中文摘要：

目的运用半定量逆转录一聚合酶链反应（RT-PCR）法分析miRl8和miR224在原发性肝细胞癌（HCC）和癌旁组织中的差异表达。方法提取肝癌细胞系SMMC7721的小分子RNA（≤200bp），通过对小分子RNA加poly-A尾和RT反应获得cDNA，建立一种扩增microRNA（miRNA）的RT-PCR方法，并采用该方法对10对HCC和癌旁组织中miRl8和miR224两种miRNAs的表达进行半定量分析。结果与癌旁组织相比，10例HCC组织中，miRl8有7例表达上调，3例表达下调；miR224有5例表达上调．5例表达下调。在miR224上调的5例HCC中miRl8表达均上调。结论HCC存在miRl8和miR224表达水平的改变；半定量RT-PCR方法为miRNA在肿瘤方面的研究提供了一个相对简便的方法。

英文摘要：

Objective To analyze the differential expressions of miR18 and miR224 in hepatocellular carcinoma （HCC） and adjacent normal tissues by semi-quantitative revese transcription polymerase chain reaction （RT-PCR）. Methods A RT-PCR was established and optimized using poly （A） tailed-small RNAs （ 〈 200 bp） which were extracted from hepatoma carcinoma cell line SMMC7721. Then the expressions of miR18 and miR224 in 10 pairs of HCC and adjacent normal tissues were semi-quantitatively analyzed by RT-PCR. Results Compared to adjacent normal tissues, the expression levels of miR18 were up-regulated in 7/10 and down-regulated in 3/10 HCC tissues, while the expression levels of miR224 were up-regulated in 5/10 and down-regulated in 5/10 HCC tissues respectively. Interestingly, the five HCC tissues with up-regulated miR224 also showed increased miR18 expression in parallel. Conclusion Aberrant expressions of miR18 and miR224 were found in HCC tissues. And the semi-quantitative RT-PCR provides a simple method for the study of miRNA in tumor.