MicroRNA-130b functions as a tumor suppressor by regulating RUNX3 in epithelial ovarian cancer

Aim: To evaluate the clinical significance of microRNA (miR)-130b-Runt domain transcription factor (RUNX3) axis and its effects on oncogenic phenotypes of human epithelial ovarian cancer (EOC). Methods: QRT-PCR was performed to detect the expression of miR-130b and RUNX3 mRNA in 100 EOC and 20 normal ovarian tissues. The associations between miR-130b and/or RUNX3 expression and various clinicopathological features of EOC patients were statistically analyzed. Then, the effects of miR-130b-RUNX3 axis on migration and invasion of EOC cells were assessed in vitro. Results: miR-130b expression was downregulated, while RUNX3 mRNA was upregulated, in EOC tissues compared to normal ovarian tissues (both P = 0.001). Importantly, the expression level of miR-130b in EOC tissues was negatively correlated with that of RUNX3 mRNA significantly. Additionally, miR-130b-low and/or RUNX3-high expression were all closely correlated with advanced International Federation of Gynecology and Obstetrics (FIGO) stage (all P < 0.05). Moreover, overexpression of miR-130b reduced the expression of RUNX3 and inhibited cancer cell migration and invasion of EOC cells, whereas knockdown of miR-130b increased the expression of RUNX3 and promoted cancer cell migration and invasion of EOC cells. After that, the impaired motility of the miR-130b overexpression cells was recovered partly by the expression of RUNX3. Furthermore, the knockdown of RUNX3 also gave rise to a decrease in cell migration and invasion. Conclusion: Our data reveal that the dysregulation of miR-130b-RUNX3 axis may play important roles in EOC development and progression, and the loss of miR-130b may contribute to the malignant biological behavior of EOC cells via regulating the expression of RUNX3, implying their potentials as promising markers for predicting EOC progression and as candidate targets for gene therapy. (C) 2016 Elsevier B.V. All rights reserved.