Figure 6 from Screening FDA-Approved Oncology Drugs with Three-Dimensional Spheroids Identifies Romidepsin as a Therapeutic Candidate for Osteosarcoma

<p>The primary effects of romidepsin are a transient block in proliferation for 143B sarcospheres and cytotoxicity for LM7 sarcospheres. 143B (<b>A–D</b>) and LM7 (<b>E–H</b>) <b>s</b>arcospheres were exposed to the indicated concentrations of romidepsin or vehicle for 24 hours (<b>A</b>, <b>B</b>, <b>E</b>, and <b>F</b>) or the indicated times (<b>C</b>, <b>D</b>, <b>G</b>, and <b>H</b>). <b>A</b> and <b>E,</b> Cell cycles were analyzed by flow cytometry after exposure to 10 nmol/L romidepsin or vehicle for 24 hours. Each symbol represents the percentage of the cell population in each phase from an individual experiment with 30 sarcospheres per group. Colored bars show means ± SD of <i>N</i> = 3–4 independent experiments. A one-way ANOVA with a Dunnett multiple comparisons test was used to compare experimental groups with the vehicle control group *, <i>P</i> < 0.05; ***, <i>P</i> < 0.01; ****, <i>P</i> < 0.001. <b>B</b> and <b>F,</b> Recovery from a 24-hour romidepsin exposure was assessed by repeated measurements of metabolic activity on days 2, 4, 8, and 14 after romidepsin addition. All repeated measurements were on the same set of sarcospheres, except that measurements on day 0 were on a separate plate of sarcospheres. Each symbol represents mean ± SD of <i>N</i> = 3 independent experiments. Each experiment included six sarcospheres per dose group. Friedman one-way repeated measures ANOVA by ranks with a Dunn multiple comparisons test was used to compare each experimental group with the vehicle control group over time. ***, <i>P</i> < 0.001. <b>C</b> and <b>G,</b> Sarcosphere diameters were measured every 2 hours during exposure to the indicated concentrations of romidepsin or vehicle by the Incucyte S3 Live Cell Analysis System (Sartorius). Each symbol represents mean ± SEM of <i>N</i> = 3–4 independent experiments. Each experiment included 3–6 sarcospheres per dose group. A Friedman test with a Dunn multiple comparisons test was used to compare each experimental group with the vehicle control group for 143B sarcosphere size experiments: *, <i>P</i> < 0.05 (1 nmol/L group), ***, <i>P</i> < 0.001 (10–10,000 nmol/L groups). <b>D</b> and <b>H,</b> Representative images from experiments depicted in <b>C</b> and <b>G</b>. Yellow size bars on the lower left of images show 800 mm. Timestamp is indicated in the lower right of each image.</p>