scholarly journals Defining the Transcriptional Control of Pediatric AML Highlights RARA as a Super-Enhancer Regulated Druggable Dependency

2021 ◽  
Author(s):  
Monika W. Perez ◽  
Oscar Sias-Garcia ◽  
Alfred Daramola ◽  
Helen Wei ◽  
Maci C Terrell ◽  
...  
Keyword(s):  
Transcriptional Control ◽  
Somatic Mutations ◽  
Molecular Subtypes ◽  
Retinoic Acid Receptor ◽  
Mrna Levels ◽  
Apoptosis Induction ◽  
Super Enhancer ◽  
Alpha 7 ◽  
Pediatric Aml

Somatic mutations are rare in pediatric AML (pAML), indicating alternate strategies are needed to identify targetable dependencies. We performed the first enhancer mapping of 3 pAML in 22 patient samples. Generally, pAML samples were distinct from adult AML 4 samples, and MLL (KMT2A)-rearranged samples were also distinct from non-KMT2A-5 rearranged samples. Focusing specifically on super-enhancers (SEs), we identified SEs 6 associated with many known leukemia regulators. The retinoic acid receptor alpha 7 (RARA) gene was differentially regulated in our cohort, and a RARA associated SE was 8 detected in 64% our cohort across all cyto/molecular subtypes tested. RARA SE-positive 9 pAML cell lines and samples demonstrated high RARA mRNA levels. These samples 10 were specifically sensitive to the synthetic RARA agonist tamibarotene in vitro, with 11 slowed proliferation, apoptosis induction, differentiation, and upregulated retinoid target 12 gene expression, compared to RARA SE-negative samples. Tamibarotene prolonged 13 survival and suppressed the leukemia burden of a RARA SE-positive pAML patient-14 derived xenograft (PDX) mouse model compared to a RARA SE-negative PDX. Our work 15 demonstrates that examining chromatin regulation can identify new, druggable 16 dependencies in pAML and provides rationale for a pediatric tamibarotene trial in children 17 with RARA-high AML.

CREB trans-activates the murine H+-K+-ATPase α2-subunit gene

2004 ◽  
Vol 287 (4) ◽  
pp. C903-C911 ◽  
Author(s):  
Xiangyang Xu ◽  
Wenzheng Zhang ◽  
Bruce C. Kone
Keyword(s):  
Dna Binding ◽  
Transcriptional Control ◽  
Luciferase Activity ◽  
Collecting Duct ◽  
Binding Activity ◽  
Dominant Negative ◽  
Proximal Promoter ◽  
Mrna Levels ◽  
Dna Binding Activity

Despite its key role in potassium homeostasis, transcriptional control of the H+-K+-ATPase α2-subunit (HKα2) gene in the collecting duct remains poorly characterized. cAMP increases H+-K+-ATPase activity in the collecting duct, but its role in activating HKα2 transcription has not been explored. Previously, we demonstrated that the proximal 177 bp of the HKα2 promoter confers basal collecting duct-selective expression. This region contains several potential cAMP/Ca2+-responsive elements (CRE). Accordingly, we examined the participation of CRE-binding protein (CREB) in HKα2 transcriptional control in murine inner medullary collecting duct (mIMCD)-3 cells. Forskolin and vasopressin induced HKα2 mRNA levels, and CREB overexpression stimulated the activity of HKα2 promoter-luciferase constructs. Serial deletion analysis revealed that CREB inducibility was retained in a construct containing the proximal 100 bp of the HKα2 promoter. In contrast, expression of a dominant negative inhibitor (A-CREB) resulted in 60% lower HKα2 promoter-luciferase activity, suggesting that constitutive CREB participates in basal HKα2 transcriptional activity. A constitutively active CREB mutant (CREB-VP16) strongly induced HKα2 promoter-luciferase activity, whereas overexpression of CREBdLZ-VP16, which lacks the CREB DNA-binding domain, abolished this activation. In vitro DNase I footprinting and gel shift/supershift analysis of the proximal promoter with recombinant glutathione S-transferase (GST)-CREB-1 and mIMCD-3 cell nuclear extracts revealed sequence-specific DNA-CREB-1 complexes at −86/−60. Mutation at three CRE-like sequences within this region abolished CREB-1 DNA-binding activity and abrogated CREB-VP16 trans-activation of the HKα2 promoter. In contrast, mutation of the neighboring −104/−94 κβ element did not alter CREB-VP16 trans-activation of the HKα2 promoter. Thus CREB-1, binding to one or more CRE-like elements in the −86/−60 region, trans-activates the HKα2 gene and may represent an important link between rapid and delayed effects of cAMP on HKα2 activity.

scholarly journals Novel insights into the regulation of chemerin expression: role of acute-phase cytokines and DNA methylation

2019 ◽  
Author(s):  
Kamila Kwiecien ◽  
Piotr Brzoza ◽  
Pawel Majewski ◽  
Izabella Skulimowska ◽  
Kamil Bednarczyk ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Acute Phase ◽  
Molecular Mechanisms ◽  
Retinoic Acid Receptor ◽  
Constitutive Expression ◽  
Sequencing Analysis ◽  
Mrna Levels ◽  
Pleiotropic Actions

AbstractChemerin is a chemoattractant protein with adipokine properties encoded by the retinoic acid receptor responder 2 (RARRES2) gene. It has gained more attention over the past few years due to its multilevel impact on metabolism and immune responses. The pleiotropic actions of chemerin include chemotaxis of dendritic cells, macrophages and natural killers (NK) subsets, bactericidal activity as well as regulation of adipogenesis and glucose metabolism. Therefore, reflecting the pleiotropic actions of chemerin, expression of RARRES2 is regulated by a variety of inflammatory and metabolic mediators. However, for most cell types, the molecular mechanisms controlling constitutive and regulated chemerin expression are poorly characterized. Here we show that RARRES2 mRNA levels in murine adipocytes are upregulated in vitro and in vivo by acute-phase cytokines, IL-1β and OSM. In contrast to adipocytes, these cytokines exerted a weak, if any, response in mouse hepatocytes, suggesting that the effect of IL-1β and OSM on chemerin expression is specific to fat tissue. Moreover, we show that DNA methylation controls the constitutive expression of chemerin. Bisulfite sequencing analysis showed low methylation levels within −735 to +258 bp of the murine RARRES2 gene promoter in unstimulated adipocytes and hepatocytes. In contrast to these cells, the RARRES2 promoter is highly methylated in B lymphocytes, cells that do not produce chemerin. Together, our findings reveal previously uncharacterized mediators and mechanisms controlling chemerin expression in various cells.

scholarly journals Both Estrogen Receptor α and β Stimulate Pituitary GH Gene Expression

2014 ◽  
Vol 28 (1) ◽  
pp. 40-52 ◽  
Author(s):  
Dimiter Avtanski ◽  
Horacio J. Novaira ◽  
Sheng Wu ◽  
Christopher J. Romero ◽  
Rhonda Kineman ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Mrna Expression ◽  
Transcriptional Control ◽  
Estrogen Receptor Α ◽  
In Vitro Models ◽  
Mrna Levels ◽  
Ovariectomized Mice ◽  
Serum Gh

Abstract Although sex steroids have been implicated in the control of mammalian growth, their direct effect on GH synthesis is less clear. The aim of this study was to establish whether estradiol (E2) directly affects GH synthesis in somatotrophs. Somatotroph GH3 and MtT/S cells were used as in vitro models. At physiological doses of E2 stimulation, GH mRNA levels were increased and the ER antagonist ICI 182,780 completely abolished this effect. Estrogen receptor (ER) α– and ERβ-selective agonists, propylpyrazole triol (PPT), and 2,3-bis(4-hydroxyphenyl) propionitrile (DPN), respectively, augmented GH mRNA expression and secretion, whereas E2 and PPT, but not DPN increased prolactin (PRL) mRNA levels. E2, PPT, and DPN stimulated expression of the pituitary transcription factor Pou1f1 and increased its binding to the GH promoter. In vivo evidence of E2 effects on GH synthesis was obtained from the generation of the somatotroph-specific ERα knockout (sERα-KO) mouse model. Basal pituitary GH, PRL, POU1F1, and ERα mRNA expression levels were lower in sERα-KO mice compared with those in controls; whereas ERβ mRNA levels remained unchanged. E2 and DPN stimulated pituitary GH mRNA expression and serum GH levels in control and sERα-KO ovariectomized mice; however, serum GH levels were unchanged in PPT-treated ovariectomized sERα-KO mice. In these animal models, PRL mRNA levels increased after either E2 or PPT, but an increase was not seen after DPN treatment. Thus, we propose a mechanism by which estrogen directly regulates somatotroph GH synthesis at a pretranslational level. In contrast to the predominant effect of ERα in the lactotroph, these results support a role for both ERα and ERβ in the transcriptional control of Gh in the somatotroph and illustrate important differences in ER isoform specificity in the anterior pituitary gland.

scholarly journals Effects of Rexinoids on Thyrotrope Function and the Hypothalamic-Pituitary-Thyroid Axis

Endocrinology ◽  
2006 ◽  
Vol 147 (3) ◽  
pp. 1438-1451 ◽  
Author(s):  
Vibha Sharma ◽  
William R. Hays ◽  
William M. Wood ◽  
Umarani Pugazhenthi ◽  
Donald L. St. Germain ◽  
...  
Keyword(s):  
Direct Effect ◽  
Promoter Activity ◽  
Retinoic Acid Receptor ◽  
Mrna Levels ◽  
Central Hypothyroidism ◽  
Iodothyronine Deiodinase ◽  
Pituitary Thyroid Axis ◽  
Thyroid Axis

Retinoid X receptor (RXR)-selective retinoids (rexinoids) can cause central hypothyroidism in humans, and this effect has been confirmed in rodent models. In this report, we characterized the effect of rexinoids on the hypothalamic-pituitary-thyroid axis in mice and TSH regulation in a thyrotrope-derived cell line. The synthetic rexinoid (LG 268) suppressed TSH and T4 levels in mice. Hypothalamic TRH mRNA was unaffected, but steady-state pituitary TSHβ mRNA levels were significantly lowered, suggesting a direct effect of rexinoids on thyrotropes. LG 268 suppressed TSH protein secretion and TSHβ mRNA in TαT1 thyrotropes as early as 8 h after treatment, whereas the retinoic acid receptor-selective retinoid (TTNPB) had no effect. Type 2 iodothyronine deiodinase (D2) mRNA and activity were suppressed by LG 268 in TαT1 cells, whereas only D2 mRNA was suppressed in mouse pituitaries. LG 268 suppressed TSHβ promoter activity by 42% and the −200 to −149 region accounted for a majority of the LG 268-mediated suppression of promoter activity. The RXRγ isotype is expressed in thyrotropes. In vitro transfection and in vivo transgenic studies indicate that any RXR isotype can mediate TSH suppression by rexinoids, but the RXRγ isotype is most efficient at mediating this response. RXRγ-deficient mice lacked pituitary D2 mRNA suppression by LG 268, but D2 activity remained intact. In summary, RXR-selective retinoids (rexinoids) have multiple effects on the hypothalamic-pituitary-thyroid axis. Rexinoids directly suppress TSH secretion, TSHβ mRNA levels and promoter activity, and D2 mRNA levels but have no direct effect on hypothalamic TRH levels. Rexinoids also stimulate type 1 iodothyronine deiodinase activity in the liver and pituitary.

scholarly journals Aberrant super-enhancer landscape reveals core transcriptional regulatory circuitry in lung adenocarcinoma

Oncogenesis ◽  
2020 ◽  
Vol 9 (10) ◽  
Author(s):  
Te Zhang ◽  
Xuming Song ◽  
Zeyu Zhang ◽  
Qixing Mao ◽  
Wenjie Xia ◽  
...  
Keyword(s):  
Lung Adenocarcinoma ◽  
Mrna Levels ◽  
Loss Of Function ◽  
Lung Carcinogenesis ◽  
Super Enhancer ◽  
Regulatory Circuits ◽  
Transcriptional Regulatory ◽  
Chromatin Immunoprecipitation Sequencing ◽  
High Proliferative Activity

Abstract Lung adenocarcinoma (LUAD) relies on dysregulated gene expression to sustain its infinite growth and progression. Emerging evidence indicates that aberrant transcriptional program results from core transcriptional regulatory circuitry (CRC) which is driven by super-enhancers (SEs). In this study, by integrating profiles of H3K27Ac chromatin immunoprecipitation sequencing (ChIP-seq) from normal adult lung and LUAD cell lines, we revealed that widespread alterations of the super-enhancer were presence during lung carcinogenesis. With SE-based modeling of regulatory circuits and assessments of transcription factor (TF) dependencies, we reconstructed an interconnected transcriptional regulation network formed by three master TFs, including ELF3, EHF, and TGIF1, all of which promoted each other’s expression that confirmed by ChIP-qPCR and western blot. Loss-of function assay revealed that each of them is essential for LUAD cells survival, invasion and metastasis. Meanwhile, the rescue assay also illustrated the transacting transcriptional regulatory circuitry. In addition, the mRNA levels of ELF3, EHF, and TGIF1 were differentially expressed in LUAD tumors and peritumoral tissue. IHC of serial sections revealed that high expressions of CRC (ELF3/EHF/TGIF1-High) were closely associated with high proliferative activity in tumor tissue and poor prognosis on patients with LUAD. Finally, we used small molecular inhibitors to perturb the transcriptional circuitry, also exhibited a prominent anti-cancer effect in vitro. Our findings reveal the mechanism of the transcriptional dysregulation and addiction of LUAD.

GLIOBLASTOMA MULTIFORME: PATHOGENESIS AND MOLECULAR MARKERS

2017 ◽  
Vol 63 (5) ◽  
pp. 695-702
Author(s):  
Oleg Kit ◽  
Dmitriy Vodolazhskiy ◽  
Yelena Frantsiyants ◽  
Svetlana Panina ◽  
E. Rastorguev ◽  
...  
Keyword(s):  
Gene Expression ◽  
Brain Tumor ◽  
Molecular Markers ◽  
Glioblastoma Multiforme ◽  
Somatic Mutations ◽  
Web Of Science ◽  
Molecular Subtypes ◽  
Regulation Of Gene Expression ◽  
Signal Pathways ◽  
Poorly Differentiated

Glioblastoma multiforme (GBM) is the most common and invasive poorly differentiated brain tumor with nearly 100 % rate of recurrence and unfavorable prognosis. The aim of the present review is to analyze recent studies and experimental results (Scopus, Web of Science, PubMed) concerning somatic mutations in glioblastoma, aberrant regulation of gene expression of signal pathways including EGFR, TGFß, etc. and markers for GBM progression. Particularly the molecular subtypes of glioblastoma and NGS results are considered in this review.

Nanocurcumin: A Double-Edged Sword for Microcancers

2020 ◽  
Vol 26 (45) ◽  
pp. 5783-5792
Author(s):  
Kholood Abid Janjua ◽  
Adeeb Shehzad ◽  
Raheem Shahzad ◽  
Salman Ul Islam ◽  
Mazhar Ul Islam
Keyword(s):  
Intracellular Signaling ◽  
Dosage Forms ◽  
The Body ◽  
In Vivo Studies ◽  
Mrna Levels ◽  
Anticancer Activities ◽  
Road Map ◽  
Anticancer Effects

There is compelling evidence that drug molecules isolated from natural sources are hindered by low systemic bioavailability, poor absorption, and rapid elimination from the human body. Novel approaches are urgently needed that could enhance the retention time as well as the efficacy of natural products in the body. Among the various adopted approaches to meet this ever-increasing demand, nanoformulations show the most fascinating way of improving the bioavailability of dietary phytochemicals through modifying their pharmacokinetics and pharmacodynamics. Curcumin, a yellowish pigment isolated from dried ground rhizomes of turmeric, exhibits tremendous pharmacological effects, including anticancer activities. Several in vitro and in vivo studies have shown that curcumin mediates anticancer effects through the modulation (upregulation and/or downregulations) of several intracellular signaling pathways both at protein and mRNA levels. Scientists have introduced multiple modern techniques and novel dosage forms for enhancing the delivery, bioavailability, and efficacy of curcumin in the treatment of various malignancies. These novel dosage forms include nanoparticles, liposomes, micelles, phospholipids, and curcumin-encapsulated polymer nanoparticles. Nanocurcumin has shown improved anticancer effects compared to conventional curcumin formulations. This review discusses the underlying molecular mechanism of various nanoformulations of curcumin for the treatment of different cancers. We hope that this study will make a road map for preclinical and clinical investigations of cancer and recommend nano curcumin as a drug of choice for cancer therapy.

Rare Germline GLMN Variants Identified from Blue Rubber Bleb Nevus Syndrome Might Impact mTOR Signaling

2020 ◽  
Vol 22 (10) ◽  
pp. 675-682 ◽  
Author(s):  
Jie Yin ◽  
Zhongping Qin ◽  
Kai Wu ◽  
Yufei Zhu ◽  
Landian Hu ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Sanger Sequencing ◽  
Somatic Mutations ◽  
Venous Malformation ◽  
Underlying Disease ◽  
Mtor Signaling ◽  
Functional Effect ◽  
Germline Variants ◽  
Whole Exome

Backgrounds and Objective: Blue rubber bleb nevus syndrome (BRBN) or Bean syndrome is a rare Venous Malformation (VM)-associated disorder, which mostly affects the skin and gastrointestinal tract in early childhood. Somatic mutations in TEK have been identified from BRBN patients; however, the etiology of TEK mutation-negative patients of BRBN need further investigation. Method: Two unrelated sporadic BRBNs and one sporadic VM were firstly screened for any rare nonsilent mutation in TEK by Sanger sequencing and subsequently applied to whole-exome sequencing to identify underlying disease causative variants. Overexpression assay and immunoblotting were used to evaluate the functional effect of the candidate disease causative variants. Results: In the VM case, we identified the known causative somatic mutation in the TEK gene c.2740C>T (p.Leu914Phe). In the BRBN patients, we identified two rare germline variants in GLMN gene c.761C>G (p.Pro254Arg) and c.1630G>T(p.Glu544*). The GLMN-P254R-expressing and GLMN-E544X-expressing HUVECs exhibited increased phosphorylation of mTOR-Ser-2448 in comparison with GLMN-WTexpressing HUVECs in vitro. Conclusion: Our results demonstrated that rare germline variants in GLMN might contribute to the pathogenesis of BRBN. Moreover, abnormal mTOR signaling might be the pathogenesis mechanism underlying the dysfunction of GLMN protein.

In Vitro Evaluation of Chitosan Induced Cytotoxicity against Cancerous Cell lines: MCF-7, Saos-2 and HeLa

2019 ◽  
Vol 19 ◽  
Author(s):  
Zeinab Abedian ◽  
Niloofar Jenabian ◽  
Ali Akbar Moghadamnia ◽  
Ebrahim Zabihi ◽  
Roghayeh Pourbagher ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Cell Lines ◽  
Anticancer Agents ◽  
Fibroblast Cells ◽  
Apoptosis Induction ◽  
Cytotoxic Effects ◽  
Cancerous Cell ◽  
Significant Concentration ◽  
Mcf 7

Objective/ Background: Cancer is still the most common cause of morbidity in world and new powerful anticancer agents without severe side effects from natural sources is important. Methods: The evaluation of cytotoxicity and apoptosis induction was carried out in MCF-7,HeLa and Saos-2 as cancerous cell lines with different histological origin and human fibroblast served as control normal cell. The cells were treated with different concentrations of chitosan and the cytotoxicity was determined using MTT assay after 24, 48 and 72 h .The mode of death was evaluated by flow cytometry . Results: While both types of chitosan showed significant concentration-dependently cytotoxic effects against the three cancerous cell lines, fibroblast cells showed somehow more compatibility with chitosan. On the other hand, there were no significant differences between LMWC and HMWC cytotoxicity in all cell lines. The flow cytometry results showed the apoptosis pattern of death more in Saos-2 and HeLa while necrosis was more observable with MCF7. Also higher viability with both types of chitosan was seen in fibroblast as normal cells Conclusion: Chitosan shows anticancerous effect against 3 cancerous cell lines, while it is compatible with normal diploid fibroblast cells. Furthermore, it seems that the molecular weight of chitosan does not affect its anticancerous property.

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