Fig. 6

Therapeutic effect of EP antagonists on TMZ-resistant glioblastoma. a, b Effect of EP1 antagonist, ONO-8713, or EP3 antagonist, ONO-AE3-240, on glioblastoma cells. The cells were treated with ONO-8713 or ONO-AE3-240 in the presence of TMZ and PGE2 for 96 h. Cell viability was determined via MTT assay. c TMZ-resistant glioblastoma cells treated with different compounds in the presence of TMZ for 96 h. Cell viability was determined by performing MTT assay. (# implies a significant difference compared with the TMZ-treated group). d After treatment with ONO-8713 for four days, cell lysates were prepared for Western blotting. e, f After treatment for 48 h, migratory and invasive activities of TMZ-resistant GBM cells were determined by wound-healing and transwell invasion assays, respectively. g, h Effect of ONO-8713 or celecoxib on the growth of TMZ-resistant cell-derived tumour in xenograft mouse model. The difference between the control and experimental groups was analysed by performing two-way ANOVA. The scale bar is 1 cm