BET inhibition abrogates global transcription via repressing m6A writer complex
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE219191 | GEO | 2023/12/31
REPOSITORIES: GEO
Similar Datasets
Project description:To set the relevance of BRD4 as repressor, we performed gene expression profile by RNA-seq in A375 treated with BETi JQ1 to identify potential BRD4 target genes.
2021-03-31 | E-MTAB-8649 | biostudies-arrayexpress
Project description:Targeting the epigenome to modulate gene expression programs driving cancer development has emerged as an exciting avenue for therapeutic intervention. Pharmacological inhibition of the bromodomain and extraterminal (BET) family of chromatin adapter proteins has proven effective in this regard, suppressing growth of diverse cancer types mainly through downregulation of the c-MYC oncogene and its downstream transcriptional program. While initially effective, resistance to BET inhibitors (BETi) typically occurs through mechanisms that reactivate MYC expression. We have previously shown that lung adenocarcinoma (LAC) is inhibited by JQ1 through suppression of FOSL1, suggesting that the epigenetic landscape of tumor cells from different origins and differentiation states influences BETi response. Here, we assessed how these differences affect mechanisms of BETi resistance through the establishment of isogenic pairs of JQ1 sensitive and resistant LAC cell lines. We found that resistance to JQ1 in LAC occurs independent of FOSL1 while MYC levels remain unchanged between resistant cells and their JQ1 treated parental counterparts. Furthermore, while epithelial-mesenchymal transition (EMT) is observed upon resistance, TGF- induced EMT did not confer resistance in JQ1 sensitive LAC lines, suggesting this is a consequence, rather than a driver of BETi resistance in our model systems. Importantly, siRNA knockdown demonstrated that JQ1 resistant cell lines are still dependent on BRD4 expression and we found that phosphorylation of BRD4 is elevated in resistant LACs, identifying casein kinase 2 (CK2) as a candidate protein mediating this effect. Inhibition of CK2, as well as downstream transcriptional targets of phosphorylated BRD4 - including AXL and activators of the PI3K pathway - synergize with JQ1 to inhibit BETi resistant LAC. Overall, this demonstrates that the mechanism of resistance to BETi varies depending on cancer type, with LAC cells developing JQ1 resistance independent of MYC re-activation, and identifying CK2 phosphorylation of BRD4 as a potential target to overcome resistance in this cancer.
2021-04-07 | GSE164813 | GEO
Project description:Small molecule BET bromodomain inhibitors (BETi) are actively being pursued in clinical trials for the treatment of a variety of cancers, however, the mechanisms of resistance to targeted BET protein inhibitors remain poorly understood. Using a novel mass spectrometry approach that globally measures kinase signaling at the proteomic level, we evaluated the response of the kinome to targeted BET inhibitor treatment in a panel of BRD4-dependent ovarian carcinoma (OC) cell lines. Despite initial inhibitory effects of BETi, OC cells acquired resistance following sustained treatment with the BETi, JQ1. Through application of Multiplexed Inhibitor Beads (MIBs) and mass spectrometry, we demonstrate that BETi resistance is mediated by adaptive kinome reprogramming, where activation of compensatory pro-survival kinase networks overcomes BET protein inhibition. Furthermore, drug combinations blocking these kinases may prevent or delay the development of drug resistance and enhance the efficacy of BET inhibitor therapy. RNAseq was employed to identify changes in kinase RNA expression following short term (48h) or chronic (JQ1R) JQ1 treatment in three different ovarian cancer cell lines.
2016-07-21 | E-GEOD-82329 | biostudies-arrayexpress
Project description:The bromodomain and extra terminal domain (BET) family of proteins, including BRD2, BRD3, and BRD4, play a key role in many cellular processes, including inflammatory gene expression, mitosis, and viral/host interaction by controlling the assembly of histone acetylation-dependent chromatin complexes. Previous studies have shown that multiple BET inhibitors (BETi), including JQ1, have therapeutic effects in cancer and cardiovascular diseases. Some BETi have entered different phases of clinical trials. Pharmacologically, JQ1 functions by displacing BET proteins from chromatin by competitively binding to the acetyl-lysine recognition pocket of BET bromodomains. JQ1 has been used as a chemical probe to investigate the role of BET bromodomains in the transcriptional regulation of cardiovascular diseases. For example, JQ1 has been shown to attenuates inflammation and experimental atherosclerosis (Mol Cell. 2014 Oct 23; 56(2): 219–231.). JQ1 has also recently been shown to reduce EndoMT and cardiac fibrosis (J Mol Cell Cardiol. 2019 Feb;127:83-96.). However, the molecular targets of JQ1 dependent or independent of BRD4 remains unknown. To depict the transcriptomic signature of JQ1 in human endothelial cells, we observed a vasoprotective and atheroprotective transcriptome by JQ1 treatment using genome-wide RNA-seq based transcriptomic profiling. JQ1 is a magic bullet in cardiovascular disease prevention. Further elucidation of new molecular targets of JQ1 will lead to the identification of potentially new therapeutic targets to treat cardiovascular diseases.
2019-11-27 | GSE137500 | GEO
Project description:We report the application of MeRIP sequencing technology for high-throughput profiling of m6A methylome in breast cancer cells. Comparison of m6A methylome between METTL3-WT and METTL3-K177Q reconstituting cells revealed the following findings: 1) Significant global alteration of methylation sites due to K177Q mutation (termed as KQ-m6A signature). 2) GO analysis of the differential m6A-MeRIP candidates enriched pathways involved in chromatin modification, RNA splicing, DNA damage, cell cycle, and autophagy, consistent with a critical role of m6A-mediated nuclear biological activities and highlighted generally recognized cellular events associated with tumorigenesis. 3) we dissected potential mechanistic clues explaining the attenuated invasive phenotype in METTL3K177Q reconstituting cells.
2022-09-20 | GSE183014 | GEO
Project description:BET inhibition abrogates global transcription via repressing m6A writer complex
| PRJNA907370 | ENA
Project description:Bromodomain and extraterminal motif (BET) inhibitors, such as JQ1, are promising cancer therapeutics that target epigenetic regulators, particularly BRD4. However, resistance to BET inhibitors (BETi) limits their clinical utility, necessitating a better understanding of adaptive mechanisms. We identified BRD2 upregulation as a conserved response to BET inhibition across multiple cancer types and hypothesized that BRD2 compensates for BRD4 loss, sustaining essential transcriptional programs during treatment. Consistent with this, BRD2 knockdown sensitized cancer cells to BETi in vitro, and combining BRD2 depletion and JQ1 treatment significantly impaired tumor growth in vivo. At the chromatin level, BRD2 and BRD4 ChIP-seq analysis of pancreatic cancer cells showed consistent BRD4 loss from chromatin after JQ1 treatment, while BRD2 displacement differed by sensitivity. Resistant cells maintained higher BRD2 occupancy than sensitive cells, suggesting a link between BRD2 retention and drug response. To dissect the underlying mechanism of BRD2 upregulation upon BET inhibition, we analyzed co-expression networks and observed that NFYA is co-expressed with BRD2 across diverse tissues and cancer types. Consistently, NFYA binds the BRD2 promoter. NFYA depletion abrogated BRD2 upregulation upon BETi treatment, indicating that NFYA is required for BRD2 induction following BET inhibition. Collectively, our findings establish BRD2 as a critical mediator of adaptive resistance to BETi in pan-cancer and identify NFYA as a novel transcriptional regulator of this process. Co-targeting BRD2 or its regulatory network offers a rational strategy to enhance the durability and efficacy of BET-based therapies.
2026-04-29 | GSE307284 | GEO
Project description:Bromodomain and extraterminal motif (BET) inhibitors, such as JQ1, are promising cancer therapeutics that target epigenetic regulators, particularly BRD4. However, resistance to BET inhibitors (BETi) limits their clinical utility, necessitating a better understanding of adaptive mechanisms. We identified BRD2 upregulation as a conserved response to BET inhibition across multiple cancer types and hypothesized that BRD2 compensates for BRD4 loss, sustaining essential transcriptional programs during treatment. Consistent with this, BRD2 knockdown sensitized cancer cells to BETi in vitro, and combining BRD2 depletion and JQ1 treatment significantly impaired tumor growth in vivo. At the chromatin level, BRD2 and BRD4 ChIP-seq analysis of pancreatic cancer cells showed consistent BRD4 loss from chromatin after JQ1 treatment, while BRD2 displacement differed by sensitivity. Resistant cells maintained higher BRD2 occupancy than sensitive cells, suggesting a link between BRD2 retention and drug response. To dissect the underlying mechanism of BRD2 upregulation upon BET inhibition, we analyzed co-expression networks and observed that NFYA is co-expressed with BRD2 across diverse tissues and cancer types. Consistently, NFYA binds the BRD2 promoter. NFYA depletion abrogated BRD2 upregulation upon BETi treatment, indicating that NFYA is required for BRD2 induction following BET inhibition. Collectively, our findings establish BRD2 as a critical mediator of adaptive resistance to BETi in pan-cancer and identify NFYA as a novel transcriptional regulator of this process. Co-targeting BRD2 or its regulatory network offers a rational strategy to enhance the durability and efficacy of BET-based therapies.
2026-04-29 | GSE307285 | GEO
Project description:Atherosclerosis is an important pathological factor in the development of cardiovascular diseases. In addition to increased plasma lipid concentrations, irregular/oscillatory shear stress and inflammatory processes trigger pathophysiological changes. Inhibitors of the transcription modulatory bromo- and extra-terminal domain (BET) protein family (BETi) could offer a possible therapeutic approach due to their anti-inflammatory properties. In this study, the influence of laminar shear stress, inflammation and BETi on human endothelial cells in an atherosclerosis in vitro model was investigated using global protein expression profiling. For this purpose, human umbilical cord derived vascular endothelial cells (HUVEC) were treated with TNFα to mimic the inflammatory condition and were exposed to 24h laminar shear stress in the presence or absence of a BRD4 inhibitor, JQ1. Data-independent acquisition mass spectrometry (DIA-MS) alloqed us to quantify 3316 proteins for further statistical analysis. Differentially regulated proteins indicate a clear influence of inflammation and shear stress on human endothelial cells. Overall, application of JQ1 is led to significant changes in the proteome, including a strong anti-inflammatory response as well as a potentially negative impact on atherosclerosis formation. To our knowledge, this is the first proteomics study on HUVEC which investigates the influence of shear stress and BET inhibition in TNFα inflammatory endothelial cell culture model.
2022-10-30 | PXD035842 | Pride
Project description:N⁶-methyladenosine (m6A) and its reader, writer, and eraser (RWE) proteins assume crucial roles in regulating the splicing, stability, and translation of mRNA. To our knowledge, no systematic investigations have been conducted about the crosstalk between m6A and other modified nucleosides in RNA. Herein, we modified our recently established liquid chromatography-parallel-reaction monitoring (LC-PRM) method by incorporating stable isotope-labeled (SIL) peptides as internal or surrogate standards for profiling epitranscriptomic RWE proteins. We were able to detect reproducibly a total of 114 RWE proteins in HEK293T cells with the genes encoding m6A eraser proteins (i.e., ALKBH5, FTO) and the catalytic subunit of the major m6A writer complex (i.e., METTL3) being individually ablated. Notably, eight proteins were altered by more than 1.5-fold in the opposite directions in HEK293T cells depleted of METTL3 and ALKBH5. Analysis of published m6A mapping results revealed the presence of m6A in the corresponding mRNAs of four of these proteins. Together, we integrated SIL peptides into our LC-PRM method for quantifying epitranscriptomic RWE proteins, and our work revealed potential crosstalks between m6A and other epitranscriptomic modifications. Our modified LC-PRM method with the use of SIL peptides should be applicable for high-throughput profiling of epitranscriptomic RWE proteins in other cell types and in tissues.
2022-09-24 | PXD036032 | Pride