a Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University , Suzhou , People's Republic of China.
b Collaborative Innovation Center of Hematology, Soochow University , Suzhou , People's Republic of China.
Ups J Med Sci. 2018 Mar;123(1):19-27. doi: 10.1080/03009734.2018.1440037. Epub 2018 Mar 1.
Emerging evidence has revealed that miRNAs can function as oncogenes or tumor suppressor genes in leukemia. The ectopic expression of miR-130a has been reported in chronic leukemia, but our understanding of the biological implications of miR-130a expression remains incomplete.
We quantified a cohort of de novo acute myeloid leukemia (AML) by bead-based miRNA and real-time quantitative PCR (Rq-PCR). The luciferase reporter gene assay was analyzed after the plasmid constructs which contain 5'-UTR of miR-130a and a Renilla luciferase reporter plasmid were transfected simultaneously into 293T cells. MTT and caspase 3/7 apoptosis assays were used to test cell viability and apoptosis.
We identified miR-130a as significantly overexpressed in t(8;21) AML. Expression of miR-130a decreased significantly once patients with t(8;21) achieved complete remission, but increased sharply at the time of relapse. In patients with t(8;21) AML, KIT mutational status was associated with miR-130a expression-with higher expression associated with KIT activating mutations. Increased miR-130a expression in t(8;21) AML was associated with slightly worse event-free survival; however, no impact on overall survival was observed. Knockdown of AML1/ETO protein in the SKNO-1 cell line resulted in decrease of expression of miR-130a. Direct binding of AML1/ETO fusion protein with the promoter sequence of miR-130a was detected with luciferase reporter gene assay. Following miR-130a knockdown, SKNO-1 demonstrated increased sensitivity to etoposide.
Our data suggest that miR-130a is directly activated by AML1/ETO, and may act as a factor which is associated with leukemia burden, event-free survival, and chemotherapy sensitivity in t(8;21) AML.
新出现的证据表明，miRNAs 可以在白血病中作为癌基因或肿瘤抑制基因发挥作用。miR-130a 的异位表达已在慢性白血病中报道，但我们对 miR-130a 表达的生物学意义的理解仍不完整。
我们通过基于珠子的 miRNA 和实时定量 PCR（Rq-PCR）对一组新诊断的急性髓系白血病（AML）进行了定量。将包含 miR-130a 5'-UTR 的质粒构建体与海肾荧光素酶报告质粒同时转染 293T 细胞后，分析荧光素酶报告基因检测。MTT 和 caspase 3/7 凋亡检测用于测试细胞活力和凋亡。
我们发现 miR-130a 在 t(8;21) AML 中显著过表达。一旦 t(8;21)患者达到完全缓解，miR-130a 的表达显著降低，但在复发时急剧增加。在 t(8;21)AML 患者中，KIT 突变状态与 miR-130a 表达相关-较高的表达与 KIT 激活突变相关。t(8;21)AML 中 miR-130a 表达的增加与无事件生存时间略差相关；然而，未观察到对总生存的影响。在 SKNO-1 细胞系中敲低 AML1/ETO 蛋白导致 miR-130a 的表达降低。通过荧光素酶报告基因检测检测到 AML1/ETO 融合蛋白与 miR-130a 启动子序列的直接结合。miR-130a 敲低后，SKNO-1 对依托泊苷的敏感性增加。
我们的数据表明，miR-130a 被 AML1/ETO 直接激活，并且可能作为与 t(8;21)AML 中的白血病负担、无事件生存和化疗敏感性相关的因素发挥作用。
