Title:Cisplatin-resistant MDA-MB-231 Cell-derived Exosomes Increase the Resistance of Recipient Cells in an Exosomal miR-423-5p-dependent Manner
VOLUME: 20 ISSUE: 10
Author(s):Bing Wang, Yuzhu Zhang, Meina Ye, Jingjing Wu, Lina Ma and Hongfeng Chen*
Affiliation:Department of Breast, Longhua Hospital Affiliated with Shanghai University of TCM, Shanghai 200032, Department of Breast, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou 510006, Department of Breast, Longhua Hospital Affiliated with Shanghai University of TCM, Shanghai 200032, Department of Breast, Longhua Hospital Affiliated with Shanghai University of TCM, Shanghai 200032, Department of Breast, Longhua Hospital Affiliated with Shanghai University of TCM, Shanghai 200032, Department of Breast, Longhua Hospital Affiliated with Shanghai University of TCM, Shanghai 200032
Keywords:DDP resistance, exosomes, miR-423-5p, cisplatin, breast cancer, in vitro.
Abstract:
Background: Chemoresistance blunts the therapeutic effect of cisplatin (DDP) on Triple-Negative Breast
Cancer (TNBC). Researchers have not determined to date whether exosomes confer DDP resistance to other breast
cancer cells or whether exosomal transfer of miRNAs derived from DDP-resistant TNBC cells confer DDP resistance.
Objective: The aim of this study was to investigate the role of exosomes in chemoresistance in breast cancer.
Methods: MDA-MB-231 cells resistant to DDP (231/DDP) were established. Exosomes were isolated from 231/DDP
cells (DDP/EXO) and characterized by measuring the levels of protein markers, nanoparticle tracking analysis and
transmission electron microscopy. MDA-MB-231, MCF-7 and SKBR-3 cell lines were treated with the isolated
DDP/EXOs and cell proliferation and cytotoxicity to DDP were evaluated using MTT assays and apoptosis analyses.
Western blotting was used to examine P-glycoprotein (P-gp) expression. Additionally, a microarray was used to
analyse microRNA (miRNA) expression profiles in MDA-MB-231 and 231/DDP exosomes. The effects on miRNAs
were determined using RT-PCR. Exosomal miR-423-5p was extracted, and differential expression was verified. The
MTT cell viability assay, flow cytometry, and Transwell and immunofluorescence assays were performed to determine
if differential expression of miR-423-5p sensitized cells to DDP in vitro.
Results: Under a transmission electron microscope, the isolated exosomes exhibited a round or oval shape with a
diameter ranging between 40 and 100 nm. DDP/EXOs labelled with PKH67 were taken up by MDA-MB-231 cells.
After an incubation with DDP/EXOs, the cell lines exhibited a higher IC50 value for cisplatin, P-gp expression, migration
and invasion capabilities and a lower apoptosis rate. Furthermore, 60 miRNAs from exosomes derived from
231/DDP cells were significantly up-regulated compared to exosomes from MDA-MB-231 cells. Notably, compared
to the corresponding sensitive exosomes, miR-370-3p, miR-423-5p and miR-373 were the most differentially expressed
miRNAs in DDP-resistant exosomes. We chose miR-423-5p, and up-regulation and down-regulation of
exosomal miR-423-5p expression significantly affected DDP resistance.
Conclusions: Exosomes from DDP-resistant TNBC cells (231/DDP) altered the sensitivity of other breast cancer
cells to DDP in an exosomal miR-423-5p dependent manner. Our research helps to elucidate the mechanism of DDP
resistance in breast cancer.
