scholarly journals Synergy between AUUUA motif disruption and enhancer insertion results in autocrine transformation of interleukin-3-dependent hematopoietic cells

Blood ◽  
1995 ◽  
Vol 86 (8) ◽  
pp. 3139-3150 ◽  
Author(s):  
MW Mayo ◽  
XY Wang ◽  
PA Algate ◽  
GF Arana ◽  
PE Hoyle ◽  
...  
Keyword(s):  
Mrna Stability ◽  
Untranslated Region ◽  
Stability Region ◽  
Rank Order ◽  
Hematopoietic Cells ◽  
Transformation Process ◽  
Wild Type ◽  
Transcriptional Enhancer ◽  
Interleukin 3 ◽  
Autocrine Transformation

Previously, we characterized the transposition of an intracisternal type A particle (IAP) to the 32 untranslated region (UTR) of the interleukin-3 (IL-3) gene, which displaced two of the six AUUUA motifs associated with mRNA stability in an IL-3-secreting clone. To determine whether this rearrangement was involved in the autocrine transformation of the parental IL-3-dependent FL5.12 cell line, the germline (gIL-3) and rearranged IL-3 (rIL-3) genes were isolated and subcloned into a gene transfer vector. Moreover, the IAP-long terminal repeat (LTR) and the IL-3 32 UTR AUUUA motifs were deleted (rIL-3 + delta LTR and gIL-3 + delta AUUUA) in some IL-3 constructs to ascertain their role in the transformation process. The IAP-LTR was also added to these constructs (rIL-3 + delta LTR + IAP-LTR, gIL-3 + delta AUUUA + IAP-LTR, and gIL-3 + IAP-LTR), to determine whether it was necessary for autocrine transformation. The ability of the modified IL-3 genes to abrogate the IL-3 dependency of FL5.12 cells had the following rank order: rIL-3 was greater than rIL-3 + delta LTR + IAP-LTR, which was greater than gIL-3 + delta AUUUA + IAP-LTR, which was greater than gIL-3 + delta AUUUA, which was equal to rIL-3 + delta LTR, which was greater than gIL-3. The half-life of IL-3 mRNA was 20-fold longer in cells containing a mutated as opposed to a wild-type AUUUA region. All of the factor-independent cells that expressed the IL-3 transgenes secreted IL-3 and were tumorigenic after injection into BALB/c nude mice. These results indicated that two events could synergize in the autocrine transformation of hematopoietic cells: (1) addition of a transcriptional enhancer present in a retroviral LTR, and (2) disruption of an mRNA stability region.

scholarly journals Synergy between AUUUA motif disruption and enhancer insertion results in autocrine transformation of interleukin-3-dependent hematopoietic cells

Blood ◽  
1995 ◽  
Vol 86 (8) ◽  
pp. 3139-3150 ◽  
Author(s):  
MW Mayo ◽  
XY Wang ◽  
PA Algate ◽  
GF Arana ◽  
PE Hoyle ◽  
...  
Keyword(s):  
Mrna Stability ◽  
Untranslated Region ◽  
Stability Region ◽  
Rank Order ◽  
Hematopoietic Cells ◽  
Transformation Process ◽  
Wild Type ◽  
Transcriptional Enhancer ◽  
Interleukin 3 ◽  
Autocrine Transformation

Abstract Previously, we characterized the transposition of an intracisternal type A particle (IAP) to the 32 untranslated region (UTR) of the interleukin-3 (IL-3) gene, which displaced two of the six AUUUA motifs associated with mRNA stability in an IL-3-secreting clone. To determine whether this rearrangement was involved in the autocrine transformation of the parental IL-3-dependent FL5.12 cell line, the germline (gIL-3) and rearranged IL-3 (rIL-3) genes were isolated and subcloned into a gene transfer vector. Moreover, the IAP-long terminal repeat (LTR) and the IL-3 32 UTR AUUUA motifs were deleted (rIL-3 + delta LTR and gIL-3 + delta AUUUA) in some IL-3 constructs to ascertain their role in the transformation process. The IAP-LTR was also added to these constructs (rIL-3 + delta LTR + IAP-LTR, gIL-3 + delta AUUUA + IAP-LTR, and gIL-3 + IAP-LTR), to determine whether it was necessary for autocrine transformation. The ability of the modified IL-3 genes to abrogate the IL-3 dependency of FL5.12 cells had the following rank order: rIL-3 was greater than rIL-3 + delta LTR + IAP-LTR, which was greater than gIL-3 + delta AUUUA + IAP-LTR, which was greater than gIL-3 + delta AUUUA, which was equal to rIL-3 + delta LTR, which was greater than gIL-3. The half-life of IL-3 mRNA was 20-fold longer in cells containing a mutated as opposed to a wild-type AUUUA region. All of the factor-independent cells that expressed the IL-3 transgenes secreted IL-3 and were tumorigenic after injection into BALB/c nude mice. These results indicated that two events could synergize in the autocrine transformation of hematopoietic cells: (1) addition of a transcriptional enhancer present in a retroviral LTR, and (2) disruption of an mRNA stability region.

scholarly journals Identification of a Human VPF/VEGF 3′ Untranslated Region Mediating Hypoxia-induced mRNA Stability

1998 ◽  
Vol 9 (2) ◽  
pp. 469-481 ◽  
Author(s):  
Kevin P. Claffey ◽  
Shu-Ching Shih ◽  
Andrew Mullen ◽  
Suzan Dziennis ◽  
Jennifer L. Cusick ◽  
...  
Keyword(s):  
Mrna Stability ◽  
Untranslated Region ◽  
Stability Region ◽  
Rna Binding ◽  
Malignant Tumors ◽  
Human Tumor ◽  
Luciferase Reporter ◽  
Vegf Expression ◽  
Vegf Mrna ◽  
Vascular Permeability Factor

Hypoxia is a prominent feature of malignant tumors that are characterized by angiogenesis and vascular hyperpermeability. Vascular permeability factor/vascular endothelial growth factor (VPF/VEGF) has been shown to be up-regulated in the vicinity of necrotic tumor areas, and hypoxia potently induces VPF/VEGF expression in several tumor cell lines in vitro. Here we report that hypoxia-induced VPF/VEGF expression is mediated by increased transcription and mRNA stability in human M21 melanoma cells. RNA-binding/electrophoretic mobility shift assays identified a single 125-bp AU-rich element in the 3′ untranslated region that formed hypoxia-inducible RNA-protein complexes. Hypoxia-induced expression of chimeric luciferase reporter constructs containing this 125-bp AU-rich hypoxia stability region were significantly higher than constructs containing an adjacent 3′ untranslated region element without RNA-binding activity. Using UV-cross-linking studies, we have identified a series of hypoxia-induced proteins of 90/88 kDa, 72 kDa, 60 kDa, 56 kDa, and 46 kDa that bound to the hypoxia stability region element. The 90/88-kDa and 60-kDa species were specifically competed by excess hypoxia stability region RNA. Thus, increased VPF/VEGF mRNA stability induced by hypoxia is mediated, at least in part, by specific interactions between a defined mRNA stability sequence in the 3′ untranslated region and distinct mRNA-binding proteins in human tumor cells.

scholarly journals Mutator-Suppressible Alleles of rough sheath1 and liguleless3 in Maize Reveal Multiple Mechanisms for Suppression

Genetics ◽  
2000 ◽  
Vol 154 (1) ◽  
pp. 437-446 ◽  
Author(s):  
Lisa Girard ◽  
Michael Freeling
Keyword(s):  
Untranslated Region ◽  
Mutant Allele ◽  
Negative Regulation ◽  
Wild Type ◽  
Knox Gene ◽  
Transcript Accumulation ◽  
Mu Suppression ◽  
Different Types ◽  
Rna Blot Analysis

Abstract Insertions of Mutator transposons into maize genes can generate suppressible alleles. Mu suppression is when, in the absence of Mu activity, the phenotype of a mutant allele reverts to that of its progenitor. Here we present the characterization of five dominant Mu-suppressible alleles of the knox (knotted1-like homeobox) genes liguleless3 and rough sheath1, which exhibit neomorphic phenotypes in the leaves. RNA blot analysis suggests that Mu suppression affects only the neomorphic aspect of the allele, not the wild-type aspect. Additionally, Mu suppression appears to be exerting its effects at the level of transcription or transcript accumulation. We show that truncated transcripts are produced by three alleles, implying a mechanism for Mu suppression of 5′ untranslated region insertion alleles distinct from that which has been described previously. Additionally, it is found that Mu suppression can be caused by at least three different types of Mutator elements. Evidence presented here suggests that whether an allele is suppressible or not may depend upon the site of insertion. We cite previous work on the knox gene kn1, and discuss our results in the context of interactions between Mu-encoded products and the inherently negative regulation of neomorphic liguleless3 and rough sheath1 transcription.

scholarly journals High-throughput drug screening identifies the ATR-CHK1 pathway as a therapeutic vulnerability of CALR mutated hematopoietic cells

2021 ◽  
Vol 11 (7) ◽  
Author(s):  
Ruochen Jia ◽  
Leon Kutzner ◽  
Anna Koren ◽  
Kathrin Runggatscher ◽  
Peter Májek ◽  
...  
Keyword(s):  
High Throughput ◽  
Drug Screening ◽  
Synthetic Lethality ◽  
Myeloproliferative Neoplasms ◽  
Hematopoietic Cells ◽  
Replication Stress ◽  
Phase Cell ◽  
Nuclear Staining ◽  
Wild Type ◽  
High Throughput Drug Screening

AbstractMutations of calreticulin (CALR) are the second most prevalent driver mutations in essential thrombocythemia and primary myelofibrosis. To identify potential targeted therapies for CALR mutated myeloproliferative neoplasms, we searched for small molecules that selectively inhibit the growth of CALR mutated cells using high-throughput drug screening. We investigated 89 172 compounds using isogenic cell lines carrying CALR mutations and identified synthetic lethality with compounds targeting the ATR-CHK1 pathway. The selective inhibitory effect of these compounds was validated in a co-culture assay of CALR mutated and wild-type cells. Of the tested compounds, CHK1 inhibitors potently depleted CALR mutated cells, allowing wild-type cell dominance in the co-culture over time. Neither CALR deficient cells nor JAK2V617F mutated cells showed hypersensitivity to ATR-CHK1 inhibition, thus suggesting specificity for the oncogenic activation by the mutant CALR. CHK1 inhibitors induced replication stress in CALR mutated cells revealed by elevated pan-nuclear staining for γH2AX and hyperphosphorylation of RPA2. This was accompanied by S-phase cell cycle arrest due to incomplete DNA replication. Transcriptomic and phosphoproteomic analyses revealed a replication stress signature caused by oncogenic CALR, suggesting an intrinsic vulnerability to CHK1 perturbation. This study reveals the ATR-CHK1 pathway as a potential therapeutic target in CALR mutated hematopoietic cells.

scholarly journals Imbalance between Expression of FOXC2 and Its lncRNA in Lymphedema-Distichiasis Caused by Frameshift Mutations

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 650
Author(s):  
Sara Missaglia ◽  
Daniela Tavian ◽  
Sandro Michelini ◽  
Paolo Enrico Maltese ◽  
Andrea Bonanomi ◽  
...  
Keyword(s):  
Mrna Stability ◽  
Healthy Subjects ◽  
Lymphatic System ◽  
System Development ◽  
Bioinformatic Analysis ◽  
Wild Type ◽  
Mutant Proteins ◽  
Frameshift Mutations ◽  
Forkhead Box ◽  
Frameshift Mutant

Forkhead-box C2 (FOXC2) is a transcription factor involved in lymphatic system development. FOXC2 mutations cause Lymphedema-distichiasis syndrome (LD). Recently, a natural antisense was identified, called lncRNA FOXC2-AS1, which increases FOXC2 mRNA stability. No studies have evaluated FOXC2 and FOXC2-AS1 blood expression in LD and healthy subjects. Here, we show that FOXC2 and FOXC-AS1 expression levels were similar in both controls and patients, and a significantly higher amount of both RNAs was observed in females. A positive correlation between FOXC2 and FOXC2-AS1 expression was found in both controls and patients, excluding those with frameshift mutations. In these patients, the FOXC2-AS1/FOXC2 ratio was about 1:1, while it was higher in controls and patients carrying other types of mutations. The overexpression or silencing of FOXC2-AS1 determined a significant increase or reduction in FOXC2 wild-type and frameshift mutant proteins, respectively. Moreover, confocal and bioinformatic analysis revealed that these variations caused the formation of nuclear proteins aggregates also involving DNA. In conclusion, patients with frameshift mutations presented lower values of the FOXC2-AS1/FOXC2 ratio, due to a decrease in FOXC2-AS1 expression. The imbalance between FOXC2 mRNA and its lncRNA could represent a molecular mechanism to reduce the amount of FOXC2 misfolded proteins, protecting cells from damage.

scholarly journals Downregulated mRNA expression of ASPP and the hypermethylation of the 5′-untranslated region in cancer cell lines retaining wild-type p53

FEBS Letters ◽  
2005 ◽  
Vol 579 (7) ◽  
pp. 1587-1590 ◽  
Author(s):  
Ze-Jun Liu ◽  
Xin Lu ◽  
Yun Zhang ◽  
Shan Zhong ◽  
Shou-Zhi Gu ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Cell Lines ◽  
Cancer Cell ◽  
Untranslated Region ◽  
Cancer Cell Lines ◽  
Wild Type ◽  
Wild Type P53

AU-rich elements in the mRNA 3′-untranslated region of the rat receptor for advanced glycation end products and their relevance to mRNA stability

2004 ◽  
Vol 319 (1) ◽  
pp. 247-255 ◽  
Author(s):  
José Juan Caballero ◽  
Marı́a Dolores Girón ◽  
Alberto Manuel Vargas ◽  
Natalia Sevillano ◽  
Marı́a Dolores Suárez ◽  
...  
Keyword(s):  
Advanced Glycation End Products ◽  
Mrna Stability ◽  
Untranslated Region ◽  
Advanced Glycation ◽  
Glycation End Products ◽  
End Products

scholarly journals Role of Genetic Evolution and Germline Mutations in SAMD9 and SAMD9L Genes

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. SCI-33-SCI-33
Author(s):  
Jason R Schwartz ◽  
Marcin W. Wlodarski ◽  
Jeffery M. Klco
Keyword(s):  
Bone Marrow ◽  
Germline Mutation ◽  
Bone Marrow Failure ◽  
Hematopoietic Cells ◽  
Germline Mutations ◽  
Chromosome 7 ◽  
Chromosome Loss ◽  
Wild Type ◽  
In Vivo Models ◽  
Monosomy 7

Acquired deletions on chromosome 7 (monosomy 7/del7q) are common in myeloid neoplasms, especially pediatric MDS and AML. Although these tumors have historically been reported to occur within families, suggesting a genetic predisposition, the genetic lesion(s) that initiate these diseases has remained elusive until the last few years. Following a series of publications in which germline mutations in SAMD9 and SAMD9L were reported in a MIRAGE syndrome and Ataxia Pancytopenia syndrome, respectively, our group and others described similar heterozygous missense germline mutations in pediatric MDS, especially non-syndromic familial MDS with monosomy 7. Mutations in SAMD9 and SAMD9L have now also been reported in transient monosomy 7, inherited bone marrow failure and AML. Collectively, it is estimated that germline mutations in these genes are present in nearly 20% of children with MDS, with a strong enrichment in those with monosomy 7. Surprisingly, SAMD9 and SAMD9L are paralogous genes adjacently located on human chromosome 7 at band 7q21, and the monosomy 7 clone that expands in children universally lacks the pathologic germline variant. Expression of the mutant proteins in cells results in profound growth suppression, suggesting that there is strong selective pressure for hematopoietic cells to not express the mutant alleles. In addition to chromosome loss, additional methods that suppress expression of the pathologic allele have been described. These include copy neutral loss of heterozygosity (CN-LOH) with duplication of the wild-type allele or the somatic acquisition of additional mutations in cis with the germline mutation that counteract the growth suppressive effect of the germline mutation. The clinical phenotype is largely dictated by the revertant mutation in the dominant hematopoietic clone within the patient's bone marrow. Those with an expansion of a CN-LOH clone are more commonly asymptomatic, in contrast to those patients with a dominant monosomy 7 clone. Progression to higher grade MDS or AML is associated with the acquisition of additional somatic mutations including mutations in SETBP1, KRAS and RUNX1. The recognition of these germline mutations has had an immediate impact on the clinical management of children with MDS, including their family members, and ongoing clinical work in the pediatric MDS community is aimed at establishing guidelines for the pathologic diagnosis, clinical monitoring and treatment for these patients. In addition to these ongoing clinical pursuits, there is significant research interest in these genes, the function of their proteins in hematopoietic cells and how the germline mutations alter the function of the wild-type protein. The SAMD9 and SAMD9L proteins are largely uncharacterized and have been shown to be important in endocytosis, growth factor signaling and to have antiviral properties. Intriguingly, SAMD9 and SAMD9L are both induced by inflammatory signals, including interferons, suggesting a link between inflammatory stress and the disease phenotype. Ongoing studies are aimed at developing models, including in vitro and in vivo models, to understand the mechanisms by which these germline mutations can ultimately lead to the development of pediatric MDS and related disorders. Disclosures No relevant conflicts of interest to declare.

Mechanism of autocrine stimulation in hematopoietic cells producing interleukin-3 after retrovirus-mediated gene transfer

1989 ◽  
Vol 9 (1) ◽  
pp. 204-213
Author(s):  
T M Browder ◽  
J S Abrams ◽  
P M Wong ◽  
A W Nienhuis
Keyword(s):  
Signal Sequence ◽  
Polyclonal Antibodies ◽  
Surface Display ◽  
Hematopoietic Cells ◽  
Parental Cell ◽  
Biologically Active ◽  
Parental Cell Line ◽  
Interleukin 3 ◽  
Endogenous Expression ◽  
Autocrine Stimulation

Endogenous expression of the interleukin-3 (IL3) gene introduced with a retrovirus vector renders hematopoietic cells autonomous of exogenous growth factor. To investigate the mechanism of autocrine stimulation, 25 clones were isolated after retrovirus transduction of IL3 into 32D-cl23 or FDC-P1 cells. Medium conditioned by these autonomous IL3-producing clones supported the growth of factor-dependent 32D cells. Although there was a severalfold variation in the amount of IL3 secreted (some clones secreted barely detectable levels), the doubling time of each clone in the absence of added IL3 was identical to that of the parental cell line maximally stimulated by exogenous IL3. Concentrated monoclonal and polyclonal antibodies, both highly effective in neutralizing exogenous IL3, were assayed for ability to inhibit autocrine growth. Minimal inhibitory effects were observed only on washed autocrine clones secreting low levels of IL3. To test the activity of cytoplasmically synthesized IL3, the nucleotides encoding the signal sequence of IL3 were deleted and replaced with an in-frame ATG in the context of a consensus translation initiation sequence. Ten 32D clones expressing this restructured IL3 genome were obtained. Despite the presence of biologically active IL3 in cell lysates, all clones remained dependent on exogenous IL3, with the same dose-response as that found for 32D cells. Our data are most compatible with a mechanism whereby endogenously produced IL3 interacts with its receptor prior to surface display.

Model Driven Engineering Applied in E-Learning Development Process

2017 ◽  
Vol 7 (1) ◽  
pp. 15-32 ◽  
Author(s):  
Rachid Dehbi
Keyword(s):  
Rank Order ◽  
Evaluation Model ◽  
Transformation Process ◽  
Learning System ◽  
Model Driven Engineering ◽  
Component Reuse ◽  
Model Driven ◽  
E Learning ◽  
Multi Criteria Analysis ◽  
Learning Development

The e-Learning solution is one of the most discussed priorities of modern universities. The whole problem lies in the global approach of which strategy must use to create e-Learning system. This paper describes an evaluation model for some of the existent methodologies based on model driven engineering used to create e-Learning system. The evaluation model is based on a comparative study and multi-criteria analysis: adaptability, transformation process, Bases and standards, Open Distance Learning cycle, model reuse, component reuse, Model Driven Architecture use. The proposed comparative is realized by using the Multi-criteria analysis method: Rank Order Centroid, where we join some of the used characteristics by these methodologies to compare.

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