Abstract: Background and purpose: Invasion and metastasis lead to poor prognosis in gastric cancer. In this study, we investigated the potential function of miR-26a in gastric cancer. Methods: Real-time fluorescent quantitative polymerase chain reaction (RTFQ-PCR) was used to detect the expression of miR-26a in gastric cancer cells. In vitro CCK-8 assay, cloning formation assay and Matrigel-Transwell assay were used to evaluate the proliferation, migration and invasion of gastric cancer cells. A luciferase reporter assay was also conducted to confirm that matrix metalloproteinase-16 (MMP16) is a direct target of miR-26a. Results: miR-26a was down-regulated in gastric cancer tissues compared with that in non-cancerous tissues. Functional studies showed that miR-26a inhibited cell proliferation, colony formation, cell motility and invasion. However, miR-26a had no effect on cell proliferation. We also characterized MMP16 as a direct target of miR-26a. We showed that knocking down MMP16 in gastric cancer cells significantly decreased MMP16 expression and inhibited cell invasion, whereas ectopic MMP16 expression significantly abrogated the suppressed cell invasion induced by miR-26a. Conclusion: miR-26a suppresses gastric cancer cell invasion by targeting MMP16. miR-26a could represent a potential therapeutic target for gastric cancer.

Key words: miR-26a, Gastric cancer, Matrix metalloproteinase-16, Invasion