Fig. 4. Imetelstat is a potent inducer of ferroptosis.
a, Lipid desaturation analysis of FADS2-edited (FADS2-sg1 and FADS2-sg2) or non-edited (empty vector control) NB4 cells treated with imetelstat (4 μM at a seeding density of 2.5 × 105 cells per ml culture) or vehicle control (PBS) for 24 h. The graph depicts the median log2FC of the number of total unsaturated bonds in lipid species in the respective comparisons outlined in the legend. Shading represents the 95% CI. n = 3 replicates from distinct cell passages and independent experiments. b,c, CellROX Green (b) and C11-BODIPY (c) analysis in ACSL4-edited (n = 4 independent gRNAs), FADS2-edited (n = 2 independent gRNAs) or non-edited (n = 2 independent replicates, Cas9, empty vector) NB4 or MV411 cell lines treated with imetelstat (4 μM) or PBS. Time points of analysis were 24 h (NB4) and day 4 (MV411). Three technical replicates per condition were pooled. Data are presented as mean ± s.e.m. One-way analysis of variance (ANOVA) was used and adjusted for multiple comparisons. NB4, P < 1 × 10−4 (non-edited + PBS versus non-edited + imetelstat), P = 2 × 10−4 (non-edited + imetelstat versus ACSL4-edited + imetelstat), P = 2 × 10−4 (non-edited + imetelstat versus FAD2S-edited + imetelstat); MV411, P < 1 × 10−4 (non-edited + PBS versus non-edited + imetelstat), P < 1 × 10−4 (non-edited + imetelstat versus ACSL4-edited + imetelstat), P < 1 × 10−4 (non-edited + imetelstat versus FADS2-edited + imetelstat) (b). NB4, P < 1 × 10−4 (non-edited + PBS versus non-edited + imetelstat), P < 1 × 10−4 (non-edited + imetelstat versus ACSL4-edited + imetelstat), P < 1 × 10−4 (non-edited + imetelstat versus FADS2-edited + imetelstat); MV411, P < 1 × 10−4 (non-edited + PBS versus non-edited + imetelstat), P < 1 × 10−4 (non-edited + imetelstat versus ACSL4-edited + imetelstat), P < 1 × 10−4 (non-edited + imetelstat versus FADS2-edited + imetelstat) (c). A repeat experiment was performed that replicated the results.