Finally, a distinct gene expression between miR-221-3p and ARF4 in EOC group and normal group was identified, and the negative correlation between their expression levels in EOC specimens was further confirmed.
Given that tumorsphere-derived SKOV-3 had a higher ratio of CD24<sup>+/high</sup> cells, we suggest that miR-26a, miR-125b-5p, miR-17-5p and miR-221 downregulation could be related to poor EOC prognosis.
These findings indicate that serum miR-221 may have a role as a novel diagnostic and prognostic marker, and may have potential as a therapeutic target in EOC.