scholarly journals A post-transcriptional program of chemoresistance by AU-rich elements and TTP

2018 ◽  
Author(s):  
Sooncheol Lee ◽  
Douglas Micalizzi ◽  
Samuel S Truesdell ◽  
Syed IA Bukhari ◽  
Myriam Boukhali ◽  
...  
Keyword(s):  
Transcriptional Regulation ◽  
P38 Mapk ◽  
Ex Vivo ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Leukemic Cells ◽  
Serum Starvation ◽  
P38 Mapk Inhibitors ◽  
Post Transcriptional Regulation

AbstractBackgroundQuiescence (G0) is a transient, cell cycle-arrested state. By entering G0, cancer cells survive unfavorable conditions such as chemotherapy and cause relapse. While G0 cells have been studied at the transcriptome level, how post-transcriptional regulation contributes to their chemoresistance remains unknown.ResultsWe induced chemoresistant and quiescent (G0) leukemic cells by serum-starvation or chemotherapy treatment. To study post-transcriptional regulation in G0 leukemic cells, we systematically analyzed their transcriptome, translatome, and proteome. We find that our resistant G0 cells recapitulate gene expression profiles of in vivo chemoresistant leukemic and G0 models. In G0 cells, canonical translation initiation is inhibited; yet we find that inflammatory genes are highly translated, indicating alternative post-transcriptional regulation. Importantly, AU-rich elements (AREs) are significantly enriched in the up-regulated G0 translatome and transcriptome. Mechanistically, we find the stress-responsive p38 MAPK-MK2 signaling pathway stabilizes ARE mRNAs by phosphorylation and inactivation of mRNA decay factor, tristetraprolin (TTP) in G0. This permits expression of ARE-bearing TNFα and DUSP1 that promote chemoresistance. Conversely, inhibition of TTP phophorylation by p38 MAPK inhibitors and non-phosphorylatable TTP mutant decreases ARE mRNAs and sensitizes leukemic cells to chemotherapy. Furthermore, co-inhibiting p38 MAPK and TNFα—prior to or along with chemotherapy—substantially reduced chemoresistance in primary leukemic cells ex vivo and in vivo.ConclusionsThese studies uncover post-transcriptional regulation underlying chemoresistance in leukemia. Our data reveal the p38 MAPK-MK2-TTP axis as a key regulator of expression of ARE bearing mRNAs that promote chemoresistance. By disrupting this pathway, we developed an effective combination therapy against chemosurvival.

scholarly journals Discovery of novel mechanosensitive genes in vivo using mouse carotid artery endothelium exposed to disturbed flow

Blood ◽  
2010 ◽  
Vol 116 (15) ◽  
pp. e66-e73 ◽  
Author(s):  
Chih-Wen Ni ◽  
Haiwei Qiu ◽  
Amir Rezvan ◽  
Kihwan Kwon ◽  
Douglas Nam ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Ex Vivo ◽  
Expression Profiles ◽  
Quantitative Polymerase Chain Reaction ◽  
Gene Expression Profiles ◽  
Disturbed Flow ◽  
A Genome ◽  
Pattern Comparison

Abstract Recently, we showed that disturbed flow caused by a partial ligation of mouse carotid artery rapidly induces atherosclerosis. Here, we identified mechanosensitive genes in vivo through a genome-wide microarray study using mouse endothelial RNAs isolated from the flow-disturbed left and the undisturbed right common carotid artery. We found 62 and 523 genes that changed significantly by 12 hours and 48 hours after ligation, respectively. The results were validated by quantitative polymerase chain reaction for 44 of 46 tested genes. This array study discovered numerous novel mechanosensitive genes, including Lmo4, klk10, and dhh, while confirming well-known ones, such as Klf2, eNOS, and BMP4. Four genes were further validated for protein, including LMO4, which showed higher expression in mouse aortic arch and in human coronary endothelium in an asymmetric pattern. Comparison of in vivo, ex vivo, and in vitro endothelial gene expression profiles indicates that numerous in vivo mechanosensitive genes appear to be lost or dysregulated during culture. Gene ontology analyses show that disturbed flow regulates genes involved in cell proliferation and morphology by 12 hours, followed by inflammatory and immune responses by 48 hours. Determining the functional importance of these novel mechanosensitive genes may provide important insights into understanding vascular biology and atherosclerosis.

scholarly journals Harnessing Gene Expression Profiles for the Identification of Ex Vivo Drug Response Genes in Pediatric Acute Myeloid Leukemia

Cancers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1247 ◽  
Author(s):  
David G.J. Cucchi ◽  
Costa Bachas ◽  
Marry M. van den Heuvel-Eibrink ◽  
Susan T.C.J.M. Arentsen-Peters ◽  
Zinia J. Kwidama ◽  
...  
Keyword(s):  
Gene Expression ◽  
Drug Resistance ◽  
Drug Response ◽  
Molecular Mechanisms ◽  
Ex Vivo ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Leukemic Cells ◽  
Treatment Optimization ◽  
Pediatric Aml

Novel treatment strategies are of paramount importance to improve clinical outcomes in pediatric AML. Since chemotherapy is likely to remain the cornerstone of curative treatment of AML, insights in the molecular mechanisms that determine its cytotoxic effects could aid further treatment optimization. To assess which genes and pathways are implicated in tumor drug resistance, we correlated ex vivo drug response data to genome-wide gene expression profiles of 73 primary pediatric AML samples obtained at initial diagnosis. Ex vivo response of primary AML blasts towards cytarabine (Ara C), daunorubicin (DNR), etoposide (VP16), and cladribine (2-CdA) was associated with the expression of 101, 345, 206, and 599 genes, respectively (p < 0.001, FDR 0.004–0.416). Microarray based expression of multiple genes was technically validated using qRT-PCR for a selection of genes. Moreover, expression levels of BRE, HIF1A, and CLEC7A were confirmed to be significantly (p < 0.05) associated with ex vivo drug response in an independent set of 48 primary pediatric AML patients. We present unique data that addresses transcriptomic analyses of the mechanisms underlying ex vivo drug response of primary tumor samples. Our data suggest that distinct gene expression profiles are associated with ex vivo drug response, and may confer a priori drug resistance in leukemic cells. The described associations represent a fundament for the development of interventions to overcome drug resistance in AML, and maximize the benefits of current chemotherapy for sensitive patients.

scholarly journals Gene expression in mouse ovarian follicle development in vivo versus an ex vivo alginate culture system

Reproduction ◽  
2011 ◽  
Vol 142 (2) ◽  
pp. 309-318 ◽  
Author(s):  
Elizabeth M Parrish ◽  
Anaar Siletz ◽  
Min Xu ◽  
Teresa K Woodruff ◽  
Lonnie D Shea
Keyword(s):  
Gene Expression ◽  
Transforming Growth Factor ◽  
Ex Vivo ◽  
Expression Profiles ◽  
Ovarian Follicle ◽  
Gene Expression Profiles ◽  
Follicle Development ◽  
Α Subunit

Ovarian follicle maturation results from a complex interplay of endocrine, paracrine, and direct cell–cell interactions. This study compared the dynamic expression of key developmental genes during folliculogenesis in vivo and during in vitro culture in a 3D alginate hydrogel system. Candidate gene expression profiles were measured within mouse two-layered secondary follicles, multi-layered secondary follicles, and cumulus–oocyte complexes (COCs). The expression of 20 genes involved in endocrine communication, growth signaling, and oocyte development was investigated by real-time PCR. Gene product levels were compared between i) follicles of similar stage and ii) COCs derived either in vivo or by in vitro culture. For follicles cultured for 4 days, the expression pattern and the expression level of 12 genes were the same in vivo and in vitro. Some endocrine (cytochrome P450, family 19, subfamily A, polypeptide 1 (Cyp19a1) and inhibin βA subunit (Inhba)) and growth-related genes (bone morphogenetic protein 15 (Bmp15), kit ligand (Kitl), and transforming growth factor β receptor 2 (Tgfbr2)) were downregulated relative to in vivo follicles. For COCs obtained from cultured follicles, endocrine-related genes (inhibin α-subunit (Inha) and Inhba) had increased expression relative to in vivo counterparts, whereas growth-related genes (Bmp15, growth differentiation factor 9, and kit oncogene (Kit)) and zona pellucida genes were decreased. However, most of the oocyte-specific genes (e.g. factor in the germline α (Figla), jagged 1 (Jag1), and Nlrp5 (Mater)) were expressed in vitro at the same level and with the same pattern as in vivo-derived follicles. These studies establish the similarities and differences between in vivo and in vitro cultured follicles, guiding the creation of environments that maximize follicle development and oocyte quality.

scholarly journals An adhesion code ensures robust pattern formation during tissue morphogenesis

2019 ◽  
Author(s):  
Tony Y.-C. Tsai ◽  
Mateusz Sikora ◽  
Peng Xia ◽  
Tugba Colak-Champollion ◽  
Holger Knaut ◽  
...  
Keyword(s):  
Cell Fate ◽  
Large Scale ◽  
Ex Vivo ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Tissue Growth ◽  
Gradient Based ◽  
The Common ◽  
Outstanding Question

ABSTRACTAn outstanding question in embryo development is how spatial patterns are formed robustly. In the zebrafish spinal cord, neural progenitors form stereotypic stripe-like patterns despite noisy morphogen signaling and large-scale cellular rearrangement required for tissue growth and morphogenesis. We set out to understand the mechanisms underlying this patterning robustness. Our adhesion assays revealed a preference for three neural progenitor types to stabilize contacts with cells of the same type. Genetic analysis uncovered a three-molecule adhesion code, composed of N-cadherin, Cadherin 11, and Protocadherin 19, with unique gene expression profiles for each cell type. Perturbation of the adhesion code results in loss of homotypic preference ex vivo and patterning errors in vivo. Both the cell fate and adhesion code are co-regulated by the common upstream morphogen signal Shh. We propose that robust patterning in tissues undergoing morphogenesis results from a previously unappreciated interplay between morphogen gradient-based patterning and adhesion-based self-organization.

scholarly journals Transcriptome analysis of gravitational effects on mouse skeletal muscles under microgravity and artificial 1 g onboard environment

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Risa Okada ◽  
Shin-ichiro Fujita ◽  
Riku Suzuki ◽  
Takuto Hayashi ◽  
Hirona Tsubouchi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Muscle Mass ◽  
Muscle Atrophy ◽  
Transcriptome Analysis ◽  
Fiber Type ◽  
Expression Profiles ◽  
Space Station ◽  
Gene Expression Profiles

AbstractSpaceflight causes a decrease in skeletal muscle mass and strength. We set two murine experimental groups in orbit for 35 days aboard the International Space Station, under artificial earth-gravity (artificial 1 g; AG) and microgravity (μg; MG), to investigate whether artificial 1 g exposure prevents muscle atrophy at the molecular level. Our main findings indicated that AG onboard environment prevented changes under microgravity in soleus muscle not only in muscle mass and fiber type composition but also in the alteration of gene expression profiles. In particular, transcriptome analysis suggested that AG condition could prevent the alterations of some atrophy-related genes. We further screened novel candidate genes to reveal the muscle atrophy mechanism from these gene expression profiles. We suggest the potential role of Cacng1 in the atrophy of myotubes using in vitro and in vivo gene transductions. This critical project may accelerate the elucidation of muscle atrophy mechanisms.

Cord blood comprises antigen-experienced T cells specific for maternal minor histocompatibility antigen HA-1

Blood ◽  
2005 ◽  
Vol 105 (4) ◽  
pp. 1823-1827 ◽  
Author(s):  
Bregje Mommaas ◽  
Janine A. Stegehuis-Kamp ◽  
Astrid G. van Halteren ◽  
Michel Kester ◽  
Jürgen Enczmann ◽  
...  
Keyword(s):  
T Cells ◽  
Cord Blood ◽  
Ex Vivo ◽  
Cytotoxic T Cells ◽  
Cord Blood Transplantation ◽  
Human Leukocyte ◽  
Leukemic Cells ◽  
Target Cells ◽  
Graft Versus Leukemia

AbstractUmbilical cord blood transplantation is applied as treatment for mainly pediatric patients with hematologic malignancies. The clinical results show a relatively low incidence of graft-versus-host disease and leukemia relapse. Since maternal cells traffic into the fetus during pregnancy, we questioned whether cord blood has the potential to generate cytotoxic T cells specific for the hematopoietic minor histocompatibility (H) antigen HA-1 that would support the graft-versus-leukemia effect. Here, we demonstrate the feasibility of ex vivo generation of minor H antigen HA-1-specific T cells from cord blood cells. Moreover, we observed pre-existing HA-1-specific T cells in cord blood samples. Both the circulating and the ex vivo-generated HA-1-specific T cells show specific and hematopoietic restricted lysis of human leukocyte antigen-A2pos/HA-1pos (HLA-A2pos/HA-1pos) target cells, including leukemic cells. The cord blood-derived HA-1-specific cytotoxic T cells are from child origin. Thus, the so-called naive cord blood can comprise cytotoxic T cells directed at the maternal minor H antigen HA-1. The apparent immunization status of cord blood may well contribute to the in vivo graft-versus-leukemia activity after transplantation. Moreover, since the fetus cannot be primed against Y chromosome-encoded minor H antigens, cord blood is an attractive stem cell source for male patients. (Blood. 2005;105:1823-1827)

scholarly journals Recapitulating tumour microenvironment in chitosan–gelatin three-dimensional scaffolds: an improved in vitro tumour model

2012 ◽  
Vol 9 (77) ◽  
pp. 3288-3302 ◽  
Author(s):  
Neha Arya ◽  
Viren Sardana ◽  
Meera Saxena ◽  
Annapoorni Rangarajan ◽  
Dhirendra S. Katti
Keyword(s):  
Cancer Progression ◽  
Expression Profiles ◽  
Three Dimensional ◽  
Gene Expression Profiles ◽  
Petri Dish ◽  
Tumour Microenvironment ◽  
Two Dimensional ◽  
Tumour Model

Owing to the reduced co-relationship between conventional flat Petri dish culture (two-dimensional) and the tumour microenvironment, there has been a shift towards three-dimensional culture systems that show an improved analogy to the same. In this work, an extracellular matrix (ECM)-mimicking three-dimensional scaffold based on chitosan and gelatin was fabricated and explored for its potential as a tumour model for lung cancer. It was demonstrated that the chitosan–gelatin (CG) scaffolds supported the formation of tumoroids that were similar to tumours grown in vivo for factors involved in tumour-cell–ECM interaction, invasion and metastasis, and response to anti-cancer drugs. On the other hand, the two-dimensional Petri dish surfaces did not demonstrate gene-expression profiles similar to tumours grown in vivo . Further, the three-dimensional CG scaffolds supported the formation of tumoroids, using other types of cancer cells such as breast, cervix and bone, indicating a possible wider potential for in vitro tumoroid generation. Overall, the results demonstrated that CG scaffolds can be an improved in vitro tool to study cancer progression and drug screening for solid tumours.

scholarly journals Dexamethasone-mediated oncogenicity in vitro and in an animal model of glioblastoma

2018 ◽  
Vol 129 (6) ◽  
pp. 1446-1455 ◽  
Author(s):  
Markus M. Luedi ◽  
Sanjay K. Singh ◽  
Jennifer C. Mosley ◽  
Islam S. A. Hassan ◽  
Masumeh Hatami ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Expression Profiles ◽  
Clinical Information ◽  
Gene Signature ◽  
The Cancer Genome Atlas ◽  
Boyden Chamber ◽  
Ki 67 ◽  
Marker Selection

OBJECTIVEDexamethasone, a known regulator of mesenchymal programming in glioblastoma (GBM), is routinely used to manage edema in GBM patients. Dexamethasone also activates the expression of genes, such as CEBPB, in GBM stem cells (GSCs). However, the drug’s impact on invasion, proliferation, and angiogenesis in GBM remains unclear. To determine whether dexamethasone induces invasion, proliferation, and angiogenesis in GBM, the authors investigated the drug’s impact in vitro, in vivo, and in clinical information derived from The Cancer Genome Atlas (TCGA) cohort.METHODSExpression profiles of patients from the TCGA cohort with mesenchymal GBM (n = 155) were compared with patients with proneural GBM by comparative marker selection. To obtain robust data, GSCs with IDH1 wild-type (GSC3) and with IDH1 mutant (GSC6) status were exposed to dexamethasone in vitro and in vivo and analyzed for invasion (Boyden chamber, human-specific nucleolin), proliferation (Ki-67), and angiogenesis (CD31). Ex vivo tumor cells from dexamethasone-treated and control mice were isolated by fluorescence activated cell sorting and profiled using Affymetrix chips for mRNA (HTA 2.0) and microRNAs (miRNA 4.0). A pathway analysis was performed to identify a dexamethasone-regulated gene signature, and its relationship with overall survival (OS) was assessed using Kaplan-Meier analysis in the entire GBM TCGA cohort (n = 520).RESULTSThe mesenchymal subgroup, when compared with the proneural subgroup, had significant upregulation of a dexamethasone-regulated gene network, as well as canonical pathways of proliferation, invasion, and angiogenesis. Dexamethasone-treated GSC3 demonstrated a significant increase in invasion, both in vitro and in vivo, whereas GSC6 demonstrated a modest increase. Furthermore, dexamethasone treatment of both GSC3 and GSC6 lines resulted in significantly elevated cell proliferation and angiogenesis in vivo. Patients with mesenchymal GBM had significant upregulation of dexamethasone-regulated pathways when compared with patients with proneural GBM. A prognostic (p = 0.0007) 33-gene signature was derived from the ex vivo expression profile analyses and used to dichotomize the entire TCGA cohort by high (median OS 12.65 months) or low (median OS 14.91 months) dexamethasone signature.CONCLUSIONSThe authors present evidence that furthers the understanding of the complex effects of dexamethasone on biological characteristics of GBM. The results suggest that the drug increases invasion, proliferation, and angiogenesis in human GSC-derived orthotopic tumors, potentially worsening GBM patients’ prognoses. The authors believe that careful investigation is needed to determine how to minimize these deleterious dexamethasone-associated side effects in GBM.

Abstract 268: Strain-specific Cardiac Fibroblast Response to Isoproterenol-induced Cardiac Fibrosis

2017 ◽  
Vol 121 (suppl_1) ◽  
Author(s):  
Shuin Park ◽  
Sara Ranjbarvaziri ◽  
Fides Lay ◽  
Peng Zhao ◽  
Aldons J Lusis ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cardiac Fibrosis ◽  
Cardiac Fibroblasts ◽  
Expression Profiles ◽  
Inbred Mouse ◽  
Gene Expression Profiles ◽  
Mouse Strains ◽  
Sequencing Analysis ◽  
Different Strains

Fibroblasts are a heterogeneous population of cells that function within the injury response mechanisms across various tissues. Despite their importance in pathophysiology, the effects of different genetic backgrounds on fibroblast contribution to the development of disease has yet to be addressed. It has previously been shown that mice in the Hybrid Mouse Diversity Panel, which consists of 110 inbred mouse strains, display a spectrum in severity of cardiac fibrosis in response to chronic treatment of isoproterenol (ISO). Here, we characterized cardiac fibroblasts (CFbs) from three different mouse strains (C57BL/6J, C3H/HeJ, and KK/HIJ) which exhibited varying degrees of fibrosis after ISO treatment. The select strains of mice underwent sham or ISO treatment via intraperitoneally-implanted osmotic pumps for 21 days. Masson’s Trichrome staining showed significant differences in fibrosis in response to ISO, with KK/HIJ mice demonstrating the highest levels, C3H/HeJ exhibiting milder levels, and C57BL/6J demonstrating little to no fibrosis. When CFbs were isolated and cultured from each strain, the cells demonstrated similar traits at the basal level but responded to ISO stimuli in a strain-specific manner. Likewise, CFbs demonstrated differential behavior and gene expression in vivo in response to ISO. ISO treatment caused CFbs to proliferate similarly across all strains, however, immunofluorescence staining showed differential levels of CFb activation. Additionally, RNA-sequencing analysis revealed unique gene expression profiles of all three strains upon ISO treatment. Our study depicts the phenotypic heterogeneity of CFbs across different strains of mice and our results suggest that ISO-induced cardiac fibrosis is a complex process that is independent of fibroblast proliferation and is mainly driven by the activation/inhibition of genes involved in pro-fibrotic pathways.

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