Publications by authors named "Claire Whitworth"

Article Synopsis
  • Mutations in the KRAS protein are common in cancer, with a notable example being the G12C mutation, which has targeted treatments.
  • Researchers developed a novel small molecule that can degrade many KRAS mutations, demonstrating more effective and lasting effects compared to traditional inhibition.
  • Their findings showed that this approach not only effectively kills cancer cells with KRAS mutations but also spares normal cells, leading to reduction in tumors in animal models.
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Article Synopsis
  • Targeted protein degradation is a new approach in drug discovery, but the natural half-life of proteins greatly influences how effective these degraders are, and this relationship hasn’t been thoroughly studied.
  • Research shows that short-lived proteins can misleadingly appear to be degraded by agents that actually halt protein synthesis, like GSPT1 degraders and cytotoxic drugs.
  • The findings indicate that understanding a target protein's half-life is crucial for selecting targets and designing control experiments to validate the effectiveness of new protein degrading agents.
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Targeted protein degradation offers an alternative modality to classical inhibition and holds the promise of addressing previously undruggable targets to provide novel therapeutic options for patients. Heterobifunctional molecules co-recruit a target protein and an E3 ligase, resulting in ubiquitylation and proteosome-dependent degradation of the target. In the clinic, the oral route of administration is the option of choice but has only been achieved so far by CRBN- recruiting bifunctional degrader molecules.

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Article Synopsis
  • Bivalent proteolysis-targeting chimeras (PROTACs) can degrade proteins by binding to both the target protein and an E3 ligase, forming a stable ternary complex.
  • Researchers modified PROTACs to create trivalent versions, which show increased effectiveness and stability due to enhanced binding, specifically focusing on a compound named SIM1 that targets bromodomain-containing proteins.
  • SIM1 demonstrated superior degradation and anticancer efficacy compared to bivalent PROTACs, showcasing the potential of increasing binding valency to improve protein degradation strategies in therapeutic contexts.
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In the version of this article originally published, several lines of text in the last paragraph of the right column on page 1 of the PDF were transposed into the bottom paragraph of the left column. The affected text of the left column should read "The ATP-dependent activities of the BAF (SWI/SNF) chromatin remodeling complexes affect the positioning of nucleosomes on DNA and thereby many cellular processes related to chromatin structure, including transcription, DNA repair and decatenation of chromosomes during mitosis." The affected text of the right column should read "SMARCA2/4 inhibitors are thus precluded from use for the treatment of SMARCA4 mutant cancers but could provide attractive ligands for PROTAC conjugation.

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Targeting subunits of BAF/PBAF chromatin remodeling complexes has been proposed as an approach to exploit cancer vulnerabilities. Here, we develop proteolysis targeting chimera (PROTAC) degraders of the BAF ATPase subunits SMARCA2 and SMARCA4 using a bromodomain ligand and recruitment of the E3 ubiquitin ligase VHL. High-resolution ternary complex crystal structures and biophysical investigation guided rational and efficient optimization toward ACBI1, a potent and cooperative degrader of SMARCA2, SMARCA4 and PBRM1.

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Bifunctional degrader molecules, known as proteolysis-targeting chimeras (PROTACs), function by recruiting a target to an E3 ligase, forming a target/PROTAC/ligase ternary complex. Despite the importance of this key intermediate species, no detailed validation of a method to directly determine binding parameters for ternary complex kinetics has been reported, and it remains to be addressed whether tuning the kinetics of PROTAC ternary complexes may be an effective strategy to improve the efficiency of targeted protein degradation. Here, we develop an SPR-based assay to quantify the stability of PROTAC-induced ternary complexes by measuring for the first time the kinetics of their formation and dissociation in vitro using purified proteins.

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Neurogenesis is a complex process leading to the generation of neuronal networks and glial cell types from stem cells or intermediate progenitors. Mapping subcellular and molecular changes accompanying the switch from proliferation to differentiation is vital for developing therapeutic targets for neurological diseases. Neuronal (N-type) and glial (S-type) phenotypes within the SH-SY5Y neuroblastoma cell line have distinct differentiation responses to 9-cis-retinoic acid (9cRA).

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The molecular genetic mechanisms underlying fruit size remain poorly understood in perennial crops, despite size being an important agronomic trait. Here we show that the expression level of a microRNA gene (miRNA172) influences fruit size in apple. A transposon insertional allele of miRNA172 showing reduced expression associates with large fruit in an apple breeding population, whereas over-expression of miRNA172 in transgenic apple significantly reduces fruit size.

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COX2 is an inducible cyclooxygenase implicated in the metastasis and migration of tumour cells. In neuroblastoma, COX2 expression has been detected in both cell lines and tumours. The treatment of neuroblastoma cells in vitro with celecoxib, a COX2 inhibitor, induces apoptosis.

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Retinoic acid (RA) has paradoxical effects on cancer cells: promoting cell death, differentiation and cell cycle arrest, or cell survival and proliferation. Arachidonic acid (AA) release occurs in response to RA treatment and, therefore, AA and its downstream metabolites may be involved in cell survival signalling. To test this, we inhibited phospholipase A2-mediated AA release, cyclooxygenases and lipoxygenases with small-molecule inhibitors to determine if this would sensitise cells to cell death after RA treatment.

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Background: Understanding the genetic architecture of quantitative traits is important for developing genome-based crop improvement methods. Genome-wide association study (GWAS) is a powerful technique for mining novel functional variants. Using a family-based design involving 1,200 apple (Malus × domestica Borkh.

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The genome sequence of apple (Malus×domestica Borkh.) was published more than a year ago, which helped develop an 8K SNP chip to assist in implementing genomic selection (GS). In apple breeding programmes, GS can be used to obtain genomic breeding values (GEBV) for choosing next-generation parents or selections for further testing as potential commercial cultivars at a very early stage.

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Flavor is an important quality trait of fruit and a target for improvement through plant breeding. Eighty-nine flavor volatiles from 240 apple (Malus domestica) genotypes from a highly diverse breeding population were measured by headspace gas chromatography-mass spectrometry (GC-MS) over 2 years. Heritabilities and phenotypic and genetic correlations were calculated for 23 flavor volatiles.

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Background: Integrating plant genomics and classical breeding is a challenge for both plant breeders and molecular biologists. Marker-assisted selection (MAS) is a tool that can be used to accelerate the development of novel apple varieties such as cultivars that have fruit with anthocyanin through to the core. In addition, determining the inheritance of novel alleles, such as the one responsible for red flesh, adds to our understanding of allelic variation.

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