Extracellular vesicle loaded with miR-494-3p can suppress ovarian cancer cell

Ovarian cancer (OC) accounts for the highest mortality rate among all gynecological malignancies. We intend to develop engineered exosomes to deliver the microRNA to inhibit the growth and progression of OC. Extracellular vesicles (EV) secreted by OC cells were isolated and loaded with miR-494-3p by electroporation to prepare the engineered miR-494-3p EV. The morphology and size of miR-494-3p EV were identified using the Transmission Electron Microscope and Nanoparticle Tracing Analysis. Western blot (WB) was conducted to detect the exosomal markers including TSG101 and CD63. The loading efficiency was assessed by qRT-PCR. Exosomes labeled with PKH26 were used to study the specific uptake by OC cells. OVCAR3 and SKOV3 cells were treated with EV, miR-NC EV, and miR-494-3p EV, respectively. EdU assay was conducted to evaluate proliferation. The level of miR-494-3p in OC tissues and cell lines was detected by qRT-PCR. Flow cytometry was used to detect apoptosis. Scratching assay was applied to evaluate migration. Transwell assay was used to evaluate migration and invasion. The levels of apoptosis-related, migration-related, and invasion-related proteins were assessed by WB. The results of qRT-PCR showed that miR-494-3p was significantly lower expressed in OC tissues than in normal tissues. The same is true in OC cell lines. The results showed that miR-494-3p EV could be successfully absorbed by OVCAR3 and SKOV3 cells. The expression of miR-494-3p in miR-494-3p EV or miR-494-3p EV-treated OC cells was significantly increased. The results of the EdU experiment, scratch experiment, and Transwell experiment showed that miR-494-3p EV significantly inhibited the proliferation, migration, and invasion of OC cells. Flow cytometry results showed that miR-494-3p EV significantly increased OC cell apoptosis. These results were further verified by the WB experiment. In summary, our study suggests that OC cell-derived miR-494-3p EV may play a role in the development of OC cells by inhibiting the proliferation, migration, and invasion of OC cells and promoting apoptosis. These findings may provide new therapeutic strategies for the clinical treatment of OC.