Search results for "Transform"
showing 10 items of 3975 documents
A novel SP-1 site in the human interleukin-1β promoter confers preferential transcriptional activity in keratinocytes
1996
To investigate the mechanisms of transcriptional activation of interleukin-1beta (IL-1beta) in non-monocytic cells, we constructed a series of reporter plasmids with the bacterial chloramphenicol acetyltransferase gene linked to various parts of the human IL-1beta promoter and performed transient transfection experiments. We identified a promoter segment that activates transcription most efficiently in keratinocytes. Electrophoretic mobility shift assays (EMSA) with a 43-mer oligonucleotide derived from the functionally identified cis-acting element revealed specific complexes. By competition analysis with transcription factor consensus sequence oligonucleotides and by immunosupershift, tra…
Colon Cancer Stem Cells: Promise of Targeted Therapy
2010
First developed for hematologic disorders, the concept of cancer stem cells (CSCs) was expanded to solid tumors, including colorectal cancer (CRC). The traditional model of colon carcinogenesis includes several steps that occur via mutational activation of oncogenes and inactivation of tumor suppressor genes. Intestinal epithelial cells exist for a shorter amount of time than that required to accumulate tumor-inducing genetic changes, so researchers have investigated the concept that CRC arises from the long-lived stem cells, rather than from the differentiated epithelial cells. Colon CSCs were originally identified through the expression of the CD133 glycoprotein using an antibody directed…
Inulin-Ethylenediamine Coated SPIONs Magnetoplexes: A Promising Tool for Improving siRNA Delivery.
2015
An inulin based polycation (Inu-EDA) has been synthesized by the grafting of ethylenediamine molecules onto inulin backbone. The obtained inulin copolymer has been though to coat SPIONs (IC-SPIONs) and obtain stable magnetoplexes by complexation of IC-SPIONs with a model duplexed siRNA, for improving oligonucleotide transfection efficiency.The physical-chemical characteristics of IC-SPIONs and IC-SPIONs/siRNA magnetoplexes have been investigated by scanning and transmission electron microscopies, dynamic light scattering, FT-IR and qualitative surface elementary analysis. Cell compatibility and internalization in vitro of IC-SPIONs have been evaluated by MTS and fluorescence microscopy resp…
[Post-translational regulation of N-glycosylated proteins expression in human intestinal cells in culture].
1991
International audience; HT-29 cells derived from a human colonic adenocarcinoma, can express a typical intestinal differentiation. Undifferentiated HT-29 cells accumulate N-linked glycoproteins substituted with unprocessed carbohydrate chains before to degrade them. Conversely, carbohydrate chains of N-linked glycoproteins are classically processed in differentiated HT-29 cells. The instability of N-linked glycoproteins in undifferentiated HT-29 cells is due to their rapid delivery from the endoplasmic reticulum to a compartment with lysosomal characteristics. This catabolitic pathway involves a bypass of the Golgi apparatus.
Down-regulation of nuclear binding activities of OXBOX-REBOX transcription factors during cellular senescence.
1996
Functional capacity of mitochondria declines during aging and this impairment may have a major role in aging process. Several observations indicate that transcriptional efficiency is reduced during aging. Our purpose was to find out whether aging and cellular senescence affect the nuclear binding activities of transcription factors which bind to OXBOX-REBOX sequence present in promoter regions of numerous nuclear genes encoding mitochondrial proteins. These factors regulate and coordinate the expression of mitochondrial proteins. We observed a strong down-regulation in the nuclear binding activities of OXBOX-REBOX factors in replicatively senesced human WI-38 and IMR-90 fibroblasts. On the …
Proliferative activity and tumorigenic conversion: impact on cellular metabolism in 3-D culture
2001
Oxygen consumption, glucose, lactate, and ATP concentrations, as well as glucose and lactate turnover rates, have been studied in a three-dimensional carcinogenesis model of differently transformed rat embryo fibroblasts (spontaneously immortalized Rat1 and myc-transfected M1, and the ras-transfected, tumorigenic descendants Rat1-T1 and MR1) to determine metabolic alterations that accompany tumorigenic conversion. Various bioluminescence techniques, thymidine labeling, measurement of[Formula: see text] distributions with microelectrodes, and determination of cellular oxygen uptake rates (Q˙[Formula: see text]) have been applied. In the ras-transfected, tumorigenic spheroid types, the size d…
Differential regulation of the clusterin gene by Ha-ras and c-myc oncogenes and during apoptosis
1998
Clusterin (ApoJ) is an extracellular glycoprotein expressed during processes of tissue differentiation and regression that involve programmed cell death (apoptosis). Increased clusterin expression has also been found in tumors, however, the mechanism underlying this induction is not known. Apoptotic processes in tumors could be responsible for clusterin gene activation. Alternatively, oncogenic mutations could modulate signal transduction, thereby inducing the gene. We examined the response of the rat clusterin gene to two oncogenes, Ha-ras and c-myc, in transfected Rat1 fibroblasts. While c-myc overexpression did not modify clusterin gene activity, the Ha-ras oncogene produced a seven to t…
A specific CD4 epitope bound by tregalizumab mediates activation of regulatory T cells by a unique signaling pathway
2014
CD4(+)CD25(+) regulatory T cells (Tregs) represent a specialized subpopulation of T cells, which are essential for maintaining peripheral tolerance and preventing autoimmunity. The immunomodulatory effects of Tregs depend on their activation status. Here we show that, in contrast to conventional anti-CD4 monoclonal antibodies (mAbs), the humanized CD4-specific monoclonal antibody tregalizumab (BT-061) is able to selectively activate the suppressive properties of Tregs in vitro. BT-061 activates Tregs by binding to CD4 and activation of signaling downstream pathways. The specific functionality of BT-061 may be explained by the recognition of a unique, conformational epitope on domain 2 of th…
TGF-β superfamily signaling is essential for tooth and hair morphogenesis and differentiation
2007
Members of the transforming growth factor beta (TGF-beta) superfamily of signaling molecules are involved in the regulation of many developmental processes that involve the interaction between mesenchymal and epithelial tissues. Smad7 is a potent inhibitor of many members of the TGF-beta family, notably TGF-beta and activin. In this study, we show that embryonic overexpression of Smad7 in stratified epithelia using a keratin 5 promoter, results in severe morphogenetic defects in skin and teeth and leads to embryonic and perinatal lethality. To further analyze the functions of Smad7 in epithelial tissues of adult mice, we used an expression system that allowed a controlled overexpression of …
Alternative splicing products of the tenascin gene distinguish rat liver fat storing cells from arterial smooth muscle cells and skin fibroblasts
1992
Abstract Fat storing-(Ito-)cells (FSC) transform into a myofibroblast-like cell type during liver fibrogenesis. A similar development can be observed in cell culture. At the moment, a definite marker to differentiate transformed FSC from smooth muscle cells (SMC) is not available. We recently found that FSC, SMC and skin fibroblasts (SF) synthesize tenascin, a novel matrix protein. As it is reported that various tissues express different tenascin forms by the mechanism of alternative pre-mRNA splicing, we analyzed the tenascin transcripts in these cell types. Total RNA extracted from cultured FSC, SMC and SF, analyzed by Northern blot hybridization, showed a 7.2 kb transcript in FSC, a 8.7 …