Figure 8: R-Ras2 is important for Her2-mediated tumorigenesis.

(a) Representative mammary fat pads from mice of indicated ages (top) and genotypes (left). Scale bar, 500 μm. Insets show enlarged views of boxed areas (scale bar, 50 μm). *Lymph node. (b) Quantification of area (left), maximal length (middle) and terminal end bud (TEB) numbers (right) of glands from mice of indicated ages and genotypes (n=5). *P≤0.05; **P≤0.01; ***P≤0.001 relative to appropriate control; t-test. (c) Phosphorylation and expression status of indicated proteins in EGF-stimulated MECs obtained from 6-month-old female mice. (d) Tumour-free survival of MMTV-Her2tg;Rras2+/+ (n=20) and MMTV-Her2tg;Rras2−/− (n=22) mice. ***P≤0.001 relative to controls at the final experimental time point; t-test. (e) Tumour per mouse average in MMTV-Her2tg;Rras2+/+ (n=20) and MMTV-Her2tg;Rras2−/− (n=22) mice. ***P≤0.001 relative to controls at the final experimental time point; t-test. (f) Average size of tumours developed in MMTV-Her2tg;Rras2+/+ (n=20) and MMTV-Her2tg;Rras2−/− (n=22) mice. **P≤0.01 relative to controls at the final experimental time point; t-test. In b, d, e and f, values are given as mean±s.e.m. (g) Mean percentage of tumour-bearing mice with lung metastases. (h) Representative whole mount-stained (top panels; scale bar, 500 μm) and haematoxylin/eosin-stained (bottom panels; scale bar, 100 μm) samples from inguinal, ‘non-tumorigenic’ mammary glands from indicated mice (top). White asterisks, inguinal lymph nodes; white arrowhead, example of a small adenocarcinoma; black asterisk, example of cystic dilation; black arrowheads, examples of hyperplasic lobulo-alveolar units. (i) Quantification of hyperplasic parameters in ‘non-tumorigenic’ mammary glands from indicated mice. Grade 0, no hyperplasia; grade 1, glands with ductal ramifications, lobulo-alveolar terminal units or cystic dilatations; grade 2, glands showing at least two of those hyperplasic parameters. n=15 and 21 control, and MMTV-Her2tg;Rras2−/− mice, respectively. (j) Phosphorylation and expression status of indicated proteins (left) in tumour samples (top) obtained from control and MMTV-Her2tg;Rras2−/− mice.