miRNA-543 promotes cell migration and invasion by targeting SPOP in gastric cancer

BACKGROUND/PURPOSE: Given the emerging role of microRNA (miRNA) in cancer progression, we investigated the role and mechanism of miRNA-543 (miR-543) in gastric cancer (GC). MATERIALS AND METHODS: Real-time quantitative polymerase chain reaction was conducted to quantify the expression of miR-543. Luciferase reporter assay was used to confirm the association between speckle-type POZ protein (SPOP) and 3′-UTR. Moreover, the role of miR-543 and SPOP in GC was detected using transwell assays. In addition, we investigated the function of miR-543 in the epithelial–mesenchymal transition (EMT) progression. RESULTS: miR-543 was upregulated in GC. We identified SPOP as a direct target of miR-543, revealing its expression to be inversely correlated with miR-543 expression in GC tissues. Moreover, restoration of SPOP could inhibit miR-543-induced GC cell migration and invasion, whereas downregulation of miR-543 inhibited cell migration and invasion, which was partly abrogated by SPOP knockdown. Furthermore, our data also showed that miR-543 induced EMT of GC cells. CONCLUSION: Our results demonstrated that miR-543 functions as a crucial oncogenic miRNA in GC. It exerts strong tumor-promoting effects through targeting SPOP in GC cell migration and invasion.