(A, B) Representative results of FACS side scatter analysis (top), and percentage (mean ± SD, n=3) (bottom) of ALDH(+) cells in OVCAR5 (A) and SKOV3 (B) OC cells treated with DMSO or NTX-301 (10nM and 100nM, 3 days). (C, D) Effects of NTX-301 (10nM and 100nM, 3days) on spheroid formation assessed by measuring cell viability in OVCAR5 (C) and SKOV3 (D) cells (n = 4–6 per dose). (E) Western blot measured protein levels of DNMT1, Sox2, ALDH1A1, and beta actin (loading control) in SKOV3 and OVCAR5 cells treated with DMSO or NTX-301 for 3 days (n=2). (F, G) mRNA expression levels of SOX2 measured by qRT-PCR (n=3–4) in SKOV3 (F) and OVCAR5 (G) cells treated with DMSO or NTX-301 (100nM, 3days). (H-K) Tumor bearing SQ xenografts were treated with PBS or carboplatin (40mg/kg weekly, 3-weeks) before being randomly assigned to receive NTX-301 (1.0 mg/kg) or diluent. Effects of carboplatin on tumor volume (H) and NTX-301 on tumor weight (I) and tumor volume (J) (n=6/group). (K) mRNA expression levels of ALDH1A1 measured by qRT-PCR in xenografts (n=5, 6) after treatment with diluent or NTX-301 as described in (H). Carbo, carboplatin. For all comparisons, *p<0.05, **p<0.01, ***p<0.001.