Failure of Embryonic Hematopoiesis andLethal Hemorrhages in Mouse Embryos Heterozygousfor a Knocked-In Leukemia Gene CBFB–MYH11

Castilla, Lucio H.; Wijmenga, Cisca; Wang, Qing; Stacy, Terryl; Speck, Nancy A.; Eckhaus, Michael; Marín-Padilla, Miguel; Collins, Francis S.; Wynshaw‐Boris, Anthony; Liu, Pu P.

doi:10.1016/s0092-8674(00)81388-4

Cited by 269 publications

(245 citation statements)

References 38 publications

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“…Consistent with the importance of CBF for the growth and maturation of immature blood cells, gene rearrangements involving CBF subunits are commonly found in AML (as recently reviewed, Liu et al, 1995;Nucifora and Rowley, 1995) and in pediatric B-lineage ALL (Golub et al, 1995;Romana et al, 1995). Remarkably, mice derived from ES cells heterozygous for CBFb-SMMHC at the CBFb locus or for AML1-ETO at the AML1 locus, displayed the same phenotypes as did CBFb or AML1 null mice, including lack of de®nitive hematopoiesis (Castilla et al, 1996;Okuda et al, 1996b;Yergeau et al, 1997). Also, AML1-ETO interfered with transactivation by AML1 Frank et al, 1995), and CBFb-SMMHC inhibited CBF DNA-binding in vitro and in NIH3T3 cells .…”

Section: Discussionmentioning

confidence: 96%

“…Mice in which the CBFb-SMMHC or AML1-ETO cDNAs had been`knocked-in' to their normal loci failed to develop de®nitive hematopoiesis and died in utero (Castilla et al, 1996;Okuda et al, 1996b;Yergeau et al, 1997). These phenotypes are identical to that of AML1 and CBFb null mice, providing additional evidence that these oncoproteins act by inhibiting CBF functions.…”

Section: Introductionmentioning

confidence: 89%

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CBFβ-SMMHC, expressed in M4Eo AML, reduced CBF DNA-binding and inhibited the G1 to S cell cycle transition at the restriction point in myeloid and lymphoid cells

Cao¹,

Britos-Bray²,

Claxton

et al. 1997

Oncogene

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107

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CBFb-SMMHC is expressed from the inv(16) chromosome in M4Eo AML. Mice lacking CBF subunits or expressing the CBFb-SMMHC or AML1-ETO oncoproteins failed to develop de®nitive hematopoiesis. To investigate these e ects on hematopoiesis, we expressed CBFb-SMMHC from the metallothionein promoter, in both 32D cl3 myeloid cells and Ba/F3 B-lymphoid cells. Addition of zinc increased CBFb-SMMHC levels more than tenfold, with higher levels evident in Ba/F3 lines. Levels obtained in 32D cl3 cells were similar to those of endogenous CBFb. Indirect immuno¯uorescence revealed zinc-inducible speckled, nuclear staining in Ba/F3 cells and di use nuclear staining in 32D cl3 cells. CBFb-SMMHC reduced endogenous CBF DNA-binding ®vefold in both cell types, increased cell generation time 1.9-fold, on average, in 32D cl3 cells and 1.5-fold in Ba/ F3 cells and decreased tritiated thymidine incorporation into DNA correspondingly. CBFb-SMMHC increased the proportion of cells in G1 1.7-fold, on average, in 32D cl3 and Ba/F3 cells, and decreased the proportion of cells in S phase by a similar degree. CBFb-SMMHC induced a marked increase in hypophosphorylated Rb, but did not alter IL-3 Receptor a or b subunit levels. Neither apoptosis nor 32D di erentiation was induced by zinc in IL-3 in these lines. Induction of CBFb-SMMHC in 32D cl3 cells did not inhibit their di erentiation to neutrophils or their expression of myeloperoxidase mRNA in G-CSF, and did not produce an eosinophilic phenotype. Additional, proliferative genetic changes in M4eo AMLs might potentiate inhibition of di erentiation by CBFb-SMMHC by allowing its increased expression.

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Section: Discussionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 89%

CBFβ-SMMHC, expressed in M4Eo AML, reduced CBF DNA-binding and inhibited the G1 to S cell cycle transition at the restriction point in myeloid and lymphoid cells

Cao¹,

Britos-Bray²,

Claxton

et al. 1997

Oncogene

Self Cite

107

View full text Add to dashboard Cite

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“…The CBFb subunit is altered in the inv(16) chromosomal abnormality, to form a CBFb-MYH11 fusion protein (Liu et al, 1993). Both AML1/ETO (Okuda et al, 1998;Yergeau et al, 1997) and CBFb-MYH11 (Castilla et al, 1996) knock-in mice fail to develop de®nitive hematopoiesis, suggesting that the fusion proteins could account for the block in di erentiation characteristic of AML. However, because of the lethal phenotype of the knock-in mice, the role of the fusion proteins in leukemogenesis has remained unclear.…”

Section: Discussionmentioning

confidence: 99%

The t(8;21) fusion protein, AML1/ETO, transforms NIH3T3 cells and activates AP-1

et al. 1999

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The 8;21 translocation is the most common cytogenetic abnormality in human acute myelogenous leukemia, joining the AML1 gene on chromosome 21, to the ETO gene on chromosome 8, forming the AML1/ETO fusion gene. The AML1/ETO fusion protein has been shown to function mainly as a transcriptional repressor of AML1 target genes and to block AML1 function in vitro and in vivo. However, AML1/ETO can also activate the BCL-2 promoter and cause enhanced hematopoietic progenitor self-renewal in vitro, suggesting gain-of-functions unique to the fusion protein. We used NIH3T3 cells to determine the transforming capacity of AML1/ETO, and to further characterize its mechanism of action. Expression of AML1/ETO in NIH3T3 cells caused cell-type speci®c cell death, and cellular transformation, characterized by phenotypic changes, anchorage-independent growth, and tumor formation in nude mice. In contrast, neither expression of AML1A, AML1B or ETO altered the normal growth pattern of the cells. To investigate the mechanism of transformation by AML1/ETO, we analysed the levels of activated, phosphorylated c-Jun (ser63) and other constituents of the AP-1 complex, in the presence of various AML1/ ETO related proteins. Expression of AML1/ETO increased the level of c-Jun-P (ser63), and activated AP-1 dependent transcription, which was inhibited by expression of a dominant-negative c-Jun protein. Mutational analysis revealed that the runt homology domain (RHD) and a C-terminal transcriptional repression domain in AML1/ETO are required for transformation, activation of c-Jun and increased AP-1 activity. These results establish the transforming potential of the t(8;21) fusion protein and link this gain-of-function property to modulation of AP-1 activity.

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“…The a subunit, with DNA binding properties, contains a region of homology with the runt gene of Drosophila (Daga et al, 1992) and the b subunit stabilizes the binding of the a subunit to DNA. Recent work has demonstrated that both subunits are essential for a correct hematopoiesis (Okuda et al, 1996;Wang et al, 1996a,b;Castilla et al, 1996;Sasaki et al, 1996;Yergeau et al, 1997;Niki et al, 1997) and that their disruption may be crucial for leukemogenesis. Other genes are found involved together with the CBF genes in di erent leukemia subtypes.…”

Section: Introductionmentioning

confidence: 99%

Subcellular localization of the oncoprotein MTG8 (CDR/ETO) in neural cells

et al. 1998

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The t(8;21) translocation associated with acute myeloid leukemia (AML) disrupts two genes, the AML1 gene also known as the core binding factor A2 (CBFA2) on chromosome 21, and a gene on chromosome 8, hereafter referred to as MTG8, but also known as CDR and ETO. Extensive information is available on AML1, a member of the CBF family of transcription factors, containing a highly conserved domain, the runt box, of the Drosophila segmentation gene runt. This gene is essential for the hematopoietic development and is found disrupted in several leukemias. In contrast, the function of the MTG8 gene is poorly understood. The predicted protein sequence shows two unusual, putative zinc-®ngers, three proline-rich regions, a PEST domain and several phosphorylation sites. In addition, we found a region encompassing aa 443 ± 514 predicted to have a signi®cant propensity to form coiled coil structures. MTG8 displays a high degree of similarity with nervy, a homeotic target gene of Drosophila, expressed in the nervous system. Human and mouse wild-type MTG8 are also highly expressed in brain relative to other tissues. For these reasons, we set out to investigate the expression and subcellular localization of the MTG8 protein in neural cells. Immunohistochemical experiments in a 12.5-dayold mouse embryo clearly showed that the protein was expressed in the neural cells of the developing brain and the spinal cord. In primary cultures of hippocampal neurons of 2 ± 3 day-old mice, MTG8 was found in the nucleus, in the cytoplasm and as ®ne granules in the neurites. Cytoplasmic localization of the protein was observed in Purkinje cells of both human and mouse cerebellum. The molecular mass of MTG8 in total human and mouse brain was analysed by immunoblotting and determined to be between 70 and 90 kDa. Isoforms with the same molecular mass were demonstrated in synaptosomes isolated from mouse forebrain. The evidence of MTG8 in the nucleus and cytoplasm of neural cells suggests a speci®c mechanism regulating the subcellular localization of the protein.

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Failure of Embryonic Hematopoiesis andLethal Hemorrhages in Mouse Embryos Heterozygousfor a Knocked-In Leukemia Gene CBFB–MYH11

Cited by 269 publications

References 38 publications

CBFβ-SMMHC, expressed in M4Eo AML, reduced CBF DNA-binding and inhibited the G1 to S cell cycle transition at the restriction point in myeloid and lymphoid cells

CBFβ-SMMHC, expressed in M4Eo AML, reduced CBF DNA-binding and inhibited the G1 to S cell cycle transition at the restriction point in myeloid and lymphoid cells

The t(8;21) fusion protein, AML1/ETO, transforms NIH3T3 cells and activates AP-1

Subcellular localization of the oncoprotein MTG8 (CDR/ETO) in neural cells

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