TIC9 and ONC201/TIC10 induce TRAIL gene transcription and surface TRAIL upregulation in tumor cells in vitro. (a) Reporter activity in HCT116 Bax−/− cells that stably express a luciferase gene reporter construct under transcriptional control of the first 504 base pairs of the human TRAIL gene promoter (n = 3). Reporter signal is expressed relative to DMSO-treated cells and normalized to cell viability. (b) RT-qPCR analysis of TRAIL gene transcription in response to TRAIL-inducing compounds (TICs) (5 μM) in HCT116 p53−/− cells (n = 4, 48 hr). (c) Flow cytometry analysis of surface TRAIL in response to TICs (5 μM) in HCT116 p53−/− cells (n = 3, 72 hr). *P < .05 by student’s two-tailed t test. Error bars represent standard deviation.