Search results for "Tumor cell"
showing 10 items of 694 documents
SKRINING FITOKIMIA, UJI AKTIVITAS ANTIMIKROBA DAN ANTITUMOR TUMBUHAN OBAT KABUPATEN MANOKWARI
2008
<p><em>Pythochemistry screening and testing of antimicrobial and antitumor activities was carried out on 31 species of medicinal plants distributed around Manokwari Regency. All parts of the plants were collected and screened for the presence of alkaloids, saponins, and tannins; antimicrobial and antitumor activity. The number of positive tests obtained are 17 (55, 3%) for alkaloids, 6 (19, 4%) for saponins, and 26 (84, 7%) for tannins. Eleven species shown inhibition activities (antimicrobial) to Candida albicans, Staphyloccocus aureus, and Echericia colii while only seven species have antitumor activity, especially against tumor cell P-388. </em></p>
Expression of Bax, a pro-apoptotic member of the Bcl-2 family, in esophageal squamous cell carcinoma
1997
Samples of normal esophageal squamous epithelium (n = 10), severe squamous cell dyplasia (n = 22), carcinoma in situ (n = 15), invasive squamous cell carcinoma (n = 172), lymph-node metastasis (n = 21) and 2 permanent esophageal squamous cell carcinoma cell lines were analyzed immunohistochemically for Bax expression using a polyclonal anti-Bax antibody. Immunostaining was evaluated according to a score system (0–8 points) based on the percentage of positive tumor cells and the relative immunostaining intensity. Cytoplasmatic staining for Bax protein was found uniformly in all cell layers of the normal esophageal squamous epithelium. In contrast, a gradual loss of immunoreactivity for Bax w…
Alternative Polyadenylation Events Contribute to the Induction of NF-ATc in Effector T Cells
1999
Abstract The transcription factor NF-ATc is synthesized in three prominent isoforms. These differ in the length of their C terminal peptides and mode of synthesis. Due to a switch from the use of a 3′ polyA site to a more proximal polyA site, NF-ATc expression switches from the synthesis of the two longer isoforms in naive T cells to that of short isoform A in T effector cells. The relative low binding affinity of cleavage stimulation factor CstF-64 to the proximal polyA site seems to contribute to its neglect in naive T cells. These alternative polyadenylation events ensure the rapid accumulation of high concentrations of NF-ATc necessary to exceed critical threshold levels of NF-ATc for g…
A brief guide to performing pharmacological studies in vitro: Reflections from the EORTC-PAMM Course “Preclinical and Early-phase Clinical Pharmacolo…
2019
One aim of cell-based in vitro assays is to identify the best drug candidate to develop using the best tumor cell model. This is challenging in every anticancer drug discovery process. Briefly, we summarize the parameters to be taken into account when performing in vitro cell assays, in order to obtain reliable and reproducible results, which was fundamentally discussed by lecturers at the educational course on preclinical and early-phase clinical pharmacology studies, at the 40th Winter Meeting of the Pharmacology and Molecular Mechanisms Group of the European Organization for Research and Treatment of Cancer. Moreover, specific cellular sensitivity tests are described. In addition to mono…
Photolysis of N-hydroxpyridinethiones: a new source of hydroxyl radicals for the direct damage of cell-free and cellular DNA.
1996
N-Hydroxypyridine-2-thione (2-HPT), known to release hydroxyl radicals on irradiation with visible light, and two related compounds, viz. N-hydroxypyridine-4-thione (4-HPT) and N-hydroxyacridine-9-thione (HAT), were tested for their potency to induce DNA damage in L1210 mouse leukemia cells and in isolated DNA from bacteriophage PM2. DNA single-strand breaks and modifications sensitive to various repair endonucleases (Fpg protein, endonuclease III, exonuclease III, T4 endonuclease V) were quantified. Illumination of cell-free DNA in the presence of 2-HPT and 4-HPT gave rise to damage profiles characteristic for hydroxyl radicals, i.e. single-strand breaks and the various endonuclease-sensit…
Delivery of proteins into living cells by reversible membrane permeabilization with streptolysin-O
2001
The pore-forming toxin streptolysin O (SLO) can be used to reversibly permeabilize adherent and nonadherent cells, allowing delivery of molecules with up to 100 kDa mass to the cytosol. Using FITC-labeled albumin, 10 5 –10 6 molecules were estimated to be entrapped per cell. Repair of toxin lesions depended on Ca 2+ -calmodulin and on intact microtubules, but was not sensitive to actin disruption or to inhibition of protein synthesis. Resealed cells were viable for days and retained the capacity to endocytose and to proliferate. The active domains of large clostridial toxins were introduced into three different cell lines. The domains were derived from Clostridium difficile B-toxin and Clo…
Transcriptional profiling of circulating tumor cells in multiple myeloma: a new model to understand disease dissemination
2020
The reason why a few myeloma cells egress from the bone marrow (BM) into peripheral blood (PB) remains unknown. Here, we investigated molecular hallmarks of circulating tumor cells (CTCs) to identify the events leading to myeloma trafficking into the bloodstream. After using next-generation flow to isolate matched CTCs and BM tumor cells from 32 patients, we found high correlation in gene expression at single-cell and bulk levels (r ≥ 0.94, P = 10−16), with only 55 genes differentially expressed between CTCs and BM tumor cells. CTCs overexpressed genes involved in inflammation, hypoxia, or epithelial–mesenchymal transition, whereas genes related with proliferation were downregulated in CTCs…
Platelet-derived growth factor alpha mediates the proliferation of peripheral T-cell lymphoma cells via an autocrine regulatory pathway.
2014
Peripheral T-cell lymphomas not otherwise specified (PTCL/NOS) are very aggressive tumors characterized by consistent aberrant expression of platelet-derived growth factor receptor alpha (PDGFRA). In this study, we aimed to identify the determinants of PDGFRA activity in PTCL/NOS and to elucidate the biological consequences of its activation. We observed overexpression of the PDGFRA gene by gene expression profiling in most of the tested PTCLs and confirmed the expression of PDGFRA and phospho-PDGFRA using immunohistochemistry. The integrity of the PDFGRA locus was demonstrated using several different approaches, including massive parallel sequencing and Sanger sequencing. PDGF-AA was found…
Regulation of cell-to-cell communication in non-tumorigenic and malignant human prostate epithelial cells.
2002
BACKGROUND Gap-junction-mediated intercellular communication (GJIC) is required for normal development and tissue homeostasis. However, the role of GJIC in human prostate carcinogenesis and progression remains ill-defined. METHODS The ability of hormones, anti-hormones, and the anti-hypertensive drug, forskolin, to restore GJIC in non-tumorigenic (RWPE-1 and PWR-1E) and malignant (RWPE-2, LNCaP, DU-145) human prostate epithelial cell lines, was examined by Scrape-Loading/Dye Transfer (SL/DT) and Fluorescence Recovery After Photobleaching (FRAP) methods using an Ultima laser cytometer. RESULTS Results from both assays show that PWR-1E, RWPE-2, LNCaP, and DU-145 cells have weak or absent GJIC…
Retinoic Acid Induces Apoptosis-Associated Neural Differentiation of a Murine Teratocarcinoma Cell Line
2002
Abstract: Incubation with all-trans retinoic acid (RA) induces PCC7-Mz1 embryonic carcinoma cells to cease proliferation and to develop into a tissue-like pattern of neuronal, astroglial, and fibroblast-like derivatives over a period of several days. Concomitant with the induction of differentiation by RA, a sizable fraction of the Mz1 stem cells detaches and dies, with the maximal level of cell death achieved after 10 h of RA treatment. This RA-induced cell death fulfills all criteria of apoptosis, including nuclear condensation, intranucleosomal DNA degradation, expression of cysteine aspases (caspases), and the formation of apoptotic bodies. Apoptosis could be suppressed by the pan-caspa…