Fig. 8: AT3:VCP is a targetable functional dependency in cancer cells in vivo.
From: ASPSCR1-TFE3 reprograms transcription by organizing enhancer loops around hexameric VCP/p97
a Time to tumorigenesis (100 mm3 calculated size) of FUUR-1 cells, transfected and selected for IPTG-inducible shRNAs, xenografted into NRG mice (1 million cells per flank in Matrigel). Drinking water IPTG began on day 0, three days after xenograft injection. (n = 4 for each transfected population of cells, in which each shRNA has n = 3. Mean ± standard deviation, two-tailed homoscedastic t-test p-values. Open diamonds represent tumors <100 mm3 at 21 days, counted that days for statistics). b Growth curves for the same transfected xenografts (n = 12 per shRNA, mean ± standard deviation, two-tailed homoscedastic t-test p-value). c Final mass for each transfected xenograft tumor harvested (day 21, mean ± standard deviation, two-tailed homoscedastic t-test p-value). d Growth of FU-UR-1 xenografts (NRG mice) treated with CB-5083 at 100 mg/kg/day for 4 days per week versus vehicle control (harvested day 8, due to gavage toxicity) or at 50 mg/kg/day for 4 days per week versus vehicle control (n = 10 tumors per group; homoscedastic t-test p-values). e Immunofluorescence Ki-67 photomicrographs of FU-UR-1 xenografts harvested day 8 after treatment with 100 mg/kg CB-5083 or vehicle control, administered on days 1–4 and 8 (magnification bars, 50 µm). f Patient-derived xenograft growth data by luciferase activity on weekly measurements (n = 10, Tukey’s test p-values) g Fractional growth curves for individual tumors in genetically induced mouse ASPSs, randomized to treatments at volumes >10 mm3 by serial MRI (n = 13, CB-5083; n = 15, vehicle). h RT-qPCR for target genes (defined as mouse AT3-ChIP-seq targeted and having reduced expression of homologues in both FU-UR-1 and ASPS-1 cells with AT3 depletion) in control tumors (OS osteosarcoma, SS synovial sarcoma) or genetically induced mouse ASPS tumors treated with vehicle or CB-5083 for 50 mg/kg for 4 days prior to harvest. (n = 4 tumors per group per gene; homoscedastic two-tailed t-test p-values).
