POLG inhibitor suppresses migration and invasion of triple-negative breast cancer cells via blocking mitochondrial biogenesis
10.19405/j.cnki.issn1000-1492.2024.10.005
- VernacularTitle:POLG抑制剂阻碍线粒体生物合成抑制三阴性乳腺癌细胞迁移和侵袭
- Author:
Xing LIU
1
;
Shuangqin FAN
;
Xiaomin YAN
;
Shijie ZHAO
;
Rong WANG
;
Xiangchun SHEN
;
Xue ZHOU
;
Yue ZHANG
;
Yan CHEN
Author Information
1. 贵州医科大学天然药物资源优效利用重点实验室,安顺 561113
- Keywords:
triple-negative breast cancer;
migration;
invasion;
POLG inhibitor;
mitochondrial biogenesis;
ATP synthesis
- From:
Acta Universitatis Medicinalis Anhui
2024;59(10):1720-1728
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the effects of zalcitabine(ddC),a mitochondrial DNA polymerase γ(POLG)inhibitor,on the migration,invasion,and to preliminarily explore mitochondrial biogenesis of human tri-ple-negative breast cancer MDA-MB-231 cells.Methods The effect of ddC on cell viability was detected using the MTT assay.The migration and invasion abilities of the cells were evaluated using the cell scratch and Transwell in-vasion assays.Cell apoptosis was determined using flow cytometry and a V-FITC/PI cell apoptosis detection kit.The protein expression of POLG,NADH dehydrogenase subunit Ⅰ(NADH1),NADH dehydrogenase subunit Ⅱ(NADH2),ATP synthase subunit 6(ATPase6),cytochrome c oxidase subunit Ⅰ(COX-1)and cytochrome c ox-idase subunit Ⅲ(COX-3)were determined using Western blot.The POLG mRNA level and mtDNA copy number were determined using qPCR.The mitochondrial content and ATP levels were determined using MitoTracker Green fluorescent probe staining and an ATP determination kit.MDA-MB-231 cells were transfected with pcDNA3.1-EG-FP-POLG plasmids to overexpress POLG.The inhibitory effects of ddC on cell migration and invasion were detected in POLG-overexpressed MDA-MB-231 cells.Results POLG expression was higher in MDA-MB-231 cells than in normal mammary epithelial cells(MCF-10A)(P＜0.01).ddC inhibited cell viability in a dose-dependent man-ner.ddC inhibited the migration(P＜0.01)and invasion(P＜0.01)of MDA-MB-231 cells;however,it dis-played no significant inhibitory effects on cell viability in normal mammary epithelial cells(MCF-10A)at the same concentration.ddC downregulated the protein(P＜0.01)and mRNA(P＜0.01)levels of POLG,reduced mtD-NA copy number(P＜0.01)and downregulated mtDNA-coded NADH1,NADH2,ATPase6,COX-1 and COX-3 protein expression(P＜0.01)in MDA-MB-231 cells.Furthermore ddC inhibited mitochondrial content(P＜0.01)and ATP(P＜0.01)levels in MDA-MB-231 cells.POLG overexpression increased the migration(P＜0.05)and invasion(P＜0.05)abilities of MDA-MB-231 cells,while ddC did not significantly inhibit the migra-tion and invasion abilities of MDA-MB-231 cells overexpressing POLG.Conclusion ddC downregulates POLG ex-pression in MDA-MB-231 cells and inhibits mitochondrial biogenesis and ATP levels,thereby inhibiting the migra-tion and invasion of MDA-MB-231 cells.
