Serum miR-30c serves as potential biomarkers for the diagnosis and prognosis of gastric cancer.

Gastric cancer (GC)，the fourth leading cause of cancer-related deaths globally and thus early detection, is considered critical for diagnosis and treatment of this disease. It is well known that measurement of microRNA (miRNA) may serve as diagnostic and prognostic biomarker for GC. The aim of this study was to determine whether miR-30c was present in patients with gastric cancer and to correlate relative expression with patient survival. A total of 162 GC patients and 150 healthy controls were recruited. miR-30c levels were quantified in serum using quantitative real-time PCR(QRT-PCR). The sensitivity and specificity of circulating miR-30c was compared to carbohydrate antigen (CA) CA72-4, CA19-9, and carcinoembryonic antigen (CEA), 3 known markers associated with GC. QRT-PCR demonstrated downregulation of gene expression of miR-30c in GC patients. Downregulation of miR-30c gene expression was significantly correlated with stage of cancer, lymphatic metastasis, and distal metastasis. The sensitivity to detect GC of miR-30c, CA72-4, CA19-9, and CEA in serum of GC was 80%, 43%, 21%, and 42%, respectively, while specificity was 89%, 57%, 30%, and 78% respectively. Kaplan-Meier survival analysis showed that the presence of low gene expression of miR-30c was effective in predicting poor prognosis in GC patients. Our data suggest that circulating serum miR-30c concentrations may serve as a reliable biomarker for GC occurrence. (212words).