Estrogen receptor knock down therapy using microRNA for breast cancer patients

已经确定了几个直接靶向ERα的microRNAs(MiRNAs)。本研究通过定量逆转录聚合酶链式反应分析了乳腺癌组织中针对ERα的miR-18a、miR-18b、miR-22、miR-193B、miR-206、miR-221/222和miR-302C的表达水平。分析这些miRNAs的表达水平与临床病理因素的关系。在ERα阴性的乳腺癌中，miR-18a的表达明显高于ERα阳性的肿瘤，而在ERα阳性的乳腺癌中，miR-18a的表达水平与ERα蛋白水平无关。令人惊讶的是，在ERα阴性的肿瘤中，miR-193B和miR-221的表达水平显著低于ERα阳性的肿瘤，并且这些miRNAs的表达水平随着ERα蛋白表达的增加而逐渐升高。我们的结果表明，miR-206可能是一种仅针对乳腺癌ERα的内分泌治疗的新候选药物。

Several microRNAs(miRNAs) that directly target ERα have been identified. In this study, expression levels of miRNAs that directly target ERα, including miR-18a, miR-18b, miR-22, miR-193b, miR-206, miR-221/222 and miR-302c, were analyzed in human breast cancer samples by quantitative reverse transcription-PCR analysis. Correlations between the expression levels of these miRNAs and clinicopathological factors were analyzed. miR-18a expression was much higher in ERα-negative than in ERα-positive tumors, with the expression levels of miR-18a not differing in ERα-positive breast cancer as a function of ERαprotein level. Surprisingly, the expression levels of miR-193b and miR-221 were significantly lower in ERα-negative than in ERα-positive tumors, and the levels of these miRNAs gradually increased as ERα protein expression increased. Our results suggest that miR-206 could be a novel candidate for endocrine therapy that targets only ERα in breast cancer.