The Landscape of MicroRNA, Piwi-Interacting RNA, and Circular RNA in Human Saliva

By J. Bahn, Qing Zhang, Feng Li, Tak-Ming Chan, Xianzhi Lin, Yong Kim, David T. W. Wong, Xinshu Xiao. Clinical Chemistry, 2014

609 citations recorded by the source corpus.

BACKGROUND Extracellular RNAs (exRNAs) in human body fluids are emerging as effective biomarkers for detection of diseases. Saliva, as the most accessible and noninvasive body fluid, has been shown to harbor exRNA biomarkers for several human diseases. However, the entire spectrum of exRNA from saliva has not been fully characterized. METHODS Using high-throughput RNA sequencing (RNA-Seq), we conducted an in-depth bioinformatic analysis of noncoding RNAs (ncRNAs) in human cell-free saliva (CFS) from healthy individuals, with a focus on microRNAs (miRNAs), piwi-interacting RNAs (piRNAs), and circular RNAs (circRNAs). RESULTS Our data demonstrated robust reproducibility of miRNA and piRNA profiles across individuals. Furthermore, individual variability of these salivary RNA species was highly similar to those in other body fluids or cellular samples, despite the direct exposure of saliva to environmental impacts. By comparative analysis of >90 RNA-Seq data sets of different origins, we observed that piRNAs were surprisingly abundant in CFS compared with other body fluid or intracellular samples, with expression levels in CFS comparable to those found in embryonic stem cells and skin cells. Conversely, miRNA expression profiles in CFS were highly similar to those in serum and cerebrospinal fluid. Using a customized bioinformatics method, we identified >400 circRNAs in CFS. These data represent the first global characterization and experimental validation of circRNAs in any type of extracellular body fluid. CONCLUSIONS Our study provides a comprehensive landscape of ncRNA species in human saliva that will facilitate further biomarker discoveries and lay a foundation for future studies related to ncRNAs in human saliva.

Subfields: Cancer Research, Molecular Biology, Physiology

View Paper: https://www.semanticscholar.org/paper/6cc59d64fb902ad032f9e0fb58a185437c4f72a4

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Cancer Research

1. Nikolaus Rajewsky
2. Panagiotis Papavasileiou
3. Julia Salzman
4. Ling-Ling Chen

In Molecular Biology

1. Oliver Peters
2. Nikolaus Rajewsky
3. Panagiotis Papavasileiou
4. Sebastian Memczak
5. Julia Salzman
6. Ling-Ling Chen
7. Steven P. Barrett

Citations in the corpus

• Identification and Characterization of Circular RNAs As a New Class of Putative Biomarkers in Human Blood (2015, background): “Recent publications show that circRNAs can be detected in plasma and saliva samples [32,33].”
• CircNet: a database of circular RNAs derived from transcriptome sequencing data (2015, background): “The fact that cell free circRNAs were found stable in saliva (29) as well as exosomes (30) makes circRNA a promising diagnosis biomarker.”
• CircRNA: a novel type of biomarker for cancer (2017, background): “With the exception of the peculiar expression in tissues, circRNAs are also found in saliva [25] and exosomes [28], and it is believed that circRNAs are also regarded as a biological governor.”