Search results for "VITRO"
showing 10 items of 2786 documents
Holo-APP and G-protein-mediated signaling are required for sAPPa-induced activation of the Akt survival pathway
2014
International audience; Accumulating evidence indicates that loss of physiologic amyloid precursor protein (APP) function leads to reduced neuronal plasticity, diminished synaptic signaling and enhanced susceptibility of neurons to cellular stress during brain aging. Here we investigated the neuroprotective function of the soluble APP ectodomain sAPPa (soluble APPa), which is generated by cleavage of APP by a-secretase along the non-amyloidogenic pathway. Recombinant sAPPa protected primary hippocampal neurons and SH-SY5Y neuroblastoma cells from cell death induced by trophic factor deprivation. We show that this protective effect is abrogated in neurons from APP-knockout animals and APP-de…
Biological response of multicellular emt6 spheroids to exogenous lactate
1991
The influence of elevated lactate concentrations, as found in tumor microregions, on cellular growth, viability, and metabolic state was studied employing the multicellular spheroid model. Spheroids of EMT6/Ro cells were cultured at 37 degrees C in 5% or 20% (v/v) oxygen, using stirred media with various concentrations of exogenous lactate ranging from 0.0 mM (standard conditions) to 20.0 mM. Elevated concentrations of exogenous lactate led to a considerable decrease of the maximum spheroid diameter at growth saturation, e.g., for 20% O2 from around 1700 microns to 700 microns in 0.0 and 20.0 mM lactate respectively. Histological investigations showed that the thickness of the viable cell r…
Abstract 1993: Fishing for artemisinin-interacting proteins from human nasopharyngeal cancer cells
2012
Abstract Determining cellular target molecules of drugs by chemical proteomic techniques is complex and tedious. Most approaches rely on activity-based probe profiling and compound-centric chemical proteomics. The antimalarial artemisinin also exerts profound anti-cancer activity, but the mechanisms of action are incompletely understood. In the present study, we have identified artemisinin-interacting target proteins from human nasopharyngeal carcinoma cell line CNE1. Thereby, our approach overcomes usual problems in traditional fishing procedures, because the drug was attached to a polystyrene surface without further chemical modification. Using mass spectrometry we have identified 20 prot…
Impaired HLA-class-I stability in a sarcoma cell line which stimulates exclusively HLA-class-II-restricted autologous T cells
1996
Defects in the generation and transport of antigenic peptides within tumor cells will lead to the expression of unstable HLA-class-I molecules on the cell surface. These defects will allow tumor cells to escape an MHC-class-I-restricted T-cell response. Recently, we described an exclusively HLA-class-II-restricted autologous T-cell response against a human sarcoma cell line MZ-MES-1 in vitro. Here, we show that surface HLA-class-I molecules of MZ-MES-1 cells are unstable at physiological temperature. HLA-class-I surface expression of MZ-MES-1 cells could be strongly enhanced by culture at low temperature in contrast to various other cell lines analyzed in parallel. Furthermore, culture at l…
Abstract 1138: The protein disulfide isomerase inhibitor XCE853 inhibits in vitro, ex-vivo and in vivo growth of human tumors
2017
Abstract Protein disulfide isomerase (PDI) is a chaperone protein that regulates oxidative protein folding as well as cell viability. Increased PDI levels have been documented in a variety of human cancers associated with a poor overall survival, including ovarian, prostate, brain and lung cancers. Inhibition of PDI activity leads to apoptosis in cancer, suggesting that PDI is a promising druggable target. XCE853 is a synthetic small molecule displaying an excellent docking with the catalytic domain of the human PDI. XCE853 inhibits in vitro recombinant PDI enzymatic activity. In addition, the proliferation of a large panel of human tumor cells is blocked by XCE853 with IC50s in the nanomol…
Transcriptomic responses generated by hepatocarcinogens in a battery of liver-based in vitro models
2013
As the conventional approach to assess the potential of a chemical to cause cancer in humans still includes the 2-year rodent carcinogenicity bioassay, development of alternative methodologies is needed. In the present study, the transcriptomics responses following exposure to genotoxic (GTX) and non-genotoxic (NGTX) hepatocarcinogens and non-carcinogens (NC) in five liver-based in vitro models, namely conventional and epigenetically stabilized cultures of primary rat hepatocytes, the human hepatoma-derived cell lines HepaRG and HepG2 and human embryonic stem cell-derived hepatocyte-like cells, are examined. For full characterization of the systems, several bioinformatics approaches are emp…
Cancer stem cell definitions and terminology:the devil is in the details
2012
The cancer stem cell (CSC) concept has important therapeutic implications, but its investigation has been hampered both by a lack of consistency in the terms used for these cells and by how they are defined. Evidence of their heterogeneous origins, frequencies and their genomic, as well as their phenotypic and functional, properties has added to the confusion and has fuelled new ideas and controversies. Participants in The Year 2011 Working Conference on CSCs met to review these issues and to propose a conceptual and practical framework for CSC terminology. More precise reporting of the parameters that are used to identify CSCs and to attribute responses to them is also recommended as key t…
Stable expression of rat cytochrome P450IA2 cDNA and hydroxylation of 17β-estradiol and 2-aminofluorene in V79 Chinese hamster cells
1991
In continuation of our work toward the establishment of a working cell bank for metabolic and toxicological studies, V79 Chinese hamster cells were genetically engineered for stable expression of rat cytochrome P450IA2. Full-length cDNA encoding rat P450IA2 was obtained by searching a cDNA library made from Aroclor 1254-induced rat liver mRNA and by joining a small 5'-end fragment to a fragment containing the rest of the cDNA. The sequence of the cDNA was confirmed by DNA sequencing and comparison to a previously published cDNA sequence. The reconstructed full-length cDNA was inserted into a simian virus 40 early promoter-containing eukaryotic expression vector and cotransferred with the ne…
A new assay for O6-alkylguanine-DNA-alkyltransferase to determine DNA repair capacities using lambda-phage DNA as substrate.
1990
One O6-methylguanine (O6-meG) was introduced into each BamHI site of lambda-phage DNA as a substrate for the determination of the DNA repair protein O6-alkylguanine-DNA-alkyltransferase. A new assay using as the detection group 32P-labeled phosphate introduced at the 3' position of the modified nucleoside by incorporation of 32P-labeled TTP in the 3'-neighboring position proved highly sensitive: 10(-16) mol of the DNA lesion was still easily detectable. This DNA, which has greater than 1000 bp represents a good model for cellular DNA and was used as a substrate to measure the individual repair capacities for O6-meG in human lymphocytes of 20 healthy male and female donors. There were great …
Development and in vitro evaluation of new bifunctional 89Zr-chelators based on the 6-amino-1,4-diazepane scaffold for immuno-PET applications
2021
Abstract Introduction Combination of hydroxamate bearing side chains with the 6-amino-1,4-diazepane scaffold provides a promising strategy for fast and stable 89Zr-labeling of antibodies. Following this approach, we hereby present the development, labeling kinetics and in vitro complex stability of three resulting bifunctional chelator derivatives both stand-alone and coupled to a model protein in comparison to different linear deferoxamine (DFO) derivatives. Methods The novel 89Zr-chelator Hy3ADA5 was prepared via amide-coupling of separately synthesized 6-amino-1,4-diazepane-6-pentanoic acid and hydroxamate-containing side chains. Two further bifunctional derivatives were synthesized by e…