Search results for "TUMOR CELLS"

Cloning of a novel putative G-protein-coupled receptor (NLR) which is expressed in neuronal and lymphatic tissue.

1993

AbstractA novel G-protein-coupled receptor was isolated from mouse and rat neuronal and lymphatic tissues. The amino acid sequence of the rat receptor (rNLR) shows an overall homology of 80% to a recently cloned receptor from Burkitt's lymphoma cells (BLR1) which is exclusively expressed in lymphatic tissues [(1992) Eur. J. Immunol. 22, 2795]. Much less homology between rNLR and BLR1 was observed at the N-terminus (about 40%), whereas rNLR and the mouse homologue mNLR show 92% amino acid identity. Northern blot analysis of NLR revealed a predominant 5.5 kb mRNA species in various brain regions and neuronal cell lines, whereas in the spleen a 3 kb transcript is predominant. This distribution…

Cytoplasmic STAT proteins associate prior to activation

2000

The commonly accepted model of STAT factor activation at the cytoplasmic part of the receptor assumes that signal transducers and activators of transcription (STATs) are recruited from a cytoplasmic pool of monomeric STAT proteins. Based on a previous observation that non-phosphorylated STAT3-Src homology 2 domains dimerize in vitro, we investigated whether the observed dimerization is of physiological relevance within the cellular context. We show that STAT1 and STAT3 are pre-associated in non-stimulated cells. Apparently, these complexes are not able to translocate into the nucleus. We provide evidence that the event of STAT activation is more complex than previously assumed.

Squaraine Dyes for Photodynamic Therapy: Study of Their Cytotoxicity and Genotoxicity in Bacteria and Mammalian Cells¶‡

2007

Halogenated squaraine dyes are characterized by long wavelength absorption (>600 nm) and high triplet yields and therefore represent new types of photosensitizers that could be useful for photodynamic therapy. We have analyzed the cytotoxicity and genotoxicity of the bromo derivative 1, the iodo derivative 2 and the corresponding nonhalogenated dye 3 in the absence and presence of visible light. At concentrations of 1-2 microM, 1 and 2 reduced the cloning efficiency of AS52 Chinese hamster ovary cells to less than 1% under conditions that were well tolerated in the dark. Similarly, the proliferation of L5178Y mouse lymphoma cells was inhibited by photoexcited 1 and 2 with high selectivity. …

Enterobacteria-infected T cells as antigen-presenting cells for cytotoxic CD8 T cells: a contribution to the self-limitation of cellular immune react…

1997

In enterobacteria-induced reactive arthritis (ReA), different T cell subsets play a role in the induction and maintenance of the synovitic process. Synovial fluid-derived alphabeta CD4, alphabeta CD8, and gammadelta T lymphocyte clones (TLC) that recognize Yersinia or Salmonella antigens on professional antigen-presenting cells (APC) have been characterized, and T cells themselves can function as nonprofessional APC. T cells were infected with the facultatively intracellular, arthritogenic enterobacterium Yersinia enterocolitica O:3. A CD8 TLC isolated from a patient with Yersinia-induced ReA recognized and efficiently lysed autologous and allogeneic Yersinia-infected T cells. Infected cyto…

Heteroaromatic Inhibitors of the Astacin Proteinases Meprin α, Meprin β and Ovastacin Discovered by a Scaffold-Hopping Approach.

2020

Abstract Astacin metalloproteinases, in particular meprins α and β, as well as ovastacin, are emerging drug targets. Drug‐discovery efforts have led to the development of the first potent and selective inhibitors in the last few years. However, the most recent compounds are based on a highly flexible tertiary amine scaffold that could cause metabolic liabilities or decreased potency due to the entropic penalty upon binding to the target. Thus, the aim of this study was to discover novel conformationally constrained scaffolds as starting points for further inhibitor optimization. Shifting from flexible tertiary amines to rigid heteroaromatic cores resulted in a boost in inhibitory activity. …

DNA damage causes TP53-dependent coupling of self-renewal and senescence pathways in embryonal carcinoma cells.

2013

Recent studies have highlighted an apparently paradoxical link between self-renewal and senescence triggered by DNA damage in certain cell types. In addition, the finding that TP53 can suppress senescence has caused a re-evaluation of its functional role in regulating these outcomes. To investigate these phenomena and their relationship to pluripotency and senescence, we examined the response of the TP53-competent embryonal carcinoma (EC) cell line PA-1 to etoposide-induced DNA damage. Nuclear POU5F1/OCT4A and P21CIP1 were upregulated in the same cells following etoposide-induced G 2M arrest. However, while accumulating in the karyosol, the amount of OCT4A was reduced in the chromatin fract…

Inhibition of FcεRI-mediated Activation of Rat Basophilic Leukemia Cells by Clostridium difficile Toxin B (Monoglucosyltransferase)

1996

Abstract Treatment of rat basophilic leukemia (RBL) 2H3-hm1 cells with Clostridium difficile toxin B (2 ng/ml), which reportedly depolymerizes the actin cytoskeleton, blocked [3H]serotonin release induced by 2,4-dinitrophenyl-bovine serum albumin, carbachol, mastoparan, and reduced ionophore A23187-stimulated degranulation by about 55-60%. In lysates of RBL cells, toxin B 14C-glucosylated two major and one minor protein. By using two-dimensional gel electrophoresis and immunoblotting, RhoA and Cdc42 were identified as protein substrates of toxin B. In contrast to toxin B, Clostridium botulinum transferase C3 that selectively inactivates RhoA by ADP-ribosylation did not inhibit degranulation…

Telomerase activity and telomeric states in cell proliferative and differentiative mechanisms.

2008

Telomeres are DNA-protein complexes playing an important role in the maintenance of genome integrity. Telomerase is the enzyme acting as a template for addition of new telomeric repeats; this addition is essential for those cellular populations that have proliferative and differentiative potential. Telomerase and associated proteins are essential in response to DNA damage. Moreover, telomere-associated proteins as TRF2 are involved in all signalling transduction pathway which drive cellular proliferation and differentiation. In somatic cells, shortening of telomeres contributes to the onset of senescence or apoptosis; tissues which require cellular renewal express telomerase activity in ord…

DNMT1 SILENCING ELICITS DIFFERENT CELL CYCLE RESPONSES IN PRIMARY VERSUS TUMOR CELLS AND IS ASSOCIATED WITH ANEUPLOIDY GENERATION

2011

Significance of Autologous Interleukin-6 Production in the HA22T/VGH Cell Model of Hepatocellular Carcinoma

2006

Cancer cells may often support their own growth, survival, and drug resistance by autocrine/paracrine loops based on the production of different factors; results from us and others have shown that similar interleukin-6 (IL-6)-related loops are operative in multiple myeloma and prostate or renal cancer. Because this aspect has not been investigated in detail for hepatocellular carcinoma (HCC), we have examined it in HA22T/VGH cells. These differ from other primary liver cancer cell lines (that is, HepG2, HuH-6, and HuH-7) in that enzyme-linked immunosorbent assay (ELISA) showed the HA22T/VGH cells to secrete remarkable amounts of IL-6 (16.8 ng/10(6) cells/24 h); this production, due to const…