U343-MG xenografts with knockdown of SOX2 are tumorigenic and show a increased spreading in the mouse brain. a: Kaplan-Meier curves showing the survival of mice transplanted with 5 × 105 U343-MG cells with knock down of SOX2 and transduced with shLuc, respectively. Two independent experiments are depicted, which show a significantly reduced survival of mice transplanted with SOX2 depleted U343-MG cells. Number of animals for each experiment and p values for logRank-test are depicted. b: Semi-quantitative analysis of tumor size and specific traits of tumor spreading in the brain. Glioma cells with knockdown of SOX2 shows strong increased infiltration following vessels and diffuse infiltration into the normal brain parenchyma. Bars indicate standard deviation. The p values for student's t-Test are shown. c: Representative images of U343-MG gliomas in mouse brain. A-C: U343-MG tumors transduced with shLuc; D-I: U343-MG tumors transduced with shSOX #2378: A: Small superficially growing shLuc tumor (arrow heads) despite an intracerebral tumor cell reservoir (asterisk). B, C: Magnifications of the tumor area shows a compact growth pattern with clearly visible tumor borders and minimal single cell infiltration (arrowheads). D: U343-MG tumors with knockdown of SOX2 showing multilocular intracerebral growth (asterisks). E: Magnification of the tumor area showing two distinct tumor populations with spindle cell morphology and smaller rounded nuclei (#). Asterisks mark an area with intense single cell infiltration. F: Further magnification of the same area reveals tumor cells with spindle cell morphology growing along performed perivascular spaces (arrowheads). G: U343-MG cells with knock down of SOX2 growing at perivacsular spaces (arrowheads). H: Necrosis in U343-MG tumor with knockdown of SOX2 (asterisk). I: Area of U343-MG tumor with knockdown of SOX2 with small rounded nuclear morphology and glomeruloid vascular endothelium proliferation (arrowheads). Magnification bars for A and D: 160 μm; B and E: 80 μm; C, F, G, and I: 40 μm. n.d.: not detected.