Extracellular RNA

[7][8] The United States National Institutes of Health (NIH) published in 2012 a set of Requests for Applications (RFAs) for investigating extracellular RNA biology.

[12][13][14][15] Although RNAs can be excreted from the cell without an enveloping container, ribonucleases present in extracellular environments would eventually degrade the molecule.

[7] exRNA can be shielded from RNases by RNA binding proteins (RBPs), on their own or within/associated with lipoprotein particles and extracellular vesicles.

Biochemical evidence supports the idea that exRNA uptake is a common process, suggesting new pathways for intercellular communication.

As a result, the presence, absence, and relative abundance of certain exRNAs can be correlated with changes in cellular signaling and may indicate specific disease states.

[26] These experimental and bioinformatics analyses favor the hypothesis that exRNAs play a role in numerous biological processes.

The major benefits of using RT-PCR are its quantitative accuracy in a dynamic range and increased sensitivity compared to methods such as RNase protection assays and dot blot hybridization.

The disadvantage to RT-PCR is the requirement of costly supplies, and the necessity of sound experimental design and an in-depth understanding of normalization techniques in order to obtain accurate results and conclusions.

An RNA sample can then be added to the chip, and RNAs with sequence complementarity to the cDNA probe will bind and generate a fluorescent signal that can be quantified.

Unlike microarrays, RNA sequencing is not constrained by factors such as oligonucleotide generation, and the number of probes that can be added to a chip.

[1][32] The potential of extracellular RNAs to serve as biomarkers is significant not only because of their role in intercellular signaling but also due to developments in next generation sequencing that enable high throughput profiling.