Comprehensive Assessment of Plasma-Derived circ_0004771 as a Potential Biomarker in Tracking the Progression of Gastric Cancer

Abstract

Background: Due to the lack of specific and sensitive detection indicators, most patients with gastric cancer (GC) are already in the advanced stage at the time of diagnosis, resulting in a higher mortality. Therefore, it is urgent to search for effective diagnostic biomarkers with high specificity that can be applied in clinic. Methods: We screened out circ_0004771 through circRNA sequencing performed on three pairs of GC tissues and corresponding paracancerous tissues. Both exonuclease digestion assay, agarose gel electrophoresis (AGE) and sanger sequencing verified the potential of circ_0004771 being a biomarker. Additionally, we established quantitative real-time fluorescent Polymerase Chain Reaction (qRT-PCR) to detect the expression level of circ_0004771 and evaluated the methodology. What’s more, we collected plasma samples from GC patients, precancerous patients and gastritis patients, and we constructed the receiver operating characteristic curve (ROC) to appraise its diagnostic efficacy. Meanwhile, we collected the clinicopathological data of the patients to analyze the relationship between the expression level of circ_0004771 and the pathological parameters of the patients. Results: The expression level of circ_0004771 is up-regulated both in GC tissues and cells compared to normal controls. Circ_0004771 can be served as a promising biomarker because of its stable cyclic structure and longer half-life. The expression level of plasma circ_0004771 can distinguish between GC patients and precancerous patients, GC patients and gastritis patients. The diagnostic efficiency of circ_0004771 is higher than that of CEA and CA199. Higher diagnostic efficiency can be achieved in combination diagnosis. The expression level of plasma circ_0004771 in GC patients decreased after surgery, which can track the recovery condition of patients. Besides, the downstream regulatory forecast indicates that circ_0004771 may act as miRNA sponge to regulate the progression of GC.Conclusion: Plasma circ_0004771 can be served as a less invasive tumor biomarker with high diagnostic values.