GSE169658
JAZF1-SUZ12 dysregulates PRC2 recruitment and gene expression during cell differentiation
Polycomb repressive complex 2 (PRC2) maintains repression of genes specific for other cell differentiation stages through methylation of histone H3 lysine 27 (H3K27me3) and is regulated by nascent RNA. In endometrial stromal sarcoma, the PRC2 subunit SUZ12 is often fused with the transcription factor JAZF1. How JAZF1-SUZ12 affects PRC2 function and cell differentiation are unknown. Here, we show that JAZF1-SUZ12 disrupts PRC2 recruitment, gene expression and cell differentiation. The loss of the SUZ12 N-terminus in the fusion protein disrupted interaction with JARID2, EPOP and PALI1 and prevented recruitment of PRC2 from RNA to chromatin. JAZF1-SUZ12 occupied PRC2 target genes in undifferentiated cells but relocated to JAZF1 target genes during cell differentiation, altering patterns of H3K27me3 and gene expression and disrupting cell differentiation. We then performed RNA-seq in primary human cells expreesing all proteins, showing that JAZF1-SUZ12 was promoting a specific set of genes upregulated in decidualisation, while blocking immune related genes.  These results reveal the defects in PRC2 function and cell differentiation caused by the JAZF1-SUZ12 fusion protein, which may underlie its role in oncogenesis. Overall design: Suz12 GT/GT cell lines stably expressing FLAG-tagged proteins SUZ12, SUZ12D93, JAZF1-SUZ12 and JAZF1 were differentiated into Embryoid Bodies by removal of LIF and forced aggregation. After differentiation, at days 0,4 and 8 we generated calibrated ChIP-seq data using the FLAG epitope to see the binding profile of all 4 proteins. Additionally, we performed calibrated ChIP-seq at days 0 and 8 of H3K27me3 and H4ac. For assays in human endometrial stromal cells (hEnSC), cells were transduced with the same FLAG-tagged proteins, and differentiated for 8 days with medroxyprogesterone and 8?-Br-cAMP to generate decidual cells. Total RNA from days 0 and 8 of treatment was used for bulk RNA-seq to establish changes in gene expression