GSE104981
KDM5B links cellular transcriptome heterogeneity to therapy resistance (Barcode)
The KDM5B histone H3 lysine 4 (H3K4) demethylase has been implicated in therapy resistance in multiple cancer types including breast cancer, but the underlying mechanism is poorly defined. Here we show that inhibition of KDM5B activity increases sensitivity to anti-estrogens by modulating estrogen-receptor (ER) signaling. Conversely, acquired resistance to KDM5 inhibitors leads to gain of ER chromatin binding and estrogen-independent growth. Sequencing of barcoded cell populations and mathematical modeling demonstrate selection for pre-existent genetically distinct endocrine-resistant cells, while resistance to KDM5 inhibitors is a switch to an acquired epigenetic state. Rare resistant cells can already be detected by single cell RNA-seq prior to treatment. Inhibition of KDM5B in luminal ER+ cells increases H3K4me3 broad domains at promoters and decreases cellular transcriptional heterogeneity. Higher transcriptome heterogeneity is associated with higher KDM5B levels and poor prognosis in ER+ luminal breast tumors. Overall design: Barcoding analyses of parental and multiple resistant breast cancer cell lines