目的 探讨miRNA-181a(miR-181a)在多发性骨髓瘤(MM)患者中的表达情况及其对MM细胞生物学特性的影响.方法 应用免疫磁珠筛选的方法分离并纯化25例初治、复发难治MM患者及10例非恶性血液病患者骨髓CD138+细胞,应用实时定量聚合酶链反应(qRT-PCR)检测miR-181a表达情况.同时检测RPMI 8226、H929及U266三种MM细胞株中miR-181a的表达.应用miR-181a抑制剂及激动剂观察下调和上调miR-181a表达对MM细胞生物学特性的影响,并对miR-181a进行靶基因预测.结果 与非恶性血液病患者相比,MM患者CD138+细胞中miR-181a表达上调.对MM细胞株的观察发现,与非恶性血液病患者骨髓CD138+细胞相比,RPMI 8226及U266细胞株miR-181a高表达,而H929细胞株则低表达.相比对照组,应用100 nmol/L miR-181a抑制剂下调miR-181a后,U266细胞的增殖活力在24、48及72 h分别为(50.5±4.1)%、(52.3±2.2)%和(69.5±4.3)%,低于对照组的(67.1±3.3)%、(71.5±3.6)%和(78.1±5.4)%(均P〈0.05),提示细胞增殖受抑.而应用100 nmol/L miR-181a激动剂上调miR-181a后,H929细胞在24、48 h时的增殖活力分别为(38.5±3.6)%和(82.2±6.9)%,高于对照组的(21.2±2.4)%和(61.3±5.4)%(均P〈0.01),提示细胞增殖增强.细胞周期分析提示,miR-181a抑制剂使U266细胞周期阻滞在G0/G1期.细胞药敏实验结果显示,多柔比星、紫杉醇及5-氟尿嘧啶作用后,与药物单独处理的细胞相比,miR-181a抑制剂下调U266细胞miR-181a表达的细胞增殖活力下降.在48 h和72 h的吸光度(A)值显著低于对照组.细胞迁移实验显示,miR-181a抑制剂下调miR-181a能抑制U266细胞的迁移能力,实验组细胞的迁移比例为(62±10)%,低于对照组的(89±12)%(P〈0.05),而miR-181a激动剂则能提高H929细胞的迁移能力,实验组细胞的迁移比例[(242±9)%]高于对照组的(98±8)%(P〈0.01).结论 MM细胞高表达miR-181a.miR-181a的高表?
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 migr