Related Experiment Video
Updated: Sep 24, 2025
Method for Identifying Small Molecule Inhibitors of the Protein-protein Interaction Between HCN1 and TRIP8b
Published on: November 11, 2016
Identification of Two Non-Peptidergic Small Molecule Inhibitors of CBX2 Binding to K27 Trimethylated Oligonucleosomes
Lukas Lercher1, Nina Simon1, Andreas Bergmann1
1Proteros Biostructures GmbH, Bunsenstraße 7a, 82152, Planegg, Germany.
Abstract:
The dysregulation of the PRC1/2 complex plays a key role in lineage plasticity in prostate cancer and may be required to maintain neuroendocrine phenotype. [1] CBX2, a key component of the canonical PRC1 complex, is an epigenetic reader, recognizing trimethylated lysine on histone 3 (H3K27me3) [2] and is overexpressed in metastatic neuroendocrine prostate cancer. [3,4] We implemented a screening strategy using nucleosome substrates to identify inhibitors of CBX2 binding to chromatin. Construct design and phosphorylation state of CBX2 were critical for successful implementation and execution of an HTS library screen. A rigorous screening funnel including counter and selectivity assays allowed us to quickly focus on true positive hit matter. Two distinct non-peptide-like chemotypes were identified and confirmed in orthogonal biochemical and biophysical assays demonstrating disruption of CBX2 binding to nucleosomes and direct binding to purified CBX2, respectively.
Insights
Researchers identified new inhibitors targeting CBX2, a protein crucial for neuroendocrine prostate cancer progression. These compounds disrupt CBX2
Area of Science:
- Oncology
- Epigenetics
- Molecular Biology
Background:
- Polycomb Repressive Complex 1/2 (PRC1/2) dysregulation drives prostate cancer lineage plasticity.
- CBX2, a PRC1 component, recognizes H3K27me3 and is overexpressed in metastatic neuroendocrine prostate cancer.
Purpose of the Study:
- To identify inhibitors of CBX2 binding to chromatin.
- To develop novel therapeutic strategies for neuroendocrine prostate cancer.
Main Methods:
- High-throughput screening (HTS) using nucleosome substrates.
- Assays to assess CBX2-nucleosome binding and direct CBX2 interaction.
- Biochemical and biophysical validation of hit compounds.
Main Results:
- Two distinct non-peptide-like chemotypes inhibiting CBX2-nucleosome binding were identified.
- Compounds demonstrated disruption of CBX2 binding to nucleosomes.
- Orthogonal assays confirmed direct binding of compounds to purified CBX2.
Conclusions:
- Novel inhibitors targeting CBX2 were discovered.
- These inhibitors represent potential therapeutic agents for neuroendocrine prostate cancer.
- Disrupting CBX2-chromatin interactions offers a new avenue for prostate cancer treatment.
