The Extracellular RNA Communication Consortium: Establishing Foundational Knowledge and Technologies for Extracellular RNA Research

Abstract

The Extracellular RNA Communication Consortium (ERCC) was launched to accelerate progress in the new field of extracellular RNA (exRNA) biology and to establish whether exRNAs and their carriers, including extracellular vesicles (EVs), can mediate intercellular communication and be utilized for clinical applications. Phase 1 of the ERCC focused on exRNA/EV biogenesis and function, discovery of exRNA biomarkers, development of exRNA/EV-based therapeutics, and construction of a robust set of reference exRNA profiles for a variety of biofluids. Here, we present progress by ERCC investigators in these areas, and we discuss collaborative projects directed at development of robust methods for EV/exRNA isolation and analysis and tools for sharing and computational analysis of exRNA profiling data. The Origin of the ERCC1 ProgramThe discovery that extracellular vesicles (EVs) can transport RNAs between cells (Skog et al., 2008;Valadi et al., 2007) suggested that RNAs carried by EVs may play a previously unrecognized role in intercellular communication and launched the field of extracellular RNA (exRNA) biology. It was quickly recognized that exRNAs might also have utility as biomarkers of disease and as therapeutic agents. There were, however, many gaps in knowledge and technical challenges to overcome. The mechanisms of EV biogenesis and uptake, exRNA cargo selection, and exRNA function were largely unknown. Moreover, efficient and reproducible methods for isolation and analysis of exRNAs were not available, further complicated by early findings that suggesting that exRNAs can associate with multiple subtypes

Extracellular Vesicles in Non-Small-Cell Lung Cancer: Functional Role and Involvement in Resistance to Targeted Treatment and Immunotherapy

“…Combination of western blot, nanoparticle tracking, and flow cytometry is usually used to verify EV purity, and can be completed by using proteomics, lipidomics, RNA/DNA analysis to study EV composition [110]. The scientific community has agreed on the urgent need to standardize the procedure of EV isolation from patients' liquid biopsies, validate EV-associated biomarkers, and put experimental guidelines into practice [7,113,114]. Moreover, highly stringent and novel isolation methodologies now provide a reappraisal of what classifies the variety of circulating nanoparticles, distinguishing vesicular and non-vesicular components, rather than exosomes or larger microvesicles [20].…”

“…Based on the evidence that blood levels of EV miRNAs significantly increases during cancer conditions, EV-associated miRNAs are now considered to be a most promising biomarker for the blood-based early detection of cancer [117]. In fact, when included into EVs, cell released miRNAs are rather stable and easy-to-detect [118], and, although most of the analysis on circulating miRNA is still exploratory, blood-based RNA profiling of cancer patients has provided a valuable source of information to understand tumor's evolution and adaptation to therapeutic pressure in many clinical studies [114].…”

“…Improvement of efficient and cost-effective methodologies for separation of exosomes and microvesicles population from the background of non-EV particles, based on their surface proteome composition, can foster the ultrasensitive detection of cancer-specific mutations on mRNA that could implement classical ctDNA blood analysis [36,124]. At the same time, construction of reference collections of vesicular RNAs that include predictive biomarkers for immunotherapy and targeted therapy will serve as a shared fundamental resource for future application of exRNAs [114,125].…”

Comparison of miRNA profiling methods using synthetic miRNA pools and standardized exRNA samples reveals substantial performance differences

“…miRNAs can be released from cells and have been detected in over 15 biological fluids (Godoy et al, 2018, Sohel, 2016) and have been proposed as possible biomarkers for tissue pathologies. Accordingly, there is strong interest in using miRNAs as biomarkers for prediction and diagnosis of disease or for monitoring response to therapy (Das et al, 2019). Several miRNA measurement methods exist and have been used extensively, including quantitative PCR (qPCR), microarrays, and small RNA-sequencing.…”

“…The NIH-supported Extracellular RNA Communication Consortium (ERCC) was launched to establish foundational knowledge and technologies for extracellular RNA research (Das et al, 2019). Here we report the results of an ERCC-supported miRNA analysis platform comparison that examined reproducibility, bias, specificity, and relative quantification using both defined pools of synthetic miRNAs and pooled human plasma samples.…”