Introduction:Triple-Negative Breast Cancer (TNBC) is the most common
type of breast cancer (BC). In order to develop effective treatments for TNBC, it is vital
to identify potential therapeutic targets. Angiogenesis stimulates tumor growth and metastasis
in TNBC, and miR-155 plays a crucial role in this process. The exosome is a
nano-sized vesicle that carries many cargoes, including miRNAs. The present study investigated
the effect of exosomal delivery of miR-155 antagomir on tumor migration, invasion,
and angiogenesis in TNBC.Materials and methods:From MDA-MB-231 cells, exosomes were extracted, characterized,
and loaded with miR-155 antagomir using electroporation. The expression of
miR-155 and its target genes, including PTEN and DUSP14, was analyzed using RTqPCR.
The wound-healing and transwell assays were used to measure cell migration and
invasion. Furthermore, angiogenesis was evaluated by tube formation and chorioallantoic
membrane (CAM) assays.Results:The results indicated that exosomal delivery of miR-155 antagomir to HUVEC
cells significantly suppressed miR-155 expression while upregulating PTEN and DUSP14.
The tube formation properties of HUVEC cells were also significantly reduced following
treatment with exosomes containing miR-155 antagomirs, and these results were
confirmed using CAM assay. The migration and invasion of MDA-MB-231 cells were
significantly reduced after treatment with miR-155 antagomir-loaded exosomes.Conclusion:It was found that miR-155 antagomir delivery using exosomes can inhibit
migration, invasion, and angiogenesis viaPTEN and DUSP14 in TNBC.