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Results 701 - 750 of 857
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Sullivan J - - 1997
The c-myb gene is primarily expressed in hematopoietic cells, and it is overexpressed in many leukemias. The regulation of its expression is of critical importance in hematopoietic cells. We identified the major positive regulatory sites in the 5'-flanking sequence of the human c-myb gene, and we found that the positive ...
Rao G - - 1997
Murine erythroleukemia (MEL) cells are transformed erythroid precursors that are blocked from completing the late stages of erythroid differentiation. A frequent event in the generation of these malignant cells is deregulation of the hematopoietic-specific transcription factor PU.1 (Spi-1) by retroviral insertion of the spleen-focus-forming virus component of Friend virus. During ...
Gao P - - 1996
Morphogen-induced decline in Gialpha triggers F9 teratocarcinoma stem cells to progress to primitive endoderm via activation of protein kinase C and mitogen-activated protein kinase (Gao, P., and Malbon, C. C. (1996) J. Biol. Chem. 271, 9002-9008). Constitutive expression of Gialpha2 blocks, whereas expression of Gsalpha provokes, progression to primitive endoderm, ...
Sala A - - 1996
It was recently reported that B-MYB can overcome p107-induced growth arrest. Here we show that B-MYB autoregulation of its own transcription is specifically suppressed by p107 and transient transfection assays with p107 deletion constructs determined that the carboxyl terminus of the protein, containing the major pocket region, was associated with ...
Taylor D - - 1996
The c-Myb transcription factor is required for the production of most hemopoietic lineages, but information is sparse about its mode of action and the key genes it regulates. We have made an inducible dominant interfering Myb protein, by creating a chimera comprising the DNA binding domain of c-Myb, the Drosophila ...
Frampton J - - 1996
Many oncogenes have been shown to be deregulated transcription factors, yet direct target genes mediating cell transformation remain elusive. Here we describe such a target for v-Myb by exploiting a temperature-sensitive mutant of the E26 avian leukemia virus encoding Myb-Ets. Myeloblasts transformed by the mutant differentiate into macrophages or die ...
Barrera G - - 1996
4-Hydroxynonenal, an aldehyde produced from lipid peroxidation of cellular membranes, inhibits growth and induces differentiation of HL-60 human leukemic cell line. Since it is highly unstable in the culture medium, its effectiveness is increased when added repeatedly to the cell suspension. We have previously demonstrated that HNE inhibits c-myc but ...
Vandenbark G R - - 1996
The c-kit proto-oncogene is expressed in several tissues during development. To understand the mechanisms controlling the expression of this gene, we characterized the human c-kit promoter. Expression is controlled transcriptionally. The 5'-flanking DNA was used to make promoter deletion-reporter constructs that were tested in cells that were either positive or ...
Latham K E - - 1996
We recently reported the cloning and sequencing of the mouse A-myb proto-oncogene cDNA and the abundant expression of this mRNA primarily in the testis of adult mice. The A-myb mRNA is detectable by in situ hybridization specifically in the spermatogenic cells, and is downregulated during terminal differentiation. A low level ...
Bennett J D - - 1996
We have previously shown in mouse NIH3T3 fibroblasts that transcription of the B-myb gene, which encodes a transcription factor required for S phase entry, is repressed through a promoter E2F site in G0/early G1. Transcription repression at this stage of the cell cycle was correlated with binding of a specific ...
Edelman J A - - 1996
1. We recorded visuomotor burst neurons in the deeper layers of the superior colliculus while two monkeys (Macaca fascicularis) made short-latency saccades known as express saccades to visual targets in order to determine whether the visual discharge normally seen for these cells served as the premotor burst during express saccades. ...
Dash A B - - 1996
The c-Myb transcription factor is a proto-oncoprotein whose latent transforming activity can be unmasked by truncation of either terminus. Because both ends of Myb are involved in negative regulation, we tested whether they could associate in a two-hybrid assay and identified a carboxy-terminal motif that interacts with the amino-terminal DNA-binding ...
Rosenthal M A - - 1996
c-myb expression is an indicator of hemopoietic cell proliferation and its down-regulation occurs as an early event in cellular differentiation in vitro. We have previously demonstrated c-Myb protein expression in normal adult colon and tumor-derived colonic cell lines and have also shown that the proliferation of colon carcinoma cell lines ...
Oelgeschläger M - - 1996
The oncoprotein v-Myb is a potent inducer of myeloid leukemias, and its cellular homolog c-Myb plays a crucial role in the regulation of hematopoiesis. Both proteins function as transcriptional regulators. We demonstrate that this function is mediated at least in part by the nuclear co-activator CREB binding protein (CBP). This ...
Page K C - - 1996
Circulating hormones are engaged in initiating and controlling the process of spermatogenesis, however, the Sertoli cell tight junctions prevent these substances from directly influencing the spermatogenic cells. Thus, the Sertoli cells play a vital role in regulating the spermatogenic process. Our studies correlate retinoid action with the transactivation of genes ...
Robinson C - - 1996
Previous studies revealed that transcription of B-Myb, which encodes a transcription factor related to the c-Myb proto-oncoprotein, is cell-cycle regulated by an E2F transcription factor-mediated repression mechanism operating in G0/G1. To begin to determine the consequences of transcriptional regulation on B-Myb function, we report here further studies of B-Myb protein ...
Dooley S - - 1996
Specific binding of nuclear proteins to the region of transcriptional attenuation has been shown to modulate the expression of c-myb, a nuclear proto-oncogene preferentially expressed in lympho-hematopoietic cells. Here, it plays an important role in processes of differentiation and proliferation. The mechanism that regulates c-myb expression is not yet fully ...
Dai P - - 1996
CBP (CREB-binding protein) is a transcriptional coactivator of CREB (cAMP response element-binding) protein, which is directly phosphorylated by PKA (cAMP-dependent protein kinase A). CBP interacts with the activated phosphorylated form of CREB but not with the nonphosphorylated form. We report here that CBP is also a coactivator of the c-myb ...
Gavrias V - - 1996
Diverse eukaryotic organisms share developmental transcription factors with homologous DNA-binding domains. We showed that the developmental regulator AbaA, a member of the ATTS/TEA (AbaA, TEF-1, TEC1, Scalloped/TEF-1, TEC1, AbaA) class of transcription factors of the filamentous fungus Aspergillus nidulans, induces pseudohyphal development in the yeast Saccharomyces cerevisiae. The S. cerevisiae ...
Marhamati D J - - 1996
The members of the Myb family of transcription factors are defined by homology in the DNA-binding domain; all bind the Myb-binding site (MBS) sequence (YG(A/G)C(A/C/G)GTT(G/A)). Here we report that cultured bovine vascular smooth muscle cells (SMCs) express B-myb. Levels of B-myb RNA found in exponential growth were reduced dramatically in ...
Raschellà G - - 1996
B-myb and c-myb expression is high in neuroblastoma cells and declines during retinoic acid-induced differentiation. We show here that B-myb down-regulation during retinoic acid-induced differentiation of LAN-5 neuroblastoma cells occurs at the transcriptional level. In addition, we measured B-myb and c-myb messenger RNA half-lives, and found that, unlike c-myb, B-myb ...
Perrotti D - - 1995
Zinc finger genes encode proteins that act as transcription factors. The myeloid zinc finger 1 (MZF1) gene encodes a zinc finger protein with two DNA-binding domains that recognize two distinct consensus sequences, is preferentially expressed in hematopoietic cells, and may be involved in the transcriptional regulation of hematopoiesis-specific genes. Reverse ...
Batterman H J - - 1995
Bartonella henselae expresses pili phenotypically similar to type 4 pili. B. henselae pilus expression undergoes phase variation with multiple passages. Low-passage-number, piliated B. henselae adhered to and invaded HEp-2 cells to a greater extent than did multiply passaged B. henselae with reduced pilus expression. Pili may be a pathogenic determinant ...
McCann S - - 1995
The c-myb gene is primarily expressed in immature hematopoietic cells, and it is overexpressed in many leukemias. We have investigated the role of negative regulatory sites in the c-myb promoter in the Molt-4 T cell line and in the DHL-9 B cell line. A potential binding site for either the ...
Nürnberg W - - 1995
Human c-myb is normally involved in the regulation of proliferation and differentiation of hematopoietic cells. Until now, only a few reports have described elevated c-myb gene expression in epithelial tissue, suggesting that under certain circumstances, c-Myb protein might play a role during the process of malignant transformation of epithelial cells. ...
Lam E W - - 1995
We demonstrate here that activity of the human B-myb promoter is regulated during the cell cycle by the E2 transcription factor (E2F). Comparison of the human B-myb promoter sequence with that of its murine counterpart revealed an evolutionally conserved sequence that contains an E2F-binding site. In transiently transfected murine NIH3T3 ...
Hsiang Y H - - 1995
An enhancer has been localized 3 kb downstream of the C gamma 1 gene segment of the murine TCR-gamma locus. One element, the gamma 3 site, has been shown to be critical for its functional activity. Here we have determined that Myb-related transcription factors bind to the gamma 3 site ...
Orlic D - - 1995
Pluripotent hematopoietic stem cells (PHSCs) were highly enriched from mouse bone marrow by counterflow centrifugal elutriation, lineage subtraction, and fluorescence-activated cell sorting based on high c-kit receptor expression (c-kitBR). We used reverse transcriptase polymerase chain reaction to assay the c-kitBR subset and the subsets expressing low (c-kitDULL) and no (c-kitNEG) ...
Mizuguchi G - - 1995
The c-myb proto-oncogene product (c-Myb) is a transcriptional activator that can bind to the specific DNA sequences. Although c-Myb also represses an artificial promoter containing the Myb binding sites, natural target genes transcriptionally repressed by c-Myb have not been identified. We have found that the human c-erbB-2 promoter activity is ...
Engelke U - - 1995
The v-myb oncogene causes monoblastic leukemia in chickens and transforms avian myelomonocytic cells in vitro, v-Myb is a short-lived nuclear protein which binds to DNA in a sequence-specific manner and can activate gene expression in transient DNA transfections. Analysis of a series of v-Myb mutants has shown that the ability ...
Raschellà G - - 1995
The B-myb gene belongs to a family of transcription factors that also includes A-myb and c-myb. B-myb is expressed in many cell types including human neuroblastoma cells. Here we demonstrate that B-myb expression is down-regulated during retinoic acid-induced neural and glial differentiation of neuroblastoma cells. This modulation is an early ...
Toth C R - - 1995
Expression of the c-myb proto-oncogene is primarily detected in normal tissue and tumor cell lines of immature hematopoietic origin, and the down-regulation of c-myb expression is associated with hematopoietic maturation. Cell lines that represent mature, differentiated hematopoietic cell types contain 10-100-fold less c-myb mRNA than immature hematopoietic cell types. Differences ...
Kraut N - - 1995
The Myb-Ets oncoprotein encoded by the E26 avian leukaemia virus represents a fusion of two transcription factors which cooperate in transforming multipotent haematopoietic progenitors (MEPs) in vitro and in vivo. Previous studies with a temperature sensitive mutant in ets (ts1.1 E26) have suggested that the Ets part of the Myb-Ets ...
Tewari M - - 1995
A20 is a cytokine-inducible primary response gene that encodes a protein that inhibits apoptosis. We cloned and characterized a murine A20 cDNA and mapped the gene to mouse chromosome 10, 3.5 centimorgans proximal to the c-myb locus. Using the murine cDNA, we conducted in situ hybridization studies to examine patterns ...
Gudas J M - - 1995
We have determined that expression of the c-myb proto-oncogene is associated with estrogen receptor (ER) status and not with tumor progression in human breast epithelial cells. Analysis of normal, immortalized, nontumorigenic, and tumorigenic mammary epithelial cells showed that only ER+ tumor cell lines expressed readily detectable levels of c-myb mRNA ...
Bloch A - - 1995
C-myb and c-ets-1 have variously been demonstrated to function as protooncogenes. Using a human leukemic cell line, ML-1, we have examined the mechanism by which these genes participate in establishing the sustained proliferation mode that is characteristic of the transformed cell. In the absence of serum, ML-1 cells were found ...
Ceusters W - - 1995
This paper describes a formalism in which the knowledge of the Alphabetic Index of ICD is expressed unambiguously in the ANTHEM prototype. The Alphabetic Index may be viewed as a collection of hypotheses on which ICD-codes should be tried first for a given diagnostic expression. The hypotheses generation can be ...
Stöcker U - - 1995
The anthracycline antitumor antibiotic aclarubicin is known to induce granulocytic differentiation in the human myeloid leukemia cell line HL-60. We investigated whether this effect is accompanied by changes in the expression of the protooncogenes c-myc and c-myb. Treatment of HL-60 cells with aclarubicin, 50 nM, caused a rapid decrease in ...
McCracken S - - 1994
The lck gene, which encodes a lymphoid-specific Src family tyrosine kinase, is transcribed from two promoters that are differentially utilized during T cell development. We have shown previously that the human lck type I promoter, which is preferentially expressed in immature thymocytes, requires a binding site (-97 to -90) for ...
Reddy M A - - 1994
The receptor for macrophage colony stimulating factor (CSF-1), the c-fms gene product, is a key determinant in the differentiation of monocytic phagocytes. Dissection of the human and mouse c-fms proximal promoters revealed opposing roles for nuclear protooncogenes in the transcriptional regulation of this gene. On the one hand, c-ets-1, c-ets-2, ...
Wang L G - - 1994
For growth, ML-1 human myeloblastic leukemia cells require insulin-like growth factor 1 together with transferrin, whereas for differentiation they depend upon transforming growth factor beta in combination with transferrin. As shown in this study, growth stimulation is accompanied by c-myb expression, whereas initiation of differentiation results in the cessation of ...
Alleva D G - - 1994
Macrophages (M phi)3 function by a two-step process that includes priming (induction of cytokine and enzyme mRNA) and activation (production of effector molecules). The initial steps in M phi priming involve the expression of certain proto-oncogenes that regulate expression of other genes. Because tumor growth primes M phi to produce ...
Melotti P - - 1994
CD34 is currently the only well defined human hematopoietic stem cell marker and is expressed on 1-4% of normal bone marrow cells. Putative binding sites for Ets proteins, a family of transcription factors involved in the regulation of cell differentiation and proliferation in many cell systems, are present in the ...
Saget B M - - 1994
The adaptive response of Escherichia coli protects the cells against the toxic and mutagenic effects of certain alkylating agents. The major effector molecule regulating this response is the 39-kDa Ada protein, which functions as both a DNA repair protein and a transcriptional activator. Ada removes methyl groups from phosphotriester and ...
Lin D - - 1994
Overexpression of wild-type p53 protein has been shown to induce arrest in the G1 stage of the cell cycle and to transactivate expression of the gene that encodes the 21-kDa Waf1/Cip1 protein, a potent inhibitor of cyclin-dependent kinase activity. p53-dependent G1 arrest is accompanied by decreased expression of the B-myb ...
Kamano H - - 1994
In order to elucidate the role of c-myb gene in erythroid differentiation of K562 cell induced by hemin (Hm) and erythropoietin (Epo), we constructed recombinant plasmid that could produce antisense myb RNA after induction with dexamethasone. During treatment with Hm, K562 cells constitutively expressed c-myb mRNA, and 50% of them ...
Melotti P - - 1994
The CD34 antigen defines a subset of hematopoietic progenitor cells with self-renewal capacity and the ability to reconstitute hematopoiesis in irradiated primates and marrow-ablated humans, but its function remains unknown. The c-myb protooncogene plays a fundamental role in hematopoiesis, most likely via its transcriptional regulator function. We report that c-myb ...
Lam E W - - 1994
HPV16 is a human tumour virus encoding two principal oncoproteins, E6 and E7. Expression of E7 can induce DNA synthesis in quiescent cells and this property coincides with its ability to bind to the cell proteins pRb and p107. As these cell proteins are regulators of the transcription factor E2F, ...
Hernandez-Munain C - - 1994
A T-cell-specific transcriptional enhancer lies within the J delta 3-C delta intron of the human T-cell receptor (TCR) delta gene. The 30-bp minimal enhancer element denoted delta E3 carries a core sequence (TGTGGTTT) that binds a T-cell-specific factor, and that is necessary but not sufficient for transcriptional activation. Here we ...
Piacentini M - - 1994
The c-myb transcriptional regulator plays a crucial role in the control of several proliferative/differentiative processes in haematopoietic cells. Its expression and function is not lineage-restricted, since c-myb is also expressed in solid tumours such as neuroblastomas, where its transcription is decreased by retinoic acid. In response to retinoic acid, neuroblastomas ...
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