scholarly journals Identification of cis-Acting Deoxyribonucleic Acid Elements That Mediate Gonadotropin-Releasing Hormone Stimulation of the Rat Luteinizing Hormone β-Subunit Gene*

Endocrinology ◽  
1998 ◽  
Vol 139 (5) ◽  
pp. 2443-2451 ◽  
Author(s):  
Ursula B. Kaiser ◽  
Elena Sabbagh ◽  
Brian D. Saunders ◽  
William W. Chin
Keyword(s):  
Cell Lines ◽  
Dna Sequences ◽  
Critical Role ◽  
Gene Promoter ◽  
Protein S ◽  
Luciferase Reporter ◽  
Pituitary Cells ◽  
Subunit Gene ◽  
Cis Acting ◽  
Rat Pituitary

Abstract GnRH plays a critical role in reproductive development and function by regulating the biosynthesis and secretion of the pituitary gonadotropins, LH and FSH. Although it is known that GnRH induces gonadotropin subunit gene transcription, the mechanism by which this occurs has not been elucidated. Studies have been hindered by the lack of available cell lines that express the LH and FSH subunit genes and respond to GnRH. We have transfected the rat pituitary GH3 cell line with the rat GnRH receptor complementary DNA. These cells, when cotransfected with regulatory regions of the LH or FSH subunit genes fused to a luciferase reporter gene, respond to GnRH with an increase in promoter activity comparable to that seen in primary rat pituitary cells. In this study, we have used this cell model to identify cis-acting elements of the LHβ gene that mediate stimulation by GnRH. Analysis of a series of 5′-deletion and internal deletion constructs has revealed two regions of the rat LHβ gene promoter involved in mediating the response to GnRH, region A (−490/−352) and region B (−207/−82). Fusion of region A upstream of a heterologous minimal promoter linked to the luciferase gene conferred GnRH responsiveness to the promoter, whereas region B did not. However, the presence of both regions A and B conferred a greater GnRH response than region A alone. Electrophoretic mobility shift assay revealed the presence of a protein(s) binding to region A using GH3 as well as αT3–1 nuclear extracts. Thus, region A (−490/−352) confers GnRH responsiveness to the LHβ subunit gene and binds to a protein(s) present in pituitary cell lines. DNA sequences in region B (−207/−82) also contribute to GnRH responsiveness. The identification of putative GnRH response elements in the rat LHβ gene promoter will aid in elucidation of the mechanisms of regulation of gene expression by GnRH.

scholarly journals Real-time imaging of gene promoter activity using an adenoviral reporter construct demonstrates transcriptional dynamics in normal anterior pituitary cells

2003 ◽  
Vol 178 (1) ◽  
pp. 61-69 ◽  
Author(s):  
JA Stirland ◽  
ZC Seymour ◽  
S Windeatt ◽  
AJ Norris ◽  
P Stanley ◽  
...  
Keyword(s):  
Gene Expression ◽  
Real Time ◽  
Cell Lines ◽  
Promoter Activity ◽  
Expression Patterns ◽  
Gene Promoter ◽  
Luciferase Reporter ◽  
Pituitary Cells ◽  
Clonal Cell ◽  
Clonal Cell Lines

Although analysis of luciferase activity using luminescence imaging has provided new insights into the dynamic regulation of gene expression in living tIssues, studies in vitro have relied on stably transfected clonal cell lines, limiting the choice of cell type and species, or DNA microinjection, which is arduous and highly selective. We report here the first use of a recombinant adenovirus in which the firefly luciferase reporter gene was regulated by the prolactin gene promoter, to study temporal dynamics of promoter activity. This vector was used to infect the pituitary GH3 cell line, and also primary cultures of Syrian hamster pituitary cells. We show that adenovirally transduced cells retained normal regulation of the promoter-reporter transgene by appropriate signals. Furthermore, microscopic imaging studies indicated that both clonal and primary pituitary cells were transduced efficiently, giving readily detectable luminescence signals in real-time over long periods. Finally, analysis of single-cell expression patterns indicated that prolactin promoter activity was highly dynamic with pulses in gene expression, revealing that the transcriptional instability seen in clonal cells is a feature of normal pituitary cells. Adenoviral vectors offer a valuable tool for studies of gene regulation where conventional transgenesis and clonal cell lines are not available.

scholarly journals Long non-coding RNA ARHGAP5-AS1 inhibits migration of breast cancer cell via stabilizing SMAD7 protein

2021 ◽  
Author(s):  
Chen-Long Wang ◽  
Jing-Chi Li ◽  
Ci-Xiang Zhou ◽  
Cheng-Ning Ma ◽  
Di-Fei Wang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Migration ◽  
Cell Lines ◽  
Cancer Cell ◽  
Breast Cancer Cell ◽  
Rho Gtpase ◽  
Critical Role ◽  
Luciferase Reporter ◽  
Breast Cancer Cell Lines ◽  
Smad7 Protein

Abstract Purpose Tumor metastasis is the main cause of death from breast cancer patients and cell migration plays a critical role in cancer metastasis. Recent studies have shown long non-coding RNAs (lncRNAs) play an essential role in the initiation and progression of cancer. In the present study, the role of an LncRNA, Rho GTPase Activating Protein 5- Antisense 1 (ARHGAP5-AS1) in breast cancer was investigated. Methods RNA sequencing was performed to find out dysregulated LncRNAs in MDA-MB-231-LM2 cells. Transwell migration assays and F-actin staining were utilized to estimate cell migration ability. RNA pulldown assays and RNA immunoprecipitation were used to prove the interaction between ARHGAP5-AS1 and SMAD7. Western blot and immunofluorescence imaging were used to examine the protein levels. Dual luciferase reporter assays were performed to evaluate the activation of TGF-β signaling. Results We analyzed the RNA-seq data of MDA-MB-231 and its highly metastatic derivative MDA-MB-231-LM2 cell lines (referred to as LM2) and identified a novel lncRNA (NR_027263) named as ARHGAP5-AS1, which expression was significantly downregulated in LM2 cells. Further functional investigation showed ARHGAP5-AS1 could inhibit cell migration via suppression of stress fibers in breast cancer cell lines. Afterwards, SMAD7 was further identified to interact with ARHGAP5-AS1 by its PY motif and thus its ubiquitination and degradation was blocked due to reduced interaction with E3 ligase SMURF1 and SMURF2. Moreover, ARHGAP5-AS1 could inhibit TGF-β signaling pathway due to its inhibitory role on SMAD7. Conclusion ARHGAP5-AS1 inhibits breast cancer cell migration via stabilization of SMAD7 protein and could serve as a novel biomarker and a potential target for breast cancer in the future.

Expression of the K-fgf proto-oncogene is controlled by 3' regulatory elements which are specific for embryonal carcinoma cells

1990 ◽  
Vol 10 (6) ◽  
pp. 2475-2484
Author(s):  
A M Curatola ◽  
C Basilico
Keyword(s):  
Dna Sequences ◽  
Embryonal Carcinoma ◽  
Protein S ◽  
Cell Types ◽  
Regulatory Elements ◽  
Developmentally Regulated ◽  
Cis Acting ◽  
Dna Elements ◽  
Ec Cells ◽  
Cat Expression

Expression of the K-fgf/hst proto-oncogene appears to be restricted to cells in the early stages of development, such as embryonal carcinoma (EC) cells. When EC cells are induced to differentiate, K-fgf expression is drastically repressed. To identify cis-acting DNA elements responsible for this type of regulation, we constructed a plasmid in which cat gene expression was driven by about 1 kilobase of upstream K-fgf human DNA sequences, including the putative promoter, and transfected it into undifferentiated F9 EC cells or HeLa cells as prototypes of cells which express or do not express, respectively, the K-fgf proto-oncogene. This plasmid was essentially inactive in both cell types, and the addition of more than 8 kilobases of DNA sequences upstream of the K-fgf promoter did not lead to any increase in chloramphenicol acetyltransferase (CAT) expression. On the other hand, when we inserted in this plasmid DNA sequences which are 3' of the human K-fgf coding sequences, we could detect a significant stimulation of CAT activity. Analysis of these sequences led to the identification of enhancerlike DNA elements which are part of the 3' noncoding region of K-fgf exon 3 and promote CAT expression only in undifferentiated mouse F9 or human NT2/D1 EC cells, but not in HeLa, 3T3, or differentiated F9 cells, therefore mimicking the physiological expression of the K-fgf proto-oncogene. Similar elements are also present in the 3' region of the murine K-fgf proto-oncogene, in a region showing high homology to the human K-fgf sequences. These regulatory elements can promote CAT expression from heterologous promoters in an EC-specific manner, suggesting that they interact with a specific cellular transacting protein(s) whose expression is developmentally regulated.

A 3-Bp Deletion Between Transcription Factor Binding Motifs In the HBS1L-MYB Intergenic Region on Chromosome 6q23 Is Associated with HbF Expression

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1013-1013
Author(s):  
John J. Farrell ◽  
Richard M. Sherva ◽  
Zhi-yi Chen ◽  
Luo Hong-yuan ◽  
Banjamin F. Chu ◽  
...  
Keyword(s):  
Hong Kong ◽  
Transcription Factors ◽  
Dna Sequences ◽  
Globin Gene ◽  
Gene Promoter ◽  
Proximal Promoter ◽  
Luciferase Reporter ◽  
Deletion Polymorphism ◽  
Functional Motif ◽  
A Genome

Abstract Abstract 1013 More than 3% of Chinese in Hong Kong are heterozygous carriers of β-thalassemia. Homozygotes or compound heterozygotes for β-thalassemia are usually severely ill and require monthly transfusions. Increased production of fetal hemoglobin (HbF) can modulate the disease severity by compensating for the shortfall of HbA caused by the β-thalassemia mutations. HbF level in adults varies and is regulated as a multigenic trait. Three major HbF quantitative trait loci (QTL) have been identified: the C/T SNP also known as the Xmn I site at the Gγ-globin gene promoter, the BCL11A polymorphism on chromosome 2p16, and the HBS1L-MYB intergenic polymorphism (HMIP) on chromosome 6q23. The functional motif for each of these 3 QTLs responsible for their effects upon HbF is not known. We undertook a genome-wide association study (GWAS), using Illumina Human 610-Quad BeadChip array, on 619 Chinese β-thalassemia heterozygotes from Hong Kong. In this population, the variance in HbF due to HMIP is 13.5%, significantly higher than that due to BCL11A polymorphism (6.4%). We used 1,000 Genomes Project data, SNP imputation, comparisons of association results across populations, predicted binding of transcription factors, and phylogenetic conservation to identify the functional variant in HMIP. Based on these lines of evidence, a hitherto unreported association between HbF expression and a 3-bp deletion on chromosome 6q23 was found. In 335 Chinese β-thalassemia heterozygotes, the 3-bp deletion polymorphism is in complete linkage disequilibrium with rs9399137, the SNP found in multiple GWAS to be most significantly associated with HbF (P=1.4E-24 in the Chinese cohort GWAS). Flanking this deletion are conserved binding sites for TAL1/SCL1, E47, GATA, and RUNX1/AML1, which are essential erythropoiesis-related transcription factors. The 3-bp deletion changes the normal DNA binding configuration of these transcription factors and spatial configuration for DNA-protein binding and/or protein-protein interactions. Furthermore, this 3-bp deletion polymorphism resides within a likely erythroid distal regulatory region manifested by DNase I hypersensitivity and GATA-1 binding (Wahlberg et al, Blood 114:1254, 2009). We hypothesized that a 61-bp fragment of DNA that encompasses the site of the 3-bp deletion polymorphism might have enhancer-like activity. When ligated to the Gγ-globin gene 1.4 kb proximal promoter linked to a luciferase reporter gene, the 61-bp fragment of DNA enhances the Gγ-globin gene promoter activity by more than 3-fold after transient transfection into K562 cells. A 58-bp fragment of DNA that includes the 3-bp deletion has 60% more enhancer-like activity than the 61-bp fragment without the deletion. These findings suggest that this 3-bp deletion polymorphism is most likely the functional motif accounting for HMIP modulation of HbF. Further studies are needed to identify target genes for this enhancer-like activity mediated by the DNA sequences encompassing the 3-bp deletion polymorphism in HMIP. These studies also suggest that this experimental approach could be used to identify functional motifs in other genotype-phenotype association studies. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Functional analysis of haplotypes and promoter activity at the 5' region of the DRD2 gene and associations with schizophrenia.

2020 ◽  
Author(s):  
Xicen Zhang ◽  
Mei Ding ◽  
Yi Liu ◽  
Yongping Liu ◽  
Jiaxin Xing ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Lines ◽  
Promoter Region ◽  
Regulatory Region ◽  
Gene Promoter ◽  
Luciferase Reporter ◽  
Drd2 Gene ◽  
Functional Regions

Abstract Background: In previous studies, we researched the association of the DRD2 gene promoter region SNP loci rs7116768, rs1047479195, rs1799732, rs1799978 and schizophrenia using Sanger sequencing. rs7116768 and rs1799978 were found to be slightly associated with schizophrenia. This study investigated the effects of haplotypes consisted of the four SNPs on protein expression level in vitro and identified the functional sequence in the 5’ regulatory region of DRD2 gene which has a potential link with schizophrenia.Methods: Recombinant plasmids with haplotypes, SNPs and 13 recombinant vectors containing deletion fragments from the DRD2 gene 5' regulatory region were transfected into HEK293 and SK-N-SH cell lines. Relative luciferase activity of the haplotypes, SNPs and different sequences was compared using a dual luciferase reporter assay system.Results: Haplotype H4(G-C-InsC-G) could significantly increase the gene expression in SK-N-SH cell lines. Allele C of rs7116768, allele A of rs1047479195 and allele del C of rs1799732 could up-regulate the gene expression. There were 5~7 functional regions in the promoter region of DRD2 gene that could affect the level of gene expression.Conclusion: We cannot rule out the possibility that different haplotypes may influence DRD2 gene expression in vivo. We observed that allele C of rs7116768, allele A of rs1047479195 and allele del C of rs1799732 could up-regulate gene expression. The truncation results confirmed the existence of functional regions in the promoter region of DRD2 gene that could affect the level of gene expression.

scholarly journals RDNA-14. RADIATION-INDUCED miR-4516 CONTRIBUTES TO RADIO-RESISTANCE AND PROMOTES AGGRESSIVE PHENOTYPE IN GLIOBLASTOMA

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi209-vi210
Author(s):  
Ebin Sebastian ◽  
Tiantian Cui ◽  
Erica Hlavin Bell ◽  
Joseph McElroy ◽  
Benjamin Johnson ◽  
...  
Keyword(s):  
Brain Tumor ◽  
Cell Viability ◽  
Cell Lines ◽  
Poor Prognosis ◽  
Radiation Treatment ◽  
Critical Role ◽  
Luciferase Reporter ◽  
Glioblastoma Cell ◽  
Clonogenic Assays ◽  
Glioblastoma Cell Lines

Abstract BACKGROUND Glioblastoma is the most aggressive brain tumor with poor prognosis despite the best available treatment. MicroRNAs (miRNAs) are emerging as promising, novel prognostic biomarkers and therapeutic targets in glioblastoma. In a previous study, we demonstrated that miR-4516 predicts poor prognosis and functions as an oncogene in glioblastoma. Aim of the current study is to examine the role miR-4516 in radiation resistance and identify downstream targets contributing to this phenotype METHODS Radiosensitization was evaluated by cell viability and clonogenic assays. Cell apoptosis was evaluated using flow cytometry and immunoblotting. Potential targets of miR-4516 were identified using bioinformatic analysis (Targetscan and miRDB) and confirmed by luciferase reporter assays. Results were validated using immunoblotting. miR-4516 expression in glioblastoma cell lines after radiation treatment was quantified by qRT-PCR. RESULTS Expression of miR-4516 was increased up to 15 fold following radiation treatment, peaking at around 15min-60 min in primary and established glioblastoma cell lines including GBM 08-387, GBM 30 and U87-MG. Furthermore, inhibition of miR-4516 sensitized GBM 08-387, GBM30 and U87-MG cells to radiation in comparison to control groups as determined by cell viability and clonogenic assays. Further, miR-4516 inhibition induced apoptosis in these cell lines following radiation treatment. While conducting mechanistic studies, we found that the tumor-promoting function of miR-4516 was, in part, mediated by inhibition of p21 and PTPN14, two direct targets of miR-4516 CONCLUSION Our data suggest that radiation induces the expression of miR-4516 in glioblastoma cell lines. This miRNA plays a critical role in radio-resistance and promotes aggressive phenotypes in glioblastoma and therefore, functional analyses of its target pathways may uncover novel therapeutically vulnerable target(s) in glioblastoma. FUNDING: R01CA108633, R01CA169368, RC2CA148190, U10CA180850-01(NCI), Brain Tumor Funders Collaborative Grant, and OSU-CCC (all to AC). The Ton and Patricia Bohnenn Fund for Neuro_Oncology Research (to PR).

DNA sequences required for expression of the LHβ promoter in primary cultures of rat pituitary cells

1990 ◽  
Vol 74 (2) ◽  
pp. 101-107 ◽  
Author(s):  
Kyoon E. Kim ◽  
Kathleen H. Day ◽  
Paul Howard ◽  
Stephen R.J. Salton ◽  
James L. Roberts ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Primary Cultures ◽  
Pituitary Cells ◽  
Rat Pituitary ◽  
Rat Pituitary Cells

scholarly journals Expression of the K-fgf proto-oncogene is controlled by 3' regulatory elements which are specific for embryonal carcinoma cells.

1990 ◽  
Vol 10 (6) ◽  
pp. 2475-2484 ◽  
Author(s):  
A M Curatola ◽  
C Basilico
Keyword(s):  
Dna Sequences ◽  
Embryonal Carcinoma ◽  
Protein S ◽  
Cell Types ◽  
Regulatory Elements ◽  
Developmentally Regulated ◽  
Cis Acting ◽  
Dna Elements ◽  
Ec Cells ◽  
Cat Expression

Expression of the K-fgf/hst proto-oncogene appears to be restricted to cells in the early stages of development, such as embryonal carcinoma (EC) cells. When EC cells are induced to differentiate, K-fgf expression is drastically repressed. To identify cis-acting DNA elements responsible for this type of regulation, we constructed a plasmid in which cat gene expression was driven by about 1 kilobase of upstream K-fgf human DNA sequences, including the putative promoter, and transfected it into undifferentiated F9 EC cells or HeLa cells as prototypes of cells which express or do not express, respectively, the K-fgf proto-oncogene. This plasmid was essentially inactive in both cell types, and the addition of more than 8 kilobases of DNA sequences upstream of the K-fgf promoter did not lead to any increase in chloramphenicol acetyltransferase (CAT) expression. On the other hand, when we inserted in this plasmid DNA sequences which are 3' of the human K-fgf coding sequences, we could detect a significant stimulation of CAT activity. Analysis of these sequences led to the identification of enhancerlike DNA elements which are part of the 3' noncoding region of K-fgf exon 3 and promote CAT expression only in undifferentiated mouse F9 or human NT2/D1 EC cells, but not in HeLa, 3T3, or differentiated F9 cells, therefore mimicking the physiological expression of the K-fgf proto-oncogene. Similar elements are also present in the 3' region of the murine K-fgf proto-oncogene, in a region showing high homology to the human K-fgf sequences. These regulatory elements can promote CAT expression from heterologous promoters in an EC-specific manner, suggesting that they interact with a specific cellular transacting protein(s) whose expression is developmentally regulated.

Sign in / Sign up

Export Citation Format

Share Document