MicroRNAs 130a/b are regulated by BCR-ABL and downregulate expression of CCN3 in CML
MicroRNAs 130a/b are regulated by BCR-ABL and downregulate expression of CCN3 in CML
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DOI：
10.1007/s12079-011-0139-x
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发表时间：
2011-08-01
影响因子：
4.1
通讯作者：
Irvine, Alexandra E.
中科院分区：
文献类型：
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作者：
Suresh, Sukanya;McCallum, Lynn;Irvine, Alexandra E.
慢性髓系白血病(CML)是一种以癌蛋白bcr-abl激酶表达为特征的骨髓增生性疾病。CCN3通常作为负生长调节因子发挥作用，但在慢性粒细胞白血病中表达下调，其机制尚不清楚。MicroRNAs(MiRNAs)是一种小的非编码RNA，通过与信使RNAs的3‘非编码区互补序列结合，负向调节蛋白质的翻译。不受调控的miRNA表达已成为癌症的一个标志。在CML中，BCR-ABL上调致癌的miRNAs，下调有利于白血病转化的肿瘤抑制因子miRNAs。我们在这里报道，CML中CCN3的下调是由依赖BCR-ABL的miRNAs介导的。利用CML细胞株K562，我们用抗bcr-abl siRNA转染K562细胞，获得了依赖bcr-abl的miRNAs。利用Taqman低密度miRNA阵列平台对miRNA表达水平进行定量。从miRNA靶标预测数据库中，我们发现了可能与CCN3mRNA结合并降低表达的miRNAs。其中miR-130a、miR-130b、miR-148a、miR-212和miR-425-5p在bcr-abl基因敲除后显著降低，其中miR-130a和miR-130b在siRNA处理后24 h内下降幅度最大。将miR-130a和miR-130b成熟序列分别导入bcr-abl阴性的HL60细胞后，CCN3mRNA和蛋白表达均下降。当miR-130a过表达时，CCN3的下调幅度最大，而miR-130b过表达仅导致CCN3的边缘抑制。本研究表明miRNAs调控CCN3的表达。Bcr-abl启动的miRNA表达失控可能是白血病细胞逃避负生长调控而下调CCN3的机制之一。
Chronic Myeloid Leukaemia (CML) is a myeloproliferative disorder characterized by the expression of the oncoprotein, Bcr-Abl kinase. CCN3 normally functions as a negative growth regulator, but it is downregulated in CML, the mechanism of which is not known. MicroRNAs (miRNAs) are small non-coding RNAs, which negatively regulate protein translation by binding to the complimentary sequences of the 3' UTR of messenger RNAs. Deregulated miRNA expression has emerged as a hallmark of cancer. In CML, BCR-ABL upregulates oncogenic miRNAs and downregulates tumour suppressor miRNAs favouring leukaemic transformation. We report here that the downregulation of CCN3 in CML is mediated by BCR-ABL dependent miRNAs. Using the CML cell line K562, we profiled miRNAs, which are BCR-ABL dependent by transfecting K562 cells with anti-BCR-ABL siRNA. MiRNA expression levels were quantified using the Taqman Low Density miRNA array platform. From the miRNA target prediction databases we identified miRNAs that could potentially bind to CCN3 mRNA and reduce expression. Of these, miR-130a, miR-130b, miR-148a, miR-212 and miR-425-5p were significantly reduced on BCR-ABL knockdown, with both miR-130a and miR-130b decreasing the most within 24 h of siRNA treatment. Transfection of mature sequences of miR-130a and miR-130b individually into BCR-ABL negative HL60 cells resulted in a decrease of both CCN3 mRNA and protein. The reduction in CCN3 was greatest with overexpression of miR-130a whereas miR-130b overexpression resulted only in marginal repression of CCN3. This study shows that miRNAs modulate CCN3 expression. Deregulated miRNA expression initiated by BCR-ABL may be one mechanism of downregulating CCN3 whereby leukaemic cells evade negative growth regulation.