Tetracycline as Regulator of Inducible Gene Expression Stage 2: Stable Transfection of Inducible tTA-expressing NIH-3T3 Cells with Tetracycline-regulated Target Genes

2006 ◽  
Vol 2006 (1) ◽  
pp. pdb.prot3957
Author(s):  
Joseph Sambrook ◽  
David W. Russell
Keyword(s):  
Gene Expression ◽  
Target Genes ◽  
Stable Transfection ◽  
3T3 Cells ◽  
Inducible Gene Expression ◽  
Nih 3T3 ◽  
Inducible Gene ◽  
Nih 3T3 Cells

scholarly journals Differential early viral gene expression in two stages of human papillomavirus type 16 DNA-induced malignant transformation.

1987 ◽  
Vol 7 (6) ◽  
pp. 2165-2172 ◽  
Author(s):  
S Yasumoto ◽  
J Doniger ◽  
J A DiPaolo
Keyword(s):  
Gene Expression ◽  
Human Papillomavirus ◽  
Malignant Transformation ◽  
Cell Lines ◽  
Viral Gene Expression ◽  
Viral Gene ◽  
3T3 Cells ◽  
Hpv 16 ◽  
Nih 3T3 ◽  
Nih 3T3 Cells

Human papillomavirus (HPV) type 16 DNA induces progressive transformation in NIH 3T3 cells. Two types of cell lines, PM3T3G0 and PM3T3Fo, were isolated by G418 or focus selection, respectively, after transfection of cells by a recombinant HPV 16 DNA carrying the neo gene. These cell lines exhibited distinct phenotypes compared with controls. Saturation densities of PM3T3G0 and PM3T3Fo lines were two- to three- and five- to sevenfold greater than that of control NIH 3T3 cells, respectively. Neither cell type required high serum for growth, in contrast to NIH 3T3 cells. PM3T3G0 lines were premalignant, whereas PM3T3Fo lines manifested tumorigenicity within 2 weeks. Subpopulations of three PM3T3G0 lines underwent progressive transformation as reflected by focus formation. Analysis of HPV 16-specific mRNA species demonstrated that high levels of early and late gene expression were detected in premalignant PM3T3G0 lines, whereas relatively low quantities of selected gene messages were expressed in malignant transformants. Thus, high levels of viral gene expression are not crucial for malignant transformation.

scholarly journals Cell transformation mediated by homodimeric E2A-HLF transcription factors.

1997 ◽  
Vol 17 (3) ◽  
pp. 1417-1424 ◽  
Author(s):  
T Inukai ◽  
T Inaba ◽  
T Yoshihara ◽  
A T Look
Keyword(s):  
Transcription Factors ◽  
Target Genes ◽  
Fusion Gene ◽  
Dominant Negative ◽  
Fusion Product ◽  
3T3 Cells ◽  
Par Proteins ◽  
Downstream Target ◽  
Nih 3T3 ◽  
Nih 3T3 Cells

The E2A-HLF fusion gene, created by the t(17;19)(q22;p13) chromosomal translocation in pro-B lymphocytes, encodes an oncogenic protein in which the E2A trans-activation domain is linked to the DNA-binding and protein dimerization domain of hepatic leukemia factor (HLF), a member of the proline- and acidic amino acid-rich (PAR) subfamily of bZIP transcription factors. This fusion product binds to its DNA recognition site not only as a homodimer but also as a heterodimer with HLF and two other members of the PAR bZIP subfamily, thyrotroph embryonic factor (TEF) and albumin promoter D-box binding protein (DBP). Thus, E2A-HLF could transform cells by direct regulation of downstream target genes, acting through homodimeric or heterodimeric complexes, or by sequestering normal PAR proteins into nonfunctional heterocomplexes (dominant-negative interference). To distinguish among these models, we constructed mutant E2A-HLF proteins in which the leucine zipper domain of HLF was extended by one helical turn or altered in critical charged amino acids, enabling the chimera to bind to DNA as a homodimer but not as a heterodimer with HLF or other PAR proteins. When introduced into NIH 3T3 cells in a zinc-inducible vector, each of these mutants induced anchorage-independent growth as efficiently as unaltered E2A-HLF, indicating that the chimeric oncoprotein can transform cells in its homodimeric form. Transformation also depended on an intact E2A activator region, providing further support for a gain-of-function contribution to oncogenesis rather than one based on a dominant-interfering or dominant-negative mechanism. Thus, the tumorigenic effects of E2A-HLF and its mutant forms in NIH 3T3 cells favor a straightforward model in which E2A-HLF homodimers bind directly to promoter/enhancer elements of downstream target genes and alter their patterns of expression in early B-cell progenitors.

scholarly journals Regulation of Calreticulin Gene Expression by Calcium

1997 ◽  
Vol 138 (3) ◽  
pp. 547-557 ◽  
Author(s):  
Mathilde Waser ◽  
Nasrin Mesaeli ◽  
Charlotte Spencer ◽  
Marek Michalak
Keyword(s):  
Gene Expression ◽  
Genomic Dna ◽  
Chloramphenicol Acetyltransferase ◽  
Ionophore A23187 ◽  
Mrna Levels ◽  
3T3 Cells ◽  
Transcription Analysis ◽  
Nih 3T3 ◽  
Nih 3T3 Cells

We have isolated and characterized a 12-kb mouse genomic DNA fragment containing the entire calreticulin gene and 2.14 kb of the promoter region. The mouse calreticulin gene consists of nine exons and eight introns, and it spans 4.2 kb of genomic DNA. A 1.8-kb fragment of the calreticulin promoter was subcloned into a reporter gene plasmid containing chloramphenicol acetyltransferase. This construct was then used in transient and stable transfection of NIH/ 3T3 cells. Treatment of transfected cells either with the Ca2+ ionophore A23187, or with the ER Ca2+-ATPase inhibitor thapsigargin, resulted in a five- to sevenfold increase of the expression of chloramphenicol acetyltransferase protein. Transactivation of the calreticulin promoter was also increased by fourfold in NIH/3T3 cells treated with bradykinin, a hormone that induces Ca2+ release from the intracellular Ca2+ stores. Analysis of the promoter deletion constructs revealed that A23187- and thapsigargin-responsive regions are confined to two regions (−115 to −260 and −685 to −1,763) in the calreticulin promoter that contain the CCAAT nucleotide sequences. Northern blot analysis of cells treated with A23187, or with thapsigargin, revealed a fivefold increase in calreticulin mRNA levels. Thapsigargin also induced a fourfold increase in calreticulun protein levels. Importantly, we show by nuclear run-on transcription analysis that calreticulin gene transcription is increased in NIH/3T3 cells treated with A23187 and thapsigargin in vivo. This increase in gene expression required over 4 h of continuous incubation with the drugs and was also sensitive to treatment with cycloheximide, suggesting that it is dependent on protein synthesis. Changes in the concentration of extracellular and cytoplasmic Ca2+ did not affect the increased expression of the calreticulin gene. These studies suggest that stress response to the depletion of intracellular Ca2+ stores induces expression of the calreticulin gene in vitro and in vivo.

scholarly journals E2A-HLF-mediated cell transformation requires both the trans-activation domains of E2A and the leucine zipper dimerization domain of HLF.

1995 ◽  
Vol 15 (6) ◽  
pp. 3247-3255 ◽  
Author(s):  
T Yoshihara ◽  
T Inaba ◽  
L H Shapiro ◽  
J Y Kato ◽  
A T Look
Keyword(s):  
Leucine Zipper ◽  
Target Genes ◽  
Cell Transformation ◽  
Fusion Gene ◽  
Phase Cell ◽  
3T3 Cells ◽  
Dimerization Domain ◽  
Activation Domains ◽  
Nih 3T3 ◽  
Nih 3T3 Cells

The E2A-HLF fusion gene, formed by the t(17;19)(q22;p13) translocation in childhood acute pro-B-cell leukemia, encodes a hybrid protein that contains the paired trans-activation domains of E2A (E12/E47) linked to the basic region/leucine zipper DNA-binding and dimerization domain of hepatic leukemia factor (HLF). To assess the transforming potential of this novel gene, we introduced it into NIH 3T3 murine fibroblasts by using an expression vector that also contained the neomycin resistance gene. Cells selected for resistance to the neomycin analog G418 formed aberrant colonies in monolayer cultures, marked by increased cell density and altered morphology. Transfected cells also grew readily in soft agar, producing colonies whose sizes correlated with E2A-HLF expression levels. Subclones expanded from colonies with high levels of the protein reproducibly formed tumors in nude mice and grew to higher plateau-phase cell densities in reduced-serum conditions than did parental NIH 3T3 cells. By contrast, NIH 3T3 cells expressing mutant E2A-HLF proteins that lacked either of the bipartite E2A trans-activation domains or the HLF leucine zipper domain failed to show oncogenic properties, including anchorage-independent cell growth. Thus, both of the E2A trans-activation motifs and the HLF leucine zipper dimerization domain are essential for the transforming potential of the chimeric E2A-HLF protein, suggesting a model in which aberrant regulation of the expression pattern of downstream target genes contributes to leukemogenesis.

Induction of c-Ha-ras gene expression by double-stranded RNA and interferon requirement

1990 ◽  
Vol 10 (8) ◽  
pp. 4424-4426
Author(s):  
A Maran ◽  
I D Goldberg ◽  
B M Steinberg
Keyword(s):  
Gene Expression ◽  
Transcriptional Activation ◽  
Mrna Levels ◽  
3T3 Cells ◽  
Ras Gene ◽  
Double Stranded Rna ◽  
Beta Interferon ◽  
Nih 3T3 ◽  
Nih 3T3 Cells ◽  
Rna Levels

The addition of double-stranded RNA (dsRNA) to NIH 3T3 cells led to an increase in the RNA levels of c-Ha-ras. The double-stranded configuration was required for the increase in c-Ha-ras mRNA levels, as heat-denatured dsRNA and single-stranded RNA did not have any effect. Nuclear run-on transcription experiments indicated that the increase in c-Ha-ras mRNA levels stimulated by dsRNA was due to transcriptional activation of the gene. The induction of c-Ha-ras gene expression by dsRNA was inhibited by anti-beta interferon antibodies, suggesting that interferon might mediate the induction.

Lithium differentially affects clock gene expression in serum-shocked NIH-3T3 cells

2010 ◽  
Vol 25 (7) ◽  
pp. 924-933 ◽  
Author(s):  
Teresa M Osland ◽  
Johan Fernø ◽  
Bjarte Håvik ◽  
Ivar Heuch ◽  
Peter Ruoff ◽  
...  
Keyword(s):  
Gene Expression ◽  
Clock Gene ◽  
3T3 Cells ◽  
Clock Gene Expression ◽  
Nih 3T3 ◽  
Nih 3T3 Cells
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