Dataset Information

Disruption of YY1-EZH2 Interaction Using Synthetic Peptides Inhibits Breast Cancer Development.

ABSTRACT: Enhancer of zeste homolog 2 (EZH2) is a methyltransferase to mediate lysine 27 trimethylation in histone H3 (i.e., H3K27me3) and repress gene expression. In solid tumors, EZH2 promotes oncogenesis and is considered a therapeutic target. As a transcription factor, Yin Yang 1 (YY1) recruits EZH2 through its oncoprotein binding (OPB) domain to establish gene repression. In this study, we mapped the YY1 protein binding (YPB) domain on EZH2 to a region of 27 amino acids. Both YPB and OPB domain synthetic peptides could disrupt YY1EZH2 interaction, markedly reduce breast cancer cell viability, and efficiently inhibit tumor growth in a xenograft mouse model. We analyzed MDA-MB-231 cells treated with YPB, OPB, and control peptides by chromatin immunoprecipitation DNA sequencing (ChIP-seq) using an antibody against H3K27me3. YPB and OPB treatments altered H3K27me3 on 465 and 1137 genes, respectively, compared to the control. Of these genes, 145 overlapped between the two peptides. Among them, PTENP1, the PTEN pseudogene, showed reduced H3K27me3 signal when treated by either YPB or OPB peptide. Consistently, the two peptides enhanced both PTENP1 and PTEN expression with concomitantly reduced AKT activation. Further studies validated PTENP1's contribution to the anticancer activity of YPB and OPB peptides.

SUBMITTER: Yi C

PROVIDER: S-EPMC8156467 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Background:Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer that lacks expression of estrogen receptor (ER) and progesterone receptor (PR) and the human epidermal growth factor receptor 2 (HER2) gene. Chemotherapy remains the standard of care for TNBC treatment, but considerable patients are very resistant to chemotherapy. Mutations or aberrant upregulation of EZH2 occur frequently, and EZH2 inhibitor (EZH2i) showed some preclinic antitumor effects in TNBC. Methods:RNA-seq data of 3 TNBC cell lines either treated with 2 ?M GSK343, or stably transduced with shEHZ2, compared to untreated controls (GSE112378) were analyzed by Limma R package. The Kaplan-Meier plotter (KM plotter) database was used to assess the relevance of FOSB mRNA expression to relapse-free survival (RFS) in TNBC. Cell number counting and colony formation assays were used to detect the biological effect of FOSB on the growth of TNBC cells in vitro. The effect of FOSB on TNBC tumor growth in vivo was investigated in a mice tumor xenograft model. Luciferase reporter and chromatin immunoprecipitation (Chip) assays were used to determine the regulatory roles of C/EBP? on FOSB expression. Results:We found that FOSB, a member of the activator protein-1 complex, was a direct downstream target of EZH2. FOSB was significantly decreased in TNBC samples and associated with better relapse-free survival (RFS). EZH2-mediated histone 3 trimethylated on lysine 27 (H3K27me3), a marker of silent chromatin conformation, at the FOSB promoter inhibited it expression. Depletion of FOSB in TNBC cells promoted cell proliferation in vitro and tumor growth in vitro by inactivating the p53 pathway and conferred resistant to EZH2 inhibitor (EZH2i). Mechanistically, EZH2i promotes the shift from H3K27me3 to H3K27ac at the FOSB promoter, and recruits the transcription factor C/EBP? to activate FOSB gene transcription. Conclusion:Together, our results suggest that EZH2-mediated epigenetic inactivation of FOSB promotes TNBC expression and demonstrate that reactivation of FOSB expression by C/EBP? underlies the anti-TNBC action of EZH2is.

Dataset Information

Disruption of YY1-EZH2 Interaction Using Synthetic Peptides Inhibits Breast Cancer Development.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets