Fig. 3: IM and basal cells transit to a luminal fate in the presence of ERG.
From: ERG-driven prostate cancer initiation is cell-context dependent and requires KMT2A and DOT1L
a, EdU pulse–chase assay on EPC mice at 2 months of age (schematic on the left). Indicated lineage representation was analyzed from whole prostate cells on the right (n = 5 mice for pulse, n = 4 mice for chase). The EdU+ population of ERG+ cells (normalized to all ERG+ cells) shows an increase of SPlum cells and decrease of IM after the chase. b, Schematic (top) and representative IF images (bottom) exemplifying symmetric and asymmetric divisions of EdU-labeled cells using EPC mice from a. Scale bars, 5 µm. c, The cell type composition of EdU+ doublets highlights that DP cells are present in all asymmetric divisions and preferentially associate with an SPlum daughter cell (n = 7 mice). d, Schematic showing in vitro generation of an isogenic pair of EP and P organoids. e,f, EdU pulse–chase assay in organoids followed by flow cytometry assessment highlights an ERG-dependent shift of the EdU-labeled cells towards a luminal (SPlum) fate (n = 3 independent assays for pulse, n = 2 independent assays for chase). Representative data (e) and quantification of the luminal fraction in EdU-labeled populations (f) are shown. g, Left: schematic showing EP organoids with a dual lineage reporter knocked in to form C-terminal fusions with endogenous K5 and K8. Middle: live cell imaging highlighting the expected spatial expression pattern of the reporter signals, which enables live sort of basal and luminal cells (schematic on the right). Scale bar, 20 µm. h, The basal- and luminal-derived EP reporter organoids from g were analyzed by flow cytometry based on the reporter signals along the time course postsort (n = 3 independent assays). An ERG-dependent luminal fate transition from basal cells from luminal cells was observed. i, GSEA showing ERG-regulated pathways in basal cells. Data represent mean ± s.d.; one-way ANOVA with Tukey posttest (a); two-sided Fisher’s exact test (c); two-way ANOVA (h). mNG, mNeonGreen; NES, normalized enrichment score; RFP, TagRFP.
