Figure 1. OTS964 disturbed the growth of the size of glioma stem cell populations in a dose dependent manner.

We seeded glioma cell line-derived cells in methylcellulose-containing growth medium at an initial clonal density of 4,000 cells/2 ml in each well of 12 well-plates. Each clone differentially grew and some became glioma spheres: GSs. A and B, Consistent growth in the size of U87 (A) or U251 (B) -derived GSC population in the methylcellulose-containing growth media. The size of an entire glioma sphere (GS)-forming cell population was calculated as the summation of number of cells of all clones, or as the product of multiplication of the average number of cells/clone by the number of survived clones. The size, as number of cells in an entire population, is shown at each time point (0, 4, 7 days for A and B; 14, 21, 28 days for B, respectively). The data for 5 generations are shown (1st shown in black filled circles; 2nd: blue; 3rd: green; 4th: orange; 5th: red, respectively). The cell populations were consistently grew during cultured period at every generation. C-N, Dose dependent suppression in the growth of the GS population in the presence of OTS964. The sizes of the cell population of all clones (C–E); of self-renewed clones (F–H for clones with multiple cells); of expanded clones (I–K for clones with more than 4 cells; L–N for clones with more than 9 cells) are shown at various concentrations of OTS964 (0, 20, 100, 200, 300 and 500 nM). The graphs are for U87- (C, F, I and L) and for U251-derived (D, E, G, H, J, K, M and N) GS clones. The data of 20, 100 and 500 nM were taken from the first series of experiments; 200 nM, the second; 300 nM, the third; and the control (0 nM) from the first through the fourth series. OTS964 disturbed the growth of the size of GS-forming cell population, and the effects were dose-dependent.