Differential expression of the human gonadotropin alpha gene in ectopic and eutopic cells

We have analyzed the regulation of the alpha gonadotropin gene in eutopic placental cells and ectopic tumor cells by constructing a series of plasmid vectors containing alpha genomic 5' flanking DNA placed upstream of the gene encoding the bacterial enzyme chloramphenicol acetyltransferase (CAT). These plasmid DNAs were transfected into a eutopic (JAr) and an ectopic (HeLa) cell line. Both cell types expressed the CAT gene from plasmid constructs containing as much as 1,500 base pairs (bp) and as little as 140 bp of alpha 5' flanking DNA; JAr cells were considerably more efficient than HeLa cells. Ectopic and eutopic cells differed qualitatively in their expression from these alpha-CAT constructs when cells were treated with cAMP or butyrate. Butyrate induced alpha expression in HeLa cells but not in JAr cells, while cAMP induced expression in JAr cells. These results are consistent with and extend previous observations suggesting that there are cell-specific differences in the regulation of alpha gene expression in ectopic and eutopic cells. However, by using deletion constructs of the alpha-CAT gene, we found that the basal expression and cell-specific induction of the alpha gene in ectopic and eutopic cells were dependent on the same 140 bp of alpha 5' flanking DNA. These 140 bp were sequenced and found to contain a 9-bp stretch of DNA homologous with the consensus viral enhancer sequence. Such features of alpha expression common to both ectopic and eutopic cells may be involved in the coordinate expression of the alpha gene and the tumorigenic phenotype observed in each cell type.

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Independent regulation by sodium butyrate of gonadotropin alpha gene expression and cell cycle progression in HeLa cells

Molecular and Cellular Biology ◽

10.1128/mcb.4.5.829-839.1984 ◽

1984 ◽

Vol 4 (5) ◽

pp. 829-839

Author(s):

R B Darnell

Keyword(s):

Gene Expression ◽

Cell Cycle ◽

Sodium Butyrate ◽

Hela Cells ◽

Cell Cycle Progression ◽

Direct Action ◽

Cell Types ◽

Neoplastic Cell ◽

Alpha Subunit ◽

Alpha Gene

Sodium butyrate alters the growth and gene expression of a variety of differentiating and neoplastic cell types. For example, addition of 5 mM butyrate to HeLa cells is reported to both induce gonadotropin alpha subunit biosynthesis and block cell cycling in G1. We have studied these two actions of butyrate on HeLa cells and found that they are regulated in distinct ways. The induction of alpha subunit synthesis was due to an increase in the rate of transcription of the alpha gene. Using synchronized populations of HeLa cells, we determined that butyrate stimulates alpha transcription throughout the cell cycle. In contrast, treated cells arrest in G1 only if exposed to butyrate for a discrete period during the previous S phase. We conclude that butyrate inhibits DNA synthesis through a cell cycle-specific action that is independent from its direct action to stimulate transcription of the gonadotropin alpha gene.

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Analysis of Gene Expression in Normal and Cancer Cells Exposed toγ-Radiation

Journal of Biomedicine and Biotechnology ◽

10.1155/2008/541678 ◽

2008 ◽

Vol 2008 ◽

pp. 1-7 ◽

Cited By ~ 12

Author(s):

M. Ahmad Chaudhry

Keyword(s):

Gene Expression ◽

Ionizing Radiation ◽

Hela Cells ◽

Cellular Response ◽

Radiation Treatment ◽

Signal Transduction Pathway ◽

Cell Types ◽

Jurkat Cells ◽

Protein Signaling ◽

Gene Encoding

The expression of many genes is modulated after exposure to ionizing radiation. Identification of specific genes may allow the determination of pathways important in radiation responses. We previously identified modulation of the expression of several genes in response to ionizing radiation treatment. In the present study, we monitored the expression of RGS1, CC3, THBS1, vWF, MADH7, and a novel gene encoding a secreted protein in irradiated Jurkat, TK6, HeLa, and HFL1 cells. The RGS1 is involved in G-protein signaling pathway, CC3 belongs to the complement system, THBS1 is a component of the extracellular matrix, vWF takes part in blood coagulation, and MADH7 is a member of the TGF-βsignal transduction pathway. Our objective was to find similarities and differences in the expression of these genes in ionizing radiation-exposed diverse cell types. RGS1 was downregulated in Jurkat cells but was upregulated in TK6 and HFL1 cells. The expression of CC3 was repressed in Jurkat and HFL1 cells but was induced in TK6 and HeLa cells. THBS1 was downregulated in irradiated TK6 and HFL1 cells. vWF was induced in radiation-exposed HeLa cells, but its expression was downregulated in Jurkat cells. The expression of MADH7 was induced in all the cell types examined. These results indicate cell specific modulation of gene expression and suggest the involvement of different pathways in cellular response to radiation treatment in different cells.

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Independent regulation by sodium butyrate of gonadotropin alpha gene expression and cell cycle progression in HeLa cells.

Molecular and Cellular Biology ◽

10.1128/mcb.4.5.829 ◽

1984 ◽

Vol 4 (5) ◽

pp. 829-839 ◽

Cited By ~ 24

Author(s):

R B Darnell

Keyword(s):

Gene Expression ◽

Cell Cycle ◽

Sodium Butyrate ◽

Hela Cells ◽

Cell Cycle Progression ◽

Direct Action ◽

Cell Types ◽

Neoplastic Cell ◽

Alpha Subunit ◽

Alpha Gene

Sodium butyrate alters the growth and gene expression of a variety of differentiating and neoplastic cell types. For example, addition of 5 mM butyrate to HeLa cells is reported to both induce gonadotropin alpha subunit biosynthesis and block cell cycling in G1. We have studied these two actions of butyrate on HeLa cells and found that they are regulated in distinct ways. The induction of alpha subunit synthesis was due to an increase in the rate of transcription of the alpha gene. Using synchronized populations of HeLa cells, we determined that butyrate stimulates alpha transcription throughout the cell cycle. In contrast, treated cells arrest in G1 only if exposed to butyrate for a discrete period during the previous S phase. We conclude that butyrate inhibits DNA synthesis through a cell cycle-specific action that is independent from its direct action to stimulate transcription of the gonadotropin alpha gene.

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Morpho-Physiological Testing of NaCl Sensitivity of Tobacco Plants Overexpressing Choline Oxidase Gene

Plants ◽

10.3390/plants10061102 ◽

2021 ◽

Vol 10 (6) ◽

pp. 1102

Author(s):

Galina N. Raldugina ◽

Sergey V. Evsukov ◽

Liliya R. Bogoutdinova ◽

Alexander A. Gulevich ◽

Ekaterina N. Baranova

Keyword(s):

Choline Oxidase ◽

Culture Methods ◽

Gene Encoding ◽

Oxidase Gene ◽

Bacterial Enzyme ◽

Transgenic Lines ◽

High Regeneration ◽

Whole Plants ◽

Implicit Response

In this study the transgenic lines (TLs) of tobacco (Nicotianatabacum L.), which overexpress the heterologous gene encoding the bacterial enzyme choline oxidase were evaluated. The goal of our work is to study the effect of choline oxidase gene expression on the sensitivity of plant tissues to the action of NaCl. The regenerative capacity, rhizogenesis, the amount of photosynthetic pigments and osmotically active compounds (proline and glycine betaine) were assessed by in vitro cell culture methods using biochemical and morphological parameters. Transgenic lines with confirmed expression were characterized by high regeneration capacity from callus in the presence of 200 mmol NaCl, partial retention of viability at 400 mmol NaCl. These data correlated with the implicit response of regenerants and whole plants to the harmful effects of salinity. They turned out to be less sensitive to the presence of 200 mmol NaCl in the cultivation medium, in contrast to the WT plants.

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Interaction of Candida albicans with genital mucosa: effect of sex hormones on adherence of yeasts in vitro

Canadian Journal of Microbiology ◽

10.1139/m88-042 ◽

1988 ◽

Vol 34 (3) ◽

pp. 224-228 ◽

Cited By ~ 12

Author(s):

Aliza Kalo ◽

Esther Segal

Keyword(s):

Candida Albicans ◽

Hela Cell ◽

Sex Hormones ◽

Hela Cells ◽

Cell Types ◽

Vaginal Candidiasis ◽

Genital Mucosa ◽

Hela Cell Lines ◽

I Cells

Findings from our previous studies revealed a correlation between the level of adherence in vitro of Candida albicans to human exfoliated vaginal epithelial cells (VEC) and the hormonal status of the cell donors. In the present study we investigated the effect of the sex hormones estradiol, estriol, progesterone, and testosterone on the binding of the yeasts to HeLa cell lines and VEC in vitro. Monolayers of HeLa cells were exposed to the hormones and yeasts under controlled conditions. The number of adherent yeasts per square millimetre of HeLa cell monolayers and the percentage of VEC with adherent yeasts was estimated by microscopic counts. The results showed that the tested sex hormones affected at various degrees the adhesion of yeasts to HeLa cells or VEC. Progesterone had the most marked effect, leading to a significant increase in the number of adherent yeasts to HeLa cells or in the percentage of adhesion of VEC. In addition, VEC were separated on Percoll gradients into the two cell types: superficial (S) and intermediate (I), cell types which appear physiologically under increased serum levels of estradiol or progesterone, respectively. Adhesion assays with the separated cell populations revealed an increased binding capacity of the I cells. The finding that progesterone increased the adherence of yeasts to genital mucosa and that VEC of the I type have a higher capacity to adhere the yeasts is compatible with our previous observation that increased numbers of I cells, appearing under high level of progesterone, are found in situations known to have predisposition to vaginal candidiasis. Thus, our data point to a possible involvement of the hormone progesterone in the adherence of C. albicans to genital epithelium.

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Microinjection of Francisella tularensis and Listeria monocytogenes Reveals the Importance of Bacterial and Host Factors for Successful Replication

Infection and Immunity ◽

10.1128/iai.00416-15 ◽

2015 ◽

Vol 83 (8) ◽

pp. 3233-3242 ◽

Cited By ~ 9

Author(s):

Lena Meyer ◽

Jeanette E. Bröms ◽

Xijia Liu ◽

Martin E. Rottenberg ◽

Anders Sjöstedt

Keyword(s):

Listeria Monocytogenes ◽

Francisella Tularensis ◽

Hela Cells ◽

Cell Types ◽

Metabolic Adaptation ◽

Content Type ◽

Bacterial Uptake ◽

J774 Cells ◽

Cell Cytosol ◽

Successful Replication

Certain intracellular bacteria use the host cell cytosol as the replicative niche. Although it has been hypothesized that the successful exploitation of this compartment requires a unique metabolic adaptation, supportive evidence is lacking. ForFrancisella tularensis, many genes of theFrancisellapathogenicity island (FPI) are essential for intracellular growth, and therefore, FPI mutants are useful tools for understanding the prerequisites of intracytosolic replication. We compared the growth of bacteria taken up by phagocytic or nonphagocytic cells with that of bacteria microinjected directly into the host cytosol, using the live vaccine strain (LVS) ofF. tularensis; five selected FPI mutants thereof, i.e., ΔiglA, ΔiglÇ ΔiglG, ΔiglI, and ΔpdpEstrains; andListeria monocytogenes. After uptake in bone marrow-derived macrophages (BMDM), ASC−/−BMDM, MyD88−/−BMDM, J774 cells, or HeLa cells, LVS, ΔpdpEand ΔiglGmutants, andL. monocytogenesreplicated efficiently in all five cell types, whereas the ΔiglAand ΔiglCmutants showed no replication. After microinjection, all 7 strains showed effective replication in J774 macrophages, ASC−/−BMDM, and HeLa cells. In contrast to the rapid replication in other cell types,L. monocytogenesshowed no replication in MyD88−/−BMDM and LVS showed no replication in either BMDM or MyD88−/−BMDM after microinjection. Our data suggest that the mechanisms of bacterial uptake as well as the permissiveness of the cytosolic compartmentper seare important factors for the intracytosolic replication. Notably, none of the investigated FPI proteins was found to be essential for intracytosolic replication after microinjection.

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Stable transfer and restricted expression of a cloned class I gene encoding a secreted transplantation-like antigen

Molecular and Cellular Biology ◽

10.1128/mcb.5.6.1295-1300.1985 ◽

1985 ◽

Vol 5 (6) ◽

pp. 1295-1300

Author(s):

Y Barra ◽

K Tanaka ◽

K J Isselbacher ◽

G Khoury ◽

G Jay

Keyword(s):

Molecular Mechanisms ◽

Cell Types ◽

Class I ◽

Regulatory Sequences ◽

Transcriptional Enhancer ◽

Gene Encoding ◽

Specific Expression ◽

Tissue Specific ◽

Functional Studies ◽

I Gene

The identification of a unique major histocompatibility complex class I gene, designated Q10, which encodes a secreted rather than a cell surface antigen has led to questions regarding its potential role in regulating immunological functions. Since the Q10 gene is specifically activated only in the liver, we sought to define the molecular mechanisms which control its expression in a tissue-specific fashion. Results obtained by transfection of the cloned Q10 gene, either in the absence or presence of a heterologous transcriptional enhancer, into a variety of cell types of different tissue derivations are consistent with the Q10 gene being regulated at two levels. The first is by a cis-dependent mechanism which appears to involve site-specific DNA methylation. The second is by a trans-acting mechanism which would include the possibility of an enhancer binding factor. The ability to efficiently express the Q10 gene in certain transfected cell lines offers an opportunity to obtain this secreted class I antigen in quantities sufficient for functional studies; this should also make it possible to define regulatory sequences which may be responsible for the tissue-specific expression of Q10.

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Different cis-acting DNA elements control expression of the human apolipoprotein AI gene in different cell types

Molecular and Cellular Biology ◽

10.1128/mcb.8.2.605-614.1988 ◽

1988 ◽

Vol 8 (2) ◽

pp. 605-614

Author(s):

K N Sastry ◽

U Seedorf ◽

S K Karathanasis

Keyword(s):

Hela Cells ◽

Hepatoma Cell ◽

Plasma Lipid ◽

Cell Types ◽

Apolipoprotein Ai ◽

Transcriptional Enhancer ◽

Regulation Of Expression ◽

Cis Acting ◽

Human Apolipoprotein ◽

Mammalian Liver

In mammals, the gene coding for apolipoprotein AI (apoAI), a protein of the plasma lipid transport system, is expressed only in the liver and the intestine. A series of plasmids containing various lengths of sequences flanking the 5' end of the human apoAI gene were constructed and assayed for transient expression after introduction into cultured human hepatoma (HepG2), colon carcinoma (Caco-2), and epithelial (HeLa) cells. The results showed that while most of these constructs are expressed in HepG2 and Caco-2 cells, none of them is expressed in HeLa cells. In addition, the results indicated that a DNA segment located between nucleotides -256 and -41 upstream from the transcription start site of this gene is necessary and sufficient for maximal levels of expression in HepG2 but not in Caco-2 cells, while a DNA segment located between nucleotides -2052 and -192 is required for maximal levels of expression in Caco-2 cells. Moreover, it was shown that the -256 to -41 DNA segment functions as a hepatoma cell-specific transcriptional enhancer with both homologous and heterologous promoters. These results indicate that different cis- and possibly trans-acting factors are involved in the establishment and subsequent regulation of expression of the apoAI gene in the mammalian liver and intestine.

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Promoter and enhancer elements from the rat elastase I gene function independently of each other and of heterologous enhancers

Molecular and Cellular Biology ◽

10.1128/mcb.7.10.3466-3472.1987 ◽

1987 ◽

Vol 7 (10) ◽

pp. 3466-3472

Author(s):

D M Ornitz ◽

R E Hammer ◽

B L Davison ◽

R L Brinster ◽

R D Palmiter

Keyword(s):

Fusion Gene ◽

Leukemia Virus ◽

Human Growth ◽

Cell Types ◽

Regulatory Elements ◽

Pancreatic Acinar Cells ◽

Gene Promoters ◽

Base Pairs ◽

Metallothionein Gene ◽

Rat Elastase

An elastase-human growth hormone (hGH) fusion gene containing 205 base pairs of elastase 5' flanking region is expressed exclusively in pancreatic acinar cells of transgenic mice. This paper shows that the promoter region (-72 to +8) and the enhancer (-205 to -73) function independently of each other. The elastase enhancer can activate the heterologous mouse metallothionein gene and the hGH gene promoters; conversely, enhancers from the thymocyte-specific murine leukemia virus MCF13 and the metal regulatory elements from the metallothionein gene can activate the elastase promoter in a variety of cell types. Combinations of immunoglobulin and elastase enhancers with a heterologous promoter and the hGH gene result in expression in all of the tissues predicted by the sum of each enhancer acting alone. Thus these enhancer elements act independently of each other, suggesting that they do not have silencing activity in cells in which they are normally inactive.

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