Extended data figure 7. Histological analysis of xenograft tumours and ChIP-seq from xenograft tumours in ovariectomised mice.

a. Histological analysis of MCF-7 xenograft tumours in untreated, estrogen or estrogen plus progesterone conditions. Tumours were taken from 25 day treated conditions. The human xenograft cells expressed GFP, permitting discrimination between human tumour cells and mouse host cells. MCF-7 xenograft experiment in ovariectomised mice. b. In order to map ERα binding events by ChIP-seq in MCF-7 xenograft tumours, we repeated the experiment in ovariectomised mice to eliminate any issues related to the endogenous mouse progesterone. Ten tumours for each condition (two in each of five mice per condition) were included. Growth of xenograft tumours under different hormonal conditions, Control, estrogen alone (E2) and estrogen plus progesterone (E2 + Prog). The data was analysed using a t-test and the error bars represent +/- SEM. c. ChIP-seq for ERα and PR were conducted in six matched tumours from each hormonal condition. Also included were two tumours from no hormone conditions. Correlation heatmap of all samples.