Overexpression of PU.1 Induces Growth and Differentiation Inhibition and Apoptotic Cell Death in Murine Erythroleukemia Cells

Abstract PU.1 is a member of the ets family of transcription factors and is expressed in Friend virus-induced murine erythroleukemia (MEL) cells as a consequence of proviral integration into the PU.1/Spi-1 locus. After induction of MEL cell differentiation by treatment with dimethylsulfoxide (DMSO), expression of the PU.1/Spi-1 gene decreased before induction of β-globin gene expression. Overexpression of PU.1 by using a zinc-inducible expression plasmid in MEL cells resulted in unexpected growth inhibition of the transfectants. When PU.1-overexpressing transfectants were treated with DMSO, growth inhibition became much pronounced and apoptosis was induced. Expression of the β-globin gene was not induced under this condition. Neither growth inhibition nor apoptosis was induced in MEL cells after expression of mutant PU.1 proteins with a deletion of the activation domain or the DNA-binding Ets domain irrespective of the presence of DMSO. Interestingly, β-globin gene expression was not induced in the transfectants expressing the former mutant, whereas it was induced in those expressing the latter one in the presence of DMSO. These results indicate that overexpression of PU.1 in MEL cells results in growth and differentiation inhibition and, in conjunction with DMSO treatment, apoptotic cell death. These results also suggest that the activation domain and the Ets domain of PU.1 contribute differently to induction of these effects.

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Murine erythroleukemia cell differentiation: relationship of globin gene expression and of prolongation of G1 to inducer effects during G1/early S.

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.76.9.4511 ◽

1979 ◽

Vol 76 (9) ◽

pp. 4511-4515 ◽

Cited By ~ 27

Author(s):

R. Gambari ◽

P. A. Marks ◽

R. A. Rifkind

Keyword(s):

Gene Expression ◽

Cell Differentiation ◽

Globin Gene ◽

Erythroleukemia Cell ◽

Murine Erythroleukemia ◽

Relationship Of ◽

Globin Gene Expression ◽

Murine Erythroleukemia Cell

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5'-flanking sequences mediate butyrate stimulation of embryonic globin gene expression in adult erythroid cells.

Molecular and Cellular Biology ◽

10.1128/mcb.11.9.4690 ◽

1991 ◽

Vol 11 (9) ◽

pp. 4690-4697 ◽

Cited By ~ 74

Author(s):

J G Glauber ◽

N J Wandersee ◽

J A Little ◽

G D Ginder

Keyword(s):

Gene Expression ◽

Cell Differentiation ◽

Globin Gene ◽

Beta Globin ◽

Erythroid Cells ◽

Adult Chicken ◽

Beta Globin Gene ◽

Flanking Sequences ◽

Murine Erythroleukemia ◽

Globin Gene Expression

A stable transfection assay was used to test the mechanism by which embryonic globin gene transcription is stimulated in adult erythroid cells exposed to butyric acid and its analogs. To test the appropriate expression and inducibility of chicken globin genes in murine erythroleukemia (MEL) cells, an adult chicken beta-globin gene construct was stably transfected. The chicken beta-globin gene was found to be coregulated with the endogenous adult mouse alpha-globin gene following induction of erythroid differentiation of the transfected MEL cells by incubation with either 2% dimethyl sulfoxide (DMSO) or 1 mM sodium butyrate (NaB). In contrast, a stably transfected embryonic chicken beta-type globin gene, rho, was downregulated during DMSO-induced MEL cell differentiation. However, incubation with NaB, which induces MEL cell differentiation, or alpha-amino butyrate, which does not induce differentiation of MEL cells, resulted in markedly increased levels of transcription from the stably transfected rho gene. Analysis of histone modification showed that induction of rho gene expression was not correlated with increased bulk histone acetylation. A region of 5'-flanking sequence extending from -569 to -725 bp upstream of the rho gene cap site was found to be required for both downregulation of rho gene expression during DMSO-induced differentiation and upregulation by treatment with NaB or alpha-amino butyrate. These data are support for a novel mechanism by which butyrate compounds can alter cellular gene expression through specific DNA sequences. The results reported here are also evidence that 5'-flanking sequences are involved in the suppression of embryonic globin gene expression in terminally differentiated adult erythroid cells.

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Hepatocyte nuclear factor-1 beta protects endometriotic cells against apoptotic cell death by up-regulating the expression of antiapoptotic genes†

Biology of Reproduction ◽

10.1093/biolre/ioz127 ◽

2019 ◽

Vol 101 (4) ◽

pp. 686-694 ◽

Cited By ~ 1

Author(s):

Umma Hafsa Preya ◽

Jeong-Hwa Woo ◽

Youn Seok Choi ◽

Jung-Hye Choi

Keyword(s):

Oxidative Stress ◽

Gene Expression ◽

Cell Death ◽

Apoptotic Cell ◽

Apoptotic Cell Death ◽

Nuclear Factor ◽

Hepatocyte Nuclear Factor ◽

Antiapoptotic Gene ◽

Nuclear Factor 1 ◽

Hes Cells

Abstract The overexpression of hepatocyte nuclear factor-1 beta (HNF1β) in endometriotic lesion has been demonstrated. However, the role of HNF1β in endometriosis remains largely unknown. Human endometriotic 12Z cells showed higher level of HNF1β when compared with normal endometrial HES cells. In human endometriotic 12Z cells, HNF1β knockdown increased susceptibility to apoptotic cell death by oxidative stress, while HNF1β overexpression suppressed apoptosis. In addition, HNF1β knockdown and overexpression significantly decreased and increased, respectively, the expression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)-dependent antiapoptotic genes. Knockdown of the antiapoptotic genes significantly reduced the HNF1β-induced resistance against oxidative stress in 12Z cells. Furthermore, HNF1β regulated the transcriptional activity of NF-κB, and an NF-κB inhibitor suppressed the HNF1β-enhanced NF-κB-dependent antiapoptotic gene expression and the resistance of the 12Z cells against cell death. Taken together, these data suggest that HNF1β overexpression may protect endometriotic cells against oxidative damage by augmenting antiapoptotic gene expression.

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XIAP Gene Expression Protects β-Cells and Human Islets from Apoptotic Cell Death

Molecular Pharmaceutics ◽

10.1021/mp100070j ◽

2010 ◽

Vol 7 (5) ◽

pp. 1655-1666 ◽

Cited By ~ 15

Author(s):

Hao Wu ◽

Ravikiran Panakanti ◽

Feng Li ◽

Ram I. Mahato

Keyword(s):

Gene Expression ◽

Cell Death ◽

Apoptotic Cell ◽

Human Islets ◽

Apoptotic Cell Death ◽

Β Cells

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Direct interaction of NF-E2 with hypersensitive site 2 of the β-globin locus control region in living cells

Blood ◽

10.1182/blood.v96.1.334.013k17_334_339 ◽

2000 ◽

Vol 96 (1) ◽

pp. 334-339 ◽

Cited By ~ 4

Author(s):

E. Camilla Forsberg ◽

Karen M. Downs ◽

Emery H. Bresnick

Keyword(s):

Gene Expression ◽

Control Region ◽

Globin Gene ◽

Locus Control Region ◽

Erythroid Cell ◽

Hypersensitive Site ◽

Intact Cells ◽

Erythroleukemia Cells ◽

Murine Erythroleukemia ◽

Globin Gene Expression

The human β-globin locus control region (LCR) confers high-level, tissue-specific expression to the β-globin genes. Tandem Maf recognition elements (MAREs) within the hypersensitive site 2 (HS2) subregion of the LCR are important for the strong enhancer activity of the LCR. Multiple proteins are capable of interacting with these sites in vitro, including the erythroid cell- and megakaryocyte-specific transcription factor, NF-E2. The importance of NF-E2 for β-globin gene expression is evident in murine erythroleukemia cells lacking the p45 subunit of NF-E2. These CB3 cells have a severe defect in - and β-globin gene transcription, which can be restored by expression of NF-E2. However, mice nullizygous for p45 express nearly normal levels of β-globin. Thus, either a redundant factor(s) exists in mice that can functionally replace NF-E2, or NF-E2 does not function through the LCR to regulate β-globin gene expression. To address this issue, we asked whether NF-E2 binds directly to the tandem MAREs of HS2 in intact cells. Using a chromatin immunoprecipitation assay, we provide evidence for NF-E2 binding directly and specifically to HS2 in living erythroleukemia cells and in mouse fetal liver. The specific immunoisolation of HS2 sequences was dependent on the presence of p45 and on intact MAREs within HS2. These results support a direct role for NF-E2 in the regulation of β-globin gene expression through activation of the LCR.

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