Related Experiment Video
Updated: May 13, 2025
Method for Identifying Small Molecule Inhibitors of the Protein-protein Interaction Between HCN1 and TRIP8b
Published on: November 11, 2016
Identification of substituted acetanilide compounds as small molecule CBX2 inhibitors via in silico screening
Shohei Takase1, Ashutosh Kumar2, Sho Yokoyama3
1School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo, 192-0392, Japan.
Abstract:
The chromodomain protein CBX2 binds directly to histone H3 trimethylation at lysine 27 (H3K27me3) and is a component of polycomb repressive complex 1 (PRC1). CBX2 plays a pivotal role in transcriptional repression by acting as a reader protein that recognizes H3K27me3. In this study, we performed in silico screening based on the crystal structure of CBX2 to identify small molecule compounds that target the chromodomain of CBX2. The ability of the selected compounds to inhibit the interaction between CBX2 and histone H3 in cells was validated. After three rounds of in silico screening, CG3-46 was ultimately identified as the most potent CBX2 inhibitor in this study. CG3-46 inhibited the growth of the triple-negative breast cancer cell line MDA-MB-231, accompanied by an increase in the expression of a CBX2 target gene. Our results indicate that CG3-46 represents the first nonpeptide small molecule inhibitor of CBX2, which not only serves as a valuable chemical tool for elucidating the role of CBX2 in cellular epigenetic regulation but also as a starting compound for the development of CBX2-targeted therapeutics for triple-negative breast cancer.
Insights
Researchers identified CG3-46, the first small molecule inhibitor targeting the chromodomain protein CBX2. This compound inhibits cancer cell growth and offers a new tool for epigenetic research and triple-negative breast cancer therapeutics.
Area of Science:
- Epigenetics
- Molecular Biology
- Drug Discovery
Background:
- CBX2, a chromodomain protein, recognizes histone H3 trimethylation at lysine 27 (H3K27me3) and is part of polycomb repressive complex 1 (PRC1).
- CBX2 functions as a reader protein crucial for transcriptional repression.
Purpose of the Study:
- To identify small molecule inhibitors targeting the CBX2 chromodomain using in silico screening.
- To validate the inhibitory activity of identified compounds on the CBX2-histone H3 interaction in cells.
- To evaluate the therapeutic potential of the lead compound in triple-negative breast cancer.
Main Methods:
- In silico screening based on the crystal structure of CBX2.
- Validation of compound efficacy in inhibiting CBX2-histone H3 interaction in cellular assays.
- Assessment of cell growth inhibition and gene expression changes in cancer cell lines.
Main Results:
- CG3-46 was identified as the most potent CBX2 inhibitor after three rounds of in silico screening.
- CG3-46 demonstrated inhibition of triple-negative breast cancer cell line MDA-MB-231 growth.
- A significant increase in a CBX2 target gene expression was observed following CG3-46 treatment.
Conclusions:
- CG3-46 is the first nonpeptide small molecule inhibitor of CBX2.
- This compound serves as a valuable chemical probe for studying CBX2's role in epigenetic regulation.
- CG3-46 is a promising starting point for developing novel therapeutics for triple-negative breast cancer.
