Expression of the human beta-globin gene after retroviral transfer into murine erythroleukemia cells and human BFU-E cells

1988 ◽  
Vol 8 (4) ◽  
pp. 1725-1735
Author(s):  
M A Bender ◽  
A D Miller ◽  
R E Gelinas

Replication-defective amphotropic retrovirus vectors containing either the human beta-globin gene with introns or an intronless beta-globin minigene were constructed and used to study beta-globin expression following gene transfer into hematopoietic cells. The beta-globin genes were marked by introducing a 6-base-pair insertion into the region corresponding to the 5' untranslated region of the beta-globin mRNA to allow detection of RNA encoded by the new gene in human cells expressing normal human beta-globin RNA. Introduction of a virus containing the beta-globin gene with introns into murine erythroleukemia cells resulted in inducible expression of human beta-globin RNA and protein, while the viruses containing the minigene were inactive. The introduced human beta-globin gene was 6 to 110% as active as the endogenous mouse beta maj-globin genes in six randomly chosen cell clones. Introduction of the viruses into human BFU-E cells, followed by analysis of marked and unmarked globin RNAs in differentiated erythroid colonies, revealed that the introduced beta-globin gene was about 5% as active as the endogenous genes in these normal human erythroid cells and that again the minigene was inactive. These data are discussed in terms of the potential treatment of genetic disease by gene therapy.

1988 ◽  
Vol 8 (4) ◽  
pp. 1725-1735 ◽  
Author(s):  
M A Bender ◽  
A D Miller ◽  
R E Gelinas

Replication-defective amphotropic retrovirus vectors containing either the human beta-globin gene with introns or an intronless beta-globin minigene were constructed and used to study beta-globin expression following gene transfer into hematopoietic cells. The beta-globin genes were marked by introducing a 6-base-pair insertion into the region corresponding to the 5' untranslated region of the beta-globin mRNA to allow detection of RNA encoded by the new gene in human cells expressing normal human beta-globin RNA. Introduction of a virus containing the beta-globin gene with introns into murine erythroleukemia cells resulted in inducible expression of human beta-globin RNA and protein, while the viruses containing the minigene were inactive. The introduced human beta-globin gene was 6 to 110% as active as the endogenous mouse beta maj-globin genes in six randomly chosen cell clones. Introduction of the viruses into human BFU-E cells, followed by analysis of marked and unmarked globin RNAs in differentiated erythroid colonies, revealed that the introduced beta-globin gene was about 5% as active as the endogenous genes in these normal human erythroid cells and that again the minigene was inactive. These data are discussed in terms of the potential treatment of genetic disease by gene therapy.


1986 ◽  
Vol 6 (11) ◽  
pp. 3873-3883
Author(s):  
C B Kerlakian ◽  
S W Toth ◽  
E D Kuempel ◽  
D S Luse

We assembled three hybrid beta-globin genes by fusing the mouse beta-major promoter and initial transcribed region to one of three goat beta-like globin gene bodies: beta c (preadult), beta F (fetal), or epsilon II (embryonic). Thymidine kinase (tk)-deficient murine erythroleukemia (MEL) cells were cotransformed with one of these constructs and a separate plasmid bearing the tk gene. Half of the 24 cell lines containing either the mouse beta/goat beta c or mouse beta/goat beta F genes expressed the transferred genes at significant levels; in many cases the hybrid genes were, like the endogenous beta-globin genes, inducible with dimethyl sulfoxide. We obtained 13 cell lines containing the mouse beta/goat epsilon II hybrid gene, 6 of which were cotransfected with a mouse beta/human beta fusion gene known to function in MEL cells. In contrast to the results with the other fusion genes, the mouse beta/goat epsilon II hybrid was very poorly expressed: in two separate experiments, 0 of 13 and 2 of 13 lines showed significant mouse beta/goat epsilon II RNA levels after induction. In all these lines the endogenous mouse beta and cotransfected mouse beta/human beta genes were expressed. As an initial test of possible reasons for the inactivity of the mouse beta/goat epsilon II hybrid, we recloned this fusion gene into a tk-bearing plasmid, adjacent to the tk gene. Of 12 cell lines transformed with this plasmid, 11 produced mouse beta/goat epsilon II RNA; in 6 cases the expression was both strong and dimethyl sulfoxide inducible.


1983 ◽  
Vol 3 (2) ◽  
pp. 229-232 ◽  
Author(s):  
H R Profous-Juchelka ◽  
R C Reuben ◽  
P A Marks ◽  
R A Rifkind

The mechanism responsible for the accumulation of newly synthesized alpha- and beta-globin mRNA in the cytoplasm of induced murine erythroleukemia cells was examined by nuclear mRNA nascent chain elongation (run-off transcription). Hexamethylenebisacetimide, a potent inducer of murine erythroleukemia cell differention, induced high levels of both alpha- and beta-globin gene transcription within 48 to 72 h in culture. Butyric acid, a modest inducer of murine erythroleukemia cells, induced a somewhat lower level of globin gene transcription. With both inducers, alpha-globin transcriptional rates exceeded those of beta-globin. Hemin, on the other hand, showed no detectable increase over the basal rate observed in uninduced cells, even at a time (48 h) when newly synthesized globin mRNA was accumulating in the cytoplasm. These results suggest that there are at least two mechanisms responsible for regulating alpha- and beta-globin structural gene expression in induced murine erythroleukemia cells and that the mechanisms involved are inducer dependent. Hexamethylenebisacetimide and butyric acid increase the rate at which globin genes are transcribed, but hemin appears to allow constitutive levels of transcripts to accumulate.


1986 ◽  
Vol 6 (11) ◽  
pp. 3873-3883
Author(s):  
C B Kerlakian ◽  
S W Toth ◽  
E D Kuempel ◽  
D S Luse

We assembled three hybrid beta-globin genes by fusing the mouse beta-major promoter and initial transcribed region to one of three goat beta-like globin gene bodies: beta c (preadult), beta F (fetal), or epsilon II (embryonic). Thymidine kinase (tk)-deficient murine erythroleukemia (MEL) cells were cotransformed with one of these constructs and a separate plasmid bearing the tk gene. Half of the 24 cell lines containing either the mouse beta/goat beta c or mouse beta/goat beta F genes expressed the transferred genes at significant levels; in many cases the hybrid genes were, like the endogenous beta-globin genes, inducible with dimethyl sulfoxide. We obtained 13 cell lines containing the mouse beta/goat epsilon II hybrid gene, 6 of which were cotransfected with a mouse beta/human beta fusion gene known to function in MEL cells. In contrast to the results with the other fusion genes, the mouse beta/goat epsilon II hybrid was very poorly expressed: in two separate experiments, 0 of 13 and 2 of 13 lines showed significant mouse beta/goat epsilon II RNA levels after induction. In all these lines the endogenous mouse beta and cotransfected mouse beta/human beta genes were expressed. As an initial test of possible reasons for the inactivity of the mouse beta/goat epsilon II hybrid, we recloned this fusion gene into a tk-bearing plasmid, adjacent to the tk gene. Of 12 cell lines transformed with this plasmid, 11 produced mouse beta/goat epsilon II RNA; in 6 cases the expression was both strong and dimethyl sulfoxide inducible.


1983 ◽  
Vol 3 (2) ◽  
pp. 229-232
Author(s):  
H R Profous-Juchelka ◽  
R C Reuben ◽  
P A Marks ◽  
R A Rifkind

The mechanism responsible for the accumulation of newly synthesized alpha- and beta-globin mRNA in the cytoplasm of induced murine erythroleukemia cells was examined by nuclear mRNA nascent chain elongation (run-off transcription). Hexamethylenebisacetimide, a potent inducer of murine erythroleukemia cell differention, induced high levels of both alpha- and beta-globin gene transcription within 48 to 72 h in culture. Butyric acid, a modest inducer of murine erythroleukemia cells, induced a somewhat lower level of globin gene transcription. With both inducers, alpha-globin transcriptional rates exceeded those of beta-globin. Hemin, on the other hand, showed no detectable increase over the basal rate observed in uninduced cells, even at a time (48 h) when newly synthesized globin mRNA was accumulating in the cytoplasm. These results suggest that there are at least two mechanisms responsible for regulating alpha- and beta-globin structural gene expression in induced murine erythroleukemia cells and that the mechanisms involved are inducer dependent. Hexamethylenebisacetimide and butyric acid increase the rate at which globin genes are transcribed, but hemin appears to allow constitutive levels of transcripts to accumulate.


Blood ◽  
1987 ◽  
Vol 70 (3) ◽  
pp. 733-739 ◽  
Author(s):  
D Rund ◽  
C Dobkin ◽  
A Bank

Gene therapy for the beta thalassemias and sickle cell anemia will require high levels of expression of human beta globin genes. One method to achieve this goal is amplification of globin genes transferred into the stem cells in the bone marrow of these patients. If the amplified genes remain normally regulated, they will then further increase their expression on being induced to differentiate along an erythroid pathway. To begin this study, we constructed a plasmid containing a neomycin resistance gene, a human beta globin gene, and a wild-type DHFR cDNA, and transfected it into mouse erythroleukemia cells. All the G418-resistant clones analyzed acquired and expressed the human beta globin gene. By serial passage of the cells in increasing concentrations of methotrexate, the exogenous human beta globin genes were stably amplified in all lines, and all increased their globin mRNA expression roughly proportional to their augmented copy number. Most of the clones further increased their beta globin expression on addition of an erythroid stimulus (dimethylsulfoxide). These results indicate that globin gene amplification may be useful in increasing globin mRNA expression in further experiments whose goal is gene therapy.


Blood ◽  
1987 ◽  
Vol 70 (3) ◽  
pp. 733-739
Author(s):  
D Rund ◽  
C Dobkin ◽  
A Bank

Abstract Gene therapy for the beta thalassemias and sickle cell anemia will require high levels of expression of human beta globin genes. One method to achieve this goal is amplification of globin genes transferred into the stem cells in the bone marrow of these patients. If the amplified genes remain normally regulated, they will then further increase their expression on being induced to differentiate along an erythroid pathway. To begin this study, we constructed a plasmid containing a neomycin resistance gene, a human beta globin gene, and a wild-type DHFR cDNA, and transfected it into mouse erythroleukemia cells. All the G418-resistant clones analyzed acquired and expressed the human beta globin gene. By serial passage of the cells in increasing concentrations of methotrexate, the exogenous human beta globin genes were stably amplified in all lines, and all increased their globin mRNA expression roughly proportional to their augmented copy number. Most of the clones further increased their beta globin expression on addition of an erythroid stimulus (dimethylsulfoxide). These results indicate that globin gene amplification may be useful in increasing globin mRNA expression in further experiments whose goal is gene therapy.


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