Identification of aberrant miRNA expression in multiple myeloma

To identify aberrant miRNAs involved in the pathogenesis of multiple myeloma, we performed miRNA expression profiling of a total of 27 samples consisting of 19 clinical specimens, 8 myeloma cell lines and 3 normal peripheral blood samples. The microarray data were analysed by GeneSpring Software v13.0. We had identified 1799 miRNAs, which were differentially expressed by >2.0 fold change at p<0.05. Out of 1799 miRNAs, 1791 and 8 of them were up-regulated and down-regulated, respectively in myeloma group compared to the normal control group. Expression of 2 miRNAs (miR-150-5p and miR-4430) were verified by real-time PCR using the same RNA samples (20-22 samples were used) using SYBR Green. The real-time PCR confirmed that the expression of the miRNAs were consistent with microarray data. Bone marrow aspirates of 19 clinical specimens and 8 myeloma cell lines were compared against 3 peripheral bloods from healthy individuals.