RESUMO
<p><b>OBJECTIVE</b>To detect the expression level of miR-19a, one of the oncogenic miR-17-92 cluster, in multiple myeloma cell lines Lp-1 and U266 in vitro and to explore the effects of miR-19a on biological behavior, such as proliferation, migration and apoptosis of Lp-1 and U266 myeloma cells by transfection with miR-19a mimic through Lipofectamine2000.</p><p><b>METHODS</b>The reverse transcription-PCR was applied to detect the expression level of miR-19a in multiple myeloma cell lines Lp-1 and U266 in vitro. The CCK8 was used to assay the effect of miR-19a on the proliferation of Lp-1 and U266 cells in vitro, the transwell migration test was adopted to determine the effect of up-regulation of miR-19a on the migration of Lp-1 and U266 multiple myeloma cells in vitro. The flow cytometry was used to detect the effect of miR-19a on the apoptosis of Lp-1 and U266 cells in vitro.</p><p><b>RESULTS</b>The miR-19a expression was higher in Lp-1 and U266 multiple myeloma cells; compared with the transfected cells with a specific miR-19a NC, those samples transfected with miR-19a mimic displayed significantly higher expression of miR-19a (P<0.05), indicating a higher transfection efficiency; the miR-19a could promote the proliferation of Lp-1 and U266 multiple myeloma cells in vitro. MiR-19a could promote migration ability of Lp-1 and U266 multiple myeloma cell lines in vitro and could inhibit the apoptosis of Lp-1 and U266 cells.</p><p><b>CONCLUSION</b>miR-19a is overexpressed significantly in Lp-1 and U266 multiple myeloma cells, and promots the proliferation and invasion of the myeloma cells, but inhibits their apoptosis.</p>