1. ONC201 activates the ISR.
ONC201 activates the ISR. (A) Western blotting analysis for ATF4, CHOP, ATF3, and TRB3 on lysates from HCT116 cells cultured with ONC201 (0 to 10 μM) for 3 to 24 hours. BFA (an ER stressor) served as a positive control. Blots are representative of two experiments. (B) Quantitative reverse transcription polymerase chain reaction (qRT-PCR) for the expression of CHOP and DR5 relative to GAPDH in HCT116 cells treated with ONC201 (10 μM) or vehicle for 24 or 48 hours. (C) Immunohistochemical analysis for CHOP in HCT116-derived subcutaneous xenografts from mice that received either vehicle (−) or ONC201 (+; 25 mg/kg). Results are representative of tissues from two vehicle-treated mice and six mice intraperitoneally or intravenously injected with ONC201 (three mice each). Scale bars, 10 μm. (D) Western blotting analysis for CHOP in lysates from colorectal cancer stem cell–like cell-derived xenografts (45) in athymic nude mice extracted 72 hours after treatment [vehicle or ONC201 (50 mg/kg, intraperitoneally)]. Tumor lysates from untreated mice (−) served as controls. (E) Densitometric analyses of the bands in the Western blots in (D). (F) qRT-PCR for the fold change in expression of CHOP and DR5 relative to GAPDH in different cell types cultured with ONC201 (compared to vehicle) for 72 hours. Data in (B), (E), and (F) are means ± SEM of three biological replicates. *P < 0.05, Student’s t test with Holm-Sidak correction, comparing ONC201-treated versus vehicle-treated cells.
C. Leah B. Kline et al., Sci. Signal. 2016;9:ra18
Copyright © 2016, American Association for the Advancement of Science