a, Expression of selected epigenetic genes in 1,483 patient
samples (METABRIC dataset) classified by ER status and TP53
mutation. Unsupervised clustering revealed a cohort of
ER-/TP53mut samples with high expression of
CoREST subunits (KDM1A, RCOR2,
HDAC2) and components of the SWI/SNF complex.
b, KDM1A, HDAC2, and
RCOR2 mRNA expression in 1,423 breast cancer samples
grouped by ER expression and TP53 status. The box plots span
from the 25th to 75th percentiles, expression is represented as log10 (RPKM)
with the median (midline of box plots) and maximum/minimum (upper and lower
bounds of whiskers) values depicted. Significance was determined by a
non-parametric Wilcox test (two-sided) and p-values correspond to the comparison
between ER-/TP53mut (MUT) with other subgroups.
c, Kaplan–Meier survival curves segregated by
KDM1A, RCOR2, and HDAC2
expression. Disease-specific survival is significantly diminished for patients
(METABRIC dataset) with high KDM1A, RCOR2, and
HDAC2. P value was calculated using a
log-rank (Mantel–Cox) test. d, Representative FACS of CD24
and CD44 of T47D parental (full media, FM) and 9-month LTED (M, months). CD24
and CD44 expression was monitored every two weeks for over a year (top).
Representative images (bottom) of cells from top panel. Red arrows depict cells
with mixed epithelial and mesenchymal morphology. n = 3
biological independent replicates. e, Heatmap of significantly
upregulated genes (FC > 2, q-value < 0.05) during
acquisition of resistance in T47D. f, GSEA of 8M T47D-LTED cells.
g, Western blot (WB) of T47D FM and LTED whole cell lysates for
the proteins indicated with VINCULIN as a loading control. h, Model
of evolution of resistance. We defined 5M and 6M LTED cells as primed and
>9M as reprogrammed. EMT, epithelial-to-mesenchymal transition.
i, Proliferation of parental, tamoxifen resistant (TamR),
fulvestrant resistant (FulR), and LTED T47D treated with
1µm of DMSO (vehicle), tamoxifen, fulvestrant,
corin, GSK-LSD1, or palbociclib for 7 days, n = 3 biological
independent replicates. Data are presented as mean values + SD
(p-value < 0.001, two-way ANOVA). Uncropped images
for g are available as source data.