scholarly journals Chromatin accessibility combined with enhancer clusters activation mediates heterogeneous response to dexamethasone in myeloma cells

2021 ◽  
Author(s):  
Victor GABORIT ◽  
Jonathan CRUARD ◽  
Catherine Guerin-Charbonnel ◽  
Jennifer Derrien ◽  
Jean-Baptiste Alberge ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Target Genes ◽  
Interaction Network ◽  
Chromatin Accessibility ◽  
Enhancer Activity ◽  
Myeloma Cells ◽  
Combinatorial Assembly ◽  
Induced Apoptosis ◽  
Combination Regimens

Glucocorticoids (GC) effects occur through binding to the GC receptor (GR) which, once translocated to the nucleus, binds to GC response elements (GREs) to activate or repress target genes. Among GCs, dexamethasone (Dex) is widely used in treatment of multiple myeloma (MM), mainly in combination regimens. However, despite a definite benefit, all patients relapse. Moreover, while GC efficacy can be largely attributed to lymphocyte-specific apoptosis, its molecular basis remains elusive. To determine the functional role of GR binding in myeloma cells, we generated bulk and single cell multi-omic data and high-resolution contact maps of active enhancers and target genes. We show that a minority (6%) of GR binding sites are associated with enhancer activity gains and increased interaction loops. We find that enhancers contribute to regulate gene activity through combinatorial assembly of large stretches of enhancers and/or enhancer cliques. Furthermore, one enhancer, proximal to GR-responsive genes, is predominantly associated with increased chromatin accessibility and higher H3K27ac occupancy. Finally, we show that Dex exposure leads to co-accessibility changes between predominant enhancer and other regulatory regions of the interaction network. Notably, these epigenomic changes are associated with cell-to-cell transcriptional heterogeneity. As consequences, BIM critical for GR-induced apoptosis and CXCR4 protective from chemotherapy-induced apoptosis are rather upregulated in different cells. In summary, our work provides new insights into the molecular mechanisms involved in Dex escape.

scholarly journals The role of m6A modification in the biological functions and diseases

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Xiulin Jiang ◽  
Baiyang Liu ◽  
Zhi Nie ◽  
Lincan Duan ◽  
Qiuxia Xiong ◽  
...  
Keyword(s):  
Cancer Progression ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Rna Modification ◽  
Biological Functions ◽  
Rna Methylation ◽  
Downstream Target ◽  
Different Types ◽  
M6a Rna Methylation

AbstractN6-methyladenosine (m6A) is the most prevalent, abundant and conserved internal cotranscriptional modification in eukaryotic RNAs, especially within higher eukaryotic cells. m6A modification is modified by the m6A methyltransferases, or writers, such as METTL3/14/16, RBM15/15B, ZC3H3, VIRMA, CBLL1, WTAP, and KIAA1429, and, removed by the demethylases, or erasers, including FTO and ALKBH5. It is recognized by m6A-binding proteins YTHDF1/2/3, YTHDC1/2 IGF2BP1/2/3 and HNRNPA2B1, also known as “readers”. Recent studies have shown that m6A RNA modification plays essential role in both physiological and pathological conditions, especially in the initiation and progression of different types of human cancers. In this review, we discuss how m6A RNA methylation influences both the physiological and pathological progressions of hematopoietic, central nervous and reproductive systems. We will mainly focus on recent progress in identifying the biological functions and the underlying molecular mechanisms of m6A RNA methylation, its regulators and downstream target genes, during cancer progression in above systems. We propose that m6A RNA methylation process offer potential targets for cancer therapy in the future.

scholarly journals Discovery of MicroRNAs and Their Target Genes Related to Drought in Paulownia “Yuza 1” by High-Throughput Sequencing

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Minjie Deng ◽  
Yabing Cao ◽  
Zhenli Zhao ◽  
Lu Yang ◽  
Yanfang Zhang ◽  
...  
Keyword(s):  
Drought Stress ◽  
Molecular Mechanisms ◽  
High Throughput Sequencing ◽  
Plant Hormone ◽  
Target Genes ◽  
Reference Data ◽  
Relevant Information ◽  
Putative Target

Understanding the role of miRNAs in regulating the molecular mechanisms responsive to drought stress was studied in Paulownia “yuza 1.” Two small RNA libraries and two degradome libraries were, respectively, constructed and sequenced in order to detect miRNAs and their target genes associated with drought stress. A total of 107 miRNAs and 42 putative target genes were identified in this study. Among them, 77 miRNAs were differentially expressed between drought-treated Paulownia “yuza 1” and the control (60 downregulated and 17 upregulated). The predicted target genes were annotated using the GO, KEGG, and Nr databases. According to the functional classification of the target genes, Paulownia “yuza 1” may respond to drought stress via plant hormone signal transduction, photosynthesis, and osmotic adjustment. Furthermore, the expression levels of seven miRNAs (ptf-miR157b, ptf-miR159b, ptf-miR398a, ptf-miR9726a, ptf-M2153, ptf-M2218, and ptf-M24a) and their corresponding target genes were validated by quantitative real-time PCR. The results provide relevant information for understanding the molecular mechanism of Paulownia resistance to drought and reference data for researching drought resistance of other trees.

scholarly journals The p53/miR-34a/SIRT1 Positive Feedback Loop in Quercetin-Induced Apoptosis

2015 ◽  
Vol 35 (6) ◽  
pp. 2192-2202 ◽  
Author(s):  
Guohua Lou ◽  
Yanning Liu ◽  
Shanshan Wu ◽  
Jihua Xue ◽  
Fan Yang ◽  
...  
Keyword(s):  
Cell Apoptosis ◽  
Feedback Loop ◽  
Molecular Mechanisms ◽  
Rt Pcr ◽  
Cycle Arrest ◽  
Anticancer Effects ◽  
Huh7 Cells ◽  
Mirnas Expression ◽  
Induced Apoptosis

Background: The anti-tumor effects of quercetin have been reported, but the underlying molecular mechanisms remain to be elucidated. The aim of present study was to explore the role of miRNA in the anticancer effects of quercetin. Methods: The differential miRNAs expression between the HepG2 and Huh7 cells treated by quercetin were detected by microarray. The xCELLigence, Flow cytometry, RT-PCR and Western blot were used to analyze the cell proliferation, cell apoptosis, cell cycle arrest, anti-tumor genes, and protein expression. Results: miR-34a was up-regulated in HepG2 cells treated by quercetin exhibiting wild-type p53. When inhibiting the miR-34a, the sensitivity of the cells to quercetin decreased and the expression of the SIRT1 was up-regulated, but the acetylation of p53 and the expression of some genes related to p53 down-regulated. Conclusion: miR-34a plays an important role in the anti-tumor effects of querctin in HCC, miR-34a may be a tiemolecule between the p53 and SIRT1 and is composed of a p53/miR-34a/SIRT1 signal feedback loop, which could enhance apoptosis signal and significantly promote cell apoptosis.

scholarly journals ASC proneural transcription factors mediate the timely initiation of the neural program during neuroectodermal to neuroblast transition ensuring progeny fidelity

2021 ◽  
Author(s):  
Vasiliki Theodorou ◽  
Aikaterini Stefanaki ◽  
Minas Drakos ◽  
Dafne Triantafyllou ◽  
Christos Delidakis
Keyword(s):  
Transcription Factors ◽  
Target Genes ◽  
Regulatory Elements ◽  
Chromatin Accessibility ◽  
Cis Elements ◽  
Enhancer Activity ◽  
Timely Initiation ◽  
Chromatin Dynamics ◽  
Neural Fate ◽  
Neural Specification

Background: ASC/ASCL proneural transcription factors are oncogenic and exhibit impressive reprogramming and pioneer activities. In both Drosophila and mammals, these factors are central in the early specification of the neural fate, where they act in opposition to Notch signalling. However, the role of ASC on the chromatin during CNS neural stem cells birth remains elusive. Results: We investigated the chromatin changes accompanying neural commitment using an integrative genetics and genomics methodology. We found that ASC factors bind equally strongly to two distinct classes of cis-regulatory elements: open regions remodeled earlier during maternal to zygotic transition by Zelda and Zelda-independent, less accessible regions. Both classes cis-elements exhibit enhanced chromatin accessibility during neural specification and correlate with transcriptional regulation of genes involved in many biological processes necessary for neuroblast function. We identified an ASC-Notch regulated TF network that most likely act as the prime regulators of neuroblast function. Using a cohort of ASC target genes, we report that ASC null neuroblasts are defectively specified, remaining initially stalled, lacking expression of many proneural targets and unable to divide. When they eventually start proliferating, they produce compromised progeny. Generation of lacZ reporter lines driven by proneural-bound elements display enhancer activity within neuroblasts and proneural dependency. Therefore, the partial neuroblast identity seen in the absence of ASC genes is driven by other, proneural-independent, cis-elements. Neuroblast impairment and the late differentiation defects of ASC mutants are corrected by ectodermal induction of individual ASC genes but not by individual members of the TF network downstream of ASC. However, in wild type embryos induction of individual members of this network induces CNS hyperplasia, suggesting that they synergize with the activating function of ASC to establish the chromatin dynamics that promote neural specification. Conclusion: ASC factors bind a large number of enhancers to orchestrate the timely activation of the neural chromatin program during neuroectodermal to neuroblast transition. This early chromatin remodeling is crucial for both neuroblast homeostasis as well as future progeny fidelity.

scholarly journals Elucidating the Mechanisms of Hugan Buzure Granule in the Treatment of Liver Fibrosis via Network Pharmacology

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Yi Zhu ◽  
Ming Qiao ◽  
Jianhua Yang ◽  
Junping Hu
Keyword(s):  
Liver Fibrosis ◽  
Rna Polymerase Ii ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Docking Simulation ◽  
Interaction Network ◽  
Network Pharmacology ◽  
Transcription Activator ◽  
Active Ingredients ◽  
Oxidoreductase Activity

Objective. To holistically explore the latent active ingredients, targets, and related mechanisms of Hugan buzure granule (HBG) in the treatment of liver fibrosis (LF) via network pharmacology. Methods. First, we collected the ingredients of HBG by referring the TCMSP server and literature and filtered the active ingredients though the criteria of oral bioavailability ≥30% and drug-likeness index ≥0.18. Second, herb-associated targets were predicted and screened based on the BATMAN-TCM and SwissTargetPrediction platforms. Candidate targets related to LF were collected from the GeneCards and OMIM databases. Furthermore, the overlapping target genes were used to construct the protein-protein interaction network and “drug-compound-target-disease” network. Third, GO and KEGG pathway analyses were carried out to illustrate the latent mechanisms of HBG in the treatment of LF. Finally, the combining activities of hub targets with active ingredients were further verified based on software AutoDock Vina. Results. A total of 25 active ingredients and 115 overlapping target genes of HBG and LF were collected. Besides, GO enrichment analysis exhibited that the overlapping target genes were involved in DNA-binding transcription activator activity, RNA polymerase II-specific, and oxidoreductase activity. Simultaneously, the key molecular mechanisms of HBG against LF were mainly involved in PI3K-AKT, MAPK, HIF-1, and NF-κB signaling pathways. Also, molecular docking simulation demonstrated that the key targets of HBG for antiliver fibrosis were IL6, CASP3, EGFR, VEGF, and MAPK. Conclusion. This work validated and predicted the underlying mechanisms of multicomponent and multitarget about HBG in treating LF and provided a scientific foundation for further research.

scholarly journals Repurposing of KLF5 activates a cell cycle signature during the progression from a precursor state to Oesophageal Adenocarcinoma

2020 ◽  
Author(s):  
Connor Rogerson ◽  
Samuel Ogden ◽  
Edward Britton ◽  
Yeng Ang ◽  
Andrew D. Sharrocks ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Prognostic Significance ◽  
Gene Expression Signature ◽  
Chromatin Accessibility ◽  
Oesophageal Adenocarcinoma ◽  
Cell Cycle Gene ◽  
A Cell

AbstractOesophageal adenocarcinoma (OAC) is one of the most common causes of cancer deaths and yet compared to other common cancers, we know relatively little about the underlying molecular mechanisms. Barrett’s oesophagus (BO) is the only known precancerous precursor to OAC, but our understanding about the specific events leading to OAC development is limited. Here, we have integrated gene expression and chromatin accessibility profiles of human biopsies of BO and OAC and identified a strong cell cycle gene expression signature in OAC compared to BO. Through analysing associated chromatin accessibility changes, we have implicated the transcription factor KLF5 in the transition from BO to OAC. Importantly, we show that KLF5 expression is unchanged during this transition, but instead, KLF5 is redistributed across chromatin in OAC cells to directly regulate cell cycle genes specifically in OAC. Our findings have potential prognostic significance as the survival of patients with high expression of KLF5 target genes is significantly lower. We have provided new insights into the gene expression networks in OAC and the mechanisms behind progression to OAC, chiefly the repurposing of KLF5 for novel regulatory activity in OAC.

Abstract W MP86: Microrna-146a Modulates Neurogenesis And Oligodendrogenesis After Stroke

Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Xianshuang Liu ◽  
Chopp Michael ◽  
Xinli Wang ◽  
Li Zhang ◽  
Yisheng Cui ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Molecular Mechanisms ◽  
Neural Progenitor Cells ◽  
Target Genes ◽  
Artery Occlusion ◽  
Locked Nucleic Acid ◽  
Myelin Proteins ◽  
Oligodendrocyte Progenitor Cells ◽  
Marker Proteins

Background: Neurogenesis and oligodendrogenesis are associated with functional recovery after stroke. However, the molecules that regulate the generation of new neurons and oligodendrocytes have not been fully investigated. MicroRNAs (miRNAs) post-transcriptionally regulate gene expression. MiR-146a has been reported to regulate the immune response in cells, but the role of miR-146a in neural (NPCs) and oligodendrocyte progenitor cells (OPCs) remains unexplored. Methods and Results: Adult Wistar rats were subjected to right middle cerebral artery occlusion (MCAo). In situ hybridization using locked nucleic acid (LNA)probes against miR-146a showed that stroke considerably increased miR-146a density in the subventricular zone (SVZ, 19 ± 1 vs 6 ± 0.1 area/mm2 in non-MCAo group, p<0.05, n=4/group) and corpus callosum (24 ± 3 vs 8±1 area/mm2 in non-MCAo group) of the ischemic hemisphere. Quantitative RT-PCR also demonstrated a marked upregulation of miR-146a transcript in ischemic NPCs (8.5 fold), suggesting an important role in stroke-induced neurogenesis and oligodendrogenesis. To test its biological function, we over-expressed miR-146a in neural progenitor cells by transfection of miR-146a mimics using nucleofector and found that elevation of miR-146a significantly increased the percentage of Tuj1+ neuroblasts (5 ± 0.3 vs 1 ± 0.2%, p<0.05, n=6/group) and O4+ OPCs (10 ± 1 vs 4 ± 0.4%, p<0.05). Moreover, over-expression of miR-146a in primary cultured OPCs significantly increased several myelin proteins including MBP and PLP, and decreased levels of OPC marker proteins including PDGFRα and NG2, whereas attenuation of miR-146a by siRNA against miR-146a suppressed myelin proteins and augmented OPC marker proteins. Furthermore, miR-146a levels in the OPCs were inversely related to IRAK1 proteins, one of miR-146a target genes. Attenuation of IRAK1 in OPCs substantially increased myelin proteins, indicating that miR-146a mediates oligodendrocyte maturation via targeting IRAK1. Conclusion: Our data provide new insight into molecular mechanisms underlying stroke-induced neurogenesis and oligodendrogenesis by revealing a novel role of miR-146a in NPCs and OPCs, which has potential to be used as a new therapy for neurorecovery after stroke.

scholarly journals STAT3 and STAT5 Activation in Solid Cancers

Cancers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1428 ◽  
Author(s):  
Sebastian Igelmann ◽  
Heidi Neubauer ◽  
Gerardo Ferbeyre
Keyword(s):  
Tumor Suppressor ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Critical Role ◽  
Control Cell ◽  
Cytokine Signaling ◽  
Specific Gene ◽  
Mitochondrial Functions ◽  
Context Dependent

The Signal Transducer and Activator of Transcription (STAT)3 and 5 proteins are activated by many cytokine receptors to regulate specific gene expression and mitochondrial functions. Their role in cancer is largely context-dependent as they can both act as oncogenes and tumor suppressors. We review here the role of STAT3/5 activation in solid cancers and summarize their association with survival in cancer patients. The molecular mechanisms that underpin the oncogenic activity of STAT3/5 signaling include the regulation of genes that control cell cycle and cell death. However, recent advances also highlight the critical role of STAT3/5 target genes mediating inflammation and stemness. In addition, STAT3 mitochondrial functions are required for transformation. On the other hand, several tumor suppressor pathways act on or are activated by STAT3/5 signaling, including tyrosine phosphatases, the sumo ligase Protein Inhibitor of Activated STAT3 (PIAS3), the E3 ubiquitin ligase TATA Element Modulatory Factor/Androgen Receptor-Coactivator of 160 kDa (TMF/ARA160), the miRNAs miR-124 and miR-1181, the Protein of alternative reading frame 19 (p19ARF)/p53 pathway and the Suppressor of Cytokine Signaling 1 and 3 (SOCS1/3) proteins. Cancer mutations and epigenetic alterations may alter the balance between pro-oncogenic and tumor suppressor activities associated with STAT3/5 signaling, explaining their context-dependent association with tumor progression both in human cancers and animal models.

scholarly journals A Network Pharmacology-Based Study on the Anti-Lung Cancer Effect of Dipsaci Radix

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Jiayan Wu ◽  
Shengkun Hong ◽  
Xiankuan Xie ◽  
Wangmi Liu
Keyword(s):  
Lung Cancer ◽  
Chinese Medicine ◽  
Traditional Chinese Medicine ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Interaction Network ◽  
Network Pharmacology ◽  
Pathway Enrichment Analysis ◽  
Hub Genes ◽  
Active Compounds

Objective. Dipsaci Radix (DR) has been used to treat fracture and osteoporosis. Recent reports have shown that myeloid cells from bone marrow can promote the proliferation of lung cancer. However, the action and mechanism of DR has not been well defined in lung cancer. The aim of the present study was to define molecular mechanisms of DR as a potential therapeutic approach to treat lung cancer. Methods. Active compounds of DR with oral bioavailability ≥30% and drug-likeness index ≥0.18 were obtained from the traditional Chinese medicine systems pharmacology database and analysis platform. The potential target genes of the active compounds and bone were identified by PharmMapper and GeneCards, respectively. The compound-target network and protein-protein interaction network were built by Cytoscape software and Search Tool for the Retrieval of Interacting Genes webserver, respectively. GO analysis and pathway enrichment analysis were performed using R software. Results. Our study demonstrated that DR had 6 active compounds, including gentisin, sitosterol, Sylvestroside III, 3,5-Di-O-caffeoylquinic acid, cauloside A, and japonine. There were 254 target genes related to these active compounds as well as to bone. SRC, AKT1, and GRB2 were the top 3 hub genes. Metabolisms and signaling pathways associated with these hub genes were significantly enriched. Conclusions. This study indicated that DR could exhibit the anti-lung cancer effect by affecting multiple targets and multiple pathways. It reflects the traditional Chinese medicine characterized by multicomponents and multitargets. DR could be considered as a candidate for clinical anticancer therapy by regulating bone physiological functions.

scholarly journals SENP1-Mediated Desumoylation of DBC1 Inhibits Apoptosis Induced by High Glucose in Bovine Retinal Pericytes

2016 ◽  
Vol 2016 ◽  
pp. 1-11
Author(s):  
Jian Gao ◽  
Xia Chen ◽  
Qing Gu ◽  
Xiaoxiao Liu ◽  
Xun Xu
Keyword(s):  
Diabetic Retinopathy ◽  
High Glucose ◽  
Molecular Mechanisms ◽  
Characteristic Change ◽  
High Concentration ◽  
Retinal Pericytes ◽  
Specific Protease ◽  
Induced Apoptosis ◽  
Pericyte Loss

Pericyte loss is an early characteristic change in diabetic retinopathy, but its precise molecular mechanisms have not been elucidated. This study investigated the role of SENP1 in pericyte loss in diabetic retinopathy. We demonstrated that a high concentration of glucose inhibited the expression of the Sentrin/SUMO-specific protease 1 (SENP1), which resulted in an increase in DBC1 sumoylation in bovine retinal pericytes (BRPCs). Furthermore, SENP1 overexpression attenuated hyperemia-induced apoptosis of BPRCs, and SENP1 knockdown aggravated this effect. We also provide evidence that DBC1 sumoylation/desumoylation is involved in the SENP1-regulated apoptosis of BRPCs under high glucose conditions. Understanding the role of SENP1 in the pathogenesis of high glucose induced pericyte loss could help elucidate important targets for future pharmacological interventions.

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