Differential microRNA expression profiles in primary and recurrent epithelial ovarian cancer

Background/Aim: Although it has been shown that microRNAs influence messenger RNA post-transcriptional control and can attribute to human tumorigenesis, little is known regarading the differences in microRNA expression between primary and recurrent epithelial ovarian cancer (EOC). The purpose of the present study was to assess the differential expression of microRNA between primary and recurrent EOC. Materials and Methods: Between September 2013 and May 2014, the expression of microRNAs in tumor tissues from 5 primary and 5 recurrent EOC cases were analyzed. The tumor histotype was serous cystadenocarcinoma in all patients. Total RNA was extracted from tumor samples and microRNA expression levels were measured by performing microarray analysis. Expression levels were compared between the two groups and analyzed statistically. Results: Several microRNAs were differentially expressed in recurrent EOC compared to primary EOC, including 18 underexpressed microRNAs and 33 over-expressed microRNAs among 6,658 human microRNAs. Four specific microRNAs were the most significantly over-expressed in recurrent EOC: miR-551b, miR-19b, miR-196b and miR-3198. Moreover, 4 specific microRNAs were the most significantly down-expressed in recurrent EOC: miR-8084, miR-3201, miR-3613 and miR-7515. Conclusion: Based on our data, dysregulation of microRNA expression was associated with the recurrence of EOC. Moreover, significantly over- and down-regulated microRNAs can be useful biomarkers for the prediction of recurrence in EOC.