Figure 1. Estrone promotes ER+ breast cancer invasion and metastasis.

(A–D) MCF7 and T47D spheroid invasion in 5% cFBS (no estrogen), 10 nM E1, or 10 nM E2 for indicated times. Representative photomicrographs (A and C). Quantitative analysis (B and D) of sphere area is graphed as mean (±SEM) from at least 3 biological repeat assays, with p values from Student’s t test and ANOVA; see also data for MDA-MB-361 and ZR75–1 in Figures S1A–S1D.

(E) Bioluminescence (BLI) 8 weeks after intravenous (i.v.) injection of luciferase-tagged MCF7-luc cells into NSG mice supplemented with E1, E2, or placebo control pellets; representative images of n = 6 mice/group; see also Figure S1F.

(F) Mean normalized photon flux of BLI (±SEM) of lung metastases at 8 weeks after i.v. injection of mice in (E).

(G) Quantitation of lung and liver metastatic nodules in mice in (E).

(H) Table shows organ metastasis in mice supplemented with E1, E2, or placebo control.

(I) Representative hematoxylin and eosin (H&E)-stained lung and liver. The arrows highlight metastases; see also Figure S1G.

(J) Representative H&E-stained bone is shown with arrow highlighting metastases.

(K) Mean volume/time of orthotopic E0771 tumors from C57BL/6 mice supplemented with E1, E2, or placebo control (C) pellets (n = 5/group), left. Quantification of the lung metastasis in EO771, right graph; see also Figure S1H.

For all graphed data, *p < 0.05, **p < 0.001, and ***p < 0.0001. Scale bars indicate microns.