Fig. 5
P53-miR-29a-MDM2 positive feedback loop sensitized the response of glioma cells to temozolomide. A, B After using a serial concentration of TMZ to treat glioma cells with miR-29a mimic, inhibitor or corresponding control transfection, cell viability was detected by CCK-8 assay. C IC50 for TMZ was determined in glioma cells mentioned above. Results show the mean ± SD (n = 3). *P < 0.05; **P < 0.01. D, E After MDM2 knockdown followed by miR-29a inhibitor treatment, cell viability was detected by CCK-8 assay; meanwhile IC50 for TMZ was determined in these cells (F). *P < 0.05 vs control; #P < 0.05 vs miR-29a inhibitor. U87 cells stably expressing miR-C (control), miR-29a, or miR-29a-I (inhibitor) were resuspended in 200 μL of FBS-free DMEM medium and then subcutaneously injected into each side of the posterior flanks of nude mice (n = 6). The tumor growth curve in vivo was analyzed (G). Furthermore, tumor tissues from patients receiving TMZ treatment and achieving a better response and from patients receiving TMZ treatment but without a response were collected for the evaluation of miR-29a, p53 and MDM2 expression by RT-PCR and IHC (H)