Fig. 5

PRLR confers chemoresistance to AML. A PRLR and Stat5a mRNA expression at diagnosis (blue) and relapse (red) in AML patients from GSE66525 database. *p < 0.05 (unpaired t test). B AML cell lines were treated for 72 h with cytarabine (AraC) at the indicated doses. Viability was assessed by flow cytometry and a representative result was shown. The EC50 values were correlated with the PRLR surface expression analysed by flow cytometry. *p < 0.05 (simple linear regression, triplicates). Green, HL-60; Red, SKM-1; Blue, U-937; Black, MonoMac-1 (MM); Brown, KG-1. C PRLR-transduced (orange), PRL-transduced (orange) and control (black) MonoMac-1 (MM) cells were treated with AraC for 72 h. Viability was analysed by flow cytometry and representative results were shown (n = 3). D PRLR expression in AraC-resistant (AraC R, red) and the parental (grey) cell lines HL-60 and SKM-1 were analysed by flow cytometry (protein surface expression) and western blot (total protein level). *p < 0.05; **p < 0.01 (paired t test, triplicates). E Expression of genes associted to cytarabine transporters (green), activators (blue) and inactivators (yellow and purple) were determined by qPCR in PRLR wt-tranduced HL-60 and SKM-1 cells and compared to parental cells. *p < 0.05 (one-way ANOVA, Dunnett’s multiple comparison test, triplicates). In all graphs, bars represent the mean ± SEM