Figure 5.

FL118 is ~25× more potent than topotecan in cancer cell growth inhibition and colony formation: (A) Cell growth: HCT-8 cells were treated with either FL118 or topotecan for 72 hours as shown. Cell growth was measured with MTT assay and the data were plotted as growth inhibition percentage. (B and C) Colony formation: After seeding HCT-8 cells in 12-well plates at 100 cells per well overnight, cells were then treated with either FL118 or topotecan for 2 (B) or 6 (C) hours at a series of concentrations as shown. Drugs were then washed out and cells were allowed to grow in new complete medium without drugs for 2 weeks. Cell colonies were stained with Crystal violet solution; images were digitally taken. Triplicate results are shown.