Exosome transmit the ability of migration and invasion in heterogeneous ovarian cancer cells by regulating autophagy via targeting hsa-miR-328.

PURPOSE

This study investigates the role of exosomes in ovarian cancer heterogeneity, which contributes to metastasis. By examining the variability of exosomes from different ovarian cancer cells, which aims to elucidate the molecular mechanisms driving this heterogeneity.

EXPERIMENTAL DESIGN

Ovarian cancer cell lines were subjected to clonal culture and single-cell sorting. Monoclonal cell lines with different migration and invasion capabilities were identified using Transwell assays. The effect of exosomes on these abilities was assessed through Transwell, scratch tests, and in vivo experiments. High-throughput sequencing was used to compare miRNAs in exosomes with mRNAs in cells. Techniques like electron microscopy, immunofluorescence, adenoviral transduction, western blot, RNA-binding protein immunoprecipitation, and fluorescence in situ hybridization were employed to explore how exosomes affect cell migration and invasion.

RESULTS

Two subpopulations, SK-H/A-H (highly invasive) and SK-L/A-L (less invasive), were isolated. Exosomes from SK-H and A-H cells enhanced the migration and invasion of SK-L and A-L cells. Hsa-miR-328-3p was significantly upregulated in exosomes from SK-H and A-H cells, promoting invasive traits in SK-L and A-L cells, reducing Raf1 and mTOR expression, and increasing ULK1 and LC3B levels to promote autophagy. Overexpression of pri-miR-328-3p in SK-L and A-L cells resulted in similar effects.

CONCLUSIONS

Ovarian cancer cells with different invasive capabilities secrete distinct exosomes. Exosomes from highly invasive cells enhance these traits in less aggressive cells via hsa-miR-328-3p, which targets Raf1, disrupts the mTOR pathway, and promotes autophagy. This study highlights exosomes as carriers of hsa-miR-328-3p, mediating intercellular communication and autophagy to influence ovarian cancer cell heterogeneity.