Cisplatin-resistant MDA-MB-231 Cell-derived Exosomes Increase the Resistance of Recipient Cells in an Exosomal miR-423-5p-dependent Manner.

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.

• Authors: Bing Wang, Yuzhu Zhang, Meina Ye, Jingjing Wu, Lina Ma, Hongfeng Chen
• Journal: Current drug metabolism (Curr Drug Metab) Vol. 20 Issue 10 Pg. 804-814 ( 2019) ISSN: 1875-5453 [Electronic] Netherlands
• PMID: 31424364 (Publication Type: Journal Article)
• Copyright: Copyright© Bentham Science Publishers; For any queries, please email at [email protected].

Chemical References

• Antineoplastic Agents
• MIRN423 microRNA, human
• MicroRNAs
• Cisplatin

Topics

• Antineoplastic Agents (pharmacology)
• Apoptosis (drug effects)
• Breast Neoplasms (genetics)
• Cell Cycle (drug effects)
• Cell Line, Tumor
• Cell Movement (drug effects)
• Cisplatin (pharmacology)
• Coculture Techniques
• Drug Resistance, Neoplasm (genetics)
• Exosomes (genetics)
• Female
• Humans
• MicroRNAs