Fig. 3.

Luminobasal-enriched xenografts grow without E in vivo and contain rare cells dual positive for luminal and luminobasal markers. (A) Lines E-3, EWD-3, and EWD-8 were implanted into mammary glands of ovx'd nude mice supplemented with placebo or E. Tumor size was measured weekly and volumes calculated. n = 4 or 5 mice per line per treatment. (B) Tumors from A were paraffin-embedded and stained by dual immunofluorescence for CK5 (red) and ER (green). Percentage CK5⁺ luminobasal content is shown. (Scale bars, 50 μm.) (C) E-treated xenografts grown from EWD-3 cells and MCF-7 cells were stained for CK8/18 (green) and CK5 (red). Arrows show rare cells (yellow) dual positive for CK18 and CK5. (Scale bars, 20 μm.)