Li J G, Ding Y, Huang Y M, Chen W L, Pan L L, Li Y, Chen X L, Chen Y, Wang S Y, Wu X N
Department of Hematology, Fujian Institute of Hematology, Fujian Medical University Union Hospital, Fuzhou, China.
Union Clinical Medical College, Fujian Medical University, Fuzhou, China.
Braz J Med Biol Res. 2017 May 4;50(6):e5661. doi: 10.1590/1414-431X20175661.
Burkitt lymphoma (BL) is a highly malignant non-Hodgkin's lymphoma that is closely related to the abnormal expression of genes. Familial acute myelogenous leukemia related factor (FAMLF; GenBank accession No. EF413001.1) is a novel gene that was cloned by our research group, and miR-181b is located in the intron of the FAMLF gene. To verify the role of miR-181b and FAMLF in BL, RNAhybrid software was used to predict target site of miR-181b on FAMLF and real-time quantitative PCR (RQ-PCR) was used to detect expression of miR-181b and FAMLF in BL patients, Raji cells and unaffected individuals. miR-181b was then transfected into Raji and CA46 cell lines and FAMLF expression was examined by RQ-PCR and western blotting. Further, Raji cells viability and proliferation were detected by MTT and clone formation, and Raji cell cycle and apoptosis were detected by flow cytometry. The results showed that miR-181b can bind to bases 21-42 of the FAMLF 5' untranslated region (UTR), FAMLF was highly expressed and miR-181b was lowly expressed in BL patients compared with unaffected individuals. FAMLF expression was significantly and inversely correlated to miR-181b expression, and miR-181b negatively regulated FAMLF at posttranscriptional and translational levels. A dual-luciferase reporter gene assay identified that the 5' UTR of FAMLF mRNA contained putative binding sites for miR-181b. Down-regulation of FAMLF by miR-181b arrested cell cycle, inhibited cell viability and proliferation in a BL cell line model. Our findings explain a new mechanism of BL pathogenesis and may also have implications in the therapy of FAMLF-overexpressing BL.
伯基特淋巴瘤（BL）是一种高度恶性的非霍奇金淋巴瘤，与基因的异常表达密切相关。家族性急性髓性白血病相关因子（FAMLF；基因银行登录号EF413001.1）是我们研究小组克隆的一个新基因，miR-181b位于FAMLF基因的内含子中。为了验证miR-181b和FAMLF在BL中的作用，使用RNAhybrid软件预测miR-181b在FAMLF上的靶位点，并使用实时定量PCR（RQ-PCR）检测BL患者、Raji细胞和未受影响个体中miR-181b和FAMLF的表达。然后将miR-181b转染到Raji和CA46细胞系中，通过RQ-PCR和蛋白质免疫印迹法检测FAMLF的表达。此外，通过MTT法和克隆形成检测Raji细胞的活力和增殖，通过流式细胞术检测Raji细胞周期和凋亡。结果显示，miR-181b可与FAMLF 5'非翻译区（UTR）的第21-42位碱基结合，与未受影响个体相比，BL患者中FAMLF高表达而miR-181b低表达。FAMLF的表达与miR-181b的表达呈显著负相关，且miR-181b在转录后和翻译水平上对FAMLF起负调控作用。双荧光素酶报告基因检测确定FAMLF mRNA的5'UTR包含miR-181b的假定结合位点。miR-181b下调FAMLF可使BL细胞系模型中的细胞周期停滞，抑制细胞活力和增殖。我们的研究结果解释了BL发病机制的一种新机制，也可能对FAMLF过表达的BL的治疗具有启示意义。
