Plasma circRNAs as Biomarkers in Cancer

Abstract

The incidence and mortality of cancer are increasing each year. At present, the sensitivity and specificity of the blood biomarkers that were used in clinical practice are low, which make the detection rate of cancer decrease. With advances in bioinformatics and technology, some non-coding RNA as biomarkers can be easily detected through some traditional and new technologies. Circular RNAs (circRNAs) are non-coding RNAs, that is, they do not encode proteins, and have important regulatory functions. CircRNAs can remain stable in bodily fluids, such as in saliva, blood, urine, and especially plasma. The difference in the expression of plasma circRNAs between cancer patients and normal people may suggest that plasma circRNAs may play an important role in the occurrence and development of cancer. In this review, we summarized the clinical effect of plasma circRNAs in several high-incidence cancers. CircRNAs may be effective biomarkers for tumour diagnosis, treatment selection and prognosis evaluation.

Keywords:

• circular RNA
• plasma
• cancer
• biomarkers

Acknowledgments

Qian Zhou and LinLing Ju contributed equally to this study. All authors have reviewed and agreed on the final version to be published. This research was funded by Nantong Science and Technology Bureau (MS12020023, MS22020014, MSZ20099, and JC2020011), Jiangsu Health and Health Committee (Z2020011), and Health Bureau of Nantong City (MA2020014, MA2020015).

Abbreviations

circRNAs, circular RNAs; CEA, carcinoembryonic antigen; CA 19-9, cancer antigen 19-9; AFP, alpha-fetoprotein; ciRNAs, circular intronic RNAs; ElciRNAs, exon-intronic circRNAs; EcircRNAs, exonic circRNAs; RBP, RNA-binding protein; ceRNAs, competitive endogenous RNAs; MREs, miRNA response elements; EGFR, epidermal growth factor receptor; IRS2, insulin receptor substrate 2; IGF1, insulin-like growth factor 1; HCG, human chorionic gonadotropin; RT-ddPCR, reverse transcriptase-digital droplet polymerase chain reaction; ROC, receiver operating characteristic; AUC, the area under the curve; HBV, Hepatitis B virus infection; HCC, hepatocellular carcinoma; AFP-L3, lens culinaris-agglutinin-reactive fraction of AFP; PIVKA-II, protein induced by vitamin K absence or antagonist-II; CEA, carcinoembryonic antigen; CA19-9, cancer antigen 19-9; OS, overall survival; DSS, disease‐specific survival.

Disclosure

The authors report no conflicts of interest in this work.