BRAFV600E maintains the CpG island methylator phenotype, and DNA methylation of PRC2 targets genes in colon cancer

Summary: In colon cancer, the BRAFV600E mutation is strongly associated with the CpG island methylator phenotype (CIMP). Here, we characterized the contribution of BRAFV600E to maintenance of aberrant DNA methylation using CRISPR-LbCpf1-corrected BRAF (V600E) organoids. DNA methylation analyses iden...

Full description

Saved in:
Bibliographic Details
Main Authors: Layla El Bouazzaoui, Jeroen M. Bugter, Emre Küçükköse, André Verheem, Jasmin B. Post, Nicola Fenderico, Inne H.M. Borel Rinkes, Hugo J.G. Snippert, Madelon M. Maurice, Onno Kranenburg
Format: Article
Language:English
Published: Elsevier 2025-07-01
Series:iScience
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2589004225011666
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Summary: In colon cancer, the BRAFV600E mutation is strongly associated with the CpG island methylator phenotype (CIMP). Here, we characterized the contribution of BRAFV600E to maintenance of aberrant DNA methylation using CRISPR-LbCpf1-corrected BRAF (V600E) organoids. DNA methylation analyses identified 5,187 differentially methylated CpGs within CpG islands—82% hypermethylated in BRAFV600E organoids—including CIMP-associated genes and polycomb repressor complex 2 (PRC2) target genes. RNA sequencing showed concordant repression of these genes. Furthermore, BRAFV600E organoids demonstrated high expression of PRC2 core components (EZH2, SUZ12, and EED), showed PRC2-induced H3K27 trimethylation in promoter regions, and maintained a PRC2-associated embryonic phenotype. This phenotype was lost following mutation correction or DNA methylation inhibition. These findings show that BRAFV600E maintains aberrant DNA and histone methylation patterns in advanced colon cancer, likely preserving the transformed phenotype. Silencing of PRC2 target genes may contribute to this phenomenon. Epigenetic therapies may have value in the treatment of BRAFV600E-mutant colon cancer.
ISSN:2589-0042