Transcription Factor ATF2 Cooperates with v-Jun To Promote Growth Factor-Independent Proliferation In Vitro and Tumor Formation In Vivo

ABSTRACT ATF2 belongs to the bZIP family of transcription factors and controls gene expression via 8-bp ATF/CREB motifs either as a homodimer or as a heterodimer—for instance, with Jun—but has never been shown to be directly involved in oncogenesis. Experiments were designed to evaluate a possible role of ATF2 in oncogenesis in chick embryo fibroblasts (CEFs) in the presence or absence of v-Jun. We found that (i) forced expression of ATF2 cannot alone cause transformation, (ii) overexpression of ATF2 plus v-Jun specifically stimulates v-Jun-induced growth in medium with a reduced amount of serum, and (iii) the efficiency of low-serum growth correlates with the activity of a Jun-ATF2-dependent model promoter in stably transformed CEFs. Analysis of ATF2 and Jun dimerization mutants showed that the growth-stimulatory effect of ATF2 is likely to be mediated by v-Jun–ATF2 heterodimers since (i) v-Jun-m1, a mutant with enhanced affinity for ATF2, induces growth in low-serum medium much more efficiently than v-Jun, when expressed alone or in combination with ATF2; and (ii) ATF2/fos, a mutant that efficiently binds to v-Jun but is unable to form stable homodimers, shows enhanced oncogenic cooperation with v-Jun. In addition, we examined the role of ATF2 in tumor formation by subcutaneous injection of CEFs into chickens. In contrast to v-Jun, v-Jun-m1 gave rise to numerous fibrosarcomas while coexpression of ATF2 and v-Jun-m1 led to a dramatic development of fibrosarcomas visible within 1 week. Together these data demonstrate that overexpressed ATF2 potentiates the ability of v-Jun-transformed CEFs to grow in low-serum medium in vitro and contributes to the formation of tumors in vivo.

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Effect of ACTH and hCG on the Expression of Gonadotropin-Inducible Ovarian Transcription Factor 1 (Giot1) Gene in the Rat Adrenal Gland

International Journal of Molecular Sciences ◽

10.3390/ijms19082285 ◽

2018 ◽

Vol 19 (8) ◽

pp. 2285 ◽

Cited By ~ 3

Author(s):

Karol Jopek ◽

Marianna Tyczewska ◽

Manjunath Ramanjaneya ◽

Marta Szyszka ◽

Piotr Celichowski ◽

...

Keyword(s):

Gene Expression ◽

Gene Regulation ◽

Transcription Factor ◽

Adrenal Gland ◽

Essential Role ◽

Rat Adrenals ◽

Transcription Factor 1

Gonadotropin-inducible ovarian transcription factor-1 (Giot1) belongs to a family of fast-responsive genes, and gonadotropins rapidly induce its expression in steroidogenic cells of ovaries and testes of rats. Gonadal Giot1 gene expression is regulated by cyclic adenosine monophosphate (cAMP) -dependent protein kinase A pathway, with essential role of orphan nuclear receptor NR4A1 transcription factor (nuclear receptor subfamily 4, group A, member 1). A recent study reports that Giot1 is also expressed in adrenals, however, the mechanism of its regulation in adrenal gland is yet to be identified. Therefore, the aim of this study was to characterise the changes in Giot1 gene expression in male and female rat adrenals using wide range of in vivo and in vitro experimental models. Special emphasis was directed at the Giot1 gene regulation by ACTH and gonadotropin. In our study, we found that ACTH rapidly stimulates Giot1 expression both in vivo and in vitro. However, gonadotropin does not affect the adrenal Giot1 gene expression, presumably due to the low expression of gonadotropin receptor in adrenals. Both testosterone and estradiol administered in vivo had inhibitory effect on Giot1 gene expression in the adrenals of post-gonadectomized adult rats. Further, our studies revealed that the intracellular mechanism of Giot1 gene regulation in rat adrenals is similar to that of gonads. As in the case of gonads, the expression of Giot1 in adrenal gland is regulated by cAMP-dependent signaling pathway with essential role of the NR4A1 transcription factor. The results of our studies suggest that Giot1 may be involved in the regulation of rat adrenocortical steroidogenesis.

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Subnuclear compartmentalization of sequence-specific transcription factors and regulation of eukaryotic gene expression

Biochemistry and Cell Biology ◽

10.1139/o05-062 ◽

2005 ◽

Vol 83 (4) ◽

pp. 535-547 ◽

Cited By ~ 7

Author(s):

Gareth N Corry ◽

D Alan Underhill

Keyword(s):

Gene Expression ◽

Transcription Factor ◽

Transcription Factors ◽

Transcriptional Activation ◽

Current Knowledge ◽

Nuclear Architecture ◽

Subnuclear Localization ◽

Modular Structures

To date, the majority of the research regarding eukaryotic transcription factors has focused on characterizing their function primarily through in vitro methods. These studies have revealed that transcription factors are essentially modular structures, containing separate regions that participate in such activities as DNA binding, protein–protein interaction, and transcriptional activation or repression. To fully comprehend the behavior of a given transcription factor, however, these domains must be analyzed in the context of the entire protein, and in certain cases the context of a multiprotein complex. Furthermore, it must be appreciated that transcription factors function in the nucleus, where they must contend with a variety of factors, including the nuclear architecture, chromatin domains, chromosome territories, and cell-cycle-associated processes. Recent examinations of transcription factors in the nucleus have clarified the behavior of these proteins in vivo and have increased our understanding of how gene expression is regulated in eukaryotes. Here, we review the current knowledge regarding sequence-specific transcription factor compartmentalization within the nucleus and discuss its impact on the regulation of such processes as activation or repression of gene expression and interaction with coregulatory factors.Key words: transcription, subnuclear localization, chromatin, gene expression, nuclear architecture.

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Micro/nano-textured hierarchical titanium topography promotes exosome biogenesis and secretion to improve osseointegration

Journal of Nanobiotechnology ◽

10.1186/s12951-021-00826-3 ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Zhengchuan Zhang ◽

Ruogu Xu ◽

Yang Yang ◽

Chaoan Liang ◽

Xiaolin Yu ◽

...

Keyword(s):

Gene Expression ◽

Titanium Surface ◽

Titanium Implants ◽

Extracellular Secretion ◽

Exosome Biogenesis ◽

Marrow Mesenchymal Stem Cells ◽

Proliferation In Vitro ◽

Extracellular Environment

Abstract Background Micro/nano-textured hierarchical titanium topography is more bioactive and biomimetic than smooth, micro-textured or nano-textured titanium topographies. Bone marrow mesenchymal stem cells (BMSCs) and exosomes derived from BMSCs play important roles in the osseointegration of titanium implants, but the effects and mechanisms of titanium topography on BMSCs-derived exosome secretion are still unclear. This study determined whether the secretion behavior of exosomes derived from BMSCs is differently affected by different titanium topographies both in vitro and in vivo. Results We found that both micro/nanonet-textured hierarchical titanium topography and micro/nanotube-textured hierarchical titanium topography showed favorable roughness and hydrophilicity. These two micro/nano-textured hierarchical titanium topographies enhanced the spreading areas of BMSCs on the titanium surface with stronger promotion of BMSCs proliferation in vitro. Compared to micro-textured titanium topography, micro/nano-textured hierarchical titanium topography significantly enhanced osseointegration in vivo and promoted BMSCs to synthesize and transport exosomes and then release these exosomes into the extracellular environment both in vitro and in vivo. Moreover, micro/nanonet-textured hierarchical titanium topography promoted exosome secretion by upregulating RAB27B and SMPD3 gene expression and micro/nanotube-textured hierarchical titanium topography promoted exosome secretion due to the strongest enhancement in cell proliferation. Conclusions These findings provide evidence that micro/nano-textured hierarchical titanium topography promotes exosome biogenesis and extracellular secretion for enhanced osseointegration. Our findings also highlight that the optimized titanium topography can increase exosome secretion from BMSCs, which may promote osseointegration of titanium implants.

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Progression and Differentiation of Alveolar Rhabdomyosarcoma Is Regulated by PAX7 Transcription Factor—Significance of Tumor Subclones

Cells ◽

10.3390/cells10081870 ◽

2021 ◽

Vol 10 (8) ◽

pp. 1870

Author(s):

Klaudia Skrzypek ◽

Grażyna Adamek ◽

Marta Kot ◽

Bogna Badyra ◽

Marcin Majka

Keyword(s):

Transcription Factor ◽

Cell Lines ◽

Migration Activity ◽

Id Proteins ◽

Rh30 Cell ◽

Str Profile ◽

And Migration

Rhabdomyosarcoma (RMS), is the most frequent soft tissue tumor in children that originates from disturbances in differentiation process. Mechanisms leading to the development of RMS are still poorly understood. Therefore, by analysis of two RMS RH30 cell line subclones, one subclone PAX7 negative, while the second one PAX7 positive, and comparison with other RMS cell lines we aimed at identifying new mechanisms crucial for RMS progression. RH30 subclones were characterized by the same STR profile, but different morphology, rate of proliferation, migration activity and chemotactic abilities in vitro, as well as differences in tumor morphology and growth in vivo. Our analysis indicated a different level of expression of adhesion molecules (e.g., from VLA and ICAM families), myogenic microRNAs, such as miR-206 and transcription factors, such as MYOD, MYOG, SIX1, and ID. Silencing of PAX7 transcription factor with siRNA confirmed the crucial role of PAX7 transcription factor in proliferation, differentiation and migration of RMS cells. To conclude, our results suggest that tumor cell lines with the same STR profile can produce subclones that differ in many features and indicate crucial roles of PAX7 and ID proteins in the development of RMS.

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The use of siRNA as a pharmacological tool to assess a role for the transcription factor NF-IL6 in the brain under in vitro and in vivo conditions during LPS-induced inflammatory stimulation

Journal of Basic and Clinical Physiology and Pharmacology ◽

10.1515/jbcpp-2017-0017 ◽

2017 ◽

Vol 28 (6) ◽

Cited By ~ 2

Author(s):

Jelena Damm ◽

Joachim Roth ◽

Rüdiger Gerstberger ◽

Christoph Rummel

Keyword(s):

Transcription Factor ◽

Brain Cells ◽

Nuclear Factor ◽

Si Rna ◽

The Brain ◽

Deficient Mice ◽

Transcription Factor Nuclear Factor

AbstractBackground:Studies with NF-IL6-deficient mice indicate that this transcription factor plays a dual role during systemic inflammation with pro- and anti-inflammatory capacities. Here, we aimed to characterize the role of NF-IL6 specifically within the brain.Methods:In this study, we tested the capacity of short interfering (si) RNA to silence the inflammatory transcription factor nuclear factor-interleukin 6 (NF-IL6) in brain cells underResults:In cells of a mixed neuronal and glial primary culture from the ratConclusions:This approach was, thus, not suitable to characterize the role NF-IL6 in the brain

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HNRNPA2B1 promotes multiple myeloma progression by increasing AKT3 expression via m6A-dependent stabilization of ILF3 mRNA

Journal of Hematology & Oncology ◽

10.1186/s13045-021-01066-6 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Fengjie Jiang ◽

Xiaozhu Tang ◽

Chao Tang ◽

Zhen Hua ◽

Mengying Ke ◽

...

Keyword(s):

Multiple Myeloma ◽

Cell Proliferation ◽

Cellular Proliferation ◽

Aberrant Expression ◽

The Stability ◽

Induced Apoptosis ◽

Proliferation In Vitro

AbstractN6-methyladenosine (m6A) modification is the most prevalent modification in eukaryotic RNAs while accumulating studies suggest that m6A aberrant expression plays an important role in cancer. HNRNPA2B1 is a m6A reader which binds to nascent RNA and thus affects a perplexing array of RNA metabolism exquisitely. Despite unveiled facets that HNRNPA2B1 is deregulated in several tumors and facilitates tumor growth, a clear role of HNRNPA2B1 in multiple myeloma (MM) remains elusive. Herein, we analyzed the function and the regulatory mechanism of HNRNPA2B1 in MM. We found that HNRNPA2B1 was elevated in MM patients and negatively correlated with favorable prognosis. The depletion of HNRNPA2B1 in MM cells inhibited cell proliferation and induced apoptosis. On the contrary, the overexpression of HNRNPA2B1 promoted cell proliferation in vitro and in vivo. Mechanistic studies revealed that HNRNPA2B1 recognized the m6A sites of ILF3 and enhanced the stability of ILF3 mRNA transcripts, while AKT3 downregulation by siRNA abrogated the cellular proliferation induced by HNRNPA2B1 overexpression. Additionally, the expression of HNRNPA2B1, ILF3 and AKT3 was positively associated with each other in MM tissues tested by immunohistochemistry. In summary, our study highlights that HNRNPA2B1 potentially acts as a therapeutic target of MM through regulating AKT3 expression mediated by ILF3-dependent pattern.

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Lineage-specific requirements of β-catenin in neural crest development

The Journal of Cell Biology ◽

10.1083/jcb.200209039 ◽

2002 ◽

Vol 159 (5) ◽

pp. 867-880 ◽

Cited By ~ 207

Author(s):

Lisette Hari ◽

Véronique Brault ◽

Maurice Kléber ◽

Hye-Youn Lee ◽

Fabian Ille ◽

...

Keyword(s):

Transcription Factor ◽

Neural Crest ◽

Neural Crest Cells ◽

Neural Crest Stem Cells ◽

Downstream Signaling ◽

Neural Crest Development ◽

Sensory Neurogenesis

β-Catenin plays a pivotal role in cadherin-mediated cell adhesion. Moreover, it is a downstream signaling component of Wnt that controls multiple developmental processes such as cell proliferation, apoptosis, and fate decisions. To study the role of β-catenin in neural crest development, we used the Cre/loxP system to ablate β-catenin specifically in neural crest stem cells. Although several neural crest–derived structures develop normally, mutant animals lack melanocytes and dorsal root ganglia (DRG). In vivo and in vitro analyses revealed that mutant neural crest cells emigrate but fail to generate an early wave of sensory neurogenesis that is normally marked by the transcription factor neurogenin (ngn) 2. This indicates a role of β-catenin in premigratory or early migratory neural crest and points to heterogeneity of neural crest cells at the earliest stages of crest development. In addition, migratory neural crest cells lateral to the neural tube do not aggregate to form DRG and are unable to produce a later wave of sensory neurogenesis usually marked by the transcription factor ngn1. We propose that the requirement of β-catenin for the specification of melanocytes and sensory neuronal lineages reflects roles of β-catenin both in Wnt signaling and in mediating cell–cell interactions.

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