Abstract 2333: TRAIL-inducing imipridones ONC201, ONC206, and ONC212 demonstrate anti-neoplastic effects in colonic adenoma-derived organoids

Background: Colorectal cancer (CRC) is the second leading cause of cancer-related death in the United States. Currently, screening is the most effective method to reduce mortality from CRC. Chemoprevention, which aims to delay or even prevent the onset of CRC through eradication or prevention of precursor colonic adenomas, is an alternative strategy to address this problem. The imipridone Dordaviprone/ONC201 is a potential chemopreventive agent that has been shown to induce apoptosis in cancer cells through both upregulation of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and the integrated stress response. More recently, we have shown that ONC201 induces TRAIL and apoptosis in a dose-dependent manner in adenoma-derived organoids and reduces adenoma formation in the Apcmin/+ CRC mouse model. We hypothesized that ONC201’s analogues, ONC206 and ONC212, would similarly enhance human colonic adenoma cell death through both TRAIL-dependent and TRAIL-independent mechanisms. We therefore evaluated the effects of ONC206 and ONC212 in two adenoma-derived organoid lines: one developed from an adenoma from an individual with familial adenomatous polyposis (FAP) and the second from a sessile serrated adenoma (SSA). Methods: Sensitivity of the FAP and SSA organoid lines to ONC206 and ONC212 was assessed using CellTiter-Glo® luminescent cell viability assay. Organoids were plated in triplicates and treated with ONC206 and ONC212 (concentration ranging from 0 uM to 10 uM). Results were analyzed after 72 hours of incubation. Western blotting was performed on lysates generated from both FAP and SSA organoids treated with either DMSO, ONC206, or ONC212 for 24, 48, or 72 hours. Co-culture experiments were performed with the adenoma-derived organoids (dyed using blue CMAC dye) and human NK-92MI cells (dyed with green CMFDA dye) treated with either DMSO, ONC201, ONC206, or ONC212. Fluorescent images following administration of red live/dead dye were performed using DAPI, FITC, and cherry red channels on ImageXpress® at 0, 24, 48, and 72 hours. Results: ONC206 and ONC212 demonstrated antineoplastic effects on adenoma-derived FAP and SSA organoids, with half maximal inhibitory concentrations (IC50) less than that of ONC201 in FAP and SSA organoids. As was noted in ONC201 studies, the mechanism of action of ONC206 and ONC212 appears to be mediated through modulation of multiple pathways including the TRAIL pathway (TRAIL and DR5 upregulation) and the integrated stress responses (ATF4 upregulation). Co-culture with NK cells revealed a significant increase in NK-mediated organoid cell death. The ability of ONC206 and ONC212 to enhance NK-mediated killing is being evaluated. Further analysis of the effects of ONC206 and ONC212 on stemness markers are currently underway and may reveal other potential biomarkers and chemopreventive strategies for ONC206 and ONC212. Citation Format: Alexis J. Lannigan, Jasper Chan, Lanlan Zhou, Varun V. Prabhu, Michael Dame, Dean Brenner, Jason Spence, Wafik S. El-Deiry, Alexander G. Raufi. TRAIL-inducing imipridones ONC201, ONC206, and ONC212 demonstrate anti-neoplastic effects in colonic adenoma-derived organoids [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 2333.