keyword
MENU ▼
Read by QxMD icon Read
search

polycomb repressor complex

keyword
https://www.readbyqxmd.com/read/28612725/-the-biological-complexity-of-polycomb-group-proteins-the-case-of-ezh2
#1
Myriam Koubi, Christian Chabannon, Estelle Duprez
Polycomb Group proteins (PcG) are repressive epigenetic factors essential for development and involved in numerous cancer processes, yet their modes of action and recruitment to specific genomic loci are not fully understood. Recently, it has been shown that the PcG protein recruitment is a dynamic process, contrary to what was foreseen in the initial hierarchical model. In addition, EZH2, a key PcG protein, can be associated to transcribed genes, challenging the former function of PcG proteins as transcriptional repressors...
May 2017: Médecine Sciences: M/S
https://www.readbyqxmd.com/read/28591729/bmi-1-is-a-potential-therapeutic-target-in-diffuse-intrinsic-pontine-glioma
#2
Shiva Senthil Kumar, Satarupa Sengupta, Kyungwoo Lee, Nanki Hura, Christine Fuller, Mariko DeWire, Charles B Stevenson, Maryam Fouladi, Rachid Drissi
Diffuse intrinsic pontine glioma (DIPG) is a poor-prognosis pediatric brain tumor. No effective curative therapy is currently available and no therapeutic advances have been made in several decades. BMI-1 is a member of the multimeric protein complex Polycomb repressor complex 1. It is highly expressed in a number of diseases and malignancies and has been implicated in self-renewal of normal and cancer cells, and in DNA damage signaling. The role of BMI-1 in DIPG is largely unknown. Here, we show that BMI-1 is highly expressed in tumor tissue samples of DIPG patients and in patient-derived cancer stem-like cells...
May 19, 2017: Oncotarget
https://www.readbyqxmd.com/read/28584023/notch-represses-transcription-by-prc2-recruitment-to-the-ternary-complex
#3
Xiaoqing Han, Prathibha Ranganathan, Christos Tzimas, Kelly L Weaver, Ke Jin, Luisana Astudillo, Wen Zhou, Xiaoxia Zhu, Bin Li, David J Robbins, Anthony J Capobianco
It is well established that Notch functions as a transcriptional activator through the formation of a ternary complex that comprises Notch, Maml and CSL. This ternary complex then serves to recruit additional transcriptional cofactors that link to higher order transcriptional complexes. The mechanistic details of these events remain unclear. This report reveals that the Notch ternary complex can direct the formation of a repressor complex to terminate gene expression of select target genes. Herein, it is demonstrated that p19Arf and Klf4 are transcriptionally repressed in a Notch-dependent manner...
June 5, 2017: Molecular Cancer Research: MCR
https://www.readbyqxmd.com/read/28512107/divergent-requirements-for-ezh1-in-heart-development-versus-regeneration
#4
Shanshan Ai, Xianhong Yu, Yumei Li, Yong Peng, Chen Li, Yanzhu Yue, Ge Tao, Chuan-Yun Li, William T Pu, Aibin He
Rationale: Polycomb repressive complex 2 (PRC2) is a major epigenetic repressor that deposits methylation on histone H3 on lysine 27 (H3K27me) and controls differentiation and function of many cells, including cardiac myocytes. EZH1 and EZH2 are two alternative catalytic subunits with partial functional redundancy. The relative roles of EZH1 and EZH2 in heart development and regeneration are unknown. Objective: We compared the roles of EZH1 versus EZH2 in heart development and neonatal heart regeneration. Methods and Results: Heart development was normal in Ezh1(-/-) (E1KO) and Ezh2(f/f)::cTNT(-Cre) (E2KO) embryos...
May 16, 2017: Circulation Research
https://www.readbyqxmd.com/read/28455403/concerted-divergence-after-gene-duplication-in-polycomb-repressive-complexes
#5
Yichun Qiu, Shao-Lun Liu, Keith L Adams
Duplicated genes are a major contributor to genome evolution and phenotypic novelty. There are multiple possible evolutionary fates of duplicated genes. Here, we provide an example of concerted divergence of simultaneously duplicated genes whose products function in the same complex. We studied POLYCOMB REPRESSIVE COMPLEX2 (PRC2) in Brassicaceae. The VERNALIZATION (VRN)-PRC2 complex contains VRN2 and SWINGER (SWN), and both genes were duplicated during a whole-genome duplication to generate FERTILIZATION INDEPENDENT SEED2 (FIS2) and MEDEA (MEA), which function in the Brassicaceae-specific FIS-PRC2 complex that regulates seed development...
June 2017: Plant Physiology
https://www.readbyqxmd.com/read/28423699/long-non-coding-rna-lucat1-is-associated-with-poor-prognosis-in-human-non-small-lung-cancer-and-regulates-cell-proliferation-via-epigenetically-repressing-p21-and-p57-expression
#6
Yue Sun, Shi-Dai Jin, Quan Zhu, Liang Han, Jing Feng, Xi-Yi Lu, Wei Wang, Feng Wang, Ren-Hua Guo
Recently, long non-coding RNAs (lncRNAs) have been recognized as playing key roles in regulating cellular processes, such as proliferation, invasion, and metastasis. These lncRNAs have been shown to be abnormally expressed in tumorigenic processes. However, the role and clinical relevance of LUCAT1 in non-small-cell lung cancer (NSCLC) remain unclear. In this study, we found that the expression of LUCAT1 was significantly up-regulated in NSCLC tissues compared to non-tumor tissues, and its expression was associated with tumor size, tumor-node-metastasis (TNM) stage and overall survival (OS)...
April 25, 2017: Oncotarget
https://www.readbyqxmd.com/read/28416772/dna-methylation-of-mettl7a-gene-body-regulates-its-transcriptional-level-in-thyroid-cancer
#7
Shasha Zhou, Yihang Shen, Min Zheng, Linlin Wang, Raymond Che, Wanning Hu, Pin Li
DNA methylation is the best-studied epigenetic mechanism for regulating gene transcription and maintaining genome stability. Current research progress of transcriptional regulation by DNA methylation mostly focuses on promoter region where hypomethylated CpG islands are present transcriptional activity, as hypermethylated CpG islands generally result in gene repression. Recently, the DNA methylation patterns across the gene body (intragenic methylation) have increasingly attracted attention towards their role in transcriptional regulation and efficiency, due to the improvement of numerous genome-wide DNA methylation profiling studies...
May 23, 2017: Oncotarget
https://www.readbyqxmd.com/read/28415635/role-of-ezh2-in-cancer-stem-cells-from-biological-insight-to-a-therapeutic-target
#8
REVIEW
Yiping Wen, Jing Cai, Yaya Hou, Zaiju Huang, Zehua Wang
Epigenetic modifications in cancer stem cells largely result in phenotypic and functional heterogeneity in many solid tumors. Increasing evidence indicates that enhancer of zeste homolog 2 (EZH2), the catalytic subunit of Polycomb repressor complex 2, is highly expressed in cancer stem cells of numerous malignant tumors and has a critical function in cancer stem cell expansion and maintenance. Here, we review up-to-date information regarding EZH2 expression patterns, functions, and molecular mechanisms in cancer stem cells in various malignant tumors and discuss the therapeutic potential of targeting EZH2 in tumors...
June 6, 2017: Oncotarget
https://www.readbyqxmd.com/read/28410242/functional-and-therapeutic-significance-of-ezh2-in-urological-cancers
#9
REVIEW
Xiaobing Liu, Qingjian Wu, Longkun Li
The enhancer of zeste homolog 2 (EZH2) is a core subunit of the polycomb repressor complex 2 (PRC2), which is overexpressed in numerous cancers and mutated in several others. Notably, EZH2 acts not only a critical epigenetic repressor through its role in histone methylation, it is also an activator of gene expression, acting through multiple signaling pathways in distinct cancer types. Increasing evidence suggests that EZH2 is an oncogene and is central to initiation, growth and progression of urological cancers...
June 6, 2017: Oncotarget
https://www.readbyqxmd.com/read/28359242/small-molecule-inhibitors-of-epigenetic-mutations-as-compelling-drug-targets-for-myelodysplastic-syndromes
#10
Bani Bandana Ganguly
BACKGROUND: Involvement of mutations in epigenetic mechanism in development of heterogeneous MDS and its evolution to AML has been understood with at least one mutation and median of 2-3 mutations of the landscapes of driver mutations in ~40 genes described >90% MDS patients. Exclusivity and cooperating effects of mutations have directed therapeutic implementation with hypomethylating agents and identified a number of first-in-class small molecules as inhibitors of mutational expression...
March 30, 2017: Current Cancer Drug Targets
https://www.readbyqxmd.com/read/28340355/the-human-immunodeficiency-virus-1-asp-rna-promotes-viral-latency-by-recruiting-the-polycomb-repressor-complex-2-and-promoting-nucleosome-assembly
#11
Juan C Zapata, Federica Campilongo, Robert A Barclay, Catherine DeMarino, Maria D Iglesias-Ussel, Fatah Kashanchi, Fabio Romerio
Various epigenetic marks at the HIV-1 5'LTR suppress proviral expression and promote latency. Cellular antisense transcripts known as long noncoding RNAs (lncRNAs) recruit the polycomb repressor complex 2 (PRC2) to gene promoters, which catalyzes trimethylation of lysine 27 on histone H3 (H3K27me3), thus promoting nucleosome assembly and suppressing gene expression. We found that an HIV-1 antisense transcript expressed from the 3'LTR and encoding the antisense protein ASP promotes proviral latency. Expression of ASP RNA reduced HIV-1 replication in Jurkat cells...
June 2017: Virology
https://www.readbyqxmd.com/read/28323035/naturally-occurring-anti-cancer-agents-targeting-ezh2
#12
Fahimeh Shahabipour, Michele Caraglia, Muhammed Majeed, Giuseppe Derosa, Pamela Maffioli, Amirhossein Sahebkar
Natural products are considered as promising tools for the prevention and treatment of cancer. The enhancer of zeste homolog 2 (EZH2) is a histone methyltransferase unit of polycomb repressor complexes such as PRC2 complex that has oncogenic roles through interference with growth and metastatic potential. Several agents targeting EZH2 has been discovered but they often induce side effects in clinical trials. Recently, EZH2 has emerged as a potential target of natural products with documented anti-cancer effects and this discloses a new scenario for the development of EZH2 inhibitory strategies with agents with low cytotoxic detrimental effects...
March 18, 2017: Cancer Letters
https://www.readbyqxmd.com/read/28320739/a-covalently-bound-inhibitor-triggers-ezh2-degradation-through-chip-mediated-ubiquitination
#13
Xu Wang, Wei Cao, Jianjun Zhang, Ming Yan, Qin Xu, Xiangbing Wu, Lixin Wan, Zhiyuan Zhang, Chenping Zhang, Xing Qin, Meng Xiao, Dongxia Ye, Yuyang Liu, Zeguang Han, Shaomeng Wang, Li Mao, Wenyi Wei, Wantao Chen
Enhancer of zeste homolog 2 (EZH2) has been characterized as a critical oncogene and a promising drug target in human malignant tumors. The current EZH2 inhibitors strongly suppress the enhanced enzymatic function of mutant EZH2 in some lymphomas. However, the recent identification of a PRC2- and methyltransferase-independent role of EZH2 indicates that a complete suppression of all oncogenic functions of EZH2 is needed. Here, we report a unique EZH2-targeting strategy by identifying a gambogenic acid (GNA) derivative as a novel agent that specifically and covalently bound to Cys668 within the EZH2-SET domain, triggering EZH2 degradation through COOH terminus of Hsp70-interacting protein (CHIP)-mediated ubiquitination...
May 2, 2017: EMBO Journal
https://www.readbyqxmd.com/read/28132848/vernalization-triggered-intragenic-chromatin-loop-formation-by-long-noncoding-rnas
#14
Dong-Hwan Kim, Sibum Sung
Long noncoding RNAs (lncRNAs) affect gene regulation through structural and regulatory interactions with associated proteins. The Polycomb complex often binds to lncRNAs in eukaryotes, and an lncRNA, COLDAIR, associates with Polycomb to mediate silencing of the floral repressor FLOWERING LOCUS C (FLC) during the process of vernalization in Arabidopsis. Here, we identified an additional Polycomb-binding lncRNA, COLDWRAP. COLDWRAP is derived from the repressed promoter of FLC and is necessary for the establishment of the stable repressed state of FLC by vernalization...
February 6, 2017: Developmental Cell
https://www.readbyqxmd.com/read/28068325/trim28-interacts-with-ezh2-and-swi-snf-to-activate-genes-that-promote-mammosphere-formation
#15
J Li, Y Xi, W Li, R L McCarthy, S A Stratton, W Zou, W Li, S Y Dent, A K Jain, M C Barton
Histone methyl transferase EZH2 (Enhancer of Zeste Homolog 2) is generally associated with H3K27 methylation and gene silencing, as a member of the polycomb repressor 2 (PRC2) complex. Immunoprecipitation and mass spectrometry of the EZH2-protein interactome in estrogen receptor positive, breast cancer-derived MCF7 cells revealed EZH2 interactions with subunits of chromatin remodeler SWI/SNF complex and TRIM28, which formed a complex with EZH2 distinct from PRC2. Unexpectedly, transcriptome profiling showed that EZH2 primarily activates, rather than represses, transcription in MCF7 cells and with TRIM28 co-regulates a set of genes associated with stem cell maintenance and poor survival of breast cancer patients...
May 25, 2017: Oncogene
https://www.readbyqxmd.com/read/27932267/human-pre-pik3c2b-an-intronic-cis-element-with-dual-function-of-activation-and-repression
#16
Jayant Maini, Mohsen Ghasemi, Deepti Yandhuri, Suman S Thakur, Vani Brahmachari
The Polycomb/Trithorax Responsive Elements (PRE/TREs) are the cis-regulatory sequences that interact with both repressive (PcG) as well as activating (TrxG) complexes. However, most of the mammalian PREs are demonstrated to interact with the repressive polycomb (PcG) complexes only. We have carried out an unbiased search for proteins interacting with human PRE-PIK3C2B (hPRE-PIK3C2B) based on DNA affinity purification followed by mass spectrometry and identified MLL, MLL4 and WDR87 among other proteins in three biological replicates in HEK, U87 and HeLa cell lines...
December 6, 2016: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/27898079/a-dna-element-that-remembers-winter
#17
Chenlong Li, Yuhai Cui
Polycomb-mediated silencing of the floral repressor gene FLC in response to long-term cold is a central event during vernalization in Arabidopsis thaliana, but how it is initiated is unclear. Two new studies identify a DNA element that mediates FLC silencing by attracting a pair of transcriptional repressors, VAL1 and VAL2, which in turn trigger epigenetic silencing by the Polycomb complex PHD-PRC2.
November 29, 2016: Nature Genetics
https://www.readbyqxmd.com/read/27856324/mll-af4-binds-directly-to-a-bcl-2-specific-enhancer-and-modulates-h3k27%C3%A2-acetylation
#18
Laura Godfrey, Jon Kerry, Ross Thorne, Emmanouela Repapi, James O J Davies, Marta Tapia, Erica Ballabio, Jim R Hughes, Huimin Geng, Marina Konopleva, Thomas A Milne
Survival rates for children and adults carrying mutations in the Mixed Lineage Leukemia (MLL) gene continue to have a very poor prognosis. The most common MLL mutation in acute lymphoblastic leukemia is the t(4;11)(q21;q23) chromosome translocation that fuses MLL in-frame with the AF4 gene producing MLL-AF4 and AF4-MLL fusion proteins. Previously, we found that MLL-AF4 binds to the BCL-2 gene and directly activates it through DOT1L recruitment and increased H3K79me2/3 levels. In the study described here, we performed a detailed analysis of MLL-AF4 regulation of the entire BCL-2 family...
March 2017: Experimental Hematology
https://www.readbyqxmd.com/read/27716060/mir-27b-shapes-the-presynaptic-transcriptome-and-influences-neurotransmission-by-silencing-the-polycomb-group-protein-bmi1
#19
Vivian Y Poon, Minxia Gu, Fang Ji, Antonius M VanDongen, Marc Fivaz
BACKGROUND: MicroRNAs (miRNAs) are short non-coding RNAs that are emerging as important post-transcriptional regulators of neuronal and synaptic development. The precise impact of miRNAs on presynaptic function and neurotransmission remains, however, poorly understood. RESULTS: Here, we identify miR-27b-an abundant neuronal miRNA implicated in neurological disorders-as a global regulator of the presynaptic transcriptome. miR-27b influences the expression of three quarters of genes associated with presynaptic function in cortical neurons...
October 4, 2016: BMC Genomics
https://www.readbyqxmd.com/read/27705745/rybp-stimulates-prc1-to-shape-chromatin-based-communication-between-polycomb-repressive-complexes
#20
Nathan R Rose, Hamish W King, Neil P Blackledge, Nadezda A Fursova, Katherine Ji Ember, Roman Fischer, Benedikt M Kessler, Robert J Klose
Polycomb group (PcG) proteins function as chromatin-based transcriptional repressors that are essential for normal gene regulation during development. However, how these systems function to achieve transcriptional regulation remains very poorly understood. Here, we discover that the histone H2AK119 E3 ubiquitin ligase activity of Polycomb repressive complex 1 (PRC1) is defined by the composition of its catalytic subunits and is highly regulated by RYBP/YAF2-dependent stimulation. In mouse embryonic stem cells, RYBP plays a central role in shaping H2AK119 mono-ubiquitylation at PcG targets and underpins an activity-based communication between PRC1 and Polycomb repressive complex 2 (PRC2) which is required for normal histone H3 lysine 27 trimethylation (H3K27me3)...
October 5, 2016: ELife
keyword
keyword
68352
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"