Impaired histone inheritance promotes tumor progression

In this study, we constructed a tumor model of impaired inheritance of parental histones by introducing an MCM2 histone-binding domain (HBD) mutation in the breast cancer cell lines MCF-7. In this model, impaired histone inheritance resulted in dramatic epigenetic reprogramming, especially the pattern of the repressive histone mark H3K27me3, and promoted tumor growth and metastasis in vivo. We used breast cancer MCF-7 cell line (Wild type and MCM2-2A mutant cells) in this study. ATAC-seq method was used to evaluate the chromatin accessibility and CUT&Tag-seq and ChIP-seq were adopted to study the chromatin-binding affinity of histones, histone marks and their associated complex members. In both WT and MCM2-2A MCF-7 cells, we employed ATAC-seq, CUT&Tag-seq of H3.3, H3K27me3, H3K27ac, H3K9me3, H3K4me3, H3K4me1, H3K36me3, SUZ12, H2AK119ub and RING1B, as well as ChIP-seq of H3K36me2 and EZH2. H3K27me3 CUT&Tag experiments above were also implemented in POLE3 KO MCF7 cells. In addition, CUT&Tag for H3K27me3, H3K4me3 and H3.3 were performed in WT and MCM2-2A mutant HEK293T cells, as well as in WT and MCM2-90A mutant T47D cells. Bulk RNA-seq and scRNA-seq in vitro and in vivo were also implememted.