Therapeutic potential of miRNAs in placental extracellular vesicles in ovarian and endometrial cancer.

There is a cross-link between the placenta and cancer development, as the placenta is grown as a highly invasive tumour-like organ. However, placental development is strictly controlled. Although the underlying mechanism of this control is largely unknown, it is now well-recognised that extracellular vesicles (EVs) released from the placenta play an important role in controlling placenta proliferation and invasion, as placental EVs have shown their effect on regulating maternal adaptation. Better understanding the tumour-like mechanism of the placenta could help to develop a therapeutic potential in cancers. In this study, by RNA sequencing of placental EVs, 20 highly expressed microRNAs (miRNAs) in placental EVs were selected and analysed for their functions on ovarian and endometrial cancer. There were up to seven enriched miRNAs, including miRNA-199a-3p, miRNA-143-3p, and miRNA-519a-5p in placental EVs showing effects on the inhibition of ovarian and endometrial cancer cell proliferation and migration, and promotion of cancer cell death, reported in the literature. Most of these miRNAs have been reported to be downregulated in ovarian and endometrial cancer. Transfection of ovarian and endometrial cancer cells with mimics of miRNA-199a-3p, miRNA-143-3p, and miRNA-519a-5p significantly reduced the cell viability. Our findings could provide strategies for using these naturally occurring miRNAs to develop a novel method to treat ovarian and endometrial cancer in the future.