miR-329-containing exosomes derived from breast tumor cells suppress VEGF and KDM1A expression in endothelial cells

Abstract

The exosomal transfer of miRNAs from tumor cells is considered to modulate VEGF expression and angiogenesis in endothelial cells. The aim of our investigation was to focus exclusively on the ability of specific exosomal miR329 to regulate angiogenesis within breast tumor. All experiments were done on MCF-7 and HUVEC cell lines. Exosomes were derived from MCF-7 cells both untreated and treated with tamoxifen that is an effecrive suppressor of hormone receptor-positive breast cancer. The level of miR32 and its targeted genes VEGF and lysine (K)-specific demethylase 1A (KDM1A) expression was estimated with q-RT-PCR. The PKH26 red fluorescent labeling kit was used to label the isolated exosomes and monitor their uptake. It was shown that the relative amount of miR-329 in exosomes was twice as large as in breast cancer cells. Fluorescence microscopy imaging presented that exosomes from MCF-7 cells were able to penetrate into endothelial cells and concentrate in the cytoplasm. It was observed that exosomes derived from untreated breast cancer cells induced KDM1A and VEGF gene expressions whereas exosomes from tamoxifen-treated cancer cells induced time-dependent decrease of KDM1A and VEGF expression in endothelial cells. It is assumed that the transfer of miR-329 containing exosomes from tamoxifen treated breast cancer cells to the endothelial cells could repress angiogenic molecular signaling pathway and be used as a supplementary strategy in breast cancer treatment.

Keywords

• angiogenesis
• breast cancer
• exosome
• kdm1a
• mir-329
• tamoxifen
• vegf