Systematic evaluation of microRNA processing patterns in tissues, cell lines, and tumors
Systematic evaluation of microRNA processing patterns in tissues, cell lines, and tumors
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DOI：
10.1261/rna.804508
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发表时间：
2008-01-01
期刊：
影响因子：
4.5
通讯作者：
Schmittgen, Thomas D.
中科院分区：
文献类型：
--
作者：
Lee, Eun Joo;Baek, Myungwon;Schmittgen, Thomas D.
关于microRNA(MiRNA)在正常组织、肿瘤和细胞系中的生物发生调控，人们知之甚少。在这里，我们用实时荧光PCR技术研究了225个前体和成熟miRNAs的表达情况，并比较了表达水平，以确定加工模式。对22个不同的人体组织、37个人类癌细胞系和16个胰腺和肝脏组织/肿瘤的RNA进行了分析。前体和成熟miRNA表达之间的关系可分为以下四种类型：(1)前体和成熟miRNA表达之间存在直接相关性；(2)前体和成熟miRNA存在直接相关，但仅限于特定的细胞系或组织表达；(3)成熟miRNA在某些细胞和组织中可检测到表达，而前体在所有或大多数细胞/组织中表达；或(4)前体和成熟miRNA均不表达。对于组织来说，前体miRNA和成熟miRNA表达之间的皮尔逊相关性更接近于1，但对于细胞系来说，这一相关性更接近于零，这表明癌细胞系中前体miRNAs的加工减少。通过Northern blotting，我们发现许多miRNA(如miR-31、miR-105和miR-128a)被加工成前体，但原位杂交分析表明这些miRNA前体保留在细胞核中。我们提供了各种细胞类型中前体和成熟miRNA水平的数据库。我们的数据表明，大量的miRNAs被转录，但不被加工成成熟的miRNA。
Very little is known regarding regulation of microRNA (miRNA) biogenesis in normal tissues, tumors, and cell lines. Here, we profiled the expression of 225 precursor and mature miRNAs using real-time PCR and compared the expression levels to determine the processing patterns. RNA from 22 different human tissues, 37 human cancer cell lines, and 16 pancreas and liver tissues/tumors was profiled. The relationship between precursor and mature miRNA expression fell into the following four categories: (1) a direct correlation exists between the precursor and mature miRNA expression in all cells/tissues studied; (2) direct correlation of the precursor and mature miRNA exists, yet the expression is restricted to specific cell lines or tissues; (3) there is detectable expression of mature miRNA in certain cells and tissues while the precursor is expressed in all or most cells/tissues; or (4) both precursor and mature miRNA are not expressed. Pearson correlation between the precursor and mature miRNA expression was closer to one for the tissues but was closer to zero for the cell lines, suggesting that processing of precursor miRNAs is reduced in cancer cell lines. By using Northern blotting, we show that many of these miRNAs (e. g., miR-31, miR-105 and miR-128a) are processed to the precursor, but in situ hybridization analysis demonstrates that these miRNA precursors are retained in the nucleus. We provide a database of the levels of precursor and mature miRNA in a variety of cell types. Our data demonstrate that a large number of miRNAs are transcribed but are not processed to the mature miRNA.