Circulating serum exosomal miR-92a-3p as a novel biomarker for early diagnosis of gastric cancer

Gastric cancer (GC) is one of the common malignant tumors with high mortality. The abundance of miRNAs in serum exosomes has proved to have a high application value as a new noninvasive diagnostic method. The purpose of this study was to investigate whether serum exosomal miR-92a-3p could be used as a new biomarker for early diagnosis of GC and evaluate its clinical application value by detecting the expression of serum exosomal miR-92a-3p in 131 patients with primary GC and 122 healthy controls by qRT-PCR. The results showed that the expression level of serum exosomal miR-92a-3p in GC patients was significantly lower than that in normal controls (p < 0.0001). In addition, the level was closely correlated with lymph node metastasis and tumor node metastasis stage of GC patients. The area under the curve for serum exosomal miR-92a-3p was 0.829, significantly higher than for other indicators. Furthermore, combined detection of serum exosomal miR-92a-3p, CEA and CA19-9 was more sensitive than any of the three alone or any pair. These results showed that serum exosomal miR-92a-3p could be used as a novel new tumor biomarker to improve diagnostic efficiency in GC. Lay abstract Gastric cancer (GC) is one of the common malignant tumors with high mortality. There is an urgent need to explore minimally invasive and cost-effective biomarkers for early detection of GC. Accumulating evidence has demonstrated that exosomes play important roles in several biological events, like cell-to-cell communication, cellular metabolism, tumor metastasis, angiogenesis and immune response. The abundance of miRNAs in serum exosomes has proved valuable as a new noninvasive diagnostic method. The purpose of this study was to investigate whether serum exosomal miR-92a-3p could be used for early diagnosis of GC and to evaluate its clinical application value. The results showed that serum exosomal miR-92a-3p could be used as a novel new tumor biomarker to improve diagnostic efficiency in GC.