Drug resistance can be reversed by beta-elemene. - GreenMedInfo Summary
β-Elemene Reverses Chemoresistance of Breast Cancer Cells by Reducing Resistance Transmission via Exosomes.
Cell Physiol Biochem. 2015 ;36(6):2274-86. Epub 2015 Jul 24. PMID: 26279432
BACKGROUND: Currently, exosomes that act as mediators of intercellular communication are being researched extensively. Our previous studies confirmed that these exosomes contain microRNAs (miRNAs) that could alter chemo-susceptibility, which is partly attributed to the successful intercellular transfer of multidrug resistance (MDR)-specific miRNAs. We also confirmed thatβ-elemene could influence MDR-related miRNA expression and regulate the expression of the target genes PTEN and Pgp, which may lead to the reversal of the chemoresistant breast cancer (BCA) cells. We are the first to report these findings, and we propose the following logical hypothesis: β-elemenecan mediate MDR-related miRNA expression in cells, thereby affecting the exosome contents, reducing chemoresistance transmission via exosomes, and reversing the drug resistance of breast cancer cells.
METHODS: MTT-cytotoxic, miRNA microarray, real-time quantitative PCR, Dual Luciferase Activity Assay, and Western blot analysis were performed to investigate the impact ofβ-elemene on the expression of chemoresistance specific miRNA and PTEN as well as Pgp in chemoresistant BCA exosomes.
RESULTS: Drug resistance can be reversed byβ-elemene related to exosomes. There were 104 differentially expressed miRNAs in the exosomes of two chemoresistant BCA cells: adriacin (Adr) - resistant MCF-7 cells (MCF-7/Adr) and docetaxel (Doc) - resistant MCF-7 cells (MCF-7/Doc) that underwent treatment. Of these, 31 miRNAs were correlated with the constant changes in the MDR. The expression of miR-34a and miR-452 can lead to changes in the characteristics of two chemoresistant BCA exosomes: MCF-7/Adr exosomes (A/exo) and MCF-7/Doc exosomes (D/exo). The PTEN expression affected by β-elemene was significantly increased, and the Pgp expression affected by β-elemene was significantly decreased in both cells and exosomes. β-elemene induced a significant increase in the apoptosis rate in both MCF-7/Doc and MCF-7/Adr cells.
CONCLUSIONS: Drug resistance can be reversed byβ-elemene, which can alter the expression of some MDR-related miRNAs, including PTEN and Pgp in MCF-7/Adr and MCF-7/Doc in cells. It can therefore affect the exosome contents and induce the reduction of resistance transmission via exosomes.