College of Life Science, Zhejiang Sci-Tech University, Hangzhou, China.
Acta Biochim Biophys Sin (Shanghai). 2011 Jan;43(1):69-78. doi: 10.1093/abbs/gmq114.
MicroRNAs (miRNAs) are non-coding, single-stranded RNAs of approximately 22 nt and constitute a novel class of gene regulators that are found in both plants and animals. Several studies have demonstrated that serum miRNAs could serve as potential biomarkers for the detection of various cancers and other diseases. A few documents regarding the stability of liver cancer-related miRNAs in serum are available. A systemic analysis of the stability of miRNA in serum is quite necessary. The purpose of this study was to evaluate the stability of miRNAs from three different sources, cultured liver cancer Huh-7 cell line, clinical liver cancer, and serum under different experimental conditions, including different temperature, time duration, pH values, RNase A digestion, DNase I digestion, and various freeze-thaw cycles. The qRT-PCR analysis demonstrated that liver cancer-related miRNAs were detectable under each of test conditions, indicating that miRNAs were extremely stable and resistant to destruction and degradation under harsh environmental conditions. However, ribosomal RNA was fragile and easily degraded by demonstrating sharp decrease of relative expression under the non-physiological test conditions. We also established a robust procedure for serum RNA extraction, which is greatly important not only for the miRNA profiling studies but also for the disease prognosis based on abnormal miRNA expression.
微小 RNA（miRNA）是大约 22 个核苷酸的非编码、单链 RNA，构成了一类新的基因调控因子，存在于植物和动物中。多项研究表明，血清 miRNA 可作为检测各种癌症和其他疾病的潜在生物标志物。有一些关于肝癌相关 miRNA 在血清中稳定性的文献。对 miRNA 在血清中的稳定性进行系统分析是非常必要的。本研究旨在评估来自三种不同来源的 miRNA 的稳定性，即培养的肝癌 Huh-7 细胞系、临床肝癌和血清，在不同的实验条件下，包括不同的温度、时间、pH 值、RNase A 消化、DNase I 消化和不同的冻融循环。qRT-PCR 分析表明，肝癌相关 miRNA 在每种测试条件下都可检测到，表明 miRNA 在恶劣的环境条件下极其稳定，不易被破坏和降解。然而，核糖体 RNA 很脆弱，在非生理测试条件下相对表达量急剧下降，表明其容易降解。我们还建立了一种可靠的血清 RNA 提取方法，这不仅对 miRNA 图谱研究非常重要，而且对基于异常 miRNA 表达的疾病预后也非常重要。
