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Results 601 - 650 of 857
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Lei Qun-Ying - - 2002
The relationship between PTEN expression and anoikis in 8 different human lung carcinoma cell (HLCC) lines, and PKB and FAK effects in the process were studied. Northern blots and Western blots were carried out to analyze PTEN expression at mRNA and protein levels and the phosphorylation level of PKB /FAK ...
Kitajima Kenji - - 2002
GATA-2 is a zinc finger transcription factor essential for the development of hematopoiesis. While GATA-2 is generally considered to play an important role in the biology of hematopoietic stem and progenitor cells, its function within these compartments is not well understood. Here we have employed both conditional expression of GATA-2 ...
Anderson Michele K - - 2002
PU.1 and GATA-3 are transcription factors that are required for development of T cell progenitors from the earliest stages. Neither one is a simple positive regulator for T lineage specification, however. When expressed at elevated levels at early stages of T cell development, each of these transcription factors blocks T ...
Monticelli Silvia - - 2002
Cytokine-dependent induction of correctly spliced germline (GL) transcripts is required to target the appropriate switch region for class switch recombination. GL transcription is linked to the cell cycle and the number of cell divisions through mechanisms that have not been defined. The human proximal epsilon GL promoter contains an IL-4 ...
Li Xiaolin - - 2002
The B-Myb transcription factor has been implicated in coordinating the expression of genes involved in cell cycle regulation. Although it is expressed in a ubiquitous manner, its transcriptional activity is repressed until the G(1)-S phase of the cell cycle by an unknown mechanism. In this study we used biochemical and ...
Tanno Barbara - - 2002
Neuroblastoma (NB), a malignant childhood tumor deriving from the embryonic neural crest, is sensitive to the growth-stimulating effects of insulin-like growth factors (IGFs). Aggressive cases of this disease often acquire autocrine loops of IGF production, but the mechanisms through which the different components of the IGF axis are regulated in ...
Wan X - - 2002
Staurosporine is a potent apoptosis inducer, but its mechanism remains to be clarified. We investigated the involvement of PTEN in staurosporine-induced apoptosis. Ishikawa cells, from an endometrial carcinoma cell line, expressed a high amount of PTEN mRNA but did not express the PTEN protein because of protein truncations. We isolated ...
Schmidt-Weber Carsten B - - 2002
The phosphatidylinositol phosphatase gene PTEN is a dual specific phosphatase acting on phospho amino acids but also on three phosphorylated inositol phospholipids. Present results demonstrate that PTEN is inducible by costimulatory signals in human CD4(+) T cells. PTEN expression was up-regulated on RNA and protein level in freshly isolated human ...
Chen Jing - - 2002
Friend murine erythroleukemia (MEL) cells are transformed erythroid precursors that are held in an immature and proliferating state but can be induced to differentiate in vivo by treatment with a variety of chemical agents such as N, N-hexamethylene bisacetamide (HMBA). To investigate the role of Myb proteins in maintaining MEL ...
Wang Duen-Mei - - 2002
A minimal transcription activation domain of the v-Myb oncoprotein was initially mapped to a central cluster of charged residues using GAL4-Myb fusion proteins. This region has been proposed to interact directly with the CBP co-activator in animal cells. Regions flanking this central domain of v-Myb are required for transcriptional activation ...
Perkel Jeffrey M - - 2002
Expression of the c-myb proto-oncogene is developmentally regulated at the level of transcription elongation. In pre-B cells, complete c-myb transcripts are produced, whereas transcripts are attenuated near or within a 300-base pair (bp) interval of the first c-myb intron in mature cells. Hypothesizing that transcription attenuation results from a protein ...
Mårtensson A - - 2001
The lambda5 gene is expressed exclusively in precursor (pre-) B cells where its gene product, as part of the pre-B cell receptor, is crucial for the proliferation of these cells. Several DNA regions regulate the activity and expression pattern of the lambda5 gene. Amongst these is an enhancer, B(lambda5), located ...
Nicot C - - 2001
The proto-oncogene c-myb is essential for a controlled balance between cell growth and differentiation. Aberrant c-Myb activity has been reported for numerous human cancers, and enforced c-Myb transcription can transform cells of lymphoid origin by stimulating cellular proliferation and inhibiting apoptotic pathways. Here we demonstrate that activation of the NF-kappaB ...
Reizis B - - 2001
The expression of the pre-T cell receptor alpha (pTa) gene occurs exclusively in immature T lymphocytes and is regulated by poorly defined mechanisms. We have analyzed the role of the upstream enhancer in pTa expression using conventional and bacterial artificial chromosome (BAC) reporter transgenes. The deletion of the enhancer completely ...
Masselink H - - 2001
B-myb, a ubiquitously expressed member of the myb gene family, is highly regulated throughout the cell cycle and appears to be required for cell cycle progression. In contrast to its relatives A-myb, c-myb, and v-myb, no transforming activity of B-myb has been reported thus far. We report here that B-myb ...
Schmidt M - - 2001
Deregulated expression of the proto-oncogene c-myb, which results from provirus integration, is thought to be responsible for transformation in a set of murine leukemia virus (MuLV)-induced myeloid leukemias (MML). We reported recently that this transcription factor promotes proliferation by directly transactivating c-myc and inhibits cell death through its up-regulation of ...
Huang H - - 2001
The tumor suppressor gene PTEN (MMAC1/TEP1) is lost frequently in advanced prostate cancer (PCa). However, the function of PTEN in tumorigenesis is not understood fully. In this study, we demonstrate that expression of Bcl-2 in prostate tumors correlates with loss of the PTEN protein. This finding was verified by studies ...
Brabender J - - 2001
BACKGROUND: Esophageal adenocarcinoma develops through a multistage process which is characterized histopathologically by progression from Barrett's intestinal metaplasia to Barrett's esophagus with dysplasia and ultimately to adenocarcinoma. The genetic basis of this process is increasingly well understood, but no studies have examined the role of the transcription factor c-myb in ...
Yang S - - 2001
Two cDNA clones (NtmybAS1 and NtmybAS2) encoding MYB-related proteins with strong sequence similarity to petunia (Petunia hybrida) PhMYB3 were isolated from a tobacco (Nicotiana tabacum cv Samsun) pollen cDNA library. Northern blot and in situ hybridization revealed that NtmybAS transcripts are specifically expressed in both sporophytic and gametophytic tissues of ...
Yang H - - 2001
Liver-specific and non-liver-specific methionine adenosyltransferase (MAT) are products of two genes, MAT1A and MAT2A, respectively, that catalyze the formation of S-adenosylmethionine. We showed a switch from MAT1A to MAT2A expression at the transcriptional level in human hepatocellular carcinoma (HCC) that facilitates cancer cell growth. The purpose of the present study ...
Hemm M R - - 2001
Mounting evidence indicates that members of the large family of plant MYB proteins are involved in the transcriptional regulation of an array of metabolic and developmental processes. Recently, the Arabidopsis thaliana MYB, AtMYB4, was shown to regulate the accumulation of the UV-protectant compound sinapoylmalate by repressing the transcription of the ...
Müller-Tidow C - - 2001
Cyclin A1 is tissue-specifically expressed during spermatogenesis, but it is also highly expressed in acute myeloid leukemia (AML). Its pathogenetic role in AML and in the cell cycle of leukemic blasts is unknown. B-myb is essential for G1/S transition and has been shown to be phosphorylated by the cyclin A2/cdk2 ...
Gilleard J S - - 2001
The Caenorhabditis elegans GATA transcription factor genes elt-1 and elt-3 are expressed in the embryonic hypodermis (also called the epidermis). elt-1 is expressed in precursor cells and is essential for the production of most hypodermal cells (22). elt-3 is expressed in all of the major hypodermal cells except the lateral ...
Tanikawa J - - 2001
Heat shock proteins (HSPs) act as chaperones and play important roles during cellular proliferation and apoptosis. Heat shock factors (HSFs) mediate transcriptional induction of HSP genes. Among multiple heat shock transcription factors (HSFs) in vertebrates, HSF3 is specifically activated in unstressed proliferating cells by direct binding to the c-myb proto-oncogene ...
Shin D H - - 2001
In this study, we demonstrated the c-myb mRNA expression in the adult rat brain using an in situ hybridization technique. We found c-myb mRNA signals in the various regions of the forebrain and midbrain including the cerebral cortex, thalamus, hippocampus, hypothalamus, superior and inferior colliculi and central gray. In the ...
Alzogaray R A - - 2001
The hyperactivity (an increase in locomotor activity) and repellency produced by eight pyrethroids, applied as films on filter paper, were evaluated on fifth instar nymphs of Triatoma infestans (Hemiptera: Reduviidae) using a video tracking technique. All the pyrethroids studied produced hyperactivity. As a trend, hyperactivity produced by cyanopyrethroids was higher ...
Raschellà G - - 2001
BACKGROUND: The expression of several genes is modulated during neuroblastoma differentiation. The retinoblastoma family proteins, pRb, p107 and pRb2/p130, act in the repression of proliferation genes, interacting mainly with the E2F transcription factors. PROCEDURE AND RESULTS: In this study, we found that, in neuroblastoma cell lines, pRb and p107 proteins ...
Zeng Z - - 2001
Methionine adenosyltransferase (MAT) is a critical cellular enzyme which catalyses the formation of S-adenosylmethionine (SAM), the principal methyl donor. In mammals, two different genes, MAT1A and MAT2A, encode liver-specific and non-liver-specific MATs, respectively. SAM level increases during T-lymphocyte activation and is required for proliferation. A major mechanism for the increase ...
Jayaraman P S - - 2000
Haematopoiesis involves the differentiation of a self-renewing stem cell into all of the lineages found in circulating blood. Myb-Ets transformed chicken blastoderm cells (MEPs) have many of the characteristics of multipotent haematopoietic cells and represent a useful model system for the study of haematopoiesis. The proline-rich homeodomain protein (PRH) has ...
Horstmann S - - 2000
B-Myb is a highly conserved member of the Myb transcription factor family. The primary transcript of the B-myb gene is spliced alternatively in two mRNAs which either contain or lack a sequence corresponding to the so-called exon 9A of c-myb. Recent studies showed that full-length B-Myb containing the exon 9A ...
Pearson R - - 2000
Transgenic mice expressing a T-cell-specific dominant interfering allele (MEnT) of the c-Myb transcription factor have a pronounced block in CD4(-)CD8(-) (DN) development. In this study we show that differentiation of DN MEnT thymocytes is blocked due to the failure of cells to enter the cell cycle following beta-selection, the process ...
Krystal G - - 2000
In the last 10 years we have come to appreciate the central role that phosphatidylinositol (PI)-3,4,5-P(3)plays in regulating a vast array of biological responses to extracellular signals. The level of this phospholipid is low in resting cells but increases rapidly in response to growth factor/cytokine-stimulated plasma membrane recruitment and activation ...
Cervellera M - - 2000
B-MYB is a ubiquitously expressed transcription factor involved in the regulation of cell survival, proliferation, and differentiation. In an attempt to isolate B-MYB-regulated genes that may explain the role of B-MYB in cellular processes, representational difference analysis was performed in neuroblastoma cell lines with different levels of B-MYB expression. One ...
Fernández de Mattos S - - 2000
Previous studies have demonstrated that the F isoform of<hsp sp=0.5>6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase(6PF2K/Fru-2,6-BPase) is transcriptionally regulated by growth factors. The aim of this study was to investigate the importance of the phosphatidylinositol 3-kinase (PI 3-kinase) pathway in the regulation of 6PF2K/Fru-2,6-BPase gene expression. We have completed studies using chemical inhibitors and expression vectors ...
Yokoyama Y - - 2000
PTEN is a tumor suppressor gene and its mutation is frequently found in endometrial carcinoma. Recently, the pseudogene of PTEN has been reported to be actively transcribed in a number of cells and tissues and a potential for translation is suggested. For further understanding of the involvement of PTEN in ...
Auger K R - - 2000
The discovery that the PTEN tumor suppressor encodes a phosphoinositide 3-phosphatase has raised interest in the effects of constitutive activation of PI 3-kinase. To gain insight into PI 3-kinase function, we have stably expressed a myristoylated form of the catalytic subunit p110alpha (myr-p110) in cells. The myr-p110 associated with the ...
Charrasse S - - 2000
B-Myb, a highly conserved member of the Myb oncoprotein family, is a 110 kDa sequence-specific DNA binding protein expressed in virtually all proliferating cells. B-myb expression reaches its maximum at the G1/S phase boundary and during the S phase of the cell cycle. We have previously shown that B-Myb activity ...
Ward A C - - 2000
The development of mature granulocytes from hematopoietic precursor cells is controlled by a myriad of transcription factors which regulate the expression of essential genes, including those encoding growth factors and their receptors, enzymes, adhesion molecules, and transcription factors themselves. In particular, C/EBPalpha, PU.1, CBF, and c-Myb have emerged as critical ...
Mutter G L - - 2000
Frequent mutation of the PTEN tumor suppressor gene in endometrial adenocarcinoma has led to the prediction that its product, a phosphatase that regulates the cell cycle, apoptosis, and possibly cell adhesion, is functionally active within normal endometrial tissues. We examined PTEN expression in normal human endometrium during response to changing ...
Ohya S - - 2000
Diverse expression of voltage dependent K+ (Kv) channels was examined in smooth muscles (SMs); carotid artery (CA), mesenteric artery (MA), urinary bladder (UB), and vas deferens (VD) of the rat, using RT-PCR based analyses. Among eight Kv channel subtypes examined (Kv 1.1, Kv 1.2, Kv 1.5, Kv 1.6, Kv 2.1, ...
Tanikawa J - - 2000
Expression of heat shock proteins (HSPs) is controlled by heat shock transcription factors (HSFs). Vertebrates express multiple HSFs whose activities may be regulated by distinct signals. HSF3 is specifically activated in unstressed proliferating cells by direct binding to the c-myb proto-oncogene product (c-Myb), which plays an important role in cellular ...
O'Brien G J - - 2000
The rotavirus major inner capsid protein (VP6) has been expressed in Nicotiana benthamiana plants using vectors based on potato virus X (PVX). VP6 was expressed either as a fusion with the PVX coat protein or from an additional subgenomic promoter inserted to enable both VP6 and PVX coat protein to ...
Manzella L - - 2000
The preferential expression of the protooncogene c-myb in hematopoietic cells is in part regulated by a mechanism of transcriptional block in the first intron. By electrophoresis mobility shift assays using probes corresponding to different segments of the putative human c-myb intron 1 transcription pause region and nuclear extracts from myeloid ...
Ramsay R G - - 2000
Cyclooxygenase-2 (COX-2) is an important pharmacological target with great promise in the prevention and treatment of colorectal cancer (CRC). The mechanism underlying COX-2 overexpression in CRC is unresolved. On the basis of the coincident high levels of the transcription factor c-MYB and COX-2 in CRC, we hypothesized that c-MYB is ...
Zhong H - - 2000
Dysregulated signal transduction from receptor tyrosine kinases to phosphatidylinositol 3-kinase (PI3K), AKT (protein kinase B), and its effector FKBP-rapamycin-associated protein (FRAP) occurs via autocrine stimulation or inactivation of the tumor suppressor PTEN in many cancers. Here we demonstrate that in human prostate cancer cells, basal-, growth factor-, and mitogen-induced expression ...
Heckman C A - - 2000
In follicular lymphoma, bcl-2 is translocated to the immunoglobulin heavy chain locus leading to deregulation of bcl-2 expression. We examined the role of Myb proteins in the regulation of bcl-2 expression in lymphoma cells. We showed that A-Myb up-regulates bcl-2 promoter activity. Northern and Western analyses demonstrated that A-Myb was ...
Schmidt M - - 2000
c-myb is a frequent target of retroviral insertional mutagenesis in murine leukemia virus-induced myeloid leukemia. Induction of the leukemogenic phenotype is generally associated with inappropriate expression of this transcriptional regulator. Despite intensive investigations, the target genes of c-myb that are specifically involved in development of these myeloid lineage neoplasms are ...
Buck M - - 2000
Expression of alpha-smooth muscle actin (alpha-SMA) defines the phenotype of activated (myofibroblastic) hepatic stellate cells. These cells, but not quiescent stellate cells, have a high level of alpha-SMA and c-Myb expression, as well as increased c-Myb-binding activities to the proximal alpha-SMA E box. Therefore, we analyzed the role of c-Myb ...
Yuan W - - 2000
Previous studies have shown that expression of steady-state c-myb mRNA was regulated primarily by a block in intron 1 during transcription elongation. This study shows that the block site maps approximately 1700 bp from the start of the intron. Studies based on a reporter construct containing c-myb flanking region and ...
Engelhard A - - 2000
The human B-myb gene encodes a cell cycle-regulated DNA-binding phosphoprotein which functions as a transcription factor with an important role in cell cycle progression, survival, and differentiation. Recently, it has been demonstrated that ectopic murine B-myb expression blocked the ability of 32Dcl3 cells to proliferate in response to granulocyte colony-stimulating ...
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