Fig. 3: Absence or therapeutic blockade of E-selectin sensitizes AML LRCs to chemotherapy and extends duration of disease-free survival in mice. | Nature Communications

Fig. 3: Absence or therapeutic blockade of E-selectin sensitizes AML LRCs to chemotherapy and extends duration of disease-free survival in mice.

From: Endothelial E-selectin inhibition improves acute myeloid leukaemia therapy by disrupting vascular niche-mediated chemoresistance

Fig. 3

a, b AML cells or non-leukemic Kit+ HSPC from mouse BM were cultured for 3 days with Ara-C in wells precoated with adhesion molecules as indicated. In some wells, E-selectin blocking antibody RME-1 or isotype control added. a Plotted are percentage cell survival compared to matched non-chemotherapy-treated wells. Mean ± SD of pooled data from two experiments (n = 4,10,10,14,14,8,9,9 wells/condition). Statistics: one-way ANOVA multiple comparisons Bonferroni correction. b Histogram showing survival of Kit+ AML cells (top panel) compared to healthy (non-leukemic) HSPC (bottom panel) after Ara-C treatment in vitro. Shown as fold-change compared to control (BSA) wells. Mean ± SEM of pooled data from 4 (HSPC) or 5 (AML blasts) independent experiments (n = 5 wells/condition/experiment). Statistics: one-way ANOVA multiple comparisons Bonferroni correction. ce Experimental outline. Mice with advanced MLL-AF9 AML were administered ±GMI-1271 40 mg kg−1 BiD, for 5 days prior to and during 24 h chemotherapy (900 mg kg−1 BiD Ara-C) in wildtype or Sele−/− hosts as indicated. The number of surviving leukemia repopulating cells (LRC) then measured by serial-dilution transplantation of 1%, 0.1%, 0.01% total BM from one femur (n = 5 donors, n = 5 recipients per cell dose). Surviving number of LRC per femur and statistical comparison analysis calculated by Poisson distribution statistics using L-calc software. Shown is calculated LRC per femur ±95% CI. Degrees Freedom 2. c LRC per femur in wildtype versus Sele−/− hosts ±95%CI. d LRC per femur in saline vs. GMI-1271-treated mice ±95%CI. e Frequency regression of AML-negative recipients from (d) as function of transplanted BM cell number. Vehicle injected (black line), GMI-1271-treated mice (red line). Non-chemotherapy treated-mice (blue line). Horizontal dotted gray line is 37.5% threshold used for determining LRC frequency. f Wildtype mice with AML were administered GMI-1271 40 mg kg−1 BiD or saline before and during 5-day induction chemotherapy regimen (doxorubicin 1 mg kg−1 3 d and Ara-C 100 mg kg−1 5 d) and monitored for duration of disease-free survival. Shown is Kaplan Meier curve (n = 8 mice/group). Statistics: Log Rank (Mandel–Cox) survival curve comparison. Source data are provided as a Source Data file.

Back to article page