Fig. 7: PA2G4 suppression alters 3q26 AML proliferation in vivo.

A Effects of WS6 treatment on viability in primary 3q26 AML samples following 72 hr of drug treatment. B Effect of WS6 in EVI1^High (samples PR#002 - 006, PR#008 and PR#023 - 024) and EVI1^Low (samples PR#025-039) primary AML samples. The AUC model of the log-transformed dose-response data is depicted. C Effects of WS6 treatment compared to control (DMSO) on viability in primary 3q26 AML samples following 72 hr of drug treatment. Left: H&E of PR#005 bone marrow cells in 3D cell culture after 72 hr of treatment with vehicle (DMSO) or WS6 at 1/2 IC₅₀ and IC₅₀ concentrations. Scale bar: 40 µm. Right: histograms indicate the fraction of viable cells expressed as a percentage relative to control. D PA2G4, EVI1, ∆EVI1, and MYC and cleaved caspase 3 protein expression in primary 3q26 AML samples following 24 h of treatment with the vehicle (DMSO) or WS6 at the indicated concentrations. E Effect of WS6 (50 mg/kg) on EVI1 nuclear localization (in red) following 6 hr of treatment in PDLX_PR#009 (n = 3 biological replicates). Nuclei in blue (DAPI). Scale bar: 100 µm. Histograms indicate the fluorescence intensity of EVI1 nuclear content before and after treatment. F In vivo antileukemic effect of WS6. On the top the draft of the experiments. Mice were treated with vehicle (DMSO) or 25 mg/Kg WS6 for 5 days/week for 15 days. On the bottom-left dot plot showing the number of hCD45+ cells expressed as the percentage difference of BM leukemic cells at T1 (endpoint-day 15) vs. T0 (pre-treatment-day 0) normalized for T0 in control (n = 7) and WS6-treated PDLX_PR#003 (n = 6). On the bottom-right the dot plot shows the percentage of hCD45+ cells in the bone marrow between vehicle (n = 4) or WS6-treated PDLX_PR#008 (n = 5) at the endpoint. Events ≥ 20.000. G UMAP plot of clustering results of PDLX_PR#003 hCD45 bone marrow–positive cells before (left panel) and after (right panel) 15 days of WS6 treatment (25 mg/kg/IP/5 days a week), color-coded according to the UCell score of leukemic markers (MECOM, MYC, CD45, CD34, KIT, CD33, ANPEP, CD38, CD2, TFRC, HLA-DRA, HLA-DRB1, and HLA-DRB5). H EVI1, MYC, and Ki67 expression in PDLX_PR#003 after 15 days of WS6 treatment (25 mg/kg/IP/5 days a week) or vehicle (DMSO). Scale bar: 100 µm. Histograms to the right indicate the mean ± SD of the percentage of the EVI1, MYC, or Ki67-positive cells in FFPE tissue sections. Statistical significance was determined by a two-tailed non-parametric t-test (Mann-Whitney) (B, E, F, H). Data are presented as mean ± SD in A (n = 2), B (EVI1^High n = 8, EVI1^Low n = 15), C (n = 2), in E (n = 125), F (vehicle PDLX_PR#003 n = 7, treated PDLX_PR#003 n = 6, vehicle PDLX_PR#008 n = 4, treated PDLX_PR#008 n = 5) and H (vehicle n = 7, treated n = 6; n = 10 fields per condition). Source data are provided as a Source Data file. See also Supplementary Fig. 11.