Circulating exosomal miR-17-92 cluster serves as a novel noninvasive diagnostic marker for patients with gastric cancer.

Background: Gastric cancer (GC) is among the most common malignant tumors and remains a leading cause of cancer-related mortality worldwide. Furthermore, exosomal miRNAs are regarded as promising noninvasive biomarkers for diagnosing malignant tumors.

Aim: To investigate the expression of exosomal miR-17-92 clusters and develop a potential biomarker for GC diagnosis.

Methods: Exosomes were isolated from serum samples obtained from 72 GC patients and 20 healthy controls. The isolated exosomes were validated using transmission electron microscopy, nanoparticle tracking analysis, and western blotting. Exosomal RNA was then extracted, and the expression profile of the miR-17-92 cluster was analyzed using qRT-PCR. Statistical methods were employed to evaluate the relationship between the serum exosomal miR-17-92 cluster expression and the clinicopathological parameters of GC patients as well as to assess the diagnostic utility of these miRNAs.

Results: The expression of four members of the exosomal miR-17-92 cluster-miR-17, miR-18, miR-19a, and miR-92-was significantly upregulated in the serum samples of patients with GC compared with those of healthy controls. The miR-17-92 cluster panel demonstrated substantially higher clinical diagnostic value for GC than any individual component or pair. Additionally, the expression of traditional tumor biomarkers-carcinoembryonic antigen and carbohydrate antigen 19-9-was significantly elevated in the serum of patients with GC compared with that of healthy controls. Each biomarker, whether alone or in combination, effectively differentiated the patients from healthy controls. Furthermore, a combined panel of the two traditional tumor biomarkers and the four miR-17-92 cluster members exhibited the highest diagnostic accuracy for GC. Elevated miR-17-92 expression was also strongly associated with tumor size, tumor depth, lymph node metastasis, distant metastasis, and tumor-node-metastasis stage.

Conclusion: Our findings revealed that the circulating exosomal miR-17-92 cluster may be used as a potential noninvasive biomarker to improve diagnostic efficiency for GC.