FIGURE 1 from Inhibition of Aurora Kinase Induces Endogenous Retroelements to Induce a Type I/III IFN Response via RIG-I

An endogenous IFN reporter generated at the IFI27 locus was screened against an annotated drug library to identify Aurora kinase inhibitors as a novel hit. A, qPCR of canonical IFN target genes in HCT116 cells after 6, 24, or 48 hours after treatment with 1,000 U/mL IFNα. Significance shown for each gene at each timepoint versus the t = 0 value for that gene. B, Schematic of reporter construct. 2A = P2A or T2A skipper peptide sequence; NLS = SV40 nuclear localization signal; secreted = signal sequence from IL6 to cause export of nanoLuciferase from cells. C,IFI27 luciferase reporter induction after treatment with 2.5 µmol/L 5-azacytidine or 100 nmol/L decitabine for 2, 3, or 5 days. Significance shown for DMSO versus treatment for each timepoint. D, Raw nanoLuc and cell titer glo viability data from the IFI27 reporter screen showing relationships between cell viability and reporter activation. Aurora kinase inhibitors are circled. E, Major active drugs from IFI27 reporter screen, grouped by class and expressed as a ratio of nLuc/CTG. The median value of all compounds in the screen is overlaid as a red dashed line. F, Time course of reporter activation after alisertib treatment. Drugs were added as indicated and nanoluciferase activity of supernatants was assayed after the indicated number of days. Significance shown for DMSO versus treatment for each cell line at each timepoint (only day 5 achieved P < 0.05).