Fig. 1

Effects of spheroid formation and growth. a: HT1080, RD, SW872 and HOSS1 soft sarcoma cell lines grown in 3D culture at day 8. HOSS1 cells established from an osteosarcoma PDX were also grown in special medium without FBS. b: Cell counts in 3D cultures at various time points. c: Cell counts in 3D spheres between weeks 1 and 2 were not significantly different (range: 40–65 %). d Stable proliferation of the four cell lines in 3D culture. HT1080 cells required 4 days, whereas the other cell lines needed 8 days. The four cell lines underwent stable growth after these initial periods. e, f: Cell numbers and growth time in 2D cultures at various times. In contrast to 3D cultures, cells did not lose stability until 10 days in 2D culture. Shaded areas indicate stable proliferation. g: Doubling times of 2D and 3D cell cultures at day 8 after plating. Results are the mean ± SD (n = 6). N.S., not significant, Bar = 100 μm