Fig. 1. Smarcb1 deficiency in early embryonic Sox2-positive cells promotes RT development.
A Representative H&E stainings of intra- and extracranial tumor samples derived from constitutive Sox2-cre::Smarcb1fl/+ mice. Tumors were detected in the frontal-basal region of the brain (a–d) or in the eye (e–h), and extracranial tumors (eRT) were localized in the oral cavity (i–l) or in the thorax (m–p). All tumors are characterized by loss of Smarcb1 protein (c, g, k, o) and are proliferative as indicated by Ki67 staining (d, h, l, p). Scale bars indicate 200 µm (a, e, i, m), and 20 µm in all remaining images. Arrowheads point at Smarcb1-negative cells. n = 19 tumors were stained, representative images are shown. B Sox2-creERT2::Smarcb1fl/fl mice developed RT when loss of Smarcb1 was induced in utero by the application of tamoxifen at E6.5 post coitum (p.c.) (upper scheme), but not later. Mice developed intracranial (IC) tumors at the lower brain surface (a–d), at the eye region (e–h) or eRT in the oral cavity (i–l). Smarcb1 staining depicts loss of Smarcb1 protein (c, g, k) and Ki67 staining indicates high proliferative capacity (d, h, l). Scale bars indicate 100 µm (i), 50 µm (a, e), and 20 µm in all remaining images. Arrowheads point at Smarcb1-negative cells. n = 14 tumors were analyzed, representative images are shown. See also Supplementary Figs. 1–3.