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

1979 ◽  
Vol 76 (9) ◽  
pp. 4511-4515 ◽  
Author(s):  
R. Gambari ◽  
P. A. Marks ◽  
R. A. Rifkind
1991 ◽  
Vol 11 (9) ◽  
pp. 4690-4697 ◽  
Author(s):  
J G Glauber ◽  
N J Wandersee ◽  
J A Little ◽  
G D Ginder

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.


1991 ◽  
Vol 11 (9) ◽  
pp. 4690-4697
Author(s):  
J G Glauber ◽  
N J Wandersee ◽  
J A Little ◽  
G D Ginder

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.


FEBS Letters ◽  
1996 ◽  
Vol 386 (2-3) ◽  
pp. 95-98 ◽  
Author(s):  
Bianca Sparatore ◽  
Edon Melloni ◽  
Mauro Patrone ◽  
Mario Passalacqua ◽  
Sandro Pontremoli

Blood ◽  
1985 ◽  
Vol 65 (3) ◽  
pp. 705-712 ◽  
Author(s):  
NP Anagnou ◽  
TY Yuan ◽  
E Lim ◽  
J Helder ◽  
S Wieder ◽  
...  

Abstract In order to test if trans-acting regulatory factors specific for globin genes of the adult and embryonic stages of development exist in erythroid cells, transcriptionally active embryonic and adult globin genes on the same chromosome were transferred by cell fusion from the human leukemia cell K562 into phenotypically adult mouse erythroleukemia cells. Restriction-fragment-length polymorphisms of the K562 zeta (embryonic) globin genes were used to establish that all three copies of human chromosome 16 present in the K562 cell showed the same pattern of human globin gene expression after transfer to the mouse erythroleukemia cell. Adult (alpha) but not embryonic (zeta) human globin mRNA was detected in all nine of the independently derived mouse erythroleukemia hybrid cells, each of which contained human chromosome 16. Restriction endonuclease studies of the K562 alpha- and zeta-globin genes after transfer into the mouse erythroleukemia cell showed no evidence of rearrangements or deletions that could explain this loss of zeta-globin gene expression. These data suggest that regulation of globin gene expression in these erythroleukemia cells involves trans-acting regulatory factors specific for the adult and embryonic stages of development.


Blood ◽  
1997 ◽  
Vol 89 (4) ◽  
pp. 1383-1393 ◽  
Author(s):  
Toshiyuki Yamada ◽  
Nobuo Kondoh ◽  
Mana Matsumoto ◽  
Midori Yoshida ◽  
Akihiko Maekawa ◽  
...  

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.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4797-4797
Author(s):  
Diana Santos Branco ◽  
Ana Flavia Brugnerotto ◽  
Carolina Lanaro ◽  
Kleber Yotsumoto Fertrin ◽  
Anderson Ferreira Cunha ◽  
...  

Abstract Abstract 4797 Background: Extensive studies have led to a considerable understanding of the cellular and molecular control of haemoglobin production during red blood cell differentiation, however, identification of the genes expressed as part of the erythroid differentiation programme remains an important goal because of the insights that these data will bring to erythrocyte biology and disease. Previous results using SAGE identified 93 differentially-expressed genes during erythroid development. One of these genes, EYA3, a homologue gene of Eyes Absent 3 in Drosophila, is a transcription cofactor with intrinsic phosphatase activity and its expression was observed to be high at the end of CD34+ cell differentiation and in human bone marrow. Aim: To evaluate globin gene, fetal hemoglobin (HbF) expressions and apoptosis levels in the erythroleukemic K562 cell line after EYA3 gene silencing and induction with hemin. Methods: Four different cultures from human K562 cells (1×105cells/mL in DMEM, 10% FBS, penicillin/streptomycin, 5% CO2, 37°C) were transfected with control or EYA3 knockdown lentiviruses (MOI=2.5). After proliferation and selection of successfully transfected cells with puromicin (2.0 ug/mL), cells were treated with 30μM hemin and collected after 0, 24, 48, 72 and 96h for gene expression and flow cytometry analyses. EYA3, LXN, α, and g-gene expression was measured by qRT-PCR and normalized using the Genorm program. HbF expression and apoptosis were evaluated by flow cytometry. Results: Analysis of globin gene expression showed that α-globin gene was downregulated in EYA3 silenced K562 culture cells compared with the control culture in 72h after hemin addition (1.791±0.1735; 0.7404±0.1709, respectively, **P<0.001, n=4). g-globin gene expression was found to be downregulated in K562 EYA3 silenced culture after 24h (1.350±0.1296; 0.5285±0.1736, respectively, *P<0.05, n=4) and 72h (1.554±0.1042; 0.6889±0.1535, respectively, **P<0.001, n=4). HbF expression was found to be downregulated in the same culture compared to the control culture at 72h after hemin addition (3568±41.00; 1947±206.50, respectively, *P<0.05, n=4). Apoptosis levels were found increased in EYA3 silenced K562 culture cells compared with the control culture in 72h after hemin addition (4.7±0.10; 8.55±0.55, respectively, *P<0.001, n=4). Conclusions: Our results show that silencing EYA causes modifications in the expression pattern of α- and g-globin gene expression as well as in HbF expression pattern and apoptosis levels in a model of erythroid differentiation. Further studies should be performed in primary erythroid cell cultures using siRNA-based gene silencing and overexpression of these genes to determine how these genes are involved in the mechanisms of globin gene regulation. Support by FAPESP, CNPq and INCTS Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2000 ◽  
Vol 96 (1) ◽  
pp. 334-339 ◽  
Author(s):  
E. Camilla Forsberg ◽  
Karen M. Downs ◽  
Emery H. Bresnick

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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