Effects of Michigan Cancer Foundation-7/A New Adriamycin Cell-Derived Exosomes on MCF-7 Cell Apoptosis and Drug Sensitivity Through Ubiquitin Carboxyl-Terminal Hydrolase L1

Abstract

Exosomes secreted by adriamycin-resistant human breast cancer cell line MCF-7/ADR can promote the resistance of normal breast cancer cells. However, the exosomes? contents remain unclear. This article investigated the effect of UCHL1 in MCF-7/ADR-derived exosomes on MCF-7 cell apoptosis and drug sensitivity. In this experiment, control group (NC group), Exosome group, Exosome+ siRNA-UCHL1 group were set followed by analysis of exosomes morphology by electron microscope, UCHL1 and Tubulin level by Western Blot, UCHL1 level by immunofluorescence, UCHL1 mRNA level by qRT-PCR, cell apoptosis by flow cytometry, and drug sensitivity by MTT assay. The size and morphology of exosomes were normal with high expression of UCHL1 and CD63. Compared to NC group, UCHL1 level in Exosome group was significantly increased, while siRNAUCHL1 could reduce UCHL1 level; in addition, Exosome group showed significantly decreased cell apoptosis (P < 0.01) which was elevated in Exosome+siRNA-UCHL1 group (P < 0.05); finally, drug sensitivity in Exosome group was significantly increased (P < 0.01) and decreased in the Exosome+siRNA-UCHL1 group (P < 0.05). MCF-7/ADR-derived UCHL1 in exosome can increase UCHL1 level in MCF-7 cells, reduce cell apoptosis and drug sensitivity of cells.