scholarly journals Nanog, in Cooperation with AP1, Increases the Expression of E6/E7 Oncogenes from HPV Types 16/18

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1482
Author(s):  
Yakelin Díaz-Tejeda ◽  
Miriam C. Guido-Jiménez ◽  
Helga López-Carbajal ◽  
Alfredo Amador-Molina ◽  
Rocío Méndez-Martínez ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Cancer Progression ◽  
Transcriptional Activation ◽  
Binding Sites ◽  
Cancer Development ◽  
Long Control Region ◽  
In Vitro Mutagenesis ◽  
Mrna Levels ◽  
Hpv Types

Persistent infections with some types of human papillomavirus (HPV) constitute the major etiological factor for cervical cancer development. Nanog, a stem cell transcription factor has been shown to increase during cancer progression. We wanted to determine whether Nanog could modulate transcription of E6 and E7 oncogenes. We used luciferase reporters under the regulation of the long control region (LCR) of HPV types 16 and 18 (HPV16/18) and performed RT-qPCR. We found that Nanog increases activity of both viral regulatory regions and elevates endogenous E6/E7 mRNA levels in cervical cancer-derived cells. We demonstrated by in vitro mutagenesis that changes at Nanog-binding sites found in the HPV18 LCR significantly inhibit transcriptional activation. Chromatin immunoprecipitation (ChIP) assays showed that Nanog binds in vivo to the HPV18 LCR, and its overexpression increases its binding as well as that of c-Jun. Surprisingly, we observed that mutation of AP1-binding sites also affect Nanog’s ability to activate transcription, suggesting cooperation between the two factors. We searched for putative Nanog-binding sites in the LCR of several HPVs and surprisingly found them only in those types associated with cancer development. Our study shows, for the first time, a role for Nanog in the regulation of E6/E7 transcription of HPV16/18.

scholarly journals UBE2C Drives Human Cervical Cancer Progression and Is Positively Modulated by mTOR

Biomolecules ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 37
Author(s):  
An-Jen Chiang ◽  
Chia-Jung Li ◽  
Kuan-Hao Tsui ◽  
Chung Chang ◽  
Yuan-chin Ivan Chang ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Cancer Progression ◽  
Cancer Staging ◽  
Cervical Squamous Cell Carcinoma ◽  
Cancer Cell Proliferation ◽  
Gynecological Malignancy ◽  
In Vivo Experiments ◽  
Ubiquitin Conjugating Enzyme

Cervical cancer is a common gynecological malignancy, accounting for 10% of all gynecological cancers. Recently, targeted therapy for cervical cancer has shown unprecedented advantages. Several studies have shown that ubiquitin conjugating enzyme E2 (UBE2C) is highly expressed in a series of tumors, and participates in the progression of these tumors. However, the possible impact of UBE2C on the progression of cervical squamous cell carcinoma (CESC) remains unclear. Here, we carried out tissue microarray analysis of paraffin-embedded tissues from 294 cervical cancer patients with FIGO/TNM cancer staging records. The results indicated that UBE2C was highly expressed in human CESC tissues and its expression was related to the clinical characteristics of CESC patients. Overexpression and knockdown of UBE2C enhanced and reduced cervical cancer cell proliferation, respectively, in vitro. Furthermore, in vivo experiments showed that UBE2C regulated the expression and activity of the mTOR/PI3K/AKT pathway. In summary, we confirmed that UBE2C is involved in the process of CESC and that UBE2C may represent a molecular target for CESC treatment.

scholarly journals YB-1 Is Altered in Pregnancy-Associated Disorders and Affects Trophoblast in Vitro Properties via Alternation of Multiple Molecular Traits

2021 ◽  
Vol 22 (13) ◽  
pp. 7226
Author(s):  
Violeta Stojanovska ◽  
Aneri Shah ◽  
Katja Woidacki ◽  
Florence Fischer ◽  
Mario Bauer ◽  
...  
Keyword(s):  
Cell Lines ◽  
Cancer Progression ◽  
Cell Function ◽  
Trophoblast Cell ◽  
Mrna Levels ◽  
Trophoblast Cells ◽  
Invasion And Migration ◽  
And Migration ◽  
Apoptosis And Inflammation

Cold shock Y-box binding protein-1 (YB-1) coordinates several molecular processes between the nucleus and the cytoplasm and plays a crucial role in cell function. Moreover, it is involved in cancer progression, invasion, and metastasis. As trophoblast cells share similar characteristics with cancer cells, we hypothesized that YB-1 might also be necessary for trophoblast functionality. In samples of patients with intrauterine growth restriction, YB-1 mRNA levels were decreased, while they were increased in preeclampsia and unchanged in spontaneous abortions when compared to normal pregnant controls. Studies with overexpression and downregulation of YB-1 were performed to assess the key trophoblast processes in two trophoblast cell lines HTR8/SVneo and JEG3. Overexpression of YB-1 or exposure of trophoblast cells to recombinant YB-1 caused enhanced proliferation, while knockdown of YB-1 lead to proliferative disadvantage in JEG3 or HTR8/SVneo cells. The invasion and migration properties were affected at different degrees among the trophoblast cell lines. Trophoblast expression of genes mediating migration, invasion, apoptosis, and inflammation was altered upon YB-1 downregulation. Moreover, IL-6 secretion was excessively increased in HTR8/SVneo. Ultimately, YB-1 directly binds to NF-κB enhancer mark in HTR8/SVneo cells. Our data show that YB-1 protein is important for trophoblast cell functioning and, when downregulated, leads to trophoblast disadvantage that at least in part is mediated by NF-κB.

scholarly journals NR5A2 transcriptional activation by BRD4 promotes pancreatic cancer progression by upregulating GDF15

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Feng Guo ◽  
Yingke Zhou ◽  
Hui Guo ◽  
Dianyun Ren ◽  
Xin Jin ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cancer Cells ◽  
Cancer Progression ◽  
Transcriptional Activation ◽  
Ductal Adenocarcinoma ◽  
Pancreatic Cancer Cells ◽  
Gene Sets ◽  
And Migration

AbstractNR5A2 is a transcription factor regulating the expression of various oncogenes. However, the role of NR5A2 and the specific regulatory mechanism of NR5A2 in pancreatic ductal adenocarcinoma (PDAC) are not thoroughly studied. In our study, Western blotting, real-time PCR, and immunohistochemistry were conducted to assess the expression levels of different molecules. Wound-healing, MTS, colony formation, and transwell assays were employed to evaluate the malignant potential of pancreatic cancer cells. We demonstrated that NR5A2 acted as a negative prognostic biomarker in PDAC. NR5A2 silencing inhibited the proliferation and migration abilities of pancreatic cancer cells in vitro and in vivo. While NR5A2 overexpression markedly promoted both events in vitro. We further identified that NR5A2 was transcriptionally upregulated by BRD4 in pancreatic cancer cells and this was confirmed by Chromatin immunoprecipitation (ChIP) and ChIP-qPCR. Besides, transcriptome RNA sequencing (RNA-Seq) was performed to explore the cancer-promoting effects of NR5A2, we found that GDF15 is a component of multiple down-regulated tumor-promoting gene sets after NR5A2 was silenced. Next, we showed that NR5A2 enhanced the malignancy of pancreatic cancer cells by inducing the transcription of GDF15. Collectively, our findings suggest that NR5A2 expression is induced by BRD4. In turn, NR5A2 activates the transcription of GDF15, promoting pancreatic cancer progression. Therefore, NR5A2 and GDF15 could be promising therapeutic targets in pancreatic cancer.

scholarly journals Multiple ASF/SF2 Sites in the Human Papillomavirus Type 16 (HPV-16) E4-Coding Region Promote Splicing to the Most Commonly Used 3′-Splice Site on the HPV-16 Genome

2010 ◽  
Vol 84 (16) ◽  
pp. 8219-8230 ◽  
Author(s):  
Monika Somberg ◽  
Stefan Schwartz
Keyword(s):  
Cervical Cancer ◽  
Human Papillomavirus ◽  
Splice Site ◽  
Binding Sites ◽  
Mrna Levels ◽  
Coding Region ◽  
Cervical Lesions ◽  
Hpv 16 ◽  
Human Papillomavirus Type 16 ◽  
E6 And E7

ABSTRACT Our results presented here demonstrate that the most abundant human papillomavirus type 16 (HPV-16) mRNAs expressing the viral oncogenes E6 and E7 are regulated by cellular ASF/SF2, itself defined as a proto-oncogene and overexpressed in cervical cancer cells. We show that the most frequently used 3′-splice site on the HPV-16 genome, site SA3358, which is used to produce primarily E4, E6, and E7 mRNAs, is regulated by ASF/SF2. Splice site SA3358 is immediately followed by 15 potential binding sites for the splicing factor ASF/SF2. Recombinant ASF/SF2 binds to the cluster of ASF/SF2 sites. Mutational inactivation of all 15 sites abolished splicing to SA3358 and redirected splicing to the downstream-located, late 3′-splice site SA5639. Overexpression of a mutant ASF/SF2 protein that lacks the RS domain, also totally inhibited the usage of SA3358 and redirected splicing to the late 3′-splice site SA5639. The 15 ASF/SF2 binding sites could be replaced by an ASF/SF2-dependent, HIV-1-derived splicing enhancer named GAR. This enhancer was also inhibited by the mutant ASF/SF2 protein that lacks the RS domain. Finally, silencer RNA (siRNA)-mediated knockdown of ASF/SF2 caused a reduction in spliced HPV-16 mRNA levels. Taken together, our results demonstrate that the major HPV-16 3′-splice site SA3358 is dependent on ASF/SF2. SA3358 is used by the most abundantly expressed HPV-16 mRNAs, including those encoding E6 and E7. High levels of ASF/SF2 may therefore be a requirement for progression to cervical cancer. This is supported by our earlier findings that ASF/SF2 is overexpressed in high-grade cervical lesions and cervical cancer.

Interspersion of an unusual GCN4 activation site with a complex transcriptional repression site in Ty2 elements of Saccharomyces cerevisiae

1993 ◽  
Vol 13 (4) ◽  
pp. 2091-2103
Author(s):  
S Türkel ◽  
P J Farabaugh
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transcriptional Activation ◽  
Binding Sites ◽  
Transcriptional Repression ◽  
Physiological Control ◽  
Reading Frame ◽  
Negative Region ◽  
Activation Site

Transcription of the Ty2-917 retrotransposon of Saccharomyces cerevisiae is modulated by a complex set of positive and negative elements, including a negative region located within the first open reading frame, TYA2. The negative region includes three downstream repression sites (DRSI, DRSII, and DRSIII). In addition, the negative region includes at least two downstream activation sites (DASs). This paper concerns the characterization of DASI. A 36-bp DASI oligonucleotide acts as an autonomous transcriptional activation site and includes two sequence elements which are both required for activation. We show that these sites bind in vitro the transcriptional activation protein GCN4 and that their activity in vivo responds to the level of GCN4 in the cell. We have termed the two sites GCN4 binding sites (GBS1 and GBS2). GBS1 is a high-affinity GCN4 binding site (dissociation constant, approximately 25 nM at 30 degrees C), binding GCN4 with about the affinity of a consensus UASGCN4, this though GBS1 includes two differences from the right half of the palindromic consensus site. GBS2 is more diverged from the consensus and binds GCN4 with about 20-fold-lower affinity. Nucleotides 13 to 36 of DASI overlap DRSII. Since DRSII is a transcriptional repression site, we tested whether DASI includes repression elements. We identify two sites flanking GBS2, both of which repress transcription activated by the consensus GCN4-specific upstream activation site (UASGCN4). One of these is repeated in the 12 bp immediately adjacent to DASI. Thus, in a 48-bp region of Ty2-917 are interspersed two positive and three negative transcriptional regulators. The net effect of the region must depend on the interaction of the proteins bound at these sites, which may include their competing for binding sites, and on the physiological control of the activity of these proteins.

scholarly journals HPV-18 E6 Oncoprotein and Its Spliced Isoform E6*I Regulate the Wnt/β-Catenin Cell Signaling Pathway through the TCF-4 Transcriptional Factor

2018 ◽  
Vol 19 (10) ◽  
pp. 3153 ◽  
Author(s):  
J. Muñoz-Bello ◽  
Leslie Olmedo-Nieva ◽  
Leonardo Castro-Muñoz ◽  
Joaquín Manzo-Merino ◽  
Adriana Contreras-Paredes ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Cell Proliferation ◽  
Signaling Pathway ◽  
Transcriptional Activation ◽  
Target Genes ◽  
Promote Cell Proliferation ◽  
E6 And E7 ◽  
Hpv 18

The Wnt/β-catenin signaling pathway regulates cell proliferation and differentiation and its aberrant activation in cervical cancer has been described. Persistent infection with high risk human papillomavirus (HR-HPV) is the most important factor for the development of this neoplasia, since E6 and E7 viral oncoproteins alter cellular processes, promoting cervical cancer development. A role of HPV-16 E6 in Wnt/β-catenin signaling has been proposed, although the participation of HPV-18 E6 has not been previously studied. The aim of this work was to investigate the participation of HPV-18 E6 and E6*I, in the regulation of the Wnt/β-catenin signaling pathway. Here, we show that E6 proteins up-regulate TCF-4 transcriptional activity and promote overexpression of Wnt target genes. In addition, it was demonstrated that E6 and E6*I bind to the TCF-4 (T cell factor 4) and β-catenin, impacting TCF-4 stabilization. We found that both E6 and E6*I proteins interact with the promoter of Sp5, in vitro and in vivo. Moreover, although differences in TCF-4 transcriptional activation were found among E6 intratype variants, no changes were observed in the levels of regulated genes. Furthermore, our data support that E6 proteins cooperate with β-catenin to promote cell proliferation.

RAP1 is required for BAS1/BAS2- and GCN4-dependent transcription of the yeast HIS4 gene

1991 ◽  
Vol 11 (7) ◽  
pp. 3642-3651 ◽  
Author(s):  
C Devlin ◽  
K Tice-Baldwin ◽  
D Shore ◽  
K T Arndt
Keyword(s):  
Steady State ◽  
Binding Site ◽  
Binding Sites ◽  
Binding Activity ◽  
Micrococcal Nuclease ◽  
Mrna Levels ◽  
High Affinity ◽  
Steady State Levels

The major in vitro binding activity to the Saccharomyces cerevisiae HIS4 promoter is due to the RAP1 protein. In the absence of GCN4, BAS1, and BAS2, the RAP1 protein binds to the HIS4 promoter in vivo but cannot efficiently stimulate HIS4 transcription. RAP1, which binds adjacently to BAS2 on the HIS4 promoter, is required for BAS1/BAS2-dependent activation of HIS4 basal-level transcription. In addition, the RAP1-binding site overlaps with the single high-affinity HIS4 GCN4-binding site. Even though RAP1 and GCN4 bind competitively in vitro, RAP1 is required in vivo for (i) the normal steady-state levels of GCN4-dependent HIS4 transcription under nonstarvation conditions and (ii) the rapid increase in GCN4-dependent steady-state HIS4 mRNA levels following amino acid starvation. The presence of the RAP1-binding site in the HIS4 promoter causes a dramatic increase in the micrococcal nuclease sensitivity of two adjacent regions within HIS4 chromatin: one region contains the high-affinity GCN4-binding site, and the other region contains the BAS1- and BAS2-binding sites. These results suggest that RAP1 functions at HIS4 by increasing the accessibility of GCN4, BAS1, and BAS2 to their respective binding sites when these sites are present within chromatin.

scholarly journals RANK-RANKL Signaling in Cancer of the Uterine Cervix: A Review

2019 ◽  
Vol 20 (9) ◽  
pp. 2183 ◽  
Author(s):  
Peter A. van Dam ◽  
Yannick Verhoeven ◽  
Julie Jacobs ◽  
An Wouters ◽  
Wiebren Tjalma ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Tumor Necrosis Factor ◽  
Cancer Cells ◽  
Cancer Progression ◽  
Uterine Cervix ◽  
Tumor Necrosis ◽  
Immune Therapy ◽  
Mrna Levels ◽  
Cervical Cancer Cells ◽  
Necrosis Factor

RANK ligand (RANKL) is a member of the tumor necrosis factor alpha superfamily of cytokines. It is the only known ligand binding to a membrane receptor named receptor activator of nuclear factor-kappa B (RANK), thereby triggering recruitment of tumor necrosis factor (TNF) receptor associated factor (TRAF) adaptor proteins and activation of downstream pathways. RANK/RANKL signaling is controlled by a decoy receptor called osteoprotegerin (OPG), but also has additional more complex levels of regulation. The existing literature on RANK/RANKL signaling in cervical cancer was reviewed, particularly focusing on the effects on the microenvironment. RANKL and RANK are frequently co-expressed in cervical cancer cells lines and in carcinoma of the uterine cervix. RANKL and OPG expression strongly increases during cervical cancer progression. RANKL is directly secreted by cervical cancer cells, which may be a mechanism they use to create an immune suppressive environment. RANKL induces expression of multiple activating cytokines by dendritic cells. High RANK mRNA levels and high immunohistochemical OPG expression are significantly correlated with high clinical stage, tumor grade, presence of lymph node metastases, and poor overall survival. Inhibition of RANKL signaling has a direct effect on tumor cell proliferation and behavior, but also alters the microenvironment. Abundant circumstantial evidence suggests that RANKL inhibition may (partially) reverse an immunosuppressive status. The use of denosumab, a monoclonal antibody directed to RANKL, as an immunomodulatory strategy is an attractive concept which should be further explored in combination with immune therapy in patients with cervical cancer.

Phylogeny and Polymorphism in the Long Control Region, E6, and L1 of Human Papillomavirus Types 53, 56, and 66 in Central Brazil

2011 ◽  
Vol 21 (2) ◽  
pp. 222-229 ◽  
Author(s):  
Patrícia Soares Wyant ◽  
Daniela Marreco Cerqueira ◽  
Daniella Sousa Moraes ◽  
José Paulo Gagliardi Leite ◽  
Cláudia Renata Fernandes Martins ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Amino Acid ◽  
Genetic Variability ◽  
Binding Sites ◽  
Long Control Region ◽  
Amino Acid Substitutions ◽  
Nucleotide Substitutions ◽  
Central Brazil ◽  
Hpv Types ◽  
Genomic Regions

Introduction:Several studies related that different human papillomavirus (HPV) types and intratype variants can present different oncogenic potential. In opposite to HPVs 16 and 18 variants, information about variants of other carcinogenic HPV types is still scarce. The aim of this study was to investigate the genetic variability of HPVs 53, 56, and 66 from Central Brazil isolates.Methods:The long control region (LCR), E6, and L1 genomic regions were amplified and sequenced. We evaluate for nucleotide variations in relation to the reference sequence of each HPV type and also the conservation of physicochemical properties of the deduced amino acid substitutions. In silico analysis was performed to locate binding sites for transcriptional factors within the LCR. Moreover, we performed a phylogenetic analysis with the Central Brazilian and worldwide sequences available at genomic databases.Results:Gathering LCR, E6, and L1 genomic regions, the highest genetic variability was found among HPV-53 isolates with 52 nucleotide variations, followed by HPVs 56 and 66 with 24 and 16 nucleotide substitutions, respectively. The genetic analysis revealed 11 new molecular variants of all HPV types analyzed, totalizing 31 new nucleotide and 3 new amino acid variations. Eight nonconservative amino acid substitutions were detected, which may indicate a biological and pathogenic diversity among HPV types. Furthermore, 8 nucleotide substitutions were localized at putative binding sites for transcription factors in the LCR with a potential implication on viral oncogene expression. The HPVs 53, 56, and 66 phylogenetic analysis confirmed a dichotomic division only described to HPV subtypes and different from the patterns described for HPVs 16 and 18 variants.Conclusions:The high genetic variability observed emphasizes the importance of investigating polymorphisms in types other than HPVs 16 or 18 to better understand the molecular genomic profile of viral infection by different HPV types.

scholarly journals Spatiotemporal Cascade of Transcription Factor Binding Required for Promoter Activation

2014 ◽  
Vol 35 (4) ◽  
pp. 688-698 ◽  
Author(s):  
Robert M. Yarrington ◽  
Jared S. Rudd ◽  
David J. Stillman
Keyword(s):  
Transcription Factor ◽  
Transcriptional Activation ◽  
Binding Sites ◽  
Gene Activation ◽  
Regulatory Sequence ◽  
Factor Binding ◽  
Multiple Binding Sites ◽  
Dependent Cell ◽  
The Right

Promoters often contain multiple binding sites for a single factor. The yeastHOgene contains nine highly conserved binding sites for the SCB (Swi4/6-dependent cell cycle box) binding factor (SBF) complex (composed of Swi4 and Swi6) in the 700-bp upstream regulatory sequence 2 (URS2) promoter region. Here, we show that the distal and proximal SBF sites in URS2 function differently. Chromatin immunoprecipitation (ChIP) experiments show that SBF binds preferentially to the left side of URS2 (URS2-L), despite equivalent binding to the left-half and right-half SBF sitesin vitro. SBF binding at URS2-L sites depends on prior chromatin remodeling events at the upstream URS1 region. These signals from URS1 influence chromatin changes at URS2 but only at sites within a defined distance. SBF bound at URS2-L, however, is unable to activate transcription but instead facilitates SBF binding to sites in the right half (URS2-R), which are required for transcriptional activation. Factor binding atHO, therefore, follows a temporal cascade, with SBF bound at URS2-L serving to relay a signal from URS1 to the SBF sites in URS2-R that ultimately activate gene expression. Taken together, we describe a novel property of a transcription factor that can have two distinct roles in gene activation, depending on its location within a promoter.

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