Sayeed Aejaz, Dalvano Brielle E, Kaplan David E, Viswanathan Usha, Kulp John, Janneh Alhaji H, Hwang Lu-Yu, Ertel Adam, Doria Cataldo, Block Timothy
Baruch S. Blumberg Institute, Doylestown, PA, USA.
University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
Oncotarget. 2020 Jun 9;11(23):2216-2232. doi: 10.18632/oncotarget.27617.
The human circulation contains cell-free DNA and non-coding microRNA (miRNA). Less is known about the presence of messenger RNA (mRNA). This report profiles the human circulating mRNA transcriptome in people with liver cirrhosis (LC) and hepatocellular carcinoma (HCC) to determine whether mRNA analytes can be used as biomarkers of liver disease. Using RNAseq and RT-qPCR, we investigate circulating mRNA in plasma from HCC and LC patients and demonstrate detection of transcripts representing more than 19,000 different protein coding genes. Remarkably, the circulating mRNA expression levels were similar from person to person over the 21 individuals whose samples were analyzed by RNAseq. Liver derived circulating transcripts such as albumin (), apolipoprotein () A1, A2 & H, serpin A1 & E1, ferritin light chain () and fibrinogen like 1 () were significantly upregulated in HCC patient samples. Higher levels of some of these liver-specific transcripts in the plasma of HCC patients were confirmed by RT-qPCR in another cohort of 20 individuals. Several less abundant circulating transcripts associated with cancer were detected in most HCC samples, but not in healthy subjects. Liver specificity of circulating transcripts was confirmed by investigating their expression in HCC tumor and liver cancer cell lines. Liver specific mRNA sequences in the plasma were predominantly present outside circulating extracellular vesicles. Conclusions: The circulating "mRNA" transcriptome is remarkably consistent in diversity and expression from person to person. Detection of transcripts corresponding to disease selective polypeptides suggests the possibility that circulating mRNA can work as a biomarker analyte for cancer detection.
人体循环系统中含有游离DNA和非编码微小RNA（miRNA）。关于信使RNA（mRNA）的存在情况，人们了解较少。本报告分析了肝硬化（LC）和肝细胞癌（HCC）患者的人体循环mRNA转录组，以确定mRNA分析物是否可用作肝病的生物标志物。我们使用RNA测序（RNAseq）和逆转录定量聚合酶链反应（RT-qPCR），对HCC和LC患者血浆中的循环mRNA进行了研究，结果表明能够检测到代表超过19,000种不同蛋白质编码基因的转录本。值得注意的是，在通过RNAseq分析样本的21名个体中，循环mRNA的表达水平在个体之间相似。在HCC患者样本中，肝脏来源的循环转录本，如白蛋白（）、载脂蛋白（）A1、A2和H、丝氨酸蛋白酶抑制剂A1和E1、铁蛋白轻链（）和纤维蛋白原样蛋白1（）显著上调。在另一组20名个体中，通过RT-qPCR证实了HCC患者血浆中某些肝脏特异性转录本的水平较高。在大多数HCC样本中检测到了几种与癌症相关的丰度较低的循环转录本，但在健康受试者中未检测到。通过研究循环转录本在HCC肿瘤和肝癌细胞系中的表达情况，证实了其肝脏特异性。血浆中的肝脏特异性mRNA序列主要存在于循环细胞外囊泡之外。结论：循环“mRNA”转录组在个体之间的多样性和表达方面具有显著的一致性。对与疾病选择性多肽相对应的转录本的检测表明，循环mRNA有可能作为癌症检测的生物标志物分析物。
