Clinical significance of miR-21 expression in breast cancer: SYBR-Green I-based real-time RT-PCR study of invasive ductal carcinoma
Clinical significance of miR-21 expression in breast cancer: SYBR-Green I-based real-time RT-PCR study of invasive ductal carcinoma
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DOI：
10.3892/or_00000270
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发表时间：
2009-03-01
期刊：
影响因子：
4.2
通讯作者：
Hu, Xiao-Qu
中科院分区：
文献类型：
--
作者：
Huang, Guan-Li;Zhang, Xiao-Hua;Hu, Xiao-Qu
越来越多的证据表明microRNAs（miRNAs）在肿瘤发生中起重要作用。MicroRNA-21（miR-21）在包括乳腺癌在内的许多恶性肿瘤中上调。其与乳腺癌临床病理特征及靶基因之一的PTEN（phosphatase and tensin homolog deleted on chromosome 10）表达的关系尚未见系统报道。为了进一步确定miR-21在乳腺癌中的潜在作用，我们采用基于SYBR-Green I的茎环实时RT-PCR方法评估了miR-21在人乳腺浸润性导管癌中的表达水平，并将结果与临床病理特征和PTEN蛋白表达相关联。采用基于SYBR-Green I的茎环实时RT-PCR方法检测40例乳腺浸润性导管癌组织和癌旁组织中miR-21的表达。免疫组化（IHC）检测肿瘤组织中PTEN的表达。miR-21的表达水平与PTEN及乳腺癌常用的临床病理特征相关。基于SYBR-Green I的茎环实时荧光定量RT-PCR检测miR-21具有较高的灵敏度和特异性。肿瘤组织中miR-21的表达水平显著高于配对的非肿瘤组织（P=0.000）。miR-21与PTEN表达呈负相关（P=0.013）。miR-21表达上调与淋巴结阳性（P=0.01）、较高的增殖指数（Ki 67>10%）（P=0.03）和晚期乳腺癌TNM临床分期（P=0.021）相关。这些发现表明，PTEN可能是miR-21在乳腺癌中的靶点之一，并且miR-21的高表达指示更侵袭性的表型。
Growing evidence suggests microRNAs (miRNAs) have an important role in tumorigenesis. MicroRNA-21 (miR-21) is up-regulated in many malignant tumors, including breast cancer. Its association with clinicopathologic features and expression of PTEN (phosphatase and tensin homolog deleted on chromosome 10), one of its target genes, in breast cancer has not been reported systematically. To further determine the potential involvement of miR-21 in breast cancer, we have evaluated the expression level of miR-21 by stem-loop real-time RT-PCR based on SYBR-Green I in human invasive ductal carcinoma of the breast, and we have correlated the results with clinicopathologic features and PTEN protein expression. Matched non-tumor and tumor tissues of 40 human invasive ductal carcinoma of the breast were analyzed for miR-21 expression by stem-loop realtime RT-PCR based on SYBR-Green I. Immunohistochemistry (IHC) was used to estimate PTEN expression in tumor tissue. The expression levels of miR-21 were correlated with PTEN and commonly used clinicopathologic features of breast cancer. The stem-loop real-time RT-PCR based on SYBR-Green I was sensitive and specific enough to detect miR-21. Expression levels of miR-21 were significantly higher in tumor tissues than the levels in matched nontumor tissues (P=0.000). Expression of miR-21 was negatively correlated with expression of PTEN (P=0.013). Up-regulated miR-21 expression was associated with lymph node positivity (P=0.01), higher proliferation index (Ki67>10%) (P=0.03) and advanced breast cancer TNM clinical stage (P=0.021). These findings suggest that PTEN is possibly one of the targets of miR-21 in breast cancer and high expression of miR-21 indicates a more aggressive phenotype.