Correlation of mir-221-3p differential expression with clinical characteristics of gastric cancer patients

Gastric cancer (GC) is one of the most common digestive malignancies. Although miR-221-3p was defined as a novel biomarker in many types of cancer, the relationship between its expression differences and the clinicopathological characteristics and prognosis of GC patients was yet to be fully understood.

TCGA database was utilized to predict the potential biological function of miR-221-3p in GC. QRT-PCR and RNA FISH were performed to detect the expression levels of miR-221-3p in GC. The miR-221-3p expression levels in GC tissues and cells were significantly higher than those in paracancerous tissues (p < 0.001) and normal gastric mucosal cells (p < 0.05). Higher expression levels of miR-221-3p were associated with tumor diameter ≥ 4 cm (χ2 = 5.519, p = 0.019), cTNM stage (III + IV) (χ2 = 28.013, p = 0.000), lymph node metastasis (χ2 = 23.272, p = 0.000) and distant metastasis (χ2 = 7.930, p = 0.005). Kaplan-Meier survival analysis showed a better prognosis for GC patients with miR-221-3p low expression(HR = 4.520, 95% CI: 1.844–11.075).

miR-221-3p is highly expressed in GC tissues, which plays an important role in tumorigenesis, invasion and metastasis. miR-221-3p may become an important biomarker and potential molecular therapeutic target for patients with GC.