Fig. 2

Characteristics of medulloblastoma cells recovered from the pleural effusions after progression of disease. a. Representative flow cytometry plots outlining the expression of CD133 and CD15 in MB3W1 cells. b. Light-microscopy of MB3W1 cells in culture in serum-free medium showing sphere forming growth (left) and partly adherent growth in serum-containing medium (right). c. Growth characteristics of MB3W1 cells grown in serum-free medium (left, purple columns), compared to growth in serum-containing medium (right, light blue columns = adherent fraction, dark blue columns = spheroid fraction). d. Expression of CD133 on cells grown as spheres in serum-free medium at in vitro passage 1 (blue full line) and passage 30 (blue broken line). Black line = isotype control. e. ALDH expression as measured by substrate conversion using the ALDEFLUOR assay. Different cell lines were incubated with ALDH-substrate either without (green lines) or with a specific enzyme inhibitor to block ALDH-activity (black lines). The degree of fluorescence correlates with ALDH-activity. R28 and R11 are glioblastoma cell lines recently characterized as cells with CSC activity. U251 is a glioblastoma cell line with no known CSC activity