Search results for "Cell line"
showing 10 items of 2924 documents
Fitness Trade-Offs Determine the Role of the Molecular Chaperonin GroEL in Buffering Mutations
2015
Molecular chaperones fold many proteins and their mutated versions in a cell and can sometimes buffer the phenotypic effect of mutations that affect protein folding. Unanswered questions about this buffering include the nature of its mechanism, its influence on the genetic variation of a population, the fitness trade-offs constraining this mechanism, and its role in expediting evolution. Answering these questions is fundamental to understand the contribution of buffering to increase genetic variation and ecological diversification. Here, we performed experimental evolution, genome resequencing, and computational analyses to determine the trade-offs and evolutionary trajectories of Escherich…
Pore-forming toxins activate MAPK p38 by causing loss of cellular potassium.
2009
Mitogen activated protein kinase (MAPK) p38 has emerged as a survival protein in cells that are attacked by bacterial toxins forming small membrane pores. Activation of p38 by pore forming toxins (PFT) has been attributed to osmotic stress, but here we show that loss of K+ is likely to be the critical parameter. Several lines of evidence support this conclusion: first, osmoprotection did not prevent p38-phosphorylation in alpha-toxin-loaded cells. Second, treatment of cells with a K+ ionophore, or simple incubation in K+-free medium sufficed to cause robust p38-phosphorylation. Third, media containing high [K+] prevented p38-activation by Staphylococcus aureus alpha-toxin, Vibrio cholerae c…
Evidence for a direct interaction of Rev protein with nuclear envelop mRNA-translocation system.
1991
The interaction of the Rev protein from human immunodeficiency virus type 1 (HIV-1) with the nucleocytoplasmic mRNA-transport system was investigated. In gel-shift assay, the recombinant Rev protein used in this study selectively bound to the Rev-responsive element (RRE) region of HIV-1 env-specific RNA. Nitrocellulose-filter-binding studies and Northern/Western-blotting experiments revealed an association constant of approximately 1 x 10(10) M-1. The Rev protein also strongly bound to isolated nuclear envelopes from H9 cells, containing the poly(A)-binding site (= mRNA carrier) and the nucleoside triphosphatase (= NTPase), which are thought to be involved in nuclear export of poly(A)-rich …
A new method to isolate microglia from adult mice and culture them for an extended period of time
2009
As the major immuno-competent cells of the brain, microglia are highly implicated in neuro-protection as well as in neurodegeneration. Therefore, they are of key interest for research on numerous CNS diseases. Currently, to model inflammation in the brain, microglial cell lines or primary microglia prepared from embryonic or neo-natal rodents are widely used. However, these in vitro microglial models are not suitable for research in the field of neuro-degenerative diseases where aging is a crucial parameter. Only a few in vitro studies on aged microglia have been published so far, most of which use ex vivo microglia which cannot be kept in culture for prolonged periods of time. In the prese…
Functional characterization of two melanocortin (MC) receptors in lamprey showing orthology to the MC1 and MC4 receptor subtypes
2007
Abstract Background The melanocortin (MC) receptors have a key role in regulating body weight and pigmentation. They belong to the rhodopsin family of G protein-coupled receptors (GPCRs). The purpose of this study was to identify ancestral MC receptors in agnathan, river lamprey. Results We report cloning of two MC receptors from river lamprey. The lamprey receptors, designated MCa and MCb, showed orthology to the MC1 and MC4 receptor subtypes, respectively. The molecular clock analysis suggested that lamprey MC receptor genes were not duplicated recently and diverged from each other more than 400 MYR ago. Expression and pharmacological characterization showed that the lamprey MCa receptor …
Cytotoxicity and apoptosis induction by Fumaria officinalis extracts in leukemia and multiple myeloma cell lines
2021
Abstract Ethnopharmacological relevance Fumaria officinalis (Fumariaceae) is recorded in the Kurdish ethnobotany for various health problems. Aim of the study: In this study, the cytotoxic activity of F. officinalis extracts on two leukemia and nine multiple myeloma (MM) cell lines was investigated. Materials and methods: The cytotoxic and ferroptotic activity were examined by resazurin reduction assay. Flow cytometry, immunoblotting assay and fluorescence microscopy were used to measure cell cycle distribution, apoptosis, induction of reactive oxygen species (ROS), loss integrity of mitochondrial membrane potential (MMP) and autophagy. LC-ESI/MS was used to identify chemical constituents p…
Met inhibition revokes IFNγ-induction of PD-1 ligands in MET-amplified tumours
2019
BACKGROUND: Interferon-induced expression of programmed cell death ligands (PD-L1/PD-L2) may sustain tumour immuneevasion. Patients featuring MET amplification, a genetic lesion driving transformation, may benefit from anti-MET treatment. We explored if MET-targeted therapy interferes with Interferon-gamma modulation of PD-L1/PD-L2 in MET-amplified tumours.METHODS: PD-L1/PD-L2 expression and signalling pathways downstream of MET or Interferon-gamma were analysed in MET-amplified tumour cell lines and in patient-derived tumour organoids, in basal condition, upon Interferon-gamma stimulation, and after anti-MET therapy.RESULTS: PD-L1 and PD-L2 were upregulated in MET-amplified tumour cells up…
The abrogation of the HOXB7/PBX2 complex induces apoptosis in melanoma through the miR-221&222-c-FOS pathway.
2013
Cutaneous melanoma is the fastest increasing cancer worldwide. Although several molecular abnormalities have been associated with melanoma progression, the underlying mechanisms are still largely unknown and few targeted therapies are under evaluation. Here we show that the HOXB7/PBX2 dimer acts as a positive transcriptional regulator of the oncogenic microRNA-221 and -222. In addition, demonstrating c-FOS as a direct target of miR-221&222, we identify a HOXB7/PBX2→miR-221&222 →c-FOS regulatory link, whereby the abrogation of functional HOXB7/PBX2 dimers leads to reduced miR-221&222 transcription and elevated c-FOS expression with consequent cell death. Taking advantage of the treatment wit…
Antitumor effects of dehydroxymethylepoxyquinomicin, a novel nuclear factor-kappaB inhibitor, in human liver cancer cells are mediated through a reac…
2009
Activation of the nuclear transcription factor-kappa B (NF-kappa B) has been implicated in liver tumorigenesis. We evaluated the effects of a novel NF-kappa B inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ), in two human liver cancer cell lines HA22T/VGH and HuH-6. DHMEQ treatment dose dependently decreased the DNA-binding capacity of the NF-kappa B p65 subunit, inhibited cell growth and proliferation, and increased apoptosis as shown by caspase activation, release of cytochrome c, poly(ADP-ribose) polymerase cleavage, and down-regulation of survivin. DHMEQ also induced a dose-dependent activation of mitogen-activated protein kinase kinase/extracellular signal-regulated kinase signaling, …
COX-2-dependent and COX-2-independent mode of action of celecoxib in human liver cancer cells.
2011
Celecoxib (Celebrex((R)), Pfizer) is a selective cyclooxygenase-2 (COX-2) inhibitor with chemopreventive and antitumor effects. However, it is now well known that celecoxib has several COX-2-independent activities. To better understand COX-2-independent molecular mechanisms underlying the antitumor activity of celecoxib, we investigated the expression profile of the celecoxib-treated COX-2-positive (Huh7) and COX-2-negative (HepG2) liver cancer cell lines, using microarray analysis. Celecoxib treatment resulted in significantly altered expression levels of 240 and 403 transcripts in Huh7 and HepG2 cells, respectively. Confirmation of the microarray results was performed for selected genes b…