MiR-124 inhibits proliferation of CDK6-expressing D425 medulloblastoma cells and induces G0/G1 cell cycle arrest miR-124. (A) Cell numbers were determined at 72 h after transfection of 100 nM miR-124 or negative control oligonucleotides to D283, D341, and D425 medulloblastoma cells. Values represent mean ± SD of replicate experiments normalized to the cell count in the control samples (D283 n = 51; D341 n = 34; D425 n = 14). Differences between miR-124 and control transfected cells were analyzed using Student's t-test; *P < .05. **P < 2e-7. ***P < 4e-15. (B) Cell cycle analysis conducted by fluorescence-activated cell sorter (FACS) at 48h after transfection of 100 nM miR-124 or negative control oligonucleotides to D425 cells. Cells were treated with BrdU for 30 min, fixed, treated with fluorescein isothiocyanate (FITC)–labeled anti-BrdU antibody and the DNA stain 7-amino-actinomycin D, and subjected to flow cytometry. Values represent mean ± SD (n = 2) of replicate experiments (n = 3). Differences between miR-124 and control transfected cells were analyzed using Student's t-test; *P < .0005; **P < 2e-6. (C) Cell cycle analysis was conducted by FACS at 48 h after transfection of 100 nM CDK6 siRNAs, miR-124, or negative control oligonucleotides to D425 cells. Cells were treated with BrdU for 30min, fixed, treated with FITC-labeled anti-BrdU antibody and the DNA stain 7-amino-actinomycin D, and subjected to flow cytometry. Values represent mean ± SD (n = 2) of replicate experiments (n = 3). Differences between the different transfections were analyzed using Student's t-test; *P < 3e-6. (D) Cell cycle analysis was conducted by FACS at 48 h after transfection of 100 nM CDK6 siRNAs, miR-124, or negative control oligonucleotides to D283 cells. Values represent mean ± SD (n = 2) of replicate experiments (n = 3). Differences between the different transfections were analyzed using Student's t-test; *P < .0001.