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Supplementary Figures 1-9, Supplementary Tables 1-3 from An Integrated Stress Response Agent that Modulates DR5-Dependent TRAIL Synergy Reduces Patient-Derived Glioma Stem Cell Viability

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journal contribution
posted on 2023-04-03, 16:42 authored by Saad Sheikh, Deeksha Saxena, Xiaobing Tian, Ahmad Amirshaghaghi, Andrew Tsourkas, Steven Brem, Jay F. Dorsey

S1: Raw bioluminescence data obtained from screens of kinase, protease, and redox inhibitors. S2: Bioluminescent and viability data from U251 DR5 Luciferase cells treated with an NH125 dilution series. S3: Representative images of T4213 neurospheres taken under 40X magnification demonstrate that T4213 enrich for CD133 (red) SOX2 (orange) and Nestin (green) (scale bar = 25 microns). S4: Representative phase contrast images of TMZ, and NH125 treated GSC taken under 10X magnification (scale bar = 100 microns). S5: Caspase 3/7 activity increases in NH125 treated GSC. GSC were incubated with either 0 M NH125 (0.1% DMSO) or 5 M NH125 for twenty-four hours followed by addition of Caspase 3/7 Glo. S6: NH125 leads to a dose dependent increase in markers of apoptosis. S7: GSC that acquire a differentiated morphology are less sensitive to NH125. S8: The ten most significant canonical pathways from analysis of the transcriptional data of NH125 treated U251 and NHA. S9: PEG-PCL-NH125 treatment of U251 leads to an increase in CHOP and DR5 expression in vitro. Table S1: Knockout of CHOP leads to an abrogation of NH125 mediated TRAIL synergy. Table S2: IC50 values from a panel of NH125 treated cells. Table S3: Addition of low dose TRAIL leads to increased synergy in glioma stem cells.

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NIH

NINDS

NCI

Burroughs Wellcome Fund

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ARTICLE ABSTRACT

The high incidence of glioblastoma recurrence necessitates additional therapeutic strategies. Heterogeneous populations of cells, including glioma stem cells (GSC) have been implicated in disease recurrence. GSCs are able to survive irradiation and temozolomide (TMZ) treatment due to upregulation of DNA damage pathways. One potential strategy to target treatment-resistant tumor populations may be via the integrated stress response (ISR). Modulation of the ISR pathway also allows for sensitization of treatment-resistant cells to TRAIL. We generated a novel cell-based death receptor assay to identify potent inducers of ISR-dependent DR5 expression. We used this assay to screen compounds from three commercially available libraries, and identified 1-benzyl-3-cetyl-2-methylimidazolium iodide (NH125) as a potent inducer of DR5 expression. NH125 engages the EIF2α–ATF4–CHOP axis culminating in DR5 expression at low micromolar doses. Expression of CHOP plays a critical role in NH125-mediated TRAIL synergy. Treatment of GSC with NH125 produces a marked reduction in viability when compared with other cell lines. NH125-treated GSC also synergize with lower doses of TRAIL when compared with all other cell lines tested. Transcriptional analysis of NH125-treated GSC uncovers a unique profile that involves activation of ISR and GADD45 pathways. Treatment of GSC xenografts with encapsulated PEG–PCL–NH125 leads to a sustained decrease in tumor volume. Taken together, these data suggest that engaging the ISR pathway represents a promising strategy to target treatment refractory GSC that have been implicated in glioblastoma recurrence.