MicroRNA-134-3p is a novel potential inhibitor of human ovarian cancer stem cells by targeting RAB27A

•DLK1-DIO3 microRNA cluster has different expression between OCSCs and OCCs (CD44 −/CD133 −).•Low miR-134-3p in OCSCs correlates with RAB27a overexpression.•We confirmed RAB27a mRNA a novel target of miR-134-3p.•Overexpression for miR-134-3p inhibits OCSCs in vitro.•MiR-134-3p transfection decreases OCSCs xenograft tumor growth.

The cluster of microRNAs (miRNAs) in the DLK1-DIO3 genomic imprinted region contains several miRNAs that have a significant regulatory role in tumor proliferation and invasion. One of these miRNAs is miR-134-3p, and its expression changes significantly in human ovarian cancer stem cells (OCSCs) and in CD44 −/CD133 − ovarian cancer. The results of a luciferase assay showed that miR-134-3p silenced RAB27A by binding to the 3′-UTR of RAB27A mRNA. Overexpression of miR-134-3p in human OCSCs can not only inhibit the expression of RAB27A but also can effectively downregulate the expression of some tumor proliferation and invasion genes. Overexpression of miR-134-3p can not only inhibit the in vitro proliferation and cell cycle progression of human OCSCs but also can decrease the tumorigenicity in nude mice.