Exosomal Non Coding RNA in LIQUID Biopsies as a Promising Biomarker for Colorectal Cancer

Abstract

Colorectal cancer (CRC) is one of the most common cancers worldwide, with a high mortality rate, especially in those that are diagnosed in late stages of the disease. The current screening blood-based markers, such as carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9), have low sensitivity and specificity. Meanwhile, other modalities are either expensive or invasive. Therefore, recent research has shifted towards a minimally invasive test, namely, liquid biopsy. Exosomes are favorable molecules sought in blood samples, since they are abundant, stable in circulation, and harbor genetic information and other biomolecules that could serve as biomarkers or even therapeutic targets. Furthermore, exosomal noncoding RNAs, such as miRNAs, lncRNAs, and circRNAs, have demonstrated the diagnostic potential to detect CRC at an early stage with a higher sensitivity and specificity than CEA and CA19-9 alone. Moreover, they have prognostic potential that is TNM stage specific and could serve as predictive biomarkers for the most common chemotherapeutic drug and combination regimen in CRC, which are 5-FU and FOLFOX, respectively. Therefore, in this review, we focus on the role of these exosomal noncoding RNAs as diagnostic, prognostic, and predictive biomarkers. In addition, we discuss the advantages and challenges of exosomes as a liquid biopsy target.

LincRNA-p21 Levels Relates to Survival and Post-Operative Radiotherapy Benefit in Rectal Cancer Patients

“…LncRNA expression has been shown to discriminate between tumor and normal tissue better than protein-coding genes [ 13 ]. In this setting, lncRNAs have gained interest as novel biomarkers for CRC determined in both tumor tissue and liquid biopsy samples [ 14 , 15 ].…”

Clinical Perspectives on Liquid Biopsy in Metastatic Colorectal Cancer

“…Studies have indicated that, besides ctDNA and CTC, circulating non-coding RNAs are emerging as important biomarkers for the clinical management of CRC patients ( Rapado-González et al, 2019 ; Baassiri et al, 2020 ). In body fluids, circulating non-coding RNA mainly exist in either the cell-free state or the exosomal form.…”

Circular RNAs in Human Cancer

“…Exosomes are relatively more stable than serum at room temperature. These aspects may suggest exosomal circRNAs good diagnostic and prognostic biomarkers ( 158 ).…”