Knockdown of miR-24 suppresses the proliferation, migration and invasion of gastric cancer cells and predicts a poor prognosis in gastric cancer

Objective: Gastric cancer (GC) is one of the leading causes of cancer death worldwide. MicroRNAs have recently emerged as key regulators of GC. In this study, we tried to investigate the effects of knockdown of miR24 on the proliferation, migration and invasion of gastric cancer cells. Methods: A total of 28 GC tissue samples and matched non-tumor tissue samples were obtained from surgery patients at First Affiliated Hospital of Nanjing Medical University between 2013-2014. Human GC cell lines MGC803, AGS, BGC823 and SGC7901 were cultured. MiRNA mimics and their appropriate negative control were used to knock down the target gene. QRT-PCR, Western blot were used to test the expression of the gene and MTT assay, cell migration and invasion assay were adopted to evaluate the cells' proliferation, migration and invasion. Results: Results showed that miR-24 was up-regulated in GC tissues and cell lines. Knockdown of miR-24 remarkably suppressed cell proliferation of GC cell lines SGC7901. Moreover, knocking down on miR-24 also significantly suppressed migration and invasion of GC cells SGC7901. What's more, the results of viewing on patients showed the patients in the miR-24-positive group had a poorer prognosis than did the patients in miR-24-negative group. Conclusion: Taken together, miR-24 could suppress GC cells growth and motility. MiR-24 acts as a predictor of a poor prognosis in patients with GC.