Identification of miRNAs associated with tumorigenesis of retinoblastoma by miRNA microarray analysis

MicroRNAs (miRNAs) are small (a1/222 nucleotides) regulatory RNAs which play fundamental roles in many human diseases, including cancer. There is no report on the miRNA expression profile of retinoblastoma. This work was undertaken to identify differentially expressed miRNAs in human retinoblastoma tissues by microRNA microarray technique, and some miRNAs were verified using northern blot analysis and the in situ hybridization method. A cluster of microRNAs was identified as highly expressed in retinoblastoma, including hsa-miR-494, hsa-let-7e, hsa-miR-513-1, hsa-miR-513-2, hsa-miR-518c*, hsa-miR-129-1, hsa-miR-129-2, hsa-miR-198, hsa-miR-492, hsa-miR-498, hsa-miR-320, hsa-miR-503, and hsa-miR-373*. These miRNAs are the first to be reported for human retinoblastoma and may play significant roles in regulating tumor genesis.