MiR-361-5p exerts tumor-suppressing functions in gastric carcinoma by targeting syndecan-binding protein.

Abstract

MiR-361-5p, a tumor-related microRNA, has been reported to be implicated in the tumorigenesis and progression of diverse types of human malignancies; however, its role in gastric carcinoma remains unclear. This study aimed to explore the biological role of miR-361-5p in gastric carcinoma and clarify the potential mechanisms involved. In the present study, miR-361-5p was found to be significantly downregulated in both gastric carcinoma tissues and cell lines. Functional studies demonstrated that enhanced expression of miR-361-5p suppressed gastric carcinoma cell proliferation in vitro, inhibited tumor growth in vivo, and induced gastric carcinoma cell apoptosis. Moreover, the tumor-suppressing effects of miR-361-5p in gastric carcinoma were abrogated by the miR-361-5p inhibitor treatment. Notably, syndecan-binding protein was downregulated by miR-361-5p via direct binding to its 3' untranslated region in gastric carcinoma cells. Furthermore, syndecan-binding protein expression was discovered to be markedly upregulated and inversely correlated with miR-361-5p expression in gastric carcinoma tissues. Mechanistic studies revealed that restoring the expression of syndecan-binding protein alleviated miR-361-5p-induced inhibitory effects on proliferation of gastric carcinoma cells. Taken together, these findings suggest that miR-361-5p functions as a tumor suppressor in gastric carcinoma by directly targeting syndecan-binding protein and that miR-361-5p might be a novel therapeutic target for gastric carcinoma.