Fig. 3: Luminal and basal-like subpopulations display phenotypic plasticity.

a Dissociated cells from a freshly harvested WT PyMT tumor were profiled by FACS (top, panel 1), using antibodies for EpCAM and CD49f. Basal-like cells are defined as EpCAM^lowCD49f^high (upper left quadrant), while luminal cells (including also luminal progenitors) are defined as EpCAM^highCD49f^high (upper right quadrant). After 13 passages in culture, the small basal-like subpopulation was enriched by FACS sorting (panel 2), followed by additional passaging in culture and FACS analysis (panel 3). The basal-like subpopulation was then enriched again (panel 4) and further cultured, with intermittent FACS profiling after the number of passages indicated above the arrows (panels 5–7). Bold black shapes labeled “basal-sort” depict the gates used for FACS-enrichment of the basal-like cell population. b WT PyMT cells were harvested in parallel to the FACS analyses, and mRNA was extracted and analyzed by RT-qPCR to quantify the expression levels of LATS1-repressed, “basal” genes. Values were normalized to Hprt expression. “panel” refers to the corresponding panel number in (a). The cumulative number of passages is also indicated. Data are presented as mean values ± SD of three technical replicates. Source data are provided as a Source Data file. c WT and Lats1-CKO luminal-enriched cells were injected into mouse mammary fat pads. Four weeks later, tumors were harvested, dissociated, and subjected to FACS analysis. Representative FACS profiles of cells pre-injection and from dissociated tumors are shown (left). A graphical representation of the relative portions of luminal (high EpCAM) and basal-like (low EpCAM) cells are shown on the right (mean ± SE of five mice from each group). One-way ANOVA was used to compute significance. Source data are provided as a Source Data file.