miR-520d over-expression reverses chemotherapy resistance of TNBC via inhibiting autophagy protein Beclin1
10.3872/j.issn.1007-385x.2019.10.002
- VernacularTitle:过表达miR-520d通过抑制自噬蛋白Beclin1逆转三阴性乳腺癌细胞化 疗耐药性
- Author:
LIU Huan
1
;
LI Hongchang
2
;
CHEN Yafeng
1
;
XU Ke
3
;
LI Jie
1
;
FENG Dianxu
1
Author Information
1. Department of General Surgery, Putuo HospitalAffiliated to Shanghai University of Traditional Chinese Medicine,
2. Department of General Surgery, Minhang District Central Hospital
3. Central Laboratory, Putuo Hospital Affiliated to Shanghai University of Traditional Chinese Medicine,
- Publication Type:Journal Article
- Keywords:
miR-520d;
triple-negative breast cancer (TNBC);
Beclin1;
autophagy;
docetaxel (Doc);
chemotherapy resistance
- From:
Chinese Journal of Cancer Biotherapy
2019;26(10):1062-1067
- CountryChina
- Language:Chinese
-
Abstract:
Objective: To investigate the role and molecular mechanism of miR-520d in reversing the chemoresistance of triple negative breast cancer (TNBC) by regulating autophagy. Methods: Docetaxel (Doc) resistant cell lines MDA-MB-231/Doc and MDA-MB468/Doc were constructed by using human TNBC cell lines MDA-MB-231 and MDA-MB-468 as parental cells, and the cells were divided into blank group (parental cells), control group (drug-resistant group), and miR-520d over-expression group. The expression levels of miR-520d in cells of the blank and drug-resistant groups were detected by qPCR. The Doc-sensitivity of resistant cells over-expressing miR-520d was detected by MTT assay.After MDC staining, the generation of autophagosome in cells was observed under fluorescence microscopy; the number of miR-520d over-expressed resistant cells with positive LC3 expression was observed under confocal microscopy. The luciferase reporter gene assay was used to verify the targeting relationship between miR-520d and Beclin1. The effect of miR-520d mimics on the expression of autophagy-associated protein Beclin1, and LC3Ⅰ, LC3Ⅱ in cells was detected by WB assay. Results: The results of qPCR showed that the expression of miR-520d in the drug-resistant TNBC cells was significantly lower than that of normal cells (P<0.01). In drug-resistant cells over-expressing miR-520d, the Doc-sensitivity was significantly improved, while the autophagy activity was significantly reduced (all P<0.01).At the same time, luciferase experiments demonstrated that Beclin1 was a possible target molecule of miR-520d (P<0.05). WB results showed that the combination of docetaxel and miR-520d mimics reduced the LC3-II/I ratio and the expression of autophagy protein Beclin1 in drug-resistant TNBC cells (all P<0.05). Conclusion: The regulation of miR-520d levels may alter the expression of autophagy protein Beclin1, thereby reversing Doc chemotherapy resistance in TNBC cells.
- Full text:20191002.pdf
