti-FLAG immunoprecipitation and several novel GLI co-factors were identified in the complex by subsequent mass spectrometry analysis.
2016-02-04 | PXD002494 | Pride
Project description:Purpose: Most Hedgehog responsive gene expression is mediated through GLI de-repression. Additionally GLI -repression is proposed to play roles in limb pre-patterning before HH pathway activation. This study evaluates if GLI repression is established prior to HH pathway activation. Methods: To determine if GLI-repression is established prior to pathway activation, we used genomic approaches to study GLI-mediated repression using the mouse developing limb as a model. We identified pre-HH (E9.25, 21-23S) and post-HH (E10.5, 32-25S) GLI3 binding regions using CUT&RUN for endogenous FLAG-tagged GLI3 proteins. Using a combination of ChIP-seq, CUT&RUN, CUT&Tag, ATAC-seq and RNA-seq, we tested whether loss of Gli3 prior to HH signaling was able to de-repress genes and enhancers, as it does after HH signaling. Results: Prior to HH signaling, GLI3 binds to poised, accessible regions with histone deacetylase (HDAC) proteins, similar to post-HH signaling. Despite GLI3 binding to most regions as it does in the post-HH limb, loss of Gli3 is unable to prematurely active target genes or enhancers. Furthermore, we find that GLI3-dependent chromatin compaction does not occur until roughly 10 hours after HH signaling would have normally been induced. Collectively, these results support that GLI repressor proteins are inert prior to HH pathway activation.
2022-01-21 | GSE178838 | GEO
Project description:Single cell technologies hold promise for resolving complex early developmental phenotypes. Here we define a novel Hedgehog (Hh)-Fibroblast Growth Factor (FGF) signaling axis for the formation of anterior mesoderm lineages during gastrulation. Single-cell transcriptome analysis of Hh-deficient mesoderm revealed selective deficits in anterior mesoderm populations—culminating in defects to anterior embryonic structures including the pharyngeal arches, heart, and anterior somites. Transcriptional profiling of Hh-deficient mesoderm during gastrulation revealed disruptions to both transcriptional patterning of the mesoderm and FGF signaling for mesoderm migration. Mesoderm-specific Fgf4/Fgf8 double mutants recapitulated anterior mesoderm defects and Hh-dependent GLI transcription factors modulated enhancers at FGF gene loci. Cellular migration defects during gastrulation induced by Hh pathway antagonism were mitigated by FGF4 protein. These findings implicate a multicomponent signaling hierarchy activated by Hh ligands from the embryonic node and executed by FGF signals in nascent mesoderm to control anterior mesoderm patterning.
2020-06-23 | GSE149335 | GEO
Project description:Despite Hedgehog’s influence on T-cell activation and proliferation, the transcriptional targets of Gli2 in lymphocytes are not known. We therefore examined the Hedgehog-dependent transcriptional response of resting and early-stage activated T-cells in order to define their transcriptional response to Hedgehog pathway activation. We have established transgenic models where transcription of target genes by Gli2 is either constitutively activated or repressed in cells of the T-lineage. Gli2 has an N-terminal repressor domain and a C-terminal activator domain. Lck-Gli2?N2 (Gli2A) mice carry a transgene encoding a truncated form of Gli2 that acts as a permanent transcriptional activator of Hh target genes. Conversely, Lck-Gli2?C2 (Gli2R) mice express a repressor of Gli2-dependent transcription, which by binding to Gli binding sites inhibits physiological Hh-dependent transcription, and hence Hh signal transduction, in the cell. These transgenes are driven by the Lck promoter and are only expressed in T-lineage cells Purified fresh, resting CD4 cells (unstimulated) and from CD4 cells stimulated with anti-CD3/CD28 for 6h (stimulated) were analysed in order to obtain transcriptional profiles before and during the early stages of T-cell activation.
2013-01-01 | E-GEOD-33156 | biostudies-arrayexpress
Project description:Sutherlandia frutescens (L) R. Br. (Sutherlandia) is a South African botanical that is traditionally used to treat a variety of health conditions, infections and diseases, including cancer. We hypothesized Sutherlandia might act through Gli/ Hedgehog (Hh)-signaling in prostate cancer cells and used RNA-Seq transcription profiling to profile gene expression in TRAMPC2 murine prostate cancer cells with or without Sutherlandia extracts. We found 50% of Hh-responsive genes can be repressed by Sutherlandia ethanol extract, including the canonical Hh-responsive genes Gli1 and Ptch1 as well as newly distinguished Hh-responsive genes Hsd11b1 and Penk.
2016-12-07 | GSE75760 | GEO