Fig. 3From: Development of a human in vitro blood–brain tumor barrier model of diffuse intrinsic pontine glioma to better understand the chemoresistanceImpact of other DIPG cell lines on the physical and metabolic properties of the BBB. a Endothelial paracellular permeability (Pe) to Lucifer Yellow after 24 h, 72 h and 7 days of incubation with astrocytes (control), DIPG-013 cells or DIPG-014 cells. Pe = endothelial permeability coefficient. N = 3; n = 9. ns = non significant. b Representative images of tight junction protein immunostainings of zonula occludens-1 (ZO-1) and claudin-5 after 7 days of incubation. Scale bar = 25 µm. c Transcriptional expression of the genes of efflux transporters P-gp, BCRP, MRP1 and MRP2, after 7 days of incubation, quantified by RT-qPCR and normalized on the expression of the housekeeping gene PPIA (cyclophilin A). ***p < 0.001; *p < 0.05. N = 2; n = 6. d Protein level of efflux transporters P-gp and BCRP, after 7 days of incubation, quantified by Western blot and normalized on the protein level of β-actin. Results were obtained from two independent experiments (N = 2). ns = non significant. e P-gp and BCRP activity, evaluated by the measure of P-gp/BCRP substrate rhodamine 123 (R123) accumulation in ECs, with or without the P-gp/BCRP inhibitor elacridar, after 7 days of incubation. N = 2; n = 6Back to article page