Next Generation Sequencing of mouse melanoma tumors generated with a repressible BRAF construct
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE152722 | GEO | 2020/07/15
REPOSITORIES: GEO
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Project description:Purpose: The goals of this study are to compare NGS-derived transciptomes from human melanoma cell lines before and after vemurafenib in order to compare to a mouse model of melanoma using doxycycline that permits control of mutant BRAF expression. Treatment with doxycycline leads to loss of mutant BRAF expression and tumor regression, but tumors reoccur after a prolonged period of dormancy. Results: We found conserved expression changes in histone methyltransferase genes (HMT), including Enhancer Of Zeste 2 Polycomb Repressive Complex 2 Subunit (EZH2), Suppressor Of Variegation 3-9 Homolog 1(SUV39H1), Suppressor Of Variegation 3-9 Homolog 2 (SUV39H2), ASH2 Like, Histone Lysine Methyltransferase Complex Subunit (ASH2L), SET And MYND Domain Containing 2 (SYMD2), and Protein arginine methyltransferase 5 (PRMT5) and histone deacetylases (HDACs) HDACS 7, 9,10, and 11.
2020-07-15 | GSE152699 | GEO
Project description:SMYD lysine methyltransferases target histones and non-histone proteins for methylation and are critical regulators of muscle developmental and implicated in neoplastic transformation. They are characterized by a split catalytic SET domain and an intervening MYND zinc finger domain, as well as an extended C-terminal domain. Saccharomyces cerevisiae contains two SMYD family members, Set5 and Set6, which share similar structural elements with the mammalian SMYD proteins. Set5 is a histone H4 lysine 5, 8, and 12 methyltransferase, implicated in the regulation of stress responses and genome stability. While the SMYD proteins have diverse roles in cells, there are many gaps in our understanding of how these enzymes are regulated. Here, we performed mutational analysis of Set5, combined with phosphoproteomics, to identify regulatory mechanisms for its enzymatic activity and subcellular localization. Our results indicate that the MYND domain promotes Set5 chromatin association in cells and mediates its interaction with DNA. Phosphoproteomics revealed extensive phosphorylation of Set5 and phosphomimetic mutations enhance Set5 catalytic activity and diminish its ability to interact with chromatin in cells. These studies uncover multiple regions within Set5 that regulate its localization and methyltransferase activity and highlight potential avenues for understanding mechanisms controlling the diverse roles of SMYD enzymes.
2019-11-11 | PXD014756 | Pride
Project description:Melanoma cells are highly plastic and have the ability to switch to a dedifferentiated, invasive phenotype in response to multiple stimuli. Here, we show that exposure of melanoma cell lines and patient specimens to multiple stresses including BRAF-MEK inhibitor therapy, hypoxia and UV-irradiation leads to an increase in histone deacetylase 8 (HDAC8) expression/activity, and in turn, the adoption of a drug-resistant, invasive phenotype. Systems level analyses using mass spectrometry-based phosphoproteomics implicated HDAC8 in the regulation of MAPK and AP-1 signaling pathways. Introduction of HDAC8 into drug-naïve melanoma cells conveyed resistance both in vitro and in in vivo xenograft models. HDAC8-mediated BRAF inhibitor resistance was mediated via receptor tyrosine kinase (RTK) activation leading to Ras/CRAF/MEK/ERK signaling. Although HDACs primarily function at the histone level, they also regulate signaling through the modulation of non-histone substrates. In line with this, HDAC8 introduction decreased the acetylation of c-Jun, increasing its transcriptional activity and enriching for an AP-1 gene signature. Mutation of the putative c-Jun acetylation site at lysine residue 273 reduced the transcriptional activation of c-Jun in melanoma cells and conveyed resistance to BRAF inhibition through increased RTK expression and enhanced MAPK pathway activity. In vivo xenograft studies confirmed the key role of HDAC8 in therapeutic adaptation, with both non-selective and HDAC8-specific inhibitors enhancing the durability of response to BRAF inhibitor therapy. Our studies demonstrate that HDAC8-specific inhibitors could represent an excellent strategy to limit the adaptation of melanoma cells to multiple stresses and therapeutic interventions, including BRAF-MEK inhibitor combinations.
2020-07-07 | PXD012813 | Pride
Project description:Melanoma cells are highly plastic and have the ability to switch to a dedifferentiated, invasive phenotype in response to multiple stimuli. Here, we show that exposure of melanoma cell lines and patient specimens to multiple stresses including BRAF-MEK inhibitor therapy, hypoxia and UV-irradiation leads to an increase in histone deacetylase 8 (HDAC8) expression/activity, and in turn, the adoption of a drug-resistant, invasive phenotype. Systems level analyses using mass spectrometry-based phosphoproteomics implicated HDAC8 in the regulation of MAPK and AP-1 signaling pathways. Introduction of HDAC8 into drug-naïve melanoma cells conveyed resistance both in vitro and in in vivo xenograft models. HDAC8-mediated BRAF inhibitor resistance was mediated via receptor tyrosine kinase (RTK) activation leading to Ras/CRAF/MEK/ERK signaling. Although HDACs primarily function at the histone level, they also regulate signaling through the modulation of non-histone substrates. In line with this, HDAC8 introduction decreased the acetylation of c-Jun, increasing its transcriptional activity and enriching for an AP-1 gene signature. Mutation of the putative c-Jun acetylation site at lysine residue 273 reduced the transcriptional activation of c-Jun in melanoma cells and conveyed resistance to BRAF inhibition through increased RTK expression and enhanced MAPK pathway activity. In vivo xenograft studies confirmed the key role of HDAC8 in therapeutic adaptation, with both non-selective and HDAC8-specific inhibitors enhancing the durability of response to BRAF inhibitor therapy. Our studies demonstrate that HDAC8-specific inhibitors could represent an excellent strategy to limit the adaptation of melanoma cells to multiple stresses and therapeutic interventions, including BRAF-MEK inhibitor combinations.
2020-07-07 | PXD012812 | Pride
Project description:Overexpression of histone deacetylases (HDACs) in cancer commonly causes resistance to genotoxic based therapies. Here we report on the novel mechanism whereby overexpressed class I HDACs increase the resistance of glioblastoma cells to the SN1 methylating agent temozolomide (TMZ). The chemotherapeutic TMZ triggers the activation of the DNA damage response (DDR) in resistant glioma cells, leading to DNA lesion bypass and cellular survival. Mass spectrometry analysis revealed that the catalytic activity of class I HDACs stimulates the expression of the E3 ubiquitin ligase RAD18. Furthermore, the data show that RAD18 is part of the O6-methylguanine-induced DDR as TMZ induces the formation of RAD18 foci at sites of DNA damage. Downregulation of RAD18 by HDAC inhibition prevents glioma cells from activating the DDR upon TMZ exposure. Lastly, RAD18 or O6-methylguanine-DNA methyltransferase (MGMT) overexpression abolishes the sensitization effect of HDAC inhibition on TMZ-exposed glioma cells. Our study describes the mechanism whereby class I HDAC overexpression in glioma cells causes resistance to TMZ treatment. HDACs accomplish this by promoting the bypass of O6-methylguanine DNA lesions via enhancing RAD18 expression. It also provides a treatment option with HDAC inhibition to undermine this mechanism.
2022-04-01 | PXD028683 | Pride
Project description:Abnormal activities of histone lysine demethylases (KDMs) and lysine deacetylases (HDACs) are associated with aberrant gene expression in breast cancer development. However, the precise molecular mechanisms underlying the crosstalk between KDMs and HDACs in chromatin remodeling and regulation of gene transcription are still elusive. In this study, we showed that treatment of human breast cancer cells with inhibitors targeting the zinc cofactor dependent class I/II HDACs, but not NAD+ dependent class III HDACs, led to significant increase of H3K4me2 which is a specific substrate of histone lysine-specific demethylase 1 (LSD1) and a key chromatin mark promoting transcriptional activation. We also demonstrated that inhibition of LSD1 activity by a pharmacological inhibitor, pargyline, or siRNA resulted in increased acetylation of H3K9 (AcH3K9). However, siRNA knockdown of LSD2, a homolog of LSD1, failed to alter the level of AcH3K9, suggesting that LSD2 activity may not be functionally connected with HDAC activity. Combined treatment with LSD1 and HDAC inhibitors resulted in enhanced levels of H3K4me2 and AcH3K9, and exhibited synergistic growth inhibition of breast cancer cells. Finally, microarray screening identified a unique subset of genes whose expression was significantly changed by combination treatment with inhibitors of LSD1 and HDAC. Our study suggests that LSD1 intimately interacts with histone deacetylases in human breast cancer cells. Inhibition of histone demethylation and deacetylation exhibits cooperation and synergy in regulating gene expression and growth inhibition, and may represent a promising and novel approach for epigenetic therapy of breast cancer. Twelve samples were subject to microarray anaylsis: 3 biological replicates were treated for 24h with 1)DMSO, 2) 5uM SAHA (suberanilohydroxamic acid), 3) 2.5mM Pargyline or 4) 5uM SAHA + 2.5mM Pargyline.
2015-09-04 | E-GEOD-72688 | biostudies-arrayexpress
Project description:As an essential component of histone methyltransferase complex SET1/MLL, WDR5 participates in histone 3 lysine 4 methylation (H3K4me) and promotes transcription by generating an open chromatin structure and enabling better access to the transcriptional machinery. Moreover, WDR5 interacts with histone deacetylases (HDACs) to promotes histone deacetylation, which induces the compact state of nucleosome, thus represses DNA transcription. However, the modulation of WDR5 on histone methylation and acetylation is tissue- and context-specific, and this function has not been elucidated in cholangiocarcinoma yet.
2021-02-23 | GSE162968 | GEO
Project description:Systems level analyses using mass spectrometry-based phosphoproteomics and RNA-Seq implicated HDAC8 in the regulation of MAPK and AP-1 signaling pathways. Introduction of HDAC8 into drug-naïve melanoma cells conveyed resistance both in vitro and in in vivo xenograft models. HDAC8-mediated BRAF inhibitor resistance was mediated via receptor tyrosine kinase (RTK) activation leading to Ras/CRAF/MEK/ERK signaling. Although HDACs primarily function at the histone level, they also regulate signaling through the modulation of non-histone substrates. In line with this, HDAC8 introduction decreased the acetylation of c-Jun, increasing its transcriptional activity and enriching for an AP-1 gene signature. Mutation of the putative c-Jun acetylation site at lysine residue 273 reduced the transcriptional activation of c-Jun in melanoma cells and conveyed resistance to BRAF inhibition through increased RTK expression and enhanced MAPK pathway activity.
2019-04-15 | GSE127564 | GEO
Project description:SMYD3, a member of the SET and MYND domain-containing (SMYD) family, is a histone methyltransferase (HMT) and transcription factor that plays an important role in transcriptional regulation in human carcinogenesis.In an effort to better understanding the mechanistic role of SMYD3, affinity purification and mass spectrometry assays were used to identify proteins associated with SMYD3 in vivo. In these experiments, FLAG-tagged SMYD3 or an empty vector was stably expressed in LM3 cells. Cellular extracts were prepared and subjected to affinity purification using an anti-FLAG affinity gel. Immunocomplexed proteins were separated using SDS–PAGE and silver stained. Immunoprecipitated proteins in specific bands in comparison to the vector were gel extracted, trypsin digested and identified using liquid chromatography tandem mass spectrometry.
2023-03-11 | PXD031971 | Pride
Project description:Abnormal activities of histone lysine demethylases (KDMs) and lysine deacetylases (HDACs) are associated with aberrant gene expression in breast cancer development. However, the precise molecular mechanisms underlying the crosstalk between KDMs and HDACs in chromatin remodeling and regulation of gene transcription are still elusive. In this study, we showed that treatment of human breast cancer cells with inhibitors targeting the zinc cofactor dependent class I/II HDACs, but not NAD+ dependent class III HDACs, led to significant increase of H3K4me2 which is a specific substrate of histone lysine-specific demethylase 1 (LSD1) and a key chromatin mark promoting transcriptional activation. We also demonstrated that inhibition of LSD1 activity by a pharmacological inhibitor, pargyline, or siRNA resulted in increased acetylation of H3K9 (AcH3K9). However, siRNA knockdown of LSD2, a homolog of LSD1, failed to alter the level of AcH3K9, suggesting that LSD2 activity may not be functionally connected with HDAC activity. Combined treatment with LSD1 and HDAC inhibitors resulted in enhanced levels of H3K4me2 and AcH3K9, and exhibited synergistic growth inhibition of breast cancer cells. Finally, microarray screening identified a unique subset of genes whose expression was significantly changed by combination treatment with inhibitors of LSD1 and HDAC. Our study suggests that LSD1 intimately interacts with histone deacetylases in human breast cancer cells. Inhibition of histone demethylation and deacetylation exhibits cooperation and synergy in regulating gene expression and growth inhibition, and may represent a promising and novel approach for epigenetic therapy of breast cancer.
2015-09-04 | GSE72688 | GEO