Extended Data Figure 1 : Early lesion signature induction and expression of HER2 and PGR.

From: Early dissemination seeds metastasis in breast cancer

Extended Data Figure 1

a, The proportion of cancer cells disseminating to the bone marrow in BALB-NeuT mice decreases with increasing primary tumour area. DCCs were identified using anti-cytokeratin antibodies in bone marrow samples. The y axis displays the number of detected DCCs per 106 bone marrow cells divided by the total tumour area in mm2. The number of mice used per data point is written below the graph. b, Laser microdissection of epithelial structures: two examples of 7–9-week-old BALB-NeuT mammary glands showing microdissection of regions with incipient epithelial hyperplasia. For all samples similar amounts of tissue (up to 100,000 μm2) were isolated. c, qPCR validation of microarray profiles. qPCR was performed for 10 genes, upregulated or downregulated in microarray samples of early lesions and all changes, except one (Zfp408), were confirmed. d, qPCR for the mRNA level of all steroid hormone receptors (EL, early lesions; PT, advanced primary tumour; Met, lung metastasis). e, Primary cultures from mammary tissue of 7–9-week-old BALB-NeuT mice, were treated with different concentrations (1, 10, and 100 nM) of progesterone (P), oestrogen (E), aldosterone (A), cortisol (C), testosterone (T) or vehicle (ethanol; untreated) for 75 h. Only progesterone induces upregulation of the complete early lesion signature. f, Increased expression of PGR-B in young mammary glands (9-week old BALB/c and BALB-NeuT mice with early lesions compared to 25-week-old BALB/c mice), but not primary tumours correlates with increased HER2 expression. g, Progesterone induces the early lesion signature in 4T1 cells (highly aggressive and metastatic cell line derived from a spontaneous BALB/c mammary tumour), but not in 67NR (tumorigenic and non-metastatic cell line derived from a spontaneous BALB/c mammary tumour) and MM3MG cells (normal mammary epithelial cell line derived from a BALB/c mouse). h, Progesterone treatment induces upregulation of HER2 expression in 4T1 cells. i, Overexpression of PGR-B in MM3MG cells induces upregulation of HER2 expression. ****P ≤ 0.0001 (Student’s t-test and Stouffer’s combined probability test); data are mean ± s.d. For gel source data, see Supplementary Fig. 1.