Over the past decade, studies on microRNA (miRNA) and cancer quickly became known. miRNAs are small non-coding RNAs that play a vital role in regulation of gene expression. In the present study, the expression of miR-27b, miR-29a, and miR-155, their prognostic roles, and their potential targets in chronic lymphocytic leukemia (CLL) and breast cancer (BC) by qRT-PCR were investigated. In two case-control studies, qRT-PCR was used to analyze the peripheral blood serum of 15 CLL patients and tissue samples of 15 BC patients for the expression of miR-27b, miR-29a, and miR-155. miRNA expression levels were calculated using the qRT-PCR method. The results revealed a significant increase in the expression of all miRNAs in patients with BC and CLL compared with respective healthy groups (p < 0.001). In BC patients, there was a significant difference between the expression of miR-155 and miR-29a (p < 0.05), miR-155 and miR-27b (p < 0.01), and miR-27b and miR-29a (p < 0.001). In CLL patients, a significant difference between expression of both miR-27b and miR-29a compared with expression of miR-155 (p < 0.001) was found. Furthermore, a significant association between miR-155 and prevascular invasion was found. Significantly, elevated circulating miRNAs were shown to be BC specific and could differentiate BC tissues from the controls. It was demonstrated that miRNAs used in this study and their expression profiles can be developed as biomarkers for early diagnosis and prognosis of CLL and BC. Further studies utilizing a larger test group of patients would provide identification of miRNAs as key players in intercellular interactions.

在过去的十年中，有关microRNA（miRNA）和癌症的研究迅速为人们所熟知。miRNA是小的非编码RNA，在调节基因表达中起着至关重要的作用。在本研究中，通过qRT-PCR研究了miR-27b，miR-29a和miR-155的表达，其预后作用以及在慢性淋巴细胞性白血病（CLL）和乳腺癌（BC）中的潜在靶标。在两个病例对照研究中，使用qRT-PCR分析15位CLL患者的外周血血清和15位BC患者的组织样本中miR-27b，miR-29a和miR-155的表达。使用qRT-PCR方法计算miRNA表达水平。结果表明，与相应的健康组相比，BC和CLL患者的所有miRNA的表达均显着增加（p <0.001）。在卑诗省，miR-155和miR-29a（p <0.05），miR-155和miR-27b（p <0.01），miR-27b和miR-29a（p <0.001）的表达之间存在显着差异。在CLL患者中，发现miR-27b和miR-29a的表达与miR-155的表达之间存在显着差异（p <0.001）。此外，发现miR-155与血管前侵袭之间存在显着关联。显着地，升高的循环miRNA显示出是BC特异性的，并且可以将BC组织与对照区分开。结果表明，本研究中使用的miRNA及其表达谱可作为生物标记物用于CLL和BC的早期诊断和预后。利用更大的患者测试组的进一步研究将提供miRNAs作为细胞间相互作用的关键因素的鉴定。