Recent ucri_crcc_rw items

Scalable Total Synthesis, IP3R Inhibitory Activity ofDesmethylxestospongin B, and Effect on Mitochondrial Function andCancer Cell Survival

Tue, 11 Jul 2023 00:00:00 +0000

Scalable Total Synthesis, IP3R Inhibitory Activity ofDesmethylxestospongin B, and Effect on Mitochondrial Function andCancer Cell Survival

Asymmetric dimerization of adenosine deaminase acting on RNA facilitates substrate recognition.

Fri, 20 Nov 2020 00:00:00 +0000

Adenosine deaminases acting on RNA (ADARs) are enzymes that convert adenosine to inosine in duplex RNA, a modification that exhibits a multitude of effects on RNA structure and function. Recent studies have identified ADAR1 as a potential cancer therapeutic target. ADARs are also important in the development of directed RNA editing therapeutics. A comprehensive understanding of the molecular mechanism of the ADAR reaction will advance efforts to develop ADAR inhibitors and new tools for directed RNA editing. Here we report the X-ray crystal structure of a fragment of human ADAR2 comprising its deaminase domain and double stranded RNA binding domain 2 (dsRBD2) bound to an RNA duplex as an asymmetric homodimer. We identified a highly conserved ADAR dimerization interface and validated the importance of these sequence elements on dimer formation via gel mobility shift assays and size exclusion chromatography. We also show that mutation in the dimerization interface inhibits editing...

A DNA aptamer for binding and inhibition of DNA methyltransferase 1.

Wed, 29 Jan 2020 00:00:00 +0000

DNA methyltransferases (DNMTs) are enzymes responsible for establishing and maintaining DNA methylation in cells. DNMT inhibition is actively pursued in cancer treatment, dominantly through the formation of irreversible covalent complexes between small molecular compounds and DNMTs that suffers from low efficacy and high cytotoxicity, as well as no selectivity towards different DNMTs. Herein, we discover aptamers against the maintenance DNA methyltransferase, DNMT1, by coupling Asymmetrical Flow Field-Flow Fractionation (AF4) with Systematic Evolution of Ligands by EXponential enrichment (SELEX). One of the identified aptamers, Apt. #9, contains a stem-loop structure, and can displace the hemi-methylated DNA duplex, the native substrate of DNMT1, off the protein on sub-micromolar scale, leading for effective enzymatic inhibition. Apt. #9 shows no inhibition nor binding activity towards two de novo DNMTs, DNMT3A and DNMT3B. Intriguingly, it can enter cancer cells with over-expression...

Rapid Enrichment and Detection of Extracellular Vesicles Enabled by CuS-Enclosed Microgels.

Wed, 29 Jan 2020 00:00:00 +0000

Extracellular vesicles (EVs) are cell-derived membranous vesicles that exist in nearly all biological fluids, including blood and urine; and carry a great number of cargo molecules such as protein, nucleic acids, and lipid. They may play important roles in cell-cell communication and modulation of pathological processes, which, however, are not yet well understood, calling for highly sensitive, specific, and rapid methods for EV detection and quantification in biological samples. Here, we report the CuS-enclosed microgels that not only help enrich EVs carrying specific protein markers from complex biomatrices, but also produce strong chemiluminescence (CL) to realize sensitive detection of the target EVs. A detection limit of 10⁴ EV particles/mL was achieved with these microgels by targeting EV proteins like CD63 and HER2, with a dynamic range up to 10⁸ particles/mL. Direct detection of EVs in human serum and cell culture medium without tedious sample...

Metabolite Responsive Nanoparticle-Protein Complex

Mon, 30 Sep 2019 00:00:00 +0000

Stimuli responsive polymers are an efficient means of targeted therapy. Compared to conventional agents, they increase bioavailability and efficacy. In particular, polymer hydrogel nanoparticles (NPs) can be designed to respond when exposed to a specific environmental stimulus such as pH or temperature. However, targeting a specific metabolite as the trigger for stimuli response could further elevate selectivity and create a new class of bioresponsive materials. In this work we describe an N-isopropylacrylamide (NIPAm) NP that responds to a specific metabolite characteristic of a hypoxic environment found in cancerous tumors. NIPAm NPs were synthesized by copolymerization with an oxamate derivative, a known inhibitor of lactate dehydrogenase (LDH). The oxamate functionalized NPs (OxNP) efficiently sequestered LDH to produce an OxNP-protein complex. When exposed to elevated concentrations of lactic acid, a substrate of LDH and a...

Investigations into Wnt modulation of p27(KIP1) turnover and the E3 ligase substrate adaptor DDB1 and CUL4 Associated Factor 4

Thu, 8 Mar 2018 00:00:00 +0000

Investigations into Wnt modulation of p27(KIP1) turnover and the E3 ligase substrate adaptor DDB1 and CUL4 Associated Factor 4

Regulation of the T-box transcription factor Tbx3 by the tumour suppressor microRNA-206 in breast cancer

Wed, 31 May 2017 00:00:00 +0000

Background:

The Tbx3 transcription factor is over-expressed in breast cancer, where it has been implicated in proliferation, migration and regulation of the cancer stem cell population. The mechanisms that regulate Tbx3 expression in cancer have not been fully explored. In this study, we demonstrate that Tbx3 is repressed by the tumour suppressor miR-206 in breast cancer cells.

Methods:

Bioinformatics prediction programmes and luciferase reporter assays were used to demonstrate that miR-206 negatively regulates Tbx3. We examined the impact of miR-206 on Tbx3 expression in breast cancer cells using miR-206 mimic and inhibitor. Gene/protein expression was examined by quantitative reverse-transcription–PCR and immunoblotting. The effects of miR-206 and Tbx3 on apoptosis, proliferation, invasion and cancer stem cell population was investigated by cell-death detection, colony formation, 3D-Matrigel and tumorsphere assays.

Results:

In this study, we examined the regulation...

Pre-clinical development of gene modification of hematopoietic stem cells with chimeric antigen receptors for cancer immunotherapy

Mon, 17 Apr 2017 00:00:00 +0000

Pre-clinical development of gene modification of hematopoietic stem cells with chimeric antigen receptors for cancer immunotherapy

Oil-in-Water-in-Oil Multinanoemulsions for Templating Complex Nanoparticles

Mon, 17 Apr 2017 00:00:00 +0000

Oil-in-Water-in-Oil Multinanoemulsions for Templating Complex Nanoparticles

Adenosine A2a receptors form distinct oligomers in protein detergent complexes

Thu, 3 Nov 2016 00:00:00 +0000

Adenosine A2a receptors form distinct oligomers in protein detergent complexes

Structure and function of G protein-coupled receptor oligomers: implications for drug discovery

Thu, 3 Nov 2016 00:00:00 +0000

Structure and function of G protein-coupled receptor oligomers: implications for drug discovery

Erythrocyte-derived nano-probes functionalized with antibodies for targeted near infrared fluorescence imaging of cancer cells

Fri, 12 Aug 2016 00:00:00 +0000

Constructs derived from mammalian cells are emerging as a new generation of nano-scale platforms for clinical imaging applications. Herein, we report successful engineering of hybrid nano-structures composed of erythrocyte-derived membranes doped with FDA-approved near infrared (NIR) chromophore, indocyanine green (ICG), and surface-functionalized with antibodies to achieve molecular targeting. We demonstrate that these constructs can be used for targeted imaging of cancer cells in vitro. These erythrocyte-derived optical nano-probes may provide a potential platform for clinical translation, and enable molecular imaging of cancer biomarkers.

Syrbactin Structural Analog TIR-199 Blocks Proteasome Activity And Induces Tumor Cell Death.

Fri, 22 Apr 2016 00:00:00 +0000

Multiple myeloma (MM) is an aggressive hematopoietic cancer of plasma cells. The recent emergence of three effective FDA-approved proteasome-inhibiting drugs, bortezomib (Velcade), carfilzomib (Kyprolis), and ixazomib (Ninlaro) confirms that proteasome inhibitors are therapeutically useful against neoplastic disease, in particular refractory MM and mantle cell lymphoma. This study describes the synthesis, computational affinity assessment, and preclinical evaluation of TIR-199, a natural product-derived syrbactin structural analog. Molecular modeling and simulation suggested TIR-199 covalently binds each of the three catalytic subunits (β1, β2 and β5) and revealed key interaction sites. In vitro and cell culture-based proteasome activity measurements confirmed that TIR-199 inhibits the proteasome in a dose-dependent manner and induces tumor cell death in multiple myeloma and neuroblastoma cells as well as other cancer types in the NCI-60 cell panel. It is particularly effective...

Copy number networks to guide combinatorial therapy of cancer and proliferative disorders

Thu, 17 Dec 2015 00:00:00 +0000

Interaction networks can be charted by seeking gene pairs that are amplified and/or deleted in tandem, even when located at a distance on the genome. Our experience with radiation hybrid (RH) panels, a library of cell clones that have been used for genetic mapping, have shown this tool can pinpoint statistically significant patterns of co-inherited gene pairs. In fact, we were able to identify gene pairs specifically associated with the mechanism of cell survival at single gene resolution. Further, the RH network can be used to provide single gene specificity for cancer networks constructed from correlated copy number alterations (CNAs). In a survival network for glioblastoma, we found that the epidermal growth factor receptor (EGFR) oncogene interacted with 46 genes. Of these genes, ten (22%) happened to be targets for existing drugs. Here, we highlight the potential of CNA networks to guide combinatorial drug treatment in cancer, autoimmunity and atherosclerosis.

Automatic Small RNA Extraction and Processing by a Multichannel/Multiwell Chip

Thu, 10 Dec 2015 00:00:00 +0000

Automatic Small RNA Extraction and Processing by a Multichannel/Multiwell Chip