Search results for "Assays"
showing 10 items of 546 documents
Combined inhibition of Bcl-2 and NFκB synergistically induces cell death in cutaneous T-cell lymphoma.
2019
Abstract Therapeutic options for cutaneous T-cell lymphoma (CTCL) are limited and curative treatment regimens are not available. Thus, new targeted and well-tolerated therapeutic approaches are urgently needed. In this respect, we have recently shown that dimethyl fumerate (DMF) inhibits NF-κB acting as a survival factor in CTCL. Similarly, inhibition of the antiapoptotic protein B-cell lymphoma 2 (Bcl-2) has been shown to induce cell death in CTCL especially when combined with histone deacetylase inhibitors. Therefore, we hypothesized that inhibition of Bcl-2 should potentiate NF-κB inhibition in a novel combination treatment of CTCL. We show that, in vitro, the Bcl-2 inhibitors ABT-199 an…
Identification of Plakortide E from the Caribbean Sponge Plakortis halichondroides as a Trypanocidal Protease Inhibitor using Bioactivity-Guided Frac…
2014
In this paper, we report new protease inhibitory activity of plakortide E towards cathepsins and cathepsin-like parasitic proteases. We further report on its anti-parasitic activity against Trypanosoma brucei with an IC50 value of 5 mu M and without cytotoxic effects against J774.1 macrophages at 100 mu M concentration. Plakortide E was isolated from the sponge Plakortis halichondroides using enzyme assay-guided fractionation and identified by NMR spectroscopy and mass spectrometry. Furthermore, enzyme kinetic studies confirmed plakortide E as a non-competitive, slowly-binding, reversible inhibitor of rhodesain.
Development of Novel Selective Peptidomimetics Containing a Boronic Acid Moiety, Targeting the 20S Proteasome as Anticancer Agents
2014
This paper describes the design, synthesis, and biological evaluation of peptidomimetic boronates as inhibitors of the 20S proteasome, a validated target in the treatment of multiple myeloma. The synthesized compounds showed a good inhibitory profile against the ChT-L activity of 20S proteasome. Compounds bearing a β-alanine residue at the P2 position were the most active, that is, 3-ethylphenylamino and 4-methoxyphenylamino (R)-1-{3-[4-(substituted)-2-oxopyridin-1(2H)-yl]propanamido}-3-methylbutylboronic acids (3 c and 3 d, respectively), and these derivatives showed inhibition constants (Ki ) of 17 and 20 nM, respectively. In addition, they co-inhibited post glutamyl peptide hydrolase act…
Assessing the low complexity of protein sequences via the low complexity triangle.
2020
Background Proteins with low complexity regions (LCRs) have atypical sequence and structural features. Their amino acid composition varies from the expected, determined proteome-wise, and they do not follow the rules of structural folding that prevail in globular regions. One way to characterize these regions is by assessing the repeatability of a sequence, that is, calculating the local propensity of a region to be part of a repeat. Results We combine two local measures of low complexity, repeatability (using the RES algorithm) and fraction of the most frequent amino acid, to evaluate different proteomes, datasets of protein regions with specific features, and individual cases of proteins…
Reading the Evolution of Compartmentalization in the Ribosome Assembly Toolbox: The YRG Protein Family.
2016
Reconstructing the transition from a single compartment bacterium to a highly compartmentalized eukaryotic cell is one of the most studied problems of evolutionary cell biology. However, timing and details of the establishment of compartmentalization are unclear and difficult to assess. Here, we propose the use of molecular markers specific to cellular compartments to set up a framework to advance the understanding of this complex intracellular process. Specifically, we use a protein family related to ribosome biogenesis, YRG (YlqF related GTPases), whose evolution is linked to the establishment of cellular compartments, leveraging the current genomic data. We analyzed orthologous proteins …
Integrative genomic and proteomic analyses identify targets for Lkb1 deficient metastatic lung tumors
2010
SummaryIn mice, Lkb1 deletion and activation of KrasG12D results in lung tumors with a high penetrance of lymph node and distant metastases. We analyzed these primary and metastatic de novo lung cancers with integrated genomic and proteomic profiles, and have identified gene and phosphoprotein signatures associated with Lkb1 loss and progression to invasive and metastatic lung tumors. These studies revealed that SRC is activated in Lkb1-deficient primary and metastatic lung tumors, and that the combined inhibition of SRC, PI3K, and MEK1/2 resulted in synergistic tumor regression. These studies demonstrate that integrated genomic and proteomic analyses can be used to identify signaling pathw…
Missing value imputation in proximity extension assay-based targeted proteomics data
2020
Targeted proteomics utilizing antibody-based proximity extension assays provides sensitive and highly specific quantifications of plasma protein levels. Multivariate analysis of this data is hampered by frequent missing values (random or left censored), calling for imputation approaches. While appropriate missing-value imputation methods exist, benchmarks of their performance in targeted proteomics data are lacking. Here, we assessed the performance of two methods for imputation of values missing completely at random, the previously top-benchmarked ‘missForest’ and the recently published ‘GSimp’ method. Evaluation was accomplished by comparing imputed with remeasured relative concentrations…
ErbB-3 activation by NRG-1β sustains growth and promotes vemurafenib resistance in BRAF-V600E colon cancer stem cells (CSCs)
2015
Approximately 5-10% of metastatic colorectal cancers harbor a BRAF-V600E mutation, which is correlated with resistance to EGFR-targeted therapies and worse clinical outcome. Vice versa, targeted inhibition of BRAF-V600E with the selective inhibitor PLX 4032 (Vemurafenib) is severely limited due to feedback re-activation of EGFR in these tumors. Mounting evidence indicates that upregulation of the ErbB-3 signaling axis may occur in response to several targeted therapeutics, including Vemurafenib, and NRG-1β-dependent re-activation of the PI3K/AKT survival pathway has been associated with therapy resistance. Here we show that colon CSCs express, next to EGFR and ErbB-2, also significant amoun…
Theileria parasites secrete a prolyl isomerase to maintain host leukocyte transformation
2015
Infectious agents develop intricate mechanisms to interact with host cell pathways and hijack their genetic and epigenetic machinery to change host cell phenotypic states. Among the Apicomplexa phylum of obligate intracellular parasites, which cause veterinary and human diseases, Theileria is the only genus that transforms its mammalian host cells. Theileria infection of bovine leukocytes induces proliferative and invasive phenotypes associated with activated signalling pathways, notably JNK and AP-1 (ref. 2). The transformed phenotypes are reversed by treatment with the theilericidal drug buparvaquone. We used comparative genomics to identify a homologue of the peptidyl-prolyl isomerase PI…
Novel ruthenium methylcyclopentadienyl complex bearing a bipyridine perfluorinated ligand shows strong activity towards colorectal cancer cells
2017
Three new compounds have been synthesized and completely characterized by analytical and spectroscopic techniques. The new bipyridine-perfluorinated ligand L1 and the new organometallic complex [Ru(η 5 -MeCp)(PPh 3 ) 2 Cl] (Ru1) crystalize in the centrosymmetric triclinic space group P1¯. Analysis of the phenotypic effects induced by both organometallic complexes Ru1 and [Ru(η 5 -MeCp)(PPh 3 )(L1)][CF 3 SO 3 ] (Ru2), on human colorectal cancer cells (SW480 and RKO) survival, showed that Ru2 has a potent anti-proliferative activity, 4–6 times higher than cisplatin, and induce apoptosis in these cells. Data obtained in a noncancerous cell line derived from normal colon epithelial cells (NCM46…