Search results for "Gene Expression"
showing 10 items of 4085 documents
The effect of hormone replacement therapy on Ca2+ mobilization and P-selectin (CD62P) expression in platelets examined under flow cytometry.
2004
A series of events, such as increase of cytoplasmic free calcium (Ca 2+ ) and expression of P-selectin (CD62P), an adhesion molecule, on the platelet surface, are significant indicators of platelet activation. We have used flow cytometry to examine Ca 2+ mobilization and CD62P expression in platelets in whole blood obtained in women prior to, and after, different forms of hormone replacement therapy. Thirty-two women completed a protocol consisting of two consecutive 1-month periods under oestradlol (E 2 ), administered orally (2 mg/day) or transdermally (50 μg/day) in random order, followed by a 4-week transdermal sequential regime, in which, during the last 14 days, either progesterone (3…
DNA methylation and histone acetylation of rat methionine adenosyltransferase 1A and 2A genes is tissue-specific.
2000
Methionine adenosyltransferase (MAT) catalyzes the biosynthesis of S-adenosylmethionine (AdoMet). In mammals MAT activity derives from two separate genes which display a tissue-specific pattern of expression. While MAT1A is expressed only in the adult liver, MAT2A is expressed in non-hepatic tissues. The mechanisms behind the selective expression of these two genes are not fully understood. In the present report we have evaluated MAT1A and MAT2A methylation in liver and in other tissues, such as kidney, by methylation-sensitive restriction enzyme digestion of genomic DNA. Our data indicate that MAT1A is hypomethylated in liver and hypermethylated in non-expressing tissues. The opposite situ…
Differentiative pathway activated by 3-aminobenzamide, an inhibitor of PARP, in human osteosarcoma MG-63 cells
2004
AbstractThis study describes the molecular mechanism by which treatment with 3-AB, a potent inhibitor of PARP, allows human osteosarcoma MG-63 cells to restrict growth and enter differentiation. Our findings show that in MG-63 cells, aberrant gene expression keeps Rb protein constitutively inactivated through hyperphosphorylation and this promotes uncontrolled proliferation of the cells. After 3-AB-treatment, the poly(ADP-ribosyl)ation of nuclear proteins markedly decreases and this results in an increase in both the hypophosphorylated active form of Rb and pRb/E2F complexes. These effects are accompanied by G1 arrest, downregulation of gene products required for proliferation (cyclin D1, β…
The transcriptional programme of contact-inhibition.
2010
Proliferation of non-transformed cells is regulated by cell-cell contacts, which are referred to as contact-inhibition. Vice versa, transformed cells are characterised by a loss of contact-inhibition. Despite its generally accepted importance for cell-cycle control, little is known about the intracellular signalling pathways involved in contact-inhibition. Unravelling the molecular mechanisms of contact-inhibition and its loss during tumourigenesis will be an important step towards the identification of novel target genes in tumour diagnosis and treatment. To better understand the underlying molecular mechanisms we identified the transcriptional programme of contact-inhibition in NIH3T3 fib…
ABG1 , a Novel and Essential Candida albicans Gene Encoding a Vacuolar Protein Involved in Cytokinesis and Hyphal Branching
2005
ABSTRACT Immunoscreening of a Candida albicans expression library resulted in the isolation of a novel gene encoding a 32.9-kDa polypeptide (288 amino acids), with 27.7% homology to the product of Saccharomyces cerevisiae YGR106c, a putative vacuolar protein. Heterozygous mutants in this gene displayed an a ltered b udding g rowth pattern, characterized by the formation of chains of buds, decreasingly in size towards the apex, without separation of the daughter buds. Consequently, this gene was designated ABG1 . A conditional mutant for ABG1 with the remaining allele under the control of the MET3 promoter did not grow in the presence of methionine and cysteine, demonstrating that ABG1 was e…
The down-regulation of miR-125b in chronic lymphocytic leukemias leads to metabolic adaptation of cells to a transformed state
2012
AbstractMiR-125b-1 maps at 11q24, a chromosomal region close to the epicenter of 11q23 deletions in chronic lymphocytic leukemias (CLLs). Our results establish that both aggressive and indolent CLL patients show reduced expression of miR-125b. Overexpression of miR-125b in CLL-derived cell lines resulted in the repression of many transcripts encoding enzymes implicated in cell metabolism. Metabolomics analyses showed that miR-125b overexpression modulated glucose, glutathione, lipid, and glycerolipid metabolism. Changes on the same metabolic pathways also were observed in CLLs. We furthermore analyzed the expression of some of miR-125b–target transcripts that are potentially involved in the…
Altered expression of nonclassical HLA class Ib antigens in human renal cell carcinoma and its association with impaired immune response
2003
Abstract An optimal antitumoral immune response requires the activation of both CD8 + and CD4 + T lymphocytes by the peptide antigen presentation via the human leukocyte antigen (HLA) class I and class II molecules, respectively. Downregulation or loss of HLA molecules has been found in human renal cell carcinoma (RCC) and provides a strategy of these tumors to evade T-cell mediated immunosurveillance. In addition, a tumor-specific upregulation of HLA-G has been recently described in RCC, which also leads to an impaired immune response. We here summarize the frequency of the constitutive and/or interferon-γ (IFN-γ) inducible expression of nonclassical HLA class Ib antigens in RCC cell lines…
Overexpression of bone morphogenetic protein-6 (BMP-6) in the epidermis of transgenic mice: inhibition or stimulation of proliferation depending on t…
1996
Bone morphogenetic protein-6 (BMP-6) belongs to the family of TGF-beta-related growth factors. In the developing epidermis, expression of BMP-6 coincides with the onset of stratification. Expression persists perinatally but declines after day 6 postpartum, although it can still be detected in adult skin by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. We constitutively overexpressed BMP-6 in suprabasal layers of interfollicular epidermis in transgenic mice using a keratin 10 promoter. All mice expressing the transgene developed abnormalities in the skin, indicating an active transgene-derived factor. Depending on the pattern of transgene expression, the effects on proli…
Distribution of Cartilage Proteoglycan (Aggrecan) Core Protein and Link Protein Gene Expression during Human Skeletal Development
1991
The distribution of cartilage proteoglycan core protein (aggrecan) and cartilage proteoglycan link protein was investigated by in situ hybridization during different stages of human skeletal development. Aggrecan and link protein expression were confined to chondrocytes of the developing skeleton and other cartilaginous structures. Distribution and intensity of the signal was identical with aggrecan as compared to link protein probes. Parallel to the calcification of cartilaginous matrix, chondrocytes of this area lost the expression of aggrecan and link protein specific mRNA and stayed negative throughout the following stages of skeletal development. Highest expression was found in the low…
miR-29b negatively regulates human osteoclastic cell differentiation and function: Implications for the treatment of multiple myeloma-related bone di…
2013
Skeletal homeostasis relies upon a fine tuning of osteoclast (OCLs)-mediated bone resorption and osteoblast (OBLs)-dependent bone formation. This balance is unsettled by multiple myeloma (MM) cells, which impair OBL function and stimulate OCLs to generate lytic lesions. Emerging experimental evidence is disclosing a key regulatory role of microRNAs (miRNAs) in the regulation of bone homeostasis suggesting the miRNA network as potential novel target for the treatment of MM-related bone disease. Here, we report that miR-29b expression decreases progressively during human OCL differentiation in vitro. We found that lentiviral transduction of miR-29b into OCLs, even in the presence of MM cells,…