For microarray-based miRNA analysis, we used the Human miRNA Microarray, Release 19.0, 8 × 60K array (Agilent Technologies, Santa Clara, CA, USA), capable of measuring 2042 mature human miRNAs. The miRNAs were isolated from neurospheres using the miRNeasy Mini Kit (Qiagen, Valencia, CA, USA), and labeled using the miRNA Complete Labeling Reagent and Hyb Kit (Agilent Technologies). Array hybridization was performed according to the manufacturer's instructions. The microarrays were then scanned in a High-Resolution C scanner (Agilent Technologies), and analyzed using GeneSpring GX (Agilent Technologies). The percentile shift method (90th percentile) was used to normalize the inter-microarray range of expression intensities. The P-values were calculated using Student's t-test (two-tailed) between data from patient (n=4) and control (n=4) groups.
