Reversal of adriamycin resistance by digoxin in human breast cancer cell line MCF-7/adriamycin and its mechanism.
- Author:
Bai-He LI
1
;
Lei YUAN
1
;
Ran-Ran SHI
1
;
Jian-Guo WANG
2
Author Information
1. Laboratory of Molecular Biology, Luohe Medical College, Luohe 462002, China.
2. Laboratory of Molecular Biology, Luohe Medical College, Luohe 462002, China. wr0395@sina.com.
- Publication Type:Journal Article
- MeSH:
ATP Binding Cassette Transporter, Sub-Family B;
metabolism;
Apoptosis;
Breast Neoplasms;
metabolism;
pathology;
Digoxin;
pharmacology;
Doxorubicin;
pharmacology;
Drug Resistance, Neoplasm;
Humans;
Hypoxia-Inducible Factor 1, alpha Subunit;
metabolism;
MCF-7 Cells;
drug effects;
RNA, Messenger;
Transfection
- From:
Acta Physiologica Sinica
2015;67(6):611-617
- CountryChina
- Language:Chinese
-
Abstract:
The aim of this study was to investigate the effects of digoxin on the chemoresistance of human breast cancer cell line MCF-7/adriamycin (ADR) and its underlying mechanism. MCF-7 and MCF-7/ADR cells were designated as control and ADR groups, respectively. MCF-7/ADR cells in ADR + digoxin group received 48 h of digoxin (10 nmol/L) treatment; MCF-7/ADR cells transfected with pLKO.1-shHIF-1α and pLKO.1-shcontrol plasmids were named shHIF-1α and shcontrol groups, respectively. CCK-8 assay was employed to detect the cytotoxic effect of ADR on MCF-7/ADR cells, and IC50 value and resistance index were calculated according to CCK-8. RT-PCR was used to measure the mRNA levels of hypoxia inducible factor-1α (HIF-1α) and multidrug resistance-1 (MDR1). Western blot was used to analyze the protein levels of HIF-1α and MDR1. Flow cytometry was used to determine the apoptosis. The result showed that the resistance index of MCF-7/ADR cells was 115.6, and it was reduced to 47.2 under the action of digoxin (P < 0.05). In comparison with control group, ADR groups showed increased protein and mRNA levels of HIF-1α and MDR1 (P < 0.05). Digoxin reduced the protein levels of HIF-1α and MDR1, as well as the mRNA level of MDR1, but did not affect the mRNA level of HIF-1α. After HIF-1α gene was silenced, the protein levels of HIF-1α and MDR1 were down-regulated (P < 0.05), and the pro-apoptotic effect of ADR on MCF-7/ADR cells was enhanced. Although it was also observed that digoxin promoted cell apoptosis in both shcontrol and shHIF-1α groups, the difference between the two groups was not significant. In conclusion, the results suggest that digoxin may partially reverse the ADR resistance in human breast cancer cell line MCF-7/ADR by means of down-regulating the expression levels of HIF-1α and MDR1 and promoting apoptosis via HIF-1α-independent pathway.
