A preliminary study on the effect of miRNA-181a on biological features of multiple myeloma cells / 白血病·淋巴瘤

ABSTRACT

Objective To explore the expression of miRNA-181a (miR-181a) in patients with multiple myeloma (MM) and its effect on biological features of MM cells. Methods CD138+cells of bone marrow from 25 MM patients and 10 patients with hematological non-malignancies were purified by using immunomagnetic separation, and the expression of miR-181a in CD138+cells and MM cell lines including RPMI 8226, H929 and U266 were detected by real-time quantitative PCR. The effects of down-regulation and up-regulation of miR-181a expression on the biological characteristics of MM cells were studied with miR-181a antagomir and agomir. Results Compared with patients with hematological non-malignant diseases, the expression of miR-181a in CD138+ cells was upregulated in MM patients. Compared with CD138+ cells in hematological non-malignancies, high expressions of miR-181a were observed in RPMI 8226 and U266 myeloma cell line, while low expressions of miR-181a were observed in H929 cells. Down-regulation of miR-181a with 100 nmol/L miR-181a antagomir could inhibit the proliferation of U266 cells at 24,48 and 72 h [(67.1 ± 3.3) %vs. (50.5 ± 4.1) %, (71.5 ± 3.6) % vs. (52.3 ± 2.2) %, (78.1 ± 5.4) % vs. (69.5 ± 4.3) %, P < 0.05 respectively], whereas up-regulation of miR-181a with 100 nmol/L miR-181a agomir could significantly promote the proliferation of H929 cells at 24 h and 48 h [(21.2 ± 2.4) %vs. (38.5 ± 3.6) %, ( 61.3 ± 5.4) %vs. (82.2 ±6.9)%, P<0.01 respectively]. Cell cycle analysis showed that miR-181a antagomir made U266 cell cycle arrest in the G0/G1 phase. Meanwhile, susceptibility test results indicated that the apoptosis of U266 cells induced by doxorubicin, paclitaxel and 5-fluorouracil was increased when the proliferation of miR-181a expression was down-regulated with miR-181a antagomir. In migration assay, the data showed that down-regulation of miR-181a with miR-181a antagomir could inhibit the migration of U266 cells, and the proportion of migrated cells in the experimental group (62 ± 10) %was lower than that in the control group (89 ± 12) %(P< 0.05), whereas up-regulation of miR-181a with miR-181a agomir could improve the migration of H929 cells, and the proportion of migrated cells in the experimental group (242 ± 9) % was higher than that in the control group (98 ± 8)%(P<0.01). Conclusions The high expression of miR-181a expressed highly by MM cells may promote the proliferation, migration and drug resistance of myeloma cells, indicating that miR-181a could be an important prognostic biomarker candidate, and the application of gene silencing may improve the prognosis of MM.