Circulating long RNAs in serum extracellular vesicles: Their Characterization and Potential Application as Biomarkers for the Diagnosis of Colorectal Cancer

Long non-coding RNA and mRNAs are long RNAs (> 200 nucleotides) compared to microRNAs. In blood, long RNAs may be protected by serum extracellular vesicles, such as apoptotic bodies (ABs), microvesicles (MVs), and exosomes (EXOs). They are potential biomarkers for identifying cancer.

Sera from 76 pre-operative CRC patients, 76 age- and sex-matched healthy subjects and 20 colorectal adenoma (CA) patients without CRC were collected. Researchers at Fudan University investigated the distribution of 79 long RNAs chosen from the The Cancer Genome Atlas (TCGA) in the three types of vesicles using quantitative PCR (qPCR). The quantity of long RNAs has varying distribution among three subtypes of extracellular vesicles in serum. Most mRNAs and lncRNAs genes had higher quantity in EXOs than that in ABs and MVs, while MVs contain lowest quantity. In the training and test sets, the areas under the curves (AUC) were 0.936 and 0.877 respectively. The AUC of total serum RNA was lower (0.857) than that of exosomal RNA in the same samples (0.936).

The work flow chart of selecting colorectal cancer biomarkers from exosome long RNA. CG: colorectal cancer; CA: colorectal adenoma.